FN Thomson Reuters Web of Science™ VR 1.0 PT J AU McGregor, DS Lindsay, JT Olsen, RW AF McGregor, DS Lindsay, JT Olsen, RW TI Thermal neutron detection with cadmium(1-x) zinc(x) telluride semiconductor detectors SO NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH SECTION A-ACCELERATORS SPECTROMETERS DETECTORS AND ASSOCIATED EQUIPMENT LA English DT Article AB Cadmium zinc telluride (CdZnTe) detectors have been used to detect thermal neutrons. The CdZnTe detectors were placed in a double diffracted thermal neutron beam and the prompt gamma ray emissions from thermal neutron interactions in the Cd have been detected. The devices clearly show the 558.6 and 651.3 keV prompt gamma ray emission peaks from 113Cd(n, gamma) Cd-114 reactions. The intrinsic detection sensitivity is dependent on the gamma ray absorption efficiency, which is measured to be approximately (3.7 +/- 1.9) % at 558.6 keV for a 3 mm x 10 mm CdZnTe device. C1 UNIV MICHIGAN,PHOENIX MEM LAB,ANN ARBOR,MI 48109. RP McGregor, DS (reprint author), SANDIA NATL LABS,MS 9671,LIVERMORE,CA 94550, USA. NR 12 TC 33 Z9 33 U1 2 U2 6 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0168-9002 J9 NUCL INSTRUM METH A JI Nucl. Instrum. Methods Phys. Res. Sect. A-Accel. Spectrom. Dect. Assoc. Equip. PD NOV 1 PY 1996 VL 381 IS 2-3 BP 498 EP 501 DI 10.1016/S0168-9002(96)00580-3 PG 4 WC Instruments & Instrumentation; Nuclear Science & Technology; Physics, Nuclear; Physics, Particles & Fields SC Instruments & Instrumentation; Nuclear Science & Technology; Physics GA VY450 UT WOS:A1996VY45000031 ER PT J AU Drozhdin, AI Huhtinen, M Mokhov, NV AF Drozhdin, AI Huhtinen, M Mokhov, NV TI Accelerator related background in the CMS detector at LHC SO NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH SECTION A-ACCELERATORS SPECTROMETERS DETECTORS AND ASSOCIATED EQUIPMENT LA English DT Article AB Complete calculations of the accelerator related background in the muon spectrometer of the CMS detector at the Large Hadron Collider are presented. The simulations have been performed with the STRUCT multi-turn tracking code and the MARS and FLUKA cascade codes taking into account latest information of the LHC lattice, vacuum conditions, beam cleaning system and the shielding and layout of the CMS experiment. Beam loss distributions in the interaction regions and their vicinities and their contribution to the background levels in the muon spectrometer of CMS are analyzed. The studies show that hadronic and electromagnetic components of machine background are efficiently suppressed by the proposed CMS shielding, High energy muons penetrate through the shielding, but in positions of significance they do not contribute more than a few percent compared to the background generated by the pp-collisions. It is anticipated that the relative contribution of accelerator background will be higher during the first years of operation, but will drop down with the LHC performance evolution. The obtained results concerning the machine background and the efficiency of the proposed shielding are rather generic and can be directly applied to the ATLAS detector. C1 CERN,CH-1211 GENEVA,SWITZERLAND. DESY,D-22603 HAMBURG,GERMANY. FERMILAB NATL ACCELERATOR LAB,BATAVIA,IL 60510. NR 29 TC 9 Z9 9 U1 0 U2 0 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0168-9002 J9 NUCL INSTRUM METH A JI Nucl. Instrum. Methods Phys. Res. Sect. A-Accel. Spectrom. Dect. Assoc. Equip. PD NOV 1 PY 1996 VL 381 IS 2-3 BP 531 EP 544 DI 10.1016/S0168-9002(96)00807-8 PG 14 WC Instruments & Instrumentation; Nuclear Science & Technology; Physics, Nuclear; Physics, Particles & Fields SC Instruments & Instrumentation; Nuclear Science & Technology; Physics GA VY450 UT WOS:A1996VY45000038 ER PT J AU Weare, CB Yarmoff, JA Sroubek, Z AF Weare, CB Yarmoff, JA Sroubek, Z TI The effects of charge promotion on the measured charge state of low-energy Li+ scattered from alkali/Al(100) SO NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH SECTION B-BEAM INTERACTIONS WITH MATERIALS AND ATOMS LA English DT Article ID ELECTRON-EMISSION; COVERED AL(100); COLLISIONS; SURFACES AB Charge promotion of an inner-shell electron during ion bombardment of a surface can strongly affect the neutralization of scattered particles, In this work, the neutral fractions for 2.0 keV Li-7(+) scattered from clean and alkali-covered Al(100) are measured with time-of-flight spectroscopy. During hard collisions, a fraction of the Li particles that scatter from Al atoms undergo a promotion of their 1s electrons above the Fermi level, with subsequent Li 1s hole creation. Differences are observed between the neutral fractions of the scattered promoted and non-promoted projectiles, and these neutral fractions depend on the alkali coverage. Secondary electron spectra collected during Li bombardment are used to identify the decay channels of the Li 1s hole. The results indicate that the Li 1s hole decays both near the surface via an Auger process and in vacuum via auto-ionization. Therefore, the lifetime of the 1s hole is on the order of the scattering time. C1 UNIV CALIF RIVERSIDE,DEPT PHYS,RIVERSIDE,CA 92521. UNIV CALIF BERKELEY,LAWRENCE BERKELEY NATL LAB,DIV MAT SCI,BERKELEY,CA 94720. ACAD SCI CZECH REPUBL,INST RADIO ENGN & ELECT,PRAGUE 18251 8,CZECH REPUBLIC. NR 16 TC 1 Z9 1 U1 1 U2 1 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0168-583X J9 NUCL INSTRUM METH B JI Nucl. Instrum. Methods Phys. Res. Sect. B-Beam Interact. Mater. Atoms PD NOV PY 1996 VL 119 IS 3 BP 352 EP 358 DI 10.1016/0168-583X(96)00363-1 PG 7 WC Instruments & Instrumentation; Nuclear Science & Technology; Physics, Atomic, Molecular & Chemical; Physics, Nuclear SC Instruments & Instrumentation; Nuclear Science & Technology; Physics GA VQ522 UT WOS:A1996VQ52200006 ER PT J AU Susskind, H Weber, DA Atkins, HL Franceschi, D Volkow, ND AF Susskind, H Weber, DA Atkins, HL Franceschi, D Volkow, ND TI Does detoxification reverse the acute lung injury of crack smokers? SO NUCLEAR MEDICINE COMMUNICATIONS LA English DT Article ID COCAINE CRACK; AEROSOL; INHALATION; CLEARANCE; SMOKING; USERS; ACID AB The effect on chronic crack users of a 3 month detoxification programme on lung clearance of inhaled Tc-99(m)-diethylenetriamine pentaacetate (Tc-99(m)-DTPA) aerosol, spirometry and gas exchange was determined in a controlled in-patient clinical treatment setting. Imaging studies were carried out in eight chronic crack users (four crack-only and four crack plus tobacco) before and after the successful completion of the detoxification programme to measure the clearance of inhaled Tc-99(m)-DTPA from the lungs, an index of lung epithelial permeability. Tc-99(m)-DTPA lung clearance, expressed in terms of the biological half-time, T-1/2, was determined from the slopes of the least-squares fit regression lines of the respective time-activity plots. The mean (+/- S.D.) global T-1/2 values of the crack-only (75+/-39 min) and crack plus tobacco users (22+/-10 min) were significantly shorter (P < 0.02 and P < 0.001, respectively) than from the lungs of the non-smoking controls (124 +/- 29 min). This was consistent with increased lung epithelial permeability secondary to crack-related lung injury. The mean global T-1/2 value of the crack plus tobacco users was significantly shorter (P < 0.05) than that of the crack-only users. After detoxification, the abnormally rapid lung clearance became normal in two of the four crack-only users studied, improved in a third and remained unchanged in the fourth, a subject whose T-1/2 value was already normal initially. However, lung clearance improved in only one of the four crack plus tobacco users studied. Faster Tc-99(m)- DTPA clearance was the only impairment found in seven of the eight crack users, the eighth having restrictive lung disease. Crack-related lung injury, reflected by abnormally rapid Tc-99(m)-DTPA lung clearance, may be at least partially reversible after a 3 month period of abstinence from crack. RP Susskind, H (reprint author), BROOKHAVEN NATL LAB,CLIN RES CTR,BOX 5000,UPTON,NY 11973, USA. FU NIDA NIH HHS [5 RO1-DA06891] NR 17 TC 0 Z9 0 U1 0 U2 0 PU CHAPMAN HALL LTD PI LONDON PA 2-6 BOUNDARY ROW, LONDON, ENGLAND SE1 8HN SN 0143-3636 J9 NUCL MED COMMUN JI Nucl. Med. Commun. PD NOV PY 1996 VL 17 IS 11 BP 963 EP 970 DI 10.1097/00006231-199611000-00007 PG 8 WC Radiology, Nuclear Medicine & Medical Imaging SC Radiology, Nuclear Medicine & Medical Imaging GA VX102 UT WOS:A1996VX10200007 PM 8971868 ER PT J AU Barger, V Berger, MS Gunion, JF Han, T AF Barger, V Berger, MS Gunion, JF Han, T TI Particle physics opportunities at mu(+)mu(-) colliders SO NUCLEAR PHYSICS B LA English DT Article; Proceedings Paper CT Symposium on Physics Potential and Development of mu(plus)mu(minus) Colliders CY DEC 13-15, 1995 CL SAN FRANCISCO, CA ID SUPERSYMMETRIC STANDARD MODEL; HIGGS-BOSON PRODUCTION; INFRARED FIXED-POINT; TOP-QUARK MASS; SUPERGRAVITY MODELS; E+E-ANNIHILATION; CP VIOLATION; THRESHOLD; DECAY; UNIFICATION AB We discuss the capabilities of future muon colliders to resolve important particle physics questions. A collider with c.m. energy root s = 100 to 500 GeV offers the unique opportunity to produce Higgs bosons in the s-channel and thereby measure the Higgs masses, total widths and several partial widths to high precision. At this same machine, and W+W- threshold studies would yield superior precision in the determination of m(t) and m(w). A multi-TeV mu(+)mu(-) collider would open up the realm of physics above the 1 TeV scale, allowing, for example, copious production of supersymmetric particles up to the highest anticipated masses or a detailed study of the strongly-interacting scenario of electroweak symmetry breaking. C1 INDIANA UNIV,DEPT PHYS,BLOOMINGTON,IN 47405. LAWRENCE LIVERMORE NATL LAB,DEPT PHYS,DAVIS,CA 95616. RP Barger, V (reprint author), UNIV WISCONSIN,DEPT PHYS,1150 UNIV AVE,MADISON,WI 53706, USA. OI Han, Tao/0000-0002-5543-0716 NR 57 TC 14 Z9 14 U1 0 U2 0 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0550-3213 J9 NUCL PHYS B JI Nucl. Phys. B PD NOV PY 1996 SU 51A BP 13 EP 31 DI 10.1016/0920-5632(96)00412-4 PG 19 WC Physics, Particles & Fields SC Physics GA VR872 UT WOS:A1996VR87200003 ER PT J AU Perlmutter, S Boyle, B Bunclark, P Carter, D Couch, W Deustua, S Dopita, M Ellis, R Filippenko, AV Gabi, S Glazebrook, K Goldhaber, G Goobar, A Groom, D Hook, I Irwin, M Kim, A Kim, M Lee, J Matheson, T McMahon, R Newberg, H Pain, R Pennypacker, C Small, I AF Perlmutter, S Boyle, B Bunclark, P Carter, D Couch, W Deustua, S Dopita, M Ellis, R Filippenko, AV Gabi, S Glazebrook, K Goldhaber, G Goobar, A Groom, D Hook, I Irwin, M Kim, A Kim, M Lee, J Matheson, T McMahon, R Newberg, H Pain, R Pennypacker, C Small, I TI High-redshift supernova discoveries on demand: First results from a new tool for cosmology and bounds on q(0) SO NUCLEAR PHYSICS B LA English DT Article; Proceedings Paper CT 2nd Symposium on Dark Matter in the Universe CY FEB 14-16, 1996 CL SANTA MONICA, CA SP UCLA ID IA SUPERNOVAE AB We have developed a new tool for measurement of the cosmological parameters: a systematic search-and-study technique for high-redshift supernovae. In the first years of this Supernova Cosmology Project, we have discovered over 27 supernovae. Using a ''batch'' search strategy, almost all were discovered before maximum light and were observed over the peak of their light curves. The spectra and light curves indicate that almost all were Type Ia supernovae at redshifts z = 0.35 - 0.65. These high-redshift supernovae can provide a distance indicator and ''standard clock'' to study the cosmological parameters q(0), Lambda, Omega(0) and H-0. This presentation and the following presentation of Goldhaber et al. (1996), will discuss observation strategies and rates, analysis and calibration issues, the sources of measurement uncertainty, and the cosmological implications, including bounds on po, of the first 7 high-redshift supernovae from our ongoing search. This is one of the most direct approaches to cosmological measurements, and could become a standard method in the field. C1 UNIV CALIF BERKELEY,CTR PARTICLE ASTROPHYS,BERKELEY,CA 94720. ROYAL GREENWICH OBSERV,CAMBRIDGE,ENGLAND. UNIV NEW S WALES,KENSINGTON,NSW 2033,AUSTRALIA. AUSTRALIAN NATL UNIV,MSSSO,CANBERRA,ACT 2601,AUSTRALIA. UNIV CAMBRIDGE,INST ASTRON,CAMBRIDGE CB2 1TN,ENGLAND. UNIV CALIF BERKELEY,BERKELEY,CA 94720. UNIV STOCKHOLM,STOCKHOLM,SWEDEN. FERMILAB NATL ACCELERATOR LAB,BATAVIA,IL 60510. RP Perlmutter, S (reprint author), UNIV CALIF BERKELEY,LAWRENCE BERKELEY LAB,BERKELEY,CA 94720, USA. RI Perlmutter, Saul/I-3505-2015; OI Perlmutter, Saul/0000-0002-4436-4661; Glazebrook, Karl/0000-0002-3254-9044 NR 22 TC 3 Z9 3 U1 0 U2 0 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0550-3213 J9 NUCL PHYS B JI Nucl. Phys. B PD NOV PY 1996 SU 51B BP 20 EP 29 DI 10.1016/S0920-5632(96)00478-1 PG 10 WC Physics, Particles & Fields SC Physics GA VY665 UT WOS:A1996VY66500004 ER PT J AU Soni, A AF Soni, A TI CP violation and flavor-changing-currents at mu(+)mu(-) colliders SO NUCLEAR PHYSICS B LA English DT Article; Proceedings Paper CT Symposium on Physics Potential and Development of mu(plus)mu(minus) Colliders CY DEC 13-15, 1995 CL SAN FRANCISCO, CA ID NEUTRAL CURRENTS; DECAYS AB Production and decay (CP) asymmetries at mu(+)mu(-) collider, in extensions of the Standard Model (SM) are reported. Production asymmetries appear to be very promising for a large range of parameters, decays are less effective. Importance of flavor-changing scalar currents involving the top are emphasized. At lepton colliders, the final state is uniquely suited for such searches. At a muon collider there is the novel possibility of tree level mu(+)mu(-) --> . This talk is based on works done in collaboration with David Atwood and Laura Reina [1-4]. RP Soni, A (reprint author), BROOKHAVEN NATL LAB,DEPT PHYS,UPTON,NY 11973, USA. NR 13 TC 3 Z9 3 U1 0 U2 0 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0550-3213 J9 NUCL PHYS B JI Nucl. Phys. B PD NOV PY 1996 SU 51A BP 32 EP 39 DI 10.1016/0920-5632(96)00413-6 PG 8 WC Physics, Particles & Fields SC Physics GA VR872 UT WOS:A1996VR87200004 ER PT J AU Palmer, R Sessler, A Skrinsky, A Tollestrup, A Baltz, A Caspi, S Chen, P Cheng, WH Cho, Y Cline, D Courant, E Fernow, R Gallardo, J Garren, A Gordon, H Green, M Gupta, R Hershcovitch, A Johnstone, C Kahn, S Kirk, H Kycia, T Lee, Y Lissauer, D Luccio, A McInturff, A Mills, F Mokhov, N Morgan, G Neuffer, D Ng, KY Noble, R Norem, J Norum, B Oide, K Parsa, Z Polychronakos, V Popovic, M Rehak, P Roser, T Rossmanith, R Scanlan, R Schachinger, L Silvestrov, G Stumer, I Summers, D Syphers, M Takahashi, H Toran, Y Trbojevic, D Turner, W VanGinneken, A Vsevoloshskaya, T Weggel, R Willen, E Willis, W Winn, D Wurtele, J Zhao, Y AF Palmer, R Sessler, A Skrinsky, A Tollestrup, A Baltz, A Caspi, S Chen, P Cheng, WH Cho, Y Cline, D Courant, E Fernow, R Gallardo, J Garren, A Gordon, H Green, M Gupta, R Hershcovitch, A Johnstone, C Kahn, S Kirk, H Kycia, T Lee, Y Lissauer, D Luccio, A McInturff, A Mills, F Mokhov, N Morgan, G Neuffer, D Ng, KY Noble, R Norem, J Norum, B Oide, K Parsa, Z Polychronakos, V Popovic, M Rehak, P Roser, T Rossmanith, R Scanlan, R Schachinger, L Silvestrov, G Stumer, I Summers, D Syphers, M Takahashi, H Toran, Y Trbojevic, D Turner, W VanGinneken, A Vsevoloshskaya, T Weggel, R Willen, E Willis, W Winn, D Wurtele, J Zhao, Y TI Muon collider design SO NUCLEAR PHYSICS B LA English DT Article; Proceedings Paper CT Symposium on Physics Potential and Development of mu(plus)mu(minus) Colliders CY DEC 13-15, 1995 CL SAN FRANCISCO, CA C1 STANFORD LINEAR ACCELERATOR CTR,STANFORD,CA 94309. UNIV CALIF BERKELEY,LAWRENCE BERKELEY LAB,BERKELEY,CA 94720. BINP,RU-630090 NOVOSIBIRSK,RUSSIA. FERMILAB NATL ACCELERATOR LAB,BATAVIA,IL 60510. ARGONNE NATL LAB,ARGONNE,IL 60439. UNIV CALIF LOS ANGELES,CTR ADV ACCELERATORS,LOS ANGELES,CA 90024. CONTINUOUS ELECTRON BEAM ACCELERATOR FACIL CTR,NEWPORT NEWS,VA 23606. UNIV VIRGINIA,CHARLOTTESVILLE,VA 22901. KEK,TSUKUBA,IBARAKI 305,JAPAN. DESY,HAMBURG,GERMANY. UNIV MISSISSIPPI,OXFORD,MS 38677. SUNY STONY BROOK,STONY BROOK,NY 11974. MIT,FRANCIS BITTER NATL MAGNET LAB,CAMBRIDGE,MA 02139. COLUMBIA UNIV,NEW YORK,NY 10027. FAIRFIELD UNIV,FAIRFIELD,CT 06430. UNIV CALIF BERKELEY,BERKELEY,CA 94720. RP Palmer, R (reprint author), BROOKHAVEN NATL LAB,UPTON,NY 11973, USA. RI wurtele, Jonathan/J-6278-2016; OI wurtele, Jonathan/0000-0001-8401-0297; Gallardo, Juan C/0000-0002-5191-3067; Torun, Yagmur/0000-0003-2336-6585 NR 65 TC 11 Z9 11 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 NOV PY 1996 SU 51A BP 61 EP 84 PG 24 WC Physics, Particles & Fields SC Physics GA VR872 UT WOS:A1996VR87200008 ER PT J AU Copi, CJ Schramm, DN Turner, MS AF Copi, CJ Schramm, DN Turner, MS TI Latest nucleosynthesis constraints on the baryon density of the universe SO NUCLEAR PHYSICS B LA English DT Article; Proceedings Paper CT 2nd Symposium on Dark Matter in the Universe CY FEB 14-16, 1996 CL SANTA MONICA, CA SP UCLA ID BIG-BANG NUCLEOSYNTHESIS; PRIMORDIAL NUCLEOSYNTHESIS; DEUTERIUM; ABUNDANCE; LITHIUM; HE-3 AB Big-bang nucleosynthesis plays a crucial role in constraining big-bang cosmology. Although the uncertainties in the observations of the light elements are governed by systematic effects, firm bounds on the density of baryons in the Universe can be set. On-going observations of deuterium in high-redshift quasar absorption systems will provide tight constraints on the density of baryons. C1 FERMILAB NATL ACCELERATOR LAB,NASA,FERMILAB ASTROPHYS CTR,BATAVIA,IL 60510. UNIV CHICAGO,ENRICO FERMI INST,DEPT ASTRON & ASTROPHYS,CHICAGO,IL 60637. RP Copi, CJ (reprint author), UNIV CHICAGO,ENRICO FERMI INST,DEPT PHYS,5630 ELLIS AVE,CHICAGO,IL 60637, USA. NR 25 TC 3 Z9 3 U1 0 U2 0 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0550-3213 J9 NUCL PHYS B JI Nucl. Phys. B PD NOV PY 1996 SU 51B BP 66 EP 70 DI 10.1016/S0920-5632(96)00484-7 PG 5 WC Physics, Particles & Fields SC Physics GA VY665 UT WOS:A1996VY66500010 ER PT J AU Rhie, SH Bennett, DP AF Rhie, SH Bennett, DP TI Search for earth mass planets and dark matter too SO NUCLEAR PHYSICS B LA English DT Article; Proceedings Paper CT 2nd Symposium on Dark Matter in the Universe CY FEB 14-16, 1996 CL SANTA MONICA, CA SP UCLA AB Gravitational microlensing is known for baryonic dark matter searches. Mere we show that microlensing also provides a unique tool for the detection of low mass planets (such as earths and neptunes) from the ground. A planetary system forms a binary lens (or, a multi-point lens), and we can determine the mass ratio of the planet with respect to the star and relative distance (= separation/Einstein ring radius) between the star and planet. Such a microlenisng planet search project requires a approximate to 2 m survey telescope, and a network of 1.5 - 2 m follow-up telescopes capable of monitoring stars in the Bulge on a 24-hour basis. During the off-season of the Galactic bulge, this network can be used for dark matter search by monitoring the stars in the LMC and SMC. C1 UNIV CALIF BERKELEY,CTR PARTICLE ASTROPHYS,BERKELEY,CA 94720. UNIV CALIF DAVIS,DEPT PHYS,DAVIS,CA 95616. UNIV NOTRE DAME,DEPT PHYS,NOTRE DAME,IN 46556. RP Rhie, SH (reprint author), LAWRENCE LIVERMORE NATL LAB,LIVERMORE,CA 94550, USA. NR 5 TC 16 Z9 16 U1 0 U2 0 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0550-3213 J9 NUCL PHYS B JI Nucl. Phys. B PD NOV PY 1996 SU 51B BP 86 EP 90 DI 10.1016/S0920-5632(96)00487-2 PG 5 WC Physics, Particles & Fields SC Physics GA VY665 UT WOS:A1996VY66500013 ER PT J AU Schriber, SO AF Schriber, SO TI Overview of advanced proton driver for neutron transmutation systems SO NUCLEAR PHYSICS B LA English DT Article; Proceedings Paper CT Symposium on Physics Potential and Development of mu(plus)mu(minus) Colliders CY DEC 13-15, 1995 CL SAN FRANCISCO, CA AB A linear accelerator for the driver of a mu-mu collider can easily be based on operating characteristics of the Los Alamos Neutron Science Center (LANSCE) linac, or can incorporate many of the advances that have been realized from the Accelerator Driven Transmutation Technologies (ADTT) studies, from the Accelerator Production of Tritium (APT) developments, and from the Strategic Defense Initiative (SDI) developments. RP Schriber, SO (reprint author), LOS ALAMOS NATL LAB,AOT DIV,MS H850,LOS ALAMOS,NM 87545, USA. NR 0 TC 1 Z9 1 U1 1 U2 1 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0550-3213 J9 NUCL PHYS B JI Nucl. Phys. B PD NOV PY 1996 SU 51A BP 109 EP 114 DI 10.1016/0920-5632(96)00421-5 PG 6 WC Physics, Particles & Fields SC Physics GA VR872 UT WOS:A1996VR87200012 ER PT J AU Goldhaber, G Boyle, B Bunclark, P Carter, D Couch, W Deustua, S Dopita, M Ellis, R Filippenko, AV Gabi, S Glazebrook, K Goobar, A Groom, D Hook, I Irwin, M Kim, A Kim, M Lee, J Matheson, T McMahon, R Newberg, H Pain, R Pennypacker, C Perlmutter, S Small, I AF Goldhaber, G Boyle, B Bunclark, P Carter, D Couch, W Deustua, S Dopita, M Ellis, R Filippenko, AV Gabi, S Glazebrook, K Goobar, A Groom, D Hook, I Irwin, M Kim, A Kim, M Lee, J Matheson, T McMahon, R Newberg, H Pain, R Pennypacker, C Perlmutter, S Small, I TI Cosmological time dilation using type Ia supernovae as clocks SO NUCLEAR PHYSICS B LA English DT Article; Proceedings Paper CT 2nd Symposium on Dark Matter in the Universe CY FEB 14-16, 1996 CL SANTA MONICA, CA SP UCLA AB Although there is little doubt at present that the redshift of distant galaxies is due to an expansion of the universe, we present in this paper a direct confirmation for the cosmological expansion. This work is based on the first results from a systematic search for high redshift Type Ia supernovae. We discovered over twenty seven SNe, before or at maximum light. In this paper we report on the first seven of these, with redshift z = 0.35 - 0.46. Type Ia SNe are known to be a homogeneous group of SNe, to first order, with very similar light curves, spectra and peak luminosities. In this paper we report that the light curves we observe rue all broadened (time dilated) as expected from the expanding universe hypothesis. Small variations from the expected 1 + z broadening of the light curve widths can be attributed to a width-brightness correlation that has been observed for nearby SNe (z < 0.1). We show in this paper the first clear observation of the cosmological time dilation for macroscopic objects. C1 UNIV CALIF BERKELEY,CTR PARTICLE ASTROPHYS,BERKELEY,CA 94720. UNIV STOCKHOLM,STOCKHOLM,SWEDEN. UNIV CAMBRIDGE,INST ASTRON,CAMBRIDGE CB2 1TN,ENGLAND. ROYAL GREENWICH OBSERV,CAMBRIDGE,ENGLAND. FERMILAB NATL ACCELERATOR LAB,BATAVIA,IL 60510. AUSTRALIAN NATL UNIV,MSSSO,CANBERRA,ACT 2601,AUSTRALIA. UNIV NEW S WALES,KENSINGTON,NSW 2033,AUSTRALIA. RP Goldhaber, G (reprint author), UNIV CALIF BERKELEY,LAWRENCE BERKELEY LAB,BERKELEY,CA 94720, USA. RI Perlmutter, Saul/I-3505-2015; Glazebrook, Karl/N-3488-2015 OI Perlmutter, Saul/0000-0002-4436-4661; Glazebrook, Karl/0000-0002-3254-9044 NR 24 TC 1 Z9 1 U1 0 U2 0 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0550-3213 J9 NUCL PHYS B JI Nucl. Phys. B PD NOV PY 1996 SU 51B BP 123 EP 127 DI 10.1016/S0920-5632(96)00493-8 PG 5 WC Physics, Particles & Fields SC Physics GA VY665 UT WOS:A1996VY66500019 ER PT J AU Pratt, MR Alcock, C Allsman, RA Alves, D Axelrod, TS Becker, AC Bennett, DP Cook, KH Freeman, KC Griest, K Guern, J Lehner, MJ Marshall, SL Peterson, BA Quinn, PJ Rodgers, AW Stubbs, CW Sutherland, W Welch, DL AF Pratt, MR Alcock, C Allsman, RA Alves, D Axelrod, TS Becker, AC Bennett, DP Cook, KH Freeman, KC Griest, K Guern, J Lehner, MJ Marshall, SL Peterson, BA Quinn, PJ Rodgers, AW Stubbs, CW Sutherland, W Welch, DL TI The MACHO Project 2nd year LMC microlensing results and dark matter implications SO NUCLEAR PHYSICS B LA English DT Article; Proceedings Paper CT 2nd Symposium on Dark Matter in the Universe CY FEB 14-16, 1996 CL SANTA MONICA, CA SP UCLA ID LARGE MAGELLANIC CLOUD; GRAVITATIONAL LENSING EXPERIMENT; GALACTIC HALO; GALAXY; CANDIDATE; DIRECTION; OBJECTS; DWARFS; BULGE; STARS AB The MACHO Project is searching for galactic dark matter in the form of massive compact halo objects (Machos). Millions of stars in the Large Magellanic Cloud (LMC), Small Magellanic Cloud (SMC), and Galactic bulge are photometrically monitored in an attempt to detect rare gravitational microlensing events caused by otherwise invisible Machos. Analysis of two years of photometry on 8.5 million stars in the LMC reveals 8 candidate microlensing events, far more than the similar to 1 event expected from lensing by low-mass stars in known galactic populations. From these eight events we estimate the optical depth towards the LMC from events with 2 < (t) over cap < 200 days to be tau(2)(200) approximate to 2.9(-0.9)(+1.4) x 10(-7). This exceeds the optical depth of 0.5 x 10(-7) expected from known stars and is to be compared with an optical depth of 4.7 x 10(-7) predicted for a ''standard'' halo composed entirely of Machos. The total mass in this lensing population is approximate to 2(-0.7)(+1.2) x 10(11) M(.) (within 50 kpc from the Galactic center). Event timescales yield a most probable Macho mass of 0.5(-0.2)(+0.3) M(.), although this value is quite model dependent. C1 UNIV CALIF BERKELEY,CTR PARTICLE ASTROPHYS,BERKELEY,CA 94720. LAWRENCE LIVERMORE NATL LAB,LIVERMORE,CA 94550. AUSTRALIAN NATL UNIV,SUPERCOMP FACIL,CANBERRA,ACT 0200,AUSTRALIA. UNIV CALIF DAVIS,DEPT PHYS,DAVIS,CA 95616. AUSTRALIAN NATL UNIV,MT STROMLO & SIDING SPRING OBSERV,WESTON,ACT 2611,AUSTRALIA. UNIV CALIF SAN DIEGO,DEPT PHYS,LA JOLLA,CA 92093. EUROPEAN SO OBSERV,D-85748 GARCHING,GERMANY. UNIV OXFORD,DEPT PHYS,OXFORD OX1 3RH,ENGLAND. MCMASTER UNIV,HAMILTON,ON L8S 4M1,CANADA. RP Pratt, MR (reprint author), UNIV WASHINGTON,BOX 351580,SEATTLE,WA 98195, USA. RI Quinn, Peter/B-3638-2013; Stubbs, Christopher/C-2829-2012; OI Stubbs, Christopher/0000-0003-0347-1724; Welch, Doug/0000-0002-2350-0898; Lehner, Matthew/0000-0003-4077-0985 NR 37 TC 2 Z9 2 U1 0 U2 0 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0550-3213 J9 NUCL PHYS B JI Nucl. Phys. B PD NOV PY 1996 SU 51B BP 131 EP 140 DI 10.1016/S0920-5632(96)00494-X PG 10 WC Physics, Particles & Fields SC Physics GA VY665 UT WOS:A1996VY66500020 ER PT J AU Lehner, MJ Alcock, C Allsman, RA Alves, D Axelrod, TS Becker, A Bennett, DP Cook, KH Freeman, KC Griest, K Guern, J Marshall, SL Peterson, BA Pratt, MR Quinn, PJ Rodgers, AW Stubbs, CW Sutherland, W AF Lehner, MJ Alcock, C Allsman, RA Alves, D Axelrod, TS Becker, A Bennett, DP Cook, KH Freeman, KC Griest, K Guern, J Marshall, SL Peterson, BA Pratt, MR Quinn, PJ Rodgers, AW Stubbs, CW Sutherland, W TI The MACHO project constraints on low mass Machos in the Galactic Halo SO NUCLEAR PHYSICS B LA English DT Article; Proceedings Paper CT 2nd Symposium on Dark Matter in the Universe CY FEB 14-16, 1996 CL SANTA MONICA, CA SP UCLA AB The MACHO project has been monitoring about ten million stars. in the Large Magellanic Cloud in the search for gravitational microlensing events caused by massive compact halo objects (Machos) in the halo of the Milky Way. The standard analysis for well sampled, long duration microlensing is sensitive to objects with masses 10(-5) less than or similar to m less than or similar to 1M(.). However, a different analysis method sensitive to short duration events extends the sensitivity of the experiment to lower masses. Combining the results of the analyses of the first two years of data from the LMC shows that Machos with masses in the range 2.5 x 10(-7) < m < 8.1 x 10(-2) M(.) cannot make up the entire mass of a standard spherical dark halo. C1 UNIV CALIF BERKELEY,CTR PARTICLE ASTROPHYS,BERKELEY,CA 94720. LAWRENCE LIVERMORE NATL LAB,LIVERMORE,CA 94550. AUSTRALIAN NATL UNIV,SUPERCOMP FACIL,CANBERRA,ACT 0200,AUSTRALIA. UNIV CALIF DAVIS,DEPT PHYS,DAVIS,CA 95616. AUSTRALIAN NATL UNIV,MT STROMLO & SIDING SPRING OBSERV,WESTON,ACT 2611,AUSTRALIA. UNIV WASHINGTON,DEPT PHYS,SEATTLE,WA 98195. UNIV WASHINGTON,DEPT ASTRON,SEATTLE,WA 98195. UNIV OXFORD,DEPT PHYS,OXFORD OX1 3RH,ENGLAND. RP Lehner, MJ (reprint author), UNIV CALIF SAN DIEGO,DEPT PHYS,LA JOLLA,CA 92093, USA. RI Quinn, Peter/B-3638-2013; Stubbs, Christopher/C-2829-2012; OI Stubbs, Christopher/0000-0003-0347-1724; Lehner, Matthew/0000-0003-4077-0985 NR 8 TC 0 Z9 0 U1 0 U2 0 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0550-3213 J9 NUCL PHYS B JI Nucl. Phys. B PD NOV PY 1996 SU 51B BP 141 EP 145 DI 10.1016/S0920-5632(96)00495-1 PG 5 WC Physics, Particles & Fields SC Physics GA VY665 UT WOS:A1996VY66500021 ER PT J AU Gyuk, G Gates, E Turner, MS AF Gyuk, G Gates, E Turner, MS TI Microlensing towards the Galactic bulge and Galactic dark matter SO NUCLEAR PHYSICS B LA English DT Article; Proceedings Paper CT 2nd Symposium on Dark Matter in the Universe CY FEB 14-16, 1996 CL SANTA MONICA, CA SP UCLA ID GRAVITATIONAL LENSING EXPERIMENT; HALO; DIRECTION; DISCOVERY; OBJECTS; GALAXY; MODEL AB Extensive modeling of the Galactic disk and bulge is used to study the implications of the observed microlensing events towards the bulge. We constrain models to fit both the microlensing data and more traditional constraints such as rotation curve measurements, limits on the disk surface density, and escape velocity from the Galaxy. We find that even if the Galactic bulge has a bar-like configuration, substantial dark matter must exist in either a heavy disk or a massive bar or both. Disentanglement of the bar and disk contributions requires mapping of the optical depth across the Galactic center. We discuss the range over which such mapping would be useful. C1 FERMILAB NATL ACCELERATOR LAB,NASA,FERMILAB ASTROPHYS CTR,BATAVIA,IL 60510. UNIV CHICAGO,ENRICO FERMI INST,DEPT ASTRON,CHICAGO,IL 60637. UNIV CHICAGO,ENRICO FERMI INST,DEPT ASTROPHYS,CHICAGO,IL 60637. RP Gyuk, G (reprint author), UNIV CHICAGO,ENRICO FERMI INST,DEPT PHYS,5630 ELLIS AVE,CHICAGO,IL 60637, USA. NR 31 TC 0 Z9 0 U1 0 U2 0 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0550-3213 J9 NUCL PHYS B JI Nucl. Phys. B PD NOV PY 1996 SU 51B BP 146 EP 151 DI 10.1016/S0920-5632(96)00496-3 PG 6 WC Physics, Particles & Fields SC Physics GA VY665 UT WOS:A1996VY66500022 ER PT J AU Garren, A Courant, E Gallardo, J Palmer, R Trbojevic, D Johnstone, C Ng, KY AF Garren, A Courant, E Gallardo, J Palmer, R Trbojevic, D Johnstone, C Ng, KY TI Design of the muon collider lattice: Present status SO NUCLEAR PHYSICS B LA English DT Article; Proceedings Paper CT Symposium on Physics Potential and Development of mu(plus)mu(minus) Colliders CY DEC 13-15, 1995 CL SAN FRANCISCO, CA AB We discuss a preliminary design for a high luminosity 4 TeV center of mass mu(+)mu(-) collider ring. C1 UNIV CALIF LOS ANGELES,CTR ADV ACCELERATORS,LOS ANGELES,CA 90095. BROOKHAVEN NATL LAB,UPTON,NY 11793. STANFORD LINEAR ACCELERATOR LAB,STANFORD,CA 94309. FERMILAB NATL ACCELERATOR LAB,BATAVIA,IL 60510. RP Garren, A (reprint author), LAWRENCE BERKELEY LAB,BERKELEY,CA 94720, USA. OI Gallardo, Juan C/0000-0002-5191-3067 NR 11 TC 0 Z9 0 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 NOV PY 1996 SU 51A BP 148 EP 157 DI 10.1016/0920-5632(96)00426-4 PG 10 WC Physics, Particles & Fields SC Physics GA VR872 UT WOS:A1996VR87200017 ER PT J AU Bennett, DP Alcock, C Allsman, RA Alves, D Axelrod, TS Becker, A Cook, KH Freeman, KC Griest, K Guern, J Lehner, MJ Marshall, SL Minniti, D Peterson, BA Pratt, MR Quinn, PJ Rhie, SH Rodgers, AW Stubbs, CW Sutherland, W Welch, D AF Bennett, DP Alcock, C Allsman, RA Alves, D Axelrod, TS Becker, A Cook, KH Freeman, KC Griest, K Guern, J Lehner, MJ Marshall, SL Minniti, D Peterson, BA Pratt, MR Quinn, PJ Rhie, SH Rodgers, AW Stubbs, CW Sutherland, W Welch, D TI A binary lensing event toward the LMC: Observations and dark matter implications SO NUCLEAR PHYSICS B LA English DT Article; Proceedings Paper CT 2nd Symposium on Dark Matter in the Universe CY FEB 14-16, 1996 CL SANTA MONICA, CA SP UCLA ID HALO AB The MACHO collaboration has recently analyzed 2.1 years of photometric data for about 8.5 million stars in the Large Magellanic Cloud (LMC). This analysis has revealed 8 candidate microlensing events and a total microlensing optical depth of tau(meas) = 2.9(-0.9)(+1.4) x 10(-7). This significantly exceeds the number of events (1.1) and the microlensing optical depth predicted from known stellar populations: tau(back) = 5.1 x 10(-8), but it is consistent with models in which about half of the standard dark halo mass is composed of Machos of mass similar to 0.5M(.). One of these 8 events appears to be a binary lensing event with a caustic crossing that is partially resolved, and the measured caustic crossing time allows us to estimate the distance to the lenses. Under the assumption that the source star is a single star and not a short period binary, we show that the lensing objects are very likely to reside in the LMC. However, if we assume that the optical depth for LMC-LMC lensing is large enough to account for our entire lensing signal, then the binary event does not appear to be consistent with lensing of a single LMC source star by a binary residing in the LMC. Thus, while the binary lens may indeed reside in the LMC, there is no indication that most of the lenses reside in the LMC. C1 LAWRENCE LIVERMORE NATL LAB,LIVERMORE,CA 94550. UNIV CALIF DAVIS,DEPT PHYS,DAVIS,CA 95616. UNIV NOTRE DAME,DEPT PHYS,NOTRE DAME,IN 46556. AUSTRALIAN NATL UNIV,MT STROMLO & SIDING SPRING OBSERV,CANBERRA,ACT 2611,AUSTRALIA. UNIV WASHINGTON,DEPT PHYS,SEATTLE,WA 98195. UNIV WASHINGTON,DEPT ASTRON,SEATTLE,WA 98195. UNIV CALIF SAN DIEGO,DEPT PHYS,LA JOLLA,CA 92093. EUROPEAN SO OBSERV,D-8046 GARCHING,GERMANY. UNIV OXFORD,DEPT PHYS,OXFORD OX1 3RH,ENGLAND. MCMASTER UNIV,DEPT PHYS,HAMILTON,ON L8S 4M1,CANADA. MCMASTER UNIV,DEPT ASTRON,HAMILTON,ON L8S 4M1,CANADA. AUSTRALIAN NATL UNIV,SUPERCOMP FACIL,CANBERRA,ACT 0200,AUSTRALIA. RP Bennett, DP (reprint author), UNIV CALIF BERKELEY,CTR PARTICLE ASTROPHYS,BERKELEY,CA 94720, USA. RI Quinn, Peter/B-3638-2013; Stubbs, Christopher/C-2829-2012; OI Stubbs, Christopher/0000-0003-0347-1724; Welch, Doug/0000-0002-2350-0898; Lehner, Matthew/0000-0003-4077-0985 NR 13 TC 33 Z9 33 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 NOV PY 1996 SU 51B BP 152 EP 156 DI 10.1016/S0920-5632(96)00497-5 PG 5 WC Physics, Particles & Fields SC Physics GA VY665 UT WOS:A1996VY66500023 ER PT J AU Gates, E Gyuk, G Turner, MS AF Gates, E Gyuk, G Turner, MS TI Gravitational microlensing and halo dark matter SO NUCLEAR PHYSICS B LA English DT Article; Proceedings Paper CT 2nd Symposium on Dark Matter in the Universe CY FEB 14-16, 1996 CL SANTA MONICA, CA SP UCLA ID LENSING EXPERIMENT; GALACTIC BULGE; GALAXY; DIRECTION; MASS; DISCOVERY; DENSITY; MODEL AB By means of extensive galactic modeling we study the implications of the more than 100 microlensing events that have now been observed for the composition of the dark halo of the Galaxy. We consider Galactic models with luminous and dark disk components, a bulge, and a dark halo consisting of both MACHOs and cold dark matter with each component being described by several observationally motivated parameters. This initial model space is constrained by the observational data, including rotation curve, local projected mass density, and microlensing rates toward the LMC and bulge. Based on the currently published data and a conservative, minimal set of observational constraints an all-MACHO halo cannot yet be excluded, although in most viable models of the Galaxy the halo MACHO fraction is between 0% and 30%, consistent with expectations for a universe whose primary component is cold dark matter. We also consider the implications of the preliminary 2nd year MACHO results, which suggest a higher optical depth toward the LMC. In this case the likelihood function for the halo MACHO fraction has a peak around 20% - 40%, and the halo MACHO fraction is less than 60% in most models. C1 UNIV CHICAGO,ENRICO FERMI INST,DEPT ASTRON & ASTROPHYS,CHICAGO,IL 60637. UNIV CHICAGO,ENRICO FERMI INST,DEPT PHYS,CHICAGO,IL 60637. RP Gates, E (reprint author), FERMILAB NATL ACCELERATOR LAB,NASA,FERMILAB ASTROPHYS CTR,BATAVIA,IL 60510, USA. NR 41 TC 0 Z9 0 U1 0 U2 0 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0550-3213 J9 NUCL PHYS B JI Nucl. Phys. B PD NOV PY 1996 SU 51B BP 157 EP 162 DI 10.1016/S0920-5632(96)00498-7 PG 6 WC Physics, Particles & Fields SC Physics GA VY665 UT WOS:A1996VY66500024 ER PT J AU Green, MA AF Green, MA TI Superconducting magnets for a muon collider SO NUCLEAR PHYSICS B LA English DT Article; Proceedings Paper CT Symposium on Physics Potential and Development of mu(plus)mu(minus) Colliders CY DEC 13-15, 1995 CL SAN FRANCISCO, CA AB The existence of a muon collider will be dependent on the use of superconducting magnets. Superconducting magnets for the mu(-)mu(+) collider will be found in the following locations: the pi(-)pi(+) capture system, the muon phase rotation system, the muon cooling system, the recirculating acceleration system, the collider ring, and the collider detector system. This report describes superconducting magnets for each of these sections except the detector. In addition to superconducting magnets, superconducting RF cavities will be found in the recirculating accelerator sections and the collider ring. The use of superconducting magnets is dictated by the need for high magnetic fields in order to reduce the length of various machine components. The performance of all of the superconducting magnets will be affected the energy deposited from muon decay products. RP Green, MA (reprint author), UNIV CALIF BERKELEY,ERNEST ORLANDO LAWRENCE BERKELEY NATL LAB,BERKELEY,CA 94720, USA. NR 7 TC 0 Z9 0 U1 1 U2 1 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0550-3213 J9 NUCL PHYS B JI Nucl. Phys. B PD NOV PY 1996 SU 51A BP 158 EP 167 DI 10.1016/0920-5632(96)00427-6 PG 10 WC Physics, Particles & Fields SC Physics GA VR872 UT WOS:A1996VR87200018 ER PT J AU Gallardo, JC Palmer, RB AF Gallardo, JC Palmer, RB TI Final focus system for a muon collider: A test model SO NUCLEAR PHYSICS B LA English DT Article; Proceedings Paper CT Symposium on Physics Potential and Development of mu(plus)mu(minus) Colliders CY DEC 13-15, 1995 CL SAN FRANCISCO, CA AB The present scenario for a high luminosity 4 TeV on center of mass muon collider requires a beta function beta* approximate to 3 mm at the interaction point. We discuss a test model of a basic layout which satisfies the requirements although it is not fully realistic. C1 STANFORD LINEAR ACCELERATOR LAB,STANFORD,CA 94309. RP Gallardo, JC (reprint author), BROOKHAVEN NATL LAB,CTR ACCELERATOR PHYS,UPTON,NY 11793, USA. OI Gallardo, Juan C/0000-0002-5191-3067 NR 13 TC 0 Z9 0 U1 0 U2 0 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0550-3213 J9 NUCL PHYS B JI Nucl. Phys. B PD NOV PY 1996 SU 51A BP 168 EP 171 DI 10.1016/0920-5632(96)00428-8 PG 4 WC Physics, Particles & Fields SC Physics GA VR872 UT WOS:A1996VR87200019 ER PT J AU Chen, PS AF Chen, PS TI Beam-beam interaction in muon colliders SO NUCLEAR PHYSICS B LA English DT Article; Proceedings Paper CT Symposium on Physics Potential and Development of mu(plus)mu(minus) Colliders CY DEC 13-15, 1995 CL SAN FRANCISCO, CA ID QUANTUM BEAMSTRAHLUNG AB Inspired by the hybrid nature of muon colliders, we investigate the classical and quantum effects induced by the mu(+)mu(-) beam-beam interaction. We show that although the tendency of emittance dilution appears to be substantial in a single pass, it nevertheless quickly saturates. We also show that, with muons, there is negligible beamstrahlung, and thus negligible pair production from them. In addition, the beamstrahlung of electrons from the nearby decay of muons does not pose a problem. For the case of coherent e(+)e(-) pair creation from muons, opposite to our earlier notion, we now recognize that this process is also largely suppressed. Finally, we suggest that the beam-beam tune-shift can be suppressed by applying a plasma at the interaction point in the muon collider. RP Chen, PS (reprint author), STANFORD UNIV,STANFORD LINEAR ACCELERATOR CTR,STANFORD,CA 94309, USA. NR 22 TC 1 Z9 1 U1 0 U2 0 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0550-3213 J9 NUCL PHYS B JI Nucl. Phys. B PD NOV PY 1996 SU 51A BP 179 EP 185 DI 10.1016/0920-5632(96)00430-6 PG 7 WC Physics, Particles & Fields SC Physics GA VR872 UT WOS:A1996VR87200021 ER PT J AU Farrar, GR Kolb, EW AF Farrar, GR Kolb, EW TI Light photinos as dark matter SO NUCLEAR PHYSICS B LA English DT Article; Proceedings Paper CT 2nd Symposium on Dark Matter in the Universe CY FEB 14-16, 1996 CL SANTA MONICA, CA SP UCLA AB In models of low-energy supersymmetry (SUSY) without dimension-three supersymmetry breaking terms, the photino and gluino are very light. In most of these models the lightest R-odd, color-singlet state containing a gluino, the R(0), has a mass in the 1-2 GeV range and the slightly lighter photino, <(gamma)over tilde>, would be the relic R-odd species. For the photino masses-considered here, previous calculations resulted in an unacceptable photino relic abundance. But we point out that processes other than photino self-annihilation determine the relic abundance when the photino and R(0) are close in mass. We find that the photino relic abundance is most sensitive to the R(0)-to-<(gamma)over tilde> mass ratio, and within model uncertainties, a critical density in photinos may be obtained for an R(0)-to-<(gamma)over tilde> mass ratio in the range 1.2 to 2.2. We propose photinos in the mass range of 500 MeV to 1.6 GeV as a dark matter candidate, and discuss a strategy to test the hypothesis. C1 FERMILAB NATL ACCELERATOR LAB,NASA,FERMILAB ASTROPHYS CTR,BATAVIA,IL 60510. UNIV CHICAGO,ENRICO FERMI INST,DEPT ASTRON & ASTROPHYS,CHICAGO,IL 60637. RP Farrar, GR (reprint author), RUTGERS STATE UNIV,DEPT PHYS & ASTRON,POB 849,PISCATAWAY,NJ 08855, USA. NR 2 TC 1 Z9 1 U1 0 U2 0 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0550-3213 J9 NUCL PHYS B JI Nucl. Phys. B PD NOV PY 1996 SU 51B BP 188 EP 195 DI 10.1016/S0920-5632(96)00509-9 PG 8 WC Physics, Particles & Fields SC Physics GA VY665 UT WOS:A1996VY66500029 ER PT J AU Atac, M AF Atac, M TI Detector possibilities for a mu(+)mu(-) collider SO NUCLEAR PHYSICS B LA English DT Article; Proceedings Paper CT Symposium on Physics Potential and Development of mu(plus)mu(minus) Colliders CY DEC 13-15, 1995 CL SAN FRANCISCO, CA C1 UNIV CALIF LOS ANGELES,LOS ANGELES,CA 90095. RP Atac, M (reprint author), FERMILAB NATL ACCELERATOR LAB,BATAVIA,IL 60510, USA. NR 4 TC 0 Z9 0 U1 0 U2 0 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0550-3213 J9 NUCL PHYS B JI Nucl. Phys. B PD NOV PY 1996 SU 51A BP 207 EP 209 DI 10.1016/0920-5632(96)00434-3 PG 3 WC Physics, Particles & Fields SC Physics GA VR872 UT WOS:A1996VR87200025 ER PT J AU Hagmann, C Kinion, D Stoeffl, W vanBibber, K Daw, E McBride, J Peng, H Rosenberg, LJ Xin, H Laveigne, J Sikivie, P Sullivan, NS Tanner, DB Moltz, D AF Hagmann, C Kinion, D Stoeffl, W vanBibber, K Daw, E McBride, J Peng, H Rosenberg, LJ Xin, H Laveigne, J Sikivie, P Sullivan, NS Tanner, DB Moltz, D TI First results from a second generation galactic axion experiment SO NUCLEAR PHYSICS B LA English DT Article; Proceedings Paper CT 2nd Symposium on Dark Matter in the Universe CY FEB 14-16, 1996 CL SANTA MONICA, CA SP UCLA ID CP INVARIANCE; COSMIC AXIONS; PARTICLES; SEARCH AB We report first results from a large-scale search for dark matter axions. The experiment probes axion masses of 1.3-13 mu eV at a sensitivity which is about 50 times higher than previous pilot experiments. We have already scanned part of this mass range at a sensitivity better than required to see at least one generic axion model, the KSVZ axion. Data taking at full sensitivity commenced in February 1996 and scanning the proposed mass range will require three years. C1 MIT,DEPT PHYS,CAMBRIDGE,MA 02139. UNIV FLORIDA,DEPT PHYS,GAINESVILLE,FL 32611. UNIV CALIF BERKELEY,LAWRENCE BERKELEY LAB,DIV NUCL SCI,BERKELEY,CA 94720. FERMILAB NATL ACCELERATOR LAB,BATAVIA,IL 60510. RUSSIAN ACAD SCI,INST NUCL RES,MOSCOW 117312,RUSSIA. RP Hagmann, C (reprint author), LAWRENCE LIVERMORE NATL LAB,7000 EAST AVE,LIVERMORE,CA 94550, USA. NR 14 TC 11 Z9 11 U1 0 U2 0 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0550-3213 J9 NUCL PHYS B JI Nucl. Phys. B PD NOV PY 1996 SU 51B BP 209 EP 212 DI 10.1016/S0920-5632(96)00516-6 PG 4 WC Physics, Particles & Fields SC Physics GA VY665 UT WOS:A1996VY66500032 ER PT J AU Mokhov, NV AF Mokhov, NV TI Comparison of backgrounds in detectors for LHC, NLC and mu(+)mu(-) colliders SO NUCLEAR PHYSICS B LA English DT Article; Proceedings Paper CT Symposium on Physics Potential and Development of mu(plus)mu(minus) Colliders CY DEC 13-15, 1995 CL SAN FRANCISCO, CA AB Background levels in detectors at future high-luminosity colliders of three different types - pp, e(+)e(-) and mu(+)mu(-) - are analyzed. Two sources - debris from the collision points and those from an accelerator tunnel - are studied. It is shown that hadron, electron and muon colliders are similar and very different at the same time with respect to background origin, integrated radiation levels and instantaneous rates of particles in the detectors. RP Mokhov, NV (reprint author), FERMILAB NATL ACCELERATOR LAB,POB 500,BATAVIA,IL 60510, USA. NR 24 TC 3 Z9 3 U1 0 U2 0 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0550-3213 J9 NUCL PHYS B JI Nucl. Phys. B PD NOV PY 1996 SU 51A BP 210 EP 218 DI 10.1016/0920-5632(96)00435-5 PG 9 WC Physics, Particles & Fields SC Physics GA VR872 UT WOS:A1996VR87200026 ER PT J AU Shutt, T Akerib, DS Barnes, PD Bauer, D Brink, P Cabrera, B Caldwell, DO Chugg, B Clarke, RM DaSilva, A Davies, A Dougherty, BL Emes, J Gaitskell, RJ Golwala, SR Hale, D Haller, EE Irwin, KD Knowlton, WB Kuzminov, V Lu, A Muno, M Nam, SW Novikov, V Penn, MJ Ross, RR Sadoulet, B Seitz, D Smith, A Smith, G Sonnenschein, A Stockwell, W Taylor, JD Therrien, R Trumbull, TL White, S Yellin, S Young, BA AF Shutt, T Akerib, DS Barnes, PD Bauer, D Brink, P Cabrera, B Caldwell, DO Chugg, B Clarke, RM DaSilva, A Davies, A Dougherty, BL Emes, J Gaitskell, RJ Golwala, SR Hale, D Haller, EE Irwin, KD Knowlton, WB Kuzminov, V Lu, A Muno, M Nam, SW Novikov, V Penn, MJ Ross, RR Sadoulet, B Seitz, D Smith, A Smith, G Sonnenschein, A Stockwell, W Taylor, JD Therrien, R Trumbull, TL White, S Yellin, S Young, BA TI Progress of the cryogenic dark matter search (CDMS) experiment. SO NUCLEAR PHYSICS B LA English DT Article; Proceedings Paper CT 2nd Symposium on Dark Matter in the Universe CY FEB 14-16, 1996 CL SANTA MONICA, CA SP UCLA ID DETECTORS; PHONON AB We report on progress of the CDMS experiment, which seeks to detect WIMP dark matter through its interactions in a particle detector operated in a low radioactivity environment. We have developed novel cryogenic detectors which discriminate between nuclear recoils from WIMPs and electron recoils from background photons. We describe the experiment and discuss recent progress, including first operation of a cryogenic detector in the low radioactivity cryostat in June of 1996. C1 UNIV CALIF BERKELEY,DEPT PHYS,BERKELEY,CA 94720. UNIV CALIF BERKELEY,DEPT MAT SCI & MINERAL ENGN,BERKELEY,CA 94720. LAWRENCE BERKELEY LAB,BERKELEY,CA 94720. STANFORD UNIV,DEPT PHYS,STANFORD,CA 94305. CASE WESTERN RESERVE UNIV,DEPT PHYS,CLEVELAND,OH 44106. UNIV CALIF SANTA BARBARA,DEPT PHYS,SANTA BARBARA,CA 93106. SANTA CLARA UNIV,DEPT PHYS,SANTA CLARA,CA 95053. RUSSIAN ACAD SCI,INST NUCL RES,BAKSAN NEUTRINO OBSERV,MOSCOW,RUSSIA. RP Shutt, T (reprint author), UNIV CALIF BERKELEY,CTR PARTICLE ASTROPHYS,BERKELEY,CA 94720, USA. NR 20 TC 3 Z9 3 U1 0 U2 0 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0550-3213 J9 NUCL PHYS B JI Nucl. Phys. B PD NOV PY 1996 SU 51B BP 318 EP 322 DI 10.1016/S0920-5632(96)00523-3 PG 5 WC Physics, Particles & Fields SC Physics GA VY665 UT WOS:A1996VY66500049 ER PT J AU Morel, JE Lorence, LJ Kensek, RP Halbleib, JA Sloan, DP AF Morel, JE Lorence, LJ Kensek, RP Halbleib, JA Sloan, DP TI A hybrid multigroup/continuous-energy Monte Carlo method for solving the Boltzmonn-Fokker-Planck equation SO NUCLEAR SCIENCE AND ENGINEERING LA English DT Article ID ELECTRON-PHOTON TRANSPORT; CODES AB A hybrid multigroup/continuous-energy Monte Carlo algorithm is developed for solving the Boltzmann-Fokker-Planck equation. This algorithm differs significantly from previous charged-particle Monte Carlo algorithms. Most importantly, it can be used to perform both forward and adjoint transport calculations, using the same basic multigroup cross-section data. The new algorithm is fully described, computationally tested and compared with a standard condensed history algorithm for coupled electron-photon transport calculations. C1 SANDIA NATL LABS,ALBUQUERQUE,NM 87185. CH2M HILL INC,OAK RIDGE,TN 37830. RP Morel, JE (reprint author), LOS ALAMOS NATL LAB,LOS ALAMOS,NM 87545, USA. NR 24 TC 10 Z9 10 U1 0 U2 0 PU AMER NUCLEAR SOCIETY PI LA GRANGE PK PA 555 N KENSINGTON AVENUE, LA GRANGE PK, IL 60525 SN 0029-5639 J9 NUCL SCI ENG JI Nucl. Sci. Eng. PD NOV PY 1996 VL 124 IS 3 BP 369 EP 389 PG 21 WC Nuclear Science & Technology SC Nuclear Science & Technology GA VQ601 UT WOS:A1996VQ60100001 ER PT J AU Cramer, SN AF Cramer, SN TI Forward-adjoint Monte Carlo coupling with no statistical error propagation SO NUCLEAR SCIENCE AND ENGINEERING LA English DT Article AB Methods for coupling multiple forward and adjoint radiation transport Monte Carlo calculations with no statistical error propagation are presented. Correlated forward and adjoint particle histories are uniformly initialized on arbitrarily placed intermediate source boundaries throughout the calculational system. In applying the method to multilegged duct streaming problems, these source boundaries are placed at the duct leg intersections. The necessary forward and adjoint fluxes for the coupling procedure are each computed from an opposite-mode calculation. The no-error-propagation feature is the result of an exact correlation of all phase-space variables for coupled forward-adjoint particle histories at each boundary. For ducts of more than two legs, next-event estimation between forward and adjoint collision sires across arbitrarily placed intermediate scoring boundaries is necessary to achieve the variable cor relation. Comparison of calculational results between the coupled and standard methods for two- and three-legged ducts are presented. RP Cramer, SN (reprint author), OAK RIDGE NATL LAB,POB 2008,OAK RIDGE,TN 37831, USA. NR 19 TC 13 Z9 13 U1 0 U2 1 PU AMER NUCLEAR SOCIETY PI LA GRANGE PK PA 555 N KENSINGTON AVENUE, LA GRANGE PK, IL 60525 SN 0029-5639 J9 NUCL SCI ENG JI Nucl. Sci. Eng. PD NOV PY 1996 VL 124 IS 3 BP 398 EP 416 PG 19 WC Nuclear Science & Technology SC Nuclear Science & Technology GA VQ601 UT WOS:A1996VQ60100003 ER PT J AU Difilippo, FC Renier, JP Worley, BA AF Difilippo, FC Renier, JP Worley, BA TI Thermalization of neutrons in graphite: Status and error analysis SO NUCLEAR SCIENCE AND ENGINEERING LA English DT Article AB Calculations related to the temperature coefficient of reactivity of enriched gas-cooled reactors show the high sensitivity of this parameter to the proper description of thermalization effects in the moderator. Additionally, the calculation of the temperature dependence of the inelastic-scattering cross section with current ENDF/B formalisms correlates the errors of the cross sections as functions of the temperature. Neglecting this temperature correlation introduces unnecessary conservatism in the estimation of the error of the reactivity coefficient. These two facts drove our efforts to characterize the present status of the inelastic cross section of graphite and to calculate its covariance file. The ENDF/B evaluation of the scattering matrix S(alpha, beta, T) is still based on the approximations (incoherent component only) and phonon spectra of the early 1960s. Subsequent measurements showed that the structure observed in S(alpha, beta, T) cannot be described using the incoherent approximation, and soon after the availability of highly intense neutron beams and large specimens of pyrolitic graphite have allowed the direct measurement of elastic constants of relevance for a better calculation of the phonon spectra. Calculations of the probability distributions of the moment and energy transfer, alpha and beta, in a Maxwellian spectrum allow us to define a range of alpha and beta for which comparison of experimental and theoretical data are of most interest for reactor analysis, and to point out regions of deficient resolution or excessive details in the present alpha, beta mesh used in the ENDF/B files. Because the phonon spectrum defines S(alpha, beta, T), mathematical formulas have been found that allow the calculation of the covariance matrix of S by propagating the errors of the phonon spectra. RP Difilippo, FC (reprint author), OAK RIDGE NATL LAB,POB 2008,BLDG 6025,OAK RIDGE,TN 37831, USA. NR 8 TC 3 Z9 3 U1 0 U2 0 PU AMER NUCLEAR SOCIETY PI LA GRANGE PK PA 555 N KENSINGTON AVENUE, LA GRANGE PK, IL 60525 SN 0029-5639 J9 NUCL SCI ENG JI Nucl. Sci. Eng. PD NOV PY 1996 VL 124 IS 3 BP 465 EP 472 PG 8 WC Nuclear Science & Technology SC Nuclear Science & Technology GA VQ601 UT WOS:A1996VQ60100008 ER PT J AU Dong, DJ Vandegrift, GF AF Dong, DJ Vandegrift, GF TI Kinetics of dissolution of uranium metal foil by alkaline hydrogen peroxide SO NUCLEAR SCIENCE AND ENGINEERING LA English DT Article AB To develop a new process for the production of Mo-99 using low-enriched uranium targets, uranium dissolution in alkaline hydrogen peroxide was studied. Molybdenum-99 is a parent of the widely used medical isotope Tc-99m. The rates of uranium dissolution in alkaline hydrogen peroxide solution were measured in an open, batch-type reactor and were found to be a 0.25th order reaction with respect to equilibrium hydrogen peroxide concentration. In general, uranium dissolution can be classified as a tow-base (<0.2 M hydroxide) and a high-base (>0.2 M hydroxide) process. In the low-base process, both the equilibrium hydrogen peroxide and the hydroxide concentrations affect the rate of uranium dissolution. In the high-base process, uranium dissolution is independent of alkali concentration; the presence of base affects only the equilibrium concentration of hydrogen peroxide. An empirical kinetics model is proposed and discussed. C1 ARGONNE NATL LAB,DIV CHEM TECHNOL,ARGONNE,IL 60439. NR 23 TC 7 Z9 7 U1 0 U2 1 PU AMER NUCLEAR SOCIETY PI LA GRANGE PK PA 555 N KENSINGTON AVENUE, LA GRANGE PK, IL 60525 SN 0029-5639 J9 NUCL SCI ENG JI Nucl. Sci. Eng. PD NOV PY 1996 VL 124 IS 3 BP 473 EP 481 PG 9 WC Nuclear Science & Technology SC Nuclear Science & Technology GA VQ601 UT WOS:A1996VQ60100009 ER PT J AU Danon, Y Moore, MS Koehler, PE Littleton, PE Miller, GG Ott, MA Rowton, LJ Taylor, WA Wilhelmy, JB Yates, MA Carlson, AD Hill, NW Harper, R Hilko, R AF Danon, Y Moore, MS Koehler, PE Littleton, PE Miller, GG Ott, MA Rowton, LJ Taylor, WA Wilhelmy, JB Yates, MA Carlson, AD Hill, NW Harper, R Hilko, R TI Fission cross-section measurements of the odd-odd isotopes Pa-232, Np-238, and Np-236 SO NUCLEAR SCIENCE AND ENGINEERING LA English DT Article AB Transmutation of actinide waste into fission products could be enhanced by using resonance fission of odd-odd target materials; those of interest are Pa-232, Np-238, and Am-242. Fission cross-section measurements of two of these short-lived materials were performed al Los Alamos National Laboratory. Samples were produced by the (d,2n) reaction in the Los Alamos ion Beam Facility followed by fast radiochemistry to separate the odd-odd target of interest. The fission cross section of the nanogram samples was measured in a high intensity pulsed neutron beam produced by 800-MeV proton spallation. Using this procedure, the fission cross sections of the 1.3-day Pa-232 and 2.1-day Np-238 were successfully measured in the energy range from 0.01 eV to 50 keV. The fission cross section of the relatively long-life isotope Np-236 was also measured in the same system while the short half-life isotopes were being prepared. The results and resonance analysis are presented. C1 RENSSELAER POLYTECH INST,DEPT NUCL ENGN & ENGN PHYS,TROY,NY 12180. LOS ALAMOS NATL LAB,LOS ALAMOS,NM 87545. NIST,GAITHERSBURG,MD 20899. OAK RIDGE NATL LAB,OAK RIDGE,TN 37831. EG&G ENERGY MEASUREMENTS INC,LOS ALAMOS,NM 87544. RI Danon, Yaron/B-5159-2009; OI Koehler, Paul/0000-0002-6717-0771 NR 9 TC 4 Z9 6 U1 1 U2 2 PU AMER NUCLEAR SOCIETY PI LA GRANGE PK PA 555 N KENSINGTON AVENUE, LA GRANGE PK, IL 60525 SN 0029-5639 J9 NUCL SCI ENG JI Nucl. Sci. Eng. PD NOV PY 1996 VL 124 IS 3 BP 482 EP 491 PG 10 WC Nuclear Science & Technology SC Nuclear Science & Technology GA VQ601 UT WOS:A1996VQ60100010 ER PT J AU Ahluwalia, RK Geyer, HK AF Ahluwalia, RK Geyer, HK TI The GC computer code for flow sheet simulation of pyrochemical processing of spent nuclear fuels SO NUCLEAR TECHNOLOGY LA English DT Article DE pyrochemical processing; spent-fuel treatment; equilibrium chemistry ID FISSION-PRODUCTS; CHEMICAL-STATE; OXIDE FUELS AB The GC computer code has been developed for flout sheet simulation of pyrochemical processing of spent nuclear fuel. It utilizes a robust algorithm SLG for analyzing simultaneous chemical reactions between species distributed across many phases. Models have been developed for analysis of the oxide fuel reduction process, salt recovery by electrochemical decomposition of lithium oxide, uranium separation from the reduced fuel by electrorefining, and extraction of fission products into liquid cadmium. The versatility of GC is demonstrated by applying the code to a flow sheet of current interest. RP Ahluwalia, RK (reprint author), ARGONNE NATL LAB,TECHNOL DEV DIV,9700 S CASS AVE,ARGONNE,IL 60439, USA. NR 10 TC 9 Z9 9 U1 0 U2 1 PU AMER NUCLEAR SOCIETY PI LA GRANGE PK PA 555 N KENSINGTON AVENUE, LA GRANGE PK, IL 60525 SN 0029-5450 J9 NUCL TECHNOL JI Nucl. Technol. PD NOV PY 1996 VL 116 IS 2 BP 180 EP 195 PG 16 WC Nuclear Science & Technology SC Nuclear Science & Technology GA VN280 UT WOS:A1996VN28000005 ER PT J AU Hsu, CLW Ritter, JA AF Hsu, CLW Ritter, JA TI Treatment of simulated high-level radioactive waste with formic acid: Bench-scale study on hydrogen evolution SO NUCLEAR TECHNOLOGY LA English DT Article DE noble metals; formic acid; catalysis AB At the Savannah River Site, the Defense Waste Processing Facility (DWPF) was constructed to vitrify high-level radioactive liquid waste in borosilicate glass for permanent storage. Formic acid, which serves as both an acid and a reducing agent, is used to treat the washed alkaline sludge during melter feed preparation primarily to improve the processability of the feed and to reduce mercury to its Zero state for steam stripping. The high-level sludge is composed of many transition metal hydroxides. Among them, there are small quantities of platinum group metals such as ruthenium, rhodium, and palladium that are fission products. During the treatment of simulated sludge with formic acid, significant amounts of hydrogen were generated when the platinum group metals were included in the sludge. Apparently the noble metals in the sludge were reduced to their zero states and caused formic acid to decompose catalytically into hydrogen and carbon dioxide, usually with an induction period. The production of hydrogen gas presented the DWPF with a safety issue. Therefore, the objective of this research was to gain a fundamental understanding of what controlled the hydrogen evolution so that a practical solution to the safety issue could be obtained. A bench-scale parametric study revealed the following: increasing the amount of formic acid added to the sludge increased the hydrogen generation rate dramatically; once the catalysts were activated, the hydrogen generation rate decreased significantly with a lowering of the temperature of the sludge; the relative catalytic activities of the noble metals in the sludge-decreased in the following order: rhodium > ruthenium much greater than palladium; ammonium ions were generated catalytically from the reaction between formic acid and nitrate; and when present, the noble metals caused higher upward drifts of the sludge pH. Based on these bench-scale results, in conjunction with a pilot-scale study, a forced air purge and hydrogen monitoring system, along with a temperature controlled safety shutdown algorithm, were developed. RP Hsu, CLW (reprint author), WESTINGHOUSE SAVANNAH RIVER CO,SAVANNAH RIVER TECHNOL CTR,AIKEN,SC 29808, USA. NR 14 TC 3 Z9 3 U1 0 U2 4 PU AMER NUCLEAR SOCIETY PI LA GRANGE PK PA 555 N KENSINGTON AVENUE, LA GRANGE PK, IL 60525 SN 0029-5450 J9 NUCL TECHNOL JI Nucl. Technol. PD NOV PY 1996 VL 116 IS 2 BP 196 EP 207 PG 12 WC Nuclear Science & Technology SC Nuclear Science & Technology GA VN280 UT WOS:A1996VN28000006 ER PT J AU Uryasev, SP Samanta, PK AF Uryasev, SP Samanta, PK TI Failure-dependent test, repair, and shutdown strategies: Reducing the impact of common-cause failures SO NUCLEAR TECHNOLOGY LA English DT Article DE probabilistic risk assessments; common-cause failures; technical specifications AB Failure-dependent testing implies a test of redundant components (or trains) when the failure of one component has been detected. The purpose of such testing is to detect any common-cause failures (CCFs) of multiple components so that a corrective action, such as repair or plant shutdown, can be taken to reduce the residence time of multiple failures. This type of testing focuses on reducing the conditional risk of CCFs. Formulas are developed for calculating the conditional failure probability of a two-train system with different test, repair, and shutdown strategics. A methodology is presented, with an example calculation, showing the risk effectiveness of failure-dependent strategies for emergency diesel generators in nuclear power plants. Four alternative actions after the identification of a failure of one component are analyzed: (a) not carrying out any additional testing, (b) testing the redundant components and shutting down the plant if a CCF is present, (c) emergency repair of the failed component in a given time (less than the allowed outage time), and (d) additional testing of redundant components after the repair of the failed component. RP Uryasev, SP (reprint author), BROOKHAVEN NATL LAB,DEPT ADV TECHNOL,BLDG 130,UPTON,NY 11973, USA. RI URYASEV, Stan/O-5231-2014 OI URYASEV, Stan/0000-0001-6950-3966 NR 18 TC 0 Z9 0 U1 0 U2 1 PU AMER NUCLEAR SOCIETY PI LA GRANGE PK PA 555 N KENSINGTON AVENUE, LA GRANGE PK, IL 60525 SN 0029-5450 J9 NUCL TECHNOL JI Nucl. Technol. PD NOV PY 1996 VL 116 IS 2 BP 245 EP 256 PG 12 WC Nuclear Science & Technology SC Nuclear Science & Technology GA VN280 UT WOS:A1996VN28000010 ER PT J AU Huang, ZP Petty, JT OQuinn, B Longmire, JL Brown, NC Jett, JH Keller, RA AF Huang, ZP Petty, JT OQuinn, B Longmire, JL Brown, NC Jett, JH Keller, RA TI Large DNA fragment sizing by flow cytometry: Application to the characterization of P1 artificial chromosome (PAC) clones SO NUCLEIC ACIDS RESEARCH LA English DT Article ID FIELD GEL-ELECTROPHORESIS; FLUORESCENCE DETECTION; SIZE DETERMINATION; ESCHERICHIA-COLI; CIRCULAR DNAS; NUCLEIC-ACIDS; MOLECULES; SEPARATION; CLONING; YEAST AB A flow cytometry-based, ultrasensitive fluorescence detection technique is used to size individual DNA fragments up to 167 kb in length. Application of this technology to the sizing of P1 artificial chromosomes (PACs) in both linear and supercoiled forms is described. It is demonstrated that this method is well suited to characterizing PAC/BAC clones and wilt be very useful for the analysis of large insert libraries. Fluorescence bursts are recorded as individual, dye stained DNA fragments pass through a low power, focused, continuous laser beam. The magnitudes of the fluorescence bursts are linearly proportional to the lengths of the DNA fragments. The histograms of the burst sizes are generated in <3 min with <1 pg of DNA. Results on linear fragments are consistent with those obtained by pulsed-field gel electrophoresis. In comparison with pulsed-field gel electrophoresis, sizing of large DNA fragments by this approach is more accurate, much faster, requires much less DNA, and is independent of the DNA conformation. C1 LOS ALAMOS NATL LAB,CHEM SCI & TECHNOL DIV,LOS ALAMOS,NM 87545. LOS ALAMOS NATL LAB,DIV LIFE SCI,LOS ALAMOS,NM 87545. FU NCRR NIH HHS [RR-01315] NR 25 TC 45 Z9 46 U1 0 U2 2 PU OXFORD UNIV PRESS UNITED KINGDOM PI OXFORD PA WALTON ST JOURNALS DEPT, OXFORD, ENGLAND OX2 6DP SN 0305-1048 J9 NUCLEIC ACIDS RES JI Nucleic Acids Res. PD NOV 1 PY 1996 VL 24 IS 21 BP 4202 EP 4209 DI 10.1093/nar/24.21.4202 PG 8 WC Biochemistry & Molecular Biology SC Biochemistry & Molecular Biology GA VT249 UT WOS:A1996VT24900016 PM 8932373 ER PT J AU Bollanti, S Cotton, R DiLazzaro, P Flora, F Letardi, T Lisi, N Batani, D Conti, A Mauri, A Palladino, L Reale, A Belli, M Ianzini, F Scafati, A Reale, L Tabocchini, MA Albertano, P Faenov, AY Pikuz, T Oesterheld, A AF Bollanti, S Cotton, R DiLazzaro, P Flora, F Letardi, T Lisi, N Batani, D Conti, A Mauri, A Palladino, L Reale, A Belli, M Ianzini, F Scafati, A Reale, L Tabocchini, MA Albertano, P Faenov, AY Pikuz, T Oesterheld, A TI Development and characterisation of an XeCl excimer laser-generated soft-X-ray plasma source and its applications SO NUOVO CIMENTO DELLA SOCIETA ITALIANA DI FISICA D-CONDENSED MATTER ATOMIC MOLECULAR AND CHEMICAL PHYSICS FLUIDS PLASMAS BIOPHYSICS LA English DT Article ID PERFORMANCE; EMISSION AB A large-aperture, long-pulse XeCl excimer laser has been used to generate a soft-X-ray plasma source. Several laser optical configurations have been employed to optimise X-ray emission, including positive-branch unstable resonators and injection by seeding the gain region of the laser with a small commercial excimer laser, resulting in power densities in the range 10(12)-10(14) Wcm(-2). The characteristics of the plasma source for each different laser configuration and for different target materials are investigated. The most suitable source conditions (spectral energy distribution, time duration, etc.) for specific applications are discussed. C1 UNIV MILAN,DIPARTIMENTO FIS,I-20133 MILAN,ITALY. IST NAZL FIS NUCL,I-20133 MILAN,ITALY. UNIV AQUILA,DIPARTIMENTO FIS,I-67100 LAQUILA,ITALY. IST NAZL FIS NUCL,LNGS,LAQUILA,ITALY. IST SUPER SANITA,FIS LAB,I-00161 ROME,ITALY. IST NAZL FIS NUCL,SEZ SANITA,I-00161 ROME,ITALY. UNIV ROMA TOR VERGATA,DIPARTIMENTO BIOL,I-00133 ROME,ITALY. VNIIFTRI,NPO,MISDC,MENDELEYEVSK,RUSSIA. LLNL,LIVERMORE,CA. RP Bollanti, S (reprint author), ENEA,DIPARTIMENTO INNOVAZ SETTORE FIS APPLICATA,CTR RIC FRASCATI,CP 65,I-00044 FRASCATI,ITALY. RI Tabocchini, Maria Antonella/A-4035-2010 OI Tabocchini, Maria Antonella/0000-0003-3244-6106 NR 25 TC 34 Z9 34 U1 0 U2 4 PU EDITRICE COMPOSITORI BOLOGNA PI BOLOGNA PA VIA STALINGRADO 97/2, I-40128 BOLOGNA, ITALY SN 0392-6737 J9 NUOVO CIMENTO D JI Nuovo Cimento Soc. Ital. Fis. D-Condens. Matter At. Mol. Chem. Phys. Fluids Plasmas Biophys. PD NOV PY 1996 VL 18 IS 11 BP 1241 EP 1255 DI 10.1007/BF02453259 PG 15 WC Physics, Multidisciplinary SC Physics GA WG159 UT WOS:A1996WG15900001 ER PT J AU Compton, L AF Compton, L TI Appreciates hardcopy reviews SO ONLINE LA English DT Letter RP Compton, L (reprint author), SANDIA NATL LABS,POB 5800,ALBUQUERQUE,NM 87185, USA. NR 0 TC 2 Z9 2 U1 0 U2 0 PU ONLINE INC PI WILTON PA 462 DANBURY RD, WILTON, CT 06897-2126 SN 0146-5422 J9 ONLINE JI Online PD NOV-DEC PY 1996 VL 20 IS 6 BP 6 EP 6 PG 1 WC Information Science & Library Science SC Information Science & Library Science GA VQ764 UT WOS:A1996VQ76400002 ER PT J AU Dickey, FM Holswade, SC AF Dickey, FM Holswade, SC TI Gaussian laser beam profile shaping SO OPTICAL ENGINEERING LA English DT Article DE lossless Gaussian beam shaping; irradiance uniformity; Fourier optics ID UNIFORM BEAM; DESIGN AB A method for converting single-mode Gaussian beams into beams with uniform irradiance profiles is described. The design is based on a Fourier transform relation between the input and output beam functions. The efficacy of the solution is shown to depend on a parameter that contains the product of the widths of the input and output beams. Problems associated with errors in system alignment and scale are discussed. Numerical illustrations and experimental results are presented. (C) 1996 Society of Photo-Optical Instrumentation Engineers. RP Dickey, FM (reprint author), SANDIA NATL LABS,POB 5800,ALBUQUERQUE,NM 87185, USA. NR 16 TC 48 Z9 51 U1 1 U2 4 PU SOC PHOTO-OPT INSTRUM ENG PI BELLINGHAM PA PO BOX 10, BELLINGHAM, WA 98227-0010 SN 0091-3286 J9 OPT ENG JI Opt. Eng. PD NOV PY 1996 VL 35 IS 11 BP 3285 EP 3295 DI 10.1117/1.601069 PG 11 WC Optics SC Optics GA VT596 UT WOS:A1996VT59600030 ER PT J AU LutherDavies, B Samoc, M Swiatkiewicza, J Samoc, A Woodruff, M Trebino, R Delong, KW AF LutherDavies, B Samoc, M Swiatkiewicza, J Samoc, A Woodruff, M Trebino, R Delong, KW TI Diagnostics of femtosecond laser pulses using films of poly(p-phenylenevinylene) SO OPTICS COMMUNICATIONS LA English DT Article ID POLY(PARA-PHENYLENE VINYLENE); ABSORPTION; RETRIEVAL; POLYMERS AB Thin films of poly( p-phenylenevinylene) have been used to diagnose femtosecond Ti-sapphire laser pulses using frequency resolved optical gating or third order intensity autocorrelation in the self-diffraction geometry; and using a two-photon fluorescence autocorrelation technique. C1 SANDIA NATL LABS,LIVERMORE,CA 94551. RP LutherDavies, B (reprint author), AUSTRALIAN NATL UNIV,RES SCH PHYS SCI & ENGN,LASER PHYS CTR,CANBERRA,ACT 0200,AUSTRALIA. RI Samoc, Marek/A-5501-2008; Luther-Davies, Barry/D-7294-2013 OI Samoc, Marek/0000-0002-5404-2455; Luther-Davies, Barry/0000-0002-2747-5036 NR 19 TC 9 Z9 9 U1 0 U2 3 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0030-4018 J9 OPT COMMUN JI Opt. Commun. PD NOV 1 PY 1996 VL 131 IS 4-6 BP 301 EP 306 DI 10.1016/0030-4018(96)00280-5 PG 6 WC Optics SC Optics GA VN287 UT WOS:A1996VN28700015 ER PT J AU Dixit, SN Feit, MD Perry, MD Powell, HT AF Dixit, SN Feit, MD Perry, MD Powell, HT TI Designing fully continuous phase screens for tailoring focal-plane irradiance profiles SO OPTICS LETTERS LA English DT Article ID ALGORITHM; PLATES; HOLOGRAPHY AB An iterative algorithm for constructing fully continuous phase screens for tailoring far-field intensity profiles is presented. The algorithm is robust, stable, and, if run properly, maintains the continuous nature of the phase throughout the iterative process. The iterative procedure is applied to generate continuous phase screens to produce a 12th-power super-Gaussian far-field intensity profile. (C) 1996 Optical Society of America RP Dixit, SN (reprint author), LAWRENCE LIVERMORE NATL LAB,LIVERMORE,CA 94550, USA. RI Feit, Michael/A-4480-2009 NR 13 TC 76 Z9 81 U1 0 U2 14 PU OPTICAL SOC AMER PI WASHINGTON PA 2010 MASSACHUSETTS AVE NW, WASHINGTON, DC 20036 SN 0146-9592 J9 OPT LETT JI Opt. Lett. PD NOV 1 PY 1996 VL 21 IS 21 BP 1715 EP 1717 DI 10.1364/OL.21.001715 PG 3 WC Optics SC Optics GA VP372 UT WOS:A1996VP37200003 PM 19881777 ER PT J AU Lin, SY Hietala, VM Wang, L Jones, ED AF Lin, SY Hietala, VM Wang, L Jones, ED TI Highly dispersive photonic band-gap prism SO OPTICS LETTERS LA English DT Article AB We propose the concept of a photonic band-gap (PEG) prism based on two-dimensional PBG structures and realize it in the millimeter-wave spectral regime. We recognize the highly nonlinear dispersion of PEG materials near Brillouin zone edges and utilize the dispersion to achieve strong prism action. Such a PEG prism is very compact if operated in the optical regime, similar to 20 mu m in size for lambda similar to 700 nm, and can serve as a dispersive element for building ultracompact miniature spectrometers. (C) 1996 Optical Society of America RP Lin, SY (reprint author), SANDIA NATL LABS,POB 5800,ALBUQUERQUE,NM 87185, USA. NR 9 TC 187 Z9 196 U1 0 U2 14 PU OPTICAL SOC AMER PI WASHINGTON PA 2010 MASSACHUSETTS AVE NW, WASHINGTON, DC 20036 SN 0146-9592 J9 OPT LETT JI Opt. Lett. PD NOV 1 PY 1996 VL 21 IS 21 BP 1771 EP 1773 DI 10.1364/OL.21.001771 PG 3 WC Optics SC Optics GA VP372 UT WOS:A1996VP37200022 PM 19881796 ER PT J AU Slansky, R AF Slansky, R TI Forty-five years of many-body theory: What is the relation of field theory and representations of Lie algebras? SO PHILOSOPHICAL MAGAZINE B-PHYSICS OF CONDENSED MATTER STATISTICAL MECHANICS ELECTRONIC OPTICAL AND MAGNETIC PROPERTIES LA English DT Article AB In celebration of David Pines's (70+n)th birthday, this essay asks the question whether there is a truly fundamental relationship between the Hilbert spaces of a quantum theory and the representation theory of Lie algebras. In trying to sharpen this question we briefly review representation theory and then conclude with a well known example where the Hilbert space of a simple field theory is an irreducible representation of a Lie algebra. RP Slansky, R (reprint author), LOS ALAMOS NATL LAB,DIV THEORET,MS B210,LOS ALAMOS,NM 87545, USA. NR 14 TC 0 Z9 0 U1 0 U2 0 PU TAYLOR & FRANCIS LTD PI LONDON PA ONE GUNDPOWDER SQUARE, LONDON, ENGLAND EC4A 3DE SN 0141-8637 J9 PHILOS MAG B JI Philos. Mag. B-Phys. Condens. Matter Stat. Mech. Electron. Opt. Magn. Prop. PD NOV PY 1996 VL 74 IS 5 BP 435 EP 446 DI 10.1080/01418639608240346 PG 12 WC Materials Science, Multidisciplinary; Mechanics; Physics, Applied; Physics, Condensed Matter SC Materials Science; Mechanics; Physics GA VR702 UT WOS:A1996VR70200004 ER PT J AU Hammel, PC Scalapino, DJ AF Hammel, PC Scalapino, DJ TI Local microstructure and the cuprate spin gap puzzle SO PHILOSOPHICAL MAGAZINE B-PHYSICS OF CONDENSED MATTER STATISTICAL MECHANICS ELECTRONIC OPTICAL AND MAGNETIC PROPERTIES LA English DT Article ID T-J MODEL; PHASE-DIAGRAM; NORMAL STATE; SUPERCONDUCTORS AB Here we propose that the spin gap properties of the underdoped cuprates may be associated with a local inhomogeneous structure in the CuO2 planes. Experimental evidence for such structure is discussed along with suggestions regarding how such local structure might give rise to a spin gap. C1 UNIV CALIF SANTA BARBARA,DEPT PHYS,SANTA BARBARA,CA 93106. RP Hammel, PC (reprint author), LOS ALAMOS NATL LAB,CONDENSED MATTER & THERMAL PHYS GRP,POB 1663,LOS ALAMOS,NM 87545, USA. RI Hammel, P Chris/O-4845-2014 OI Hammel, P Chris/0000-0002-4138-4798 NR 37 TC 15 Z9 15 U1 0 U2 1 PU TAYLOR & FRANCIS LTD PI LONDON PA ONE GUNDPOWDER SQUARE, LONDON, ENGLAND EC4A 3DE SN 0141-8637 J9 PHILOS MAG B JI Philos. Mag. B-Phys. Condens. Matter Stat. Mech. Electron. Opt. Magn. Prop. PD NOV PY 1996 VL 74 IS 5 BP 523 EP 528 DI 10.1080/01418639608240354 PG 6 WC Materials Science, Multidisciplinary; Mechanics; Physics, Applied; Physics, Condensed Matter SC Materials Science; Mechanics; Physics GA VR702 UT WOS:A1996VR70200012 ER PT J AU Slichter, CP Corey, RL Curro, NJ DeSoto, SM OHara, K Imai, T Kini, AM Wang, HH Geiser, U Williams, JM Yoshimura, K Katoh, M Kosuge, K AF Slichter, CP Corey, RL Curro, NJ DeSoto, SM OHara, K Imai, T Kini, AM Wang, HH Geiser, U Williams, JM Yoshimura, K Katoh, M Kosuge, K TI Nuclear magnetic resonance and electron spins: Some history, ancient and in the making SO PHILOSOPHICAL MAGAZINE B-PHYSICS OF CONDENSED MATTER STATISTICAL MECHANICS ELECTRONIC OPTICAL AND MAGNETIC PROPERTIES LA English DT Article ID ORGANIC SUPERCONDUCTOR; CUPRATE SUPERCONDUCTORS; RELAXATION RATE; NMR; YBA2CU3O7; STATE; KAPPA-(BEDT-TTF)2CUBR; TEMPERATURES; LA2CUO4; GAP AB Scaling relationships for NMR spin-lattice reIaxation time T-1 and Gaussian transverse relaxation time T-2G are reviewed and applied to analyse experiments in the normal state of YBa2Cu4O8. Studies of T-2G in the superconducting state are analysed using the theory of Pines and Wrobel to show a preference for d-state orbital pairing over anisotropic s-state. Data on C-13 NMR in the normal and superconducting state of the two dimensional organic conductor (ET)(2)Cu[N(CN)(2)]Br are presented and shown to have great similarity to that of the cuprates. C1 UNIV ILLINOIS,MAT RES LAB,URBANA,IL 61801. ARGONNE NATL LAB,DIV CHEM & MAT SCI,ARGONNE,IL 60439. KYOTO UNIV,FAC SCI,DEPT CHEM,KYOTO 606,JAPAN. RP Slichter, CP (reprint author), UNIV ILLINOIS,DEPT PHYS,1110 W GREEN ST,URBANA,IL 61801, USA. RI Kini, Aravinda/F-4467-2012; Curro, Nicholas/D-3413-2009 OI Curro, Nicholas/0000-0001-7829-0237 NR 41 TC 11 Z9 11 U1 1 U2 2 PU TAYLOR & FRANCIS LTD PI LONDON PA ONE GUNDPOWDER SQUARE, LONDON, ENGLAND EC4A 3DE SN 0141-8637 J9 PHILOS MAG B JI Philos. Mag. B-Phys. Condens. Matter Stat. Mech. Electron. Opt. Magn. Prop. PD NOV PY 1996 VL 74 IS 5 BP 545 EP 561 PG 17 WC Materials Science, Multidisciplinary; Mechanics; Physics, Applied; Physics, Condensed Matter SC Materials Science; Mechanics; Physics GA VR702 UT WOS:A1996VR70200014 ER PT J AU Martindale, JA Hammel, PC AF Martindale, JA Hammel, PC TI Oxygen nuclear magnetic resonance on the 90 K plateau of YBa2Cu3O7-delta SO PHILOSOPHICAL MAGAZINE B-PHYSICS OF CONDENSED MATTER STATISTICAL MECHANICS ELECTRONIC OPTICAL AND MAGNETIC PROPERTIES LA English DT Article ID RELAXATION RATES; PLANAR COPPER; SITES; STATE; O-17 AB We examine the body of O-17 nuclear magnetic resonance (NMR) data obtained in samples of YBa2Cu3O7-delta with T-c greater than or similar to 90 K. We point out significant deviations from typical metallic behaviour, contrary to conventional characterizations of these data. Furthermore, there is a surprisingly strong sample-to-sample variation in the O-17 NMR properties, given the narrow range of oxygen content. We suggest that this strong sample variability merits further study. C1 LOS ALAMOS NATL LAB,CONDENSED MATTER & THERMAL PHYS GRP,LOS ALAMOS,NM 87545. RI Hammel, P Chris/O-4845-2014 OI Hammel, P Chris/0000-0002-4138-4798 NR 12 TC 8 Z9 8 U1 0 U2 0 PU TAYLOR & FRANCIS LTD PI LONDON PA ONE GUNDPOWDER SQUARE, LONDON, ENGLAND EC4A 3DE SN 0141-8637 J9 PHILOS MAG B JI Philos. Mag. B-Phys. Condens. Matter Stat. Mech. Electron. Opt. Magn. Prop. PD NOV PY 1996 VL 74 IS 5 BP 573 EP 578 DI 10.1080/01418639608240358 PG 6 WC Materials Science, Multidisciplinary; Mechanics; Physics, Applied; Physics, Condensed Matter SC Materials Science; Mechanics; Physics GA VR702 UT WOS:A1996VR70200016 ER PT J AU Frauenfelder, H AF Frauenfelder, H TI Proteins: A challenging many-body problem SO PHILOSOPHICAL MAGAZINE B-PHYSICS OF CONDENSED MATTER STATISTICAL MECHANICS ELECTRONIC OPTICAL AND MAGNETIC PROPERTIES LA English DT Article ID HOLE-BURNING SPECTROSCOPY; X-RAY-DIFFRACTION; CONFORMATIONAL-CHANGES; SOLVENT VISCOSITY; LIGAND-BINDING; HEME-PROTEINS; MYOGLOBIN; DYNAMICS; MOTIONS AB Proteins are the biopolymers that perform essentially all functions in living systems. They are many-body systems with properties far different from those of the condensed matter that is usually considered by physicists. From the viewpoint of physics, the most important property is the energy landscape. Recent experimental and theoretical work suggests that the energy landscape is arranged in a hierarchy, but the details remain to be discovered. RP LOS ALAMOS NATL LAB, CTR NONLINEAR STUDIES, LOS ALAMOS, NM 87545 USA. NR 38 TC 1 Z9 1 U1 0 U2 0 PU TAYLOR & FRANCIS LTD PI ABINGDON PA 4 PARK SQUARE, MILTON PARK, ABINGDON OX14 4RN, OXON, ENGLAND SN 0141-8637 J9 PHILOS MAG B JI Philos. Mag. B-Phys. Condens. Matter Stat. Mech. Electron. Opt. Magn. Prop. PD NOV PY 1996 VL 74 IS 5 BP 579 EP 585 DI 10.1080/01418639608240359 PG 7 WC Materials Science, Multidisciplinary; Mechanics; Physics, Applied; Physics, Condensed Matter SC Materials Science; Mechanics; Physics GA VR702 UT WOS:A1996VR70200017 ER PT J AU Scalapino, DJ Trugman, SA AF Scalapino, DJ Trugman, SA TI Local antiferromagnetic correlations and d(x2-y2) pairing SO PHILOSOPHICAL MAGAZINE B-PHYSICS OF CONDENSED MATTER STATISTICAL MECHANICS ELECTRONIC OPTICAL AND MAGNETIC PROPERTIES LA English DT Article ID HIGH-TEMPERATURE SUPERCONDUCTORS; YBA2CU3O7; SYMMETRY; STATE; MODEL AB The high T-c cuprate superconductors doped near half-filling have short-range antiferromagnetic correlations. Here we describe an intuitive local picture of why, if pairing occurs in the presence of short-range antiferromagnetic correlations, the orbital state will have d(x2-y2) symmetry. C1 LOS ALAMOS NATL LAB,LOS ALAMOS,NM 87545. RP Scalapino, DJ (reprint author), UNIV CALIF SANTA BARBARA,DEPT PHYS,SANTA BARBARA,CA 93106, USA. NR 12 TC 24 Z9 24 U1 2 U2 2 PU TAYLOR & FRANCIS LTD PI LONDON PA ONE GUNDPOWDER SQUARE, LONDON, ENGLAND EC4A 3DE SN 0141-8637 J9 PHILOS MAG B JI Philos. Mag. B-Phys. Condens. Matter Stat. Mech. Electron. Opt. Magn. Prop. PD NOV PY 1996 VL 74 IS 5 BP 607 EP 610 DI 10.1080/01418639608240361 PG 4 WC Materials Science, Multidisciplinary; Mechanics; Physics, Applied; Physics, Condensed Matter SC Materials Science; Mechanics; Physics GA VR702 UT WOS:A1996VR70200019 ER PT J AU Bedell, KS Engelbrecht, J AF Bedell, KS Engelbrecht, J TI Local Fermi liquids: Where have all the instabilities gone? SO PHILOSOPHICAL MAGAZINE B-PHYSICS OF CONDENSED MATTER STATISTICAL MECHANICS ELECTRONIC OPTICAL AND MAGNETIC PROPERTIES LA English DT Article ID HUBBARD-MODEL; INFINITE DIMENSIONS; FERROMAGNETISM; SR1-XLAXTIO3 AB We present the properties of Fermi liquids with the microscopic constraint of a local (i.e. momentum independent) self-energy. With this constraint, the forward-scattering sum rule imposes strong limitations on the Fermi-liquid parameters, which rule out any Pomeranchuk instabilities. For both attractive and repulsive interactions, ferromagnetism and phase separation are suppressed. Superconductivity is possible in an s-wave channel only. We also study the approach to the metal-insulator transition and find a Wilson ratio approaching the value 2. This ratio and other properties of Sr1-xLaxTiO3 are all consistent with the local Fermi-liquid scenario. C1 LOS ALAMOS NATL LAB,CTR MAT SCI,LOS ALAMOS,NM 87545. LOS ALAMOS NATL LAB,THEORET DIV MSB262,LOS ALAMOS,NM 87545. RP Bedell, KS (reprint author), BOSTON COLL,DEPT PHYS,CHESTNUT HILL,MA 02167, USA. NR 16 TC 0 Z9 0 U1 0 U2 0 PU TAYLOR & FRANCIS LTD PI LONDON PA ONE GUNDPOWDER SQUARE, LONDON, ENGLAND EC4A 3DE SN 0141-8637 J9 PHILOS MAG B JI Philos. Mag. B-Phys. Condens. Matter Stat. Mech. Electron. Opt. Magn. Prop. PD NOV PY 1996 VL 74 IS 5 BP 633 EP 640 DI 10.1080/01418639608240363 PG 8 WC Materials Science, Multidisciplinary; Mechanics; Physics, Applied; Physics, Condensed Matter SC Materials Science; Mechanics; Physics GA VR702 UT WOS:A1996VR70200021 ER PT J AU Lacerda, A Yatskar, A Schmiedeshoff, GM Beyermann, WP Canfield, PC AF Lacerda, A Yatskar, A Schmiedeshoff, GM Beyermann, WP Canfield, PC TI High-field, low-temperature magnetoresistance of single crystalline heavy fermion YbNi2B2C SO PHILOSOPHICAL MAGAZINE B-PHYSICS OF CONDENSED MATTER STATISTICAL MECHANICS ELECTRONIC OPTICAL AND MAGNETIC PROPERTIES LA English DT Article ID CECU6 AB We have measured transverse (B perpendicular to I) and longitudinal (B parallel to I) magnetoresistance on a single crystalline sample of YbNi2B2C in a temperature range from 50 mK to 20 K and in magnetic fields to 18 T. A remarkably large anisotropic transverse magnetoresistance was found when applying a magnetic field parallel or perpendicular to the c axis of the tetragonal crystallographic structure. A pronounced maximum at 12T develops below 4K in the transverse magnetoresistance when the magnetic field is applied along the c axis, whereas a minimum is found at 7T below 4K. Above 5K both configurations (B parallel to c and B perpendicular to c) show a negative magnetoresistance. Finally, a change in sign is observed in the transverse magnetoresistance for B perpendicular to c below 1K. C1 UNIV CALIF RIVERSIDE, DEPT PHYS, RIVERSIDE, CA 92521 USA. IOWA STATE UNIV SCI & TECHNOL, AMES, IA 50011 USA. AMES LAB, AMES, IA 50011 USA. OCCIDENTAL COLL, DEPT PHYS, LOS ANGELES, CA 90041 USA. RP Lacerda, A (reprint author), LOS ALAMOS NATL LAB, NATL HIGH MAGNET FIELD LAB, MAIL STOP E536, LOS ALAMOS, NM 87545 USA. RI Canfield, Paul/H-2698-2014 NR 6 TC 10 Z9 10 U1 0 U2 4 PU TAYLOR & FRANCIS LTD PI LONDON PA ONE GUNDPOWDER SQUARE, LONDON, ENGLAND EC4A 3DE SN 0141-8637 J9 PHILOS MAG B JI Philos. Mag. B-Phys. Condens. Matter Stat. Mech. Electron. Opt. Magn. Prop. PD NOV PY 1996 VL 74 IS 5 BP 641 EP 645 DI 10.1080/01418639608240364 PG 5 WC Materials Science, Multidisciplinary; Mechanics; Physics, Applied; Physics, Condensed Matter SC Materials Science; Mechanics; Physics GA VR702 UT WOS:A1996VR70200022 ER PT J AU Safar, H Foltyn, SR Jia, QX Maley, MP AF Safar, H Foltyn, SR Jia, QX Maley, MP TI Bose glass vortex phase transition in twinned YBa2Cu3O7-delta superconductors SO PHILOSOPHICAL MAGAZINE B-PHYSICS OF CONDENSED MATTER STATISTICAL MECHANICS ELECTRONIC OPTICAL AND MAGNETIC PROPERTIES LA English DT Article ID SINGLE-CRYSTALS; COLUMNAR DEFECTS; THICK-FILMS; LOCALIZATION; DISORDER; FIELDS AB We show that twin boundaries, a ubiquitous c-axis-correlated (i.e., extending along the c axis throughout the thickness of the sample) crystallographic defect in some high-temperature superconductors, naturally induce a Bose glass vortex phase transition in the magnetic phase diagram of heavily twinned YBa2Cu3O7-delta thick films. C1 UNIV ILLINOIS,DEPT PHYS,CHICAGO,IL 60607. RP Safar, H (reprint author), LOS ALAMOS NATL LAB,SUPERCONDUCT TECHNOL CTR,POB 1663,LOS ALAMOS,NM 87545, USA. RI Jia, Q. X./C-5194-2008 NR 20 TC 16 Z9 16 U1 0 U2 0 PU TAYLOR & FRANCIS LTD PI LONDON PA ONE GUNDPOWDER SQUARE, LONDON, ENGLAND EC4A 3DE SN 0141-8637 J9 PHILOS MAG B JI Philos. Mag. B-Phys. Condens. Matter Stat. Mech. Electron. Opt. Magn. Prop. PD NOV PY 1996 VL 74 IS 5 BP 647 EP 654 DI 10.1080/01418639608240365 PG 8 WC Materials Science, Multidisciplinary; Mechanics; Physics, Applied; Physics, Condensed Matter SC Materials Science; Mechanics; Physics GA VR702 UT WOS:A1996VR70200023 ER PT J AU Schmiedeshoff, GM Smith, JL AF Schmiedeshoff, GM Smith, JL TI Supercritical behaviour of the mixed state of Nb-Ti in high magnetic fields SO PHILOSOPHICAL MAGAZINE B-PHYSICS OF CONDENSED MATTER STATISTICAL MECHANICS ELECTRONIC OPTICAL AND MAGNETIC PROPERTIES LA English DT Article ID SUPERCONDUCTORS; TEMPERATURE AB Measurements of the magnetic torque hysteresis in the mixed state of Nb-Ti are reported. The magnitude of the zero-field-cooled hysteresis in high magnetic fields persists in fixed fields to temperatures near the irreversibility line without significant decay. The data suggest that a supercritical state of the flux-line system is sustained in high magnetic fields. The compounds UBe13 and YBa2Cu3O7-delta show the same behaviour. C1 LOS ALAMOS NATL LAB,PULSE FACIL,NATL HIGH MAGNET FIELD LAB,LOS ALAMOS,NM 87545. RP Schmiedeshoff, GM (reprint author), OCCIDENTAL COLL,DEPT PHYS,LOS ANGELES,CA 90041, USA. NR 12 TC 1 Z9 1 U1 2 U2 2 PU TAYLOR & FRANCIS LTD PI LONDON PA ONE GUNDPOWDER SQUARE, LONDON, ENGLAND EC4A 3DE SN 0141-8637 J9 PHILOS MAG B JI Philos. Mag. B-Phys. Condens. Matter Stat. Mech. Electron. Opt. Magn. Prop. PD NOV PY 1996 VL 74 IS 5 BP 655 EP 661 DI 10.1080/01418639608240366 PG 7 WC Materials Science, Multidisciplinary; Mechanics; Physics, Applied; Physics, Condensed Matter SC Materials Science; Mechanics; Physics GA VR702 UT WOS:A1996VR70200024 ER PT J AU Correll, D AF Correll, D TI Many helping hands SO PHOTONICS SPECTRA LA English DT Letter RP Correll, D (reprint author), LAWRENCE LIVERMORE NATL LAB,LIVERMORE,CA 94550, USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU LAURIN PUBL CO INC PI PITTSFIELD PA BERKSHIRE COMMON PO BOX 1146, PITTSFIELD, MA 01202 SN 0731-1230 J9 PHOTON SPECTRA JI Photon. Spect. PD NOV PY 1996 VL 30 IS 11 BP 12 EP 12 PG 1 WC Optics SC Optics GA VU086 UT WOS:A1996VU08600004 ER PT J AU Vast, N Baroni, S Zerah, G Besson, JM Polian, A Grimsditch, M Chervin, JC AF Vast, N Baroni, S Zerah, G Besson, JM Polian, A Grimsditch, M Chervin, JC TI Lattice dynamics of alpha-boron from ab-initio calculation and Raman scattering under high pressure SO PHYSICA STATUS SOLIDI B-BASIC RESEARCH LA English DT Article; Proceedings Paper CT 7th International Conference on High Pressure Semiconductor Physics (HPSP-VII) CY JUL 28-31, 1996 CL SCHWABISCH GMUND, GERMANY SP Int Assoc Adv High Pressure Sci & Technol AB The Raman spectrum of icosahedral alpha-boron presents a very sharp peak at 525cm(-1) that was consistently rejected from the lattice modes but is still unexplained. New Raman scattering experiments under pressure are compared with ab-initio lattice dynamics calculations. The very good agreement of the mode frequencies and their pressure coefficients yields unambiguous assignment of all observed features, including the 525 cm(-1) line which is a highly harmonic librational mode of the icosahedron. This mode is also identified in the Raman spectrum of other icosahedral boron-rich solids. C1 ENS,CTR EUROPEAN CALCUL ATOM & MOL,F-69007 LYON,FRANCE. SCUOLA INT SUPER STUDI AVANZATI,I-34014 TRIESTE,ITALY. UNIV PARIS 06,CNRS,URA 782,F-75252 PARIS,FRANCE. ARGONNE NATL LAB,ARGONNE,IL 60439. RP Vast, N (reprint author), CEA,CTR ETUD LIMEIL VALENTON,F-94195 VILLENEUVE ST GEO,FRANCE. RI Baroni, Stefano/F-2982-2011; Polian, Alain/E-1555-2017 OI Baroni, Stefano/0000-0002-3508-6663; Polian, Alain/0000-0003-2261-9114 NR 11 TC 10 Z9 10 U1 0 U2 0 PU AKADEMIE VERLAG GMBH PI BERLIN PA MUHLENSTRASSE 33-34, D-13187 BERLIN, GERMANY SN 0370-1972 J9 PHYS STATUS SOLIDI B JI Phys. Status Solidi B-Basic Res. PD NOV PY 1996 VL 198 IS 1 BP 115 EP 119 DI 10.1002/pssb.2221980116 PG 5 WC Physics, Condensed Matter SC Physics GA VX573 UT WOS:A1996VX57300015 ER PT J AU Haller, EE Hsu, L Wolk, JA AF Haller, EE Hsu, L Wolk, JA TI Far infrared spectroscopy of semiconductors at large hydrostatic pressures SO PHYSICA STATUS SOLIDI B-BASIC RESEARCH LA English DT Article; Proceedings Paper CT 7th International Conference on High Pressure Semiconductor Physics (HPSP-VII) CY JUL 28-31, 1996 CL SCHWABISCH GMUND, GERMANY SP Int Assoc Adv High Pressure Sci & Technol ID III-V SEMICONDUCTORS; SI-DOPED GAAS; DX-CENTER; ALXGA1-XAS ALLOYS; DEFORMATION POTENTIALS; BAND; ABSORPTION; MODEL; DIAMOND; INP AB The combination of high resolution far infrared spectroscopy and large hydrostatic pressures produced by diamond anvil cells (DAC) offers a unique approach to the study of dopants, defects, and bandstructure related properties of semiconductors. The problem of small optical throughputs typical of DACs has been served. Using this unique tool, we have obtained several new results, including the discovery of a local vibrational mode of the DX center in GaAs:Si and the demonstration that the DX center is a negative-Cr defect. We have also discovered the first evidence of DX centers in InP and studied the ground to bound excited state transitions of shallow impurities in GaAs at pressures at which GaAs is an indirect bandgap semiconductor with its conduction band minimum near the X symmetry point. RP Haller, EE (reprint author), UNIV CALIF BERKELEY,LAWRENCE BERKELEY LAB,MAILSTOP 2-200,1 CYCLOTRON RD,BERKELEY,CA 94720, USA. NR 34 TC 2 Z9 2 U1 1 U2 3 PU AKADEMIE VERLAG GMBH PI BERLIN PA MUHLENSTRASSE 33-34, D-13187 BERLIN, GERMANY SN 0370-1972 J9 PHYS STATUS SOLIDI B JI Phys. Status Solidi B-Basic Res. PD NOV PY 1996 VL 198 IS 1 BP 153 EP 165 DI 10.1002/pssb.2221980122 PG 13 WC Physics, Condensed Matter SC Physics GA VX573 UT WOS:A1996VX57300021 ER PT J AU Wetzel, C Chen, AL Suski, T Ager, JW Walukiewicz, W AF Wetzel, C Chen, AL Suski, T Ager, JW Walukiewicz, W TI Si in GaN - On the nature of the background donor SO PHYSICA STATUS SOLIDI B-BASIC RESEARCH LA English DT Article; Proceedings Paper CT 7th International Conference on High Pressure Semiconductor Physics (HPSP-VII) CY JUL 28-31, 1996 CL SCHWABISCH GMUND, GERMANY SP Int Assoc Adv High Pressure Sci & Technol ID GALLIUM NITRIDE; RAMAN-SCATTERING; ENERGY AB A characterization of the Si impurity in GaN is performed by Raman spectroscopy. Applying hydrostatic pressure up to 25 GPa we study the behavior of the LO phonon-plasmon mode in a series of high mobility Si doped GaN films. In contrast to earlier results on unintentionally doped bulk GaN crystals no freeze out of the free carriers could be observed in Si doped samples. We find that Si is a shallow hydrogenic donor throughout the pressure range studied. This result positively excludes Si incorporation as a dominant source of free electrons in previously studied bulk GaN samples. RP Wetzel, C (reprint author), UNIV CALIF BERKELEY,LAWRENCE BERKELEY LAB,MAILSTOP 2-200,1 CYCLOTRON RD,BERKELEY,CA 94720, USA. RI Wetzel, Christian/O-4017-2014; OI Wetzel, Christian/0000-0002-6055-0990; Ager, Joel/0000-0001-9334-9751 NR 18 TC 10 Z9 10 U1 0 U2 2 PU AKADEMIE VERLAG GMBH PI BERLIN PA MUHLENSTRASSE 33-34, D-13187 BERLIN, GERMANY SN 0370-1972 J9 PHYS STATUS SOLIDI B JI Phys. Status Solidi B-Basic Res. PD NOV PY 1996 VL 198 IS 1 BP 243 EP 249 DI 10.1002/pssb.2221980132 PG 7 WC Physics, Condensed Matter SC Physics GA VX573 UT WOS:A1996VX57300031 ER PT J AU Choi, IH Yu, PY AF Choi, IH Yu, PY TI Pressure dependence of band gaps and deep centers in chalcopyrite semiconductors SO PHYSICA STATUS SOLIDI B-BASIC RESEARCH LA English DT Article; Proceedings Paper CT 7th International Conference on High Pressure Semiconductor Physics (HPSP-VII) CY JUL 28-31, 1996 CL SCHWABISCH GMUND, GERMANY SP Int Assoc Adv High Pressure Sci & Technol ID AGGAS2 AB We have determined the pressure coefficients of fundamental energy gap and deep centers in two chalcopyrite semiconductors AgGaS2 and CuGaS2 from their absorption and photoluminescence spectra. The pressure coefficient of a deep center in AgGaS2 is found to be larger than that of the band gap. A deep center with similar behavior has been reported already in AgGaSe2. We discuss the effect of p-d hybridization on these coefficients. C1 UNIV CALIF BERKELEY,DEPT PHYS,BERKELEY,CA 94720. UNIV CALIF BERKELEY,LAWRENCE BERKELEY LAB,DIV MAT SCI,BERKELEY,CA 94720. RP Choi, IH (reprint author), CHUNG ANG UNIV,DEPT PHYS,SEOUL 156756,SOUTH KOREA. NR 17 TC 7 Z9 7 U1 1 U2 2 PU AKADEMIE VERLAG GMBH PI BERLIN PA MUHLENSTRASSE 33-34, D-13187 BERLIN, GERMANY SN 0370-1972 J9 PHYS STATUS SOLIDI B JI Phys. Status Solidi B-Basic Res. PD NOV PY 1996 VL 198 IS 1 BP 251 EP 257 DI 10.1002/pssb.2221980133 PG 7 WC Physics, Condensed Matter SC Physics GA VX573 UT WOS:A1996VX57300032 ER PT J AU Besson, JM Bellaiche, L Kunc, K AF Besson, JM Bellaiche, L Kunc, K TI Second-order pretransitional effects in the high pressure phase transition of indium nitride SO PHYSICA STATUS SOLIDI B-BASIC RESEARCH LA English DT Article; Proceedings Paper CT 7th International Conference on High Pressure Semiconductor Physics (HPSP-VII) CY JUL 28-31, 1996 CL SCHWABISCH GMUND, GERMANY SP Int Assoc Adv High Pressure Sci & Technol AB Indium nitride, which has the hexagonal wurtzite structure, transforms to an NaCl lattice between 12 and 16 GPa. Prior to this transition nonlinearities occur in the wurtzite phase, particularly a steep decrease of the c/a axial ratio. The equation of state and nonlinear behavior of c, a, and c/a of InN under pressure have been calculated by using the first-principles total-energy pseudopotential method. The calculations fit with experiment up to the phase transition pressure (15 GPa), which validates their accuracy. Pursuing the calculations in the wurtzite structure above the actual transition pressure the nonlinearities appear to be caused by a virtual second-order isostructural phase transition between two wurtzite structures with unequal internal positional parameters. This second-order process is interrupted by the first-order reconstructive phase transition to the high pressure structure and remains observable only as its precursor. C1 NATL RENEWABLE ENERGY LAB,GOLDEN,CO 80401. UNIV PARIS 06,ASSOCIE CNRS,PHYS SOLIDES LAB,F-75252 PARIS 05,FRANCE. RP Besson, JM (reprint author), UNIV PARIS 06,URA 782,LAB ASSOCIE CNRS,4 PL JUSSIEU,F-75252 PARIS 05,FRANCE. RI Kunc, Karel/E-3453-2017 NR 14 TC 6 Z9 6 U1 1 U2 4 PU AKADEMIE VERLAG GMBH PI BERLIN PA MUHLENSTRASSE 33-34, D-13187 BERLIN, GERMANY SN 0370-1972 J9 PHYS STATUS SOLIDI B JI Phys. Status Solidi B-Basic Res. PD NOV PY 1996 VL 198 IS 1 BP 469 EP 474 DI 10.1002/pssb.2221980161 PG 6 WC Physics, Condensed Matter SC Physics GA VX573 UT WOS:A1996VX57300060 ER PT J AU Yu, LH AF Yu, LH TI Quantum tunneling in a dissipative system SO PHYSICAL REVIEW A LA English DT Article ID 2-STATE SYSTEM; DYNAMICS AB Applying a technique developed recently [L. H. Yu and C. P. Sun, Phys. Rev. A 49, 592 (1994); L. H. Yu, Phys. Lett. 202, 167 (1995)] for a harmonic oscillator coupled to a bath of harmonic oscillators, we present an exact solution for the tunneling problem in an Ohmic dissipative system with inverted harmonic potential. The result shows that while the dissipation tends to suppress the tunneling, the Brownian motion tends to enhance the tunneling. Whether the tunneling rate increases or not would then depend on the initial conditions. We give a specific formula to calculate the tunneling probability determined by various parameters and the initial conditions. RP Yu, LH (reprint author), BROOKHAVEN NATL LAB,NATL SYNCHROTRON LIGHT SOURCE DEPT,NEW YORK,NY 11973, USA. NR 10 TC 8 Z9 8 U1 1 U2 2 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 1050-2947 J9 PHYS REV A JI Phys. Rev. A PD NOV PY 1996 VL 54 IS 5 BP 3779 EP 3782 DI 10.1103/PhysRevA.54.3779 PG 4 WC Optics; Physics, Atomic, Molecular & Chemical SC Optics; Physics GA VT673 UT WOS:A1996VT67300016 ER PT J AU Dunford, RW AF Dunford, RW TI Parity nonconservation in high-Z heliumlike ions SO PHYSICAL REVIEW A LA English DT Article ID ELECTROWEAK THEORY; NUCLEAR-STRUCTURE; MUONIC ATOMS; VIOLATION; U-90+; URANIUM; CESIUM; DECAY; RATES AB Detection of parity-violating asymmetries in 1s(1/2)2p(1/2)(3)P(0)-1s(21)S(0) two-photon transitions in high-Z He-like ions is discussed. The circular polarization asymmetry of one of the two photons emitted in the two-photon decay of the 2(3)P(0) level in He-like uranium is of order 3 x 10(-4). parity-violating asymmetries in the laser-driven processes of singly stimulated two-photon emission and anti-Stokes Raman scattering are also discussed. Further experimental and theoretical research is needed to determine if parity experiments based on these processes are feasible. RP Dunford, RW (reprint author), ARGONNE NATL LAB,DIV PHYS,ARGONNE,IL 60439, USA. NR 24 TC 36 Z9 36 U1 0 U2 1 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 1050-2947 J9 PHYS REV A JI Phys. Rev. A PD NOV PY 1996 VL 54 IS 5 BP 3820 EP 3823 DI 10.1103/PhysRevA.54.3820 PG 4 WC Optics; Physics, Atomic, Molecular & Chemical SC Optics; Physics GA VT673 UT WOS:A1996VT67300023 ER PT J AU DePristo, AE AF DePristo, AE TI Hohenberg-Kohn density-functional theory as an implicit Poisson equation for density changes from summed fragment densities SO PHYSICAL REVIEW A LA English DT Article ID ELECTRON-GAS; MOLECULAR-DYNAMICS; TIGHT-BINDING; POTENTIALS; ENERGY; ATOMS; APPROXIMATION AB An implicit Poisson equation is derived for the change in density Delta n(r) from summed atomic or atomiclike densities within the Hohenberg-Kohn formulation of density-functional theory. Iterative and perturbation solutions are detailed. The first-order perturbation and first iterative solutions are equivalent, yielding Delta n(r)=(4 pi)(-1 del 2)[(delta G/delta n)(system)-(delta G/delta n)(atoms)], where the kinetic-exchange-correlation potential of the full system and the summed isolated atoms are (delta G/delta n)(system) and (delta G/delta n)(atoms), respectively. G is the integrand of the kinetic-exchange-correlation energy. The second-order perturbation solution leads to a Fredholm equation relating (1) the second functional derivative, (delta(2)G/delta n(2))(system), with summed atomic densities; (2) the induced electrostatic energy; and, (3) the difference between (delta G/delta n)(system) and (delta G/delta n)(atoms). Numerical examples are shown for the Ni, O, and Na atoms embedded in jellium. C1 IOWA STATE UNIV, AMES LAB, AMES, IA 50011 USA. RP DePristo, AE (reprint author), IOWA STATE UNIV, DEPT CHEM, AMES, IA 50011 USA. NR 32 TC 3 Z9 3 U1 1 U2 1 PU AMER PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 1050-2947 EI 1094-1622 J9 PHYS REV A JI Phys. Rev. A PD NOV PY 1996 VL 54 IS 5 BP 3863 EP 3869 DI 10.1103/PhysRevA.54.3863 PG 7 WC Optics; Physics, Atomic, Molecular & Chemical SC Optics; Physics GA VT673 UT WOS:A1996VT67300027 ER PT J AU Fournier, KB Cohen, M Goldstein, WH Osterheld, AL Finkenthal, M May, MJ Terry, JL Graf, MA Rice, J AF Fournier, KB Cohen, M Goldstein, WH Osterheld, AL Finkenthal, M May, MJ Terry, JL Graf, MA Rice, J TI Dielectronic recombination and excitation autoionization rate coefficients for potassiumlike Mo23+ to fluorinelike Mo33+ SO PHYSICAL REVIEW A LA English DT Article ID ELECTRON-IMPACT IONIZATION; DISTORTED-WAVE CALCULATIONS; INNER-SHELL EXCITATIONS; ISOELECTRONIC SEQUENCE; RESONANT EXCITATION; MAGNESIUM SEQUENCE; CORONAL PLASMAS; COMPLEX SPECTRA; FUSION PLASMAS; I-LIKE AB Fully relativistic, ab initio calculations of the rate of dielectronic recombination (DR) have been performed for fluorinelike Mo33+ to magnesiumlike Mo30+ and chlorinelike Mo25+ and argonlike Mo24+. Calculations of the rate of excitation autoionization (EA) have been performed for neonlike Mo32+ to aluminumlike Mo29+ and argonlike Mo24+ and potassiumlike Mo23+. The detailed calculations of the atomic structure and rate coefficients for charge states in these groups allow interpolation of the DR and EA rates for the more complex ions having 3s(2)3p(k) (k=1-4 for DR and k=2-5 for EA) ground states. The calculations for DR are broken up by different classes of excitation channels; simple, analytic formulas are then fit to the calculations. The effects of configuration interaction on the rates of DR and EA have been studied in detail and are found to have a slight effect on only a small class of the Auger rates needed for the present work. Radiative transitions between energy levels in the continuum are investigated and found to have a moderate effect on the DR rates and a small effect on the EA rates of the ions in this paper. C1 JOHNS HOPKINS UNIV,DEPT PHYS & ASTRON,BALTIMORE,MD 21218. MIT,CTR PLASMA FUS,CAMBRIDGE,MA 02139. HEBREW UNIV JERUSALEM,RACAH INST PHYS,IL-91904 JERUSALEM,ISRAEL. RP Fournier, KB (reprint author), LAWRENCE LIVERMORE NATL LAB,LIVERMORE,CA 94551, USA. NR 44 TC 19 Z9 19 U1 1 U2 3 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 1050-2947 J9 PHYS REV A JI Phys. Rev. A PD NOV PY 1996 VL 54 IS 5 BP 3870 EP 3884 DI 10.1103/PhysRevA.54.3870 PG 15 WC Optics; Physics, Atomic, Molecular & Chemical SC Optics; Physics GA VT673 UT WOS:A1996VT67300028 ER PT J AU Osterheld, AL Magunov, AI Dyakin, VM Faenov, AY Pikuz, TA Skobelev, IY Pisarczyk, T Parys, P Wolowski, J Makowski, J Pikuz, SA Romanova, VM Shelkovenko, TA AF Osterheld, AL Magunov, AI Dyakin, VM Faenov, AY Pikuz, TA Skobelev, IY Pisarczyk, T Parys, P Wolowski, J Makowski, J Pikuz, SA Romanova, VM Shelkovenko, TA TI Measurements of the ground-state ionization energy and wavelengths for the 1s(21)S(0)-1snp(1)P(1) (n=6-12) lines of Al XII SO PHYSICAL REVIEW A LA English DT Article ID HELIUM-LIKE IONS; LAMB-SHIFT CALCULATIONS; ISOELECTRONIC SEQUENCE; PRECISION-MEASUREMENT; PLASMA MICROSOURCES; SPECTROSCOPY; TRANSITIONS; HYDROGENLIKE; URANIUM; SPECTRA AB The wavelengths of the 1s(2) S-1(0)-1snp P-1(1) (n=6-12) transitions in He-like Al XII have been measured in laser-produced and X pinch plasmas. The accuracy of the present measurements (0.3-0.5 m Angstrom) is a severalfold improvement over previous results. In addition, the resonance transitions from the 11 P-1(1) and 12 P-1(1) levels of He-like Al XII are observed. Finally, the Rydberg series is used to determine the ground-state ionization energy of Al XII, with a precision of 50 parts per million. This method gives E(ion)=2085.98+/-0.10 eV. These experimental results are compared with theoretical data calculated by several different methods. C1 VNIIFTRI,MULTICHARGED IONS SPECTRA DATA CTR,MENDELEYEVSK 141570,MOSCOW REG,RUSSIA. INST PLASMA PHYS & LASER MICROFUS,WARSAW,POLAND. RUSSIAN ACAD SCI,PN LEBEDEV PHYS INST,MOSCOW,RUSSIA. RP Osterheld, AL (reprint author), LAWRENCE LIVERMORE NATL LAB,LIVERMORE,CA 94551, USA. RI Romanova, Vera/M-6922-2015; Pikuz, Sergey/M-8231-2015; Shelkovenko, Tatiana/M-8254-2015 NR 41 TC 10 Z9 10 U1 0 U2 1 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 1050-2947 J9 PHYS REV A JI Phys. Rev. A PD NOV PY 1996 VL 54 IS 5 BP 3971 EP 3976 DI 10.1103/PhysRevA.54.3971 PG 6 WC Optics; Physics, Atomic, Molecular & Chemical SC Optics; Physics GA VT673 UT WOS:A1996VT67300038 ER PT J AU Moudry, BW Yenen, O Jaecks, DH Macek, JH AF Moudry, BW Yenen, O Jaecks, DH Macek, JH TI Experimental determination of orbital and spin orientation of (Ar+)* formed in collisions SO PHYSICAL REVIEW A LA English DT Article AB We have experimentally obtained the state multipoles up to rank two for J-resolved (7/2,5/2) states of Ar+ for the two-electron process He++Ar-->He(1s(2)) + Ar+(3p(4)[D-1]4p F-2(7/2,5/2)0) by measuring the Stokes parameters of the fluorescence light from (Ar+)* in coincidence with the scattered He. By expanding the state multipoles of each J state in terms of total orbital and total spin multipole moments, we have determined the contributions to the experimentally determined state multipoles of each J state due to total orbital and total spin angular momenta. When the process is spin dependent, it is possible to extract magnetic octupole moments of the excited state due to the orbital charge circulation. C1 UNIV NEBRASKA,BEHLEN LAB PHYS,LINCOLN,NE 68588. UNIV TENNESSEE,DEPT PHYS & ASTRON,KNOXVILLE,TN 37996. OAK RIDGE NATL LAB,OAK RIDGE,TN 37831. NR 12 TC 3 Z9 3 U1 0 U2 0 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 1050-2947 J9 PHYS REV A JI Phys. Rev. A PD NOV PY 1996 VL 54 IS 5 BP 4119 EP 4126 DI 10.1103/PhysRevA.54.4119 PG 8 WC Optics; Physics, Atomic, Molecular & Chemical SC Optics; Physics GA VT673 UT WOS:A1996VT67300054 ER PT J AU Briand, JP Giardino, G Borsoni, G Froment, M Eddrief, M Sebenne, C Bardin, S Schneider, D Jin, J Khemliche, H Xie, Z Prior, M AF Briand, JP Giardino, G Borsoni, G Froment, M Eddrief, M Sebenne, C Bardin, S Schneider, D Jin, J Khemliche, H Xie, Z Prior, M TI Decay of hollow atoms above and below a surface SO PHYSICAL REVIEW A LA English DT Article ID HIGHLY CHARGED IONS; AUGER; EMISSION; SLOW AB We present some experiments which demonstrate definitively that the filling of the L shell of argon hollow atoms formed below a surface proceeds, like those formed above a surface, through a cascade of eight spontaneous transitions. This result means that the hollow atoms' clock property may be used in both cases to study continuously the approach and penetration of an ion onto a surface as it is experimentally shown. C1 UNIV PARIS 06,CNRS,UPR 0015,LAB LIQUIDES & ELECTROCHIM,F-75252 PARIS 05,FRANCE. UNIV PARIS 06,CNRS,ERS 113,PHYS SOLIDES LAB,F-75252 PARIS 05,FRANCE. LAWRENCE LIVERMORE NATL LAB,LIVERMORE,CA 94550. UNIV CALIF BERKELEY,LAWRENCE BERKELEY LAB,BERKELEY,CA 94720. RP Briand, JP (reprint author), UNIV PARIS 06,CNRS,ERS 112,LAB PHYS ATOM & NUCL,4 PL JUSSIEU,F-75252 PARIS 05,FRANCE. NR 21 TC 45 Z9 46 U1 0 U2 2 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 1050-2947 J9 PHYS REV A JI Phys. Rev. A PD NOV PY 1996 VL 54 IS 5 BP 4136 EP 4139 DI 10.1103/PhysRevA.54.4136 PG 4 WC Optics; Physics, Atomic, Molecular & Chemical SC Optics; Physics GA VT673 UT WOS:A1996VT67300056 ER PT J AU Burgdorfer, J Yamazaki, Y AF Burgdorfer, J Yamazaki, Y TI Above-surface potential sputtering of protons by highly charged ions SO PHYSICAL REVIEW A LA English DT Article ID ELECTRON-STIMULATED DESORPTION; SLOW MULTICHARGED IONS; LITHIUM-FLUORIDE; LIF(100) SURFACE; EMISSION; ATOMS; ACCELERATION; COLLISIONS; NEUTRALIZATION; BOMBARDMENT AB We present a description for potential-energy-induced sputtering of protons by slow, highly charged ions in front of insulator surfaces, based on the classical over-barrier model. Proton emission results from the localized Coulomb explosion after breaking the covalent C-H bond in hydrocarbons at the surface. The model describes the very steep dependence on the projectile charge (similar to Q(4)-Q(6)) for moderately high charge states (Q less than or similar to 10), in agreement with the experiment. It furthermore predicts the saturation of the Q dependence for even higher charge states. C1 UNIV TENNESSEE,DEPT PHYS,KNOXVILLE,TN 37996. OAK RIDGE NATL LAB,OAK RIDGE,TN 37831. RP Burgdorfer, J (reprint author), UNIV TOKYO,INST PHYS,KOMABA,TOKYO 153,JAPAN. RI Yamazaki, Yasunori/N-8018-2015 OI Yamazaki, Yasunori/0000-0001-5712-0853 NR 31 TC 37 Z9 37 U1 1 U2 3 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 1050-2947 J9 PHYS REV A JI Phys. Rev. A PD NOV PY 1996 VL 54 IS 5 BP 4140 EP 4144 DI 10.1103/PhysRevA.54.4140 PG 5 WC Optics; Physics, Atomic, Molecular & Chemical SC Optics; Physics GA VT673 UT WOS:A1996VT67300057 ER PT J AU Lebius, H Minniti, R Lim, JY Elston, SB AF Lebius, H Minniti, R Lim, JY Elston, SB TI Charge-state dependence of image-charge acceleration of convoy electrons in fast, grazing collisions of carbon ions with a silicon(100) surface SO PHYSICAL REVIEW A LA English DT Article ID ABOVE-SURFACE; HOLLOW ATOMS; EMISSION; SLOW; SCATTERING; CONTINUUM; CAPTURE AB Electron emission distributions, triply differential in emission energy and angles, are presented for collisions. of singly through quadruply charged C ions impinging on a Si(100) surface, with ion energies between 3.6 and 6.0 MeV and grazing angles of incidence between 0.1 degrees and 1.0 degrees, respectively. The electron emission spectra measured under these conditions confirm previous reports of a shift of the convoy electron peak toward higher energy due to surface wake or image acceleration. Detailed angular distributions demonstrate a shift of convoy emission towards larger angles with respect to the surface plane, which is further evidence of the acceleration of emitted electrons by the surface wake potential. In addition, we observe the peak energy shift to depend upon the incident ion charge state for the higher projectile velocity (similar to 4.5 a.u.). This dependence may be understood as a consequence of incomplete projectile charge equilibration at the time of convoy electron production. The charge-state dependence is not observed at the lower collision velocity (similar to 3.5 a.u.). C1 UNIV TENNESSEE,KNOXVILLE,TN 37996. OAK RIDGE NATL LAB,OAK RIDGE,TN 37831. RP Lebius, H (reprint author), UNIV STOCKHOLM,STOCKHOLM,SWEDEN. NR 25 TC 4 Z9 4 U1 0 U2 0 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 1050-2947 J9 PHYS REV A JI Phys. Rev. A PD NOV PY 1996 VL 54 IS 5 BP 4171 EP 4177 DI 10.1103/PhysRevA.54.4171 PG 7 WC Optics; Physics, Atomic, Molecular & Chemical SC Optics; Physics GA VT673 UT WOS:A1996VT67300061 ER PT J AU Deng, L Garrett, WR Payne, MG Lee, DZ AF Deng, L Garrett, WR Payne, MG Lee, DZ TI Effect of the odd-photon destructive interference on laser-induced transparency and multiphoton excitation and ionization in rubidium SO PHYSICAL REVIEW A LA English DT Article ID ELECTROMAGNETICALLY-INDUCED TRANSPARENCY; DEPENDENT QUANTUM INTERFERENCE; NONLINEAR-OPTICAL-GENERATION; PUMPED STIMULATED EMISSIONS; 4-PHOTON RESONANCE; COOPERATIVE SHIFTS; ATOMIC-HYDROGEN; INVERSION; SUPPRESSION; STATES AB We report experimental results on two-color multiphoton ionization and four-wave-mixing production under conditions where one form of laser-induced transparency (LIT) occurs. Under the conditions of LIT, multiphoton-ionization line shapes obtained by tuning one laser through a two-photon resonance exhibit a pronounced Autler-Townes splitting at low concentrations, when a second laser couples the two-photon state to a third level. In this concentration region we observed a four-wave-mixing held that increased quadratically with concentration. As the concentration is increased the Autler-Townes splitting starts to decrease, and disappears completely as a critical concentration is reached. simultaneously, the four-wave-mixing field intensity starts to level off and finally becomes concentration independent. These observations are explained in terms of odd-photon destructive interference between different excitation pathways. In rubidium, we demonstrate that above concentrations of n similar or equal to 5 X 10(14) cm(-3) the four-wave-mixing field is concentration independent and the multiphoton-ionization line shape shows no Autler-Townes splitting, and the width of the line shape is determined by the laser bandwidth. The results presented here demonstrate that destructive interference significantly limits the high-efficiency and high-intensity nonlinear optical generation promised in early studies on LIT, at least for the multimode laser system used in the present experiment. C1 UNIV BRITISH COLUMBIA, DEPT PHYS, VANCOUVER, BC, CANADA. GEORGIA SO UNIV, DEPT PHYS, STATESBORO, GA 30460 USA. RP OAK RIDGE NATL LAB, CHEM PHYS SECT, OAK RIDGE, TN 37831 USA. RI Deng, Lu/B-3997-2012 NR 34 TC 5 Z9 5 U1 0 U2 2 PU AMER PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 2469-9926 EI 2469-9934 J9 PHYS REV A JI Phys. Rev. A PD NOV PY 1996 VL 54 IS 5 BP 4218 EP 4225 DI 10.1103/PhysRevA.54.4218 PG 8 WC Optics; Physics, Atomic, Molecular & Chemical SC Optics; Physics GA VT673 UT WOS:A1996VT67300066 ER PT J AU VanSiclen, CD AF VanSiclen, CD TI Random nucleation and growth kinetics SO PHYSICAL REVIEW B LA English DT Article ID CRYSTALLIZATION KINETICS; RECRYSTALLIZATION; IMPINGEMENT; METALS AB The classical Kolmogorov-Johnson-Mehl-Avrami (KJMA) equation for nucleation and growth transformation which assumes random nucleation and cessation of growth where grains impinge, was originally derived by accounting for the ''extended volume'' that is obtained when overlap of the growing grains is (mathematically) permitted. Motivated by experimental and computational results that call into question the validity of this equation and by recent theoretical concerns about the appropriate content of the extended volume, a derivation of the KJMA equation is presented that does not rely on the concept of the ''extended volume.'' RP VanSiclen, CD (reprint author), IDAHO NATL ENGN LAB,IDAHO FALLS,ID 83415, USA. NR 22 TC 38 Z9 38 U1 0 U2 9 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 0163-1829 J9 PHYS REV B JI Phys. Rev. B PD NOV 1 PY 1996 VL 54 IS 17 BP 11845 EP 11848 DI 10.1103/PhysRevB.54.11845 PG 4 WC Physics, Condensed Matter SC Physics GA VT681 UT WOS:A1996VT68100001 ER PT J AU Radhakrishna, P Cable, JW AF Radhakrishna, P Cable, JW TI Inelastic-neutron-scattering studies of spin-wave excitations in the pnictides MnSb and CrSb SO PHYSICAL REVIEW B LA English DT Article AB The spin-wave dispersion relations in the ferromagnet MnSb, and the antiferromagnet CrSb, have been measured, by neutron inelastic scattering, along high-symmetry directions in reciprocal space, as a function of temperature. The effect of composition is discussed. The dispersion in CrSb is found to rise very steeply as a function of q, and a gap in the excitation spectrum occurs at q=0. The results for these itinerant electron magnetic materials are compared with previous experimental and theoretical work. C1 OAK RIDGE NATL LAB,DIV SOLID STATE,OAK RIDGE,TN 37831. RP Radhakrishna, P (reprint author), INDIAN INST SCI,DEPT PHYS,BANGALORE 12,KARNATAKA,INDIA. NR 10 TC 27 Z9 27 U1 2 U2 11 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 0163-1829 J9 PHYS REV B JI Phys. Rev. B PD NOV 1 PY 1996 VL 54 IS 17 BP 11940 EP 11943 DI 10.1103/PhysRevB.54.11940 PG 4 WC Physics, Condensed Matter SC Physics GA VT681 UT WOS:A1996VT68100026 ER PT J AU Zuo, F Schlueter, JA Kelly, ME Williams, JM AF Zuo, F Schlueter, JA Kelly, ME Williams, JM TI Mixed-state magnetoresistance in organic superconductors kappa-(BEDT-TTF)(2)Cu(NCS)(2) SO PHYSICAL REVIEW B LA English DT Article ID MAGNETIC PENETRATION DEPTH; CRITICAL-FIELD; KAPPA-(BEDT-TTF)2CUBR; (BEDT-TTF)2CU(NCS)2; TRANSITION; BEHAVIOR AB We report transport measurements with field and current parallel to the a axis (perpendicular to the conducting plane) in the organic superconductor kappa-(BEDT-TTF)(2)Cu(NCS)(2). The magnetoresistance displays a peak effect as a function of field and temperature with the peak fields increasing linearly with decreasing temperatures. The peak resistance is found to be greater than the normal-state value extrapolated from both high- and low-field measurements. The results are in sharp contrast to the conventional dissipation mechanisms in the mixed state for anisotropic superconductors, as in the case of Bi2Sr2CaCu2O8. We propose a phenomenological model that the peak in the magnetoresistance is caused by a scattering mechanism due to a strong coupling to the underlying crystal lattice of fluctuating vortices (vortex polarons). The model can semiquantitatively fit the data. C1 ARGONNE NATL LAB,DIV CHEM,ARGONNE,IL 60439. ARGONNE NATL LAB,DIV SCI MAT,ARGONNE,IL 60439. RP Zuo, F (reprint author), UNIV MIAMI,DEPT PHYS,CORAL GABLES,FL 33124, USA. NR 25 TC 22 Z9 22 U1 0 U2 0 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 0163-1829 J9 PHYS REV B JI Phys. Rev. B PD NOV 1 PY 1996 VL 54 IS 17 BP 11973 EP 11976 DI 10.1103/PhysRevB.54.11973 PG 4 WC Physics, Condensed Matter SC Physics GA VT681 UT WOS:A1996VT68100035 ER PT J AU Abrikosov, AA AF Abrikosov, AA TI Nature of the pseudogap in the optical conductivity of oxygen-deficient YBa2Cu3Ox SO PHYSICAL REVIEW B LA English DT Article ID C-AXIS RESPONSE; SINGLE-CRYSTALS; SUPERCONDUCTORS; TRANSPORT; STATE AB The pseudogap in the c-axis optical conductivity of oxygen-deficient YBa2Cu3Ox is explained on the basis of the resonant tunneling through the barrier between the CuO2 planes with the use of localized centers formed on place of the CuO chains. The conductivity as a function of frequency has a maximum, and its location and magnitude depend only on the spectrum of resonant levels, and hence do not depend on temperature. In the case of a fully oxygenated substance the chains are complete, and no resonance centers are formed. These features were observed in experiment. Comparison is done with existing data. Other possible mechanisms of the pseudogap formation are briefly discussed. RP Abrikosov, AA (reprint author), ARGONNE NATL LAB,DIV MAT SCI,9700 S CASS AVE,ARGONNE,IL 60439, USA. NR 20 TC 11 Z9 11 U1 1 U2 1 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 0163-1829 J9 PHYS REV B JI Phys. Rev. B PD NOV 1 PY 1996 VL 54 IS 17 BP 12003 EP 12005 DI 10.1103/PhysRevB.54.12003 PG 3 WC Physics, Condensed Matter SC Physics GA VT681 UT WOS:A1996VT68100043 ER PT J AU Sarrao, JL Young, DP Fisk, Z Moshopoulou, EG Thompson, JD Chakoumakos, BC Nagler, SE AF Sarrao, JL Young, DP Fisk, Z Moshopoulou, EG Thompson, JD Chakoumakos, BC Nagler, SE TI Structural, magnetic, and transport properties of La2Cu1-xLixO4 SO PHYSICAL REVIEW B LA English DT Article ID SUPERCONDUCTIVITY; LA2-XSRXCUO4; SYSTEM AB Li substitutes for Cu in La2CuO4 up to the limiting stoichiometry La2Cu0.5Li0.5O4, which has superstructure order. The effects of this in-plane hole doping on the structural and magnetic properties of La2CuO4 are very similar to those due to Sr substitution. The tetragonal-orthorhombic structural phase transition occurs, for a given amount of Sr or Li, at nearly the same temperature, and the in-plane lattice constant of La2-ySryCu1-xLixO4 at room temperature depends only on the combined hole count (x+y) and not on the individual Sr or Li concentration. Long-range magnetic order is destroyed upon substituting 3% Li for Cu, analogous to the effect of Sr substitution on T-Neel. However, the holes introduced by Li substitution are bound. The resistivity as a function of temperature is nonmetallic for all Li concentrations. C1 LOS ALAMOS NATL LAB, DIV MAT SCI & TECHNOL, LOS ALAMOS, NM 87545 USA. OAK RIDGE NATL LAB, DIV SOLID STATE, OAK RIDGE, TN 37831 USA. RP FLORIDA STATE UNIV, NATL HIGH MAGNET FIELD LAB, TALLAHASSEE, FL 32306 USA. RI Nagler, Stephen/B-9403-2010; Nagler, Stephen/E-4908-2010; Chakoumakos, Bryan/A-5601-2016 OI Nagler, Stephen/0000-0002-7234-2339; Chakoumakos, Bryan/0000-0002-7870-6543 NR 22 TC 45 Z9 46 U1 0 U2 5 PU AMER PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 2469-9950 EI 2469-9969 J9 PHYS REV B JI Phys. Rev. B PD NOV 1 PY 1996 VL 54 IS 17 BP 12014 EP 12017 DI 10.1103/PhysRevB.54.12014 PG 4 WC Physics, Condensed Matter SC Physics GA VT681 UT WOS:A1996VT68100046 ER PT J AU Miyano, KE Ma, Y Southworth, SH Cowan, PL Karlin, BA AF Miyano, KE Ma, Y Southworth, SH Cowan, PL Karlin, BA TI Resonant Raman scattering in potassium and chlorine K-beta x-ray emission from KCl SO PHYSICAL REVIEW B LA English DT Article ID SHELL HOLE WIDTHS; SYNCHROTRON RADIATION; FLUORESCENCE; EDGE; EXCITATION; EVOLUTION; SPECTRA; HALIDES; XENON; ATOMS AB We have measured the potassium K-beta and chlorine K-beta resonant Raman x-ray scattering from KCl. Strong K-shell absorption peaks are directly reflected in the resonant Raman spectra. The emission spectra are qualitatively evaluated in terms of the associated absorption spectra, based on a simple single-electron model of the scattering process. This model affords direct interpretation of the energy, line shape, and intensity variations of the emission spectra. In the resonant Raman regime, energy offsets between the data and the model predictions are attributed to binding energy differences between intermediate and final state excitons; thus these offsets indicate that the associated peaks in the absorption spectra are excitonic in nature. C1 PACIFIC NW LAB, RICHLAND, WA 99352 USA. UNIV WASHINGTON, DEPT PHYS, SEATTLE, WA 98195 USA. BROOKHAVEN NATL LAB, UPTON, NY 11973 USA. RP Miyano, KE (reprint author), CUNY BROOKLYN COLL, DEPT PHYS, BROOKLYN, NY 11210 USA. NR 39 TC 4 Z9 4 U1 0 U2 2 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 0163-1829 J9 PHYS REV B JI Phys. Rev. B PD NOV 1 PY 1996 VL 54 IS 17 BP 12022 EP 12028 DI 10.1103/PhysRevB.54.12022 PG 7 WC Physics, Condensed Matter SC Physics GA VT681 UT WOS:A1996VT68100048 ER PT J AU Nakotte, H Prokes, K Bruck, E Buschow, KHJ deBoer, FR Andreev, AV Aronson, MC Lacerda, A Torikachvili, MS Robinson, RA Bourke, MAM Schultz, AJ AF Nakotte, H Prokes, K Bruck, E Buschow, KHJ deBoer, FR Andreev, AV Aronson, MC Lacerda, A Torikachvili, MS Robinson, RA Bourke, MAM Schultz, AJ TI Non-Fermi-liquid scaling in heavy-fermion UCu3.5Al1.5 and UCu3Al2 SO PHYSICAL REVIEW B LA English DT Article ID BEHAVIOR; UCU5-XPDX; ALLOY AB We report on specific-heat, magnetic-susceptibility, high-field-magnetization, electrical-resistivity, and neutron-diffraction results on UCu3.5Al1.5 (polycrystal) and UCu3Al2, (polycrystal and single crystal). Our results indicate that both compounds crystallize in the hexagonal CaCu5 structure with ordered UCu2 planes separated by planes containing a statistical distribution of Al along with the remaining Cu atoms. At low temperatures, the specific heat and the magnetic susceptibility of both compounds are enhanced, but their temperature dependences are found to be distinct from expectations of Fermi-liquid theory. UCU3.5Al1.5 does not order magnetically, and the low-temperature specific heat and magnetic susceptibility show scaling behavior (C/T proportional to ln T and chi proportional to T--1/3) reminiscent of non-Fermi-liquid materials. For UCu3Al2, on the other hand, the low-temperature scaling of bulk properties is masked by an anomaly around 8-10 K, which is presumably of magnetic origin. Single-crystal studies of UCu3Al2 reveal a huge magnetic anisotropy with very different in-plane response compared to the c-axis response. Our data provide evidence that any temperature dependence of the magnetic susceptibility (and electrical resistivity) of polycrystalline material may be due to averaging anisotropic response over all crystallographic directions. The results are discussed in the context of findings from other non-Fermi-liquid materials. C1 UNIV AMSTERDAM,VANDER WAALS ZEEMAN INST,NL-1018 XE AMSTERDAM,NETHERLANDS. ACAD SCI CZECH REPUBL,INST PHYS,CR-18040 PRAGUE 8,CZECH REPUBLIC. UNIV MICHIGAN,HARRISON M RANDALL LAB PHYS,ANN ARBOR,MI 48109. LOS ALAMOS NATL LAB,PULSED FIELD FACIL,NATL HIGH MAGNET FIELD LAB,LOS ALAMOS,NM 87545. SAN DIEGO STATE UNIV,DEPT PHYS,SAN DIEGO,CA 92182. ARGONNE NATL LAB,ARGONNE,IL 60439. RP Nakotte, H (reprint author), LOS ALAMOS NATL LAB,MANUEL LUJAN JR NEUTRON SCATTERING CTR,LOS ALAMOS,NM 87545, USA. RI Andreev, Alexander/B-6057-2011; Bruck, Ekkes/E-3365-2014 NR 27 TC 14 Z9 14 U1 0 U2 1 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 0163-1829 J9 PHYS REV B JI Phys. Rev. B PD NOV 1 PY 1996 VL 54 IS 17 BP 12176 EP 12183 DI 10.1103/PhysRevB.54.12176 PG 8 WC Physics, Condensed Matter SC Physics GA VT681 UT WOS:A1996VT68100067 ER PT J AU Matsuda, M Katsumata, K Eisaki, H Motoyama, N Uchida, S Shapiro, SM Shirane, G AF Matsuda, M Katsumata, K Eisaki, H Motoyama, N Uchida, S Shapiro, SM Shirane, G TI Magnetic excitations from the singlet ground state in the S=1/2 quasi-one-dimensional system Sr14-xYxCu24O41 SO PHYSICAL REVIEW B LA English DT Article ID SPIN-1/2 HEISENBERG-ANTIFERROMAGNET; COMPETING INTERACTIONS; SR14CU24O41; CUGEO3; CHAIN AB Inelastic neutron scattering measurements have been performed on the S=1/2 quasi-one-dimensional system Sr14-xYxCu24O41, which has both simple chains and two-leg ladders of copper ions. Strong magnetic inelastic peaks, which originate from the simple chains, have been observed at 9-14 meV in Sr14CU24O41. These spin gaps have been confirmed to originate from a dimerized state of the chain. The dimers are formed between spins which are separated by 2 and 4 times the distance between the nearest-neighbor copper ions in the simple chain. In addition, a weaker magnetic inelastic peak around 11 meV, which originates from a dimerized state in the ladder, has also been observed. These dimers are formed between the nearest-neighbor copper ions which are connected by the interladder coupling. We have also studied the effect of Y3+ substitution for Sr2+ Site on the dimerized states. It was found that the yttrium substitution suppresses the gap energies drastically. Possible origins of the dimerized ground state and the excitations are discussed. C1 UNIV TOKYO,BUNKYO KU,TOKYO 113,JAPAN. BROOKHAVEN NATL LAB,DEPT PHYS,UPTON,NY 11973. RP Matsuda, M (reprint author), RIKEN,INST PHYS & CHEM RES,WAKO,SAITAMA 35101,JAPAN. RI Matsuda, Masaaki/A-6902-2016 OI Matsuda, Masaaki/0000-0003-2209-9526 NR 21 TC 89 Z9 90 U1 0 U2 3 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 0163-1829 J9 PHYS REV B JI Phys. Rev. B PD NOV 1 PY 1996 VL 54 IS 17 BP 12199 EP 12206 DI 10.1103/PhysRevB.54.12199 PG 8 WC Physics, Condensed Matter SC Physics GA VT681 UT WOS:A1996VT68100070 ER PT J AU Sarrao, JL Immer, CD Benton, CL Fisk, Z Lawrence, JM Mandrus, D Thompson, JD AF Sarrao, JL Immer, CD Benton, CL Fisk, Z Lawrence, JM Mandrus, D Thompson, JD TI Evolution from first-order valence transition to heavy-fermion behavior in YbIn1-xAgxCu4 SO PHYSICAL REVIEW B LA English DT Article ID ALPHA-GAMMA-TRANSITION; KONDO VOLUME-COLLAPSE; PHASE-TRANSITION; YBXIN1-XCU2; DEPENDENCE; YBINCU4; YBAGCU4; CERIUM; ALLOYS; MODEL AB YbInCu4 undergoes a first-order isostructural valence transition near 40 K, whereas YbAgCu4 is a moderately heavy (gamma=250 mJ/mol K-2) mixed-valence compound. We have succeeded in growing single crystals of these compounds, as well as many intermediate alloys, using flux-growth techniques. The evolution from YbInCu4 to YbAgCu4 has been characterized using electrical resistivity, magnetic susceptibility, and x-ray powder diffraction. The data are interpreted in terms of the evolution of the single-impurity Kondo temperature as a function of Ag concentration. C1 UNIV CALIF IRVINE,DEPT PHYS,IRVINE,CA 92717. LOS ALAMOS NATL LAB,DIV MAT SCI & TECHNOL,LOS ALAMOS,NM 87545. RP Sarrao, JL (reprint author), FLORIDA STATE UNIV,NATL HIGH MAGNET FIELD LAB,1800 E PAUL DIRAC DR,TALLAHASSEE,FL 32306, USA. RI Mandrus, David/H-3090-2014 NR 26 TC 121 Z9 121 U1 2 U2 10 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 0163-1829 J9 PHYS REV B JI Phys. Rev. B PD NOV 1 PY 1996 VL 54 IS 17 BP 12207 EP 12211 DI 10.1103/PhysRevB.54.12207 PG 5 WC Physics, Condensed Matter SC Physics GA VT681 UT WOS:A1996VT68100071 ER PT J AU Tranquada, JM Buttrey, DJ Sachan, V AF Tranquada, JM Buttrey, DJ Sachan, V TI Incommensurate stripe order in La2-xSrxNiO4 with x=0.225 SO PHYSICAL REVIEW B LA English DT Article ID MAGNETIC CORRELATIONS; PHASE-SEPARATION; LA2NIO4; CHARGE AB In recent studies of La2-xSrxNiO4 it has been suggested that ordering of the dopant-induced holes occurs only commensurately at special values of x, such as 1/3 and 1/2. Commensurate order of both charge and spin densities has also been found in a crystal with x = 0.20. The present neutron scattering study of an x = 0.225 crystal demonstrates that the spin and charge order can also be incommensurate. In fact, the incommensurability is temperature dependent, as observed previously in La2NiO4.125, indicating that such behavior is intrinsic to the doped NiO2 layers and not dependent on ordering of the dopant ions. A careful analysis of the unusual variation of peak widths as a function of momentum transfer perpendicular to the planes shows that the charge- and spin-density modulations are tied to the lattice, with the shift in phase of the charge modulations from one layer to the next equal to exactly one in-plane lattice spacing. A comparison of results for a number of samples shows that the charge and spin ordering temperatures vary linearly with hole concentration, with charge order always occurring at higher temperature, clearly indicating that the ordering is driven by the charge. C1 UNIV DELAWARE,DEPT CHEM ENGN,NEWARK,DE 19716. UNIV DELAWARE,MAT SCI PROGRAM,NEWARK,DE 19716. RP Tranquada, JM (reprint author), BROOKHAVEN NATL LAB,DEPT PHYS,UPTON,NY 11973, USA. RI Tranquada, John/A-9832-2009 OI Tranquada, John/0000-0003-4984-8857 NR 21 TC 159 Z9 159 U1 0 U2 11 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 0163-1829 J9 PHYS REV B JI Phys. Rev. B PD NOV 1 PY 1996 VL 54 IS 17 BP 12318 EP 12323 DI 10.1103/PhysRevB.54.12318 PG 6 WC Physics, Condensed Matter SC Physics GA VT681 UT WOS:A1996VT68100084 ER PT J AU Kogan, VG Gurevich, A Cho, JH Johnston, DC Xu, M Thompson, JR Martynovich, A AF Kogan, VG Gurevich, A Cho, JH Johnston, DC Xu, M Thompson, JR Martynovich, A TI Nonlocal electrodynamics and low-temperature magnetization of clean high-kappa superconductors SO PHYSICAL REVIEW B LA English DT Article ID HIGH-TC SUPERCONDUCTORS; II SUPERCONDUCTORS; VORTEX FLUCTUATIONS; REVERSIBLE MAGNETIZATION; PENETRATION DEPTH; VORTICES; LATTICE; FIELD; T(C); LINE AB We show that magnetic properties of clean superconductors with a large Ginzburg-Landau parameter kappa at low temperatures are affected by the nonlocality of the microscopic current-field relation and can be described by modified London equations. We argue that for clean materials at low temperatures, the standard London formula for the reversible magnetization in intermediate fields, M similar to In(H-c2/B), should contain the field H-0 similar to phi(0)/rho(2) instead of H-c2 similar to phi(0)/xi(2)(T), with rho being the nonlocality range on the order of xi(0), the zero-T coherence length. Since rho depends weakly on T, the magnetization should exhibit an approximate scaling M(T,B)=X(T)Y(B) as observed in Bi- and Tl-based compounds in a broad temperature domain well below T-c. Our expression for the magnetization reduces to the standard London result near T-c and at any temperature for the dirty case. Implications of our results for interpretation of neutron scattering data and for procedures of extracting the penetration depth are discussed. C1 IOWA STATE UNIV,DEPT PHYS,AMES,IA 50011. UNIV WISCONSIN,CTR APPL SUPERCONDUCT,MADISON,WI 53706. LOS ALAMOS NATL LAB,LOS ALAMOS,NM 87545. OAK RIDGE NATL LAB,OAK RIDGE,TN 37831. UNIV TENNESSEE,DEPT PHYS,KNOXVILLE,TN 37996. PHYSTECH,UA-340114 DONETSK,UKRAINE. RP Kogan, VG (reprint author), IOWA STATE UNIV,AMES LAB,AMES,IA 50011, USA. RI Gurevich, Alex/A-4327-2008 OI Gurevich, Alex/0000-0003-0759-8941 NR 42 TC 88 Z9 88 U1 1 U2 3 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 0163-1829 J9 PHYS REV B JI Phys. Rev. B PD NOV 1 PY 1996 VL 54 IS 17 BP 12386 EP 12396 DI 10.1103/PhysRevB.54.12386 PG 11 WC Physics, Condensed Matter SC Physics GA VT681 UT WOS:A1996VT68100091 ER PT J AU Fabbricatore, P Priano, C Sciutti, A Gemme, G Musenich, R Parodi, R Gomory, F Thompson, JR AF Fabbricatore, P Priano, C Sciutti, A Gemme, G Musenich, R Parodi, R Gomory, F Thompson, JR TI Flux pinning in Bi-2212/Ag-based wires and coils SO PHYSICAL REVIEW B LA English DT Article ID BA-CU-O; IRREVERSIBILITY LINE; II SUPERCONDUCTORS; CURRENT-DENSITY; SINGLE-CRYSTAL; VORTICES; CREEP; MECHANISMS; DEPENDENCE; TAPE AB This paper describes a study of pinning forces in Ag/Bi-based wires and small coils. The goal of this analysis is to characterize and to compare the main pinning mechanisms in wires (short samples) and prototype practical devices, e.g., coils (long samples). The effects of thermal activation were found to hinder the straightforward determination of the pinning parameters from the critical current data. However, we succeeded in extracting these parameters from the irreversibility line. The scaling law for the pinning force employing the irreversibility field in virtue of the scale for magnetic fields was derived theoretically. The best fit to the experimentally determined pinning forces gave the Aux-creep model corresponding to the power-law current-voltage dependence J proportional to E(n). C1 SLOVAK ACAD SCI,INST ELECT ENGN,BRATISLAVA 84239,SLOVAKIA. UNIV TENNESSEE,DEPT PHYS,KNOXVILLE,TN 37996. OAK RIDGE NATL LAB,OAK RIDGE,TN 37831. RP Fabbricatore, P (reprint author), IST NAZL FIS NUCL,SEZ GENOVA,VIA DODECANESO 33,I-16146 GENOA,ITALY. RI Gemme, Gianluca/C-7233-2008 OI Gemme, Gianluca/0000-0002-1127-7406 NR 29 TC 26 Z9 27 U1 0 U2 1 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 0163-1829 J9 PHYS REV B JI Phys. Rev. B PD NOV 1 PY 1996 VL 54 IS 17 BP 12543 EP 12550 DI 10.1103/PhysRevB.54.12543 PG 8 WC Physics, Condensed Matter SC Physics GA VT681 UT WOS:A1996VT68100108 ER PT J AU Winokur, MJ Mattes, BR AF Winokur, MJ Mattes, BR TI Determination of the local molecular structure in amorphous polyaniline SO PHYSICAL REVIEW B LA English DT Article ID COUNTERION-INDUCED PROCESSIBILITY; METAL-INSULATOR BOUNDARY; X-RAY-SCATTERING; ELECTRONIC-STRUCTURE; POLYMERS; STATES AB The short-range order within amorphous polyaniline (a-PANI) has been studied through use of a pair-distribution-function analysis of x-ray scattering data in combination with quantitative refinements of model structure functions. Both the emeraldine base and salt (ES) forms of a-PANI are less planar than their crystalline counterparts. Direct evidence for appreciable interchain hydrogen bonding is seen. A probable position of the dopant ions in hydrohalogenic-acid-doped ES has also been ascertained. The intrachain structure and the ion location are such that the effective pi-conjugation length is lowered and the chain-to-chain packing is frustrated. These characteristics hinder charge transport through the polymer matrix and prevent evolution towards a metallic state. C1 LOS ALAMOS NATL LAB,LOS ALAMOS,NM 87545. RP Winokur, MJ (reprint author), UNIV WISCONSIN,DEPT PHYS,1150 UNIV AVE,MADISON,WI 53706, USA. NR 22 TC 10 Z9 10 U1 1 U2 6 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 0163-1829 J9 PHYS REV B JI Phys. Rev. B PD NOV 1 PY 1996 VL 54 IS 18 BP 12637 EP 12640 PG 4 WC Physics, Condensed Matter SC Physics GA VT682 UT WOS:A1996VT68200004 ER PT J AU Salkola, MI Bishop, AR Kenkre, VM Raghavan, S AF Salkola, MI Bishop, AR Kenkre, VM Raghavan, S TI Coupled spin-boson systems far from equilibrium SO PHYSICAL REVIEW B LA English DT Article ID NONLINEAR SCHRODINGER-EQUATION; SEMICLASSICAL APPROXIMATION; QUANTUM; MODEL; DYNAMICS; FIELD AB Nonequilibrium quantum dynamics of a system comprising a (pseudo) spin-1/2 object coupled to a boson degree of freedom is studied. It is shown that the time evolution of the system is described by a set of elementary scattering processes. Through these processes the system approaches an equilibrium in which the spin is in a mixed state that on average maximizes its entropy. However, the irregular behavior of the system is unrelated to ''quantum chaos'' as the Hamiltonian is integrable. C1 LOS ALAMOS NATL LAB, DIV THEORET, LOS ALAMOS, NM 87545 USA. UNIV NEW MEXICO, CTR ADV STUDIES, ALBUQUERQUE, NM 87131 USA. RP Salkola, MI (reprint author), STANFORD UNIV, DEPT PHYS, STANFORD, CA 94305 USA. NR 25 TC 5 Z9 5 U1 1 U2 4 PU AMER PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 1098-0121 EI 1550-235X J9 PHYS REV B JI Phys. Rev. B PD NOV 1 PY 1996 VL 54 IS 18 BP 12645 EP 12648 PG 4 WC Physics, Condensed Matter SC Physics GA VT682 UT WOS:A1996VT68200006 ER PT J AU Krisch, MH Sette, F Bergmann, U Masciovecchio, C Verbeni, R Goulon, J Caliebe, W Kao, CC AF Krisch, MH Sette, F Bergmann, U Masciovecchio, C Verbeni, R Goulon, J Caliebe, W Kao, CC TI Observation of magnetic circular dichroism in resonant inelastic x-ray scattering at the L(3) edge of gadolinium metal SO PHYSICAL REVIEW B LA English DT Article ID CORE-LEVEL PHOTOEMISSION; SPIN POLARIZATION; SPECTRA; EXCITATION; EMISSION; SYSTEMS; NICKEL; ORIGIN; FE AB Magnetic circular dichroism is observed in inelastic x-ray scattering from d core electrons in magnetically aligned gadolinium at incident photon energies resonant with the Gd 2p(3/2) excitations. The dichroism is dominated by the magnetic interactions between the valence 4f electrons and the final state d core hole. Unlike photoabsorption spectroscopy, but similar to core photoelectron spectroscopy, this method allows one to probe electron-correlation effects in the valence ground-state population. C1 BROOKHAVEN NATL LAB,NATL SYNCHROTRON LIGHT SOURCE DEPT,UPTON,NY 11973. RP Krisch, MH (reprint author), EUROPEAN SYNCHROTRON RADIAT FACIL,BOITE POSTALE 220,F-38043 GRENOBLE,FRANCE. NR 20 TC 41 Z9 41 U1 0 U2 1 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 0163-1829 J9 PHYS REV B JI Phys. Rev. B PD NOV 1 PY 1996 VL 54 IS 18 BP 12673 EP 12676 PG 4 WC Physics, Condensed Matter SC Physics GA VT682 UT WOS:A1996VT68200013 ER PT J AU Nowak, ER Anders, S Jaeger, HM Fendrich, JA Kwok, WK Mogilevsky, R Hinks, DG AF Nowak, ER Anders, S Jaeger, HM Fendrich, JA Kwok, WK Mogilevsky, R Hinks, DG TI Vortex localization in single crystals of Tl2Ba2CuO6+delta with columnar defects SO PHYSICAL REVIEW B LA English DT Article ID HIGH-TEMPERATURE SUPERCONDUCTORS; BOSE GLASS SUPERCONDUCTOR; FLUX-CREEP; VORTICES; FILMS; LINE; MAGNETIZATION; RELAXATION; YBA2CU3O7; QUANTUM AB We investigate the effect of columnar defects on the low-temperature magnetic response of a highly anisotropic superconductor. Using a local magnetic field sensor, the vortex creep rate in single crystals of Tl2Ba2CuO6+delta containing columnar defects is found to be a highly nonmonotonic function of vortex density. The creep rate is largest when the vortex density is less than the defect density. A strong suppression of the creep rate is observed near the matching field, B-phi, corresponding to equal numbers of vortices and defects. We tentatively associate this finding with the Mott-insulator line phase proposed by Nelson and Vinokur [Phys. Rev. B 48, 13 060 (1993)]. For higher vortex densities, an additional minimum is found near 3B(phi), emphasizing the importance of vortex interactions. C1 UNIV CHICAGO,DEPT PHYS,CHICAGO,IL 60637. ARGONNE NATL LAB,DIV MAT SCI,ARGONNE,IL 60439. RP Nowak, ER (reprint author), UNIV CHICAGO,JAMES FRANCK INST,5640 S ELLIS AVE,CHICAGO,IL 60637, USA. NR 25 TC 20 Z9 20 U1 0 U2 2 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 0163-1829 J9 PHYS REV B JI Phys. Rev. B PD NOV 1 PY 1996 VL 54 IS 18 BP 12725 EP 12728 PG 4 WC Physics, Condensed Matter SC Physics GA VT682 UT WOS:A1996VT68200026 ER PT J AU Ormeci, A Chu, F Wills, JM Mitchell, TE Albers, RC Thoma, DJ Chen, SP AF Ormeci, A Chu, F Wills, JM Mitchell, TE Albers, RC Thoma, DJ Chen, SP TI Total-energy study of electronic structure and mechanical behavior of C15 laves phase compounds: NbCr2 and HfV2 SO PHYSICAL REVIEW B LA English DT Article ID COMPOUNDS MV2 M=ZR; INTERMETALLIC COMPOUNDS; ELASTIC PROPERTIES; GRAIN-BOUNDARIES; MAGNETISM; STABILITY; ALLOYS; DEFORMATION; SYSTEMS; NI3AL AB First-principles electronic structure calculations based on a full-potential linear muffin-tin orbital method have been used to study the electronic and mechanical properties of the early transition metal C15 Laves phase compounds NbCr2 and HfV2. For both compounds, total energies are computed and compared for the two Laves phase crystal structures C15 and C14. The lower total-energy structure for NbCr2 is found to be the C15 structure as opposed to the C14 structure for HfV2. We have calculated the equilibrium unit cell volumes, bulk moduli, cohesive energies, and heats of formation. We have obtained the density of states and charge density contour plots. Based on these results, we discuss the elastic properties, the stability of the C15 phase, and the bonding and deformation mechanisms in Laves phases. C1 LOS ALAMOS NATL LAB,DIV MAT SCI & TECHNOL,LOS ALAMOS,NM 87545. RP Ormeci, A (reprint author), LOS ALAMOS NATL LAB,DIV THEORET,LOS ALAMOS,NM 87545, USA. RI Ormeci, Alim/F-1082-2012 OI Ormeci, Alim/0000-0001-5468-3378 NR 57 TC 64 Z9 68 U1 1 U2 11 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 0163-1829 J9 PHYS REV B JI Phys. Rev. B PD NOV 1 PY 1996 VL 54 IS 18 BP 12753 EP 12762 DI 10.1103/PhysRevB.54.12753 PG 10 WC Physics, Condensed Matter SC Physics GA VT682 UT WOS:A1996VT68200030 ER PT J AU Desimoni, J Sanchez, FH vanRaap, MBF Lin, XW Bernas, H Clerc, C AF Desimoni, J Sanchez, FH vanRaap, MBF Lin, XW Bernas, H Clerc, C TI Mossbauer study of the Fe-Si phases produced by Fe implantation followed by ion-beam-induced epitaxial crystallization SO PHYSICAL REVIEW B LA English DT Article ID IRON SILICIDE; SPECTROSCOPY; FESI2 AB Iron silicides were produced by 100-keV Fe-57 implantation at room temperature into Si(100), followed by 500-keV Si beam irradiation at 593 K to induce epitaxial crystallization. The iron concentration was varied between 4 and 28 at. %. The Mossbauer spectra associated with Fe-57 probes can be described by means of a broad quadrupole interaction distribution. After thermal treatments at temperatures up to 793 K the spectra become narrower and quadrupole distribution gets closer to that of beta-FeSi2. The fitted interactions are discussed in terms of those of gamma-FeSi2, beta-FeSi2, and alpha-FeSi2 phases which have been observed by high-resolution transmission electron microscopy. Low-temperature measurements of gamma-FeSi2 precipitates prepared by the ion-beam-induced epitaxial crystallization route do not confirm the reported occurrence of magnetic ordering in this system, above 4.2 K. C1 UNIV CALIF BERKELEY,LAWRENCE BERKELEY LAB,DIV MAT SCI,BERKELEY,CA 94720. CTR SPECTROMETRIE NUCL & SPECTROMETRIE MASSE,ORSAY,FRANCE. RP Desimoni, J (reprint author), NATL UNIV LA PLATA,FAC CIENCIAS EXACTAS,DEPT FIS,CC 67,RA-1900 LA PLATA,ARGENTINA. NR 24 TC 16 Z9 16 U1 0 U2 3 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 0163-1829 J9 PHYS REV B JI Phys. Rev. B PD NOV 1 PY 1996 VL 54 IS 18 BP 12787 EP 12792 DI 10.1103/PhysRevB.54.12787 PG 6 WC Physics, Condensed Matter SC Physics GA VT682 UT WOS:A1996VT68200033 ER PT J AU Fuchs, R Barrera, RG Carrillo, JL AF Fuchs, R Barrera, RG Carrillo, JL TI Spectral representations of the electron energy loss in composite media SO PHYSICAL REVIEW B LA English DT Article AB Using a recently developed theory for the inverse longitudinal nonlocal dielectric response for a granular composite [R. G. Barrera and R. Fuchs, Phys. Rev. B 52, 3256 (1995)], we find an effective local dielectric response from the condition that it must give the same electron energy-loss probability density as the actual nonlocal response. This local response is expressed as a spectral representation:a sum of terms with simple poles corresponding to the excitation of bulk and interfacial modes. Taking as a guideline the condition that the strength and location of the poles must satisfy sum rules, a single-surface-mode approximation is proposed. This single-mode approximation is tested for a random system of aluminum spheres in vacuum. C1 IOWA STATE UNIV SCI & TECHNOL,DEPT PHYS,AMES,IA 50011. UNIV NACL AUTONOMA MEXICO,INST FIS,MEXICO CITY 01000,DF,MEXICO. UNIV AUTONOMA PUEBLA,INST FIS LUIS RIVERA TERRAZAS,PUEBLA 72570,MEXICO. RP Fuchs, R (reprint author), IOWA STATE UNIV SCI & TECHNOL,AMES LAB,AMES,IA 50011, USA. NR 13 TC 22 Z9 22 U1 0 U2 1 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 0163-1829 J9 PHYS REV B JI Phys. Rev. B PD NOV 1 PY 1996 VL 54 IS 18 BP 12824 EP 12834 DI 10.1103/PhysRevB.54.12824 PG 11 WC Physics, Condensed Matter SC Physics GA VT682 UT WOS:A1996VT68200038 ER PT J AU Leung, PW Chiu, KC Runge, KJ AF Leung, PW Chiu, KC Runge, KJ TI Columnar dimer and plaquette resonating-valence-bond orders in the quantum dimer model SO PHYSICAL REVIEW B LA English DT Article ID PEIERLS GROUND-STATES; ANTIFERROMAGNETS AB We study the nature of the ground state of the quantum dimer model proposed by Rokhsar and Kivelson by diagonalizing the Hamiltonian of the model on square lattices of size LxL, where L less than or equal to 8, with periodic boundary conditions. Finite-size scaling studies of the columnar order parameter and the low lying excitation spectrum show no evidence of a dimer liquid state in any finite region of the zero temperature phase diagram. In addition, we find evidence of a transition from the columnar dimer state to an intermediate state at a negative value of V/J. This state is consistent with the plaquette resonating-valence-bond state. The energy gap of this state vanishes as a power law of L. It exhibits columnar dimer order, but has disorder within the dimer columns. This state persists up to V/J<1, and the system changes to a dimer liquid state only at V/J=1. C1 LAWRENCE LIVERMORE NATL LAB,DEPT PHYS,LIVERMORE,CA 94551. RP Leung, PW (reprint author), HONG KONG UNIV SCI & TECHNOL,DEPT PHYS,HONG KONG,HONG KONG. NR 17 TC 51 Z9 51 U1 0 U2 0 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 0163-1829 J9 PHYS REV B JI Phys. Rev. B PD NOV 1 PY 1996 VL 54 IS 18 BP 12938 EP 12945 DI 10.1103/PhysRevB.54.12938 PG 8 WC Physics, Condensed Matter SC Physics GA VT682 UT WOS:A1996VT68200051 ER PT J AU Bernal, OO MacLaughlin, DE Amato, A Feyerherm, R Gygax, FN Schenck, A Heffner, RH Le, LP Nieuwenhuys, GJ Andraka, B vonLohneysen, H Stockert, O Ott, HR AF Bernal, OO MacLaughlin, DE Amato, A Feyerherm, R Gygax, FN Schenck, A Heffner, RH Le, LP Nieuwenhuys, GJ Andraka, B vonLohneysen, H Stockert, O Ott, HR TI Kondo disorder and non-Fermi-liquid behavior in UCu5-xPdx and CeCu5.9Au0.1 SO PHYSICAL REVIEW B LA English DT Article ID HEAVY-ELECTRON MATERIALS; MUON-SPIN-RELAXATION; Y1-XUXPD3; ALLOY; UCU5; TRANSITION; SR AB Muon spin rotation (mu SR) has been used to probe non-Fermi-liquid (NFL) behavior in the heavy-fermion alloys UCu5-xPdx, x = 1.0 and 1.5, and CeCu5.9Au0.1 Zero-field mu SR puts an upper bound of similar to 0.01 mu(B)/U atom on any static magnetism in UCu5-xPdx, which is too weak to affect the transverse-field mu SR linewidth or to give rise to NFL behavior. In agreement with NMR results, mu SR spectra in transverse fields suggest that a broad distribution of Kondo temperatures (''Kondo disorder'') is important in UCu5-xPdx. NFL anomalies at temperature T then arise from ''free'' spins for which T-K much less than T. Comparison of mu SR and NMR linewidths also indicates short-range spatial correlation of the Kondo disorder in UCu5-xPdx, in agreement with the local character of the dynamic susceptibility inferred from neutron scattering experiments. In CeCu5.9Au0.1 the data suggest significant Kondo disorder only if the spatial correlation is long ranged, which is not indicated by other properties of this alloy. C1 ETH ZURICH,INST PARTICLE PHYS,CH-5232 VILLIGEN,SWITZERLAND. LOS ALAMOS NATL LAB,LOS ALAMOS,NM 87545. LEIDEN UNIV,KAMERLINGH ONNES LAB,NL-2300 RA LEIDEN,NETHERLANDS. UNIV FLORIDA,DEPT PHYS,GAINESVILLE,FL 32611. ETH HONGGERBERG,FESTKORPERPHYS LAB,D-76128 KARLSRUHE,GERMANY. UNIV KARLSRUHE,INST PHYS,D-76128 KARLSRUHE,GERMANY. CALIF STATE UNIV LOS ANGELES,DEPT PHYS,LOS ANGELES,CA 90032. RP Bernal, OO (reprint author), UNIV CALIF RIVERSIDE,DEPT PHYS,RIVERSIDE,CA 92521, USA. RI Feyerherm, Ralf/F-5487-2013; Amato, Alex/H-7674-2013 OI Feyerherm, Ralf/0000-0003-3034-4210; Amato, Alex/0000-0001-9963-7498 NR 32 TC 41 Z9 41 U1 0 U2 5 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 0163-1829 J9 PHYS REV B JI Phys. Rev. B PD NOV 1 PY 1996 VL 54 IS 18 BP 13000 EP 13008 DI 10.1103/PhysRevB.54.13000 PG 9 WC Physics, Condensed Matter SC Physics GA VT682 UT WOS:A1996VT68200057 ER PT J AU Johnston, DC AF Johnston, DC TI Antiferromagnetic exchange in two-leg spin-1/2 ladders SO PHYSICAL REVIEW B LA English DT Article ID T-J LADDERS; HEISENBERG-ANTIFERROMAGNET; EXCITATION SPECTRUM; MAGNETIC-SUSCEPTIBILITY; TEMPERATURE PROPERTIES; SUPERCONDUCTIVITY; CHAIN; GAPS; SRN-1CUN+1O2N; (VO)2P2O7 AB Extraction of antiferromagnetic (AF) exchange constants J and J' in two-leg spin-1/2 nearest-neighbour (NN) Heisenberg ladders from experimental magnetic spin susceptibility (chi)(T) data is studied, where J' is the NN exchange constant in the rungs and J is that in the legs. Two low-T (T much less than J/k(B)) approximations of Troyer, Tsunetsugu, and Wurtz [Phys. Rev. B 50, 13515 (1994)] for (chi)(T) of the isolated spin-1/2 two-leg ladder with J'/J = 1 are shown to be accurate to similar to 10% when extrapolated to T similar to J/k(B). The variations in the magnetic excitation dispersion relation parameters [which enter the low-T expression of Troyer et al. for (chi)(T)] for J'/J = 1 are inferred from previous theoretical results. Next, the values of the maxima in (chi)(T) = (max)(chi) from many numerical calculations in the literature for various nonfrustrated spin-1/2 NN Heisenberg antiferromagnets are considered. The values of the product (max)(chi)z(eff) are found to depend systematically and almost uniqely on an effective magnetic coordination number z(eff) defined in the text, but are nearly independent of the dimensionality of the spin lattice and of the magnitude of any gap in the magnetic excitation spectrum. This observation allows accurate bounds on the exchange coupling constants in arbitrary quasi-low-dimensional spin-1/2 antiferromagnets to be inferred from experimental (max)(chi) values. Finally, a mean-field-type expression for (chi)(T) for arbitrary quasi-low-dimensional spin-1/2 Heisenberg antiferromagnets is derived, using the above (max)(chi) phenomenology as input, which allows the influence of intersystem coupling on (chi)(T) to be evaluated. These results, and the (chi)(T) calculations of Barnes and Riera [Phys. Rev. B 50, 6817 (1994)] for isolated two-leg spin-1/2 Heisenberg ladders, are used to analyze the experimental (chi)(T) data of Azuma et al. [Phys. Rev. Lett. 73, 3463 (1994)] for the spin-1/2 two-leg ladder compound SrCu2O3. The analyses together suggest that J'/J similar to 0.5, contrary to the expectation that J'/J approximate to 1, and that J is very large (similar to 2000 K), similar to the value of J in the linear-chain cuprate Sr2CuO3. C1 IOWA STATE UNIV SCI & TECHNOL,DEPT PHYS & ASTRON,AMES,IA 50011. RP Johnston, DC (reprint author), US DOE,AMES LAB,AMES,IA 50011, USA. NR 46 TC 66 Z9 66 U1 1 U2 7 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 0163-1829 J9 PHYS REV B JI Phys. Rev. B PD NOV 1 PY 1996 VL 54 IS 18 BP 13009 EP 13016 DI 10.1103/PhysRevB.54.13009 PG 8 WC Physics, Condensed Matter SC Physics GA VT682 UT WOS:A1996VT68200058 ER PT J AU Gurevich, A Benkraouda, M Clem, JR AF Gurevich, A Benkraouda, M Clem, JR TI Vortices at planar defects in layered superconductors SO PHYSICAL REVIEW B LA English DT Article ID HIGH-TC SUPERCONDUCTORS; NONLOCAL JOSEPHSON ELECTRODYNAMICS; HIGH-TEMPERATURE SUPERCONDUCTORS; LOWER CRITICAL-FIELD; OXIDE SUPERCONDUCTORS; MAGNETIC GRANULARITY; II SUPERCONDUCTORS; MODEL; JUNCTIONS; TAPES AB We propose a self-consistent nonlocal approach for the description of vortices in layered supeconductors that contain planar defects parallel to the layers. The model takes account of interlayer Josephson coupling and of a reduced maximum Josephson current density j'(0) across the defect as compared to j(0) for other interlayer junctions. Analytical formulas that describe the structure of both static and moving vortices, including the nonlinear Josephson core region, are obtained. Within the framework of the model, we have calculated the lower critical field H-cl, vortex mass M, viscous drag coefficient mu, and the nonlinear current-voltage characteristic V(j) for a vortex moving along planar defects. It is shown that for identical junctions (j'(0)=j(0)) our approach reproduces results of Clem, Coffey, and Hao [Phys. Rev. B 42, 6209 (1990); 44, 2732 (1991); 44, 6903 (1991)] for mu, M, and H-cl. In the opposite limit j'(0) much less than j(0), our model gives an Abrikosov vortex with anisotropic Josephson core described by a nonlocal Josephson electrodynamics. A sign change in the curvature of V(j) is shown to occur due to a crossover between underdamped (T much less than T-c) and overdamped T similar or equal to T-c dynamics of interlayer junctions as the temperature T is increased. Implications of the results on the c-axis current transport in high-T-c superconductors are discussed. C1 IOWA STATE UNIV SCI & TECHNOL,AMES LAB,AMES,IA 50011. IOWA STATE UNIV SCI & TECHNOL,DEPT PHYS & ASTRON,AMES,IA 50011. RP Gurevich, A (reprint author), UNIV WISCONSIN,CTR APPL SUPERCOND,MADISON,WI 53706, USA. RI Gurevich, Alex/A-4327-2008 OI Gurevich, Alex/0000-0003-0759-8941 NR 60 TC 8 Z9 8 U1 1 U2 3 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 0163-1829 J9 PHYS REV B JI Phys. Rev. B PD NOV 1 PY 1996 VL 54 IS 18 BP 13196 EP 13206 DI 10.1103/PhysRevB.54.13196 PG 11 WC Physics, Condensed Matter SC Physics GA VT682 UT WOS:A1996VT68200081 ER PT J AU Schuttler, HB Norman, MR AF Schuttler, HB Norman, MR TI Contrasting dynamic spin susceptibility models and their relation to high-temperature superconductivity SO PHYSICAL REVIEW B LA English DT Article ID FLUCTUATION-INDUCED SUPERCONDUCTIVITY; 2-DIMENSIONAL HUBBARD-MODEL; COPPER OXIDES; NORMAL-STATE; CONSERVING APPROXIMATIONS; ELECTRON-SYSTEMS; FERMI-SURFACE; METALS; TC; YBA2CU3O7 AB We compare the normal-state resistivities rho and the critical temperatures T-c for superconducting d(x2-y2) pairing due to antiferromagnetic (AF) spin fluctuation exchange in the context of two phenomenological dynamical spin susceptibility models for the cuprate high-T-c materials, one based on fits to NMR data on Y-Ba-Cu-O (YBCO) proposed by Millis, Monien, and Pines (MMP) and Monthoux and Pines (MP), and the other based on fits to neutron scattering data on YBCO proposed by Radtke, Ullah, Levin, and Norman (RULN). Assuming comparable electronic bandwidths and resistivities in both models, we show that the RULN model gives a much lower d-wave T-c (less than or similar to 20 K) than the MMP model (with T-c similar to 100 K). We demonstrate that these profound differences in the T-c's arise from fundamental differences in the spectral weight distributions of the two model susceptibilities at high (>100 meV) frequencies and are not primarily caused by differences in the calculational techniques employed by MP and RULN. Further neutron scattering experiments, to explore the spectral weight distribution at all wave vectors over a sufficiently large excitation energy range, will thus be of crucial importance to resolve the question whether AF spin fluctuation exchange can provide a viable mechanism to account for high-T-c superconductivity. Limitations of the Migdal-Eliashberg approach in such models will be discussed. C1 ARGONNE NATL LAB,DIV MAT SCI,ARGONNE,IL 60439. RP Schuttler, HB (reprint author), UNIV GEORGIA,DEPT PHYS & ASTRON,CTR SIMULAT PHYS,ATHENS,GA 30602, USA. RI Norman, Michael/C-3644-2013 NR 54 TC 17 Z9 17 U1 0 U2 1 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 0163-1829 J9 PHYS REV B JI Phys. Rev. B PD NOV 1 PY 1996 VL 54 IS 18 BP 13295 EP 13305 DI 10.1103/PhysRevB.54.13295 PG 11 WC Physics, Condensed Matter SC Physics GA VT682 UT WOS:A1996VT68200092 ER PT J AU Yokoya, T Chainani, A Takahashi, T Ding, H Campuzano, JC KatayamaYoshida, H Kasai, M Tokura, Y AF Yokoya, T Chainani, A Takahashi, T Ding, H Campuzano, JC KatayamaYoshida, H Kasai, M Tokura, Y TI Angle-resolved photoemission study of Sr2RuO4 SO PHYSICAL REVIEW B LA English DT Article ID SADDLE-POINT SINGULARITY; BAND-STRUCTURE; FERMI-SURFACE; TRANSITION; YBA2CU4O8; SR2IR1-XRUXO4; SPECTROSCOPY; YBA2CU3O6.9 AB We present high-resolution (HR) angle-resolved photoemission spectroscopy (ARPES) measurements of the noncuprate layered perovskite superconductor Sr2RuO4. ARPES spectra of the whole valence-band region obtained along two high-symmetry directions in the Brillouin zone show clear dispersion, generally similar to that of a band calculation. However, HRARPES measurements taken in the vicinity of the Fermi level (E(F)) show narrower Ru4d epsilon(xy,yz,zx)-O2p pi antibonding bands than those predicted by the band calculation. More significantly, there is an extended van Hove singularity very close to E(F) (E(B)=11 meV) along the Ru-O bonding direction, which is known to exist in cuprate high-temperature superconductors. The Fermi-surface topology obtained by HRARPES (one electronlike Fermi surface sheet centered at the Gamma point and two holelike sheets centered at the X point) is different from the band calculation (two electronlike sheets centered at the Gamma point and one holelike sheet centered at the X point), although the electron count is the same in both cases. These results suggest that electron-electron correlations cause the modification of the Fermi-surface topology, and is thus necessary for understanding the electronic structure and properties of Sr2RuO4. C1 ARGONNE NATL LAB, DIV MAT SCI, ARGONNE, IL 60439 USA. UNIV ILLINOIS, DEPT PHYS, CHICAGO, IL 60607 USA. OSAKA UNIV, INST SCI & IND RES, IBARAKI, OSAKA 567, JAPAN. JOINT RES CTR ATOM TECHNOL, TSUKUBA, IBARAKI 305, JAPAN. UNIV TOKYO, DEPT APPL PHYS, TOKYO 113, JAPAN. RP TOHOKU UNIV, DEPT PHYS, SENDAI, MIYAGI 98077, JAPAN. RI Takahashi, Takashi/E-5080-2010; Tohoku, Arpes/A-4890-2010; Tokura, Yoshinori/C-7352-2009; Chainani, Ashish/B-3071-2011; Campuzano, Juan Carlos/G-4358-2012; YOKOYA, Takayoshi/B-1478-2011; OI Chainani, Ashish/0000-0002-5639-5393; Ding, Hong/0000-0003-4422-9248 NR 25 TC 53 Z9 53 U1 1 U2 9 PU AMER PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 2469-9950 EI 2469-9969 J9 PHYS REV B JI Phys. Rev. B PD NOV 1 PY 1996 VL 54 IS 18 BP 13311 EP 13318 DI 10.1103/PhysRevB.54.13311 PG 8 WC Physics, Condensed Matter SC Physics GA VT682 UT WOS:A1996VT68200094 ER PT J AU Blatter, G Ivlev, B Vinokur, V AF Blatter, G Ivlev, B Vinokur, V TI Quantum depinning of vortices in type-II superconductors SO PHYSICAL REVIEW B LA English DT Article ID HIGH-TEMPERATURE SUPERCONDUCTORS; HIGH-TC SUPERCONDUCTORS; DISTORTED VORTEX LATTICE; LAYERED SUPERCONDUCTORS; BOSON LOCALIZATION; ORDER PARAMETER; ELASTIC ENERGY; MAGNETIC-FIELD; FLUX CREEP; LINES AB We investigate the phenomenon of quantum depinning of vortices in high resistivity amorphous thin films and in high temperature superconductors for the situation of weak collective pinning. Fluctuations of the vortex system produce a smoothing of the pinning potential and thereby a strong renormalization of the critical current density j(c)(T)proportional to(1+[u(2)]/xi(2))(-kappa), With large exponents kappa(2D)=5/2 and kappa(3D)=11/2 for the regimes where the collective pinning involves two- and three-dimensional bundles of vortices. We determine the mean squared displacement amplitude [u(2)] within a quantum statistical ensemble for the cases of a dissipative vortex dynamics (amorphous material) and for a Hamiltonian dynamics dominated by the Hall force (oxide superconductors) and present results for the renormalized critical current density j(c)(T). C1 UNIV AUTONOMA SAN LUIS POTOSI, INST FIS, SAN LUIS POTOSI, MEXICO. ARGONNE NATL LAB, ARGONNE, IL 60439 USA. RP Blatter, G (reprint author), ETH HONGGERBERG, CH-8093 ZURICH, SWITZERLAND. NR 47 TC 1 Z9 1 U1 0 U2 1 PU AMER PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 1098-0121 J9 PHYS REV B JI Phys. Rev. B PD NOV 1 PY 1996 VL 54 IS 18 BP 13330 EP 13338 DI 10.1103/PhysRevB.54.13330 PG 9 WC Physics, Condensed Matter SC Physics GA VT682 UT WOS:A1996VT68200097 ER PT J AU Wu, S Kaplan, SG Lihn, HTS Drew, HD Hou, SY Phillips, JM Barbour, JC Venturini, EL Li, Q Fenner, DB AF Wu, S Kaplan, SG Lihn, HTS Drew, HD Hou, SY Phillips, JM Barbour, JC Venturini, EL Li, Q Fenner, DB TI Temperature dependence of the far-infrared magnetotransmission of YBa2Cu3O7-delta films SO PHYSICAL REVIEW B LA English DT Article ID DENSITY-OF-STATES; II SUPERCONDUCTORS; SURFACE IMPEDANCE; SINGLE-CRYSTALS; MAGNETIC-FIELD; THIN-FILMS; VORTEX; YBA2CU3O6.95; CONDUCTIVITY; NODES AB Measurements in circularly polarized light from 5 to 28 cm(-1) in magnetic fields up to 9T are reported. The zero field response is independent of temperature for T less than or equal to 30 K for clean samples and linear in T for films irradiated with alpha particles. Ln field the transmission of the left circular polarization varies linearly with temperature up to 30 K and the right circular response is independent of temperature. The difference is maximum at lowest temperatures corresponding to an electron active response and reverses sign at 20 K, These results are interpreted in terms of the effects of thermally excited quasiparticles in the mixed state. C1 LAB PHYS SCI,COLLEGE PK,MD 20740. AT&T BELL LABS,MURRAY HILL,NJ 07974. SANDIA NATL LABS,ALBUQUERQUE,NM 87185. ADV FUEL RES,E HARTFORD,CT 06138. RP Wu, S (reprint author), UNIV MARYLAND,DEPT PHYS,CTR SUPERCOND RES,COLLEGE PK,MD 20742, USA. NR 29 TC 9 Z9 10 U1 1 U2 5 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 0163-1829 J9 PHYS REV B JI Phys. Rev. B PD NOV 1 PY 1996 VL 54 IS 18 BP 13343 EP 13347 DI 10.1103/PhysRevB.54.13343 PG 5 WC Physics, Condensed Matter SC Physics GA VT682 UT WOS:A1996VT68200099 ER PT J AU Gill, RL Casten, RF Phillips, WR Varley, BJ Lister, CJ Durell, JL Shannon, JA Warner, DD AF Gill, RL Casten, RF Phillips, WR Varley, BJ Lister, CJ Durell, JL Shannon, JA Warner, DD TI New levels in Er-168: Use of a Compton-suppressed Ge array with the (n,gamma) reaction SO PHYSICAL REVIEW C LA English DT Article ID IDENTIFICATION; SPECTROMETER AB For the first time an (n, gamma) reaction has been extensively studied using a large array of Compton-suppressed Ge detectors (the TESSA array). The nucleus Er-168 was studied and the data show substantial improvement, in both quantity and quality, over previous coincidence data. Even though Er-168 is perhaps the best studied deformed nucleus, over 250 new coincidence relations and a number of new levels in Er-168 were disclosed, demonstrating the usefulness of this approach. Nuclear physics applications relate to the extension of nearly complete spectroscopy to higher excitation energies and to the study of statistical and chaotic features of the decay of low spin compound nuclear levels. C1 YALE UNIV,WRIGHT NUCL STRUCT LAB,NEW HAVEN,CT 06520. UNIV MANCHESTER,DEPT PHYS & ASTRON,MANCHESTER M13 9PL,LANCS,ENGLAND. ARGONNE NATL LAB,DEPT PHYS,ARGONNE,IL 60439. SERC,DARESBURY LAB,WARRINGTON WA4 4AD,CHESHIRE,ENGLAND. RP Gill, RL (reprint author), BROOKHAVEN NATL LAB,DEPT PHYS,UPTON,NY 11973, USA. NR 8 TC 12 Z9 12 U1 0 U2 1 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 0556-2813 J9 PHYS REV C JI Phys. Rev. C PD NOV PY 1996 VL 54 IS 5 BP 2276 EP 2286 DI 10.1103/PhysRevC.54.2276 PG 11 WC Physics, Nuclear SC Physics GA VT672 UT WOS:A1996VT67200026 ER PT J AU Krieger, SJ Bonche, P Flocard, H Heenen, PH Mehrem, R Weiss, MS AF Krieger, SJ Bonche, P Flocard, H Heenen, PH Mehrem, R Weiss, MS TI Generator coordinate method calculation of the E2 decay lifetime of shape isomers in the actinide region SO PHYSICAL REVIEW C LA English DT Article AB We apply the generator coordinate method in a fully microscopic calculation of the E2 decay lifetime of the shape isomeric states of U-236, U-238, and Pu-240. The basis states have been generated by constrained Hartree-Fock Bardeen-Cooper-Schrieffer calculations with the SkM* force. Triaxial quadrupole deformations have been included. Implications upon the decay lifetime of the quasidegeneracy of the isomeric state and the one-phonon excitation in the first well are examined. C1 INST PHYS NUCL,DIV PHYS THEOR,F-91406 ORSAY,FRANCE. FREE UNIV BRUSSELS,SERV PHYS NUCL THEOR,B-1050 BRUSSELS,BELGIUM. CTR ETUD SACLAY,DSM,SPHT,F-91191 GIF SUR YVETTE,FRANCE. UNITED ARAB EMIRATES UNIV,FAC SCI,AL AIN,U ARAB EMIRATES. RP Krieger, SJ (reprint author), LAWRENCE LIVERMORE NATL LAB,DEPT PHYS,LIVERMORE,CA 94550, USA. NR 11 TC 17 Z9 17 U1 0 U2 2 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 0556-2813 J9 PHYS REV C JI Phys. Rev. C PD NOV PY 1996 VL 54 IS 5 BP 2399 EP 2403 DI 10.1103/PhysRevC.54.2399 PG 5 WC Physics, Nuclear SC Physics GA VT672 UT WOS:A1996VT67200040 ER PT J AU Carlton, RF Harvey, JA Hill, NW AF Carlton, RF Harvey, JA Hill, NW TI Total cross section and resonance spectroscopy for n+Sn-124 SO PHYSICAL REVIEW C LA English DT Article ID NEUTRON ELASTIC-SCATTERING; OPTICAL-MODEL; TIN ISOTOPES; AVERAGE AB The neutron total cross section of Sn-124 has been measured over the energy range 0.014-0.315 MeV. An R-matrix analysis has been performed to obtain resonance and average parameters which provide for a complete representation of the neutron entrance channels for the s(1/2), p(1/2), and p(3/2) contributions. The s- and p-wave neutron strength functions have been determined (for a channel radius of 7.23 fm) to be 0.12 +/- 0.03 and 1.8+/-0.2, respectively (in units of 10(-4)). Limits are placed on the average level spacings and strength functions for the individual partial-wave components. The number of definite p(1/2) levels exceeds the p(3/2) levels by the factor 2 and their average strengths differ by the factor 4. s- and p-wave potential scattering radii have been determined to be 6.4+/-0.2 fm and 10.5+/-0.3 fm, respectively. Average scattering functions, deduced from the average parameters, have been used to determine the real well depth of an optical-model potential which reproduces these functions. There is evidence of an angular momentum dependence of the real-well potential depth and the level spacings. C1 OAK RIDGE NATL LAB,OAK RIDGE,TN 37831. RP Carlton, RF (reprint author), MIDDLE TENNESSEE STATE UNIV,DEPT PHYS & ASTRON,MURFREESBORO,TN 37132, USA. NR 25 TC 4 Z9 4 U1 0 U2 0 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 0556-2813 J9 PHYS REV C JI Phys. Rev. C PD NOV PY 1996 VL 54 IS 5 BP 2445 EP 2456 DI 10.1103/PhysRevC.54.2445 PG 12 WC Physics, Nuclear SC Physics GA VT672 UT WOS:A1996VT67200045 ER PT J AU Wuosmaa, AH Back, BB Betts, RR Freer, M Glagola, BG Henderson, DJ Hofman, DJ Nanal, V AF Wuosmaa, AH Back, BB Betts, RR Freer, M Glagola, BG Henderson, DJ Hofman, DJ Nanal, V TI Resonance spin assignments in C-12+C-12(3(-)) inelastic scattering from angular correlation methods SO PHYSICAL REVIEW C LA English DT Article ID MOLECULAR RESONANCES; C-12 COLLISIONS; ALIGNMENT; SYSTEM AB Angular correlation techniques have been used to determine the spin of a strong resonance observed in the C-12 + C-12(3(-);9.64 MeV) inelastic scattering channel, at a bombarding energy of 33.5 MeV in the center-of-mass system. The alpha particles produced in the sequential decay C-12(3(-))-->Be-8(g.s.) + alpha(0) were detected using four double-sided silicon strip detectors. The data are consistent with a spin assignment of J(pi)=18(+) for this resonance. The current results are compared to calculations of resonance behavior in this system from the band crossing model. RP Wuosmaa, AH (reprint author), ARGONNE NATL LAB,DIV PHYS,ARGONNE,IL 60439, USA. RI Freer, Martin/F-9379-2013 NR 25 TC 7 Z9 7 U1 0 U2 0 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 0556-2813 J9 PHYS REV C JI Phys. Rev. C PD NOV PY 1996 VL 54 IS 5 BP 2463 EP 2468 DI 10.1103/PhysRevC.54.2463 PG 6 WC Physics, Nuclear SC Physics GA VT672 UT WOS:A1996VT67200047 ER PT J AU Gavin, S McGaughey, PL Ruuskanen, PV Vogt, R AF Gavin, S McGaughey, PL Ruuskanen, PV Vogt, R TI Lepton production from charm decay in nuclear collisions at root s=200 GeV and 5.5 TeV per nucleon SO PHYSICAL REVIEW C LA English DT Article ID QUARK-GLUON PLASMA; HEAVY-ION COLLISIONS; TO-LEADING ORDER; HADRONIC COLLISIONS; CROSS-SECTION; PARTON DISTRIBUTIONS; PARTICLE-PRODUCTION; QCD CORRECTIONS; PP COLLISIONS; DEPENDENCE AB Measurements of dilepton production from charm decay and Drell-Yan processes, respectively, probe the gluon and sea quark distributions in hadronic collisions. In nucleus-nucleus collisions, these hard scattering processes constitute a ''background'' to thermal contributions from the hot matter produced by the collision. To determine the magnitude and behavior of this background, we calculate the hard scattering contribution to dilepton production in nuclear collisions at RHIC and LHC at next to leading order in perturbative QCD. Invariant mass, rapidity, and transverse momentum distributions are presented. We compare these results to optimistic hydrodynamic estimates of the thermal dilepton production. We find that charm production from hard scattering is by far the dominant contribution. Experiments therefore can measure the gluon distribution in the nuclear target and projectile and, consequently, can provide new information on gluon shadowing. We then illustrate how experimental cuts on the rapidly gap between the leptons can aid in reducing the charm background, thereby enhancing thermal information. C1 LOS ALAMOS NATL LAB,LOS ALAMOS,NM 87545. UNIV JYVASKYLA,DEPT PHYS,JYVASKYLA,FINLAND. UNIV CALIF BERKELEY,LAWRENCE BERKELEY LAB,DIV NUCL SCI,BERKELEY,CA 94720. UNIV CALIF DAVIS,DEPT PHYS,DAVIS,CA 95616. RP Gavin, S (reprint author), BROOKHAVEN NATL LAB,DEPT PHYS,UPTON,NY 11973, USA. NR 71 TC 67 Z9 67 U1 0 U2 0 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 0556-2813 J9 PHYS REV C JI Phys. Rev. C PD NOV PY 1996 VL 54 IS 5 BP 2606 EP 2623 DI 10.1103/PhysRevC.54.2606 PG 18 WC Physics, Nuclear SC Physics GA VT672 UT WOS:A1996VT67200063 ER PT J AU Sato, T Lee, TSH AF Sato, T Lee, TSH TI Meson-exchange model for pi N scattering and gamma N->pi N reaction SO PHYSICAL REVIEW C LA English DT Article ID CHIRAL PERTURBATION-THEORY; PARTIAL-WAVE ANALYSIS; QUARK-MODEL; DELTA(1232) REGION; NUCLEON SCATTERING; BARYON RESONANCES; UNITARY THEORY; PHOTOPRODUCTION; ELECTROPRODUCTION; DEUTERON AB An effective Hamiltonian consisting of bare Delta <---->pi N, gamma N vertex interactions and energy-independent meson-exchange pi N <---->pi N, gamma N transition operators is derived by applying a unitary transformation to a model Lagrangian with N,Delta,pi,rho,omega and gamma fields. With appropriate phenomenological form factors and coupling constants for rho and Delta, the model can give a good description of pi N scattering phase shifts up to the Delta excitation energy region. It is shown that the best reproduction of the recent LEGS data of the photon-asymmetry ratios in gamma p-->pi(0)p reactions provides rather restricted constraints on the coupling strengths G(E) of the electric E2 and G(M) of the magnetic M1 transitions of the bare Delta <---->gamma N vertex and the less well-determined coupling constant g(omega NN) of omega meson. Within the ranges that G(M)=1.9+/-0.05, G(E)=0.0+/-0.025, and 7 less than or equal to g(omega NN)less than or equal to 10.5, the predicted differential cross sections and photon-asymmetry ratios are in an overall good agreement with the data of gamma p-->pi(0)p, gamma p-->pi(+)n, and gamma n-->pi(-)p reactions from 180 MeV to the Delta excitation region. The predicted M(1+) and E(1+) multipole amplitudes are also in good agreement with the empirical values determined by the amplitude analyses. The constructed effective Hamiltonian is free of the nucleon renormalization problem and hence is suitable for nuclear many-body calculations. We have also shown that the assumptions made in the K-matrix method, commonly used in extracting empirically the gamma N-->Delta transition amplitudes from the data, an consistent with our meson-exchange dynamical model. It is found that the helicity amplitudes calculated from our bare gamma N-->Delta vertex are in good agreement with the predictions of the constituent quark model. The differences between these bare amplitudes and the dressed amplitudes, which are closer to the empirical values listed by the Particle Data Group, are shown to be due to the nonresonant meson exchange mechanisms. Within the range 7 less than or equal to g(omega NN)less than or equal to 10.5 of the omega meson coupling favored by the data of the photon-asymmetry ratios in gamma p-->pi(0)p reactions, our values of the E2/M1 ratio for the gamma N-->Delta transition are (0.0+/-1.3)% for the bare vertex and (-1.8+/-0.9)% for the dressed vertex. C1 OSAKA UNIV,DEPT PHYS,TOYONAKA,OSAKA 560,JAPAN. RP Sato, T (reprint author), ARGONNE NATL LAB,DIV PHYS,ARGONNE,IL 60439, USA. NR 67 TC 279 Z9 279 U1 0 U2 0 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 0556-2813 J9 PHYS REV C JI Phys. Rev. C PD NOV PY 1996 VL 54 IS 5 BP 2660 EP 2684 DI 10.1103/PhysRevC.54.2660 PG 25 WC Physics, Nuclear SC Physics GA VT672 UT WOS:A1996VT67200067 ER PT J AU Athanassopoulos, C Auerbach, LB Burman, RL Cohen, I Caldwell, DO Dieterle, BD Donahue, JB Eisner, AM Fazely, A Federspiel, FJ Garvey, GT Gray, M Gunasingha, RM Imlay, R Johnston, K Kim, HJ Louis, WC Majkic, R Margulies, J McIlhany, K Metcalf, W Mills, GB Reeder, RA Sandberg, V Smith, D Stancu, I Strossman, W Tayloe, R VanDalen, GJ Vernon, W Wadia, N Waltz, J Wang, YX White, DH Works, D Xiao, Y Yellin, S AF Athanassopoulos, C Auerbach, LB Burman, RL Cohen, I Caldwell, DO Dieterle, BD Donahue, JB Eisner, AM Fazely, A Federspiel, FJ Garvey, GT Gray, M Gunasingha, RM Imlay, R Johnston, K Kim, HJ Louis, WC Majkic, R Margulies, J McIlhany, K Metcalf, W Mills, GB Reeder, RA Sandberg, V Smith, D Stancu, I Strossman, W Tayloe, R VanDalen, GJ Vernon, W Wadia, N Waltz, J Wang, YX White, DH Works, D Xiao, Y Yellin, S TI Evidence for neutrino oscillations from muon decay at rest SO PHYSICAL REVIEW C LA English DT Article ID REACTION CROSS-SECTIONS; NUCLEAR-POWER-REACTOR; ATMOSPHERIC NEUTRINOS; ELECTRON-NEUTRINO; NU-MU; SEARCH; LIMITS; (NU)OVER-BAR(MU)->(NU)OVER-BAR(E); RATIO; RANGE AB A search for <(nu)over bar>(mu)--><(nu)over bar>(e) oscillations has been conducted at the Los Alamos Meson Physics Facility using <(nu)over bar>(mu) from mu(+) decay at rest. The <(nu)over bar>(e) are detected via the reaction <(nu)over bar>(e)p-->e(+)n, correlated with the 2.2 MeV gamma from np-->d gamma. The use of tight cuts to identify e(+) events with correlated gamma rays yields 22 events with e(+) energy between 36 and 60 MeV and only 4.6+/-0.6 background events. The probability that this excess is due entirely to a statistical fluctuation is 4.1X10(-8). A chi(2) fit to the entire e(+) sample results in a total excess of 51.0(-19.5)(+20.2)+/-8.0 events with e(+) energy between 20 and 60 MeV. If attributed to <(nu)over bar>(mu)--><(nu)over bar>(e) oscillations, this corresponds to an oscillation probability (averaged over the experimental energy and spatial acceptance) of (0.31+/-0.12+/-0.05)%. C1 UNIV CALIF SAN DIEGO,SAN DIEGO,CA 92093. UNIV CALIF SANTA BARBARA,SANTA BARBARA,CA 93106. UNIV CALIF INTERCAMPUS INST RES PARTICLE ACCELERA,STANFORD,CA 94309. EMBRY RIDDLE AERONAUT UNIV,PRESCOTT,AZ 86301. LINFIELD COLL,MCMINNVILLE,OR 97128. LOS ALAMOS NATL LAB,LOS ALAMOS,NM 87545. LOUISIANA STATE UNIV,BATON ROUGE,LA 70803. LOUISIANA TECH UNIV,RUSTON,LA 71272. UNIV NEW MEXICO,ALBUQUERQUE,NM 87131. SO UNIV,BATON ROUGE,LA 70813. TEMPLE UNIV,PHILADELPHIA,PA 19122. RP Athanassopoulos, C (reprint author), UNIV CALIF RIVERSIDE,RIVERSIDE,CA 92521, USA. NR 47 TC 318 Z9 319 U1 0 U2 2 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 0556-2813 J9 PHYS REV C JI Phys. Rev. C PD NOV PY 1996 VL 54 IS 5 BP 2685 EP 2708 DI 10.1103/PhysRevC.54.2685 PG 24 WC Physics, Nuclear SC Physics GA VT672 UT WOS:A1996VT67200068 ER PT J AU Gao, H Holt, RJ Pandharipande, VR AF Gao, H Holt, RJ Pandharipande, VR TI gamma n->pi(-)p process in He-4 and O-16 SO PHYSICAL REVIEW C LA English DT Article ID ELECTRON-NUCLEUS SCATTERING; MOMENTUM-TRANSFER; PROTON PROPAGATION; E,E'P REACTION; A-DEPENDENCE; TRANSPARENCY; STATE AB Nuclear transparencies for the fundamental process gamma n-->pi(-)p on He-4 and O-16 have been calculated using nucleon configurations obtained from realistic ground-state wave functions by the Monte Carlo method. Comparisons between nuclear transparency results using nucleon configurations and the correlated Glauber approximation are made in the case of (e,e'p) on He-4 and O-16. Furthermore, nuclear transparencies for the gamma n-->pi(-)p and (e,e'p) processes have been calculated including a color transparency effect. C1 UNIV ILLINOIS,URBANA,IL 61801. RP Gao, H (reprint author), ARGONNE NATL LAB,9700 S CASS AVE,ARGONNE,IL 60439, USA. RI Gao, Haiyan/G-2589-2011; Holt, Roy/E-5803-2011 NR 23 TC 18 Z9 18 U1 0 U2 0 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 0556-2813 J9 PHYS REV C JI Phys. Rev. C PD NOV PY 1996 VL 54 IS 5 BP 2779 EP 2782 DI 10.1103/PhysRevC.54.2779 PG 4 WC Physics, Nuclear SC Physics GA VT672 UT WOS:A1996VT67200080 ER PT J AU Jolos, RV vonBrentano, P Zamfir, NV Casten, RF AF Jolos, RV vonBrentano, P Zamfir, NV Casten, RF TI Simple formula for E(4(1)(+))-E(2(1)(+)) correlations and the magnification of structural anomalies SO PHYSICAL REVIEW C LA English DT Article ID ANHARMONIC VIBRATOR DESCRIPTION; NUCLEI; MODEL AB A recently proposed correlation of quasiground band energies in collective nuclei is shown to provide a highly sensitive indicator of different classes of nuclei and to lead to an empirical analytic formula for these energies. C1 JOINT INST NUCL RES,DUBNA,RUSSIA. BROOKHAVEN NATL LAB,UPTON,NY 11973. CLARK UNIV,WORCESTER,MA 01610. YALE UNIV,WRIGHT NUCL STRUCT LAB,NEW HAVEN,CT 06520. INST ATOM PHYS,R-76900 BUCHAREST,ROMANIA. RP Jolos, RV (reprint author), UNIV COLOGNE,INST KERNPHYS,D-50937 COLOGNE,GERMANY. RI Zamfir, Nicolae Victor/F-2544-2011 NR 8 TC 3 Z9 3 U1 0 U2 1 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 0556-2813 J9 PHYS REV C JI Phys. Rev. C PD NOV PY 1996 VL 54 IS 5 BP R2146 EP R2149 PG 4 WC Physics, Nuclear SC Physics GA VT672 UT WOS:A1996VT67200010 ER PT J AU Krucken, R Hackman, G Deleplanque, MA Janssens, RVF LEe, IY Ackermann, D Ahmad, I Amro, H Asztalos, S Blumenthal, DJ Carpenter, MP Clark, RM Diamond, RM Fallon, P Fischer, SM Herskind, B Khoo, TL Lauritsen, T MAcchiavelli, AO MacLeod, RW Nisius, D Schmid, GJ Stephens, FS Vetter, K AF Krucken, R Hackman, G Deleplanque, MA Janssens, RVF LEe, IY Ackermann, D Ahmad, I Amro, H Asztalos, S Blumenthal, DJ Carpenter, MP Clark, RM Diamond, RM Fallon, P Fischer, SM Herskind, B Khoo, TL Lauritsen, T MAcchiavelli, AO MacLeod, RW Nisius, D Schmid, GJ Stephens, FS Vetter, K TI Test of Delta I=2 staggering in the superdeformed bands of Hg-194 SO PHYSICAL REVIEW C LA English DT Article ID C-4 SYMMETRY; BIFURCATION AB The presence of Delta I=2 staggering in the three known superdeformed (SD) bands of Hg-194 has been reexamined in a new experiment with Gammasphere. A relative precision of better than 60 eV was achieved for most transition energies. Staggering plots were extracted and their statistical significance was analyzed. No clear evidence was found for an extended regular Delta I=2 staggering in the three SD bands of Hg-194. However, statistically significant deviations from a smooth reference were observed in the two excited SD bands. Different scenarios are discussed but no firm conclusion about the origin of the observed deviations can be drawn. C1 ARGONNE NATL LAB,ARGONNE,IL 60439. UNIV COPENHAGEN,NIELS BOHR INST,DK-2100 COPENHAGEN,DENMARK. RP Krucken, R (reprint author), UNIV CALIF BERKELEY,LAWRENCE BERKELEY LAB,DIV NUCL SCI,1 CYCLOTRON RD,BERKELEY,CA 94720, USA. RI Carpenter, Michael/E-4287-2015; Kruecken, Reiner/A-1640-2013 OI Carpenter, Michael/0000-0002-3237-5734; Kruecken, Reiner/0000-0002-2755-8042 NR 25 TC 37 Z9 37 U1 0 U2 0 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 0556-2813 J9 PHYS REV C JI Phys. Rev. C PD NOV PY 1996 VL 54 IS 5 BP R2109 EP R2113 PG 5 WC Physics, Nuclear SC Physics GA VT672 UT WOS:A1996VT67200002 ER PT J AU Schlei, BR Xu, N AF Schlei, BR Xu, N TI M perpendicular to, dependence of Bose-Einstein correlation radii SO PHYSICAL REVIEW C LA English DT Article ID HEAVY-ION COLLISIONS; HIGH-ENERGY COLLISIONS; RELATIVISTIC HYDRODYNAMICS; PION INTERFEROMETRY; EXPANSION AB Within a theoretical study using both HYLANDER and RQMD, we revisit Bose-Einstein correlation measurements of 200A GeV S+S and 160A GeV Pb+Pb. Transverse flow does not show up in the Bose-Einstein measurements. The decrease of the effective transverse radius parameters with increasing transverse average momentum of the particle pair is largely due to the effect of resonance decays. C1 LOS ALAMOS NATL LAB,P25,LOS ALAMOS,NM 87545. RP Schlei, BR (reprint author), LOS ALAMOS NATL LAB,DIV THEORET,LOS ALAMOS,NM 87545, USA. NR 35 TC 14 Z9 14 U1 0 U2 0 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 0556-2813 J9 PHYS REV C JI Phys. Rev. C PD NOV PY 1996 VL 54 IS 5 BP R2155 EP R2158 PG 4 WC Physics, Nuclear SC Physics GA VT672 UT WOS:A1996VT67200012 ER PT J AU Ambrosanio, S Kane, GL Kribs, GD Martin, SP Mrenna, S AF Ambrosanio, S Kane, GL Kribs, GD Martin, SP Mrenna, S TI Search for supersymmetry with a light gravitino at the Fermilab Tevatron and CERN LEP colliders SO PHYSICAL REVIEW D LA English DT Article ID RADIATIVE-CORRECTIONS; STANDARD MODEL; E+E ANNIHILATION; BREAKING; UNITARITY; PHYSICS; TECHNICOLOR; ENERGIES; PHOTINOS; GAUGINO AB We analyze the prospects for discovering supersymmetry at the Fermilab Tevatron and CERN LEP colliders in the scenario that the lightest supersymmetric particle is a gravitino of mass less than or similar to 1 keV. We consider in particular the case that the lightest neutralino has a nearly 100% branching fraction into gravitino+photon within the detector. This implies that supersymmetric events should contain both missing (transverse) energy and two energetic photons. Therefore, one can search for supersymmetry simply through inclusive production of superpartners. We consider the exclusion and reach capabilities of the Tevatron in exploring the supersymmetric parameter space, and study the efficiencies which can be achieved in this search. We also consider the discovery reach and backgrounds at LEP with root s=160, 175, and 190 GeV. C1 ARGONNE NATL LAB,DIV HIGH ENERGY PHYS,ARGONNE,IL 60439. RP Ambrosanio, S (reprint author), UNIV MICHIGAN,RANDALL LAB PHYS,ANN ARBOR,MI 48109, USA. NR 66 TC 173 Z9 174 U1 0 U2 1 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 0556-2821 J9 PHYS REV D JI Phys. Rev. D PD NOV 1 PY 1996 VL 54 IS 9 BP 5395 EP 5411 DI 10.1103/PhysRevD.54.5395 PG 17 WC Astronomy & Astrophysics; Physics, Particles & Fields SC Astronomy & Astrophysics; Physics GA VQ283 UT WOS:A1996VQ28300001 ER PT J AU Atwood, D BarShalom, S Eilam, G Soni, A AF Atwood, D BarShalom, S Eilam, G Soni, A TI CP nonconservation in p(p)over-bar->t(b)over-bar-X at the Fermilab Tevatron SO PHYSICAL REVIEW D LA English DT Article ID QUARK PAIR PRODUCTION; TOP-QUARK; HIGGS SECTOR; VIOLATION; DECAYS; SUPERCOLLIDERS; POLARIZATION; ASYMMETRY; COLLIDERS; MODELS AB The reaction --> is found to be rather rich in exhibiting several different types of CP asymmetries. The spin of the top quark plays an important role. Asymmetries are related to form factors arising from radiative corrections of the tbW production vertex due to nonstandard physics. As illustrations, effects are studied in two Higgs doublet models and in supersymmetric models; asymmetries up to a few percent may be possible. C1 TECHNION ISRAEL INST TECHNOL,DEPT PHYS,IL-32000 HAIFA,ISRAEL. BROOKHAVEN NATL LAB,DEPT PHYS,UPTON,NY 11973. RP Atwood, D (reprint author), CONTINUOUS ELECTRON BEAM ACCELERATOR FACIL CTR,THEORY GRP,NEWPORT NEWS,VA 23606, USA. NR 25 TC 40 Z9 41 U1 0 U2 0 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 0556-2821 J9 PHYS REV D JI Phys. Rev. D PD NOV 1 PY 1996 VL 54 IS 9 BP 5412 EP 5416 DI 10.1103/PhysRevD.54.5412 PG 5 WC Astronomy & Astrophysics; Physics, Particles & Fields SC Astronomy & Astrophysics; Physics GA VQ283 UT WOS:A1996VQ28300002 ER PT J AU Jadach, S Placzek, W Skrzypek, M Ward, BFL AF Jadach, S Placzek, W Skrzypek, M Ward, BFL TI Gauge-invariant YFS exponentiation of (un)stable W+W- production at and beyond CERN LEP 2 energies SO PHYSICAL REVIEW D LA English DT Article ID MONTE-CARLO PROGRAM; BHABHA SCATTERING; PAIR PRODUCTION; CROSS-SECTION; SOFT PHOTONS; ANGLES AB We present the theoretical basis and sample Monte Carlo data for the YFS exponentiated calculation of e(+)e(-)-->W+W---> + <(f)over bar (2)f'(2)> at and beyond CERN LEP 2 energies, where the left-handed parts of f(1) and f(i)' are the respective upper and lower components of an SU(2)(L) doublet, i=1,2. The problem of gauge invariance of the radiation from the unstable charged spin 1 W-+/- is solved in an entirely physical manner. Our formulas are illustrated in a prototypical YFS Monte Carlo event generator YFSWW2, wherein both standard model and anomalous triple gauge boson couplings are allowed. C1 CERN,DIV THEORY,CH-1211 GENEVA 23,SWITZERLAND. UNIV TENNESSEE,DEPT PHYS & ASTRON,KNOXVILLE,TN 37996. STANFORD UNIV,SLAC,STANFORD,CA 94309. RP Jadach, S (reprint author), INST PHYS NUCL,ULICA KAWIORY 26A,KRAKOW,POLAND. NR 24 TC 44 Z9 44 U1 0 U2 0 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 0556-2821 J9 PHYS REV D JI Phys. Rev. D PD NOV 1 PY 1996 VL 54 IS 9 BP 5434 EP 5442 DI 10.1103/PhysRevD.54.5434 PG 9 WC Astronomy & Astrophysics; Physics, Particles & Fields SC Astronomy & Astrophysics; Physics GA VQ283 UT WOS:A1996VQ28300004 ER PT J AU Ellis, J Geiger, K Kowalski, H AF Ellis, J Geiger, K Kowalski, H TI Deep-inelastic final states in a space-time description of shower development and hadronization SO PHYSICAL REVIEW D LA English DT Article ID SOFT GLUON INTERFERENCE; MONTE-CARLO SIMULATION; LARGE RAPIDITY GAP; QCD JETS; NUCLEAR COLLISIONS; PERTURBATIVE QCD; HARD PROCESSES; PARTON; SCATTERING; RADIATION AB We extend a quantum kinetic approach to the description of hadronic showers in space, time, and momentum space to deep-inelastic ep collisions, with particular reference to experiments at DESY HERA. We follow the history of hard scattering events back to the initial hadronic state and forward to the formation of color-singlet prehadronic clusters and their decays into hadrons. The time evolution of the spacelike initial-state shower and the timelike secondary partons are treated similarly, and cluster formation is treated using a spatial criterion motivated by confinement and a nonperturbative model for hadronization. We calculate the time evolution of particle distributions in rapidity, transverse, and longitudinal space. We also compare the transverse hadronic energy flow and the distribution of observed hadronic masses with experimental data from HERA, finding encouraging results, and discuss the background to large-rapidity-gap events. The techniques developed in this paper may be applied in the future to more complicated processes such as eA, pp, pA, and AA collisions. C1 BROOKHAVEN NATL LAB,DEPT PHYS,UPTON,NY 11973. DESY,D-22607 HAMBURG,GERMANY. RP Ellis, J (reprint author), CERN,DIV THEORET PHYS,EUROPEAN ORG NUCL RES,CH-1211 GENEVA 23,SWITZERLAND. NR 68 TC 14 Z9 14 U1 0 U2 0 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 0556-2821 J9 PHYS REV D JI Phys. Rev. D PD NOV 1 PY 1996 VL 54 IS 9 BP 5443 EP 5462 DI 10.1103/PhysRevD.54.5443 PG 20 WC Astronomy & Astrophysics; Physics, Particles & Fields SC Astronomy & Astrophysics; Physics GA VQ283 UT WOS:A1996VQ28300005 ER PT J AU Berger, EL Guo, XF Qiu, JW AF Berger, EL Guo, XF Qiu, JW TI Isolated prompt photon production in hadronic final states of e(+)e(-) annihilation SO PHYSICAL REVIEW D LA English DT Article ID LEADING ORDER; CROSS-SECTION; Z(0) DECAYS; QCD; EMISSION; RADIATION; JETS; LEP AB We provide complete analytic expressions for the isolated prompt photon production cross section in e(+)e(-) annihilation reactions through one-loop order in quantum chromodynamics (QCD) perturbation theory. Functional dependences on the isolation cone size delta and isolation energy parameter epsilon are derived. The energy dependence as well as the full angular dependence pf the cross section on theta(gamma) are displayed, where theta(gamma) specifies the direction of the photon with respect to the e(+)e(-) collision axis. We point out that conventional perturbative QCD factorization breaks down for isolated photon production in e(+)e(-) annihilation reactions in a specific region of phase space. We discuss the implications of this breakdown for the extraction of fragmentation functions from e(+)e(-) annihilation data and for computations of prompt photon production in hadron-hadron reactions. C1 IOWA STATE UNIV,DEPT PHYS & ASTRON,AMES,IA 50011. RP Berger, EL (reprint author), ARGONNE NATL LAB,DIV HIGH ENERGY PHYS,ARGONNE,IL 60439, USA. NR 30 TC 21 Z9 21 U1 0 U2 1 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 0556-2821 J9 PHYS REV D JI Phys. Rev. D PD NOV 1 PY 1996 VL 54 IS 9 BP 5470 EP 5495 DI 10.1103/PhysRevD.54.5470 PG 26 WC Astronomy & Astrophysics; Physics, Particles & Fields SC Astronomy & Astrophysics; Physics GA VQ283 UT WOS:A1996VQ28300007 ER PT J AU Baer, H Chen, CH Paige, F Tata, X AF Baer, H Chen, CH Paige, F Tata, X TI Supersymmetry reach of Fermilab Tevatron upgrades: A comparative study SO PHYSICAL REVIEW D LA English DT Article ID TOP-QUARK PRODUCTION; MINIMAL SUPERGRAVITY; ROOT-S=1.8 TEV; COLLIDER; SQUARKS; SIGNALS; SEARCH; GLUINO; COLLISIONS; P(P)OVER-BAR AB We use ISAJET to perform a detailed comparison of the supersymmetry reach of the current Fermilab Tevatron (100 pb(-1)) with that of the Main Injector (2 fb(-1)) and the proposed TeV33 upgrade designed to yield an integrated luminosity of 25 fb(-1). Our analysis is performed within the framework of the minimal supergravity model with gauge coupling unification and radiative electroweak symmetry breaking. For each of these three luminosity options, we delineate the regions of parameter space tr,here jets plus missing energy plus 0, 1, 2 (opposite-sign and same-sign dileptons), and 3 isolated lepton signals from the cascade decays of sparticles should be visible above standard model backgrounds. We compare these with the parameter regions where signals in the clean isolated dilepton and trilepton channels (from chargino or neutralino and slepton production) should be observable. C1 UNIV CALIF DAVIS,DAVIS INST HIGH ENERGY PHYS,DAVIS,CA 95616. BROOKHAVEN NATL LAB,UPTON,NY 11973. UNIV HAWAII,DEPT PHYS & ASTRON,HONOLULU,HI 96822. RP Baer, H (reprint author), FLORIDA STATE UNIV,DEPT PHYS,TALLAHASSEE,FL 32306, USA. NR 51 TC 44 Z9 44 U1 0 U2 0 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 0556-2821 J9 PHYS REV D JI Phys. Rev. D PD NOV 1 PY 1996 VL 54 IS 9 BP 5866 EP 5879 DI 10.1103/PhysRevD.54.5866 PG 14 WC Astronomy & Astrophysics; Physics, Particles & Fields SC Astronomy & Astrophysics; Physics GA VQ283 UT WOS:A1996VQ28300052 ER PT J AU Isgur, N AF Isgur, N TI Exclusive versus inclusive semileptonic (B)over-bar decays in the quark model: Reply SO PHYSICAL REVIEW D LA English DT Letter ID ZWEIG-IIZUKA RULE; MESON DECAYS; HEAVY MESONS; APPROXIMATION AB Some emerging difficulties in the theoretical description of exclusive semileptonic (B) over bar decays are discussed in the context of the quark model. While there are no unambiguous problems at this time, I discuss physics beyond the valence quark model which should eventually be probed by precision measurements of (B) over bar semileptonic decays. RP Isgur, N (reprint author), JEFFERSON LAB,12000 JEFFERSON AVE,NEWPORT NEWS,VA 23606, USA. NR 27 TC 2 Z9 2 U1 0 U2 0 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 0556-2821 J9 PHYS REV D JI Phys. Rev. D PD NOV 1 PY 1996 VL 54 IS 9 BP 5896 EP 5898 DI 10.1103/PhysRevD.54.5896 PG 3 WC Astronomy & Astrophysics; Physics, Particles & Fields SC Astronomy & Astrophysics; Physics GA VQ283 UT WOS:A1996VQ28300058 ER PT J AU Hoover, WG Posch, HA AF Hoover, WG Posch, HA TI Numerical heat conductivity in smooth particle applied mechanics SO PHYSICAL REVIEW E LA English DT Article ID MOLECULAR-DYNAMICS; TEMPERATURE; ALGORITHM; FLOWS AB Smooth particle applied mechanics provides a method or solving the basic equations of continuum mechanics, interpolating these equations onto a grid made up of moving particles. The moving particle grid gives rise to a thoroughly artificial numerical heat conductivity, analogous to the numerical viscosities associated with finite-difference schemes. We exploit an isomorphism linking the smooth-particle method io conventional molecular dynamics, and evaluate this numerical heat conductivity. We find that the corresponding thermal diffusivity is comparable in value to the numerical kinematic viscosity, and that neither is described very well by the Enskog theory. C1 LAWRENCE LIVERMORE NATL LAB,LIVERMORE,CA 94551. UNIV VIENNA,INST EXPT PHYS,A-1090 VIENNA,AUSTRIA. RP Hoover, WG (reprint author), UNIV CALIF DAVIS,DEPT APPL SCI,LIVERMORE,CA 94550, USA. NR 17 TC 18 Z9 18 U1 0 U2 3 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 1063-651X J9 PHYS REV E JI Phys. Rev. E PD NOV PY 1996 VL 54 IS 5 BP 5142 EP 5145 DI 10.1103/PhysRevE.54.5142 PG 4 WC Physics, Fluids & Plasmas; Physics, Mathematical SC Physics GA VU537 UT WOS:A1996VU53700084 ER PT J AU Perry, TS Springer, PT Fields, DF Bach, DR Serduke, FJD Iglesias, CA Rogers, FJ Nash, JK Chen, MH Wilson, BG Goldstein, WH Rozsynai, B Ward, RA Kilkenny, JD Doyas, R DaSilva, LB Back, CA Cauble, R Davidson, SJ Foster, JM Smith, CC BarShalom, A Lee, RW AF Perry, TS Springer, PT Fields, DF Bach, DR Serduke, FJD Iglesias, CA Rogers, FJ Nash, JK Chen, MH Wilson, BG Goldstein, WH Rozsynai, B Ward, RA Kilkenny, JD Doyas, R DaSilva, LB Back, CA Cauble, R Davidson, SJ Foster, JM Smith, CC BarShalom, A Lee, RW TI Absorption experiments on x-ray-heated mid-Z constrained samples SO PHYSICAL REVIEW E LA English DT Article ID SPECTROSCOPY; PLASMA; OPACITY; SPECTRA; FOILS; HOT; GERMANIUM; ALUMINUM; IRON; FLUX AB Results of a niobium absorption experiment are presented that represent a major step in the development of techniques necessary for the quantitative characterization of hot, dense matter. The general requirements for performing quantitative analyses of absorption spectra are discussed. Hydrodynamic simulations are used to illustrate the behavior of tamped x-ray-heated matter and to indicate potential two-dimensional problems inherent in the technique. The absorption spectrum of a low-Z material, in this case aluminum, mixed with niobium provides a temperature diagnostic, which together with radiography as a density diagnostic fully characterizes the sample. A discussion is presented of opacity calculations and a comparison to the measurements is given that illustrates the need for experiments to provide a critical test of theory. The experimental technique is placed in context with a review of previous measurements using absorption spectroscopy to probe hot, dense matter. It is shown that the overall experimental concepts, although understood, were not always achieved in previous experiments. C1 ATOM WEAPONS ESTAB,READING RG7 4PR,BERKS,ENGLAND. SOREQ NUCL RES CTR,IL-81800 YAVNE,ISRAEL. UNIV CALIF BERKELEY,DEPT PHYS,BERKELEY,CA 94720. RP Perry, TS (reprint author), LAWRENCE LIVERMORE NATL LAB,POB 808,LIVERMORE,CA 94550, USA. RI Perry, Theodore/K-3333-2014 OI Perry, Theodore/0000-0002-8832-2033 NR 38 TC 87 Z9 91 U1 2 U2 8 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 1063-651X J9 PHYS REV E JI Phys. Rev. E PD NOV PY 1996 VL 54 IS 5 BP 5617 EP 5631 DI 10.1103/PhysRevE.54.5617 PG 15 WC Physics, Fluids & Plasmas; Physics, Mathematical SC Physics GA VU537 UT WOS:A1996VU53700139 ER PT J AU Turner, L AF Turner, L TI Driven-dissipative Euler's equations for a rigid body: A chaotic system relevant to fluid dynamics SO PHYSICAL REVIEW E LA English DT Article ID TURBULENCE AB Adhering to the lore that vorticity is a critical ingredient af fluid turbulence, a triad of coupled helicity (vorticity) states of the incompressible Navier-Stokes fluid are followed, Effects of the remaining states of the fluid on rile triad are their modeled as a simple driving term. Numerical solution of the equations yield attractors that seems strange and chaotic. This suggests that the unpredictability of nonlinear fluid dynamics (i.e., turbulence) may be traced back to the most primordial structure of the Navier-Stokes equation; namely, the driven triadic interaction. RP Turner, L (reprint author), LOS ALAMOS NATL LAB,DIV THEORET,LOS ALAMOS,NM 87545, USA. NR 11 TC 5 Z9 5 U1 0 U2 0 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 1063-651X J9 PHYS REV E JI Phys. Rev. E PD NOV PY 1996 VL 54 IS 5 BP 5822 EP 5825 DI 10.1103/PhysRevE.54.5822 PG 4 WC Physics, Fluids & Plasmas; Physics, Mathematical SC Physics GA VU537 UT WOS:A1996VU53700162 ER PT J AU Winske, D AF Winske, D TI Regimes of the magnetized Rayleigh-Taylor instability SO PHYSICS OF PLASMAS LA English DT Article ID KELVIN-HELMHOLTZ INSTABILITY; MAGNETOTAIL BARIUM RELEASES; EXPANDING PLASMA CLOUDS; LARGE LARMOR RADIUS; HYDRODYNAMIC INSTABILITIES; HYBRID SIMULATIONS; HEURISTIC MODEL; MAGNETOPAUSE; EVOLUTION; LIMIT AB Hybrid simulations with kinetic ions and massless fluid electrons are used to investigate the linear and nonlinear behavior of the magnetized Rayleigh-Taylor instability in slab geometry with the plasma subject to a constant gravity. Three regimes are found, which are determined by the magnitude of the complex frequency omega = omega(r) + i gamma. For \omega\much less than Omega(i)(Omega(i) = ion gyrofrequency), one finds the typical behavior of the usual fluid regime, namely the development of ''mushroom-head'' spikes and bubbles in the density and a strongly convoluted boundary between the plasma and magnetic field, where the initial gradient is not relaxed much. A second regime, where \omega\similar to 0.1 Omega(i), is characterized by the importance of the Hall term. Linearly, the developing flute modes are more finger-like and tilted along the interface; nonlinearly, clump-like structures form, leading to a significant broadening of the interface. The third regime is characterized by unmagnetized ion behavior, with \omega\similar to Omega(i). Density clumps, rather than flutes, form in the linear stage, while nonlinearly, longer-wavelength modes that resemble those in fluid regime dominate. Finite Larmor radius stabilization of short-wavelength modes is observed in each regime. (C) 1996 American Institute of Physics. RP Winske, D (reprint author), LOS ALAMOS NATL LAB,APPL THEORET & COMPUTAT PHYS DIV,LOS ALAMOS,NM 87545, USA. NR 52 TC 13 Z9 13 U1 0 U2 6 PU AMER INST PHYSICS PI WOODBURY PA CIRCULATION FULFILLMENT DIV, 500 SUNNYSIDE BLVD, WOODBURY, NY 11797-2999 SN 1070-664X J9 PHYS PLASMAS JI Phys. Plasmas PD NOV PY 1996 VL 3 IS 11 BP 3966 EP 3974 DI 10.1063/1.871569 PG 9 WC Physics, Fluids & Plasmas SC Physics GA VT198 UT WOS:A1996VT19800011 ER PT J AU Beer, MA Hammett, GW AF Beer, MA Hammett, GW TI Bounce averaged trapped electron fluid equations for plasma turbulence SO PHYSICS OF PLASMAS LA English DT Article ID TOROIDAL PLASMA; MAGNETIC SHEAR; MODELS AB A novel set of nonlinear fluid equations for mirror-trapped electrons is developed which differs from conventional fluid equations in two main respects: (1) the trapped-fluid moments average over only two of three velocity space dimensions, retaining the full pitch angle dependence of the trapped electron dynamics, and (2) closure approximations include the effects of collisionless wave-particle resonances with the toroidal precession drift. Collisional pitch angle scattering is also included. By speeding up calculations by at least root m(i)/m(e), these bounce averaged fluid equations make possible realistic nonlinear simulations of turbulent particle transport and electron heat transport in tokamaks and other magnetically confined plasmas. (C) 1996 American Institute of Physics. RP Beer, MA (reprint author), PRINCETON UNIV,PLASMA PHYS LAB,PRINCETON,NJ 08543, USA. RI Hammett, Gregory/D-1365-2011 OI Hammett, Gregory/0000-0003-1495-6647 NR 17 TC 43 Z9 43 U1 0 U2 3 PU AMER INST PHYSICS PI WOODBURY PA CIRCULATION FULFILLMENT DIV, 500 SUNNYSIDE BLVD, WOODBURY, NY 11797-2999 SN 1070-664X J9 PHYS PLASMAS JI Phys. Plasmas PD NOV PY 1996 VL 3 IS 11 BP 4018 EP 4022 DI 10.1063/1.871574 PG 5 WC Physics, Fluids & Plasmas SC Physics GA VT198 UT WOS:A1996VT19800016 ER PT J AU Fu, GY Cheng, CZ Budny, R Chang, Z Darrow, DS Fredrickson, E Mazzucato, E Nazikian, R Wong, KL Zweben, S AF Fu, GY Cheng, CZ Budny, R Chang, Z Darrow, DS Fredrickson, E Mazzucato, E Nazikian, R Wong, KL Zweben, S TI Analysis of alpha particle-driven toroidal Alfven eigenmodes in Tokamak Fusion Test Reactor deuterium-tritium experiments SO PHYSICS OF PLASMAS LA English DT Article ID TFTR; EXCITATION; PLASMAS; STABILITY; JT-60U; WAVES; MODES AB The toroidal Alfven eigenmodes (TAE) are calculated to be stable in the presently obtained deuterium-tritium plasmas in the Tokamak Fusion Test Reactor (TFTR) [Plasma Phys. Controlled Nucl. Fusion Res. 26, 11 (1984)]. However, the core localized TAE mode can exist and is less stable than the global TAE modes. The beam ion Landau damping and the radiative damping are the two main stabilizing mechanisms in the present calculation. In future deuterium-tritium experiments, the alpha-driven TAE modes are predicted to occur with a weakly reversed shear profile. (C) 1996 American Institute of Physics. RP Fu, GY (reprint author), PRINCETON UNIV,PRINCETON PLASMA PHYS LAB,POB 451,PRINCETON,NJ 08543, USA. RI Cheng, Chio/K-1005-2014 NR 39 TC 59 Z9 59 U1 1 U2 4 PU AMER INST PHYSICS PI WOODBURY PA CIRCULATION FULFILLMENT DIV, 500 SUNNYSIDE BLVD, WOODBURY, NY 11797-2999 SN 1070-664X J9 PHYS PLASMAS JI Phys. Plasmas PD NOV PY 1996 VL 3 IS 11 BP 4036 EP 4045 DI 10.1063/1.871537 PG 10 WC Physics, Fluids & Plasmas SC Physics GA VT198 UT WOS:A1996VT19800018 ER PT J AU Beer, MA Hammett, GW AF Beer, MA Hammett, GW TI Toroidal gyrofluid equations for simulations of tokamak turbulence SO PHYSICS OF PLASMAS LA English DT Article ID GRADIENT-DRIVEN MODES; LANDAU-FLUID MODELS; GYROKINETIC EQUATIONS; NUMERICAL-SIMULATION; PARTICLE SIMULATION; PLASMAS AB A set of nonlinear gyrofluid equations for simulations of tokamak turbulence are derived by taking moments of the nonlinear toroidal gyrokinetic equation. The moment hierarchy is closed with approximations that model the kinetic effects of parallel Landau damping, toroidal drift resonances, and finite Larmor radius effects. These equations generalize the work of Dorland and Hammett [Phys. Fluids B 5, 812 (1993)] to toroidal geometry by including essential toroidal effects. The closures for phase mixing from toroidal del B and curvature drifts take the basic form presented in Waltz et al. [Phys. Fluids B 4, 3138 (1992)], but here a more rigorous procedure is used, including an extension to higher moments, which provides significantly improved accuracy. In addition, trapped ion effects and collisions are incorporated. This reduced set of nonlinear equations accurately models most of the physics considered important for ion dynamics in core tokamak turbulence, and is simple enough to be used in high resolution direct numerical simulations. (C) 1996 American Institute of Physics. RP Beer, MA (reprint author), PRINCETON UNIV,PLASMA PHYS LAB,PRINCETON,NJ 08543, USA. RI Hammett, Gregory/D-1365-2011 OI Hammett, Gregory/0000-0003-1495-6647 NR 40 TC 120 Z9 120 U1 1 U2 13 PU AMER INST PHYSICS PI WOODBURY PA CIRCULATION FULFILLMENT DIV, 500 SUNNYSIDE BLVD, WOODBURY, NY 11797-2999 SN 1070-664X J9 PHYS PLASMAS JI Phys. Plasmas PD NOV PY 1996 VL 3 IS 11 BP 4046 EP 4064 DI 10.1063/1.871538 PG 19 WC Physics, Fluids & Plasmas SC Physics GA VT198 UT WOS:A1996VT19800019 ER PT J AU Preische, S Efthimion, PC Kaye, SM AF Preische, S Efthimion, PC Kaye, SM TI Radially localized measurements of superthermal electrons using oblique electron cyclotron emission SO PHYSICS OF PLASMAS LA English DT Article ID HYBRID CURRENT DRIVE; SCANNING HETERODYNE RECEIVER; TORE-SUPRA; TOKAMAK; PLASMAS; PROFILE; TRANSMISSION; PERFORMANCE; RADIATION AB It is shown that radial localization of optically thin electron cyclotron emission from superthermal electrons can be imposed by observation of emission upshifted from the thermal cyclotron resonance in the horizontal midplane of a tokamak. A new and unique diagnostic has been proposed and operated to make radially localized measurements of superthermal electrons during lower hybrid current drive on the Princeton Beta Experiment-Modified (PBX-M) tokamak [Bernabei, et al., Phys. Fluids B 5, 2562 (1993)]. The superthermal electron density profile as well as moments of the electron energy distribution as a function of radius are measured during lower hybrid current drive. The time evolution of these measurements after the lower hybrid power is turned off are given and the observed behavior reflects the collisional isotropization of the energy distribution and radial diffusion of the spatial profile. (C) 1996 American Institute of Physics. C1 PRINCETON UNIV,PLASMA PHYS LAB,PRINCETON,NJ 08543. NR 24 TC 11 Z9 11 U1 0 U2 1 PU AMER INST PHYSICS PI WOODBURY PA CIRCULATION FULFILLMENT DIV, 500 SUNNYSIDE BLVD, WOODBURY, NY 11797-2999 SN 1070-664X J9 PHYS PLASMAS JI Phys. Plasmas PD NOV PY 1996 VL 3 IS 11 BP 4065 EP 4073 DI 10.1063/1.871564 PG 9 WC Physics, Fluids & Plasmas SC Physics GA VT198 UT WOS:A1996VT19800020 ER PT J AU Rewoldt, G Lao, LL Tang, WM AF Rewoldt, G Lao, LL Tang, WM TI Microinstability analysis of DIII-D high-performance discharges SO PHYSICS OF PLASMAS LA English DT Article ID MODE DISCHARGES; D TOKAMAK; CONFINEMENT; STABILITY; PLASMAS AB The kinetic stability properties in a number of high performance discharges from the DIII-D tokamak [R. D. Stambaugh for the DIII-D Team, Plasma Physics and Controlled Nuclear Fusion Research, 1994 (International Atomic Energy agency, Vienna, 1995), Vol. 1, p. 83] have been analyzed utilizing a comprehensive kinetic eigenvalue code. The instability considered is the toroidal drift mode [trapped-electron-ion temperature gradient (eta(i)) mode]. This code has been interfaced with equilibria specific to DIII-D plasmas. Experimentally measured kinetic profile data, along with motional stark effect data and external magnetic data was used, and the corresponding magnetohydrodynamic (MHD) equilibria were computed numerically. In particular, a low confinement mode (L-mode) case, a high-l(i) high confinement mode (H-mode) case, a very high confinement mode (VH-mode) case, and a high plasma pressure/poloidal magnetic pressure (beta(p)) case have been analyzed. For the L-mode case, a wide region of instability was found, while for the H-mode and VH-mode and high-beta(p) cases, only relatively narrow regions of instability were found. An assessment of the influence of-velocity-shear how on these instabilities has also been made, as well as of changes in the electron and ion temperature gradients and density gradients. While the experimental values of the sheared toroidal how velocity are not sufficient to stabilize the instability, an increase by a factor of two to four in the how velocity could completely stabilize this mode. (C) 1996 American Institute of Physics. C1 GEN ATOM CO,SAN DIEGO,CA 92186. RP Rewoldt, G (reprint author), PRINCETON UNIV,PLASMA PHYS LAB,PRINCETON,NJ 08543, USA. NR 14 TC 7 Z9 7 U1 0 U2 0 PU AMER INST PHYSICS PI WOODBURY PA CIRCULATION FULFILLMENT DIV, 500 SUNNYSIDE BLVD, WOODBURY, NY 11797-2999 SN 1070-664X J9 PHYS PLASMAS JI Phys. Plasmas PD NOV PY 1996 VL 3 IS 11 BP 4074 EP 4083 DI 10.1063/1.871539 PG 10 WC Physics, Fluids & Plasmas SC Physics GA VT198 UT WOS:A1996VT19800021 ER PT J AU Stotler, DP Skinner, CH Budny, RV Ramsey, AT Ruzic, DN Turkot, RB AF Stotler, DP Skinner, CH Budny, RV Ramsey, AT Ruzic, DN Turkot, RB TI Modeling of neutral hydrogen velocities in the Tokamak Fusion Test Reactor SO PHYSICS OF PLASMAS LA English DT Article ID H-ALPHA; PLASMA; TRANSPORT; DEUTERIUM; TEXTOR; TFTR AB Monte Carlo neutral transport simulations of hydrogen velocities in the Tokamak Fusion Test Reactor (TFTR) [K. M. McGuire et al., Phys. Plasmas 2, 2176 (1995)] are compared with experiment using the Doppler-broadened Balmer-alpha spectral line profile. Good agreement is obtained under a range of conditions, validating the treatment of charge exchange, molecular dissociation, surface reflection, and sputtering in the neutral gas code DEGAS [D. Heifetz et al., J. Comput. Phys. 46, 309 (1982)]. A residual deficiency of 10-100 eV neutrals in most of the simulations indicates that further study of the energetics of H-2(+) dissociation for electron energies in excess of 100 eV is needed. (C) 1996 American Institute of Physics. C1 UNIV ILLINOIS,URBANA,IL 61801. RP Stotler, DP (reprint author), PRINCETON UNIV,PRINCETON PLASMA PHYS LAB,PRINCETON,NJ 08543, USA. RI Stotler, Daren/J-9494-2015 OI Stotler, Daren/0000-0001-5521-8718 NR 51 TC 44 Z9 44 U1 0 U2 2 PU AMER INST PHYSICS PI WOODBURY PA CIRCULATION FULFILLMENT DIV, 500 SUNNYSIDE BLVD, WOODBURY, NY 11797-2999 SN 1070-664X J9 PHYS PLASMAS JI Phys. Plasmas PD NOV PY 1996 VL 3 IS 11 BP 4084 EP 4094 DI 10.1063/1.871540 PG 11 WC Physics, Fluids & Plasmas SC Physics GA VT198 UT WOS:A1996VT19800022 ER PT J AU Carreras, BA Diamond, PH Vetoulis, G AF Carreras, BA Diamond, PH Vetoulis, G TI Role of neutrals in the phase transition model SO PHYSICS OF PLASMAS LA English DT Article ID GRADIENT-DRIVEN TURBULENCE; CONFINEMENT BIFURCATION; POLOIDAL FLOW; TRANSPORT; PARADIGM; DYNAMICS; TOKAMAK AB The phase transition model for the transition from the low-confinement regime (L mode) to high-confinement regime (H mode) is extended to incorporate the effect of the neutral particles on the transition threshold. For usual edge plasma parameters, the increase of effective poloidal viscosity through charge exchange damping and reduction of the effective fluxes by both ionization and charge exchange increases the threshold power required for the transition. For plasmas with the effective energy flux smaller than the convective energy flux, the transition may be triggered by a neutral influx. (C) 1996 American Institute of Physics. C1 UNIV CALIF SAN DIEGO, DEPT PHYS, LA JOLLA, CA 92093 USA. GEN ATOM CO, SAN DIEGO, CA 92186 USA. RP Carreras, BA (reprint author), OAK RIDGE NATL LAB, OAK RIDGE, TN 37831 USA. NR 17 TC 33 Z9 33 U1 0 U2 7 PU AMER INST PHYSICS PI MELVILLE PA CIRCULATION & FULFILLMENT DIV, 2 HUNTINGTON QUADRANGLE, STE 1 N O 1, MELVILLE, NY 11747-4501 USA SN 1070-664X J9 PHYS PLASMAS JI Phys. Plasmas PD NOV PY 1996 VL 3 IS 11 BP 4106 EP 4114 DI 10.1063/1.871543 PG 9 WC Physics, Fluids & Plasmas SC Physics GA VT198 UT WOS:A1996VT19800025 ER PT J AU Amendt, P Murphy, TJ Hatchett, SP AF Amendt, P Murphy, TJ Hatchett, SP TI Novel symmetry tuning in Nova hohlraums using axial gold disks SO PHYSICS OF PLASMAS LA English DT Article ID CONFINEMENT FUSION-TARGETS; NEUTRON; FACILITY; DETECTOR AB A pair of axial gold disks is used to reduce the capsule view of the two laser-entrance-holes in hohlraums irradiated by the Nova laser [E. M. Campbell et al., Rev. Sci. Instrum. 57, 2101 (1986)]. By varying the disk radii a never means of tuning the x-ray drive flux asymmetry is provided. Predicted implosion asymmetry is experimentally validated over a wide range of disk radii. Although simulations suggest increased x-ray drive onto the capsule in the presence of gold disks, neutron-based diagnostics are inconclusive in this regard. (C) 1996 American Institute of Physics. RP Amendt, P (reprint author), LAWRENCE LIVERMORE NATL LAB,LIVERMORE,CA 94550, USA. RI Murphy, Thomas/F-3101-2014 OI Murphy, Thomas/0000-0002-6137-9873 NR 32 TC 11 Z9 11 U1 1 U2 1 PU AMER INST PHYSICS PI WOODBURY PA CIRCULATION FULFILLMENT DIV, 500 SUNNYSIDE BLVD, WOODBURY, NY 11797-2999 SN 1070-664X J9 PHYS PLASMAS JI Phys. Plasmas PD NOV PY 1996 VL 3 IS 11 BP 4166 EP 4171 DI 10.1063/1.871548 PG 6 WC Physics, Fluids & Plasmas SC Physics GA VT198 UT WOS:A1996VT19800031 ER PT J AU Mendel, CW Rosenthal, SE AF Mendel, CW Rosenthal, SE TI Dynamic modeling of magnetically insulated transmission line systems SO PHYSICS OF PLASMAS LA English DT Article ID ELECTRON FLOW AB Negative conductors in vacuum transmission lines used in multiterrawatt applications emit electrons freely. These lines are efficient only because the self-magnetic field of the power flow forces the electrons to flow parallel to the electrodes. Excepting numerical simulations, dynamic modeling of systems of these transmission lines has generally either ignored electron flow, or has included only those electrons that cross immediately to the anode at the front of the forward wave. In this paper we describe an analytic model that includes flowing electrons and the effects of these flows on line voltage and on the reduction of magnetic flux. Axial electron currents are modeled using simple, measurable, and calculable parameters. Transverse electron currents are modeled using general patterns found empirically from simulation data. These currents are in turn related by an expanded set of Telegrapher equations. An example of the use of the model is compared to two-dimensional, time-dependent particle-in-cell simulations. (C) 1996 American Institute of Physics. RP Mendel, CW (reprint author), SANDIA NATL LABS,POB 5800,ALBUQUERQUE,NM 87185, USA. NR 17 TC 28 Z9 32 U1 1 U2 3 PU AMER INST PHYSICS PI WOODBURY PA CIRCULATION FULFILLMENT DIV, 500 SUNNYSIDE BLVD, WOODBURY, NY 11797-2999 SN 1070-664X J9 PHYS PLASMAS JI Phys. Plasmas PD NOV PY 1996 VL 3 IS 11 BP 4207 EP 4219 DI 10.1063/1.871553 PG 13 WC Physics, Fluids & Plasmas SC Physics GA VT198 UT WOS:A1996VT19800036 ER PT J AU Chiu, GS Cohen, SA AF Chiu, GS Cohen, SA TI Comparisons of experimental measurements and two-dimensional plasma-fluid numerical simulations of a magnetized plasma column SO PHYSICS OF PLASMAS LA English DT Article ID PROBES; FIELD; SOL AB The density, the electron, ion, and neutral temperatures in dense (n(e)>10(13) cm(-3)) and cool (T-e<8 eV) magnetized helium plasma columns submerged in a cool neutral gas (n(0) similar to 3X10(15) cm(-3)) environment have been measured. These plasmas, of similar collisionality to those expected in the scrape-off layer of ITER (International Thermonuclear Experimental Reactor) [R. Parker, Contrib. Plasma Phys. 34, 422 (1994)], are found to obey the low-recycling behavior of approximate plasma pressure balance along the column axis. Density decreases by a factor of about 2 and T-e remains isothermal. Computer simulations using the B2 [R. Schneider et al., J. Nucl. Mater. 196-198, 810 (1992)] plasma-fluid code have been performed and are in good agreement with experimental results. Measured ion temperatures are consistent with classical energy transfer from the electrons. Neutrals within the plasma are heated by elastic and charge-exchange collisions. This set of measurements represents the most detailed comparisons between experimental results and B2 predictions. (C) 1996 American Institute of Physics. C1 PRINCETON UNIV,PLASMA PHYS LAB,PRINCETON,NJ 08543. NR 55 TC 3 Z9 3 U1 0 U2 1 PU AMER INST PHYSICS PI WOODBURY PA CIRCULATION FULFILLMENT DIV, 500 SUNNYSIDE BLVD, WOODBURY, NY 11797-2999 SN 1070-664X J9 PHYS PLASMAS JI Phys. Plasmas PD NOV PY 1996 VL 3 IS 11 BP 4250 EP 4267 DI 10.1063/1.871555 PG 18 WC Physics, Fluids & Plasmas SC Physics GA VT198 UT WOS:A1996VT19800041 ER PT J AU Zurek, WH AF Zurek, WH TI Cosmological experiments in condensed matter systems SO PHYSICS REPORTS-REVIEW SECTION OF PHYSICS LETTERS LA English DT Review DE topological defects; superfluids; symmetry breaking dynamics; vortex lines; cosmological phase transitions ID COSMIC STRINGS; INFLATIONARY UNIVERSE; PRESSURE-DEPENDENCE; PHASE-TRANSITIONS; SUPERFLUID HE-3; MONOPOLES; SYMMETRY; FLATNESS; VORTICES; HORIZON AB Topological defects are thought to be left behind by the cosmological phase transitions which occur as the universe expands and cools. Similar processes can be studied in the phase transitions which take place in the laboratory: ''Cosmological'' experiments in superfluid helium and in liquid crystals were carried out within the past few years, and their results shed a new light on the dynamics of the defect-formation process. The aim of this paper is to review the key ideas behind this cosmology-condensed matter connection and to propose new experiments which could probe heretofore unaddressed aspects of the topological defects formation process. RP Zurek, WH (reprint author), LOS ALAMOS NATL LAB, T-6, MS B288, LOS ALAMOS, NM 87545 USA. NR 71 TC 481 Z9 482 U1 4 U2 26 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0370-1573 EI 1873-6270 J9 PHYS REP JI Phys. Rep.-Rev. Sec. Phys. Lett. PD NOV PY 1996 VL 276 IS 4 BP 177 EP 221 DI 10.1016/S0370-1573(96)00009-9 PG 45 WC Physics, Multidisciplinary SC Physics GA VU795 UT WOS:A1996VU79500001 ER PT J AU Reed, T Kramish, A AF Reed, T Kramish, A TI Trinity at Dubna SO PHYSICS TODAY LA English DT Article; Proceedings Paper CT Conference on the History of the Soviet Atomic Project (40s and 50s) CY 1996 CL DUBNA, RUSSIA C1 SCI APPLICAT INT CORP,SAN DIEGO,CA 92121. RP Reed, T (reprint author), LAWRENCE LIVERMORE NATL LAB,LIVERMORE,CA 94550, USA. NR 2 TC 0 Z9 0 U1 0 U2 0 PU AMER INST PHYSICS PI WOODBURY PA CIRCULATION FULFILLMENT DIV, 500 SUNNYSIDE BLVD, WOODBURY, NY 11797-2999 SN 0031-9228 J9 PHYS TODAY JI Phys. Today PD NOV PY 1996 VL 49 IS 11 BP 30 EP 35 DI 10.1063/1.881546 PG 6 WC Physics, Multidisciplinary SC Physics GA VQ892 UT WOS:A1996VQ89200007 ER PT J AU Bond, PD Kahana, SH Millener, DJ AF Bond, PD Kahana, SH Millener, DJ TI Carl Dover - Obituary SO PHYSICS TODAY LA English DT Item About an Individual RP Bond, PD (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 SN 0031-9228 J9 PHYS TODAY JI Phys. Today PD NOV PY 1996 VL 49 IS 11 BP 103 EP 104 DI 10.1063/1.881534 PG 2 WC Physics, Multidisciplinary SC Physics GA VQ892 UT WOS:A1996VQ89200025 ER PT J AU Tuszewski, M Tobin, JA AF Tuszewski, M Tobin, JA TI The accuracy of Langmuir probe ion density measurements in low-frequency RF discharges SO PLASMA SOURCES SCIENCE & TECHNOLOGY LA English DT Article ID GLOW-DISCHARGES; PLASMA AB The ion densities of low-frequency inductively coupled discharges are estimated from Langmuir probe ion saturation currents over a wide range (10(9)-10(12) cm(-3)) of plasma densities. The ion densities are compared to the corresponding electron densities obtained from microwave interferometry. For low plasma densities, the cylindrical probes tend to overestimate the ion densities by factors of up to three. These discrepancies correlate well with RF probe currents and can be reduced with RF compensation or with a symmetrical double probe. For high plasma densities, the ion densities from simple probes without RF compensation agree within 50% with the electron densities from the interferometer. RP Tuszewski, M (reprint author), LOS ALAMOS NATL LAB,POB 1663,LOS ALAMOS,NM 87545, USA. NR 26 TC 39 Z9 40 U1 0 U2 5 PU IOP PUBLISHING LTD PI BRISTOL PA TECHNO HOUSE, REDCLIFFE WAY, BRISTOL, ENGLAND BS1 6NX SN 0963-0252 J9 PLASMA SOURCES SCI T JI Plasma Sources Sci. Technol. PD NOV PY 1996 VL 5 IS 4 BP 640 EP 647 DI 10.1088/0963-0252/5/4/005 PG 8 WC Physics, Fluids & Plasmas SC Physics GA VV852 UT WOS:A1996VV85200005 ER PT J AU Bonivert, WDB Cushnie, G AF Bonivert, WDB Cushnie, G TI Regulatory resources SO PLATING AND SURFACE FINISHING LA English DT Editorial Material C1 CAI ENGN,OAKTON,VA 22124. RP Bonivert, WDB (reprint author), SANDIA NATL LABS,M-S 9404,BOX 969,LIVERMORE,CA 94551, USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU AMER ELECTROPLATERS SOC INC PI ORLANDO PA 12644 RESEARCH PKWY, ORLANDO, FL 32826-3298 SN 0360-3164 J9 PLAT SURF FINISH JI Plat. Surf. Finish. PD NOV PY 1996 VL 83 IS 11 BP 60 EP 62 PG 3 WC Metallurgy & Metallurgical Engineering; Materials Science, Coatings & Films SC Metallurgy & Metallurgical Engineering; Materials Science GA VP366 UT WOS:A1996VP36600017 ER PT J AU Fthenakis, VM Eberspacher, C Moskowitz, PD AF Fthenakis, VM Eberspacher, C Moskowitz, PD TI Recycling strategies to enhance the commercial viability of CIS photovoltaics SO PROGRESS IN PHOTOVOLTAICS LA English DT Article AB Recycling of photovoltaic (PV) modules at the end of their useful life is important for the success of commercializing PV technologies, There are economic, regulatory and technical issues related to recycling; these are addressed here in a case study of recycling CuInSe2 (CIS) PV modules, which is focused on: economics of the use and re-use of materials; regulations on environmental disposal and waste handling logistics and economics of recycling and disposing of products by industries faced with comparable environmental issues; and a workable program of the PV industry of the future, The main conclusions are that there are potential regulatory hurdles but these can be overcome by paying attention to module design elements, In the case of large installations, collection of decommissioned PV modules is feasible with current infrastructure, whereas collection from small remote installations is problematic, Collecting and consolidating used PV modules will be simplified if modules are returned to the manufacturer or to a contracted recycling center as 'products' destined for refurbishment and/or re-use, The projected cost of recycling CIS PV modules ranges from 0 to 0.08 US$ W-1, depending on the specific methods, participants and regulations of recycling. C1 UNISUN,NEWBURY PK,CA 91320. RP Fthenakis, VM (reprint author), BROOKHAVEN NATL LAB,DEPT APPL SCI,BIOMED & ENVIRONM ASSESSMENT GRP,UPTON,NY 11973, USA. NR 4 TC 16 Z9 16 U1 1 U2 3 PU JOHN WILEY & SONS LTD PI W SUSSEX PA BAFFINS LANE CHICHESTER, W SUSSEX, ENGLAND PO19 1UD SN 1062-7995 J9 PROG PHOTOVOLTAICS JI Prog. Photovoltaics PD NOV-DEC PY 1996 VL 4 IS 6 BP 447 EP 456 DI 10.1002/(SICI)1099-159X(199611/12)4:6<447::AID-PIP147>3.0.CO;2-F PG 10 WC Energy & Fuels; Materials Science, Multidisciplinary; Physics, Applied SC Energy & Fuels; Materials Science; Physics GA WD544 UT WOS:A1996WD54400006 ER PT J AU Hart, PJ Nersissian, AM Herrmann, RG Nalbandyan, RM Valentine, JS Eisenberg, D AF Hart, PJ Nersissian, AM Herrmann, RG Nalbandyan, RM Valentine, JS Eisenberg, D TI A missing link in cupredoxins: Crystal structure of cucumber stellacyanin at 1.6 angstrom resolution SO PROTEIN SCIENCE LA English DT Article DE azurin; cucumber basic protein; cupredoxins; glutamine copper ligand; stellacyanin; phytocyanins; plastocyanin; X-ray crystallography ID BLUE-COPPER PROTEINS; AMINO-ACID-SEQUENCE; X-RAY-DIFFRACTION; ELECTRON-TRANSFER; 3-DIMENSIONAL MODEL; POPLAR PLASTOCYANIN; PHOTOSYSTEM-I; SITE; AZURIN; REFINEMENT AB Stellacyanins are blue (type I) copper glycoproteins that differ from other members of the cupredoxin family in their spectroscopic and electron transfer properties. Until now, stellacyanins have eluded structure determination. Here we report the three-dimensional crystal structure of the 109 amino acid, non-glycosylated copper binding domain of recombinant cucumber stellacyanin refined to 1.6 Angstrom resolution. The crystallographic R-value for all 18,488 reflections (sigma > 0) between 50-1.6 Angstrom is 0.195. The overall fold is organized in two beta-sheets, both with four beta-strands. Two alpha-helices are found in loop regions between beta-strands. The beta-sheets form a beta-sandwich similar to those found in other cupredoxins, but some features differ from proteins such as plastocyanin and azurin in that the beta-barrel is more flattened, there is an extra N-terminal alpha-helix, and the copper binding site is much more solvent accessible. The presence of a disulfide bond at the copper binding end of the protein confirms that cucumber stellacyanin has a phytocyanin-like fold. The ligands to copper are two histidines, one cysteine, and one glutamine, the latter replacing the methionine typically found in mononuclear blue copper proteins. The Cu-Gln bond is one of the shortest axial ligand bond distances observed to date in structurally characterized type I copper proteins. The characteristic spectroscopic properties and electron transfer reactivity of stellacyanin, which differ significantly from those of other well-characterized cupredoxins, can be explained by its more exposed copper site, its distinctive amino acid ligand composition, and its nearly tetrahedral ligand geometry. Surface features on the cucumber stellacyanin molecule that could be involved in interactions with putative redox partners are discussed. C1 UNIV CALIF LOS ANGELES,US DOE,LAB STRUCT BIOL & MOL MED,LOS ANGELES,CA 90095. UNIV CALIF LOS ANGELES,DEPT CHEM & BIOCHEM,LOS ANGELES,CA 90095. UNIV MUNICH,INST BOT,D-80638 MUNICH,GERMANY. ARMENIAN ACAD SCI,INST BIOCHEM,YEREVAN 375044,ARMENIA. RI Valentine, Joan/B-6665-2008 OI Valentine, Joan/0000-0002-7174-925X FU NIGMS NIH HHS [GM-28222, GM-31299] NR 52 TC 152 Z9 154 U1 0 U2 4 PU CAMBRIDGE UNIV PRESS PI NEW YORK PA 40 WEST 20TH STREET, NEW YORK, NY 10011-4211 SN 0961-8368 J9 PROTEIN SCI JI Protein Sci. PD NOV PY 1996 VL 5 IS 11 BP 2175 EP 2183 PG 9 WC Biochemistry & Molecular Biology SC Biochemistry & Molecular Biology GA VQ786 UT WOS:A1996VQ78600004 PM 8931136 ER PT J AU Nersissian, AM Mehrabian, ZB Nalbandyan, RM Hart, PJ Fraczkiewicz, G Czernuszewicz, RS Bender, CJ Peisach, J Herrmann, RG Valentine, JS AF Nersissian, AM Mehrabian, ZB Nalbandyan, RM Hart, PJ Fraczkiewicz, G Czernuszewicz, RS Bender, CJ Peisach, J Herrmann, RG Valentine, JS TI Cloning, expression, and spectroscopic characterization of Cucumis sativus stellacyanin in its nonglycosylated form SO PROTEIN SCIENCE LA English DT Article DE blue copper protein; cDNA; Cucumis sativus; expression; inclusion bodies; refolding; spectroscopy; stellacyanin ID BLUE-COPPER PROTEIN; AMINO-ACID-SEQUENCE; RESONANCE RAMAN-SPECTRA; PSEUDOMONAS-AERUGINOSA; ELECTRONIC-STRUCTURE; CRYSTAL-STRUCTURE; AZURIN GENE; PLASTOCYANIN; SITES; IMIDAZOLE AB The cDNA encoding the 182 amino acid long precursor stellacyanin from Cucumis sativus was isolated and characterized. The protein precursor consists of four sequence domains: I, a 23 amino acid hydrophobic N-terminal signal peptide with features characteristic of secretory proteins: II, a 109 amino acid copper-binding domain; III, a 26 amino acid hydroxyproline- and serine-rich peptide characteristic of motifs found in the extensin family, extracellular ar structural glycoproteins found in plant cell walls; and IV, a 22 amino acid hydrophobic extension. Maturation of the protein involves posttranslational processing of domains I and IV. The copper-binding domain (domain II), which shares high sequence identity with other stellacyanins, has been expressed without its carbohydrate attachment sites, refolded from the Escherichia coli inclusion bodies, purified, and characterized by electronic absorption, EPR, ESEEM, and RR spectroscopy. Its spectroscopic properties are nearly identical to those of stellacyanin from the Japanese lacquer tree Rhus vernicifera, the most extensively studied and best characterized stellacyanin, indicating that this domain folds correctly, even in the absence of its carbohydrate moiety. The presence of a hydroxyproline- and serine-rich domain III suggests that stellacyanin may have a function other than that of a diffusible electron transfer protein, conceivably participating in redox reactions localized at the plant cell wall, which are known to occur in response to wounding or infection of the plant. C1 UNIV CALIF LOS ANGELES,DEPT CHEM & BIOCHEM,LOS ANGELES,CA 90095. ARMENIAN ACAD SCI,INST BIOCHEM,YEREVAN 375044,ARMENIA. UNIV CALIF LOS ANGELES,US DOE,LAB STRUCT BIOL & MOL MED,LOS ANGELES,CA 90095. UNIV HOUSTON,DEPT CHEM,HOUSTON,TX 77204. YESHIVA UNIV ALBERT EINSTEIN COLL MED,DEPT PHYSIOL & BIOPHYS,BRONX,NY 10461. UNIV MUNICH,INST BOT,D-80638 MUNICH,GERMANY. RI Valentine, Joan/B-6665-2008 OI Valentine, Joan/0000-0002-7174-925X FU NCRR NIH HHS [RR-02583]; NIGMS NIH HHS [GM-28222, GM-40168] NR 68 TC 34 Z9 34 U1 0 U2 4 PU CAMBRIDGE UNIV PRESS PI NEW YORK PA 40 WEST 20TH STREET, NEW YORK, NY 10011-4211 SN 0961-8368 J9 PROTEIN SCI JI Protein Sci. PD NOV PY 1996 VL 5 IS 11 BP 2184 EP 2192 PG 9 WC Biochemistry & Molecular Biology SC Biochemistry & Molecular Biology GA VQ786 UT WOS:A1996VQ78600005 PM 8931137 ER PT J AU Hinckley, CM Barkan, P AF Hinckley, CM Barkan, P TI Selecting the best defect reduction methodology SO QUALITY AND RELIABILITY ENGINEERING INTERNATIONAL LA English DT Article DE quality; methods; strategy; focus; model; decision; characterization AB Defect rates in the range of 10 parts per million, unimaginable a few years ago, have become the standard of world-class quality. To reduce defects, companies are aggressively implementing various quality methodologies, such as statistical quality control,(1,2) Motorola's six sigma(3) or Shingo's pokayoke.(4,5) 5 Although each quality methodology reduces defects, selection has been based on an intuitive sense without understanding their relative effectiveness in each application. A missing link in developing superior defect reduction strategies has been a lack of a general defect model that clarifies the unique focus of each method. Toward the goal of efficient defect reduction, we have developed an event tree which addresses a broad spectrum of quality factors and two defect sources, namely mistakes and variation. The quality control tree (QCT) predictions are more consistent with production experience than those obtained by the other methodologies considered independently. The QCT demonstrates that world-class defect rates cannot be achieved through focusing on a single defect source or quality control factor, a common weakness of many methodologies. We have shown that the most efficient defect reduction strategy depend on the relative strengths and weaknesses of each organization. The QCT can help each organization identify the most promising defect reduction opportunities for achieving its goals. C1 STANFORD UNIV,DEPT MECH ENGN,STANFORD,CA 94305. RP Hinckley, CM (reprint author), SANDIA NATL LABS,MS 9901,POB 969,LIVERMORE,CA 94551, USA. NR 19 TC 1 Z9 1 U1 0 U2 3 PU JOHN WILEY & SONS LTD PI W SUSSEX PA BAFFINS LANE CHICHESTER, W SUSSEX, ENGLAND PO19 1UD SN 0748-8017 J9 QUAL RELIAB ENG INT JI Qual. Reliab. Eng. Int. PD NOV-DEC PY 1996 VL 12 IS 6 BP 411 EP 420 DI 10.1002/(SICI)1099-1638(199611)12:6<411::AID-QRE53>3.0.CO;2-9 PG 10 WC Engineering, Multidisciplinary; Engineering, Industrial; Operations Research & Management Science SC Engineering; Operations Research & Management Science GA WD895 UT WOS:A1996WD89500003 ER PT J AU Harmon, BA Laird, CE Fishman, GJ Parnell, TA Camp, DC Frederick, CE Hurley, DL Lindstrom, DJ Moss, CE Reedy, RC Reeves, JH Smith, AR Winn, WG Benton, EV AF Harmon, BA Laird, CE Fishman, GJ Parnell, TA Camp, DC Frederick, CE Hurley, DL Lindstrom, DJ Moss, CE Reedy, RC Reeves, JH Smith, AR Winn, WG Benton, EV TI Induced radioactivity of LDEF materials and structural components SO RADIATION MEASUREMENTS LA English DT Article ID SPACECRAFT; BE-7 AB We present an overview of the Long Duration Exposure Facility (LDEF) induced activation measurements. The LDEF, which was gravity-gradient stabilized, was exposed to the low Earth orbit (LEG) radiation environment over a 5.8 year period. Retrieved activation samples and structural components from the spacecraft were analyzed with low and ultra-low background HPGe gamma spectrometry at several national facilities. This allowed a very sensitive measurement of long-lived radionuclides produced by proton- and neutron-induced reactions in the time-dependent, non-isotropic LEO environment. A summary of major findings from this study is given that consists of directionally dependent activation, depth profiles, thermal neutron activation, and surface beryllium-7 deposition from the upper atmosphere. We also describe a database of these measurements that has been prepared for use in testing radiation environmental models and spacecraft design. Published by Elsevier Science Ltd C1 EASTERN KENTUCKY UNIV, DEPT PHYS, RICHMOND, KY 40475 USA. LAWRENCE LIVERMORE NATL LAB, DIV NUCL CHEM, LIVERMORE, CA 94550 USA. TENNESSEE VALLEY AUTHOR, WESTERN AREA RADIOL LAB, MUSCLE SHOALS, AL 35660 USA. UNIV CALIF BERKELEY, LAWRENCE BERKELEY LAB, DIV NUCL SCI, BERKELEY, CA 94720 USA. NASA, LYNDON B JOHNSON SPACE CTR, HOUSTON, TX 77058 USA. LOS ALAMOS NATL LAB, LOS ALAMOS, NM 87545 USA. PACIFIC NW LAB, RICHLAND, WA 99352 USA. WESTINGHOUSE SAVANNAH RIVER CO, AIKEN, SC 29808 USA. UNIV SAN FRANCISCO, PHYS RES LAB, SAN FRANCISCO, CA 94117 USA. RP Harmon, BA (reprint author), NASA, GEORGE C MARSHALL SPACE FLIGHT CTR, HUNTSVILLE, AL 35812 USA. OI Reedy, Robert/0000-0002-2189-1303 NR 48 TC 4 Z9 4 U1 0 U2 2 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD, ENGLAND OX5 1GB SN 1350-4487 J9 RADIAT MEAS JI Radiat. Meas. PD NOV PY 1996 VL 26 IS 6 BP 863 EP 880 DI 10.1016/S1350-4487(96)00094-7 PG 18 WC Nuclear Science & Technology SC Nuclear Science & Technology GA WD818 UT WOS:A1996WD81800016 PM 11540519 ER PT J AU Kudoh, H Celina, M Malone, GM Kaye, RJ Gillen, KT Clough, RL AF Kudoh, H Celina, M Malone, GM Kaye, RJ Gillen, KT Clough, RL TI Pulsed e(-) beam irradiation of polymers - A comparison of dose rate effects and LET effects SO RADIATION PHYSICS AND CHEMISTRY LA English DT Article; Proceedings Paper CT Radiation Chemistry of Polymers Symposium CY DEC, 1995 CL HONOLULU, HI ID GAMMA-RAYS; DEGRADATION; DOSIMETERS; POLYSTYRENE; TEMPERATURE; ELECTRONS; FILMS AB Linear Energy Transfer (LET) effects in radiation chemistry are ascribed to the high density of active species in the track structure, resulting in overlapping of spurs. We studied the possibility of spur overlapping in electron beam irradiation at extremely high dose rate, both theoretically and experimentally. Considering differences in overlap mode leads to the concept of a ''threshold dose rate'', above which spur overlapping may occur, and an ''overlapping dose'', which is necessary to cause overlapping of spurs even at higher dose rate than the threshold, depending on lifetime and effective volume of reactive intermediates. Using Sandia's pulsed power e(-) beam system, we irradiated cellulose triacetate (CTA), polymethylmethacrylate (PMMA), polycarbonate (PC) and high density polyethylene (HDPE) at a dose rate as high as 4 x 10(10) Gy/s at room temperature in the absence of oxygen. Comparison of the e(-) beam results with data obtained from gamma irradiation at 0.5 Gy/s showed no dose rate effects based on discoloration sensitivity for CTA, or on scission probabilities of PMMA and PC. For HDPE, the results indicated a slightly lower rate of gel formation under e(-) beam irradiation, implying that the crosslinking efficiency may be somewhat reduced at the high dose rate. C1 SANDIA NATL LABS,ALBUQUERQUE,NM 87185. RP Kudoh, H (reprint author), JAPAN ATOM ENERGY RES INST,TAKASAKI RADIAT CHEM RES ESTAB,TAKASAKI,GUMMA 37012,JAPAN. NR 29 TC 26 Z9 26 U1 2 U2 8 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD, ENGLAND OX5 1GB J9 RADIAT PHYS CHEM JI Radiat. Phys. Chem. PD NOV PY 1996 VL 48 IS 5 BP 555 EP 562 DI 10.1016/0969-806X(96)00076-X PG 8 WC Chemistry, Physical; Nuclear Science & Technology; Physics, Atomic, Molecular & Chemical SC Chemistry; Nuclear Science & Technology; Physics GA VR111 UT WOS:A1996VR11100006 ER PT J AU Clough, RL Gillen, KT Malone, GM Wallace, JS AF Clough, RL Gillen, KT Malone, GM Wallace, JS TI Color formation in irradiated polymers SO RADIATION PHYSICS AND CHEMISTRY LA English DT Article ID RADIATION; DISCOLORATION; POLYSTYRENE AB Discoloration is a problem in the radiation processing of polymers (such as radiation sterilization), and also in emerging applications in which optical-property materials are used in radiation environments (such as scintillation detectors). We have completed a survey of 17 different types of optical polymers, in which it is found that these materials form both permanent and annealable color centers, but in very different magnitudes and ratios. Optical absorption spectra of irradiated polymers both immediately after irradiation and following different time periods of annealing are provided. Also provided are tables showing rank ordering of the relative resistance of different polymer types to induced discoloration. It is found that the extent of radiation-induced discoloration of polymers has little or no dependence on whether the macromolecule is aromatic or aliphatic, and shows no correlation with the relative extent of radiation-induced mechanical property change. Examples of the influence of stabilizer additives on the extent of discoloration are discussed. RP Clough, RL (reprint author), SANDIA NATL LABS, POB 5800, ALBUQUERQUE, NM 87185 USA. NR 18 TC 38 Z9 39 U1 1 U2 7 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLAND SN 0969-806X J9 RADIAT PHYS CHEM JI Radiat. Phys. Chem. PD NOV PY 1996 VL 48 IS 5 BP 583 EP 594 DI 10.1016/0969-806X(96)00075-8 PG 12 WC Chemistry, Physical; Nuclear Science & Technology; Physics, Atomic, Molecular & Chemical SC Chemistry; Nuclear Science & Technology; Physics GA VR111 UT WOS:A1996VR11100010 ER PT J AU Celina, M Gillen, KT Wise, J Clough, RL AF Celina, M Gillen, KT Wise, J Clough, RL TI Anomalous aging phenomena in a crosslinked polyolefin cable insulation SO RADIATION PHYSICS AND CHEMISTRY LA English DT Article ID THERMALLY AGED ELASTOMERS; OXIDATIVE-DEGRADATION; OXIDIZED POLYOLEFINS; RADIATION; POLYPROPYLENE; POLYETHYLENE; STABILITY; POLYMERS; ENVIRONMENTS; COPOLYMERS AB The radiation-thermal degradation of a commercial crosslinked polyolefin (XLPO) cable insulation material was investigated as a function of dose rate and temperature in the range of 22 - 120 degrees C. Degradative changes in the material were monitored by ultimate elongation, density, gel content, O-2 consumption, infrared spectroscopy, and differential scanning calorimetry. Mechanical aging surprisingly occurred most rapidly at the lowest temperatures. This unusual phenomenon was corroborated by chemical measurements (gel content and density). When samples that had been irradiated at ambient temperature were subsequently annealed at elevated temperatures, recovery of mechanical properties and concurrent changes in gel content and density were observed. The involvement of residual radical species and hydroperoxide intermediates as well as the importance of molecular mobility in the semi-crystalline XLPO as contributors to these anomalous behaviors were evaluated and discussed. The observed inverse temperature effect, where polymer degradation occurs more rapidly at lower temperatures, represents an example in which material aging and life time prediction cannot be handled by conventional approaches, such as the commonly applied Arrhenius methodology. C1 SANDIA NATL LABS, ALBUQUERQUE, NM 87185 USA. NR 55 TC 50 Z9 51 U1 3 U2 15 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLAND SN 0969-806X J9 RADIAT PHYS CHEM JI Radiat. Phys. Chem. PD NOV PY 1996 VL 48 IS 5 BP 613 EP 626 DI 10.1016/0969-806X(96)00083-7 PG 14 WC Chemistry, Physical; Nuclear Science & Technology; Physics, Atomic, Molecular & Chemical SC Chemistry; Nuclear Science & Technology; Physics GA VR111 UT WOS:A1996VR11100014 ER PT J AU Holroyd, RA Chen, PY Stradowska, E Itoh, K AF Holroyd, RA Chen, PY Stradowska, E Itoh, K TI Effect of high pressure on free ion yields for liquids exposed to X-rays SO RADIATION PHYSICS AND CHEMISTRY LA English DT Article ID ELECTRON-MOBILITY AB The effect of pressure on the free ion yield is reported for six nonpolar liquids exposed to X-rays. The free ion yields are determined from the magnitude of the electronic signal following an X-ray pulse. Changes in the free ion yield with pressure are largely uncorrelated with changes in the electron mobility. The mean thermalization range, b, inferred from the free ion yields, decreases with increasing pressure in all liquids, and the product of the range times the density remains quite constant with pressure. C1 UNIV TOKYO,DEPT PURE & APPL SCI,TOKYO 153,JAPAN. RP Holroyd, RA (reprint author), BROOKHAVEN NATL LAB,DEPT CHEM,UPTON,NY 11973, USA. NR 25 TC 2 Z9 2 U1 0 U2 0 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD, ENGLAND OX5 1GB J9 RADIAT PHYS CHEM JI Radiat. Phys. Chem. PD NOV PY 1996 VL 48 IS 5 BP 635 EP 641 DI 10.1016/0969-806X(96)00034-5 PG 7 WC Chemistry, Physical; Nuclear Science & Technology; Physics, Atomic, Molecular & Chemical SC Chemistry; Nuclear Science & Technology; Physics GA VR111 UT WOS:A1996VR11100016 ER PT J AU Nikula, KJ Muggenburg, BA Griffith, WC Carlton, WW Fritz, TE Boecker, BB AF Nikula, KJ Muggenburg, BA Griffith, WC Carlton, WW Fritz, TE Boecker, BB TI Biological effects of (CsCl)-Cs-137 injected in beagle dogs of different ages SO RADIATION RESEARCH LA English DT Article ID RADIATION ACCIDENT AB The toxicity of Cs-137 in the beagle dog was investigated at the Inhalation Toxicology Research Institute (ITRI) and Argonne National Laboratory (ANL) as part of programs to evaluate the biological effects of both radionuclides in atomic bomb fallout and internally deposited fission-product radionuclides. In the ITRI study, young adult dogs were exposed once by intravenous injection to a range of Cs-137 concentrations; the results have recently been published (Nikula et al., Radiat. Res. 142, 347-361, 1995). The purpose of the present report is to summarize the ANL study and to compare the results of the two studies. At ANL, 63 dogs in three age groups (15 juveniles, 142-151 days old; 38 young adults, 388-427 days old; and 10 middle-aged dogs, 1387-2060 days old) were given Cs-137 intravenously at levels (61-162 MBq/kg) near those expected to be lethal within 30 days after injection. There were 17 control dogs from the same colony. Twenty-three of the dogs injected with Cs-137, including all middle-aged dogs, died within 52 days after injection due to hematopoietic cell damage resulting in severe pancytopenia that led to fatal hemorrhage and/or septicemia. The other significant early effect was damage to the germinal epithelium of the seminiferous tubules of all male dogs. These early effects are the same as those reported for the dogs injected with Cs-137 at ITRI. In addition, the design of the ANL study revealed an age- and gender-related differential radiosensitivity for early effects: The middle-aged dogs died significantly earlier due to complications of hematological dyscrasia compared to the juvenile and young adult dogs, and the middle-aged females died significantly earlier than the middle-aged males. The most significant non-neoplastic late effects in the Cs-137-injected dogs from ANL and ITRI were atrophy of the germinal epithelium of seminiferous tubules with azoospermia, and a significant dose-dependent decrease in survival. However, the survival of the ANL dogs was decreased more than that of the ITRI dogs at similar radiation doses from Cs-137. Numerous neoplasms occurred at many different sites in the dogs injected with Cs-137 at ANL and ITRI. Two differences in the findings of the two studies were that (1) there was an increased risk for malignant thyroid neoplasms in the ANL male dogs injected with Cs-137, but not the ITRI dogs of either gender, and (2) there was an increased relative risk for benign neoplasms excluding mammary neoplasms in the ITRI dogs injected with Cs-137, but not the ANL dogs. In both groups, there were dose-related increased incidences of malignant neoplasms, malignant neoplasms excluding mammary neoplasms, all sarcomas considered as a group, all non-mammary carcinomas considered as a group and malignant liver neoplasms. In summary, the similarity of the findings between the two studies and the dose-response relationships for survival and for large groupings of neoplasms suggests that these results are consistent findings in Cs-137-injected dogs and might be dose-related late effects in humans exposed to sufficient amounts of internally deposited Cs-137. (C) 1996 by Radiation Research Society C1 PURDUE UNIV,SCH VET MED,DEPT VET PATHOBIOL,W LAFAYETTE,IN 47907. ARGONNE NATL LAB,CTR MECHANIST BIOL & BIOTECHNOL,ARGONNE,IL 60439. RP Nikula, KJ (reprint author), LOVELACE BIOMED & ENVIRONM RES INST,INHALAT TOXICOL RES INST,POB 5890,ALBUQUERQUE,NM 87185, USA. NR 19 TC 11 Z9 11 U1 0 U2 1 PU RADIATION RESEARCH SOC PI OAK BROOK PA 2021 SPRING RD, STE 600, OAK BROOK, IL 60521 SN 0033-7587 J9 RADIAT RES JI Radiat. Res. PD NOV PY 1996 VL 146 IS 5 BP 536 EP 547 DI 10.2307/3579554 PG 12 WC Biology; Biophysics; Radiology, Nuclear Medicine & Medical Imaging SC Life Sciences & Biomedicine - Other Topics; Biophysics; Radiology, Nuclear Medicine & Medical Imaging GA VQ033 UT WOS:A1996VQ03300007 PM 8896580 ER PT J AU Capala, J Makar, MS Coderre, JA AF Capala, J Makar, MS Coderre, JA TI Accumulation of boron in malignant and normal cells incubated in vitro with boronophenylalanine, mercaptoborane or boric acid SO RADIATION RESEARCH LA English DT Article ID NEUTRON-CAPTURE THERAPY; RELATIVE BIOLOGICAL EFFECTIVENESS; BRAIN-TUMORS; P-BORONOPHENYLALANINE; IN-VITRO; GLIOSARCOMA; GROWTH; SYSTEM; MODEL; B-10 AB The short (<10 mu m) ranges of alpha and Li-7 particles produced during boron neutron capture therapy (BNCT) make the partitioning of the boronated drug within and without the cell of critical importance. The evaluation of the potential usefulness of a boron-containing substance for BNCT requires information about its intracellular accumulation. In the present report, an in vitro method is described for direct measurement of intracellular boron based on rapid centrifugation of cells through a layer of mineral oil and silicon oil to strip away extracellular growth medium. The intracellular concentrations of boronophenylalanine (BPA), mercaptoborane (BSH) and boric acid in malignant cells and in normal cells have been compared. The accumulation ratio is defined as the ratio of the intracellular to the extracellular boron concentration. Boric acid showed an accumulation ratio of 1 while the ratios for BSH and BPA were dependent on cell type and tended to be greater for BPA than for BSH in malignant but not in normal cells. (C) 1996 by Radiation Research Society RP Capala, J (reprint author), BROOKHAVEN NATL LAB,DEPT MED,UPTON,NY 11973, USA. NR 26 TC 42 Z9 43 U1 0 U2 2 PU RADIATION RESEARCH SOC PI OAK BROOK PA 2021 SPRING RD, STE 600, OAK BROOK, IL 60521 SN 0033-7587 J9 RADIAT RES JI Radiat. Res. PD NOV PY 1996 VL 146 IS 5 BP 554 EP 560 DI 10.2307/3579556 PG 7 WC Biology; Biophysics; Radiology, Nuclear Medicine & Medical Imaging SC Life Sciences & Biomedicine - Other Topics; Biophysics; Radiology, Nuclear Medicine & Medical Imaging GA VQ033 UT WOS:A1996VQ03300009 PM 8896582 ER PT J AU McKone, TE AF McKone, TE TI Alternative modeling approaches for contaminant fate in soils: Uncertainty, variability, and reliability SO RELIABILITY ENGINEERING & SYSTEM SAFETY LA English DT Article ID BEHAVIOR ASSESSMENT MODEL; ORGANIC-COMPOUNDS; ALIPHATIC-HYDROCARBONS; RISK ASSESSMENT; TRACE ORGANICS; LAW CONSTANT; WATER; CHEMICALS; FUGACITY; POLLUTANTS AB The fate of contaminants in soils is an issue that is relevant to the management of both uncontrolled hazardous waste sites and to engineered facilities that accept hazardous materials. Addressing long-term potential human exposures requires the use of models. Large uncertainties are associated with predictions from these models. Some of this uncertainty derives from uncertainty about chemical properties and transformation half-lives and some derives from the variation among sites. The purpose of the paper is to consider two alternative modeling approaches and the reliability with which each approach can represent variations of contaminant behavior in the California landscape. One approach is based on the exact solution of the dispersion/advection differential equations that describe contaminant fate in the soil. The second approach is based on a mass-balance approach with less resolution in the soil layers. Incorporation of trichloroethylene (TCE) in the top ten meters of soil is used as a case study to consider how well the two models can be expected to predict cumulative inventory in this ten-meter zone over five years. Using rank correlation as a measure of the importance of parameter uncertainty, it is demonstrated that these two models represent variability of contaminant behavior in the California landscape with comparable reliability. (C) 1996 Elsevier Science Limited. C1 UNIV CALIF BERKELEY,SCH PUBL HLTH,BERKELEY,CA 94720. RP McKone, TE (reprint author), UNIV CALIF BERKELEY,LAWRENCE BERKELEY LAB,BERKELEY,CA 94720, USA. NR 57 TC 45 Z9 45 U1 0 U2 3 PU ELSEVIER SCI LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD, OXON, ENGLAND OX5 1GB SN 0951-8320 J9 RELIAB ENG SYST SAFE JI Reliab. Eng. Syst. Saf. PD NOV-DEC PY 1996 VL 54 IS 2-3 BP 165 EP 181 DI 10.1016/S0951-8320(96)00073-7 PG 17 WC Engineering, Industrial; Operations Research & Management Science SC Engineering; Operations Research & Management Science GA WB789 UT WOS:A1996WB78900008 ER PT J AU Beiersdorfer, P Schweikhard, L LopezUrrutia, JC Widmann, K AF Beiersdorfer, P Schweikhard, L LopezUrrutia, JC Widmann, K TI The magnetic trapping mode of an electron beam ion trap: New opportunities for highly charged ion research SO REVIEW OF SCIENTIFIC INSTRUMENTS LA English DT Article ID LIFETIME MEASUREMENTS; RADIATIVE LIFETIME; STORAGE-RING; LAMB SHIFT; HYDROGENLIKE; TRANSITIONS; STATE; TEMPERATURE; EXCITATION; CAPTURE AB Using x-ray spectroscopic techniques, we have investigated the propel-ties of an electron beam ion trap (EBIT) after the electron beam is switched off. In the absence of the electron beam, bare, and hydrogenlike Kr35+ and Kr36+ ions remain trapped due to externally applied magnetic and electric fields for at least 5 s; xenon ions with an open L shell, i.e., Xe45+-Xe52+, remain trapped at least as long as 20 s. The ion storage time in this ''magnetic trapping mode'' depends on the pressure of background atoms as well as on the value of the externally applied trapping potential, and even longer ion storage times appear possible. The magnetic trapping mode enables a variety of new opportunities for atomic physics research involving highly charged ions, which include the study of charge transfer reactions, Doppler-shift-free measurements of the Lamb shift, measurements of radiative lifetimes of long-lived metastable levels, or ion-ion collision studies, by x-ray or laser spectroscopy, and mass spectrometry. Because the trap is filled in situ during the electron trapping phase, transfer losses associated with filling the trap from an external source are avoided. We present spectra of the K-shell emission from heliumlike and hydrogenlike Kr34+ and Kr35+ as well as Se52+ and Xe53+ that are produced by charge transfer reactions in collisions between ions and neutral atoms. Marked differences with K-shell spectra produced by electron-impact excitation are evident. We use the measurements to infer the Lamb shift contribution to the energy of the 1s(1/2)-2p(3/2) transition in hydrogenlike Xe53+ and determine it to be 31 276(12) eV. The measurement technique can be applied to any ion produced in an EBIT so that Doppler-shift-free Lamb shift measurements of hydrogenlike U91+ are within reach. We also illustrate the utility of the magnetic mode for lifetime determinations by measuring the 3.92(13) ms radiative decay of the 1s2s S-3(1) level in heliumlike N5+. (C) 1996 American Institute of Physics. C1 UNIV MAINZ, INST PHYS, D-55099 MAINZ, GERMANY. RP Beiersdorfer, P (reprint author), LAWRENCE LIVERMORE NATL LAB, DEPT PHYS & SPACE TECHNOL, LIVERMORE, CA 94550 USA. RI Crespo Lopez-Urrutia, Jose R./F-7069-2011 OI Crespo Lopez-Urrutia, Jose R./0000-0002-2937-8037 NR 34 TC 108 Z9 108 U1 1 U2 7 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 NOV PY 1996 VL 67 IS 11 BP 3818 EP 3826 DI 10.1063/1.1147276 PG 9 WC Instruments & Instrumentation; Physics, Applied SC Instruments & Instrumentation; Physics GA VT188 UT WOS:A1996VT18800007 ER PT J AU Alton, GD AF Alton, GD TI Selection of targets and ion sources for radioactive ion beam generation at the Holifield Radioactive Ion Beam Facility SO REVIEW OF SCIENTIFIC INSTRUMENTS LA English DT Article ID ISOTOPE-SEPARATION; ONLINE; EFFICIENCY; RELEASE; DESIGN AB In this article, we describe the performance characteristics for a selected number of target ion sources that will be employed for initial use at the Holifield Radioactive Ion Beam Facility as well as prototype ion sources that show promise for future use for radioactive ion beam applications. A brief review of present efforts to select target materials and to design composite target matrix/heat-sink systems that simultaneously incorporate the short diffusion lengths, high permeabilities, and controllable temperatures required to effect fast and efficient diffusion release of the short-lived species is also given. (C) 1996 American Institute of Physics. RP Alton, GD (reprint author), OAK RIDGE NATL LAB,OAK RIDGE,TN 37831, USA. NR 20 TC 2 Z9 2 U1 0 U2 0 PU AMER INST PHYSICS PI WOODBURY PA CIRCULATION FULFILLMENT DIV, 500 SUNNYSIDE BLVD, WOODBURY, NY 11797-2999 SN 0034-6748 J9 REV SCI INSTRUM JI Rev. Sci. Instrum. PD NOV PY 1996 VL 67 IS 11 BP 3831 EP 3842 DI 10.1063/1.1147284 PG 12 WC Instruments & Instrumentation; Physics, Applied SC Instruments & Instrumentation; Physics GA VT188 UT WOS:A1996VT18800009 ER PT J AU Korszun, ZR Popeanos, M Morano, S Caruso, E Bosshard, H Lara, J AF Korszun, ZR Popeanos, M Morano, S Caruso, E Bosshard, H Lara, J TI Macromolecular neutron crystallography facilities at Brookhaven National Laboratory's high flux beam reactor SO REVIEW OF SCIENTIFIC INSTRUMENTS LA English DT Article AB Neutron crystal diffraction experiments an complementary to x-ray diffraction studies of macromolecules because neutrons are strongly scattered by hydrogen and/or deuterium and can therefore be used to locate these atoms directly in a macromolecule. Since hydrogen atoms constitute about half of the total number of atoms in a macromolecule, and are functionally and structurally important in determining the biological properties of the system, a detailed knowledge of their location can often provide unique information about the system under study. However, because of the relatively low flux (on the order of 10(6) neutrons/s/cm(2)) of neutrons available at the highest flux steady-state reactors, high resolution diffraction experiments require large crystals and long data collection times. Typical crystal volumes exceed a cubic millimeter and data collection times approach three to four months to collect complete data to atomic resolution. Because of these limitations, relatively few high resolution neutron structures have been completed to date. To improve data collection efficiency and throughput, we have redesigned the macromolecular neutron crystallography beam line (H3A) at Brookhaven National Laboratory's high flux beam reactor. In this report, the new facility is described. (C) 1996 American Institute of Physics. RP Korszun, ZR (reprint author), BROOKHAVEN NATL LAB,DEPT BIOL,UPTON,NY 11973, USA. NR 5 TC 0 Z9 0 U1 0 U2 0 PU AMER INST PHYSICS PI WOODBURY PA CIRCULATION FULFILLMENT DIV, 500 SUNNYSIDE BLVD, WOODBURY, NY 11797-2999 SN 0034-6748 J9 REV SCI INSTRUM JI Rev. Sci. Instrum. PD NOV PY 1996 VL 67 IS 11 BP 3843 EP 3846 DI 10.1063/1.1147285 PG 4 WC Instruments & Instrumentation; Physics, Applied SC Instruments & Instrumentation; Physics GA VT188 UT WOS:A1996VT18800010 ER PT J AU delCampo, JG Shapira, D Chavez, E Ortiz, ME Dacal, A DOnofrio, A Terrasi, F AF delCampo, JG Shapira, D Chavez, E Ortiz, ME Dacal, A DOnofrio, A Terrasi, F TI Coincidences between light particles, evaporation residues and complex fragments emitted in the reaction Ni-58+Ni-58 at 500 MeV bombarding energy SO REVISTA MEXICANA DE FISICA LA English DT Article; Proceedings Paper CT XIX Symposium on Nuclear Physics at Oaxtepec CY JAN 03-06, 1996 CL INST MEXICANO DEL SEGURO SOCIAL, CONF CTR, OAXTEPEC, MEXICO SP Univ Nacl Autonoma Mexico, Inst Fis, Univ Nacl Autonoma Mexico, Inst Ciencias Nucl, Consejo Nacl Ciencia & Tecnol, Univ Nacl Autonoma Mexico, Ctr Latinoamericano Fis, Soc Mexicana Fis, Acad Invest Cient, Univ Nacl Autonoma Mexico, Direcc General Asuntos Personal Acad, Inst Politecn Nacl, Consejo Sistema Invest Tecnol, Inst Nacl Invest Nucl HO INST MEXICANO DEL SEGURO SOCIAL, CONF CTR AB Light particles (protons and alphas) were measured in coincidences with complex fragments (4 < Z < 10) and evaporation residues (Z > 40) using the large detector array HILI. A Ni-58 beam of 500 MeV extracted from the HHIRF tandem accelerator was used to bombard a Ni-58 target of 99% enrichment. A good account of the proton and alpha spectra in coincidences with the residues can be achieved only by including in the statistical model calculation the emission of complex fragments and allowing a small emission of a dinuclear configuration formed prior to fusion. The relative kinetic energy spectra between the complex fragments and the residues show a typical coulomb peak consistent with emission from the compound nucleus and the out of plane angular correlation shows that the emission is coplanar. C1 UNIV NACL AUTONOMA MEXICO,INST FIS,MEXICO CITY 01000,DF,MEXICO. UNIV SALERNO,I-84100 SALERNO,ITALY. UNIV NAPLES 2,NAPLES,ITALY. RP delCampo, JG (reprint author), OAK RIDGE NATL LAB,OAK RIDGE,TN 37831, USA. NR 9 TC 2 Z9 2 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 NOV PY 1996 VL 42 SU 1 BP 101 EP 116 PG 16 WC Physics, Multidisciplinary SC Physics GA WE223 UT WOS:A1996WE22300011 ER PT J AU Macchiavelli, AO AF Macchiavelli, AO TI Nuclear structure physics with Gammasphere SO REVISTA MEXICANA DE FISICA LA English DT Article; Proceedings Paper CT XIX Symposium on Nuclear Physics at Oaxtepec CY JAN 03-06, 1996 CL INST MEXICANO DEL SEGURO SOCIAL, CONF CTR, OAXTEPEC, MEXICO SP Univ Nacl Autonoma Mexico, Inst Fis, Univ Nacl Autonoma Mexico, Inst Ciencias Nucl, Consejo Nacl Ciencia & Tecnol, Univ Nacl Autonoma Mexico, Ctr Latinoamericano Fis, Soc Mexicana Fis, Acad Invest Cient, Univ Nacl Autonoma Mexico, Direcc General Asuntos Personal Acad, Inst Politecn Nacl, Consejo Sistema Invest Tecnol, Inst Nacl Invest Nucl HO INST MEXICANO DEL SEGURO SOCIAL, CONF CTR ID SUPERDEFORMED BAND; DELTA-I=4 BIFURCATION; SYMMETRY; SPIN AB The increase in sensitivity of the new generation of gamma-ray arrays is discussed and some recent results obtained with Gammasphere are presented. These include the observation of linking transitions between superdeformed and normal deformed states in Hg-194, Delta I = 2 staggering, lifetime measurements and the use of deep-inelastic reactions as a gamma-ray spectroscopy tool. RP Macchiavelli, AO (reprint author), UNIV CALIF BERKELEY,LAWRENCE BERKELEY LAB,DIV NUCL SCI,1 CYCLOTRON RD,BERKELEY,CA 94720, USA. NR 28 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 NOV PY 1996 VL 42 SU 1 BP 175 EP 187 PG 13 WC Physics, Multidisciplinary SC Physics GA WE223 UT WOS:A1996WE22300017 ER PT J AU Madani, H ChavezLomeli, E Dacal, A Ortiz, ME Suro, J delCampo, JG McConnell, J Shapira, D AF Madani, H ChavezLomeli, E Dacal, A Ortiz, ME Suro, J delCampo, JG McConnell, J Shapira, D TI A first look at the Kr-84(1260 MeV)+Al-27 data using the heavy ion light ion detector SO REVISTA MEXICANA DE FISICA LA English DT Article; Proceedings Paper CT XIX Symposium on Nuclear Physics at Oaxtepec CY JAN 03-06, 1996 CL INST MEXICANO DEL SEGURO SOCIAL, CONF CTR, OAXTEPEC, MEXICO SP Univ Nacl Autonoma Mexico, Inst Fis, Univ Nacl Autonoma Mexico, Inst Ciencias Nucl, Consejo Nacl Ciencia & Tecnol, Univ Nacl Autonoma Mexico, Ctr Latinoamericano Fis, Soc Mexicana Fis, Acad Invest Cient, Univ Nacl Autonoma Mexico, Direcc General Asuntos Personal Acad, Inst Politecn Nacl, Consejo Sistema Invest Tecnol, Inst Nacl Invest Nucl HO INST MEXICANO DEL SEGURO SOCIAL, CONF CTR ID MEV NUCLEON; COLLISIONS; FRAGMENTS AB Evaporation residues obtained with the 1260-MeV Kr-84 + Al-27 reaction were measured in coincidence with light particles (protons and alphas), using the HILI detector array. The energy spectra of the evaporation residues and light particles in coincidence are compared to the predictions of the statistical decay code LILITA. Data on intermediate mass fragments which are abundantly produced in this reaction are also reported, and compared to a modified version of LILITA. C1 OAK RIDGE NATL LAB,OAK RIDGE,TN 37831. RP Madani, H (reprint author), UNIV NACL AUTONOMA MEXICO,INST FIS,APARTADO POSTAL 20-364,MEXICO CITY 01000,DF,MEXICO. NR 13 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 NOV PY 1996 VL 42 SU 1 BP 188 EP 197 PG 10 WC Physics, Multidisciplinary SC Physics GA WE223 UT WOS:A1996WE22300018 ER PT J AU Sun, Y Zhang, JY Guidry, M Feng, DH AF Sun, Y Zhang, JY Guidry, M Feng, DH TI The projected shell model and its newest applications to high-spin spectroscopy SO REVISTA MEXICANA DE FISICA LA English DT Article; Proceedings Paper CT XIX Symposium on Nuclear Physics at Oaxtepec CY JAN 03-06, 1996 CL INST MEXICANO DEL SEGURO SOCIAL, CONF CTR, OAXTEPEC, MEXICO SP Univ Nacl Autonoma Mexico, Inst Fis, Univ Nacl Autonoma Mexico, Inst Ciencias Nucl, Consejo Nacl Ciencia & Tecnol, Univ Nacl Autonoma Mexico, Ctr Latinoamericano Fis, Soc Mexicana Fis, Acad Invest Cient, Univ Nacl Autonoma Mexico, Direcc General Asuntos Personal Acad, Inst Politecn Nacl, Consejo Sistema Invest Tecnol, Inst Nacl Invest Nucl HO INST MEXICANO DEL SEGURO SOCIAL, CONF CTR ID SUPERDEFORMED BAND; DELTA-I=4 BIFURCATION; NUCLEI; ALIGNMENT; SYMMETRY; STATES; REGION; CE-131 AB The Projected Shell Model is a shell model developed for medium to heavy nuclear systems. It was primarily designed to study nuclear structure of high-spin states in normally deformed systems, and has recently been generalized to describe superdeformed bands. The model is expected to be a powerful tool for studying the physics related to the new gamma-ray detectors, such as Gammasphere, Eurogam, and GASP. A general introduction to the model is given and three topics are discussed: 1) A systematic calculation and a statistical comparison with the cranked shell model in treating rotational nuclei; 2) Application to superdeformed bands; 3) The potential existence of Delta I = 4 bifurcation in the PSM. C1 UNIV TENNESSEE,DEPT PHYS,KNOXVILLE,TN 37996. OAK RIDGE NATL LAB,DIV PHYS,OAK RIDGE,TN 37831. DREXEL UNIV,DEPT PHYS & ATMOSPHER SCI,PHILADELPHIA,PA 19104. RP Sun, Y (reprint author), OAK RIDGE NATL LAB,JOINT INST HEAVY ION RES,OAK RIDGE,TN 37831, USA. NR 34 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 NOV PY 1996 VL 42 SU 1 BP 227 EP 242 PG 16 WC Physics, Multidisciplinary SC Physics GA WE223 UT WOS:A1996WE22300022 ER PT J AU Strenn, S Hsia, TC Wilhelmsen, K AF Strenn, S Hsia, TC Wilhelmsen, K TI A segmentation algorithm for collision avoidance in telerobotics applications SO ROBOTICA LA English DT Article DE telerobotics; collision avoidance; segmentation algorithm; real-time AB This paper proposes a new algorithm, known as the Segmentation Algorithm, which provides model-based, real-time, whole-arm collision avoidance for telerobotic applications. The work presented here is an extension and modification of potential field theory. Novel aspects of the algorithm include the application of a hierarchical segmentation technique to minimize on-line processing and the development of procedures which account for workspace object translation, rotation, and grasping. The SA outputs torques, which, when applied to the control arm, prevent the teleoperator from driving the remote arm into a collision. The teleoperator actually feels workspace objects that are spatially close to the remote arm - an experience known as virtual force-reflection. The SA's performance has been analyzed in terms of its speed and efficiency vis a vis various system parameters, including workspace object distribution, size, and number. Simulation results show that the SA succeeds in providing real-time collision avoidance where less elegant brute force algorithms fail. C1 UNIV CALIF DAVIS,DEPT ECE,DAVIS,CA 95616. LAWRENCE LIVERMORE NATL LAB,LIVERMORE,CA 94550. RP Strenn, S (reprint author), SANTA BARBARA RES CTR,GOLETA,CA 93117, USA. NR 12 TC 0 Z9 0 U1 0 U2 0 PU CAMBRIDGE UNIV PRESS PI NEW YORK PA 40 WEST 20TH STREET, NEW YORK, NY 10011-4211 SN 0263-5747 J9 ROBOTICA JI Robotica PD NOV-DEC PY 1996 VL 14 BP 603 EP 610 PN 6 PG 8 WC Robotics SC Robotics GA WB381 UT WOS:A1996WB38100012 ER PT J AU Joy, DC Joy, CS Bunn, RD AF Joy, DC Joy, CS Bunn, RD TI Measuring the performance of scanning electron microscope detectors SO SCANNING LA English DT Article DE ET detectors; Robinson detector; microchannel plate detector AB A simple digital method of measuring the performance of detectors in the scanning electron microscope (SEM) is described. The value derived is absolute and can therefore be used to compare both different detectors on the same instrument as well as different detectors on different instruments. The technique can be applied to secondary electron, backscattered electron, and energy-dispersive x-ray detectors. Examples are given of measurements made on a variety of commercial detectors installed on a number of current SEMs. C1 OAK RIDGE NATL LAB,OAK RIDGE,TN 37831. RP Joy, DC (reprint author), UNIV TENNESSEE,DEPT BIOCHEM CELLULAR & MOL BIOL,EM FACIL,KNOXVILLE,TN 37996, USA. NR 8 TC 29 Z9 29 U1 0 U2 6 PU FAMS INC PI MAHWAH PA BOX 832, MAHWAH, NJ 07430 SN 0161-0457 J9 SCANNING JI Scanning PD NOV PY 1996 VL 18 IS 8 BP 533 EP 538 PG 6 WC Instruments & Instrumentation; Microscopy SC Instruments & Instrumentation; Microscopy GA VV767 UT WOS:A1996VV76700001 PM 8946770 ER PT J AU Wu, DXY Lee, CYC Widdicombe, JH Bastacky, J AF Wu, DXY Lee, CYC Widdicombe, JH Bastacky, J TI Ultrastructure of tracheal surface liquid: Low-temperature scanning electron microscopy SO SCANNING LA English DT Article DE mucus; cryopreservation; low-temperature scanning electron microscopy; airway surface liquid ID EPITHELIUM; LUNG AB A layer of liquid lines the airways in the lung. Previous microscopic studies have suggested that it is in two phases, with a mucous gel lying above a periciliary sol. However, shrinkage artifacts due to chemical fixation, dehydration, and drying have prevented reliable estimates of the depth of these layers. To avoid such problems, we have studied the surface liquid of bovine trachea by low-temperature scanning electron microscopy (LTSEM). A polished copper probe cooled to liquid nitrogen temperature was applied to the mucosal surface of sheets of excised tracheal epithelium to effect rapid freezing of surface liquid. Tissue sheets were then mounted in an LTSEM (AMRay 1000A with Biochamber) which maintains samples at -180 degrees C with a Joule-Thompson refrigerator built into the stage. Tissues were fractured at right angles to the epithelial surface, coated with gold, and viewed, all at 10(-5) to 10(-6) ton: without transfer through air. The sample was stable under the electron beam at accelerating voltages up to 20 kV. Epithelial features (nuclei, cilia, microvilli, mucous granules) were well preserved. The mucosal surface of the cells was covered with material on the order of 8 mu m in depth. The mucous gel and periciliary sol could be seen as distinct layers and could be distinguished by the size and pattern of ice crystal voids generated by radiant-etching of the fractured surface of the sample. C1 CHILDRENS HOSP,OAKLAND RES INST,OAKLAND,CA 94609. UNIV CALIF BERKELEY,LAWRENCE BERKELEY LAB,BERKELEY,CA 94720. UNIV CALIF SAN FRANCISCO,CARDIOVASC RES INST,SAN FRANCISCO,CA 94143. FU NHLBI NIH HHS [HL 42368, HL52161] NR 17 TC 11 Z9 11 U1 0 U2 2 PU FAMS INC PI MAHWAH PA BOX 832, MAHWAH, NJ 07430 SN 0161-0457 J9 SCANNING JI Scanning PD NOV PY 1996 VL 18 IS 8 BP 589 EP 592 PG 4 WC Instruments & Instrumentation; Microscopy SC Instruments & Instrumentation; Microscopy GA VV767 UT WOS:A1996VV76700008 PM 8946773 ER PT J AU Benson, LV Burdett, JW Kashgarian, M Lund, SP Phillips, FM Rye, RO AF Benson, LV Burdett, JW Kashgarian, M Lund, SP Phillips, FM Rye, RO TI Climatic and hydrologic oscillations in the Owens Lake basin and adjacent Sierra Nevada, California SO SCIENCE LA English DT Article ID LATE PLEISTOCENE GLACIATION; SURFACE-WATER SYSTEM; NORTH-ATLANTIC; HEINRICH EVENTS; ICEBERG DISCHARGES; STABLE ISOTOPES; PYRAMID LAKE; OXYGEN; SEDIMENTS; HYDROGEN AB Oxygen isotope and total inorganic carbon values of cored sediments from the Owens Lake basin, California, indicate that Owens Lake overflowed most of the time between 52,500 and 12,500 carbon-14 (C-14) years before present (B.P.). Owens Lake desiccated during or after Heinrich event H1 and was hydrologically closed during Heinrich event H2. The magnetic susceptibility and organic carbon content of cored sediments indicate that about 19 Sierra Nevada glaciations occurred between 52,500 and 23,500 C-14 years B.P. Most of the glacial advances were accompanied by decreases in the amount of discharge reaching Owens Lake. Comparison of the timing of glaciation with the lithic record of North Atlantic core V23-81 indicates that the number of mountain glacial cycles and the number of North Atlantic lithic events were about equal between 39,000 and 23,500 C-14 years B.P. C1 US GEOL SURVEY,DENVER FED CTR,LAKEWOOD,CO 80225. LAWRENCE LIVERMORE NATL LAB,LIVERMORE,CA 94550. UNIV SO CALIF,DEPT EARTH SCI,LOS ANGELES,CA 90089. NEW MEXICO INST MIN & TECHNOL,DEPT EARTH & ENVIRONM SCI,SOCORRO,NM 87801. RP Benson, LV (reprint author), US GEOL SURVEY,3215 MARINE ST,BOULDER,CO 80303, USA. RI Kashgarian, Michaele/E-1665-2011 OI Kashgarian, Michaele/0000-0001-7824-8418 NR 34 TC 113 Z9 119 U1 2 U2 21 PU AMER ASSOC ADVANCEMENT SCIENCE PI WASHINGTON PA 1200 NEW YORK AVE, NW, WASHINGTON, DC 20005 SN 0036-8075 J9 SCIENCE JI Science PD NOV 1 PY 1996 VL 274 IS 5288 BP 746 EP 749 DI 10.1126/science.274.5288.746 PG 4 WC Multidisciplinary Sciences SC Science & Technology - Other Topics GA VQ145 UT WOS:A1996VQ14500031 ER PT J AU Norton, DP Goyal, A Budai, JD Christen, DK Kroeger, DM Specht, ED He, Q Saffian, B Paranthaman, M Klabunde, CE Lee, DF Sales, BC List, FA AF Norton, DP Goyal, A Budai, JD Christen, DK Kroeger, DM Specht, ED He, Q Saffian, B Paranthaman, M Klabunde, CE Lee, DF Sales, BC List, FA TI Epitaxial YBa2Cu3O7 on biaxially textured nickel (001): An approach to superconducting tapes with high critical current density SO SCIENCE LA English DT Article ID TRANSPORT CRITICAL-CURRENT; GRAIN-BOUNDARY JUNCTIONS; THIN-FILMS; BUFFER LAYERS; LASER DEPOSITION; GROWTH; ZIRCONIA; BEHAVIOR; FIELDS AB In-plane-aligned, c axis-oriented YBa2Cu3O7 (YBCO) films with superconducting critical current densities J(c) as high as 700,000 amperes per square centimeter at 77 kelvin have been grown on thermomechanically rolled-textured nickel (001) tapes by pulsed-laser deposition. Epitaxial growth of oxide buffer layers directly on biaxially textured nickel, formed by recrystallization of cold-rolled pure nickel, made possible the growth of YBCO films 1.5 micrometers thick with superconducting properties that are comparable to those observed for epitaxial films on single-crystal oxide substrates. This result represents a viable approach for the production of long superconducting tapes for high-current, high-field applications at 77 kelvin. C1 OAK RIDGE NATL LAB,DIV MET & CERAM,OAK RIDGE,TN 37831. OAK RIDGE NATL LAB,DIV CHEM & ANALYT SCI,OAK RIDGE,TN 37831. RP Norton, DP (reprint author), OAK RIDGE NATL LAB,DIV SOLID STATE,POB 2008,OAK RIDGE,TN 37831, USA. RI Christen, David/A-9709-2008; Specht, Eliot/A-5654-2009; Paranthaman, Mariappan/N-3866-2015; Budai, John/R-9276-2016 OI Specht, Eliot/0000-0002-3191-2163; Paranthaman, Mariappan/0000-0003-3009-8531; Budai, John/0000-0002-7444-1306 NR 31 TC 602 Z9 632 U1 10 U2 90 PU AMER ASSOC ADVANCEMENT SCIENCE PI WASHINGTON PA 1200 NEW YORK AVE, NW, WASHINGTON, DC 20005 SN 0036-8075 J9 SCIENCE JI Science PD NOV 1 PY 1996 VL 274 IS 5288 BP 755 EP 757 DI 10.1126/science.274.5288.755 PG 3 WC Multidisciplinary Sciences SC Science & Technology - Other Topics GA VQ145 UT WOS:A1996VQ14500034 ER PT J AU Du, GT Stair, KA Devane, G Zhang, JP Chang, RPH White, CW Li, XM Wang, ZL Liu, Y AF Du, GT Stair, KA Devane, G Zhang, JP Chang, RPH White, CW Li, XM Wang, ZL Liu, Y TI Vertical-cavity surface-emitting laser with a thin metal mirror fabricated by double implantation using a tungsten wire mask SO SEMICONDUCTOR SCIENCE AND TECHNOLOGY LA English DT Article AB We have devised a novel vertical-cavity surface-emitting laser structure. The epitaxial layers have been grown by molecular beam epitaxy (MBE). The bottom mirror consists of 30.5 pairs of Al0.3Ga0.9As/AlAs multilayer distributed Bragg reflector (DBR). The top mirror is a hybrid reflector consisting of 8.5 pairs of Al0.1Ga0.9As/AlAs multilayer and a semi-transparent metal film. The structure is obtained by two He ion implantations using tungsten wires as an implant mask. The lowest threshold current is 8.2 mA, and the highest peak tight output power is 1.8 mW under room-temperature cw conditions. C1 OAK RIDGE NATL LAB,DIV SOLID STATE,OAK RIDGE,TN 37831. JILIN UNIV,DEPT ELECT ENGN,CHENGDU 130023,PEOPLES R CHINA. JILIN UNIV,STATE KEY LAB INTEGRATED OPTOELECT,CHENGDU 130023,PEOPLES R CHINA. RP Du, GT (reprint author), NORTHWESTERN UNIV,EVANSTON,IL 60208, USA. RI Stair, Kathleen/B-7534-2009; Chang, R.P.H/B-7505-2009; Wang, Zhong Lin/E-2176-2011 OI Wang, Zhong Lin/0000-0002-5530-0380 NR 6 TC 3 Z9 3 U1 0 U2 1 PU IOP PUBLISHING LTD PI BRISTOL PA TECHNO HOUSE, REDCLIFFE WAY, BRISTOL, ENGLAND BS1 6NX SN 0268-1242 J9 SEMICOND SCI TECH JI Semicond. Sci. Technol. PD NOV PY 1996 VL 11 IS 11 BP 1734 EP 1736 DI 10.1088/0268-1242/11/11/015 PG 3 WC Engineering, Electrical & Electronic; Materials Science, Multidisciplinary; Physics, Condensed Matter SC Engineering; Materials Science; Physics GA VU749 UT WOS:A1996VU74900015 ER PT J AU Hughes, KL Miller, SL Rodriguez, JL McWhorter, PJ AF Hughes, KL Miller, SL Rodriguez, JL McWhorter, PJ TI Calibration of an integrated hydrogen gas-sensing system SO SENSORS AND ACTUATORS B-CHEMICAL LA English DT Article DE hydrogen gas sensors; integrated sensors ID PALLADIUM; ALLOYS; ABSORPTION AB An accurate and flexible calibration model has been developed for a single-chip integrated hydrogen-sensing system. The model continuously provides the hydrogen concentration from measurements of the palladium-nickel film resistor, which serves as the active gas-sensing structure, and an on-chip thermometer. Calibration parameters are easily determined from simple measurements that utilize temperature control provided by on-chip heaters. The model is shown to yield accurate results in practical environments, i.e., where time-dependent temperatures and hydrogen concentrations coexist. The model enables the implementation of small practical hydrogen-sensing systems based on an integrated hydrogen-sensing chip. C1 SANDIA NATL LABS,ALBUQUERQUE,NM 87185. RP Hughes, KL (reprint author), UNIV NEW MEXICO,DEPT ELECT & COMP ENGN,ALBUQUERQUE,NM 87131, USA. NR 18 TC 2 Z9 2 U1 0 U2 1 PU ELSEVIER SCIENCE SA LAUSANNE PI LAUSANNE PA PO BOX 564, 1001 LAUSANNE, SWITZERLAND SN 0925-4005 J9 SENSOR ACTUAT B-CHEM JI Sens. Actuator B-Chem. PD NOV PY 1996 VL 37 IS 1-2 BP 75 EP 81 DI 10.1016/S0925-4005(97)80074-3 PG 7 WC Chemistry, Analytical; Electrochemistry; Instruments & Instrumentation SC Chemistry; Electrochemistry; Instruments & Instrumentation GA WJ776 UT WOS:A1996WJ77600012 ER PT J AU Manteuffel, T McCormick, S Morel, J Yang, G AF Manteuffel, T McCormick, S Morel, J Yang, G TI A fast multigrid algorithm for isotropic transport problems .2. With absorption SO SIAM JOURNAL ON SCIENTIFIC COMPUTING LA English DT Article DE multigrid; particle transport ID SN EQUATIONS; SCATTERING AB A multigrid method for solving the one-dimensional slab-geometry S-N equations with isotropic scattering and absorption is presented. The case with no absorption was treated in part I of this paper [Manteuffel, McCormick, Morel, Oliveira, and Yang, SIAM J. Sci. Comput., 16 (1995), pp. 601-635]. Relaxation is based on a two-cell inversion, which is very efficient because it takes advantage of the structure of the two-cell problem. For interpolation we use kinked linear elements. The kink is based on the amount of absorption present. The restriction operator is full weighting. Numerical results show this algorithm to be faster than diffusion synthetic acceleration (DSA) in all regimes. This scheme is also well suited for massively parallel computer architectures. C1 LOS ALAMOS NATL LAB, COMP RES GRP C3, LOS ALAMOS, NM 87545 USA. UNIV COLORADO, CTR COMPUTAT MATH, DENVER, CO 80217 USA. RP UNIV COLORADO, PROGRAM APPL MATH, BOULDER, CO 80309 USA. NR 15 TC 8 Z9 8 U1 0 U2 0 PU SIAM PUBLICATIONS PI PHILADELPHIA PA 3600 UNIV CITY SCIENCE CENTER, PHILADELPHIA, PA 19104-2688 USA SN 1064-8275 EI 1095-7197 J9 SIAM J SCI COMPUT JI SIAM J. Sci. Comput. PD NOV PY 1996 VL 17 IS 6 BP 1449 EP 1474 DI 10.1137/S1064827593251435 PG 26 WC Mathematics, Applied SC Mathematics GA VP024 UT WOS:A1996VP02400009 ER PT J AU Farhar, BC AF Farhar, BC TI Energy and world history - Smil,V SO SOCIETY & NATURAL RESOURCES LA English DT Book Review RP Farhar, BC (reprint author), NATL RENEWABLE ENERGY LAB,GOLDEN,CO, USA. NR 1 TC 0 Z9 0 U1 0 U2 1 PU TAYLOR & FRANCIS PI BRISTOL PA 1900 FROST ROAD, SUITE 101, BRISTOL, PA 19007-1598 SN 0894-1920 J9 SOC NATUR RESOUR JI Soc. Nat. Resour. PD NOV-DEC PY 1996 VL 9 IS 6 BP 655 EP 658 DI 10.1080/08941929609381003 PG 4 WC Environmental Studies; Planning & Development; Sociology SC Environmental Sciences & Ecology; Public Administration; Sociology GA VY372 UT WOS:A1996VY37200009 ER PT J AU ElFarhan, YH Petersen, LW Rolston, DE Glauz, RD AF ElFarhan, YH Petersen, LW Rolston, DE Glauz, RD TI Analytical solution for two-region diffusion with two well-mixed end chambers SO SOIL SCIENCE SOCIETY OF AMERICA JOURNAL LA English DT Article AB Many methods have been developed for determining the effective gaseous diffusion coefficient (D-p) in soils. Some commonly used methods are the one- and two-chamber apparatuses. In addition, laboratory apparatuses for the study of vapor diffusion, sorption, and biodegradation may consist of soil and vapor chambers. Existing analytical solutions for such apparatuses cannot accommodate diffusion through regions containing two distinct layers of differing porosity and diffusion coefficient, Such dual porosities can represent stagnant air layers, or crusting-compaction at core ends. We developed an analytical solution for gaseous diffusion in a four-region chamber system. The system consists of two diffusion regions (with two different porosities), and a well-mixed end chamber attached at either end. The solution was used to simulate one-dimensional gas diffusion in an apparatus consisting of two diffusion regions with constant-concentration boundary conditions. The solution was also used to quantify errors made in estimating D-p using the one-chamber apparatus when the air chamber is not mixed, or when a stagnant air layer exists above the soil surface, Errors due to non-mixing decreased with time and increased with water content and air-chamber size when analysis was done using concentrations at a point close to the soil surface. Analysis of the effects of a stagnant air layer showed that errors increased with time and air-chamber size and decreased with increasing water content. Analysis done to test the effects of soil crusting on diffusion showed that, despite the thinness of the soil crust, large estimation errors in D-p are possible. C1 DANISH MINIST AGR,DEPT PLANT & SOIL SCI,RES CTR FOULUM,DK-8830 TJELE,DENMARK. LAWRENCE LIVERMORE NATL LAB,DEPT MATH,DAVIS,CA 95616. RP ElFarhan, YH (reprint author), LAWRENCE LIVERMORE NATL LAB,DEPT LAND AIR & WATER RESOURCES,DAVIS,CA 95616, USA. RI de Jonge, Lis/E-9757-2016 OI de Jonge, Lis/0000-0003-2874-0644 NR 10 TC 2 Z9 2 U1 0 U2 4 PU SOIL SCI SOC AMER PI MADISON PA 677 SOUTH SEGOE ROAD, MADISON, WI 53711 SN 0361-5995 J9 SOIL SCI SOC AM J JI Soil Sci. Soc. Am. J. PD NOV-DEC PY 1996 VL 60 IS 6 BP 1697 EP 1704 PG 8 WC Soil Science SC Agriculture GA WA786 UT WOS:A1996WA78600011 ER PT J AU Scheidegger, AM Fendorf, M Sparks, DL AF Scheidegger, AM Fendorf, M Sparks, DL TI Mechanisms of nickel sorption on pyrophyllite: Macroscopic and microscopic approaches SO SOIL SCIENCE SOCIETY OF AMERICA JOURNAL LA English DT Article ID RAY-ABSORPTION SPECTROSCOPY; CHROMIUM(III) SORPTION; SURFACE PRECIPITATION; ADSORPTION-DESORPTION; REACTION-KINETICS; CADMIUM SORPTION; BORON ADSORPTION; OXIDE SURFACES; CLAY-MINERALS; KAOLINITE AB Retention of heavy metal ions on soil mineral surfaces is a crucial process for maintaining environmental quality. A thorough understanding of the sorption mechanisms of heavy metals on soil mineral surfaces is therefore of fundamental importance. This study examined Ni(II) sorption mechanisms on pyrophyllite. The removal of Ni from solution was studied as a function of pH (pH = 5-8.5), initial Ni concentration (1 x 10(-4) to 1 x 10(-2) M), and ionic strength (0.01-1 M). The data suggest that Ni sorption behavior can be divided into two distinct pH regions. In the lower pH region (i.e., pH <7), relative Ni sorption increased with decreasing ionic strength and initial Ni concentration. The adsorption maximum at pH = 6 was significantly higher than the cation-exchange capacity (CEC) at the same pH. Based on these findings, we propose that both specific and nonspecific adsorption are involved. In the higher pH region (pH >7), nickel sorption becomes slow and does not seem to be affected by the ionic strength and the initial Ni concentration. We employed high-resolution transmission electron microscopy (HRTEM) to ascertain whether any alteration in the surface structure of pyrophyllite could be detected after reaction with Ni at pH >7. Surface deposits, not present on untreated samples, were found. At low Ni sorption densities, surface precipitation seems to occur preferentially along the edges of the particles. Based on the HRTEM findings, and on results from a previous x-ray absorption fine structure spectroscopy (XAFS) study, we hypothesize that the formation of a mixed Ni-Al hydroxide phase on the pyrophyllite surface is responsible for the sorption behavior above pH 7. C1 UNIV CALIF BERKELEY,LAWRENCE BERKELEY NALT LAB,NATL CTR ELECTRON MICROSCOPY,BERKELEY,CA 94720. RP Scheidegger, AM (reprint author), UNIV DELAWARE,DEPT PLANT & SOIL SCI,NEWARK,DE 19717, USA. NR 56 TC 53 Z9 53 U1 3 U2 12 PU SOIL SCI SOC AMER PI MADISON PA 677 SOUTH SEGOE ROAD, MADISON, WI 53711 SN 0361-5995 J9 SOIL SCI SOC AM J JI Soil Sci. Soc. Am. J. PD NOV-DEC PY 1996 VL 60 IS 6 BP 1763 EP 1772 PG 10 WC Soil Science SC Agriculture GA WA786 UT WOS:A1996WA78600020 ER PT J AU Davenport, DW Wilcox, BP Breshears, DD AF Davenport, DW Wilcox, BP Breshears, DD TI Soil morphology of canopy and intercanopy sites in a Pinon-Juniper woodland SO SOIL SCIENCE SOCIETY OF AMERICA JOURNAL LA English DT Article ID NEW-MEXICO; NUTRIENT DISTRIBUTION; PINYON; PATTERNS AB Pinon-juniper woodlands in the semiarid western USA have expanded as much as fivefold during the last 150 yr, often accompanied by Losses of understory vegetation and increasing soil erosion. We conducted this study to determine the differences in soil morphology between canopy and intercanopy locations within a pinon (Pinus edulis Engelm.)-juniper [Juniperus monosperma (Engelm.) Sarg.] woodland with uniform parent material, topography, and climate. The woodland studied, located near Los Alamos, NM, has a mean tree age of 135 yr. We examined soil morphology by augering 135 profiles in a square grid pattern and comparing soils under pinon and juniper canopies with intercanopy soils. Only two of the 17 morphological properties compared showed significant differences. The B horizons make up a slightly greater proportion of total profile thickness in intercanopy soils, and there are higher percentages of coarse fragments in the lower portions of canopy soil profiles. Canopy soils have lower mean PEI and higher mean organic C than intercanopy soils. Regression analysis showed that most soil properties did not closely correspond with tree size, but total soil thickness and B horizon thickness are significantly greater under the largest pinon trees, and soil reaction is lower under the largest juniper trees. Our findings suggest that during the period in which pinon-juniper woodlands have been expanding, the trees have had only minor effects on soil morphology. RP Davenport, DW (reprint author), LOS ALAMOS NATL LAB, ENVIRONM SCI GRP, STOP J495, LOS ALAMOS, NM 87545 USA. RI Breshears, David/B-9318-2009 OI Breshears, David/0000-0001-6601-0058 NR 36 TC 37 Z9 38 U1 0 U2 11 PU SOIL SCI SOC AMER PI MADISON PA 677 SOUTH SEGOE ROAD, MADISON, WI 53711 USA SN 0361-5995 J9 SOIL SCI SOC AM J JI Soil Sci. Soc. Am. J. PD NOV-DEC PY 1996 VL 60 IS 6 BP 1881 EP 1887 PG 7 WC Soil Science SC Agriculture GA WA786 UT WOS:A1996WA78600036 ER PT J AU Wolfenstine, J Goretta, KC Cook, RE AF Wolfenstine, J Goretta, KC Cook, RE TI Use of diffusional creep to investigate mass transport in (La, Sr)MnO3 SO SOLID STATE IONICS LA English DT Article DE La1-xSrxMnO3; diffusional creep; cation lattice diffusion ID OXIDATION-REDUCTION BEHAVIOR; OXIDE FUEL-CELLS; SR-DOPED LAMNO3; DEFECT STRUCTURE; ELECTRICAL-CONDUCTIVITY; SINGLE-CRYSTALS; LAMNO3+/-DELTA; CHEMISTRY; CERAMICS; MODEL AB The steady-state creep rate of La1-xSrxMnO3 (x = 0.10, 0.15 and 0.25) decreased with increasing Sr content in a regime where diffusional creep is the dominant deformation mechanism. This composition effect when compared to existing point defect models suggested that the rate-controlling species for mass transport in (La, Sr)MnO3 is lattice diffusion of the cations, either lanthanum or manganese. This is in agreement with previous creep (based on an activation energy comparison) and sintering results. Diffusional creep can be used effectively to investigate mass transport in (La, Sr)MnO3. C1 ARGONNE NATL LAB,ENERGY TECHNOL DIV,ARGONNE,IL 60439. ARGONNE NATL LAB,DIV MAT SCI,ARGONNE,IL 60439. RP Wolfenstine, J (reprint author), UNIV CALIF IRVINE,DEPT CHEM & BIOCHEM ENGN,IRVINE,CA 92717, USA. NR 39 TC 26 Z9 26 U1 0 U2 0 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0167-2738 J9 SOLID STATE IONICS JI Solid State Ion. PD NOV PY 1996 VL 92 IS 1-2 BP 75 EP 83 DI 10.1016/S0167-2738(96)00461-4 PG 9 WC Chemistry, Physical; Physics, Condensed Matter SC Chemistry; Physics GA WA415 UT WOS:A1996WA41500008 ER PT J AU Armstrong, TR Stevenson, JW McCready, DE Paulik, SW Raney, PE AF Armstrong, TR Stevenson, JW McCready, DE Paulik, SW Raney, PE TI The effect of reducing environments on the stability of acceptor substituted yttrium chromite SO SOLID STATE IONICS LA English DT Article DE yttrium chromite; lanthanum chromite; dimensional stability ID DOPED LANTHANUM CHROMITES; ELECTRICAL-CONDUCTIVITY; DEFECT STRUCTURE; TRANSPORT; LACRO3; SYSTEM; YCRO3 AB The dimensional stability of calcium-substituted yttrium chromite was evaluated over a wide range of temperatures, oxygen partial pressures, and compositions, and compared to data collected for calcium-doped lanthanum chromite. Sample expansion was dependent on the concentrations of the acceptor dopant and CaCrO4, a secondary phase observed in samples with greater than 25 mole% calcium, as well as measurement temperature and the oxygen partial pressure. The instability of yttrium chromite in reducing environments was directly related to the loss of lattice oxygen and the simultaneous reduction of Cr4+ to Cr3+ to maintain electroneutrality. The evolution of oxygen and the reduction of chromium resulted in a lattice expansion, caused by the size change associated with the Cr4+ to Cr3+ transition and electrostatic repulsion between adjacent oxygen octahedra. The measured expansion of yttrium chromites was 42% less than that for similarly doped lanthanum chromites. The reduction in expansion is a result of the decreased size of the unit cell (6.5% smaller than calcium-doped lanthanum chromite) which suppresses expansion by hindering the reduction of Cr4+ and oxygen evolution during reduction. RP Armstrong, TR (reprint author), PACIFIC NW LAB, DEPT MAT SCI, POB 999, RICHLAND, WA 99352 USA. NR 31 TC 23 Z9 23 U1 1 U2 7 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0167-2738 EI 1872-7689 J9 SOLID STATE IONICS JI Solid State Ion. PD NOV PY 1996 VL 92 IS 3-4 BP 213 EP 223 DI 10.1016/S0167-2738(96)00448-1 PG 11 WC Chemistry, Physical; Physics, Condensed Matter SC Chemistry; Physics GA WB191 UT WOS:A1996WB19100006 ER PT J AU Shoemaker, EL Vogt, MC Dudek, FJ AF Shoemaker, EL Vogt, MC Dudek, FJ TI Cyclic voltammetry applied to an oxygen-ion-conducting solid electrolyte as an active electrocatalytic gas sensor SO SOLID STATE IONICS LA English DT Article DE oxygen-ion electrolytes; gas sensors; oxygen sensor; solid electrolyte interlaces ID SURFACES AB Cyclic voltammetry was applied to a thick-film electrochemical cell having an oxygen-ion-conducting solid electrolyte. Features of the voltammograms appear to depend uniquely on the type of gas exposed to the cell surface. Temperature dependence was studied. C1 ARGONNE NATL LAB,DIV ENERGY SYST,ARGONNE,IL 60439. NR 7 TC 16 Z9 16 U1 1 U2 1 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0167-2738 J9 SOLID STATE IONICS JI Solid State Ion. PD NOV PY 1996 VL 92 IS 3-4 BP 285 EP 292 DI 10.1016/S0167-2738(96)00419-5 PG 8 WC Chemistry, Physical; Physics, Condensed Matter SC Chemistry; Physics GA WB191 UT WOS:A1996WB19100013 ER PT J AU Kadkhodayan, S Salazar, EP Lamerdin, JE Weber, CA AF Kadkhodayan, S Salazar, EP Lamerdin, JE Weber, CA TI Construction of a functional cDNA clone of the hamster ERCC2 DNA repair and transcription gene SO SOMATIC CELL AND MOLECULAR GENETICS LA English DT Article ID NUCLEOTIDE EXCISION-REPAIR; PIGMENTOSUM GROUP-D; MOLECULAR CHARACTERIZATION; OVARY CELLS; CHO CELLS; MUTANTS; MUTATIONS; DEFECT AB The complete hamster ERCC2 cDNA was constructed in a plasmid vector from clones of three overlapping reverse transcribed/polymerase chain reaction amplified fragments using unique restriction enzyme recognition sites within the regions of overlap. This complete cDNA insert was then closed into a mammalian expression vector, pcD2E, and tested for function by the ability to confer UV resistance to the ERCC2 mutant CHO cell line UV5. Site-specific mutagenesis was used to introduce the G(347) --> A and G(1844) --> A changes resulting in the Cys116 --> Tyr and Gly615 --> Glu mutations previously identified in UV5 and UVL-13 (also an ERCC2 mutant CHO cell line), respectively. The 116(Tyr) and 615(Glu) plasmids each failed to confer UV resistance to UV5 or UVL-13 cells, respectively, demonstrating that the changes identified are indeed the causative mutations in UV5 and UVL-13. RP Kadkhodayan, S (reprint author), LAWRENCE LIVERMORE NATL LAB,BIOL & BIOTECHNOL RES PROGRAM,LIVERMORE,CA 94551, USA. FU NCI NIH HHS [CA52679] NR 21 TC 9 Z9 9 U1 0 U2 0 PU PLENUM PUBL CORP PI NEW YORK PA 233 SPRING ST, NEW YORK, NY 10013 SN 0740-7750 J9 SOMAT CELL MOLEC GEN JI Somat.Cell Mol.Genet. PD NOV PY 1996 VL 22 IS 6 BP 453 EP 460 DI 10.1007/BF02369437 PG 8 WC Biochemistry & Molecular Biology; Cell Biology; Genetics & Heredity SC Biochemistry & Molecular Biology; Cell Biology; Genetics & Heredity GA WV994 UT WOS:A1996WV99400003 PM 9131015 ER PT J AU Lelovic, M Deis, T Eror, NG Balachandran, U Haldar, P AF Lelovic, M Deis, T Eror, NG Balachandran, U Haldar, P TI The effect of cooling rates on transport current properties and the critical temperature of Ag-sheathed BSCCO-2223 superconducting tapes SO SUPERCONDUCTOR SCIENCE & TECHNOLOGY LA English DT Article ID CRITICAL-CURRENT DENSITY; COMPOSITE CONDUCTORS; MICROSTRUCTURE; POWDER; TRANSITION; BI-2223; (BI AB The transport current properties of Ag-sheathed (Bi, Pb)(2)Sr2Ca2Cu3Oy BSCCO-2223 superconducting tapes were analysed as a function of cooling rate. Changing the cooling rate showed a pronounced effect on the transport current of the superconductor heat-treated at 810 degrees C in a 7% O-2 atmosphere. Results indicated that, during fast cooling, the thin layer of BSCCO adjacent to the Ag sheath is under compression. The compressive stress causes microcracking and affects the alignment and interconnectivity of 2223 grains in the thin layer of BSCCO next to the silver sheath. This changes the current path through the high-critical-current-density region in the superconductor. A comparison between furnace-cooled tapes and slowly cooled tapes (10 degrees C h(-1) to 780 degrees C and then 1 degrees C min(-1) to room temperature) showed-that the latter attained two or three times higher I-c values. Based on this observation, a cooling schedule that includes several intermediate cooling steps is suggested. The effect of the lattice parameter on T-c was investigated. Behaviour analogous to that of the 2212 phase was found, T-c was affected by changes in the c-axis of the 2223 phase. However, the effect was not as pronounced as it was in the 2212 phase. C1 ARGONNE NATL LAB,DIV ENERGY TECHNOL,ARGONNE,IL 60439. INTERMAGNET GEN CORP,LATHAM,NY 12110. RP Lelovic, M (reprint author), UNIV PITTSBURGH,DEPT MAT SCI,PITTSBURGH,PA 15261, USA. NR 28 TC 24 Z9 24 U1 2 U2 7 PU IOP PUBLISHING LTD PI BRISTOL PA TECHNO HOUSE, REDCLIFFE WAY, BRISTOL, ENGLAND BS1 6NX SN 0953-2048 J9 SUPERCOND SCI TECH JI Supercond. Sci. Technol. PD NOV PY 1996 VL 9 IS 11 BP 965 EP 970 DI 10.1088/0953-2048/9/11/007 PG 6 WC Physics, Applied; Physics, Condensed Matter SC Physics GA VR547 UT WOS:A1996VR54700007 ER PT J AU Jia, QX Reagor, D Kung, H Hawley, M Mombourquette, C Foltyn, SR Wu, XD Peterson, DE AF Jia, QX Reagor, D Kung, H Hawley, M Mombourquette, C Foltyn, SR Wu, XD Peterson, DE TI High-temperature superconductor edge-geometry SNS junctions with engineered normal-metal layers SO SUPERCONDUCTOR SCIENCE & TECHNOLOGY LA English DT Article ID JOSEPHSON-JUNCTIONS; DC SQUIDS; YBA2CU3O7; BARRIERS; LINKS AB High-temperature superconductor Josephson junctions in an edge-geometry superconductor-normal-metal-superconductor (SNS) configuration were fabricated on LaAlO3 substrates. The normal metal was composed of an engineered multilayer Y1-xPrxBa2Cu3O7-delta with different Pr-doping concentrations (x = 0.1, 0.3, or 0.5). Scanning tunnelling microscopy analysis on Y1-xPrxBa2Cu3O7-delta thin films provided supporting evidence for the use of such an engineered multilayer as N barrier to fabricate edge-geometry SNS junctions. The improved S-N or N-S interface, as revealed by cross-sectional transmission electron microscopy, explains the negligible interface resistance of the junctions. C1 LOS ALAMOS NATL LAB,ELECT MAT & DEVICE RES,LOS ALAMOS,NM 87545. LOS ALAMOS NATL LAB,CTR MAT SCI,LOS ALAMOS,NM 87545. RP Jia, QX (reprint author), LOS ALAMOS NATL LAB,SUPERCOND TECHNOL CTR,MAIL STOP G755,LOS ALAMOS,NM 87545, USA. RI Jia, Q. X./C-5194-2008 NR 19 TC 4 Z9 4 U1 1 U2 1 PU IOP PUBLISHING LTD PI BRISTOL PA TECHNO HOUSE, REDCLIFFE WAY, BRISTOL, ENGLAND BS1 6NX SN 0953-2048 J9 SUPERCOND SCI TECH JI Supercond. Sci. Technol. PD NOV PY 1996 VL 9 IS 11 BP 985 EP 990 DI 10.1088/0953-2048/9/11/010 PG 6 WC Physics, Applied; Physics, Condensed Matter SC Physics GA VR547 UT WOS:A1996VR54700010 ER PT J AU Groenewold, GS Cowan, RL Ingram, JC Appelhans, AD Delmore, JE Olson, JE AF Groenewold, GS Cowan, RL Ingram, JC Appelhans, AD Delmore, JE Olson, JE TI Characterization of bis-(phenoxy)phosphazene polymers using static secondary ion mass spectrometry SO SURFACE AND INTERFACE ANALYSIS LA English DT Article ID CROSS-LINKABLE POLYPHOSPHAZENE; MEMBRANES; POLY(ORGANOPHOSPHAZENES); CYCLOPHOSPHAZENES; ELECTROLYTES; IONIZATION; MATRIX; GAS AB Phosphazene polymers are a class of materials that are finding applications in membrane separations. A series of substituted bis(phenoxy)phosphazene polymers were characterized using static secondary ion mass spectrometry. The anion spectra contained ions which originate from the phosphazene backbone, as well as from the pendant aromatic moieties. The cation spectra also contained ions derived from the pendant moieties, but consisted primarily of ions which arise from adventitious surface contaminants, such as siloxane compounds and hydrocarbons. The backbone-derived ions could be distinguished from the pendant-derived ions on the basis of their response to prolonged primary ion bombardment: the pendant ions decay at rates that are generally two to four times the rates observed for tbe backbone ions. This observation is interpreted in terms of the pendant moieties being more easily removed during ablation than the backbone ions. RP Groenewold, GS (reprint author), IDAHO NATL ENGN LAB,POB 1625,IDAHO FALLS,ID 83415, USA. NR 31 TC 9 Z9 9 U1 0 U2 1 PU JOHN WILEY & SONS LTD PI W SUSSEX PA BAFFINS LANE CHICHESTER, W SUSSEX, ENGLAND PO19 1UD SN 0142-2421 J9 SURF INTERFACE ANAL JI Surf. Interface Anal. PD NOV PY 1996 VL 24 IS 12 BP 794 EP 802 DI 10.1002/(SICI)1096-9918(199611)24:12<794::AID-SIA185>3.0.CO;2-A PG 9 WC Chemistry, Physical SC Chemistry GA VW114 UT WOS:A1996VW11400002 ER PT J AU Walter, KC Scheuer, JT McIntyre, PC Kodali, P Yu, N Nastasi, M AF Walter, KC Scheuer, JT McIntyre, PC Kodali, P Yu, N Nastasi, M TI Increased wear resistance of electrodeposited chromium through applications of plasma source ion implantation techniques SO SURFACE & COATINGS TECHNOLOGY LA English DT Article; Proceedings Paper CT 2nd International Workshop on Plasma-Based Ion Implantation CY FEB 12-15, 1995 CL SUTHERLAND, AUSTRALIA SP Austr Nucl Sci & Technol Org DE plasma source ion implantation; ion implantation; electrodeposited chrome ID NITROGEN; METALS; FILMS; MICROSTRUCTURE; BEHAVIOR; FRICTION; LAYERS AB Three plasma source ion implantation (PSII) processes, using either ammonia (NH3), methane (CH4), or oxygen (O-2) gases, are shown to increase the surface hardness and wear resistance of electrodeposited hard chromium. Characterization of the implanted surfaces indicates the formation of hard compounds, namely polycrystalline chromium-nitride (CrN), chromium-carbide (Cr3C2), and chromium-oxide (Cr2O3). For wear resistant applications of hard Cr coatings, PSII processes could extend the wear lifetime of coated components. By extending the lifetime and thus reducing the need for re-coating, PSII processes could also reduce the amounts of carcinogenic Cr+6 released into the environment. RP Walter, KC (reprint author), LOS ALAMOS NATL LAB,LOS ALAMOS,NM 87545, USA. NR 19 TC 46 Z9 50 U1 0 U2 0 PU ELSEVIER SCIENCE SA LAUSANNE PI LAUSANNE 1 PA PO BOX 564, 1001 LAUSANNE 1, SWITZERLAND SN 0257-8972 J9 SURF COAT TECH JI Surf. Coat. Technol. PD NOV 1 PY 1996 VL 85 IS 1-2 BP 1 EP 6 DI 10.1016/0257-8972(96)02886-1 PG 6 WC Materials Science, Coatings & Films; Physics, Applied SC Materials Science; Physics GA VL207 UT WOS:A1996VL20700002 ER PT J AU Wood, BP Reass, WA Henins, I AF Wood, BP Reass, WA Henins, I TI Plasma source ion implantation of metal ions: Synchronization of cathodic-arc plasma production and target bias pulses SO SURFACE & COATINGS TECHNOLOGY LA English DT Article; Proceedings Paper CT 2nd International Workshop on Plasma-Based Ion Implantation CY FEB 12-15, 1995 CL SUTHERLAND, AUSTRALIA SP Austr Nucl Sci & Technol Org DE vacuum are; cathodic are; plasma source ion implantation; metal; plasma; erbium ID IMMERSION AB An erbium cathodic-arc has been installed on a plasma source ion implantation (PSII) experiment to allow the implantation of erbium metal and the growth of adherent erbia (erbium oxide) films on a variety of substrates. The operation of the PSII pulser and the cathodic-arc are synchronized to achieve pure implantation, rather than the hybrid implantation/deposition being investigated in other laboratories. The relative phase of the 20 mu s PSII and the cathodic-arc pulses can be adjusted to tailor the energy distribution of the implanted ions and suppress the initial high-current drain on the pulse modulator. We present experimental data on this effect and make a comparison with the results from particle-in-cell simulations. RP Wood, BP (reprint author), LOS ALAMOS NATL LAB,LOS ALAMOS,NM 87545, USA. NR 13 TC 15 Z9 15 U1 1 U2 2 PU ELSEVIER SCIENCE SA LAUSANNE PI LAUSANNE 1 PA PO BOX 564, 1001 LAUSANNE 1, SWITZERLAND SN 0257-8972 J9 SURF COAT TECH JI Surf. Coat. Technol. PD NOV 1 PY 1996 VL 85 IS 1-2 BP 70 EP 74 DI 10.1016/0257-8972(96)02875-7 PG 5 WC Materials Science, Coatings & Films; Physics, Applied SC Materials Science; Physics GA VL207 UT WOS:A1996VL20700012 ER PT J AU Anders, S Anders, A Brown, I Kong, F McLarnon, F AF Anders, S Anders, A Brown, I Kong, F McLarnon, F TI Surface modification of nickel battery electrodes by cobalt plasma immersion ion implantation and deposition SO SURFACE & COATINGS TECHNOLOGY LA English DT Article; Proceedings Paper CT 2nd International Workshop on Plasma-Based Ion Implantation CY FEB 12-15, 1995 CL SUTHERLAND, AUSTRALIA SP Austr Nucl Sci & Technol Org DE nickel battery electrodes; cobalt plasma immersion ion implantation; alkaline-electrolyte batteries AB Nickel hydroxide is the electrochemically active material in the positive electrode of several important rechargeable alkaline-electrolyte batteries. It is believed that the Ni2+ in nickel hydroxide is converted to Ni3+ in nickel oxy-hydroxide as the electrode is electrochemically oxidized during the battery charging process, and the reverse reaction (electrochemical reduction) occurs during the battery discharge. However, the details of this process are not completely understood. Because these electrochemical reactions involve surface charge-transfer processes, it is anticipated that the modification of the electrode surface may result in an improved battery performance. We used broad-beam metal ion implantation and the new technique of metal plasma immersion ion implantation and deposition (MePIIID) to add cobalt and other species to the nickel electrode surface. The principle of the latter technique is explained in detail. It has been demonstrated that implanted and deposited cobalt ions (acting as electronic dopants) balance the huge difference in the conductivities of nickel hydroxide and nickel oxy-hydroxide. This beneficial effect promotes a more complete interconversion between the nickel hydroxide and the nickel oxy-hydroxide and leads to a higher capacity and efficiency of the nickel hydroxide electrode in the batteries applications. RP Anders, S (reprint author), UNIV CALIF BERKELEY,LAWRENCE BERKELEY NATL LAB,BERKELEY,CA 94720, USA. RI Anders, Andre/B-8580-2009; Raoux, Simone/G-3920-2016 OI Anders, Andre/0000-0002-5313-6505; NR 14 TC 7 Z9 7 U1 1 U2 3 PU ELSEVIER SCIENCE SA LAUSANNE PI LAUSANNE 1 PA PO BOX 564, 1001 LAUSANNE 1, SWITZERLAND SN 0257-8972 J9 SURF COAT TECH JI Surf. Coat. Technol. PD NOV 1 PY 1996 VL 85 IS 1-2 BP 75 EP 79 DI 10.1016/0257-8972(96)02878-2 PG 5 WC Materials Science, Coatings & Films; Physics, Applied SC Materials Science; Physics GA VL207 UT WOS:A1996VL20700013 ER PT J AU Sepaniak, MJ Vo-Dinh, T Stokes, DL Tropina, V Dickens, JE AF Sepaniak, MJ Vo-Dinh, T Stokes, DL Tropina, V Dickens, JE TI Demonstration of an integrated capillary electrophoresis laser-induced fluorescence fiber-optic sensor SO TALANTA LA English DT Article DE capillary electrophoresis; integrated fiber-optic sensor; laser-induced fluorescence ID ZONE ELECTROPHORESIS; BENZOPYRENE METABOLITE; CHEMICAL-ANALYSIS AB A unique integrated separation-based fiber-optic sensor for remote analysis, that incorporates capillary electrophoresis (CE) directly at the fiber sensing terminus is described for the first time. Based on laser-induced fluorescence detection, the sensor offers the potential for high sensitivity. Although the broad-band nature of fluorescence spectra limits selectivity, the high separation power of CE provides a unique dimension of selectivity, while permitting a design of diminutive size. Previously reported fluorescence-based sensors that utilize a chemical reagent phase to impart selectivity tend to be inflexible (not readily adaptable to the detection of different species) and ''one-measurement-only'' sensors. Conversely, the CE-based fiber-optic sensor described here is both versatile and reusable. The analysis speed and the potential for remote control are further attributes which make the system amenable to remote sensing. A ''single-fiber'' optical detection arrangement and a ''single-reservoir'' CE system with the fiber-optic probing the outlet of the separation capillary are employed. A preliminary evaluation of the separation characteristics of this CE-based sensor is presented. Highlights include an observed separation efficiency of up to 3000 theoretical plates (8 cm separation capillary) and migration time reproducibility of less than 10% for frontal mode CE separations. The potential utility of the sensor for remote analysis is demonstrated with separations involving the CE analysis of charged fluorescent dyes, CE analysis of metal complexes based on in situ complexation and micellar electrokinetic capillary chromatographic analysis of neutral fluorescent compounds. C1 OAK RIDGE ASSOCIATED UNIV, ADV MONITORING DEV GRP, DIV HLTH SCI, OAK RIDGE, TN 37831 USA. RP UNIV TENNESSEE, DEPT CHEM, KNOXVILLE, TN 37996 USA. NR 41 TC 15 Z9 16 U1 1 U2 3 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0039-9140 EI 1873-3573 J9 TALANTA JI Talanta PD NOV PY 1996 VL 43 IS 11 BP 1889 EP 1901 DI 10.1016/0039-9140(96)01965-0 PG 13 WC Chemistry, Analytical SC Chemistry GA VK974 UT WOS:A1996VK97400009 PM 18966678 ER PT J AU Fedorov, V AF Fedorov, V TI Factor-based or effect-based modeling? Implications for design - Discussion SO TECHNOMETRICS LA English DT Editorial Material ID DISCRIMINATION RP Fedorov, V (reprint author), OAK RIDGE NATL LAB,MATH SCI SECT,OAK RIDGE,TN 37831, USA. NR 5 TC 0 Z9 0 U1 0 U2 0 PU AMER STATIST ASSN PI ALEXANDRIA PA 1429 DUKE ST, ALEXANDRIA, VA 22314 SN 0040-1706 J9 TECHNOMETRICS JI Technometrics PD NOV PY 1996 VL 38 IS 4 BP 321 EP 322 PG 2 WC Statistics & Probability SC Mathematics GA VP434 UT WOS:A1996VP43400004 ER PT J AU Struss, D Quiros, CF Plieske, J Robbelen, G AF Struss, D Quiros, CF Plieske, J Robbelen, G TI Construction of Brassica B genome synteny groups based on chromosomes extracted from three different sources by phenotypic, isozyme and molecular markers SO THEORETICAL AND APPLIED GENETICS LA English DT Article DE Brassica; B-genome addition lines; Phoma resistance; molecular markers; chromosome synteny ID ADDITION LINES; RFLP MARKERS; PHOMA-LINGAM; NAPUS; NIGRA; CAMPESTRIS; TRANSLOCATIONS; RESISTANCE; OLERACEA; HYBRIDS AB The three B genomes of Brassica contained in B. nigra, B. carinata and B. juncea were dissected by addition in B. napbus. Using phenotypic, isozyme and molecular markers we characterized 8 alien B-genome chromosomes from B. nigra and B. carinata and 7 from B. juncea by constructing synteney groups. The alien chromosomes of the three different sources showed extensive intragenomic recombinations that were detected by the presence of the same loci in more than one synteny group but flanked by different markers. In addition, intergenomic recombinations were observed. These were evident in euploid AACC plants of the rapeseed phenotype derived from the addition lines carrying a few markers from the B genome due to translocations and recombinations between non-homoeologous chromosomes. The high plasticity of the Brassica genomes may have been an powerful factor in directing their evolution by hybridization and amphiploidy. C1 LAWRENCE LIVERMORE NATL LAB,DEPT VEGETABLE CROPS,DAVIS,CA 95616. UNIV GOTTINGEN,INST AGRON & PLANT BREEDING,D-37075 GOTTINGEN,GERMANY. RP Struss, D (reprint author), IPK,INST PLANT GENET & CROP PLANT RES,CORRENSSTR 3,D-06466 GATERSLEBEN,GERMANY. NR 37 TC 41 Z9 47 U1 0 U2 1 PU SPRINGER VERLAG PI NEW YORK PA 175 FIFTH AVE, NEW YORK, NY 10010 SN 0040-5752 J9 THEOR APPL GENET JI Theor. Appl. Genet. PD NOV PY 1996 VL 93 IS 7 BP 1026 EP 1032 PG 7 WC Agronomy; Plant Sciences; Genetics & Heredity; Horticulture SC Agriculture; Plant Sciences; Genetics & Heredity GA VX002 UT WOS:A1996VX00200003 PM 24162476 ER PT J AU Beckman, RJ Baggerly, KA McKay, MD AF Beckman, RJ Baggerly, KA McKay, MD TI Creating synthetic baseline populations SO TRANSPORTATION RESEARCH PART A-POLICY AND PRACTICE LA English DT Article ID COMPLEX TRAVEL BEHAVIOR; MODEL AB To develop activity-based travel models using microsimulation, individual travelers and households must be considered. Methods for creating baseline synthetic populations of households and persons using 1990 census data are given. Summary tables from the Census Bureau STF-3A are used in conjunction with the Public Use Microdata Sample (PUMS), and Iterative Proportional Fitting (IPF) is applied to estimate the proportion of households in a block group or census tract with a desired combination of demographics. Households are generated by selection of households from the associated PUMS according to these proportions. The tables of demographic proportions which are exploited here to make household selections from the PUMS may be used in traditional modeling. The procedures are validated by creating pseudo census tracts from PUMS samples and considering the joint distribution of the size of households and the number of vehicles in the households. It is shown that the joint distributions created by these methods do not differ substantially from the true values. Additionally the effects of small changes in the procedure, such as imputation of additional demographics and adding partial counts to the constructed demographic tables are discussed in the paper. RP Beckman, RJ (reprint author), LOS ALAMOS NATL LAB,STAT GRP,LOS ALAMOS,NM 87545, USA. NR 16 TC 151 Z9 153 U1 1 U2 19 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD, ENGLAND OX5 1GB SN 0965-8564 J9 TRANSPORT RES A-POL JI Transp. Res. Pt. A-Policy Pract. PD NOV PY 1996 VL 30 IS 6 BP 415 EP 429 DI 10.1016/0965-8564(96)00004-3 PG 15 WC Economics; Transportation; Transportation Science & Technology SC Business & Economics; Transportation GA VR456 UT WOS:A1996VR45600002 ER PT J AU Mandelkern, L Alamo, RG Wignall, GD Stehling, FC AF Mandelkern, L Alamo, RG Wignall, GD Stehling, FC TI The phase structure of blends of the different polyethylenes SO TRENDS IN POLYMER SCIENCE LA English DT Article ID ANGLE NEUTRON-SCATTERING; LOW-DENSITY POLYETHYLENE; X-RAY-SCATTERING; LINEAR LOW-DENSITY; SATURATED-HYDROCARBON POLYMERS; BRANCHED POLYETHYLENES; CRYSTALLIZATION KINETICS; LIGHT-SCATTERING; SEGREGATION; COCRYSTALLIZATION AB The phase structures of binary mixtures of polyethylenes having different molecular architectures are discussed in detail. The various types of structures that are involved include linear, or high-density, polyethylene; linear low-density polyethylenes, which are copolymers of ethylene with a 1-alkene as comonomer; low-density polyethylene, which contains long-chain as well as short-chain alkyl branches; and copolymers whose comonomers are not an alkene. The main focus is given to the properties of blends composed of model compounds in these different categories. These results serve as a base to understand the more polydisperse blends of commercial interest. A matter of major interest involves the homogeneity of the melt, a problem that can be directly addressed by small-angle neutron scattering. In the solid or crystalline state, a crucial matter is whether or not cocrystallization takes place between the two components. A variety of experimental methods have been use to study this problem, and the results are analyzed. The strong influences of comonomer or branch concentration, blend composition and crystallization conditions on the resultant phase structure become apparent. C1 FLORIDA STATE UNIV,INST MOL BIOPHYS,TALLAHASSEE,FL 32306. FLORIDA STATE UNIV,DEPT CHEM,TALLAHASSEE,FL 32306. FLORIDA STATE UNIV,COLL ENGN,DEPT CHEM ENGN,TALLAHASSEE,FL 32310. FLORIDA A&M UNIV,TALLAHASSEE,FL 32310. OAK RIDGE NATL LAB,OAK RIDGE,TN 37831. NR 41 TC 21 Z9 21 U1 0 U2 3 PU ELSEVIER SCI LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD, OXON, ENGLAND OX5 1GB SN 0966-4793 J9 TRENDS POLYM SCI JI Trends Polym. Sci. PD NOV PY 1996 VL 4 IS 11 BP 377 EP 383 PG 7 WC Polymer Science SC Polymer Science GA VV104 UT WOS:A1996VV10400005 ER PT J AU Oldenburg, CM Pruess, K Travis, BJ AF Oldenburg, CM Pruess, K Travis, BJ TI Dispersive transport dynamics in a strongly coupled groundwater-brine flow system - Reply SO WATER RESOURCES RESEARCH LA English DT Editorial Material C1 LOS ALAMOS NATL LAB,DIV EARTH & ENVIRONM SCI,LOS ALAMOS,NM 87545. RP Oldenburg, CM (reprint author), UNIV CALIF BERKELEY,DIV EARTH SCI,LAWRENCE BERKELEY LAB,BERKELEY,CA 94941, USA. RI Oldenburg, Curtis/L-6219-2013 OI Oldenburg, Curtis/0000-0002-0132-6016 NR 4 TC 10 Z9 10 U1 0 U2 2 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 SN 0043-1397 J9 WATER RESOUR RES JI Water Resour. Res. PD NOV PY 1996 VL 32 IS 11 BP 3411 EP 3412 DI 10.1029/96WR02496 PG 2 WC Environmental Sciences; Limnology; Water Resources SC Environmental Sciences & Ecology; Marine & Freshwater Biology; Water Resources GA VQ428 UT WOS:A1996VQ42800019 ER PT J AU Chen, Z Liu, P Verhoeven, JD Gibson, ED AF Chen, Z Liu, P Verhoeven, JD Gibson, ED TI Behavior of Cu-20%Nb and Cu-15%Cr in situ composites under dry sliding conditions SO WEAR LA English DT Article DE tribology; in situ composites; dry sliding ID TRIBOLOGICAL BEHAVIOR AB The tribological behavior of Cu-20%Nb and Cu-15%Cr in situ composites was studied on a pin-on-disk tester. Composite pins were slid against a hardened AISI 52100 steel disk under dry ambient conditions, Comparison of coefficient of friction, wear rate and bulk temperature was made between the two composites in terms of effects of normal pressure and sliding speed, Microstructural changes in the composites due to sliding were studied and correlated with the change of tribological behavior. The wear rate increased with increasing normal pressure and decreased with increasing sliding speed in the studied range of normal pressure (0.06-0.56 MPa) and sliding speed (2.50-5.83 m s(-1)) for both composites. Cu-20%Nb showed a much better wear resistance and a lower coefficient of friction than Cu-15%Cr. The coefficient of friction slightly increased for Cu-20%Nb and slightly decreased for Cu-15%Cr with increasing normal pressure, The coefficient of friction for both composites decreased with increasing sliding speed. The bulk temperature was higher and subsurface deformation layer thickness was larger for Cu-15%Cr than for Cu-20%Nb. Both of them increased with increasing normal pressure and sliding speed. Scanning electron microscopy analysis showed plastic deformation flow on the wear surface at an early stage for both composites. However, the formation of a surface film led Cu-20%Nb composite to reach a steady state much sooner and therefore to have a lower wear rate than Cu-15%Cr. C1 EASTERN ILLINOIS UNIV,COLL APPL SCI,SCH TECHNOL,CHARLESTON,IL 61920. IOWA STATE UNIV,US DOE,AMES LAB,DEPT MAT SCI & ENGN,AMES,IA 50011. NR 12 TC 9 Z9 11 U1 0 U2 1 PU ELSEVIER SCIENCE SA LAUSANNE PI LAUSANNE 1 PA PO BOX 564, 1001 LAUSANNE 1, SWITZERLAND SN 0043-1648 J9 WEAR JI Wear PD NOV 1 PY 1996 VL 199 IS 1 BP 74 EP 81 DI 10.1016/0043-1648(96)07216-X PG 8 WC Engineering, Mechanical; Materials Science, Multidisciplinary SC Engineering; Materials Science GA VN217 UT WOS:A1996VN21700010 ER PT J AU Vianco, PT Hosking, FM Rejent, JA AF Vianco, PT Hosking, FM Rejent, JA TI Ultrasonic soldering for structural and electronic applications SO WELDING JOURNAL LA English DT Article DE soldering; ultrasonics; solder coating; electronic components; solder cavitation; 100Sn; 60Sn-40Pb; Au-plated wires AB A study was performed which examined the use of ultrasonic activation as a means of solder coating metal surfaces without the requirement of a fluxing agent. Fundamental studies on copper plates revealed that oxide removal and subsequent solder wetting resulted from both mechanical erosion and coupling of sonic energy from the source (horn) into the substrate. Cavitation was removed from the surface oxide layer. Coupling efficiency was dependent upon the power level, horn sample separation, and the substrate geometry. inefficient coupling was characterized by a reduced area of solder coating and significant erosion of those regions that were wetted by the solder. in the absence of a flux, traditional meniscus rise and capillary flow processes were limited. Case studies illustrated the use of ultrasonic soldering in the coating of printed circuit board copper features and electronic package leads. RP Vianco, PT (reprint author), SANDIA NATL LABS,CTR SOLDER SCI & TECHNOL,ALBUQUERQUE,NM 87185, USA. NR 12 TC 3 Z9 3 U1 2 U2 5 PU AMER WELDING SOC PI MIAMI PA PO BOX 351040, MIAMI, FL 33135 SN 0043-2296 J9 WELD J JI Weld. J. PD NOV PY 1996 VL 75 IS 11 BP S343 EP S355 PG 13 WC Metallurgy & Metallurgical Engineering SC Metallurgy & Metallurgical Engineering GA VP448 UT WOS:A1996VP44800019 ER PT J AU Wang, XM Riedl, B Geimer, RL Christiansen, AW AF Wang, XM Riedl, B Geimer, RL Christiansen, AW TI Phenol-formaldehyde resin curing and bonding under dynamic conditions SO WOOD SCIENCE AND TECHNOLOGY LA English DT Article ID FLAKEBOARD MANUFACTURE; WOOD; FUNDAMENTALS; TEMPERATURE; ADHESIVES; CURE AB To better understand the curing and bonding behavior ai phenol-formaldehyde (PF) resin under dynamic conditions, flakeboards were manufactured either by conventional pressing at 7% or 12% mat moisture content or by steam injection pressing with 10 or 20 seconds steaming duration. Resin-impregnated glass-cloth samples and lap-shear tension specimens were embedded in the core of each flakeboard. After the flakeboards were pressed for various periods of times, the samples and specimens were quickly retrieved. The degree of resin cure was determined on the resin-impregnated glass-cloth samples by dynamic mechanical analysis. The bond strengths were measured from the lap-shear tension specimens on a mechanical testing machine. The results of resin curing and bonding were then correlated to the performance of the resin-bonded boards, which were evaluated by internal bond, modulus of rupture, modulus of elasticity, and thickness swelling. Resin curing and lap-shear bonding did not proceed simultaneously. In conventional pressing, the mat moisture content (MC) at 12% favored resin curing, but slightly retarded lap-shear bonding, as compared to 7%MC. In steam injection pressing, the rates of resin curing and lap-shear bond strength development were much faster for 20 seconds than for 10 seconds of steaming duration. Longer press times were needed to obtain boards with maximum strength in the 12%MC conventional pressing and the 20-s steam duration steam injection pressing than in those conditions where moisture content was lower or steam time was less. The need for longer press times must be attributed to higher internal vapor pressures and/or lower wood and resin component strengths, rather than to incomplete cure or bonding. C1 UNIV LAVAL,FAC FORESTERIE & GEOMAT,DEPT SCI BOIS & FORET,CTR RECH SCI & INGN MACROMOL,QUEBEC CITY,PQ G1K 7P4,CANADA. NATL RENEWABLE ENERGY LAB,GOLDEN,CO 80401. US FOREST SERV,FOREST PROD LAB,USDA,MADISON,WI 53705. NR 25 TC 6 Z9 6 U1 0 U2 2 PU SPRINGER VERLAG PI NEW YORK PA 175 FIFTH AVE, NEW YORK, NY 10010 SN 0043-7719 J9 WOOD SCI TECHNOL JI Wood Sci. Technol. PD NOV PY 1996 VL 30 IS 6 BP 423 EP 442 PG 20 WC Forestry; Materials Science, Paper & Wood SC Forestry; Materials Science GA WE185 UT WOS:A1996WE18500005 ER PT J AU Yang, ZM Bisson, LF AF Yang, ZM Bisson, LF TI The SKS1 protein kinase is a multicopy suppressor of the snf3 mutation of Saccharomyces cerevisiae SO YEAST LA English DT Article DE Saccharomyces cerevisiae; SKS1; protein kinase; glucose transport ID AFFINITY GLUCOSE-TRANSPORT; FISSION YEAST; SCHIZOSACCHAROMYCES-POMBE; HXT GENES; HEXOSE TRANSPORTERS; BINDING PROTEIN; MEIOSIS; CAMP; REPRESSION; ENCODES AB Saccharomyces cerevisiae strains carrying snf3 are defective in high affinity glucose transport, and thus are unable to grow fermentatively on media with low concentrations of glucose. A multicopy suppressor of the snf3 growth defect, SKS1 (suppressor kinase of snf3), was found to encode a putative ser/thr protein kinase homologous to Ran1p, a kinase that regulates the switch between meiosis and vegetative growth in Schizosaccharomyces pombe. Overexpression of the SKS1 open reading frame is sufficient for suppression of the growth defects of snf3 mutants. Disruption of the open reading frame eliminates this suppression; as does the mutation of the consensus ATP binding site of Sks1p. A DDSE (DNA dependent snf3 Suppressor element) was found to be present in the SKS1 promoter region. The suppression by this DDSE occurs in the absence of SKS1 coding region, that is, the DDSE can suppress a snf3 sks1 double null mutant which fails to grow fermentatively on low glucose as a snf3 mutant does. Both SKS1 and its DDSE can additionally suppress the growth defects of girl mutants, which are also impaired in high affinity glucose transport. The snf3 genomic suppressors, rgt1, RGT2 and ssn6, are also capable of suppressing snf3 associated growth defects in a strain lacking sks1. C1 LAWRENCE LIVERMORE NATL LAB,DEPT VITICULTURE & ENOL,DAVIS,CA 95616. RI Yang, Zhaomin/D-4791-2016 OI Yang, Zhaomin/0000-0002-2044-6793 NR 40 TC 17 Z9 19 U1 0 U2 2 PU JOHN WILEY & SONS LTD PI W SUSSEX PA BAFFINS LANE CHICHESTER, W SUSSEX, ENGLAND PO19 1UD SN 0749-503X J9 YEAST JI Yeast PD NOV PY 1996 VL 12 IS 14 BP 1407 EP 1419 PG 13 WC Biochemistry & Molecular Biology; Biotechnology & Applied Microbiology; Microbiology; Mycology SC Biochemistry & Molecular Biology; Biotechnology & Applied Microbiology; Microbiology; Mycology GA VU397 UT WOS:A1996VU39700002 PM 8948096 ER PT J AU Kleinke, H Franzen, HF AF Kleinke, H Franzen, HF TI Synthesis, crystal structure, and properties of HfM'P (M'=Fe, Co, Ni) in comparison to ZrNiP SO ZEITSCHRIFT FUR ANORGANISCHE UND ALLGEMEINE CHEMIE LA English DT Article DE hafnium iron (cobalt, nickel) phosphide; preparation; crystal structure ID TA-NB-S; HIGH-TEMPERATURES; LAYERED COMPOUND; SYSTEM; TANTALUM; PHOSPHIDE; SULFIDES; PHASES; CHAIN AB The new phosphides HfM'P (M' = Fe, Co, Ni) have been synthesized by are melting of HfP and the corresponding 3 d metal, and subsequent annealing at 1400 degrees C. The lattice constants vary from a = 6.247(2)Angstrom, b = 3.7177(6)Angstrom, c = 7.137(2) Angstrom, V = 165.74(8) Angstrom(3) for HfFeP, a = 6.295(3) Angstrom, b = 3.668(2) Angstrom, c = 7.175(4) Angstrom, V = 165.7(2) Angstrom(3) for HfCoP to a = 6.240(3) Angstrom, b = 3.716(2) Angstrom, c = 7.135(2) A, V = 165.4(2) Angstrom(3) (HfNiP) in the orthorhombic space group Pnma. Although ZrNiP occurs only in the Ni2In structure type, all three I-If phosphides crystallize in the Co2Si structure type, isotypic to ZrFeP and ZrCoP. The structural differences between HfNiP and ZrNiP can be explained by the preference of Hf for structures with more metal-metal bonds rather than by size effects. RP Kleinke, H (reprint author), IOWA STATE UNIV SCI & TECHNOL,US DOE,AMES LAB,AMES,IA 50011, USA. NR 66 TC 14 Z9 14 U1 2 U2 17 PU JOHANN AMBROSIUS BARTH VERLAG PI HEIDELBERG PA IM WEIHER 10, D-69121 HEIDELBERG, GERMANY SN 0044-2313 J9 Z ANORG ALLG CHEM JI Z. Anorg. Allg. Chem. PD NOV PY 1996 VL 622 IS 11 BP 1893 EP 1900 DI 10.1002/zaac.19966221114 PG 8 WC Chemistry, Inorganic & Nuclear SC Chemistry GA VT700 UT WOS:A1996VT70000013 ER PT J AU Smith, DH Sampath, R Dadyburjor, DB AF Smith, DH Sampath, R Dadyburjor, DB TI Temperature dependence of emulsion morphologies and the dispersion morphology diagram .3. Inversion hysteresis lines for emulsions of middle and bottom phases of the system C6H13(OC2H4)(2)OH/n-tetradecane/''water'' SO JOURNAL OF PHYSICAL CHEMISTRY LA English DT Article ID 3-PHASE EMULSIONS; ELECTRICAL CONDUCTIVITIES; WATER-SYSTEM; MICROEMULSION; CATASTROPHE AB The morphologies and phase volume fractions at which inversion occurred for (macro)emulsions formed by the middle-phase microemulsion (M) and water-rich bottom phase (B) were determined by means of electrical conductivity measurements for the amphiphile/oil/''water'' system C6H13(OC2H4)(2)OH/n-tetradecane/aqueous 10 mM NaCl at temperatures from 25 degrees C down to 12 degrees C, near the lower critical end-point temperature (T-lc = 10.4 degrees C). The M/B and B/M morphologies and their inversion hysteresis lines conformed to the previously postulated dispersion morphology diagram; that is, within experimental uncertainties, the two emulsion inversion lines in phase volume-temperature space met at a ''critical point'' that coincided with the lower critical end point for the phases. C1 W VIRGINIA UNIV,DEPT CHEM ENGN,MORGANTOWN,WV 26506. W VIRGINIA UNIV,DEPT PHYS,MORGANTOWN,WV 26506. RP Smith, DH (reprint author), US DOE,MORGANTOWN ENERGY TECHNOL CTR,POB 880,MORGANTOWN,WV 26507, USA. NR 23 TC 7 Z9 7 U1 0 U2 0 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 SN 0022-3654 J9 J PHYS CHEM-US JI J. Phys. Chem. PD OCT 31 PY 1996 VL 100 IS 44 BP 17558 EP 17562 DI 10.1021/jp9613854 PG 5 WC Chemistry, Physical SC Chemistry GA VR076 UT WOS:A1996VR07600020 ER PT J AU Trout, BL Chakraborty, AK Bell, AT AF Trout, BL Chakraborty, AK Bell, AT TI Analysis of the thermochemistry of NOx decomposition over CuZSM-5 based on quantum chemical and statistical mechanical calculations SO JOURNAL OF PHYSICAL CHEMISTRY LA English DT Article ID SELECTIVE CATALYTIC REDUCTION; NITRIC-OXIDE DECOMPOSITION; EXCHANGED ZSM-5 ZEOLITES; CU-ZSM-5 CATALYSTS; CU-ZEOLITES; NITROGEN MONOXIDE; REDOX CHEMISTRY; GASEOUS CUCL; DESORPTION; H-ZSM-5 AB CuZSM-5 is the most active catalyst known for the direct decomposition of NOx. We have performed first-principles quantum mechanical calculations to evaluate the electronic and structural properties of species adsorbed to Cu sites that might be involved in NOx decomposition, Using statistical mechanics, we have calculated Delta U degrees, Delta H degrees, and Delta G degrees of possible elementary reactions in order to evaluate the stability of adsorbates on Cu sites and the ease of their interconversion. On the basis of these calculations, we propose a reaction pathway for NOx decomposition. This scheme involves only single, isolated copper sites, is internally consistent, and is consistent with experimental observations. C1 UNIV CALIF BERKELEY,LAWRENCE BERKELEY LAB,CTR ADV MAT,DIV SCI MAT,BERKELEY,CA 94720. UNIV CALIF BERKELEY,DEPT CHEM ENGN,BERKELEY,CA 94720. OI Bell, Alexis/0000-0002-5738-4645 NR 72 TC 109 Z9 113 U1 1 U2 13 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 SN 0022-3654 J9 J PHYS CHEM-US JI J. Phys. Chem. PD OCT 31 PY 1996 VL 100 IS 44 BP 17582 EP 17592 DI 10.1021/jp961470b PG 11 WC Chemistry, Physical SC Chemistry GA VR076 UT WOS:A1996VR07600024 ER PT J AU Samoilova, RI Dikanov, SA Fionov, AV Tyryshkin, AM Lunina, EV Bowman, MK AF Samoilova, RI Dikanov, SA Fionov, AV Tyryshkin, AM Lunina, EV Bowman, MK TI Pulsed EPR study of orthophosphoric and boric acid modified gamma-alumina SO JOURNAL OF PHYSICAL CHEMISTRY LA English DT Article ID ECHO ENVELOPE-MODULATION; ELECTRON-SPIN-RESONANCE; S = 1/2; PARAMAGNETIC-RESONANCE; COMBINATION HARMONICS; DISORDERED SOLIDS; ESEEM SPECTRA; SPECTROSCOPY; PHOSPHORUS; CATALYSTS AB CW EPR, pulsed ENDOR, and one- and two-dimensional ESEEM techniques have been applied to study the influence of H3PO4 and H3BO3 acid modification of gamma-Al2O3 on the strong electron acceptor sites of gamma-Al2O3 using adsorbed anthraquinone and o-chloranil as probe molecules. After the adsorbtion, electron transfer produces free radicals at active sites on the activated gamma-Al2O3. The observed spectra are the superposition of spectra from radicals simply adsorbed on the surface and from three different paramagnetic complexes of anthraquinone with coordinatively unsaturated aluminum. The isotropic hyperfine coupling of aluminum nuclei in these complexes is similar to 2.5, 21, and 28 MHz. Treatment of gamma-Al2O3 with H3PO4 decreases the relative amounts of adsorbed radical and the complex with 2.5 MHz hyperfine coupling. The H3BO3 treatment, in contrast, gives only the complex with the 21 MHz hyperfine coupling, and its resolved EPR spectrum indicates two equivalent aluminums in this active site. The ESEEM spectra show only weak dipole-dipole interaction with P-31 and B-11 nuclei located around the paramagnetic complex. These results suggest that acid modification alters the catalytic properties by changing the number and type of catalytic sites on the surface without introducing new species. C1 PACIFIC NW LAB, MACROMOL STRUCT & DYNAM ENVIRONM MOL SCI, RICHLAND, WA 99352 USA. RUSSIAN ACAD SCI, INST CHEM KINET & COMBUST, NOVOSIBIRSK 630090, RUSSIA. MOSCOW MV LOMONOSOV STATE UNIV, DEPT CHEM, MOSCOW 119899, RUSSIA. RI Tyryshkin, Alexei/A-5219-2008; Bowman, Michael/F-4265-2011 OI Bowman, Michael/0000-0003-3464-9409 NR 51 TC 16 Z9 17 U1 0 U2 2 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 SN 0022-3654 J9 J PHYS CHEM-US JI J. Phys. Chem. PD OCT 31 PY 1996 VL 100 IS 44 BP 17621 EP 17629 DI 10.1021/jp961873b PG 9 WC Chemistry, Physical SC Chemistry GA VR076 UT WOS:A1996VR07600029 ER PT J AU Slominski, W Szwed, J AF Slominski, W Szwed, J TI QCD structure of leptons SO PHYSICS LETTERS B LA English DT Article ID PHOTON STRUCTURE; HARD SCATTERING; CROSS-SECTIONS; PHOTOPRODUCTION; HERA; APPROXIMATION; BOSONS AB The QCD structure of the electron is defined and calculated. The leading order splitting functions are extracted, showing an important contribution from gamma-Z interference. Leading logarithmic QCD evolution equations are constructed and solved in the asymptotic region where log(2) behaviour of the parton densities is observed. Corrections to the naive evolution procedure are demonstrated. Possible applications with clear manifestation of ''resolved'' photon and weak bosons are discussed. C1 JAGIELLONIAN UNIV,INST COMP SCI,PL-30059 KRAKOW,POLAND. RP Slominski, W (reprint author), BROOKHAVEN NATL LAB,DEPT PHYS,UPTON,NY 11973, USA. NR 20 TC 10 Z9 10 U1 0 U2 0 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0370-2693 J9 PHYS LETT B JI Phys. Lett. B PD OCT 31 PY 1996 VL 387 IS 4 BP 861 EP 866 DI 10.1016/0370-2693(96)01099-4 PG 6 WC Astronomy & Astrophysics; Physics, Nuclear; Physics, Particles & Fields SC Astronomy & Astrophysics; Physics GA VN801 UT WOS:A1996VN80100031 ER PT J AU Hersman, L Maurice, P Sposito, G AF Hersman, L Maurice, P Sposito, G TI Iron acquisition from hydrous Fe(III)-oxides by an aerobic Pseudomonas sp SO CHEMICAL GEOLOGY LA English DT Article ID YEAST SACCHAROMYCES-CEREVISIAE; FERRIC IRON; DISSIMILATORY FE(III); ANAEROBIC SEDIMENTS; REDUCTION; SIDEROPHORES; DISSOLUTION; MANGANESE; URANIUM; OXIDES AB Iron is a metabolic requirement of living systems, yet iron is very insoluble in aerobic, neutral environments. Therefore, the amount of iron in solution under these conditions is not sufficient to meet the nutrient requirements of microorganisms. It has been assumed that microorganisms acquire iron in these environments through the use of specific iron chelating compounds called siderophores. Interestingly, there is little quantitative data in the literature to support this hypothesis. Our studies were initiated to investigate the mechanism(s) used by an aerobic microorganism to acquire iron from a relatively insoluble iron oxide. When iron was supplied in the form of hematite, a Pseudomonas sp. was able to achieve moderate growth, as compared to growth on FeEDTA. Analysis using high-performance liquid chromatography (HPLC) of the metabolic products of this species showed significant differences between growth on hematite as compared to FeEDTA. The results of these experiments will be discussed in terms of our current knowledge of microbial enhanced iron dissolution, and compared to abiotic dissolution rates. C1 KENT STATE UNIV,DEPT GEOL,KENT,OH 44242. UNIV CALIF BERKELEY,DEPT ENVIRONM SCI & POLICY & MANAGEMENT,BERKELEY,CA 94720. RP Hersman, L (reprint author), LOS ALAMOS NATL LAB,DIV LIFE SCI,LOS ALAMOS,NM 87545, USA. NR 33 TC 48 Z9 55 U1 2 U2 6 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0009-2541 J9 CHEM GEOL JI Chem. Geol. PD OCT 30 PY 1996 VL 132 IS 1-4 BP 25 EP 31 DI 10.1016/S0009-2541(96)00038-1 PG 7 WC Geochemistry & Geophysics SC Geochemistry & Geophysics GA VR951 UT WOS:A1996VR95100005 ER PT J AU Maurice, P Forsythe, J Hersman, L Sposito, G AF Maurice, P Forsythe, J Hersman, L Sposito, G TI Application of atomic-force microscopy to studies of microbial interactions with hydrous Fe(III)-oxides SO CHEMICAL GEOLOGY LA English DT Article ID MINERAL SURFACES; HEMATITE; DISSOLUTION; ACID AB We are using atomic-force microscopy (AFM), to address the interactions of a Pseudomonas sp. aerobic soil microbe with Fe(III)-(hydr)oxides. Research results to date show that AFM is a viable technique for in-situ and ex-situ imaging of bacteria attached to mineral surfaces. Delicate microbial structures and mineral surface microtopographies are readily accessible. However, sample preparation has proven to be crucial. For example, we found that an organic extractant used to separate bacteria from particle surfaces left a residue that could be mistaken for dissolution features in AFM images. Additionally, care must be taken to image samples in numerous locations and under a wide variety of conditions. The need for extensive imaging was reinforced by our observations that most reacted particles had no obvious dissolution features, but a small fraction of particles were extensively eroded. Hence, microbe-Fe(III)-(hydr)oxide interactions lead to enhanced dissolution, but the dissolution process is heterogeneous in nature. Thus, although AFM imaging of such complex systems is difficult and time-consuming, a painstaking approach is needed. C1 LOS ALAMOS NATL LAB,LOS ALAMOS,NM 87545. UNIV CALIF BERKELEY,DEPT ENVIRONM SCI & POLICY & MANAGEMENT,BERKELEY,CA 94720. RP Maurice, P (reprint author), KENT STATE UNIV,DEPT GEOL,KENT,OH 44242, USA. NR 28 TC 18 Z9 21 U1 3 U2 6 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0009-2541 J9 CHEM GEOL JI Chem. Geol. PD OCT 30 PY 1996 VL 132 IS 1-4 BP 33 EP 43 DI 10.1016/S0009-2541(96)00039-3 PG 11 WC Geochemistry & Geophysics SC Geochemistry & Geophysics GA VR951 UT WOS:A1996VR95100006 ER PT J AU Newman, BD Norman, DI Gundimeda, M Levy, SS AF Newman, BD Norman, DI Gundimeda, M Levy, SS TI Understanding the genesis of nonmarine calcite deposits through quadrupole mass spectrometric analysis of fluid inclusion gases SO CHEMICAL GEOLOGY LA English DT Article AB Quadrupole mass spectroscopy was used to analyze fluid inclusion volatiles in different types of nonmarine calcites including travertines, phreatic calcretes, hydrothermal vein calcites, and pedogenic calcites, The objectives of the study were to determine if there were any diagnostic or characteristic differences between the inclusion volatiles from the different calcites, and to see if the quadrupole results could be used to understand the processes and environmental conditions that controlled calcite precipitation. The calcites formed under saturated conditions have water-dominated inclusions with well-constrained N-2/Ar ratios and either CO2 or N-2 as the dominant inclusion gas. Some calcretes and travertines were exceptions to the above characteristics, but it is likely that these were subjected to secondary precipitation in an environment different from the primary precipitation phase. Results for the pedogenic calcites are quite different from calcites formed in water-saturated systems, Pedogenic calcites have gas-dominated (water-poor) inclusions, unexpectedly large CH4 contents, low O-2 contents, and highly variable N-2/Ar ratios. The dominance of CH4 and low O-2 contents in the pedogenic calcites suggest that anaerobic conditions occurred during at least part of the precipitation process. Scanning electron microscope (SEM) examination of the pedogenic calcites shows fungal remains, bacteria-like forms, and gels from fungi or plant roots. The quadrupole and SEM results suggest pedogenic calcite precipitation occurred as a result of aerobic and, ultimately, anaerobic microbial decay processes. C1 NEW MEXICO INST MIN & TECHNOL,EARTH & ENVIRONM SCI DEPT,SOCORRO,NM 87801. LOS ALAMOS NATL LAB,GEOL & GEOCHEM GRP,LOS ALAMOS,NM 87545. RP Newman, BD (reprint author), LOS ALAMOS NATL LAB,ENVIRONM SCI GRP,LOS ALAMOS,NM 87545, USA. NR 14 TC 8 Z9 8 U1 0 U2 3 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0009-2541 J9 CHEM GEOL JI Chem. Geol. PD OCT 30 PY 1996 VL 132 IS 1-4 BP 205 EP 213 DI 10.1016/S0009-2541(96)00057-5 PG 9 WC Geochemistry & Geophysics SC Geochemistry & Geophysics GA VR951 UT WOS:A1996VR95100024 ER PT J AU Halsey, TC Anderson, RA Martin, JE AF Halsey, TC Anderson, RA Martin, JE TI The rotary electrorheological effect SO INTERNATIONAL JOURNAL OF MODERN PHYSICS B LA English DT Article; Proceedings Paper CT 5th International Conference on Electro-Rheological Fluids, Magneto-Rheological Suspensions and Associated Technology CY JUL, 1995 CL SHEFFIELD, ENGLAND ID FLUIDS AB The viscous response of electrorheological fluids is usually manipulated through the use of DC or uniaxial AC electric fields. The result is that fibrillated structures parallel to the field form in a quiescent fluid; the distortion of such structures in a flow determines the enhanced viscous response, at least at low and moderate flow rates. We have conducted preliminary studies of electrorheological response in a different field configuration-a rotating electric field. With respect to the uniaxial AC case, there are two new developments in this type of field. The structures formed are disk-like, in the plane of the rotating field. Furthermore, the structures rotate either with or against the field, depending on the dielectric or conductivity contrast with the surrounding fluid. C1 SANDIA NATL LABS,ADV MAT PHYS DIV,ALBUQUERQUE,NM 87185. RP Halsey, TC (reprint author), EXXON RES & ENGN CO,ROUTE 22 E,ANNANDALE,NJ 08801, USA. NR 10 TC 21 Z9 21 U1 0 U2 4 PU WORLD SCIENTIFIC PUBL CO PTE LTD PI SINGAPORE PA JOURNAL DEPT PO BOX 128 FARRER ROAD, SINGAPORE 9128, SINGAPORE SN 0217-9792 J9 INT J MOD PHYS B JI Int. J. Mod. Phys. B PD OCT 30 PY 1996 VL 10 IS 23-24 BP 3019 EP 3027 DI 10.1142/S021797929600146X PG 9 WC Physics, Applied; Physics, Condensed Matter; Physics, Mathematical SC Physics GA VR995 UT WOS:A1996VR99500021 ER PT J AU Martin, JE Odinek, A AF Martin, JE Odinek, A TI Light scattering studies of an electrorheological fluid in oscillatory shear SO INTERNATIONAL JOURNAL OF MODERN PHYSICS B LA English DT Article; Proceedings Paper CT 5th International Conference on Electro-Rheological Fluids, Magneto-Rheological Suspensions and Associated Technology CY JUL, 1995 CL SHEFFIELD, ENGLAND ID VISCOELASTIC RESPONSE; STEADY-SHEAR; DEPENDENCE AB We have conducted a real time, two-dimensional light scattering study of the nonlinear dynamics of field-induced structures in an electrorheological fluid subjected to oscillatory shear. We have developed a kinetic chain model of the observed dynamics by considering the response of a fragmenting/aggregating particle chain to the prevailing hydrodynamic and electrostatic forces. This structural theory is then used to describe the nonlinear rheology of ER fluids. RP Martin, JE (reprint author), SANDIA NATL LABS,ADV MAT PHYS DIV,POB 5800,ALBUQUERQUE,NM 87185, USA. NR 11 TC 1 Z9 1 U1 0 U2 0 PU WORLD SCIENTIFIC PUBL CO PTE LTD PI SINGAPORE PA JOURNAL DEPT PO BOX 128 FARRER ROAD, SINGAPORE 9128, SINGAPORE SN 0217-9792 J9 INT J MOD PHYS B JI Int. J. Mod. Phys. B PD OCT 30 PY 1996 VL 10 IS 23-24 BP 3257 EP 3266 DI 10.1142/S0217979296001707 PG 10 WC Physics, Applied; Physics, Condensed Matter; Physics, Mathematical SC Physics GA VR995 UT WOS:A1996VR99500045 ER PT J AU Wen, SJ Richardson, TJ Ghantous, DI Streibel, KA Ross, PN Cairns, EJ AF Wen, SJ Richardson, TJ Ghantous, DI Streibel, KA Ross, PN Cairns, EJ TI FTIR characterization of PEO+LiN(CF3SO2)(2) electrolytes (vol 408, pg 113, 1996) SO JOURNAL OF ELECTROANALYTICAL CHEMISTRY LA English DT Correction, Addition C1 ERNEST ORLANDO LAWRENCE BERKELEY NATL LAB,DIV MAT SCI,BERKELEY,CA 94720. ERNEST ORLANDO LAWRENCE BERKELEY NATL LAB,DIV ENERGY & ENVIRONM,BERKELEY,CA 94720. RI Cairns, Elton/E-8873-2012 OI Cairns, Elton/0000-0002-1179-7591 NR 1 TC 8 Z9 8 U1 0 U2 2 PU ELSEVIER SCIENCE SA LAUSANNE PI LAUSANNE 1 PA PO BOX 564, 1001 LAUSANNE 1, SWITZERLAND SN 0022-0728 J9 J ELECTROANAL CHEM JI J. Electroanal. Chem. PD OCT 30 PY 1996 VL 415 IS 1-2 BP 197 EP 197 DI 10.1016/S0022-0728(96)01010-8 PG 1 WC Chemistry, Analytical; Electrochemistry SC Chemistry; Electrochemistry GA VR841 UT WOS:A1996VR84100029 ER PT J AU Jackson, K Fulton, JL AF Jackson, K Fulton, JL TI Microemulsions in supercritical hydrochlorofluorocarbons SO LANGMUIR LA English DT Article ID IN-OIL MICROEMULSIONS; X-RAY-SCATTERING; CARBON-DIOXIDE; REVERSE MICELLES; PHASE-BEHAVIOR; DIPOLE-MOMENTS; WATER; FLUIDS; AGGREGATION; ETHANE AB We report the properties of sodium bis(2-ethylhexyl) sulfosuccinate (AOT) microemulsions formed in supercritical hydrochlorofluorocarbons (HCFCs), hydrofluorocarbons, and fluorocarbons. The fluids used in this study include compounds that are of low toxicity and flammability and that are expected to remain environmentally acceptable well into the next century (e.g., 1,1,1,2-tetrafluoroethane (R134a) and chlorodifluoromethane (R22)). We show that it is possible to form a water-in-oil type of microemulsion in a low molecular weight HCFC (R22). In addition to these HCFCs, we also review the ability to form microemulsions in 14 other fluids (ethane, propene, propane, n-butane, n-pentane, n-hexane, isobutane, isooctane, difluoromethane, trifluoromethane, hexafluoroethane, sulfur hexafluoride, xenon, and carbon dioxide) at conditions just above or below the critical point (0.75 < T/T-c < 1.1) of the solvent. Due to the proximity of these liquids to the critical point, it is possible to make substantial changes in the densities of these solvents with modest changes in pressure. These 16 fluids have contrasting physical and chemical properties. We find that the parameter which universally predicts the ability of these solvents to form a microemulsion is the high-frequency dielectric constant (UV-vis light frequencies). This solvent dielectric constant is the parameter that governs the magnitude of the intermicellar van der Waals attractive forces but may also be relevant to the short-range attractive forces(surfactant tail to surfactant tail) that possibly control the phase behavior of these systems. We report extensively the phase behavior of AOT and didodecyldimethylammonium bromide microemulsions formed in a supercritical HCFC, R22. Microemulsions formed in supercritical R22 were demonstrated to have strongly density-dependent maximum molar water-to-surfactant ratios, W-0. When the pressure is increased from 100 to 400 bar, W-0 increases from 5 to 50, making the solvency of the polar or ionic species in these systems highly pressure tunable. It was also shown that HCFC-based microemulsions are capable of solubilizing high molecular weight proteins, such as cytochrome c, which demonstrates their usefulness for separations from aqueous solutions. We show that microemulsions in HCFCs are practical alternatives to other fluids, such as supercritical carbon dioxide. C1 PACIFIC NW LAB, DEPT CHEM & MAT SCI, RICHLAND, WA 99352 USA. NR 56 TC 23 Z9 25 U1 1 U2 11 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 0743-7463 J9 LANGMUIR JI Langmuir PD OCT 30 PY 1996 VL 12 IS 22 BP 5289 EP 5295 DI 10.1021/la960210i PG 7 WC Chemistry, Multidisciplinary; Chemistry, Physical; Materials Science, Multidisciplinary SC Chemistry; Materials Science GA VQ414 UT WOS:A1996VQ41400009 ER PT J AU Quinones, I Guiochon, G AF Quinones, I Guiochon, G TI Isotherm models for localized monolayers with lateral interactions. Application to single-component and competitive adsorption data obtained in RP-HPLC SO LANGMUIR LA English DT Article ID LIQUID-CHROMATOGRAPHIC SORBENTS; OVERLOADED ELUTION PROFILES; BAND PROFILES; FRONTAL CHROMATOGRAPHY; GRADIENT ELUTION; ENANTIOMERS; SILICA; PREDICTION; SEPARATION; CELLULOSE AB Single-component and competitive adsorption data of 2-phenylethanol and 3-phenylpropanol on ODS-silica with methanol-water as the mobile phase, which had been previously reported, were reinterpreted. These data were fitted to several isotherm models derived from statistical thermodynamics which consider lateral adsorbate-adsorbate interactions on homogeneous surfaces: the Fowler, Ruthven, and Moreau et al. models. The single-component Kiselev model for specific lateral interactions was extended to account for the competitive adsorption of binary mixtures and for the finite or infinite dimension of the adsorbed associates. These last models were tested using the same set of experimental data. A comparison was made regarding the ability of these models to predict mixed equilibria using only the identified parameters of the single-component isotherms. In this regard, the best results were obtained with the Kiselev model, which considers the formation of both binary and ternary associates on the surface. C1 DEPT TECNOL,CTR QUIM FARMACEUT,HAVANA 11600,CUBA. OAK RIDGE NATL LAB,DIV CHEM & ANALYT SCI,OAK RIDGE,TN 37831. NR 40 TC 22 Z9 22 U1 0 U2 7 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 SN 0743-7463 J9 LANGMUIR JI Langmuir PD OCT 30 PY 1996 VL 12 IS 22 BP 5433 EP 5443 DI 10.1021/la9603333 PG 11 WC Chemistry, Multidisciplinary; Chemistry, Physical; Materials Science, Multidisciplinary SC Chemistry; Materials Science GA VQ414 UT WOS:A1996VQ41400029 ER PT J AU Dowben, PA McIlroy, DN Zhang, JD Ruhl, E AF Dowben, PA McIlroy, DN Zhang, JD Ruhl, E TI When are thin films of metals metallic .3. SO MATERIALS SCIENCE AND ENGINEERING A-STRUCTURAL MATERIALS PROPERTIES MICROSTRUCTURE AND PROCESSING LA English DT Article; Proceedings Paper CT International Conference on Nano-Clusters and Granular Materials CY SEP 19-22, 1995 CL SENDAI, JAPAN DE nonmetallic behavior; nonmetal to metal transition; divalent thin films ID SURFACE-PLASMON DISPERSION; ELECTRONIC-SHELL STRUCTURE; VAN-DER-WAALS; MERCURY CLUSTERS; NONMETAL TRANSITION; SIZE DEPENDENCE; EFFECTIVE-MASS; HGN CLUSTERS; RARE-GAS; VANDERWAALS AB A large amount of experimental information has indicated that very thin films of metallic elements can exhibit nonmetallic behavior. even on metal substrates. These films undergo a gradual nonmetal to metal transition with increasing film density or thickness. The nonmetallic behavior can be related to electron localization due to strong electron-electron correlation in low dimensional systems, as indicated by the strong, enhancement of electron efficient mass. The evolution in the electronic structure associated with the nonmetal to metal transition bears a striking resemblance to the behavior observed for free metal clusters. Part I [1]. outlined the general concepts of a nonmetal to metal transition in a thin film, while part II [2] critically examined three examples of nonmetal to metal transitions for thin film overlayers. This paper will discuss some surprising correlations between the electronic structure of divalent thin films on metal substrates and divalent metal clusters that have been reported in the literature. C1 UNIV NEBRASKA,CTR MAT RES & ANAL,BEHLEN LAB PHYS,LINCOLN,NE 68588. OAK RIDGE NATL LAB,DIV SOLID STATE,OAK RIDGE,TN 37831. UNIV MAINZ,INST PHYS,D-55099 MAINZ,GERMANY. RP Dowben, PA (reprint author), UNIV NEBRASKA,DEPT PHYS,LINCOLN,NE 68588, USA. NR 61 TC 5 Z9 5 U1 0 U2 0 PU ELSEVIER SCIENCE SA LAUSANNE PI LAUSANNE PA PO BOX 564, 1001 LAUSANNE, SWITZERLAND SN 0921-5093 J9 MAT SCI ENG A-STRUCT JI Mater. Sci. Eng. A-Struct. Mater. Prop. Microstruct. Process. PD OCT 30 PY 1996 VL 217 BP 258 EP 264 DI 10.1016/S0921-5093(96)10290-2 PG 7 WC Nanoscience & Nanotechnology; Materials Science, Multidisciplinary; Metallurgy & Metallurgical Engineering SC Science & Technology - Other Topics; Materials Science; Metallurgy & Metallurgical Engineering GA VY090 UT WOS:A1996VY09000061 ER PT J AU Anglin, J Habib, S AF Anglin, J Habib, S TI Classical dynamics for linear systems: The case of quantum Brownian motion SO MODERN PHYSICS LETTERS A LA English DT Article ID INTEGRAL APPROACH; DECOHERENCE; MECHANICS AB The dynamics of linear quantum systems is classical in the Wigner representation, yet linear problems are often analyzed using such general techniques as influence functionals and Bogoliubov transformations. In fact, the classical equations of motion provide a simpler and more intuitive formalism for these systems. As an important example, we show that quantum Brownian dynamics in the independent oscillator model is described directly and completely by a c-number Langevin equation. The corresponding Fokker-Planck equation is always local in time, regardless of the environmental spectrum. RP Anglin, J (reprint author), LOS ALAMOS NATL LAB,DIV THEORET,MAIL STOP B288,LOS ALAMOS,NM 87545, USA. NR 16 TC 12 Z9 13 U1 0 U2 1 PU WORLD SCIENTIFIC PUBL CO PTE LTD PI SINGAPORE PA JOURNAL DEPT PO BOX 128 FARRER ROAD, SINGAPORE 9128, SINGAPORE SN 0217-7323 J9 MOD PHYS LETT A JI Mod. Phys. Lett. A PD OCT 30 PY 1996 VL 11 IS 32-33 BP 2655 EP 2662 DI 10.1142/S0217732396002654 PG 8 WC Physics, Nuclear; Physics, Particles & Fields; Physics, Mathematical SC Physics GA VT293 UT WOS:A1996VT29300010 ER PT J AU Book, GW Carter, WB Polley, TA Kozaczek, KJ AF Book, GW Carter, WB Polley, TA Kozaczek, KJ TI Preparation of YBa2Cu3Ox superconducting thin films via combustion chemical vapor deposition SO THIN SOLID FILMS LA English DT Article DE superconductivity; chemical vapour deposition; yttrium ID OXIDE-FILMS; SYSTEM AB YBa2Cu3Ox (YBCO) thin films were prepared by combustion chemical vapor deposition. As-deposited films on single-crystal (100) MgO substrates showed highly oriented c-axis up-growth and displayed the onset of a superconducting transition at 84 K with zero resistance obtained at 78 K after annealing in pure oxygen. Pole figures of the YBCO films on (100) MgO showed two in-plane alignment orientations of the film with respect to the substrate. The YBCO [100] and [110] were aligned with the MgO [100]. YBCO films were also deposited on roll-textured polycrystalline silver at temperatures between 1120-1220 K and di splayed c axis up-growth. The rolling texture of silver was not strong enough to induce detectable in-plane preferential growth of the YBCO. Metal nitrate salt solution compositions differed from oxide film compositions. To obtain a film composition of near 1:2:3 on MgO, a solution composition of 1:1:0.9 was necessary. C1 OAK RIDGE NATL LAB,HIGH TEMP MAT LAB,OAK RIDGE,TN 37831. RP Book, GW (reprint author), GEORGIA INST TECHNOL,SCH MAT SCI & ENGN,ATLANTA,GA 30332, USA. NR 12 TC 6 Z9 6 U1 0 U2 2 PU ELSEVIER SCIENCE SA LAUSANNE PI LAUSANNE PA PO BOX 564, 1001 LAUSANNE, SWITZERLAND SN 0040-6090 J9 THIN SOLID FILMS JI Thin Solid Films PD OCT 30 PY 1996 VL 287 IS 1-2 BP 32 EP 35 DI 10.1016/S0040-6090(96)08760-3 PG 4 WC Materials Science, Multidisciplinary; Materials Science, Coatings & Films; Physics, Applied; Physics, Condensed Matter SC Materials Science; Physics GA VY504 UT WOS:A1996VY50400005 ER PT J AU Cardinale, GF Howitt, DG Clift, WM McCarty, KF Medlin, DL Mirkarimi, PB Moody, NR AF Cardinale, GF Howitt, DG Clift, WM McCarty, KF Medlin, DL Mirkarimi, PB Moody, NR TI Micromachined silicon cantilever beams for thin-film stress measurement SO THIN SOLID FILMS LA English DT Article DE silicon; stress; etching; Auger electron spectroscopy ID FRACTURE AB We present a technique for micromachining silicon cantilever beams for thin-him stress measurement. The silicon microbeams were fabricated using a two-step etch process with potassium hydroxide (KOH) as the anisotropic etchant. The final beam geometry is optimized by using a 45% KOH solution and double-side polished silicon wafers as the starting material. We demonstrate a cleaning procedure that produces clean microbeam surfaces as verified by Auger electron spectroscopy. The effects of KOH concentration and temperature on the etch rate, etch rate sensitivity, and silicon surface roughness is discussed. We present results of compressive stress in boron nitride films grown by an ion-assisted process. C1 SANDIA NATL LABS,LIVERMORE,CA 95550. RP Cardinale, GF (reprint author), UNIV CALIF DAVIS,DEPT CHEM ENGN & MAT SCI,DAVIS,CA 95616, USA. RI McCarty, Kevin/F-9368-2012 OI McCarty, Kevin/0000-0002-8601-079X NR 12 TC 12 Z9 12 U1 0 U2 0 PU ELSEVIER SCIENCE SA LAUSANNE PI LAUSANNE PA PO BOX 564, 1001 LAUSANNE, SWITZERLAND SN 0040-6090 J9 THIN SOLID FILMS JI Thin Solid Films PD OCT 30 PY 1996 VL 287 IS 1-2 BP 214 EP 219 DI 10.1016/S0040-6090(96)08754-8 PG 6 WC Materials Science, Multidisciplinary; Materials Science, Coatings & Films; Physics, Applied; Physics, Condensed Matter SC Materials Science; Physics GA VY504 UT WOS:A1996VY50400034 ER PT J AU Shen, YR AF Shen, YR TI A few selected applications of surface nonlinear optical spectroscopy SO PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF THE UNITED STATES OF AMERICA LA English DT Article ID SUM-FREQUENCY-GENERATION; LIQUID NORMAL-ALKANES; VIBRATIONAL-ENERGY RELAXATION; METAL-ELECTROLYTE INTERFACE; 2ND-HARMONIC GENERATION; ETHYLENE HYDROGENATION; VAPOR INTERFACE; WATER INTERFACE; METHYL THIOLATE; STRETCH MODE AB As a second-order nonlinear optical process, sum-frequency generation is highly surface-specific and accordingly has been developed into a very powerful and versatile surface spectroscopic tool. It has found many unique applications in different disciplines and thus provided many exciting new research opportunities in surface and surface-related science. Selected examples are discussed here to illustrate the power of the technique. C1 LAWRENCE BERKELEY NATL LAB, DIV MAT SCI, BERKELEY, CA 94720 USA. RP Shen, YR (reprint author), UNIV CALIF BERKELEY, DEPT PHYS, BERKELEY, CA 94720 USA. NR 74 TC 78 Z9 78 U1 2 U2 25 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 OCT 29 PY 1996 VL 93 IS 22 BP 12104 EP 12111 DI 10.1073/pnas.93.22.12104 PG 8 WC Multidisciplinary Sciences SC Science & Technology - Other Topics GA VP937 UT WOS:A1996VP93700011 PM 8901540 ER PT J AU Hale, TC Telschow, K AF Hale, TC Telschow, K TI Optical lock-in vibration detection using photorefractive frequency domain processing SO APPLIED PHYSICS LETTERS LA English DT Article ID CRYSTALS AB optical method for vibration detection and spectral analysis based on photorefractive frequency domain processing is presented. The method utilizes the photorefractive effect in selected materials (bismuth silicon oxide) for synchronous detection of the optical phase shift of an object beam scattered from a vibrating specimen surface. Four-wave mixing and lock-in detection allow measurement of both the vibration amplitude and phase. Narrow-bandwidth detection can be achieved at frequencies from the photorefractive response limit to the reciprocal of the photoinduced carrier recombination time. (C) 1996 American Institute of Physics. RP Hale, TC (reprint author), IDAHO NATL ENGN LAB,IDAHO FALLS,ID 83415, USA. NR 7 TC 13 Z9 13 U1 0 U2 0 PU AMER INST PHYSICS PI WOODBURY PA CIRCULATION FULFILLMENT DIV, 500 SUNNYSIDE BLVD, WOODBURY, NY 11797-2999 SN 0003-6951 J9 APPL PHYS LETT JI Appl. Phys. Lett. PD OCT 28 PY 1996 VL 69 IS 18 BP 2632 EP 2634 DI 10.1063/1.117541 PG 3 WC Physics, Applied SC Physics GA VP265 UT WOS:A1996VP26500004 ER PT J AU Auciello, O Krauss, AR Im, J Gruen, DM Irene, EA Chang, RPH McGuire, GE AF Auciello, O Krauss, AR Im, J Gruen, DM Irene, EA Chang, RPH McGuire, GE TI Studies of film growth processes and surface structural characterization of ferroelectric memory-compatible SrBi2Ta2O9 layered perovskites via in situ, real-time ion-beam analysis SO APPLIED PHYSICS LETTERS LA English DT Article ID IN-SITU; OF-FLIGHT AB In situ, real-time studies of layered perovskite SrBi2Ta2O9 (SBT) film growth processes were performed using a time-of-flight ion scattering and recoil spectroscopy (TOF ISARS) technique. These studies revealed two important features related to the synthesis of SET films via ion-beam sputter-deposition, namely: (a) atomic oxygen originating from a multicomponent SET target during the sputtering process is incorporated in the growing film more efficiently than molecular oxygen; and (b) the SET surface appears to be terminated in an incomplete (Bi2O2)(2+) layer with a top surface of oxygen atoms, which may be responsible for the high resistance to polarization fatigue exhibited by Pt/SBT/Pt capacitors. (C) 1996 American Institute of Physics. C1 ARGONNE NATL LAB,DIV CHEM,ARGONNE,IL 60439. UNIV N CAROLINA,DEPT CHEM,CHAPEL HILL,NC 27599. NORTHWESTERN UNIV,DEPT MAT SCI,EVANSTON,IL 60208. MICROELECT CTR N CAROLINA,ELECT TECHNOL DIV,RES TRIANGLE PK,NC 27709. RP Auciello, O (reprint author), ARGONNE NATL LAB,DIV MAT SCI,9700 S CASS AVE,ARGONNE,IL 60439, USA. RI Chang, R.P.H/B-7505-2009 NR 9 TC 27 Z9 27 U1 0 U2 2 PU AMER INST PHYSICS PI WOODBURY PA CIRCULATION FULFILLMENT DIV, 500 SUNNYSIDE BLVD, WOODBURY, NY 11797-2999 SN 0003-6951 J9 APPL PHYS LETT JI Appl. Phys. Lett. PD OCT 28 PY 1996 VL 69 IS 18 BP 2671 EP 2673 DI 10.1063/1.117554 PG 3 WC Physics, Applied SC Physics GA VP265 UT WOS:A1996VP26500017 ER PT J AU Fischer, S Wetzel, C Hansen, WL BourretCourchesne, ED Meyer, BK Haller, EE AF Fischer, S Wetzel, C Hansen, WL BourretCourchesne, ED Meyer, BK Haller, EE TI Properties of GaN grown at high rates on sapphire and on 6H-SiC SO APPLIED PHYSICS LETTERS LA English DT Article ID VAPOR-PHASE EPITAXY; OPTICAL-PROPERTIES; CRYSTAL-GROWTH; LAYERS; SUBSTRATE AB Thick GaN films were deposited with growth rates as high as 250 mu m/h by the direct reaction of ammonia and gallium vapor at 1240 degrees C, The characteristics of our films are comparable to those of typical thin films grown by metal organic chemical vapor deposition or molecular beam epitaxy. Grown under identical conditions, films on (0001) sapphire and on (0001) 6H-SiC were compared in terms of their structural and optical properties. Considering x-ray rocking curve full width at half-maximum (FWHM: 420 arcsec), photoluminescence linewidths of the excitons (FWHM: 3 meV at 6 K and 100 meV at 300 K), free electron concentration, defect related luminescence, and the homogeneity of these properties, we find superior values for films grown on SiC. For both substrate materials we find an optimum growth rate window of 40-80 mu m/h. (C) 1996 American Institute of Physics. C1 UNIV CALIF BERKELEY,BERKELEY,CA 94720. UNIV GIESSEN,INST PHYS,D-35392 GIESSEN,GERMANY. RP Fischer, S (reprint author), LAWRENCE BERKELEY LAB,BERKELEY,CA 94720, USA. RI Wetzel, Christian/O-4017-2014 OI Wetzel, Christian/0000-0002-6055-0990 NR 24 TC 34 Z9 35 U1 3 U2 6 PU AMER INST PHYSICS PI WOODBURY PA CIRCULATION FULFILLMENT DIV, 500 SUNNYSIDE BLVD, WOODBURY, NY 11797-2999 SN 0003-6951 J9 APPL PHYS LETT JI Appl. Phys. Lett. PD OCT 28 PY 1996 VL 69 IS 18 BP 2716 EP 2718 DI 10.1063/1.117688 PG 3 WC Physics, Applied SC Physics GA VP265 UT WOS:A1996VP26500032 ER PT J AU Wei, SH Zunger, A AF Wei, SH Zunger, A TI Valence band splittings and band offsets of AlN, GaN, and InN SO APPLIED PHYSICS LETTERS LA English DT Article ID II-VI SEMICONDUCTORS; STRUCTURAL-PROPERTIES; GALLIUM NITRIDE; ELECTRONIC-STRUCTURE; ORBITALS; PRESSURE; ALLOYS AB First-principles electronic structure calculations on wurtzite AlN, GaN, and InN reveal crystal-field splitting parameters Delta(CF) of -217, 42, and 41 meV, respectively, and spin-orbit splitting parameters Delta(0) of 19, 13, and 1 meV, respectively. In the zinc blende structure Delta(CF) = 0 and Delta(0) are 19, 15, and 6 meV, respectively. The unstrained AlN/GaN, GaN/InN, and AlN/InN valence band offsets for the wurtzite (zinc blende) materials are 0.81 (0.84), 0.48 (0.26), and 1.25 (1.04) eV, respectively. The trends in these spectroscopic quantities are discussed and recent experimental findings are analyzed in light of these predictions. (C) 1996 American Institute of Physics. RP Wei, SH (reprint author), NATL RENEWABLE ENERGY LAB, GOLDEN, CO 80401 USA. RI Zunger, Alex/A-6733-2013 NR 35 TC 253 Z9 253 U1 9 U2 52 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 OCT 28 PY 1996 VL 69 IS 18 BP 2719 EP 2721 DI 10.1063/1.117689 PG 3 WC Physics, Applied SC Physics GA VP265 UT WOS:A1996VP26500033 ER PT J AU Lester, LF Brown, JM Ramer, JC Zhang, L Hersee, SD Zolper, JC AF Lester, LF Brown, JM Ramer, JC Zhang, L Hersee, SD Zolper, JC TI Nonalloyed Ti/Al ohmic contacts to n-type GaN using high-temperature premetallization anneal SO APPLIED PHYSICS LETTERS LA English DT Article ID RESISTANCE AB On Si-implanted n-type GaN, a nonalloyed Ti/Al metallization has been found to form an Ohmic contact that has a specific contact resistance as low as 1.0 x 10(-5) Omega cm(2). The Ohmic character is believed to be caused by the 1120 degrees C implant activation anneal which generates nitrogen vacancies that leave the surface heavily n type. This theory is indirectly confirmed on unimplanted n-type GaN by comparing the r(c) of nonalloyed Ti/Al on unannealed GaN with that of nonalloyed Ti/Al on 1120 degrees C annealed GaN. The former has rectifying electrical characteristics, while the latter forms an Ohmic contact with an r(c) = 1.3 x 10(-3) Omega cm(2). (C) 1996 American Institute of Physics. C1 SANDIA NATL LABS,ALBUQUERQUE,NM 87185. RP Lester, LF (reprint author), UNIV NEW MEXICO,CTR HIGH TECHNOL MAT,EECE BLDG,ROOM 125,ALBUQUERQUE,NM 87131, USA. NR 14 TC 74 Z9 76 U1 4 U2 10 PU AMER INST PHYSICS PI WOODBURY PA CIRCULATION FULFILLMENT DIV, 500 SUNNYSIDE BLVD, WOODBURY, NY 11797-2999 SN 0003-6951 J9 APPL PHYS LETT JI Appl. Phys. Lett. PD OCT 28 PY 1996 VL 69 IS 18 BP 2737 EP 2739 DI 10.1063/1.117695 PG 3 WC Physics, Applied SC Physics GA VP265 UT WOS:A1996VP26500039 ER PT J AU Salieres, P Ditmire, T Perry, MD LHuillier, A Lewenstein, M AF Salieres, P Ditmire, T Perry, MD LHuillier, A Lewenstein, M TI Angular distributions of high-order harmonics generated by a femtosecond laser SO JOURNAL OF PHYSICS B-ATOMIC MOLECULAR AND OPTICAL PHYSICS LA English DT Article ID SPATIAL PROFILES; FIELDS AB We present a systematic study of the angular distributions of high-order harmonics generated with a femtosecond Cr:LiSrAlF6 laser. We investigate the influence of different parameters, namely laser intensity, nonlinear order, nature of the gas and position of the laser focus relative to the generating medium. We show that when the laser is focused before the atomic medium, harmonics with regular spatial profiles can be generated with reasonable conversion efficiency. Their divergence does not depend directly on the nonlinear order, the intensity or even the nature of the generating gas, but rather on the region of the spectrum the considered harmonic belongs to, which is determined by the combination of the three preceding elements. When the focus is drawn closer to the medium, the distributions get increasingly distorted, becoming annular with a significant divergence for a focus right into-or after-the jet. We perform numerical simulations of the angular distributions. The simulated profiles reproduce remarkably well the experimental trends and are thus used to interpret them. C1 LAWRENCE LIVERMORE NATL LAB,LASER PROGRAM,LIVERMORE,CA 94551. LUND INST TECHNOL,DEPT PHYS,S-22100 LUND,SWEDEN. RP Salieres, P (reprint author), CTR ETUD SACLAY,CEA,DSM,DRECAM,SPAM,F-91191 GIF SUR YVETTE,FRANCE. RI SALIERES, Pascal/L-7776-2014; Lewenstein, Maciej/I-1337-2014; L'Huillier, Anne/P-4379-2015 OI SALIERES, Pascal/0000-0001-5899-8246; Lewenstein, Maciej/0000-0002-0210-7800; L'Huillier, Anne/0000-0002-1335-4022 NR 20 TC 47 Z9 47 U1 0 U2 7 PU IOP PUBLISHING LTD PI BRISTOL PA TECHNO HOUSE, REDCLIFFE WAY, BRISTOL, ENGLAND BS1 6NX SN 0953-4075 J9 J PHYS B-AT MOL OPT JI J. Phys. B-At. Mol. Opt. Phys. PD OCT 28 PY 1996 VL 29 IS 20 BP 4771 EP 4786 DI 10.1088/0953-4075/29/20/027 PG 16 WC Optics; Physics, Atomic, Molecular & Chemical SC Optics; Physics GA VR252 UT WOS:A1996VR25200027 ER PT J AU Lake, B Tennant, DA Cowley, RA Axe, JD Chen, CK AF Lake, B Tennant, DA Cowley, RA Axe, JD Chen, CK TI Magnetic excitations in the ordered phase of the antiferromagnetic alternating chain compound CuWO4 SO JOURNAL OF PHYSICS-CONDENSED MATTER LA English DT Article ID SPIN; CUGEO3 AB In this paper we present the results of a detailed experimental investigation of the magnetic excitations in the spin-1/2 Heisenberg antiferromagnet CuWO4. Inelastic neutron scattering measurements made using a triple-axis spectrometer were performed in the low-temperature ordered phase and also briefly in the high-temperature phase at Brookhaven National Laboratory. The excitations in the ordered phase are compared to a spin-wave model and two possible sets of exchange paths are deduced, both of which provide good fits to the data. In both models CuWO4 consists of weakly coupled alternating one-dimensional chains running in the [2, -1, 0] direction. A calculation of the spin-wave intensities was also performed using the fitted exchange constants and agreement was found with the observed intensities. In the ordered phase, CuWO4 has an energy gap at the zone centre and the excitations are well defined. Above the transition temperature constant-wavevector scans at the antiferromagnetic lattice points suggest the existence of a continuum of excitations. C1 BROOKHAVEN NATL LAB,UPTON,NY 11973. RP Lake, B (reprint author), UNIV OXFORD,CLARENDON LAB,PARKS RD,OXFORD OX1 3PU,ENGLAND. RI Tennant, David/Q-2497-2015; OI Tennant, David/0000-0002-9575-3368; Lake, Bella/0000-0003-0034-0964 NR 23 TC 31 Z9 31 U1 1 U2 10 PU IOP PUBLISHING LTD PI BRISTOL PA TECHNO HOUSE, REDCLIFFE WAY, BRISTOL, ENGLAND BS1 6NX SN 0953-8984 J9 J PHYS-CONDENS MAT JI J. Phys.-Condes. Matter PD OCT 28 PY 1996 VL 8 IS 44 BP 8613 EP 8634 DI 10.1088/0953-8984/8/44/013 PG 22 WC Physics, Condensed Matter SC Physics GA VQ441 UT WOS:A1996VQ44100013 ER PT J AU Bowman, KO Kastenbaum, MA Shenton, LR AF Bowman, KO Kastenbaum, MA Shenton, LR TI Fitting multi-parameter distributions to sister chromatid exchange data SO MUTATION RESEARCH-FUNDAMENTAL AND MOLECULAR MECHANISMS OF MUTAGENESIS LA English DT Article DE distribution; moment estimator; sister chromatid exchange ID PERIPHERAL-BLOOD LYMPHOCYTES; OVERDISPERSION; ASSAY AB Bender et al. (1992) presented the number of sister chromatid exchanges (SCE) in 50 peripheral blood lymphocytes from each of 393 normal human subjects. In that study of 19 650 cells, the number of SCE per cell ranged from 0 to 32. We examine the resulting frequency distributions, and show how they may be fitted, by the method of moments, to discrete Pearson-type and Johnson translation system distributions. C1 UNIV GEORGIA,DEPT STAT,ATHENS,GA 30602. RP Bowman, KO (reprint author), OAK RIDGE NATL LAB,DIV MATH & COMP SCI,MATH SCI SECT,POB 2008,OAK RIDGE,TN 37831, USA. NR 19 TC 2 Z9 2 U1 0 U2 0 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0027-5107 J9 MUTAT RES-FUND MOL M JI Mutat. Res.-Fundam. Mol. Mech. Mutagen. PD OCT 28 PY 1996 VL 358 IS 1 BP 15 EP 24 DI 10.1016/0027-5107(96)00099-1 PG 10 WC Biotechnology & Applied Microbiology; Genetics & Heredity; Toxicology SC Biotechnology & Applied Microbiology; Genetics & Heredity; Toxicology GA VT118 UT WOS:A1996VT11800003 PM 8921973 ER PT J AU Russell, LB Hunsicker, PR Shelby, MD AF Russell, LB Hunsicker, PR Shelby, MD TI Chlorambucil and bleomycin induce mutations in the specific-locus test in female mice SO MUTATION RESEARCH-FUNDAMENTAL AND MOLECULAR MECHANISMS OF MUTAGENESIS LA English DT Article DE oocyte; mutation; germ cell; mouse; specific-locus test; chlorambucil; bleomycin ID MOUSE; RADIATION; OOCYTES; LINE; DNA AB Specific-locus studies have shown chlorambucil (CHL) and bleomycin (BLE) to be mutagenic in mouse oocytes, almost doubling the number of chemicals previously known to induce mutations in females. The overall CHL-induced mutation rate in oocytes is, however, one order of magnitude below that for male meiotic and postmeiotic stages, and only 1/50 that for early spermatids. For BLE, no specific-locus data for males are available for comparison, but the chemical had earlier been found negative for dominant-lethal induction in males. Both BLE and CHL were significantly mutagenic only in mature and maturing oocytes. In keeping with an earlier report, BLE produced a high incidence of dominant lethals in these stages. CHL failed to induce dominant lethals, indicating that for mature and maturing oocytes, in contrast with results for males, sensitivity to dominant-lethal mutations is not a prerequisite for induction of specific-locus mutations. Exposure of immature oocytes to either BLE or CHL produced neither dominant lethals nor significant induction of specific-locus mutations; however, CHL gave evidence of killing immature oocytes. By contrast, BLE, which has been considered a radiomimetic chemical, does not appear to kill immature oocytes and thus differs markedly from radiation exposures equivalent for dominant-lethal induction. Therefore, the failure to recover specific-locus mutations cannot be ascribed to cell selection resulting from oocyte killing, as has sometimes been done for radiation. Adding results on the nature of the CHL- and BLE-induced mutations to prior information, the estimated minimum proportion of large DNA lesions induced in oocytes by chemicals becomes 35.3%, significantly different from the corresponding figure (similar to 70%) for radiations. For chemical treatments, the oocyte proportion is highly significantly above the 3.6% induced in spermatogonia, but only on the borderline of statistically significant difference from that induced in postspermatogonial stages. C1 NIEHS,RES TRIANGLE PK,NC 27709. RP Russell, LB (reprint author), OAK RIDGE NATL LAB,DIV BIOL,POB 2009,OAK RIDGE,TN 37831, USA. FU NIEHS NIH HHS [1-Y01-ES-50318-00] NR 24 TC 7 Z9 9 U1 0 U2 0 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0027-5107 J9 MUTAT RES-FUND MOL M JI Mutat. Res.-Fundam. Mol. Mech. Mutagen. PD OCT 28 PY 1996 VL 358 IS 1 BP 25 EP 35 DI 10.1016/0027-5107(96)00104-2 PG 11 WC Biotechnology & Applied Microbiology; Genetics & Heredity; Toxicology SC Biotechnology & Applied Microbiology; Genetics & Heredity; Toxicology GA VT118 UT WOS:A1996VT11800004 PM 8921974 ER PT J AU Vogt, R Brodsky, SJ AF Vogt, R Brodsky, SJ TI Charmed hadron asymmetries in the intrinsic charm coalescence model SO NUCLEAR PHYSICS B LA English DT Article DE QCD; leading charm; charm hadroproduction; intrinsic charm ID PSI-PSI-PRODUCTION; YAN CROSS-SECTION; PI-P-INTERACTIONS; LUND MONTE-CARLO; MESON PRODUCTION; NUCLEON-INTERACTIONS; JET FRAGMENTATION; POWER CORRECTIONS; DOUBLE QUARKONIUM; E+E-PHYSICS AB Fermilab experiment E791, measuring charmed hadron production in pi(-)A interactions at 500 GeV with high statistics, has observed a strong asymmetry between the hadroproduction cross sections for leading D mesons which contain projectile valence quarks and the non-leading charmed mesons without projectile valence quarks. Such correlations of the charge of the D meson with the quantum numbers of the beam hadron explicitly contradict the factorization theorem in perturbative QCD which predicts that heavy quarks hadronize through a jet fragmentation function that is independent of the initial state, The E791 experiment also measures Lambda(c)/Lambda(c) and D-s/(D) over bar(s) production asymmetries as well as asymmetries in pair production. We examine these asymmetries and the fractional longitudinal momentum, x(F), distributions for single and pairs of charmed hadrons within a two-component model combining leading-twist gg and fusion subprocesses with charm production from intrinsic heavy quark Fock states. A key feature of this analysis is intrinsic charm coalescence, the process by which a charmed quark in the projectile's Fock state wave function forms charmed hadrons by combining with valence quarks of similar rapidities. C1 UNIV CALIF DAVIS, DEPT PHYS, DAVIS, CA 95616 USA. STANFORD UNIV, STANFORD LINEAR ACCELERATOR CTR, STANFORD, CA 94309 USA. RP LAWRENCE BERKELEY LAB, DIV NUCL SCI, BERKELEY, CA 94720 USA. NR 58 TC 70 Z9 70 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 OCT 28 PY 1996 VL 478 IS 1-2 BP 311 EP 332 DI 10.1016/0550-3213(96)00380-X PG 22 WC Physics, Particles & Fields SC Physics GA VQ610 UT WOS:A1996VQ61000015 ER PT J AU Holtmann, E Kawasaki, M Moroi, T AF Holtmann, E Kawasaki, M Moroi, T TI Solving the crisis in big-bang nucleosynthesis by the radiative decay of an exotic particle SO PHYSICAL REVIEW LETTERS LA English DT Article ID COSMOLOGICAL CONSTRAINTS; PRIMORDIAL NUCLEOSYNTHESIS; NEUTRINO DEGENERACY; RELIC PARTICLES; TAU-NEUTRINO; UNIVERSE; SUPERSYMMETRY; GRAVITINO; HE-3; DESTRUCTION AB We discuss a new mechanism which can solve the crisis in standard big-bang nucleosynthesis. A long-lived particle X (10(4) sec less than or similar to tau(x) less than or similar to 10(6) sec) which decays into photon(s) will induce cascade photons, and destroy significant amounts of D and He-3 without destroying He-4 or too much Li-7. We numerically investigate this process and derive a constraint on the properties of X such that the theoretical values of the primordial light-element abundances agree with observation We also present some candidates for the unstable particle X. C1 UNIV CALIF BERKELEY, LAWRENCE BERKELEY LAB, THEORET PHYS GRP, BERKELEY, CA 94720 USA. UNIV TOKYO, INST COSM RAY RES, TOKYO 188, JAPAN. RP UNIV CALIF BERKELEY, DEPT PHYS, BERKELEY, CA 94720 USA. NR 44 TC 13 Z9 13 U1 0 U2 0 PU AMER PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 0031-9007 EI 1079-7114 J9 PHYS REV LETT JI Phys. Rev. Lett. PD OCT 28 PY 1996 VL 77 IS 18 BP 3712 EP 3715 DI 10.1103/PhysRevLett.77.3712 PG 4 WC Physics, Multidisciplinary SC Physics GA VP225 UT WOS:A1996VP22500005 ER PT J AU Anderson, GW Linde, A Riotto, A AF Anderson, GW Linde, A Riotto, A TI Preheating, supersymmetry breaking, and baryogenesis SO PHYSICAL REVIEW LETTERS LA English DT Article ID PARTICLE-PRODUCTION; INFLATIONARY UNIVERSE; ENTROPY CRISIS; SUPERGRAVITY; MECHANISM AB Fluctuations of scalar fields produced at the stage of preheating after inflation are so large that they can break supersymmetry much stronger than inflation itself. These fluctuations may lend to symmetry restoration along Bat directions of the effective potential even in the theories where the usual high temperature corrections are exponentially suppressed. We show that nonthermal phase transitions after preheating may play a crucial role in the generation of the baryon asymmetry by the Affleck-Dine mechanism. In particular, the baryon asymmetry may be generated at the very early state of the evolution of the Universe, at the preheating era, and not when the Hubble parameter becomes of order the gravitino mass. C1 STANFORD UNIV,DEPT PHYS,STANFORD,CA 94305. RP Anderson, GW (reprint author), FERMILAB NATL ACCELERATOR LAB,BATAVIA,IL 60510, USA. OI Anderson, Greg/0000-0003-0346-7258 NR 23 TC 43 Z9 43 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 OCT 28 PY 1996 VL 77 IS 18 BP 3716 EP 3719 DI 10.1103/PhysRevLett.77.3716 PG 4 WC Physics, Multidisciplinary SC Physics GA VP225 UT WOS:A1996VP22500006 ER PT J AU Bender, A Blaschke, D Kalinovsky, Y Roberts, CD AF Bender, A Blaschke, D Kalinovsky, Y Roberts, CD TI Continuum study of deconfinement at finite temperature SO PHYSICAL REVIEW LETTERS LA English DT Article ID CHIRAL-SYMMETRY-BREAKING; CONFINEMENT; PROPAGATOR AB Deconfinement and chiral symmetry restoration are explored in a confining, renormalizable, Dyson-Schwinger equation model of two-flavor QCD. An order parameter for deconfinement is introduced and used to establish that, in the chiral limit, deconfinement and chiral symmetry restoration are coincident at T-c approximate to 150 MeV. The transitions are second order and each has the same critical exponent: beta approximate to 0.3. The deconfinement transition exhibits sensitivity to the current-quark mass. f(pi) and m(pi) change by less than 10% for T < 0.7T(c); however, as T --> T-c, thermal fluctuations cause the pion bound state contribution to the four-point quark-antiquark correlation function to disappear. C1 UNIV ROSTOCK,MAX PLANCK GESELL ARBEITSGRP THEORET VIELTEILCHEN,D-18051 ROSTOCK,GERMANY. JOINT INST NUCL RES,BOGOLIUBOV LAB THEORET PHYS,DUBNA 141980,RUSSIA. RP Bender, A (reprint author), ARGONNE NATL LAB,DIV PHYS,BLDG 203,ARGONNE,IL 60439, USA. OI Roberts, Craig/0000-0002-2937-1361 NR 15 TC 97 Z9 97 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 OCT 28 PY 1996 VL 77 IS 18 BP 3724 EP 3727 DI 10.1103/PhysRevLett.77.3724 PG 4 WC Physics, Multidisciplinary SC Physics GA VP225 UT WOS:A1996VP22500008 ER PT J AU Chang, D Keung, WY AF Chang, D Keung, WY TI Triple pseudoscalar decay mode of the Z boson SO PHYSICAL REVIEW LETTERS LA English DT Article ID SUPERSYMMETRIC STANDARD MODEL; NEUTRAL HIGGS BOSONS; RADIATIVE-CORRECTIONS; SEARCH; MASS; LEP AB We analyze the production of triple pseudoscalar Higgs bosons in the decay channel of Z --> AAA for light pseudoscalar bosons when the corresponding scalar boson is too heavy to be produced by Z decay. Analytic results are obtained both at the tree level and at the one-loop level. The branching fraction can be as large as 10(-5), which should be detectable at the CERN e(+)e(-) collider LEP. C1 UNIV ILLINOIS,DEPT PHYS,CHICAGO,IL 60607. FERMILAB NATL ACCELERATOR LAB,BATAVIA,IL 60510. RP Chang, D (reprint author), NATL TSING HUA UNIV,DEPT PHYS,HSINCHU,TAIWAN. NR 22 TC 7 Z9 7 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 OCT 28 PY 1996 VL 77 IS 18 BP 3732 EP 3735 DI 10.1103/PhysRevLett.77.3732 PG 4 WC Physics, Multidisciplinary SC Physics GA VP225 UT WOS:A1996VP22500010 ER PT J AU Zhang, CT Bhattacharyya, P Daly, PJ Broda, R Grabowski, ZW Nisius, D Ahmad, I Ishii, T Carpenter, MP Morss, LR Phillips, WR Durell, JL Leddy, MJ Smith, AG Urban, W Varley, BJ Schulz, N Lubkiewicz, E Bentaleb, M Blomqvist, J AF Zhang, CT Bhattacharyya, P Daly, PJ Broda, R Grabowski, ZW Nisius, D Ahmad, I Ishii, T Carpenter, MP Morss, LR Phillips, WR Durell, JL Leddy, MJ Smith, AG Urban, W Varley, BJ Schulz, N Lubkiewicz, E Bentaleb, M Blomqvist, J TI Yrast excitations around doubly magic Sn-132 from fission product gamma-ray studies SO PHYSICAL REVIEW LETTERS LA English DT Article AB Prompt gamma-ray cascades in neutron-rich nuclei around doubly magic Sn-132 have been studied at Eurogam II using a Cm-248 fission source. Yrast states to above 5.5 MeV in the two- and three-proton N = 82 isotones Te-134 and I-135 are reported. They are interpreted in terms of valence proton and particle-hole core excitations with the help of shell model calculations employing empirical nucleon-nucleon interactions from both Sn-132 and Pb-208 regions. A serious inconsistency in the accepted masses of N = 82 isotones near Sn-132 is discovered but not resolved. C1 PURDUE UNIV,DEPT PHYS,W LAFAYETTE,IN 47907. ARGONNE NATL LAB,DIV PHYS,ARGONNE,IL 60439. UNIV MANCHESTER,DEPT PHYS & ASTRON,MANCHESTER M13 9PL,LANCS,ENGLAND. UNIV STRASBOURG 1,CTR RECH NUCL,F-67037 STRASBOURG,FRANCE. ROYAL INST TECHNOL,DEPT PHYS FRESCATI,S-10405 STOCKHOLM,SWEDEN. RP Zhang, CT (reprint author), PURDUE UNIV,DEPT CHEM,W LAFAYETTE,IN 47907, USA. RI Carpenter, Michael/E-4287-2015 OI Carpenter, Michael/0000-0002-3237-5734 NR 11 TC 79 Z9 80 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 OCT 28 PY 1996 VL 77 IS 18 BP 3743 EP 3746 DI 10.1103/PhysRevLett.77.3743 PG 4 WC Physics, Multidisciplinary SC Physics GA VP225 UT WOS:A1996VP22500013 ER PT J AU Cao, NZ Chen, SY Sreenivasan, KR AF Cao, NZ Chen, SY Sreenivasan, KR TI Scaling of low-order structure functions in homogeneous turbulence SO PHYSICAL REVIEW LETTERS LA English DT Article ID PROBABILITY DENSITY; VELOCITY INCREMENTS; INTERMITTENCY; DISSIPATION AB High-resolution direct numerical simulation data for three-dimensional Navier-Stokes turbulence in a periodic box are used to study the scaling behavior of low-order velocity structure functions with positive and negative powers. Similar to high-order statistics, the low-order relative scaling exponents exhibit unambiguous departures from the Kolmogorov 1941 theory and agree well with existing multiscaling models. No transition from normal scaling to anomalous scaling is observed. C1 LOS ALAMOS NATL LAB,THEORET DIV,LOS ALAMOS,NM 87545. LOS ALAMOS NATL LAB,CTR NONLINEAR STUDIES,LOS ALAMOS,NM 87545. YALE UNIV,MASON LAB,NEW HAVEN,CT 06520. RP Cao, NZ (reprint author), IBM CORP,THOMAS J WATSON RES CTR,DIV RES,POB 218,YORKTOWN HTS,NY 10598, USA. RI Chen, Shiyi/A-3234-2010 NR 19 TC 18 Z9 18 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 OCT 28 PY 1996 VL 77 IS 18 BP 3799 EP 3802 DI 10.1103/PhysRevLett.77.3799 PG 4 WC Physics, Multidisciplinary SC Physics GA VP225 UT WOS:A1996VP22500027 ER PT J AU Renard, N Labaune, C Baldis, HA Bauer, BS Quesnel, B Schifano, E Michard, A Seka, W Estabrook, KG AF Renard, N Labaune, C Baldis, HA Bauer, BS Quesnel, B Schifano, E Michard, A Seka, W Estabrook, KG TI Detailed characterization of electron plasma waves produced by stimulated Raman scattering SO PHYSICAL REVIEW LETTERS LA English DT Article ID LASER-PRODUCED PLASMAS; RANDOM-PHASE PLATE; PARAMETRIC-INSTABILITIES; BRILLOUIN-SCATTERING; HOT-SPOTS; FOIL TARGETS; EVOLUTION AB Time-resolved spectra and location of electron plasma waves (EPW) produced by stimulated Raman scattering in back and in side directions have been measured using Thomson scattering of a short wavelength probe beam. Significant Raman sidescattering was observed for angles as large as 40 degrees from the laser axis. The Raman growth is larger and starts earlier in the front part of the density profile than at the summit. Simultaneous measurements at multiple places in the plasma provided an indication of the coherence length of the EPW. C1 UNIV ROCHESTER,LASER ENERGET LAB,ROCHESTER,NY 14627. LAWRENCE LIVERMORE NATL LAB,LIVERMORE,CA 94550. RP Renard, N (reprint author), ECOLE POLYTECH,CNRS,LAB UTILISAT LASERS INTENSES,F-91128 PALAISEAU,FRANCE. NR 30 TC 9 Z9 9 U1 0 U2 9 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 0031-9007 J9 PHYS REV LETT JI Phys. Rev. Lett. PD OCT 28 PY 1996 VL 77 IS 18 BP 3807 EP 3810 DI 10.1103/PhysRevLett.77.3807 PG 4 WC Physics, Multidisciplinary SC Physics GA VP225 UT WOS:A1996VP22500029 ER PT J AU Amendt, P Glendinning, SG Hammel, BA Landen, O Suter, LJ AF Amendt, P Glendinning, SG Hammel, BA Landen, O Suter, LJ TI Direct measurement of x-ray drive from surrogate targets in Nova hohlraums SO PHYSICAL REVIEW LETTERS LA English DT Article ID INERTIAL CONFINEMENT FUSION; RADIATION; IGNITION; CAVITIES AB A new method for measuring x-ray drive in Nova hohlraums near target center using surrogate targets is proposed as an alternative to conventional wall-based techniques. A solid, low-density (0.3 g/cm(3)) SiO2 aerogel ball placed at the center of a Nova hohlraum is used to infer x-ray drive from the backlighter-imaged ablatively driven shock trajectory. A nearly 10% (40%) increase in peak radiation temperature (flux) near the hohlraum center in the presence of axial shields is predicted from radiation-hydrodynamics simulations and corroborated by experiment. RP Amendt, P (reprint author), LAWRENCE LIVERMORE NATL LAB,LIVERMORE,CA 94550, USA. NR 27 TC 14 Z9 14 U1 0 U2 6 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 0031-9007 J9 PHYS REV LETT JI Phys. Rev. Lett. PD OCT 28 PY 1996 VL 77 IS 18 BP 3815 EP 3818 DI 10.1103/PhysRevLett.77.3815 PG 4 WC Physics, Multidisciplinary SC Physics GA VP225 UT WOS:A1996VP22500031 ER PT J AU Su, XC Cremer, PS Shen, YR Somorjai, GA AF Su, XC Cremer, PS Shen, YR Somorjai, GA TI Pressure dependence (10(-10)-700 Torr) of the vibrational spectra of adsorbed CO on Pt(111) studied by sum frequency generation SO PHYSICAL REVIEW LETTERS LA English DT Article ID ADSORPTION; SPECTROSCOPY; SURFACE AB The vibrational spectrum of CO on Pt(111) was monitored over 13 orders of magnitude in CO pressure by using infrared-visible sum frequency generation. Surprising results at high pressures indicate a pressure-induced major reorganization of CO on Pt(111). At low pressures (10(-10)-10(-1) Torr) CO bonds at atop and bridge sites, but above 10 Torr new features appear, and by 700 Torr they dominate the spectrum. They suggest the presence of an incommensurate CO overlayer together with some terminally bound CO at atop defect sites. C1 UNIV CALIF BERKELEY,DEPT PHYS,BERKELEY,CA 94720. UNIV CALIF BERKELEY,LAWRENCE BERKELEY LAB,DIV MAT SCI,BERKELEY,CA 94720. RP Su, XC (reprint author), UNIV CALIF BERKELEY,DEPT CHEM,BERKELEY,CA 94720, USA. NR 16 TC 106 Z9 106 U1 3 U2 9 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 0031-9007 J9 PHYS REV LETT JI Phys. Rev. Lett. PD OCT 28 PY 1996 VL 77 IS 18 BP 3858 EP 3860 DI 10.1103/PhysRevLett.77.3858 PG 3 WC Physics, Multidisciplinary SC Physics GA VP225 UT WOS:A1996VP22500042 ER PT J AU Koshelev, AE AF Koshelev, AE TI Plasma resonance and remaining Josephson coupling in the ''decoupled vortex liquid phase'' in layered superconductors SO PHYSICAL REVIEW LETTERS LA English DT Article ID BI2SR2CACU2OX SINGLE-CRYSTALS; HIGH-MAGNETIC-FIELD; STATE; TRANSITION; FLUCTUATIONS; DISSIPATION; SYSTEMS AB We relate the frequency of the Josephson plasma resonance in layered superconductors with the frequency dependent superconducting response. We demonstrate that the sharp resonance can persist even when the global superconducting coherence is broken provided the resonance frequency is larger than the frequency of interlayer phase slips. In this situation the plasma frequency is determined by the average Josephson energy, which can be calculated using the high temperature expansion. We also find the temperature dependence of the average Josephson energy from the Monte Carlo simulations and determine the applicability region of the high temperature expansion. C1 INST SOLID STATE PHYS,CHERNOGOLOVKA 142432,RUSSIA. RP Koshelev, AE (reprint author), ARGONNE NATL LAB,DIV MAT SCI,9700 S CASS AVE,ARGONNE,IL 60439, USA. RI Koshelev, Alexei/K-3971-2013 OI Koshelev, Alexei/0000-0002-1167-5906 NR 26 TC 108 Z9 108 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 OCT 28 PY 1996 VL 77 IS 18 BP 3901 EP 3904 DI 10.1103/PhysRevLett.77.3901 PG 4 WC Physics, Multidisciplinary SC Physics GA VP225 UT WOS:A1996VP22500053 ER PT J AU Hiess, A Bonnet, M Burlet, P Ressouche, E Sanchez, JP Waerenborgh, JC Zwirner, S Wastin, F Rebizant, J Lander, GH Smith, JL AF Hiess, A Bonnet, M Burlet, P Ressouche, E Sanchez, JP Waerenborgh, JC Zwirner, S Wastin, F Rebizant, J Lander, GH Smith, JL TI On the magnetic interactions in metal-Be-13 compounds SO PHYSICAL REVIEW LETTERS LA English DT Article ID NEUTRON-DIFFRACTION; MOSSBAUER; SUPERCONDUCTIVITY; COMMENSURATE; URU2SI2; PHASES; UBE13; UPT3 AB We report magnetization, Mossbauer, and neutron experiments to determine the low-temperature magnetic structure of the heavy-fermion compound NpBe13. The magnetic wave vector is q = [1/3 0 0], and nearest neighbor moments are oriented perpendicular to each other. We have found an unusual modulation of the moments, which reflects the influence of the strong Kondo interaction. Comparisons are made with the magnetic arrangements found in the rare-earth Be-13 compounds, and it is concluded that a search for magnetic correlations in UBe13 should be concentrated around this wave vector. C1 CEA GRENOBLE,DEPT RECH FONDAMENTALE MAT CONDENSEE,F-38054 GRENOBLE 9,FRANCE. LOS ALAMOS NATL LAB,LOS ALAMOS,NM 87545. RP Hiess, A (reprint author), JRC,INST TRANSURANIUM ELEMENTS,EUROPEAN COMMISS,POSTFACH 2340,D-76125 KARLSRUHE,GERMANY. RI Waerenborgh, Joao/C-3701-2011 OI Waerenborgh, Joao/0000-0001-6171-4099 NR 22 TC 12 Z9 12 U1 0 U2 1 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 0031-9007 J9 PHYS REV LETT JI Phys. Rev. Lett. PD OCT 28 PY 1996 VL 77 IS 18 BP 3917 EP 3920 DI 10.1103/PhysRevLett.77.3917 PG 4 WC Physics, Multidisciplinary SC Physics GA VP225 UT WOS:A1996VP22500057 ER PT J AU Glimm, J Saltz, D Sharp, DH AF Glimm, J Saltz, D Sharp, DH TI Renormalization group solution of two-phase flow equations for Rayleigh-Taylor mixing SO PHYSICS LETTERS A LA English DT Article ID GROUP FIXED-POINT; 2-PHASE FLOW; INSTABILITY AB We obtain the exact solution of a recently proposed two-phase flow model of the Rayleigh-Taylor mixing zone, in the incompressible, large time scaling limit. The scaling limit equations are the renormalization group equations for this problem. Our results show that the large time behavior of the incompressible Rayleigh-Taylor mixing layer is determined by a renormalization group fixed point. Our solution allows independent pressures in each fluid. The pressures do not equilibrate dynamically, implying that distinct pressures for each phase is an intrinsic aspect of this problem. C1 LOS ALAMOS NATL LAB,LOS ALAMOS,NM 87545. RP Glimm, J (reprint author), SUNY STONY BROOK,STONY BROOK,NY 11794, USA. NR 15 TC 15 Z9 15 U1 0 U2 2 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 OCT 28 PY 1996 VL 222 IS 3 BP 171 EP 176 DI 10.1016/0375-9601(96)00648-2 PG 6 WC Physics, Multidisciplinary SC Physics GA VN249 UT WOS:A1996VN24900009 ER PT J AU Goldman, T Hochberg, D Laflamme, R PerezMercader, J AF Goldman, T Hochberg, D Laflamme, R PerezMercader, J TI The galaxy-galaxy correlation function as an indicator of critical phenomena in cosmology SO PHYSICS LETTERS A LA English DT Article AB We approximate the observable Universe by a collection of equal mass galaxies linked into a many body system by their mutual gravitational interaction, Under the assumptions of (i) nonrelativistic approximation and (ii) global quasi-equilibrium, the partition function of this system can be cast in terms of Ising model spin variables and maps exactly onto a three-dimensional scalar classical field theory, The full machinery of the renormalization group and critical phenomena is brought to bear on this field theory allowing one to calculate the galaxy to-galaxy correlation function, whose critical exponent is predicted to be between 1.530 to 1.862, to be compared to the phenomenological/observational value of 1.6 to 1.8. C1 LAB ASTROFIS ESPACIAL & FIS FUNDAMENTAL,MADRID 28080,SPAIN. RP Goldman, T (reprint author), LOS ALAMOS NATL LAB,DIV THEORET,LOS ALAMOS,NM 87545, USA. NR 11 TC 9 Z9 10 U1 0 U2 5 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 OCT 28 PY 1996 VL 222 IS 3 BP 177 EP 181 DI 10.1016/0375-9601(96)00588-9 PG 5 WC Physics, Multidisciplinary SC Physics GA VN249 UT WOS:A1996VN24900010 ER PT J AU Melnick, RL Sills, RC Roycroft, JH Chou, BJ Ragan, HA Miller, RA AF Melnick, RL Sills, RC Roycroft, JH Chou, BJ Ragan, HA Miller, RA TI Inhalation toxicity and carcinogenicity of isoprene in rats and mice: Comparisons with 1,3-butadiene SO TOXICOLOGY LA English DT Article; Proceedings Paper CT International Symposium on Evaluation of Butadiene and Isoprene Health Risks CY JUN 27-29, 1995 CL BLAINE, WA SP Amer Ind Hygiene Assoc, Amer Petr Inst, Chem Ind Inst Toxicol, Chem Manufacturers Assoc, EPA, European Chem Ind Council, European Ctr Ecotoxicol & Toxicol Chem, Hlth Effects Inst, Int Agcy Res Canc, Int Inst Synthet Rubber Producers, Int Programme Chem Safety, NIEHS, Soc Toxicol, Univ Washington, Sch Public Hlth & Community Med, Int Congress Toxicol DE Isoprene; Lung neoplasia; Liver neoplasia; Forestomach neoplasia; Macrocytic anemia ID B6C3F1 MICE; METABOLISM; EXPOSURE; MUTAGENICITY; HYDROCARBON AB As with 1,3-butadiene(BD), inhalation exposure of B6C3F(1) mice to isoprene (2-methyl-1,3-butadiene) caused a macrocytic anemia; induced increases in sister chromatid exchanges in bone marrow cells and in levels of micronucleated erythrocytes in peripheral blood; and produced degeneration of the olfactory epithelium, forestomach epithelial hyperplasia, and testicular atrophy. Most notable was the finding that like BD, isoprene induced neoplasms in the liver, lung, Harderian gland, and forestomach of mice. The carcinogenic effects of isoprene were observed after a 26-week exposure (6 h/day, 5 days/week) of male mice to 700 ppm or higher concentrations of isoprene followed by a 26-week recovery period. Unlike BD, isoprene did not induce lymphomas or hemangiosarcomas of the heart in mice under these conditions nor did it induce chromosomal aberrations in mouse bone marrow cells. No toxicological effects were evident in rats exposed for 13 weeks to either isoprene or BD at concentrations up to 7000 ppm or 8000 ppm, respectively. Interstitial cell hyperplasia of the testis was observed in male F344 rats exposed to 7000 ppm isoprene for 26 weeks, and following a 26-week recovery period, there was a marginal increase in benign testicular interstitial cell tumors C1 PACIFIC NW LAB, RICHLAND, WA 99352 USA. RP Melnick, RL (reprint author), NIEHS, LAB QUANTITAT & COMPUTAT BIOL, POB 12233, RES TRIANGLE PK, NC 27709 USA. NR 20 TC 8 Z9 8 U1 0 U2 1 PU ELSEVIER SCI IRELAND LTD PI CLARE PA CUSTOMER RELATIONS MANAGER, BAY 15, SHANNON INDUSTRIAL ESTATE CO, CLARE, IRELAND SN 0300-483X J9 TOXICOLOGY JI Toxicology PD OCT 28 PY 1996 VL 113 IS 1-3 BP 247 EP 252 DI 10.1016/0300-483X(96)03453-1 PG 6 WC Pharmacology & Pharmacy; Toxicology SC Pharmacology & Pharmacy; Toxicology GA VQ391 UT WOS:A1996VQ39100036 PM 8901905 ER PT J AU Suszcynsky, DM RousselDupre, R Shaw, G AF Suszcynsky, DM RousselDupre, R Shaw, G TI Ground-based search for X rays generated by thunderstorms and lightning SO JOURNAL OF GEOPHYSICAL RESEARCH-ATMOSPHERES LA English DT Article ID RUNAWAY AIR-BREAKDOWN AB A series of ground-based experiments have been performed to investigate gamma ray/X ray count rate increases that are associated with thunderstorm and lightning activity. NaI scintillation detectors were configured in a long-timescale channel to monitor long-term count rate variations (on timescales of 1-10(4) s) as a function of time, pressure, temperature, humidity, electric field, rainfall, and general thunderstorm activity and in a short-timescale channel that was triggered by an electric field change meter to monitor correlations of individual counts (on timescales of 10(-7)-10(-2) s) with particular phases of a lightning flash. Long-timescale results typically show count rate increases of a few percent to as much as 100% above background levels during thunderstorm activity and are likely due primarily to gamma ray emissions from radon daughter-ion decay as the daughter ions are precipitated to the ground by rainfall. The production of bremsstrahlung X rays by a thunderstorm runaway electron mechanism cannot be ruled out by this data, but the data indicate that if the mechanism is in operation, the bremsstrahlung flux at the ground is at best intermittent and/or barely discernible above background levels. Short-timescale results do not show any evidence for the production of X rays by individual lightning flashes. However, these results are inconclusive since only 10 cases of lightning flashes within a 1 km distance were recorded. The results of the overall study are compared to previous studies which claim positive correlations of count rate increases with thunderstorm and lightning activity. They are also discussed in terms of runaway electron acceleration in thunderstorm electric fields and in terms of the runaway air breakdown mechanism for lightning initiation. A review of the physics of and previous studies of X ray emissions from thunderstorms and lightning is presented in the introduction. C1 UNIV ALASKA, INST GEOPHYS, FAIRBANKS, AK 99701 USA. RP Suszcynsky, DM (reprint author), LOS ALAMOS NATL LAB, SPACE & ATMOSPHER SCI GRP, MS D466, LOS ALAMOS, NM 87545 USA. NR 55 TC 45 Z9 48 U1 1 U2 2 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 2169-897X J9 J GEOPHYS RES-ATMOS JI J. Geophys. Res.-Atmos. PD OCT 27 PY 1996 VL 101 IS D18 BP 23505 EP 23516 DI 10.1029/96JD02134 PG 12 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA VP976 UT WOS:A1996VP97600020 ER PT J AU Rosenberg, AH Griffin, M Washington, MT Patel, SS Studier, FW AF Rosenberg, AH Griffin, M Washington, MT Patel, SS Studier, FW TI Selection, identification, and genetic analysis of random mutants in the cloned primase/helicase gene of bacteriophage T7 SO JOURNAL OF BIOLOGICAL CHEMISTRY LA English DT Article ID HELICASE-PRIMASE; RNA-POLYMERASE; DNA; PROTEINS; RECOMBINATION; EXPRESSION; FRAGMENTS; SEQUENCE; REGION AB T7 gene 4 specifies two overlapping proteins 4A, a 566-amino acid primase/helicase, and 4B, a 503-amino acid helicase whose initiation codon is the 64th codon of the 4A protein, The 4A' gene, which has a leucine codon replacing the 4B initiation codon, specifies a single 566-amino acid protein that can provide the primase and helicase functions required for normal T7 growth, We selected N-methyl-N'-nitro-N-nitrosoguanidine mutants in the cloned 4A' gene that no longer support the growth of a phage that completely lacks gene 4, Genetic mapping of the 76 mutations found them to be distributed throughout the protein, including both the N-terminal and C-terminal halves of the molecule thought to represent primase and helicase domains, respectively, Complementation tests with partially and completely defective phage showed that all but five of the mutants lacked helicase function but retained primase function, The other five, which lacked both functions, all made short proteins, including one missing only 60 amino acids. No mutations lacked only primase function, and none mapped within the first 105 amino acids, which includes the 63-amino acid region unique to 4A that contains elements required to recognize primase sites, Forty-six mutations were sequenced and included 27 missense mutations affecting 25 amino acids, Many mutations in the N-terminal half of the protein affected its solubility in cell extracts. Mutations in the C-terminal half clustered in or near five helicase consensus sequences, Biochemical analysis of nine of the mutant proteins is described in the accompanying paper (Washington, M. T., Rosenberg, A. H., Griffin, K., Studier, F. W., and Patel, S. S. (1996) J. Biol. Chem. 271, 26825-26834). C1 OHIO STATE UNIV,DEPT BIOCHEM,COLUMBUS,OH 43210. RP Rosenberg, AH (reprint author), BROOKHAVEN NATL LAB,DEPT BIOL,UPTON,NY 11973, USA. NR 26 TC 17 Z9 17 U1 1 U2 1 PU AMER SOC BIOCHEMISTRY MOLECULAR BIOLOGY INC PI BETHESDA PA 9650 ROCKVILLE PIKE, BETHESDA, MD 20814 SN 0021-9258 J9 J BIOL CHEM JI J. Biol. Chem. PD OCT 25 PY 1996 VL 271 IS 43 BP 26819 EP 26824 PG 6 WC Biochemistry & Molecular Biology SC Biochemistry & Molecular Biology GA VP233 UT WOS:A1996VP23300057 PM 8900163 ER PT J AU Washington, MT Rosenberg, AH Griffin, K Studier, FW Patel, SS AF Washington, MT Rosenberg, AH Griffin, K Studier, FW Patel, SS TI Biochemical analysis of mutant T7 primase/helicase proteins defective in DNA binding, nucleotide hydrolysis, and the coupling of hydrolysis with DNA unwinding SO JOURNAL OF BIOLOGICAL CHEMISTRY LA English DT Article ID SECONDARY STRUCTURE PREDICTION; SINGLE-STRANDED-DNA; COLI RECA PROTEIN; BACTERIOPHAGE-T7 DEOXYRIBONUCLEIC-ACID; PRIMASE-HELICASE PROTEIN; GENE-4 PROTEIN; RNA-POLYMERASE; CLONED GENES; REPLICATION; SEQUENCE AB We characterized nine helicase-deficient mutants of bacteriophage T7 helicase-primase protein (4A') prepared by random mutagenesis as reported in the accompanying paper (Rosenberg, A, H., Griffin, K., Washington, A. T., Patel, S. S., and Studier, F. W. (1996) J. Biol. Chem. 271, 26819-26824). Mutants were selected from each of the helicase-conserved motifs for detailed analysis to understand better their function. In agreement with the in vivo results, the mutants were defective in helicase activity but were active in primase function, dTTP hydrolysis, DNA binding, and hexamer formation were examined, Three classes of defective mutants were observed, Group A mutants (E348K, D424N, and S496F), defective in dTTP hydrolysis, lie in motifs 1a, 2, and 4 and are possibly involved in NTP binding/hydrolysis, Group B mutants (R487C and G488D), defective in DNA binding, lie in motif 4 and are responsible directly or indirectly for DNA binding, Group C mutants (G116D, A257T, S345F, and G451E) were not defective in any of the activities except the helicase function, These mutants, scattered throughout the protein, appear defective in coupling dTTPase activity to helicase function, Secondary structural predictions of 4A' and DnaB helicases resemble the known structures of RecA and F-1-ATPase enzymes, Alignment shows a striking correlation in the positions of the amino acids that interact with NTP and DNA. C1 OHIO STATE UNIV,DEPT BIOCHEM,COLUMBUS,OH 43210. BROOKHAVEN NATL LAB,DEPT BIOL,UPTON,NY 11973. NR 42 TC 80 Z9 80 U1 0 U2 0 PU AMER SOC BIOCHEMISTRY MOLECULAR BIOLOGY INC PI BETHESDA PA 9650 ROCKVILLE PIKE, BETHESDA, MD 20814 SN 0021-9258 J9 J BIOL CHEM JI J. Biol. Chem. PD OCT 25 PY 1996 VL 271 IS 43 BP 26825 EP 26834 PG 10 WC Biochemistry & Molecular Biology SC Biochemistry & Molecular Biology GA VP233 UT WOS:A1996VP23300058 PM 8900164 ER PT J AU Herrmannsfeldt, WB AF Herrmannsfeldt, WB TI Tritium production SO SCIENCE LA English DT Letter RP Herrmannsfeldt, WB (reprint author), STANFORD LINEAR ACCELERATOR CTR,EXTERNAL REVIEW COMM APT,STANFORD,CA 94309, USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU AMER ASSOC ADVANCEMENT SCIENCE PI WASHINGTON PA 1200 NEW YORK AVE, NW, WASHINGTON, DC 20005 SN 0036-8075 J9 SCIENCE JI Science PD OCT 25 PY 1996 VL 274 IS 5287 BP 481 EP 481 PG 1 WC Multidisciplinary Sciences SC Science & Technology - Other Topics GA VN919 UT WOS:A1996VN91900002 ER PT J AU Browne, JC AF Browne, JC TI Tritium production SO SCIENCE LA English DT Letter C1 LOS ALAMOS NATL LAB,ENERGY RES PROGRAMS,LOS ALAMOS,NM 87545. RP Browne, JC (reprint author), LOS ALAMOS NATL LAB,LOS ALAMOS NEUTRON SCI CTR,LOS ALAMOS,NM 87545, USA. NR 1 TC 0 Z9 0 U1 0 U2 0 PU AMER ASSOC ADVANCEMENT SCIENCE PI WASHINGTON PA 1200 NEW YORK AVE, NW, WASHINGTON, DC 20005 SN 0036-8075 J9 SCIENCE JI Science PD OCT 25 PY 1996 VL 274 IS 5287 BP 482 EP 482 PG 1 WC Multidisciplinary Sciences SC Science & Technology - Other Topics GA VN919 UT WOS:A1996VN91900004 ER PT J AU Fisher, DR Dobbin, KD Waltar, AR Lindenmeier, CW AF Fisher, DR Dobbin, KD Waltar, AR Lindenmeier, CW TI Tritium production SO SCIENCE LA English DT Letter C1 FLUOR DANIEL NW,SAFETY ANAL & NUCL ENGN DEPT,RICHLAND,WA 99352. AMER NUCL SOC,RICHLAND,WA 99352. ADV NUCL & MED SYST,RICHLAND,WA 99352. RP Fisher, DR (reprint author), PACIFIC NW NATL LAB,HANFORD ISOTOPES PROGRAM,RICHLAND,WA 99352, USA. NR 3 TC 0 Z9 0 U1 0 U2 2 PU AMER ASSOC ADVANCEMENT SCIENCE PI WASHINGTON PA 1200 NEW YORK AVE, NW, WASHINGTON, DC 20005 SN 0036-8075 J9 SCIENCE JI Science PD OCT 25 PY 1996 VL 274 IS 5287 BP 482 EP 483 PG 2 WC Multidisciplinary Sciences SC Science & Technology - Other Topics GA VN919 UT WOS:A1996VN91900005 ER PT J AU Debreczeny, MP Svec, WA Wasielewski, MR AF Debreczeny, MP Svec, WA Wasielewski, MR TI Optical control of photogenerated ion pair lifetimes: An approach to a molecular switch SO SCIENCE LA English DT Article ID ELECTRON-TRANSFER; DEVICES; PHOTOSYNTHESIS; AMPLIFICATION; ACCEPTOR; SYSTEMS; SHIFT AB A prototype molecular switch is demonstrated that works on the principle that the local electric field produced by one photogenerated ion pair (D-1(+)-A(1)(-)) can influence the rate constants for photoinduced electron transfer and recombination in a second donor-acceptor pair (A(2)-D-2). Two ultrafast laser pulses were used to control the rate of a photoinduced electron transfer reaction within a molecule that consists of two covalently linked electron donor-acceptor pairs fixed in a linear structure, D-1-A(1)-A(2)-D-2. This type of molecular architecture may lead to the development of electronic devices that function on the molecular length scale. C1 ARGONNE NATL LAB,DIV CHEM,ARGONNE,IL 60439. NORTHWESTERN UNIV,DEPT CHEM,EVANSTON,IL 60208. NR 28 TC 157 Z9 162 U1 1 U2 16 PU AMER ASSOC ADVANCEMENT SCIENCE PI WASHINGTON PA 1200 NEW YORK AVE, NW, WASHINGTON, DC 20005 SN 0036-8075 J9 SCIENCE JI Science PD OCT 25 PY 1996 VL 274 IS 5287 BP 584 EP 587 DI 10.1126/science.274.5287.584 PG 4 WC Multidisciplinary Sciences SC Science & Technology - Other Topics GA VN919 UT WOS:A1996VN91900042 ER PT J AU Schenter, GK Glendening, ED AF Schenter, GK Glendening, ED TI Natural energy decomposition analysis: The linear response electrical self energy SO JOURNAL OF PHYSICAL CHEMISTRY LA English DT Article ID MOLECULAR-INTERACTIONS; BASIS-SETS; AB-INITIO; HYDROGEN; BOND AB An extension of the natural energy decomposition analysis (NEDA) is described that leads to a reduced, three-component treatment of ab initio molecular interaction potentials. These components include the classical electrical (static and induced) and quantum mechanical core (sigma-sigma) and charge transfer (sigma-sigma*) interactions. The electrical component is, in turn, represented by three terms: the static interaction of unperturbed fragment charge densities, a contribution involving polarized charge densities, and an electrical self polarization energy. Extended basis set calculations demonstrate the high numerical stability of the three-component NEDA approach. Applications are presented for the Li+(H2O) and water dimer complexes. The long-range behavior of the interaction potentials of these complexes is entirely determined by the classical electrical interaction of the fragments. Core and charge transfer effects are only significant for molecular separations within roughly 1 Angstrom of equilibrium. C1 INDIANA STATE UNIV, DEPT CHEM, TERRE HAUTE, IN 47809 USA. RP Schenter, GK (reprint author), PACIFIC NW LAB, ENVIRONM MOL SCI LAB, RICHLAND, WA 99352 USA. RI Schenter, Gregory/I-7655-2014 OI Schenter, Gregory/0000-0001-5444-5484 NR 25 TC 88 Z9 88 U1 0 U2 5 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 0022-3654 J9 J PHYS CHEM-US JI J. Phys. Chem. PD OCT 24 PY 1996 VL 100 IS 43 BP 17152 EP 17156 DI 10.1021/jp9612994 PG 5 WC Chemistry, Physical SC Chemistry GA VP261 UT WOS:A1996VP26100012 ER PT J AU Wang, Q Kochendoerfer, GG Schoenlein, RW Verdegem, PJE Lugtenburg, J Mathies, RA Shank, CV AF Wang, Q Kochendoerfer, GG Schoenlein, RW Verdegem, PJE Lugtenburg, J Mathies, RA Shank, CV TI Femtosecond spectroscopy of a 13-demethylrhodopsin visual pigment analogue: The role of nonbonded interactions in the isomerization process SO JOURNAL OF PHYSICAL CHEMISTRY LA English DT Article ID CIS-TRANS ISOMERIZATION; 1ST STEP; CHROMOPHORE STRUCTURE; PRIMARY PHOTOPRODUCT; ENERGY-STORAGE; RHODOPSIN; BACTERIORHODOPSIN; VISION; ISORHODOPSIN; BATHORHODOPSIN AB The photoisomerization reaction of the visual pigment analogue 11-cis-13-demethylrhodopsin is investigated using femtosecond pump-probe techniques. Following excitation with a 40-fs pump pulse at 500 nm, differential transient absorption spectra are measured from 470 to 560 nm using a 10-fs probe pulse centered at 500 nm and from 560 to 650 nm using a 10-fs probe pulse centered at 620 nm. The persistence of the excited-state absorption, the recovery kinetics of the ground-state bleach, and the formation time of the photoproduct absorption all indicate that this photoisomerization reaction is complete on the 400-fs time scale. Comparison of the reaction dynamics of 11-cis-rhodopsin with 11-cis-13-demethylrhodopsin suggests that the removal of the nonbonded steric interaction between the C-13-methyl group and the C-10-hydrogen atom slows down the initial torsional dynamics and that this in turn results in a lower isomerization quantum yield and a slower overall reaction time. Our results support the hypothesis that the quantum yield and the speed of the isomerization reaction are coupled according to a dynamic potential-surface crossing mechanism. C1 LAWRENCE BERKELEY LAB,DIV SCI MAT,BERKELEY,CA 94720. UNIV CALIF BERKELEY,DEPT CHEM,BERKELEY,CA 94720. LEIDEN UNIV,LEIDEN INST CHEM,NL-2300 RA LEIDEN,NETHERLANDS. RI Schoenlein, Robert/D-1301-2014 OI Schoenlein, Robert/0000-0002-6066-7566 NR 27 TC 59 Z9 60 U1 2 U2 6 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 SN 0022-3654 J9 J PHYS CHEM-US JI J. Phys. Chem. PD OCT 24 PY 1996 VL 100 IS 43 BP 17388 EP 17394 DI 10.1021/jp961150s PG 7 WC Chemistry, Physical SC Chemistry GA VP261 UT WOS:A1996VP26100045 ER PT J AU Wu, M Goodwin, PM Ambrose, WP Keller, RA AF Wu, M Goodwin, PM Ambrose, WP Keller, RA TI Photochemistry and fluorescence emission dynamics of single molecules in solution: B-phycoerythrin SO JOURNAL OF PHYSICAL CHEMISTRY LA English DT Article ID LASER-INDUCED FLUORESCENCE; LEVITATED MICRODROPLETS; RESONANCE FLUORESCENCE; SPECTRAL DIFFUSION; IMPURITY MOLECULES; ENERGY-TRANSFER; SPECTROSCOPY; EXCITATION; CRYSTAL; RHODAMINE-6G AB We report the first detailed studies of the photochemistry of single molecules in aqueous solution. Photolysis of single B-phycoerythrin (B-PE) molecules, a highly fluorescent phycobiliprotein containing 34 bilin chromophores, is observed as an abrupt cessation of the fluorescence emission from individual molecules as they flow through a similar to 40 pL probe volume. These measurements demonstrate that B-PE is photolyzed in a single photochemical step. The observation of abrupt photobleaching of single molecules could not be made in a bulk measurement because the signal would be averaged over many molecules to yield a continuous decay. Photon pair correlation measurements of the fluorescence detected from single B-PE molecules demonstrate that the molecule behaves as a single quantum system, not as a collection of 34 independent chromophores. C1 LOS ALAMOS NATL LAB,CHEM SCI & TECHNOL DIV,LOS ALAMOS,NM 87545. NR 45 TC 67 Z9 67 U1 1 U2 14 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 SN 0022-3654 J9 J PHYS CHEM-US JI J. Phys. Chem. PD OCT 24 PY 1996 VL 100 IS 43 BP 17406 EP 17409 DI 10.1021/jp9616775 PG 4 WC Chemistry, Physical SC Chemistry GA VP261 UT WOS:A1996VP26100048 ER PT J AU Wu, CL Guidry, M Feng, DH AF Wu, CL Guidry, M Feng, DH TI Z=110-111 elements and the stability of heavy and superheavy elements SO PHYSICS LETTERS B LA English DT Article ID FERMION DYNAMICAL SYMMETRY; NUCLEAR-MASSES; MODEL; IDENTIFICATION AB The recent discovery of isotopes with Z = 110-111 is consistent with (1) a monopole-monopole interaction that does not appear explicitly in Nilsson-Strutinsky mass systematics, and (2) a competition between SU(2) and SU(3) dynamical symmetries that has been predicted for this region. Our calculations suggest that these new isotopes are near spherical, and may represent a true island of superheavy nuclei, but shifted downward in neutron number by these new physical effects. C1 UNIV TENNESSEE,DEPT PHYS & ASTRON,KNOXVILLE,TN 37996. OAK RIDGE NATL LAB,DIV PHYS,OAK RIDGE,TN 37831. DREXEL UNIV,DEPT PHYS & ATMOSPHER SCI,PHILADELPHIA,PA 19104. RP Wu, CL (reprint author), CHUNG YUAN CHRISTIAN UNIV,DEPT PHYS,CHUNGLI 32023,TAIWAN. NR 21 TC 15 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 OCT 24 PY 1996 VL 387 IS 3 BP 449 EP 454 DI 10.1016/0370-2693(96)01072-6 PG 6 WC Astronomy & Astrophysics; Physics, Nuclear; Physics, Particles & Fields SC Astronomy & Astrophysics; Physics GA VN531 UT WOS:A1996VN53100002 ER PT J AU Gaillard, MK Jain, V Saririan, K AF Gaillard, MK Jain, V Saririan, K TI Supergravity coupled to chiral and Yang-Mills matter at one loop SO PHYSICS LETTERS B LA English DT Article ID PAULI-VILLARS REGULARIZATION; STRING EFFECTIVE THEORIES; = 1 SUPERGRAVITY; RADIATIVE-CORRECTIONS; ANOMALY CANCELLATION; LINEAR MULTIPLET; GAUGE COUPLINGS; FIELD-THEORIES; RENORMALIZATION; SUPERSYMMETRY AB We present the full result for the divergent one-loop contribution to the effective boson Lagrangian for supergravity coupled to chiral and Yang-Mills supermultiplets, We also consider the specific case of dilaton couplings in effective supergravity Lagrangians from superstrings, for which the one-loop result is considerably simplified. C1 UNIV CALIF BERKELEY,LAWRENCE BERKELEY LAB,THEORET PHYS GRP,BERKELEY,CA 94720. SUNY STONY BROOK,INST THEORET PHYS,STONY BROOK,NY 11794. RP Gaillard, MK (reprint author), UNIV CALIF BERKELEY,LAWRENCE BERKELEY LAB,DEPT PHYS,BERKELEY,CA 94720, USA. NR 32 TC 24 Z9 24 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 OCT 24 PY 1996 VL 387 IS 3 BP 520 EP 528 DI 10.1016/0370-2693(96)01084-2 PG 9 WC Astronomy & Astrophysics; Physics, Nuclear; Physics, Particles & Fields SC Astronomy & Astrophysics; Physics GA VN531 UT WOS:A1996VN53100013 ER PT J AU ArkaniHamed, N Cheng, HC Moroi, T AF ArkaniHamed, N Cheng, HC Moroi, T TI Non-unified gaugino masses in supersymmetric missing partner models with hypercolor SO PHYSICS LETTERS B LA English DT Article ID SOFTLY BROKEN SUPERSYMMETRY; 2-LOOP RENORMALIZATION; GRAND UNIFICATION; HIGGS DOUBLETS; BREAKING; SU(5); SO(10); ELECTROWEAK; HIERARCHY; COUPLINGS AB The gaugino mass relations m(3)/g(3)(2) = m(2)/g(2)(2) = m(1)/g(1)(2) are considered to be robust signals for supersymmetric grand unification. In this letter, we point out that these relations may be significantly modified in an interesting class of models which solve the doublet-triplet splitting problem using a missing partner mechanism together with a strong hypercolor gauge group. The observation of non-unified gaugino masses, together with unified sfermion masses, provides a distinctive signature for these models. C1 UNIV CALIF BERKELEY,DEPT PHYS,BERKELEY,CA 94720. RP ArkaniHamed, N (reprint author), UNIV CALIF BERKELEY,LAWRENCE BERKELEY LAB,THEORET PHYS GRP,BERKELEY,CA 94720, USA. NR 33 TC 24 Z9 24 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 OCT 24 PY 1996 VL 387 IS 3 BP 529 EP 534 DI 10.1016/0370-2693(96)01089-1 PG 6 WC Astronomy & Astrophysics; Physics, Nuclear; Physics, Particles & Fields SC Astronomy & Astrophysics; Physics GA VN531 UT WOS:A1996VN53100014 ER PT J AU Dobado, A Morales, J Pelaez, JR Urdiales, MT AF Dobado, A Morales, J Pelaez, JR Urdiales, MT TI Higgs physics in the large N limit SO PHYSICS LETTERS B LA English DT Article ID STRONGLY INTERACTING WS; SYMMETRY-BREAKING; STANDARD MODEL; WW SCATTERING; UNITARITY; SCALAR; RESONANCES; MATRIX; BOSONS; SECTOR AB In this paper we study the large N limit of the Standard Model Higgs sector with N lambda, Ng(2) and Ng('2) constant and N being the number of would-be Goldstone bosons, Despite the simplicity of this method at leading order, its results satisfy simultaneously important requirements such as unitarity and the low-energy theorems in contrast with other more conventional approaches. Moreover, it is fully compatible with the Equivalence Theorem and it yields a consistent description of the Higgs boson mass and width, Finally we have also included a phenomenological discussion concerning the applications of this method to the LHC. C1 UNIV CALIF BERKELEY,LAWRENCE BERKELEY LAB,THEORET PHYS GRP,BERKELEY,CA 94720. UNIV AUTONOMA MADRID,DEPT FIS TEOR,MADRID 28049,SPAIN. UNIV NACL COLOMBIA,DEPT FIS,BOGOTA 5997,COLOMBIA. RP Dobado, A (reprint author), UNIV COMPLUTENSE MADRID,DEPT FIS TEOR,MADRID 28040,SPAIN. RI Pelaez, Jose/K-9767-2014 OI Pelaez, Jose/0000-0003-0737-4681 NR 32 TC 5 Z9 5 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 OCT 24 PY 1996 VL 387 IS 3 BP 563 EP 572 DI 10.1016/0370-2693(96)01052-0 PG 10 WC Astronomy & Astrophysics; Physics, Nuclear; Physics, Particles & Fields SC Astronomy & Astrophysics; Physics GA VN531 UT WOS:A1996VN53100019 ER PT J AU Gordon, LE Vogelsang, W AF Gordon, LE Vogelsang, W TI Inclusive prompt photon production in polarized pp collisions at HERA-(N)over-right-arrow SO PHYSICS LETTERS B LA English DT Article ID TO-LEADING-ORDER; GLUON POLARIZATION; QCD JETS; PROTON; TARGET; PREDICTIONS; COLLIDERS; BEAM AB We present a NLO study of inclusive polarized prompt photon production in a conceivable fixed target pp mode of HERA with longitudinally polarized protons at root s = 39 GeV. We analyze the sensitivity of the corresponding double spin asymmetry to the proton's polarized gluon distribution Delta g and estimate the expected statistical precision in its determination. The main theoretical uncertainties in the predictions are examined. C1 RUTHERFORD APPLETON LAB,DIDCOT OX11 0QX,OXON,ENGLAND. RP Gordon, LE (reprint author), ARGONNE NATL LAB,DIV HIGH ENERGY PHYS,ARGONNE,IL 60439, USA. NR 43 TC 10 Z9 10 U1 0 U2 0 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0370-2693 J9 PHYS LETT B JI Phys. Lett. B PD OCT 24 PY 1996 VL 387 IS 3 BP 629 EP 636 DI 10.1016/0370-2693(96)01062-3 PG 8 WC Astronomy & Astrophysics; Physics, Nuclear; Physics, Particles & Fields SC Astronomy & Astrophysics; Physics GA VN531 UT WOS:A1996VN53100028 ER PT J AU Schoonover, JR Zietlow, TC Clark, DL Heppert, JA Chisholm, MH Gray, HB Sattelberger, AP Woodruff, WH AF Schoonover, JR Zietlow, TC Clark, DL Heppert, JA Chisholm, MH Gray, HB Sattelberger, AP Woodruff, WH TI Resonance Raman spectra of [M(6)X(8)Y(6)](2-) cluster complexes (M=Mo,W; X,Y=Cl,Br,I) SO INORGANIC CHEMISTRY LA English DT Article ID HALIDE CLUSTERS; CHEVREL PHASES; MOLYBDENUM; UNIT; HYDRODESULFURIZATION; DERIVATIVES; ALKOXIDES; ANION AB Resonance Raman spectra of the cubic metal-halide complexes having the general formula [M(6)X(8)Y(6)](2-) (M = Mo or W; X, Y = Cl, Br, at I) are reported. The three totally symmetric fundamental vibrations of these complexes are identified. The extensive mixing of the symmetry coordinates that compose the symmetric normal modes expected in these systems is not observed. Instead the ''group-frequency'' approximation is valid. Furthermore, the force constants of both the apical and face-bridging metal-halide bonds are insensitive to the identity of either the metal or the halide. Raman spectra of related complexes with methoxy and benzenethiol groups as ligands are reported along with the structural data for [Mo6Cl8(SPh)(6)][NBu(4)](2). Crystal data for [Mo6Cl8(SPh)(6)][NBu(4)](2) at -156 degrees C: monoclinic space group P2(1)/c; a = 12.588(3), b = 17.471(5), c = 20.646(2) Angstrom; beta = 118.53(1)degrees, V = 3223.4 Angstrom(3); d(calcd) = 1.664 g cm(-3); Z = 2. RP Schoonover, JR (reprint author), LOS ALAMOS NATL LAB,CHEM SCI & TECHNOL LAB,LOS ALAMOS,NM 87545, USA. RI Clark, David/A-9729-2011 NR 47 TC 30 Z9 30 U1 0 U2 6 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 SN 0020-1669 J9 INORG CHEM JI Inorg. Chem. PD OCT 23 PY 1996 VL 35 IS 22 BP 6606 EP 6613 DI 10.1021/ic960184b PG 8 WC Chemistry, Inorganic & Nuclear SC Chemistry GA VP449 UT WOS:A1996VP44900035 ER PT J AU Hasharoni, K Levanon, H Greenfield, SR Gosztola, DJ Svec, WA Wasielewski, MR AF Hasharoni, K Levanon, H Greenfield, SR Gosztola, DJ Svec, WA Wasielewski, MR TI Radical pair and triplet state dynamics of a photosynthetic reaction-center model embedded in isotropic media and liquid crystals SO JOURNAL OF THE AMERICAN CHEMICAL SOCIETY LA English DT Article ID ELECTRON-PARAMAGNETIC-RESONANCE; SPIN POLARIZATION; TRANSFER RATES; SPECTRA; SPECTROSCOPY; MIMICRY; ENERGY; ESR; RES; EPR AB The electron spin dynamics associated with intramolecular electron transfer in a photosynthetic model system, which consists of a linear structure of the type A-B-C, is described. In this structure, donor A is a p-methoxyaniline, chromophore B is a 4-amino-1,8-naphthalimide, and acceptor C is a 1,4:5,8-napththalenediimide. This supramolecular electron donor-acceptor array was isotropically oriented in toluene, and anisotropically oriented in liquid crystal matrices, and studied by time-resolved electron paramagnetic resonance spectroscopy. Photoexcitation of B results in a two-step electron transfer to yield the radical ion pair, A(.+)-B-C-.-. Charge recombination within A(.+)-B-C-.- produces a molecular triplet state, A-B-C-3*, which exhibits the unique spin-polarized electron paramagnetic resonance signal that has been observed only in photosynthetic reaction-center proteins. C1 HEBREW UNIV JERUSALEM,DEPT PHYS CHEM,IL-91004 JERUSALEM,ISRAEL. HEBREW UNIV JERUSALEM,FARKAS CTR LIGHT INDUCED PROC,IL-91004 JERUSALEM,ISRAEL. ARGONNE NATL LAB,DIV CHEM,ARGONNE,IL 60439. NORTHWESTERN UNIV,DEPT CHEM,EVANSTON,IL 60208. RI Gosztola, David/D-9320-2011 OI Gosztola, David/0000-0003-2674-1379 NR 39 TC 96 Z9 98 U1 0 U2 5 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 SN 0002-7863 J9 J AM CHEM SOC JI J. Am. Chem. Soc. PD OCT 23 PY 1996 VL 118 IS 42 BP 10228 EP 10235 DI 10.1021/ja961919e PG 8 WC Chemistry, Multidisciplinary SC Chemistry GA VN850 UT WOS:A1996VN85000025 ER PT J AU Bakac, A Wang, WD AF Bakac, A Wang, WD TI Biomimetic chemistry of chromium, intramolecular conversion of hydroperoxochromium(III) to oxochromium(V) SO JOURNAL OF THE AMERICAN CHEMICAL SOCIETY LA English DT Article ID OXIDATION REDUCTION REACTIONS; MACROCYCLIC LIGANDS; MOLECULAR-STRUCTURE; COMPLEXES; MECHANISMS; CATIONS; OXYGEN; ION RP Bakac, A (reprint author), IOWA STATE UNIV,AMES LAB,AMES,IA 50011, USA. NR 24 TC 27 Z9 27 U1 0 U2 3 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 SN 0002-7863 J9 J AM CHEM SOC JI J. Am. Chem. Soc. PD OCT 23 PY 1996 VL 118 IS 42 BP 10325 EP 10326 DI 10.1021/ja962418w PG 2 WC Chemistry, Multidisciplinary SC Chemistry GA VN850 UT WOS:A1996VN85000045 ER PT J AU Jones, ME Roadman, SE Lam, AM Eres, G Engstrom, JR AF Jones, ME Roadman, SE Lam, AM Eres, G Engstrom, JR TI Supersonic molecular beam studies of the dissociative chemisorption of GeH4 and Ge2H6 on the Ge(100) and Ge(111) surfaces SO JOURNAL OF CHEMICAL PHYSICS LA English DT Article ID SCANNING TUNNELING MICROSCOPY; THIN-FILM GROWTH; DESORPTION-KINETICS; PHASE-TRANSITION; PT(111) SURFACE; ADSORPTION; SI(100); ENERGY; SI2H6; CORRUGATION AB zThe reaction probabilities of GeH4 and Ge2H6 on the Ge(100) and Ge(111) surfaces have been measured as a function of substrate temperature, incident kinetic energy, and angle of incidence employing supersonic molecular beam scattering techniques. At sufficiently large incident kinetic energies (E(i)> 1 eV) both GeH4 and Ge2H6 react by direct dissociative chemisorption on both surfaces examined, with the reaction probability increasing approximately exponentially with increasing (scaled) incident kinetic energy. At moderate kinetic energies (E(i) similar to 0.4 eV), however, Ge2H6 reacts by a precursor-mediated mechanism on Ge(100), as demonstrated by a decrease in the reaction probability with either increasing substrate temperature or incident kinetic energy, Interestingly, under similar conditions, no evidence is found for precursor-mediated adsorption of Ge2H6 on the Ge(111) surface. The reaction of Ge2H6 does not exhibit a GeH4 production channel on either Ge(100) or Ge(111) for the conditions examined here. The results obtained at high incident kinetic energies (>1 eV) are well described by a statistical model based upon a Rice-Ramsperger-Kassel-Marcus (RRKM) framework. The moderate incident kinetic energy results for Ge2H6 on Ge(100) are well described by a model that assumes reaction via a trapping, precursor-mediated mechanism. (C) 1996 American Institute of Physics. C1 CORNELL UNIV,SCH CHEM ENGN,ITHACA,NY 14853. OAK RIDGE NATL LAB,DIV SOLID STATE,OAK RIDGE,TN 37831. RI Eres, Gyula/C-4656-2017 OI Eres, Gyula/0000-0003-2690-5214 NR 36 TC 20 Z9 20 U1 0 U2 2 PU AMER INST PHYSICS PI WOODBURY PA CIRCULATION FULFILLMENT DIV, 500 SUNNYSIDE BLVD, WOODBURY, NY 11797-2999 SN 0021-9606 J9 J CHEM PHYS JI J. Chem. Phys. PD OCT 22 PY 1996 VL 105 IS 16 BP 7140 EP 7151 DI 10.1063/1.472516 PG 12 WC Chemistry, Physical; Physics, Atomic, Molecular & Chemical SC Chemistry; Physics GA VM697 UT WOS:A1996VM69700050 ER PT J AU Bourke, MAM Vaidyanathan, R Dunand, DC AF Bourke, MAM Vaidyanathan, R Dunand, DC TI Neutron diffraction measurement of stress-induced transformation in superelastic NiTi SO APPLIED PHYSICS LETTERS LA English DT Article ID SHAPE MEMORY; SINGLE-CRYSTAL; DEFORMATION; MARTENSITE; BEHAVIOR; ALLOY AB The formation of stress-induced martensite in superelastic NiTi was studied by neutron diffraction during uniaxial compressive loading and unloading. The respective phase fractions were determined as a function of the applied stresses using a Rietveld refinement with a March-Dollase texture formulation. Before loading, the specimen was fully austenitic. At the highest applied stress of -625 MPa, about 90% of the austenitic phase had transformed to martensite, with a concomitant macroscopic strain of -2.8%. Upon unloading, all of the stress-induced martensite reverted to austenite and the totality of the macroscopic strain was recovered. The propensity for various austenitic crystallographic orientations to transform at different stresses was determined and qualitative observation of this incipient texture in the austenite and of the inherent texture in the nascent martensite are reported. (C) 1996 American Institute of Physics. C1 MIT,DEPT MAT SCI & ENGN,CAMBRIDGE,MA 02139. RP Bourke, MAM (reprint author), LOS ALAMOS NATL LAB,POB 1663,LOS ALAMOS,NM 87545, USA. RI Dunand, David/B-7515-2009; OI Dunand, David/0000-0001-5476-7379 NR 16 TC 32 Z9 33 U1 4 U2 10 PU AMER INST PHYSICS PI WOODBURY PA CIRCULATION FULFILLMENT DIV, 500 SUNNYSIDE BLVD, WOODBURY, NY 11797-2999 SN 0003-6951 J9 APPL PHYS LETT JI Appl. Phys. Lett. PD OCT 21 PY 1996 VL 69 IS 17 BP 2477 EP 2479 DI 10.1063/1.117503 PG 3 WC Physics, Applied SC Physics GA VN898 UT WOS:A1996VN89800009 ER PT J AU Aggarwal, S Dhote, AM Ramesh, R Warren, WL Pike, GE Dimos, D Raymond, MV Tuttle, BA Evans, JT AF Aggarwal, S Dhote, AM Ramesh, R Warren, WL Pike, GE Dimos, D Raymond, MV Tuttle, BA Evans, JT TI Hysteresis relaxation in (Pb,La)(Zr,Ti)O-3 thin film capacitors with (La,Sr)CoO3 electrodes SO APPLIED PHYSICS LETTERS LA English DT Article ID COEFFICIENT; OXIDES AB We report on the thermally activated hysteresis relaxation effects in (La,Sr)CoO3/ (Pb,La)(Zr,Ti)O-3/(La,Sr)CoO3 thin film ferroelectric capacitors. Films cooled in oxygen deficient ambients exhibit a marked voltage offset in the hysteresis loops. Upon the application of a dc bias voltage or undirectional pulses of the same polarity as the offset, the loops become more symmetric. Subsequently, holding the capacitors in the original preferred polarization state leads to a relaxation of the hysteresis loop towards its original voltage offset condition. The relaxation process is described by a stretched exponential and is thermally activated. (C) 1996 American Institute of Physics. C1 UNIV MARYLAND,CTR SUPERCONDUCT RES,COLLEGE PK,MD 20742. SANDIA NATL LABS,ALBUQUERQUE,NM 87185. RADIANT TECHNOL INC,ALBUQUERQUE,NM 87106. RP Aggarwal, S (reprint author), UNIV MARYLAND,DEPT MAT & NUCL ENGN,COLLEGE PK,MD 20742, USA. NR 16 TC 51 Z9 52 U1 2 U2 9 PU AMER INST PHYSICS PI WOODBURY PA CIRCULATION FULFILLMENT DIV, 500 SUNNYSIDE BLVD, WOODBURY, NY 11797-2999 SN 0003-6951 J9 APPL PHYS LETT JI Appl. Phys. Lett. PD OCT 21 PY 1996 VL 69 IS 17 BP 2540 EP 2542 DI 10.1063/1.117732 PG 3 WC Physics, Applied SC Physics GA VN898 UT WOS:A1996VN89800030 ER PT J AU Walukiewicz, W LilientalWeber, Z Jasinski, J Almonte, M Prasad, A Haller, EE Weber, ER Grenier, P Whitaker, JF AF Walukiewicz, W LilientalWeber, Z Jasinski, J Almonte, M Prasad, A Haller, EE Weber, ER Grenier, P Whitaker, JF TI High resistivity and ultrafast carrier lifetime in argon implanted GaAs SO APPLIED PHYSICS LETTERS LA English DT Article ID MOLECULAR-BEAM EPITAXY; LOW-TEMPERATURES AB We have investigated the optoelectronic and structural properties of GaAs that has been implanted with Ar ions and subsequently annealed, The material exhibits all the basic optical and electronic characteristics typically observed in nonstoichiometric. As implanted or low-temperature-grown GaAs. Annealing of Ar implanted GaAs at 600 degrees C produces a highly resistive material with a subpicosecond trapping lifetime for photoexcited carriers. Transmission electron microscopy shows that, instead of As precipitates, characteristic for the nonstoichiometeric GaAs, voids ranging in size from 3 to 5 nm are observed in Ar implanted and annealed GaAs. (C) 1996 American Institute of Physics. C1 UNIV MICHIGAN,CTR ULTRAFAST OPT SCI,ANN ARBOR,MI 48109. RP Walukiewicz, W (reprint author), UNIV CALIF BERKELEY,LAWRENCE BERKELEY NATL LAB,BERKELEY,CA 94720, USA. RI Liliental-Weber, Zuzanna/H-8006-2012 NR 17 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 SN 0003-6951 J9 APPL PHYS LETT JI Appl. Phys. Lett. PD OCT 21 PY 1996 VL 69 IS 17 BP 2569 EP 2571 DI 10.1063/1.117702 PG 3 WC Physics, Applied SC Physics GA VN898 UT WOS:A1996VN89800040 ER PT J AU Ekbundit, S Chizmeshya, A LaViolette, R Wolf, GH AF Ekbundit, S Chizmeshya, A LaViolette, R Wolf, GH TI Theoretical and experimental investigation of the equations of state and phase stabilities of MgS and CaS SO JOURNAL OF PHYSICS-CONDENSED MATTER LA English DT Article ID PRESSURE-INDUCED METALLIZATION; INDUCED BREATHING MODEL; ALKALINE-EARTH OXIDES; COMPRESSION; TRANSITION; CRYSTALS; ARGON; APPROXIMATION; CALIBRATION; TEMPERATURE AB The equations of state and phase stabilities of MgS and CaS are investigated via non-empirical theoretical calculations using three different electron-gas models: the self-consistent ion breathing (SCIB), the variationally induced breathing (VIE) and the potential-induced breathing (PIE) models. We apply these models on an equal footing using Kohn-Sham ionic densities and identical interaction density functionals. The calculated equations of state are compared to the compression curves of MgS at pressures up to 54 GPa and of CaS at pressures up to 52 GPa. The accuracies of the three electron-gas models in reproducing the equations of state of both compounds are generally comparable to those previously achieved for the binary oxide and halide systems. We also investigate the phase stabilities of MgS and CaS in CsCl (B2), wurtzite (B4) and zincblende (B3) structures. Our calculations accurately determine the B1-B2 phase transition for CaS. In the case of MgS, the transition pressure is much higher than that of the current experimental measurement ranges. In addition, the models predict that the B4 phases of MgS and CaS can be stabilized under moderate tensions. This result is consistent with experimental observation of epitaxially stabilized MgS wurtzite films. C1 EG&G IDAHO INC,IDAHO NATL ENGN LAB,IDAHO FALLS,ID 83415. RP Ekbundit, S (reprint author), ARIZONA STATE UNIV,DEPT CHEM,TEMPE,AZ 85287, USA. NR 42 TC 24 Z9 24 U1 0 U2 4 PU IOP PUBLISHING LTD PI BRISTOL PA TECHNO HOUSE, REDCLIFFE WAY, BRISTOL, ENGLAND BS1 6NX SN 0953-8984 J9 J PHYS-CONDENS MAT JI J. Phys.-Condes. Matter PD OCT 21 PY 1996 VL 8 IS 43 BP 8251 EP 8265 DI 10.1088/0953-8984/8/43/018 PG 15 WC Physics, Condensed Matter SC Physics GA VP694 UT WOS:A1996VP69400018 ER PT J AU Seaborg, GT AF Seaborg, GT TI Evolution of the modern periodic table SO JOURNAL OF THE CHEMICAL SOCIETY-DALTON TRANSACTIONS LA English DT Article ID LIQUID-LIQUID EXTRACTIONS; GAS-PHASE CHROMATOGRAPHY; DIRAC-FOCK CALCULATIONS; IONIZATION-POTENTIALS; SOLUTION CHEMISTRY; ELEMENT-104; TANTALUM; RADII; ATOMS; IONS AB In this review, the evolution of the Modern Periodic Table is traced beginning with the original version of Dimitri Mendeleev in 1869. Emphasis is placed on the upper end with a description of the revision to accommodate the actinide series of elements at the time of World War II and the more recent research on the observed and predicted chemical properties of the transactinide elements (beyond atomic number 103). A Modern Periodic Table includes undiscovered elements up to atomic number 118 and a Futuristic Periodic Table with additional undiscovered elements up to atomic number 168 is included. RP Seaborg, GT (reprint author), UNIV CALIF BERKELEY,ERNEST ORLANDO LAWRENCE BERKELEY NATL LAB,BERKELEY,CA 94720, USA. NR 68 TC 5 Z9 5 U1 4 U2 11 PU ROYAL SOC CHEMISTRY PI CAMBRIDGE PA THOMAS GRAHAM HOUSE, SCIENCE PARK MILTON ROAD, CAMBRIDGE, CAMBS, ENGLAND CB4 4WF SN 0300-9246 J9 J CHEM SOC DALTON JI J. Chem. Soc.-Dalton Trans. PD OCT 21 PY 1996 IS 20 BP 3899 EP 3907 DI 10.1039/dt9960003899 PG 9 WC Chemistry, Inorganic & Nuclear SC Chemistry GA VR248 UT WOS:A1996VR24800001 ER PT J AU Markovic, NM Sarraf, ST Gasteiger, HA Ross, PN AF Markovic, NM Sarraf, ST Gasteiger, HA Ross, PN TI Hydrogen electrochemistry on platinum low-index single-crystal surfaces in alkaline solution SO JOURNAL OF THE CHEMICAL SOCIETY-FARADAY TRANSACTIONS LA English DT Article ID EVOLUTION REACTION; ACID-SOLUTION; ADSORPTION; ELECTRODES; INTERFACE; PT(100) AB The results of a study of the hydrogen evolution reaction (HER) and the hydrogen oxidation reaction (HOR) on the three low-index faces of Pt in alkaline solution are presented. The study features a new method for the use of Pt single crystals in a rotating disk electrode (RDE) configuration. At low negative overpotentials, the order of activity for the HER increased in the sequence (111)<(100)<(110). At low positive overpotentials, the order of activity for the HOR increased in the sequence (111)approximate to(100)much less than(110). These differences in activity with crystal face are attributed to different states of adsorbed hydrogen and to different effects of these states on the mechanism of the hydrogen reaction. Two different types of adsorbed hydrogen are observed on Pt(hkl) surfaces. A high binding energy state, often referred to as underpotential deposited hydrogen, H-upd, has an inhibiting (site blocking) effect on the rate of the HER and HOR. A low binding energy state is a reaction intermediate at low overpotentials in both the HOR as well as the HER, and is most prevalent on the (110) surface. At high positive overpotentials, in the potential region where adsorption of hydroxy species (OHad) occurs, the effects of surface crystallography on the HOR is attributed to the structural sensitivity of the adsorption of OHad on Pt(hkl), with OHad having an inhibiting effect on the HOR, the inhibition decreasing in the sequence (100)much less than(110)<(111). RP Markovic, NM (reprint author), UNIV CALIF BERKELEY,LAWRENCE BERKELEY LAB,DIV MAT SCI,BERKELEY,CA 94720, USA. NR 29 TC 151 Z9 151 U1 11 U2 79 PU ROYAL SOC CHEMISTRY PI CAMBRIDGE PA THOMAS GRAHAM HOUSE, SCIENCE PARK MILTON ROAD, CAMBRIDGE, CAMBS, ENGLAND CB4 4WF SN 0956-5000 J9 J CHEM SOC FARADAY T JI J. Chem. Soc.-Faraday Trans. PD OCT 21 PY 1996 VL 92 IS 20 BP 3719 EP 3725 DI 10.1039/ft9969203719 PG 7 WC Chemistry, Physical; Physics, Atomic, Molecular & Chemical SC Chemistry; Physics GA VT016 UT WOS:A1996VT01600007 ER PT J AU Ball, J Combet, M Sans, JL Benda, B Chaumette, P Deregel, J Durand, G Dzyubak, AP Gaudron, C Lehar, F Lesquen, A Kasprzyk, TE Janout, Z Khachaturov, BA Matafonov, VN Usov, YA AF Ball, J Combet, M Sans, JL Benda, B Chaumette, P Deregel, J Durand, G Dzyubak, AP Gaudron, C Lehar, F Lesquen, A Kasprzyk, TE Janout, Z Khachaturov, BA Matafonov, VN Usov, YA TI Proton and neutron polarized targets for nucleon-nucleon experiments at SATURNE II SO NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH SECTION A-ACCELERATORS SPECTROMETERS DETECTORS AND ASSOCIATED EQUIPMENT LA English DT Article ID ELASTIC-SCATTERING; ANALYZING POWER; NP AB A SATURNE polarized target has been used far nucleon-nucleon elastic scattering and transmission experiments for 15 years, Continuous improvements resulted in a flexible and reliable facility for spin physics. The polarized proton target was a 70 cm(3) cartridge loaded with pentanol-2, a promising material according to the results obtained. The new acquisition system and dal-a processing was based on the LabView/PC software and increased the accuracy of polarization measurements. For a polarized neutron target, two cartridges loaded with (LiD)-Li-6 and (LiH)-Li-6 were set in the refrigerator and could be quickly inserted in the beam. Results from the the first experiments using Li-6 materials in quasielastic pp or pn analyzing power measurements are compared with the same observables measured in free nucleon-nucleon scattering using polarized proton targets. The angular resolution distributions for theta(CM) determination and azimuthal coplanarity are shown for different targets in nucleon-nucleon scattering. A comparison of analyzing power results for elastic and quasielastic scattering suggests that the contribution of inelastic processes to quasielastic pn scattering may be suppressed by additional constraints. C1 CE SACLAY,CEA,DSM,F-91191 GIF SUR YVETTE,FRANCE. CE SACLAY,CEA,DAPNIA,F-91191 GIF SUR YVETTE,FRANCE. ARGONNE NATL LAB,HEP,ARGONNE,IL 60439. JOINT INST NUCL RES,LAB NUCL PROBLEMS,DUBNA 141980,RUSSIA. RP Ball, J (reprint author), CNRS IN2P3,LAB NATL SATURNE,F-91191 GIF SUR YVETTE,FRANCE. NR 24 TC 19 Z9 19 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 OCT 21 PY 1996 VL 381 IS 1 BP 4 EP 14 DI 10.1016/0168-9002(96)00642-0 PG 11 WC Instruments & Instrumentation; Nuclear Science & Technology; Physics, Nuclear; Physics, Particles & Fields SC Instruments & Instrumentation; Nuclear Science & Technology; Physics GA VU096 UT WOS:A1996VU09600002 ER PT J AU Pehl, RH Hull, EL Madden, NW Xing, JS Friesel, DL AF Pehl, RH Hull, EL Madden, NW Xing, JS Friesel, DL TI Gamma-ray escape peak characteristics of radiation-damaged reverse-electrode germanium coaxial detectors SO NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH SECTION A-ACCELERATORS SPECTROMETERS DETECTORS AND ASSOCIATED EQUIPMENT LA English DT Article DE germanium; detector; gamma-ray; escape-peak; radiation damage AB A comparison of the characteristics of full-energy gamma-ray peaks and their corresponding escape peaks when high energy photons interact in radiation damaged reverse-electrode (n-type) germanium coaxial detectors is presented. Coaxial detector geometry is the dominant factor, causing charge collection to be dramatically better for interactions occurring near the outer periphery of the detector as well as increasing of the probability of escape events occurring in this region. It follows that the resolution of escape peaks is better than that of ordinary gamma-ray peaks. This is experimentally verified. A nearly identical but undamaged detector exhibited significant Doppler broadening of single escape peaks. Because double escape events preferentially occur at outer radii, energy shifts of double escape reflect extremely small amounts of charge trapping in undamaged detectors. C1 INDIANA UNIV,CYCLOTRON FACIL,BLOOMINGTON,IN 47408. RP Pehl, RH (reprint author), UNIV CALIF BERKELEY,LAWRENCE BERKELEY LAB,BERKELEY,CA 94720, USA. NR 11 TC 6 Z9 6 U1 0 U2 0 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0168-9002 J9 NUCL INSTRUM METH A JI Nucl. Instrum. Methods Phys. Res. Sect. A-Accel. Spectrom. Dect. Assoc. Equip. PD OCT 21 PY 1996 VL 381 IS 1 BP 97 EP 102 DI 10.1016/0168-9002(96)00648-1 PG 6 WC Instruments & Instrumentation; Nuclear Science & Technology; Physics, Nuclear; Physics, Particles & Fields SC Instruments & Instrumentation; Nuclear Science & Technology; Physics GA VU096 UT WOS:A1996VU09600014 ER PT J AU Kane, GL Mrenna, S AF Kane, GL Mrenna, S TI Do about half the top quarks at Fermilab come from gluino decays? SO PHYSICAL REVIEW LETTERS LA English DT Article ID STANDARD MODEL; ROOT-S=1.8 TEV; SUPERSYMMETRY; COLLISIONS; SEARCH; SUPERPARTNERS; TEVATRON AB We argue that it is possible to make a consistent picture of Fermilab data including the production and decay of gluinos and squarks. Assuming the stop squark mass is small enough, about half of the top quarks decay to stop squarks, and the loss of standard model top quark pair production rate is compensated by the supersymmetric processes. This behavior is consistent with the reported top quark decay data and suggests several other possible decay signatures. This picture can be tested easily with more data, perhaps even with the data in hand. It also has implications for the top mass measurement and the interpretation of the CERN e(+)e(-) collider LEP R(b) excess. C1 ARGONNE NATL LAB,DIV HIGH ENERGY PHYS,ARGONNE,IL 60439. RP Kane, GL (reprint author), UNIV MICHIGAN,RANDALL LAB PHYS,ANN ARBOR,MI 48104, USA. NR 38 TC 38 Z9 38 U1 0 U2 0 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 0031-9007 J9 PHYS REV LETT JI Phys. Rev. Lett. PD OCT 21 PY 1996 VL 77 IS 17 BP 3502 EP 3505 DI 10.1103/PhysRevLett.77.3502 PG 4 WC Physics, Multidisciplinary SC Physics GA VM890 UT WOS:A1996VM89000004 ER PT J AU Barnett, RM Hall, LJ AF Barnett, RM Hall, LJ TI Multilepton signal for supersymmetric particles in the Fermilab Tevatron data? SO PHYSICAL REVIEW LETTERS LA English DT Article ID PPBAR COLLIDER; SQUARK DECAYS; TOP-QUARK; GLUINOS AB The CDF and DO Collaborations have both reported unusual events in the dilepton + jets sample with very high lepton and missing transverse energies. It is possible, but very unlikely, that these events originate from top quark pair production; however, they have characteristics that are better accounted for by decays of supersymmetric quarks with mass in the region of 300 GeV: (q) over tilde-->q<(chi)over tilde>, <(chi)over tilde>-->nu (l) over tilde, (l) over tilde-->l<(chi)over tilde(1)(0)> Such a supersymmetric origin also leads to events with large missing transverse energy and either 0, 1, 2 same-sign, or 3 isolated charged leptons. C1 UNIV CALIF BERKELEY,DEPT PHYS,BERKELEY,CA 94720. RP Barnett, RM (reprint author), UNIV CALIF BERKELEY,LAWRENCE BERKELEY LAB,BERKELEY,CA 94720, USA. NR 16 TC 13 Z9 13 U1 0 U2 0 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 0031-9007 J9 PHYS REV LETT JI Phys. Rev. Lett. PD OCT 21 PY 1996 VL 77 IS 17 BP 3506 EP 3509 DI 10.1103/PhysRevLett.77.3506 PG 4 WC Physics, Multidisciplinary SC Physics GA VM890 UT WOS:A1996VM89000005 ER PT J AU Orzechowski, TJ Rosen, MD Kornblum, HN Porter, JL Suter, LJ Thiessen, AR Wallace, RJ AF Orzechowski, TJ Rosen, MD Kornblum, HN Porter, JL Suter, LJ Thiessen, AR Wallace, RJ TI The Rosseland mean opacity of a mixture of gold and gadolinium at high temperatures SO PHYSICAL REVIEW LETTERS LA English DT Article ID INERTIAL CONFINEMENT FUSION; IGNITION; PLASMAS AB Radiation transport through high-opacity materials can be described using the Rosseland mean opacity of the medium, which is dominated by low-opacity regions in the frequency-dependent: opacity. By mixing gold and gadolinium, we can fill in low-opacity regions of one material;with high-opacity regions of another material, resulting in a material with a Rosseland mean opacity 1.5x higher than either of the constituents. For a given laser energy, this can raise the temperature of the laser heated hohlraums, or for a given desired temperature, require less laser energy. RP Orzechowski, TJ (reprint author), LAWRENCE LIVERMORE NATL LAB,POB 808,LIVERMORE,CA 94550, USA. NR 18 TC 83 Z9 92 U1 2 U2 8 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 0031-9007 J9 PHYS REV LETT JI Phys. Rev. Lett. PD OCT 21 PY 1996 VL 77 IS 17 BP 3545 EP 3548 DI 10.1103/PhysRevLett.77.3545 PG 4 WC Physics, Multidisciplinary SC Physics GA VM890 UT WOS:A1996VM89000015 ER PT J AU Chang, Z Park, W Fredrickson, ED Batha, SH Bell, MG Bell, R Budny, RV Bush, CE Janos, A Levinton, FM McGuire, KM Park, H Sabbagh, SA Schmidt, GL Scott, SD Synakowski, EJ Takahashi, H Taylor, G Zarnstorff, MC AF Chang, Z Park, W Fredrickson, ED Batha, SH Bell, MG Bell, R Budny, RV Bush, CE Janos, A Levinton, FM McGuire, KM Park, H Sabbagh, SA Schmidt, GL Scott, SD Synakowski, EJ Takahashi, H Taylor, G Zarnstorff, MC TI Off-axis sawteeth and double-tearing reconnection in reversed magnetic shear plasmas in TFTR SO PHYSICAL REVIEW LETTERS LA English DT Article AB Off-axis sawteeth are often observed in reversed magnetic shear plasmas when the minimum safety factor q is near or below 2. Fluctuations with m/n=2/1 (m and n are the poloidal and toroidal mode numbers) appear before and after the crashes. Detailed comparison has been made between the measured T-e profile evaluation during the crash and a nonlinear numerical magnetohydrodynamics simulation. The good agreement between observation and simulation indicates that the off-axis sawteeth are due to a double-tearing magnetic reconnection process. C1 COLUMBIA UNIV,NEW YORK,NY 10027. RP Chang, Z (reprint author), PRINCETON UNIV,PLASMA PHYS LAB,POB 451,PRINCETON,NJ 08543, USA. RI Sabbagh, Steven/C-7142-2011 NR 12 TC 88 Z9 88 U1 1 U2 7 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 0031-9007 J9 PHYS REV LETT JI Phys. Rev. Lett. PD OCT 21 PY 1996 VL 77 IS 17 BP 3553 EP 3556 DI 10.1103/PhysRevLett.77.3553 PG 4 WC Physics, Multidisciplinary SC Physics GA VM890 UT WOS:A1996VM89000017 ER PT J AU Filuk, AB Bailey, JE Carlson, AL Johnson, DJ Lake, P Mehlhorn, TA Mix, LP Renk, TJ Stygar, WA Maron, Y AF Filuk, AB Bailey, JE Carlson, AL Johnson, DJ Lake, P Mehlhorn, TA Mix, LP Renk, TJ Stygar, WA Maron, Y TI Charge-exchange atoms and ion source divergence in a 20 TW applied-B ion diode SO PHYSICAL REVIEW LETTERS LA English DT Article ID VELOCITY DISTRIBUTION; BEAMS; PROTON; FIELDS; GAP AB Space- and time-resolved spectroscopy is used to measure properties of several-keV Li atoms in a 20 TW ion diode. These measurements but in the diode anode-cathode gap are used in a charge-exchange model for the Li atom production in order to obtain the Li+ beam angular divergence within 50 mu m of the LiF-coated anode surface. This ion divergence near the surface is surprisingly large, and accounts for about half the typical 25 mrad final accelerated-beam divergence. The measurements provide constraints for models attempting to explain highly diverging ion emission from thin alkali-halide films in similar to 10 MV/cm applied fields. C1 WEIZMANN INST SCI,IL-76100 REHOVOT,ISRAEL. RP Filuk, AB (reprint author), SANDIA NATL LABS,POB 5800,ALBUQUERQUE,NM 87185, USA. NR 26 TC 13 Z9 13 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 OCT 21 PY 1996 VL 77 IS 17 BP 3557 EP 3560 DI 10.1103/PhysRevLett.77.3557 PG 4 WC Physics, Multidisciplinary SC Physics GA VM890 UT WOS:A1996VM89000018 ER PT J AU Yatskar, A Beyermann, WP Movshovich, R Canfield, PC AF Yatskar, A Beyermann, WP Movshovich, R Canfield, PC TI Possible correlated-electron behavior from quadrupolar fluctuations in PrInAg2 SO PHYSICAL REVIEW LETTERS LA English DT Article ID FERMI-LIQUID BEHAVIOR; HEAT-CAPACITY; KONDO; INSTABILITY; ALLOYS; SUSCEPTIBILITY; Y1-XUXPD3; SAMPLES; PR; PD AB The temperature dependent magnetic susceptibility; specific heat, and electrical resistivity were measured on PrInAg2. A broad peak, which is identified as a Kondo anomaly, is observed in the specific heat at similar to 0.4 K with a strongly enhanced linear contribution at lower temperatures. PrInAg2 is a Pr-based heavy-fermion compound and has one of the largest known Sommerfeld coefficients of similar to 6.5 J/mol K-2. A new type of nonmagnetic interaction between the conduction electrons and the non-Kramers doublet ground state of the Pr3+ ion be responsible for this behavior. Related features are also observed in the susceptibility and resistivity. C1 LOS ALAMOS NATL LAB,LOS ALAMOS,NM 87545. AMES LAB,AMES,IA 50011. IOWA STATE UNIV SCI & TECHNOL,AMES,IA 50011. RP Yatskar, A (reprint author), UNIV CALIF RIVERSIDE,RIVERSIDE,CA 92521, USA. RI Canfield, Paul/H-2698-2014 NR 31 TC 119 Z9 119 U1 2 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 OCT 21 PY 1996 VL 77 IS 17 BP 3637 EP 3640 DI 10.1103/PhysRevLett.77.3637 PG 4 WC Physics, Multidisciplinary SC Physics GA VM890 UT WOS:A1996VM89000038 ER PT J AU Hill, JP Kao, CC Caliebe, WAC Gibbs, D Hastings, JB AF Hill, JP Kao, CC Caliebe, WAC Gibbs, D Hastings, JB TI Inelastic X-ray scattering study of solid and liquid Li and Na SO PHYSICAL REVIEW LETTERS LA English DT Article ID DYNAMIC STRUCTURE FACTOR; ELECTRON LIQUID; BAND-STRUCTURE; AL METAL; BERYLLIUM; ALUMINUM; PLASMONS AB We present the first measurements of the dynamic structure factor of lithium and sodium in the liquid and solid phases, in the intermediate-q regime. The overall shape of the response function is little changed on melting, implying that it is not determined by the long range order of the ion cores. Conversely, fine structure, observed in the Li data, disappears on melting, and is attributed to band-structure-induced transitions. At small q, the plasmon lifetime and dispersion remain unchanged on melting. C1 BROOKHAVEN NATL LAB,UPTON,NY 11973. RP Hill, JP (reprint author), BROOKHAVEN NATL LAB,DEPT PHYS,UPTON,NY 11973, USA. RI Hill, John/F-6549-2011 NR 35 TC 46 Z9 46 U1 2 U2 9 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 0031-9007 J9 PHYS REV LETT JI Phys. Rev. Lett. PD OCT 21 PY 1996 VL 77 IS 17 BP 3665 EP 3668 DI 10.1103/PhysRevLett.77.3665 PG 4 WC Physics, Multidisciplinary SC Physics GA VM890 UT WOS:A1996VM89000045 ER PT J AU Tessarotto, M Johnson, JL Zheng, LJ AF Tessarotto, M Johnson, JL Zheng, LJ TI Omnigenous transport barriers in MHD equilibria SO PHYSICS LETTERS A LA English DT Article ID ION-TRANSPORT; PLASMAS; TOKAMAK AB It is proven that quasi-helical magnetohydrodynamic equilibria can be constructed to be locally omnigenous, i.e., so that the cross-field component of the particle drift velocity vanishes on a suitable magnetic surface. This property also holds in the presence of strong drifts producing subsonic quasi-helically symmetric hows. Analogous conditions are investigated for generic stellarator and tokamak equilibria in the presence of flow. Such equilibria, exhibiting a local transport barrier, are potentially relevant for magnetic confinement. C1 PRINCETON UNIV, PRINCETON PLASMA PHYS LAB, PRINCETON, NJ 08543 USA. RP Tessarotto, M (reprint author), UNIV TRIESTE, DEPT MATH SCI, I-34127 TRIESTE, ITALY. NR 23 TC 0 Z9 0 U1 0 U2 1 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0375-9601 J9 PHYS LETT A JI Phys. Lett. A PD OCT 21 PY 1996 VL 222 IS 1-2 BP 101 EP 106 DI 10.1016/0375-9601(96)00632-9 PG 6 WC Physics, Multidisciplinary SC Physics GA VL141 UT WOS:A1996VL14100018 ER PT J AU Miles, PC AF Miles, PC TI Geometry of the fringe field formed in the intersection of two Gaussian beams SO APPLIED OPTICS LA English DT Article DE interference fringes; Gaussian beams; laser Doppler velocimetry AB A general expression is obtained for the exact computation of the fringe field in the intersection volume of two paraxial Gaussian beams for arbitrary beam waist positions and sizes. The expression is then simplified to allow easy fringe field computation while retaining good accuracy. By relating the simplified expression to the system parameters relevant to dual-beam laser Doppler velocimeters, simple design equations are obtained. These equations permit rapid evaluation of the fringe field variation along the major and minor axes of the intersection volume and clearly identify the system parameters controlling this variation. (C) 1996 Optical Society of America RP Miles, PC (reprint author), SANDIA NATL LABS,COMBUST RES FACIL,POB 969,LIVERMORE,CA 94551, USA. NR 6 TC 31 Z9 32 U1 1 U2 3 PU OPTICAL SOC AMER PI WASHINGTON PA 2010 MASSACHUSETTS AVE NW, WASHINGTON, DC 20036 SN 0003-6935 J9 APPL OPTICS JI Appl. Optics PD OCT 20 PY 1996 VL 35 IS 30 BP 5887 EP 5895 DI 10.1364/AO.35.005887 PG 9 WC Optics SC Optics GA VN212 UT WOS:A1996VN21200004 PM 21127599 ER PT J AU Sutton, SB Albrecht, GF AF Sutton, SB Albrecht, GF TI Simple analytical method to calculate the radial energy deposition profile in an isotropic diode-pumped solid-state laser rod SO APPLIED OPTICS LA English DT Article AB We provide an approximate hut simple analytical solution to the radial distribution of deposited energy in a diode-array-pumped laser rod, subject to some assumptions that are naturally fulfilled for most applications of practical interest. The solution is useful to survey quickly irradiance distributions for a wide variety of pumping geometries and to find the radially most uniform energy deposition. We find that the radial deposition profile, as well as the pump light absorption efficiency, is largely controlled by just two dimensionless parameters: the number of absorption depths and the ratio of the width of the unabsorbed pump beam at the rod center divided by the rod radius. A side-by-side comparison with a numerical model is given. Results describing the best achievable trade-off between absorption efficiency and pumping uniformity are presented in the form of a recipe that can be followed without studying our research in detail. Finally, the model equations are applied to a practical side-pumped geometry. RP Sutton, SB (reprint author), LAWRENCE LIVERMORE NATL LAB,POB 808,LIVERMORE,CA 94550, USA. NR 8 TC 16 Z9 22 U1 0 U2 3 PU OPTICAL SOC AMER PI WASHINGTON PA 2010 MASSACHUSETTS AVE NW, WASHINGTON, DC 20036 SN 0003-6935 J9 APPL OPTICS JI Appl. Optics PD OCT 20 PY 1996 VL 35 IS 30 BP 5937 EP 5948 DI 10.1364/AO.35.005937 PG 12 WC Optics SC Optics GA VN212 UT WOS:A1996VN21200010 PM 21127605 ER PT J AU Kogut, A Banday, AJ Bennett, CL Gorski, KM Hinshaw, G Jackson, PD Keegstra, P Lineweaver, C Smoot, GF Tenorio, L Wright, EL AF Kogut, A Banday, AJ Bennett, CL Gorski, KM Hinshaw, G Jackson, PD Keegstra, P Lineweaver, C Smoot, GF Tenorio, L Wright, EL TI Calibration and systematic error analysis for the COBE(1) DMR 4 year sky maps SO ASTROPHYSICAL JOURNAL LA English DT Article DE cosmic microwave background; instrumentation, detectors; radio continuum, general; space vehicles ID DIFFERENTIAL MICROWAVE RADIOMETERS; DESIGN AB The Differential Microwave Radiometers (DMR) instrument aboard the Cosmic Background Explorer (COBE) has mapped the full microwave sky to mean sensitivity 26 mu K per 7 degrees held of view. The absolute calibration is determined to 0.7% with drifts smaller than 0.2% per year. We have analyzed both the raw differential data and the pixelized sky maps for evidence of contaminating sources such as solar system foregrounds, instrumental susceptibilities, and artifacts from data recovery and processing. Most systematic effects couple only weakly to the sky maps. The largest uncertainties in the maps result from the instrument susceptibility to Earth's magnetic field, microwave emission from Earth, and upper limits to potential effects at the spacecraft spin period. Systematic effects in the maps are small compared to either the noise or the celestial signal: the 95% confidence upper limit for the pixel-pixel rms from all identified systematics is less than 6 mu K in the worst channel. A power spectrum analysis of the (A-B)/2 difference maps shows no evidence for additional undetected systematic effects. C1 UNIV CALIF BERKELEY, LAWRENCE BERKELEY LAB, BERKELEY, CA 94720 USA. UNIV CALIF BERKELEY, SPACE SCI LAB, BERKELEY, CA 94720 USA. UNIV CALIF BERKELEY, CFPA, BERKELEY, CA 94720 USA. UNIV CALIF LOS ANGELES, LOS ANGELES, CA 90095 USA. RP Kogut, A (reprint author), NASA, GODDARD SPACE FLIGHT CTR, HUGHES STX CORP, ASTRON & SOLAR PHYS LAB, CODE 685, GREENBELT, MD 20771 USA. RI Kogut, Alan/D-6293-2012 NR 23 TC 38 Z9 38 U1 0 U2 0 PU IOP PUBLISHING LTD PI BRISTOL PA TEMPLE CIRCUS, TEMPLE WAY, BRISTOL BS1 6BE, ENGLAND SN 0004-637X J9 ASTROPHYS J JI Astrophys. J. PD OCT 20 PY 1996 VL 470 IS 2 BP 653 EP 673 DI 10.1086/177898 PN 1 PG 21 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA VM998 UT WOS:A1996VM99800001 ER PT J AU Minniti, D Peterson, RC Geisler, D Claria, JJ AF Minniti, D Peterson, RC Geisler, D Claria, JJ TI High-dispersion spectroscopy of giants in metal-poor globular clusters .2. Oxygen and sodium abundances SO ASTROPHYSICAL JOURNAL LA English DT Article DE globular clusters, general; stars, abundances; stars, Population II ID H-ALPHA EMISSION; HALO GIANTS; RED GIANTS; MASS-LOSS; STARS; M13; FIELD; AGE; METALLICITY; SYSTEM AB Oxygen and sodium abundances or upper limits have been determined for 17 red giant members of the metal-poor Galactic globular clusters M68 (two stars), M30 (two stars), M15 (two stars), M55 (two stars), and NGC 6397 (five stars), as well as for the moderately metal-poor clusters NGC 4833 (one star), NGC 6144 (one star), and NGC 6752 (three stars). The behavior of [O/Fe] with respect to luminosity and metallicity is investigated. As found in previous works, the oxygen-to-iron ratios show an upper envelope, in agreement with the mean level of field halo stars of similar metallicities ([O/ Fe] = +0.4 +/- 0.15). Moreover, as is true of the more metal-rich giants in globular clusters, about one-third of the stars do not have enhanced oxygen with respect to iron, in contrast to held giants of similar metallicity, which are almost invariably oxygen-rich. Several explanations for this deficiency are examined, including emission possibly associated with mass-loss filling in the oxygen lines and evolutionary mixing effects. In particular, the abundances of oxygen and sodium are seen to be anticorrelated, in agreement with previous results (Kraft et al. 1995). The enhancement of oxygen in these extremely metal-poor clusters appears similar to that of less metal-deficient clusters, an important datum for determinations of their relative ages. C1 EUROPEAN SO OBSERV, D-85748 GARCHING, GERMANY. UNIV CALIF SANTA CRUZ, UNIV CALIF OBSERV, LICK OBSERV, SANTA CRUZ, CA 95064 USA. CERRO TOLOLO INTERAMER OBSERV, LA SERENA, CHILE. ASTRON OBSERV, RA-5000 CORDOBA, ARGENTINA. RP Minniti, D (reprint author), LAWRENCE LIVERMORE NATL LAB, POB 808, MS L-413, LIVERMORE, CA 94550 USA. NR 50 TC 28 Z9 28 U1 0 U2 0 PU IOP PUBLISHING LTD PI BRISTOL PA TEMPLE CIRCUS, TEMPLE WAY, BRISTOL BS1 6BE, ENGLAND SN 0004-637X J9 ASTROPHYS J JI Astrophys. J. PD OCT 20 PY 1996 VL 470 IS 2 BP 953 EP 960 DI 10.1086/177921 PN 1 PG 8 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA VM998 UT WOS:A1996VM99800024 ER PT J AU Ellis, J Fields, BD Schramm, DN AF Ellis, J Fields, BD Schramm, DN TI Geological isotope anomalies as signatures of nearby supernovae SO ASTROPHYSICAL JOURNAL LA English DT Article DE Earth; nuclear reactions, nucleosynthesis, abundances; supernovae, general ID ENHANCED BE-10 DEPOSITION; EARLY SOLAR-SYSTEM; ANTARCTIC ICE; GEMINGA; NUCLEOSYNTHESIS; EXTINCTION; PERIOD; BUBBLE; 1987A AB Nearby supernova explosions may cause geological isotope anomalies via the direct deposition of debris or by cosmic-ray spallation in the Earth's atmosphere. We estimate the mass of material deposited terrestrially by these two mechanisms, showing the dependence on the supernova distance. A number of radioactive isotopes are identified as possible diagnostic tools, such as Be-10, Al-26, Cl-36, Mn-53, Fe-60, and Ni-59, as well as the longer-lived I-129, Sm-146, and Pu-244. We discuss whether the 35 and 60 kyr old Be-10 anomalies observed in the Vostok Antarctic ice cores could be due to supernova explosions. Combining our estimates for matter deposition with results of recent nucleosynthesis yields, we calculate the expected signal from nearby supernovae using ice cores back to O(300) kyr ago, and we discuss using deep-ocean sediments back to several hundred Myr. In particular, we examine the prospects for identifying isotope anomalies due to the Geminga supernova explosion, and signatures of the possibility that supernovae might have caused one or more biological mass extinctions. C1 UNIV NOTRE DAME,DEPT PHYS,NOTRE DAME,IN 46556. UNIV CHICAGO,CHICAGO,IL 60637. INST ASTROPHYS PARIS,F-75014 PARIS,FRANCE. FERMILAB NATL ACCELERATOR LAB,NASA,FERMILAB ASTROPHYS CTR,BATAVIA,IL 60510. RP Ellis, J (reprint author), CERN,DIV THEORET PHYS,CH-1211 GENEVA,SWITZERLAND. NR 45 TC 65 Z9 65 U1 1 U2 5 PU UNIV CHICAGO PRESS PI CHICAGO PA 5720 S WOODLAWN AVE, CHICAGO, IL 60637 SN 0004-637X J9 ASTROPHYS J JI Astrophys. J. PD OCT 20 PY 1996 VL 470 IS 2 BP 1227 EP 1236 DI 10.1086/177945 PN 1 PG 10 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA VM998 UT WOS:A1996VM99800048 ER PT J AU Dentener, FJ Carmichael, GR Zhang, Y Lelieveld, J Crutzen, PJ AF Dentener, FJ Carmichael, GR Zhang, Y Lelieveld, J Crutzen, PJ TI Role of mineral aerosol as a reactive surface in the global troposphere SO JOURNAL OF GEOPHYSICAL RESEARCH-ATMOSPHERES LA English DT Review ID MASS ACCOMMODATION COEFFICIENT; GENERAL-CIRCULATION MODEL; DUST-STORM PARTICLES; NORTH PACIFIC-OCEAN; SEA-SALT AEROSOLS; SAHARAN DUST; ASIAN DUST; HETEROGENEOUS REACTIONS; TEMPERATURE-DEPENDENCE; TEMPORAL VARIABILITY AB A global three-dimensional model of the troposphere is used to simulate the sources, abundances, and sinks of mineral aerosol and the species involved in the photochemical oxidant, nitrogen, and sulfur cycles. Although the calculated heterogeneous removal rates on mineral aerosol are highly uncertain, mainly due to poorly known heterogeneous reaction rates, the reaction of SO2 on calcium-rich mineral aerosol is likely to play an important role downwind of arid source regions. This is especially important for regions in Asia, which are important and increasing emitters of sulfur compounds. Our results indicate that the assumption that sulfate aerosol follows an accumulation mode size distribution, is particularly in Asia likely to overestimate the sulfate aerosol climate-cooling effect. An even larger fraction of gas phase nitric acid may be associated with and neutralized by mineral aerosol. Interactions of N2O5, O-3, and HO2-radicals with dust are calculated to affect the photochemical oxidant cycle, causing ozone decreases up to 10% in and nearby the dust source areas. Comparison of these results with limited available measurements indicates that the proposed reactions can indeed take place, although due to a lack of measurements a rigorous evaluation is not possible at this time. C1 AGR UNIV WAGENINGEN, DEPT AIR QUAL, WAGENINGEN, NETHERLANDS. UNIV IOWA, DEPT CHEM & BIOCHEM ENGN, IOWA CITY, IA 52240 USA. UNIV IOWA, CTR GLOBAL & REG ENVIRONM RES, IOWA CITY, IA 52240 USA. PACIFIC NW LAB, ENVIRONM & ENERGY SCI DIV, RICHLAND, WA 99352 USA. MAX PLANCK INST CHEM, D-55020 MAINZ, GERMANY. RP Dentener, FJ (reprint author), INST MARINE & ATMOSPHER RES, PRINCETONPLEIN 5, NL-3584 CC UTRECHT, NETHERLANDS. RI Crutzen, Paul/F-6044-2012; Lelieveld, Johannes/A-1986-2013 NR 120 TC 638 Z9 677 U1 23 U2 144 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 2169-897X J9 J GEOPHYS RES-ATMOS JI J. Geophys. Res.-Atmos. PD OCT 20 PY 1996 VL 101 IS D17 BP 22869 EP 22889 DI 10.1029/96JD01818 PG 21 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA VN184 UT WOS:A1996VN18400012 ER PT J AU Hasan, MK Kouvel, JS Radousky, HB Goodwin, TJ Shelton, RN AF Hasan, MK Kouvel, JS Radousky, HB Goodwin, TJ Shelton, RN TI Vortex pinning in polycrystalline Eu1.5Ce0.5Sr2Cu2NbO10 from rotational magnetic measurements SO PHYSICA C LA English DT Article ID II SUPERCONDUCTOR; CUPRATE; MODEL; ND; SM AB Rotational magnetization-vector measurements were carried out on a superconducting polycrystalline disk of EuCSCNO. The results at 4.2 K and low fields resemble recent results for YBa2Cu3O7-delta (YBCO) and Ba0.57K0.43BiO3 (BKBO) in revealing a broad distribution in the strength of the vortex pinning torques. This resemblance extends to higher fields, where it was found that the average pinning torque per vortex (tau(P)), which is directly related to the critical current density, decreases steadily with increasing field in a manner consistent with vortex bundling. Quantitatively, however, the values of tau(P) for EuCSCNO are smaller by an order of magnitude than those for YBCO but are only moderately smaller than those for BKBO. This comparison supports the notion that the vortex pinning may derive in part from deviations from oxygen stoichiometry, which are normally present in YBCO but are essentially absent in EuCSCNO and BKBO. Moreover, as in YBCO and BKBO, the tau(P) in EuCSCNO at fixed field is found to diminish rapidly as the temperature rises towards T-c. C1 LAWRENCE LIVERMORE NATL LAB,LIVERMORE,CA 94550. UNIV CALIF DAVIS,DEPT PHYS,DAVIS,CA 95616. RP Hasan, MK (reprint author), UNIV ILLINOIS,DEPT PHYS,CHICAGO,IL 60607, USA. NR 14 TC 7 Z9 7 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 OCT 20 PY 1996 VL 270 IS 3-4 BP 216 EP 222 DI 10.1016/S0921-4534(96)00508-4 PG 7 WC Physics, Applied SC Physics GA VR460 UT WOS:A1996VR46000003 ER PT J AU Tobiason, JD Rohlfing, EA AF Tobiason, JD Rohlfing, EA TI Lifetimes of vibrational levels in the (B)over-tilde(2)A' state of HCO - Reply SO CHEMICAL PHYSICS LETTERS LA English DT Article AB The preceding Comment by Bitto and Carter objects to our interpretation of the weak quantum beats observed for particular rovibrational states of (B) over tilde (2)A' HCO in the title article and postulates that the observed beats are anisotropic hyperfine quantum beats. We concur with their Comment, acknowledge the conceptual errors in our initial interpretation, and provide additional evidence in support of their new interpretation. The other results and conclusions of the title article remain unchanged. RP Tobiason, JD (reprint author), SANDIA NATL LABS,COMBUST RES FACIL,LIVERMORE,CA 94551, USA. NR 2 TC 0 Z9 0 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 OCT 18 PY 1996 VL 261 IS 3 BP 387 EP 388 DI 10.1016/0009-2614(96)00964-5 PG 2 WC Chemistry, Physical; Physics, Atomic, Molecular & Chemical SC Chemistry; Physics GA VN637 UT WOS:A1996VN63700028 ER PT J AU Thomas, CP Doggett, NA Fisher, R Stokes, JB AF Thomas, CP Doggett, NA Fisher, R Stokes, JB TI Genomic organization and the 5' flanking region of the gamma subunit of the human amiloride-sensitive epithelial sodium channel SO JOURNAL OF BIOLOGICAL CHEMISTRY LA English DT Article ID NA+ CHANNEL; DNA METHYLATION; HOMOLOGOUS SUBUNITS; MEMBRANE TOPOLOGY; LIDDLES SYNDROME; EXPRESSION; CLONING; GENE; ALDOSTERONE; MUTATIONS AB The amiloride sensitive epithelial sodium channel (ENaC) complex is made up of at least three different subunits alpha, beta, and gamma, which are developmentally regulated, selectively expressed, and variously up-regulated by steroid hormones. To understand mechanisms involved in regulation of the gamma subunit, we have determined the structure of the human gamma ENaC gene. By 5' rapid amplification of cDNA ends, primer extension analysis, and nuclease protection assay, we identified transcription start sites in human brain, kidney, and lung. A human genomic library was screened and overlapping cosmid clones that span similar to 50 kilobases and con tain the h gamma ENaC gene were identified. The 5'-untranslated region is 141 bases long, and the translation start codon is contained within the second exon, The human gene spans at least 35 kilobases. The 5' end of the gene including portions of 5' flanking genomic DNA and the first intron are G + C rich and contain several CPG dinucleotides, consistent with a CpG island. The 5' flanking region contains no CCAAT or TATA-like elements but does contain two GC boxes as well as several putative transcription factor binding sites including AP-2, Sp1, CRE, PEA-3, and NF-IL6. This is the first description of the structural organization and the 5' flanking region of a member of the epithelial sodium channel complex. C1 UNIV IOWA,COLL MED,DEPT INTERNAL MED,IOWA CITY,IA. UNIV IOWA,COLL MED,DEPT PHARMACOL,IOWA CITY,IA. VET AFFAIRS MED CTR,IOWA CITY,IA 52242. LOS ALAMOS NATL LAB,DIV LIFE SCI,LOS ALAMOS,NM. RP Thomas, CP (reprint author), UNIV IOWA HOSP & CLIN,DEPT INTERNAL MED,DIV NEPHROL,200 HAWKINS DR,IOWA CITY,IA 52242, USA. FU NIDDK NIH HHS [DK 25231] NR 39 TC 43 Z9 44 U1 0 U2 0 PU AMER SOC BIOCHEMISTRY MOLECULAR BIOLOGY INC PI BETHESDA PA 9650 ROCKVILLE PIKE, BETHESDA, MD 20814 SN 0021-9258 J9 J BIOL CHEM JI J. Biol. Chem. PD OCT 18 PY 1996 VL 271 IS 42 BP 26062 EP 26066 PG 5 WC Biochemistry & Molecular Biology SC Biochemistry & Molecular Biology GA VN180 UT WOS:A1996VN18000053 PM 8824247 ER PT J AU Nelson, WM Tang, Q Harrata, AK Lee, CS AF Nelson, WM Tang, Q Harrata, AK Lee, CS TI On-line partial filling micellar electrokinetic chromatography electrospray ionization mass spectrometry SO JOURNAL OF CHROMATOGRAPHY A LA English DT Article DE mass spectrometry; partial filling micellar electrokinetic chromatography; herbicides; triazines; atrazine; propazine; ametryne; prometryne ID ELECTROPHORESIS; SURFACTANT; INTERFACE AB On-line combination of partial filling micellar electrokinetic chromatography (PF-MEKC) and electrospray ionization mass spectrometry (ESI-MS) is demonstrated for the analysis of triazine herbicides including atrazine, propazine, ametryne and prometryne. In comparison with conventional micellar electrokinetic chromatography (MEKC), PF-MEKC involves filling a small portion of the capillary with a sodium dodecyl sulfate (SDS) micellar solution for achieving the separation. In PF-MEKC, the triazine analytes first migrate into the micellar plug where the separation occurs and then into the electrophoresis buffer which is free of surfactant. Consequently, the electroosmotic transfer of neutral triazine herbicides to ESI-MS at the end of PF-MEKC capillary is comparable to conventional capillary zone electrophoresis ESI-MS. Therefore, PF-MEKC-ESI-MS provides a mechanism for the separation and mass detection of neutral molecules without the interference of surfactant. C1 IOWA STATE UNIV,DEPT CHEM,AMES,IA 50011. IOWA STATE UNIV,US DOE,AMES LAB,AMES,IA 50011. NR 8 TC 78 Z9 81 U1 3 U2 9 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 OCT 18 PY 1996 VL 749 IS 1-2 BP 219 EP 226 DI 10.1016/0021-9673(96)00455-4 PG 8 WC Biochemical Research Methods; Chemistry, Analytical SC Biochemistry & Molecular Biology; Chemistry GA VR647 UT WOS:A1996VR64700029 ER PT J AU Shen, ZY Peterson, SR Comeaux, JC Zastrow, D Moyzis, RK Bradbury, EM Chen, DJ AF Shen, ZY Peterson, SR Comeaux, JC Zastrow, D Moyzis, RK Bradbury, EM Chen, DJ TI Self-association of human RAD52 protein SO MUTATION RESEARCH-DNA REPAIR LA English DT Article DE RAD52; RAD51; DSB; DNA double-strand breaks; two hybrid system ID SACCHAROMYCES-CEREVISIAE; DNA-REPAIR; MEIOTIC RECOMBINATION; GENES; CLONING; MOUSE; CELLS AB The yeast RAD52 protein is required for both homologous DNA recombination and repair of DNA double-strand breaks. RAD52 can bind to the yeast RAD51 protein, which shares a functional similarity with the bacterial RecA protein. The gene encoding the human homolog of the yeast RAD52 protein shares significant N-terminus amino acid homology with the yeast RAD52 protein. Using a yeast two hybrid system and purified GST-RAD52 fusion protein, we demonstrate that the human RAD52 protein self-associates both in vivo and in vitro. The region of RAD52 required for its self-interaction, mapped here as amino acid residues 65-165, has significant homology with the yeast RAD52 (52% identity, and 89% similarity), suggesting the importance of self-association for RAD52's function. C1 LOS ALAMOS NATL LAB,DIV LIFE SCI,LOS ALAMOS,NM 87545. LOS ALAMOS NATL LAB,CTR HUMAN GENOME STUDIES,LOS ALAMOS,NM 87545. LAWRENCE LIVERMORE NATL LAB,SCH MED,DEPT BIOL CHEM,DAVIS,CA 95616. FU NCI NIH HHS [CA50519] NR 17 TC 30 Z9 30 U1 0 U2 0 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0921-8777 J9 MUTAT RES-DNA REPAIR JI Mutat. Res.-DNA Repair PD OCT 18 PY 1996 VL 364 IS 2 BP 81 EP 89 DI 10.1016/0921-8777(96)00025-0 PG 9 WC Biotechnology & Applied Microbiology; Genetics & Heredity; Toxicology SC Biotechnology & Applied Microbiology; Genetics & Heredity; Toxicology GA VM879 UT WOS:A1996VM87900003 PM 8879274 ER PT J AU Nellist, PD Pennycook, SJ AF Nellist, PD Pennycook, SJ TI Direct imaging of the atomic configuration of ultradispersed catalysts SO SCIENCE LA English DT Article ID TRANSMISSION ELECTRON-MICROSCOPY; RAY ABSORPTION-SPECTROSCOPY; SINGLE AB Direct imaging of individual catalyst metal atoms on the insulating surface of an industrial support is demonstrated, Individual platinum and rhodium atoms ultradispersed on gamma-Al2O3 supports were imaged by high-resolution Z-contrast (atomic number Z) microscopy in a 300-kilovolt scanning transmission electron microscope, Within small clusters, the configuration of the metal atoms was seen to be constrained to match the surface structure of the gamma-Al2O3, from which likely surface adsorption sites were deduced, A thin, extended raft of rhodium atoms was observed, mostly corresponding to one monolayer. Occasional two-atom features suggested partial dissolution into the top layers of the gamma-Al2O3 support. C1 OAK RIDGE NATL LAB,DIV SOLID STATE,OAK RIDGE,TN 37831. NR 17 TC 173 Z9 173 U1 3 U2 43 PU AMER ASSOC ADVANCEMENT SCIENCE PI WASHINGTON PA 1200 NEW YORK AVE, NW, WASHINGTON, DC 20005 SN 0036-8075 J9 SCIENCE JI Science PD OCT 18 PY 1996 VL 274 IS 5286 BP 413 EP 415 DI 10.1126/science.274.5286.413 PG 3 WC Multidisciplinary Sciences SC Science & Technology - Other Topics GA VN173 UT WOS:A1996VN17300051 ER PT J AU Cotton, FA Chen, LF Schultz, AJ AF Cotton, FA Chen, LF Schultz, AJ TI Combined single-crystal X-ray and neutron diffraction analysis of the structure of the [Zr6Cl18H5](3-)polyanion SO COMPTES RENDUS DE L ACADEMIE DES SCIENCES SERIE II FASCICULE B-MECANIQUE PHYSIQUE CHIMIE ASTRONOMIE LA English DT Article ID CLUSTERS; ZIRCONIUM AB The octahedral hexazirconium compound (Ph(4)P)(3)[Zr6Cl18H5] has been structurally characterized by a combined analysis of single-crystal X-ray and time-of-flight (TOF) neutron diffraction data. The space group is tetragonal, I4(1)/a, Z = 8, with lattice constants at 123 K of a = 32.957(8), c = 15.001(3) Angstrom, V = 16,294(6) Angstrom(3). Difference Fourier maps based on the neutron data exhibited negative troughs on the triangular faces of the hexazirconium octahedron which were introduced into the structure as hydrogen atoms. Refinement of the atomic positional and occupancy parameters for the hydrogen atoms resulted in about 0.7 H atoms on each triangular face for a total of 5.47(15) hydrogen atoms per hexazirconium cluster, in good accord with the H-1 NMR measurement (5.0) and the theoretical expectation of 5. The Zr - (mu(3)H) distances range from 1.8 to 2.1 Angstrom. C1 TEXAS A&M UNIV,MOL STRUCT & BONDING LAB,COLLEGE STN,TX 77843. ARGONNE NATL LAB,INTENSE PULSED NEUTRON SOURCE,ARGONNE,IL 60439. RP Cotton, FA (reprint author), TEXAS A&M UNIV,DEPT CHEM,COLLEGE STN,TX 77843, USA. NR 13 TC 5 Z9 5 U1 0 U2 0 PU GAUTHIER-VILLARS PI PARIS PA S P E S-JOURNAL DEPT, 120 BD ST GERMAIN, F-75006 PARIS, FRANCE SN 1251-8069 J9 CR ACAD SCI II B JI Comptes Rendus Acad. Sci. Ser. II-B PD OCT 17 PY 1996 VL 323 IS 8 BP 539 EP 544 PG 6 WC Multidisciplinary Sciences SC Science & Technology - Other Topics GA VP483 UT WOS:A1996VP48300005 ER PT J AU McCarthy, MI Schenter, GK Scamehorn, CA Nicholas, JB AF McCarthy, MI Schenter, GK Scamehorn, CA Nicholas, JB TI Structure and dynamics of the water/MgO interface SO JOURNAL OF PHYSICAL CHEMISTRY LA English DT Article ID ACID-BASE PROPERTIES; MAGNESIUM-OXIDE; MGO SURFACES; HARTREE-FOCK; ADSORPTION; MGO(100); CRYSTAL; ENERGY; HYDROXYLATION; POWDERS AB A pairwise additive potential energy expression for the water/MgO interaction was obtained by fitting the parameters to ab initio electronic structure energy data, computed using correlation-corrected periodic Hartree-Fock (PHF) theory, at selected adsorbate/surface geometries. This potential energy expression was used in molecular dynamics and Monte Carlo simulations to elucidate the water/MgO interaction. Energy minimization reveals a nearly planar adsorbate/surface equilibrium geometry (-15 degrees from the surface plane with the hydro(e)ns pointing toward the surface oxygens) for an isolated water on perfect MgO (001), with a binding energy of 17.5 kcal/mol; subsequent PHF calculations on this system confirmed that this is a potential minimum. Rate constants for desorption (k(dsorb)), intersite hopping (k(hop)), intrasite rotation (k(rot)), and intrasite flipping (k(flip)) were estimated for an isolated water on the surface using simple transition state theory. The computed rates (at T = 300 K) are k(dsorb) = 1.1 x 10(5) s(-1), k(hop) = 3.7 x 10(10) s(-1), k(rot) = 5.7 x 10(11) s(-1), and k(flip) = 4.6 x 10(11) s(-1). The motion of a single water on the surface is described by an effective diffusion constant (D-eff = 8.0 x 10(-6) cm(2)/s), computed from the surface rate constants combined with Monte Carlo simulations. The structure of the liquid water/MgO interface was determined from simulations with 64 and 128 water molecules on the surface. Simulations (at T = 300 K) of the two-dimensional water overlayers reveal a densely packed first layer, Z(O-w-surf) = 2-3 Angstrom, with one water per surface magnesium, with a nearly equal distribution of water molecules aligned -17 degrees and +30 degrees with respect to the surface plane. A more diffuse second layer exists, Z(O-w-surf) = 4-5.5 Angstrom, with a much broader distribution of water angular orientations with respect to the surface plane. The region Z(O-w-surf) > 6 Angstrom resembles bulk water, with the density profile approaching a constant as a function of distance above the surface and a uniform distribution in water/surface angular orientations. At the water/vacuum interface (top of the multilayer) the waters assume a ''planar orientation'' (o degrees(-) with respect to the surface plane). During the timescale of these simulations very little interlayer exchange of water molecules occurs between the first monolayer (n = 1) and the additional overlayers (n greater than or equal to 2). In contrast, the water molecules in the multilayers (n greater than or equal to 2) display motion similar to bulk liquid water at this temperature. RP McCarthy, MI (reprint author), PACIFIC NW NATL LAB,ENVRIONM MOL SCI LAB,MS K1-96,POB 999,RICHLAND,WA 99352, USA. RI Schenter, Gregory/I-7655-2014 OI Schenter, Gregory/0000-0001-5444-5484 NR 48 TC 93 Z9 94 U1 1 U2 16 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 SN 0022-3654 J9 J PHYS CHEM-US JI J. Phys. Chem. PD OCT 17 PY 1996 VL 100 IS 42 BP 16989 EP 16995 DI 10.1021/jp961373i PG 7 WC Chemistry, Physical SC Chemistry GA VN802 UT WOS:A1996VN80200031 ER PT J AU Bechinger, C Ferrer, S Zaban, A Sprague, J Gregg, BA AF Bechinger, C Ferrer, S Zaban, A Sprague, J Gregg, BA TI Photoelectrochromic windows and displays SO NATURE LA English DT Article ID TIO2 ELECTRODES; THIN-FILM; LIGHT AB PHOTOCHROMIC materials(1,2) change colour on absorption of light, whereas electrochromic materials(3,4) change colour in response to an electrically induced change in oxidation state. Both classes of materials are being investigated for potential applications in displays, imaging devices and 'smart' windows(5-8,15,16). Here we describe an alternative route to such applications, in which an electrochromic film and a photovoltaic film form the two electrodes of an electrochemical cell. The resulting structure exhibits photochromism, but unlike conventional photochromic films, the light-absorption process (in the photovoltaic film) is separate from the coloration process (in the electrochromic film): both may therefore he optimized individually. Moreover, as the coloration process in our cells requires an external electrical current between the two electrodes, the optical state of the cell-transparent, absorbing or, in the case of non-uniform illumination, patterned-can be stored when the circuit is open, or changed when the electrodes are connected. C1 NATL RENEWABLE ENERGY LAB,GOLDEN,CO 80401. UNIV KONSTANZ,D-78434 CONSTANCE,GERMANY. NR 16 TC 371 Z9 379 U1 16 U2 138 PU MACMILLAN MAGAZINES LTD PI LONDON PA 4 LITTLE ESSEX STREET, LONDON, ENGLAND WC2R 3LF SN 0028-0836 J9 NATURE JI Nature PD OCT 17 PY 1996 VL 383 IS 6601 BP 608 EP 610 DI 10.1038/383608a0 PG 3 WC Multidisciplinary Sciences SC Science & Technology - Other Topics GA VM755 UT WOS:A1996VM75500048 ER PT J AU Fleischer, R Dunietz, I AF Fleischer, R Dunietz, I TI CP violation and the CKM angle gamma from angular distributions of untagged B-s decays governed by (b)over-bar->(c)over-bar-u(s)over-bar SO PHYSICS LETTERS B LA English DT Article ID KOBAYASHI-MASKAWA MATRIX; PHASE-GAMMA; MESON DECAY; WEAK DECAYS; PARAMETRIZATION; REGULARIZATION; ASYMMETRIES; SYSTEM; MODEL; MASS AB We demonstrate that time-dependent studies of angular distributions for B-s decays caused by (b) over bar --> (c) over bar quark-level transitions extract cleanly and model-independently the CKM angle gamma. This CKM angle could be cleanly determined from untagged B-s decays alone, if the lifetime difference between the B-s mass eigenstates B-s(L) and B-s(H) is sizable. The time dependences for the relevant tagged and untagged observables are given both in a general notation and in terms of linear polarization states and should exhibit large CP-violating effects. These observables may furthermore provide insights into the hadronization dynamics of the corresponding exclusive B-s decays, thereby allowing tests of the factorization hypothesis. C1 FERMILAB NATL ACCELERATOR LAB,DIV THEORET PHYS,BATAVIA,IL 60510. RP Fleischer, R (reprint author), UNIV KARLSRUHE,INST THEORET TEILCHENPHYS,KAISERSTR 12,D-76128 KARLSRUHE,GERMANY. NR 46 TC 37 Z9 37 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 OCT 17 PY 1996 VL 387 IS 2 BP 361 EP 370 DI 10.1016/0370-2693(96)01033-7 PG 10 WC Astronomy & Astrophysics; Physics, Nuclear; Physics, Particles & Fields SC Astronomy & Astrophysics; Physics GA VN247 UT WOS:A1996VN24700023 ER PT J AU Zhu, ZL Espenson, JH AF Zhu, ZL Espenson, JH TI Organic reactions catalyzed by methylrhenium trioxide: Reactions of ethyl diazoacetate and organic azides SO JOURNAL OF THE AMERICAN CHEMICAL SOCIETY LA English DT Article ID MAIN-GROUP ELEMENTS; TRANSITION-METALS; MULTIPLE BONDS; HYDROGEN-PEROXIDE; EFFICIENT SYNTHESIS; OXYGEN-TRANSFER; DIAZO-COMPOUNDS; METHYLTRIOXORHENIUM; OXIDATION; OXIDES AB Methylrhenium trioxide (CH3ReO3 or MTO) catalyzes several classes of reactions of ethyl diazoacetate, EDA. It is the first high valent oxo complex for carbene transfer. Under mild conditions and in the absence of other substrates, EDA was converted to a 9:1 mixture of diethyl maleate and diethyl fumarate. In the presence of alcohols, alpha-alkoxy ethyl acetates were obtained in good yield. The yields dropped for the larger and more branched alcohols, the balance of material being diethyl maleate and fumarate. An electron-donating group in the para position of phenols favors the formation of a-phenoxy ethyl acetates. The use of EDA to form alpha-thio ethyl acetates and N-substituted glycine ethyl esters, on the other hand, is hardly affected by the size or structure of the parent thiol or amine, with all of these reactions proceeding in high yield. MTO-catalyzed cycloaddition reactions occur between EDA and aromatic imines, olefins, and carbonyl compounds. Three-membered ring products are formed: aziridines, cyclopropanes, and epoxides, respectively. The reactions favor the formation of trans products, and provide a convenient route for the preparation of aziridines. Intermediate carbenoid and nitrenoid species have been proposed. In the presence of an oxygen source such as an epoxide, ethyl diazoacetate and azibenzil are converted to an oxalic acid monoethyl ester and to benzil; at the same time the epoxide was converted to an olefin. These results provide further support for the proposed intermediate, a cyclic species containing Re, O, and CHCO(2)Et (or, occasionally, CPhC(O)Ph) in a three-membered ring. C1 IOWA STATE UNIV,AMES LAB,AMES,IA 50011. IOWA STATE UNIV,DEPT CHEM,AMES,IA 50011. NR 75 TC 87 Z9 88 U1 1 U2 19 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 SN 0002-7863 J9 J AM CHEM SOC JI J. Am. Chem. Soc. PD OCT 16 PY 1996 VL 118 IS 41 BP 9901 EP 9907 DI 10.1021/ja954039t PG 7 WC Chemistry, Multidisciplinary SC Chemistry GA VM937 UT WOS:A1996VM93700012 ER PT J AU Geiser, U Schlueter, JA Wang, HH Kini, AM Williams, JM Sche, PP Zakowicz, HI VanZile, ML Dudek, JD Nixon, PG Winter, RW Gard, GL Ren, J Whangbo, MH AF Geiser, U Schlueter, JA Wang, HH Kini, AM Williams, JM Sche, PP Zakowicz, HI VanZile, ML Dudek, JD Nixon, PG Winter, RW Gard, GL Ren, J Whangbo, MH TI Superconductivity at 5.2 K in an electron donor radical salt of bis(ethylenedithio)tetrathiafulvalene (BEDT-TTF) with the novel polyfluorinated organic anion SF5CH2CF2SO3 (-) SO JOURNAL OF THE AMERICAN CHEMICAL SOCIETY LA English DT Article ID SPIN-RESONANCE; (BEDT-TTF)2I3; PHASES C1 ARGONNE NATL LAB,DIV MAT SCI,ARGONNE,IL 60439. PORTLAND STATE UNIV,DEPT CHEM,PORTLAND,OR 97207. N CAROLINA STATE UNIV,DEPT CHEM,RALEIGH,NC 27695. RP Geiser, U (reprint author), ARGONNE NATL LAB,DIV CHEM,9700 S CASS AVE,ARGONNE,IL 60439, USA. RI Kini, Aravinda/F-4467-2012 NR 17 TC 126 Z9 128 U1 1 U2 8 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 SN 0002-7863 J9 J AM CHEM SOC JI J. Am. Chem. Soc. PD OCT 16 PY 1996 VL 118 IS 41 BP 9996 EP 9997 DI 10.1021/ja962188l PG 2 WC Chemistry, Multidisciplinary SC Chemistry GA VM937 UT WOS:A1996VM93700030 ER PT J AU Fryxell, GE Rieke, PC Wood, LL Engelhard, MH Williford, RE Graff, GL Campbell, AA Wiacek, RJ Lee, L Halverson, A AF Fryxell, GE Rieke, PC Wood, LL Engelhard, MH Williford, RE Graff, GL Campbell, AA Wiacek, RJ Lee, L Halverson, A TI Nucleophilic displacements in mixed self-assembled monolayers SO LANGMUIR LA English DT Article ID SCANNING ELECTRON-MICROSCOPY; LANGMUIR-BLODGETT; ALKANETHIOL MONOLAYERS; INFRARED-SPECTROSCOPY; GOLD; FILMS; DEPOSITION; REACTIVITY; SURFACES; SILICA AB Synthetic elaboration of self-assembled monolayers (SAMs) provides a powerful method for the preparation of smooth, ordered surfaces with carefully controlled functionality. Chemically rugged siloxane-based SAMs have been employed as a foundation for the preparation of a variety of functionalized surfaces. Nucleophilic displacements are described between halide-terminated SAMs and anionic nucleophiles (e.g. azide, thiocyanate, thiolate). Problems were encountered due to the steric congestion surrounding the terminal bromomethylene carbon. The concept of trajectory control is applied to these displacement reactions. In addition, reactions between ester-terminated SAMs and neutral nucleophiles (e.g. amines, hydrazine, hydroxylamine) are described. Evidence is presented suggesting that a modest amount of cross-linking (i.e. imide formation) takes place in the amidation reactions, while reaction stoichiometry indicates that cross-linking is virtually complete for the bifunctional nucleophiles. These synthetic elaborations were also carried out on mixed monolayers to create functionalized SAMs with systematically varied loading densities. Linear correlation (or lack thereof) of elemental composition to predicted functional composition is used to provide an estimation of reaction efficiency. RP Fryxell, GE (reprint author), PACIFIC NW LAB, DEPT MAT SCI, POB 999, RICHLAND, WA 99352 USA. RI Engelhard, Mark/F-1317-2010; OI Engelhard, Mark/0000-0002-5543-0812 NR 65 TC 120 Z9 121 U1 0 U2 20 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 SN 0743-7463 J9 LANGMUIR JI Langmuir PD OCT 16 PY 1996 VL 12 IS 21 BP 5064 EP 5075 DI 10.1021/la9506842 PG 12 WC Chemistry, Multidisciplinary; Chemistry, Physical; Materials Science, Multidisciplinary SC Chemistry; Materials Science GA VN325 UT WOS:A1996VN32500013 ER PT J AU Henderson, MA AF Henderson, MA TI Structural sensitivity in the dissociation of water on TiO2 single-crystal surfaces SO LANGMUIR LA English DT Article ID HYDROXYLATED OXIDE SURFACES; TIO2(110) SURFACES; INFRA-RED; RUTILE SURFACES; ADSORPTION; H2O; TITANIUM; OXYGEN; DESORPTION; REACTIVITY AB Temperature-programmed desorption (TPD) and oxygen isotopic labeling studies were used to probe the dissociation of water on the (100) and (110) surfaces of TiO2 (rutile). Water TPD spectra from these two surfaces were distinctive. Three monolayer desorption states were observed for the (100) surface (at 205, 250, and 305 K), while only a single desorption state was observed for the (110) surface (at 270 K). TPD experiments on the surfaces enriched with O-18 revealed that water desorbing in the 305 K state from TiO2(100) was isotopically scrambled with the lattice oxygen atoms, strongly suggesting that this TPD state resulted from recombination of surface hydroxyl groups. Isotopic scrambling was not observed for any other desorption state on either surface (in the absence of defects). Since very little water desorption occurred from the (110) surface in the temperature range in which exchange was observed on the (100) surface and since previous HREELS work (Henderson, M. A. Surf: Sci. 1996, 355, 151) indicated that very little water dissociation was detected for the (110) surface, the ideal TiO2(110) surface appears to be inactive for water dissociation under ultrahigh vacuum (UHV) conditions. Comparison of the geometric arrangement of acidic and basic sites on these two surfaces suggests that the bridging two-coordinate O2- sites (basic sites) on TiO2(110) are too distant from the binding sites of water (five-coordinate Ti4+ sites) to form hydrogen-bonding interactions with water that might facilitate O-H bond dissociation, whereas the proximity of these sites on the TiO2(100) surface should favor such a concerted interaction. The TiO2(110) surface was active for dissociation of water when structural defects such as steps or kinks were present. Defects created by annealing or by electron-beam irradiation were less active for water dissociation. RP Henderson, MA (reprint author), PACIFIC NW LAB,MAT & INTERFACES GRP, ENVIRONM MOL SCI LAB,POB 999, MS K2-12, RICHLAND, WA 99352 USA. NR 44 TC 322 Z9 326 U1 10 U2 117 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 SN 0743-7463 J9 LANGMUIR JI Langmuir PD OCT 16 PY 1996 VL 12 IS 21 BP 5093 EP 5098 DI 10.1021/la960360t PG 6 WC Chemistry, Multidisciplinary; Chemistry, Physical; Materials Science, Multidisciplinary SC Chemistry; Materials Science GA VN325 UT WOS:A1996VN32500017 ER PT J AU Korobka, A Cullinan, D Cosman, M Grollman, AP Patel, DJ Eisenberg, M delosSantos, C AF Korobka, A Cullinan, D Cosman, M Grollman, AP Patel, DJ Eisenberg, M delosSantos, C TI Solution structure of an oligodeoxynucleotide duplex containing the exocyclic lesion 3,N-4-etheno-2'-deoxycytidine opposite 2'-deoxyadenosine, determined by NMR spectroscopy and restrained molecular dynamics SO BIOCHEMISTRY LA English DT Article ID SITE-SPECIFIC ETHENOCYTOSINE; NUCLEAR MAGNETIC-RESONANCE; VINYL-CHLORIDE; DNA DUPLEXES; ADDUCTS; ACIDS; MUTAGENESIS; PH; DEOXYADENOSINE; REFINEMENT AB The d(C-G-T-A-C-epsilon C-C-A-T-G-C). d(G-C-A-T-G-A-G-T-A-C-G) oligodeoxynucleotide duplex containing the 3,N-4-etheno-2'-deoxycytidine adduct positioned opposite 2'-deoxyadenosine in the center of the helix has been analyzed by proton NMR spectroscopy and restrained molecular dynamics, The spectroscopic data establish a right-handed duplex, with sugar puckers in the C2'-endo/C3'-exo range, residues adopting an anti conformation around the glycosidic torsion angle and, with the exception of epsilon C . dA, Watson-Crick hydrogen bond alignment for all base pairs. Molecular dynamics simulations, restrained by the full relaxation matrix approach, produced a three-dimensional model with an NMR R-factor of 7%. The duplex structure shows no significant perturbation of the sugar-phosphate backbone, which remains in B-form. The exocyclic adduct and its partner dA are incorporated into the helix without producing a noticeable kink. The epsilon C . dA alignment adopts a staggered conformation with each residue displaced toward the 5'-terminus and intercalated between bases on the opposite strand, without increase of inter-phosphate distances. The partial intercalation of the epsilon C(anti). dA(anti) alignment allows stacking between the aromatic rings of epsilon C and dA and with base pairs adjacent to the lesion, suggesting an important role played by hydrophobic forces in the stabilization of the solution structure. C1 SUNY STONY BROOK,DEPT PHARMACOL SCI,STONY BROOK,NY 11794. LAWRENCE LIVERMORE NATL LAB,BIOL & BIOTECHNOL RES PROGRAM,LIVERMORE,CA 94550. MEM SLOAN KETTERING CANC CTR,NEW YORK,NY 10021. FU NCI NIH HHS [CA47995] NR 37 TC 21 Z9 21 U1 0 U2 3 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 SN 0006-2960 J9 BIOCHEMISTRY-US JI Biochemistry PD OCT 15 PY 1996 VL 35 IS 41 BP 13310 EP 13318 DI 10.1021/bi9605696 PG 9 WC Biochemistry & Molecular Biology SC Biochemistry & Molecular Biology GA VM555 UT WOS:A1996VM55500008 PM 8873597 ER PT J AU Hughes, SD Ighani, S Verstuyft, J Rubin, EM AF Hughes, SD Ighani, S Verstuyft, J Rubin, EM TI Lipoprotein(a) vascular binding: In vivo analysis of the role of lysine binding sites using adenovirus mediated gene transfer SO CIRCULATION LA English DT Meeting Abstract C1 LAWRENCE BERKELEY LAB,BERKELEY,CA. NR 0 TC 1 Z9 1 U1 0 U2 0 PU AMER HEART ASSOC PI DALLAS PA 7272 GREENVILLE AVENUE, DALLAS, TX 75231-4596 SN 0009-7322 J9 CIRCULATION JI Circulation PD OCT 15 PY 1996 VL 94 IS 8 SU S BP 211 EP 211 PG 1 WC Cardiac & Cardiovascular Systems; Peripheral Vascular Disease SC Cardiovascular System & Cardiology GA VN119 UT WOS:A1996VN11900210 ER PT J AU Boonmark, NW Schwartz, K Lou, XJ Pearle, AD Rubin, EM Lawn, RM AF Boonmark, NW Schwartz, K Lou, XJ Pearle, AD Rubin, EM Lawn, RM TI The role of apo(a) lysine binding site in atherosclerosis SO CIRCULATION LA English DT Meeting Abstract C1 STANFORD UNIV,SCH MED,STANFORD,CA 94305. LAWRENCE BERKELEY LAB,BERKELEY,CA. NR 0 TC 0 Z9 0 U1 0 U2 1 PU AMER HEART ASSOC PI DALLAS PA 7272 GREENVILLE AVENUE, DALLAS, TX 75231-4596 SN 0009-7322 J9 CIRCULATION JI Circulation PD OCT 15 PY 1996 VL 94 IS 8 SU S BP 212 EP 212 PG 1 WC Cardiac & Cardiovascular Systems; Peripheral Vascular Disease SC Cardiovascular System & Cardiology GA VN119 UT WOS:A1996VN11900211 ER PT J AU Dreon, DM Fernstrom, HA Williams, PT Krauss, RM AF Dreon, DM Fernstrom, HA Williams, PT Krauss, RM TI A very low fat diet is not associated with improved lipoprotein profiles in men with a predominance of large low density lipoproteins SO CIRCULATION LA English DT Meeting Abstract C1 LAWRENCE BERKELEY LAB,BERKELEY,CA. CHILDRENS HOSP,OAKLAND RES INST,OAKLAND,CA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU AMER HEART ASSOC PI DALLAS PA 7272 GREENVILLE AVENUE, DALLAS, TX 75231-4596 SN 0009-7322 J9 CIRCULATION JI Circulation PD OCT 15 PY 1996 VL 94 IS 8 SU S BP 552 EP 552 PG 1 WC Cardiac & Cardiovascular Systems; Peripheral Vascular Disease SC Cardiovascular System & Cardiology GA VN119 UT WOS:A1996VN11900551 ER PT J AU Dreon, DM Fernstrom, HA Williams, PT Krausse, RM AF Dreon, DM Fernstrom, HA Williams, PT Krausse, RM TI Prevalence of small, dense LDL phenotype in children on a very low-fat diet is related to parental LDL subclass phenotypes SO CIRCULATION LA English DT Meeting Abstract C1 LAWRENCE BERKELEY NATL LAB,BERKELEY,CA. CHILDRENS HOSP,OAKLAND RES INST,OAKLAND,CA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU AMER HEART ASSOC PI DALLAS PA 7272 GREENVILLE AVENUE, DALLAS, TX 75231-4596 SN 0009-7322 J9 CIRCULATION JI Circulation PD OCT 15 PY 1996 VL 94 IS 8 SU S BP 553 EP 553 PG 1 WC Cardiac & Cardiovascular Systems; Peripheral Vascular Disease SC Cardiovascular System & Cardiology GA VN119 UT WOS:A1996VN11900552 ER PT J AU Reddy, KB Gascard, P Price, MG Fox, JE AF Reddy, KB Gascard, P Price, MG Fox, JE TI Identification and characterization of a specific interaction between skelemin and beta integrin cytoplasmic tails SO CIRCULATION LA English DT Meeting Abstract C1 CLEVELAND CLIN RES INST,CLEVELAND,OH. RICE UNIV,HOUSTON,TX 77251. LAWRENCE BERKELEY LAB,BERKELEY,CA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU AMER HEART ASSOC PI DALLAS PA 7272 GREENVILLE AVENUE, DALLAS, TX 75231-4596 SN 0009-7322 J9 CIRCULATION JI Circulation PD OCT 15 PY 1996 VL 94 IS 8 SU S BP 562 EP 562 PG 1 WC Cardiac & Cardiovascular Systems; Peripheral Vascular Disease SC Cardiovascular System & Cardiology GA VN119 UT WOS:A1996VN11900561 ER PT J AU Recinos, A Ordovas, JM Dreon, DM Miller, BD Logan, SL Krauss, RM AF Recinos, A Ordovas, JM Dreon, DM Miller, BD Logan, SL Krauss, RM TI Association of the apolipoprotein (apo) A-IV codon 360 mutation with plasma lipoprotein subclass levels on high and low fat diets in healthy men. SO CIRCULATION LA English DT Meeting Abstract C1 TUFTS UNIV,USDA,BOSTON,MA 02111. UNIV CALIF BERKELEY,LBNL,BERKELEY,CA 94720. NR 0 TC 0 Z9 0 U1 0 U2 0 PU AMER HEART ASSOC PI DALLAS PA 7272 GREENVILLE AVENUE, DALLAS, TX 75231-4596 SN 0009-7322 J9 CIRCULATION JI Circulation PD OCT 15 PY 1996 VL 94 IS 8 SU S BP 604 EP 604 PG 1 WC Cardiac & Cardiovascular Systems; Peripheral Vascular Disease SC Cardiovascular System & Cardiology GA VN119 UT WOS:A1996VN11900603 ER PT J AU Williams, PT AF Williams, PT TI Interactive effects of diet and exercise level on coronary heart disease risk factors in 10,068 runners. SO CIRCULATION LA English DT Meeting Abstract C1 LAWRENCE BERKELEY LAB,BERKELEY,CA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU AMER HEART ASSOC PI DALLAS PA 7272 GREENVILLE AVENUE, DALLAS, TX 75231-4596 SN 0009-7322 J9 CIRCULATION JI Circulation PD OCT 15 PY 1996 VL 94 IS 8 SU S BP 705 EP 705 PG 1 WC Cardiac & Cardiovascular Systems; Peripheral Vascular Disease SC Cardiovascular System & Cardiology GA VN119 UT WOS:A1996VN11900703 ER PT J AU Williams, PT Moussa, DK AF Williams, PT Moussa, DK TI Relationship of running to coronary heart disease risk factors in sexagenarians and septuagenarians SO CIRCULATION LA English DT Meeting Abstract C1 LAWRENCE BERKELEY LAB,BERKELEY,CA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU AMER HEART ASSOC PI DALLAS PA 7272 GREENVILLE AVENUE, DALLAS, TX 75231-4596 SN 0009-7322 J9 CIRCULATION JI Circulation PD OCT 15 PY 1996 VL 94 IS 8 SU S BP 835 EP 835 PG 1 WC Cardiac & Cardiovascular Systems; Peripheral Vascular Disease SC Cardiovascular System & Cardiology GA VN119 UT WOS:A1996VN11900833 ER PT J AU Amols, HI Mirzadeh, S Knapp, FF Weinberger, J AF Amols, HI Mirzadeh, S Knapp, FF Weinberger, J TI Beta irradiation for restenosis: Considerations for stent implantation SO CIRCULATION LA English DT Meeting Abstract C1 COLUMBIA UNIV,NEW YORK,NY. OAK RIDGE NATL LAB,OAK RIDGE,TN. NR 0 TC 0 Z9 0 U1 0 U2 0 PU AMER HEART ASSOC PI DALLAS PA 7272 GREENVILLE AVENUE, DALLAS, TX 75231-4596 SN 0009-7322 J9 CIRCULATION JI Circulation PD OCT 15 PY 1996 VL 94 IS 8 SU S BP 1220 EP 1220 PG 1 WC Cardiac & Cardiovascular Systems; Peripheral Vascular Disease SC Cardiovascular System & Cardiology GA VN119 UT WOS:A1996VN11901217 ER PT J AU Williams, PT AF Williams, PT TI Benefits of vigorous activity on coronary heart disease risk factors depend on both intensity and amount SO CIRCULATION LA English DT Meeting Abstract C1 LAWRENCE BERKELEY LAB,BERKELEY,CA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU AMER HEART ASSOC PI DALLAS PA 7272 GREENVILLE AVENUE, DALLAS, TX 75231-4596 SN 0009-7322 J9 CIRCULATION JI Circulation PD OCT 15 PY 1996 VL 94 IS 8 SU S BP 1898 EP 1898 PG 1 WC Cardiac & Cardiovascular Systems; Peripheral Vascular Disease SC Cardiovascular System & Cardiology GA VN119 UT WOS:A1996VN11901893 ER PT J AU Bielicki, JK McCall, MR Biller, JA Forte, TM AF Bielicki, JK McCall, MR Biller, JA Forte, TM TI Recruitment of cholesterol from THP-1 macrophage-like foam cells: Assembly of discrete nascent-HDL subpopulations by ApoA-I and endogenously produced ApoE SO CIRCULATION LA English DT Meeting Abstract C1 LAWRENCE BERKELEY LAB,BERKELEY,CA. NR 0 TC 0 Z9 0 U1 0 U2 1 PU AMER HEART ASSOC PI DALLAS PA 7272 GREENVILLE AVENUE, DALLAS, TX 75231-4596 SN 0009-7322 J9 CIRCULATION JI Circulation PD OCT 15 PY 1996 VL 94 IS 8 SU S BP 3038 EP 3038 PG 1 WC Cardiac & Cardiovascular Systems; Peripheral Vascular Disease SC Cardiovascular System & Cardiology GA VN119 UT WOS:A1996VN11903030 ER PT J AU Morrison, JR Hughes, SD Scott, J Rubin, EM AF Morrison, JR Hughes, SD Scott, J Rubin, EM TI A study of molecular events effected by the absence of Apobec-1 SO CIRCULATION LA English DT Meeting Abstract C1 LAWRENCE BERKELEY LAB,BERKELEY,CA. MRC,LONDON,ENGLAND. NR 0 TC 0 Z9 0 U1 0 U2 0 PU AMER HEART ASSOC PI DALLAS PA 7272 GREENVILLE AVENUE, DALLAS, TX 75231-4596 SN 0009-7322 J9 CIRCULATION JI Circulation PD OCT 15 PY 1996 VL 94 IS 8 SU S BP 3684 EP 3684 PG 1 WC Cardiac & Cardiovascular Systems; Peripheral Vascular Disease SC Cardiovascular System & Cardiology GA VN119 UT WOS:A1996VN11903675 ER PT J AU Hughes, SD Verstuyft, J Ighani, S Rubin, EM AF Hughes, SD Verstuyft, J Ighani, S Rubin, EM TI Lack of apolipoprotein A-I in human apolipoprotein B transgenic mice results in greater susceptibility to diet induced atherosclerosis SO CIRCULATION LA English DT Meeting Abstract C1 LAWRENCE BERKELEY LAB,BERKELEY,CA. NR 0 TC 1 Z9 1 U1 0 U2 0 PU AMER HEART ASSOC PI DALLAS PA 7272 GREENVILLE AVENUE, DALLAS, TX 75231-4596 SN 0009-7322 J9 CIRCULATION JI Circulation PD OCT 15 PY 1996 VL 94 IS 8 SU S BP 3695 EP 3695 PG 1 WC Cardiac & Cardiovascular Systems; Peripheral Vascular Disease SC Cardiovascular System & Cardiology GA VN119 UT WOS:A1996VN11903686 ER PT J AU Lawn, RM Pearle, AD Reckless, J Rubin, EM Metcalfe, JC Grainger, DJ AF Lawn, RM Pearle, AD Reckless, J Rubin, EM Metcalfe, JC Grainger, DJ TI Feedback mechanism of focal vascular lesion formation in transgenic apolipoprotein(a) mice SO CIRCULATION LA English DT Meeting Abstract C1 STANFORD UNIV,SCH MED,STANFORD,CA 94305. LAWRENCE BERKELEY LAB,BERKELEY,CA. UNIV CAMBRIDGE,CAMBRIDGE CB2 1TN,ENGLAND. NR 0 TC 0 Z9 0 U1 0 U2 2 PU AMER HEART ASSOC PI DALLAS PA 7272 GREENVILLE AVENUE, DALLAS, TX 75231-4596 SN 0009-7322 J9 CIRCULATION JI Circulation PD OCT 15 PY 1996 VL 94 IS 8 SU S BP 3701 EP 3701 PG 1 WC Cardiac & Cardiovascular Systems; Peripheral Vascular Disease SC Cardiovascular System & Cardiology GA VN119 UT WOS:A1996VN11903692 ER PT J AU Kovscek, AR Radke, CJ AF Kovscek, AR Radke, CJ TI Gas bubble snap-off under pressure-driven flow in constricted noncircular capillaries SO COLLOIDS AND SURFACES A-PHYSICOCHEMICAL AND ENGINEERING ASPECTS LA English DT Article DE constricted noncircular capillaries; gas bubble snap-off; pressure-driven flow ID THIN ANNULAR FILM; POROUS-MEDIA; POLYGONAL CAPILLARIES; LONG BUBBLES; LAMINAR-FLOW; FOAM FLOW; MOBILIZATION; GRADIENT; MECHANISMS; DYNAMICS AB A model for snap-off of a gas thread ina constricted, cornered pore is developed. The time for wetting liquid to accumulate at a pore throat into an unstable collar is examined, as is the time for the resulting pore-spanning lens to be displaced from the pore so that snap-off may repeat. A corner-flow hydrodynamic analysis for the accumulation rate of wetting liquid due to both gradients in interfacial curvature and in applied liquid-phase pressure reveals that wetting-phase pressure gradients significantly increase the frequency of liquid accumulation for snap-off, as compared to liquid rearrangement driven only by differences in pore-wall curvature. For moderate and large pressure gradients, the frequency of accumulation increases linearly with pressure gradient, because of the increased rate of wetting liquid flow along pore corners. Pore topology is important to the theory, because pores with relatively small throats connected to large bodies demonstrate excellent ability to snap off gas threads even when the initial capillary pressure is high or equivalently when the liquid saturation is low. A macroscopic momentum balance across the lens, resulting from snap-off, reveals that lens displacement rates are not linear with the imposed pressure drop. Instead, the frequency of lens displacement scales with powers between 0.5 and 0.6 for pores with dimensionless constriction radii between 0.15 and 0.40. Statistical percolation arguments are employed to form a generation rate expression and connect pore-level foam generation events to macroscopic pressure gradients in porous media. The rate of foam generation by capillary snap-off increases linearly with the liquid-phase pressure gradient and according to a power-law relationship with respect to the imposed gas-phase pressure gradient. C1 UNIV CALIF BERKELEY,LAWRENCE BERKELEY LAB,DIV EARTH SCI,BERKELEY,CA 94720. UNIV CALIF BERKELEY,DEPT CHEM ENGN,BERKELEY,CA 94720. NR 52 TC 42 Z9 42 U1 2 U2 14 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 OCT 15 PY 1996 VL 117 IS 1-2 BP 55 EP 76 DI 10.1016/0927-7757(96)03637-0 PG 22 WC Chemistry, Physical SC Chemistry GA VJ284 UT WOS:A1996VJ28400007 ER PT J AU Shen, ZY PardingtonPurtymun, PE Comeaux, JC Moyzis, RK Chen, DJ AF Shen, ZY PardingtonPurtymun, PE Comeaux, JC Moyzis, RK Chen, DJ TI Associations of UBE21 with RAD52, UBL1, p53, and RAD51 proteins in a yeast two-hybrid system SO GENOMICS LA English DT Article ID UBIQUITIN-CONJUGATING ENZYME; CARRIER PROTEIN; DNA-REPAIR; DEGRADATION; RECOMBINATION; PURIFICATION; CONSERVATION; PATHWAY; CLONING; CELLS AB The yeast RAD52-dependent pathway is involved in DNA recombination and double-strand break repair. Yeast ubiquitin-conjugating enzyme UBCS participates in S- and M-phase cyclin degradation and mitotic control. Using the human RAD52 protein as the ''bait'' in a yeast two-hybrid system, we have identified a human homolog of yeast UBCS, designated UBE2I, that interacts with RAD52, RAD5I, p53, and a ubiquitin-like protein UBL1. These interactions are UBE2I-specific, since another DNA repair-related ubiquitin-conjugating enzyme, RAD6 (UBC2), does not interact with these proteins. The interaction of UBE2I with RAD52 is mediated by RAD52's self-association region. These results suggest that the RAD52-dependent processes, cell cycle control, p53-mediated pathway(s), and ubiquitination interact through human UBE2I. (C) 1996 Academic Press, Inc. C1 LOS ALAMOS NATL LAB,DIV LIFE SCI,DNA DAMAGE & REPAIR GRP,LOS ALAMOS,NM 87545. LOS ALAMOS NATL LAB,CTR HUMAN GENOME STUDIES,LOS ALAMOS,NM 87545. FU NCI NIH HHS [CA50519] NR 22 TC 120 Z9 120 U1 1 U2 1 PU ACADEMIC PRESS INC JNL-COMP SUBSCRIPTIONS PI SAN DIEGO PA 525 B ST, STE 1900, SAN DIEGO, CA 92101-4495 SN 0888-7543 J9 GENOMICS JI Genomics PD OCT 15 PY 1996 VL 37 IS 2 BP 183 EP 186 DI 10.1006/geno.1996.0540 PG 4 WC Biotechnology & Applied Microbiology; Genetics & Heredity SC Biotechnology & Applied Microbiology; Genetics & Heredity GA VN667 UT WOS:A1996VN66700005 PM 8921390 ER PT J AU Gosling, JT Riley, P AF Gosling, JT Riley, P TI The acceleration of slow coronal mass ejections in the high-speed solar wind SO GEOPHYSICAL RESEARCH LETTERS LA English DT Article ID HELIOGRAPHIC LATITUDES; ULYSSES AB Using a one-dimensional hydrodynamic code we have simulated the radial evolution of heliospheric disturbances produced by slow coronal mass ejections (CMEs) embedded in much faster leading and trailing ambient solar wind. We find that pressure gradients induced by initial speed differences between slow CMEs and faster ambient wind can produce large accelerations of the CMEs, eventually nearly up to the speed of the ambient wind. The compressions, rarefactions, and shocks associated with this acceleration persist to large heliocentric distances. Comparison with observations reveals that such effects helped accelerate two of the six high-latitude CME events observed by Ulysses. RP Gosling, JT (reprint author), LOS ALAMOS NATL LAB,MS D466,LOS ALAMOS,NM 87545, USA. NR 7 TC 48 Z9 48 U1 0 U2 0 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 SN 0094-8276 J9 GEOPHYS RES LETT JI Geophys. Res. Lett. PD OCT 15 PY 1996 VL 23 IS 21 BP 2867 EP 2870 DI 10.1029/96GL02843 PG 4 WC Geosciences, Multidisciplinary SC Geology GA VM610 UT WOS:A1996VM61000001 ER PT J AU Gary, SP McKean, ME Winske, D AF Gary, SP McKean, ME Winske, D TI Proton temperature anisotropy in the magnetosheath: Hybrid simulations SO GEOPHYSICAL RESEARCH LETTERS LA English DT Article ID PLASMA DEPLETION LAYER; CYCLOTRON INSTABILITY; INVERSE CORRELATION; MIRROR INSTABILITY; MAGNETIC-FIELD; BETA; SHOCKS AB Scattering by enhanced fluctuations from the electromagnetic proton cyclotron instability imposes an up per bound on the proton temperature anisotropy of the form T-perpendicular to p/T-parallel to p - 1 = S-p/beta(parallel to p)(alpha p). Here beta(parallel to p) is the proton beta based on T-parallel to p and the directional subscripts indicate directions perpendicular and parallel to the background magnetic field. This paper describes the analysis of the proton temperature anisotropy in two-dimensional hybrid simulations of quasiperpendicular shocks and their associated magnetosheaths. Three simulations are considered: at low, intermediate, and high upstream Mach numbers. Considering results from well downstream of all three shocks as one data set, an upper bound on the proton temperature anisotropy fits the above equation with alpha(p) = 0.5. This compares favorably to alpha(p) values from other simulations and from sheath observations. C1 UNIV CALIF SAN DIEGO,DEPT ELECT & COMP ENGN,LA JOLLA,CA 92093. RP Gary, SP (reprint author), LOS ALAMOS NATL LAB,MS D466,LOS ALAMOS,NM 87545, USA. NR 24 TC 8 Z9 8 U1 0 U2 0 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 SN 0094-8276 J9 GEOPHYS RES LETT JI Geophys. Res. Lett. PD OCT 15 PY 1996 VL 23 IS 21 BP 2887 EP 2890 DI 10.1029/96GL02882 PG 4 WC Geosciences, Multidisciplinary SC Geology GA VM610 UT WOS:A1996VM61000006 ER PT J AU TenCate, JA Shankland, TJ AF TenCate, JA Shankland, TJ TI Slow dynamics in the nonlinear elastic response of Berea sandstone SO GEOPHYSICAL RESEARCH LETTERS LA English DT Article AB A typical resonance curve-measured acceleration versus drive frequency-made on a thin bar of rock shows peak bending with a softening (nonlinear) modulus as drive levels are increased. The shapes of these nonlinear resonance curves were found in earlier work to depend somewhat on sweep rate; these ''slow dynamics'' are now examined and quantified. We have measured slow dynamics in a 0.3 m long, 50 mm diameter bar of Berea sandstone under ambient conditions. Peak strain levels during the experiments ranged from 10(-11) to 10(-5) at driving frequencies near 4 kHz, the fundamental longitudinal resonance frequency of the bar. Slow dynamics begin to manifest themselves at strain amplitudes above 10(-6) at ambient conditions and at the onset of nonlinear peak bending. Strains above this value condition the rock, altering its response for minutes to hours after the drive has been turned off. RP TenCate, JA (reprint author), LOS ALAMOS NATL LAB,DIV EARTH & ENVIRONM SCI,LOS ALAMOS,NM 87545, USA. NR 12 TC 102 Z9 105 U1 0 U2 0 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 SN 0094-8276 J9 GEOPHYS RES LETT JI Geophys. Res. Lett. PD OCT 15 PY 1996 VL 23 IS 21 BP 3019 EP 3022 DI 10.1029/96GL02884 PG 4 WC Geosciences, Multidisciplinary SC Geology GA VM610 UT WOS:A1996VM61000039 ER PT J AU Tautges, TJ Blacker, T Mitchell, SA AF Tautges, TJ Blacker, T Mitchell, SA TI The whisker weaving algorithm: A connectivity-based method for constructing all-hexahedral finite element meshes SO INTERNATIONAL JOURNAL FOR NUMERICAL METHODS IN ENGINEERING LA English DT Article DE mesh generation; hexahedral; whisker weaving; duality ID GENERATION AB This paper introduces a new algorithm called whisker weaving for constructing unstructured, all-hexahedral finite element meshes. Whisker weaving is based on the Spatial Twist Continuum (STC), a global interpretation of the geometric dual of an all-hexahedral mesh. Whisker weaving begins with a closed, all-quadrilateral surface mesh bounding a solid geometry, then constructs hexahedral element connectivity advancing into the solid. The result of the whisker weaving algorithm is a complete representation of hex mesh connectivity only: Actual mesh node locations are determined afterwards. The basic step of whisker weaving is to form a hexahedral element by crossing or intersecting dual entities. This operation, combined with seaming or joining operations in dual space, is sufficient to mesh simple block problems. When meshing more complex geometries, certain other dual entities appear such as blind chords, merged sheets, and self-intersecting chords. Occasionally specific types of invalid connectivity arise. These are detected by a general method based on repeated STC edges; This leads into a strategy for resolving some cases of invalidities immediately. The whisker weaving implementation has so far been successful at generating meshes for simple block-type geometries and for some non-block geometries. Mesh sizes are currently limited to a few hundred elements. While the size and complexity of meshes generated by whisker weaving are currently limited, the algorithm shows promise for extension to much more general problems. C1 FLUID DYNAM INT,EVANSTON,IL 60201. RP Tautges, TJ (reprint author), SANDIA NATL LABS,PARALLEL COMP SCI DEPT,POB 5800,ALBUQUERQUE,NM 87185, USA. NR 15 TC 114 Z9 119 U1 0 U2 4 PU JOHN WILEY & SONS LTD PI W SUSSEX PA BAFFINS LANE CHICHESTER, W SUSSEX, ENGLAND PO19 1UD SN 0029-5981 J9 INT J NUMER METH ENG JI Int. J. Numer. Methods Eng. PD OCT 15 PY 1996 VL 39 IS 19 BP 3327 EP 3349 PG 23 WC Engineering, Multidisciplinary; Mathematics, Interdisciplinary Applications SC Engineering; Mathematics GA VJ642 UT WOS:A1996VJ64200006 ER PT J AU Haschke, JM Allen, TH Stakebake, JL AF Haschke, JM Allen, TH Stakebake, JL TI Reaction kinetics of plutonium with oxygen, water and humid air: Moisture enhancement of the corrosion rate SO JOURNAL OF ALLOYS AND COMPOUNDS LA English DT Article DE plutonium; oxidation; corrosion; kinetics ID OXIDATION AB Kinetic measurements for the reactions of unalloyed plutonium with water vapor and oxygen in the 35 to 400 degrees C range show that moisture enhancement of the corrosion rate is confined to a temperature regime below 200 degrees C. Zn combination with kinetic data from literature sources and measurements with air at 25 degrees C, the data define a rate-temperature envelope in which the corrosion reaction is accelerated by increasing water pressure. The lower boundary of the envelope is defined by an Arrhenius relationship based on rates measured in the moisture-independent regime above 200 degrees C and in the moisture-dependent: regime at lower temperatures. As defined by experimental data and the equilibrium vapor pressure of water, the upper envelope boundary indicates that moisture dependence is confined to the -25 to 200 degrees C range with a rate maximum near 110 degrees C. Activation energies within the envelope vary systematically with water pressure from 17.9 kcal mol(-1) in dry (less than 1 ppm H2O) air to 34.4 kcal mol(-1) in water-saturated air. The corrosion rate is independent of oxygen pressure and has a square-root dependence on water pressure. The chemistry of moisture-enhanced corrosion is defined by results showing that plutonium oxide catalyzes the combination of hydrogen and oxygen. Hydrogen formed by the inherently rapid reaction of water with plutonium catalytically recombines with oxygen at the gas-oxide interface of the reacting metal. Kinetic anomalies attributed to reaction of beta-phase plutonium in earlier studies are correlated with the presence of trace amounts of moisture in the experimental systems. Accelerated corrosion in moist argon is discussed and effects of alloying and humidity on the corrosion rate are compared. C1 SCI APPLICAT INT CORP,GOLDEN,CO 80402. RP Haschke, JM (reprint author), LOS ALAMOS NATL LAB,POB 1663,LOS ALAMOS,NM 87545, USA. NR 29 TC 41 Z9 44 U1 1 U2 14 PU ELSEVIER SCIENCE SA LAUSANNE PI LAUSANNE 1 PA PO BOX 564, 1001 LAUSANNE 1, SWITZERLAND SN 0925-8388 J9 J ALLOY COMPD JI J. Alloy. Compd. PD OCT 15 PY 1996 VL 243 IS 1-2 BP 23 EP 35 DI 10.1016/S0925-8388(96)02328-6 PG 13 WC Chemistry, Physical; Materials Science, Multidisciplinary; Metallurgy & Metallurgical Engineering SC Chemistry; Materials Science; Metallurgy & Metallurgical Engineering GA VX976 UT WOS:A1996VX97600008 ER PT J AU Swenson, D Morosin, B AF Swenson, D Morosin, B TI On the preparation and crystal structure of a new form of PtGa2 SO JOURNAL OF ALLOYS AND COMPOUNDS LA English DT Article DE PtGa2; Pt-Ga; fluorite structure; crystal structure; phase transformations; phase equilibria; X-ray diffraction ID OPTICAL-PROPERTIES; BAND-STRUCTURE; THIN-FILMS; GALLIUM; AUAL2 AB The crystal structure of the silver-colored form of PtGa2 has been reported for the first time. It belongs to the space group I4(1)/acd, with the lattice parameters a = 8.5544(4) and c = 21.574(17) Angstrom, and Z = 32. The structure consists of layers of Pt and Ga stacked along the c axis, in which two crystallographically different Pt and Ga atoms have similar environments involving eight and nine nearest neighbors respectively. Based on some recent crystallographic data reported in the literature, this structural arrangement may be the prototype for a family of ternary platinum metal-Group B-based phases. The present investigation also necessitates changes in the currently accepted Ga-Pt phase diagram. According to the present study, stoichiometric PtGa2 undergoes a structural transformation upon cooling from a brass-colored fluorite structure to the silver-colored, tetragonal structure described above. However, transformation is inhibited if the composition of the fluorite-structured phase is Ga-poor. This behavior is reminiscent of that of defect-stabilized cubic ZrO2, which also possesses the fluorite structure. C1 UNIV WISCONSIN,MAT SCI PROGRAM,MADISON,WI 53706. SANDIA NATL LABS,ALBUQUERQUE,NM 87185. NR 27 TC 4 Z9 4 U1 1 U2 3 PU ELSEVIER SCIENCE SA LAUSANNE PI LAUSANNE 1 PA PO BOX 564, 1001 LAUSANNE 1, SWITZERLAND SN 0925-8388 J9 J ALLOY COMPD JI J. Alloy. Compd. PD OCT 15 PY 1996 VL 243 IS 1-2 BP 173 EP 181 DI 10.1016/S0925-8388(96)02373-0 PG 9 WC Chemistry, Physical; Materials Science, Multidisciplinary; Metallurgy & Metallurgical Engineering SC Chemistry; Materials Science; Metallurgy & Metallurgical Engineering GA VX976 UT WOS:A1996VX97600033 ER PT J AU Turkot, BA Lagow, BW Robertson, IM Forbes, DV Coleman, JJ Rehn, LE Baldo, PM AF Turkot, BA Lagow, BW Robertson, IM Forbes, DV Coleman, JJ Rehn, LE Baldo, PM TI Depth dependence of ion implantation damage in AlxGa1-xAs/GaAs heterostructures SO JOURNAL OF APPLIED PHYSICS LA English DT Article ID AMORPHIZATION; GAAS; ALAS AB To determine the influence of interface type on the accumulation of damage and ion mixing in GaAs/AlxGa1-xAs heterostructures, the damage produced by ion implantation at 77 K in single-layer (GaAs/AlxGa1-xAs/GaAs) and double-layer (GaAs/AlxGa1-xAs/GaAs/AlxGa1-xAs/GaAs) heterostructures has been investigated by using a combination of Rutherford backscattering spectrometry and transmission electron microscopy, In the single-layer geometry, the degree of disorder increases with depth and the mixing is greater at the AlxGa1-xAs on GaAs interface than at the GaAs on AlxGa1-xAs one. The damage distribution in the sample with the double-layer geometry was different in the two layers, but overall it was similar to that in the single-layer geometry. These trends were observed in samples with x=0.6 and 0.2. These results indicate that migration of charged defects due to the presence of an implantation-induced electric field is not responsible for the asymmetry in the damage accumulation across the layer, the interface disorder and ion mixing, and the initiation of amorphization at interfaces. Instead, these effects can be better understood in terms of the depth dependence of the density of cascade events. (C) 1996 American Institute of Physics. C1 UNIV ILLINOIS, MAT RES LAB, URBANA, IL 61801 USA. ARGONNE NATL LAB, ARGONNE, IL 60439 USA. RP Turkot, BA (reprint author), UNIV ILLINOIS, DEPT MAT SCI & ENGN, 1304 W GREEN ST, URBANA, IL 61801 USA. RI Coleman, James/C-9703-2011 NR 15 TC 15 Z9 15 U1 2 U2 2 PU AMER INST PHYSICS PI MELVILLE PA CIRCULATION & FULFILLMENT DIV, 2 HUNTINGTON QUADRANGLE, STE 1 N O 1, MELVILLE, NY 11747-4501 USA SN 0021-8979 J9 J APPL PHYS JI J. Appl. Phys. PD OCT 15 PY 1996 VL 80 IS 8 BP 4366 EP 4371 DI 10.1063/1.363395 PG 6 WC Physics, Applied SC Physics GA VM272 UT WOS:A1996VM27200019 ER PT J AU AlShareef, HN Dimos, D Warren, WL Tuttle, BA AF AlShareef, HN Dimos, D Warren, WL Tuttle, BA TI Voltage offsets and imprint mechanism in SrBi2Ta2O9 thin films SO JOURNAL OF APPLIED PHYSICS LA English DT Article ID INTERNAL BIAS; CERAMICS; CAPACITORS; BATIO3 AB It is shown that voltage shifts in the hysteresis response of SrBi2Ta2O9 (SET) thin-film capacitors can be induced using both thermal and optical methods. These voltage shifts are important since they can lead to imprint failure in ferroelectric memory devices. It is suggested that the voltage shifts in the hysteresis curve of SET are caused by trapping of electronic charge carriers near the film/electrode interfaces, as has been previously reported for the Pb(Zr,Ti)O-3 (PZT) system. In addition, a direct correlation is established between the magnitude and sign of remanent polarization (P-r) and the thermally induced voltage shifts (V-i), where V-i = alpha P-r + beta. It is also found that, unlike the PZT system, the thermally induced voltage shifts in SET are smaller than those optically induced. One. possible implication of this result is that the contribution of defect-dipole complexes to the voltage shifts in SET is negligible. We suggest that the smaller contribution of defect-dipole complexes to the voltage shifts in SET may be related to a smaller oxygen vacancy concentration in the perovskite sublattice of SET as compared to that of PZT. (C) 1996 American Institute of Physics. RP AlShareef, HN (reprint author), SANDIA NATL LABS,ALBUQUERQUE,NM 87185, USA. RI Alshareef, Husam Niman/A-2000-2015 OI Alshareef, Husam Niman/0000-0001-5029-2142 NR 17 TC 55 Z9 56 U1 0 U2 15 PU AMER INST PHYSICS PI WOODBURY PA CIRCULATION FULFILLMENT DIV, 500 SUNNYSIDE BLVD, WOODBURY, NY 11797-2999 SN 0021-8979 J9 J APPL PHYS JI J. Appl. Phys. PD OCT 15 PY 1996 VL 80 IS 8 BP 4573 EP 4577 DI 10.1063/1.363440 PG 5 WC Physics, Applied SC Physics GA VM272 UT WOS:A1996VM27200052 ER PT J AU Lange, R Junge, KE Zollner, S Iyer, SS Powell, AP Eberl, K AF Lange, R Junge, KE Zollner, S Iyer, SS Powell, AP Eberl, K TI Dielectric response of strained and relaxed Si1-x-yGexCy alloys grown by molecular beam epitaxy on Si(001) SO JOURNAL OF APPLIED PHYSICS LA English DT Article ID PIEZO-OPTICAL RESPONSE; SPECTROSCOPIC ELLIPSOMETRY; UNIAXIAL-STRESS; TEMPERATURE-DEPENDENCE; SEMICONDUCTOR ALLOYS; SI1-YCY ALLOYS; SI; SILICON; GE; TRANSITIONS AB Using spectroscopic ellipsometry, we measured the pseudodielectric function of Si(1-x-y)G(x)C(y) alloys (0 less than or equal to x less than or equal to 0.48,0 less than or equal to y less than or equal to 0.05) grown on Si(001) using molecular beam epitaxy, For pseudomorphically strained layers, the energy shifts of the E(1), E(1) + Delta(1), E(0)', and E(2) transitions are determined by line shape analysis and are due to alloy composition effects, as well as hydrostatic and shear strain. We developed expressions for hydrostatic and shear shift from continuum elasticity theory, using deformation potentials for Si and Ge, for biaxial stress parallel to the (001) growth plane in a diamond or zinc blende-type crystal and applied this to the ternary Si-Ge-C alloy, The energies of E(1) and its spin-orbit split partner E(1) + Delta(1) agree fairly well with theory. The E(2) transitions in Si1-xGex at around 4.3 eV depend linearly on Ge concentration, In case of relaxed layers, the E(1) and E(1) + Delta(1) transitions are inhomogeneously broadened due to the influence of misfit and threading dislocations. For a silicon cap on top of a dislocated, relaxed SiGe layer, eve recovered the hulk Si dielectric function. (C) 1996 American Institute of Physics. C1 IOWA STATE UNIV,DEPT PHYS & ASTRON,AMES,IA 50011. SIBOND LLC,HOPEWELL JCT,NY 12533. ADV TECHNOL MAT,DANBURY,CT 06810. MAX PLANCK INST FESTKORPERFORSCH,D-70569 STUTTGART,GERMANY. RP Lange, R (reprint author), US DOE,AMES LAB,AMES,IA 50011, USA. RI Zollner, Stefan/B-4858-2012 OI Zollner, Stefan/0000-0001-7752-7941 NR 62 TC 24 Z9 24 U1 0 U2 3 PU AMER INST PHYSICS PI WOODBURY PA CIRCULATION FULFILLMENT DIV, 500 SUNNYSIDE BLVD, WOODBURY, NY 11797-2999 SN 0021-8979 J9 J APPL PHYS JI J. Appl. Phys. PD OCT 15 PY 1996 VL 80 IS 8 BP 4578 EP 4586 DI 10.1063/1.363827 PG 9 WC Physics, Applied SC Physics GA VM272 UT WOS:A1996VM27200053 ER PT J AU Shannon, MA Rubinsky, B Russon, RE AF Shannon, MA Rubinsky, B Russon, RE TI Mechanical stress power measurements during high-power laser ablation SO JOURNAL OF APPLIED PHYSICS LA English DT Article ID SHOCK-WAVES; PIEZOELECTRIC PROBE; FILMS; PULSES; ALUMINUM; TARGETS; AIR AB Laser-induced stresses have been studied extensively to understand macroscopic phenomenon during high-power laser ablation of solids. Recently, a norm of stress times the rate of change in stress, similar to mechanical stress power, was monitored acoustically in the target and ambient medium during high-power laser-material interactions, and compared with stress measurements. This study investigates the relationship between stress and the stress powerlike measurements (P*), and their dependence on laser energy, intensity, and spot size. The importance of different components of stress on the measurements is also considered. Results from ablation of aluminum targets by a 30 ns uv excimer laser are presented that show changes in P* with laser energy coupling, and the dependence of P* on laser intensity and stress components. Potential issues are raised for further study of stress power as a diagnostic tool of laser-material interactions and as a fundamental mechanism of laser-energy coupling. (C) 1996 American Institute of Physics. C1 UNIV CALIF BERKELEY,DEPT MECH ENGN,BERKELEY,CA 94720. LAWRENCE BERKELEY LAB,BERKELEY,CA 94720. RP Shannon, MA (reprint author), UNIV ILLINOIS,DEPT MECH & IND ENGN,1206 W GREEN ST,URBANA,IL 61801, USA. RI Rubinsky, Boris/B-4439-2010 OI Rubinsky, Boris/0000-0002-2794-1543 NR 29 TC 3 Z9 3 U1 1 U2 1 PU AMER INST PHYSICS PI WOODBURY PA CIRCULATION FULFILLMENT DIV, 500 SUNNYSIDE BLVD, WOODBURY, NY 11797-2999 SN 0021-8979 J9 J APPL PHYS JI J. Appl. Phys. PD OCT 15 PY 1996 VL 80 IS 8 BP 4665 EP 4672 DI 10.1063/1.363450 PG 8 WC Physics, Applied SC Physics GA VM272 UT WOS:A1996VM27200068 ER PT J AU Quinones, I Guiochon, G AF Quinones, I Guiochon, G TI Derivation and application of a Jovanovic-Freundlich isotherm model for single-component adsorption on heterogeneous surfaces SO JOURNAL OF COLLOID AND INTERFACE SCIENCE LA English DT Article DE adsorption; Freundlich isotherm; isotherm; isotherm model; Jovanovic isotherm ID ACTIVATED CARBON; ORGANIC SOLUTES; SILICA-GEL; GAS; CHROMATOGRAPHY; EQUILIBRIA; EQUATIONS AB A new Jovanovic-Freundlich isotherm model is derived for describing single-component adsorption equilibria on heterogeneous surfaces, The equation is obtained by assuming that the rate of decrease of the fraction of the surface unoccupied by the adsorbate molecules is proportional to a certain power of the partial pressure of the adsorbate, The equation reduces to the Jovanovic equation when the surface becomes homogeneous, At low pressures, the equation reduces to the Freundlich isotherm but at high pressures, a monolayer coverage is achieved, This model has been applied successfully to the description of the adsorption behavior of a series of chlorinated hydrocarbons on a microporous silicagel, at different temperatures, The monolayer capacity and the heterogeneity parameter exhibit a weak temperature dependence, The third parameter of the model decreases exponentially with increasing temperature, The fit of the experimental data to the new model described is shown to be better than the comparable fits to classical isotherms used for heterogeneous surfaces, The energy distribution function corresponding to the model for Langmuir local adsorption behavior was derived using the Sips procedure and evaluated numerically in a few selected cases. This distribution is an exponential decay. (C) 1996 Academic Press, Inc. C1 UNIV TENNESSEE,DEPT CHEM,KNOXVILLE,TN 37996. CTR QUIM FARMACEUT,DEPT TECNOL,HAVANA 11600,CUBA. OAK RIDGE NATL LAB,DIV CHEM & ANALYT SCI,OAK RIDGE,TN 37831. NR 42 TC 44 Z9 45 U1 2 U2 16 PU ACADEMIC PRESS INC JNL-COMP SUBSCRIPTIONS PI SAN DIEGO PA 525 B ST, STE 1900, SAN DIEGO, CA 92101-4495 SN 0021-9797 J9 J COLLOID INTERF SCI JI J. Colloid Interface Sci. PD OCT 15 PY 1996 VL 183 IS 1 BP 57 EP 67 DI 10.1006/jcis.1996.0518 PG 11 WC Chemistry, Physical SC Chemistry GA VV314 UT WOS:A1996VV31400008 ER PT J AU Petersson, NA AF Petersson, NA TI Fast numerical computation of 2D free surface jet flow with surface tension SO JOURNAL OF COMPUTATIONAL PHYSICS LA English DT Article ID STABILITY AB A system of partial differential equations that approximate the governing equations for inviscid free surface flow subject to surface tension is presented. The approximation is based on linearizing the velocity together with a small scale approximation of the perturbation of the velocity. Two Dirichlet problems must be solved to form the approximate system, after which it can be evolved without solving Dirichlet problems. The accuracy of the solution is determined by how often the velocity term is linearized. This time-interval is called Delta T. We show that the error in the solution of the approximate system at a fixed time T is of the order O(Delta T-2). We demonstrate numerically that the error is closely correlated to the size of the normal velocity and that there is a stability limit of the form Delta T less than or equal to C/(u(n)\(infinity))(gamma) where u(n) denotes the normal velocity of the free surface and gamma approximate to 2.6. Importantly, C is independent of the resolution, so the time-step Delta T can be chosen independently of the number of grid points, N. This is in contrast to the original system, where the stability limit of the time-step is Delta t less than or equal to O(N--3/2) and a fixed number of Dirichlet problems have to be solved per time-step. By numerical experiments, we demonstrate that the approximate system requires less than 10% of the CPU time used by the original system to solve the problem very accurately. (C) 1996 Academic Press, Inc. RP Petersson, NA (reprint author), LOS ALAMOS NATL LAB,CTR NONLINEAR STUDIES,LOS ALAMOS,NM 87545, USA. NR 17 TC 1 Z9 1 U1 0 U2 0 PU ACADEMIC PRESS INC JNL-COMP SUBSCRIPTIONS PI SAN DIEGO PA 525 B ST, STE 1900, SAN DIEGO, CA 92101-4495 SN 0021-9991 J9 J COMPUT PHYS JI J. Comput. Phys. PD OCT 15 PY 1996 VL 128 IS 2 BP 409 EP 426 DI 10.1006/jcph.1996.0220 PG 18 WC Computer Science, Interdisciplinary Applications; Physics, Mathematical SC Computer Science; Physics GA VN964 UT WOS:A1996VN96400012 ER PT J AU Morel, JE Wareing, TA Smith, K AF Morel, JE Wareing, TA Smith, K TI A linear-discontinuous spatial differencing scheme for S-n radiative transfer calculations SO JOURNAL OF COMPUTATIONAL PHYSICS LA English DT Article ID SYNTHETIC ACCELERATION SCHEME; NUMERICAL TRANSPORT PROBLEMS; ASYMPTOTIC SOLUTIONS; DIFFUSIVE REGIMES; OPTICALLY THICK; EQUATIONS AB Various types of linear-discontinuous spatial differencing schemes have been developed for the S-n (discrete-ordinates) equations approximating the linear Boltzmann transport equation. It has been shown through an asymptotic analysis that the 1D slab-geometry lumped linear-discontinuous scheme not only goes over to a convergent and robust differencing of the diffusion equation in the monoenergetic thick diffusion limit, but it also yields the correct interior solution, even when boundary layers are left unresolved by the spatial mesh. In the present work we generalize this scheme to obtain a 1D slab-geometry lumped linear-discontinuous scheme for the nonlinear radiative transfer equation and the associated material temperature equation. We present a full nonlinear energy-dependent asymptotic analysis of the behavior of this scheme in the thick equilibrium-diffusion limit. We find that this scheme goes over to a convergent and robust differencing of the equilibrium-diffusion equation on the interior of the mesh, but it does not yield the exact interior solution when boundary layers are left unresolved by the spatial mesh. Nevertheless, the interior solution obtained with spatially unresolved boundary layers is always well behaved and fairly accurate. Computational results are presented which test the predictions of our asymptotic analysis and demonstrate the efficiency of our solution technique. (C) 1996 Academic Press, Inc. RP Morel, JE (reprint author), LOS ALAMOS NATL LAB,LOS ALAMOS,NM 87545, USA. NR 19 TC 53 Z9 59 U1 0 U2 3 PU ACADEMIC PRESS INC JNL-COMP SUBSCRIPTIONS PI SAN DIEGO PA 525 B ST, STE 1900, SAN DIEGO, CA 92101-4495 SN 0021-9991 J9 J COMPUT PHYS JI J. Comput. Phys. PD OCT 15 PY 1996 VL 128 IS 2 BP 445 EP 462 DI 10.1006/jcph.1996.0223 PG 18 WC Computer Science, Interdisciplinary Applications; Physics, Mathematical SC Computer Science; Physics GA VN964 UT WOS:A1996VN96400015 ER PT J AU Armstrong, DJ Smith, AV AF Armstrong, DJ Smith, AV TI Tendency of nanosecond optical parametric oscillators to produce purely phase-modulated light SO OPTICS LETTERS LA English DT Article ID LASER AB We show that nanosecond optical parametric oscillators pumped well above threshold by single-longitudinal-mode pulses produce signal and idler light that is nearly purely phase modulated under a variety of conditions, including both seeded and unseeded operation. (C) 1996 Optical Society of America RP Armstrong, DJ (reprint author), SANDIA NATL LABS,LASERS OPT & REMOTE SENSING DEPT,POB 5800,ALBUQUERQUE,NM 87185, USA. NR 8 TC 12 Z9 12 U1 0 U2 4 PU OPTICAL SOC AMER PI WASHINGTON PA 2010 MASSACHUSETTS AVE NW, WASHINGTON, DC 20036 SN 0146-9592 J9 OPT LETT JI Opt. Lett. PD OCT 15 PY 1996 VL 21 IS 20 BP 1634 EP 1636 DI 10.1364/OL.21.001634 PG 3 WC Optics SC Optics GA VL834 UT WOS:A1996VL83400006 PM 19881750 ER PT J AU Lidorikis, E Li, QM Soukoulis, CM AF Lidorikis, E Li, QM Soukoulis, CM TI Wave propagation in nonlinear multilayer structures SO PHYSICAL REVIEW B LA English DT Article ID OPTICAL-RESPONSE; SUPERLATTICES; BISTABILITY AB We investigate the adequacy of the Kronig-Penney delta-function model in describing the electromagnetic wave propagation in periodic structures consisting of thin layers of materials with an intensity-dependent dielectric constant. We find that the model captures the most essential features of nonlinear response to radiation. Excellent agreement is found between the results from the delta-function model and the exact solutions of nonlinear wave equations. However, discrepancies do exist below the bottom of transmission bands due to the rigidness of the band edge in the delta-function model. Consequently, gap solitons cannot form in the delta-function model when the nonlinear Ken coefficient is positive. C1 IOWA STATE UNIV SCI & TECHNOL,DEPT PHYS & ASTRON,AMES,IA 50011. RP Lidorikis, E (reprint author), IOWA STATE UNIV SCI & TECHNOL,US DOE,AMES LAB,AMES,IA 50011, USA. RI Soukoulis, Costas/A-5295-2008; OI Lidorikis, Elefterios/0000-0002-9552-9366 NR 9 TC 39 Z9 44 U1 0 U2 2 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 0163-1829 J9 PHYS REV B JI Phys. Rev. B PD OCT 15 PY 1996 VL 54 IS 15 BP 10249 EP 10252 DI 10.1103/PhysRevB.54.10249 PG 4 WC Physics, Condensed Matter SC Physics GA VT674 UT WOS:A1996VT67400002 ER PT J AU Smith, DL Kogan, SM AF Smith, DL Kogan, SM TI Theory of ballistic-electron-emission microscopy of buried semiconductor heterostructures SO PHYSICAL REVIEW B LA English DT Article ID BAND-STRUCTURE; INTERFACES; SPECTROSCOPY; SCATTERING AB We extend the theoretical description of ballistic-electron-emission microscopy (BEEM) to the study of buried heterojunctions. We calculate the collector current and its first and second derivatives with respect to tip-base bias voltage for buried single-barrier and double-barrier resonant tunneling structures and show how they systematically vary with the parameters of the heterostructure. We show that the second derivative of the collector current is approximately a product of the heterostructure transmission coefficient and a slowly varying function of bias voltage. The calculated results are in good agreement with the first measurements of BEEM used to probe buried double-barrier heterostructures. RP Smith, DL (reprint author), LOS ALAMOS NATL LAB,POB 1663,LOS ALAMOS,NM 87545, USA. NR 13 TC 47 Z9 47 U1 0 U2 2 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 0163-1829 J9 PHYS REV B JI Phys. Rev. B PD OCT 15 PY 1996 VL 54 IS 15 BP 10354 EP 10357 DI 10.1103/PhysRevB.54.10354 PG 4 WC Physics, Condensed Matter SC Physics GA VT674 UT WOS:A1996VT67400029 ER PT J AU Sluiter, M Kawazoe, Y AF Sluiter, M Kawazoe, Y TI Prediction of matrix-precipitate interfacial free energies: Application to Al-Al3Li SO PHYSICAL REVIEW B LA English DT Article ID AG-AU ALLOYS; ISING-MODEL; BOUNDARIES AB Interfaces determine many properties of bulk materials; for example, the interfacial free energy plays a crucial factor in the nucleation, growth, and morphology of precipitates in alloys. So far, the complexity associated with the inherent interfacial disorder has eluded ab initio computation of its thermodynamic properties at finite temperatures. Here we show that a particular class of interfaces can be accurately modeled from first principles by combining the thermodynamics of the Ising Hamiltonian with the zero-temperature electronic total energies of small supercells. C1 TOHOKU UNIV,INST MAT RES,AOBA KU,SENDAI,MIYAGI 980,JAPAN. RP Sluiter, M (reprint author), BROOKHAVEN NATL LAB,DEPT PHYS,UPTON,NY 11973, USA. RI Kawazoe, Yoshiyuki/C-2998-2011; Sluiter, Marcel/E-6086-2010 OI Sluiter, Marcel/0000-0002-6514-4318 NR 26 TC 28 Z9 28 U1 0 U2 2 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 0163-1829 J9 PHYS REV B JI Phys. Rev. B PD OCT 15 PY 1996 VL 54 IS 15 BP 10381 EP 10384 DI 10.1103/PhysRevB.54.10381 PG 4 WC Physics, Condensed Matter SC Physics GA VT674 UT WOS:A1996VT67400036 ER PT J AU Ahuja, R Eriksson, O Johansson, B Auluck, S Wills, JM AF Ahuja, R Eriksson, O Johansson, B Auluck, S Wills, JM TI Electronic and optical properties of red HgI2 SO PHYSICAL REVIEW B LA English DT Article ID DENSITY-FUNCTIONAL THEORY; MERCURIC IODIDE; BRILLOUIN-ZONE; BAND-STRUCTURE; SPECIAL POINTS; SEMICONDUCTORS; SPECTRUM; SYSTEMS AB Within the local-density approximation we have used the linear muffin-tin orbital method, without geometrical approximations, to calculate the electronic structure of red HgI2. Using the self-consistent potential we have calculated the energy bands and from these derived the anisotropic frequency-dependent dielectric function and the reflectivity spectrum. The calculated dielectric function is in good agreement with the experimental data in contrast to previous theoretical work. The effect bf the spin-orbit coupling on the optical properties has also been studied and found to be significant. In this work we predict a rather large anisotropy in the dielectric function resulting from the low-symmetry crystal structure. C1 UNIV ROORKEE,DEPT PHYS,ROORKEE 247667,UTTAR PRADESH,INDIA. LOS ALAMOS NATL LAB,DIV THEORET,LOS ALAMOS,NM 87544. RP Ahuja, R (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 32 TC 38 Z9 40 U1 0 U2 5 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 0163-1829 J9 PHYS REV B JI Phys. Rev. B PD OCT 15 PY 1996 VL 54 IS 15 BP 10419 EP 10424 DI 10.1103/PhysRevB.54.10419 PG 6 WC Physics, Condensed Matter SC Physics GA VT674 UT WOS:A1996VT67400044 ER PT J AU Weitering, HH Shi, X Erwin, SC AF Weitering, HH Shi, X Erwin, SC TI Band dispersions of the pi-bonded-chain reconstruction of Si(111)3x1-Li: A critical evaluation of theory and experiment SO PHYSICAL REVIEW B LA English DT Article ID SCANNING-TUNNELING-MICROSCOPY; (ROOT(3)X-ROOT(3)R30-DEGREES AG/SI(111) SURFACE; TRANSMISSION ELECTRON-DIFFRACTION; 1ST-PRINCIPLES CALCULATIONS; TRANS-POLYACETYLENE; STRUCTURAL MODEL; PHOTOEMISSION; NA; SI(111)-(7X7); SI(111)2X1 AB The surface-state band-structure of the three-domain Si(111) 3 x 1-Li reconstruction has been determined using angle-resolved photoemission. Experimental band dispersions are compared to theoretical calculations for the extended Pandey model and the Seiwatz model. Even though the extended Pandey model is favored on the basis of scanning tunneling microscopy and total-energy considerations, the calculated surface states are inconsistent with experiment. The calculated states for the Seiwatz model are consistent with the experimental dispersion along the main symmetry direction (<(Gamma)over bar> (A) over bar) but serious discrepancies exist in other parts of the Brillouin zone. The disparity between the density-functional-theory calculations and experiment indicate that exchange and correlation in pi-bonded Si chains may need to be analyzed beyond the mean-field band-structure approach. C1 OAK RIDGE NATL LAB,DIV SOLID STATE,OAK RIDGE,TN 37831. USN,RES LAB,COMPLEX SYST THEORY BRANCH,WASHINGTON,DC 20375. RP Weitering, HH (reprint author), UNIV TENNESSEE,DEPT PHYS & ASTRON,KNOXVILLE,TN 37996, USA. RI Erwin, Steven/B-1850-2009 NR 51 TC 58 Z9 58 U1 0 U2 1 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 0163-1829 J9 PHYS REV B JI Phys. Rev. B PD OCT 15 PY 1996 VL 54 IS 15 BP 10585 EP 10592 DI 10.1103/PhysRevB.54.10585 PG 8 WC Physics, Condensed Matter SC Physics GA VT674 UT WOS:A1996VT67400061 ER PT J AU Alekseev, KN Berman, GP Campbell, DK Cannon, EH Cargo, MC AF Alekseev, KN Berman, GP Campbell, DK Cannon, EH Cargo, MC TI Dissipative chaos in semiconductor superlattices SO PHYSICAL REVIEW B LA English DT Article ID NEGATIVE DIFFERENTIAL CONDUCTIVITY; INJECTED SIGNAL; BLOCH OSCILLATIONS; COLLECTIVE EXCITATIONS; DETERMINISTIC CHAOS; MINIBAND TRANSPORT; SURFACE-PLASMONS; TIME-SERIES; LASER; VELOCITY AB We consider the motion of ballistic electrons in a miniband of a semiconductor superlattice (SSL) under the influence of an external, time-periodic electric field. We use a semiclassical, balance-equation approach, which incorporates elastic and inelastic scattering (as dissipation) and the self-consistent field generated by the electron motion. The coupling of electrons in the miniband to the self-consistent held produces a cooperative nonlinear oscillatory mode which, when interacting with the oscillatory external field and the intrinsic Bloch-type oscillatory mode, can lead to complicated dynamics, including dissipative chaos. For a range of values of the dissipation parameters we determine the regions in the amplitude-frequency plane of the external field in which chaos can occur. Our results suggest that for terahertz external fields of the amplitudes achieved by present-day free-electron lasers, chaos may be observable in SSL's. We clarify the nature of this interesting nonlinear dynamics in the superlattice-external-field system by exploring analogies to the Dicke model of an ensemble of two-level atoms coupled with a resonant cavity field, and to Josephson junctions. C1 LOS ALAMOS NATL LAB,DIV THEORET,LOS ALAMOS,NM 87545. LV KIRENSKII INST PHYS,KRASNOYARSK 660036,RUSSIA. UNIV ILLINOIS,DEPT PHYS,URBANA,IL 61801. RP Alekseev, KN (reprint author), LOS ALAMOS NATL LAB,CTR NONLINEAR STUDIES,LOS ALAMOS,NM 87545, USA. NR 89 TC 53 Z9 53 U1 0 U2 4 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 0163-1829 J9 PHYS REV B JI Phys. Rev. B PD OCT 15 PY 1996 VL 54 IS 15 BP 10625 EP 10636 DI 10.1103/PhysRevB.54.10625 PG 12 WC Physics, Condensed Matter SC Physics GA VT674 UT WOS:A1996VT67400066 ER PT J AU Moler, EJ Kellar, SA Huff, WRA Hussain, Z Chen, YF Shirley, DA AF Moler, EJ Kellar, SA Huff, WRA Hussain, Z Chen, YF Shirley, DA TI Spatial structure determination of (root 3x root 3)R30 degrees and (1.5x1.5)R18 degrees CO or Cu(111) using angle-resolved photoemission extended fine structure SO PHYSICAL REVIEW B LA English DT Article ID PHOTOELECTRON DIFFRACTION; SURFACES; CHEMISORPTION; ADSORPTION; SPECTROSCOPY; GEOMETRY; CU(100); COPPER; EELS AB We report a study of the spatial structure of (root 3x root 3)R30 degrees and (1.5x1.5)R18 degrees CO adsorbed on Cu (111), using the angle-resolved photoemission extended fine structure (ARPEFS) technique. The ARPEFS data were taken along the surface normal-emission direction with a sample temperature of 80 K. The CO molecule adsorbs on an atop site for both adsorption phases. Full multiple-scattering spherical-wave (MSSW) calculations were used to extract the C-Cu bond length and the first Cu-Cu layer spacing fur each adsorption phase. The C-Cu bond length is 1.91(1) Angstrom in the (root 3x root 3)R30 degrees phase and 1.91(2) Angstrom in the (1.5x1.5)R18 degrees phase. The first layer Cu-Cu spacing is 2.07(3) Angstrom, in the (root 3x root 3)R30 degrees phase. The first layer Cu-Cu spacing in the (1.5x1.5)R18 degrees phase is 2.01(4) Angstrom, a contraction of 3% from the clean metal value of 2.07 Angstrom. We calculate the bending mode force constant (1.5x1.5)R18 degrees phase to be k(delta)=2.2(1)x10(-12) dyn/cm rad from the above bond lengths combined with previously published infrared absorption frequencies. C1 PENN STATE UNIV,DEPT CHEM,UNIVERSITY PK,PA 16802. PENN STATE UNIV,DEPT PHYS,UNIVERSITY PK,PA 16802. RP Moler, EJ (reprint author), UNIV CALIF BERKELEY,LAWRENCE BERKELEY NATL LAB,BERKELEY,CA 94720, USA. NR 35 TC 28 Z9 28 U1 0 U2 3 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 0163-1829 J9 PHYS REV B JI Phys. Rev. B PD OCT 15 PY 1996 VL 54 IS 15 BP 10862 EP 10868 DI 10.1103/PhysRevB.54.10862 PG 7 WC Physics, Condensed Matter SC Physics GA VT674 UT WOS:A1996VT67400092 ER PT J AU Shirley, EL Benedict, LX Louie, SG AF Shirley, EL Benedict, LX Louie, SG TI Excitons in solid C-60 SO PHYSICAL REVIEW B LA English DT Article ID QUASI-PARTICLE; ELECTRONIC-PROPERTIES; C60; BUCKMINSTERFULLERENE; ABSORPTION; SPECTRA; SPECTROSCOPY; TRANSITIONS; IONIZATION; ENERGIES AB Exciton levels in undoped, solid C-60 are calculated using a model Hamiltonian. We find excitation energies of 1.58 and 1.30 eV for the lowest singlet and triplet exciton, respectively, in comparison with the measured energies of 1.83 and 1.55 eV. Singlet and triplet states have similar energy diagrams, wherein exciton states having T-2g, T-1g, G(g), and H-g Symmetries are separated by up to several tenths of an electron volt. As a function of crystal momentum? exciton energies exhibit dispersion from 20 to 40 meV. Theoretical pressure derivatives of exciton energies are presented. C1 UNIV CALIF BERKELEY, DEPT PHYS, BERKELEY, CA 94720 USA. UNIV CALIF BERKELEY, LAWRENCE BERKELEY LAB, DIV MAT SCI, BERKELEY, CA 94720 USA. RP Shirley, EL (reprint author), NATL INST STAND & TECHNOL, PHYS LAB, OPT TECH DIV, GAITHERSBURG, MD 20899 USA. NR 34 TC 47 Z9 47 U1 0 U2 11 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 OCT 15 PY 1996 VL 54 IS 15 BP 10970 EP 10977 DI 10.1103/PhysRevB.54.10970 PG 8 WC Physics, Condensed Matter SC Physics GA VT674 UT WOS:A1996VT67400104 ER PT J AU Galloway, HC Sautet, P Salmeron, M AF Galloway, HC Sautet, P Salmeron, M TI Structure and contrast in scanning tunneling microscopy of oxides: FeO monolayer on Pt(111) SO PHYSICAL REVIEW B LA English DT Article ID THEORETICAL-ANALYSIS; SURFACE-STRUCTURE; TIO2(110); STM; SPECTROSCOPY; SITE AB We applied electron-scattering quantum-chemistry theory to investigate the origin of contrast in scanning tunneling microscopy images of iron oxide grown on Pt(111). We show that (a) image contrast and surface topography are not directly related; (b) the maxima in the images occur over O positions for Pt tips and over Fe positions for O-terminated tips; (c) the shea-range corrugation is always due to O-pz orbitals, with a small but important contribution of Fe; and (d) the state that carriers most of the tunneling current is located near the Fermi level and is made mostly of O (pz) and Fe 3d(z2) orbitals. C1 UNIV CALIF BERKELEY,LAWRENCE BERKELEY LAB,DIV SCI MAT,BERKELEY,CA 94720. UNIV CALIF BERKELEY,DEPT PHYS,BERKELEY,CA 94720. ECOLE NORMALE SUPER,CHIM THEOR LAB,F-69464 LYON,FRANCE. INST RECH CATALYSE,CNRS,F-69626 VILLEURBANNE,FRANCE. RI Sautet, Philippe/G-3710-2014 OI Sautet, Philippe/0000-0002-8444-3348 NR 20 TC 87 Z9 87 U1 2 U2 15 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 0163-1829 J9 PHYS REV B JI Phys. Rev. B PD OCT 15 PY 1996 VL 54 IS 16 BP 11145 EP 11148 PG 4 WC Physics, Condensed Matter SC Physics GA VT675 UT WOS:A1996VT67500035 ER PT J AU Wang, LW Zunger, A AF Wang, LW Zunger, A TI Pseudopotential-based multiband k center dot p method for similar to 250000-atom nanostructure systems SO PHYSICAL REVIEW B LA English DT Article ID SILICON QUANTUM DOTS; ELECTRONIC-STRUCTURE; ALAS/GAAS SUPERLATTICES; EFFECTIVE-MASS; BAND-STRUCTURE; WIRES; APPROXIMATION; CONFINEMENT; STATES; ENERGY AB The electronic structure of quantum wells, wires, and dots is conventionally described by the envelope-function eight-band k . p method (the ''standard k . p model'') whereby coupling with bands other than the highest valence and lowest conduction bands is neglected. There is now accumulated evidence that coupling with other bands and a correct description of far-from-Gamma bulk states is crucial for quantitative modeling of nanostructure. While multiband generalization of the k . p exists for bulk solids, such approaches for nanostructures are rare. Starting with a pseudopotential plane-wave representation, we develop an efficient method for electronic-structure calculations of nanostructures in which (i) multiband coupling is included throughout the Brillouin zone and (ii) the underlying bulk band structure is described correctly even for far-from-Gamma states. A previously neglected interband overlap matrix now appears in the k . p formalism, permitting correct intervalley couplings. The method can be applied either using self-consistent potentials taken from ab initio calculations on prototype small systems or from the empirical pseudopotential method. Application to both short- and long-period (GaAs)(p)/(AlAs)(p) superlattices (SL) recovers (i) the bending down (''deconfinement'') of the <(Gamma)over bar(Gamma)> energy level of (001) SL at small periods p; (ii) the type-II-type-I crossover at p approximate to 8 SL, and (iii) the even-odd oscillation of the energies of the (R) over bar/<(X)over bar(L)> state of (001) SL and <(Gamma)over bar(L)> state of (111) SL. Introducing a few justified approximations, this method can be used to calculate the eigenstates of physical interest for large nanostructures. Application to spherical GaAs quantum dots embedded in an AlAs barrier (with similar to 250000 atoms) shows a type-II-type-I crossover for a dot diameter of 70 Angstrom, with an almost zero Gamma-X repulsion at the crossing point. Such a calculation takes less than 30 min on an IBM/6000 workstation model 590. C1 NATL RENEWABLE ENERGY LAB, GOLDEN, CO 80401 USA. RI Zunger, Alex/A-6733-2013 NR 41 TC 56 Z9 56 U1 2 U2 5 PU AMER PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 2469-9950 EI 2469-9969 J9 PHYS REV B JI Phys. Rev. B PD OCT 15 PY 1996 VL 54 IS 16 BP 11417 EP 11435 DI 10.1103/PhysRevB.54.11417 PG 19 WC Physics, Condensed Matter SC Physics GA VT675 UT WOS:A1996VT67500070 ER PT J AU Glutsch, S Chemla, DS Bechstedt, F AF Glutsch, S Chemla, DS Bechstedt, F TI Numerical calculation of the optical absorption in semiconductor quantum structures SO PHYSICAL REVIEW B LA English DT Article ID ELECTRONIC-STRUCTURE; EXCITON; SUPERLATTICES; SPECTRA; RESONANCES; STATES; ENERGY AB We describe a highly efficient, general-purpose, and easy-to-use method of calculating the optical absorption of semiconductor microstructures. The linear optical susceptibility is obtained by the numerical evaluation of the polarization in real space and real time, using finite differences and the leap-frog scheme. Numerical effort and storage scale as O(N), where N is the number of base elements. The algorithm is suitable for large-scale quantum systems. For illustration, we apply this method to quantum wells in a perpendicular magnetic field, Bat quantum dots, superlattices, coupled multiple quantum wells, and excitons on rough interfaces. C1 LAWRENCE BERKELEY LAB,DIV SCI MAT,BERKELEY,CA 94720. UNIV JENA,INST FESTKORPERTHEORIE & THEORET OPT,D-07743 JENA,GERMANY. RP Glutsch, S (reprint author), UNIV CALIF BERKELEY,DEPT PHYS,BERKELEY,CA 94720, USA. NR 33 TC 105 Z9 106 U1 1 U2 5 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 0163-1829 J9 PHYS REV B JI Phys. Rev. B PD OCT 15 PY 1996 VL 54 IS 16 BP 11592 EP 11601 DI 10.1103/PhysRevB.54.11592 PG 10 WC Physics, Condensed Matter SC Physics GA VT675 UT WOS:A1996VT67500087 ER PT J AU Maltez, RL Amaral, L Behar, M Vantomme, A Langouche, G Lin, XW AF Maltez, RL Amaral, L Behar, M Vantomme, A Langouche, G Lin, XW TI Mossbauer study of the magnetic character and ordering process of the cubic gamma-FeSi2 phase obtained by Fe implantation into a Si(100) matrix SO PHYSICAL REVIEW B LA English DT Article ID FESI2; SI AB The magnetic character and the ordering process of gamma-FeSi2 precipitates formed by Fe implantation into Si(100) followed by ion-beam epitaxial crystallization (IBIEC) have been studied using the Mossbauer technique. Measurements performed at 4 K have shown no evidence of magnetic interaction indicating that the gamma-FeSi2 phase is not of magnetic character. Conversely, conversion-electron Mossbauer experiments performed after the IBIEC procedure show basically the presence of a doublet, despite the cubic structure of the gamma-FeSi2 precipitates. However, after 1 h of annealing at 600 degrees C, a singlet, which before was barely recognizable, became more pronounced. The singlet-to-doublet proportion increases with increasing Fe concentration (2 at. %less than or equal to C-p less than or equal to 8.5 at. %), indicating that after annealing a better ordering in the gamma-FeSi2 precipitates is achieved. This ordering is obtained by an adequate combination of Fe-implanted concentration and thermal annealing. These studies have been complemented by Rutherford backscattering and/or channeling and transmission electron microscopy experiments. C1 CATHOLIC UNIV LEUVEN,INST KERN STRALINGSFYS,B-3001 LOUVAIN,BELGIUM. UNIV CALIF BERKELEY,LAWRENCE BERKELEY LAB,BERKELEY,CA 94720. RP Maltez, RL (reprint author), UNIV FED RIO GRANDE SUL,INST FIS,BR-90501970 PORTO ALEGRE,RS,BRAZIL. NR 17 TC 13 Z9 13 U1 0 U2 0 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 0163-1829 J9 PHYS REV B JI Phys. Rev. B PD OCT 15 PY 1996 VL 54 IS 16 BP 11659 EP 11665 DI 10.1103/PhysRevB.54.11659 PG 7 WC Physics, Condensed Matter SC Physics GA VT675 UT WOS:A1996VT67500094 ER PT J AU Cheng, BL Olinto, AV Schramm, DN Truran, JW AF Cheng, BL Olinto, AV Schramm, DN Truran, JW TI Constraints on the strength of primordial magnetic fields from big bang nucleosynthesis reexamined SO PHYSICAL REVIEW D LA English DT Article ID EARLY UNIVERSE; LIMITS AB In this paper, we reexamine in detail the effects of primordial magnetic fields on big bang nucleosynthesis (BBN) including a discussion of the magnetic field geometry and the anomalous magnetic moment. The presence of magnetic fields affects BBN by (1) increasing the weak reaction rates, (2) increasing the electron density due to changes to the electron phase space, and (3) increasing the expansion rate of the universe, due both to the magnetic field energy density and to the modified electron energy density. Of the effects considered, the increase in the expansion rate due to the magnetic field energy is the most significant for the interests of BBN. The allowed magnetic field intensity at the end of nucleosynthesis (0.01, MeV) is about 2 x 10(9) G and corresponds to an upper limit on the magnetic field energy density of about 28% of the neutrino energy density (rho(B) less than or equal to 0.28 rho(nu)). C1 UNIV CHICAGO,DEPT ASTRON & ASTROPHYS,CHICAGO,IL 60637. UNIV CHICAGO,ENRICO FERMI INST,CHICAGO,IL 60637. RP Cheng, BL (reprint author), LOS ALAMOS NATL LAB,NIS-2 MS D436,LOS ALAMOS,NM 87545, USA. NR 22 TC 65 Z9 65 U1 0 U2 0 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 0556-2821 J9 PHYS REV D JI Phys. Rev. D PD OCT 15 PY 1996 VL 54 IS 8 BP 4714 EP 4718 DI 10.1103/PhysRevD.54.4714 PG 5 WC Astronomy & Astrophysics; Physics, Particles & Fields SC Astronomy & Astrophysics; Physics GA VU994 UT WOS:A1996VU99400003 ER PT J AU Hawes, FT Williams, AG Roberts, CD AF Hawes, FT Williams, AG Roberts, CD TI Renormalization and chiral symmetry breaking in quenched QED in arbitrary covariant gauges SO PHYSICAL REVIEW D LA English DT Article ID SCHWINGER-DYSON EQUATION; QUANTUM ELECTRODYNAMICS; FERMION PROPAGATOR; ANALYTIC PROPERTIES; CONTINUUM-LIMIT; VERTEX FUNCTION; LANDAU GAUGE; MASS AB We extend a previous Landau-gauge study of subtractive renormalization of the fermion propagator Dyson-Schwinger equation in strong-coupling, quenched four-dimensional QED to arbitrary covariant gauges. We use the fermion-photon proper vertex proposed by Curtis and Pennington with an additional correction term included to compensate for the small gauge dependence induced by the ultraviolet regulator. We discuss the chiral limit and the onset of dynamical chiral symmetry breaking in the presence of nonperturbative renormalization. We extract the critical coupling in several different gauges and find evidence of a small residual gauge dependence in this quantity. C1 FLORIDA STATE UNIV,SUPERCOMP COMPUTAT RES INST,TALLAHASSEE,FL 32306. UNIV ADELAIDE,INST THEORET PHYS,ADELAIDE,SA 5005,AUSTRALIA. UNIV ADELAIDE,DEPT PHYS & MATH PHYS,ADELAIDE,SA 5005,AUSTRALIA. ARGONNE NATL LAB,DIV PHYS,ARGONNE,IL 60439. RP Hawes, FT (reprint author), FLORIDA STATE UNIV,DEPT PHYS,TALLAHASSEE,FL 32306, USA. RI Williams, Anthony/I-6698-2012; OI Roberts, Craig/0000-0002-2937-1361; Williams, Anthony/0000-0002-1472-1592 NR 43 TC 18 Z9 18 U1 0 U2 0 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 0556-2821 J9 PHYS REV D JI Phys. Rev. D PD OCT 15 PY 1996 VL 54 IS 8 BP 5361 EP 5372 DI 10.1103/PhysRevD.54.5361 PG 12 WC Astronomy & Astrophysics; Physics, Particles & Fields SC Astronomy & Astrophysics; Physics GA VU994 UT WOS:A1996VU99400068 ER PT J AU Shield, JE Kramer, MJ AF Shield, JE Kramer, MJ TI Dislocation analysis of deformed Al-Pd-Mn quasicrystals SO SCRIPTA MATERIALIA LA English DT Article ID BEAM ELECTRON-DIFFRACTION; ICOSAHEDRAL QUASI-CRYSTAL; CU-FE ALLOY; PLASTIC-DEFORMATION; BURGERS VECTOR AB Dislocation analysis was performed on polygrained Al70Pd21.5Mn8.5 icosahedral quasicrystals deformed at high temperature. Using contrast analysis, the Burgers vector was determined to be parallel to a twofold direction, while the line direction was found to be parallel to a different twofold direction. The angle between B and U was found to be 32 degrees so that the dislocation has mixed character. The screw component of the dislocation was found to be parallel to a twofold direction, while the edge component was found to be parallel to a pseudo twofold direction. Considering the characteristics of the dislocation, slip could occur on fivefold planes, resulting in 30 slip systems. C1 IOWA STATE UNIV,US DOE,AMES LAB,AMES,IA 50011. RP Shield, JE (reprint author), UNIV UTAH,DEPT MAT SCI & ENGN,SALT LAKE CITY,UT 84112, USA. NR 17 TC 2 Z9 2 U1 0 U2 0 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD, ENGLAND OX5 1GB SN 1359-6462 J9 SCRIPTA MATER JI Scr. Mater. PD OCT 15 PY 1996 VL 35 IS 8 BP 913 EP 918 DI 10.1016/1359-6462(96)00238-2 PG 6 WC Nanoscience & Nanotechnology; Materials Science, Multidisciplinary; Metallurgy & Metallurgical Engineering SC Science & Technology - Other Topics; Materials Science; Metallurgy & Metallurgical Engineering GA VG813 UT WOS:A1996VG81300002 ER PT J AU Huang, J Hsiung, LM Nieh, TG AF Huang, J Hsiung, LM Nieh, TG TI Effect of strain rate on the elevated-temperature tensile properties of an Al-Pb alloy SO SCRIPTA MATERIALIA LA English DT Article ID LIQUID-PHASE; CREEP; BEHAVIOR RP Huang, J (reprint author), LAWRENCE LIVERMORE NATL LAB,L-352,POB 808,LIVERMORE,CA 94551, USA. RI Nieh, Tai-Gang/G-5912-2011 OI Nieh, Tai-Gang/0000-0002-2814-3746 NR 10 TC 5 Z9 5 U1 0 U2 0 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD, ENGLAND OX5 1GB SN 1359-6462 J9 SCRIPTA MATER JI Scr. Mater. PD OCT 15 PY 1996 VL 35 IS 8 BP 919 EP 924 DI 10.1016/1359-6462(96)00257-6 PG 6 WC Nanoscience & Nanotechnology; Materials Science, Multidisciplinary; Metallurgy & Metallurgical Engineering SC Science & Technology - Other Topics; Materials Science; Metallurgy & Metallurgical Engineering GA VG813 UT WOS:A1996VG81300003 ER PT J AU Romano, LT Northrup, JE OKeefe, MA AF Romano, LT Northrup, JE OKeefe, MA TI Inversion domains in GaN grown on sapphire SO APPLIED PHYSICS LETTERS LA English DT Article ID MOLECULAR-BEAM EPITAXY; FILMS AB Planar defects observed in GaN films grown on (0001) sapphire have been identified as inversion domain boundaries (IDBs) by a combination of high resolution transmission electron microscopy, multiple dark field imaging, and convergent beam electron diffraction techniques. Films grown by molecular beam epitaxy (MBE), metalorganic vapor deposition (MOCVD), and hydride vapor phase epitaxy (HVPE) were investigated and all were found to contain IDBs. The IDBs in the MBE and HVPE films extended from the interface to the film surface and formed columnar domains that ranged in width from 3 to 20 nm in the MBE films and up to 100 nm in the HVPE films. For the films investigated, the MBE films had the highest density, and the MOCVD films had the lowest density of IDBs. The nucleation of inversion domains (IDs) may result from step-related inhomogeneities of the GaN/sapphire interface. (C) 1996 American Institute of Physics. C1 UNIV CALIF BERKELEY,LAWRENCE BERKELEY LAB,DIV MAT SCI,NATL CTR ELECTRON MICROSCOPY,BERKELEY,CA 94720. RP Romano, LT (reprint author), XEROX CORP,PALO ALTO RES CTR,3333 COYOTE HILL RD,PALO ALTO,CA 94304, USA. NR 20 TC 161 Z9 161 U1 3 U2 43 PU AMER INST PHYSICS PI WOODBURY PA CIRCULATION FULFILLMENT DIV, 500 SUNNYSIDE BLVD, WOODBURY, NY 11797-2999 SN 0003-6951 J9 APPL PHYS LETT JI Appl. Phys. Lett. PD OCT 14 PY 1996 VL 69 IS 16 BP 2394 EP 2396 DI 10.1063/1.117648 PG 3 WC Physics, Applied SC Physics GA VM317 UT WOS:A1996VM31700030 ER PT J AU Fullerton, EE Sowers, CH Pearson, JP Bader, SD Wu, XZ Lederman, D AF Fullerton, EE Sowers, CH Pearson, JP Bader, SD Wu, XZ Lederman, D TI A general approach to the epitaxial growth of rare-earth-transition-metal films SO APPLIED PHYSICS LETTERS LA English DT Article ID SPUTTERED FILMS; MAGNETIC-PROPERTIES; THIN-FILMS; SUPERLATTICES AB The growth of epitaxial rare-earth transition-metal thin films is reported by magnetron sputtering on single-crystal MgO substrates, The use of epitaxial W buffer layers demonstrates a general approach to control the phase and orientation of the films. Structure and magnetism results for SmFe12(001) on W(100) and magnetically hard Sm2Co7 (110) and (001) on W(100) and (110), respectively, are highlighted to illustrate the utility of the approach. (C) 1996 American Institute of Physics. C1 NO ILLINOIS UNIV,DEPT PHYS,DE KALB,IL 60115. ARGONNE NATL LAB,DIV MAT SCI,ARGONNE,IL 60439. W VIRGINIA UNIV,DEPT PHYS,MORGANTOWN,WV 26506. RP Fullerton, EE (reprint author), ARGONNE NATL LAB,DIV MAT SCI,9700 S CASS AVE,ARGONNE,IL 60439, USA. RI Bader, Samuel/A-2995-2013; Fullerton, Eric/H-8445-2013 OI Fullerton, Eric/0000-0002-4725-9509 NR 15 TC 48 Z9 48 U1 2 U2 14 PU AMER INST PHYSICS PI WOODBURY PA CIRCULATION FULFILLMENT DIV, 500 SUNNYSIDE BLVD, WOODBURY, NY 11797-2999 SN 0003-6951 J9 APPL PHYS LETT JI Appl. Phys. Lett. PD OCT 14 PY 1996 VL 69 IS 16 BP 2438 EP 2440 DI 10.1063/1.117663 PG 3 WC Physics, Applied SC Physics GA VM317 UT WOS:A1996VM31700045 ER PT J AU Gonis, A Turchi, PEA Kudrnovsky, J Drchal, V Turek, I AF Gonis, A Turchi, PEA Kudrnovsky, J Drchal, V Turek, I TI Reformulation of the Korringa-Kohn-Rostoker coherent potential approximation for the treatment of space-filling cell potentials and charge-transfer effects SO JOURNAL OF PHYSICS-CONDENSED MATTER LA English DT Article ID NON-MUFFIN-TIN; MULTIPLE-SCATTERING THEORY; ELECTRONIC-STRUCTURE; BAND THEORY; RANDOM ALLOYS; FORMULATION; EQUATIONS; SYSTEMS; SHAPE AB We present a reformulation of the Korringa-Kohn-Rostoker (KKR) coherent-potential approximation (CPA) which affords a number of conceptual and practical advantages over conventional formulations of the theory. In particular, as presented here the method can facilitate application to systems that cannot be described properly by a muffin-tin approximation to the cell potential and require a full potential treatment. Also, the formalism allows the derivation of the KKR CPA self-consistency condition within both a scattering matrix and a Green function approach, leading to uniquely defined species-resolved charge densities and densities of states. As shown in a companion paper, this formulation also allows the treatment of the so-called charge-transfer effects associated with Wigner-Seitz cells in an alloy which contain net amounts of charge. C1 ACAD SCI CZECH REPUBL,INST PHYS,CZ-18040 PRAGUE 8,CZECH REPUBLIC. ACAD SCI CZECH REPUBL,INST PHYS MAT,CZ-61662 BRNO,CZECH REPUBLIC. RP Gonis, A (reprint author), LAWRENCE LIVERMORE NATL LAB,DEPT CHEM & MAT SCI,L-268,LIVERMORE,CA 94550, USA. RI Turek, Ilja/G-5553-2014; KUDRNOVSKY, Josef/G-5581-2014; Drchal, Vaclav/G-6259-2014 OI KUDRNOVSKY, Josef/0000-0002-9968-6748; Drchal, Vaclav/0000-0002-6628-7417 NR 38 TC 8 Z9 8 U1 1 U2 2 PU IOP PUBLISHING LTD PI BRISTOL PA TECHNO HOUSE, REDCLIFFE WAY, BRISTOL, ENGLAND BS1 6NX SN 0953-8984 J9 J PHYS-CONDENS MAT JI J. Phys.-Condes. Matter PD OCT 14 PY 1996 VL 8 IS 42 BP 7869 EP 7881 DI 10.1088/0953-8984/8/42/007 PG 13 WC Physics, Condensed Matter SC Physics GA VN146 UT WOS:A1996VN14600007 ER PT J AU Gonis, A Turchi, PEA Kudrnovsky, J Drchal, V Turek, I AF Gonis, A Turchi, PEA Kudrnovsky, J Drchal, V Turek, I TI Charge-transfer effects in disordered alloys: The test case of Al-Li alloys SO JOURNAL OF PHYSICS-CONDENSED MATTER LA English DT Article ID COHERENT-POTENTIAL APPROXIMATION; RANDOM METALLIC ALLOYS; BAND-STRUCTURE METHODS; ELECTRONIC-STRUCTURE; TRANSITION; STABILITY; SURFACES; ENERGY AB A general method for treating the so-called charge-transfer effects in substitutional alloys is suggested within the formalism of the single-site (SS) coherent-potential approximation (CPA). The method allows the self-consistent treatment of the Poisson field through the construction of a configurational space and species-dependent structure constants which provide the means for an application of multiple-scattering theory which avoids overlap between adjacent cells. This, in rum, allows the treatment of non-neutral cells at the level of the SS CPA, avoiding the need for subsequent correction the results of the CPA. The method is compared with previous approaches to the problem and is used to treat the case of Al-Li alloys for which significant charge transfer is known to exist. The results are compared with those obtained within the muffin-tin implementation of the CPA, and a final discussion of the general features of the proposed method is given. C1 ACAD SCI CZECH REPUBL,INST PHYS,CZ-18040 PRAGUE 8,CZECH REPUBLIC. ACAD SCI CZECH REPUBL,INST PHYS MAT,CZ-61662 BRNO,CZECH REPUBLIC. RP Gonis, A (reprint author), LAWRENCE LIVERMORE NATL LAB,DEPT CHEM & MAT SCI,L-268,LIVERMORE,CA 94550, USA. RI Turek, Ilja/G-5553-2014; KUDRNOVSKY, Josef/G-5581-2014; Drchal, Vaclav/G-6259-2014 OI KUDRNOVSKY, Josef/0000-0002-9968-6748; Drchal, Vaclav/0000-0002-6628-7417 NR 26 TC 9 Z9 9 U1 0 U2 3 PU IOP PUBLISHING LTD PI BRISTOL PA TECHNO HOUSE, REDCLIFFE WAY, BRISTOL, ENGLAND BS1 6NX SN 0953-8984 J9 J PHYS-CONDENS MAT JI J. Phys.-Condes. Matter PD OCT 14 PY 1996 VL 8 IS 42 BP 7883 EP 7898 DI 10.1088/0953-8984/8/42/008 PG 16 WC Physics, Condensed Matter SC Physics GA VN146 UT WOS:A1996VN14600008 ER PT J AU Ooguri, H Oz, Y Yin, Z AF Ooguri, H Oz, Y Yin, Z TI D-branes on Calabi-Yau spaces and their mirrors SO NUCLEAR PHYSICS B LA English DT Article ID MODULI SPACE; MANIFOLDS; COMPACTIFICATIONS; GEOMETRY; DUALITY AB We study the boundary states of D-branes wrapped around supersymmetric cycles in a general Calabi-Yau manifold. In particular, we show how the geometric data on the cycles are encoded in the boundary states, As an application, we analyze how the minor symmetry transforms D-branes, and we verify that it is consistent with the conjectured periodicity and the monodromy of the Ramond-Ramond field configuration on a Calabi-Yau manifold. This also enables us to study open string worldsheet instanton corrections and relate them to closed string instanton counting. The cases when the mirror symmetry is realized as T-duality are also discussed. C1 UNIV CALIF BERKELEY,LAWRENCE BERKELEY LAB,THEORET PHYS GRP,BERKELEY,CA 94720. WEIZMANN INST SCI,DEPT PARTICLE PHYS,IL-76100 REHOVOT,ISRAEL. RP Ooguri, H (reprint author), UNIV CALIF BERKELEY,DEPT PHYS,366 LE CONTE HALL,BERKELEY,CA 94720, USA. RI Ooguri, Hirosi/A-4407-2011; OI Ooguri, Hirosi/0000-0001-6021-3778 NR 30 TC 224 Z9 224 U1 0 U2 0 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0550-3213 J9 NUCL PHYS B JI Nucl. Phys. B PD OCT 14 PY 1996 VL 477 IS 2 BP 407 EP 430 DI 10.1016/0550-3213(96)00379-3 PG 24 WC Physics, Particles & Fields SC Physics GA VK948 UT WOS:A1996VK94800004 ER PT J AU Ooguri, H Vafa, C AF Ooguri, H Vafa, C TI Summing up Dirichlet instantons SO PHYSICAL REVIEW LETTERS LA English DT Article ID STRING THEORY; MANIFOLDS AB We investigate quantum corrections to the moduli space for hypermultiplets for the type IIA string near a conifold singularity. We find a unique quantum deformation based on symmetry arguments which is consistent with a recent conjecture. The correction can be interpreted as an infinite sum coming from multiple wrappings of the Euclidean Dirichlet branes around the vanishing cycle. C1 UNIV CALIF BERKELEY,THEORET PHYS GRP,ERNEST ORLANDO LAWRENCE BERKELEY NATL LAB,BERKELEY,CA 94720. HARVARD UNIV,LYMAN LAB PHYS,CAMBRIDGE,MA 02138. RP Ooguri, H (reprint author), UNIV CALIF BERKELEY,DEPT PHYS,366 LE CONTE HALL,BERKELEY,CA 94720, USA. RI Ooguri, Hirosi/A-4407-2011; OI Ooguri, Hirosi/0000-0001-6021-3778 NR 14 TC 100 Z9 100 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 OCT 14 PY 1996 VL 77 IS 16 BP 3296 EP 3298 DI 10.1103/PhysRevLett.77.3296 PG 3 WC Physics, Multidisciplinary SC Physics GA VM032 UT WOS:A1996VM03200008 ER PT J AU Abachi, S Abbott, B Abolins, M Acharya, BS Adam, I Adams, L Adams, M Ahn, S Aihara, H Alitti, J Alvarez, G Alves, GA Amidi, E Amos, N Anderson, EW Aronson, SH Astur, R Avery, RE Baarmand, MM Baden, A Balamurali, V Balderston, J Baldin, B Banerjee, S Bantly, J Bartlett, JF Bazizi, K Bendich, J Beri, SB Bertram, I Bezzubov, VA Bhat, PC Bhatnagar, V Bhattacharjee, M Bischoff, A Biswas, N Blazey, G Blessing, S Bloom, P Boehnlein, A Bojko, NI Borcherding, F Borders, J Boswell, C Brandt, A Brock, R Bross, A Buchholz, D Burtovoi, VS Butler, JM Carvalho, W Casey, D CastillaValdez, H Chakraborty, D Chang, SM Chekulaev, SV Chen, LP Chen, W Choi, S Chopra, S Choudhary, BC Christenson, JH Chung, M Claes, D Clark, AR Cobau, WG Cochran, J Cooper, WE Cretsinger, C CullenVidal, D Cummings, MAC Cutts, D Dahl, OI De, K Demarteau, M Denisenko, N Denisov, D Denisov, SP Diehl, HT Diesburg, M DiLoreto, G Dixon, R Draper, P Drinkard, J Ducros, Y Dugad, SR Edmunds, D Ellison, J Elvira, VD Engelmann, R Eno, S Eppley, G Ermolov, P Eroshin, OV Evdokimov, VN Fahey, S Fahland, T Fatyga, M Fatyga, MK Featherly, J Feher, S Fein, D Ferbel, T Finocchiaro, G Fisk, HE Fisyak, Y Flattum, E Forden, GE Fortner, M Frame, KC Franzini, P Fuess, S Gallas, E Galyaev, AN Geld, TL Genik, RJ Genser, K Gerber, CE Gibbard, B Glebov, V Glenn, S Glicenstein, JF Gobbi, B Goforth, M Goldschmidt, A Gomez, B Gomez, G Goncharov, PI Solis, JLG Gordon, H Goss, LT Graf, N Grannis, PD Green, DR Green, J Greenlee, H Griffin, G Grossman, N Grudberg, P Grunendahl, S Gu, WX Guglielmo, G Guida, JA Guida, JM Guryn, W Gurzhiev, SN Gutierrez, P Gutnikov, YE Hadley, NJ Haggerty, H Hagopian, S Hagopian, V Hahn, KS Hall, RE Hansen, S Hatcher, R Hauptman, JM Hedin, D Heinson, AP Heintz, U HernandezMontoya, R Heuring, T Hirosky, R Hobbs, JD Hoeneisen, B Hoftun, JS Hsieh, F Hu, T Hu, T Hu, T Huehn, T Igarashi, S Ito, AS James, E Jaques, J Jerger, SA Jiang, JZY JoffeMinor, T Johari, H Johns, K Johnson, M Johnstad, H Jonckheere, A Jones, M Jostlein, H Jun, SY Jung, CK Kahn, S Kalbfleisch, G Kang, JS Kehoe, R Kelly, ML Kerth, L Kim, CL Kim, SK Klatchko, A Klima, B Klochkov, BI Klopfenstein, C Klyukhin, VI Kochetkov, VI Kohli, JM Koltick, D Kostritskiy, AV Kotcher, J Kourlas, J Kozelov, AV Kozlovski, EA Krishnaswamy, MR Krzywdzinski, S Kunori, S Lami, S Landsberg, G Lebrat, JF Leflat, A Li, H Li, J Li, YK LiDemarteau, QZ Lima, JGR Lincoln, D Linn, SL Linnemann, J Lipton, R Liu, YC Lobkowicz, F Loken, SC Lokos, S Lueking, L Lyon, AL Maciel, AKA Madaras, RJ Madden, R MaganaMendoza, L Mani, S Mao, HS Markeloff, R Markosky, L Marshall, T Martin, MI May, B Mayorov, AA McCarthy, R McKibben, T McKinley, J McMahon, T Melanson, HL deMello, JRT Merritt, KW Miettinen, H Mincer, A deMiranda, JM Mishra, CS Mokhov, N Mondal, NK Montgomery, HE Mooney, P deMotta, H Mudan, M Murphy, C Nang, F Narain, M Narasimham, VS Narayanan, A Neal, HA Negret, JP Neis, E Nemethy, P Nesic, D Nicola, M Norman, D Oesch, L Oguri, V Oltman, E Oshima, N Owen, D Padley, P Pang, M Para, A Park, CH Park, YM Partridge, R Parua, N Paterno, M Perkins, J Peryshkin, A Peters, M Piekarz, H Pischalnikov, Y Podstavkov, VM Pope, BG Prosper, HB Protopopescu, S Puseljic, D Qian, J Quintas, PZ Raja, R Rajagopalan, S Ramirez, O Rao, MVS Rapidis, PA Rasmussen, L Reucroft, S Rijssenbeek, M Rockwell, T Roe, NA Rubinov, P Ruchti, R Rutherford, J SanchezHernandez, A Santoro, A Sawyer, L Schamberger, RD Schellman, H Sculli, J Shabalina, E Shaffer, C Shankar, HC Shivpuri, RK Shupe, M Singh, JB Sirotenko, V Smart, W Smith, A Smith, RP Snihur, R Snow, J Snyder, S Solomon, J Sood, PM Sosebee, M Souza, M Spadafora, ML Stephens, RW Stevenson, ML Stewart, D Stoianova, DA Stoker, D Streets, K Strovink, M Sznajder, A Tamburello, P Tarazi, J Tartaglia, M Taylor, TL Thompson, J Trippe, TG Tuts, PM Varelas, N Varnes, EW Virador, PRG Vititoe, D Volkov, AA Vorobiev, AP Wahl, HD Wang, G Warchol, J Watts, G Wayne, M Weerts, H White, A White, JT Wightman, JA Wilcox, J Willis, S Wimpenny, SJ Wirjawan, JVD Womeraley, 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 Abachi, S Abbott, B Abolins, M Acharya, BS Adam, I Adams, L Adams, M Ahn, S Aihara, H Alitti, J Alvarez, G Alves, GA Amidi, E Amos, N Anderson, EW Aronson, SH Astur, R Avery, RE Baarmand, MM Baden, A Balamurali, V Balderston, J Baldin, B Banerjee, S Bantly, J Bartlett, JF Bazizi, K Bendich, J Beri, SB Bertram, I Bezzubov, VA Bhat, PC Bhatnagar, V Bhattacharjee, M Bischoff, A Biswas, N Blazey, G Blessing, S Bloom, P Boehnlein, A Bojko, NI Borcherding, F Borders, J Boswell, C Brandt, A Brock, R Bross, A Buchholz, D Burtovoi, VS Butler, JM Carvalho, W Casey, D CastillaValdez, H Chakraborty, D Chang, SM Chekulaev, SV Chen, LP Chen, W Choi, S Chopra, S Choudhary, BC Christenson, JH Chung, M Claes, D Clark, AR Cobau, WG Cochran, J Cooper, WE Cretsinger, C CullenVidal, D Cummings, MAC Cutts, D Dahl, OI De, K Demarteau, M Denisenko, N Denisov, D Denisov, SP Diehl, HT Diesburg, M DiLoreto, G Dixon, R Draper, P Drinkard, J Ducros, Y Dugad, SR Edmunds, D Ellison, J Elvira, VD Engelmann, R Eno, S Eppley, G Ermolov, P Eroshin, OV Evdokimov, VN Fahey, S Fahland, T Fatyga, M Fatyga, MK Featherly, J Feher, S Fein, D Ferbel, T Finocchiaro, G Fisk, HE Fisyak, Y Flattum, E Forden, GE Fortner, M Frame, KC Franzini, P Fuess, S Gallas, E Galyaev, AN Geld, TL Genik, RJ Genser, K Gerber, CE Gibbard, B Glebov, V Glenn, S Glicenstein, JF Gobbi, B Goforth, M Goldschmidt, A Gomez, B Gomez, G Goncharov, PI Solis, JLG Gordon, H Goss, LT Graf, N Grannis, PD Green, DR Green, J Greenlee, H Griffin, G Grossman, N Grudberg, P Grunendahl, S Gu, WX Guglielmo, G Guida, JA Guida, JM Guryn, W Gurzhiev, SN Gutierrez, P Gutnikov, YE Hadley, NJ Haggerty, H Hagopian, S Hagopian, V Hahn, KS Hall, RE Hansen, S Hatcher, R Hauptman, JM Hedin, D Heinson, AP Heintz, U HernandezMontoya, R Heuring, T Hirosky, R Hobbs, JD Hoeneisen, B Hoftun, JS Hsieh, F Hu, T Hu, T Hu, T Huehn, T Igarashi, S Ito, AS James, E Jaques, J Jerger, SA Jiang, JZY JoffeMinor, T Johari, H Johns, K Johnson, M Johnstad, H Jonckheere, A Jones, M Jostlein, H Jun, SY Jung, CK Kahn, S Kalbfleisch, G Kang, JS Kehoe, R Kelly, ML Kerth, L Kim, CL Kim, SK Klatchko, A Klima, B Klochkov, BI Klopfenstein, C Klyukhin, VI Kochetkov, VI Kohli, JM Koltick, D Kostritskiy, AV Kotcher, J Kourlas, J Kozelov, AV Kozlovski, EA Krishnaswamy, MR Krzywdzinski, S Kunori, S Lami, S Landsberg, G Lebrat, JF Leflat, A Li, H Li, J Li, YK LiDemarteau, QZ Lima, JGR Lincoln, D Linn, SL Linnemann, J Lipton, R Liu, YC Lobkowicz, F Loken, SC Lokos, S Lueking, L Lyon, AL Maciel, AKA Madaras, RJ Madden, R MaganaMendoza, L Mani, S Mao, HS Markeloff, R Markosky, L Marshall, T Martin, MI May, B Mayorov, AA McCarthy, R McKibben, T McKinley, J McMahon, T Melanson, HL deMello, JRT Merritt, KW Miettinen, H Mincer, A deMiranda, JM Mishra, CS Mokhov, N Mondal, NK Montgomery, HE Mooney, P deMotta, H Mudan, M Murphy, C Nang, F Narain, M Narasimham, VS Narayanan, A Neal, HA Negret, JP Neis, E Nemethy, P Nesic, D Nicola, M Norman, D Oesch, L Oguri, V Oltman, E Oshima, N Owen, D Padley, P Pang, M Para, A Park, CH Park, YM Partridge, R Parua, N Paterno, M Perkins, J Peryshkin, A Peters, M Piekarz, H Pischalnikov, Y Podstavkov, VM Pope, BG Prosper, HB Protopopescu, S Puseljic, D Qian, J Quintas, PZ Raja, R Rajagopalan, S Ramirez, O Rao, MVS Rapidis, PA Rasmussen, L Reucroft, S Rijssenbeek, M Rockwell, T Roe, NA Rubinov, P Ruchti, R Rutherford, J SanchezHernandez, A Santoro, A Sawyer, L Schamberger, RD Schellman, H Sculli, J Shabalina, E Shaffer, C Shankar, HC Shivpuri, RK Shupe, M Singh, JB Sirotenko, V Smart, W Smith, A Smith, RP Snihur, R Snow, J Snyder, S Solomon, J Sood, PM Sosebee, M Souza, M Spadafora, ML Stephens, RW Stevenson, ML Stewart, D Stoianova, DA Stoker, D Streets, K Strovink, M Sznajder, A Tamburello, P Tarazi, J Tartaglia, M Taylor, TL Thompson, J Trippe, TG Tuts, PM Varelas, N Varnes, EW Virador, PRG Vititoe, D Volkov, AA Vorobiev, AP Wahl, HD Wang, G Warchol, J Watts, G Wayne, M Weerts, H White, A White, JT Wightman, JA Wilcox, J Willis, S Wimpenny, SJ Wirjawan, JVD Womeraley, 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 Search for anomalous WW and WZ production in p(p)over-bar collisions at root s=1.8 TeV SO PHYSICAL REVIEW LETTERS LA English DT Article ID BOSON SECTOR; COUPLINGS AB We present results from a search for anomalous WW and WZ production in collisions root s = 1.8 TeV. We used --> e nu jjX events observed during the 1992-1993 run of the Fermilab Tevatron collider, corresponding to an integrated luminosity of 13.7 +/- 0.7 pb(-1). A fit to the transverse momentum spectrum of the W boson yields direct limits on the CP-conserving anomalous WW gamma and WWZ coupling parameters of -0.9 < Delta kappa < 1.1 (with lambda = 0) and -0.6 < lambda < 0.7 (with Delta kappa = 0) at the 95% confidence level, for a form factor scale Lambda = 1.5 TeV, assuming that the WW gamma and WWZ coupling parameters are equal. C1 UNIV LOS ANDES,BOGOTA,COLOMBIA. UNIV ARIZONA,TUCSON,AZ 85721. BOSTON UNIV,BOSTON,MA 02215. BROOKHAVEN NATL LAB,UPTON,NY 11973. BROWN UNIV,PROVIDENCE,RI 02912. UNIV BUENOS AIRES,BUENOS AIRES,DF,ARGENTINA. UNIV CALIF DAVIS,DAVIS,CA 95616. UNIV CALIF IRVINE,IRVINE,CA 92717. UNIV CALIF RIVERSIDE,RIVERSIDE,CA 92521. CTR BRASILEIRO PESQUISAS FIS,LAFEX,RIO JANEIRO,BRAZIL. CINVESTAV IPN,MEXICO CITY,DF,MEXICO. COLUMBIA UNIV,NEW YORK,NY 10027. UNIV DELHI,DELHI 110007,INDIA. FLORIDA STATE UNIV,TALLAHASSEE,FL 32306. UNIV HAWAII,HONOLULU,HI 96822. UNIV ILLINOIS,CHICAGO,IL 60607. INDIANA UNIV,BLOOMINGTON,IN 47405. IOWA STATE UNIV SCI & TECHNOL,AMES,IA 50011. KOREA UNIV,SEOUL,SOUTH KOREA. KYUNGSUNG UNIV,PUSAN 608736,SOUTH KOREA. UNIV CALIF BERKELEY,LAWRENCE BERKELEY LAB,BERKELEY,CA 94720. UNIV MARYLAND,COLLEGE PK,MD 20742. UNIV MICHIGAN,ANN ARBOR,MI 48109. MICHIGAN STATE UNIV,E LANSING,MI 48824. MOSCOW MV LOMONOSOV STATE UNIV,MOSCOW,RUSSIA. UNIV NEBRASKA,LINCOLN,NE 68588. NYU,NEW YORK,NY 10003. NORTHEASTERN UNIV,BOSTON,MA 02115. NO ILLINOIS UNIV,DE KALB,IL 60115. NORTHWESTERN UNIV,EVANSTON,IL 60208. UNIV NOTRE DAME,NOTRE DAME,IN 46556. UNIV OKLAHOMA,NORMAN,OK 73019. PANJAB UNIV,CHANDIGARH 160014,INDIA. INST HIGH ENERGY PHYS,PROTVINO 142284,RUSSIA. PURDUE UNIV,W LAFAYETTE,IN 47907. RICE UNIV,HOUSTON,TX 77251. UNIV ESTADUAL RIO JANEIRO,RIO JANEIRO,BRAZIL. UNIV ROCHESTER,ROCHESTER,NY 14627. CEA,DAPNIA,SERV PHYS PARTICULARS,CTR ETUD SACLAY,GIF SUR YVETTE,FRANCE. SEOUL NATL UNIV,SEOUL,SOUTH KOREA. SUNY STONY BROOK,STONY BROOK,NY 11794. TATA INST FUNDAMENTAL RES,BOMBAY 400005,MAHARASHTRA,INDIA. UNIV TEXAS,ARLINGTON,TX 76019. TEXAS A&M UNIV,COLLEGE STN,TX 77843. RP Abachi, S (reprint author), FERMILAB NATL ACCELERATOR LAB,POB 500,BATAVIA,IL 60510, USA. RI Shivpuri, R K/A-5848-2010; Gutierrez, Phillip/C-1161-2011; Leflat, Alexander/D-7284-2012; Klyukhin, Vyacheslav/D-6850-2012; De, Kaushik/N-1953-2013; Oguri, Vitor/B-5403-2013; Alves, Gilvan/C-4007-2013; Kim, Sun Kee/G-2042-2015; Chekulaev, Sergey/O-1145-2015; de Mello Neto, Joao/C-5822-2013; Sznajder, Andre/L-1621-2016; Aihara, Hiroaki/F-3854-2010 OI Klyukhin, Vyacheslav/0000-0002-8577-6531; De, Kaushik/0000-0002-5647-4489; Kim, Sun Kee/0000-0002-0013-0775; de Mello Neto, Joao/0000-0002-3234-6634; Sznajder, Andre/0000-0001-6998-1108; Aihara, Hiroaki/0000-0002-1907-5964 NR 18 TC 33 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 OCT 14 PY 1996 VL 77 IS 16 BP 3303 EP 3308 DI 10.1103/PhysRevLett.77.3303 PG 6 WC Physics, Multidisciplinary SC Physics GA VM032 UT WOS:A1996VM03200010 ER PT J AU Abachi, S Abbott, B Abolins, M Acharya, BS Adam, I Adams, DL Adams, M Ahn, S Aihara, H Alitti, J Alvarez, G Alves, GA Amidi, E Amos, N Anderson, EW Aronson, SH Astur, R Avery, RE Baarmand, MM Baden, A Balamurali, V Balderston, J Baldin, B Banerjee, S Bantly, J Bartlett, JF Bazizi, K Belyaev, A Bendich, J Beri, SB Bertram, I Bezzubov, VA Bhat, PC Bhatnagar, V Bhattacharjee, M Bischoff, A Biswas, N Blazey, G Blessing, S Bloom, P Boehnlein, A Bojko, NI Borcherding, F Borders, J Boswell, C Brandt, A Brock, R Bross, A Buchholz, D Burtovoi, VS Butler, JM Carvalho, W Casey, D CastillaValdez, H Chakraborty, D Chang, SM Chekulaev, SV Chen, LP Chen, W Choi, S Chopra, S Choudhary, BC Christenson, JH Chung, M Claes, D Clark, AR Cobau, WG Cochran, J Cooper, WE Cretsinger, C CullenVidal, D Cummings, MAC Cutts, D Dahl, OI De, K Demarteau, M Denisenko, N Denisov, D Denisov, SP Diehl, HT Diesburg, M DiLoreto, G Dixon, R Draper, P Drinkard, J Ducros, Y Dudko, LV Dugad, SR Edmunds, D Ellison, J Elvira, VD Engelmann, R Eno, S Eppley, G Ermolov, P Eroshin, OV Evdokimov, VN Fahey, S Fahland, T Fatyga, M Fatyga, MK Featherly, J Feher, S Fein, D Ferbel, T Finocchiaro, G Fisk, HE Fisyak, Y Flattum, E Forden, GE Fortner, M Frame, KC Franzini, P Fuess, S Gallas, E Galyaev, AN Geld, TL Genik, RJ Genser, K Gerber, CE Gibbard, B Glebov, V Glenn, S Glicenstein, JF Gobbi, B Goforth, M Goldschmidt, A Gomez, B Gomez, G Goncharov, PI Solis, JLG Gordon, H Goss, LT Graf, N Grannis, PD Green, DR Green, J Greenlee, H Griffin, G Grossman, N Grudberg, P Grunendahl, S Gu, WX Guglielmo, G Guida, JA Guida, JM Guryn, W Gurzhiev, SN Gutierrez, P Gutnikov, YE Hadley, NJ Haggerty, H Hagopian, S Hagopian, V Hahn, KS Hall, RE Hansen, S Hatcher, R Hauptman, JM Hedin, D Heinson, AP Heintz, U HernandezMontoya, R Heuring, T Hirosky, R Hobbs, JD Hoeneisen, B Hoftun, JS Hsieh, F Hu, T Hu, T Hu, T Huehn, T Igarashi, S Ito, AS James, E Jaques, J Jerger, SA Jiang, ZY JoffeMinor, T Johari, H Johns, K Johnson, M Johnstad, H Jonckheere, A Jones, M Jostlein, H Jun, SY Jung, CK Kahn, S Kalbfleisch, G Kang, JS Kehoe, R Kelly, ML Kerth, L Kim, CL Kim, SK Klatchko, A Klima, B Klochkov, BI Klopfenstein, C Klyukhin, VI Kochetkov, VI Kohli, JM Koltick, D Kostritskiy, AV Kotcher, J Kourlas, J Kozelov, AV Kozlovski, EA Krane, J Krishnaswamy, MR Krzywdzinski, S Kunori, S Lami, S Landsberg, G Lauer, B Lebrat, JF Leflat, A Li, H Li, J Li, YK LiDemarteau, QZ Lima, JGR Lincoln, D Linn, SL Linnemann, J Lipton, R Liu, YC Lobkowicz, F Loken, SC Lokos, S Lueking, L Lyon, AL Maciel, AKA Madaras, RJ Madden, R MaganaMendoza, L Mani, S Mao, HS Markeloff, R Markosky, L Marshall, T Martin, MI May, B Mayorov, AA McCarthy, R McKibben, T McKinley, J McMahon, T Melanson, HL deMello, JRT Merritt, KW Miettinen, H Mincer, A deMiranda, JM Mishra, CS Mokhov, N Mondal, NK Montgomery, HE Mooney, P daMotta, H Mudan, M Murphy, C Nang, F Narain, M Narasimham, VS Narayanan, A Neal, HA Negret, JP Neis, E Nemethy, P Nesic, D Nicola, M Norman, D Oesch, L Oguri, V Oltman, E Oshima, N Owen, D Padley, P Pang, M Para, A Park, CH Park, YM Partridge, R Parua, N Paterno, M Perkins, J Peryshkin, A Peters, M Piekarz, H Pischalnikov, Y Podstavkov, VM Pope, BG Prosper, HB Protopopescu, S Puseljic, D Qian, J Quintas, PZ Raja, R Rajagopalan, S Ramirez, O Rao, MVS Rapidis, PA Rasmussen, L Reucroft, S Rijssenbeek, M Rockwell, T Roe, NA Rubinov, P Ruchti, R Rutherfoord, J SanchezHernandez, A Santoro, A Sawyer, L Schamberger, RD Schellman, H Sculli, J Shabalina, E Shaffer, C Shankar, HC Shivpuri, RK Shupe, M Singh, JB Sirotenko, V Smart, W Smith, A Smith, RP Snihur, R Snow, GR Snow, J Snyder, S Solomon, J Sood, PM Sosebee, M Sotnikova, N Souza, M Spadafora, AL Stephens, RW Stevenson, ML Stewart, D Stoianova, DA Stoker, D Streets, K Strovink, M Sznajder, A Tamburello, P Tarazi, J Tartaglia, M Taylor, TL Thompson, J Trippe, TG Tuts, PM Varelas, N Varnes, EW Virador, PRG Vititoe, D Volkov, AA Vorobiev, AP Wahl, HD Wang, G Warchol, J Watts, G Wayne, M Weerts, H White, A White, JT Wightman, JA Wilcox, J Willis, S Wimpenny, SJ Wirjawan, JVD Womersley, J Won, E Wood, DR Xu, H Yamada, R Yamin, P Yanagisawa, C Yang, J Yasuda, T Yepes, P Yoshikawa, C Youssef, S Yu, J Yu, Y Zhu, Q Zhu, ZH Zieminska, D Zieminski, A Zverev, EG Zylberstejn, A AF Abachi, S Abbott, B Abolins, M Acharya, BS Adam, I Adams, DL Adams, M Ahn, S Aihara, H Alitti, J Alvarez, G Alves, GA Amidi, E Amos, N Anderson, EW Aronson, SH Astur, R Avery, RE Baarmand, MM Baden, A Balamurali, V Balderston, J Baldin, B Banerjee, S Bantly, J Bartlett, JF Bazizi, K Belyaev, A Bendich, J Beri, SB Bertram, I Bezzubov, VA Bhat, PC Bhatnagar, V Bhattacharjee, M Bischoff, A Biswas, N Blazey, G Blessing, S Bloom, P Boehnlein, A Bojko, NI Borcherding, F Borders, J Boswell, C Brandt, A Brock, R Bross, A Buchholz, D Burtovoi, VS Butler, JM Carvalho, W Casey, D CastillaValdez, H Chakraborty, D Chang, SM Chekulaev, SV Chen, LP Chen, W Choi, S Chopra, S Choudhary, BC Christenson, JH Chung, M Claes, D Clark, AR Cobau, WG Cochran, J Cooper, WE Cretsinger, C CullenVidal, D Cummings, MAC Cutts, D Dahl, OI De, K Demarteau, M Denisenko, N Denisov, D Denisov, SP Diehl, HT Diesburg, M DiLoreto, G Dixon, R Draper, P Drinkard, J Ducros, Y Dudko, LV Dugad, SR Edmunds, D Ellison, J Elvira, VD Engelmann, R Eno, S Eppley, G Ermolov, P Eroshin, OV Evdokimov, VN Fahey, S Fahland, T Fatyga, M Fatyga, MK Featherly, J Feher, S Fein, D Ferbel, T Finocchiaro, G Fisk, HE Fisyak, Y Flattum, E Forden, GE Fortner, M Frame, KC Franzini, P Fuess, S Gallas, E Galyaev, AN Geld, TL Genik, RJ Genser, K Gerber, CE Gibbard, B Glebov, V Glenn, S Glicenstein, JF Gobbi, B Goforth, M Goldschmidt, A Gomez, B Gomez, G Goncharov, PI Solis, JLG Gordon, H Goss, LT Graf, N Grannis, PD Green, DR Green, J Greenlee, H Griffin, G Grossman, N Grudberg, P Grunendahl, S Gu, WX Guglielmo, G Guida, JA Guida, JM Guryn, W Gurzhiev, SN Gutierrez, P Gutnikov, YE Hadley, NJ Haggerty, H Hagopian, S Hagopian, V Hahn, KS Hall, RE Hansen, S Hatcher, R Hauptman, JM Hedin, D Heinson, AP Heintz, U HernandezMontoya, R Heuring, T Hirosky, R Hobbs, JD Hoeneisen, B Hoftun, JS Hsieh, F Hu, T Hu, T Hu, T Huehn, T Igarashi, S Ito, AS James, E Jaques, J Jerger, SA Jiang, ZY JoffeMinor, T Johari, H Johns, K Johnson, M Johnstad, H Jonckheere, A Jones, M Jostlein, H Jun, SY Jung, CK Kahn, S Kalbfleisch, G Kang, JS Kehoe, R Kelly, ML Kerth, L Kim, CL Kim, SK Klatchko, A Klima, B Klochkov, BI Klopfenstein, C Klyukhin, VI Kochetkov, VI Kohli, JM Koltick, D Kostritskiy, AV Kotcher, J Kourlas, J Kozelov, AV Kozlovski, EA Krane, J Krishnaswamy, MR Krzywdzinski, S Kunori, S Lami, S Landsberg, G Lauer, B Lebrat, JF Leflat, A Li, H Li, J Li, YK LiDemarteau, QZ Lima, JGR Lincoln, D Linn, SL Linnemann, J Lipton, R Liu, YC Lobkowicz, F Loken, SC Lokos, S Lueking, L Lyon, AL Maciel, AKA Madaras, RJ Madden, R MaganaMendoza, L Mani, S Mao, HS Markeloff, R Markosky, L Marshall, T Martin, MI May, B Mayorov, AA McCarthy, R McKibben, T McKinley, J McMahon, T Melanson, HL deMello, JRT Merritt, KW Miettinen, H Mincer, A deMiranda, JM Mishra, CS Mokhov, N Mondal, NK Montgomery, HE Mooney, P daMotta, H Mudan, M Murphy, C Nang, F Narain, M Narasimham, VS Narayanan, A Neal, HA Negret, JP Neis, E Nemethy, P Nesic, D Nicola, M Norman, D Oesch, L Oguri, V Oltman, E Oshima, N Owen, D Padley, P Pang, M Para, A Park, CH Park, YM Partridge, R Parua, N Paterno, M Perkins, J Peryshkin, A Peters, M Piekarz, H Pischalnikov, Y Podstavkov, VM Pope, BG Prosper, HB Protopopescu, S Puseljic, D Qian, J Quintas, PZ Raja, R Rajagopalan, S Ramirez, O Rao, MVS Rapidis, PA Rasmussen, L Reucroft, S Rijssenbeek, M Rockwell, T Roe, NA Rubinov, P Ruchti, R Rutherfoord, J SanchezHernandez, A Santoro, A Sawyer, L Schamberger, RD Schellman, H Sculli, J Shabalina, E Shaffer, C Shankar, HC Shivpuri, RK Shupe, M Singh, JB Sirotenko, V Smart, W Smith, A Smith, RP Snihur, R Snow, GR Snow, J Snyder, S Solomon, J Sood, PM Sosebee, M Sotnikova, N Souza, M Spadafora, AL Stephens, RW Stevenson, ML Stewart, D Stoianova, DA Stoker, D Streets, K Strovink, M Sznajder, A Tamburello, P Tarazi, J Tartaglia, M Taylor, TL Thompson, J Trippe, TG Tuts, PM Varelas, N Varnes, EW Virador, PRG Vititoe, D Volkov, AA Vorobiev, AP Wahl, HD Wang, G Warchol, J Watts, G Wayne, M Weerts, H White, A White, JT Wightman, JA Wilcox, J Willis, S Wimpenny, SJ Wirjawan, JVD Womersley, J Won, E Wood, DR Xu, H Yamada, R Yamin, P Yanagisawa, C Yang, J Yasuda, T Yepes, P Yoshikawa, C Youssef, S Yu, J Yu, Y Zhu, Q Zhu, ZH Zieminska, D Zieminski, A Zverev, EG Zylberstejn, A TI Measurement of the W boson mass SO PHYSICAL REVIEW LETTERS LA English DT Article ID PARTON DISTRIBUTIONS; P(P)OVER-BAR COLLISIONS; ROOT-S=1.8 TEV AB A measurement of the mass of the W boson is presented based on a sample of 5982 W --> e nu decays observed in collisions at root s = 1.8 TeV with the D0 detector during the 1992-1993 run. From a fit to the transverse mass spectrum, combined with measurements of the Z boson mass, the W boson mass is measured to be M(W) = 80.350 +/- 0.140(stat) +/- 0.165(syst) +/- 0.160(scale) GeV/c(2). C1 UNIV LOS ANDES,BOGOTA,COLOMBIA. UNIV ARIZONA,TUCSON,AZ 85721. BOSTON UNIV,BOSTON,MA 02215. BROOKHAVEN NATL LAB,UPTON,NY 11973. BROWN UNIV,PROVIDENCE,RI 02912. UNIV BUENOS AIRES,BUENOS AIRES,DF,ARGENTINA. UNIV CALIF DAVIS,DAVIS,CA 95616. UNIV CALIF IRVINE,IRVINE,CA 92717. UNIV CALIF RIVERSIDE,RIVERSIDE,CA 92717. CTR BRASILEIRO PESQUISAS FIS,LAFEX,RIO JANEIRO,BRAZIL. CTR INVEST & ESTUDIOS AVANZADOS,MEXICO CITY,DF,MEXICO. COLUMBIA UNIV,NEW YORK,NY 10027. UNIV DELHI,DELHI 110007,INDIA. FLORIDA STATE UNIV,TALLAHASSEE,FL 32306. UNIV HAWAII,HONOLULU,HI 96822. UNIV ILLINOIS,CHICAGO,IL 60607. INDIANA UNIV,BLOOMINGTON,IN 47405. IOWA STATE UNIV SCI & TECHNOL,AMES,IA 50011. KOREA UNIV,SEOUL 136701,SOUTH KOREA. KYUNGSUNG UNIV,PUSAN,SOUTH KOREA. UNIV CALIF BERKELEY,LAWRENCE BERKELEY LAB,BERKELEY,CA 94720. UNIV MARYLAND,COLLEGE PK,MD 20742. UNIV MICHIGAN,ANN ARBOR,MI 48109. MICHIGAN STATE UNIV,E LANSING,MI 48824. MOSCOW MV LOMONOSOV STATE UNIV,MOSCOW,RUSSIA. UNIV NEBRASKA,LINCOLN,NE 68588. NYU,NEW YORK,NY 10003. NORTHEASTERN UNIV,BOSTON,MA 02115. NO ILLINOIS UNIV,DE KALB,IL 60115. NORTHWESTERN UNIV,EVANSTON,IL 60208. UNIV NOTRE DAME,NOTRE DAME,IN 46556. UNIV OKLAHOMA,NORMAN,OK 73019. PANJAB UNIV,CHANDIGARH 160014,INDIA. INST HIGH ENERGY PHYS,PROTVINO 142284,RUSSIA. PURDUE UNIV,W LAFAYETTE,IN 47907. RICE UNIV,HOUSTON,TX 77251. UNIV ESTADUAL RIO JANEIRO,RIO JANEIRO,BRAZIL. UNIV ROCHESTER,ROCHESTER,NY 14627. CEA,DEPT ASTROPHYS PHYS PARTICULES PHYS NUCL & INSTRU,SERV PHYS PARTICULARS,CE SACLAY,GIF SUR YVETTE,FRANCE. SEOUL NATL UNIV,SEOUL,SOUTH KOREA. SUNY STONY BROOK,STONY BROOK,NY 11794. TATA INST FUNDAMENTAL RES,BOMBAY 400005,MAHARASHTRA,INDIA. UNIV TEXAS,ARLINGTON,TX 76019. TEXAS A&M UNIV,COLLEGE STN,TX 77843. RP Abachi, S (reprint author), FERMILAB NATL ACCELERATOR LAB,POB 500,BATAVIA,IL 60510, USA. RI Aihara, Hiroaki/F-3854-2010; Shivpuri, R K/A-5848-2010; Gutierrez, Phillip/C-1161-2011; Dudko, Lev/D-7127-2012; Leflat, Alexander/D-7284-2012; 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; Chekulaev, Sergey/O-1145-2015; de Mello Neto, Joao/C-5822-2013; 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; de Mello Neto, Joao/0000-0002-3234-6634; Sznajder, Andre/0000-0001-6998-1108; Baarmand, Marc/0000-0002-9792-8619 NR 22 TC 56 Z9 56 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 OCT 14 PY 1996 VL 77 IS 16 BP 3309 EP 3314 DI 10.1103/PhysRevLett.77.3309 PG 6 WC Physics, Multidisciplinary SC Physics GA VM032 UT WOS:A1996VM03200011 ER PT J AU Price, DL Wills, JM Cooper, BR AF Price, DL Wills, JM Cooper, BR TI TiC(001) surface relaxation SO PHYSICAL REVIEW LETTERS LA English DT Article ID ENERGY ION-SCATTERING; RIPPLED RELAXATION; NIAL(110) SURFACE; LATTICE-RELAXATION; METAL-SURFACES; TIN; CRYSTAL AB The rippled relaxation of the TiC(001) surface is examined, using a full-potential linear muffin tin orbital electronic structure calculation. We investigate the underlying physics of the relaxation in a manner which forms a close correspondence with historically important, analytic models of surface relaxation, and compare to previously calculated results for TaC. Unlike a recently reported tight-binding model, our calculations for TiC predict outward relaxation for the surface carbon, and inward relaxation for titanium, which, while reduced in magnitude, is the same direction of relaxation found in TaC. C1 LOS ALAMOS NATL LAB,LOS ALAMOS,NM 87545. W VIRGINIA UNIV,DEPT PHYS,MORGANTOWN,WV 26506. RP Price, DL (reprint author), UNIV MEMPHIS,DEPT PHYS,MEMPHIS,TN 38152, USA. NR 19 TC 33 Z9 33 U1 0 U2 3 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 0031-9007 J9 PHYS REV LETT JI Phys. Rev. Lett. PD OCT 14 PY 1996 VL 77 IS 16 BP 3375 EP 3378 DI 10.1103/PhysRevLett.77.3375 PG 4 WC Physics, Multidisciplinary SC Physics GA VM032 UT WOS:A1996VM03200027 ER PT J AU Fiske, PS AF Fiske, PS TI An open letter to frustrated scientists looking for a job: There is hope SO SCIENTIST LA English DT Editorial Material AB Rethinking the job market: The prospects for a research career may look grim, but there are options for young scientists, according to Peter Fiske, a geophysicist from Lawrence Livermore National Laboratory, who points out that the skills needed to survive graduate school have a high market value. C1 US DEPT DEF,WASHINGTON,DC 20305. RP Fiske, PS (reprint author), LAWRENCE LIVERMORE NATL LAB,LIVERMORE,CA 94550, USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU SCIENTIST INC PI PHILADELPHIA PA 3600 MARKET ST SUITE 450, PHILADELPHIA, PA 19104 SN 0890-3670 J9 SCIENTIST JI Scientist PD OCT 14 PY 1996 VL 10 IS 20 BP 10 EP 10 PG 1 WC Information Science & Library Science; Multidisciplinary Sciences SC Information Science & Library Science; Science & Technology - Other Topics GA VL938 UT WOS:A1996VL93800006 ER PT J AU Loehle, C AF Loehle, C TI Finding ways to beat the productivity paradox SO SCIENTIST LA English DT Editorial Material AB The productivity paradox: Despite long hours of effort and drawers full of data, much scientific work never makes it into a finished product, notes Craig Loehle, a research ecologist at Argonne National Laboratory, contending that applying a strategic focus for specific problems is the only way to increase effectiveness. RP Loehle, C (reprint author), ARGONNE NATL LAB,DIV ENVIRONM RES,ARGONNE,IL 60439, USA. NR 0 TC 0 Z9 0 U1 0 U2 1 PU SCIENTIST INC PI PHILADELPHIA PA 3600 MARKET ST SUITE 450, PHILADELPHIA, PA 19104 SN 0890-3670 J9 SCIENTIST JI Scientist PD OCT 14 PY 1996 VL 10 IS 20 BP 11 EP 11 PG 1 WC Information Science & Library Science; Multidisciplinary Sciences SC Information Science & Library Science; Science & Technology - Other Topics GA VL938 UT WOS:A1996VL93800007 ER PT J AU Tong, W Yeung, ES AF Tong, W Yeung, ES TI Determination of insulin in single pancreatic cells by capillary electrophoresis and laser-induced native fluorescence SO JOURNAL OF CHROMATOGRAPHY B-BIOMEDICAL APPLICATIONS LA English DT Article DE insulin ID LINKED-IMMUNOSORBENT-ASSAY; ZONE ELECTROPHORESIS; HUMAN ERYTHROCYTES; RAT INSULIN; NERVE-CELLS; BETA-CELLS; SECRETION; RADIOIMMUNOASSAY; DOPAMINE; PROTEINS AB Development of a method for the determination of insulin based on capillary electrophoresis with laser-induced native fluorescence detection is described. Under optimal conditions, insulin as low as 73 amol can be detected with a good signal-to-noise ratio (S/N=10 peak-to-peak). Application of this method for the determination of insulin content in single cells from the insulin-secreting cell lines RINm5F and beta TC3 is demonstrated. Non-bonded poly(ethylene oxide)-coated and bare capillaries are evaluated for this purpose, with the latter found to be more suitable for single-cell analysis. C1 IOWA STATE UNIV,US DOE,DEPT CHEM,AMES,IA 50011. IOWA STATE UNIV,US DOE,AMES LAB,AMES,IA 50011. NR 34 TC 42 Z9 45 U1 0 U2 1 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0378-4347 J9 J CHROMATOGR B JI J. Chromatogr. B-Biomed. Appl. PD OCT 11 PY 1996 VL 685 IS 1 BP 35 EP 40 DI 10.1016/0378-4347(96)00090-4 PG 6 WC Biochemical Research Methods; Chemistry, Analytical SC Biochemistry & Molecular Biology; Chemistry GA VR085 UT WOS:A1996VR08500006 PM 8930751 ER PT J AU Guss, JM Merritt, EA Phizackerley, RP Freeman, HC AF Guss, JM Merritt, EA Phizackerley, RP Freeman, HC TI The structure of a phytocyanin, the basic blue protein from cucumber, refined at 1.8 angstrom resolution SO JOURNAL OF MOLECULAR BIOLOGY LA English DT Article DE cucumber basic protein; blue copper protein; cupredoxin; phytocyanin; MAD phasing ID CRYSTAL-STRUCTURE ANALYSIS; ALCALIGENES-FAECALIS S-6; AMINO-ACID-SEQUENCE; LEAST-SQUARES REFINEMENT; COPPER-BINDING PROTEINS; ELECTRON-TRANSFER; ACTIVE-SITE; MACROMOLECULAR STRUCTURES; POPLAR PLASTOCYANIN; PHASE DETERMINATION AB The crystal structure of the cucumber basic protein (CBP), a type 1 or blue copper protein, has been refined at 1.8 Angstrom resolution. The molecule resembles other blue copper proteins in having a Greek key beta-barrel structure, except that the barrel is open on one side and is better described as a ''beta-sandwich'' or ''beta-taco''. The Cu atom has the normal blue copper NNSS' co-ordination with bond lengths Cu-N(His39) = 1.93 Angstrom, Cu-S(Cys79) = 2.16 Angstrom, Cu-N(His84) = 1.95 Angstrom, Cu-S(Met89) = 2.61 Angstrom. The Cu-S(Met) bond is the shortest so far observed in a blue copper protein. A disulphide link, (Cys52)-S-S-(Cys85), appears to play an important role in stabilising the molecular structure. It is suggested that the polypeptide fold is typical of a sub-family of blue copper proteins (phytocyanins) as well as a non-metalloprotein, ragweed allergen Ra3, with which CBP has a high degree of sequence identity. The proteins currently identifiable as phytocyanins are CBP, stellacyanin, mavicyanin, umecyanin, a cucumber peeling cupredoxin, a putative blue copper protein in pea pads, and a blue copper protein from Arabidopsis thaliana, In all except CBP and the pea-pod protein, the axial methionine Ligand normally found at blue copper sites is replaced by glutamine. The structure of CBP was originally solved by the multiple wavelength anomalous scattering method, using data recorded at four wavelengths. All these data were included in the restrained least squares refinement. The final model comprises 96 amino acid residues, 122 solvent molecules and a copper atom. Several residues are modelled as having more than one conformation. The residual R is 0.141 for 41,910 observations (including Bijvoet-related observations) of 8.142 unique reflections in the resolution range 7 to 1.8 Angstrom. (C) 1996 Academic Press Limited C1 UNIV SYDNEY,SCH CHEM,SYDNEY,NSW 2006,AUSTRALIA. STANFORD SYNCHROTRON RADIAT LAB,STANFORD,CA 94039. RI Guss, Jules/B-1283-2009 NR 76 TC 111 Z9 111 U1 1 U2 4 PU ACADEMIC PRESS LTD PI LONDON PA 24-28 OVAL RD, LONDON, ENGLAND NW1 7DX SN 0022-2836 J9 J MOL BIOL JI J. Mol. Biol. PD OCT 11 PY 1996 VL 262 IS 5 BP 686 EP 705 DI 10.1006/jmbi.1996.0545 PG 20 WC Biochemistry & Molecular Biology SC Biochemistry & Molecular Biology GA VL562 UT WOS:A1996VL56200009 PM 8876647 ER PT J AU Carlsten, BE AF Carlsten, BE TI Nonlinear subpicosecond electron-bunch compressor SO NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH SECTION A-ACCELERATORS SPECTROMETERS DETECTORS AND ASSOCIATED EQUIPMENT LA English DT Article ID ACCELERATOR AB The minimum bunch length achievable using a magnetic bunch compression system is related to the nonlinear dispersion of the compressor and the nonlinear energy-phase correlation of the bunch's longitudinal phase space. For electron bunches with medium or high charge (on the order of 1 nC, or higher), the longitudinal wakefields in the accelerating structure cause a large nonlinearity in the initial energy-phase correlation. Specific nonlinearities in the dispersion of the bunch compressor must then be introduced in order to maximally compress the bunch length, which is done by a chicane-style compressor by increasing the bend angle. This nonlinear dispersion actually decreases the rms longitudinal-beam emittance, by compensating for the nonlinearities in the beam's energy-phase correlation. In this paper, we report on the compression theory, design, and operation of such a compressor. For this compressor, introducing nonlinear dispersion reduced the minimum compressed bunch length by about a factor of 5, resulting in measured FWHM bunch lengths of 2/3 ps for bunch charges as large as 1 nC. RP Carlsten, BE (reprint author), LOS ALAMOS NATL LAB,POB 1663,LOS ALAMOS,NM 87545, USA. NR 22 TC 0 Z9 0 U1 0 U2 0 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0168-9002 J9 NUCL INSTRUM METH A JI Nucl. Instrum. Methods Phys. Res. Sect. A-Accel. Spectrom. Dect. Assoc. Equip. PD OCT 11 PY 1996 VL 380 IS 3 BP 505 EP 516 DI 10.1016/0168-9002(96)00638-9 PG 12 WC Instruments & Instrumentation; Nuclear Science & Technology; Physics, Nuclear; Physics, Particles & Fields SC Instruments & Instrumentation; Nuclear Science & Technology; Physics GA VT181 UT WOS:A1996VT18100002 ER PT J AU Scanlan, RM Barletta, WA DellOrco, D McInturff, AD Asner, A Collings, EW Dahl, PF Desportes, H Devred, A Garre, R Gregory, E Hassenzahl, W Lamm, M Larbalestier, D Leroy, D McIntyre, P Miller, J Shintomi, T tenKate, H Wipf, S AF Scanlan, RM Barletta, WA DellOrco, D McInturff, AD Asner, A Collings, EW Dahl, PF Desportes, H Devred, A Garre, R Gregory, E Hassenzahl, W Lamm, M Larbalestier, D Leroy, D McIntyre, P Miller, J Shintomi, T tenKate, H Wipf, S TI Review of the status of superconducting accelerator and detector magnets at extremely high fields SO NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH SECTION A-ACCELERATORS SPECTROMETERS DETECTORS AND ASSOCIATED EQUIPMENT LA English DT Article C1 UNIV CALIF BERKELEY,LAWRENCE BERKELEY NATL LAB,BERKELEY,CA 94720. OHIO STATE UNIV,DEPT MAT SCI & ENGN,COLUMBUS,OH 43210. US DOE,DIV HIGH ENERGY PHYS,WASHINGTON,DC 20585. CEA SACLAY,STCM,F-91191 GIF SUR YVETTE,FRANCE. EUROPA MET LMI,DE BARGA,ITALY. ADV SUPERCONDUCT IGC,INTERMAGNET GEN,WATERBURY,CT 06704. FERMILAB NATL ACCELERATOR LAB,BATAVIA,IL 60510. UNIV WISCONSIN,MADISON,WI 53706. CERN,CH-1211 GENEVA,SWITZERLAND. TEXAS A&M UNIV,DEPT PHYS,COLLEGE STN,TX 77843. NATL HIGH MAGNET FIELD LAB,TALLAHASSEE,FL 32306. KEK NAT LAB HIGH ENERGY PHYS,TSUKUBA,IBARAKI 305,JAPAN. UNIV TWENTE,APPL PHYS LOW TEMP DIV,NL-7500 AE ENSCHEDE,NETHERLANDS. DESY,DEUTSCH ELEKT SYNCHROTRON,D-2000 HAMBURG,GERMANY. RI Larbalestier, David/B-2277-2008 OI Larbalestier, David/0000-0001-7098-7208 NR 21 TC 5 Z9 5 U1 0 U2 0 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0168-9002 J9 NUCL INSTRUM METH A JI Nucl. Instrum. Methods Phys. Res. Sect. A-Accel. Spectrom. Dect. Assoc. Equip. PD OCT 11 PY 1996 VL 380 IS 3 BP 544 EP 554 DI 10.1016/0168-9002(96)00490-1 PG 11 WC Instruments & Instrumentation; Nuclear Science & Technology; Physics, Nuclear; Physics, Particles & Fields SC Instruments & Instrumentation; Nuclear Science & Technology; Physics GA VT181 UT WOS:A1996VT18100006 ER PT J AU Daftari, IK Renner, TR Verhey, LJ Singh, RP Nyman, M Petti, PL Castro, JR AF Daftari, IK Renner, TR Verhey, LJ Singh, RP Nyman, M Petti, PL Castro, JR TI New UCSF proton ocular beam facility at the Crocker Nuclear Laboratory Cyclotron (UC Davis) SO NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH SECTION A-ACCELERATORS SPECTROMETERS DETECTORS AND ASSOCIATED EQUIPMENT LA English DT Article ID CHARGED-PARTICLE THERAPY; HELIUM ION THERAPY; UVEAL MELANOMA; CHOROIDAL MELANOMA; IRRADIATION; ENUCLEATION AB A new facility has been constructed at the Crocker Nuclear Laboratory at University of California Davis for the purpose of treating ocular tumors using the 67.5 MeV protons from the 76-in. isochronous cyclotron. Beam line design, commissioning, control system, beam characteristics, dosimetry, patient positioner and system performance are discussed. The unmodulated Bragg peak has a penetration of 29 mm in tissue at the isocenter with a peak to plateau ratio of 3.8:1 and a width of 5 mm (FWHM measured in water). The delivered dose is monitored by two transmission ionization chambers which are calibrated against a thimble ionization chamber with an NIST-traceable Co-60 calibration factor. The Bragg peak is spread across the target volume by the use of range modulators. The residual range is varied by means of a variable water column. Daily variation in patient dosimetry is within +/-3%. The beam penumbra (defined here as the distance between the 90% and 10% isodose levels) is 1.5 mm for a range-modulated beam at a collimator-to-isocenter distance of 50 mm. The beam flatness in a 25 mm diameter beam is within +/-2% and the beam symmetry is +/-1%. In the first 18 months, 50 patients have been treated with an average field size of 16.8 x 16.6 mm(2). The residual range varied between 13.0 mm to 29.2 mm with an average value of 22.4 mm, and the range modulation varied between 16 mm to 24 mm with an average value of 20 mm. The tumor thickness (height) ranged between 1.2 to 11.5 mm with mean of 5.2 mm. The age of the patients ranged from 25 to 88 yr. C1 ERNEST ORLANDO LAWRENCE BERKELEY NATL LAB,BERKELEY,CA 94720. RP Daftari, IK (reprint author), UNIV CALIF SAN FRANCISCO,DEPT RADIAT ONCOL,505 PARNASSUS AV,SAN FRANCISCO,CA 94143, USA. NR 28 TC 22 Z9 22 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 OCT 11 PY 1996 VL 380 IS 3 BP 597 EP 612 DI 10.1016/0168-9002(96)00707-3 PG 16 WC Instruments & Instrumentation; Nuclear Science & Technology; Physics, Nuclear; Physics, Particles & Fields SC Instruments & Instrumentation; Nuclear Science & Technology; Physics GA VT181 UT WOS:A1996VT18100014 ER PT J AU Schoenlein, RW Leemans, WP Chin, AH Volfbeyn, P Glover, TE Balling, P Zolotorev, M Kim, KJ Chattopadhyay, S Shank, CV AF Schoenlein, RW Leemans, WP Chin, AH Volfbeyn, P Glover, TE Balling, P Zolotorev, M Kim, KJ Chattopadhyay, S Shank, CV TI Femtosecond x-ray pulses at 0.4 angstrom generated by 90 degrees Thomson scattering: A tool for probing the structural dynamics of materials SO SCIENCE LA English DT Article ID LASER SYNCHROTRON SOURCE; COMPACT AB Pulses of x-rays 300 femtoseconds in duration at a wavelength of 0.4 angstroms (30,000 electron volts) have been generated by 90 degrees Thomson scattering between infrared tera-watt laser pulses and highly relativistic electrons from an accelerator, In the right-angle scattering geometry, the duration of the x-ray burst is determined by the transit time of the laser pulse across the similar to 90-micrometer waist of the focused electron beam, The x-rays are highly directed (similar to 0.6 degrees divergence) and can be tuned in energy. This source of femtosecond x-rays will make it possible to combine x-ray techniques with ultrafast time resolution to investigate structural dynamics in condensed matter. C1 UNIV CALIF BERKELEY,LAWRENCE BERKELEY LAB,CTR BEAM PHYS,DIV ACCELERATOR & FUS RES,BERKELEY,CA 94720. UNIV CALIF BERKELEY,DEPT PHYS,BERKELEY,CA 94720. RP Schoenlein, RW (reprint author), UNIV CALIF BERKELEY,LAWRENCE BERKELEY LAB,DIV MAT SCI,BERKELEY,CA 94720, USA. RI Balling, Peter/D-8116-2013; Schoenlein, Robert/D-1301-2014 OI Balling, Peter/0000-0003-4955-770X; Schoenlein, Robert/0000-0002-6066-7566 NR 18 TC 377 Z9 390 U1 1 U2 31 PU AMER ASSOC ADVANCEMENT SCIENCE PI WASHINGTON PA 1200 NEW YORK AVE, NW, WASHINGTON, DC 20005 SN 0036-8075 J9 SCIENCE JI Science PD OCT 11 PY 1996 VL 274 IS 5285 BP 236 EP 238 DI 10.1126/science.274.5285.236 PG 3 WC Multidisciplinary Sciences SC Science & Technology - Other Topics GA VM671 UT WOS:A1996VM67100040 ER PT J AU Chlopecka, A AF Chlopecka, A TI Assessment of form of Cd, Zn and Pb in contaminated calcareous and gleyed soils in southwest Poland SO SCIENCE OF THE TOTAL ENVIRONMENT LA English DT Article DE calcareous; gleysols; rendzina; hydromorphic; sequential extraction; heavy metals ID UPPER SILESIA; CADMIUM; LEAD; ZINC; COPPER; PH AB A knowledge of the total amount of trace metals in soils is generally not sufficient to assess environmental impacts of metal contamination. Quantification of different metal forms enables evaluation of their behavior and of their eventual bioavailability in the soil environment. Calcareous and gleyed soils contaminated by Cd, Pb and Zn found in the heavily industrialized area of Tarnowskie Gory (Upper Silesia, Poland) were examined by sequential extraction analysis to assess the forms of these metals in a range extending from background levels to concentrations well in excess of those prescribed as the maximum tolerable limits for Polish soils. Cadmium ranged from 0.41 to 25.5, Pb from 12.7 to 1730 and Zn from 13.9 to 2800 mu g g(-1) soil, respectively. In general, the metals were associated with more mobile forms in the contaminated soils and particularly in the gleyed soils which tended to be acidic is nature. RP Chlopecka, A (reprint author), UNIV GEORGIA, SAVANNAH RIVER ECOL LAB, BIOGEOCHEM ECOL DIV, DRAWER E, AIKEN, SC 29802 USA. NR 26 TC 46 Z9 51 U1 1 U2 4 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0048-9697 J9 SCI TOTAL ENVIRON JI Sci. Total Environ. PD OCT 11 PY 1996 VL 188 IS 2-3 BP 253 EP 262 DI 10.1016/0048-9697(96)05182-0 PG 10 WC Environmental Sciences SC Environmental Sciences & Ecology GA VK898 UT WOS:A1996VK89800015 ER PT J AU Becher, PF Sun, EY Hsueh, CH Alexander, KB Hwang, SL Waters, SB Westmoreland, CG AF Becher, PF Sun, EY Hsueh, CH Alexander, KB Hwang, SL Waters, SB Westmoreland, CG TI Debonding of interfaces between beta-silicon nitride whiskers and Si-Al-Y oxynitride glasses SO ACTA MATERIALIA LA English DT Article ID DISSIMILAR ELASTIC-MATERIALS; FRACTURE-TOUGHNESS; REINFORCED CERAMICS; THERMAL-EXPANSION; CRACK DEFLECTION; STRESSES; MATRIX; ENERGY AB Crack bridging mechanisms in self-reinforced silicon nitride ceramics rely on interfacial debonding and intergranular fracture processes. The toughening effects can be enhanced by increasing the diameter of the elongated grains. However, the composition of the additives and, hence, the grain boundary amorphous phase can significantly alter this response; the question remains as to whether this is due to interfacial structure and bonding or the state of residual stresses. Here studies of debonding of the interfaces associated with beta-Si3N4 whiskers embedded in oxynitride glasses are used to examine the role of oxynitride glass composition on the debonding behavior. Using indentation cracking, measurements of interfacial debond lengths versus angle of incidence (i.e. between crack plane and interface plane) are used to determine the critical angle for debonding which can be related to debonding energy. In Si-Al-Y-O-N glasses, it is found that increases in the Y:Al and O:N ratios promote interfacial debonding. At the same time, the properties of the glasses are dependent upon composition. As a result, the thermal expansion mismatch stresses imposed on the whisker by the glass also vary with composition. Thus, the influence of thermal expansion mismatch stresses on the interface debonding was considered by analyses of the radial and the axial stresses using the measured glass properties. These results show that thermal expansion mismatch stresses are not a factor in interfacial debonding in the current experiments. Rather, interfacial compositional profile analyses and high resolution microstructural characterization of the interfaces reveal that the observed compositional effects on debonding behavior are related to formation of interfacial phases, in this case the growth of a beta'-SiAlON layer. Copyright (C) 1996 Acta Metallurgica Inc. RP Becher, PF (reprint author), OAK RIDGE NATL LAB,DIV MET & CERAM,POB 2008,OAK RIDGE,TN 37831, USA. RI Hsueh, Chun-Hway/G-1345-2011 NR 34 TC 90 Z9 90 U1 0 U2 13 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD, ENGLAND OX5 1GB SN 1359-6454 J9 ACTA MATER JI Acta Mater. PD OCT 10 PY 1996 VL 44 IS 10 BP 3881 EP 3893 DI 10.1016/S1359-6454(96)00069-9 PG 13 WC Materials Science, Multidisciplinary; Metallurgy & Metallurgical Engineering SC Materials Science; Metallurgy & Metallurgical Engineering GA VL575 UT WOS:A1996VL57500001 ER PT J AU Maudlin, PJ Wright, SI Kocks, UF Sahota, MS AF Maudlin, PJ Wright, SI Kocks, UF Sahota, MS TI An application of multisurface plasticity theory: Yield surfaces of textured materials SO ACTA MATERIALIA LA English DT Article ID DEFORMATION; ALGORITHM; STRESS AB Directionally dependent descriptions of material yield as determined by polycrystal plasticity computations are discrete in nature and, in principle, are available for use in large-scale application calculations employing multi-dimensional continuum mechanics codes. However, the practical side of using such detailed yield surfaces in application calculations contains some challenges in terms of algorithm development and computational efficiency. Pole figures, commonly measured by X-ray diffraction, are used to portray the distribution of crystallographic grain orientations in a polycrystalline material. The calculated orientation distribution can then be used to weight a set of discrete orientations to generate a representation of the measured texture. This discrete representation can be probed in the context of a Taylor-Bishop-Hill polycrystal calculation in order to assemble a set of deviatoric stress points that discretely map out the material's yield surface. These stress points can be fitted or tessellated into a multi-dimensional piece-wise linear representation of the yield surface for subsequent use in a continuum code constitutive algorithm. Such an algorithm that utilizes an associated flow based multisurface plasticity theory has been implemented in the three dimensional portion of the EPIC continuum mechanics code and is described in this effort. RP Maudlin, PJ (reprint author), LOS ALAMOS NATL LAB,POB 1663,LOS ALAMOS,NM 87545, USA. RI Kocks, Fred/E-1159-2011 NR 20 TC 18 Z9 19 U1 0 U2 3 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD, ENGLAND OX5 1GB SN 1359-6454 J9 ACTA MATER JI Acta Mater. PD OCT 10 PY 1996 VL 44 IS 10 BP 4027 EP 4032 DI 10.1016/S1359-6454(96)00039-0 PG 6 WC Materials Science, Multidisciplinary; Metallurgy & Metallurgical Engineering SC Materials Science; Metallurgy & Metallurgical Engineering GA VL575 UT WOS:A1996VL57500013 ER PT J AU Asta, M AF Asta, M TI Theoretical study of the thermodynamic properties of alpha-delta' interphase boundaries in Al-Li SO ACTA MATERIALIA LA English DT Article ID 2ND-NEIGHBOR INTERACTIONS; PHASE-EQUILIBRIUM; ISING-MODEL; ALLOYS; 1ST-NEIGHBOR; ENERGY AB The thermodynamic properties of coherent interphase-boundary interfaces between alpha and delta' phases in the Al-Li alloy system have been studied using a theoretical approach based on the cluster variation method. Interfacial excess free energies have been calculated for interphase boundaries with {100} and {111} crystallographic orientations at several temperatures ranging between 100 and 209 degrees C. Additionally, the dependencies of the average composition and the order parameter upon distance within the compositionally diffuse interfacial regions have been computed. The calculated interphase energies range between 7 and 11 mJ/m(2). From an analysis of the calculated composition and order-parameter profiles, interface widths are predicted to be as large as 27 Angstrom. RP Asta, M (reprint author), SANDIA NATL LABS,COMPUTAT MAT SCI DIV,POB 969,MS 9163,LIVERMORE,CA 94551, USA. NR 37 TC 21 Z9 21 U1 1 U2 4 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD, ENGLAND OX5 1GB SN 1359-6454 J9 ACTA MATER JI Acta Mater. PD OCT 10 PY 1996 VL 44 IS 10 BP 4131 EP 4136 DI 10.1016/S1359-6454(96)00030-4 PG 6 WC Materials Science, Multidisciplinary; Metallurgy & Metallurgical Engineering SC Materials Science; Metallurgy & Metallurgical Engineering GA VL575 UT WOS:A1996VL57500022 ER PT J AU Smith, PM Elmer, JW AF Smith, PM Elmer, JW TI Homogeneous nucleation ahead of the solid-liquid interface during rapid solidification of binary alloys SO ACTA MATERIALIA LA English DT Article ID AL-BE ALLOYS; HETEROGENEOUS NUCLEATION; STRUCTURAL MODEL; PARTICLES AB In recent rapid solidification experiments on Al-5%Be alloys, a Liquid Phase Nucleation (LPN) model was developed to explain the formation of periodic arrays of randomly-oriented Be-rich particles in an Al-rich matrix. In the LPN model, Be droplets were assumed to nucleate in the liquid ahead of the solid-liquid interface, but no justification for this was given. Here we present a model which considers the geometric constraints (imposed by proximity to the interface) on the number of solute atoms available to form a nucleus. Calculations based on this model predict that nucleation of second-phase particles can be most likely a short distance ahead of the interface in immiscible binary systems such as Al-Be. As Dart of the nucleation calculations, a semi-empirical method of calculating solid-liquid surface tensions in binary systems was developed, and is presented in the Appendix. RP Smith, PM (reprint author), LAWRENCE LIVERMORE NATL LAB,POB 808,L-271,LIVERMORE,CA 94550, USA. NR 21 TC 3 Z9 3 U1 1 U2 5 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD, ENGLAND OX5 1GB SN 1359-6454 J9 ACTA MATER JI Acta Mater. PD OCT 10 PY 1996 VL 44 IS 10 BP 4217 EP 4224 DI 10.1016/S1359-6454(96)00035-3 PG 8 WC Materials Science, Multidisciplinary; Metallurgy & Metallurgical Engineering SC Materials Science; Metallurgy & Metallurgical Engineering GA VL575 UT WOS:A1996VL57500031 ER PT J AU Beye, R Verwerft, M DeHosson, JTM Gronsky, R AF Beye, R Verwerft, M DeHosson, JTM Gronsky, R TI Oxidation subscale of gamma-titanium aluminide SO ACTA MATERIALIA LA English DT Article ID BEAM ELECTRON-DIFFRACTION; INTERMETALLIC ALLOYS AB The subscale formed during high temperature rapid oxidation of gamma-titanium aluminum is revealed by transmission electron microscopy and microanalysis to consist of two phases: one hexagonal with unit cell dimensions a = 0.58 nm, c = 0.47 nm (+/- 0.005 nm), and a composition close to Ti6Al3O4; the other simple cubic with a = 0.69 nm (+/-0.005 nm) and composition Ti3Al2O3, with oxygen concentration known to about 10% accuracy. The results strongly suggest that the hexagonal phase is a solid solution of O in Ti3Al, while the cubic phase is a novel ternary compound with space group P4(2)32. These subscale phases exhibit some tendency for a crystallographic orientation relationship with (110)(cubic)//(01 (1) over bar 0)(hexagonal) and [0 (1) over bar 1](cubic)/[(2) over bar 112](hexagonal), and the hexagonal phase is less stable than the cubic phase as the distance to the sample surface decreases and oxygen level increases. C1 UNIV GRONINGEN,DEPT APPL PHYS,GRONINGEN,NETHERLANDS. RP Beye, R (reprint author), UNIV CALIF BERKELEY,LAWRENCE BERKELEY LAB,DEPT MAT SCI & MINERAL ENGN,DIV SCI MAT,BERKELEY,CA 94720, USA. RI De Hosson, Jeff/C-2169-2013 NR 17 TC 32 Z9 33 U1 2 U2 5 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD, ENGLAND OX5 1GB SN 1359-6454 J9 ACTA MATER JI Acta Mater. PD OCT 10 PY 1996 VL 44 IS 10 BP 4225 EP 4231 DI 10.1016/S1359-6454(96)00032-8 PG 7 WC Materials Science, Multidisciplinary; Metallurgy & Metallurgical Engineering SC Materials Science; Metallurgy & Metallurgical Engineering GA VL575 UT WOS:A1996VL57500032 ER PT J AU Keller, C deLlano, M Ren, SZ Solis, MA Baker, GA AF Keller, C deLlano, M Ren, SZ Solis, MA Baker, GA TI Ouantum-hard-sphere system equations of state revisited SO ANNALS OF PHYSICS LA English DT Article ID ENERGY; FERMION; FLUIDS; LIQUID-HE-3 AB Analytical equations of state for boson and fermion hard-sphere fluids ranging from very low to very high densities are constructed. Such equations of state serve as a zero-order (reference) state upon which to build so-called quantum-thermodynamic-perturbation corrections in describing real but simple quantum fluids at zero temperature. The fluid branch extrapolations from the exact low-density series expansions For the energy are carried out by incorporating various physical arguments, such as close packing densities and residues. Modified London equations of state for the high-density crystalline branch agree very well with computer simulations, and at close packing with certain experimental results at high pressure. (C) 1996 Academic Press, Inc. C1 N DAKOTA STATE UNIV,DEPT PHYS,FARGO,ND 58105. UNIV NACL AUTONOMA MEXICO,INST FIS,MEXICO CITY 01000,DF,MEXICO. LOS ALAMOS NATL LAB,DIV THEORET,LOS ALAMOS,NM 87545. RP Keller, C (reprint author), UNIV S DAKOTA,DEPT PHYS,VERMILLION,SD 57069, USA. NR 35 TC 4 Z9 4 U1 0 U2 0 PU ACADEMIC PRESS INC JNL-COMP SUBSCRIPTIONS PI SAN DIEGO PA 525 B ST, STE 1900, SAN DIEGO, CA 92101-4495 SN 0003-4916 J9 ANN PHYS-NEW YORK JI Ann. Phys. PD OCT 10 PY 1996 VL 251 IS 1 BP 64 EP 75 DI 10.1006/aphy.1996.0107 PG 12 WC Physics, Multidisciplinary SC Physics GA VM516 UT WOS:A1996VM51600004 ER PT J AU Lineweaver, CH Tenorio, L Smoot, GF Keegstra, P Banday, AJ Lubin, P AF Lineweaver, CH Tenorio, L Smoot, GF Keegstra, P Banday, AJ Lubin, P TI The dipole observed in the COBE DMR 4 year data SO ASTROPHYSICAL JOURNAL LA English DT Article DE cosmic microwave background; cosmology, observations ID DIFFERENTIAL MICROWAVE RADIOMETERS; MAPS AB The largest anisotropy in the cosmic microwave background (CMB) is the approximate to 3 mK dipole assumed to be due to our velocity with respect to the CMB. Using the 4 year data set from all six channels of the COBE Differential Microwave Radiometers (DMR), we obtain a best-fit dipole amplitude 3.358+/-0.001+/-0.023 mK in the direction (l, b)=(264.degrees 31+/-0.degrees 04+/-0.degrees 16, +48.degrees 05+/-0.degrees 02+/-0.degrees 09), where the first uncertainties are statistical. and the second include calibration and combined systematic uncertainties. This measurement is consistent with previous DMR and FIRAS results. C1 UNIV CARLOS III MADRID,MADRID,SPAIN. UNIV CALIF BERKELEY,LAWRENCE BERKELEY LAB,SPACE SCI LAB,BERKELEY,CA 94720. UNIV CALIF BERKELEY,CTR PARTICLE ASTROPHYS,BERKELEY,CA 94720. NASA,GODDARD SPACE FLIGHT CTR,HUGHES STX CORP,ASTRON & SOLAR PHYS LAB,GREENBELT,MD 20771. MAX PLANCK INST ASTROPHYS,D-85740 GARCHING,GERMANY. UNIV CALIF SANTA BARBARA,DEPT PHYS,SANTA BARBARA,CA 93106. RP Lineweaver, CH (reprint author), OBSERV STRASBOURG,F-67000 STRASBOURG,FRANCE. NR 12 TC 120 Z9 120 U1 0 U2 2 PU UNIV CHICAGO PRESS PI CHICAGO PA 5720 S WOODLAWN AVE, CHICAGO, IL 60637 SN 0004-637X J9 ASTROPHYS J JI Astrophys. J. PD OCT 10 PY 1996 VL 470 IS 1 BP 38 EP 42 DI 10.1086/177846 PN 1 PG 5 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA VL723 UT WOS:A1996VL72300002 ER PT J AU Szapudi, I Colombi, S AF Szapudi, I Colombi, S TI Cosmic error and statistics of large-scale structure SO ASTROPHYSICAL JOURNAL LA English DT Article DE large-scale structure of the universe; methods, numerical; methods, statistical ID 3-POINT CORRELATION-FUNCTION; GALAXY CORRELATION-FUNCTION; HIGHER-ORDER STATISTICS; COLD DARK MATTER; CLUSTER CORRELATIONS; REDSHIFT SURVEY; EXTRAGALACTIC OBJECTS; CORRELATION HIERARCHY; ZWICKY CATALOG; IRAS GALAXIES AB We use a generating function approach to examine the errors on quantities related to counts in cells extracted from galaxy surveys. The measurement error, related to the finite number of sampling cells, is distinguished from the ''cosmic error,'' due to the finiteness of the survey. While the measurement error can be circumvented through the application of a proper algorithm, the cosmic error is an irrecoverable property of any survey. Using the hierarchical model and assuming locally Poisson behavior, we identify three contributions to the cosmic error: 1. The finite volume effect is proportional to the average of the two-point correlation function over the whole survey. It accounts for possible fluctuations of the density field at scales larger than the sample size. 2. The edge effect is related to the geometry of the survey. It accounts for the fact that objects near the boundary carry less statistical weight than those further away from it. 3. The discreteness effect is due to the fact that the underlying smooth random held is sampled with finite number of objects. This is the ''shot noise'' error. To check the validity of our results, we measured the factorial moments of order N less than or equal to 4 in a large number of small subsamples randomly extracted from a hierarchical sample realized by Raighley-Levy random walks. The measured statistical errors are in excellent agreement with our predictions. The probability distribution of errors is increasingly skewed when the order N and/or the cell size increases. This suggests that ''cosmic errors'' tend to be systematic: it is likely to underestimate the true value of the factorial moments. Our study of the various regimes showed that the errors strongly depend on the clustering of the system, i.e., on the hierarchy of underlying correlations. The Gaussian approximation is valid only in the weakly nonlinear regime, otherwise it severely underestimates the true errors. We study the concept of ''number of statistically independent cells '' (re)defined as the number of sampling cells required to have the measurement error of same order as the cosmic error. This number is found to depend highly on the statistical object under study and is generally quite different from the number of cells needed to cover the survey volume. In light of these findings we advocate high oversampling for measurements of counts in cells. As a preliminary application to realistic situations, we study contour plots of the cosmic error expected in typical three-dimensional galaxy catalogs. C1 CANADIAN INST THEORET ASTROPHYS,TORONTO,ON M5S 3H8,CANADA. RP Szapudi, I (reprint author), FERMILAB NATL ACCELERATOR LAB,NASA,FERMILAB ASTROPHYS CTR,BATAVIA,IL 60510, USA. NR 53 TC 79 Z9 79 U1 0 U2 2 PU UNIV CHICAGO PRESS PI CHICAGO PA 5720 S WOODLAWN AVE, CHICAGO, IL 60637 SN 0004-637X J9 ASTROPHYS J JI Astrophys. J. PD OCT 10 PY 1996 VL 470 IS 1 BP 131 EP 148 DI 10.1086/177855 PN 1 PG 18 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA VL723 UT WOS:A1996VL72300011 ER PT J AU Armitage, PJ Zurek, WH Davies, MB AF Armitage, PJ Zurek, WH Davies, MB TI Red giant disk encounters: Food for quasars? SO ASTROPHYSICAL JOURNAL LA English DT Article DE galaxies, active; hydrodynamics; methods, numerical; stars, kinematics; stars, mass loss ID ACTIVE GALACTIC NUCLEI; MASSIVE BLACK-HOLE; ACCRETION DISK; STAR; EVOLUTION; SYSTEMS; MODELS; CONSTRAINTS; COLLISIONS; OPACITIES AB We explore the role that red giants might play in the fueling and evolution of active galactic nuclei (AGNs). Due to their large radii and the low binding energy of the stellar envelope, giants are vulnerable to envelope stripping from collisions with the accretion disk. Using hydrodynamic simulations, we show that such collisions will typically deposit a substantial fraction of the envelope mass into the disk on each passage. Repeated encounters will then lead to the complete destruction of the star save for the dense core. We estimate the rate of fuel supply by this mechanism using simple models for the AGN disk and central stellar cluster. If the central stellar density is similar to 10(7) M. pc(-3), then stripping of giants could account for the activity of typical AGNs provided that the accretion disk extends out to similar to 0.1 pc. For AGNs with smaller disks, or clusters of lower central density, giant stripping could supply gas enriched via stellar nucleosynthesis to a disk replenished from some other source. We find that, for typical parameters, this mechanism is able to supply important quantities of gas to the disk at lower stellar densities than previously proposed stellar fueling models for AGNs. C1 LOS ALAMOS NATL LAB, LOS ALAMOS, NM 87545 USA. RP Armitage, PJ (reprint author), INST ASTRON, MADINGLEY RD, CAMBRIDGE CB3 0HA, ENGLAND. NR 35 TC 25 Z9 25 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 OCT 10 PY 1996 VL 470 IS 1 BP 237 EP 248 DI 10.1086/177864 PN 1 PG 12 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA VL723 UT WOS:A1996VL72300020 ER PT J AU Alcock, C Allsman, RA Alves, DR Axelrod, TS Becker, A Bennett, DP Clayton, GC Cook, KH Freeman, KC Griest, K Guern, JA Kilkenny, D Lehner, MJ Marshall, SL Minniti, D Peterson, BA Pratt, MR Quinn, PJ Rodgers, AW Stubbs, CW Sutherland, W Welch, DL AF Alcock, C Allsman, RA Alves, DR Axelrod, TS Becker, A Bennett, DP Clayton, GC Cook, KH Freeman, KC Griest, K Guern, JA Kilkenny, D Lehner, MJ Marshall, SL Minniti, D Peterson, BA Pratt, MR Quinn, PJ Rodgers, AW Stubbs, CW Sutherland, W Welch, DL TI The macho project large Magellanic Cloud variable star inventory .4. New R Coronae Borealis stars SO ASTROPHYSICAL JOURNAL LA English DT Article DE gravitational lensing; stars, variables, other (R Coronae Borealis); Magellanic Clouds ID RCB STARS; SAGITTARII; SPECTRUM; DUST; LMC AB We report the discovery of two new R Coronae Borealis (RCB) stars in the LMC using the MACHO project photometry database. The identification of both stars has been confirmed spectroscopically. One is a cool RCB star (T-eff similar to 5000 K), characterized by very strong Swan bands of C-2 and violet bands of CN, and weak. or absent Balmer lines, G band, and (CC)-C-12-C-13 bands. The second star is an example of a hot RCB star, of which only three were previously known to exist in the Galaxy and none in the LMC. Its spectrum is characterized by several C II lines in emission. Both stars have shown deep declines of Delta V greater than or equal to 4 mag in brightness. The new stars are significantly fainter at maximum light than the three previously known LMC RCB stars. The amount of reddening toward these stars is somewhat uncertain, but both seem to have absolute magnitudes, M(v), similar to 0.5 mag fainter than the other three stars. Estimates of M(bol) find that the hot RCB star lies in the range of the other three stars, while the cool RCB star is fainter. The two cool LMC RCB stars are the faintest at M(bol). The discovery of these two new stars brings to five the number of known RCB stars in the LMC, and it demonstrates the utility of the MACHO photometric database for the discovery of new RCB stars. C1 UNIV CALIF BERKELEY,CTR PARTICLE ASTROPHYS,BERKELEY,CA 94720. UNIV CALIF DAVIS,DEPT PHYS,DAVIS,CA 95616. UNIV WASHINGTON,DEPT ASTRON,SEATTLE,WA 98195. LOUISIANA STATE UNIV,DEPT PHYS & ASTRON,BATON ROUGE,LA 70803. AUSTRALIAN NATL UNIV,MT STROMLO & SIDING SPRING OBSERV,WESTON,ACT 2611,AUSTRALIA. UNIV CALIF SAN DIEGO,DEPT PHYS,SAN DIEGO,CA 92093. S AFRICAN ASTRON OBSERV,ZA-7935 CAPE TOWN,SOUTH AFRICA. S AFRICAN ASTRON OBSERV,ZA-7935 CAPE TOWN,SOUTH AFRICA. UNIV CALIF SANTA BARBARA,DEPT PHYS,SANTA BARBARA,CA 93106. UNIV OXFORD,DEPT PHYS,OXFORD OX1 3RH,ENGLAND. MCMASTER UNIV,DEPT PHYS & ASTRON,HAMILTON,ON L8S 4M1,CANADA. RP Alcock, C (reprint author), LAWRENCE LIVERMORE NATL LAB,LIVERMORE,CA 94550, USA. RI Quinn, Peter/B-3638-2013; Bennett, David/O-2136-2013; Stubbs, Christopher/C-2829-2012; OI Bennett, David/0000-0001-8043-8413; Stubbs, Christopher/0000-0003-0347-1724; Welch, Doug/0000-0002-2350-0898 NR 52 TC 35 Z9 35 U1 0 U2 1 PU UNIV CHICAGO PRESS PI CHICAGO PA 5720 S WOODLAWN AVE, CHICAGO, IL 60637 SN 0004-637X J9 ASTROPHYS J JI Astrophys. J. PD OCT 10 PY 1996 VL 470 IS 1 BP 583 EP 590 DI 10.1086/177890 PN 1 PG 8 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA VL723 UT WOS:A1996VL72300046 ER PT J AU Savin, DW Beiersdorfer, P LopezUrrutia, JC Decaux, V Gullikson, EM Kahn, SM Liedahl, DA Reed, KJ Widmann, K AF Savin, DW Beiersdorfer, P LopezUrrutia, JC Decaux, V Gullikson, EM Kahn, SM Liedahl, DA Reed, KJ Widmann, K TI Laboratory measurements of Fe XXIV L-shell line emission SO ASTROPHYSICAL JOURNAL LA English DT Article DE atomic data; atomic processes; methods, laboratory; X-rays, general ID X-RAY-SPECTRUM; HIGHLY-CHARGED IONS; ELECTRON-BEAM; CROSS-SECTIONS; TRAP AB Recent ASCA spectra exhibit discrepancies with the relative line intensities of various Fe XXIII and XXIV L-shell emission lines predicted by standard plasma emission codes. To address this issue, we have carried out a series of high-resolution, broadband measurements of Fe XXIV line emission using an electron beam ion trap facility. X-ray lines produced in the trap are detected and resolved using Bragg crystal spectrometers. We report measurements of 3 --> 2 and 4 --> 2 transitions, which result primarily from electron impact excitation. Overall, good agreement is found with distorted wave calculations. C1 UNIV CALIF BERKELEY,DEPT PHYS,BERKELEY,CA 94720. UNIV CALIF BERKELEY,DEPT ASTRON,BERKELEY,CA 94720. UNIV CALIF BERKELEY,SPACE SCI LAB,BERKELEY,CA 94720. LAWRENCE LIVERMORE NATL LAB,LIVERMORE,CA 94550. UNIV CALIF BERKELEY,LAWRENCE BERKELEY LAB,BERKELEY,CA 94720. RI Crespo Lopez-Urrutia, Jose R./F-7069-2011; Savin, Daniel/B-9576-2012 OI Crespo Lopez-Urrutia, Jose R./0000-0002-2937-8037; Savin, Daniel/0000-0002-1111-6610 NR 23 TC 18 Z9 18 U1 2 U2 2 PU UNIV CHICAGO PRESS PI CHICAGO PA 5720 S WOODLAWN AVE, CHICAGO, IL 60637 SN 0004-637X J9 ASTROPHYS J JI Astrophys. J. PD OCT 10 PY 1996 VL 470 IS 1 BP L73 EP L76 DI 10.1086/310300 PN 2 PG 4 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA VL724 UT WOS:A1996VL72400018 ER PT J AU Saavedra, HI Wang, TH Hoyt, PR Popp, D Yang, WK Stambrook, PJ AF Saavedra, HI Wang, TH Hoyt, PR Popp, D Yang, WK Stambrook, PJ TI Interleukin-3 increases the incidence of 5-azacytidine-induced thymic lymphomas in pBOR-II-3 mice SO CELLULAR IMMUNOLOGY LA English DT Article ID COLONY-STIMULATING FACTOR; GROWTH-FACTOR ACTIVITY; LONG TERMINAL REPEAT; MULTI-CSF IL-3; 20-ALPHA-HYDROXYSTEROID DEHYDROGENASE; SPLENIC LYMPHOCYTES; RETROVIRAL GENOMES; INVITRO; LEUKEMIA; DIFFERENTIATION AB Interleukin-3 (Il-3) is a glycoprotein produced by a CD4(+)CD8(-) subpopulation of T-lymphocytes. Il-3 has been associated with the proliferation of bone marrow stem cells and their differentiation to granulocytes, macrophages, basophil/mast cells, megakaryocytes, erythroid cells, and neutrophils. The pBOR-Il-3 transgenic mice were developed by pronuclear microinjection to study how chemical insults modulate transcription of the Il-3 gene driven by a long-terminal repeat (LTR) of an endogenous retrovirus and to determine the biological consequences of interleukin-3 expression. We injected 5-azacytidine, a demethylating agent, to increase the LTR-driven expression of Il-3. Upon 5-azacytidine treatment, both the pBOR-Il-3 and the FVB/N nontransgenic controls developed thymic lymphomas. The pBOR-Il-3 mice developed thymic lymphomas at a higher frequency than the FVB/N mice. The thymic lymphoma cells were of a T-cell origin, as determined by T-cell receptor gene rearrangement analysis, and, in most cases, were of monoclonal origin. According to flow cytometric analysis of CD3, CD4, and CD8 cell surface markers, the thymic lymphoma cells did not lose their ability to differentiate, but the differentiation process was aberrant. Flow cytometric analyses also revealed that in pBOR-Il-3 mice the thymic lymphomas are mostly of a CD8(+)CD4(-) origin, whereas in the FVB/N group, the predominant type of thymic lymphoma is of a CD4(+)CD8(-) origin. (C) 1996 Academic Press, Inc. C1 UNIV TENNESSEE,KNOXVILLE,TN 37996. OAK RIDGE NATL LAB,DIV BIOL,OAK RIDGE,TN 37831. ACAD SINICA,INST BIOMED SCI,TAIPEI 1105,TAIWAN. RP Saavedra, HI (reprint author), UNIV CINCINNATI,COLL MED,DEPT ANAT NEUROBIOL & CELL BIOL,POB 670521,231 BETHESDA AVE,CINCINNATI,OH 45267, USA. FU NCI NIH HHS [P2-CA-09336]; NIEHS NIH HHS [YO1-ES-4-0018, ES07250] NR 48 TC 4 Z9 4 U1 0 U2 0 PU ACADEMIC PRESS INC JNL-COMP SUBSCRIPTIONS PI SAN DIEGO PA 525 B ST, STE 1900, SAN DIEGO, CA 92101-4495 SN 0008-8749 J9 CELL IMMUNOL JI Cell. Immunol. PD OCT 10 PY 1996 VL 173 IS 1 BP 116 EP 123 DI 10.1006/cimm.1996.0257 PG 8 WC Cell Biology; Immunology SC Cell Biology; Immunology GA VN241 UT WOS:A1996VN24100013 PM 8871607 ER PT J AU Hou, HQ Crawford, MH Hickman, RJ Hammons, BE AF Hou, HQ Crawford, MH Hickman, RJ Hammons, BE TI Room-temperature continuous wave operation of all-AlGaAs visible (similar to 700nm) vertical-cavity surface emitting lasers SO ELECTRONICS LETTERS LA English DT Article DE vertical cavity surface emitting lasers; visible semiconductor lasers ID OXYGEN AB The authors present the first demonstration of the room-temperature continuous-wave operation of AlGaAs quantum well red (similar to 700nm) vertical-cavity surface emitting lasers fabricated by the selective oxidation process. The threshold current is similar to 3.2mA with an output power of up to 44 mu W. The laser structures, containing five Al0.24Ga0.76As quantum wells, were grown on GaAs (311)A substrates by metal organic vapour phase epitaxy. RP Hou, HQ (reprint author), SANDIA NATL LABS,MS 0603,ALBUQUERQUE,NM 87185, USA. NR 8 TC 2 Z9 2 U1 0 U2 1 PU IEE-INST ELEC ENG PI HERTFORD PA MICHAEL FARADAY HOUSE SIX HILLS WAY STEVENAGE, HERTFORD, ENGLAND SG1 2AY SN 0013-5194 J9 ELECTRON LETT JI Electron. Lett. PD OCT 10 PY 1996 VL 32 IS 21 BP 1986 EP 1987 DI 10.1049/el:19961337 PG 2 WC Engineering, Electrical & Electronic SC Engineering GA VM817 UT WOS:A1996VM81700038 ER PT J AU Fritz, IJ Drummond, TJ Lee, SR Hafich, MJ Howard, AJ Briggs, RD Vawter, GA Armendariz, MG Hietala, VM AF Fritz, IJ Drummond, TJ Lee, SR Hafich, MJ Howard, AJ Briggs, RD Vawter, GA Armendariz, MG Hietala, VM TI Vertical-cavity optical modulator for 1.32 mu m grown on a graded (InGaAl)As buffer SO ELECTRONICS LETTERS LA English DT Article DE electroabsorption modulators; vertical cavity surface emitting lasers ID REFLECTANCE MODULATOR; MU-M AB The authors describe an (InGaAl)As:GaAs vertical-cavity optical transmission modulator operating at 1.32 mu m, and having a single-pass contrast Delta T/T of 24% at < 5V bias. Device performance and yield have been improved, using a specially designed buffer that compensates for incomplete strain relaxation. RP Fritz, IJ (reprint author), SANDIA NATL LABS,POB 5800,ALBUQUERQUE,NM 87185, USA. NR 7 TC 1 Z9 1 U1 0 U2 0 PU IEE-INST ELEC ENG PI HERTFORD PA MICHAEL FARADAY HOUSE SIX HILLS WAY STEVENAGE, HERTFORD, ENGLAND SG1 2AY SN 0013-5194 J9 ELECTRON LETT JI Electron. Lett. PD OCT 10 PY 1996 VL 32 IS 21 BP 2010 EP 2012 DI 10.1049/el:19961354 PG 3 WC Engineering, Electrical & Electronic SC Engineering GA VM817 UT WOS:A1996VM81700054 ER PT J AU Connelly, MA Zhang, H Kieleczawa, J Anderson, CW AF Connelly, MA Zhang, H Kieleczawa, J Anderson, CW TI Alternate splice-site utilization in the gene for the catalytic subunit of the DNA-activated protein kinase, DNA-PKcs SO GENE LA English DT Article DE DNA double-strand break repair; V(D)J recombination; phosphatidylinositol kinase-related protein ID ATAXIA-TELANGIECTASIA GENE; STRAND-BREAK-REPAIR; V(D)J RECOMBINATION; PRODUCT; CELLS AB Analysis of polyA-selected RNAs and cDNA clones from several human cell lines revealed the presence of a 93-bp exon in the PI kinase homology region of DNA-PKcs that was not present in the cDNA sequence derived from HeLa cell cDNA clones. RT-PCR showed that most DNA-PKcs mRNAs in human cells have this exon. Thus, the nascent DNA-PKcs, polypeptide is composed of 4127 aa and has a predicted mel. wt. of 469 021 (470 kDa). C1 BROOKHAVEN NATL LAB,DEPT BIOL,UPTON,NY 11973. NR 17 TC 19 Z9 20 U1 0 U2 0 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0378-1119 J9 GENE JI Gene PD OCT 10 PY 1996 VL 175 IS 1-2 BP 271 EP 273 DI 10.1016/0378-1119(96)00135-7 PG 3 WC Genetics & Heredity SC Genetics & Heredity GA VR398 UT WOS:A1996VR39800043 PM 8917110 ER PT J AU Leger, A Mathez, EA Duba, A Pineau, F Ginsberg, S AF Leger, A Mathez, EA Duba, A Pineau, F Ginsberg, S TI Carbonaceous material in metamorphosed carbonate rocks from the Waits River Formation, NE Vermont, and its effect on electrical conductivity SO JOURNAL OF GEOPHYSICAL RESEARCH-SOLID EARTH LA English DT Article ID LOWER-CRUSTAL CONDUCTIVITY; GRAIN-BOUNDARY GRAPHITE; REGIONAL METAMORPHISM; NEW-ENGLAND; ISOTOPE GEOCHEMISTRY; FLUID INFILTRATION; CONTINENTAL-CRUST; EASTERN VERMONT; CALCITE; GRAPHITIZATION AB The relations among electrical conductivity and graphite content, metamorphic grade, and fluid:rock interaction are investigated for a suite of regionally metamorphosed graphitic carbonate rocks from the Waits River Formation, NE Vermont, Graphitization was complete by the lowest grade of metamorphism attained in the area (similar to 450 degrees C and 450 MPa). In low-grade rocks, graphite occurs as inclusions within calcite and along grain boundaries, and in medium-grade rocks, it concentrates near porphyroblasts. In neither suite does graphite form interconnected networks. Average reduced carbon abundances are 4400 and 2800 ppm for the low- and medium-grade rocks, respectively. High-grade rocks are almost void of graphite, except for one specimen, The delta(13)C values were determined for graphite and carbonates and delta(18)O values were determined for the carbonates and silicate residues. There is no change in isotopic values between low- and medium-grade rocks. In contrast, high-grade rocks show marked decreases in delta(13)C and delta(18)O values of similar to 4 parts per thousand compared to low- and medium-grade rocks. Both isotopic analyses and graphite depletion in high-grade rocks were caused by influx of large quantities of magmatic water during peak metamorphism, Electrical conductivity was measured in the laboratory on representative specimens. Rocks with high carbon content (>7000 ppm) from both the low- and high-grade zones display almost an order of magnitude higher electrical conductivity than expected from their fluid content alone. Graphite does not form an interconnected network in these rocks, yet it combines with the saline fluids to significantly increase electrical conductivities. C1 LAWRENCE LIVERMORE NATL LAB, DEPT EARTH SCI, LIVERMORE, CA 94550 USA. UNIV PARIS 07, LAB GEOCHIM ISOTOPES STABLES, IPGP, URA CNRS 1762, F-75251 PARIS, FRANCE. RP Leger, A (reprint author), AMER MUSEUM NAT HIST, DEPT EARTH & PLANETARY SCI, NEW YORK, NY 10024 USA. NR 73 TC 9 Z9 9 U1 0 U2 6 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 2169-9313 EI 2169-9356 J9 J GEOPHYS RES-SOL EA JI J. Geophys. Res.-Solid Earth PD OCT 10 PY 1996 VL 101 IS B10 BP 22203 EP 22214 DI 10.1029/96JB01757 PG 12 WC Geochemistry & Geophysics SC Geochemistry & Geophysics GA VM544 UT WOS:A1996VM54400024 ER PT J AU Nishiizumi, K Finkel, RC Klein, J Kohl, CP AF Nishiizumi, K Finkel, RC Klein, J Kohl, CP TI Cosmogenic production of Be-7 and Be-10 in water targets SO JOURNAL OF GEOPHYSICAL RESEARCH-SOLID EARTH LA English DT Article ID ACCELERATOR MASS-SPECTROMETRY; TERRESTRIAL ROCKS; PRODUCTION-RATES; SIERRA-NEVADA; EXPOSURE; INSITU; CL-36; RADIONUCLIDES; SAMPLES; AL-26 AB We have measured Be-10 (t(1/2)=1.5x10(6) years) and Be-7 (t(1/2)=53.28 days) concentrations in water targets exposed for 1 to 2 years at Echo Lake, Colorado (elevation=3246 m) and at La Jolla, California (140 m). Neutron monitor data were used to normalize the measured concentrations in order to calculate production rates equivalent to the cosmic ray flux averaged over four solar cycles (43 years). The Be-7 production rates thus obtained correspond to 6.03+/-0.07x10(-6) atom g(-1). O s(-1) at Echo Lake and 5.06+/-0.20x10(-7) atom g(-1). O s(-1) at La Jolla. The Be-10 production rates correspond to 3.14+/-0.18x10(-6) atom g(-1). Os-1 at Echo Lake and 2.68+/-0.47x10(-7) atom g(-1). Os-1 at La Jolla. When compared with Be-10 production rates determined in Be-10-saturated rocks from the Antarctic and with theoretical calculations based on meteorite and lunar sample data, we find that the million-year average production rate is about 14-17% greater than the present production rate averaged over the last four solar cycles. Comparison with production rates determined by measuring glacially polished rocks from the Sierra Nevada in California indicates that average production (based on a revised 13,000-year deglaciation age and a geographic latitude correction) is about 11% greater than the average over the last four solar cycles. The measured B-10/Be-7 production ratio in oxygen is 0.52+/-0.03 at Echo Lake and 0.55+/-0.07 at La Jolla. C1 LAWRENCE LIVERMORE NATL LAB, DIV EARTH SCI, LIVERMORE, CA 94551 USA. UNIV PENN, DEPT PHYS, PHILADELPHIA, PA 19104 USA. SAN DIEGO STATE UNIV, DEPT CHEM, LA JOLLA, CA 92093 USA. RP Nishiizumi, K (reprint author), UNIV CALIF BERKELEY, SPACE SCI LAB, GRIZZLY PEAK BLVD, BERKELEY, CA 94720 USA. NR 40 TC 47 Z9 49 U1 1 U2 5 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 2169-9313 EI 2169-9356 J9 J GEOPHYS RES-SOL EA JI J. Geophys. Res.-Solid Earth PD OCT 10 PY 1996 VL 101 IS B10 BP 22225 EP 22232 DI 10.1029/96JB02270 PG 8 WC Geochemistry & Geophysics SC Geochemistry & Geophysics GA VM544 UT WOS:A1996VM54400026 ER PT J AU Bromley, BC AF Bromley, BC TI Quasirandom number generators for parallel Monte Carlo algorithms SO JOURNAL OF PARALLEL AND DISTRIBUTED COMPUTING LA English DT Article AB A method for generating sequences of quasirandom numbers allows conventional serial Monte Carlo algorithms to be parallelized using a leapfrog scheme. Specifically, a Sobol' sequence can be broken up into interleaved subsets; with each processing node calculating a unique subset of the full sequence, all of the computational advantages of quasirandom Monte Carlo methods over pseudorandom algorithms or grid-based techniques are retained. Tests with several parallel supercomputers demonstrate that as many as 10(6) integration points (up to 6 dimensions) can be generated per second per node in the optimal case where the number of nodes is a power of 2. The speed of communication-free parallel Sobol' sequence generators and the rapid convergence properties of quasirandom Monte Carlo schemes indicate that the method described here may be gainfully applied to a wide range of problems. (C) 1996 Academic Press, Inc. RP Bromley, BC (reprint author), LOS ALAMOS NATL LAB,POB 1663,LOS ALAMOS,NM 87545, USA. NR 11 TC 17 Z9 17 U1 0 U2 0 PU ACADEMIC PRESS INC JNL-COMP SUBSCRIPTIONS PI SAN DIEGO PA 525 B ST, STE 1900, SAN DIEGO, CA 92101-4495 SN 0743-7315 J9 J PARALLEL DISTR COM JI J. Parallel Distrib. Comput. PD OCT 10 PY 1996 VL 38 IS 1 BP 101 EP 104 DI 10.1006/jpdc.1996.0132 PG 4 WC Computer Science, Theory & Methods SC Computer Science GA VV400 UT WOS:A1996VV40000009 ER PT J AU Mathis, JE Compton, RN Boyles, DC Pagni, RM AF Mathis, JE Compton, RN Boyles, DC Pagni, RM TI High resolution photoelectron spectroscopy of bromochlorofluoromethane SO MOLECULAR PHYSICS LA English DT Article AB High resolution He(I) photoelectron spectra are reported for a racemic mixture of bromochlorofluoromethane molecules. The samples were cooled using nozzle jet expansion of the pure gas. The adiabatic and vertical ionization potentials are determined to be 10.98 +/- 0.05 eV and 11.13 +/- 0.06 eV, respectively. C1 UNIV TENNESSEE,DEPT CHEM,KNOXVILLE,TN 37996. RP Mathis, JE (reprint author), OAK RIDGE NATL LAB,OAK RIDGE,TN 37831, USA. NR 24 TC 5 Z9 5 U1 2 U2 5 PU TAYLOR & FRANCIS LTD PI LONDON PA ONE GUNDPOWDER SQUARE, LONDON, ENGLAND EC4A 3DE SN 0026-8976 J9 MOL PHYS JI Mol. Phys. PD OCT 10 PY 1996 VL 89 IS 2 BP 505 EP 514 DI 10.1080/002689796173868 PG 10 WC Chemistry, Physical; Physics, Atomic, Molecular & Chemical SC Chemistry; Physics GA VM765 UT WOS:A1996VM76500011 ER PT J AU Drell, SD AF Drell, SD TI McGeorge Bundy (1919-96) - Obituary SO NATURE LA English DT Item About an Individual RP Drell, SD (reprint author), STANFORD LINEAR ACCELERATOR CTR,STANFORD,CA 94309, USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU MACMILLAN MAGAZINES LTD PI LONDON PA 4 LITTLE ESSEX STREET, LONDON, ENGLAND WC2R 3LF SN 0028-0836 J9 NATURE JI Nature PD OCT 10 PY 1996 VL 383 IS 6600 BP 483 EP 483 DI 10.1038/383483a0 PG 1 WC Multidisciplinary Sciences SC Science & Technology - Other Topics GA VL755 UT WOS:A1996VL75500027 ER PT J AU Behrenfeld, MJ Bale, AJ Kolber, ZS Aiken, J Falkowski, PG AF Behrenfeld, MJ Bale, AJ Kolber, ZS Aiken, J Falkowski, PG TI Confirmation of iron limitation of phytoplankton photosynthesis in the equatorial Pacific Ocean SO NATURE LA English DT Article ID SOUTHERN-OCEAN; FLUORESCENCE; PRODUCTIVITY; HYPOTHESIS AB THE eastern equatorial Pacific Ocean is one of only three open-ocean regions where low phytoplankton chlorophyll biomass persists despite perennially high nitrate and phosphate nutrient concentrations'. In 1993, an area within this region was artificially enriched with a single dose of soluble iron to test whether phytoplankton are physiologically prevented from utilizing the available nutrients by the low natural iron concentrations(2,3). Although photosynthesis was stimulated(4), the observed lack of a bloom or a significant decrease in nutrient concentrations could not he attributed unequivocally to zooplankton grazing(5-7), further iron limitation or secondary nutrient limitation(2,4). In 1995, a second iron-enrichment experiment (IronEx II) was conducted in which the same total dosage of iron was added, but over eight days(8). A massive phytoplankton bloom developed, significantly reducing surface-water nutrient and CO2 concentrations(8-10). Here we report in situ measurements of fluorescence during IronEx II, which shelf that the iron enrichment triggered biophysical alterations of the the phytoplankton's photosynthetic apparatus, resulting in increased photosynthetic capacities throughout the experiment and, hence, the observed bloom. These results unequivocally establish physiological limitation of phytoplankton by iron as the cause of the high-nitrate, low-chlorophyll phenomenon in this ocean region. C1 NERC, PLYMOUTH MARINE LAB, PLYMOUTH PL1 3DH, DEVON, ENGLAND. RP Behrenfeld, MJ (reprint author), BROOKHAVEN NATL LAB, DIV OCEANOG & ATMOSPHER SCI, UPTON, NY 11973 USA. RI Reboreda, Rosa/A-2518-2012 NR 31 TC 307 Z9 315 U1 5 U2 50 PU NATURE PUBLISHING GROUP PI LONDON PA MACMILLAN BUILDING, 4 CRINAN ST, LONDON N1 9XW, ENGLAND SN 0028-0836 J9 NATURE JI Nature PD OCT 10 PY 1996 VL 383 IS 6600 BP 508 EP 511 DI 10.1038/383508a0 PG 4 WC Multidisciplinary Sciences SC Science & Technology - Other Topics GA VL755 UT WOS:A1996VL75500044 ER PT J AU Vuchic, BV Merkle, KL Baldo, PM Dean, KA Buchholz, DB Chang, RPH Zhang, H Marks, LD AF Vuchic, BV Merkle, KL Baldo, PM Dean, KA Buchholz, DB Chang, RPH Zhang, H Marks, LD TI The formation, transport properties and microstructure of 45 degrees [001] grain boundaries induced by epitaxy modification in YBa2Cu3O7-x thin films SO PHYSICA C LA English DT Article DE grain boundaries; critical current density; electrical resistivity; HREM; thin films ID ORGANOMETALLIC BEAM EPITAXY; SINGLE-CRYSTAL MGO; WEAK LINKS; JUNCTIONS; GROWTH; INTERFACES; NUCLEATION; BICRYSTALS AB Tilt grain-boundary junctions with a 45 degrees [001] misorientation were formed in YBa2Cu3O7-x (YBCO) thin films grown by pulsed organometallic beam epitaxy on (100) MgO substrates. The junctions were introduced at predetermined locations due to a modification of the orientation relation between the thin film and substrate following a low-energy argon ion irradiation of specific areas of the substrate surface prior to film deposition. Rutherford backscatter spectrometry and certain surface Features observed by atomic force microscopy indicate that implantation of ions is necessary to cause the modified epitaxy. The low-temperature transport characteristics of individual isolated grain boundaries were determined by electromagnetic characterizations of the junction behavior. The same grain boundaries were examined by transmission electron microscopy and high-resolution electron microscopy and it was found that the boundaries are for the most part free of precipitates and well structured at the atomic scale. Regardless of the average grain boundary inclination, asymmetric (110)(100) facets dominate the microstructure of the junctions. Possible mechanisms for epitaxy modification and the transport properties in relation to the observed microstructure are discussed. C1 ARGONNE NATL LAB,DIV SCI MAT,ARGONNE,IL 60439. NORTHEASTERN UNIV,DEPT MAT SCI & ENGN,EVANSTON,IL 60208. RI Marks, Laurence/B-7527-2009; Chang, R.P.H/B-7505-2009 NR 41 TC 10 Z9 10 U1 0 U2 2 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0921-4534 J9 PHYSICA C JI Physica C PD OCT 10 PY 1996 VL 270 IS 1-2 BP 75 EP 90 DI 10.1016/0921-4534(96)00481-9 PG 16 WC Physics, Applied SC Physics GA VP361 UT WOS:A1996VP36100008 ER PT J AU Specht, ED Goyal, A Kroeger, DM MogroCampero, A Bednarczyk, PJ Tkaczyk, JE DeLuca, JA AF Specht, ED Goyal, A Kroeger, DM MogroCampero, A Bednarczyk, PJ Tkaczyk, JE DeLuca, JA TI Critical current, film thickness and grain alignment for spray-pyrolyzed films of TlBa2Ca2Cu3Ox SO PHYSICA C LA English DT Article ID CRITICAL-CURRENT-DENSITY; SUPERCONDUCTING FILMS; ALIGNED GRAINS; MICROSTRUCTURE; DEPENDENCE; TRANSPORT; COLONIES; TEXTURE; TAPES AB X-ray diffraction rocking curves are used to measure the c axis alignment of TlBa2Ca2Cu3Ox films grown on polycrystalline substrates with thickness varying from 3 to 10.5 mu m Films thicker than 3 mu m are found to contain two layers: a well aligned (3.5 degrees FWHM) bottom layer, and a poorly aligned (greater than 12 degrees FWHM) top layer. Azimuthal scans show that the component with good long-range out-of-plane alignment retains its characteristic colony microstructure of local in-plane alignment as film thickness increases. ?The length dependence of the critical current density may be accounted for by assuming that all the supercurrent is carried by the well-aligned component. C1 GE CO,CTR RES & DEV,SCHENECTADY,NY 12301. RP Specht, ED (reprint author), OAK RIDGE NATL LAB,OAK RIDGE,TN 37831, USA. RI Specht, Eliot/A-5654-2009 OI Specht, Eliot/0000-0002-3191-2163 NR 14 TC 9 Z9 9 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 OCT 10 PY 1996 VL 270 IS 1-2 BP 91 EP 96 DI 10.1016/0921-4534(96)00492-3 PG 6 WC Physics, Applied SC Physics GA VP361 UT WOS:A1996VP36100009 ER PT J AU Tetenbaum, M Hash, M Tani, BS Maroni, VA AF Tetenbaum, M Hash, M Tani, BS Maroni, VA TI Oxygen stoichiometry, phase stability, and thermodynamic behavior of the lead-doped and lead-free Bi-2212 systems SO PHYSICA C LA English DT Article ID MODULATED STRUCTURE; PARTIAL-PRESSURE; HEAT-TREATMENT; THIN-FILMS; SUPERCONDUCTOR; BI2SR2CA2CU3O10+DELTA; TEMPERATURE; SILVER; LIMITS; BI2SR2CA1CU2O8+DELTA AB Electromotive-force (EMF) measurements of oxygen fugacities as a function of stoichiometry have been made on lead-doped and lead-free Bi2-zPbzSr2Ca1Cu2Ox superconducting ceramics in the temperature range similar to 700-815 degrees C by means of an oxygen-titration technique that employs an yttria-stabilized zirconia electrolyte. Equations for the variation of oxygen partial pressure with composition and temperature have been derived from our EMF measurements. Thermodynamic assessments of the partial molar quantities and for lead-doped Bi-2212 and lead-free Bi-2212 indicate that the solid-state decomposition of these bismuth cuprates at low oxygen partial pressure can be represented by the diphasic CuO-Cu2O system. RP Tetenbaum, M (reprint author), ARGONNE NATL LAB,DIV CHEM TECHNOL,9700 S COSTS AVE,ARGONNE,IL 60439, USA. NR 38 TC 6 Z9 7 U1 6 U2 12 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0921-4534 J9 PHYSICA C JI Physica C PD OCT 10 PY 1996 VL 270 IS 1-2 BP 114 EP 128 DI 10.1016/0921-4534(96)00454-6 PG 15 WC Physics, Applied SC Physics GA VP361 UT WOS:A1996VP36100012 ER PT J AU Chae, MS Simnad, MT Maple, MB Anders, S Anders, A Brown, IG AF Chae, MS Simnad, MT Maple, MB Anders, S Anders, A Brown, IG TI Properties of cathodic arc deposited high-temperature superconducting composite thin films on Ag substrates SO PHYSICA C LA English DT Article DE high-temperature superconductor; Bi2212; thin film ID TRANSPORT AB High temperature superconducting composite thin films on Ag substrates were prepared by cathodic are deposition of alloy precursors. The deposition technique employed a cathode comprised of a precursor alloy for the vacuum are plasma source. The precursor alloy was prepared by multiple are-melting of mixed metallic constituents of the high-temperature superconducting material Bi2Sr2CaCu2Oy (Bi2212) and 50 wt.% of Ag. The presence of silver in the precursor alloy film was expected to allow accommodation of the lattice and thermal expansion mismatch between the oxidized film and the silver substrate. The as-deposited film could be formed to practically any desirable shape before being subjected to heat treatments. Following deposition, controlled oxidation of the precursor alloy thin film on the Ag substrate was performed to produce the superconducting composite on the silver substrate. After the heat treatment, the composite film consisted of Bi2212 highly c-axis oriented normal to the Ag substrate. C1 UNIV CALIF SAN DIEGO,INST PURE & APPL PHYS SCI,LA JOLLA,CA 92093. UNIV CALIF SAN DIEGO,SCH ENGN,MAT SCI PROGRAM,LA JOLLA,CA 92093. LAWRENCE LIVERMORE NATL LAB,BERKELEY,CA 94720. RI Anders, Andre/B-8580-2009; Raoux, Simone/G-3920-2016 OI Anders, Andre/0000-0002-5313-6505; NR 16 TC 5 Z9 5 U1 0 U2 2 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0921-4534 J9 PHYSICA C JI Physica C PD OCT 10 PY 1996 VL 270 IS 1-2 BP 173 EP 179 DI 10.1016/0921-4534(96)00504-7 PG 7 WC Physics, Applied SC Physics GA VP361 UT WOS:A1996VP36100019 ER PT J AU Srivastava, DK Sinha, B Awes, TC AF Srivastava, DK Sinha, B Awes, TC TI Photon pairs from relativistic heavy ion collisions and the quark hadron phase transition SO PHYSICS LETTERS B LA English DT Article DE relativistic heavy ion collisions; quark gluon plasma; photon pairs; quark annihilation; pion annihilation; kaon annihilation; hydrodynamics; transverse expansion ID GAMMA-GAMMA-PAIRS; ULTRARELATIVISTIC NUCLEAR COLLISIONS; GLUON PLASMA; DILEPTON EMISSION; MATTER; RATES AB A search for photon pairs produced from the annihilation of quarks and of pions in relativistic heavy ion collisions may provide confirmation of a quark hadron phase transition. If there is no phase transition, the resulting high temperatures could lead to a much larger production of large mass pairs from pion annihilation, and may even carry a clear signature of kaon annihilation. C1 SAHA INST NUCL PHYS,CALCUTTA 700064,W BENGAL,INDIA. OAK RIDGE NATL LAB,OAK RIDGE,TN 37831. RP Srivastava, DK (reprint author), BHABHA ATOM RES CTR,CTR VARIABLE ENERGY CYCLOTRON,1-AF BIDHAN NAGAR,CALCUTTA 700064,W BENGAL,INDIA. NR 18 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 OCT 10 PY 1996 VL 387 IS 1 BP 21 EP 25 DI 10.1016/0370-2693(96)00977-X PG 5 WC Astronomy & Astrophysics; Physics, Nuclear; Physics, Particles & Fields SC Astronomy & Astrophysics; Physics GA VM139 UT WOS:A1996VM13900004 ER PT J AU Schuler, GA Vogt, R AF Schuler, GA Vogt, R TI Systematics of quarkonium production SO PHYSICS LETTERS B LA English DT Article ID PI-N INTERACTIONS; BERYLLIUM COLLISIONS; PROTON; J/PSI; HADROPRODUCTION; POLARIZATION; COPPER; GEV/C; TEV AB Quarkonium production in high-energy reactions is found to exhibit a behaviour more universal than that expected from velocity scaling, Total rates of quarkonia produced in hadronic interactions as well as Feynman-x and transverse momentum distributions can be described over the full range of accessible energies (15 less than or similar to root s less than or similar to 1800 GeV) by two-stage processes. The quarkonium production cross section factors into a process-dependent short-distance part and a single long-distance matrix element. The first part describing the production of a free quark-antiquark pair is the peturbatively calculated subthreshold cross section. The non-perturbative factor turns out to be universal, giving the model great predictive power. Furthermore we estimate the fraction of the heavy-quark cross section leading to quarkonium for both the charm and bottom systems. Finally, we comment on quarkonium photoproduction. C1 UNIV CALIF BERKELEY,LAWRENCE BERKELEY NATL LAB,DIV NUCL SCI,BERKELEY,CA 94720. UNIV CALIF DAVIS,DEPT PHYS,DAVIS,CA 95616. RP Schuler, GA (reprint author), CERN,DIV THEORY,CH-1211 GENEVA 23,SWITZERLAND. NR 41 TC 59 Z9 59 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 OCT 10 PY 1996 VL 387 IS 1 BP 181 EP 186 DI 10.1016/0370-2693(96)00999-9 PG 6 WC Astronomy & Astrophysics; Physics, Nuclear; Physics, Particles & Fields SC Astronomy & Astrophysics; Physics GA VM139 UT WOS:A1996VM13900029 ER PT J AU Parke, S Shadmi, Y AF Parke, S Shadmi, Y TI Spin correlations in top-quark pair production at e(+)e(-) colliders SO PHYSICS LETTERS B LA English DT Article ID CP VIOLATION; POLARIZATION; PREDICTIONS; DECAY AB We show that top-quark pairs are produced in an essentially unique spin configuration in polarized e(+)e(-) colliders at all energies above the threshold region. Since the directions of the electroweak decay products of polarized top-quarks are strongly correlated to the top-quark spin axis, this unique spin configuration leads to a distinctive topology for top-quark pair events which can be used to constrain anomalous couplings to the top-quark. A significant interference effect between the longitudinal and transverse W-bosons in the decay of polarized top-quarks is also discussed. These results are obtained at leading order in perturbation theory but radiative corrections are expected to be small. RP Parke, S (reprint author), FERMILAB NATL ACCELERATOR LAB,DEPT THEORET PHYS,POB 500,BATAVIA,IL 60510, USA. NR 22 TC 102 Z9 103 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 OCT 10 PY 1996 VL 387 IS 1 BP 199 EP 206 DI 10.1016/0370-2693(96)00998-7 PG 8 WC Astronomy & Astrophysics; Physics, Nuclear; Physics, Particles & Fields SC Astronomy & Astrophysics; Physics GA VM139 UT WOS:A1996VM13900033 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 Reaction of hydrogen with S/Mo(110) and MoSx films: Formation of hydrogen sulfide SO SURFACE SCIENCE LA English DT Article DE catalysis; hydrogen; hydrogen sulphide; molybdenum; sulphides; surface chemical reaction; thermal desorption spectroscopy; X-ray photoelectron spectroscopy ID PHASE ATOMIC-HYDROGEN; HYDRODESULFURIZATION ACTIVITY; ELECTRONIC-PROPERTIES; PROMOTED SULFIDATION; MOLYBDENUM SULFIDE; METAL SULFIDES; SULFUR; ADSORPTION; MO(110); CATALYSTS AB The reaction of hydrogen (H-2, D-2, or D) with sulfur multilayers, S-<1/Mo(110), surfaces and MoSx films has been investigated at temperatures between 100 and 400 K. All the surfaces were unreactive toward molecular hydrogen under UHV conditions. However, these systems showed a large reactivity toward atomic hydrogen. As gas-phase hydrogen atoms impinged on the surfaces, gaseous hydrogen sulfide was formed. This reaction was very effective for the removal of sulfur atoms from sulfur multilayers and MoSx films. On MoSx films the 2D(gas) + S(solid) --> D2S(gas) reaction was 3-4 times slower than on sulfur multilayers, and at least 6 times faster than on S-<1/Mo(110) surfaces. A good correlation was found between the rate of formation of gaseous hydrogen sulfide and the stability of the S-S or S-Mo bonds in a surface. The bonding interactions between hydrogen sulfide and S-0.9-0.6/Mo(110) or MoSx were negligible at temperatures above 200 K. Rough MoSx films that exposed unsaturated molybdenum sites were more reactive toward hydrogen sulfide than the sulfur-basal plane of MoSx or S-0.9-0.6/Mo(110) surfaces. The behavior of molybdenum sulfide catalysts in hydrogenation and hydrodesulfurization processes is discussed in light of these results. C1 BROOKHAVEN NATL LAB,DEPT CHEM,UPTON,NY 11973. NATL UNIV SINGAPORE,DEPT CHEM,SINGAPORE 1192600,SINGAPORE. RI Xu, Guo Qin/C-2077-2013; Hrbek, Jan/I-1020-2013 NR 50 TC 46 Z9 46 U1 1 U2 5 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0039-6028 J9 SURF SCI JI Surf. Sci. PD OCT 10 PY 1996 VL 366 IS 1 BP 29 EP 42 DI 10.1016/0039-6028(96)00802-3 PG 14 WC Chemistry, Physical; Physics, Condensed Matter SC Chemistry; Physics GA VK470 UT WOS:A1996VK47000005 ER PT J AU Chen, XG Li, PS Holtz, JSW Chi, ZH Pajcini, V Asher, SA Kelly, LA AF Chen, XG Li, PS Holtz, JSW Chi, ZH Pajcini, V Asher, SA Kelly, LA TI Resonance Raman examination of the electronic excited states of glycylglycine and other dipeptides: Observation of a carboxylate->amide charge transfer transition SO JOURNAL OF THE AMERICAN CHEMICAL SOCIETY LA English DT Article ID VIBRATIONAL CIRCULAR-DICHROISM; III SPECTRAL REGION; N-METHYLACETAMIDE; PEPTIDE-BOND; UVRR SPECTROSCOPY; AMIDE; CONFORMATION; ENHANCEMENT; PROTOPORPHYRIN; ASSIGNMENTS AB We have examined the UV resonance Raman and the VUV absorption spectra of aqueous glycylglycine and other dipeptides. We observe strong resonance Raman enhancement of the amide I, II, and III bands and the amide CalphaH bending mode in a manner similar to that we observed previously with excitation within the pi-->pi* transition of N-methylacetamide (Chen, X. G.; Asher, S. A.; Schweitzer-Stenner, R.; Mirkin, N. G.; Krimm, S. J. Am. Chem. Soc. 1995, 117, 2884). However, in addition, we observe strong resonance Raman enhancement of the ca. 1400 cm(-1) symmetric COO- stretching vibration, whose 206.5 mm Raman cross section is increased 20-fold compared to that of the carboxylate in sodium acetate, for example. Addition of a methylene spacer between the amide and carboxylate groups causes the resonance Raman enhancement of this symmetric COO- stretch to disappear. The UV resonance Raman excitation profiles, the Raman depolarization ratio dispersion, and the VUV absorption spectra of glycylglycine and other dipeptides demonstrate the existence of a new 197 nm charge transfer band which involves electron transfer from a nonbonding carboxylate orbital to the amide-like pi* orbital. This transition occurs at the penultimate carboxylate end of all peptides and proteins. C1 UNIV PITTSBURGH,DEPT CHEM,PITTSBURGH,PA 15260. BROOKHAVEN NATL LAB,DEPT BIOL,UPTON,NY 11973. NR 64 TC 43 Z9 45 U1 7 U2 14 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 SN 0002-7863 J9 J AM CHEM SOC JI J. Am. Chem. Soc. PD OCT 9 PY 1996 VL 118 IS 40 BP 9705 EP 9715 DI 10.1021/ja960421+ PG 11 WC Chemistry, Multidisciplinary SC Chemistry GA VL586 UT WOS:A1996VL58600031 ER PT J AU Hu, XH Frei, H Spiro, TG AF Hu, XH Frei, H Spiro, TG TI Nanosecond step-scan FTIR spectroscopy of hemoglobin: Ligand recombination and protein conformational changes SO BIOCHEMISTRY LA English DT Article ID INFRARED DIFFERENCE SPECTROSCOPY; ABSORPTION-SPECTROSCOPY; CARBON-MONOXIDE; BACTERIORHODOPSIN; CARBONMONOXYMYOGLOBIN; COOPERATIVITY; PROTONATION; MECHANISMS; MEMBRANE; SPECTRA AB Step-scan FTIR spectroscopy with nanosecond time resolution is applied to the photocycle of carbonmonoxy hemoglobin (HbCO). The strong CO stretching band at 1951 cm(-1) serves as a convenient monitor of the state of ligation. Both geminate and second-order phases of CO recombination occur at rates which are in excellent agreement with previous visible absorption measurements, showing the molecular mechanisms to be unperturbed by the high protein concentrations (6.7 mM in heme) required for adequate protein signals. While the extent of photolysis (43%) was insufficient to drive the R-->T quaternary transition, the protein TRIR (time-resolved infrared) difference bands (1250-1700 cm(-1)) nevertheless reveal interesting tertiary dynamics. Most of the bands are fully developed at very early times, possibly preceding the geminate recombination phase (tau = 50 ns). Some bands arise more slowly, however, with a time constant of 0.4 mu s, reflecting a tertiary motion which is coincident with a quaternary motion previously detected by ultraviolet resonance Raman spectroscopy of fully photolyzed HbCO. Relaxation of the TRIP bands is either faster (tau = similar to 90 mu s) or slower (tau = similar to 250 mu s) than CO rebinding (effective time constant of 160 mu s), ring either a distribution of tertiary processes or a chain inequivalence in CO rebinding. C1 PRINCETON UNIV,DEPT CHEM,PRINCETON,NJ 08544. UNIV CALIF BERKELEY,LAWRENCE BERKELEY LAB,STRUCT BIOL DIV,BERKELEY,CA 94720. FU NIGMS NIH HHS [GM 25158] NR 32 TC 42 Z9 43 U1 0 U2 14 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 SN 0006-2960 J9 BIOCHEMISTRY-US JI Biochemistry PD OCT 8 PY 1996 VL 35 IS 40 BP 13001 EP 13005 DI 10.1021/bi961522n PG 5 WC Biochemistry & Molecular Biology SC Biochemistry & Molecular Biology GA VL663 UT WOS:A1996VL66300002 PM 8855934 ER PT J AU Race, HL Hind, G AF Race, HL Hind, G TI A protein kinase in the core of photosystem II SO BIOCHEMISTRY LA English DT Article ID THYLAKOID MEMBRANES; POLYPHENOL OXIDASE; LHCII KINASE; PHOSPHORYLATION; SPINACH; COMPLEX; POLYPEPTIDE; BINDING AB In green plants, several intrinsic protein components of the photosystem II (PS II) complexes are subject to reversible phosphorylation on threonine residues. Evidence from mutant and inhibitor studies indicates that multiple kinases are involved. The protein kinases appear to be membrane-bound and redox-regulated, with activity requiring reducing conditions, We report the identification of a protein kinase activity which copurifies with a core complex of PS II and is capable of phosphorylating the photosystem proteins and associated light-harvesting complex. The enzyme is a distinct and novel protein whose close proximity to the photosystem reaction center is confirmed by its rapid inactivation under strong red light irradiation in the presence of oxygen. C1 BROOKHAVEN NATL LAB,DEPT BIOL,UPTON,NY 11973. NR 31 TC 31 Z9 32 U1 0 U2 1 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 SN 0006-2960 J9 BIOCHEMISTRY-US JI Biochemistry PD OCT 8 PY 1996 VL 35 IS 40 BP 13006 EP 13010 DI 10.1021/bi961809k PG 5 WC Biochemistry & Molecular Biology SC Biochemistry & Molecular Biology GA VL663 UT WOS:A1996VL66300003 PM 8855935 ER PT J AU Knight, LB Hill, D Berry, K Babb, R Feller, D AF Knight, LB Hill, D Berry, K Babb, R Feller, D TI Electron spin resonance rare gas matrix studies of (CO2-)-C-12, (CO2-)-C-13, and (CO2-)-O-17: Comparison with ab initio calculations SO JOURNAL OF CHEMICAL PHYSICS LA English DT Article ID CONFIGURATION-INTERACTION CALCULATIONS; MOLECULAR WAVE-FUNCTIONS; MAGNETIC HYPERFINE PARAMETERS; NEON MATRICES; BENCHMARK CALCULATIONS; LASER VAPORIZATION; CATION RADICALS; THEORETICAL CALCULATIONS; PARAMAGNETIC-RESONANCE; SYSTEMATIC SEQUENCES AB The (CO2-)-C-12-O-16, (CO2-)-C-13-O-16, (CO2-)-C-12-O-17, and (CO2-)-C-12-O-16,17 radical anions have been generated by four independent methods and isolated in neon and argon matrices for detailed ESR (electron spin resonance) investigations, Included with these experimental measurements for the various magnetic parameters of CO2- are high level ab initio calculations (MR SD-CI and others) of the C-13 and O-17 hyperfine A tensors. Some of the calculations included the effects of a 42-atom neon cage on the electronic structure of CO2-. Previous ESR studies of CO2- have been conducted in more perturbing environments, such as ionic crystals, where the close proximity of the counter cation can alter the anion's properties. A comparison of the earlier measurements in more interactive materials with these theoretical and rare gas matrix results reveals a significantly different distribution of the spin density. The neon magnetic parameters (MHz) for CO2- are g(x)=2.0018, g(y)=1.9964, g(z)=2.0010; for C-13, A(x)=320.4, A(y)=296.1, A(z)=394.5; for O-17, A(x)=-81.6, A(y)=-174.9 and A(z)=-151.8. The argon results are similar to these neon values; isotropic spectra in argon were also observed at elevated temperatures that yielded g(iso) and A(iso) parameters consistent with the low temperature (4 K) anisotropic spectra. (C) 1996 American Institute of Physics. C1 PACIFIC NW NATL LAB,ENVIRONM MOL SCI LAB,RICHLAND,WA 99352. RP Knight, LB (reprint author), FURMAN UNIV,DEPT CHEM,GREENVILLE,SC 29613, USA. NR 83 TC 12 Z9 12 U1 0 U2 1 PU AMER INST PHYSICS PI WOODBURY PA CIRCULATION FULFILLMENT DIV, 500 SUNNYSIDE BLVD, WOODBURY, NY 11797-2999 SN 0021-9606 J9 J CHEM PHYS JI J. Chem. Phys. PD OCT 8 PY 1996 VL 105 IS 14 BP 5672 EP 5686 DI 10.1063/1.472456 PG 15 WC Chemistry, Physical; Physics, Atomic, Molecular & Chemical SC Chemistry; Physics GA VL696 UT WOS:A1996VL69600003 ER PT J AU Mordaunt, DH Osborn, DL Choi, H Bise, RT Neumark, DM AF Mordaunt, DH Osborn, DL Choi, H Bise, RT Neumark, DM TI Ultraviolet photodissociation of the HCCO radical studied by fast radical beam photofragment translational spectroscopy SO JOURNAL OF CHEMICAL PHYSICS LA English DT Article ID LASER-INDUCED FLUORESCENCE; O+C2H2(C2D2) REACTION; BRANCHING RATIO; KETENYL; CONSTANTS AB The ultraviolet photolysis of jet-cooled mass-selected ketenyl radicals has been investigated using the technique of fast radical beam photofragment translational spectroscopy. The (C) over tilde(2) Pi((2)A '')-(X) over tilde(2)A '' photofragment yield cross section spans 33400-48000 cm(-1) and exhibits resolved resonances and broad continua. Dissociation produces both ground and excited state CW radicals in association with ground state CO fragments; there is no evidence for H atom elimination. Analysis of the photofragment kinetic energy release spectra yield a value for the C-C bond dissociation energy and heat of formation of HCCO: D-0(HC-CO)=3.14+/-0.03 eV (72.4+/-0.7 kcal/mol) and Delta H-f,0(0)(HCCO)=1.82+/-0.03 eV (42.0+/-0.7 kcal/mol). (C) 1996 American Institute of Physics. C1 UNIV CALIF BERKELEY,LAWRENCE BERKELEY NATL LAB,DIV CHEM SCI,BERKELEY,CA 94720. RP Mordaunt, DH (reprint author), UNIV CALIF BERKELEY,DEPT CHEM,BERKELEY,CA 94720, USA. RI Osborn, David/A-2627-2009; Neumark, Daniel/B-9551-2009 OI Neumark, Daniel/0000-0002-3762-9473 NR 29 TC 46 Z9 47 U1 1 U2 4 PU AMER INST PHYSICS PI WOODBURY PA CIRCULATION FULFILLMENT DIV, 500 SUNNYSIDE BLVD, WOODBURY, NY 11797-2999 SN 0021-9606 J9 J CHEM PHYS JI J. Chem. Phys. PD OCT 8 PY 1996 VL 105 IS 14 BP 6078 EP 6081 DI 10.1063/1.472446 PG 4 WC Chemistry, Physical; Physics, Atomic, Molecular & Chemical SC Chemistry; Physics GA VL696 UT WOS:A1996VL69600046 ER PT J AU Miller, WH AF Miller, WH TI Comparison of positive flux operators for transition state theory using a solvable model - Comment SO JOURNAL OF CHEMICAL PHYSICS LA English DT Letter C1 UNIV CALIF BERKELEY,LAWRENCE BERKELEY NATL LAB,DIV CHEM SCI,BERKELEY,CA 94720. RP Miller, WH (reprint author), UNIV CALIF BERKELEY,DEPT CHEM,BERKELEY,CA 94720, USA. NR 2 TC 0 Z9 0 U1 0 U2 0 PU AMER INST PHYSICS PI WOODBURY PA CIRCULATION FULFILLMENT DIV, 500 SUNNYSIDE BLVD, WOODBURY, NY 11797-2999 SN 0021-9606 J9 J CHEM PHYS JI J. Chem. Phys. PD OCT 8 PY 1996 VL 105 IS 14 BP 6090 EP 6090 DI 10.1063/1.472937 PG 1 WC Chemistry, Physical; Physics, Atomic, Molecular & Chemical SC Chemistry; Physics GA VL696 UT WOS:A1996VL69600050 ER PT J AU Kim, Y Erbil, A Boatner, LA AF Kim, Y Erbil, A Boatner, LA TI Substrate dependence in the growth of epitaxial Pb1-xLaxTiO3 thin films SO APPLIED PHYSICS LETTERS LA English DT Article AB The metalorganic chemical vapor deposition (MOCVD) technique has been applied to the growth of epitaxial Pb1-xLaxTiO3 (PLT) thin films with x=0.28. By first introducing an initial TiO2 layer, three-dimensional epitaxial PLT films were grown on the (100) surface of MgO substrate. For both KTaO3 (100) and Al2O3 (0001) substrates, heteroepitaxy was achieved without the introduction of TiO2 as the initial, intervening layer between the PLT film and the substrate. On Al2O3 substrates, PLT films with a [111] preferred orientation were grown with a good epitaxial in-plane relationship. (C) 1996 American Institute of Physics. C1 GEORGIA INST TECHNOL,SCH PHYS,ATLANTA,GA 30332. OAK RIDGE NATL LAB,DIV SOLID STATE,OAK RIDGE,TN 37831. RI Boatner, Lynn/I-6428-2013 OI Boatner, Lynn/0000-0002-0235-7594 NR 8 TC 7 Z9 7 U1 0 U2 0 PU AMER INST PHYSICS PI WOODBURY PA CIRCULATION FULFILLMENT DIV, 500 SUNNYSIDE BLVD, WOODBURY, NY 11797-2999 SN 0003-6951 J9 APPL PHYS LETT JI Appl. Phys. Lett. PD OCT 7 PY 1996 VL 69 IS 15 BP 2187 EP 2189 DI 10.1063/1.117160 PG 3 WC Physics, Applied SC Physics GA VL184 UT WOS:A1996VL18400013 ER PT J AU Davids, PS Kogan, SM Parker, ID Smith, DL AF Davids, PS Kogan, SM Parker, ID Smith, DL TI Charge injection in organic light-emitting diodes: Tunneling into low mobility materials SO APPLIED PHYSICS LETTERS LA English DT Article AB We present device model calculations for the current-voltage (I-V) characteristics of organic diodes and compare them with measurements of structures fabricated using MEH-PPV. The measured I-V characteristics have a Fowler-Nordheim (FN) functional form, but are more than three orders of magnitude smaller than the calculated FN tunneling current. We find that the low mobility of the organic materials leads to a large backflow of injected carriers into the injecting contact. These results account for the experimental observations and also demonstrate how transport layers in multilayer organic light-emitting diodes can be used to improve carrier injection. RP Davids, PS (reprint author), LOS ALAMOS NATL LAB,LOS ALAMOS,NM 87545, USA. RI Davids, Paul/D-1550-2010 NR 10 TC 92 Z9 97 U1 0 U2 12 PU AMER INST PHYSICS PI WOODBURY PA CIRCULATION FULFILLMENT DIV, 500 SUNNYSIDE BLVD, WOODBURY, NY 11797-2999 SN 0003-6951 J9 APPL PHYS LETT JI Appl. Phys. Lett. PD OCT 7 PY 1996 VL 69 IS 15 BP 2270 EP 2272 DI 10.1063/1.117530 PG 3 WC Physics, Applied SC Physics GA VL184 UT WOS:A1996VL18400041 ER PT J AU White, CW Budai, JD Zhu, JG Withrow, SP Aziz, MJ AF White, CW Budai, JD Zhu, JG Withrow, SP Aziz, MJ TI Ion beam synthesis and stability of GaAs nanocrystals in silicon (vol 68, pg 2389, 1996) SO APPLIED PHYSICS LETTERS LA English DT Correction, Addition ID IMPLANTATION C1 HARVARD UNIV,CAMBRIDGE,MA 02138. RP White, CW (reprint author), OAK RIDGE NATL LAB,POB 2008,OAK RIDGE,TN 37831, USA. RI Budai, John/R-9276-2016 OI Budai, John/0000-0002-7444-1306 NR 5 TC 1 Z9 1 U1 0 U2 0 PU AMER INST PHYSICS PI WOODBURY PA CIRCULATION FULFILLMENT DIV, 500 SUNNYSIDE BLVD, WOODBURY, NY 11797-2999 SN 0003-6951 J9 APPL PHYS LETT JI Appl. Phys. Lett. PD OCT 7 PY 1996 VL 69 IS 15 BP 2297 EP 2297 DI 10.1063/1.117539 PG 1 WC Physics, Applied SC Physics GA VL184 UT WOS:A1996VL18400050 ER PT J AU Chang, JJ Warnor, BE AF Chang, JJ Warnor, BE TI Laser-plasma interaction during visible-laser ablation of methods (vol 69, pg 473, 1996) SO APPLIED PHYSICS LETTERS LA English DT Correction, Addition RP Chang, JJ (reprint author), LAWRENCE LIVERMORE NATL LAB,POB 808,M-S L-463,LIVERMORE,CA 94551, USA. NR 1 TC 2 Z9 2 U1 0 U2 0 PU AMER INST PHYSICS PI WOODBURY PA CIRCULATION FULFILLMENT DIV, 500 SUNNYSIDE BLVD, WOODBURY, NY 11797-2999 SN 0003-6951 J9 APPL PHYS LETT JI Appl. Phys. Lett. PD OCT 7 PY 1996 VL 69 IS 15 BP 2298 EP 2298 DI 10.1063/1.118158 PG 1 WC Physics, Applied SC Physics GA VL184 UT WOS:A1996VL18400051 ER PT J AU Khazeni, K Jia, YX Crespi, VH Lu, L Zettl, A Cohen, ML AF Khazeni, K Jia, YX Crespi, VH Lu, L Zettl, A Cohen, ML TI Pressure dependence of the resistivity and magnetoresistance in single-crystal Nd0.62Pb0.30MnO3-delta SO JOURNAL OF PHYSICS-CONDENSED MATTER LA English DT Article ID GIANT MAGNETORESISTANCE; THIN-FILMS; DOUBLE-EXCHANGE; LA1-XSRXMNO3; TEMPERATURE; TRANSPORT; OXIDE AB We have measured the resistivity and magnetoresistance of single-crystal Nd0.62Pb0.30MnO3-delta as a function of hydrostatic pressure up to 12 kbar. The pressure dependence of the resistivity at temperatures near the metal-insulator transition exceeds d(ln rho)/dP similar to 3 kbar(-1), greater than that observed in the normal state of high-temperature superconductors. The extreme pressure sensitivity of the resistivity below the transition temperature provides evidence that the low-temperature phase is not a simple metal. The metal-insulator transition temperature T-MI decreases by 2.6 K kbar(-1), in accord with an expectation for greater pressure sensitivity in lower-doped materials with lower T-MI. The peak magnetoresistance defined as [rho(0 T) - rho(7 T)]/rho(7 T) decreases with increasing pressure as the metal-insulator transition becomes less abrupt. The influence of thermal expansion upon the resistivity is expected to be large. C1 UNIV CALIF BERKELEY,LAWRENCE BERKELEY NATL LAB,DIV MAT SCI,BERKELEY,CA 94720. RP Khazeni, K (reprint author), UNIV CALIF BERKELEY,DEPT PHYS,BERKELEY,CA 94720, USA. RI Zettl, Alex/O-4925-2016; OI Zettl, Alex/0000-0001-6330-136X; Crespi, Vincent/0000-0003-3846-3193 NR 35 TC 9 Z9 9 U1 0 U2 1 PU IOP PUBLISHING LTD PI BRISTOL PA TECHNO HOUSE, REDCLIFFE WAY, BRISTOL, ENGLAND BS1 6NX SN 0953-8984 J9 J PHYS-CONDENS MAT JI J. Phys.-Condes. Matter PD OCT 7 PY 1996 VL 8 IS 41 BP 7723 EP 7731 DI 10.1088/0953-8984/8/41/017 PG 9 WC Physics, Condensed Matter SC Physics GA VL956 UT WOS:A1996VL95600018 ER PT J AU Petkov, MP Lynn, KG Roellig, LO AF Petkov, MP Lynn, KG Roellig, LO TI Water-induced effects on the positron moderation efficiency of rare gas solids SO JOURNAL OF PHYSICS-CONDENSED MATTER LA English DT Letter ID SLOW POSITRONS AB The first systematic study of the effect of impurities an the positron moderation efficiency of rare gas solids (RGS) is presented. Water contamination in the RGS decreased the moderation efficiency, already observed at the ppb level. A sub-monolayer (similar to 0.1 L) of water on the surface, however, enhances the positron yield by (up to) a factor of 2.1 for Ar and 1.3 for Kr. We explain these observations with changes in the positron affinity, induced by the water dipoles, and suggest further experiments to improve the performance of the RGS. C1 BROOKHAVEN NATL LAB,DEPT PHYS,UPTON,NY 11973. BULGARIAN ACAD SCI,INST NUCL RES & NUCL ENERGY,BU-1184 SOFIA,BULGARIA. CUNY CITY COLL,NEW YORK,NY 10031. NR 9 TC 4 Z9 4 U1 0 U2 0 PU IOP PUBLISHING LTD PI BRISTOL PA TECHNO HOUSE, REDCLIFFE WAY, BRISTOL, ENGLAND BS1 6NX SN 0953-8984 J9 J PHYS-CONDENS MAT JI J. Phys.-Condes. Matter PD OCT 7 PY 1996 VL 8 IS 41 BP L611 EP L615 DI 10.1088/0953-8984/8/41/003 PG 5 WC Physics, Condensed Matter SC Physics GA VL956 UT WOS:A1996VL95600003 ER PT J AU Ozawa, A Tanihata, I Kobayashi, T Sugahara, Y Yamakawa, O Omata, K Sugimoto, K Olson, D Christie, W Wieman, H AF Ozawa, A Tanihata, I Kobayashi, T Sugahara, Y Yamakawa, O Omata, K Sugimoto, K Olson, D Christie, W Wieman, H TI Interaction cross sections and radii of light nuclei SO NUCLEAR PHYSICS A LA English DT Article DE Be-9, C, Al-27(B-15,B-15); Be-9, C, Al-27(C-9,C-9); Be-9, C, Al-27(C-10,C-10); Be-9, C, Al-27(C-15,C-15); Be-9, C, Al-27(N-13,N-13); Be-9, C, Al-27(O-13,O-13); Be-9, C, Al-27(O-14,O-14); Be-9, C, Al-27(O-15,O-15); E similar to 730 MeV/nucleon; measured interaction sigma; B-15; C-9,C-10,C-15; N-13; O-13,O-14,O-15 deduced effective radii ID DENSITY-DISTRIBUTION; HALO; ISOTOPES AB The interaction cross sections (sigma(I)'s) with B-15, C-9, C-10, C-15, N-13, O-13, O-14 and O-15 beams have been measured at energies of around 730A . MeV. The effective root-mean-square (RMS) radii of the nucleon distribution of these nuclei have been deduced using a Glauber-model calculation. The global isotope and isospin dependences of the radii are shown in the p-shell region, The sigma(I)'s are also compared with those obtained at intermediate energies in the region. Furthermore, we calculated the Coulomb-energy differences of the mirror pairs deduced from the RMS charge radii and compared them with those obtained from the mass for some mirror pairs, From the above systematics, an anomalous nuclear structure (a halo and/or a skin) is suggested for B-14 and C-15, and the occurrence of an s-d inversion is emphasized for the Ne-17-N-17 mirror pair. C1 FUKUI UNIV,FAC EDUC,FUKUI 910,JAPAN. UNIV TOKYO,INST NUCL STUDY,TANASHI,TOKYO 188,JAPAN. OSAKA UNIV,FAC SCI,TOYONAKA,OSAKA 560,JAPAN. LAWRENCE BERKELEY LAB,BERKELEY,CA 94720. RP Ozawa, A (reprint author), RIKEN,INST PHYS & CHEM RES,WAKO,SAITAMA 35101,JAPAN. NR 24 TC 100 Z9 103 U1 2 U2 4 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 OCT 7 PY 1996 VL 608 IS 1 BP 63 EP 76 DI 10.1016/0375-9474(96)00241-2 PG 14 WC Physics, Nuclear SC Physics GA VM366 UT WOS:A1996VM36600005 ER PT J AU Wang, XH Yu, CH Cullen, DM Bryan, DC Devlin, M Fitch, MJ GalindoUribarri, A Gray, RW Herrick, DM Ibbotson, RW Kurz, KL Mullins, S Pilotte, S Radford, DC Satteson, MR Simon, MW Ward, D Wu, CY Yao, LH AF Wang, XH Yu, CH Cullen, DM Bryan, DC Devlin, M Fitch, MJ GalindoUribarri, A Gray, RW Herrick, DM Ibbotson, RW Kurz, KL Mullins, S Pilotte, S Radford, DC Satteson, MR Simon, MW Ward, D Wu, CY Yao, LH TI High-spin states in odd-odd Lu-164 SO NUCLEAR PHYSICS A LA English DT Article DE Sm-149(F-19,4n); E = 85 MeV; Nd-146(Na-23,5n); E = 110 MeV; measured E(gamma); I-gamma; gamma gamma-coin; Lu-164 deduced high-spin levels; I; pi; gamma-branching; B(M1)/B(E2) ratios; band crossings; signature inversion; neutron-proton interactions ID SIGNATURE INVERSION; ELECTROMAGNETIC PROPERTIES; BAND CROSSINGS; TRANSITION-PROBABILITIES; NUCLEAR-STRUCTURE; ROTATIONAL BANDS; ALIGNED BANDS; YRAST; SPECTROSCOPY; DEFORMATION AB High-spin states in odd-odd Lu-164 have been studied using F-19 and Na-13 induced fusion-evaporation reactions, Three strongly coupled rotational bands have been established and three decoupled bands were tentatively assigned to Lu-164. The band crossing frequencies, energy signature splittings, and relative transition probabilities were deduced from experimental data and compared with neighboring even-even and odd-A nuclei, An anomalously large band crossing frequency was observed in the excited band, and a pronounced signature inversion was observed in the yrast band of Lu-164. These anomalies may be associated with residual neutron-proton interactions. C1 OAK RIDGE NATL LAB,OAK RIDGE,TN 37831. AECL RES,CHALK RIVER LABS,CHALK RIVER,ON K0J 1J0,CANADA. MCMASTER UNIV,HAMILTON,ON L8S 4M1,CANADA. UNIV OTTAWA,OTTAWA,ON K1N 6N5,CANADA. RP Wang, XH (reprint author), UNIV ROCHESTER,NSRL,271 E RIVER RD,ROCHESTER,NY 14627, USA. RI Fitch, Michael/E-5757-2011; Devlin, Matthew/B-5089-2013; radford, David/A-3928-2015 OI Fitch, Michael/0000-0002-2494-9486; Devlin, Matthew/0000-0002-6948-2154; NR 43 TC 13 Z9 13 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 OCT 7 PY 1996 VL 608 IS 1 BP 77 EP 105 DI 10.1016/0375-9474(96)00254-0 PG 29 WC Physics, Nuclear SC Physics GA VM366 UT WOS:A1996VM36600006 ER PT J AU Allen, B Caldwell, RR Shellard, EPS Stebbins, A Veeraraghavan, S AF Allen, B Caldwell, RR Shellard, EPS Stebbins, A Veeraraghavan, S TI Large angular scale anisotropy in cosmic microwave background induced by cosmic strings SO PHYSICAL REVIEW LETTERS LA English DT Article ID COBE; RADIATION AB We simulate the anisotropy in the cosmic microwave background (CMB) induced by cosmic strings. By numerically evolving a network of cosmic strings we generate full-sky CMB temperature anisotropy maps. Based on 192 maps, we compute the anisotropy power spectrum for multipole moments l less than or equal to 20. By comparing with the observed temperature anisotropy, we set the normalization for the cosmic string mass per unit length mu, obtaining G mu/c(2) = 1.05(-0.20)(0.35) x 10(-6), which is consistent with all other observational constraints on Cosmic strings. We demonstrate that the anisotropy pattern is consistent with a Gaussian random field on large angular scales. C1 UNIV CAMBRIDGE,DEPT APPL MATH & THEORET PHYS,CAMBRIDGE CB3 9EW,ENGLAND. NASA,FERMILAB ASTROPHYS CTR,BATAVIA,IL 60510. UNIV MANCHESTER,NUFFIELD RADIO ASTRON LABS,JODRELL BANK,MACCLESFIELD SK11 9DL,CHESHIRE,ENGLAND. RP Allen, B (reprint author), UNIV WISCONSIN,DEPT PHYS,POB 413,MILWAUKEE,WI 53201, USA. RI Allen, Bruce/K-2327-2012; OI Allen, Bruce/0000-0003-4285-6256; Caldwell, Robert/0000-0001-7490-7463 NR 22 TC 53 Z9 53 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 OCT 7 PY 1996 VL 77 IS 15 BP 3061 EP 3065 DI 10.1103/PhysRevLett.77.3061 PG 5 WC Physics, Multidisciplinary SC Physics GA VL096 UT WOS:A1996VL09600001 ER PT J AU Kolb, EW Mohapatra, RN Teplitz, VL AF Kolb, EW Mohapatra, RN Teplitz, VL TI New supernova constraints on sterile-neutrino production SO PHYSICAL REVIEW LETTERS LA English DT Article ID DARK-MATTER; OSCILLATIONS; SN1987A; BURST AB We consider the possibility that a light, sterile-neutrino species nu(S) can be produced by nu(e) scattering during the cooling of a proto-neutron star. If we parametrize the sterile-neutrino production cross section by a parameter A as sigma(nu(e)X --> nu(S)X) = A sigma(nu(e) --> nu(e)X), where X is an electron, neutron, or proton, we show that A Is constrained by limits to the conversion of nu(e) to nu(S) in the region between the sterile-neutrino trapping region and the electron-neutrino, trapping region. This consideration excludes values of A in the range 10(-4) less than or similar to A less than or similar to 10(-1). C1 UNIV CHICAGO,ENRICO FERMI INST,DEPT ASTRON & ASTROPHYS,CHICAGO,IL 60637. UNIV MARYLAND,DEPT PHYS,COLLEGE PK,MD 20742. SO METHODIST UNIV,DEPT PHYS,DALLAS,TX 75275. RP Kolb, EW (reprint author), FERMILAB NATL ACCELERATOR LAB,NASA,FERMILAB ASTROPHYS CTR,BATAVIA,IL 60510, USA. NR 31 TC 14 Z9 14 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 OCT 7 PY 1996 VL 77 IS 15 BP 3066 EP 3069 DI 10.1103/PhysRevLett.77.3066 PG 4 WC Physics, Multidisciplinary SC Physics GA VL096 UT WOS:A1996VL09600002 ER PT J AU Athanassopoulos, C Auerbach, LB Burman, RL Cohen, I Caldwell, DI Dieterle, BD Donahue, JB Eisner, AM Fazely, A Federspiel, FJ Garvey, GT Gray, M Gunasingha, RM Imlay, R Johnston, K Kim, HJ Louis, WC Majkic, R Margulies, J McIlhany, K Metcalf, W Mills, GB Reeder, RA Sandberg, V Smith, D Stancu, I Strossman, W Tayloe, R VanDalen, GJ Vernon, W Wadia, N Waltz, J Wang, YX White, DH Works, D Xiao, Y Yellin, S AF Athanassopoulos, C Auerbach, LB Burman, RL Cohen, I Caldwell, DI Dieterle, BD Donahue, JB Eisner, AM Fazely, A Federspiel, FJ Garvey, GT Gray, M Gunasingha, RM Imlay, R Johnston, K Kim, HJ Louis, WC Majkic, R Margulies, J McIlhany, K Metcalf, W Mills, GB Reeder, RA Sandberg, V Smith, D Stancu, I Strossman, W Tayloe, R VanDalen, GJ Vernon, W Wadia, N Waltz, J Wang, YX White, DH Works, D Xiao, Y Yellin, S TI Evidence for (nu)over-bar(mu)->(nu)over-bar(e) oscillations from the LSND experiment at the Los Alamos meson physics facility SO PHYSICAL REVIEW LETTERS LA English DT Article ID NEUTRINO OSCILLATIONS; SEARCH; PROTONS; BEAM AB A search for <(nu)over bar (mu)> --> <(nu)over bar (e)> oscillations has been conducted at the Los Alamos Meson Physics Facility by using <(nu)over bar (mu)> from mu(+) decay at rest. The <(nu)over bar (e)> are detected via the reaction <(nu)over bar (e)> p --> e(+)n, correlated with a gamma from np --> d gamma (2.2 MeV). The use of tight cuts to identify e(+) events with correlated gamma rays yields 22 events with e(+) energy between 36 and 60 MeV and only 4.6 +/- 0.6 background events. A fit to the e(+) events between 20 and 60 MeV yields a total excess of 51.0(-19.5)(+20.2) +/- 8.0 events. If attributed to <(nu)over bar (mu)> --> <(nu)over bar (e)> oscillations, this corresponds to an oscillation probability of (0.31 +/- 0.12 +/- 0.05)%. C1 UNIV SAN DIEGO,SAN DIEGO,CA 92093. UNIV CALIF SANTA BARBARA,SANTA BARBARA,CA 93106. EMBRY RIDDLE AERONAUT UNIV,PRESCOTT,AZ 86301. LINFIELD COLL,MCMINNVILLE,OR 97128. LOS ALAMOS NATL LAB,LOS ALAMOS,NM 87545. LOUISIANA STATE UNIV,BATON ROUGE,LA 70803. LOUISIANA TECH UNIV,RUSTON,LA 71272. UNIV NEW MEXICO,ALBUQUERQUE,NM 87131. SOUTHERN UNIV,BATON ROUGE,LA 70813. TEMPLE UNIV,PHILADELPHIA,PA 19122. UNIV CALIF,INTERCAMPUS INST RES PARTICLE ACCELERATORS,STANFORD,CA 94309. RP Athanassopoulos, C (reprint author), UNIV CALIF RIVERSIDE,RIVERSIDE,CA 92521, USA. NR 15 TC 704 Z9 705 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 OCT 7 PY 1996 VL 77 IS 15 BP 3082 EP 3085 DI 10.1103/PhysRevLett.77.3082 PG 4 WC Physics, Multidisciplinary SC Physics GA VL096 UT WOS:A1996VL09600006 ER PT J AU Schulz, K Kaindl, G Domke, M Bozek, JD Heimann, PA Schlachter, AS Rost, JM AF Schulz, K Kaindl, G Domke, M Bozek, JD Heimann, PA Schlachter, AS Rost, JM TI Observation of new Rydberg series and resonances in doubly excited helium at ultrahigh resolution SO PHYSICAL REVIEW LETTERS LA English DT Article ID = 2 THRESHOLD; PROPENSITY RULES; STATES; PHOTOIONIZATION; HE AB We report on a striking improvement in spectral resolution in the soft x-ray range to 1.0 meV at 64.1 eV, measured via the mu eV-wide, 2, -l(3) double-excitation resonance of helium. This ultrahigh resolution combined with the high photon flux at undulator beam line 9.0.1 of the Advanced Light Source have allowed observation of new Rydberg series and resonances below the N = 3 threshold of doubly excited He. The obtained resonance parameters (energies, lifetime widths, and Fano-q parameters) are in excellent agreement with the results of state-of-the-art calculations. C1 LAWRENCE BERKELEY LAB,ADV LIGHT SOURCE,BERKELEY,CA 94720. UNIV FREIBURG,FAK PHYS,D-79104 FREIBURG,GERMANY. RP Schulz, K (reprint author), FREE UNIV BERLIN,INST EXPT PHYS,ARNIMALLEE 14,D-14195 BERLIN,GERMANY. RI Bozek, John/E-4689-2010; Bozek, John/E-9260-2010; OI Bozek, John/0000-0001-7486-7238; Rost, Jan M./0000-0002-8306-1743 NR 19 TC 125 Z9 125 U1 0 U2 6 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 0031-9007 J9 PHYS REV LETT JI Phys. Rev. Lett. PD OCT 7 PY 1996 VL 77 IS 15 BP 3086 EP 3089 DI 10.1103/PhysRevLett.77.3086 PG 4 WC Physics, Multidisciplinary SC Physics GA VL096 UT WOS:A1996VL09600007 ER PT J AU Mazzucato, E Batha, SH Beer, M Bell, M Bell, RE Budny, RV Bush, C Hahm, TS Hammett, GW Levinton, FM Nazikian, R Park, H Rewoldt, G Schmidt, GL Synakowski, EJ Tang, WM Taylor, G Zarnstorff, MC AF Mazzucato, E Batha, SH Beer, M Bell, M Bell, RE Budny, RV Bush, C Hahm, TS Hammett, GW Levinton, FM Nazikian, R Park, H Rewoldt, G Schmidt, GL Synakowski, EJ Tang, WM Taylor, G Zarnstorff, MC TI Turbulent fluctuations in TFTR configurations with reversed magnetic shear SO PHYSICAL REVIEW LETTERS LA English DT Article ID DIII-D TOKAMAK; MICROWAVE REFLECTOMETRY; DENSITY-FLUCTUATIONS; POLOIDAL ROTATION; VH-MODE; CONFINEMENT; PLASMAS; BIFURCATION; SUPPRESSION; DISCHARGES AB Turbulent fluctuations in plasmas with reversed magnetic shear have been investigated on the Tokamak Fusion Test Reactor. Under intense auxiliary heating, these plasmas are observed to bifurcate into two states with different transport properties. In the state with better confinement, it has been found that the level of fluctuations is very small throughout most of the region with negative shear. By contrast, the state with lower confinement is characterized by large bursts of fluctuations which suggest a competition between the driving and the suppression of turbulence. These results are consistent with the suppression of turbulence by the E x B velocity shear. C1 FUS PHYS & TECHNOL,TORRANCE,CA 90503. OAK RIDGE NATL LAB,OAK RIDGE,TN 37831. RP Mazzucato, E (reprint author), PRINCETON PLASMA PHYS LAB,POB 451,PRINCETON,NJ 08543, USA. RI Hammett, Gregory/D-1365-2011 OI Hammett, Gregory/0000-0003-1495-6647 NR 26 TC 160 Z9 160 U1 0 U2 6 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 0031-9007 J9 PHYS REV LETT JI Phys. Rev. Lett. PD OCT 7 PY 1996 VL 77 IS 15 BP 3145 EP 3148 DI 10.1103/PhysRevLett.77.3145 PG 4 WC Physics, Multidisciplinary SC Physics GA VL096 UT WOS:A1996VL09600022 ER PT J AU BarAd, S Kner, P Marquezini, MV Chemla, DS ElSayed, K AF BarAd, S Kner, P Marquezini, MV Chemla, DS ElSayed, K TI Carrier dynamics in the quantum kinetic regime SO PHYSICAL REVIEW LETTERS LA English DT Article ID PULSE-EXCITED SEMICONDUCTOR; LO-PHONON SCATTERING; FERMI SEAS; GAAS; RELAXATION; MEMORY; SINGULARITIES; ABSORPTION AB We present a study of carrier dynamics in GaAs during and just after creation by ultrashort laser pulses. We observe a quasi-instantaneous spread of the carrier population in momentum-energy space. Attempts to fit the scattering rates in the relaxation time approximation result in parameters outside the range of validity of the theory. We interpret this as a failure of the Boltzmann kinetic approach in the quantum kinetic regime. C1 LAWRENCE BERKELEY LAB,DIV SCI MAT,BERKELEY,CA 94720. UNIV FLORIDA,DEPT PHYS,GAINESVILLE,FL 32611. RP BarAd, S (reprint author), UNIV CALIF BERKELEY,DEPT PHYS,BERKELEY,CA 94720, USA. NR 21 TC 43 Z9 43 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 OCT 7 PY 1996 VL 77 IS 15 BP 3177 EP 3180 DI 10.1103/PhysRevLett.77.3177 PG 4 WC Physics, Multidisciplinary SC Physics GA VL096 UT WOS:A1996VL09600030 ER PT J AU Aranson, I Vinokur, V AF Aranson, I Vinokur, V TI Surface instabilities and plastic deformation of vortex lattices SO PHYSICAL REVIEW LETTERS LA English DT Article ID FLUX-LINE LATTICE; SUPERCONDUCTORS AB We investigate the stability of the vortex configuration in thin superconducting strips under an applied current analytically and by numerical simulation of the time-dependent Ginzburg-Landau equation. We show that the stationary vortex lattice becomes unstable with respect to long-wavelength perturbations above some critical current I-c. We find that at currents slightly exceeding I-c the vortex phase develops plastic flow, where large coherent pieces of the lattice are separated by lines of defects and slide with respect to each other (ice-floe-like motion). At elevated current a transition to elastic flow is observed. C1 ARGONNE NATL LAB,ARGONNE,IL 60439. RP Aranson, I (reprint author), BAR ILAN UNIV,IL-52900 RAMAT GAN,ISRAEL. RI Aranson, Igor/I-4060-2013 NR 14 TC 11 Z9 11 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 OCT 7 PY 1996 VL 77 IS 15 BP 3208 EP 3211 DI 10.1103/PhysRevLett.77.3208 PG 4 WC Physics, Multidisciplinary SC Physics GA VL096 UT WOS:A1996VL09600038 ER PT J AU Hughes, RJ James, DFV Knill, EH Laflamme, R Petschek, AG AF Hughes, RJ James, DFV Knill, EH Laflamme, R Petschek, AG TI Decoherence bounds on quantum computation with trapped ions SO PHYSICAL REVIEW LETTERS LA English DT Article ID LOGIC GATE; COMPUTERS AB Using simple physical arguments we investigate the capabilities of a quantum computer based on cold trapped ions. From the limitations imposed on such a device by spontaneous decay, laser phase coherence, ion heating, and other sources of error, we derive a bound between the number of laser interactions and the number of ions that may be used. The largest number which may be facto-ed using a variety of species of ion is determined. RP Hughes, RJ (reprint author), LOS ALAMOS NATL LAB,LOS ALAMOS,NM 87545, USA. RI James, Daniel/B-9805-2009 OI James, Daniel/0000-0003-3981-4602 NR 22 TC 63 Z9 64 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 OCT 7 PY 1996 VL 77 IS 15 BP 3240 EP 3243 DI 10.1103/PhysRevLett.77.3240 PG 4 WC Physics, Multidisciplinary SC Physics GA VL096 UT WOS:A1996VL09600046 ER PT J AU Lauffenburger, DA Chu, LL French, A Oehrtman, G Reddy, C Wells, A Niyogi, S Wiley, HS AF Lauffenburger, DA Chu, LL French, A Oehrtman, G Reddy, C Wells, A Niyogi, S Wiley, HS TI Engineering dynamics of growth factors and other therapeutic ligands SO BIOTECHNOLOGY AND BIOENGINEERING LA English DT Article; Proceedings Paper CT Biochemical Engineering IX - Interdisciplinary Foundations for Creating New Biotechnology CY MAY 21-26, 1995 CL DAVOS, SWITZERLAND DE growth factors; receptors; trafficking; mammalian cells; cell engineering; cytokine ligands ID STIMULATES BONE-RESORPTION; FACTOR-ALPHA; FACTOR-RECEPTOR; GENE-THERAPY; TGF-ALPHA; POSTENDOCYTIC TRAFFICKING; SKIN FIBROBLASTS; PC12 CELLS; FACTOR EGF; BINDING AB Peptide growth factors and other receptor-binding cytokine ligands are of interest in contemporary molecular health care approaches in applications such as wound healing, tissue regeneration, and gene therapy. Development of effective technologies based on operation of these regulatory molecules requires an ability to deliver the ligands to target cells in a reliable and well-characterizable manner. Quantitative information concerning the fate of peptide ligands within tissues is necessary for adequate interpretation of experimental observations at the tissue level and for truly rational engineering design of ligand-based therapies. To address this need, we are undertaking efforts to elucidate effects of key molecular and cellular parameters on temporal and spatial distribution of cytokines in cell population and cell/matrix systems. In this article we summarize some of our recent findings on dynamics of growth factor depletion by cellular endocytic trafficking, growth factor transport through cellular matrices, and growth factor production and release by autocrine cell systems. (C) 1996 John Wiley & Sons, Inc. C1 UNIV ILLINOIS,DEPT CHEM ENGN,URBANA,IL 61801. UNIV ALABAMA,DEPT PATHOL,BIRMINGHAM,AL 35294. OAK RIDGE NATL LAB,OAK RIDGE,TN. UNIV UTAH,DEPT PATHOL,SALT LAKE CITY,UT. RP Lauffenburger, DA (reprint author), MIT,DEPT CHEM ENGN,CAMBRIDGE,MA 02139, USA. OI Wiley, Steven/0000-0003-0232-6867; Wells, Alan/0000-0002-1637-8150 NR 79 TC 9 Z9 9 U1 0 U2 4 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 OCT 5 PY 1996 VL 52 IS 1 BP 61 EP 80 DI 10.1002/(SICI)1097-0290(19961005)52:1<61::AID-BIT6>3.0.CO;2-X PG 20 WC Biotechnology & Applied Microbiology SC Biotechnology & Applied Microbiology GA VH413 UT WOS:A1996VH41300007 PM 18629852 ER PT J AU Zakrzewski, VG Ortiz, JV Nichols, JA Heryadi, D Yeager, DL Golab, JT AF Zakrzewski, VG Ortiz, JV Nichols, JA Heryadi, D Yeager, DL Golab, JT TI Comparison of perturbative and multiconfigurational electron propagator methods SO INTERNATIONAL JOURNAL OF QUANTUM CHEMISTRY LA English DT Article ID IONIZATION-POTENTIALS; OPEN-SHELL; AFFINITIES; ATOMS; OH; CN AB Ionization energies below 20 eV of 10 molecules calculated with electron propagator techniques employing Hartree-Fock orbitals and multiconfigurational self-consistent field orbitals are compared. Diagonal and nondiagonal self-energy approximations are used in the perturbative formalism. Three diagonal methods based on second- and third-order self-energy terms, all known as the outer valence Green's function, are discussed. A procedure for selecting the most reliable of these three versions for a given calculation is tested. Results with a polarized, triple zeta basis produce root mean square errors with respect to experiment of approximately 0.3 eV. Use of the selection procedure has a slight influence on the quality of the results. A related, nondiagonal method, known as ADC(3), performs infinite-order summations on several types of self-energy contributions, is complete through third-order, and produces similar accuracy. These results are compared to ionization energies calculated with the multiconfigurational spin-tenser electron propagator method. Complete active space wave functions or close approximations constitute the reference states. Simple field operators and transfer operators pertaining to the active space define the operator manifold. With the same basis sets, these methods produce ionization energies with accuracy that is comparable to that of the perturbative techniques. (C) 1996 John Wiley & Sons, Inc. C1 TEXAS A&M UNIV, DEPT CHEM, COLLEGE STN, TX 77843 USA. UNIV NEW MEXICO, DEPT CHEM, ALBUQUERQUE, NM 87131 USA. PACIFIC NW LAB, RICHLAND, WA 99352 USA. AMOCO CORP, NAPERVILLE, IL 60566 USA. RI Yeager, Danny/D-3679-2015; OI Yeager, Danny/0000-0001-9832-0034; Nichols, Jeffrey/0000-0001-5454-9726 NR 26 TC 149 Z9 149 U1 1 U2 9 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 OCT 5 PY 1996 VL 60 IS 1 BP 29 EP 36 DI 10.1002/(SICI)1097-461X(1996)60:1<29::AID-QUA3>3.0.CO;2-7 PG 8 WC Chemistry, Physical; Mathematics, Interdisciplinary Applications; Physics, Atomic, Molecular & Chemical SC Chemistry; Mathematics; Physics GA VE086 UT WOS:A1996VE08600004 ER PT J AU Geck, RK Larimer, FW Hartman, FC AF Geck, RK Larimer, FW Hartman, FC TI Identification of residues of spinach thioredoxin f that influence interactions with target enzymes SO JOURNAL OF BIOLOGICAL CHEMISTRY LA English DT Article ID ESCHERICHIA-COLI THIOREDOXIN; CHLOROPLAST FRUCTOSE-1,6-BISPHOSPHATASE; FRUCTOSE 1,6-BISPHOSPHATASE; MALATE-DEHYDROGENASE; REDUCTIVE ACTIVATION; C-4 PHOTOSYNTHESIS; CRYSTAL-STRUCTURE; PURIFICATION; RESOLUTION; MECHANISM AB The necessity for two types of thioredoxins (Trx f and m) within chloroplasts of higher plants that mediate the same redox chemistry with various target enzymes is not well understood. To approach this complex issue, we have applied site-directed mutagenesis to the identification of residues of Trx f that affect its binding to and selectivity for target enzymes. Based upon amino acid sequence alignments and the three-dimensional structure of Escherichia coli thioredoxin, putative key residues of Trx f were replaced with residues found at corresponding positions of Trx m to generate the mutants K58E, Q75D, N74D, and deletion mutants Delta Asn-74 and Delta Asn-77. Kinetics of activation of oxidized recombinant sorghum leaf NADP-dependent malate dehydrogenase and oxidized spinach chloroplastic fructose-1,6-bisphosphatase by wild-type Trx f, wild-type Trx m, and Trx f mutants were compared. All of the mutants are less efficient than wild-type Trx f in the activation of fructose-1,6-bisphosphatase and are altered in both S-0.5 and V-max. In contrast to literature reports, the activation of NADP-dependent malate dehydrogenase does not display rate saturation kinetics with respect to the concentration of Trx f, thereby signifying very weak interactions between the two proteins. The mutants of Trx f likewise interact only weakly with NADP-dependent malate dehydrogenase, but the apparent second-order rate constants for activation are increased compared to that with wild-type Trx f. Thus, Lys-58, Asn-74, Gln-75, and Asn-77 of Trx f contribute to its interaction with target enzymes and influence target protein selectivity. C1 OAK RIDGE NATL LAB,DIV BIOL,PROT ENGN PROGRAM,OAK RIDGE,TN 37831. OAK RIDGE NATL LAB,OAK RIDGE GRAD SCH BIOMED SCI,OAK RIDGE,TN 37831. NR 36 TC 39 Z9 39 U1 0 U2 4 PU AMER SOC BIOCHEMISTRY MOLECULAR BIOLOGY INC PI BETHESDA PA 9650 ROCKVILLE PIKE, BETHESDA, MD 20814 SN 0021-9258 J9 J BIOL CHEM JI J. Biol. Chem. PD OCT 4 PY 1996 VL 271 IS 40 BP 24736 EP 24740 PG 5 WC Biochemistry & Molecular Biology SC Biochemistry & Molecular Biology GA VM674 UT WOS:A1996VM67400064 ER PT J AU Wolf, SG Nogales, E Kikkawa, M Gratzinger, D Hirokawa, N Downing, KH AF Wolf, SG Nogales, E Kikkawa, M Gratzinger, D Hirokawa, N Downing, KH TI Interpreting a medium-resolution model of tubulin: Comparison of zinc-sheet and microtubule structure SO JOURNAL OF MOLECULAR BIOLOGY LA English DT Article DE high-resolution electron microscopy; microtubules; tubulin structure; electron crystallography; protein structure ID PROTEIN SECONDARY STRUCTURE; KINESIN MOTOR DOMAIN; TAXOL-BINDING-SITE; X-RAY-DIFFRACTION; BETA-TUBULIN; 3-DIMENSIONAL STRUCTURE; ELECTRON-MICROSCOPY; EXCHANGEABLE GTP; GAMMA-TUBULIN; CHLAMYDOMONAS FLAGELLA AB We previously used electron crystallography of zinc-induced two-dimensional crystalline sheets of tubulin to construct a medium-resolution three dimensional (3-D) reconstruction (at 6.5 Angstrom) of this protein. Here we present an improved model, and extend the interpretation to correlate it to microtubule structure. Secondary sequence predictions and projection density maps of subtilisin-cleaved tubulin provide information on the location of the C-terminal portion, which has been suggested to be involved in the binding of microtubule-associated proteins. The zinc-sheet tubulin model is compared to microtubules in two ways; comparison of electron diffraction from the zinc-sheets to electron diffraction from microtubules, and by docking the zinc-sheet protofilament 3-D model into a helical reconstruction from ice-embedded microtubules. By correlating the zinc-sheet protofilament to a reconstruction of axonemal protofilaments, we assigned polarity to the protofilament in our model. The polarity assignment, together with our model for dimer boundaries and the assignment of alpha- and beta-monomers in our reconstruction, provides a microtubule model where the alpha-monomer crowns the plus- (or fast-growing) end of the microtubule and contact is made in the centrosome with gamma-tubulin via the beta-monomer. (C) 1996 Academic Press Limited C1 UNIV TOKYO,FAC MED,DEPT ANAT & CELL BIOL,BUNKYO KU,TOKYO 113,JAPAN. RP Wolf, SG (reprint author), LAWRENCE BERKELEY LAB,DIV LIFE SCI,BERKELEY,CA 94720, USA. RI Kikkawa, Masahide/A-6692-2010; WOLF, SHARON/K-1768-2012; OI Kikkawa, Masahide/0000-0001-7656-8194; WOLF, SHARON/0000-0002-5337-5063; Gratzinger, Dita/0000-0002-9182-8123 FU NIGMS NIH HHS [GM36884, GM46033] NR 81 TC 21 Z9 21 U1 0 U2 3 PU ACADEMIC PRESS LTD PI LONDON PA 24-28 OVAL RD, LONDON, ENGLAND NW1 7DX SN 0022-2836 J9 J MOL BIOL JI J. Mol. Biol. PD OCT 4 PY 1996 VL 262 IS 4 BP 485 EP 501 DI 10.1006/jmbi.1996.0530 PG 17 WC Biochemistry & Molecular Biology SC Biochemistry & Molecular Biology GA VK749 UT WOS:A1996VK74900009 PM 8893858 ER PT J AU Dodelson, S Gates, EI Turner, MS AF Dodelson, S Gates, EI Turner, MS TI Cold dark matter SO SCIENCE LA English DT Review ID LARGE-SCALE STRUCTURE; BIG-BANG NUCLEOSYNTHESIS; MICROWAVE BACKGROUND ANISOTROPIES; MINIMAL ISOCURVATURE MODEL; DAMPED LYMAN-ALPHA; COSMOLOGICAL CONSTANT; MASS FLUCTUATIONS; CMB ANISOTROPIES; HUBBLE CONSTANT; COBE SATELLITE AB Motivated by inflation, the theory of big-bang nucleosynthesis, and the quest for a deeper understanding of fundamental forces and particles, a paradigm for the development of structure in the universe has evolved. It holds that most of the matter exists in the form of slowly moving elementary particles left over from the earliest moments-cold dark matter-and that the small density inhomogeneities that seed structure formation arose from quantum fluctuations around 10(-34) seconds after the big bang. A flood of observations, from determinations of the Hubble constant to measurements of the anisotropy of cosmic background radiation, are now testing the cold dark matter paradigm. C1 UNIV CHICAGO,ENRICO FERMI INST,DEPT ASTRON & ASTROPHYS,CHICAGO,IL 60637. UNIV CHICAGO,ENRICO FERMI INST,DEPT PHYS,CHICAGO,IL 60637. RP Dodelson, S (reprint author), FERMILAB NATL ACCELERATOR LAB,NASA,FERMILAB ASTROPHYS CTR,BATAVIA,IL 60510, USA. NR 131 TC 56 Z9 56 U1 1 U2 1 PU AMER ASSOC ADVANCEMENT SCIENCE PI WASHINGTON PA 1200 NEW YORK AVE, NW, WASHINGTON, DC 20005 SN 0036-8075 J9 SCIENCE JI Science PD OCT 4 PY 1996 VL 274 IS 5284 BP 69 EP 75 DI 10.1126/science.274.5284.69 PG 7 WC Multidisciplinary Sciences SC Science & Technology - Other Topics GA VK748 UT WOS:A1996VK74800047 ER PT J AU Collart, FR Osipiuk, J Trent, J Olsen, GJ Huberman, E AF Collart, FR Osipiuk, J Trent, J Olsen, GJ Huberman, E TI Cloning, characterization and sequence comparison of the gene coding for IMP dehydrogenase from Pyrococcus furiosus SO GENE LA English DT Article DE gene isolation; DNA sequence; phylogeny; protein homology; Archae ID GLUTAMATE-DEHYDROGENASE; HYPERTHERMOPHILIC ARCHAEON; NUCLEOTIDE-SEQUENCE; MUTATIONAL ANALYSIS; UNIVERSAL TREE; CELLS; EXPRESSION; EVOLUTION; PROMOTER; PROTEIN AB We have cloned and characterized the gene encoding inosine monophosphate dehydrogenase (IMPDH) from Pyrococcus furiosus (PS), a hyperthermophillic archeon. Sequence analysis of the Pf gene indicated an open reading frame specifying a protein of 485 amino acids (aa) with a calculated M(r) of 52900. Canonical Archaea promoter elements, Box A and Box B, are located -49 and -17 nucleotides (nt), respectively, upstream of the putative start codon. The sequence of the putative active-site region conforms to the IMPDH signature motif and contains a putative active-site cysteine. Phylogenetic relationships derived by using all available IMPDH sequences are consistent with trees developed for other molecules; they do not precisely resolve the history of Pf IMPDH but indicate a close similarity to bacterial IMPDH proteins. The phylogenetic analysis indicates that a gene duplication occurred prior to the division between rodents and humans, accounting for the Type I and II isoforms identified in mice and humans. C1 ARGONNE NATL LAB,CTR MECHNIST BIOL & BIOTECHNOL,ARGONNE,IL 60439. UNIV ILLINOIS,DEPT MICROBIOL,URBANA,IL 60439. OI Collart, Frank/0000-0001-6942-4483 NR 38 TC 9 Z9 11 U1 0 U2 0 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0378-1119 J9 GENE JI Gene PD OCT 3 PY 1996 VL 174 IS 2 BP 209 EP 216 DI 10.1016/0378-1119(96)00044-3 PG 8 WC Genetics & Heredity SC Genetics & Heredity GA VM929 UT WOS:A1996VM92900004 PM 8890736 ER PT J AU Collart, FR Osipiuk, J Trent, J Olsen, GJ Huberman, E AF Collart, FR Osipiuk, J Trent, J Olsen, GJ Huberman, E TI Cloning and characterization of the gene encoding IMP dehydrogenase from Arabidopsis thaliana SO GENE LA English DT Article DE gene isolation; DNA sequence; protein homology; plant ID NUCLEOTIDE-SEQUENCE; ESCHERICHIA-COLI-K12; EXPRESSION; CELLS AB We have cloned and characterized the gene encoding inosine monophosphate dehydrogenase (IMPDH) from Arabidopsis thaliana (At). The transcription unit of the At gene spans approximately 1900 bp and specifies a protein of 503 amino acids with a calculated relative molecular mass (M(r)) of 54 190. The gene is comprised of a minimum of four introns and five exons with all donor and acceptor splice sequences conforming to previously proposed consensus sequences. The deduced IMPDH amino-acid sequence from At shows a remarkable similarity to other eukaryotic IMPDH sequences, with a 48% identity to human Type II enzyme. Allowing for conservative substitutions, the enzyme is 69% similar to human Type II IMPDH. The putative active-site sequence of At IMPDH conforms to the IMP dehydrogenase/guanosine monophosphate reductase motif and contains an essential active-site cysteine residue. C1 ARGONNE NATL LAB,CTR MECHANIST BIOL & BIOTECHOL,ARGONNE,IL 60439. UNIV ILLINOIS,DEPT MICROBIOL,URBANA,IL 61801. OI Collart, Frank/0000-0001-6942-4483 NR 19 TC 9 Z9 10 U1 0 U2 2 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0378-1119 J9 GENE JI Gene PD OCT 3 PY 1996 VL 174 IS 2 BP 217 EP 220 DI 10.1016/0378-1119(96)00045-5 PG 4 WC Genetics & Heredity SC Genetics & Heredity GA VM929 UT WOS:A1996VM92900005 PM 8890737 ER PT J AU Ray, D Feller, D More, MB Glendening, ED Armentrout, PB AF Ray, D Feller, D More, MB Glendening, ED Armentrout, PB TI Cation-ether complexes in the gas phase: Bond dissociation energies and equilibrium structures of Li+(1,2-dimethoxyethane)(x), x=1 and 2, and Li+(12-crown-4) SO JOURNAL OF PHYSICAL CHEMISTRY LA English DT Article ID COLLISION-INDUCED DISSOCIATION; MOLECULAR-ORBITAL METHODS; CROWN-ETHERS; BASIS-SETS; BINDING-ENERGIES; AB-INITIO; MACROCYCLIC CHEMISTRY; MASS-SPECTROMETRY; ION COMPLEXATION; LIGAND SOLVATION AB Bond dissociation energies, equilibrium structures, and harmonic vibrational frequencies are reported for Li+(DXE), where DXE = CH3O(CH2)(2)OCH3, Li+(DXE)(2), and Li+(12-crown-4). The bond dissociation energies are determined experimentally by analysis of the thresholds for collision-induced dissociation of the cation-ether complexes by xenon (measured using guided ion beam mass spectrometry) and computationally by ab initio electronic structure calculations. For Li+(DXE)(x); x = 1 and 2, the primary and lowest energy dissociation channel observed experimentally is endothermic loss of one dimethoxyethane molecule. For Li+(12-crown-4), the primary dissociation channel is endothermic loss of the intact crown ether, although ligand fragmentation is also observed. The cross section thresholds are interpreted to yield 0 and 298 K bond energies after accounting for the effects of multiple ion-molecule collisions, internal energy of the complexes, and unimolecular decay rates. The calculated and experimentally-derived bond energies are in good agreement for Li+(DXE), are in reasonable agreement for Li+(12-crown-4), and differ by 32 +/- 12 kJ/mol for Li+(DXE)(2). On average, the experimental bond dissociation energies differ from theory by 9 +/- 6 kJ/mol per metal-oxygen interaction. The equilibrium structures are determined primarily by strong electrostatic and polarization interactions between Li+ and the ligands. Charge transfer interactions are also important, as indicated by a natural energy decomposition analysis. Correlations between the bond dissociation energies and the equilibrium structures demonstrate that the orientation of the C-O-C subunits in the ethers relative to the metal cation is more important than the Li+... O bond length in determining the stability of the complexes as predicted by Hay ct al.(1,2) C1 UNIV UTAH, DEPT CHEM, SALT LAKE CITY, UT 84112 USA. RP Ray, D (reprint author), PACIFIC NW LAB, ENVIRONM MOL SCI LAB, RICHLAND, WA 99352 USA. NR 72 TC 134 Z9 134 U1 0 U2 7 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 SN 0022-3654 J9 J PHYS CHEM-US JI J. Phys. Chem. PD OCT 3 PY 1996 VL 100 IS 40 BP 16116 EP 16125 DI 10.1021/jp961060n PG 10 WC Chemistry, Physical SC Chemistry GA VK731 UT WOS:A1996VK73100013 ER PT J AU Cremer, PS Su, XC Shen, YR Somorjai, GA AF Cremer, PS Su, XC Shen, YR Somorjai, GA TI Hydrogenation and dehydrogenation of propylene on Pt(111) studied by sum frequency generation from UHV to atmospheric pressure SO JOURNAL OF PHYSICAL CHEMISTRY LA English DT Article ID ETHYLENE HYDROGENATION; INFRARED-SPECTRA; SURFACE; ETHYLIDYNE; IODIDE AB The reactions of adsorbed propylene on Pt(lll) in the presence and absence of hydrogen have been studied over 13 orders of magnitude in pressure using infrared-visible sum frequency generation. In the presence of near ambient pressures of hydrogen and propylene at 295 K, propylene hydrogenation was observed to proceed from a physisorbed intermediate (pi-bonded propylene) through a 2-propyl species (Pt-CH(CH3)(2)) to propane, Under UHV conditions in the absence of hydrogen, di-sigma-bonded propylene was found to dehydrogenate to propylidyne just below room temperature and then to vinylmethylidyne (M=CCHCH2) at 450 K on the May to graphite formation. C1 UNIV CALIF BERKELEY,DEPT PHYS,BERKELEY,CA 94720. UNIV CALIF BERKELEY,DEPT CHEM,BERKELEY,CA 94720. UNIV CALIF BERKELEY,LAWRENCE BERKELEY LAB,DIV MAT SCI,BERKELEY,CA 94720. NR 24 TC 89 Z9 89 U1 1 U2 22 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 SN 0022-3654 J9 J PHYS CHEM-US JI J. Phys. Chem. PD OCT 3 PY 1996 VL 100 IS 40 BP 16302 EP 16309 DI 10.1021/jp9613394 PG 8 WC Chemistry, Physical SC Chemistry GA VK731 UT WOS:A1996VK73100042 ER PT J AU CherbonnelLasserre, C Gauny, S Kronenberg, A AF CherbonnelLasserre, C Gauny, S Kronenberg, A TI Suppression of apoptosis by Bcl-2 or Bcl-x(L) promotes susceptibility to mutagenesis SO ONCOGENE LA English DT Article DE Bcl-2; Bcl-x(L); apoptosis; mutagenesis; ionizing radiation ID PROGRAMMED CELL-DEATH; DIPLOID HUMAN-LYMPHOBLASTS; DNA FRAGMENTATION; INDUCED MUTATION; HPRT LOCUS; P53 STATUS; BAX GENE; B-CELLS; IN-VIVO; PROTEIN AB Bcl-2 appears to contribute to neoplasia primarily by promoting cell survival, rather than by stimulating cellular proliferation. Bcl-2, and the related protein Bcl-x(L) each suppress apoptosis induced by a wide variety of stimuli in many different cell types. Here we report that suppression of apoptosis by Bcl-2 or Bcl-x(L) markedly elevates the levels of radiation-induced mutations. This enhanced mutagenesis is the result of an increase in mutation frequency (mutations per survivor) together with a moderate increase in viability. Ectopic expression of either Bcl-2 or Bcl-x(L) enhances radiation mutagenesis in cells with wtp53. Surprisingly, we found that ectopic expression of Bcl-x(L) also promotes mutagenesis in p53(-) cells. These results support the hypothesis that apoptosis plays a crucial role in maintaining genomic integrity by selectively eliminating highly mutated cells from the population. C1 UNIV CALIF BERKELEY,LAWRENCE BERKELEY LAB,DIV LIFE SCI,BERKELEY,CA 94720. FU NCI NIH HHS [R01 CA-62364] NR 46 TC 79 Z9 80 U1 0 U2 1 PU STOCKTON PRESS PI BASINGSTOKE PA HOUNDMILLS, BASINGSTOKE, HAMPSHIRE, ENGLAND RG21 6XS SN 0950-9232 J9 ONCOGENE JI Oncogene PD OCT 3 PY 1996 VL 13 IS 7 BP 1489 EP 1497 PG 9 WC Biochemistry & Molecular Biology; Oncology; Cell Biology; Genetics & Heredity SC Biochemistry & Molecular Biology; Oncology; Cell Biology; Genetics & Heredity GA VL384 UT WOS:A1996VL38400014 PM 8875987 ER PT J AU Bartels, J Ewerz, C Lotter, H Wusthoff, M AF Bartels, J Ewerz, C Lotter, H Wusthoff, M TI Azimuthal distribution of quark-antiquark jets in DIS diffractive dissociation SO PHYSICS LETTERS B LA English DT Article AB We investigate the azimuthal distribution of quark-antiquark jets in DIS diffractive dissociation with large transverse momentum. In this kinematical region the matrix element is expressed in terms of the gluon structure function. For the transverse part of the cross section we find a cos(2 phi)-distribution with the maximum at phi = +/-pi/2, i.e. the jets prefer a direction perpendicular to the electron plane. This is in contrast to boson gluon fusion where the jet cross section for transversely polarized bosons peaks at phi = 0 and phi = pi. We discuss the origin of this striking difference and present numerical results relevant for the diffractive dissociation at HERA. C1 ARGONNE NATL LAB,DIV HIGH ENERGY PHYS,ARGONNE,IL 60439. RP Bartels, J (reprint author), UNIV HAMBURG,INST THEORET PHYS 2,LURUPER CHAUSSEE 149,D-2000 HAMBURG,GERMANY. NR 14 TC 36 Z9 36 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 OCT 3 PY 1996 VL 386 IS 1-4 BP 389 EP 396 DI 10.1016/0370-2693(96)81071-9 PG 8 WC Astronomy & Astrophysics; Physics, Nuclear; Physics, Particles & Fields SC Astronomy & Astrophysics; Physics GA VL896 UT WOS:A1996VL89600057 ER PT J AU Enomoto, R Tanabashi, M AF Enomoto, R Tanabashi, M TI Direct CP violation in B meson decays via rho-omega interference SO PHYSICS LETTERS B LA English DT Article ID ANOMALOUS DIMENSION MATRIX; WEAK NONLEPTONIC DECAYS; ASYMMETRIES AB We investigate B-+/-,B-0 --> rho(0)(omega) h(+/-,0), where rho(0)(omega) decays to pi(+)pi(-) and h is any hadronic final state, such as pi or K. We find large direct CP asymmetry in B meson decays via rho-omega interference. A possible method to determine weak phases, such as phi(2) = arg((VudVub*)/(VtdVtb*)) and phi(3) = arg((VusVub*)/(VtsVtb*)), is also discussed. We show the feasibility to detect the CP asymmetries in these channels by assuming an asymmetric e(+)e(-) collider experiment. 10(9) events are required for the detection of this effect. C1 FERMILAB NATL ACCELERATOR LAB,BATAVIA,IL 60510. RP Enomoto, R (reprint author), NATL LAB HIGH ENERGY PHYS,1-1 OHO,TSUKUBA,IBARAKI 305,JAPAN. NR 27 TC 34 Z9 34 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 OCT 3 PY 1996 VL 386 IS 1-4 BP 413 EP 421 DI 10.1016/0370-2693(96)00979-3 PG 9 WC Astronomy & Astrophysics; Physics, Nuclear; Physics, Particles & Fields SC Astronomy & Astrophysics; Physics GA VL896 UT WOS:A1996VL89600060 ER PT J AU Abe, K Abe, K Abt, I Akagi, T Allen, NJ Ash, WW Aston, D Baird, KG Baltay, C Band, HR Barakat, MB Baranko, G Bardon, O Barklow, T Bazarko, AO BenDavid, R Benvenuti, AC Bilei, GM Bisello, D Blaylock, G Bogart, JR Bolen, B Bolton, T Bower, GR Brau, JE Breidenbach, M Bugg, WM Burke, D Burnett, TH Burrows, PN Busza, W Calcaterra, A Caldwell, DO Calloway, D Camanzi, B Carpinelli, M Cassell, R Castaldi, R Castro, A CavalliSforza, M Chou, A Church, E Cohn, HO Coller, JA Cook, V Cotton, R Cowan, RF Coyne, DG Crawford, G DOliveira, A Damerell, CJS Daoudi, M DeSangro, R DellOrso, R Dervan, PJ Dima, M Dong, DN Du, PYC Dubois, R Eisenstein, BI Elia, R Etzion, E Falciai, D Fan, C Fero, MJ Frey, R Furuno, K Gillman, T Gladding, G Gonzalez, S Hallewell, GD Hart, EL Harton, JL Hasan, A Hasegawa, Y Hasuko, K Hedges, SJ Hertzbach, SS Hildreth, MD Huber, J Huffer, ME Hughes, EW Hwang, H Iwasaki, Y Jackson, DJ Jacques, P Jaros, JA Johnson, AS Johnson, JR Johnson, RA Junk, T Kajikawa, R Kalelkar, M Kang, HJ Karliner, I Kawahara, H Kendall, HW Kim, YD King, ME King, R Kofler, RR Krishna, NM Kroeger, RS Labs, JF Langston, M Lath, A Lauber, JA Leith, DWGS Lia, V Liu, MX Liu, X Loreti, M Lu, A Lynch, HL Ma, J Mancinelli, G Manly, S Mantovani, G Markiewicz, TW Maruyama, T Masuda, H Mazzucato, E McKemey, AK Meadows, BT Messner, R Mockett, PM Moffeit, KC Moore, TB Muller, D Nagamine, T Narita, S Nauenberg, U Neal, H Nussbaum, M Ohnishi, Y Osborne, LS Panvini, RS Park, 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 Rensing, PE Rochester, LS Rowson, PC Russell, JJ Saxton, OH Schalk, T Schindler, RH Schumm, BA Sen, S Serbo, VV Shaevitz, MH Shank, JT Shapiro, G Sherden, DJ Shmakov, KD Simopoulos, C Sinev, NB Smith, SR Smy, MB Snyder, JA Stamer, P Steiner, H Steiner, R Strauss, MG Su, D Suekane, F Sugiyama, A Suzuki, S Swartz, M Szumilo, A Takahashi, T Taylor, FE Torrence, E Trandafir, AI Turk, JD Usher, T Vavra, J Vannini, C Vella, E Venuti, JP Verdier, R Verdini, PG Wagner, SR Waite, AP Watts, SJ Weidemann, AW Weiss, ER Whitaker, JS White, SL Wickens, FJ Williams, DA Williams, DC Williams, SH Willocq, S Wilson, RJ Wisniewski, WJ Woods, M Word, GB Wyss, J Yamamoto, RK Yamartino, JM Yang, X Yellin, SJ Young, CC Yuta, H Zapalac, G Zdarko, RW Zeitlin, C Zhou, J AF Abe, K Abe, K Abt, I Akagi, T Allen, NJ Ash, WW Aston, D Baird, KG Baltay, C Band, HR Barakat, MB Baranko, G Bardon, O Barklow, T Bazarko, AO BenDavid, R Benvenuti, AC Bilei, GM Bisello, D Blaylock, G Bogart, JR Bolen, B Bolton, T Bower, GR Brau, JE Breidenbach, M Bugg, WM Burke, D Burnett, TH Burrows, PN Busza, W Calcaterra, A Caldwell, DO Calloway, D Camanzi, B Carpinelli, M Cassell, R Castaldi, R Castro, A CavalliSforza, M Chou, A Church, E Cohn, HO Coller, JA Cook, V Cotton, R Cowan, RF Coyne, DG Crawford, G DOliveira, A Damerell, CJS Daoudi, M DeSangro, R DellOrso, R Dervan, PJ Dima, M Dong, DN Du, PYC Dubois, R Eisenstein, BI Elia, R Etzion, E Falciai, D Fan, C Fero, MJ Frey, R Furuno, K Gillman, T Gladding, G Gonzalez, S Hallewell, GD Hart, EL Harton, JL Hasan, A Hasegawa, Y Hasuko, K Hedges, SJ Hertzbach, SS Hildreth, MD Huber, J Huffer, ME Hughes, EW Hwang, H Iwasaki, Y Jackson, DJ Jacques, P Jaros, JA Johnson, AS Johnson, JR Johnson, RA Junk, T Kajikawa, R Kalelkar, M Kang, HJ Karliner, I Kawahara, H Kendall, HW Kim, YD King, ME King, R Kofler, RR Krishna, NM Kroeger, RS Labs, JF Langston, M Lath, A Lauber, JA Leith, DWGS Lia, V Liu, MX Liu, X Loreti, M Lu, A Lynch, HL Ma, J Mancinelli, G Manly, S Mantovani, G Markiewicz, TW Maruyama, T Masuda, H Mazzucato, E McKemey, AK Meadows, BT Messner, R Mockett, PM Moffeit, KC Moore, TB Muller, D Nagamine, T Narita, S Nauenberg, U Neal, H Nussbaum, M Ohnishi, Y Osborne, LS Panvini, RS Park, 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 Rensing, PE Rochester, LS Rowson, PC Russell, JJ Saxton, OH Schalk, T Schindler, RH Schumm, BA Sen, S Serbo, VV Shaevitz, MH Shank, JT Shapiro, G Sherden, DJ Shmakov, KD Simopoulos, C Sinev, NB Smith, SR Smy, MB Snyder, JA Stamer, P Steiner, H Steiner, R Strauss, MG Su, D Suekane, F Sugiyama, A Suzuki, S Swartz, M Szumilo, A Takahashi, T Taylor, FE Torrence, E Trandafir, AI Turk, JD Usher, T Vavra, J Vannini, C Vella, E Venuti, JP Verdier, R Verdini, PG Wagner, SR Waite, AP Watts, SJ Weidemann, AW Weiss, ER Whitaker, JS White, SL Wickens, FJ Williams, DA Williams, DC Williams, SH Willocq, S Wilson, RJ Wisniewski, WJ Woods, M Word, GB Wyss, J Yamamoto, RK Yamartino, JM Yang, X Yellin, SJ Young, CC Yuta, H Zapalac, G Zdarko, RW Zeitlin, C Zhou, J TI Measurement of the charged multiplicities in b, c and light quark events from Z(O) decays SO PHYSICS LETTERS B LA English DT Article ID FORWARD-BACKWARD ASYMMETRY; E+E ANNIHILATION; CHARMED MESONS; JETS; HADRONS AB Average charged multiplicities have been measured separately in b, c and light quark (u, d, s) events from Z(0) decays measured in the SLD experiment. Impact parameters of charged tracks were used to select enriched samples of b and light quark events, and reconstructed charmed mesons were used to select c quark events. We measured the charged multiplicities: <(n)over bar (uds)> = 20.21 +/- 0.10(stat.) +/- 0.22(syst.), <(n)over bar (c)> = 21.28 +/- 0.46(stat.)(-0.36)(+0.41)(syst.) and <(n)over bar (b)> = 23.14 +/- 0.10(stat.)(-0.37)(+0.38)(syst.), from which we derived the differences between the total average charged multiplicities of c or b quark events and light quark events: = 1.07 +/- 0.47(stat.)(-0.30)(+0.36)(syst.) and = 2.93 +/- 0.14(stat.)(-0.29)(+0.30)(syst.). We compared these measurements with those at lower center-of-mass energies and with perturbative QCD predictions. These combined results are in agreement with the QCD expectations and disfavor the hypothesis of flavor-independent fragmentation. C1 ADELPHI UNIV, GARDEN CITY, NY 11530 USA. IST NAZL FIS NUCL, I-40126 BOLOGNA, ITALY. BOSTON UNIV, BOSTON, MA 02215 USA. BRUNEL UNIV, UXBRIDGE UB8 3PH, MIDDX, ENGLAND. UNIV CALIF SANTA BARBARA, SANTA BARBARA, CA 93106 USA. UNIV CALIF SANTA CRUZ, SANTA CRUZ, CA 95064 USA. UNIV CINCINNATI, CINCINNATI, OH 45221 USA. COLORADO STATE UNIV, FT COLLINS, CO 80523 USA. UNIV COLORADO, BOULDER, CO 80309 USA. COLUMBIA UNIV, NEW YORK, NY 10027 USA. IST NAZL FIS NUCL, I-44100 FERRARA, ITALY. UNIV FERRARA, 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. 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. STANFORD UNIV, STANFORD LINEAR ACCELERATOR CTR, STANFORD, CA 94309 USA. UNIV TENNESSEE, KNOXVILLE, TN 37996 USA. TOHOKU UNIV, SENDAI, MIYAGI 980, JAPAN. VANDERBILT UNIV, NASHVILLE, TN 37235 USA. UNIV WASHINGTON, SEATTLE, WA 98195 USA. UNIV WISCONSIN, MADISON, WI 53706 USA. YALE UNIV, NEW HAVEN, CT 06511 USA. UNIV GENOA, I-16126 GENOA, ITALY. UNIV PERUGIA, I-06100 PERUGIA, ITALY. RP Abe, K (reprint author), NAGOYA UNIV, CHIKUSA KU, NAGOYA, AICHI 464, JAPAN. RI de Sangro, Riccardo/J-2901-2012; Cavalli-Sforza, Matteo/H-7102-2015; Frey, Raymond/E-2830-2016; Calcaterra, Alessandro/P-5260-2015 OI de Sangro, Riccardo/0000-0002-3808-5455; Frey, Raymond/0000-0003-0341-2636; Calcaterra, Alessandro/0000-0003-2670-4826 NR 37 TC 27 Z9 27 U1 0 U2 2 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0370-2693 J9 PHYS LETT B JI Phys. Lett. B PD OCT 3 PY 1996 VL 386 IS 1-4 BP 475 EP 485 DI 10.1016/0370-2693(96)01025-8 PG 11 WC Astronomy & Astrophysics; Physics, Nuclear; Physics, Particles & Fields SC Astronomy & Astrophysics; Physics GA VL896 UT WOS:A1996VL89600068 ER PT J AU Zheng, YJ Ornstein, RL AF Zheng, YJ Ornstein, RL TI A theoretical study of the structures of flavin in different oxidation and protonation states SO JOURNAL OF THE AMERICAN CHEMICAL SOCIETY LA English DT Article ID TOTALLY OPTIMIZED GEOMETRIES; NUCLEAR MAGNETIC-RESONANCE; REDUCED FLAVIN; CHEMISTRY; RESOLUTION; FLAVODOXIN; COENZYMES; REDUCTASE; C-13; MO AB Ab initio molecular orbital theory was used to investigate the structure of flavin in different oxidation and protonation states using lumiflavin as a model compound. According to our study, oxidized flavin is planar no matter what its protonation state or whether it participates in hydrogen bonding. The structures of flavin semiquinone radicals are planar or very close to planar, but the reduced flavin H(3)Fl(red) (9) is bent with a ring puckering angle of 27.3 degrees along the N5 and N10 axis. The calculations indicate that N1 is the site of protonation for oxidized flavin, which is in agreement with several crystallographic studies. The calculated spin density distribution for flavin semiquinone radicals is also consistent with experimental results. Electrostatic potential derived charges at the RHF/6-31G* level of theory are also provided for both oxidized and reduced flavins. C1 PACIFIC NW LAB, ENVIRONM MOL SCI LAB, RICHLAND, WA 99352 USA. NR 57 TC 105 Z9 105 U1 0 U2 12 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 SN 0002-7863 J9 J AM CHEM SOC JI J. Am. Chem. Soc. PD OCT 2 PY 1996 VL 118 IS 39 BP 9402 EP 9408 DI 10.1021/ja9608151 PG 7 WC Chemistry, Multidisciplinary SC Chemistry GA VK780 UT WOS:A1996VK78000026 ER PT J AU Trifunac, AD Werst, DW Herges, R Neumann, H Prinzbach, H Etzkorn, M AF Trifunac, AD Werst, DW Herges, R Neumann, H Prinzbach, H Etzkorn, M TI (Iso)pagodane radical cations in liquid hydrocarbons: ''Time-resolved fluorescence-detected magnetic resonance'' study of valence isomeric radical cations SO JOURNAL OF THE AMERICAN CHEMICAL SOCIETY LA English DT Article ID TETRAMETHYLENE DICATIONS; NORBORNADIENE; QUADRICYCLANE; CAGE; DELOCALIZATION; PAGODANES; OXIDATION; ELECTRON; ROUTE; PHASE C1 TECH UNIV CAROLO WILHELMINA BRAUNSCHWEIG,INST ORGAN CHEM,D-38106 BRAUNSCHWEIG,GERMANY. UNIV FREIBURG,INST ORGAN CHEM & BIOCHEM,D-79104 FREIBURG,GERMANY. RP Trifunac, AD (reprint author), ARGONNE NATL LAB,DIV CHEM,9700 S CASS AVE,ARGONNE,IL 60439, USA. NR 29 TC 27 Z9 27 U1 0 U2 5 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 SN 0002-7863 J9 J AM CHEM SOC JI J. Am. Chem. Soc. PD OCT 2 PY 1996 VL 118 IS 39 BP 9444 EP 9445 DI 10.1021/ja961035v PG 2 WC Chemistry, Multidisciplinary SC Chemistry GA VK780 UT WOS:A1996VK78000040 ER PT J AU Cook, GK Andrews, MA AF Cook, GK Andrews, MA TI Toward nonoxidative routes to oxygenated organics: Stereospecific deoxydehydration of diols and polyols to alkenes and allylic alcohols catalyzed by the metal oxo complex (C(5)Me(5))ReO3 SO JOURNAL OF THE AMERICAN CHEMICAL SOCIETY LA English DT Article ID MAIN-GROUP ELEMENTS; TRANSITION-METALS; MULTIPLE BONDS; RHENIUM(V); EXTRUSION; HALIDES C1 BROOKHAVEN NATL LAB,DEPT CHEM,UPTON,NY 11973. NR 20 TC 74 Z9 74 U1 1 U2 29 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 SN 0002-7863 J9 J AM CHEM SOC JI J. Am. Chem. Soc. PD OCT 2 PY 1996 VL 118 IS 39 BP 9448 EP 9449 DI 10.1021/ja9620604 PG 2 WC Chemistry, Multidisciplinary SC Chemistry GA VK780 UT WOS:A1996VK78000042 ER PT J AU Rye, RR Yost, FG Mann, JA AF Rye, RR Yost, FG Mann, JA TI Wetting kinetics in surface capillary grooves SO LANGMUIR LA English DT Letter ID DYNAMICS; DROP AB For V-shaped surface grooves in copper, we have obtained the capillary driven flow kinetics for two liquids: unreactive 1-heptanol and eutectic Sn/Pb solder, which is known to react with copper. We show experimentally that the flow of both liquids in these grooves follows the classical Washburn kinetics, i.e., a Poiseuille flow process, modified to include a dynamic contact angle. Because no subsidiary processes are necessary to fit our data, we propose that in this geometry capillary driven solder flow is too rapid for reaction to provide an appreciable effect. Thus, to observe the effects of Sn/Cu reaction kinetics, the flow rate must be decreased, which the present experiments allow through redesign of the groove geometry and size. C1 CASE WESTERN RESERVE UNIV,CLEVELAND,OH 44106. RP Rye, RR (reprint author), SANDIA NATL LABS,CLEVELAND,OH 44106, USA. NR 16 TC 33 Z9 33 U1 1 U2 5 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 SN 0743-7463 J9 LANGMUIR JI Langmuir PD OCT 2 PY 1996 VL 12 IS 20 BP 4625 EP 4627 DI 10.1021/la9605201 PG 3 WC Chemistry, Multidisciplinary; Chemistry, Physical; Materials Science, Multidisciplinary SC Chemistry; Materials Science GA VL059 UT WOS:A1996VL05900005 ER PT J AU Prudhomme, RK Wu, GW Schneider, DK AF Prudhomme, RK Wu, GW Schneider, DK TI Structure and rheology studies of poly(oxyethylene-oxypropylene-oxyethylene) aqueous solution SO LANGMUIR LA English DT Article ID OXIDE) TRIBLOCK-COPOLYMER; COPOLY(OXYETHYLENE OXYPROPYLENE OXYETHYLENE); OSCILLATORY SHEAR MEASUREMENTS; BLOCK-COPOLYMER; PHASE-BEHAVIOR; LIGHT-SCATTERING; MICELLAR STRUCTURES; POLYMERIC MICELLES; GEL FORMATION; O-XYLENE AB Small-angle neutron scattering (SANS) and rheometry were used to investigate the supramolecular structure formed by a poly(oxyethylene-oxypropylene-oxyethylene) (PEO(100)PPO(65)PEO(100), Plutonic F127) copolymer in aqueous solution over a temperature range of 10-75 degrees C and a concentration range of 10-20 wt %. At copolymer concentrations of less than 12.5% the solutions are Newtonian fluids. Gels with an ordered structure (cubic packing of spherical micelles) are observed over a well-defined temperature window when the copolymer concentrations are greater than 17 wt %. The SANS results show that the aggregation number of the micelles is independent of temperature and concentration. Low-yield stresses, very high zero shear viscosities (similar to 10(6) P), and shear thinning are the major rheological characteristics of the gels. Near, but outside, the gel phase boundary the solutions are non-Newtonian (shear thinning). However, SANS shows these solutions contain domains having the same structure as that in the gel phase. The temperature window for ordered structures and non-Newtonian behavior becomes wider with increasing copolymer concentration. The degree of overlap of the micellar shells increases with increasing copolymer concentration at a given temperature and reaches a maximum at similar to 40 degrees C at a fixed polymer concentration. The yield stress is due to repulsive interactions of PEO chains in the overlapped micellar shell. On the basis of SANS and rheology results, the proposed mechanism of gelation is that it involves repulsive interactions among close-packed spherical micelles, rather than aggregation or transitions in micelle morphology to rods or lamellae. C1 BROOKHAVEN NATL LAB,DEPT BIOL,UPTON,NY 11973. RP Prudhomme, RK (reprint author), PRINCETON UNIV,DEPT CHEM ENGN,PRINCETON,NJ 08544, USA. NR 52 TC 179 Z9 184 U1 5 U2 47 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 SN 0743-7463 J9 LANGMUIR JI Langmuir PD OCT 2 PY 1996 VL 12 IS 20 BP 4651 EP 4659 DI 10.1021/la951506b PG 9 WC Chemistry, Multidisciplinary; Chemistry, Physical; Materials Science, Multidisciplinary SC Chemistry; Materials Science GA VL059 UT WOS:A1996VL05900009 ER PT J AU Li, CX Waters, RS McCandlish, CA Johnson, EF AF Li, CX Waters, RS McCandlish, CA Johnson, EF TI Electrical stimulation of a forepaw digit increases the physiological representation of that digit in layer IV of SI cortex in rat SO NEUROREPORT LA English DT Article DE forepaw barrel subfield; FBS; primary somatosensory cortex; SI; rodent barrel cortex; cortical reorganization; receptive field; physiological maps ID LONG-LASTING POTENTIATION; SOMATOSENSORY CORTEX; SYNAPTIC TRANSMISSION; BARREL SUBFIELD; NEONATAL RATS; ORGANIZATION; NEOCORTEX; FIELD AB WE studied the physiological representation of digit three (D3) in rat somatosensory cortex (SI) before and immediately after electrical stimulation (1.5x threshold for 2 h) of the glabrous tip of D3 in anesthetized animals (n = 6). Measurements of D3 representation were also made in anesthetized non-stimulated control animals (n = 2). The post-stimulation areal measurements of D3 representation in experimental animals were statistically significantly larger than both pre-stimulation measurements in experimental animals and post-stimulation measurements in control animals. Our results suggest that short-term electrical stimulation is sufficient to expand the D3 representation in each of the experimental animals, while the maps in non-stimulated controls showed little variation. The fact that these studies were carried out in anesthetized animals suggests that the results are independent of the state of the animal. The present findings emphasize the importance of afferent input in modulating cortical organization. C1 UNIV TENNESSEE,DEPT NEUROBIOL & ANAT,MEMPHIS,TN 38163. OAK RIDGE NATL LAB,OAK RIDGE,TN 37830. NR 18 TC 5 Z9 5 U1 0 U2 0 PU RAPID SCIENCE PUBLISHERS PI LONDON PA 2-6 BOUNDARY ROW, LONDON, ENGLAND SE1 8NH SN 0959-4965 J9 NEUROREPORT JI Neuroreport PD OCT 2 PY 1996 VL 7 IS 14 BP 2395 EP 2400 DI 10.1097/00001756-199610020-00023 PG 6 WC Neurosciences SC Neurosciences & Neurology GA WD442 UT WOS:A1996WD44200024 PM 8951859 ER PT J AU Bardeau, JF Bulou, A Klooster, WT Koetzle, TF Johnson, S Scott, B Swanson, BI Eckert, J AF Bardeau, JF Bulou, A Klooster, WT Koetzle, TF Johnson, S Scott, B Swanson, BI Eckert, J TI Neutron diffraction study of [Pt(en)(2)][Pt(en)(2)I-2](ClO4)(4) at 20 K: Structure and evidence of a new phase transition SO ACTA CRYSTALLOGRAPHICA SECTION B-STRUCTURAL SCIENCE LA English DT Article ID LINEAR-CHAIN COMPLEXES; X = CL; VALENCE; TEMPERATURE; PLATINUM; ELECTRON; CRYSTAL; BR AB The structure at 20K of fully deuterated [Pt(en)(2)]-[Pt(en)(2)I-2](ClO4)(4), where en=ethylenediamine, has been determined by neutron diffraction on a single crystal. It is shown that the symmetry is monoclinic with cell parameters a = 16.650(7), b = 5.760(2), c = 14.751(2) Angstrom and beta = 99.19(1)degrees, that is, with respect to the previously reported room-temperature structures, a doubling of the c parameter is observed. The space group is C2/c and the refinements lead to an R value of 0.0374. All the bond lengths (C-C, C-N, C-D, N-D and Cl-O) and angles are consistent with the expected values and the main difference with respect to the previously reported room-temperature structures results in an ordering of the stacking of the ethylenediamines. The iodines are distributed over two sites, which gives two Pt-I distances, 2.712(3) Angstrom, attributed to the Pt-IV-I bond, and 3.048(3) Angstrom, attributed to Pt-II-I. Actually, very weak diffraction peaks that provide evidence for an additional doubling of the a and b parameters are also observed and a space group C2 is therefore proposed. This could result from a very slight ordering of the chains with respect to one another, but, due to the weakness of such signals and the large number of atoms to be considered, no reliable refinement has been obtained in C2. On the other hand, on heating the crystal the diffraction peaks with I odd greatly decrease in intensity between 150 and 160K, which unambiguously argues for the existence of a phase transition presumably connected to an order-disorder of the ethylenediamines. C1 BROOKHAVEN NATL LAB,DEPT CHEM,UPTON,NY 11973. LOS ALAMOS NATL LAB,SPECT & BIOCHEM GRP,LOS ALAMOS,NM 87545. RP Bardeau, JF (reprint author), UNIV MAINE,LAB PHYS ETAT CONDENSE,CNRS,URA 807,F-72017 LE MANS,FRANCE. RI Scott, Brian/D-8995-2017 OI Scott, Brian/0000-0003-0468-5396 NR 28 TC 9 Z9 9 U1 0 U2 3 PU MUNKSGAARD INT PUBL LTD PI COPENHAGEN PA 35 NORRE SOGADE, PO BOX 2148, DK-1016 COPENHAGEN, DENMARK SN 0108-7681 J9 ACTA CRYSTALLOGR B JI Acta Crystallogr. Sect. B-Struct. Commun. PD OCT 1 PY 1996 VL 52 BP 854 EP 864 DI 10.1107/S0108768196004661 PN 5 PG 11 WC Chemistry, Multidisciplinary; Crystallography SC Chemistry; Crystallography GA VP719 UT WOS:A1996VP71900012 ER PT J AU Jasinski, J LilientalWeber, Z AF Jasinski, J LilientalWeber, Z TI Recrystallization of amorphous layer in ion implanted GaAs - Transmission electron microscopy studies SO ACTA PHYSICA POLONICA A LA English DT Article; Proceedings Paper CT XXV International School on Physics of Semiconducting Compounds CY MAY 27-31, 1996 CL JASZOWIEC, POLAND SP Polish Acad Sci, Inst Phys, Warsaw Univ, Fac Phys, Polish Acad Sci, High Pressure Res Ctr ID TEMPERATURE AB 2 MeV arsenic or gallium ions were used to produce nonstoichiometric buried amorphous layers in gallium arsenide. The mechanism of thermally induced regrowth of these layers was investigated using transmission electron microscopy. Low-temperature annealing resulted in nucleation of high densities of stacking faults. This was associated with the local nonstoichiometry of the amorphous layers. After annealing at high temperatures, in arsenic as well as in gallium implanted samples, two layers of voids, formed in result of vacancies clustering, were found in areas adjacent to the initial location of the amorphous-crystalline interfaces. A qualitative model of the formation of such layers was proposed. C1 UNIV CALIF BERKELEY, LAWRENCE BERKELEY LAB, BERKELEY, CA 94720 USA. RP Jasinski, J (reprint author), UNIV WARSAW, INST EXPT PHYS, HOZA 69, PL-00681 WARSAW, POLAND. RI Liliental-Weber, Zuzanna/H-8006-2012 NR 6 TC 1 Z9 1 U1 0 U2 0 PU POLISH ACAD SCIENCES INST PHYSICS PI WARSAW PA AL LOTNIKOW 32-46, 02-668 WARSAW, POLAND SN 0587-4246 J9 ACTA PHYS POL A JI Acta Phys. Pol. A PD OCT PY 1996 VL 90 IS 4 BP 825 EP 828 PG 4 WC Physics, Multidisciplinary SC Physics GA VV969 UT WOS:A1996VV96900039 ER PT J AU Zimmerman, RW Hadgu, T Bodvarsson, GS AF Zimmerman, RW Hadgu, T Bodvarsson, GS TI A new lumped-parameter model for flow in unsaturated dual-porosity media SO ADVANCES IN WATER RESOURCES LA English DT Article DE unsaturated flow; dual-porosity models; Warren-Root; fractured rocks ID FRACTURED POROUS-MEDIA; HYDRAULIC CONDUCTIVITY; FLUID-FLOW; WATER; PERMEABILITY; SOILS; INFILTRATION; TERM AB A new lumped-parameter approach to simulating unsaturated flow processes in dual-porosity media such as fractured rocks or aggregated soils is presented. Fluid flow between the fracture network and the matrix blocks is described by a non-linear equation that relates the imbibition rate to the local difference in liquid-phase pressure between the fractures and the matrix blocks. Unlike a Warren-Root-type equation, this equation is accurate in both the early and late time regimes. The fracture/matrix interflow equation has been incorporated into an existing unsaturated flow simulator, to serve as a source/sink term for fracture gridblocks. Flow processes are then simulated using only fracture gridblocks in the computational grid. This new lumped-parameter approach has been tested on two problems involving transient flow in fractured/porous media, and compared with simulations performed using explicit discretisation of the matrix blocks. The new procedure seems to accurately simulate flow processes in unsaturated fractured rocks, and typically requires an order of magnitude less computational time than do simulations using fully-discretised matrix blocks. Copyright (C) 1996 Elsevier Science Limited C1 UNIV CALIF BERKELEY, LAWRENCE BERKELEY LAB, DIV EARTH SCI, BERKELEY, CA 94720 USA. OI Zimmerman, Robert/0000-0001-6674-3403 NR 37 TC 45 Z9 45 U1 1 U2 4 PU ELSEVIER SCI LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, OXON, ENGLAND SN 0309-1708 EI 1872-9657 J9 ADV WATER RESOUR JI Adv. Water Resour. PD OCT PY 1996 VL 19 IS 5 BP 317 EP 327 DI 10.1016/0309-1708(96)00007-3 PG 11 WC Water Resources SC Water Resources GA UZ506 UT WOS:A1996UZ50600004 ER PT J AU Gaylord, MS Smith, ZL Lorch, V Blank, ML Snyder, F AF Gaylord, MS Smith, ZL Lorch, V Blank, ML Snyder, F TI Altered platelet-activating factor levels and acetylhydrolase activities are associated with increasing severity of bronchopulmonary dysplasia SO AMERICAN JOURNAL OF THE MEDICAL SCIENCES LA English DT Article DE platelet-activating factor; bronchopulmonary dysplasia; acetylhydrolase; infant chronic lung disease ID RESPIRATORY-DISTRESS SYNDROME; PATHO-PHYSIOLOGY; PAF; INFANTS AB Lipid inflammatory mediators are thought to play an important role in the pathogenesis of neonatal lung injury and bronchopulmonary dysplasia (BPD). Because preliminary studies from the intensive care nursery of the University of Tennessee Medical Center, Knoxville, revealed linear increases in blood platelet-activating factor (PAF) levels in very low birthweight infants developing chronic lung disease and lower cord blood PAF acetylhydrolase activities in premature infants, it was theorized that altered platelet-activating factor levels and PAF acetylhydrolase activities are associated with increasing severity of BPD. Platelet-activating factor levels (blood and tracheal lavage) and PAF acetylhydrolase activities (blood and tracheal lavage) were measured over days 1 to 2, 3 to 5 and 6 to 7 in 16 ventilated infants and weekly in 9 infants with bronchopulmonary dysplasia. Platelet-activating factor values were normalized per nanogram of lavage blood urea nitrogen. Severity of bronchopulmonary dysplasia was estimated using the scoring system developed by Toce. Mean blood and lavage PAF levels and PAF acetylhydrolase activities were compared in infants developing bronchopulmonary dysplasia with those without the disease over the first seven days of life. Infants developing chronic lung disease were significantly smaller and of younger gestational age, In infants with bronchopulmonary dysplasia, higher PAF levels in blood were seen on days 3 to 5, along with increased lavage acetylhydrolase activities on days 1 to 2. Increased levels of PAF in lavage on days 3 to 5 were associated with increasing severity of bronchopulmonary dysplasia, Altered blood and lavage platelet-activating factor levels and PAF acetylhydrolase activities appear to be associated with the pathogenesis and severity of bronchopulmonary dysplasia. C1 UNIV TENNESSEE,GRAD SCH MED,DEPT PEDIAT,KNOXVILLE,TN. OAK RIDGE ASSOCIATED UNIV,DIV MED SCI,OAK RIDGE,TN 37831. FU NCRR NIH HHS [SO7 RR05746-1] NR 15 TC 9 Z9 9 U1 0 U2 0 PU LIPPINCOTT-RAVEN PUBL PI PHILADELPHIA PA 227 EAST WASHINGTON SQ, PHILADELPHIA, PA 19106 SN 0002-9629 J9 AM J MED SCI JI Am. J. Med. Sci. PD OCT PY 1996 VL 312 IS 4 BP 149 EP 154 DI 10.1097/00000441-199610000-00001 PG 6 WC Medicine, General & Internal SC General & Internal Medicine GA VK698 UT WOS:A1996VK69800001 PM 8853062 ER PT J AU Boudreaux, MK Ebbe, S AF Boudreaux, MK Ebbe, S TI Evaluation of ploidy of mature canine megakaryocytes, using Feulgen staining and microspectrophotometry SO AMERICAN JOURNAL OF VETERINARY RESEARCH LA English DT Article ID FLOW CYTOMETRIC ANALYSIS; PLATELET PRODUCTION; VOLUME; SIZE; RAT; THROMBOCYTOPENIA; MARROW AB Objective-To evaluate megakaryocyte size and ploidy, using Feulgen staining and microspectrophotometry, in adult dogs with normal platelet count. Animals-Group A contained 8 and group B contained 11 adult dogs. Procedure-Megakaryocytes were evaluated by light microscopy and staged according to maturation status. Stage-III megakaryocytes were measured and mapped for future relocation. Bone marrow aspirates were destained and restained, using the Feulgen method. Previously identified stage-III megakaryocytes were measured for DNA content, using microspectrophotometry. Results-Megakaryocyte size correlated with ploidy values, and mean sizes within ploidy groups were significantly (P < 0.05) different from each other for both groups, The modal ploidy value oi stage-III megakaryocytes, which represented 18% of the total megakaryocyte population of the combined groups, was 32N. This is in contrast to results of flow cytometric studies, which indicated that the modal ploidy value for ail canine megakaryocytes was 16N. Conclusions-Reasons for the disparate results between microspectrophotometric techniques and flow cytometry include maturation stage of the megakaryocyte population evaluated and percentage oi megakaryocytes within that maturation stage. Flow cytometric methods, which evaluate ail megakaryocytes detectable by antibody, may include cells still capable of DNA synthesis. resulting in a shift in the observed modal ploidy value. Recognition of the difference between canine and human megakaryocyte ploidy distribution is important, particularly in studies in which the dog is used as an animal model for human megakaryocytopoiesis. C1 UNIV CALIF BERKELEY,LAWRENCE BERKELEY LAB,BERKELEY,CA 94720. RP Boudreaux, MK (reprint author), AUBURN UNIV,COLL VET MED,DEPT PATHOBIOL,AUBURN,AL 36849, USA. NR 29 TC 3 Z9 3 U1 0 U2 0 PU AMER VETERINARY MEDICAL ASSOC PI SCHAUMBURG PA 1931 N MEACHAM RD SUITE 100, SCHAUMBURG, IL 60173-4360 SN 0002-9645 J9 AM J VET RES JI Am. J. Vet. Res. PD OCT PY 1996 VL 57 IS 10 BP 1434 EP 1437 PG 4 WC Veterinary Sciences SC Veterinary Sciences GA VK858 UT WOS:A1996VK85800011 PM 8896679 ER PT J AU Risch, TS Brady, MJ AF Risch, TS Brady, MJ TI Trap height and capture success of arboreal small mammals: Evidence from southern flying squirrels (Glaucomys volans) SO AMERICAN MIDLAND NATURALIST LA English DT Article ID HOME-RANGE; VIRGINIA; REPRODUCTION; ABUNDANCE; HABITAT; RODENTS; FLORIDA; ECOLOGY AB Studies of small mammals often use live traps, but the effect of different trapping heights on capture effectiveness of arboreal mammals has not been directly addressed. We compared the capture success of three trap heights (''low''=2 m, ''medium''=4.5-5 m, and ''high''=8-8.5 m) in capturing arboreal mammals. Southern flying squirrels (Glaucomys volans) constituted 86% of the captures. Low traps captured approximately half as many squirrels (15) as either medium (30) or high traps (28), and Individual squirrels were recaptured at a single trap height more often than expected based on chance. Traps at the three heights exhibited significantly heterogeneity in initially capturing individual flying squirrels (ie., previously unmarked squirrels). We reject the hypothesis that trap height does not affect capture success of southern flying squirrels in southern forests during the summer. We discuss the general importance of trap height in studies of mammalian community ecology and conservation. C1 AUBURN UNIV,DEPT ZOOL & WILDLIFE SCI,AUBURN,AL 36849. RP Risch, TS (reprint author), SAVANNAH RIVER ECOL LAB,DRAWER E,AIKEN,SC 29802, USA. NR 32 TC 15 Z9 18 U1 2 U2 6 PU AMER MIDLAND NATURALIST PI NOTRE DAME PA UNIV NOTRE DAME, BOX 369, ROOM 295 GLSC, NOTRE DAME, IN 46556 SN 0003-0031 J9 AM MIDL NAT JI Am. Midl. Nat. PD OCT PY 1996 VL 136 IS 2 BP 346 EP 351 DI 10.2307/2426738 PG 6 WC Biodiversity Conservation; Ecology SC Biodiversity & Conservation; Environmental Sciences & Ecology GA VP307 UT WOS:A1996VP30700013 ER PT J AU Aldstadt, JH Martin, AF AF Aldstadt, JH Martin, AF TI Flow injection method for the determination of arsenic(III) at trace levels in alkaline media SO ANALYST LA English DT Article DE flow injection; potentiometric stripping; arsenite; arsenious acid; 2-chlorovinylarsonous acid; Lewisite ID POTENTIOMETRIC STRIPPING ANALYSIS; METALS; VOLTAMMETRY; ELECTRODE AB A flow injection (FI) method for the determination of trace levels of trivalent arsenicals in environmental samples is reported, The method is applicable to arsenic compounds that can be base hydrolysed to yield arsenious acid, which is then detected electrochemically. By using the constant-current mode of potentiometric stripping analysis (PSA), a method was developed for the determination of arsenious acid in basic media at Ep approximate to -475 mV versus Ag/AgCl (3 mol l(-1) NaCl), The method parameters mere optimized, including pH, supporting electrolyte, deposition potential, deposition time, stripping current and stripping delay, Additionally, possible electrochemical interferences, including As-V, Bi-III, Cd-II, Cu-II, Hg-II, Pb-II, Sb-III, Se-IV and Sn-II, were studied, A detection limit of 0.21 mu g l(-1) was achieved for As-III in aqueous samples (100 mu l) over the range 0.10-50 mu g l(-1) in the stopped-flow FI manifold, The precision (RSD) of the method at 5 mu g l(-1) (n = 8) is < 5%. The method was applied to the indirect determination of dichloro(2-chlorovinyl)arsine (Lewisite), a chemical warfare agent that is difficult to measure in the environment because it rapidly decomposes to form its geminal diol, 2-chlorovinylarsonous acid (CVAA). CVAA can be base hydrolysed to form arsenious acid for detection by FI-PSA. RP Aldstadt, JH (reprint author), ARGONNE NATL LAB,DIV ENVIRONM RES,9700 S CASS AVE,ARGONNE,IL 60439, USA. NR 38 TC 20 Z9 20 U1 1 U2 7 PU ROYAL SOC CHEMISTRY PI CAMBRIDGE PA THOMAS GRAHAM HOUSE, SCIENCE PARK MILTON ROAD, CAMBRIDGE, CAMBS, ENGLAND CB4 4WF SN 0003-2654 J9 ANALYST JI Analyst PD OCT PY 1996 VL 121 IS 10 BP 1387 EP 1391 DI 10.1039/an9962101387 PG 5 WC Chemistry, Analytical SC Chemistry GA VN938 UT WOS:A1996VN93800006 ER PT J AU BarPeled, M Raikhel, NV AF BarPeled, M Raikhel, NV TI A method for isolation and purification of specific antibodies to a protein fused to the GST SO ANALYTICAL BIOCHEMISTRY LA English DT Article ID ER C1 MICHIGAN STATE UNIV,US DOE,PLANT RES LAB,E LANSING,MI 48824. NR 4 TC 63 Z9 63 U1 1 U2 3 PU ACADEMIC PRESS INC JNL-COMP SUBSCRIPTIONS PI SAN DIEGO PA 525 B ST, STE 1900, SAN DIEGO, CA 92101-4495 SN 0003-2697 J9 ANAL BIOCHEM JI Anal. Biochem. PD OCT 1 PY 1996 VL 241 IS 1 BP 140 EP 142 DI 10.1006/abio.1996.0390 PG 3 WC Biochemical Research Methods; Biochemistry & Molecular Biology; Chemistry, Analytical SC Biochemistry & Molecular Biology; Chemistry GA VL138 UT WOS:A1996VL13800023 PM 8921178 ER PT J AU Askari, MDF Maskarinec, MP Smith, SM Beam, PM Travis, CC AF Askari, MDF Maskarinec, MP Smith, SM Beam, PM Travis, CC TI Effectiveness of purge and trap for measurement of volatile organic compounds in aged soils SO ANALYTICAL CHEMISTRY LA English DT Article ID ADSORPTION-DESORPTION; SORPTION; FIELD; KINETICS; 1,2-DIBROMOETHANE; TRICHLOROETHYLENE; CHEMICALS; RESIDUES; VAPOR AB The U.S. EPA-recommended method for measurement of trace levels of volatile organic compounds (VOCs) in soil, purge-and-trap, measures the readily desorbable organic contaminants from soil pore spaces and external soil surfaces. It does not, however, measure contamination that has diffused into internal micropores of soil matrix, Thus, the purge-and-trap method measures only a small fraction of total soil contaminants, especially in long-contaminated soils, where similar to 90-99% of contamination may be in the interior of the soil matrix, We compared three methods for determination of VOCs in aged field samples: purge-and-trap, methanol immersion, and hot solvent extraction, Hot solvent extraction proved to be much more effective than the U.S. EPA-approved purge-and-trap technique, For three long-contaminated soils containing such VOCs as trichloroethene, benzene, toluene, chloroform, methylene chloride, and cis-1,1-dichloroethylene, recovery from purge-and-trap ranged between 1.5 and 41.3% that of hot solvent extraction, Our data show that purge-and-trap may not be the best methodology for measuring soil VOCs concentrations, particularly in aged soils, It is clear from this and previous studies that the best overall choice for soil VOCs measurements is hot solvent extraction, These results also indicate the inefficiency of purge-and-trap as a method for evaluating vapor extraction remediation technology, Our results suggest that the EPA should review the use of the purge-and-trap method for measuring VOCs concentrations in soils. C1 OAK RIDGE NATL LAB,HLTH SCI RES DIV,OAK RIDGE,TN 37830. OAK RIDGE NATL LAB,DIV CHEM & ANALYT SCI,OAK RIDGE,TN 37830. US DOE,WASHINGTON,DC 20585. UNIV TENNESSEE,KNOXVILLE,TN 37996. NR 24 TC 25 Z9 29 U1 1 U2 5 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 SN 0003-2700 J9 ANAL CHEM JI Anal. Chem. PD OCT 1 PY 1996 VL 68 IS 19 BP 3431 EP 3433 DI 10.1021/ac960009c PG 3 WC Chemistry, Analytical SC Chemistry GA VK590 UT WOS:A1996VK59000027 PM 21619276 ER PT J AU Brislawn, CM AF Brislawn, CM TI Classification of nonexpansive symmetric extension transforms for multirate filter banks SO APPLIED AND COMPUTATIONAL HARMONIC ANALYSIS LA English DT Article ID FINITE-LENGTH SIGNALS; COMPACTLY SUPPORTED WAVELETS; LINEAR-PHASE ANALYSIS; PERFECT-RECONSTRUCTION; ORTHONORMAL BASES; FACTORIZATIONS AB This paper describes and classifies a family of invertible discrete-time signal transforms, referred to as symmetric extension trans forms (SET's), for finite-length signals. SET's are algorithms for applying perfect reconstruction multirate filter banks to symmetric extensions of finite-length signals, thereby avoiding the boundary artifacts introduced by simple periodic extension. A key point is when such symmetric decompositions can be formed with no increase in data storage requirements (''nonexpansive decompositions''). Transforms based on three types of symmetric extension and four classes of linear phase filters are analyzed in terms of their memory requirements for general M-channel perfect reconstruction filter banks. The classification is shown to be complete in the sense that it contains all possible nonexpansive SET's. Completeness is then used to deduce design constraints on the construction of nonexpansive M-channel SET's, including new obstructions to the existence of certain classes of filter banks. This paper also forms the principal technical reference on the SET algorithms incorporated in the Federal Bureau of Investigation's digital fingerprint image coding standard. RP Brislawn, CM (reprint author), LOS ALAMOS NATL LAB, GRP CIC 3, LOS ALAMOS, NM 87545 USA. NR 69 TC 55 Z9 55 U1 0 U2 3 PU ACADEMIC PRESS INC JNL-COMP SUBSCRIPTIONS PI SAN DIEGO PA 525 B ST, STE 1900, SAN DIEGO, CA 92101-4495 SN 1063-5203 J9 APPL COMPUT HARMON A JI Appl. Comput. Harmon. Anal. PD OCT PY 1996 VL 3 IS 4 BP 337 EP 357 DI 10.1006/acha.1996.0026 PG 21 WC Mathematics, Applied; Physics, Mathematical SC Mathematics; Physics GA VY420 UT WOS:A1996VY42000004 ER PT J AU Wegrzyn, J Gurevich, M AF Wegrzyn, J Gurevich, M TI Adsorbent storage of natural gas SO APPLIED ENERGY LA English DT Article AB The natural-gas vehicle represents a cost-competitive, lower-emission alternative to the gasoline-fueled vehicle. The immediate challenge that confronts the natural-gas vehicle is extension of its driving range. This paper addresses the question of driving range by reviewing the storage technologies for natural gas. Technical comparisons are made between storage systems for adsorbent, liquefied and compressed natural gas, and estimates are made of the costs associated with refueling with compressed and adsorbent natural gas. We discuss carbon adsorbents, vehicle emissions, designs of storage tanks, cost and safety. For storage-tank system design, we advance the concept that carbon adsorbents, when used with conformable-shaped tanks offer a means of increasing onboard fuel storage and, thereby, the driving range of the vehicle. The cost envelope being assigned to this technology is US$2000 or less per vehicle for 10 gallon gasoline-equivalent storage. For adsorbent natural-gas (ANG), this cost is based on 200 lbs of adsorbent at a purchase price of US$5 lb(-1), a US$600 conformable tank and US$400 for miscellaneous hardware. Because the volumetric storage density of ANG is similar to that of compressed natural-gas (CNG), the benefit of the former is its lower operating pressure. Lower pressures have the advantages of small refueling costs, the availability of conformable tanks and safety. Our suggested solution to the driving-range problem of a natural-gas vehicle is the use of improved adsorbents in a low pressure (500 psi) conformable-shaped storage tank. Published by Elsevier Science Ltd. C1 US DOE,OFF ALTERNAT FUELS,WASHINGTON,DC 20585. RP Wegrzyn, J (reprint author), BROOKHAVEN NATL LAB,DEPT APPL SCI,UPTON,NY 11973, USA. NR 11 TC 83 Z9 88 U1 3 U2 23 PU ELSEVIER SCI LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD, OXON, ENGLAND OX5 1GB SN 0306-2619 J9 APPL ENERG JI Appl. Energy PD OCT PY 1996 VL 55 IS 2 BP 71 EP 83 DI 10.1016/S0306-2619(96)00015-3 PG 13 WC Energy & Fuels; Engineering, Chemical SC Energy & Fuels; Engineering GA WK859 UT WOS:A1996WK85900001 ER PT J AU Aro, CJ AF Aro, CJ TI A stiff ODE preconditioner based on Newton linearization SO APPLIED NUMERICAL MATHEMATICS LA English DT Article DE preconditioning; stiff ODEs; atmospheric chemistry AB The equations of atmospheric chemistry are very stiff and represent the major computational obstacle in the simulation of the chemical and physical processes in the atmosphere. This paper compares two examples of ''preconditioned time differencing'', a technique for constructing cheap time stepping schemes for chemical kinetic ODE systems by eliminating much of the matrix algebra associated with the usual implicit calculation. These preconditioned schemes are also compared with a well known implementation of the popular backward differentiation formulas, and are shown to be a viable alternative to these fully implicit BDF methods applied to chemical kinetics systems. Tests are carried out on a small 2 species system, a box model problem, and a full three-dimensional chemical-radiative-transport model. C1 UNIV CALIF DAVIS,DEPT APPL SCI,DAVIS,CA 95616. RP Aro, CJ (reprint author), LAWRENCE LIVERMORE NATL LAB,COMP RES GRP,POB 808,L-50,LIVERMORE,CA 94551, USA. NR 47 TC 5 Z9 5 U1 0 U2 0 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0168-9274 J9 APPL NUMER MATH JI Appl. Numer. Math. PD OCT PY 1996 VL 21 IS 4 BP 335 EP 352 DI 10.1016/S0168-9274(96)00017-7 PG 18 WC Mathematics, Applied SC Mathematics GA VV962 UT WOS:A1996VV96200001 ER PT J AU Thoe, R AF Thoe, R TI Mechanically simple flat-crystal x-ray source/monochromator SO APPLIED OPTICS LA English DT Article AB The design of a new type of flat-crystal x-ray source/monochromator is discussed. This new design has many advantages over previous designs. It is extremely easy to construct, compact, and portable. It is easy to align and may be adapted to a wide variety of detectors. Its dispersion crystal is easily changed, allowing the same instrument to be used for a very wide range of wavelengths. For example, with a crystal such as LiF (422) its operating range would be in the tens of kilovolts, whereas with a phthalate crystal its range would be from similar to 900 eV to similar to 3 keV. Furthermore the same instrument can be used with a multilayer to extend its useful range almost down to the vacuum UV. (C) 1996 Optical Society of America RP Thoe, R (reprint author), LAWRENCE LIVERMORE NATL LAB,DIV L,LIVERMORE,CA 94550, USA. NR 4 TC 2 Z9 2 U1 0 U2 0 PU OPTICAL SOC AMER PI WASHINGTON PA 2010 MASSACHUSETTS AVE NW, WASHINGTON, DC 20036 SN 0003-6935 J9 APPL OPTICS JI Appl. Optics PD OCT 1 PY 1996 VL 35 IS 28 BP 5714 EP 5721 DI 10.1364/AO.35.005714 PG 8 WC Optics SC Optics GA VJ501 UT WOS:A1996VJ50100035 PM 21127580 ER PT J AU Bennett, LS Lippert, T Furutani, H Fukumura, H Masuhara, H AF Bennett, LS Lippert, T Furutani, H Fukumura, H Masuhara, H TI Laser induced microexplosions of a photosensitive polymer SO APPLIED PHYSICS A-MATERIALS SCIENCE & PROCESSING LA English DT Article ID POLY(METHYL METHACRYLATE) FILM; TRIAZENE POLYMERS; ABLATION; DYNAMICS; DOPANT AB Laser ablation of a photosensitive triazene polymer was studied in a micro region by means of a nanosecond imaging technique. The propagation of a blast wave, 100 ns after laser irradiation, sufficiently matched a planar blast wave model including the decomposed source mass which indicates characteristics of a microexplosion. The measured velocities of the fronts indicates two blast waves: an initially fast unsupported wave around the peak of the laser pulse, and a relatively slow supported wave involving the main component of the decomposition. C1 NATL INST MAT & CHEM RES, TSUKUBA, IBARAKI 305, JAPAN. LOS ALAMOS NATL LAB, LOS ALAMOS, NM 87545 USA. RP Bennett, LS (reprint author), OSAKA UNIV, DEPT APPL PHYS, SUITA, OSAKA 565, JAPAN. RI MASUHARA, Hiroshi/G-3148-2011; Fukumura, Hiroshi/G-4535-2011; Lippert, Thomas/N-2423-2016 NR 22 TC 55 Z9 56 U1 0 U2 2 PU SPRINGER PI NEW YORK PA 233 SPRING ST, NEW YORK, NY 10013 USA SN 0947-8396 EI 1432-0630 J9 APPL PHYS A-MATER JI Appl. Phys. A-Mater. Sci. Process. PD OCT PY 1996 VL 63 IS 4 BP 327 EP 332 DI 10.1007/BF01567321 PG 6 WC Materials Science, Multidisciplinary; Physics, Applied SC Materials Science; Physics GA VM329 UT WOS:A1996VM32900004 ER PT J AU Jones, RW McClelland, JF AF Jones, RW McClelland, JF TI Quantitative depth profiling of layered samples using phase-modulation FT-IR photoacoustic spectroscopy SO APPLIED SPECTROSCOPY LA English DT Article DE phase modulation; photoacoustic spectroscopy; depth profiling ID FILMS AB In phase-modulation FT-IR spectroscopy, all wavelengths in a spectrum are modulated at the same frequency and in phase. This factor makes the use of photoacoustic phase data for depth profiling samples much easier in phase modulation than in rapid scan. A method to quantitatively measure layer thickness by using the phase of a substrate spectrum peak is demonstrated with a series of samples consisting of thin polymer films on substrates. Additions to the basic method are demonstrated that extend its application to cases where the substrate peak is overlapped by a spectrum peak of the surface film. A linear relationship between phase angle and layer thickness extending to thicknesses greater than twice the thermal diffusion length is demonstrated. Representations of phase modulation data as a family of angle-specific spectra, as magnitude vs. phase curves, and as a power spectrum and phase spectrum pair, each of which is useful for different aspects of depth profiling, are discussed. Calculating these representations from a single pair of orthogonal interferograms is described. C1 MTEC PHOTOACOUST INC,AMES,IA 50014. RP Jones, RW (reprint author), IOWA STATE UNIV SCI & TECHNOL,US DOE,AMES LAB,AMES,IA 50011, USA. NR 15 TC 39 Z9 39 U1 0 U2 2 PU SOC APPLIED SPECTROSCOPY PI FREDERICK PA PO BOX 1438, FREDERICK, MD 21701 SN 0003-7028 J9 APPL SPECTROSC JI Appl. Spectrosc. PD OCT PY 1996 VL 50 IS 10 BP 1258 EP 1263 DI 10.1366/0003702963905015 PG 6 WC Instruments & Instrumentation; Spectroscopy SC Instruments & Instrumentation; Spectroscopy GA VR816 UT WOS:A1996VR81600008 ER PT J AU Moreau, F Moreau, SM Hueber, DM Vo-Dinh, T AF Moreau, F Moreau, SM Hueber, DM Vo-Dinh, T TI Fiber-optic remote multisensor system based on an acousto-optic tunable filter (AOTF) SO APPLIED SPECTROSCOPY LA English DT Article DE AOTF; fiber-optic; spectroscopy ID SPECTROSCOPY; FLUORESCENCE; SPECTROMETER; SCATTERING; RESOLUTION; DETECTORS; DEVICES; DESIGN; LIGHT AB This paper describes a new fiber-optic multisensor based on an acousto-optic tunable filter (AOTF) and capable of remote sensing using a multioptical fiber array (MOFA). A two-dimensional charge-coupled device (CCD) was used as a detector, and the AOTF was used as a wavelength selector. Unlike a tunable grating or prism-based monochromator, an AOTP has no moving parts, and an AOTF can be rapidly tuned to any wavelength in its operating range within microseconds. The large aperture of the AOTF allows the optical signal from over 100 fiber-optic sensors to be measured simultaneously. These characteristics, combined with their small size, make AOTFs an important new alternative to conventional monochromators, especially for spectral multisensing and imaging. A prototype fiber-optic multisensor system has been developed, and its feasibility for simultaneous detection of molecular luminescence signal via fiber-optic probes is demonstrated. C1 OAK RIDGE NATL LAB, ADV MONITORING DEV GRP, HLTH SCI RES DIV, OAK RIDGE, TN 37831 USA. NR 39 TC 12 Z9 12 U1 1 U2 2 PU SOC APPLIED SPECTROSCOPY PI FREDERICK PA 5320 SPECTRUM DRIVE SUITE C, FREDERICK, MD 21703 USA SN 0003-7028 J9 APPL SPECTROSC JI Appl. Spectrosc. PD OCT PY 1996 VL 50 IS 10 BP 1295 EP 1300 DI 10.1366/0003702963904917 PG 6 WC Instruments & Instrumentation; Spectroscopy SC Instruments & Instrumentation; Spectroscopy GA VR816 UT WOS:A1996VR81600014 ER PT J AU Goyal, A Norton, DP Christen, DK Specht, ED Paranthaman, M Kroeger, DM Budai, JD He, Q List, FA Feenstra, R Kerchner, HR Lee, DF Hatfield, E Martin, PM Mathis, J Park, C AF Goyal, A Norton, DP Christen, DK Specht, ED Paranthaman, M Kroeger, DM Budai, JD He, Q List, FA Feenstra, R Kerchner, HR Lee, DF Hatfield, E Martin, PM Mathis, J Park, C TI Epitaxial superconductors on rolling-assisted biaxially-textured substrates (RABiTS): A route towards high critical current density wire SO APPLIED SUPERCONDUCTIVITY LA English DT Article AB Fabrication of epitaxial, high-J(c), biaxially aligned YBCO thick films on rolling-assisted biaxially-textured substrates (RABiTS) is summarized. The RABiTS technique utilizes standard thermomechanical processing to obtain long lengths of flexible, biaxially oriented substrates with smooth surfaces (rms similar to 50 nm). The strong biaxial texture of the metal (in-plane 6-7 degrees FWHM) is conferred to the superconductor by deposition of intermediate metal and/or oxide layers which serve both as a chemical as well as a structural buffer. Epitaxial YBCO films grown using laser ablation on RABiTS(TM) have critical current densities exceeding 10(6) A cm(-2) at 77 K in zero-field and have field dependences similar to epitaxial films on single crystal ceramic substrates. The texture of the base metal has been achieved in lengths over 1 m and scaleable techniques are being pursued to deposit epitaxial multilayers. Deposited conductors made using this technique offer a potential route for the fabrication of long lengths of high-J(c) wire capable of carrying high currents in high magnetic fields and at elevated temperatures. (C) 1998 Elsevier Science Ltd. All rights reserved. C1 Oak Ridge Natl Lab, Div Met & Ceram, Oak Ridge, TN 37831 USA. Oak Ridge Natl Lab, Div Solid State, Oak Ridge, TN 37831 USA. Oak Ridge Natl Lab, Div Chem & Analyt Sci, Oak Ridge, TN 37831 USA. Univ Tennessee, Knoxville, TN 37996 USA. Oak Ridge Inst Sci & Educ, Oak Ridge, TN 37831 USA. RP Goyal, A (reprint author), Oak Ridge Natl Lab, Div Met & Ceram, POB 2008, Oak Ridge, TN 37831 USA. RI Christen, David/A-9709-2008; Yoon, Sejin/F-7637-2013; Specht, Eliot/A-5654-2009; Paranthaman, Mariappan/N-3866-2015; Budai, John/R-9276-2016 OI Specht, Eliot/0000-0002-3191-2163; Paranthaman, Mariappan/0000-0003-3009-8531; Budai, John/0000-0002-7444-1306 NR 51 TC 100 Z9 102 U1 3 U2 26 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLAND SN 0964-1807 J9 APPL SUPERCOND JI Appl. Supercond. PD OCT-NOV PY 1996 VL 4 IS 10-11 BP 403 EP 427 DI 10.1016/S0964-1807(97)00029-X PG 25 WC Materials Science, Multidisciplinary; Physics, Applied; Physics, Condensed Matter SC Materials Science; Physics GA V3044 UT WOS:000169555300002 ER PT J AU Arendt, PN Foltyn, SR Groves, JR DePaula, RF Dowden, PC Roper, JM Coulter, JY AF Arendt, PN Foltyn, SR Groves, JR DePaula, RF Dowden, PC Roper, JM Coulter, JY TI YBCO/YSZ coated conductors on flexible Ni alloy substrates SO APPLIED SUPERCONDUCTIVITY LA English DT Article AB A coating system for the deposition of in-plane oriented yttria-stabilized zirconia (YSZ) template films on 1 cm wide flexible metal substrates is presented. In static mode, the system is capable of producing high quality template films on 20 cm substrate lengths. In a continuous coating mode, the system is capable of producing good quality template films on 1.1 m substrate lengths. Superconducting YBa2Cu3O7-delta (YBCO) films subsequently deposited onto these template films have demonstrated critical currents (I-c) of 200 A (1.5 cm length), 70 A (12 cm length) and 4 A (1 m length). (C) 1998 Elsevier Science Ltd. All rights reserved. C1 Univ Calif Los Alamos Natl Lab, Div Mat Sci & Technol, Los Alamos, NM 87545 USA. RP Arendt, PN (reprint author), Univ Calif Los Alamos Natl Lab, Div Mat Sci & Technol, Los Alamos, NM 87545 USA. NR 9 TC 39 Z9 40 U1 0 U2 0 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLAND SN 0964-1807 J9 APPL SUPERCOND JI Appl. Supercond. PD OCT-NOV PY 1996 VL 4 IS 10-11 BP 429 EP 434 DI 10.1016/S0964-1807(97)00041-0 PG 6 WC Materials Science, Multidisciplinary; Physics, Applied; Physics, Condensed Matter SC Materials Science; Physics GA V3044 UT WOS:000169555300003 ER PT J AU Rosenwaks, Y Thacker, BR Nozik, AJ AF Rosenwaks, Y Thacker, BR Nozik, AJ TI The GaAs/GaInP2 heterojunction for studying photoinduced charge transfer processes SO APPLIED SURFACE SCIENCE LA English DT Article; Proceedings Paper CT 2nd International Conference on Photo-Excited Processes and Applications CY SEP 17-21, 1995 CL JERUSALEM, ISRAEL ID SEMICONDUCTOR AB We report on a novel semiconductor photoelectrode structure that exhibits a dependence of the photocurrent-voltage characteristics an the concentration of a nonadsorbed, outer-sphere redox acceptor. The structure consists of a thin (30-50 Angstrom) epilayer of GaInP2 grown on a thick (5000 Angstrom)p-GaAs epilayer. The thin GaInP2 layer produces very good passivation of the GaAs surface resulting in surface recombination velocities less than 200 cm/s, while al the same time permitting efficient electron transfer, presumably via field-assisted tunneling and/or thermionic emission. C1 NATL RENEWABLE ENERGY LAB,GOLDEN,CO 80401. RP Rosenwaks, Y (reprint author), TEL AVIV UNIV,FAC ENGN,DEPT PHYS ELECT,IL-69978 TEL AVIV,ISRAEL. NR 19 TC 2 Z9 2 U1 0 U2 1 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0169-4332 J9 APPL SURF SCI JI Appl. Surf. Sci. PD OCT PY 1996 VL 106 BP 396 EP 401 DI 10.1016/S0169-4332(96)00380-7 PG 6 WC Chemistry, Physical; Materials Science, Coatings & Films; Physics, Applied; Physics, Condensed Matter SC Chemistry; Materials Science; Physics GA VT407 UT WOS:A1996VT40700066 ER PT J AU Poles, E Goldberg, SY Fainberg, B Huppert, D Hanna, MC Rosenwaks, Y AF Poles, E Goldberg, SY Fainberg, B Huppert, D Hanna, MC Rosenwaks, Y TI The effects of carrier transport on the photoluminescence of degenerate electron-hole plasma in GaAs epilayers SO APPLIED SURFACE SCIENCE LA English DT Article; Proceedings Paper CT 2nd International Conference on Photo-Excited Processes and Applications CY SEP 17-21, 1995 CL JERUSALEM, ISRAEL ID SURFACE-RECOMBINATION VELOCITY; HOT CARRIERS; PICOSECOND RELAXATION; SEMICONDUCTORS; LUMINESCENCE; INTERFACES; CDS; INP AB Time resolved photoluminescence (TRPL) is employed to study photogenerated electron-hole plasma expansion under strong illumination conditions in thin GaAs epilayer. We have observed spectral dependencies similar to ones which are usually observed on carrier's cooling, However, in our case they are caused by the diffusion of the degenerate electron-hole plasma perpendicular to the crystal surface. We have studied the influence of the degenerated carrier transport on the luminescence characteristics of bulk samples, both experimentally and by simulations. We suggest using this method to measure the transport coefficients of both degenerate and hot excess carriers in semiconductor structures. C1 TEL AVIV UNIV,SCH CHEM,RAYMOND & BEVERLY SACKLER FAC EXACT SCI,IL-69978 RAMAT AVIV,ISRAEL. NATL RENEWABLE ENERGY LAB,GOLDEN,CO 80401. TEL AVIV UNIV,FAC ENGN,IL-69978 RAMAT AVIV,ISRAEL. NR 23 TC 0 Z9 0 U1 1 U2 3 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0169-4332 J9 APPL SURF SCI JI Appl. Surf. Sci. PD OCT PY 1996 VL 106 BP 457 EP 465 DI 10.1016/S0169-4332(96)00413-8 PG 9 WC Chemistry, Physical; Materials Science, Coatings & Films; Physics, Applied; Physics, Condensed Matter SC Chemistry; Materials Science; Physics GA VT407 UT WOS:A1996VT40700076 ER PT J AU Waugh, WJ Baker, DA Kastens, MK Abraham, JA AF Waugh, WJ Baker, DA Kastens, MK Abraham, JA TI Calibration precision of capacitance and neutron soil water content gauges in arid soils SO ARID SOIL RESEARCH AND REHABILITATION LA English DT Article DE capacitance moisture gauge; field calibration; neutron moisture gauge; soil water content ID MOISTURE MEASUREMENT; BALANCE; REGIONS; SITES; COVER AB Resonant frequency capacitance (RFC) gauges have been marketed as a replacement for neutron thermalization (NT) gauges for monitoring soil water content in access tubes. Regulatory restrictions have increased the cost of maintaining and operating NT gauges. Commercial RFC gauges have performed satisfactorily for some agronomic applications when tested in relatively uniform or recompacted soil profiles. We compared the calibration statistics of RFC and NT gauges in three heterogeneous arid soils initially for all data, and then for data poststratified by texture, bulk density, and salinity. Our experimental design included measurements of soil water profiles in paired wet and dry plots, one at field capacity and the other near the seasonal low. Coefficients of determination (r(2)) for linear calibrations of the RFC gauge ranged from 0.19 to 0.85. The response of the resonant frequency difference measured by the RFC probe to soil water content (theta) was masked by sensitivity primarily to soil salinity, but also to soil bulk density (rho) and soil texture. The RFC gauge performed best in a thick sandy loam soil with low salinity levels and fairly uniform rho. Values of r(2) for linear calibrations of the NT gauge versus theta ranged from 0.84 to 0.94. The NT gauge calibrations were little influenced by soil salinity, rho, or soil texture. Standard errors of theta estimates [SE(E theta)] were up to 7 times higher for the RFC gauge than for the NT gauge (0.025-0.093 and 0.014-0.026 cm(3) cm(-3) for RFC and NT gauges, respectively). These results support continued use of NT gauges for soil water monitoring in access tubes at undisturbed arid sites. RP Waugh, WJ (reprint author), US DOE,ENVIRONM SCI LAB,ROY F WESTON INC,POB 14000,GRAND JCT,CO 81502, USA. NR 23 TC 1 Z9 2 U1 1 U2 2 PU TAYLOR & FRANCIS PI BRISTOL PA 1900 FROST ROAD, SUITE 101, BRISTOL, PA 19007-1598 SN 0890-3069 J9 ARID SOIL RES REHAB JI Arid Soil Res. Rehabil. PD OCT-DEC PY 1996 VL 10 IS 4 BP 391 EP 401 PG 11 WC Environmental Sciences; Soil Science SC Environmental Sciences & Ecology; Agriculture GA WD425 UT WOS:A1996WD42500008 ER PT J AU Ball, R Meixner, MM Keto, E Arens, JF Jernigan, JG AF Ball, R Meixner, MM Keto, E Arens, JF Jernigan, JG TI Thermal dust imaging of the ultracompact H II region G29.96-0.02 SO ASTRONOMICAL JOURNAL LA English DT Article ID PHYSICAL-PROPERTIES; INFRARED SOURCES; EMISSION; STARS; MODELS; SPECTROPHOTOMETRY; DYNAMICS; SPECTRA; BUBBLES; GRAINS AB We have obtained mid-infrared images of the ultracompact H II region G29.96-0.02 at 1 '' resolution. These include three broadband images at 8.5, 9.7, and 12.0 mu m and three narrowband images covering the spectrum around the 12.8 mu m [Ne II] emission line. The appearance of the object in all bands is basically similar to the arcuate or ''cometary'' shape seen in previously published high-resolution radio maps. At our shortest wavelength of 8.5 mu m, the faint, diffuse emission from the cometary ''tail'' is enhanced compared to its brightness at other wavelengths. Taking advantage of well-matched passbands, we have used the ratio between the images at 12.0 and at 8.5 mu m to construct maps of the dust color temperature T-d and emission optical depth tau(em) in the object. The optical depth is sharply peaked along a long, thin ridge near the leading edge of the cometary are. The shape of this ridge is nearly identical to that seen in the high-resolution 2 cm maps, strongly suggesting that the dust which is warm enough to emit at 8 and 12 mu m is inside or extremely close to the zone of ionized gas in G29.96-0.02. This conclusion is further bolstered by the essentially identical distribution of the [Ne II] emission and the thermal dust continuum at adjacent wavelengths. The key feature of the dust temperature map is its lack of marked variation. The great majority of the nebula shows temperatures between 190 and 240 K. The small variations that do occur present a clear pattern. At the center of the ridge of high tau(rmem), T-d is around 210 K. Moving outward to the wings of the are, the temperature falls slowly to about 190 K at the extreme ends. On the other hand, moving back along the symmetry axis into the nebula's tail we find that mean temperatures increase to around 230 K, with a good deal of scatter. We have tried modeling these temperature variations using some simple concepts derived from earlier radiative transfer work on related objects, together with a published model of G29.96-0.02 as a bow shock. Unlike our previous success in applying such a framework to our observations of the ultracompact source G5.89-0.39, the models fail to match the temperature pattern in G29.96-0.02. Of several possible processes which may account for the discrepancy, an increased abundance of small grains caused by shock processing of the dust seems to present the fewest obvious difficulties. (C) 1996 American Astronomical Society. C1 LAWRENCE LIVERMORE NATL LAB, INST GEOPHYS & PLANETARY PHYS, LIVERMORE, CA 94550 USA. UNIV ILLINOIS, DEPT ASTROPHYS, URBANA, IL 61801 USA. SMITHSONIAN ASTROPHYS OBSERV, CAMBRIDGE, MA 02138 USA. UNIV CALIF BERKELEY, SPACE SCI LAB, BERKELEY, CA 94720 USA. NR 47 TC 11 Z9 11 U1 0 U2 0 PU IOP PUBLISHING LTD PI BRISTOL PA DIRAC HOUSE, TEMPLE BACK, BRISTOL BS1 6BE, ENGLAND SN 0004-6256 J9 ASTRON J JI Astron. J. PD OCT PY 1996 VL 112 IS 4 BP 1645 EP 1658 DI 10.1086/118130 PG 14 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA VK840 UT WOS:A1996VK84000026 ER PT J AU Hofner, S Fleischer, AJ Gauger, A Feuchtinger, MU Dorfi, EA Winters, JM Sedlmayr, E AF Hofner, S Fleischer, AJ Gauger, A Feuchtinger, MU Dorfi, EA Winters, JM Sedlmayr, E TI Dynamical models of atmospheres of long-period variables: A comparative study SO ASTRONOMY & ASTROPHYSICS LA English DT Article DE hydrodynamics; shock waves; methods, numerical; stars, circumstellar matter; stars, AGB and post-AGB ID CIRCUMSTELLAR DUST SHELLS; C-STARS; RADIATION HYDRODYNAMICS; KAPPA-MECHANISM; WINDS; GROWTH; EVAPORATION AB Numerical models for atmospheres of carbon-rich long-period variables (LPVs) obtained by two different codes are compared with regard to the radial structure of the circumstellar shell, its dynamics and the propagation of shock waves, the dust formation and its effects on the dynamics and thermodynamics of the atmosphere as well as the mass loss rates and the outflow velocities. The general features of the models such as the formation of discrete dust layers, the occurrence of multiperiodicity or the dust-induced IE-mechanism in purely dust-driven winds are the same in both cases while a detailed quantitative comparison of special model calculations demonstrates certain effects caused by the different numerical schemes. Nevertheless we find that the two modelling methods give remarkably similar results with respect to the complex physical system under consideration. C1 TECH UNIV BERLIN, INST ASTRON & ASTROPHYS, D-10623 BERLIN, GERMANY. UNIV VIENNA, INST ASTRON, A-1180 VIENNA, AUSTRIA. LOS ALAMOS NATL LAB, DIV THEORET, GRP T4, LOS ALAMOS, NM 87545 USA. NR 22 TC 19 Z9 19 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 OCT PY 1996 VL 314 IS 1 BP 204 EP 208 PG 5 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA VM335 UT WOS:A1996VM33500026 ER PT J AU Kaastra, JS Mewe, R Liedahl, DA Singh, KP White, NE Drake, SA AF Kaastra, JS Mewe, R Liedahl, DA Singh, KP White, NE Drake, SA TI Emission measure analysis methods: The corona of AR lacertae revisited SO ASTRONOMY & ASTROPHYSICS LA English DT Article DE methods, data analysis; stars, abundances; stars, coronae; stars, individual, AR Lac; X-rays, stars ID EUV SPECTROSCOPY; COOL STARS; SOLAR AB A simultaneous ROSAT/ASCA observation of the RS CVn binary AR Lac has been re-analysed using updated calculations for the plasma emission. Several analysis methods are applied that serve to reconstruct the emission measure distribution of AR Lac. In particular we describe the regularisation method, a Chebyshev polynomial method, a clean algorithm, a genetic algorithm and a method based upon broadened discrete temperature components. We confirm earlier results that the abundance are non-solar; for most elements (O, Mg, Si, S, Ar, Ca and Fe), we find abundances that are consistent with 1/3 of the solar photospheric abundances. The abundances of Ne (0.7) and Ni (1.1) are somewhat larger. The emission measure analysis shows that there are at least two and probably three temperature components: a cool, intermediate and hot component at temperatures of 0.6, 1 and 2.4 keV, respectively. The cool component is rather narrow (less than 50 % relative width) and there is no significant emission below 0.3 keV down to our detection limit at about 0.03 keV. The intermediate and hot component may be separate structures, but could also be the dominant features of a more continuous emission measure distribution between 1-4 keV. High-temperature emission above 5 keV is limited to at most 5 % of the total. C1 LAWRENCE LIVERMORE NATL LAB, DIV 5, LIVERMORE, CA 94550 USA. NASA, GODDARD SPACE FLIGHT CTR, HIGH ENERGY ASTROPHYS LAB, GREENBELT, MD 20771 USA. RP Kaastra, JS (reprint author), SRON, SPACE RES LAB, SORBONNELAAN 2, NL-3584 CA UTRECHT, NETHERLANDS. RI White, Nicholas/B-6428-2012 OI White, Nicholas/0000-0003-3853-3462 NR 30 TC 72 Z9 72 U1 1 U2 2 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 OCT PY 1996 VL 314 IS 2 BP 547 EP 557 PG 11 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA VN758 UT WOS:A1996VN75800020 ER PT J AU Evrard, AE Metzler, CA Navarro, JF AF Evrard, AE Metzler, CA Navarro, JF TI Mass estimates of X-ray clusters SO ASTROPHYSICAL JOURNAL LA English DT Article DE dark matter; galaxies, clusters, general; hydrodynamics; X-rays, galaxies ID DISSIPATIVE GALAXY FORMATION; DARK-MATTER; HUBBLE CONSTANT; COMA CLUSTER; SIMULATIONS; DYNAMICS; EVOLUTION; GAS; NUCLEOSYNTHESIS; SUBSTRUCTURE AB We use cosmological gasdynamic simulations to investigate the accuracy of galaxy cluster mass estimates based on X-ray observations. The experiments follow the formation of clusters in different cosmological models and include the effects of gravity, pressure gradients, and hydrodynamical shocks. A subset of our ensemble also allows for feedback of mass and energy from galactic winds into the intracluster medium. We find that mass estimates based on the hydrostatic, isothermal beta-model are remarkably accurate when evaluated at radii where the cluster mean density is between 500 and 2500 times the critical density. At lower densities, radial temperature information becomes important. In the quoted radial regime, the distribution of the estimated-to-true mass ratio, derived from 174 artificial images constructed from the simulations, is nearly unbiased and has a standard deviation of 14%-29%. The scatter can be considerably reduced (to 8%-15%) by using an alternative mass estimator that exploits the tightness of the mass-temperature relation found in the simulations. The improvement over beta-model estimates is due to the elimination of the variance contributed by the gas outer slope parameter. We discuss these findings and their implications for recent measurements of cluster baryon fractions. C1 NASA, FERMILAB ASTROPHYS CTR, BATAVIA, IL 60510 USA. UNIV ARIZONA, STEWARD OBSERV, TUCSON, AZ 85721 USA. UNIV CALIF SANTA BARBARA, INST THEORET PHYS, SANTA BARBARA, CA 93106 USA. RP UNIV MICHIGAN, DEPT PHYS, ANN ARBOR, MI 48109 USA. OI Evrard, August/0000-0002-4876-956X NR 62 TC 559 Z9 559 U1 0 U2 0 PU IOP PUBLISHING LTD PI BRISTOL PA TEMPLE CIRCUS, TEMPLE WAY, BRISTOL BS1 6BE, ENGLAND SN 0004-637X EI 1538-4357 J9 ASTROPHYS J JI Astrophys. J. PD OCT 1 PY 1996 VL 469 IS 2 BP 494 EP 507 DI 10.1086/177798 PN 1 PG 14 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA VJ788 UT WOS:A1996VJ78800006 ER PT J AU Koo, DC Vogt, NP Phillips, AC Guzman, R Wu, KL Faber, SM Gronwall, C Forbes, DA Illingworth, GD Groth, EJ Davis, M Kron, RG Szalay, AS AF Koo, DC Vogt, NP Phillips, AC Guzman, R Wu, KL Faber, SM Gronwall, C Forbes, DA Illingworth, GD Groth, EJ Davis, M Kron, RG Szalay, AS TI Redshift z similar to 1 field galaxies observed with the Keck Telescope and the Hubble Space Telescope SO ASTROPHYSICAL JOURNAL LA English DT Article DE cosmology, observations; galaxies, distances and redshifts; galaxies, evolution; galaxies, formation; galaxies, structure ID POPULATION; EVOLUTION AB We report results based on 35 new spectroscopic redshifts obtained with the Reck Telescope for field galaxies that also have photometry and morphology from survey images taken by the refurbished Hubble Space Telescope. A sample of 24 redshifts for galaxies fainter than I = 22 has a median redshift of z similar to 0.81. This result is inconsistent with the lower median redshift of z similar to 0.6 predicted by the ''maximal merger models'' of Carlberg, which otherwise fit existing data. The data match an extrapolation of the Canada France Redshift Survey (CFRS), as well as predictions of certain mild luminosity-evolution models. Nearly half of the redshifts lie in two structures at z similar or equal to 0.81 and z similar or equal to 1.0, showing the presence of high-density concentrations spanning scales of similar to 1 h(-1) Mpc, i.e., the size of groups. We find emission lines or the presence of possible neighbors in seven of nine otherwise luminous galaxies with red central regions at redshifts beyond z similar to 0.7. We also note a diversity of morphological types among blue galaxies at z similar to 1, including small compact galaxies, ''chains,'' and ''blue nucleated galaxies.'' These morphologies are found among local, but generally less luminous, galaxies. Distant blue galaxies also include apparently normal late-type spirals. These findings could imply modest bursts of star formation caused by mergers or interactions of small, gas-rich galaxies with each other or with larger, well-formed galaxies. This first glimpse of very faint z similar to 1 field galaxies of diverse colors and morphologies suggests that a mixture of physical processes is at work in the formation and evolution of faint held galaxies. C1 PRINCETON UNIV,DEPT PHYS,PRINCETON,NJ 08544. UNIV CALIF BERKELEY,DEPT ASTRON,BERKELEY,CA 94720. FERMILAB NATL ACCELERATOR LAB,BATAVIA,IL 60510. JOHNS HOPKINS UNIV,DEPT PHYS & ASTRON,BALTIMORE,MD 21218. RP Koo, DC (reprint author), UNIV CALIF SANTA CRUZ,UNIV CALIF OBSERV,LICK OBSERV,BOARD STUDIES ASTRON & ASTROPHYS,SANTA CRUZ,CA 95064, USA. NR 41 TC 64 Z9 64 U1 0 U2 0 PU UNIV CHICAGO PRESS PI CHICAGO PA 5720 S WOODLAWN AVE, CHICAGO, IL 60637 SN 0004-637X J9 ASTROPHYS J JI Astrophys. J. PD OCT 1 PY 1996 VL 469 IS 2 BP 535 EP & DI 10.1086/177802 PN 1 PG 12 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA VJ788 UT WOS:A1996VJ78800010 ER PT J AU Long, KS Mauche, CW Raymond, JC Szkody, P Mattei, JA AF Long, KS Mauche, CW Raymond, JC Szkody, P Mattei, JA TI EUVE observations of U Geminorum in outburst SO ASTROPHYSICAL JOURNAL LA English DT Article DE binaries, eclipsing; novae, cataclysmic variables; stars, individual (U Geminorum); ultraviolet, stars ID X-RAY-EMISSION; EXTREME-ULTRAVIOLET EXPLORER; CATACLYSMIC VARIABLES; ACCRETION DISKS; DWARF NOVAE; BOUNDARY-LAYER; URSAE-MAJORIS; LIGHT CURVES; WHITE-DWARF; SS CYGNI AB We have observed U Gem during the peak and declining phases of a wide outburst in 1993 December with the Extreme Ultraviolet Explorer (EUVE) satellite. At peak, U Gem was one of the brightest EUV sources in the sky. The spectrum of the source is complex. Fitted to a blackbody spectrum, the apparent temperature at peak is similar to 140,000 K, the luminosity is similar to 4 x 10(34)(D/90 pc)(2) ergs s(-1), and the minimum size of the emitting region is comparable to that of the white dwarf (WD). If the EUV emission arises primarily from the boundary layer, then the boundary layer luminosity in U Gem is comparable to the disk luminosity. The EUV source is partially eclipsed at orbital phases 0.6-0.8. The eclipse spectrum, which we associate with a wind emerging from the vicinity of the white dwarf, is dominated by emission features. The identification of these emission features with transitions expected in a relatively cool (T < 160,000 K), photoionized plasma helps to resolve a controversy concerning the ionization state of winds of dwarf novae. The EUV lines arise from the dominant ionization states of the wind, and their strengths suggest that the wind mass-loss rate, at least in U Gem, is a substantial fraction of the WD accretion rate. C1 LAWRENCE LIVERMORE NATL LAB,LIVERMORE,CA 94450. HARVARD SMITHSONIAN CTR ASTROPHYS,CAMBRIDGE,MA 02138. UNIV WASHINGTON,DEPT ASTRON,SEATTLE,WA 98195. AMER ASSOC VARIABLE STAR OBSERVERS,CAMBRIDGE,MA 02138. RP Long, KS (reprint author), SPACE TELESCOPE SCI INST,3700 SAN MARTIN DR,BALTIMORE,MD 21218, USA. NR 70 TC 55 Z9 55 U1 0 U2 2 PU UNIV CHICAGO PRESS PI CHICAGO PA 5720 S WOODLAWN AVE, CHICAGO, IL 60637 SN 0004-637X J9 ASTROPHYS J JI Astrophys. J. PD OCT 1 PY 1996 VL 469 IS 2 BP 841 EP 853 DI 10.1086/177832 PN 1 PG 13 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA VJ788 UT WOS:A1996VJ78800040 ER PT J AU Klein, RI Jernigan, JG Arons, J Morgan, EH Zhang, W AF Klein, RI Jernigan, JG Arons, J Morgan, EH Zhang, W TI GRO J1744-28 and Scorpius X-1: First evidence for photon bubble oscillations and turbulence SO ASTROPHYSICAL JOURNAL LA English DT Article DE accretion; hydrodynamics; instabilities; stars, neutron AB We discuss our recent Rossi X-Ray Timing Explorer (RXTE) observations of GRO J1744-28, which discovered quasi-periodic oscillations (QPOs) of the intensities in the energy band 3-12 keV during observations starting on 1996 January 18.77 UT. We have found that the power spectrum in the frequency band 5-1000 Hz consists of two red-noise components that can be characterized by two power laws, each with an index of -5/3 and a QPO peak centered at 40 Hz. We suggest that the power peak is due to a newly discovered form of turbulence in the accretion column of super-Eddington accretion-powered pulsars driven by photon bubble instabilities. These instabilities give rise to strong power peaks at frequencies characteristic of photon diffusion and bubble coalescence in the highly nonlaminar accretion column resulting in photon bubble oscillations (PBOs). The relationship between the rms amplitude of the PBOs and the intensity is in qualitative agreement with observations. Our calculations also suggest that the observed high-frequency red-noise component with a -5/3 power-law index from 40 to 600 Hz is the first evidence of photon bubble turbulence in the accretion column of an X-ray pulsar. Recent RXTE observations of Sco X-l have found high-frequency QPOs at 1100 and 830 Hz. We show that PBOs at these frequencies are a natural consequence of photon bubble instabilities. We also show that the rms amplitudes of the calculated PBOs at these frequencies are consistent with the observations. We predict that further RXTE observations of Sco X-l should reveal additional PBOs at 2000 and 2600 Hz as well as a broadband continuum spectrum with a -5/3 power law, extending from 3000 to several times 10(4) Hz. C1 LAWRENCE LIVERMORE NATL LAB, LIVERMORE, CA 94550 USA. LAWRENCE LIVERMORE NATL LAB, INST GEOPHYS & PLANETARY PHYS, LIVERMORE, CA 94550 USA. UNIV CALIF BERKELEY, THEORET ASTROPHYS CTR, BERKELEY, CA 94720 USA. UNIV CALIF BERKELEY, SPACE SCI LAB, BERKELEY, CA 94720 USA. UNIV CALIF BERKELEY, DEPT PHYS, BERKELEY, CA 94720 USA. MIT, CTR SPACE RES, CAMBRIDGE, MA 02139 USA. GODDARD SPACE FLIGHT CTR, HIGH ENERGY ASTROPHYS LAB, GREENBELT, MD 20771 USA. RP Klein, RI (reprint author), UNIV CALIF BERKELEY, DEPT ASTRON, 601 CAMPBELL HALL, BERKELEY, CA 94720 USA. NR 11 TC 33 Z9 33 U1 0 U2 1 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 OCT 1 PY 1996 VL 469 IS 2 BP L119 EP L123 DI 10.1086/310277 PN 2 PG 5 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA VJ790 UT WOS:A1996VJ79000013 ER PT J AU Li, H Fenimore, EE AF Li, H Fenimore, EE TI Log-normal distributions in gamma-ray burst time histories SO ASTROPHYSICAL JOURNAL LA English DT Article DE gamma rays, bursts AB We propose a new, simple but powerful algorithm to analyze the gamma-ray burst temporal structures based on identifying nonstatistical variations (''peaks'') in the time histories. Detailed analyses of the bursts from the third BATSE catalog show that similar to 30 bursts have more than 20 peaks individually. Upon identifying most of the peaks in those bursts. we show that the peak fluence S-i, and peak interval delta(i) distributions within each burst are consistent with log-normal distributions. Furthermore, we show that Gaussian (in linear space) and power-law distributions for peak fluences are ruled out, as is the Poisson distribution for peak intervals. RP Li, H (reprint author), LOS ALAMOS NATL LAB,D436,LOS ALAMOS,NM 87545, USA. NR 13 TC 49 Z9 52 U1 0 U2 0 PU UNIV CHICAGO PRESS PI CHICAGO PA 5720 S WOODLAWN AVE, CHICAGO, IL 60637 SN 0004-637X J9 ASTROPHYS J JI Astrophys. J. PD OCT 1 PY 1996 VL 469 IS 2 BP L115 EP L118 DI 10.1086/310275 PN 2 PG 4 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA VJ790 UT WOS:A1996VJ79000012 ER PT J AU Lim, MA Clapp, AC Devlin, MJ Figueiredo, N Gundersen, JO Hanany, S Hristov, VV Lange, AE Lubin, PM Meinhold, PR Richards, PL Staren, JW Smoot, GF Tanaka, ST AF Lim, MA Clapp, AC Devlin, MJ Figueiredo, N Gundersen, JO Hanany, S Hristov, VV Lange, AE Lubin, PM Meinhold, PR Richards, PL Staren, JW Smoot, GF Tanaka, ST TI The second measurement of anisotropy in the cosmic microwave background radiation at 0.degrees 5 scales near the star mu Pegasi SO ASTROPHYSICAL JOURNAL LA English DT Article DE cosmic microwave background; cosmology, observations ID ANGULAR SCALES; MAPS AB During the fifth flight of the Microwave Anisotropy Experiment (MAX5), we revisited a region with significant dust emission near the star mu Pegasi. A 3.5 cm(-1) low-frequency channel has been added since the previous measurement (Meinhold et al. 1993a). The data in each channel clearly show structure correlated with IRAS 100 mu m dust emission. The spectrum of the structure in the 6, 9, and 14 cm(-1) channels is described by I-v proportional to nu(beta)B(nu) (T-dust), where beta = 1.3 and T-dust = 19 K and B-v is the Planck function. However, this model predicts a smaller amplitude in the 3.5 cm(-1) band than is observed. Considering only linear combinations of the data independent of the best-fit foreground spectrum for the three lower channels, we find an upper limit to CMBR fluctuations of Delta T/T = (C(l)l(l + 1)/2 pi)(1/2) less than or equal to 1.3 x 10(-5) at the 95% confidence level. The result is for a flat-band power spectrum and does not include a 10% uncertainty in calibration. It is consistent with our previous observation in the region. C1 UNIV CALIF SANTA BARBARA,DEPT PHYS,SANTA BARBARA,CA 93106. UNIV CALIF BERKELEY,DEPT PHYS,BERKELEY,CA 94720. ESCOLA FED ENGN ITAJUBA,DEPT QUIM & FIS,BR-37500000 ITAJUBA,MG,BRAZIL. INST NACL PESQUISAS ESPACIAIS,DIV ASTROFIS,BR-12201970 S JOSE CAMPOS,BRAZIL. LAWRENCE BERKELEY LAB,DIV PHYS,BERKELEY,CA 94720. RP Lim, MA (reprint author), NSF,CTR PARTICLE ASTROPHYS,BERKELEY,CA 94720, USA. RI Figueiredo, Newton/F-9976-2011 NR 24 TC 39 Z9 39 U1 0 U2 0 PU UNIV CHICAGO PRESS PI CHICAGO PA 5720 S WOODLAWN AVE, CHICAGO, IL 60637 SN 0004-637X J9 ASTROPHYS J JI Astrophys. J. PD OCT 1 PY 1996 VL 469 IS 2 BP L69 EP L72 DI 10.1086/310276 PN 2 PG 4 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA VJ790 UT WOS:A1996VJ79000001 ER PT J AU Chambers, KC Miley, GK VanBreugel, WJM Huang, JS AF Chambers, KC Miley, GK VanBreugel, WJM Huang, JS TI Ultra-steep-spectrum radio sources .1. 4C objects SO ASTROPHYSICAL JOURNAL SUPPLEMENT SERIES LA English DT Article DE galaxies, active; galaxies, distances and redshifts; galaxies, jets; galaxies, structure; polarization; radio continuum, galaxies; surveys ID HIGH-REDSHIFT; OPTICAL IDENTIFICATIONS; VLA OBSERVATIONS; GALAXIES; ALIGNMENT; QUASARS; JETS; DEPOLARIZATION; LUMINOSITY; EMISSION AB We present radio total intensity and polarization images and complete optical identifications of a representative sample of ultra-steep-spectrum 4C objects. The radio morphologies are all resolved into double lobes or triples with cores. The radio polarization intensity morphologies are strikingly asymmetric. The optical identifications consist of galaxies in distant clusters (0.4 < z < 1.0), quasars, and high-redshift (z > 1) radio galaxies. We identify several (1 < z < 2) cluster candidates, and faint candidates for very high redshift radio galaxies. C1 STERREWACHT LEIDEN, NL-2300 RA LEIDEN, NETHERLANDS. LAWRENCE LIVERMORE NATL LAB, INST GEOPHYS & PLANETARY PHYS, LIVERMORE, CA 94550 USA. RP UNIV HAWAII, INST ASTRON, 2680 WOODLAWN DR, HONOLULU, HI 96822 USA. NR 77 TC 47 Z9 47 U1 0 U2 0 PU IOP PUBLISHING LTD PI BRISTOL PA TEMPLE CIRCUS, TEMPLE WAY, BRISTOL BS1 6BE, ENGLAND SN 0067-0049 EI 1538-4365 J9 ASTROPHYS J SUPPL S JI Astrophys. J. Suppl. Ser. PD OCT PY 1996 VL 106 IS 2 BP 215 EP 246 DI 10.1086/192337 PG 32 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA WE459 UT WOS:A1996WE45900001 ER PT J AU Chambers, KC Miley, GK VanBreugel, WJM Bremer, MAR Huang, JS Trentham, NA AF Chambers, KC Miley, GK VanBreugel, WJM Bremer, MAR Huang, JS Trentham, NA TI Ultra-steep-spectrum radio sources .2. Radio, infrared, optical, and HST imaging of high-redshift 4C objects SO ASTROPHYSICAL JOURNAL SUPPLEMENT SERIES LA English DT Article DE galaxies, active; galaxies, distances and redshifts; galaxies, jets; Galaxy, evolution; infrared, galaxies; polarization; radio continuum, galaxies ID STANDARD STARS; GALAXIES; ALIGNMENT; DEPOLARIZATION; LUMINOSITY; CONTINUUM; LIGHT; DUST AB We present radio, infrared, optical, and HST imaging data on eight high-redshift (z > 2) ultra-steep-spectrum 4C radio sources. The radio polarization morphologies are highly asymmetric, indicating large rotation measures across the objects. The optical morphologies are all aligned with the radio axis. The multicolor images show strong asymmetric gradients in the color of the continuum along the radio axes. No optical emission is detected from the radio lobes. Narrowband images of the redshifted Ly alpha emission show that the emission-line morphology is generally aligned with the radio source but does not necessarily correspond to the apparent morphology of the rest-frame ultraviolet continuum. C1 STERREWACHT LEIDEN,NL-2300 RA LEIDEN,NETHERLANDS. LAWRENCE LIVERMORE NATL LAB,INST GEOPHYS & PLANETARY PHYS,LIVERMORE,CA 94550. STERREWACHT LEIDEN,NL-3584 CA UTRECHT,NETHERLANDS. SRON,NL-3584 CA UTRECHT,NETHERLANDS. RP Chambers, KC (reprint author), UNIV HAWAII,INST ASTRON,2680 WOODLAWN DR,HONOLULU,HI 96822, USA. NR 51 TC 59 Z9 59 U1 0 U2 0 PU UNIV CHICAGO PRESS PI CHICAGO PA 5720 S WOODLAWN AVE, CHICAGO, IL 60637 SN 0067-0049 J9 ASTROPHYS J SUPPL S JI Astrophys. J. Suppl. Ser. PD OCT PY 1996 VL 106 IS 2 BP 247 EP 279 DI 10.1086/192338 PG 33 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA WE459 UT WOS:A1996WE45900002 ER PT J AU Meyers, TP Hall, ME Lindberg, SE Kim, K AF Meyers, TP Hall, ME Lindberg, SE Kim, K TI Use of the modified Bowen-ratio technique to measure fluxes of trace gases SO ATMOSPHERIC ENVIRONMENT LA English DT Article ID AIR-SURFACE EXCHANGE; DRY DEPOSITION; VOLATILE MERCURY; DECIDUOUS FOREST; PLANT CANOPY; NITRIC-ACID; VAPOR; RATES; SOIL AB The modified Bowen-ratio (MBR) technique is a micrometeorological method that can be used to estimate air-surface exchange rates, providing differences in concentrations between two heights can be resolved. Application of the MBR method requires that fluxes and gradients for at least one scalar entity be measured in order to directly compute the exchange coefficient k, which is assumed to be applicable for all scalars. Direct measurements of fluxes (eddy correlation) and gradients for CO2 and H2O were made during three experiments. Measurements were made at the forest floor of a boreal forest, over a lake surface, and at the forest floor of a leafless deciduous forest. Data from these experiments were used to examine the equality of H2O and CO2 exchange coefficients. The mean difference between the exchange coefficients for CO2 and H2O was not found to be statistically different from zero. Uncertainties in the determination of k associated with gradient measurements and sampling strategies are evaluated. The MBR technique is then used to assess the air-surface exchange rates of gas-phase mercury. Although the acceptably good agreement between the exchange coefficients for CO2 and H2O does not prove they are equal to k for Hg, greater confidence is assumed in the determination of Hg fluxes than just using k for heat. Copyright (C) 1996 Published by Elsevier Science Ltd C1 OAK RIDGE ASSOCIATED UNIV, OAK RIDGE, TN USA. OAK RIDGE NATL LAB, DIV ENVIRONM SCI, OAK RIDGE, TN 37831 USA. KOREA NATL UNIV EDUC, DEPT ENVIRONM SCI, KOREA CHINA CTR ATMOS RES, CHOONGBUK 363391, SOUTH KOREA. RP Meyers, TP (reprint author), NOAA, ATMOSPHER TURBULENCE & DIFFUS DIV, POB 2456, OAK RIDGE, TN 37831 USA. RI Meyers, Tilden/C-6633-2016 NR 37 TC 70 Z9 73 U1 1 U2 14 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLAND SN 1352-2310 J9 ATMOS ENVIRON JI Atmos. Environ. PD OCT PY 1996 VL 30 IS 19 BP 3321 EP 3329 DI 10.1016/1352-2310(96)00082-9 PG 9 WC Environmental Sciences; Meteorology & Atmospheric Sciences SC Environmental Sciences & Ecology; Meteorology & Atmospheric Sciences GA VB161 UT WOS:A1996VB16100009 ER PT J AU Taha, H AF Taha, H TI Modeling impacts of increased urban vegetation on ozone air quality in the South Coast Air Basin SO ATMOSPHERIC ENVIRONMENT LA English DT Article DE mesoscale modeling; photochemistry; urban airshed model; urban vegetation ID EMISSION RATES; TEMPERATURE; ALBEDO; LIGHT AB This paper analyzes the possible effects of increased urban vegetation on the ozone air quality in California's South Coast Air Basin (SoCAB). Air quality impacts are accounted for through mesoscale meteorological and photochemical modeling of a late-August period. The simulations indicate that the net effect of increased urban vegetation is a decrease in ozone concentrations if the additional vegetation (trees) are low emitters. Hydrocarbon-emitting tree Species have negative impacts on air quality. Episode-specific simulations in this study suggest that trees emitting roughly more than 2 mu g g(-1) h(-1) of isoprene (micrograms of isoprene per gram dry-leaf mass per hour) and 1 mu g g(-1)h(-1) of mono terpenes should not be introduced in the SoCAB. Copyright (C) 1996 Elsevier Science Ltd RP Taha, H (reprint author), UNIV CALIF BERKELEY,LAWRENCE BERKELEY LAB,MS 90-2000,BERKELEY,CA 94720, USA. NR 26 TC 83 Z9 96 U1 1 U2 17 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD, ENGLAND OX5 1GB SN 1352-2310 J9 ATMOS ENVIRON JI Atmos. Environ. PD OCT PY 1996 VL 30 IS 20 BP 3423 EP 3430 DI 10.1016/1352-2310(96)00035-0 PG 8 WC Environmental Sciences; Meteorology & Atmospheric Sciences SC Environmental Sciences & Ecology; Meteorology & Atmospheric Sciences GA VD986 UT WOS:A1996VD98600006 ER PT J AU Dials, GE AF Dials, GE TI Disposal of long-lived radioactive waste in the USA - Safe management of defense-generated waste SO ATW-INTERNATIONALE ZEITSCHRIFT FUR KERNENERGIE LA English DT Article AB In the United States, radioactive waste has arisen in the military as well as the peaceful uses of nuclear energy. The long-lived military waste contains high percentages of alpha-emitting transuranium isotopes. In 1979, Congress decided on a site in the State of New Mexico for building the Waste Isolation Pilot Plant (WIPP) in which R&D work was to be conducted in preparation of a repository. In 1992, the US Congress installed the Environmental Protection Agency (EPA) as regulation for WIPP. In December 1993, the Department of Energy (DOE) set up the Carlsbad Area Office. According to estimates of June 1996, 58,000 m(3) of waste containing transuranium elements (TRUW), with a surface dose below 2 mSv/h, is located at twenty generator sites, while eight of these sites hold 3600 m(3) with lip to 10 Sv/h. By the year 2022, another 54,000 m(3) (< 2 mSv/h) and 24,000 m(3) (< 10 Sv/h) are going to arise. The total volume of TRUW will rise to 139,600 m(3). In addition, another 88,000 m(3) is expected to come from decommissioning and site decontamination. WIPP can accommodate a maximum of 175,584 m(3). The repository was built in rock salt at a depth of 650 m. RP Dials, GE (reprint author), US DOE,CARLSBAD AREA OFF,CARLSBAD,NM, USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU VERLAGSGRP HANDELSBLATT GMBH PI DUSSELDORF PA POSTFACH 10 11 02, D-40002 DUSSELDORF, GERMANY SN 1431-5254 J9 ATW-INT Z KERNENERG JI ATW-Int. Zeit. Kernenerg. PD OCT PY 1996 VL 41 IS 10 BP 635 EP 637 PG 3 WC Nuclear Science & Technology SC Nuclear Science & Technology GA VQ950 UT WOS:A1996VQ95000004 ER PT J AU Stout, MJ Workman, KV Workman, JS Duffey, SS AF Stout, MJ Workman, KV Workman, JS Duffey, SS TI Temporal and ontogenetic aspects of protein induction in foliage of the tomato, Lycopersicon esculentum SO BIOCHEMICAL SYSTEMATICS AND ECOLOGY LA English DT Article DE Lycopersicon esculentum; oxidative enzymes; proteinase inhibitors; polyphenol oxidase; peroxidase; lipoxygenase; induced phytochemistry; induced resistance ID DEFENSE; HERBIVORE; INHIBITOR; RESPONSES; OXIDASE; QUALITY; PLANTS; TREES AB Damage to foliage of the tomato, Lycopersicon esculentum, causes the induction of proteinase inhibitors and of the oxidative enzymes polyphenol oxidase. peroxidase, and lipoxygenase. The time courses of induction of these proteins by feeding of two caterpillar species (Manduca sexta and Heli-coverpa zee) were studied in a series of experiments. In another series of experiments, the effects of plant age on the inducibility of these proteins were studied. In the time course experiments, induction of proteinase inhibitors and oxidative enzymes in the damaged leaflet was rapid, with higher protein activities evident in damaged leaflets within 12-24 h of damage, depending on the enzyme and the species of insect used to damage the plant. Systemic induction of proteinase inhibitors was also rapid. but systemic induction of polyphenol oxidase was delayed relative to systemic induction of proteinase inhibitors, possibly because high constitutive polyphenol oxidase activities obscured expression of systemic induction at earlier time points. Lipoxygenase and peroxidase were not induced systemically. Induction of all proteins persisted for at least 21 days. In the phenology experiments, inducibility of all proteins decreased in magnitude and was less consistent as plants aged. The results of these experiments exemplify the numerous constraints on induction in tomato plants. Knowledge of these physiological constraints is important to an understanding of the ecological role and causal basis of induced resistance. Copyright (C) 1996 Elsevier Science Ltd C1 LAWRENCE LIVERMORE NATL LAB,DEPT ENTOMOL,DAVIS,CA 95616. NR 25 TC 31 Z9 33 U1 2 U2 8 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD, ENGLAND OX5 1GB SN 0305-1978 J9 BIOCHEM SYST ECOL JI Biochem. Syst. Ecol. PD OCT-DEC PY 1996 VL 24 IS 7-8 BP 611 EP 625 DI 10.1016/S0305-1978(97)81205-7 PG 15 WC Biochemistry & Molecular Biology; Ecology; Evolutionary Biology SC Biochemistry & Molecular Biology; Environmental Sciences & Ecology; Evolutionary Biology GA WD697 UT WOS:A1996WD69700003 ER PT J AU Mao, B Vyas, RR Hingerty, BE Broyde, S Basu, AK Patel, DJ AF Mao, B Vyas, RR Hingerty, BE Broyde, S Basu, AK Patel, DJ TI Solution conformation of the N-(deoxyguanosin-8-y1)-1-aminopyrene ([AP]dG) adduct opposite dC in a DNA duplex SO BIOCHEMISTRY LA English DT Article ID ULTIMATE CARCINOGEN N-ACETOXY-N-2-ACETYLAMINOFLUORENE; ENVIRONMENTAL MUTAGEN 1-NITROPYRENE; COVALENTLY ATTACHED BENZOPYRENE; INDUCED FRAMESHIFT MUTAGENESIS; DEOXYADENOSINE N-6-AMINO GROUP; NUCLEAR-MAGNETIC-RESONANCE; MODIFIED DEOXYGUANOSINE; BASE DISPLACEMENT; ESCHERICHIA-COLI; COMPUTATIONAL CHARACTERIZATION AB Combined NMR-molecular mechanics computational studies were undertaken on the C-8-deoxyguanosine adduct formed by the carcinogen 1-nitropyrene embedded in the d(C5-[AP]G6-C7). d(G16-C17-G18) sequence context in a 11-mer duplex, with dC opposite the modified deoxyguanosine, The exchangeable and nonexchangeable protons of the aminopyrene moiety and the nucleic acid were assigned following analysis of two-dimensional NMR data sets in H2O and D2O solution. There was a general broadening of several proton resonances for the three nucleotide d(G16-C17-G18) segment positioned opposite the [AP]dG6 lesion site resulting in weaker NOEs involving these protons in the adduct duplex. The solution conformation of the [AP]dG . dC 11-mer duplex has been determined by incorporating intramolecular and intermolecular proton-proton distances defined by upper and lower bounds deduced from NOESY spectra as restraints in molecular mechanics computations in torsion angle space. The aminopyrene ring of [AP]dG6 is intercalated into the DNA helix between intact Watson-rick dC5 . dG18 and dC7 . dG16 base pairs. The modified deoxyguanosine ring of [AP]dG6 is displaced into the major groove and stacks with the major groove edge of dC5 in the adduct duplex. Both carbon and proton chemical shift data for the sugar resonances of the modified deoxyguanosine residue are consistent with a syn glycosidic torsion angle for the [AP]dG6 residue. The dC17 base on the partner strand is displaced from the center of the helix toward the major groove as a consequence of the aminopyrene ring intercalation into the helix. This base-displaced intercalative structure of the [AP]dG . dC 11-mer duplex exhibits several unusually shifted proton resonances which can be accounted for by the ring current contributions of the deoxyguanosinyl and pyrenyl rings of the [AP]dG6 adduct. In summary, intercalation of the aminopyrene moiety is accompanied by displacement of both [AP]dG6 and the partner dC17 into the major groove in the [AP]dG . dC 11-mer duplex. C1 MEM SLOAN KETTERING CANC CTR,CELLULAR BIOCHEM & BIOPHYS PROGRAM,NEW YORK,NY 10021. UNIV CONNECTICUT,DEPT CHEM,STORRS,CT 06269. OAK RIDGE NATL LAB,HLTH SCI RES DIV,OAK RIDGE,TN 37831. NYU,DEPT BIOL,NEW YORK,NY 10003. FU NCI NIH HHS [CA-28038, CA-49982]; NIEHS NIH HHS [ES-05695, R01 ES009127] NR 73 TC 44 Z9 44 U1 0 U2 1 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 SN 0006-2960 J9 BIOCHEMISTRY-US JI Biochemistry PD OCT 1 PY 1996 VL 35 IS 39 BP 12659 EP 12670 DI 10.1021/bi961078o PG 12 WC Biochemistry & Molecular Biology SC Biochemistry & Molecular Biology GA VK594 UT WOS:A1996VK59400003 PM 8841109 ER PT J AU Gao, F Qin, H Simpson, MC Shelnutt, JA Knaff, DB Ondrias, MR AF Gao, F Qin, H Simpson, MC Shelnutt, JA Knaff, DB Ondrias, MR TI Isolation and characterization of vibrational spectra of individual heme active sites in cytochrome bc(1) complexes from Rhodobacter capsulatus SO BIOCHEMISTRY LA English DT Article ID C-TYPE CYTOCHROMES; RESONANCE RAMAN-SPECTROSCOPY; PROTONMOTIVE Q-CYCLE; BC1 COMPLEX; SPHAEROIDES; OXIDOREDUCTASE; MUTAGENESIS; INHIBITORS; BACTERIA; RESIDUES AB Resonance Raman spectra of bc(1) complexes and isolated c(1) subunit from Rhodobacter capsulatus have been obtained using a variety of excitation wavelengths. Spectra obtained via Q-band excitation of bc(1) complexes in different redox states were separated to yield the individual vibrational spectra of each of the three heme active sites, Hemes b(H) and c(1) exhibit vibrational spectra typical of b- and c-type hemes, respectively, In contrast, the spectrum of heme b(L) is anomalous with respect to those of other hemes b. The isolated spectra were also used to assess the effects of inhibitor binding on the local structural environments of the hemes. Neither antimycin nor myxothiazol binding produces dramatic structural perturbations at the hemes. Heme ct is completely unaffected by the presence of either inhibitor. The vibrational spectra of hemes b(H) and b(L) are slightly altered by antimycin and myxothiazol binding, respectively. C1 UNIV NEW MEXICO,DEPT CHEM,ALBUQUERQUE,NM 87131. TEXAS TECH UNIV,DEPT CHEM & BIOCHEM,LUBBOCK,TX 79409. SANDIA NATL LABS,FUEL SCI DEPT,ALBUQUERQUE,NM 87185. RI Shelnutt, John/A-9987-2009; Simpson, Miriam/C-4237-2011 OI Shelnutt, John/0000-0001-7368-582X; FU NIGMS NIH HHS [GM 33330] NR 44 TC 8 Z9 8 U1 0 U2 3 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 SN 0006-2960 J9 BIOCHEMISTRY-US JI Biochemistry PD OCT 1 PY 1996 VL 35 IS 39 BP 12812 EP 12819 DI 10.1021/bi960419v PG 8 WC Biochemistry & Molecular Biology SC Biochemistry & Molecular Biology GA VK594 UT WOS:A1996VK59400018 PM 8841124 ER PT J AU Hartmann, GD AF Hartmann, GD TI Genetic variation in a subterranean mammal, Scalopus aquaticus (Insectivora: Talpidae) SO BIOLOGICAL JOURNAL OF THE LINNEAN SOCIETY LA English DT Article DE allozyme variation; electrophoresis; mole ID GENUS CTENOMYS RODENTIA; POCKET GOPHERS; SYSTEMATICS; MOLES AB Allozyme variation was examined for 382 moles (Scalopus aquaticus) collected from 16 localities located within a 23 km(2) area in South Carolina, U.S.A. Of 26 presumptive loci that were scored for all moles, 8 (30.8%) were observed to be polymorphic. Mean direct-count heterozygosity was 7.2%, c. 75% higher than the mean value reported for mammals. The findings of this study do not support the hypothesis that more purely subterranean species of mammals will exhibit levels of allozyme variation lower than those of above-ground species. (C) 1996 The Linnean Society of London C1 UNIV NEW MEXICO, DEPT BIOL, ALBUQUERQUE, NM 87131 USA. UNIV NEW MEXICO, MUSEUM SW BIOL, ALBUQUERQUE, NM 87131 USA. RP Hartmann, GD (reprint author), SAVANNAH RIVER ECOL LAB, DRAWER E, AIKEN, SC 29802 USA. NR 33 TC 1 Z9 1 U1 1 U2 3 PU WILEY-BLACKWELL PI HOBOKEN PA 111 RIVER ST, HOBOKEN 07030-5774, NJ USA SN 0024-4066 EI 1095-8312 J9 BIOL J LINN SOC JI Biol. J. Linnean Soc. PD OCT PY 1996 VL 59 IS 2 BP 115 EP 125 PG 11 WC Evolutionary Biology SC Evolutionary Biology GA VP324 UT WOS:A1996VP32400001 ER PT J AU Luo, P Nieh, TG AF Luo, P Nieh, TG TI Preparing hydroxyapatite powders with controlled morphology SO BIOMATERIALS LA English DT Article DE spherical hydroxyapatite; chromatography columns; particle size; spray drying ID CALCIUM AB We developed a synthesis method for hydroxyapatite particles with different morphologies. The process involved chemical precipitation and spray drying, which produced spherical, agglomerated hydroxyapatite granules with controlled particle sizes and structures. These granules contained nanoparticles with an average crystalline size of about 10 nm. We controlled the morphologies of the granules by adjusting the spray-drying conditions, such as the volume fraction of feed slurry and the atomization pressure. The spray-dried granules were doughnut shapes, solid spheres, or hollow spheres, and their sizes were controlled by varying the atomization pressure and the concentration of the feed slurry. (C) 1996 Elsevier Science Limited. RP Luo, P (reprint author), LAWRENCE LIVERMORE NATL LAB,7000 EAST AVE,POB 808,LIVERMORE,CA 94550, USA. RI Nieh, Tai-Gang/G-5912-2011 OI Nieh, Tai-Gang/0000-0002-2814-3746 NR 13 TC 76 Z9 80 U1 5 U2 32 PU ELSEVIER SCI LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD, OXON, ENGLAND OX5 1GB SN 0142-9612 J9 BIOMATERIALS JI Biomaterials PD OCT PY 1996 VL 17 IS 20 BP 1959 EP 1964 DI 10.1016/0142-9612(96)00019-1 PG 6 WC Engineering, Biomedical; Materials Science, Biomaterials SC Engineering; Materials Science GA VJ535 UT WOS:A1996VJ53500006 PM 8894088 ER PT J AU Dragutan, I Caragheorgheopol, A Chiraleu, F Mehlhorn, RJ AF Dragutan, I Caragheorgheopol, A Chiraleu, F Mehlhorn, RJ TI New amino-nitroxide spin labels SO BIOORGANIC & MEDICINAL CHEMISTRY LA English DT Article ID MYOGLOBIN; OXYGEN; IDENTIFICATION; DIMERIZATION; RESONANCE; RADICALS; KINETICS; PROTEINS; CELLS AB Stable free mono- and diradicals containing reactive primary or secondary amino groups in the side-chain have been synthesized by transesterification of amino-substituted esters with paramagnetic alcohols or from spin-labeled acid derivatives and amines. In the second approach the new radical 18 (1-oxyl-3-(2-bromoethoxycarbonyl)-2,2,5,5-tetramethylpyrroline) is proposed as an efficient alkylating species. The nitroxides described are pH-sensitive spin probes and spin labels potentially useful for a diversity of ESR applications in chemistry and biology. New spin-labeled tyramine 16 (N-(1-oxyl-3-carbonyl-2,2,5,5-tetramethylpyrroline) tyramine) was successfully employed in a novel assay of protein oxidative damage. Copyright (C) 1996 Elsevier Science Ltd C1 ROMANIAN ACAD,INST ORGAN CHEM,BUCHAREST,ROMANIA. ROMANIAN ACAD,INST PHYS CHEM,BUCHAREST,ROMANIA. UNIV CALIF BERKELEY,LAWRENCE BERKELEY LAB,BERKELEY,CA 94720. NR 48 TC 2 Z9 2 U1 2 U2 2 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD, ENGLAND OX5 1GB SN 0968-0896 J9 BIOORGAN MED CHEM JI Bioorg. Med. Chem. PD OCT PY 1996 VL 4 IS 10 BP 1577 EP 1583 DI 10.1016/0968-0896(96)00150-2 PG 7 WC Biochemistry & Molecular Biology; Chemistry, Medicinal; Chemistry, Organic SC Biochemistry & Molecular Biology; Pharmacology & Pharmacy; Chemistry GA VU125 UT WOS:A1996VU12500002 ER PT J AU Discher, DE Mohandas, N AF Discher, DE Mohandas, N TI Kinematics of red cell aspiration by fluorescence-imaged microdeformation SO BIOPHYSICAL JOURNAL LA English DT Article ID HUMAN-ERYTHROCYTE MEMBRANE; LATERAL MOBILITY; MECHANICAL-PROPERTIES; PROTEIN; BAND-3; DEFORMATION; DIFFUSION; SPECTRIN; ASSOCIATION; SURFACE AB Maps of fluorescing red cell membrane components on a pipette-aspirated projection are quantitated in an effort to elucidate and unify the heterogeneous kinematics of deformation. Transient gradients of diffusing fluorescent lipid first demonstrate the fluidity of an otherwise uniform-density bilayer and corroborate a ''universal'' calibration scale for relative surface density. A steep but smooth and stable gradient in the densities of the skeleton components spectrin, actin, and protein 4.1 is used to estimate large elastic strains along the aspirated skeleton. The deformation fields are argued to be an unhindered response to loading in the surface normal direction. Density maps intermediate to those of the compressible skeleton and fluid bilayer are exhibited by particular transmembrane proteins (e.g., Band 3) and yield estimates for the skeleton-connected fractions. Such connected proteins appear to occupy a significant proportion of the undeformed membrane surface and can lead to steric exclusion of unconnected integral membrane proteins from regions of network condensation. Consistent with membrane repatterning kinematics in reversible deformation, final vesiculation of the projection tip produces a cell fragment concentrated in freely diffusing proteins but depleted of skeleton. C1 SIMON FRASER UNIV, DEPT PHYS, BURNABY, BC V5A 156, CANADA. UNIV CALIF BERKELEY, LAWRENCE BERKELEY LAB, DIV LIFE SCI, BERKELEY, CA 94720 USA. UNIV CALIF BERKELEY, JOINT GRAD GRP BIOENGN, BERKELEY, CA USA. FU NHLBI NIH HHS [R01 HL31579-13]; NIDDK NIH HHS [P01 DK32094-09] NR 44 TC 55 Z9 56 U1 0 U2 12 PU CELL PRESS PI CAMBRIDGE PA 600 TECHNOLOGY SQUARE, 5TH FLOOR, CAMBRIDGE, MA 02139 USA SN 0006-3495 EI 1542-0086 J9 BIOPHYS J JI Biophys. J. PD OCT PY 1996 VL 71 IS 4 BP 1680 EP 1694 PG 15 WC Biophysics SC Biophysics GA VK295 UT WOS:A1996VK29500003 PM 8889146 ER PT J AU Coulter, RL Martin, TJ AF Coulter, RL Martin, TJ TI Effects of stability on the profiles of vertical velocity and its variance in katabatic flow SO BOUNDARY-LAYER METEOROLOGY LA English DT Article; Proceedings Paper CT 7th International Symposium on Acoustic Remote Sensing and Associated Techniques of the Atmosphere and Oceans CY OCT 03-07, 1994 CL NOAA ENVIRONM TECHNOL LAB, BOULDER, CO SP Int Soc Acoust Remote Sensing HO NOAA ENVIRONM TECHNOL LAB ID VALLEY; WINDS AB The atmospheric katabatic flow in the foothills of the Front Range of the Rocky Mountains has been monitored by a network of towers and sodars for several years as part of the Atmospheric Studies in COmplex Terrain (ASCOT) program. We used three years of data from the network to explore the dependence on surface cooling and channeling by winds above the canyon of (1) profiles of the mean and variance of the vertical (perpendicular to the geopotential) component of motion and (2) the mean component of the wind perpendicular to the local terrain of Coal Creek Canyon. Previously we found that the magnitude of the near-surface temperature difference decreases with increasing surface cooling in light winds, apparently because of increasing turbulence caused when increasing drainage winds interact with surface topography. The variance of vertical velocity exhibits three types of vertical profiles, corresponding to different cooling rates and external wind speeds. The mean variance was found to depend strongly on a locally derived Richardson number. RP Coulter, RL (reprint author), ARGONNE NATL LAB,9700 S CASS AVE,ARGONNE,IL 60439, USA. NR 5 TC 6 Z9 6 U1 0 U2 1 PU KLUWER ACADEMIC PUBL PI DORDRECHT PA SPUIBOULEVARD 50, PO BOX 17, 3300 AA DORDRECHT, NETHERLANDS SN 0006-8314 J9 BOUND-LAY METEOROL JI Bound.-Layer Meteor. PD OCT PY 1996 VL 81 IS 1 BP 23 EP 33 DI 10.1007/BF00119397 PG 11 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA WB605 UT WOS:A1996WB60500004 ER PT J AU Withers, MM Aster, RC Young, CJ Chael, EP AF Withers, MM Aster, RC Young, CJ Chael, EP TI High-frequency analysis of seismic background noise as a function of wind speed and shallow depth SO BULLETIN OF THE SEISMOLOGICAL SOCIETY OF AMERICA LA English DT Article ID EASTERN KAZAKHSTAN; CALIFORNIA; EVENTS; TEXAS; ARRAY AB We used a deep (1500 m) cased borehole near the town of Datil in west-central New Mexico to study high-frequency (>1 Hz) seismic noise characteristics. The remote site had very low levels of cultural noise, but strong winds (winter and spring) made the site an excellent candidate to study the effects of wind noise on seismograms. Along with a three-component set of surface sensors (Teledyne Geotech GS-13), a vertical borehole seismometer (GS-28) was deployed at a variety of depths (5, 43, and 85 m) to investigate signal and noise variations. Wind speed was measured with an anemometer. Event-triggered and time-triggered data streams were recorded on a RefTek 72-02 data acquisition system located at the site. Our data show little cultural noise and a strong correlation between wind speed and seismic background noise. The minimum wind speed at which the seismic background noise appears to be influenced varies with depth: 3 m/sec at the surface, 3.5 m/sec at 43 m in depth, and 4 m/sec at 85 m in depth. For wind speed below 3 to 4 m/sec, we observe omni-directional background noise that is coherent at frequencies below 15 Hz. This coherence is destroyed when wind speeds exceed 3 to 4 m/sec. We use a test event (M(d) similar to 1.6) and superimposed noise to investigate signal-to-noise ratio (SNR) improvement with sensor depth. For the low Q valley fill of the Datil borehole (DBH) site, we have found that SNR can be improved by as much as 20 to 40 dB between 23 and 55 Hz and 10 to 20 dB between 10 and 20 Hz, by deploying at a 43-m depth rather than at the surface. At the surface, there is little signal above noise in the 23- to 55-Hz frequency band for wind speeds greater than 8 m/sec. Thus, high-frequency signal information that is lost at the surface can be recorded by deploying at the relatively shallow depth of 40 m. Because we observe only minor further reductions in seismic background noise (SBN) at deeper depths, 40 m is likely to be a reasonable deployment depth for other high-frequency-monitoring sites in similar environmental and geologic conditions. C1 NEW MEXICO INST MIN & TECHNOL,GEOPHYS RES CTR,SOCORRO,NM 87801. SANDIA NATL LABS,DEPT 6116,ALBUQUERQUE,NM 87185. SANDIA NATL LABS,DEPT 9236,ALBUQUERQUE,NM 87185. RP Withers, MM (reprint author), NEW MEXICO INST MIN & TECHNOL,DEPT EARTH & ENVIRONM SCI,SOCORRO,NM 87801, USA. RI Aster, Richard/E-5067-2013 OI Aster, Richard/0000-0002-0821-4906 NR 21 TC 62 Z9 63 U1 1 U2 11 PU SEISMOLOGICAL SOC AMER PI EL CERRITO PA PLAZA PROFESSIONAL BLDG, SUITE 201, EL CERRITO, CA 94530 SN 0037-1106 J9 B SEISMOL SOC AM JI Bull. Seismol. Soc. Amer. PD OCT PY 1996 VL 86 IS 5 BP 1507 EP 1515 PG 9 WC Geochemistry & Geophysics SC Geochemistry & Geophysics GA VP989 UT WOS:A1996VP98900023 ER PT J AU Young, CJ Chael, EP Withers, MM Aster, RC AF Young, CJ Chael, EP Withers, MM Aster, RC TI A comparison of the high-frequency (>1 Hz) surface and subsurface noise environment at three sites in the United States SO BULLETIN OF THE SEISMOLOGICAL SOCIETY OF AMERICA LA English DT Article ID SEISMIC NOISE; EASTERN KAZAKHSTAN; TEXAS AB Surface and subsurface high-frequency (>1 Hz) noise data were recorded using nearly identical instrumentation at three widely separated sites in the United States (Amarillo, Texas; Datil, New Mexico; and Pinedale, Wyoming) for extended periods of time under varying wind conditions. While the sites are geologically distinct, the near-surface noise environments have many common features that we believe may be due in large part to the presence of a surficial layer of highly attenuative unconsolidated material at each site. Noise levels seen at or near the surface (5 m or less) are much higher (up to 30 dB) and much more variable (power range up to 44 dB) than those seen at depth (the smallest range was 9 dB for 1951 m at Amarillo). The greatest gains in noise level reduction are realized within the first 100 m and probably much shallower (< similar to 10 m). Regardless of the wind profile or local lithology, all sites show an excellent correlation between increased noise levels and higher wind speed, even at significant depths (367 m at Amarillo). Wind-generated noise is broadband (at least 15 to 60 Hz) and apparently nonlinear, increasing dramatically when a wind speed threshold is exceeded (3 to 4 m/sec within a few meters of the surface; as high as 8 m/sec at a depth of a few hundred meters). It is possible to be essentially completely shielded from the wind-generated component of seismic noise by deploying instruments at sufficient depth, but we observed this only for the two deepest deployments (1219 and 1951 m, both at Amarillo). Reducing the wind profile at the surface, however, can yield similar reductions for a much smaller cost. Cultural or ''workday'' noise, if present (depending on the remoteness of the site), is typically much weaker (10 dB or less) than wind noise but may propagate very effectively to great depths and therefore could be of concern for very deep deployments where wind is not a factor. C1 SANDIA NATL LABS,DEPT 9236,ALBUQUERQUE,NM 87185. NEW MEXICO INST MIN & TECHNOL,DEPT EARTH & ENVIRONM SCI & GEOPHYS RES,SOCORRO,NM 87801. RP Young, CJ (reprint author), SANDIA NATL LABS,DEPT 6116,MS0750,ALBUQUERQUE,NM 87185, USA. RI Aster, Richard/E-5067-2013 OI Aster, Richard/0000-0002-0821-4906 NR 19 TC 30 Z9 32 U1 0 U2 1 PU SEISMOLOGICAL SOC AMER PI EL CERRITO PA PLAZA PROFESSIONAL BLDG, SUITE 201, EL CERRITO, CA 94530 SN 0037-1106 J9 B SEISMOL SOC AM JI Bull. Seismol. Soc. Amer. PD OCT PY 1996 VL 86 IS 5 BP 1516 EP 1528 PG 13 WC Geochemistry & Geophysics SC Geochemistry & Geophysics GA VP989 UT WOS:A1996VP98900024 ER PT J AU Pauley, EF Nodvin, SC Nicholas, NS Rose, AK Coffey, TB AF Pauley, EF Nodvin, SC Nicholas, NS Rose, AK Coffey, TB TI Vegetation, biomass, and nitrogen pools in a spruce-fir forest of the Great Smoky Mountains National Park SO BULLETIN OF THE TORREY BOTANICAL CLUB LA English DT Article DE Abies fraseri; Betula alleghaniensis; biomass; Fraser fir; Great Smoky Mountains; nitrogen; Picea rubens; red spruce; spruce-fir; vegetation ID RED SPRUCE; FRASER FIR; NEW-HAMPSHIRE; REGENERATION; POPULATION; MORTALITY; BOLES AB Unlike most forests, Picea rubens-Abies fraseri forests of the Great Smoky Mountains appear to be saturated with nitrogen (N). However, studies of N cycling in these forests have been carried out only in a few small plots. To expand these data to a landscape scale, studies of N dynamics were initiated in 1991 in an unlogged 17.4 ha watershed. An initial phase of these studies, presented here, was the estimation of overstory species composition, biomass, and standing N pools, and their spatial distributions, in that watershed. Picea comprised most live basal area and biomass and showed no obviously unusual mortality or health symptoms. Abies, although formerly abundant, was a minor overstory component, consisting mostly of small individuals at the highest elevations. Most Abies have been killed by an exotic insect pest, Adelges piceae. Biomass of Betula alleghaniensis was high on low-elevation east-facing slopes near streams. Picea contained 71% of the live overstory N, while Abies contained less than 2%. Although Picea foliage comprised only 6% of live biomass, 37% of the total N content was in Picea needles. Overall, some species distributions reflect well-known landscape patterns (e.g., increasing Abies importance with elevation); distributions of other species (e.g., Picea and Betula) reflect smaller-scale topographic and possibly disturbance-oriented patterns. The watershed is large enough to encompass vegetation patterns at several spatial scales, all of which will influence N storage and dynamics. C1 UNIV TENNESSEE,DEPT ECOL & EVOLUT,KNOXVILLE,TN 37996. UNIV TENNESSEE,NATL BIOL SERV,KNOXVILLE,TN 37996. TENNESSEE VALLEY AUTHOR,NORRIS,TN 37828. UNIV GEORGIA,GEORGIA EXPT STN,GRIFFIN,GA 30223. RP Pauley, EF (reprint author), SAVANNAH RIVER ECOL LAB,DRAWER E,AIKEN,SC 29802, USA. NR 49 TC 11 Z9 11 U1 0 U2 4 PU TORREY BOTANICAL SOCIETY PI LAWRENCE PA 810 EAST 10TH ST, LAWRENCE, KS 66044 SN 0040-9618 J9 B TORREY BOT CLUB JI Bull. Torrey Bot. Club PD OCT-DEC PY 1996 VL 123 IS 4 BP 318 EP 329 DI 10.2307/2996781 PG 12 WC Plant Sciences SC Plant Sciences GA WC521 UT WOS:A1996WC52100009 ER PT J AU Soejarto, AD Coulston, GW Schrader, GL AF Soejarto, AD Coulston, GW Schrader, GL TI In situ laser Raman spectroscopy during sequential oxidizing and reducing conditions for a vanadium-phosphorous-oxide catalyst SO CANADIAN JOURNAL OF CHEMICAL ENGINEERING LA English DT Article DE in situ Raman spectroscopy; selective oxidation ID P-O CATALYSTS; MALEIC-ANHYDRIDE; NORMAL-BUTANE; OXIDATION AB A VPO catalyst prepared in an organic medium has been studied by in situ laser Raman spectroscopy for n-butane oxidation to maleic anhydride. Data could be obtained at low laser power and brief collection times. Raman characterization during continuous flow (steady-state) studies revealed that (VO)(2)P2O7 was present. Sequential oxidizing (10% O-2 in N-2) and reducing (2% n-butane in N-2) conditions were explored at 350 degrees 0 and 400 degrees 0. These cycling (unsteady-state) operations revealed that formation of V(5(+)) phases was enhanced during oxidizing conditions. The intensity of Raman bands due to (YO)(2)P2O7 increased during reducing conditions. C1 IOWA STATE UNIV SCI & TECHNOL, DEPT CHEM ENGN, USDOE, AMES, IA 50011 USA. IOWA STATE UNIV SCI & TECHNOL, AMES LAB, USDOE, AMES, IA 50011 USA. DUPONT CENT RES & DEV, EXPT STN, WILMINGTON, DE 19880 USA. NR 16 TC 5 Z9 5 U1 0 U2 0 PU WILEY-BLACKWELL PI MALDEN PA COMMERCE PLACE, 350 MAIN ST, MALDEN 02148, MA USA SN 0008-4034 J9 CAN J CHEM ENG JI Can. J. Chem. Eng. PD OCT PY 1996 VL 74 IS 5 BP 594 EP 599 PG 6 WC Engineering, Chemical SC Engineering GA VT967 UT WOS:A1996VT96700005 ER PT J AU Adams, SM Ham, KD Greeley, MS LeHew, RF Hinton, DE Saylor, CF AF Adams, SM Ham, KD Greeley, MS LeHew, RF Hinton, DE Saylor, CF TI Downstream gradients in bioindicator responses: Point source contaminant effects on fish health SO CANADIAN JOURNAL OF FISHERIES AND AQUATIC SCIENCES LA English DT Article ID PULP-MILL EFFLUENTS; TROUT SALMO-GAIRDNERI; CATOSTOMUS-COMMERSONI POPULATION; BALTIC COASTAL FISH; ST-MAURICE RIVER; STEROID-LEVELS; BLEACHED PULP; PHYSIOLOGICAL DISTURBANCES; FUNDULUS-HETEROCLITUS; MFO ACTIVITY AB To investigate potential causal relationships between contaminant exposure and biological responses in fish, a suite of bioindicators ranging from the biochemical to the community-level were measured in fish populations and communities downstream from a bleached kraft mill effluent discharge. Downstream gradients in responses were evident in elevated hepatic mixed-function oxygenase activity, several measures of condition and bioenergetic status, growth, the health assessment index, and several fish community-level parameters. A multivariate discriminant analysis procedure, which included many of the individual bioindicators, also demonstrated a gradient in integrated health status of a sentinel fish species in the contaminated river. These downstream response gradients were probably influenced to a greater degree by contaminant discharges than by natural or anthropogenic nutrient sources downstream. Establishing causal relationships between a specific contaminant source and responses in sentinel aquatic organisms becomes relatively more straightforward when downstream gradients in biological responses are observed at multiple levels of biological organization. C1 UNIV CALIF DAVIS, DEPT ANAT PHYS & CELL BIOL, DAVIS, CA 95616 USA. TENNESSEE VALLEY AUTHOR, AQUAT BIOL LAB, NORRIS, TN 37828 USA. RP Adams, SM (reprint author), OAK RIDGE NATL LAB, DIV ENVIRONM SCI, POB 2008, OAK RIDGE, TN 37831 USA. RI Greeley, Mark/D-2330-2016 OI Greeley, Mark/0000-0002-6088-5942 NR 81 TC 59 Z9 64 U1 2 U2 10 PU CANADIAN SCIENCE PUBLISHING, NRC RESEARCH PRESS PI OTTAWA PA 1200 MONTREAL ROAD, BUILDING M-55, OTTAWA, ON K1A 0R6, CANADA SN 0706-652X EI 1205-7533 J9 CAN J FISH AQUAT SCI JI Can. J. Fish. Aquat. Sci. PD OCT PY 1996 VL 53 IS 10 BP 2177 EP 2187 DI 10.1139/cjfas-53-10-2177 PG 11 WC Fisheries; Marine & Freshwater Biology SC Fisheries; Marine & Freshwater Biology GA WE260 UT WOS:A1996WE26000003 ER PT J AU Groat, LA Hawthorne, FC Lager, GA Schultz, AJ Ercit, TS AF Groat, LA Hawthorne, FC Lager, GA Schultz, AJ Ercit, TS TI X-ray and neutron crystal-structure refinements of a boron-bearing vesuvianite SO CANADIAN MINERALOGIST LA English DT Article DE vesuvianite; crystal-structure refinement; neutron diffraction; boron; site populations ID CHEMISTRY; SYMMETRY AB The crystal structure of a sample of B-bearing vesuvianite, Ca-19(Al6.20Fe1.463+Mg3.65Fe1.592+Ti0.16Mn0.07) (Si17.57Al0.43)B2.73O68([OH]2.94F0.65O6.41), a 15.734(1), c 11.719(1) Angstrom, V 2902.2(5) Angstrom(3), P4/nnc, has been refined to an R index of 3.8% based on 1709 observed reflections measured at 298 K with MoK alpha X-radiation, and to an R(F-2) index of 9.4% based on 7482 observed reflections measured at 15 K by TOF (time-of-flight) neutron diffraction, The results of thr two refinements confirm the findings of Great er al. (1992, 1994a, b) on the mechanisms of incorporation of B into the vesuvianite structure. Furthermore, the neutron refinement allowed location of the H, which occurs only at the H(1) position in the crystal examined here. The absence of H at the H(2) channel position, together with the refined scattering at the T(2) site and local bond-valence considerations at the O(10) anion, showed that T(2) is completely occupied by B. The refined site-populations of the O(10) and O(12) sites are compatible only with 0.15 B-[3] and 0.85 B-[3] at the T(2) site. Other crystals of B-bearing vesuvianite also contain B-[3] at T(2) (Groat er al. 1994b). The incorporation of B at T(2) in different coordination environments provides a flexible mechanism that can act in conjunction with other substitutions elsewhere in the structure to satisfy requirements of long-range electroneutrality. C1 UNIV MANITOBA,DEPT GEOL SCI,WINNIPEG,MB R3T 2N2,CANADA. UNIV LOUISVILLE,DEPT GEOG & GEOSCI,LOUISVILLE,KY 40292. ARGONNE NATL LAB,DIV INTENSE PULSED NEUTRON SOURCE,ARGONNE,IL 60439. CANADIAN MUSEUM NAT,DIV MINERAL SCI,OTTAWA,ON K1P 6P4,CANADA. RP Groat, LA (reprint author), UNIV BRITISH COLUMBIA,DEPT GEOL SCI,VANCOUVER,BC V6T 1Z4,CANADA. RI Hawthorne, Frank/F-6864-2011 OI Hawthorne, Frank/0000-0001-6405-9931 NR 18 TC 23 Z9 24 U1 0 U2 0 PU MINERALOGICAL ASSOC CANADA PI NEPEAN PA CITYVIEW 78087, NEPEAN ON K2G 5W2, CANADA SN 0008-4476 J9 CAN MINERAL JI Can. Mineral. PD OCT PY 1996 VL 34 BP 1059 EP 1070 PN 5 PG 12 WC Mineralogy SC Mineralogy GA VV070 UT WOS:A1996VV07000016 ER PT J AU Bigbee, WL Grant, SG Langlois, RG Jensen, RH Anttila, A Pfaffli, P Pekari, K Norppa, H AF Bigbee, WL Grant, SG Langlois, RG Jensen, RH Anttila, A Pfaffli, P Pekari, K Norppa, H TI Glycophorin a somatic cell mutation frequencies in Finnish reinforced plastics workers exposed to styrene SO CANCER EPIDEMIOLOGY BIOMARKERS & PREVENTION LA English DT Article ID SISTER-CHROMATID EXCHANGES; RESISTANT MUTANT FREQUENCY; CULTURED HUMAN-LYMPHOCYTES; O-6-GUANINE DNA-ADDUCTS; ATOMIC-BOMB SURVIVORS; SINGLE-STRAND BREAKS; A LOCUS; BLOOD-LYMPHOCYTES; CHROMOSOME-ABERRATIONS; OCCUPATIONAL EXPOSURE AB We have used the glycophorin A (GPA) in vivo somatic cell mutation assay to assess the genotoxic potential of styrene exposure in 47 reinforced plastics workers occupationally exposed to styrene and 47 unexposed controls matched for age, gender, and active smoking status. GPA variant erythrocyte frequencies (V-f), reflecting GPA allele loss (O/N) and allele loss and duplication (N/N) somatic mutations arising lit vivo in the erythroid progenitor cells of individuals of GPA M/N heterozygous genotype, were flow cytometrically determined in peripheral blood samples from these subjects, Measurements of styrene exposure of the workers at the time of blood sampling showed a mean 8-h time-weighted average (TWA(8-h)) styrene concentration of 155 mg/m(3) (37 ppm) in the breathing zone, Mean urinary concentrations of the styrene metabolites mandelic acid (MA) and mandelic acid plus phenyl glyoxylic acid (MA+PGA) were 4.4 mmol/liter (after workshift) and 2.1 mmol/liter (next morning), respectively, Multivariate analysis of covariance on log-transformed GPA V-f data with models allowing adjustment for age, gender, smoking status, and styrene exposure showed that N/N V-f were nearly significantly increased among an of the exposed workers (adjusted geometric mean, 6.3 per million versus 5.0 in the controls; P = 0.058) and were statistically significantly elevated (adjusted geometric mean, 6.8 versus 5.0 in the controls; P = 0.036) among workers classified into a high-exposure group according to personal TWA(8-h) concentration of styrene in the breathing zone of greater than or equal to 85 mg/m(3) (20 ppm; Finnish threshold limit value), Women in this high exposure group showed especially elevated N/N V-f (adjusted geometric mean 8.5 versus 5.3 in control women; P = 0.020); this elevation was also significant if urinary MA+PGA of greater than or equal to 1.2 mmol/liter was used as the basis of classification (adjusted geometric mean, 8.3; P = 0.030), The occupational exposure could not be shown to influence O/N V-f. Cigarette smoking was associated with significantly elevated GPA V-f among active smokers (P = 0.042 for O/N and P = 0.020 for N/N) and among active and ex-smokers combined (P = 0.014 for N/N), Its influence on O/N V-f was especially clear among active smokers in the control group (P = 0.005), An effect of smoking, nearly statistically significant, was also observed for the O/N V-f of control ex-smokers (P = 0.055) and of all active and ex-smokers combined (P = 0.050), Thus, the two characterized chemical exposures experienced by this group of workers and controls appear to produce differential effects on the two independent classes of GPA variants enumerated in the assay, This result suggests that the genotoxicity of these agents is mediated, at least in part, by different genetic mechanisms, Styrene exposure is associated with a specific increase in GPA N/N V-f; these allele loss and duplication variants reflect predominantly somatic recombination mechanisms in erythroid progenitor cells, Tobacco smoke exposure in active and ex-smokers is also associated not only with an increase in N/N V-f but also with an increase in O/N V-f, reflecting the induction of GPA gene-inactivating mutations, including point mutations and deletions, This finding is consistent with a broad mechanistic spectrum of tobacco smoke genotoxicity associated with this complex mixture of chemical mutagens, Finally, there was no detectable effect of age on O/N V-f; however, a highly significant (P = 0. 0002) increase in N/N V-f with age, even after adjustment for other variables, was observed. C1 UNIV PITTSBURGH, INST CANC, MOL CARCINOGENESIS PROGRAM, PITTSBURGH, PA 15238 USA. LAWRENCE LIVERMORE NATL LAB, BIOL & BIOTECHNOL RES PROGRAM, LIVERMORE, CA 94551 USA. UNIV CALIF SAN FRANCISCO, SCH MED, DEPT LAB MED, SAN FRANCISCO, CA 94103 USA. INST OCCUPAT HLTH, DEPT IND HYG & TOXICOL, HELSINKI, FINLAND. RP Bigbee, WL (reprint author), UNIV PITTSBURGH, GRAD SCH PUBL HLTH, CANC INST, DEPT ENVIRONM & OCCUPAT HLTH, PITTSBURGH, PA 15238 USA. RI Grant, Stephen/D-6984-2014 OI Grant, Stephen/0000-0002-9236-0913 NR 64 TC 27 Z9 27 U1 0 U2 0 PU AMER ASSOC CANCER RESEARCH PI PHILADELPHIA PA 615 CHESTNUT ST, 17TH FLOOR, PHILADELPHIA, PA 19106-4404 USA SN 1055-9965 J9 CANCER EPIDEM BIOMAR JI Cancer Epidemiol. Biomarkers Prev. PD OCT PY 1996 VL 5 IS 10 BP 801 EP 810 PG 10 WC Oncology; Public, Environmental & Occupational Health SC Oncology; Public, Environmental & Occupational Health GA VM565 UT WOS:A1996VM56500006 PM 8896891 ER PT J AU Dees, C Travis, C AF Dees, C Travis, C TI Phenotypic and genotypic analysis of rat liver epithelial cells infected with retroviral shuttle vectors SO CANCER LETTERS LA English DT Article DE stem cells; ras; p53; myc ID P53 GENE; TRANSFORMATION; ONCOGENES; LINEAGE; INVITRO AB Rat liver epithelial cells (RLE) are suspected to be pluripotent hepatic stem cells that give rise to a diverse variety of liver tumors. The molecular events responsible for transformation of these cells and the diversity of the tumor phenotypes remains to be fully elucidated. We examined the genotype and phenotype of RLE cells infected with retroviral shuttle vectors carrying a neomycin resistance (neo(1)) Ha-ras or a lacZ gene. WBneoIII, WBrasIII and WBlacZ cell lines were examined for evidence of a transformed phenotype by comparing their behavior with the parental strain (WE-344) and with WBneo-C-II and WBrasII cells. Confluent cultures of WBneo-C-II and WBrasII cells were found to contain significantly higher numbers of total cells than the other cell lines, The growth rate of WBneo-C-II and WBrasII cells were faster than that of the parental cell line. Addition of epidermal growth factor (EGF) to the medium was found to stimulate the growth rate of WBneo-C-II cells and to induce anchorage independent growth (AIG). No cell line produced tumors in nude mice (nu/nu) except WBrasII cells. Radioimmunoprecipitation studies and sequencing of the p53 exons 5-8 indicate WBneo-C-II, and WBrasII cells produce a mutant p53. Northern blot analysis showed an increased expression of c-myc mRNA in WBneo-C-II and WBrasII cells. These results demonstrate that alterations in critical growth and differentiation controlling genes have occurred in WBrasII cells which may, independent of or in conjunction with ras insertion, cause the transformed phenotype. RP Dees, C (reprint author), OAK RIDGE NATL LAB,HLTH SCI RES DIV,MOL TOXICOL GRP,RISK ANAL SECT,BLDG 4500S-MS-6109,POB 2008,OAK RIDGE,TN 37831, USA. NR 25 TC 2 Z9 2 U1 0 U2 3 PU ELSEVIER SCI IRELAND LTD PI CLARE PA CUSTOMER RELATIONS MANAGER, BAY 15, SHANNON INDUSTRIAL ESTATE CO, CLARE, IRELAND SN 0304-3835 J9 CANCER LETT JI Cancer Lett. PD OCT 1 PY 1996 VL 107 IS 1 BP 19 EP 28 DI 10.1016/0304-3835(96)04338-8 PG 10 WC Oncology SC Oncology GA VP941 UT WOS:A1996VP94100004 PM 8913262 ER PT J AU Smith, DR Chandra, S Coderre, JA Morrison, GH AF Smith, DR Chandra, S Coderre, JA Morrison, GH TI Ion microscopy imaging of B-10 from p-boronophenylalanine in a brain tumor model for boron neutron capture therapy SO CANCER RESEARCH LA English DT Article ID CULTURED-CELLS; COMPLEX; CANCER AB Boron neutron capture therapy (BNCT), a binary treatment modality that can potentially irradiate tumor tissue within cellular dimensions, is critically dependent on the preferential delivery of B-10 to individual neoplastic cells, In this study, ion microscopy was used to quantitatively evaluate the selectivity of p-boronophenylalanine-fructose (BPA-F) in the rat 9L gliosarcoma brain tumor model. With a spatial resolution of similar to 0.5 mu m, ion microscopy Images show that BPA-F delivers 3.5 times more boron to the main tumor mass [99 +/- 36 mu g/g tissue (mean +/- SD)] than to the contiguous normal brain (27 +/- 12 mu g/g tissue). A similar, but lower, accumulation was observed away from the main tumor mass in small clusters of neoplastic cells (47 +/- 15 mu g/g tissue) invading the surrounding brain (16 +/- 8 mu g/g tissue), These findings establish for the first time the selectivity of BPA-F to the neoplastic cells invading the normal brain and provide a much-needed baseline measurement of the distribution of a clinically approved BNCT drug, Given the propensity for malignant brain tumors to infiltrate the surrounding normal brain, these observations have particular significance for clinical trials of BNCT for human glioblastoma multiforme using the drug BPA-F. C1 CORNELL UNIV,BAKER LAB,DEPT CHEM,ITHACA,NY 14853. BROOKHAVEN NATL LAB,DEPT MED,UPTON,NY 11973. NR 26 TC 72 Z9 72 U1 1 U2 3 PU AMER ASSOC CANCER RESEARCH PI PHILADELPHIA PA PUBLIC LEDGER BLDG, SUITE 816, 150 S. INDEPENDENCE MALL W., PHILADELPHIA, PA 19106 SN 0008-5472 J9 CANCER RES JI Cancer Res. PD OCT 1 PY 1996 VL 56 IS 19 BP 4302 EP 4306 PG 5 WC Oncology SC Oncology GA VK307 UT WOS:A1996VK30700003 PM 8813111 ER PT J AU Zhang, XB Felton, JS Tucker, JD Urlando, C Heddle, JA AF Zhang, XB Felton, JS Tucker, JD Urlando, C Heddle, JA TI Intestinal mutagenicity of two carcinogenic food mutagens in transgenic mice: 2-amino-1-methyl-6-phenylimidazo[4,5-b]pyridine and amino(alpha)carboline SO CARCINOGENESIS LA English DT Article ID HETEROCYCLIC AMINES; IN-VIVO; SOMATIC MUTATION; COOKED FOOD; RAT-LIVER; MOUSE; GENE; PHIP; INDUCTION; INVIVO AB The heterocyclic amines produced during the cooking of meat, including amino(alpha)carboline (A alpha C) and 2-amino-1-methyl-6-phenylimidazo[4,5-b]pyridine (PhIP), are potent bacterial mutagens and are carcinogenic in rodents. PhIP is mutagenic in the small intestine, but its mutagenicity in the colon, where most human intestinal cancers arise, has not been reported, nor has the mutagenicity of A alpha C. In this study, A alpha C (800 p.p.m.) was fed for 30 and 45 days and PhIP (100 and 400 p.p.m.) was fed for 30, 60 and 90 days to groups of F-1 (C57BL/6xSWR) mice hemizygous for multiple tandem copies of a lad transgene (the Big Blue(TM) mouse) and heterozygous at the endogenous Dlb-1 locus, The mutant frequencies were assayed at Dlb-1 and at lad in the small intestine and at lacI in the colon, PhIP induced mutations at both loci in the small intestine and induced slightly fewer mutations in the colon, The accumulation of mutations at both loci appears to be linear with both PhIP concentration and duration of exposure and, thus, with dose(concentration x duration). The linear increase with time is in agreement with predictions about the effectiveness of chronic treatment protocols for tests of in vivo mutagenicity, Unlike PhIP, A alpha C induced mutations specifically in the colon and not in the small intestine, thereby showing a dramatic tissue specificity, The rate (mutations/p.p.m. day) was similar to PhIP. C1 YORK UNIV,DEPT BIOL,TORONTO,ON M3J 1P3,CANADA. LAWRENCE LIVERMORE NATL LAB,PROGRAM MOL BIOL & BIOTECHNOL,LIVERMORE,CA 94551. FU PHS HHS [55861] NR 48 TC 60 Z9 60 U1 0 U2 4 PU OXFORD UNIV PRESS UNITED KINGDOM PI OXFORD PA WALTON ST JOURNALS DEPT, OXFORD, ENGLAND OX2 6DP SN 0143-3334 J9 CARCINOGENESIS JI Carcinogenesis PD OCT PY 1996 VL 17 IS 10 BP 2259 EP 2265 DI 10.1093/carcin/17.10.2259 PG 7 WC Oncology SC Oncology GA VM805 UT WOS:A1996VM80500024 PM 8895498 ER PT J AU Fuller, TA Flynn, TJ Daw, CS AF Fuller, TA Flynn, TJ Daw, CS TI Analysis of dynamic boiler measurements: A practical approach SO CHEMICAL ENGINEERING JOURNAL LA English DT Article DE dynamic boiler measurements; emissions regulations; economic pressure ID FLUIDIZED-BED; TIME-SERIES; SCALING RELATIONSHIPS; STRANGE ATTRACTORS; ENTROPY; CHAOS AB Driven by economic pressures and government emissions regulations, the electric power industry is moving toward tighter control of boilers to improve plant efficiency and reduce emissions. Tighter control depends on better boiler diagnostic tools, especially for discriminating dynamic patterns and correlating those patterns with overall performance. Our research indicates that improved discrimination of dynamic patterns in boilers can be achieved by combining traditional data analysis techniques and chaotic time series analysis. Suggested analysis tools and data acquisition procedures are described, along with example results for measurements from a pressurized fluidized bed and a low-NOx pulverized coal boiler. C1 OAK RIDGE NATL LAB,OAK RIDGE,TN 37831. RP Fuller, TA (reprint author), BABCOCK & WILCOX CO,DIV RES & DEV,1562 BEESON ST,ALLIANCE,OH 44601, USA. NR 44 TC 8 Z9 8 U1 0 U2 2 PU ELSEVIER SCIENCE SA LAUSANNE PI LAUSANNE PA PO BOX 564, 1001 LAUSANNE, SWITZERLAND SN 0923-0467 J9 CHEM ENG J JI Chem. Eng. J. PD OCT PY 1996 VL 64 IS 1 BP 179 EP 189 DI 10.1016/S0923-0467(96)03130-2 PG 11 WC Engineering, Environmental; Engineering, Chemical SC Engineering GA WA412 UT WOS:A1996WA41200018 ER PT J AU Nguyen, K Daw, CS Chakka, P Cheng, M Bruns, DD Finney, CEA Kennel, MB AF Nguyen, K Daw, CS Chakka, P Cheng, M Bruns, DD Finney, CEA Kennel, MB TI Spatio-temporal dynamics in a train of rising bubbles SO CHEMICAL ENGINEERING JOURNAL LA English DT Article DE bubbling; chaos; spatio-temporal systems ID SURROGATE DATA; TIME-SERIES; FAUCET; CHAOS AB It has been suggested that rising bubbles in dense fluids resemble an inverted dripping faucet and that they undergo analogous period-doubling bifurcations to chaos. We present experimental results that demonstrate that this analogy is weak because the dominant source of instability in the bubble train is inherently different - mutual interactions between spatially separated bubbles as opposed to nozzle dynamics. Unlike the dripping faucet, the initial instability in a bubble train develops at a location far from the injection nozzle and progresses toward the nozzle with increasing gas flow. From qualitative and rigorous quantitative observations, we conclude that rising-bubble dynamics are best described as 'small-box spatio-temporal chaos' with a flow instability. Such dynamics can superficially appear to be simple temporal chaos when considering spatially localized measurements. We show similarity between our experimental results and a bubble-interaction model that accounts for drag and coalescence effects without considering any nozzle dynamics. C1 OAK RIDGE NATL LAB,OAK RIDGE,TN 37831. RP Nguyen, K (reprint author), UNIV TENNESSEE,KNOXVILLE,TN 37996, USA. NR 26 TC 28 Z9 28 U1 0 U2 3 PU ELSEVIER SCIENCE SA LAUSANNE PI LAUSANNE PA PO BOX 564, 1001 LAUSANNE, SWITZERLAND SN 0923-0467 J9 CHEM ENG J JI Chem. Eng. J. PD OCT PY 1996 VL 64 IS 1 BP 191 EP 197 DI 10.1016/S0923-0467(96)03126-0 PG 7 WC Engineering, Environmental; Engineering, Chemical SC Engineering GA WA412 UT WOS:A1996WA41200019 ER PT J AU Savikhin, S Struve, WS AF Savikhin, S Struve, WS TI Temperature dependence of electronic energy transfers within B850 antennae of the NF57 mutant of the purple bacterium Rhodobacter sphaeroides SO CHEMICAL PHYSICS LA English DT Article ID LIGHT-HARVESTING COMPLEX; PUMP-PROBE SPECTROSCOPY; PROSTHECOCHLORIS-AESTUARII; FEMTOSECOND SPECTROSCOPY; CHLOROBIUM-TEPIDUM; TRANSFER DYNAMICS; OPTICAL-SPECTRA; BACTERIOCHLOROPHYLL; PROTEIN; COHERENCE AB Two-color absorption difference experiments were performed using numerous pump-probe wavelength combinations within the B850 absorption band of NF57 (LH1-deficient) mutant chromatophores from the purple bacterium Rhodobacter sphaeroides. Bacteriochlorophyll a photobleaching/stimulated emission rise features are observed at 870 nm for pump wavelengths between 830 and 860 nm. They typically exhibit 80-100 fs kinetics at room temperature, and 250-300 fs kinetics at 19 K. For other wavelength combinations, the time evolution in the B850 absorption difference profiles is somewhat reminiscent of BChl a spectral equilibration in FMO trimers, antenna complexes with well-defined structure that are known to exhibit diagonal energy heterogeneity. Our results suggest the presence of diagonal disorder within the B850 band of individual LH2 antennae, possibly due to distortions from C-n symmetry. The temperature dependence of B850 spectral equilibration is considerably less marked than that of spectral equilibration in FMO trimers. C1 IOWA STATE UNIV SCI & TECHNOL,US DOE,AMES LAB,AMES,IA 50011. IOWA STATE UNIV SCI & TECHNOL,DEPT CHEM,AMES,IA 50011. NR 37 TC 20 Z9 21 U1 1 U2 3 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0301-0104 J9 CHEM PHYS JI Chem. Phys. PD OCT 1 PY 1996 VL 210 IS 1-2 BP 91 EP 100 DI 10.1016/0301-0104(96)00122-X PG 10 WC Chemistry, Physical; Physics, Atomic, Molecular & Chemical SC Chemistry; Physics GA VK647 UT WOS:A1996VK64700010 ER PT J AU Glutsch, S AF Glutsch, S TI Theory of the optical properties of excitons in a homogeneous magnetic field SO CHEMICAL PHYSICS LA English DT Article ID FANO RESONANCES; MAGNETOEXCITON; SEMICONDUCTORS AB We derive the semiconductor Bloch equations for magnetoexcitons in real space. By means of the Laguerre-Fourier transform, an equivalent formulation can be given which uses Landau orbitals and plane waves as a basis set. The linear optical absorption is calculated using the real-space formulation. A transition is performed from a three-dimensional (zero magnetic field) to a one-dimensional (high magnetic field) semiconductor. A gap equation for a dense exciton gas is deduced, which contradicts previous results. RP Glutsch, S (reprint author), LAWRENCE BERKELEY NATL LAB,DIV MAT SCI,BERKELEY,CA 94720, USA. NR 19 TC 1 Z9 1 U1 1 U2 3 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0301-0104 J9 CHEM PHYS JI Chem. Phys. PD OCT 1 PY 1996 VL 210 IS 1-2 BP 109 EP 116 DI 10.1016/0301-0104(96)00150-4 PG 8 WC Chemistry, Physical; Physics, Atomic, Molecular & Chemical SC Chemistry; Physics GA VK647 UT WOS:A1996VK64700012 ER PT J AU Chemla, DS Bigot, JY AF Chemla, DS Bigot, JY TI Ultrafast phase and amplitude dynamics of coherent transients in semiconductor quantum wells SO CHEMICAL PHYSICS LA English DT Article ID ABSORPTION-EDGE SINGULARITIES; NONEQUILIBRIUM FERMI SEA; FEMTOSECOND PHOTON-ECHOES; FREE-INDUCTION DECAY; TO-BAND TRANSITIONS; OPTICAL EXPERIMENTS; LIGHT-PULSES; GAAS; BIEXCITONS; EXCITONS AB We present investigations of the temporal evolution of phase and amplitude of coherent emission of GaAs/GaAlAs quantum well structures, excited by ultrashort laser pulses. We find that the coherent light emitted by excitons or by electron-hole pairs exhibits a complex phase behavior, which depends critically on the intensity and the central frequency of the exciting pulses. We observe nonlinear shifts of the instantaneous frequency within one ultrashort pulsed emission. We also discuss the theoretical interpretation the experiments. Although it is clear that non-local Coulomb correlation and non-Markovian dephasing processes are responsible for the observations, quantitative theories are not available presently. Therefore our experiments, point the need for theoretical refinements of nonlinear optical processes in semiconductors. C1 LAWRENCE BERKELEY NATL LAB,DIV MAT SCI,BERKELEY,CA 94720. INST PHYS & CHIM MAT STRASBOURG,OPT NONLINEAIRE & OPTOELECT GRP,F-67084 STRASBOURG,FRANCE. RP Chemla, DS (reprint author), UNIV CALIF BERKELEY,DEPT PHYS,BERKELEY,CA 94720, USA. NR 65 TC 12 Z9 12 U1 2 U2 3 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0301-0104 J9 CHEM PHYS JI Chem. Phys. PD OCT 1 PY 1996 VL 210 IS 1-2 BP 135 EP 154 DI 10.1016/0301-0104(96)00050-X PG 20 WC Chemistry, Physical; Physics, Atomic, Molecular & Chemical SC Chemistry; Physics GA VK647 UT WOS:A1996VK64700014 ER PT J AU Siegner, U BarAd, S Chemla, DS AF Siegner, U BarAd, S Chemla, DS TI Ultrafast coherent spectroscopy of one-dimensional magnetoexcitons in semiconductors SO CHEMICAL PHYSICS LA English DT Article ID HEAVY HOLE EXCITONS; QUANTUM-WELLS; FANO RESONANCES; 2-DIMENSIONAL MAGNETOEXCITONS; CONTINUUM STATES; LIGHT-HOLE; BEATS; GAAS; DYNAMICS; INTERFERENCE AB We investigate the ultrashort coherent dynamics of one-dimensional Fano and Lorentzian magnetoexcitons in GaAs using temporally and spectrally resolved four-wave mixing (FWM), The dephasing time of a Fano resonance is intrinsically limited by the coupling between discrete states and continua which is responsible for Fano interference. In contrast, the coherent emission from Lorentzian magnetoexcitons dephases solely due to quasi-particle scattering, dominated by exciton-exciton scattering at low temperatures. We find a very fast decay of the time-integrated FWM signal from Fano magnetoexciton resonances. This decay is not due to dephasing. The quenching of the FWM signal for non-overlapping excitation pulses is the result of quantum interference. This destructive quantum interference is not observed for purely Lorentzian dynamics. For the simultaneous excitation of Lorentzian and Fano magnetoexciton resonances, destructive quantum interference also quenches the coherent emission from Lorentzian magnetoexcitons due to quantum mechanical coupling between the different resonances. C1 UNIV CALIF BERKELEY,LAWRENCE BERKELEY LAB,DIV MAT SCI,BERKELEY,CA 94720. ETH HONGGERBERG,HPT,INST QUANTUM ELECT,CH-8093 ZURICH,SWITZERLAND. RP Siegner, U (reprint author), UNIV CALIF BERKELEY,DEPT PHYS,BERKELEY,CA 94720, USA. NR 28 TC 4 Z9 4 U1 0 U2 0 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0301-0104 J9 CHEM PHYS JI Chem. Phys. PD OCT 1 PY 1996 VL 210 IS 1-2 BP 155 EP 170 DI 10.1016/0301-0104(96)00076-6 PG 16 WC Chemistry, Physical; Physics, Atomic, Molecular & Chemical SC Chemistry; Physics GA VK647 UT WOS:A1996VK64700015 ER PT J AU Lane, PA Wei, X Vardeny, ZV Poplawski, J Ehrenfreund, E Ibrahim, M Frank, AJ AF Lane, PA Wei, X Vardeny, ZV Poplawski, J Ehrenfreund, E Ibrahim, M Frank, AJ TI Absorption spectroscopy of charged excitations in alpha-sexithiophene: Evidence for charge conjugation symmetry breaking SO CHEMICAL PHYSICS LA English DT Article ID ELECTRICAL CHARACTERISTICS; THIOPHENE OLIGOMERS; CATION; POLYTHIOPHENE; OLIGOTHIOPHENES; POLYACETYLENE; SEXITHIENYL; TRANSISTORS; BIPOLARONS; POLARONS AB We have studied the absorption spectra of charged excitations in sexithiophene thin films induced by doping and photogeneration. Absorption bands at 0.80 and 1.54 eV are attributed to spin-1/2 polarons, whereas a single absorption band at 1.1 eV is due to spinless bipolarons. Charge conjugation symmetry breaking is evident for both polarons and bipolarons. C1 TECHNION ISRAEL INST TECHNOL,INST SOLID STATE,IL-32000 HAIFA,ISRAEL. NAT RENEWABLE ENERGY LAB,GOLDEN,CO 80401. RP Lane, PA (reprint author), UNIV UTAH,DEPT PHYS,SALT LAKE CITY,UT 84112, USA. RI Ehrenfreund, Eitan/B-6680-2008 NR 27 TC 19 Z9 19 U1 0 U2 6 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0301-0104 J9 CHEM PHYS JI Chem. Phys. PD OCT 1 PY 1996 VL 210 IS 1-2 BP 229 EP 234 DI 10.1016/0301-0104(96)00075-4 PG 6 WC Chemistry, Physical; Physics, Atomic, Molecular & Chemical SC Chemistry; Physics GA VK647 UT WOS:A1996VK64700019 ER PT J AU Greenfield, SR Seibert, M Govindjee Wasielewski, MR AF Greenfield, SR Seibert, M Govindjee Wasielewski, MR TI Wavelength and intensity dependent primary photochemistry of isolated Photosystem II reaction centers at 5 degrees C SO CHEMICAL PHYSICS LA English DT Article ID REACTION-CENTER COMPLEX; TRANSIENT ABSORPTION-SPECTROSCOPY; RADICAL PAIR FORMATION; CHARGE SEPARATION RATE; 2 REACTION CENTERS; ENERGY-TRANSFER; EXCITATION-ENERGY; ELECTRON-TRANSFER; PHEOPHYTIN; STATE AB The long wavelength absorption band of the isolated Photosystem II reaction center was directly excited at five wavelengths between 655 and 689 nm to study the effects of excitation wavelength and intensity on both excitation energy transfer and charge separation processes. Subpicosecond transient absorption measurements were made monitoring principally the bleach of the pheophytin a Q(x) band at 544 nm. At all pump wavelengths, the kinetics require three exponentials (1-3, 10-25 and 50-100 ps) to be fit properly. The pump energy was varied by a factor of twenty-five (40-1000 nJ), with no apparent effect on either the rates or the amplitude ratios of the three components, although clear evidence of nonlinear behavior was observed at the higher excitation energies. The dependence of both the rates and amplitude ratios of the three components upon pump wavelength will be discussed in terms of excitation energy transfer occurring on a 30 ps timescale. Selective excitation into the short and long-wavelength sides of the composite Q(y) band give identical transient spectra at 500 ps, indicating near-unity efficiency of excitation energy transfer. At 1 ps, the spectra are quite different, calling into question the extent of ultrafast (similar to 100 fs) excitation energy transfer. The time after the excitation pulse at which the transient crosses Delta A = 0 was found to be a highly sensitive measure of both the excitation energy and the identity of the pigment pool that had been excited. C1 ARGONNE NATL LAB,DIV CHEM,ARGONNE,IL 60439. NATL RENEWABLE ENERGY LAB,BASIC SCI CTR,GOLDEN,CO 80401. UNIV ILLINOIS,DEPT PLANT BIOL,URBANA,IL 61801. NORTHWESTERN UNIV,DEPT CHEM,EVANSTON,IL 60208. NR 46 TC 25 Z9 26 U1 0 U2 1 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0301-0104 J9 CHEM PHYS JI Chem. Phys. PD OCT 1 PY 1996 VL 210 IS 1-2 BP 279 EP 295 DI 10.1016/0301-0104(96)00185-1 PG 17 WC Chemistry, Physical; Physics, Atomic, Molecular & Chemical SC Chemistry; Physics GA VK647 UT WOS:A1996VK64700023 ER PT J AU Devanesan, PD Higginbotham, S Ariese, F Jankowiak, R Suh, M Small, GJ Cavalieri, EL Rogan, EG AF Devanesan, PD Higginbotham, S Ariese, F Jankowiak, R Suh, M Small, GJ Cavalieri, EL Rogan, EG TI Depurinating and stable benzo[a]pyrene-DNA adducts formed in isolated rat liver nuclei SO CHEMICAL RESEARCH IN TOXICOLOGY LA English DT Article ID ONE-ELECTRON OXIDATION; DNA-ADDUCTS; AROMATIC-HYDROCARBONS; METABOLIC-ACTIVATION; MOUSE SKIN; IDENTIFICATION; QUANTITATION; CARCINOGENESIS; MICROSOMES; INVITRO AB Polycyclic aromatic hydrocarbons are bound to DNA by two major pathways, one-electron oxidation and monooxygenation, to form adducts that are stable in DNA under normal conditions of isolation and depurinating adducts that are released from DNA by cleavage of the bond between the purine base and deoxyribose. Isolated rat liver nuclei have been used as an in vitro model for studying covalent binding of aromatic hydrocarbons to DNA, but the depurinating adducts formed by nuclei have not been identified or compared to those formed by the more commonly used rat liver microsomes. To examine the profiles of stable and depurinating adducts, nuclei from the livers of 3-methylcholanthrene-induced male MRC Wistar rats were incubated with [H-3]benzo[a]pyrene (BP) and NADPH. Three depurinating adducts, 8-(BP-6-yl)Gua, 7-(BP-6-yl)Gua, and 7-(BP-6-yl)Ade, were obtained from the nuclei, as seen previously with rat liver microsomes or in mouse skin. The profile of stable adducts analyzed by the P-32-postlabeling method was qualitatively similar to that found in the microsomal activation of BP or in mouse skin treated with BP. Low-temperature fluorescence studies of the nuclear DNA revealed the presence of stable BP adducts originating from syn- and anti-BP diol epoxide. C1 UNIV NEBRASKA,MED CTR,EPPLEY INST RES CANC & ALLIED DIS,OMAHA,NE 68198. IOWA STATE UNIV,DEPT CHEM,AMES,IA 50011. IOWA STATE UNIV,US DOE,AMES LAB,AMES,IA 50011. FU NCI NIH HHS [R01 CA44686, R01 CA25176, P01 CA49210] NR 22 TC 33 Z9 34 U1 0 U2 1 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 SN 0893-228X J9 CHEM RES TOXICOL JI Chem. Res. Toxicol. PD OCT-NOV PY 1996 VL 9 IS 7 BP 1113 EP 1116 DI 10.1021/tx9600513 PG 4 WC Chemistry, Medicinal; Chemistry, Multidisciplinary; Toxicology SC Pharmacology & Pharmacy; Chemistry; Toxicology GA VN272 UT WOS:A1996VN27200007 PM 8902265 ER PT J AU Tan, KM Ko, YH Parise, JB Park, JH Darovsky, A AF Tan, KM Ko, YH Parise, JB Park, JH Darovsky, A TI A novel antimony sulfide templated by dimethylammonium: Its synthesis and structural characterization using synchrotron/imaging plate data SO CHEMISTRY OF MATERIALS LA English DT Article ID CRYSTAL-STRUCTURE; TIN SULFIDE AB Hydrothermal synthesis at 200 degrees C produced a new open antimony sulfide framework, [C2H8N](2)[Sb8S12(S-2)], designated DMA-SbS-SB8. The structure (Cmca, a = 9.9704(7), b = 11.652(2), and c = 25.979(3) Angstrom), determined from data collected on a small single crystal (20 x 30 x 40 mu m in size) utilizing the synchrotron/imaging plate system installed at the X3A1 beamline of the NSLS, consists of [Sb8S12(S-2)](2-) double chains formed from Sb4S72- single chains joined through S-S bridges. The double chains contain 18-membered Sb8S10 rings and are interlocked to form sheets perpendicular to the b axis. Dimethylammonium ions, assumed to be protonated to charge balance the anionic [Sb8S12(S-2)](2-) framework, reside within 18-membered rings. The structural building units of the new open framework are similar to those described previously in other members of the antimony sulfide system. Experiments carried out at different temperatures and reaction times show that DMA-SbS-SB8 is formed from a distinct poorly crystallized phase (designated DMA-SbS-SB8'), which is the dominant phase at 100 degrees C. C1 SUNY STONY BROOK,CHIPR,NSF FUNDED SCI & TECHNOL CTR,STONY BROOK,NY 11794. SUNY STONY BROOK,DEPT EARTH & SPACE SCI,STONY BROOK,NY 11794. SUNY STONY BROOK,DEPT CHEM,STONY BROOK,NY 11794. BROOKHAVEN NATL LAB,NATL SYNCHROTRON LIGHT SOURCE DEPT,SUNY X3A BEAMLINE,UPTON,NY 11973. NR 43 TC 42 Z9 42 U1 0 U2 2 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 SN 0897-4756 J9 CHEM MATER JI Chem. Mat. PD OCT PY 1996 VL 8 IS 10 BP 2510 EP 2515 DI 10.1021/cm9602398 PG 6 WC Chemistry, Physical; Materials Science, Multidisciplinary SC Chemistry; Materials Science GA VN248 UT WOS:A1996VN24800019 ER PT J AU Lowe, X OHogan, S Moore, D Bishop, J Wyrobek, A AF Lowe, X OHogan, S Moore, D Bishop, J Wyrobek, A TI Aneuploid epididymal sperm detected in chromosomally normal and Robertsonian translocation-bearing mice using a new three-chromosome FISH method SO CHROMOSOMA LA English DT Article ID IN-SITU HYBRIDIZATION; EMBRYOS FERTILIZED INVITRO; METACENTRIC CHROMOSOMES; MOUSE; CELLS AB We present a new method to detect epididymal sperm aneuploidy (ESA) in mice using simultaneous fluorescence in situ hybridization (FISH) with DNA probes specific for mouse chromosomes X, Y and 8. The method was applied to Robertsonian (Rb) translocation (8.14) heterozygotes and homozygotes as well as the chromosomally normal B6C3F1. The sex ratios of sperm did not differ from the expected 1:1 and the hybridization efficiencies were similar to 99.7% for over 60 000 sperm analyzed. Mice heterozygous for Rb (8.14) produced about tenfold higher rates of sperm with chromosome 8 hyperhaploidy than did Rb (8.14) homozygotes or chromosomally normal mice, while frequencies of sperm with hyperhaploidies for chromosomes X and Y were unaffected in all three lines of mice. Hyperhaploid frequencies obtained with the ESA method were consistent with those of the previous testicular FISH method and were validated by published data obtained by conventional cytogenetic analyses (meiotic metaphase II and first cleavage). Thus, the mouse three-chromosome ESA assay together with the previously developed aneuploidy assay for human sperm constitute a promising pair of interspecific biomarkers for comparative studies of the genetic and physiologic mechanisms of the induction and persistence of aneuploidy in male germ cells. C1 LAWRENCE LIVERMORE NATL LAB,BIOL & BIOTECHNOL RES PROGRAM,LIVERMORE,CA 94550. NIEHS,RES TRIANGLE PK,NC 27709. FU NIEHS NIH HHS [IAG Y01-ES-10203-00] NR 39 TC 30 Z9 31 U1 0 U2 0 PU SPRINGER VERLAG PI NEW YORK PA 175 FIFTH AVE, NEW YORK, NY 10010 SN 0009-5915 J9 CHROMOSOMA JI Chromosoma PD OCT PY 1996 VL 105 IS 4 BP 204 EP 210 PG 7 WC Biochemistry & Molecular Biology; Genetics & Heredity SC Biochemistry & Molecular Biology; Genetics & Heredity GA VT553 UT WOS:A1996VT55300002 PM 8854879 ER PT J AU Malekani, K Rice, JA Lin, JS AF Malekani, K Rice, JA Lin, JS TI Comparison of techniques for determining the fractal dimensions of clay minerals SO CLAYS AND CLAY MINERALS LA English DT Article DE adsorption; clay; fractal; NMR; small-angle x-ray scattering ID ANGLE X-RAY; HUMIC SUBSTANCES; SURFACE-AREA; ADSORPTION; SCATTERING; SILICA; SEDIMENTS; COLLOIDS AB Small-angle X-ray scattering (SAXS), adsorption and nuclear magnetic resonance (NMR) techniques were used to determine the fractal dimensions (D) of 3 natural reference clays: 1) a kaolinite (KGa-2); 2) a hectorite (SHCa-1), and 3) a Ca-montmorillonite (STx-1). The surfaces of these clays were found to be fractal with D values close to 2.0. This is consistent with the common description of clay mineral surfaces as smooth and planar. Some surface irregularities were observed for hectorite and Ca-montmorillonite as a result of impurities in the materials. The SAXS method generated comparable D values for KGa-2 and STx-1. These results are supported by scanning electron microscopy (SEM). The SAXS and adsorption methods were found to probe the surface irregularities of the clays while the nuclear magnetic resonance (NMR) technique seems to reflect the mass distribution of certain sites in the material. Since the surface nature of clays is responsible for their reactivity in natural systems, SAXS and adsorption techniques would be the methods of choice for their fractal characterization. Due to its wider applicable characterization size-range, the SAXS method appears to be better suited for the determination of the fractal dimensions of clay minerals. C1 OAK RIDGE NATL LAB,DIV SOLID STATE,CTR SMALL ANGLE SCATTERING,OAK RIDGE,TN 37831. RP Malekani, K (reprint author), S DAKOTA STATE UNIV,DEPT CHEM & BIOCHEM,BROOKINGS,SD 57007, USA. NR 32 TC 18 Z9 18 U1 0 U2 10 PU CLAY MINERALS SOCIETY PI BOULDER PA PO BOX 4416, BOULDER, CO 80306 SN 0009-8604 J9 CLAY CLAY MINER JI Clay Clay Min. PD OCT PY 1996 VL 44 IS 5 BP 677 EP 685 DI 10.1346/CCMN.1996.0440511 PG 9 WC Chemistry, Physical; Geosciences, Multidisciplinary; Mineralogy; Soil Science SC Chemistry; Geology; Mineralogy; Agriculture GA VT786 UT WOS:A1996VT78600011 ER PT J AU Post, WM Pastor, J AF Post, WM Pastor, J TI Linkages - An individual-based forest ecosystem model SO CLIMATIC CHANGE LA English DT Article; Proceedings Paper CT International-Geosphere-Biosphere-Program Workshop on the Application of Forest-Stand-Models-to-Global-Change-Issues CY 1994 CL APELDOORN, NETHERLANDS SP Int Geosphere Biosphere Program ID CO2-INDUCED CLIMATE CHANGE; NITROGEN; LITTER AB Carbon storage and flow through forest ecosystems are major components of the global carbon cycle. The cycle of carbon is intimately coupled with the cycle of nitrogen and the flow of water through forests. The supply of water for tree growth is determined by climate and soil physical properties. The rate at which nitrogen mineralization occurs depends on climate and the type of carbon compounds with which the nitrogen is associated. Species composition, which is also affected by climate, can greatly influence the composition of carbon compounds and subsequently nitrogen availability. Climate change can therefore have a direct effect on forest ecosystem production and carbon storage through temperature and water limitations, and an indirect effect through the nitrogen cycle by affecting species composition. Model simulations of these interactions show that climate change initiates a complex set of direct and indirect responses that are sensitive to the exact nature of the project climate changes. We show results using four different climate-change projections for a location in northeastern Minnesota. Modeled forest responses to each of these climate projections is different indicating that uncertainties in the climate projections may be amplified further as a result of shifts in balance between positive and negative ecosystem feedbacks. C1 UNIV MINNESOTA,NAT RESOURCES RES INST,DULUTH,MN 55811. RP Post, WM (reprint author), OAK RIDGE NATL LAB,DIV ENVIRONM SCI,OAK RIDGE,TN 37831, USA. RI Post, Wilfred/B-8959-2012; Pastor, John/F-6241-2011 NR 14 TC 62 Z9 67 U1 0 U2 14 PU KLUWER ACADEMIC PUBL PI DORDRECHT PA SPUIBOULEVARD 50, PO BOX 17, 3300 AA DORDRECHT, NETHERLANDS SN 0165-0009 J9 CLIMATIC CHANGE JI Clim. Change PD OCT PY 1996 VL 34 IS 2 BP 253 EP 261 PG 9 WC Environmental Sciences; Meteorology & Atmospheric Sciences SC Environmental Sciences & Ecology; Meteorology & Atmospheric Sciences GA VR565 UT WOS:A1996VR56500012 ER PT J AU Schloesser, R Simkowitz, P Bartlett, EJ Wolkin, A Smith, GS Dewey, SL Brodie, JD AF Schloesser, R Simkowitz, P Bartlett, EJ Wolkin, A Smith, GS Dewey, SL Brodie, JD TI The study of neurotransmitter interactions using positron emission tomography and functional coupling SO CLINICAL NEUROPHARMACOLOGY LA English DT Review DE brain imaging; positron emission tomography; schizophrenia; neurotransmitter; interaction; neuroleptic ID D2-DOPAMINE RECEPTOR OCCUPANCY; GLUCOSE METABOLIC MEASUREMENTS; PLASMA HOMOVANILLIC-ACID; C-11 N-METHYLSPIPERONE; LIVING HUMAN-BRAIN; SCHIZOPHRENIC-PATIENTS; BENZODIAZEPINE RECEPTORS; ENDOGENOUS DOPAMINE; BINDING-SITES; BABOON BRAIN AB Functional brain imaging with positron emission tomography (PET) has opened up new avenues for the investigation of possible functional disturbances related to psychiatric disease as well as pharmacodynamic assessment of drug treatment in vivo, Different strategies to study pharmacologic effects on the brain have been developed in recent years. The basic methods are to measure (a) blood flow or glucose metabolism, (b) parameters of specific receptor binding, or (c) neurotransmitter metabolism. Each of these can be performed either in a resting state or after perturbation with a pharmacologic challenge. Our group has developed a general strategy for investigating pharmacologic effects on brain function: (a) determining indirect drug-induced metabolic changes with fluorodeoxyglucose PET and (b) characterizing functional interactions of neurotransmitter systems by assaying drug-induced displacement of specific receptor ligands. These study designs reflect a paradigm shift where functional coupling of brain regions and interaction of different neurotransmitter systems are seen as the basis for a multitransmitter hypothesis of schizophrenia. In this view, any disturbance in the self-regulatory process is reflected in the loss of functional interaction between systems, An overview of recent studies and their possible clinical importance will be presented. C1 NYU MED CTR,DEPT PSYCHIAT,NEW YORK,NY 10016. NEW YORK VET ADM MED CTR,PSYCHIAT SERV,NEW YORK,NY. BROOKHAVEN NATL LAB,DEPT CHEM,UPTON,NY 11973. RI Schlosser, Ralf/F-2822-2010 FU NIMH NIH HHS [MH 49165, MH 47277]; NINDS NIH HHS [NS15638] NR 120 TC 17 Z9 17 U1 1 U2 1 PU LIPPINCOTT-RAVEN PUBL PI PHILADELPHIA PA 227 EAST WASHINGTON SQ, PHILADELPHIA, PA 19106 SN 0362-5664 J9 CLIN NEUROPHARMACOL JI Clin. Neuropharmacol. PD OCT PY 1996 VL 19 IS 5 BP 371 EP 389 DI 10.1097/00002826-199619050-00001 PG 19 WC Clinical Neurology; Pharmacology & Pharmacy SC Neurosciences & Neurology; Pharmacology & Pharmacy GA VH263 UT WOS:A1996VH26300001 PM 8889281 ER PT J AU Bedat, B Cheng, RK AF Bedat, B Cheng, RK TI Effects of buoyancy on premixed flame stabilization SO COMBUSTION AND FLAME LA English DT Article ID LAMINAR BURNING VELOCITIES; MARKSTEIN NUMBERS AB The stabilization limits of v-flame and conical flames are investigated in normal gravity (+g) and reversed gravity (upside-down burner, -g) to compare with observations of flame stabilization during microgravity experiments. The results show that buoyancy has the most influence on the stabilization of laminar v-flames. Under turbulent conditions, the effects are less significant. For conical flames stabilized with a ring, the stabilization domain of the +g and -g cases are not significantly different. Under reversed gravity, both laminar v-flames and conical dames show flame behaviors that were also found in microgravity. The v-flames reattached to the rim and the conical flame assumed a top-hat shape. One of the special cases of -g conical flame is the buoyancy-stabilized laminar flat flame that is detached from the burner. This flame implies a balance between the flow momentum and buoyant forces. The stretch rates of these flames are sufficiently low (< 20 s(-1)) such that the displacement speeds S-L are almost equal to the laminar burning speed S-L(0). An analysis based on evaluating the Richardson number is used to determine the relevant parameters that describe the buoyancy/momentum balance. A perfect balance i.e. Ri = 1 can be attained when the effect of heat loss from the flame zone is low. For the weaker lean cases, our assumption of adiabaticity tends to overestimate the real flame temperature. This interesting low-stretch laminar flame configuration can be useful for fundamental studies of combustion chemistry. C1 UNIV CALIF BERKELEY,LAWRENCE BERKELEY NATL LAB,DIV ENERGY & ENVIRONM,COMBUST GRP,BERKELEY,CA 94720. NR 14 TC 24 Z9 25 U1 1 U2 6 PU ELSEVIER SCIENCE INC PI NEW YORK PA 655 AVENUE OF THE AMERICAS, NEW YORK, NY 10010 SN 0010-2180 J9 COMBUST FLAME JI Combust. Flame PD OCT PY 1996 VL 107 IS 1-2 BP 13 EP 26 DI 10.1016/0010-2180(96)00050-8 PG 14 WC Thermodynamics; Energy & Fuels; Engineering, Multidisciplinary; Engineering, Chemical; Engineering, Mechanical SC Thermodynamics; Energy & Fuels; Engineering GA VK402 UT WOS:A1996VK40200002 ER PT J AU Goldfield, EM Gray, SK AF Goldfield, EM Gray, SK TI Mapping Coriolis-coupled quantum dynamics onto parallel computer architectures SO COMPUTER PHYSICS COMMUNICATIONS LA English DT Article DE quantum dynamics; wavepackets; parallel computing ID MECHANICAL REACTIVE SCATTERING; WAVE-PACKET APPROACH; CROSS-SECTIONS; MOLECULAR-DYNAMICS; SCHRODINGER-EQUATION; SYSTEMS; COLLISIONS; STATE AB We describe how quantum dynamics calculations with large total angular momentum quantum numbers J can be efficiently carried out on scalable parallel computers. In our approach, different processors i are associated with different allowed values of Omega, the projection quantum number of total angular momentum on a body-fixed axis. Omega can take on values Omega = 0, 1,..., J. One strategy involves associating processors i = 0, 1,..., J directly with the corresponding Omega values. Coriolis coupling permits only Omega+/-1 coupling, which implies only nearest neighbor processors need to communicate. This ''Coriolis-coupled'' parallel model and certain variations are applied to a triatomic unimolecular fragmentation process. Due to the necessity of communication between processors and load balancing issues, our model does not scale ideally with J. However, for the example considered, one can achieve wall clock times for reasonably high J values that are within about a factor of two of J=0 calculations. C1 ARGONNE NATL LAB,DIV CHEM,ARGONNE,IL 60439. RP Goldfield, EM (reprint author), WAYNE STATE UNIV,DEPT CHEM,DETROIT,MI 48202, USA. NR 46 TC 60 Z9 60 U1 3 U2 5 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0010-4655 J9 COMPUT PHYS COMMUN JI Comput. Phys. Commun. PD OCT PY 1996 VL 98 IS 1-2 BP 1 EP 14 DI 10.1016/0010-4655(96)00091-4 PG 14 WC Computer Science, Interdisciplinary Applications; Physics, Mathematical SC Computer Science; Physics GA VL414 UT WOS:A1996VL41400001 ER PT J AU Schreuders, PD Smith, ED Cole, KW Valencia, MDP Laughinghouse, A Mazur, P AF Schreuders, PD Smith, ED Cole, KW Valencia, MDP Laughinghouse, A Mazur, P TI Characterization of intraembryonic freezing in Anopheles gambiae embryos SO CRYOBIOLOGY LA English DT Article ID DROSOPHILA EMBRYOS; MOUSE EMBRYOS; CRYOPRESERVATION; VITRIFICATION AB Intraembryonic freezing (IEF) in Anopheles mosquito embryos has been evaluated by differential scanning calorimetry with respect to embryo age, temperature, rate and duration of cooling, and absence or presence of extraembryonic ice. The initial temperatures for intraembryonic ice nucleation were -30.1 +/- 0.3, -28.4 +/- 0.4, and -29.1 +/- 0.2 degrees C for embryos incubated for 15 h at 17 degrees C, 15 h at 26 degrees C, and 24 h at 26 degrees C, respectively, after oviposition. The first value is slightly but significantly lower than the latter two. These values were obtained on embryos in which the surface water was removed by brief drying; however, the values were nearly identical when external water and ice were present. Not only were the embryos of all three ages able to supercool at least transiently to -26 degrees C, but they could remain supercooled for up to 4 h at -20 degrees C after being cooled to -20 degrees C at 10 degrees C/min or (in the case of embryos incubated for 15 h at 26 degrees C) at 100 degrees C/min. The amount of freezable water in single embryos has been calculated from the differential scanning calorimetry measurements to be 3.45 +/- 0.08, 3.46 +/- 0.08, and 3.53 +/- 0.06 mu g for embryos incubated for 15 h at 17 degrees C, 15 h at 26 degrees C, and 24 h at 26 degrees C, respectively. The differences are not significant. The corresponding values for the total water contents for embryos of the three ages were 4.04 +/- 0.20, 3.72 +/- 0.16, and 3.98 +/- 0.10 mu g, values that also did not differ significantly. Water thus makes up similar to 74% of the total weight of the embryo (similar to 5.3 mu g) and about 91% of that water is freezable. Total water contents were determined gravimetrically after extensive air and vacuum drying. The kinetics of dehydration were determined during the air drying. They differed substantially among the three ages. The embryos incubated for 15 h at 17 degrees C lost water at about four times the rate of those incubated for 15 h at 26 degrees C and 10 times the rate of the embryos incubated for 24 h at 26 degrees C. (C) 1996 Academic Press, Inc. C1 OAK RIDGE NATL LAB,DIV BIOL,FUNDAMENTAL & APPL CRYOBIOL GRP,OAK RIDGE,TN 37831. NIH,PARASIT DIS LAB,BETHESDA,MD 20892. RP Schreuders, PD (reprint author), UNIV TENNESSEE,OAK RIDGE GRAD SCH BIOMED SCI,KNOXVILLE,TN, USA. FU NIAID NIH HHS [1RO1AI3624301A1] NR 28 TC 8 Z9 8 U1 0 U2 0 PU ACADEMIC PRESS INC JNL-COMP SUBSCRIPTIONS PI SAN DIEGO PA 525 B ST, STE 1900, SAN DIEGO, CA 92101-4495 SN 0011-2240 J9 CRYOBIOLOGY JI Cryobiology PD OCT PY 1996 VL 33 IS 5 BP 487 EP 501 DI 10.1006/cryo.1996.9999 PG 15 WC Biology; Physiology SC Life Sciences & Biomedicine - Other Topics; Physiology GA VQ074 UT WOS:A1996VQ07400001 PM 8893508 ER PT J AU Adriaans, MJ Moeur, WA Boyd, STP Strayer, DM Duncan, RV AF Adriaans, MJ Moeur, WA Boyd, STP Strayer, DM Duncan, RV TI Cryogenic design of the liquid helium experiment 'Critical Dynamics in Microgravity' SO CRYOGENICS LA English DT Article; Proceedings Paper CT 1995 Space Cryogenics Workshop CY JUL 25-26, 1995 CL CALVERTON, MD SP NASA, Goddard Space Flight Ctr DE superfluid helium; lambda transition; microgravity; critical phenomena ID NONLINEAR HEAT-TRANSPORT; RENORMALIZATION-GROUP THEORY; THERMAL-BOUNDARY RESISTANCE; SUPERFLUID TRANSITION; T-LAMBDA; KAPITZA RESISTANCE; HE-4; POINT; PHASE; DEPRESSION AB Although many well-controlled experiments have been conducted to measure the static properties of systems near criticality, few experiments have explored the transport properties in systems driven far away from equilibrium as a phase transition occurs. The cryogenic design of an experiment to study the dynamic aspect of critical phenomena is reported here. Measurements of the thermal gradient across the super-fluid (He Il)-normal fluid (He I) interface in helium under microgravity conditions will be performed as a heat flux holds the system away from equilibrium. New technologies are under development for this experiment, which is in the definition phase for a space shuttle flight. (C) 1996 Elsevier Science Limited C1 UNIV NEW MEXICO,ALBUQUERQUE,NM 87131. CALTECH,JET PROP LAB,PASADENA,CA 91125. RP Adriaans, MJ (reprint author), SANDIA NATL LABS,ALBUQUERQUE,NM 87185, USA. NR 35 TC 5 Z9 5 U1 0 U2 2 PU BUTTERWORTH-HEINEMANN LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD, OXON, ENGLAND OX5 1GB SN 0011-2275 J9 CRYOGENICS JI Cryogenics PD OCT PY 1996 VL 36 IS 10 BP 787 EP 794 DI 10.1016/0011-2275(96)00041-0 PG 8 WC Thermodynamics; Physics, Applied SC Thermodynamics; Physics GA VJ538 UT WOS:A1996VJ53800009 ER PT J AU Gully, WJ Hopkins, RA Cork, CP Luke, PN Madden, NW Malone, DF Pehl, RH AF Gully, WJ Hopkins, RA Cork, CP Luke, PN Madden, NW Malone, DF Pehl, RH TI Germanium gamma-ray detector operation with a flight-like mechanical cooler SO CRYOGENICS LA English DT Article; Proceedings Paper CT 1995 Space Cryogenics Workshop CY JUL 25-26, 1995 CL CALVERTON, MD SP NASA, Goddard Space Flight Ctr DE germanium detector cooling; Stirling-cycle cooler; sensor cooling AB Ball Aerospace and Lawrence Berkeley Laboratory (LBL) have successfully integrated a large germanium gamma-ray detector with a long-lifetime Stirling-cycle mechanical cooler. Testing performed at LBL in March 1995 demonstrated for the first time the compatibility of a space-quality mechanical cooler with a high-resolution germanium gamma-ray detector. The focus of the test was to investigate noise pick-up on the detector signal output caused by electromagnetic/electrostatic interference or vibration from the mechanical cooler. (C) 1996 Elsevier Science Limited C1 LAWRENCE BERKELEY LAB,BERKELEY,CA 94720. RP Gully, WJ (reprint author), BALL AEROSP SYST GRP,POB 1062,BOULDER,CO 80306, USA. NR 4 TC 2 Z9 2 U1 0 U2 0 PU BUTTERWORTH-HEINEMANN LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD, OXON, ENGLAND OX5 1GB SN 0011-2275 J9 CRYOGENICS JI Cryogenics PD OCT PY 1996 VL 36 IS 10 BP 843 EP 848 DI 10.1016/0011-2275(96)00047-1 PG 6 WC Thermodynamics; Physics, Applied SC Thermodynamics; Physics GA VJ538 UT WOS:A1996VJ53800015 ER PT J AU Sinha, SK AF Sinha, SK TI Surface structure reflectometry with X-rays SO CURRENT OPINION IN SOLID STATE & MATERIALS SCIENCE LA English DT Review ID LANGMUIR-BLODGETT-FILMS; AIR-WATER-INTERFACE; IN-SITU; REFLECTIVITY MEASUREMENTS; DIFFUSE-SCATTERING; MONOLAYERS; DIFFRACTION; ROUGHNESS; RESOLUTION; COPOLYMERS AB X-ray surface scattering is rapidly emerging as a popular technique for rapid in situ nondestructive characterization of surfaces and interfaces. Applications have been very widespread and have ranged from studies of film growth and morphology to molecular ordering at solid/liquid and free fluid interfaces. There has also been increased emphasis on the analysis of off-specular surface X-ray scattering to characterize interface roughness and growth morphology. (C) Current Chemistry Ltd RP Sinha, SK (reprint author), ARGONNE NATL LAB,ADV PHOTON SOURCE,ARGONNE,IL 60439, USA. NR 98 TC 15 Z9 15 U1 1 U2 7 PU CURRENT SCIENCE LTD PI LONDON PA 34-42 CLEVELAND STREET, LONDON, ENGLAND W1P 6LB SN 1359-0286 J9 CURR OPIN SOLID ST M JI Curr. Opin. Solid State Mat. Sci. PD OCT PY 1996 VL 1 IS 5 BP 645 EP 652 DI 10.1016/S1359-0286(96)80046-5 PG 8 WC Materials Science, Multidisciplinary; Physics, Applied; Physics, Condensed Matter SC Materials Science; Physics GA VV095 UT WOS:A1996VV09500006 ER PT J AU Sailer, BL Nastasi, AJ Valdez, JG Steinkamp, JA Crissman, HA AF Sailer, BL Nastasi, AJ Valdez, JG Steinkamp, JA Crissman, HA TI Interactions of intercalating fluorochromes with DNA analyzed by conventional and fluorescence lifetime flow cytometry utilizing deuterium oxide SO CYTOMETRY LA English DT Article DE fluorescence lifetime; propidium iodide; ethidium bromide; chromatin structure; flow cytometry; apoptosis ID ETHIDIUM-BROMIDE; CELLS; FLUOROMETER; RESOLUTION; PARTICLES; SIGNALS AB Deuterium oxide (D2O) has been shown in previous studies to increase both the fluorescence Lifetime and fluorescence intensity of propidium iodide (PI) and ethidium bromide (EB) when bound to nucleic acid structures, We have used spectroscopic analysis and conventional and phase-sensitive now cytometry to compare changes in PI and EB fluorescence intensity and lifetime bound to DNA and fixed Chinese hamster ovary (CHO) cells in the presence of D2O vs. phosphate-buffered saline (PBS), Spectroscopic and now cytometric studies showed a twofold enhancement of fluorescence intensity of PI and EB bound to fixed CHO cells in D2O and a 5 ns increase in PI and EB fluorescence lifetimes in D2O. The fluorescence lifetime of HL-60 cells stained with PI of EB was found to be 1-2 ns different from that of CHO cells, indicating that the lifetime of these fluorochromes is sensitive to chromatin configuration in different cells types. Apoptotic subpopulations of HL-60 cells had a significantly reduced fluorescence lifetime compared to nonapoptotic subpopulations. Results indicate that different chromatin states, or differences in the structures of PI and EB, lead to alterations in the fluorescence intensity and fluorescence Lifetime of these intercalating probes. (C) 1996 Wiley-Liss, Inc. C1 LOS ALAMOS NATL LAB,DIV LIFE SCI,LOS ALAMOS,NM 87545. FU NCRR NIH HHS [P41-RR01315, R01 RR06758, R01 RR07855] NR 26 TC 26 Z9 26 U1 0 U2 3 PU WILEY-LISS PI NEW YORK PA DIV JOHN WILEY & SONS INC 605 THIRD AVE, NEW YORK, NY 10158-0012 SN 0196-4763 J9 CYTOMETRY JI Cytometry PD OCT 1 PY 1996 VL 25 IS 2 BP 164 EP 172 DI 10.1002/(SICI)1097-0320(19961001)25:2<164::AID-CYTO5>3.0.CO;2-H PG 9 WC Biochemical Research Methods; Cell Biology SC Biochemistry & Molecular Biology; Cell Biology GA VK648 UT WOS:A1996VK64800006 PM 8891446 ER PT J AU Ito, G Lin, J Gable, CW AF Ito, G Lin, J Gable, CW TI Dynamics of mantle flow and melting at a ridge-centered hotspot: Iceland and the Mid-Atlantic Ridge SO EARTH AND PLANETARY SCIENCE LETTERS LA English DT Article DE Iceland; Mid-Atlantic Ridge; melting; hot spots; mantle plumes ID SPREADING-CENTER; MIGRATION BENEATH; REYKJANES-RIDGE; MAGMA MIGRATION; PLUME-RIDGE; CONVECTION; GRAVITY; TEMPERATURE; ANOMALIES; DIMENSIONS AB The dynamics of mantle flow and melting of a ridge-centered plume were investigated with three-dimensional variable-viscosity numerical models, focusing on three buoyancy sources: temperature, melt depletion, and melt retention. The width, W, to which a plume spreads along a ridge axis, depends on plume volume flux, Q, full spreading rate, U, buoyancy number, B, and ambient/plume viscosity contrast gamma. When all melting effects are considered, our numerical results are best parameterized by W=2.37(Q/U)(1/2)(B gamma)(0.04). Thermal buoyancy is first-order in controlling along-axis plume spreading while latent heat loss due to melting, and depletion and retention buoyancy forces contribute second-order effects. We propose two end-member models for the Iceland plume beneath the Mid-Atlantic Ridge (MAR). The first has a broad plume source with temperature anomaly Delta T-p of 75 degrees C, radius, a, of 300 km, and Q of 1.2x10(7) km(3)/my. The second is of a narrower and hotter plume source with Delta T-p of 170 degrees C, a radius of 60 km, and Q of 2.1x10(6) km(3)/my. The broad plume source predicts successfully the observed seismic crustal thickness, topographic, and gravity anomalies along the MAR, but predicts an along-axis geochemical plume width substantially broader than that suggested by the observed Sr-87/Sr-86 anomaly. The narrow plume source model predicts successfully the total excess crustal production rate along the MAR (2.5x10(5) km(3)/my) and a geochemical width consistent with that of the Sr-87/Sr-86 anomaly, but it requires substantial along-axis melt transport to explain the observed along-axis variations in crustal thickness, bathymetry, and gravity. Calculations suggest that lateral plume dispersion may be radially symmetric rather than channelled along the ridge axis and that the topographic swell, which is elongated along the Reykjanes Ridge, may be due to rapid off-axis subsidence associated with lithospheric cooling superimposed on a broader hotspot swell. The two plume source models predict seismic P-wave velocity reductions of 0.5-2% in the center of the plume, producing travel time delays of 0.2-1.2 s. Predicted P-wave delay times for the narrow plume source model are more consistent with recent seismic observations beneath Iceland, suggesting that this model may be more representative of the Iceland plume. C1 LOS ALAMOS NATL LAB, LOS ALAMOS, NM 87545 USA. RP WOODS HOLE OCEANOG INST, DEPT GEOL & GEOPHYS, WHOI JOINT PROGRAM, MIT, WOODS HOLE, MA 02543 USA. RI Gable, Carl/B-4689-2011; OI Gable, Carl/0000-0001-7063-0815 NR 49 TC 113 Z9 117 U1 3 U2 17 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0012-821X EI 1385-013X J9 EARTH PLANET SC LETT JI Earth Planet. Sci. Lett. PD OCT PY 1996 VL 144 IS 1-2 BP 53 EP 74 DI 10.1016/0012-821X(96)00151-3 PG 22 WC Geochemistry & Geophysics SC Geochemistry & Geophysics GA VQ227 UT WOS:A1996VQ22700006 ER PT J AU Gu, ZY Lal, D Liu, TS Southon, J Caffee, MW Guo, ZT Chen, MY AF Gu, ZY Lal, D Liu, TS Southon, J Caffee, MW Guo, ZT Chen, MY TI Five million year Be-10 record in Chinese loess and red-clay: Climate and weathering relationships SO EARTH AND PLANETARY SCIENCE LETTERS LA English DT Article DE loess Plateau; Be-10; paleoclimatology; weathering; loess AB Be-10 measurements in bulk samples, in different size fractions, in selective chemically leached fractions of several representative loess-paleosol sequences and in the underlying red-clay sediments from the Chinese Loess Plateau, back to ca. 5 Ma, were made using the AMS (accelerator mass spectrometer). Our data support but considerably extend the earlier studies of Shen and Beer and their colleagues in the upper 0.75 Ma Luochuan loess-paleosol sequences. The effect of climatic change is dramatically expressed by Be-10 concentrations: (1) in the red-clay sediments, for which we estimate model accumulation rates of 5.8 and 8.7 m Ma(-1) for the upper sequences in Lingtai and Baoji, respectively; (2) in the paleosols where soil maturation processes are manifest in the Be-10 distribution within different size fractions, accompanied by downward movement to zones of high authigenic mineral concentration; and (3) in loess samples which, at deposition, had an appreciable endowment of Be-10 from the dust source regions. On the basis of leaching experiments, we estimate that, on average, the paleosol layers lost about 3+/-3% of their initial Be-10 content to the underlying layers by transport with water. Finally, we estimate that the relative average zonal precipitation rate during glacial periods was similar to(2/3)x the average interglacial value. The estimates of the initial Be-10 concentrations and dust composition are consistent with the measured values for the recent atmospheric dust falls sampled from the Loess Plateau and the Shandong Peninsula. C1 CHINESE ACAD SCI,INST GEOL,BEIJING 100029,PEOPLES R CHINA. LAWRENCE LIVERMORE NATL LAB,CTR ACCELERATOR MASS SPECTROMETRY,LIVERMORE,CA 94551. RP Gu, ZY (reprint author), SCRIPPS INST OCEANOG,GEOSCI RES DIV,LA JOLLA,CA 92093, USA. RI Guo, Zhengtang/B-6854-2008; Caffee, Marc/K-7025-2015 OI Guo, Zhengtang/0000-0003-2259-9715; Caffee, Marc/0000-0002-6846-8967 NR 27 TC 58 Z9 74 U1 3 U2 14 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0012-821X J9 EARTH PLANET SC LETT JI Earth Planet. Sci. Lett. PD OCT PY 1996 VL 144 IS 1-2 BP 273 EP 287 DI 10.1016/0012-821X(96)00156-2 PG 15 WC Geochemistry & Geophysics SC Geochemistry & Geophysics GA VQ227 UT WOS:A1996VQ22700021 ER PT J AU Vine, EL AF Vine, EL TI International DSM and DSM program evaluation: An INDEEP assessment SO ENERGY LA English DT Article AB We discuss the current level of demand-side management (DSM) occurring in selected European countries and review the availability of information on DSM programs and program evaluation. Thirteen European DSM programs are compared by examining such factors as motivations for program implementation, marketing methods, participation rates, total energy savings and program costs. The transfer of DSM program results and experiences found in these case studies is also discussed, as well as the lessons learned during the design, implementation and evaluation of these programs. We find that these programs represent cost-effective resources and expect that these types of DSM programs will be useful for utilities and governments in emerging utility competition and restructuring, for both energy and non-energy reasons. Published by Elsevier Science. RP Vine, EL (reprint author), UNIV CALIF BERKELEY,LAWRENCE BERKELEY LAB,BLDG 90-2000,BERKELEY,CA 94720, USA. NR 15 TC 6 Z9 6 U1 0 U2 1 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD, ENGLAND OX5 1GB SN 0360-5442 J9 ENERGY JI Energy PD OCT PY 1996 VL 21 IS 10 BP 983 EP 996 DI 10.1016/0360-5442(96)00028-X PG 14 WC Thermodynamics; Energy & Fuels SC Thermodynamics; Energy & Fuels GA VD954 UT WOS:A1996VD95400018 ER PT J AU Chandler, WU Evans, M Kolesov, A AF Chandler, WU Evans, M Kolesov, A TI Climate change mitigation - A review of cost estimates and methodologies for the post-planned economies SO ENERGY POLICY LA English DT Article DE emissions; mitigation; energy efficiency AB This paper summarizes selected studies of the potential and cost of carbon emissions mitigation strategies in the post-planned economies. The economies of the Former Soviet Union and Central and Eastern Europe present significant opportunities and serious difficulties in energy related carbon dioxide emissions mitigation. This region in 1990 accounted for over one-fifth of global energy consumption and energy related greenhouse gas emissions. Copyright (C) 1996 Elsevier Science Ltd. C1 CTR ARMS CONTROL ENERGY & ENVIRONM STUDIES, MOSCOW, RUSSIA. RP Chandler, WU (reprint author), PACIFIC NW LAB, WASHINGTON, DC USA. NR 34 TC 2 Z9 2 U1 0 U2 0 PU BUTTERWORTH-HEINEMANN LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD, OXON, ENGLAND OX5 1GB SN 0301-4215 J9 ENERG POLICY JI Energy Policy PD OCT-NOV PY 1996 VL 24 IS 10-11 BP 927 EP 935 DI 10.1016/S0301-4215(96)80358-2 PG 9 WC Energy & Fuels; Environmental Sciences; Environmental Studies SC Energy & Fuels; Environmental Sciences & Ecology GA VX502 UT WOS:A1996VX50200007 ER PT J AU Levine, MD Price, L Martin, N AF Levine, MD Price, L Martin, N TI Mitigation options for carbon dioxide emissions from buildings - A global analysis SO ENERGY POLICY LA English DT Article DE carbon dioxide emissions; buildings energy use; buildings energy efficiency ID ENERGY USE; DEVELOPING-COUNTRIES; EFFICIENCY; POLICY; SECTOR; POLAND AB Between 1971 and 1992, growth in carbon dioxide (CO2) emissions from buildings varied widely by region, ranging from 0.9% per year in the industrialized countries to 0.7% per year in Eastern Europe and the former Soviet Union and 5.9% per year in developing countries, This paper outlines energy efficiency improvements for buildings and the overall technical potential to reduce CO2 emissions by cutting growth in energy consumption in buildings, Three scenarios of future buildings CO2 emissions in 2020 were developed, Under the business as usual scenario, buildings emissions increase 90% over 1990 levels. A scenario that involves adopting more efficient energy using practices and technologies is estimated to produce CO2 emissions 50% above 1990 levels, A scenario with powerful incentives for energy efficiency could lead to CO2 emissions 28% above 1990 levels, Much of the CO2 growth is the result of population growth and growth in energy services, especially in developing countries, Policy instruments to reduce energy use and related CO2 emissions include real increases in energy prices, aggressive use of energy efficiency policies, major programs to transfer knowledge, technology, and tools for transforming markets to the developing world and continued efforts to pursue research and development in technologies and practices to increase energy efficiency in buildings. Copyright (C) Elsevier Science Ltd. RP Levine, MD (reprint author), UNIV CALIF BERKELEY,LAWRENCE BERKELEY LAB,ENERGY ANAL PROGRAM,MAILSTOP 90-4000,BERKELEY,CA 94720, USA. NR 92 TC 6 Z9 6 U1 1 U2 4 PU BUTTERWORTH-HEINEMANN LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD, OXON, ENGLAND OX5 1GB SN 0301-4215 J9 ENERG POLICY JI Energy Policy PD OCT-NOV PY 1996 VL 24 IS 10-11 BP 937 EP 949 DI 10.1016/S0301-4215(96)80359-4 PG 13 WC Energy & Fuels; Environmental Sciences; Environmental Studies SC Energy & Fuels; Environmental Sciences & Ecology GA VX502 UT WOS:A1996VX50200008 ER PT J AU Johansson, TB Williams, RH Ishitani, H Edmonds, JA AF Johansson, TB Williams, RH Ishitani, H Edmonds, JA TI Options for reducing CO2 emissions from the energy supply sector SO ENERGY POLICY LA English DT Article DE energy supply; CO2 emissions; investment ID FUEL-CELLS; COMMERCIALIZATION AB Deep reductions in CO2 emissions from the global energy system are technically feasible over the course of the next century, using various combinations of low CO2 energy technologies, Moreover, an energy future characterized by deep emissions reduction over the longer term is plausibly achievable with costs for energy services that are approximately the same as estimated future costs of energy services based on conventional energy - given adequate time (several decades) and an economic and political climate conducive to the needed innovations, Strong and sustained investments would be needed for research and development, demonstration and diffusion of a wide range of energy technologies characterized by low or zero CO2 emissions, Since at present the levels of investment are low and declining, new public and private sector energy innovation policies are needed. Copyright (C) Elsevier Science Ltd. C1 PRINCETON UNIV, CTR ENERGY & ENVIRONM STUDIES, PRINCETON, NJ 08544 USA. UNIV TOKYO, FAC ENGN, DEPT GEOSYST ENGN, TOKYO 113, JAPAN. PACIFIC NW LAB, WASHINGTON, DC 20024 USA. RP Johansson, TB (reprint author), UN, DEV PROGRAMME, 1 UNITED NAT PLAZA, NEW YORK, NY 10017 USA. NR 77 TC 19 Z9 19 U1 0 U2 2 PU BUTTERWORTH-HEINEMANN LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD, OXON, ENGLAND OX5 1GB SN 0301-4215 J9 ENERG POLICY JI Energy Policy PD OCT-NOV PY 1996 VL 24 IS 10-11 BP 985 EP 1003 DI 10.1016/S0301-4215(96)80362-4 PG 19 WC Energy & Fuels; Environmental Sciences; Environmental Studies SC Energy & Fuels; Environmental Sciences & Ecology GA VX502 UT WOS:A1996VX50200011 ER PT J AU Nijs, I Teughels, H Blum, H Hendrey, G Impens, I AF Nijs, I Teughels, H Blum, H Hendrey, G Impens, I TI Simulation of climate change with infrared heaters reduces the productivity of Lolium perenne L in summer SO ENVIRONMENTAL AND EXPERIMENTAL BOTANY LA English DT Article DE global warming; elevated CO2 concentration; free air exposure; productivity; assimilation; Lolium perenne ID ELEVATED CO2; GROWTH; TEMPERATURE; NITROGEN; ACCLIMATION; PLANTS; TISSUE AB Field-grown perennial ryegrass was subjected to climate warming and elevated CO2 concentration during summer in free air conditions (no enclosure of the vegetation). Increased foliage temperature (2.5 degrees C above fluctuating ambient) was induced by heating the stand with infrared radiation sources, modulated by an electronic control device (FATI, Free Air Temperature Increase). Enhanced CO2 was produced by a FACE system (Free Air CO2 Enrichment). Exposure to simulated climate warming drastically reduced above-ground harvestable dry matter (52% loss). The nitrogen allocated to the leaf fraction was thus concentrated into less dry matter, which enhanced the nitrogen concentration on a mass basis (+17%) but also per unit leaf area (+47%). As a consequence, CO, assimilation rates were not affected in these slower growing plants in the +2.5 degrees C treatment, and the photochemical efficiency of non-cyclic electron transport of photosystem II was also unaffected. Although the plants were grown in the field without root restrictions, long-term exposure to elevated CO, concentration induced noticeable acclimation of the photosynthetic apparatus (40% loss of fixation potential), which largely outweighed the direct stimulation in this summer period. Part of the reduced rates could be attributed to lower N concentration on a leaf area basis. The results are compared with responses of this species in sunlit conditioned greenhouses, which indicates that experiments in enclosures may underestimate effects in the field. This also emphasizes the need to validate other plant responses to climate warming and CO2 enrichment in free air conditions. C1 ETH ZURICH,INST PLANT SCI,CH-8092 ZURICH,SWITZERLAND. BROOKHAVEN NATL LAB,UPTON,NY 11973. RP Nijs, I (reprint author), UNIV INSTELLING ANTWERP,DEPT BIOL,LAB PLANT ECOL,UNIV PL 1,B-2610 WILRIJK,BELGIUM. NR 22 TC 37 Z9 44 U1 0 U2 9 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD, ENGLAND OX5 1GB SN 0098-8472 J9 ENVIRON EXP BOT JI Environ. Exp. Bot. PD OCT PY 1996 VL 36 IS 3 BP 271 EP 280 DI 10.1016/0098-8472(96)01021-0 PG 10 WC Plant Sciences; Environmental Sciences SC Plant Sciences; Environmental Sciences & Ecology GA VJ709 UT WOS:A1996VJ70900003 ER PT J AU Frome, EL Smith, MH Littlefield, LG Neubert, RL Colyer, SP AF Frome, EL Smith, MH Littlefield, LG Neubert, RL Colyer, SP TI Statistical methods for the blood beryllium lymphocyte proliferation test SO ENVIRONMENTAL HEALTH PERSPECTIVES LA English DT Article; Proceedings Paper CT Conference on Beryllium-Related Diseases CY NOV 08-10, 1994 CL RES TRIANGLE PK, NC SP NIEHS, NIOSH, Occupat Safety & Hlth Adm, US DOE DE beryllium; chronic beryllium disease; least absolute value regression; lymphocyte proliferation test; outlier; quasi-likelihood estimation; regression; resistant estimators; statistical methods ID REGRESSION; DISEASE; MODELS AB The blood beryllium lymphocyte proliferation test (BeLPT) is a modification of the standard lymphocyte proliferation test that is used to identify persons who may have chronic beryllium disease. A major problem in the interpretation of BeLPT test results is outlying data values among the replicate well counts (approximate to 7%). A log-linear regression model is used to describe the expected well counts for each set of Be exposure conditions, and the variance of the well counts is proportional to the square of the expected count. Two outlier-resistant regression methods are used to estimate stimulation indices (SIs) and the coefficient of variation. The first approach uses least absolute values (LAV) on the log of the well counts as a method for estimation; the second approach uses a resistant regression version of maximum quasi-likelihood estimation. A major advantage of these resistant methods is that they make it unnecessary to identify and delete outliers. These two new methods for the statistical analysis of the BeLPT data and the current outlier rejection method are applied to 173 BeLPT assays. We strongly recommend the LAV method for routine analysis of the BeLPT. Outliers are important when trying to identify individuals with beryllium hypersensitivity, since these individuals typically have large positive SI values. A new method for identifying large Sis using combined data from the nonexposed group and the beryllium workers is proposed. The log(Sl)s are described with a Gaussian distribution with location and scale parameters estimated using resistant methods. This approach is applied to the test data and results are compared with those obtained from the current method. C1 OAK RIDGE INST SCI & EDUC,DIV MED SCI,OAK RIDGE,TN. RP Frome, EL (reprint author), OAK RIDGE NATL LAB,DIV MATH & COMP SCI,MATH SCI SECT,POB 2008,OAK RIDGE,TN 37831, USA. NR 24 TC 8 Z9 8 U1 1 U2 1 PU NATL INST ENVIRON HEALTH SCI PI RES TRIANGLE PK PA PO BOX 12233, RES TRIANGLE PK, NC 27709 SN 0091-6765 J9 ENVIRON HEALTH PERSP JI Environ. Health Perspect. PD OCT PY 1996 VL 104 SU 5 BP 957 EP 968 DI 10.2307/3433018 PG 12 WC Environmental Sciences; Public, Environmental & Occupational Health; Toxicology SC Environmental Sciences & Ecology; Public, Environmental & Occupational Health; Toxicology GA VU005 UT WOS:A1996VU00500018 PM 8933042 ER PT J AU Jones, TD Easterly, CE AF Jones, TD Easterly, CE TI A RASH analysis of national toxicology program data: Predictions for 30 compounds to be tested in rodent carcinogenesis experiments SO ENVIRONMENTAL HEALTH PERSPECTIVES LA English DT Article DE rodent carcinogenesis; relative potency; promotion ID COMPLEX-MIXTURES; RISK ASSESSMENTS; POTENCY DATABASE; UNIFYING CONCEPT; 44 CHEMICALS; BIOASSAYS; HEALTH AB Relative potencies for 30 compounds scheduled for carcinogenic testing in the 2-year rodent bioassays were estimated based on comparisons with a wide variety of bioassay data for benzo[a]pyrene, nicotine, cisplatin, aflatoxin B-1, and cyclophosphamide. Potential for oncogenic transformation of each of the compounds was estimated from short-term bioassays. Promoting strength was assigned on the basis of comparisons of the product of relative potency and test dose with the distribution of similar products obtained for 67 common compounds in the database of Gold et al. A potency class for promotion was assigned on the basis of whether the potency-adjusted test dosage was > 2 sigma below the mean, > 1 sigma below the mean, within +/-sigma of the mean, > sigma above the mean, or > 2 sigma above the mean, as determined from the 67 compounds. The underlying hypothesis is that a weak test dose may have a low probability of revealing a potential carcinogen, whereas a strong dose may have a high probability of producing false-positive results. Predictions are therefore directed at the central 68% of the log-normal frequency distribution according to the assumption that +/-sigma represents the ideal test dose. RP Jones, TD (reprint author), OAK RIDGE NATL LAB,HLTH SCI RES DIV,BLDG 4500-S,MS 6101,POB 2008,OAK RIDGE,TN 37831, USA. NR 22 TC 15 Z9 15 U1 0 U2 1 PU NATL INST ENVIRON HEALTH SCI PI RES TRIANGLE PK PA PO BOX 12233, RES TRIANGLE PK, NC 27709 SN 0091-6765 J9 ENVIRON HEALTH PERSP JI Environ. Health Perspect. PD OCT PY 1996 VL 104 SU 5 BP 1017 EP 1030 DI 10.2307/3433026 PG 14 WC Environmental Sciences; Public, Environmental & Occupational Health; Toxicology SC Environmental Sciences & Ecology; Public, Environmental & Occupational Health; Toxicology GA VU005 UT WOS:A1996VU00500026 PM 8933050 ER PT J AU Holford, DJ Freeman, HD AF Holford, DJ Freeman, HD TI Effectiveness of a passive subslab ventilation system in reducing radon concentrations in a home SO ENVIRONMENTAL SCIENCE & TECHNOLOGY LA English DT Article ID MITIGATION; HOUSES; GAS AB The effectiveness of a passive subslab ventilation system in reducing radon concentrations in an occupied home was investigated by measuring radon concentrations and pressure differentials during a 1-year period when a passive subslab ventilation system was being cycled on and off. Radon concentrations in the house were 30% lower during periods when the stack was open to the atmosphere. This effect was most pronounced when the home was unoccupied and during the winter and spring months. Furnace use and wind speed were the best predictors of transient changes in basement radon concentrations, whether the stack was open or closed. Pressure differential measurements show that subslab depressurization occurs when the stack is open during the winter and spring months due to bouyancy-driven air flow up the stack, but not during the summer. Numerical simulations of gas flow and radon transport into the house from the surrounding soil were calibrated to observed pressure differentials and radon concentrations. The model predicts that peak radon concentrations caused by furnace use will be reduced by flow out of the stack. However, the model is unable to account for the reduction in average radon concentrations observed while the stack is open in the winter. RP Holford, DJ (reprint author), PACIFIC NW LAB, POB 999, RICHLAND, WA 99352 USA. NR 19 TC 5 Z9 5 U1 1 U2 4 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 SN 0013-936X J9 ENVIRON SCI TECHNOL JI Environ. Sci. Technol. PD OCT PY 1996 VL 30 IS 10 BP 2914 EP 2920 DI 10.1021/es950790q PG 7 WC Engineering, Environmental; Environmental Sciences SC Engineering; Environmental Sciences & Ecology GA VL046 UT WOS:A1996VL04600025 ER PT J AU Fischer, ML Bentley, AJ Dunkin, KA Hodgson, AT Nazaroff, WW Sextro, RG Daisey, JM AF Fischer, ML Bentley, AJ Dunkin, KA Hodgson, AT Nazaroff, WW Sextro, RG Daisey, JM TI Factors affecting indoor air concentrations of volatile organic compounds at a site of subsurface gasoline contamination SO ENVIRONMENTAL SCIENCE & TECHNOLOGY LA English DT Article ID SOIL-GAS; ENTRY; TRANSPORT; BUILDINGS; DRIVEN; HOUSE AB We report a field study of soil-gas transport of volatile organic compounds (VOCs) into a building at a site contaminated with gasoline. High VOC concentrations (30-60 g m(-3)) were measured in soil gas 0.7 m below the building. Measured indoor air concentrations were similar to 10(6) lower due to a sharp gradient in soil-gas VOC concentrations between 0.1 and 0.7 m (a factor of similar to 10(3)) and the dilution of soil gas entering the building by wind-driven building ventilation (a factor of similar to 10(3)), Measurements of soil physical and biological characteristics indicate that a partial physical barrier to vertical transport in combination with microbial degradation can explain the gradient. While these factors are likely to be important to varying degrees at other sites contaminated with VOC, we conclude that (1) the results of this study cannot be directly applied to estimate indoor air quality at other sites without the risk of incurring significant errors and instead that (2) future attempts to estimate VOC transport into buildings should be made with careful attention to the identification and separation of physical and biotic effects. C1 UNIV CALIF BERKELEY,DEPT ENVIRONM SCI POLICY & MANAGEMENT,BERKELEY,CA 94720. UNIV CALIF BERKELEY,DEPT CIVIL & ENVIRONM ENGN,BERKELEY,CA 94720. RP Fischer, ML (reprint author), LAWRENCE BERKELEY LAB,INDOOR ENVIRONM PROGRAM,1 CYCLOTRON RD,BERKELEY,CA 94720, USA. RI Nazaroff, William/C-4106-2008 OI Nazaroff, William/0000-0001-5645-3357 NR 32 TC 56 Z9 57 U1 4 U2 13 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 SN 0013-936X J9 ENVIRON SCI TECHNOL JI Environ. Sci. Technol. PD OCT PY 1996 VL 30 IS 10 BP 2948 EP 2957 DI 10.1021/es950912e PG 10 WC Engineering, Environmental; Environmental Sciences SC Engineering; Environmental Sciences & Ecology GA VL046 UT WOS:A1996VL04600030 ER PT J AU Balsley, SD Brady, PV Krumhansl, JL Anderson, HL AF Balsley, SD Brady, PV Krumhansl, JL Anderson, HL TI Iodide retention by metal sulfide surfaces: Cinnabar and chalcocite SO ENVIRONMENTAL SCIENCE & TECHNOLOGY LA English DT Article ID I-129 WASTE MANAGEMENT; PYRITE OXIDATION; SYSTEMS; ADSORPTION; IRON AB ion exchange between aqueous protons and surface Hg and Cu sites on cinnabar (HgS) and chalcocite (Cu2S) are examined by potentiometric titrations at 25 degrees C in 1,0.1,0.01, and 0.001 M NaCl solutions. Cinnabar and chalcocite surfaces are negatively charged at pH > 3, presumably due to deprotonation of exposed thiol groups. Despite the anionic nature of the two metal sulfide surfaces, iodide sorbs strongly to both. Measured distribution ratios (K-d) far exceed those reported for all other minerals, maximal K-d's of 1375 mL/g (Cu2S) and 3080 mL/g (HgS) were observed between pH 4 and pH 5 and were substantial at all pH's measured (4 < pH < 10). Iodide sorption apparently occurs by exchange of hydroxyls attached to Hg and Cu sites. RP Balsley, SD (reprint author), SANDIA NATL LABS,GEOCHEM RES DEPT,POB 5800,MAILSTOP 0750,ALBUQUERQUE,NM 87185, USA. NR 18 TC 38 Z9 38 U1 0 U2 11 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 SN 0013-936X J9 ENVIRON SCI TECHNOL JI Environ. Sci. Technol. PD OCT PY 1996 VL 30 IS 10 BP 3025 EP 3027 DI 10.1021/es960083c PG 3 WC Engineering, Environmental; Environmental Sciences SC Engineering; Environmental Sciences & Ecology GA VL046 UT WOS:A1996VL04600039 ER EF