FN Thomson Reuters Web of Science™ VR 1.0 PT J AU TURCHI, PEA SLUITER, M PINSKI, FJ JOHNSON, DD NICHOLSON, DM STOCKS, GM STAUNTON, JB AF TURCHI, PEA SLUITER, M PINSKI, FJ JOHNSON, DD NICHOLSON, DM STOCKS, GM STAUNTON, JB TI 1ST-PRINCIPLES STUDY OF PHASE-STABILITY IN CU-ZN SUBSTITUTIONAL ALLOYS SO PHYSICAL REVIEW LETTERS LA English DT Article ID ELECTRONIC-STRUCTURE AB A parameter-free approach to phase stability in Cu-Zn substitutional alloys is shown to describe order-disorder phenomena and structural transformations with remarkable accuracy. The method is based on a multiple-scattering description of the electronic structure properties of the random alloy. Configurational order is treated within the generalized perturbation method and the concentration-functional theory. Thermodynamical properties of alpha and beta-brasses are derived from the cluster variation method. This advanced scheme is of general validity and is expected to yield similarly accurate results for other Hume-Rothery alloys. C1 SANDIA NATL LABS,DIV THEORET,LIVERMORE,CA 94551. UNIV WARWICK,DEPT PHYS,COVENTRY CV4 7AL,W MIDLANDS,ENGLAND. UNIV CINCINNATI,DEPT PHYS,CINCINNATI,OH 45221. OAK RIDGE NATL LAB,DIV MET & CERAM,OAK RIDGE,TN 37831. RP TURCHI, PEA (reprint author), UNIV CALIF LAWRENCE LIVERMORE NATL LAB,DIV CONDENSED MATTER L268,POB 808,LIVERMORE,CA 94550, USA. RI Sluiter, Marcel/E-6086-2010; Stocks, George Malcollm/Q-1251-2016; OI Sluiter, Marcel/0000-0002-6514-4318; Stocks, George Malcollm/0000-0002-9013-260X; Johnson, Duane/0000-0003-0794-7283 NR 21 TC 75 Z9 75 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 SEP 23 PY 1991 VL 67 IS 13 BP 1779 EP 1782 DI 10.1103/PhysRevLett.67.1779 PG 4 WC Physics, Multidisciplinary SC Physics GA GG106 UT WOS:A1991GG10600028 ER PT J AU CHEONG, SW AEPPLI, G MASON, TE MOOK, H HAYDEN, SM CANFIELD, PC FISK, Z CLAUSEN, KN MARTINEZ, JL AF CHEONG, SW AEPPLI, G MASON, TE MOOK, H HAYDEN, SM CANFIELD, PC FISK, Z CLAUSEN, KN MARTINEZ, JL TI INCOMMENSURATE MAGNETIC FLUCTUATIONS IN LA2-XSRXCUO4 SO PHYSICAL REVIEW LETTERS LA English DT Article ID NEUTRON-SCATTERING; FERMI-SURFACE; SPIN; ANTIFERROMAGNET; LA2-XBAXCUO4; EXCITATIONS; OXIDES; MODEL AB We use inelastic neutron scattering to establish the modulation vectors-delta and correlation lengths for the incommensurate magnetic fluctuations in metallic samples of La2-xSrxCuO4 with x = 0.075 and 0.14. In notation appropriate for a square lattice where the magnetic instability in the undoped case occurs at (pi,pi), the vectors-delta are along (pi,0) and (0,pi). The correlation length-zeta is larger than the distance between carriers, is weakly dependent on chi, and changes significantly between 12 and 100 K for both compositions. C1 RISO NATL LAB,DK-4000 ROSKILDE,DENMARK. OAK RIDGE NATL LAB,OAK RIDGE,TN 37831. UNIV BRISTOL,HH WILLS PHYS LAB,BRISTOL BS8 1TL,AVON,ENGLAND. UNIV CALIF LOS ALAMOS SCI LAB,LOS ALAMOS,NM 87545. INST MAX VON LAUE PAUL LANGEVIN,F-38042 GRENOBLE,FRANCE. RP CHEONG, SW (reprint author), AT&T BELL LABS,MURRAY HILL,NJ 07974, USA. RI Hayden, Stephen/F-4162-2011; Martinez, Jose/B-5371-2013; Canfield, Paul/H-2698-2014; Mason, Thomas/M-5809-2014 OI Hayden, Stephen/0000-0002-3209-027X; Martinez, Jose/0000-0001-9046-8237; Mason, Thomas/0000-0003-1880-3971 NR 28 TC 515 Z9 516 U1 4 U2 30 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 0031-9007 J9 PHYS REV LETT JI Phys. Rev. Lett. PD SEP 23 PY 1991 VL 67 IS 13 BP 1791 EP 1794 DI 10.1103/PhysRevLett.67.1791 PG 4 WC Physics, Multidisciplinary SC Physics GA GG106 UT WOS:A1991GG10600031 ER PT J AU PESHKIN, MA STRANDBURG, KJ RIVIER, N AF PESHKIN, MA STRANDBURG, KJ RIVIER, N TI ENTROPIC PREDICTIONS FOR CELLULAR NETWORKS SO PHYSICAL REVIEW LETTERS LA English DT Article ID POLYCRYSTALS; CELLS; ORDER; SOAP AB Diverse cellular systems evolve to remarkably similar stationary states. We therefore have studied and simulated a purely topological model. We use a maximum-entropy argument to predict that the average number of l-sided cells adjacent to an n-sided cell, M(l)(n), will be linear in n. One consequence is the empirically observed linearity of the total number of edges of cells adjacent to an n-sided cell, known as the Aboav-Weaire law. The prevailing justification of that law is shown to be incorrect, and thus the apparently universal experimental slope of approximately 5 remains unexplained. C1 ARGONNE NATL LAB,ARGONNE,IL 60439. UNIV LONDON IMPERIAL COLL SCI & TECHNOL,BLACKETT LAB,LONDON SW7 2BZ,ENGLAND. RP PESHKIN, MA (reprint author), NORTHWESTERN UNIV,EVANSTON,IL 60208, USA. RI Peshkin, Michael/B-7604-2009; Peshkin, Michael/D-9449-2016 OI Peshkin, Michael/0000-0001-6126-3320 NR 19 TC 82 Z9 82 U1 1 U2 4 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 0031-9007 J9 PHYS REV LETT JI Phys. Rev. Lett. PD SEP 23 PY 1991 VL 67 IS 13 BP 1803 EP 1806 DI 10.1103/PhysRevLett.67.1803 PG 4 WC Physics, Multidisciplinary SC Physics GA GG106 UT WOS:A1991GG10600034 ER PT J AU OLAMI, Z AF OLAMI, Z TI A LOCAL GROWTH-PROCESS FOR QUASI-CRYSTALS SO EUROPHYSICS LETTERS LA English DT Article ID QUASICRYSTAL; DIFFRACTION; DISORDER; ALLOY AB We define a new, simple fully local growth algorithm for quasi-crystals which generates very little disorder as the quasi-crystal is grown. This growth algorithm is based upon placing atoms at relative fivefold orientations and at fixed distances from their possible neighbors. Simulating such a growth we found that very little disorder develops as the growth proceeds. The final lattices have neither average phason strains nor anisotropy. RP OLAMI, Z (reprint author), BROOKHAVEN NATL LAB,DEPT PHYS,UPTON,NY 11973, USA. NR 15 TC 8 Z9 8 U1 0 U2 4 PU EDITIONS PHYSIQUE PI LES ULIS CEDEX PA Z I DE COURTABOEUF AVE 7 AV DU HOGGAR, BP 112, 91944 LES ULIS CEDEX, FRANCE SN 0295-5075 J9 EUROPHYS LETT JI Europhys. Lett. PD SEP 21 PY 1991 VL 16 IS 4 BP 361 EP 366 DI 10.1209/0295-5075/16/4/008 PG 6 WC Physics, Multidisciplinary SC Physics GA GG592 UT WOS:A1991GG59200008 ER PT J AU DE STASIO, G CAPASSO, C NG, W RAYCHAUDHURI, AK LIANG, SH COLE, RK GUO, ZY WALLACE, J CERRINA, F MARGARITONDO, G UNDERWOOD, J PERERA, R KORTRIGHT, J MERCANTI, D CIOTTI, MT STECCHI, A AF DE STASIO, G CAPASSO, C NG, W RAYCHAUDHURI, AK LIANG, SH COLE, RK GUO, ZY WALLACE, J CERRINA, F MARGARITONDO, G UNDERWOOD, J PERERA, R KORTRIGHT, J MERCANTI, D CIOTTI, MT STECCHI, A TI HIGH-RESOLUTION PHOTOELECTRON MICROIMAGING OF NEURON NETWORKS SO EUROPHYSICS LETTERS LA English DT Article ID UNDULATOR AB Neuron networks have been imaged with the scanning photoelectron microscope MAXIMUM, showing details in the submicron range such as axons, dendrites and their synapses. These results, obtained with the scanning photoemission microscope MAXIMUM, demonstrate that photoemission can reach the lateral resolution required for the life sciences, and prepare the way to the future use in the life sciences of techniques such as ESCA. C1 CNR, IST NEUROBIOL, I-00100 ROME, ITALY. IST NAZL FIS NUCL, FRASCATI NATL LABS, I-00044 FRASCATI, ITALY. UNIV WISCONSIN, DEPT PHYS, MADISON, WI 53706 USA. UNIV WISCONSIN, DEPT ELECT & COMP ENGN, MADISON, WI 53706 USA. UNIV WISCONSIN, CTR SYNCHROTRON RADIAT, MADISON, WI 53706 USA. ECOLE POLYTECH FED LAUSANNE, INST PHYS APPL, CH-1015 LAUSANNE, SWITZERLAND. UNIV CALIF BERKELEY LAWRENCE BERKELEY LAB, GR XRAY OPT, BERKELEY, CA 94720 USA. RP DE STASIO, G (reprint author), CNR, IST STRUTTURA MAT, VIA E FERMI 38, I-00044 FRASCATI, ITALY. RI Margaritondo, Giorgio/B-1367-2008; Gilbert, Pupa/A-6299-2010 OI Gilbert, Pupa/0000-0002-0139-2099 NR 14 TC 8 Z9 8 U1 0 U2 1 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 0295-5075 J9 EUROPHYS LETT JI Europhys. Lett. PD SEP 21 PY 1991 VL 16 IS 4 BP 411 EP 414 PG 4 WC Physics, Multidisciplinary SC Physics GA GG592 UT WOS:A1991GG59200016 ER PT J AU GOOSMAN, DR AF GOOSMAN, DR TI FORMULAS FOR FABRY-PEROT VELOCIMETER PERFORMANCE USING BOTH STRIPE AND MULTIFREQUENCY TECHNIQUES SO APPLIED OPTICS LA English DT Article AB New stripe and multifrequency techniques for Fabry-Perot velocimetry are incorporated into an analytical model for the entire system. Properties of striped interferometers (FP's) are derived. An understanding of energy flow in both striped and unstriped FP's is presented. Nine contributions to the velocity resolution are examined, and analytical approximations are provided for each of them. Formulas for the overall velocity and time resolution of each fringe are derived. Using brightness arguments to limit the maximum usable light acceptable by the system, we also derived analytical limits on the photographic writing speed of each fringe. RP GOOSMAN, DR (reprint author), UNIV CALIF LAWRENCE LIVERMORE NATL LAB,POB 808,LIVERMORE,CA 94550, USA. NR 11 TC 13 Z9 16 U1 0 U2 2 PU OPTICAL SOC AMER PI WASHINGTON PA 2010 MASSACHUSETTS AVE NW, WASHINGTON, DC 20036 SN 0003-6935 J9 APPL OPTICS JI Appl. Optics PD SEP 20 PY 1991 VL 30 IS 27 BP 3907 EP 3923 PG 17 WC Optics SC Optics GA GJ124 UT WOS:A1991GJ12400025 PM 20706482 ER PT J AU BURROWS, A SHANKAR, A VANRIPER, KA AF BURROWS, A SHANKAR, A VANRIPER, KA TI SN-1991T - GAMMA-RAY-OBSERVATORYS 1ST SUPERNOVA SO ASTROPHYSICAL JOURNAL LA English DT Article DE GAMMA-RAYS, GENERAL; STARS, SUPERNOVAE ID X-RAY; SN-1987A; LINE; GALAXIES; SN1987A; IA AB The explosion of the Type Ia supernova SN 1991T in the nearby galaxy NGC 4527 may be detected in gamma-ray lines by the recently launched Gamma-Ray Observatory (GRO). We calculate the dominant gamma-line and continuum features of the new "delayed detonation" model FDEFA1 and compare them to those for standard deflagration models W7 and cdtg7. We show that there are many useful hard photon discriminants of the Type Ia explosion mechanism that can, in principle, be detected by the OSSE and COMPTEL instruments on the GRO. Either SN 1991T, if bright enough, or one of the several Type Ia supernovae expected to be within the GRO's range during its active life, may allow us to settle the detonation/deflagration debate, verify the generic thermonuclear white dwarf model of Type Ia explosions, and calibrate the Type Ia B(max)/847 keV line flux ratio. C1 UNIV ARIZONA,DEPT ASTRON,TUCSON,AZ 85721. UNIV CALIF LOS ALAMOS SCI LAB,RADIAT TRANSPORT GRP,LOS ALAMOS,NM 87544. RP BURROWS, A (reprint author), UNIV ARIZONA,DEPT PHYS & ASTRON,TUCSON,AZ 85721, USA. NR 49 TC 13 Z9 13 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 SEP 20 PY 1991 VL 379 IS 1 BP L7 EP L11 DI 10.1086/186141 PN 2 PG 5 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA GF750 UT WOS:A1991GF75000002 ER PT J AU NORWOOD, K NOURBAKHSH, S HE, GZ NG, CY AF NORWOOD, K NOURBAKHSH, S HE, GZ NG, CY TI PHOTOIONIZATION STUDY OF SUPERSONICALLY COOLED CS FORMED IN THE EXCIMER PHOTODISSOCIATION OF CS2 SO CHEMICAL PHYSICS LETTERS LA English DT Article ID BEAM PHOTO-IONIZATION; 193 NM; SPECTROSCOPY; CLUSTERS; RESOLUTION AB The photoionization efficiency spectrum of supersonically cooled CS in the region of 1000-1100 angstrom is presented. The CS transient molecules are prepared by 193 nm photodissociation of a pulsed supersonic CS2 free jet. The ionization energy for CS is determined to be 11.318 +/- 0.007 eV. The observed PIE spectrum for CS and that for SO from the 193 nm photodissociation of a SO2 free jet support the conclusion that rotational and vibrational excitations of photofragments relax efficiently in the supersonic expansion. C1 DALIAN INST CHEM PHYS,DALIAN,PEOPLES R CHINA. IOWA STATE UNIV SCI & TECHNOL,DEPT CHEM,AMES,IA 50011. RP NORWOOD, K (reprint author), US DOE,AMES LAB,AMES,IA 50011, USA. NR 21 TC 19 Z9 19 U1 1 U2 3 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0009-2614 J9 CHEM PHYS LETT JI Chem. Phys. Lett. PD SEP 20 PY 1991 VL 184 IS 1-3 BP 147 EP 151 DI 10.1016/0009-2614(91)87179-F PG 5 WC Chemistry, Physical; Physics, Atomic, Molecular & Chemical SC Chemistry; Physics GA GH591 UT WOS:A1991GH59100026 ER PT J AU CURTISS, LA BRAND, H NICHOLAS, JB ITON, LE AF CURTISS, LA BRAND, H NICHOLAS, JB ITON, LE TI PREDICTED PROTON AFFINITIES OF H3SIO-, H3SIOH, H3SIOSIH3, AND H3SIOALH3- SO CHEMICAL PHYSICS LETTERS LA English DT Article ID TEMPERATURE-PROGRAMMED DESORPTION; FACTORS INFLUENCING ACIDITY; HYDROXYL-GROUPS; MOLECULAR-ENERGIES; SURFACE HYDROXYLS; GAUSSIAN-1 THEORY; GAS-PHASE; ZEOLITES; ABINITIO; CATALYSTS AB The proton affinities of H3SiO-, H3SiOH, H3SiOSiH3, and H3SiOAlH3- are predicted from ab initio molecular orbital theory using the recently developed GAUSSIAN-1 (G1) theory for computing accurate molecular energies. The calculated proton affinities (PA0) are 356.0, 177.4, 179.0, and 302.4 kcal/mol, respectively. The proton affinities are also reported at lower levels of theory for comparison with the G1 results. Finally, a comparison is presented of the trends in the OH stretching frequencies and proton affinities. RP CURTISS, LA (reprint author), ARGONNE NATL LAB,9700 S CASS AVE,ARGONNE,IL 60439, USA. NR 27 TC 66 Z9 66 U1 0 U2 2 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0009-2614 J9 CHEM PHYS LETT JI Chem. Phys. Lett. PD SEP 20 PY 1991 VL 184 IS 1-3 BP 215 EP 220 DI 10.1016/0009-2614(91)87190-M PG 6 WC Chemistry, Physical; Physics, Atomic, Molecular & Chemical SC Chemistry; Physics GA GH591 UT WOS:A1991GH59100037 ER PT J AU MACKINNON, RJ JOHNSON, RW AF MACKINNON, RJ JOHNSON, RW TI DIFFERENTIAL-EQUATION-BASED REPRESENTATION OF TRUNCATION ERRORS FOR ACCURATE NUMERICAL-SIMULATION SO INTERNATIONAL JOURNAL FOR NUMERICAL METHODS IN FLUIDS LA English DT Article DE HIGH-ORDER FINITE DIFFERENCE METHOD; CONVECTION DIFFUSION; UPWIND DIFFERENCING; ARTIFICIAL DIFFUSION; NAVIER-STOKES ID CONVECTION; DIFFUSION AB High-order compact finite difference schemes for two-dimensional convection-diffusion-type differential equations with constant and variable convection coefficients are derived. The governing equations are employed to represent leading truncation terms, including cross-derivatives, making the overall O(h4) schemes conform to a 3 x 3 stencil. We show that the two-dimensional constant coefficient scheme collapses to the optimal scheme for the one-dimensional case wherein the finite difference equation yields nodally exact results. The two-dimensional schemes are tested against standard model problems, including a Navier-Stokes application. Results show that the two schemes are generally more accurate, on comparable grids, than O(h2) centred differencing and commonly used O(h) and O(h3) upwinding schemes. RP MACKINNON, RJ (reprint author), EG&G IDAHO INC,IDAHO NATL ENGN LAB,IDAHO FALLS,ID 83415, USA. NR 16 TC 51 Z9 51 U1 0 U2 3 PU JOHN WILEY & SONS LTD PI W SUSSEX PA BAFFINS LANE CHICHESTER, W SUSSEX, ENGLAND PO19 1UD SN 0271-2091 J9 INT J NUMER METH FL JI Int. J. Numer. Methods Fluids PD SEP 20 PY 1991 VL 13 IS 6 BP 739 EP 757 DI 10.1002/fld.1650130606 PG 19 WC Computer Science, Interdisciplinary Applications; Mathematics, Interdisciplinary Applications; Mechanics; Physics, Fluids & Plasmas SC Computer Science; Mathematics; Mechanics; Physics GA GG012 UT WOS:A1991GG01200005 ER PT J AU PFEFFER, WD YEUNG, ES AF PFEFFER, WD YEUNG, ES TI ELECTROOSMOTICALLY DRIVEN ELECTROCHROMATOGRAPHY OF ANIONS HAVING SIMILAR ELECTROPHORETIC MOBILITIES BY ION-PAIRING SO JOURNAL OF CHROMATOGRAPHY LA English DT Article ID CAPILLARY ZONE ELECTROPHORESIS; COLUMN LIQUID-CHROMATOGRAPHY; RETENTION BEHAVIOR; CARBOXYLIC-ACIDS; SEPARATION; VOLTAGE; FLOW AB Anions of similar electrophoretic mobility are separated using an electrochromatographic technique which involves partitioning the anions, with the aid of the ion-pairing agent, tetrabutylammonium (TBA) cation, onto the surface of a reversed-phase open-tubular capillary liquid chromatographic (OTCLC) column. The anions separate based on differences in retention rather than differences in electrophoretic mobility. Resolution is easily controlled by varying the concentration of TBA in the buffer. Complete separation of anions having similar mobilities is achieved with as little as 600-mu-M TBA. Mass transfer broadening is inherently smaller for this electroosmotically driven system than that for pressure-driven OTCLC. The efficiency achieved for such a separation in a 40-cm column (N = 140 000) is twice that for a similar chromatographic separation and nearly equal to that for a similar, but poorly resolved, capillary zone electrophoretic separation. C1 IOWA STATE UNIV SCI & TECHNOL,US DOE,AMES LAB,AMES,IA 50011. IOWA STATE UNIV SCI & TECHNOL,DEPT CHEM,AMES,IA 50011. NR 25 TC 53 Z9 53 U1 0 U2 0 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0021-9673 J9 J CHROMATOGR PD SEP 20 PY 1991 VL 557 IS 1-2 BP 125 EP 136 DI 10.1016/S0021-9673(01)87127-2 PG 12 WC Chemistry, Analytical SC Chemistry GA GJ324 UT WOS:A1991GJ32400012 ER PT J AU TIE, XX ALYEA, FN CUNNOLD, DM KAO, CYJ AF TIE, XX ALYEA, FN CUNNOLD, DM KAO, CYJ TI ATMOSPHERIC METHANE - A GLOBAL 3-DIMENSIONAL MODEL STUDY SO JOURNAL OF GEOPHYSICAL RESEARCH-ATMOSPHERES LA English DT Article ID LATITUDINAL VARIATION; TROPOSPHERIC METHANE; MID-LATITUDES; RICE PADDIES; TRACE GASES; CHEMISTRY; DISTRIBUTIONS; CH4; OH AB We have developed a three-dimensional model to study global methane distributions and the transport of methane. The model includes transports, chemical reactions, and global methane sources. The calculations provide a fairly good simulation of the observed latitudinal gradient of methane and its global mean distribution in the stratosphere. The model results also suggest that rice paddies in Southeast Asia and wetlands in the high latitudes of North America can contribute to required sources for maximum of methane. The simulation also models the positive vertical gradients of methane in the troposphere of the southern hemisphere, which was observed by Fraser et al. (1984). The model analyses show that this positive gradient is the result of the interhemispheric transport of methane at upper levels of the troposphere. C1 GEORGIA INST TECHNOL, SCH ATMOSPHER & EARTH SCI, ATLANTA, GA 30332 USA. UNIV CALIF LOS ALAMOS SCI LAB, DIV EARTH & ENVIRONM SCI, LOS ALAMOS, NM 87545 USA. NR 42 TC 11 Z9 12 U1 1 U2 1 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 SEP 20 PY 1991 VL 96 IS D9 BP 17339 EP 17348 DI 10.1029/91JD01663 PG 10 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA GH375 UT WOS:A1991GH37500018 ER PT J AU AUER, LH KAO, CYJ AF AUER, LH KAO, CYJ TI FURTHER ANALYSIS OF THE GLOBAL OUTGOING LONGWAVE RADIATIVE FLUX OBSERVED BY NIMBUS SO JOURNAL OF GEOPHYSICAL RESEARCH-ATMOSPHERES LA English DT Note AB A multiyear decrease in the total global outgoing longwave radiation (OLR) is revealed by the Nimbus 7 data set. The size of the change is of the order of 1 W m-2. The data have been analyzed using spectral harmonic decomposition on the monthly averages. The two lowest order fitting coefficients (i.e., C00 and C10) directly yield the temporal behavior of the global OLR and the hemispheric difference in OLR between the northern and southern hemispheres, respectively. Using a hypothetical detrending technique, it is found that the decreasing signal in the global OLR cannot be ascribed to a drift in the instrumental sensitivity. The secular change in terms of decreasing with time is also found in C10. This represents that the OLR from the northern hemisphere is decreasing faster than that from the Southern hemisphere. Thus a single detrending fit to the instrumental sensitivity cannot remove the drift in the OLR. As a previous study showed that the annually averaged C00 variability is strongly correlated with observed variability of global mean surface air temperature (Ts), we show that C10 variability is also consistent with the relative variabilities of the hemispheric mean Ts. Finally, the analysis on the solar insolation during the same period shows that the decreasing insolation may be a contributing factor to the decrease of OLR. RP AUER, LH (reprint author), UNIV CALIF LOS ALAMOS SCI LAB, LOS ALAMOS, NM 87545 USA. NR 5 TC 2 Z9 2 U1 1 U2 1 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 SEP 20 PY 1991 VL 96 IS D9 BP 17367 EP 17370 DI 10.1029/91JD01789 PG 4 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA GH375 UT WOS:A1991GH37500022 ER PT J AU HAMMOND, BL SOTO, MM BARNETT, RN LESTER, WA AF HAMMOND, BL SOTO, MM BARNETT, RN LESTER, WA TI ON QUANTUM MONTE-CARLO FOR THE ELECTRONIC-STRUCTURE OF MOLECULES SO JOURNAL OF MOLECULAR STRUCTURE-THEOCHEM LA English DT Article ID RANDOM-WALK SIMULATION; SCHRODINGER-EQUATION; STATISTICAL ERROR; GREEN-FUNCTION; WAVE-FUNCTIONS; CHEMISTRY; SYSTEMS; ENERGY; POTENTIALS; AFFINITY AB We present recent advances in the quantum Monte Carlo (QMC) method for the electronic structure of atoms and molecules. The QMC method used here is a procedure for solving the Schrodinger equation stochastically based on the formal similarity between the Schrodinger equation and the classical diffusion equation. Quantum mechanical expectation values are obtained as Monte Carlo averages over an ensemble of random walkers undergoing diffusion, drift (from importance sampling), and branching. The power of the QMC method is that it is inherently an N-body method which can capture all of the dynamic correlation of the electrons. The approach yields highly accurate energies and has been used to determine other properties, including dipole moments and molecular geometry energy gradients. Here we present a description of the QMC method that we employ and give representative results. In addition we discuss recent progress on the calculation of transition dipole moments and developments with the "damped-core" QMC method which enables studies of molecular systems containing heavy atoms without reliance on pseudopotentials. C1 UNIV CALIF BERKELEY LAWRENCE BERKELEY LAB, DIV CHEM SCI, BERKELEY, CA 94720 USA. UNIV CALIF BERKELEY, DEPT CHEM, BERKELEY, CA 94720 USA. NR 66 TC 0 Z9 0 U1 0 U2 1 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0166-1280 J9 J MOL STRUC-THEOCHEM JI Theochem-J. Mol. Struct. PD SEP 20 PY 1991 VL 80 BP 525 EP 538 PG 14 WC Chemistry, Physical SC Chemistry GA GK087 UT WOS:A1991GK08700033 ER PT J AU RUBIN, EM KRAUSS, RM SPANGLER, EA VERSTUYFT, JG CLIFT, SM AF RUBIN, EM KRAUSS, RM SPANGLER, EA VERSTUYFT, JG CLIFT, SM TI INHIBITION OF EARLY ATHEROGENESIS IN TRANSGENIC MICE BY HUMAN APOLIPOPROTEIN-A-I SO NATURE LA English DT Article ID HIGH-DENSITY-LIPOPROTEIN; DETERMINING ATHEROSCLEROSIS SUSCEPTIBILITY; CHOLESTEROL; GENE; PATHOGENESIS; DISEASE; MOUSE AB EPIDEMIOLOGICAL surveys have identified a strong inverse relationship between the amount in the plasma of high density lipoproteins (HDL), apolipoprotein AI (ApoA-I), the major protein component of HDL, and the risk for atherosclerosis in humans 1,2. It is not known if this relationship arises from a direct antiatherogenic effect of these plasma components or if it is the result of other factors also associated with increases in ApoA-I and HDL levels. Because some strains of mice are susceptible to diet-induced formation of preatherosclerotic fatty streak lesions, and because of available techniques for the genetic manipulation of this organism, the murine system offers a unique setting in which to investigate the process of early atherogenesis. To test the hypothesis that induction of a high plasma concentration of ApoA-I and HDL would inhibit this process, we studied the effects of atherogenic diets on transgenic mice expressing high amounts of human ApoA-I. We report that transgenic mice with high plasma ApoA-I and HDL levels were significantly protected from the development of fatty streak lesions. C1 UNIV CALIF BERKELEY LAWRENCE BERKELEY LAB,DIV CELL & MOLEC BIOL,BERKELEY,CA 94720. RP RUBIN, EM (reprint author), UNIV CALIF BERKELEY LAWRENCE BERKELEY LAB,DIV RES MED & RADIAT BIOPHYS,BERKELEY,CA 94720, USA. NR 23 TC 769 Z9 783 U1 1 U2 14 PU MACMILLAN MAGAZINES LTD PI LONDON PA 4 LITTLE ESSEX STREET, LONDON, ENGLAND WC2R 3LF SN 0028-0836 J9 NATURE JI Nature PD SEP 19 PY 1991 VL 353 IS 6341 BP 265 EP 267 DI 10.1038/353265a0 PG 3 WC Multidisciplinary Sciences SC Science & Technology - Other Topics GA GF674 UT WOS:A1991GF67400062 PM 1910153 ER PT J AU BARZ, HW CEBRA, DA SCHULZ, H WESTFALL, GD AF BARZ, HW CEBRA, DA SCHULZ, H WESTFALL, GD TI EVENT SHAPE-ANALYSIS OF THE REACTION AR-40 + V-51 WITHIN A PROMPT MULTIFRAGMENTATION SCENARIO SO PHYSICS LETTERS B LA English DT Article ID HEAVY-ION COLLISIONS; STATISTICAL MULTIFRAGMENTATION; NUCLEI; MODEL AB We present the results of a multifragmentation model incorporating a primordial fragment distribution based on statistical multifragmentation followed by sequential decay of the resulting fragments. The Coulomb trajectories of the fragments are followed. The size of the emitting system and the excitation energy are chosen to reproduce the first order observables of the experimental results for 35 to 85 MeV/nucleon Ar + V collisions measured with the MSU 4-pi Array. Event-shape analysis in terms of sphericity-coplanarity is carried out and demonstrates that multifragmentation occurs in this system for all energies above 45 MeV/nucleon. C1 UNIV CALIF BERKELEY LAWRENCE BERKELEY LAB,DIV NUCL SCI,BERKELEY,CA 94720. MICHIGAN STATE UNIV,NATL SUPERCOND CYCLOTRON LAB,E LANSING,MI 48824. MICHIGAN STATE UNIV,DEPT PHYS & ASTRON,E LANSING,MI 48824. RP BARZ, HW (reprint author), ZENT INST KERNFORSCH ROSSENDORF,O-8051 DRESDEN,GERMANY. NR 8 TC 11 Z9 11 U1 0 U2 0 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0370-2693 J9 PHYS LETT B JI Phys. Lett. B PD SEP 19 PY 1991 VL 267 IS 3 BP 317 EP 320 DI 10.1016/0370-2693(91)90938-M PG 4 WC Astronomy & Astrophysics; Physics, Nuclear; Physics, Particles & Fields SC Astronomy & Astrophysics; Physics GA GH854 UT WOS:A1991GH85400001 ER PT J AU YAMAGISHI, K AF YAMAGISHI, K TI A 4D ANALOG OF KPZ(1) SO PHYSICS LETTERS B LA English DT Article ID EXTENDED CONFORMAL-SYMMETRIES; COADJOINT ORBITS; QUANTUM-GRAVITY; VIRASORO GROUP; 2-D GRAVITY; W-INFINITY; METRICS; EQUATIONS; LIMIT AB A four-dimensional analogue of residual eta- and epsilon-symmetries in the light-cone gauge formulation of 2D gravity a la Knizhnik-Polyakov-Zamolodchikov is considered. We argue that residual symmetries in the metric for self-dual gravity by Plebanski et al. precisely correspond to this. We also show that the eta-symmetry is nothing but a Kahler gauge symmetry in the gauge used by Alekseev and Shatashvili for the derivation of the induced 2D gravity action. RP YAMAGISHI, K (reprint author), UNIV CALIF LAWRENCE LIVERMORE NATL LAB,L-412,LIVERMORE,CA 94550, USA. NR 33 TC 0 Z9 0 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 SEP 19 PY 1991 VL 267 IS 3 BP 337 EP 342 DI 10.1016/0370-2693(91)90942-J PG 6 WC Astronomy & Astrophysics; Physics, Nuclear; Physics, Particles & Fields SC Astronomy & Astrophysics; Physics GA GH854 UT WOS:A1991GH85400005 ER PT J AU BERGER, MS CHANOWITZ, MS AF BERGER, MS CHANOWITZ, MS TI THE NUCLEON MOMENTUM SCALE IN WW PRODUCTION AT PROTON PROTON COLLIDERS SO PHYSICS LETTERS B LA English DT Article ID CROSS-SECTION; EQUIVALENCE THEOREM; PBARP COLLISIONS; HIGGS BOSONS; TEV; APPROXIMATION; PHYSICS AB We investigate the momentum scale of the nucleon structure functions for WW production at proton-proton colliders, computed in the effective W approximation and in the complete tree approximation. The former is dominated by a single kinematic region for which the nucleon scale Q2 = M(w)2 is appropriate, while the latter has two important regions requiring a different choice of scale. RP BERGER, MS (reprint author), UNIV CALIF BERKELEY LAWRENCE BERKELEY LAB,DIV PHYS,THEORET PHYS GRP,1 CYCLOTRON RD,BERKELEY,CA 94720, 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 0370-2693 J9 PHYS LETT B JI Phys. Lett. B PD SEP 19 PY 1991 VL 267 IS 3 BP 416 EP 421 DI 10.1016/0370-2693(91)90956-Q PG 6 WC Astronomy & Astrophysics; Physics, Nuclear; Physics, Particles & Fields SC Astronomy & Astrophysics; Physics GA GH854 UT WOS:A1991GH85400019 ER PT J AU Abreu, P Adam, W Adami, F Adye, T Akesson, T Alekseev, GD Allen, P Almehed, S Alvsvaag, SJ Amaldi, U Anassontzis, E Antilogus, P Apel, WD Apsimon, RJ Asman, B Astier, P Augustin, JE Augustinus, A Baillon, P Bambade, P Barao, F Barbiellini, G Bardin, DY Baroncelli, A Barring, O Bartl, W Battaglia, M Bates, MJ Baubillier, M Becks, KH Beeston, CJ Begalli, M Beilliere, P Belokopytov, Y Beltran, P Benedic, D Benlloch, JM Berggren, M Bertrand, D Bianchi, F Bibby, JH Bilenky, MS Billoir, P Bjarne, J Bloch, D Blyth, S Bogolubov, PN Bolognese, T Bonapart, M Bonesini, M Bonivento, W Booth, PSL Boratav, M Borgeaud, P Borisov, G Borner, H Bosio, C Bostjancic, B Botner, O Bouquet, B Bozzo, M Braibant, S Branchini, P Brand, KD Brenner, RA Bricman, C Brown, RCA Brummer, N Brunet, JM Bugge, L Buran, T Burmeister, H Buytaert, JAMA Caccia, M Calvi, M Rozas, AJC Campagne, JE Campion, A Camporesi, T Canale, V Cao, F Carena, F Carroll, L Caso, C Castelli, E Gimenez, MVC Cattai, A Cavallo, FR Cerrito, L Chan, A Charpentier, P Checchia, P Chelkov, GA Chevalier, L Chliapnikov, P Chorowicz, V Cirio, R Clara, MP Collins, P Contreras, JL Contri, R Cosme, G Couchot, F Crawley, HB Crennell, D Crosetti, G Crosland, N Crozon, M Maestro, JC Czellar, S Dagoret, S Dahl-Jensen, E Dalmagne, B Dam, M Damgaard, G Darbo, G Daubie, E Dauncey, PD Davenport, M David, P De Angelis, A De Beer, M De Boeck, H De Boer, W De Clercq, C Laso, MDMD De Groot, N De La Vaissiere, C De Lotto, B De Min, A Defoix, C Delikaris, D Delorme, S Delpierre, P Demaria, N Derkaoui, J Di Ciaccio, L Dijkstra, H Djama, F Dolbeau, J Donszelmann, M Doroba, K Dracos, M Drees, J Dris, M Dufour, Y Dulinski, W Eek, LO Eerola, PAM Ekelof, T Ekspong, G Peisert, AE Engel, JP Falaleev, V Fassouliotis, D Alonso, MF Ferrer, A Filippas, TA Firestone, A Foeth, H Fokitis, E Folegati, P Fontanelli, F Forbes, KAJ Forsbach, H Franek, B Frenkiel, P Fries, DC Frodesen, AG Fruhwirth, R Fulda-Quenzer, F Furnival, K Furstenau, H Fuster, J Gago, JM Galeazzi, G Gamba, D Garcia, C Garcia, J Gasparini, U Gavillet, P Gazos, EN Gerber, JP Giacomelli, P Glitza, KW Gokieli, R Golovatyuk, VM Cadenas, JJGY Goobar, A Gopal, G Gorski, M Gracco, V Grant, A Grard, F Graziani, E Gros, MH Grosdidier, G Gross, E Grossetete, B Gumenyuk, S Guy, J Hahn, F Hahn, M Haider, S Hajduk, Z Hakansson, A Hallgren, A Hamacher, K De Monchenault, GH Harris, FJ Heck, BW Henkes, T Herbst, I Hernandez, JJ Herquet, P Herr, H Hietanen, I Higgins, CO Higon, E Hilke, HJ Hodgson, SD Hofmokl, T Holmes, R Holmgren, SO Holthuizen, D Honore, PF Hooper, JE Horisberger, R Houlden, M Hrubec, J Hulth, PO Hultqvist, K Husson, D Hyams, BD Ioannou, P Isenhower, D Iversen, PS Jackson, JN Jalocha, P Jarlskog, G Jarry, P Jean-Marie, B Johansson, EK Johnson, D Jonker, M Jonsson, L Juillot, P Kalkanis, G Kalmus, G Kantardjian, G Kapusta, F Katsanevas, S Katsoufis, EC Keranen, R Kesteman, J Khomenko, BA Khovanski, NN King, B Kjaer, NJ Klein, H Klempt, W Klovning, A Kluit, P Koehne, JH Koene, B Kokkinias, P Kopf, M Koratzinos, M Korcyl, K Korytov, AV Korzen, B Kostukhin, V Kourkoumelis, C Kreuzberger, T Krolikowski, J Kruener-Marquis, U Krupinski, W Kucewicz, W Kurvinen, K Lacasta, C Lambropoulos, C Lamsa, JW Lanceri, L Lapin, V Laugier, JP Lauhakangas, R Leder, G Ledroit, F Lemonne, J Lenzen, G Lepeltier, V Letessier-Selvon, A Liko, D Lieb, E Lillethun, E Lindgren, J Lipniacka, A Lippi, I Llosa, R Loerstad, B Lokajicek, M Loken, JG Aguera, MAL Lopez-Fernandez, A Los, M Loukas, D Lounis, A Lozano, JJ Lucock, R Lutz, P Lyons, L Maehlum, G Maillard, J Maltezos, A Maltezos, S Mandl, F Marco, J Margoni, M Marin, JC Markou, A Marti, S Mathis, L Matorras, F Matteuzzi, C Matthiae, G Matveev, M Mazzucato, M Mc Cubbin, M Mc Nulty, R Menichetti, E Meola, G Meroni, C Meyer, WT Michelotto, M Mitaroff, WA Mitselmakher, GV Mjoernmark, U Moa, T Moeller, R Moenig, K Monge, MR Morettini, P Mueller, H Muller, H Murray, WJ Myatt, G Naraghi, F Nau-Korzen, U Navarria, FL Negri, P Nielsen, BS Nijjhar, B Nikolaenko, V Obraztsov, V Olshevski, AG Orava, R Ostankov, A Ouraou, A Pain, R Palka, H Papadopoulou, T Pape, L Passeri, A Pegoraro, M Perevozchikov, V Pernicka, M Perrotta, A Pierre, F Pimenta, M Pingot, O Pinsent, A Pol, ME Polok, G Poropat, P Privitera, P Pullia, A Pyyhtia, J Radojicic, D Ragazzi, S Ratoff, PN Read, AL Redaelli, NG Regler, M Reid, D Renton, PB Resvanis, LK Richard, F Richardson, M Ridky, J Rinaudo, G Roditi, I Romero, A Roncagliolo, I Ronchese, P Ronnqvist, C Rosenberg, EI Rossi, U Rosso, E Roudeau, P Rovelli, T Ruckstuhl, W Ruhlmann, V Ruiz, A Rybicki, K Sacquin, Y Salt, J Sanchez, E Sanchez, J Sannino, M Schaeffer, M Schael, S Schneider, H Schyns, MAE Scuri, F Segar, AM Sekulin, R Sessa, M Sette, G Seufert, R Shellard, RC Siegrist, P Simonetti, S Simonetto, F Sissakian, AN Skaali, TB Skjevling, G Smadja, G Smith, GR Smirnov, N Sosnowski, R Spassoff, TS Spiriti, E Squarcia, S Staeck, H Stanescu, C Stavropoulos, G Stichelbaut, F Stocchi, A Strauss, J Strub, R Stubenrauch, CJ Szczekowski, M Szeptycka, M Szymanski, P Tabarelli, T Tavernier, S Theodosiou, GE Tilquin, A Timmermans, J Timofeev, VG Tkatchev, LG Todorov, T Toet, DZ Tortora, L Trainor, MT Treille, D Trevisan, U Trischuk, W Tristam, G Troncon, C Tsirou, A Tsyganov, EN Turala, M Turchetta, R Turluer, ML Tuuva, T Tyapkin, IA Tyndel, M Tzamarias, S Ueberschaer, B Ueberschaer, S Ullaland, O Uvarov, VA Valenti, G Vallazza, E Ferrer, JAV Van Apeldoorn, GW Van Dam, P Van Doninck, WK Van Eijndhoven, N Vander Velde, C Varela, J Vaz, P Vegni, G Ventura, L Venus, W Verbeure, F Vertogradov, LS Vibert, L Vilanova, D Vlasov, EV Vodopyanov, AS Vollmer, M Volponi, S Voulgaris, G Voutilainen, M Vrba, V Wahlen, H Walck, C Waldner, F Wayne, M Weilhammer, P Werner, J Wetherell, AM Wickens, JH Wikne, J Wilkinson, GR Williams, WSC Winter, M Wormald, D Wormser, G Woschnagg, K Yamdagni, N Yepes, P Zaitsev, A Zalewska, A Zalewski, P Zavrtanik, D Zevgolatakos, E Zhang, G Zimin, NI Zito, M Zitoun, R Funchal, RZ Zumerle, G Zuniga, J AF Abreu, P Adam, W Adami, F Adye, T Akesson, T Alekseev, GD Allen, P Almehed, S Alvsvaag, SJ Amaldi, U Anassontzis, E Antilogus, P Apel, WD Apsimon, RJ Asman, B Astier, P Augustin, JE Augustinus, A Baillon, P Bambade, P Barao, F Barbiellini, G Bardin, DY Baroncelli, A Barring, O Bartl, W Battaglia, M Bates, MJ Baubillier, M Becks, KH Beeston, CJ Begalli, M Beilliere, P Belokopytov, Y Beltran, P Benedic, D Benlloch, JM Berggren, M Bertrand, D Bianchi, F Bibby, JH Bilenky, MS Billoir, P Bjarne, J Bloch, D Blyth, S Bogolubov, PN Bolognese, T Bonapart, M Bonesini, M Bonivento, W Booth, PSL Boratav, M Borgeaud, P Borisov, G Borner, H Bosio, C Bostjancic, B Botner, O Bouquet, B Bozzo, M Braibant, S Branchini, P Brand, KD Brenner, RA Bricman, C Brown, RCA Brummer, N Brunet, JM Bugge, L Buran, T Burmeister, H Buytaert, JAMA Caccia, M Calvi, M Rozas, AJC Campagne, JE Campion, A Camporesi, T Canale, V Cao, F Carena, F Carroll, L Caso, C Castelli, E Gimenez, MVC Cattai, A Cavallo, FR Cerrito, L Chan, A Charpentier, P Checchia, P Chelkov, GA Chevalier, L Chliapnikov, P Chorowicz, V Cirio, R Clara, MP Collins, P Contreras, JL Contri, R Cosme, G Couchot, F Crawley, HB Crennell, D Crosetti, G Crosland, N Crozon, M Maestro, JC Czellar, S Dagoret, S Dahl-Jensen, E Dalmagne, B Dam, M Damgaard, G Darbo, G Daubie, E Dauncey, PD Davenport, M David, P De Angelis, A De Beer, M De Boeck, H De Boer, W De Clercq, C Laso, MDMD De Groot, N De La Vaissiere, C De Lotto, B De Min, A Defoix, C Delikaris, D Delorme, S Delpierre, P Demaria, N Derkaoui, J Di Ciaccio, L Dijkstra, H Djama, F Dolbeau, J Donszelmann, M Doroba, K Dracos, M Drees, J Dris, M Dufour, Y Dulinski, W Eek, LO Eerola, PAM Ekelof, T Ekspong, G Peisert, AE Engel, JP Falaleev, V Fassouliotis, D Alonso, MF Ferrer, A Filippas, TA Firestone, A Foeth, H Fokitis, E Folegati, P Fontanelli, F Forbes, KAJ Forsbach, H Franek, B Frenkiel, P Fries, DC Frodesen, AG Fruhwirth, R Fulda-Quenzer, F Furnival, K Furstenau, H Fuster, J Gago, JM Galeazzi, G Gamba, D Garcia, C Garcia, J Gasparini, U Gavillet, P Gazos, EN Gerber, JP Giacomelli, P Glitza, KW Gokieli, R Golovatyuk, VM Cadenas, JJGY Goobar, A Gopal, G Gorski, M Gracco, V Grant, A Grard, F Graziani, E Gros, MH Grosdidier, G Gross, E Grossetete, B Gumenyuk, S Guy, J Hahn, F Hahn, M Haider, S Hajduk, Z Hakansson, A Hallgren, A Hamacher, K De Monchenault, GH Harris, FJ Heck, BW Henkes, T Herbst, I Hernandez, JJ Herquet, P Herr, H Hietanen, I Higgins, CO Higon, E Hilke, HJ Hodgson, SD Hofmokl, T Holmes, R Holmgren, SO Holthuizen, D Honore, PF Hooper, JE Horisberger, R Houlden, M Hrubec, J Hulth, PO Hultqvist, K Husson, D Hyams, BD Ioannou, P Isenhower, D Iversen, PS Jackson, JN Jalocha, P Jarlskog, G Jarry, P Jean-Marie, B Johansson, EK Johnson, D Jonker, M Jonsson, L Juillot, P Kalkanis, G Kalmus, G Kantardjian, G Kapusta, F Katsanevas, S Katsoufis, EC Keranen, R Kesteman, J Khomenko, BA Khovanski, NN King, B Kjaer, NJ Klein, H Klempt, W Klovning, A Kluit, P Koehne, JH Koene, B Kokkinias, P Kopf, M Koratzinos, M Korcyl, K Korytov, AV Korzen, B Kostukhin, V Kourkoumelis, C Kreuzberger, T Krolikowski, J Kruener-Marquis, U Krupinski, W Kucewicz, W Kurvinen, K Lacasta, C Lambropoulos, C Lamsa, JW Lanceri, L Lapin, V Laugier, JP Lauhakangas, R Leder, G Ledroit, F Lemonne, J Lenzen, G Lepeltier, V Letessier-Selvon, A Liko, D Lieb, E Lillethun, E Lindgren, J Lipniacka, A Lippi, I Llosa, R Loerstad, B Lokajicek, M Loken, JG Aguera, MAL Lopez-Fernandez, A Los, M Loukas, D Lounis, A Lozano, JJ Lucock, R Lutz, P Lyons, L Maehlum, G Maillard, J Maltezos, A Maltezos, S Mandl, F Marco, J Margoni, M Marin, JC Markou, A Marti, S Mathis, L Matorras, F Matteuzzi, C Matthiae, G Matveev, M Mazzucato, M Mc Cubbin, M Mc Nulty, R Menichetti, E Meola, G Meroni, C Meyer, WT Michelotto, M Mitaroff, WA Mitselmakher, GV Mjoernmark, U Moa, T Moeller, R Moenig, K Monge, MR Morettini, P Mueller, H Muller, H Murray, WJ Myatt, G Naraghi, F Nau-Korzen, U Navarria, FL Negri, P Nielsen, BS Nijjhar, B Nikolaenko, V Obraztsov, V Olshevski, AG Orava, R Ostankov, A Ouraou, A Pain, R Palka, H Papadopoulou, T Pape, L Passeri, A Pegoraro, M Perevozchikov, V Pernicka, M Perrotta, A Pierre, F Pimenta, M Pingot, O Pinsent, A Pol, ME Polok, G Poropat, P Privitera, P Pullia, A Pyyhtia, J Radojicic, D Ragazzi, S Ratoff, PN Read, AL Redaelli, NG Regler, M Reid, D Renton, PB Resvanis, LK Richard, F Richardson, M Ridky, J Rinaudo, G Roditi, I Romero, A Roncagliolo, I Ronchese, P Ronnqvist, C Rosenberg, EI Rossi, U Rosso, E Roudeau, P Rovelli, T Ruckstuhl, W Ruhlmann, V Ruiz, A Rybicki, K Sacquin, Y Salt, J Sanchez, E Sanchez, J Sannino, M Schaeffer, M Schael, S Schneider, H Schyns, MAE Scuri, F Segar, AM Sekulin, R Sessa, M Sette, G Seufert, R Shellard, RC Siegrist, P Simonetti, S Simonetto, F Sissakian, AN Skaali, TB Skjevling, G Smadja, G Smith, GR Smirnov, N Sosnowski, R Spassoff, TS Spiriti, E Squarcia, S Staeck, H Stanescu, C Stavropoulos, G Stichelbaut, F Stocchi, A Strauss, J Strub, R Stubenrauch, CJ Szczekowski, M Szeptycka, M Szymanski, P Tabarelli, T Tavernier, S Theodosiou, GE Tilquin, A Timmermans, J Timofeev, VG Tkatchev, LG Todorov, T Toet, DZ Tortora, L Trainor, MT Treille, D Trevisan, U Trischuk, W Tristam, G Troncon, C Tsirou, A Tsyganov, EN Turala, M Turchetta, R Turluer, ML Tuuva, T Tyapkin, IA Tyndel, M Tzamarias, S Ueberschaer, B Ueberschaer, S Ullaland, O Uvarov, VA Valenti, G Vallazza, E Ferrer, JAV Van Apeldoorn, GW Van Dam, P Van Doninck, WK Van Eijndhoven, N Vander Velde, C Varela, J Vaz, P Vegni, G Ventura, L Venus, W Verbeure, F Vertogradov, LS Vibert, L Vilanova, D Vlasov, EV Vodopyanov, AS Vollmer, M Volponi, S Voulgaris, G Voutilainen, M Vrba, V Wahlen, H Walck, C Waldner, F Wayne, M Weilhammer, P Werner, J Wetherell, AM Wickens, JH Wikne, J Wilkinson, GR Williams, WSC Winter, M Wormald, D Wormser, G Woschnagg, K Yamdagni, N Yepes, P Zaitsev, A Zalewska, A Zalewski, P Zavrtanik, D Zevgolatakos, E Zhang, G Zimin, NI Zito, M Zitoun, R Funchal, RZ Zumerle, G Zuniga, J TI A MEASUREMENT OF THE LIFETIME OF THE TAU-LEPTON SO PHYSICS LETTERS B LA English DT Article ID DETECTOR AB The lifetime of the tau lepton has been measured by two independent methods using a silicon microvertex detector installed in the DELPHI detector. The signed impact parameter distribution of the one prong decays yielded a lifetime of tau-tau = 321 +/- 36 (stat.) +/- 16 (syst.) fs, while the decay length distribution of three prong decays gave the result tau-tau = 310 +/- 31 (stat. ) +/- 9 (syst.) fs. The final value of the combined result was tau-tau = 314 +/- 25 fs. The ratio of the Fermi coupling constant from tau decay relative to that from muon decay was found to be 0.95 +/- 0.04, compatible with the hypothesis of lepton universality. C1 LIP, P-1000 LISBON, PORTUGAL. Osterreich Akad Wissensch, Inst Hochenergiephys, A-1050 Vienna, AUSTRIA. CEN Saclay, DPhPE, F-91191 Gif Sur Yvette, FRANCE. Rutherford Appleton Lab, Chilton OX11 0QX, Didcot, ENGLAND. Univ Lund, Dept Phys, S-22363 Lund, SWEDEN. Joint Inst Nucl Res, SU-101100 Moscow, RUSSIA. Ctr Mixto Univ Valencia CSIC, Inst Fis Corpuscular IFIC, E-46100 Burjassot Valencia, SPAIN. Univ Bergen, Dept Phys, N-5007 Bergen, NORWAY. CERN, CH-1211 Geneva 23, SWITZERLAND. 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Inst High Energy Phys, SU-142284 Protvino, Moscow Region, RUSSIA. NCSR Demokritos, Inst Nucl Phys, GR-15310 Athens, GREECE. CRN Grp DELPHI & LEPSI, Div Hautes Energies, F-67037 Strasbourg, FRANCE. Univ Instelling Antwerpen, Phys Dept, B-2610 Wilrijk, BELGIUM. ULB VUB, IIHE, B-1050 Brussels, BELGIUM. Univ Etat Mons, Fac Sci, Serv Phys Particules Elementaires, B-7000 Mons, BELGIUM. Univ Turin, Dipartimento Fis Sperimentale, I-10125 Turin, ITALY. Ist Nazl Fis Nucl, I-10125 Turin, ITALY. NIKHEF H, NL-1009 DB Amsterdam, NETHERLANDS. Univ Liverpool, Dept Phys, Liverpool L69 3BX, Merseyside, ENGLAND. Univ Uppsala, Dept Radiat Sci, S-75121 Uppsala, SWEDEN. Univ Padua, Dipartimento Fis, I-35131 Padua, ITALY. Ist Nazl Fis Nucl, I-35131 Padua, ITALY. Univ Helsinki, Res Inst High Energy Phys, SF-00170 Helsinki 17, FINLAND. Univ Oslo, Phys Dept, N-1000 Oslo 3, NORWAY. Univ Santander, Fac Ciencias, E-39005 Santander, SPAIN. Univ Roma 2, Dipartimento Fis, I-00173 Rome, ITALY. Ist Nazl Fis Nucl, I-00173 Rome, ITALY. Univ Bologna, Dipartimento Fis, I-40126 Bologna, ITALY. Ist Nazl Fis Nucl, I-40126 Bologna, ITALY. Iowa State Univ, Ames Lab, Ames, IA 50011 USA. Iowa State Univ, Dept Phys, Ames, IA 50011 USA. Univ Complutense, Dept Fis Atom Mol & Nucl, E-28040 Madrid, SPAIN. Niels Bohr Inst, DK-2100 Copenhagen O, DENMARK. Inst Nucl Studies, PL-00681 Warsaw, POLAND. Univ Warsaw, PL-00681 Warsaw, POLAND. Natl Tech Univ, Phys Dept, GR-15773 Athens, GREECE. Inst Nucl Phys, High Energy Phys Lab, PL-30055 Krakow 30, POLAND. Univ Aix Marseille 2, Fac Sci Luminy, F-13288 Marseille 09, FRANCE. RP Abreu, P (reprint author), LIP, AV ELIAS GARCIA 14, P-1000 LISBON, PORTUGAL. RI Ridky, Jan/H-6184-2014; Gomez Cadenas, Juan Jose/L-2003-2014; Zuniga, Juan/P-4385-2014; Vaz, Pedro/K-2464-2013; Rovelli, Tiziano/K-4432-2015; Fernandez-Alonso, Mercedes/F-2557-2016; Lozano-Bahilo, Julio/F-4881-2016; Olshevskiy, Alexander/I-1580-2016; Hernandez-Rey, Juan Jose/N-5955-2014; Abreu, Pedro/L-2220-2014; Barao, Fernando/O-2357-2016; Ruiz, Alberto/E-4473-2011; Zaitsev, Alexandre/B-8989-2017 OI Benlloch Baviera, Jose Maria/0000-0001-6073-1436; Tabarelli de Fatis, Tommaso/0000-0001-6262-4685; Contreras Gonzalez, Jose Luis/0000-0001-7282-2394; Lacasta, Carlos/0000-0002-2623-6252; Matteuzzi, Clara/0000-0002-4047-4521; DE MIN, ALBERTO/0000-0002-8130-9389; Demaria, Natale/0000-0003-0743-9465; Bonesini, Maurizio/0000-0001-5119-1896; Ridky, Jan/0000-0001-6697-1393; Sannino, Mario/0000-0001-7700-8383; Gomez Cadenas, Juan Jose/0000-0002-8224-7714; De Lotto, Barbara/0000-0003-3624-4480; Michelotto, Michele/0000-0001-6644-987X; Zuniga, Juan/0000-0002-1041-6451; Vaz, Pedro/0000-0002-7186-2359; Rovelli, Tiziano/0000-0002-9746-4842; Fernandez-Alonso, Mercedes/0000-0002-1311-5275; Lozano-Bahilo, Julio/0000-0003-0613-140X; Olshevskiy, Alexander/0000-0002-8902-1793; Hernandez-Rey, Juan Jose/0000-0002-1527-7200; Abreu, Pedro/0000-0002-9973-7314; Barao, Fernando/0000-0002-8346-9941; Ruiz, Alberto/0000-0002-3639-0368; Zaitsev, Alexandre/0000-0002-4961-8368 NR 16 TC 19 Z9 19 U1 0 U2 9 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0370-2693 EI 1873-2445 J9 PHYS LETT B JI Phys. Lett. B PD SEP 19 PY 1991 VL 267 IS 3 BP 422 EP 430 DI 10.1016/0370-2693(91)90957-R PG 9 WC Astronomy & Astrophysics; Physics, Nuclear; Physics, Particles & Fields SC Astronomy & Astrophysics; Physics GA GH854 UT WOS:A1991GH85400020 ER PT J AU CHOI, MG DANIELS, LM ANGELICI, RJ AF CHOI, MG DANIELS, LM ANGELICI, RJ TI SYNTHESIS AND DESULFURIZATION OF 2,5-DIHYDROTHIOPHENE TRANSITION-METAL COMPLEXES - MODELS FOR THE HYDRODESULFURIZATION (HDS) OF THIOPHENE SO INORGANIC CHEMISTRY LA English DT Article ID X-RAY; 2,3-DIHYDROTHIOPHENE; LIGAND; COORDINATION; MECHANISM; CARBONYL; CRYSTAL; SULFUR; FLUXIONALITY; DERIVATIVES AB Several S-coordinated 2,5-dihydrothiophene (2,5-DHT) transition-metal complexes were synthesized in order to determine whether or not this type of coordination promotes butadiene elimination from the 2,5-DHT ligand, a step proposed in a mechanism for the hydrodesulfurization (HDS) of thiophene. Thermal decomposition of W(CO)5(2,5-DHT) and Re2(CO)9(2,5-DHT) at 110-degrees-C [GRAPHICS] liberates butadiene and free 2,5-DHT (relative ratio 1:4). Uncoordinated 2,5-DHT itself does not decompose at 120-degrees-C after 3 days. Thus, S-coordination of 2,5-DHT to these metal centers does promote the liberation of butadiene. Upon being heated at 180-degrees-C, MCl2(2,5-DHT)2 (M = Pd, Pt) gives off mainly thiophene and free 2,5-DHT (1:1) with only a small amount of butadiene. Thus, depending on the complex either butadiene or thiophene may be evolved. The reaction of Ru3(CO)12 with 2,5-DHT forms the trinuclear (mu-2-H)Ru3(CO)9(mu-3-1-4-eta-4-DHT), whose X-ray structure determination shows that the sulfur and olefin of the 2,5-DHT coordinate to two different ruthenium atoms but also C-H cleavage occurs at C(2) forming a C-Ru bond. The structure of an S-coordinated DHT complex [Cp(PMe3)2Ru(2,5-DHT)](PF6) is also reported. C1 IOWA STATE UNIV SCI & TECHNOL,DEPT CHEM,GILMAN HALL,AMES,IA 50011. IOWA STATE UNIV SCI & TECHNOL,AMES LAB,AMES,IA 50011. NR 52 TC 29 Z9 29 U1 0 U2 4 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 SN 0020-1669 J9 INORG CHEM JI Inorg. Chem. PD SEP 18 PY 1991 VL 30 IS 19 BP 3647 EP 3651 DI 10.1021/ic00019a015 PG 5 WC Chemistry, Inorganic & Nuclear SC Chemistry GA GF762 UT WOS:A1991GF76200015 ER PT J AU HSU, WL AF HSU, WL TI MOLE FRACTIONS OF H, CH3, AND OTHER SPECIES DURING FILAMENT-ASSISTED DIAMOND GROWTH SO APPLIED PHYSICS LETTERS LA English DT Article ID ATOM CONCENTRATIONS AB Molecular beam mass spectrometry has been used to determine the concentrations of several free-radical and stable gaseous species in a hot-filament reactor under diamond-growth conditions. At a filament temperature of 2600 K, the H-atom concentration in the proximity of the growth surface was found to decrease with increasing addition of methane to the feed gas, dropping by more than an order of magnitude when the methane percentage was increased from 0.4% to 7.2%. Concurrent with this decrease, large changes in the concentration of the hydrocarbon species were observed. All numerical modeling results that have been reported to date do not include heterogeneous reactions on the filament and have failed to predict or explain these observations. Also from the measured mole fractions, the reaction H + CH4 <--> H-2 + CH3 was found to be in nonequilibrium near the surface, with the reverse rate ranging from approximately three to sixteen times larger than the forward rate. We attribute the cause of this nonequilibrium to heterogeneous reactions on the surface of the substrate. RP HSU, WL (reprint author), SANDIA NATL LABS,LIVERMORE,CA 94550, USA. NR 15 TC 167 Z9 173 U1 0 U2 4 PU AMER INST PHYSICS PI WOODBURY PA CIRCULATION FULFILLMENT DIV, 500 SUNNYSIDE BLVD, WOODBURY, NY 11797-2999 SN 0003-6951 J9 APPL PHYS LETT JI Appl. Phys. Lett. PD SEP 16 PY 1991 VL 59 IS 12 BP 1427 EP 1429 DI 10.1063/1.105276 PG 3 WC Physics, Applied SC Physics GA GF295 UT WOS:A1991GF29500012 ER PT J AU SARNA, T ZAJAC, J BOWMAN, MK TRUSCOTT, TG AF SARNA, T ZAJAC, J BOWMAN, MK TRUSCOTT, TG TI PHOTOINDUCED ELECTRON-TRANSFER REACTIONS OF ROSE-BENGAL AND SELECTED ELECTRON-DONORS SO JOURNAL OF PHOTOCHEMISTRY AND PHOTOBIOLOGY A-CHEMISTRY LA English DT Article ID XANTHENE DYES; RADICALS; PHOTOREDUCTION; GENERATION; PHOTOLYSIS; POTENTIALS AB The photoinduced electron transfer reactions of the triplet state of rose bengal (RB) and several electron donors were investigated by the complementary techniques of steady state and time-resolved electron paramagnetic resonance (EPR) and laser flash photolysis (LEP). The yield of radicals varied with the light fluence rate, RB concentration and, in particular, the electron donor used. Thus for L-dopa (dopa, dihydroxyphenylalanine) only 10% of RB anion radical (RB.-) was produced, with double the yield observed with NADH (NAD, nicotinamide adenine dinucleotide) as quencher and more than three times the yield observed with ascorbate as quencher. Quenching of the RB triplet was both reactive and physical with total quenching rate constants of 4 x 10(8) mol-1 dm3 s-1 and 8.5 x 10(8) mol-1 dm3 s-1 for ascorbate and NADH respectively. The rate constant for the photoinduced electron transfer from ascorbate to RB triplet was 1.4 x 10(8) mol-1 dm3 s-1 as determined by Fourier transform EPR (FT EPR). FT EPR spectra were spin polarized in emission at early times indicating a radical pair mechanism for the chemically induced dynamic electron polarization. Subsequent to the initial electron transfer production of radicals, a complex series of reactions was observed, which were dominated by processes such as recombination, disproportionation and secondary (bleaching) reactions. It was observed that back electron transfer reactions could be prevented by mild oxidants such as ferric compounds and duroquinone, which were efficiently reduced by RB.-. C1 ARGONNE NATL LAB,DIV CHEM,ARGONNE,IL 60439. UNIV KEELE,DEPT CHEM,KEELE ST5 5BG,STAFFS,ENGLAND. MED COLL WISCONSIN,NATL BIOMED ESR CTR,MILWAUKEE,WI 53226. RP SARNA, T (reprint author), JAGIELLONIAN UNIV,INST MOLEC BIOL,DEPT BIOPHYS,PL-31007 KRAKOW,POLAND. RI Bowman, Michael/F-4265-2011 OI Bowman, Michael/0000-0003-3464-9409 NR 31 TC 36 Z9 36 U1 3 U2 12 PU ELSEVIER SCIENCE SA LAUSANNE PI LAUSANNE 1 PA PO BOX 564, 1001 LAUSANNE 1, SWITZERLAND SN 1010-6030 J9 J PHOTOCH PHOTOBIO A JI J. Photochem. Photobiol. A-Chem. PD SEP 16 PY 1991 VL 60 IS 3 BP 295 EP 310 DI 10.1016/1010-6030(91)90032-O PG 16 WC Chemistry, Physical SC Chemistry GA GG267 UT WOS:A1991GG26700005 ER PT J AU VARMANAIR, M CHENG, JL JIN, YM WUNDERLICH, B AF VARMANAIR, M CHENG, JL JIN, YM WUNDERLICH, B TI THERMAL-PROPERTIES OF POLYSILYLENES SO MACROMOLECULES LA English DT Article ID CHAIN CONFORMATIONAL KINETICS; LINEAR MACROMOLECULES; CONDIS CRYSTALS; SMALL MOLECULES; HEAT-CAPACITY; SOLID-STATE; SPECTROSCOPIC METHODS; SEGMENTAL MOTION; POLY(DI-NORMAL-ALKYLSILANES); POLY(DI-NORMAL-HEXYLSILANE) AB Quantitative thermal analysis was carried out for poly(dimethylsilylene) (PDMSi), poly(dipentylsilylene) (PDPSi), poly(dihexylsilylene) (PDHSi), and poly(ditetradecylsilylene) (PTDSi). Heat capacities were determined from 160 K to just below the decomposition temperatures. The ATHAS computation scheme was used to compute the "vibration-only" heat capacities, C(p), from 0.1 to 1000 K by fitting the experimental C(p) below the glass transition temperature to an approximate vibrational spectrum. The C(p) of the liquid was determined from an empirical addition scheme. A glass transition temperature, T(g), could be detected for PDPSi and PDHSi at 227.4 and 220.5 K, respectively, with the corresponding values for DELTA-C(p) of 47.7 and 37.9 J/(K mol). For PTDSi a glass transition is suggested at almost-equal-to 250 K from a discussion of the heat capacity. For PDPSi there is only a small DELTA-S(d) [4 J/(K mol)]. In PDHSi and PTDSi, the observed endotherms lead to values of DELTA-S(d) of 46 and 119 J/(K mol) and account for about half of the maximum possible conformations participating in disordering. Polarizing microscopy revealed the change of the condis crystals to an isotropic state for PDPSi, PDHSi, and PTDSi at 518, 533, and 483 K, respectively. No prominent endotherm was observed in this temperature range. The short-side-chain homologue PDMSi reveals no glass transition or disordering transition and decomposes starting from 520 K. C1 UNIV TENNESSEE,DEPT CHEM,KNOXVILLE,TN 37996. OAK RIDGE NATL LAB,DIV CHEM,OAK RIDGE,TN 37831. NR 41 TC 37 Z9 37 U1 0 U2 2 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 SN 0024-9297 J9 MACROMOLECULES JI Macromolecules PD SEP 16 PY 1991 VL 24 IS 19 BP 5442 EP 5450 DI 10.1021/ma00019a035 PG 9 WC Polymer Science SC Polymer Science GA GF730 UT WOS:A1991GF73000035 ER PT J AU DEMING, TJ NOVAK, BM AF DEMING, TJ NOVAK, BM TI CHANGE OF MECHANISM BLOCK COPOLYMERIZATIONS - FORMATION OF BLOCK COPOLYMERS CONTAINING HELICAL POLYISOCYANIDE AND ELASTOMERIC POLYBUTADIENE SEGMENTS SO MACROMOLECULES LA English DT Letter ID LIVING COORDINATION POLYMERIZATION; RING-OPENING POLYMERIZATION; ALKYLIDENE COMPLEXES; NORBORNENE; PROPENE; BIS<(ETA-3-ALLYL)(TRIFLUOROACETATO)NICKEL>; CATALYST; CARBENE; SYSTEM; CHOICE C1 UNIV CALIF BERKELEY,DEPT CHEM,BERKELEY,CA 94720. UNIV CALIF BERKELEY LAWRENCE BERKELEY LAB,DIV MAT SCI,CTR ADV MAT,BERKELEY,CA 94720. RI Deming, Timothy/I-5411-2013; OI Deming, Timothy/0000-0002-0594-5025 NR 37 TC 19 Z9 19 U1 0 U2 7 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 SN 0024-9297 J9 MACROMOLECULES JI Macromolecules PD SEP 16 PY 1991 VL 24 IS 19 BP 5478 EP 5480 DI 10.1021/ma00019a043 PG 3 WC Polymer Science SC Polymer Science GA GF730 UT WOS:A1991GF73000043 ER PT J AU NOVAK, BM DAVIES, C AF NOVAK, BM DAVIES, C TI INVERSE ORGANIC INORGANIC COMPOSITE-MATERIALS .2. FREE-RADICAL ROUTES INTO NONSHRINKING SOL-GEL COMPOSITES SO MACROMOLECULES LA English DT Letter ID STRUCTURE PROPERTY BEHAVIOR; ACID CONTENT; GLASSES; CERAMERS; SILICA C1 UNIV CALIF BERKELEY LAWRENCE BERKELEY LAB,DIV MAT SCI,CTR ADV MAT,BERKELEY,CA 94720. RP NOVAK, BM (reprint author), UNIV CALIF BERKELEY,DEPT CHEM,BERKELEY,CA 94720, USA. NR 26 TC 138 Z9 138 U1 0 U2 8 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 SN 0024-9297 J9 MACROMOLECULES JI Macromolecules PD SEP 16 PY 1991 VL 24 IS 19 BP 5481 EP 5483 DI 10.1021/ma00019a044 PG 3 WC Polymer Science SC Polymer Science GA GF730 UT WOS:A1991GF73000044 ER PT J AU BERN, Z KOSOWER, DA AF BERN, Z KOSOWER, DA TI COLOR DECOMPOSITION OF ONE-LOOP AMPLITUDES IN GAUGE-THEORIES SO NUCLEAR PHYSICS B LA English DT Article ID FERMIONIC STRING MODELS; MULTI-GLUON SCATTERING; HADRON COLLIDERS; 4 DIMENSIONS; SUPERSTRINGS; ORBIFOLDS; CONSTRUCTION; INVARIANCE AB We present a decomposition of one-loop amplitudes in pure SU(N) gauge theories into a sum of products of traces of charge matrices and color-independent kinematic factors. The decomposition is the one-loop extension of the cyclic color decomposition that has come into widespread use in tree-level amplitudes. C1 FERMI NATL ACCELERATOR LAB,BATAVIA,IL 60510. RP BERN, Z (reprint author), UNIV PITTSBURGH,DEPT PHYS,PITTSBURGH,PA 15260, USA. NR 51 TC 191 Z9 191 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 SEP 16 PY 1991 VL 362 IS 1-2 BP 389 EP 448 DI 10.1016/0550-3213(91)90567-H PG 60 WC Physics, Particles & Fields SC Physics GA GC859 UT WOS:A1991GC85900016 ER PT J AU ANJOS, JC APPEL, JA BEAN, A BRACKER, SB BROWDER, TE CREMALDI, LM DUBOSCQ, JE ELLIOTT, JR ESCOBAR, CO GIBNEY, MC HARTNER, GF KARCHIN, PE KUMAR, BR LOSTY, MJ LUSTE, GJ MANTSCH, PM MARTIN, JF MCHUGH, S MENARY, SR MORRISON, RJ NASH, T PINFOLD, J PUNKAR, G PUROHIT, MV ROSS, WR SANTORO, AFS SCHMIDT, DM SHOUP, AL SLIWA, K SOKOLOFF, MD SOUZA, MHG SPERKA, D SPALDING, WJ STREETMAN, ME STUNDZIA, AB WITHERELL, MS AF ANJOS, JC APPEL, JA BEAN, A BRACKER, SB BROWDER, TE CREMALDI, LM DUBOSCQ, JE ELLIOTT, JR ESCOBAR, CO GIBNEY, MC HARTNER, GF KARCHIN, PE KUMAR, BR LOSTY, MJ LUSTE, GJ MANTSCH, PM MARTIN, JF MCHUGH, S MENARY, SR MORRISON, RJ NASH, T PINFOLD, J PUNKAR, G PUROHIT, MV ROSS, WR SANTORO, AFS SCHMIDT, DM SHOUP, AL SLIWA, K SOKOLOFF, MD SOUZA, MHG SPERKA, D SPALDING, WJ STREETMAN, ME STUNDZIA, AB WITHERELL, MS TI STUDY OF THE DECAY D+-]KBAR0E+VE SO PHYSICAL REVIEW LETTERS LA English DT Article ID EXCLUSIVE SEMILEPTONIC DECAYS; WEAK MIXING ANGLES; QUARK-MODEL; HEAVY MESONS; FORM-FACTORS; B-DECAY; POLARIZATION; LIFETIMES AB We have studied the exclusive semileptonic decay mode D+ --> K0BAR e + v(e) in the Fermilab photoproduction experiment E691. We find the ratio B(D+ --> K0BAR e + v(e))/B(D+ --> K- pi+ pi+) to be 0.66 +/- 0.09 +/- 0.14, corresponding to a D+ --> K0BAR e + v(e) branching ratio of (6.1 +/- 0.9 +/- 1.6)%. Combining this result with our measurement of the D+ lifetime, we find GAMMA(D+ --> K0BAR e + v(e)) = (5.6 +/- 0.8 +/- 1.5) x 10(10) s-1. We also find, using E691 averages, the ratio of decay rates GAMMA(D --> K* ev)/GAMMA(D --> Kev) to be 0.55 +/- 0.14. C1 UNIV CALIF SANTA BARBARA,SANTA BARBARA,CA 93106. CARLETON UNIV,OTTAWA K1S 5B6,ONTARIO,CANADA. UNIV CINCINNATI,CINCINNATI,OH 45221. UNIV COLORADO,BOULDER,CO 80309. FERMI NATL ACCELERATOR LAB,BATAVIA,IL 60510. YALE UNIV,NEW HAVEN,CT 06511. NATL RES COUNCIL CANADA,OTTAWA K1A 0R6,ONTARIO,CANADA. PRINCETON UNIV,PRINCETON,NJ 08544. UNIV SAO PAULO,SAO PAULO,BRAZIL. UNIV MISSISSIPPI,OXFORD,MS 38677. UNIV TORONTO,TORONTO M5S 1A7,ONTARIO,CANADA. RP ANJOS, JC (reprint author), CTR BRASILEIRO PESQUISAS FIS,BR-20000 RIO DE JANEIRO,BRAZIL. RI Anjos, Joao/C-8335-2013 NR 27 TC 26 Z9 26 U1 0 U2 1 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 0031-9007 J9 PHYS REV LETT JI Phys. Rev. Lett. PD SEP 16 PY 1991 VL 67 IS 12 BP 1507 EP 1510 DI 10.1103/PhysRevLett.67.1507 PG 4 WC Physics, Multidisciplinary SC Physics GA GF296 UT WOS:A1991GF29600008 ER PT J AU AMELIN, NS STAUBO, EF CSERNAI, LP TONEEV, VD GUDIMA, KK STROTTMAN, D AF AMELIN, NS STAUBO, EF CSERNAI, LP TONEEV, VD GUDIMA, KK STROTTMAN, D TI TRANSVERSE FLOW AND COLLECTIVITY IN ULTRARELATIVISTIC HEAVY-ION COLLISIONS SO PHYSICAL REVIEW LETTERS LA English DT Article ID RELATIVISTIC NUCLEAR COLLISIONS; GLUON STRING MODEL; ENERGY; DISTRIBUTIONS; SPECTRA; MATTER; VENUS AB The detectability of collective transverse flow is discussed for CERN Super Proton Synchrotron energies in Pb + Pb collisions. Calculations with a quark-qluon string model suggest there will be measurable flow in Pb + Pb reactions but not in S + S reactions at 160 GeV. Calculations of transverse flow with a fluid-dynamic model show a strong dependence on the equation of state and that the amount of flow is significantly larger than in the string model. C1 DUBNA JOINT NUCL RES INST,THEORET PHYS LAB,DUBNA,USSR. UNIV CALIF LOS ALAMOS SCI LAB,DIV THEORET,LOS ALAMOS,NM 87545. RP AMELIN, NS (reprint author), UNIV BERGEN,DEPT PHYS,ALLEGATEN 55,N-5007 BERGEN,NORWAY. NR 25 TC 91 Z9 92 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 SEP 16 PY 1991 VL 67 IS 12 BP 1523 EP 1526 DI 10.1103/PhysRevLett.67.1523 PG 4 WC Physics, Multidisciplinary SC Physics GA GF296 UT WOS:A1991GF29600012 ER PT J AU BOWMAN, DR PEASLEE, GF DESOUZA, RT CARLIN, N GELBKE, CK GONG, WG KIM, YD LISA, MA LYNCH, WG PHAIR, L TSANG, MB WILLIAMS, C COLONNA, N HANOLD, K MCMAHAN, MA WOZNIAK, GJ MORETTO, LG FRIEDMAN, WA AF BOWMAN, DR PEASLEE, GF DESOUZA, RT CARLIN, N GELBKE, CK GONG, WG KIM, YD LISA, MA LYNCH, WG PHAIR, L TSANG, MB WILLIAMS, C COLONNA, N HANOLD, K MCMAHAN, MA WOZNIAK, GJ MORETTO, LG FRIEDMAN, WA TI MULTIFRAGMENT DISINTEGRATION OF THE XE-129+AU-197 SYSTEM AT E/A = 50 MEV SO PHYSICAL REVIEW LETTERS LA English DT Article ID HEAVY-ION COLLISIONS; NUCLEAR FRAGMENTATION; STATISTICAL EMISSION; FLOW AB Multifragment disintegrations following Xe-129 + Au-197 collisions at E/A = 50 MeV have been studied with a multidetector system covering 88% of 4-pi in solid angle. The average number of intermediate-mass fragments (Z = 3-20) increases strongly as a function of charged-particle multiplicity and reaches values larger than six for the most violent collisions. The results are compared to calculations with both dynamical and statistical models. C1 MICHIGAN STATE UNIV,DEPT PHYS & ASTRON,E LANSING,MI 48824. UNIV CALIF BERKELEY LAWRENCE BERKELEY LAB,DIV ACCELERATOR & FUS RES,BERKELEY,CA 94720. UNIV CALIF BERKELEY LAWRENCE BERKELEY LAB,DIV NUCL SCI,BERKELEY,CA 94720. UNIV WISCONSIN,DEPT PHYS,MADISON,WI 53706. RP BOWMAN, DR (reprint author), MICHIGAN STATE UNIV,NATL SUPERCONDUCTING CYCLOTRON LAB,E LANSING,MI 48824, USA. RI Carlin Filho, Nelson/C-2187-2012; Lynch, William/I-1447-2013; deSouza, Romualdo/P-5862-2015 OI Lynch, William/0000-0003-4503-176X; deSouza, Romualdo/0000-0001-5835-677X NR 25 TC 176 Z9 177 U1 1 U2 1 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 0031-9007 J9 PHYS REV LETT JI Phys. Rev. Lett. PD SEP 16 PY 1991 VL 67 IS 12 BP 1527 EP 1536 DI 10.1103/PhysRevLett.67.1527 PG 10 WC Physics, Multidisciplinary SC Physics GA GF296 UT WOS:A1991GF29600013 ER PT J AU GU, C WU, X OLSON, CG LYNCH, DW AF GU, C WU, X OLSON, CG LYNCH, DW TI GAMMA-ALPHA-PHASE TRANSITION OF MONOLAYER CE ON W(110) SO PHYSICAL REVIEW LETTERS LA English DT Article ID LOW-ENERGY EXCITATIONS; ELECTRONIC-STRUCTURE; PHOTOEMISSION; CERIUM AB As Ce is adsorbed on a W(110) substrate at 300 K an epitaxial layer develops at a coverage of 0.5 monolayer. LEED patterns indicate a hexagonal pattern consistent with Ce(111). As Ce is added, the lattice parameter shrinks continuously from 9% larger than that for gamma-Ce to 3% smaller than that for alpha-Ce. 4f photoelectron spectra reveal two peaks similar to those of gamma-Ce, changing relative intensity with increasing coverage to resemble those of alpha-Ce. C1 IOWA STATE UNIV SCI & TECHNOL,DEPT PHYS & ASTRON,AMES,IA 50011. RP GU, C (reprint author), IOWA STATE UNIV SCI & TECHNOL,US DOE,AMES LAB,AMES,IA 50011, USA. NR 27 TC 28 Z9 28 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 SEP 16 PY 1991 VL 67 IS 12 BP 1622 EP 1625 DI 10.1103/PhysRevLett.67.1622 PG 4 WC Physics, Multidisciplinary SC Physics GA GF296 UT WOS:A1991GF29600037 ER PT J AU QIU, ZQ PEARSON, J BADER, SD AF QIU, ZQ PEARSON, J BADER, SD TI MAGNETIC PHASE-TRANSITION OF ULTRATHIN FE FILMS ON AG(111) SO PHYSICAL REVIEW LETTERS LA English DT Article ID XY-MODEL; SURFACE; FERROMAGNETISM; ANISOTROPY; OVERLAYERS; BEHAVIOR; AG(001); IRON AB High-quality, single-crystalline films of Fe(110)/Ag(111) were grown by molecular-beam epitaxy in the range of approximately 1-3 monolayers of Fe, and investigated in situ by means of the surface magneto-optic Kerr effect. The magnetization exhibits a second-order phase transition at a thickness-dependent Curie temperature. The value of the critical exponent-beta of 0.137 +/- 0.008 is in good agreement with that of the two-dimensional Ising model. RP QIU, ZQ (reprint author), ARGONNE NATL LAB,DIV MAT SCI,ARGONNE,IL 60439, USA. RI Bader, Samuel/A-2995-2013; Qiu, Zi Qiang/O-4421-2016 OI Qiu, Zi Qiang/0000-0003-0680-0714 NR 29 TC 92 Z9 97 U1 1 U2 5 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 0031-9007 J9 PHYS REV LETT JI Phys. Rev. Lett. PD SEP 16 PY 1991 VL 67 IS 12 BP 1646 EP 1649 DI 10.1103/PhysRevLett.67.1646 PG 4 WC Physics, Multidisciplinary SC Physics GA GF296 UT WOS:A1991GF29600043 ER PT J AU MCCUNE, W WOS, L AF MCCUNE, W WOS, L TI THE ABSENCE AND THE PRESENCE OF FIXED-POINT COMBINATORS SO THEORETICAL COMPUTER SCIENCE LA English DT Note AB In this article we give some classes of fragments of weak combinatory logic and show that they fail to admit various fixed point properties. We also present the results of a new technique, the kernel strategy, for using an automated theorem-proving program to search for fixed point combinators within a given fragment. A key aspect of the work is that experimentation with the kernel strategy led indirectly to proofs of theorems concerning the absence of the fixed point properties. RP MCCUNE, W (reprint author), ARGONNE NATL LAB,DIV MATH & COMP SCI,ARGONNE,IL 60439, USA. NR 12 TC 4 Z9 4 U1 0 U2 0 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0304-3975 J9 THEOR COMPUT SCI JI Theor. Comput. Sci. PD SEP 16 PY 1991 VL 87 IS 1 BP 221 EP 228 DI 10.1016/0304-3975(91)90034-Y PG 8 WC Computer Science, Theory & Methods SC Computer Science GA GG797 UT WOS:A1991GG79700012 ER PT J AU DAROVSKY, A WU, LY LEE, P SHEU, HS AF DAROVSKY, A WU, LY LEE, P SHEU, HS TI STRUCTURE OF BIS(PHTHALOCYANINATO)PRASEODYMIUM (BETA-1-PHASE) SO ACTA CRYSTALLOGRAPHICA SECTION C-CRYSTAL STRUCTURE COMMUNICATIONS LA English DT Article AB [Pr(C32H16N8)2], M(r) = 1165.9, monoclinic, I2/c, a = 13.383 (2), b = 14.154 (3), c = 25.644 (7) angstrom, beta = 83.32-degrees, V = 4824.6 (2) angstrom 3, Z = 4, D(x) = 1.605 Mg m-3, lambda(Mo K-alpha) = 0.7093 angstrom, mu = 1.07 mm-1, F(000) = 2348, room temperature, R = 0.026 for 3562 observed reflections. The Pr atom has a distorted antiprism coordination with four N atoms from each of two ligands. A new type of molecular packing (hereafter the beta-1 phase) is found in which the sandwich-like molecules are shifted in alternating directions from the molecular stack axis by 2.6 angstrom. C1 SUNY BUFFALO,DEPT CHEM,BUFFALO,NY 14214. SRRC,HSINCHU 30077,TAIWAN. RP DAROVSKY, A (reprint author), SUNY X3,BROOKHAVEN NATL LAB,NATL SYNCHROTRON LIGHT SOURCE,UPTON,NY 11973, USA. NR 7 TC 28 Z9 28 U1 0 U2 0 PU MUNKSGAARD INT PUBL LTD PI COPENHAGEN PA 35 NORRE SOGADE, PO BOX 2148, DK-1016 COPENHAGEN, DENMARK SN 0108-2701 J9 ACTA CRYSTALLOGR C JI Acta Crystallogr. Sect. C-Cryst. Struct. Commun. PD SEP 15 PY 1991 VL 47 BP 1836 EP 1838 DI 10.1107/S0108270191002895 PN 9 PG 3 WC Chemistry, Multidisciplinary; Crystallography SC Chemistry; Crystallography GA GH168 UT WOS:A1991GH16800022 ER PT J AU SACHLEBEN, RA BURNS, JH AF SACHLEBEN, RA BURNS, JH TI LITHIUM DIBENZO-14-CROWN-4-ACETATE ETHANOL (2/1) SO ACTA CRYSTALLOGRAPHICA SECTION C-CRYSTAL STRUCTURE COMMUNICATIONS LA English DT Note ID ACID; COMPLEXATION; CRYSTAL; ETHERS; METAL AB (Dibenzo[b,i][1,4,8,11]tetraoxacyclotetradeca-2,9-dien-6-ylacetato)lithium-ethanol (2/1), [Li-(C20H21O6)].0.5C2H5OH, M(r) = 387.36, monoclinic, P2(1)/n, a = 9.970 (4), b = 9.900 (2), c = 19.79 (1) angstrom, beta = 102.09-degrees, V = 1910 (2) angstrom 3, Z = 4, D(x) = 1.35 g cm-3, Mo K-alphaBAR radiaton, lambda = 0.71069 angstrom, mu = 0.93 cm-1, F(000) = 820, T = 295 K, R = 0.048 for 1608 reflections with I > sigma(I). The acetate side arm is attached to the macrocycle in a pseudo-equatorial position, and there is no intramolecular cation-anion bonding. Instead, dimers are formed by intermolecular bonding between pairs of acetate and Li+ ions. RP SACHLEBEN, RA (reprint author), OAK RIDGE NATL LAB,DIV CHEM,OAK RIDGE,TN 37831, USA. NR 6 TC 9 Z9 9 U1 0 U2 0 PU MUNKSGAARD INT PUBL LTD PI COPENHAGEN PA 35 NORRE SOGADE, PO BOX 2148, DK-1016 COPENHAGEN, DENMARK SN 0108-2701 J9 ACTA CRYSTALLOGR C JI Acta Crystallogr. Sect. C-Cryst. Struct. Commun. PD SEP 15 PY 1991 VL 47 BP 1968 EP 1969 DI 10.1107/S0108270191002858 PN 9 PG 2 WC Chemistry, Multidisciplinary; Crystallography SC Chemistry; Crystallography GA GH168 UT WOS:A1991GH16800070 ER PT J AU ROJAS, D SILVA, RJ SPEAR, JD RUSSO, RE AF ROJAS, D SILVA, RJ SPEAR, JD RUSSO, RE TI DUAL-BEAM OPTICAL FIBER THERMAL LENS SPECTROSCOPY SO ANALYTICAL CHEMISTRY LA English DT Article ID LASER EXCITATION; SPECTROPHOTOMETRY; SPECTROMETRY; PHOSPHORUS; SAMPLES AB A dual-beam thermal lens optical fiber spectrometer was developed and tested with aqueous solutions of the rare-earth ion Nd3+. An argon ion pumped dye laser beam was delivered to a sample cuvette through optical fibers of 100, 200, and 400-mu-m core diameter. The thermal lens signal was detected with a He-Ne laser guided to a photodiode detector by an optical fiber of 200-mu-m core diameter. Theoretical values for the optical aperture, excitation and probe beam radii, and distances from the sample to the probe beam waist and to the aperture-detector were calculated and compared to experimental results. Theoretical thermal lens enhancement factors that take into account the radius of the excitation beam show good agreement with the experimental values. A detection limit of 7 x 10(-6) M and an enhancement factor of 0.9 were obtained for an incident power of 25 mW and a power density of 31 W cm-2. C1 UNIV CALIF BERKELEY LAWRENCE BERKELEY LAB,DIV APPL SCI,MS 90-2024,BERKELEY,CA 94720. NR 24 TC 12 Z9 12 U1 1 U2 2 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 SN 0003-2700 J9 ANAL CHEM JI Anal. Chem. PD SEP 15 PY 1991 VL 63 IS 18 BP 1927 EP 1932 DI 10.1021/ac00018a007 PG 6 WC Chemistry, Analytical SC Chemistry GA GE858 UT WOS:A1991GE85800007 ER PT J AU MCLUCKEY, SA GLISH, GL VANBERKEL, GJ AF MCLUCKEY, SA GLISH, GL VANBERKEL, GJ TI CHARGE DETERMINATION OF PRODUCT IONS FORMED FROM COLLISION-INDUCED DISSOCIATION OF MULTIPLY PROTONATED MOLECULES VIA ION MOLECULE REACTIONS SO ANALYTICAL CHEMISTRY LA English DT Article ID TANDEM MASS-SPECTROMETRY; ELECTROSPRAY IONIZATION; CYTOCHROME-C; ACTIVATED DISSOCIATION; TRAP; BIOMOLECULES; POLYPEPTIDES; SPECTRA AB The use of ion/molecule reactions involving multiply protonated ions derived from electrospray for the determination of the charges of product ions formed from collision-induced dissociation is described. The experiments are carried out with a quadrupole ion trap capable of multiple stages of mass spectrometry. The approach is illustrated with proton transfer from a product ion from quadruply protonated melittin, and from a product ion from the (M + 20H)20+ ion from horse myoglobin, to 1,6-diaminohexane. The major product ion from quadruply protonated bovine insulin is used to illustrate the use of a clustering reaction with 1,6-diaminohexane. The ion trap is shown to be a particularly useful tool for employing both collisional activation and low-energy ion/molecule reactions in the same experiment to determine product ion charge. RP MCLUCKEY, SA (reprint author), OAK RIDGE NATL LAB,DIV ANALYT CHEM,OAK RIDGE,TN 37831, USA. RI McLuckey, Scott/B-2203-2009 OI McLuckey, Scott/0000-0002-1648-5570 NR 33 TC 109 Z9 109 U1 1 U2 10 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 SN 0003-2700 J9 ANAL CHEM JI Anal. Chem. PD SEP 15 PY 1991 VL 63 IS 18 BP 1971 EP 1978 DI 10.1021/ac00018a014 PG 8 WC Chemistry, Analytical SC Chemistry GA GE858 UT WOS:A1991GE85800014 PM 1661106 ER PT J AU CHEN, J FRITZ, JS AF CHEN, J FRITZ, JS TI GAS-CHROMATOGRAPHIC DETERMINATION OF WATER AFTER REACTION WITH TRIETHYL ORTHOFORMATE SO ANALYTICAL CHEMISTRY LA English DT Article AB The amount of water in analytical samples is determined by reaction with an ortho ester (such as triethyl orthoformate), followed by measurement of a product of the reaction by capillary-column GC. A low concentration of methanesulfonic acid is dissolved in the reagent to catalyze the reaction. Ortho esters are shown to react more completely with water than 2,2-dimethoxypropane, which was used in a previous method. A complete determination of water, including the chromatographic separation, requires only about 5 min. Various experimental parameters are investigated to optimize the method. The amount of water was determined in a large variety of liquid and solid samples. C1 US DOE,AMES LAB,AMES,IA 50011. IOWA STATE UNIV SCI & TECHNOL,DEPT CHEM,AMES,IA 50011. NR 16 TC 11 Z9 11 U1 0 U2 0 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 SN 0003-2700 J9 ANAL CHEM JI Anal. Chem. PD SEP 15 PY 1991 VL 63 IS 18 BP 2016 EP 2020 DI 10.1021/ac00018a022 PG 5 WC Chemistry, Analytical SC Chemistry GA GE858 UT WOS:A1991GE85800022 ER PT J AU VANBERKEL, GJ MCLUCKEY, SA GLISH, GL AF VANBERKEL, GJ MCLUCKEY, SA GLISH, GL TI PREFORMING IONS IN SOLUTION VIA CHARGE-TRANSFER COMPLEXATION FOR ANALYSIS BY ELECTROSPRAY IONIZATION MASS-SPECTROMETRY SO ANALYTICAL CHEMISTRY LA English DT Letter ID GAS-PHASE; BIOMOLECULES RP VANBERKEL, GJ (reprint author), OAK RIDGE NATL LAB,DIV ANALYT CHEM,OAK RIDGE,TN 37831, USA. RI McLuckey, Scott/B-2203-2009 OI McLuckey, Scott/0000-0002-1648-5570 NR 24 TC 66 Z9 66 U1 2 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 SEP 15 PY 1991 VL 63 IS 18 BP 2064 EP 2068 DI 10.1021/ac00018a032 PG 5 WC Chemistry, Analytical SC Chemistry GA GE858 UT WOS:A1991GE85800032 ER PT J AU FUJIMORI, K FISHER, DR WEINSTEIN, JN AF FUJIMORI, K FISHER, DR WEINSTEIN, JN TI INTEGRATED MICROSCOPIC-MACROSCOPIC PHARMACOLOGY OF MONOCLONAL-ANTIBODY RADIOCONJUGATES - THE RADIATION-DOSE DISTRIBUTION SO CANCER RESEARCH LA English DT Article ID SOLID TUMORS; INTERSTITIAL PRESSURE; MODELING ANALYSIS; BLOOD-FLOW; MACROMOLECULES; PERMEABILITY; RADIOIMMUNOTHERAPY; MICROVASCULATURE; XENOGRAFTS; THERAPY AB Accurate dosimetry is essential for the assessment of radioimmunotherapy. Most often studied to date has been the macroscopic dosimetry related to organ and tumor distribution of the radiolabeled antibody, but the question of microscopic dose heterogeneity is also important. To address the latter issue, we have taken an integrated approach to the pharmacology, taking into account whole-body distribution, transcapillary transport, percolation through the tumor interstitial space, antigen-antibody interaction, and antibody metabolism. The first step is to simulate the spatial antibody concentration profile in a tumor as a function of time after i.v. (e.g., bolus) injection, using reasonable values for the parameters involved. The second step is to calculate, also as a function of time, the absorbed radiation dose distribution resulting from each concentration profile. Parameter values for IgG pharmacology and a radiation point source function for I-131 are used to explore the effect of antibody distribution profiles on absorbed dose in the tumor. The geometry simulated corresponds to a spherical nodule of densely packed tumor cells. Absorbed doses are calculated for radiation from a single nodule (e.g., a micrometastasis or prevascular primary tumor) and for a cubic lattice of such nodules (e.g., corresponding to nodular lymphoma). As noted in our previous studies, there is a "binding site barrier." Binding to antigen retards antibody percolation into the nodules; high antibody affinity tends to decrease percolation and give a higher absorbed dose near the surface of each nodule. Heterogeneous antibody distribution results in a heterogeneous absorbed dose. This is more apparent in the case of radiation from a single nodule than it is for radiation from within an array of nodules. Dehalogenation results in a lower absorbed dose over time, and the effect is more apparent at later times after injection. PERC-RAD, the computer program package developed for these analyses, provides a convenient and flexible way to assess the impact of macroscopic and microscopic parameters on the distribution of radioimmunoconjugates and on the consequent profile of absorbed radiation dose in tumors. This mathematical model and the general principles developed here can be applied as well to other radiolabeled biological ligands. C1 NCI, MATH BIOL LAB, BLDG 10, ROOM 4B-56, BETHESDA, MD 20892 USA. PACIFIC NW LAB, RICHLAND, WA 99352 USA. FU NCI NIH HHS [CA44991] NR 34 TC 38 Z9 38 U1 0 U2 0 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 SEP 15 PY 1991 VL 51 IS 18 BP 4821 EP 4827 PG 7 WC Oncology SC Oncology GA GE303 UT WOS:A1991GE30300012 PM 1893374 ER PT J AU HANSON, DL PORTER, JL WILLIAMS, RR AF HANSON, DL PORTER, JL WILLIAMS, RR TI HIGH-PURITY ION-BEAM PRODUCTION AT HIGH-CURRENT DENSITIES WITH A LIQUID-HELIUM-COOLED SERIES-FIELD-COIL EXTRACTION ION DIODE SO JOURNAL OF APPLIED PHYSICS LA English DT Article ID MOLECULAR-HYDROGEN; PBFA-II; DIAGNOSTICS; SIMULATION; CU(100); FUSION AB Experiments are described in which a high-purity, high-power (0.15 TW, 1 MeV) proton beam is generated from an ion source consisting of H2 gas frozen onto a liquid-helium-cooled copper anode at 4.2 K in a series-field-coil extraction diode on the 0.7 TW HydraMITE-II accelerator. Peak anode proton current densities of 2 kA/cm2 were measured. This current density is a factor of 100 higher than those obtained in previous liquid-helium-cooled cryogenic diode experiments on small accelerators and is in the range required for high-power ion beam applications. Thomson parabola, Faraday cup, and carbon activation measurements indicate an ion beam proton fraction close to 100% for the cryogenic source, compared to 50-70% for the standard hydrocarbon anode tested. The cryogenic proton source is believed to consist of no more than a few monolayers of molecular hydrogen. The hydrogen-coated cryogenic anode shows a faster initial anode turn-on than other materials. However, source-limited emission from the thin hydrogen layer results in a somewhat longer current risetime, reduced ion diode efficiency, lower proton current enhancement over the Child-Langmuir limit, and a proton spectrum of lower average energy than for the hydrocarbon anode. Techniques to overcome these limitations are discussed. Cryogenic ion sources consisting of frozen N2, CH4, and Ne have also been studied. In each case, high intensity beams consisting predominantly of components of the refrigerated gas were produced. RP HANSON, DL (reprint author), SANDIA NATL LABS,POB 5800,ALBUQUERQUE,NM 87185, USA. NR 44 TC 7 Z9 7 U1 2 U2 2 PU AMER INST PHYSICS PI WOODBURY PA CIRCULATION FULFILLMENT DIV, 500 SUNNYSIDE BLVD, WOODBURY, NY 11797-2999 SN 0021-8979 J9 J APPL PHYS JI J. Appl. Phys. PD SEP 15 PY 1991 VL 70 IS 6 BP 2926 EP 2938 DI 10.1063/1.349317 PG 13 WC Physics, Applied SC Physics GA GF539 UT WOS:A1991GF53900007 ER PT J AU SHIEH, SY EVANS, JW AF SHIEH, SY EVANS, JW TI THE STABILITY OF CYLINDRICAL VOIDS AND OF CYLINDERS SUBJECT TO CLOSURE BY VISCOUS-FLOW OR EVAPORATION CONDENSATION SO JOURNAL OF APPLIED PHYSICS LA English DT Article ID INSTABILITY AB The stability of a cylindrical pore in an infinite medium, or of an infinite cylinder, when surface energy is significant is considered. The growth of small sinusoidal perturbations by viscous flow (creeping flow) or by evaporation/condensation are examined. The principal results are the dependence of perturbation growth rate on perturbation wavelength. For the creeping flow case no maximum in perturbation growth rate appears. The results are compared with those of Lord Rayleigh [Philos. Mag. 34-207, 145 (1892)] and of Nichols and Mullins [Trans. AIME 233, 1840 (1965)]. C1 UNIV CALIF BERKELEY LAWRENCE BERKELEY LAB,DEPT MAT SCI & MINERAL ENGN,BERKELEY,CA 94720. RP SHIEH, SY (reprint author), UNIV CALIF BERKELEY LAWRENCE BERKELEY LAB,DIV MAT SCI,BERKELEY,CA 94720, USA. NR 7 TC 3 Z9 3 U1 1 U2 4 PU AMER INST PHYSICS PI WOODBURY PA CIRCULATION FULFILLMENT DIV, 500 SUNNYSIDE BLVD, WOODBURY, NY 11797-2999 SN 0021-8979 J9 J APPL PHYS JI J. Appl. Phys. PD SEP 15 PY 1991 VL 70 IS 6 BP 2968 EP 2972 DI 10.1063/1.349323 PG 5 WC Physics, Applied SC Physics GA GF539 UT WOS:A1991GF53900013 ER PT J AU GORBATKIN, SM ZUHR, RA ROTH, J NARAMOTO, H AF GORBATKIN, SM ZUHR, RA ROTH, J NARAMOTO, H TI DAMAGE FORMATION AND SUBSTITUTIONALITY IN AS-75++-IMPLANTED DIAMOND SO JOURNAL OF APPLIED PHYSICS LA English DT Article ID ION-IMPLANTED DIAMOND; IRRADIATION; SI AB Rutherford backscattering spectrometry (RBS) has been used to study damage formation and substitutionality in synthetic diamonds implanted with 250-keV As-75 + + at either 600-degrees-C or room temperature. Lattice damage following implantation at 600-degrees-C was substantially less than damage following room-temperature implantation and appears to be composed of a higher fraction of extended defects. A significant portion of the As implanted at 600-degrees-C was found to be in substitutional lattice sites with substitutional fractions as high as 50%. Changing the ion flux by three orders of magnitude during high-temperature implantation had no effect on either residual damage or substitutionality as indicated by the RBS analysis. C1 EURATOM,MAX PLANCK INST PLASMAPHYS,W-8046 GARCHING,GERMANY. JAPAN ATOM ENERGY RES INST,TOKAI,IBARAKI 31911,JAPAN. RP GORBATKIN, SM (reprint author), OAK RIDGE NATL LAB,DIV SOLID STATE,OAK RIDGE,TN 37831, USA. NR 18 TC 10 Z9 10 U1 0 U2 0 PU AMER INST PHYSICS PI WOODBURY PA CIRCULATION FULFILLMENT DIV, 500 SUNNYSIDE BLVD, WOODBURY, NY 11797-2999 SN 0021-8979 J9 J APPL PHYS JI J. Appl. Phys. PD SEP 15 PY 1991 VL 70 IS 6 BP 2986 EP 2990 DI 10.1063/1.349326 PG 5 WC Physics, Applied SC Physics GA GF539 UT WOS:A1991GF53900016 ER PT J AU SWENSON, CA AF SWENSON, CA TI HIP BERYLLIUM - THERMAL EXPANSIVITY FROM 4-K TO 300-K AND HEAT-CAPACITY FROM 1-K TO 108-K SO JOURNAL OF APPLIED PHYSICS LA English DT Article ID COPPER AB Linear thermal expansivity measurements from 4.2 to 302 K and heat capacity measurements from 4.6 to 108 K have been made on HIP (hot isostatic pressing) beryllium metal. The heat capacity data are in good agreement with previous data from 1.4 to 30 K for high purity single crystals. Our THETA-0 = 1485 (5) K also agrees well with that calculated from high-pressure elastic constant results. The linear thermal expansivity decreases rapidly with decreasing temperature from 1.13 x 10(-5) K-1 at 293 K, as would be expected for the large THETA-0, and becomes very small (< 10(-7) K-1) below 50 K. The expansivities below 108 K are consistent with a constant gamma-0-lat = 1.15 and with gamma-0-lat = 0.91 from the high-pressure elastic constant results. C1 IOWA STATE UNIV SCI & TECHNOL,DEPT PHYS,AMES,IA 50011. RP SWENSON, CA (reprint author), IOWA STATE UNIV SCI & TECHNOL,AMES LAB,AMES,IA 50011, USA. NR 13 TC 10 Z9 10 U1 0 U2 3 PU AMER INST PHYSICS PI WOODBURY PA CIRCULATION FULFILLMENT DIV, 500 SUNNYSIDE BLVD, WOODBURY, NY 11797-2999 SN 0021-8979 J9 J APPL PHYS JI J. Appl. Phys. PD SEP 15 PY 1991 VL 70 IS 6 BP 3046 EP 3051 DI 10.1063/1.349336 PG 6 WC Physics, Applied SC Physics GA GF539 UT WOS:A1991GF53900026 ER PT J AU SCHLESINGER, TE CAMMARATA, RC GAVRIN, A XIAO, JQ CHIEN, CL FERBER, MK HAYZELDEN, C AF SCHLESINGER, TE CAMMARATA, RC GAVRIN, A XIAO, JQ CHIEN, CL FERBER, MK HAYZELDEN, C TI ENHANCED MECHANICAL AND MAGNETIC-PROPERTIES OF GRANULAR METAL THIN-FILMS SO JOURNAL OF APPLIED PHYSICS LA English DT Article ID STRAIN AB The mechanical properties of Ag-Al2O3 and Ni-Al2O3 granular metal films, as well as the magnetic behavior of the nickel-based films, is presented. Enhancements in the mechanical properties of these materials, as measured by low load indentation techniques, were observed for a metal volume fraction p of about 0.55. This volume fraction corresponded to the percolation threshold p(c) as determined from the magnetic measurements. A peak in the compliance as a function of p was observed, similar to elastic anomalies reported for small bilayer period superlattices. A discontinuity in the rate of change of hardness as a function of p was also observed, and believed to result from a change in deformation mechanism at p(c). C1 JOHNS HOPKINS UNIV,DEPT PHYS & ASTRON,BALTIMORE,MD 21218. OAK RIDGE NATL LAB,HIGH TEMP MAT LAB,OAK RIDGE,TN 37831. HARVARD UNIV,DIV APPL SCI,CAMBRIDGE,MA 02138. RP SCHLESINGER, TE (reprint author), JOHNS HOPKINS UNIV,DEPT MAT SCI & ENGN,BALTIMORE,MD 21218, USA. RI Cammarata, Robert /A-3307-2010 NR 29 TC 17 Z9 17 U1 0 U2 2 PU AMER INST PHYSICS PI WOODBURY PA CIRCULATION FULFILLMENT DIV, 500 SUNNYSIDE BLVD, WOODBURY, NY 11797-2999 SN 0021-8979 J9 J APPL PHYS JI J. Appl. Phys. PD SEP 15 PY 1991 VL 70 IS 6 BP 3275 EP 3280 DI 10.1063/1.349286 PG 6 WC Physics, Applied SC Physics GA GF539 UT WOS:A1991GF53900059 ER PT J AU CARL, DA HESS, DW LIEBERMAN, MA NGUYEN, TD GRONSKY, R AF CARL, DA HESS, DW LIEBERMAN, MA NGUYEN, TD GRONSKY, R TI EFFECTS OF DC BIAS ON THE KINETICS AND ELECTRICAL-PROPERTIES OF SILICON DIOXIDE GROWN IN AN ELECTRON-CYCLOTRON RESONANCE PLASMA SO JOURNAL OF APPLIED PHYSICS LA English DT Article ID LOW-TEMPERATURE OXIDATION; MICROWAVE-INDUCED PLASMAS; GENERATED OXYGEN PLASMA; PRESSURE RANGE; 10 MTORR; FILMS; ANODIZATION; SIO2; MODEL AB Thin (3-300-nm) oxides were grown on single-crystal silicon substrates at temperatures from 523 to 673 K in a low-pressure electron cyclotron resonance (ECR) oxygen plasma. Oxides were grown under floating, anodic or cathodic bias conditions, although only the oxides grown under floating or anodic bias conditions are acceptable for use as gate dielectrics in metal-oxide-semiconductor technology. Oxide thickness uniformity as measured by ellipsometry decreased with increasing oxidation time for all bias conditions. Oxidation kinetics under anodic conditions can be explained by negatively charged atomic oxygen, O-, transport limited growth. Constant current anodizations yielded three regions of growth: (1) a concentration gradient dominated regime for oxides thinner than 10 nm, (2) a field dominated regime with ohmic charged oxidant transport for oxide thickness in the range of 10 nm to approximately 100 nm, and (3) a space-charge limited regime for films thicker than approximately 100 nm. The relationship between oxide thickness (chi(ox)), overall potential drop (V(ox)) and ion current (j(i)) in the space-charge limited transport region was of the form: j(i) proportional-to V2ox/chi(ox)3. Transmission electron microscopy analysis of 5-60-nm-thick anodized films indicated that the silicon-silicon dioxide interface was indistinguishable from that of thermal oxides grown at 1123 K. High-frequency capacitance-voltage (C-V) and ramped bias current-voltage (I-V) studies performed on 5.4-30-nm gate thickness capacitors indicated that the as-grown ECR films had high levels of fixed oxide charge (> 10(11) cm-2) and interface traps (> 10(12) cm-2 eV-1). The fixed charge level could be reduced to almost-equal-to 4 x 10(10) cm-2 by a 20 min polysilicon gate activation anneal at 1123 K in nitrogen; the interface trap density at mid-band gap decreased to almost-equal-to (1-2) x 10(11) cm-2 eV-1 after this process. The mean breakdown strength for anodic oxides grown under optimum conditions was 10.87 +/- 0.83 MV cm-1. Electrical properties of the 5.4-8-nm gates compared well with thicker films and control dry thermal oxides of similar thicknesses. C1 UNIV CALIF BERKELEY, DEPT CHEM ENGN, BERKELEY, CA 94720 USA. UNIV CALIF BERKELEY, DEPT ELECT ENGN & COMP SCI, BERKELEY, CA 94720 USA. UNIV CALIF BERKELEY LAWRENCE BERKELEY LAB, DEPT MAT SCI & MINERAL ENGN, CTR XRAY OPT, BERKELEY, CA 94720 USA. UNIV CALIF BERKELEY LAWRENCE BERKELEY LAB, NATL CTR ELECTRON MICROSCOPY, BERKELEY, CA 94720 USA. UNIV CALIF BERKELEY, DEPT MAT SCI & MINERAL ENGN, BERKELEY, CA 94720 USA. NR 38 TC 63 Z9 63 U1 0 U2 10 PU AMER INST PHYSICS PI MELVILLE PA 1305 WALT WHITMAN RD, STE 300, MELVILLE, NY 11747-4501 USA SN 0021-8979 EI 1089-7550 J9 J APPL PHYS JI J. Appl. Phys. PD SEP 15 PY 1991 VL 70 IS 6 BP 3301 EP 3313 DI 10.1063/1.349264 PG 13 WC Physics, Applied SC Physics GA GF539 UT WOS:A1991GF53900062 ER PT J AU MICHEL, H GRIFFIN, PR SHABANOWITZ, J HUNT, DF BENNETT, J AF MICHEL, H GRIFFIN, PR SHABANOWITZ, J HUNT, DF BENNETT, J TI TANDEM MASS-SPECTROMETRY IDENTIFIES SITES OF 3 POSTTRANSLATIONAL MODIFICATIONS OF SPINACH LIGHT-HARVESTING CHLOROPHYLL PROTEIN-II - PROTEOLYTIC CLEAVAGE, ACETYLATION, AND PHOSPHORYLATION SO JOURNAL OF BIOLOGICAL CHEMISTRY LA English DT Article ID A/B BINDING-PROTEIN; SUBSTRATE-SPECIFICITY; PHOTOSYSTEM-II; SYNTHETIC PEPTIDES; BASIC RESIDUES; THYLAKOID MEMBRANES; KINASE; COMPLEX; CHLOROPLASTS; POLYPEPTIDES AB The photosynthetic membranes of spinach (Spinacia oleracea L.) chloroplasts were incubated with [gamma-P-32] ATP. When the thylakoid membrane kinase was activated with light, the 25- and 27-kDa forms of the light-harvesting chlorophyll a/b protein (LHC II) were phosphorylated on their amino termini. Treatment of the membranes with proteinase K or thermolysin released phosphopeptides which were purified by ferric ion affinity chromatography and reverse phase high performance liquid chromatography. Sequencing of the phosphopeptides was performed with tandem quadrupole mass spectrometry. Three different phosphopeptides Ac-RKTAGKPKT, Ac-RKTAGKPKN, and Ac-RKSAGKPKN originating from class I LHC II were examined after release by thermolysin. One phosphopeptide, Ac-RRTVKSAPQ, originating from class II LHC II was examined after release by proteinase K. Each of the four LHC II phosphopeptides was derived from the amino terminus of a distinct protein. Peptides were acetylated at their amino-terminal arginine and were phosphorylated on either threonine or serine in the third position. We conclude that proteolytic processing of pre-LHC II occurs at a conserved methionylarginyl bond and is followed by amino-terminal acetylation of the arginine and nearby phosphorylation of the mature LHC II. Eight different peptides were synthesized in acetylated and nonacetylated forms as substrates for the thylakoid membrane kinase. From a comparison of the kinetics of phosphate incorporation into the peptides, we conclude that basic residues on both sides of the phosphorylation site are important for enzyme recognition. Acetylation of the amino terminus is not required for phosphorylation. C1 BROOKHAVEN NATL LAB,DEPT BIOL,UPTON,NY 11973. RP MICHEL, H (reprint author), UNIV VIRGINIA,DEPT CHEM,CHARLOTTESVILLE,VA 22901, USA. RI Hunt, Donald/I-6936-2012 OI Hunt, Donald/0000-0003-2815-6368 NR 35 TC 76 Z9 85 U1 0 U2 2 PU AMER SOC BIOCHEMISTRY MOLECULAR BIOLOGY INC PI BETHESDA PA 9650 ROCKVILLE PIKE, BETHESDA, MD 20814 SN 0021-9258 J9 J BIOL CHEM JI J. Biol. Chem. PD SEP 15 PY 1991 VL 266 IS 26 BP 17584 EP 17591 PG 8 WC Biochemistry & Molecular Biology SC Biochemistry & Molecular Biology GA GF445 UT WOS:A1991GF44500090 PM 1894641 ER PT J AU BUTENHOFF, TJ ROHLFING, EA AF BUTENHOFF, TJ ROHLFING, EA TI THE C3-PI-X3-PI BAND SYSTEM OF THE SIC RADICAL SO JOURNAL OF CHEMICAL PHYSICS LA English DT Article ID SPECTROSCOPY; TRANSITION; MOLECULE; STATES AB We report a study of the C 3-PI-X 3-PI band system of the SiC radical. Jet-cooled SiC is produced by a laser vaporization/pulsed beam source and is probed by pulsed laser-induced fluorescence excitation spectroscopy. Vibrational term energies and rotational constants are determined for upsilon' = 0-8 of the C state and for upsilon" = 0-5 of the X state. The spectroscopic constants for the C state are T(e) = 22 830.4(9) cm-1, omega-e = 615.7(8) cm-1, and r(e) = 1.919(3) angstrom; for the X state, omega-e = 965.16(24) cm-1 and r(e) = 1.7182(2) angstrom. RP BUTENHOFF, TJ (reprint author), SANDIA NATL LABS,COMBUST RES FACIL,LIVERMORE,CA 94551, USA. NR 19 TC 32 Z9 34 U1 1 U2 6 PU AMER INST PHYSICS PI WOODBURY PA CIRCULATION FULFILLMENT DIV, 500 SUNNYSIDE BLVD, WOODBURY, NY 11797-2999 SN 0021-9606 J9 J CHEM PHYS JI J. Chem. Phys. PD SEP 15 PY 1991 VL 95 IS 6 BP 3939 EP 3943 DI 10.1063/1.460800 PG 5 WC Chemistry, Physical; Physics, Atomic, Molecular & Chemical SC Chemistry; Physics GA GF099 UT WOS:A1991GF09900008 ER PT J AU ZHANG, JZ HARRIS, CB AF ZHANG, JZ HARRIS, CB TI PHOTODISSOCIATION DYNAMICS OF MN2 (CO)10 IN SOLUTION ON ULTRAFAST TIME SCALES SO JOURNAL OF CHEMICAL PHYSICS LA English DT Article ID METAL-METAL BONDS; DIMANGANESE DECACARBONYL; PHOTOGENERATED CR(CO)5(ROH); PHOTO-DISSOCIATION; CHEMICAL-REACTIONS; LASER PHOTOLYSIS; CONDENSED PHASE; CARBON-MONOXIDE; COMPLEXES; MN2(CO)10 AB A study of the photodissociation dynamics of Mn2 (CO)10 and the vibrational relaxation of its subsequent photoproducts in solutions has been carried out using picosecond time-resolved laser techniques. The molecule predissociates in less than 2-3 ps after excitation with a 295 nm photon. Two dissociation channels are open for this excitation wavelength, namely, the Mn-Mn bond breaking and the Mn-CO bond breaking, generating internally hot.Mn(CO)5 and Mn2 (CO)9, respectively. These two species have a different absorption spectrum in the visible region and are probed independently by varying the probe laser wavelength. The vibrational relaxation of these nascent photoproducts is observed for the first time. In cyclohexane the vibrationally hot Mn2 (CO)9 reaches thermal equilibrium with the solvent through two distinct decay channels with time constants of 15 and 170 ps, respectively. The vibrationally cold Mn2(CO)9 then persists for many nanoseconds. The vibrational relaxation is found to be faster in the 2-propanol solution with time constants of 10 and 145 ps. On the other hand, the .Mn(CO)5 species cools down in less than 10 ps and then exists in the solution for many nanoseconds as well. This result indicates that energy transfer from the internally hot .Mn(CO)5 species to the solvent is much faster than from Mn2 (CO)9. Comparison is made with Cr(CO)5 in similar solvents. C1 UNIV CALIF BERKELEY LAWRENCE BERKELEY LAB,DIV CHEM SCI,BERKELEY,CA 94720. RP ZHANG, JZ (reprint author), UNIV CALIF BERKELEY,DEPT CHEM,BERKELEY,CA 94720, USA. NR 40 TC 40 Z9 40 U1 2 U2 8 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 SEP 15 PY 1991 VL 95 IS 6 BP 4024 EP 4032 DI 10.1063/1.460757 PG 9 WC Chemistry, Physical; Physics, Atomic, Molecular & Chemical SC Chemistry; Physics GA GF099 UT WOS:A1991GF09900017 ER PT J AU RUSCIC, B BERKOWITZ, J AF RUSCIC, B BERKOWITZ, J TI PHOTOIONIZATION MASS-SPECTROMETRIC STUDIES OF THE ISOMERIC TRANSIENT SPECIES CD2OH AND CD3O SO JOURNAL OF CHEMICAL PHYSICS LA English DT Article ID MULTIPHOTON IONIZATION SPECTROSCOPY; BOND-DISSOCIATION ENERGIES; GAS-PHASE; PHOTOELECTRON-SPECTROSCOPY; METHOXY; CH3O; SPECTRUM; STATE; IONS; PHOTODISSOCIATION AB Both CD2OH and CD3O were prepared in situ by the reaction of F atoms with CD3OH, and studied by photoionization mass spectrometry. The adiabatic ionization potential (I.P.) of CD2OH was found to be 7.540 +/- 0.006 eV, in good agreement with the photoelectron spectroscopy (PES) value, 7.55 +/- 0.01 eV. However, the adiabatic I.P. of CD3O was determined to be 10.726 +/- 0.008 eV, in marked contrast to the PES value for CH3O, 7.37 +/- 0.03 eV, but in the expected range based on reported values of DELTA-H(f)o(CH3O+) and DELTA-H(f)0(CH3O). From selected values of DELTA-H(f0)0(CH2OH+) less-than-or-equal-to 172.0 +/- 0.7 kcal/mol and DELTA-H(f0)0 (CH3O) = 5.9 +/- 1.0 kcal/mol, we deduce DELTA-H(f0)0 (CH2OH) less-than-or-equal-to - 2.1 +/- 0.7 kcal/mol and DELTA-H(f0)0 (CH3O+) = 253.1 +/- 1.0 kcal/mol. RP RUSCIC, B (reprint author), ARGONNE NATL LAB,DIV CHEM,ARGONNE,IL 60439, USA. RI Ruscic, Branko/A-8716-2008 OI Ruscic, Branko/0000-0002-4372-6990 NR 52 TC 75 Z9 76 U1 1 U2 5 PU AMER INST PHYSICS PI WOODBURY PA CIRCULATION FULFILLMENT DIV, 500 SUNNYSIDE BLVD, WOODBURY, NY 11797-2999 SN 0021-9606 J9 J CHEM PHYS JI J. Chem. Phys. PD SEP 15 PY 1991 VL 95 IS 6 BP 4033 EP 4039 DI 10.1063/1.460758 PG 7 WC Chemistry, Physical; Physics, Atomic, Molecular & Chemical SC Chemistry; Physics GA GF099 UT WOS:A1991GF09900018 ER PT J AU CURTISS, LA KOCK, LD POPLE, JA AF CURTISS, LA KOCK, LD POPLE, JA TI ENERGIES OF CH2OH, CH3O, AND RELATED-COMPOUNDS SO JOURNAL OF CHEMICAL PHYSICS LA English DT Article ID ALKYL NITRITES RONO; DISSOCIATION-ENERGIES; METHOXY; PYROLYSIS; MOLECULES; HEATS; IONS AB The Gaussian-2 (G2) theoretical procedure, based on ab initio molecular orbital theory, is used to calculate the energies of CH2OH, CH3O, and their cations. The resulting G2 adiabatic ionization potential for CH3O of 10.78 eV supports the new value of 10.726 +/- 0.008 eV reported by Ruscic and Berkowitz [J. Chem. Phys. 95, 4033 (1991)] from a photoionization study. A previous photoelectron result of 7.37 +/- 0.03 eV is probably an incorrect assignment. The G2 ionization potential for CH2OH is 7.45 eV, consistent with the experimental value of 7.55 eV. The calculated O-H and C-H bond dissociation energies of CH3OH are 105.0 and 96.2 kcal/mol, respectively. The results suggest that the D0(H-CH2OH) from kinetics measurements may be too low. C1 CARNEGIE MELLON UNIV,DEPT CHEM,PITTSBURGH,PA 15213. RP CURTISS, LA (reprint author), ARGONNE NATL LAB,DIV MAT SCI,DIV CHEM TECHNOL,ARGONNE,IL 60439, USA. NR 27 TC 120 Z9 121 U1 2 U2 5 PU AMER INST PHYSICS PI WOODBURY PA CIRCULATION FULFILLMENT DIV, 500 SUNNYSIDE BLVD, WOODBURY, NY 11797-2999 SN 0021-9606 J9 J CHEM PHYS JI J. Chem. Phys. PD SEP 15 PY 1991 VL 95 IS 6 BP 4040 EP 4043 DI 10.1063/1.460759 PG 4 WC Chemistry, Physical; Physics, Atomic, Molecular & Chemical SC Chemistry; Physics GA GF099 UT WOS:A1991GF09900019 ER PT J AU LOVEJOY, ER KIM, SK ALVAREZ, RA MOORE, CB AF LOVEJOY, ER KIM, SK ALVAREZ, RA MOORE, CB TI KINETICS OF INTRAMOLECULAR CARBON-ATOM EXCHANGE IN KETENE SO JOURNAL OF CHEMICAL PHYSICS LA English DT Article ID LASER-INDUCED FLUORESCENCE; ELECTRONIC STATES; RATE CONSTANTS; OXIRENE INTERMEDIATE; PHOTOFRAGMENTATION; REARRANGEMENT; DISSOCIATION; CH2(X3B1); ABINITIO; CO AB Intramolecular carbon atom exchange in highly vibrationally excited ketene was studied by monitoring the carbon monoxide fragments (CO)-C-12 and (CO)-C-13 from the photodissociation of (CH2)-C-12 (CO)-C-13 and (CH2)-C-13 (CO)-C-12. Two experimental techniques were employed. In one set of experiments the IR transient absorptions of (CO)-C-12 and (CO)-C-13 were measured following pulsed excimer excitation of ketene C-13 isotopomers, giving carbon atom exchange yields at 351 and 308 nm in a low pressure gas cell. In the other set of experiments, jet-cooled ketene C-13 isotopomers were excited with tunable near-UV radiation, and the CO products were detected by monitoring their VUV laser-induced fluorescence. Carbon atom exchange yields were measured for energies extending from below the triplet decomposition threshold (CH2CO --> CH2 (X 3B1) + CO(X 1-SIGMA+)) to about 4000 cm-1 above the singlet threshold (CH2CO --> CH2 (a 1A1) + CO(X 1-SIGMA+)). The exchange yields range from 4 to 19%, and the energy dependence of the yield exhibits pronounced structure, with maxima at the triplet and singlet decomposition thresholds. Kinetic measurements of the appearance of the CO products were also performed. The time constant for the appearance of the exchanged CO (e.g., (CO)-C-13 from (CH2)-C-13 (CO)-C-12) is significantly longer than that for the direct CO fragment (e.g., (CO)-C-12 from (CH2)-C-13 (CO)-C-12). All the experimental observations are consistent with a simple reaction mechanism involving ketene isomerization, (CH2)-C-13 (CO)-C-12 reversible (CH2)-C-12 (CO)-C-13, and dissociation, (CH2)-C-13 (CO)-C-12 --> (CH2)-C-13 + (CO)-C-12 and (CH2)-C-12 (CO)-C-13 --> (CH2)-C-12 + (CO)-C-13. The isomerization rate was determined by analyzing the CO kinetics and the carbon atom exchange yields in terms of the simple isomerization mechanism. A fit of the energy dependence of the isomerization rate constant to the results of tunneling-corrected Rice-Ramsberger-Kassel-Marcus (RRKM) calculations gave the threshold (28360 +/- 60 cm-1) for the isomerization process. C1 UNIV CALIF BERKELEY LAWRENCE BERKELEY LAB,DIV MAT & CHEM SCI,BERKELEY,CA 94720. RP LOVEJOY, ER (reprint author), UNIV CALIF BERKELEY,DEPT CHEM,BERKELEY,CA 94720, USA. RI Kim, Sang Kyu/C-1613-2011 NR 38 TC 29 Z9 29 U1 1 U2 3 PU AMER INST PHYSICS PI WOODBURY PA CIRCULATION FULFILLMENT DIV, 500 SUNNYSIDE BLVD, WOODBURY, NY 11797-2999 SN 0021-9606 J9 J CHEM PHYS JI J. Chem. Phys. PD SEP 15 PY 1991 VL 95 IS 6 BP 4081 EP 4093 DI 10.1063/1.460764 PG 13 WC Chemistry, Physical; Physics, Atomic, Molecular & Chemical SC Chemistry; Physics GA GF099 UT WOS:A1991GF09900024 ER PT J AU RUSCIC, B BERKOWITZ, J AF RUSCIC, B BERKOWITZ, J TI PHOTOIONIZATION MASS-SPECTROMETRIC STUDY OF N2H2 AND N2H3-N-H, N=N BOND-ENERGIES AND PROTON AFFINITY OF N2 SO JOURNAL OF CHEMICAL PHYSICS LA English DT Article ID INFRARED-LASER SPECTROSCOPY; FUNDAMENTAL BANDS; DIIMIDE; MOLECULES; HEAT; N-2; MECHANISMS; IONIZATION; NITROGEN; SPECTRA AB The photoion yield curves of N2H2+, N2H+, and H2+ from N2H2 have been studied by photoionization mass spectrometry. The adiabatic ionization potential of N2H2 determined (9.589 +/- 0.007 eV) is in excellent agreement with that obtained by photoelectron spectroscopy (PES). The appearance potential of N2H+ (10.954 +/- 0.019 eV at 0 K) is in good agreement with earlier electron impact measurements. The appearance potential of H-2+ (< 13.52(6) +/- 0.03; probably less-than-or-equal-to 13.403 +/- 0.036 eV, at 0 K) leads to DELTA-H(fo)0 (N2H2) > 43.8 +/- 0.7; probably greater-than-or-equal-to 46.6 +/- 0.8 kcal/mol. Consequently, proton affinity (PA) (N2) < 121.8 +/- 0.8; probably less-than-or-equal-to 119.0 +/- 0.9 kcal/mol, which is in good agreement with results from proton transfer experiments and with most ab initio calculations. The N = N "double bond" energy determined from N2H2 --> 2NH is < 126.6 +/- 1.0; probably less-than-or-equal-to 123.8 +/- 1.1 kcal/mol. The adiabatic ionization potential of N2H3 is found to be 7.61 +/- 0.01 eV. This observation leads to D0 (H2NNH-H) = 80.8 +/- 0.3 kcal/mol, and D0(HNNH-H) congruent-to 43.8 +/- 1.1 kcal/mol. RP ARGONNE NATL LAB, DIV CHEM, ARGONNE, IL 60439 USA. RI Ruscic, Branko/A-8716-2008 OI Ruscic, Branko/0000-0002-4372-6990 NR 36 TC 56 Z9 56 U1 1 U2 9 PU AMER INST PHYSICS PI MELVILLE PA 1305 WALT WHITMAN RD, STE 300, MELVILLE, NY 11747-4501 USA SN 0021-9606 EI 1089-7690 J9 J CHEM PHYS JI J. Chem. Phys. PD SEP 15 PY 1991 VL 95 IS 6 BP 4378 EP 4384 DI 10.1063/1.461761 PG 7 WC Chemistry, Physical; Physics, Atomic, Molecular & Chemical SC Chemistry; Physics GA GF099 UT WOS:A1991GF09900055 ER PT J AU POPLE, JA CURTISS, LA AF POPLE, JA CURTISS, LA TI THE ENERGY OF N2H2 AND RELATED-COMPOUNDS SO JOURNAL OF CHEMICAL PHYSICS LA English DT Article ID THEORETICAL CHARACTERIZATION; SURFACE; ABINITIO; DIAZENE; DIIMIDE; N-2 AB Ab initio molecular orbital theory at the G2 level has been used to study the energy of N2H2 and related compounds. Overall, the agreement between theory and experiment is good. The G2 enthalpy of formation DELTA-H(f0)0 (N2H2) of 49.6 kcal/mol supports the experimental estimate of greater-than-or-equal-to 46.6 kcal/mol derived by Ruscic and Berkowitz [J. Chem. Phys. 95, 4378 (1991)] in a recent photoionization study. Predicted dissociation energies are D0(HN = NH) = 122.8 kcal/mol, D0(HNNH-H) = 43.6 kcal/mol, and D0(H2N = NH-H) = 82.1 kcal/mol. The G2 value for the proton affinity (PA) of N2 at 298 K is PA298 = 118.1 kcal/mol. The G2 ionization potential of N2H3 of 7.54 eV is in agreement with the new value of less-than-or-equal-to 7.61 eV reported by Ruscic and Berkowitz. The G2 results for the ionization potential of N2H4 and the appearance potential of N2+ from N2H2 are in disagreement with experimental results suggesting that detection of the origins in these cases are thwarted by large geometry changes and significant Franck-Condon effects. C1 ARGONNE NATL LAB,DIV CHEM TECHNOL,ARGONNE,IL 60439. ARGONNE NATL LAB,DIV MAT SCI,ARGONNE,IL 60439. RP POPLE, JA (reprint author), CARNEGIE MELLON UNIV,DEPT CHEM,PITTSBURGH,PA 15213, USA. NR 21 TC 97 Z9 97 U1 3 U2 12 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 SEP 15 PY 1991 VL 95 IS 6 BP 4385 EP 4388 DI 10.1063/1.461762 PG 4 WC Chemistry, Physical; Physics, Atomic, Molecular & Chemical SC Chemistry; Physics GA GF099 UT WOS:A1991GF09900056 ER PT J AU VOGEL, V MULLIN, CS SHEN, YR KIM, MW AF VOGEL, V MULLIN, CS SHEN, YR KIM, MW TI SURFACE-DENSITY OF SOLUBLE SURFACTANTS AT THE AIR-WATER-INTERFACE - ADSORPTION EQUILIBRIUM STUDIED BY 2ND HARMONIC-GENERATION SO JOURNAL OF CHEMICAL PHYSICS LA English DT Article ID SODIUM DODECYLSULFATE; ACTIVE SUBSTANCE; AQUEOUS SURFACE; RADIOTRACER; MOLECULES; KINETICS AB Optical second harmonic generation is employed to investigate the adsorption of soluble naphthalene sulfonates from the bulk solution to the air/water interface in the presence of excess counter ions. Both the surface density of surfactant molecules and the surface pressure were measured as functions of surfactant concentration in solution to yield the adsorption isotherm and the surface pressure/area isotherm. The system investigated shows nonideal gas behavior. The ratio of the activity coefficients at the surface and in the bulk is not unity; however both appear to be constant over the concentration range probed. C1 EXXON RES & ENGN CO,ANNANDALE,NJ 08801. UNIV WASHINGTON,CTR BIOENGN,SEATTLE,WA 98195. RP VOGEL, V (reprint author), UNIV CALIF BERKELEY LAWRENCE BERKELEY LAB,DEPT PHYS,CTR ADV MAT,BERKELEY,CA 94720, USA. RI Kim, Mahn Won/C-1541-2011; Vogel, Viola/O-8025-2015 OI Vogel, Viola/0000-0003-2898-7671 NR 21 TC 25 Z9 25 U1 1 U2 6 PU AMER INST PHYSICS PI WOODBURY PA CIRCULATION FULFILLMENT DIV, 500 SUNNYSIDE BLVD, WOODBURY, NY 11797-2999 SN 0021-9606 J9 J CHEM PHYS JI J. Chem. Phys. PD SEP 15 PY 1991 VL 95 IS 6 BP 4620 EP 4625 DI 10.1063/1.461730 PG 6 WC Chemistry, Physical; Physics, Atomic, Molecular & Chemical SC Chemistry; Physics GA GF099 UT WOS:A1991GF09900080 ER PT J AU SHARAFEDDIN, OA BOWEN, HF KOURI, DJ DAS, S TANNOR, DJ HOFFMAN, DK AF SHARAFEDDIN, OA BOWEN, HF KOURI, DJ DAS, S TANNOR, DJ HOFFMAN, DK TI TIME-DEPENDENT QUANTUM-MECHANICS USING PICOSECOND TIME STEPS - APPLICATION TO PREDISSOCIATION OF HEI2 - COMMENT SO JOURNAL OF CHEMICAL PHYSICS LA English DT Letter ID FOURIER METHOD SOLUTION; SCHRODINGER-EQUATION; SCATTERING C1 STEVENS INST TECHNOL LIB,DEPT CHEM,HOBOKEN,NJ 07030. UNIV NOTRE DAME,DEPT CHEM,NOTRE DAME,IN 46556. IOWA STATE UNIV SCI & TECHNOL,DEPT CHEM,AMES,IA 50011. IOWA STATE UNIV SCI & TECHNOL,AMES LAB,AMES,IA 50011. UNIV HOUSTON,DEPT PHYS,HOUSTON,TX 77204. RP SHARAFEDDIN, OA (reprint author), UNIV HOUSTON,DEPT CHEM,HOUSTON,TX 77204, USA. NR 11 TC 4 Z9 4 U1 0 U2 0 PU AMER INST PHYSICS PI WOODBURY PA CIRCULATION FULFILLMENT DIV, 500 SUNNYSIDE BLVD, WOODBURY, NY 11797-2999 SN 0021-9606 J9 J CHEM PHYS JI J. Chem. Phys. PD SEP 15 PY 1991 VL 95 IS 6 BP 4727 EP 4728 DI 10.1063/1.461748 PG 2 WC Chemistry, Physical; Physics, Atomic, Molecular & Chemical SC Chemistry; Physics GA GF099 UT WOS:A1991GF09900097 ER PT J AU HAGAN, PS OCKENDON, JR AF HAGAN, PS OCKENDON, JR TI HALF-RANGE ANALYSIS OF A COUNTERCURRENT SEPARATOR SO JOURNAL OF MATHEMATICAL ANALYSIS AND APPLICATIONS LA English DT Article C1 UNIV OXFORD, INST MATH, OXFORD OX1 3LB, ENGLAND. RP HAGAN, PS (reprint author), UNIV CALIF LOS ALAMOS SCI LAB, COMP RES GRP, LOS ALAMOS, NM 87545 USA. NR 10 TC 10 Z9 10 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 0022-247X J9 J MATH ANAL APPL JI J. Math. Anal. Appl. PD SEP 15 PY 1991 VL 160 IS 2 BP 358 EP 378 DI 10.1016/0022-247X(91)90311-M PG 21 WC Mathematics, Applied; Mathematics SC Mathematics GA GH628 UT WOS:A1991GH62800005 ER PT J AU BERZ, M FAWLEY, WM HAHN, K AF BERZ, M FAWLEY, WM HAHN, K TI HIGH-ORDER CALCULATION OF THE MULTIPOLE CONTENT OF 3-DIMENSIONAL ELECTROSTATIC GEOMETRIES SO NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH SECTION A-ACCELERATORS SPECTROMETERS DETECTORS AND ASSOCIATED EQUIPMENT LA English DT Article ID CHARGE AB We present an accurate and simple method of 3-D multipole decomposition of the field of arbitrary electrode geometries. The induced charge on the surface is obtained by inverting the capacity matrix. The multipole moment decomposition of the resulting potential is readily accomplished using differential algebra methodology. The method is applied to the focussing lattice geometry of the MBE-4 accelerator at LBL. Multipole terms of up to the order 5 are computed, and a numerical accuracy of < 1% is obtained. The effective quadrupole and dodecapole field strength are in good agreement with previous results. C1 UNIV CALIF BERKELEY LAWRENCE BERKELEY LAB,BERKELEY,CA 94720. NR 10 TC 11 Z9 11 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 SEP 15 PY 1991 VL 307 IS 1 BP 1 EP 6 DI 10.1016/0168-9002(91)90125-A PG 6 WC Instruments & Instrumentation; Nuclear Science & Technology; Physics, Nuclear; Physics, Particles & Fields SC Instruments & Instrumentation; Nuclear Science & Technology; Physics GA GE854 UT WOS:A1991GE85400001 ER PT J AU BERDOZ, AR BIRCHALL, J CAMPBELL, JR DAVIS, CA DAVISON, NE GREEN, PW KNOLL, M KORKMAZ, E MISCHKE, RE MOSSCROP, DR PAGE, SA RAMSAY, WD ROY, G SEKULOVICH, AM SOUKUP, J STINSON, GM STEWART, J VANOERS, WTH AF BERDOZ, AR BIRCHALL, J CAMPBELL, JR DAVIS, CA DAVISON, NE GREEN, PW KNOLL, M KORKMAZ, E MISCHKE, RE MOSSCROP, DR PAGE, SA RAMSAY, WD ROY, G SEKULOVICH, AM SOUKUP, J STINSON, GM STEWART, J VANOERS, WTH TI A BEAM INTENSITY PROFILE MONITOR BASED ON SECONDARY-ELECTRON EMISSION SO NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH SECTION A-ACCELERATORS SPECTROMETERS DETECTORS AND ASSOCIATED EQUIPMENT LA English DT Article AB Two dual function intensity profile monitors have been designed for a measurement of parity violation in right arrow over p-p scattering at about 230 MeV using longitudinally polarized protons. Each device contains a set of split secondary electron emission (SEM) foils to determine the median of the beam current distribution (in x and y). The split foils, coupled through servoamplifiers and operational amplifiers to upstream aircore steering magnets, have demonstrated the ability to hold the beam position stable to +/- 5-mu-m for beam position fluctuations up to 1000 Hz. These monitors also contain a set of foil strip planes giving information on the intensity distribution projected onto the two orthogonal axes, x and y. Data were acquired using 0.008 mm thick, 0.90 mm wide aluminum foil strips at 1.00 mm centers. The foil strip planes were able to determine the beam centroid to within +/- 3-mu-m after one hour of data taking with a 100 nA, 15 mm FWHM Gaussian beam. C1 UNIV ALBERTA,DEPT PHYS,EDMONTON T6G 2N5,ALBERTA,CANADA. TRIUMF,VANCOUVER V6T 2A3,BC,CANADA. UNIV CALIF LOS ALAMOS SCI LAB,LOS ALAMOS,NM 87545. RP BERDOZ, AR (reprint author), UNIV MANITOBA,DEPT PHYS,WINNIPEG R3T 2N2,MANITOBA,CANADA. NR 17 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 SEP 15 PY 1991 VL 307 IS 1 BP 26 EP 34 DI 10.1016/0168-9002(91)90127-C PG 9 WC Instruments & Instrumentation; Nuclear Science & Technology; Physics, Nuclear; Physics, Particles & Fields SC Instruments & Instrumentation; Nuclear Science & Technology; Physics GA GE854 UT WOS:A1991GE85400003 ER PT J AU BROSS, AD PLADALMAU, A BAUMBAUGH, B GODFREY, J JAQUES, J MARCHANT, J PIEKARZ, J RUCHTI, R AF BROSS, AD PLADALMAU, A BAUMBAUGH, B GODFREY, J JAQUES, J MARCHANT, J PIEKARZ, J RUCHTI, R TI DEVELOPMENT AND CHARACTERIZATION OF NEW SCINTILLATION MATERIALS FOR FIBER TRACKING AND CALORIMETRY SO NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH SECTION A-ACCELERATORS SPECTROMETERS DETECTORS AND ASSOCIATED EQUIPMENT LA English DT Article ID PLASTIC SCINTILLATORS AB Several polystyrene-based scintillators have been prepared in the Chemistry Facility of Fermi National Accelerator Laboratory and their light yield, fluorescence, and transmittance have been studied. In addition, emission time distributions were measured and the decay time constants were determined. A radiation damage study was performed in which the samples were irradiated to a total dose of 10 The. After annealing, the intrinsic light yield of the most radiation-hard scintillators had not changed significantly. C1 UNIV NOTRE DAME,NOTRE DAME,IN 46556. RP BROSS, AD (reprint author), FERMI NATL ACCELERATOR LAB,PARTICLE DETECTOR GRP,POB 500,BATAVIA,IL 60510, USA. NR 13 TC 12 Z9 12 U1 0 U2 0 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0168-9002 J9 NUCL INSTRUM METH A JI Nucl. Instrum. Methods Phys. Res. Sect. A-Accel. Spectrom. Dect. Assoc. Equip. PD SEP 15 PY 1991 VL 307 IS 1 BP 35 EP 46 DI 10.1016/0168-9002(91)90128-D PG 12 WC Instruments & Instrumentation; Nuclear Science & Technology; Physics, Nuclear; Physics, Particles & Fields SC Instruments & Instrumentation; Nuclear Science & Technology; Physics GA GE854 UT WOS:A1991GE85400004 ER PT J AU SULLIVAN, A HAMSTER, H KAPTEYN, HC GORDON, S WHITE, W NATHEL, H BLAIR, RJ FALCONE, RW AF SULLIVAN, A HAMSTER, H KAPTEYN, HC GORDON, S WHITE, W NATHEL, H BLAIR, RJ FALCONE, RW TI MULTITERAWATT, 100-FS LASER SO OPTICS LETTERS LA English DT Article ID CHIRPED-PULSE AMPLIFICATION; HIGH-POWER; SYSTEM; PERFORMANCE; IONIZATION AB Ultrashort-duration, high-energy laser pulses have been generated using a titanium-doped-sapphire oscillator and amplifier system. The pulses have an energy of 0.45 J with a duration of 95 fs and an energy of 0.23 J with a duration of 60 fs. C1 UNIV CALIF LAWRENCE LIVERMORE NATL LAB,LIVERMORE,CA 94550. SPARTA LASER SYST,SAN DIEGO,CA 92121. RP SULLIVAN, A (reprint author), UNIV CALIF BERKELEY,DEPT PHYS,BERKELEY,CA 94720, USA. RI Kapteyn, Henry/H-6559-2011 OI Kapteyn, Henry/0000-0001-8386-6317 NR 26 TC 116 Z9 116 U1 3 U2 10 PU OPTICAL SOC AMER PI WASHINGTON PA 2010 MASSACHUSETTS AVE NW, WASHINGTON, DC 20036 SN 0146-9592 J9 OPT LETT JI Opt. Lett. PD SEP 15 PY 1991 VL 16 IS 18 BP 1406 EP 1408 DI 10.1364/OL.16.001406 PG 3 WC Optics SC Optics GA GF631 UT WOS:A1991GF63100014 PM 19776984 ER PT J AU BIRGENEAU, RJ AHARONY, A COWLEY, RA HILL, JP PELCOVITS, RA SHIRANE, G THURSTON, TR AF BIRGENEAU, RJ AHARONY, A COWLEY, RA HILL, JP PELCOVITS, RA SHIRANE, G THURSTON, TR TI EFFECTS OF RANDOM-FIELDS ON BICRITICAL PHASE-DIAGRAMS IN 2 AND 3 DIMENSIONS SO PHYSICA A LA English DT Article ID + EPSILON-DIMENSIONS; TETRACRITICAL POINTS; SPIN-FLOP; ISING SYSTEMS; TRANSITIONS; METASTABILITY; BEHAVIOR AB Stimulated by the pioneering work of Michael Fisher and collaborators on bicritical phase diagrams in pure systems, we consider the corresponding behavior in systems with uniaxial random fields. We discuss experiments in the two- and three-dimensional n = 3 systems Rb2Mn0.7Mg0.3F4 and Mn0.75Zn0.25F2, respectively. We also report a new theory for the 2D n = 3 system, which predicts a novel phase boundary geometry. In both two and three dimensions the Ising component is dominated by metastability effects. However, the XY component shows a reversible transition to long range order. Experiments in the bicritical region in Mn0.75Zn0.25F2 are inconclusive. However, the theory describes the measured XY phase boundary in Rb2Mn0.7Mg0.3F4 quite well. C1 TEL AVIV UNIV,SCH PHYS & ASTRON,IL-69978 TEL AVIV,ISRAEL. BROOKHAVEN NATL LAB,DEPT PHYS,UPTON,NY 11973. BROWN UNIV,DEPT PHYS,PROVIDENCE,RI 02912. RP BIRGENEAU, RJ (reprint author), MIT,DEPT PHYS,CAMBRIDGE,MA 02139, USA. RI Hill, John/F-6549-2011 NR 29 TC 3 Z9 3 U1 0 U2 0 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0378-4371 J9 PHYSICA A JI Physica A PD SEP 15 PY 1991 VL 177 IS 1-3 BP 58 EP 66 DI 10.1016/0378-4371(91)90134-X PG 9 WC Physics, Multidisciplinary SC Physics GA GJ927 UT WOS:A1991GJ92700009 ER PT J AU BAKER, GA SINGH, RRP AF BAKER, GA SINGH, RRP TI BULK VALUE OF THE CENTRAL CHARGE IN CONFORMALLY INVARIANT CRITICAL PHENOMENA SO PHYSICA A LA English DT Article AB The concept of the central charge in a two-dimensional conformally invariant critical system is discussed. It is shown how this concept is related to a hyperuniversal amplitude ratio. In turn we illustrate the computation of its value by means of high-temperature series expansions for the cases of the Ising model and the three-state Potts model. The results are quite satisfactory and agree with the known results in these sample cases. C1 UNIV CALIF DAVIS,DEPT PHYS,DAVIS,CA 95616. RP BAKER, GA (reprint author), UNIV CALIF LOS ALAMOS SCI LAB,DIV THEORET,LOS ALAMOS,NM 87544, USA. NR 10 TC 4 Z9 4 U1 0 U2 0 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0378-4371 J9 PHYSICA A JI Physica A PD SEP 15 PY 1991 VL 177 IS 1-3 BP 123 EP 130 DI 10.1016/0378-4371(91)90143-Z PG 8 WC Physics, Multidisciplinary SC Physics GA GJ927 UT WOS:A1991GJ92700018 ER PT J AU FERER, M SAMS, WN GEISBRECHT, RA SMITH, DH AF FERER, M SAMS, WN GEISBRECHT, RA SMITH, DH TI SCALING OF FRACTAL FLOW SO PHYSICA A LA English DT Article ID POROUS-MEDIA AB For fractal, two-phase flow, we show that the standard Darcy's law treatment is incorrect. We present a scaling theory for the saturation of injected fluid and for its current, commonly called fractional flow. These scaling predictions are verified using a standard model of two-phase flow in two dimensions with a viscosity ratio large enough such that the flow fractal for the size of the systems considered. Our scaling theory follows closely the critical point scaling approach pioneered by Michael Fisher and others. C1 W VIRGINIA UNIV,DEPT PHYS,MORGANTOWN,WV 26506. RP FERER, M (reprint author), MORGANTOWN ENERGY TECHNOL CTR,MORGANTOWN,WV 26507, 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 0378-4371 J9 PHYSICA A JI Physica A PD SEP 15 PY 1991 VL 177 IS 1-3 BP 273 EP 280 DI 10.1016/0378-4371(91)90164-8 PG 8 WC Physics, Multidisciplinary SC Physics GA GJ927 UT WOS:A1991GJ92700039 ER PT J AU ALEXANDER, KB KROEGER, DM BENTLEY, J BRYNESTAD, J AF ALEXANDER, KB KROEGER, DM BENTLEY, J BRYNESTAD, J TI GRAIN-BOUNDARY COMPOSITIONS IN STOICHIOMETRIC AND OFF-STOICHIOMETRIC Y1BA2CU3O7-X SO PHYSICA C LA English DT Article ID CU-O; CRYSTAL-CHEMISTRY; SUPERCONDUCTORS; MICROSTRUCTURE; YBA2CU3O7-X; SYSTEM AB The grain boundary segregation behavior of stoichiometric and off-stoichiometric YBa2Cu3O7-x has been studied with analytical electron microscopy (AEM) to complement previous results obtained with Auger electron spectroscopy (AES). It was observed that the grain boundary segregation levels varied from boundary to boundary. In stoichiometry material, excess copper and deficient oxygen were observed at the grain boundaries. In materials containing excess barium, excess yttrium and deficient copper levels were observed at the grain boundaries. The grain boundary segregation levels in the materials containing excess barium can be related to the resistivity and critical current density results. Preferential segregation to specific sites in grain boundaries was observed by AEM. The effect of grain boundary segregation on the superconducting properties of these materials is discussed in terms of the weak link behavior and a possible percolative mechanism in order to maintain a continuous current path. C1 OAK RIDGE NATL LAB,DIV CHEM,OAK RIDGE,TN 37831. RP ALEXANDER, KB (reprint author), OAK RIDGE NATL LAB,DIV MET & CERAM,POB 2008,OAK RIDGE,TN 37831, USA. NR 45 TC 16 Z9 16 U1 0 U2 0 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0921-4534 J9 PHYSICA C JI Physica C PD SEP 15 PY 1991 VL 180 IS 5-6 BP 337 EP 350 DI 10.1016/0921-4534(91)90545-A PG 14 WC Physics, Applied SC Physics GA GH633 UT WOS:A1991GH63300006 ER PT J AU LICHTI, RL BOEKEMA, C LAM, JC COOKE, DW COX, SFJ TING, ST CROW, JE AF LICHTI, RL BOEKEMA, C LAM, JC COOKE, DW COX, SFJ TING, ST CROW, JE TI DISRUPTION OF ANTIFERROMAGNETIC ORDER IN ZN-DOPED LA2CUO4 SO PHYSICA C LA English DT Article ID HIGH-TEMPERATURE SUPERCONDUCTIVITY; HIGH-TC SUPERCONDUCTIVITY; BA-CU-O; SPIN; SUBSTITUTIONS; PEROVSKITE; MECHANISM; VACANCIES; STATE; HEAT AB The magnetic phase diagram of La2(Cu1-xZnx)O4 has been determined from zero-field muon-spin-rotation (ZF-mu-SR) data taken at LAMPF for 0 less-than-or-equal-to x less-than-or-equal-to 0.10. Antiferromagnetic onset temperatures follow T(N)(x) from susceptibility measurements on the same samples. However, the order becomes long range, as evidenced by a well-defined internal magnetic field, only at temperatures well below T(N). Extrapolation of our results yields T(N) --> 0 K at x = 0.11 for a single (Cu1-xZnx)O2 plane, and comparison with YBa2(Cu1-xZnx)3O6 implies identical disruption of magnetism by Zn doping in the single- and double-plane systems. C1 SAN JOSE STATE UNIV,SAN JOSE,CA 95192. UNIV CALIF LOS ALAMOS SCI LAB,LOS ALAMOS,NM 87545. RUTHERFORD APPLETON LAB,DIDCOT OX11 0QX,OXON,ENGLAND. FLORIDA STATE UNIV,TALLAHASSEE,FL 32306. RP LICHTI, RL (reprint author), TEXAS TECH UNIV,LUBBOCK,TX 79409, USA. NR 35 TC 17 Z9 17 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 SEP 15 PY 1991 VL 180 IS 5-6 BP 358 EP 364 DI 10.1016/0921-4534(91)90547-C PG 7 WC Physics, Applied SC Physics GA GH633 UT WOS:A1991GH63300008 ER PT J AU BERERA, A DAWSON, KA AF BERERA, A DAWSON, KA TI SINE-GORDON RENORMALIZATION-GROUP ANALYSIS OF THE ORIENTATIONAL PREROUGHENING TRANSITION ON A TRIANGULAR LATTICE SO PHYSICAL REVIEW A LA English DT Article ID INTERFACIAL ROUGHENING TRANSITION; PHASE-TRANSITION; 2 DIMENSIONS; COULOMB GAS; SURFACES; MODEL AB We discuss the existence of a type of interfacial transition which, by analogy with translational preroughening, we name the orientational preroughening transition. A sine-Gordon renormalization-group analysis of the orientational roughening and preroughening transitions for a lattice-interfacial Hamiltonian is presented. Thus we construct an effective Hamiltonian of a tensionless solid-on-solid interface on a triangular lattice and then study its flow using Wilson's momentum-shell renormalization-group method. By analogy to the case for translational roughening for an interface that possesses a surface tension, we find both roughening and preroughening transitions. We also discuss the present uncertainties associated with that and with other preroughening transitions. C1 UNIV CALIF BERKELEY LAWRENCE BERKELEY LAB, DEPT CHEM, BERKELEY, CA 94720 USA. RP UNIV CALIF BERKELEY LAWRENCE BERKELEY LAB, DEPT PHYS, BERKELEY, CA 94720 USA. RI Dawson, Kenneth A./L-2540-2016 OI Dawson, Kenneth A./0000-0002-0568-6588 NR 14 TC 0 Z9 0 U1 1 U2 3 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 SEP 15 PY 1991 VL 44 IS 6 BP 3466 EP 3470 DI 10.1103/PhysRevA.44.3466 PG 5 WC Optics; Physics, Atomic, Molecular & Chemical SC Optics; Physics GA GH320 UT WOS:A1991GH32000017 ER PT J AU KERSTEIN, AR AF KERSTEIN, AR TI FRACTAL DIMENSION OF PROPAGATING INTERFACES IN TURBULENCE SO PHYSICAL REVIEW A LA English DT Article ID FLAMES AB The fractal dimension of propagating interfaces in turbulence is analyzed using a variant of a method recently used to obtain intermittency corrections to the fractal dimension of diffusive-scalar interfaces. The fractal dimension is found to be the same as for diffusive-scalar interfaces. RP KERSTEIN, AR (reprint author), SANDIA NATL LABS,COMBUST RES FACIL,LIVERMORE,CA 94551, USA. NR 10 TC 5 Z9 5 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 SEP 15 PY 1991 VL 44 IS 6 BP 3633 EP 3635 DI 10.1103/PhysRevA.44.3633 PG 3 WC Optics; Physics, Atomic, Molecular & Chemical SC Optics; Physics GA GH320 UT WOS:A1991GH32000037 ER PT J AU ZIOLKOWSKI, RW AF ZIOLKOWSKI, RW TI LOCALIZED WAVE PHYSICS AND ENGINEERING SO PHYSICAL REVIEW A LA English DT Article ID EQUATIONS; MODES AB Issues pertaining to the rate of beam divergence, the beam intensity, and the measured energy efficiency of beams generated by arrays of radiating elements are central to the practical applications of those beams. It will be shown that a localized-wave pulse-driven array can be designed to outperform similar continuous-wave pulse-driven arrays with respect to each of these beam characteristics. This improved performance is quantified by deriving bounds on those beam quantities for the field generated by an arbitrary pulse-driven array. These bounds extend the meaning of near-field distances or diffraction lengths to the situation where the array driving functions can be broad-bandwidth signals. Particular attention is given to transmitting- and receiving-array systems consisting of elements that are not large in comparison to the shortest wavelength of significance contained in the signals driving them. The output signals of such systems are related to the input driving functions by several time derivatives. It is demonstrated that the properties of the resulting beams depend on the higher-order moments of the spectra of the input driving functions and that diffraction degrades the coherence of these higher-order moments more slowly than its lower orders. A properly designed set of input driving signals having a high degree of correlation in the higher-order moments of their spectra will produce a beam that has extended diffraction lengths and localization properties. The localized-wave solutions provide an immediate access to this situation. An alternative type of array is required to realize these localized-wave effects -- one that has independently addressable elements. The enhanced localization effects are then intimately coupled to the proper spatial distribution of broad-bandwidth signals driving the array, i.e., by controlling not only the amplitudes, but also the frequency spectra of the pulse driving the array. Recently reported experimental comparisons between localized-wave and continuous-wave pulse-driven arrays of ultrasonic transducers in water are reexamined in terms of the theoretical developments presented here. It will be shown that the observed performance enhancements of the localized-wave pulse-driven arrays are in agreement with the theoretical predictions. C1 UNIV CALIF LAWRENCE LIVERMORE NATL LAB,LIVERMORE,CA 94550. RP ZIOLKOWSKI, RW (reprint author), UNIV ARIZONA,DEPT ELECT & COMP ENGN,ZENTRUM ELECTROMAGNET,BLDG 104,ROOM 422E,TUCSON,AZ 85721, USA. NR 30 TC 43 Z9 43 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 SEP 15 PY 1991 VL 44 IS 6 BP 3960 EP 3984 DI 10.1103/PhysRevA.44.3960 PG 25 WC Optics; Physics, Atomic, Molecular & Chemical SC Optics; Physics GA GH320 UT WOS:A1991GH32000070 ER PT J AU ABDALLAH, J CLARK, REH PEEK, JM AF ABDALLAH, J CLARK, REH PEEK, JM TI EXCITED-STATE 1S-2P ABSORPTION BY ALUMINUM IONS WITH PARTIALLY FILLED L-SHELLS SO PHYSICAL REVIEW A LA English DT Note AB The purpose of this paper is to quantify the role of initial configurations that have an electron beyond the L shell in 1s-2p absorption of aluminum ions. The study is done in the context of a recent x-ray transmission experiment and is based on a theoretical model that is in good agreement with the measurements. In addition, the method of Epstein will be used to study the temperature-dependent effect of excited states on the cross section for the individual ions. Results indicate that about 50% of the absorption is due to initial configurations that have an excited electron beyond the L shell, and the overall opacity of the 1s-2p manifold of transitions can be enhanced by these configurations at elevated temperatures for some ion species. RP ABDALLAH, J (reprint author), UNIV CALIF LOS ALAMOS SCI LAB,LOS ALAMOS,NM 87545, USA. NR 6 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 1050-2947 J9 PHYS REV A JI Phys. Rev. A PD SEP 15 PY 1991 VL 44 IS 6 BP 4072 EP 4075 DI 10.1103/PhysRevA.44.4072 PG 4 WC Optics; Physics, Atomic, Molecular & Chemical SC Optics; Physics GA GH320 UT WOS:A1991GH32000078 ER PT J AU DEISSLER, RJ BRAND, HR AF DEISSLER, RJ BRAND, HR TI INTERACTION OF 2-DIMENSIONAL LOCALIZED SOLUTIONS NEAR A WEAKLY INVERTED BIFURCATION SO PHYSICAL REVIEW A LA English DT Note ID COHERENT STRUCTURES; MULTIDIMENSIONS; INSTABILITIES; EVOLUTION AB We study the interaction of two-dimensional (2D) solutions as they arise for the envelope equations for a subcritical bifurcation to traveling waves. We show that these 2D localized solutions can collide and reemerge unchanged in size and shape after the collision in contrast to what is found in 2D soliton systems. Various other types of behavior arise as the impact parameter and the cross coupling between the waves are varied. We point out that these phenomena should be observable experimentally for hydrodynamic instabilities in anisotropic liquids such as nematic liquid crystals. C1 UNIV CALIF LOS ALAMOS SCI LAB,CTR NONLINEAR STUDIES,LOS ALAMOS,NM 87545. UNIV ESSEN GESAMTHSCH,FACHBEREICH PHYS,W-4300 ESSEN 1,GERMANY. NR 16 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 1050-2947 J9 PHYS REV A JI Phys. Rev. A PD SEP 15 PY 1991 VL 44 IS 6 BP R3411 EP R3414 PG 4 WC Optics; Physics, Atomic, Molecular & Chemical SC Optics; Physics GA GH320 UT WOS:A1991GH32000004 ER PT J AU ZHOU, Y BOWEN, SP MANCINI, JD AF ZHOU, Y BOWEN, SP MANCINI, JD TI MANY-ELECTRON VARIATIONAL CALCULATION FOR THE ONE-DIMENSIONAL ANDERSON LATTICE SO PHYSICAL REVIEW B LA English DT Article ID GROUND-STATE; MODEL AB We present a variational method for studying the ground-state properties of the one-dimensional Anderson model with periodic boundary conditions. Our results are compared with exact Monte Carlo results and show excellent agreement in the large-U limit. We argue that poor results in the vanishing-U range are due to the truncated basis chosen, as well as the fact that all fluctuations are treated equally. C1 FORDHAM UNIV,DEPT PHYS,BRONX,NY 10458. RP ZHOU, Y (reprint author), ARGONNE NATL LAB,ARGONNE,IL 60439, USA. NR 27 TC 6 Z9 7 U1 0 U2 1 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 1098-0121 J9 PHYS REV B JI Phys. Rev. B PD SEP 15 PY 1991 VL 44 IS 11 BP 5482 EP 5486 DI 10.1103/PhysRevB.44.5482 PG 5 WC Physics, Condensed Matter SC Physics GA GF443 UT WOS:A1991GF44300011 ER PT J AU SHIH, A HOR, C ELAM, W KIRKLAND, J MUELLER, D AF SHIH, A HOR, C ELAM, W KIRKLAND, J MUELLER, D TI SURFACE GEOMETRY OF BAO ON W(100) - A SURFACE-EXTENDED X-RAY-ABSORPTION FINE-STRUCTURE STUDY SO PHYSICAL REVIEW B LA English DT Article ID SYNCHROTRON RADIATION; ELECTRONIC-PROPERTIES; W(001); PHASE; SPECTROSCOPY; AMPLITUDE AB A surface-extended x-ray-absorption fine-structure study of ordered monolayers of coadsorbed barium and oxygen on a single-crystal W(100) surface is described. A (square-root 2 X square-root 2)R45-degrees structure with a stoichiometric barium-to-oxygen ratio, and a (2 square-root 2 X square-root 2)R45-degrees structure with a nearly 1:2 barium-to-oxygen atomic ratio both form on W(100). The surface-extended x-ray-absorption fine-structure results indicate that all the barium and oxygen atoms are nearly coplanar in the (square-root 2 X square-root 2)R 45-degrees overlayer. The Ba-to-O distance in this overlayer is 3.20 +/- 0.05 angstrom and beta = 82-degrees +/- 5-degrees, where beta is the angle between the Ba-O internuclear axis and the surface normal. For the (2 square-root 2 X square-root 2)R 45-degrees overlayer, there are two types of oxygen sites. Oxygen atoms nearly coplanar with the barium atoms are also present in these films with a Ba-to-O distance of 3.27 +/- 0.05 angstrom and beta = 75 +/- 4-degrees. Additional oxygen atoms lie outside the barium plane at a distance 2.03 +/- 0.05 angstrom and beta = 23 +/- 10-degrees from the nearest barium atoms. C1 BROOKHAVEN NATL LAB,NATL SYNCHROTRON LIGHT SOURCE,UPTON,NY 11973. NATL INST STAND & TECHNOL,GAITHERSBURG,MD 20899. RP SHIH, A (reprint author), USN,RES LAB,WASHINGTON,DC 20375, USA. NR 27 TC 10 Z9 10 U1 0 U2 3 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 1098-0121 J9 PHYS REV B JI Phys. Rev. B PD SEP 15 PY 1991 VL 44 IS 11 BP 5818 EP 5826 DI 10.1103/PhysRevB.44.5818 PG 9 WC Physics, Condensed Matter SC Physics GA GF443 UT WOS:A1991GF44300057 ER PT J AU TAYLOR, PA NELSON, JS DODSON, BW AF TAYLOR, PA NELSON, JS DODSON, BW TI ADHESION BETWEEN ATOMICALLY FLAT METALLIC SURFACES SO PHYSICAL REVIEW B LA English DT Article ID EMBEDDED-ATOM-METHOD; FORCE MICROSCOPE AB The study of adhesive interactions between atomically flat surfaces in close proximity requires that their separation be controlled and known to within a tenth of an angstrom. In some instances, however, two solids will display a structural instability of their surface layers as their separation approaches the bulk value. When this occurs, an abrupt transition, termed "adhesive avalanche," from a geometry with two spatially distinct surfaces to a single homogeneous structure takes place as the surfaces are brought to within 1-2 angstrom of their equilibrium bulk separation. The avalanche event is the result of a critical growth in the adhesive force gradient at each surface as their separation is reduced to a critical value. We have applied the embedded-atom method to examine this phenomenon for (001)- and (111)-oriented Ni, Cu, and Au surfaces. Both statics and dynamics of adhesion are considered, revealing that tensile stress waves are generated upon avalanche and eventually decay into heat due to the effects of dispersion and dissipation. These tensile waves are associated with a wavelike transmission of the adhesive force, caused by the occurrence of the avalanche event. The presence of avalanche events will cause difficulties in the interpretation of experimental studies of interfacial forces. RP TAYLOR, PA (reprint author), SANDIA NATL LABS,ALBUQUERQUE,NM 87185, USA. NR 14 TC 22 Z9 22 U1 0 U2 5 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 1098-0121 J9 PHYS REV B JI Phys. Rev. B PD SEP 15 PY 1991 VL 44 IS 11 BP 5834 EP 5841 DI 10.1103/PhysRevB.44.5834 PG 8 WC Physics, Condensed Matter SC Physics GA GF443 UT WOS:A1991GF44300059 ER PT J AU LUSCOMBE, JH AGGARWAL, R REED, MA FRENSLEY, WR LUBAN, M AF LUSCOMBE, JH AGGARWAL, R REED, MA FRENSLEY, WR LUBAN, M TI THEORY OF THE FERMI-LEVEL ENERGY IN SEMICONDUCTOR SUPERLATTICES SO PHYSICAL REVIEW B LA English DT Note ID SPECTROSCOPY; ELECTRONS; MINIBANDS AB A theoretical study of the properties of the Fermi level in semiconductor superlattices (SL's) is made which is based upon the carrier occupation of the minibands in thermal equilibrium. We find, for a fixed carrier density and temperature, that the SL Fermi level can differ significantly from that obtained using commonly employed three-dimensional approximations, depending upon the relative spacings and widths of the minibands, with the SL Fermi level being higher than the corresponding bulk value. We find that the SL Fermi level is a sensitive function of the relative widths of the quantum wells and barriers. C1 MIT,DEPT ELECT ENGN & COMP SCI,CAMBRIDGE,MA 02139. YALE UNIV,DEPT ELECT ENGN,NEW HAVEN,CT 06520. UNIV TEXAS,DEPT ELECT ENGN,RICHARDSON,TX 75083. IOWA STATE UNIV SCI & TECHNOL,AMES LAB,AMES,IA 50011. IOWA STATE UNIV SCI & TECHNOL,DEPT PHYS & ASTRON,AMES,IA 50011. RP LUSCOMBE, JH (reprint author), TEXAS INSTRUMENTS INC,CENT RES LAB,DALLAS,TX 75265, USA. NR 14 TC 3 Z9 3 U1 0 U2 2 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 1098-0121 J9 PHYS REV B JI Phys. Rev. B PD SEP 15 PY 1991 VL 44 IS 11 BP 5873 EP 5876 DI 10.1103/PhysRevB.44.5873 PG 4 WC Physics, Condensed Matter SC Physics GA GF443 UT WOS:A1991GF44300062 ER PT J AU ASOKAKUMAR, P LYNN, KG LEUNG, TC NIELSEN, B RUBLOFF, GW WEINBERG, ZA AF ASOKAKUMAR, P LYNN, KG LEUNG, TC NIELSEN, B RUBLOFF, GW WEINBERG, ZA TI SIO2/SI INTERFACE PROPERTIES USING POSITRONS SO PHYSICAL REVIEW B LA English DT Note ID HYDROGEN AB Positron-annihilation spectra are used to identify interface states in a 110-mm-thick, thermally grown (dry, no HCI) SiO2/Si(100) system. A normalized shape parameter (S parameter) is used to characterize the positron-annihilation spectra. The interface-state-density variation under a low-temperature annealing (20-degrees-C-500-degrees-C) is shown to be correlated with the variation in the intensity of the interface shape parameter. Activation and passivation of interface states by atomic hydrogen are demonstrated by repeated in situ hydrogen exposure and vacuum anneal. The present study shows that characterizing the interface states with positron-annihilation techniques opens an avenue for studies involving interface states without the need for a gate electrode. C1 IBM CORP, THOMAS J WATSON RES CTR, DIV RES, YORKTOWN HTS, NY 10598 USA. RP ASOKAKUMAR, P (reprint author), BROOKHAVEN NATL LAB, UPTON, NY 11973 USA. RI Nielsen, Bent/B-7353-2009; Rubloff, Gary/D-4142-2009 OI Nielsen, Bent/0000-0001-7016-0040; Rubloff, Gary/0000-0002-1901-3982 NR 13 TC 17 Z9 17 U1 0 U2 0 PU AMER PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 1098-0121 EI 1550-235X J9 PHYS REV B JI Phys. Rev. B PD SEP 15 PY 1991 VL 44 IS 11 BP 5885 EP 5888 DI 10.1103/PhysRevB.44.5885 PG 4 WC Physics, Condensed Matter SC Physics GA GF443 UT WOS:A1991GF44300065 ER PT J AU KUMAR, S BHADRA, R FARTASH, A GRIMSDITCH, M KIM, C QADRI, SB EDELSTEIN, AS AF KUMAR, S BHADRA, R FARTASH, A GRIMSDITCH, M KIM, C QADRI, SB EDELSTEIN, AS TI BRILLOUIN-SCATTERING FROM ION-BEAM-SPUTTERED CU/NI SUPERLATTICES SO PHYSICAL REVIEW B LA English DT Note ID SURFACE ACOUSTIC-WAVES; METALLIC SUPERLATTICES; SUPER-LATTICES; FILMS; FOILS; PHONONS AB In order to study the effect of fabrication technique on elastic properties of the superlattices, we have investigated a series of ion-beam-sputtered Cu/Ni superlattices and compared the results with those previously reported on evaporated samples. No systematic differences were observed in the relative intensities of the x-ray peaks from samples fabricated by the two techniques. The Brillouin-scattering results show no modulation-wavelength dependence. C1 USN,RES LAB,WASHINGTON,DC 20375. RP KUMAR, S (reprint author), ARGONNE NATL LAB,DIV MAT SCI,ARGONNE,IL 60439, USA. NR 19 TC 16 Z9 16 U1 0 U2 0 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 1098-0121 J9 PHYS REV B JI Phys. Rev. B PD SEP 15 PY 1991 VL 44 IS 11 BP 5905 EP 5907 DI 10.1103/PhysRevB.44.5905 PG 3 WC Physics, Condensed Matter SC Physics GA GF443 UT WOS:A1991GF44300070 ER PT J AU NI, QX SHINAR, J VARDENY, ZV GRIGORAS, S PANG, Y IJADIMAGHSOODI, S BARTON, TJ AF NI, QX SHINAR, J VARDENY, ZV GRIGORAS, S PANG, Y IJADIMAGHSOODI, S BARTON, TJ TI ANOMALOUS OPTICAL AND ESR PROPERTIES OF DOPED POLYDIETHYNYLSILANES SO PHYSICAL REVIEW B LA English DT Note ID DIATOMIC POLYMER AB The optical, transport, and ESR properties of soluble conducting four-membered polydiethynylsilane heterocycles are described. The undoped one-dimensional gap is 2.0 eV in both films and solutions; no photoluminescence is observed. I2 doping induces a single absorption band at approximately 1.05 eV in solutions and lightly doped films, but another at approximately 0.55 eV in heavily doped films. Both are correlated with strong ir-active vibrations associated with known lines in Raman scattering. The doping-induced ESR of the solutions is linear in the 1.05-eV peak, but only approximately 2% of the carriers yield an ESR, which is motionally narrowed. No light-induced ESR is detected. The results are discussed in relation to solitons, polarons, and bipolarons in a degenerate ground-state system. C1 IOWA STATE UNIV SCI & TECHNOL,DEPT PHYS,AMES,IA 50011. UNIV UTAH,DEPT PHYS,SALT LAKE CITY,UT 84112. DOW CORNING CORP,MIDLAND,MI 48686. RP NI, QX (reprint author), IOWA STATE UNIV SCI & TECHNOL,AMES LAB,AMES,IA 50011, USA. NR 17 TC 8 Z9 8 U1 0 U2 1 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 1098-0121 J9 PHYS REV B JI Phys. Rev. B PD SEP 15 PY 1991 VL 44 IS 11 BP 5939 EP 5942 DI 10.1103/PhysRevB.44.5939 PG 4 WC Physics, Condensed Matter SC Physics GA GF443 UT WOS:A1991GF44300079 ER PT J AU GUBERNATIS, JE JARRELL, M SILVER, RN SIVIA, DS AF GUBERNATIS, JE JARRELL, M SILVER, RN SIVIA, DS TI QUANTUM MONTE-CARLO SIMULATIONS AND MAXIMUM-ENTROPY - DYNAMICS FROM IMAGINARY-TIME DATA SO PHYSICAL REVIEW B LA English DT Article ID DILUTE MAGNETIC-ALLOYS; MANY-BODY SYSTEMS; ANDERSON MODEL; ANALYTIC CONTINUATION; DENSITY; STATES AB We report the details of an application of the method of maximum entropy to the extraction of spectral and transport properties from the imaginary-time correlation functions generated from quantum Monte Carlo simulations of the nondegenerate, symmetric, single-impurity Anderson model. We find that these physical properties are approximately universal functions of temperature and frequency when these parameters are scaled by the Kondo temperature. We also found that important details for successful extractions included the generation of statistically independent, Gaussian-distributed data, and a good choice of a default model to represent the state of our prior knowledge about the result in the absence of data. We suggest that our techniques are not restricted to the Hamiltonian and quantum Monte Carlo algorithm used here, but that maximum entropy and these techniques lay the general groundwork for the extraction of dynamical information from imaginary-time data generated by other quantum Monte Carlo simulations. C1 UNIV CINCINNATI, DEPT PHYS, CINCINNATI, OH 45221 USA. UNIV CALIF LOS ALAMOS SCI LAB, MANUEL LUJAN JR NEUTRON SCATTERING CTR, LOS ALAMOS, NM 87545 USA. RP GUBERNATIS, JE (reprint author), UNIV CALIF LOS ALAMOS SCI LAB, DIV THEORET, LOS ALAMOS, NM 87545 USA. NR 48 TC 230 Z9 230 U1 1 U2 11 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 SEP 15 PY 1991 VL 44 IS 12 BP 6011 EP 6029 DI 10.1103/PhysRevB.44.6011 PG 19 WC Physics, Condensed Matter SC Physics GA GH553 UT WOS:A1991GH55300003 ER PT J AU LU, HA SLOUGH, CG COLEMAN, RV MAITI, A FALICOV, LM AF LU, HA SLOUGH, CG COLEMAN, RV MAITI, A FALICOV, LM TI METASTABLE CHARGE-DENSITY-WAVE STATES IN NBSE3 STUDIED BY MAGNETOTRANSPORT SO PHYSICAL REVIEW B LA English DT Article ID HIGH MAGNETIC-FIELDS; BREAKDOWN AB Magnetoquantum oscillations in NbSe3 have been used to study metastable electronic states produced by impurity pinning of charge-density waves (CDW's). Simultaneous measurements of the oscillations in separate sections of the crystal have provided information on the distribution of the metastable domain configurations. A model calculation of the magnetic-breakdown network responsible for the magnetoresistance oscillations was used to generate the various observed frequency distributions. The effects of domain boundaries on the oscillatory components of the magnetoresistance and Hall resistance were evaluated from a simple model. Metastable CDW states are shown to be directly related to the volume impurity pinning of the CDW; they also determine the threshold electric fields required for CDW collective motion. C1 UNIV CALIF BERKELEY,DEPT PHYS,BERKELEY,CA 94720. UNIV CALIF BERKELEY LAWRENCE BERKELEY LAB,DIV MAT & CHEM SCI,BERKELEY,CA 94720. RP LU, HA (reprint author), UNIV VIRGINIA,DEPT PHYS,CHARLOTTESVILLE,VA 22901, USA. NR 7 TC 4 Z9 4 U1 0 U2 3 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 1098-0121 J9 PHYS REV B JI Phys. Rev. B PD SEP 15 PY 1991 VL 44 IS 12 BP 6037 EP 6043 DI 10.1103/PhysRevB.44.6037 PG 7 WC Physics, Condensed Matter SC Physics GA GH553 UT WOS:A1991GH55300005 ER PT J AU WU, XL SHINAR, R SHINAR, J AF WU, XL SHINAR, R SHINAR, J TI HYDROGEN DIFFUSION AND DESORPTION IN RF-SPUTTER-DEPOSITED HYDROGENATED AMORPHOUS-GERMANIUM SO PHYSICAL REVIEW B LA English DT Article ID ALPHA-SI-H; DISPERSIVE DIFFUSION; SILICON; TEMPERATURE; RELAXATION; DEFECTS AB Long-range hydrogen motion and desorption at temperatures 180 less-than-or-equal-to T less-than-or-equal-to 310-degrees-C in rf-sputter-deposited hyrogenated amorphous germanium (a-Ge:H) of varying Ge-bonded H content C(H) was studied by secondary-ion mass spectrometry (SIMS) and ir absorption. As in hydrogenated amorphous silicon (a-Si:H), the diffusion constant D(t) decreases with time as D00(omega-t)-alpha. In films of initial H content 5.0 less-than-or-equal-to C(H0) less-than-or-equal-to 7.4 at.%, alpha congruent-to 0.40 is independent of T and C(H0). In a film of C(H0) congruent-to 9.5 at.%, suspected to contain a significant microvoid content, alpha congruent-to 0.65 is also independent of T. In contrast to undoped a-Si:H, C(H) decreases during annealing at temperatures as low as 180-degrees-C. H diffusion to the nearest microvoid and molecular recombination at its surface are therefore suspected to strongly affect the value of alpha. The activation energy E(a) and prefactor D0 of D(t) for constant diffusion length L, D(tL), defined from the linear best fit of lnD(tL) vs 1/T, range for 0.7 to 1.2 eV and 2.2 x 10(-9) to 1.7 x 10(-4) cm2/s, respectively. Among the different samples, E(a) and D0 obey the Meyer-Neldel relation (MNR) D0 = A00exp(E-a/Kt'0), with A00 = 5.5 x 10(-16) cm2/s and T'0 = 530 K. Yet since alpha is independent of T, E(a) is independent of L. D0, however, decreases with L and thus the MNR is not due to a multiple-trapping mechanism. Since T'0 is approximately equal to the average measurement temperature, the significance of the MNR is questionable. At low C(H0) (less-than-or-equal-to 3.6 at.%) no smearing of the deuterium SIMS profiles is observed although C(H) decreases during annealing. This observation is also believed to result from H and D diffusion to the nearest microvoid surface and subsequent molecular recombination. It is in contrast to observations on a-Si:H, where no decrease in C(H) is observed at T less-than-or-equal-to 350-degrees-C beyond the initial annealing step. It is concluded that (i) the microvoid content in a-Ge:H of low C(H0) is significantly higher than in a-Si:H of similar C(H0); (ii) monohydride bonds on microvoid surfaces are considerably deeper H-trapping sites in a-Si:H than in a-Ge:H. It is suspected that in both systems the probability for desorption of H from monohydride bonds on microvoid surfaces is much larger than for reentry into the bulk. C1 IOWA STATE UNIV SCI & TECHNOL,DEPT PHYS,AMES,IA 50011. IOWA STATE UNIV SCI & TECHNOL,MICROELECTR RES CTR,AMES,IA 50011. RP WU, XL (reprint author), IOWA STATE UNIV SCI & TECHNOL,AMES LAB,AMES,IA 50011, USA. NR 26 TC 5 Z9 5 U1 0 U2 1 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 1098-0121 J9 PHYS REV B JI Phys. Rev. B PD SEP 15 PY 1991 VL 44 IS 12 BP 6161 EP 6168 DI 10.1103/PhysRevB.44.6161 PG 8 WC Physics, Condensed Matter SC Physics GA GH553 UT WOS:A1991GH55300019 ER PT J AU DAWSON, P ALEXANDER, KB THOMPSON, JR HAAS, JW FERRELL, TL AF DAWSON, P ALEXANDER, KB THOMPSON, JR HAAS, JW FERRELL, TL TI INFLUENCE OF METAL GRAIN-SIZE ON SURFACE-ENHANCED RAMAN-SCATTERING SO PHYSICAL REVIEW B LA English DT Article ID SCANNING TUNNELING MICROSCOPY; SILVER FILMS; DIFFERENT ROUGHNESS; PLASMON EXCITATION; DEPENDENCE; MECHANISM; RADIATION; PYRIDINE; COPPER; SERS AB The surface roughness of nominally smooth and of randomly roughened thin silver films is characterized using scanning tunneling microscopy and the metal grain size is assessed using transmission electron microscopy. On each type of substrate used, glass or CaF2-roughened glass, the silver films are deposited either very slowly (approximately 0.15 nm s-1) or quite quickly (approximately 2.0 nm s-1). Only silver films deposited on CaF2-roughened glass yield measurable surface-enhanced Raman signals for benzoic acid; the enhancement is brought about by surface field amplification due to the excitation of delocalized surface-plasmon polaritons. However, the surface-enhanced Raman signals obtained from the slow-deposited silver films are significantly better (by about a factor of 3) than those obtained from the fast-deposited silver films on a given CaF2-roughened substrate. The explanation of this observation does not lie with different surface roughness; both types of film yield closely similar data on the scanning tunneling microscope. Rather, it is suggested that the relatively small grain size of the fast-deposited silver films leads to increased elastic scattering of surface-plasmon polaritons at the grain boundaries, with a consequent increase of internal damping. This results in a reduction of the scattered Raman signal. C1 OAK RIDGE NATL LAB,DIV HLTH & SAFETY RES,OAK RIDGE,TN 37830. RP DAWSON, P (reprint author), QUEENS UNIV BELFAST,DEPT PURE & APPL PHYS,BELFAST BT7 1NN,ANTRIM,NORTH IRELAND. NR 42 TC 28 Z9 28 U1 2 U2 4 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 1098-0121 J9 PHYS REV B JI Phys. Rev. B PD SEP 15 PY 1991 VL 44 IS 12 BP 6372 EP 6381 DI 10.1103/PhysRevB.44.6372 PG 10 WC Physics, Condensed Matter SC Physics GA GH553 UT WOS:A1991GH55300042 ER PT J AU OCKO, BM GIBBS, D HUANG, KG ZEHNER, DM MOCHRIE, SGJ AF OCKO, BM GIBBS, D HUANG, KG ZEHNER, DM MOCHRIE, SGJ TI STRUCTURE AND PHASES OF THE AU(001) SURFACE - ABSOLUTE X-RAY REFLECTIVITY SO PHYSICAL REVIEW B LA English DT Article ID ORDER PARAMETER; SCATTERING; RECONSTRUCTION; DIFFRACTION; TRANSITION; BEHAVIOR; LAYER; INTERFACES; AU(111); FILMS AB Specular and nonspecular absolute x-ray-reflectivity measurements have been performed on the Au(001) surface between T = 300 and 1250 K. At all temperatures the surface-normal vibrational amplitudes are increased above the corresponding bulk thermal vibrational amplitude (Debye-Waller factor). Below T = 1170 K, the surface is well described by an incommensurate, corrugated, hexagonal overlayer. The corrugation propagates several layers into the bulk. Above T = 1170 K there is an abrupt decrease in the specular and nonspecular reflectivities, which we interpret in terms of surface disordering. C1 OAK RIDGE NATL LAB,DIV SOLID STATE,OAK RIDGE,TN 37831. MIT,CTR MAT SCI & ENGN,CAMBRIDGE,MA 02139. MIT,DEPT PHYS,CAMBRIDGE,MA 02139. RP OCKO, BM (reprint author), BROOKHAVEN NATL LAB,DEPT PHYS,UPTON,NY 11973, USA. NR 45 TC 89 Z9 89 U1 1 U2 5 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 1098-0121 J9 PHYS REV B JI Phys. Rev. B PD SEP 15 PY 1991 VL 44 IS 12 BP 6429 EP 6443 DI 10.1103/PhysRevB.44.6429 PG 15 WC Physics, Condensed Matter SC Physics GA GH553 UT WOS:A1991GH55300048 ER PT J AU KAWABE, Y JARKA, F PEYGAMBARIAN, N GUO, D MAZUMDAR, S DIXIT, SN KAJZAR, F AF KAWABE, Y JARKA, F PEYGAMBARIAN, N GUO, D MAZUMDAR, S DIXIT, SN KAJZAR, F TI ROLES OF BAND STATES AND 2-PHOTON TRANSITIONS IN THE ELECTROABSORPTION OF A POLYDIACETYLENE SO PHYSICAL REVIEW B LA English DT Note ID SINGLE-CRYSTALS; SPECTRA; ELECTROREFLECTANCE; EXCITONS; FILMS AB We report results of experimental and theoretical investigations of electroabsorption (EA) in a poly[1,6-di(N-carbazolyl)-2,4-hexadiyne] DCH polydiacetylene. In addition to the Stark shift of the exciton, a high-energy feature is seen in EA, whose origin has been the subject of controversy. Based on exact theoretical calculation of the EA within an extended Peierls-Hubbard model, we ascribe the high-energy signal to transitions to a continuum threshold. We briefly discuss the contributions of these band threshold states to the third-order optical nonlinearity, chi(3). C1 UNIV ARIZONA,DEPT PHYS,TUCSON,AZ 85721. UNIV CALIF LAWRENCE LIVERMORE NATL LAB,LIVERMORE,CA 94550. IDEMITSU KOSAN CO LTD,CENT RES LABS,1280 KAMIIZUMI,SODEGAURA,CHIBA 29902,JAPAN. CENS,CEA,INST RECH TECHNOL & DEV IND,PHYS ELECTR MAT LAB,F-91191 GIF SUR YVETTE,FRANCE. RP KAWABE, Y (reprint author), UNIV ARIZONA,CTR OPT SCI,TUCSON,AZ 85721, USA. NR 17 TC 40 Z9 42 U1 0 U2 6 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 1098-0121 J9 PHYS REV B JI Phys. Rev. B PD SEP 15 PY 1991 VL 44 IS 12 BP 6530 EP 6533 DI 10.1103/PhysRevB.44.6530 PG 4 WC Physics, Condensed Matter SC Physics GA GH553 UT WOS:A1991GH55300062 ER PT J AU BARGER, V PHILLIPS, RJN WHISNANT, K AF BARGER, V PHILLIPS, RJN WHISNANT, K TI SOLAR-NEUTRINO SOLUTIONS WITH MATTER-ENHANCED FLAVOR-CHANGING NEUTRAL-CURRENT SCATTERING SO PHYSICAL REVIEW D LA English DT Article ID R-PARITY BREAKING; SUPERSYMMETRIC MODELS; ELECTRON-NEUTRINO; OSCILLATION PARAMETERS; POSSIBLE EXPLANATION; NUMBER VIOLATION; STANDARD MODEL; EARTH; PUZZLE; SPECTROSCOPY AB We explore quantitatively recent suggestions that the solar-neutrino puzzle may be explained by matter enhancement of nonstandard neutral-current scattering of neutrinos on d quarks. These neutral currents introduce two new parameters, relating to flavor-diagonal and off-diagonal v-d scattering, which affect the dynamical mixing of two neutrino flavors in the Sun. We consider this mixing in three alternative scenarios: (a) massless neutrinos, (b) massive neutrinos with off-diagonal but no new diagonal currents, and (c) massive neutrinos with both off-diagonal and new diagonal currents. We determine the regions in parameter space that give consistency between the standard solar model and existing solar-neutrino data from the Homestake and Kamiokande-II experiments, and give the corresponding predictions for future experiments with gallium and superfluid helium detectors. We also discuss the more general situation, with nonstandard neutral-current scattering from u quarks and electrons as well as from d quarks, and consider the effects of transmission through the Earth. Finally, we examine the bounds on nonstandard neutral-current neutrino scattering imposed by other experiments; some particular classes of solution are thereby excluded, but a variety of possibilities remains. C1 RUTHERFORD APPLETON LAB,DIDCOT OX11 0QX,OXON,ENGLAND. IOWA STATE UNIV SCI & TECHNOL,DEPT PHYS,AMES,IA 50011. IOWA STATE UNIV SCI & TECHNOL,AMES LAB,AMES,IA 50011. RP BARGER, V (reprint author), UNIV WISCONSIN,DEPT PHYS,MADISON,WI 53706, USA. NR 79 TC 94 Z9 94 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 SEP 15 PY 1991 VL 44 IS 6 BP 1629 EP 1643 DI 10.1103/PhysRevD.44.1629 PG 15 WC Astronomy & Astrophysics; Physics, Particles & Fields SC Astronomy & Astrophysics; Physics GA GG502 UT WOS:A1991GG50200003 ER PT J AU GRADWOHL, BA AF GRADWOHL, BA TI COSMIC SUPERFLUID PHASE SO PHYSICAL REVIEW D LA English DT Article ID REDSHIFT-DISTANCE SAMPLES; GOLDSTONE BOSONS; GLOBAL STRINGS; ELLIPTICAL GALAXIES; DENSITY FIELDS; EARLY UNIVERSE; ORIGIN; SPECTROSCOPY; BARYOGENESIS; PHOTOMETRY AB The Universe may have undergone a superfluidlike phase during its evolution, resulting from the injection of nontopological charge into the spontaneously broken vacuum. In the presence of vortices this charge is identified with angular momentum. This leads to turbulent domains on the scale of the correlation length. By restoring the symmetry at low temperatures the vortices dissociate and push the charges to the boundaries of these domains. If we (phenomenologically) scale our model to very low energies, we can incorporate it in a late-time phase transition and form large-scale structure in the boundary layers of the correlation volumes. The novel feature of our model lies in the fact that the dark matter is endowed with coherent motion. We elaborate on the possibilities of identifying this flow around superfluid vortices with the observed large-scale bulk motion. If this identification is possible, then we can make the definite prediction that a more extended map of peculiar velocities would have to reveal large-scale circulations in the flow pattern. RP GRADWOHL, BA (reprint author), NASA,FERMILAB ASTROPHYS CTR,FERMI NATL ACCELERATOR LAB,POB 500,BATAVIA,IL 60510, USA. NR 43 TC 6 Z9 6 U1 1 U2 1 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 0556-2821 J9 PHYS REV D JI Phys. Rev. D PD SEP 15 PY 1991 VL 44 IS 6 BP 1685 EP 1690 DI 10.1103/PhysRevD.44.1685 PG 6 WC Astronomy & Astrophysics; Physics, Particles & Fields SC Astronomy & Astrophysics; Physics GA GG502 UT WOS:A1991GG50200009 ER PT J AU BOWCOCK, P GREGORY, R AF BOWCOCK, P GREGORY, R TI MULTIDIMENSIONAL TUNNELING AND COMPLEX MOMENTUM SO PHYSICAL REVIEW D LA English DT Article ID COUPLED ANHARMONIC OSCILLATORS; FALSE-VACUUM DECAY; TRAVERSAL TIME; TRANSMISSION; REFLECTION; INFLATION AB We examine the problem of modeling tunneling phenomena in more than one dimension. We find that existing techniques are inadequate in a wide class of situations because of their inability to deal with concurrent classical motion. We show how to generalize these methods to allow for complex momenta, and demonstrate the improved techniques with a selection of illustrative examples. We comment on possible applications. C1 NASA,FERMILAB ASTROPHYS CTR,FERMI NATL ACCELERATOR LAB,BATAVIA,IL 60510. RP BOWCOCK, P (reprint author), UNIV CHICAGO,ENRICO FERMI INST,5640 S ELLIS AVE,CHICAGO,IL 60637, USA. NR 21 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 SEP 15 PY 1991 VL 44 IS 6 BP 1774 EP 1785 DI 10.1103/PhysRevD.44.1774 PG 12 WC Astronomy & Astrophysics; Physics, Particles & Fields SC Astronomy & Astrophysics; Physics GA GG502 UT WOS:A1991GG50200019 ER PT J AU TANG, AC BRODSKY, SJ PAULI, HC AF TANG, AC BRODSKY, SJ PAULI, HC TI DISCRETIZED LIGHT-CONE QUANTIZATION - FORMALISM FOR QUANTUM ELECTRODYNAMICS SO PHYSICAL REVIEW D LA English DT Article ID INFINITE-MOMENTUM FRAME; PAIR ANNIHILATION PROCESSES; LEPTON-NUCLEON SCATTERING; ONE TIME DIMENSION; EXCLUSIVE PROCESSES; FIELD-THEORY; FORM-FACTORS; HADRONIC WAVEFUNCTIONS; EVOLUTION EQUATIONS; DIRAC FIELDS AB A general nonperturbative method for solving quantum field theories in three space and one time dimensions, discretized light-cone quantization, is outlined and applied to quantum electrodynamics. This numerical method is frame independent and can be formulated such that ultraviolet regularization is independent of the momentum-space discretization. In this paper we discuss the construction of the light-cone Fock basis, ultraviolet regularization, infrared regularization, and the renormalization techniques required for solving QED as a light-cone Hamiltonian theory. C1 MAX PLANCK INST NUCL PHYS,W-6900 HEIDELBERG 1,GERMANY. RP TANG, AC (reprint author), STANFORD UNIV,STANFORD LINEAR ACCELERATOR CTR,STANFORD,CA 94309, USA. NR 61 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 SEP 15 PY 1991 VL 44 IS 6 BP 1842 EP 1865 DI 10.1103/PhysRevD.44.1842 PG 24 WC Astronomy & Astrophysics; Physics, Particles & Fields SC Astronomy & Astrophysics; Physics GA GG502 UT WOS:A1991GG50200026 ER PT J AU PISARSKI, RD AF PISARSKI, RD TI FERMION MASS IN 3 DIMENSIONS AND THE RENORMALIZATION-GROUP SO PHYSICAL REVIEW D LA English DT Article ID CHIRAL-SYMMETRY-BREAKING; VECTOR-GLUON MODEL; GAUGE-THEORIES; CRITICAL-BEHAVIOR; 2+1 DIMENSIONS; ELECTRODYNAMICS; TRANSITIONS; GENERATION; FLAVORS; ORIGIN AB The spontaneous generation of a parity-even mass for fermions in three dimensions is analyzed by using effective Lagrangians and the renormalization group. To leading order in epsilon, an expansion about 4-epsilon dimensions predicts the spontaneous generation of mass for two or more flavors of four-component fermions. RP PISARSKI, RD (reprint author), BROOKHAVEN NATL LAB,DEPT PHYS,UPTON,NY 11973, USA. NR 41 TC 31 Z9 32 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 SEP 15 PY 1991 VL 44 IS 6 BP 1866 EP 1872 DI 10.1103/PhysRevD.44.1866 PG 7 WC Astronomy & Astrophysics; Physics, Particles & Fields SC Astronomy & Astrophysics; Physics GA GG502 UT WOS:A1991GG50200027 ER PT J AU FORSTER, R HIPPLER, H HOYERMANN, K ROHDE, G HARDING, LB AF FORSTER, R HIPPLER, H HOYERMANN, K ROHDE, G HARDING, LB TI REMPI MASS-SPECTRUM OF THE OH RADICAL IN THE GAS-PHASE SO CHEMICAL PHYSICS LETTERS LA English DT Article ID LASER-INDUCED FLUORESCENCE; RESONANCE AB The resonance-enhanced multiphoton ionization (REMPI) of the OH radical in the gas phase was studied using an isothermal discharge-flow reactor for the production of OH radicals (H + NO2 --> OH + NO), tunable laser light from an excimer-pumped dye laser, and a time-of-flight (TOF) mass spectrometer. A mass-resolved REMPI spectrum was found in the wavelength region of 290-310 nm, which is assigned to a (3 + 1) ionization process. An ab initio quantum-chemical calculation predicts the Rydberg state, verified by the experiment. C1 ARGONNE NATL LAB, DIV CHEM, THEORET CHEM GRP, ARGONNE, IL 60439 USA. RP FORSTER, R (reprint author), UNIV GOTTINGEN, INST PHYS CHEM, TAMMANNSTR 6, W-3400 GOTTINGEN, GERMANY. OI Forster, Robert/0000-0001-5079-3123 NR 19 TC 7 Z9 7 U1 0 U2 10 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0009-2614 J9 CHEM PHYS LETT JI Chem. Phys. Lett. PD SEP 13 PY 1991 VL 183 IS 6 BP 465 EP 470 DI 10.1016/0009-2614(91)80160-Y PG 6 WC Chemistry, Physical; Physics, Atomic, Molecular & Chemical SC Chemistry; Physics GA GF961 UT WOS:A1991GF96100001 ER PT J AU LIU, JJ FEYEREISEN, MW ALMLOF, J ROHLFING, CM SAEBO, S AF LIU, JJ FEYEREISEN, MW ALMLOF, J ROHLFING, CM SAEBO, S TI ABINITIO STUDIES OF SUBSTITUTED DIAMOND-LIKE CARBON CLUSTERS SO CHEMICAL PHYSICS LETTERS LA English DT Article ID PRINCIPLES AB Ab initio calculations at the Hartree-Fock and second-order perturbation (MP2) levels were performed on diamond-like clusters with a single nitrogen substitutional impurity. The largest cluster consists of 71 atoms and 387 basis functions, and the MP2 calculations correlated all 177 valence electrons. The results at the SCF level suggest that the odd electron introduced by the nitrogen atom is bound in a Rydberg-like state outside the cluster. However, inclusion of electron correlation makes this state considerably less diffuse. The use of fractional nuclear charges was also examined. C1 SANDIA NATL LABS,DIV THEORET,LIVERMORE,CA 94551. MISSISSIPPI STATE UNIV,DEPT CHEM,MISSISSIPPI STATE,MS 39762. RP LIU, JJ (reprint author), UNIV MINNESOTA,DEPT CHEM,MINNEAPOLIS,MN 55455, USA. NR 25 TC 6 Z9 6 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 SEP 13 PY 1991 VL 183 IS 6 BP 478 EP 482 DI 10.1016/0009-2614(91)80162-Q PG 5 WC Chemistry, Physical; Physics, Atomic, Molecular & Chemical SC Chemistry; Physics GA GF961 UT WOS:A1991GF96100003 ER PT J AU MARLAND, G TURHOLLOW, A AF MARLAND, G TURHOLLOW, A TI CORN POWER SO SCIENCE LA English DT Letter C1 OAK RIDGE NATL LAB,DIV ENERGY,OAK RIDGE,TN 37831. RP MARLAND, G (reprint author), OAK RIDGE NATL LAB,DIV ENVIRONM SCI,OAK RIDGE,TN 37831, USA. NR 2 TC 0 Z9 0 U1 0 U2 1 PU AMER ASSOC ADVANCEMENT SCIENCE PI WASHINGTON PA 1200 NEW YORK AVE, NW, WASHINGTON, DC 20005 SN 0036-8075 J9 SCIENCE JI Science PD SEP 13 PY 1991 VL 253 IS 5025 BP 1194 EP 1194 DI 10.1126/science.253.5025.1194-b PG 1 WC Multidisciplinary Sciences SC Science & Technology - Other Topics GA GE689 UT WOS:A1991GE68900004 PM 17831421 ER PT J AU GREENWADE, LE AF GREENWADE, LE TI SCIENTIFIC VISUALIZATION - PRACTICES AND PROMISES SO NATURE LA English DT Article RP GREENWADE, LE (reprint author), IDAHO NATL ENGN LAB,IDAHO FALLS,ID 83415, USA. NR 10 TC 0 Z9 1 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 SEP 12 PY 1991 VL 353 IS 6340 BP 191 EP 192 DI 10.1038/353191a0 PG 2 WC Multidisciplinary Sciences SC Science & Technology - Other Topics GA GE731 UT WOS:A1991GE73100061 PM 1891047 ER PT J AU WALLOW, TI NOVAK, BM AF WALLOW, TI NOVAK, BM TI IN AQUA SYNTHESIS OF WATER-SOLUBLE POLY(PARA-PHENYLENE) DERIVATIVES SO JOURNAL OF THE AMERICAN CHEMICAL SOCIETY LA English DT Note ID RIGID-ROD POLYMERS; SIDE-CHAINS; POLYMERIZATION; POLYPHENYLENE C1 UNIV CALIF BERKELEY,DEPT CHEM,BERKELEY,CA 94720. LAWRENCE BERKELEY LAB,DIV MAT SCI,CTR ADV MAT,BERKELEY,CA 94720. NR 42 TC 216 Z9 217 U1 0 U2 13 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 SN 0002-7863 J9 J AM CHEM SOC JI J. Am. Chem. Soc. PD SEP 11 PY 1991 VL 113 IS 19 BP 7411 EP 7412 DI 10.1021/ja00019a042 PG 2 WC Chemistry, Multidisciplinary SC Chemistry GA GF104 UT WOS:A1991GF10400042 ER PT J AU BARKIGIA, KM CHANG, CK FAJER, J AF BARKIGIA, KM CHANG, CK FAJER, J TI MOLECULAR-STRUCTURE OF A DIHYDROXYCHLORIN - A MODEL OF THE GREEN HEME-D AND OF A PHOTODYNAMIC THERAPY SENSITIZER SO JOURNAL OF THE AMERICAN CHEMICAL SOCIETY LA English DT Note ID PROSTHETIC GROUP; PROPOSED STRUCTURE; CRYSTAL; CHEMISTRY; DIHYDRATE C1 MICHIGAN STATE UNIV,DEPT CHEM,E LANSING,MI 48824. RP BARKIGIA, KM (reprint author), BROOKHAVEN NATL LAB,DEPT APPL SCI,UPTON,NY 11973, USA. RI Chang, Chi/B-1675-2010 OI Chang, Chi/0000-0002-4113-1950 NR 28 TC 24 Z9 24 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 SEP 11 PY 1991 VL 113 IS 19 BP 7445 EP 7447 DI 10.1021/ja00019a065 PG 3 WC Chemistry, Multidisciplinary SC Chemistry GA GF104 UT WOS:A1991GF10400065 ER PT J AU REARDON, JT SPIELMANN, P HUANG, JC SASTRY, S SANCAR, A HEARST, JE AF REARDON, JT SPIELMANN, P HUANG, JC SASTRY, S SANCAR, A HEARST, JE TI REMOVAL OF PSORALEN MONOADDUCTS AND CROSS-LINKS BY HUMAN CELL-FREE-EXTRACTS SO NUCLEIC ACIDS RESEARCH LA English DT Article ID REPAIR SYNTHESIS; DNA; REPLICATION; COMPLEXES; LINKS; RECA AB Human cell free extracts are capable of carrying out damage-induced DNA synthesis in response to DNA damage by UV, psoralen, and cisplatin. We show that this damage-induced DNA synthesis is associated with removal of psoralen adducts and therefore is 'repair synthesis' and not an aberrant DNA synthesis reaction potentiated by DNA deformed by adducts. By comparing the denaturable fraction of psoralen adducted DNA which becomes labeled in the repair reaction to that of terminally labeled DNA (without repair) we have found that all DNA synthesis induced by psoralen monoadducts is the consequence of removal of these adducts. By the same approach we have obtained preliminary evidence that this in vitro system is capable of removing psoralen crosslinks as well. C1 UNIV N CAROLINA, SCH MED, DEPT BIOCHEM & BIOPHYS, CHAPEL HILL, NC 27599 USA. UNIV CALIF BERKELEY LAWRENCE BERKELEY LAB, DEPT CHEM, BERKELEY, CA 94720 USA. UNIV CALIF BERKELEY LAWRENCE BERKELEY LAB, DIV CHEM BIODYNAM, BERKELEY, CA 94720 USA. FU NIEHS NIH HHS [ES05513-02]; NIGMS NIH HHS [GM32833] NR 22 TC 38 Z9 39 U1 0 U2 0 PU OXFORD UNIV PRESS PI OXFORD PA GREAT CLARENDON ST, OXFORD OX2 6DP, ENGLAND SN 0305-1048 J9 NUCLEIC ACIDS RES JI Nucleic Acids Res. PD SEP 11 PY 1991 VL 19 IS 17 BP 4623 EP 4629 DI 10.1093/nar/19.17.4623 PG 7 WC Biochemistry & Molecular Biology SC Biochemistry & Molecular Biology GA GF998 UT WOS:A1991GF99800005 PM 1891353 ER PT J AU ALMON, AC AF ALMON, AC TI TRACE MULTIELEMENT DETERMINATIONS IN REACTOR MODERATOR WATER - SIMULTANEOUS DETERMINATION OF COPPER, GOLD, SILVER AND MERCURY USING DIFFERENTIAL-PULSE STRIPPING VOLTAMMETRY SO ANALYTICA CHIMICA ACTA LA English DT Article DE DIFFERENTIAL PULSE VOLTAMMETRY; COPPER; GOLD; REACTOR MODERATOR WATER; SILVER; MERCURY; WATERS AB A rapid, inexpensive, method for multi-element trace determinations in reactor moderator heavy water is described. Samples were analyzed for copper, silver, gold and mercury at the low mu-g l-1 level using differential-pulse stripping voltammetry (DPSV); these ions are kept below 25-mu-g l-1 to avoid possible corrosion to the reactor vessel. A high concentration of aluminum and iron in the samples prevented analysis by inductively coupled plasma spectrometry; the DPSV method described is unaffected by these interferences. As the method involves a solution-phase determination, it has the important advantage of not volatilizing highly tritiated samples. RP ALMON, AC (reprint author), WESTINGHOUSE SAVANNAH RIVER CO,SAVANNAH RIVER LAB,AIKEN,SC 29808, USA. NR 7 TC 7 Z9 7 U1 0 U2 4 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0003-2670 J9 ANAL CHIM ACTA JI Anal. Chim. Acta PD SEP 10 PY 1991 VL 249 IS 2 BP 447 EP 450 DI 10.1016/S0003-2670(00)83018-4 PG 4 WC Chemistry, Analytical SC Chemistry GA GG660 UT WOS:A1991GG66000018 ER PT J AU HOLLAND, A POWELL, ET FONCK, RJ AF HOLLAND, A POWELL, ET FONCK, RJ TI IMAGE-RECONSTRUCTION METHODS FOR THE PBX-M PINHOLE CAMERA SO APPLIED OPTICS LA English DT Article ID CROSS-SECTIONS; ENTROPY AB We describe two methods that have been used to reconstruct the soft x-ray emission profile of the PBX-M tokamak from the projected images recorded by the PBX-M pinhole camera [Proc. Soc. Photo-Opt. Instrum. Eng. 691, 111 (1986)]. Both methods must accurately represent the shape of the reconstructed profile while also providing a degree of immunity to noise in the data. The first method is a simple least-squares fit to the data. This has the advantage of being fast and small and thus easily implemented on the PDP-11 computer used to control the video digitizer for the pinhole camera. The second method involves the application of a maximum entropy algorithm to an overdetermined system. This has the advantage of allowing the use of a default profile. This profile contains additional knowledge about the plasma shape that can be obtained from equilibrium fits to the external magnetic measurements. Additionally the reconstruction is guaranteed positive, and the fit to the data can be relaxed by specifying both the amount and distribution of noise in the image. The algorithm described has the advantage of being considerably faster for an overdetermined system than the usual Lagrange multiplier approach to finding the maximum entropy solution [J. Opt. Soc. Am. 62, 511 (1972); Rev. Sci. Instrum. 57, 1557 (1986)]. C1 PRINCETON UNIV,PRINCETON PLASMA PHYS LAB,PRINCETON,NJ 08543. NR 12 TC 4 Z9 4 U1 0 U2 1 PU OPTICAL SOC AMER PI WASHINGTON PA 2010 MASSACHUSETTS AVE NW, WASHINGTON, DC 20036 SN 0003-6935 J9 APPL OPTICS JI Appl. Optics PD SEP 10 PY 1991 VL 30 IS 26 BP 3740 EP 3751 PG 12 WC Optics SC Optics GA GG492 UT WOS:A1991GG49200008 PM 20706452 ER PT J AU ESMAILZADEH, R STARKMAN, GD DIMOPOULOS, S AF ESMAILZADEH, R STARKMAN, GD DIMOPOULOS, S TI PRIMORDIAL NUCLEOSYNTHESIS WITHOUT A COMPUTER SO ASTROPHYSICAL JOURNAL LA English DT Article DE ANALYTICAL METHODS; NUCLEOSYNTHESIS ID UNIVERSE AB Approximate results for the standard theory of big bang nucleosynthesis are derived analytically, i.e., without the use of the Wagoner code, using ideas of fixed points and freezeout. C1 UNIV CALIF BERKELEY LAWRENCE BERKELEY LAB,BERKELEY,CA 94720. STANFORD UNIV,DEPT PHYS,STANFORD,CA 94305. RP ESMAILZADEH, R (reprint author), UNIV CALIF BERKELEY,CTR PARTICLE ASTROPHYS,BERKELEY,CA 94720, USA. NR 12 TC 46 Z9 46 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 SEP 10 PY 1991 VL 378 IS 2 BP 504 EP 518 DI 10.1086/170452 PN 1 PG 15 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA GD781 UT WOS:A1991GD78100008 ER PT J AU SIRONI, G BONELLI, G LIMON, M AF SIRONI, G BONELLI, G LIMON, M TI THE BRIGHTNESS TEMPERATURE OF THE SOUTH CELESTIAL POLE AND THE TEMPERATURE OF THE COSMIC BACKGROUND-RADIATION MEASURED AT 36.6 AND 12 CENTIMETER WAVELENGTH SO ASTROPHYSICAL JOURNAL LA English DT Article DE COSMIC BACKGROUND RADIATION; RADIO SOURCES, EXTENDED ID SPECTRUM AB The absolute temperature of the sky around the south celestial pole has been measured at nu = 0.82 GHz (lambda = 36.6 cm) and nu = 2.5 GHz (lambda = 12 cm) during an observing campaign from the Amundsen Scott Base at the South Pole in 1989 December. The antennas had an angular resolution of 18-degrees x 23-degrees. The measured temperatures of the sky have been used to determine the temperature of the cosmic background radiation in a frequency region where large deviations from a pure Planckian spectrum are expected. The results at 2.5 GHz (T(sky) = 2.58 +/- 0.34 K, T(CBR)th = 2.50 +/- 0.34 K) are fully consistent with the results of previous observations at the same frequency. At 0.82 GHz an undesired level of the system attenuation gave large error bars (T(sky) = 5.7 +/- 1.6 K, T(CBR)th = 2.7 +/- 1.6 K). In spite of that limitation we report the 0.82 GHz results because no data at the same or nearby frequencies can be found in the literature. C1 CNR,IST IFCTR,I-20133 MILAN,ITALY. UNIV CALIF BERKELEY LAWRENCE BERKELEY LAB,BERKELEY,CA 94720. RP SIRONI, G (reprint author), UNIV MILAN,DIPARTMENTO FIS,VIA CELORIA 16,I-20133 MILAN,ITALY. NR 29 TC 33 Z9 33 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 SEP 10 PY 1991 VL 378 IS 2 BP 550 EP 556 DI 10.1086/170456 PN 1 PG 7 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA GD781 UT WOS:A1991GD78100012 ER PT J AU HEUNG, LK TRAN, RS STONER, KJ AF HEUNG, LK TRAN, RS STONER, KJ TI METAL HYDRIDE COMPACTS FOR HYDROGEN ISOTOPE-SEPARATION SO JOURNAL OF THE LESS-COMMON METALS LA English DT Article; Proceedings Paper CT INTERNATIONAL SYMP ON METAL-HYDROGEN SYSTEMS, FUNDAMENTALS AND APPLICATIONS CY SEP 02-07, 1990 CL BANFF, CANADA AB A column packed with pellets of copper-plated LaNi4.25Al0.75 has been evaluated for its separation efficiency using a displacement method. Deuterium breakthrough curves were produced experimentally and compared with those calculated with a stage model. The height equivalent to a theoretical plate was attained and its dependence on temperature and gas flow rate was established. RP HEUNG, LK (reprint author), WESTINGHOUSE SAVANNAH RIVER CO,SAVANNAH RIVER LAB,AIKEN,SC 29808, USA. NR 8 TC 5 Z9 8 U1 0 U2 1 PU ELSEVIER SCIENCE SA LAUSANNE PI LAUSANNE 1 PA PO BOX 564, 1001 LAUSANNE 1, SWITZERLAND SN 0022-5088 J9 J LESS-COMMON MET PD SEP 10 PY 1991 VL 172 BP 1313 EP 1319 DI 10.1016/S0022-5088(06)80041-X PN C PG 7 WC Chemistry, Physical; Metallurgy & Metallurgical Engineering SC Chemistry; Metallurgy & Metallurgical Engineering GA GK510 UT WOS:A1991GK51000041 ER PT J AU FISHER, IA AF FISHER, IA TI SELECTION OF A HYDRIDE FORMER FOR THE SEPARATION OF HYDROGEN ISOTOPES FROM INERT-GASES SO JOURNAL OF THE LESS-COMMON METALS LA English DT Article; Proceedings Paper CT INTERNATIONAL SYMP ON METAL-HYDROGEN SYSTEMS, FUNDAMENTALS AND APPLICATIONS CY SEP 02-07, 1990 CL BANFF, CANADA ID THERMODYNAMICS; ERFE2-H; SYSTEM AB The properties of four hydride-forming materials have been investigated to determine their applicability for use in a process to separate hydrogen isotopes from inert gases. These materials are Zr0.8Ti0.2Ni, Zr0.65Ti0.35Co, NdCo3 and ErFe2. The properties investigated while surveying these materials include ease of activation, isotherm characteristics, kinetics, cycling stability and oxygen stability. The results of the survey indicate NdCo3 to be the hydride former of choice for use in the inert gas separation process. It is the most easily activated and has the most favorable isotherm characteristics (the largest usable capacity, flat plateaux, small hysteresis and negligible heel) as well as the fastest absorption kinetics of the materials tested. NdCo3 also has good cycling and oxygen stability. As with most intermetallic alloys, NdCo3 decrepitates into a fine powder after only a few sorption cycles in hydrogen and therefore must be consolidated in order to be used in the fixed bed absorber envisioned for the inert gas separation process. Consolidation was achieved through support of the NdCo3 in a sinter-bonded aluminum matrix. Stable compacts of NdCo3 have been made consisting of 40 wt.% Al in NdCo3 pellets, pressed at 186 MPa and sintered under vacuum for 2 h at 450-degrees-C. These compacts retained the full absorptive capacity of NdCo3 and remained 99 wt.% intact after 15 sorption cycles in hydrogen. RP FISHER, IA (reprint author), WESTINGHOUSE SAVANNAH RIVER CO,SAVANNAH RIVER LAB,AIKEN,SC 29808, USA. NR 10 TC 1 Z9 1 U1 0 U2 1 PU ELSEVIER SCIENCE SA LAUSANNE PI LAUSANNE 1 PA PO BOX 564, 1001 LAUSANNE 1, SWITZERLAND SN 0022-5088 J9 J LESS-COMMON MET PD SEP 10 PY 1991 VL 172 BP 1320 EP 1330 DI 10.1016/S0022-5088(06)80042-1 PN C PG 11 WC Chemistry, Physical; Metallurgy & Metallurgical Engineering SC Chemistry; Metallurgy & Metallurgical Engineering GA GK510 UT WOS:A1991GK51000042 ER PT J AU CARSTENS, DHW ENCINIAS, PD AF CARSTENS, DHW ENCINIAS, PD TI HYDROGEN ISOTOPIC EXCHANGE IN PALLADIUM HYDRIDE SO JOURNAL OF THE LESS-COMMON METALS LA English DT Article; Proceedings Paper CT INTERNATIONAL SYMP ON METAL-HYDROGEN SYSTEMS, FUNDAMENTALS AND APPLICATIONS CY SEP 02-07, 1990 CL BANFF, CANADA ID EQUILIBRIUM; KINETICS; SYSTEMS; ABSORPTION; SEPARATION; VANADIUM; TRITIUM; METALS; GAS AB We have recently developed the laser-Raman technique as a means of unambiguously measuring the partial pressures of all possible hydrogen isotopes in the gas phase. Using this technique we have investigated the hydrogen-deuterium solid-phase exchange in a number of metal hydrides. Note that the exchange process we are discussing is a complete conversion of a metal hydride to the deuteride and back by successive reaction with first hydrogen and then deuterium. This report presents detailed data for isotopic exchange in the palladium hydride system over the temperature range from 26 to -100-degrees-C at a pressure of 7 atm. First-order kinetic rate constants and activation energies are summarized for the forward (hydride to deuteride) and reverse (deuteride to hydride) exchange processes. In addition, we have found that small amounts (100 p.p.m.) of impurities in the exchange gases considerably slow the exchange kinetics with the effect increasing down the series CH4, CO2, H2O and CO. RP CARSTENS, DHW (reprint author), UNIV CALIF LOS ALAMOS SCI LAB,LOS ALAMOS,NM 87545, USA. NR 31 TC 9 Z9 10 U1 0 U2 5 PU ELSEVIER SCIENCE SA LAUSANNE PI LAUSANNE 1 PA PO BOX 564, 1001 LAUSANNE 1, SWITZERLAND SN 0022-5088 J9 J LESS-COMMON MET PD SEP 10 PY 1991 VL 172 BP 1331 EP 1337 DI 10.1016/S0022-5088(06)80043-3 PN C PG 7 WC Chemistry, Physical; Metallurgy & Metallurgical Engineering SC Chemistry; Metallurgy & Metallurgical Engineering GA GK510 UT WOS:A1991GK51000043 ER PT J AU NOBILE, A WALTERS, RT MOSLEY, WC AF NOBILE, A WALTERS, RT MOSLEY, WC TI EFFECTS OF RADIOLYTIC TRITIUM DECAY ON THE THERMODYNAMIC BEHAVIOR OF LANI4.25AL0.75 TRITIDES SO JOURNAL OF THE LESS-COMMON METALS LA English DT Article; Proceedings Paper CT INTERNATIONAL SYMP ON METAL-HYDROGEN SYSTEMS, FUNDAMENTALS AND APPLICATIONS CY SEP 02-07, 1990 CL BANFF, CANADA ID HYDRIDES AB Intermetallic compounds which react with hydrogen isotopes to form reversible hydrides offer several advantages for storing and processing tritium. Advantages include safe, low pressure, high density storage, and delivery of high purity He-3-free tritium without the use of pumps. As part of a program to develop metal hydride technology for storing and processing tritium, the effects of tritium aging on the thermodynamic behavior of the tritides are under investigation. During aging of LaNi4.25Al0.75 tritides, the He-3 decay product of tritium produced in the lattice does not leave the lattice but causes changes in the thermodynamics of the gas-solid system. Among the changes noted are (1) decreased tritium desorption pressures, (2) increased slopes of desorption isotherm plateaux and (3) small quantities of irreversibly-held tritium. Absorption-desorption cycling and brief heating of samples to 350-degrees-C while loaded with deuterium partially reverses these effects. While the desorption isotherms of tritium-aged LaNi4.25Al0.75 tritides resemble the desorption isotherms of amorphous hydrogen storage materials, X-ray diffraction patterns of tritium-aged samples after desorption of tritium do not exhibit the characteristics of an amorphous material. The diffraction patterns show broadening and anisotropic effects that suggest the presence of lattice strains and orientational effects of He-3 in the LaNi4.25Al0.75 lattice. Self-interstitials, dislocations and bubbles are probably present in the aged samples. RP NOBILE, A (reprint author), WESTINGHOUSE SAVANNAH RIVER CO,SAVANNAH RIVER LAB,AIKEN,SC 29808, USA. NR 8 TC 16 Z9 22 U1 4 U2 5 PU ELSEVIER SCIENCE SA LAUSANNE PI LAUSANNE 1 PA PO BOX 564, 1001 LAUSANNE 1, SWITZERLAND SN 0022-5088 J9 J LESS-COMMON MET PD SEP 10 PY 1991 VL 172 BP 1352 EP 1362 DI 10.1016/S0022-5088(06)80046-9 PN C PG 11 WC Chemistry, Physical; Metallurgy & Metallurgical Engineering SC Chemistry; Metallurgy & Metallurgical Engineering GA GK510 UT WOS:A1991GK51000046 ER PT J AU SWITENDICK, AC AF SWITENDICK, AC TI ELECTRONIC-STRUCTURE AND STABILITY OF PALLADIUM HYDROGEN (DEUTERIUM) SYSTEMS, PDH(D)N, 1 LESS-THAN-OR-EQUAL-TO N LESS-THAN-OR-EQUAL-TO 3 SO JOURNAL OF THE LESS-COMMON METALS LA English DT Article; Proceedings Paper CT INTERNATIONAL SYMP ON METAL-HYDROGEN SYSTEMS, FUNDAMENTALS AND APPLICATIONS CY SEP 02-07, 1990 CL BANFF, CANADA ID COLD FUSION; ATOMS AB Total energy calculations as a function of lattice constant were performed for PdH, PdH2 and PdH3. Earlier calculations (A. C. Switendick, J. Less-Common Met., 130 (1987) 249) for PdH2 are corrected. The addition of hydrogen expands and hardens the lattice. Only PdH forms a stable hydride. Hydrogen-hydrogen separations greatly exceed those of the hydrogen molecule. RP SWITENDICK, AC (reprint author), SANDIA NATL LABS,ALBUQUERQUE,NM 87185, USA. NR 21 TC 2 Z9 2 U1 2 U2 5 PU ELSEVIER SCIENCE SA LAUSANNE PI LAUSANNE 1 PA PO BOX 564, 1001 LAUSANNE 1, SWITZERLAND SN 0022-5088 J9 J LESS-COMMON MET PD SEP 10 PY 1991 VL 172 BP 1363 EP 1370 DI 10.1016/S0022-5088(06)80047-0 PN C PG 8 WC Chemistry, Physical; Metallurgy & Metallurgical Engineering SC Chemistry; Metallurgy & Metallurgical Engineering GA GK510 UT WOS:A1991GK51000047 ER PT J AU FOLTYN, SR MUENCHAUSEN, RE DYE, RC WU, XD LUO, L COOKE, DW TABER, RC AF FOLTYN, SR MUENCHAUSEN, RE DYE, RC WU, XD LUO, L COOKE, DW TABER, RC TI LARGE-AREA, 2-SIDED SUPERCONDUCTING YBA2CU3O7-X FILMS DEPOSITED BY PULSED LASER DEPOSITION SO APPLIED PHYSICS LETTERS LA English DT Article AB The in situ excimer-laser deposition process is demonstrated, for the first time, to be an effective technique for producing superconducting films on both sides of substrate wafers of up to 5 cm in diameter. By exploiting the directed nature of the laser produced plume and controlling its off-axis composition, thickness and stoichiometric variations of less than +/- 5% have been obtained over the entire surface. Coatings on 5-cm-diam LaAlO3 substrates have uniform transition temperatures of greater-than-or-equal-to 90 K on both sides, with a critical current density at 77 K and zero field of 2.5 x 10(6) A/cm2. The 10 GHz surface resistance for samples cut from a 5 cm wafer is 40-60-mu-OMEGA at 4 K. C1 HEWLETT PACKARD CO,PALO ALTO,CA 94303. RP FOLTYN, SR (reprint author), UNIV CALIF LOS ALAMOS SCI LAB,CTR EXPLORATORY RES & DEV,LOS ALAMOS,NM 87545, USA. NR 8 TC 75 Z9 75 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 SEP 9 PY 1991 VL 59 IS 11 BP 1374 EP 1376 DI 10.1063/1.105313 PG 3 WC Physics, Applied SC Physics GA GD982 UT WOS:A1991GD98200036 ER PT J AU COX, JL AF COX, JL TI UNIVERSAL SYMBOL FOR CHEMICALS SO CHEMICAL & ENGINEERING NEWS LA English DT Letter RP COX, JL (reprint author), PACIFIC NW LAB, CHEM PROC DEV SECT, RICHLAND, WA 99352 USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 SN 0009-2347 J9 CHEM ENG NEWS JI Chem. Eng. News PD SEP 9 PY 1991 VL 69 IS 36 BP 2 EP 2 PG 1 WC Chemistry, Multidisciplinary; Engineering, Chemical SC Chemistry; Engineering GA GD986 UT WOS:A1991GD98600001 ER PT J AU WEST, GB AF WEST, GB TI ASYMPTOTIC ESTIMATE OF THE N-LOOP QCD CONTRIBUTION TO THE TOTAL E+E- ANNIHILATION CROSS-SECTION SO PHYSICAL REVIEW LETTERS LA English DT Article ID QUANTUM-CHROMODYNAMIC CORRECTIONS AB A technique for estimating the large-order QCD perturbative contributions to the total e+e- total cross section is presented which is based upon the renormalization group and momentum analyticity. Our estimate for the coefficient of (alpha-s/pi)3 has recently been confirmed by two exact calculations. We find that the effective expansion parameter is, in fact, not alpha-s/pi but rather 4-pi-2eb1(alpha-s/pi), where b1 is the first coefficient in the expansion of the beta-function. RP WEST, GB (reprint author), UNIV CALIF LOS ALAMOS SCI LAB,DIV THEORET,T-8,MS B285,LOS ALAMOS,NM 87545, USA. NR 13 TC 36 Z9 36 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 SEP 9 PY 1991 VL 67 IS 11 BP 1388 EP 1391 DI 10.1103/PhysRevLett.67.1388 PG 4 WC Physics, Multidisciplinary SC Physics GA GD965 UT WOS:A1991GD96500005 ER PT J AU GIBBS, WR HAYES, AC AF GIBBS, WR HAYES, AC TI DETERMINATION OF THE RADIUS OF THE LI-11 NEUTRON HALO FROM PION DOUBLE CHARGE-EXCHANGE SO PHYSICAL REVIEW LETTERS LA English DT Article ID INTERACTION CROSS-SECTIONS; NUCLEAR RADII; LIGHT-NUCLEI AB We have analyzed the pion-induced double-charge-exchange data for the direct population of the ground state of Li-11 by the B-11(pi-,pi+) Li-11 reaction. We find that the measured cross section determines the rms radius of the last two neutrons in Li-11 to be 5.1(-0.9)+0.6 fm, which corresponds to a total neutron rms radius for the nucleus of 3.28(-0.33)+0.24 fm. We show that for large assumed neutron-halo radii the cross section decreases as the radius of the halo to the inverse sixth power and that a radius of 12 fm leads to a cross section which is 3 orders of magnitude smaller than that measured. C1 UNIV CALIF LOS ALAMOS SCI LAB,DIV THEORET,LOS ALAMOS,NM 87545. NR 15 TC 30 Z9 30 U1 0 U2 0 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 0031-9007 J9 PHYS REV LETT JI Phys. Rev. Lett. PD SEP 9 PY 1991 VL 67 IS 11 BP 1395 EP 1398 DI 10.1103/PhysRevLett.67.1395 PG 4 WC Physics, Multidisciplinary SC Physics GA GD965 UT WOS:A1991GD96500007 ER PT J AU CHIAO, RY DEUTSCH, IH GARRISON, JC AF CHIAO, RY DEUTSCH, IH GARRISON, JC TI 2-PHOTON BOUND-STATE IN SELF-FOCUSING MEDIA SO PHYSICAL REVIEW LETTERS LA English DT Article ID QUANTUM-FIELD THEORY; PARAMETRIC-AMPLIFIER; LIGHT-PROPAGATION; SODIUM VAPOR; SOLITONS AB We derive a two-photon bound-state solution to the problem of quantum propagation of light in Kerr-effect nonlinear media which classically would exhibit self-focusing and self-trapping. We propose an experiment to see this two-photon bound state. C1 UNIV CALIF LAWRENCE LIVERMORE NATL LAB,LIVERMORE,CA 94550. RP CHIAO, RY (reprint author), UNIV CALIF BERKELEY,DEPT PHYS,BERKELEY,CA 94720, USA. RI Deutsch, Ivan/D-1882-2009 OI Deutsch, Ivan/0000-0002-1733-5750 NR 31 TC 24 Z9 24 U1 0 U2 4 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 0031-9007 J9 PHYS REV LETT JI Phys. Rev. Lett. PD SEP 9 PY 1991 VL 67 IS 11 BP 1399 EP 1402 DI 10.1103/PhysRevLett.67.1399 PG 4 WC Physics, Multidisciplinary SC Physics GA GD965 UT WOS:A1991GD96500008 ER PT J AU DING, YG CHAN, CT HO, KM AF DING, YG CHAN, CT HO, KM TI STRUCTURE OF THE (SQUARE-ROOT-OF-3 X SQUARE-ROOT-OF-3)R30-DEGREES AG/SI(111) SURFACE FROM 1ST-PRINCIPLES CALCULATIONS SO PHYSICAL REVIEW LETTERS LA English DT Article ID SCANNING TUNNELING MICROSCOPY; ION-SCATTERING; SQUARE-ROOT-3-AG SURFACE; SI(111) SURFACE; ELECTROREFLECTANCE SPECTROSCOPY; ELECTRONIC-STRUCTURE; RAY-DIFFRACTION; AG; INTERFACE; STATES AB The structure of (square-root 3 x square-root 3) Ag/Si(111) is investigated using first-principles total-energy calculations. The lowest-energy configuration consists of a top layer of Ag atoms arranged as "honeycomb chained trimers" lying above a distorted "missing-top-layer" Si(111) substrate. We find that the honeycomb structure observed in scanning-tunneling-microscope images arises from the electronic charge density of an empty surface band near the Fermi level. C1 IOWA STATE UNIV SCI & TECHNOL,DEPT PHYS,AMES,IA 50011. RP DING, YG (reprint author), IOWA STATE UNIV SCI & TECHNOL,US DOE,AMES LAB,AMES,IA 50011, USA. NR 45 TC 170 Z9 171 U1 1 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 SEP 9 PY 1991 VL 67 IS 11 BP 1454 EP 1457 DI 10.1103/PhysRevLett.67.1454 PG 4 WC Physics, Multidisciplinary SC Physics GA GD965 UT WOS:A1991GD96500022 ER PT J AU HEINEY, PA FISCHER, JE MCGHIE, AR ROMANOW, WA DENENSTEIN, AM MCCAULEY, JP SMITH, AB COX, DE AF HEINEY, PA FISCHER, JE MCGHIE, AR ROMANOW, WA DENENSTEIN, AM MCCAULEY, JP SMITH, AB COX, DE TI ORIENTATIONAL ORDERING TRANSITION IN SOLID C-60 - REPLY SO PHYSICAL REVIEW LETTERS LA English DT Letter C1 UNIV PENN,DEPT MAT SCI,PHILADELPHIA,PA 19104. UNIV PENN,RES STRUCT MATTER LAB,PHILADELPHIA,PA 19104. UNIV PENN,DEPT CHEM,PHILADELPHIA,PA 19104. BROOKHAVEN NATL LAB,UPTON,NY 11973. RP HEINEY, PA (reprint author), UNIV PENN,DEPT PHYS,PHILADELPHIA,PA 19104, USA. NR 4 TC 63 Z9 63 U1 0 U2 8 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 0031-9007 J9 PHYS REV LETT JI Phys. Rev. Lett. PD SEP 9 PY 1991 VL 67 IS 11 BP 1468 EP 1468 DI 10.1103/PhysRevLett.67.1468 PG 1 WC Physics, Multidisciplinary SC Physics GA GD965 UT WOS:A1991GD96500027 ER PT J AU WANG, J AF WANG, J TI VIBRATION OF STEPPED BEAMS ON ELASTIC FOUNDATIONS SO JOURNAL OF SOUND AND VIBRATION LA English DT Letter RP WANG, J (reprint author), ARGONNE NATL LAB,DIV MAT & COMPONENTS TECHNOL,ARGONNE,IL 60439, USA. NR 6 TC 8 Z9 9 U1 0 U2 1 PU ACADEMIC PRESS LTD PI LONDON PA 24-28 OVAL RD, LONDON, ENGLAND NW1 7DX SN 0022-460X J9 J SOUND VIB JI J. Sound Vibr. PD SEP 8 PY 1991 VL 149 IS 2 BP 315 EP 322 DI 10.1016/0022-460X(91)90640-6 PG 8 WC Acoustics; Engineering, Mechanical; Mechanics SC Acoustics; Engineering; Mechanics GA GF816 UT WOS:A1991GF81600011 ER PT J AU NOURBAKHSH, S YIN, HM LIAO, CL NG, CY AF NOURBAKHSH, S YIN, HM LIAO, CL NG, CY TI A 193 NM LASER PHOTOFRAGMENTATION TIME-OF-FLIGHT MASS-SPECTROMETRIC STUDY OF CH3CH2SH SO CHEMICAL PHYSICS LETTERS LA English DT Article ID DISSOCIATION; CH3SSCH3; RADICALS; H2S AB The kinetic energy releases of the photodissociation processes, CH3CH2SH + hv (193 nm) --> CH3CH2 + SH, CH3CH2S + H, and CH3 + CH2SH, have been measured by the time-of-flight mass spectrometric method. Based on the thresholds of kinetic energy spectra, the dissociation energies of 72.4 +/- 1.5, 90 +/- 2, and 90 +/- 10 kcal/mol have been obtained for the CH3CH2-SH, CH3CH2SH, and CH3-CH2SH bonds at 0 K. C1 IOWA STATE UNIV SCI & TECHNOL,DEPT CHEM,AMES,IA 50011. DALIAN INST CHEM PHYS,DALIAN,PEOPLES R CHINA. RP NOURBAKHSH, S (reprint author), US DOE,AMES LAB,AMES,IA 50011, USA. NR 20 TC 11 Z9 11 U1 2 U2 2 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0009-2614 J9 CHEM PHYS LETT JI Chem. Phys. Lett. PD SEP 6 PY 1991 VL 183 IS 5 BP 348 EP 352 DI 10.1016/0009-2614(91)90391-L PG 5 WC Chemistry, Physical; Physics, Atomic, Molecular & Chemical SC Chemistry; Physics GA GF695 UT WOS:A1991GF69500006 ER PT J AU MENEZES, WJC KNICKELBEIN, MB AF MENEZES, WJC KNICKELBEIN, MB TI BIMETALLIC CLUSTERS OF COBALT AND ALUMINUM - IONIZATION-POTENTIALS VERSUS REACTIVITY, AND THE IMPORTANCE OF GEOMETRIC STRUCTURE SO CHEMICAL PHYSICS LETTERS LA English DT Article ID METAL-CLUSTERS; PHOTOIONIZATION; CHEMISTRY; SURFACES; POTASSIUM; HYDROGEN AB We report the determination of the ionization potentials for unsupported bimetallic clusters of cobalt and aluminum by photoionization spectroscopy. A comparison of these values to the hydrogen chemisorption rate constants reported by Nonose et al. (Chem. Phys. Letters 164 (1989) 427), reveals no correlation or anticorrelation, underscoring the importance of cluster geometric structure in determining reactivity. RP MENEZES, WJC (reprint author), ARGONNE NATL LAB, DIV CHEM, ARGONNE, IL 60439 USA. NR 24 TC 34 Z9 36 U1 0 U2 1 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0009-2614 EI 1873-4448 J9 CHEM PHYS LETT JI Chem. Phys. Lett. PD SEP 6 PY 1991 VL 183 IS 5 BP 357 EP 362 DI 10.1016/0009-2614(91)90393-N PG 6 WC Chemistry, Physical; Physics, Atomic, Molecular & Chemical SC Chemistry; Physics GA GF695 UT WOS:A1991GF69500008 ER PT J AU KATTI, AM CZOK, M GUIOCHON, G AF KATTI, AM CZOK, M GUIOCHON, G TI PREDICTION OF SINGLE AND BINARY PROFILES IN OVERLOADED ELUTION CHROMATOGRAPHY USING VARIOUS SEMI-IDEAL MODELS SO JOURNAL OF CHROMATOGRAPHY LA English DT Article ID NONLINEAR LIQUID-CHROMATOGRAPHY; BAND PROFILES; NUMERICAL-SIMULATION; PROPAGATION; SEPARATION; ISOTHERMS AB Experimental band profiles of 2-phenylethanol and 3-phenylpropanol were recorded for pure components in different amounts and for binary mixtures at different compositions in reversed-phase chromatography. The injection function was also measured. These experimental profiles are compared with those calculated using different finite difference methods (i.e., the Craig and Rouchon et al. models). The results show that it is important to take into account the true injection profile. The different calculation procedures in most instances give profiles which are in close agreement with the experimental data. The Craig model gives profiles which are generally sharper than those given by the Rouchon et al. model. Differences between the experimental and calculated profiles are ascribed to mathematical properties of the method implemented. C1 UNIV TENNESSEE,DEPT CHEM,KNOXVILLE,TN 37996. UNIV TENNESSEE,DEPT CHEM ENGN,KNOXVILLE,TN 37996. OAK RIDGE NATL LAB,DIV ANALYT CHEM,OAK RIDGE,TN 37831. OI Souce, Martin/0000-0002-6627-9660 NR 25 TC 21 Z9 21 U1 1 U2 3 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0021-9673 J9 J CHROMATOGR PD SEP 6 PY 1991 VL 556 IS 1-2 BP 205 EP 218 DI 10.1016/S0021-9673(01)96222-3 PG 14 WC Chemistry, Analytical SC Chemistry GA GG802 UT WOS:A1991GG80200013 ER PT J AU BESMANN, TM SHELDON, BW LOWDEN, RA STINTON, DP AF BESMANN, TM SHELDON, BW LOWDEN, RA STINTON, DP TI VAPOR-PHASE FABRICATION AND PROPERTIES OF CONTINUOUS-FILAMENT CERAMIC COMPOSITES SO SCIENCE LA English DT Article ID GAS-SOLID REACTIONS; INFILTRATION; DEPOSITION; KINETICS; FIBERS; CARBON; MODEL AB The continuous-filament ceramic composite is becoming recognized as necessary for new, high-temperature structural applications. Yet because of the susceptibility of the filaments to damage from traditional methods for the preparation of ceramics, vapor-phase infiltration has become the fabrication method of choice. The chemical vapor infiltration methods for producing these composites are now being studied in earnest, with the complexity of filament weaves and deposition chemistry being merged with standard heat and mass-transport relationships. Two of the most influential effects on the mechanical properties of these materials are the adhesion and frictional force between the fibers and the matrix, which can be controlled by a tailored interface coating. A variety of materials are available for producing these composites including carbide, nitride, boride, and oxide filaments and matrices. Silicon carbide-based materials are by far the most advanced and are already being used in aerospace applications. RP BESMANN, TM (reprint author), OAK RIDGE NATL LAB, POB 2008, OAK RIDGE, TN 37831 USA. NR 40 TC 221 Z9 230 U1 7 U2 42 PU AMER ASSOC ADVANCEMENT SCIENCE PI WASHINGTON PA 1200 NEW YORK AVE, NW, WASHINGTON, DC 20005 USA SN 0036-8075 J9 SCIENCE JI Science PD SEP 6 PY 1991 VL 253 IS 5024 BP 1104 EP 1109 DI 10.1126/science.253.5024.1104 PG 6 WC Multidisciplinary Sciences SC Science & Technology - Other Topics GA GD808 UT WOS:A1991GD80800023 PM 17731807 ER PT J AU VALLIER, TL JENNER, GA FREY, FA GILL, JB DAVIS, AS VOLPE, AM HAWKINS, JW MORRIS, JD CAWOOD, PA MORTON, JL SCHOLL, DW RAUTENSCHLEIN, M WHITE, WM WILLIAMS, RW STEVENSON, AJ WHITE, LD AF VALLIER, TL JENNER, GA FREY, FA GILL, JB DAVIS, AS VOLPE, AM HAWKINS, JW MORRIS, JD CAWOOD, PA MORTON, JL SCHOLL, DW RAUTENSCHLEIN, M WHITE, WM WILLIAMS, RW STEVENSON, AJ WHITE, LD TI SUBALKALINE ANDESITE FROM VALU FA RIDGE, A BACK-ARC SPREADING CENTER IN SOUTHERN LAU BASIN - PETROGENESIS, COMPARATIVE CHEMISTRY, AND TECTONIC IMPLICATIONS SO CHEMICAL GEOLOGY LA English DT Article ID ND ISOTOPIC EVIDENCE; OCEANIC ISLAND ARCS; TRACE-ELEMENT; VOLCANIC-ROCKS; MARGINAL BASINS; MAGNETIC-ANOMALIES; SOUTHWEST PACIFIC; MANTLE EVOLUTION; MAGMA FORMATION; NEW-ZEALAND AB Tholeiitic andesite was dredged from two sites on Valu Fa Ridge (VFR), a back-arc spreading center in Lau Basin. Valu Fa Ridge, at least 200 km long, is located 40-50 km west of the active Tofua Volcanic Arc (TVA) axis and lies about 150 km above the subducted oceanic plate. One or more magma chambers, traced discontinuously for about 100 km along the ridge axis, lie 3-4 km beneath the ridge. The mostly aphyric and glassy lavas had high volatile contents, as shown by the abundance and large sizes of vesicles. An extensive fractionation history is inferred from the high SiO2 contents and FeO*/MgO ratios. Chemical data show that the VFR lavas have both volcanic arc and back-arc basin affinities. The volcanic arc characteristics are: (1) relatively high abundances of most alkali and alkaline earth elements; (2) low abundances of high field strength elements Nb and Ta; (3) high U/Th ratios; (4) similar radiogenic isotope ratios in VFR and TVA lavas, in particular the enrichment of Sr-87/Sr-86 relative to Pb-206/Pb-204; (5) high U-238/Th-230, Th-230/Th-232, and Ra-226/Th-230 activity ratios; and (6) high ratios of Rb/Cs, Ba/Nb, and Ba/La. Other chemical characteristics suggest that the VFR lavas are related to MORB-type back-arc basin lavas. For example, VFR lavas have (1) lower Sr-87/Sr-86 ratios and higher Nd-143/Nd-144 ratios than most lavas from the TVA, except samples from Ata Island, and are similar to many Lau Basin lavas; (2) lower Sr/REE, Rb/Zr, and Ba/Zr ratios than in arc lavas; and (3) higher Ti, Fe, and V, and higher Ti/V ratios than arc lavas generally and TVA lavas specifically. Most characteristics of VFR lavas can be explained by mixing depleted mantle with either small amounts of sediment and fluids from the subducting slab and/or an older fragment of volcanic arc lithosphere. The eruption of subalkaline andesite with some arc affinities along a back-arc spreading ridge is not unique. Collision of the Louisville and Tonga ridges probably activated back-arc extension that ultimately led to the creation and growth of Valu Fa Ridge. Some ophiolitic fragments in circum-Pacific and circum-Tethyan allochthonous terranes, presently interpreted to have originated in volcanic arcs, may instead be fragments of lithosphere that formed during early stages of sea-floor spreading in a back-arc basin. C1 MIT,CAMBRIDGE,MA 02139. UNIV CALIF SANTA CRUZ,SANTA CRUZ,CA 95064. UNIV CALIF LOS ALAMOS SCI LAB,LOS ALAMOS,NM 87544. UNIV CALIF SAN DIEGO,SCRIPPS INST OCEANOG,LA JOLLA,CA 92093. MAX PLANCK INST,MAINZ,GERMANY. CARNEGIE INST WASHINGTON,WASHINGTON,DC 20005. MAX PLANCK INST,ITHACA,NY. MEM UNIV NEWFOUNDLAND,ST JOHNS A1C 5S7,NEWFOUNDLAND,CANADA. CORNELL UNIV,ITHACA,NY 14853. RP VALLIER, TL (reprint author), US GEOL SURVEY,345 MIDDLEFIELD RD,MENLO PK,CA 94025, USA. RI White, William/N-3231-2014; OI White, William/0000-0001-9024-7039; Frey, Frederick/0000-0002-5403-5677 NR 96 TC 76 Z9 76 U1 0 U2 5 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0009-2541 J9 CHEM GEOL JI Chem. Geol. PD SEP 5 PY 1991 VL 91 IS 3 BP 227 EP 256 DI 10.1016/0009-2541(91)90002-9 PG 30 WC Geochemistry & Geophysics SC Geochemistry & Geophysics GA GH939 UT WOS:A1991GH93900002 ER PT J AU MYATT, EA STEVENS, FJ SIGLER, PB AF MYATT, EA STEVENS, FJ SIGLER, PB TI EFFECTS OF PH AND CALCIUM-ION ON SELF-ASSOCIATION PROPERTIES OF 2 DIMERIC PHOSPHOLIPASES-A2 SO JOURNAL OF BIOLOGICAL CHEMISTRY LA English DT Article ID PERFORMANCE LIQUID-CHROMATOGRAPHY; SIZE-EXCLUSION CHROMATOGRAPHY; PROTEIN PROTEIN-INTERACTION; PANCREATIC PHOSPHOLIPASE-A2; CROTALUS-ATROX; SIMULATION AB The monomer-dimer equilibria of the dimeric phospholipases A2 from Crotalus atrox and Agkistrodon piscivorus piscivorus venoms were examined chromatographically as a function of pH and in the presence versus absence of the essential cofactor, calcium ion. At neutral pH without calcium, the subunits of both enzymes reequilibrated sufficiently slowly that dimer and monomer were separated by size exclusion chromatography. At pH 4.2 and lower, the dimers underwent rapid dissociation and reassociation, eluting as single broad peaks whose position as a function of applied protein concentration could be analyzed to determine association constants using an algorithm that estimates these values based on elution positions. Lowering the pH from 7.0 to 4.2 increased the self-association constant of the C. atrox enzyme by 1 order of magnitude and that of the A. p. piscivorus dimer by a factor of 3. Calcium ion, an essential cofactor of phospholipase A2, converted the kinetic behavior of the dimers at neutral pH from slow to virtually instantaneous on the time scale of the chromatography runs, 40 min. Calcium ion also altered the thermodynamic stability of the enzymes; the association constant of A. p. piscivorus phospholipase A2 in neutral pH buffer was reduced by approximately 2 orders of magnitude, whereas that of C. atrox was increased by a factor of 6. The structural basis for the disparate effects of calcium ion on these two acidic, dimeric venom phospholipases A2 is uncertain. This study illustrates the importance of calcium ion and pH on the solution behavior of the dimeric members of this class of enzymes. C1 UNIV CHICAGO, DEPT BIOCHEM & MOLEC BIOL, CHICAGO, IL 60637 USA. RP ARGONNE NATL LAB, DIV BIOL & MED RES, 9700 S CASS AVE, ARGONNE, IL 60439 USA. FU NHLBI NIH HHS [T32HL7237]; NIGMS NIH HHS [GM22324] NR 16 TC 15 Z9 15 U1 0 U2 0 PU AMER SOC BIOCHEMISTRY MOLECULAR BIOLOGY INC PI BETHESDA PA 9650 ROCKVILLE PIKE, BETHESDA, MD 20814-3996 USA SN 0021-9258 EI 1083-351X J9 J BIOL CHEM JI J. Biol. Chem. PD SEP 5 PY 1991 VL 266 IS 25 BP 16331 EP 16335 PG 5 WC Biochemistry & Molecular Biology SC Biochemistry & Molecular Biology GA GD635 UT WOS:A1991GD63500017 PM 1885568 ER PT J AU JANCARIK, J SCOTT, WG MILLIGAN, DL KOSHLAND, DE KIM, SH AF JANCARIK, J SCOTT, WG MILLIGAN, DL KOSHLAND, DE KIM, SH TI CRYSTALLIZATION AND PRELIMINARY-X-RAY DIFFRACTION STUDY OF THE LIGAND-BINDING DOMAIN OF THE BACTERIAL CHEMOTAXIS-MEDIATING ASPARTATE RECEPTOR OF SALMONELLA-TYPHIMURIUM SO JOURNAL OF MOLECULAR BIOLOGY LA English DT Note DE ASPARTATE; CHEMOTAXIS; LIGAND-BINDING; RECEPTOR; TRANSMEMBRANE ID DIRECTED CROSS-LINKING; HUMAN INSULIN-RECEPTOR; ESCHERICHIA-COLI; EXPRESSION; PROTEIN; TRANSDUCTION; ADAPTATION C1 UNIV CALIF BERKELEY LAWRENCE BERKELEY LAB,BERKELEY,CA 94720. UNIV CALIF BERKELEY,DEPT MOLEC & CELL BIOL,BERKELEY,CA 94720. RP JANCARIK, J (reprint author), UNIV CALIF BERKELEY,DEPT CHEM,BERKELEY,CA 94720, USA. NR 17 TC 59 Z9 59 U1 0 U2 1 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 SEP 5 PY 1991 VL 221 IS 1 BP 31 EP 34 DI 10.1016/0022-2836(91)90798-B PG 4 WC Biochemistry & Molecular Biology SC Biochemistry & Molecular Biology GA GG372 UT WOS:A1991GG37200005 PM 1656050 ER PT J AU JOHNSON, E FRICKE, B AF JOHNSON, E FRICKE, B TI PREDICTION OF SOME THERMODYNAMIC PROPERTIES OF SELECTED COMPOUNDS OF ELEMENT-104 SO JOURNAL OF PHYSICAL CHEMISTRY LA English DT Article ID STANDARD ELECTRODE-POTENTIALS; AQUO IONS; 298.15-K; RADII AB A set of parametrized equations has been published by Bratsch and Lagowski for calculating thermodynamic properties of the lanthanides, actinides, element 104, and certain related elements. Since these equations were applied to element 104, new values for the first four ionization energies and radii of the ions of charge +1, +2, +3, and +4 have been calculated for this element. The parametrized equations are used here with these new values to calculate some thermodynamic properties of element 104. C1 UNIV KASSEL,DEPT PHYS,W-3500 KASSEL,GERMANY. RP JOHNSON, E (reprint author), OAK RIDGE NATL LAB,DIV CHEM,POB 2008,OAK RIDGE,TN 37831, USA. NR 9 TC 20 Z9 20 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 SEP 5 PY 1991 VL 95 IS 18 BP 7082 EP 7084 DI 10.1021/j100171a067 PG 3 WC Chemistry, Physical SC Chemistry GA GE383 UT WOS:A1991GE38300067 ER PT J AU LEVIATAN, A GINOCCHIO, JN AF LEVIATAN, A GINOCCHIO, JN TI PROTON NEUTRON MODES IN NONAXIAL NUCLEI SO PHYSICS LETTERS B LA English DT Article ID INTERACTING-BOSON MODEL; MIXED-SYMMETRY STATES; COLLECTIVE M1 MODE; CLASSICAL LIMIT; BETA-VIBRATIONS; O(6) LIMIT; EXCITATION; IBA-2 AB A normal-mode analysis is carried out for aligned rigid-triaxial, gamma-unstable and oblique proton-neutron shapes. Intrinsic hamiltonians, energy surfaces and estimates for bandhead energies and selected transition rates are provided. Possible experimental signatures are briefly discussed. C1 UNIV CALIF LOS ALAMOS SCI LAB, DIV THEORET, LOS ALAMOS, NM 87545 USA. RP LEVIATAN, A (reprint author), YALE UNIV, SLOANE PHYS LAB, CTR THEORET PHYS, NEW HAVEN, CT 06511 USA. NR 22 TC 3 Z9 3 U1 0 U2 1 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0370-2693 EI 1873-2445 J9 PHYS LETT B JI Phys. Lett. B PD SEP 5 PY 1991 VL 267 IS 1 BP 7 EP 11 DI 10.1016/0370-2693(91)90514-Q PG 5 WC Astronomy & Astrophysics; Physics, Nuclear; Physics, Particles & Fields SC Astronomy & Astrophysics; Physics GA GG611 UT WOS:A1991GG61100002 ER PT J AU SHI, S DANIELS, LM ESPENSON, JH AF SHI, S DANIELS, LM ESPENSON, JH TI MOLECULAR-STRUCTURE OF A COBALT(I) COMPLEX LACKING A CARBONYL LIGAND - A UNIQUE EXAMPLE OF CO-N BOND SHORTENING SO INORGANIC CHEMISTRY LA English DT Article ID CRYSTAL-STRUCTURE; DERIVATIVES; MECHANISM; ELECTROCHEMISTRY; VITAMIN-B12; CHEMISTRY; EVOLUTION; REDUCTION; HYDROGEN; SYSTEM AB The following compound, [(CH3)4N][Co(dmgBF2)2py], where py = C5H5N and (dmgBF2)2(2-) = bis[(difluoroboryl)dimethyl-glyoximato], was crystallized and its molecular structure determined by X-ray diffraction. The distances between Co(I) and the nitrogen of the macrocycle are unusually short (1.839 angstrom), even shorter than the corresponding bond (1.878 angstrom) in the cobalt(II) analogue. The cobalt atom is displaced 0.257 angstrom above the axial plane toward pyridine. Reasons for this unusual Co-N bond shortening are discussed along with the electronic structure of the d8 cobalt(I) anion. C1 IOWA STATE UNIV SCI & TECHNOL,AMES LAB,AMES,IA 50011. IOWA STATE UNIV SCI & TECHNOL,DEPT CHEM,AMES,IA 50011. NR 49 TC 25 Z9 25 U1 0 U2 2 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 SN 0020-1669 J9 INORG CHEM JI Inorg. Chem. PD SEP 4 PY 1991 VL 30 IS 18 BP 3407 EP 3410 DI 10.1021/ic00018a008 PG 4 WC Chemistry, Inorganic & Nuclear SC Chemistry GA GD841 UT WOS:A1991GD84100008 ER PT J AU SHI, S BAKAC, A ESPENSON, JH AF SHI, S BAKAC, A ESPENSON, JH TI REDUCTION-INDUCED CLEAVAGE OF THE COBALT CARBON BOND IN MACROCYCLIC ORGANOCOBALT COMPLEXES SO INORGANIC CHEMISTRY LA English DT Article ID MODEL; TETRAMETHYLCYCLAM; ELECTROCHEMISTRY; METHYLCOBALAMIN; COENZYME-B12; DERIVATIVES; RESONANCE; LIGANDS; SPIN AB The one-electron reduction of RCo(dmgBF2)2A (dmgBF2 = (difluoroboryl)dimethylglyoximato, A = pyridine or H2O, R = CH3, C2H5, C3H7, C6H5CH2, or 4-XC6H4CH2) yields RCo(dmgBF2)2A- as transients. The ESR parameters (R = 4-BrC6H4CH2, g-parallel-to = 2.23, A-parallel-to = 111 x 10(-4) cm-1, g-perpendicular-to = 2.07, A-perpendicular-to = 54 x 10(-4) cm-1) indicate that the unpaired electron resides in the d(x)2-y2 orbital of the cobalt. The reduced complexes hydrolyze in H2O to yield the alkanes RH and Co(dmgBF2)2(H2O)2. In acetonitrile the decomposition mode depends on the availability of beta-hydrogens. For R = C2H5 and 1-C3H7, the final products are the corresponding alkenes and a cobalt(II) complex of a modified macrocycle. The benzyl and substituted benzyl complexes yield the hydrolysis products 4-XC6H4CH3 and the unchanged cobalt(II) macrocycle. The kinetics of the reduction of RCo(dmgBF2)2A by R,S,-R,S-Ni(tmc)+ (tmc = 1,4,8,11-tetramethyl-1,4,8,11-tetraazacyclotetradecane) in H2O, pH 12, are biphasic for R = benzyl and substituted benzyl and monophasic for the primary alkyl complexes, consistent with the expected effect of the organic group on the lifetimes of the RCo(dmgBF2)2A- transients. C1 IOWA STATE UNIV SCI & TECHNOL,AMES LAB,AMES,IA 50011. IOWA STATE UNIV SCI & TECHNOL,DEPT CHEM,AMES,IA 50011. NR 45 TC 19 Z9 19 U1 1 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 SEP 4 PY 1991 VL 30 IS 18 BP 3410 EP 3414 DI 10.1021/ic00018a009 PG 5 WC Chemistry, Inorganic & Nuclear SC Chemistry GA GD841 UT WOS:A1991GD84100009 ER PT J AU KLANING, UK SEHESTED, K APPELMAN, EH AF KLANING, UK SEHESTED, K APPELMAN, EH TI LASER FLASH-PHOTOLYSIS AND PULSE-RADIOLYSIS OF AQUEOUS-SOLUTIONS OF THE FLUOROXYSULFATE ION, SO4F- SO INORGANIC CHEMISTRY LA English DT Note ID HYDROXYL RADICALS; RATE CONSTANTS; ATOMS; CHLORINE; BROMINE; CL C1 RISO NATL LAB,DK-4000 ROSKILDE,DENMARK. ARGONNE NATL LAB,DIV CHEM,ARGONNE,IL 60439. RP KLANING, UK (reprint author), AARHUS UNIV,DEPT CHEM,DK-8000 AARHUS,DENMARK. NR 20 TC 20 Z9 25 U1 0 U2 1 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 SN 0020-1669 J9 INORG CHEM JI Inorg. Chem. PD SEP 4 PY 1991 VL 30 IS 18 BP 3582 EP 3584 DI 10.1021/ic00018a040 PG 3 WC Chemistry, Inorganic & Nuclear SC Chemistry GA GD841 UT WOS:A1991GD84100040 ER PT J AU MESHINCHI, S STANCATO, LF GORDON, BM JONES, KW PRATT, WB AF MESHINCHI, S STANCATO, LF GORDON, BM JONES, KW PRATT, WB TI PURIFICATION OF THE ENDOGENOUS GLUCOCORTICOID RECEPTOR STABILIZING FACTOR SO BIOCHEMISTRY LA English DT Article ID MOLECULAR WEIGHT INHIBITOR; HEAT-SHOCK PROTEIN; DNA-BINDING STATE; STEROID-RECEPTORS; COMPLEX; TRANSFORMATION; MODULATOR; RECONSTITUTION; ACTIVATION; MOLYBDATE AB A ubiquitous, low molecular weight, heat-stable component of cytosol stabilizes the glucocorticoid receptor in its untransformed state in association with hsp90. This heat-stable factor mimics molybdate in its effects on receptor function, and it has the heat stability, charge, and chelation properties of a metal oxyanion [Meshinchi, S., Grippo, J. F., Sanchez, E. R., Bresnick, E. H., & Pratt, W. B. (1988) J. Biol. Chem. 263, 16809-16817]. In this paper, we describe the further purification of the endogenous factor from rat liver cytosol by anion-exchange HPLC (Ion-110) after prepurification by molecular sieving, cation absorption, and charcoal absorption. Elution of the factor with an isocratic gradient of ammonium bicarbonate results in recovery of all of the bioactivity in a single peak which coelutes with inorganic phosphate and contains all of the endogenous molybdenum. The bioactivity can be separated from inorganic phosphate by chromatography of the partially purified endogenous factor on a metal-chelating column of Chelex-100. The chelating procedure results in complete loss of bioactivity with recovery of 98% of the inorganic phosphate in both the column drop-through and a subsequent 1 M NaCl wash. The factor preparation purified through the Ion-110 HPLC step inhibits temperature-mediated dissociation of the immunopurified glucocorticoid receptor-hsp90 complex, but it is considerably more effective at stabilizing the unpurified receptor-hsp90 complex in a Chelex-treated cytosol system that has been depleted of metal components. These observations support the proposal that an endogenous metal can stabilize the binding of hsp90 to the receptor but it is likely that other cytosolic components that are not present in the immunopurified complex must contribute to the stability of the soluble protein-protein complex in cytosol. C1 UNIV MICHIGAN,SCH MED,DEPT PHARMACOL,ANN ARBOR,MI 48109. BROOKHAVEN NATL LAB,DEPT APPL SCI,UPTON,NY 11973. FU NCRR NIH HHS [P41RR01838]; NIDDK NIH HHS [DK31573] NR 30 TC 17 Z9 17 U1 0 U2 0 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 SN 0006-2960 J9 BIOCHEMISTRY-US JI Biochemistry PD SEP 3 PY 1991 VL 30 IS 35 BP 8617 EP 8622 DI 10.1021/bi00099a018 PG 6 WC Biochemistry & Molecular Biology SC Biochemistry & Molecular Biology GA GD733 UT WOS:A1991GD73300018 PM 1888725 ER PT J AU MORGAN, WL BOERCKER, DB AF MORGAN, WL BOERCKER, DB TI SIMULATING GROWTH OF MO/SI MULTILAYERS SO APPLIED PHYSICS LETTERS LA English DT Article ID MOLECULAR-DYNAMICS SIMULATION; COMPUTER-SIMULATION; EPITAXIAL-GROWTH; SILICON; THERMALIZATION; MOLYBDENUM; SURFACE; MODEL; ATOMS; SI AB Multilayer structures of alternating thin layers of molybdenum and silicon are of great interest as x-ray optics components and a considerable amount of effort has been expended in their development. The efficiencies of these structures depend upon both the accurate control of the layer thicknesses and the sharpness in the interface between layers. High-resolution electron microscopy reveals that the interface created by deposition of Mo on Si is much more diffuse than that produced by depositing Si on Mo. We have used molecular dynamics to simulate the deposition processes and observe significant penetration of the Si substrates by the incident Mo atoms, while incident Si atoms remain on the surface of the Mo substrate. C1 UNIV CALIF LAWRENCE LIVERMORE NATL LAB,LIVERMORE,CA 94550. RP MORGAN, WL (reprint author), KINEMA RES,18720 AUTUMN WAY,MONUMENT,CO 80132, USA. NR 17 TC 34 Z9 34 U1 1 U2 3 PU AMER INST PHYSICS PI WOODBURY PA CIRCULATION FULFILLMENT DIV, 500 SUNNYSIDE BLVD, WOODBURY, NY 11797-2999 SN 0003-6951 J9 APPL PHYS LETT JI Appl. Phys. Lett. PD SEP 2 PY 1991 VL 59 IS 10 BP 1176 EP 1178 DI 10.1063/1.105495 PG 3 WC Physics, Applied SC Physics GA GC958 UT WOS:A1991GC95800013 ER PT J AU LI, MF YU, PY WEBER, ER AF LI, MF YU, PY WEBER, ER TI SIMULATION OF EFFECTS OF UNIAXIAL-STRESS ON THE DEEP LEVEL TRANSIENT SPECTROSCOPY SPECTRA OF THE DX CENTER IN ALGAAS ALLOYS SO APPLIED PHYSICS LETTERS LA English DT Article AB Recently the effect of uniaxial stress on the deep level transient spectroscopy (DLTS) of the DX center in AlGaAs alloys have been reported by two separate groups. In both experiments no splitting of the DLTS peak was observed. We have analyzed the experimental results in terms of a large lattice relaxation model in which the DX center can have either a positive or a negative Coulomb-energy U. We found that if the symmetry of the DX center depended on its charge state then its DLTS peak was not split by uniaxial stress in contrast to other defects with large lattice relaxation (such as the A center in Si). C1 UNIV CALIF BERKELEY,DEPT MANAGEMENT SCI,BERKELEY,CA 94720. UNIV CALIF BERKELEY LAWRENCE BERKELEY LAB,DIV MAT SCI,BERKELEY,CA 94720. RP LI, MF (reprint author), UNIV CALIF BERKELEY,DEPT PHYS,BERKELEY,CA 94720, USA. NR 17 TC 1 Z9 1 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 SEP 2 PY 1991 VL 59 IS 10 BP 1197 EP 1199 DI 10.1063/1.105501 PG 3 WC Physics, Applied SC Physics GA GC958 UT WOS:A1991GC95800020 ER PT J AU FENG, AG CHEN, L PIAZZA, TW LI, HW KALOYEROS, AE HAZELTON, DW LUO, L DYE, RC AF FENG, AG CHEN, L PIAZZA, TW LI, HW KALOYEROS, AE HAZELTON, DW LUO, L DYE, RC TI HIGH-QUALITY Y1BA2CU3O7-X THIN-FILMS ON POLYCRYSTALLINE MGO BY TEMPERATURE-CONTROLLED CHEMICAL VAPOR-DEPOSITION SO APPLIED PHYSICS LETTERS LA English DT Article ID YBA2CU3O7 AB Y1Ba2Cu3O7-x superconducting thin films were grown in situ on polycrystalline MgO substrates by a chemical vapor deposition process that closely couples the sublimation temperatures of the elemental sources to that of the substrate during deposition. It was found that the best quality films were achieved with a controlled ramping of the substrate temperature from 850-degrees-C, at the onset of deposition, down to 750-degrees-C at the end of deposition. The films were analyzed by Rutherford backscattering (RBS), scanning electron microscopy (SEM), x-ray diffractometry (XRD), and four-point resistivity probe. The results of these studies showed that the films were highly c-axis oriented, had near-stoichiometric composition, and exhibited T(c,onset) = 90 K, T(co) = 85 K, and had a J(c) = 2 X 10(5) A/cm2 at 77 K in zero magnetic field. A model is proposed for the effect of such temperature control on the CVD growth mechanism of high-quality YBCO films. C1 INTERMAGNET GEN CORP,GUILDERLAND,NY 12084. UNIV CALIF LOS ALAMOS SCI LAB,CTR MAT SCI,LOS ALAMOS,NM 87545. RP FENG, AG (reprint author), SUNY ALBANY,DEPT PHYS,ALBANY,NY 12222, USA. NR 13 TC 12 Z9 12 U1 0 U2 3 PU AMER INST PHYSICS PI WOODBURY PA CIRCULATION FULFILLMENT DIV, 500 SUNNYSIDE BLVD, WOODBURY, NY 11797-2999 SN 0003-6951 J9 APPL PHYS LETT JI Appl. Phys. Lett. PD SEP 2 PY 1991 VL 59 IS 10 BP 1248 EP 1250 DI 10.1063/1.105517 PG 3 WC Physics, Applied SC Physics GA GC958 UT WOS:A1991GC95800037 ER PT J AU WEINBERG, AM AF WEINBERG, AM TI ORIGINS OF SCIENCE AND TRANSSCIENCE - A CITATION-CLASSIC COMMENTARY ON SCIENCE AND TRANSSCIENCE BY WEINBERG,A.M. SO CURRENT CONTENTS/ARTS & HUMANITIES LA English DT Article RP WEINBERG, AM (reprint author), OAK RIDGE NATL LAB,DIV MED SCI,OAK RIDGE,TN 37831, USA. NR 5 TC 2 Z9 2 U1 0 U2 2 PU INST SCI INFORM INC PI PHILADELPHIA PA 3501 MARKET ST, PHILADELPHIA, PA 19104 SN 0163-3155 J9 CC/ART HUMAN PD SEP 2 PY 1991 IS 18 BP 18 EP 18 PG 1 WC Humanities, Multidisciplinary; Multidisciplinary Sciences SC Arts & Humanities - Other Topics; Science & Technology - Other Topics GA GB067 UT WOS:A1991GB06700001 ER PT J AU CHAKRABORTY, AK SHAFFER, JS ADRIANI, PM AF CHAKRABORTY, AK SHAFFER, JS ADRIANI, PM TI ON THE EXISTENCE OF QUASI-2-DIMENSIONAL GLASSLIKE STRUCTURES AT STRONGLY INTERACTING POLYMER SOLID INTERFACES SO MACROMOLECULES LA English DT Note ID DYNAMICS; ADHESION; MODEL C1 UNIV CALIF BERKELEY,DEPT CHEM ENGN,BERKELEY,CA 94720. RP CHAKRABORTY, AK (reprint author), UNIV CALIF BERKELEY LAWRENCE BERKELEY LAB,CTR ADV MAT,BERKELEY,CA 94720, USA. NR 21 TC 47 Z9 47 U1 1 U2 1 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 SN 0024-9297 J9 MACROMOLECULES JI Macromolecules PD SEP 2 PY 1991 VL 24 IS 18 BP 5226 EP 5229 DI 10.1021/ma00018a033 PG 4 WC Polymer Science SC Polymer Science GA GD714 UT WOS:A1991GD71400033 ER PT J AU DURYEA, J GUGLIELMO, G HELLER, K JOHNS, K SHUPE, M THORNE, K JAMES, C LUK, KB RAMEIKA, R HO, PM LONGO, MJ DIEHL, HT TEIGE, S THOMSON, GB AF DURYEA, J GUGLIELMO, G HELLER, K JOHNS, K SHUPE, M THORNE, K JAMES, C LUK, KB RAMEIKA, R HO, PM LONGO, MJ DIEHL, HT TEIGE, S THOMSON, GB TI POLARIZATION OF =- HYPERONS PRODUCED BY 800-GEV PROTONS SO PHYSICAL REVIEW LETTERS LA English DT Article ID MAGNETIC-MOMENT; INCLUSIVE PRODUCTION; HIGH-ENERGIES; LAMBDA; BERYLLIUM; ASYMMETRY; XI-0 AB The polarization P-XI- of XI- hyperons produced by 800-GeV protons has been measured for x(F) from 0.3 to 0.7 and p(T) from 0.5 to 1.5 GeV/c. P-XI- has a p(T) dependence similar to that of the LAMBDA but has a different x(F) behavior. Also, an energy dependence of P-XI- has been observed. C1 FERMI NATL ACCELERATOR LAB,BATAVIA,IL 60510. UNIV MICHIGAN,DEPT PHYS,ANN ARBOR,MI 48109. RUTGERS STATE UNIV,DEPT PHYS & ASTRON,PISCATAWAY,NJ 08854. RP DURYEA, J (reprint author), UNIV MINNESOTA,SCH PHYS & ASTRON,MINNEAPOLIS,MN 55455, USA. NR 23 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 0031-9007 J9 PHYS REV LETT JI Phys. Rev. Lett. PD SEP 2 PY 1991 VL 67 IS 10 BP 1193 EP 1196 DI 10.1103/PhysRevLett.67.1193 PG 4 WC Physics, Multidisciplinary SC Physics GA GC957 UT WOS:A1991GC95700005 ER PT J AU CHAPMAN, S GYULASSY, M AF CHAPMAN, S GYULASSY, M TI NUCLEAR TRANSPARENCY IN 15A-GEV SI+AU REACTIONS SO PHYSICAL REVIEW LETTERS LA English DT Article ID HEAVY-ION COLLISIONS; STOPPING POWER; MODEL AB Recent data on central Si + Au collisions at 15A GeV are shown to imply an unexpectedly high degree of nuclear transparency. The paucity of observed midrapidity protons and pions suggests that up to one-half of the projectile nucleons may lose less than one unit of rapidity after traversing 5-10 fm of nuclear matter. RP CHAPMAN, S (reprint author), UNIV CALIF BERKELEY LAWRENCE BERKELEY LAB,DIV NUCL SCI,BERKELEY,CA 94720, USA. NR 25 TC 21 Z9 21 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 SEP 2 PY 1991 VL 67 IS 10 BP 1210 EP 1213 DI 10.1103/PhysRevLett.67.1210 PG 4 WC Physics, Multidisciplinary SC Physics GA GC957 UT WOS:A1991GC95700009 ER PT J AU HETTICH, RL COMPTON, RN RITCHIE, RH AF HETTICH, RL COMPTON, RN RITCHIE, RH TI DOUBLY CHARGED NEGATIVE-IONS OF CARBON-60 SO PHYSICAL REVIEW LETTERS LA English DT Article ID C-60; BUCKMINSTERFULLERENE; CLUSTERS; SURFACES; STATES AB We report the observation of long-lived (tau > 10(-3) sec) doubly charged negative ions of C60 in the gas phase. C60- and C60(2-) ions are produced by laser desorption from a surface covered with C60 molecules and are believed to be produced by negative surface ionization from the laser-heated surface. Pseudopotential calculations indicate that C60(2-) is slightly bound (electron affinity of C60- congruent-to 0.1-0.4 eV) relative to C60-. RP HETTICH, RL (reprint author), OAK RIDGE NATL LAB,OAK RIDGE,TN 37831, USA. RI Hettich, Robert/N-1458-2016 OI Hettich, Robert/0000-0001-7708-786X NR 22 TC 198 Z9 198 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 SEP 2 PY 1991 VL 67 IS 10 BP 1242 EP 1245 DI 10.1103/PhysRevLett.67.1242 PG 4 WC Physics, Multidisciplinary SC Physics GA GC957 UT WOS:A1991GC95700017 ER PT J AU KLEIN, W BATROUNI, GG AF KLEIN, W BATROUNI, GG TI SUPERSYMMETRY IN THE CAHN-HILLIARD-COOK THEORY SO PHYSICAL REVIEW LETTERS LA English DT Article ID FIELDS AB We demonstrate that the early stage of spinodal decomposition and continuous ordering is supersymmetric in systems with long-range interactions. Indeed, the Cahn-Hilliard-Cook linear theory can be described equivalently as an evolution of the order parameter (bosons) or objects that obey an exclusion principle (fermions). Coupled with a cluster representation of the Cahn-Hilliard-Cook theory, supersymmetry suggests a new physical picture of the early stage of spinodal decomposition and continuous ordering that provides a greater understanding of early-stage morphology, and could provide a basis for an improved description of the nonlinear regime. C1 BOSTON UNIV,DEPT PHYS,BOSTON,MA 02215. UNIV CALIF LAWRENCE LIVERMORE NATL LAB,LIVERMORE,CA 94550. RP KLEIN, W (reprint author), BOSTON UNIV,CTR POLYMER STUDIES,BOSTON,MA 02215, USA. RI Batrouni, George/A-9318-2009 NR 15 TC 9 Z9 10 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 SEP 2 PY 1991 VL 67 IS 10 BP 1278 EP 1281 DI 10.1103/PhysRevLett.67.1278 PG 4 WC Physics, Multidisciplinary SC Physics GA GC957 UT WOS:A1991GC95700026 ER PT J AU GRAMSCH, E LYNN, KG THROWE, J KANAZAWA, I AF GRAMSCH, E LYNN, KG THROWE, J KANAZAWA, I TI POSITRON DIFFUSION IN SOLID AND LIQUID GA AND BI SO PHYSICAL REVIEW LETTERS LA English DT Article ID SURFACES; METALS AB The diffusion length of positrons in Ga and Bi was measured using a positron beam. For Ga, there is a drop from 1200(100) to 60(5) angstrom upon melting; this is interpreted in terms of creation of centers that trap the positron. As the temperature of the liquid is increased, the diffusion length increases, suggesting that the size of the traps changes. For Bi, the diffusion length decreases from 500(30) to 190(10) angstrom upon melting, and increases slightly as the temperature is increased. This drop is interpreted as increased positron-ion scattering, and not positron trapping as in Ga. C1 TOKYO GAKUGEI UNIV,DEPT PHYS,TOKYO 184,JAPAN. RP GRAMSCH, E (reprint author), BROOKHAVEN NATL LAB,UPTON,NY 11973, USA. OI Gramsch, Ernesto/0000-0002-6787-7355 NR 12 TC 16 Z9 16 U1 0 U2 4 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 0031-9007 J9 PHYS REV LETT JI Phys. Rev. Lett. PD SEP 2 PY 1991 VL 67 IS 10 BP 1282 EP 1285 DI 10.1103/PhysRevLett.67.1282 PG 4 WC Physics, Multidisciplinary SC Physics GA GC957 UT WOS:A1991GC95700027 ER PT J AU ZHANG, XG VANHOVE, MA SOMORJAI, GA ROUS, PJ TOBIN, D GONIS, A MACLAREN, JM HEINZ, K MICHL, M LINDNER, H MULLER, K EHSASI, M BLOCK, JH AF ZHANG, XG VANHOVE, MA SOMORJAI, GA ROUS, PJ TOBIN, D GONIS, A MACLAREN, JM HEINZ, K MICHL, M LINDNER, H MULLER, K EHSASI, M BLOCK, JH TI EFFICIENT DETERMINATION OF MULTILAYER RELAXATION IN THE PT(210) STEPPED AND DENSELY KINKED SURFACE SO PHYSICAL REVIEW LETTERS LA English DT Article ID ENERGY-ELECTRON-DIFFRACTION; TENSOR LEED; METALS; ATOMS AB The multilayer relaxation of the Pt(210) stepped and kinked surface is analyzed by low-energy-electron diffraction. This is the first application of the new real-space multiple-scattering theory of LEED, designed specifically for such open surfaces where conventional theories fail. Combined with an automated tensor LEED method, it efficiently detects nonalternating atomic relaxations which are oriented primarily perpendicular to the surface. These relaxations are in qualitative agreement with new embedded-atom-method results. C1 UNIV MARYLAND,DEPT PHYS,CATONSVILLE,MD 21228. UNIV CALIF LAWRENCE LIVERMORE NATL LAB,DIV MAT SCI,LIVERMORE,CA 94550. TULANE UNIV,DEPT PHYS,NEW ORLEANS,LA 70118. UNIV ERLANGEN NURNBERG,LEHRSTUHL FESTKORPERPHYS,W-8520 ERLANGEN,GERMANY. MAX PLANCK GESELL,FRITZ HABER INST,W-1000 BERLIN 33,GERMANY. RP ZHANG, XG (reprint author), UNIV CALIF BERKELEY LAWRENCE BERKELEY LAB,DIV MAT SCI,CTR ADV MAT,BERKELEY,CA 94720, USA. RI Van Hove, Michel/A-9862-2008 OI Van Hove, Michel/0000-0002-8898-6921 NR 25 TC 47 Z9 49 U1 1 U2 4 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 0031-9007 J9 PHYS REV LETT JI Phys. Rev. Lett. PD SEP 2 PY 1991 VL 67 IS 10 BP 1298 EP 1301 DI 10.1103/PhysRevLett.67.1298 PG 4 WC Physics, Multidisciplinary SC Physics GA GC957 UT WOS:A1991GC95700031 ER PT J AU FERRARI, MJ WELLSTOOD, FC KINGSTON, JJ CLARKE, J AF FERRARI, MJ WELLSTOOD, FC KINGSTON, JJ CLARKE, J TI SUPPRESSION OF MAGNETIC-FLUX NOISE IN YBA2CU3O7-X BY A SUPERCURRENT SO PHYSICAL REVIEW LETTERS LA English DT Article ID HIGH-TEMPERATURE SUPERCONDUCTORS; VORTEX-GLASS SUPERCONDUCTIVITY; BA-CU-O; ACTIVATION-ENERGIES; THIN-FILMS; CREEP; DISSIPATION AB The magnetic-flux noise generated by a patterned film of YBa2Cu3O7-x is reversibly suppressed by the application of a supercurrent. The total noise power decreases by an order of magnitude, in quantitative agreement with a model involving thermally activated vortex hopping between pairs of pinning sites of nearly equal pinning energy. The model yields a force constant of 6 x 10(-5) N/m for a vortex at a typical pinning site, and a hopping distance which increases with temperature from 13 nm at 4.2 K to 64 nm at 60 K. The number density of vortices is at least 0.02-mu-m-2, even in a magnetic field of less than 1-mu-T. C1 UNIV CALIF BERKELEY LAWRENCE BERKELEY LAB,DIV MAT SCI,CTR ADV MAT,BERKELEY,CA 94720. RP FERRARI, MJ (reprint author), UNIV CALIF BERKELEY,DEPT PHYS,BERKELEY,CA 94720, USA. RI Joint Quantum Institute, NIST/UMD/H-4494-2011 NR 21 TC 25 Z9 25 U1 0 U2 2 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 0031-9007 J9 PHYS REV LETT JI Phys. Rev. Lett. PD SEP 2 PY 1991 VL 67 IS 10 BP 1346 EP 1349 DI 10.1103/PhysRevLett.67.1346 PG 4 WC Physics, Multidisciplinary SC Physics GA GC957 UT WOS:A1991GC95700043 ER PT J AU CHAN, LP HARSHMAN, DR LYNN, KG MASSIDDA, S MITZI, DB AF CHAN, LP HARSHMAN, DR LYNN, KG MASSIDDA, S MITZI, DB TI PAIR MOMENTUM DISTRIBUTION IN BI2SR2CACU2O8+DELTA MEASURED BY POSITRON-ANNIHILATION - EXISTENCE AND NATURE OF THE FERMI-SURFACE SO PHYSICAL REVIEW LETTERS LA English DT Article ID HIGH-TC SUPERCONDUCTORS; ANGLE-RESOLVED-PHOTOEMISSION; ANDERSON LATTICE MODEL; CA-CU-O; ELECTRONIC-STRUCTURE; SINGLE-CRYSTALS; NORMAL-STATE; PLANE AB We report the first measurement of the positron-electron momentum density in superconducting single-crystal Bi2Sr2CaCu2O8 + delta (T(c) almost-equal-to 90 K). The observed anisotropy exhibits a twofold (rather than fourfold) symmetry, which is attributed to the superlattice modulation along the b axis of the BiO2 layers. Subtraction of the superlattice contribution also reveals a pair momentum distribution consistent with the CuO2 and BiO2 Fermi surfaces, and in reasonable agreement with the theoretical pair momentum density derived from band theory. C1 AT&T BELL LABS,N ANDOVER,MA 01845. PHB ECUBLENS,INST ROMAND RECH NUMER PHYS MAT,CH-105 LAUSANNE,SWITZERLAND. STANFORD UNIV,DEPT PHYS,STANFORD,CA 94305. RP CHAN, LP (reprint author), BROOKHAVEN NATL LAB,UPTON,NY 11973, USA. RI Mitzi, David/B-6260-2012 OI Mitzi, David/0000-0001-5189-4612 NR 26 TC 32 Z9 32 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 SEP 2 PY 1991 VL 67 IS 10 BP 1350 EP 1353 DI 10.1103/PhysRevLett.67.1350 PG 4 WC Physics, Multidisciplinary SC Physics GA GC957 UT WOS:A1991GC95700044 ER PT J AU NORTON, DP LOWNDES, DH PENNYCOOK, SJ BUDAI, JD AF NORTON, DP LOWNDES, DH PENNYCOOK, SJ BUDAI, JD TI DEPRESSION AND BROADENING OF THE SUPERCONDUCTING TRANSITION IN SUPERLATTICES BASED ON YBA2CU3O7-DELTA - INFLUENCE OF THE BARRIER LAYERS SO PHYSICAL REVIEW LETTERS LA English DT Article ID YBA2CU3O7-X/PRBA2CU3O7-X SUPERLATTICES; THIN-FILMS AB The superconducting properties of YBa2Cu3O7-delta-based superlattices are shown to depend strongly on the electronic properties of the barrier layers. The resistive transition width decreases significantly as the hole carrier density in the barrier layers is increased. However, T(c) (onset) does not change, contrary to predictions of hole-filling models. T(c) (onset) is apparently determined by the YBa2Cu3O7-delta layer thickness, while the transition width, determined by long-range phase coherence of the superconducting wave function, depends on the electronic properties of the isolating barrier layers. RP NORTON, DP (reprint author), OAK RIDGE NATL LAB,DIV SOLID STATE,POB 2008,OAK RIDGE,TN 37831, USA. RI Budai, John/R-9276-2016 OI Budai, John/0000-0002-7444-1306 NR 30 TC 52 Z9 52 U1 0 U2 0 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 0031-9007 J9 PHYS REV LETT JI Phys. Rev. Lett. PD SEP 2 PY 1991 VL 67 IS 10 BP 1358 EP 1361 DI 10.1103/PhysRevLett.67.1358 PG 4 WC Physics, Multidisciplinary SC Physics GA GC957 UT WOS:A1991GC95700046 ER PT J AU CANNON, RM DALGLEISH, BJ DAUSKARDT, RH OH, TS RITCHIE, RO AF CANNON, RM DALGLEISH, BJ DAUSKARDT, RH OH, TS RITCHIE, RO TI CYCLIC FATIGUE-CRACK PROPAGATION ALONG CERAMIC METAL INTERFACES SO ACTA METALLURGICA ET MATERIALIA LA English DT Article ID MECHANICS; FRACTURE; ALUMINA AB The integrity of ceramic/metal joints is investigated under mechanically applied cyclic stresses using double-cantilever-beam, and compact-tension, sandwich test specimens. Specifically, fatigue-crack propagation rates for interfacial cracks are characterized over a range of velocities from 10(-9) to 10(-4) m/s for glass/copper and alumina/aluminum-alloy interfaces tested in moist air. Compared to corresponding (stress-corrosion) results under sustained loading, it is found that true interfacial cracks in glass-copper joints are significantly accelerated under cyclic loads. In addition, crack extension force (G) thresholds for interfacial crack growth under cyclic loads are some 46% lower than under sustained loads and are typically over six times lower than the interface toughness (G(c)). For the alumina/aluminum-alloy system, conversely, fracture never occurs in the interface; under monotonic loading cracking progresses near the interface in the ceramic layer whereas under cyclic loading failure may occur either in the ceramic or in the metal. Based on a comparison with fatigue-crack growth data in bulk alumina and bulk aluminum alloys, it is found that near interfacial crack-growth rates in the metal are much lower than those of the bulk ceramic and show a far higher dependency on the range of G than behavior in the bulk metal. C1 UNIV CALIF BERKELEY, DEPT MAT SCI & MINERAL ENGN, BERKELEY, CA 94720 USA. RP CANNON, RM (reprint author), UNIV CALIF BERKELEY LAWRENCE BERKELEY LAB, CTR ADV MAT, BERKELEY, CA 94720 USA. RI Ritchie, Robert/A-8066-2008 OI Ritchie, Robert/0000-0002-0501-6998 NR 30 TC 72 Z9 74 U1 1 U2 18 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLAND SN 0956-7151 J9 ACTA METALL MATER JI Acta Metall. Mater. PD SEP PY 1991 VL 39 IS 9 BP 2145 EP 2156 DI 10.1016/0956-7151(91)90184-3 PG 12 WC Materials Science, Multidisciplinary; Metallurgy & Metallurgical Engineering SC Materials Science; Metallurgy & Metallurgical Engineering GA GB406 UT WOS:A1991GB40600009 ER PT J AU BLACKER, TD STEPHENSON, MB CANANN, S AF BLACKER, TD STEPHENSON, MB CANANN, S TI ANALYSIS AUTOMATION WITH PAVING - A NEW QUADRILATERAL MESHING TECHNIQUE SO ADVANCES IN ENGINEERING SOFTWARE AND WORKSTATIONS LA English DT Article AB This paper describes the impact of paving, a new automatic mesh generation algorithm, on the analysis portion of the design process. Paving generates an all-quadrilateral mesh in arbitrary 2D geometries. The paving technique significantly impacts the analysis process by drastically reducing the time and expertise requirements of traditional mesh generation. Paving produces a high quality mesh based on geometric boundary definitions and user specified element sizing constraints. In this paper we describe the paving algorithm, discuss varying aspects of the impact of the technique on design automation, and elaborate on current research into 3D all-hexahedral mesh generation. C1 BRIGHAM YOUNG UNIV,PROVO,UT 84602. RP BLACKER, TD (reprint author), SANDIA NATL LABS,ALBUQUERQUE,NM 87185, USA. NR 11 TC 5 Z9 6 U1 0 U2 0 PU ELSEVIER SCI LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD, OXON, ENGLAND OX5 1GB SN 0961-3552 J9 ADV ENG SOFTW WORKST PD SEP-NOV PY 1991 VL 13 IS 5-6 BP 332 EP 337 DI 10.1016/0961-3552(91)90037-5 PG 6 WC Engineering, Multidisciplinary SC Engineering GA HW015 UT WOS:A1991HW01500012 ER PT J AU CLAPP, NK HENKE, MA HANSARD, RM WALSH, RE WIDOMSKI, DL ANGLIN, CP FRETLAND, DJ GAGINELLA, TS AF CLAPP, NK HENKE, MA HANSARD, RM WALSH, RE WIDOMSKI, DL ANGLIN, CP FRETLAND, DJ GAGINELLA, TS TI INFLAMMATORY MEDIATORS IN COTTON-TOP TAMARINS (CTT) WITH ACUTE AND CHRONIC COLITIS SO AGENTS AND ACTIONS LA English DT Article; Proceedings Paper CT 5TH INTERNATIONAL CONF OF THE INFLAMMATION RESEARCH ASSOC CY SEP 23-27, 1990 CL WHITE HAVEN, PA SP INFLAMMAT RES ASSOC ID BOWEL-DISEASE AB Spontaneous colitis in CTT's presents cytological characteristics similar to chronic ulcerative colitis in humans, e.g. inflammatory cell infiltrate and crypt abscesses. To better characterize CTT colitis as a potential model for human inflammatory bowel disease (IBD), inflammatory mediators identified in colonic tissue of human IBD patients and/or experimental colitis models were assayed. Inflammatory mediator changes in plasma and colon from tamarins with acute (n = 10) and chronic (n = 10) colitis (by mucosal biopsy) were assayed by RIAs. Similar inflammatory mediators were found in the CTT's with acute colitis. In the plasma, PAF and PGE2 levels were lower in acute colitis CTT's, no LTB4 was detected, and histamine levels were not different from chronic colitic animals. In the colon, myeloperoxidase and interleukin-1-beta were significantly higher in acute colitis, PGE2 and LTB4 were higher but not significantly, and PAF was not different from chronic CTT's. These data suggest that a combination of events are occurring in the pathogenesis of tamarin colitis that involves some of the same mediators that are found in the human disease and in other experimental models. The importance of these findings to human IBD remains for further investigation; however, the spontaneous primate model offers an exciting approximation of the disease development and merits further investigation for understanding the pathogenesis of human IBD as well as to aid in development of targeted therapeutics. C1 SEARLE RES & DEV,GASTROINTESTINAL DIS RES,SKOKIE,IL 60077. RP CLAPP, NK (reprint author), OAK RIDGE ASSOCIATED UNIV,MARMOSET RES CTR,OAK RIDGE,TN 37831, USA. NR 8 TC 6 Z9 6 U1 0 U2 0 PU BIRKHAUSER VERLAG AG PI BASEL PA PO BOX 133 KLOSTERBERG 23, CH-4010 BASEL, SWITZERLAND SN 0065-4299 J9 AGENTS ACTIONS JI Agents Actions PD SEP PY 1991 VL 34 IS 1-2 BP 178 EP 180 DI 10.1007/BF01993271 PG 3 WC Chemistry, Multidisciplinary; Pharmacology & Pharmacy SC Chemistry; Pharmacology & Pharmacy GA GJ048 UT WOS:A1991GJ04800051 PM 1665291 ER PT J AU KENNEDY, IM KOLLMANN, W CHEN, JY AF KENNEDY, IM KOLLMANN, W CHEN, JY TI PREDICTIONS OF SOOT IN LAMINAR DIFFUSION FLAMES SO AIAA JOURNAL LA English DT Article; Proceedings Paper CT 28TH MEETING ON AEROSPACE SCIENCES CY JAN 08-11, 1990 CL RENO, NV SP AMER INST AERONAUT & ASTRONAUT ID PARTICLES AB A model for soot formation in diffusion flames is proposed in which a correlation between mixture fraction and soot surface growth rate is used. The correlation is derived from measurements in a stagnation point diffusion flame. The calculation solves the boundary-layer form of the flow equations, which include the continuity equation, momentum, mixture fraction, and the enthalpy equations. The latter equation is included to account for radiation, which earlier studies found to be important in determining the flame temperatures in sooty flames and the rates of soot reactions. Results are presented for two laminar flows. The first is an axisymmetric laminar jet diffusion flame and the second is a Wolfhard-Parker two-dimensional flame. Good agreement has been obtained for both flows without adjustment of the model parameters. C1 SANDIA NATL LABS,COMRUST RES FACIL,LIVERMORE,CA 94551. RP KENNEDY, IM (reprint author), UNIV CALIF DAVIS,DEPT MECH ENGN,DAVIS,CA 95616, USA. NR 26 TC 15 Z9 15 U1 0 U2 3 PU AMER INST AERONAUT ASTRONAUT PI RESTON PA 1801 ALEXANDER BELL DRIVE, STE 500, RESTON, VA 22091 SN 0001-1452 J9 AIAA J JI AIAA J. PD SEP PY 1991 VL 29 IS 9 BP 1452 EP 1457 DI 10.2514/3.10759 PG 6 WC Engineering, Aerospace SC Engineering GA GD700 UT WOS:A1991GD70000015 ER PT J AU ANDERKO, A PITZER, KS AF ANDERKO, A PITZER, KS TI EQUATION OF STATE FOR PURE FLUIDS AND MIXTURES BASED ON A TRUNCATED VIRIAL EXPANSION SO AICHE JOURNAL LA English DT Article ID VAPOR LIQUID EQUILIBRIA; + NORMAL-HEXADECANE; CARBON-DIOXIDE; THERMODYNAMIC PROPERTIES; PHASE-EQUILIBRIA; NITROGEN; METHANE; PRESSURES; RANGE; TETRAFLUOROMETHANE AB An accurate, yet simple, equation of state was developed for pure fluids ranging from nonpolar to H2O and their mixtures. The equation consists of a virial expansion truncated after the fourth virial coefficient and a closed-form term approximating higher coefficients. For nonpolar or weakly polar compounds, the equation is generalized using critical temperature, critical pressure, and acentric factor. Despite its simplicity, the equation represents the P-V-T and saturation properties of pure fluids with a very good accuracy, which is comparable to that of multiparameter, generalized BWR-type equations. For mixture calculations, mixing rules were formulated based on the rigorously known composition dependence of virial coefficients. The equation represents vapor-liquid, gas-gas and liquid-liquid equilibria, as well as volumetric properties of mixtures containing nonpolar components and/or water. Binary parameters can be generalized for series of mixtures containing a common component. C1 UNIV CALIF BERKELEY LAWRENCE BERKELEY LAB,BERKELEY,CA 94720. RP ANDERKO, A (reprint author), UNIV CALIF BERKELEY,DEPT CHEM,BERKELEY,CA 94720, USA. OI Anderko, Andrzej/0000-0002-1522-4889 NR 85 TC 21 Z9 22 U1 1 U2 12 PU AMER INST CHEMICAL ENGINEERS PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 SN 0001-1541 J9 AICHE J JI AICHE J. PD SEP PY 1991 VL 37 IS 9 BP 1379 EP 1391 DI 10.1002/aic.690370910 PG 13 WC Engineering, Chemical SC Engineering GA GF563 UT WOS:A1991GF56300009 ER PT J AU SUPERKO, HR BORTZ, W WILLIAMS, PT ALBERS, JJ WOOD, PD AF SUPERKO, HR BORTZ, W WILLIAMS, PT ALBERS, JJ WOOD, PD TI CAFFEINATED AND DECAFFEINATED COFFEE EFFECTS ON PLASMA-LIPOPROTEIN CHOLESTEROL, APOLIPOPROTEINS, AND LIPASE ACTIVITY - A CONTROLLED, RANDOMIZED TRIAL SO AMERICAN JOURNAL OF CLINICAL NUTRITION LA English DT Article DE COFFEE; LIPOPROTEINS; CHOLESTEROL; LIPOPROTEIN LIPASE; APOLIPOPROTEIN-B ID CORONARY HEART-DISEASE; SERUM-CHOLESTEROL; CARDIOVASCULAR-DISEASE; BLOOD-PRESSURE; BOILED COFFEE; CONSUMPTION; MEN; DRINKING; LIPIDS; FRAMINGHAM AB Coffee consumption has been associated with elevated plasma cholesterol. One hundred eighty-one men consumed a standard caffeinated coffee for 2 mo followed by randomization to continue caffeinated coffee (control), change to decaffeinated coffee or no coffee for 2 mo. Plasma low-density-lipoprotein (LDL) cholesterol and apolipoprotein B concentrations increased significantly (0.12 +/- 0.65 mmol/L, P < 0.025; 0.06 +/- 0.12 g/L, P < 0.0004, respectively) in the group that changed to decaffeinated coffee. In a subgroup (n = 51), postheparin lipoprotein lipase decreased significantly more (-270 mmol free fatty acids . L-1.h-1, P < 0.003) in the decaffeinated-coffee group. Resting heart rate and blood pressure did not change significantly. Change from caffeinated to decaffeinated coffee increased plasma LDL cholesterol and apolipoprotein B whereas discontinuation of caffeinated coffee revealed no change. This finding suggests that a coffee component other than caffeine is responsible for the LDL cholesterol, apolipoprotein B, and lipase activity changes reported in this investigation. C1 STANFORD UNIV,MED CTR,SCH MED,STANFORD CTR RES DIS PREVENT,STANFORD,CA 94305. UNIV CALIF BERKELEY LAWRENCE BERKELEY LAB,BERKELEY,CA 94720. UNIV WASHINGTON,SCH MED,DEPT MED,SEATTLE,WA 98195. UNIV WASHINGTON,SCH MED,DEPT PATHOL,SEATTLE,WA 98195. OI Superko, H. Robert/0000-0002-3542-0393 FU NHLBI NIH HHS [HL 24462, HL 30086] NR 65 TC 38 Z9 39 U1 1 U2 4 PU AMER SOC CLIN NUTRITION INC PI BETHESDA PA 9650 ROCKVILLE PIKE SUBSCRIPTIONS, RM L-2310, BETHESDA, MD 20814-3998 SN 0002-9165 J9 AM J CLIN NUTR JI Am. J. Clin. Nutr. PD SEP PY 1991 VL 54 IS 3 BP 599 EP 605 PG 7 WC Nutrition & Dietetics SC Nutrition & Dietetics GA GD041 UT WOS:A1991GD04100027 PM 1877516 ER PT J AU PETERSON, RC LAGER, GA HITTERMAN, RL AF PETERSON, RC LAGER, GA HITTERMAN, RL TI A TIME-OF-FLIGHT NEUTRON POWDER DIFFRACTION STUDY OF MGAL2O4 AT TEMPERATURES UP TO 1273-K SO AMERICAN MINERALOGIST LA English DT Article ID CATION-DISTRIBUTION; SPINEL; DISORDER; TRANSITION AB Time-of-flight neutron powder diffraction data have been obtained in situ at temperatures up to 1273 K for two samples of MgAl2O4 (spinel). The samples were synthesized under different experimental conditions (single-crystal boule vs. air-quenched sintered pellet) and exhibited different degrees of cation disorder at room temperature. The Riet-veld method was used to fit the data, which were obtained initially at room temperature and then at various temperatures as the samples were cooled from 1273 K. Both samples exhibit statistically equivalent degrees of disorder in the temperature range 973-1273 K. The atomic fraction of Al in the tetrahedral site increases from 0.25(1) at 973 K to 0.35(2) at 1273 K. This amount of disorder is significantly less than that determined by an earlier nuclear magnetic resonance experiment. The slight nonuniform variation of the atomic parameters in this temperature range for both samples may suggest a behavior that is inconsistent with a simple process of cation reordering on cooling. C1 UNIV LOUISVILLE,DEPT GEOL,LOUISVILLE,KY 40292. ARGONNE NATL LAB,DIV IPNS,ARGONNE,IL 60439. RP PETERSON, RC (reprint author), QUEENS UNIV,DEPT GEOL SCI,KINGSTON K7L 3N6,ONTARIO,CANADA. NR 15 TC 110 Z9 110 U1 0 U2 13 PU MINERALOGICAL SOC AMER PI WASHINGTON PA 1130 17TH ST NW SUITE 330, WASHINGTON, DC 20036 SN 0003-004X J9 AM MINERAL JI Am. Miner. PD SEP-OCT PY 1991 VL 76 IS 9-10 BP 1455 EP 1458 PG 4 WC Geochemistry & Geophysics; Mineralogy SC Geochemistry & Geophysics; Mineralogy GA GL397 UT WOS:A1991GL39700002 ER PT J AU MURAKAMI, T CHAKOUMAKOS, BC EWING, RC LUMPKIN, GR WEBER, WJ AF MURAKAMI, T CHAKOUMAKOS, BC EWING, RC LUMPKIN, GR WEBER, WJ TI ALPHA-DECAY EVENT DAMAGE IN ZIRCON SO AMERICAN MINERALOGIST LA English DT Article ID RADIATION-DAMAGE; SRI-LANKA; LATTICE-DEFECTS; METAMICT STATE; LEAD RETENTION; NATURAL ZIRCON; MINERALS; AMORPHIZATION; CRYSTALLINE; DISSOLUTION AB Based on density measurements, X-ray diffraction analysis, and high-resolution transmission electron microscopy of a suite of natural zircon samples from Sri Lanka (0.06 x 10(15) to 6.8 x 10(15) alpha-decay events/mg), three stages of damage accumulation may be delineated. Stage I (< 3 x 10(15) alpha-decay events/mg) is characterized by sharp Bragg diffraction maxima with a minor contribution from the diffuse-scattering component. Electron diffraction patterns were sharp. Damage is dominated by the accumulation of isolated point defects, which cause unit-cell expansion and distortion that account for most of the decrease in density. These defects may partially anneal over geologic periods of time. Stage II (3 x 10(15) to 8 x 10(15) alpha-decay events/mg) is characterized by significant decreases in the intensity of the Bragg diffraction maxima, which become asymmetric from increased contributions of the diffuse-scattering component. High-resolution transmission electron microscopy indicated that the microstructure consists of distorted crystalline regions and amorphous "tracks" caused by alpha-recoil nuclei. With increasing alpha-decay dose, damaged crystalline regions are converted into aperiodic regions but with no further significant expansion of the unit cell in the remaining crystalline regions. Stage III (> 8 x 10(15) alpha-decay events/mg) consists of material that is entirely aperiodic as far as can be determined by X-ray or electron diffraction. There was no evidence for the formation of ZrO2 or SiO2 as final products during the last stage of metamictization. Based on modeled density changes, aperiodic regions continue to experience a change in structure as they are redamaged. During stage II of the process, the modeled density of aperiodic regions changes from 4.5 g/cm3 to 4.1 g/cm3. Fission fragment damage does not contribute to the process of metamictization. The amorphization process is consistent with a model for the multiple overlap of displacement cascades, suggesting amorphization occurs as a result of defect accumulation rather than directly within a single displacement cascade. Comparison of results for natural zircon with those for Pu-doped zircon showed that dose-rate variations (even as great as a factor of 10(8)) had no substantial effect on the damage accumulation process. Unit-cell parameters increased and density decreased more for the Pu-doped zircon than for natural zircon in the early stages of damage accumulation (< 3 x 10(15) alpha-decay events/mg), suggesting that annealing of point defects in the early stages of the damage accumulation process occurs in natural zircon under ambient conditions. This accounts for the distinct sigmoidal shape of the damage curves for natural zircon and the apparent incubation period before the onset of amorphization. C1 OAK RIDGE NATL LAB, DIV SOLID STATE, OAK RIDGE, TN 37831 USA. UNIV NEW MEXICO, DEPT GEOL, ALBUQUERQUE, NM 87131 USA. AUSTRALIAN NUCL SCI & TECHNOL ORG, ADV MATERIALS PROGRAM, MENAI, NSW 2234, AUSTRALIA. PACIFIC NW LAB, RICHLAND, WA 99352 USA. RP MURAKAMI, T (reprint author), JAPAN ATOM ENERGY RES INST, DEPT ENVIRONM SAFETY RES, TOKAI, IBARAKI 31911, JAPAN. RI Lumpkin, Gregory/A-7558-2008; Weber, William/A-4177-2008; Chakoumakos, Bryan/A-5601-2016 OI Weber, William/0000-0002-9017-7365; Chakoumakos, Bryan/0000-0002-7870-6543 NR 85 TC 254 Z9 262 U1 4 U2 39 PU MINERALOGICAL SOC AMER PI WASHINGTON PA 1130 17TH ST NW SUITE 330, WASHINGTON, DC 20036 SN 0003-004X J9 AM MINERAL JI Am. Miner. PD SEP-OCT PY 1991 VL 76 IS 9-10 BP 1510 EP 1532 PG 23 WC Geochemistry & Geophysics; Mineralogy SC Geochemistry & Geophysics; Mineralogy GA GL397 UT WOS:A1991GL39700008 ER PT J AU DEINHAMMER, RS SHIMAZU, K PORTER, MD AF DEINHAMMER, RS SHIMAZU, K PORTER, MD TI ION CHROMATOGRAPHIC SEPARATIONS USING STEP AND LINEAR VOLTAGE WAVE-FORMS AT A CHARGE-CONTROLLABLE POLYMERIC STATIONARY PHASE SO ANALYTICAL CHEMISTRY LA English DT Letter ID POLYPYRROLE; FILMS; ELECTROCHEMISTRY; POLYANILINE; ELECTRODE; PYRROLES; COLUMN C1 IOWA STATE UNIV SCI & TECHNOL,DEPT CHEM,AMES,IA 50011. IOWA STATE UNIV SCI & TECHNOL,US DOE,AMES LAB,AMES,IA 50011. NR 31 TC 44 Z9 44 U1 0 U2 0 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 SN 0003-2700 J9 ANAL CHEM JI Anal. Chem. PD SEP 1 PY 1991 VL 63 IS 17 BP 1889 EP 1894 DI 10.1021/ac00017a040 PG 6 WC Chemistry, Analytical SC Chemistry GA GC931 UT WOS:A1991GC93100041 ER PT J AU WU, JS BOTTCHER, C STRAYER, MR KERMAN, AK AF WU, JS BOTTCHER, C STRAYER, MR KERMAN, AK TI COHERENT HIGGS AND W+/- PAIR PRODUCTION SO ANNALS OF PHYSICS LA English DT Article ID HEAVY-ION COLLISIONS; STRONGLY INTERACTING WS; BOSON PRODUCTION; COLLIDERS; PHYSICS; ZS C1 UNIV TENNESSEE,DEPT PHYS,KNOXVILLE,TN 37996. RP WU, JS (reprint author), OAK RIDGE NATL LAB,DIV PHYS,CTR COMPUTAT INTENS PHYS,OAK RIDGE,TN 37831, USA. NR 34 TC 13 Z9 13 U1 0 U2 1 PU ACADEMIC PRESS INC JNL-COMP SUBSCRIPTIONS PI SAN DIEGO PA 525 B ST, STE 1900, SAN DIEGO, CA 92101-4495 SN 0003-4916 J9 ANN PHYS-NEW YORK JI Ann. Phys. PD SEP PY 1991 VL 210 IS 2 BP 402 EP 437 DI 10.1016/0003-4916(91)90049-E PG 36 WC Physics, Multidisciplinary SC Physics GA GC817 UT WOS:A1991GC81700006 ER PT J AU WILLIAMS, AG KREIN, G ROBERTS, CD AF WILLIAMS, AG KREIN, G ROBERTS, CD TI MODELING THE QUARK PROPAGATOR SO ANNALS OF PHYSICS LA English DT Article ID CHIRAL-SYMMETRY-BREAKING; PARTICLE MASS GENERATION; GAUGE FIELD-THEORIES; QUANTUM CHROMODYNAMICS; AXIAL GAUGE; ANALYTIC PROPERTIES; ASYMPTOTIC FREEDOM; GLUON PROPAGATOR; VERTEX FUNCTION; QCD C1 ARGONNE NATL LAB,THEORY GRP,ARGONNE,IL 60439. RP WILLIAMS, AG (reprint author), FLORIDA STATE UNIV,RES INST,DEPT PHYS & SUPERCOMP COMPUTAT,TALLAHASSEE,FL 32306, USA. RI Williams, Anthony/I-6698-2012; Krein, Gastao/C-1204-2012; OI Krein, Gastao/0000-0003-1713-8578; Roberts, Craig/0000-0002-2937-1361; Williams, Anthony/0000-0002-1472-1592 NR 62 TC 47 Z9 47 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 SEP PY 1991 VL 210 IS 2 BP 464 EP 485 DI 10.1016/0003-4916(91)90051-9 PG 22 WC Physics, Multidisciplinary SC Physics GA GC817 UT WOS:A1991GC81700008 ER PT J AU ZAMZOW, D MURRAY, GM DSILVA, AP EDELSON, MC AF ZAMZOW, D MURRAY, GM DSILVA, AP EDELSON, MC TI HIGH-RESOLUTION OPTICAL-EMISSION SPECTROSCOPY OF URANIUM HEXAFLUORIDE IN THE ARGON AFTERGLOW DISCHARGE SO APPLIED SPECTROSCOPY LA English DT Article DE ANALYSIS FOR URANIUM; EMISSION SPECTROSCOPY; INSTRUMENTATION, EMISSION SPECTROSCOPY; ANALYTICAL METHODS; ISOTOPIC ANALYSIS; SPECTROSCOPIC TECHNIQUES ID INDUCTIVELY COUPLED PLASMA AB Uranium atom and ion emission spectra resulting from the introduction of gaseous uranium hexafluoride (UF6) into an atmospheric-pressure argon afterglow discharge source have been acquired with the use of a high-resolution spectrometer. The isotopic splitting (U-235/U-238) of the uranium ion line at 424.437 nm has been utilized to analyze three different UF6 samples containing 0.245%, 3.80%, and 51.20% U-235, respectively. A limit of detection for UF6 in argon of approximately 15 ppm for the U(II) 424.167-nm line has been achieved. C1 US DOE,AMES LAB,AMES,IA 50011. RI Murray, George/A-6625-2011 NR 11 TC 1 Z9 1 U1 1 U2 5 PU SOC APPLIED SPECTROSCOPY PI FREDERICK PA PO BOX 1438, FREDERICK, MD 21701 SN 0003-7028 J9 APPL SPECTROSC JI Appl. Spectrosc. PD SEP-OCT PY 1991 VL 45 IS 8 BP 1318 EP 1321 DI 10.1366/0003702914335788 PG 4 WC Instruments & Instrumentation; Spectroscopy SC Instruments & Instrumentation; Spectroscopy GA GL412 UT WOS:A1991GL41200016 ER PT J AU BOROVSKY, JE SUSZCYNSKY, DM BUCHWALD, MI DEHAVEN, HV AF BOROVSKY, JE SUSZCYNSKY, DM BUCHWALD, MI DEHAVEN, HV TI MEASURING THE THICKNESSES OF AURORAL CURTAINS SO ARCTIC LA English DT Article DE AURORA; GEOMAGNETISM; IONOSPHERE; NORTHWEST TERRITORIES; PHOTOGRAPHY; POLAR ID FIELD-ALIGNED CURRENTS; KILOMETRIC RADIATION; ARCS; ACCELERATION; ULTRAVIOLET; ELECTRONS; WAVES; MODEL AB Auroral arcs (curtains) are extremely thin. A calculation of the minimum-possible are thickness is presented; this minimum thickness is found to be about 9.5 m. Four requirements for designing an optical system that can image the thinnest curtains are discussed: 1) angular resolution, 2) temporal resolution, 3) light-gathering power, and 4) data-recording convenience. An optical system meeting these four requirements was constructed. With this system, an observing campaign in Fort Smith, Northwest Territories, has begun and images of the small-scale structure of auroral arcs are presented. Are thicknesses of approximately 40 m were observed. These measurements of are thicknesses may provide a critical test for the many theories about the origins of auroral arcs. C1 UNIV CALIF LOS ALAMOS SCI LAB,ATMOSPHER SCI GRP,LOS ALAMOS,NM 87545. RP BOROVSKY, JE (reprint author), UNIV CALIF LOS ALAMOS SCI LAB,SPACE PLASMA PHYS GRP,LOS ALAMOS,NM 87545, USA. NR 58 TC 36 Z9 37 U1 0 U2 2 PU ARCTIC INST N AMER PI CALGARY PA UNIV OF CALGARY 2500 UNIVERSITY DRIVE NW 11TH FLOOR LIBRARY TOWER, CALGARY AB T2N 1N4, CANADA SN 0004-0843 J9 ARCTIC JI Arctic PD SEP PY 1991 VL 44 IS 3 BP 231 EP 238 PG 8 WC Environmental Sciences; Geography, Physical SC Environmental Sciences & Ecology; Physical Geography GA GL032 UT WOS:A1991GL03200008 ER PT J AU GAO, YT STECKER, FW CLINE, DB AF GAO, YT STECKER, FW CLINE, DB TI THE LIGHTEST SUPERSYMMETRIC PARTICLE AND THE EXTRAGALACTIC GAMMA-RAY BACKGROUND SO ASTRONOMY & ASTROPHYSICS LA English DT Article DE COSMOLOGY; DARK MATTER; ELEMENTARY PARTICLES; GAMMA-RAYS, GENERAL; RADIATION MECHANISMS, GENERAL ID DARK MATTER ANNIHILATION; COSMOLOGY; UNIVERSE AB Studies of cosmic dark matter (DM) and gamma-rays are in the forefront of particle astrophysics. On the eve of the launch of the Gamma Ray Observatory (GRO), effort has been devoted to investigate the low-energy diffuse cosmic gamma-ray spectrum due to the cosmological photino annihilation. Using a corrected assumption for annihilation cross section, we now generalize this work to the annihilation of a general type of the best-motivated cold dark matter (CDM) candidates, the lightest supersymmetric particle (LSP), with our cosmological integrations back into the history of the Universe. Our conclusion is that the cosmological LSP-type annihilation can not be a major contributor to the observed extragalactic gamma-ray background (EGB). C1 UNIV CALIF LOS ANGELES, DEPT PHYS, LOS ANGELES, CA 90024 USA. NASA, GODDARD SPACE FLIGHT CTR, HIGH ENERGY ASTROPHYS LAB, GREENBELT, MD 20771 USA. FERMI NATL ACCELERATOR LAB, BATAVIA, IL 60510 USA. RP GAO, YT (reprint author), UNIV CALIF LOS ANGELES, DEPT ASTRON, LOS ANGELES, CA 90024 USA. RI Stecker, Floyd/D-3169-2012 NR 23 TC 13 Z9 13 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 SEP PY 1991 VL 249 IS 1 BP 1 EP 4 PG 4 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA GF566 UT WOS:A1991GF56600002 ER PT J AU GRATSON, MW GRATSON, GK BERGERUD, AT AF GRATSON, MW GRATSON, GK BERGERUD, AT TI MALE-DOMINANCE AND COPULATION DISRUPTION DO NOT EXPLAIN VARIANCE IN MALE MATING SUCCESS ON SHARP-TAILED GROUSE (TYMPANUCHUS-PHASIANELLUS) LEKS SO BEHAVIOUR LA English DT Article ID SNIPE GALLINAGO-MEDIA; OF-THE-ROCK; SEXUAL SELECTION; COURTSHIP DISRUPTION; BREEDING BIRD; FALLOW DEER; MATE CHOICE; SAGE GROUSE; ORGANIZATION; EVOLUTION AB This study tested two hypotheses: that male-male competition and dominance relationships among males, rather than female choice of mates, principally determined the extreme variance in male mating success at sharp-tailed grouse leks; and, that male-male competition and dominance relationships among males principally determined the structure of the lek mating system as suggested by the recent "hotshot" model of lek organization (BEEHLER & FOSTER, 1988). Not all males in the study population obtained lek territories and more of those males that did were adults and had longer tarsometatarses than non-lekking males, which only visited leks and displayed elsewhere. There were no differences between lekking and non-lekking males in mean body mass, wing length, and supraorbital comb size however. Dominant males, where dominance was measured by differences in the frequency that males were disrupted during courtship of females by neighbours, were not the most successful at obtaining copulations at leks. This is the strongest evidence that we have against the complete applicability of the hotshot model to our population of sharp-tailed grouse. Dominance status could not be predicted on the basis of body size, comb size, or age class. Dominant males were not the owners of the most central-located territories, nor were the territories of the most successful males at obtaining copulations taken over by more dominant males after successful males were removed from their territories. These results too provide evidence against the applicability of the hotshot model to our population of sharp-tailed grouse. Copulation disruptions by neighbouring males were common at leks. Copulations were more likely to be unsuccessful when they were disrupted than otherwise and remating by individual females occurred more often after they were disrupted than otherwise. However, based on limited sample sizes, females were apparently no more likely to remate with the disrupting male than with any other and copulation disruptions only redistributed copulations among an already successful number of males. Only 26% of the variance in male mating success could be explained in a multiple regression by any two- or three-variable combination of male traits and this was explained by variance in male size and number of yellow leg-bands. Male mating success and male size were inversely correlated in individual tests of significance; on average, smaller males apparently obtained more matings. The more centrally-located males apparently obtained more matings, but territory location was not correlated with any other variable except (perhaps) survival. There was a tendency for surviving males to change from more exterior to more interior locations in successive years, apparently as a result of new males settling around them rather than as a result of direct competition for interior spots. Male removal experiments were performed in which the most successful males were removed on each of number of leks. Contrary to predictions of the hotshot model (BEEHLER & FOSTER, 1988), male recruitment to these leks and the numbers of females visiting and mating at these leks the following year did not decline, and there was no increase in the frequency of disrupted copulations in the year following male removal. Consistent with the hotshot model, however, the variance in male success apparently declined at two of three leks in the year following male removal. C1 UNIV VICTORIA,DEPT BIOL,VICTORIA V8W 2Y2,BC,CANADA. RP GRATSON, MW (reprint author), EG&G IDAHO INC,BOX 1625,IDAHO FALLS,ID 83415, USA. NR 48 TC 33 Z9 33 U1 1 U2 5 PU E J BRILL PI LEIDEN PA PO BOX 9000, 2300 PA LEIDEN, NETHERLANDS SN 0005-7959 J9 BEHAVIOUR JI Behaviour PD SEP PY 1991 VL 118 BP 187 EP 213 DI 10.1163/156853991X00283 PN 3-4 PG 27 WC Behavioral Sciences; Zoology SC Behavioral Sciences; Zoology GA GT428 UT WOS:A1991GT42800003 ER PT J AU KENDE, H AF KENDE, H TI ETHYLENE BIOSYNTHESIS AND ACTION - RECENT PROGRESS SO BIOLOGICAL CHEMISTRY HOPPE-SEYLER LA English DT Meeting Abstract C1 MICHIGAN STATE UNIV,MICHICAN STAT UNIV US DOE,PLANT RES LAB,E LANSING,MI 48824. NR 0 TC 0 Z9 0 U1 0 U2 0 PU WALTER DE GRUYTER & CO PI BERLIN PA GENTHINER STRASSE 13, D-10785 BERLIN, GERMANY SN 0177-3593 J9 BIOL CHEM H-S JI Biol. Chem. Hoppe-Seyler PD SEP PY 1991 VL 372 IS 9 BP 689 EP 689 PG 1 WC Biochemistry & Molecular Biology SC Biochemistry & Molecular Biology GA GH537 UT WOS:A1991GH53700179 ER PT J AU LEDERER, H MAY, R DERSCH, D CRESPI, H BAER, G HILLEN, W HEUMANN, H AF LEDERER, H MAY, R DERSCH, D CRESPI, H BAER, G HILLEN, W HEUMANN, H TI TRANSLOCATION OF THE DNA-DEPENDENT RNA-POLYMERASE OF ESCHERICHIA-COLI SO BIOLOGICAL CHEMISTRY HOPPE-SEYLER LA English DT Meeting Abstract C1 ARGONNE NATL LAB,ARGONNE,IL 60439. MAX PLANCK INST BIOCHEM,W-8033 MARTINSRIED,GERMANY. INST MAX VON LAUE PAUL LANGEVIN,F-38042 GRENOBLE,FRANCE. UNIV ERLANGEN NURNBERG,INST MIKROBIOL & BIOCHEM,W-8520 ERLANGEN,GERMANY. NR 0 TC 0 Z9 0 U1 0 U2 0 PU WALTER DE GRUYTER & CO PI BERLIN PA GENTHINER STRASSE 13, D-10785 BERLIN, GERMANY SN 0177-3593 J9 BIOL CHEM H-S JI Biol. Chem. Hoppe-Seyler PD SEP PY 1991 VL 372 IS 9 BP 704 EP 705 PG 2 WC Biochemistry & Molecular Biology SC Biochemistry & Molecular Biology GA GH537 UT WOS:A1991GH53700219 ER PT J AU MENDELL, NR THODE, HC FINCH, SJ AF MENDELL, NR THODE, HC FINCH, SJ TI THE LIKELIHOOD RATIO TEST FOR THE 2-COMPONENT NORMAL MIXTURE PROBLEM - POWER AND SAMPLE-SIZE ANALYSIS SO BIOMETRICS LA English DT Note DE NONCENTRAL CHI-SQUARE DISTRIBUTION AB We find, through simulation and modeling, an approximation to the alternative distribution of the likelihood ratio test for two-component mixtures in which the components have different means but equal variances. We consider the range of mixing proportions from .05 through .95. Our simulation results indicate a dependence of power on the mixing proportion when pi < .2 and pi > .80. Our model results indicated that the alternative distribution is approximately noncentral chi-square, possibly with 2 degrees of freedom. Using this model, we estimate a sample of 40 is needed to have 50% power to detect a difference between means equal to 3.0 for mixing proportions between .2 and .8. The sample size increases to 50 when the mixing proportion is .90 (or .1) and 82 when the mixing proportion is .95 (or .05). This paper contains a complete table of sample sizes needed for 50%, 80%, and 90% power. C1 SUNY STONY BROOK,DEPT PREVENT MED,STONY BROOK,NY 11794. BROOKHAVEN NATL LAB,INJURY PREVENT & ANAL GRP,UPTON,NY 11973. RP MENDELL, NR (reprint author), SUNY STONY BROOK,DEPT APPL MATH & STAT,STONY BROOK,NY 11794, USA. NR 8 TC 42 Z9 43 U1 0 U2 3 PU INTERNATIONAL BIOMETRIC SOC PI WASHINGTON PA 808 17TH ST NW SUITE 200, WASHINGTON, DC 20006-3910 SN 0006-341X J9 BIOMETRICS JI Biometrics PD SEP PY 1991 VL 47 IS 3 BP 1143 EP 1148 DI 10.2307/2532666 PG 6 WC Biology; Mathematical & Computational Biology; Statistics & Probability SC Life Sciences & Biomedicine - Other Topics; Mathematical & Computational Biology; Mathematics GA GG509 UT WOS:A1991GG50900027 PM 1835889 ER PT J AU WIENER, MC KING, GI WHITE, SH AF WIENER, MC KING, GI WHITE, SH TI STRUCTURE OF A FLUID DIOLEOYLPHOSPHATIDYLCHOLINE BILAYER DETERMINED BY JOINT REFINEMENT OF X-RAY AND NEUTRON-DIFFRACTION DATA .1. SCALING OF NEUTRON DATA AND THE DISTRIBUTIONS OF DOUBLE-BONDS AND WATER SO BIOPHYSICAL JOURNAL LA English DT Article ID PHOSPHATIDYLCHOLINE MODEL MEMBRANES; LIPID BILAYERS; EGG LECITHIN; CONFORMATION; PHOSPHATIDYLETHANOLAMINE; HEXANE; LOCATION; PACKING AB We described in two previous papers a method for the joint refinement of the structure of fluid bilayers using neutron and x-ray diffraction data (Wiener, M. C., and S. H. White. 1991a, b. Biophys. J. 59:162-173 and 174-185). An essential part of the method is the appropriate scaling of the diffraction data. Here we describe the scaling of the neutron data and the determination of the transbilayer distribution of double bonds in liquid-crystalline (L-alpha phase) phospholipid bilayers of 1,2-dioleoyl-sn-glycero-3-phosphocholine (DOPC). The distribution was determined by neutron diffraction of oriented multilayers (66% RH) of DOPC specifically deuterated at the 9- and 10-positions of both acyl chains. The double-bond distribution is described accurately by a pair of Gaussian functions each located at a position Z(CC) = 7.88 +/- 0.09 angstrom from the bilayer center with 1/e-halfwidths of A(CC) = 4.29 +/-0.16 angstrom. Previously, we determined the transbilayer distribution of bromine atoms in a specifically halogenated lipid, 1-oleoyl-2-9,10-dibromostearoyl-sn-glycero-3-phosphocholine (OBPC), and showed it to be an isomorphous replacement for DOPC (Wiener, M. C., and S. H. White. 1991c. Biochemistry. In press). A comparison of the double-bond and bromine profiles indicates that the positions of the centers of the deuterated double bond and the brominated methylene Gaussian distributions are equal within experimental error and that each label undergoes similar average thermal motions with respect to the bilayer normal. The observation that the average position of a label on both acyl chains (the deuterated double bonds) is similar to the average position of a label on the 2-chain alone (the brominated methylenes) indicates that the maximum separation along the bilayer normal between the double bonds of the acyl chains is 1 angstrom or less. The fully-resolved transbilayer water distribution, previously determined at lower resolution (Jacobs, R. E., and S. H. White. 1989. Biochemistry. 28:3421-3437), was obtained from the analysis of neutron diffraction data of DOPC hydrated with a D2O/H2O mixture. The water distribution is described accurately by a pair of Gaussian functions each located at a position Z(W) = 22.51 +/- 0.77 angstrom from the bilayer center with 1/e-halfwidths of A(W) = 4.63 +/- 0.48 angstrom. We present the relative absolute neutron and x-ray structure factors of DOPC at 66% RH that will be used to solve the complete structure of DOPC which will be presented in a later paper of this series. C1 UNIV CALIF IRVINE,DEPT PHYSIOL & BIOPHYS,IRVINE,CA 92717. BROOKHAVEN NATL LAB,UPTON,NY 11973. RI White, Stephen/B-1053-2009 OI White, Stephen/0000-0001-8540-7907 FU NIGMS NIH HHS [GM-37291] NR 31 TC 92 Z9 92 U1 3 U2 12 PU BIOPHYSICAL SOCIETY PI BETHESDA PA 9650 ROCKVILLE PIKE, BETHESDA, MD 20814-3998 SN 0006-3495 J9 BIOPHYS J JI Biophys. J. PD SEP PY 1991 VL 60 IS 3 BP 568 EP 576 PG 9 WC Biophysics SC Biophysics GA GD082 UT WOS:A1991GD08200004 PM 1932548 ER PT J AU HEBBEL, RP MOHANDAS, N AF HEBBEL, RP MOHANDAS, N TI REVERSIBLE DEFORMATION-DEPENDENT ERYTHROCYTE CATION LEAK - EXTREME SENSITIVITY CONFERRED BY MINIMAL PEROXIDATION SO BIOPHYSICAL JOURNAL LA English DT Article ID PERMEABILITY; STRESS AB To determine the threshold at which red blood cells (RBC) begin to manifest deformation-dependent leakiness to monovalent cations, we examined net passive potassium leak during elliptical deformation. Normal RBC did not begin to leak appreciable amounts of potassium until shear stress reached 204 dyn/cm2, at which point they had attained > 96% of their maximal deformation. In striking contrast, RBC that had undergone minimal, physiologically relevant degrees of peroxidative damage induced by t-butylhydroperoxide began to leak potassium at only 59 dyn/cm2 when they had reached only 63% of their maximal deformation. The cation leak identified in this manner is not prelytic, and it is fully reversible. Therefore, these data may be relevant to abnormal cation leaks that develop in sickle red cells that have membranes damaged by autoxidative stress and that manifest an exuberant but reversible leakiness to monovalent cation during sickling-induced deformation of the cell membrane. C1 UNIV MINNESOTA,SCH MED,DEPT MED,MINNEAPOLIS,MN 55455. UNIV CALIF BERKELEY LAWRENCE BERKELEY LAB,DIV CELL & MOLEC BIOL,BERKELEY,CA 94720. FU NHLBI NIH HHS [HL31579, HL37528] NR 13 TC 28 Z9 28 U1 0 U2 0 PU BIOPHYSICAL SOCIETY PI BETHESDA PA 9650 ROCKVILLE PIKE, BETHESDA, MD 20814-3998 SN 0006-3495 J9 BIOPHYS J JI Biophys. J. PD SEP PY 1991 VL 60 IS 3 BP 712 EP 715 PG 4 WC Biophysics SC Biophysics GA GD082 UT WOS:A1991GD08200018 PM 1932555 ER PT J AU WINSTANLEY, D AF WINSTANLEY, D TI RESPONSE TO SKEPTICS OF GLOBAL WARMING - COMMENT SO BULLETIN OF THE AMERICAN METEOROLOGICAL SOCIETY LA English DT Letter RP WINSTANLEY, D (reprint author), US DOE,OFF PROGRAM ANAL,DIV PROGRAM INTEGRAT ANAL,WASHINGTON,DC 20585, USA. NR 4 TC 0 Z9 0 U1 0 U2 0 PU AMER METEOROLOGICAL SOC PI BOSTON PA 45 BEACON ST, BOSTON, MA 02108-3693 SN 0003-0007 J9 B AM METEOROL SOC JI Bull. Amer. Meteorol. Soc. PD SEP PY 1991 VL 72 IS 9 BP 1393 EP 1395 PG 3 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA GK190 UT WOS:A1991GK19000014 ER PT J AU LEESMILLER, SP ANDERSON, CW AF LEESMILLER, SP ANDERSON, CW TI THE DNA-ACTIVATED PROTEIN-KINASE, DNA-PK - A POTENTIAL COORDINATOR OF NUCLEAR EVENTS SO CANCER CELLS-A MONTHLY REVIEW LA English DT Review ID HEAT-SHOCK PROTEINS; SV40 T-ANTIGEN; C-FOS; PHOSPHORYLATION; CELL; EXTRACTS; INVITRO; SITES; P53 AB DNA-PK is a moderately abundant serine/threonine protein kinase found in the nucleus of a wide range of eukaryotic cells. It is one of the few known cellular enzymes whose activity is regulated directly by DNA. Many DNA binding proteins, including a number of transcription factors, are substrates for DNA-PK in vitro. We suggest that this kinase may coordinate signal transduction pathways and nuclear events, including transcription, in response to changes in DNA or chromatin state. RP BROOKHAVEN NATL LAB, DEPT BIOL, UPTON, NY 11973 USA. FU NIAID NIH HHS [AI25170]; NIGMS NIH HHS [GM35945] NR 34 TC 40 Z9 40 U1 0 U2 2 PU COLD SPRING HARBOR LAB PRESS, PUBLICATIONS DEPT PI COLD SPRING HARBOR PA 1 BUNGTOWN RD, COLD SPRING HARBOR, NY 11724 USA SN 1042-2196 J9 CANCER CELL-MON REV PD SEP PY 1991 VL 3 IS 9 BP 341 EP 346 PG 6 WC Oncology; Medicine, Research & Experimental SC Oncology; Research & Experimental Medicine GA GG635 UT WOS:A1991GG63500002 PM 1751287 ER PT J AU HALLAHAN, DE VIRUDACHALAM, S SHERMAN, ML HUBERMAN, E KUFE, DW WEICHSELBAUM, RR AF HALLAHAN, DE VIRUDACHALAM, S SHERMAN, ML HUBERMAN, E KUFE, DW WEICHSELBAUM, RR TI TUMOR-NECROSIS-FACTOR GENE-EXPRESSION IS MEDIATED BY PROTEIN-KINASE-C FOLLOWING ACTIVATION BY IONIZING-RADIATION SO CANCER RESEARCH LA English DT Article ID PHORBOL ESTER; MOLECULAR-CLONING; CELLS; DNA; INDUCTION; INVITRO; DIFFERENTIATION; DIACYLGLYCEROL; TRANSLOCATION; CACHECTIN AB Tumor necrosis factor (TNF) production following X-irradiation has been implicated in the biological response to ionizing radiation. Protein kinase C (PKC) is suggested to participate in TNF transcriptional induction and X-ray-mediated gene expression. We therefore studied radiation-mediated TNF expression in HL-60 cells with diminished PKC activity produced by either pretreatment with protein kinase inhibitors or prolonged 12-O-tetradecanoylphorbol-13-acetate treatment. Both treatments resulted in attenuation of radiation-mediated TNF induction. Consistent with these results, we found no detectable induction of TNF expression following X-irradiation in the HL-60 variant deficient in PKC-mediated signal transduction. The rapid activation of PKC following gamma-irradiation was established using an in vitro assay measuring phosphorylation of a PKC specific substrate. A 4.5-fold increase in PKC activity occurred 15 to 30 s following irradiation, which declined to baseline at 60 s. Two-dimensional gel electrophoresis of phosphoproteins extracted from irradiated cells demonstrated in vivo phosphorylation of the PKC specific substrate M(r) 80,000 protein at 45 s following X-irradiation. These findings indicate that signal transduction via the PKC pathway is required for the induction of TNF gene expression by ionizing radiation. C1 HARVARD UNIV,SCH MED,DANA FARBER CANC INST,CLIN PHARMACOL LAB,BOSTON,MA 02115. HARVARD UNIV,SCH MED,BOSTON,MA 02115. ARGONNE NATL LAB,DIV BIOL & MED RES,ARGONNE,IL 60439. UNIV CHICAGO,DEPT MOLEC GENET & CELL BIOL,CHICAGO,IL 60637. RP HALLAHAN, DE (reprint author), UNIV CHICAGO,PRITZKER SCH MED,DEPT RADIAT & CELL ONCOL,5841 S MARYLAND AVE,CHICAGO,IL 60637, USA. FU NCI NIH HHS [CA41068] NR 39 TC 136 Z9 139 U1 0 U2 0 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 SEP 1 PY 1991 VL 51 IS 17 BP 4565 EP 4569 PG 5 WC Oncology SC Oncology GA GC743 UT WOS:A1991GC74300011 PM 1873801 ER PT J AU LASTER, BH KAHL, SB POPENOE, EA PATE, DW FAIRCHILD, RG AF LASTER, BH KAHL, SB POPENOE, EA PATE, DW FAIRCHILD, RG TI BIOLOGICAL EFFICACY OF BORONATED LOW-DENSITY-LIPOPROTEIN FOR BORON NEUTRON-CAPTURE THERAPY AS MEASURED IN CELL-CULTURE SO CANCER RESEARCH LA English DT Article ID B-10(N,ALPHA)LI-7 REACTION; RECEPTOR; CHOLESTEROL; LDL AB Low-density lipoproteins (LDLs) are known to be internalized by the cell through receptor-mediated mechanisms. There is evidence that LDLs may be taken up avidly by tumor cells to provide cholesterol for the synthesis of cell membranes. Thus, the possibility exists that LDLs may provide an ideal vehicle for the transport of boron to tumor cells for boron neutron capture therapy. A boronated analogue of LDL has recently been synthesized for possible application in boron neutron capture therapy. The analogue was tested in cell culture for uptake and biological efficacy in the thermal neutron beam at the Brookhaven Medical Research Reactor. It was found that boron concentrations 10 times higher than that required in tumors for boron neutron capture therapy were easily obtained and that the amount of uptake was consistent with a receptor-mediated binding mechanism. The measured intracellular concentration of approximately 240-mu-g B-10/g cells is significantly higher than that obtained with any other boron compound previously evaluated for possible clinical application. C1 UNIV CALIF SAN FRANCISCO,SCH PHARM,DEPT PHARMACEUT CHEM,SAN FRANCISCO,CA 94143. UNIV HOSP STONY BROOK,DEPT RADIAT ONCOL,STONY BROOK,NY 11794. RP LASTER, BH (reprint author), ASSOCIATED UNIV INC,BROOKHAVEN NATL LAB,DEPT MED,LONG ISL,NY 11973, USA. FU NCI NIH HHS [CA41487] NR 26 TC 45 Z9 45 U1 0 U2 0 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 SEP 1 PY 1991 VL 51 IS 17 BP 4588 EP 4593 PG 6 WC Oncology SC Oncology GA GC743 UT WOS:A1991GC74300015 PM 1873803 ER PT J AU GRIFFITHS, GL GOLDENBERG, DM KNAPP, FF CALLAHAN, AP CHANG, CH HANSEN, HJ AF GRIFFITHS, GL GOLDENBERG, DM KNAPP, FF CALLAHAN, AP CHANG, CH HANSEN, HJ TI DIRECT RADIOLABELING OF MONOCLONAL-ANTIBODIES WITH GENERATOR-PRODUCED RE-188 FOR RADIOIMMUNOTHERAPY - LABELING AND ANIMAL BIODISTRIBUTION STUDIES SO CANCER RESEARCH LA English DT Article ID BIFUNCTIONAL CHELATING-AGENTS; CARCINOEMBRYONIC ANTIGEN; CARCINOMA XENOGRAFTS; MICE; FRAGMENTS AB The use of Re-188 from an alumina-based W-188/Re-188 generator has been investigated for antibody radiolabeling. It was found that, with simple labeling techniques, Re-188 can be used immediately after elution. The direct radiolabeling of intact antibodies with Re-188 is described. Lyophilized antibody preparations have been reconstituted with Re-188 taken directly from the generator at specific activities of up to 15 mCi of Re-188 per mg of antibody. Radiolabeling yields of 90 to 98% have been obtained, with the incorporation rate being dependent upon time and the relative concentrations of the reagents. It was determined that the conjugates were immunoreactive and stable when challenged by serum in vitro, with Re-188-immunoglobulin G showing adequate resistance to reoxidation with no transfer of Re-188 to serum protein. Re-188-antibody conjugates were shown to clear from the blood faster than the corresponding I-131-labeled antibody, giving rise to good tumor/nontumor ratios at 24 to 72 h postinjection, while serum samples taken from the animals have shown that the circulating Re-188 remained bound to immunoglobulin G. The combination of the technologies of the W-188/Re-188 generator, the direct labeling methodology, and the use of single-vial lyophilized antibody makes the use of Re-188-radiolabeled monoclonal antibodies a simple and convenient method of cancer radioimmunotherapy with a beta-emitting radionuclide. C1 IMMUNOMED INC,WARREN,NJ 07060. OAK RIDGE NATL LAB,OAK RIDGE,TN 37831. CTR MOLEC MED & IMMUNOL,NEWARK,NJ 07103. FU NCI NIH HHS [CA 39841] NR 33 TC 93 Z9 102 U1 0 U2 0 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 SEP 1 PY 1991 VL 51 IS 17 BP 4594 EP 4602 PG 9 WC Oncology SC Oncology GA GC743 UT WOS:A1991GC74300016 PM 1873804 ER PT J AU TISCHLER, AN LEVINE, GA BARTLEY, JC AF TISCHLER, AN LEVINE, GA BARTLEY, JC TI METABOLISM OF BENZO[A]PYRENE AND BENZO[A]PYRENE-7,8-DIHYDRODIOL IN HUMAN MAMMARY EPITHELIAL-CELLS - FEEDBACK INHIBITION BY 7-HYDROXYBENZO[A]PYRENE SO CARCINOGENESIS LA English DT Article ID DERIVATIVES; ACTIVATION; CANCER AB The metabolism of benzo[a]pyrene (B[a]P) and (-)-trans-benzo[a]pyrene-7,8-dihydrodiol (B[a]P-diol) was compared in human mammary epithelial cells (HMEC) grown in serum-free medium, MCDB-170. Conversion of B[a]P-diol to the carcinogen (+)-benzo[a]pyrene-7,8-dihydroxy-9,10-epoxide (BPDE), as measured by analysis of their tetraol hydrolysis products, occurred much more efficiently in cultures incubated with [H-3]B[a]P-diol than in cultures incubated with [H-3]B[a]P. In cultures pretreated with unlabeled B[a]P (24 h, 400 nM), the conversion of [H-3]B[a]P-diol to [H-3]tetraols is inhibited 49%, while the conversion of [H-3]B[a]P to [H-3]B[a]P-diol is not affected. These observations led to the identification of a major B[a]P-derived metabolite as 7-hydroxybenzo[a]pyrene (B[a]P-7-ol), which was found to be an extremely potent and selective inhibitor of the conversion of B[a]P-diol to BPDE, with a K(I) estimated at 3 - 12 nM. Thus B[a]P activation in HMEC appears to be significantly limited by a feedback inhibition pathway induced by B[a]P-7-ol. The potency and selectivity of the B[a]P-7-ol-induced inhibition suggests that the diol to diolepoxide conversion is affected by a selective oxygenase in HMEC, rather than a non-enzymatic, peroxy radical-induced mechanism. B[a]P-7-ol should prove to be a valuable tool in the study of B[a]P carcinogenesis. RP TISCHLER, AN (reprint author), UNIV CALIF BERKELEY LAWRENCE BERKELEY LAB,DIV CELL & MOLEC BIOL,BERKELEY,CA 94720, USA. NR 18 TC 6 Z9 6 U1 0 U2 0 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 SEP PY 1991 VL 12 IS 9 BP 1539 EP 1543 DI 10.1093/carcin/12.9.1539 PG 5 WC Oncology SC Oncology GA GG045 UT WOS:A1991GG04500002 PM 1909936 ER PT J AU SCHWARTZ, JL ASHMAN, CR ATCHER, RW SEDITA, BA SHADLEY, JD TANG, J WHITLOCK, JL ROTMENSCH, J AF SCHWARTZ, JL ASHMAN, CR ATCHER, RW SEDITA, BA SHADLEY, JD TANG, J WHITLOCK, JL ROTMENSCH, J TI DIFFERENTIAL LOCUS SENSITIVITY TO MUTATION-INDUCTION BY IONIZING-RADIATIONS OF DIFFERENT LETS IN CHINESE-HAMSTER OVARY K1 CELLS SO CARCINOGENESIS LA English DT Article ID ACCELERATED HEAVY-IONS; MOUSE LYMPHOMA-CELLS; MAMMALIAN-CELLS; ALPHA-PARTICLES; MOLECULAR CHARACTERIZATION; LET RADIATIONS; STRAND BREAKS; CELLULAR DNA; GAMMA-RAYS; TK LOCUS AB Mutation induction after exposures to 250 kVp X-rays, alpha-particles from the radon daughter Bi-212, and fission-spectrum neutrons from the JANUS reactor was studied in Chinese hamster ovary (CHO) K1 cells and in CHO-10T5, a K1 derivative containing the bacterial gene xanthine-guanine phosphoribosyl transferase (gpt). Mutation induction was analyzed at three genetic loci: the gpt locus, the hypoxanthine-guanine phosphoribosyl transferase (hprt) locus, and the thymidine kinase (tk) locus. After X-irradiation, mutants were induced at the tk loci at approximately 8-9 times the rate of mutant induction at the hprt locus, and the rate of mutant induction at the gpt locus was 8-10 times greater than that at the hprt locus. Neutron and alpha-radiation were more effective mutagenic agents. Mutant frequencies were approximately 4- to 6-fold higher than for X-rays at the hprt and gpt loci and > 12-fold greater than X-rays at the tk locus. The greater sensitivity of the tk locus to mutation induction by ionizing radiation (especially neutron and alpha-particle radiation) compared to the hprt locus is likely to be due to the recovery of an additional class of mutants, possibly ones containing larger-sized mutational events. Approximately half of the X-ray-induced tk-/- mutants were small-colony mutants, and 75% of the alpha- and neutron-induced tk-/- mutants were small-colony mutants. The increase in the proportion of small-colony mutants seen with increasing radiation linear energy transfer (LET) suggests that the radiation quality influenced the type of mutation recovered at this locus. There is probably a different reason for the hypersensitivity of the gpt locus because the frequency of gpt mutants, compared to the hprt locus, was independent of radiation quality. Therefore, the LET dependence of mutant induction is gene specific and not necessarily related to the size of deletion recoverable. C1 ARGONNE NATL LAB,DIV CHEM,ARGONNE,IL 60439. UNIV CHICAGO,DEPT RADIAT & CELLULAR ONCOL,CHICAGO,IL 60637. UNIV CHICAGO,DEPT OBSTET & GYNECOL,CHICAGO,IL 60637. RP SCHWARTZ, JL (reprint author), ARGONNE NATL LAB,DIV BIOL & MED RES,ARGONNE,IL 60439, USA. OI Atcher, Robert/0000-0003-4656-2247 FU NCI NIH HHS [CA45336] NR 50 TC 14 Z9 14 U1 0 U2 0 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 SEP PY 1991 VL 12 IS 9 BP 1721 EP 1726 DI 10.1093/carcin/12.9.1721 PG 6 WC Oncology SC Oncology GA GG045 UT WOS:A1991GG04500030 PM 1909939 ER PT J AU OSTROWSKI, LE VONWRONSKI, MA BIGNER, SH RASHEED, A SCHOLD, SC BRENT, TP MITRA, S BIGNER, DD AF OSTROWSKI, LE VONWRONSKI, MA BIGNER, SH RASHEED, A SCHOLD, SC BRENT, TP MITRA, S BIGNER, DD TI EXPRESSION OF 06-METHYLGUANINE-DNA METHYLTRANSFERASE IN MALIGNANT HUMAN GLIOMA CELL-LINES SO CARCINOGENESIS LA English DT Article ID O-6-ALKYLGUANINE-DNA ALKYLTRANSFERASE ACTIVITY; BRAIN-TUMORS; O-6-METHYLGUANINE-DNA METHYLTRANSFERASE; GLIOBLASTOMA-MULTIFORME; REPAIR; GENE; XENOGRAFTS; HETEROZYGOSITY; CHROMOSOME-10; PROCARBAZINE AB When animals are treated with carcinogenic agents that alkylate O6-guanine residues, the incidence of tumors in specific tissues often relates inversely to the level of the DNA repair enzyme O6-methylguanine-DNA methyltransferase (MGMT) present in the tissue. Similarly, the hypersensitivity to anticancer chloroethylnitrosoureas of some human tumor cell lines is believed to result from their deficiency in MGMT. We have undertaken a comprehensive investigation of MGMT expression in a panel of nine characterized human glioma cell lines. Methyltransferase activity determined by incubating protein extracts of these glioma lines with [H-3]methylated DNA ranged from undetectable in six lines (the Mer- phenotype) to > 0.8 pmol/mg in two lines (U-373 MG and D-392 MG). MGMT protein was undetectable in Western blots of the Mer- cell extracts probed with specific anti-MGMT monoclonal antibodies. Consistent with these results, steady-state levels of MGMT mRNA, determined by Northern blot analysis, were detectable only in the three Mer+ glioma lines (U-373 MG, D-392 MG, D-263 MG). Southern analysis of EcoRI-digested DNA probed with MGMT cDNA revealed no amplification, rearrangement or deletions of the MGMT gene in any of the glioma cell lines. This is the first report that examines MGMT expression at the biochemical, molecular and genetic levels in a particular tumor type. These studies suggest that transcriptional regulation is the basis of the Mer- phenotype in these malignant human glioma cell lines, since no gross structural or quantitative abnormalities of the MGMT gene were seen in the phenotypically Mer- lines. C1 DUKE UNIV, MED CTR, DEPT PATHOL, BOX 3156, DURHAM, NC 27710 USA. OAK RIDGE NATL LAB, DIV BIOL, OAK RIDGE, TN 37831 USA. ST JUDE CHILDRENS RES HOSP, DEPT BIOCHEM & CLIN PHARMACOL, MEMPHIS, TN 38101 USA. DUKE UNIV, MED CTR, PREUSS BRAIN TUMOR RES LABS, DURHAM, NC 27710 USA. UNIV TENNESSEE, OAK RIDGE GRAD SCH BIOMED SCI, OAK RIDGE, TN 37830 USA. FU NCI NIH HHS [CA 32672, CA 11898]; NINDS NIH HHS [NS 20023] NR 44 TC 39 Z9 39 U1 0 U2 0 PU OXFORD UNIV PRESS PI OXFORD PA GREAT CLARENDON ST, OXFORD OX2 6DP, ENGLAND SN 0143-3334 J9 CARCINOGENESIS JI Carcinogenesis PD SEP PY 1991 VL 12 IS 9 BP 1739 EP 1744 DI 10.1093/carcin/12.9.1739 PG 6 WC Oncology SC Oncology GA GG045 UT WOS:A1991GG04500033 PM 1893534 ER PT J AU MARTINSGREEN, M TILLEY, C SCHWARZ, R HATIER, C BISSELL, MJ AF MARTINSGREEN, M TILLEY, C SCHWARZ, R HATIER, C BISSELL, MJ TI WOUND-FACTOR-INDUCED AND CELL-CYCLE PHASE-DEPENDENT EXPRESSION OF 9E3/CEF4, THE AVIAN GRO GENE SO CELL REGULATION LA English DT Article ID STIMULATORY ACTIVITY; TRANSFORMED-CELLS; PLATELET PROTEIN; BETA; FIBROBLASTS; GRANULATION; INHIBITION; CULTURE; TISSUE; KINASE AB The gro genes encode for secreted proteins with sequence homologies to inflammatory mediators. Little is known about the function of these proteins or their regulation. The chicken gro (9E3/CEF4) is expressed abundantly in the cells of proliferating cultures but at very low levels in confluent cultures. In vivo, this gene is expressed in connective tissue and overexpressed at sites of injury, especially in areas of neovascularization. Here we provide a bridge between these observations by examining in culture the effect on 9E3 expression and DNA synthesis induced by cell damage and by addition of factors known to be released on wounding. We mimicked wounding by scraping swaths across confluent cultures of embryonic fibroblasts and determined the time dependence of expression of 9E3 mRNA and incorporation of H-3-thymidine. We find that 9E3 is (1) transiently expressed after "wounding" or serum-stimulation; (2) expressed in a cell cycle phase-dependent manner; it is triggered during the G0-G1 transition or early in G1 and subsides during S-phase; and (3) stimulated to high levels by a-fibroblast growth factor (aFGF), bFGF, transforming growth factor-alpha (TGF-alpha), and TGF-beta, to intermediate levels by platelet-derived growth factor and not stimulated by epidermal growth factor. We also find that cells that are constantly cycling do not express 9E3, indicating that they skip either the portion of the cell cycle where 9E3 is induced or that they constituitively express a repressor of transcription or an RNA-degrading enzyme. Taken together, these observations suggest that the product of this gene could play more than one role in vivo. For example, in normal tissues the 9E3 protein could be involved in the exit of cells from the resting stage, whereas during wound healing the secreted protein or its cleavage products also could play a role in angiogenesis. RP MARTINSGREEN, M (reprint author), UNIV CALIF BERKELEY LAWRENCE BERKELEY LAB,DIV CELL & MOLEC BIOL,BERKELEY,CA 94720, USA. NR 34 TC 16 Z9 17 U1 0 U2 0 PU AMER SOC CELL BIOL PI BETHESDA PA PUBL OFFICE 9650 ROCKVILLE PIKE, BETHESDA, MD 20814 SN 1044-2030 J9 CELL REGUL PD SEP PY 1991 VL 2 IS 9 BP 739 EP 752 PG 14 WC Cell Biology SC Cell Biology GA GF375 UT WOS:A1991GF37500007 PM 1742344 ER PT J AU MCKELVEY, M SHARMA, R ONG, E BURR, G GLAUNSINGER, W AF MCKELVEY, M SHARMA, R ONG, E BURR, G GLAUNSINGER, W TI DYNAMIC ATOMIC-LEVEL OBSERVATION OF STAGING PHENOMENA IN SILVER AND MERCURY INTERCALATES OF TITANIUM DISULFIDE SO CHEMISTRY OF MATERIALS LA English DT Note ID GRAPHITE; INSITU C1 UNIV CALIF LOS ALAMOS SCI LAB,MANUEL LUJAN JR NEUTRON SCATTERING CTR,LOS ALAMOS,NM 87545. ARIZONA STATE UNIV,DEPT CHEM,TEMPE,AZ 85287. RP MCKELVEY, M (reprint author), ARIZONA STATE UNIV,CTR SOLID STATE SCI,TEMPE,AZ 85287, USA. NR 29 TC 10 Z9 10 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 SEP-OCT PY 1991 VL 3 IS 5 BP 783 EP 786 DI 10.1021/cm00017a009 PG 4 WC Chemistry, Physical; Materials Science, Multidisciplinary SC Chemistry; Materials Science GA GH636 UT WOS:A1991GH63600009 ER PT J AU VAUGHEY, JT THIEL, JP HASTY, EF GROENKE, DA STERN, CL POEPPELMEIER, KR DABROWSKI, B HINKS, DG MITCHELL, AW AF VAUGHEY, JT THIEL, JP HASTY, EF GROENKE, DA STERN, CL POEPPELMEIER, KR DABROWSKI, B HINKS, DG MITCHELL, AW TI SYNTHESIS AND STRUCTURE OF A NEW FAMILY OF CUPRATE SUPERCONDUCTORS - LNSR2CU2GAO7 SO CHEMISTRY OF MATERIALS LA English DT Article ID CU-O SYSTEM; HIGH-TC SUPERCONDUCTIVITY; CRYSTAL-STRUCTURE; X-RAY; COMPOUND SYSTEM; NEUTRON METHODS; SINGLE-CRYSTAL; COPPER-OXIDE; SUBSTITUTION; PHASE AB The synthesis of layered cuprates with nonmagnetic and fixed oxidation state cations separating the Cu-O planes has, until now, led to nonsuperconducting materials. A new series of layered copper oxides with the general formula LnSr2Cu2GaO7 (Ln = La-Yb, Y) has been synthesized. The structure has been studied by both powder neutron diffraction and single-crystal X-ray analysis. The typical unit cell is a almost-equal-to 22.8 angstrom, b almost-equal-to 5.5 angstrom, c almost-equal-to 5.4 angstrom, in space group Ima2 (No. 46). The structure is closely related to that of YBa2Cu3O7 and can be described as replacement of the square-planar copper with a tetrahedral gallium. The larger lanthanides are distributed unevenly over the two A-cation sites, whereas the smaller lanthanides occupy the site between the cuprate planes. We have been able to introduce superconductivity in the Y-Sr-Cu-Ga-O system by appropriate doping with calcium and annealing. C1 NORTHWESTERN UNIV,SCI & TECHNOL CTR SUPERCONDUCT,EVANSTON,IL 60208. NORTHWESTERN UNIV,MAT RES CTR,EVANSTON,IL 60208. NO ILLINOIS UNIV,DEPT PHYS,DE KALB,IL 60115. ARGONNE NATL LAB,DIV MAT SCI,ARGONNE,IL 60439. NORTHWESTERN UNIV,DEPT CHEM,EVANSTON,IL 60208. OI Vaughey, John/0000-0002-2556-6129 NR 62 TC 113 Z9 113 U1 2 U2 11 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 SN 0897-4756 J9 CHEM MATER JI Chem. Mat. PD SEP-OCT PY 1991 VL 3 IS 5 BP 935 EP 940 DI 10.1021/cm00017a032 PG 6 WC Chemistry, Physical; Materials Science, Multidisciplinary SC Chemistry; Materials Science GA GH636 UT WOS:A1991GH63600032 ER PT J AU BARTRAM, ME MICHALSKE, TA ROGERS, JW MAYER, TM AF BARTRAM, ME MICHALSKE, TA ROGERS, JW MAYER, TM TI CHEMISORPTION OF TRIMETHYLALUMINUM AND AMMONIA ON SILICA - MECHANISMS FOR THE FORMATION OF AL-N BONDS AND THE ELIMINATION OF METHYL-GROUPS BONDED TO ALUMINUM SO CHEMISTRY OF MATERIALS LA English DT Article ID LOW-TEMPERATURE GROWTH; DEHYDROXYLATED SILICA; FILMS; SPECTROSCOPY; HYDRAZINE; ELECTRON; KINETICS; SURFACES; NITRIDE; GAN AB Infrared spectroscopy and temperature-programmed desorption (TPD) have been used to study the formation and decomposition of a potential AlN precursor on the surface of silica. At 300 K, ammonia reacts with the monomethylaluminum surface complex produced by trimethylaluminum chemisorption to form a structure analogous to the TMA:NH3 adduct known in the condensed phase. The surface adduct is stable in high vacuum and demonstrates that strong Al-N bonds can be produced on the surface at low temperatures. Additional Al-N bonds are formed when these species react to yield -NH-2- (amino) groups that bridge between aluminum centers. Thermal decomposition of the methylaluminum:ND3 surface adduct leads to the desorption of CH-3D below 600 K, suggesting that the formation of bridging amino groups is the coproduct of a reaction in which ammonia directly hydrogenates methyl groups bonded to aluminum. Collectively, these results imply that adjacent adducts decompose via an interadsorbate reaction mechanism that synergistically decreases the source of carbon contamination and promotes the formation of contiguous Al-N bonds on the surface at low temperatures. TPD results and the coverage dependence of bridging amino formation suggest that the extent of Al-N bonding is limited by the desorption of ammonia and by the proximity and orientation of the surface adduct. RP BARTRAM, ME (reprint author), SANDIA NATL LABS,ALBUQUERQUE,NM 87185, USA. NR 38 TC 34 Z9 34 U1 3 U2 8 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 SN 0897-4756 J9 CHEM MATER JI Chem. Mat. PD SEP-OCT PY 1991 VL 3 IS 5 BP 953 EP 960 DI 10.1021/cm00017a035 PG 8 WC Chemistry, Physical; Materials Science, Multidisciplinary SC Chemistry; Materials Science GA GH636 UT WOS:A1991GH63600035 ER PT J AU MARLAND, G AF MARLAND, G TI TROPICAL FORESTS AND THE GREENHOUSE-EFFECT - A MANAGEMENT RESPONSE - COMMENT SO CLIMATIC CHANGE LA English DT Editorial Material RP MARLAND, G (reprint author), OAK RIDGE NATL LAB,DIV ENVIRONM SCI,POB 2008,OAK RIDGE,TN 37831, USA. NR 10 TC 1 Z9 1 U1 0 U2 0 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 SEP PY 1991 VL 19 IS 1-2 BP 227 EP 232 DI 10.1007/BF00142230 PG 6 WC Environmental Sciences; Meteorology & Atmospheric Sciences SC Environmental Sciences & Ecology; Meteorology & Atmospheric Sciences GA GH182 UT WOS:A1991GH18200023 ER PT J AU ROBINSON, MT BUTLER, R KRAUSS, RM AF ROBINSON, MT BUTLER, R KRAUSS, RM TI ASSOCIATION OF A GENETIC-POLYMORPHISM IN HUMAN APOLIPOPROTEIN-B-100 WITH INTERMEDIATE DENSITY LIPOPROTEIN CONCENTRATIONS SO CLINICAL GENETICS LA English DT Article DE AG BLOOD GROUPS; ANALYTICAL ULTRACENTRIFUGATION; ANTIGENIC DETERMINANTS; LOW DENSITY LIPOPROTEINS ID CORONARY-ARTERY DISEASE; FRAGMENT LENGTH POLYMORPHISM; B-GENE; LIPID-LEVELS; SERUM-CHOLESTEROL; MYOCARDIAL-INFARCTION; DNA POLYMORPHISMS; CATABOLIC RATE; AG; LOCUS AB Immunochemical techniques have been used to identify five antigenic (Ag) sites on apolipoprotein B-100 (apoB), the major protein constituent of very low density (VLDL), intermediate density (IDL), and low density lipoproteins (LDL). Each Ag site results from allelic variation at a specific locus of the apoB gene. In the present study, we assessed whether variations in the five Ag loci were associated with concentrations of plasma lipids or lipoprotein fractions measured by analytical ultracentrifugation in a group of 44 healthy men. Pair-wise analyses of the Ag markers revealed that Ag(al/d), in association with either Ag(x/y) or Ag(t/z), is significantly related to plasma IDL-mass concentrations. In this cohort we detected no significant associations of the Ag alleles (singly or in combination) with plasma total cholesterol, triglycerides, LDL-cholesterol, HDL-cholesterol, or mass of total VLDL or LDL. These results suggest that genetic variations in the apoB molecule may predispose to variations in concentrations of IDL that could have consequences for atherosclerotic risk. C1 UNIV CALIF BERKELEY LAWRENCE BERKELEY LAB,DIV RES MED & RADIAT BIOPHYS,DONNER LAB,1 CYCLOTRON RD,BERKELEY,CA 94720. SERV TRANSFUS CRS,CENT LAB,BERN,SWITZERLAND. FU NHLBI NIH HHS [HL 18574] NR 30 TC 2 Z9 2 U1 0 U2 0 PU MUNKSGAARD INT PUBL LTD PI COPENHAGEN PA 35 NORRE SOGADE, PO BOX 2148, DK-1016 COPENHAGEN, DENMARK SN 0009-9163 J9 CLIN GENET JI Clin. Genet. PD SEP PY 1991 VL 40 IS 3 BP 178 EP 185 PG 8 WC Genetics & Heredity SC Genetics & Heredity GA GL216 UT WOS:A1991GL21600001 PM 1773531 ER PT J AU JADACH, S WARD, BFL WAS, Z AF JADACH, S WARD, BFL WAS, Z TI THE MONTE-CARLO PROGRAM KORALZ, VERSION 3.8, FOR THE LEPTON OR QUARK PAIR PRODUCTION AT LEP SLC ENERGIES SO COMPUTER PHYSICS COMMUNICATIONS LA English DT Article ID RADIATIVE-CORRECTIONS; STANDARD MODEL; Z0; SIMULATION AB The Monte Carlo program for tau-pair production and decay applicable to the experiments in e+e- colliders in the Z resonance energy range is presented. The program includes initial-state bremsstrahlung corrections up to O(alpha-2) (with exclusive exponentiation), final-state O(alpha) bremsstrahlung and O(alpha) electroweak corrections. The following tau-decay modes can be generated: tau +/- --> nu-nu-eBAR +/-, nu-nu-mu-BAR +/-, nu-pi +/-, nu-rho +/-, nu-K1 +/-, nu-K* +/-, nu-a1 +/-, nu-4-pi +/-,0, nu-5-pi +/-,0, nu-6-pi +/-,0 including leading logarithmic radiative corrections in decays. The program can be also used for the generation of the final states different from tau+tau- pairs,i.e. is able to generate mu+mu-, nu-nu-BAR, uuBAR, ddBAR, ccBAR, ssBAR and bbBAR final states. C1 STANFORD UNIV,STANFORD LINEAR ACCELERATOR CTR,STANFORD,CA 94309. UNIV TENNESSEE,DEPT PHYS & ASTRON,KNOXVILLE,TN 37996. INST NUCL PHYS,PL-30055 KRAKOW,POLAND. RP JADACH, S (reprint author), CERN,DIV THEORY,CH-1211 GENEVA 23,SWITZERLAND. NR 40 TC 173 Z9 174 U1 1 U2 1 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0010-4655 J9 COMPUT PHYS COMMUN JI Comput. Phys. Commun. PD SEP-OCT PY 1991 VL 66 IS 2-3 BP 276 EP 292 DI 10.1016/0010-4655(91)90077-X PG 17 WC Computer Science, Interdisciplinary Applications; Physics, Mathematical SC Computer Science; Physics GA GH799 UT WOS:A1991GH79900016 ER PT J AU MACLAREN, JM CLOUGHERTY, DP MCHENRY, ME DONOVAN, MM AF MACLAREN, JM CLOUGHERTY, DP MCHENRY, ME DONOVAN, MM TI PARAMETERIZED LOCAL SPIN-DENSITY EXCHANGE-CORRELATION ENERGIES AND POTENTIALS FOR ELECTRONIC-STRUCTURE CALCULATIONS .1. ZERO TEMPERATURE FORMALISM SO COMPUTER PHYSICS COMMUNICATIONS LA English DT Article ID GROUND-STATE; ATOMS AB Commonly used approximate forms for the exchange-correlation energy and potential within the local density approximation are summarised, and FORTRAN code is included for the evaluation of these various forms. Included are the following: X-alpha, Kohn-Sham-Gaspar, Hedin-Lundqvist, Gunnarsson-Lundqvist-Wilkins, Janak-Moruzzi-Williams, Von Barth-Hedin, Ceperley-Alder (Perdew-Zunger), and Ceperly-Alder (Vosko-Wilk-Nusair). Both the Vosko-Wilk-Nusair and the Von Barth-Hedin expressions for spin interpolation between paramagnetic and ferromagnetic limits are also provided. C1 UNIV CALIF LOS ALAMOS SCI LAB,DIV MAT SCI & TECHNOL,LOS ALAMOS,NM 87545. RI McHenry, Michael/B-8936-2009; Clougherty, Dennis/A-4519-2008 OI Clougherty, Dennis/0000-0002-7299-4898 NR 17 TC 6 Z9 6 U1 0 U2 1 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0010-4655 J9 COMPUT PHYS COMMUN JI Comput. Phys. Commun. PD SEP-OCT PY 1991 VL 66 IS 2-3 BP 383 EP 391 DI 10.1016/0010-4655(91)90084-X PG 9 WC Computer Science, Interdisciplinary Applications; Physics, Mathematical SC Computer Science; Physics GA GH799 UT WOS:A1991GH79900023 ER PT J AU SRINIVASAN, V PADGETT, RA CHOUDHURY, A AF SRINIVASAN, V PADGETT, RA CHOUDHURY, A TI SULFIDATION BEHAVIOR OF FE-25CR-20NI-3SI IN H2/H2O/H2S/AR AT 700-DEGREES-C SO CORROSION LA English DT Article DE ALLOYING; AUGER ELECTRON; CORROSION RESISTANCE; OXIDATION; STEELS; SULFIDATION; MIXED GAS CORROSION; SI-EFFECT; AND FE-25CR-20NI-3SI ID STAINLESS-STEEL; OXIDATION BEHAVIOR; TEMPERATURE; SILICON; ENVIRONMENTS; TRANSPORT; CHROMIUM; ALLOYS; SULFUR; SCALES AB The isothermal and cyclic sulfidation behavior of Fe-25Cr-20Ni-3Si and Fe-25Cr-20Ni (wt%) was studied at 700-degrees-C in several H-2/H2O/H2S/Ar gas mixtures. A range of partial pressures of oxygen, 1.17 x 10(-20) to 1.18 x 10(-22) atm was used at a constant sulfur potential of 1.22 x 10(-8) atm. Alloy coupons with and without preoxidation were exposed to the gas mixtures for times up to 192 h. Alloys were preoxidated for up to 96 h at 700-degrees-C in an H-2/H2O/Ar gas mixture with pO2 = 1.13 x 10(-20) atm. The oxide scale and corrosion products were analyzed using SEM/EDAX, XRD, SAM, and SIMS. A remarkable sulfidation resistance in the case of Si-containing alloy was observed under the conditions examined, and the interpretation of this observation is discussed. The base alloy, Fe-25Cr-20Ni, underwent sulfidation within a few minutes of exposure to the bioxidant gas mixture, beginning at the gas/scale interface. C1 OAK RIDGE NATL LAB,DIV MET & CERAM,OAK RIDGE,TN 37831. RP SRINIVASAN, V (reprint author), WESTINGHOUSE ELECT CORP,4400 ALAFAYA TRAIL,ORLANDO,FL 32826, USA. NR 24 TC 2 Z9 2 U1 3 U2 9 PU NATL ASSN CORROSION ENG PI HOUSTON PA 1440 SOUTH CREEK DRIVE, HOUSTON, TX 77084-4906 SN 0010-9312 J9 CORROSION JI Corrosion PD SEP PY 1991 VL 47 IS 9 BP 703 EP 712 PG 10 WC Materials Science, Multidisciplinary; Metallurgy & Metallurgical Engineering SC Materials Science; Metallurgy & Metallurgical Engineering GA GT160 UT WOS:A1991GT16000008 ER PT J AU HE, CY MERRICK, BA MANSFIELD, BK HITE, MC DALUGE, DR SELKIRK, JK AF HE, CY MERRICK, BA MANSFIELD, BK HITE, MC DALUGE, DR SELKIRK, JK TI COMPARISON OF C-14 AMINO-ACID MIXTURE AND (S-35)METHIONINE LABELING OF CELLULAR PROTEINS FROM MOUSE FIBROBLAST C3H10T1/2 CELLS BY 2-DIMENSIONAL GEL-ELECTROPHORESIS SO ELECTROPHORESIS LA English DT Article ID CYCLIN MESSENGER-RNA; ROUS-SARCOMA VIRUS; DIMENSIONAL ELECTROPHORESIS; POSTCONFLUENCE INHIBITION; POLYACRYLAMIDE GELS; GENE-EXPRESSION; MAMMALIAN-CELL; TRANSFORMATION; POLYPEPTIDES; CHROMOSOMES AB Total cellular proteins from mouse C3H10T1/2 fibroblasts were compared by two-dimensional (2-D) gel electrophoresis after radiolabeling with [S-35]methionine (S-35-Met) or C-14-amino acids (C-14-AA). S-35-Met labeling of protein was three to four times greater than C-14-AA incorporation over a 24 h period. Automated comparative analysis of replicate fluorographs after 6, 12, and 24 h of labeling showed considerable homology between radiolabeling methods. More than 88% percent of S-35-Met and C-14-AA-labeled proteins were common at each time point. However, the total number of S-35-Met-labeled proteins dropped from 6 to 24 h while the number of C-14-AA-labeled proteins increased. Additionally, twenty-one proteins were uniquely labeled by C-14-AA that were not detectable by S-35-Met over the labeling period. Densimetric analysis showed that several S-35-Met and C-14-AA-labeled proteins exhibited time-related differences in radiolabel incorporation while most proteins remained relatively constant. Protein patterns of silver-stained gels from 6 to 24 h were highly registered and showed few qualitative differences. Proteins detected in radiolabeled gels were generally, but not always, found in silver-stained gels. Thus, S-35-Met appears better suited for short-term radiolabeling of cellular protein while more comprehensive labeling of protein occurs with C-14-AA during prolonged incubation of cell cultures under present experimental conditions. C1 OAK RIDGE NATL LAB,DIV HLTH & SAFETY RES,OAK RIDGE,TN. RP HE, CY (reprint author), NIEHS,DIV TOXICOL RES & TESTING,POB 12233,RES TRIANGLE PK,NC 27709, USA. NR 38 TC 5 Z9 5 U1 0 U2 0 PU VCH PUBLISHERS INC PI DEERFIELD BEACH PA 303 NW 12TH AVE, DEERFIELD BEACH, FL 33442-1788 SN 0173-0835 J9 ELECTROPHORESIS JI Electrophoresis PD SEP PY 1991 VL 12 IS 9 BP 658 EP 666 DI 10.1002/elps.1150120911 PG 9 WC Biochemical Research Methods; Chemistry, Analytical SC Biochemistry & Molecular Biology; Chemistry GA GJ266 UT WOS:A1991GJ26600010 PM 1752247 ER PT J AU NIKSA, S KERSTEIN, AR AF NIKSA, S KERSTEIN, AR TI FLASHCHAIN THEORY FOR RAPID COAL DEVOLATILIZATION KINETICS .1. FORMULATION SO ENERGY & FUELS LA English DT Article ID ENERGY CHAIN MODEL; BITUMINOUS COALS; VAPOR-PRESSURES; PYROLYSIS; STATE; TEMPERATURE; MIXTURES; EQUATION; NETWORK; LIQUIDS AB This theory invokes a new model of coal's chemical constitution, a four-step reaction mechanism, chain statistics, and the flash distillation analogy to explain the devolatilization of various coal types. It is called FLASHCHAIN. The constitution submodel segregates the elements into only four pseudocomponents using the ultimate analysis, the carbon aromaticity and aromatic cluster size from C-13 NMR analysis, the proton aromaticity, and the extract yield in pyridine. No functional groups appear. The theory's central premise is that the partitioning of the elements among aliphatic, heteroatomic, and aromatic constituents largely determines the devolatilization behavior of any coal type. Labile bridges comprise all aliphatic and oxygen functionalities in the coal and are the key reaction centers. The abundance of labile bridges in lignites promotes their extensive conversion to noncondensible gases, but their oxygen promotes the charring of bridges into refractory links, which inhibits fragmentation of the macromolecules into tar. Conversely, the paucity of labile bridges in low-volatility coals suppresses gas yields; these coals also have too few labile bridges for extensive fragmentation, so their tar yields are also relatively low. Charring establishes the gas flow which sweeps away tar vapor but also suppresses the subsequent fragmentation of coal macromolecules into additional tar precursors. This scheme delivers reliable yields of gas and tar and molecular weight distributions of tar for any coal at any condition, yet it requires only a few minutes per simulation on a personal microcomputer. The theory is introduced in three parts. Part 1 describes its phenomenological basis, the formulation of rate equations, and assignments of model parameters, while parts 2 and 3 are devoted to performance evaluations. In part 2, the theory's representation of broad ranges of temperature, time, heating rate, pressure, and particle size is evaluated against the extensive data base for high-volatile bituminous coals. In part 3, model predictions demonstrate that this theory depicts all of the continuous trends in the yield structure from coals across the rank spectrum. C1 SANDIA NATL LABS,COMBUST RES FACIL,LIVERMORE,CA 94550. RP NIKSA, S (reprint author), STANFORD UNIV,DEPT MECH ENGN,HIGH TEMP GASDYNAM LAB,STANFORD,CA 94305, USA. NR 48 TC 150 Z9 158 U1 6 U2 37 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 SN 0887-0624 J9 ENERG FUEL JI Energy Fuels PD SEP-OCT PY 1991 VL 5 IS 5 BP 647 EP 665 DI 10.1021/ef00029a006 PG 19 WC Energy & Fuels; Engineering, Chemical SC Energy & Fuels; Engineering GA GG929 UT WOS:A1991GG92900006 ER PT J AU MAPSTONE, JO AF MAPSTONE, JO TI EFFECT OF HYDROTHERMAL PRETREATMENT ON COAL STRUCTURE AND THE MILD GASIFICATION PROCESS SO ENERGY & FUELS LA English DT Article ID PYROLYSIS; STEAM AB A suite of coals was pretreated in steam and helium. The effect of this pretreatment on the structure and reactivity of the resulting product was examined by solvent extraction, cross-polarization magic angle spinning nuclear magnetic resonance (CP MAS NMR) spectrometry, Fourier transform infrared (FTIR) spectrometry, and steam reactivity. Hydrothermal pretreatment increased the extractive yield over that of the parent coal, indicating a likely improvement in pyrolysis yield. The effects appeared to be seam-specific rather than rank-specific. Spectral data confirmed that each coal responded differently to the treatment. RP MAPSTONE, JO (reprint author), US DOE,MORGANTOWN ENERGY TECHNOL CTR,POB 880,MORGANTOWN,WV 26507, USA. NR 5 TC 19 Z9 20 U1 0 U2 4 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 SN 0887-0624 J9 ENERG FUEL JI Energy Fuels PD SEP-OCT PY 1991 VL 5 IS 5 BP 695 EP 700 DI 10.1021/ef00029a011 PG 6 WC Energy & Fuels; Engineering, Chemical SC Energy & Fuels; Engineering GA GG929 UT WOS:A1991GG92900011 ER PT J AU JOSEPH, JT FISHER, RB MASIN, CA DYRKACZ, GR BLOOMQUIST, CA WINANS, RE AF JOSEPH, JT FISHER, RB MASIN, CA DYRKACZ, GR BLOOMQUIST, CA WINANS, RE TI COAL MACERAL CHEMISTRY .1. LIQUEFACTION BEHAVIOR SO ENERGY & FUELS LA English DT Article AB Three groups of macerals, namely liptinite, vitrinite, and inertinite, were separated from a West Virginia high-volatile bituminous coal (APCS 7 from the Argonne Premium Coal Sample Bank) by continuous flow density gradient technique and their pyrolysis and liquefaction behavior studied. The pyrolysis and liquefaction yields decreased in the order: liptinite > vitrinite > inertinite. There was no discernible interaction among the macerals during pyrolysis or liquefaction. The least reactive inertinities, which makes approximately 15% of the above coal, is projected to have little influence on conversion and product distribution of the whole coal. Therefore, inertinite removal prior to liquefaction can potentially improve process efficiency. Addition of dispersed iron catalyst did not alter the liquefaction of the liptinite, while vitrinite and inertinite gave enhanced oil yields. C1 ARGONNE NATL LAB,DIV CHEM,ARGONNE,IL 60439. RP JOSEPH, JT (reprint author), AMOCO RES CTR,AMOCO OIL RES & DEV,NAPERVILLE,IL 60566, USA. NR 15 TC 18 Z9 20 U1 0 U2 0 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 SN 0887-0624 J9 ENERG FUEL JI Energy Fuels PD SEP-OCT PY 1991 VL 5 IS 5 BP 724 EP 729 DI 10.1021/ef00029a017 PG 6 WC Energy & Fuels; Engineering, Chemical SC Energy & Fuels; Engineering GA GG929 UT WOS:A1991GG92900017 ER PT J AU MUNTEAN, JV STOCK, LM AF MUNTEAN, JV STOCK, LM TI BLOCH DECAY SOLID-STATE C-13 NMR-SPECTROSCOPY OF THE SAMARIUM IODIDE TREATED ARGONNE PREMIUM COALS SO ENERGY & FUELS LA English DT Letter ID WHOLE COALS; RESONANCE; POLARIZATION; RELIABILITY C1 ARGONNE NATL LAB,DIV CHEM,ARGONNE,IL 60439. NR 18 TC 22 Z9 22 U1 0 U2 0 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 SN 0887-0624 J9 ENERG FUEL JI Energy Fuels PD SEP-OCT PY 1991 VL 5 IS 5 BP 765 EP 767 DI 10.1021/ef00029a026 PG 3 WC Energy & Fuels; Engineering, Chemical SC Energy & Fuels; Engineering GA GG929 UT WOS:A1991GG92900026 ER PT J AU MUNTEAN, JV STOCK, LM AF MUNTEAN, JV STOCK, LM TI SOLID-STATE C-13 NMR-SPECTROSCOPY OF POCAHONTAS NO 3-COAL SO ENERGY & FUELS LA English DT Letter ID COAL C1 ARGONNE NATL LAB,DIV CHEM,ARGONNE,IL 60439. NR 15 TC 14 Z9 14 U1 0 U2 1 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 SN 0887-0624 J9 ENERG FUEL JI Energy Fuels PD SEP-OCT PY 1991 VL 5 IS 5 BP 767 EP 769 DI 10.1021/ef00029a027 PG 3 WC Energy & Fuels; Engineering, Chemical SC Energy & Fuels; Engineering GA GG929 UT WOS:A1991GG92900027 ER PT J AU CHATTERJEE, K STOCK, LM GORBATY, ML GEORGE, GN KELEMEN, SR AF CHATTERJEE, K STOCK, LM GORBATY, ML GEORGE, GN KELEMEN, SR TI XANES EVIDENCE FOR SELECTIVE ORGANIC SULFUR REMOVAL FROM ILLINOIS NO-6 COAL SO ENERGY & FUELS LA English DT Letter C1 ARGONNE NATL LAB,DIV CHEM,ARGONNE,IL 60439. EXXON RES & ENGN CO,ANNANDALE,NJ 08801. RI George, Graham/E-3290-2013 NR 11 TC 11 Z9 11 U1 0 U2 2 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 SN 0887-0624 J9 ENERG FUEL JI Energy Fuels PD SEP-OCT PY 1991 VL 5 IS 5 BP 771 EP 773 DI 10.1021/ef00029a029 PG 3 WC Energy & Fuels; Engineering, Chemical SC Energy & Fuels; Engineering GA GG929 UT WOS:A1991GG92900029 ER PT J AU JONES, DW AF JONES, DW TI HOW URBANIZATION AFFECTS ENERGY-USE IN DEVELOPING-COUNTRIES SO ENERGY POLICY LA English DT Article DE ECONOMIC DEVELOPMENTS; ENERGY-USE; URBANIZATION ID DEMAND; MEXICO AB This paper identifies mechanisms whereby urbanization affects energy consumption. Industrialization and urbanization accompany each other during economic development, but urbanization exerts a number of independent influences on energy-use. It permits economies of scale in production but requires more transportation. Food must be transported to urbanized populations and relatively smaller agricultural populations must modernize, entailing considerable increases in agricultural energy-use. In cities, a number of production activities which were domestically provided in rural areas, using human or animal energy, shift to sources outside the household, using modern energy sources. The largest single source of change in energy-use is personal transportation. Passenger transport in cities is heavily weighted towards fuel-using modes, particularly as incomes increase. To assess the overall impact, a regression analysis of 59 developing countries for 1980 is conducted. Holding constant per capita income and the extent of industrialization, the elasticity of energy consumption per capita and per dollar of GDP is between 0.35 and 0.48. RP JONES, DW (reprint author), OAK RIDGE NATL LAB,DIV ENERGY,OAK RIDGE,TN 37831, USA. NR 33 TC 79 Z9 89 U1 1 U2 26 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 SEP PY 1991 VL 19 IS 7 BP 621 EP 630 DI 10.1016/0301-4215(91)90094-5 PG 10 WC Energy & Fuels; Environmental Sciences; Environmental Studies SC Energy & Fuels; Environmental Sciences & Ecology GA GD974 UT WOS:A1991GD97400003 ER PT J AU KORTE, N AF KORTE, N TI NATURALLY-OCCURRING ARSENIC IN GROUNDWATERS OF THE MIDWESTERN UNITED-STATES SO ENVIRONMENTAL GEOLOGY AND WATER SCIENCES LA English DT Article ID ENVIRONMENT; WATER AB High concentrations of naturally occurring arsenic are present in alluvial groundwater systems in the mid-western United States. These occurrences tend to be sporadic because the arsenic is mobilized only under a narrow range of redox conditions. The reducing conditions must be sufficient to reduce and dissolve iron and manganese but not to produce sulfide. Typically, the affected aquifers are relatively high in clay content and of relatively low yield. For that reason, many of these arsenic occurrences are in aquifers supplying single families. The mechanism by which the arsenic is mobilized begins with the deposition of iron oxides during streamflow while the alluvium is being deposited. The oxides have a strong affinity for dissolved arsenic and adsorb it from the streamwater. As the alluvium is buried, it eventually becomes subject to slow groundwater movement. As conditions become more reducing, ferric oxides are reduced to soluble ferrous oxides, resulting in mobilization of the adsorbed arsenic. RP KORTE, N (reprint author), OAK RIDGE NATL LAB,DIV ENVIRONM SCI,GRAND JUNCT OFF,GRAND JUNCTION,CO 81502, USA. NR 19 TC 63 Z9 65 U1 3 U2 9 PU SPRINGER VERLAG PI NEW YORK PA 175 FIFTH AVE, NEW YORK, NY 10010 SN 0177-5146 J9 ENVIRON GEOL WATER S PD SEP-OCT PY 1991 VL 18 IS 2 BP 137 EP 141 DI 10.1007/BF01704667 PG 5 WC Environmental Sciences; Geosciences, Multidisciplinary; Water Resources SC Environmental Sciences & Ecology; Geology; Water Resources GA GE401 UT WOS:A1991GE40100008 ER PT J AU FITZNER, RE GRAY, RH AF FITZNER, RE GRAY, RH TI THE STATUS, DISTRIBUTION AND ECOLOGY OF WILDLIFE ON THE UNITED-STATES-DOE HANFORD SITE - A HISTORICAL OVERVIEW OF RESEARCH ACTIVITIES SO ENVIRONMENTAL MONITORING AND ASSESSMENT LA English DT Article AB Since the inception of the U.S. DOE Hanford Site in 1943, numerous studies have been conducted on terrestrial wildlife. Onsite contractors have focused their attention on the role of wildlife in the uptake and transport of radionuclides. Graduate students from across the nation have also completed more than 15 theses on wildlife. This paper discusses the past history of wildlife research at Hanford and the individual species of wildlife that have been observed at Hanford. Forty species of mammals, 187 species of birds, 3 species of amphibians and 9 species of reptiles have been documented on the Hanford Site to date. RP FITZNER, RE (reprint author), PACIFIC NW LAB, BOX 999, RICHLAND, WA 99352 USA. NR 0 TC 10 Z9 10 U1 1 U2 3 PU KLUWER ACADEMIC PUBL PI DORDRECHT PA SPUIBOULEVARD 50, PO BOX 17, 3300 AA DORDRECHT, NETHERLANDS SN 0167-6369 J9 ENVIRON MONIT ASSESS JI Environ. Monit. Assess. PD SEP PY 1991 VL 18 IS 3 BP 173 EP 202 DI 10.1007/BF00398698 PG 30 WC Environmental Sciences SC Environmental Sciences & Ecology GA GL242 UT WOS:A1991GL24200002 PM 24233850 ER PT J AU BRUNO, S CRISSMAN, HA BAUER, KD DARZYNKIEWICZ, Z AF BRUNO, S CRISSMAN, HA BAUER, KD DARZYNKIEWICZ, Z TI CHANGES IN CELL-NUCLEI DURING S-PHASE - PROGRESSIVE CHROMATIN CONDENSATION AND ALTERED EXPRESSION OF THE PROLIFERATION-ASSOCIATED NUCLEAR PROTEINS KI-67, CYCLIN (PCNA), P105, AND P34 SO EXPERIMENTAL CELL RESEARCH LA English DT Article ID DNA INSITU SENSITIVITY; FLOW-CYTOMETRY; ANTIGEN EXPRESSION; DENATURATION; PHOSPHORYLATION; ACTIVATION; IMMUNOFLUORESCENCE; QUANTITATION; LYMPHOCYTES; L1210 C1 NEW YORK MED COLL,CANC RES INST,VALHALLA,NY 10595. UNIV CALIF LOS ALAMOS SCI LAB,LOS ALAMOS,NM 87544. NORTHWESTERN UNIV,SCH MED,DEPT PATHOL,EVANSTON,IL 60201. RI Bruno, Silvia/B-8980-2013; OI Darzynkiewicz, Zbigniew/0000-0002-2040-7081 FU NCI NIH HHS [R37 CA23296, R01 CA28704]; NCRR NIH HHS [P41-RR01315] NR 43 TC 52 Z9 52 U1 0 U2 1 PU ACADEMIC PRESS INC JNL-COMP SUBSCRIPTIONS PI SAN DIEGO PA 525 B ST, STE 1900, SAN DIEGO, CA 92101-4495 SN 0014-4827 J9 EXP CELL RES JI Exp. Cell Res. PD SEP PY 1991 VL 196 IS 1 BP 99 EP 106 DI 10.1016/0014-4827(91)90460-C PG 8 WC Oncology; Cell Biology SC Oncology; Cell Biology GA GB516 UT WOS:A1991GB51600013 PM 1831764 ER PT J AU JUNG, HY EPSTEIN, JS DEASON, VA REUTER, WG AF JUNG, HY EPSTEIN, JS DEASON, VA REUTER, WG TI LONG WAVELENGTH IMPACT OF IZOD FRACTURE SPECIMENS - AN EXPERIMENTAL NUMERICAL INVESTIGATION SO EXPERIMENTAL MECHANICS LA English DT Article ID CRACK; MOIRE AB Elastic wave propagation fields for a stationary crack in an Izod fracture specimen have been investigated. Moire interferometry was used to obtain the asymptotic crack-tip displacement fields under Hopkinson bar loading at sampling rates on the order of 100 kHz. Mixed-mode stress-intensity factors as a function of time were extracted from the displacement data using local asymptotic extrapolation. Two-dimensional continuum finite elements were employed and agreement was found between actual experiment and two-dimensional computation. C1 IDAHO NATL ENGN LAB,IDAHO FALLS,ID 83415. RP JUNG, HY (reprint author), GEORGIA INST TECHNOL,SCH CIVIL ENGN,ATLANTA,GA 30332, USA. NR 34 TC 1 Z9 1 U1 0 U2 0 PU SOC EXPERIMENTAL MECHANICS PI BETHEL PA 7 SCHOOL STREET, BETHEL, CT 06801 SN 0014-4851 J9 EXP MECH JI Exp. Mech. PD SEP PY 1991 VL 31 IS 3 BP 281 EP 287 DI 10.1007/BF02326073 PG 7 WC Materials Science, Multidisciplinary; Mechanics; Materials Science, Characterization & Testing SC Materials Science; Mechanics GA GH495 UT WOS:A1991GH49500016 ER PT J AU TUNLID, A NIVENS, DE JANSSON, HB WHITE, DC AF TUNLID, A NIVENS, DE JANSSON, HB WHITE, DC TI INFRARED MONITORING OF THE ADHESION OF CATENARIA-ANGUILLULAE ZOOSPORES TO SOLID-SURFACES SO EXPERIMENTAL MYCOLOGY LA English DT Article DE ADHESION; CATENARIA-ANGUILLULAE; FTIR; PROTEINS; ZOOSPORES ID PHYTOPHTHORA-CINNAMOMI ZOOSPORES; PYTHIUM-APHANIDERMATUM; MONOCLONAL-ANTIBODIES; PERIPHERAL VESICLES; PALMIVORA ZOOSPORES; ENCYSTMENT; FUNGUS; SPECTROSCOPY; RECOGNITION; ADSORPTION C1 UNIV TENNESSEE,INST APPL MICROBIOL,KNOXVILLE,TN 37932. UNIV TENNESSEE,DEPT MICROBIOL,KNOXVILLE,TN 37932. UNIV LUND,DEPT ECOL MICROBIAL ECOL,S-22101 LUND,SWEDEN. OAK RIDGE NATL LAB,DIV ENVIRONM SCI,OAK RIDGE,TN. RP TUNLID, A (reprint author), UNIV LUND,DEPT ECOL CHEM ECOL & ECOTOXICOL,HELGONAVAGEN 5,S-22362 LUND,SWEDEN. NR 26 TC 21 Z9 23 U1 0 U2 4 PU ACADEMIC PRESS INC JNL-COMP SUBSCRIPTIONS PI SAN DIEGO PA 525 B ST, STE 1900, SAN DIEGO, CA 92101-4495 SN 0147-5975 J9 EXP MYCOL JI Exp. Mycol. PD SEP PY 1991 VL 15 IS 3 BP 206 EP 214 DI 10.1016/0147-5975(91)90022-6 PG 9 WC Plant Sciences; Mycology SC Plant Sciences; Mycology GA GE679 UT WOS:A1991GE67900003 ER PT J AU KRAKOWSKI, RA AF KRAKOWSKI, RA TI PROGRESS IN COMMERCIAL MAGNETIC FUSION ENERGY REACTOR DESIGNS SO FUSION TECHNOLOGY LA English DT Review DE FUSION REACTOR DESIGN; TOKAMAK; FIELD-REVERSED PINCH ID REVERSED-FIELD-PINCH; WORKSHOP; POWER; CONFIGURATIONS; SYSTEMS; JAPAN AB Two decades of fusion reactor conceptual design have led to a clearer definition of an "attractive" fusion power plant. Recent advances in commercial reactor designs have pushed in the direction of smaller, more compact systems while stressing material and configurational choices that amplify safety and environmental (S & E) advantages (e.g., inherent or passive safety and significantly reduced long-term radioactive waste). When intelligently amalgamated, compactness and favorable S & E characteristics can enable fusion power to be competitive. The history of fusion reactor conceptual design, the constituents of an attractive fusion end product, and recent progress in fusion reactor studies as embodied in the TITAN reversed-field pinch and the more recent and ongoing Advanced Reactor Innovations and Evaluation Study (ARIES) advanced tokamak reactor designs, are reviewed. The future for magnetic fusion energy can be bright if the right physics, technology, and materials research and development (R & D) choices are made now. An important ingredient in this "right choice" is design simplification and subsystem combination to achieve requisite levels of reliability and ease of maintenance, while ensuring competitive energy costs and acceptable S & E features. Significant departures from the "conventional" (i.e., the current R & D direction) tokamak physics embodiment are required to achieve these goals. RP UNIV CALIF LOS ALAMOS SCI LAB, MS F647, POB 1663, LOS ALAMOS, NM 87545 USA. NR 129 TC 12 Z9 12 U1 0 U2 4 PU AMER NUCLEAR SOC PI LA GRANGE PK PA 555 N KENSINGTON AVE, LA GRANGE PK, IL 60526 USA SN 0748-1896 J9 FUSION TECHNOL JI Fusion Technol. PD SEP PY 1991 VL 20 IS 2 BP 121 EP 143 PG 23 WC Nuclear Science & Technology SC Nuclear Science & Technology GA GC038 UT WOS:A1991GC03800001 ER PT J AU SENG, LL KU, LP AF SENG, LL KU, LP TI SHIELDING DESIGN OPTIMIZATION FOR THE COMPACT IGNITION TOKAMAK TEST CELL BUILDING SO FUSION TECHNOLOGY LA English DT Article DE SHIELDING OPTIMIZATION; COUPLED MONTE-CARLO DISCRETE ORDINATES; CONCRETE BUILDING AB Shielding optimization for the Compact Ignition Tokamak baseline test cell building design is performed to minimize the cost. The design is based on iterative calculations using one-dimensional S(N) models calibrated to the results obtained by coupling a three-dimensional Monte Carlo model to a two-dimensional S(N) model. These sophisticated models remove most conservative factors in the baseline design. When a low-sodium concrete is used as the base material, the boron concentration and the thicknesses are reduced substantially. The optimal configuration that satisfies all the shielding and structural requirements shows a cost reduction of approximately 14% ($4.1 million) relative to the baseline design. RP SENG, LL (reprint author), PRINCETON UNIV,PLASMA PHYS LAB,DIV ENGN ANAL,PRINCETON,NJ 08543, USA. NR 25 TC 0 Z9 0 U1 0 U2 0 PU AMER NUCLEAR SOCIETY PI LA GRANGE PK PA 555 N KENSINGTON AVENUE, LA GRANGE PK, IL 60525 SN 0748-1896 J9 FUSION TECHNOL JI Fusion Technol. PD SEP PY 1991 VL 20 IS 2 BP 164 EP 178 PG 15 WC Nuclear Science & Technology SC Nuclear Science & Technology GA GC038 UT WOS:A1991GC03800003 ER PT J AU NOBILE, A AF NOBILE, A TI EXPERIENCE USING METAL-HYDRIDES FOR PROCESSING TRITIUM SO FUSION TECHNOLOGY LA English DT Article DE TRITIUM STORAGE; TRITIUM COMPRESSION; TRITIUM PURIFICATION AB Two processes that use metal hydrides for tritium handling have been installed in the Savannah River Site tritium facilities and have been used in routine tritium processing operations for nearly the past 3 years. These processes represent significant demonstrations of metal hydride technology for pumping, purification (inert gas separation), storage, and compression of tritium. Pumping and purification are demonstrated with a pump/purifier that uses palladium supported on kieselguhr as the hydrogen isotope-absorbing material. Storage and compression are demonstrated in a tritium loading facility that uses LaNi4.15Al0.85 beds for tritium storage, and LaNi4.7Al0.3 and Ca0.2Mm0.8Ni5(Mm-Mischmetal) beds for tritium compression. Operating data collected during routine operation of the pump/purifier and the loading facility are presented and discussed. RP NOBILE, A (reprint author), WESTINGHOUSE SAVANNAH RIVER CO,SAVANNAH RIVER LAB,BLDG 773A,AIKEN,SC 29808, USA. NR 13 TC 10 Z9 10 U1 0 U2 2 PU AMER NUCLEAR SOCIETY PI LA GRANGE PK PA 555 N KENSINGTON AVENUE, LA GRANGE PK, IL 60525 SN 0748-1896 J9 FUSION TECHNOL JI Fusion Technol. PD SEP PY 1991 VL 20 IS 2 BP 186 EP 199 PG 14 WC Nuclear Science & Technology SC Nuclear Science & Technology GA GC038 UT WOS:A1991GC03800005 ER PT J AU FOWLER, RH MORRIS, RN ROME, JA AF FOWLER, RH MORRIS, RN ROME, JA TI A STUDY OF NEUTRAL BEAM INJECTION FOR THE ADVANCED TOROIDAL FACILITY SO FUSION TECHNOLOGY LA English DT Article DE NEUTRAL BEAMS; TORSATRON; MONTE-CARLO METHODS AB Neutral beam injection into the Advanced Toroidal Facility (ATF) is studied using Monte Carlo methods. The detailed geometry of ATF to properly calculate aperture, shine-through, orbit, and charge-exchange losses, as well as the net plasma heating, is included. Also, the beam geometry (including the source geometry), beam divergence, and focusing are carefully modeled. The dependence of plasma heating on the injection angle is determined. The results indicate that net plasma heating is lower for perpendicular injection than for tangential injection because of large orbit and charge-exchange losses. However, this difference is partially offset by the need to use a smaller aperture during tangential injection to prevent excessive heating of the vacuum vessel. Shine-through losses are significant for low-density perpendicular injection. C1 OAK RIDGE NATL LAB,DIV COMP & TELECOMMUN,MARTIN MARIETTA ENERGY SYST,OAK RIDGE,TN 37831. OAK RIDGE NATL LAB,DIV FUS ENERGY,OAK RIDGE,TN 37831. NR 7 TC 11 Z9 11 U1 0 U2 0 PU AMER NUCLEAR SOCIETY PI LA GRANGE PK PA 555 N KENSINGTON AVENUE, LA GRANGE PK, IL 60525 SN 0748-1896 J9 FUSION TECHNOL JI Fusion Technol. PD SEP PY 1991 VL 20 IS 2 BP 200 EP 207 PG 8 WC Nuclear Science & Technology SC Nuclear Science & Technology GA GC038 UT WOS:A1991GC03800006 ER PT J AU STORMS, E TALCOTTSTORMS, C AF STORMS, E TALCOTTSTORMS, C TI THE EFFECT OF HYDRIDING ON THE PHYSICAL STRUCTURE OF PALLADIUM AND ON THE RELEASE OF CONTAINED TRITIUM SO FUSION TECHNOLOGY LA English DT Note DE PALLADIUM HYDRIDE; LATTICE EXPANSION; TRITIUM CONTAMINATION; COLD FUSION ID ELECTROLYSIS AB The behavior of tritium released from a contaminated palladium cathode is determined and compared with the pattern found in cells claimed to produce tritium by a cold fusion reaction. Void space is produced in palladium when it is subjected to hydrogen absorption and desorption cycles. This void space can produce channels through which hydrogen can be lost from the cathode, thereby reducing the hydrogen concentration. This effect is influenced, in part, by impurities, the shape of the electrode, the charging rate, the concentration of hydrogen achieved, and the length of time the maximum concentration is present. C1 UNIV CALIF LOS ALAMOS SCI LAB,DIV MAT SCI & TECHNOL,LOS ALAMOS,NM 87545. RP STORMS, E (reprint author), UNIV CALIF LOS ALAMOS SCI LAB,DIV NUCL MAT TECHNOL,LOS ALAMOS,NM 87545, USA. NR 30 TC 18 Z9 18 U1 0 U2 0 PU AMER NUCLEAR SOCIETY PI LA GRANGE PK PA 555 N KENSINGTON AVENUE, LA GRANGE PK, IL 60525 SN 0748-1896 J9 FUSION TECHNOL JI Fusion Technol. PD SEP PY 1991 VL 20 IS 2 BP 246 EP 257 PG 12 WC Nuclear Science & Technology SC Nuclear Science & Technology GA GC038 UT WOS:A1991GC03800016 ER PT J AU SACHLEBEN, RA BROWN, GM SLOOP, FV ARLINGHAUS, HF ENGLAND, MW FOOTE, RS LARIMER, FW WOYCHIK, RP THONNARD, N JACOBSON, KB AF SACHLEBEN, RA BROWN, GM SLOOP, FV ARLINGHAUS, HF ENGLAND, MW FOOTE, RS LARIMER, FW WOYCHIK, RP THONNARD, N JACOBSON, KB TI RESONANCE IONIZATION SPECTROSCOPY FOR MULTIPLEX SEQUENCING OF TIN-LABELED DNA SO GENETIC ANALYSIS-BIOMOLECULAR ENGINEERING LA English DT Article AB A method is described for synthesis of a tin reagent, triethylstannylpropanoic acid (TESPA), and its attachment to oligonucleotide primers. Except for the expected mobility retardation, the presence of [Sn-116]-TESPA did not affect the sequencing ladder on electrophoresis gels. By using [Sn-120]-TESPA and [S-35]-dTTP simultaneously in the Sanger procedure, DNA bands on an electrophoresis gel were first located by autoradiography and then by resonance ionization spectroscopy to demonstrate the coincidence of the signals. Previous results using stable isotopes as labels on model compounds are now confirmed by their use in actual DNA sequencing products. C1 OAK RIDGE NATL LAB,DIV BIOL,OAK RIDGE,TN 37831. UNIV TENNESSEE,OAK RIDGE GRAD SCH BIOMED SCI,OAK RIDGE,TN 37830. ATOM SCI INC,OAK RIDGE,TN. OAK RIDGE NATL LAB,DIV HLTH & SAFETY RES,OAK RIDGE,TN 37830. OAK RIDGE NATL LAB,DIV CHEM,OAK RIDGE,TN 37831. RI Sloop, Jr., Frederick/J-2301-2016 OI Sloop, Jr., Frederick/0000-0001-6473-9507 NR 20 TC 7 Z9 7 U1 0 U2 1 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 1050-3862 J9 GENET ANAL-BIOMOL E JI Genet. Anal.-Biomol. Eng. PD SEP PY 1991 VL 8 IS 6 BP 167 EP 170 DI 10.1016/1050-3862(91)90057-X PG 4 WC Biochemical Research Methods; Biotechnology & Applied Microbiology; Genetics & Heredity SC Biochemistry & Molecular Biology; Biotechnology & Applied Microbiology; Genetics & Heredity GA GR303 UT WOS:A1991GR30300002 PM 1756066 ER PT J AU GIORDANO, TH DRUMMOND, SE AF GIORDANO, TH DRUMMOND, SE TI THE POTENTIOMETRIC DETERMINATION OF STABILITY-CONSTANTS FOR ZINC ACETATE COMPLEXES IN AQUEOUS-SOLUTIONS TO 295-DEGREES-C SO GEOCHIMICA ET COSMOCHIMICA ACTA LA English DT Article ID SODIUM-CHLORIDE SOLUTIONS; HYDROTHERMAL SOLUTIONS; ORE SOLUTIONS; 300-DEGREES-C; LEAD; 350-DEGREES-C; TEMPERATURES; HYDROLYSIS; EQUILIBRIA; SOLUBILITY AB A potentiometric method was used to determine the formation quotients of zinc acetate complexes in aqueous solutions from 50 to 295-degrees-C at ionic strengths of 0.03, 0.3, and 1.0 m. The potentiometric titrations were carried out in an externally heated, Teflon-lined concentration cell fitted with hydrogen electrodes. Formal sodium acetate concentrations of the experimental solutions ranged from 0.001 to 0.1 m with acetic acid to sodium acetate ratios ranging from 30 to 300. Sodium trifluoromethanesulfonate (F3CSO3Na) was used as a supporting electrolyte. Stoichiometries and formation quotients for the complexes ZNCH3COO+, Zn(CH3COO)2, and Zn(CH3COO)3- were derived from the titration data by regression analysis. Stability constants at infinite dilution (K(n)) and other relevant thermodynamic quantities were calculated for these three complexes. Logarithms for the formation constants of the general reaction Zn2+ + nCH3COO- = Zn(CH3COO)n2-n are n = 1-(1.9 +/- 0.2, 50-degrees-C), (2.3 +/- 0.1, 100-degrees-C), (2.8 +/- 0.1, 150-degrees-C), (3.5 +/- 0.1, 200-degrees-C), (4.3 +/- 0.2, 250-degrees-C), (5.3 +/- 0.3, 300-degrees-C); n = 2-(3.4 +/- 0.1, 50-degrees-C), (4.0 +/- 0.1, 100-degrees-C), (4.83 +/- 0.09, 150-degrees-C, (5.9 +/- 0.1, 200-degrees-C), (7.1 +/- 0.1, 250-degrees-C), (8.7 +/- 0.2, 300-degrees-C); n = 3-(4.1 +/- 0.3, 50-degrees-C), (4.7 +/- 0.3, 100-degrees-C), (5.5 +/- 0.3, 150-degrees-C), (6.6 +/- 0.3, 200-degrees-C), (7.9 +/- 0.3, 250-degrees-C), (9.4 +/- 0.3, 300-degrees-C). Calculations of zinc speciation in acetate-chloride solutions show that zinc acetate complexes should have an importance similar to zinc chloride complexes in high acetate waters where chloride to acetate molal ratios are less than about 10. C1 OAK RIDGE NATL LAB,DIV CHEM,OAK RIDGE,TN 37831. RP GIORDANO, TH (reprint author), NEW MEXICO STATE UNIV,DEPT EARTH SCI,BOX 3AB,LAS CRUCES,NM 88003, USA. NR 59 TC 32 Z9 33 U1 1 U2 9 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD, ENGLAND OX5 1GB SN 0016-7037 J9 GEOCHIM COSMOCHIM AC JI Geochim. Cosmochim. Acta PD SEP PY 1991 VL 55 IS 9 BP 2401 EP 2415 PG 15 WC Geochemistry & Geophysics SC Geochemistry & Geophysics GA GG443 UT WOS:A1991GG44300001 ER PT J AU MURRAY, RW TENBRINK, MRB BRUMSACK, HJ GERLACH, DC RUSS, GP AF MURRAY, RW TENBRINK, MRB BRUMSACK, HJ GERLACH, DC RUSS, GP TI RARE-EARTH ELEMENTS IN JAPAN SEA SEDIMENTS AND DIAGENETIC BEHAVIOR OF CE/CE-STAR - RESULTS FROM ODP LEG 127 SO GEOCHIMICA ET COSMOCHIMICA ACTA LA English DT Article ID GEOCHEMICAL STANDARDS; WATERS; OCEAN; MECHANISM; SEAWATER; SHALE; ROCKS AB The relative effects of paleoceanographic and paleogeographic variations, sediment lithology, and diagenetic processes on the recorded rare earth element (REE) chemistry of Japan Sea sediments are evaluated by investigating REE total abundances and relative fractionations in 59 samples from Ocean Drilling Program Leg 127. REE total abundances (SIGMA-REE) in the Japan Sea are strongly dependent upon the paleoceanographic position of a given site with respect to terrigenous and biogenic sources. REE concentrations at Site 794 (Yamato Basin) overall correspond well to aluminosilicate chemical indices and are strongly diluted by SiO2 within the late Miocene-Pliocene diatomaceous sequence. Eu/Eu* values at Site 794 reach a maximum through the diatomaceous interval as well, most likely suggesting an association of Eu/Eu* with the siliceous component, or reflecting slight incorporation of a detrital feldspar phase. SIGMA-REE at Site 795 (Japan Basin) also is affiliated strongly with aluminosilicate phases, yet is diluted only slightly by siliceous input. At Site 797 (Yamato Basin), SIGMA-REE is not as clearly associated with the aluminosilicate fraction, is correlated moderately to siliceous input, and may be sporadically influenced by detrital heavy minerals originating from the nearby rifted continental fragment composing the Yamato Rise. The biogenic influence is largest at Site 794, moderately developed at Site 797, and of only minor importance at Site 795, reflecting basinal contrasts in productivity such that the Yamato Basin records greater biogenic input than the Japan Basin, while the most productive waters overlie the easternmost sequence of Site 794. Ce/Ce* profiles at all three sites increase monotonically with depth, and record progressive diagenetic LREE fractionation. The observed Ce/Ce* record does not respond to changes in oxygenation state of the overlying water, and Ce/Ce* correlates slightly better with depth than with age. The downhole increase in Ce/Ce* at Site 794 and Site 797 is a passive response to diagenetic transfer of LREE (except Ce) from sediment to interstitial water. At Site 795, the overall lack of correlation between Ce/Ce* and La(n)/Yb(n) suggests that other processes are occurring which mask the diagenetic behavior of all LREEs. First-order calculations of the Ce budget in Japan Sea waters and sediment indicate that approximately 20% of the excess Ce adsorbed by settling particles is recycled within the water column, and that an additional approximately 38% is recycled at or near the seafloor (data from MASUZAWA and KOYAMA, 1989). Thus, because the remaining excess Ce is only approximately 10% of the total Ce, there is not a large source of Ce to the deeply buried sediment, further suggesting that the downhole increase in Ce/Ce* is a passive response to diagenetic behavior of the other LREEs. The REE chemistry of Japan Sea sediment therefore predicts successive downhole addition of LREEs to deeply-buried interstitial waters. C1 UNIV CALIF BERKELEY, DEPT GEOL & GEOPHYS, BERKELEY, CA 94720 USA. UNIV CALIF LAWRENCE LIVERMORE NATL LAB, DIV EARTH SCI, LIVERMORE, CA 94550 USA. GEOCHEM INST, W-3400 GOTTINGEN, GERMANY. UNIV CALIF LAWRENCE LIVERMORE NATL LAB, DIV NUCL CHEM, LIVERMORE, CA 94550 USA. RI Brumsack, Hans-Jurgen/O-7942-2016 OI Brumsack, Hans-Jurgen/0000-0002-5549-5018 NR 39 TC 70 Z9 90 U1 3 U2 11 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLAND SN 0016-7037 EI 1872-9533 J9 GEOCHIM COSMOCHIM AC JI Geochim. Cosmochim. Acta PD SEP PY 1991 VL 55 IS 9 BP 2453 EP 2466 DI 10.1016/0016-7037(91)90365-C PG 14 WC Geochemistry & Geophysics SC Geochemistry & Geophysics GA GG443 UT WOS:A1991GG44300004 ER PT J AU FRIDRICH, CJ SMITH, RP DEWITT, E MCKEE, EH AF FRIDRICH, CJ SMITH, RP DEWITT, E MCKEE, EH TI STRUCTURAL, ERUPTIVE, AND INTRUSIVE EVOLUTION OF THE GRIZZLY PEAK CALDERA, SAWATCH RANGE, COLORADO SO GEOLOGICAL SOCIETY OF AMERICA BULLETIN LA English DT Article ID MAGMA CHAMBER; MOUNTAINS; BRECCIAS; LAYERS; TUFF; SR; PB AB Volcanic and shallow intrusive features of the deeply dissected 34 Ma Grizzly Peak caldera in west-central Colorado record evolution of the magmatic center from pre-caldera through post-resurgent stages. Pre-caldera dikes, zones of hydrothermally altered rocks, and lava flows formed along a circular swarm of cone-sheet fractures around the site of the future caldera. Early, largely rhyolitic upper-crustal magmatism culminated in the caldera-forming eruption of the Grizzly Peak Tuff. Intracaldera tuff is zoned from high-silica rhyolite at the base to low-silica rhyolite at the eroded top and, further, contains dacite to mafic latite pumice lumps in two heterogeneous tuff layers in the upper third of the preserved section. Half of the erupted tuff ponded in the 17-by 23-km, > 600-km3 caldera, filling the asymmetric depression to a compacted thickness locally > 2.7 km, including intercalated rock-avalanche megabreccias shed from ring-fault scarps. The asymmetric caldera has an inner ring-fracture zone that separates two structural segments that collapsed to different depths. Caldera fill buried collapse structures as they formed; the inner ring-fracture zone is a growth (or syn-depositional) fault in the single-cooling-unit tuff. Welded-tuff ring dikes are locally exposed at erosion levels below the caldera fill. These dikes are remanants of fissure vents in the outer ring-fracture zone. Following collapse, the Grizzly Peak caldera was uplifted, forming a complexly faulted resurgent dome. Resurgence resulted partly from emplacement of a composite granodiorite laccolith now exposed in the eroded core of the dome. A belt of mafic latite to rhyolite porphyry dikes and small stocks formed across the center of the domed caldera during the waning of the magmatic center. Latite intrusions in this suite represent the penetration of relatively mafic magma to the surface following solidification of the felsic subcaldera batholith. C1 STANFORD UNIV,DEPT GEOL,STANFORD,CA 94305. EG&G IDAHO INC,IDAHO NATL ENGN LAB,IDAHO FALLS,ID 83415. US GEOL SURVEY,DENVER FED CTR,DENVER,CO 80225. US GEOL SURVEY,MENLO PK,CA 94025. NR 45 TC 49 Z9 50 U1 0 U2 0 PU GEOLOGICAL SOC AMERICA PI BOULDER PA PO BOX 9140 3300 PENROSE PLACE, BOULDER, CO 80301 SN 0016-7606 J9 GEOL SOC AM BULL JI Geol. Soc. Am. Bull. PD SEP PY 1991 VL 103 IS 9 BP 1160 EP 1177 DI 10.1130/0016-7606(1991)103<1160:SEAIEO>2.3.CO;2 PG 18 WC Geosciences, Multidisciplinary SC Geology GA GF121 UT WOS:A1991GF12100003 ER PT J AU RENEAU, SL RAYMOND, R AF RENEAU, SL RAYMOND, R TI CATION-RATIO DATING OF ROCK VARNISH - WHY DOES IT WORK SO GEOLOGY LA English DT Article ID DESERT VARNISH AB Cation-ratio dating of rock varnish is an empirical surface-exposure dating method based on decreases in the cation ratio (Ca+K):Ti over time. Although these changes were attributed to the preferential leaching of Ca and K from varnish, the existence of such leaching has not been demonstrated. In varnish collected from the Cima volcanic field, California, distributions of the minor elements used in cation-ratio (CR) dating reflect varnish stratigraphy as defined by the major elements Mn, Fe, and Si. In general, K is associated with Si, Ca with Mn, and Ti with Fe. Because of these associations, variations in CRs both within samples and between samples typically reflect variations in major element composition associated with varnish stratigraphy. No systematic changes with depth or age are present in the ratios K:Si or Ca:Mn as would be expected if K and Ca have been preferentially leached from varnish. Available data suggest that, instead of a leaching process, thickness-dependent changes in the amount of substrate being incorporated into varnish analyses contribute to the empirical trend of decreasing CR with increasing surface age, although further research is required to verify this hypothesis. RP RENEAU, SL (reprint author), UNIV CALIF LOS ALAMOS SCI LAB,DIV EARTH & ENVIRONM SCI,MS D462,LOS ALAMOS,NM 87545, USA. NR 17 TC 20 Z9 20 U1 0 U2 1 PU GEOLOGICAL SOC AMERICA PI BOULDER PA PO BOX 9140 3300 PENROSE PLACE, BOULDER, CO 80301 SN 0091-7613 J9 GEOLOGY JI Geology PD SEP PY 1991 VL 19 IS 9 BP 937 EP 940 DI 10.1130/0091-7613(1991)019<0937:CRDORV>2.3.CO;2 PG 4 WC Geology SC Geology GA GF115 UT WOS:A1991GF11500018 ER PT J AU WENDLANDT, RF BALDRIDGE, WS NEUMANN, ER AF WENDLANDT, RF BALDRIDGE, WS NEUMANN, ER TI MODIFICATION OF LOWER CRUST BY CONTINENTAL RIFT MAGMATISM SO GEOPHYSICAL RESEARCH LETTERS LA English DT Article ID RIO-GRANDE RIFT; MANTLE BOUNDARY AB We document a systematic inverse relationship between the volume of erupted volcanic rocks associated with continental rifts and the seismic compressional wave velocity contrast across the Mobo. This relationship is interpreted as evidence that magmatism significantly modifies the composition(s) of the lower crust (and upper mantle) during rifting processes. The relationship is not influenced by the current thermal state of the lithosphere, being observed for both modern rifts (Rio Grande, Kenya, Rhine) and paleorifts (Oslo), and may also characterize continental flood basalt provinces (Columbia River and Snake River plain). The trend is reconciled by igneous and metamorphic processes that collectively modify the lower crust to more mafic bulk compositions, resulting in higher compressional velocities, and that decrease the density of the residual mantle, resulting in lower compressional velocities. These results support the view that most mantle-derived magma in continental rift settings is trapped in the crust. C1 UNIV CALIF LOS ALAMOS SCI LAB,LOS ALAMOS,NM 87545. UNIV OSLO,MINERAL GEOL MUSEUM,N-0562 OSLO 5,NORWAY. RP WENDLANDT, RF (reprint author), COLORADO SCH MINES,DEPT GEOL & GEOL ENGN,GOLDEN,CO 80401, USA. NR 35 TC 6 Z9 7 U1 1 U2 4 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 SN 0094-8276 J9 GEOPHYS RES LETT JI Geophys. Res. Lett. PD SEP PY 1991 VL 18 IS 9 BP 1759 EP 1762 DI 10.1029/91GL01881 PG 4 WC Geosciences, Multidisciplinary SC Geology GA GF593 UT WOS:A1991GF59300027 ER PT J AU MACCRACKEN, MC AF MACCRACKEN, MC TI CARBON-DIOXIDE AND THE FATE OF EARTH - COMMENT SO GLOBAL ENVIRONMENTAL CHANGE-HUMAN AND POLICY DIMENSIONS LA English DT Editorial Material RP MACCRACKEN, MC (reprint author), UNIV CALIF LAWRENCE LIVERMORE NATL LAB,LIVERMORE,CA 94550, USA. NR 0 TC 1 Z9 1 U1 0 U2 0 PU BUTTERWORTH-HEINEMANN LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD, OXON, ENGLAND OX5 1GB SN 0959-3780 J9 GLOBAL ENVIRON CHANG JI Glob. Environ. Change - Human Policy Dimens. PD SEP PY 1991 VL 1 IS 4 BP 266 EP 267 DI 10.1016/0959-3780(91)90053-V PG 2 WC Environmental Sciences; Environmental Studies; Geography SC Environmental Sciences & Ecology; Geography GA GK293 UT WOS:A1991GK29300001 ER PT J AU DORGARTEN, HW TSANG, CF AF DORGARTEN, HW TSANG, CF TI MODELING THE DENSITY-DRIVEN MOVEMENT OF LIQUID WASTES IN DEEP SLOPING AQUIFERS SO GROUND WATER LA English DT Article ID UNSATURATED ZONE; TRANSPORT AB One method for the disposal of hazardous liquid wastes is by injection into deep aquifers. Although these aquifers may be separated from underground sources of drinking water by thick formations of low permeability, their mobility due to different migration mechanisms has to be studied carefully, since the injected wastes remain toxic over periods of thousands of years. One possible mechanism for waste movement is density-driven flow and transport, due to density differences between the waste and the surrounding water in the injection zone. In the present paper the importance of this phenomenon is studied mathematically by means of analytical and numerical calculations for typical deep injection conditions. The analytical estimates reveal that density-driven movement of liquid wastes in sloping aquifers can be much stronger than plume migration due to natural hydraulic gradients. This finding is emphasized by the results of a two-dimensional vertical finite element model, which is applied for detailed numerical simulations. Results show that during the initial stage, waste can be expected to spread into all directions due to density-induced stratification effects. Later on, it mainly moves laterally along the slope of either aquifer top or aquifer bottom, depending on the waste density. If regional ground-water flow is directed the same way, transport is accelerated. If regional ground-water flow is in the opposite direction, on the other hand, transport to both sides must be expected to occur. Thus, the aquifer slope and regional hydraulic gradient may be equally significant factors in estimating potential migration of disposed liquid wastes. C1 UNIV CALIF BERKELEY LAWRENCE BERKELEY LAB,DIV EARTH SCI,BERKELEY,CA 94720. RP DORGARTEN, HW (reprint author), HOCHTIEF AG,TECH ABT TIEFBAU,RELLINGHAUSER STR 53-57,W-4300 ESSEN 1,GERMANY. NR 15 TC 18 Z9 19 U1 0 U2 5 PU GROUND WATER PUBLISHING CO PI COLUMBUS PA 2600 GROUND WATER WAY, COLUMBUS, OH 43219 SN 0017-467X J9 GROUND WATER JI Ground Water PD SEP-OCT PY 1991 VL 29 IS 5 BP 655 EP 662 DI 10.1111/j.1745-6584.1991.tb00556.x PG 8 WC Geosciences, Multidisciplinary; Water Resources SC Geology; Water Resources GA GD509 UT WOS:A1991GD50900003 ER PT J AU AGGARWAL, PK AF AGGARWAL, PK TI COMPUTER MODELING OF SCALE FORMATION DURING TREATMENT OF GROUND-WATER IN AIR STRIPPERS - DISCUSSION SO GROUND WATER MONITORING AND REMEDIATION LA English DT Letter RP AGGARWAL, PK (reprint author), ARGONNE NATL LAB,9700 S CASS AVE,ARGONNE,IL 60439, USA. RI aggarwal, pradeep/C-8367-2016 OI aggarwal, pradeep/0000-0001-5970-1408 NR 0 TC 1 Z9 1 U1 0 U2 1 PU GROUND WATER PUBLISHING CO PI COLUMBUS PA 2600 GROUND WATER WAY, COLUMBUS, OH 43219 SN 1069-3629 J9 GROUND WATER MONIT R JI Ground Water Monit. Remediat. PD FAL PY 1991 VL 11 IS 4 BP 165 EP 165 DI 10.1111/j.1745-6592.1991.tb00403.x PG 1 WC Water Resources SC Water Resources GA GL553 UT WOS:A1991GL55300010 ER PT J AU DOSSKEY, MG ADRIANO, DC MURPHY, CE COREY, JC AF DOSSKEY, MG ADRIANO, DC MURPHY, CE COREY, JC TI EFFECTIVENESS OF A SLOW-RELEASE HERBICIDE SYSTEM FOR CONTROL OF ROOT INTRUSIONS INTO BURIED HAZARDOUS-WASTE SO HAZARDOUS WASTE & HAZARDOUS MATERIALS LA English DT Article AB A slow-release herbicide system was tested for its ability to act as a barrier to plant root growth into buried hazardous waste. A layer of trifluralin-releasing pellets, bonded to polypropylene fabric, was placed between topsoil and gravel drainage layer in 100 and 200 liter containers planted in bahiagrass, bamboo, or loblolly pine. After 3 years, sampling has revealed almost no growth of roots below the treated fabric. However, roots have grown closer to the barrier than expected, and rhizomes appear less affected than roots. The extent to which elevated soil temperatures in this study influenced effectiveness is uncertain, although longevity is likely to be reduced. Adequate soil depth over the fabric is important for good health of the cover vegetation. RP DOSSKEY, MG (reprint author), UNIV GEORGIA,SAVANNAH RIVER ECOL LAB,DRAWER E,AIKEN,SC 29802, USA. NR 0 TC 5 Z9 5 U1 0 U2 1 PU MARY ANN LIEBERT INC PUBL PI LARCHMONT PA 2 MADISON AVENUE, LARCHMONT, NY 10538 SN 0882-5696 J9 HAZARD WASTE HAZARD JI Hazard. Waste Hazard. Mater. PD FAL PY 1991 VL 8 IS 4 BP 293 EP 301 DI 10.1089/hwm.1991.8.293 PG 9 WC Engineering, Environmental; Environmental Sciences SC Engineering; Environmental Sciences & Ecology GA GV607 UT WOS:A1991GV60700002 ER PT J AU MERWIN, SE DARWIN, RF AF MERWIN, SE DARWIN, RF TI DETERMINING OPTIMAL PROTECTIVE ACTIONS FOR NUCLEAR INCIDENTS SO HEALTH PHYSICS LA English DT Article ID LIFE; RISK; ACCIDENT; HEALTH AB The U.S. Environmental Protection Agency is revising its Protective Action Guides (PAGs), which specify recommended dose levels at which actions should be taken to protect the public during an accident at a nuclear facility. The appropriateness of these PAGs depends on the health risks that could be avoided by the protective actions relative to both the costs and adverse health impacts of taking the actions. According to the optimization principle of radiation protection, the cost of measures designed to protect people from ionizing radiation should be commensurate with the risks avoided. This article evaluates the recommended protective actions with respect to the optimization principle. The evaluation is based on both recent radiation risk estimates and a derivation of the monetary value of a reduction in risk. It is estimated that evacuation of a population sector should be carried out only if the evacuation will reduce the collective dose equivalent to the population by 1 person-Sv or more for every U.S. $34,000 to $250,000 in net evacuation costs. Therefore, the decision to evacuate should be based on the dose that would be avoided by the evacuation and predetermined site-specific evacuation costs, rather than simply projected dose to the population. Findings further suggest that separate PAGs for the thyroid and skin are unnecessary for protecting against stochastic effects because use of the effective dose equivalent concept eliminates the need for these guides. Separate PAGs for specific organs need only ensure that significant nonstochastic effects are prevented. C1 PACIFIC NW LAB, RICHLAND, WA 99352 USA. NR 44 TC 2 Z9 2 U1 0 U2 0 PU LIPPINCOTT WILLIAMS & WILKINS PI PHILADELPHIA PA 530 WALNUT ST, PHILADELPHIA, PA 19106-3621 USA SN 0017-9078 EI 1538-5159 J9 HEALTH PHYS JI Health Phys. PD SEP PY 1991 VL 61 IS 3 BP 305 EP 316 DI 10.1097/00004032-199109000-00001 PG 12 WC Environmental Sciences; Public, Environmental & Occupational Health; Nuclear Science & Technology; Radiology, Nuclear Medicine & Medical Imaging SC Environmental Sciences & Ecology; Public, Environmental & Occupational Health; Nuclear Science & Technology; Radiology, Nuclear Medicine & Medical Imaging GA GD979 UT WOS:A1991GD97900001 PM 1880021 ER PT J AU SEED, TM KRETZ, ND SCHLENKER, RA AF SEED, TM KRETZ, ND SCHLENKER, RA TI RADON EXPOSURE SYSTEM FOR MAMMALIAN-CELLS IN CULTURE - DESIGN, OPERATION, AND DOSIMETRY SO HEALTH PHYSICS LA English DT Article ID ALPHA-PARTICLES; DNA DAMAGE; REPAIR; TRANSFORMATION; INDUCTION; NEUTRONS; 10T1/2; PU-238 AB A novel system for Rn gas exposure of mammalian cells in culture has been designed, constructed, and used to directly assess both the magnitude and the nature of chronic, low-dose Rn/Rn daughter toxicity of exposed vital lung cells isolated from normal pulmonary tissue, propagated and exposed in vitro. Direct correlations between atmospheric Rn concentrations, alpha-particle fluences, and macro- and microdoses of absorbed radiation doses by lung cells provide for a heretofore unavailable assessment of critical doses to vital cells. RP SEED, TM (reprint author), ARGONNE NATL LAB, DIV BIOL & MED RES, RADIAT HEMATOL GRP, ARGONNE, IL 60439 USA. NR 23 TC 4 Z9 4 U1 1 U2 2 PU LIPPINCOTT WILLIAMS & WILKINS PI PHILADELPHIA PA 530 WALNUT ST, PHILADELPHIA, PA 19106-3621 USA SN 0017-9078 EI 1538-5159 J9 HEALTH PHYS JI Health Phys. PD SEP PY 1991 VL 61 IS 3 BP 349 EP 357 DI 10.1097/00004032-199109000-00004 PG 9 WC Environmental Sciences; Public, Environmental & Occupational Health; Nuclear Science & Technology; Radiology, Nuclear Medicine & Medical Imaging SC Environmental Sciences & Ecology; Public, Environmental & Occupational Health; Nuclear Science & Technology; Radiology, Nuclear Medicine & Medical Imaging GA GD979 UT WOS:A1991GD97900004 PM 1652575 ER PT J AU MARTZ, DE ROOD, AS GEORGE, JL PEARSON, MD LANGNER, GH AF MARTZ, DE ROOD, AS GEORGE, JL PEARSON, MD LANGNER, GH TI YEAR-TO-YEAR VARIATIONS IN ANNUAL AVERAGE INDOOR 222RN CONCENTRATIONS SO HEALTH PHYSICS LA English DT Note AB Annual average indoor Rn-222 concentrations in 40 residences in and around Grand Junction, CO, have been measured repeatedly since 1984 using commercial alpha-track monitors (ATM) deployed for successive 12-mo time periods. Data obtained provide a quantitative measure of the year-to-year variations in the annual average Rn concentrations in these structures over this 6-y period. A mean coefficient of variation of 25% was observed for the year-to-year variability of the measurements at 25 sampling stations for which complete data were available. Individual coefficients of variation at the various stations ranged from a low of 7.7% to a high of 51%. The observed mean coefficient of variation includes contributions due to the variability in detector response as well as the true year-to-year variation in the annual average Rn concentrations. Factoring out the contributions from the measured variability in the response of the detectors used, the actual year-to-year variability of the annual average Rn concentrations was approximately 22%. RP MARTZ, DE (reprint author), CHEM NUCL GEOTECH INC, US DOE, GRAND JUNCT PROJECTS OFF, POB 14000, GRAND JUNCTION, CO 81502 USA. NR 8 TC 14 Z9 14 U1 0 U2 0 PU LIPPINCOTT WILLIAMS & WILKINS PI PHILADELPHIA PA 530 WALNUT ST, PHILADELPHIA, PA 19106-3621 USA SN 0017-9078 EI 1538-5159 J9 HEALTH PHYS JI Health Phys. PD SEP PY 1991 VL 61 IS 3 BP 409 EP 413 DI 10.1097/00004032-199109000-00012 PG 5 WC Environmental Sciences; Public, Environmental & Occupational Health; Nuclear Science & Technology; Radiology, Nuclear Medicine & Medical Imaging SC Environmental Sciences & Ecology; Public, Environmental & Occupational Health; Nuclear Science & Technology; Radiology, Nuclear Medicine & Medical Imaging GA GD979 UT WOS:A1991GD97900012 PM 1880029 ER PT J AU STABIN, M SCHLAFKESTELSON, A AF STABIN, M SCHLAFKESTELSON, A TI A LIST OF NUCLEAR-MEDICINE RADIONUCLIDES AND POTENTIAL CONTAMINANTS FOR OPERATORS OF INVIVO COUNTERS SO HEALTH PHYSICS LA English DT Article AB Operators of in-vivo counters often encounter unusual photopeaks, some of which may be attributed to nuclear medicine radiopharmaceuticals recently received by the subject. This article lists the most common radio-pharmaceuticals used in nuclear medicine, their common uses, their half-lives and principal decay energies, and the half-lives and decay energies of any contaminants or daughter products they may contain. The purpose is to help the in-vivo counter operator track down and eliminate causes of such unusual photopeaks. RP STABIN, M (reprint author), OAK RIDGE ASSOCIATED UNIV, CTR RADIOPHARMACEUT INTERNAL DOSE INFORMAT, POB 117, OAK RIDGE, TN 37831 USA. FU NIDDK NIH HHS [DK 38842-04] NR 3 TC 4 Z9 4 U1 0 U2 0 PU LIPPINCOTT WILLIAMS & WILKINS PI PHILADELPHIA PA 530 WALNUT ST, PHILADELPHIA, PA 19106-3621 USA SN 0017-9078 EI 1538-5159 J9 HEALTH PHYS JI Health Phys. PD SEP PY 1991 VL 61 IS 3 BP 427 EP 430 DI 10.1097/00004032-199109000-00015 PG 4 WC Environmental Sciences; Public, Environmental & Occupational Health; Nuclear Science & Technology; Radiology, Nuclear Medicine & Medical Imaging SC Environmental Sciences & Ecology; Public, Environmental & Occupational Health; Nuclear Science & Technology; Radiology, Nuclear Medicine & Medical Imaging GA GD979 UT WOS:A1991GD97900015 PM 1880031 ER PT J AU SEIGEL, RA FORD, NB AF SEIGEL, RA FORD, NB TI PHENOTYPIC PLASTICITY IN THE REPRODUCTIVE CHARACTERISTICS OF AN OVIPAROUS SNAKE, ELAPHE-GUTTATA - IMPLICATIONS FOR LIFE-HISTORY STUDIES SO HERPETOLOGICA LA English DT Article DE SERPENTES; SQUAMATA; ELAPHE; REPRODUCTION; PHENOTYPIC PLASTICITY; LIFE-HISTORY EVOLUTION; CLUTCH SIZE ID FOOD AVAILABILITY; PATTERNS; ENVIRONMENT; REPTILES; TURTLES; LIZARD; TRAITS; SIZE AB Previous field studies of squamate reptiles have shown that many life history traits show a significant amount of phenotypic plasticity, especially in response to prey availability. These results were recently supported by laboratory studies on a viviparous garter snake, which showed that clutch size and clutch mass were plastic in response to changes in energy intake, but that relative clutch mass and offspring size were relatively canalized. To determine if these results extend to oviparous reptiles, we conducted an experimental study of phenotypic plasticity in the corn snake, Elaphe guttata. Female corn snakes on a high energy diet produced larger clutch sizes, larger clutch masses, and larger relative clutch masses than did females on a low energy diet, but egg mass did not differ between the feeding regimens. Our data support earlier studies suggesting that much of the observed intraspecific variation in life-history traits of squamate reptiles may be the result of phenotypic plasticity. C1 SAVANNAH RIVER ECOL LAB,AIKEN,SC 29802. NR 27 TC 75 Z9 77 U1 2 U2 8 PU HERPETOLOGISTS LEAGUE PI JOHNSON CITY PA EAST TENNESSEE STATE UNIV, DEPT BIOLOGICAL SCIENCES, BOX 70726, JOHNSON CITY, TN 37614-0726 SN 0018-0831 J9 HERPETOLOGICA JI Herpetologica PD SEP PY 1991 VL 47 IS 3 BP 301 EP 307 PG 7 WC Zoology SC Zoology GA GK951 UT WOS:A1991GK95100004 ER PT J AU WULLSCHLEGER, SD OOSTERHUIS, DM AF WULLSCHLEGER, SD OOSTERHUIS, DM TI OSMOTIC ADJUSTMENT AND THE GROWTH-RESPONSE OF 7 VEGETABLE CROPS FOLLOWING WATER-DEFICIT STRESS SO HORTSCIENCE LA English DT Article DE ABELMOSCHUS-ESCULENTUS; BETA-VULGARIS; CAPSICUM-ANNUUM; DROUGHT TOLERANCE; LEAF GROWTH; LYCOPERSICON-ESCULENTUM; OSMOTIC POTENTIAL; PHASEOLUS-VULGARIS; PISUM-SATIVUM; SORGHUM-BICOLOR; SPINACIA-OLERACEA ID SORGHUM GENOTYPES; CABBAGE LEAVES; OSMOREGULATION; ADAPTATION; TOLERANCE; FIELD AB Growth-chamber studies were conducted to examine the ability of seven vegetable crops-'Blue Lake' bean (Phaseolus vulgaris L.), 'Detroit Dark Red' beet (Beta vulgaris L.), 'Burgundy' okra (Abelmoschus esculentus (Moench), 'Little Marvel' pea (Pisum sativum L.), 'California Wonder' bell pepper (Capsicum annuum L.), 'New Zealand' spinach (Spinacia oleracea L.), and 'Beefsteak' tomato (Lycopersicon esculentum Mill.)-to adjust osmotically in response to water-deficit stress. Water stress was imposed by withholding water for 3 days, and the adjustment of leaf and root osmotic potentials upon relief of the stress and rehydration were monitored with thermocouple psychrometers. Despite similar reductions in leaf water potential and stomatal conductance among the species studied, crop-specific differences were observed in leaf and root osmotic adjustment. Leaf osmotic adjustment were observed for bean, pepper, and tomato following water-deficit stress. Root osmotic adjustment was significant in bean, okra, pea, and tomato. Furthermore, differences in leaf and root osmotic adjustment were also observed among five tomato cultivars. Leaf osmotic adjustment was not associated with the maintenance of leaf growth following water-deficit stress, since leaf expansion of water-stressed bean and pepper, two species capable of osmotic adjustment, was similar to that of spinach, which exhibited no leaf osmotic adjustment. C1 UNIV ARKANSAS,DEPT AGRON,ALTHEIMER LAB,FAYETTEVILLE,AR 72701. RP WULLSCHLEGER, SD (reprint author), OAK RIDGE NATL LAB,DIV ENVIRONM SCI,POB 2008,OAK RIDGE,TN 37831, USA. RI Wullschleger, Stan/B-8297-2012 OI Wullschleger, Stan/0000-0002-9869-0446 NR 22 TC 10 Z9 10 U1 1 U2 7 PU AMER SOC HORTICULTURAL SCIENCE PI ALEXANDRIA PA 701 NORTH SAINT ASAPH STREET, ALEXANDRIA, VA 22314-1998 SN 0018-5345 J9 HORTSCIENCE JI Hortscience PD SEP PY 1991 VL 26 IS 9 BP 1210 EP 1212 PG 3 WC Horticulture SC Agriculture GA GH450 UT WOS:A1991GH45000040 ER PT J AU MORENO, MA SCHUBERT, G BAUMGARDNER, J KIVELSON, MG PAIGE, DA AF MORENO, MA SCHUBERT, G BAUMGARDNER, J KIVELSON, MG PAIGE, DA TI IOS VOLCANIC AND SUBLIMATION ATMOSPHERES SO ICARUS LA English DT Article ID SO2 ATMOSPHERE; PLASMA TORUS; FLOW; METEOROLOGY; IONOSPHERE; ABUNDANCE; SPECTRUM; PRESSURE; SULFUR; OXYGEN C1 UNIV CALIF LOS ANGELES,GEOPHYS & PLANETARY PHYS,LOS ANGELES,CA 90024. UNIV CALIF LOS ANGELES,DEPT EARTH & SPACE SCI,LOS ANGELES,CA 90024. UNIV CALIF LOS ALAMOS SCI LAB,LOS ALAMOS,NM 87545. RP MORENO, MA (reprint author), EVALCOMP CORP,LOS ANGELES,CA 90025, USA. RI Kivelson, Margaret/I-9019-2012 OI Kivelson, Margaret/0000-0003-3859-8581 NR 48 TC 43 Z9 43 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 0019-1035 J9 ICARUS JI Icarus PD SEP PY 1991 VL 93 IS 1 BP 63 EP 81 DI 10.1016/0019-1035(91)90164-O PG 19 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA GE545 UT WOS:A1991GE54500005 ER PT J AU EIMERL, D AF EIMERL, D TI ULTRATHIN HARMONIC GENERATORS SO IEEE JOURNAL OF QUANTUM ELECTRONICS LA English DT Article ID OPTICAL-WAVE BREAKING; FIBERS; PULSES AB In second-harmonic generation in optical materials with extremely large nonlinearity (about 1000 that in KDP), efficient conversion may be expected for gain lengths of just a few micrometers. If the gain length is less than the coherence length, the phase-matching condition normally invoked for KDP and other common nonlinear materials may not apply. Devices based on such ultrathin media are potentially insensitive to wavelength, bandwidth, temperature, and poor beam quality. We have analyzed harmonic generation in ultrathin media to evaluate their materials requirements. We show that in such devices the conversion efficiency to the second harmonic is necessarily limited to about 25%, because higher harmonics are also necessarily generated with significant efficiencies. Ultrathin devices are therefore subject to large thermal loads, and perhaps optical damage arising from the generation of strong ultraviolet or soft X-ray harmonics. Whereas ultrathin media are not as efficient as conventional phase-matched crystals for second-harmonic generation, they do generate phase-coherent, multiple higher harmonics. As a consequence, they can generate optical square waves, electromagnetic shock waves, and may find application as coherent soft X-ray generators. RP EIMERL, D (reprint author), UNIV CALIF LAWRENCE LIVERMORE NATL LAB,NONLINEAR OPT MAT GRP,LIVERMORE,CA 94550, USA. NR 6 TC 0 Z9 0 U1 0 U2 3 PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017-2394 SN 0018-9197 J9 IEEE J QUANTUM ELECT JI IEEE J. Quantum Electron. PD SEP PY 1991 VL 27 IS 9 BP 2170 EP 2181 DI 10.1109/3.135176 PG 12 WC Engineering, Electrical & Electronic; Optics; Physics, Applied SC Engineering; Optics; Physics GA GJ183 UT WOS:A1991GJ18300013 ER PT J AU VELSKO, SP WEBB, M DAVIS, L HUANG, C AF VELSKO, SP WEBB, M DAVIS, L HUANG, C TI PHASE-MATCHED HARMONIC-GENERATION IN LITHIUM TRIBORATE (LBO) SO IEEE JOURNAL OF QUANTUM ELECTRONICS LA English DT Article ID 2ND-HARMONIC GENERATION; LIB3O5; CRYSTALS AB We present refractive index, thermo-optic, phase-matching angle, nonlinear coefficient, absorption, and scattering data on lithium triborate (LBO) crystals. The calculated angles for phase matching in the low birefringence y-z plane are in better agreement with direct measurements than previous reported values. The nonlinear coefficient measurements imply that d32 = 0.84 +/- 0.06 pm/V and d15 = 0.71 +/- 0.05 pm/V for frequency doubling of 1.064-mu-m. The calculated thermal sensitivity parameters for phase matching are in poor agreement with reported experimental values. It is shown that Type II doubling and third-harmonic generation of Nd:YAG harmonics can be significantly more efficient than Type I, but requires longer crystals or a more tightly focussed beam. C1 STATE ADM BLDG MAT,SYNTHET CRYSTALS RES INST,BEIJING,PEOPLES R CHINA. RP VELSKO, SP (reprint author), UNIV CALIF LAWRENCE LIVERMORE NATL LAB,LIVERMORE,CA 94550, USA. NR 26 TC 107 Z9 107 U1 3 U2 24 PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017-2394 SN 0018-9197 J9 IEEE J QUANTUM ELECT JI IEEE J. Quantum Electron. PD SEP PY 1991 VL 27 IS 9 BP 2182 EP 2192 DI 10.1109/3.135177 PG 11 WC Engineering, Electrical & Electronic; Optics; Physics, Applied SC Engineering; Optics; Physics GA GJ183 UT WOS:A1991GJ18300014 ER PT J AU OLBRIGHT, GR BRYAN, RP FU, WS APTE, R BLOOM, DM LEE, YH AF OLBRIGHT, GR BRYAN, RP FU, WS APTE, R BLOOM, DM LEE, YH TI LINEWIDTH, TUNABILITY, AND VHF-MILLIMETER WAVE FREQUENCY-SYNTHESIS OF VERTICAL-CAVITY GAAS QUANTUM-WELL SURFACE-EMITTING LASER DIODE-ARRAYS SO IEEE PHOTONICS TECHNOLOGY LETTERS LA English DT Article AB We report the measurement of the laser linewidth, wavelength tunability, and the generation of microwave frequencies between individually addressable elements of a vertical-cavity GaAs quantum-well surface-emitting laser diode array (lasing in the wavelength range 850-865 nm). Using heterodyne techniques, we obtain a deconvolved 65 MHz laser linewidth from the 109 MHz beat signal. The laser linewidth corresponds to a semiconductor laser linewidth enhancement factor alpha = 5.7 which is in excellent agreement to that obtained independently from optical gain measurements and corresponding calculated refractive index changes. We measured heterodyne beat frequencies of 2-20 GHz. (The bandwidth was limited by our microwave amplifiers.) A simple calculation shows that a tuning range of 65 MHz-to-3 THz can be achieved. C1 SANDIA NATL LABS,ALBUQUERQUE,NM 87185. STANFORD UNIV,SOLID STATE ELECTR LAB,STANFORD,CA 94305. STANFORD UNIV,GINZTON LAB,STANFORD,CA 94305. KOREA ADV INST SCI & TECHNOL,DEPT PHYS,DACJON,SOUTH KOREA. RP OLBRIGHT, GR (reprint author), PHOTON RES INC,BROOMFIELD,CO 80021, USA. RI Lee, Yong Hee/C-2015-2011 NR 15 TC 10 Z9 10 U1 0 U2 2 PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017-2394 SN 1041-1135 J9 IEEE PHOTONIC TECH L JI IEEE Photonics Technol. Lett. PD SEP PY 1991 VL 3 IS 9 BP 779 EP 781 DI 10.1109/68.84490 PG 3 WC Engineering, Electrical & Electronic; Optics; Physics, Applied SC Engineering; Optics; Physics GA GD088 UT WOS:A1991GD08800003 ER PT J AU HEATH, MT ETHERIDGE, JA AF HEATH, MT ETHERIDGE, JA TI VISUALIZING THE PERFORMANCE OF PARALLEL PROGRAMS SO IEEE SOFTWARE LA English DT Article C1 OAK RIDGE NATL LAB,MATH SCI SECT,OAK RIDGE,TN 37831. RP HEATH, MT (reprint author), UNIV ILLINOIS,NATL CTR SUPERCOMP APPL,4157 BECKMAN INST,405 MATHEWS AVE,URBANA,IL 61801, USA. NR 9 TC 135 Z9 138 U1 0 U2 0 PU IEEE COMPUTER SOC PI LOS ALAMITOS PA 10662 LOS VAQUEROS CIRCLE, PO BOX 3014, LOS ALAMITOS, CA 90720-1264 SN 0740-7459 J9 IEEE SOFTWARE JI IEEE Softw. PD SEP PY 1991 VL 8 IS 5 BP 29 EP 39 DI 10.1109/52.84214 PG 11 WC Computer Science, Software Engineering SC Computer Science GA GD057 UT WOS:A1991GD05700008 ER PT J AU YEE, JH MAYHALL, DJ SIEGER, GE ALVAREZ, RA AF YEE, JH MAYHALL, DJ SIEGER, GE ALVAREZ, RA TI PROPAGATION OF INTENSE MICROWAVE PULSES IN AIR AND IN A WAVE-GUIDE SO IEEE TRANSACTIONS ON ANTENNAS AND PROPAGATION LA English DT Review ID IONIZATION; ATMOSPHERE AB In this mini-review, some results obtained from recent investigations of the propagation of intense electromagnetic pulses in the atmosphere and in an air-filled waveguide when the field strength is above the threshold for air breakdown are presented. It is shown how the air breakdown affects the shape of the pulse. In addition, the accuracy of our calculational models is discussed comparing calculations with experimental data. RP YEE, JH (reprint author), UNIV CALIF LAWRENCE LIVERMORE NATL LAB,POB 808,MAIL CODE L-156,LIVERMORE,CA 94551, USA. NR 23 TC 11 Z9 13 U1 1 U2 4 PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017-2394 SN 0018-926X J9 IEEE T ANTENN PROPAG JI IEEE Trans. Antennas Propag. PD SEP PY 1991 VL 39 IS 9 BP 1421 EP 1427 DI 10.1109/8.99053 PG 7 WC Engineering, Electrical & Electronic; Telecommunications SC Engineering; Telecommunications GA GL904 UT WOS:A1991GL90400020 ER PT J AU MILLER, DP AF MILLER, DP TI FUSION - A PLAN FOR DEVELOPING A FAMILIAR USER SYSTEM INTERFACE FOR THE IC FABRICATION INDUSTRY SO IEEE TRANSACTIONS ON COMPONENTS HYBRIDS AND MANUFACTURING TECHNOLOGY LA English DT Article AB In spite of the best efforts of designers and the power of today's computer workstations, many user system interfaces (USI's) found in IC fabrication equipment are not very user friendly. Hence, for many complex IC fabrication machines, extensive training programs, thick user manuals, and operator confusion have become a way of life. Since many users must interact with several machines or several types of machines, interequipment inefficiencies arise due to negative transfer of training. This paper discusses the concept of developing a set of industry guidelines for a familiar USI for IC fabrication equipment called Familiar User System Interface OperatioN (FUSION). A familiar USI across the industry would allow process engineers, operators, and service technicians to learn only one set of interface conventions. Successful standardization would lead to reduced training time and operational errors, faster recipe editing, more rapid fault diagnosis and repair, and reduced personnel specialization. This paper addresses the need and potential benefits of FUSION, identifies some of the major technical challenges to developing such an interface, and proposes a developmental approach that would systematically create, test, and validate candidate designs. The author hopes that this paper will also stimulate spirited discussion of the FUSION concept within the industry. RP MILLER, DP (reprint author), SANDIA NATL LABS,HUMAN FACTORS GRP,ALBUQUERQUE,NM 87185, USA. NR 8 TC 0 Z9 0 U1 0 U2 0 PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017-2394 SN 0148-6411 J9 IEEE T COMPON HYBR PD SEP PY 1991 VL 14 IS 3 BP 462 EP 466 DI 10.1109/33.83928 PG 5 WC Engineering, Manufacturing; Engineering, Electrical & Electronic; Materials Science, Multidisciplinary SC Engineering; Materials Science GA GC910 UT WOS:A1991GC91000004 ER PT J AU SWEET, JN TUCK, MR PETERSON, DW PALMER, DW AF SWEET, JN TUCK, MR PETERSON, DW PALMER, DW TI SHORT AND LONG LOOP MANUFACTURING FEEDBACK USING A MULTISENSOR ASSEMBLY TEST CHIP SO IEEE TRANSACTIONS ON COMPONENTS HYBRIDS AND MANUFACTURING TECHNOLOGY LA English DT Article AB A family of silicon test chips has been developed for use in making diagnostic measurements during electronics assembly. These assembly test chips (ATC's) contain sensors that measure a number of variables associated with assembled IC degradation; including, the degree of integrated circuit (IC) corrosion, handling damage, ESD threat, ppm(v) moisture or humidity, mechanical stress, mobile ion density, bond pad cratering, and high-speed logic degradation. The chips in the ATC family are intended to give manufacturing feedback in four ways: direct feedback in evaluation of an assembly manufacturing line in an objective, nonintrusive way; before and after comparisons on an assembly production line when an individual process, material, or piece of equipment has been changed; resident lifetime monitor for system package aging and ongoing reliability projection; and thermal, mechanical, dc electrical, and high frequency mock-up evaluation of packaging (including multichip) schemes. RP SWEET, JN (reprint author), SANDIA NATL LABS,DIV PACKAGING TECHNOL 2134,ALBUQUERQUE,NM 87185, USA. NR 14 TC 6 Z9 6 U1 0 U2 0 PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017-2394 SN 0148-6411 J9 IEEE T COMPON HYBR PD SEP PY 1991 VL 14 IS 3 BP 529 EP 535 DI 10.1109/33.83939 PG 7 WC Engineering, Manufacturing; Engineering, Electrical & Electronic; Materials Science, Multidisciplinary SC Engineering; Materials Science GA GC910 UT WOS:A1991GC91000015 ER PT J AU FITCH, JP LEHMAN, SK DOWLA, FU LU, SY JOHANSSON, EM GOODMAN, DM AF FITCH, JP LEHMAN, SK DOWLA, FU LU, SY JOHANSSON, EM GOODMAN, DM TI SHIP WAKE-DETECTION PROCEDURE USING CONJUGATE-GRADIENT TRAINED ARTIFICIAL NEURAL NETWORKS SO IEEE TRANSACTIONS ON GEOSCIENCE AND REMOTE SENSING LA English DT Article AB A method has been developed to reduce large two-dimensional images to significantly smaller "feature lists." These feature lists overcome the problem of storing and manipulating large amounts of data. A new artificial neural network using conjugate gradient training methods, operating on sets of feature lists, was successfully trained to determine the presence or absence of wakes in synthetic aperture radar images. A comparison has been made between the different conjugate gradient and steepest-descent training methods and has demonstrated the superiority of the former over the latter. RP FITCH, JP (reprint author), UNIV CALIF LAWRENCE LIVERMORE NATL LAB,POB 808L-496,LIVERMORE,CA 94550, USA. NR 13 TC 26 Z9 30 U1 2 U2 3 PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017-2394 SN 0196-2892 J9 IEEE T GEOSCI REMOTE JI IEEE Trans. Geosci. Remote Sensing PD SEP PY 1991 VL 29 IS 5 BP 718 EP 726 DI 10.1109/36.83986 PG 9 WC Geochemistry & Geophysics; Engineering, Electrical & Electronic; Remote Sensing; Imaging Science & Photographic Technology SC Geochemistry & Geophysics; Engineering; Remote Sensing; Imaging Science & Photographic Technology GA GD090 UT WOS:A1991GD09000004 ER PT J AU HODGDON, ML HIXSON, RS PARSONS, WM AF HODGDON, ML HIXSON, RS PARSONS, WM TI COMPUTATION OF THE CURRENT-DENSITY IN NONLINEAR MATERIALS SUBJECTED TO LARGE CURRENT PULSES SO IEEE TRANSACTIONS ON MAGNETICS LA English DT Article; Proceedings Paper CT 4TH BIENNIAL CONF ON ELECTROMAGNETIC FIELD COMPUTATION CY OCT 22-24, 1990 CL TORONTO, CANADA SP IEEE AB The finite element method and the finite difference method are used to calculate the current distribution in two nonlinear conductors. The first conductor is a small ferromagnetic wire subjected to a current pulse that rises to 10,000 Amperes in 10 microseconds. Results from the transient thermal and transient magnetic solvers of the finite element code FLUX2D are used to compute the current density in the wire. The second conductor is a metal oxide varistor. Maxwell's equations, Ohm's law and the varistor relation for the resistivity and the current density of rho = alpha-j-beta are used to derive a nonlinear differential equation. The solutions of the differential equation are obtained by a finite difference approximation and a shooting method. The behavior predicted by these calculations is in agreement with experiments. RP HODGDON, ML (reprint author), UNIV CALIF LOS ALAMOS SCI LAB,LOS ALAMOS,NM 87545, USA. NR 9 TC 0 Z9 0 U1 0 U2 0 PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017-2394 SN 0018-9464 J9 IEEE T MAGN JI IEEE Trans. Magn. PD SEP PY 1991 VL 27 IS 5 BP 4101 EP 4104 DI 10.1109/20.105004 PG 4 WC Engineering, Electrical & Electronic; Physics, Applied SC Engineering; Physics GA GT689 UT WOS:A1991GT68900081 ER PT J AU TURNER, LR KIM, SH THOMPSON, KM AF TURNER, LR KIM, SH THOMPSON, KM TI COMPUTATION OF A QUADRUPOLE MAGNET FOR THE APS STORAGE RING SO IEEE TRANSACTIONS ON MAGNETICS LA English DT Article; Proceedings Paper CT 4TH BIENNIAL CONF ON ELECTROMAGNETIC FIELD COMPUTATION CY OCT 22-24, 1990 CL TORONTO, CANADA SP IEEE AB The storage ring of the Advanced Photon Source will include 400 quadrupole magnets for focusing the beam. A prototype quadrupole has been designed, constructed, and measured. This paper describes the two- and three-dimensional (2-D and 3-D) field computations performed for this design. RP TURNER, LR (reprint author), ARGONNE NATL LAB,DIV ACCELERATOR SYST,ARGONNE,IL 60439, USA. NR 2 TC 0 Z9 0 U1 0 U2 2 PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017-2394 SN 0018-9464 J9 IEEE T MAGN JI IEEE Trans. Magn. PD SEP PY 1991 VL 27 IS 5 BP 4231 EP 4234 DI 10.1109/20.105035 PG 4 WC Engineering, Electrical & Electronic; Physics, Applied SC Engineering; Physics GA GT689 UT WOS:A1991GT68900113 ER PT J AU JOHNSON, WA WARNE, LK AF JOHNSON, WA WARNE, LK TI A STEEP FRONT APPROXIMATION AS THE SOLUTION TO NONLINEAR DIFFUSION INTO A HALF-SPACE OF FERROMAGNETIC MATERIAL SO IEEE TRANSACTIONS ON MAGNETICS LA English DT Article; Proceedings Paper CT 4TH BIENNIAL CONF ON ELECTROMAGNETIC FIELD COMPUTATION CY OCT 22-24, 1990 CL TORONTO, CANADA SP IEEE AB A steep front approximation for nonlinear diffusion into a ferromagnetic half-space is developed. This approximation is valid under the assumption of large driving H fields. The neglect of the flux under this front results in a forward shift of the H-field profile. To approximately correct for this shift, a shifted steep front solution is introduced. An L-G transmission line model is introduced to provide a comparison with these approximate solutions. RP JOHNSON, WA (reprint author), SANDIA NATL LABS,DIV ELECTROMAGNET ANAL,ALBUQUERQUE,NM 87185, USA. NR 7 TC 3 Z9 3 U1 0 U2 0 PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017-2394 SN 0018-9464 J9 IEEE T MAGN JI IEEE Trans. Magn. PD SEP PY 1991 VL 27 IS 5 BP 4322 EP 4327 DI 10.1109/20.105057 PG 6 WC Engineering, Electrical & Electronic; Physics, Applied SC Engineering; Physics GA GT689 UT WOS:A1991GT68900134 ER PT J AU CINOTTI, L BAZIN, JP SUSSKIND, H BRILL, AB AF CINOTTI, L BAZIN, JP SUSSKIND, H BRILL, AB TI PROCESSING OF XE-127 REGIONAL PULMONARY VENTILATION BY FACTOR-ANALYSIS AND COMPARTMENTAL MODELING SO IEEE TRANSACTIONS ON MEDICAL IMAGING LA English DT Article AB Scintigraphic imaging sums up all the photons emitted from different overlying regions. Hence, compartmental modeling of the data becomes difficult since the kinetics of the various compartments are mixed together. Therefore, we were interested in testing a method providing estimated solutions of these elementary kinetics. The regional lung ventilation was modeled in 5 cases using Xe-127 during the first 3 min of wash-out. A factor analysis of dynamic structures algorithm allowed us to estimate elementary kinetics and their respective proportions contained in time series images. Each factor was interpreted as the sampling of a compartment. It was associated to a factor image representing its spatial distribution and to a percentage of the total collected information. In our study, three factors were estimated. Factor analysis demonstrated two pulmonary factors: one was a fast clearance in the lower lung regions (28.9%); the second with a slower clearance in the upper regions (33.4%). A third factor described a slow kinetics in blood and tissues containing dissolved xenon (37.%). These factors were simultaneously fitted by a three-compartment model (two for the lungs and one for the tissues). The quality of the fit depended on intra pulmonary exchanges between the two pulmonary compartments which could describe the pathological character of the ventilation. The differences between pulmonary compartment volumes and the total lung capacity were due to gamma-rays chest tissue attenuation. We estimated the thickness corresponding to this attenuation and compared it to chest X-rays findings to validate our model. A compartmental analysis performed with the classical region of interest method could not be validated, negative values being found for tissue thickness. C1 UNIV MASSACHUSETTS,MED CTR,DEPT NUCL MED,WORCESTER,MA 01655. BROOKHAVEN NATL LAB,DEPT MED,UPTON,NY 11973. RP CINOTTI, L (reprint author), INST GUSTAVE ROUSSY,INSERM,U66,F-94800 VILLEJUIF,FRANCE. NR 19 TC 6 Z9 6 U1 0 U2 1 PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017-2394 SN 0278-0062 J9 IEEE T MED IMAGING JI IEEE Trans. Med. Imaging PD SEP PY 1991 VL 10 IS 3 BP 437 EP 444 DI 10.1109/42.97594 PG 8 WC Computer Science, Interdisciplinary Applications; Engineering, Biomedical; Engineering, Electrical & Electronic; Imaging Science & Photographic Technology; Radiology, Nuclear Medicine & Medical Imaging SC Computer Science; Engineering; Imaging Science & Photographic Technology; Radiology, Nuclear Medicine & Medical Imaging GA GH744 UT WOS:A1991GH74400025 PM 18222846 ER PT J AU COOKE, DW ARENDT, PN GRAY, ER PORTIS, AM AF COOKE, DW ARENDT, PN GRAY, ER PORTIS, AM TI ABSORPTION AT HIGH MICROWAVE-POWER BY LARGE-AREA TL-BASED SUPERCONDUCTING FILMS ON METALLIC SUBSTRATES SO IEEE TRANSACTIONS ON MICROWAVE THEORY AND TECHNIQUES LA English DT Article ID HIGH-TC SUPERCONDUCTORS; SURFACE-RESISTANCE; MAGNETIC-FIELD; THIN-FILMS; CU-O; YBA2CU3O7-X; IMPEDANCE; LINE; GHZ AB Microwave surface resistance measurements have been made on large-area Tl-Ba-Ca-Cu-O thick films that are magnetron-sputtered onto oriented Ag alloy substrates by replacing the end wall of an 18 GHz TE011 mode Cu cavity with the superconducting film. The best surface resistance values obtained are 4 and 14 m-OMEGA at 10 K and 77 K, respectively; corresponding Cu values are 8 m-OMEGA and 21 m-OMEGA. The dependence of the surface resistance on microwave power was measured in a similar way except that a Nb cavity was used instead of a Cu cavity. Typically, the surface resistance of the film begins to rise in 1-10 Oe of microwave field and saturates in 20-60 Oe. A model is presented relating the observed saturation to critical penetration of Josephson junctions. Films exhibiting the highest degree of c-axis texturing show the weakest dependence of surface resistance on power and also exhibit the sharpest transition to the superconducting state as measured at high frequency. These results are important for the development of high-power microwave cavities. C1 UNIV CALIF BERKELEY LAWRENCE BERKELEY LAB,DIV MAT SCI,BERKELEY,CA 94720. RP COOKE, DW (reprint author), UNIV CALIF LOS ALAMOS SCI LAB,RES PROGRAM,LOS ALAMOS,NM 87545, USA. NR 32 TC 8 Z9 8 U1 0 U2 0 PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017-2394 SN 0018-9480 J9 IEEE T MICROW THEORY JI IEEE Trans. Microw. Theory Tech. PD SEP PY 1991 VL 39 IS 9 BP 1539 EP 1544 DI 10.1109/22.83829 PG 6 WC Engineering, Electrical & Electronic SC Engineering GA GA255 UT WOS:A1991GA25500015 ER PT J AU HOCHBERG, J MNISZEWSKI, SM CALLEJA, T PAPCUN, GJ AF HOCHBERG, J MNISZEWSKI, SM CALLEJA, T PAPCUN, GJ TI A DEFAULT HIERARCHY FOR PRONOUNCING ENGLISH SO IEEE TRANSACTIONS ON PATTERN ANALYSIS AND MACHINE INTELLIGENCE LA English DT Letter DE ARTIFICIAL INTELLIGENCE; DEFAULT HIERARCHIES; DEFAULT REASONING; INDUCTION; KNOWLEDGE REPRESENTATION; LEARNING; SPEECH SYNTHESIS; SPELLING AB In this correspondence, we study the principles governing the power and efficiency of the default hierarchy, a system of knowledge acquisition and representation. The default hierarchy consists of clear and accessible rules, like an expert-made system, but trains automatically when exposed to data, like a neural network. The hierarchy has both general (default) and specific rules. In training, specific rules are learned only if they are exceptions to general rules; in using the hierarchy, default rules are used when no relevant specific rules are found. Our application of the default hierarchy to the task of pronouncing written English reveals interesting properties of the default hierarchy architecture. We find that the hierarchy performs best when there is free access to general rules, and that it is less than 1/4 the size of a comparable nonhierarchial rule set while no less accurate in pronunciation. Evaluating the hierarchy as a pronouncer of English, we find that its rules capture several key features of English spelling. Moreover, the default hierarchy pronounces English better than the neural network NETtalk, and almost as well as expert-devised systems (DECtalk and the Naval Research Laboratory's pronunciation system). RP HOCHBERG, J (reprint author), UNIV CALIF LOS ALAMOS SCI LAB,LOS ALAMOS,NM 87545, USA. NR 21 TC 6 Z9 6 U1 0 U2 0 PU IEEE COMPUTER SOC PI LOS ALAMITOS PA 10662 LOS VAQUEROS CIRCLE, PO BOX 3014, LOS ALAMITOS, CA 90720-1264 SN 0162-8828 J9 IEEE T PATTERN ANAL JI IEEE Trans. Pattern Anal. Mach. Intell. PD SEP PY 1991 VL 13 IS 9 BP 957 EP 964 DI 10.1109/34.93813 PG 8 WC Computer Science, Artificial Intelligence; Engineering, Electrical & Electronic SC Computer Science; Engineering GA GJ180 UT WOS:A1991GJ18000009 ER PT J AU PIN, FG BELMANS, PFR HRUSKA, SI STEIDLEY, CW PARKER, LE AF PIN, FG BELMANS, PFR HRUSKA, SI STEIDLEY, CW PARKER, LE TI ROBOTIC LEARNING FROM DISTRIBUTED SENSORY SOURCES SO IEEE TRANSACTIONS ON SYSTEMS MAN AND CYBERNETICS LA English DT Letter ID AUTONOMOUS MOBILE ROBOT AB Much of the existing work on machine learning has focused on highly cognitive-based inferencing. Learning by an autonomous robot using these methods, however, is highly dependent upon and currently constrained by the sensor data interpretation capabilities of the robot perception systems. The paper describes recent work toward the development of low complexity, sensor-based inferencing methods to serve as the initial links of incremental robotic learning systems. A multimodal learning approach is proposed in which distributed sensory sources are used to both trigger the observation of and perceive relevant learning instances in a human-robot synergistic framework. Three components of the incremental learning system for the CESARm advanced manipulator test-bed are presented that encompass the learning of objects and work area characteristics through the triggering of attention and rote learning, the learning of elemental manipulation tasks by observation of human actions, and the self-assessment of acquired skills and learned knowledge through task performance evaluation. Feasibility experiments with each of these three learning methodologies are presented and some sample results are discussed. C1 FLORIDA STATE UNIV,DEPT COMP SCI,TALLAHASSEE,FL 32306. CENT WASHINGTON UNIV,DEPT COMP SCI,ELLENSBURG,WA 98926. RP PIN, FG (reprint author), OAK RIDGE NATL LAB,CTR ENGN SYST ADV RES,AUTONOMOUS ROBOT SYST GRP,OAK RIDGE,TN 37831, USA. NR 34 TC 0 Z9 0 U1 1 U2 2 PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017-2394 SN 0018-9472 J9 IEEE T SYST MAN CYB JI IEEE Trans. Syst. Man Cybern. PD SEP-OCT PY 1991 VL 21 IS 5 BP 1216 EP 1223 DI 10.1109/21.120073 PG 8 WC Computer Science, Cybernetics; Engineering, Electrical & Electronic SC Computer Science; Engineering GA HG003 UT WOS:A1991HG00300027 ER PT J AU SCHWARZ, RI AF SCHWARZ, RI TI CELL-TO-CELL SIGNALING IN THE REGULATION OF PROCOLLAGEN EXPRESSION IN PRIMARY AVIAN TENDON CELLS SO IN VITRO CELLULAR & DEVELOPMENTAL BIOLOGY LA English DT Article DE PROCOLLAGEN; PROCELLAGEN MESSENGER RNA; CELL DENSITY; TENDON CELLS; INSITU HYBRIDIZATION ID INSITU HYBRIDIZATION; MESSENGER-RNAS; DIFFERENTIATED STATE; COLLAGEN; FIBROBLASTS; ASCORBATE; GROWTH; DEGRADATION; PROBES; MOUSE AB High cell density is required for high procollagen expression (50% of total protein synthesis) in primary avian tendon (PAT) cells but the signaling mechanism that triggers this response has been difficult to decipher. By using a quantitative in situ hybridization assay for procollagen mRNA, cell density dependent changes in procollagen expression can be followed at the single cell level. PAT cells can then be shown to respond to the presence of their neighbors over approximately 1-mm distance. The cell density signal remains effective independent of the medium volume to cell ratio but becomes sensitive to dispersion and dilution when the medium is agitated. PAT cells respond to a reduction in cell density, when neighboring cells are scraped away, by outgrowth (approximately 1 mm) and reestablishment of a cell density gradient in cellular procollagen mRNA levels. However, removing neighboring cells while preventing migration off of their own extracellular matrix retards the drop in procollagen mRNA levels. The evidence, taken as a whole, is consistent with a model whereby the cell density signal is a loosely bound component of the cell layer thereby restricting its diffusion to two dimensions but making it susceptible to dispersion by medium agitation. RP SCHWARZ, RI (reprint author), UNIV CALIF BERKELEY LAWRENCE BERKELEY LAB,DIV CELL & MOLEC BIOL,BLDG 934,BERKELEY,CA 94720, USA. NR 27 TC 4 Z9 4 U1 0 U2 0 PU SOC IN VITRO BIOLOGY PI COLUMBIA PA 8815 CENTRE PARK DRIVE SUITE 210, COLUMBIA, MD 21045 SN 0073-5655 J9 IN VITRO CELL DEV B PD SEP PY 1991 VL 27 IS 9 BP 698 EP 706 PG 9 WC Cell Biology; Developmental Biology SC Cell Biology; Developmental Biology GA GK634 UT WOS:A1991GK63400006 ER PT J AU ALDE, D BINON, F GOUANERE, M DONSKOV, SV INYAKIN, AV KACHANOV, VA LOPEZ, T MIKHAILOV, YV KNAPP, EA PEIGNEUX, JP PROKOSHKIN, YD SAMOILENKO, VD SINGOVSKII, AV STROOT, JP SUGONYAEV, VP SHAGIN, PM AF ALDE, D BINON, F GOUANERE, M DONSKOV, SV INYAKIN, AV KACHANOV, VA LOPEZ, T MIKHAILOV, YV KNAPP, EA PEIGNEUX, JP PROKOSHKIN, YD SAMOILENKO, VD SINGOVSKII, AV STROOT, JP SUGONYAEV, VP SHAGIN, PM TI USE OF GAMS-2000 HODOSCOPE SPECTROMETER TO TRIGGER AN APPARATUS FOR STUDY OF NEUTRAL-MESON PRODUCTION SO INSTRUMENTS AND EXPERIMENTAL TECHNIQUES LA English DT Article ID SYSTEM AB A system for analog summation of the signals of the 1532 counters of the GAMS-2000 hodoscope calorimeter is described that is designed for fast (30-nsec) determination of gamma-quantum (electron) energy. The system is implemented by active adders connected in three summation stages. A differential discriminator with a variable threshold and a fast parallel analog-to-digital converter with a noise-reduction circuit are used for amplitude analysis under conditions of coherent noise. The system was used in an experiment to study meson production in central hadron collisions on the 70-GeV accelerator of the Institute of High-Energy Physics. C1 SERPUKHOV HIGH ENERGY PHYS INST, SERPUKHOV, USSR. RP UNIV CALIF LOS ALAMOS SCI LAB, LOS ALAMOS, NM 87544 USA. NR 16 TC 0 Z9 0 U1 0 U2 0 PU MAIK NAUKA/INTERPERIODICA/SPRINGER PI NEW YORK PA 233 SPRING ST, NEW YORK, NY 10013-1578 USA SN 0020-4412 EI 1608-3180 J9 INSTRUM EXP TECH+ JI Instrum. Exp. Tech. PD SEP-OCT PY 1991 VL 34 IS 5 BP 1036 EP 1040 PN 1 PG 5 WC Engineering, Multidisciplinary; Instruments & Instrumentation SC Engineering; Instruments & Instrumentation GA HP650 UT WOS:A1991HP65000007 ER PT J AU BLACKER, TD STEPHENSON, MB AF BLACKER, TD STEPHENSON, MB TI PAVING - A NEW APPROACH TO AUTOMATED QUADRILATERAL MESH GENERATION SO INTERNATIONAL JOURNAL FOR NUMERICAL METHODS IN ENGINEERING LA English DT Article AB This paper presents a new mesh generation technique, paving, which meshes arbitrary 2-D geometries with an all-quadrilateral mesh. Paving allows varying element size distributions on the boundary as well as the interior of a region. The generated mesh is well formed (i.e. nearly square elements, elements perpendicular to boundaries, etc.) and geometrically pleasing (i.e. mesh contours tend to follow geometric contours of the boundary). In this paper we describe the theory behind this algorithmic/heuristic technique, evaluate the performance of the approach and present examples of automatically generated meshes. C1 BRIGHAM YOUNG UNIV,DEPT CIVIL ENGN,PROVO,UT 84602. RP BLACKER, TD (reprint author), SANDIA NATL LABS,DIV APPL MECH 3,ALBUQUERQUE,NM 87185, USA. NR 17 TC 265 Z9 292 U1 2 U2 14 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 SEP PY 1991 VL 32 IS 4 BP 811 EP 847 DI 10.1002/nme.1620320410 PG 37 WC Engineering, Multidisciplinary; Mathematics, Interdisciplinary Applications SC Engineering; Mathematics GA GF717 UT WOS:A1991GF71700009 ER PT J AU CHAPPIDI, PR PASAMEHMETOGLU, KO GUNNERSON, FS AF CHAPPIDI, PR PASAMEHMETOGLU, KO GUNNERSON, FS TI THE INFLUENCE OF SURFACE RADIATION ON LAMINAR FORCED-CONVECTION FILM BOILING SO INTERNATIONAL JOURNAL OF HEAT AND FLUID FLOW LA English DT Article DE FILM BOILING; FORCED CONVECTION; RADIATION AB A new approach to address the effect of surface radiation on a laminar film boiling flow over a horizontal flat plate is suggested. Previously developed approximate expressions of the thermal boundary-layer thickness and the wall shear stress of a moving surface in a flowing liquid are used to circumvent the complicated simultaneous solution of the vapor and liquid flow. Approximate closed-form expressions to predict the wall heat transfer and skin friction are obtained. For a water-steam system at atmospheric pressure within the wall temperature range considered (T(w) < 800-degrees-C), the surface radiation contribution is negligible in the theoretical wall heat transfer predictions during subcooled T infinity = 20-degrees-C forced-convection film boiling. RP CHAPPIDI, PR (reprint author), UNIV CALIF LOS ALAMOS SCI LAB,DIV NUCL TECHNOL & ENGN,MAIL STOP K559,LOS ALAMOS,NM 87544, USA. NR 0 TC 0 Z9 0 U1 1 U2 1 PU BUTTERWORTH-HEINEMANN PI WOBURN PA 225 WILDWOOD AVE #UNITB PO BOX 4500, WOBURN, MA 01801-2084 SN 0142-727X J9 INT J HEAT FLUID FL JI Int. J. Heat Fluid Flow PD SEP PY 1991 VL 12 IS 3 BP 225 EP 232 DI 10.1016/0142-727X(91)90056-2 PG 8 WC Thermodynamics; Engineering, Mechanical; Mechanics SC Thermodynamics; Engineering; Mechanics GA GE338 UT WOS:A1991GE33800005 ER PT J AU BUTTERMORE, WH SLOMKA, BJ AF BUTTERMORE, WH SLOMKA, BJ TI THE EFFECT OF SONIC TREATMENT ON THE FLOTABILITY OF OXIDIZED COAL SO INTERNATIONAL JOURNAL OF MINERAL PROCESSING LA English DT Article ID FLOTATION AB Microflotation tests using a Hallimond tube were performed to study the effects of sonic treatment on the flotability of oxidized coals. The experiments revealed a significant decrease in coal flotability as a result of oxidation in dry air at 150-degrees-C for 150 h. Sonication of the oxidized coals in aqueous slurry restored the flotability to a level near or exceeding that of fresh coal. Washing oxidized coal without sonication effected only minor improvements in flotabilities. RP BUTTERMORE, WH (reprint author), IOWA STATE UNIV SCI & TECHNOL,AMES LAB,AMES,IA 50011, USA. NR 7 TC 10 Z9 10 U1 0 U2 0 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0301-7516 J9 INT J MINER PROCESS JI Int. J. Miner. Process. PD SEP PY 1991 VL 32 IS 3-4 BP 251 EP 257 DI 10.1016/0301-7516(91)90071-P PG 7 WC Engineering, Chemical; Mineralogy; Mining & Mineral Processing SC Engineering; Mineralogy; Mining & Mineral Processing GA GJ593 UT WOS:A1991GJ59300006 ER PT J AU MAHAN, GD AF MAHAN, GD TI PIEZOELECTRICITY IN INSULATORS SO INTERNATIONAL JOURNAL OF MODERN PHYSICS B LA English DT Article AB A microscopic theory is presented for the piezoelectric constants of zincblende. The theory is valid for ionic crystals. The constants have several contributions: one from long-range Coulomb interactions, and several from short range forces. The long-range term is given only by the dielectric function. The short-range terms are also large and nearly cancel the long-range terms: the largest is from the deformation-dipole term. The agreement between theory and experiment is a sensitive test of theories of short-range polarization in solids. RP MAHAN, GD (reprint author), OAK RIDGE NATL LAB,DIV SOLID STATE,OAK RIDGE,TN 37831, USA. NR 0 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 SEP PY 1991 VL 5 IS 15 BP 2531 EP 2549 DI 10.1142/S0217979291000997 PG 19 WC Physics, Applied; Physics, Condensed Matter; Physics, Mathematical SC Physics GA GM389 UT WOS:A1991GM38900005 ER PT J AU HUGHES, ED DUFFEY, RB AF HUGHES, ED DUFFEY, RB TI DIRECT CONTACT CONDENSATION AND MOMENTUM-TRANSFER IN TURBULENT SEPARATED FLOWS SO INTERNATIONAL JOURNAL OF MULTIPHASE FLOW LA English DT Article DE CONDENSATION; HEAT TRANSFER; TURBULENCE; DISSIPATION ID GAS-LIQUID FLOWS; HEAT-TRANSFER COEFFICIENT; MASS-TRANSFER; FALLING FILMS; PRESSURE-DROP; PIPE-FLOW; ABSORPTION; WATER; SURFACE; HOLDUP AB Analysis of the turbulent velocity and shear stress distribution in a separated two-phase flow shows that both the wall and interface shear contribute to the dissipation of energy in the liquid film. A suitably averaged turbulent energy dissipation provides Kolmogorov velocity and length scales in the liquid film. These scales are used in a turbulent eddy based surface renewal theory for condensation and evaporation of saturated vapor onto or from its liquid. The theory accurately predicts experimental data for horizontal, concurrent condensation of steam on water. Theoretical results agree with the form of existing turbulent correlations for heat and mass transfer processes such as condensation onto a falling liquid film and mass, momentum and heat transfer at the interface in separated flows. Comparison of the theory to previous work is included and guidelines for empirical correlations of data are given. RP EG&G IDAHO INC, IDAHO NATL ENGN LAB, IDAHO FALLS, ID 83415 USA. NR 67 TC 36 Z9 36 U1 1 U2 12 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLAND SN 0301-9322 EI 1879-3533 J9 INT J MULTIPHAS FLOW JI Int. J. Multiph. Flow PD SEP-OCT PY 1991 VL 17 IS 5 BP 599 EP 619 DI 10.1016/0301-9322(91)90027-Z PG 21 WC Mechanics SC Mechanics GA GK629 UT WOS:A1991GK62900004 ER PT J AU WILSON, A KAUFMANN, MH DAYAN, AD GOODHEAD, DT SIKOV, MR MEZNARICH, HK TRAUB, RJ HARRISON, JD MORGAN, A HAINES, JW STATHER, JW LORD, BI MASON, TM MOLE, RH HUMPHREYS, ER AF WILSON, A KAUFMANN, MH DAYAN, AD GOODHEAD, DT SIKOV, MR MEZNARICH, HK TRAUB, RJ HARRISON, JD MORGAN, A HAINES, JW STATHER, JW LORD, BI MASON, TM MOLE, RH HUMPHREYS, ER TI CEIR FORUM ON RADIONUCLIDES AND EXTERNAL IRRADIATION - IMPLICATIONS FOR THE EMBRYO AND FETUS SO INTERNATIONAL JOURNAL OF RADIATION BIOLOGY LA English DT Discussion ID CHILDHOOD-CANCER; BOMB RADIATION; X-RAY; NUCLEAR INSTALLATIONS; MENTAL-RETARDATION; PRENATAL EXPOSURE; CHILDREN BORN; YOUNG-PEOPLE; LEUKEMIA; CUMBRIA C1 UNIV EDINBURGH, SCH MED, DEPT ANAT, EDINBURGH EH8 9AG, MIDLOTHIAN, SCOTLAND. ST BARTHOLOMEWS HOSP, COLL MED, CTR RES, DH DEPT TOXICOL, LONDON EC1 7ED, ENGLAND. PACIFIC NW LAB, CTR LIFE SCI, RICHLAND, WA 99352 USA. NATL RADIOL PROTECT BOARD, DIDCOT OX11 0RQ, OXON, ENGLAND. CHRISTIE HOSP & HOLT RADIUM INST, PATERSON INST CANC RES, MANCHESTER M20 9BX, LANCS, ENGLAND. RP WILSON, A (reprint author), MRC, RADIOBIOL UNIT, DIDCOT OX11 0RD, OXON, ENGLAND. NR 73 TC 2 Z9 2 U1 0 U2 0 PU TAYLOR & FRANCIS LTD PI LONDON PA ONE GUNDPOWDER SQUARE, LONDON, ENGLAND EC4A 3DE SN 0955-3002 J9 INT J RADIAT BIOL JI Int. J. Radiat. Biol. PD SEP PY 1991 VL 60 IS 3 BP 543 EP 569 DI 10.1080/09553009114552381 PG 27 WC Biology; Nuclear Science & Technology; Radiology, Nuclear Medicine & Medical Imaging SC Life Sciences & Biomedicine - Other Topics; Nuclear Science & Technology; Radiology, Nuclear Medicine & Medical Imaging GA GE328 UT WOS:A1991GE32800011 ER PT J AU HORIUCHI, H KOBAYASHI, T SCHULTZ, AJ AF HORIUCHI, H KOBAYASHI, T SCHULTZ, AJ TI TIME-OF-FLIGHT PULSED NEUTRON-DIFFRACTION STUDY ON UNIAXIAL STRESS-INDUCED DOMAIN SWITCHING IN LANBO4 SO JAPANESE JOURNAL OF APPLIED PHYSICS PART 1-REGULAR PAPERS SHORT NOTES & REVIEW PAPERS LA English DT Article DE TOF NEUTRON DIFFRACTION; LANTHANUM NIOBATE; FERROELASTIC MATERIAL; DOMAIN SWITCHING; DOMAIN STRUCTURE; STRESS EFFECTS ID CRYSTALS AB The domain orientation switching phenomena in the ferroelastic material LaNbO4 were observed by means of a time-of-flight neutron diffraction technique using a position-sensitive area detector. When stress is applied to the direction nearly perpendicular to (100) of one of the domains in the specimen, the a- and c-axes are easily transformed into the c- and a-axes of another domain, respectively. The domains with [001] nearly parallel to the stress direction do not switch orientation. Thus, the domain which occupied 34% of the specimen at the initial stage expanded up to 92% of the total volume by switching from other orientated domains. The estimated stress was 600 gW/mm2 at the final stage. The mechanism of switching orientation can structurally be interpreted by a small rotation and a small displacement of NbO4 tetrahedra at the domain boundary which is a transient zone with a prototype structure. C1 HOKURIKU UNIV,SCH PHARM,KANAZAWA,ISHIKAWA 92011,JAPAN. ARGONNE NATL LAB,DIV CHEM,ARGONNE,IL 60439. ARGONNE NATL LAB,DIV MAT SCI & TECHNOL,ARGONNE,IL 60439. RP HORIUCHI, H (reprint author), UNIV TOKYO,FAC SCI,INST MINERAL,BUNKYO KU,TOKYO 113,JAPAN. NR 7 TC 4 Z9 4 U1 0 U2 0 PU JAPAN J APPLIED PHYSICS PI MINATO-KU TOKYO PA DAINI TOYOKAIJI BLDG 24-8 SHINBASHI 4-CHOME, MINATO-KU TOKYO 105, JAPAN SN 0021-4922 J9 JPN J APPL PHYS 1 JI Jpn. J. Appl. Phys. Part 1 - Regul. Pap. Short Notes Rev. Pap. PD SEP PY 1991 VL 30 IS 9A BP 2035 EP 2039 DI 10.1143/JJAP.30.2035 PG 5 WC Physics, Applied SC Physics GA GX702 UT WOS:A1991GX70200029 ER PT J AU ROMAN, YG STINTON, DP BESMANN, TM AF ROMAN, YG STINTON, DP BESMANN, TM TI DEVELOPMENT OF HIGH-DENSITY FIBER REINFORCED SILICON-CARBIDE FCVI COMPOSITES SO JOURNAL DE PHYSIQUE IV LA English DT Article AB Silicon carbide continuous fiber reinforced composites are prepared by Forced flow thermal gradient Chemical Vapor Infiltration. In order to obtain high density and homogeneous ceramic composites the effects of time and thermal gradient across the preform are studied during infiltration. Cross sections of the infiltrated composites are studied with the aid of optical microscopy and image analysis. This manuscript gives an impression of the experimental composite densities and density gradients achieved and critical aspects that play a role in the infiltration process. C1 OAK RIDGE NATL LAB, DIV MET & CERAM, OAK RIDGE, TN 37831 USA. RP ROMAN, YG (reprint author), CTR TECH CERAM, POB 595, 5600 AN EINDHOVEN, NETHERLANDS. NR 1 TC 3 Z9 3 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 1155-4339 J9 J PHYS IV JI J. Phys. IV PD SEP PY 1991 VL 1 IS C2 BP 689 EP 695 PG 7 WC Physics, Multidisciplinary SC Physics GA GG301 UT WOS:A1991GG30100084 ER PT J AU CHANG, HLM GAO, Y GUO, J FOSTER, CM YOU, H ZHANG, TJ LAM, DJ AF CHANG, HLM GAO, Y GUO, J FOSTER, CM YOU, H ZHANG, TJ LAM, DJ TI HETEROEPITAXIAL GROWTH OF TIO2, VO2, AND TIO2/VO2 MULTILAYERS BY MOCVD SO JOURNAL DE PHYSIQUE IV LA English DT Article AB Titanium and vanadium dioxide systems were selected to study the MOCVD process for the growth of oxide epitaxial films. Single-crystal TiO2 and VO2 films in single and multilayered configurations have been successfully grown on sapphire (alpha-Al2O3) single-crystal substrates. Seven distinct epitaxial orientation relationships between the films and the substrates were observed. Discussion on these epitaxial relationships based on the consideration of atomic arrangements of the materials is presented. From our experimental results, we concluded that single layer films (both TiO2 and VO2) were grown by the nucleations of three-dimensional clusters. Quantum mechanical calculations of the electronic structures, charge distributions, and energetics of the free substrate surfaces were performed and some results are presented. RP CHANG, HLM (reprint author), ARGONNE NATL LAB, DIV MAT SCI, 9700 S CASS AVE, ARGONNE, IL 60439 USA. RI You, Hoydoo/A-6201-2011 OI You, Hoydoo/0000-0003-2996-9483 NR 13 TC 4 Z9 4 U1 0 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 1155-4339 J9 J PHYS IV JI J. Phys. IV PD SEP PY 1991 VL 1 IS C2 BP 953 EP 960 PG 8 WC Physics, Multidisciplinary SC Physics GA GG301 UT WOS:A1991GG30100116 ER PT J AU MACHA, JM BUFFINGTON, RJ HENFLING, JF VANEVERY, D HARRIS, JL AF MACHA, JM BUFFINGTON, RJ HENFLING, JF VANEVERY, D HARRIS, JL TI SLOTTED-WALL BLOCKAGE CORRECTIONS FOR DISKS AND PARACHUTES SO JOURNAL OF AIRCRAFT LA English DT Article AB Bluff shapes, including parachutes, often require large blockage corrections when tested in solid-wall wind tunnels. The magnitude of the correction is much smaller in test sections with slotted walls, but the blockage becomes a complicated function of model size, wall porosity, and upstream and downstream boundary conditions. Disk and parachute models were tested in a low-speed wind tunnel where the slotted-wall open area ratio and model axial position were systematically varied. In steady flow, the benefit of the wall slots was achieved asymptotically as the models were moved downstream from the leading edge of the slots, and this flow development length increased with decreasing wall porosity and increasing model size. The experiments with the parachutes provided the first quantitative information on wall interference and tunnel circuit response during the nonsteady inflation process. There was no observable blockage effect during the inflations with any of the slotted-wall configurations studied. RP MACHA, JM (reprint author), SANDIA NATL LABS,DIV PARACHUTE SYST,ALBUQUERQUE,NM 87185, USA. NR 0 TC 1 Z9 1 U1 0 U2 0 PU AMER INST AERONAUT ASTRONAUT PI RESTON PA 1801 ALEXANDER BELL DRIVE, STE 500, RESTON, VA 22091 SN 0021-8669 J9 J AIRCRAFT JI J. Aircr. PD SEP PY 1991 VL 28 IS 9 BP 592 EP 597 DI 10.2514/3.46069 PG 6 WC Engineering, Aerospace SC Engineering GA GF926 UT WOS:A1991GF92600008 ER PT J AU SUKENIK, A LEVY, RS LEVY, Y FALKOWSKI, PG DUBINSKY, Z AF SUKENIK, A LEVY, RS LEVY, Y FALKOWSKI, PG DUBINSKY, Z TI OPTIMIZING ALGAL BIOMASS PRODUCTION IN AN OUTDOOR POND - A SIMULATION-MODEL SO JOURNAL OF APPLIED PHYCOLOGY LA English DT Article DE ALGAL MASS CULTURE; AREAL DENSITY; ISOCHRYSIS; PHOTOSYNTHESIS; PRODUCTIVITY; RESPIRATION; SIMULATION MODEL ID PHOTOSYNTHETIC ENERGY-CONVERSION; DUNALIELLA-TERTIOLECTA; MASS-CULTURE; ISOCHRYSIS-GALBANA; CULTIVATION; MICROALGAE; IRRADIANCE; PHYTOPLANKTON; ADAPTATION; SYSTEMS AB A deterministic simulation model was developed to predict production rates of the marine prymnesiophyte Isochrysis galbana in an outdoor algal mass culture system. The model consists of photoadapation, gross photosynthesis and respiration sections. Actual physiological and biophysical laboratory data, obtained from steady state cultures grown under a wide range of irradiance levels, were used in calculating productivity. The resulting values were used to assess optimal operational parameters to maximize algal biomass production. The model predicted a yearly averaged production rate of 9.7 g C m-2d-1, which compared well with field data reported in the literature. The model evaluated the effect of pond depth and chlorophyll concentration on potential production rate in various seasons. The model predicted that a yearly averaged chlorophyll areal density of 0.65 g m-2 will yield the maximal production rate. Chlorophyll areal density should be seasonally adjusted to give maximal production. This adjustment could be done either by changing pond depth or chlorophyll concentration. The model predicted that under optimal operational conditions, the diurnal respiration losses averaged 35% of gross photosynthesis. The calculated growth rate for maximal productivity ranged between 0.15 and 0.24 d-1, suggesting an optimal hydraulic retention time of 6.7 and 4.2 d for various seasons. C1 BAR ILAN UNIV,DEPT LIFE SCI,IL-52100 RAMAT GAN,ISRAEL. BROOKHAVEN NATL LAB,DEPT APPL SCI,UPTON,NY 11973. RP SUKENIK, A (reprint author), NATL INST OCEANOG,ISRAEL OCEANOG & LIMNOL RES,TEL SHIKMONA POB 8030,IL-31080 HAIFA,ISRAEL. NR 25 TC 45 Z9 46 U1 0 U2 12 PU KLUWER ACADEMIC PUBL PI DORDRECHT PA SPUIBOULEVARD 50, PO BOX 17, 3300 AA DORDRECHT, NETHERLANDS SN 0921-8971 J9 J APPL PHYCOL JI J. Appl. Phycol. PD SEP PY 1991 VL 3 IS 3 BP 191 EP 201 DI 10.1007/BF00003577 PG 11 WC Biotechnology & Applied Microbiology; Marine & Freshwater Biology SC Biotechnology & Applied Microbiology; Marine & Freshwater Biology GA GU118 UT WOS:A1991GU11800001 ER PT J AU KRALL, NA ROSENTHAL, SE AF KRALL, NA ROSENTHAL, SE TI SIMULATING ELECTRON FLOW IN THE APPLIED-B DIODE SO JOURNAL OF APPLIED PHYSICS LA English DT Article ID MODE STABILITY PROPERTIES; APPLIED MAGNETIC-FIELD; ION DIODES; PLANAR DIODE AB Electron flow in and into an applied-B ion diode is calculated, including the effects of turbulence produced by streaming instabilities. A technique is developed for including these effects in a numerical simulation. The results of two-dimensional simulations using this technique in the electromagnetic particle-in-cell code MAGIC are presented. C1 SANDIA NATL LABS,ALBUQUERQUE,NM 87185. RP KRALL, NA (reprint author), KRALL ASSOCIATES,DEL MAR,CA 92014, USA. NR 23 TC 11 Z9 11 U1 0 U2 0 PU AMER INST PHYSICS PI WOODBURY PA CIRCULATION FULFILLMENT DIV, 500 SUNNYSIDE BLVD, WOODBURY, NY 11797-2999 SN 0021-8979 J9 J APPL PHYS JI J. Appl. Phys. PD SEP 1 PY 1991 VL 70 IS 5 BP 2542 EP 2551 DI 10.1063/1.349410 PG 10 WC Physics, Applied SC Physics GA GE658 UT WOS:A1991GE65800005 ER PT J AU VANOS, CFA KUNKEL, WB LEGUIJT, C LOS, J AF VANOS, CFA KUNKEL, WB LEGUIJT, C LOS, J TI MODELING OF H- SURFACE CONVERSION SOURCES - BINARY (H-BA) AND TERNARY (H-CS/W) CONVERTER ARRANGEMENTS SO JOURNAL OF APPLIED PHYSICS LA English DT Article ID CESIUM-ION-BOMBARDMENT; NEGATIVE HYDROGEN-IONS; TUNGSTEN SURFACE; DETACHMENT; COLLISIONS; INJECTION; COVERAGE; INTENSE; W(110) AB The production process for the formation of H- ions in a surface conversion source is sputtering of hydrogen atoms from the converter surface layers by incident positive ions, followed by electron attachment via resonant charge exchange with the converter surface. The sputtering process is in direct relation to the converter surface composition. New experimental data led us to identify two different classes of converters: metallic converters, like solid barium (binary) and adlayer converters, like cesium on tungsten (ternary). For a binary converter the hydrogen in the surface layers is directly sputtered by the incoming ions. Consequently, the negative ion yield scales with the hydrogen concentration in the surface layers. In the cesium/tungsten system (ternary) the hydrogen at surface is believed to be sandwiched between the cesium adlayer and the tungsten surface. Hence, the negative ion yield scales with the sputter coefficient of hydrogen on adsorbed cesium. This is experimentally confirmed. C1 UNIV CALIF BERKELEY LAWRENCE BERKELEY LAB,BERKELEY,CA 94720. EURATOM,FOM,INST ATOM & MOLEC PHYS,1098 SJ AMSTERDAM,NETHERLANDS. NR 33 TC 5 Z9 5 U1 1 U2 4 PU AMER INST PHYSICS PI WOODBURY PA CIRCULATION FULFILLMENT DIV, 500 SUNNYSIDE BLVD, WOODBURY, NY 11797-2999 SN 0021-8979 J9 J APPL PHYS JI J. Appl. Phys. PD SEP 1 PY 1991 VL 70 IS 5 BP 2575 EP 2583 DI 10.1063/1.349365 PG 9 WC Physics, Applied SC Physics GA GE658 UT WOS:A1991GE65800008 ER PT J AU PARK, KT CAO, JM GAO, Y WICKS, GW RUCKMAN, MW AF PARK, KT CAO, JM GAO, Y WICKS, GW RUCKMAN, MW TI GROWTH OF AL NITRIDE LAYERS ON GAAS(100) BY REACTION WITH CONDENSED AMMONIA SO JOURNAL OF APPLIED PHYSICS LA English DT Article ID MOLECULAR-BEAM EPITAXY; ALUMINUM NITRIDE; ROOM-TEMPERATURE; PHOTOEMISSION SPECTROSCOPY; ENCAPSULATING FILMS; ION-IMPLANTATION; METAL; INTERFACES; NITROGEN AB An Al nitride-GaAs(100) bilayer formed by deposition of Al into a solid ammonia overlayer on GaAs(100) at T = 100 K is studied using synchrotron radiation photoemission. Al does not react with NH3 to an appreciable amount at 100 K, but stable AIN layers are formed as the temperature of the substrate is raised to room temperature. The Al1-xN(x) layer formed is stable upon annealing up to 600 K, and detectable amounts of AlAs are not observed during deposition of 20 angstrom of Al into NH3 or after heating the sample to 300 K and higher. C1 UNIV ROCHESTER,INST OPT,ROCHESTER,NY 14627. BROOKHAVEN NATL LAB,DEPT PHYS,UPTON,NY 11973. RP PARK, KT (reprint author), UNIV ROCHESTER,DEPT PHYS & ASTRON,ROCHESTER,NY 14627, USA. RI Gao, Yongli/N-8392-2015 OI Gao, Yongli/0000-0001-9765-5246 NR 23 TC 8 Z9 8 U1 0 U2 0 PU AMER INST PHYSICS PI WOODBURY PA CIRCULATION FULFILLMENT DIV, 500 SUNNYSIDE BLVD, WOODBURY, NY 11797-2999 SN 0021-8979 J9 J APPL PHYS JI J. Appl. Phys. PD SEP 1 PY 1991 VL 70 IS 5 BP 2623 EP 2627 DI 10.1063/1.349374 PG 5 WC Physics, Applied SC Physics GA GE658 UT WOS:A1991GE65800017 ER PT J AU DELONG, MC OHLSEN, WD VIOHL, I TAYLOR, PC OLSON, JM AF DELONG, MC OHLSEN, WD VIOHL, I TAYLOR, PC OLSON, JM TI EVIDENCE FOR SPATIALLY INDIRECT RECOMBINATION IN GA0.52IN0.48P SO JOURNAL OF APPLIED PHYSICS LA English DT Article ID VAPOR-PHASE EPITAXY; GROWTH TEMPERATURE; OPTICAL-PROPERTIES; BAND-GAP; GAAS; SUPERLATTICES; GA0.5IN0.5P; PHOTOLUMINESCENCE; HETEROSTRUCTURES; EMISSION AB In previous work we have identified a near-gap photoluminescence in Ga0.52In0.48P which exhibits a strong dependence of emission energy on excitation intensity ("moving emission") and correlated its presence and strength to conditions of growth. In this work we extend our investigations to the rise and decay lifetimes associated with the moving and nonmoving components of the emission. The two processes proceed simultaneously at the same energy. For the moving emission, the time constants scale approximately linearly with excitation intensity. Decaying luminescence can, in most cases, be well fitted with one or two exponentials with time constants as long as milliseconds. The rising luminescence is typically slower and in some cases has a nonmonotonic first time derivative. These results are discussed in terms of existing models of the microstructure of ordered Ga0.52In0.48P. C1 SOLAR ENERGY RES INST,GOLDEN,CO 80401. RP DELONG, MC (reprint author), UNIV UTAH,DEPT PHYS,SALT LAKE CITY,UT 84112, USA. NR 33 TC 92 Z9 98 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 SEP 1 PY 1991 VL 70 IS 5 BP 2780 EP 2787 DI 10.1063/1.349364 PG 8 WC Physics, Applied SC Physics GA GE658 UT WOS:A1991GE65800039 ER PT J AU MILLER, SL SCHWANK, JR NASBY, RD RODGERS, MS AF MILLER, SL SCHWANK, JR NASBY, RD RODGERS, MS TI MODELING FERROELECTRIC CAPACITOR SWITCHING WITH ASYMMETRIC NONPERIODIC INPUT SIGNALS AND ARBITRARY INITIAL CONDITIONS SO JOURNAL OF APPLIED PHYSICS LA English DT Article AB The switching behavior of ferroelectric capacitors experiencing arbitrary time-dependent electric fields and arbitrary initial conditions is investigated both theoretically and experimentally. A general approach for modeling incomplete dipole switching in ferroelectric capacitors is used to derive equations describing the electrical behavior of a simple characterization circuit with arbitrary initial conditions and arbitrary time-dependent applied voltages. The equations include four experimentally determined parameters: the remanent and spontaneous polarizations, the coercive field, and the ferroelectric dielectric constant. Once these model parameters are determined from a single high-frequency sinusoidal hysteresis loop, model predictions are made with no adjustable parameters. The circuit behavior for both sinusoidal and trapezoidal input signals is computed, including asymmetric and nonperiodic signals as well as several different initial conditions. The accuracy of the model predictions is quantitatively verified with experimental data. The approach is also utilized to model the switching behavior of a ferroelectric capacitor containing a sheet of space charge. It is found that hysteresis loop distortions resulting from ionizing radiation resemble those caused by a sheet of space charge. This quantitative modeling capability facilitates the optimization of the design of ferroelectric memory circuits by minimizing the amount of required electrical testing and characterization. It can also be used to facilitate the identification and understanding of degradation mechanisms occurring in ferroelectric thin films. RP MILLER, SL (reprint author), SANDIA NATL LABS,ALBUQUERQUE,NM 87111, USA. NR 7 TC 136 Z9 141 U1 0 U2 22 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 SEP 1 PY 1991 VL 70 IS 5 BP 2849 EP 2860 DI 10.1063/1.349348 PG 12 WC Physics, Applied SC Physics GA GE658 UT WOS:A1991GE65800049 ER PT J AU KONG, Y LEUNG, TC ASOKAKUMAR, P NIELSEN, B LYNN, KG AF KONG, Y LEUNG, TC ASOKAKUMAR, P NIELSEN, B LYNN, KG TI POSITRON MOBILITY IN THERMALLY GROWN SIO2 MEASURED BY DOPPLER BROADENING TECHNIQUE SO JOURNAL OF APPLIED PHYSICS LA English DT Note ID BEAM; TRANSPORT; SURFACES AB The positron mobility in thermally grown SiO2 is deduced from Doppler broadening lineshape data on a metal-oxide-semiconductor sample for positrons implanted into the oxide layer. The fitted mobility is approximately 13(10) X 10(-3) cm2/s V. This value is between that of the electron and hole mobilities in the same system and is two orders of magnitude smaller than the previous estimate from positron measurements. RP KONG, Y (reprint author), BROOKHAVEN NATL LAB,UPTON,NY 11973, USA. RI Nielsen, Bent/B-7353-2009 OI Nielsen, Bent/0000-0001-7016-0040 NR 17 TC 10 Z9 10 U1 0 U2 1 PU AMER INST PHYSICS PI WOODBURY PA CIRCULATION FULFILLMENT DIV, 500 SUNNYSIDE BLVD, WOODBURY, NY 11797-2999 SN 0021-8979 J9 J APPL PHYS JI J. Appl. Phys. PD SEP 1 PY 1991 VL 70 IS 5 BP 2874 EP 2876 DI 10.1063/1.349353 PG 3 WC Physics, Applied SC Physics GA GE658 UT WOS:A1991GE65800054 ER PT J AU CAI, YP AF CAI, YP TI CHARACTERIZATION OF INSERTION-SEQUENCE IS892 AND RELATED ELEMENTS FROM THE CYANOBACTERIUM ANABAENA SP STRAIN PCC-7120 SO JOURNAL OF BACTERIOLOGY LA English DT Article ID INTEGRATION HOST FACTOR; ESCHERICHIA-COLI; NUCLEOTIDE-SEQUENCE; NITROGEN-FIXATION; DNA-SEQUENCE; CODON USAGE; GENE; REARRANGEMENT; BACTERIA; PROTEIN AB IS892, one of the several insertion sequence (IS) elements discovered in Anabaena sp. strain PCC 7120 (Y. Cai and C.P. Wolk, J. Bacteriol. 172:3138-3145, 1990), is 1,675 bp with 24-bp near-perfect inverted terminal repeats and has two open reading frames (ORFs) that could code for proteins of 233 and 137 amino acids. Upon insertion into target sites, this IS generates an 8-bp directly repeated target duplication. A 32-bp sequence in the region between ORF1 and ORF2 is similar to the sequence of the inverted termini. Similar inverted repeats are found within each of those three segments, and the sequences of these repeats bear some similarity to the 11-bp direct repeats flanking the 11-kb insertion interrupting the nifD gene of this strain (J.W. Golden, S.J. Robinson, and R. Haselkorn, Nature [London] 314:419-423, 1985). A sequence similar to that of a binding site for the Escherichia coli integration host factor is found about 120 bp from the left end of IS892. Partial nucleotide sequences of active IS elements IS892N and IS892T, members of the IS892 family from the same Anabaena strain, were shown to be very similar to the sequence of IS892. RP CAI, YP (reprint author), MICHIGAN STATE UNIV,US DOE,PLANT RES LAB,E LANSING,MI 48824, USA. NR 44 TC 18 Z9 18 U1 0 U2 1 PU AMER SOC MICROBIOLOGY PI WASHINGTON PA 1325 MASSACHUSETTS AVENUE, NW, WASHINGTON, DC 20005-4171 SN 0021-9193 J9 J BACTERIOL JI J. Bacteriol. PD SEP PY 1991 VL 173 IS 18 BP 5771 EP 5777 PG 7 WC Microbiology SC Microbiology GA GF098 UT WOS:A1991GF09800024 PM 1653218 ER PT J AU ALAM, J VRBA, JM CAI, YP MARTIN, JA WEISLO, LJ CURTIS, SE AF ALAM, J VRBA, JM CAI, YP MARTIN, JA WEISLO, LJ CURTIS, SE TI CHARACTERIZATION OF THE IS895 FAMILY OF INSERTION SEQUENCES FROM THE CYANOBACTERIUM ANABAENA SP STRAIN PCC-7120 SO JOURNAL OF BACTERIOLOGY LA English DT Article ID DNA; GENE; SITES AB A family of repetitive elements from the cyanobacterium Anabaena sp. strain PCC 7120 was identified through the proximity of one element to the psbAI gene. Four members of this seven-member family were isolated and shown to have structures characteristic of bacterial insertion sequences. Each element is approximately 1,200 bp in length, is delimited by a 30-bp inverted repeat, and contains two open reading frames in tandem on the same DNA strand. The four copies differ from each other by small insertions or deletions, some of which alter the open reading frames. By using a system designed to trap insertion elements, one of the elements, denoted IS895, was shown to be mobile. The target site was not duplicated upon insertion of the element. Two other filamentous cyanobacterial strains were also found to contain sequences homologous to IS895. C1 N CAROLINA STATE UNIV,DEPT GENET,RALEIGH,NC 27695. MICHIGAN STATE UNIV,US DOE,PLANT RES LAB,E LANSING,MI 48824. RI Alam, Jawed/F-2596-2010 OI Alam, Jawed/0000-0001-6520-482X NR 27 TC 20 Z9 20 U1 0 U2 1 PU AMER SOC MICROBIOLOGY PI WASHINGTON PA 1325 MASSACHUSETTS AVENUE, NW, WASHINGTON, DC 20005-4171 SN 0021-9193 J9 J BACTERIOL JI J. Bacteriol. PD SEP PY 1991 VL 173 IS 18 BP 5778 EP 5783 PG 6 WC Microbiology SC Microbiology GA GF098 UT WOS:A1991GF09800025 PM 1653219 ER PT J AU PANDE, CS BASSI, KD JAIN, N DHAR, A GLASS, JD AF PANDE, CS BASSI, KD JAIN, N DHAR, A GLASS, JD TI DIKETOPINIC ACID-A NOVEL REAGENT FOR THE MODIFICATION OF ARGININE SO JOURNAL OF BIOSCIENCES LA English DT Article DE DIKETONE; REVERSIBLE MODIFICATION OF ARGININE RESIDUES; AMINOPOLYMER; DIKETOPOLYMER AB Diketopinic acid has been synthesized and shown to be a reagent of choice for specific, reversible modification of the guanidine groups of arginine residues. Diketopinic acid is a yellow crystalline substance and the carboxyl group of the reagent is a convenient handle for attachment to other molecules. The adducts of diketopinoyl derivatives with the guanidine group are cleaved by 0.2 M o-phenylenediamine at pH 8-9. The modification and regeneration of arginine and of arginyl residues in soyabean trypsin inhibitor and insulin are presented as demonstrations of the use of the reagent. The use of diketopinoyl resin in the separation of oxidized A and B chains of insulin has been discussed. C1 OIL & NAT GAS COMMISS,IRS,AHMEDABAD 380005,INDIA. BROOKHAVEN NATL LAB,MRC,UPTON,NY 11973. RP PANDE, CS (reprint author), HIMACHAL PRADESH UNIV,DEPT CHEM,SIMLA 171005,HIMACHAL PRADES,INDIA. NR 3 TC 1 Z9 1 U1 0 U2 0 PU INDIAN ACADEMY SCIENCES PI BANGALORE PA P B 8005 C V RAMAN AVENUE, BANGALORE 560 080, INDIA SN 0250-5991 J9 J BIOSCIENCE JI J. Biosci. PD SEP PY 1991 VL 16 IS 3 BP 127 EP 135 DI 10.1007/BF02703365 PG 9 WC Biology SC Life Sciences & Biomedicine - Other Topics GA GL931 UT WOS:A1991GL93100005 ER PT J AU SRINIVASAN, S DATYE, AK HAMPDENSMITH, M WACHS, IE DEO, G JEHNG, JM TUREK, AM PEDEN, CHF AF SRINIVASAN, S DATYE, AK HAMPDENSMITH, M WACHS, IE DEO, G JEHNG, JM TUREK, AM PEDEN, CHF TI THE FORMATION OF TITANIUM-OXIDE MONOLAYER COATINGS ON SILICA SURFACES SO JOURNAL OF CATALYSIS LA English DT Article ID RAMAN-SPECTROSCOPY; CATALYSTS; REDUCTION; TIO2 C1 UNIV NEW MEXICO,DEPT CHEM,ALBUQUERQUE,NM 87131. UNIV NEW MEXICO,DEPT CHEM & NUCL ENGN,ALBUQUERQUE,NM 87131. LEHIGH UNIV,DEPT CHEM ENGN,BETHLEHEM,PA 18015. SANDIA NATL LABS,DIV 1846,ALBUQUERQUE,NM 87185. RP SRINIVASAN, S (reprint author), UNIV NEW MEXICO,CTR MICROENGINEERED CERAM,ALBUQUERQUE,NM 87131, USA. RI Deo, Goutam/I-9373-2012; OI Peden, Charles/0000-0001-6754-9928; Datye, Abhaya/0000-0002-7126-8659; Deo, Goutam/0000-0002-0541-8380 NR 18 TC 95 Z9 95 U1 2 U2 8 PU ACADEMIC PRESS INC JNL-COMP SUBSCRIPTIONS PI SAN DIEGO PA 525 B ST, STE 1900, SAN DIEGO, CA 92101-4495 SN 0021-9517 J9 J CATAL JI J. Catal. PD SEP PY 1991 VL 131 IS 1 BP 260 EP 275 DI 10.1016/0021-9517(91)90343-3 PG 16 WC Chemistry, Physical; Engineering, Chemical SC Chemistry; Engineering GA GC356 UT WOS:A1991GC35600025 ER PT J AU GORLLERWALRAND, C FLUYT, L CEULEMANS, A CARNALL, WT AF GORLLERWALRAND, C FLUYT, L CEULEMANS, A CARNALL, WT TI MAGNETIC DIPOLE TRANSITIONS AS STANDARDS FOR JUDD-OFELT PARAMETRIZATION IN LANTHANIDE SPECTRA SO JOURNAL OF CHEMICAL PHYSICS LA English DT Article ID INTENSITY AB It is shown that the sum of the intensities for magnetic dipole transitions between crystal-field components of two free-ion levels in lanthanide spectra is almost independent of the symmetry of the environment. A mean theoretical sum value of 18 x 10(-7) D2, 94 x 10(-7) D2, and 9 x 10(-7) D2 for, respectively, the 5D1 <-- 7F0, 5D0 <-- 7F1, and 5D2 <-- 7F1 dipole strengths has been found. Experimental values of the dipole strength for Eu3+ in different lattices support within reasonable limits the theoretically derived sum rule. We therefore propose to use these magnetic dipole transitions in the Eu3+ spectrum as standards for further Judd-Ofelt parametrization. C1 ARGONNE NATL LAB,ARGONNE,IL 60439. RP GORLLERWALRAND, C (reprint author), UNIV LOUVAIN,DEPT CHEM,CELESTIJNENLAAN 200F,B-3001 HEVERLEE,BELGIUM. NR 20 TC 65 Z9 65 U1 1 U2 12 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 SEP 1 PY 1991 VL 95 IS 5 BP 3099 EP 3106 PG 8 WC Chemistry, Physical; Physics, Atomic, Molecular & Chemical SC Chemistry; Physics GA GD055 UT WOS:A1991GD05500009 ER PT J AU SHARAFEDDIN, OA KOURI, DJ NAYAR, N HOFFMAN, DK AF SHARAFEDDIN, OA KOURI, DJ NAYAR, N HOFFMAN, DK TI QUADRATURE-BASED, COARSE-GRAINED TREATMENT OF THE COORDINATE REPRESENTATION FREE PARTICLE REAL-TIME EVOLUTION OPERATOR SO JOURNAL OF CHEMICAL PHYSICS LA English DT Article ID MONTE-CARLO METHODS; DEPENDENT TREATMENT; PATH INTEGRATION; QUANTUM DYNAMICS; SCATTERING; PROPAGATOR; SYSTEMS AB In this paper we report a quadrature evaluation of the coordinate representation, short-time free particle propagator, . The result is the elimination of most of the highly oscillatory behavior in this quantity yielding in its stead a much smoother function, strongly peaked at R = R'. We view this as a numerical coarse graining of the propagator which leads to the intuitively reasonable result that for short times tau or large mass, the particle should not have a significant amplitude for R points that are far from R'. This leads to an interesting, and potentially useful, banded structure for . Calculations have been carried out both for zero and nonzero orbital angular momenta, for which we also give the exact analytic results, and the same behavior is found. The quadrature-coarse graining procedure still appears to retain the important quantum effects as demonstrated by subsequent use of the coarse-grained free propagator to calculate the scattering of an electron by a simple central potential. Results are in quantitative agreement with those obtained by alternative, numerically exact methods. The coarse-grained free propagator is, of course, independent of the potential, and we expect that it can provide a very useful tool for computing real-time dynamics for a variety of systems. C1 UNIV HOUSTON,DEPT PHYS,HOUSTON,TX 77204. IOWA STATE UNIV SCI & TECHNOL,DEPT CHEM,AMES,IA 50011. IOWA STATE UNIV SCI & TECHNOL,AMES LAB,AMES,IA 50011. RP SHARAFEDDIN, OA (reprint author), UNIV HOUSTON,DEPT CHEM,HOUSTON,TX 77204, USA. NR 36 TC 20 Z9 20 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 SEP 1 PY 1991 VL 95 IS 5 BP 3224 EP 3231 DI 10.1063/1.460879 PG 8 WC Chemistry, Physical; Physics, Atomic, Molecular & Chemical SC Chemistry; Physics GA GD055 UT WOS:A1991GD05500023 ER PT J AU FLESCH, GD NOURBAKHSH, S NG, CY AF FLESCH, GD NOURBAKHSH, S NG, CY TI ABSOLUTE STATE-SELECTED AND STATE-TO-STATE TOTAL CROSS-SECTIONS FOR THE AR+(2P3/2,1/2)+CO REACTIONS SO JOURNAL OF CHEMICAL PHYSICS LA English DT Article ID CHARGE-TRANSFER REACTIONS; LASER-INDUCED FLUORESCENCE; ION-MOLECULE REACTIONS; THERMAL-ENERGY; PHOTO-IONIZATION; TESICO TECHNIQUE; CO; N-2; COLLISIONS; AR+ AB Absolute spin-orbit state-selected total cross sections for the reactions, Ar+ (2P3/2,1/2) + CO --> CO+ + Ar [reaction (1)], C+ + O + Ar [reaction (2)], O+ + C + Ar [reaction (3)], and ArC+ + O [reaction (4)], have been measured in the center-of-mass collision energy (E(c.m.)) range of 0.04-123.5 eV. Absolute spin-orbit state transition total cross sections for the Ar+ (2P3/2,1/2) + CO reactions at E(c.m.) have also been obtained. The appearance energies (AE) for C+ (E(c.m.) = 6.6 +/- 0.4 eV) and O+ (E(c.m.) = 8.6 +/- 0.4 eV) are in agreement with the thermochemical thresholds for reactions (2) and (3), respectively. The observed AE for reaction (4) yields a lower bound of 0.5 eV for the ArC+ bond dissociation energy. The kinetic energy dependence of the absolute cross sections and the retarding potential analysis of the product ions support that ArC+, C+, and O+ are formed via a charge transfer predissociation mechanism, similar to that proposed to be responsible for the formation of O+ (N+) and ArO+ (ArN+) in the collisions of Ar+ (2P3/2,1/2) + O2(N2). C1 IOWA STATE UNIV SCI & TECHNOL,DEPT CHEM,AMES,IA 50011. RP FLESCH, GD (reprint author), IOWA STATE UNIV SCI & TECHNOL,US DOE,AMES LAB,AMES,IA 50011, USA. NR 36 TC 20 Z9 20 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 SEP 1 PY 1991 VL 95 IS 5 BP 3381 EP 3386 DI 10.1063/1.460843 PG 6 WC Chemistry, Physical; Physics, Atomic, Molecular & Chemical SC Chemistry; Physics GA GD055 UT WOS:A1991GD05500039 ER PT J AU SMITH, DH LIM, KH FERER, M AF SMITH, DH LIM, KH FERER, M TI CRITICAL-SCALING THEORY FOR TERNARY-SYSTEMS WITH POLAR TIELINES SO JOURNAL OF CHEMICAL PHYSICS LA English DT Article ID MULTICOMPONENT SYSTEMS; CRITICAL-POINTS AB As used in the previous literature, critical-scaling theory for ternary (or pseudoternary) systems requires that the tielines be parallel, i.e., that one of the concentrations appears to be a field variable, rather than a density variable as it is known to be. However, for many chemical systems, the tielines in the conventional weight-fraction phase diagram are not parallel; instead, extensions of the tielines radiate from a single point (or are assumed to do so). For such cases, we show that there are two coordinate transforms (one to polar coordinates, the other to a second set of triangular coordinates) that convert one of the compositions from a density variable to a "hidden variable." The latter transformation makes the tielines parallel. An association model that produces such parallel tielines is discussed, and the ability of critical-scaling equations to describe conjugate phase compositions in the system of transformed triangular coordinates is examined for a real ternary system, ethanol/n-hexane/water. C1 W VIRGINIA UNIV,DEPT PHYS,MORGANTOWN,WV 26506. RP SMITH, DH (reprint author), US DOE,MORGANTOWN ENERGY TECHNOL CTR,MORGANTOWN,WV 26507, USA. NR 13 TC 5 Z9 5 U1 0 U2 0 PU AMER INST PHYSICS PI WOODBURY PA CIRCULATION FULFILLMENT DIV, 500 SUNNYSIDE BLVD, WOODBURY, NY 11797-2999 SN 0021-9606 J9 J CHEM PHYS JI J. Chem. Phys. PD SEP 1 PY 1991 VL 95 IS 5 BP 3649 EP 3656 DI 10.1063/1.460816 PG 8 WC Chemistry, Physical; Physics, Atomic, Molecular & Chemical SC Chemistry; Physics GA GD055 UT WOS:A1991GD05500066 ER PT J AU BROWN, JK LUNTZ, AC SCHULTZ, PA AF BROWN, JK LUNTZ, AC SCHULTZ, PA TI LONG-RANGE POISONING OF D2 DISSOCIATIVE CHEMISORPTION ON PT(111) BY COADSORBED-K SO JOURNAL OF CHEMICAL PHYSICS LA English DT Article ID METAL-SURFACES; TRANSITION-METALS; ADSORPTION; POTASSIUM; CO; H-2; HYDROGEN; COADSORPTION; DESORPTION; CATALYSIS AB We report detailed molecular beam studies of the effects of K adsorption on the dissociative chemisorption probabilities S0 for D2 on Pt(111). In contrast to conventional wisdom for many other molecular systems, we find that K is a very strong poison rather than promoter for H2 dissociation. S0 decreases roughly exponentially with K coverage THETA-K. The effective cross section for poisoning per adsorbed K varies between 70 and 430 angstrom 2, depending upon incident energy E(i). This suggests that an extremely long-range electronic perturbation is responsible for the poisoning. A theoretical model is developed to describe these sticking measurements. It is based on the fact that the adsorbed K lowers the work function of the surface. This enhances Pauli repulsion for the molecule-surface interaction which, in turn, increases the barrier to dissociation. When the model is generalized to include inhomogeneous effects through a local work function, excellent agreement is obtained between the model and experiments. This model also naturally accounts for the increased associative desorption temperatures for H2 when coadsorbed K is present. C1 SANDIA NATL LABS,ALBUQUERQUE,NM 87185. RP BROWN, JK (reprint author), IBM CORP,ALMADEN RES CTR,SAN JOSE,CA 95120, USA. NR 38 TC 55 Z9 55 U1 1 U2 7 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 SEP 1 PY 1991 VL 95 IS 5 BP 3767 EP 3774 DI 10.1063/1.460827 PG 8 WC Chemistry, Physical; Physics, Atomic, Molecular & Chemical SC Chemistry; Physics GA GD055 UT WOS:A1991GD05500079 ER PT J AU OBER, BA JAGUST, WJ KOSS, E DELIS, DC FRIEDLAND, RP AF OBER, BA JAGUST, WJ KOSS, E DELIS, DC FRIEDLAND, RP TI VISUOCONSTRUCTIVE PERFORMANCE AND REGIONAL CEREBRAL GLUCOSE-METABOLISM IN ALZHEIMERS-DISEASE SO JOURNAL OF CLINICAL AND EXPERIMENTAL NEUROPSYCHOLOGY LA English DT Article ID POSITRON EMISSION TOMOGRAPHY; ANTERIOR-POSTERIOR; SENILE DEMENTIA; BRAIN; ASYMMETRIES; LESIONS AB The drawings of Alzheimer's disease (AD) patients and elderly control subjects were rated on a number of specific performance scales, such as attention to configuration, attention to detail, and stimulus boundedness. AD patients showed significantly poorer performance than controls on most drawing scales, and the drawing measures were differentially affected by disease severity. Regional cerebral glucose metabolism (rCMRglc) was assessed via positron emission tomography (PET, with 18FDG) in a subgroup of the AD patients. Partial correlations of rCMRglc with drawing measures (age, sex, and education served as control variables) were conducted. Five out of eight of the drawing measures were significantly correlated (p < .005) with rCMRglc in occipital and/or temporal-parietal regions, for both left and right hemispheres. Only one of the eight drawing measures, attention to detail, was significantly correlated with rCMRglc in both frontal and posterior regions of interest, again for both hemispheres. Overall dementia severity showed no significant correlations with rCMRglc in any of the regions. These findings are suggestive of a posterior-anterior differentiation, but no left-right hemisphere differentiation, in the relationship between drawing performance and cerebral metabolism in AD, which cannot be accounted for by overall dementia severity. Differences between the drawing performance of AD and unilateral brain damaged patients are discussed, and further applications of the rating scales (provided in the Appendix) are suggested. C1 UNIV CALIF DAVIS,DEPT APPL BEHAV SCI,DAVIS,CA 95616. UNIV CALIF DAVIS,DEPT NEUROL,DAVIS,CA 95616. UNIV CALIF BERKELEY LAWRENCE BERKELEY LAB,DONNER LAB,BERKELEY,CA 94720. UNIV CALIF SAN DIEGO,DEPT PSYCHIAT,LA JOLLA,CA 92093. DEPT VET AFFAIRS MED CTR,SAN DIEGO,CA. RP OBER, BA (reprint author), DEPT VET AFFAIRS MED CTR,RES SERV 151,150 MUIR RD,MARTINEZ,CA 94553, USA. RI Friedland, Robert/A-2834-2010 OI Friedland, Robert/0000-0001-5721-1843 FU NIA NIH HHS [AG05890, AG07793] NR 43 TC 50 Z9 50 U1 0 U2 2 PU SWETS ZEITLINGER PUBLISHERS PI LISSE PA P O BOX 825, 2160 SZ LISSE, NETHERLANDS SN 1380-3395 J9 J CLIN EXP NEUROPSYC JI J. Clin. Exp. Neuropsychol. PD SEP PY 1991 VL 13 IS 5 BP 752 EP 772 DI 10.1080/01688639108401088 PG 21 WC Psychology, Clinical; Clinical Neurology; Psychology SC Psychology; Neurosciences & Neurology GA GK476 UT WOS:A1991GK47600010 PM 1955530 ER PT J AU FRIEDMAN, A PARKER, SE RAY, SL BIRDSALL, CK AF FRIEDMAN, A PARKER, SE RAY, SL BIRDSALL, CK TI MULTISCALE PARTICLE-IN-CELL PLASMA SIMULATION SO JOURNAL OF COMPUTATIONAL PHYSICS LA English DT Article ID IMPLICIT C1 UNIV CALIF BERKELEY,ELECTR RES LAB,BERKELEY,CA 94720. RP FRIEDMAN, A (reprint author), UNIV CALIF LAWRENCE LIVERMORE NATL LAB,LIVERMORE,CA 94550, USA. NR 18 TC 23 Z9 26 U1 1 U2 9 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 SEP PY 1991 VL 96 IS 1 BP 54 EP 70 DI 10.1016/0021-9991(91)90265-M PG 17 WC Computer Science, Interdisciplinary Applications; Physics, Mathematical SC Computer Science; Physics GA GA366 UT WOS:A1991GA36600003 ER PT J AU HIRSHMAN, SP BETANCOURT, O AF HIRSHMAN, SP BETANCOURT, O TI PRECONDITIONED DESCENT ALGORITHM FOR RAPID CALCULATIONS OF MAGNETOHYDRODYNAMIC EQUILIBRIA SO JOURNAL OF COMPUTATIONAL PHYSICS LA English DT Article C1 CUNY,CITY COLL,NEW YORK,NY 10038. RP HIRSHMAN, SP (reprint author), OAK RIDGE NATL LAB,OAK RIDGE,TN 37831, USA. NR 11 TC 139 Z9 140 U1 1 U2 5 PU ACADEMIC PRESS INC JNL-COMP SUBSCRIPTIONS PI SAN DIEGO PA 525 B ST, STE 1900, SAN DIEGO, CA 92101-4495 SN 0021-9991 J9 J COMPUT PHYS JI J. Comput. Phys. PD SEP PY 1991 VL 96 IS 1 BP 99 EP 109 DI 10.1016/0021-9991(91)90267-O PG 11 WC Computer Science, Interdisciplinary Applications; Physics, Mathematical SC Computer Science; Physics GA GA366 UT WOS:A1991GA36600005 ER PT J AU POINTON, TD AF POINTON, TD TI SLANTED CONDUCTING BOUNDARIES AND FIELD-EMISSION OF PARTICLES IN AN ELECTROMAGNETIC PARTICLE SIMULATION CODE SO JOURNAL OF COMPUTATIONAL PHYSICS LA English DT Article ID DIODE RP POINTON, TD (reprint author), SANDIA NATL LABS,ALBUQUERQUE,NM 87185, USA. NR 13 TC 24 Z9 25 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 SEP PY 1991 VL 96 IS 1 BP 143 EP 162 DI 10.1016/0021-9991(91)90269-Q PG 20 WC Computer Science, Interdisciplinary Applications; Physics, Mathematical SC Computer Science; Physics GA GA366 UT WOS:A1991GA36600007 ER PT J AU BRACKBILL, JU AF BRACKBILL, JU TI FLIP MHD - A PARTICLE-IN-CELL METHOD FOR MAGNETOHYDRODYNAMICS SO JOURNAL OF COMPUTATIONAL PHYSICS LA English DT Article RP BRACKBILL, JU (reprint author), UNIV CALIF LOS ALAMOS SCI LAB,LOS ALAMOS,NM 87545, USA. NR 24 TC 51 Z9 51 U1 0 U2 2 PU ACADEMIC PRESS INC JNL-COMP SUBSCRIPTIONS PI SAN DIEGO PA 525 B ST, STE 1900, SAN DIEGO, CA 92101-4495 SN 0021-9991 J9 J COMPUT PHYS JI J. Comput. Phys. PD SEP PY 1991 VL 96 IS 1 BP 163 EP 192 DI 10.1016/0021-9991(91)90270-U PG 30 WC Computer Science, Interdisciplinary Applications; Physics, Mathematical SC Computer Science; Physics GA GA366 UT WOS:A1991GA36600008 ER PT J AU DEYOREO, JJ ATHERTON, LJ ROBERTS, DH AF DEYOREO, JJ ATHERTON, LJ ROBERTS, DH TI ELIMINATION OF SCATTERING CENTERS FROM CR-LICAALF6 SO JOURNAL OF CRYSTAL GROWTH LA English DT Article ID LICAALF6-CR-3+ AB We describe the morphology of micron-sized defects present in all samples of the the laser crystal Cr3+:LiCaAIF6 (LiCAF). We further describe the results of a set of annealing experiments which demonstrate that annealing within 50-degrees-C of the melting point eliminates these defects and reduces passive scattering losses in the crystal by an order of magnitude. We present evidence which shows that during annealing, these defects dissolve into the matrix and then diffuse out of the crystal. We estimate that the diffusion constant for the atomically dispersed defect species is on the order of 10(-7) cm2/s. Finally, we hypothesize a mechanism for the growth and elimination of defects in LiCAF. RP DEYOREO, JJ (reprint author), UNIV CALIF LAWRENCE LIVERMORE NATL LAB,LIVERMORE,CA 94550, USA. 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 0022-0248 J9 J CRYST GROWTH JI J. Cryst. Growth PD SEP PY 1991 VL 113 IS 3-4 BP 691 EP 697 DI 10.1016/0022-0248(91)90106-F PG 7 WC Crystallography; Materials Science, Multidisciplinary; Physics, Applied SC Crystallography; Materials Science; Physics GA GM356 UT WOS:A1991GM35600040 ER PT J AU NEFEDOV, VI FADLEY, CS AF NEFEDOV, VI FADLEY, CS TI MEISEL,ARMIN SO JOURNAL OF ELECTRON SPECTROSCOPY AND RELATED PHENOMENA LA English DT Item About an Individual C1 UNIV CALIF DAVIS,DAVIS,CA 95616. UNIV CALIF BERKELEY LAWRENCE BERKELEY LAB,BERKELEY,CA 94720. RP NEFEDOV, VI (reprint author), ACAD SCI USSR,INST GEN & INORGAN CHEM,MOSCOW 117907,USSR. NR 0 TC 0 Z9 0 U1 0 U2 0 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0368-2048 J9 J ELECTRON SPECTROSC JI J. Electron Spectrosc. Relat. Phenom. PD SEP PY 1991 VL 57 IS 1 BP R7 EP R8 PG 2 WC Spectroscopy SC Spectroscopy GA GH877 UT WOS:A1991GH87700001 ER PT J AU ASHBY, CIH MYERS, DR AF ASHBY, CIH MYERS, DR TI SELECTIVE PHOTOCHEMICAL ETCHING BY ENHANCED CARRIER RECOMBINATION - PROCESS-CONTROL USING RAMAN-SPECTROSCOPY SO JOURNAL OF ELECTRONIC MATERIALS LA English DT Article DE SELECTIVE ETCHING; PHOTOCHEMICAL ETCHING; GAAS; OPTICAL DIAGNOSTICS; RAMAN SPECTROSCOPY ID GAAS AB Carrier-driven photochemical reactions, which require direct participation of free carriers for the chemical reaction to proceed, can be selectively suppressed by increasing the carrier recombination rate through the creation of defects using ion implantation. The post-implantation residual defect concentration determined from changes in the Raman LO-phonon lineshape correlates well with the degree of etching suppression and is a better predictor of etching behavior than defect concentrations calculated with the Monte Carlo code, TRIM. Raman spectroscopy may be a useful pre-etch diagnostic to determine the degree of etching suppression expected following a given implantation treatment. RP ASHBY, CIH (reprint author), SANDIA NATL LABS,ALBUQUERQUE,NM 87185, USA. NR 12 TC 1 Z9 1 U1 0 U2 1 PU MINERALS METALS MATERIALS SOC PI WARRENDALE PA 420 COMMONWEALTH DR, WARRENDALE, PA 15086 SN 0361-5235 J9 J ELECTRON MATER JI J. Electron. Mater. PD SEP PY 1991 VL 20 IS 9 BP 695 EP 699 DI 10.1007/BF02654541 PG 5 WC Engineering, Electrical & Electronic; Materials Science, Multidisciplinary; Physics, Applied SC Engineering; Materials Science; Physics GA GE240 UT WOS:A1991GE24000010 ER PT J AU HSUEH, CH AF HSUEH, CH TI TOUGHENING BEHAVIOR AND INTERFACIAL PROPERTIES OF FIBER-REINFORCED CERAMIC COMPOSITES SO JOURNAL OF ENERGY RESOURCES TECHNOLOGY-TRANSACTIONS OF THE ASME LA English DT Article AB Toughening of ceramics by incorporating strong fibers has become an established technology, resulting in the creation of a new generation of tough ceramic composites. This toughening effect is primarily due to bridging of the crack surfaces by intact fibers when the composite is subjected to tension. The fiber bridging mechanisms, which are contingent upon the stress transfer phenomena between the fiber and the matrix, are reviewed in this paper. The critical role of the properties at the fiber/matrix interface in controlling the stress transfer phenomena is examined. Finally, evaluations of the interfacial properties of the composite by the indentation technique and the corresponding analysis are presented. RP HSUEH, CH (reprint author), OAK RIDGE NATL LAB,DIV MET & CERAM,OAK RIDGE,TN 37831, USA. RI Hsueh, Chun-Hway/G-1345-2011 NR 0 TC 0 Z9 0 U1 1 U2 2 PU ASME-AMER SOC MECHANICAL ENG PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 SN 0195-0738 J9 J ENERG RESOUR-ASME JI J. Energy Resour. Technol.-Trans. ASME PD SEP PY 1991 VL 113 IS 3 BP 197 EP 203 DI 10.1115/1.2905805 PG 7 WC Energy & Fuels SC Energy & Fuels GA HP691 UT WOS:A1991HP69100012 ER PT J AU HOPPER, RW AF HOPPER, RW TI PLANE STOKES-FLOW DRIVEN BY CAPILLARITY ON A FREE-SURFACE .2. FURTHER DEVELOPMENTS SO JOURNAL OF FLUID MECHANICS LA English DT Article AB For the free creeping viscous incompressible plane flow of a finite region, bounded by a simple smooth closed curve and driven solely by surface tension, analyzed previously, the shape evolution was described in terms of a time-dependent mapping function z = OMEGA(zeta, t) of the unit circle, conformal on \zeta\ less-than-or-equal-to 1. An equation giving the time evolution of the map, typically in parametric form, was derived. In this article, the flow of the infinite region exterior to a hypotrochoid is given. This includes the elliptic hole, which shrinks at a constant rate with a constant aspect ratio. The theory is extended to a class of semi-infinite regions, mapped from Im zeta less-than-or-equal-to 0, and used to solve the flow in a half-space bounded by a certain groove. The depth of the groove ultimately decays inversely with time. RP HOPPER, RW (reprint author), UNIV CALIF LAWRENCE LIVERMORE NATL LAB,DEPT CHEM & MAT SCI,LIVERMORE,CA 94550, USA. NR 7 TC 37 Z9 38 U1 1 U2 4 PU CAMBRIDGE UNIV PRESS PI NEW YORK PA 40 WEST 20TH STREET, NEW YORK, NY 10011-4211 SN 0022-1120 J9 J FLUID MECH JI J. Fluid Mech. PD SEP PY 1991 VL 230 BP 355 EP 364 DI 10.1017/S0022112091000824 PG 10 WC Mechanics; Physics, Fluids & Plasmas SC Mechanics; Physics GA GH088 UT WOS:A1991GH08800014 ER PT J AU HEDRICK, DB RICHARDS, B JEWELL, W GUCKERT, JB WHITE, DC AF HEDRICK, DB RICHARDS, B JEWELL, W GUCKERT, JB WHITE, DC TI DISTURBANCE, STARVATION, AND OVERFEEDING STRESSES DETECTED BY MICROBIAL LIPID BIOMARKERS IN HIGH-SOLIDS HIGH-YIELD METHANOGENIC REACTORS SO JOURNAL OF INDUSTRIAL MICROBIOLOGY LA English DT Article DE FATTY ACID; ETHER LIPID; METHANOGEN; CLUSTERING METHOD; MICROBIAL STRESS ID SEDIMENTS; ARCHAEBACTERIA; COMMUNITY; BIOMASS AB Microbial biomass and community structure of methanogenic anaerobic biomass reactors can be quantitatively monitored by signature lipid analysis. The eubacterial and eukaryotic polar lipid fatty acids and the methanogen polar lipid ethers are reliable measures of their respective biomasses. The pattern of polar lipid fatty acids yields information on the community structure and metabolic state of the eubacteria and eukaryotes. These biomarker methods were applied over a 2-day feeding cycle of a highly productive batch-fed high-solids anaerobic biomass reactor. It was sampled before feeding, 6 h after feeding (disturbed), at maximum gas production (healthy, 24 h), and after feedstock utilization (starved, 48 h). Relative to the healthy condition, the disturbance of feeding significantly decreased eubacterial biomass and the proportion of unsaturated fatty acids, and increased branched fatty acids and the eubacterial stress biomarker, trans/cis 16:1-omega-7. The starved condition was not significantly different from the healthy in biomass or proportions of fatty acids, but did show a significant increase in the proportion of the eubacterial stress biomarker trans/cis 18:1-omega-7. This reactor was compared to a second of the same design which had been overfed and showed significantly less productivity. The overfed reactor had a significantly lower methanogenic biomass, iso-branched fatty acids, and higher eubacterial stress markers Cy17:0 and trans/cis 18:1-omega-7 than the highly productive reactor. C1 UNIV TENNESSEE,DEPT MICROBIOL,KNOXVILLE,TN 37996. OAK RIDGE NATL LAB,DIV ENVIRONM SCI,OAK RIDGE,TN. CORNELL UNIV,DEPT AGR & BIOL ENGN,ITHACA,NY 14853. RP HEDRICK, DB (reprint author), UNIV TENNESSEE,INST APPL MICROBIOL,KNOXVILLE,TN 37932, USA. RI Richards, Brian/J-4765-2012 NR 26 TC 17 Z9 17 U1 0 U2 0 PU STOCKTON PRESS PI BASINGSTOKE PA HOUNDMILLS, BASINGSTOKE, HAMPSHIRE, ENGLAND RG21 6XS SN 0169-4146 J9 J IND MICROBIOL JI J. Indust. Microbiol. PD SEP PY 1991 VL 8 IS 2 BP 91 EP 98 DI 10.1007/BF01578759 PG 8 WC Biotechnology & Applied Microbiology SC Biotechnology & Applied Microbiology GA GH098 UT WOS:A1991GH09800003 ER PT J AU PETTERSON, BJ ROBINETT, RD AF PETTERSON, BJ ROBINETT, RD TI MODEL-BASED DAMPING OF COUPLED HORIZONTAL AND VERTICAL OSCILLATIONS IN A FLEXIBLE ROD SO JOURNAL OF INTELLIGENT & ROBOTIC SYSTEMS LA English DT Article DE CONTROL STRATEGY; DAMPING; OSCILLATION; VIBRATION SUPPRESSION AB This paper reviews the theory associated with vibrations of angularly accelerated cantilevered beams which display significant gravitational sag (coupling the out-of-plane dynamics of the flexible beam) and formulates a control approach for moving such beams to damp residual first horizontal and vertical modes of oscillation. An experimental implementation of the control strategy using an open-loop, single axis torque that is shaped for simultaneous damping of the horizontal and vertical vibrations is described. The experimental control strategy demonstrates more than a 90% reduction in the coupled residual vibrations. RP PETTERSON, BJ (reprint author), SANDIA NATL LABS,ALBUQUERQUE,NM 87185, USA. NR 9 TC 4 Z9 4 U1 1 U2 2 PU KLUWER ACADEMIC PUBL PI DORDRECHT PA SPUIBOULEVARD 50, PO BOX 17, 3300 AA DORDRECHT, NETHERLANDS SN 0921-0296 J9 J INTELL ROBOT SYST JI J. Intell. Robot. Syst. PD SEP PY 1991 VL 4 IS 3 BP 285 EP 299 DI 10.1007/BF00303228 PG 15 WC Computer Science, Artificial Intelligence; Robotics SC Computer Science; Robotics GA GE153 UT WOS:A1991GE15300005 ER PT J AU MOORE, JD ELSTON, RA DRUM, AS WILKINSON, MT AF MOORE, JD ELSTON, RA DRUM, AS WILKINSON, MT TI ALTERNATE PATHOGENESIS OF SYSTEMIC NEOPLASIA IN THE BIVALVE MOLLUSK MYTILUS SO JOURNAL OF INVERTEBRATE PATHOLOGY LA English DT Article DE NEOPLASIA; CANCER; MYTILUS; BIVALVE; MOLLUSK; FLOW CYTOMETRY; POLYPLOID; CELL CYCLE; PROLIFERATION RATE ID SOFT-SHELL CLAM; FLOW-CYTOMETRY; MYA-ARENARIA; HEMATOPOIETIC NEOPLASIA; HEMIC NEOPLASIA; CELL-CYCLE; EDULIS; LEUKEMIA; CANCER; BAY RP MOORE, JD (reprint author), BATTELLE MARINE SCI LAB, 439 W SEQUIM BAY RD, SEQUIM, WA 98382 USA. FU NCI NIH HHS [5 RO1 CA 44269-02] NR 28 TC 41 Z9 41 U1 1 U2 5 PU ACADEMIC PRESS INC ELSEVIER SCIENCE PI SAN DIEGO PA 525 B ST, STE 1900, SAN DIEGO, CA 92101-4495 USA SN 0022-2011 EI 1096-0805 J9 J INVERTEBR PATHOL JI J. Invertebr. Pathol. PD SEP PY 1991 VL 58 IS 2 BP 231 EP 243 DI 10.1016/0022-2011(91)90067-Z PG 13 WC Zoology SC Zoology GA GE051 UT WOS:A1991GE05100010 PM 1783779 ER PT J AU PAYNE, SA WILKE, GD AF PAYNE, SA WILKE, GD TI TRANSIENT GRATINGS BY 4F-]5D EXCITATION OF RARE-EARTH IMPURITIES IN SOLIDS SO JOURNAL OF LUMINESCENCE LA English DT Article ID DIFFUSION MEASUREMENTS; PHASE CONJUGATION; REFRACTIVE-INDEX; SINGLE-CRYSTALS; ABSORBING MEDIA; DOPED GLASSES; ND-3+ IONS; 4-WAVE; ABSORPTION; SPECTROSCOPY AB We have generated transient population gratings in CaF2:Eu2+ and LiYF4:Nd3+ by utilizing 355 nm excitation from a pulsed laser source. The scattering from the gratings was observed with the aid of a helium-neon laser operating at 632.8 nm. The grating is the result of a 4f --> 5d excitation mechanism for both crystals. For the case of CaF2:Eu2+, the grating is absorptive in origin, and is due to the excitation of the 4f7 --> 4f65d transition by the crossed pump beams. A unique situation is encountered for the LiYF4:Nd3+ system, in which the gratings is created via a two-step two-photon excitation process, described by the transition sequence: 4I9/2(4f3) --> 4D3/2(4f3) --> 4f25d. Following excitation into the 4f2(5)d manifold, a portion of the Nd3+ ions rapidly relax into the high-lying 2G9/2(4f3) state. The grating arises from the difference in the optical properties of the 2G9/2 and 4I9/2 states. RP PAYNE, SA (reprint author), UNIV CALIF LAWRENCE LIVERMORE NATL LAB,POB 5508,L-490,LIVERMORE,CA 94550, USA. NR 40 TC 9 Z9 9 U1 1 U2 4 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0022-2313 J9 J LUMIN JI J. Lumines. PD SEP PY 1991 VL 50 IS 3 BP 159 EP 168 DI 10.1016/0022-2313(91)90039-X PG 10 WC Optics SC Optics GA GF891 UT WOS:A1991GF89100003 ER PT J AU WU, RQ LI, C FREEMAN, AJ AF WU, RQ LI, C FREEMAN, AJ TI STRUCTURAL, ELECTRONIC AND MAGNETIC-PROPERTIES OF CO/PD(111) AND CO/PT(111) SO JOURNAL OF MAGNETISM AND MAGNETIC MATERIALS LA English DT Article ID FILM LAYERED STRUCTURES; SURFACE MAGNETISM; SPIN ANISOTROPY; ULTRATHIN FILMS; FE MONOLAYERS; WORK FUNCTION; EXCHANGE; COBALT; MULTILAYERS; TRANSITION AB The structural, electronic and magnetic (including magnetic anisotropy) properties of the Co/Pd(111) and Co/Pt(111) systems were investigated using the local density total energy full potential linearized augmented plane wave (FLAPW) method. Structurally, the pseudomorphic Co overlayer occupies the fcc sites on the substrates, with a 5-6% contraction of nearest Co-Pd and Co-Pt distances. As results of a second variation magnetic anisotropy calculation, Co/Pt(111) shows strong perpendicular spin orientation (with an anisotropy energy approximately 4.5 X 10(-4) eV/adatom). Strong covalent overlayer/substrate bonding results in large adsorption energies of 2.2-2.5 eV/adatom. Unlike other magnetic/nonmagnetic adsorption systems, Co atoms retain (or even enhance) their local magnetic moment as in the free-standing Co monolayer. The Co overlayer induces a long-range (beyond 3 atomic layers) spin polarization in Pd(111), but a relatively shorter-range disturbance in Pt(111). C1 ARGONNE NATL LAB, DIV MAT SCI, ARGONNE, IL 60439 USA. RP WU, RQ (reprint author), NORTHWESTERN UNIV, DEPT PHYS & ASTRON, EVANSTON, IL 60208 USA. RI Wu, Ruqian/C-1395-2013 OI Wu, Ruqian/0000-0002-6156-7874 NR 71 TC 93 Z9 93 U1 4 U2 27 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0304-8853 EI 1873-4766 J9 J MAGN MAGN MATER JI J. Magn. Magn. Mater. PD SEP PY 1991 VL 99 IS 1-3 BP 71 EP 80 DI 10.1016/0304-8853(91)90048-F PG 10 WC Materials Science, Multidisciplinary; Physics, Condensed Matter SC Materials Science; Physics GA GM570 UT WOS:A1991GM57000010 ER PT J AU DELONG, LE HUBER, JG BEDELL, KS AF DELONG, LE HUBER, JG BEDELL, KS TI CRITERIA FOR THE OCCURRENCE OF FERROMAGNETISM AND WEAK MAGNETIC ORDER IN NARROW-BAND METALS SO JOURNAL OF MAGNETISM AND MAGNETIC MATERIALS LA English DT Article ID HEAVY-FERMION SYSTEMS; RENORMALIZATION-GROUP APPROACH; ANDERSON MODEL; PHENOMENOLOGICAL TRENDS; RARE-EARTH; HYDROSTATIC-PRESSURE; SPIN FLUCTUATIONS; STATIC PROPERTIES; ELECTRON-SYSTEMS; SUPERCONDUCTIVITY AB Phenomenological correlations between the occurrence of different types of magnetic order, the value of the electronic specific heat divided by temperature gamma*, and the shortest distance d between Ce and U atoms in a number of metallic compounds are presented. Ferromagnetism is found to occur over restricted ranges of d and gamma*, and the magnetic ordering temperature T(m) and the ordered moment mu-or are maximized for d almost-equal-to 4.0-4.2 angstrom. "Weak magnetic order", for which mu-or << 0.5-mu-B, is found to occur in two distinct regimes: Large values of T(m) occur for d less than the "Hill limits" d(H) almost-equal-to 3.4 angstrom (Ce) and 3.5 angstrom (U), with gamma* almost-equal-to 3.5 X 10(4) erg cm-3K-2, while very low T(m) are found in several heavy fermion compounds near d almost-equal-to 4.15 angstrom and gamma* almost-equal-to 1 x 10(5) erg cm-3K-2. A plot of T(m) vs. volume-scaled mu-or implies that metallic 4f, 5f and 3d transition metal materials can be systematically described within a unified picture. The small exchange enhancement of the magnetic susceptibility of heavy fermion compounds and the surprising trend that ferromagnetism occurs in relatively strongly hybridized systems may be explained by the wavevector dependence of the electronic self-energy that is responsible for large effective mass. C1 UNIV CALIF LOS ALAMOS SCI LAB,T-11,MS-3262,LOS ALAMOS,NM 87545. RP DELONG, LE (reprint author), UNIV KENTUCKY,DEPT PHYS & ASTRON,LEXINGTON,KY 40506, USA. NR 76 TC 18 Z9 18 U1 2 U2 2 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0304-8853 J9 J MAGN MAGN MATER JI J. Magn. Magn. Mater. PD SEP PY 1991 VL 99 IS 1-3 BP 171 EP 189 DI 10.1016/0304-8853(91)90061-E PG 19 WC Materials Science, Multidisciplinary; Physics, Condensed Matter SC Materials Science; Physics GA GM570 UT WOS:A1991GM57000023 ER PT J AU HUANG, YY FELCHER, GP PARKIN, SSP AF HUANG, YY FELCHER, GP PARKIN, SSP TI ANTIFERROMAGNETIC AND FERROMAGNETIC ORDER IN CO/RU MULTILAYERS SO JOURNAL OF MAGNETISM AND MAGNETIC MATERIALS LA English DT Letter ID LAYERED MAGNETIC-STRUCTURES; GIANT MAGNETORESISTANCE; INTERLAYER EXCHANGE; SUPERLATTICES; FE/CR AB The magnetic order of several polycrystalline cobalt-ruthenium multilayers was determined by polarized neutron reflectometry. Measurements were made on four samples comprised of nominally 30 angstrom thick Co layers separated by Ru layers nominally 6.6, 11, 17.6 and 22 angstrom thick respectively. These studies confirm that adjacent cobalt layers, in themselves ferromagnetic, couple alternatively antiferro- and ferromagnetically when the ruthenium thickness is increased. In addition, neutron scattering at grazing incidence reveals that the lateral extension of the antiferromagnetic domains is limited, and does not exceed a few thousand angstroms. In the predominantly ferromagnetically coupled multilayers evidence for a tiny portion of AF coupled regions is found. C1 IBM CORP,DIV RES,ALMADEN RES CTR,SAN JOSE,CA 95120. RP HUANG, YY (reprint author), ARGONNE NATL LAB,DIV MAT SCI,ARGONNE,IL 60439, USA. RI Parkin, Stuart/D-2521-2012 NR 14 TC 32 Z9 32 U1 0 U2 10 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0304-8853 J9 J MAGN MAGN MATER JI J. Magn. Magn. Mater. PD SEP PY 1991 VL 99 IS 1-3 BP L31 EP L38 DI 10.1016/0304-8853(91)90044-B PG 8 WC Materials Science, Multidisciplinary; Physics, Condensed Matter SC Materials Science; Physics GA GM570 UT WOS:A1991GM57000006 ER PT J AU BROWN, IG DICKINSON, MR GALVIN, JE GODECHOT, X MACGILL, RA AF BROWN, IG DICKINSON, MR GALVIN, JE GODECHOT, X MACGILL, RA TI SOME NOVEL SURFACE MODIFICATION APPLICATIONS OF A NEW KIND OF HIGH-CURRENT METAL-ION IMPLANTATION FACILITY SO JOURNAL OF MATERIALS ENGINEERING LA English DT Article AB A novel high current metal ion implantation facility has been developed in which a metal vapor vacuum arc ion source is used. The source is operated in a pulsed mode, with pulse width 0.25 msec and repetition rate up to 100 pps. Beam extraction voltage is up to 100 kV and beam current up to several amperes peak and 10-20 mA time averaged delivered onto target. Implantation is done in a broad beam mode with a direct line of sight from ion source to target. Virtually all of the solid metals of the Periodic Table can be used. The facility has been used for a variety of different research applications, including metallurgical surface modification, high temperature oxidation resistance, 'fine tuning' of the composition of high T(c) superconducting thin films, formation of buried conducting layers in silicon, and other research purposes. Here we describe the implantation facility and some of the research programs carried out at our laboratory and collaboratively with others. RP BROWN, IG (reprint author), UNIV CALIF BERKELEY LAWRENCE BERKELEY LAB,BERKELEY,CA 94720, USA. NR 0 TC 24 Z9 24 U1 0 U2 1 PU ASM INTERNATIONAL PI MATERIALS PARK PA SUBSCRIPTIONS SPECIALIST CUSTOMER SERVICE, MATERIALS PARK, OH 44073-0002 SN 0931-7058 J9 J MATER ENG PD SEP PY 1991 VL 13 IS 3 BP 217 EP 228 DI 10.1007/BF02834181 PG 12 WC Materials Science, Multidisciplinary SC Materials Science GA GC288 UT WOS:A1991GC28800006 ER PT J AU BASU, SN CARIM, AH MITCHELL, TE AF BASU, SN CARIM, AH MITCHELL, TE TI A TEM STUDY OF MICROSTRUCTURES OF YBA2CU3O7-X THIN-FILMS DEPOSITED ON LAA1O3 BY LASER ABLATION SO JOURNAL OF MATERIALS RESEARCH LA English DT Article ID BA-CU-O; TRANSMISSION ELECTRON-MICROSCOPY; SRTIO3; DECOMPOSITION; BOUNDARY; GROWTH AB The microstructures of YBa2Cu3O7-x thin films deposited by laser ablation on single crystal (001) LaAlO3 substrates have been investigated. The orientation of the YBa2Cu3O7-x layer next to the interface is found to be completely c-perpendicular, with a high degree of epitaxy between the film and the substrate. Misfit dislocations, with a periodic spacing of around 13 nm, are present at the interface. Two distinct interfacial structures are seen in these films. At a film thickness of around 400 nm, nucleation of c-parallel grains occurs, leading to a switchover from a c-perpendicular to a c-parallel microstructure. Amorphous particulates, ejected from the target during processing, lead to the formation of misoriented grains, giving rise to high-angle grain boundaries in the film. C1 PENN STATE UNIV,DEPT MAT SCI & ENGN,UNIVERSITY PK,PA 16802. UNIV CALIF LOS ALAMOS SCI LAB,CTR MAT SCI,LOS ALAMOS,NM 87545. RP BASU, SN (reprint author), BOSTON UNIV,DEPT MFG ENGN,BOSTON,MA 02215, USA. NR 30 TC 38 Z9 38 U1 0 U2 0 PU MATERIALS RESEARCH SOCIETY PI PITTSBURGH PA 9800 MC KNIGHT ROAD SUITE 327, PITTSBURGH, PA 15237 SN 0884-2914 J9 J MATER RES JI J. Mater. Res. PD SEP PY 1991 VL 6 IS 9 BP 1823 EP 1828 DI 10.1557/JMR.1991.1823 PG 6 WC Materials Science, Multidisciplinary SC Materials Science GA GF550 UT WOS:A1991GF55000003 ER PT J AU HAN, D PANKOVE, JI TSUO, YS QIU, CH XU, Y AF HAN, D PANKOVE, JI TSUO, YS QIU, CH XU, Y TI IMPROVEMENT OF A-SI1-XCX-H/A-SI-HP/I INTERFACE BY HYDROGEN-PLASMA FLUSHING STUDIED BY PHOTOLUMINESCENCE SO JOURNAL OF MATERIALS RESEARCH LA English DT Article ID AMORPHOUS-SILICON; SI-H; LUMINESCENCE; RECOMBINATION AB A hydrogen-plasma reactive flush of the glow discharge reactor after boron-doped a-Si1-xCx : H film deposition has been used to reduce boron contamination of subsequently deposited intrinsic a-Si:H. Photoluminescence studies of p/i structures in a-Si:H show that the hydrogen-plasma process increases both the luminescence efficiency and the activation energy for the competing nonradiative recombination. The process also shifts the emission peak to higher energies by 25 meV. C1 SOLAR ENERGY RES INST,GOLDEN,CO 80401. RP HAN, D (reprint author), UNIV COLORADO,BOULDER,CO 80309, USA. NR 10 TC 1 Z9 1 U1 0 U2 0 PU MATERIALS RESEARCH SOCIETY PI PITTSBURGH PA 9800 MC KNIGHT ROAD SUITE 327, PITTSBURGH, PA 15237 SN 0884-2914 J9 J MATER RES JI J. Mater. Res. PD SEP PY 1991 VL 6 IS 9 BP 1900 EP 1904 DI 10.1557/JMR.1991.1900 PG 5 WC Materials Science, Multidisciplinary SC Materials Science GA GF550 UT WOS:A1991GF55000012 ER PT J AU TRATNIK, MV AF TRATNIK, MV TI SOME MULTIVARIABLE ORTHOGONAL POLYNOMIALS OF THE ASKEY TABLEAU-DISCRETE FAMILIES SO JOURNAL OF MATHEMATICAL PHYSICS LA English DT Article ID HYPERGEOMETRIC-SERIES; U(N) AB A multivariable generalization is presented for all the discrete families of the Askey tableau. This significantly extends the multivariable Hahn polynomials introduced by Karlin and McGregor. The latter are recovered as a limit case from a family of multivariable Racah polynomials. C1 UNIV CALIF LOS ALAMOS SCI LAB,DIV THEORET,LOS ALAMOS,NM 87544. RP TRATNIK, MV (reprint author), UNIV CALIF LOS ALAMOS SCI LAB,CTR NONLINEAR STUDIES,LOS ALAMOS,NM 87544, USA. NR 12 TC 36 Z9 37 U1 0 U2 0 PU AMER INST PHYSICS PI WOODBURY PA CIRCULATION FULFILLMENT DIV, 500 SUNNYSIDE BLVD, WOODBURY, NY 11797-2999 SN 0022-2488 J9 J MATH PHYS JI J. Math. Phys. PD SEP PY 1991 VL 32 IS 9 BP 2337 EP 2342 DI 10.1063/1.529158 PG 6 WC Physics, Mathematical SC Physics GA GC369 UT WOS:A1991GC36900008 ER PT J AU WELLER, RE MALAGA, CA BUSCHBOM, RL BAER, JF RAGAN, HA AF WELLER, RE MALAGA, CA BUSCHBOM, RL BAER, JF RAGAN, HA TI PROTEIN-CONCENTRATION IN URINE OF NORMAL OWL MONKEYS SO JOURNAL OF MEDICAL PRIMATOLOGY LA English DT Note DE PROTEINURIA; GLOMERULONEPHROPATHY; MALARIA; NIGHT MONKEY ID CREATININE RATIO; PRINCIPLE; EXCRETION; DOGS AB The excretion of urinary protein was evaluated in 62 owl monkeys using timed urine collections. The ratio of urine protein to urine creatinine concentrations (Up/c) was determined for each monkey. Linear regression analysis was used to calculate the correlation between that ratio and urine protein (mg/dl) and 24-hour urinary protein loss (mg/kg). The coefficient of determination for Up/c to urine protein and 24-hour urinary protein loss was significant (P less-than-or-equal-to 0.0001). Determination of the Up/c in a urine specimen was found to be an acceptable diagnostic technique for detection and quantitative estimation of proteinuria. RP WELLER, RE (reprint author), PACIFIC NW LAB, DEV TOXICOL SECT, P7-50, POB 999, RICHLAND, WA 99352 USA. NR 19 TC 4 Z9 4 U1 0 U2 0 PU MUNKSGAARD INT PUBL LTD PI COPENHAGEN PA 35 NORRE SOGADE, PO BOX 2148, DK-1016 COPENHAGEN, DENMARK SN 0047-2565 J9 J MED PRIMATOL JI J. Med. Primatol. PD SEP PY 1991 VL 20 IS 7 BP 365 EP 369 PG 5 WC Veterinary Sciences; Zoology SC Veterinary Sciences; Zoology GA GX044 UT WOS:A1991GX04400008 PM 1787533 ER PT J AU MALAGA, CA WELLER, RE BUSCHBOM, RL AF MALAGA, CA WELLER, RE BUSCHBOM, RL TI TWINNING IN THE KARYOTYPE-I NIGHT MONKEY (AOTUS-NANCYMAI) SO JOURNAL OF MEDICAL PRIMATOLOGY LA English DT Note DE TWINNING; REPRODUCTION; DEVELOPMENT; WEIGHT GAIN; GROWTH, OWL MONKEYS AB A case of successful survival of twins in a Karyotype I (2n = 54) night monkey (Aotus nancymai) is described. Monthly weights of the pregnant female, and of the twins, are compared to those of pregnant females and their single birth offspring of the same sex and karyotype. C1 PACIFIC NW LAB, RICHLAND, WA 99352 USA. RP MALAGA, CA (reprint author), UNIV PUERTO RICO, CTR ANIM RESOURCES, POB 365067, SAN JUAN, PR 00936 USA. NR 3 TC 6 Z9 7 U1 0 U2 1 PU MUNKSGAARD INT PUBL LTD PI COPENHAGEN PA 35 NORRE SOGADE, PO BOX 2148, DK-1016 COPENHAGEN, DENMARK SN 0047-2565 J9 J MED PRIMATOL JI J. Med. Primatol. PD SEP PY 1991 VL 20 IS 7 BP 370 EP 372 PG 3 WC Veterinary Sciences; Zoology SC Veterinary Sciences; Zoology GA GX044 UT WOS:A1991GX04400009 PM 1787534 ER PT J AU PAGE, TF MCHARGUE, CJ WHITE, CW AF PAGE, TF MCHARGUE, CJ WHITE, CW TI SEM ELECTRON CHANNELING PATTERNS AS A TECHNIQUE FOR THE CHARACTERIZATION OF ION-IMPLANTATION DAMAGE SO JOURNAL OF MICROSCOPY-OXFORD LA English DT Article DE SCANNING ELECTRON MICROSCOPY; ELECTRON CHANNELING PATTERNS; ION IMPLANTATION; RADIATION DAMAGE ID CERAMICS; SILICON AB Electron channelling patterns (ECPs) formed in back-scattered images in the scanning electron microscope (SEM) have been used occasionally to confirm surface amorphization during ion implantation. In order to place such observations on a more quantitative basis, the study reported here has explored the variation of ECP appearance with both specimen damage levels (and thus subsurface structures) and SEM accelerating voltage (i.e. sampled depth). Polished and annealed (0001) single crystal sapphire discs were implanted to various damage levels up to both subsurface and full surface amorphization. Damage levels were measured independently by Rutherford back-scattering (RBS). Selected-area ECPs were obtained in a Jeol-840 electron microscope operating over the range 5-40 kV in 5-kV steps. Progressive ECP degradation-in terms of high-order line disappearance-was observed with increasing dose, culminating in total pattern loss when full surface amorphization occurred. However, ECP information could still be obtained from the damaged near-surface material even when a subsurface amorphous layer was present, thus demonstrating the shallow retrieval depth of information from the ECP technique. Indeed, because the spatial distribution of damage from ion implantation is both calculable and measurable, these experiments have also allowed us, for the first time, to explore and demonstrate the shallow sample depths from which the majority of ECP contrast originates (< 150 nm in sapphire at an accelerating voltage of 35 kV), even when the beam penetration is considerable by comparison (approximately 5-mu-m). Furthermore, the way in which this sampled depth varies with SEM accelerating voltage is both demonstrated and shown to be a powerful diagnostic technique for studying the distribution of near-surface structural damage. C1 OAK RIDGE NATL LAB,OAK RIDGE,TN 37831. RP PAGE, TF (reprint author), UNIV NEWCASTLE UPON TYNE,DEPT MECH MAT & MFG ENGN,DIV MAT,NEWCASTLE TYNE NE1 7RU,TYNE & WEAR,ENGLAND. NR 20 TC 6 Z9 6 U1 0 U2 4 PU BLACKWELL SCIENCE LTD PI OXFORD PA OSNEY MEAD, OXFORD, OXON, ENGLAND OX2 0EL SN 0022-2720 J9 J MICROSC-OXFORD JI J. Microsc.-Oxf. PD SEP PY 1991 VL 163 BP 245 EP 260 PN 3 PG 16 WC Microscopy SC Microscopy GA GG892 UT WOS:A1991GG89200001 ER PT J AU SUGAMA, T CARCIELLO, N TAYLOR, C AF SUGAMA, T CARCIELLO, N TAYLOR, C TI PYROGENIC POLYGERMANOSILOXANE COATINGS FOR ALUMINUM SUBSTRATES SO JOURNAL OF NON-CRYSTALLINE SOLIDS LA English DT Article AB The factors governing the film-forming performance of pre-ceramic Polygermanosiloxan (PGS) coatings for aluminum (Al) substrate surfaces were investigated. The coatings were prepared through the hydrolysis-dehydrochlorinating and dehydrating condensations-pyrolysis reactions of a sol-precursor solution consisting of N-[3-(triethoxysilyl)propyl]-4,5-dihydroimidazole, Ge(OC2H5)4, water, CH3OH, and HCl. Six factors were important in obtaining a good film: (1) the high spreadability of the sol solution on the Al surfaces; (2) the formation of organopolygermanosiloxane at sintering temperatures of 150-degrees-C; (3) the pyrolytic conversion at 350-degrees-C into an amorphous PGS network structure in which the Si-O-Ge linkages were moderately enhanced; (4) the persistence of only minimum amounts of organic by-products; (5) the non-crystalline phases; and (6) the formation of interfacial oxane bond between PGS and aluminum oxide. C1 UNIV VIRGINIA,DEPT CHEM,CHARLOTTESVILLE,VA 22903. RP SUGAMA, T (reprint author), BROOKHAVEN NATL LAB,DEPT APPL SCI,DIV ENERGY EFFICIENCY & CONSERVAT,UPTON,NY 11973, USA. NR 17 TC 16 Z9 16 U1 0 U2 3 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0022-3093 J9 J NON-CRYST SOLIDS JI J. Non-Cryst. Solids PD SEP PY 1991 VL 134 IS 1-2 BP 58 EP 70 DI 10.1016/0022-3093(91)90011-T PG 13 WC Materials Science, Ceramics; Materials Science, Multidisciplinary SC Materials Science GA GF665 UT WOS:A1991GF66500009 ER PT J AU THOMAS, LE SLAGLE, OD EINZIGER, RE AF THOMAS, LE SLAGLE, OD EINZIGER, RE TI NONUNIFORM OXIDATION OF LWR SPENT FUEL IN AIR SO JOURNAL OF NUCLEAR MATERIALS LA English DT Article ID UO2 AB Oxidation of light-water-reactor (LWR) spent fuel fragments in air at 175-degrees-C was investigated by ceramography, X-ray diffractometry, and transmission electron microscopy. Enhanced oxidation of the original fuel pellet edge was observed in a typical oxidized fragment and the local structures were analyzed in micro-core samples. The oxidation proceeded by advance U4O9 formation along grain boundaries, grain boundary microcracking, and subsequent U4O9 growth into enveloped UO2 grains. No U3O7 or higher oxidation products were detected even near fragment edges where UO2 conversion was complete. The tendency of LWR spent fuel to oxidize along grain boundaries has been attributed to short circuit oxygen penetration through fission gas microbubbles concentrated on the boundaries. Enhanced grain boundary oxidation of the pellet edges in low-gas-release LWR fuel is further attributed to temperature-related variations in bubble spacing, and is seen as a complicating factor in attempts to model postirradiation oxidation behavior. RP THOMAS, LE (reprint author), PACIFIC NW LAB, RICHLAND, WA 99352 USA. NR 21 TC 19 Z9 19 U1 0 U2 2 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0022-3115 J9 J NUCL MATER JI J. Nucl. Mater. PD SEP PY 1991 VL 184 IS 2 BP 117 EP 126 DI 10.1016/0022-3115(91)90502-X PG 10 WC Materials Science, Multidisciplinary; Nuclear Science & Technology SC Materials Science; Nuclear Science & Technology GA GD379 UT WOS:A1991GD37900006 ER PT J AU LARSON, SM CARRASQUILLO, JA COLCHER, DC YOKOYAMA, K REYNOLDS, JC BACHARACH, SA RAUBITCHEK, A PACE, L FINN, RD ROTMAN, M STABIN, M NEUMANN, RD SUGARBAKER, P SCHLOM, J AF LARSON, SM CARRASQUILLO, JA COLCHER, DC YOKOYAMA, K REYNOLDS, JC BACHARACH, SA RAUBITCHEK, A PACE, L FINN, RD ROTMAN, M STABIN, M NEUMANN, RD SUGARBAKER, P SCHLOM, J TI ESTIMATES OF RADIATION ABSORBED DOSE FOR INTRAPERITONEALLY ADMINISTERED I-131 RADIOLABELED B72.3 MONOCLONAL-ANTIBODY IN PATIENTS WITH PERITONEAL CARCINOMATOSES SO JOURNAL OF NUCLEAR MEDICINE LA English DT Article ID F(AB')2 FRAGMENTS; COLON CANCER; TUMOR; RADIOIMMUNOTHERAPY; CELLS; MICE AB Using a newly available model for determining estimates of radiation absorbed dose of radioisotopes administered intraperitoneally, we have calculated absorbed dose to tumor and normal tissues based on a surgically controlled study of radiolabeled antibody distribution. Ten patients with peritoneal carcinomatosis received intraperitoneal injections of the murine monoclonal antibody B72.3 radiolabeled with I-131. Biodistribution studies were performed using nuclear medicine methods until laparotomy at 4-14 days after injection. Surgical biopsies of normal tissues and tumor were obtained. The marrow was predicted to be the critical organ, with maximum tolerated dose [200 rad (2 Gy) to marrow] expected at about 200 mCi (7.4 GBq). In patients with large intraperitoneal tumor deposits, the tumor itself is an important source tissue for radiation exposure to normal tissues. Local "hot-spots" for tumor-absorbed dose were observed, with maximum tumor-absorbed dose calculated at 11000 rad (11 Gy) per 100 mCi (3.7 GBq) administered intraperitoneal; however, tumor rad dose varied considerably. This may pose serious problems for curative therapy, especially in patients with large tumor burdens. C1 NIH,CTR RADIOL,DEPT NUCL MED,BETHESDA,MD 20892. NIH,SURG ONCOL BRANCH,DIV CANC BIOL,TUMOR IMMUNOL & BIOL BRANCH,BETHESDA,MD 20892. NIH,DIV CANC TREATMENT,RADIAT ONCOL BRANCH,BETHESDA,MD 20892. OAK RIDGE ASSOCIATED UNIV,CTR RADIOPHARMACEUT INTERNAL DOSE INFORMAT,OAK RIDGE,TN 37830. RP LARSON, SM (reprint author), MEM SLOAN KETTERING CANC CTR,NUCL MED SERV,1275 YORK AVE,NEW YORK,NY 10021, USA. RI Carrasquillo, Jorge/E-7120-2010; OI Pace, Leonardo/0000-0002-5741-543X; Carrasquillo, Jorge/0000-0002-8513-5734 NR 24 TC 31 Z9 32 U1 0 U2 2 PU SOC NUCLEAR MEDICINE INC PI RESTON PA 1850 SAMUEL MORSE DR, RESTON, VA 22090-5316 SN 0161-5505 J9 J NUCL MED JI J. Nucl. Med. PD SEP PY 1991 VL 32 IS 9 BP 1661 EP 1667 PG 7 WC Radiology, Nuclear Medicine & Medical Imaging SC Radiology, Nuclear Medicine & Medical Imaging GA GD043 UT WOS:A1991GD04300005 PM 1880565 ER PT J AU ATKINS, HL MAUSNER, LF CABAHUG, CJ MEINKEN, GE STRAUB, RF WEBER, DA SRIVASTAVA, SC AF ATKINS, HL MAUSNER, LF CABAHUG, CJ MEINKEN, GE STRAUB, RF WEBER, DA SRIVASTAVA, SC TI TIN-117M(4+)DTPA - A POTENTIAL AGENT FOR PAIN PALLIATION FROM OSSEOUS METASTASES SO JOURNAL OF NUCLEAR MEDICINE LA English DT Meeting Abstract C1 BROOKHAVEN NATL LAB,UPTON,NY 11973. SUNY STONY BROOK,STONY BROOK,NY 11794. NR 0 TC 1 Z9 1 U1 0 U2 0 PU SOC NUCLEAR MEDICINE INC PI RESTON PA 1850 SAMUEL MORSE DR, RESTON, VA 22090-5316 SN 0161-5505 J9 J NUCL MED JI J. Nucl. Med. PD SEP PY 1991 VL 32 IS 9 BP 1840 EP 1840 PG 1 WC Radiology, Nuclear Medicine & Medical Imaging SC Radiology, Nuclear Medicine & Medical Imaging GA GD043 UT WOS:A1991GD04300071 ER PT J AU WEBER, DA CABAHUG, C IVANOVIC, M WONG, CTC ROQUE, C AF WEBER, DA CABAHUG, C IVANOVIC, M WONG, CTC ROQUE, C TI QUANTITATIVE LOCALIZATION AND CLEARANCE PROPERTIES OF TC-99M HMPAO AND I-123 IMP IN THE BRAIN OF CONTROL SUBJECTS AND CRACK USERS SO JOURNAL OF NUCLEAR MEDICINE LA English DT Meeting Abstract C1 BROOKHAVEN NATL LAB,UPTON,NY 11973. SUNY STONY BROOK,DEPT RADIOL,STONY BROOK,NY 11794. NR 0 TC 0 Z9 0 U1 0 U2 0 PU SOC NUCLEAR MEDICINE INC PI RESTON PA 1850 SAMUEL MORSE DR, RESTON, VA 22090-5316 SN 0161-5505 J9 J NUCL MED JI J. Nucl. Med. PD SEP PY 1991 VL 32 IS 9 BP 1840 EP 1840 PG 1 WC Radiology, Nuclear Medicine & Medical Imaging SC Radiology, Nuclear Medicine & Medical Imaging GA GD043 UT WOS:A1991GD04300069 ER PT J AU MEASE, RC MEINKEN, GE LAMBERT, C STEPLEWSKI, Z SRIVASTAVA, SC AF MEASE, RC MEINKEN, GE LAMBERT, C STEPLEWSKI, Z SRIVASTAVA, SC TI NEW LIGANDS FOR LABELING ANTIBODIES WITH COBALT FOR PET IMAGING SO JOURNAL OF NUCLEAR MEDICINE LA English DT Meeting Abstract C1 BROOKHAVEN NATL LAB,DEPT MED,UPTON,NY 11973. WISTAR INST,PHILADELPHIA,PA 19104. NR 0 TC 0 Z9 0 U1 0 U2 1 PU SOC NUCLEAR MEDICINE INC PI RESTON PA 1850 SAMUEL MORSE DR, RESTON, VA 22090-5316 SN 0161-5505 J9 J NUCL MED JI J. Nucl. Med. PD SEP PY 1991 VL 32 IS 9 BP 1842 EP 1842 PG 1 WC Radiology, Nuclear Medicine & Medical Imaging SC Radiology, Nuclear Medicine & Medical Imaging GA GD043 UT WOS:A1991GD04300076 ER PT J AU STROUT, RE MCGRAW, JR HINDMARSH, AC AF STROUT, RE MCGRAW, JR HINDMARSH, AC TI AN EXAMINATION OF THE CONVERSION OF SOFTWARE TO MULTIPROCESSORS SO JOURNAL OF PARALLEL AND DISTRIBUTED COMPUTING LA English DT Article C1 UNIV CALIF LAWRENCE LIVERMORE NATL LAB,DIV COMP & MATH RES,NUMER MATH GRP,LIVERMORE,CA 94550. RP STROUT, RE (reprint author), SUPERCOMP SYST INC,PARALLEL & LANGUAGE TOOLS,LIVERMORE,CA 94550, USA. NR 16 TC 3 Z9 3 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 SEP PY 1991 VL 13 IS 1 BP 1 EP 16 DI 10.1016/0743-7315(91)90105-I PG 16 WC Computer Science, Theory & Methods SC Computer Science GA GD671 UT WOS:A1991GD67100001 ER PT J AU LEE, YD PHILLIPS, PJ LIN, JS AF LEE, YD PHILLIPS, PJ LIN, JS TI THE INFLUENCE OF CRYSTALLINITY DISTRIBUTION ON SMALL-ANGLE X-RAY-SCATTERING FROM SEMICRYSTALLINE POLYMERS SO JOURNAL OF POLYMER SCIENCE PART B-POLYMER PHYSICS LA English DT Article ID ELECTRON-MICROSCOPY; CRYSTALLIZATION; POLYETHYLENE; MELT; MACROMOLECULES; FRACTIONS; BEHAVIOR; MODELS AB Theoretical x-ray scattering curves have been developed for the lamellar structure in semicrystalline polymers in which there are present distributions of lamellar thickness and crystallinity. The models have been tested against samples of linear low-density, low-density and crosslinked polyethylenes. When variation in crystallinity is present in a material, a major effect is an increase in the magnitude of near-zero angle scattering. The Bragg maximum can appear as an ill-defined hump on an apparently high level of background scattering. The shape of the Bragg peak is influenced more by crystallinity distribution than by lamellar thickness distribution. Of the polymers we have studied so far only linear low density polyethylene shows significant crystallinity distribution effects. A "rule-of-thumb" method for rapid estimation of crystallinity distribution effects has been developed, obviating the need for lengthy simulation. C1 OAK RIDGE NATL LAB,NATL CTR SMALL ANGLE SCATTERING RES,OAK RIDGE,TN 37918. RP LEE, YD (reprint author), UNIV TENNESSEE,DEPT MAT SCI & ENGN,KNOXVILLE,TN 37996, USA. NR 36 TC 27 Z9 28 U1 1 U2 8 PU JOHN WILEY & SONS INC PI NEW YORK PA 605 THIRD AVE, NEW YORK, NY 10158-0012 SN 0887-6266 J9 J POLYM SCI POL PHYS JI J. Polym. Sci. Pt. B-Polym. Phys. PD SEP PY 1991 VL 29 IS 10 BP 1235 EP 1254 DI 10.1002/polb.1991.090291008 PG 20 WC Polymer Science SC Polymer Science GA GB717 UT WOS:A1991GB71700008 ER PT J AU STOFT, S KAHN, EP AF STOFT, S KAHN, EP TI AUCTION MARKETS FOR DISPATCHABLE POWER - HOW TO SCORE THE BIDS SO JOURNAL OF REGULATORY ECONOMICS LA English DT Article RP STOFT, S (reprint author), UNIV CALIF BERKELEY LAWRENCE BERKELEY LAB,1 CYCLOTRON RD,BERKELEY,CA 94720, USA. NR 12 TC 6 Z9 6 U1 0 U2 0 PU KLUWER ACADEMIC PUBL PI DORDRECHT PA SPUIBOULEVARD 50, PO BOX 17, 3300 AA DORDRECHT, NETHERLANDS SN 0922-680X J9 J REGUL ECON JI J. Regul. Econ. PD SEP PY 1991 VL 3 IS 3 BP 275 EP 286 DI 10.1007/BF00135366 PG 12 WC Economics SC Business & Economics GA GE885 UT WOS:A1991GE88500005 ER PT J AU STEINWAND, SJ HURNG, WM CORBETT, JD AF STEINWAND, SJ HURNG, WM CORBETT, JD TI THE ZINTL PHASES SR2.2MG11.8GE7 AND SR5MG19GE12 SO JOURNAL OF SOLID STATE CHEMISTRY LA English DT Article ID COBALT PHOSPHIDES; ZR2FE12P7-TYPE STRUCTURE; MAGNETIC-PROPERTIES; CRYSTAL-STRUCTURE; PHOSPHORUS; METAL; CHEMISTRY C1 IOWA STATE UNIV SCI & TECHNOL,US DOE,AMES LAB,AMES,IA 50011. IOWA STATE UNIV SCI & TECHNOL,DEPT CHEM,AMES,IA 50011. NR 22 TC 4 Z9 4 U1 0 U2 1 PU ACADEMIC PRESS INC JNL-COMP SUBSCRIPTIONS PI SAN DIEGO PA 525 B ST, STE 1900, SAN DIEGO, CA 92101-4495 SN 0022-4596 J9 J SOLID STATE CHEM JI J. Solid State Chem. PD SEP PY 1991 VL 94 IS 1 BP 36 EP 44 DI 10.1016/0022-4596(91)90218-7 PG 9 WC Chemistry, Inorganic & Nuclear; Chemistry, Physical SC Chemistry GA GD106 UT WOS:A1991GD10600005 ER PT J AU ELLISON, AJG NAVROTSKY, A AF ELLISON, AJG NAVROTSKY, A TI STOICHIOMETRY AND LOCAL ATOMIC ARRANGEMENTS IN CRYSTALS SO JOURNAL OF SOLID STATE CHEMISTRY LA English DT Article C1 PRINCETON UNIV,DEPT GEOL & GEOPHYS SCI,PRINCETON,NJ 08544. RP ELLISON, AJG (reprint author), ARGONNE NATL LAB,DIV MAT SCI,ARGONNE,IL 60439, USA. NR 13 TC 2 Z9 2 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 0022-4596 J9 J SOLID STATE CHEM JI J. Solid State Chem. PD SEP PY 1991 VL 94 IS 1 BP 130 EP 148 DI 10.1016/0022-4596(91)90227-9 PG 19 WC Chemistry, Inorganic & Nuclear; Chemistry, Physical SC Chemistry GA GD106 UT WOS:A1991GD10600014 ER PT J AU ANSTISS, RG PITZER, KS AF ANSTISS, RG PITZER, KS TI THERMODYNAMICS OF VERY CONCENTRATED AQUEOUS-ELECTROLYTES - LICL, ZNCL2, AND ZNCL2-NACL AT 25-DEGREES-C SO JOURNAL OF SOLUTION CHEMISTRY LA English DT Article DE THERMODYNAMICS; ELECTROLYTE SOLUTIONS; OSMOTIC COEFFICIENTS; ACTIVITY COEFFICIENTS ID OSMOTIC COEFFICIENTS; CHLORIDE; UNIVALENT; SYSTEMS AB The effectiveness of extended ion-interaction equations in the treatment of activity and osmotic coefficients for very concentrated electrolytes is explored for the examples LiCl-H2O, ZnCl2-H2O, and NaCl-ZnCl2-H2O. For the two pure electrolytes the results are very satisfactory. Although satisfactory agreement was also obtained for the solubility of NaCl in the ternary system, this is too limited a data base to justify general conclusions. C1 UNIV CALIF BERKELEY,DEPT CHEM,BERKELEY,CA 94720. UNIV CALIF BERKELEY LAWRENCE BERKELEY LAB,BERKELEY,CA 94720. NR 16 TC 22 Z9 22 U1 2 U2 14 PU PLENUM PUBL CORP PI NEW YORK PA 233 SPRING ST, NEW YORK, NY 10013 SN 0095-9782 J9 J SOLUTION CHEM JI J. Solut. Chem. PD SEP PY 1991 VL 20 IS 9 BP 849 EP 858 DI 10.1007/BF01074948 PG 10 WC Chemistry, Physical SC Chemistry GA GF896 UT WOS:A1991GF89600001 ER PT J AU KETTLER, RM PALMER, DA WESOLOWSKI, DJ AF KETTLER, RM PALMER, DA WESOLOWSKI, DJ TI DISSOCIATION QUOTIENTS OF OXALIC-ACID IN AQUEOUS SODIUM-CHLORIDE MEDIA TO 175-DEGREES-C SO JOURNAL OF SOLUTION CHEMISTRY LA English DT Article DE OXALIC ACID; ETHANEDIOIC ACID; DISSOCIATION CONSTANTS; THERMODYNAMICS; POTENTIOMETRY; IONIC STRENGTH ID NACL MEDIA; IONIZATION; WATER; 300-DEGREES-C; HYDROLYSIS; COMPLEXES; ION AB The first and second molal dissociation quotients of oxalic acid were measured potentiometrically in a concentration cell fitted with hydrogen electrodes. The emf of oxalic acid-bioxalate solutions was measured relative to an HCl standard solution from 25 to 125-degrees-C over 25-degrees intervals at nine ionic strengths ranging from 0.1 to 5.0 molal (NaCl). The molal dissociation quotients and available literature data were treated in the all anionic form by a five-term equation that yielded the following thermodynamic quantities at infinite dilution and 25-degrees-C: log K1a = -1.277 +/- 0.010, DELTA-H-degrees-1a = -4.1 +/- 1.4 kJ-mol-1, DELTA-S-degrees-1a = 38 +/- 4 J-K-1-mol-1, and DELTA-C-degrees-p,1a = -168 +/- 41 J-K-1-mol-1. Similar measurements of the bioxalate-oxalate system were made at 25-degrees intervals from 0 to 175-degrees-C at seven ionic strengths from 0.1 to 5.0m. A similar regression of the experimentally-derived and published equilibrium quotients using a seven-term equation yielded the following values at infinite dilution and 25-degrees-C: log K2a = -4.275 +/- 0.006, DELTA-H-degrees-2a = -6.8 +/- 0.5 kJ-mol-1, DELTA-S-degrees-2a = -105 +/- 2 J-K-1-mol-1, and DELTA-C-degrees-p,2a = -261 +/- 12 J-K-1-mol-1. C1 OAK RIDGE NATL LAB,DIV CHEM,OAK RIDGE,TN 37831. RP KETTLER, RM (reprint author), UNIV NEBRASKA,DEPT GEOL,LINCOLN,NE 68588, USA. NR 39 TC 54 Z9 55 U1 1 U2 6 PU PLENUM PUBL CORP PI NEW YORK PA 233 SPRING ST, NEW YORK, NY 10013 SN 0095-9782 J9 J SOLUTION CHEM JI J. Solut. Chem. PD SEP PY 1991 VL 20 IS 9 BP 905 EP 927 DI 10.1007/BF01074952 PG 23 WC Chemistry, Physical SC Chemistry GA GF896 UT WOS:A1991GF89600005 ER PT J AU LAM, L DOWELL, F BRAND, H AHLERS, G AF LAM, L DOWELL, F BRAND, H AHLERS, G TI THIS SPECIAL ISSUE CONTAINS THE PROCEEDINGS OF THE NATO ADVANCED RESEARCH WORKSHOP ON NONLINEAR DYNAMIC STRUCTURES IN SIMPLE AND COMPLEX LIQUIDS, LOS-ALAMOS, NEW-MEXICO, JUNE 26-29, 1990 - FOREWORD SO JOURNAL OF STATISTICAL PHYSICS LA English DT Editorial Material C1 UNIV ESSEN GESAMTHSCH,W-4300 ESSEN 1,GERMANY. UNIV CALIF LOS ALAMOS SCI LAB,LOS ALAMOS,NM 87544. UNIV CALIF SANTA BARBARA,SANTA BARBARA,CA 93106. RP LAM, L (reprint author), SAN JOSE STATE UNIV,SAN JOSE,CA 95192, USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU PLENUM PUBL CORP PI NEW YORK PA 233 SPRING ST, NEW YORK, NY 10013 SN 0022-4715 J9 J STAT PHYS JI J. Stat. Phys. PD SEP PY 1991 VL 64 IS 5-6 BP 899 EP 901 DI 10.1007/BF01048802 PG 3 WC Physics, Mathematical SC Physics GA GG113 UT WOS:A1991GG11300001 ER PT J AU CHEN, SY DOOLEN, GD MATTHAEUS, WH AF CHEN, SY DOOLEN, GD MATTHAEUS, WH TI LATTICE GAS AUTOMATA FOR SIMPLE AND COMPLEX FLUIDS SO JOURNAL OF STATISTICAL PHYSICS LA English DT Article; Proceedings Paper CT NATO ADVANCED RESEARCH WORKSHOP ON NONLINEAR DYNAMICAL STRUCTURES IN SIMPLE AND COMPLEX LIQUIDS CY JUN 26-29, 1990 CL LOS ALAMOS, NM SP NATO DE LATTICE GAS; FLOW THROUGH POROUS MEDIA; PHASE TRANSITION; THERMOHYDRODYNAMICS; MAGNETOHYDRODYNAMICS ID TIME CORRELATION-FUNCTIONS; CELLULAR AUTOMATA; HYDRODYNAMICS; SIMULATION; MODEL; FLOW; EQUATION; SYSTEMS AB We review some recent applications of lattice gas automata, including flow through porous media, phase transitions, thermodydrodynamics, and magnetohydrodynamics. C1 UNIV CALIF LOS ALAMOS SCI LAB,CNLS,LOS ALAMOS,NM 87545. RP CHEN, SY (reprint author), UNIV DELAWARE,NEWARK,DE 19716, USA. RI Chen, Shiyi/A-3234-2010 NR 83 TC 14 Z9 17 U1 0 U2 3 PU PLENUM PUBL CORP PI NEW YORK PA 233 SPRING ST, NEW YORK, NY 10013 SN 0022-4715 J9 J STAT PHYS JI J. Stat. Phys. PD SEP PY 1991 VL 64 IS 5-6 BP 1133 EP 1162 DI 10.1007/BF01048819 PG 30 WC Physics, Mathematical SC Physics GA GG113 UT WOS:A1991GG11300018 ER PT J AU BARLOW, RE MENSING, RW SMIRIGA, NG AF BARLOW, RE MENSING, RW SMIRIGA, NG TI COMPUTING THE OPTIMAL-DESIGN FOR A CALIBRATION EXPERIMENT SO JOURNAL OF STATISTICAL PLANNING AND INFERENCE LA English DT Article; Proceedings Paper CT 3RD INTERNATIONAL RESEARCH CONF ON RELIABILITY CY MAY 17-19, 1988 CL UNIV MISSOURI COLUMBIA, COLUMBIA, MO HO UNIV MISSOURI COLUMBIA DE BAYESIAN DESIGN OF EXPERIMENTS; CALIBRATION; LINEAR REGRESSION AB A measuring instrument records an observation y which is to be used to estimate the 'true' value of a variable x. Assuming the usual linear model, the problem is to design a calibration experiment. In an earlier paper (Barlow, Mensing and Smiriga (1986)), we obtained general results concerning the structure of the optimal experimental design. However, we were not able to characterize the solution when both alpha and beta are unknown. In this paper, using bivariate normal priors, we show that the objective function, based on squared error loss, can be calculated by a computer program using three nested subroutines for each design. Numerical results for special cases are discussed. C1 UNIV CALIF BERKELEY,ENGN SYST RES CTR,BERKELEY,CA 94720. UNIV CALIF LAWRENCE LIVERMORE NATL LAB,INST SCI COMP RES,LIVERMORE,CA 94550. NR 6 TC 3 Z9 3 U1 0 U2 2 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0378-3758 J9 J STAT PLAN INFER JI J. Stat. Plan. Infer. PD SEP-OCT PY 1991 VL 29 IS 1-2 BP 5 EP 19 PG 15 WC Statistics & Probability SC Mathematics GA GG705 UT WOS:A1991GG70500003 ER PT J AU LEE, CC FATMI, HA AF LEE, CC FATMI, HA TI RUN-TIME SUPPORT FOR PARALLEL FUNCTIONAL PROGRAMMING ON SHARED-MEMORY MULTIPROCESSORS SO JOURNAL OF SYSTEMS AND SOFTWARE LA English DT Article AB The use of functional languages for parallel computing has been proposed for many years. Many functional languages were developed along with the design of new architectures such as data flow and reduction machines. In this article, we present a general model of a run-time system for a parallel functional language called SISAL, to be executed on shared-memory multiprocessors. The implementation of this run-time system is examined on two radically different architectures: a 32-way (symmetrical) VAX Research Multiprocessor M31 and a 4-way Cray X-MP system. To properly evaluate the effectiveness of SISAL on shared-memory multiprocessors, we suggest further research explore an interactive visual control mechanism that dynamically shows run-time behavior. C1 UNIV CALIF LAWRENCE LIVERMORE NATL LAB,LIVERMORE,CA 94550. UNIV LONDON KINGS COLL,LONDON WC2R 2LS,ENGLAND. NR 15 TC 0 Z9 0 U1 0 U2 0 PU ELSEVIER SCIENCE INC PI NEW YORK PA 655 AVENUE OF THE AMERICAS, NEW YORK, NY 10010 SN 0164-1212 J9 J SYST SOFTWARE JI J. Syst. Softw. PD SEP PY 1991 VL 16 IS 1 BP 69 EP 74 PG 6 WC Computer Science, Software Engineering; Computer Science, Theory & Methods SC Computer Science GA GE381 UT WOS:A1991GE38100008 ER PT J AU BECHER, PF FULLER, ER ANGELINI, P AF BECHER, PF FULLER, ER ANGELINI, P TI MATRIX-GRAIN-BRIDGING CONTRIBUTIONS TO THE TOUGHNESS OF WHISKER-REINFORCED CERAMICS SO JOURNAL OF THE AMERICAN CERAMIC SOCIETY LA English DT Article ID FRACTURE-RESISTANCE MECHANISM; TOUGHENING BEHAVIOR; CRACK-RESISTANCE; SILICON-CARBIDE; SIZE DEPENDENCE; SIC WHISKERS; ALUMINA; COMPOSITES; ANISOTROPY; ENERGY AB The fracture toughness of whisker-reinforced, noncubic ceramic matrices increases with increases in matrix grain size, d, as well as with increases in whisker content. An analytical description for the grain-bridging toughening contribution is combined with the whisker-bridging contribution to describe the toughness of such composites. Results for SiC-whisker-reinforced alumina composites confirm both the predicted grain-size effect and the coupled toughening response in the presence of these two toughening mechanisms. C1 NATL INST STAND & TECHNOL, DIV CERAM, GAITHERSBURG, MD 20899 USA. RP BECHER, PF (reprint author), OAK RIDGE NATL LAB, DIV MET & CERAM, OAK RIDGE, TN 37831 USA. NR 34 TC 32 Z9 32 U1 0 U2 4 PU WILEY-BLACKWELL PI HOBOKEN PA 111 RIVER ST, HOBOKEN 07030-5774, NJ USA SN 0002-7820 EI 1551-2916 J9 J AM CERAM SOC JI J. Am. Ceram. Soc. PD SEP PY 1991 VL 74 IS 9 BP 2131 EP 2135 DI 10.1111/j.1151-2916.1991.tb08271.x PG 5 WC Materials Science, Ceramics SC Materials Science GA GF916 UT WOS:A1991GF91600013 ER PT J AU ABRAHAM, MM BAMBERGER, CE AF ABRAHAM, MM BAMBERGER, CE TI ELECTRON-PARAMAGNETIC RESONANCE SPECTROSCOPIC DETERMINATION OF TI-3+ IN SEVERAL TITANIUM PHOSPHATE-COMPOUNDS SO JOURNAL OF THE AMERICAN CERAMIC SOCIETY LA English DT Note AB Electron paramagnetic resonance (EPR) spectroscopy was used to test the presence of Ti3+ in several novel compounds also containing Ti4+. The results obtained confirmed the presence of Ti3+. and indicated that differences in the EPR spectral lines of Ti3+ can make differentiation easier between compounds which have X-ray diffraction (XRD) patterns that are not markedly different. RP ABRAHAM, MM (reprint author), OAK RIDGE NATL LAB,OAK RIDGE,TN 37831, USA. NR 3 TC 3 Z9 3 U1 0 U2 2 PU AMER CERAMIC SOC PI WESTERVILLE PA 735 CERAMIC PLACE, PO BOX 6136, WESTERVILLE, OH 43081-6136 SN 0002-7820 J9 J AM CERAM SOC JI J. Am. Ceram. Soc. PD SEP PY 1991 VL 74 IS 9 BP 2299 EP 2300 DI 10.1111/j.1151-2916.1991.tb08300.x PG 2 WC Materials Science, Ceramics SC Materials Science GA GF916 UT WOS:A1991GF91600042 ER PT J AU ONG, JL HARRIS, LA LUCAS, LC LACEFIELD, WR RIGNEY, D AF ONG, JL HARRIS, LA LUCAS, LC LACEFIELD, WR RIGNEY, D TI X-RAY PHOTOELECTRON-SPECTROSCOPY CHARACTERIZATION OF ION-BEAM SPUTTER-DEPOSITED CALCIUM-PHOSPHATE COATINGS SO JOURNAL OF THE AMERICAN CERAMIC SOCIETY LA English DT Note AB X-ray photoelectron spectroscopy (XPS) analysis of sputter-deposited calcium phosphate coatings on titanium substrates revealed four distinct zones. The ambient-exposed surface exhibited elevated concentrations of carbon because of atmospheric contamination. The bulk zone contained relatively constant concentrations of calcium, oxygen, phosphorus, and fluorine indicating the chemistry for calcium fluoride (CaF2) and fluorapatite (Ca5(PO4)3F) formation. The transitional zone exhibited elevated titanium and oxygen photoelectron peaks suggesting the coexistence of calcium phosphate compounds within the titanium oxide. The substrate was shown to be identical to the passivated titanium surface prior to deposition. C1 OAK RIDGE NATL LAB,OAK RIDGE,TN 37831. UNIV ALABAMA,DEPT DENT BIOMAT,BIRMINGHAM,AL 35294. UNIV ALABAMA,DEPT MAT SCI & ENGN,BIRMINGHAM,AL 35294. RP ONG, JL (reprint author), UNIV ALABAMA,DEPT BIOMED ENGN,BIRMINGHAM,AL 35294, USA. NR 29 TC 30 Z9 32 U1 0 U2 4 PU AMER CERAMIC SOC PI WESTERVILLE PA 735 CERAMIC PLACE, PO BOX 6136, WESTERVILLE, OH 43081-6136 SN 0002-7820 J9 J AM CERAM SOC JI J. Am. Ceram. Soc. PD SEP PY 1991 VL 74 IS 9 BP 2301 EP 2304 DI 10.1111/j.1151-2916.1991.tb08301.x PG 4 WC Materials Science, Ceramics SC Materials Science GA GF916 UT WOS:A1991GF91600043 ER PT J AU ODEN, LL AF ODEN, LL TI CONTRIBUTION TO THE PHASE-DIAGRAM AL4C3-ALN-SIC - REPLY SO JOURNAL OF THE AMERICAN CERAMIC SOCIETY LA English DT Note RP ODEN, LL (reprint author), US BUR MINES,ALBANY RES CTR,ALBANY,OR 97321, USA. NR 2 TC 0 Z9 0 U1 0 U2 0 PU AMER CERAMIC SOC PI WESTERVILLE PA 735 CERAMIC PLACE, PO BOX 6136, WESTERVILLE, OH 43081-6136 SN 0002-7820 J9 J AM CERAM SOC JI J. Am. Ceram. Soc. PD SEP PY 1991 VL 74 IS 9 BP 2329 EP 2329 DI 10.1111/j.1151-2916.1991.tb08310.x PG 1 WC Materials Science, Ceramics SC Materials Science GA GF916 UT WOS:A1991GF91600052 ER PT J AU GRIMM, CC SHORT, RT TODD, PJ AF GRIMM, CC SHORT, RT TODD, PJ TI A WIDE-ANGLE SECONDARY ION PROBE FOR ORGANIC ION IMAGING SO JOURNAL OF THE AMERICAN SOCIETY FOR MASS SPECTROMETRY LA English DT Article ID MASS-SPECTROMETRY; EMISSION AB A secondary ion source has been developed for an organic ion microprobe capable of imaging samples up to 2 cm in diameter. The source uses a focused 5 keV Cs+ ion beam which is rastered across the sample surface, and secondary ions from each point on the sample are collected and formed into a low energy beam to be analyzed by a quadrupole mass filter. Dynamic emittance matching is employed to deflect ions from off-axis points on the sample back onto the mass analyzer axis. Rastering and dynamic emittance matching are rapidly controlled by assembly language programs using an IBM/AT (80286) type computer. A low energy ion monitor was used to tune and evaluate the secondary ion source by providing a magnified cross-sectional image of the ion beam at the source exit aperture. A well-focused and centered secondary ion beam was obtained from each point on the sample, indicating that large-scale dynamic emittance matching with high collection efficiency is possible. Mass resolved images of grids and glycerol samples are shown to demonstrate the performance of the integrated secondary ion source mass analyzer and control system. C1 OAK RIDGE NATL LAB,OAK RIDGE,TN 37831. NR 17 TC 16 Z9 16 U1 0 U2 0 PU ELSEVIER SCIENCE INC PI NEW YORK PA 655 AVENUE OF THE AMERICAS, NEW YORK, NY 10010 SN 1044-0305 J9 J AM SOC MASS SPECTR JI J. Am. Soc. Mass Spectrom. PD SEP-OCT PY 1991 VL 2 IS 5 BP 362 EP 371 DI 10.1016/1044-0305(91)85002-N PG 10 WC Biochemical Research Methods; Chemistry, Analytical; Chemistry, Physical; Spectroscopy SC Biochemistry & Molecular Biology; Chemistry; Spectroscopy GA GC827 UT WOS:A1991GC82700002 PM 24242687 ER PT J AU HETTICH, R BUCHANAN, M AF HETTICH, R BUCHANAN, M TI STRUCTURAL CHARACTERIZATION OF NORMAL AND MODIFIED OLIGONUCLEOTIDES BY MATRIX-ASSISTED LASER DESORPTION FOURIER-TRANSFORM MASS-SPECTROMETRY SO JOURNAL OF THE AMERICAN SOCIETY FOR MASS SPECTROMETRY LA English DT Article ID OLIGODEOXYRIBONUCLEOTIDES; IONIZATION; IONS AB Matrix-assisted UV laser desorption Fourier transform mass spectrometry (266 nm, nicotinic acid matrix) can be used for the detailed structural characterization of normal and modified oligonucleotides. The negative ion spectra for these compounds revealed abundant (M - H)- ions as well as fragment ions that provided the information necessary to determine oligomer sequence and to differentiate isomers. The nicotinic acid matrix was required for the production of (M - H)- ions for the oligonucleotide dimers, trimers, tetramers, and hexamers examined in this study. Elimination of the nicotinic acid matrix resulted in complete loss of the (M - H)- ions as well as most of the larger fragment ions for the oligomers. The primary fragmentation pathway was observed to be phosphate ester bond cleavage with the resulting charge retained on the 3' end of the oligomer and enabled isomeric differentiation of compounds such as d(5'-CGCG-3') and d(5'-CCGG-3'). Collision-induced dissociation experiments of the (M - H)- ions for these compounds confirmed the preferential loss of nucleotides from the 5' end of the oligomers. The presence and location of modifications such as methyl and ethyl alkyl groups to the oligonucleotides could also be identified. RP HETTICH, R (reprint author), OAK RIDGE NATL LAB,DIV ANALYT CHEM,OAK RIDGE,TN 37831, USA. RI Hettich, Robert/N-1458-2016 OI Hettich, Robert/0000-0001-7708-786X NR 27 TC 85 Z9 86 U1 0 U2 0 PU ELSEVIER SCIENCE INC PI NEW YORK PA 655 AVENUE OF THE AMERICAS, NEW YORK, NY 10010 SN 1044-0305 J9 J AM SOC MASS SPECTR JI J. Am. Soc. Mass Spectrom. PD SEP-OCT PY 1991 VL 2 IS 5 BP 402 EP 412 DI 10.1016/1044-0305(91)85006-R PG 11 WC Chemistry, Analytical; Chemistry, Physical; Spectroscopy SC Chemistry; Spectroscopy GA GC827 UT WOS:A1991GC82700006 PM 24242691 ER PT J AU COFFIELD, JE MAMANTOV, G ZINGG, SP SMITH, GP AF COFFIELD, JE MAMANTOV, G ZINGG, SP SMITH, GP TI REDUCTION OF AROMATIC-COMPOUNDS IN ORGANIC CHLOROALUMINATE MELTS .1. PHENAZINE SO JOURNAL OF THE ELECTROCHEMICAL SOCIETY LA English DT Article ID TEMPERATURE MOLTEN-SALT; CHLORIDE IONIC LIQUID; ALUMINUM-CHLORIDE; BUTYLPYRIDINIUM CHLORIDE; MIXTURES; 5,10-DIHYDROPHENAZINE; ELECTROCHEMISTRY; SPECTROSCOPY; COMPLEXES; SPECTRA AB The electroreduction of phenazine in basic mixtures of AlCl3 and 1-ethyl-3-methyl-1H-imidazolium chloride (EMIC) (44.4 mole percent AlCl3) has been investigated by electrochemical and spectroscopic techniques. Initial results suggested that the reduction of phenazine proceeded through a two-electron process coupled with two protonations to form dihydrophenazine. However, further investigation, using authentic dihydrophenazine, indicated that this reduction product was not the result of proton exchange reactions but rather a chloroaluminate species may be acting as the acidic entity in this liquid. The use of neat 1-ethyl-3-methyl-1H-imidazolium hydrogen dichloride (ImHCl2) and mixtures of AlCl3 and 1,2-dimethyl-3-propyl-1H-imidazolium chloride (DMPIC) as solvents for electrochemical investigations of dissolved organic substrates is also reported. C1 OAK RIDGE NATL LAB,DIV CHEM,OAK RIDGE,TN 37831. RP COFFIELD, JE (reprint author), UNIV TENNESSEE,DEPT CHEM,KNOXVILLE,TN 37996, USA. NR 45 TC 3 Z9 3 U1 0 U2 1 PU ELECTROCHEMICAL SOC INC PI PENNINGTON PA 10 SOUTH MAIN STREET, PENNINGTON, NJ 08534 SN 0013-4651 J9 J ELECTROCHEM SOC JI J. Electrochem. Soc. PD SEP PY 1991 VL 138 IS 9 BP 2543 EP 2549 DI 10.1149/1.2086014 PG 7 WC Electrochemistry; Materials Science, Coatings & Films SC Electrochemistry; Materials Science GA GF106 UT WOS:A1991GF10600014 ER PT J AU WEAVER, JK MCLARNON, FR CAIRNS, EJ AF WEAVER, JK MCLARNON, FR CAIRNS, EJ TI EXPERIMENTAL AND THEORETICAL-STUDY OF CONCENTRATION DISTRIBUTIONS IN A MODEL PORE ELECTRODE .1. MEASUREMENT OF 2-DIMENSIONAL CONCENTRATION GRADIENTS IN A ZINC MODEL PORE SO JOURNAL OF THE ELECTROCHEMICAL SOCIETY LA English DT Article ID PHOTOTHERMAL DEFLECTION SPECTROSCOPY; BEAM DEFLECTION AB The optical probe beam deflection technique has been employed to study two-dimensional concentration gradients within the electrolyte of a zinc model pore. The model pore cell constructed for this study retains the small, confined geometry and two-dimensional character of an actual pore within a porous zinc electrode. Refractive index gradients in the direction of the model pore axis showed that the concentration of zincate ion reaches a maximum between the model pore mouth and a position one-fourth of the distance toward the pore root during the anodic oxidation of the zinc electrode. Also, the variation in the refractive index gradient normal to the electrode along the length of the zinc anode allowed us to calculate the local current density within the model pore. C1 UNIV CALIF BERKELEY,DEPT CHEM ENGN,BERKELEY,CA 94720. RP WEAVER, JK (reprint author), UNIV CALIF BERKELEY LAWRENCE BERKELEY LAB,DIV APPL SCI,BERKELEY,CA 94720, USA. RI Cairns, Elton/E-8873-2012 OI Cairns, Elton/0000-0002-1179-7591 NR 16 TC 12 Z9 12 U1 0 U2 2 PU ELECTROCHEMICAL SOC INC PI PENNINGTON PA 10 SOUTH MAIN STREET, PENNINGTON, NJ 08534 SN 0013-4651 J9 J ELECTROCHEM SOC JI J. Electrochem. Soc. PD SEP PY 1991 VL 138 IS 9 BP 2572 EP 2579 DI 10.1149/1.2086019 PG 8 WC Electrochemistry; Materials Science, Coatings & Films SC Electrochemistry; Materials Science GA GF106 UT WOS:A1991GF10600019 ER PT J AU WEAVER, JK MCLARNON, FR CAIRNS, EJ AF WEAVER, JK MCLARNON, FR CAIRNS, EJ TI EXPERIMENTAL AND THEORETICAL-STUDY OF CONCENTRATION DISTRIBUTIONS IN A MODEL PORE ELECTRODE .2. MATHEMATICAL-MODELS AND COMPARISON TO EXPERIMENT SO JOURNAL OF THE ELECTROCHEMICAL SOCIETY LA English DT Article ID POROUS ZINC ELECTRODES; ALKALINE-SOLUTIONS; DISSOLUTION; TRANSIENT AB A two-dimensional numerical model of mass transfer in a zinc model pore has been developed to interpret results obtained using the probe beam deflection technique. The concentrations and concentration gradients of the electrolyte species were calculated by the numerical model and were shown to provide good quantitative agreement with the experimental results. The combination of theoretical and experimental analyses led to an understanding of how the kinetic, geometric, and mass transport parameters determined the current and concentration distributions within the model pore electrolyte. C1 UNIV CALIF BERKELEY,DEPT CHEM ENGN,BERKELEY,CA 94720. RP WEAVER, JK (reprint author), UNIV CALIF BERKELEY LAWRENCE BERKELEY LAB,DIV APPL SCI,BERKELEY,CA 94720, USA. RI Cairns, Elton/E-8873-2012 OI Cairns, Elton/0000-0002-1179-7591 NR 39 TC 8 Z9 9 U1 0 U2 3 PU ELECTROCHEMICAL SOC INC PI PENNINGTON PA 10 SOUTH MAIN STREET, PENNINGTON, NJ 08534 SN 0013-4651 J9 J ELECTROCHEM SOC JI J. Electrochem. Soc. PD SEP PY 1991 VL 138 IS 9 BP 2579 EP 2585 DI 10.1149/1.2086020 PG 7 WC Electrochemistry; Materials Science, Coatings & Films SC Electrochemistry; Materials Science GA GF106 UT WOS:A1991GF10600020 ER PT J AU AHMED, S MCPHEETERS, C KUMAR, R AF AHMED, S MCPHEETERS, C KUMAR, R TI THERMAL-HYDRAULIC MODEL OF A MONOLITHIC SOLID OXIDE FUEL-CELL SO JOURNAL OF THE ELECTROCHEMICAL SOCIETY LA English DT Article AB A mathematical model has been developed to simulate the electrochemistry and thermal hydraulics in a crossflow monolithic solid oxide fuel cell. The fuel cell stack consists of a honeycomb structure of cells with alternating layers of anode, electrolyte, cathode, and interconnect. In each cell of the stack, the porous anode (fuel) layer consists of numerous horizontal channels separated by thin walls. The porous cathode (air) layer lies below the anode and is separated from it by the dense electrolyte. The horizontal flow channels in the cathode run perpendicular to those in the anode. A dense layer of interconnect is sandwiched between successive cells of the stack. Dividing a single-cell layer into a number of nodes, the model sets up the steady-state heat and mass-transfer equations for each node in a cell layer. Based on the average thermal and compositional conditions at each node and a specified cell voltage, the model calculates the Nernst potential and the resultant current, heat generation, and heat removal rates at each node. These calculations yield the temperature and the fuel and oxidant compositions and partial pressure matrices for the entire cell. The simulation also provides related performance data for the fuel cell stack, such as energy efficiency, fuel utilization, and power density. The model can be used to simulate operation with fuel gases other than hydrogen, such as coal gas or synthesis gas. A mathematical model such as this can be used to examine the effects of changing one or more of the various design variables and to evaluate the effectiveness of fabrication improvements in technology development. In the design phase, the model can be used to determine the size of the stack that will be required for a given power rating and to make design decisions regarding structure-specific parameters, such as the thicknesses of the anode, electrolyte, cathode, and interconnect layers and dimensions of the flow channels in the anode and cathode. The model can also be helpful to the fuel cell system operator. Given a particular stack, the most favorable operating conditions can be determined by calculating a priori the effects of altering process variables, such as flow rates and feed conditions. RP AHMED, S (reprint author), ARGONNE NATL LAB,ELECTROCHEM TECHNOL PROGRAM,ARGONNE,IL 60439, USA. NR 7 TC 59 Z9 60 U1 0 U2 3 PU ELECTROCHEMICAL SOC INC PI PENNINGTON PA 10 SOUTH MAIN STREET, PENNINGTON, NJ 08534 SN 0013-4651 J9 J ELECTROCHEM SOC JI J. Electrochem. Soc. PD SEP PY 1991 VL 138 IS 9 BP 2712 EP 2718 DI 10.1149/1.2086042 PG 7 WC Electrochemistry; Materials Science, Coatings & Films SC Electrochemistry; Materials Science GA GF106 UT WOS:A1991GF10600043 ER PT J AU BUTLER, MA AF BUTLER, MA TI FIBER OPTIC SENSOR FOR HYDROGEN CONCENTRATIONS NEAR THE EXPLOSIVE LIMIT SO JOURNAL OF THE ELECTROCHEMICAL SOCIETY LA English DT Letter ID REFLECTIVITY CHANGES; THIN-FILMS; SYSTEM AB A new hydrogen sensor has been demonstrated that provides a large signal for concentrations of hydrogen in air near the explosive limit. This optical fiber sensor is intrinsically safe for use in potentially explosive environments. The sensor responds to changes in the optical properties of a thin palladium film exposed to hydrogen. RP SANDIA NATL LABS, ALBUQUERQUE, NM 87185 USA. NR 10 TC 37 Z9 39 U1 1 U2 6 PU ELECTROCHEMICAL SOC INC PI PENNINGTON PA 65 SOUTH MAIN STREET, PENNINGTON, NJ 08534 USA SN 0013-4651 EI 1945-7111 J9 J ELECTROCHEM SOC JI J. Electrochem. Soc. PD SEP PY 1991 VL 138 IS 9 BP L46 EP L47 DI 10.1149/1.2086073 PG 2 WC Electrochemistry; Materials Science, Coatings & Films SC Electrochemistry; Materials Science GA GF106 UT WOS:A1991GF10600005 ER PT J AU BARNETT, P SCHAEFER, JL NEATHERY, JK SPICER, R GONZALEZ, RE STENCEL, JM AF BARNETT, P SCHAEFER, JL NEATHERY, JK SPICER, R GONZALEZ, RE STENCEL, JM TI THE EFFECT OF CHLORINE ON THE IN-BED TUBE WASTAGE OF ATMOSPHERIC FLUIDIZED-BED COMBUSTORS SO JOURNAL OF THE INSTITUTE OF ENERGY LA English DT Article AB More than 1000 hours of testing were performed in a 1.2 MW(t) atmospheric fluidised-bed combustor, with the goal of examining wastage of in-bed heat-exchanger tubes as a function of chlorine content within the coal fuel. The methods used to measure wastage and tube-surface temperature are described for three tests in which the input chlorine was varied from 0.05 to 0.3%, partly by means of additions of hydrochloric acid gas. Results from these combustion tests, including the fate of feed chlorine, are presented and comparisons are made with tube wastage results from other tests. It was determined that although chlorine influences wastage rates, its deleterious effect is not as dramatic as previously considered. RP BARNETT, P (reprint author), US DOE,PITTSBURGH ENERGY TECHNOL CTR,POB 10940,M-S 022,PITTSBURGH,PA 15236, USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU INST ENERGY PI LONDON PA 18 DEVONSHIRE ST PORTLAND PLACE, LONDON, ENGLAND W1N 2AU SN 0144-2600 J9 J I ENERGY JI J. Inst. Energy PD SEP PY 1991 VL 64 IS 460 BP 157 EP 165 PG 9 WC Energy & Fuels SC Energy & Fuels GA GL232 UT WOS:A1991GL23200005 ER PT J AU TARDY, HL AF TARDY, HL TI MATRIX-METHOD FOR INTEGRATING-SPHERE CALCULATIONS SO JOURNAL OF THE OPTICAL SOCIETY OF AMERICA A-OPTICS IMAGE SCIENCE AND VISION LA English DT Article ID FIELD AB A simple matrix technique is presented for modeling integrating-sphere performance. The method is applicable to any sphere configuration, including those with flat areas, specular samples, and baffles, and is especially effective when used in computer simulations of sphere irradiance. The formalism can accommodate the angular sensitivity of any detector or the bidirectional-reflectance distribution function of any sample. Examples of simple analytical solutions are presented, and computer simulation is demonstrated with calculations of the irradiance inhomogeneities caused by underfilling a flat sample. In particular, the simulation shows that, when the input beam does not completely fill a flat sample, the sample is surrounded by a band of reduced irradiance. Outside this dark band, the irradiance is increased slightly. The width of the dark band, but not its depth, increases as the beam size decreases relative to the sample size. The depth depends on sample size and reflectance. Outside the dark-band region, the irradiance shifts due to sample underfilling are much smaller than the easily avoidable, first-order errors caused by neglecting the flat-sample effects. RP TARDY, HL (reprint author), SANDIA NATL LABS,DIV ELECTR MAT APPLICAT,POB 5800,ALBUQUERQUE,NM 87185, USA. NR 16 TC 18 Z9 20 U1 1 U2 4 PU OPTICAL SOC AMER PI WASHINGTON PA 2010 MASSACHUSETTS AVE NW, WASHINGTON, DC 20036 SN 0740-3232 J9 J OPT SOC AM A JI J. Opt. Soc. Am. A-Opt. Image Sci. Vis. PD SEP PY 1991 VL 8 IS 9 BP 1411 EP 1418 DI 10.1364/JOSAA.8.001411 PG 8 WC Optics SC Optics GA GC968 UT WOS:A1991GC96800007 ER PT J AU CHITANVIS, SM AF CHITANVIS, SM TI ASYMPTOTIC ANALYSIS OF LOADED, UNSTABLE, CYLINDRICAL RESONATORS SO JOURNAL OF THE OPTICAL SOCIETY OF AMERICA A-OPTICS IMAGE SCIENCE AND VISION LA English DT Article ID MODES AB I show that the solution of the electromagnetic equations for a loaded cavity with a large Fresnel number F (F > 100) can be obtained analytically. This asymptotic solution is obtained as a perturbation of the geometrical-optics solution, with edge-diffraction effects appearing as ripples of order 1/(F)1/2. The basic technique is to obtain a series expansion of the relevant integrals in powers of 1/(F)1/2. This scheme works even better if the laser is operating in the saturated regime. This method of solution represents an extension of the method of Butts and Avizonis [J. Opt. Soc. Am. 68, 1072 (1978)], which is applicable to empty, cylindrical, unstable resonators. RP CHITANVIS, SM (reprint author), UNIV CALIF LOS ALAMOS SCI LAB,DIV THEORET,GRP T-12,LOS ALAMOS,NM 87545, USA. NR 6 TC 2 Z9 2 U1 1 U2 1 PU OPTICAL SOC AMER PI WASHINGTON PA 2010 MASSACHUSETTS AVE NW, WASHINGTON, DC 20036 SN 0740-3232 J9 J OPT SOC AM A JI J. Opt. Soc. Am. A-Opt. Image Sci. Vis. PD SEP PY 1991 VL 8 IS 9 BP 1463 EP 1467 DI 10.1364/JOSAA.8.001463 PG 5 WC Optics SC Optics GA GC968 UT WOS:A1991GC96800015 ER PT J AU PIEHLER, D AF PIEHLER, D TI ELECTRONIC COHERENT ANTI-STOKES-RAMAN SPECTROSCOPY IN CEF3 SO JOURNAL OF THE OPTICAL SOCIETY OF AMERICA B-OPTICAL PHYSICS LA English DT Article ID OSCILLATOR-STRENGTHS; CRYSTALS; CE-3+; SCATTERING; EXCITATION; LUPO4; LAF3; TRIFLUORIDES; TRANSITIONS; ABSORPTION AB The coherent anti-Stokes Raman spectroscopy (CARS) of electronic states of the Ce3+ ion in a CeF3 crystal at 3.8 K is reported. CARS resonances involving the ground state of the 2F5/2 manifold and the Stark components of the 2F7/2 manifold at 2161 and 2239 cm-1 have been detected. Measurements were made with both visible (lambda-1 almost-equal-to 476 nm, lambda-2 = 532 nm) and near-ultraviolet (lambda-1 = 355 nm, lambda-2 almost-equal-to 385 nm) lasers. The enhancement of the third-order susceptibility owing to the electronic transitions, \chi-(3)R/chi-(3)NR\max, is as great as 4.8. This represents an order-of-magnitude increase over that in singly resonant electronic CARS experiments in other rare-earth crystals. The CARS data also yielded accurate measurements of the Ce3+ electronic Raman cross sections. In the visible region, sigma-zz(2161 cm-1) = (5.0 +/- 1.1) x 10(-30) cm2 and sigma-zz(2239 cm-1) = (1.9 +/- 0.7) x 10(-30) cm2. One could calculate both the absolute magnitude and the dispersion of \chi-(3)R\max by modeling the virtual intermediate states as a single degenerate 5d state at 45 000 cm-1. C1 UNIV CALIF BERKELEY,DEPT PHYS,BERKELEY,CA 94720. UNIV CALIF BERKELEY LAWRENCE BERKELEY LAB,DIV MAT & CHEM SCI,BERKELEY,CA 94720. NR 41 TC 3 Z9 3 U1 0 U2 1 PU OPTICAL SOC AMER PI WASHINGTON PA 2010 MASSACHUSETTS AVE NW, WASHINGTON, DC 20036 SN 0740-3224 J9 J OPT SOC AM B JI J. Opt. Soc. Am. B-Opt. Phys. PD SEP PY 1991 VL 8 IS 9 BP 1889 EP 1898 DI 10.1364/JOSAB.8.001889 PG 10 WC Optics SC Optics GA GD766 UT WOS:A1991GD76600015 ER PT J AU SACKS, RA SZOKE, A AF SACKS, RA SZOKE, A TI GENERATION OF HARMONIC RADIATION DURING ELECTRON-SCATTERING FROM A PIECEWISE-CONSTANT POTENTIAL IN AN INTENSE ELECTROMAGNETIC-FIELD SO JOURNAL OF THE OPTICAL SOCIETY OF AMERICA B-OPTICAL PHYSICS LA English DT Article ID MULTIPHOTON IONIZATION; RARE-GASES; 1064-NM RADIATION; OPTICAL HARMONICS; SIMPLIFIED MODEL; LASER-RADIATION; ATOM; CONVERSION; HYDROGEN; PULSES AB In a previous study [Phys. Rev. A 40, 5614 (1989)] we presented and discussed an exact solution for the scattering of electrons by a piecewise-constant potential in the presence of a strong electromagnetic field. An intimate connection with the physics of multiphoton ionization was demonstrated. Here we extend that study and present what we believe is the first accurate evaluation of power radiated at harmonics of the applied field frequency during electron scattering from a potential in a strong electromagnetic field. The results are nonperturbative and manifestly gauge invariant. We observe the production of multiple-order harmonics whose relative intensities as a function of harmonic number are similar to those of the above-threshold ionization peaks. No plateau in radiated intensity as a function of harmonic number is seen. Suppression of even harmonics in a symmetric potential is seen if the incoming state is strictly single parity (even or odd), but this suppression is found to be exceedingly sensitive to admixture of a small component of the opposite parity. In scattering from a well with two bound states, we observe a striking minimum in the third-harmonic intensity for incident electron energy close to resonance. RP SACKS, RA (reprint author), UNIV CALIF LAWRENCE LIVERMORE NATL LAB,LIVERMORE,CA 94550, USA. NR 19 TC 11 Z9 11 U1 0 U2 1 PU OPTICAL SOC AMER PI WASHINGTON PA 2010 MASSACHUSETTS AVE NW, WASHINGTON, DC 20036 SN 0740-3224 J9 J OPT SOC AM B JI J. Opt. Soc. Am. B-Opt. Phys. PD SEP PY 1991 VL 8 IS 9 BP 1987 EP 1998 DI 10.1364/JOSAB.8.001987 PG 12 WC Optics SC Optics GA GD766 UT WOS:A1991GD76600026 ER PT J AU CZANDERNA, AW KING, DE SPAULDING, D AF CZANDERNA, AW KING, DE SPAULDING, D TI METAL OVERLAYERS ON ORGANIC FUNCTIONAL-GROUPS OF SELF-ORGANIZED MOLECULAR ASSEMBLIES .1. X-RAY PHOTOELECTRON-SPECTROSCOPY OF INTERACTIONS OF CU/COOH ON 11-MERCAPTOUNDECANOIC ACID SO JOURNAL OF VACUUM SCIENCE & TECHNOLOGY A-VACUUM SURFACES AND FILMS LA English DT Article ID STRUCTURAL CHARACTERIZATION; MONOLAYER FILMS; GOLD SURFACES; ELECTROCHEMICAL PROPERTIES; ADSORPTION; DISULFIDES; INTERFACE; THIOLS; PHASE; ISS AB X-ray photoelectron spectroscopy spectra were recorded after sequential deposition of submonolayer amounts of copper on an organized molecular assembly (OMA) of HS(CH2)10COOH 11-mercaptoundecanoic acid (MUA) on 80-nm-thick gold films on silicon substrates. The self-assembly process results in stable monolayers with the thiol group attached to the gold film and the COOH group as the outer monolayer. Copper deposited in vacuum interacts with the surface of the MUA OMA to produce a unidentate copper complex with the single bonded oxygen atom of the acid monolayer. The data do not support forming a bidentate copper complex or chemical interaction of the double bonded oxygen atom of the acid group with copper. The maximum charge residing on the copper atom of the complex is + 1 with one charged copper atom on the surface per MUA molecule of the OMA. RP CZANDERNA, AW (reprint author), SOLAR ENERGY RES INST,APPL SCI BRANCH,GOLDEN,CO 80401, USA. NR 41 TC 67 Z9 68 U1 1 U2 3 PU AMER INST PHYSICS PI WOODBURY PA CIRCULATION FULFILLMENT DIV, 500 SUNNYSIDE BLVD, WOODBURY, NY 11797-2999 SN 0734-2101 J9 J VAC SCI TECHNOL A JI J. Vac. Sci. Technol. A-Vac. Surf. Films PD SEP-OCT PY 1991 VL 9 IS 5 BP 2607 EP 2613 DI 10.1116/1.577213 PG 7 WC Materials Science, Coatings & Films; Physics, Applied SC Materials Science; Physics GA GG376 UT WOS:A1991GG37600004 ER PT J AU STEARNS, DG ROSEN, RS VERNON, SP AF STEARNS, DG ROSEN, RS VERNON, SP TI FABRICATION OF HIGH-REFLECTANCE MO-SI MULTILAYER MIRRORS BY PLANAR-MAGNETRON SPUTTERING SO JOURNAL OF VACUUM SCIENCE & TECHNOLOGY A-VACUUM SURFACES AND FILMS LA English DT Article ID THIN-FILM MORPHOLOGY; X-RAYS; THERMALIZATION AB Molybdenum-silicon multilayer (ML) x-ray mirrors have been fabricated using a direct-current planar magnetron sputtering system. The ML structure has been characterized using x-ray diffraction and high-resolution electron microscopy, and the normal incidence x-ray reflectivity has been measured using synchrotron radiation. A striking dependence of the ML morphology on the sputtering gas pressure is observed, exhibiting a transition from layer growth at lower pressures to columnar growth at higher pressures. Correspondingly, the normal incidence x-ray reflectivity is found to decrease strongly with increasing gas pressure. By depositing Mo-Si ML at low sputtering gas pressures we have achieved a normal incidence reflectivity as high as 61% at 132 angstrom. C1 VERNON APPL PHYS,TORRANCE,CA 90505. RP STEARNS, DG (reprint author), UNIV CALIF LAWRENCE LIVERMORE NATL LAB,LIVERMORE,CA 94550, USA. NR 31 TC 135 Z9 140 U1 1 U2 11 PU AMER INST PHYSICS PI WOODBURY PA CIRCULATION FULFILLMENT DIV, 500 SUNNYSIDE BLVD, WOODBURY, NY 11797-2999 SN 0734-2101 J9 J VAC SCI TECHNOL A JI J. Vac. Sci. Technol. A-Vac. Surf. Films PD SEP-OCT PY 1991 VL 9 IS 5 BP 2662 EP 2669 DI 10.1116/1.577221 PG 8 WC Materials Science, Coatings & Films; Physics, Applied SC Materials Science; Physics GA GG376 UT WOS:A1991GG37600012 ER PT J AU MUELLER, D LAMARCHE, PH BELL, MG BLANCHARD, W BUSH, CE GENTILE, C HAWRYLUK, RJ HILL, KW JANOS, AC JOBES, FC OWENS, DK PEARSON, G SCHIVELL, J ULRICKSON, MA VANNOY, C WONG, KL DYLLA, HF AF MUELLER, D LAMARCHE, PH BELL, MG BLANCHARD, W BUSH, CE GENTILE, C HAWRYLUK, RJ HILL, KW JANOS, AC JOBES, FC OWENS, DK PEARSON, G SCHIVELL, J ULRICKSON, MA VANNOY, C WONG, KL DYLLA, HF TI DISCHARGE CLEANING ON TOKAMAK FUSION TEST REACTOR AFTER BORONIZATION SO JOURNAL OF VACUUM SCIENCE & TECHNOLOGY A-VACUUM SURFACES AND FILMS LA English DT Article ID ENHANCED CONFINEMENT DISCHARGES; TFTR; 1ST-WALL; LIMITER AB At the beginning of the 1990 Tokamak Fusion Test Reactor (TFTR) experimental run, after replacement of POCO-AXF-5Q graphite tiles on the midplane of the bumper limiter by carbon fiber composite (CFC) tiles and prior to any pulse discharge cleaning (PDC), boronization was performed. Boronization is the deposition of a layer of boron and carbon on the vacuum vessel inner surface by a glow discharge in a diborane, methane, and helium mixture. The amount of discharge cleaning required after boronization was substantially reduced compared to that which was needed after previous openings when boronization was not done. Previously, after a major shutdown, about 10(5) low current (approximately 20 kA) Taylor discharge cleaning (TDC) pulses were required before high current (approximately 400 kA) agressive pulse discharge cleaning (PDC) pulses could be performed successfully. Aggressive PDC is used to heat the limiters form the vessel bakeout temperature of 150 to 250-degrees-C for a period of several hours. Heating the limiters is important to increase the rate at which water is removed from the carbon limiter tiles. After boronization, the number of required TDC pulses was reduced to < 5000. The number of aggressive PDC pulses required was approximately unchanged. C1 CONTINUOUS ELECTRON BEAM ACCELERATOR FACIL CTR,NEWPORT NEWS,VA 23606. RP MUELLER, D (reprint author), PRINCETON PLASMA,PHYS LAB,POB 451,PRINCETON,NJ 08544, USA. NR 14 TC 11 Z9 11 U1 0 U2 0 PU AMER INST PHYSICS PI WOODBURY PA CIRCULATION FULFILLMENT DIV, 500 SUNNYSIDE BLVD, WOODBURY, NY 11797-2999 SN 0734-2101 J9 J VAC SCI TECHNOL A JI J. Vac. Sci. Technol. A-Vac. Surf. Films PD SEP-OCT PY 1991 VL 9 IS 5 BP 2713 EP 2715 DI 10.1116/1.577230 PG 3 WC Materials Science, Coatings & Films; Physics, Applied SC Materials Science; Physics GA GG376 UT WOS:A1991GG37600021 ER PT J AU SHEU, EY CHEN, SH CARVALHO, BL LIN, JS CAPEL, M AF SHEU, EY CHEN, SH CARVALHO, BL LIN, JS CAPEL, M TI INTERPRETATION OF SMALL-ANGLE X-RAY-SCATTERING INTENSITY DISTRIBUTION FROM FLUCTUATING LAMELLAE IN A TERNARY-SYSTEM - SODIUM OCTYL SULFATE WATER DECANOL SO LANGMUIR LA English DT Article ID PHASES AB We have observed a clear small-angle x-ray scattering (SAXS) signal from a ternary surfactant-water-alcohol liquid mixture in a lamellar neat phase and have attributed the origin of the small-angle scattering to the fluctuation of the surfactant-alcohol bilayers. We calculated the scattering cross section by using the Debye correlation function taking into account superposition of different spatial Fourier components of the fluctuations. The theory agrees reasonably well with the experiment. If we make an ansatz that the De Gennes-Taupin persistence length of the surfactant film is inversely proportional to the most probable wavenumber of the fluctuation, we obtained the curvature elastic constant of the order of k(B)T. C1 EXXON RES & ENGN CO,ANNANDALE,NJ 08801. BROOKHAVEN NATL LAB,DEPT BIOL,UPTON,NY 11973. MIT,CTR MAT SCI & ENGN,CAMBRIDGE,MA 02139. OAK RIDGE NATL LAB,DIV SOLID STATE,OAK RIDGE,TN 37831. RP SHEU, EY (reprint author), TEXACO USA INC,RES CTR,POB 509,BEACON,NY 12508, USA. NR 10 TC 1 Z9 1 U1 2 U2 4 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 SN 0743-7463 J9 LANGMUIR JI Langmuir PD SEP PY 1991 VL 7 IS 9 BP 1895 EP 1899 DI 10.1021/la00057a013 PG 5 WC Chemistry, Multidisciplinary; Chemistry, Physical; Materials Science, Multidisciplinary SC Chemistry; Materials Science GA GG466 UT WOS:A1991GG46600013 ER PT J AU BAIKERIKAR, KG HANSEN, RS AF BAIKERIKAR, KG HANSEN, RS TI INFERENCE OF SURFACE EXCESS AND ITS HIGH-ACTIVITY LIMIT IN MONOLAYER ADSORPTION FROM INTERFACIAL-TENSION AND ACTIVITY DATA SO LANGMUIR LA English DT Article ID MERCURY-SOLUTION INTERFACE; BULK CONCENTRATION REGION; BASE ELECTROLYTE; ELECTROSORPTION; 2-BUTANOL AB For dilute aqueous solutions of organic adsorbates it has been common to assume adsorbate activity proportional to its concentration (Henry's law) to avoid activity measurements. It is shown that for concentrations up to 1 M the Henry's law "constant" K can be represented by ln K = ln K(H)-degrees - beta-c, that a surface excess based on Henry's law can hence be in error by a factor (1 - beta-c), and that this error can be as high as 30% for a saturated butanol-1 solution. Methods of estimating this correction are given. Methods for using the regular localized monolayer or Frumkin equation model to extend the experimental data range useful for estimating limiting surface excess are given. A study of the adsorption of butanol-1 and butanol-2 from saturated aqueous Na2SO4 at the mercury-electrolytic solution interface polarized to the potential of zero charge in the base electrolyte solution, based on interfacial tensions measured as a function of butanol activity, is used to illustrate these principles. A limiting surface excess 10(10)-GAMMA-m = 6.0 mol/cm2 was thus found for butanol-1, agreeing excellently with Hommelen's results for CH3(CH2)n-1OH, 6 less-than-or-equal-to n less-than-or-equal-to 10, and substantially higher than earlier reported values based on the assumption of Henry's law and simple graphical estimation of limiting tangent. C1 US DOE,AMES LAB,AMES,IA 50011. IOWA STATE UNIV SCI & TECHNOL,DEPT CHEM,AMES,IA 50011. NR 31 TC 11 Z9 11 U1 1 U2 2 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 SN 0743-7463 J9 LANGMUIR JI Langmuir PD SEP PY 1991 VL 7 IS 9 BP 1963 EP 1968 DI 10.1021/la00057a025 PG 6 WC Chemistry, Multidisciplinary; Chemistry, Physical; Materials Science, Multidisciplinary SC Chemistry; Materials Science GA GG466 UT WOS:A1991GG46600025 ER PT J AU DAVIS, JI JACOBS, RR AF DAVIS, JI JACOBS, RR TI LLNLS NEW CENTER SPURS LASER TECHNOLOGY-TRANSFER SO LASER FOCUS WORLD LA English DT Editorial Material C1 UNIV CALIF LAWRENCE LIVERMORE NATL LAB,CALEOT,LIVERMORE,CA 94550. RP DAVIS, JI (reprint author), UNIV CALIF LAWRENCE LIVERMORE NATL LAB,LASER PROGRAM,LIVERMORE,CA 94550, USA. NR 0 TC 3 Z9 3 U1 0 U2 0 PU PENNWELL PUBL CO PI NASHUA PA 5TH FLOOR TEN TARA BOULEVARD, NASHUA, NH 03062-2801 SN 0740-2511 J9 LASER FOCUS WORLD JI Laser Focus World PD SEP PY 1991 VL 27 IS 9 BP 19 EP & PG 0 WC Optics SC Optics GA GF328 UT WOS:A1991GF32800001 ER PT J AU KRATZ, TK FROST, TM ELIAS, JE COOK, RB AF KRATZ, TK FROST, TM ELIAS, JE COOK, RB TI RECONSTRUCTION OF A REGIONAL, 12,000-YR SILICA DECLINE IN LAKES BY MEANS OF FOSSIL SPONGE SPICULES SO LIMNOLOGY AND OCEANOGRAPHY LA English DT Note ID PRECIPITATION-DOMINATED LAKE; WATER AB A newly developed technique for reconstructing past dissolved reactive silica (DRSi) concentrations in lakes demonstrated an unexpected, regional decline in DRSi in northern Wisconsin lakes over the Holocene. Previously, measurements of lake DRSi, an important nutrient for certain phytoplankton, have been limited to time periods for which direct observations were available, typically years to decades. The new paleolimnological technique is based on the sizes of siliceous sponge spicules preserved in lake sediments; it shows that DRSi declined gradually, but significantly, over the past 12,000 yr in each of eight lakes cored (geometric mean decline of 35-fold; range 4.1-270-fold). Mass balance considerations show that the decline could be caused by decreases in groundwater DRSi concentration or groundwater inseepage rates, by increases in net Si sedimentation, or by a combination of these factors. Although we cannot rule out any of these possible mechanisms, the most likely seems to be decline in groundwater DRSi concentration due to differential weathering of the silicate glacial tills. With appropriate calibration, paleospicule techniques may be useful in assessing long-term silica dynamics in other regions. C1 OAK RIDGE NATL LAB,DIV ENVIRONM SCI,OAK RIDGE,TN 37831. RP KRATZ, TK (reprint author), UNIV WISCONSIN,CTR LIMNOL,TROUT LAKE STN,10810 CTY HIGHWAY N,BOULDER JCT,WI 54512, USA. NR 17 TC 10 Z9 10 U1 0 U2 2 PU AMER SOC LIMNOLOGY OCEANOGRAPH PI LAWRENCE PA 810 EAST 10TH ST, LAWRENCE, KS 66044-8897 SN 0024-3590 J9 LIMNOL OCEANOGR JI Limnol. Oceanogr. PD SEP PY 1991 VL 36 IS 6 BP 1244 EP 1249 PG 6 WC Limnology; Oceanography SC Marine & Freshwater Biology; Oceanography GA GW015 UT WOS:A1991GW01500018 ER PT J AU FENSKE, GR HU, R BALDO, PM ERCK, RA ERDEMIR, A LEE, RH BUSCH, DE NICHOLS, FA REHN, LE AF FENSKE, GR HU, R BALDO, PM ERCK, RA ERDEMIR, A LEE, RH BUSCH, DE NICHOLS, FA REHN, LE TI ION-BEAM MIXING OF FE/B LAYERS FOR TRIBOLOGICAL APPLICATIONS SO LUBRICATION ENGINEERING LA English DT Article AB Ion-beam mixing of iron and boron deposited layers was investigated as a technique to produce improved tribological coatings on steel substrates. Analysis of the kinetics of the ion-mixing process indicated that processing temperatures between 300 and 450-degrees-C was required to achieve mixing of iron and boron multilayered coatings. During film deposition, it is critical to avoid deposition processes such as RF sputtering that trap large quantities of inert gases in the growing films and form blisters during subsequent ion mixing at elevated temperatures. Tribological evaluation of annealed and ion-mixed coatings indicated that the major effect of the ion mixing is the formation of hard, wear-resistant, polycrystalline Fe2B and Fe3B phases at 450-degrees-C and amorphous layers at 300-degrees-C. Under partially lubricated conditions, the hard phases increase the duration of a low-friction (coefficient of friction < 0.2) regime by reducing wear, thereby maintaining a low surface roughness. Under boundary-lubrication conditions, reduced wear was observed in tests on ion-mixed samples and was found to be dependent on the humidity in the test environment. RP FENSKE, GR (reprint author), ARGONNE NATL LAB,DIV MAT & COMPONENTS TECHNOL,ARGONNE,IL 60439, USA. NR 0 TC 1 Z9 1 U1 0 U2 0 PU SOC TRIBOLOGISTS & LUBRICATION ENGINEERS PI PARK RIDGE PA 838 BUSSE HIGHWAY, PARK RIDGE, IL 60068 SN 0024-7154 J9 LUBR ENG JI Lubric. Eng. PD SEP PY 1991 VL 47 IS 9 BP 779 EP 786 PG 8 WC Engineering, Mechanical SC Engineering GA GF205 UT WOS:A1991GF20500009 ER PT J AU WAN, XM FU, TC SMITH, PH BRAINARD, JR LONDON, RE AF WAN, XM FU, TC SMITH, PH BRAINARD, JR LONDON, RE TI MAGNETIC-RESONANCE-IMAGING STUDY OF THE RAT CEREBRAL VENTRICULAR SYSTEM UTILIZING INTRACEREBRALLY ADMINISTERED CONTRAST AGENTS SO MAGNETIC RESONANCE IN MEDICINE LA English DT Article ID SUBCELLULAR-LOCALIZATION; MR CISTERNOGRAPHY; BRAIN-TUMORS; SIALIC-ACID; GADOLINIUM C1 NATL TAIWAN UNIV,COLL MED,DEPT PHYSIOL,TAIPEI 10018,TAIWAN. UNIV CALIF LOS ALAMOS SCI LAB,INC-4,LOS ALAMOS,NM 87545. RP WAN, XM (reprint author), NIEHS,MOLEC BIOPHYS LAB,POB 12233,RES TRIANGLE PK,NC 27709, USA. NR 28 TC 17 Z9 18 U1 0 U2 2 PU WILLIAMS & WILKINS PI BALTIMORE PA 351 WEST CAMDEN ST, BALTIMORE, MD 21201-2436 SN 0740-3194 J9 MAGNET RESON MED JI Magn.Reson.Med. PD SEP PY 1991 VL 21 IS 1 BP 97 EP 106 DI 10.1002/mrm.1910210112 PG 10 WC Radiology, Nuclear Medicine & Medical Imaging SC Radiology, Nuclear Medicine & Medical Imaging GA GD987 UT WOS:A1991GD98700010 PM 1943681 ER PT J AU NEEMAN, M FREYER, JP SILLERUD, LO AF NEEMAN, M FREYER, JP SILLERUD, LO TI A SIMPLE METHOD FOR OBTAINING CROSS-TERM-FREE IMAGES FOR DIFFUSION ANISOTROPY STUDIES IN NMR MICROIMAGING SO MAGNETIC RESONANCE IN MEDICINE LA English DT Note ID INTRAVOXEL INCOHERENT MOTIONS; GRADIENT SPIN-ECHO; MOLECULAR-DIFFUSION; MR; COEFFICIENTS; PERFUSION; INVIVO; WATER C1 UNIV CALIF LOS ALAMOS SCI LAB,DIV LIFE SCI,BIOMED NMR FACIL,LOS ALAMOS,NM 87545. RP NEEMAN, M (reprint author), UNIV CALIF LOS ALAMOS SCI LAB,CELLULAR & MOLEC BIOL GRP,LOS ALAMOS,NM 87545, USA. RI Neeman, Michal/A-8264-2008 OI Neeman, Michal/0000-0002-6296-816X NR 19 TC 127 Z9 127 U1 1 U2 4 PU WILLIAMS & WILKINS PI BALTIMORE PA 351 WEST CAMDEN ST, BALTIMORE, MD 21201-2436 SN 0740-3194 J9 MAGNET RESON MED JI Magn.Reson.Med. PD SEP PY 1991 VL 21 IS 1 BP 138 EP 143 DI 10.1002/mrm.1910210117 PG 6 WC Radiology, Nuclear Medicine & Medical Imaging SC Radiology, Nuclear Medicine & Medical Imaging GA GD987 UT WOS:A1991GD98700015 PM 1943671 ER PT J AU HOLLIBAUGH, JT BUDDEMEIER, RW SMITH, SV AF HOLLIBAUGH, JT BUDDEMEIER, RW SMITH, SV TI CONTRIBUTIONS OF COLLOIDAL AND HIGH-MOLECULAR-WEIGHT DISSOLVED MATERIAL TO ALKALINITY AND NUTRIENT CONCENTRATIONS IN SHALLOW MARINE AND ESTUARINE SYSTEMS SO MARINE CHEMISTRY LA English DT Article ID CATALYTIC-OXIDATION METHOD; TOTAL CARBON-DIOXIDE; ORGANIC-MATTER; FRESH-WATER; SALT-MARSH; POTENTIOMETRIC TITRATION; BACTERIOPLANKTON GROWTH; EQUATORIAL PACIFIC; SEAWATER CULTURES; CONTINENTAL-SHELF AB We investigated the contribution of high molecular weight and colloidal material to total alkalinity, dissolved organic and dissolved inorganic nutrient concentrations in samples from a temperate nearshore environment (Tomales Bay, California), a tropical nearshore environment, (Australia Institute of Marine Science, Townsville, Queensland, Australia) and a coral reef environment (Davies Reef, Australia). Amicon UM-10 ultrafilters (10 000 daltons or 3 nm nominal cutoff) were used to remove high molecular weight material, including colloids, from conventionally filtered samples (Whatman GF/C glass fiber filters, Tomales Bay; or 0.45-mu-m pore size mixed cellulose ester Millipore filters, Australia). We found no evidence of a high molecular weight component of total seawater alkalinity. Ultrafiltration removed 3% of reactive phosphorus, 71% of organic phosphorus, 28% of organic carbon, 1% of ammonium and 27% of organic nitrogen from GF/C filtrates of Tomales Bay samples. Reactive silicate and nitrate plus nitrite concentrations were unaffected by ultrafiltration. Microscopic examination of Tomales Bay samples revealed that 75-100% of the bacterioplankton present in the unaltered sample passed through the GF/C filter. Calculations based on published values of the carbon content and carbon:nitrogen:phosphorus ratio of bacterioplankton cells indicated that their contribution to organic carbon retained by the ultrafilter was negligible. However, bacterioplankton accounted for 12% of the organic nitrogen and 27% of the organic phosphorus in GF/C filtrates and 29% and 39% of the organic nitrogen and organic phosphorus, respectively, removed by ultrafiltration. Organic phosphorus removed by filtration through GF/F glass fiber filters, through 0.22-mu-m pore size Millipore (mixed cellulose ester) filters, or through 1.0 or 0.2-mu-m pore size Nucleopore (polycarbonate) filters was equivalent to the calculated phosphorus content of the bacteria removed by the same filters. These results suggest that bacterial cells are an important component of traditionally defined high molecular weight dissolved organic matter, and that the composition of this material should reflect the composition of bacterial cells. Furthermore, bacterial cells are an important component of the net hydrographic export of organic phosphorus, and to a lesser extent organic nitrogen, from Tomales Bay. C1 UNIV HAWAII,HAWAII INST MARINE BIOL,HONOLULU,HI 96822. UNIV CALIF LAWRENCE LIVERMORE NATL LAB,LIVERMORE,CA 94550. RP HOLLIBAUGH, JT (reprint author), SAN FRANCISCO STATE UNIV,TIBURON CTR,POB 855,TIBURON,CA 94920, USA. NR 71 TC 16 Z9 17 U1 3 U2 12 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0304-4203 J9 MAR CHEM JI Mar. Chem. PD SEP PY 1991 VL 34 IS 1-2 BP 1 EP 27 DI 10.1016/0304-4203(91)90011-K PG 27 WC Chemistry, Multidisciplinary; Oceanography SC Chemistry; Oceanography GA GG736 UT WOS:A1991GG73600001 ER PT J AU MUNK, WH WATKINS, J AF MUNK, WH WATKINS, J TI DOHERTY LECTURE - IS THERE TIME TO MEASURE (NOT SPECULATE) OCEAN WARMING BEFORE MAKING POLICY SO MARINE TECHNOLOGY SOCIETY JOURNAL LA English DT Article C1 US DOE,WASHINGTON,DC. RP MUNK, WH (reprint author), UNIV CALIF SAN DIEGO,SCRIPPS INST OCEANOG,LA JOLLA,CA 92093, USA. NR 0 TC 1 Z9 1 U1 0 U2 2 PU MARINE TECHNOLOGY SOC INC PI WASHINGTON PA 1828 L ST NW 9TH FLOOR, WASHINGTON, DC 20036 SN 0025-3324 J9 MAR TECHNOL SOC J JI Mar. Technol. Soc. J. PD FAL PY 1991 VL 25 IS 3 BP 52 EP 57 PG 6 WC Engineering, Ocean; Oceanography SC Engineering; Oceanography GA GQ928 UT WOS:A1991GQ92800009 ER PT J AU SMITH, RD LOO, JA LOO, RRO BUSMAN, M UDSETH, HR AF SMITH, RD LOO, JA LOO, RRO BUSMAN, M UDSETH, HR TI PRINCIPLES AND PRACTICE OF ELECTROSPRAY IONIZATION - MASS-SPECTROMETRY FOR LARGE POLYPEPTIDES AND PROTEINS SO MASS SPECTROMETRY REVIEWS LA English DT Review ID CAPILLARY ZONE ELECTROPHORESIS; FAST-ATOM-BOMBARDMENT; SULFONATED AZO DYES; PERFORMANCE LIQUID-CHROMATOGRAPHY; MULTIPLY CHARGED IONS; AMINO-ACID-SEQUENCE; ATMOSPHERIC-PRESSURE; CYTOCHROME-C; CONFORMATIONAL-CHANGES; LARGE MOLECULES RP SMITH, RD (reprint author), PACIFIC NW LAB, DEPT CHEM SCI, CHEM METHODS & SEPARAT GRP, MAIL STOP P8-19, RICHLAND, WA 99352 USA. RI Smith, Richard/J-3664-2012 OI Smith, Richard/0000-0002-2381-2349 NR 325 TC 578 Z9 580 U1 7 U2 93 PU WILEY-BLACKWELL PI MALDEN PA COMMERCE PLACE, 350 MAIN ST, MALDEN 02148, MA USA SN 0277-7037 J9 MASS SPECTROM REV JI Mass Spectrom. Rev. PD SEP PY 1991 VL 10 IS 5 BP 359 EP 451 DI 10.1002/mas.1280100504 PG 93 WC Spectroscopy SC Spectroscopy GA HK167 UT WOS:A1991HK16700003 ER PT J AU GRIEWANK, A JONGEN, HT KWONG, MK AF GRIEWANK, A JONGEN, HT KWONG, MK TI THE EQUIVALENCE OF STRICT CONVEXITY AND INJECTIVITY OF THE GRADIENT IN BOUNDED LEVEL SETS SO MATHEMATICAL PROGRAMMING LA English DT Article DE CONVEXITY; INJECTIVITY; GENERALIZED GRADIENT; SUPPORTING HYPERPLANE; AFFINE INVARIANCE AB It is shown that Lipschitzian functions are strictly convex if and only if their generalized gradients are disjoint at distinct interior points of a given bounded level set. C1 RHEIN WESTFAL TH AACHEN,LEHRSTUHL MATH C,W-5100 AACHEN,GERMANY. RP GRIEWANK, A (reprint author), ARGONNE NATL LAB,DIV MATH & COMP SCI,ARGONNE,IL 60439, USA. OI Griewank, Andreas/0000-0001-9839-1473 NR 7 TC 0 Z9 0 U1 0 U2 0 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0025-5610 J9 MATH PROGRAM JI Math. Program. PD SEP PY 1991 VL 51 IS 2 BP 273 EP 278 DI 10.1007/BF01586939 PG 6 WC Computer Science, Software Engineering; Operations Research & Management Science; Mathematics, Applied SC Computer Science; Operations Research & Management Science; Mathematics GA GG721 UT WOS:A1991GG72100008 ER PT J AU BAJURA, RA WEBB, HA AF BAJURA, RA WEBB, HA TI THE MARRIAGE OF GAS-TURBINES AND COAL SO MECHANICAL ENGINEERING LA English DT Article RP BAJURA, RA (reprint author), US DOE,MORGANTOWN ENERGY TECHNOL CTR,MORGANTOWN,WV 26505, USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU ASME-AMER SOC MECHANICAL ENG PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 SN 0025-6501 J9 MECH ENG JI Mech. Eng. PD SEP PY 1991 VL 113 IS 9 BP 58 EP 63 PG 6 WC Engineering, Mechanical SC Engineering GA GD937 UT WOS:A1991GD93700009 ER PT J AU FRITZ, G TANO, K MITRA, S KAINA, B AF FRITZ, G TANO, K MITRA, S KAINA, B TI INDUCIBILITY OF THE DNA-REPAIR GENE ENCODING O6-METHYLGUANINE-DNA METHYLTRANSFERASE IN MAMMALIAN-CELLS BY DNA-DAMAGING TREATMENTS SO MOLECULAR AND CELLULAR BIOLOGY LA English DT Article ID CHINESE-HAMSTER CELLS; O-6-ALKYLGUANINE-DNA ALKYLTRANSFERASE ACTIVITY; RAT-LIVER EXTRACTS; MESSENGER-RNA; O-6-METHYLGUANINE-DNA METHYLTRANSFERASE; ADAPTIVE RESPONSE; ALKYLATING-AGENTS; ESCHERICHIA-COLI; METHYLATING AGENTS; HUMAN-TUMOR AB The inducibility of the mammalian O6-methylguanine-DNA methyltransferase (MGMT) gene encoding the MGMT protein (EC 2.1.1.63) responsible for removal of the procarcinogenic and promutagenic lesion O6-alkylguanine from DNA was examined by an analysis of transcription of the MGMT gene following exposure of repair-competent (Mex+) and repair-deficient (Mex-) cells to N-methyl-N'-nitro-N-nitrosoguanidine (MNNG). While human and rodent Mex- cells (CHO-9, V79, HeLa MR) showed no detectable MGMT mRNA despite the presence of the gene in their genome, the amount of it in several Mex+ lines (NIH 3T3, HeLa S3, HepG2) paralled their MGMT activity. However, none of these cell lines showed an increase in the MGMT mRNA level after treatment with various concentrations of MNNG. In contrast, MNNG-treated rat hepatoma cells, H4IIE and FTO-2B, both Mex+, had three- to fivefold more MGMT mRNA than the corresponding untreated controls as measured 12 to 72 h after alkylation. N-Methyl-N-nitrosourea, methyl methanesulfonate, N-hydroxyethyl-N-chloroethylnitrosourea, UV light, and X rays caused a similar accumulation of MGMT mRNA in rat hepatoma cells. Studies with inhibitors of RNA and protein synthesis indicate that the induced increase in the amount of MGMT mRNA was due to enhanced transcription of the gene. Furthermore, they revealed the turnover of the MGMT mRNA to be relatively low (half-life, > 7 h). Mutagen-induced increase of transcription of MGMT mRNA in H4IIE cells was accompanied by elevation of MGMT repair activity and resulted in reduction of mutation frequency after a challenge dose of MNNG. Although induction of MGMT mRNA transcription has been observed in two rodent hepatoma cell lines so far, this appears to be the first demonstration of inducibility of a mammalian gene encoding a clearly defined DNA repair function. The transcriptional activation of the MGMT gene protects cells from the mutagenic effects of methylating agents. C1 KERNFORSCHUNGSZENTRUM KARLSRUHE GMBH,INST GENET & TOXICOL,POSTFACH 3640,W-7500 KARLSRUHE 1,GERMANY. UNIV TENNESSEE,GRAD SCH BIOMED SCI,KNOXVILLE,TN 37996. OAK RIDGE NATL LAB,DIV BIOL,OAK RIDGE,TN 37831. FU NCI NIH HHS [CA 31721] NR 62 TC 129 Z9 130 U1 1 U2 1 PU AMER SOC MICROBIOLOGY PI WASHINGTON PA 1325 MASSACHUSETTS AVENUE, NW, WASHINGTON, DC 20005-4171 SN 0270-7306 J9 MOL CELL BIOL JI Mol. Cell. Biol. PD SEP PY 1991 VL 11 IS 9 BP 4660 EP 4668 PG 9 WC Biochemistry & Molecular Biology; Cell Biology SC Biochemistry & Molecular Biology; Cell Biology GA GC396 UT WOS:A1991GC39600043 PM 1875945 ER PT J AU ROBERTO, J AF ROBERTO, J TI MRS 2000 - A VISION OF SERVICE TO THE MATERIALS COMMUNITY SO MRS BULLETIN LA English DT Letter RP ROBERTO, J (reprint author), OAK RIDGE NATL LAB,OAK RIDGE,TN 37831, USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU MATERIALS RESEARCH SOCIETY PI PITTSBURGH PA 9800 MC KNIGHT ROAD SUITE 327, PITTSBURGH, PA 15237 SN 0883-7694 J9 MRS BULL JI MRS Bull. PD SEP PY 1991 VL 16 IS 9 BP 4 EP 4 PG 1 WC Materials Science, Multidisciplinary; Physics, Applied SC Materials Science; Physics GA GF320 UT WOS:A1991GF32000001 ER PT J AU TRAVIS, CC WANG, LA WAEHNER, MJ AF TRAVIS, CC WANG, LA WAEHNER, MJ TI QUANTITATIVE CORRELATION OF CARCINOGENIC POTENCY WITH 4 DIFFERENT CLASSES OF SHORT-TERM TEST DATA SO MUTAGENESIS LA English DT Article ID NATIONAL-TOXICOLOGY-PROGRAM; ANIMAL BIOASSAYS; CHRONOLOGICAL SUPPLEMENT; CHEMICAL-STRUCTURE; SALMONELLA; PREDICTION; MUTAGENS; RODENTS AB The search for a short-term mutagenicity test to identify potential carcinogens has yielded over 100 assay systems, including the Ames test. This paper continues the investigation of Travis et al. into the prediction of carcinogenic potency of known mouse carcinogens using different classes of short-term toxicologic data. We used four classes of short-term test data (mutation, toxicity, reproduction and tumorigenicity) from the Registry of Toxic Effects of Chemical Substances (RTECS) database. We conclude that mutation data alone are poor predictors of carcinogenic potency, accounting for only 21% of the observed variability in experimentally-determined mouse TD50 values. We further conclude that batteries of toxicologic data containing varying types of short-term data are excellent predictors of the carcinogenic potency of known mouse carcinogens: four types of short-term data account for 82% of the observed variability in experimentally-obtained mouse TD50 values. By using all available toxicological data, we obtained a strong correlation between toxicologic assay results and carcinogenic potency of known mouse carcinogens. RP TRAVIS, CC (reprint author), OAK RIDGE NATL LAB,DIV HLTH & SAFETY RES,OFF RISK ANAL,OAK RIDGE,TN 37831, USA. NR 23 TC 8 Z9 8 U1 0 U2 1 PU OXFORD UNIV PRESS UNITED KINGDOM PI OXFORD PA WALTON ST JOURNALS DEPT, OXFORD, ENGLAND OX2 6DP SN 0267-8357 J9 MUTAGENESIS JI Mutagenesis PD SEP PY 1991 VL 6 IS 5 BP 353 EP 360 DI 10.1093/mutage/6.5.353 PG 8 WC Genetics & Heredity; Toxicology SC Genetics & Heredity; Toxicology GA GG058 UT WOS:A1991GG05800004 PM 1795638 ER PT J AU TANO, K SHIOTA, S REMACK, JS BRENT, TP BIGNER, DD MITRA, S AF TANO, K SHIOTA, S REMACK, JS BRENT, TP BIGNER, DD MITRA, S TI THE ORIGIN OF O6-METHYLGUANINE-DNA METHYLTRANSFERASE IN CHINESE-HAMSTER OVARY CELLS TRANSFECTED WITH HUMAN DNA SO MUTATION RESEARCH LA English DT Article DE O6-METHYLGUANINE-DNA METHYLTRANSFERASE; CHO CELL; MER-/MEX-; MGMT MESSENGER RNA ID O-6-ALKYLGUANINE-DNA ALKYLTRANSFERASE; O-6-METHYLGUANINE-DNA METHYLTRANSFERASE; ALKYLATING-AGENTS; HUMAN-TUMOR; EXPRESSION; REPAIR; GENE; TRANSFORMATION; PURIFICATION; PREVENTION AB Transfection of Chinese hamster ovary (CHO) cells with human DNA has been shown in several laboratories to produce clones which stably express the DNA-repair protein, O6-methylguanine-DNA methyltransferase (MGMT), that is lacking in the parent cell lines (Mex- phenotype). We have investigated the genetic origin of the MGMT in a number of such MGMT-positive (Mex+) clones by using human MGMT cDNA and anti-human MGMT antibodies as probes. None of the five independently isolated Mex+ lines has human MGMT gene sequences. Immunoblot analysis confirmed the absence of the human protein in the extracts of these cells. The MGMT mRNA in the lines that express low levels of MGMT (0.6-1.4 x 10(4) molecules/cell) is of the same size (1.1 kb) as that present in hamster liver. One cell line, GC-1, with a much higher level of MGMT (4 x 10(4) molecules/cell) has two MGMT mRNAs, a major species of 1.3 kb and a minor species of 1.8 kb. It has also two MGMT polypeptides (32 and 28 kDa), both of which are larger than the 25 kDa MGMT present in hamster liver and other Mex+ transfectants. These results indicate that the MGMT in all Mex+ CHO cell clones is encoded by the endogenous gene. While spontaneous activation of the MGMT gene cannot be ruled out in the Mex+ cell clones, the intervention of human DNA sequences may be responsible for activation of the endogenous gene in the GC-1 line. C1 ST JUDE CHILDRENS RES HOSP, DEPT BIOCHEM & CLIN PHARMACOL, MEMPHIS, TN 38101 USA. OAK RIDGE NATL LAB, DIV BIOL, OAK RIDGE, TN 37831 USA. DUKE UNIV, MED CTR, DEPT PATHOL, DURHAM, NC 27710 USA. RP TANO, K (reprint author), UNIV TENNESSEE, GRAD SCH BIOMED SCI, OAK RIDGE, TN 37831 USA. FU NCI NIH HHS [CA 36888, CA 14799, CA 31721] NR 34 TC 14 Z9 14 U1 0 U2 0 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0921-8262 J9 MUTAT RES JI Mutat. Res. PD SEP PY 1991 VL 255 IS 2 BP 175 EP 182 DI 10.1016/0921-8777(91)90051-P PG 8 WC Genetics & Heredity; Toxicology SC Genetics & Heredity; Toxicology GA GF754 UT WOS:A1991GF75400006 PM 1922149 ER PT J AU AMES, BN GOLD, LS AF AMES, BN GOLD, LS TI ENDOGENOUS MUTAGENS AND THE CAUSES OF AGING AND CANCER SO MUTATION RESEARCH LA English DT Article DE MUTATION; CANCER; AGING; PROMOTION ID OXIDATIVE DNA DAMAGE; HUMAN-BLOOD PLASMA; INTERCELLULAR COMMUNICATION; CHEMICAL CARCINOGENESIS; ANTIOXIDANT ACTIVITY; RODENT CARCINOGENS; CELL-PROLIFERATION; EPIGENETIC DEFECTS; OXYGEN RADICALS; POTENTIAL ROLE AB A very large oxidative damage rate to DNA occurs as part of normal metabolism. In each rat cell the steady-state level is estimated to be about 10(6) oxidative adducts and about 10(5) new adducts are formed daily. It is argued that this endogenous DNA damage is a major contributor to aging and the degenerative diseases of aging, such as cancer. The oxidative damage rate in mammalian species with a high metabolic rate, short life span, and high age-specific cancer rate is much higher than the rate in humans, a long-lived creature with a lower metabolic rate and a lower age-specific cancer rate. It is argued that deficiency of micronutrients, such as dietary antioxidants or folate, is a major contributor to human cancer and degenerative diseases. Understanding the role of mitogenesis in mutagenesis is critical for clarifying the mechanisms of carcinogenesis and interpreting high-dose animal cancer tests. High-dose animal cancer tests have been done mainly on synthetic industrial chemicals, yet almost all of the chemicals humans are exposed to are natural. About half of natural chemicals tested in high-dose animal cancer tests are rodent carcinogens, a finding that is consistent with the view that high-dose tests frequently increase mitogenesis rates. Animals have numerous defenses against toxins that make them very well buffered against low doses of almost all toxins, whether synthetic or natural. C1 UNIV CALIF BERKELEY,LAWRENCE BERKELEY LAB,DIV CELL & MOLEC BIOL,BERKELEY,CA 94720. RP AMES, BN (reprint author), UNIV CALIF BERKELEY,DIV BIOCHEM & MOLEC BIOL,BARKER HALL,BERKELEY,CA 94720, USA. FU NCI NIH HHS [CA39910]; NIEHS NIH HHS [ESO1896] NR 120 TC 588 Z9 605 U1 9 U2 35 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0921-8262 J9 MUTAT RES PD SEP-OCT PY 1991 VL 250 IS 1-2 BP 3 EP 16 DI 10.1016/0027-5107(91)90157-J PG 14 WC Genetics & Heredity; Toxicology SC Genetics & Heredity; Toxicology GA GL878 UT WOS:A1991GL87800001 PM 1944345 ER PT J AU BENDER, MA MOORE, RC AF BENDER, MA MOORE, RC TI DNA POLYMERASE-DELTA MEDIATES INCREASE IN EXCHANGE PRODUCTION BY X-RADIATION IN HUMAN-LYMPHOCYTES MOVING FROM G0 TO G1 SO MUTATION RESEARCH LA English DT Article DE DNA POLYMERASE-DELTA; POLYMERASE-DELTA; LYMPHOCYTES, HUMAN PERIPHERAL BLOOD; PHYTOHEMAGGLUTININ STIMULATION; RADIATION CLASTOGENESIS; CLASTOGENESIS, RADIATION; APHIDICOLIN ID CHROMOSOME-ABERRATIONS; RAY; ALPHA AB Earlier work of several laboratories established that the yields of radiation-induced ring and dicentric chromosomes are greater when human peripheral blood lymphocytes are irradiated in GH1 some hours after phytohemagglutinin stimulation than if they are irradiated in G0 before stimulation. Post-treatment of lymphocytes irradiated in G0 with the DNA polymerase inhibitor aphidicolin, which is effective against both pol-alpha and pol-delta, produces a similar increase in ring and dicentric yield. We found that aphidicolin post-treatment was much less effective in increasing ring and dicentric yield increases in cells irradiated in G1 four to five hours after stimulation. Because we had earlier found specific inhibitors of DNA pol alpha-ineffective in producing increased yields in either G0 or G1 lymphocytes, we conclude that much of the G0 to G1 increase in yields is mediated by pol-delta. C1 PETER MACCALLUM CANC INST,INST CANC,MELBOURNE,VIC 3000,AUSTRALIA. RP BENDER, MA (reprint author), BROOKHAVEN NATL LAB,DEPT MED,UPTON,NY 11973, USA. NR 9 TC 4 Z9 4 U1 0 U2 0 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0921-8262 J9 MUTAT RES PD SEP-OCT PY 1991 VL 250 IS 1-2 BP 319 EP 324 DI 10.1016/0027-5107(91)90187-S PG 6 WC Genetics & Heredity; Toxicology SC Genetics & Heredity; Toxicology GA GL878 UT WOS:A1991GL87800031 PM 1944347 ER PT J AU SHELBY, MD GUTIERREZESPELETA, GA GENEROSO, WM MCFEE, AF AF SHELBY, MD GUTIERREZESPELETA, GA GENEROSO, WM MCFEE, AF TI MOUSE DOMINANT LETHAL AND BONE-MARROW MICRONUCLEUS STUDIES ON METHYL VINYL SULFONE AND DIVINYL SULFONE SO MUTATION RESEARCH LA English DT Article DE MICRONUCLEUS STUDIES; METHYL VINYL SULFONE; DIVINYL SULFONE; DOMINANT LETHAL MUTATIONS; BONE MARROW ERYTHROCYTES; ACRYLAMIDE ID MALE-MICE; GERM-CELLS; ACRYLAMIDE; CARCINOGENICITY; MUTAGENICITY; SALMONELLA; ASSAYS; DNA AB Methyl vinyl sulfone and divinyl sulfone were tested for the induction of dominant lethal mutations and micronucleated bone-marrow erythrocytes in male mice. These chemicals were chosen for study because of their similarities in structure and chemical reactivity to acrylamide which is known to induce both effects. Following administration of the test compounds by intraperitoneal injection at the maximum tolerated doses, no evidence of induced dominant lethal mutations or micronucleated bone-marrow cells was observed for either chemical. It is concluded that structures and Michael reactivities similar to acrylamide are not sufficient to impart similar in vivo genetic toxicity to MVS and DVS. C1 OAK RIDGE ASSOCIATED UNIV,OAK RIDGE,TN 37831. OAK RIDGE NATL LAB,DIV BIOL,OAK RIDGE,TN 37831. RP SHELBY, MD (reprint author), NIEHS,POB 12233,RES TRIANGLE PK,NC 27709, USA. FU NIEHS NIH HHS [Y01-ES-20100, Y01-ES-20085] NR 17 TC 8 Z9 8 U1 1 U2 3 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0921-8262 J9 MUTAT RES PD SEP-OCT PY 1991 VL 250 IS 1-2 BP 431 EP 437 DI 10.1016/0027-5107(91)90199-X PG 7 WC Genetics & Heredity; Toxicology SC Genetics & Heredity; Toxicology GA GL878 UT WOS:A1991GL87800043 PM 1944356 ER PT J AU GENEROSO, WM SHOURBAJI, AG PIEGORSCH, WW BISHOP, JB AF GENEROSO, WM SHOURBAJI, AG PIEGORSCH, WW BISHOP, JB TI DEVELOPMENTAL RESPONSE OF ZYGOTES EXPOSED TO SIMILAR MUTAGENS SO MUTATION RESEARCH LA English DT Article DE FETAL ANOMALIES; ZYGOTES; METHYL METHANESULFONATE; DIMETHYL SULFATE; DIETHYL SULFATE ID ETHYLENE-OXIDE; FETAL ANOMALIES; DEATH; MALFORMATIONS; MOUSE; MICE AB Exposure of mouse zygotes to ethylene oxide (EtO) or ethyl methanesulfonate (EMS) led to high incidences of fetal death and of certain classes of fetal malformations (Generoso et al., 1987, 1988; Rutledge and Generoso, 1989). These effects were not associated with induced chromosomal aberrations (Katoh et al., 1989) nor are they likely to be caused by gene mutations (Generoso et al., 1990). Nevertheless, the anomalies observed in these studies resemble the large class of stillbirths and sporadic defects in humans that are of unknown etiology, such as cleft palate, omphalocoel, clubfoot, hydrops and stillbirths (Czeizel, 1985; Oakley, 1986). Therefore, we continue to study the possible mechanisms relating to induction of these types of zygote-derived anomalies in mice. Effects of zygote exposure to the compounds methyl methanesulfonate (MMS), dimethyl sulfate (DMS), and diethyl sulfate (DES), which have similar DNA-binding properties as EtO and EMS, were studied. DMS and DES, but not MMS, induced effects that are similar to those induced by EtO and EMS. Thus, no site-specific alkylation product was identifiable as the critical target for these zygote-derived anomalies. We speculate that the developmental anomalies arose as a result of altered programming of gene expression during embryogenesis. C1 NIEHS,RES TRIANGLE PK,NC 27709. RP GENEROSO, WM (reprint author), OAK RIDGE NATL LAB,DIV BIOL,POB 2009,OAK RIDGE,TN 37738, USA. OI Piegorsch, Walter/0000-0003-2725-5604 FU NIEHS NIH HHS [Y01-ES-20085] NR 22 TC 28 Z9 29 U1 0 U2 2 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0921-8262 J9 MUTAT RES PD SEP-OCT PY 1991 VL 250 IS 1-2 BP 439 EP 446 DI 10.1016/0027-5107(91)90200-8 PG 8 WC Genetics & Heredity; Toxicology SC Genetics & Heredity; Toxicology GA GL878 UT WOS:A1991GL87800044 PM 1944357 ER PT J AU WASSOM, JS VONHALLE, ES AF WASSOM, JS VONHALLE, ES TI MUTATION-RESEARCH AND THE LITERATURE OF GENETIC TOXICOLOGY - ANOTHER MILESTONE SO MUTATION RESEARCH LA English DT Editorial Material RP WASSOM, JS (reprint author), OAK RIDGE NATL LAB,DIV HLTH & SAFETY RES,BIOMED & ENVIRONM INFORMAT ANAL SECT,OAK RIDGE,TN 37831, USA. NR 2 TC 3 Z9 3 U1 0 U2 0 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0921-8262 J9 MUTAT RES PD SEP-OCT PY 1991 VL 250 IS 1-2 BP 499 EP 502 DI 10.1016/0027-5107(91)90206-4 PG 4 WC Genetics & Heredity; Toxicology SC Genetics & Heredity; Toxicology GA GL878 UT WOS:A1991GL87800050 PM 1944362 ER PT J AU TOTH, R MILLER, RM JARSTFER, AG ALEXANDER, T BENNETT, EL AF TOTH, R MILLER, RM JARSTFER, AG ALEXANDER, T BENNETT, EL TI THE CALCULATION OF INTRARADICAL FUNGAL BIOMASS FROM PERCENT COLONIZATION IN VESICULAR-ARBUSCULAR MYCORRHIZAE SO MYCOLOGIA LA English DT Article DE VAM; VESICULAR-ARBUSCULAR MYCORRHIZAE; MYCORRHIZAE; MYCORRHIZAE; BIOMASS ID INFECTION; SOIL; ROOTS; DEGENERATION; DYNAMICS; SOYBEANS; CHITIN AB Root colonization as estimated by the line intersect method yields a quantitative value which is related to the extent of intercellular hyphal development and the proportion of the cortex occupied by cells with arbuscules. Hence, by knowing the amount of mycorrhizal colonization, we should be able to predict fungal biovolume provided the relationship (constant) between colonization and fungal biovolume is known. We have used data from morphometric cytological studies of mycorrhiza of Allium cepa and a chitin assay for Agropyron smithii roots to determine how colonization and fungus biovolume are related in order to derive the constant (K(f)). We show that by using K(f) and measuring root radius and colonized root length, we can calculate fungal biovolume and, hence, fungal biomass for an entire root system. We show that the regression model (P < 0.0001) for the calculated mycorrhizal fungal biomass value (x) and the actual measured value as determined by the chitin method (y) are good predictors of biomass (y = 0.22 + 1.22x; R2 = 0.81). Moreover, we show that when fungal biomass is expressed as percent of the root system, the relationship improves (y = 0.21 + 1.09x; R2 = 0.89). This study indicates that it is possible to calculate intraradical mycorrhizal fungal biomass from colonization data; a preliminary K(f) value of 0.06 is proposed. C1 ARGONNE NATL LAB,DIV ENVIRONM RES,ARGONNE,IL 60439. RP TOTH, R (reprint author), NO ILLINOIS UNIV,DEPT BIOL SCI,DE KALB,IL 60115, USA. NR 25 TC 19 Z9 19 U1 1 U2 6 PU NEW YORK BOTANICAL GARDEN PI BRONX PA PUBLICATIONS DEPT, BRONX, NY 10458 SN 0027-5514 J9 MYCOLOGIA JI Mycologia PD SEP-OCT PY 1991 VL 83 IS 5 BP 553 EP 558 DI 10.2307/3760210 PG 6 WC Mycology SC Mycology GA GQ097 UT WOS:A1991GQ09700003 ER PT J AU PHELPS, ME AF PHELPS, ME TI PET - A BIOLOGICAL IMAGING TECHNIQUE SO NEUROCHEMICAL RESEARCH LA English DT Article DE PET; BRAIN; GLUCOSE METABOLISM; NEUROTRANSMITTERS; CEREBRAL FUNCTION; NEUROPSYCHIATRIC DISEASE ID POSITRON EMISSION TOMOGRAPHY; CEREBRAL GLUCOSE-UTILIZATION; PROTEIN-SYNTHESIS RATES; HUMAN VISUAL-CORTEX; LIVING HUMAN-BRAIN; METABOLIC-RATE; HUNTINGTONS-DISEASE; SURGICAL-TREATMENT; RECEPTOR-BINDING; INVIVO AB Like in vivo autoradiography, PET provides a means to image and measure rates of biological processes throughout the distributed and interrelated systems of the entire living brain. In addition, both techniques can track and image the functional interactions of the brain with other systems throughout the entire body. Technological advances are yielding higher image spatial resolution and "Electronic generators" for automated synthesis of positiron labeled compounds. The expanding number of labeled compounds (> 500) is providing a growing number of biological assays (i.e., substrate metabolism, pre and post synaptic processes, enzyme activity, interaction of medical and illicit drugs with biological systems of the brain, immune system, membrane processes). Studies of normal cerebral function focus on mapping evoked responses of various components of motor, visual, somatosensory, memory and cognitive functions. Cerebral development, neuronal plasticity, and compensatory reorganization to lesions or surgery are active areas of investigation. Various types of assays have been used to identify specific biological alterations, map progression and determine therapeutic responses in a wide variety of neuropsychiatric disorders and drug abuse. RP PHELPS, ME (reprint author), UNIV CALIF LOS ANGELES,SCH MED,CRUMP INST,DOE,BIOMED & ENVIRONM SCI LAB,NUCL MED LAB,LOS ANGELES,CA 90024, USA. FU NIMH NIH HHS [R01-MH-37916]; NINDS NIH HHS [P01-NS-15654] NR 54 TC 56 Z9 57 U1 0 U2 3 PU PLENUM PUBL CORP PI NEW YORK PA 233 SPRING ST, NEW YORK, NY 10013 SN 0364-3190 J9 NEUROCHEM RES JI Neurochem. Res. PD SEP PY 1991 VL 16 IS 9 BP 929 EP 940 DI 10.1007/BF00965836 PG 12 WC Biochemistry & Molecular Biology; Neurosciences SC Biochemistry & Molecular Biology; Neurosciences & Neurology GA GJ140 UT WOS:A1991GJ14000002 PM 1784338 ER PT J AU TJOELKER, MG LUXMOORE, RJ AF TJOELKER, MG LUXMOORE, RJ TI SOIL-NITROGEN AND CHRONIC OZONE STRESS INFLUENCE PHYSIOLOGY, GROWTH AND NUTRIENT STATUS OF PINUS-TAEDA-L AND LIRIODENDRON-TULIPIFERA-L SEEDLINGS SO NEW PHYTOLOGIST LA English DT Article DE PINUS-TAEDA (LOBLOLLY PINE); LIRIODENDRON-TULIPIFERA (YELLOW-POPLAR); OZONE; NITROGEN; AIR POLLUTION ID USE EFFICIENCY; YELLOW-POPLAR; NET PHOTOSYNTHESIS; LOBLOLLY-PINE; HYBRID POPLAR; ACID-RAIN; MINERAL-NUTRITION; VARYING NITROGEN; AIR-POLLUTION; PLANT-TISSUE AB The effects of soil nitrogen availability and chronic ozone stress on carbon and nutrient economy were investigated in loblolly pine (Pinus taeda L.) and yellow-poplar (Liriodendron tulipifera L.). One-year-old seedlings were planted individually in pots in forest soil of low (58-mu-g g-1), medium (96-mu-g g-1) or high (172-mu-g g-1) initial concentrations of soluble nitrogen. The seedlings were exposed to ozone in open-top field chambers at sub-ambient (charcoal-filtered air), ambient, and elevated (ambient + 60 nl l-1 O3) (32, 56, 108 nl l-1 O3, 7 h seasonal mean, respectively) levels for 18 weeks. At final harvest loblolly pine dry matter increased by 50 % at the highest soil N level relative to the low with the largest gains in new needle biomass. Elevated ozone reduced the biomass of current-year needles by 20 % in plants grown at the highest N level. Higher soil N supply increased the concentration of nitrogen in needles, stimulated current-year needle photosynthesis and increased needle and whole-plant water-use efficiencies. Ozone treatment had no significant effect on photosynthesis or water-use efficiency in either species, although ozone exposure tended to reduce stomatal conductance in loblolly pine. The low N treatment increased the proportion of dry matter allocated to fine roots in yellow-poplar, but whole-plant dry weight had not responded to N fertilization at the final harvest, suggesting other limitations on growth. Ozone exposure increased leaf abscission and doubled leaf turnover in yellow-poplar. Although yellow-poplar was highly sensitive to ozone-induced leaf abscission, final whole-plant dry weights were not affected. The indeterminate growth habit of yellow-poplar permitted compensatory leaf growth which may have ameliorated effects of chronic ozone stress on biomass gain. Ozone exposure also decreased shoot weight more than root weight, resulting in higher root:shoot ratios in loblolly pine and a similar trend in higher fine root:leaf ratios in yellow-poplar. Greater proportional allocation of carbon to roots in response to nutrient deficiency may preclude an increased allocation to shoots often observed in response to air pollution stress. Interspecific differences in growth response to chronic ozone and nutrient stress may be influenced by differences in leaf growth habit. C1 OAK RIDGE NATL LAB,DIV ENVIRONM SCI,OAK RIDGE,TN 37831. RI Tjoelker, Mark/M-2413-2016 OI Tjoelker, Mark/0000-0003-4607-5238 NR 56 TC 58 Z9 59 U1 1 U2 11 PU CAMBRIDGE UNIV PRESS PI NEW YORK PA 40 WEST 20TH STREET, NEW YORK, NY 10011-4211 SN 0028-646X J9 NEW PHYTOL JI New Phytol. PD SEP PY 1991 VL 119 IS 1 BP 69 EP 81 DI 10.1111/j.1469-8137.1991.tb01009.x PG 13 WC Plant Sciences SC Plant Sciences GA GJ004 UT WOS:A1991GJ00400008 ER PT J AU NEITZEL, DA SCOTT, MJ SHANKLE, SA CHATTERS, JC AF NEITZEL, DA SCOTT, MJ SHANKLE, SA CHATTERS, JC TI THE EFFECT OF CLIMATE CHANGE ON STREAM ENVIRONMENTS - THE SALMONID RESOURCE OF THE COLUMBIA RIVER BASIN SO NORTHWEST ENVIRONMENTAL JOURNAL LA English DT Article AB The economically important salmon and steelhead fishery already is depressed, due to a number of environmental factors, including overfishing, hydroelectric dams, irrigation, agriculture, industry, and habitat destruction. Now it faces human-induced climate change over the next 50-100 years. The authors discuss past climate change as an analog for predicting this future change, as well as the use of computer models for prediction purposes. Considerable uncertainty surrounds predictions and the effects of climate changes on steelhead and salmon. RP NEITZEL, DA (reprint author), PACIFIC NW LAB, RICHLAND, WA 99352 USA. NR 0 TC 15 Z9 15 U1 3 U2 7 PU INST ENVIRON STUD PI SEATTLE PA UNIV WASHINGTON ENGINEERING ANNEX FM-12, SEATTLE, WA 98195 SN 0749-7962 J9 NORTHWEST ENVIRON J PD FAL-WIN PY 1991 VL 7 IS 2 BP 271 EP 293 PG 23 WC Ecology; Environmental Sciences; Forestry SC Environmental Sciences & Ecology; Forestry GA HU360 UT WOS:A1991HU36000006 ER PT J AU KAHL, L KROEBEL, R STORCH, W HOLTON, LK DIERKS, RD AF KAHL, L KROEBEL, R STORCH, W HOLTON, LK DIERKS, RD TI INVESTIGATION OF THE THERMAL-BEHAVIOR OF HIGH-LEVEL WASTE GLASS IN STEEL CANISTERS DURING COOLING AND AT EQUILIBRIUM SO NUCLEAR ENGINEERING AND DESIGN LA English DT Article; Proceedings Paper CT 1989 ANNUAL MEETING ON NUCLEAR TECHNOLOGY CY MAY 09-11, 1989 CL DUSSELDORF, GERMANY SP KERNTECH GESELL, DEUT ATOMFORUM AB Since the decision was taken to vitrify high-level-liquid waste from reprocessing operations worldwide, the further behaviour of produced glass blocks became interesting especially during cooling. Crack formation and its influence of surface increase, heat removal, equilibrium temperature distribution were investigated and inactive simulates and finally with two high-level glass canisters. In both cases the acoustic emission analysis was used simultaneously with temperature profile recording to evaluate different cooling modes on the above mentioned characteristics. As result one can state, that crack free active blocks cannot be produced due to remaining thermal gradients. However heat removal is not hampered by the cracks formed. The equilibrium temperature profiles can be calculated after fitting the computer codes with results of this report and surface increase estimates are evaluated according to different cooling procedures. C1 FRAUNHOFER INST SILICATFORSCH, WURZBURG, GERMANY. PACIFIC NW LAB, RICHLAND, WA 99352 USA. RP KAHL, L (reprint author), KERNFORSCHUNGSZENTRUM KARLSRUHE GMBH, W-7500 KARLSRUHE 1, GERMANY. NR 5 TC 2 Z9 2 U1 0 U2 1 PU ELSEVIER SCIENCE SA LAUSANNE PI LAUSANNE 1 PA PO BOX 564, 1001 LAUSANNE 1, SWITZERLAND SN 0029-5493 J9 NUCL ENG DES JI Nucl. Eng. Des. PD SEP PY 1991 VL 130 IS 1 BP 77 EP 88 DI 10.1016/0029-5493(91)90195-N PG 12 WC Nuclear Science & Technology SC Nuclear Science & Technology GA GK334 UT WOS:A1991GK33400012 ER PT J AU REDI, MH COHEN, SA SYNAKOWSKI, EJ AF REDI, MH COHEN, SA SYNAKOWSKI, EJ TI TRANSPORT SIMULATIONS OF HELIUM EXHAUST IN ITER USING RECENT DATA FROM TFTR, TEXTOR AND JT-60 SO NUCLEAR FUSION LA English DT Article ID PARTICLE-TRANSPORT; PLASMA; TOKAMAKS; BALDUR; MODES; CODE AB Insufficient helium exhaust can seriously degrade the performance of any fusion reactor and has recently been identified as a potentially significant issue for the International Thermonuclear Experimental Reactor (ITER). The effects of variations of the ratios D(He)/chi-i, D(He)/D(D) and V(He)/D(He) and of the sawtooth period on helium exhaust in ITER have been studied with BALDUR code transport simulations. Recent measurements of D(He)/chi-i in TFTR, of D(He)/D(D) in TEXTOR and of V(He)/D(He) in TFTR, TEXTOR and JT-60 are found to be compatible with the requirements of sustained ignition and helium exhaust for ITER. Ignition is found to be critically sensitive to the ratio V(He)/D(He), particularly at the plasma edge, and to a reduced sawtooth period. These critical dependences are moderated for reduced helium recycling at the separatrix and for hollow particle diffusivity profiles. RP REDI, MH (reprint author), PRINCETON UNIV,PLASMA PHYS LAB,PRINCETON,NJ 08544, USA. NR 29 TC 14 Z9 14 U1 0 U2 2 PU INT ATOMIC ENERGY AGENCY PI VIENNA PA WAGRAMERSTRASSE 5 PO BOX 100, A-1400 VIENNA, AUSTRIA SN 0029-5515 J9 NUCL FUSION JI Nucl. Fusion PD SEP PY 1991 VL 31 IS 9 BP 1689 EP 1694 DI 10.1088/0029-5515/31/9/007 PG 6 WC Physics, Fluids & Plasmas SC Physics GA GH663 UT WOS:A1991GH66300007 ER PT J AU CHARPAK, G GIOMATARIS, Y LEDERMAN, L AF CHARPAK, G GIOMATARIS, Y LEDERMAN, L TI A TRIGGER FOR BEAUTY SO NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH SECTION A-ACCELERATORS SPECTROMETERS DETECTORS AND ASSOCIATED EQUIPMENT LA English DT Article AB The possibility of B-meson experiments, in a fixed-target high-energy proton machine (Tevatron) is discussed. Compared to a B-meson factory experiment, it can produce 10(5) BB'sBAR per hour, using 10(8) protons per second, but it suffers from high background and needs high selectivity to cope with the million times higher interaction rate. To overcome these difficulties a technique called the "optical trigger for beauty" is proposed, based on the detection of Cherenkov photons produced in a 2 mm thick LiF crystal, through a fast photodetector. Its virtue is that it is opaque to minimum-bias events originating in a small target, but sensitive to the high impact parameter B-meson decay charged particles from a secondary vertex. Calculations and first simulations results give a good efficiency for B-meson detection. A multistep trigger, combining the "optical trigger" and a tracking detector, allows significant selection and a consequent enrichment of the data sample. Taking into account its fast response (approximately 1 ns), the above considerations can be extended to other hadronic machines, especially those with high-rate environments such as the LHC or SSC. C1 WORLD LAB,LAUSANNE,SWITZERLAND. FERMI NATL ACCELERATOR LAB,BATAVIA,IL 60510. UNIV CHICAGO,CHICAGO,IL 60637. RP CHARPAK, G (reprint author), CERN,CH-1211 GENEVA 23,SWITZERLAND. NR 14 TC 12 Z9 12 U1 1 U2 1 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0168-9002 J9 NUCL INSTRUM METH A JI Nucl. Instrum. Methods Phys. Res. Sect. A-Accel. Spectrom. Dect. Assoc. Equip. PD SEP 1 PY 1991 VL 306 IS 3 BP 439 EP 445 DI 10.1016/0168-9002(91)90037-Q PG 7 WC Instruments & Instrumentation; Nuclear Science & Technology; Physics, Nuclear; Physics, Particles & Fields SC Instruments & Instrumentation; Nuclear Science & Technology; Physics GA GD836 UT WOS:A1991GD83600004 ER PT J AU ATWOOD, WB BARCZEWSKI, T BAUERDICK, LAT BELLANTONI, L BLUCHER, E BLUM, W BOUDREAU, J BOYLE, O CINABRO, D CONWAY, J COWAN, G COWEN, DF EFTHYMIOPOULOS, I FAURE, P FENG, Z FIDECARO, F GOBBO, B HALLEY, AW HAYWOOD, S JAHN, A JARED, RC JOHNSON, RP KASEMANN, M KLEINKNECHT, K LECLAIRE, B LEHRAUS, I LOFSTEDT, B LOHSE, T LUEKE, D LUSIANI, A MARROCCHESI, PS MAY, J MEYER, TC MORSANI, F MINTEN, A PATER, J POLLMANN, D PRICE, M RICHTER, R RICHTER, W ROEHN, S ROLANDI, L ROTH, A ROTSCHEIDT, H SCHLATTER, D SCHMELLING, M SCHMIDT, H SCHROEDER, J SETTLES, R STEEG, F STEFANINI, G STIERLIN, U TAKASHIMA, M TEJESSY, W TENHAVE, I THOMAS, J VAYAKI, A WEAR, J WIEDENMANN, W WITZELING, W WU, SL AF ATWOOD, WB BARCZEWSKI, T BAUERDICK, LAT BELLANTONI, L BLUCHER, E BLUM, W BOUDREAU, J BOYLE, O CINABRO, D CONWAY, J COWAN, G COWEN, DF EFTHYMIOPOULOS, I FAURE, P FENG, Z FIDECARO, F GOBBO, B HALLEY, AW HAYWOOD, S JAHN, A JARED, RC JOHNSON, RP KASEMANN, M KLEINKNECHT, K LECLAIRE, B LEHRAUS, I LOFSTEDT, B LOHSE, T LUEKE, D LUSIANI, A MARROCCHESI, PS MAY, J MEYER, TC MORSANI, F MINTEN, A PATER, J POLLMANN, D PRICE, M RICHTER, R RICHTER, W ROEHN, S ROLANDI, L ROTH, A ROTSCHEIDT, H SCHLATTER, D SCHMELLING, M SCHMIDT, H SCHROEDER, J SETTLES, R STEEG, F STEFANINI, G STIERLIN, U TAKASHIMA, M TEJESSY, W TENHAVE, I THOMAS, J VAYAKI, A WEAR, J WIEDENMANN, W WITZELING, W WU, SL TI PERFORMANCE OF THE ALEPH TIME PROJECTION CHAMBER SO NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH SECTION A-ACCELERATORS SPECTROMETERS DETECTORS AND ASSOCIATED EQUIPMENT LA English DT Article ID WIRE; EXB AB The performance of the ALEPH Time Projection Chamber (TPC) has been studied using data taken during the LEP running periods in 1989 and 1990. After correction of residual distortions and optimisation of coordinate reconstruction algorithms, single coordinate resolutions of 173-mu-m in the azimuthal and 740-mu-m in the longitudinal direction are achieved. This results in a momentum resolution for the TPC of DELTA-p/p2 = 1.2 x 10(-3) (GeV/c)-1. In combination with the ALEPH Inner Tracking Chamber (ITC), a total momentum resolution of DELTA-p/p2 = 0.8 x 10(-3) (GeV/c)-1 is obtained. With respect to particle identification, the detector achieves a resolution of 4.4% for the measurement of the ionisation energy loss. C1 DEMOCRITOS NUCL RES CTR,ATHENS,GREECE. UNIV GLASGOW,GLASGOW G12 8QQ,SCOTLAND. UNIV MAINZ,INST PHYS,W-6500 MAINZ,GERMANY. MAX PLANCK INST PHYS & ASTROPHYS,W-8000 MUNICH 40,GERMANY. IST NAZL FIS NUCL,DIPARTMENTO FIS,PISA,ITALY. SCUOLA NORMALE SUPER PISA,I-56100 PISA,ITALY. IST FIS,TRIESTE,ITALY. IST NAZL FIS NUCL,TRIESTE,ITALY. UNIV WISCONSIN,MADISON,WI 53706. UNIV DORTMUND,INST PHYS,W-4600 DORTMUND 50,GERMANY. UNIV CALIF BERKELEY LAWRENCE BERKELEY LAB,BERKELEY,CA 94720. STANFORD LINEAR ACCELORATOR LAB,STANFORD,CA 94309. RP ATWOOD, WB (reprint author), CERN,CH-1211 GENEVA 23,SWITZERLAND. RI Rolandi, Luigi (Gigi)/E-8563-2013; Lusiani, Alberto/N-2976-2015; Marrocchesi, Pier Simone/N-9068-2015; Lusiani, Alberto/A-3329-2016 OI Rolandi, Luigi (Gigi)/0000-0002-0635-274X; Lusiani, Alberto/0000-0002-6876-3288; Marrocchesi, Pier Simone/0000-0003-1966-140X; Lusiani, Alberto/0000-0002-6876-3288 NR 21 TC 46 Z9 46 U1 1 U2 3 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0168-9002 J9 NUCL INSTRUM METH A JI Nucl. Instrum. Methods Phys. Res. Sect. A-Accel. Spectrom. Dect. Assoc. Equip. PD SEP 1 PY 1991 VL 306 IS 3 BP 446 EP 458 DI 10.1016/0168-9002(91)90038-R PG 13 WC Instruments & Instrumentation; Nuclear Science & Technology; Physics, Nuclear; Physics, Particles & Fields SC Instruments & Instrumentation; Nuclear Science & Technology; Physics GA GD836 UT WOS:A1991GD83600005 ER PT J AU ALSMILLER, RG ALSMILLER, FS AF ALSMILLER, RG ALSMILLER, FS TI LOW-ENERGY PARTICLE-PRODUCTION AND TRANSPORT FOR 200 GEV/C PROTONS IN IRON AND COMPARISONS WITH EXPERIMENTAL-DATA SO NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH SECTION A-ACCELERATORS SPECTROMETERS DETECTORS AND ASSOCIATED EQUIPMENT LA English DT Article AB Calculated results for 200 GeV/c protons incident on an iron, calorimeter-like, target are presented and compared with experimental data. The calculations were carried out with the hadron transport code HETC88. The quantities that are compared are the production per unit volume of F-18 and Na-24 in aluminum and the production per unit volume of In-115m in indium as a function of depth and radius in the target. The production of Na-24 and In-115m is due primarily to the low energy (less-than-or-similar-to 20 MeV) neutron flux, and thus the comparisons here test the capability of HETC88 for producing and transporting these low-energy neutrons or more precisely for predicting the flux per unit energy of these low-energy neutrons as a function of depth and radius in the target. The calculated results are in good agreement with the F-118 production data (energies greater-than-or-similar-to 40 MeV) and the Na-24 production data (energies greater-than-or-similar-to 5 MeV) and in moderate agreement with the In-115m production data (energies greater-than-or-similar-to 0.4 MeV.) RP ALSMILLER, RG (reprint author), OAK RIDGE NATL LAB,DIV ENGN PHYS & MATH,BLDG 6025,MS-6364,POB 2008,OAK RIDGE,TN 37831, USA. NR 8 TC 2 Z9 2 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 SEP 1 PY 1991 VL 306 IS 3 BP 500 EP 503 DI 10.1016/0168-9002(91)90043-P PG 4 WC Instruments & Instrumentation; Nuclear Science & Technology; Physics, Nuclear; Physics, Particles & Fields SC Instruments & Instrumentation; Nuclear Science & Technology; Physics GA GD836 UT WOS:A1991GD83600010 ER PT J AU SESSLER, AM WHITTUM, DH WURTELE, JS SHARP, WM MAKOWSKI, MA AF SESSLER, AM WHITTUM, DH WURTELE, JS SHARP, WM MAKOWSKI, MA TI STANDING-WAVE FREE-ELECTRON LASER 2-BEAM ACCELERATOR SO NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH SECTION A-ACCELERATORS SPECTROMETERS DETECTORS AND ASSOCIATED EQUIPMENT LA English DT Article ID RELATIVISTIC KLYSTRON; LINEAR ACCELERATORS; INSTABILITIES AB A free-electron laser (FEL) two-beam accelerator (TBA) is proposed, in which the FEL interaction takes place in a series of drive cavities, rather than in a waveguide. Each drive cavity is "beat-coupled" to a section of the accelerating structure. This standing-wave TBA is investigated theoretically and numerically, with analyses included of microwave extraction, growth of the FEL signal through saturation, equilibrium longitudinal beam dynamics following saturation, and sensitivity of the microwave amplitude and phase to errors in current and energy. It is found that phase errors due to current jitter are substantially reduced from previous versions of the TBA. Analytic scalings and numerical simulations are used to obtain an illustrative TBA parameter set. C1 MIT,DEPT PHYS,CAMBRIDGE,MA 02139. UNIV CALIF LAWRENCE LIVERMORE NATL LAB,LIVERMORE,CA 94550. RP SESSLER, AM (reprint author), UNIV CALIF BERKELEY LAWRENCE BERKELEY LAB,BERKELEY,CA 94720, USA. RI wurtele, Jonathan/J-6278-2016 OI wurtele, Jonathan/0000-0001-8401-0297 NR 29 TC 16 Z9 16 U1 1 U2 2 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0168-9002 J9 NUCL INSTRUM METH A JI Nucl. Instrum. Methods Phys. Res. Sect. A-Accel. Spectrom. Dect. Assoc. Equip. PD SEP 1 PY 1991 VL 306 IS 3 BP 592 EP 605 DI 10.1016/0168-9002(91)90057-W PG 14 WC Instruments & Instrumentation; Nuclear Science & Technology; Physics, Nuclear; Physics, Particles & Fields SC Instruments & Instrumentation; Nuclear Science & Technology; Physics GA GD836 UT WOS:A1991GD83600024 ER PT J AU MUSKET, RG AF MUSKET, RG TI EXTRACTING THE NET O(K) X-RAY PEAK FROM SI(LI)-DETECTOR SPECTRA SO NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH SECTION B-BEAM INTERACTIONS WITH MATERIALS AND ATOMS LA English DT Article AB The shape of the O(K) X-ray peak has been extracted from spectra taken using a cryogenically cooled Si(Li) detector with an ice layer on the crystal. The spectrum stripping method consists of subtracting a PIXE spectrum of beryllium taken with the BeO surface layer removed from that taken with the BeO surface layer intact. The method relies on the fact that the background spectrum is not affected by the removal of the thin layer containing surface oxygen. The resulting O(K) peak shape corresponds to that measurable with a de-iced detector and can be used to determine the shape of the bremsstrahlung background in the vicinity of the O(K) edge. With proper normalizations, the net O(K) integral can be determined using these two shapes. These results help explain the apparently varied O(K) X-ray peak shapes previously reported in the literature. RP MUSKET, RG (reprint author), UNIV CALIF LAWRENCE LIVERMORE NATL LAB,LIVERMORE,CA 94550, USA. NR 5 TC 0 Z9 0 U1 0 U2 0 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 SEP PY 1991 VL 61 IS 3 BP 322 EP 324 DI 10.1016/0168-583X(91)95637-S PG 3 WC Instruments & Instrumentation; Nuclear Science & Technology; Physics, Atomic, Molecular & Chemical; Physics, Nuclear SC Instruments & Instrumentation; Nuclear Science & Technology; Physics GA GG333 UT WOS:A1991GG33300008 ER PT J AU ALLEN, WR AF ALLEN, WR TI LATTICE LOCATION OF ION-IMPLANTED HE-3 IN SAPPHIRE SO NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH SECTION B-BEAM INTERACTIONS WITH MATERIALS AND ATOMS LA English DT Article ID CHANNELING RADIATION; MEV ELECTRONS; ALPHA-AL2O3; DEPENDENCE; CRYSTALS; PROTONS; METALS; PB AB The lattice location of He-3 implanted near room temperature at 200 keV in sapphire has been specified by techniques of ion channeling and nuclear reaction analysis. Channeling angular scans indicated that a typical helium atom preferentially resides in a position slightly displaced from an octahedral interstitial site, referenced relative to the oxygen sublattice, that was intrinsically unfilled by an aluminum cation. With an apparent substitutional fraction of 0.70 +/- 0.10 inferred from <0001> axial channeling, occupation of an intrinsically unfilled octahedral interstice by a single helium atom dominated over other potential trapping locations such as irradiation-produced vacancies. A channeling angular scan for the (1102BAR) plane was instrumental for verification of the lattice site. The tendency for helium to accumulate in vacancy clusters or bubbles was found to be minimal. RP ALLEN, WR (reprint author), OAK RIDGE NATL LAB,DIV MET & CERAM,POB 2008,OAK RIDGE,TN 37831, USA. NR 39 TC 6 Z9 6 U1 0 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 SEP PY 1991 VL 61 IS 3 BP 325 EP 336 DI 10.1016/0168-583X(91)95638-T PG 12 WC Instruments & Instrumentation; Nuclear Science & Technology; Physics, Atomic, Molecular & Chemical; Physics, Nuclear SC Instruments & Instrumentation; Nuclear Science & Technology; Physics GA GG333 UT WOS:A1991GG33300009 ER PT J AU LEAL, LC DESAUSSURE, G PEREZ, RB AF LEAL, LC DESAUSSURE, G PEREZ, RB TI AN R-MATRIX ANALYSIS OF THE U-235 NEUTRON-INDUCED CROSS-SECTIONS UP TO 500 EV SO NUCLEAR SCIENCE AND ENGINEERING LA English DT Article ID FISSION; RESONANCE; PU-239 AB A detailed evaluation of the R matrix resonance parameters describing the interaction of neutrons with U-235 has been performed up to 500 eV using the most recent high-resolution measurements of the U-235 neutron cross sections. The availability of U-235 spin-separated neutron cross-section data, in conjunction with the use of the DELTA-3 statistics of Metha and Dyson, has made possible a detailed study of the statistical distribution of the resonance parameters and their average values. The present R matrix resonance parameters have been converted into equivalent sets of Adler-Adler parameters and multipole momentum space expansion parameters. Extensive validation of this evaluation has been performed by comparing self-shielded fission rates computed with these R matrix parameters with the measurements of Czirr; a test of the ENDF/B unresolved resonance formalism for the calculation of U-235 self-shielding factors is also presented. C1 OAK RIDGE NATL LAB,OAK RIDGE,TN 37831. RP LEAL, LC (reprint author), ARGONNE NATL LAB,9700 S CASS AVE,ARGONNE,IL 60439, USA. NR 37 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 SEP PY 1991 VL 109 IS 1 BP 1 EP 17 PG 17 WC Nuclear Science & Technology SC Nuclear Science & Technology GA GC930 UT WOS:A1991GC93000001 ER PT J AU FU, CY AF FU, CY TI PAIRING CORRECTIONS AND SPIN CUTOFF FACTORS IN EXCITON LEVEL DENSITIES FOR 2 KINDS OF FERMIONS SO NUCLEAR SCIENCE AND ENGINEERING LA English DT Article ID NUCLEAR-REACTION THEORY; HOLE STATE DENSITIES; IMPLEMENTATION; MODEL AB Pairing corrections in particle-hole (exciton) state-density formulas used in precompound nuclear reaction theories are, strictly speaking, dependent on the nuclear excitation energy U and the exciton number n. A general formula for (U, n)-dependent pairing corrections was derived earlier for the exciton state-density formula for a system of one kind of fermion. A similar derivation is made for a system of two kinds of fermions, a system in which neutrons and protons occupy different sets of single-particle states. It is shown that the constant-pairing-energy correction used in standard state-density formulas, such as U0 in Gilbert and Cameron, is a limiting case of the present general (U, n)-dependent results. Spin cutoff factors are calculated using the same pairing theory and parameterized into an explicit (U, n)-dependent function, thereby defining the exciton level-density formula for two kinds of fermions. The results show that the ratios in the exciton level densities in the one- and two-fermion approaches vary with both U and n, thus, most likely leading to differences in calculated compound-to-precompound ratios. However, the differences in the spin cutoff factors in the two cases are found to be rather small. RP FU, CY (reprint author), OAK RIDGE NATL LAB,OAK RIDGE,TN 37831, USA. NR 11 TC 4 Z9 4 U1 0 U2 0 PU AMER NUCLEAR SOCIETY PI LA GRANGE PK PA 555 N KENSINGTON AVENUE, LA GRANGE PK, IL 60525 SN 0029-5639 J9 NUCL SCI ENG JI Nucl. Sci. Eng. PD SEP PY 1991 VL 109 IS 1 BP 18 EP 25 PG 8 WC Nuclear Science & Technology SC Nuclear Science & Technology GA GC930 UT WOS:A1991GC93000002 ER PT J AU STAMPS, DW BERMAN, M AF STAMPS, DW BERMAN, M TI HIGH-TEMPERATURE HYDROGEN COMBUSTION IN REACTOR SAFETY APPLICATIONS SO NUCLEAR SCIENCE AND ENGINEERING LA English DT Article ID FLAMMABILITY LIMITS; MIXTURES; AIR; STABILITY AB The effect of elevated temperature on the limits of the various modes of combustion of hydrogen-air-steam mixtures is reviewed. The modes include spontaneous combustion, diffusion flames, deflagrations, and detonations. The existing data on high-temperature hydrogen combustion are reviewed, areas where uncertainties exist are identified, and the importance of these uncertainties are discussed with respect to reactor safety for four different accident scenarios. RP STAMPS, DW (reprint author), SANDIA NATL LABS,POB 5800,ALBUQUERQUE,NM 87185, USA. NR 41 TC 9 Z9 9 U1 0 U2 0 PU AMER NUCLEAR SOCIETY PI LA GRANGE PK PA 555 N KENSINGTON AVENUE, LA GRANGE PK, IL 60525 SN 0029-5639 J9 NUCL SCI ENG JI Nucl. Sci. Eng. PD SEP PY 1991 VL 109 IS 1 BP 39 EP 48 PG 10 WC Nuclear Science & Technology SC Nuclear Science & Technology GA GC930 UT WOS:A1991GC93000004 ER PT J AU HENDRICKS, JS AF HENDRICKS, JS TI EFFECTS OF CHANGING THE RANDOM NUMBER STRIDE IN MONTE-CARLO CALCULATIONS SO NUCLEAR SCIENCE AND ENGINEERING LA English DT Note AB A common practice in Monte Carlo radiation transport codes is to start each random walk a specified number of steps up the random number sequence from the previous one. This is called the stride in the random number sequence between source particles. It is used for correlated sampling or to provide tree-structured random numbers. A new random number generator algorithm for the major Monte Carlo code MCNP has been written to allow adjustment of the random number stride. This random number generator is machine portable. The effects of varying the stride for several sample problems are examined. RP HENDRICKS, JS (reprint author), UNIV CALIF LOS ALAMOS SCI LAB,POB 1663,X-6,MS B226,LOS ALAMOS,NM 87545, USA. NR 5 TC 3 Z9 3 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 SEP PY 1991 VL 109 IS 1 BP 86 EP 91 PG 6 WC Nuclear Science & Technology SC Nuclear Science & Technology GA GC930 UT WOS:A1991GC93000007 ER PT J AU DICKENS, JK AF DICKENS, JK TI ANALYSIS OF BETA-RAY DATA IMPORTANT TO DECAY HEAT PREDICTIONS SO NUCLEAR SCIENCE AND ENGINEERING LA English DT Note ID FISSION-PRODUCTS; GROSS THEORY; SPECTRA AB Recently obtained experimental total beta-ray spectra for 77 radionuclides created during fission of U-235 are compared with predicted total beta-ray spectra based on beta-ray transition energies and intensities of individual components currently available in the Evaluated Nuclear Structure Data File (ENSDF). In addition, experimental average beta-ray energies for 100 radionuclides are compared with evaluated/theoretical from four compilations, namely, (a) a 1982 compilation, (b) the 1989 and current ENSDF, (c) a 1988 compilation by the Japanese Nuclear Data Committee, and (d) predictions using the microscopic theory of Klapdor and Metzinger. None of these evaluations/predictions is superior in reproducing the experimental data. A comparison of the experimental with the total available beta decay energies Q-beta indicates that the approximation almost-equal-to Q-beta/3 somewhat overestimates on the average; however, the ratio R = /Q-beta varies between 0.11 and 0.46, and there is no discernible trend in R compared with Q-beta or nor a discernible difference for radionuclides having T1/2 less-than-or-equal-to 2 s compared with those having T1/2 > 2 s. Lastly, the intensities of possible ground-state decay transitions were estimated for 47 radionuclides and compared with similar data in ENSDF. In 14 cases, a nonzero ENSDF value is supported by the experimental data, and in 8 cases a zero value in ENSDF is supported by the lack of experimental data suggesting a high-energy ground-state beta-ray transition. Of the remaining 25 radionuclides, the experimental data for 9 cases suggest that increases are needed in the ENSDF, and for 16 radionuclides the data indicate the need for smaller values of the ground-state transition intensities from those given in the ENSDF, being zero for 4 nuclides (Ga-80, Ga-81, 84As, and 145Cs). RP DICKENS, JK (reprint author), OAK RIDGE NATL LAB,POB 2008,OAK RIDGE,TN 37831, USA. NR 31 TC 1 Z9 1 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 SEP PY 1991 VL 109 IS 1 BP 92 EP 102 PG 11 WC Nuclear Science & Technology SC Nuclear Science & Technology GA GC930 UT WOS:A1991GC93000008 ER PT J AU TZANOS, CP PEDERSEN, DR AF TZANOS, CP PEDERSEN, DR TI ANALYSIS OF DRACS AND DRACS-RVACS DECAY HEAT REMOVAL EXPERIMENTS SO NUCLEAR TECHNOLOGY LA English DT Article DE DECAY HEAT REMOVAL; NATURAL CONVECTION; LIQUID-METAL REACTORS AB Two large-scale decay heat removal experiments are analyzed to support the validation of the thermal-hydraulic code COMMIX and the design of advanced liquid metal reactors (ALMRs). The experiments were performed in the reactor vessel auxiliary cooling system (RVACS) test facility, which provides a scaled simulation of the passive decay heat removal paths of a pool ALMR with the core simulated by electrically heated rods. The first experiment simulates a transient where decay heat is removed by the direct reactor auxiliary cooling system (DRACS) only. In the second experiment, heat is removed by both the DRACS and RVACS. These experiments are characterized by (a) three-dimensional in-pool sodium flows of very low velocity, driven by sodium density differences, (b) a significant pool thermal stratification, and (c) a complex heat sink. In the DRACS test, the thermal stratification occurs in the hot pool while the cold pool is nearly isothermal. When both systems are in operation the thermal stratification of the hot pool is drastically reduced while the upper third of the cold pool is significantly stratified. The COMMIX predictions for the sodium pool temperatures and the air outlet temperature of the RVACS are in good agreement with measurements. RP TZANOS, CP (reprint author), ARGONNE NATL LAB,DIV REACTOR ENGN,ARGONNE,IL 60439, USA. NR 13 TC 2 Z9 2 U1 0 U2 0 PU AMER NUCLEAR SOCIETY PI LA GRANGE PK PA 555 N KENSINGTON AVENUE, LA GRANGE PK, IL 60525 SN 0029-5450 J9 NUCL TECHNOL JI Nucl. Technol. PD SEP PY 1991 VL 95 IS 3 BP 253 EP 265 PG 13 WC Nuclear Science & Technology SC Nuclear Science & Technology GA GB998 UT WOS:A1991GB99800001 ER PT J AU REDMOND, EL RYSKAMP, JM AF REDMOND, EL RYSKAMP, JM TI MONTE-CARLO METHODS, MODELS, AND APPLICATIONS TO THE ADVANCED NEUTRON SOURCE SO NUCLEAR TECHNOLOGY LA English DT Article ID REACTOR DESIGN AB Three-dimensional continuous-energy coupled neutron-gamma Monte Carlo models of the Advanced Neutron Source (ANS) final preconceptual and conceptual reference core designs have been developed using the Monte Carlo Neutron and Photon transport code (MCNP) Version 3b. These models contain the reactor core with control rods, the heavy water reflector tank with shutdown rods and some beam tubes, and the outer light water pool. Eighty homogenized fuel zones per fuel element are used to represent the radial and axial U-235 fuel distribution. These models are the most sophisticated, physically accurate reactor physics models of the ANS currently available. The use of MCNP methods and applications to the ANS are demonstrated. Beam tube studies, coolant voiding studies, and many criticality studies have already been performed, as have studies with variance reduction techniques. In comparison with deterministic methods, MCNP proves superior in calculating the core multiplication factor and neutron fluxes in the reflector. The MCNP code offeres the ANS project the capability of performing complicated reactor physics calculations not currently possible with most deterministic methods. RP REDMOND, EL (reprint author), EG&G IDAHO INC,IDAHO NATL ENGN,POB 1625,IDAHO FALLS,ID 83415, USA. NR 16 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 0029-5450 J9 NUCL TECHNOL JI Nucl. Technol. PD SEP PY 1991 VL 95 IS 3 BP 272 EP 286 PG 15 WC Nuclear Science & Technology SC Nuclear Science & Technology GA GB998 UT WOS:A1991GB99800003 ER PT J AU HOBBINS, RR PETTI, DA OSETEK, DJ HAGRMAN, DL AF HOBBINS, RR PETTI, DA OSETEK, DJ HAGRMAN, DL TI REVIEW OF EXPERIMENTAL RESULTS ON LIGHT WATER-REACTOR CORE MELT PROGRESSION SO NUCLEAR TECHNOLOGY LA English DT Article ID BEHAVIOR; ACCIDENTS; RELEASE AB Results from integral-effects core melt progression experiments and from the examination of the damaged core of the Three Mile Island Unit 2 (TMI-2) reactor are reviewed to gain insight on key severe accident phenomena. The experiments and the TMI-2 accident represent a wide variety of conditions and physical scales, yet several important phenomena appear to be common to core melt progression. Eutectic interactions between core materials cause the formation of liquids and loss of original core geometry at low temperatures (approximately 1500 K) in a severe accident. The first liquids to form are metallic in nature, and they relocate to lower elevations in the core, where they may freeze into a crust that forms a partial flow blockage. At temperatures above approximately 2200 K, fuel liquefaction causes fuel-bearing debris to accumulate in the core above the metallic lower crust. The liquefied material oxidizes in steam as it relocates, and the accumulated melt can incorporate unmelted fuel rod debris. The result is the formation of a molten ceramic pool above the metallic crust. This molten pool can be uncoolable, as was the case in the TMI-2 accident, but failure of the peripheral crust can cause a coherent relocation of core melt to the lower plenum of the reactor and fragmentation of the melt in water to form a coolable debris (as occurred in the TMI-2 accident). Fission product release early in a severe accident is controlled by diffusion through solid fuel and is strongly influenced by microstructural features such as cracks and grain-boundary porosity interlinkage. Cracking due to rapid cooling (e.g., during reflooding) can enhance fission product release, as can liquefaction. Fission product release from the molten pool is controlled by bubble dynamics and the oxygen potential within the pool. Some inventory of volatile fission products, among others, remains in the melt, even after relocation to the lower plenum. C1 IDAHO FALLS CTR HIGHER EDUC,IDAHO FALLS,ID 83415. RP HOBBINS, RR (reprint author), EG&G IDAHO INC,IDAHO NATL ENGN LAB,POB 1625,IDAHO FALLS,ID 83415, USA. NR 66 TC 25 Z9 25 U1 0 U2 6 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 SEP PY 1991 VL 95 IS 3 BP 287 EP 307 PG 21 WC Nuclear Science & Technology SC Nuclear Science & Technology GA GB998 UT WOS:A1991GB99800004 ER PT J AU CHANG, SL LOTTES, SA BERRY, GF AF CHANG, SL LOTTES, SA BERRY, GF TI COMPUTATION OF 2-DIMENSIONAL, NONREACTING JET MAIN FLOW MIXING IN A MAGNETOHYDRODYNAMIC 2ND-STAGE COMBUSTOR SO NUMERICAL HEAT TRANSFER PART A-APPLICATIONS LA English DT Article AB A numerical solution describing a two-dimensional turbulent flow field with multiple gas species was used to study the interaction and mixing of opposed slot jets with the main flow in a rectangular channel. This study is part of a program to use computer modeling to aid in the design of a magnetohydrodynamic second-stage combustor. The effects of varying the jet angle and main inlet flow symmetry on the mixing patterns and rate of mixing were evaluated using computed velocity and species concentration fields. Mixing depends strongly on jet angle, and jet angles greater than 90-degrees produce better mixing. RP CHANG, SL (reprint author), ARGONNE NATL LAB,DIV ENERGY SYST,9700 S CASS AVE,ARGONNE,IL 60439, USA. NR 11 TC 2 Z9 2 U1 0 U2 0 PU HEMISPHERE PUBL CORP PI BRISTOL PA 1900 FROST ROAD, SUITE 101, BRISTOL, PA 19007-1598 SN 1040-7782 J9 NUMER HEAT TR A-APPL JI Numer. Heat Tranf. A-Appl. PD SEP PY 1991 VL 20 IS 2 BP 223 EP 236 DI 10.1080/10407789108944818 PG 14 WC Thermodynamics; Mechanics SC Thermodynamics; Mechanics GA GG792 UT WOS:A1991GG79200005 ER PT J AU CHEN, PJ AF CHEN, PJ TI MATHEMATICAL PRINCIPLES OF A NEW INTERFEROMETRIC SYSTEM SO NUOVO CIMENTO DELLA SOCIETA ITALIANA DI FISICA B-GENERAL PHYSICS RELATIVITY ASTRONOMY AND MATHEMATICAL PHYSICS AND METHODS LA English DT Article ID VELOCITY AB We introduce in this paper the mathematical principles of a new interferometric system. The analyses are couched within the framework of electromagnetic theory, neglecting relativistic effects. The basic physical set-up of the system is similar to that of the velocity interferometer but with the introduction of additional optical components, and has the advantage of eliminating the problem of the presence and/or the rotations of the principle axes of the dielectric tensor of the shocked portion of the window material. An added advantage of the system is that it is now possible to calculate the desired physical quantities from the experimental data of the fringe counts without having to calibrate window materials. RP CHEN, PJ (reprint author), SANDIA NATL LABS,ALBUQUERQUE,NM 87185, USA. NR 11 TC 0 Z9 0 U1 0 U2 0 PU EDITRICE COMPOSITORI BOLOGNA PI BOLOGNA PA VIA STALINGRADO 97/2, I-40128 BOLOGNA, ITALY SN 0369-3554 J9 NUOVO CIMENTO B JI Nouvo Cimento Soc. Ital. Fis. B-Gen. Phys. Relativ. Astron. Math. Phys. Methods PD SEP PY 1991 VL 106 IS 9 BP 983 EP 1001 DI 10.1007/BF02728342 PG 19 WC Physics, Multidisciplinary SC Physics GA GK952 UT WOS:A1991GK95200005 ER PT J AU ANDERSON, OP BENDER, BR NORTON, JR LARSON, AC VERGAMINI, PJ AF ANDERSON, OP BENDER, BR NORTON, JR LARSON, AC VERGAMINI, PJ TI SINGLE-CRYSTAL NEUTRON-DIFFRACTION STUDY OF (MU-ETA-1,ETA-1-C2H4)OS2(CO)8, A MODEL FOR ONE TYPE OF CHEMISORBED ETHYLENE SO ORGANOMETALLICS LA English DT Article ID GAS ELECTRON-DIFFRACTION; X-RAY; MOLECULAR-STRUCTURE; LOW-TEMPERATURE; BOND LENGTHS; REACTIVITY; COMPLEXES; OS3(CO)12; OSMIUM; 1,2-DIOSMACYCLOBUTANE AB The molecular structure of (mu-eta-1, eta-1-C2H4)Os2(CO)8 (1) has been determined by single-crystal neutron diffraction in order to establish the hybridization at the carbon atoms of the bridging ethylene. The final values for the lattice constants are a = 7.308 (2) angstrom, b = 13.448 (3) angstrom, c = 13.482 (4) angstrom, beta = 101.25 (2)-degrees, and V = 1299.5 (3) angstrom 3; the space group (P2(1)/c) and value of Z (4) are known from an earlier X-ray study. 1 The results show that the ethylene carbons have almost completely rehybridized to sp 3. The C-C bond length in 1 (1.5225 (26) angstrom) is comparable to that in ethane and that of ethylene chemisorbed on Pt(111)-suggesting that the ethylene ligand in 1 is a good structural model for ethylene chemisorbed on Pt(111). The Os2C2 ring of 1 is distorted further away from planarity than the Os4 ring of Os4(CO)16 or the C4 ring of cyclobutane. C1 COLORADO STATE UNIV,DEPT CHEM,FT COLLINS,CO 80523. LOS ALAMOS NATL LAB,LOS ALAMOS,NM 87545. NR 54 TC 28 Z9 28 U1 0 U2 0 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 SN 0276-7333 J9 ORGANOMETALLICS JI Organometallics PD SEP PY 1991 VL 10 IS 9 BP 3145 EP 3150 DI 10.1021/om00055a031 PG 6 WC Chemistry, Inorganic & Nuclear; Chemistry, Organic SC Chemistry GA GF405 UT WOS:A1991GF40500031 ER PT J AU CURTIS, CJ HALTIWANGER, RC AF CURTIS, CJ HALTIWANGER, RC TI PREPARATION OF DINUCLEAR ZIRCONIUM HYDRIDE COMPLEXES CONTAINING THE FULVALENE LIGAND AND THEIR REACTIONS WITH CARBON-MONOXIDE SO ORGANOMETALLICS LA English DT Article ID ALDEHYDE-ZIRCONOCENE COMPLEXES; OXOPHILIC TRANSITION-METALS; DYOTROPIC REARRANGEMENTS; MOLECULAR-STRUCTURES; TETRAVALENT ZIRCONIUM; DERIVATIVES; CHEMISTRY; TITANOCENE; REDUCTION; CRYSTAL AB The isolation of the lithium salt of the fulvalene dianion Li2(C10H8) is reported. Metathesis of this dianion with 2 equiv of (Cp*ZrCl3)x (Cp* = eta-5-C5Me5) yields the dinuclear zirconium complex (C10H8)[Cp*ZrCl2]2 (1). Treatment of 1 with 4 equiv of CH3Li yields the tetramethyl complex (C10H8)[Cp*Zr(CH3)2]2 (2). The reaction of 2 with H-2 produces the tetrahydride complex (C10H8)[Cp*ZrH2]2 (3). Complex 3 reacts selectively with CHCl3 to yield the hydrido chloride complex (C10H8)[Cp*Zr(H)Cl]2 (4). Complexes 3 and 4 react with CO under mild conditions to yield products containing bridging formaldehyde ligands, (C10H8)[Cp*Zr(OCH2)]2 (7) and (C10H8)[Cp*ZrCl]2(OCH2) (6), respectively. Complexes 3 and 6 are fluxional on the nuclear magnetic resonance (NMR) time scale and the dynamic processes were studied by variable-temperature H-1 NMR. The structure of 7 was determined by X-ray diffraction. Complex 7 crystallizes in a monoclinic unit cell with P2(1) symmetry with a = 8.273 (2) angstrom, b = 15.383 (4) angstrom, c = 11.250 (3) angstrom, beta = 101.26 (2)-degrees, V = 1404.1 (7) angstrom 3, Z = 2, and d(calcd) = 1.516 g/cm3. Full-matrix least-squares refinement converged with final residuals R = 5.10% and R(w) = 5.80%. C1 UNIV COLORADO,DEPT CHEM,BOULDER,CO 80309. RP CURTIS, CJ (reprint author), SOLAR ENERGY RES INST,PHOTOCONVERS RES BRANCH,1617 COLE BLVD,GOLDEN,CO 80401, USA. NR 62 TC 28 Z9 28 U1 0 U2 2 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 SN 0276-7333 J9 ORGANOMETALLICS JI Organometallics PD SEP PY 1991 VL 10 IS 9 BP 3220 EP 3226 DI 10.1021/om00055a045 PG 7 WC Chemistry, Inorganic & Nuclear; Chemistry, Organic SC Chemistry GA GF405 UT WOS:A1991GF40500045 ER PT J AU LIN, S STRUVE, WS AF LIN, S STRUVE, WS TI TIME-RESOLVED FLUORESCENCE OF NITROBENZOXADIAZOLE AMINOHEXANOIC ACID - EFFECT OF INTERMOLECULAR HYDROGEN-BONDING ON NONRADIATIVE DECAY SO PHOTOCHEMISTRY AND PHOTOBIOLOGY LA English DT Article ID EXCITATION TRANSPORT AB The fluorescence kinetics of the nitrobenzoxadiazole (NBD) chromophore were studied at low concentrations in solvents with varying polarity and hydrogen-bonding donor strength. The emission decay was essentially single exponential in all solvents studied. While the absorption and fluorescence solvatochromism is determined largely by the solvent polarity, the S1 state decay kinetics are strongly modulated by the solvent H-bonding capacity. The NBD emission lifetime, generally approximately 7-10 ns in the aprotic solvents, is reduced to 0.933 ns in water. The solvent deuterium isotope effect on the fluorescence decay is substantial in D2O and in methanol-d4, but is insignificant in DMSO-d6. These results are consistent with acceleration of S1 --> S0 internal conversion through an accepting vibrational mode created by intermolecular hydrogen-bonding of the NBD chromophore to an H atom-donating solvent. This work bears on the practicality of using NBD as a fluorophore in assays for estrogen and progesterone receptors. C1 IOWA STATE UNIV SCI & TECHNOL,DEPT CHEM,AMES,IA 50011. IOWA STATE UNIV SCI & TECHNOL,US DOE,AMES LAB,AMES,IA 50011. NR 9 TC 90 Z9 90 U1 3 U2 20 PU AMER SOC PHOTOBIOLOGY PI AUGUSTA PA BIOTECH PARK, 1021 15TH ST, SUITE 9, AUGUSTA, GA 30901-3158 SN 0031-8655 J9 PHOTOCHEM PHOTOBIOL JI Photochem. Photobiol. PD SEP PY 1991 VL 54 IS 3 BP 361 EP 365 DI 10.1111/j.1751-1097.1991.tb02028.x PG 5 WC Biochemistry & Molecular Biology; Biophysics SC Biochemistry & Molecular Biology; Biophysics GA GA539 UT WOS:A1991GA53900005 PM 1784635 ER PT J AU GRAY, KE KIM, DH AF GRAY, KE KIM, DH TI FLUX PINNING AND DISSIPATION IN HIGH-TEMPERATURE SUPERCONDUCTORS SO PHYSICA C LA English DT Article; Proceedings Paper CT INTERNATIONAL WORKSHOP ON HIGH TEMPERATURE SUPERCONDUCTING THIN FILMS : PROPERTIES AND APPLICATION ( HTSCTF ) CY APR 15-19, 1991 CL ROME, ITALY SP CNR, GRP NAZL STRUTTURA MAT, CONSORZIO INTERUNIV NAZL FIS MAT, IST NAZL FIS NUCL, UNIV ROME TOR VERGATA ID BA-CU-O; VORTEX-GLASS SUPERCONDUCTIVITY; LORENTZ-FORCE INDEPENDENCE; HIGH-TC OXIDES; CRITICAL CURRENTS; MAGNETIC-FIELDS; RESISTIVE TRANSITION; JOSEPHSON-JUNCTIONS; RESISTANCE TAILS; SINGLE-CRYSTAL AB The effect of anisotropy on the field-induced broadening of resistive transitions in the highly-anisotropic high-temperature superconductors (HTS) is considered. For the applied field, H, parallel to the superconducting Cu-O layers the absence of a Lorentz-force, together with intrinsic pinning of the insulating region between layers, leads to an explanation other than flux motion. However, for H parallel to the c-axis, the lack of intrinsic pinning implies that the much greater broadening is due to thermally-activated flux motion. We show experimental evidence that the associated flux motion occurs as a result of a crossover from three dimensional (3D) vortex lines to 2D independent pancake-like vortices, residing in the Cu-O layers. This 3D to 2D crossover occurs when k(B)T exceeds the Josephson coupling energy. For YBa2Cu3O7, this dimensional crossover does not occur below H(c)2, presumably because the conducting Cu-O chains short circuit the Josephson interlayer coupling. RP GRAY, KE (reprint author), ARGONNE NATL LAB,DIV MAT SCI,ARGONNE,IL 60439, USA. NR 44 TC 15 Z9 15 U1 0 U2 2 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0921-4534 J9 PHYSICA C JI Physica C PD SEP PY 1991 VL 180 IS 1-4 BP 139 EP 147 DI 10.1016/0921-4534(91)90653-G PG 9 WC Physics, Applied SC Physics GA GG786 UT WOS:A1991GG78600031 ER PT J AU BILLINGE, SJL EGAMI, T RICHARDS, DR HINKS, DC DABROWSKI, B JORGENSEN, JD VOLIN, KJ AF BILLINGE, SJL EGAMI, T RICHARDS, DR HINKS, DC DABROWSKI, B JORGENSEN, JD VOLIN, KJ TI LOCAL STRUCTURAL-CHANGE CLOSE TO TC IN ND2-XCEXCUO4-Y SO PHYSICA C LA English DT Article ID O COMPOUND SYSTEM; CRYSTAL-STRUCTURE; SUPERCONDUCTIVITY; YBA2CU3O7 AB A pair distribution function (PDF) analysis of pulsed neutron powder diffraction data has been carried out to investigate the local atomic structure of Nd2-xCexCuO4-y, x = 0.165, over a range of temperatures close to T(c) (T(c) = 22 K). Simulation of the PDFs using structural models indicate that, at all temperatures up to 50 K, the local atomic structure is significantly distorted from the T' structure. Both O(1) (in-plane) and O(2) (out-of-plane) atoms are displaced from their average sites. Furthermore, we see evidence of a structural modification occurring between 25 and 40 K. Such a change is not observed in a nonsuperconducting x = 0.2 sample down to 10 K, which suggests that this modification may be connected with the superconductivity. C1 UNIV PENN,RES STRUCT MATTER LAB,PHILADELPHIA,PA 19104. ARGONNE NATL LAB,SCI & TECHNOL CTR SUPERCONDUCT,ARGONNE,IL 60439. ARGONNE NATL LAB,DIV MAT SCI,ARGONNE,IL 60439. RP BILLINGE, SJL (reprint author), UNIV PENN,DEPT MAT SCI & ENGN,PHILADELPHIA,PA 19104, USA. NR 23 TC 31 Z9 31 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 SEP 1 PY 1991 VL 179 IS 4-6 BP 279 EP 285 DI 10.1016/0921-4534(91)92172-8 PG 7 WC Physics, Applied SC Physics GA GE034 UT WOS:A1991GE03400004 ER PT J AU SHINN, ND BARTRAM, ME SCHIRBER, JE ROGERS, JW OVERMYER, DL FISK, Z CHEONG, SW AF SHINN, ND BARTRAM, ME SCHIRBER, JE ROGERS, JW OVERMYER, DL FISK, Z CHEONG, SW TI INTERSTITIAL DOPING AND OXYGEN-EXCHANGE IN SUPERCONDUCTING LA2CUO4+DELTA SO PHYSICA C LA English DT Article ID RAY PHOTOELECTRON-SPECTROSCOPY; PHASE-SEPARATION; LA2CUO4.032; SUPEROXIDE; IDENTIFICATION; CRYSTAL AB The oxygen doping of lanthanum cuprate to generate superconductiving La2CuO4 + delta (0 < delta less-than-or-equal-to 0.032) has been studied by high-pressure, isotopic-oxygen enrichment and thermal desorption mass spectroscopy (TDMS). Isotopic data show that the additional oxygen incorporated under high pressure readily exchanges with ionic lattice oxygen during enrichment at 860 K. The thermal release of the excess oxygen from superconducting crystals above approximately 350 K is not bulk diffusion limited. An alternate explanation for the observed rapid O2(g) bursts is proposed. C1 UNIV CALIF LOS ALAMOS SCI LAB,LOS ALAMOS,NM 87545. RP SHINN, ND (reprint author), SANDIA NATL LABS,ALBUQUERQUE,NM 87185, USA. NR 18 TC 0 Z9 0 U1 0 U2 3 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0921-4534 J9 PHYSICA C JI Physica C PD SEP 1 PY 1991 VL 179 IS 4-6 BP 303 EP 310 DI 10.1016/0921-4534(91)92176-C PG 8 WC Physics, Applied SC Physics GA GE034 UT WOS:A1991GE03400008 ER PT J AU SODERHOLM, L WILLIAMS, CW WELP, U AF SODERHOLM, L WILLIAMS, CW WELP, U TI THE SUPERCONDUCTOR-RELATED OXIDES CM2CUO4 AND CM1.83TH0.17CUO4 SO PHYSICA C LA English DT Article ID NORMAL-STATE PROPERTIES; MAGNETIC-PROPERTIES; CRYSTAL-STRUCTURE; PRBA2CU3O7; CMBA2CU3O7; PR; YBA2CU3O7-DELTA; PEROVSKITE; ND2CUO4; GD2CUO4 AB We report the successful synthesis of a new member of the series R2CuO4 (R = Pr, Nd, Sm, Eu, Gd) in which R is replaced by curium (Cm; Z = 96). Systematic changes in lattice constants with the size of R are used to determine that Cm2CuO4 crystallizes in the T'-structure. Magnetic susceptibility data are consistent with Cm3+. A cusp in the susceptibility at 25 K is evidence for long range ordering of the localized Cm-moments. Attempts to synthesize an electron superconductor by the replacing some Cm3+ by Th4+, to form Cm1.83Th0.17CuO4, result in a single phase material which shows no evidence of a superconducting transition. Instead, the temperature-dependent susceptibility has a cusp at 13 K, which is indicative of the onset of long range ordering of the Cm-moments, even in this spin-diluted system. These results are discussed in terms of relevance to to the conduction behaviour of other high-T(c) related materials. RP SODERHOLM, L (reprint author), ARGONNE NATL LAB,ARGONNE,IL 60439, USA. NR 33 TC 21 Z9 21 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 SEP 1 PY 1991 VL 179 IS 4-6 BP 440 EP 446 DI 10.1016/0921-4534(91)92193-F PG 7 WC Physics, Applied SC Physics GA GE034 UT WOS:A1991GE03400025 ER PT J AU ROSE, HA DUBOIS, DF RUSSELL, D BEZZERIDES, B AF ROSE, HA DUBOIS, DF RUSSELL, D BEZZERIDES, B TI EXPERIMENTAL SIGNATURES OF LOCALIZATION IN LANGMUIR WAVE TURBULENCE SO PHYSICA D LA English DT Article; Proceedings Paper CT INTERNATIONAL WORKSHOP ON WAVE COLLAPSE PHYSICS CY MAR 20-27, 1988 CL NOVOSIBIRSK, USSR ID STIMULATED RAMAN-SCATTERING; BRILLOUIN-SCATTERING; PLASMA AB Features in certain laser-plasma and ionospheric experiments are identified with the basic properties of Langmuir wave turbulence. Also, a model of caviton nucleation is presented which leads to certain novel scaling predictions. RP ROSE, HA (reprint author), UNIV CALIF LOS ALAMOS SCI LAB,LOS ALAMOS,NM 87545, USA. NR 13 TC 6 Z9 6 U1 1 U2 1 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0167-2789 J9 PHYSICA D JI Physica D PD SEP PY 1991 VL 52 IS 1 BP 116 EP 128 DI 10.1016/0167-2789(91)90031-4 PG 13 WC Mathematics, Applied; Physics, Multidisciplinary; Physics, Mathematical SC Mathematics; Physics GA GK553 UT WOS:A1991GK55300012 ER PT J AU DAVIS, MJ MACKAY, RS SANNAMI, A AF DAVIS, MJ MACKAY, RS SANNAMI, A TI MARKOV SHIFTS IN THE HENON FAMILY SO PHYSICA D LA English DT Article ID ATTRACTORS; MAP AB We give evidence for parameter regions in which the set of bounded orbits of the Henon map is a hyperbolic set on which the map is equivalent to a subshift of finite type. C1 UNIV WARWICK,INST MATH,NONLINEAR SYST LAB,COVENTRY CV4 7AL,W MIDLANDS,ENGLAND. HOKKAIDO UNIV,DEPT MATH,SAPPORO,HOKKAIDO 060,JAPAN. RP DAVIS, MJ (reprint author), ARGONNE NATL LAB,DIV CHEM,ARGONNE,IL 60439, USA. NR 18 TC 37 Z9 37 U1 0 U2 0 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0167-2789 J9 PHYSICA D JI Physica D PD SEP PY 1991 VL 52 IS 2-3 BP 171 EP 178 DI 10.1016/0167-2789(91)90119-T PG 8 WC Mathematics, Applied; Physics, Multidisciplinary; Physics, Mathematical SC Mathematics; Physics GA GK161 UT WOS:A1991GK16100003 ER PT J AU SEGUY, P YU, PY AF SEGUY, P YU, PY TI OPTICAL-EXCITATION OF DX CENTERS IN GAALAS ALLOYS DOPED WITH SI AND TE SO PHYSICA STATUS SOLIDI B-BASIC RESEARCH LA English DT Article ID NEGATIVE-U PROPERTY; ELECTRON-PARAMAGNETIC-RESONANCE; PERSISTENT PHOTOCONDUCTIVITY; ALXGA1-XAS ALLOYS; DONOR; GAAS AB The effect of light illumination on the deep level transient spectroscopy (DLTS)and constant temperature capacitance transient spectra of DX centers in GaAlAs alloys doped with Si and Te is studied. The experimental DLTS spectra are compared with theoretical spectra based on a model in which the only effect of light is to photoionize the DX centers. The calculated spectra reproduce satisfactorily the experimental spectra only in the Te doped samples. In Si doped samples the calculated spectra cannot reproduce the light-induced peak reported recently by Jia et al. Thus the results confirm that this peak may be associated with a light-induced shallow metastable center related to Si in GaAlAs. The identification of this shallow metastable state based on the present work and other recent experimental and theoretical investigations is discussed. C1 UNIV CALIF BERKELEY,LAWRENCE BERKELEY LAB,DIV MAT SCI,BERKELEY,CA 94720. RP SEGUY, P (reprint author), UNIV CALIF BERKELEY,DEPT PHYS,BERKELEY,CA 94720, USA. NR 20 TC 3 Z9 3 U1 3 U2 5 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 SEP PY 1991 VL 167 IS 1 BP 177 EP 187 DI 10.1002/pssb.2221670120 PG 11 WC Physics, Condensed Matter SC Physics GA GM418 UT WOS:A1991GM41800019 ER PT J AU COHEN, JS AF COHEN, JS TI IMPROVED ADIABATIC CALCULATION OF MUONIC-HYDROGEN-ATOM CROSS-SECTIONS .3. HYPERFINE TRANSITIONS IN ASYMMETRIC COLLISIONS SO PHYSICAL REVIEW A LA English DT Article ID BINDING-ENERGIES; DT-MU; FUSION; STATES AB Cross sections for transitions between hyperfine-structure states of muonic hydrogen atoms in asymmetric collisions have been calculated for the first time. The interaction is described by the improved adiabatic representation. s waves dominate the cross sections except for the remarkable case of t-mu (up-up) + d where the p wave dominates even at liquid-hydrogen temperature. The quenching rates for the collisions in which the muon resides on the heavier isotope are lambda [d-mu (up-up) + p --> d-mu (up-down) + p] = 5.5 x 10(2) (6.4 x 10(2)) s-1, lambda [t-mu (up-up) + p --> t-mu (up-down) + p] = 3.1 x 10(2) (3.2 x 10(2)) s-1, and lambda [t-mu (up-up) + d --> t-mu (up-down) + d] = 7.5 x 10(1) (7.3 x 10(2)) s-1 at 23 K (232 K) and liquid-hydrogen density. Although some experimental observations have been attributed to hyperfine quenching in asymmetric collisions, these rates are probably too slow to have had an effect in previous experiments. However, the rate for t-mu (up-up) + d is somewhat uncertain since it is found to be extraordinarily sensitive to the potential. As a by-product of this work, an independent value of the hyperfine correction to the binding energy of td-mu (J = 1, upsilon = 1) is obtained: DELTA-epsilon-hfs = -36.1 me V for the lowest hyperfine state. RP COHEN, JS (reprint author), UNIV CALIF LOS ALAMOS SCI LAB,DIV THEORET,LOS ALAMOS,NM 87545, USA. NR 27 TC 11 Z9 11 U1 0 U2 0 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 1050-2947 J9 PHYS REV A JI Phys. Rev. A PD SEP 1 PY 1991 VL 44 IS 5 BP 2836 EP 2845 DI 10.1103/PhysRevA.44.2836 PG 10 WC Optics; Physics, Atomic, Molecular & Chemical SC Optics; Physics GA GE936 UT WOS:A1991GE93600013 ER PT J AU CLARK, REH CSANAK, G ABDALLAH, J AF CLARK, REH CSANAK, G ABDALLAH, J TI THEORETICAL-STUDIES ON THE ELECTRON-IMPACT EXCITATION OF NEUTRAL MAGNESIUM SO PHYSICAL REVIEW A LA English DT Article ID DIFFERENTIAL CROSS-SECTIONS; CORRELATION PARAMETERS; INTERMEDIATE ENERGIES; RESONANCE LINES; SCATTERING; ATOMS; STRENGTHS; COHERENCE; BARIUM; HELIUM AB We used the distorted-wave approximation (DWA) and first-order many-body theory (FOMBT) for the calculation of integral cross sections (ICS's), differential cross sections (DCS's), and electron-impact coherence parameters (EICP's) for electron-impact excitation of neutral magnesium for several transitions. In the case of 3 1P excitation, we studied the basis-set dependence of the ICS's, DCS's, and EICP's, we investigated the effect of unitarization on these quantities, and we compared the DWA with FOMBT. We also studied the principal-quantum-number dependence of the EICP's for n 1p (n = 3,4,5,6) excitation. RP CLARK, REH (reprint author), UNIV CALIF LOS ALAMOS SCI LAB,LOS ALAMOS,NM 87545, USA. NR 34 TC 45 Z9 45 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 SEP 1 PY 1991 VL 44 IS 5 BP 2874 EP 2882 DI 10.1103/PhysRevA.44.2874 PG 9 WC Optics; Physics, Atomic, Molecular & Chemical SC Optics; Physics GA GE936 UT WOS:A1991GE93600018 ER PT J AU LENGSFIELD, BH RESCIGNO, TN AF LENGSFIELD, BH RESCIGNO, TN TI ELECTRON-MOLECULE CLOSE COUPLING WITH CORRELATED TARGET WAVE-FUNCTIONS - APPLICATION TO IMPACT DISSOCIATION OF F2 SO PHYSICAL REVIEW A LA English DT Article ID KOHN VARIATIONAL METHOD; INTERMEDIATE ENERGIES; SCATTERING; EXCITATION; COLLISIONS; STATES AB An analysis of the close-coupling method as it is traditionally formulated for electron-scattering problems shows that it can give rise to spurious resonances at intermediate energies when multiconfiguration target states are used. These resonances are associated with excited states of the target that are not explicitly included in the close-coupling expansion. We develop a modification of the close-coupling technique that allows one to isolate and systematically eliminate terms from the total wave function which are responsiblefor the spurious behavior. We have applied this technique to the study of electron-impact dissociation of F2 through its two lowest excited states. The complex Kohn variational calculations we have performed on this system incorporate accurate, multiconfiguration descriptions of the target wave functions. RP LENGSFIELD, BH (reprint author), UNIV CALIF LAWRENCE LIVERMORE NATL LAB,POB 808,LIVERMORE,CA 94550, USA. NR 23 TC 31 Z9 31 U1 0 U2 4 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 SEP 1 PY 1991 VL 44 IS 5 BP 2913 EP 2920 DI 10.1103/PhysRevA.44.2913 PG 8 WC Optics; Physics, Atomic, Molecular & Chemical SC Optics; Physics GA GE936 UT WOS:A1991GE93600023 ER PT J AU KEMMLER, J BURGDORFER, J REINHOLD, CO AF KEMMLER, J BURGDORFER, J REINHOLD, CO TI THEORY OF THE L-STATE POPULATION OF RYDBERG STATES FORMED IN ION-SOLID COLLISIONS SO PHYSICAL REVIEW A LA English DT Article ID HIGHLY EXCITED-STATES; EXCITATION; OXYGEN; C+ AB The experimentally observed high-l-state population of ions excited in ion-solid interactions differs sharply from l-state populations produced in ion-atom collisions. We have studied the population dynamics of electronic excitation and transport within the framework of a classical transport theory for O2+ (2-MeV/u) ions traversing C foils. The resulting delayed-photon-emission intensities are found to be in very good agreement with experiment. Initial phase-space conditions have been obtained from both classical-trajectory Monte Carlo calculations and random initial distributions. We find evidence that the very-high-l-state populations produced in ion-solid collisions are the result of a diffusion to high-l-states under the influence of multiple scattering in the bulk of the solid. C1 OAK RIDGE NATL LAB,OAK RIDGE,TN 37831. RP KEMMLER, J (reprint author), UNIV TENNESSEE,KNOXVILLE,TN 37996, USA. OI Reinhold, Carlos/0000-0003-0100-4962 NR 22 TC 42 Z9 42 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 SEP 1 PY 1991 VL 44 IS 5 BP 2993 EP 3000 DI 10.1103/PhysRevA.44.2993 PG 8 WC Optics; Physics, Atomic, Molecular & Chemical SC Optics; Physics GA GE936 UT WOS:A1991GE93600032 ER PT J AU MCCORMACK, EF PRATT, ST DEHMER, JL DEHMER, PM AF MCCORMACK, EF PRATT, ST DEHMER, JL DEHMER, PM TI ANALYSIS OF THE 8F, 9F, AND 10F, UPSILON=1 RYDBERG STATES OF N2 SO PHYSICAL REVIEW A LA English DT Article ID RESONANT MULTIPHOTON IONIZATION; INFRARED-LASER SPECTROSCOPY; HIGH-RESOLUTION; MOLECULAR NITROGEN; H-2; AUTOIONIZATION; SERIES; N-2; NF; NO AB The autoionizing (X2-SIGMA-g+) 8f, 9f, and 10f, upsilon = 1 states of N2 have been studied by using double-resonance ionization spectroscopy via numerous rotational levels of the a 1-PI-g, upsilon' = 5 state. These nf states lie in a complex region of the spectrum that also contains transitions to high vibrational levels of the b'1-SIGMA-u+ valence state and Rydberg states that converge to the X 2-SIGMA-g+, A 2-pi-u, and B 2-SIGMA-u+ states of the ion. A long-range interaction model, which is based on the interaction of the Rydberg electron with the polarizability and quadrupole moment of the N2+ ion core, has been used to interpret the f-state structure and to identify the extent of perturbations due to interactions with nearby states. A generalized least-squares fit of the model to the energies of the unperturbed 8f state yields an effective quadrupole moment of (3.2 +/- 0.1)ea0(2) and an isotropic polarizability of (16.1 +/- 0.4)a0(3) for the X 2-SIGMA-g+, upsilon+ = 1 state of the ion. In addition, a new state that is observed to perturb the 9f, upsilon = 1 state is tentatively identified as the previously unobserved (A 2-PI(u)3d-pi-1-DELTA-u, upsilon = 2 state. The results presented here complete the interpretation of the single-photon absorption spectrum of N2 from the first ionization potential at approximately 125 667 to approximately 126 850 cm-1. RP MCCORMACK, EF (reprint author), ARGONNE NATL LAB, ARGONNE, IL 60439 USA. NR 41 TC 26 Z9 26 U1 1 U2 4 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 SEP 1 PY 1991 VL 44 IS 5 BP 3007 EP 3015 DI 10.1103/PhysRevA.44.3007 PG 9 WC Optics; Physics, Atomic, Molecular & Chemical SC Optics; Physics GA GE936 UT WOS:A1991GE93600034 ER PT J AU SCHNEIDER, D CLARK, MW PENETRANTE, BM MCDONALD, J DEWITT, D BARDSLEY, JN AF SCHNEIDER, D CLARK, MW PENETRANTE, BM MCDONALD, J DEWITT, D BARDSLEY, JN TI PRODUCTION OF HIGH-CHARGE-STATE THORIUM AND URANIUM IONS IN AN ELECTRON-BEAM ION TRAP SO PHYSICAL REVIEW A LA English DT Article ID EXCITATION CROSS-SECTIONS; RECOMBINATION; ATOMS AB High-charge-state thorium (up to 80+) and uranium (up to 70+) ions have been extracted from an electron-beam ion trap (EBIT). The ions were produced after injecting low-charge-state thorium and uranium ions initially from a metallic vapor vacuum arc ion source into the trap. The extracted ions from the EBIT provide microsecond-wide ion-beam pulses of about 10(4) ions per second. The production and loss rates are estimated from modeling calculations and are compared to the measured extracted ion rates. RP SCHNEIDER, D (reprint author), UNIV CALIF LAWRENCE LIVERMORE NATL LAB,DIV HIGH TEMP PHYS,LIVERMORE,CA 94550, USA. NR 20 TC 68 Z9 69 U1 0 U2 5 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 1050-2947 J9 PHYS REV A JI Phys. Rev. A PD SEP 1 PY 1991 VL 44 IS 5 BP 3119 EP 3124 DI 10.1103/PhysRevA.44.3119 PG 6 WC Optics; Physics, Atomic, Molecular & Chemical SC Optics; Physics GA GE936 UT WOS:A1991GE93600043 ER PT J AU HARTMANN, FX NOID, DW SHARON, YY AF HARTMANN, FX NOID, DW SHARON, YY TI MODEL OF NUCLEAR-EXCITATION BY ELECTRONIC MOTION IN INTENSE LASER FIELDS SO PHYSICAL REVIEW A LA English DT Article ID SYNCHROTRON RADIATION; INTERNAL-CONVERSION; BRAGG SCATTERING; RAY LASERS; TRANSITION; PLASMA; TH-229; DECAY; STATE AB A simple model of coupled electronic and collective nuclear motion is used to study energy-transfer processes in the presence of intense short-wavelength laser fields. The complete Hamiltonian of the model includes distinct nuclear, electronic, and laser-field terms. A semiclassical method of extracting spectral information from the generated trajectories of the Hamiltonian is used to calculate laser-electronic-nuclear energy-transfer rates. The nuclear term describes a deformed heavy nucleus; it sufficiently treats the collective nuclear motion, which is lower in frequency than that which would be given by an individual-particle nucleon model. We specifically report on the dynamics of this model, and on the energy transfer that ensue, in the presence of an x-ray laser field, as a function of the electron radial distance. This general problem is of basic interest in the studies of laser-driven nuclear excitation. C1 OAK RIDGE NATL LAB,DIV CHEM,OAK RIDGE,TN 37831. STOCKTON STATE COLL,POMONA,NJ 08240. PRINCETON UNIV,DEPT PHYS,PRINCETON,NJ 08544. NR 37 TC 8 Z9 8 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 SEP 1 PY 1991 VL 44 IS 5 BP 3210 EP 3221 DI 10.1103/PhysRevA.44.3210 PG 12 WC Optics; Physics, Atomic, Molecular & Chemical SC Optics; Physics GA GE936 UT WOS:A1991GE93600055 ER PT J AU CLARO, F AF CLARO, F TI COLLECTIVE SURFACE-MODES IN A FRACTAL CLUSTER OF SPHERES SO PHYSICAL REVIEW B LA English DT Article ID OPTICAL-PROPERTIES; INHOMOGENEOUS-MEDIA; ABSORPTION; PARTICLES; AGGREGATION; DIFFRACTION; SPECTRUM AB We present a theory for finding the collective surface modes in the quasistatic approximation for a fractal cluster of spheres constructed in a recursive manner. The surface-mode positions and strengths are given in terms of the spectral representation for the polarizability of the cluster. Calculations using the dipole approximation for a cluster constructed recursively from an octahedral arrangement of six spheres show that the surface-mode spectrum is approximately self-similar. We calculate the distribution of scaling indices, f (alpha), for this spectrum as a function of the fractal dimension of the cluster in Euclidean space. C1 IOWA STATE UNIV SCI & TECHNOL,AMES LAB,AMES,IA 50011. IOWA STATE UNIV SCI & TECHNOL,DEPT PHYS & ASTRON,AMES,IA 50011. RP CLARO, F (reprint author), PONTIFICIA UNIV CATOLICA CHILE,FAC FIS,CASILLA 306,SANTIAGO 22,CHILE. OI claro, francisco/0000-0003-2122-6992 NR 30 TC 23 Z9 23 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 SEP 1 PY 1991 VL 44 IS 9 BP 4109 EP 4116 DI 10.1103/PhysRevB.44.4109 PG 8 WC Physics, Condensed Matter SC Physics GA GD967 UT WOS:A1991GD96700005 ER PT J AU DELEON, JM REHR, JJ ZABINSKY, SI ALBERS, RC AF DELEON, JM REHR, JJ ZABINSKY, SI ALBERS, RC TI ABINITIO CURVED-WAVE X-RAY-ABSORPTION FINE-STRUCTURE SO PHYSICAL REVIEW B LA English DT Article ID NEAR-EDGE STRUCTURE; STRUCTURE SPECTROSCOPY; STRUCTURE AMPLITUDES; PHASE FUNCTIONS; SCATTERING; APPROXIMATION; SPECTRA; ENERGY; EXAFS; CRYSTALS AB The most important elements of ab initio calculations of x-ray-absorption fine structure (XAFS) are studied. To obtain accurate results without ad hoc adjustable parameters, we find it essential to include (i) curved-wave effects, (ii) a complex, energy-dependent self-energy, (iii) an approximate molecular potential, and (iv) a fixed energy reference for the photoelectron wave number. Based on these findings, an automated code has been developed for ab initio calculations of single-scattering XAFS, in which curved-wave effects are treated exactly in terms of effective backscattering amplitudes, inelastic losses and self-energy shifts are incorporated with use of a Hedin-Lundqvist self-energy, an automated relativistic overlapping-atom muffin-tin potential is used, and the energy threshold is estimated from electron-gas theory. The efficiency of the code is made possible by analytic expressions for the Hedin-Lundqvist self-energy. This code replaces existing tables of XAFS phases and scattering amplitudes and yields reliable theoretical XAFS standards for arbitrary pairs of atoms throughout the Periodic Table (Z less-than-or-equal-to 94). These results are comparable to those from self-consistent calculations and are valid to within about 20 eV of the absorption edge. Comparisons with experiment are presented for Cu, Ge, Pt, Br2, and GeCl4. The calculated XAFS amplitudes are found to be accurate to within 15%; XAFS phases are accurate to within 0.2 rad; and nearest-neighbor distances are typically accurate to within 0.02 angstrom. C1 UNIV WASHINGTON,DEPT PHYS,SEATTLE,WA 98195. UNIV CALIF LOS ALAMOS SCI LAB,DIV THEORET,LOS ALAMOS,NM 87545. NR 56 TC 701 Z9 701 U1 7 U2 41 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 SEP 1 PY 1991 VL 44 IS 9 BP 4146 EP 4156 PG 11 WC Physics, Condensed Matter SC Physics GA GD967 UT WOS:A1991GD96700009 ER PT J AU MCNEIL, LE GRIMSDITCH, M AF MCNEIL, LE GRIMSDITCH, M TI ELASTIC-CONSTANTS OF AS2S3 SO PHYSICAL REVIEW B LA English DT Article ID CRYSTALLINE AS2S3; GRAPHITE; PRESSURE AB We have used Brillouin scattering to measure ten of the thirteen independent elastic constants of crystalline As2S3. We find that the phonon propagation within the layer plane is largely controlled by the orthorhombic symmetry of the layer rather than the monoclinic symmetry of the crystal. The stiffness within the plane displays a large anisotropy, and the smaller of the stiffnesses within the plane is less than that along the axis perpendicular to the plane, an unexpected result for a layered crystal. For phonons propagating near the [001] direction the two branches of the velocity show a "mode repulsion" and exchange their polarizations. In this direction the velocity of the shear wave is larger than that of the compressional wave. C1 UNIV N CAROLINA,DEPT PHYS & ASTRON,CHAPEL HILL,NC 27599. RP MCNEIL, LE (reprint author), ARGONNE NATL LAB,DIV MAT SCI,ARGONNE,IL 60439, USA. NR 20 TC 5 Z9 5 U1 1 U2 2 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 0163-1829 J9 PHYS REV B JI Phys. Rev. B PD SEP 1 PY 1991 VL 44 IS 9 BP 4174 EP 4177 DI 10.1103/PhysRevB.44.4174 PG 4 WC Physics, Condensed Matter SC Physics GA GD967 UT WOS:A1991GD96700013 ER PT J AU ABELL, GC COWGILL, DF AF ABELL, GC COWGILL, DF TI LOW-TEMPERATURE HE-3 NMR-STUDIES IN AGED PALLADIUM TRITIDE SO PHYSICAL REVIEW B LA English DT Article ID HYDROGEN; BUBBLES; HELIUM AB Experimental results from a NMR study of He-3 in nanometer-sized microbubbles in aged palladium tritide over the temperature range 4-300 K are presented. A determination of the rigid-lattice-line-shape second moment at 4 K provides a value for the density of He-3 that is in good agreement with the value inferred for the same sample from an analysis of He-3 spin-lattice relaxation data over the range 50-300 K. This latter analysis is based on the hypothesis of a melting transition for a distribution of densities, and assumes that the bulk helium equation of state applies to helium in the nanometer-sized bubbles. This latter assumption is supported by the agreement between the two independent density determinations. Line-shape analyses reveal narrowing of the He-3 spectrum at about 35 K, which agrees with a prediction of motional narrowing based on an extrapolation of He-3 diffusivity data determined over the range 100-250 K in an earlier study of aged palladium tritide. The observation of coexisting broad and narrow components in the free-induction decay at 40 K provides direct evidence for a distribution of He-3 densities in aged palladium tritide. Because the melting temperature and the rigid-lattice second moment are both strong functions of density, the NMR techniques described here provide a sensitive measure of the density distribution and related properties. C1 SANDIA NATL LABS,LIVERMORE,CA 94550. RP ABELL, GC (reprint author), EG&G,MOUND APPL TECHNOL,MIAMISBURG,OH 45342, USA. NR 22 TC 9 Z9 9 U1 4 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 SEP 1 PY 1991 VL 44 IS 9 BP 4178 EP 4184 DI 10.1103/PhysRevB.44.4178 PG 7 WC Physics, Condensed Matter SC Physics GA GD967 UT WOS:A1991GD96700014 ER PT J AU ANDRAKA, B KIM, JS STEWART, GR FISK, Z AF ANDRAKA, B KIM, JS STEWART, GR FISK, Z TI CECU4AL AND CECU2ZN2AL - VERY-HEAVY-FERMION SYSTEMS IN HIGH MAGNETIC-FIELDS SO PHYSICAL REVIEW B LA English DT Article ID CEAL3 AB CeCu4Al and CeCu2Zn2Al are heavy-fermion systems with extremely enhanced C/T (the specific heat divided by temperature) values of 2.3 and 1.8 J/K2, respectively, as T --> 0 K. The field dependence of the low-temperature specific heat is also extreme: At 11 T, C of CeCu4Al is reduced by more than a factor of 5 and at 12.5 T, C of CeCu2Zn2Al is suppressed by a factor of about 7. Magnetic-field-caused changes of the specific heat of CeCu4Al are consistent with a single-ion Kondo model. Magnetic correlations are at least partially responsible for the enhanced low-temperature specific heat of CeCu2Zn2Al. C1 UNIV CALIF LOS ALAMOS SCI LAB,LOS ALAMOS,NM 87545. UNIV AUGSBURG,W-8900 AUGSBURG,GERMANY. RP ANDRAKA, B (reprint author), UNIV FLORIDA,DEPT PHYS,GAINESVILLE,FL 32611, USA. NR 21 TC 20 Z9 20 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 SEP 1 PY 1991 VL 44 IS 9 BP 4371 EP 4373 DI 10.1103/PhysRevB.44.4371 PG 3 WC Physics, Condensed Matter SC Physics GA GD967 UT WOS:A1991GD96700035 ER PT J AU WU, R FREEMAN, AJ AF WU, R FREEMAN, AJ TI ANTIFERROMAGNETIC ORDERING OF FE/RU(0001) SO PHYSICAL REVIEW B LA English DT Article ID THIN-FILM MAGNETISM; PLANAR XY MODEL; 2 DIMENSIONS; MAGNETORESISTANCE; EXCHANGE; SURFACES; SUPERLATTICES; ANISOTROPY; INTERFACES; FE(001) AB The structural, electronic, and magnetic properties of the Fe/Ru(0001) system were determined by using the local-density total-energy full-potential linearized augmented-plane-wave energy-band method. Structurally, Fe atoms are found to occupy the hcp sites on the Ru(0001) substrate. Compared with the average of their bulk values, the nearest Fe-Ru distance contracts about 6% for the paramagnetic case but expands 1% for the ferromagnetic and the antiferromagnetic configurations, indicating the strong effect of magnetism and the lattice geometry. As the result of the strong overlayer-substrate hybridization, the Fe atoms, which are coupled ferromagnetically in the case of the corresponding free-standing Fe monolayer, favor antiferromagnetic coupling for Fe/Ru(0001). The predicted antiferromagnetic coupling appears to explain the observation by Liu and Bader that Fe overlayers on Ru(0001) are "magnetically dead" when the number of Fe layers is less than 2. C1 ARGONNE NATL LAB,DEPT PHYS & ASTRON,ARGONNE,IL 60439. RP WU, R (reprint author), NORTHWESTERN UNIV,DEPT PHYS & ASTRON,EVANSTON,IL 60208, USA. RI Wu, Ruqian/C-1395-2013 OI Wu, Ruqian/0000-0002-6156-7874 NR 31 TC 32 Z9 32 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 SEP 1 PY 1991 VL 44 IS 9 BP 4449 EP 4454 DI 10.1103/PhysRevB.44.4449 PG 6 WC Physics, Condensed Matter SC Physics GA GD967 UT WOS:A1991GD96700046 ER PT J AU BARBEE, TW COHEN, ML PENN, DR AF BARBEE, TW COHEN, ML PENN, DR TI EXPERIMENTAL CONSTRAINTS ON SOME MECHANISMS FOR HIGH-TEMPERATURE SUPERCONDUCTIVITY SO PHYSICAL REVIEW B LA English DT Article ID HIGH-TC SUPERCONDUCTORS; CU-O SYSTEM; OXYGEN ISOTOPE; ENERGY-GAP; YBA2CU3O7; OXIDES; HEAT; LA1.85SR0.15CUO4; BI2SR2CACU2O8; CONDUCTIVITY AB Since its discovery, many mechanisms have been suggested to explain the phenomenon of high-temperature superconductivity in oxides. We propose that experimental data, along with theoretical models, can place constraints on or exclude many of these mechanisms. The isotope shift-alpha, the transition temperature T(c), the ratio of the electronic-specific-heat jump to the normal-state specific heat DELTA-C/gamma T(c), and the superconducting gap ratio 2-DELTA/k(B)T(c) are considered. We find limits on the applicability of solely phonon-based and combined phonon-electronic mechanisms. C1 UNIV CALIF BERKELEY LAWRENCE BERKELEY LAB,DIV MAT & CHEM SCI,BERKELEY,CA 94720. NATL INST STAND & TECHNOL,DIV RADIAT PHYS,GAITHERSBURG,MD 20899. RP BARBEE, TW (reprint author), UNIV CALIF BERKELEY,DEPT PHYS,BERKELEY,CA 94720, USA. NR 51 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 SEP 1 PY 1991 VL 44 IS 9 BP 4473 EP 4479 DI 10.1103/PhysRevB.44.4473 PG 7 WC Physics, Condensed Matter SC Physics GA GD967 UT WOS:A1991GD96700050 ER PT J AU NUNEZ, L ROGERS, RD CRABTREE, GW WELP, U VANDERVOORT, K UMEZAWA, A FANG, Y AF NUNEZ, L ROGERS, RD CRABTREE, GW WELP, U VANDERVOORT, K UMEZAWA, A FANG, Y TI MAGNETIC AND STRUCTURAL-PROPERTIES OF FE IN SINGLE-CRYSTALS OF YBA2CU3-XFEXO7-DELTA SO PHYSICAL REVIEW B LA English DT Article ID SUPERCONDUCTOR YBA2CU3O7-DELTA; MOSSBAUER-SPECTROSCOPY; OXYGEN; IRON; YBA2(CU1-XFEX)3O7-DELTA; MICROSTRUCTURE; SUBSTITUTION; TRANSITION; BEHAVIOR; COPPER AB Magnetization and lattice-constant measurements were done on four single crystals of YBa2Cu(3-x)Fe(x)O7-delta with Fe concentrations of x = 0.06, 0.09, 0.15, and 0.24 to determine the structural and normal-state properties. Measurements of magnetization as a function of temperature were done in a temperature range between 90 and 300 K and analyzed using a Curie-Weiss law with a temperature-independent background. The effective magnetic moment obtained corresponds to a low spin state of Fe3+ with a magnitude of 2.18-mu-B. Magnetic anisotropy between the ab plane and the c direction is only present for the concentration of x = 0.06 and is attributed to the various oxygen environments surrounding the iron. For concentrations larger than x = 0.06, the moment on Fe is isotropic and Curie-Weiss fits predict uniform antiferromagnetic ordering. Structural measurements exhibit an orthorhombic-tetragonal transition at an Fe concentration of x = 0.15, similar to that observed in the polycrystalline material. C1 ARGONNE NATL LAB,DIV MAT SCI,ARGONNE,IL 60439. RP NUNEZ, L (reprint author), NO ILLINOIS UNIV,DEPT CHEM,DE KALB,IL 60115, USA. RI Rogers, Robin/C-8265-2013 OI Rogers, Robin/0000-0001-9843-7494 NR 32 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 0163-1829 J9 PHYS REV B JI Phys. Rev. B PD SEP 1 PY 1991 VL 44 IS 9 BP 4526 EP 4531 PG 6 WC Physics, Condensed Matter SC Physics GA GD967 UT WOS:A1991GD96700055 ER PT J AU SHI, DL XU, M AF SHI, DL XU, M TI NONLINEAR LOGARITHMIC TIME DECAY OF MAGNETIZATION IN A SINGLE-CRYSTAL OF BI2SR2CACU2OX SO PHYSICAL REVIEW B LA English DT Article ID CU-O CRYSTAL; FLUX CREEP; IRREVERSIBILITY; SUPERCONDUCTORS; YBA2CU3O7 AB Nonlinear logarithmic time decay of magnetization has been observed over a long measuring time period (t = 22 h) for a single crystal of Bi2Sr2CaCu2O(x). At relatively low temperatures (T = 12 K) linear ln(t) decay of the magnetization is observed for field (= 1 kG) parallel to the c axis, which can be described well by the Anderson-Kim model. However, at high temperatures (T > 26 K) the magnetization exhibits nonlinear logarithmic time near the irreversibility line. Possible connections between the experimental data and current theories are discussed. C1 GEORGIA INST TECHNOL,SCH PHYS,ATLANTA,GA 30332. RP SHI, DL (reprint author), ARGONNE NATL LAB,DIV MAT SCI,ARGONNE,IL 60439, USA. NR 14 TC 52 Z9 53 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 SEP 1 PY 1991 VL 44 IS 9 BP 4548 EP 4552 DI 10.1103/PhysRevB.44.4548 PG 5 WC Physics, Condensed Matter SC Physics GA GD967 UT WOS:A1991GD96700058 ER PT J AU STRANDBURG, KJ AF STRANDBURG, KJ TI ENTROPY OF A 3-DIMENSIONAL RANDOM-TILING QUASI-CRYSTAL SO PHYSICAL REVIEW B LA English DT Note ID QUASI-CRYSTAL AB A numerical calculation of the entropy of a three-dimensional randomly rearranged Penrose tiling is described. The entropy per tile is obtained to be 0.24 +/- 0.02. C1 NORTHWESTERN UNIV,DEPT PHYS & ASTRON,EVANSTON,IL 60208. RP STRANDBURG, KJ (reprint author), ARGONNE NATL LAB,DIV MAT SCI,ARGONNE,IL 60439, USA. NR 20 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 0163-1829 J9 PHYS REV B JI Phys. Rev. B PD SEP 1 PY 1991 VL 44 IS 9 BP 4644 EP 4646 DI 10.1103/PhysRevB.44.4644 PG 3 WC Physics, Condensed Matter SC Physics GA GD967 UT WOS:A1991GD96700070 ER PT J AU ARONSON, MC DIERKER, SB DENNIS, BS CHEONG, SW FISK, Z AF ARONSON, MC DIERKER, SB DENNIS, BS CHEONG, SW FISK, Z TI PRESSURE-DEPENDENCE OF THE SUPEREXCHANGE INTERACTION IN ANTIFERROMAGNETIC LA2CUO4 SO PHYSICAL REVIEW B LA English DT Note ID HIGH-TC SUPERCONDUCTIVITY; OXIDES; SCATTERING; FLUCTUATIONS; EXCITATIONS AB Using high-pressure Raman scattering, we have directly measured the pressure dependence of the in-plane superexchange interaction J in antiferromagnetic La2CuO4 between 1 bar and 100 kbar. We find that J has a substantially weaker pressure dependence than in conventional magnets. We also show that the Hubbard-model parameters describing the low-energy electronic structure are significantly influenced by out-of-plane compositional and structural variations. Finally, we show that the relationship between J and the Neel temperature T(N) is poorly described by current theory. C1 AT&T BELL LABS,MURRAY HILL,NJ 07974. UNIV CALIF LOS ALAMOS SCI LAB,LOS ALAMOS,NM 87545. RP ARONSON, MC (reprint author), UNIV MICHIGAN,RANDALL LAB PHYS,ANN ARBOR,MI 48109, USA. NR 34 TC 47 Z9 47 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 SEP 1 PY 1991 VL 44 IS 9 BP 4657 EP 4660 DI 10.1103/PhysRevB.44.4657 PG 4 WC Physics, Condensed Matter SC Physics GA GD967 UT WOS:A1991GD96700074 ER PT J AU SCHIRBER, JE OVERMYER, DL CARLSON, KD WILLIAMS, JM KINI, AM WANG, HH CHARLIER, HA LOVE, BJ WATKINS, DM YACONI, GA AF SCHIRBER, JE OVERMYER, DL CARLSON, KD WILLIAMS, JM KINI, AM WANG, HH CHARLIER, HA LOVE, BJ WATKINS, DM YACONI, GA TI PRESSURE-TEMPERATURE PHASE-DIAGRAM, INVERSE ISOTOPE EFFECT, AND SUPERCONDUCTIVITY IN EXCESS OF 13-K IN KAPPA-(BEDT-TTF)2CU[N(CN)2]CL, WHERE BEDT-TTF IS BIS(ETHYLENEDITHIO)TETRATHIAFULVALENE SO PHYSICAL REVIEW B LA English DT Note ID ORGANIC SUPERCONDUCTOR; CRITICAL-FIELD; TC; DEPENDENCE; MECHANISM; ANALOG AB The pressure-temperature phase diagram of the highest-T(c) organic superconductor, kappa-(BEDT-TTF)2Cu[N(CN)2]Cl is determined, where BEDT-TTF is bis(ethylenedithio)tetrathiafulvalene. Semiconducting, insulating, metallic, and superconducting regimes are seen at pressures below 1 kbar. Superconductivity at 12.5 K and 0.3 kbar increases by 0.5-1.5 K upon deuteration of BEDT-TTF, in striking contrast to the normal isotope effect determined previously for kappa-(BEDT-TTF)2Cu[N(CN)2]Br. C1 ARGONNE NATL LAB,DIV CHEM,ARGONNE,IL 60439. ARGONNE NATL LAB,DIV MAT SCI,ARGONNE,IL 60439. UNIV WISCONSIN,STEVENS POINT,WI 54481. MIAMI UNIV,OXFORD,OH 45056. FLORIDA INST TECHNOL,MELBOURNE,FL 32901. PENN STATE UNIV,UNIVERSITY PK,PA 16802. RP SCHIRBER, JE (reprint author), SANDIA NATL LABS,ALBUQUERQUE,NM 87185, USA. RI Kini, Aravinda/F-4467-2012 NR 21 TC 78 Z9 78 U1 1 U2 7 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 0163-1829 J9 PHYS REV B JI Phys. Rev. B PD SEP 1 PY 1991 VL 44 IS 9 BP 4666 EP 4666 DI 10.1103/PhysRevB.44.4666 PG 1 WC Physics, Condensed Matter SC Physics GA GD967 UT WOS:A1991GD96700077 ER PT J AU LIN, HQ AF LIN, HQ TI DILUTE GAS OF ELECTRON PAIRS IN THE T-J MODEL SO PHYSICAL REVIEW B LA English DT Note ID SUPERCONDUCTIVITY; SYSTEM AB The bound state of electron pairs in the t-J model is investigated. It is shown that for 2t < J < 3.828t the hole-rich phase is a low-density superfluid of electron pairs. RP LIN, HQ (reprint author), UNIV CALIF LOS ALAMOS SCI LAB,CTR NONLINEAR STUDIES,LOS ALAMOS,NM 87545, USA. NR 6 TC 27 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 SEP 1 PY 1991 VL 44 IS 9 BP 4674 EP 4676 DI 10.1103/PhysRevB.44.4674 PG 3 WC Physics, Condensed Matter SC Physics GA GD967 UT WOS:A1991GD96700079 ER PT J AU SOUKOULIS, CM GREST, GS AF SOUKOULIS, CM GREST, GS TI LOCALIZATION IN 2-DIMENSIONAL QUANTUM PERCOLATION SO PHYSICAL REVIEW B LA English DT Note ID SIZE SCALING APPROACH; ANDERSON LOCALIZATION; RENORMALIZATION-GROUP; DISORDERED-SYSTEMS; 3-DIMENSIONAL SYSTEMS; DILUTE SYSTEMS; MOBILITY EDGE; 2 DIMENSIONS; 3 DIMENSIONS; STATES AB The quantum site and bond percolation problem, which is defined by a disordered tight-binding Hamiltonian with a binary probability distribution, is studied using finite-size-scaling methods. For the simple square lattice, we find that all states are exponentially localized for any amount of disorder, in agreement with the scaling theory of localization and in disagreement with recent claims of a localization transition in two dimensions. The localization length-lambda is given by A exp{B[p/(1 - p)]y} with y very close to 0.5 and p the probability that a site or a bond is present. C1 IOWA STATE UNIV SCI & TECHNOL,DEPT PHYS & ASTRON,AMES,IA 50011. EXXON RES & ENGN CO,CORP RES SCI LAB,ANNANDALE,NJ 08801. RP SOUKOULIS, CM (reprint author), IOWA STATE UNIV SCI & TECHNOL,AMES LAB,AMES,IA 50011, USA. RI Soukoulis, Costas/A-5295-2008 NR 41 TC 43 Z9 43 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 SEP 1 PY 1991 VL 44 IS 9 BP 4685 EP 4688 DI 10.1103/PhysRevB.44.4685 PG 4 WC Physics, Condensed Matter SC Physics GA GD967 UT WOS:A1991GD96700082 ER PT J AU CRESPI, VH COHEN, ML AF CRESPI, VH COHEN, ML TI ANHARMONIC PHONONS AND THE ANOMALOUS ISOTOPE EFFECT IN LA2-XSRXCUO4 SO PHYSICAL REVIEW B LA English DT Note AB A model for the variation of an interionic potential near the orthorhombic to low-temperature-tetragonal structural phase transition in La-Sr-Cu-O can explain variations both above and below 0.5 in the superconducting isotope-effect parameter-alpha. In particular, we posit a quadrupolar potential in which the four outer wells deepen as the phase transition is approached. This model can reproduce the experimentally observed variations in both T(c) and alpha. C1 UNIV CALIF BERKELEY LAWRENCE BERKELEY LAB,DIV MAT SCI,BERKELEY,CA 94720. RP CRESPI, VH (reprint author), UNIV CALIF BERKELEY,DEPT PHYS,BERKELEY,CA 94720, USA. OI Crespi, Vincent/0000-0003-3846-3193 NR 11 TC 26 Z9 26 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 SEP 1 PY 1991 VL 44 IS 9 BP 4712 EP 4715 DI 10.1103/PhysRevB.44.4712 PG 4 WC Physics, Condensed Matter SC Physics GA GD967 UT WOS:A1991GD96700089 ER PT J AU FORSTMANN, F GRASMARTI, A FERRELL, TL WARMACK, RJ MAMOLA, KC AF FORSTMANN, F GRASMARTI, A FERRELL, TL WARMACK, RJ MAMOLA, KC TI ENERGY-LOSS OF LOW-ENERGY ELECTRONS TO NONABRUPT METAL-SURFACES SO PHYSICAL REVIEW B LA English DT Article ID PLASMON EXCITATION; EDGE MODES; SILVER; BEAMS AB The interaction of a charged particle with a semi-infinite medium bounded by a flat surface is analyzed as a problem of metal optics. The reflection at the surface of the electromagnetic fields excited by the passing beam is investigated including retardation and spatial dispersion in the hydrodynamic approximation. The soft decay of the electron density at the metal-vacuum interface is modeled. Using measured values of the dielectric function, the calculations are found to agree with experimental results of electron-energy-loss distributions for Ag targets in interaction at a distance. Further predictions of the theoretical model are discussed. C1 FREE UNIV BERLIN,INST THEORET PHYS,W-1000 BERLIN 33,GERMANY. UNIV ALACANT,DEPT FIS APLICADA,E-03080 ALACANT,SPAIN. RP FORSTMANN, F (reprint author), OAK RIDGE NATL LAB,DIV HLTH & SAFETY RES,OAK RIDGE,TN 37831, USA. OI Warmack, Robert/0000-0001-8298-2420 NR 29 TC 4 Z9 4 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 SEP 1 PY 1991 VL 44 IS 10 BP 4884 EP 4891 DI 10.1103/PhysRevB.44.4884 PG 8 WC Physics, Condensed Matter SC Physics GA GD968 UT WOS:A1991GD96800014 ER PT J AU ASTA, M WOLVERTON, C DEFONTAINE, D DREYSSE, H AF ASTA, M WOLVERTON, C DEFONTAINE, D DREYSSE, H TI EFFECTIVE CLUSTER INTERACTIONS FROM CLUSTER-VARIATION FORMALISM .1. SO PHYSICAL REVIEW B LA English DT Article ID TRANSITION-METAL ALLOYS; GENERALIZED PERTURBATION-THEORY; CENTERED-CUBIC LATTICE; 2ND-NEIGHBOR INTERACTIONS; ORDERING ENERGIES; NEAREST-NEIGHBOR; BINARY-ALLOYS; MONTE-CARLO; FCC LATTICE; 1ST-NEIGHBOR AB States of (partial) order in binary-alloy systems are described by means of expansions in a complete set of orthogonal cluster functions. The expectation value of the energy of such systems can then be expressed as a bilinear form in multisite correlation variables and effective cluster interactions (ECI's), as originally proposed by Sanchez, Ducastelle, and Gratias [Physica A 128, 334 (1984)]. It is shown that ECI's are defined as interchange energies averaged over all atomic configurations with a fixed concentration or over all configurations and concentrations, depending on the orthogonal expansion considered. The former averaging process leads to concentration-dependent ECI's, the latter to concentration-independent ECI's. From their formal definitions, certain relations will be shown to hold between the interactions derived in the two averaging schemes in the thermodynamic limit. In particular, an interesting convergence criterion is established for the concentration-dependent ECI's. C1 UNIV CALIF BERKELEY LAWRENCE BERKELEY LAB,DIV MAT SCI,BERKELEY,CA 94720. UNIV CALIF BERKELEY,DEPT MAT SCI & MINERAL ENGN,BERKELEY,CA 94720. UNIV NANCY 1,PHYS SOLIDE LAB,F-54506 VANDOEUVRE NANCY,FRANCE. RP ASTA, M (reprint author), UNIV CALIF BERKELEY,DEPT PHYS,BERKELEY,CA 94720, USA. RI Wolverton, Christopher/B-7542-2009 NR 18 TC 86 Z9 86 U1 1 U2 14 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 SEP 1 PY 1991 VL 44 IS 10 BP 4907 EP 4913 DI 10.1103/PhysRevB.44.4907 PG 7 WC Physics, Condensed Matter SC Physics GA GD968 UT WOS:A1991GD96800016 ER PT J AU WOLVERTON, C ASTA, M DREYSSE, H DEFONTAINE, D AF WOLVERTON, C ASTA, M DREYSSE, H DEFONTAINE, D TI EFFECTIVE CLUSTER INTERACTIONS FROM CLUSTER-VARIATION FORMALISM .2. SO PHYSICAL REVIEW B LA English DT Article ID TRANSITION-METAL ALLOYS; GENERALIZED PERTURBATION-THEORY; EFFECTIVE-PAIR INTERACTIONS; CENTERED-CUBIC LATTICE; BINARY-ALLOYS; PHASE-DIAGRAM; 2ND-NEIGHBOR INTERACTIONS; NEIGHBOR INTERACTIONS; ORDERED STRUCTURES; NEAREST-NEIGHBOR AB Using the recently developed direct-configurational-averaging method, we have considered the expansion of formation energies of the random and ordered states in terms of effective cluster interactions (ECI's) for two model tight-binding binary-alloy systems. In particular, we have examined the rates of convergence of such expansions in two different averaging schemes. In the canonical scheme the ECI's depend on the concentration (c) of the alloy explicitly, while for grand-canonical averaging they do not. For a model system in which the ordering energies are highly asymmetric about c = 0. 5, we find that an expansion in canonical ECI's gives slightly better convergence. However, for the other system considered, both averaging schemes lead to similarly convergent expansions due to the symmetry of the system about c = 0.5. We have also verified numerically formal relations between the ECI's in the two averaging schemes. Such relations provide a useful convergence criterion of expansions in terms of ECT's. C1 UNIV CALIF BERKELEY LAWRENCE BERKELEY LAB,DIV MAT SCI,BERKELEY,CA 94720. UNIV NANCY 1,PHYS SOLIDE LAB,F-54506 VANDOEUVRE NANCY,FRANCE. UNIV CALIF BERKELEY,DEPT MAT SCI & MINERAL ENGN,BERKELEY,CA 94720. RP WOLVERTON, C (reprint author), UNIV CALIF BERKELEY,DEPT PHYS,BERKELEY,CA 94720, USA. RI Wolverton, Christopher/B-7542-2009 NR 54 TC 59 Z9 59 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 SEP 1 PY 1991 VL 44 IS 10 BP 4914 EP 4924 DI 10.1103/PhysRevB.44.4914 PG 11 WC Physics, Condensed Matter SC Physics GA GD968 UT WOS:A1991GD96800017 ER PT J AU CLOGSTON, AM MCDOWELL, HK AF CLOGSTON, AM MCDOWELL, HK TI NONLINEARLY COUPLED VIBRATIONAL-MODES AND SELF-TRAPPED STATES - QUANTUM LANGEVIN THEORY AND THE SINGLE-VIBRON-OSCILLATOR CASE SO PHYSICAL REVIEW B LA English DT Article ID MANY-BODY PROBLEMS; DIMENSIONAL MOLECULAR-CRYSTALS; CHEMICAL-DYNAMICS; EQUATION THEORY; DAVYDOV SOLITONS; POLARON FORMATION; EQUIVALENT CHAIN; LOCALIZATION; EXCITON; REPRESENTATION AB Very great difficulties face a full quantum-theoretical understanding of the problem posed by two nonlinearly interacting vibrational systems at finite temperature. Partial solutions have been obtained in some cases by oversimplification of the defining Hamiltonian or by limiting the Hilbert space of the solution. In this paper we -develop an approach to molecular-time-scale generalized-Langevin-equation theory which avoids these approximations. The theory is then applied to the problem of a single-vibron oscillator nonlinearly coupled to a linear chain of coupled molecules. The time correlation function chi (t) = Re<[c(t),c(0)]> is obtained and its valid time domain determined by comparison with an exact solution of the problem. The valid time domain is shown to be long enough to determine accurate values for the red shift and exponential decay of chi (t) for a wide range of values of parameters including temperature and strength of the nonlinear interaction. An unexpected result is that the exact solution exhibits a slow power-law decay at very low temperatures. RP CLOGSTON, AM (reprint author), UNIV CALIF LOS ALAMOS SCI LAB,CTR MAT SCI,MS K765,LOS ALAMOS,NM 87545, USA. NR 45 TC 10 Z9 10 U1 1 U2 2 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 0163-1829 J9 PHYS REV B JI Phys. Rev. B PD SEP 1 PY 1991 VL 44 IS 10 BP 4978 EP 4999 DI 10.1103/PhysRevB.44.4978 PG 22 WC Physics, Condensed Matter SC Physics GA GD968 UT WOS:A1991GD96800023 ER PT J AU FRELTOFT, T BUTTREY, DJ AEPPLI, G VAKNIN, D SHIRANE, G AF FRELTOFT, T BUTTREY, DJ AEPPLI, G VAKNIN, D SHIRANE, G TI MAGNETIC CORRELATIONS AND THEIR DEPENDENCE ON EXCESS OXYGEN IN LA2NIO4+DELTA SO PHYSICAL REVIEW B LA English DT Article ID TRANSITION-METAL OXIDE; SINGLE-CRYSTAL; PHASE-TRANSITION; DOPED LA2CUO4; SPIN; ANTIFERROMAGNETISM; SUPERCONDUCTIVITY; SEMICONDUCTOR; STOICHIOMETRY; LA2-XSRXCUO4 AB We report results of elastic- and inelastic-neutron-scattering studies of three single crystals of the layered perovskite La2NiO4+delta, with delta = 0.00, 0.067, and 0.077, as well as neutron powder diffraction on a material with an oxygen excess delta almost-equal-to 0.065. The magnetic correlations are highly sensitive to the oxygen content, and three-dimensional antiferromagnetic order sets in at T(N) greater-than-or-equal-to 300 K, and T(N) = 68, and 48 K for the single crystals, respectively, and at T(N) = 74 K for the powder sample. The crystal with delta = 0.067 was studied in detail to characterize the tetragonal to orthorhombic (T(s) = 232-240 K) and antiferromagnetic (T(N) = 68 K) transitions. The order parameter eta(T) for the orthorhombic distortion shows a power-law dependence on temperature with the exponent beta = 0.21 and hysteresis, suggesting that this transition is less than second order. Two-dimensional critical scattering is observed around the antiferromagnetic phase transition. The magnetic excitation spectra in the three-dimensional ordered state are characterized by small anisotropy gaps between approximately 0 and 3 meV, and large effective in-plane spin-wave velocities, which decrease with increasing delta. For delta = 0. 077, c almost-equal-to 130 meV angstrom; and for delta = 0.00, c greater-than-or-equal-to 300 meV angstrom. C1 UNIV DELAWARE,DEPT CHEM ENGN,COLBURN LAB,NEWARK,DE 19716. AT&T BELL LABS,MURRAY HILL,NJ 07974. RISO NATL LAB,DEPT PHYS,DK-4000 ROSKILDE,DENMARK. BROOKHAVEN NATL LAB,UPTON,NY 11973. RP FRELTOFT, T (reprint author), NKT,CORP RES & DEV,DK-2605 BRONDBY,DENMARK. RI Vaknin, David/B-3302-2009 OI Vaknin, David/0000-0002-0899-9248 NR 51 TC 42 Z9 42 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 SEP 1 PY 1991 VL 44 IS 10 BP 5046 EP 5056 DI 10.1103/PhysRevB.44.5046 PG 11 WC Physics, Condensed Matter SC Physics GA GD968 UT WOS:A1991GD96800031 ER PT J AU TRANQUADA, JM HEALD, SM KUNNMANN, W MOODENBAUGH, AR QIU, SL XU, YW DAVIES, PK AF TRANQUADA, JM HEALD, SM KUNNMANN, W MOODENBAUGH, AR QIU, SL XU, YW DAVIES, PK TI COMPARATIVE-STUDY OF CU K-EDGE X-RAY-ABSORPTION AND CU 2P X-RAY PHOTOELECTRON-SPECTRA IN COPPER-OXIDE COMPOUNDS SO PHYSICAL REVIEW B LA English DT Article ID HIGH-TC SUPERCONDUCTORS; HIGH-TEMPERATURE SUPERCONDUCTORS; SHAKE-DOWN PHENOMENA; ELECTRONIC-STRUCTURE; NEAR-EDGE; CRYSTAL-STRUCTURE; SINGLE-CRYSTAL; FINE-STRUCTURE; O SYSTEM; SPECTROSCOPY AB We have measured polarization-dependent x-ray-absorption spectra (XAS) at the Cu K edge in magnetically-aligned powder samples of La2CuO4, Nd2CuO4, Bi2CuO4, Ca0.85Sr0.15CuO2, and SrCuO2, all of which contain Cu coordinated by four coplanar O nearest neighbors. We have also measured Cu 2p3/2 x-ray photoelectron spectra (XPS) for all except the last compound. The measurements have been analyzed in terms of unrestricted Hartree-Fock calculations for CuO6(10-) and CuO12(22-) clusters, with energies and Coulomb parameters, including interactions with the core hole, for the Cu 3d(x2-y2), 4s, and 4p orbitals determined in an ab initio fashion. It is well known that the intensity ratio of the two XPS peaks is sensitive to the degree of hybridization between Cu 3d(x2-y2) and O 2p-sigma orbitals in the ground state. We show both by empirical correlations and model calculations that the relative shift of the continuum absorption threshold for epsilon parallel-to z (where z is perpendicular to the plane of the CuO4 units) and the shift of the main (3d10L) XPS peak are also useful measures of the covalency. The Cu 4p(z)-like quasibound state observed in XAS is sensitive as well to 4p(z)-O2p hybridization. In the cluster calculations, good agreement with the experimental features is obtained with use of a single adjustable parameter, the energy of the O 2p-sigma level (measured relative to Cu 3d(x2-y2)). We show that this energy varies linearly with the difference in Madelung energies for the O and Cu sites. C1 UNIV PENN,RES STRUCT MATTER LAB,PHILADELPHIA,PA 19104. RP TRANQUADA, JM (reprint author), BROOKHAVEN NATL LAB,UPTON,NY 11973, USA. RI Tranquada, John/A-9832-2009; OI Tranquada, John/0000-0003-4984-8857; Moodenbaugh, Arnold/0000-0002-3415-6762 NR 56 TC 42 Z9 42 U1 1 U2 13 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 SEP 1 PY 1991 VL 44 IS 10 BP 5176 EP 5189 DI 10.1103/PhysRevB.44.5176 PG 14 WC Physics, Condensed Matter SC Physics GA GD968 UT WOS:A1991GD96800047 ER PT J AU GYORFFY, BL STAUNTON, JB STOCKS, GM AF GYORFFY, BL STAUNTON, JB STOCKS, GM TI PAIRING, CONDENSATION, AND SUPERCONDUCTIVITY DESCRIBED BY A HUBBARD-MODEL WITH AN ATTRACTIVE INTERACTION SO PHYSICAL REVIEW B LA English DT Article ID AMORPHOUS-SEMICONDUCTORS; ELECTRONIC-STRUCTURE; BOSE CONDENSATION; 2 DIMENSIONS; MAGNETISM; CRYSTALS; METALS; IRON; SUSCEPTIBILITY; APPROXIMATION AB We have developed a method for studying superconductivity in the negative-U Hubbard model. It is based on the Hubbard-alloy-analogy approximation applied to the Gor'kov equation for the model. We find that, unlike the case of the BCS solution, the formation of pairs and their condensation into a super-conducting ground state take place at two different temperatures. We calculate the condensation temperature T(c) for all U and discuss the nature of the normal state which, for large enough U, features a macroscopically large number of pairs. Briefly, we argue that the model has relevance for high-temperature superconductors. C1 UNIV WARWICK,DEPT PHYS,COVENTRY CV4 7AL,W MIDLANDS,ENGLAND. OAK RIDGE NATL LAB,OAK RIDGE,TN 37831. RP GYORFFY, BL (reprint author), UNIV BRISTOL,HH WILLS PHYS LAB,TYNDALL AVE,BRISTOL BS8 1TL,AVON,ENGLAND. RI Stocks, George Malcollm/Q-1251-2016 OI Stocks, George Malcollm/0000-0002-9013-260X NR 45 TC 47 Z9 47 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 SEP 1 PY 1991 VL 44 IS 10 BP 5190 EP 5208 DI 10.1103/PhysRevB.44.5190 PG 19 WC Physics, Condensed Matter SC Physics GA GD968 UT WOS:A1991GD96800048 ER PT J AU COFFEY, MW HAO, ZD AF COFFEY, MW HAO, ZD TI DIPOLAR ELECTRIC-FIELD INDUCED BY A VORTEX MOVING IN AN ANISOTROPIC SUPERCONDUCTOR SO PHYSICAL REVIEW B LA English DT Article AB The dipolar electric field induced by an isolated vortex aligned along a principal axis and moving at constant velocity in an anisotropic type-II superconductor is investigated. It is shown that the standard dipolar-field case can be extended by the inclusion of a mass-anisotropy parameter-beta. It is shown that the streamlines of the electric field can be easily calculated analytically. In addition, an inertial mass tensor per unit length of vortex is found. C1 IOWA STATE UNIV SCI & TECHNOL, DEPT PHYS & ASTRON, AMES, IA 50011 USA. RP COFFEY, MW (reprint author), IOWA STATE UNIV SCI & TECHNOL, AMES LAB, AMES, IA 50011 USA. NR 24 TC 23 Z9 23 U1 0 U2 0 PU AMER PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 1098-0121 EI 1550-235X J9 PHYS REV B JI Phys. Rev. B PD SEP 1 PY 1991 VL 44 IS 10 BP 5230 EP 5234 DI 10.1103/PhysRevB.44.5230 PG 5 WC Physics, Condensed Matter SC Physics GA GD968 UT WOS:A1991GD96800051 ER PT J AU KORNELSEN, K ELDRIDGE, JE WANG, HH WILLIAMS, JM AF KORNELSEN, K ELDRIDGE, JE WANG, HH WILLIAMS, JM TI INFRARED OPTICAL-PROPERTIES OF THE 10-K ORGANIC SUPERCONDUCTOR (BEDT-TTF)2[CU(NCS)2] [WHERE (BEDT-TTF) IS BIS(ETHYLENEDITHIO)TETRATHIAFULVALENE] SO PHYSICAL REVIEW B LA English DT Article ID AMBIENT-PRESSURE; FERMI-SURFACE; TC; (BEDT-TTF)2CU(NCS)2; TEMPERATURE; KAPPA-(BEDT-TTF)2; KAPPA-(BEDT-TTF)2CU(NCS)2; SALTS; GAP; TETRAMETHYLTETRASELENAFULVALENE AB Low-temperature polarized bolometric absorption measurements have been performed on the T(c) = 10.4 K organic superconductor kappa-(BEDT-TTF)2[Cu(NCS)2], where BEDT-TTF is bis(ethylenedithio)tetrathiafulvalene. The ratio of the absorption at 5.3 K to that at 10.5 K from 10 to 40 cm-1 showed no evidence of a conventional BCS gap. Polarized-reflectivity measurements at temperatures between 10 and 295 K are also reported for both the protonated and deuterated compounds, between 200 and 8000 cm-1. The 10-K spectra were calibrated by a technique of simultaneously measuring the reflectivity R and the absorptance, 1 - R. The resulting conductivities display vibrational features superimposed on an electronic background. This background shifts from mid-infrared interband transitions, when the dc conductivity is low, to far-infrared intraband transitions as the dc conductivity increases. The vibrations have been assigned to a mixture of normally inactive a(g) modes and normally active b2u Modes of the BEDT-tTF molecule. A few of both types couple strongly to the charge carriers. One in particular has a very temperature-dependent frequency due to the changing intensity of the mid-infrared band. C1 ARGONNE NATL LAB,DIV MAT SCI,ARGONNE,IL 60439. ARGONNE NATL LAB,DIV CHEM,ARGONNE,IL 60439. RP KORNELSEN, K (reprint author), UNIV BRITISH COLUMBIA,DEPT PHYS,VANCOUVER V6T 1Z1,BC,CANADA. NR 45 TC 69 Z9 69 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 SEP 1 PY 1991 VL 44 IS 10 BP 5235 EP 5245 DI 10.1103/PhysRevB.44.5235 PG 11 WC Physics, Condensed Matter SC Physics GA GD968 UT WOS:A1991GD96800052 ER PT J AU PARKER, ID ZETTL, A AF PARKER, ID ZETTL, A TI SPIN-DENSITY-WAVE PINNING IN CHROMIUM SO PHYSICAL REVIEW B LA English DT Note ID OHMIC ELECTRICAL TRANSPORT; CONDUCTIVITY; IMPURITIES; CHARGE; STATE; PHASE AB Attempts were made to depin the three-dimensional incommensurate spin-density wave (SDW) found in chromium below 311 K. Pulsed electric fields were applied to high-purity single crystals at room temperature and 250 K, and in various orientations with respect to the crystal lattice. No electrical-conductivity nonlinearities were observed for applied fields as high as 100 V/cm. We contrast this behavior with the low depinning fields found for the SDW's in some low-dimensional organic conductors. C1 UNIV CALIF BERKELEY LAWRENCE BERKELEY LAB,DIV MAT SCI,BERKELEY,CA 94720. RP PARKER, ID (reprint author), UNIV CALIF BERKELEY,DEPT PHYS,BERKELEY,CA 94720, USA. RI Zettl, Alex/O-4925-2016 OI Zettl, Alex/0000-0001-6330-136X NR 13 TC 1 Z9 1 U1 0 U2 0 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 0163-1829 J9 PHYS REV B JI Phys. Rev. B PD SEP 1 PY 1991 VL 44 IS 10 BP 5313 EP 5315 DI 10.1103/PhysRevB.44.5313 PG 3 WC Physics, Condensed Matter SC Physics GA GD968 UT WOS:A1991GD96800065 ER PT J AU JARRELL, M GUBERNATIS, JE SILVER, RN AF JARRELL, M GUBERNATIS, JE SILVER, RN TI DYNAMIC SUSCEPTIBILITY OF THE ANDERSON MODEL - A QUANTUM MONTE-CARLO STUDY SO PHYSICAL REVIEW B LA English DT Note ID EXPANSION; ALLOYS; HEAT AB Using a highly accurate method of analytic continuation, we calculated the dynamic susceptibility and NMR relaxation rate 1/T1 of magnetic (Anderson or Kondo) impurities over the entire range T << T-kappa to T >> T-kappa. We find that the susceptibility and NMR relaxation rate are universal functions when properly scaled and that the NMR relaxation rate is directly proportional to the universal Kondo resistivity. C1 UNIV CALIF LOS ALAMOS SCI LAB,DIV THEORET,LOS ALAMOS,NM 87545. UNIV CALIF LOS ALAMOS SCI LAB,CTR NEUTRON SCATTERING,THEORET DIV & MANUEL LUJAN JR,LOS ALAMOS,NM 87545. RP JARRELL, M (reprint author), UNIV CINCINNATI,DEPT PHYS,CINCINNATI,OH 45221, USA. NR 21 TC 19 Z9 19 U1 1 U2 2 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 0163-1829 J9 PHYS REV B JI Phys. Rev. B PD SEP 1 PY 1991 VL 44 IS 10 BP 5347 EP 5350 DI 10.1103/PhysRevB.44.5347 PG 4 WC Physics, Condensed Matter SC Physics GA GD968 UT WOS:A1991GD96800075 ER PT J AU PHAM, T LEE, MW DREW, HD WELP, U FANG, Y AF PHAM, T LEE, MW DREW, HD WELP, U FANG, Y TI FAR-INFRARED ABSORPTIVITY OF SINGLE-DOMAIN YBA2CU3O7 SO PHYSICAL REVIEW B LA English DT Note ID ELECTRONIC RAMAN-SCATTERING; A-B ANISOTROPY; UNTWINNED YBA2CU3O7-DELTA; CRYSTALS; GAP; CONDUCTIVITY AB Measurements on detwinned single crystals for radiation polarized along the a axis at 2 K give an approximately 0.5% absorptivity for frequencies between congruent-to 100 and 400 cm-1 and a strong onset at approximately equal to 450 cm-1. Anisotropy is observed between the a- and b-axis polarization absorptivities. The conductivity function deduced from a Kramers-Kronig analysis of the a-axis data shows low-frequency absorption bands of electronic strength. C1 LAB PHYS SCI,COLLEGE PK,MD 20740. ARGONNE NATL LAB,DIV MAT SCI,ARGONNE,IL 60439. NATL CHUNG HSING UNIV,DEPT PHYS,TAICHUNG,TAIWAN. RP PHAM, T (reprint author), UNIV MARYLAND,CTR SUPERCONDUCTIV RES,DEPT PHYS,COLLEGE PK,MD 20742, USA. NR 32 TC 46 Z9 46 U1 0 U2 0 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 0163-1829 J9 PHYS REV B JI Phys. Rev. B PD SEP 1 PY 1991 VL 44 IS 10 BP 5377 EP 5380 DI 10.1103/PhysRevB.44.5377 PG 4 WC Physics, Condensed Matter SC Physics GA GD968 UT WOS:A1991GD96800083 ER PT J AU WARBURTON, EK AF WARBURTON, EK TI IN-MEDIUM AND CORE-POLARIZATION EFFECTS IN K-50(0-)BETA- -] CA-50(0+) SO PHYSICAL REVIEW C LA English DT Article ID 1ST-FORBIDDEN BETA-DECAY; SHELL-MODEL; SPIN-DIPOLE; EXCHANGE CORRECTION; NUCLEI; TRANSITIONS; ISOSPIN AB A shell-model calculation in the model space of the (0d, 1s) and (0f, 1p) major shells is made for the first-forbidden beta- transition 50K(0-) --> 50Ca(0+). Various truncation schemes were evaluated and the one adopted was to allow at most two neutrons in the nu-0f5/2 orbit. An evaluation of the "final-state" core-polarization effects is made perturbatively for the two rank-zero matrix elements which contribute to DELTA-J = 0 first-forbidden beta decays. The core-polarization effect is also applicable to DELTA-J = 0 spin-dipole excitations in the A almost-equal-to 40 region. Comparison of the shell-model (impulse approximation) prediction to experiment indicates the need for an appreciable in-medium contribution to the timelike component of the weak axial current. The enhancement of 52% found in this comparison is in good agreement with the general trend of predictions for one-pion exchange processes in DELTA-J = 0 first-forbidden decays in A = 16 to 96 nuclei. RP WARBURTON, EK (reprint author), BROOKHAVEN NATL LAB,UPTON,NY 11973, USA. NR 37 TC 13 Z9 13 U1 0 U2 0 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 0556-2813 J9 PHYS REV C JI Phys. Rev. C PD SEP PY 1991 VL 44 IS 3 BP 1024 EP 1029 DI 10.1103/PhysRevC.44.1024 PG 6 WC Physics, Nuclear SC Physics GA GE583 UT WOS:A1991GE58300013 ER PT J AU LASSILA, KE SUKHATME, UP HARINDRANATH, A VARY, JP AF LASSILA, KE SUKHATME, UP HARINDRANATH, A VARY, JP TI DILEPTON PRODUCTION BY PROTONS ON NUCLEI AND THE PARTONIC ORIGIN OF DEPLETION AT SMALL MOMENTUM FRACTION SO PHYSICAL REVIEW C LA English DT Article ID INELASTIC LEPTON SCATTERING; QUARK-CLUSTER-MODEL; ELECTRON-SCATTERING; MUON SCATTERING; PAIR PRODUCTION; IRON TARGETS; SMALL VALUES; DEUTERIUM; DEPENDENCE; DISTRIBUTIONS AB We discuss and extend our previous predictions of dilepton depletion at small target parton momentum fraction in proton-nucleus collisons. These predictions were based on an analysis of the partonic origin of the European Muon Collaboration effect in deep-inelastic scattering (DIS) in a treatment of nuclei allowing multiquark clusters to be formed. With this input, we calculate the ratio of dimuons produced on nuclei to those produced on free nucleons. We obtain excellent agreement with data from a recent experiment, emphasizing that all input information came from our previous DIS analysis. Our calculations predict that beyond the range of presently measured data, there will be considerable dependence on the momentum carried by the annihilating parton in the incident proton. C1 IOWA STATE UNIV SCI & TECHNOL,DEPT PHYS,AMES,IA 50011. IOWA STATE UNIV SCI & TECHNOL,AMES LAB,AMES,IA 50011. OHIO STATE UNIV,DEPT PHYS,COLUMBUS,OH 43210. RP LASSILA, KE (reprint author), ARGONNE NATL LAB,DEPT HIGH ENERGY PHYS,ARGONNE,IL 60439, USA. NR 39 TC 13 Z9 13 U1 0 U2 0 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 0556-2813 J9 PHYS REV C JI Phys. Rev. C PD SEP PY 1991 VL 44 IS 3 BP 1188 EP 1194 DI 10.1103/PhysRevC.44.1188 PG 7 WC Physics, Nuclear SC Physics GA GE583 UT WOS:A1991GE58300032 ER PT J AU AHMAD, I CARPENTER, MP CHASMAN, RR JANSSENS, RVF KHOO, TL AF AHMAD, I CARPENTER, MP CHASMAN, RR JANSSENS, RVF KHOO, TL TI ROTATIONAL BANDS WITH IDENTICAL TRANSITION ENERGIES IN ACTINIDE NUCLEI SO PHYSICAL REVIEW C LA English DT Note ID HIGH-SPIN STATES; SUPERDEFORMED BANDS; SYMMETRY; REGION; CM-248; E2 AB We point out the existence of ground-state rotational bands with identical transition energies (up to spin 8h) in Pu-240, Cm-244, Cm-246, and Cf-250. The corresponding transitions in the ground-state bands of U-236 and U-238 have identical energies (within approximately 2 keV) up to spin 24h. These features are very similar to those recently observed for superdeformed bands in the mass-150 and mass-190 regions and suggest that the phenomenon of identical bands is not restricted to superdeformed bands. RP AHMAD, I (reprint author), ARGONNE NATL LAB,ARGONNE,IL 60439, USA. RI Carpenter, Michael/E-4287-2015 OI Carpenter, Michael/0000-0002-3237-5734 NR 30 TC 58 Z9 59 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 SEP PY 1991 VL 44 IS 3 BP 1204 EP 1207 DI 10.1103/PhysRevC.44.1204 PG 4 WC Physics, Nuclear SC Physics GA GE583 UT WOS:A1991GE58300034 ER PT J AU BINGHAM, CR KASSIM, MB ZHANG, M AKOVALI, YA TOTH, KS HAMILTON, WD CARTER, HK KORMICKI, J VONSCHWARZENBERG, J JARRIO, MM AF BINGHAM, CR KASSIM, MB ZHANG, M AKOVALI, YA TOTH, KS HAMILTON, WD CARTER, HK KORMICKI, J VONSCHWARZENBERG, J JARRIO, MM TI IDENTIFICATION OF PT-185 A-ACTIVITY AND STUDY OF AU-185 A-DECAY SO PHYSICAL REVIEW C LA English DT Note ID IR-181; SPIN AB The alpha-decay of Pt-185 has been observed for the first time and alpha-decay branching ratios have been determined for 185Au and 185Pt by use of an on-line isotope separator. A single alpha-decay line at 4444 +/- 10 keV has been shown to result from the decay of 185Pt. The current data are insufficient to determine which of the long-lived states of 185Pt decays via alpha-emission. The alpha branching deduced from the alpha, gamma, and x-ray data taken simultaneously is [(1.0 +/- 0.4) x 10(-3)]% if the alpha comes from the 33.0-min isomer, or [(5.0 +/- 2.0) x 10(-3)]% if the alpha comes from the 70.9-min ground state of 185Pt. In either case the transition is an unhindered one. Two lines at 5069 +/- 10 and 4826 +/- 10 keV, with relative intensities of 100 and 0.16, are attributed to the alpha-decay of 185Au and the deduced alpha-branching is (0.7 +/- 0.1)%. The hindrance factors are 0.4 for the 5069-keV, and 8.8 for the 4826-keV transitions. C1 OAK RIDGE NATL LAB,OAK RIDGE,TN 37830. JOINT INST HEAVY ION RES,OAK RIDGE,TN 37831. VANDERBILT UNIV,NASHVILLE,TN 37325. GEORGIA INST TECHNOL,ATLANTA,GA 30332. OAK RIDGE ASSOCIATED UNIV,OAK RIDGE,TN 37831. RP BINGHAM, CR (reprint author), UNIV TENNESSEE,KNOXVILLE,TN 37996, USA. NR 13 TC 9 Z9 9 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 SEP PY 1991 VL 44 IS 3 BP 1208 EP 1211 DI 10.1103/PhysRevC.44.1208 PG 4 WC Physics, Nuclear SC Physics GA GE583 UT WOS:A1991GE58300035 ER PT J AU FRIEDLANDER, EM HE, XC SHIH, CC WEINER, RM AF FRIEDLANDER, EM HE, XC SHIH, CC WEINER, RM TI MULTIPLICITY DISTRIBUTIONS, TRANSVERSE-MOMENTA, AND NONSTATIONARY EFFECTS SO PHYSICAL REVIEW D LA English DT Article ID ENERGY MULTIHADRON DISTRIBUTIONS; QUANTUM-STATISTICAL APPROACH; PP COLLISIONS; RAPIDITY DISTRIBUTIONS; COUNTING STATISTICS; 250 GEV/C; DEPENDENCE; INTERMITTENCY; RANGE; FLUCTUATIONS AB The application of the quantum statistical formalism to multiplicity distributions has been generalized to include corrections for "nonstationarity" in rapidity as well as the transverse-momentum dependence. The identical-particle data available so far can be explained in this formalism with a quite broad range of parameters of chaoticity and correlation lengths. C1 UNIV TENNESSEE,DEPT PHYS,KNOXVILLE,TN 37916. UNIV MARBURG,DEPT PHYS,W-3550 MARBURG,GERMANY. RP FRIEDLANDER, EM (reprint author), UNIV CALIF BERKELEY LAWRENCE BERKELEY LAB,DIV NUCL SCI,BERKELEY,CA 94720, USA. NR 33 TC 1 Z9 1 U1 0 U2 0 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 0556-2821 J9 PHYS REV D JI Phys. Rev. D PD SEP 1 PY 1991 VL 44 IS 5 BP 1396 EP 1402 DI 10.1103/PhysRevD.44.1396 PG 7 WC Astronomy & Astrophysics; Physics, Particles & Fields SC Astronomy & Astrophysics; Physics GA GD241 UT WOS:A1991GD24100006 ER PT J AU KAUFFMAN, RP AF KAUFFMAN, RP TI HIGGS-BOSON PT IN GLUON FUSION SO PHYSICAL REVIEW D LA English DT Article ID TRANSVERSE-MOMENTUM DISTRIBUTION; TO-BACK JETS AB The transverse-momentum distribution of Higgs bosons produced via gluon fusion is calculated. The calculation matches multiple-gluon resummation at small P(T) with the lowest-order calculation at high p(T). The full dependence on the top-quark mass is retained and the shape of the distribution at small P(T) is shown to be independent of m(t). RP KAUFFMAN, RP (reprint author), ARGONNE NATL LAB,DIV HIGH ENERGY PHYS,ARGONNE,IL 60439, USA. NR 10 TC 75 Z9 75 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 SEP 1 PY 1991 VL 44 IS 5 BP 1415 EP 1425 DI 10.1103/PhysRevD.44.1415 PG 11 WC Astronomy & Astrophysics; Physics, Particles & Fields SC Astronomy & Astrophysics; Physics GA GD241 UT WOS:A1991GD24100008 ER PT J AU BARGER, V CHEUNG, K HAN, T OHNEMUS, J ZEPPENFELD, D AF BARGER, V CHEUNG, K HAN, T OHNEMUS, J ZEPPENFELD, D TI COMPARATIVE-STUDY OF THE BENEFITS OF FORWARD JET TAGGING IN HEAVY-HIGGS-BOSON PRODUCTION AT THE SUPERCONDUCTING SUPER COLLIDER SO PHYSICAL REVIEW D LA English DT Article ID PAIR PRODUCTION; TRANSVERSE-MOMENTUM; SYMMETRY-BREAKING; LEPTON PRODUCTION; SCATTERING; SUPERCOLLIDERS; AMPLITUDES; E+E; PP AB The event rate for production of a Higgs boson of mass approximately 1 TeV with decay H --> ZZ --> 4 charged leptons is of order 25 events per year at standard Superconducting Super Collider luminosity and the QCD background is of comparable size. By tagging a single forward jet of energy E(j) > 1 TeV and rapidity 2 < (eta-j) < 5 from the qq --> qqZZ process, the QCD background can be essentially eliminated, with about 10 Higgs-boson signal events per year remaining, which amounts to 70% of the qq --> qqZZ signal rate. The experimental separation of the vector-boson scattering subprocess is thereby possible. C1 FERMI NATL ACCELERATOR LAB,BATAVIA,IL 60510. FLORIDA STATE UNIV,DEPT PHYS,TALLAHASSEE,FL 32306. RP BARGER, V (reprint author), UNIV WISCONSIN,DEPT PHYS,MADISON,WI 53706, USA. RI Cheung, Kingman/A-8380-2008 OI Cheung, Kingman/0000-0003-2176-4053 NR 36 TC 63 Z9 63 U1 0 U2 0 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 0556-2821 J9 PHYS REV D JI Phys. Rev. D PD SEP 1 PY 1991 VL 44 IS 5 BP 1426 EP 1437 DI 10.1103/PhysRevD.44.1426 PG 12 WC Astronomy & Astrophysics; Physics, Particles & Fields SC Astronomy & Astrophysics; Physics GA GD241 UT WOS:A1991GD24100009 ER PT J AU LIPKIN, HJ NIR, Y QUINN, HR SNYDER, AE AF LIPKIN, HJ NIR, Y QUINN, HR SNYDER, AE TI PENGUIN TRAPPING WITH ISOSPIN ANALYSIS AND CP ASYMMETRIES IN B-DECAYS SO PHYSICAL REVIEW D LA English DT Article ID VIOLATION AB Isospin relations are used to eliminate hadronic uncertainties in various CP asymmetries in B0 decays. In addition to the simple triangle relations for the pi-pi-mode, we study quadrilateral relations for K-pi and pentagon relations for rho-pi. A combined angular and isospin analysis is required for rho-rho. These methods are useful also for three-body decays such as K-pi-pi. The magnitude of the penguin amplitude can be extracted in various modes. The theoretical principles behind this analysis can be experimentally tested through sum rules for decay rates prior to the measurement of CP asymmetries. C1 STANFORD UNIV,STANFORD LINEAR ACCELERATOR CTR,STANFORD,CA 94305. RP LIPKIN, HJ (reprint author), WEIZMANN INST SCI,DEPT PHYS,IL-76100 REHOVOT,ISRAEL. NR 11 TC 140 Z9 140 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 SEP 1 PY 1991 VL 44 IS 5 BP 1454 EP 1460 DI 10.1103/PhysRevD.44.1454 PG 7 WC Astronomy & Astrophysics; Physics, Particles & Fields SC Astronomy & Astrophysics; Physics GA GD241 UT WOS:A1991GD24100012 ER PT J AU EILAM, G HEWETT, JL SONI, A AF EILAM, G HEWETT, JL SONI, A TI RARE DECAYS OF THE TOP QUARK IN THE STANDARD AND 2-HIGGS-DOUBLET MODELS SO PHYSICAL REVIEW D LA English DT Article ID CHANGING NEUTRAL CURRENTS; HIGGS-BOSON TRANSITIONS; RADIATIVE-B-DECAYS; ELECTROMAGNETIC VERTEX; 4 GENERATIONS; HEAVY QUARKS; CP-VIOLATION; MESON DECAY; MASSES; SECTOR AB The decays t --> cV, where V = gamma, g, or Z, and t --> cH are calculated, keeping all masses, in the standard model (SM) for all possible values of the top-quark mass that are consistent with present data. We find that the branching fractions for these processes are small, the largest being B(t --> cH) approximately 10(-7) and B(t --> cg) approximately 10(-10). Our calculations are then extended to include the possible contributions of charged Higgs bosons to the transitions t --> cV in the context of general two-Higgs-doublet models. These new contributions can enhance the SM branching fractions by as much as 3-4 orders of magnitude, e.g., B(t --> cg) approximately 10(-7)-10(-6), for various values of the parameters. General expressions for flavor-changing neutral-current decays of heavy quarks including all masses and momenta, in the SM and in the two-Higgs-doublet models, are also given. C1 UNIV WISCONSIN,DEPT PHYS,MADISON,WI 53706. BROOKHAVEN NATL LAB,DEPT PHYS,UPTON,NY 11973. RP EILAM, G (reprint author), TECHNION ISRAEL INST TECHNOL,DEPT PHYS,IL-32000 HAIFA,ISRAEL. NR 66 TC 252 Z9 254 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 SEP 1 PY 1991 VL 44 IS 5 BP 1473 EP 1484 DI 10.1103/PhysRevD.44.1473 PG 12 WC Astronomy & Astrophysics; Physics, Particles & Fields SC Astronomy & Astrophysics; Physics GA GD241 UT WOS:A1991GD24100014 ER PT J AU CARLSON, ED HALL, LJ SARID, U BURTON, JW AF CARLSON, ED HALL, LJ SARID, U BURTON, JW TI CORNERING COLOR SU(5) SO PHYSICAL REVIEW D LA English DT Article ID PHASE-TRANSITION; GAUGE-THEORIES; LATTICE; RENORMALIZATION; GLUEBALL; BEHAVIOR; SU(2); MASS; QCD AB Planned collider experiments will decisively test the color SU(5) model of Foot and Hernandez, in which an extended QCD group is broken at the TeV scale. Constraints from cosmology and from neutral-kaon mixing imply that exotic charge-1/2 fermions of this model cannot all be given masses above about 1 TeV. These "quirks" carry a new strong confining force, from the surviving unbroken gauge symmetry. Searches for the leptonic decay products of quirkonium at CERN LEP II will probe quirk masses up to near the beam energy, while searches at planned hadron colliders will be sensitive to quirk masses all the way up to the TeV upper bound. C1 UNIV CALIF BERKELEY,DEPT PHYS,BERKELEY,CA 94720. UNIV CALIF BERKELEY LAWRENCE BERKELEY LAB,BERKELEY,CA 94720. WEIZMANN INST SCI,DEPT NUCL PHYS,IL-76100 REHOVOT,ISRAEL. RP CARLSON, ED (reprint author), HARVARD UNIV,LYMAN LAB PHYS,CAMBRIDGE,MA 02138, USA. NR 21 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 0556-2821 J9 PHYS REV D JI Phys. Rev. D PD SEP 1 PY 1991 VL 44 IS 5 BP 1555 EP 1568 DI 10.1103/PhysRevD.44.1555 PG 14 WC Astronomy & Astrophysics; Physics, Particles & Fields SC Astronomy & Astrophysics; Physics GA GD241 UT WOS:A1991GD24100022 ER PT J AU MINTY, MG ELLISON, TJP GOODWIN, JE LEE, SY PANCELLA, PV RINCKEL, T ROSS, MA SPERISEN, F STEPHENSON, EJ VONPRZEWOSKI, B BAIOD, R DERBENEV, YS KRISCH, AD PHELPS, RA ROSER, T VANGUILDER, BS VUARIDEL, B COURANT, ED RATNER, LG AF MINTY, MG ELLISON, TJP GOODWIN, JE LEE, SY PANCELLA, PV RINCKEL, T ROSS, MA SPERISEN, F STEPHENSON, EJ VONPRZEWOSKI, B BAIOD, R DERBENEV, YS KRISCH, AD PHELPS, RA ROSER, T VANGUILDER, BS VUARIDEL, B COURANT, ED RATNER, LG TI ENERGY SHIFT OF A DEPOLARIZING RESONANCE DUE TO A TYPE-3 SIBERIAN SNAKE SO PHYSICAL REVIEW D LA English DT Note ID ACCELERATION AB We recently studied the proton beam polarization in the Indiana University Cyclotron Facility Cooler Ring at five energies. We found that the G-gamma = 2 imperfection depolarizing resonance occurred about 1.9 MeV below the expected resonance energy of 108.4 MeV. This energy shift could be due to a shift of about +0.0036 in the spin tune v(s), which is the number of spin rotations in each turn around the ring. We then demonstrated that this spin tune shift is consistent with the Cooler Ring containing a partial type-3 Siberian snake, which is apparently caused by the magnets that confine the electron and proton beams in the cooling region. C1 UNIV MICHIGAN,RANDALL LAB PHYS,ANN ARBOR,MI 48109. BROOKHAVEN NATL LAB,UPTON,NY 11973. RP MINTY, MG (reprint author), INDIANA UNIV,CYCLOTRON FACIL,BLOOMINGTON,IN 47405, USA. NR 13 TC 21 Z9 21 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 SEP 1 PY 1991 VL 44 IS 5 BP R1361 EP R1365 PG 5 WC Astronomy & Astrophysics; Physics, Particles & Fields SC Astronomy & Astrophysics; Physics GA GD241 UT WOS:A1991GD24100001 ER PT J AU CHENG, CZ AF CHENG, CZ TI ALPHA-PARTICLE DESTABILIZATION OF THE TOROIDICITY-INDUCED ALFVEN EIGENMODES SO PHYSICS OF FLUIDS B-PLASMA PHYSICS LA English DT Article ID AXISYMMETRIC TOROIDAL PLASMAS; MAGNETOHYDRODYNAMIC MODES; IGNITED TOKAMAK; EXCITATION; STABILITY; WAVES AB The high-frequency, low mode number toroidicity-induced Alfven eigenmodes (TAE) [Phys. Fluids 29, 3695 (1986) ] are shown to be driven unstable by the circulating and/or trapped alpha-particles through the wave-particle resonances. Satisfying the resonance condition requires that the alpha-particle birth speed upsilon-alpha greater-than-or-equal-to upsilon-A/2(m - nq), where upsilon-A is the Alfven speed, m is the poloidal mode number, and n is the toroidal mode number. To destabilize TAE modes, the inverse Landau damping associated with the alpha-particle pressure gradient free energy must overcome the velocity space Landau damping due to both the a particles and the core electrons and ions. The growth rate was studied analytically with a perturbative formula derived from the quadratic dispersion relation, and numerically with the aid of the NOVA-K Code. Stability criteria in terms of the a-particle beta-alpha, alpha-particle pressure parameter (omega-*/omega-A) (omega-* is the alpha-particle diamagnetic drift frequency), and (upsilon-alpha/upsilon-A) parameters will be presented for the Tokamak Fusion Test Reactor (TFTR) [Proceedings of the Thirteenth International Conference on Plasma Physics and Controlled Nuclear Fusion Research, Crystal City, VA, 1990 (International Atomic Energy Agency, Vienna, in press) J, Compact Ignition Tokamak (CIT) [Phys. Scr. T16, 89 (1987) ], and the International Thermonuclear Experimental Reactor (ITER) [ITER Documentation Series, No. 21 (International Atomic Energy Agency, Vienna, 1991)]. The volume-averaged alpha-particle beta threshold for TAE instability also depends sensitively on the core electron and ion temperature. Typically the volume-averaged a-particle beta threshold is in the order of 10(-4). Typical growth rates of the n = 1 TAE mode can be in the order of 10(-2)omega-A where omega-A = upsilon-A/qR . Other types of global Alfven waves are stable in deuterium-tritium (D-T) tokamaks due to toroidal coupling effects. RP CHENG, CZ (reprint author), PRINCETON UNIV,PLASMA PHYS LAB,PRINCETON,NJ 08543, USA. RI Cheng, Chio/K-1005-2014 NR 20 TC 64 Z9 64 U1 0 U2 5 PU AMER INST PHYSICS PI WOODBURY PA CIRCULATION FULFILLMENT DIV, 500 SUNNYSIDE BLVD, WOODBURY, NY 11797-2999 SN 0899-8221 J9 PHYS FLUIDS B-PLASMA PD SEP PY 1991 VL 3 IS 9 BP 2463 EP 2471 DI 10.1063/1.859618 PG 9 WC Physics, Fluids & Plasmas SC Physics GA GD009 UT WOS:A1991GD00900004 ER PT J AU ROMANELLI, F CHEN, L BRIGUGLIO, S AF ROMANELLI, F CHEN, L BRIGUGLIO, S TI KINETIC-THEORY OF THE ION-TEMPERATURE-GRADIENT-DRIVEN MODE IN THE LONG WAVELENGTH LIMIT SO PHYSICS OF FLUIDS B-PLASMA PHYSICS LA English DT Article ID DRIFT INSTABILITIES; TOKAMAKS; TRANSPORT; CONFINEMENT; STABILITY; PLASMA AB The stability of the ion-temperature-gradient-driven mode in the long wavelength limit is investigated by retaining the kinetic effects associated with the ion transit frequency. The complete trapped electron dynamics is also considered. The toroidal branch is weakly affected by the trapped electron dynamics while the slablike branch is more strongly affected by trapped electrons. The implications of these results for the understanding of the improved confinement regimes observed in the presence of peaked density profiles are also discussed. C1 PRINCETON UNIV,PLASMA PHYS LAB,PRINCETON,NJ 08544. RP ROMANELLI, F (reprint author), EURATOM,ENTE NAZL ENERGIA ATOM FUSIONE,CTR RIC ENERGIA,I-00044 FRASCATI,ITALY. OI Romanelli, Francesco/0000-0001-9778-1090 NR 31 TC 23 Z9 24 U1 1 U2 8 PU AMER INST PHYSICS PI WOODBURY PA CIRCULATION FULFILLMENT DIV, 500 SUNNYSIDE BLVD, WOODBURY, NY 11797-2999 SN 0899-8221 J9 PHYS FLUIDS B-PLASMA PD SEP PY 1991 VL 3 IS 9 BP 2496 EP 2505 DI 10.1063/1.859960 PG 10 WC Physics, Fluids & Plasmas SC Physics GA GD009 UT WOS:A1991GD00900007 ER PT J AU MIZUNO, K AF MIZUNO, K TI HOT-ELECTRON HEATING DUE TO RESONANCE-ABSORPTION OF MODERATE-INTENSITY MICROWAVES - MICROWAVE SIMULATION EXPERIMENT OF LASER PLASMA INTERACTION SO PHYSICS OF FLUIDS B-PLASMA PHYSICS LA English DT Article ID INHOMOGENEOUS PLASMAS; POLARIZATION; RADIATION; CAVITONS AB Microwave simulation experiments of laser-produced coronal plasma are presented. Extensive studies of hot electron heatings due to resonance absorption of moderate-intensity upsilon-0/upsilon-e < 0.3, or I-lambda2/T(e) < 3 X 10(14) W/cm2-mu-m2/keV), p-polarized microwaves have been made. A simple theory is developed based on warm plasma wave breaking to explain the experimental results. The experiments agree well with the theory and electromagnetic computer simulation calculations. Therefore, it is shown that the microwave experimental results of resonance absorption scale to laser parameters. RP MIZUNO, K (reprint author), UNIV CALIF LAWRENCE LIVERMORE NATL LAB,PLASMA PHYS RES INST,POB 808,L-418,LIVERMORE,CA 94550, USA. NR 21 TC 1 Z9 1 U1 2 U2 2 PU AMER INST PHYSICS PI WOODBURY PA CIRCULATION FULFILLMENT DIV, 500 SUNNYSIDE BLVD, WOODBURY, NY 11797-2999 SN 0899-8221 J9 PHYS FLUIDS B-PLASMA PD SEP PY 1991 VL 3 IS 9 BP 2532 EP 2539 DI 10.1063/1.859965 PG 8 WC Physics, Fluids & Plasmas SC Physics GA GD009 UT WOS:A1991GD00900012 ER PT J AU DAVIDSON, RC LUND, SM AF DAVIDSON, RC LUND, SM TI NONLINEAR STABILITY THEOREM FOR ROTATING COHERENT STRUCTURES IN A NONNEUTRAL PLASMA-COLUMN SO PHYSICS OF FLUIDS B-PLASMA PHYSICS LA English DT Article ID PURE ELECTRON PLASMAS; GUIDING-CENTER PLASMA; DIOCOTRON MODE; INSTABILITY; FLOW; MAGNETRONS; EQUILIBRIA; TRANSPORT; BEAMS; FIELD AB A nonlinear stability theorem is developed for arbitrary-amplitude, two-dimensional coherent structures, n(R)(theta - omega-r(t)) and phi-R(theta - omega-r(t)), in a strongly magnetized, low-density (omega-pe2/omega-ce2 << 1) non-neutral plasma column confined radially by a uniform axial magnetic field B0e(z). Here, a grounded, perfectly conducting, cylindrical wall is located at radius r = r-omega, and omega-r = const is the angular rotation velocity of the coherent structures about the cylinder axis (r = 0). A cold-fluid guiding-center model based on the continuity-Poisson equations is used to describe the nonlinear evolution of the electron density n(e)(r,theta,t) = n(R) + delta-n(e) and electrostatic potential phi(r,theta,t) = phi-R + delta-phi. Making use of global (spatially averaged) nonlinear conservation constraints, it is shown that partial-n(R)(psi-R)/partial-psi-R less-than-or-equal-to 0 is a sufficient condition for nonlinear stability of the rotating equilibrium state (phi-R,n(R)) to arbitrary-amplitude perturbations delta-n(e) and delta-phi. Here, psi-R(r,theta - omega-r(t)) = -e-phi-R(r,theta - omega-r(t)) + omega-r(eB0/2c)r2 is an effective streamfunction, and the stability theorem is valid no matter how complex the radial and azimuthal structure of phi-R(r,theta - omega-r(t)) and n(R)(r,theta - omega-r(t)). C1 MIT,CTR PLASMA FUS,CAMBRIDGE,MA 02139. RP DAVIDSON, RC (reprint author), PRINCETON UNIV,PLASMA PHYS LAB,PRINCETON,NJ 08543, USA. NR 39 TC 9 Z9 9 U1 0 U2 1 PU AMER INST PHYSICS PI WOODBURY PA CIRCULATION FULFILLMENT DIV, 500 SUNNYSIDE BLVD, WOODBURY, NY 11797-2999 SN 0899-8221 J9 PHYS FLUIDS B-PLASMA PD SEP PY 1991 VL 3 IS 9 BP 2540 EP 2547 DI 10.1063/1.859966 PG 8 WC Physics, Fluids & Plasmas SC Physics GA GD009 UT WOS:A1991GD00900013 ER PT J AU YOUNG, PE WYSOCKI, FJ YAMADA, M JANOS, A AF YOUNG, PE WYSOCKI, FJ YAMADA, M JANOS, A TI EXPERIMENTAL-STUDY OF A TRANSFORMER-DRIVEN SPHEROMAK PLASMA SO PHYSICS OF FLUIDS B-PLASMA PHYSICS LA English DT Article ID CONFIGURATION; STABILITY AB An axial transformer was installed in the Proto S-1/C spheromak device [Yamada et al, Phys. Rev. Lett. 46, 188 (1981)] in order to study physics issues pertaining to sustained spheromak operation. An increase in both the toroidal plasma current and the toroidal flux was observed when the transformer current was pulsed. The ratio of these two quantities remained constant (within experimental error) indicating that the equilibrium spheromak magnetic field was maintained through a relaxation mechanism. At transformer currents of 10 kA, the toroidal current increased from 37 to 51 kA and the toroidal flux increased from 3.7 X 10(5) to 4.4 x 10(5) G cm2. C1 PRINCETON UNIV,PLASMA PHYS LAB,PRINCETON,NJ 08544. RI Yamada, Masaaki/D-7824-2015 OI Yamada, Masaaki/0000-0003-4996-1649 NR 12 TC 2 Z9 2 U1 0 U2 1 PU AMER INST PHYSICS PI WOODBURY PA CIRCULATION FULFILLMENT DIV, 500 SUNNYSIDE BLVD, WOODBURY, NY 11797-2999 SN 0899-8221 J9 PHYS FLUIDS B-PLASMA PD SEP PY 1991 VL 3 IS 9 BP 2591 EP 2600 DI 10.1063/1.859971 PG 10 WC Physics, Fluids & Plasmas SC Physics GA GD009 UT WOS:A1991GD00900018 ER PT J AU BARNES, DC MILROY, RD AF BARNES, DC MILROY, RD TI STABILIZATION OF THE FIELD-REVERSED CONFIGURATION (FRC) TILT INSTABILITY WITH ENERGETIC ION-BEAMS SO PHYSICS OF FLUIDS B-PLASMA PHYSICS LA English DT Article ID PLASMA; MODE AB The stabilization of the internal tilt mode of a field-reversed configuration by injecting a minority energetic ion component has been investigated numerically. Calculations that follow ion orbits in a specified three-dimensional magnetic field configuration, corresponding to a partially tilted field-reversed configuration, demonstrate how a beam can provide a restoring force to the n = 1 tilt instability. A fully self-consistent three-dimensional numerical model, which treats the background plasma as a Hall fluid and the energetic ions as a collisionless Vlasov species, has also been developed. Calculations have been made for a variety of beam injection parameters, and indicate that the tilt mode can be stabilized with a beam energy of about 40% of the total, beam plus plasma, energy. C1 SPECTRA TECHNOL INC,BELLEVUE,WA 98004. RP BARNES, DC (reprint author), UNIV CALIF LOS ALAMOS SCI LAB,LOS ALAMOS,NM 87545, USA. NR 19 TC 31 Z9 31 U1 0 U2 2 PU AMER INST PHYSICS PI WOODBURY PA CIRCULATION FULFILLMENT DIV, 500 SUNNYSIDE BLVD, WOODBURY, NY 11797-2999 SN 0899-8221 J9 PHYS FLUIDS B-PLASMA PD SEP PY 1991 VL 3 IS 9 BP 2609 EP 2616 DI 10.1063/1.859973 PG 8 WC Physics, Fluids & Plasmas SC Physics GA GD009 UT WOS:A1991GD00900020 ER PT J AU REIMAN, AH AF REIMAN, AH TI TOKAMAK MAGNETIC ISLANDS IN THE PRESENCE OF NONAXISYMMETRIC PERTURBATIONS SO PHYSICS OF FLUIDS B-PLASMA PHYSICS LA English DT Article ID TEARING MODE; RECONNECTION; GROWTH AB The effects of a small, externally imposed, nonaxisymmetric magnetic field perturbation on magnetic islands are studied analytically, assuming zero-beta, tokamak ordering, and narrow islands. For the tearing stable case, the conditions under which the self-consistent plasma response is self-healing or amplifying are elucidated. For the tearing unstable case, the quasilinear theory of tearing modes is extended to a description of locked modes. RP REIMAN, AH (reprint author), PRINCETON UNIV,PLASMA PHYS LAB,PRINCETON,NJ 08543, USA. NR 16 TC 22 Z9 22 U1 0 U2 3 PU AMER INST PHYSICS PI WOODBURY PA CIRCULATION FULFILLMENT DIV, 500 SUNNYSIDE BLVD, WOODBURY, NY 11797-2999 SN 0899-8221 J9 PHYS FLUIDS B-PLASMA PD SEP PY 1991 VL 3 IS 9 BP 2617 EP 2625 DI 10.1063/1.859974 PG 9 WC Physics, Fluids & Plasmas SC Physics GA GD009 UT WOS:A1991GD00900021 ER PT J AU DEEG, HJ BOROVSKY, JE DURIC, N AF DEEG, HJ BOROVSKY, JE DURIC, N TI PARTICLE-ACCELERATION NEAR X-TYPE MAGNETIC NEUTRAL LINES SO PHYSICS OF FLUIDS B-PLASMA PHYSICS LA English DT Article ID RECONNECTION FIELD GEOMETRY; PLASMA SHEET; GEOMAGNETIC TAIL; COLLISIONLESS PLASMAS; PRESCRIBED FIELDS; ENERGETIC PROTON; DYNAMICS; ION; ORBITS; DISTRIBUTIONS AB The behavior of charged particles near X-type magnetic neutral lines is investigated. The magnetic field is taken to be hyperbolic and time stationary, with a uniform electric field perpendicular to the magnetic field. The general properties of the orbits of noninteracting particles in that field geometry are examined. Approximate analytic solutions to the orbit equations are derived by considering a magnetic-insulation picture where there is a hole in the magnetic insulation around the neutral line. Scaling laws for the dependence of the energy gain on strengths of the magnetic and electric fields are derived. The kinetic-energy distribution function for accelerated particles is derived for particles flowing past the neutral line. These analytic derivations are supported by computer simulations, in which the relativistic equations of motion for single test particles are numerically solved and the orbits and kinetic-energy gains of the particles are obtained. A number of simulations were performed and one parameter at a time was varied. Applications of the results to magnetic-neutral-line regions in space physics and astrophysics are possible. C1 UNIV NEW MEXICO,INST ASTROPHYS,ALBUQUERQUE,NM 87131. RP DEEG, HJ (reprint author), UNIV CALIF LOS ALAMOS SCI LAB,SPACE PLASMA PHYS GRP,LOS ALAMOS,NM 87545, USA. NR 49 TC 39 Z9 40 U1 0 U2 0 PU AMER INST PHYSICS PI WOODBURY PA CIRCULATION FULFILLMENT DIV, 500 SUNNYSIDE BLVD, WOODBURY, NY 11797-2999 SN 0899-8221 J9 PHYS FLUIDS B-PLASMA PD SEP PY 1991 VL 3 IS 9 BP 2660 EP 2674 DI 10.1063/1.859978 PG 15 WC Physics, Fluids & Plasmas SC Physics GA GD009 UT WOS:A1991GD00900025 ER PT J AU GILMAN, JJ AF GILMAN, JJ TI CENTRAL BUREAUCRACY STIFLES GOOD RESEARCH - REPLY SO PHYSICS TODAY LA English DT Letter RP GILMAN, JJ (reprint author), UNIV CALIF BERKELEY LAWRENCE BERKELEY LAB,BERKELEY,CA 94720, USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU AMER INST PHYSICS PI WOODBURY PA CIRCULATION FULFILLMENT DIV, 500 SUNNYSIDE BLVD, WOODBURY, NY 11797-2999 SN 0031-9228 J9 PHYS TODAY JI Phys. Today PD SEP PY 1991 VL 44 IS 9 BP 15 EP & PG 0 WC Physics, Multidisciplinary SC Physics GA GG167 UT WOS:A1991GG16700006 ER PT J AU MANN, V EKSTEIN, I NISSEN, H HISER, C MCINTOSH, L HIRSCHBERG, J AF MANN, V EKSTEIN, I NISSEN, H HISER, C MCINTOSH, L HIRSCHBERG, J TI THE CYTOCHROME OXIDASE-II GENE IN MITOCHONDRIA OF THE SUGAR-BEET BETA-VULGARIS L SO PLANT MOLECULAR BIOLOGY LA English DT Note DE CYTOCHROME-OXIDASE-II; MITOCHONDRIAL-DNA; SUGAR-BEET; INTRON; RNA EDITING ID CYTOPLASMIC MALE-STERILITY; SUBUNIT-II; PLANT-MITOCHONDRIA; SEQUENCE; INTRON; DNA; TRANSCRIPTS; MAIZE AB We have cloned and analyzed the sugar-beet mitochondrial gene for cytochrome oxidase subunit II (coxII). The sugar-beet and its deduced amino acid sequence were compared to its homologous coxII gene sequences from both monocot and dicot plants. It was found to be highly conserved (89-95%) compared to homologue in other plant species. The 780 bp coding sequence of the sugar beet coxII gene is interrupted at position 383 by a 1463 bp intron. This intron contains an additional 107 bp sequence that is not found in any of the plant coxII genes studied thus far. The structure of the intron suggests that a large intron existed in an ancestral coxII gene before monocots and dicots diverged in evolution. Three CGG codons in the sugar-beet coxII coding sequence align with conserved tryptophan residues in the homologous gene of other species, suggesting that RNA editing takes place also in sugar-beet mitochondria. In 13 out of 24 codons of coxII mRNA that were found to be edited in four other plants, the sugar-beet gene already utilizes the edited codons. This phenomenon may indicate that the mitochondrial genome in sugar-beet is phylogenetically more archaic relative to these plants. An additional sequence of 279 bp that is identical to the first exon of coxII was identified in the mtDNA of the sugar-beet. This 'pseudo-gene' is transcribed and its existence in the mitochondrial genome is unexplained. C1 HEBREW UNIV JERUSALEM,DEPT GENET,IL-91904 JERUSALEM,ISRAEL. MICHIGAN STATE UNIV,DOE,PLANT RES LAB,E LANSING,MI 48824. NR 26 TC 13 Z9 15 U1 0 U2 1 PU KLUWER ACADEMIC PUBL PI DORDRECHT PA SPUIBOULEVARD 50, PO BOX 17, 3300 AA DORDRECHT, NETHERLANDS SN 0167-4412 J9 PLANT MOL BIOL JI Plant Mol.Biol. PD SEP PY 1991 VL 17 IS 3 BP 559 EP 566 DI 10.1007/BF00040657 PG 8 WC Biochemistry & Molecular Biology; Plant Sciences SC Biochemistry & Molecular Biology; Plant Sciences GA GF079 UT WOS:A1991GF07900031 PM 1653062 ER PT J AU LAROCHE, J MORTAINBERTRAND, A FALKOWSKI, PG AF LAROCHE, J MORTAINBERTRAND, A FALKOWSKI, PG TI LIGHT INTENSITY-INDUCED CHANGES IN CAB MESSENGER-RNA AND LIGHT HARVESTING COMPLEX-II APOPROTEIN LEVELS IN THE UNICELLULAR CHLOROPHYTE DUNALIELLA-TERTIOLECTA SO PLANT PHYSIOLOGY LA English DT Article ID PHOTOSYSTEM-II; CHLAMYDOMONAS-REINHARDTII; MARINE CHLOROPHYTE; GROWTH-IRRADIANCE; PROTEIN COMPLEXES; HIGHER-PLANTS; GREEN-ALGA; ADAPTATION; PHYTOPLANKTON; ACCUMULATION AB During a transition from high growth irradiance (700 micromoles quanta per square meter per second) to low growth irradiance (70 micromoles quanta per square meter per second), the unicellular marine chlorophyte Dunaliella tertiolecta Butcher increases the cellular pool size of the light-harvesting complex of photosystem II (LHC II). We showed that the increase in LHC II apoproteins and in chlorophyll content per cell is preceded by an approximately fourfold increase in cab mRNA. The increase in cab mRNA is detectable within 1.5 hours following a shift from high to low light intensity. An increase in the relative abundance of cab mRNA was also found following a shift from high light to darkness and from high light to low light in the presence of gabaculine, a chlorophyll synthesis inhibitor. However, the LHC II apoproteins did not accumulate in the latter experiments, suggesting that LHC II apoprotein synthesis is coupled to chlorophyll synthesis at or beyond translation. We propose that changes in energy balance brought about by a change in light intensity may control a regulatory factor acting to repress cab mRNA expression in high light. RP LAROCHE, J (reprint author), BROOKHAVEN NATL LAB,DIV OCEANOG & ATMOSPHER SCI,UPTON,NY 11973, USA. RI LaRoche, Julie/A-1109-2010 NR 30 TC 57 Z9 59 U1 0 U2 4 PU AMER SOC PLANT PHYSIOLOGISTS PI ROCKVILLE PA 15501 MONONA DRIVE, ROCKVILLE, MD 20855 SN 0032-0889 J9 PLANT PHYSIOL JI Plant Physiol. PD SEP PY 1991 VL 97 IS 1 BP 147 EP 153 DI 10.1104/pp.97.1.147 PG 7 WC Plant Sciences SC Plant Sciences GA GJ793 UT WOS:A1991GJ79300022 PM 16668361 ER PT J AU RAMSHAW, JD CHANG, CH AF RAMSHAW, JD CHANG, CH TI AMBIPOLAR DIFFUSION IN MULTICOMPONENT PLASMAS SO PLASMA CHEMISTRY AND PLASMA PROCESSING LA English DT Article DE DIFFUSION; AMBIPOLAR DIFFUSION; MULTICOMPONENT PLASMAS ID HELIUM AB A recently described self-consistent effective binary diffusion approximation is applied to ambipolar diffusion in a neutral multicomponent plasma in zero magnetic field, where forced diffusion due to the electric field E plays an essential role. The field E is determined by the constraint that the net current flow produced by the diffusion fluxes must be zero. The resulting effective binary diffusion fluxes are the sum of those that would obtain for E = 0 and ambipolar correction terms proportional to E. The formulation is self-consistent with respect to both mass and charge, the net diffusional fluxes of which are both identically zero. The results may be further simplified due to the small mass of the electrons. The effective binary diffusivity D(e) of the electrons no longer appears in the simplified expressions. They are therefore well suited to numerical calculations, where the large value of D(e) might otherwise have resulted in unacceptable stability or accuracy restrictions. The well-known effective doubling of ion diffusivities due to ambipolar diffusion occurs in simple situations but is not a general feature. RP RAMSHAW, JD (reprint author), EG&G IDAHO INC,IDAHO NATL ENGN LAB,POB 1625,IDAHO FALLS,ID 83415, USA. NR 14 TC 31 Z9 32 U1 0 U2 1 PU PLENUM PUBL CORP PI NEW YORK PA 233 SPRING ST, NEW YORK, NY 10013 SN 0272-4324 J9 PLASMA CHEM PLASMA P JI Plasma Chem. Plasma Process. PD SEP PY 1991 VL 11 IS 3 BP 395 EP 402 DI 10.1007/BF01458919 PG 8 WC Engineering, Chemical; Physics, Applied; Physics, Fluids & Plasmas SC Engineering; Physics GA FW026 UT WOS:A1991FW02600006 ER PT J AU CRISSMAN, HA GADBOIS, DM TOBEY, RA BRADBURY, EM AF CRISSMAN, HA GADBOIS, DM TOBEY, RA BRADBURY, EM TI TRANSFORMED MAMMALIAN-CELLS ARE DEFICIENT IN KINASE-MEDIATED CONTROL OF PROGRESSION THROUGH THE G1 PHASE OF THE CELL-CYCLE SO PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF THE UNITED STATES OF AMERICA LA English DT Article DE STAUROSPORINE; CELL PROLIFERATION; GROWTH INHIBITION; FLOW CYTOMETRY ID HUMAN-DIPLOID FIBROBLASTS; CHINESE-HAMSTER CELLS; RETINOBLASTOMA SUSCEPTIBILITY GENE; PROTEIN-KINASE; KARYOTYPE INSTABILITY; RESTRICTION POINT; FISSION YEAST; STAUROSPORINE; PRODUCT; PHOSPHORYLATION AB To investigate the role of kinase-mediated mechanisms in regulating mammalian cell proliferation, we determined the effects of the general protein kinase inhibitor staurosporine on the proliferation of a series of nontransformed and transformed cultured rodent and human cells. Levels of staurosporine as low as 1 ng/ml prevented nontransformed cells from entering S phase (i.e., induced G1 arrest), indicating that kinase-mediated processes are essential for commitment to DNA replication in normal cells. At higher concentrations of staurosporine (50-75 ng/ml), nontransformed mammalian cells were arrested in both G1 and G2. The period of sensitivity of nontransformed human diploid fibroblasts to low levels of the drug commenced 3 hr later than the G0/G1 boundary and extended through the G1/S boundary. Interference with activity of the G1-essential kinase(s) caused nontransformed human cells traversing mid-to-late G1 at the time of staurosporine addition to be "set back" to the initial staurosporine block point, suggesting the existence of a kinase-dependent "G1 clock" mechanism that must function continuously throughout the early cycle in normal cells. The initial staurosporine block point at 3 hr into G1 corresponds to neither the serum nor the amino acid restriction point. In marked contrast to the behavior of nontransformed cells, neither low nor high concentrations of staurosporine affected G1 progression in transformed cultures; high drug concentrations caused transformed cells to be arrested solely in G2. These results indicate that kinase-mediated regulation of DNA replication is lost as the result of neoplastic transformation, but the G2-arrest mechanism remains intact. C1 UNIV CALIF DAVIS,SCH MED,DEPT BIOL CHEM,DAVIS,CA 95616. RP CRISSMAN, HA (reprint author), UNIV CALIF LOS ALAMOS SCI LAB,DIV LIFE SCI,LS-1,MS-M888,LOS ALAMOS,NM 87545, USA. FU NCRR NIH HHS [P41-RR01315] NR 37 TC 139 Z9 139 U1 0 U2 2 PU NATL ACAD SCIENCES PI WASHINGTON PA 2101 CONSTITUTION AVE NW, WASHINGTON, DC 20418 SN 0027-8424 J9 P NATL ACAD SCI USA JI Proc. Natl. Acad. Sci. U. S. A. PD SEP PY 1991 VL 88 IS 17 BP 7580 EP 7584 DI 10.1073/pnas.88.17.7580 PG 5 WC Multidisciplinary Sciences SC Science & Technology - Other Topics GA GC992 UT WOS:A1991GC99200027 PM 1652754 ER PT J AU BULTMAN, SJ RUSSELL, LB GUTIERREZESPELETA, GA WOYCHIK, RP AF BULTMAN, SJ RUSSELL, LB GUTIERREZESPELETA, GA WOYCHIK, RP TI MOLECULAR CHARACTERIZATION OF A REGION OF DNA ASSOCIATED WITH MUTATIONS AT THE AGOUTI LOCUS IN THE MOUSE SO PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF THE UNITED STATES OF AMERICA LA English DT Article DE RADIATION MUTAGENESIS; MOLECULAR ANALYSIS OF MUTATIONS ID COAT COLOR LOCUS; GENETIC-CHARACTERIZATION; LIMB DEFORMITY; YELLOW; ALLELE; AY; CHROMOSOME-2; MARKERS; STRAIN; MICE AB Molecular characterization of a radiation-induced agouti (a)-locus mutation has resulted in the isolation of a segment of DNA that maps at or near the a locus on chromosome 2 in the mouse. This region of DNA is deleted in several radiation- or chemical-induced homozygous-lethal a-locus mutations and is associated with specific DNA structural alterations in two viable a-locus mutations. We propose that DNA probes from this region of chromosome 2 will be useful for ultimately characterizing the individual gene or genes associated with a-locus function. C1 OAK RIDGE NATL LAB,DIV BIOL,OAK RIDGE,TN 37831. UNIV TENNESSEE,GRAD SCH BIOMED SCI,OAK RIDGE,TN 37831. UNIV COSTA RICA,ESCUELA BIOL,SAN JOSE,COSTA RICA. FU NIEHS NIH HHS [IAG 22Y01-ES-10067] NR 35 TC 28 Z9 29 U1 0 U2 2 PU NATL ACAD SCIENCES PI WASHINGTON PA 2101 CONSTITUTION AVE NW, WASHINGTON, DC 20418 SN 0027-8424 J9 P NATL ACAD SCI USA JI Proc. Natl. Acad. Sci. U. S. A. PD SEP PY 1991 VL 88 IS 18 BP 8062 EP 8066 DI 10.1073/pnas.88.18.8062 PG 5 WC Multidisciplinary Sciences SC Science & Technology - Other Topics GA GF101 UT WOS:A1991GF10100034 PM 1896452 ER PT J AU MANDIYAN, V TUMMINIA, SJ WALL, JS HAINFELD, JF BOUBLIK, M AF MANDIYAN, V TUMMINIA, SJ WALL, JS HAINFELD, JF BOUBLIK, M TI ASSEMBLY OF THE ESCHERICHIA-COLI 30S RIBOSOMAL-SUBUNIT REVEALS PROTEIN-DEPENDENT FOLDING OF THE 16S RIBOSOMAL-RNA DOMAINS SO PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF THE UNITED STATES OF AMERICA LA English DT Article ID ACETYLVALYL TRANSFER-RNA; 3' MAJOR DOMAIN; 3-DIMENSIONAL STRUCTURE; 16S-RIBOSOMAL RNA; BINDING; MODEL; NUCLEOTIDES; SITES; S13 AB Protein-nucleic acid interactions involved in the assembly process of the Escherichia coli 30S ribosomal subunit were quantitatively analyzed by high-resolution scanning transmission electron microscopy. The in vitro reconstituted ribonucleoprotein (core) particles were characterized by their morphology, mass, and radii of gyration. During the assembly of the 30S subunit, the 16S rRNA underwent significant conformational changes that were governed by the cooperative interactions of the ribosomal proteins. The sequential association of the first 12 proteins with the 16S rRNA resulted in the formation of core particles containing up to three mass centers at distinct stages of the assembly process. These globular mass centers may correspond to the three major domains (5', central, and 3') of the 16S rRNA. Through the subsequent interactions of the late assembly proteins with the 16S rRNA, two of the three domains merge, yielding the basic structural traits of the native 30S subunit. The fine morphological features of the native 30S subunit became distinctly resolved only after the addition of the full complement of proteins. The fully reconstituted 30S subunits are active in polyphenylalanine synthesis assays. Visualization of the assembly mechanism of the E. coli 30S ribosomal subunit revealed domain-specific folding of the 16S rRNA through the formation of distinct intermediate core particles hitherto not observed. C1 ROCHE INST MOLEC BIOL,ROCHE RES CTR,NUTLEY,NJ 07110. BROOKHAVEN NATL LAB,DEPT BIOL,UPTON,NY 11973. FU NCRR NIH HHS [RRO1777] NR 48 TC 26 Z9 27 U1 1 U2 1 PU NATL ACAD SCIENCES PI WASHINGTON PA 2101 CONSTITUTION AVE NW, WASHINGTON, DC 20418 SN 0027-8424 J9 P NATL ACAD SCI USA JI Proc. Natl. Acad. Sci. U. S. A. PD SEP PY 1991 VL 88 IS 18 BP 8174 EP 8178 DI 10.1073/pnas.88.18.8174 PG 5 WC Multidisciplinary Sciences SC Science & Technology - Other Topics GA GF101 UT WOS:A1991GF10100057 PM 1896466 ER PT J AU EBBE, S AF EBBE, S TI REGULATION OF MURINE MEGAKARYOCYTE SIZE AND PLOIDY BY NON-PLATELET-DEPENDENT MECHANISMS IN RADIATION-INDUCED MEGAKARYOCYTOPENIA SO RADIATION RESEARCH LA English DT Article ID STEM-CELL FACTOR; TYROSINE KINASE RECEPTOR; GROWTH-FACTOR; W-LOCUS; PROTO-ONCOGENE; MICE; MOUSE; THROMBOCYTOPENIA; INTERLEUKIN-6; LIGAND C1 UNIV CALIF SAN FRANCISCO,DEPT LAB MED,SAN FRANCISCO,CA 94143. RP EBBE, S (reprint author), UNIV CALIF BERKELEY LAWRENCE BERKELEY LAB,BERKELEY,CA 94720, USA. FU NIADDK NIH HHS [AM21355] NR 40 TC 12 Z9 12 U1 0 U2 0 PU RADIATION RESEARCH SOC PI OAK BROOK PA 2021 SPRING RD, STE 600, OAK BROOK, IL 60521 SN 0033-7587 J9 RADIAT RES JI Radiat. Res. PD SEP PY 1991 VL 127 IS 3 BP 278 EP 284 DI 10.2307/3577942 PG 7 WC Biology; Biophysics; Radiology, Nuclear Medicine & Medical Imaging SC Life Sciences & Biomedicine - Other Topics; Biophysics; Radiology, Nuclear Medicine & Medical Imaging GA GD985 UT WOS:A1991GD98500007 PM 1886983 ER PT J AU FREYER, JP JARRETT, K CARPENTER, S RAJU, MR AF FREYER, JP JARRETT, K CARPENTER, S RAJU, MR TI OXYGEN ENHANCEMENT RATIO AS A FUNCTION OF DOSE AND CELL-CYCLE PHASE FOR RADIATION-RESISTANT AND SENSITIVE CHO CELLS SO RADIATION RESEARCH LA English DT Article ID CHINESE-HAMSTER CELLS; HYPOXIC CELLS; AGE RESPONSE; OVARY CELL; X-RAYS; SURVIVAL; RADIOSENSITIZATION; REPAIR; SPHEROIDS; SENSITIZATION RP FREYER, JP (reprint author), UNIV CALIF LOS ALAMOS SCI LAB,DIV LIFE SCI,CELLULAR & MOLEC BIOL GRP,MAIL STOP M888,LOS ALAMOS,NM 87545, USA. FU NCI NIH HHS [CA-22585, CA-36535]; NCRR NIH HHS [RR-01315] NR 38 TC 25 Z9 25 U1 2 U2 3 PU RADIATION RESEARCH SOC PI OAK BROOK PA 2021 SPRING RD, STE 600, OAK BROOK, IL 60521 SN 0033-7587 J9 RADIAT RES JI Radiat. Res. PD SEP PY 1991 VL 127 IS 3 BP 297 EP 307 DI 10.2307/3577945 PG 11 WC Biology; Biophysics; Radiology, Nuclear Medicine & Medical Imaging SC Life Sciences & Biomedicine - Other Topics; Biophysics; Radiology, Nuclear Medicine & Medical Imaging GA GD985 UT WOS:A1991GD98500010 PM 1886986 ER PT J AU CHEN, KC WARNE, LK AF CHEN, KC WARNE, LK TI IMPROVED ASYMPTOTIC EXPANSIONS OF TIME DOMAIN ANTENNA CURRENT SO RADIO SCIENCE LA English DT Article ID INFINITE CYLINDRICAL-ANTENNA AB An improved asymptotic series for an integral representing transient current on an infinite cylindrical antenna caused by a step voltage source, applied at the gap, is given. A generating function for obtaining the general coefficient is derived. The method is applicable to types of integrals whose integrands consist of a product of a slowly varying function and a rapidly varying function. A simple accurate formula obtained before, by the averaging method, is shown to be the leading term of this infinite series. The averaging used in evaluating integrals is shown to improve the accuracy of the leading term. RP CHEN, KC (reprint author), SANDIA NATL LABS,DIV 7553,POB 5800,ALBUQUERQUE,NM 87185, USA. NR 11 TC 2 Z9 2 U1 0 U2 0 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 SN 0048-6604 J9 RADIO SCI JI Radio Sci. PD SEP-OCT PY 1991 VL 26 IS 5 BP 1205 EP 1208 DI 10.1029/91RS01415 PG 4 WC Astronomy & Astrophysics; Geochemistry & Geophysics; Meteorology & Atmospheric Sciences; Remote Sensing; Telecommunications SC Astronomy & Astrophysics; Geochemistry & Geophysics; Meteorology & Atmospheric Sciences; Remote Sensing; Telecommunications GA GJ939 UT WOS:A1991GJ93900005 ER PT J AU TATCHYN, R AF TATCHYN, R TI ON A NEW CLASS OF FIELD INTEGRAL CONSTRAINTS FOR ASYMMETRIC ADJUSTABLE-PHASE INSERTION DEVICES SO REVIEW OF SCIENTIFIC INSTRUMENTS LA English DT Article AB Some alternative methods of tuning variable-field transverse insertion devices that longitudinally displace the jaws of otherwise ordinary undulator structures have been recently proposed. In this article we discuss some of the off-axis characteristics of such schemes that could limit their range of tunability and affect their possible modes of implementation on conventional storage rings. Based on the corresponding analysis, a new set of field integral constraints for facilitating the operation of such devices is derived. C1 UNIV OREGON,INST THEORET SCI,EUGENE,OR 97403. RP TATCHYN, R (reprint author), STANFORD UNIV,STANFORD SYNCHROTRON RADIAT LAB,STANFORD,CA 94305, 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 SEP PY 1991 VL 62 IS 9 BP 2063 EP 2068 DI 10.1063/1.1142367 PG 6 WC Instruments & Instrumentation; Physics, Applied SC Instruments & Instrumentation; Physics GA GD506 UT WOS:A1991GD50600001 ER PT J AU HULETT, LD DONOHUE, DL LEWIS, TA AF HULETT, LD DONOHUE, DL LEWIS, TA TI A QUADRATIC POTENTIAL TIME-OF-FLIGHT MASS-SPECTROMETER FOR USE WITH SLOW POSITRON IONIZATION SOURCES AND OTHER LARGE-VOLUME ION SOURCES SO REVIEW OF SCIENTIFIC INSTRUMENTS LA English DT Article AB A time-of-flight spectrometer has been specially designed for measuring the masses of ions produced by low-energy positrons interacting with organic molecules in a Penning trap. To make the flight times insensitive to the starting positions of the ions in the trap, acceleration was done using a potential that varied as the square of the distance of the ion from the detector. The containment of the positrons in the Penning trap for extended time periods effected very long collision paths between the positrons and the molecules. The entire length of the Penning trap source could be sampled. These features produced high sensitivity, enabling the measurement of ionization processes with small cross sections. The spectrometer is useful for mass spectrometry of ions produced by processes other than positron interaction. Both large and small volume sources can be accommodated. RP HULETT, LD (reprint author), OAK RIDGE NATL LAB,OAK RIDGE,TN 37831, USA. NR 6 TC 33 Z9 33 U1 0 U2 1 PU AMER INST PHYSICS PI WOODBURY PA CIRCULATION FULFILLMENT DIV, 500 SUNNYSIDE BLVD, WOODBURY, NY 11797-2999 SN 0034-6748 J9 REV SCI INSTRUM JI Rev. Sci. Instrum. PD SEP PY 1991 VL 62 IS 9 BP 2131 EP 2137 DI 10.1063/1.1142327 PG 7 WC Instruments & Instrumentation; Physics, Applied SC Instruments & Instrumentation; Physics GA GD506 UT WOS:A1991GD50600013 ER PT J AU GINSBERG, MJ ASAY, BW AF GINSBERG, MJ ASAY, BW TI COMMERCIAL CARBON COMPOSITION RESISTORS AS DYNAMIC STRESS GAUGES IN DIFFICULT ENVIRONMENTS SO REVIEW OF SCIENTIFIC INSTRUMENTS LA English DT Article ID MANGANIN AB Commercial carbon composition resistors have been used as gauges to make dynamic stress measurements in homogeneous and heterogeneous reactive and inert materials. Initial loading was provided by plane wave lenses or shaped charge jets. A series of gas gun and aquarium experiments has been conducted to characterize the behavior of the gauges. Calibrations up to about 14 GPa for nominal 470 OMEGA-resistors and 17 GPa for nominal 4700 OMEGA-resistors are presented. The accuracy of the carbon resistor gauges is limited by response time considerations when submicrosecond rise times are encountered, and there is hysteresis during release. The gauge-to-gauge reproducibility appears to be adequate, and they survive in situations where no other stress transducer has been successfully used, such as in reacting beds of large-particle gun propellants. RP GINSBERG, MJ (reprint author), UNIV CALIF LOS ALAMOS SCI LAB,MS J960,LOS ALAMOS,NM 87545, USA. NR 24 TC 16 Z9 16 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 SEP PY 1991 VL 62 IS 9 BP 2218 EP 2227 DI 10.1063/1.1142340 PG 10 WC Instruments & Instrumentation; Physics, Applied SC Instruments & Instrumentation; Physics GA GD506 UT WOS:A1991GD50600027 ER PT J AU FASCHING, GE SMITH, NS AF FASCHING, GE SMITH, NS TI A CAPACITIVE SYSTEM FOR 3-DIMENSIONAL IMAGING OF FLUIDIZED-BEDS SO REVIEW OF SCIENTIFIC INSTRUMENTS LA English DT Article ID RAY COMPUTED-TOMOGRAPHY; FLOW; FACILITY AB A novel capacitance imaging system (CIS) has been developed which has unique capabilities for providing real-time, three-dimensional monitoring of fluidized-bed density. While the system was developed primarily to serve as a high-speed, density-imaging tool in fluidization research and development, it could also be used in other applications, such as pipeline transfer of solids, where multiphase dielectric material density changes are to be monitored. The CIS uses 16 evenly spaced, circumferentially located electrodes at each of four levels evenly spaced along the axis of a 6-in. diam fluidized bed as the density-sensing elements. The electronic system utilizes interelectrode displacement current values to obtain bed density estimates at each of the 49 pixels defined at each of the four levels. The system provides a real-time display of each of the four density maps at a rate of 30 maps per second at each level. The system also stores displacement current data, updated 100 times per second, for post-run analysis of bed behavior. The CIS capabilities are demonstrated for a plastic bead bed material. Density maps show the progression of a low-density region upward through a fluidized bed. Experimental use of the system by others produced values of bubble dimension and velocity that are consistent with values predicted by accepted theory. RP FASCHING, GE (reprint author), US DOE MORGANTOWN ENERGY TECHNOL CTR,POB 880,MORGANTOWN,WV 26507, USA. NR 10 TC 50 Z9 57 U1 0 U2 3 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 SEP PY 1991 VL 62 IS 9 BP 2243 EP 2251 DI 10.1063/1.1142343 PG 9 WC Instruments & Instrumentation; Physics, Applied SC Instruments & Instrumentation; Physics GA GD506 UT WOS:A1991GD50600030 ER PT J AU VANDERVOORT, KG GRIFFITH, G CLAUS, H CRABTREE, GW AF VANDERVOORT, KG GRIFFITH, G CLAUS, H CRABTREE, GW TI A LOW FIELD SQUID MAGNETOMETER SYSTEM FOR MAGNETIC CHARACTERIZATION OF HIGH-TC SUPERCONDUCTING SAMPLES SO REVIEW OF SCIENTIFIC INSTRUMENTS LA English DT Article ID SINGLE-CRYSTALS; TEMPERATURE AB In this article we describe a simple SQUID magnetometer system useful for the magnetic characterization of high temperature superconductors. The system employs a commercial rf SQUID probe with associated electronics located in a He-4 gas exchange cryostat. The system is equipped with a copper coil dc magnet for fields up to 50 Gauss. The cryostat is surrounded by a mu-metal shield that keeps the remanent field to less than 20 mGauss. The apparatus has been used extensively to measure both the superconducting transition temperature and width as well as the relative quantities of magnetic flux expulsion and exclusion. It has therefore served as an important first step in the evaluation of sample quality. C1 ARGONNE NATL LAB,SCI & TECHNOL CTR SUPERCONDUCTIV,ARGONNE,IL 60439. ARGONNE NATL LAB,DIV MAT SCI,ARGONNE,IL 60439. RP VANDERVOORT, KG (reprint author), UNIV ILLINOIS,DEPT PHYS,CHICAGO,IL 60680, USA. NR 19 TC 28 Z9 28 U1 1 U2 4 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 SEP PY 1991 VL 62 IS 9 BP 2271 EP 2275 DI 10.1063/1.1142348 PG 5 WC Instruments & Instrumentation; Physics, Applied SC Instruments & Instrumentation; Physics GA GD506 UT WOS:A1991GD50600035 ER PT J AU SINGH, MP TRAVIS, CC AF SINGH, MP TRAVIS, CC TI ENVIRONMENTAL RISK ANALYSIS - AN OVERVIEW SO RISK ANALYSIS LA English DT Editorial Material C1 OAK RIDGE NATL LAB,OAK RIDGE,TN. RP SINGH, MP (reprint author), INDIAN INST TECHNOL,NEW DELHI 110029,INDIA. NR 0 TC 2 Z9 2 U1 0 U2 2 PU PLENUM PUBL CORP PI NEW YORK PA 233 SPRING ST, NEW YORK, NY 10013 SN 0272-4332 J9 RISK ANAL JI Risk Anal. PD SEP PY 1991 VL 11 IS 3 BP 377 EP 379 DI 10.1111/j.1539-6924.1991.tb00620.x PG 3 WC Public, Environmental & Occupational Health; Mathematics, Interdisciplinary Applications; Social Sciences, Mathematical Methods SC Public, Environmental & Occupational Health; Mathematics; Mathematical Methods In Social Sciences GA GJ337 UT WOS:A1991GJ33700005 PM 1947341 ER PT J AU WHITE, RK AF WHITE, RK TI PURDUE-UNIVERSITY INDUSTRIAL-WASTE CONFERENCE PROCEEDINGS - BELL,JM SO RISK ANALYSIS LA English DT Book Review RP WHITE, RK (reprint author), OAK RIDGE NATL LAB,RISK ANAL SECT,CHINN BLDG,MS-6492,OAK RIDGE,TN 37831, USA. NR 1 TC 0 Z9 0 U1 0 U2 0 PU PLENUM PUBL CORP PI NEW YORK PA 233 SPRING ST, NEW YORK, NY 10013 SN 0272-4332 J9 RISK ANAL JI Risk Anal. PD SEP PY 1991 VL 11 IS 3 BP 561 EP 561 PG 1 WC Public, Environmental & Occupational Health; Mathematics, Interdisciplinary Applications; Social Sciences, Mathematical Methods SC Public, Environmental & Occupational Health; Mathematics; Mathematical Methods In Social Sciences GA GJ337 UT WOS:A1991GJ33700027 ER PT J AU WHITE, RK AF WHITE, RK TI BRIEFBOOK - BIOTECHNOLOGY, MICROBES AND THE ENVIRONMENT - WITT,SC SO RISK ANALYSIS LA English DT Book Review RP WHITE, RK (reprint author), OAK RIDGE NATL LAB,RISK ANAL SECT,CHINN BLDG,MS-6492,OAK RIDGE,TN 37831, USA. NR 1 TC 0 Z9 0 U1 0 U2 0 PU PLENUM PUBL CORP PI NEW YORK PA 233 SPRING ST, NEW YORK, NY 10013 SN 0272-4332 J9 RISK ANAL JI Risk Anal. PD SEP PY 1991 VL 11 IS 3 BP 561 EP 561 PG 1 WC Public, Environmental & Occupational Health; Mathematics, Interdisciplinary Applications; Social Sciences, Mathematical Methods SC Public, Environmental & Occupational Health; Mathematics; Mathematical Methods In Social Sciences GA GJ337 UT WOS:A1991GJ33700026 ER PT J AU WHITE, RK AF WHITE, RK TI HEALTH AND SAFETY IN SMALL INDUSTRY - A PRACTICAL GUIDE FOR MANAGERS - UNIV-MED-DENT-NEW-JERSEY-DEPT-ENVIRONM-COMMUNITY-MED-ENVIRONM-OCCUPAT-HL TH-INFORMAT-PROGRAM SO RISK ANALYSIS LA English DT Book Review RP WHITE, RK (reprint author), OAK RIDGE NATL LAB,RISK ANAL SECT,CHINN BLDG,MS-6492,OAK RIDGE,TN 37831, USA. NR 1 TC 0 Z9 0 U1 0 U2 0 PU PLENUM PUBL CORP PI NEW YORK PA 233 SPRING ST, NEW YORK, NY 10013 SN 0272-4332 J9 RISK ANAL JI Risk Anal. PD SEP PY 1991 VL 11 IS 3 BP 561 EP 562 PG 2 WC Public, Environmental & Occupational Health; Mathematics, Interdisciplinary Applications; Social Sciences, Mathematical Methods SC Public, Environmental & Occupational Health; Mathematics; Mathematical Methods In Social Sciences GA GJ337 UT WOS:A1991GJ33700028 ER PT J AU WHITE, RK AF WHITE, RK TI DRINKING-WATER HEALTH ADVISORY - PESTICIDES - US-ENVIRONM-PROTECT-AGCY-OFF-DRINKING-WATER-HLTH-ADVISORIES SO RISK ANALYSIS LA English DT Book Review RP WHITE, RK (reprint author), OAK RIDGE NATL LAB,RISK ANAL SECT,CHINN BLDG,MS-6492,OAK RIDGE,TN 37831, USA. NR 1 TC 0 Z9 0 U1 0 U2 1 PU PLENUM PUBL CORP PI NEW YORK PA 233 SPRING ST, NEW YORK, NY 10013 SN 0272-4332 J9 RISK ANAL JI Risk Anal. PD SEP PY 1991 VL 11 IS 3 BP 562 EP 562 PG 1 WC Public, Environmental & Occupational Health; Mathematics, Interdisciplinary Applications; Social Sciences, Mathematical Methods SC Public, Environmental & Occupational Health; Mathematics; Mathematical Methods In Social Sciences GA GJ337 UT WOS:A1991GJ33700029 ER PT J AU WHITE, RK AF WHITE, RK TI SAFETY SERIES, VOL 100, EVALUATING THE RELIABILITY OF PREDICTIONS MADE USING ENVIRONMENTAL TRANSFER MODELS - INT-ATOM-ENERGY-AGCY SO RISK ANALYSIS LA English DT Book Review RP WHITE, RK (reprint author), OAK RIDGE NATL LAB,RISK ANAL SECT,CHINN BLDG,MS-6492,OAK RIDGE,TN 37831, USA. NR 1 TC 0 Z9 0 U1 0 U2 1 PU PLENUM PUBL CORP PI NEW YORK PA 233 SPRING ST, NEW YORK, NY 10013 SN 0272-4332 J9 RISK ANAL JI Risk Anal. PD SEP PY 1991 VL 11 IS 3 BP 562 EP 562 PG 1 WC Public, Environmental & Occupational Health; Mathematics, Interdisciplinary Applications; Social Sciences, Mathematical Methods SC Public, Environmental & Occupational Health; Mathematics; Mathematical Methods In Social Sciences GA GJ337 UT WOS:A1991GJ33700030 ER PT J AU WHITE, RK AF WHITE, RK TI HANDBOOK OF ENVIRONMENTAL FATE AND EXPOSURE OF ORGANIC-CHEMICALS, VOL 1, LARGE PRODUCTION AND PRIORITY POLLUTANTS - HOWARD,PH SO RISK ANALYSIS LA English DT Book Review RP WHITE, RK (reprint author), OAK RIDGE NATL LAB,RISK ANAL SECT,CHINN BLDG,MS-6492,OAK RIDGE,TN 37831, USA. NR 1 TC 0 Z9 0 U1 0 U2 3 PU PLENUM PUBL CORP PI NEW YORK PA 233 SPRING ST, NEW YORK, NY 10013 SN 0272-4332 J9 RISK ANAL JI Risk Anal. PD SEP PY 1991 VL 11 IS 3 BP 563 EP 564 PG 2 WC Public, Environmental & Occupational Health; Mathematics, Interdisciplinary Applications; Social Sciences, Mathematical Methods SC Public, Environmental & Occupational Health; Mathematics; Mathematical Methods In Social Sciences GA GJ337 UT WOS:A1991GJ33700033 ER PT J AU WHITE, RK AF WHITE, RK TI IRRIGATION-INDUCED WATER-QUALITY PROBLEMS - WHAT CAN BE LEARNED FROM THE SAN-JOAQUIN VALLEY EXPERIENCE - NATL-RES-COUNCIL-COMMISS-PHYS-SCI-MATH-RESOURCES-WATER-SCI-TECHNOL-BOARD -COMM-IRRIGAT-INDUCED-WATER-QUAL-PROBLEMS SO RISK ANALYSIS LA English DT Book Review RP WHITE, RK (reprint author), OAK RIDGE NATL LAB,RISK ANAL SECT,CHINN BLDG,MS-6492,OAK RIDGE,TN 37831, USA. NR 1 TC 0 Z9 0 U1 0 U2 3 PU PLENUM PUBL CORP PI NEW YORK PA 233 SPRING ST, NEW YORK, NY 10013 SN 0272-4332 J9 RISK ANAL JI Risk Anal. PD SEP PY 1991 VL 11 IS 3 BP 563 EP 563 PG 1 WC Public, Environmental & Occupational Health; Mathematics, Interdisciplinary Applications; Social Sciences, Mathematical Methods SC Public, Environmental & Occupational Health; Mathematics; Mathematical Methods In Social Sciences GA GJ337 UT WOS:A1991GJ33700031 ER PT J AU WHITE, RK AF WHITE, RK TI TOXICOLOGY CHEMISTRY - A GUIDE TO TOXIC-SUBSTANCES IN CHEMISTRY - MANAHAN,SE SO RISK ANALYSIS LA English DT Book Review RP WHITE, RK (reprint author), OAK RIDGE NATL LAB,RISK ANAL SECT,CHINN BLDG,MS-6492,OAK RIDGE,TN 37831, USA. NR 1 TC 0 Z9 0 U1 0 U2 3 PU PLENUM PUBL CORP PI NEW YORK PA 233 SPRING ST, NEW YORK, NY 10013 SN 0272-4332 J9 RISK ANAL JI Risk Anal. PD SEP PY 1991 VL 11 IS 3 BP 563 EP 563 PG 1 WC Public, Environmental & Occupational Health; Mathematics, Interdisciplinary Applications; Social Sciences, Mathematical Methods SC Public, Environmental & Occupational Health; Mathematics; Mathematical Methods In Social Sciences GA GJ337 UT WOS:A1991GJ33700032 ER PT J AU WHITE, RK AF WHITE, RK TI BIOLOGIC MARKERS IN REPRODUCTIVE TOXICOLOGY - NATL-RES-COUNCIL-COMM-LIFE-SCI-BOARD-ENVIRONM-STUDIES-TOXICOL-COMM-BIOL- MARKERS-SUBCOMM-REPROD-NEURODEV-TOXICOL SO RISK ANALYSIS LA English DT Book Review RP WHITE, RK (reprint author), OAK RIDGE NATL LAB,RISK ANAL SECT,CHINN BLDG,MS-6492,OAK RIDGE,TN 37831, USA. NR 1 TC 0 Z9 0 U1 0 U2 0 PU PLENUM PUBL CORP PI NEW YORK PA 233 SPRING ST, NEW YORK, NY 10013 SN 0272-4332 J9 RISK ANAL JI Risk Anal. PD SEP PY 1991 VL 11 IS 3 BP 564 EP 564 PG 1 WC Public, Environmental & Occupational Health; Mathematics, Interdisciplinary Applications; Social Sciences, Mathematical Methods SC Public, Environmental & Occupational Health; Mathematics; Mathematical Methods In Social Sciences GA GJ337 UT WOS:A1991GJ33700034 ER PT J AU ALLEN, MJ BALOOCH, M SUBBIAH, S TENCH, RJ SIEKHAUS, W BALHORN, R AF ALLEN, MJ BALOOCH, M SUBBIAH, S TENCH, RJ SIEKHAUS, W BALHORN, R TI SCANNING TUNNELING MICROSCOPE IMAGES OF ADENINE AND THYMINE AT ATOMIC RESOLUTION SO SCANNING MICROSCOPY LA English DT Article DE DNA BASES; ADENINE; THYMINE; PURINES; PYRIMIDINES; SCANNING TUNNELING MICROSCOPY; HEATED GRAPHITE; ADSORBATE EPITAXY; PYROLYTIC GRAPHITE ID NUCLEIC-ACIDS; PROTEIN AB The scanning tunneling microscope has been used to obtain images of DNA that reveal its major and minor grooves and the direction of helical coiling, but sufficient resolution has not yet been achieved to identify its bases. To determine if this technology is capable of identifying individual DNA bases, we have examined the molecular arrangements of adenine and thymine attached to the basal plane of highly oriented pyrolytic graphite. Both molecules form highly organized lattices following deposition on heated graphite. Lattice dimensions, structural periodicities, and the epitaxy of adenine and thymine molecules with respect to the basal plane of graphite have been determined. Images of these molecules at atomic resolution reveal that the aromatic regions are strongly detected in both molecules while the various side-groups are not well-resolved. These studies provide the first evidence that tunneling microscopy can be used to discriminate between purines and pyrimidines. C1 UNIV CALIF LAWRENCE LIVERMORE NATL LAB,DIV BIOMED SCI,L452,LIVERMORE,CA 94550. UNIV CALIF LAWRENCE LIVERMORE NATL LAB,DIV APPL SCI,LIVERMORE,CA 94550. UNIV CALIF LAWRENCE LIVERMORE NATL LAB,DIV CHEM & MAT SCI,LIVERMORE,CA 94550. STANFORD UNIV,MED CTR,SCH MED,DEPT CELL BIOL,BECKMAN LABS STRUCT BIOL,STANFORD,CA 94305. NR 9 TC 50 Z9 51 U1 0 U2 4 PU SCANNING MICROSCOPY INT PI CHICAGO PA PO BOX 66507, AMF O'HARE, CHICAGO, IL 60666 SN 0891-7035 J9 SCANNING MICROSCOPY JI Scanning Microsc. PD SEP PY 1991 VL 5 IS 3 BP 625 EP 630 PG 6 WC Microscopy SC Microscopy GA HH599 UT WOS:A1991HH59900004 PM 1808704 ER PT J AU LEVENSON, LL SWARTZLANDER, AB YAHASHI, A USUI, H YAMADA, I AF LEVENSON, LL SWARTZLANDER, AB YAHASHI, A USUI, H YAMADA, I TI THE MEASUREMENT OF ALUMINUM SURFACE-DIFFUSION ON SI, SIO2, AND SI3N4 BY SCANNING AUGER MICROSCOPY SO SCANNING MICROSCOPY LA English DT Article DE ALUMINUM; SURFACE DIFFUSION ON SI(111); SILICON OXIDE; SILICON NITRIDE; IONIZED CLUSTER BEAM DEPOSITION; PHYSICAL VAPOR DEPOSITION ID CLUSTER BEAM DEPOSITION; MOBILITY; SI(111) AB The diffusion distance of Al atoms on Si(111), SiO2, and Si3N4 substrates has been measured as a function of substrate temperature. These studies were carried out by depositing Al from an effusive source and from an ionized cluster beam source. Both sources were used in the same apparatus at different times. The deposition was carried out. with either a slit mask or a wire mask at the substrate. After the masks were removed, the deposit was examined by optical and electron microscopy, mechanical profilometer, and Auger line scans. The diffusion distance of Al on the substrates was determined from these measurements. The largest diffusion distances measured on all surfaces occurred at a substrate temperature of 200-degrees-C. The maximum diffusion distance at 200-degrees-C is due to a competition between increasing surface mobility and desorption of Al atoms as surface temperature increases. C1 SOLAR ENERGY RES INST, GOLDEN, CO 80401 USA. KYOTO UNIV, ION BEAM ENGN EXPTL LAB, KYOTO 606, JAPAN. RP LEVENSON, LL (reprint author), UNIV COLORADO, DEPT PHYS & ENERGY SCI, COLORADO SPRINGS, CO 80401 USA. RI Usui, Hiroaki/D-3711-2013 OI Usui, Hiroaki/0000-0001-9460-3889 NR 20 TC 1 Z9 1 U1 0 U2 1 PU SCANNING MICROSCOPY INT PI CHICAGO PA PO BOX 66507, AMF O'HARE, CHICAGO, IL 60666 USA SN 0891-7035 J9 SCANNING MICROSCOPY JI Scanning Microsc. PD SEP PY 1991 VL 5 IS 3 BP 679 EP 688 PG 10 WC Microscopy SC Microscopy GA HH599 UT WOS:A1991HH59900010 ER PT J AU GOLDIN, GA SHARP, DH AF GOLDIN, GA SHARP, DH TI ANYONS SO SCIENTIFIC AMERICAN LA English DT Letter C1 RUTGERS STATE UNIV,DEPT PHYS,NEW BRUNSWICK,NJ 08903. UNIV CALIF LOS ALAMOS SCI LAB,DIV THEORET,LOS ALAMOS,NM 87545. RP GOLDIN, GA (reprint author), RUTGERS STATE UNIV,DEPT MATH,NEW BRUNSWICK,NJ 08903, USA. NR 1 TC 0 Z9 0 U1 0 U2 1 PU SCI AMERICAN INC PI NEW YORK PA 415 MADISON AVE, NEW YORK, NY 10017 SN 0036-8733 J9 SCI AM JI Sci.Am. PD SEP PY 1991 VL 265 IS 3 BP 12 EP 12 PG 1 WC Multidisciplinary Sciences SC Science & Technology - Other Topics GA GC200 UT WOS:A1991GC20000004 ER PT J AU CHUMBLEY, LS LAABS, FC AF CHUMBLEY, LS LAABS, FC TI OBSERVATION OF NB FILAMENTS IN CU-NB INSITU COMPOSITES SO SCRIPTA METALLURGICA ET MATERIALIA LA English DT Article ID INTERPHASE BARRIER; STRENGTH C1 AMES LAB,AMES,IA 50011. RP CHUMBLEY, LS (reprint author), IOWA STATE UNIV SCI & TECHNOL,IOWA AGR & HOME ECON EXPT STN,AMES,IA 50011, USA. NR 14 TC 1 Z9 1 U1 1 U2 1 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD, ENGLAND OX5 1GB SN 0956-716X J9 SCRIPTA METALL MATER JI Scr. Metall. Materialia PD SEP PY 1991 VL 25 IS 9 BP 2097 EP 2101 DI 10.1016/0956-716X(91)90281-5 PG 5 WC Materials Science, Multidisciplinary; Metallurgy & Metallurgical Engineering SC Materials Science; Metallurgy & Metallurgical Engineering GA GE197 UT WOS:A1991GE19700020 ER PT J AU NOH, H FLANAGAN, TB GAVRA, Z JOHNSON, JR REILLY, JJ AF NOH, H FLANAGAN, TB GAVRA, Z JOHNSON, JR REILLY, JJ TI THE DISAPPEARANCE OF HYSTERESIS FOR THE HYDRIDE PHASE-TRANSITION IN PALLADIUM-NICKEL ALLOYS SO SCRIPTA METALLURGICA ET MATERIALIA LA English DT Article ID ABSORPTION; HYDROGEN C1 BROOKHAVEN NATL LAB,DEPT APPL SCI,UPTON,NY 11973. RP NOH, H (reprint author), UNIV VERMONT,DEPT CHEM,BURLINGTON,VT 05405, USA. NR 9 TC 16 Z9 16 U1 0 U2 3 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD, ENGLAND OX5 1GB SN 0956-716X J9 SCRIPTA METALL MATER JI Scr. Metall. Materialia PD SEP PY 1991 VL 25 IS 9 BP 2177 EP 2180 DI 10.1016/0956-716X(91)90295-C PG 4 WC Materials Science, Multidisciplinary; Metallurgy & Metallurgical Engineering SC Materials Science; Metallurgy & Metallurgical Engineering GA GE197 UT WOS:A1991GE19700034 ER PT J AU NG, E AF NG, E TI A SCHEME FOR HANDLING RANK-DEFICIENCY IN THE SOLUTION OF SPARSE LINEAR LEAST-SQUARES PROBLEMS SO SIAM JOURNAL ON SCIENTIFIC AND STATISTICAL COMPUTING LA English DT Article DE SPARSE LEAST SQUARES PROBLEMS; SPARSE ORTHOGONAL FACTORIZATION; UPDATING ALGORITHMS; RANK-DEFICIENCY ID ALGORITHM AB Several schemes for computing sparse orthogonal factorizations using static data structures have been proposed recently. One novel feature of some of these schemes is that the data structures are large enough to store both the orthogonal transformations and upper triangular factor explicitly. However, in order to make use of the static storage schemes, the orthogonal factorization has to be computed without column interchanges, which is sufficient when the observation matrix has full rank. When the least squares matrix is rank-deficient, computing the minimum-norm solution to the least squares problem requires the knowledge of the rank of the matrix, which may be difficult to get if the factorization is computed without column pivoting. In this paper an algorithm is developed that makes use of the resulting factorization to solve rank-deficient least squares problems. The new algorithm has three major features. First, it uses the original triangular factor. Second, this factor is not altered. Third, the rank decision is based on the singular value decomposition and not on the diagonal elements of the triangular factor. The techniques used are similar to those employed by Bjorck. RP NG, E (reprint author), OAK RIDGE NATL LAB,MATH SCI SECT,POB 2008,OAK RIDGE,TN 37831, USA. NR 11 TC 4 Z9 4 U1 0 U2 1 PU SIAM PUBLICATIONS PI PHILADELPHIA PA 3600 UNIV CITY SCIENCE CENTER PH#382-9800, PHILADELPHIA, PA 19104-2688 SN 0196-5204 J9 SIAM J SCI STAT COMP PD SEP PY 1991 VL 12 IS 5 BP 1173 EP 1183 DI 10.1137/0912062 PG 11 WC Mathematics, Applied SC Mathematics GA GB898 UT WOS:A1991GB89800010 ER PT J AU HEATH, MT NG, E PEYTON, BW AF HEATH, MT NG, E PEYTON, BW TI PARALLEL ALGORITHMS FOR SPARSE LINEAR-SYSTEMS SO SIAM REVIEW LA English DT Article DE PARALLEL ALGORITHMS; SPARSE LINEAR SYSTEMS; CHOLESKY FACTORIZATION ID LOCAL-MEMORY MULTIPROCESSOR; MINIMUM-DEGREE ALGORITHM; CHOLESKY FACTORIZATION; GAUSSIAN-ELIMINATION; SYMMETRIC-MATRICES; NESTED DISSECTION; SYMBOLIC FACTORIZATION; TRIANGULAR SYSTEMS; SHARED-MEMORY; FILL-IN AB This paper surveys recent progress in the development of parallel algorithms for solving sparse linear systems on computer architectures having multiple processors. Attention is focused on direct methods for solving sparse symmetric positive definite systems, specifically by Cholesky factorization. Recent progress on parallel algorithms is surveyed for all phases of the solution process, including ordering, symbolic factorization, numeric factorization, and triangular solution. C1 OAK RIDGE NATL LAB,MATH SCI SECT,OAK RIDGE,TN 37831. NR 110 TC 90 Z9 90 U1 0 U2 3 PU SIAM PUBLICATIONS PI PHILADELPHIA PA 3600 UNIV CITY SCIENCE CENTER PH#382-9800, PHILADELPHIA, PA 19104-2688 SN 0036-1445 J9 SIAM REV JI SIAM Rev. PD SEP PY 1991 VL 33 IS 3 BP 420 EP 460 DI 10.1137/1033099 PG 41 WC Mathematics, Applied SC Mathematics GA GE704 UT WOS:A1991GE70400004 ER PT J AU ROSENTHAL, JA ROSENTHAL, DH AF ROSENTHAL, JA ROSENTHAL, DH TI LOGIT AND PROBIT MODELS - A JUVENILE JUSTICE PROGRAM-EVALUATION SO SOCIAL WORK RESEARCH & ABSTRACTS LA English DT Article C1 US DOE,OFF ECON ANAL,WASHINGTON,DC. RP ROSENTHAL, JA (reprint author), UNIV OKLAHOMA,SCH SOCIAL WORK,RHYNE HALL,NORMAN,OK 73019, USA. NR 11 TC 3 Z9 3 U1 0 U2 0 PU NATL ASSOC SOCIAL WORKERS PI WASHINGTON PA 750 FIRST ST, NE, STE 700, WASHINGTON, DC 20002-4241 SN 0148-0847 J9 SOC WORK RES ABSTR PD SEP PY 1991 VL 27 IS 3 BP 16 EP 21 PG 6 WC Social Work SC Social Work GA GF463 UT WOS:A1991GF46300003 ER PT J AU PUCK, TT BARTHOLDI, M KRYSTOSEK, A JOHNSON, R HAAG, M AF PUCK, TT BARTHOLDI, M KRYSTOSEK, A JOHNSON, R HAAG, M TI CONFOCAL MICROSCOPY OF GENOME EXPOSURE IN NORMAL, CANCER, AND REVERSE-TRANSFORMED CELLS SO SOMATIC CELL AND MOLECULAR GENETICS LA English DT Article ID EMBRYONAL CARCINOMA-CELLS; CHINESE HAMSTER CELLS; 3-DIMENSIONAL DISTRIBUTION; INTERMEDIATE FILAMENTS; INTERPHASE NUCLEI; CHROMATIN; DIGESTION; CAMP; ORGANIZATION; REGIONS AB Genome exposure studies were carried out on malignant CHO-K1 and C6 rat glioma cells and their respective, phenotypically normal counterparts (reverse-transformed CHO-K1, and both reverse-transformed C6 glioma and normal rat fibroblasts). Cells were subjected to the nick-translation technique previously developed to make visible the exposed (i.e., DNase I-sensitive) nuclear DNA, and examined by both epifluorescence and confocal microscopy. The confocal microscopy, by permitting examination of sections throughout the nucleus, made possible clearer identification of the regions of exposed and sequestered DNA in the cells studied. A peripheral shell of exposed DNA with some discontinuities was displayed in the great majority of the cells with normal phenotype, but in none of the cancer cells. Both types of cells displayed regions of exposed DNA in the nuclear interior, particularly surrounding the nucleoli. In accordance with previous theoretical proposals we postulate: the peripheral nuclear shell of exposed DNA contains differentiation-specific genes that include the specific growth-control genes and that are functional in normal cells but not in cancer; the exposed genes surrounding the nucleoli may represent housekeeping genes active in both normal and cancer cells; and the DNase I-resistant DNA in the interior of the nucleus we postulate to consist for the most part of genes specific to alternative differentiation states and to be sequestered and inactive. Previous differences in evaluation of roles of peripheral and internal DNA sensitivity to DNase I hydrolysis appear to be reconciled by this formulation. Identification of exposed DNA may be useful in cancer diagnosis. C1 UNIV COLORADO,HLTH SCI CTR,DEPT MED & BIOCHEM,DENVER,CO 80262. UNIV COLORADO,HLTH SCI CTR,DEPT BIOPHYS & GENET,DENVER,CO 80262. UNIV COLORADO,CTR CANC,DENVER,CO 80262. UNIV CALIF LOS ALAMOS SCI LAB,DIV LIFE SCI,LOS ALAMOS,NM 87545. RP PUCK, TT (reprint author), ELEANOR ROOSEVELT INST CANC RES,1899 GAYLORD ST,DENVER,CO 80206, USA. NR 29 TC 20 Z9 20 U1 2 U2 2 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 SEP PY 1991 VL 17 IS 5 BP 489 EP 503 DI 10.1007/BF01233173 PG 15 WC Biochemistry & Molecular Biology; Cell Biology; Genetics & Heredity SC Biochemistry & Molecular Biology; Cell Biology; Genetics & Heredity GA GZ551 UT WOS:A1991GZ55100008 PM 1722354 ER PT J AU ALDE, D BINON, F BRICMAN, C BOUTEMEUR, M GOUANERE, M DONSKOV, SV INYAKIN, AV KACHANOV, VA KULIK, AV LANDSBERG, GL LEDNEV, AA KNAPP, EA PEIGNEUX, JP POLOVNIKOV, SA PROKOSHKIN, YD POULET, M SADOVSKII, SA SAMOILENKO, VD SINGOVSKII, AV STROOT, JP SUGONYAEV, VP KHAUSTOV, GV SHAGIN, PM SHTANNIKOV, AV AF ALDE, D BINON, F BRICMAN, C BOUTEMEUR, M GOUANERE, M DONSKOV, SV INYAKIN, AV KACHANOV, VA KULIK, AV LANDSBERG, GL LEDNEV, AA KNAPP, EA PEIGNEUX, JP POLOVNIKOV, SA PROKOSHKIN, YD POULET, M SADOVSKII, SA SAMOILENKO, VD SINGOVSKII, AV STROOT, JP SUGONYAEV, VP KHAUSTOV, GV SHAGIN, PM SHTANNIKOV, AV TI INVESTIGATION OF THE FORMATION MECHANISM OF THE X(1740) MESON SO SOVIET JOURNAL OF NUCLEAR PHYSICS-USSR LA English DT Article ID NARROW MESON; ETA; G(1590); PI AB New data are given on the narrow meson X(1740) which is produced in charge-exchange pi- p scattering at 38 GeV/c and decays into two eta-mesons. Its existence is confirmed, and constraints are obtained on the width and branching ratio of the decay channels eta'eta and pi(0)pi(0). It is demonstrated that the X(1740) meson is produced with an extremely small cross section (1.5 nb) in a pair with a nucleon isobar [in all likelihood, DELTA(1232)]. A similar reaction with a recoil neutron is not observed. The contribution of one-pion exchange to the process of production of the X(1740) meson is strongly suppressed. C1 LAB PARTICLE PHYS,ANNECY,FRANCE. UNIV CALIF LOS ALAMOS SCI LAB,LOS ALAMOS,NM 87544. FREE UNIV BRUSSELS,INST NUCL PHYS,B-1050 BRUSSELS,BELGIUM. CERN,CH-1211 GENEVA 23,SWITZERLAND. RP ALDE, D (reprint author), PROTVINO HIGH ENERGY PHYS INST,PROTVINO,USSR. NR 14 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 0038-5506 J9 SOV J NUCL PHYS+ PD SEP PY 1991 VL 54 IS 3 BP 451 EP 454 PG 4 WC Physics, Nuclear; Physics, Particles & Fields SC Physics GA HB459 UT WOS:A1991HB45900018 ER PT J AU ALDE, D BINON, F BRICMAN, C BOUTEMEUR, M GOUANERE, M DONSKOV, SV INYAKIN, AV KACHANOV, VA KULIK, AV LANDSBERG, GL LEDNEV, AA LISHIN, VA KNAPP, EA PEIGNEUX, JP POLOVNIKOV, SA PROKOSHKIN, YD POULET, M SADOVSKII, SA SAMOILENKO, VD SINGOVSKII, AV STROOT, JP SUGONYAEV, VP KHAUSTOV, GV SHAGIN, PM SHTANNIKOV, AV AF ALDE, D BINON, F BRICMAN, C BOUTEMEUR, M GOUANERE, M DONSKOV, SV INYAKIN, AV KACHANOV, VA KULIK, AV LANDSBERG, GL LEDNEV, AA LISHIN, VA KNAPP, EA PEIGNEUX, JP POLOVNIKOV, SA PROKOSHKIN, YD POULET, M SADOVSKII, SA SAMOILENKO, VD SINGOVSKII, AV STROOT, JP SUGONYAEV, VP KHAUSTOV, GV SHAGIN, PM SHTANNIKOV, AV TI FURTHER INVESTIGATION OF THE X(1910) MESON SO SOVIET JOURNAL OF NUCLEAR PHYSICS-USSR LA English DT Article ID NARROW MESON; PI-P->ETA'ETA-N; DECAYS; MASS AB New data are presented on the eta'eta system produced in the charge-exchange pi- p reaction at momentum 38 GeV/c. The existence of a narrow eta'eta resonance X(1910) is confirmed. A hypothesis is discussed for the quantum numbers J(PC) = 1(-4) (forbidden for a qqBAR meson) for this particle, which explains both the strict constraints obtained for the decay of the X(1910) meson in the channels pi(0)pi(0), eta-eta, and K(s)0K(s)0, and the flat t dependence of the production cross section for the X(1910) meson. C1 LAB PARTICLE PHYS,ANNECY,FRANCE. UNIV CALIF LOS ALAMOS SCI LAB,LOS ALAMOS,NM 87544. FREE UNIV BRUSSELS,INST NUCL PHYS,B-1050 BRUSSELS,BELGIUM. CERN,CH-1211 GENEVA 23,SWITZERLAND. RP ALDE, D (reprint author), PROTVINO HIGH ENERGY PHYS INST,PROTVINO,USSR. NR 20 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 0038-5506 J9 SOV J NUCL PHYS+ PD SEP PY 1991 VL 54 IS 3 BP 455 EP 458 PG 4 WC Physics, Nuclear; Physics, Particles & Fields SC Physics GA HB459 UT WOS:A1991HB45900019 ER PT J AU DUNLAP, DH DUNCAN, RV AF DUNLAP, DH DUNCAN, RV TI MEASUREMENT ACCURACY OF MACROSCOPIC QUANTUM CIRCUITS WITH RF-BIASED JOSEPHSON JUNCTION ARRAYS SO SUPERCONDUCTOR SCIENCE & TECHNOLOGY LA English DT Article ID VOLTAGE STANDARD AB The DC voltage output from a hysteretic Josephson junction which is locked to an AC frequency source differs from the ideal Josephson relation if the junction drives a current about a closed superconducting circuit. The difference in voltage DELTA-V from two hysteretic Josephson junctions driven in series opposition is proportional to the difference in their driving frequencies DELTA-omega if the junctions are each biased to the nth voltage step. It is shown here, however, that DELTA-V is systematically smaller than the voltage difference DELTA-V(o) predicted by the ideal Josephson relation DELTA-V(o) = (nh/2e)DELTA-omega. If the loop inductance approaches zero, the smallest detectable voltage difference DELTA-V(o) between two junctions is limited by the intrinsic Josephson inductance. For arrays of more than one junction, however, DELTA-V(o) remains proportional to the loop inductance. C1 SANDIA NATL LABS,ALBUQUERQUE,NM 87185. RP DUNLAP, DH (reprint author), UNIV NEW MEXICO,DEPT PHYS & ASTRON,ALBUQUERQUE,NM 87131, USA. NR 13 TC 1 Z9 1 U1 0 U2 0 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 SEP PY 1991 VL 4 IS 9 BP 413 EP 415 DI 10.1088/0953-2048/4/9/008 PG 3 WC Physics, Applied; Physics, Condensed Matter SC Physics GA GV522 UT WOS:A1991GV52200007 ER PT J AU HOUSTON, JE AF HOUSTON, JE TI THE PRECURSOR STATE TO DISSOCIATION FOR CO ADSORBED ON THE W(110) SURFACE SO SURFACE SCIENCE LA English DT Article ID SULFUR MODIFIED FE(100); CARBON-MONOXIDE; STRETCHING FREQUENCY; VIBRATIONAL-SPECTRA; LOW COVERAGE; 110 PLANE; CR(110); CHEMISORPTION; ADSORPTION; TUNGSTEN AB Surface vibrational studies using electron energy-loss spectroscopy (EELS) show that a portion of the CO adsorbed on the W(110) surface involves a binding configuration characterized by a low C-O stretching frequency [nu-(C-O)]. This configuration is rapidly poisoned for CO coverages above about 0.50 ML and its disappearance during 250 K annealing indicates that it is a precursor state to CO dissociation. As the low-nu-(C-O) state is poisoned by CO coverages above 0.50 ML, a normal terminally bonded nu-(C-O) value appears and temperature-programmed desorption (TPD) shows an increase in the desorption of molecularly adsorbed CO. Comparison of these results with similar studies on Cr, Fe, and Mo surfaces, along with present measurements of work-function change (DELTA-phi) with CO coverage, indicate that the low nu-(C-O) results from a CO binding state which is tilted away from the surface normal on W(110). RP HOUSTON, JE (reprint author), SANDIA NATL LABS,ALBUQUERQUE,NM 87185, USA. NR 40 TC 26 Z9 26 U1 1 U2 4 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0039-6028 J9 SURF SCI JI Surf. Sci. PD SEP PY 1991 VL 255 IS 3 BP 303 EP 308 DI 10.1016/0039-6028(91)90687-N PG 6 WC Chemistry, Physical; Physics, Condensed Matter SC Chemistry; Physics GA GH124 UT WOS:A1991GH12400019 ER PT J AU PANESSAWARREN, BJ TORTORA, GT STEARS, RL WARREN, JB AF PANESSAWARREN, BJ TORTORA, GT STEARS, RL WARREN, JB TI BIOLOGICAL CALCIUM-ABSORPTION EDGE IMAGING USING MONOCHROMATIC SYNCHROTRON RADIATION SO ULTRAMICROSCOPY LA English DT Article ID X-RAY-MICROANALYSIS; MICROSCOPY; SPORES AB Soft X-ray contact absorption edge images of unfixed, unstained biological specimens were made using monochromatic synchrotron radiation. X-ray contact replicas of unfixed, hydrated biological specimens at the nitrogen absorption edge and above and below the CaL(III) absorption edge were compared to comparative conventional morphological and elemental high-resolution imaging methods (scanning and transmission electron microscopy, TEM-histochemistry and TEM-X-ray microanalysis). Soft X-ray absorption edge images made above the calcium absorption edge clearly revealed morphological detail and identified regions ladened with calcium as verified by TEM histochemistry of identical spores. Similarly, nitrogen absorption edge images identified residual nitrogenous material in the spore resuspension medium, and non-viable spores with nitrogen loss due to protoplast disaggregation. C1 SUNY STONY BROOK,HLTH SCI CTR,DEPT MED TECHNOL CLIN MICROBIOL,STONY BROOK,NY 11794. SUNY STONY BROOK,DEPT CELL & DEV BIOL,STONY BROOK,NY 11794. BROOKHAVEN NATL LAB,DIV INSTRUMENTAT,UPTON,NY 11973. RP PANESSAWARREN, BJ (reprint author), SUNY STONY BROOK,HLTH SCI CTR,DEPT ALLIED HLTH RESOURCES,STONY BROOK,NY 11794, USA. NR 22 TC 7 Z9 7 U1 0 U2 1 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0304-3991 J9 ULTRAMICROSCOPY JI Ultramicroscopy PD SEP PY 1991 VL 36 IS 4 BP 277 EP 296 DI 10.1016/0304-3991(91)90121-L PG 20 WC Microscopy SC Microscopy GA GM685 UT WOS:A1991GM68500002 PM 1755114 ER PT J AU COOPER, LW OLSEN, CR SOLOMON, DK LARSEN, IL COOK, RB GREBMEIER, JM AF COOPER, LW OLSEN, CR SOLOMON, DK LARSEN, IL COOK, RB GREBMEIER, JM TI STABLE ISOTOPES OF OXYGEN AND NATURAL AND FALLOUT RADIONUCLIDES USED FOR TRACING RUNOFF DURING SNOWMELT IN AN ARCTIC WATERSHED SO WATER RESOURCES RESEARCH LA English DT Article ID SEASONALLY FROZEN SOILS; STORM RUNOFF; SEDIMENTS; PB-210; ACCUMULATION; TRACER; MARINE; STREAM; MODEL; BASIN AB Stable isotopes of oxygen, and natural and fallout radionuclides, have been used, respectively, to identify water sources and to quantify watershed fluxes of precipitation-borne solutes and particles that come in contact with tundra vegetation at Imnavait Creek, Alaska (68-degrees 37'N, 149-degrees 17'W). Oxygen 18/oxygen 16 ratios of water in the snowpack, stream, and unfrozen soil during the peak of snowmelt showed that less than approximately 14% of streamwater was derived from sources other than snow. Within a month of snowmelt, O-18/O-16 ratios in the stream indicated that only negligible amounts of water derived from snow remained in the watershed. In contrast to the low degree of mixing between snow and underlying soil water, greater than 90% of the atmospherically derived Be-7 (53-day half-life) that was deposited in the snowpack was adsorbed onto the surface 2-3 cm of frozen organic soils and vegetation. A slightly lower degree of absorption (approximately 2/3) on tundra was observed for atmospherically derived S-35 (87-day half-life) released during snowmelt. These data indicate that atmospherically derived substances in the snowpack are often retained strongly by sorption or chemical interaction with vegetation and soil during snowmelt. This conclusion is also supported by the vegetation and soil inventories of Cs-137 (30.2-year half-life), which are similar to values expected as a result of atmospheric deposition over the past 40 years. C1 UNIV TENNESSEE,DEPT GEOL SCI,KNOXVILLE,TN 37996. RP COOPER, LW (reprint author), OAK RIDGE NATL LAB,DIV ENVIRONM SCI,POB 2008,OAK RIDGE,TN 37831, USA. RI Cooper, Lee/E-5251-2012; Grebmeier, Jacqueline/L-9805-2013; Solomon, Douglas/C-7951-2016; OI Cooper, Lee/0000-0001-7734-8388; Grebmeier, Jacqueline/0000-0001-7624-3568; Solomon, Douglas/0000-0001-6370-7124; Cook, Robert/0000-0001-7393-7302 NR 44 TC 46 Z9 53 U1 2 U2 12 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 SEP PY 1991 VL 27 IS 9 BP 2171 EP 2179 DI 10.1029/91WR01243 PG 9 WC Environmental Sciences; Limnology; Water Resources SC Environmental Sciences & Ecology; Marine & Freshwater Biology; Water Resources GA GD927 UT WOS:A1991GD92700001 ER PT J AU MAHIN, KW WINTERS, W HOLDEN, TM HOSBONS, RR MACEWEN, SR AF MAHIN, KW WINTERS, W HOLDEN, TM HOSBONS, RR MACEWEN, SR TI PREDICTION AND MEASUREMENT OF RESIDUAL ELASTIC STRAIN DISTRIBUTIONS IN GAS TUNGSTEN ARC WELDS SO WELDING JOURNAL LA English DT Article DE ELASTIC STRAIN; EXPERIMENTAL MEASUREMENT; FINITE ELEMENT METHOD; 304L STAINLESS STEEL; RESIDUAL STRESSES; NEUTRON DIFFRACTION; THERMAL MODELING; MECHANICAL MODELING; ENERGY DEPOSITION ID HEAT-SOURCES; METAL AB The residual elastic strain distributions developed in a stationary gas tungsten arc (GTA) weld on 304L stainless steel were determined using experimental measurements and finite element simulation techniques. The problem selected for analysis was a partial penetration stationary GTA weld positioned at the center of a circular specimen. The objective of this work was to determine the accuracy with which weld-induced residual stresses around a GTA weld could be calculated using a numerical model of the welding process. In the experiment, the specimens were instrumented with thermocouples placed on the top and bottom surfaces of the specimen to provide data for verification of the thermal analysis. After welding, the residual elastic strain distributions in the as-welded specimen were measured using neutron diffraction techniques. The numerical analysis of the weld was performed using a fully-coupled thermal-mechanical finite element code, called PASTA2D, in which the equations of motion and heat conduction are solved simultaneously using a Lagrangian formulation. The code allows for heat transfer due to conduction, radiation and surface convection, but models the heat transfer due to convective flows in the molten weld pool region as enhanced conduction. The thermal-mechanical response of the material was calculated using a visco-elasto-plastic constitutive model. This model accounted for both kinematic and isotropic hardening as a function of temperature and strain rate. Although the thermal conduction solution was "tuned" to bring the calculated temperature histories into agreement with the experimental data, no adjustments were made to the mechanical analysis. Accuracy of the strain calculations was assessed by comparing the neutron diffraction data with the computer predictions. Agreement was excellent in both the heat-affected zone and within the as-solidified weld pool. Although the constitutive model assumed isotropic mechanical properties, even in the weld pool region, this assumption proved to have less influence on the residual strain predictions than anticipated. C1 CHALK RIVER NUCL LABS,CHALK RIVER,ONTARIO,CANADA. RP MAHIN, KW (reprint author), SANDIA NATL LABS,LIVERMORE,CA 94550, USA. NR 76 TC 18 Z9 18 U1 0 U2 2 PU AMER WELDING SOC PI MIAMI PA PO BOX 351040, MIAMI, FL 33135 SN 0043-2296 J9 WELD J JI Weld. J. PD SEP PY 1991 VL 70 IS 9 BP S245 EP S260 PG 16 WC Metallurgy & Metallurgical Engineering SC Metallurgy & Metallurgical Engineering GA GD526 UT WOS:A1991GD52600015 ER PT J AU LOVELAND, W SEABORG, G AF LOVELAND, W SEABORG, G TI THE SEARCH FOR THE MISSING ELEMENTS SO NEW SCIENTIST LA English DT Article C1 OREGON STATE UNIV,CHEM,CORVALLIS,OR 97331. RP LOVELAND, W (reprint author), UNIV CALIF BERKELEY LAWRENCE BERKELEY LAB,RES GRP,BERKELEY,CA 94720, USA. NR 1 TC 0 Z9 0 U1 0 U2 0 PU NEW SCIENTIST PUBL EXPEDITING INC PI ELMONT PA 200 MEACHAM AVE, ELMONT, NY 11003 SN 0262-4079 J9 NEW SCI JI New Sci. PD AUG 31 PY 1991 VL 131 IS 1784 BP 29 EP 32 PG 4 WC Multidisciplinary Sciences SC Science & Technology - Other Topics GA GD143 UT WOS:A1991GD14300035 ER PT J AU GROSS, CT SALAMON, H HUNT, AJ MACEY, RI ORME, F QUINTANILHA, AT AF GROSS, CT SALAMON, H HUNT, AJ MACEY, RI ORME, F QUINTANILHA, AT TI HEMOGLOBIN POLYMERIZATION IN SICKLE CELLS STUDIED BY CIRCULAR POLARIZED-LIGHT SCATTERING SO BIOCHIMICA ET BIOPHYSICA ACTA LA English DT Article DE HEMOGLOBIN-S; POLYMERIZATION; LIGHT SCATTERING; SICKLE CELL ID DIFFERENTIAL SCATTERING; RED-CELLS; ERYTHROCYTES; GELATION; DEOXYGENATION; QUANTITATION; TRANSPORT; DISEASE; FIBERS AB We have studied intracellular polymerization of hemoglobin S in suspensions of small populations of sickle cells using circular polarized light scattering. We argue that the preferential scattering of right circular polarized light (as expressed by measurements of the S14 Mueller scattering matrix element) directly reflects the amount of polymer inside cells. This technique has made it possible to investigate the effect of oxygen tension, cell density and osmotic stress on intracellular hemoglobin polymerization. Using S14 to determine hemoglobin polymer, we show that the polymer increases with deoxyhemoglobin concentration, that cells containing higher hemoglobin concentrations show significantly more polymer than cells containing less hemoglobin, and that polymerization occurs in sickle-trait cells in hypertonic solutions as the oxygen tension in the suspension is reduced. We also present kinetic measurements of polymerization, including that induced by osmotic shock. Finally, we demonstrate that the total light scattered (S11 Mueller scattering matrix element) that is routinely measured simultaneously with S14 can be used to estimate the percent of reduced (deoxy) Hb in the sample. These experiments demonstrate the potential of this technique to monitor hemoglobin polymerization simultaneously with oxygen dissociation under a wide variety of physiological conditions. C1 UNIV CALIF BERKELEY, DEPT CELL & MOLEC BIOL, DIV BIOPHYS & CELL PHYSIOL, BERKELEY, CA 94720 USA. UNIV CALIF BERKELEY LAWRENCE BERKELEY LAB, DIV APPL SCI, BERKELEY, CA 94720 USA. UNIV CALIF BERKELEY LAWRENCE BERKELEY LAB, CTR X-RAY OPT, BERKELEY, CA 94720 USA. RI Quintanilha, Alexandre/L-5371-2013 OI Quintanilha, Alexandre/0000-0001-8544-0061 FU NHLBI NIH HHS [HL 20985, HL-37593] NR 32 TC 9 Z9 9 U1 0 U2 5 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0006-3002 J9 BIOCHIM BIOPHYS ACTA JI Biochim. Biophys. Acta PD AUG 30 PY 1991 VL 1079 IS 2 BP 152 EP 160 DI 10.1016/0167-4838(91)90120-O PG 9 WC Biochemistry & Molecular Biology; Biophysics SC Biochemistry & Molecular Biology; Biophysics GA GG966 UT WOS:A1991GG96600005 PM 1911838 ER PT J AU PETERSON, J FEE, JA DAY, EP AF PETERSON, J FEE, JA DAY, EP TI MAGNETIZATION OF MANGANESE SUPEROXIDE-DISMUTASE FROM THERMUS-THERMOPHILUS SO BIOCHIMICA ET BIOPHYSICA ACTA LA English DT Article DE MANGANESE SUPEROXIDE DISMUTASE; EPR; SQUID; (THERMUS-THERMOPHILUS) ID ESCHERICHIA-COLI-B; ELECTRON-PARAMAGNETIC RESONANCE; BACILLUS-STEAROTHERMOPHILUS; STREPTOCOCCUS-MUTANS; CONTAINING ENZYME; ACTIVE-SITES; IRON; COMPLEXES; RECONSTITUTION; PURIFICATION AB The ground state magnetic properties of manganese superoxide dismutase from Thermus thermophilus in its native and reduced forms have been determined using saturation magnetization data. Parallel EPR measurements were used to verify that commonly encountered paramagnetic impurities were at low concentration relative to the metalloprotein. The native enzyme contains high spin Mn(III) (S = 2) with D = +2.44(5) cm-1 and E/D = 0. The reduced enzyme contains high spin Mn(II) (S = 5/2) with D = +0.50(5) cm-1 and E/D = 0.027. These results are in keeping with the suggestions of several previous groups of workers concerning the permissible oxidation and spin states of the manganese, but the zero field splitting parameters are unlike those of known manganese model compounds. In addition, the extinction coefficient for the visible region absorption maximum of the native enzyme and the corresponding difference extinction coefficient (native minus reduced) have been measured using saturation magnetization data to quantitate Mn(III) present. The result, epsilon-480 = 950(80) M-1 cm-1 (DELTA-epsilon-480 = 740(60) M-1 cm-1) agrees with the previously reported value of epsilon-480 = 910 M-1 cm-1 found by total manganese determination (Sato, S. and Nakazawa, K. (1978) J. Biochem. 83, 1165-1171). The wide variation in the reported visible region extinction coefficients of manganese superoxide dismutases from different sources is discussed. C1 UNIV CALIF LOS ALAMOS SCI LAB,LOS ALAMOS,NM 87544. EMORY UNIV,DEPT PHYS,ATLANTA,GA 30322. RP PETERSON, J (reprint author), UNIV ALABAMA,DEPT CHEM,TUSCALOOSA,AL 35487, USA. OI Peterson, James/0000-0002-7300-5887 FU NIGMS NIH HHS [GM-32394] NR 41 TC 10 Z9 10 U1 1 U2 3 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0006-3002 J9 BIOCHIM BIOPHYS ACTA PD AUG 30 PY 1991 VL 1079 IS 2 BP 161 EP 168 DI 10.1016/0167-4838(91)90121-F PG 8 WC Biochemistry & Molecular Biology; Biophysics SC Biochemistry & Molecular Biology; Biophysics GA GG966 UT WOS:A1991GG96600006 PM 1655035 ER PT J AU HEIMANN, PA MEDHURST, LJ SIGGEL, MRF SHIRLEY, DA CHEN, CT MA, Y SETTE, F AF HEIMANN, PA MEDHURST, LJ SIGGEL, MRF SHIRLEY, DA CHEN, CT MA, Y SETTE, F TI ZERO ELECTRON KINETIC-ENERGY PHOTOEMISSION OF CH4 AND CD4 AT THE CARBON K-IONIZATION THRESHOLD SO CHEMICAL PHYSICS LETTERS LA English DT Article ID GROUND-STATE; PHOTOELECTRON SATELLITES; HIGH-RESOLUTION; PHOTOIONIZATION; TRANSITIONS; METHANE; IMPACT; CO AB Zero electron kinetic energy (ZEKE) photoemission was applied to examine the vibrational fine structure in the C 1s core line of methane. The line broadening from the post collision interaction (PCI) could be understood using the threshold lineshape of atomic argon. From a Franck-Condon analysis of the CH4 and CD4 ZEKE spectra, the geometry of core-ionized methane was evaluated. The equilibrium bond length was determined to be contracted by 0.052(7) angstrom from the ground state of methane (1.085 angstrom). Our results agree with the X-ray photoelectron spectroscopy experiment of Gelius, showing in addition that the molecular structure determined from the vibrational structure in core-level photoemission does not depend on the photoelectron kinetic energy. C1 AT&T BELL LABS,MURRAY HILL,NJ 07974. RP HEIMANN, PA (reprint author), UNIV CALIF BERKELEY LAWRENCE BERKELEY LAB,DIV MAT & CHEM SCI,BERKELEY,CA 94720, USA. NR 20 TC 29 Z9 29 U1 0 U2 2 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0009-2614 J9 CHEM PHYS LETT JI Chem. Phys. Lett. PD AUG 30 PY 1991 VL 183 IS 3-4 BP 234 EP 238 DI 10.1016/0009-2614(91)80056-4 PG 5 WC Chemistry, Physical; Physics, Atomic, Molecular & Chemical SC Chemistry; Physics GA GE915 UT WOS:A1991GE91500013 ER PT J AU KANS, JA MORTIMER, RK AF KANS, JA MORTIMER, RK TI NUCLEOTIDE-SEQUENCE OF THE RAD57 GENE OF SACCHAROMYCES-CEREVISIAE SO GENE LA English DT Article DE DNA REPAIR; MEIOSIS; RECOMBINANT DNA; RECOMBINATIONAL REPAIR; X-RAY SENSITIVITY; YEAST ID BINDING; YEAST; MUTANTS AB We have determined the nucleotide (nt) sequence of the RAD57 gene of Saccharomyces cerevisiae. RAD57 contains an open reading frame of 1380 bp. The deduced amino acid sequence of 460 residues contains a potential nt-binding sequence and shows significant similarity to the preliminary sequence of RAD51. C1 UNIV CALIF BERKELEY,DEPT MOLEC & CELL BIOL,102 DONNER LAB,BERKELEY,CA 94720. UNIV CALIF BERKELEY,LAWRENCE BERKELEY LAB,DIV CELL & MOLEC BIOL,BERKELEY,CA 94720. FU NCRR NIH HHS [5 P40 RR04231-02]; NIEHS NIH HHS [ES07075]; NIGMS NIH HHS [GM30990] NR 11 TC 98 Z9 100 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 AUG 30 PY 1991 VL 105 IS 1 BP 139 EP 140 DI 10.1016/0378-1119(91)90527-I PG 2 WC Genetics & Heredity SC Genetics & Heredity GA GN725 UT WOS:A1991GN72500022 PM 1937004 ER PT J AU MEIER, MS FOX, MA MILLER, JR AF MEIER, MS FOX, MA MILLER, JR TI PEPTIDE CONFORMATIONAL DISTRIBUTIONS AS STUDIED BY ELECTRON-TRANSFER KINETICS SO JOURNAL OF ORGANIC CHEMISTRY LA English DT Article ID DISTANCE DEPENDENCE; RADIATION-CHEMISTRY; BRIDGING LIGANDS; ORGANIC AMIDES; RADICAL-ANIONS; FREE-ENERGY; POLYPEPTIDES; RATES; MOLECULES; SOLVENT AB The preparation and electron-transfer (ET) behavior of a homologous series of alanine oligomers bearing naphthoyl groups at the N-termini and biphenylylamide groups at the C-termini is described. Electron pulse radiolysis was used to generate the corresponding radical anions, and the rates of ET were monitored at 700 nm (decay of donor) and at 500 nm (growth of acceptor). Several systems displayed ET decays too fast to measure (k(et) > 10(10)), and in the others multiexponential decay kinetics were observed. The ET decay of dipeptide 3 could be fit to two exponential described by rate constants of 5.2 x 10(8) (22%) and 5.6 x 10(9) s-1 (78%). In the longer peptides, the fit of the rate constants (and their relative contributions to total intensity) becomes less well-defined, suggesting additional conformational diversity. C1 UNIV TEXAS,DEPT CHEM,AUSTIN,TX 78712. ARGONNE NATL LAB,DIV CHEM,ARGONNE,IL 60439. NR 34 TC 13 Z9 13 U1 0 U2 1 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 SN 0022-3263 J9 J ORG CHEM JI J. Org. Chem. PD AUG 30 PY 1991 VL 56 IS 18 BP 5380 EP 5384 DI 10.1021/jo00018a034 PG 5 WC Chemistry, Organic SC Chemistry GA GD346 UT WOS:A1991GD34600034 ER PT J AU SIMPSON, DJ UNKEFER, CJ WHALEY, TW MARRONE, BL AF SIMPSON, DJ UNKEFER, CJ WHALEY, TW MARRONE, BL TI A MECHANISM-BASED FLUOROGENIC PROBE FOR THE CYTOCHROME-P-450 CHOLESTEROL SIDE-CHAIN CLEAVAGE ENZYME SO JOURNAL OF ORGANIC CHEMISTRY LA English DT Article ID MITOCHONDRIAL STEROID-SYNTHESIS; LUTEINIZING-HORMONE; GRANULOSA-CELLS; RAT; STEROIDOGENESIS; KETOCONAZOLE; BINDING; ASSAY AB The rate-limiting step of steroid biosynthesis is the enzymatic conversion of cholesterol to pregnenolone by cytochrome P-450scc (side chain cleavage) located in the inner mitochondrial membrane of all steroid producing cells. We report here the synthesis and application of a fluorogenic probe which is a cholene-based steroid with a fluorogenic moiety (resorufin) strategically located at the site of side chain cleavage. Synthesis of the probe required four steps starting from 3-beta-acetoxy-22,23-bisnor-5-cholenic acid and resorufin. Reaction of the probe with P-450scc yields pregnenolone and the highly fluorescent resorufin, thus providing a sensitive fluorescent signal representative of enzyme activity. The fluorescence quantum yield of this probe is approximately 40-fold lower (phi = 0.006) than resorufin (phi = 0.23) and is essentially nonfluorescent at wavelengths used to excite resorufin. The utility of the probe is demonstrated biochemically by incubation with mitochondria known to contain the P-450scc enzyme, and its specificity for this enzyme is shown by regulation of the enzyme activity with inhibitors and through the use of a nonspecific substrate. C1 UNIV CALIF LOS ALAMOS SCI LAB,DIV LIFE SCI,MAIL STOP M888,LOS ALAMOS,NM 87545. UNIV CALIF LOS ALAMOS SCI LAB,DIV ISOTOPE & NUCL CHEM,LOS ALAMOS,NM 87545. NR 25 TC 21 Z9 21 U1 1 U2 3 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 SN 0022-3263 J9 J ORG CHEM JI J. Org. Chem. PD AUG 30 PY 1991 VL 56 IS 18 BP 5391 EP 5396 DI 10.1021/jo00018a036 PG 6 WC Chemistry, Organic SC Chemistry GA GD346 UT WOS:A1991GD34600036 ER PT J AU YUE, EW GERDES, JM MATHIS, CA AF YUE, EW GERDES, JM MATHIS, CA TI SYNTHESIS OF 2,3-DIMETHOXY-5-IODOBENZOIC ACID SO JOURNAL OF ORGANIC CHEMISTRY LA English DT Article ID POTENTIAL ANTIPSYCHOTIC AGENTS; ANTIDOPAMINERGIC PROPERTIES; IODINATION; EFFICIENT; IODINE C1 UNIV CALIF BERKELEY LAWRENCE BERKELEY LAB,DIV RES MED & RADIAT BIOPHYS,MS 55-121,1 CYCLOTRON RD,BERKELEY,CA 94720. NR 42 TC 21 Z9 22 U1 0 U2 3 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 SN 0022-3263 J9 J ORG CHEM JI J. Org. Chem. PD AUG 30 PY 1991 VL 56 IS 18 BP 5451 EP 5456 DI 10.1021/jo00018a048 PG 6 WC Chemistry, Organic SC Chemistry GA GD346 UT WOS:A1991GD34600048 ER PT J AU KUBAS, GJ AF KUBAS, GJ TI CHEMICAL BONDING OF HYDROGEN MOLECULES TO TRANSITION-METAL COMPLEXES SO JOURNAL OF THE LESS-COMMON METALS LA English DT Article; Proceedings Paper CT INTERNATIONAL SYMP ON METAL-HYDROGEN SYSTEMS, FUNDAMENTALS AND APPLICATIONS CY SEP 02-07, 1990 CL BANFF, CANADA ID IRIDIUM TRIHYDRIDE COMPLEXES; PROTON-EXCHANGE COUPLINGS; R = PH; DIHYDROGEN COMPLEXES; SPECTROSCOPIC CHARACTERIZATION; NICKEL SURFACE; COORDINATION; POLYHYDRIDES; LIGANDS; H-2 AB An overview of the recently discovered binding of molecular hydrogen (H-2) to transition metal complexes is given. Emphasis is placed on the features which distinguish non-classical metal-dihydrogen bonding from classical atomic metal-hydride systems. Crystallographic and spectroscopic data (IR, nuclear magnetic resonance (NMR), inelastic neutron scattering) and theoretical aspects are discussed. The subtle factors which influence cleavage of bound H-2 to hydride are identified, and examples are given demonstrating that a compound containing a dihydrogen "pair" can exist in facile equilibrium with the "isomeric" compound derived from it containing two separated hydrides. Metal-H-2 systems show a uniquely rich dynamic behavior, including rotation of the side-on bonded H-2. The relatively low energy barrier to rotation is studied experimentally by inelastic neutron scattering and theoretically by ab initio methods, in relation to the bonding model for M-H-2. Quantum mechanical tunneling and exchange processes are identified for bound dihydrogen and certain trihydride systems. RP KUBAS, GJ (reprint author), UNIV CALIF LOS ALAMOS SCI LAB,LOS ALAMOS,NM 87545, USA. NR 33 TC 10 Z9 10 U1 0 U2 4 PU ELSEVIER SCIENCE SA LAUSANNE PI LAUSANNE 1 PA PO BOX 564, 1001 LAUSANNE 1, SWITZERLAND SN 0022-5088 J9 J LESS-COMMON MET PD AUG 30 PY 1991 VL 172 BP 475 EP 484 PN B PG 10 WC Chemistry, Physical; Metallurgy & Metallurgical Engineering SC Chemistry; Metallurgy & Metallurgical Engineering GA GH229 UT WOS:A1991GH22900003 ER PT J AU BARNES, R AF BARNES, R TI NMR-STUDIES OF LOCALIZED INTERSTITIAL HYDROGEN MOTION IN THE HCP METALS SC, Y AND LU SO JOURNAL OF THE LESS-COMMON METALS LA English DT Article; Proceedings Paper CT INTERNATIONAL SYMP ON METAL-HYDROGEN SYSTEMS, FUNDAMENTALS AND APPLICATIONS CY SEP 02-07, 1990 CL BANFF, CANADA ID SPIN-LATTICE RELAXATION; NUCLEAR MAGNETIC-RESONANCE; ELECTRONIC-STRUCTURE; DIFFUSION; YTTRIUM; SYSTEMS; DEUTERIUM; SCANDIUM; HYDRIDES; GLASSES AB The hexagonal close packed (h.c.p.) solid solution (alpha) phases of the Sc-H, Y-H and Lu-H systems have been investigated by nuclear magnetic resonance (NMR) methods over the temperature range 10-300 K in which hydrogen pairs are known to form. At low temperatures (10-120 K), localized motion of hydrogen between closely spaced (about 1.35 angstrom) tetrahedral (T) interstitial sites gives rise to a peak in the proton spin-lattice relaxation rate R1 in alpha-ScH(x) and alpha-LuH(x). This peak may be interpreted in terms of classical over-barrier hopping or tunnelling through the barrier between the close sites. The temperature and resonance frequency dependence of the R1 peak in alpha-ScH(x) exhibit characteristics typically found in amorphous and disordered systems, and which have been interpreted in terms of two-level systems (TLS). This leads to the suggestion that pair formation results effectively in a "proton glass". At a resonance frequency of 24 MHz, the proton R1 maximum at about 40 K in alpha-ScH0.11 corresponds to a hydrogen hopping frequency of nu congruent-to 1.5 x 10(8) s-1. This value is approximately two orders of magnitude slower than the minimum rate (about 1.6 x 10(10) s-1) found at about 100 K in recent quasielastic neutron scattering (QENS) measurements on single-crystal alpha-ScH0.16. A hopping rate of the latter magnitude would not be detected by NMR measurements, so that the NMR and QENS measurements see different fast localized hydrogen motions. An interpretation based on recent theoretical work is presented. C1 IOWA STATE UNIV SCI & TECHNOL,AMES,IA 50011. RP BARNES, R (reprint author), US DOE,AMES LAB,AMES,IA 50011, USA. NR 19 TC 13 Z9 13 U1 0 U2 2 PU ELSEVIER SCIENCE SA LAUSANNE PI LAUSANNE 1 PA PO BOX 564, 1001 LAUSANNE 1, SWITZERLAND SN 0022-5088 J9 J LESS-COMMON MET PD AUG 30 PY 1991 VL 172 BP 509 EP 521 PN B PG 13 WC Chemistry, Physical; Metallurgy & Metallurgical Engineering SC Chemistry; Metallurgy & Metallurgical Engineering GA GH229 UT WOS:A1991GH22900006 ER PT J AU HOKE, HC SCHONE, HE SHOLL, CA USHER, SP BARNES, RG TORGESON, DR HEMPELMANN, R STYLES, GA AF HOKE, HC SCHONE, HE SHOLL, CA USHER, SP BARNES, RG TORGESON, DR HEMPELMANN, R STYLES, GA TI NMR-STUDIES OF DIFFUSION ANISOTROPY IN METAL HYDRIDE SINGLE-CRYSTALS SO JOURNAL OF THE LESS-COMMON METALS LA English DT Article ID NUCLEAR MAGNETIC-RESONANCE; TRANSLATIONAL DIFFUSION; SPIN RELAXATION; HYDROGEN; TRANSITION; SCANDIUM; SOLIDS AB We report on a theoretical and experimental study of hydrogen diffusion in single crystals of alpha-ScH0.25 and beta-V2H which was concerned with the anisotropy of the NMR relaxation rate R1. In alpha-ScH0.25 we find appreciable anisotropy at low temperature associated with local one-dimensional motion; theory and experiment agree fairly well on both the magnitude and the angular dependence of the anisotropy. In beta-V2H the calculations made use of jump times obtained from neutron scattering. In this case again experiment and theory agree on shape; here experiment gives a larger magnitude. C1 UNIV NEW ENGLAND, ARMIDALE, NSW 2351, AUSTRALIA. US DOE, AMES LAB, AMES, IA 50011 USA. IOWA STATE UNIV SCI & TECHNOL, DEPT PHYS, AMES, IA 50011 USA. FORSCHUNGSZENTRUM JULICH, INST FESTKORPERFORSCH, W-5170 JULICH 1, GERMANY. UNIV WARWICK, COVENTRY CV4 7AL, W MIDLANDS, ENGLAND. RP HOKE, HC (reprint author), COLL WILLIAM & MARY, WILLIAMSBURG, VA 23185 USA. RI Sholl, Colin/A-2393-2009 NR 12 TC 0 Z9 0 U1 0 U2 1 PU ELSEVIER SCIENCE SA PI LAUSANNE PA PO BOX 564, 1001 LAUSANNE, SWITZERLAND SN 0022-5088 J9 J LESS-COMMON MET PD AUG 30 PY 1991 VL 172 BP 603 EP 610 PG 8 WC Chemistry, Physical; Metallurgy & Metallurgical Engineering SC Chemistry; Metallurgy & Metallurgical Engineering GA GH229 UT WOS:A1991GH22900016 ER PT J AU IBANEZMEIER, R TORGESON, DR BARNES, RG AF IBANEZMEIER, R TORGESON, DR BARNES, RG TI NUCLEAR-MAGNETIC-RESONANCE SURVEY OF HYDROGEN MOTION AND ELECTRONIC-STRUCTURE IN ALPHA-PHASE (NB-MO)-H ALLOYS SO JOURNAL OF THE LESS-COMMON METALS LA English DT Article AB The results of a proton nuclear magnetic resonance (NMR) survey of hydrogen motion and electronic structure in the solid solution (alpha) phase of niobium rich Nb1-yMoyHx alloys are reported (y less-than-or-equal-to 0.2, x less-than-or-equal-to 0.2). Measurements of the temperature dependence of the proton spin-lattice relaxation time T1 over the range 20 less-than-or-equal-to T less-than-or-equal-to 800 K were analyzed to yield values of the activation energy E(a) and jump attempt frequency nu-0 for hydrogen diffusive hopping and of the product T(le) T = C(e) indicative of the electronic density-of-states at the Fermi level, N(E(F)), where T(le) is that contribution to T1. The T1 vs. T behavior shows features characteristic of hydrogen in random alloys, reflecting a distribution of E(a) and nu-0 values. At high temperatures (approximately 500 K), T1 exhibits anomalous behavior, passing through a maximum and decreasing again at higher temperatures in the same manner found in the Nb-H and (Nb-V)-H systems. C1 US DOE,AMES LAB,AMES,IA 50011. IOWA STATE UNIV SCI & TECHNOL,DEPT PHYS,AMES,IA 50011. NR 10 TC 0 Z9 0 U1 0 U2 0 PU ELSEVIER SCIENCE SA LAUSANNE PI LAUSANNE 1 PA PO BOX 564, 1001 LAUSANNE 1, SWITZERLAND SN 0022-5088 J9 J LESS-COMMON MET PD AUG 30 PY 1991 VL 172 BP 649 EP 657 PN B PG 9 WC Chemistry, Physical; Metallurgy & Metallurgical Engineering SC Chemistry; Metallurgy & Metallurgical Engineering GA GH229 UT WOS:A1991GH22900022 ER PT J AU POWELL, GL KIRKPATRICK, JR CONANT, JW AF POWELL, GL KIRKPATRICK, JR CONANT, JW TI SURFACE EFFECTS IN THE REACTION OF H AND D WITH PD MACROSCOPIC MANIFESTATIONS SO JOURNAL OF THE LESS-COMMON METALS LA English DT Article ID SOLUBILITY; DEUTERIUM; SCATTERING; HYDROGEN AB The reaction of hydrogen and deuterium with palladium has been investigated using pressure-composition-temperature (PCT) measurements at very low hydrogen and deuterium concentration in palladium powder having a surface area of 1.03 m2 g-1 to determine the nature of a surface "film" that affects the diffusional uptake of hydrogen by palladium. PCT isotherms measured on the palladium powder indicated the presence of a two-phase region having an equilibrium pressure of less than 0.5 Pa and a stoichiometry of approximately one monolayer at 299 K. At 421 K, the stoichiometry had decreased by half with a twofold increase in the equilibrium pressure. These isotherms are presented in terms of the experimental PCT curves and those calculated for the "surface hydride". The equilibrium pressure for deuterium was lower than that for hydrogen for this "surface hydride", having an Einstein temperature estimated to be 1600 K. C1 MARTIN MARIETTA ENERGY SYST INC,OAK RIDGE GASEOUS DIFFUS PLANT,OAK RIDGE,TN 37831. UNIV CALIF LOS ALAMOS SCI LAB,LOS ALAMOS,NM 87545. RP POWELL, GL (reprint author), MARTIN MARIETTA ENERGY SYST INC,OAK RIDGE Y-12 PLANT,OAK RIDGE,TN 37831, USA. NR 13 TC 6 Z9 6 U1 0 U2 2 PU ELSEVIER SCIENCE SA LAUSANNE PI LAUSANNE 1 PA PO BOX 564, 1001 LAUSANNE 1, SWITZERLAND SN 0022-5088 J9 J LESS-COMMON MET PD AUG 30 PY 1991 VL 172 BP 867 EP 872 PN B PG 6 WC Chemistry, Physical; Metallurgy & Metallurgical Engineering SC Chemistry; Metallurgy & Metallurgical Engineering GA GH229 UT WOS:A1991GH22900049 ER PT J AU PEEBLES, PJE SCHRAMM, DN TURNER, EL KRON, RG AF PEEBLES, PJE SCHRAMM, DN TURNER, EL KRON, RG TI THE CASE FOR THE RELATIVISTIC HOT BIG-BANG COSMOLOGY SO NATURE LA English DT Review ID QUASI-STELLAR OBJECTS; GRAVITATIONAL LENS; GALAXY CLUSTERS; OPTICAL CATALOG; EVOLUTION; REDSHIFT; SYSTEM; MODELS; NUCLEOSYNTHESIS; ABSORPTION AB The relativistic hot Big Bang model for the expanding Universe has yielded a set of interpretations and successful predictions that substantially outnumber the elements used in devising the theory, with no well-established empirical contradictions. It is reasonable to conclude that this standard cosmology has developed into a mature and believable physical model. C1 PRINCETON UNIV, PRINCETON, NJ 08544 USA. UNIV CHICAGO, CHICAGO, IL 60637 USA. FERMI NATL ACCELERATOR LAB, BATAVIA, IL 60510 USA. NATL ASTRON OBSERV, TOKYO 181, JAPAN. RP PEEBLES, PJE (reprint author), INST ADV STUDY, PRINCETON, NJ 08540 USA. RI Turner, Edwin/A-4295-2011 NR 92 TC 100 Z9 100 U1 0 U2 6 PU NATURE PUBLISHING GROUP PI LONDON PA MACMILLAN BUILDING, 4 CRINAN ST, LONDON N1 9XW, ENGLAND SN 0028-0836 EI 1476-4687 J9 NATURE JI Nature PD AUG 29 PY 1991 VL 352 IS 6338 BP 769 EP 776 DI 10.1038/352769a0 PG 8 WC Multidisciplinary Sciences SC Science & Technology - Other Topics GA GC964 UT WOS:A1991GC96400048 ER PT J AU CHASMAN, RR AF CHASMAN, RR TI SUPERDEFORMED AND HYPERDEFORMED BANANA SHAPED NUCLIDES NEAR A = 190 SO PHYSICS LETTERS B LA English DT Article ID ISOMERISM AB The effects of Y3(1)(theta, phi) deformations on the energy surface of nuclides in the A = 190 region has been studied. Many nuclides with superdeformed and hyperdeformed minima have been found. The states associated with these minima are found to be near yrast at I = 40. RP CHASMAN, RR (reprint author), ARGONNE NATL LAB,DIV PHYS,ARGONNE,IL 60439, USA. NR 17 TC 27 Z9 27 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 AUG 29 PY 1991 VL 266 IS 3-4 BP 243 EP 248 DI 10.1016/0370-2693(91)91033-R PG 6 WC Astronomy & Astrophysics; Physics, Nuclear; Physics, Particles & Fields SC Astronomy & Astrophysics; Physics GA GF924 UT WOS:A1991GF92400003 ER PT J AU YAMAGISHI, K AF YAMAGISHI, K TI W-INFINITY ALGEBRA IS ANOMALY-FREE AT C=-2 SO PHYSICS LETTERS B LA English DT Article AB We show that in the BRST analysis of the W triple-overdot infinity algebra the BRST charge is nilpotent at the central charge c = -2. RP YAMAGISHI, K (reprint author), UNIV CALIF LAWRENCE LIVERMORE NATL LAB,L-413,LIVERMORE,CA 94550, USA. NR 12 TC 8 Z9 8 U1 0 U2 0 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0370-2693 J9 PHYS LETT B JI Phys. Lett. B PD AUG 29 PY 1991 VL 266 IS 3-4 BP 370 EP 374 DI 10.1016/0370-2693(91)91053-X PG 5 WC Astronomy & Astrophysics; Physics, Nuclear; Physics, Particles & Fields SC Astronomy & Astrophysics; Physics GA GF924 UT WOS:A1991GF92400023 ER PT J AU HILL, CT AF HILL, CT TI TOPCOLOR - TOP QUARK CONDENSATION IN A GAUGE EXTENSION OF THE STANDARD MODEL SO PHYSICS LETTERS B LA English DT Article ID DYNAMIC SYMMETRY-BREAKING; GROUP FIXED-POINTS; MASS; BOSONS; SCALES AB We describe a color embedding, SU (3)c --> SU (3)1 x SU (3)2, that is designed to break electroweak symmetries through top quark condensation. The minimal scheme of Bardeen, Hill and Lindner can be recovered by taking the scale of embedding large and fine-tuning the ratio of coupling constants. Models of this kind allow computation of the strength of higher dimension operators which are found to be small. Perhaps fine-tuning can ultimately be avoided in this scheme. RP HILL, CT (reprint author), FERMI NATL ACCELERATOR LAB,POB 500,BATAVIA,IL 60510, USA. NR 20 TC 425 Z9 426 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 AUG 29 PY 1991 VL 266 IS 3-4 BP 419 EP 424 DI 10.1016/0370-2693(91)91061-Y PG 6 WC Astronomy & Astrophysics; Physics, Nuclear; Physics, Particles & Fields SC Astronomy & Astrophysics; Physics GA GF924 UT WOS:A1991GF92400031 ER PT J AU DIXON, LJ NIR, Y AF DIXON, LJ NIR, Y TI COSMOLOGICAL AND ASTROPHYSICAL CONSTRAINTS ON A PSEUDO-DIRAC TAU NEUTRINO SO PHYSICS LETTERS B LA English DT Article ID 17-KEV NEUTRINO; BETA-SPECTRUM; SEE-SAW; BOUNDS; NUCLEOSYNTHESIS; SN1987A; SO(10); DECAY AB Recent experiments suggest that nu-tau may be a pseudo-Dirac neutrino with m-nu-tau almost-equal-to 17 keV. If such a neutrino is to be consistent with constraints from nucleosynthesis, then the mass difference between its two Majorana components should be extremely small. If it is small enough because of see-saw suppression then, in the absence of fine-tuning or additional symmetries, one needs to give up the MSW solution for the solar neutrino problem and the singlet majoron solution for the energy density problem. Thus, additional symmetries that can make nu-tau an almost exact Dirac neutrino should be sought. Also, the distance required for nu-tau to oscillate into its sterile Dirac partner becomes unobservably large. C1 WEIZMANN INST SCI,DEPT PHYS,IL-76100 REHOVOT,ISRAEL. RP DIXON, LJ (reprint author), STANFORD UNIV,STANFORD LINEAR ACCELERATOR CTR,STANFORD,CA 94309, USA. NR 40 TC 5 Z9 5 U1 0 U2 0 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0370-2693 J9 PHYS LETT B JI Phys. Lett. B PD AUG 29 PY 1991 VL 266 IS 3-4 BP 425 EP 430 DI 10.1016/0370-2693(91)91062-Z PG 6 WC Astronomy & Astrophysics; Physics, Nuclear; Physics, Particles & Fields SC Astronomy & Astrophysics; Physics GA GF924 UT WOS:A1991GF92400032 ER PT J AU BOTERO, J MACEK, JH AF BOTERO, J MACEK, JH TI COULOMB BORN APPROXIMATION FOR ELECTRON-SCATTERING FROM NEUTRAL ATOMS - APPLICATION TO ELECTRON-IMPACT IONIZATION OF HELIUM IN COPLANAR SYMMETRICAL GEOMETRY SO JOURNAL OF PHYSICS B-ATOMIC MOLECULAR AND OPTICAL PHYSICS LA English DT Letter ID DIFFERENTIAL CROSS-SECTIONS AB A new perturbation series in which the electron-electron interaction is treated perturbatively is used to compute (e, 2e) cross sections for helium in coplanar symmetric geometry at energies of 100 and 200 eV. The perturbation theory is written such that the slow decrease of the Coulomb potential in which the incoming and scattered particles move becomes irrelevant, and so do the asymptotic conditions of the zero-order wavefunctions. We compute the triple differential cross section using Coulomb waves with an effective charge for the incoming, scattered and ejected electrons and find very good agreement with experiment and with previous calculations, especially in that there is a double peak in the cross section, with a deep dip at an angle close to 90-degrees. C1 OAK RIDGE NATL LAB,OAK RIDGE,TN 37831. RP BOTERO, J (reprint author), UNIV TENNESSEE,DEPT PHYS & ASTRON,KNOXVILLE,TN 37996, USA. NR 18 TC 31 Z9 32 U1 0 U2 0 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 AUG 28 PY 1991 VL 24 IS 16 BP L405 EP L411 DI 10.1088/0953-4075/24/16/006 PG 7 WC Optics; Physics, Atomic, Molecular & Chemical SC Optics; Physics GA GE061 UT WOS:A1991GE06100006 ER PT J AU RENNER, MW FURENLID, LR BARKIGIA, KM FORMAN, A SHIM, HK SIMPSON, DJ SMITH, KM FAJER, J AF RENNER, MW FURENLID, LR BARKIGIA, KM FORMAN, A SHIM, HK SIMPSON, DJ SMITH, KM FAJER, J TI MODELS OF FACTOR-430 - STRUCTURAL AND SPECTROSCOPIC STUDIES OF NI(II) AND NI(I) HYDROPORPHYRINS SO JOURNAL OF THE AMERICAN CHEMICAL SOCIETY LA English DT Article ID COENZYME-M-REDUCTASE; PI-CATION RADICALS; NICKEL TETRAPYRROLE COFACTOR-F430; TRANSITION-METAL COMPLEXES; ELECTRON-SPIN RESONANCE; F430 PENTAMETHYL ESTER; METHANOBACTERIUM-THERMOAUTOTROPHICUM; CARBON-DIOXIDE; METHANOGENIC BACTERIA; SULFITE REDUCTASES AB The reductive chemistry of a series of progressively more saturated Ni(II) porphyrins, derived from anhydromesorhodochlorin XV methyl ester, has been examined as models of F430. Cyclic voltammetry, spectroelectrochemistry, electron paramagnetic resonance, and X-ray absorption studies are used to characterize the parent compounds and their reduction products. Within the Ni(II) porphyrin, chlorin, isobacteriochlorin (iBC), and hexa- and octahydro porphyrin series, only the iBCs are reduced to Ni(I). The other compounds yield pi-anion radicals or pi-radicals with some metal character. The structure of one of the iBCs in the series has been determined by single-crystal X-ray diffraction and used to validate EXAFS results. Crystallographic data for Ni(II) anhydromesorhodoisobacteriochlorin methyl ester with rings C and D reduced, 3, are the following: space group P2(1), a = 13.688 (1) angstrom, b = 8.124 (1) angstrom, c = 14.178 (1) angstrom, beta = 111.83 (1)degrees, V = 1463.6 angstrom3, and Z = 2. The structure was refined against 1226 data points to R(F) = 0.058 and R(wF) = 0.056. Saturation of the macrocycles affects their electronic configurations as evidenced by changes in redox and optical properties as well as sites of reduction. In addition, structural factors emerge as significant determinants of the chemistry of the Ni compounds. Their ability to form Ni(I) or hexacoordinate high-spin Ni(II) requires that the macrocycles be flexible enough to accommodate the conformational changes that accompany reduction to Ni(I) or axial ligation of square-planar Ni(II). Thus, interdependent electronic and structural factors control the reactivity of the models considered here and, by analogy, that of F430 as well. C1 BROOKHAVEN NATL LAB,DEPT APPL SCI,UPTON,NY 11973. UNIV CALIF DAVIS,DEPT CHEM,DAVIS,CA 95616. RI Smith, Kevin/G-1453-2011 OI Smith, Kevin/0000-0002-6736-4779 NR 81 TC 87 Z9 87 U1 0 U2 10 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 AUG 28 PY 1991 VL 113 IS 18 BP 6891 EP 6898 DI 10.1021/ja00018a027 PG 8 WC Chemistry, Multidisciplinary SC Chemistry GA GD306 UT WOS:A1991GD30600027 ER PT J AU ZHOU, JS KOSTIC, NM AF ZHOU, JS KOSTIC, NM TI REACTIONS BETWEEN CYTOCHROME-C AND PLASTOCYANIN INDICATE THAT CHOICE OF DOCKING SITES ON PROTEIN SURFACES MAY DEPEND ON THERMODYNAMIC DRIVING FORCE FOR ELECTRON-TRANSFER SO JOURNAL OF THE AMERICAN CHEMICAL SOCIETY LA English DT Note ID IONIC-STRENGTH DEPENDENCE; BLUE COPPER PROTEINS; SPINACH PLASTOCYANIN; DIPOLE-MOMENT; CHEMICAL MODIFICATION; METALLOCYTOCHROMES-C; EMISSION-SPECTRA; TRANSFER COMPLEX; PEROXIDASE; NMR C1 IOWA STATE UNIV SCI & TECHNOL,US DOE,AMES LAB,AMES,IA 50011. IOWA STATE UNIV SCI & TECHNOL,DEPT CHEM,AMES,IA 50011. NR 42 TC 34 Z9 34 U1 0 U2 0 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 AUG 28 PY 1991 VL 113 IS 18 BP 7040 EP 7042 DI 10.1021/ja00018a055 PG 3 WC Chemistry, Multidisciplinary SC Chemistry GA GD306 UT WOS:A1991GD30600055 ER PT J AU CRUMBAKER, TE HAFICH, MJ ROBINSON, GY JONES, KM ALJASSIM, MM DAVIS, A LORENZO, JP AF CRUMBAKER, TE HAFICH, MJ ROBINSON, GY JONES, KM ALJASSIM, MM DAVIS, A LORENZO, JP TI THE INFLUENCE OF DISLOCATION DENSITY ON ELECTRON-MOBILITY IN INP FILMS ON SI SO APPLIED PHYSICS LETTERS LA English DT Article ID MOLECULAR-BEAM EPITAXY; HETEROEPITAXIAL GROWTH; REDUCTION AB The average electron mobility and dislocation density have been measured as functions of the film thickness in InP films grown on Si substrates by gas-source molecular beam epitaxy. In a region extending about 2-mu-m from the Si interface, the density of dislocations was found to be very high and clustering of dislocations was observed by transmission electron microscopy. The corresponding mobility was very small. Beyond 2-mu-m, clustering was not observed, the density of dislocations decreased, and the average mobility increased with increasing film thickness. Thus, the threading dislocations created by the large InP/Si lattice mismatch can significantly degrade the free carrier mobility of the InP film. C1 SOLAR ENERGY RES INST,GOLDEN,CO 80401. USAF,ROME LAB,BEDFORD,MA 01731. COLORADO STATE UNIV,CTR OPTOELECTR COMP SYST,FT COLLINS,CO 80523. RP CRUMBAKER, TE (reprint author), COLORADO STATE UNIV,DEPT ELECT ENGN,FT COLLINS,CO 80523, USA. NR 11 TC 10 Z9 10 U1 0 U2 1 PU AMER INST PHYSICS PI WOODBURY PA CIRCULATION FULFILLMENT DIV, 500 SUNNYSIDE BLVD, WOODBURY, NY 11797-2999 SN 0003-6951 J9 APPL PHYS LETT JI Appl. Phys. Lett. PD AUG 26 PY 1991 VL 59 IS 9 BP 1090 EP 1092 DI 10.1063/1.106353 PG 3 WC Physics, Applied SC Physics GA GC329 UT WOS:A1991GC32900030 ER PT J AU ZHAO, YJ CHU, WK CHRISTEN, DK JONES, EC DAVIS, MF WOLFE, JC DESHMUKH, SC ECONOMOU, DJ AF ZHAO, YJ CHU, WK CHRISTEN, DK JONES, EC DAVIS, MF WOLFE, JC DESHMUKH, SC ECONOMOU, DJ TI LINEWIDTH DEPENDENCE OF CRITICAL CURRENT-DENSITY IN Y1BA2CU3O7 THIN-FILM MICROBRIDGES SO APPLIED PHYSICS LETTERS LA English DT Article ID YBA2CU3O7-DELTA AB A study of the dependence of the transport critical current density (J(c)) on the width of Y1Ba2Cu3O7 thin-film microbridges with widths down to 2-mu-m has been made. No evidence of edge pinning, which leads to larger J(c)'s in narrower microbridges, was found. Due to the limitation in resolution of photolithography encountered in common usage, a tapered or radiation damaged edge was always present, which may have introduced a significant error in the cross section and hence in the estimation of J(c). By normalizing the critical current (I(c)) to the room-temperature resistance of the microbridge, we can eliminate this mask-defined cross-sectional error. C1 UNIV HOUSTON,TEXAS CTR SUPERCONDUCTIV,HOUSTON,TX 77204. OAK RIDGE NATL LAB,DIV SOLID STATE,OAK RIDGE,TN 37831. RP ZHAO, YJ (reprint author), UNIV HOUSTON,DEPT PHYS,HOUSTON,TX 77204, USA. NR 5 TC 5 Z9 5 U1 1 U2 3 PU AMER INST PHYSICS PI WOODBURY PA CIRCULATION FULFILLMENT DIV, 500 SUNNYSIDE BLVD, WOODBURY, NY 11797-2999 SN 0003-6951 J9 APPL PHYS LETT JI Appl. Phys. Lett. PD AUG 26 PY 1991 VL 59 IS 9 BP 1129 EP 1131 DI 10.1063/1.106366 PG 3 WC Physics, Applied SC Physics GA GC329 UT WOS:A1991GC32900043 ER PT J AU WEINBERGER, BR LYNDS, L HULL, JR BALACHANDRAN, U AF WEINBERGER, BR LYNDS, L HULL, JR BALACHANDRAN, U TI LOW FRICTION IN HIGH-TEMPERATURE SUPERCONDUCTOR BEARINGS SO APPLIED PHYSICS LETTERS LA English DT Article ID MAGNETIC STIFFNESS; LEVITATION FORCES; CERAMICS AB A study of drag in rotating permanent magnet/high temperature superconductor magnetic bearings is reported. The effects of magnet asymmetry, atmospheric resistance, and eddy currents are discussed. One of the bearings achieved a rotational speed of 200 000 RPM and a low speed coefficient of friction of 8.1 X 10(-6), values that have technological significance for flywheel energy storage. C1 ARGONNE NATL LAB,DIV MAT COMPONENT & TECHNOL,ARGONNE,IL 60439. RP WEINBERGER, BR (reprint author), UNITED TECHNOL RES CTR,E HARTFORD,CT 06108, USA. NR 14 TC 55 Z9 57 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 AUG 26 PY 1991 VL 59 IS 9 BP 1132 EP 1134 DI 10.1063/1.106367 PG 3 WC Physics, Applied SC Physics GA GC329 UT WOS:A1991GC32900044 ER PT J AU WEINBERG, AM AF WEINBERG, AM TI ORIGINS OF SCIENCE AND TRANS-SCIENCE - A CITATION-CLASSIC COMMENTARY ON SCIENCE AND TRANS-SCIENCE BY WEINBERG,A.M. SO CURRENT CONTENTS/SOCIAL & BEHAVIORAL SCIENCES LA English DT Article RP WEINBERG, AM (reprint author), OAK RIDGE ASSOCIATED UNIV,DIV MED SCI,OAK RIDGE,TN 37831, USA. NR 5 TC 0 Z9 0 U1 0 U2 2 PU INST SCI INFORM INC PI PHILADELPHIA PA 3501 MARKET ST, PHILADELPHIA, PA 19104 SN 0092-6361 J9 CC/SOC BEHAV SCI PD AUG 26 PY 1991 IS 34 BP 10 EP 10 PG 1 WC Multidisciplinary Sciences; Social Sciences, Interdisciplinary SC Science & Technology - Other Topics; Social Sciences - Other Topics GA GA099 UT WOS:A1991GA09900001 ER PT J AU MYERS, WD SWIATECKI, WJ AF MYERS, WD SWIATECKI, WJ TI DROPLET-MODEL ELECTRIC-DIPOLE MOMENTS SO NUCLEAR PHYSICS A LA English DT Article AB Denisov's recent criticism of the droplet-model formula for the dipole moment of a deformed nucleus as derived by Dorso et al., is shown to be invalid. This helps to clarify the relation of theory to the measured dipole moments, as discussed in the review article by Aberg et al. RP MYERS, WD (reprint author), UNIV CALIF BERKELEY LAWRENCE BERKELEY LAB,DIV NUCL SCI,1 CYCLOTRON RD,BERKELEY,CA 94720, USA. NR 6 TC 12 Z9 12 U1 0 U2 1 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0375-9474 J9 NUCL PHYS A JI Nucl. Phys. A PD AUG 26 PY 1991 VL 531 IS 1 BP 93 EP 96 DI 10.1016/0375-9474(91)90570-V PG 4 WC Physics, Nuclear SC Physics GA GE850 UT WOS:A1991GE85000006 ER PT J AU GOLDEN, M RANDALL, L AF GOLDEN, M RANDALL, L TI RADIATIVE-CORRECTIONS TO ELECTROWEAK PARAMETERS IN TECHNICOLOR THEORIES SO NUCLEAR PHYSICS B LA English DT Article ID SYMMETRY-BREAKING; WEAK INTERACTIONS; ISOSPIN BREAKING AB In models in which technicolor induces electroweak symmetry breaking, the relations between electroweak parameters will differ from those of the standard model. Even with the most conservative assumption that the only custodial SU(2) violating parameters are those in the standard model, there can be measurable corrections to standard model predictions. We present an effective field theory useful for calculating corrections to electroweak parameters. We then focus on technicolor models, for which we construct the low-energy effective theory and calculate the correction to the W-mass from the pseudo-goldstone boson states. C1 UNIV CALIF BERKELEY LAWRENCE BERKELEY LAB,BERKELEY,CA 94720. RP GOLDEN, M (reprint author), FERMI NATL ACCELERATOR LAB,POB 500,BATAVIA,IL 60510, USA. NR 34 TC 292 Z9 292 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 AUG 26 PY 1991 VL 361 IS 1 BP 3 EP 23 DI 10.1016/0550-3213(91)90614-4 PG 21 WC Physics, Particles & Fields SC Physics GA GA520 UT WOS:A1991GA52000001 ER PT J AU ALEKSAN, R DUNIETZ, I KAYSER, B LEDIBERDER, F AF ALEKSAN, R DUNIETZ, I KAYSER, B LEDIBERDER, F TI CP-VIOLATION USING NON-CP EIGENSTATE DECAYS OF NEUTRAL B-MESONS SO NUCLEAR PHYSICS B LA English DT Article ID HEAVY MESONS; FORM-FACTORS; SYSTEMS AB Neutral B-meson decays into non-CP eigenstates are considered as a means for observing CP nonconservation. We show that sizeable CP-violating asymmetries and clean measurements of the phases of the CKM matrix elements can be obtained using these decays provided they satisfy some necessary conditions that can be experimentally verified. It is also argued that two meson final states, in which the quark content of one meson is the CP conjugate of the quark content of the second one, do fulfill these requirements and are a particularly fertile and promising ground for studying CP violation. Two interesting examples, B --> rho +/- pi -/+ and B --> a1 +/- pi -/+, are studied in detail. Their reconstruction efficiencies and their backgrounds are discussed for a generic asymmetric B factory detector. It is found that, within this framework, those decay modes can give a better opportunity for observing CP violation and measuring the CKM phases than the B --> pi+pi- decays. C1 STANFORD UNIV,STANFORD LINEAR ACCELERATOR CTR,STANFORD,CA 94309. LAB ACCELERATEUR LINEAIRE,F-91405 ORSAY 05,FRANCE. NATL SCI FDN,DIV PHYS,WASHINGTON,DC 20550. RP ALEKSAN, R (reprint author), CENS,DPHPE,SEPH,F-91190 GIF SUR YVETTE,FRANCE. NR 23 TC 75 Z9 75 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 AUG 26 PY 1991 VL 361 IS 1 BP 141 EP 165 DI 10.1016/0550-3213(91)90619-9 PG 25 WC Physics, Particles & Fields SC Physics GA GA520 UT WOS:A1991GA52000006 ER PT J AU RHIE, SH BENNETT, DP AF RHIE, SH BENNETT, DP TI GLOBAL MONOPOLES DO NOT COLLAPSE SO PHYSICAL REVIEW LETTERS LA English DT Editorial Material RP RHIE, SH (reprint author), UNIV CALIF LAWRENCE LIVERMORE NATL LAB,INST GEOPHYS & PLANETARY PHYS,LIVERMORE,CA 94550, USA. NR 3 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 0031-9007 J9 PHYS REV LETT JI Phys. Rev. Lett. PD AUG 26 PY 1991 VL 67 IS 9 BP 1173 EP 1173 DI 10.1103/PhysRevLett.67.1173 PG 1 WC Physics, Multidisciplinary SC Physics GA GC603 UT WOS:A1991GC60300030 ER PT J AU FOREST, E BENGTSSON, J REUSCH, MF AF FOREST, E BENGTSSON, J REUSCH, MF TI APPLICATION OF THE YOSHIDA-RUTH TECHNIQUES TO IMPLICIT INTEGRATION AND MULTI-MAP EXPLICIT INTEGRATION SO PHYSICS LETTERS A LA English DT Article AB The full power of Yoshida's technique is exploited to produce an arbitrary order implicit symplectic integrator and a multi-map explicit integrator. This implicit integrator uses the repeated action of a characteristic function involving the force term alone. C1 GRUMMAN AEROSP CORP,CORP RES CTR,PRINCETON,NJ 08540. RP FOREST, E (reprint author), UNIV CALIF BERKELEY LAWRENCE BERKELEY LAB,EXPLORATORY STUDIES GRP,BERKELEY,CA 94720, USA. NR 7 TC 20 Z9 20 U1 0 U2 0 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0375-9601 J9 PHYS LETT A JI Phys. Lett. A PD AUG 26 PY 1991 VL 158 IS 3-4 BP 99 EP 101 DI 10.1016/0375-9601(91)90907-P PG 3 WC Physics, Multidisciplinary SC Physics GA GE565 UT WOS:A1991GE56500001 ER PT J AU BISHOP, AR AF BISHOP, AR TI THEORY OF PAIRING IN HTC MATERIALS SO ABSTRACTS OF PAPERS OF THE AMERICAN CHEMICAL SOCIETY LA English DT Meeting Abstract C1 UNIV CALIF LOS ALAMOS SCI LAB,LOS ALAMOS,NM 87545. NR 0 TC 0 Z9 0 U1 0 U2 0 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 SN 0065-7727 J9 ABSTR PAP AM CHEM S JI Abstr. Pap. Am. Chem. Soc. PD AUG 25 PY 1991 VL 202 BP 1 EP PHYS PN 2 PG 0 WC Chemistry, Multidisciplinary SC Chemistry GA HG081 UT WOS:A1991HG08100542 ER PT J AU VORRES, KS WERTZ, D JOSEPH, JT MALHOTRA, VM AF VORRES, KS WERTZ, D JOSEPH, JT MALHOTRA, VM TI MOISTURE REMOVAL FROM AND LIQUEFACTION OF BEULAH ZAP LIGNITE SO ABSTRACTS OF PAPERS OF THE AMERICAN CHEMICAL SOCIETY LA English DT Meeting Abstract C1 AMOCO OIL CO,RES & DEV,NAPERVILLE,IL 60566. ARGONNE NATL LAB,DIV CHEM,ARGONNE,IL 60439. UNIV SO MISSISSIPPI,DEPT CHEM,HATTIESBURG,MS 39406. SO ILLINOIS UNIV,DEPT PHYS,CARBONDALE,IL 62901. NR 0 TC 0 Z9 0 U1 0 U2 0 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 SN 0065-7727 J9 ABSTR PAP AM CHEM S JI Abstr. Pap. Am. Chem. Soc. PD AUG 25 PY 1991 VL 202 BP 1 EP FUEL PN 1 PG 0 WC Chemistry, Multidisciplinary SC Chemistry GA HG080 UT WOS:A1991HG08001784 ER PT J AU MOORE, DS AF MOORE, DS TI COHERENT RAMAN-SPECTROSCOPY OF HIGH-TEMPERATURE DENSE MOLECULAR FLUIDS AND LOW-TEMPERATURE MOLECULAR-SOLIDS SO ABSTRACTS OF PAPERS OF THE AMERICAN CHEMICAL SOCIETY LA English DT Meeting Abstract C1 UNIV CALIF LOS ALAMOS SCI LAB,LOS ALAMOS,NM 87545. NR 0 TC 0 Z9 0 U1 0 U2 0 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 SN 0065-7727 J9 ABSTR PAP AM CHEM S JI Abstr. Pap. Am. Chem. Soc. PD AUG 25 PY 1991 VL 202 BP 2 EP ANYL PN 1 PG 0 WC Chemistry, Multidisciplinary SC Chemistry GA HG080 UT WOS:A1991HG08000371 ER PT J AU NORMAN, EB AF NORMAN, EB TI EVIDENCE FOR A MASSIVE NEUTRINO IN NUCLEAR BETA-DECAY SO ABSTRACTS OF PAPERS OF THE AMERICAN CHEMICAL SOCIETY LA English DT Meeting Abstract C1 UNIV CALIF BERKELEY,LAWRENCE BERKELEY LAB,DIV NUCL SCI,BERKELEY,CA 94720. NR 0 TC 0 Z9 0 U1 0 U2 0 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 SN 0065-7727 J9 ABSTR PAP AM CHEM S JI Abstr. Pap. Am. Chem. Soc. PD AUG 25 PY 1991 VL 202 BP 3 EP NUCL PN 2 PG 0 WC Chemistry, Multidisciplinary SC Chemistry GA HG081 UT WOS:A1991HG08100003 ER PT J AU WALLACE, DWR KEMP, P WIRICK, C AF WALLACE, DWR KEMP, P WIRICK, C TI SEASONAL DISSOLVED-GAS CYCLING IN THE MIDDLE ATLANTIC BIGHT SO ABSTRACTS OF PAPERS OF THE AMERICAN CHEMICAL SOCIETY LA English DT Meeting Abstract C1 BROOKHAVEN NATL LAB,DEPT APPL SCI,UPTON,NY 11973. NR 0 TC 0 Z9 0 U1 0 U2 0 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 SN 0065-7727 J9 ABSTR PAP AM CHEM S JI Abstr. Pap. Am. Chem. Soc. PD AUG 25 PY 1991 VL 202 BP 3 EP GEOC PN 1 PG 0 WC Chemistry, Multidisciplinary SC Chemistry GA HG080 UT WOS:A1991HG08001927 ER PT J AU GINTER, DM BELL, AT AF GINTER, DM BELL, AT TI THE CHEMISTRY OF NAY CRYSTALLIZATION FROM SODIUM-SILICATE SOLUTIONS SO ABSTRACTS OF PAPERS OF THE AMERICAN CHEMICAL SOCIETY LA English DT Meeting Abstract C1 UNIV CALIF BERKELEY,LAWRENCE BERKELEY LAB,CTR ADV MAT,BERKELEY,CA 94720. UNIV CALIF BERKELEY,DEPT CHEM ENGN,BERKELEY,CA 94720. NR 0 TC 0 Z9 0 U1 0 U2 0 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 SN 0065-7727 J9 ABSTR PAP AM CHEM S JI Abstr. Pap. Am. Chem. Soc. PD AUG 25 PY 1991 VL 202 BP 4 EP PETR PN 2 PG 0 WC Chemistry, Multidisciplinary SC Chemistry GA HG081 UT WOS:A1991HG08100395 ER PT J AU NGUYEN, DC COCKROFT, NJ FAULKNER, GE AF NGUYEN, DC COCKROFT, NJ FAULKNER, GE TI PROBING UP-CONVERSION DYNAMICS USING SITE SELECTIVE SPECTROSCOPY SO ABSTRACTS OF PAPERS OF THE AMERICAN CHEMICAL SOCIETY LA English DT Meeting Abstract C1 UNIV CALIF LOS ALAMOS SCI LAB,LOS ALAMOS,NM 87544. NR 0 TC 0 Z9 0 U1 0 U2 0 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 SN 0065-7727 J9 ABSTR PAP AM CHEM S JI Abstr. Pap. Am. Chem. Soc. PD AUG 25 PY 1991 VL 202 BP 4 EP ANYL PN 1 PG 0 WC Chemistry, Multidisciplinary SC Chemistry GA HG080 UT WOS:A1991HG08000373 ER PT J AU MORETTO, LG WOZNIAK, GJ AF MORETTO, LG WOZNIAK, GJ TI STATISTICS AND DYNAMICS IN MULTIFRAGMENTATION SO ABSTRACTS OF PAPERS OF THE AMERICAN CHEMICAL SOCIETY LA English DT Meeting Abstract C1 UNIV CALIF BERKELEY,LAWRENCE BERKELEY LAB,DIV NUCL SCI,BERKELEY,CA 94720. NR 0 TC 0 Z9 0 U1 0 U2 0 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 SN 0065-7727 J9 ABSTR PAP AM CHEM S JI Abstr. Pap. Am. Chem. Soc. PD AUG 25 PY 1991 VL 202 BP 5 EP NUCL PN 2 PG 0 WC Chemistry, Multidisciplinary SC Chemistry GA HG081 UT WOS:A1991HG08100005 ER PT J AU KILLEEN, KP AF KILLEEN, KP TI MOCVD GAS-PHASE CHEMISTRY SO ABSTRACTS OF PAPERS OF THE AMERICAN CHEMICAL SOCIETY LA English DT Meeting Abstract C1 SANDIA NATL LABS,ALBUQUERQUE,NM 87185. NR 0 TC 0 Z9 0 U1 0 U2 0 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 SN 0065-7727 J9 ABSTR PAP AM CHEM S JI Abstr. Pap. Am. Chem. Soc. PD AUG 25 PY 1991 VL 202 BP 6 EP COLL PN 1 PG 0 WC Chemistry, Multidisciplinary SC Chemistry GA HG080 UT WOS:A1991HG08001408 ER EF