FN Thomson Reuters Web of Science™ VR 1.0 PT J AU SHIMAKURA, N KIMURA, M AF SHIMAKURA, N KIMURA, M TI ELECTRON-CAPTURE IN COLLISIONS OF N5+ IONS WITH H-ATOMS FROM THE MEV TO KEV ENERGY REGIONS SO PHYSICAL REVIEW A LA English DT Article ID MULTIPLY CHARGED IONS; CROSS-SECTIONS; MERGED-BEAMS; HYDROGEN; N-5+; O-6+; C-4+; N-2+; N-3+; N3+ AB Quantum-mechanical and semiclassical molecular-orbital expansion methods are employed to investigate a single-electron-capture mechanism in N5+ + H collisions in the energy range from 10 meV/amu to 10 keV/amu. The dominant electron-capture channels in the entire regime are found to be N4+ (4s), N4+ (4p), and to some extent N4+ (4d). The N4+ (4f) channel is found to make small contributions at any energy because of its near diabaticity with respect to the initial channel. Agreement for total and n-shell captures with recent measurements is excellent in the entire energy regime, and agreement for l-shell capture with measurements is reasonable for most cases. Furthermore, several shape resonances due to rovibrational states of the transient quasimolecule are found below 1 eV, and a large, broad structure arising from trajectory effects due to the weak attractive polarization potential is found below 60 meV/amu. The origins of differences between the present results and the measurements and other theoretical calculations are also discussed. C1 ARGONNE NATL LAB,ARGONNE,IL 60439. RICE UNIV,DEPT PHYS,HOUSTON,TX 77251. NR 22 TC 43 Z9 43 U1 0 U2 0 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 1050-2947 J9 PHYS REV A JI Phys. Rev. A PD AUG 1 PY 1991 VL 44 IS 3 BP 1659 EP 1667 DI 10.1103/PhysRevA.44.1659 PG 9 WC Optics; Physics, Atomic, Molecular & Chemical SC Optics; Physics GA GA169 UT WOS:A1991GA16900037 ER PT J AU UNDERWOOD, TA BREINIG, M GAITHER, CC AF UNDERWOOD, TA BREINIG, M GAITHER, CC TI PRODUCTION OF DOUBLY EXCITED PROJECTILE STATES IN COLLISIONS OF 0.1-MEV/U AG4+ IONS WITH HE, H2, AND AR TARGETS SO PHYSICAL REVIEW A LA English DT Article ID MULTIPLY CHARGED IONS; ELECTRON-CAPTURE; DOUBLE IONIZATION; ATOMIC-HYDROGEN; CROSS-SECTIONS; HELIUM-ATOMS; SINGLE; EXCITATION; PROTONS AB In this work, we study the formation of doubly excited projectile states near the double-escape threshold in collisions of 0.1-MeV/u Ag4+ ions with He, H-2, and Ar gas targets under single-collision conditions. We detect projectile states in which one electron occupies a high Rydberg state and a second electron occupies a low-lying continuum state. The cross sections for producing these doubly excited projectile states are on the order of 10(-20) cm2. The production probabilities are measured as a function of the continuum-electron laboratory-frame energy with the detected Rydberg electrons arising from a fixed band of energy levels. The width of the continuum-electron energy distribution measured in coincidence with a Rydberg electron is smaller than the width of the energy distribution measured without the coincidence requirement for H2 and Ar targets but not for He targets. The width of the continuum-electron energy distribution measured in coincidence with a Rydberg electron decreases as the fraction of doubly excited states formed by projectile double excitation and ionization decreases and the fraction formed by double-target-electron capture increases. C1 OAK RIDGE NATL LAB,OAK RIDGE,TN 37831. RP UNDERWOOD, TA (reprint author), UNIV TENNESSEE,DEPT PHYS,KNOXVILLE,TN 37996, USA. NR 26 TC 2 Z9 2 U1 0 U2 0 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 1050-2947 J9 PHYS REV A JI Phys. Rev. A PD AUG 1 PY 1991 VL 44 IS 3 BP 1668 EP 1676 DI 10.1103/PhysRevA.44.1668 PG 9 WC Optics; Physics, Atomic, Molecular & Chemical SC Optics; Physics GA GA169 UT WOS:A1991GA16900038 ER PT J AU HULSKOTTER, HP FEINBERG, B MEYERHOF, WE BELKACEM, A ALONSO, JR BLUMENFELD, L DILLARD, EA GOULD, H GUARDALA, N KREBS, GF MCMAHAN, MA RHOADESBROWN, ME RUDE, BS SCHWEPPE, J SPOONER, DW STREET, K THIEBERGER, P WEGNER, HE AF HULSKOTTER, HP FEINBERG, B MEYERHOF, WE BELKACEM, A ALONSO, JR BLUMENFELD, L DILLARD, EA GOULD, H GUARDALA, N KREBS, GF MCMAHAN, MA RHOADESBROWN, ME RUDE, BS SCHWEPPE, J SPOONER, DW STREET, K THIEBERGER, P WEGNER, HE TI ELECTRON-ELECTRON INTERACTION IN PROJECTILE ELECTRON LOSS SO PHYSICAL REVIEW A LA English DT Article ID VELOCITY ATOMIC-COLLISIONS; RELATIVISTIC HEAVY-IONS; K-SHELL IONIZATION; CHARGED-PARTICLES; IMPACT IONIZATION; HYDROGEN-ATOMS; ENERGY-LOSS; EXCITATION; CAPTURE; HELIUM AB In ion-atom collisions where the projectile is ionized, target electrons act not only coherently by screening the target nucleus but they may also act incoherently by directly ejecting a projectile electron. This electron-electron interaction should be relatively most important for targets that have a low nuclear charge, since the cross section for a neutral target is roughly proportional to Z(t)2+Z(t), where Z(t)2 is the contribution due to the target nucleus and Z(t) comes from the target electrons. In order to investigate the electron-electron interaction, we have measured and calculated cross sections for Li-2+, C5+, and O7+ on H-2 and He, Au52+ on H-2, He, C, and N2, Au75+ on H-2 and N2, U86+ on H-2 and He, and U90+ on H-2. The collision energies range from 0.75 to 405 MeV/nucleon. The calculations have been performed in the plane-wave Born approximation. We demonstrate that for energies where the target electrons have sufficient kinetic energy in the projectile frame to ionize the projectile, the electron-electron interaction can lead to a significant increase in the total electron-loss cross section. C1 STANFORD UNIV,DEPT PHYS,STANFORD,CA 94305. UNIV CALIF BERKELEY LAWRENCE BERKELEY LAB,DIV ACCELERATOR & FUS RES,BERKELEY,CA 94720. UNIV CALIF BERKELEY LAWRENCE BERKELEY LAB,DIV CHEM SCI,BERKELEY,CA 94720. BROOKHAVEN NATL LAB,DEPT ACCELERATOR DEV,UPTON,NY 11973. BERKELEY HIGH SCH,BERKELEY,CA 94703. BROOKHAVEN NATL LAB,DEPT PHYS,UPTON,NY 11973. NR 46 TC 45 Z9 45 U1 1 U2 2 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 1050-2947 J9 PHYS REV A JI Phys. Rev. A PD AUG 1 PY 1991 VL 44 IS 3 BP 1712 EP 1724 DI 10.1103/PhysRevA.44.1712 PG 13 WC Optics; Physics, Atomic, Molecular & Chemical SC Optics; Physics GA GA169 UT WOS:A1991GA16900044 ER PT J AU FLEMMING, MG WU, JZ CALDWELL, CD KRAUSE, MO AF FLEMMING, MG WU, JZ CALDWELL, CD KRAUSE, MO TI PARTIAL CROSS-SECTIONS AND PHOTOELECTRON ANGULAR-DISTRIBUTIONS IN THE REGION OF THE 4S-]5P AND 5S-]6P RESONANCES IN KRYPTON AND XENON SO PHYSICAL REVIEW A LA English DT Article ID QUANTUM-DEFECT THEORY; PHOTOIONIZATION CONTINUUM; BRANCHING RATIOS; MANGANESE VAPOR; XE; KR; SPECTROMETRY; AR; SPECTROSCOPY; IONIZATION AB Using synchrotron radiation and photoelectron spectrometry, we have examined the 4s4p (6)5p resonance region in krypton and the 5s5p (6)6p resonance region in xenon. We have obtained partial and total cross sections, intensity ratios, and photoelectron angular distribution parameters for the energy regions 20.6-21.5 eV in xenon and 24.6-25.3 eV in krypton. We also report Shore parameters for all cross-section data taken. In addition to the anticipated single-electron transition, we clearly resolve features attributable to two-electron transitions in both species. Characteristics of these autoionizing states may differ considerably in the two available exit channels. C1 OAK RIDGE NATL LAB,OAK RIDGE,TN 37831. RP FLEMMING, MG (reprint author), UNIV CENT FLORIDA,DEPT PHYS,ORLANDO,FL 32816, USA. NR 28 TC 22 Z9 22 U1 0 U2 7 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 AUG 1 PY 1991 VL 44 IS 3 BP 1733 EP 1740 DI 10.1103/PhysRevA.44.1733 PG 8 WC Optics; Physics, Atomic, Molecular & Chemical SC Optics; Physics GA GA169 UT WOS:A1991GA16900046 ER PT J AU OREG, J GOLDSTEIN, W MANDELBAUM, P MITNIK, D MEROZ, E SCHWOB, JL SHALOM, AB AF OREG, J GOLDSTEIN, W MANDELBAUM, P MITNIK, D MEROZ, E SCHWOB, JL SHALOM, AB TI DISTORTED-WAVE CALCULATIONS OF THE ELECTRON-IMPACT EXCITATION-AUTOIONIZATION PROCESSED FROM THE GROUND-STATE OF HIGHLY IONIZED GA I-LIKE IONS THROUGH DELTA-N = 1 INNER-SHELL EXCITATIONS SO PHYSICAL REVIEW A LA English DT Article ID IONIZATION AB A systematic investigation of ionization enhancement due to collisional excitation followed by autoionization (EA) is presented for Ga I-like rare-earth elements. Both nuclear charge and temperature dependence are analyzed and compared with direct-impact ionization (DI) rates. Collisional excitation and autoionization rates were calculated in the distorted-wave factorization-interpolation method. DI rates were calculated by a modified plane-wave Born approximation method. The rates for the combined EA process for selected Ga I-like ions from MO XII to Dy XXXVI are presented for the relevant temperature ranges. It is shown that indirect ionization is dominant for Mo through Pr but is reduced gradually with Z and approaches zero at Dy. A density diagnosis is provided by the opening of EA channels that are not active at low densities. C1 HEBREW UNIV JERUSALEM,RACAH INST PHYS,IL-91904 JERUSALEM,ISRAEL. UNIV CALIF BERKELEY,DEPT PHYS,BERKELEY,CA 94720. UNIV CALIF BERKELEY,SPACE SCI LAB,BERKELEY,CA 94720. UNIV CALIF LAWRENCE LIVERMORE NATL LAB,LIVERMORE,CA 94550. NR 9 TC 16 Z9 16 U1 0 U2 3 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 1050-2947 J9 PHYS REV A JI Phys. Rev. A PD AUG 1 PY 1991 VL 44 IS 3 BP 1741 EP 1749 DI 10.1103/PhysRevA.44.1741 PG 9 WC Optics; Physics, Atomic, Molecular & Chemical SC Optics; Physics GA GA169 UT WOS:A1991GA16900047 ER PT J AU OREG, J GOLDSTEIN, WH KLAPISCH, M BARSHALOM, A AF OREG, J GOLDSTEIN, WH KLAPISCH, M BARSHALOM, A TI AUTOIONIZATION AND RADIATIONLESS ELECTRON-CAPTURE IN COMPLEX SPECTRA SO PHYSICAL REVIEW A LA English DT Article ID COLLISION STRENGTHS; IONS; EXCITATION; PLASMA; IONIZATION; PROGRAM; GAIN AB The factorization-interpolation model, developed to compute collisional excitation rate coefficients efficiently in dense plasma, is applied here to autoionization and radiationless electron capture. Results using a parametric atomic central potential and factorization interpolation for autoionization rates and dielectronic recombination rate coefficients in Ne-like Fe are compared to multiconfigurational Dirac-Fock calculations. Agreement is very good. As a further application, we treat the problem of indirect ionization via collisional excitation followed by autoionization in Zn-like Mo. C1 UNIV CALIF LAWRENCE LIVERMORE NATL LAB,LIVERMORE,CA 94550. UNIV CALIF BERKELEY,SPACE SCI LAB,BERKELEY,CA 94720. UNIV CALIF BERKELEY,DEPT PHYS,BERKELEY,CA 94720. NR 26 TC 84 Z9 85 U1 0 U2 3 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 1050-2947 J9 PHYS REV A JI Phys. Rev. A PD AUG 1 PY 1991 VL 44 IS 3 BP 1750 EP 1758 DI 10.1103/PhysRevA.44.1750 PG 9 WC Optics; Physics, Atomic, Molecular & Chemical SC Optics; Physics GA GA169 UT WOS:A1991GA16900048 ER PT J AU BITTER, M HSUAN, H DECAUX, V GREK, B HILL, KW HULSE, R KRUEGEL, LA JOHNSON, D VONGOELER, S ZARNSTORFF, M AF BITTER, M HSUAN, H DECAUX, V GREK, B HILL, KW HULSE, R KRUEGEL, LA JOHNSON, D VONGOELER, S ZARNSTORFF, M TI SATELLITE SPECTRA OF THE K-ALPHA RESONANCE LINE OF HELIUM-LIKE NICKEL, NI27, FROM TOKAMAK-FUSION-TEST REACTOR PLASMAS - COMPARISON BETWEEN THEORY AND EXPERIMENT SO PHYSICAL REVIEW A LA English DT Article ID JET TOKAMAK; TEMPERATURE; TFTR; INTENSITIES; DEPENDENCE; TITANIUM; EMISSION; IMPURITY; RATIOS; IONS AB Satellite spectra of the K-alpha-line of heliumlike nickel, Ni XXVII, recorded from tokamak-fusion-test reactor (TFTR) Ohmic plasmas with well-defined experimental conditions and central electron temperatures in the range 2-5 keV, have been compared with theoretical predictions. The relevant plasma parameters that determine the spectral features, i.e., the electron and ion temperatures, and the relative abundances of Ni XXV, Ni XXVI, and Ni XXVII have been obtained from least-squares fits of synthetic spectra to the experimental data. Both the dielectronic satellites and the satellites which are produced by collisional inner-shell excitation are well described by the theory given by Bombarda et al. [Phys. Rev. A 37, 504 (1988)] and Vainshtein and Safronova (unpublished). The electron-temperature results derived from the fits are in good agreement with electron-temperature measurements from independent diagnostics. However, the values obtained for the relative abundances of Ni XXV, Ni XXVI, and Ni XXVII are larger by factors of 1.3-2 compared to recent coronal-equilibrium predictions of Zastrow, Kallne, and Summers [Phys. Rev. A 41, 1427 (1990)]. Plasma-modeling calculations performed with the multi-ion-species-transport [R. A. Hulse, Nucl. Technol. Fusion 3, 259 (1983)] code show that these deviations can be explained by radial ion transport assuming for the ion-transport diffusion coefficient D values in the range 1-2.5 m2 s-1. However, the observed deviations may be partially ascribed to theoretical uncertainties of the ionization and recombination rate coefficients used for the coronal-equilibrium calculations. Systematic discrepancies are found to exist between the predicted and observed intensity ratios, x/w, y/w, and z/w, of the heliumlike lines w, 1s2 1S0-1s2P 1P1; x, 1s2 1S0-1s2P 3P2; y, 1s2 1S0-1s2P 3P1; and z, 1s2 1S0-1s2s 3S1. C1 UNIV PARIS 06,PHYS ATOM & NUCL LAB,F-75231 PARIS 05,FRANCE. PRINCETON HIGH SCH,PRINCETON,NJ 08540. RP BITTER, M (reprint author), PRINCETON UNIV,PLASMA PHYS LAB,POB 451,PRINCETON,NJ 08543, USA. NR 32 TC 34 Z9 34 U1 0 U2 1 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 1050-2947 J9 PHYS REV A JI Phys. Rev. A PD AUG 1 PY 1991 VL 44 IS 3 BP 1796 EP 1805 DI 10.1103/PhysRevA.44.1796 PG 10 WC Optics; Physics, Atomic, Molecular & Chemical SC Optics; Physics GA GA169 UT WOS:A1991GA16900053 ER PT J AU HUTTON, R BEIERSDORFER, P OSTERHELD, AL MARRS, RE SCHNEIDER, MB AF HUTTON, R BEIERSDORFER, P OSTERHELD, AL MARRS, RE SCHNEIDER, MB TI X-RAY-SPECTRA OF F-LIKE, O-LIKE, AND N-LIKE BARIUM FROM AN ELECTRON-BEAM ION TRAP SO PHYSICAL REVIEW A LA English DT Article ID HIGHLY CHARGED IONS; LAMB SHIFT; TRANSITIONS; SPECTROSCOPY; ATOMS; PLASMAS; URANIUM; LINES AB An electron-beam ion trap has been used to study the spectra of highly ionized barium. Spectra of N-, O-, and F-like barium were produced by 10-keV electron-impact excitation and ionization and were observed using a von Hamos crystal spectrometer. Calibration lines were obtained by injection of Ti, V, Cr, and Zn into the trap and observation of H- and He-like transitions. A number of lines were identified for each of the ionization stages, and their energies were measured with a typical accuracy of about 150 ppm. These measurements have been compared to calculations using a multiconfigurational Dirac-Fock code. Agreement with the data is best for the F-like transitions, and diminishes for transitions in the more highly charged ions. C1 UNIV CALIF LAWRENCE LIVERMORE NATL LAB,DIV HIGH TEMP PHYS,LIVERMORE,CA 94550. NR 35 TC 13 Z9 13 U1 1 U2 2 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 1050-2947 J9 PHYS REV A JI Phys. Rev. A PD AUG 1 PY 1991 VL 44 IS 3 BP 1836 EP 1842 DI 10.1103/PhysRevA.44.1836 PG 7 WC Optics; Physics, Atomic, Molecular & Chemical SC Optics; Physics GA GA169 UT WOS:A1991GA16900057 ER PT J AU GOLDBERG, P MILONNI, PW SUNDARAM, B AF GOLDBERG, P MILONNI, PW SUNDARAM, B TI THEORY OF THE FUNDAMENTAL LASER LINEWIDTH SO PHYSICAL REVIEW A LA English DT Article ID EXCESS SPONTANEOUS EMISSION; HERMITIAN OPTICAL-SYSTEMS; QUANTUM-THEORY; LONGITUDINAL EIGENMODES; SEMICONDUCTOR-LASERS; AMPLIFIERS; OUTPUT; NONORTHOGONALITY; NOISE; FIELD AB The theory of the laser linewidth is formualted to account for arbitrarily large output couplings and spatial hole burning. We show explicitly that the linewidth can be interpreted in terms of either spontaneous-emission noise or the amplification of vacuum field modes leaking into the cavity, depending on the ordering of operators in the correlation function determining the laser spectrum. This allows us to derive the Petermann K factor associated with "excess spontaneous-emission noise" in a physically transparent and mathematically simple way, without the need to introduce adjoint modes of the resonator. It also allows us to straightforwardly include spatial-hole-burning effects, which are found to increase the K factor and the linewidth in high-gain systems appreciably. C1 UNIV CALIF LOS ALAMOS SCI LAB, CTR NONLINEAR STUDIES, LOS ALAMOS, NM 87545 USA. UNIV CALIF LOS ALAMOS SCI LAB, DIV THEORET, LOS ALAMOS, NM 87545 USA. RI Sundaram, Bala/A-6532-2010 OI Sundaram, Bala/0000-0002-1728-704X NR 34 TC 63 Z9 63 U1 1 U2 8 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 AUG 1 PY 1991 VL 44 IS 3 BP 1969 EP 1985 DI 10.1103/PhysRevA.44.1969 PG 17 WC Optics; Physics, Atomic, Molecular & Chemical SC Optics; Physics GA GA169 UT WOS:A1991GA16900070 ER PT J AU BAJIC, SJ COMPTON, RN TANG, X LAMBROPOULOS, P AF BAJIC, SJ COMPTON, RN TANG, X LAMBROPOULOS, P TI RESONANTLY ENHANCED MULTIPHOTON-IONIZATION PHOTOELECTRON-SPECTROSCOPY OF KRYPTON AND XENON - EXPERIMENT AND THEORY SO PHYSICAL REVIEW A LA English DT Article ID FINE-STRUCTURE THRESHOLDS; AUTO-IONIZING STATES; ANGULAR-DISTRIBUTIONS; 2-PHOTON IONIZATION; PHOTO-ELECTRONS; 3-PHOTON EXCITATION; RUBIDIUM ATOMS; QUANTUM BEATS; CESIUM AB Angular distributions for energy-resolved photoemitted electrons from resonantly enhanced multiphoton ionization (REMPI) via the two-photon allowed 6p[j = 1/2]J = 0, 6p[3/2]2, 6p'[1/2]0, 6p'[3/2]2, 7p[1/2]0, 7p[3/2]2, and 7p[5/2]2 states and the three-photon allowed 7s[3/2]1, 8s[3/2]1, 9s[3/2]1, 5d[3/2]1, 5d'[5/2]3, and 5d'[3/2]1 states of xenon and the three-photon allowed 5s[3/2]1, 6s[3/2]1, 4d[3/2]1, 4d[5/2]3, and 4d[7/2]3 states of krypton are reported. In one case, two-photon resonant, three photon ionization [(2 + 1) REMPI] of the 6p'[1/2]0 state of xenon, a dramatic laser-power dependence (power approximately 1.5 x 10(10) to approximately 3 x 10(10) W/cm2), was observed. The measured angular distributions for electron leaving either ion core (2P1/2 or 2P3/2) are compared with those calculated from multichannel quantum-defect theory. Reasonable agreement is obtained in reproducing the general features of the angular distributions for the p and d states in the rare gases. However, discrepancies are observed for some of the s states. Comparison of the measured and calculated branching ratios for leaving either ion core also shows good agreement for the p and d states, but shows that there are inadequacies in the theory for describing the s states. We also report the photoelectron energy and angular distributions for the (4 + 1) REMPI process via the 6p[1/2]0 and 6p[3/2]2 states of xenon. Photoelectrons due to above-threshold ionization, (4 + 2), resonantly enhanced via the four-photon allowed 6p[1/2]0 state, are also observed. C1 UNIV TENNESSEE,KNOXVILLE,TN 37996. UNIV SO CALIF,LOS ANGELES,CA 90089. RP BAJIC, SJ (reprint author), OAK RIDGE NATL LAB,OAK RIDGE,TN 37831, USA. RI Lambropoulos, Peter/H-2431-2011 NR 31 TC 14 Z9 14 U1 1 U2 21 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 AUG 1 PY 1991 VL 44 IS 3 BP 2102 EP 2112 DI 10.1103/PhysRevA.44.2102 PG 11 WC Optics; Physics, Atomic, Molecular & Chemical SC Optics; Physics GA GA169 UT WOS:A1991GA16900084 ER PT J AU SCHMITTRINK, S MUKAMEL, S LEO, K SHAH, J CHEMLA, DS AF SCHMITTRINK, S MUKAMEL, S LEO, K SHAH, J CHEMLA, DS TI STOCHASTIC-THEORY OF TIME-RESOLVED 4-WAVE-MIXING IN INTERACTING MEDIA SO PHYSICAL REVIEW A LA English DT Article ID FEMTOSECOND PHOTON-ECHOES; HEAVY HOLE EXCITONS; QUANTUM-WELL; WANNIER EXCITONS; UNIFIED THEORY; PUMP-PROBE; RELAXATION; MOLECULES; LIGHT; SEMICONDUCTORS AB We study the temporal profile of the time-resolved four-wave-mixing signal in media with strong polarization interactions, assuming a stochastic modulation of the optical-transition frequency. The model is exactly solvable and interpolates smoothly between Lorentzian (fast modulation) and Gaussian (slow modulation) broadening. We show that recently predicted and observed four-wave-mixing signals persist even in the latter limit, albeit with a different temporal profile. C1 UNIV CALIF BERKELEY LAWRENCE BERKELEY LAB,BERKELEY,CA 94720. UNIV CALIF BERKELEY,DEPT PHYS,BERKELEY,CA 94720. UNIV ROCHESTER,DEPT CHEM,ROCHESTER,NY 14627. RP SCHMITTRINK, S (reprint author), AT&T BELL LABS,MURRAY HILL,NJ 07974, USA. NR 38 TC 57 Z9 57 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 AUG 1 PY 1991 VL 44 IS 3 BP 2124 EP 2129 DI 10.1103/PhysRevA.44.2124 PG 6 WC Optics; Physics, Atomic, Molecular & Chemical SC Optics; Physics GA GA169 UT WOS:A1991GA16900086 ER PT J AU BLUNDELL, SA SNYDERMAN, NJ AF BLUNDELL, SA SNYDERMAN, NJ TI BASIS-SET APPROACH TO CALCULATING THE RADIATIVE SELF-ENERGY IN HIGHLY IONIZED ATOMS SO PHYSICAL REVIEW A LA English DT Note ID SHIFT AB We present a complete numerical implementation of an alternative approach for evaluating the electron radiative self-energy in high-Z hydrogenic ions. Using basis-set techniques, we demonstrate that the partial-wave expansion of the most numerically intensive term converges relatively rapidly as approximately 1/L3, making this an attractive calculational approach. Numerical results extrapolated to zero nuclear size are in agreement with Mohr [Ann. Phys. (N.Y.) 88, 26 (1974); 88, 52 (1974); Phys. Rev. Lett. 34, 1050 (1975); Phys. Rev. A 26, 2338 (1982)] for the K and L shells, and with the graphical results of Mohr and Kim (unpublished) for higher excited states. The algorithm is suitable for immediate generalization to non-Coulombic potentials. RP BLUNDELL, SA (reprint author), UNIV CALIF LAWRENCE LIVERMORE NATL LAB,LIVERMORE,CA 94550, USA. NR 21 TC 90 Z9 90 U1 1 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 AUG 1 PY 1991 VL 44 IS 3 BP R1427 EP R1430 PG 4 WC Optics; Physics, Atomic, Molecular & Chemical SC Optics; Physics GA GA169 UT WOS:A1991GA16900001 ER PT J AU KYRALA, GA NICHOLS, TD AF KYRALA, GA NICHOLS, TD TI MEASUREMENT OF ABSOLUTE RATES FOR MULTIPHOTON IONIZATION OF ATOMIC-HYDROGEN AT 248 NM SO PHYSICAL REVIEW A LA English DT Note ID ABOVE-THRESHOLD-IONIZATION; H-ATOM; FIELD; PHOTOIONIZATION; SYSTEM AB We present measurements of absolute rates for multiphoton ionization of the ground state of atomic hydrogen by a linearly polarized, subpicosecond KrF laser at a wavelength of 248 nm. The irradiance was varied from 3 x 10(12) to 2 x 10(14) W/cm2, and three above-threshold-ionization peaks were observed. The measured rate for total electron production was less than that predicted by Floquet theory [S.-I. Chu and J. Cooper, Phys. Rev. A 32, 2769 (1985)] and perturbation calculations [S. V. Khristenko and S. I. Vetchinkin, Opt. Specktrosc. 40, 239 (1976)], but significantly higher than calculated by the Reiss [Phys. Rev. A 22, 1786 (1980)] and Keldysh [Sov. Phys. JETP 20, 1307 (1965)] methods using Volkov final states. RP KYRALA, GA (reprint author), UNIV CALIF LOS ALAMOS SCI LAB,DIV PHYS,LOS ALAMOS,NM 87545, USA. NR 26 TC 18 Z9 18 U1 0 U2 2 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 1050-2947 J9 PHYS REV A JI Phys. Rev. A PD AUG 1 PY 1991 VL 44 IS 3 BP R1450 EP R1453 PG 4 WC Optics; Physics, Atomic, Molecular & Chemical SC Optics; Physics GA GA169 UT WOS:A1991GA16900007 ER PT J AU YANG, B SAEED, M DIMAURO, LF ZAVRIYEV, A BUCKSBAUM, PH AF YANG, B SAEED, M DIMAURO, LF ZAVRIYEV, A BUCKSBAUM, PH TI HIGH-RESOLUTION MULTIPHOTON IONIZATION AND DISSOCIATION OF H2 AND D2 MOLECULES IN INTENSE LASER FIELDS SO PHYSICAL REVIEW A LA English DT Note ID H-2 AB We report on the multiphoton ionization and dissociation of hydrogen and deuterium molecules in intense (8 x 10(11)-4 x 10(13) W/cm2) laser fields. The investigations were performed with the second harmonics of two different laser systems, a 50-ps neodymium-doped yttrium lithium fluoride and a 10-ns neodymium doped yttrium aluminum garnet laser. Measurements included energy-resolved photoelectron and mass spectroscopy. In addition, we report on a measurement of the dynamics of different above-threshold dissociation branching ratios for H-2+ and D2+ over a wide range of laser intensities. Our results support the dressed-molecule picture at least qualitatively, but differences do exist with the quantitative predictions. C1 UNIV MICHIGAN,DEPT PHYS,ANN ARBOR,MI 48109. LOUISIANA STATE UNIV,DEPT PHYS,BATON ROUGE,LA 70803. RP YANG, B (reprint author), BROOKHAVEN NATL LAB,DEPT CHEM,UPTON,NY 11973, USA. NR 12 TC 90 Z9 90 U1 5 U2 17 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 AUG 1 PY 1991 VL 44 IS 3 BP R1458 EP R1461 PG 4 WC Optics; Physics, Atomic, Molecular & Chemical SC Optics; Physics GA GA169 UT WOS:A1991GA16900009 ER PT J AU KEPHART, JO BERMAN, BL PANTELL, RH DATZ, S KLEIN, RK PARK, H AF KEPHART, JO BERMAN, BL PANTELL, RH DATZ, S KLEIN, RK PARK, H TI THERMAL-VIBRATIONAL AMPLITUDES OF SILICON DETERMINED BY CHANNELING-RADIATION MEASUREMENTS SO PHYSICAL REVIEW B LA English DT Article ID PLANAR; ELECTRONS; DEPENDENCE AB We have observed radiation emitted by electrons channeled along the (110) and (100) planes of silicon for four different beam energies ranging from 16.9 to 54.5 MeV. Taking advantage of the great sensitivity of the positions of some of the spectral peaks to the vibrations of the Si nuclei, we have determined the vibrational amplitude at room temperature to be 0.0813 +/- 0.0009 angstrom for the (110) plane and 0.0789 +/- 0.0007 angstrom for the (100) plane. The values obtained from channeling-radiation measurements differ substantially from the value of 0.075 angstrom obtained from x-ray-diffraction measurements, which fail to distinguish between vibrational amplitudes for different planes. For many crystals, electron-channeling-radiation measurements of thermal-vibrational amplitudes may prove to be more accurate than x-ray measurements. C1 GEORGE WASHINGTON UNIV,DEPT PHYS,WASHINGTON,DC 20052. STANFORD UNIV,DEPT ELECT ENGN,STANFORD,CA 94305. OAK RIDGE NATL LAB,DIV PHYS,OAK RIDGE,TN 37831. ADV MICRO DEVICES INC,SUNNYVALE,CA 94088. AT&T BELL LABS,MURRAY HILL,NJ 07974. RP KEPHART, JO (reprint author), IBM CORP,THOMAS J WATSON RES CTR,YORKTOWN HTS,NY 10598, USA. NR 22 TC 13 Z9 13 U1 0 U2 1 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 0163-1829 J9 PHYS REV B JI Phys. Rev. B PD AUG 1 PY 1991 VL 44 IS 5 BP 1992 EP 2002 DI 10.1103/PhysRevB.44.1992 PG 11 WC Physics, Condensed Matter SC Physics GA GA076 UT WOS:A1991GA07600003 ER PT J AU RUBINI, S DIMITROPOULOS, C GOTTHARDT, R BORSA, F AF RUBINI, S DIMITROPOULOS, C GOTTHARDT, R BORSA, F TI MARTENSITIC-TRANSFORMATION IN A CU-ZN-AL ALLOY STUDIED BY CU-63 AND AL-27 NMR SO PHYSICAL REVIEW B LA English DT Article ID STRUCTURAL PHASE-TRANSITIONS; NEUTRON-SCATTERING; PREMARTENSITIC BEHAVIOR; THERMOELASTICITY; PSEUDOELASTICITY; NQR AB Al-27 and Cu-63 line shape, Knight shift, and relaxation rates over a wide range of temperature and external magnetic field are reported for a Cu-Zn-Al alloy displaying a martensitic phase transformation (MPT) at M(S) = 152 K. Changes in line shape, linewidth, and T2(-1) at the MPT are detected for both nuclei, and are found to be consistent with the local atomic rearrangement occurring at the transformation. A double structure for the Al-27 NMR line is observed in a small range of temperature below M(S), and interpreted as the superposition of the signals arising from the two coexisting phases. It is shown that the growth of the martensitic phase during the cooling can be monitored by means of the deconvolution of the Al-27 spectrum into the two components. From the analysis, it is inferred that a sudden formation of extensive regions of martensitic phase occurs at the transition. The Knight shift and the Korringa term (T1T)-1 are slightly different in the two phases, indicating a small increase of the density of s electrons at the Fermi surface at the nuclear sites. The enhancement factors of the susceptibility and of the spin-lattice relaxation rate do not seem to be affected by the MPT but are different when measured at the Al or Cu site, indicating a local nonuniform charge-density distribution in the unit cell. A small enhancement of T1(-1) is observed for both nuclei in the temperature interval in which the growth of the martensite within the austenite is detected. The anomalous contribution to the relaxation is interpreted as due to strong local charge-density fluctuations caused by atomic motion at the interfaces between the two phases. No precursor effects were detected on the NMR parameters above M(S), indicating the absence of static or long-lived microstructures of the product phase and of static short-wavelength modulations of the lattice. C1 ECOLE POLYTECH FED LAUSANNE,INST GEN ATOM,CH-1015 LAUSANNE,SWITZERLAND. UNIV PAVIA,DIPARTMENTO FIS,I-27100 PAVIA,ITALY. IOWA STATE UNIV SCI & TECHNOL,AMES LAB,AMES,IA 50011. IOWA STATE UNIV SCI & TECHNOL,DEPT PHYS,AMES,IA 50011. RP RUBINI, S (reprint author), ECOLE POLYTECH FED LAUSANNE,INST PHYS EXPTL,CH-1015 LAUSANNE,SWITZERLAND. RI Rubini, Silvia/C-8369-2012 OI Rubini, Silvia/0000-0001-5215-2223 NR 45 TC 15 Z9 15 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 AUG 1 PY 1991 VL 44 IS 5 BP 2019 EP 2029 DI 10.1103/PhysRevB.44.2019 PG 11 WC Physics, Condensed Matter SC Physics GA GA076 UT WOS:A1991GA07600005 ER PT J AU LIU, C BADER, SD AF LIU, C BADER, SD TI MORPHOLOGY OF FE/PD(100) FILMS STUDIED USING PHOTOEMISSION FROM PHYSISORBED XE SO PHYSICAL REVIEW B LA English DT Article ID MAGNETIC-ANISOTROPY; XENON ADSORPTION; ADSORBED XENON; SURFACE; METALS; TRANSITION; MONOLAYERS; INTERFACES; PALLADIUM; PD(001) AB The system Fe/Pd(100) exhibits a strong thickness dependence of the Curie temperature T(C), especially in the submonolayer range. Also, the magnetic properties of ultrathin Fe/Pd(100) films depend on the growth temperature. Films grown at 100 K possess easy axes of magnetization that are perpendicular to the film plane for monolayer-range Fe thicknesses, while films grown at 300 K have in-plane easy axes for all thicknesses. In the present study, photoemission (using He I radiation, 21.2 eV) of physisorbed Xe monolayers on Pd(100) and Fe/Pd(100) at 50 K has been used to study the morphology that underlies the magnetic properties. Xe adsorbed on clean Pd(100) shows narrow Xe 5P3/2 and 5p1/2 emission peaks. The peaks broaden and shift toward higher binding energies for adsorption on the Fe/Pd(100) films. In the case of 100-K growth, the peak shift reaches maximum upon the completion of one monolayer of Fe, while for 300-K growth the shifting occurs gradually over several Fe monolayers. No splittings are observed for either the 5p3/2 or 5p/12 emission peak, suggesting the absence of Fe islands on the Pd(100) substrate even in the submonolayer Fe regime, which is consistent with a random-site-occupancy model that has been proposed recently in a theoretical study of the T(C) variation. RP LIU, C (reprint author), ARGONNE NATL LAB,DIV MAT SCI,ARGONNE,IL 60439, USA. RI Bader, Samuel/A-2995-2013 NR 28 TC 31 Z9 31 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 AUG 1 PY 1991 VL 44 IS 5 BP 2205 EP 2208 DI 10.1103/PhysRevB.44.2205 PG 4 WC Physics, Condensed Matter SC Physics GA GA076 UT WOS:A1991GA07600024 ER PT J AU ROTHMAN, SJ ROUTBORT, JL WELP, U BAKER, JE AF ROTHMAN, SJ ROUTBORT, JL WELP, U BAKER, JE TI ANISOTROPY OF OXYGEN TRACER DIFFUSION IN SINGLE-CRYSTAL YBA2CU3O7-DELTA SO PHYSICAL REVIEW B LA English DT Article ID CHEMICAL DIFFUSION; PHASE-DIAGRAM; SUPERCONDUCTOR YBA2CU3O7-DELTA; MONTE-CARLO; TEMPERATURE; TRANSPORT; Y1BA2CU3O7-X; BEHAVIOR; NONSTOICHIOMETRY; BA2YCU3O7-DELTA AB Oxygen tracer diffusion has been measured in single-crystalline YBa2CU3O7-delta from 300 to 650-degrees-C in the c direction, at a few temperatures in the ab plane of twinned crystals, and in the b direction of an untwinned crystal. The diffusion coefficient in the c direction, D(c), is almost-equal-to 10(6) lower than the diffusion coefficient in polycrystals at 400-degrees-C and diffusion in the b direction is at least 100 times faster than diffusion in the a direction at 300-degrees-C. The oxygen diffusion coefficient in polycrystals is, within an experimental uncertainty of a factor of 2, independent of oxygen partial pressure at 400-degrees-C, in agreement with previous results measured at 600-degrees-C. Some suggestions are presented on tbe mechanism of diffusion, the relation of diffusion and internal friction in YBa2CU3O7-delta, and on the meaning of the activation energy. C1 UNIV ILLINOIS,CTR MICROANAL MAT,URBANA,IL 61801. RP ROTHMAN, SJ (reprint author), ARGONNE NATL LAB,DIV MAT SCI,ARGONNE,IL 60439, USA. NR 63 TC 208 Z9 208 U1 8 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 AUG 1 PY 1991 VL 44 IS 5 BP 2326 EP 2331 DI 10.1103/PhysRevB.44.2326 PG 6 WC Physics, Condensed Matter SC Physics GA GA076 UT WOS:A1991GA07600040 ER PT J AU SHARMA, RP REHN, LE BALDO, PM WELP, U FANG, Y AF SHARMA, RP REHN, LE BALDO, PM WELP, U FANG, Y TI ION CHANNELING ALONG THE [301] AND [331] AXES IN YBA2CU3O7-X SO PHYSICAL REVIEW B LA English DT Article ID SUPERCONDUCTING TRANSITION; SINGLE-CRYSTALS; TC; TEMPERATURE; OXYGEN AB In order to characterize more fully the phonon anomaly observed previously across T, in YBa2Cu3O7-x and (Bi1.7Pb0.3)Sr2Ca,Cu2O(x), ion channeling was performed along the [301] and [331] directions in YBa2Cu3O7-x. Because twinning in these crystals occurs via interchange of tbe a and b crystal axes, twins produce no effect on channeling along the [001) axis. However, twinning is a major factor along all other directions. In particular, axial scans along [3011 and [331] directions show a splitting of the channeling dip by 0.96-degrees and 1.92-degrees, respectively. In areas of the specimen in which one twin variant dominates, a single dip is shown to occur along the appropriate [331] axis, but the dip remains split along all [301] directions. Detwinned crystals produced reasonably good single dips along both directions. The observed splitting of the channeling dips is accounted for using a geometrical analysis based upon the known difference in the a and b lattice dimensions. These new results reveal that the c-axis component of the anomalous atomic displacements that occur across T(c) is at most only slightly larger than the component in the a-b plane. The [301] channeling scans also show unambiguously that the Cu atoms participate in the anomalous displacements observed at T(c). RP SHARMA, RP (reprint author), ARGONNE NATL LAB,DIV MAT SCI,ARGONNE,IL 60439, USA. NR 23 TC 6 Z9 6 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 AUG 1 PY 1991 VL 44 IS 5 BP 2334 EP 2340 DI 10.1103/PhysRevB.44.2334 PG 7 WC Physics, Condensed Matter SC Physics GA GA076 UT WOS:A1991GA07600041 ER PT J AU WENTZCOVITCH, RM AF WENTZCOVITCH, RM TI INVARIANT MOLECULAR-DYNAMICS APPROACH TO STRUCTURAL PHASE-TRANSITIONS SO PHYSICAL REVIEW B LA English DT Note ID TEMPERATURE; PRESSURE; SYSTEMS AB Two fictitious Lagrangians to be used in molecular-dynamics simulations with variable cell shape and suitable to study problems like structural phase transitions are introduced. Because they are invariant with respect to the choice of the simulation cell edges and eliminate symmetry breaking associated with the fictitious part of the dynamics, they improve the physical content of numerical simulations that up to now have been done by using Parrinello-Rahman dynamics. RP WENTZCOVITCH, RM (reprint author), BROOKHAVEN NATL LAB,DEPT PHYS,UPTON,NY 11973, USA. RI Wentzcovitch, Renata/J-8768-2015 NR 14 TC 215 Z9 216 U1 7 U2 32 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 AUG 1 PY 1991 VL 44 IS 5 BP 2358 EP 2361 DI 10.1103/PhysRevB.44.2358 PG 4 WC Physics, Condensed Matter SC Physics GA GA076 UT WOS:A1991GA07600045 ER PT J AU CEDER, G MCCORMACK, R DEFONTAINE, D AF CEDER, G MCCORMACK, R DEFONTAINE, D TI TIME-DEPENDENT OXYGEN ORDERING AND ITS EFFECT ON TC IN OFF-STOICHIOMETRIC YBA2CU3OZ SO PHYSICAL REVIEW B LA English DT Note ID PHASE-DIAGRAM; TEMPERATURE; BEHAVIOR AB The increase in T(c) recently observed by Veal et al. and Jorgensen et al. during room-temperature aging of quenched YBa2Cu3Oz samples is explained by studying the microscopic changes that take place in a simulated aging experiment. Monte Carlo simulation shows that the threefold coordinations of oxygen around Cu in the basal plane are converted into twofold and threefold coordinations during room-temperature aging. The hole doping induced by this conversion results in the increase in T(c). Both tetragonal-orthorhombic ordering and additional superstructure ordering are responsible for the observed changes in Cu coordinations. It is shown that aging of samples with high oxygen content will not significantly increase T(c). C1 UNIV CALIF BERKELEY LAWRENCE BERKELEY LAB,BERKELEY,CA 94720. RP CEDER, G (reprint author), UNIV CALIF BERKELEY,DEPT MAT SCI & MINERAL ENGN,BERKELEY,CA 94720, USA. NR 15 TC 65 Z9 65 U1 1 U2 4 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 0163-1829 J9 PHYS REV B JI Phys. Rev. B PD AUG 1 PY 1991 VL 44 IS 5 BP 2377 EP 2380 DI 10.1103/PhysRevB.44.2377 PG 4 WC Physics, Condensed Matter SC Physics GA GA076 UT WOS:A1991GA07600050 ER PT J AU DELEON, JM CONRADSON, SD BATISTIC, I BISHOP, AR AF DELEON, JM CONRADSON, SD BATISTIC, I BISHOP, AR TI CORRELATION BETWEEN AXIAL-OXYGEN ANHARMONICITY AND TC IN YBA2CU3O7 AND RELATED-COMPOUNDS SO PHYSICAL REVIEW B LA English DT Note ID SUBSTITUTED YBA2CU3O7-DELTA; STRUCTURAL ANOMALIES; SUPERCONDUCTIVITY; BA2YCU3O7-DELTA; SPECTRA AB Cu-O radial distribution functions in YBa2Cu3O7, YBa2Cu3O6.5, and YBa2Cu2.8Co0.2O7+delta at 10 K have been determined from Cu K-edge polarized extended x-ray-absorption fine structure of these materials, using model potentials to describe the effect of the Cu-O relative motion. The analysis shows that the axial oxygen atom moves in a double-well potential. A correlation between interwell tunneling and T(c) is observed, and interpreted as a correlation between anharmonicity and T(c). RP DELEON, JM (reprint author), UNIV CALIF LOS ALAMOS SCI LAB,LOS ALAMOS,NM 87545, USA. NR 25 TC 40 Z9 40 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 AUG 1 PY 1991 VL 44 IS 5 BP 2422 EP 2425 PG 4 WC Physics, Condensed Matter SC Physics GA GA076 UT WOS:A1991GA07600063 ER PT J AU GIBAUD, A SHAPIRO, SM NOUET, J YOU, H AF GIBAUD, A SHAPIRO, SM NOUET, J YOU, H TI PHASE-DIAGRAM OF KMN1-XCAXF3(X LESS-THAN 0.05) DETERMINED BY HIGH-RESOLUTION X-RAY-SCATTERING SO PHYSICAL REVIEW B LA English DT Article ID R-POINT INSTABILITY; CRITICAL FLUCTUATIONS; KMNF3; TRANSITION; RBCAF3; IMPURITIES; SRTIO3 AB Precise high-resolution x-ray-diffraction measurements of the lattice parameters as a function of temperature are reported for the mixed system KMn(1-x)Ca(x)F3 in the concentration range x < 0.05. From the splitting of the cubic (0,0,4) Bragg reflection it is possible to determine the transition temperatures of the structural phase transitions which occur in this system and to establish the phase diagram in the concentration range x < 0.05. Three structural phase transitions are observed in this system and the transition temperatures at which they occur are enhanced when Mn2+ ions are substituted by Ca2+ ions. The enhancement rates are, respectively, 5.8, 18, and 14 K/at. % Ca2+ ions. This shows that a crossover between the T(c1) and the T(c2) transitions should occur at the extrapolated critical concentration x = 0.075. C1 UNIV MAINE,FAC SCI,F-72017 LE MANS,FRANCE. ARGONNE NATL LAB,DIV MAT SCI,ARGONNE,IL 60439. RP GIBAUD, A (reprint author), BROOKHAVEN NATL LAB,DEPT PHYS,UPTON,NY 11973, USA. RI You, Hoydoo/A-6201-2011 OI You, Hoydoo/0000-0003-2996-9483 NR 27 TC 55 Z9 55 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 AUG 1 PY 1991 VL 44 IS 6 BP 2437 EP 2443 DI 10.1103/PhysRevB.44.2437 PG 7 WC Physics, Condensed Matter SC Physics GA GA077 UT WOS:A1991GA07700001 ER PT J AU FITZSIMMONS, MR EASTMAN, JA MULLERSTACH, M WALLNER, G AF FITZSIMMONS, MR EASTMAN, JA MULLERSTACH, M WALLNER, G TI STRUCTURAL CHARACTERIZATION OF NANOMETER-SIZED CRYSTALLINE PD BY X-RAY-DIFFRACTION TECHNIQUES SO PHYSICAL REVIEW B LA English DT Article ID PALLADIUM; PARTICLES; GOLD AB Quantitative x-ray-diffraction measurements of ultrafine-grained (nanocrystalline) Pd samples and a coarse-grained polycrystalline reference foil were obtained using synchrotron radiation. The intensity profiles of the Bragg reflections from the nanocrystalline samples were considerably better represented by Lorentzian functions than by Gaussian functions, indicating that a large fraction of intensity from the Bragg peaks was found in the tails of the reflections. The remaining intensity differed only slightly for different grain-sized materials, therefore, atomic relaxations in the vicinity of grain boundaries in nanocrystalline Pd must be small in magnitude and/or extremely localized. The results of the present work do not support the previously proposed existence of either a "gaslike" grain boundary phase, or large quantities of vacancies or voids within the grains of nanocrystalline Pd, which produce broadly distributed diffuse scattering. The broadening of the Bragg reflections was related to the small particle size of nanocrystalline Pd, and strain located in the grains and/or interfacial regions. Evidence was seen for anisotropic grain shapes preferentially elongated along the [111] direction. The Debye-Waller parameter of nanocrystalline Pd was observed to be larger than the literature value for coarse-grained Pd, which suggests larger displacements of the atoms from their ideal lattice locations in the nanocrystalline material than in the coarse-grained material. C1 ARGONNE NATL LAB,DIV MAT SCI,ARGONNE,IL 60439. RP FITZSIMMONS, MR (reprint author), UNIV MUNICH,SEKT PHYS,W-8000 MUNICH 2,GERMANY. RI Eastman, Jeffrey/E-4380-2011; OI Eastman, Jeff/0000-0002-0847-4265 NR 23 TC 103 Z9 103 U1 0 U2 8 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 AUG 1 PY 1991 VL 44 IS 6 BP 2452 EP 2460 DI 10.1103/PhysRevB.44.2452 PG 9 WC Physics, Condensed Matter SC Physics GA GA077 UT WOS:A1991GA07700003 ER PT J AU LIU, HM POWELL, RC BOATNER, LA AF LIU, HM POWELL, RC BOATNER, LA TI EFFECT OF NIOBIUM DOPING ON THE PROPERTIES OF PICOSECOND LASER-INDUCED TRANSIENT GRATINGS IN KTA1-XNBXO3 SO PHYSICAL REVIEW B LA English DT Article ID SCATTERING; CRYSTALS; BATIO3; PHASE; KTN AB A study of the properties of laser-induced transient gratings produced in KTa(1-x)Nb(x)O3 Crystals by picosecond-pulse, two-photon excitation was carried out with use of degenerate-four-wave-mixing techniques. The grating properties were found to depend on the Nb concentration. The diffraction efficiency of the gratings exhibited a maximum at an intermediate Nb concentration while the signal decay rate increased uniformly with x. A lattice-relaxation model was developed to explain the experimental results that includes the intrinsic lattice distortion due to the niobium ions in the normally cubic perovskite crystal and the strong electron-phonon interaction causing a lattice distortion around photoionized ions. The predictions of the theoretical model agree with the experimental data. The results of grating decay rate measurements show that the excited states produced by two-photon laser excitation act as localized quasiparticles (excitons or polarons) having a hopping rate that increases with Nb concentration x. Strong electron-phonon coupling produces phonon-assisted, incoherent hopping migration. C1 OAK RIDGE NATL LAB,DIV SOLID STATE,OAK RIDGE,TN 37830. RP LIU, HM (reprint author), OKLAHOMA STATE UNIV,CTR LASER RES,STILLWATER,OK 74078, USA. RI Boatner, Lynn/I-6428-2013 OI Boatner, Lynn/0000-0002-0235-7594 NR 30 TC 28 Z9 28 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 AUG 1 PY 1991 VL 44 IS 6 BP 2461 EP 2469 DI 10.1103/PhysRevB.44.2461 PG 9 WC Physics, Condensed Matter SC Physics GA GA077 UT WOS:A1991GA07700004 ER PT J AU YONEMITSU, K BATISTIC, I BISHOP, AR AF YONEMITSU, K BATISTIC, I BISHOP, AR TI RANDOM-PHASE-APPROXIMATION APPROACH TO COLLECTIVE MODES AROUND INHOMOGENEOUS HARTREE-FOCK STATES - ONE-DIMENSIONAL DOPED HUBBARD-MODEL SO PHYSICAL REVIEW B LA English DT Article ID SPIN-WAVE THEORY; HIGH-TEMPERATURE SUPERCONDUCTIVITY; N-ELECTRONS SYSTEM; QUANTUM ANTIFERROMAGNET; BAG MECHANISM; FLUCTUATIONS; EXCITATIONS; MOTION; HOLE AB All the linear excitations are calculated in the random-phase approximation around a doped inhomogeneous Hartree-Fock state as well as the undoped uniform antiferromagnetic state in the one-dimensional Hubbard model. Upon doping, shape modes appear, localized around an introduced hole, as well as some "shake-off" branches related to combinations of local and extended Hartree-Fock orbitals. These modes are in addition to spin wave and ultragap branches in the pure antiferromagnetic state. Some characteristics of the shape modes are similar to bare processes in the t-t'-J model derived from the Hubbard model at strong coupling. Spectral weights in different susceptibility channels are calculated and shown to have peaks in low-energy regions, arising from specific shape modes. RP YONEMITSU, K (reprint author), UNIV CALIF LOS ALAMOS SCI LAB,DIV THEORET,LOS ALAMOS,NM 87545, USA. NR 38 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 0163-1829 J9 PHYS REV B JI Phys. Rev. B PD AUG 1 PY 1991 VL 44 IS 6 BP 2652 EP 2663 DI 10.1103/PhysRevB.44.2652 PG 12 WC Physics, Condensed Matter SC Physics GA GA077 UT WOS:A1991GA07700024 ER PT J AU XU, M AF XU, M TI CALCULATIONS OF REMANENT MAGNETIZATION FOR HARD SUPERCONDUCTORS IN VARIOUS CRITICAL-STATE MODELS SO PHYSICAL REVIEW B LA English DT Article ID HIGH-TC SUPERCONDUCTORS; RELAXATION; CRYSTAL AB Detailed calculations of remanent magnetization for hard superconductors are carried out, based on various critical-state relations. There are three different field stages distinguished by two characteristic penetration fields, H-1* and H-2*. Remanent magnetization in each stage has a different field dependence which initially increases smoothly with increasing field, then is sharply enhanced with the field, and finally crosses over to a saturation value. The calculated remanent magnetizations are in good agreement with experimental data for both conventional and high-T(c) superconductors. Also discussed are the flux-pinning picture, the scaling behavior of the remanent magnetization, and the physical meaning of the penetration fields. C1 IOWA STATE UNIV SCI & TECHNOL,DEPT PHYS,AMES,IA 50011. RP XU, M (reprint author), IOWA STATE UNIV SCI & TECHNOL,AMES LAB,AMES,IA 50011, USA. NR 22 TC 20 Z9 21 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 AUG 1 PY 1991 VL 44 IS 6 BP 2713 EP 2719 DI 10.1103/PhysRevB.44.2713 PG 7 WC Physics, Condensed Matter SC Physics GA GA077 UT WOS:A1991GA07700029 ER PT J AU CLEM, JR COFFEY, MW HAO, ZD AF CLEM, JR COFFEY, MW HAO, ZD TI LOWER CRITICAL-FIELD OF A JOSEPHSON-COUPLED LAYER MODEL OF HIGH-TC SUPERCONDUCTORS SO PHYSICAL REVIEW B LA English DT Article ID YBA2CU3O7-DELTA SINGLE-CRYSTALS; TEMPERATURE-DEPENDENCE; ORGANIC SUPERCONDUCTOR; PENETRATION DEPTH; II SUPERCONDUCTORS; ANGULAR-DEPENDENCE; ANISOTROPY; BI2.2SR2CA0.8CU2O8+DELTA; VORTICES AB We calculate the lower critical field H(c1) for a magnetic field applied parallel to the layers of a Josephson-coupled layer model of high-T(c) superconductors. This result is obtained by using an expression for the vortex line energy that explicitly involves the gauge-invariant phase difference between superconducting layers. We examine the behavior of H(c1) as a function of temperature and discuss the manifestation of the superconductor discreteness below a crossover temperature where the coherence length zeta-c(T) becomes comparable to the lattice constant c. This temperature dependence is contrasted with the standard result for H(c1) for a continuous anisotropic type-II superconductor. C1 IOWA STATE UNIV SCI & TECHNOL, DEPT PHYS & ASTRON, AMES, IA 50011 USA. RP CLEM, JR (reprint author), IOWA STATE UNIV SCI & TECHNOL, AMES LAB, AMES, IA 50011 USA. NR 47 TC 92 Z9 93 U1 0 U2 3 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 AUG 1 PY 1991 VL 44 IS 6 BP 2732 EP 2738 DI 10.1103/PhysRevB.44.2732 PG 7 WC Physics, Condensed Matter SC Physics GA GA077 UT WOS:A1991GA07700032 ER PT J AU GEHRING, PM TRANQUADA, JM SHIRANE, G COPLEY, JRD ERWIN, RW SATO, M SHAMOTO, S AF GEHRING, PM TRANQUADA, JM SHIRANE, G COPLEY, JRD ERWIN, RW SATO, M SHAMOTO, S TI MAGNETIC CORRELATIONS AND ENERGY-GAP IN SUPERCONDUCTING YBA2CU3O6.6 WITH TC=53K SO PHYSICAL REVIEW B LA English DT Note ID NEUTRON-SCATTERING; EXCITATIONS; TC AB The dynamic magnetic correlations have been characterized in a large, orthorhombic single crystal of YBa2Cu3O6+x with x = 0.6, having a T(c) of 53 K. Inelastic-neutron-scattering measurements reveal a gap (zero magnetic cross section) of 5 meV in the spin-excitation spectrum at 10 K. The size of the gap fits well between those reported by Rossat-Mignod et al. for x = 0.51 and 0.69. However, the rapid change in the gap size with a relatively small change in T(c) is not understood. C1 NATL INST STAND & TECHNOL,GAITHERSBURG,MD 20899. NAGOYA UNIV,NAGOYA 46401,JAPAN. RP GEHRING, PM (reprint author), BROOKHAVEN NATL LAB,UPTON,NY 11973, USA. RI Tranquada, John/A-9832-2009; OI Tranquada, John/0000-0003-4984-8857; Gehring, Peter/0000-0002-9236-2046 NR 12 TC 32 Z9 32 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 AUG 1 PY 1991 VL 44 IS 6 BP 2811 EP 2814 DI 10.1103/PhysRevB.44.2811 PG 4 WC Physics, Condensed Matter SC Physics GA GA077 UT WOS:A1991GA07700047 ER PT J AU ROMERO, DB CARR, GL TANNER, DB FORRO, L MANDRUS, D MIHALY, L WILLIAMS, GP AF ROMERO, DB CARR, GL TANNER, DB FORRO, L MANDRUS, D MIHALY, L WILLIAMS, GP TI 12KBTC OPTICAL SIGNATURE OF SUPERCONDUCTIVITY IN SINGLE-DOMAIN BI2SR2CACU2O8 SO PHYSICAL REVIEW B LA English DT Note ID NORMAL-STATE; CRYSTALS; YBA2CU3O7-DELTA; CONDUCTIVITY; REFLECTIVITY; GAP AB Infrared and far-infrared transmittance measurements were performed on Bi2Sr2CaCU2O8 (2:2:1:2) and Bi2Sr2CuO6 (2:2:0:1). Below T(c), a characteristic feature occurs at omega = 700 cm-1 (12k(B)T(c)) in the 2:2:1:2 material. No similar feature is found in the 2:2:0:1 compound. The 2:2:1:2 material also showed substantial ab-plane anisotropy. C1 SUNY STONY BROOK,DEPT PHYS,STONY BROOK,NY 11794. BROOKHAVEN NATL LAB,NATL SYNCHROTRON LIGHT SOURCE,UPTON,NY 11973. UNIV ZAGREB,INST PHYS,YU-41001 ZAGREB,YUGOSLAVIA. RP ROMERO, DB (reprint author), UNIV FLORIDA,DEPT PHYS,GAINESVILLE,FL 32611, USA. RI Mandrus, David/H-3090-2014 NR 26 TC 22 Z9 22 U1 0 U2 0 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 0163-1829 J9 PHYS REV B JI Phys. Rev. B PD AUG 1 PY 1991 VL 44 IS 6 BP 2818 EP 2821 DI 10.1103/PhysRevB.44.2818 PG 4 WC Physics, Condensed Matter SC Physics GA GA077 UT WOS:A1991GA07700049 ER PT J AU FRAHM, R BARBEE, TW WARBURTON, W AF FRAHM, R BARBEE, TW WARBURTON, W TI INSITU STRUCTURAL STUDY OF THIN-FILM GROWTH BY QUICK-SCANNING X-RAY-ABSORPTION SPECTROSCOPY SO PHYSICAL REVIEW B LA English DT Note ID EXAFS; ALLOYS; ORDER; CU AB Results of in situ quick-scanning extended x-ray-absorption fine-structure measurements during vacuum sputter deposition of thin films are reported. Cu overlayers equivalent to 1-72 monolayers thickness were sputtered onto a substrate. Up to a few monolayers thickness, the Cu seems to form small clusters. At coverages above 38 monolayers, the nearest-neighbor environment remains unchanged, whereas the third- and fourth-nearest-neighbor peaks are still growing: significant structural disorder exists even in the 72-monolayer sample. The changes of the local environment with Cu thickness are also directly visible in the near-edge spectra. C1 UNIV CALIF LAWRENCE LIVERMORE NATL LAB,LIVERMORE,CA 94551. X-RAY INSTRUMENTAT ASSOCIATES,MENLO PK,CA 94025. RP FRAHM, R (reprint author), DESY,HAMBURGER SYNCHROTRONSTRAHLUNGSLABOR HASYLAB,NOTKESTR 85,W-2000 HAMBURG 52,GERMANY. NR 15 TC 22 Z9 22 U1 0 U2 1 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 0163-1829 J9 PHYS REV B JI Phys. Rev. B PD AUG 1 PY 1991 VL 44 IS 6 BP 2822 EP 2825 DI 10.1103/PhysRevB.44.2822 PG 4 WC Physics, Condensed Matter SC Physics GA GA077 UT WOS:A1991GA07700050 ER PT J AU BUSSMANNHOLDER, A BISHOP, AR AF BUSSMANNHOLDER, A BISHOP, AR TI ANHARMONICITY-INDUCED MULTIPHONON PROCESSES IN HIGH-TEMPERATURE SUPERCONDUCTORS SO PHYSICAL REVIEW B LA English DT Note ID TRANSITION-TEMPERATURE; MODEL; YBA2CU3O7-DELTA; MECHANISM; TRANSPORT; PHONONS AB Electron-two-phonon interactions are considered on the basis of an extended BCS-type Hamiltonian. An equation for the superconducting transition temperature T(c) and the energy gap 2-DELTA-0 is derived in the weak-coupling limit. Instead of a Debye frequency a reduced optic-acoustic mode frequency, together with a coupled effective electron-phonon interaction, determines the magnitude of T(c). This leads to a distinctly different isotope effect from BCS, which is compared with data on La(2-x)Sr(x)CuO4. The energy gap is predicted to be anisotropic and 2-DELTA-0/kT(c) to be compound dependent. C1 UNIV BAYREUTH, W-8580 BAYREUTH, GERMANY. UNIV CALIF LOS ALAMOS SCI LAB, DIV THEORET, LOS ALAMOS, NM 87545 USA. RP BUSSMANNHOLDER, A (reprint author), MAX PLANCK INST FESTKORPERFORSCH, HEISENBERGSTR 1, W-7000 STUTTGART 80, GERMANY. NR 46 TC 49 Z9 49 U1 0 U2 0 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 AUG 1 PY 1991 VL 44 IS 6 BP 2853 EP 2856 DI 10.1103/PhysRevB.44.2853 PG 4 WC Physics, Condensed Matter SC Physics GA GA077 UT WOS:A1991GA07700058 ER PT J AU ZHU, YM SUENAGA, M TAFTO, J WELCH, DO AF ZHU, YM SUENAGA, M TAFTO, J WELCH, DO TI VARIABLE NATURE OF TWIN BOUNDARIES IN YBA2CU3O7-DELTA AND ITS ALLOYS SO PHYSICAL REVIEW B LA English DT Note ID BA-CU-O; YBA2(CU1-XFEX)3O7-DELTA; SUPERCONDUCTORS; MICROSTRUCTURE; DIFFRACTION AB High-resolution electron microscopy and electron diffraction of YBa2(Cu0.98M0.02)3O7-delta with M = Zn, Ni, Al, Fe, Cu indicate that twin boundaries are centered on (110) planes through the O atoms in the CuO layer for delta almost-equal-to 0 and M-Ni, Zn, or Cu, accompanied by a displacement of the cation sublattices across the boundary. Oxygen deficiency causes a shift of the center of twin boundaries to (110) planes through the cations and eliminates the cation-sublattice displacement, while solutes M = Al or Fc (even for oxygen content in excess of 7.00) substantially reduce the magnitude of the cation-sublattice displacement. C1 UNIV OSLO,DEPT PHYS,OSLO 3,NORWAY. RP ZHU, YM (reprint author), BROOKHAVEN NATL LAB,DEPT APPL SCI,DIV MAT SCI,UPTON,NY 11973, USA. NR 22 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 AUG 1 PY 1991 VL 44 IS 6 BP 2871 EP 2874 DI 10.1103/PhysRevB.44.2871 PG 4 WC Physics, Condensed Matter SC Physics GA GA077 UT WOS:A1991GA07700063 ER PT J AU MA, WH STROTTMAN, D AF MA, WH STROTTMAN, D TI ANTIPROTON-INDUCED ELASTIC AND INELASTIC-SCATTERING AT INTERMEDIATE ENERGIES SO PHYSICAL REVIEW C LA English DT Article ID SINGLE-CHARGE-EXCHANGE; NUCLEUS SCATTERING; REAL PART; AMPLITUDE; CARBON; PBARP; C-12; GEV/C AB Results are presented of zero-parameter calculations of antiproton-induced elastic and inelastic scattering from C-12, O-16, Ca-40 for five kinetic energies from 0.23 to 1.83 GeV. The Glauber model is employed with microscopic shell-model wave functions, Woods-Saxon single-particle wave functions, and experimental pNBAR amplitudes. C1 CHINESE ACAD SCI,INST HIGH ENERGY PHYS,BEIJING,PEOPLES R CHINA. RP MA, WH (reprint author), UNIV CALIF LOS ALAMOS SCI LAB,DIV THEORET,LOS ALAMOS,NM 87545, USA. NR 29 TC 5 Z9 9 U1 0 U2 0 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 0556-2813 J9 PHYS REV C JI Phys. Rev. C PD AUG PY 1991 VL 44 IS 2 BP 615 EP 618 DI 10.1103/PhysRevC.44.615 PG 4 WC Physics, Nuclear SC Physics GA GB126 UT WOS:A1991GB12600011 ER PT J AU CARLSON, J RISKA, DO SCHIAVILLA, R WIRINGA, RB AF CARLSON, J RISKA, DO SCHIAVILLA, R WIRINGA, RB TI WEAK PROTON CAPTURE REACTIONS ON H-1 AND HE-3 AND TRITIUM BETA-DECAY SO PHYSICAL REVIEW C LA English DT Article ID MESON EXCHANGE CURRENTS; CROSS-SECTION; FORM-FACTORS; NUCLEI AB The cross sections for the weak proton capture reactions p + p --> d + e+ + nu-e and p + He-3 --> He-4 + e+ + nu-e have been calculated with realistic wave functions determined by using the Argonne upsilon-14 nucleon-nucleon interaction. To minimize the uncertainty in the axial exchange current operator, its matrix element has been adjusted so as to reproduce the measured Gamow-Teller matrix element for beta-decay of tritium. The exchange current contribution enhances the calculated rate of the pp capture reaction by 1.5% and decreases that of the p He-3 reaction by almost a factor of 5. C1 UNIV HELSINKI,DEPT PHYS,SF-00170 HELSINKI 17,FINLAND. ARGONNE NATL LAB,DIV PHYS,ARGONNE,IL 60439. RP CARLSON, J (reprint author), UNIV CALIF LOS ALAMOS SCI LAB,DIV THEORY,LOS ALAMOS,NM 87545, USA. RI Wiringa, Robert/M-4970-2015 NR 38 TC 63 Z9 63 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 AUG PY 1991 VL 44 IS 2 BP 619 EP 625 DI 10.1103/PhysRevC.44.619 PG 7 WC Physics, Nuclear SC Physics GA GB126 UT WOS:A1991GB12600012 ER PT J AU JOHNSON, CH CARLTON, RF WINTERS, RR AF JOHNSON, CH CARLTON, RF WINTERS, RR TI EVIDENCE FOR PARITY DEPENDENCE IN THE NEUTRON-AR-40 OPTICAL-MODEL POTENTIAL SO PHYSICAL REVIEW C LA English DT Article ID NEUTRON-PB-208 MEAN FIELD; ENERGY-DEPENDENCE; SCATTERING; PB-208; RESONANCE; YTTRIUM; SHELL; CA-40 AB The neutron dispersive optical model potential that was developed previously from an analysis of extensive data on the neutron-Ca-40 system is adapted to the neutron-Ar-40 system by adjusting the central depth of the local equivalent of the Hartree-Fock-type potential. The n-Ar-40 data for this adjustment are the total cross section for 11 < E < 40 MeV and the centroid energy for the observed single-particle and single-hole states of the valence shells. The resulting potential for n-Ar-40 yields good predictions for the particle-hole gap for the valence shells and for the energy-averaged s-wave and p-wave scattering functions in the resonance region. However, it gives a poor prediction for the total cross section from 2 to 11 MeV. A similar discrepancy was observed earlier for Ca-40. A parity dependence in the surface imaginary potential is suggested from a more careful examination of the s-wave and p-wave scattering functions for Ar-40; that parity dependence gives a good prediction of the total cross section for 2 to 11 MeV. C1 OAK RIDGE NATL LAB,OAK RIDGE,TN 37831. MIDDLE TENNESSEE STATE UNIV,MURFREESBORO,TN 37132. DENISON UNIV,GRANVILLE,OH 43023. NR 41 TC 3 Z9 3 U1 0 U2 0 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 0556-2813 J9 PHYS REV C JI Phys. Rev. C PD AUG PY 1991 VL 44 IS 2 BP 657 EP 667 DI 10.1103/PhysRevC.44.657 PG 11 WC Physics, Nuclear SC Physics GA GB126 UT WOS:A1991GB12600015 ER PT J AU SETHI, A HINTZ, NM MIHAILIDIS, DN MACK, AM GAZZALY, M JONES, KW PAULETTA, G SANTI, L GOUTTE, D AF SETHI, A HINTZ, NM MIHAILIDIS, DN MACK, AM GAZZALY, M JONES, KW PAULETTA, G SANTI, L GOUTTE, D TI INELASTIC PROTON-SCATTERING FROM PT ISOTOPES AND THE INTERACTING BOSON MODEL SO PHYSICAL REVIEW C LA English DT Article ID COLLECTIVE NUCLEAR-STATES; HEAVY TRANSITIONAL NUCLEI; PARTIAL-WAVE ANALYSIS; ELECTROMAGNETIC PROPERTIES; QUADRUPOLE-MOMENTS; ELASTIC-SCATTERING; EVEN-EVEN; ELECTRON-SCATTERING; DEFORMED-NUCLEI; EXCITED-STATES AB Inelastic proton scattering has been used to measure the d-sigma/d-OMEGA and A(y) angular distributions for several low-lying collective states in Pt-194, Pt-196 using 647 MeV polarized protons with special emphasis on the excitation of the 4+ states below 2 MeV. The data have been analyzed in the framework of the coupled-channels scheme using the program ECIS. Large E4 transition strengths to the 4+ states in both nuclei are found in sharp contrast with the predictions of the interacting boson model with only s (L = 0) and d (L = 2) bosons. It is found that although the E2 properties of these nuclei are consistent with the interacting boson model (sd) predictions, higher degrees of freedom, e.g., g (L = 4) bosons, need to be invoked in order to get a reasonable agreement with the measured E4 properties. C1 UNIV CALIF LOS ALAMOS SCI LAB,LOS ALAMOS,NM 87545. UNIV UDINE,I-33100 UDINE,ITALY. CENS,F-91191 GIF SUR YVETTE,FRANCE. RP SETHI, A (reprint author), UNIV MINNESOTA,SCH PHYS,MINNEAPOLIS,MN 55455, USA. NR 96 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 0556-2813 J9 PHYS REV C JI Phys. Rev. C PD AUG PY 1991 VL 44 IS 2 BP 700 EP 712 DI 10.1103/PhysRevC.44.700 PG 13 WC Physics, Nuclear SC Physics GA GB126 UT WOS:A1991GB12600019 ER PT J AU CHIANG, HC OSET, E LIU, LC AF CHIANG, HC OSET, E LIU, LC TI WIDTH OF BOUND ETA IN NUCLEI SO PHYSICAL REVIEW C LA English DT Article ID DELTA-SELF-ENERGY; ANTIPROTON ANNIHILATION; MESIC NUCLEUS; PIONIC ATOMS; MATTER; MESON; MODEL; SCATTERING; STATES AB Assuming the eta-N interaction is dominated by the N*(1535) excitation we evaluate an eta-nucleus optical potential that takes into account the free decay modes of the N* plus its many-body decay modes up to one-particle-hole excitation. The potential is able to generate bound states in light and heavy nuclei but provides large widths for these states. The results are highly sensitive to the value of Re-SIGMA-N*. In general, the widths are larger than the separation between the levels, although for Re-SIGMA-N* sufficiently repulsive a few narrow states can be found. In connection with a recent experiment our results suggest a potential for the N* more attractive than for nucleons. C1 UNIV VALENCIA,CSIC,INST FIS,CTR MIXTO,DEPT FIS TEOR,VALENCIA,SPAIN. UNIV VALENCIA,CSIC,INST FIS,CTR MIXTO,INST FIS CORPUSCULAR,VALENCIA,SPAIN. UNIV CALIF LOS ALAMOS SCI LAB,LOS ALAMOS,NM 87545. NR 32 TC 87 Z9 91 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 AUG PY 1991 VL 44 IS 2 BP 738 EP 746 DI 10.1103/PhysRevC.44.738 PG 9 WC Physics, Nuclear SC Physics GA GB126 UT WOS:A1991GB12600023 ER PT J AU LYNN, JE JURNEY, ET RAMAN, S AF LYNN, JE JURNEY, ET RAMAN, S TI DIRECT AND VALENCE NEUTRON-CAPTURE BY LI-7 SO PHYSICAL REVIEW C LA English DT Article ID GAMMA-RAYS; ISOTOPES; C-13 AB We have measured the cross section for neutron radiative capture by Li-7 at thermal neutron energy as 45.4 +/- 3.0 mb. We have compared this value, and the available fast-neutron-capture cross-section data on Li-7, with direct- and valence-capture theory. The mechanism of direct capture involving simple neutron-orbital transitions within a potential well can adequately account for the magnitude of the thermal-neutron-capture cross sections and the shape of the fast-neutron-capture cross sections. We recommend that the capture cross sections from the theoretical calculation, instead of those from a recent measurement, be used for nuclear astrophysics calculations. If the fast-neutron-capture data are normalized at 25 keV to the theoretical value, the magnetic-dipole (M 1) radiation width of the 255-keV p-wave resonance can be deduced. It is in agreement with the value calculated from a valence theory for M 1 capture, thus lending support for this neutron-capture mechanis as an important one, at least for light nuclei. We also find some evidence from our analysis of the total cross-section data for a possible energy dependence of the potential required to describe the almost pure single-particle s-wave resonances underlying the Li-7 cross section. C1 OAK RIDGE NATL LAB,OAK RIDGE,TN 37831. RP LYNN, JE (reprint author), UNIV CALIF LOS ALAMOS SCI LAB,LOS ALAMOS,NM 87545, USA. NR 26 TC 41 Z9 41 U1 0 U2 0 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 0556-2813 J9 PHYS REV C JI Phys. Rev. C PD AUG PY 1991 VL 44 IS 2 BP 764 EP 773 DI 10.1103/PhysRevC.44.764 PG 10 WC Physics, Nuclear SC Physics GA GB126 UT WOS:A1991GB12600026 ER PT J AU PARKER, WE KAPLAN, M MOSES, DJ LARANA, G LOGAN, D LACEY, R ALEXANDER, JM RIZZO, DMD DEYOUNG, P WELBERRY, RJ BOGER, JT AF PARKER, WE KAPLAN, M MOSES, DJ LARANA, G LOGAN, D LACEY, R ALEXANDER, JM RIZZO, DMD DEYOUNG, P WELBERRY, RJ BOGER, JT TI CHARGED-PARTICLE EVAPORATION FROM HOT COMPOSITE NUCLEI - EVIDENCE OVER A BROAD Z-RANGE FOR DISTORTIONS FROM COLD NUCLEAR PROFILES SO PHYSICAL REVIEW C LA English DT Article ID LARGE-ANGLE CORRELATIONS; 337 MEV AR-40+(NAT)AG; DEFORMED CU-59 NUCLEI; HEAVY-ION REACTIONS; COMPOUND NUCLEI; ANGULAR-MOMENTUM; NEUTRON-EMISSION; LIGHT PARTICLES; COINCIDENCE MEASUREMENTS; FE-56+AU-197 REACTIONS AB Charged-particle emission has been studied in ten heavy-ion reactions spanning composite systems of 16 less-than-or-equal-to Z less-than-or-equal-to 64. By means of reversed kinematics, high-quality energy spectra were obtained for proton and alpha evaporation from compound nuclei with temperatures approximately 1.5-3.5 MeV and spins up to approximately 70h. In some cases, deuteron and triton spectra were recorded as well. Statistical model calculations for spherical nuclei require systematically low emission barriers to reproduce the data. For the lighter systems, the effective spins (or moments of inertia) must be modified as well, whereas for the heavier systems this effect is of less importance. The roles of multistep particle emission and competition in the model calculations are assessed and found to be inadequate to explain the observed discrepancies. Calculations that model statically deformed nuclear emitters suggest that large deformations may be present, but they do not give a satisfactory overall picture. The very low proton energies in particular seem to indicate an extended density profile. Such an effect, together with the requirements for cluster preformation, may explain the observed low barriers for H-1/He-4 and the increasing mean energies found for the series H-1, H-2, H-3, respectively. C1 CARNEGIE MELLON UNIV,DEPT CHEM,PITTSBURGH,PA 15213. UNIV CALIF BERKELEY LAWRENCE BERKELEY LAB,BERKELEY,CA 94720. SUNY STONY BROOK,DEPT CHEM,STONY BROOK,NY 11794. SUNY STONY BROOK,DEPT PHYS,STONY BROOK,NY 11794. INST NAZL FIS NUCL,MOSTRA OLTREMARE,I-80125 NAPLES,ITALY. IBM CORP,KINGSTON,NY 12401. HOPE COLL,DEPT PHYS,HOLLAND,MI 49432. NR 95 TC 57 Z9 57 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 AUG PY 1991 VL 44 IS 2 BP 774 EP 795 DI 10.1103/PhysRevC.44.774 PG 22 WC Physics, Nuclear SC Physics GA GB126 UT WOS:A1991GB12600027 ER PT J AU CHADWICK, MB OBLOZINSKY, P HODGSON, PE REFFO, G AF CHADWICK, MB OBLOZINSKY, P HODGSON, PE REFFO, G TI PAULI-BLOCKING IN THE QUASIDEUTERON MODEL OF PHOTOABSORPTION SO PHYSICAL REVIEW C LA English DT Article ID NUCLEAR CROSS-SECTIONS; QUASI-DEUTERON MODEL; HEAVY-ION COLLISIONS; HARD PHOTONS AB We calculate the effects of Pauli-blocking in the quasideuteron model of hard photon-absorption. Our approach is based upon phase space considerations and uses Fermi-gas state densities that conserve linear momentum. The Pauli-blocking function that we obtain differs from Levinger's phenomenological exponential factor and yields nuclear photoabsorption cross sections that are in good agreement with experimental data for photon energies up to the pion threshold. The temperature dependence of the nuclear photoabsorption cross section in the quasideuteron regime is also investigated. The model that we use to describe nuclear photoabsorption is particularly suited for application to preequilibrium models of hard photon emission. C1 UNIV OXFORD,NUCL PHYS LAB,OXFORD OX1 3RH,ENGLAND. ENTE NAZL ENERGIE ALTERNAT,I-40138 BOLOGNA,ITALY. SLOVAK ACAD SCI,INST PHYS,CS-84228 BRATISLAVA,CZECHOSLOVAKIA. RP CHADWICK, MB (reprint author), UNIV CALIF LOS ALAMOS SCI LAB,DIV THEORET,LOS ALAMOS,NM 87545, USA. NR 24 TC 67 Z9 70 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 AUG PY 1991 VL 44 IS 2 BP 814 EP 823 DI 10.1103/PhysRevC.44.814 PG 10 WC Physics, Nuclear SC Physics GA GB126 UT WOS:A1991GB12600030 ER PT J AU BONETTI, R CHIESA, C GUGLIELMETTI, A MIGLIORINO, C CESANA, A TERRANI, M PRICE, PB AF BONETTI, R CHIESA, C GUGLIELMETTI, A MIGLIORINO, C CESANA, A TERRANI, M PRICE, PB TI NEON RADIOACTIVITY OF URANIUM ISOTOPES SO PHYSICAL REVIEW C LA English DT Note ID DECAY; U-234; EMISSION AB We report a new measurement of the rate of spontaneous emission of monoenergetic Ne nuclear clusters from U-232, which results in a revision of rates previously reported for Ne radioactivity of U-232, U-234, and U-235. The Ne emission rate goes up a factor of 4.6 for U-232, goes down a factor of 4.8 for U-234, and may have been marginally detected (1.9-sigma) for U-235. C1 POLITECN MILAN,CTR STUDI NUCL ENRICO FERMI,I-20133 MILAN,ITALY. UNIV CALIF BERKELEY,DEPT PHYS,BERKELEY,CA 94720. UNIV CALIF BERKELEY LAWRENCE BERKELEY LAB,DIV NUCL SCI,BERKELEY,CA 94720. RP BONETTI, R (reprint author), UNIV MILAN,IST NAZL FIS NUCL,IST FIS GEN APPLICATA,SEZIONE MILANO,I-20122 MILAN,ITALY. NR 11 TC 20 Z9 20 U1 0 U2 0 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 0556-2813 J9 PHYS REV C JI Phys. Rev. C PD AUG PY 1991 VL 44 IS 2 BP 888 EP 890 DI 10.1103/PhysRevC.44.888 PG 3 WC Physics, Nuclear SC Physics GA GB126 UT WOS:A1991GB12600039 ER PT J AU CHADWICK, MB REFFO, G AF CHADWICK, MB REFFO, G TI PREEQUILIBRIUM EMISSION OF HARD PHOTONS IN PROTON-NUCLEUS REACTIONS - COMMENT SO PHYSICAL REVIEW C LA English DT Note ID COLLISIONS; MODEL; DECAY AB We show that the level-density prescription adopted by Oblozinsky in his preequilibrium hardphoton emission model leads to an incorrect division of the photoabsorption cross section among the accessible 2p-2h states, resulting in theoretical emission spectra that are underestimated by a factor 2.86. By using Fermi-gas rather than equidistant single-particle levels, a more accurate treatment of preequilibrium photon emission is obtained. We also note a close similarity between the photon emission rates predicted by the preequilibrium model and those that are obtained using bremsstrahlung theory. C1 ENTE NAZL ENERGIE ALTERNAT,I-40138 BOLOGNA,ITALY. RP CHADWICK, MB (reprint author), UNIV CALIF LOS ALAMOS SCI LAB,DIV THEORET,LOS ALAMOS,NM 87545, USA. NR 10 TC 3 Z9 3 U1 0 U2 0 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 0556-2813 J9 PHYS REV C JI Phys. Rev. C PD AUG PY 1991 VL 44 IS 2 BP 919 EP 922 DI 10.1103/PhysRevC.44.919 PG 4 WC Physics, Nuclear SC Physics GA GB126 UT WOS:A1991GB12600048 ER PT J AU BLANN, M MUSTAFA, MG AF BLANN, M MUSTAFA, MG TI MULTIFRAGMENTATION FOR AR-36+U-238 TREATED AS STATISTICAL DYNAMIC INTERACTION PROCESSES SO PHYSICAL REVIEW C LA English DT Note ID HEAVY-ION COLLISIONS; ENERGY GAMMA-RAYS; P BREMSSTRAHLUNG INTERPRETATION; SUBTHRESHOLD PION-PRODUCTION; FUSION-FISSION AB The exclusive multifragment multiplicities for the system Ar-36 + U-238 at 35 MeV/nucleon incident energy are calculated using the Boltzmann master equation for the fast cascade, and the Weisskopf-Ewing evaporation model for successive binary decay of the equilibrated residues. These calculated results are consistent with the experimental results of Kim et al. We show that the multiplicity distribution in such a model has a sensitivity to the equilibrated excitation, so that multiplicity could be an observable characteristic of excitation. This in turn may be used to infer time delay for fragment emission (in a model dependent way). RP BLANN, M (reprint author), UNIV CALIF LAWRENCE LIVERMORE NATL LAB,LIVERMORE,CA 94550, USA. NR 37 TC 7 Z9 7 U1 0 U2 0 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 0556-2813 J9 PHYS REV C JI Phys. Rev. C PD AUG PY 1991 VL 44 IS 2 BP R590 EP R593 DI 10.1103/PhysRevC.44.R590 PG 4 WC Physics, Nuclear SC Physics GA GB126 UT WOS:A1991GB12600006 ER PT J AU WONG, CY WANG, RC AF WONG, CY WANG, RC TI FRAGMENTATION OF A FINITE-MASS STRING SO PHYSICAL REVIEW D LA English DT Article ID LUND MONTE-CARLO; JET FRAGMENTATION; E+E-PHYSICS; MODEL; DYNAMICS AB We study a string fragmentation model in which the probability distribution for the locations of the vertices is parametrized explicitly in terms of their space-time coordinates measured from the point of the onset of separation of the quark and the antiquark. An iterative procedure is presented to fragment a finite-mass string into hadrons. We apply the model to calculate the rapidity distribution of the produced hadrons, which is found to give a good fit to the experimental data for e+-e-annihilation at 29 GeV. From the parameters characterizing the probability distribution of the vertices, we determine the average hadron formation time in the fragmentation of the string. C1 UNIV SCI & TECHNOL CHINA,CTR ASTROPHYS,HEFEI,PEOPLES R CHINA. RP WONG, CY (reprint author), OAK RIDGE NATL LAB,OAK RIDGE,TN 37831, USA. OI Wong, Cheuk-Yin/0000-0001-8223-0659 NR 23 TC 0 Z9 0 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 AUG 1 PY 1991 VL 44 IS 3 BP 679 EP 691 DI 10.1103/PhysRevD.44.679 PG 13 WC Astronomy & Astrophysics; Physics, Particles & Fields SC Astronomy & Astrophysics; Physics GA FY346 UT WOS:A1991FY34600013 ER PT J AU MALTMAN, K AF MALTMAN, K TI SIZE OF ELECTROMAGNETIC EFFECTS IN PSI'-]J/PSI+PI-0 SO PHYSICAL REVIEW D LA English DT Article ID LIGHT-QUARK MASSES; ETA-MESONS; DECAYS AB We reexamine the question of the relative size of electromagnetic and quark-mass-difference-induced contributions to the amplitude for psi' --> J/psi + pi-0 and find that the ratio of the former to the latter is significantly smaller than estimated by Donoghue and Tuan, further strengthening their case for GAMMA(psi' --> J/psi + pi-0)/GAMMA(psi' --> J/psi + eta) as a reliable source for the determination of the mass ratio m(u)/m(d). C1 UNIV CALIF LOS ALAMOS SCI LAB,DIV THEORET,LOS ALAMOS,NM 87545. RP MALTMAN, K (reprint author), UNIV TORONTO,DEPT PHYS,60 ST GEORGE ST,TORONTO M3J 1P3,ONTARIO,CANADA. NR 22 TC 12 Z9 12 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 AUG 1 PY 1991 VL 44 IS 3 BP 751 EP 755 DI 10.1103/PhysRevD.44.751 PG 5 WC Astronomy & Astrophysics; Physics, Particles & Fields SC Astronomy & Astrophysics; Physics GA FY346 UT WOS:A1991FY34600019 ER PT J AU LEBED, RF SUZUKI, M AF LEBED, RF SUZUKI, M TI CURRENT-ALGEBRA AND THE ADEMOLLO-GATTO THEOREM IN SPIN-FLAVOR SYMMETRY OF HEAVY QUARKS SO PHYSICAL REVIEW D LA English DT Article ID EFFECTIVE FIELD-THEORY; SEMILEPTONIC DECAYS; FORM-FACTORS; MESONS; LIGHT; MODEL; QCD AB The current algebra of effective weak currents is studied in detail for spin-flavor symmetry of heavy quarks. Technical issues involved in the derivation of Luke's renormalization-free theorem by Boyd and Brahm through the Ademollo-Gatto theorem are examined and elaborated upon. C1 UNIV CALIF BERKELEY LAWRENCE BERKELEY LAB, BERKELEY, CA 94720 USA. RP UNIV CALIF BERKELEY, DEPT PHYS, BERKELEY, CA 94720 USA. NR 27 TC 11 Z9 11 U1 0 U2 1 PU AMER PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 2470-0010 EI 2470-0029 J9 PHYS REV D JI Phys. Rev. D PD AUG 1 PY 1991 VL 44 IS 3 BP 829 EP 836 DI 10.1103/PhysRevD.44.829 PG 8 WC Astronomy & Astrophysics; Physics, Particles & Fields SC Astronomy & Astrophysics; Physics GA FY346 UT WOS:A1991FY34600028 ER PT J AU PAPADIMITRIOU, V BARKER, A BRIERE, RA GIBBONS, LK MAKOFF, G PATTERSON, JR SOMALWAR, S WAH, YW WINSTEIN, B WINSTON, R WOODS, M YAMAMOTO, H SWALLOW, EC BOCK, GJ COLEMAN, R ENAGONIO, J HSIUNG, YB RAMBERG, E STANFIELD, K TSCHIRHART, R YAMANAKA, T GOLLIN, GD KARLSSON, M OKAMITSU, JK DEBU, P PEYAUD, B TURLAY, R VALLAGE, B AF PAPADIMITRIOU, V BARKER, A BRIERE, RA GIBBONS, LK MAKOFF, G PATTERSON, JR SOMALWAR, S WAH, YW WINSTEIN, B WINSTON, R WOODS, M YAMAMOTO, H SWALLOW, EC BOCK, GJ COLEMAN, R ENAGONIO, J HSIUNG, YB RAMBERG, E STANFIELD, K TSCHIRHART, R YAMANAKA, T GOLLIN, GD KARLSSON, M OKAMITSU, JK DEBU, P PEYAUD, B TURLAY, R VALLAGE, B TI MEASUREMENT OF THE BRANCHING RATIO OF THE DECAY KL-]PI-0-GAMMA-GAMMA SO PHYSICAL REVIEW D LA English DT Note AB Using the complete Fermilab E731 data set, we find GAMMA(K(L) --> pi-0-gamma-gamma, m-gamma-gamma greater-than-or-equal-to 0.280 GeV/GAMMA(K(L) --> all) = (1.86 +/- 0.60 +/- 0.60) x 10(-6), in good agreement with a recent report of the first observation of this decay. For the low-gamma-gamma-mass region we find GAMMA(K(L) --> pi-0-gamma-gamma, m-gamma-gamma < 0.264 GeV/GAMMA(K(L) --> all) < 5.1 x 10(-6) (90% confidence). C1 UNIV CHICAGO,ENRICO FERMI INST,CHICAGO,IL 60637. UNIV CHICAGO,DEPT PHYS,CHICAGO,IL 60637. ELMHURST COLL,DEPT PHYS,ELMHURST,IL 60126. PRINCETON UNIV,DEPT PHYS,PRINCETON,NJ 08544. CENS,DEPT PHYS PARTICULES ELEMENTAIRES,F-91191 GIF SUR YVETTE,FRANCE. RP PAPADIMITRIOU, V (reprint author), FERMI NATL ACCELERATOR LAB,BATAVIA,IL 60510, USA. RI Briere, Roy/N-7819-2014 OI Briere, Roy/0000-0001-5229-1039 NR 11 TC 17 Z9 17 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 AUG 1 PY 1991 VL 44 IS 3 BP R573 EP R576 DI 10.1103/PhysRevD.44.R573 PG 4 WC Astronomy & Astrophysics; Physics, Particles & Fields SC Astronomy & Astrophysics; Physics GA FY346 UT WOS:A1991FY34600001 ER PT J AU EBERT, WL HOBURG, RF BATES, JK AF EBERT, WL HOBURG, RF BATES, JK TI THE SORPTION OF WATER ON OBSIDIAN AND A NUCLEAR WASTE GLASS SO PHYSICS AND CHEMISTRY OF GLASSES LA English DT Article ID HYDRATION AB The sorption isotherms for water on obsidian and a simulated nuclear waste glass were collected at 23-degrees-C. The general shapes of the isotherms are similar to those of water on simple silicates and other oxides and are dominated by the condensation of water above about 95% relative humidity. In a vapour environment, the vapour pressure controls both the amount of water available and the driving force for subsequent reaction with the glass such as diffusion into the glass or ion exchange. The diffusion of water into obsidian at 23-degrees-C, for example, proceeds at a rate of near 5-mu-m2/1000 yr at 84% relative humidity but only about 3-mu-m2/1000 yr at 58% relative humidity. The influence of the vapour pressure (or relative humidity) in both the laboratory and terrestrial environment must be accounted for before experimentally determined reaction rates can be projected backward when age dating obsidian artefacts or forward when projecting long term glass durabilities. RP EBERT, WL (reprint author), ARGONNE NATL LAB,DIV CHEM TECHNOL,9700 S CASS AVE,ARGONNE,IL 60439, USA. NR 25 TC 14 Z9 14 U1 0 U2 2 PU SOC GLASS TECHNOLOGY PI SHEFFIELD PA THORNTON 20 HALLAM GATE ROAD, SHEFFIELD, S YORKSHIRE, ENGLAND S10 5BT SN 0031-9090 J9 PHYS CHEM GLASSES JI Phys. Chem. Glasses PD AUG PY 1991 VL 32 IS 4 BP 133 EP 137 PG 5 WC Chemistry, Physical; Materials Science, Ceramics SC Chemistry; Materials Science GA GA648 UT WOS:A1991GA64800001 ER PT J AU Adams, DL Akchurin, N Belikov, NI Bonner, BE Buchanan, JA Bystricky, J Clement, JM Corcoran, MD Cossairt, JD Cranshaw, J Derevschikov, AA En'yo, H Funahashi, H Goto, Y Grachov, OA Grosnick, DP Hill, DA Imai, K Itow, Y Iwatani, K Krueger, KW Kuroda, K Langland, J Lehar, F de Lesquen, A Lopiano, D Luehring, FC Maki, T Makino, S Masaike, A Matulenko, YA Meschanin, AP Michalowicz, A Miller, DH Miyake, K Nagamine, T Nessi-Tedaldi, F Nessi, M Nguyen, C Nurushev, SB Ohashi, Y Onel, Y Patalakha, DI Pauletta, G Penzo, A Phillips, GC Read, AL Roberts, JB van Rossum, L Rykov, VL Saito, N Salvato, G Schiavon, P Skeens, J Solovyanov, VL Spinka, H Stanek, RW Takashima, R Takeutchi, F Tamura, N Tanaka, N Underwood, DG Vasiliev, AN Villari, A White, JL Yamashita, S Yokosawa, A Yoshida, T Zanetti, A AF Adams, DL Akchurin, N Belikov, NI Bonner, BE Buchanan, JA Bystricky, J Clement, JM Corcoran, MD Cossairt, JD Cranshaw, J Derevschikov, AA En'yo, H Funahashi, H Goto, Y Grachov, OA Grosnick, DP Hill, DA Imai, K Itow, Y Iwatani, K Krueger, KW Kuroda, K Langland, J Lehar, F de Lesquen, A Lopiano, D Luehring, FC Maki, T Makino, S Masaike, A Matulenko, YA Meschanin, AP Michalowicz, A Miller, DH Miyake, K Nagamine, T Nessi-Tedaldi, F Nessi, M Nguyen, C Nurushev, SB Ohashi, Y Onel, Y Patalakha, DI Pauletta, G Penzo, A Phillips, GC Read, AL Roberts, JB van Rossum, L Rykov, VL Saito, N Salvato, G Schiavon, P Skeens, J Solovyanov, VL Spinka, H Stanek, RW Takashima, R Takeutchi, F Tamura, N Tanaka, N Underwood, DG Vasiliev, AN Villari, A White, JL Yamashita, S Yokosawa, A Yoshida, T Zanetti, A TI ANALYZING POWER IN INCLUSIVE PI+ AND PI- PRODUCTION AT HIGH CHI-F WITH A 200 GEV POLARIZED PROTON-BEAM SO PHYSICS LETTERS B LA English DT Article ID HYPERON POLARIZATION; HADRON-PRODUCTION; SPIN ASYMMETRY; 18.5 GEV/C; SUM-RULE; SCATTERING; BERYLLIUM AB The analyzing power in inclusive charged pion production has been measured using the 200 GeV Fermilab polarized proton beam. A striking dependence in x(F) is observed in which A(N) increases from 0 to 0.42 with increasing x(F) for the pi+ data and decreases from 0 to -0.38 with increasing x(F) for pi- data. The kinematic range covered is 0.2 less-than-or-equal-to x(F) less-than-or-equal-to 0.9 and 0.2 less-than-or-equal-to p(T) 2.0 GeV/c. In a simple model our data indicate that at large x(F) the transverse spin of the proton is correlated with that of its quark constituents. C1 Rice Univ, TW Bonner Nucl Lab, Houston, TX 77251 USA. Univ Iowa, Dept Phys, Iowa City, IA 52242 USA. Inst High Energy Phys, Serpukhov, RUSSIA. CENS, F-91191 Gif Sur Yvette, FRANCE. Fermi Natl Accelerator Lab, Batavia, IL 60510 USA. Kyoto Univ, Dept Phys, Kyoto 606, JAPAN. Argonne Natl Lab, Argonne, IL 60439 USA. Hiroshima Univ, Higashi Ku, Hiroshima 724, JAPAN. NE State Univ, Talequah, OK 74464 USA. Lab Phys Particules, F-74017 Annecy Le Vieux, FRANCE. Northwestern Univ, Dept Phys, Evanston, IL 60201 USA. Univ Occupat & Environm Hlth, Kitakyushu, Fukuoka 807, JAPAN. Univ Udine, I-33100 Udine, ITALY. Univ Trieste, Dipartimento Fis, I-34100 Trieste, ITALY. Univ Messina, Dipartimento Fis, I-98100 Messina, ITALY. Kyoto Univ Educ, Kyoto 612, JAPAN. Kyoto Sangyo Univ, Kyoto 612, JAPAN. Okayama Univ, Okayama 700, JAPAN. Univ Calif Los Alamos Natl Lab, Los Alamos, NM 87545 USA. Osaka City Univ, Osaka 558, JAPAN. RP Adams, DL (reprint author), Rice Univ, TW Bonner Nucl Lab, Houston, TX 77251 USA. RI En'yo, Hideto/B-2440-2015 NR 24 TC 356 Z9 357 U1 0 U2 6 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 1 PY 1991 VL 264 IS 3-4 BP 462 EP 466 DI 10.1016/0370-2693(91)90378-4 PG 5 WC Astronomy & Astrophysics; Physics, Nuclear; Physics, Particles & Fields SC Astronomy & Astrophysics; Physics GA GB760 UT WOS:A1991GB76000039 ER PT J AU DECAMP, D DESCHIZEAUX, B GOY, C LEES, JP MINARD, MN ALEMANY, R CRESPO, JM DELFINO, M FERNANDEZ, E GAITAN, V GARRIDO, L MIR, LM PACHECO, A CATANESI, MG CREANZA, D DE PALMA, M FARILLA, A IASELLI, G MAGGI, G MAGGI, M NATALI, S NUZZO, S QUATTROMINI, M RANIERI, A RASO, G ROMANO, F RUGGIERI, F SELVAGGI, G SILVESTRIS, L TEMPESTA, P ZITO, G GAO, Y HU, H HUANG, D HUANG, X LIN, J LOU, J QIAO, C RUAN, T WANG, T XIE, Y XU, D XU, R ZHANG, J ZHAO, W ATWOOD, WB BAUERDICK, LAT BIRD, F BLUCHER, E BONVICINI, G BOSSI, F BOUDREAU, J BROWN, D BURNETT, TH DREVERMANN, H FORTY, RW GRAB, C HAGELBERG, R HAYWOOD, S HILGART, J JOST, B KASEMANN, M KNOBLOCH, J LACOURT, A LANCON, E LEHRAUS, I LOHSE, T LUSIANI, A MARCHIORO, A MARTINEZ, M MATO, P MENARY, S MINTEN, A MIOTTO, A MIQUEL, R MOSER, HG NASH, J PALAZZI, P RANJARD, F REDLINGER, G ROTH, A ROTHBERG, J ROTSHEIDT, H SAICH, M ST DENIS, R SCHLATTER, D TAKASHIMA, M TALBY, M TEJESSY, W WACHSMUTH, H WASSERBAECH, S WHEELER, S WIEDENMANN, W WITZELING, W WOTSCHACK, J AJALTOUNI, Z BARDADIN-OTWINOWSKA, M EL FELLOUS, R FALVARD, A GAY, P HARVEY, J HENRARD, P JOUSSET, J MICHEL, B MONTRET, JC PALLIN, D PERRET, P PRORIOL, J PRULHIERE, F STIMPFL, G HANSEN, JD HANSEN, JR HANSEN, PH MOLLERUD, R NILSSON, BS EFTHYMIOPOULOS, I SIMOPOULOU, E VAYAKI, A BADIER, J BLONDEL, A BONNEAUD, G BOUROTTE, J BRAEMS, F BRIENT, JC FOUQUE, G GAMESS, A GUIRLET, R ORTEU, S ROSOWSKY, A ROUGE, A RUMPF, M TANAKA, R VIDEAU, H CANDLIN, DJ VEITCH, E PARRINI, G CORDEN, M GEORGIOPOULOS, C IKEDA, M LANNUTTI, J LEVINTHAL, D MERMIKIDES, M SAWYER, L ANTONELLI, A BALDINI, R BENCIVENNI, G BOLOGNA, G CAMPANA, P CAPON, G CERUTTI, F CHIARELLA, V D'ETTORRE-PIAZZOLI, B FELICI, G LAURELLI, P MANNOCCHI, G MURTAS, F MURTAS, GP NICOLETTI, G PASSALACQUA, L PEPE-ALTARELLI, M PICCHI, P ZOGRAFOU, P ALTOON, B BOYLE, O HALLEY, AW TEN HAVE, I HEARNS, JL LYNCH, JG MORTON, WT RAINE, C SCARR, JM SMITH, K THOMPSON, AS TURNBULL, RM BRANDL, B BRAUN, O GEIGES, R GEWENIGER, C HANKE, P HEPP, V KLUGE, EE MAUMARY, Y PUTZER, A RENSCH, B STAHL, A TITTEL, K WUNSCH, M BELK, AT BEUSELINCK, R BINNIE, DM CAMERON, W CATTANEO, M DORNAN, PJ DUGEAY, S GREENE, AM HASSARD, JF LIESKE, NM PATTON, SJ PAYNE, DG PHILLIPS, MJ SEDGBEER, JK TAYLOR, G TOMALIN, IR WRIGHT, AG GIRTLER, P KUHN, D RUDOLPH, G BOWDERY, CK BRODBECK, TJ FINCH, AJ FOSTER, F HUGHES, G KEEMER, NR NUTTALL, M PATEL, A ROWLINGSON, BS SLOAN, T SNOW, SW WHELAN, EP BARCZEWSKI, T KLEINKNECHT, K RAAB, J RENK, B ROEHN, S SANDER, HG SCHMELLING, M SCHMIDT, H STEEG, F WALTHER, SM WOLF, B ALBANESE, JP AUBERT, JJ BENCHOUK, C BERNARD, V BONISSENT, A COURVOISIER, D ETIENNE, F PAPALEXIOU, S PAYRE, P PIETRZYK, B QIAN, Z BECKER, H BLUM, W CATTANEO, P COWAN, G DEHNING, B DIETL, H DYDAK, F FERNANDEZ-BOSMAN, M HANSL-KOZANECKA, T JAHN, A KOZANECKI, W LANGE, E LAUBER, J LUTJENS, G LUTZ, G MANNER, W PAN, Y RICHTER, R SCHRODER, J SCHWARZ, AS SETTLES, R STIERLIN, U THOMAS, J WOLF, G BERTIN, V BOURCROT, J CALLOT, O CHEN, X CORDIER, A DAVIER, M GANIS, G GRIVAZ, JF HEUSSE, P JANOT, P KIM, DW LE DIBERDER, F LEFRANCOIS, J LUTZ, AM VEILLET, JJ VIDEAU, I ZHANG, Z ZOMER, F ABBANEO, D AMENDOLIA, SR BAGLIESI, G BATIGNANI, G BOSISIO, L BOTTIGLI, U BRADASCHIA, C CARPINELLI, M CIOCCI, MA DELL'ORSO, R FERRANTE, I FIDECARO, F FOA, L FOCARDI, E FORTI, F GIASSI, A GIORGI, MA LIGABUE, F MANNELLI, EB MARROCCHESI, PS MESSINEO, A MONETA, L PALLA, F SANGUINETTI, G STEINBERGER, J TECCHINI, R TONELLI, G TRIGGIANI, G VANNINI, C VENTURI, A VERDINI, PG WALSH, J CARTER, JM GREEN, MG MARCH, PV MEDCALF, T QUASI, IS STRONG, JA THOMAS, RM WEST, LR WILDISH, T BOTTERILL, DR CLIFFT, RW EDGECOCK, TR EDWARDS, M FISHER, SM JONES, TJ NORTON, PR SALMON, DP THOMPSON, JC BLOCH-DEVAUX, B COLAS, P KLOPFENSTEIN, C LOCCI, E LOUCATOS, S MONNIER, E PEREZ, P PERLAS, JA PERRIER, F RANDER, J RENARDY, JF ROUSSARIE, A SCHULLER, JP SCHWINDLING, J VALLAGE, B ASHMAN, JG BOOTH, CN BUTTAR, C CARNEY, R CARTWRIGHT, S COMBLEY, F DINSDALE, M DOGRU, M HATFIELD, F MARTIN, J PARKER, D REEVES, P THOMPSON, LF BARBERIO, E BRANDT, S BURKHARDT, H GRUPEN, C MEINHARD, H MIRABITO, L SCHAFER, U SEYWERD, H APOLLINARI, G GIANNINI, G GOBBO, B LIELLO, F RAGUSA, F ROLANDI, L STIEGLER, U BELLANTONI, L CHEN, X CINABRO, D CONWAY, JS COWEN, DF FENG, Z FERGUSON, DPS GAO, YS GRAHL, J HARTON, JL JACOBSEN, JE JARED, RC JOHNSON, RP LECLAIRE, BW PAN, YB PATER, JR SAADI, Y SHARMA, V SHI, ZH TANG, YH WALSH, AM WEAR, JA WEBER, FV WHITNEY, MH WU, SL ZOBERNIG, G AF DECAMP, D DESCHIZEAUX, B GOY, C LEES, JP MINARD, MN ALEMANY, R CRESPO, JM DELFINO, M FERNANDEZ, E GAITAN, V GARRIDO, L MIR, LM PACHECO, A CATANESI, MG CREANZA, D DE PALMA, M FARILLA, A IASELLI, G MAGGI, G MAGGI, M NATALI, S NUZZO, S QUATTROMINI, M RANIERI, A RASO, G ROMANO, F RUGGIERI, F SELVAGGI, G SILVESTRIS, L TEMPESTA, P ZITO, G GAO, Y HU, H HUANG, D HUANG, X LIN, J LOU, J QIAO, C RUAN, T WANG, T XIE, Y XU, D XU, R ZHANG, J ZHAO, W ATWOOD, WB BAUERDICK, LAT BIRD, F BLUCHER, E BONVICINI, G BOSSI, F BOUDREAU, J BROWN, D BURNETT, TH DREVERMANN, H FORTY, RW GRAB, C HAGELBERG, R HAYWOOD, S HILGART, J JOST, B KASEMANN, M KNOBLOCH, J LACOURT, A LANCON, E LEHRAUS, I LOHSE, T LUSIANI, A MARCHIORO, A MARTINEZ, M MATO, P MENARY, S MINTEN, A MIOTTO, A MIQUEL, R MOSER, HG NASH, J PALAZZI, P RANJARD, F REDLINGER, G ROTH, A ROTHBERG, J ROTSHEIDT, H SAICH, M ST DENIS, R SCHLATTER, D TAKASHIMA, M TALBY, M TEJESSY, W WACHSMUTH, H WASSERBAECH, S WHEELER, S WIEDENMANN, W WITZELING, W WOTSCHACK, J AJALTOUNI, Z BARDADIN-OTWINOWSKA, M EL FELLOUS, R FALVARD, A GAY, P HARVEY, J HENRARD, P JOUSSET, J MICHEL, B MONTRET, JC PALLIN, D PERRET, P PRORIOL, J PRULHIERE, F STIMPFL, G HANSEN, JD HANSEN, JR HANSEN, PH MOLLERUD, R NILSSON, BS EFTHYMIOPOULOS, I SIMOPOULOU, E VAYAKI, A BADIER, J BLONDEL, A BONNEAUD, G BOUROTTE, J BRAEMS, F BRIENT, JC FOUQUE, G GAMESS, A GUIRLET, R ORTEU, S ROSOWSKY, A ROUGE, A RUMPF, M TANAKA, R VIDEAU, H CANDLIN, DJ VEITCH, E PARRINI, G CORDEN, M GEORGIOPOULOS, C IKEDA, M LANNUTTI, J LEVINTHAL, D MERMIKIDES, M SAWYER, L ANTONELLI, A BALDINI, R BENCIVENNI, G BOLOGNA, G CAMPANA, P CAPON, G CERUTTI, F CHIARELLA, V D'ETTORRE-PIAZZOLI, B FELICI, G LAURELLI, P MANNOCCHI, G MURTAS, F MURTAS, GP NICOLETTI, G PASSALACQUA, L PEPE-ALTARELLI, M PICCHI, P ZOGRAFOU, P ALTOON, B BOYLE, O HALLEY, AW TEN HAVE, I HEARNS, JL LYNCH, JG MORTON, WT RAINE, C SCARR, JM SMITH, K THOMPSON, AS TURNBULL, RM BRANDL, B BRAUN, O GEIGES, R GEWENIGER, C HANKE, P HEPP, V KLUGE, EE MAUMARY, Y PUTZER, A RENSCH, B STAHL, A TITTEL, K WUNSCH, M BELK, AT BEUSELINCK, R BINNIE, DM CAMERON, W CATTANEO, M DORNAN, PJ DUGEAY, S GREENE, AM HASSARD, JF LIESKE, NM PATTON, SJ PAYNE, DG PHILLIPS, MJ SEDGBEER, JK TAYLOR, G TOMALIN, IR WRIGHT, AG GIRTLER, P KUHN, D RUDOLPH, G BOWDERY, CK BRODBECK, TJ FINCH, AJ FOSTER, F HUGHES, G KEEMER, NR NUTTALL, M PATEL, A ROWLINGSON, BS SLOAN, T SNOW, SW WHELAN, EP BARCZEWSKI, T KLEINKNECHT, K RAAB, J RENK, B ROEHN, S SANDER, HG SCHMELLING, M SCHMIDT, H STEEG, F WALTHER, SM WOLF, B ALBANESE, JP AUBERT, JJ BENCHOUK, C BERNARD, V BONISSENT, A COURVOISIER, D ETIENNE, F PAPALEXIOU, S PAYRE, P PIETRZYK, B QIAN, Z BECKER, H BLUM, W CATTANEO, P COWAN, G DEHNING, B DIETL, H DYDAK, F FERNANDEZ-BOSMAN, M HANSL-KOZANECKA, T JAHN, A KOZANECKI, W LANGE, E LAUBER, J LUTJENS, G LUTZ, G MANNER, W PAN, Y RICHTER, R SCHRODER, J SCHWARZ, AS SETTLES, R STIERLIN, U THOMAS, J WOLF, G BERTIN, V BOURCROT, J CALLOT, O CHEN, X CORDIER, A DAVIER, M GANIS, G GRIVAZ, JF HEUSSE, P JANOT, P KIM, DW LE DIBERDER, F LEFRANCOIS, J LUTZ, AM VEILLET, JJ VIDEAU, I ZHANG, Z ZOMER, F ABBANEO, D AMENDOLIA, SR BAGLIESI, G BATIGNANI, G BOSISIO, L BOTTIGLI, U BRADASCHIA, C CARPINELLI, M CIOCCI, MA DELL'ORSO, R FERRANTE, I FIDECARO, F FOA, L FOCARDI, E FORTI, F GIASSI, A GIORGI, MA LIGABUE, F MANNELLI, EB MARROCCHESI, PS MESSINEO, A MONETA, L PALLA, F SANGUINETTI, G STEINBERGER, J TECCHINI, R TONELLI, G TRIGGIANI, G VANNINI, C VENTURI, A VERDINI, PG WALSH, J CARTER, JM GREEN, MG MARCH, PV MEDCALF, T QUASI, IS STRONG, JA THOMAS, RM WEST, LR WILDISH, T BOTTERILL, DR CLIFFT, RW EDGECOCK, TR EDWARDS, M FISHER, SM JONES, TJ NORTON, PR SALMON, DP THOMPSON, JC BLOCH-DEVAUX, B COLAS, P KLOPFENSTEIN, C LOCCI, E LOUCATOS, S MONNIER, E PEREZ, P PERLAS, JA PERRIER, F RANDER, J RENARDY, JF ROUSSARIE, A SCHULLER, JP SCHWINDLING, J VALLAGE, B ASHMAN, JG BOOTH, CN BUTTAR, C CARNEY, R CARTWRIGHT, S COMBLEY, F DINSDALE, M DOGRU, M HATFIELD, F MARTIN, J PARKER, D REEVES, P THOMPSON, LF BARBERIO, E BRANDT, S BURKHARDT, H GRUPEN, C MEINHARD, H MIRABITO, L SCHAFER, U SEYWERD, H APOLLINARI, G GIANNINI, G GOBBO, B LIELLO, F RAGUSA, F ROLANDI, L STIEGLER, U BELLANTONI, L CHEN, X CINABRO, D CONWAY, JS COWEN, DF FENG, Z FERGUSON, DPS GAO, YS GRAHL, J HARTON, JL JACOBSEN, JE JARED, RC JOHNSON, RP LECLAIRE, BW PAN, YB PATER, JR SAADI, Y SHARMA, V SHI, ZH TANG, YH WALSH, AM WEAR, JA WEBER, FV WHITNEY, MH WU, SL ZOBERNIG, G TI MEASUREMENT OF ISOLATED PHOTON PRODUCTION IN HADRONIC Z-DECAYS SO PHYSICS LETTERS B LA English DT Article ID ENERGIES; LEP AB The production of high energy isolated photons in hadronic Z decays is measured with the ALEPH detector at LEP using a sample of 180 000 hadronic events. Such photons are mainly radiated by quarks, thus giving direct insights into the early parton showering mechanism. The observed rate is compared with a QCD calculation of final state radiation from quarks. C1 CNRS, IN2P3, LAB PHYS PARTICULES LAPP, F-74019 ANNECY LE VIEUX, FRANCE. UNIV AUTONOMA BARCELONA, LAB FIS ALTAS ENERGIAS, E-08193 BARCELONA, SPAIN. IST NAZL FIS NUCL, SEZ BARI, I-70126 BARI, ITALY. IST NAZL FIS NUCL, DIPARTIMENTO FIS UNIV, I-70126 BARI, ITALY. ACAD SINICA, INST HIGH ENERGY PHYS, BEIJING, PEOPLES R CHINA. CERN, EUROPEAN LAB PARTICLE PHYS, CH-1211 GENEVA 23, SWITZERLAND. UNIV BLAISE PASCAL, CNRS, IN2P3, LAB PHYS CORPUSCULAIRE, F-63177 AUBIERE, FRANCE. NIELS BOHR INST, DK-2100 COPENHAGEN, DENMARK. NUCL RES CTR DEMOKRITOS NRCD, ATHENS, GREECE. ECOLE POLYTECH, CNRS, IN2P3, LAB PHYS NUCL & HAUTES ENERGIES, F-91128 PALAISEAU, FRANCE. UNIV EDINBURGH, DEPT PHYS, EDINBURGH EH9 3JZ, ENGLAND. UNIV FIRENZE, DIPARTIMENTO FIS, I-50125 FLORENCE, ITALY. IST NAZL FIS NUCL, SEZ FIRENZE, I-50125 FLORENCE, ITALY. FLORIDA STATE UNIV, SUPERCOMP COMPUTAT RES INST, TALLAHASSEE, FL 32306 USA. FLORIDA STATE UNIV, DEPT PHYS, TALLAHASSEE, FL 32306 USA. IST NAZL FIS NUCL, LNF, I-00044 FRASCATI, ITALY. UNIV GLASGOW, DEPT PHYS & ASTRON, GLASGOW G12 8QQ, LANARK, SCOTLAND. UNIV HEIDELBERG, INST HOCHENERGIEPHYS, W-6900 HEIDELBERG, GERMANY. IMPERIAL COLL, DEPT PHYS, LONDON SW7 2BZ, ENGLAND. UNIV INNSBRUCK, INST EXPT PHYS, A-6020 INNSBRUCK, AUSTRIA. UNIV LANCASTER, DEPT PHYS, LANCASTER LA1 4YB, ENGLAND. UNIV MAINZ, INST PHYS, W-6500 MAINZ, GERMANY. CNRS, IN2P3, FAC SCI LUMINY, CTR PHYS PARTICULES, F-13288 MARSEILLE, FRANCE. WERNER HEISENBERG INST PHYS, MAX PLANCK INST PHYS & ASTROPHYS, W-8000 MUNICH, GERMANY. UNIV PARIS SUD, CNRS, IN2P3, LAB ACCELERATEUR LINEAIRE, F-91405 ORSAY, FRANCE. UNIV PISA, DIPARTIMENTO FIS, INFN, SEZ PISA, I-56010 PISA, ITALY. SCUOLA NORMALE SUPER, I-56010 PISA, ITALY. UNIV LONDON, ROYAL HOLLOWAY & BEDFORD NEW COLL, DEPT PHYS, Surrey TW20 0EX, ENGLAND. RUTHERFORD APPLETON LAB, PARTICLE PHYS DEPTZ, DIDCOT OX11 0QX, OXON, ENGLAND. CEN SACLAY, DEPT PHYS PARTICULES ELEMENTAIRES, F-91191 GIF SUR YVETTE, FRANCE. UNIV SHEFFIELD, DEPT PHYS, SHEFFIELD S3 7RH, ENGLAND. UNIV SIEGEN, FACHBEREICH PHYS, W-5900 SIEGEN, GERMANY. UNIV TRIESTE, DIPARTIMENTO FIS, I-34127 TRIESTE, ITALY. IST NAZL FIS NUCL, SEZ TRIESTE, I-34127 TRIESTE, ITALY. UNIV WISCONSIN, DEPT PHYS, MADISON, WI 53706 USA. SLAC, Stanford, CA 94309 USA. UNIV WASHINGTON, SEATTLE, WA 98195 USA. FAC SCI, CTR PHYS PARTICULES, F-13288 MARSEILLE, FRANCE. UNIV TORINO, IST FIS GEN, TURIN, ITALY. CNR, IST COSMO GEOFIS, I-10133 TURIN, ITALY. CERN, PPE DIV, CH-1211 Geneva 23, SWITZERLAND. LBL, Berkeley, CA 94720 USA. RP DECAMP, D (reprint author), CNRS, IN2P3, LAB PHYS PARTICULES LAPP, F-74019 ANNECY LE VIEUX, FRANCE. RI Murtas, Fabrizio/B-5729-2012; Booth, Christopher/B-5263-2016; Delfino, Manuel/A-1545-2012; Pacheco Pages, Andres/C-5353-2011; Ferrante, Isidoro/F-1017-2012; Ligabue, Franco/F-3432-2014; Forti, Francesco/H-3035-2011; Lusiani, Alberto/A-3329-2016; Venturi, Andrea/J-1877-2012; Perrier, Frederic/A-5953-2011; Rolandi, Luigi (Gigi)/E-8563-2013; Colas, Paul/F-2876-2013; Bosman, Martine/J-9917-2014; Fernandez, Enrique/L-5387-2014; Mir, Lluisa-Maria/G-7212-2015; ciocci, maria agnese /I-2153-2015; Lusiani, Alberto/N-2976-2015; Marrocchesi, Pier Simone/N-9068-2015 OI Murtas, Fabrizio/0000-0002-7041-6541; Garrido Beltran, Lluis/0000-0001-8883-6539; Edgecock, Rob/0000-0002-7896-3312; Miquel, Ramon/0000-0002-6610-4836; Booth, Christopher/0000-0002-6051-2847; Delfino, Manuel/0000-0002-9468-4751; Pacheco Pages, Andres/0000-0001-8210-1734; Ferrante, Isidoro/0000-0002-0083-7228; Palazzi, Paolo/0000-0002-4861-391X; RASO, Giuseppe/0000-0002-5660-3711; Bottigli, Ubaldo/0000-0002-0666-3433; Ligabue, Franco/0000-0002-1549-7107; Bloch-Devaux, Brigitte/0000-0002-2463-1232; Forti, Francesco/0000-0001-6535-7965; Lusiani, Alberto/0000-0002-6876-3288; Rolandi, Luigi (Gigi)/0000-0002-0635-274X; Bosman, Martine/0000-0002-7290-643X; Fernandez, Enrique/0000-0002-6405-9488; Mir, Lluisa-Maria/0000-0002-4276-715X; ciocci, maria agnese /0000-0003-0002-5462; Lusiani, Alberto/0000-0002-6876-3288; Marrocchesi, Pier Simone/0000-0003-1966-140X NR 15 TC 27 Z9 27 U1 0 U2 2 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0370-2693 J9 PHYS LETT B JI Phys. Lett. B PD AUG 1 PY 1991 VL 264 IS 3-4 BP 476 EP 486 DI 10.1016/0370-2693(91)90380-9 PG 11 WC Astronomy & Astrophysics; Physics, Nuclear; Physics, Particles & Fields SC Astronomy & Astrophysics; Physics GA GB760 UT WOS:A1991GB76000041 ER PT J AU NEWCOMB, WA AF NEWCOMB, WA TI MAGNETOHYDRODYNAMIC WAVE DRAG SO PHYSICS OF FLUIDS B-PLASMA PHYSICS LA English DT Article ID COMPACT TOROIDS AB A calculation is made of the energy loss by emission of shear-Alfven and slow magnetoacoustic waves by a perfectly conducting solid spherical projectivle moving with uniform velocity through an ideal magnetoplasma. C1 UNIV CALIF DAVIS,DEPT APPL SCI,DAVIS,CA 95616. RP NEWCOMB, WA (reprint author), UNIV CALIF LAWRENCE LIVERMORE NATL LAB,POB 808,LIVERMORE,CA 94550, USA. NR 5 TC 23 Z9 23 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 AUG PY 1991 VL 3 IS 8 BP 1818 EP 1829 DI 10.1063/1.859651 PN 1 PG 12 WC Physics, Fluids & Plasmas SC Physics GA FY448 UT WOS:A1991FY44800005 ER PT J AU GALVEZ, M BOROVSKY, JE AF GALVEZ, M BOROVSKY, JE TI THE EXPANSION OF POLARIZATION CHARGE LAYERS INTO A MAGNETIZED VACUUM - THEORY AND COMPUTER-SIMULATIONS SO PHYSICS OF FLUIDS B-PLASMA PHYSICS LA English DT Article ID PLASMA; FIELD; MAGNETOSPHERE; PROPAGATION; STREAMS AB When a sufficiently dense plasma stream moves across a magnetic field, the stream will form polarization charge layers and will E X B drift across the field. One charge layer is composed of electrons and the other is composed of ions. The phenomena associated with the expansion of these polarization charge layers along the magnetic field away from the stream is investigated by means of analytic theory and is confirmed by two-dimensional electrostatic particle-in-cell computer simulations. At very early times, the expansion of the electron charge layer is described by single-particle motion in a dipolelike electric field. Eventually, the electron expansion is halted by the net positive charge left behind at the stream. Then an ambipolar expansion of the electron and ion charge layers forms, with the expansion velocity set by the stream voltage rather than by plasma temperatures. Steady decreases in the cross-field-propagation velocities of the streams are observed, owing to the steady losses of charge from the stream edges. C1 UNIV CALIF LOS ALAMOS SCI LAB,SPACE PLASMA PHYS GRP,LOS ALAMOS,NM 87545. UNIV NEW MEXICO,DEPT PHYS & ASTRON,ALBUQUERQUE,NM 87131. NR 12 TC 13 Z9 13 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 AUG PY 1991 VL 3 IS 8 BP 1892 EP 1907 DI 10.1063/1.859658 PN 1 PG 16 WC Physics, Fluids & Plasmas SC Physics GA FY448 UT WOS:A1991FY44800012 ER PT J AU MIZUNO, K DRAKE, RP YOUNG, PE BAHR, R SEKA, W ESTABROOK, KG AF MIZUNO, K DRAKE, RP YOUNG, PE BAHR, R SEKA, W ESTABROOK, KG TI ION-ACOUSTIC PARAMETRIC DECAY INSTABILITY IN LASER-PRODUCED PLASMA WITH VARYING IONIC CHARGE SO PHYSICS OF FLUIDS B-PLASMA PHYSICS LA English DT Article ID 2ND HARMONIC EMISSION AB Studies of the ion acoustic decay instability (IADI) are reported in which the target material of the laser-produced plasma was varied. The IADI was monitored by observing the Stokes peaks of the second-harmonic spectrum. Its threshold was quite low (almost-equal-to 2 x 10(13) W/cm2) even in high-Z plasma. The threshold increased only weakly with Z. On the other hand, the instability intensity decreased strongly with Z, which is attributed to the decrease of the growth rate. A simple theory explains these experimental results reasonably well. C1 UNIV CALIF LAWRENCE LIVERMORE NATL LAB,LIVERMORE,CA 94550. UNIV ROCHESTER,LASER ENERGET LAB,ROCHESTER,NY 14627. RP MIZUNO, K (reprint author), UNIV CALIFORNIA,PLASMA PHYS RES INST,L-418,POB 808,LIVERMORE,CA 94550, USA. RI Drake, R Paul/I-9218-2012 OI Drake, R Paul/0000-0002-5450-9844 NR 22 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 0899-8221 J9 PHYS FLUIDS B-PLASMA PD AUG PY 1991 VL 3 IS 8 BP 1983 EP 1989 DI 10.1063/1.859666 PN 1 PG 7 WC Physics, Fluids & Plasmas SC Physics GA FY448 UT WOS:A1991FY44800020 ER PT J AU MCNEILL, DH GREENE, GJ NEWBURGER, JD OWENS, DK AF MCNEILL, DH GREENE, GJ NEWBURGER, JD OWENS, DK TI SPECTROSCOPIC MEASUREMENTS OF THE PARAMETERS OF THE ABLATION CLOUDS OF DEUTERIUM PELLETS INJECTED INTO TOKAMAKS SO PHYSICS OF FLUIDS B-PLASMA PHYSICS LA English DT Article ID SOLID HYDROGEN PELLET; TEXAS EXPERIMENTAL TOKAMAK; LINE EMISSION RATE; ALCATOR C TOKAMAK; ALPHA-LINE; PLASMA; DISCHARGES; ASDEX; CONFINEMENT; PROFILE AB Spectroscopic measurements have been made of the parameters of the luminous cloud surrounding deuterium pellets injected into the Princeton Large Torus (PLT) [Phys. Rev. Lett. 55, 1398 (1985)] and the Tokamak Fusion Test Reactor (TFTR) [Plasma Physics and Controlled Nuclear Fusion Research (IAEA, Vienna, 1987), Vol. 1, p. 171], with the measurements on the latter described formally here for the first time. The electron densities determined from the Stark broadening of the Balmer alpha and beta lines ranged from 5 x 10(15) -1 x 10(18) cm-3, while the temperatures obtained from the line to continuum intensity ratios and the ratio of the intensities of the Balmer alpha and beta lines ranged from 0.9 to 3 eV. Balmer alpha emission powers as high as 100 kW were measured. The electron temperature (1.5 +/- 0.2 eV) and density (3 +/- 1 x 10(17) cm-3) at the time of maximum emission from intact pellets were essentially the same for the two tokamaks, although the volumes of both the discharges and the pellets were roughly ten times larger in TFTR than in PLT. The data were taken in Ohmically heated plasmas, except for a limited number of discharges in PLT with low-power (approximately half the Ohmic heating power) ion cyclotron heating for which the results are the same as with Ohmic heating alone. Various factors that may influence the results of measurements of this type are discussed, including self-absorption, low-density plasma surrounding the most intense region of an ablation cloud, fluctuations in the emission intensity, and non-Maxwellian electron distributions. The results of the present experiments are similar to measurements of the pellet cloud parameters in other machines. C1 PRINCETON RES FORUM,PRINCETON,NJ 08540. PRINCETON PLASMA PHYS LAB,PRINCETON,NJ 08543. EMERALD SYST,PRINCETON,NJ 08544. NR 65 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 0899-8221 J9 PHYS FLUIDS B-PLASMA PD AUG PY 1991 VL 3 IS 8 BP 1994 EP 2009 DI 10.1063/1.859668 PN 1 PG 16 WC Physics, Fluids & Plasmas SC Physics GA FY448 UT WOS:A1991FY44800022 ER PT J AU CHARLTON, LA LEBOEUF, JN LYNCH, VE AF CHARLTON, LA LEBOEUF, JN LYNCH, VE TI RESISTIVE MAGNETOHYDRODYNAMIC STABILITY OF STELLARATORS WITH INCREASING PLASMA PRESSURE SO PHYSICS OF FLUIDS B-PLASMA PHYSICS LA English DT Article AB A sequence of toroidally averaged stellarator equilibria with increasing values of beta was studied by numerically following the time evolution. It was found that the beta-dependence of many different plasma parameters indicated that this sequence represented plasmas whose resistive stability properties first worsened and then improved with beta-signaling entry into the second stability region. A study of the radial dependence of the stability showed that the plasma was limited in the plasma interior by a mode with a large resistive ballooning component and toward the edge by a resistive interchange mode. RP CHARLTON, LA (reprint author), OAK RIDGE NATL LAB,POB 2009,OAK RIDGE,TN 37831, USA. RI Lynch, Vickie/J-4647-2012 OI Lynch, Vickie/0000-0002-5836-7636 NR 12 TC 2 Z9 2 U1 0 U2 0 PU AMER INST PHYSICS PI WOODBURY PA CIRCULATION FULFILLMENT DIV, 500 SUNNYSIDE BLVD, WOODBURY, NY 11797-2999 SN 0899-8221 J9 PHYS FLUIDS B-PLASMA PD AUG PY 1991 VL 3 IS 8 BP 2028 EP 2037 DI 10.1063/1.859669 PN 1 PG 10 WC Physics, Fluids & Plasmas SC Physics GA FY448 UT WOS:A1991FY44800024 ER PT J AU COWLEY, SC KAW, PK KELLY, RS KULSRUD, RM AF COWLEY, SC KAW, PK KELLY, RS KULSRUD, RM TI AN ANALYTIC SOLUTION OF HIGH-BETA EQUILIBRIUM IN A LARGE ASPECT RATIO TOKAMAK SO PHYSICS OF FLUIDS B-PLASMA PHYSICS LA English DT Article AB An analytic solution of the high-beta (epsilon-beta-pBAR approximately beta-q2/epsilon >> 1) equilibrium of a large aspect ratio tokamak is presented. Two arbitrary flux functions, the pressure profile p(psi) and the safety factor profile q(psi), specify the equilibrium. The solution splits into two asymptotic regions: the core region where psi is a function of the major radius alone and a narrow boundary layer region adjoining the conducting wall. The solutions in the two regions are asymptotically matched to each other. For monotonic pressure profiles, the Shafranov shift is equal to the minor radius. For beta much bigger than 1, the solution contains a region (in place of the magnetic axis) of zero magnetic field and constant pressure. At high beta the quantity beta-I, which is essentially proportional to the pressure over the total current squared, is largely independent of pressure. The important ramifications of limited beta-I for high-beta reactors are discussed. Generalizations to shaped cross sections and hollow pressure profiles are outlined. The problem of equilibrium reconstruction in the high-beta regime is also considered. C1 INST PLASMA RES,GANDINGAR,GUJARAT,INDIA. RP COWLEY, SC (reprint author), PRINCETON PLASMA PHYS LAB,POB 451,PRINCETON,NJ 08543, USA. NR 8 TC 39 Z9 39 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 AUG PY 1991 VL 3 IS 8 BP 2066 EP 2077 DI 10.1063/1.859991 PN 1 PG 12 WC Physics, Fluids & Plasmas SC Physics GA FY448 UT WOS:A1991FY44800028 ER PT J AU GLASSER, AH AF GLASSER, AH TI COMPLETE FLUID EQUATIONS FOR LOW-N SINGULAR MODES IN AXISYMMETRICAL TOROIDAL PLASMAS SO PHYSICS OF FLUIDS B-PLASMA PHYSICS LA English DT Article ID REVERSED-FIELD PINCH; TEARING MODES; TWISTING MODES; KINETIC-THEORY; INSTABILITY; TOKAMAK; STABILIZATION; STABILITY; REGIME AB A system of equations governing the singular region of magnetohydrodynamic (MHD) instabilities in a collisional, axisymmetric toroidal plasma with magnetic shear has been derived from Braginskii's fluid equations. This is an extension of earlier work, incorporating anisotropic resistivity, anisotropic ion viscosity, anisotropic ion and electron thermal conductivity, and diamagnetic and E x B drifts. The equations describe the narrow layer in the neighborhood of a singular surface for tearing and interchange instabilities with low toroidal mode number n. Ordering assumptions allow for the maximum range of physical effects while retaining the principal terms in the earlier work and ensuring the validity of the fluid equations. The equations are complete in the sense that all terms, and only those terms, consistent with this carefully constructed ordering are included. RP GLASSER, AH (reprint author), UNIV CALIF LOS ALAMOS SCI LAB,T-15 GRP,MAIL STOP F-647,POB 1663,LOS ALAMOS,NM 87545, USA. NR 28 TC 7 Z9 7 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 AUG PY 1991 VL 3 IS 8 BP 2078 EP 2095 DI 10.1063/1.859621 PN 1 PG 18 WC Physics, Fluids & Plasmas SC Physics GA FY448 UT WOS:A1991FY44800029 ER PT J AU MAYO, RM KIRSCHENBAUM, LS AF MAYO, RM KIRSCHENBAUM, LS TI NEUTRAL PARTICLE ENERGY ANALYSIS AND CHARGE-EXCHANGE POWER LOSS IN EDGE-DOMINATED SPHEROMAKS SO PHYSICS OF FLUIDS B-PLASMA PHYSICS LA English DT Article ID MESH FLUX CONSERVERS; CONFINEMENT; PLASMAS; RELAXATION; TRANSPORT; BALANCE; CODE AB Neutral particle density profiles have previously been calculated for spheromak plasmas [Phys. Fluids B2 (1990) 115]. Here, the formalism is extended to calculate the one-dimensional (1-D) profile of the egressing neutral energy flux to correctly treat profile and attenuation effects. If is found that the energy flux profile is strongly dependent on T(i),T(e),n(e) profiles and magnitudes, and regions of the plasma have been identified as localized "hot spots" for charge-exchange power loss in some cases. In addition, the total charge exchange power loss is found to be in order-of-magnitude agreement with predictions from a zero-dimensional (0-D) model and can account for the bulk of the edge-dominated spheromak power loss. C1 UNIV CALIF LOS ALAMOS SCI LAB,LOS ALAMOS,NM 87544. NR 10 TC 7 Z9 7 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 AUG PY 1991 VL 3 IS 8 BP 2096 EP 2100 DI 10.1063/1.859989 PN 1 PG 5 WC Physics, Fluids & Plasmas SC Physics GA FY448 UT WOS:A1991FY44800030 ER PT J AU OTTAVIANI, M BOWMAN, JC KROMMES, JA AF OTTAVIANI, M BOWMAN, JC KROMMES, JA TI ADVANCES IN THE ANALYTICAL THEORY OF PLASMA TURBULENCE AND TRANSPORT - REALIZABLE MARKOVIAN STATISTICAL CLOSURES SO PHYSICS OF FLUIDS B-PLASMA PHYSICS LA English DT Article ID VORTICES AB Explaining anomalous plasma transport in magnetic confinement devices requires a deeper understanding of the underlying turbulent processes than presently exists. In this work, Markovian closures are built by imposing the constraints of realizability, conservation of quadratic invariants, and covariance to arbitrary linear transformations. One such closure is solved numerically. The results compare favorably to the data available from numerical simulations. C1 PRINCETON UNIV,PLASMA PHYS LAB,POB 451,PRINCETON,NJ 08543. NR 20 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 0899-8221 J9 PHYS FLUIDS B-PLASMA PD AUG PY 1991 VL 3 IS 8 BP 2186 EP 2191 DI 10.1063/1.859634 PN 2 PG 6 WC Physics, Fluids & Plasmas SC Physics GA FY451 UT WOS:A1991FY45100006 ER PT J AU TANAKA, S HANADA, K TANAKA, H IIDA, M IDE, S MINAMI, T NAKAMURA, M MAEKAWA, T TERUMICHI, Y YAMADA, M MANICKAM, J WHITE, RB AF TANAKA, S HANADA, K TANAKA, H IIDA, M IDE, S MINAMI, T NAKAMURA, M MAEKAWA, T TERUMICHI, Y YAMADA, M MANICKAM, J WHITE, RB TI SAWTOOTH STABILIZATION BY ELECTRON-CYCLOTRON HEATING AT THE Q = 1 SURFACE IN THE WT-3 TOKAMAK SO PHYSICS OF FLUIDS B-PLASMA PHYSICS LA English DT Article ID ENERGETIC TRAPPED-PARTICLES; HYBRID CURRENT DRIVE; OSCILLATIONS; SUPPRESSION AB Sawtooth oscillations (STO) in the Ohmically heated (OH) WT-3 tokamak [Plasma Physics and Controlled Nuclear Fusion Research 1988 (IAEA, Vienna, 1989), Vol. 1, p. 563] are strongly modified or suppressed by localized electron cyclotron resonance heating (ECH) near the q = 1 surface, where q refers to the safety factor. The effect of ECH is much stronger when it is applied on the high-field side, as compared to the low-field side. Complete suppression of the STO is achieved for the duration of the ECH when it is applied on the high-field side, in a low-density plasma, provided the ECH power exceeds a threshold value. This threshold decreases with the increasing safety factor at the limiter q(L) and the complete stabilization of STO can be obtained even when ECH is applied on the low-field side in the high-q(L) region. It is noticeable that these complete stabilizations can be obtained only the localized ECH with the elliptic antenna. The STO stabilization is attributed to a modification of the current density profile by high-energy electrons generated by ECH, which reduces the shear in the q = 1 region. C1 PRINCETON UNIV,PLASMA PHYS LAB,PRINCETON,NJ 08543. RP TANAKA, S (reprint author), KYOTO UNIV,FAC SCI,DEPT PHYS,KYOTO 606,JAPAN. RI White, Roscoe/D-1773-2013 OI White, Roscoe/0000-0002-4239-2685 NR 15 TC 5 Z9 5 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 AUG PY 1991 VL 3 IS 8 BP 2200 EP 2204 DI 10.1063/1.859636 PN 2 PG 5 WC Physics, Fluids & Plasmas SC Physics GA FY451 UT WOS:A1991FY45100008 ER PT J AU TUSZEWSKI, M BARNES, DC REJ, DJ TAGGART, DP AF TUSZEWSKI, M BARNES, DC REJ, DJ TAGGART, DP TI STABILITY AND COMPRESSIONAL HEATING OF LARGE FIELD-REVERSED CONFIGURATIONS IN THE FRX-C LSM DEVICE SO PHYSICS OF FLUIDS B-PLASMA PHYSICS LA English DT Article ID ENERGY CONFINEMENT; TILT MODE; FLUX AB Recent data from the FRX-C/LSM device [Plasma Physics and Controlled Nuclear Fusion Research (IAEA, Vienna, 1989), Vol. II, p. 517] concerning the stability, translation, and compression heating of field-reversed configurations (FRC's) are reported. FRC tilt instabilities are clearly observed for the first time, a major step toward reconciling theory and experiments. Grossly stable FRC's appear to be restricted to very kinetic and elongated plasmas. Internal probing of translated FRC's reveals substantial toroidal field and nearly force-free magnetic field profiles in the central region of the compact toroid. High-power magnetic compression of translated FRC's is demonstrated. Substantial heating is observed, while the FRC confinement properties remain mostly unchanged. RP TUSZEWSKI, M (reprint author), UNIV CALIF LOS ALAMOS SCI LAB,LOS ALAMOS,NM 87545, USA. NR 22 TC 2 Z9 2 U1 0 U2 0 PU AMER INST PHYSICS PI WOODBURY PA CIRCULATION FULFILLMENT DIV, 500 SUNNYSIDE BLVD, WOODBURY, NY 11797-2999 SN 0899-8221 J9 PHYS FLUIDS B-PLASMA PD AUG PY 1991 VL 3 IS 8 BP 2205 EP 2208 DI 10.1063/1.859637 PN 2 PG 4 WC Physics, Fluids & Plasmas SC Physics GA FY451 UT WOS:A1991FY45100009 ER PT J AU REIMAN, A MONTICELLO, D AF REIMAN, A MONTICELLO, D TI TOKAMAK ERROR FIELDS AND LOCKED MODES SO PHYSICS OF FLUIDS B-PLASMA PHYSICS LA English DT Article ID TEARING MODE; EQUILIBRIA; LOCKING; ISLANDS AB The effects of externally applied, resonant magnetic field perturbations on tokamak plasmas are discussed. An analytical model assuming tokamak ordering and narrow islands clarifies the conditions under which error fields are amplified or diminished by self-consistent effects. A strong amplification of error fields near marginal tearing stability is found to broaden the range of parameters over which deleterious tearing effects are seen. Three-dimensional numerical solutions indicate that saturated tearing mode island widths can be sensitive to the presence of small nonaxisymmetric perturbations. It is argued that the theoretical conclusions are consistent with observations in error compensation experiments, and are also consistent with observations of enhanced growth for locked modes. RP REIMAN, A (reprint author), PRINCETON UNIV,PLASMA PHYS LAB,PRINCETON,NJ 08543, USA. NR 19 TC 20 Z9 20 U1 1 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 AUG PY 1991 VL 3 IS 8 BP 2230 EP 2235 DI 10.1063/1.859640 PN 2 PG 6 WC Physics, Fluids & Plasmas SC Physics GA FY451 UT WOS:A1991FY45100012 ER PT J AU HAMMER, JH EDDLEMAN, JL HARTMAN, CW MCLEAN, HS MOLVIK, AW AF HAMMER, JH EDDLEMAN, JL HARTMAN, CW MCLEAN, HS MOLVIK, AW TI EXPERIMENTAL DEMONSTRATION OF COMPACT TORUS COMPRESSION AND ACCELERATION SO PHYSICS OF FLUIDS B-PLASMA PHYSICS LA English DT Article ID SPHEROMAK AB Tests of compact torus (CT) compression on the RACE device [Phys. Rev. Lett. 61, 2843 (1988)] have successfully demonstrated stable compression by a factor of 2 in radius, field amplification by factors of 2-3 to 20 kG, and compressed densities exceeding 10(16) cm-3. The results are in good agreement with two-dimensional magnetohydrodynamic simulations of the CT dynamics. The CT is formed between a pair of coaxial conical conductors that serve as both a flux conserver for stable, symmetric formation and as electrodes for the compression and acceleration phases. The CT is compressed by J x B forces (poloidal current, toroidal field) when a 120 kV, 260 kJ capacitor bank is discharged across the electrodes. The CT reaches two-fold compression to a radius of 8 cm and a length of 20-30 cm near the time of peak current, 10-mu-sec (many Alfven times) after the accelerator fire time, and is subsequently accelerated in a 150 cm straight coaxial section to velocities in the range 1.5-6.5 x 10(7) cm/sec. A new set of acceleration/focusing electrodes 740 cm in length are projected to give an additional factor of 3 in radial compression with final velocities of 1-3 x 10(8) cm/sec (similar to previously achieved on RACE) and incident power densities of a few x 10(11) W/cm2. Compact torus accelerators scaled to multimegajoules have the potential to achieve unprecedented plasma velocities and power densities with many applications in high-energy-density physics. RP HAMMER, JH (reprint author), UNIV CALIF LAWRENCE LIVERMORE NATL LAB,LIVERMORE,CA 94526, USA. NR 17 TC 24 Z9 24 U1 2 U2 10 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 AUG PY 1991 VL 3 IS 8 BP 2236 EP 2240 DI 10.1063/1.859641 PN 2 PG 5 WC Physics, Fluids & Plasmas SC Physics GA FY451 UT WOS:A1991FY45100013 ER PT J AU HOKIN, S ALMAGRI, A ASSADI, S BECKSTEAD, J CHARTAS, G CROCKER, N CUDZINOVIC, M DENHARTOG, D DEXTER, R HOLLY, D PRAGER, S REMPEL, T SARFF, J SCIME, E SHEN, W SPRAGINS, C SPROTT, C STARR, G STONEKING, M WATTS, C NEBEL, R AF HOKIN, S ALMAGRI, A ASSADI, S BECKSTEAD, J CHARTAS, G CROCKER, N CUDZINOVIC, M DENHARTOG, D DEXTER, R HOLLY, D PRAGER, S REMPEL, T SARFF, J SCIME, E SHEN, W SPRAGINS, C SPROTT, C STARR, G STONEKING, M WATTS, C NEBEL, R TI GLOBAL CONFINEMENT AND DISCRETE DYNAMO ACTIVITY IN THE MST REVERSED-FIELD PINCH SO PHYSICS OF FLUIDS B-PLASMA PHYSICS LA English DT Article ID ETA-BETA-II; OSCILLATIONS; EVOLUTION; SAWTEETH; PLASMA; MODEL; TIME AB Results obtained on the Madison Symmetric Torus (MST) reversed-field pinch [Fusion Technol. 19, 131 (1991)] after installation of the design poloidal field winding are presented. Values of beta-theta-e0 = 2-mu-0n(e0)T(e0)/B-theta-2 (a) approximately 12% are achieved in low-current (I = 220 kA) operation; here, n(e0) and T(e0) are central electron density and temperature, and B-theta (a) is the poloidal magnetic field at the plasma edge. An observed decrease in beta-theta-e0 with increasing plasma current may be due to inadequate fueling, enhanced wall interaction, and the growth of a radial field error at the vertical cut in the shell at high current. Energy confinement time varies little with plasma current, lying in the range of 0.5-1.0 msec. Strong discrete dynamo activity is present, characterized by the coupling of m = 1, n = 5-7 modes leading to an m = 0, n = 0 crash (m and n are poloidal and toroidal mode numbers). The m = 0 crash generates toroidal flux and produces a small (2.5%) increase in plasma current. C1 UNIV CALIF LOS ALAMOS SCI LAB,LOS ALAMOS,NM 87545. RP HOKIN, S (reprint author), UNIV WISCONSIN,MADISON,WI 53706, USA. NR 25 TC 69 Z9 69 U1 1 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 AUG PY 1991 VL 3 IS 8 BP 2241 EP 2246 DI 10.1063/1.859642 PN 2 PG 6 WC Physics, Fluids & Plasmas SC Physics GA FY451 UT WOS:A1991FY45100014 ER PT J AU MURAKAMI, M ACETO, SC ANABITARTE, E ANDERSON, DT ANDERSON, FSB BATCHELOR, DB BRANAS, B BAYLOR, LR BELL, GL BELL, JD BIGELOW, TS CARRERAS, BA COLCHIN, RJ CROCKER, NA CRUME, EC DOMINGUEZ, N DORY, RA DUNLAP, JL DYER, GR ENGLAND, AC FOWLER, RH GANDY, RF GLOWIENKA, JC GOLDFINGER, RC GOULDING, RH HANSON, GR HARRIS, JH HIDALGO, C HILLIS, DL HIROE, S HIRSHMAN, SP HORTON, LD HOWE, HC HUTCHINSON, DP ISLER, RC JERNIGAN, TC KANEKO, H KWON, M LANGLEY, RA LEBOEUF, JN LEE, DK LO, DHC LYNCH, VE LYON, JF MA, CH MENON, MM MIODUSZEWSKI, PK MORITA, S MORRIS, RN NEILSON, GH OCHANDO, MA OKAMURA, S PAUL, S QUALLS, AL RASMUSSEN, DA RICHARDS, RK RITZ, CP ROME, JA SANCHEZ, J SCHWELBERGER, JG SHAING, KC SHEPARD, TD SIMPKINS, JE THOMAS, CE TOLLIVER, JS UCKAN, T VANDERSLUIS, KL WADE, MR WILGEN, JB WING, WR YAMADA, H ZIELINSKI, JJ AF MURAKAMI, M ACETO, SC ANABITARTE, E ANDERSON, DT ANDERSON, FSB BATCHELOR, DB BRANAS, B BAYLOR, LR BELL, GL BELL, JD BIGELOW, TS CARRERAS, BA COLCHIN, RJ CROCKER, NA CRUME, EC DOMINGUEZ, N DORY, RA DUNLAP, JL DYER, GR ENGLAND, AC FOWLER, RH GANDY, RF GLOWIENKA, JC GOLDFINGER, RC GOULDING, RH HANSON, GR HARRIS, JH HIDALGO, C HILLIS, DL HIROE, S HIRSHMAN, SP HORTON, LD HOWE, HC HUTCHINSON, DP ISLER, RC JERNIGAN, TC KANEKO, H KWON, M LANGLEY, RA LEBOEUF, JN LEE, DK LO, DHC LYNCH, VE LYON, JF MA, CH MENON, MM MIODUSZEWSKI, PK MORITA, S MORRIS, RN NEILSON, GH OCHANDO, MA OKAMURA, S PAUL, S QUALLS, AL RASMUSSEN, DA RICHARDS, RK RITZ, CP ROME, JA SANCHEZ, J SCHWELBERGER, JG SHAING, KC SHEPARD, TD SIMPKINS, JE THOMAS, CE TOLLIVER, JS UCKAN, T VANDERSLUIS, KL WADE, MR WILGEN, JB WING, WR YAMADA, H ZIELINSKI, JJ TI RECENT RESULTS FROM THE ATF TORSATRON SO PHYSICS OF FLUIDS B-PLASMA PHYSICS LA English DT Article ID PLASMA-CONFINEMENT; 2ND STABILITY; STELLARATORS AB Recent experiments in the Advanced Toroidal Facility (ATF) torsatron [Plasma Physics and Controlled Nuclear Fusion Research 1990 (IAEA, Vienna, in press)] have emphasized the role of magnetic configuration control in transport studies. Long-pulse plasma operation up to 20 sec has been achieved with electron cyclotron heating (ECH). With neutral beam injection (NBI) power of greater-than-or-equal-to 1 MW, global energy confinement times of 30 msec have been obtained with line-average densities up to 1.3 x 10(20) m-3. The energy confinement and the operational space in ATF are roughly the same as those in tokamaks of similar size and field. The empirical scaling observed is similar to gyro-reduced Bohm scaling with favorable dependences on density and field offsetting an unfavorable power dependence. The toroidal current measured during ECH is identified as the bootstrap current. The observed currents agree well with predictions of neoclassical theory in magnitude and in parametric dependence. Variations of the magnetic configuration in discharges heated by ECH alone and by NBI change plasma transport and plasma profiles. Magnetic fluctuations respond to the concomitant pressure profile variations. Comparative studies of edge fluctuations in the Texas Experimental Tokamak (TEXT) [Plasma Physics and Controlled Nuclear Fusion Research 1990 (IAEA, Vienna, in press)] and the ATF stellarator showed remarkable similarity in the levels of fluctuations and the existence of a velocity shear layer. C1 RENSSELAER POLYTECH INST,TROY,NY 12181. CTR INVEST ENERGET MEDIOAMBIENTALES & TECNOL,MADRID,SPAIN. UNIV WISCONSIN,MADISON,WI 53706. MARTIN MARIETTA ENERGY SYST INC,DIV ENGN,OAK RIDGE,TN 37831. MARTIN MARIETTA ENERGY SYST INC,DIV COMP & TELECOMMUN,OAK RIDGE,TN 37831. AUBURN UNIV,AUBURN,AL 36849. GEORGIA INST TECHNOL,ATLANTA,GA 30332. NATL INST FUS SCI,NAGOYA,JAPAN. MIT,CAMBRIDGE,MA 02139. PRINCETON UNIV,PLASMA PHYS LAB,NEW JERSEY,NJ 08543. UNIV TENNESSEE,KNOXVILLE,TN 37916. UNIV TEXAS,AUSTIN,TX 78712. RP MURAKAMI, M (reprint author), OAK RIDGE NATL LAB,OAK RIDGE,TN 37831, USA. RI Lynch, Vickie/J-4647-2012; Hidalgo, Carlos/H-6109-2015; OI Lynch, Vickie/0000-0002-5836-7636; Morris, Robert/0000-0001-7192-7733; Isler, Ralph/0000-0002-5368-7200 NR 29 TC 19 Z9 19 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 AUG PY 1991 VL 3 IS 8 BP 2261 EP 2269 DI 10.1063/1.859645 PN 2 PG 9 WC Physics, Fluids & Plasmas SC Physics GA FY451 UT WOS:A1991FY45100017 ER PT J AU WILSON, JR HOSEA, JC BELL, MG BITTER, M BOIVIN, R FREDRICKSON, ED GREENE, GJ HAMMETT, GW HILL, KW HOFFMAN, DJ HSUAN, H HUGHES, M JANOS, AC JASSBY, DL JOBES, FC JOHNSON, DW PHILLIPS, CK MANSFIELD, DK MCGUIRE, KM MEDLEY, SS MUELLER, D NAGAYAMA, Y ONO, M OWENS, DK PARK, HK PHILLIPS, M RAMSEY, AT SCHMIDT, GL SCOTT, SD STEVENS, JE STRATTON, BC SYNAKOWSKI, E TAYLOR, G ULRICKSON, M WONG, KL ZARNSTORFF, MC ZWEBEN, SJ AF WILSON, JR HOSEA, JC BELL, MG BITTER, M BOIVIN, R FREDRICKSON, ED GREENE, GJ HAMMETT, GW HILL, KW HOFFMAN, DJ HSUAN, H HUGHES, M JANOS, AC JASSBY, DL JOBES, FC JOHNSON, DW PHILLIPS, CK MANSFIELD, DK MCGUIRE, KM MEDLEY, SS MUELLER, D NAGAYAMA, Y ONO, M OWENS, DK PARK, HK PHILLIPS, M RAMSEY, AT SCHMIDT, GL SCOTT, SD STEVENS, JE STRATTON, BC SYNAKOWSKI, E TAYLOR, G ULRICKSON, M WONG, KL ZARNSTORFF, MC ZWEBEN, SJ TI EXPERIMENTS UTILIZING ION-CYCLOTRON RANGE OF FREQUENCIES HEATING ON THE TFTR TOKAMAK SO PHYSICS OF FLUIDS B-PLASMA PHYSICS LA English DT Article AB A variety of experiments have been performed on the TFTR tokamak [Wilson et al., Plasma Physics and Controlled Nuclear Fusion Research 1988 (IAEA, Vienna, 1989), Vol. 1, p. 691] utilizing ion cyclotron range of frequencies (ICRF) heating. Of special interest has been the insight into plasma performance gained by utilizing a different heating scheme other than the usual neutral beam injection (NBI). Utilizing ICRF heating allows control over the power deposition profile independent of the plasma fueling profile. In addition, by varying the minority concentration the power split between ion and electron heating can be varied. Confinement has been examined in high recycling gas fueled discharges, low recycling supershot plasmas, and peaked density pellet fueled discharges. Global confinement is found not to be affected by the method or localization of plasma heating, but the calculated local diffusivities vary with the power deposition profile to yield similar global values. In addition, sawtooth stabilization observed with ICRF heating has been investigated and found to occur in qualitative agreement with theory. ICRF sawtooth stabilized discharges exhibit peaked temperature and density profiles and have a safety factor q that appears to fall well below unity on axis. RP WILSON, JR (reprint author), PRINCETON UNIV,PLASMA PHYS LAB,PRINCETON,NJ 08543, USA. RI Hammett, Gregory/D-1365-2011 OI Hammett, Gregory/0000-0003-1495-6647 NR 11 TC 7 Z9 7 U1 2 U2 4 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 AUG PY 1991 VL 3 IS 8 BP 2270 EP 2276 DI 10.1063/1.859646 PN 2 PG 7 WC Physics, Fluids & Plasmas SC Physics GA FY451 UT WOS:A1991FY45100018 ER PT J AU SABBAGH, SA GROSS, RA MAUEL, ME NAVRATIL, GA BELL, MG BELL, R BITTER, M BRETZ, NL BUDNY, RV BUSH, CE CHANCE, MS EFTHIMION, PC FREDRICKSON, ED HATCHER, R HAWRYLUK, RJ HIRSHMAN, SP JANOS, AC JARDIN, SC JASSBY, DL MANICKAM, J MCCUNE, DC MCGUIRE, KM MEDLEY, SS MUELLER, D NAGAYAMA, Y OWENS, DK OKABAYASHI, M PARK, HK RAMSEY, AT STRATTON, BC SYNAKOWSKI, EJ TAYLOR, G WIELAND, RM ZARNSTORFF, MC KESNER, J MARMAR, ES TERRY, JL AF SABBAGH, SA GROSS, RA MAUEL, ME NAVRATIL, GA BELL, MG BELL, R BITTER, M BRETZ, NL BUDNY, RV BUSH, CE CHANCE, MS EFTHIMION, PC FREDRICKSON, ED HATCHER, R HAWRYLUK, RJ HIRSHMAN, SP JANOS, AC JARDIN, SC JASSBY, DL MANICKAM, J MCCUNE, DC MCGUIRE, KM MEDLEY, SS MUELLER, D NAGAYAMA, Y OWENS, DK OKABAYASHI, M PARK, HK RAMSEY, AT STRATTON, BC SYNAKOWSKI, EJ TAYLOR, G WIELAND, RM ZARNSTORFF, MC KESNER, J MARMAR, ES TERRY, JL TI HIGH POLOIDAL BETA EQUILIBRIA IN THE TOKAMAK FUSION TEST REACTOR LIMITED BY A NATURAL INBOARD POLOIDAL FIELD NULL SO PHYSICS OF FLUIDS B-PLASMA PHYSICS LA English DT Article ID BOOTSTRAP CURRENT; CONFINEMENT; PLASMAS; PROFILE; TFTR AB Recent operation of the Tokamak Fusion Test Reactor (TFTR) [Plasma Phys. Controlled Nucl. Fusion Research 1, 51 (1986)] has produced plasma equilibria with values of LAMBDA = beta-p eq + l(i)/2 as large as 7, epsilon-beta-p dia = 2-mu-0 epsilon

/<>2 as large as 1.6, and Troyon normalized diamagnetic beta [Plasma Phys. Controlled Fusion 26, 209 (1984); Phys. Lett. 110A, 29 (1985)], beta-N dia = 10(8) aB0/I(p) as large as 4.7. When epsilon-beta-p dia greater-than-or-similar-to 1.25, a separatrix entered the vacuum chamber, producing a naturally diverted discharge that was sustained for many energy confinement times, tau-E. The largest values of epsilon-beta-p and plasma stored energy were obtained when the plasma current was ramped down prior to neutral beam injection. The measured peak ion and electron temperatures were as large as 24 and 8.5 keV, respectively. Plasma stored energy in excess of 2.5 MJ and tau-E greater than 130 msec were obtained. Confinement times of greater than 3 times that expected from L-mode predictions have been achieved. The fusion power gain Q(DD) reached a value of 1.3 x 10(-3) in a discharge with I(p) = 1 MA and epsilon-beta-p dia = 0.85. A large, sustained negative loop voltage during the steady-state portion of the discharge indicates that a substantial noniductive component of I(p) exists in these plasmas. Transport code analysis indicates that the bootstrap current constitutes up to 65% of I(p). Magnetohydrodynamic (MHD) ballooning stability analysis shows that, while these plasmas are near, or at the beta-p limit, the pressure gradient in the plasma core is in the first region of stability to high-n modes. C1 MIT,CTR PLASMA FUS,CAMBRIDGE,MA 02139. PRINCETON UNIV,PLASMA PHYS LAB,PRINCETON,NJ 08543. RP SABBAGH, SA (reprint author), COLUMBIA UNIV,DEPT APPL PHYS,NEW YORK,NY 10027, USA. RI Jardin, Stephen/E-9392-2010; Sabbagh, Steven/C-7142-2011; OI Mauel, Michael/0000-0003-2490-7478 NR 31 TC 58 Z9 58 U1 1 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 AUG PY 1991 VL 3 IS 8 BP 2277 EP 2284 DI 10.1063/1.859647 PN 2 PG 8 WC Physics, Fluids & Plasmas SC Physics GA FY451 UT WOS:A1991FY45100019 ER PT J AU LEBOEUF, JN LEE, DK CARRERAS, BA DOMINGUEZ, N HARRIS, JH HEDRICK, CL HIDALGO, C HOLMES, JA RUITER, J DIAMOND, PH WARE, AS RITZ, CP WOOTTON, AJ ROWAN, WL BRAVENEC, RV AF LEBOEUF, JN LEE, DK CARRERAS, BA DOMINGUEZ, N HARRIS, JH HEDRICK, CL HIDALGO, C HOLMES, JA RUITER, J DIAMOND, PH WARE, AS RITZ, CP WOOTTON, AJ ROWAN, WL BRAVENEC, RV TI TEXT TOKAMAK EDGE TURBULENCE MODELING SO PHYSICS OF FLUIDS B-PLASMA PHYSICS LA English DT Article ID FACILITY AB Experimental results on the Texas Experimental Tokamak (TEXT) [Nucl. Technol./Fusion 1, 479 (1982)] and the Advanced Toroidal Facility (ATF) torsatron [Fusion Technol. 10, 179 (1986)] indicate that electrostatic fluctuations can explain the edge transport of particles and perhaps energy. Certain mechanisms for drive (radiation and ionization, as well as density and temperature gradients) and stabilization (velocity shear) are suggested by these results. The experimental fluctuation levels and turbulence characteristics can be reproduced by considering the nonlinear evolution of fluid-type equations, incorporating thermal and ionization drives. C1 UNIV CALIF SAN DIEGO,LA JOLLA,CA 92093. UNIV TEXAS,FUS RES CTR,AUSTIN,TX 78712. MARTIN MARIETTA ENERGY SYST INC,DIV COMP & TELECOMMUN,OAK RIDGE,TN 37831. ASOCIAC EURATOM,CIEMAT FUS,MADRID,SPAIN. ALBION COLL,ALBION,MI 49224. RP LEBOEUF, JN (reprint author), OAK RIDGE NATL LAB,OAK RIDGE,TN 37831, USA. RI Hidalgo, Carlos/H-6109-2015 NR 12 TC 49 Z9 49 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 AUG PY 1991 VL 3 IS 8 BP 2291 EP 2299 DI 10.1063/1.859596 PN 2 PG 9 WC Physics, Fluids & Plasmas SC Physics GA FY451 UT WOS:A1991FY45100021 ER PT J AU JASSBY, DL BARNES, CW BELL, MG BITTER, M BOIVIN, R BRETZ, NL BUDNY, RV BUSH, CE DYLLA, HF EFTHIMION, PC FREDRICKSON, ED HAWRYLUK, RJ HILL, KW HOSEA, J HSUAN, H JANOS, AC JOBES, FC JOHNSON, DW JOHNSON, LC KAMPERSCHROER, J KIERASPHILLIPS, C KILPATRICK, SJ LAMARCHE, PH LEBLANC, B MANSFIELD, DK MARMAR, ES MCCUNE, DC MCGUIRE, KM MEADE, DM MEDLEY, SS MIKKELSEN, DR MUELLER, D OWENS, DK PARK, HK PAUL, SF PITCHER, S RAMSEY, AT REDI, MH SABBAGH, SA SCOTT, SD SNIPES, J STEVENS, J STRACHAN, JD STRATTON, BC SYNAKOWSKI, EJ TAYLOR, G TERRY, JL TIMBERLAKE, JR TOWNER, HH ULRICKSON, M VONGOELER, S WIELAND, RM WILLIAMS, M WILSON, JR WONG, KL YOUNG, KM ZARNSTORFF, MC ZWEBEN, SJ AF JASSBY, DL BARNES, CW BELL, MG BITTER, M BOIVIN, R BRETZ, NL BUDNY, RV BUSH, CE DYLLA, HF EFTHIMION, PC FREDRICKSON, ED HAWRYLUK, RJ HILL, KW HOSEA, J HSUAN, H JANOS, AC JOBES, FC JOHNSON, DW JOHNSON, LC KAMPERSCHROER, J KIERASPHILLIPS, C KILPATRICK, SJ LAMARCHE, PH LEBLANC, B MANSFIELD, DK MARMAR, ES MCCUNE, DC MCGUIRE, KM MEADE, DM MEDLEY, SS MIKKELSEN, DR MUELLER, D OWENS, DK PARK, HK PAUL, SF PITCHER, S RAMSEY, AT REDI, MH SABBAGH, SA SCOTT, SD SNIPES, J STEVENS, J STRACHAN, JD STRATTON, BC SYNAKOWSKI, EJ TAYLOR, G TERRY, JL TIMBERLAKE, JR TOWNER, HH ULRICKSON, M VONGOELER, S WIELAND, RM WILLIAMS, M WILSON, JR WONG, KL YOUNG, KM ZARNSTORFF, MC ZWEBEN, SJ TI HIGH-Q PLASMAS IN THE TFTR TOKAMAK SO PHYSICS OF FLUIDS B-PLASMA PHYSICS LA English DT Article ID CALIBRATION AB In the Tokamak Fusion Test Reactor (TFTR) [Plasma Phys. Controlled Fusion 26, 11 (1984)], the highest neutron source strength S(n) and D-D fusion power gain Q(DD) are realized in the neutral-beam-fueled and heated "supershot" regime that occurs after extensive wall conditioning to minimize recycling. For the best supershots, S(n) increases approximately as P(b)1.8. The highest-Q shots are characterized by high T(e) (up to 12 keV), T(i) (up to 34 keV), and stored energy (up to 4.7 MJ), highly peaked density profiles, broad T(e) profiles, and lower Z(eff). Replacement of critical areas of the graphite limiter tiles with carbon-fiber composite tiles and improved alignment with the plasma have mitigated the "carbon bloom." Wall conditioning by lithium pellet injection prior to the beam pulse reduces carbon influx and particle recycling. Empirically, Q(DD) increases with decreasing pre-injection carbon radiation, and increases strongly with density peakedness [n(e) (0)/] during the beam pulse. To date, the best fusion results are S(n) = 5 X 10(16) n/sec, Q(DD) = 1.85 X 10(-3), and neutron yield = 4.0 X 10(16) n/pulse, obtained at I(p) = 1.6-1.9 MA and beam energy E(b) = 95-103 keV, with nearly balanced co- and counter-injected beam power. Computer simulations of supershot plasmas show that typically 50%-60% of S(n) arises from beam-target reactions, with the remainder divided between beam-beam and thermonuclear reactions, the thermonuclear fraction increasing with P(b). The simulations predict that Q(DT) = 0.3-0.4 would be obtained for the best present plasma conditions, if half the deuterium neutral beams were to be replaced by tritium beams. Somewhat higher values are calculated if D beams are injected into a predominantly tritium target plasma. The projected central beta of fusion alphas is 0.4%-0.6%, a level sufficient for the study of alpha-induced collective effects. RP JASSBY, DL (reprint author), PRINCETON UNIV,PLASMA PHYS LAB,PRINCETON,NJ 08543, USA. RI Sabbagh, Steven/C-7142-2011 NR 21 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 0899-8221 J9 PHYS FLUIDS B-PLASMA PD AUG PY 1991 VL 3 IS 8 BP 2308 EP 2314 DI 10.1063/1.859988 PN 2 PG 7 WC Physics, Fluids & Plasmas SC Physics GA FY451 UT WOS:A1991FY45100023 ER PT J AU EFTHIMION, PC BARNES, CW BELL, MG BIGLARI, H BRETZ, N DIAMOND, PH HAMMETT, G HEIDBRINK, W HULSE, R JOHNSON, D KUSAMA, Y MANSFIELD, D MEDLEY, SS NAZIKIAN, R PARK, H RAMSEY, A REWOLDT, G SCOTT, SD STRATTON, BC SYNAKOWSKI, E TANG, WM TAYLOR, G ZARNSTORFF, MC ZWEBEN, SJ AF EFTHIMION, PC BARNES, CW BELL, MG BIGLARI, H BRETZ, N DIAMOND, PH HAMMETT, G HEIDBRINK, W HULSE, R JOHNSON, D KUSAMA, Y MANSFIELD, D MEDLEY, SS NAZIKIAN, R PARK, H RAMSEY, A REWOLDT, G SCOTT, SD STRATTON, BC SYNAKOWSKI, E TANG, WM TAYLOR, G ZARNSTORFF, MC ZWEBEN, SJ TI COMPARISON OF STEADY-STATE AND PERTURBATIVE TRANSPORT-COEFFICIENTS IN TFTR SO PHYSICS OF FLUIDS B-PLASMA PHYSICS LA English DT Article ID GRADIENT-DRIVEN TURBULENCE; ENERGY CONFINEMENT; HEATED TOKAMAKS; ION-TRANSPORT; TEMPERATURE; REACTOR; PLASMAS; MODE AB Steady-state and perturbative transport analysis are complementary techniques for the study of transport in tokamaks. These techniques are applied to the investigation of auxiliary-heated L-mode and supershot plasmas in the tokamak fusion test reactor (TFTR) [R. J. Hawryluk et al., Plasma Physics and Controlled Nuclear Fusion Research, Proceedings of the 11th International Conference, Kyoto, 1986 (IAEA, Vienna, 1987), Vol. 1, p. 51.]. In the L mode, both steady-state and perturbative transport measurements reveal a strong temperature dependence that is consistent with electrostatic microinstability theory and the degradation of confinement with neutral beam power. Steady-state analysis of the ion heat and momentum balance in supershots indicates a reduction and a significant weakening of the power-law dependence on the transport in the center of the discharge. C1 UNIV CALIF LOS ALAMOS SCI LAB,LOS ALAMOS,NM 87545. UNIV CALIF SAN DIEGO,LA JOLLA,CA 92093. UNIV CALIF IRVINE,IRVINE,CA 92717. JAPAN ATOM ENERGY RES INST,NAKA FUS RES ESTAB,NAKA,IBARAKI,JAPAN. RP EFTHIMION, PC (reprint author), PRINCETON UNIV,PLASMA PHYS LAB,POB 451,PRINCETON,NJ 08543, USA. RI Hammett, Gregory/D-1365-2011 OI Hammett, Gregory/0000-0003-1495-6647 NR 41 TC 31 Z9 31 U1 0 U2 4 PU AMER INST PHYSICS PI WOODBURY PA CIRCULATION FULFILLMENT DIV, 500 SUNNYSIDE BLVD, WOODBURY, NY 11797-2999 SN 0899-8221 J9 PHYS FLUIDS B-PLASMA PD AUG PY 1991 VL 3 IS 8 BP 2315 EP 2323 DI 10.1063/1.859598 PN 2 PG 9 WC Physics, Fluids & Plasmas SC Physics GA FY451 UT WOS:A1991FY45100024 ER PT J AU YOUNG, PE AF YOUNG, PE TI EXPERIMENTAL-STUDY OF FILAMENTATION IN LASER PLASMA INTERACTIONS SO PHYSICS OF FLUIDS B-PLASMA PHYSICS LA English DT Article ID LIGHT AB The filamentation instability can lead to regions of increased laser intensity when a spatially nonuniform laser beam interacts with a plasma. An experimental technique will be described that identifies the density perturbation produced by filaments. The growth of filaments has been investigated and, when the laser intensity is large enough, the transverse density profile of the filament can be measured. Evidence of filament growth influenced by plasma flow and density gradients is presented. RP YOUNG, PE (reprint author), UNIV CALIF LAWRENCE LIVERMORE NATL LAB,POB 808,LIVERMORE,CA 94550, USA. NR 22 TC 34 Z9 35 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 AUG PY 1991 VL 3 IS 8 BP 2331 EP 2336 DI 10.1063/1.859600 PN 2 PG 6 WC Physics, Fluids & Plasmas SC Physics GA FY451 UT WOS:A1991FY45100026 ER PT J AU WALLACE, JM FORSLUND, DW KINDEL, JM OLSON, GL COMLY, JC AF WALLACE, JM FORSLUND, DW KINDEL, JM OLSON, GL COMLY, JC TI SHORT-PULSE, LASER PLASMA INTERACTION INCLUDING COLLISIONS AND IONIZATION SO PHYSICS OF FLUIDS B-PLASMA PHYSICS LA English DT Article ID IRRADIATED PLASMAS; ABSORPTION; SIMULATION; SCATTERING AB A computational approach for simulations in the emerging field of short-pulse (tau < 1 psec), high-intensity (I = 10(17) - 10(19) W/cm2) laser-plasma interactions is introduced. The approach is a particle-in-cell method (PIC) which, as unique features, incorporates electron-ion collisions at relativistic energies and the time variation of the ionization state of the plasma. This has been incorporated into the WAVE two-dimensional plasma simulation code [Phys. Fluids 18, 1017 (1975)] for the purpose of simulating experiments at the Los Alamos Bright Source facilities [Phys. Rev. A 39, 454 (1989)]. However, the computational methods should be useful for work in laser fusion and other areas where rapid ionization occurs. RP WALLACE, JM (reprint author), UNIV CALIF LOS ALAMOS SCI LAB,LOS ALAMOS,NM 87545, USA. OI Forslund, David/0000-0002-6534-3392 NR 25 TC 14 Z9 14 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 AUG PY 1991 VL 3 IS 8 BP 2337 EP 2340 DI 10.1063/1.859601 PN 2 PG 4 WC Physics, Fluids & Plasmas SC Physics GA FY451 UT WOS:A1991FY45100027 ER PT J AU BALDIS, HA VILLENEUVE, DM LABAUNE, C PESME, D ROZMUS, W KRUER, WL YOUNG, PE AF BALDIS, HA VILLENEUVE, DM LABAUNE, C PESME, D ROZMUS, W KRUER, WL YOUNG, PE TI COEXISTENCE OF STIMULATED RAMAN AND BRILLOUIN-SCATTERING IN LASER-PRODUCED PLASMAS SO PHYSICS OF FLUIDS B-PLASMA PHYSICS LA English DT Article ID PARAMETRIC-INSTABILITIES; FOIL TARGETS; WAVES; COMPETITION; SATURATION; WAVELENGTH; LIGHT AB Many different plasma instabilities and plasma modes can coexist in laser plasmas. These instabilities are usually treated as if they occur in isolation, however, more attention has recently been paid to how they interact with each other. This paper reviews three examples of experiments that have demonstrated an interaction between stimulated Raman scattering (SRS) and stimulated Brillouin scattering (SBS). In each case, the presence of SBS is seen to modify the behavior of the SRS process. In one case, SRS was totally suppressed by seeding SBS. The same mechanism might also be responsible for the gap in the Raman spectrum. Some theoretical and numerical studies of the interaction between SRS and SBS are also discussed, showing how increasingly detailed models can give improved agreement with experimental observations. C1 NATL RES COUNCIL CANADA,OTTAWA K1A 0R6,ONTARIO,CANADA. ECOLE POLYTECH,F-91128 PALAISEAU,FRANCE. RP BALDIS, HA (reprint author), UNIV CALIF LAWRENCE LIVERMORE NATL LAB,POB 808,LIVERMORE,CA 94550, USA. RI Villeneuve, David/I-4140-2012 OI Villeneuve, David/0000-0002-2810-3648 NR 44 TC 33 Z9 33 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 AUG PY 1991 VL 3 IS 8 BP 2341 EP 2348 DI 10.1063/1.859602 PN 2 PG 8 WC Physics, Fluids & Plasmas SC Physics GA FY451 UT WOS:A1991FY45100028 ER PT J AU HAAN, SW AF HAAN, SW TI WEAKLY NONLINEAR HYDRODYNAMIC INSTABILITIES IN INERTIAL FUSION SO PHYSICS OF FLUIDS B-PLASMA PHYSICS LA English DT Article ID RAYLEIGH-TAYLOR INSTABILITY; SIMULATIONS; TARGETS; GROWTH AB For many cases of interest to inertial fusion, growth of Rayleigh-Taylor and other hydrodynamic instabilities is such that the perturbations remain linear or weakly nonlinear. The transition to nonlinearity is studied via a second-order solution for multimode classical Rayleigh-Taylor growth. The second-order solution shows how classical Rayleigh-Taylor systems forget initial amplitude information in the weakly nonlinear phase. Stabilized growth relevant to inertial fusion is qualitatively different, and initial amplitudes are not dominated by nonlinear effects. In all systems with a full spectrum of modes, nonlinear effects begin when mode amplitudes reach about 1/Lk2, for modes of wave number k and system size L. RP HAAN, SW (reprint author), UNIV CALIF LAWRENCE LIVERMORE NATL LAB,LIVERMORE,CA 94550, USA. NR 46 TC 138 Z9 139 U1 3 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 AUG PY 1991 VL 3 IS 8 BP 2349 EP 2355 DI 10.1063/1.859603 PN 2 PG 7 WC Physics, Fluids & Plasmas SC Physics GA FY451 UT WOS:A1991FY45100029 ER PT J AU KRUER, WL AF KRUER, WL TI INTENSE LASER PLASMA INTERACTIONS - FROM JANUS TO NOVA SO PHYSICS OF FLUIDS B-PLASMA PHYSICS LA English DT Article ID SCALE RESONANT MODIFICATION; INDUCED SPATIAL INCOHERENCE; HOT-ELECTRON PRODUCTION; RAMAN-SCATTERING; PARAMETRIC-INSTABILITIES; MU-M; ELECTROMAGNETIC-WAVES; BRILLOUIN-SCATTERING; POLAR IONOSPHERE; STIMULATED RAMAN AB An overview of intense laser plasma interactions is given. The relevant physical processes range from collisional absorption to the excitation of instabilities, such as stimulated Raman and Brillouin scattering. These processes and important consequences that include suprathermal particle generation and enhanced absorption or scattering have been examined in theory, computer simulation, and experiments. The interaction physics has been studied in experiments using electromagnetic waves with wavelengths ranging from a fraction of a micron to tens of meters. Virtually every major interaction process has now been identified in laser plasma experiments, which have grown remarkably in sophistication over the years. Various control techniques have been demonstrated, and some intensity-wavelength regimes for efficient laser plasma coupling have been successfully identified. Indeed, current implosion experiments show excellent coupling of laser energy into thermal plasma. Future challenges include a better understanding of nonlinear levels, the competition of instabilities in large plasmas, and the beneficial effects of laser beam smoothing. RP KRUER, WL (reprint author), UNIV CALIF LAWRENCE LIVERMORE NATL LAB,LIVERMORE,CA 94550, USA. NR 63 TC 28 Z9 29 U1 1 U2 7 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 AUG PY 1991 VL 3 IS 8 BP 2356 EP 2366 DI 10.1063/1.859604 PN 2 PG 11 WC Physics, Fluids & Plasmas SC Physics GA FY451 UT WOS:A1991FY45100030 ER PT J AU YAMADA, M PERKINS, FW MACAULAY, AK ONO, Y KATSURAI, M AF YAMADA, M PERKINS, FW MACAULAY, AK ONO, Y KATSURAI, M TI INITIAL RESULTS FROM INVESTIGATION OF 3-DIMENSIONAL MAGNETIC RECONNECTION IN A LABORATORY PLASMA SO PHYSICS OF FLUIDS B-PLASMA PHYSICS LA English DT Article ID FIELDS AB A comprehensive laboratory experiment has been proposed to investigate the fundamental 3-D physics of magnetic reconnection regions and their associated hydromagnetic flows. Two toroidal plasma rings, with equal or opposite magnetic helicity, are formed and then brought together, contacting along a toroidally symmetric line. This research addresses three important questions: (1) How does magnetic helicity affect reconnection? (2) Will three-dimensional processes arise spontaneously and modify the usual Sweet-Parker or Petschek picture of two-dimensional reconnection where the global configuration is that of an axisymmetric X-point line? (3) How does the reconnection rate respond to global forcing? In a preliminary experiment carried out at the University of Tokyo [Phys. Rev. Lett. 65, 721 (1990)], the direction of the toroidal field plays an important role in the merging process. It is found that plasmas of opposite helicity merge appreciably faster than those of similar helicity. It is also found that the reconnection rate is proportional to the external force suggesting that magnetic reconnection, in the present experiment, is a forced phenomenon. A comparison of the present experimental data with 2-D computer simulation results is made. C1 UNIV TOKYO,DEPT ELECT ENGN,BUNKYO KU,TOKYO 113,JAPAN. RP YAMADA, M (reprint author), UNIV PRINCETON,PLASMA PHYS LAB,PRINCETON,NJ 08543, USA. RI Yamada, Masaaki/D-7824-2015 OI Yamada, Masaaki/0000-0003-4996-1649 NR 22 TC 22 Z9 22 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 AUG PY 1991 VL 3 IS 8 BP 2379 EP 2386 DI 10.1063/1.859607 PN 2 PG 8 WC Physics, Fluids & Plasmas SC Physics GA FY451 UT WOS:A1991FY45100033 ER PT J AU SANFORD, TWL AF SANFORD, TWL TI DYNAMICS OF ELECTRON FLOWS AND RADIATION-FIELDS PRODUCED BY ELECTRON-BEAM DIODES ON THE HERMES III ACCELERATOR SO PHYSICS OF FLUIDS B-PLASMA PHYSICS LA English DT Article ID COAXIAL BREMSSTRAHLUNG DIODES; PLANAR-ANODE DIODE; UNIFORMITY AB Several novel diodes to control the 19 MeV, 700 kA electron beam and subsequent bremsstrahlung from the HERMES III accelerator [Ramirez et al., Digest of Technical Papers of the 6th IEEE Pulse Power Conference (IEEE, New York, 1987), p. 294] have been designed and tested for the study of nuclear radiation effects. The electron beam has been propagated over 10 m in low-pressure gas cells. A comprehensive set of diagnostics has been developed to characterize the performance of these diodes, beams, and radiation fields. The observed performance has been compared with models that combine the simulation of electron flow, using the MAGIC particle-in-cell (PIC) code [Pointon, J. Comput. Phys. (in press)] with simulation of electron-photon transport in bremsstrahlung targets, using the CYLTRAN Monte Carlo code [Halbleib and Mehlhorn, Nucl. Sci. Eng. 92, 338 (1986)]. Beam transport results have been compared with IPROP PIC code [Godfrey and Welch, Twelfth Conference on Numerical Simulation of Plasmas (Lawrence Livermore National Laboratory, San Francisco, 1987), Paper No. CM1] simulations. The models are able to accurately predict the detailed spatial and temporal dependence of the electron flow and the resulting radiation field. This work provides fundamental insight into the behavior of high-voltage, high-current diodes. The present status of the research is reviewed. RP SANFORD, TWL (reprint author), SANDIA NATL LABS,ALBUQUERQUE,NM 87185, USA. NR 43 TC 8 Z9 8 U1 1 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 AUG PY 1991 VL 3 IS 8 BP 2387 EP 2395 DI 10.1063/1.859608 PN 2 PG 9 WC Physics, Fluids & Plasmas SC Physics GA FY451 UT WOS:A1991FY45100034 ER PT J AU SKINNER, CH AF SKINNER, CH TI REVIEW OF SOFT-X-RAY LASERS AND THEIR APPLICATIONS SO PHYSICS OF FLUIDS B-PLASMA PHYSICS LA English DT Article ID RECOMBINING-PLASMA; CAPILLARY DISCHARGE; HYDROGENIC SODIUM; AMPLIFICATION; GAIN; EMISSION; MICROSCOPY; TRANSITION; WAVELENGTH; HOLOGRAPHY AB The emerging technology of soft x-ray lasers is in a transition phase between the first laboratory demonstrations of gain and the acceptance of soft x-ray lasers as practical tools for novel applications. Current research is focused on several fronts. The operational wavelength range has been extended to the "water window," important for applications in the life sciences. Gain has also been generated with substantially simpler technology (such as a 6 J laser) and this augurs well for the commercial availability in the near future of soft x-ray lasers for a variety of applications. Advanced soft x-ray laser concepts are being developed from investigations into ultrahigh intensity laser/matter interactions. The first applications of soft x-ray lasers to x-ray microscopy and holography have begun. In this paper a brief historical perspective of x-ray laser development will be followed by a review of recent advances in recombination, collisional, and photopumped systems and applications. A summary of current gain-length performance achieved in laboratories worldwide is presented. Near-term prospects for applications to novel fields are discussed. RP SKINNER, CH (reprint author), PRINCETON UNIV,PLASMA PHYS LAB,PRINCETON,NJ 08543, USA. NR 105 TC 74 Z9 74 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 AUG PY 1991 VL 3 IS 8 BP 2420 EP 2429 DI 10.1063/1.859613 PN 2 PG 10 WC Physics, Fluids & Plasmas SC Physics GA FY451 UT WOS:A1991FY45100039 ER PT J AU SUCKEWER, S AF SUCKEWER, S TI QUENCHING OF EINSTEIN A-COEFFICIENTS IN PLASMAS AND LASERS SO PHYSICS OF FLUIDS B-PLASMA PHYSICS LA English DT Article ID SPONTANEOUS-EMISSION COEFFICIENTS AB The coefficient of spontaneous emission (Einstein A coefficient) is considered to be one of the basic constants of a given transition in an atom or ion. The formula for the Einstein A coefficient was derived in the pioneering works of Weisskopf and Wigner (WW) [Z. Phys. 63, 54 (1930)] based on Dirac's theory of light. More recently, however, it was noted in several paperss that the rate of spontaneous radiative decay can deviate significantly from the WW expression in certain conditions, for example, in a laser cavity. A different type of change in A coefficients was inferred from measurements of changes in the intensity branching ratio of spectral lines in a plasma. A change of branching ratio of up to a factor of 10 was observed in CIV for 3p-3s (580.1-581.2 nm) and 3p-2s (31.2 nm) transitions when the electron density changed from approximately N(e) almost-equal-to 1 x 10(18) to 5 x 10(18) cm-3. This effect was also observed in CIII and NV. An initial theoretical approach to the problem based on the integration of the Schrodinger equation with the ion Coulomb potential modified by the electron cloud within the Debye radius was unsuccessful in predicting the experimental observations. The effect of quenching of spontaneous emission coefficients was observed also in an Ar-ion laser as a function of the intracavity power density (photon density) for lines originating from the same upper level as the lasing line. Measurements of these line profiles, absorption for different lasing conditions, and related discussions are also presented. C1 DEPT MECH & AEROSP ENGN E QUAD,PRINCETON,NJ 08544. RP SUCKEWER, S (reprint author), PRINCETON UNIV,PLASMA PHYS LAB,PRINCETON,NJ 08544, USA. NR 14 TC 5 Z9 5 U1 1 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 AUG PY 1991 VL 3 IS 8 BP 2437 EP 2442 DI 10.1063/1.859615 PN 2 PG 6 WC Physics, Fluids & Plasmas SC Physics GA FY451 UT WOS:A1991FY45100041 ER PT J AU ASLANIDIS, C DEJONG, PJ AF ASLANIDIS, C DEJONG, PJ TI COINCIDENCE CLONING OF ALU PCR PRODUCTS SO PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF THE UNITED STATES OF AMERICA LA English DT Article DE HUMAN CHROMOSOME-19; SOMATIC CELL HYBRIDS; MYOTONIC DYSTROPHY; REGION-SPECIFIC PROBES; SUBTRACTION CLONING ID SOMATIC-CELL HYBRID; POLYMERASE CHAIN-REACTION; MYOTONIC-DYSTROPHY LOCUS; RAPID ISOLATION; HUMAN CHROMOSOME-19; DNA MARKERS; REGION; SEQUENCES; GENE; AMPLIFICATION AB Coincidence cloning allows the isolation of sequences held in common by two genomic DNA populations. Human DNA from two human-hamster hybrid cell lines was amplified by Alu-repeat primers (Alu PCR) and the products originating from the shared human chromosomal region were cloned. To achieve this, human sequences were amplified with very similar Alu primers from the two different human-hamster hybrid cell lines. The products were then digested with an appropriate restriction enzyme (either BamHI or Sal I), combined, denatured, and reannealed. The derived heteroduplex molecules (originating from the human regions common to both cell lines) had single BamHI and Sal I cohesive ends due to the primers used, so that they could be cloned in a double-digested plasmid vector. We used this method to enrich about 10-fold for Alu PCR products from the human chromosome 19ql3.2 region, resulting in a region-specific clone collection. About 90% of the recombinants with BamHI-Sal I inserts are derived from the common region. This approach allows the boundaries for the regional probe isolation to be defined by combinations of hybrids rather than single hybrid cell lines, thus permitting greater flexibility in the selection of regions for probe isolation. C1 UNIV CALIF LAWRENCE LIVERMORE NATL LAB,DIV BIOMED SCI,CTR HUMAN GENOME,L-452,LIVERMORE,CA 94550. NR 35 TC 25 Z9 26 U1 0 U2 0 PU NATL ACAD SCIENCES PI WASHINGTON PA 2101 CONSTITUTION AVE NW, WASHINGTON, DC 20418 SN 0027-8424 J9 P NATL ACAD SCI USA JI Proc. Natl. Acad. Sci. U. S. A. PD AUG PY 1991 VL 88 IS 15 BP 6765 EP 6769 DI 10.1073/pnas.88.15.6765 PG 5 WC Multidisciplinary Sciences SC Science & Technology - Other Topics GA FZ344 UT WOS:A1991FZ34400080 PM 1862100 ER PT J AU RYDBERG, B DOSANJH, MK SINGER, B AF RYDBERG, B DOSANJH, MK SINGER, B TI HUMAN-CELLS CONTAIN PROTEIN SPECIFICALLY BINDING TO A SINGLE 1,N6-ETHENOADENINE IN A DNA FRAGMENT SO PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF THE UNITED STATES OF AMERICA LA English DT Article DE VINYL CHLORIDE; SITE-SPECIFIC CARCINOGEN ADDUCT; DNA NICKING; MISMATCH RECOGNITION ID VINYL-CHLORIDE; NUCLEAR FACTOR; METABOLITE; ANTIBODIES; MISMATCHES; OXIDE AB A human DNA binding protein has been characterized from cell-free extracts of liver, placenta, and cultured cells. This protein, apparent molecular mass almost-equal-to 35 kDa, to our knowledge, does not resemble other proteins reported to bind to carcinogen-modified DNA. The probe used for characterization was a 25-base oligonucleotide containing a single site-specifically placed 1,N6-ethenoadenine (epsilon-A), a product of vinyl chloride metabolism. When annealed to form an epsilon-A.T or epsilon-A.C pair, a strong affinity to the protein was observed, with a binding constant of almost-equal-to 1 x 10(9) M-1. In contrast, very little binding was found with an epsilon-A.A pair and none was found with an epsilon-A.G pair. This suggests protein recognition of a specific structural alteration. Other defined probes with alkyl adducts did not bind. In addition, the human cell extracts and a rat liver extract were found to nick specifically at the 5' side of the epsilon-A adduct, which could indicate a possible associated repair activity. C1 UNIV CALIF BERKELEY LAWRENCE BERKELEY LAB,DIV CELL & MOLEC BIOL,DONNER LAB,BERKELEY,CA 94720. FU NCI NIH HHS [CA 47723, CA 42736, CA 52127] NR 28 TC 32 Z9 32 U1 0 U2 1 PU NATL ACAD SCIENCES PI WASHINGTON PA 2101 CONSTITUTION AVE NW, WASHINGTON, DC 20418 SN 0027-8424 J9 P NATL ACAD SCI USA JI Proc. Natl. Acad. Sci. U. S. A. PD AUG PY 1991 VL 88 IS 15 BP 6839 EP 6842 DI 10.1073/pnas.88.15.6839 PG 4 WC Multidisciplinary Sciences SC Science & Technology - Other Topics GA FZ344 UT WOS:A1991FZ34400095 PM 1862108 ER PT J AU PARETZKE, HG TURNER, JE HAMM, RN RITCHIE, RH WRIGHT, HA AF PARETZKE, HG TURNER, JE HAMM, RN RITCHIE, RH WRIGHT, HA TI SPATIAL DISTRIBUTIONS OF INELASTIC EVENTS PRODUCED BY ELECTRONS IN GASEOUS AND LIQUID WATER SO RADIATION RESEARCH LA English DT Article ID 3 NS; TRACKS; SCATTERING; RADIATION; INTERFACE; YIELDS; VAPOR; DECAY; PS C1 OAK RIDGE NATL LAB,DIV HLTH & SAFETY RES,OAK RIDGE,TN 37831. RP PARETZKE, HG (reprint author), GESELL STRAHLEN & UMWELTFORSCH MBH,INST STRAHLENSCHUTZ,W-8042 NEUHERBERG,GERMANY. NR 25 TC 34 Z9 34 U1 0 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 AUG PY 1991 VL 127 IS 2 BP 121 EP 129 DI 10.2307/3577955 PG 9 WC Biology; Biophysics; Radiology, Nuclear Medicine & Medical Imaging SC Life Sciences & Biomedicine - Other Topics; Biophysics; Radiology, Nuclear Medicine & Medical Imaging GA GA110 UT WOS:A1991GA11000001 PM 1946995 ER PT J AU CUCINOTTA, FA KATZ, R WILSON, JW TOWNSEND, LW SHINN, J HAJNAL, F AF CUCINOTTA, FA KATZ, R WILSON, JW TOWNSEND, LW SHINN, J HAJNAL, F TI BIOLOGICAL EFFECTIVENESS OF HIGH-ENERGY PROTONS - TARGET FRAGMENTATION SO RADIATION RESEARCH LA English DT Article ID RADIATION; BEAM; CELLS C1 UNIV NEBRASKA,LINCOLN,NE 68588. ROCKWELL INT CORP,DIV SPACE TRANSPORTAT SYST,HOUSTON,TX 77058. US DOE,NEW YORK,NY 10014. RP CUCINOTTA, FA (reprint author), NASA,LANGLEY RES CTR,HAMPTON,VA 23665, USA. NR 30 TC 28 Z9 28 U1 2 U2 4 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 AUG PY 1991 VL 127 IS 2 BP 130 EP 137 DI 10.2307/3577956 PG 8 WC Biology; Biophysics; Radiology, Nuclear Medicine & Medical Imaging SC Life Sciences & Biomedicine - Other Topics; Biophysics; Radiology, Nuclear Medicine & Medical Imaging GA GA110 UT WOS:A1991GA11000002 PM 1658843 ER PT J AU WATERS, LC SIKPI, MO PRESTON, RJ MITRA, S JABERABOANSARI, A AF WATERS, LC SIKPI, MO PRESTON, RJ MITRA, S JABERABOANSARI, A TI MUTATIONS INDUCED BY IONIZING-RADIATION IN A PLASMID REPLICATED IN HUMAN-CELLS .1. SIMILAR, NONRANDOM DISTRIBUTION OF MUTATIONS IN UNIRRADIATED AND X-IRRADIATED DNA SO RADIATION RESEARCH LA English DT Article ID SHUTTLE VECTOR PLASMID; INDUCED POINT MUTATIONS; MAMMALIAN-CELLS; ESCHERICHIA-COLI; MONKEY CELLS; MOLECULAR CHARACTERIZATION; XERODERMA PIGMENTOSUM; MUTAGENESIS; GENE; SPECIFICITY C1 UNIV TENNESSEE,GRAD SCH BIOMED SCI,OAK RIDGE,TN 37831. RP WATERS, LC (reprint author), OAK RIDGE NATL LAB,DIV BIOL,OAK RIDGE,TN 37831, USA. FU NCI NIH HHS [T32 CA 09336] NR 45 TC 43 Z9 43 U1 0 U2 2 PU RADIATION RESEARCH SOC PI OAK BROOK PA 2021 SPRING RD, STE 600, OAK BROOK, IL 60521 SN 0033-7587 J9 RADIAT RES JI Radiat. Res. PD AUG PY 1991 VL 127 IS 2 BP 190 EP 201 DI 10.2307/3577965 PG 12 WC Biology; Biophysics; Radiology, Nuclear Medicine & Medical Imaging SC Life Sciences & Biomedicine - Other Topics; Biophysics; Radiology, Nuclear Medicine & Medical Imaging GA GA110 UT WOS:A1991GA11000011 PM 1947004 ER PT J AU JABERABOANSARI, A DUNN, WC PRESTON, RJ MITRA, S WATERS, LC AF JABERABOANSARI, A DUNN, WC PRESTON, RJ MITRA, S WATERS, LC TI MUTATIONS INDUCED BY IONIZING-RADIATION IN A PLASMID REPLICATED IN HUMAN-CELLS .2. SEQUENCE-ANALYSIS OF ALPHA-PARTICLE-INDUCED POINT MUTATIONS SO RADIATION RESEARCH LA English DT Article ID SHUTTLE VECTOR PLASMID; DOUBLE-STRAND BREAKS; MAMMALIAN-CELLS; DEOXYRIBONUCLEIC-ACID; MONKEY CELLS; XERODERMA PIGMENTOSUM; DNA DAMAGE; MUTAGENESIS; SPECTRUM; SPECIFICITY C1 OAK RIDGE NATL LAB,DIV BIOL,OAK RIDGE,TN 37831. RP JABERABOANSARI, A (reprint author), UNIV TENNESSEE,OAK RIDGE GRAD SCH BIOMED SCI,OAK RIDGE,TN 37831, USA. FU NCI NIH HHS [T32 CA 09336] NR 41 TC 26 Z9 27 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 AUG PY 1991 VL 127 IS 2 BP 202 EP 210 DI 10.2307/3577966 PG 9 WC Biology; Biophysics; Radiology, Nuclear Medicine & Medical Imaging SC Life Sciences & Biomedicine - Other Topics; Biophysics; Radiology, Nuclear Medicine & Medical Imaging GA GA110 UT WOS:A1991GA11000012 PM 1947005 ER PT J AU JOSTES, RF HUI, TE JAMES, AC CROSS, FT SCHWARTZ, JL ROTMENSCH, J ATCHER, RW EVANS, HH MENCL, J BAKALE, G RAO, PS AF JOSTES, RF HUI, TE JAMES, AC CROSS, FT SCHWARTZ, JL ROTMENSCH, J ATCHER, RW EVANS, HH MENCL, J BAKALE, G RAO, PS TI INVITRO EXPOSURE OF MAMMALIAN-CELLS TO RADON - DOSIMETRIC CONSIDERATIONS SO RADIATION RESEARCH LA English DT Article ID ALPHA-PARTICLES; MUTAGENICITY; CYTOTOXICITY; IRRADIATION; PU-238; REPAIR C1 PACIFIC NW LAB, DEPT HLTH PHYS, RICHLAND, WA 99352 USA. ARGONNE NATL LAB, DIV BIOL & MED, ARGONNE, IL 60439 USA. ARGONNE NATL LAB, DIV CHEM, ARGONNE, IL 60439 USA. UNIV CHICAGO, DEPT RADIAT & CELLULAR ONCOL, CHICAGO, IL 60637 USA. UNIV CHICAGO, DEPT OBSTET & GYNECOL, CHICAGO, IL 60637 USA. CASE WESTERN RESERVE UNIV, DEPT RADIOL, CLEVELAND, OH 44106 USA. RP JOSTES, RF (reprint author), PACIFIC NW LAB, DEPT BIOL & CHEM, K 4-13, RICHLAND, WA 99352 USA. OI Atcher, Robert/0000-0003-4656-2247 FU NCI NIH HHS [P30 CA43703] NR 19 TC 45 Z9 45 U1 0 U2 1 PU RADIATION RESEARCH SOC PI OAK BROOK PA 2021 SPRING RD, STE 600, OAK BROOK, IL 60521 SN 0033-7587 J9 RADIAT RES JI Radiat. Res. PD AUG PY 1991 VL 127 IS 2 BP 211 EP 219 DI 10.2307/3577967 PG 9 WC Biology; Biophysics; Radiology, Nuclear Medicine & Medical Imaging SC Life Sciences & Biomedicine - Other Topics; Biophysics; Radiology, Nuclear Medicine & Medical Imaging GA GA110 UT WOS:A1991GA11000013 PM 1947006 ER PT J AU AFZAL, SMJ TENFORDE, TS KAVANAU, KS CURTIS, SB AF AFZAL, SMJ TENFORDE, TS KAVANAU, KS CURTIS, SB TI REPOPULATION KINETICS OF RAT RHABDOMYOSARCOMA TUMORS FOLLOWING SINGLE AND FRACTIONATED DOSES OF LOW-LET AND HIGH-LET RADIATION SO RADIATION RESEARCH LA English DT Note ID CELL-SURVIVAL; X-RAYS; GROWTH DELAY; NEON-ION; INVIVO; IRRADIATION; CARBON RP AFZAL, SMJ (reprint author), UNIV CALIF BERKELEY LAWRENCE BERKELEY LAB,DIV CELL & MOLEC BIOL,1 CYCLOTRON RD,BERKELEY,CA 94720, USA. FU NCI NIH HHS [CA17411, CA15184]; NCRR NIH HHS [RR 05918] NR 17 TC 5 Z9 5 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 AUG PY 1991 VL 127 IS 2 BP 230 EP 233 DI 10.2307/3577970 PG 4 WC Biology; Biophysics; Radiology, Nuclear Medicine & Medical Imaging SC Life Sciences & Biomedicine - Other Topics; Biophysics; Radiology, Nuclear Medicine & Medical Imaging GA GA110 UT WOS:A1991GA11000016 PM 1947008 ER PT J AU CURLEE, TR DAS, S AF CURLEE, TR DAS, S TI IDENTIFYING AND ASSESSING TARGETS OF OPPORTUNITY FOR PLASTICS RECYCLING SO RESOURCES CONSERVATION AND RECYCLING LA English DT Article AB This paper identifies and assesses "targets of opportunity" for additional recycling of plastic wastes. Targets are discussed in terms of the quantities of plastics wastes that might be affected, the relevant supply-side and demand-side constraints that must be overcome before these targets can be met, and the degree to which meeting these targets might be facilitated by government sponsored incentive programs or other regulatory measures. Five hypothetical scenarios are developed that depict various supply-side and demand-side conditions. In some cases, the supply-side and demand-side assumptions are consistent with current technical, economic, institutional, and regulatory conditions. In other cases, particularly with respect to supply-side constraints, the assumptions represent significant shifts in the ways plastics are collected and processed in the United States. The quantities and types of plastics that could be recycled, given the hypothetical conditions, are estimated. The viability of the assumptions in the various scenarios is also assessed. Given current conditions and expected future trends, three broad options exist to increase the percentage of plastics recycled. First, actions can be taken to promote the collection and recycling of relatively clean plastic waste. Technical constraints and the relative sizes of markets for different resins suggest that a focus on polyethylene terephthalate (PET) and high-density polyethylene (HDPE) packaging is most appropriate. Second, actions can be taken to promote the collection and recycling of commingled plastics. Third, plastics can be collected with other combustible wastes and incinerated to recover heat value. The recycling of PET and HDPE faces fewer technical, economic, and institutional constraints than does the recycling of commingled plastics. Although more risky, recycling of commingled plastics offers the opportunity to recycle a much larger percentage of the total plastics waste stream. Incineration with heat recovery could utilize all plastic wastes. The potential for incineration may, however, be limited by environmental concerns. Given the uncertainties that currently exist about these recycling approaches, a flexible public policy with respect to plastics recycling is suggested at this time. RP CURLEE, TR (reprint author), OAK RIDGE NATL LAB,DIV ENERGY,ENERGY & ECON ANAL SECT,OAK RIDGE,TN 37831, USA. NR 0 TC 11 Z9 12 U1 1 U2 8 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0921-3449 J9 RESOUR CONSERV RECY JI Resour. Conserv. Recycl. PD AUG PY 1991 VL 5 IS 4 BP 343 EP 363 DI 10.1016/0921-3449(91)90012-D PG 21 WC Engineering, Environmental; Environmental Sciences SC Engineering; Environmental Sciences & Ecology GA GE908 UT WOS:A1991GE90800003 ER PT J AU SANDER, RK ARCHULETA, F HARKER, W MARTINEZ, R QUICK, CR REEDER, R TAYLOR, DJ BRUMWELL, F HUMMER, C AF SANDER, RK ARCHULETA, F HARKER, W MARTINEZ, R QUICK, CR REEDER, R TAYLOR, DJ BRUMWELL, F HUMMER, C TI LASER-INDUCED FLUORESCENCE MEASUREMENT OF A 50-MEV HYDROGEN-ATOM BEAM SO REVIEW OF SCIENTIFIC INSTRUMENTS LA English DT Article AB laser-induced fluorescence has been used to measure the velocity, direction, and divergence of a beam of neutral hydrogen atoms traveling at 50 MeV or one-third the speed of light. The beam was produced by neutralizing a negative hydrogen ion beam in a foil stripper, which generated a fraction of the atoms in the metastable 2s state. These metastables were measured by pumping the 2s to 3p transition with a flashlamp pumped dye laser at 623 nm and detecting fluorescence in the vacuum ultraviolet from the 3p to 1s ground-state transition. C1 ARGONNE NATL LAB,ARGONNE,IL 60439. RP SANDER, RK (reprint author), UNIV CALIF LOS ALAMOS SCI LAB,LOS ALAMOS,NM 87545, USA. NR 12 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 0034-6748 J9 REV SCI INSTRUM JI Rev. Sci. Instrum. PD AUG PY 1991 VL 62 IS 8 BP 1893 EP 1898 DI 10.1063/1.1142388 PG 6 WC Instruments & Instrumentation; Physics, Applied SC Instruments & Instrumentation; Physics GA FZ316 UT WOS:A1991FZ31600001 ER PT J AU KAMPERSCHROER, JH DUDEK, LE GRISHAM, LR NEWMAN, RA OCONNOR, TE STEVENSON, TN VONHALLE, A WILLIAMS, MD WRIGHT, KE AF KAMPERSCHROER, JH DUDEK, LE GRISHAM, LR NEWMAN, RA OCONNOR, TE STEVENSON, TN VONHALLE, A WILLIAMS, MD WRIGHT, KE TI OPERATION OF A TFTR ION-SOURCE WITH A GROUND POTENTIAL GAS FEED INTO THE NEUTRALIZER SO REVIEW OF SCIENTIFIC INSTRUMENTS LA English DT Article ID FUSION TEST REACTOR; BEAM INJECTORS; SYSTEM; 120-KV AB TFTR long pulse ion sources have been operated with gas fed only into the neutralizer. Gas for the plasma generator entered through the accelerator rather than directly into the arc chamber. This modification has been proposed for tritium beam operation to locate control electronics at ground potential and to simplify tritium plumbing. Source operation with this configuration and with the nominal gas system that feeds gas into both the ion source and the center of the neutralizer are compared. Comparison is based upon accelerator grid currents, beam composition, and neutral power delivered to the calorimeter. Charge exchange in the accelerator can be a significant loss mechanism in both systems at high throughput. A suitable operating point with the proposed system was found that requires 30% less gas than used presently. The extracted D+, D2+, and D3+ fractions of the beam were found to be a function of the gas throughput; at similar throughputs, the two gas feed systems produced similar extracted ion fractions. Operation at the proposed gas efficient point results in a small reduction (relative to the old high throughput mode) in the extracted D+ fraction of the beam from 77% to 71%, with concomitant changes in the D2+ fraction from 18% to 26%, and 6% to 3% for D3+. The injected power is unchanged, approximately 2.2 MW at 95 kV. RP KAMPERSCHROER, JH (reprint author), PRINCETON UNIV,PRINCETON PLASMA PHYS LAB,PRINCETON,NJ 08543, USA. NR 24 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 0034-6748 J9 REV SCI INSTRUM JI Rev. Sci. Instrum. PD AUG PY 1991 VL 62 IS 8 BP 1964 EP 1969 DI 10.1063/1.1142400 PG 6 WC Instruments & Instrumentation; Physics, Applied SC Instruments & Instrumentation; Physics GA FZ316 UT WOS:A1991FZ31600013 ER PT J AU COMBS, SK FOUST, CR FEHLING, DT GOUGE, MJ MILORA, SL AF COMBS, SK FOUST, CR FEHLING, DT GOUGE, MJ MILORA, SL TI REPETITIVE 2-STAGE LIGHT GAS GUN FOR HIGH-SPEED PELLET INJECTION SO REVIEW OF SCIENTIFIC INSTRUMENTS LA English DT Article ID PLASMA FUELING APPLICATIONS; JOINT EUROPEAN TORUS; PIPE GUN; SYSTEM; PERFORMANCE; REACTOR AB A repetitive two-stage light gas gun for high-speed pellet injection has been developed at Oak Ridge National Laboratory. In general, applications of the two-stage light gas gun have been limited to only single shots, with a finite time (at least minutes) needed for recovery and preparation for the next shot. The new device overcomes problems associated with repetitive operation, including rapidly evacuating the propellant gases, reloading the gun breech with a new projectile, returning the piston to its initial position, and refilling the first- and second-stage gas volumes to the appropriate pressure levels. In addition, some components are subjected to and must survive severe operating conditions, which include rapid cycling to high pressures and temperatures (up to thousands of bars and thousands of kelvins) and significant mechanical shocks. Small plastic projectiles (4 mm nominal size) and helium gas have been used in the prototype device, which was equipped with a 1-m-long pump tube and a 1-m-long gun barrel, to demonstrate repetitive operation (up to 1 Hz) at relatively high pellet velocities (up to 3000 m/s). The highest experimental velocity is twice that available from conventional repeating single-stage pneumatic injectors that accelerate frozen pellets of hydrogen isotopes and are now used to fuel magnetically confined plasmas for controlled thermonuclear fusion research. Also, the pellet test repetition rate of 1 Hz is relevant for fueling applications on future large fusion research devices. The equipment is described, and experimental results are presented and compared with calculated results from gas dynamics models. RP COMBS, SK (reprint author), OAK RIDGE NATL LAB,OAK RIDGE,TN 37831, USA. NR 24 TC 4 Z9 4 U1 1 U2 2 PU AMER INST PHYSICS PI WOODBURY PA CIRCULATION FULFILLMENT DIV, 500 SUNNYSIDE BLVD, WOODBURY, NY 11797-2999 SN 0034-6748 J9 REV SCI INSTRUM JI Rev. Sci. Instrum. PD AUG PY 1991 VL 62 IS 8 BP 1978 EP 1989 DI 10.1063/1.1142402 PG 12 WC Instruments & Instrumentation; Physics, Applied SC Instruments & Instrumentation; Physics GA FZ316 UT WOS:A1991FZ31600015 ER PT J AU HOLMES, NC AF HOLMES, NC TI EQUATION-OF-STATE MEASUREMENTS OF LOW-DENSITY MATERIALS SO REVIEW OF SCIENTIFIC INSTRUMENTS LA English DT Article ID ALUMINUM; MBAR AB A precise optical method for determining the velocities of strong shock waves in low-density materials is described. Using an experiment on a polystyrene (CH) low-density microcellular material (LDMM), we also describe the analysis of the experimental data. Applications to the studies of other materials will be described. RP HOLMES, NC (reprint author), UNIV CALIF LAWRENCE LIVERMORE NATL LAB, LIVERMORE, CA 94550 USA. NR 16 TC 14 Z9 14 U1 0 U2 1 PU AMER INST PHYSICS PI MELVILLE PA 1305 WALT WHITMAN RD, STE 300, MELVILLE, NY 11747-4501 USA SN 0034-6748 EI 1089-7623 J9 REV SCI INSTRUM JI Rev. Sci. Instrum. PD AUG PY 1991 VL 62 IS 8 BP 1990 EP 1994 DI 10.1063/1.1142403 PG 5 WC Instruments & Instrumentation; Physics, Applied SC Instruments & Instrumentation; Physics GA FZ316 UT WOS:A1991FZ31600016 ER PT J AU MOYZIS, RK AF MOYZIS, RK TI THE HUMAN TELOMERE SO SCIENTIFIC AMERICAN LA English DT Article RP MOYZIS, RK (reprint author), UNIV CALIF LOS ALAMOS SCI LAB,CTR HUMAN GENOME STUDIES,LOS ALAMOS,NM 87544, USA. NR 3 TC 8 Z9 8 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 AUG PY 1991 VL 265 IS 2 BP 48 EP 55 PG 8 WC Multidisciplinary Sciences SC Science & Technology - Other Topics GA FX476 UT WOS:A1991FX47600011 PM 1862331 ER PT J AU POVIRK, GL STOUT, MG BOURKE, M GOLDSTONE, JA LAWSON, AC LOVATO, M MACEWEN, SR NUTT, SR NEEDLEMAN, A AF POVIRK, GL STOUT, MG BOURKE, M GOLDSTONE, JA LAWSON, AC LOVATO, M MACEWEN, SR NUTT, SR NEEDLEMAN, A TI MECHANICALLY INDUCED RESIDUAL-STRESSES IN AL SIC COMPOSITES SO SCRIPTA METALLURGICA ET MATERIALIA LA English DT Article ID METAL MATRIX COMPOSITES; WHISKERS C1 ALCAN INT LTD,KINGSTON RES & DEV CTR,KINGSTON K7L 5L9,ONTARIO,CANADA. UNIV CALIF LOS ALAMOS SCI LAB,LOS ALAMOS,NM 87545. RP POVIRK, GL (reprint author), BROWN UNIV,RHODE ISL HOSP,DIV ENGN,PROVIDENCE,RI 02903, USA. RI Needleman, Alan/A-1879-2008 OI Needleman, Alan/0000-0002-4697-4535 NR 14 TC 5 Z9 5 U1 0 U2 2 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 AUG PY 1991 VL 25 IS 8 BP 1883 EP 1888 DI 10.1016/0956-716X(91)90322-R PG 6 WC Materials Science, Multidisciplinary; Metallurgy & Metallurgical Engineering SC Materials Science; Metallurgy & Metallurgical Engineering GA FZ561 UT WOS:A1991FZ56100023 ER PT J AU HUANG, JS KIM, YW AF HUANG, JS KIM, YW TI CREEP DEFORMATION AND FRACTURE OF A 2-PHASE TIAL ALLOY SO SCRIPTA METALLURGICA ET MATERIALIA LA English DT Article ID TEMPERATURES C1 METCUT MAT RES GRP,WRIGHT PATTERSON AFB,OH 45433. RP HUANG, JS (reprint author), UNIV CALIF LAWRENCE LIVERMORE NATL LAB,DEPT CHEM & MAT SCI,POB 808,LIVERMORE,CA 94550, USA. NR 13 TC 31 Z9 31 U1 0 U2 5 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 AUG PY 1991 VL 25 IS 8 BP 1901 EP 1906 DI 10.1016/0956-716X(91)90325-U PG 6 WC Materials Science, Multidisciplinary; Metallurgy & Metallurgical Engineering SC Materials Science; Metallurgy & Metallurgical Engineering GA FZ561 UT WOS:A1991FZ56100026 ER PT J AU LIU, CT OLIVER, WC AF LIU, CT OLIVER, WC TI ENVIRONMENTAL EMBRITTLEMENT AND GRAIN-BOUNDARY FRACTURE IN NI3SI SO SCRIPTA METALLURGICA ET MATERIALIA LA English DT Article ID ROOM-TEMPERATURE DUCTILITY; BASE L12 ALLOYS; HYDROGEN EMBRITTLEMENT; INTERMETALLIC COMPOUND; TENSILE PROPERTIES; SINGLE-CRYSTALS; ORDERED ALLOYS; TI ELEMENTS; AL-ALLOYS; BORON RP LIU, CT (reprint author), OAK RIDGE NATL LAB,DIV MET & CERAM,OAK RIDGE,TN 37831, USA. OI Liu, Chain Tsuan/0000-0001-7888-9725 NR 51 TC 66 Z9 69 U1 0 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 AUG PY 1991 VL 25 IS 8 BP 1933 EP 1937 DI 10.1016/0956-716X(91)90331-T PG 5 WC Materials Science, Multidisciplinary; Metallurgy & Metallurgical Engineering SC Materials Science; Metallurgy & Metallurgical Engineering GA FZ561 UT WOS:A1991FZ56100032 ER PT J AU ASCHER, UM PETZOLD, LR AF ASCHER, UM PETZOLD, LR TI PROJECTED IMPLICIT RUNGE-KUTTA METHODS FOR DIFFERENTIAL-ALGEBRAIC EQUATIONS SO SIAM JOURNAL ON NUMERICAL ANALYSIS LA English DT Article DE DIFFERENTIAL-ALGEBRAIC SYSTEMS; BOUNDARY VALUE PROBLEMS; HIGHER INDEX; RUNGE-KUTTA METHODS ID NUMERICAL-SOLUTION; DIAGENETIC MODEL; POREWATERS; PH AB In this paper a new class of numerical methods, Projected Implicit Runge-Kutta methods, is introduced for the solution of index-2 Hessenberg systems of initial and boundary value differential-algebraic equations (DAEs). These types of systems arise in a variety of applications, including the modeling of singular optimal control problems and parameter estimation for differential-algebraic equations such as multibody systems. The new methods appear to be particularly promising for the solution of DAE boundary value problems, where the need to maintain stability in the differential part of the system often necessitates the use of methods based on symmetric discretizations. Previously defined symmetric methods have severe limitations when applied to these problems, including instability, oscillation, and loss of accuracy; the new methods overcome these difficulties. For linear problems we define an essential underlying boundary value ODE and prove well-conditioning of the differential (or state-space) solution components. This is then used to prove stability and superconvergence for the corresponding numerical approximations for linear and nonlinear problems. C1 UNIV CALIF LAWRENCE LIVERMORE NATL LAB,DIV COMP & MATH RES,LIVERMORE,CA 94550. RP ASCHER, UM (reprint author), UNIV BRITISH COLUMBIA,DEPT COMP SCI,VANCOUVER V6T 1W5,BC,CANADA. NR 21 TC 101 Z9 102 U1 2 U2 5 PU SIAM PUBLICATIONS PI PHILADELPHIA PA 3600 UNIV CITY SCIENCE CENTER PH#382-9800, PHILADELPHIA, PA 19104-2688 SN 0036-1429 J9 SIAM J NUMER ANAL JI SIAM J. Numer. Anal. PD AUG PY 1991 VL 28 IS 4 BP 1097 EP 1120 DI 10.1137/0728059 PG 24 WC Mathematics, Applied SC Mathematics GA FY957 UT WOS:A1991FY95700012 ER PT J AU FU, GM ALLEN, HE COWAN, CE AF FU, GM ALLEN, HE COWAN, CE TI ADSORPTION OF CADMIUM AND COPPER BY MANGANESE OXIDE SO SOIL SCIENCE LA English DT Article ID INTERFACE; LIGANDS AB Cadmium and copper adsorption by delta-MnO2 was investigated by potentiometric titration over a range of pH. Adsorption increased with increasing pH because of hydrolysis of metal cations and/or variable charge sites on delta-MnO2. The surface acidity constant for delta-MnO2 was determined using the Triple Layer Model to be pK(int,a2) = 5.34. The data from titrations with pH as master variable were analyzed to determine the Triple Layer Model intrinsic stability constants, p*K(int,Cd2+) = 0.81, p*K(int,CdOH)+ = 6.89, p*K(int,Cu2+) = 1.66, and p*K(int,CuOH+) = 3.79 for cadmium and copper adsorption onto delta-MnO2. Titrations with metal ion as the master variable were performed at constant pH to estimate the adsorption capacities. The data conformed to a Langmuir isotherm and could be modeled with the Triple Layer Model constants. For cadmium, at pH 5.5, 7.0, and 8.0, the adsorption capacity is 0.434, 1.08, and 1.92 mmol/g, respectively. The affinity of delta-MnO2 for Cu, 1.54 mmol/g at pH 5.5, is greater than that for cadmium. The results show delta-MnO2 has high adsorption capacities and high adsorption affinities for cadmium and copper even in acidic conditions. C1 DREXEL UNIV, INST ENVIRONM STUDIES, PHILADELPHIA, PA 19104 USA. PACIFIC NW LAB, RICHLAND, WA 99352 USA. NR 23 TC 86 Z9 89 U1 1 U2 12 PU WILLIAMS & WILKINS PI BALTIMORE PA 351 WEST CAMDEN ST, BALTIMORE, MD 21201-2436 SN 0038-075X J9 SOIL SCI JI Soil Sci. PD AUG PY 1991 VL 152 IS 2 BP 72 EP 81 DI 10.1097/00010694-199108000-00002 PG 10 WC Soil Science SC Agriculture GA GD621 UT WOS:A1991GD62100002 ER PT J AU MACHADO, FLA MONTENEGRO, FC REZENDE, SM MONTARROYOS, E AZEVEDO, LJ CLARK, WG AF MACHADO, FLA MONTENEGRO, FC REZENDE, SM MONTARROYOS, E AZEVEDO, LJ CLARK, WG TI SPIN-GLASS BEHAVIOR IN THE AL-MN QUASI-CRYSTALLINE ALLOYS SO SOLID STATE COMMUNICATIONS LA English DT Article AB We report dynamical scaling analysis of the ac magnetic susceptibility data for the quasicrystalline Al75Mn20Si5 alloy near the critical temperature T. The critical exponents obtained are beta = 1.0 and z-nu = 5.5. The value of beta is higher than that obtained from static scaling analysis made in the decagonal Al78Mn22 alloy which yielded beta = 0.6 and gamma = 4.4. The overall values obtained for the critical exponents are similar to those measured in canonical spin-glass systems. C1 SANDIA NATL LABS,DIV 3532,ALBUQUERQUE,NM 87185. UNIV CALIF LOS ANGELES,DEPT PHYS,LOS ANGELES,CA 90024. RP MACHADO, FLA (reprint author), UNIV FED PERNAMBUCO,DEPT FIS,BR-50739 RECIFE,PE,BRAZIL. RI Rezende, Sergio/G-4570-2014; Machado, Fernando/A-5443-2009 OI Rezende, Sergio/0000-0002-3806-411X; Machado, Fernando/0000-0002-6498-7751 NR 8 TC 1 Z9 1 U1 0 U2 1 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD, ENGLAND OX5 1GB SN 0038-1098 J9 SOLID STATE COMMUN JI Solid State Commun. PD AUG PY 1991 VL 79 IS 6 BP 469 EP 471 DI 10.1016/0038-1098(91)90032-Q PG 3 WC Physics, Condensed Matter SC Physics GA GC772 UT WOS:A1991GC77200003 ER PT J AU ELDRIDGE, JE KORNELSEN, K WANG, HH WILLIAMS, JM CROUCH, AVS WATKINS, DM AF ELDRIDGE, JE KORNELSEN, K WANG, HH WILLIAMS, JM CROUCH, AVS WATKINS, DM TI INFRARED OPTICAL-PROPERTIES OF THE 12-K ORGANIC SUPERCONDUCTOR KAPPA-(BEDT-TTF)2CU[N(CN)2]BR SO SOLID STATE COMMUNICATIONS LA English DT Article ID ELECTRONIC-PROPERTIES; SALTS; SIMILARITIES; SPECTRA; TC AB Measurements of the polarized reflectivity of kappa-(BEDT-TTF)2-Cu[N(CN)2]Br are presented, from 200 to 5500 cm-1, at temperatures between 10 and 295 K. The optical conductivities, obtained after a Kramers-Kronig analysis, are very similar to those previously reported for the 10 K superconductor kappa-(BEDT-TTF)2Cu(NCS)2, except for the clear evidence of narrower electronic bands in the Cu[N(CN)2]Br- salt. The band structure is used to account for the position of the peak that appears in the mid-infrared interband conductivity. A comparison of the frequencies of the vibrational features in this 12 K superconductor, with those in the 10 K compound, shows an increase in the normally-inactive a(g) mode frequencies and a decrease in the normally-active b(u) mode frequencies. These can be related to the larger unit cell of the Cu[N(CN)2]Br- salt which produces a softer lattice and narrower electronic bands, which in turn lead to a higher superconducting transition temperature. C1 ARGONNE NATL LAB,DIV CHEM,ARGONNE,IL 60439. ARGONNE NATL LAB,DIV MAT SCI,ARGONNE,IL 60439. RP ELDRIDGE, JE (reprint author), UNIV BRITISH COLUMBIA,DEPT PHYS,VANCOUVER V6T 2A6,BC,CANADA. NR 15 TC 73 Z9 73 U1 2 U2 7 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD, ENGLAND OX5 1GB SN 0038-1098 J9 SOLID STATE COMMUN JI Solid State Commun. PD AUG PY 1991 VL 79 IS 7 BP 583 EP 589 DI 10.1016/0038-1098(91)90914-H PG 7 WC Physics, Condensed Matter SC Physics GA GE200 UT WOS:A1991GE20000008 ER PT J AU SHEN, ZX LIST, RS DESSAU, DS ARKO, AJ BARTTLET, R JEPSEN, O WELLS, BO PARMIGIANI, F AF SHEN, ZX LIST, RS DESSAU, DS ARKO, AJ BARTTLET, R JEPSEN, O WELLS, BO PARMIGIANI, F TI ANGLE RESOLVED PHOTOEMISSION OF NIO(001) SO SOLID STATE COMMUNICATIONS LA English DT Article ID SUPERCONDUCTIVITY; NIO AB We report off-normal angle-resolved photoemission data from NiO(001), which is complementary to the earlier normal-emission result. On the one hand, the energy position of the bands along this direction and the dispersion of the lowest oxygen band agree with the band calculation very well. On the other hand, the existence of the valence band satellite and the absence of the energy band in the gap region do not agree with the band calculation. For the first time, interesting movement of the Ni d7 satellite has been observed as a function of the emission angle and the photon energy, which is most likely a result of the satellite dispersion. C1 UNIV CALIF LOS ALAMOS SCI LAB,LOS ALAMOS,NM 87545. MAX PLANCK INST SOLID STATE RES,STUTTGART,GERMANY. IBM CORP,ALMADEN RES CTR,DIV RES,SAN JOSE,CA 95120. RP SHEN, ZX (reprint author), STANFORD UNIV,STANFORD ELECTR LABS,STANFORD,CA 94305, USA. OI Parmigiani, Fulvio/0000-0001-9529-7406 NR 11 TC 8 Z9 8 U1 0 U2 3 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD, ENGLAND OX5 1GB SN 0038-1098 J9 SOLID STATE COMMUN JI Solid State Commun. PD AUG PY 1991 VL 79 IS 7 BP 623 EP 628 DI 10.1016/0038-1098(91)90920-Q PG 6 WC Physics, Condensed Matter SC Physics GA GE200 UT WOS:A1991GE20000014 ER PT J AU HUMLICEK, J KIRCHER, J HABERMEIER, HU CARDONA, M FANG, Y WELP, U VANDERWOORT, K CRABTREE, D AF HUMLICEK, J KIRCHER, J HABERMEIER, HU CARDONA, M FANG, Y WELP, U VANDERWOORT, K CRABTREE, D TI FREE-CARRIER OPTICAL-RESPONSE OF YBA2CU3O7 SO SOLID STATE COMMUNICATIONS LA English DT Article ID SUPERCONDUCTING ENERGY-GAP; UNTWINNED YBA2CU3O7-DELTA; DIELECTRIC FUNCTION; ANISOTROPY; CRYSTALS AB We have determined the anisotropic optical response of YBa2Cu3O7 in the 0.75-2 eV range using ellipsometry on a (110) oriented film and an untwinned crystal. The free-carrier contributions within the CUO2 planes and CuO chains are represented excellently by orientation-dependent Drude terms with constant scattering rates. The response in the direction perpendicular to the CuO2 planes is non-metallic in our spectral region; a broad band centered at approximately 1.5 eV has strength comparable with the in-plane interband contributions obtained by subtracting the Drude terms. C1 MASARYK UNIV,DEPT SOLID STATE PHYS,CS-61137 BRNO,CZECHOSLOVAKIA. ARGONNE NATL LAB,ARGONNE,IL 60439. RP HUMLICEK, J (reprint author), MAX PLANCK INST FESTKORPERFORSCH,HEISENBERGSTR 1,W-7000 STUTTGART,GERMANY. RI Humlicek, Josef/G-5245-2014 NR 16 TC 19 Z9 19 U1 0 U2 2 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD, ENGLAND OX5 1GB SN 0038-1098 J9 SOLID STATE COMMUN JI Solid State Commun. PD AUG PY 1991 VL 79 IS 8 BP 673 EP 676 DI 10.1016/0038-1098(91)90611-X PG 4 WC Physics, Condensed Matter SC Physics GA GE594 UT WOS:A1991GE59400008 ER PT J AU RONG, FC BUCHWALD, WR POINDEXTER, EH WARREN, WL KEEBLE, DJ AF RONG, FC BUCHWALD, WR POINDEXTER, EH WARREN, WL KEEBLE, DJ TI SPIN-DEPENDENT SHOCKLEY-READ RECOMBINATION OF ELECTRONS AND HOLES IN INDIRECT-BAND-GAP SEMICONDUCTOR P-N-JUNCTION DIODES SO SOLID-STATE ELECTRONICS LA English DT Article ID MAGNETIC-RESONANCE; DEEP-LEVEL; SILICON; INTERFACE; DEFECT AB This paper presents a new model for spin-dependent recombination and generation processes based on the electrical detection of magnetic resonance in semiconductor p-n junction diodes. Based on a modified Shockley-Read recombination statistics, this model differs from those models previously proposed in that the spin-dependent enhancement of free-carrier capture processes can occur directly at a paramagnetic deep defect without the need for other defects nearby. This model incorporates singlet-triplet mechanisms of existing models, but is shown to be consistent with new experimental results which indicate the absence of any adjacent trapping centers. C1 SANDIA NATL LABS,ALBUQUERQUE,NM 87185. USA,COMMAND LAB,ELECTR TECHNOL & DEVICES LAB,FT MONMOUTH,NJ 07703. MICHIGAN TECHNOL UNIV,DEPT PHYS,HOUGHTON,MI 49931. RI Keeble, David /C-6633-2012 OI Keeble, David /0000-0002-5378-799X NR 19 TC 48 Z9 48 U1 1 U2 2 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD, ENGLAND OX5 1GB SN 0038-1101 J9 SOLID STATE ELECTRON JI Solid-State Electron. PD AUG PY 1991 VL 34 IS 8 BP 835 EP 841 DI 10.1016/0038-1101(91)90229-R PG 7 WC Engineering, Electrical & Electronic; Physics, Applied; Physics, Condensed Matter SC Engineering; Physics GA FY094 UT WOS:A1991FY09400006 ER PT J AU DUNLAP, RA OHANDLEY, RC MCHENRY, ME SRINIVAS, V AF DUNLAP, RA OHANDLEY, RC MCHENRY, ME SRINIVAS, V TI MAGNETIC-PROPERTIES OF QUASI-CRYSTALS - EFFECTS OF DISORDER ON FE MAGNETIC-MOMENT FORMATION SO STRUCTURAL CHEMISTRY LA English DT Article ID MN-SI ALLOYS; TRANSITION-METAL ALLOYS; PHYSICAL-PROPERTIES; LOCAL ENVIRONMENT; QUASI-CRYSTALS; GE ALLOYS; MOSSBAUER; AL65CU20FE15 AB Aluminum-based icosahedral quasicrystals display a wide variety of magnetic behaviors, which result from the presence of chromium, manganese, or iron. The formation of localized Fe magnetic moments in these materials is discussed in the context of the intrinsic disorder present in these structures as well as structural disorder caused by processing conditions. C1 MIT,DEPT MAT SCI & ENGN,CAMBRIDGE,MA 02139. UNIV CALIF LOS ALAMOS SCI LAB,LOS ALAMOS,NM 87545. RP DUNLAP, RA (reprint author), DALHOUSIE UNIV,DEPT PHYS,HALIFAX B3H 3J5,NS,CANADA. RI McHenry, Michael/B-8936-2009 NR 37 TC 7 Z9 7 U1 0 U2 0 PU PLENUM PUBL CORP PI NEW YORK PA 233 SPRING ST, NEW YORK, NY 10013 SN 1040-0400 J9 STRUCT CHEM JI Struct. Chem. PD AUG PY 1991 VL 2 IS 5 BP 501 EP 505 DI 10.1007/BF00672882 PG 5 WC Chemistry, Multidisciplinary; Chemistry, Physical; Crystallography SC Chemistry; Crystallography GA FZ057 UT WOS:A1991FZ05700006 ER PT J AU KULLBERG, ML LANAGAN, MT WU, W POEPPEL, RB AF KULLBERG, ML LANAGAN, MT WU, W POEPPEL, RB TI A SOL-GEL METHOD FOR PREPARING ORIENTED YBA2CU3O7-DELTA FILMS ON SILVER SUBSTRATES SO SUPERCONDUCTOR SCIENCE & TECHNOLOGY LA English DT Article ID SUPERCONDUCTING OXIDE FILM; SPRAY PYROLYSIS; THIN-FILMS; ORIENTATION; PRECURSORS AB YBa2Cu3O7-delta (YBCO) superconducting films on polycrystalline silver substrates have been fabricated using a sol-gel/spray pyrolysis method. The sol-gel precursor is composed of yttrium, barium and copper acetates that are dissolved in a minimum amount of water and partially gelled using ethanolamine. Silver substrates were heated to 300-degrees-C before spray-coating with the precursor solution. Intermittent treatment of films at 550-degrees-C in air between spray coats resulted in dense films. Subsequently, the YBCO films were sintered between 850 and 950-degrees-C and oxygen annealed on cool down. Film thicknesses of 1-3-mu-m were obtained and were highly oriented with the c axis perpendicular to the silver surface. Critical current densities (J(c)) of 200-500 A cm-2 have been measured at 77 K and no applied magnetic field; higher J(c) values have been measured on films with many pin holes, which appear to increase the number of oxygen entry points into the oriented films. The J(c) rapidly decreases in magnetic field, which indicates that transport properties are dominated by weak-link behaviour. C1 ARGONNE NATL LAB,ARGONNE,IL 60439. RP KULLBERG, ML (reprint author), AMOCO CHEM CO,NAPERVILLE,IL 60540, USA. NR 37 TC 21 Z9 23 U1 0 U2 5 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 AUG PY 1991 VL 4 IS 8 BP 337 EP 342 DI 10.1088/0953-2048/4/8/003 PG 6 WC Physics, Applied; Physics, Condensed Matter SC Physics GA GN237 UT WOS:A1991GN23700003 ER PT J AU KOSKINEN, J ANTTILA, A HIRVONEN, JP AF KOSKINEN, J ANTTILA, A HIRVONEN, JP TI DIAMOND-LIKE CARBON COATINGS BY ARC-DISCHARGE METHODS SO SURFACE & COATINGS TECHNOLOGY LA English DT Article AB Pulsed arc-discharge deposition has been used to prepare diamond-like carbon (DLC) films on various substrates. Both direct and curved plasma methods have been used. Coatings with excellent tribological properties and good adhesion have been demonstrated. The coefficient of friction of diamond-like films against a Si3N4 ball was between 0.045 and 0.084 which is an order of magnitude smaller than for most other materials. The corresponding wear coefficient was between 0.5 x 10(-16) and 1.7 x 10(-16)m3 N m-1. The diamond-like films produced using mass-separated ion beams seem to be similar in structure and properties except that the arc-discharge deposited films suffer from graphite particles on the depositions, even when using a curved solenoid. C1 UNIV CALIF LOS ALAMOS SCI LAB, DIV MAT SCI & TECHNOL, LOS ALAMOS, NM 87545 USA. RP KOSKINEN, J (reprint author), UNIV HELSINKI, ACCELERATOR LAB, SF-00170 HELSINKI 17, FINLAND. RI Koskinen, Jari/J-3886-2014 NR 10 TC 41 Z9 44 U1 0 U2 2 PU ELSEVIER SCIENCE SA PI LAUSANNE PA PO BOX 564, 1001 LAUSANNE, SWITZERLAND SN 0257-8972 J9 SURF COAT TECH JI Surf. Coat. Technol. PD AUG PY 1991 VL 47 IS 1-3 BP 180 EP 187 DI 10.1016/0257-8972(91)90280-A PG 8 WC Materials Science, Coatings & Films; Physics, Applied SC Materials Science; Physics GA GD453 UT WOS:A1991GD45300020 ER PT J AU PAN, LS KANIA, DR PIANETTA, P LANDSTRASS, M LANDEN, OL PLANO, LS AF PAN, LS KANIA, DR PIANETTA, P LANDSTRASS, M LANDEN, OL PLANO, LS TI PHOTOCONDUCTIVE MEASUREMENTS ON MICROWAVE-ASSISTED PLASMA-ENHANCED CHEMICALLY VAPOR-DEPOSITED DIAMOND FILMS SO SURFACE & COATINGS TECHNOLOGY LA English DT Article; Proceedings Paper CT 1ST EUROPEAN CONF ON DIAMOND AND DIAMOND-LIKE CARBON COATINGS CY SEP 17-19, 1990 CL CRANS-MONTANA, SWITZERLAND SP COMMISS EUROPEAN COMMUNITIES, ATOM ENERGY AUTHORITY TECHNOL, HARWELL LAB ID RADIATION AB Intrinsic photoconductivity is studied in microwave plasma-enhanced chemically vapor deposited polycrystalline diamond thin films. Two excitation sources are used to excite free carriers: a mode-locked Nd:YAG laser producing UV pulses 3-5 ps in duration of energy 6.2 eV, and a synchrotron source producing 350 ps pulses of broad band X-rays with energy less than 2.5 keV. Both sources are used to study 3-6-mu-m thick polycrystalline diamond films grown by microwave plasma chemical vapor deposition. The procedure used to prepare the films is described. Values for the carrier mobility and lifetime have been extracted from the results. The lifetimes are very short (less than 50 ps), probably because of the high density of defects within the crystallites. The mobility is considerably higher than that reported earlier on diamond films. We extracted a value of approximately 60 cm2 V-1 s-1 at a field of 10(3) V cm-1. The photoresponse of the microwave films as a function of induced carrier density is similar to that of natural diamonds. Specifically, carrier-carrier scattering reduces the mobility at high densities. RP PAN, LS (reprint author), STANFORD SYNCHROTRON RADIAT LAB,SLAC BIN 99,POB 4349,STANFORD,CA 94309, USA. NR 16 TC 3 Z9 3 U1 1 U2 3 PU ELSEVIER SCIENCE SA LAUSANNE PI LAUSANNE 1 PA PO BOX 564, 1001 LAUSANNE 1, SWITZERLAND SN 0257-8972 J9 SURF COAT TECH JI Surf. Coat. Technol. PD AUG PY 1991 VL 47 IS 1-3 BP 356 EP 364 DI 10.1016/0257-8972(91)90301-C PG 9 WC Materials Science, Coatings & Films; Physics, Applied SC Materials Science; Physics GA GD453 UT WOS:A1991GD45300041 ER PT J AU SIMONSON, RJ PAFFETT, MT JONES, ME KOEL, BE AF SIMONSON, RJ PAFFETT, MT JONES, ME KOEL, BE TI A VIBRATIONAL STUDY OF BORAZINE ADSORBED ON PT(111) AND AU(111) SURFACES SO SURFACE SCIENCE LA English DT Article ID SPECTROSCOPY; ADSORPTION AB Borazine (B3N3H6) adsorption and reaction on Pt(111) and Au(111) substrates at 100-1000 K has been investigated using thermal desorption mass spectroscopy (TDMS), ultraviolet photoelectron spectroscopy (UPS), and high-resolution electron energy loss spectroscopy (HREELS). Submonolayer coverages of borazine decompose on Pt(111) and only H2 desorption is observed upon heating. Multilayer borazine desorption occurs near 150 K, with an activation energy, E(d) = 7.3 kcal/mol. The H2 desorption peaks at 300 K are followed by a very broad desorption tail extending to 900 K, which is attributed to dehydrogenation of borazine molecular fragments. In contrast, molecular adsorption of borazine on Au(111) at 110 K is thermally reversible. Molecular borazine desorption from Au(111) occurs at 206 K with E(d) = 12 kcal/mol. The HREELS data show an unusual vertical orientation of the adsorbed borazine ring on Pt(111) at low temperature (170 K), but indicate a binding geometry for which the plane of the ring is parallel to the Au(111) surface. Possible reasons for the striking orientational difference in adsorption geometry and reactivity on these two metals are discussed. RP SIMONSON, RJ (reprint author), UNIV CALIF LOS ALAMOS SCI LAB,LOS ALAMOS,NM 87545, USA. RI Koel, Bruce/H-3857-2013 OI Koel, Bruce/0000-0002-0032-4991 NR 23 TC 15 Z9 15 U1 1 U2 10 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0039-6028 J9 SURF SCI JI Surf. Sci. PD AUG PY 1991 VL 254 IS 1-3 BP 29 EP 44 DI 10.1016/0039-6028(91)90635-6 PG 16 WC Chemistry, Physical; Physics, Condensed Matter SC Chemistry; Physics GA GC429 UT WOS:A1991GC42900019 ER PT J AU OVERBURY, SH MULLINS, DR PAFFETT, MT KOEL, BE AF OVERBURY, SH MULLINS, DR PAFFETT, MT KOEL, BE TI SURFACE-STRUCTURE DETERMINATION OF SN DEPOSITED ON PT(111) BY LOW-ENERGY ALKALI ION-SCATTERING SO SURFACE SCIENCE LA English DT Article ID ULTRAHIGH-VACUUM; ALLOYS; ADSORPTION; LEAD; TIN; CHEMISORPTION; OVERLAYERS; CATALYSTS AB Surface structures resulting from the deposition and annealing of Sn on Pt(111) and exhibiting p(2 x 2) and p(square-root 3 x square-root 3)-R30-degrees LEED patterns have been studied by low energy alkali ion scattering. Azimuthal and polar incident angle dependencies were measured for 500 and 1000 eV Li+ ions scattered from the clean and Sn covered surfaces. Shadowing and blocking effects adequately describe the single scattering from the clean Pt surface. The data support a structural model in which the Sn is incorporated into the Pt surface rather than existing as an overlayer. Analysis of the Sn angle dependence indicates that the Sn is not coplanar with the Pt but is protruding 0.022 +/- 0.005 nm above the surface. The results are compared with related metal-on-metal systems. C1 UNIV CALIF LOS ALAMOS SCI LAB,LOS ALAMOS,NM 87545. UNIV SO CALIF,LOS ANGELES,CA 90089. RP OVERBURY, SH (reprint author), OAK RIDGE NATL LAB,OAK RIDGE,TN 37831, USA. RI Koel, Bruce/H-3857-2013; Overbury, Steven/C-5108-2016 OI Koel, Bruce/0000-0002-0032-4991; Overbury, Steven/0000-0002-5137-3961 NR 20 TC 118 Z9 118 U1 4 U2 10 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0039-6028 J9 SURF SCI JI Surf. Sci. PD AUG PY 1991 VL 254 IS 1-3 BP 45 EP 57 DI 10.1016/0039-6028(91)90636-7 PG 13 WC Chemistry, Physical; Physics, Condensed Matter SC Chemistry; Physics GA GC429 UT WOS:A1991GC42900020 ER PT J AU PEDEN, CHF GOODMAN, DW WEISEL, MD HOFFMANN, FM AF PEDEN, CHF GOODMAN, DW WEISEL, MD HOFFMANN, FM TI INSITU FT-IRAS STUDY OF THE CO OXIDATION REACTION OVER RU(001) .1. EVIDENCE FOR AN ELEY-RIDEAL MECHANISM AT HIGH-PRESSURES SO SURFACE SCIENCE LA English DT Article ID CARBON-MONOXIDE OXIDATION; CATALYTIC-OXIDATION; VIBRATIONAL SPECTROSCOPY; SUPPORTED RHODIUM; PT(111) SURFACE; MOLECULAR-BEAM; NOBLE-METALS; OXYGEN; KINETICS; TEMPERATURE AB Utilizing time-resolved Fourier Transform Reflection Absorption-Infrared Spectroscopy (FT-IRAS), we have investigated the CO oxidation reaction on a Ru(001) surface in-situ at high pressures. The vibrational spectra allow us to characterize the nature of the surface during reaction and qualitatively determine steady-state coverages of CO and oxygen. Under oxidizing conditions (CO/O2 ratios < 1) where the reaction rate is highest, the surface is found to be covered with a monolayer (ML) of oxygen [O-(1 x 1)-Ru(001)]. Little, if any CO (theta-CO < 0.01) was found to adsorb at these surfaces under high-pressure steady-state conditions at 500 K, or at 85 K in UHV. From this latter result, we estimate an upper limit of E(ads)(CO) < 10 kcal/mol, and for high-pressure reaction at 500 K, CO coverages of theta-CO < 10(-5) and residence times of tau-CO < 10(-11) s. Under reducing conditions (CO/O2 ratios > 2), the steady-state coverage of oxygen decreases with decreasing oxygen partial pressure concurrent with a large reduction in reaction rates. Vibrational data reveal a steady-state coverage of CO (theta-CO almost-equal-to 0.11, E(ads)(CO) almost-equal-to 25 kcal/mol) adsorbed on an O-(2x1)-Ru(001) surface (theta-O = 0.5). Severely reducing conditions lead to low steady-state oxygen coverages < 1/2 ML and island formation of oxygen. The implications of the various CO species and of the oxygen island formation are discussed in relation to the reaction mechanisms suggested by our previous kinetic study. In particular, we propose for reaction under oxidizing conditions an Eley-Rideal mechanism involving reaction between gas-phase or weakly adsorbed CO and the O-(1 x 1)-Ru(001) surface. Under reducing conditions on the O-(2 x 1) surface the reactions proceed via a Langmuir-Hinshelwood mechanism between chemisorbed CO and oxygen. C1 EXXON RES & ENGN CO,CORP RES SCI LABS,ANNANDALE,NJ 08801. RP PEDEN, CHF (reprint author), SANDIA NATL LABS,POB 5800,ALBUQUERQUE,NM 87185, USA. OI Peden, Charles/0000-0001-6754-9928 NR 36 TC 105 Z9 105 U1 1 U2 28 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0039-6028 J9 SURF SCI JI Surf. Sci. PD AUG PY 1991 VL 253 IS 1-3 BP 44 EP 58 DI 10.1016/0039-6028(91)90580-L PG 15 WC Chemistry, Physical; Physics, Condensed Matter SC Chemistry; Physics GA GB311 UT WOS:A1991GB31100010 ER PT J AU HOFFMANN, FM WEISEL, MD PEDEN, CHF AF HOFFMANN, FM WEISEL, MD PEDEN, CHF TI INSITU FT-IRAS STUDY OF THE CO OXIDATION REACTION OVER RU(001) .2. COADSORPTION OF CARBON-MONOXIDE AND OXYGEN SO SURFACE SCIENCE LA English DT Article ID RUTHENIUM 001 SURFACE; REFLECTION-ABSORPTION-SPECTROSCOPY; HIGH-PRESSURES; ADSORPTION; POTASSIUM; KINETICS AB Utilizing time-resolved Fourier Transform Reflection Absorption-Infrared Spectroscopy (FT-IRAS), Thermal Desorption Mass Spectrometry (TDMS), and Low-Energy Electron Diffraction (LEED), we have investigated the coadsorption of CO and O on a Ru(001) surface under UHV conditions. Preadsorption of oxygen is found to weaken the adsorption energy of CO from 38 kcal/mol (clean Ru) to < 11 kcal/mol (theta-O --> 1). Co adsorption on the O-(1 x 1) monolayer is suppressed completely even at 85 K. Vibrational data show in agreement with earlier work that this reduction in the adsorption energy results from a reduction of back-donation from the metal substrate into the 2-pi-*-orbital of CO. Vibrational and thermal desorption data show the existence of distinctly different CO adsorption states on the O-(2 x 2) and O-(2 x 2) surfaces, where CO is found to order in linear on-top sites with identical (2 x 2) structures, but with different numbers of oxygen neighbors surrounding each CO molecule. Infrared lineshapes reveal a high degree of CO ordering on the O-(2 x 2) surface in contrast to the O-(2 x 1) surface which appears to be less well ordered. At higher CO coverage in both cases a compressed CO layer is observed with drastically reduced adsorption energy and the additional occupation of bridging adsorption sites. At intermediate oxygen coverages mixed phases of clean Ru, O-(2 x 2) and O-(2 x 1) are observed. Vibrational coupling observed at higher CO coverage, however, suggests rather small domain sizes. C1 SANDIA NATL LABS,ALBUQUERQUE,NM 87185. RP HOFFMANN, FM (reprint author), EXXON RES & ENGN CO,CORP RES SCI LABS,ANNANDALE,NJ 08801, USA. OI Peden, Charles/0000-0001-6754-9928 NR 23 TC 82 Z9 82 U1 1 U2 19 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0039-6028 J9 SURF SCI JI Surf. Sci. PD AUG PY 1991 VL 253 IS 1-3 BP 59 EP 71 DI 10.1016/0039-6028(91)90581-C PG 13 WC Chemistry, Physical; Physics, Condensed Matter SC Chemistry; Physics GA GB311 UT WOS:A1991GB31100011 ER PT J AU NASCENTE, PAP VANHOVE, MA SOMORJAI, GA AF NASCENTE, PAP VANHOVE, MA SOMORJAI, GA TI INDUCED ORDERING OF ETHYLIDYNE ON THE PD(111) SURFACE BY THE PREADSORPTION OF OXYGEN - A LEED AND HREELS STUDY SO SURFACE SCIENCE LA English DT Article ID ENERGY ELECTRON-DIFFRACTION; SINGLE-CRYSTAL SURFACES; CARBON-MONOXIDE; PALLADIUM SURFACES; LOSS SPECTROSCOPY; VIBRATIONAL SPECTROSCOPY; BENZENE CHEMISORPTION; COADSORBED BENZENE; INTENSITY ANALYSIS; TEMPERATURE PHASE AB Overlayers of oxygen coadsorbed with acetylene and ethylene on a Pd(111) surface were studied by low-energy electron diffraction (LEED) and high-resolution electron-energy-loss spectroscopy (HREELS) in the temperature range 150-320 K. Low temperature adsorption of both C2H2 and C2H4 resulted in non-dissociatively chemisorbed molecules, and the preadsorption of oxygen did not change the LEED or HREELS data. At room temperature both C2H2 and C2H4 formed ethylidyne (C2H3), which poorly ordered in a (square-root 3 x square-root 3)R30-degrees structure. We found that preadsorption of oxygen induced better ordering for C2H3 formed from acetylene exposure, but not for C2H3 derived from ethylene adsorption. We propose that preadsorbed oxygen helped the ordering of the C2H3 overlayer by: (a) efficiently removing surface hydrogen and (b) attractively interacting with C2H3 to give coadsorbate induced ordering. C1 UNIV CALIF BERKELEY,DEPT CHEM,BERKELEY,CA 94720. RP NASCENTE, PAP (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 57 TC 21 Z9 21 U1 1 U2 7 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0039-6028 J9 SURF SCI JI Surf. Sci. PD AUG PY 1991 VL 253 IS 1-3 BP 167 EP 176 DI 10.1016/0039-6028(91)90590-O PG 10 WC Chemistry, Physical; Physics, Condensed Matter SC Chemistry; Physics GA GB311 UT WOS:A1991GB31100020 ER PT J AU LIU, CL COHEN, JM ADAMS, JB VOTER, AF AF LIU, CL COHEN, JM ADAMS, JB VOTER, AF TI EAM STUDY OF SURFACE SELF-DIFFUSION OF SINGLE ADATOMS OF FCC METALS NI, CU, AL, AG, AU, PD, AND PT SO SURFACE SCIENCE LA English DT Article ID EMBEDDED-ATOM-METHOD; MOLECULAR-DYNAMICS; PLATINUM SURFACES; TRANSITION-METALS; 110 SURFACES; CLUSTERS; ENERGIES; IRIDIUM; GOLD; IR AB Self-diffusion of single adatoms on the (100), (110), (111), (311), and (331) surfaces of fcc metals is investigated with the embedded atom method (EAM). The general trend of activation energies for these surfaces is consistent with experimental observations. The calculated activation energies for Ni are in excellent agreement with experimental data, but those for Al and Pt differ from experimental values by up to a factor of 3. The estimated pre-exponential factors are in the range of 10(-4)-10(-2) cm2/s, in good agreement with experiment. C1 UNIV CALIF LOS ALAMOS SCI LAB,DIV THEORET,LOS ALAMOS,NM 87545. RP LIU, CL (reprint author), UNIV ILLINOIS,DEPT MAT SCI & ENGN,URBANA,IL 61801, USA. NR 54 TC 413 Z9 423 U1 10 U2 84 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0039-6028 J9 SURF SCI JI Surf. Sci. PD AUG PY 1991 VL 253 IS 1-3 BP 334 EP 344 DI 10.1016/0039-6028(91)90604-Q PG 11 WC Chemistry, Physical; Physics, Condensed Matter SC Chemistry; Physics GA GB311 UT WOS:A1991GB31100034 ER PT J AU SHUSTOROVICH, E BELL, AT AF SHUSTOROVICH, E BELL, AT TI AN ANALYSIS OF METHANOL SYNTHESIS FROM CO AND CO2 ON CU AND PD SURFACES BY THE BOND-ORDER-CONSERVATION MORSE-POTENTIAL APPROACH SO SURFACE SCIENCE LA English DT Article ID UNSUPPORTED COPPER-CATALYSTS; TRANSITION-METAL SURFACES; BOC-MP APPROACH; PALLADIUM CATALYSTS; SPECTROSCOPIC EVIDENCE; C-2 HYDROCARBONS; CARBON-MONOXIDE; SYNTHESIS GAS; OXYGEN; HYDROGENATION AB The mechanisms of methanol synthesis from CO and CO2 on Cu(111) and Pd(111) have been analyzed using the BOC-MP (bond-order-conservation-Morse-potential) approach. The analysis was based on calculations of the heats of chemisorption, Q, for all adsorbed species and the activation barriers, DELTA-E*, for all elementary reactions believed to be involved in the synthesis of methanol from CO and CO2. The relevant experimental values of Q and DELTA-E*, although scarce, agree well with the BOC-MP estimates. The formyl and formate routes to methanol were compared. On Cu(111), the activation barrier for hydrogenation of CO(s) to HCO(s) is found to be much larger than that for the desorption of CO(s), which makes formyl formation non-competitive. By contrast, on Pd(111) the two barriers are calculated to be practically equal, making it very likely that formyl groups are formed. In the presence of OH(s) groups, formate formation via the reaction CO(s) + OH(s) --> HCOO(s) is found to have a low activation barrier, particularly on Cu(111), where the formate route to methanol is preferred. The rate determining step in this case is projected to be the hydrogenolysis of formate groups to form formaldehyde and atomic oxygen. On Cu(111) the formate route also appears to be efficient for the hydrogenation of CO2 to methanol, since the activation barrier for H(s) + CO2,s --> HCOO(s) is calculated to be smaller than that for desorption of CO2,s. The reverse is true for Pd(111), which makes the formate route to methanol energetically unfavorable in this case. The mechanism of the WGS reaction has also been considered. It appears that the reaction does not proceed via the formate intermediate, and the rate-determining step for this reaction is projected to be the dissociation of water. On Cu(111), the reverse WGS reaction is found to be competitive with methanol formation. The BOC-MP projections are generally consistent with the observed features of hydrogenation of CO and CO2 on Cu and Pd catalysts. Some apparent inconsistencies are pointed out and discussed. C1 UNIV CALIF BERKELEY LAWRENCE BERKELEY LAB,CTR ADV MAT,BERKELEY,CA 94720. UNIV CALIF BERKELEY,DEPT CHEM ENGN,BERKELEY,CA 94720. RP SHUSTOROVICH, E (reprint author), EASTMAN KODAK CO,CORP RES LABS,ROCHESTER,NY 14650, USA. OI Bell, Alexis/0000-0002-5738-4645 NR 45 TC 57 Z9 60 U1 0 U2 14 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0039-6028 J9 SURF SCI JI Surf. Sci. PD AUG PY 1991 VL 253 IS 1-3 BP 386 EP 394 DI 10.1016/0039-6028(91)90609-V PG 9 WC Chemistry, Physical; Physics, Condensed Matter SC Chemistry; Physics GA GB311 UT WOS:A1991GB31100039 ER PT J AU STRONGIN, D MOWLEM, J AF STRONGIN, D MOWLEM, J TI A NEXAFS STUDY ON THE ADSORPTION OF AMMONIA ON CLEAN AND POTASSIUM-PROMOTED IRON SO SURFACE SCIENCE LA English DT Letter ID K-SHELL EXCITATION; GAS-PHASE; SURFACE; NH3; DECOMPOSITION; RESONANCES; FE(110); SPECTRA; PT(111); NA AB The adsorption of ammonia on thin films of iron with and without potassium has been investigated with near-edge X-ray absorption fine-structure (NEXAFS) and X-ray photoelectron spectroscopy (XPS). The NEXAFS results suggest that for low coverages of chemisorbed ammonia on iron there is a dilation of the N-H bond length with respect to solid ammonia. At higher ammonia coverages there is less perturbation of NH3, as inferred from NEXAFS and XPS experiments, suggesting that the adsorption energy of the ammonia is a strong function of surface coverage. The coadsorption of potassium metal is found to prevent the ammonia N-H bond dilation observed over clean iron. C1 BROOKHAVEN NATL LAB,NATL SYNCHROTRON LIGHT SOURCE,UPTON,NY 11973. RP STRONGIN, D (reprint author), SUNY STONY BROOK,DEPT CHEM,STONY BROOK,NY 11794, USA. NR 20 TC 1 Z9 1 U1 0 U2 7 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0039-6028 J9 SURF SCI JI Surf. Sci. PD AUG PY 1991 VL 253 IS 1-3 BP L417 EP L422 PG 6 WC Chemistry, Physical; Physics, Condensed Matter SC Chemistry; Physics GA GB311 UT WOS:A1991GB31100005 ER PT J AU EASTERLING, RG MAZUMDAR, M SPENCER, FW DIEGERT, KV AF EASTERLING, RG MAZUMDAR, M SPENCER, FW DIEGERT, KV TI SYSTEM-BASED COMPONENT-TEST PLANS AND OPERATING CHARACTERISTICS - BINOMIAL DATA SO TECHNOMETRICS LA English DT Article DE COMPONENT TESTING; RELIABILITY ALLOCATION; SYSTEM RELIABILITY AB Component-test plans are often designed by allocating system reliability among the system's components, then choosing individual component plans suitable for demonstrating achievement of each component's reliability goal. This approach does not consider how much information relative to the system reliability goal is provided by the ensemble of component tests. We consider the notion of system reliability operating characteristic (OC) curves, based on the component tests, and illustrate their use in designing or evaluating an overall test program. By specifying OC values (akin to producer's and consumer's risks), optimum, system-oriented component-test plans can be derived. These ideas are illustrated for a series system, and for a simple series-parallel system, with binomial data. C1 UNIV PITTSBURGH,DEPT IND ENGN,PITTSBURGH,PA 15261. RP EASTERLING, RG (reprint author), SANDIA NATL LABS,DIV STAT COMP & HUMAN FACTORS,ALBUQUERQUE,NM 87185, USA. NR 14 TC 18 Z9 18 U1 0 U2 0 PU AMER STATIST ASSN PI ALEXANDRIA PA 1429 DUKE ST, ALEXANDRIA, VA 22314 SN 0040-1706 J9 TECHNOMETRICS JI Technometrics PD AUG PY 1991 VL 33 IS 3 BP 287 EP 298 DI 10.2307/1268781 PG 12 WC Statistics & Probability SC Mathematics GA FY482 UT WOS:A1991FY48200003 ER PT J AU BOIS, FY WOODRUFF, TJ SPEAR, RC AF BOIS, FY WOODRUFF, TJ SPEAR, RC TI COMPARISON OF 3 PHYSIOLOGICALLY BASED PHARMACOKINETIC MODELS OF BENZENE DISPOSITION SO TOXICOLOGY AND APPLIED PHARMACOLOGY LA English DT Article ID RISK ASSESSMENT; B6C3F1 MICE; RATS; METABOLISM; EXPOSURE; INHALATION; PARAMETERS; SIMULATION; HUMANS C1 UNIV CALIF BERKELEY LAWRENCE BERKELEY LAB,BERKELEY,CA 94720. RP BOIS, FY (reprint author), UNIV CALIF BERKELEY,SCH PUBL HLTH,BERKELEY,CA 94720, USA. RI Bois, Frederic/E-9241-2012 OI Bois, Frederic/0000-0002-4154-0391 FU NIEHS NIH HHS [P42 ES04705] NR 30 TC 46 Z9 46 U1 1 U2 3 PU ACADEMIC PRESS INC JNL-COMP SUBSCRIPTIONS PI SAN DIEGO PA 525 B ST, STE 1900, SAN DIEGO, CA 92101-4495 SN 0041-008X J9 TOXICOL APPL PHARM JI Toxicol. Appl. Pharmacol. PD AUG PY 1991 VL 110 IS 1 BP 79 EP 88 DI 10.1016/0041-008X(91)90291-L PG 10 WC Pharmacology & Pharmacy; Toxicology SC Pharmacology & Pharmacy; Toxicology GA GB473 UT WOS:A1991GB47300008 PM 1871774 ER PT J AU PENNYCOOK, SJ JESSON, DE AF PENNYCOOK, SJ JESSON, DE TI HIGH-RESOLUTION Z-CONTRAST IMAGING OF CRYSTALS SO ULTRAMICROSCOPY LA English DT Article; Proceedings Paper CT 3RD CONF ON FRONTIERS OF ELECTRON MICROSCOPY IN MATERIALS SCIENCE CY MAY 20-24, 1990 CL OAK BROOK, IL SP LAWRENCE LIVERMORE NATL LAB, CHEM & MAT SCI DEPT, ARGONNE NATL LAB, DIV MAT SCI, AMER INST MECH ENGINEERS, MIDWEST SOC ELECTRON MICROSCOPISTS ID ENERGY ELECTRON-DIFFRACTION; FIELD STEM IMAGES; BLOCH WAVES; SCANNING MICROSCOPE; DIFFUSE-SCATTERING; SILICON; FILMS; ORDER; PARAMETERS; INTERFACE AB The use of a high-angle annular detector in a scanning transmission electron microscope is shown to provide incoherent images of crystalline materials with strong compositional sensitivity. How this occurs, even in the presence of strong dynamical diffraction of the low-angle beams, becomes very clear in a Bloch wave description of the imaging, which shows that only tightly bound s-type Bloch states contribute significantly to the image. Interference effects are therefore precluded and the image can be described as a convolution. There are no contrast reversals with thickness or defocus and no Fresnel fringe effects at interfaces. Each atomic column contributes to the image independently of its neighbors until the s-states themselves overlap. With an optimum imaging probe the nature of the convolution can be visualized intuitively to a scale well below the resolution limit. To first order, therefore, each object has only one possible image, and since the same probe is used for all objects, an unknown structure can be interpreted directly. These ideas will be illustrated with images from semiconductors, superconductors, and alloys. RP PENNYCOOK, SJ (reprint author), OAK RIDGE NATL LAB,DIV SOLID STATE,OAK RIDGE,TN 37831, USA. OI Jesson, David/0000-0003-0897-1445 NR 84 TC 500 Z9 505 U1 8 U2 93 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0304-3991 J9 ULTRAMICROSCOPY JI Ultramicroscopy PD AUG PY 1991 VL 37 IS 1-4 BP 14 EP 38 DI 10.1016/0304-3991(91)90004-P PG 25 WC Microscopy SC Microscopy GA GK412 UT WOS:A1991GK41200003 ER PT J AU WANG, ZL BENTLEY, J AF WANG, ZL BENTLEY, J TI Z-CONTRAST IMAGING OF BULK CRYSTAL-SURFACES IN SCANNING REFLECTION ELECTRON-MICROSCOPY SO ULTRAMICROSCOPY LA English DT Article; Proceedings Paper CT 3RD CONF ON FRONTIERS OF ELECTRON MICROSCOPY IN MATERIALS SCIENCE CY MAY 20-24, 1990 CL OAK BROOK, IL SP LAWRENCE LIVERMORE NATL LAB, CHEM & MAT SCI DEPT, ARGONNE NATL LAB, DIV MAT SCI, AMER INST MECH ENGINEERS, MIDWEST SOC ELECTRON MICROSCOPISTS ID RESOLUTION; IMAGES AB Following the recent development of high-angle annular dark field Z-contrast imaging in scanning transmission electron microscopy (STEM), a technique for obtaining high-resolution surface lattice images with contrast sensitive to atomic number is investigated theoretically in the geometry of scanning reflection electron microscopy (SREM) with a high-angle annular detector. The contrast in this type of image is determined mainly by the scattering power of each atomic site. As in the STEM case, the resolution in this Z-contrast SREM mode is approximately defined by the size of the electron probe if it is larger than the width of the atonmic potential well. Calculations for a Ge/Si interface bulk cross section with and without reconstruction and adsorption are presented, including the contribution from thermal diffuse scattering. C1 UNIV TENNESSEE,DEPT MAT SCI & ENGN,KNOXVILLE,TN 37996. RP WANG, ZL (reprint author), OAK RIDGE NATL LAB,DIV MET & CERAM,POB 2008,OAK RIDGE,TN 37831, USA. RI Wang, Zhong Lin/E-2176-2011 OI Wang, Zhong Lin/0000-0002-5530-0380 NR 20 TC 5 Z9 5 U1 0 U2 0 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0304-3991 J9 ULTRAMICROSCOPY JI Ultramicroscopy PD AUG PY 1991 VL 37 IS 1-4 BP 39 EP 49 DI 10.1016/0304-3991(91)90005-Q PG 11 WC Microscopy SC Microscopy GA GK412 UT WOS:A1991GK41200004 ER PT J AU WANG, ZL BENTLEY, J AF WANG, ZL BENTLEY, J TI IMAGING AND SPECTROSCOPY OF ALPHA-AL2O3, DIAMOND, NI AND FE BULK CRYSTAL-SURFACES SO ULTRAMICROSCOPY LA English DT Article; Proceedings Paper CT 3RD CONF ON FRONTIERS OF ELECTRON MICROSCOPY IN MATERIALS SCIENCE CY MAY 20-24, 1990 CL OAK BROOK, IL SP LAWRENCE LIVERMORE NATL LAB, CHEM & MAT SCI DEPT, ARGONNE NATL LAB, DIV MAT SCI, AMER INST MECH ENGINEERS, MIDWEST SOC ELECTRON MICROSCOPISTS ID REFLECTION ELECTRON-MICROSCOPY; ENERGY-LOSS SPECTROSCOPY; 111 SILICON SURFACES; ATOMIC TERMINATIONS; FCC METALS; REELS; REM; RHEED AB Reflection electron microscopy (REM) and reflection electron energy-loss spectroscopy (REELS) have been used to study the structures of several bulk crystal surfaces of practical importance. Different radiation damage responses to the electron beam were found on both the alpha-Al2O3 (011BAR) and (012BAR) surfaces for regions with different atomic terminations. The damage causes desorption of oxygen ions from surface domains initially terminated with oxygen. Surface microanalysis by REELS is complicated by the channeling of electrons along the different atomic planes parallel to the surface under resonance conditions, but the effect was used to measure the density of adsorbed oxygen atoms. The variation in contrast of alumina (012BAR) with changes of diffraction conditions cannot be interpreted based on the traditional criterion for surface resonance; a new criterion is introduced for identifying true resonance. Synthetic diamond grains in the as-received condition were imaged with REM and surface steps were observed. Nickel (110) surfaces were found to have a terraced structure with offset step modulations. REELS easily detected the Ni M and Ni L edges but failed to detect any light elements expected to be adsorbed at the surfaces. It was difficult to image iron surfaces due to strong magnetic deflection, but reasonable Fe L edge REELS spectra were obtained. C1 UNIV TENNESSEE,DEPT MAT SCI & ENGN,KNOXVILLE,TN 37996. RP WANG, ZL (reprint author), OAK RIDGE NATL LAB,DIV MET & CERAM,POB 2008,OAK RIDGE,TN 37831, USA. RI Wang, Zhong Lin/E-2176-2011 OI Wang, Zhong Lin/0000-0002-5530-0380 NR 34 TC 10 Z9 10 U1 1 U2 5 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0304-3991 J9 ULTRAMICROSCOPY JI Ultramicroscopy PD AUG PY 1991 VL 37 IS 1-4 BP 103 EP 115 DI 10.1016/0304-3991(91)90010-4 PG 13 WC Microscopy SC Microscopy GA GK412 UT WOS:A1991GK41200009 ER PT J AU MERKLE, KL AF MERKLE, KL TI HIGH-RESOLUTION ELECTRON-MICROSCOPY OF INTERFACES IN FCC MATERIALS SO ULTRAMICROSCOPY LA English DT Article; Proceedings Paper CT 3RD CONF ON FRONTIERS OF ELECTRON MICROSCOPY IN MATERIALS SCIENCE CY MAY 20-24, 1990 CL OAK BROOK, IL SP LAWRENCE LIVERMORE NATL LAB, CHEM & MAT SCI DEPT, ARGONNE NATL LAB, DIV MAT SCI, AMER INST MECH ENGINEERS, MIDWEST SOC ELECTRON MICROSCOPISTS ID TILT GRAIN-BOUNDARIES; STRUCTURE-ENERGY CORRELATION; ATOMIC-STRUCTURE; COMPUTER-SIMULATION; SYMMETRICAL TILT; NICKEL-OXIDE; METALS; TWIST; PLANES; NIO AB Modern high-resolution electron microscopy (HREM) instruments, which are capable of a point-to-point resolution of better than 0.2 nm, have allowed atomic-scale observations of a variety of intemal interfaces. The application of the HREM technique to fcc model systems for the purpose of addressing a number of interface issues will be examined in this paper. Atom.ic structure observations for heterophase interfaces of metal/metal and metal/metal-oxide systems as well as HREM studies of grain boundaries in NiO and Au will be discussed with emphasis on generic structural features and the role of the interface plane. Comparisons between observed interface structures and atomistic computer modeling results have shown agreements for some interfaces, and certain differences in others. A number of structural features are common to both metal and oxide grain boundafies, as well as certain heterophase boundaries. Of particular importance in close-packed solids appears to be the tendency to preserve, as much as possible, local atomic coordination, giving rise to atomically well-matched regions that altemate along the interface with regions of misfit. It is commonly observed that heterophase interfaces are preferentially formed on dense-packed planes. Low-index planes are also frequently observed in asymmetric grain boundaries. In addition to the observation of misfit dislocations in heterophase boundaries, misfit-dislocation-like defects have also been found in asymmetric, incommensurate grain boundaries. The tcndency for maintaining coherence between dense-packed planes across the interface has resulted in the formation of novel three-dimensional grain boundary structures. HREM observations have brought new insights into the coffelations between macroscopic geometry, interfacial energy, and microscopic atomic relaxations. RP MERKLE, KL (reprint author), ARGONNE NATL LAB,DIV MAT SCI,ARGONNE,IL 60439, USA. NR 82 TC 67 Z9 69 U1 1 U2 10 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0304-3991 J9 ULTRAMICROSCOPY JI Ultramicroscopy PD AUG PY 1991 VL 37 IS 1-4 BP 130 EP 152 DI 10.1016/0304-3991(91)90013-V PG 23 WC Microscopy SC Microscopy GA GK412 UT WOS:A1991GK41200012 ER PT J AU ALLARD, LF DATYE, AK NOLAN, TA MAHAN, SL PAINE, RT AF ALLARD, LF DATYE, AK NOLAN, TA MAHAN, SL PAINE, RT TI HIGH-RESOLUTION ELECTRON-MICROSCOPY OF BN ON MGO - A MODEL CERAMIC CERAMIC INTERFACE SO ULTRAMICROSCOPY LA English DT Article; Proceedings Paper CT 3RD CONF ON FRONTIERS OF ELECTRON MICROSCOPY IN MATERIALS SCIENCE CY MAY 20-24, 1990 CL OAK BROOK, IL SP LAWRENCE LIVERMORE NATL LAB, CHEM & MAT SCI DEPT, ARGONNE NATL LAB, DIV MAT SCI, AMER INST MECH ENGINEERS, MIDWEST SOC ELECTRON MICROSCOPISTS ID CARBON; GRAPHITIZATION; ALIGNMENT; CRYSTAL AB Studies of ceramic-ceramic interfaces by high-resolution electron microscopy have been facilitated by a novel approach to specimen preparation. Coatings of a variety of cerarmics can be applied by various techniques to the surfaces of nonporous cerarmic particles of simple geometric shape, and the resulting interfaces can be examined directly without the necessity for ion-beam milling. For example, coatings of boron nitride prepared from a polymeric precursor have been applied to the surfaces of crystalline oxides such as MgO, Al2O3 and TiO2. The initially amorphous BN wets the crystalline oxide surfaces and crystallizes to form tough, adherent coatings of hexagonal BN. On crystalline specimens, the hexagonal BN grows with the {002} layer planes locally parallel to the oxide surface in each instance, permitting interfaces between the {002} BN layers and particular oxide planes to be studied. The most successful results have been obtained to date from studies of BN on MgO{110} surfaces. The work described here details the characterization of the atomic structure of these model BN/MgO interfaces by methods of high-resolution electron microscopy. C1 UNIV NEW MEXICO,CTR MICROENGN CERAM,ALBUQUERQUE,NM 87131. RP ALLARD, LF (reprint author), OAK RIDGE NATL LAB,HIGH TEMP MAT LAB,OAK RIDGE,TN, USA. NR 38 TC 4 Z9 4 U1 0 U2 2 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0304-3991 J9 ULTRAMICROSCOPY JI Ultramicroscopy PD AUG PY 1991 VL 37 IS 1-4 BP 153 EP 168 DI 10.1016/0304-3991(91)90014-W PG 16 WC Microscopy SC Microscopy GA GK412 UT WOS:A1991GK41200013 ER PT J AU JOY, DC AF JOY, DC TI THE THEORY AND PRACTICE OF HIGH-RESOLUTION SCANNING ELECTRON-MICROSCOPY SO ULTRAMICROSCOPY LA English DT Article; Proceedings Paper CT 3RD CONF ON FRONTIERS OF ELECTRON MICROSCOPY IN MATERIALS SCIENCE CY MAY 20-24, 1990 CL OAK BROOK, IL SP LAWRENCE LIVERMORE NATL LAB, CHEM & MAT SCI DEPT, ARGONNE NATL LAB, DIV MAT SCI, AMER INST MECH ENGINEERS, MIDWEST SOC ELECTRON MICROSCOPISTS ID IMAGE-CONTRAST; SEM; EXCITATIONS; SURFACE AB Recent advances in instrumentation have produced the first commercial examples of what can justifiably be called high-resolution scanning electron microscopes. The key components of such instruments are a cold field emission gun, a small-gap immersion probe-forming lens, and a clean dry-pumped vacuum. The performance of these microscopes is characterized by several major features including a spatial resolution, in secondary electron mode on sotid specimens, which can exceed 1 nm on a routine basis; an incident probe current density of the order of 10(6) A/cm2; and the ability to maintain these levels of performance over an accelerating voltage range of from 1 to 30 keV. This combination of high resolution, high probe current, low contamination and flexible electron-optical conditions provides many new opportunities for the application of the SEM to materials science, physics, and the life sciences. C1 OAK RIDGE NATL LAB,DIV MET & CERAM,OAK RIDGE,TN 37831. UNIV TENNESSEE,DEPT ZOOL,KNOXVILLE,TN 37996. RP JOY, DC (reprint author), UNIV TENNESSEE,EM FACIL,KNOXVILLE,TN 37996, USA. NR 27 TC 22 Z9 22 U1 3 U2 23 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0304-3991 J9 ULTRAMICROSCOPY JI Ultramicroscopy PD AUG PY 1991 VL 37 IS 1-4 BP 216 EP 233 DI 10.1016/0304-3991(91)90020-7 PG 18 WC Microscopy SC Microscopy GA GK412 UT WOS:A1991GK41200019 ER PT J AU MORE, KL KOESTER, DA DAVIS, RF AF MORE, KL KOESTER, DA DAVIS, RF TI MICROSTRUCTURAL CHARACTERIZATION OF A CREEP-DEFORMED SIC WHISKER-REINFORCED SI3N4 SO ULTRAMICROSCOPY LA English DT Article; Proceedings Paper CT 3RD CONF ON FRONTIERS OF ELECTRON MICROSCOPY IN MATERIALS SCIENCE CY MAY 20-24, 1990 CL OAK BROOK, IL SP LAWRENCE LIVERMORE NATL LAB, CHEM & MAT SCI DEPT, ARGONNE NATL LAB, DIV MAT SCI, AMER INST MECH ENGINEERS, MIDWEST SOC ELECTRON MICROSCOPISTS ID PRESSED SILICON-NITRIDE; HIGH-TEMPERATURE STRENGTH; BOUNDARY-PHASE CRYSTALLIZATION; CERAMIC-MATRIX COMPOSITES; INTERGRANULAR PHASE; ELEMENTAL COMPOSITION; TOUGHENING BEHAVIOR; COMPRESSIVE CREEP; YSIALON GLASS; Y2O3 AB Constant compressive stress-creep experiments have been conducted in the temperature and stress ranges of 1470-1720 K and 50-350 MPa, respectively, on a 30 vol% SiC whisker-reinforced Si3N4 composite containing sintering aids of 1.5 wt% Al2O3 and 6.0 wt% Y2O3. This work focuses on two independent creep expefiments conducted at 1470 and 1620 K, both in the stress range 50-350 MPa. At 1620 K, the stress exponent, n, exhibited a bihnear behavior with n < 1 in the low-stress regime and n > 1 in the high-stress regime. This behavior was not observed at 1470 K. Various electron microscopy and X-ray diffraction techniques have been used to completely characterize the microstructure of the as-received, annealed, and crept materials. Transmission electron microscopy observations on samples taken before and after the change in n at 1620 K were compared to observations on material crept at 1470 K to clarify the microstructural phenomena controlling the break in the creep curve. Interfaces between Si3N4 grains and the whisker reinforcement were examined using high-resolution electron microscopy. The relationships between observed microstructural changes and high-temperature mechanical properties are presented. C1 N CAROLINA STATE UNIV,DEPT MAT SCI & ENGN,RALEIGH,NC 27695. RP MORE, KL (reprint author), OAK RIDGE NATL LAB,HIGH TEMP MAT LAB,OAK RIDGE,TN 37831, USA. RI Davis, Robert/A-9376-2011; More, Karren/A-8097-2016 OI Davis, Robert/0000-0002-4437-0885; More, Karren/0000-0001-5223-9097 NR 72 TC 5 Z9 5 U1 0 U2 0 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0304-3991 J9 ULTRAMICROSCOPY JI Ultramicroscopy PD AUG PY 1991 VL 37 IS 1-4 BP 263 EP 278 DI 10.1016/0304-3991(91)90024-Z PG 16 WC Microscopy SC Microscopy GA GK412 UT WOS:A1991GK41200023 ER PT J AU SMITH, DA ALLEN, CW AF SMITH, DA ALLEN, CW TI MORPHOLOGY AND MOTION OF THE INTERFACE BETWEEN AMORPHOUS AND CRYSTALLINE COBALT DISILICIDE SO ULTRAMICROSCOPY LA English DT Article; Proceedings Paper CT 3RD CONF ON FRONTIERS OF ELECTRON MICROSCOPY IN MATERIALS SCIENCE CY MAY 20-24, 1990 CL OAK BROOK, IL SP LAWRENCE LIVERMORE NATL LAB, CHEM & MAT SCI DEPT, ARGONNE NATL LAB, DIV MAT SCI, AMER INST MECH ENGINEERS, MIDWEST SOC ELECTRON MICROSCOPISTS ID SI; MICROSTRUCTURE; FILMS; TA AB Amorphous CoSi2 films were prepared by codeposition onto electron-transparent silicon nitride window substrates. The deposits were crystallized in situ without further processing, Two sets of experiments were done: thermal crystallization and thermal crystallization with additional ion-irradiation treatments before or during crystallization. The interface between the amorphous and crystaltine material is rough on the scale of 20 nm with some tendency to facet. Irradiation by 1.5 MeV Kr ions stimulates both nucleation and growth at room temperature. Prior ion-irradiation followed by heating in the absence of an ion-flux also enhances the nucleation and growth kinetics relative to a purely thermal treatment. C1 ARGONNE NATL LAB,DIV MAT SCI,ARGONNE,IL 60439. RP SMITH, DA (reprint author), IBM CORP,THOMAS J WATSON RES CTR,DIV RES,POB 218,YORKTOWN HTS,NY 10598, USA. NR 17 TC 4 Z9 4 U1 0 U2 0 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0304-3991 J9 ULTRAMICROSCOPY JI Ultramicroscopy PD AUG PY 1991 VL 37 IS 1-4 BP 279 EP 285 DI 10.1016/0304-3991(91)90025-2 PG 7 WC Microscopy SC Microscopy GA GK412 UT WOS:A1991GK41200024 ER PT J AU ERDEMIR, A CHENG, CC AF ERDEMIR, A CHENG, CC TI CROSS-SECTIONAL TRANSMISSION ELECTRON-MICROSCOPY STUDY OF PHASE-TRANSFORMATIONS AT TIN FILM STEEL SUBSTRATE INTERFACES SO ULTRAMICROSCOPY LA English DT Article; Proceedings Paper CT 3RD CONF ON FRONTIERS OF ELECTRON MICROSCOPY IN MATERIALS SCIENCE CY MAY 20-24, 1990 CL OAK BROOK, IL SP LAWRENCE LIVERMORE NATL LAB, CHEM & MAT SCI DEPT, ARGONNE NATL LAB, DIV MAT SCI, AMER INST MECH ENGINEERS, MIDWEST SOC ELECTRON MICROSCOPISTS ID HARD COATINGS; ADHESION AB Cross-sectional transmission electron microscopy (XTEM) was used to investigate the extent of solid-state phase transformations near the interfaces of TiN films and AISI M50, 316L, and 440C steel substrates. An ion-plating system was used to deposit the TiN films with and without an initial Ti underlayer on the substrates, whose carbon concentrations ranged from 0.02 to 1 wt%. All films were produced at 500-degrees-C. XTEM, together with electron-energy-loss spectroscopy (EELS) and convergent-beam electron diffraction, of the interfaces indicated that (a) the ion-plated Ti underlayers transform into a TiC phase on high-carbon steel substrates and into a delta'-TiN phase on low-carbon steel substrates, and (b) without a Ti underlayer, TiN grows as the dominant phase on 440-degrees-C steel substrates. C1 INLAND STEEL CORP,E CHICAGO,IN 46213. RP ERDEMIR, A (reprint author), ARGONNE NATL LAB,DIV MAT & COMPONENTS TECHNOL,ARGONNE,IL 60439, USA. NR 16 TC 1 Z9 1 U1 0 U2 0 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0304-3991 J9 ULTRAMICROSCOPY JI Ultramicroscopy PD AUG PY 1991 VL 37 IS 1-4 BP 286 EP 293 DI 10.1016/0304-3991(91)90026-3 PG 8 WC Microscopy SC Microscopy GA GK412 UT WOS:A1991GK41200025 ER PT J AU GAO, Y MERKLE, KL BAI, G CHANG, HLM LAM, DJ AF GAO, Y MERKLE, KL BAI, G CHANG, HLM LAM, DJ TI [001] TILT GRAIN-BOUNDARIES IN YBA2CU3O7-X THIN-FILMS SO ULTRAMICROSCOPY LA English DT Article; Proceedings Paper CT 3RD CONF ON FRONTIERS OF ELECTRON MICROSCOPY IN MATERIALS SCIENCE CY MAY 20-24, 1990 CL OAK BROOK, IL SP LAWRENCE LIVERMORE NATL LAB, CHEM & MAT SCI DEPT, ARGONNE NATL LAB, DIV MAT SCI, AMER INST MECH ENGINEERS, MIDWEST SOC ELECTRON MICROSCOPISTS ID TRANSPORT CRITICAL CURRENT; SUPERCONDUCTORS; NIO AB Grain boundaries in YBa2Cu3O7-x superconductor thin films grown on (001) MgO by metal-organic chemical vapor deposition (MOCVD) have been characterized using transfftission electron microscopy (TEM) and high-resolution electron microscopy (HREM). It was found that the YBa2Cu3O7-x thin films were highly textured with the c axes, or [001] orientation, nearly parallel between grains and perpendicular to the MgO substrate. A majority of the grain boundaries are low-angle boundaries with a tilt angle, theta, less than 15-degrees. The low-angle boundaries appear to be strongly faceted on an atomic scale in such a way that the boundary planes tend to be parallel to the (100), (010), or (110) lattice planes in one of the adjacent grains. Almost all of the lattice planes, except for a number of distorted regions along the boundaries, are continuous across the boundaries from one grain to another, accommodating the misorientation with a slight bending of the lattice planes. The small-angle boundaries are shown to consist of affays of dislocations. A domain structure formed by the interchange of a and b axes has been observed in large grains. The domain boundaries are strongly faceted with the (100) and (010) lattice planes parallel to the boundaries. These observations on the atomic structure of boundaries are used to discuss the effect of grain boundaries on superconductor properties in YBa2Cu3O7-x thin films. C1 ARGONNE NATL LAB,SCI & TECHNOL CTR SUPERCONDUCT,ARGONNE,IL 60439. RP GAO, Y (reprint author), ARGONNE NATL LAB,DIV MAT SCI,ARGONNE,IL 60439, USA. NR 16 TC 21 Z9 22 U1 0 U2 2 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0304-3991 J9 ULTRAMICROSCOPY JI Ultramicroscopy PD AUG PY 1991 VL 37 IS 1-4 BP 326 EP 340 DI 10.1016/0304-3991(91)90030-A PG 15 WC Microscopy SC Microscopy GA GK412 UT WOS:A1991GK41200029 ER PT J AU ZHU, YM SUENAGA, M MOODENBAUGH, AR AF ZHU, YM SUENAGA, M MOODENBAUGH, AR TI OXYGEN, DIFFUSE-SCATTERING, AND TWEED STRUCTURE IN THE YBA2CU3O7-DELTA SYSTEM SO ULTRAMICROSCOPY LA English DT Article; Proceedings Paper CT 3RD CONF ON FRONTIERS OF ELECTRON MICROSCOPY IN MATERIALS SCIENCE CY MAY 20-24, 1990 CL OAK BROOK, IL SP LAWRENCE LIVERMORE NATL LAB, CHEM & MAT SCI DEPT, ARGONNE NATL LAB, DIV MAT SCI, AMER INST MECH ENGINEERS, MIDWEST SOC ELECTRON MICROSCOPISTS ID SUBSTITUTED YBA2CU3O7-DELTA; CU; YBA2(CU1-XFEX)3O7-DELTA; YBA2(CU1-XCOX)3O7-DELTA; MICROSTRUCTURES; DIFFRACTION; ALLOYS; ORDER; PHASE; NI AB Microstructure and diffuse scattering of electron diffraction in YBa2(Cu1-xMx)3O7-delta (M = Fe, Co, Al, Ga, Zn and Ni, 0 less-than-or-equal-to x less-than-to-equal-to 0.33) were studied. It was found that the substitution for Cu by 3-valent Fe, Co and Al at a level x greater-than-or-equal-to 0.03 causes a structural transition from twin to tweed. For 0.03 less-than-or-equal-to x less-than-or-equal-to 0.06, the geometry of the reciprocal spot associated with the tweed structure has a cross-platelet shape extended in 2 equivalent directions, which coffesponds to the displacive modulation in real space. For x greater-than-or-equal-to 0.10, the observed diffuse satelhtes and short-square-pipe intensity suggest the existence of a three-dimensional short-range ordering in these materials. Oxygen-reduction and reoxidization experiments indicate that development of tweed depends on the oxygen distribution. We believe that the configuration of oxygen in the Cu(1) layer is responsible for the formation of tweed structure in YBa2Cu3O7-delta system. RP ZHU, YM (reprint author), BROOKHAVEN NATL LAB,DIV MAT SCI,UPTON,NY 11973, USA. OI Moodenbaugh, Arnold/0000-0002-3415-6762 NR 32 TC 23 Z9 23 U1 2 U2 2 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0304-3991 J9 ULTRAMICROSCOPY JI Ultramicroscopy PD AUG PY 1991 VL 37 IS 1-4 BP 341 EP 350 DI 10.1016/0304-3991(91)90031-Z PG 10 WC Microscopy SC Microscopy GA GK412 UT WOS:A1991GK41200030 ER PT J AU THANGARAJ, N WESTMACOTT, KH DAHMEN, U AF THANGARAJ, N WESTMACOTT, KH DAHMEN, U TI HVEM STUDIES OF THE SINTERING OF MGO NANOCRYSTALS PREPARED BY MG(OH)2 DECOMPOSITION SO ULTRAMICROSCOPY LA English DT Article; Proceedings Paper CT 3RD CONF ON FRONTIERS OF ELECTRON MICROSCOPY IN MATERIALS SCIENCE CY MAY 20-24, 1990 CL OAK BROOK, IL SP LAWRENCE LIVERMORE NATL LAB, CHEM & MAT SCI DEPT, ARGONNE NATL LAB, DIV MAT SCI, AMER INST MECH ENGINEERS, MIDWEST SOC ELECTRON MICROSCOPISTS ID SIZE; TRANSFORMATIONS; DEHYDRATION; CALCINATION; MORPHOLOGY AB Hot-stage high-voltage electron microscopy (HVEM) combined with high-resolution electron microscopy (HREM) has been employed to study the microstructural evolution during in-situ decomposition of thin Mg(OH)2 flakes and during early-stage sintering of the resultant nanocomposite. The decomposition reaction is known to be pseudomorphic and topotactic, resulting in a regular composite of highly aligned nearly cubic MgO nanocrystals interspersed with a roughly equal volume of pores. This structure was characterized by selected-area and optical-diffraction techniqucs as well as by HREM, depending on its microstructural scale. Immediately after decomposition and in the early stages of sintering the fine-scale and regular, nearly periodic nature of the microstructure gave rise to diffuse small-angle diffraction rings that could be used as a measurc of coarsening during in-situ heating in the temperature range 350-900-degrees-C. Consistent results were obtained from electron diffraction, optical diffraction and Foufier transforms of digitized images. These measurements were complementary to direct imaging by HREM or conventional imaging techniques. RP THANGARAJ, N (reprint author), UNIV CALIF BERKELEY LAWRENCE BERKELEY LAB,NATL CTR ELECTRON MICROSCOPY,BERKELEY,CA 94720, USA. NR 26 TC 13 Z9 14 U1 0 U2 7 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0304-3991 J9 ULTRAMICROSCOPY JI Ultramicroscopy PD AUG PY 1991 VL 37 IS 1-4 BP 362 EP 374 DI 10.1016/0304-3991(91)90033-3 PG 13 WC Microscopy SC Microscopy GA GK412 UT WOS:A1991GK41200032 ER PT J AU BRADLEY, SA KING, WE ALLEN, CW AF BRADLEY, SA KING, WE ALLEN, CW TI FRONTIERS OF ELECTRON-MICROSCOPY IN MATERIALS SCIENCE - PROCEEDINGS OF THE 3RD CONFERENCE ON FRONTIERS OF ELECTRON-MICROSCOPY IN MATERIALS SCIENCE OAK-BROOK, IL, USA, 20-24 MAY 1990 - FOREWORD SO ULTRAMICROSCOPY LA English DT Editorial Material C1 UNIV CALIF LAWRENCE LIVERMORE NATL LAB,LIVERMORE,CA 94550. ARGONNE NATL LAB,ARGONNE,IL 60439. RP BRADLEY, SA (reprint author), UOP RES CTR,DES PLAINES,IL, USA. 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 0304-3991 J9 ULTRAMICROSCOPY JI Ultramicroscopy PD AUG PY 1991 VL 37 IS 1-4 BP R7 EP R7 PG 1 WC Microscopy SC Microscopy GA GK412 UT WOS:A1991GK41200001 ER PT J AU TOKUNAGA, TK LIPTON, DS BENSON, SM YEE, AW OLDFATHER, JM DUCKART, EC JOHANNIS, PW HALVORSEN, KE AF TOKUNAGA, TK LIPTON, DS BENSON, SM YEE, AW OLDFATHER, JM DUCKART, EC JOHANNIS, PW HALVORSEN, KE TI SOIL SELENIUM FRACTIONATION, DEPTH PROFILES AND TIME TRENDS IN A VEGETATED SITE AT KESTERSON RESERVOIR SO WATER AIR AND SOIL POLLUTION LA English DT Article; Proceedings Paper CT INTERNATIONAL CONF ON METALS IN SOILS, WATERS, PLANTS AND ANIMALS CY APR 30-MAY 03, 1990 CL ORLANDO, FL SP US DOE, SAVANNAH RIV OPERAT OFF ID PARTIAL DISSOLUTION; CALIFORNIA; SPECIATION AB Kesterson Reservoir, in the San Joaquin Valley of California, was used for disposal of saline, seleniferous agricultural drain waters during the years 1981 - 1986. The combined effects of infrequent drain water application, reduction and oxidation of Se, and evapotranspirative removal of soil water within the upper 1 m of the soil profiles appear to provide explanations for distribution patterns of Se in soils of upland sites. From 1987 to 1990, an approximate doubling in average soil solution Se concentrations was observed. It is shown that currently only relatively insignificant quantities of Se have been transported into the Pond 11 soils from the shallow water table. Sequential extraction of these upland soils indicated that substantial inventories of Se were associated with soluble, adsorbed, carbonate, and soil organic matter fractions, while Se retained within refractory inorganic fractions were minor. The mobilization of Se from these potentially labile pools may account for the observed increases in soil solution concentrations of Se following the draining of Kesterson Reservoir. RP TOKUNAGA, TK (reprint author), UNIV CALIF BERKELEY,LAWRENCE BERKELEY LAB,DIV EARTH SCI,BERKELEY,CA 94720, USA. RI Schneider, Larissa/C-9863-2012; Tokunaga, Tetsu/H-2790-2014 OI Tokunaga, Tetsu/0000-0003-0861-6128 NR 19 TC 68 Z9 73 U1 1 U2 12 PU KLUWER ACADEMIC PUBL PI DORDRECHT PA SPUIBOULEVARD 50, PO BOX 17, 3300 AA DORDRECHT, NETHERLANDS SN 0049-6979 J9 WATER AIR SOIL POLL JI Water Air Soil Pollut. PD AUG PY 1991 VL 57-8 BP 31 EP 41 DI 10.1007/BF00282866 PG 11 WC Environmental Sciences; Meteorology & Atmospheric Sciences; Water Resources SC Environmental Sciences & Ecology; Meteorology & Atmospheric Sciences; Water Resources GA GP121 UT WOS:A1991GP12100005 ER PT J AU ORNES, WH SAJWAN, KS DOSSKEY, MG ADRIANO, DC AF ORNES, WH SAJWAN, KS DOSSKEY, MG ADRIANO, DC TI BIOACCUMULATION OF SELENIUM BY FLOATING AQUATIC PLANTS SO WATER AIR AND SOIL POLLUTION LA English DT Article; Proceedings Paper CT INTERNATIONAL CONF ON METALS IN SOILS, WATERS, PLANTS AND ANIMALS CY APR 30-MAY 03, 1990 CL ORLANDO, FL SP US DOE, SAVANNAH RIV OPERAT OFF ID SETTLING BASIN EFFLUENT; CHEMICAL-ELEMENTS; PRIMARY PRODUCERS; COAL ASH AB The degree to which floating aquatic plants concentrate Se in tissues was determined for four species grown in solutions containing various levels of Se. Results of this greenhouse study showed that all four plant species, Azolla caroliniana, Eichhornia crassipes, Salvinia rotundifolia, and Lemna mino absorbed Se quickly upon exposure to Se in water as concentrated as 2.5-mu-g Se mL-1, and attained maximum tissue concentrations within 1 to 2 weeks. Azolla absorbed Se to the highest tissue concentration (about 1000-mu-g Se g-1 dry matter) from the 2.5-mu-g Se mL-1 solution, followed by Salvinia (700-mu-g-1), Lemna (500-mu-g Se g-1), and Eichhornia (300-mu-g Se g-1). Plant growth appeared unaffected by solution Se concentrations lower than about 1.25-mu-g mL-1. These results indicate potential for rapid Se movement from water into aquatic food chains, and for use of aquatic plants for Se removal in wastewater treatment systems. C1 SAVANNAH RIVER ECOL LAB,AIKEN,SC 29802. RP ORNES, WH (reprint author), UNIV S CAROLINA,DEPT BIOL,AIKEN,SC 29801, USA. NR 15 TC 21 Z9 21 U1 0 U2 4 PU KLUWER ACADEMIC PUBL PI DORDRECHT PA SPUIBOULEVARD 50, PO BOX 17, 3300 AA DORDRECHT, NETHERLANDS SN 0049-6979 J9 WATER AIR SOIL POLL JI Water Air Soil Pollut. PD AUG PY 1991 VL 57-8 BP 53 EP 57 DI 10.1007/BF00282868 PG 5 WC Environmental Sciences; Meteorology & Atmospheric Sciences; Water Resources SC Environmental Sciences & Ecology; Meteorology & Atmospheric Sciences; Water Resources GA GP121 UT WOS:A1991GP12100007 ER PT J AU BHATTACHARYYA, MH AF BHATTACHARYYA, MH TI CADMIUM-INDUCED BONE LOSS - INCREASED SUSCEPTIBILITY IN FEMALES SO WATER AIR AND SOIL POLLUTION LA English DT Article; Proceedings Paper CT INTERNATIONAL CONF ON METALS IN SOILS, WATERS, PLANTS AND ANIMALS CY APR 30-MAY 03, 1990 CL ORLANDO, FL SP US DOE, SAVANNAH RIV OPERAT OFF ID NUTRIENT-SUFFICIENT DIET; GASTROINTESTINAL ABSORPTION; MICE; LACTATION; EXPOSURE; RATS; GESTATION; KIDNEY AB An overview is presented of studies on effects of Cd on (1) female mice during pregnancy and lactation and after ovariectomy and (2) bone organ/cell culture systems. The gastrointestinal absorption of Cd increased two- to threefold in mouse dams during pregnancy and lactation, with both the kidneys and duodenum of the dam showing striking increases in Cd deposition. Dietary Cd at 5 or 50-mu-g g-1 caused a dose-dependent decrease in femur Ca content in multiparous mouse dams but not in nonpregnant controls. In addition, dietary Cd at 50-mu-g g-1 significantly increased the loss of bone mineral that occurs normally in mice after removal of the ovaries. In cultures of fetal rat limb bones prelabeled with Ca-45, Cd at 10 nM (1 ng g-1) caused a release of 70% of the Ca-45, similar to the release caused by 10 nM parathyroid hormone. This level of Cd also caused a fivefold increase in the number of multinucleated osteoclast-like cells formed during in vitro incubation of progenitor-enriched mononuclear bone marrow cells. These results support the view that Cd exposure contributed to the pathogenesis of Itai-Itai disease among multiparous, postmenopausal women in Japan and provide evidence that Cd may act directly on bone. RP BHATTACHARYYA, MH (reprint author), ARGONNE NATL LAB,ARGONNE,IL 60439, USA. NR 18 TC 6 Z9 6 U1 0 U2 3 PU KLUWER ACADEMIC PUBL PI DORDRECHT PA SPUIBOULEVARD 50, PO BOX 17, 3300 AA DORDRECHT, NETHERLANDS SN 0049-6979 J9 WATER AIR SOIL POLL JI Water Air Soil Pollut. PD AUG PY 1991 VL 57-8 BP 665 EP 673 DI 10.1007/BF00282930 PG 9 WC Environmental Sciences; Meteorology & Atmospheric Sciences; Water Resources SC Environmental Sciences & Ecology; Meteorology & Atmospheric Sciences; Water Resources GA GP121 UT WOS:A1991GP12100069 ER PT J AU BRISBIN, IL NEWMAN, MC AF BRISBIN, IL NEWMAN, MC TI SIGMOID MODELS FOR THE UPTAKE, CONCENTRATION AND EFFECTS OF METALS IN CONSUMER ORGANISMS SO WATER AIR AND SOIL POLLUTION LA English DT Article; Proceedings Paper CT INTERNATIONAL CONF ON METALS IN SOILS, WATERS, PLANTS AND ANIMALS CY APR 30-MAY 03, 1990 CL ORLANDO, FL SP US DOE, SAVANNAH RIV OPERAT OFF ID GROWTH; PARAMETERS AB The uptake, concentration and effects of metals contamination in consumer organisms have been successfully described with the flexibly-shaped Richards sigmoid model. This model allows the simultaneous estimation of: (1) final asymptotic level of contaminant uptake or body growth, (2) the time required to approach asymptote, and (3) the particular path or trajectory taken by the function in approaching asymptote within the designated time. Analyses using the Richards model have shown that data for a variety of contaminants fail to conform to the shape of the classic monomolecular model and rather show an initial lag in the early uptake rate. In effects studies, the use of the Richards model to analyze body growth data from waterfowl exposed to dietary intake of Cd and other contaminants has shown that growth curve shape is more likely to change in response to contaminant intake than are either final asymptotic levels or the times required for asymptotes to be attained. Failure to consider such changes in growth curve shape could cause significant errors in the identification of growth responses to contaminant intake stress. RP BRISBIN, IL (reprint author), SAVANNAH RIVER ECOL LAB,PO DRAWER E,AIKEN,SC 29801, USA. NR 13 TC 0 Z9 0 U1 1 U2 1 PU KLUWER ACADEMIC PUBL PI DORDRECHT PA SPUIBOULEVARD 50, PO BOX 17, 3300 AA DORDRECHT, NETHERLANDS SN 0049-6979 J9 WATER AIR SOIL POLL JI Water Air Soil Pollut. PD AUG PY 1991 VL 57-8 BP 691 EP 696 PG 6 WC Environmental Sciences; Meteorology & Atmospheric Sciences; Water Resources SC Environmental Sciences & Ecology; Meteorology & Atmospheric Sciences; Water Resources GA GP121 UT WOS:A1991GP12100072 ER PT J AU CHEN, JS WEI, FS ZHENG, CJ WU, YY ADRIANO, DC AF CHEN, JS WEI, FS ZHENG, CJ WU, YY ADRIANO, DC TI BACKGROUND CONCENTRATIONS OF ELEMENTS IN SOILS OF CHINA SO WATER AIR AND SOIL POLLUTION LA English DT Article; Proceedings Paper CT INTERNATIONAL CONF ON METALS IN SOILS, WATERS, PLANTS AND ANIMALS CY APR 30-MAY 03, 1990 CL ORLANDO, FL SP US DOE, SAVANNAH RIV OPERAT OFF AB Mean concentrations of 62 elements, pH, organic matter and grain size have been computed for soil samples from 4,095 locations throughout mainland China. The compositions of geochemical data between mainland China and the conterminous United States and between Tibet and Alaska show a close correspondence for most elements determined. These geochemical data may reveal evidence of regional variations in the abundance of elements in soils. In general, the sequence for metal content in samples of soil orders was: Lithosol > Cold-highland soils > Inceptisol > Aridisol = Mollisol > Ultisol > Alfisol > Oxisol. This trend was apparently a result of climatic influence on soil genesis, with the Oxisols (high rainfall areas with highly weathered and highly leached soils) yielding the lowest elemental mean values. However, the highest mean values of most trace elements in the Lithosols were a result of its relatively high indigenous elemental contents as well as chemical properties of the bedrock from which the soils were formed. C1 CHINA NATL ENVIRONM MONITORING CTR,BEIJING 100012,PEOPLES R CHINA. CHINESE ACAD SCI,INST APPL ECOL,SHENYANG 110015,PEOPLES R CHINA. UNIV GEORGIA,SAVANNAH RIVER ECOL LAB,AIKEN,SC 29801. RP CHEN, JS (reprint author), BEIJING UNIV,DEPT GEOG,BEIJING 100871,PEOPLES R CHINA. NR 10 TC 71 Z9 83 U1 3 U2 25 PU KLUWER ACADEMIC PUBL PI DORDRECHT PA SPUIBOULEVARD 50, PO BOX 17, 3300 AA DORDRECHT, NETHERLANDS SN 0049-6979 J9 WATER AIR SOIL POLL JI Water Air Soil Pollut. PD AUG PY 1991 VL 57-8 BP 699 EP 712 DI 10.1007/BF00282934 PG 14 WC Environmental Sciences; Meteorology & Atmospheric Sciences; Water Resources SC Environmental Sciences & Ecology; Meteorology & Atmospheric Sciences; Water Resources GA GP121 UT WOS:A1991GP12100073 ER PT J AU WU, YY ZHOU, QX ADRIANO, DC AF WU, YY ZHOU, QX ADRIANO, DC TI INTERIM ENVIRONMENTAL GUIDELINES FOR CADMIUM AND MERCURY IN SOILS OF CHINA SO WATER AIR AND SOIL POLLUTION LA English DT Article; Proceedings Paper CT INTERNATIONAL CONF ON METALS IN SOILS, WATERS, PLANTS AND ANIMALS CY APR 30-MAY 03, 1990 CL ORLANDO, FL SP US DOE, SAVANNAH RIV OPERAT OFF ID SLUDGE AB A nationwide program is underway in China to establish environmental guidelines with respect to metal levels in soil. There are several factors considered in the formulation of these guidelines but the three major ones are: 1) the soil background content, 2) land use capability, and 3) ecological effect. The guidelines for Hg and Cd in soils of China are formulated based on soil samples collected from 26 provinces (n = 20,300) and by investigating the high background values in 4 mineralized areas. Based on land use capability, the environmental guidelines can be divided into four levels representing: 1) natural or pristine areas, 2) agricultural and pastoral areas, 3) forested areas, and 4) urban and waste disposal areas. The corresponding values are 0.10, 0.20, 0.50, 1.0 mg kg-1 for Hg; and 0.15, 0.30, 0.50, 1.0 (2.0 for calcareous paddy soil) mg kg-1 for Cd. C1 UNIV GEORGIA,SAVANNAH RIVER ECOL LAB,AIKEN,SC 29801. RP WU, YY (reprint author), ACAD SINICA,INST APPL ECOL,POB 417,SHENYANG,PEOPLES R CHINA. NR 12 TC 24 Z9 34 U1 2 U2 9 PU KLUWER ACADEMIC PUBL PI DORDRECHT PA SPUIBOULEVARD 50, PO BOX 17, 3300 AA DORDRECHT, NETHERLANDS SN 0049-6979 J9 WATER AIR SOIL POLL JI Water Air Soil Pollut. PD AUG PY 1991 VL 57-8 BP 733 EP 743 DI 10.1007/BF00282937 PG 11 WC Environmental Sciences; Meteorology & Atmospheric Sciences; Water Resources SC Environmental Sciences & Ecology; Meteorology & Atmospheric Sciences; Water Resources GA GP121 UT WOS:A1991GP12100076 ER PT J AU HE, X TAYLOR, RW SHUFORD, JW TADESSE, W ADRIANO, DC AF HE, X TAYLOR, RW SHUFORD, JW TADESSE, W ADRIANO, DC TI COMPARISON OF EXTRACTANTS FOR AVAILABLE SLUDGE-BORNE METALS - A RESIDUAL STUDY SO WATER AIR AND SOIL POLLUTION LA English DT Article; Proceedings Paper CT INTERNATIONAL CONF ON METALS IN SOILS, WATERS, PLANTS AND ANIMALS CY APR 30-MAY 03, 1990 CL ORLANDO, FL SP US DOE, SAVANNAH RIV OPERAT OFF ID SOIL TEST; SEWAGE-SLUDGE; AMENDED SOILS; ZINC; MANGANESE; COPPER; ACID; DTPA AB To study the availability of sludge-borne Zn, Cu, Cd, Ni and Pb over time, a field study was conducted. Anaerobically digested sewage sludge (dried on sandbeds) from Huntsville and Chicago were applied to a Decatur silty clay loam soil (clayey, kaolinitic, thermic, Rhodic Paleudult), pH 6.2, for 5 consecutive yr. The sludges were applied at rates of 0, 20 (annual application for 5 yr) and 100 mt ha-1 (single application). Corn (Zea mays L.) and sudangrass (Sorghum sudanenses) were grown on the sludge-treated plots as test crops in 1987. Plant tissue samples were collected at different growth stages. Soil samples collected from the sludge-treated plots were extracted for Zn, Cu, Cd, Ni and Pb by 0.1M HCl, DTPA, Mehlich 1 and Mehlich 3 extractants. Statistically, Mehlich 1, Mehlich 3, DTPA and 0.1M HCl extractants all gave highly significant correlations with the plant accumulation of Zn, Cu, Ni and Cd, with DTPA giving the highest at any growth stage for both corn and sudangrass, but they gave poor correlations for Pb. Zinc removed by four extractants was more highly correlated with Zn accumulation by corn (r = 0.72 starstar to 0.93 starstar, p = 0.01) and sudangrass (r = 0.50 starstar to 0.96 starstar, p = 0.01) than other metals. Based on higher significant linear correlation coefficients (r), DTPA would be the extractant of choice for both crops; however the advantage to using the Mehlich 3 extractant is that, with a shorter shaking time of 5 min (compared to 2 hr for DTPA), it may be better suited for routine analysis of large numbers of soil samples. C1 SAVANNAH RIVER ECOL LAB,AIKEN,SC 29802. RP HE, X (reprint author), ALABAMA A&M UNIV,DEPT PLANT & SOIL SCI,NORMAL,AL 35762, USA. NR 19 TC 4 Z9 4 U1 0 U2 0 PU KLUWER ACADEMIC PUBL PI DORDRECHT PA SPUIBOULEVARD 50, PO BOX 17, 3300 AA DORDRECHT, NETHERLANDS SN 0049-6979 J9 WATER AIR SOIL POLL JI Water Air Soil Pollut. PD AUG PY 1991 VL 57-8 BP 913 EP 922 PG 10 WC Environmental Sciences; Meteorology & Atmospheric Sciences; Water Resources SC Environmental Sciences & Ecology; Meteorology & Atmospheric Sciences; Water Resources GA GP121 UT WOS:A1991GP12100093 ER PT J AU ADRIANO, DC AF ADRIANO, DC TI METALS IN SOILS, WATERS, PLANTS AND ANIMALS - PROCEEDINGS OF AN INTERNATIONAL-CONFERENCE, HELD IN ORLANDO, FLORIDA, APRIL 30 MAY 3, 1990 - PREFACE AND ACKNOWLEDGMENT SO WATER AIR AND SOIL POLLUTION LA English DT Editorial Material RP ADRIANO, DC (reprint author), UNIV GEORGIA,SAVANNAH RIVER ECOL LAB,AIKEN,SC 29801, USA. NR 0 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 0049-6979 J9 WATER AIR SOIL POLL JI Water Air Soil Pollut. PD AUG PY 1991 VL 57-8 BP R9 EP R10 PG 2 WC Environmental Sciences; Meteorology & Atmospheric Sciences; Water Resources SC Environmental Sciences & Ecology; Meteorology & Atmospheric Sciences; Water Resources GA GP121 UT WOS:A1991GP12100001 ER PT J AU GLASS, RJ PARLANGE, JY STEENHUIS, TS AF GLASS, RJ PARLANGE, JY STEENHUIS, TS TI IMMISCIBLE DISPLACEMENT IN POROUS-MEDIA - STABILITY ANALYSIS OF 3-DIMENSIONAL, AXISYMMETRICAL DISTURBANCES WITH APPLICATION TO GRAVITY-DRIVEN WETTING FRONT INSTABILITY SO WATER RESOURCES RESEARCH LA English DT Article ID LAYERED SOILS; INFILTRATION; MOVEMENT; WATER AB As water infiltrates downward into an air-filled, water wettable porous medium, the wetting front which forms may become unstable and allow the formation of downward moving fingers within the vadose zone. In this paper we first review stability criteria and estimated finger widths determined from linear stability theory in two-dimensional systems. Two approaches reported in the literature which employ different formulations for the interfacial boundary conditions, yield different estimates of the finger width. We extend the analyses to investigate finger diameter in three-dimensional systems by considering axisymmetric disturbances. Results of the three-dimensional analyses are illustrated through comparison to previously reported experimental results in three-dimensional systems. Because either approach gives similar results for low system fluxes, in practice, it probably will not matter which formulation is used. However, one approach represents the data better and contains only traditionally measured porous media properties. C1 CORNELL UNIV,DEPT AGR & BIOL ENGN,ITHACA,NY 14853. RP GLASS, RJ (reprint author), SANDIA NATL LABS,GEOSCI ANAL DIV 6315,ALBUQUERQUE,NM 87185, USA. NR 28 TC 59 Z9 59 U1 3 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 AUG PY 1991 VL 27 IS 8 BP 1947 EP 1956 DI 10.1029/91WR00836 PG 10 WC Environmental Sciences; Limnology; Water Resources SC Environmental Sciences & Ecology; Marine & Freshwater Biology; Water Resources GA FZ856 UT WOS:A1991FZ85600017 ER PT J AU NITAO, JJ BUSCHECK, TA AF NITAO, JJ BUSCHECK, TA TI INFILTRATION OF A LIQUID FRONT IN AN UNSATURATED, FRACTURED POROUS-MEDIUM SO WATER RESOURCES RESEARCH LA English DT Article ID FLUID-FLOW; SOILS AB We consider liquid infiltrating by gravity flow into a system of parallel, regularly spaced fractures in an unsaturated porous medium. The position of the fracture liquid front as a function of time, under some simplifying assumptions, is shown to obey a nonlinear integrodifferential equation. Approximate analytic solutions are developed, showing that the movement of the liquid front exhibits three major flow periods: (1) at early time, the frontal position is determined by the fracture inlet boundary condition and the gravity-driven flow behavior of the fracture with negligible influence by the matrix; (2) at intermediate time, matrix imbibition retards the frontal advance against the pull of gravity; (3) at late time, the matrix approaches saturation and the frontal velocity approaches a limiting value. A two-dimensional numerical model is used to confirm the approximate solutions. Implications of the model for nuclear waste storage are discussed. The analysis is applicable not only to fractured rock but also to lateral infiltration into coarse-grained sediments lying between layers of fine-grained soil. RP NITAO, JJ (reprint author), UNIV CALIF LAWRENCE LIVERMORE NATL LAB,DEPT EARTH SCI,L-206,POB 808,LIVERMORE,CA 94551, USA. NR 40 TC 54 Z9 57 U1 0 U2 4 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 AUG PY 1991 VL 27 IS 8 BP 2099 EP 2112 DI 10.1029/91WR01369 PG 14 WC Environmental Sciences; Limnology; Water Resources SC Environmental Sciences & Ecology; Marine & Freshwater Biology; Water Resources GA FZ856 UT WOS:A1991FZ85600029 ER PT J AU LENHARD, RJ PARKER, JC KALUARACHCHI, JJ AF LENHARD, RJ PARKER, JC KALUARACHCHI, JJ TI COMPARING SIMULATED AND EXPERIMENTAL HYSTERETIC 2-PHASE TRANSIENT FLUID-FLOW PHENOMENA SO WATER RESOURCES RESEARCH LA English DT Article ID GOVERNING MULTIPHASE FLOW; GAMMA-RADIATION SYSTEM; SOIL-WATER HYSTERESIS; HYDRAULIC CONDUCTIVITY; AIR ENCAPSULATION; UNSATURATED SOILS; MODEL; INFILTRATION; DRAINAGE AB A hysteretic model for two-phase permeability (k)-saturation (S)-pressure (P) relations is outlined that accounts for effects of nonwetting fluid entrapment. The model can be employed in unsaturated fluid flow computer codes to predict temporal and spatial fluid distributions. Consideration is given to hysteresis in S-P relations caused by contact angle, irregular pore geometry, and nonwetting fluid entrapment effects and to hysteresis in k-S relations caused by nonwetting fluid entrapment effects. An air-water flow experiment is conducted with a 72-cm vertical soil column where the water table is fluctuated to generate scanning S-P paths. Water contents are measured via a gamma radiation system, and water pressures are measured via pressure transducers connected to ceramic tensiometers inserted in the soil column. Computer simulations of the experiment employing the hysteretic k-S-P model and a nonhysteretic k-S-P are compared with measured water contents and pressures. Close agreement is found between experimental water contents and those predicted by a numerical code employing the hysteretic k-S-P relations. When nonhysteretic k-S-P constitutive relations are utilized, there is poor agreement between measured and predicted water saturations of the scanning paths. Only one more parameter is needed to model two-phase hysteretic fluid behavior than to model nonhysteretic behavior. Results of this study suggest that consideration should be given to effects of hysteresis in k-S-P relations to accurately predict fluid distributions. C1 SWISS FED INST TECHNOL, CH-8093 ZURICH, SWITZERLAND. VIRGINIA POLYTECH INST & STATE UNIV, BLACKSBURG, VA 24061 USA. RP LENHARD, RJ (reprint author), PACIFIC NW LAB, HYDROL SECT, K6 77, POB 999, RICHLAND, WA 99352 USA. RI Kaluarachchi, Jagath/A-6143-2010 NR 43 TC 56 Z9 59 U1 1 U2 7 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 AUG PY 1991 VL 27 IS 8 BP 2113 EP 2124 DI 10.1029/91WR01272 PG 12 WC Environmental Sciences; Limnology; Water Resources SC Environmental Sciences & Ecology; Marine & Freshwater Biology; Water Resources GA FZ856 UT WOS:A1991FZ85600030 ER PT J AU MORENO, L TSANG, CF AF MORENO, L TSANG, CF TI MULTIPLE-PEAK RESPONSE TO TRACER INJECTION TESTS IN SINGLE FRACTURES - A NUMERICAL STUDY SO WATER RESOURCES RESEARCH LA English DT Article ID FLOW; TRANSPORT AB Under certain conditions, when pulse tracer injection tests are performed in a single fracture with a regional flow field, the breakthrough curves may display multiple peaks. Furthermore, the shape of these curves may change when the injection flow rate is varied. In this paper the conditions under which the breakthrough curve may present multiple peaks are analyzed numerically using stochastically generated fractures. The dispersivities of these peaks are also calculated. It is found that the dispersivity is small for each of the peaks and that the dispersivities of the different peaks in a breakthrough curve are quite similar. The results presented in this paper may be equally applied to tracer tests in a two-dimensional strongly heterogeneous medium. C1 UNIV CALIF BERKELEY LAWRENCE BERKELEY LAB,DIV EARTH SCI,BERKELEY,CA 94720. RP MORENO, L (reprint author), ROYAL INST TECHNOL,DEPT CHEM ENGN,S-10044 STOCKHOLM 70,SWEDEN. NR 11 TC 28 Z9 28 U1 1 U2 2 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 SN 0043-1397 J9 WATER RESOUR RES JI Water Resour. Res. PD AUG PY 1991 VL 27 IS 8 BP 2143 EP 2150 DI 10.1029/91WR00507 PG 8 WC Environmental Sciences; Limnology; Water Resources SC Environmental Sciences & Ecology; Marine & Freshwater Biology; Water Resources GA FZ856 UT WOS:A1991FZ85600034 ER PT J AU DYKHUIZEN, RC AF DYKHUIZEN, RC TI A NEW COUPLING TERM FOR DUAL-POROSITY MODELS - REPLY SO WATER RESOURCES RESEARCH LA English DT Note RP DYKHUIZEN, RC (reprint author), SANDIA NATL LABS,DEPT FLUID & THERMAL SCI,POB 5800,ALBUQUERQUE,NM 87185, USA. NR 2 TC 2 Z9 2 U1 0 U2 1 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 AUG PY 1991 VL 27 IS 8 BP 2153 EP 2153 DI 10.1029/91WR01251 PG 1 WC Environmental Sciences; Limnology; Water Resources SC Environmental Sciences & Ecology; Marine & Freshwater Biology; Water Resources GA FZ856 UT WOS:A1991FZ85600036 ER PT J AU ZIMMERMAN, RW BODVARSSON, GS AF ZIMMERMAN, RW BODVARSSON, GS TI AN APPROXIMATE SOLUTION FOR ONE-DIMENSIONAL ABSORPTION IN UNSATURATED POROUS-MEDIA - REPLY SO WATER RESOURCES RESEARCH LA English DT Note ID WATER RP ZIMMERMAN, RW (reprint author), UNIV CALIF BERKELEY LAWRENCE BERKELEY LAB,DIV EARTH SCI,BERKELEY,CA 94720, USA. OI Zimmerman, Robert/0000-0001-6674-3403 NR 11 TC 1 Z9 1 U1 0 U2 1 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 AUG PY 1991 VL 27 IS 8 BP 2161 EP 2162 DI 10.1029/91WR01245 PG 2 WC Environmental Sciences; Limnology; Water Resources SC Environmental Sciences & Ecology; Marine & Freshwater Biology; Water Resources GA FZ856 UT WOS:A1991FZ85600039 ER PT J AU LACKS, SA GREENBERG, B AF LACKS, SA GREENBERG, B TI SEQUENTIAL CLONING BY A VECTOR WALKING ALONG THE CHROMOSOME SO GENE LA English DT Article DE GENOME MAPPING; BACTERIAL TRANSFORMATION; CIRCULAR SYNAPSIS; RESTRICTION ENZYMES; PBR322 REPLICON; STREPTOCOCCUS-PNEUMONIAE; PNEUMOCOCCUS ID ERYTHROMYCIN-RESISTANCE DETERMINANT; STREPTOCOCCUS-PNEUMONIAE; BACILLUS-SUBTILIS; ESCHERICHIA-COLI; DNA FRAGMENTS; PLASMID; TRANSFORMATION; GENE; YEAST; IDENTIFICATION AB A procedure was devised for sequential cloning of chromosomal DNA by cyclical integration and excision of a plasmid vector so that slightly overlapping chromosomal segments are successively cloned. The method depends on circular integration of the vector into the chromosome of a host nonpermissive for its replication, and on excision and reduction of a recombinant plasmid by use of an appropriately designed set of restriction enzyme sites in the vector. A vector suitable for cloning in Escherichia coli was constructed by combining a segment of pBR322 with a gene encoding chloramphenicol resistance expressible in many species. Sequential cloning was demonstrated in Streptococcus pneumoniae by extending a previously cloned segment of the region of the chromosome encoding maltosaccharide utilization by 8 kb in three cycles of cloning. Accuracy of the method was confirmed by hybridization of cloned DNA with chromosomal restriction fragments. It is pointed out that the similarity of the requisite genetic processes in bacteria and yeasts should allow use of the method for sequential cloning of yeast chromosomal DNA and of human or other mammalian DNA in artificial chromosomes of yeast. RP LACKS, SA (reprint author), BROOKHAVEN NATL LAB,DEPT BIOL,UPTON,NY 11973, USA. FU NIAID NIH HHS [AI14885]; NIGMS NIH HHS [GM29721] NR 39 TC 8 Z9 8 U1 1 U2 3 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0378-1119 J9 GENE JI Gene PD JUL 31 PY 1991 VL 104 IS 1 BP 11 EP 17 DI 10.1016/0378-1119(91)90458-N PG 7 WC Genetics & Heredity SC Genetics & Heredity GA GK076 UT WOS:A1991GK07600002 PM 1655574 ER PT J AU EMERY, HS SCHILD, D KELLOGG, DE MORTIMER, RK AF EMERY, HS SCHILD, D KELLOGG, DE MORTIMER, RK TI SEQUENCE OF RAD54, A SACCHAROMYCES-CEREVISIAE GENE INVOLVED IN RECOMBINATION AND REPAIR SO GENE LA English DT Article DE DOUBLE-STRAND BREAK REPAIR; NUCLEOTIDE-BINDING SITE; DNA DAMAGE INDUCTION; YEAST; RECOMBINANT DNA ID DNA-REPAIR; YEAST AB The complete nucleotide sequence of the RAD54 gene of the yeast Saccharomyces cerevisiae has been determined. The sequenced region contains an open reading frame of 2694 bp, and the predicted RAD54 protein has a potential nucleotide-binding site and possible nuclear targeting sequences. Northern analysis reveals a transcript of approx. 3.0 kb which is induced following x-ray irradiation. C1 UNIV CALIF BERKELEY,DEPT MOLEC & CELL BIOL,DONNER LAB 102,BERKELEY,CA 94720. UNIV CALIF BERKELEY LAWRENCE BERKELEY LAB,DIV CELL & MOLEC BIOL,BERKELEY,CA 94720. FU NIEHS NIH HHS [ES07075]; NIGMS NIH HHS [GM30990] NR 14 TC 93 Z9 95 U1 0 U2 1 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0378-1119 J9 GENE JI Gene PD JUL 31 PY 1991 VL 104 IS 1 BP 103 EP 106 DI 10.1016/0378-1119(91)90473-O PG 4 WC Genetics & Heredity SC Genetics & Heredity GA GK076 UT WOS:A1991GK07600017 PM 1916269 ER PT J AU ZHOU, JS KOSTIC, NM AF ZHOU, JS KOSTIC, NM TI KINETICS OF STATIC AND DIFFUSIVE ELECTRON-TRANSFER BETWEEN ZINC-SUBSTITUTED CYTOCHROME-C AND PLASTOCYANIN - INDICATIONS OF NONELECTROSTATIC INTERACTIONS BETWEEN HIGHLY CHARGED METALLOPROTEINS SO JOURNAL OF THE AMERICAN CHEMICAL SOCIETY LA English DT Article ID BLUE COPPER PROTEINS; WATER-SOLUBLE CARBODIIMIDE; IONIC-STRENGTH DEPENDENCE; FREE FLAVIN SEMIQUINONES; SPINACH PLASTOCYANIN; COVALENT COMPLEX; CHEMICAL MODIFICATION; METALLOCYTOCHROMES-C; BROWNIAN DYNAMICS; EMISSION-SPECTRA AB Cupriplastocyanin, pc(II), quenches the triplet state of zinc cytochrome c, 3Zn(cyt), by electron transfer as shown in Scheme I. All the experiments are done at pH 7.0. Nonredox modes of quenching are ruled out by detection of the cation radical Zn(cyt)+ and by experiments in which redox quenching is precluded. At the ionic strengths of 0.100 M and higher, the electron-transfer reaction occurs bimolecularly, via the encounter complex 3Zn(cyt)/pc(II); k(f) = (2.8 +/- 0.6) x 10(5) s-1, and the equilibrium constant K(a) depends on ionic strength. At the ionic strengths of 10 mM and lower, the reaction can be made to occur predominantly unimolecularly, within the preformed complex 3Zn(cyt)/pc(II); k(F) = (2.5 +/- 0.4) x 10(5) s-1 within 3Zn(cyt)/pc(II), and k(B) = (1.1 +/- 0.5) x 10(6) s-1 within Zn(cyt)+/pc(I). The rate constant k(f) is independent of ionic strength (in the range from 10 to 100 mM) and so is the rate constant k(F) (below 20 mM). The equality of k(f) and k(F) shows either that the encounter complex and the preformed complex have structures with equal electronic couplings and activation energies for electron transfer or that both complexes can reach such structures by fast rearrangement before the electron-transfer step. The estimated association constant K(a) for zinc cytochrome c and cupriplastocyanin at zero ionic strength is (2 +/- 1) x 10(7) M-1. Cytochrome c interacts similarly with various anionic metalloproteins, and replacement of iron with zinc does not noticeably alter these docking interactions. As the ionic strength increases, the efficiency of charge separation in the bimolecular reaction first increases and then decreases. At high ionic strength, even these charged proteins perhaps attract each other by hydrophobic or other nonelectrostatic forces. C1 IOWA STATE UNIV SCI & TECHNOL,US DOE,AMES LAB,AMES,IA 50011. IOWA STATE UNIV SCI & TECHNOL,DEPT CHEM,AMES,IA 50011. NR 81 TC 47 Z9 47 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 JUL 31 PY 1991 VL 113 IS 16 BP 6067 EP 6073 DI 10.1021/ja00016a021 PG 7 WC Chemistry, Multidisciplinary SC Chemistry GA FZ533 UT WOS:A1991FZ53300021 ER PT J AU DYER, RB PETERSON, KA STOUTLAND, PO WOODRUFF, WH AF DYER, RB PETERSON, KA STOUTLAND, PO WOODRUFF, WH TI ULTRAFAST PHOTOINDUCED LIGAND TRANSFER IN CARBONMONOXY CYTOCHROME-C-OXIDASE - OBSERVATION BY PICOSECOND INFRARED-SPECTROSCOPY SO JOURNAL OF THE AMERICAN CHEMICAL SOCIETY LA English DT Note ID SPERM WHALE; BINDING; HEMOGLOBIN; RESOLUTION; REDUCTION; SITE C1 UNIV CALIF LOS ALAMOS SCI LAB,ISOTOPE & STRUCT CHEM GRP,LOS ALAMOS,NM 87545. RP DYER, RB (reprint author), UNIV CALIF LOS ALAMOS SCI LAB,PHOTOCHEM & PHOTOPHYS GRP,CLS-4,MAIL STOP J-567,LOS ALAMOS,NM 87545, USA. NR 17 TC 47 Z9 48 U1 0 U2 4 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 SN 0002-7863 J9 J AM CHEM SOC JI J. Am. Chem. Soc. PD JUL 31 PY 1991 VL 113 IS 16 BP 6276 EP 6277 DI 10.1021/ja00016a057 PG 2 WC Chemistry, Multidisciplinary SC Chemistry GA FZ533 UT WOS:A1991FZ53300057 ER PT J AU NOURBAKHSH, S NORWOOD, K HE, GZ NG, CY AF NOURBAKHSH, S NORWOOD, K HE, GZ NG, CY TI PHOTOIONIZATION STUDY OF SUPERSONICALLY COOLED POLYATOMIC RADICALS - HEAT OF FORMATION OF CH3S+ SO JOURNAL OF THE AMERICAN CHEMICAL SOCIETY LA English DT Note ID KINETIC-ENERGY RELEASE; METASTABLE ION CHARACTERISTICS; 193 NM; COLLISIONAL ACTIVATION; PHOTO-IONIZATION; CSH3+ IONS; THIOFORMALDEHYDE; FRAGMENTATION; CLUSTERS; CH2SH+ C1 IOWA STATE UNIV SCI & TECHNOL,US DOE,AMES LAB,AMES,IA 50011. IOWA STATE UNIV SCI & TECHNOL,DEPT CHEM,AMES,IA 50011. NR 35 TC 42 Z9 43 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 JUL 31 PY 1991 VL 113 IS 16 BP 6311 EP 6312 DI 10.1021/ja00016a080 PG 2 WC Chemistry, Multidisciplinary SC Chemistry GA FZ533 UT WOS:A1991FZ53300080 ER PT J AU DELPLANCKE, MP POWERS, JM VANDENTOP, GJ SOMORJAI, GA AF DELPLANCKE, MP POWERS, JM VANDENTOP, GJ SOMORJAI, GA TI PREPARATION OF SIXCYHZ FILMS FROM METHYLSILANE BY PLASMA-ENHANCED CHEMICAL VAPOR-DEPOSITION SO THIN SOLID FILMS LA English DT Article ID SILICON-CARBIDE FILMS; RAY PHOTOELECTRON-SPECTROSCOPY; GLOW-DISCHARGE; THIN-FILMS; ELECTRONIC-STRUCTURE; HYDROGEN DILUTION; ALLOY-FILMS; SIC-H; TETRAMETHYLSILANE; ETHYLENE AB Hydrogenated amorphous silicon carbide (Si(x)C(y)H(z)) films were synthesized by plasma-enhanced chemical vapor deposition using monomethylsilane(CH3SiH3)as the precursor. Silicon (100) wafers and gold foils were employed as substrates. A mass spectrometric analysis of the plasma showed that the advantage of using monomethylsilane relative to a silane-hydrocarbon mixture is that the majority of the Si-C bonds were preserved in the CH3SiH3 plasma. The composition and the morphology of the Si(x)C(y)H(z) films was studied via X-ray photoelectron spectroscopy, Auger electron spectroscopy, and scanning electron microscopy as a function of the substrate temperature, composition of the ion flux bombarding the surface, and kinetic energy of these ions. The oxygen content of the films was found to decrease monotonically with increasing substrate temperature. C1 UNIV CALIF BERKELEY,DEPT CHEM,BERKELEY,CA 94720. UNIV CALIF BERKELEY LAWRENCE BERKELEY LAB,DIV MAT & CHEM SCI,BERKELEY,CA 94720. RP DELPLANCKE, MP (reprint author), UNIV CALIF BERKELEY LAWRENCE BERKELEY LAB,CTR ADV MAT,BERKELEY,CA 94720, USA. NR 46 TC 26 Z9 26 U1 0 U2 6 PU ELSEVIER SCIENCE SA LAUSANNE PI LAUSANNE 1 PA PO BOX 564, 1001 LAUSANNE 1, SWITZERLAND SN 0040-6090 J9 THIN SOLID FILMS JI Thin Solid Films PD JUL 30 PY 1991 VL 202 IS 2 BP 289 EP 298 DI 10.1016/0040-6090(91)90100-C PG 10 WC Materials Science, Multidisciplinary; Materials Science, Coatings & Films; Physics, Applied; Physics, Condensed Matter SC Materials Science; Physics GA GC568 UT WOS:A1991GC56800013 ER PT J AU PERN, FJ NOUFI, R MASON, A FRANZ, A AF PERN, FJ NOUFI, R MASON, A FRANZ, A TI CHARACTERIZATIONS OF ELECTRODEPOSITED CUINSE2 THIN-FILMS - STRUCTURE, DEPOSITION AND FORMATION MECHANISMS SO THIN SOLID FILMS LA English DT Article AB Effects of annealing conditions on the structure characteristics of electrodeposited CuInSe2 thin films were investigated by using X-ray diffractometry. For copper-rich thin films, the preferred orientation factor f(112) at (112) direction and the effective grain size increased as the annealing temperature and time increased. Less profound effects were observed for the indium-rich films. The annealed copper-rich films are predominantly chalcopyrite and highly conductive, while annealed indium-rich films are mainly sphalerite and very resistive. A structural transition from chalcopyrite to sphalerite was observed for the first time on the electrodeposited CuInSe2 as the composition of the thin films varied from copper rich to indium rich. The presence of oxygen during annealing was found detrimental to the films, resulting in the formation of indium oxides due to partial oxidation of indium and associated loss of selenium and a large increase in the film conductivity. Effects of various chemical treatments on film composition, morphology, and corresponding structural change were also studied to elucidate the thin film deposition and formation mechanisms. The results showed that the as-deposited films are made of CuInSe2, Cu(x)Se, In(y)Se, and selenium. Depending on the sequence of annealing and chemical treatments, the resulting thin films could be either copper-rich chalcopyrites or indium-rich sphalerites. RP PERN, FJ (reprint author), SOLAR ENERGY RES INST,GOLDEN,CO 80401, USA. NR 22 TC 55 Z9 55 U1 0 U2 3 PU ELSEVIER SCIENCE SA LAUSANNE PI LAUSANNE 1 PA PO BOX 564, 1001 LAUSANNE 1, SWITZERLAND SN 0040-6090 J9 THIN SOLID FILMS JI Thin Solid Films PD JUL 30 PY 1991 VL 202 IS 2 BP 299 EP 314 DI 10.1016/0040-6090(91)90101-3 PG 16 WC Materials Science, Multidisciplinary; Materials Science, Coatings & Films; Physics, Applied; Physics, Condensed Matter SC Materials Science; Physics GA GC568 UT WOS:A1991GC56800014 ER PT J AU KARIM, A ARENDT, BH FELCHER, GP RUSSELL, TP AF KARIM, A ARENDT, BH FELCHER, GP RUSSELL, TP TI PREPARATION AND CHARACTERIZATION OF THIN POLYMER BILAYER FILMS BY NEUTRON REFLECTION SO THIN SOLID FILMS LA English DT Article ID SECONDARY AB Neutron reflection is used to study the concentration profile at the interface between two thin layers of polymer. The first layer was prepared by spin casting on a silicon substrate; the second film was similarly prepared on a different substrate, floated off in water and placed over the first film. As prepared, the polymer-polymer interface has a contaminant film of water with approximately 0.26 mg m-2 surface coverage, which can be removed by annealing under vacuum at temperatures close to the glass transition temperature of the polymer. The annealed bilayered specimen does not show any trace of interdiffusion between the two polymers, even when the two polymers are chemically identical. C1 ARGONNE NATL LAB,ARGONNE,IL 60439. IBM CORP,DIV RES,SAN JOSE,CA 95120. NR 6 TC 7 Z9 7 U1 0 U2 3 PU ELSEVIER SCIENCE SA LAUSANNE PI LAUSANNE 1 PA PO BOX 564, 1001 LAUSANNE 1, SWITZERLAND SN 0040-6090 J9 THIN SOLID FILMS JI Thin Solid Films PD JUL 30 PY 1991 VL 202 IS 2 BP 345 EP 350 DI 10.1016/0040-6090(91)90105-7 PG 6 WC Materials Science, Multidisciplinary; Materials Science, Coatings & Films; Physics, Applied; Physics, Condensed Matter SC Materials Science; Physics GA GC568 UT WOS:A1991GC56800018 ER PT J AU ZIGLER, A BURKHALTER, PG NAGEL, DJ ROSEN, MD BOYER, K GIBSON, G LUK, TS MCPHERSON, A RHODES, CK AF ZIGLER, A BURKHALTER, PG NAGEL, DJ ROSEN, MD BOYER, K GIBSON, G LUK, TS MCPHERSON, A RHODES, CK TI MEASUREMENT OF ENERGY PENETRATION DEPTH OF SUBPICOSECOND LASER ENERGY INTO SOLID DENSITY MATTER SO APPLIED PHYSICS LETTERS LA English DT Article ID CALIBRATION; PLASMAS; CRYSTAL AB The energy penetration depth characteristic of the interaction of intense subpicosecond (approximately 600 fs) ultraviolet (248 nm) laser radiation with solid density material has been experimentally determined. This was accomplished by using a series of ultraviolet transmitting targets consisting of a fused silica (SiO2) substrate coated with an 80-600 nm layer of MgF2. The measurement of He-like and H-like Si and Mg lines, as a function of MgF2 thickness, enabled the determination of the energy penetration depth. It was found that this depth falls in the range of 250-300 nm for a laser intensity of approximately 3 X 10(16) W/cm2. Based on numerical simulations, it is estimated that solid density material to a depth of approximately 250 nm is heated to an electron temperature of approximately 500 eV. C1 UNIV CALIF LAWRENCE LIVERMORE NATL LAB,LIVERMORE,CA 94550. UNIV ILLINOIS,CHICAGO,IL 60680. FM TECHNOL,FAIRFAX,VA 22032. RP ZIGLER, A (reprint author), USN,RES LAB,WASHINGTON,DC 20375, USA. NR 15 TC 31 Z9 31 U1 1 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 JUL 29 PY 1991 VL 59 IS 5 BP 534 EP 536 DI 10.1063/1.105430 PG 3 WC Physics, Applied SC Physics GA FY713 UT WOS:A1991FY71300014 ER PT J AU HEBNER, GA HAYS, GN AF HEBNER, GA HAYS, GN TI MEASURED PRESSURE BROADENING AND SHIFT RATES OF THE 1.73-MU-M (5D[3/2]1-6P[5/2]2) TRANSITION OF XENON SO APPLIED PHYSICS LETTERS LA English DT Article ID ELECTRON-BEAM; ELECTROIONIZATION LASER; XE-LASER; AR-XE; MIXTURES AB Pressure broadening and line center shift rates as a function of helium, neon, and argon pressure have been measured for the 1.73-mu-m (5d[3/2]1-6p[5/2]2) transition in xenon. The pressure broadening rates are 20.3 +/- 6.4, 12.7 +/- 3.5, and 19.7 +/- 2.9 MHz/Torr for helium, neon, and argon buffers, respectively . RP HEBNER, GA (reprint author), SANDIA NATL LABS,DIV 1128,ALBUQUERQUE,NM 87185, USA. NR 19 TC 17 Z9 17 U1 0 U2 0 PU AMER INST PHYSICS PI WOODBURY PA CIRCULATION FULFILLMENT DIV, 500 SUNNYSIDE BLVD, WOODBURY, NY 11797-2999 SN 0003-6951 J9 APPL PHYS LETT JI Appl. Phys. Lett. PD JUL 29 PY 1991 VL 59 IS 5 BP 537 EP 539 DI 10.1063/1.105431 PG 3 WC Physics, Applied SC Physics GA FY713 UT WOS:A1991FY71300015 ER PT J AU SEAGER, CH ANDERSON, RA AF SEAGER, CH ANDERSON, RA TI 2-STEP DEBONDING OF HYDROGEN FROM BORON ACCEPTORS IN SILICON SO APPLIED PHYSICS LETTERS LA English DT Article ID CRYSTALLINE SILICON; ANOMALOUS MUONIUM; DIFFUSION; DIAMOND; MOTION; DRIFT AB Previous work has demonstrated that B.H pairs in silicon thermally dissociate obeying simple first-order kinetics if they are located in a region depleted of majority carriers. B.H debonding in equilibrium, however, is a slower, more complex process. We have investigated the dissociation of B.H pairs under a variety of equilibrium and nonequilibrium conditions and have demonstrated that the dissociation process is strongly influenced by the local concentration of majority and minority carriers. In particular, we show that injection of minority carriers can markedly accelerate the dissociation process. A model is proposed which suggests that hydrogen released from an acceptor, while initially positive, must always be neutralized before escape is possible. This picture correctly describes the time dependence of debonding in both equilibrium and forward-biased diodes. RP SEAGER, CH (reprint author), SANDIA NATL LABS,POB 5800,ALBUQUERQUE,NM 87185, USA. NR 24 TC 17 Z9 17 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 JUL 29 PY 1991 VL 59 IS 5 BP 585 EP 587 DI 10.1063/1.105394 PG 3 WC Physics, Applied SC Physics GA FY713 UT WOS:A1991FY71300031 ER PT J AU FOLTYN, SR DYE, RC OTT, KC PETERSON, E HUBBARD, KM HUTCHINSON, W MUENCHAUSEN, RE ESTLER, RC WU, XD AF FOLTYN, SR DYE, RC OTT, KC PETERSON, E HUBBARD, KM HUTCHINSON, W MUENCHAUSEN, RE ESTLER, RC WU, XD TI TARGET MODIFICATION IN THE EXCIMER LASER DEPOSITION OF YBA2CU3O7-X THIN-FILMS SO APPLIED PHYSICS LETTERS LA English DT Article ID ABLATION AB Under conditions used for pulsed laser deposition (308 nm, 20 ns, 2-8 J/cm2) of Y-Ba-Cu-O superconducting thin films, we have measured a pronounced decrease in deposition rate with cumulative laser exposure of the target. This decay in rate is accompanied by evolution on the target surface of microscopic columnar structures, having yttrium-enriched surfaces, which are aligned in the direction of the incident laser beam (45-degrees). Neither the vapor plume direction nor film stoichiometry is affected by the presence of these oriented, chemically altered surface features. RP FOLTYN, SR (reprint author), UNIV CALIF LOS ALAMOS SCI LAB,LOS ALAMOS,NM 87545, USA. NR 13 TC 97 Z9 98 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 JUL 29 PY 1991 VL 59 IS 5 BP 594 EP 596 DI 10.1063/1.106386 PG 3 WC Physics, Applied SC Physics GA FY713 UT WOS:A1991FY71300034 ER PT J AU HOTCHKIS, MAC DURELL, JL FITZGERALD, JB MOWBRAY, AS PHILLIPS, WR AHMAD, I CARPENTER, MP JANSSENS, RVF KHOO, TL MOORE, EF MORSS, LR BENET, P YE, D AF HOTCHKIS, MAC DURELL, JL FITZGERALD, JB MOWBRAY, AS PHILLIPS, WR AHMAD, I CARPENTER, MP JANSSENS, RVF KHOO, TL MOORE, EF MORSS, LR BENET, P YE, D TI ROTATIONAL BANDS IN THE MASS-100 REGION SO NUCLEAR PHYSICS A LA English DT Article DE CM-248 SF; MEASURED E-GAMMA, GAMMA-GAMMA-COIN; SR-98, SR-99, SR-100, Y-99, Y-101, ZR-100, ZR-101, ZR-102, ZR-103, ZR-10; 104, NB-101, NB-103, NB-105, MO-102, MO-103, MO-104, MO-105, MO-106, MO-107, MO ID APPROXIMATELY 100 REGION; HIGHLY DEFORMED Y-99; NEUTRON-RICH NUCLEI; DEFORMATION; ISOTOPES; SR; ZR; QUASIPARTICLE; TRANSITION; STATES AB Rotational bands up to spins of almost-equal-to 10HBAR have been studied in even-even and odd-A nuclei in the mass 100 region, by observing prompt gamma-rays from the spontaneous fission of Cm-248. Transitions in the neutron-rich nuclei 103Zr, 104Zr, 107Mo and 108Mo have been observed for the first time, and evidence for a band in 105Nb is presented. Rotational bands are also reported in 98-100Sr, 99-101Y 100-102Zr, 101-103Nb and 102-106Mo. In most cases these bands have been extended to much higher spins than previously known. The data on the even-even nuclei provide information on deformation trends in this region. The level structures of the odd-A nuclei indicate which Nilsson orbitals lie close to the Fermi level. Bands based on the 5/2+[422] and 5/2-[303] configurations are identified in the odd-A nuclei with Z = 39 and 41. Evidence is presented that certain bands observed in N = 61 and 63 nuclei are built on the 5/2-[532] configuration, and the role of the neutron h11/2 orbital in stabilizing the deformation in this region is discussed. C1 ARGONNE NATL LAB,ARGONNE,IL 60439. PURDUE UNIV,W LAFAYETTE,IN 47907. UNIV NOTRE DAME,NOTRE DAME,IN 46556. RP HOTCHKIS, MAC (reprint author), UNIV MANCHESTER,DEPT PHYS,MANCHESTER M13 9PL,LANCS,ENGLAND. RI Carpenter, Michael/E-4287-2015 OI Carpenter, Michael/0000-0002-3237-5734 NR 41 TC 188 Z9 190 U1 0 U2 2 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0375-9474 J9 NUCL PHYS A JI Nucl. Phys. A PD JUL 29 PY 1991 VL 530 IS 1 BP 111 EP 134 DI 10.1016/0375-9474(91)90758-X PG 24 WC Physics, Nuclear SC Physics GA GB569 UT WOS:A1991GB56900007 ER PT J AU CLEVELAND, MG PRITCHETT, T AF CLEVELAND, MG PRITCHETT, T TI HORIZONTAL SUPERSYMMETRY AND WEYL CHARACTER FORMULAS SO NUCLEAR PHYSICS B LA English DT Article ID ATIYAH-SINGER INDEX; QUANTUM-MECHANICS AB The concept of a horizontal supersymmetry over a reductive coset space, G/H, is developed. By an adaptation of the Borel-Weil theory to vector bundles, an alternate form of the Weyl character formula is obtained through a supersymmetric index calculation. This is then shown to produce a relation between the character of an element of the group G and the character in the appropriate representation for the corresponding element of the subgroup H. The example of SU(3)/SU(2) x U(1) for the 3 representation is studied in detail. C1 UNIV CALIF BERKELEY,DEPT PHYS,BERKELEY,CA 94720. RP CLEVELAND, MG (reprint author), UNIV CALIF BERKELEY LAWRENCE BERKELEY LAB,BERKELEY,CA 94720, USA. NR 13 TC 0 Z9 0 U1 0 U2 0 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0550-3213 J9 NUCL PHYS B JI Nucl. Phys. B PD JUL 29 PY 1991 VL 359 IS 1 BP 75 EP 90 DI 10.1016/0550-3213(91)90293-7 PG 16 WC Physics, Particles & Fields SC Physics GA FT579 UT WOS:A1991FT57900003 ER PT J AU KOLB, EW TURNER, MS CHAKRAVORTY, A SCHRAMM, DN AF KOLB, EW TURNER, MS CHAKRAVORTY, A SCHRAMM, DN TI CONSTRAINTS FROM PRIMORDIAL NUCLEOSYNTHESIS ON THE MASS OF THE TAU NEUTRINO SO PHYSICAL REVIEW LETTERS LA English DT Article ID BIG-BANG NUCLEOSYNTHESIS; THERMONUCLEAR REACTION-RATES; COSMOLOGICAL CONSTRAINTS; PARTICLES; SYMMETRY AB The familiar nucleosynthesis constraint on the number of neutrino species, N(v) less-than-or-equal-to 3.4, applies to massless neutrino species. An MeV-mass neutrino can have even greater impact, and we show that primordial nucleosynthesis excludes a tau-neutrino mass from 0.3 to 25 MeV (Dirac) and 0.5 to 25 MeV (Majorana) provided that its lifetime tau-v greater-than-or-similar-to sec, and from 0.3 to 30 MeV (Dirac) and 0.5 to 32 MeV (Majorana) for tau-v greater-than-or-similar-to 10(3) sec. A modest improvement in the laboratory mass limit - from 35 to 25 MeV - would imply that the tau-neutrino mass must be less than 0.5 MeV (provided tau-v greater-than-or-similar-to 1 sec). C1 UNIV CHICAGO,ENRICO FERMI INST,DEPT ASTRON & ASTROPHYS,CHICAGO,IL 60637. UNIV CHICAGO,DEPT PHYS,CHICAGO,IL 60637. RP KOLB, EW (reprint author), FERMI NATL ACCELERATOR LAB,NASA,CTR ASTROPHYS,BATAVIA,IL 60510, USA. NR 32 TC 71 Z9 71 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 JUL 29 PY 1991 VL 67 IS 5 BP 533 EP 536 DI 10.1103/PhysRevLett.67.533 PG 4 WC Physics, Multidisciplinary SC Physics GA FY505 UT WOS:A1991FY50500002 ER PT J AU NIR, Y QUINN, HR AF NIR, Y QUINN, HR TI MEASURING CABIBBO-KOBAYASHI-MASKAWA PARAMETERS WITH CP ASYMMETRY AND ISOSPIN ANALYSIS IN B-PI-K SO PHYSICAL REVIEW LETTERS LA English DT Article ID DECAYS; VIOLATION AB Isospin relations are used to eliminate hadronic uncertainties in various CP asymmetries in B0 decays via b --> uuBARs, e.g., B0 --> pi-0 K(S). A clean measurement of the angle-alpha of the unitarity triangle is thus made possible. The magnitudes of the tree and the penguin amplitudes can be measured. C1 STANFORD UNIV,STANFORD LINEAR ACCELERATOR CTR,STANFORD,CA 94309. RP NIR, Y (reprint author), WEIZMANN INST SCI,DEPT PHYS,IL-76100 REHOVOT,ISRAEL. NR 6 TC 68 Z9 68 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 JUL 29 PY 1991 VL 67 IS 5 BP 541 EP 544 DI 10.1103/PhysRevLett.67.541 PG 4 WC Physics, Multidisciplinary SC Physics GA FY505 UT WOS:A1991FY50500004 ER PT J AU FRANKLE, CM BOWMAN, JD BUSH, JE DELHEIJ, PPJ GOULD, CR HAASE, DG KNUDSON, JN MITCHELL, GE PENTTILA, S POSTMA, H ROBERSON, NR SEESTROM, SJ SZYMANSKI, JJ YOO, SH YUAN, VW ZHU, X AF FRANKLE, CM BOWMAN, JD BUSH, JE DELHEIJ, PPJ GOULD, CR HAASE, DG KNUDSON, JN MITCHELL, GE PENTTILA, S POSTMA, H ROBERSON, NR SEESTROM, SJ SZYMANSKI, JJ YOO, SH YUAN, VW ZHU, X TI SIGN CORRELATIONS AND PARITY NONCONSERVATION FOR NEUTRON RESONANCES IN TH-232 SO PHYSICAL REVIEW LETTERS LA English DT Article ID SYMMETRIES; VIOLATION; TESTS AB Parity-nonconserving longitudinal analyzing powers were measured for 23 p-wave neutron resonances in Th-232. Seven resonances show effects of greater than 2-sigma statistical significance (95% confidence) - the largest sample yet measured in a single nucleus. All seven analyzing powers have positive sign. Strong sign correlations arc not a feature of the conventional statistical model of parity mixing between compound nuclear states. The results suggest that the mechanism of parity violation in resonance reactions is more complicated than previously assumed. C1 TRIANGLE UNIV NUCL LAB,DURHAM,NC 27706. UNIV CALIF LOS ALAMOS SCI LAB,LOS ALAMOS,NM 87545. TRIUMF,VANCOUVER V6T 2A3,BC,CANADA. DELFT UNIV TECHNOL,DELFT,NETHERLANDS. DUKE UNIV,DURHAM,NC 27706. RP FRANKLE, CM (reprint author), N CAROLINA STATE UNIV,RALEIGH,NC 27695, USA. RI Gould, Christopher/M-7676-2013; OI Bush, Judith/0000-0001-6240-4121 NR 18 TC 101 Z9 101 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 JUL 29 PY 1991 VL 67 IS 5 BP 564 EP 567 DI 10.1103/PhysRevLett.67.564 PG 4 WC Physics, Multidisciplinary SC Physics GA FY505 UT WOS:A1991FY50500010 ER PT J AU KOROLIJA, M SHAPIRA, D CINDRO, N DELCAMPO, JG KIM, HJ TEH, K SHEA, JY AF KOROLIJA, M SHAPIRA, D CINDRO, N DELCAMPO, JG KIM, HJ TEH, K SHEA, JY TI EXCLUSIVE P-P CORRELATIONS FROM THE NI-58+NI-58 REACTION AT ALMOST-EQUAL-TO 15 MEV NUCLEON SO PHYSICAL REVIEW LETTERS LA English DT Article ID EMISSION; COLLISIONS; ENERGY AB Exclusive p-p correlations from the Ni-58 + Ni-58 reaction at 850 MeV incident energy have been measured. The enhancement in the p-p correlation function observed for small values of DELTA-p with a gate on upsilon-rel is satisfactorily explained by stochastic proton emission followed by the p-p final-state interaction. A strong dependence of the p-p correlation function on the relative angle between the two-proton c.m. and the fragment velocities has been found. Also a dependence of the p-p correlation function on the DELTA-p orientation with respect to the plane defined by the two-proton c.m. and the fragment velocities has been observed. This latter behavior has been attributed to angular momentum effects. C1 JOINT INST HEAVY ION RES,OAK RIDGE,TN 37831. OAK RIDGE NATL LAB,OAK RIDGE,TN 37831. VANDERBILT UNIV,DEPT PHYS & ASTRON,NASHVILLE,TN 37235. RP KOROLIJA, M (reprint author), RUDJER BOSKOVIC INST,YU-41001 ZAGREB,YUGOSLAVIA. NR 17 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 JUL 29 PY 1991 VL 67 IS 5 BP 572 EP 575 DI 10.1103/PhysRevLett.67.572 PG 4 WC Physics, Multidisciplinary SC Physics GA FY505 UT WOS:A1991FY50500012 ER PT J AU KELLOGG, GL VOTER, AF AF KELLOGG, GL VOTER, AF TI SURFACE-DIFFUSION MODES FOR PT DIMERS AND TRIMERS ON PT(001) SO PHYSICAL REVIEW LETTERS LA English DT Article ID ADATOM; CLUSTERS; ATOMS AB Field-ion-microscope observations and molecular statics calculations using embedded-atom-method potentials have identified the surface diffusion modes for Pt dimers and trimers on Pt(001). Dimers migrate by a series of displacements involving exchange between one of the dimer atoms and a substrate atom and have a lower activation barrier for diffusion than monomers. Trimer diffusion involves both exchange and hopping displacements and has an activation barrier comparable to monomers. C1 UNIV CALIF LOS ALAMOS SCI LAB,LOS ALAMOS,NM 87545. RP KELLOGG, GL (reprint author), SANDIA NATL LABS,ALBUQUERQUE,NM 87185, USA. OI Voter, Arthur/0000-0001-9788-7194 NR 16 TC 89 Z9 91 U1 1 U2 2 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 0031-9007 J9 PHYS REV LETT JI Phys. Rev. Lett. PD JUL 29 PY 1991 VL 67 IS 5 BP 622 EP 625 DI 10.1103/PhysRevLett.67.622 PG 4 WC Physics, Multidisciplinary SC Physics GA FY505 UT WOS:A1991FY50500025 ER PT J AU WANDER, A VANHOVE, MA SOMORJAI, GA AF WANDER, A VANHOVE, MA SOMORJAI, GA TI MOLECULE-INDUCED DISPLACIVE RECONSTRUCTION IN A SUBSTRATE SURFACE - ETHYLIDYNE ADSORBED ON RH(111) STUDIED BY LOW-ENERGY-ELECTRON DIFFRACTION SO PHYSICAL REVIEW LETTERS LA English DT Article ID LEED STRUCTURE-ANALYSIS; METAL-INDUCED RECONSTRUCTION; RELAXATION; ADSORPTION; MECHANISM; DIFFUSION; AG(110) AB It is found for the first time that a molecule can induce a displacive reconstruction in the substrate on which it is adsorbed. This is observed in a refined structure determination of Rh(111)(2 x 2)-C2H3, in which C2H3 (ethylidyne) is adsorbed on the Rh(111) single-crystal surface. This result strengthens an earlier hypothesis that catalytic reactions are usually accompanied by distortions in the catalyst, which can profoundly affect reaction rates and selectivities. C1 UNIV CALIF BERKELEY,DEPT CHEM,BERKELEY,CA 94720. RP WANDER, A (reprint author), UNIV CALIF BERKELEY LAWRENCE BERKELEY LAB,CTR ADV MAT,DIV MAT SCI,BERKELEY,CA 94720, USA. RI Van Hove, Michel/A-9862-2008 OI Van Hove, Michel/0000-0002-8898-6921 NR 24 TC 128 Z9 128 U1 1 U2 7 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 0031-9007 J9 PHYS REV LETT JI Phys. Rev. Lett. PD JUL 29 PY 1991 VL 67 IS 5 BP 626 EP 628 DI 10.1103/PhysRevLett.67.626 PG 3 WC Physics, Multidisciplinary SC Physics GA FY505 UT WOS:A1991FY50500026 ER PT J AU BIGOT, JY PORTELLA, MT SCHOENLEIN, RW CUNNINGHAM, JE SHANK, CV AF BIGOT, JY PORTELLA, MT SCHOENLEIN, RW CUNNINGHAM, JE SHANK, CV TI 2-DIMENSIONAL CARRIER-CARRIER SCREENING IN A QUANTUM-WELL SO PHYSICAL REVIEW LETTERS LA English DT Article ID ORIENTATIONAL RELAXATION; OPTICAL PULSES; GAAS; EXCITONS AB The behavior of carrier-carrier screening is investigated in a GaAs-GaAlAs quantum-well structure by measuring the band-to-band polarization dephasing with femtosecond photon echoes. The variation of the electron-hole-polarization dephasing time with the carrier concentration reveals the two-dimensional character of the short-range screening between the interacting carriers. RP BIGOT, JY (reprint author), UNIV CALIF BERKELEY LAWRENCE BERKELEY LAB,CYCLOTRON RD,MS-70-193A,BERKELEY,CA 94720, USA. RI Schoenlein, Robert/D-1301-2014 OI Schoenlein, Robert/0000-0002-6066-7566 NR 20 TC 103 Z9 103 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 JUL 29 PY 1991 VL 67 IS 5 BP 636 EP 639 DI 10.1103/PhysRevLett.67.636 PG 4 WC Physics, Multidisciplinary SC Physics GA FY505 UT WOS:A1991FY50500029 ER PT J AU CIVALE, L MARWICK, AD WORTHINGTON, TK KIRK, MA THOMPSON, JR KRUSINELBAUM, L SUN, Y CLEM, JR HOLTZBERG, F AF CIVALE, L MARWICK, AD WORTHINGTON, TK KIRK, MA THOMPSON, JR KRUSINELBAUM, L SUN, Y CLEM, JR HOLTZBERG, F TI VORTEX CONFINEMENT BY COLUMNAR DEFECTS IN YBA2CU3O7 CRYSTALS - ENHANCED PINNING AT HIGH FIELDS AND TEMPERATURES SO PHYSICAL REVIEW LETTERS LA English DT Article ID ION IRRADIATION; II SUPERCONDUCTORS; CRITICAL CURRENTS; FILMS AB We report the realization of a microstructure which leads to very strong high-temperature flux pinning in YBa2CU3O7 crystals. Aligned discontinuous columns of damaged material, about 50 angstrom in diameter and more than 15-mu-m long, are produced by 580-MeV Sn-ion irradiation. The enhancement of flux pinning is largest when the applied magnetic field is aligned with these tracks. At high temperatures and fields the pinning is much greater than that produced by random point defects, and causes a considerable enlargement of the irreversibility region in the H-T plane. C1 ARGONNE NATL LAB,DIV MAT SCI,ARGONNE,IL 60439. OAK RIDGE NATL LAB,DIV SOLID STATE,OAK RIDGE,TN 37831. IOWA STATE UNIV SCI & TECHNOL,US DOE,AMES LAB,AMES,IA 50011. IOWA STATE UNIV SCI & TECHNOL,DEPT PHYS,AMES,IA 50011. RP CIVALE, L (reprint author), IBM CORP,THOMAS J WATSON RES CTR,YORKTOWN HTS,NY 10598, USA. NR 20 TC 1017 Z9 1022 U1 3 U2 35 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 JUL 29 PY 1991 VL 67 IS 5 BP 648 EP 651 DI 10.1103/PhysRevLett.67.648 PG 4 WC Physics, Multidisciplinary SC Physics GA FY505 UT WOS:A1991FY50500032 ER PT J AU LONGTIN, A BULSARA, A MOSS, F AF LONGTIN, A BULSARA, A MOSS, F TI TIME-INTERVAL SEQUENCES IN BISTABLE SYSTEMS AND THE NOISE-INDUCED TRANSMISSION OF INFORMATION BY SENSORY NEURONS SO PHYSICAL REVIEW LETTERS LA English DT Article ID AUDITORY-NERVE FIBERS; BEHAVIOR; CYCLE AB We discuss the two time-interval sequences which play a crucial role in studies of escape times in bistable systems driven by periodic functions embedded in noise. We demonstrate that the probability density of escape times for one of the sequences exhibits all the substantive features of experimental interspike interval histograms recorded from real, periodically forced sensory neurons. Our analysis relies on linking this interval sequence to the firing-reset mechanism of real neurons, and illustrates the importance of the noise, without which the substantive features cannot exist, for the transmission of sensory information. C1 UNIV CALIF LOS ALAMOS SCI LAB,CTR NONLINEAR STUDIES,DIV THEORET B213,LOS ALAMOS,NM 87545. USN,CTR OCEAN SYST,SAN DIEGO,CA 92152. UNIV MISSOURI,DEPT PHYS,ST LOUIS,MO 63121. RP LONGTIN, A (reprint author), UNIV CALIF LOS ALAMOS SCI LAB,COMPLEX SYST GRP,LOS ALAMOS,NM 87545, USA. RI Longtin, Andre/D-2443-2009 NR 28 TC 398 Z9 408 U1 2 U2 4 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 0031-9007 J9 PHYS REV LETT JI Phys. Rev. Lett. PD JUL 29 PY 1991 VL 67 IS 5 BP 656 EP 659 DI 10.1103/PhysRevLett.67.656 PG 4 WC Physics, Multidisciplinary SC Physics GA FY505 UT WOS:A1991FY50500034 ER PT J AU SZOKE, A KULANDER, KC BARDSLEY, JN AF SZOKE, A KULANDER, KC BARDSLEY, JN TI SIMPLE CALCULATIONS ON 2-COLOR MULTIPHOTON IONIZATION SO JOURNAL OF PHYSICS B-ATOMIC MOLECULAR AND OPTICAL PHYSICS LA English DT Article ID HARMONIC-GENERATION; LASER FIELD; XENON AB Calculations are performed, using a one-dimensional short-range potential and a simple model of the helium atom, of multiphoton ionization due to the coherent superposition of a laser beam with one of its higher-order harmonics. Variation of the relative phase leads to the enhancement or suppression of ionization and to large asymmetries in the photoelectron angular distribution. RP SZOKE, A (reprint author), UNIV CALIF LAWRENCE LIVERMORE NATL LAB,DIV HIGH TEMP PHYS,LIVERMORE,CA 94550, USA. NR 11 TC 51 Z9 51 U1 1 U2 4 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 JUL 28 PY 1991 VL 24 IS 14 BP 3165 EP 3171 DI 10.1088/0953-4075/24/14/008 PG 7 WC Optics; Physics, Atomic, Molecular & Chemical SC Optics; Physics GA FZ743 UT WOS:A1991FZ74300008 ER PT J AU LUPSKI, JR DEOCALUNA, RM SLAUGENHAUPT, S PENTAO, L GUZZETTA, V TRASK, BJ SAUCEDOCARDENAS, O BARKER, DF KILLIAN, JM GARCIA, CA CHAKRAVARTI, A PATEL, PI AF LUPSKI, JR DEOCALUNA, RM SLAUGENHAUPT, S PENTAO, L GUZZETTA, V TRASK, BJ SAUCEDOCARDENAS, O BARKER, DF KILLIAN, JM GARCIA, CA CHAKRAVARTI, A PATEL, PI TI DNA DUPLICATION ASSOCIATED WITH CHARCOT-MARIE-TOOTH DISEASE TYPE-1A SO CELL LA English DT Article ID NEUROPATHY TYPE-I; MULTILOCUS LINKAGE ANALYSIS; PERICENTROMERIC REGION; INTERSTITIAL DELETION; GEL-ELECTROPHORESIS; HEREDITARY MOTOR; GENETIC-LINKAGE; CHROMOSOME-17; RECEPTOR; LOCUS AB Charcot-Marie-Tooth disease type 1A (CMT1A) was localized by genetic mapping to a 3 cM interval on human chromosome 17p. DNA markers within this interval revealed a duplication that is completely linked and associated with CMT1A. The duplication was demonstrated in affected individuals by the presence of three alleles at a highly polymorphic locus, by dosage differences at RFLP alleles, and by two-color fluorescence in situ hybridization. Pulsed-field gel electrophoresis of genomic DNA from patients of different ethnic origins showed a novel SacII fragment of 500 kb associated with CMT1A. A severely affected CMT1A offspring from a mating between two affected individuals was demonstrated to have this duplication present on each chromosome 17. We have demonstrated that failure to recognize the molecular duplication can lead to misinterpretation of marker genotypes for affected individuals, identification of false recombinants, and incorrect localization of the disease locus. C1 BAYLOR UNIV,DEPT PEDIAT,HOUSTON,TX 77030. BAYLOR UNIV,DEPT NEUROL,HOUSTON,TX 77030. LOUISIANA STATE UNIV,MED CTR,DEPT PATHOL,NEW ORLEANS,LA 70112. BAYLOR UNIV,CTR HUMAN GENOME,HOUSTON,TX 77030. UNIV PITTSBURGH,DEPT HUMAN GENET,PITTSBURGH,PA 15260. UNIV PITTSBURGH,DEPT PSYCHIAT,PITTSBURGH,PA 15260. UNIV CALIF LAWRENCE LIVERMORE NATL LAB,DIV BIOMED SCI,LIVERMORE,CA 94550. UNIV UTAH,SCH MED,DEPT MED INFORMAT,SALT LAKE CITY,UT 84130. LOUISIANA STATE UNIV,MED CTR,DEPT NEUROL,NEW ORLEANS,LA 70112. RP LUPSKI, JR (reprint author), BAYLOR UNIV,INST MOLEC GENET,HOUSTON,TX 77030, USA. FU NHGRI NIH HHS [HG 00344, HG-00256-01]; NICHD NIH HHS [HD00774] NR 62 TC 1004 Z9 1014 U1 2 U2 20 PU CELL PRESS PI CAMBRIDGE PA 1050 MASSACHUSETTES AVE, CIRCULATION DEPT, CAMBRIDGE, MA 02138 SN 0092-8674 J9 CELL JI Cell PD JUL 26 PY 1991 VL 66 IS 2 BP 219 EP 232 DI 10.1016/0092-8674(91)90613-4 PG 14 WC Biochemistry & Molecular Biology; Cell Biology SC Biochemistry & Molecular Biology; Cell Biology GA FY712 UT WOS:A1991FY71200004 PM 1677316 ER PT J AU VERGELDT, FJ KOEHORST, RBM SCHAAFSMA, TJ LAMBRY, JC MARTIN, JL JOHNSON, DG WASIELEWSKI, MR AF VERGELDT, FJ KOEHORST, RBM SCHAAFSMA, TJ LAMBRY, JC MARTIN, JL JOHNSON, DG WASIELEWSKI, MR TI SUBPICOSECOND PHOTOINDUCED ELECTRON-TRANSFER IN WATER-SOLUBLE PORPHYRIN DIMERS SO CHEMICAL PHYSICS LETTERS LA English DT Article ID RHODOPSEUDOMONAS-VIRIDIS; SPIN-RESONANCE; CHLOROPHYLL; PHOTOSYNTHESIS; HETERODIMERS; DERIVATIVES; SPHAEROIDES; MODEL AB Picosecond as well as femtosecond transient absorption measurements have been performed on eight water-soluble heterodimers consisting of combinations of oppositely charged free base and metal porphyrins which have been electrochemically characterized. The ultrafast non-exponential absorption increase, attributed to solvent-controlled, intradimer charge separation, is energy-gap independent. By contrast, the much slower charge recombination is energy-gap dependent. C1 ECOLE POLYTECH,OPT APPL LAB,F-91128 PALAISEAU,FRANCE. ARGONNE NATL LAB,DIV CHEM,ARGONNE,IL 60439. RP VERGELDT, FJ (reprint author), AGR UNIV WAGENINGEN,DEPT MOLEC PHYS,DREIJENLAAN 3,6703 HA WAGENINGEN,NETHERLANDS. RI Vergeldt, Frank/B-6421-2014 NR 35 TC 47 Z9 47 U1 2 U2 9 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 JUL 26 PY 1991 VL 182 IS 2 BP 107 EP 113 DI 10.1016/0009-2614(91)80112-B PG 7 WC Chemistry, Physical; Physics, Atomic, Molecular & Chemical SC Chemistry; Physics GA FZ816 UT WOS:A1991FZ81600004 ER PT J AU CZOK, M KATTI, AM GUIOCHON, G AF CZOK, M KATTI, AM GUIOCHON, G TI EFFECT OF SAMPLE VISCOSITY IN HIGH-PERFORMANCE SIZE-EXCLUSION CHROMATOGRAPHY AND ITS CONTROL SO JOURNAL OF CHROMATOGRAPHY LA English DT Article ID PROTEINS AB When the sample viscosity greatly exceeds that of the mobile phase, flow instabilities occur, which lead to non-uniform flow in the radial direction. This "fingering" effect is usually greater with large-diameter than with micro-bore columns and may have worse effects in size-exclusion chromatography (SEC) than in any other chromatographic mode, as retention is shorter and dilution less important with SEC than with modes where retention is significant. This study suggests ways to reduce this viscosity effect. For example, this effect can be eliminated by controlling the concentration of a suitable mobile-phase additive which allows one to equate the viscosities of the eluent and the sample. Another possibility is to follow the sample with a plug of eluent, 0.3-0.5 column volumes wide, having a slightly higher viscosity than the sample. No spurious peaks are observed, as the plug acts as a wall prohibiting "fingering". C1 UNIV TENNESSEE,DEPT CHEM,KNOXVILLE,TN 37996. OAK RIDGE NATL LAB,DIV ANALYT CHEM,OAK RIDGE,TN 37831. OI Souce, Martin/0000-0002-6627-9660 NR 19 TC 45 Z9 45 U1 0 U2 2 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0021-9673 J9 J CHROMATOGR PD JUL 26 PY 1991 VL 550 IS 1-2 BP 705 EP 719 DI 10.1016/S0021-9673(01)88576-9 PG 15 WC Chemistry, Analytical SC Chemistry GA GB882 UT WOS:A1991GB88200052 ER PT J AU YONKER, CR SMITH, RD AF YONKER, CR SMITH, RD TI SORPTION ISOTHERMS IN SUPERCRITICAL FLUID CHROMATOGRAPHY SO JOURNAL OF CHROMATOGRAPHY LA English DT Review ID STATIONARY-PHASE; CARBON-DIOXIDE; ADSORPTION-ISOTHERMS; SURFACE EXCESS; RETENTION; TEMPERATURE; DENSITY; SILICA; GAS; MODIFIERS AB The continued and growing interest in supercritical fluid chromatography (SFC) has given rise to a need for a better understanding of the solute retention mechanism. One facet of research has aimed at a theoretical description of solute retention using equation of state models based on statistical mechanics and thermodynamic descriptions of the P, V, T relationship for a fluid. A second approach has involved studies of the physico-chemical interaction of the supercritical fluid with the solute molecule and the stationary phase. Solute retention in SFC has been demonstrated to be a dynamic process of intermolecular interactions between the solute and the fluid mobile phase and between the solute and the bonded polymeric stationary phase. This qualitative statement is supported by spectroscopic studies of solvent cluster formation about a solute molecule in a supercritical fluid, partial molar volume studies and isotherm measurements of the fluid in different stationary phases under various conditions in SFC. Progress made to date in determining the sorption isotherms of mobile phase components in SFC is reviewed. RP YONKER, CR (reprint author), PACIFIC NW LAB, DEPT CHEM SCI, CHEM METHODS & SEPARAT GRP, RICHLAND, WA 99352 USA. RI Smith, Richard/J-3664-2012 OI Smith, Richard/0000-0002-2381-2349 NR 42 TC 14 Z9 14 U1 0 U2 6 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0021-9673 J9 J CHROMATOGR PD JUL 26 PY 1991 VL 550 IS 1-2 BP 775 EP 785 DI 10.1016/S0021-9673(01)88581-2 PG 11 WC Chemistry, Analytical SC Chemistry GA GB882 UT WOS:A1991GB88200057 ER PT J AU TAYLOR, JA YEUNG, ES AF TAYLOR, JA YEUNG, ES TI AXIAL-BEAM ABSORBENCY DETECTION FOR CAPILLARY ELECTROPHORESIS SO JOURNAL OF CHROMATOGRAPHY LA English DT Article ID OPEN-TUBULAR CAPILLARY; ZONE ELECTROPHORESIS; ABSORPTION SPECTROMETRY; CHROMATOGRAPHY; CELL; SEPARATION AB A novel approach to absorbance detection has been demonstrated for capillary electrophoresis utilizing an incident light beam directed along the capillary axis. The resulting absorption path length is roughly equal to the width of the sample bands present. This represents a 60-fold improvement in analytical path length over conventional on-column absorbance detectors without any loss of separation efficiency. The method can be used with completely aqueous buffer systems or those containing organic modifiers, and is applicable to both fused-silica and PTFE capillaries. C1 IOWA STATE UNIV SCI & TECHNOL,DEPT CHEM,AMES,IA 50011. RP YEUNG, ES (reprint author), IOWA STATE UNIV SCI & TECHNOL,US DOE,AMES LAB,AMES,IA 50011, USA. NR 16 TC 34 Z9 35 U1 0 U2 1 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0021-9673 J9 J CHROMATOGR PD JUL 26 PY 1991 VL 550 IS 1-2 BP 831 EP 837 DI 10.1016/S0021-9673(01)88586-1 PG 7 WC Chemistry, Analytical SC Chemistry GA GB882 UT WOS:A1991GB88200062 ER PT J AU SHANK, CV AF SHANK, CV TI LBL HELMSMAN SO SCIENCE LA English DT Letter RP SHANK, CV (reprint author), UNIV CALIF BERKELEY LAWRENCE BERKELEY LAB,1 CYCLOTRON RD,BERKELEY,CA 94720, USA. NR 1 TC 0 Z9 0 U1 0 U2 0 PU AMER ASSOC ADVANCEMENT SCIENCE PI WASHINGTON PA 1200 NEW YORK AVE, NW, WASHINGTON, DC 20005 SN 0036-8075 J9 SCIENCE JI Science PD JUL 26 PY 1991 VL 253 IS 5018 BP 366 EP 366 DI 10.1126/science.253.5018.366-b PG 1 WC Multidisciplinary Sciences SC Science & Technology - Other Topics GA FY288 UT WOS:A1991FY28800004 ER PT J AU WIDRIG, CA CHUNG, C PORTER, MD AF WIDRIG, CA CHUNG, C PORTER, MD TI THE ELECTROCHEMICAL DESORPTION OF N-ALKANETHIOL MONOLAYERS FROM POLYCRYSTALLINE AU AND AG ELECTRODES SO JOURNAL OF ELECTROANALYTICAL CHEMISTRY LA English DT Article ID ORGANIZED MOLECULAR ASSEMBLIES; OXIDIZED ALUMINUM SURFACE; SOLID LIQUID INTERFACE; NORMAL-ALKANOIC ACIDS; GOLD ELECTRODES; STRUCTURAL CHARACTERIZATION; ORGANOSULFUR COMPOUNDS; FILMS; ADSORPTION; SILVER AB Monolayers formed at Au and Ag surfaces by the spontaneous adsorption of n-alkanethiols were characterized voltammetrically to examine the chemistry of the ound thiol head group. Electrode reactions that correspond to the oxidative- and reductive-desorption of the adsorbed n-alkanethiol monolayer are reported for the first time. Analysis of the data indicates that upon adsorption at both Au and Ag surfaces the hydrogen of the thiol group is lost and the sulfur atom is oxidized by one electron. Based on the charge required for the reductive-desorption of the monolayer, the surface coverage of the oxidized n-alkanethiol species is 9.3 x 10(-10) mol/cm2 and 7.0 x 10(-10) mol/cm2 on Au and Ag, respectively. The value of the surface coverage at Au is slightly greater than that expected for a closest-packed overlayer commensurate with a Au(111) substrate, whereas the value at Ag is somewhat less than that expected for layers commensurate at any of the low index Ag surface planes. The low apparent coverage observed for Ag electrodes is attributed to a portion of the monolayer being electroinactive at accessible applied voltages. As a probe of the mechanism for monolayer formation, films that were deposited on Ag and Au surfaces from solutions containing sodium n-octadecanethiolate were also characterized. Examination of the resulting layers with infrared reflection spectroscopy and optical ellipsometry indicates that only at Ag substrates were the films deposited from the thiolate solution complete and structurally similar to monolayers formed from n-octadecanethiol solutions. Based on this observation, it is postulated that the thiol hydrogen of the n-alkanethiol molecule participates in the reduction reaction that is concomitant to the thiol oxidation during adsorption on Au, whereas adsorption on Ag proceeds through the reduction of the Ag(I) surface species of the native oxide. A model for the electric double layer at the monolayer-coated-electrode/solution interface is also suggested based on the observed chain-length dependence of both the capacitance and the potential for the reductive desorption. C1 US DOE,AMES LAB,AMES,IA 50011. IOWA STATE UNIV SCI & TECHNOL,DEPT CHEM,AMES,IA 50011. NR 51 TC 948 Z9 956 U1 16 U2 158 PU ELSEVIER SCIENCE SA LAUSANNE PI LAUSANNE 1 PA PO BOX 564, 1001 LAUSANNE 1, SWITZERLAND SN 0022-0728 J9 J ELECTROANAL CHEM JI J. Electroanal. Chem. PD JUL 25 PY 1991 VL 310 IS 1-2 BP 335 EP 359 DI 10.1016/0022-0728(91)85271-P PG 25 WC Chemistry, Analytical; Electrochemistry SC Chemistry; Electrochemistry GA GA710 UT WOS:A1991GA71000025 ER PT J AU RAGHAVACHARI, K ROHLFING, CM AF RAGHAVACHARI, K ROHLFING, CM TI STRUCTURES AND VIBRATIONAL FREQUENCIES OF C60, C70, AND C84 SO JOURNAL OF PHYSICAL CHEMISTRY LA English DT Article ID ICOSAHEDRAL C-60; SYMMETRICAL CLUSTERS; CARBON CLUSTERS; BUCKMINSTERFULLERENE; MOLECULES; SPECTRA; REHYBRIDIZATION; STABILITY; ATOMS; MODES AB The structures and vibrational frequencies of C60, C70, and C84 have been determined with the semiempirical MNDO method. Two highly stable minimum-energy structures have been identified for C84. Of the two, a D6h form, which contains five distinct carbon atoms, is found to be slightly more stable than a T(d) form with four distinct carbons. Both isomers are found to be significantly more stable than either C60 or C70, consistent with the presence of a greater proportion of six-membered rings in C84. An additional structure containing seven-membered rings has also been considered for C84, but is significantly less stable than structures containly only five- and six-membered rings. Finally, the geometries of C60, C70, and the two stable forms of C84 have been completely optimized by using ab initio Hartree-Fock theory with the double-zeta-3-21G basis set. C1 SANDIA NATL LABS,LIVERMORE,CA 94551. RP RAGHAVACHARI, K (reprint author), AT&T BELL LABS,MURRAY HILL,NJ 07974, USA. NR 42 TC 175 Z9 177 U1 0 U2 13 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 SN 0022-3654 J9 J PHYS CHEM-US JI J. Phys. Chem. PD JUL 25 PY 1991 VL 95 IS 15 BP 5768 EP 5773 DI 10.1021/j100168a013 PG 6 WC Chemistry, Physical SC Chemistry GA FY388 UT WOS:A1991FY38800013 ER PT J AU QIN, XZ LIU, A TRIFUNAC, AD KRONGAUZ, VV AF QIN, XZ LIU, A TRIFUNAC, AD KRONGAUZ, VV TI PHOTODISSOCIATION OF HEXAARYLBIIMIDAZOLE .1. TRIPLET-STATE FORMATION SO JOURNAL OF PHYSICAL CHEMISTRY LA English DT Article ID TRIARYLIMIDAZOLYL FREE RADICALS; DIFFUSION AB The mechanism of photodissociation of 2-chlorohexaarylbiimidazole is studied by laser flash photolysis in organic liquids and by EPR methods in polymer and low-molecular-weight organic matrices. It is found that at low temperatures (approximately 10 K) the ultraviolet irradiation produces a triplet hexaarylbiimidazole rather than the radicals. No triplet-state decomposition into radicals is observed, supporting the results of indirect measurements reported by other researchers. At higher temperatures, the radicals formed from the dissociation of the singlet state dominate. This is the first direct observation of the hexaarylbiimidazole triplet reported to date. The results are explained by considering the molecular structure and hexaarylbiimidazole mobility. C1 ARGONNE NATL LAB, DIV CHEM, ARGONNE, IL 60439 USA. DUPONT CO, DEPT IMAGING SYST, EXPTL STN LAB, WILMINGTON, DE 19880 USA. NR 33 TC 50 Z9 50 U1 2 U2 7 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 0022-3654 J9 J PHYS CHEM-US JI J. Phys. Chem. PD JUL 25 PY 1991 VL 95 IS 15 BP 5822 EP 5826 DI 10.1021/j100168a022 PG 5 WC Chemistry, Physical SC Chemistry GA FY388 UT WOS:A1991FY38800022 ER PT J AU BEHRENS, R BULUSU, S AF BEHRENS, R BULUSU, S TI THERMAL-DECOMPOSITION OF ENERGETIC MATERIALS .2. DEUTERIUM-ISOTOPE EFFECTS AND ISOTOPIC SCRAMBLING IN CONDENSED-PHASE DECOMPOSITION OF OCTAHYDRO-1,3,5,7-TETRANITRO-1,3,5,7-TETRAZOCINE SO JOURNAL OF PHYSICAL CHEMISTRY LA English DT Article ID BEAM MASS-SPECTROMETRY; PYROLYSIS PRODUCTS; HMX; 1,3,5,7-TETRANITRO-1,3,5,7-TETRAAZACYCLOOCTANE; 1,3,5-TRINITRO-1,3,5-TRIAZACYCLOHEXANE; RATES; RDX AB The products formed in the thermal decomposition of octahydro-1,3,5,7-tetranitro-1,3,5,7-tetrazocine (HMX) have been traced by using mixtures of different isotopically labeled analogues of HMX. The isotopic analogues of HMX used in the experiments include H-2, C-13, (NO2)-N-15, N-15ring, and O-18. The fraction of isotopic scrambling and the extent of the deuterium kinetic isotope effect (DKIE) are reported for the different thermal decomposition products. Isotopic scrambling is not observed for the N-N bond in N2O and the C-H bonds in CH2O. Only one of the C-N bonds in N-methylformamide (NMFA) undergoes isotopic scrambling. The lack of complete isotopic scrambling of the N-NO bond in 1-nitroso-3,5,7-trinitro-1,3,5,7-tetrazocine (ONTNTA) is shown to imply that some HMX decomposition occurs in the lattice. The behavior of the DKIE in different mixtures of isotopic analogues of HMX suggests that water probably acts as a catalyst in the decomposition. The results demonstrate that decomposition of HMX in the condensed phase has several reaction branches. C1 USA,ARMAMENT RES & DEV COMMAND,DIV ENERGET MAT,DOVER,NJ 07801. RP BEHRENS, R (reprint author), SANDIA NATL LABS,COMBUST RES FACIL,LIVERMORE,CA 94551, USA. NR 22 TC 80 Z9 80 U1 0 U2 5 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 JUL 25 PY 1991 VL 95 IS 15 BP 5838 EP 5845 DI 10.1021/j100168a025 PG 8 WC Chemistry, Physical SC Chemistry GA FY388 UT WOS:A1991FY38800025 ER PT J AU SHIN, KS MICHAEL, JV AF SHIN, KS MICHAEL, JV TI RATE CONSTANTS (296-1700-K) FOR THE REACTIONS C2H+C2H2-]C4H2+H AND C2D+C2D2-]C4D2+D SO JOURNAL OF PHYSICAL CHEMISTRY LA English DT Article ID PHOTOLYSIS-SHOCK-TUBE; RESONANCE IONIZATION SPECTROSCOPY; FLASH-PHOTOLYSIS; TEMPERATURE-RANGE; VINYLIDENE B-3(2); VACUUM-ULTRAVIOLET; ABSOLUTE RATE; BACK-REACTION; EXCITED C2H; ACETYLENE AB Rate constants for the reactions C2H + C2H2 --> C4H2 + H and C2D + C2D2 --> C4D2 + D have been measured over the temperature range 296-1475 and 1226-1700 K, respectively. For the high-temperature experiments, the method was the laser photolysis-shock tube technique (LP-ST); however, for the room-temperature experiments, the laser photolysis-resonance absorption (LP-RA) technique was used. These techniques utilize the atomic resonance absorption spectroscopy (ARAS) method to monitor H or D atom formation. The results for C2H + C2H2 --> C4H2 + H may be represented by the Arrhenius expression k1H = 3.02 x 10(-10) exp(-235 K/T) cm3 molecule-1 s-1 or may be represented by the simple average of all values, k1H = (1.9 +/- 0.8) x 10(-10) cm3 molecule-1 s-1, over the temperature range 296-1475 K. The rate constant for the reaction C2D + C2D2 --> C4D2 + D can be represented by a simple average of the experimental values, k1D = (1.8 +/- 0.5) x 10(-10) cm3 molecule-1 s-1, over the temperature range 1226-1700 K. The primary quantum yield for H atom production from acetylene by single-photon absorption at 193.3 nm has also been determined to be 0.21 +/- 0.04. C1 ARGONNE NATL LAB, DIV CHEM, ARGONNE, IL 60439 USA. RI Michael, Joe/E-3907-2010 NR 61 TC 48 Z9 48 U1 0 U2 1 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 0022-3654 J9 J PHYS CHEM-US JI J. Phys. Chem. PD JUL 25 PY 1991 VL 95 IS 15 BP 5864 EP 5869 DI 10.1021/j100168a029 PG 6 WC Chemistry, Physical SC Chemistry GA FY388 UT WOS:A1991FY38800029 ER PT J AU ZAWODZINSKI, TA NEEMAN, M SILLERUD, LO GOTTESFELD, S AF ZAWODZINSKI, TA NEEMAN, M SILLERUD, LO GOTTESFELD, S TI DETERMINATION OF WATER DIFFUSION-COEFFICIENTS IN PERFLUOROSULFONATE IONOMERIC MEMBRANES SO JOURNAL OF PHYSICAL CHEMISTRY LA English DT Article ID ION-EXCHANGE MEMBRANES; GRADIENT SPIN-ECHO; NAFION MEMBRANES AB Pulsed field gradient spin-echo H-1 NMR measurements of H-1 intradiffusion coefficients at 30-degrees-C in hydrated Nafion membranes are reported. The dependence of the H-1 self-diffusion coefficient on membrane water content was a central part of this investigation. H-1 diffusion coefficients ranged from 0.6 x 10(-6) to 5.8 x 10(-6) cm2/s for the range of membrane water content 2-14 water molecules per sulfonate. The membrane water content was controlled by isopiestic equilibration of the membrane sample with water vapor above aqueous LiCl solutions of well-defined water activities. The dependence of membrane water content on water activity enables us to estimate "chemical diffusion coefficients" from the intradiffusion coefficients measured by NMR. RP ZAWODZINSKI, TA (reprint author), UNIV CALIF LOS ALAMOS SCI LAB,LOS ALAMOS,NM 87545, USA. RI Neeman, Michal/A-8264-2008 OI Neeman, Michal/0000-0002-6296-816X NR 24 TC 731 Z9 738 U1 7 U2 99 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 JUL 25 PY 1991 VL 95 IS 15 BP 6040 EP 6044 DI 10.1021/j100168a060 PG 5 WC Chemistry, Physical SC Chemistry GA FY388 UT WOS:A1991FY38800060 ER PT J AU BARLETT, ML FERGERSON, RW HOFFMANN, GW MARSHALL, JA RAY, L AMANN, JF BONNER, BE MCCLELLAND, JB AF BARLETT, ML FERGERSON, RW HOFFMANN, GW MARSHALL, JA RAY, L AMANN, JF BONNER, BE MCCLELLAND, JB TI INCLUSIVE QUASI-ELASTIC SPIN OBSERVABLES FOR -]P+H-2,C-12 AT 500 MEV SO PHYSICS LETTERS B LA English DT Article ID NUCLEON-NUCLEUS SCATTERING; IMPULSE-APPROXIMATION; ELASTIC-SCATTERING; PROTON-SCATTERING AB Analyzing powers (A(y)) and spin-rotation-depolarization parameters (D(SS), D(SL), D(LS), D(LL), D(NN)) were determined for 500 MeV p --> + H-2 and p --> + C-12 inclusive quasielastic scattering at 10-degrees, 15-degrees, and 20-degrees laboratory scattering angles. The p --> + H-2 data are consistent with the isospin-average of the proton-proton and proton-neutron scattering observables; the p --> + C-12 data are not. A relativi plane wave impulse approximation calculation leads to better agreement with the p --> + C-12 spin-observables. C1 UNIV TEXAS,DEPT PHYS,AUSTIN,TX 78712. UNIV CALIF LOS ALAMOS SCI LAB,LOS ALAMOS,NM 87545. NR 27 TC 1 Z9 1 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 JUL 25 PY 1991 VL 264 IS 1-2 BP 21 EP 25 DI 10.1016/0370-2693(91)90696-N PG 5 WC Astronomy & Astrophysics; Physics, Nuclear; Physics, Particles & Fields SC Astronomy & Astrophysics; Physics GA GB513 UT WOS:A1991GB51300005 ER PT J AU FLYNN, JM HILL, BR AF FLYNN, JM HILL, BR TI B-B-STAR SPLITTING - A TEST OF HEAVY QUARK METHODS SO PHYSICS LETTERS B LA English DT Article ID EFFECTIVE FIELD-THEORY; QUANTUM CHROMODYNAMICS; LIGHT; QCD; APPROXIMATION; CONSTANTS; CONTINUUM; FERMIONS; LATTICE; MESONS AB We determine the one-loop QCD matching between lattice and continuum theories of the chromomagnetic moment operator. The operator is responsible for breaking the degeneracy of B and B* mesons at order 1/m in the static approximation. RP FLYNN, JM (reprint author), FERMI NATL ACCELERATOR LAB,POB 500,BATAVIA,IL 60510, USA. OI Flynn, Jonathan/0000-0002-6280-1677 NR 29 TC 9 Z9 9 U1 0 U2 0 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0370-2693 J9 PHYS LETT B JI Phys. Lett. B PD JUL 25 PY 1991 VL 264 IS 1-2 BP 173 EP 177 DI 10.1016/0370-2693(91)90723-4 PG 5 WC Astronomy & Astrophysics; Physics, Nuclear; Physics, Particles & Fields SC Astronomy & Astrophysics; Physics GA GB513 UT WOS:A1991GB51300032 ER PT J AU WANG, HH KINI, AM SAVALL, BM CARLSON, KD WILLIAMS, JM LATHROP, MW LYKKE, KR PARKER, DH WURZ, P PELLIN, MJ GRUEN, DM WELP, U KWOK, WK FLESHLER, S CRABTREE, GW SCHIRBER, JE OVERMYER, DL AF WANG, HH KINI, AM SAVALL, BM CARLSON, KD WILLIAMS, JM LATHROP, MW LYKKE, KR PARKER, DH WURZ, P PELLIN, MJ GRUEN, DM WELP, U KWOK, WK FLESHLER, S CRABTREE, GW SCHIRBER, JE OVERMYER, DL TI SUPERCONDUCTIVITY AT 28.6-K IN A RUBIDIUM C60 FULLERENE COMPOUND, RBXC60, SYNTHESIZED BY A SOLUTION-PHASE TECHNIQUE SO INORGANIC CHEMISTRY LA English DT Note C1 ARGONNE NATL LAB,DIV CHEM,ARGONNE,IL 60439. UNIV CALIF IRVINE,DEPT CHEM,IRVINE,CA 92717. SANDIA NATL LABS,ALBUQUERQUE,NM 87185. RP WANG, HH (reprint author), ARGONNE NATL LAB,DIV MAT SCI,ARGONNE,IL 60439, USA. RI Pellin, Michael/B-5897-2008; Kini, Aravinda/F-4467-2012 OI Pellin, Michael/0000-0002-8149-9768; NR 5 TC 34 Z9 34 U1 0 U2 9 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 SN 0020-1669 J9 INORG CHEM JI Inorg. Chem. PD JUL 24 PY 1991 VL 30 IS 15 BP 2962 EP 2963 DI 10.1021/ic00015a004 PG 2 WC Chemistry, Inorganic & Nuclear SC Chemistry GA FY270 UT WOS:A1991FY27000004 ER PT J AU FISH, RH KONINGS, MS OBERHAUSEN, KJ FONG, RH YU, WM CHRISTOU, G VINCENT, JB COGGIN, DK BUCHANAN, RM AF FISH, RH KONINGS, MS OBERHAUSEN, KJ FONG, RH YU, WM CHRISTOU, G VINCENT, JB COGGIN, DK BUCHANAN, RM TI BIOMIMETIC OXIDATION STUDIES .5. MECHANISTIC ASPECTS OF ALKANE FUNCTIONALIZATION WITH FE,FE2O, AND FE4O2 COMPLEXES IN THE PRESENCE OF HYDROGEN-PEROXIDE SO INORGANIC CHEMISTRY LA English DT Article ID METHYLOCOCCUS-CAPSULATUS BATH; RESONANCE RAMAN-SPECTROSCOPY; BINUCLEAR IRON CENTER; SATURATED-HYDROCARBONS; METHANE MONOOXYGENASE; RIBONUCLEOTIDE REDUCTASE; OXYGEN-TRANSFER; ALIPHATIC HYDROXYLATION; ALKYL HYDROPEROXIDES; ACTIVATION AB The biomimetic oxidation reactions of a variety of hydrocarbons with iron complexes, Fe2O(OAc)2(bpy)2Cl2 (1), Fe4O2(OAc)7(bpy)2(ClO4) (2), Fe2O(OAc)(tmima)2(ClO4)3 (3) (tmima = tris[(1-methylimidazol-2-yl)methyl]amine), and Fe(ClO4)3.6H2O (4), using H2O2/O2 as the oxidant were studied. Functionalization of cyclohexane gave cyclohexanol (CyOH) and cyclohexanone (CyONE). Complex 4 was the most effective and selective, 15-20 mmol of CyOH, 5-8 mmol of CyONE/mmol of Fe complex, and CyOH/CyONE ratios of approximately 2; however, the pseudo-first-order rate constants for the formation of CyOH and CyONE for 1 and 2 were approximately 1.4-1.6 times greater than those for 4. Complexes 1-3 gave 2-7 and 3-8 mmol of product/mmol of Fe complex, respectively, with CyOH/CyONE ratios of 0.6-1.1. The presence of an oxidizing intermediate was suggested by iodometric titration in the functionalization of cyclohexane with complexes 1-4 and H2O2. This intermediate was isolated from the reaction mixture and identified by C-13 NMR as cyclohexyl hydroperoxide (CyOOH) as compared to an independently prepared sample. The decomposition of CyOOH by 1-4 and H2O2 gave CyOH/CyONE ratios of 0.7, 0.9, 0.7, and 2.8, respectively, in the ranges observed in the actual cyclohexane oxidation reactions. These hydrocarbon oxidation reactions were also inhibited by 2,4,6-tri-tert-butylphenol. Reactions run under a sweep of argon gave mmol of product/mmol of Fe complex 0-31% of the normal values. These results are consistent with a free-radical chain mechanism in which an initially formed cyclohexyl radical is trapped by oxygen gas to give a cyclohexyl peroxyl radical, which abstracts a hydrogen atom to give CyOOH and carry the chain. The tertiary hydrogen of adamantane was selectively abstracted with complexes 1-4 to obtain normalized C3/C2 values of 3.5, 3.3, 3.4, and 5.6, respectively. Toluene was transformed to a mixture of benzyl alcohol, benzaldehyde, and o; m; and p-cresols with benzylic/aromatic activation ratios of 3.4, 4.2, 0.9, and 20, respectively, and indicate that hydroxyl radicals (aromatic C-H functionalization) may also participate. Functionalization of methane, ethane, and propane was also observed. C1 INDIANA UNIV,DEPT CHEM,BLOOMINGTON,IN 47405. UNIV LOUISVILLE,DEPT CHEM,LOUISVILLE,KY 40292. RP FISH, RH (reprint author), UNIV CALIF BERKELEY LAWRENCE BERKELEY LAB,BERKELEY,CA 94720, USA. RI Christou, George /A-3072-2014 NR 60 TC 124 Z9 127 U1 2 U2 17 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 SN 0020-1669 J9 INORG CHEM JI Inorg. Chem. PD JUL 24 PY 1991 VL 30 IS 15 BP 3002 EP 3006 DI 10.1021/ic00015a012 PG 5 WC Chemistry, Inorganic & Nuclear SC Chemistry GA FY270 UT WOS:A1991FY27000012 ER PT J AU STEVENS, RC RICCI, JS KOETZLE, TF HERRMANN, WA AF STEVENS, RC RICCI, JS KOETZLE, TF HERRMANN, WA TI TRANSITION-METAL METHYLENE COMPLEXES .67. NEUTRON-DIFFRACTION STUDY OF MU-PROPYLIDENE(2)-BIS[CARBONYL(ETA-5-PENTAMETHYLCYCLOPENTADIENYL)RHODIUM -(RH-RH)], [MU-C(CH3)2][(ETA-5-C5(CH3)5)RH(CO)]2, AT 20-K SO JOURNAL OF ORGANOMETALLIC CHEMISTRY LA English DT Article ID FISCHER-TROPSCH SYNTHESIS; CARBENE ADDITION; DOUBLE-BOND; CONSTITUTION; BRIDGE AB The title compound. 3, is prepared by reaction of [(mu-CO)(eta-5-C5Me5)Rh]2, 1, with N2 = CMe2, 2. A neutron diffraction study of the structure of 3 at 20 K reveals a normal dimeric structure with approximate C2 molecular symmetry and a Rh-Rh single bond (2.66 angstrom). The geometry of the bridging propylidene ligand shows no exceptional features that might be connected with the unusual photolysis behavior of 3, wherein a diamagnetic material with complex H-1- and C-13-NMR spectra is formed. Crystallographic data: a 16.856(3), b 15.978(5), c 18.730(11) angstrom, beta-107.50(2)-degrees, Z = 8, space group P2(1)/c (No. 14), R(F2) = 0.141 for 8514 neutron data. C1 BROOKHAVEN NATL LAB, DEPT CHEM, UPTON, NY 11973 USA. TECH UNIV MUNICH, INST ANORGAN CHEM, W-8046 GARCHING, GERMANY. RP STEVENS, RC (reprint author), UNIV SO MAINE, DEPT CHEM, PORTLAND, ME 04103 USA. RI Herrmann, Wolfgang/A-3588-2010; Stevens, Raymond/K-7272-2015 OI Stevens, Raymond/0000-0002-4522-8725 NR 35 TC 0 Z9 0 U1 0 U2 0 PU ELSEVIER SCIENCE SA PI LAUSANNE PA PO BOX 564, 1001 LAUSANNE, SWITZERLAND SN 0022-328X EI 1872-8561 J9 J ORGANOMET CHEM JI J. Organomet. Chem. PD JUL 23 PY 1991 VL 412 IS 3 BP 425 EP 434 DI 10.1016/0022-328X(91)86087-7 PG 10 WC Chemistry, Inorganic & Nuclear; Chemistry, Organic SC Chemistry GA FZ887 UT WOS:A1991FZ88700014 ER PT J AU HAWORTH, M ADLER, R ANDERSON, B CONNAUGHTON, M DUNGAN, W ENNS, J METZ, J PELLETIER, P PLATT, R POLACO, J RUPP, R THODE, L VOSS, D AF HAWORTH, M ADLER, R ANDERSON, B CONNAUGHTON, M DUNGAN, W ENNS, J METZ, J PELLETIER, P PLATT, R POLACO, J RUPP, R THODE, L VOSS, D TI EXPERIMENTAL-OBSERVATION OF 2 MICROWAVE-RADIATION MECHANISMS WITH WIDELY SEPARATED FREQUENCIES DURING THE OUTPUT PULSE OF A HIGH-VOLTAGE VIRTUAL CATHODE OSCILLATOR SO APPLIED PHYSICS LETTERS LA English DT Article AB Results from two 4 MV, 100 kA coaxial magnetically insulated transmission line virtual cathode oscillator experiments are presented. In both experiments, two distinct microwave pulses with vastly different frequencies were generated during the beam current pulse. The first, lower frequency pulse was found to be produced by an electron reflexing process, while the second, higher frequency pulse was due to the virtual cathode oscillation mechanism. C1 SCI APPLICAT INT CORP,ALBUQUERQUE,NM 87106. N STAR RES CORP,ALBUQUERQUE,NM 87108. ROCKWELL INT CORP,POWER SERV,ALBUQUERQUE,NM 87106. UNIV CALIF LOS ALAMOS SCI LAB,LOS ALAMOS,NM 87545. VOSS SCI,ALBUQUERQUE,NM 87108. RP HAWORTH, M (reprint author), PHILLIPS LAB,KIRTLAND AFB,ALBUQUERQUE,NM 87117, USA. NR 11 TC 14 Z9 14 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 JUL 22 PY 1991 VL 59 IS 4 BP 408 EP 410 DI 10.1063/1.105446 PG 3 WC Physics, Applied SC Physics GA FX626 UT WOS:A1991FX62600010 ER PT J AU HAYNES, TE HOLLAND, OW AF HAYNES, TE HOLLAND, OW TI COMPARATIVE-STUDY OF IMPLANTATION-INDUCED DAMAGE IN GAAS AND GE - TEMPERATURE AND FLUX DEPENDENCE SO APPLIED PHYSICS LETTERS LA English DT Article ID DOSE-RATE AB Damage accumulation during ion implantation of 100 keV Si+ into GaAs and Ge has been investigated. A comparison is made of the amount of damage created in GaAs and Ge and its dependence on dose, temperature, and dose rate. General similarities are observed in the dependence of damage in the two materials on dose and temperature. Both materials exhibit a well-defined transition temperature above which the damage decreases dramatically. This transition occurs near room temperature in GaAs and approximately 112-degrees-C higher in Ge. Furthermore, a strong dose-rate effect on damage growth is demonstrated in both Ge and GaAs near their respective transition temperatures. The temperature dependence of the damage yield in both materials is compared to that given by the model of Morehead and Crowder [Rad. Eff. 6, 27 (1970)] for a range of ion doses. RP HAYNES, TE (reprint author), OAK RIDGE NATL LAB,DIV SOLID STATE,OAK RIDGE,TN 37831, USA. RI Haynes, Tony/P-8932-2015 OI Haynes, Tony/0000-0003-2871-4745 NR 10 TC 64 Z9 64 U1 1 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 JUL 22 PY 1991 VL 59 IS 4 BP 452 EP 454 DI 10.1063/1.105460 PG 3 WC Physics, Applied SC Physics GA FX626 UT WOS:A1991FX62600025 ER PT J AU MANSFIELD, KF THEODOROU, DN AF MANSFIELD, KF THEODOROU, DN TI ATOMISTIC SIMULATION OF A GLASSY POLYMER GRAPHITE INTERFACE SO MACROMOLECULES LA English DT Article ID MONTE-CARLO SIMULATION; MOLECULAR-DYNAMICS SIMULATION; VARIABLE-DENSITY MODEL; COMPUTER-SIMULATION; ADSORBED HYDROCARBONS; LOW-TEMPERATURE; BASAL-PLANE; SURFACE; LIQUID; CHAINS AB A computer simulation technique has been developed that is capable of probing the interface between an amorphous glassy polymer and a crystalline solid substrate in atomistic detail. The interface between bulk glassy atactic polypropylene and a graphite basal plane is used as a test case. The method requires the generation of a set of static model microstates that are in detailed mechanical equilibrium, each characterized by two-dimensional periodic boundary conditions and consisting of multiple chains of polymer sandwiched between two semiinfinite solid phases. To obtain a static model microstate, an initial guess microstate is first generated by a Monte Carlo procedure based on the rotational isomeric state model with corrections for long-range interactions. Subsequently, the total potential energy is minimized with respect to all microscopic degrees of freedom. From such a set of static model microstates, we have predicted the internal energy contribution to interfacial thermodynamic properties, as well as the local structural features. A quantitative estimate for the work of adhesion between atactic polypropylene and graphite has been obtained, which agrees well with experiment. The distribution of local internal stresses confirms that microstates are mechanically isotropic in their middle region (far from the solid surfaces), which is indistinguishable from unperturbed bulk polymer. The local structure of the polymer lying within 10 angstrom of a graphite surface is found to be different in many ways from that of the corresponding bulk. Near the solid, the local polymer density profile displays a maximum, the backbone bonds of chains develop considerable orientation parallel to the solid surface, and the usually perferred trans rotational state is suppressed. Adsorbed pendant hydrogens of the polymer concentrate preferentially on top of the centers of the hexagons in the graphite honeycomb. The polymer structure has been explored at the level of entire chains as well. The chain center of mass distribution displays a maximum approximately 1 unperturbed root-mean-squared radius of gyration away from each solid surface. Chains orient with their longest dimension parallel to the graphite phases. The intrinsic shape of the chain segment clouds, as characterized by spans and principal moments of inertia, is found not to be a strong function of position relative to the interface. All polymer/solid results presented have been screened for possible system size effects and compared to the corresponding results from a recent computer simulation of the free surface of glassy atactic polypropylene. C1 UNIV CALIF BERKELEY,DEPT CHEM ENGN,BERKELEY,CA 94720. UNIV CALIF BERKELEY LAWRENCE BERKELEY LAB,CTR ADV MAT,BERKELEY,CA 94720. OI Theodorou, Doros/0000-0002-4763-9739 NR 81 TC 106 Z9 106 U1 1 U2 27 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 SN 0024-9297 J9 MACROMOLECULES JI Macromolecules PD JUL 22 PY 1991 VL 24 IS 15 BP 4295 EP 4309 DI 10.1021/ma00015a011 PG 15 WC Polymer Science SC Polymer Science GA FY047 UT WOS:A1991FY04700011 ER PT J AU HU, Y LAMBERT, SM SOANE, DS PRAUSNITZ, JM AF HU, Y LAMBERT, SM SOANE, DS PRAUSNITZ, JM TI DOUBLE-LATTICE MODEL FOR BINARY POLYMER-SOLUTIONS SO MACROMOLECULES LA English DT Article ID LIQUID PHASE-SEPARATION; THERMODYNAMICS; SYSTEMS; POLY(DIMETHYLSILOXANE); CYCLOHEXANE; SOLVENT AB Freed's lattice-field theory provides a basis for a double-lattice model for the Helmholz energy of mixing for binary polymer solutions. When Freed's series-expansion terms for the simple Ising lattice and for the Flory-Huggins lattice with r1 = 1 and r2 = 100 are revised slightly, predicted liquid-liquid coexistence curves are in excellent agreement with those calculated from Scesney's Pade-approximant coefficients and from computer simulation results by Madden, Pesci, and Freed; here r1 and r2 are the numbers of sites required by molecule 1 and molecule 2, respectively. For real systems, the interchange energy (epsilon/k) and r2 are adjusted to fit the experimental concentration dependence of the Flory-Huggins parameter chi determined by vapor sorption, osmotic pressure, light scattering, or sedimentation. To account for highly oriented interactions between segments, a secondary lattice is introduced. This secondary lattice requires an additional parameter (delta-epsilon/k) related to the energy of the oriented interaction and one empirical parameter c10. With the double-lattice theory, coexistence curves can be reproduced for systems having an upper critical solution temperature (UCST), a lower critical solution temperature (LCST), or a miscibility loop with both UCST and LCST. C1 UNIV CALIF BERKELEY, DEPT CHEM ENGN, BERKELEY, CA 94720 USA. UNIV CALIF BERKELEY LAWRENCE BERKELEY LAB, DIV CHEM SCI, BERKELEY, CA 94720 USA. NR 36 TC 117 Z9 128 U1 2 U2 27 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 0024-9297 EI 1520-5835 J9 MACROMOLECULES JI Macromolecules PD JUL 22 PY 1991 VL 24 IS 15 BP 4356 EP 4363 DI 10.1021/ma00015a017 PG 8 WC Polymer Science SC Polymer Science GA FY047 UT WOS:A1991FY04700017 ER PT J AU BAE, YC LAMBERT, SM SOANE, DS PRAUSNITZ, JM AF BAE, YC LAMBERT, SM SOANE, DS PRAUSNITZ, JM TI CLOUD-POINT CURVES OF POLYMER-SOLUTIONS FROM THERMOOPTIC MEASUREMENTS SO MACROMOLECULES LA English DT Article ID CRITICAL SOLUTION TEMPERATURES; INDUCED CRITICAL SCATTERING AB Thermooptical analysis (TOA) provides a simple, rapid, and reliable experimental method to determine cloud-point curves of binary polymer/solvent systems. Phase diagrams have been obtained for different molecular weights of polystyrene in cyclohexane, methylacetate, ethylacetate, and tert-butylacetate and for poly(ethylene glycol) in water. Polystyrene solutions exhibit both upper and lower critical solution temperatures, while aqueous poly(ethylene glycol) solutions give closed-loop phase diagrams. The TOA apparatus described here uses very small samples (0.02 cm3); for a binary system, upper and lower cloud-point curves can easily be obtained in approximately 8 h. C1 UNIV CALIF BERKELEY,DEPT CHEM ENGN,BERKELEY,CA 94720. UNIV CALIF BERKELEY LAWRENCE BERKELEY LAB,DIV CHEM SCI,BERKELEY,CA 94720. NR 27 TC 174 Z9 175 U1 1 U2 37 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 SN 0024-9297 J9 MACROMOLECULES JI Macromolecules PD JUL 22 PY 1991 VL 24 IS 15 BP 4403 EP 4407 DI 10.1021/ma00015a024 PG 5 WC Polymer Science SC Polymer Science GA FY047 UT WOS:A1991FY04700024 ER PT J AU FEIBELMAN, PJ AF FEIBELMAN, PJ TI ORIENTATION DEPENDENCE OF THE HYDROGEN MOLECULES INTERACTION WITH RH(001) SO PHYSICAL REVIEW LETTERS LA English DT Article ID ELECTRONIC-STRUCTURE CALCULATIONS; METAL-SURFACES; H-2; DISSOCIATION; ADSORPTION; PSEUDOPOTENTIALS; RELAXATION; DESORPTION; RH(100) AB First-principles calculational results, that conflict with conventional wisdom, are reported for the orientation dependence of the energy of H-2, a few bohrs above a Rh(001) surface. In geometric configurations near the saddle point where H-Rh bonds begin to form, the favored molecular axis orientation is along a <100> direction, corresponding to the attraction of each H atom to a twofold bridge site. This is true even though the final destinations of the H atoms are fourfold hollows, and even though the <100> orientation corresponds to relatively low symmetry, i.e., C(s) rather than C2v. RP FEIBELMAN, PJ (reprint author), SANDIA NATL LABS,ALBUQUERQUE,NM 87185, USA. NR 21 TC 60 Z9 60 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 JUL 22 PY 1991 VL 67 IS 4 BP 461 EP 464 DI 10.1103/PhysRevLett.67.461 PG 4 WC Physics, Multidisciplinary SC Physics GA FX425 UT WOS:A1991FX42500014 ER PT J AU BEUHLER, RJ CHU, YY FRIEDLANDER, G FRIEDMAN, L ALESSI, JG LODESTRO, V THOMAS, JP AF BEUHLER, RJ CHU, YY FRIEDLANDER, G FRIEDMAN, L ALESSI, JG LODESTRO, V THOMAS, JP TI CLUSTER-IMPACT FUSION - TIME-OF-FLIGHT EXPERIMENTS SO PHYSICAL REVIEW LETTERS LA English DT Article ID SURFACES AB Time-of-flight cluster-impact fusion studies were carried out by pulsing low-velocity beams. Time-of-flight mass spectra and experiments in which the production of fusion protons was correlated with the arrival times of the cluster ions at the target show that low-molecular-weight ions containing oxygen (i.e., D2O+, D3O+) cannot be responsible for observed fusion events. C1 BROOKHAVEN NATL LAB,DEPT ALTERNATING GRADIENT SYNCHROTRON,UPTON,NY 11973. UNIV LYON 1,CNRS,INST NATL PHYS NUCL & PHYS PARTICULES,INST PHYS NUCL LYON,F-69622 VILLEURBANNE,FRANCE. RP BEUHLER, RJ (reprint author), BROOKHAVEN NATL LAB,DEPT CHEM,UPTON,NY 11973, USA. NR 8 TC 22 Z9 25 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 JUL 22 PY 1991 VL 67 IS 4 BP 473 EP 476 DI 10.1103/PhysRevLett.67.473 PG 4 WC Physics, Multidisciplinary SC Physics GA FX425 UT WOS:A1991FX42500017 ER PT J AU GIBBONS, JP ELSTON, SB KIMURA, K DESERIO, R SELLIN, IA BURGDORFER, J GRANDIN, JP CASSIMI, A HUSSON, X LILJEBY, L DRUETTA, M AF GIBBONS, JP ELSTON, SB KIMURA, K DESERIO, R SELLIN, IA BURGDORFER, J GRANDIN, JP CASSIMI, A HUSSON, X LILJEBY, L DRUETTA, M TI OBSERVATION OF RAPID EVOLUTION OF CONVOY ELECTRON ANGULAR-DISTRIBUTIONS SO PHYSICAL REVIEW LETTERS LA English DT Article ID IONS; CONTINUUM; CAPTURE; EXCITATION; IONIZATION; SOLIDS; ATOMS AB We present results of doubly differential cross-section measurements for production of convoy electrons from 36-MeV/u Ar ions in thin amorphous carbon targets. Comparison of convoy emission distributions as a function of target thickness reveals rapid evolution of component multipole strengths. Thin-target results are compared with binary ion-atom electron-loss-to-the-continuum predictions. A quantitative model of the multipole evolution bridging the transition from the single- to the plural-collision regime is presented which demonstrates significant competition between one-step and multistep production mechanisms. C1 OAK RIDGE NATL LAB,OAK RIDGE,TN 37831. GRAND ACCELERATEUR NATL IONS LOURDS,CTR INTERDISCIPLINAIRE RECH IONS LOURDS,F-14040 CAEN,FRANCE. MANNE SIEGBAHN INST PHYS,S-10405 STOCKHOLM,SWEDEN. UNIV ST ETIENNE,TRAITEMENT SIGNAL & INSTRUMENTAT LAB,F-42023 ST ETIENNE,FRANCE. ISMRA UNIV,SPECT ATOM LAB,F-14050 CAEN,FRANCE. RP GIBBONS, JP (reprint author), UNIV TENNESSEE,DEPT PHYS,KNOXVILLE,TN 37996, USA. RI Cassimi, Amine/J-9165-2014 OI Cassimi, Amine/0000-0002-3367-4066 NR 21 TC 18 Z9 18 U1 1 U2 3 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 0031-9007 J9 PHYS REV LETT JI Phys. Rev. Lett. PD JUL 22 PY 1991 VL 67 IS 4 BP 481 EP 484 DI 10.1103/PhysRevLett.67.481 PG 4 WC Physics, Multidisciplinary SC Physics GA FX425 UT WOS:A1991FX42500019 ER PT J AU BUSSMANNHOLDER, A MIGLIORI, A FISK, Z SARRAO, JL LEISURE, RG CHEONG, SW AF BUSSMANNHOLDER, A MIGLIORI, A FISK, Z SARRAO, JL LEISURE, RG CHEONG, SW TI IMPORTANCE OF STRUCTURAL INSTABILITY TO HIGH-TEMPERATURE SUPERCONDUCTIVITY SO PHYSICAL REVIEW LETTERS LA English DT Article ID HIGH-TC SUPERCONDUCTIVITY; ELASTIC-CONSTANTS; FERROELECTRICITY; POLARIZABILITY; LA2-XSRXCUO4; EXCITATIONS; PEROVSKITE; CRYSTALS; LA2CUO4; SYSTEM AB The orthorhombic-tetragonal structural phase transition of La(2-x)Sr(x)CuO4 is quantitatively analyzed as a function of composition x within an anharmonic electron-phonon interaction model. The correct temperature dependence of the soft mode and the elastic constant C66 is obtained. The double-well potential in the electron-phonon interaction is derived self-consistently and found to vary strongly with x. In the vicinity of the superconducting transition temperature T(c) electron-two-phonon interactions dominate the harmonic ones which may explain the high T(c)'s observed. C1 UNIV BAYREUTH,W-8550 BAYREUTH,GERMANY. UNIV CALIF LOS ALAMOS SCI LAB,LOS ALAMOS,NM 87545. AT&T BELL LABS,MURRAY HILL,NJ 07974. COLORADO STATE UNIV,DEPT PHYS,FT COLLINS,CO 80523. RP BUSSMANNHOLDER, A (reprint author), MAX PLANCK INST FESTKORPERFORSCH,HEISENBERGSTR 1,W-7000 STUTTGART 80,GERMANY. NR 29 TC 38 Z9 38 U1 0 U2 5 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 0031-9007 J9 PHYS REV LETT JI Phys. Rev. Lett. PD JUL 22 PY 1991 VL 67 IS 4 BP 512 EP 515 DI 10.1103/PhysRevLett.67.512 PG 4 WC Physics, Multidisciplinary SC Physics GA FX425 UT WOS:A1991FX42500027 ER PT J AU SOKOL, PE SILVER, RN SOSNICK, TR SNOW, WM AF SOKOL, PE SILVER, RN SOSNICK, TR SNOW, WM TI FINAL-STATE EFFECTS ON THE DEEP-INELASTIC RESPONSE OF LIQUID-HE-4 - COMMENT SO PHYSICAL REVIEW LETTERS LA English DT Letter ID NEUTRON-SCATTERING; MOMENTUM DISTRIBUTIONS C1 UNIV CALIF LOS ALAMOS SCI LAB,DIV THEORET,LOS ALAMOS,NM 87545. UNIV CALIF LOS ALAMOS SCI LAB,MANUEL LUJAN JR NEUTRON SCATTERING CTR,LOS ALAMOS,NM 87545. UNIV CALIF LOS ALAMOS SCI LAB,DIV LIFE SCI,LOS ALAMOS,NM 87545. NATL INST STAND & TECHNOL,DIV QUANTUM METROL,GAITHERSBURG,MD 20899. RP SOKOL, PE (reprint author), PENN STATE UNIV,DEPT PHYS,UNIVERSITY PK,PA 16802, USA. NR 10 TC 0 Z9 0 U1 0 U2 2 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 0031-9007 J9 PHYS REV LETT JI Phys. Rev. Lett. PD JUL 22 PY 1991 VL 67 IS 4 BP 524 EP 524 DI 10.1103/PhysRevLett.67.524 PG 1 WC Physics, Multidisciplinary SC Physics GA FX425 UT WOS:A1991FX42500030 ER PT J AU MACLAUGHLIN, DE HAMMEL, PC VITHAYATHIL, JP CANFIELD, PC FISK, Z HEFFNER, RH REYES, AP THOMPSON, JD CHEONG, SW AF MACLAUGHLIN, DE HAMMEL, PC VITHAYATHIL, JP CANFIELD, PC FISK, Z HEFFNER, RH REYES, AP THOMPSON, JD CHEONG, SW TI ORDER-DISORDER STRUCTURAL PHASE-TRANSITION IN LA2-XSRXCU4+DELTA AT 150-K - COMMENT SO PHYSICAL REVIEW LETTERS LA English DT Letter ID LA2CUO4 C1 UNIV CALIF LOS ALAMOS SCI LAB,LOS ALAMOS,NM 87545. RP MACLAUGHLIN, DE (reprint author), UNIV CALIF RIVERSIDE,RIVERSIDE,CA 92521, USA. RI Canfield, Paul/H-2698-2014; Hammel, P Chris/O-4845-2014 OI Hammel, P Chris/0000-0002-4138-4798 NR 5 TC 1 Z9 1 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 JUL 22 PY 1991 VL 67 IS 4 BP 525 EP 525 DI 10.1103/PhysRevLett.67.525 PG 1 WC Physics, Multidisciplinary SC Physics GA FX425 UT WOS:A1991FX42500031 ER PT J AU CAMERON, R CANTATORE, G MELISSINOS, AC SEMERTZIDIS, Y HALAMA, H LAZARUS, D PRODELL, A NEZRICK, F MICOSSI, P RIZZO, C RUOSO, G ZAVATTINI, E AF CAMERON, R CANTATORE, G MELISSINOS, AC SEMERTZIDIS, Y HALAMA, H LAZARUS, D PRODELL, A NEZRICK, F MICOSSI, P RIZZO, C RUOSO, G ZAVATTINI, E TI 1ST MEASUREMENT OF THE MAGNETIC BIREFRINGENCE OF HELIUM GAS SO PHYSICS LETTERS A LA English DT Article ID HYPERPOLARIZABILITY; PARTICLES AB Using a sensitive ellipsometer we have measured the Cotton-Mouton constant of helium at 514.5 nm. We have found that, at 1 atm and 0-degrees-C, C(CM)(He) = (3.5 +/- 0.7) x 10(-20) G -2 cm-1. Our experimental value is compatible within the errors with previous theoretical calculations. C1 DIPARTIMENTO FIS,VIA VALERIO 2,I-34127 TRIESTE,ITALY. UNIV ROCHESTER,DEPT PHYS & ASTRON,ROCHESTER,NY 14627. BROOKHAVEN NATL LAB,UPTON,NY 11973. FERMI NATL ACCELERATOR LAB,BATAVIA,IL 60516. IST NAZL FIS NUCL,TRIESTE,ITALY. RI Semertzidis, Yannis K./N-1002-2013; Ruoso, Giuseppe/G-3075-2015 OI Ruoso, Giuseppe/0000-0001-8140-9382 NR 11 TC 29 Z9 29 U1 1 U2 6 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0375-9601 J9 PHYS LETT A JI Phys. Lett. A PD JUL 22 PY 1991 VL 157 IS 2-3 BP 125 EP 128 DI 10.1016/0375-9601(91)90083-K PG 4 WC Physics, Multidisciplinary SC Physics GA FZ521 UT WOS:A1991FZ52100008 ER PT J AU LUKE, GM LE, LP STERNLIEB, BJ WU, WD UEMURA, YJ BREWER, JH KADONO, R KIEFL, RF KREITZMAN, SR RISEMAN, TM DALICHAOUCH, Y LEE, BW MAPLE, MB SEAMAN, CL ARMSTRONG, PE ELLIS, RW FISK, Z SMITH, JL AF LUKE, GM LE, LP STERNLIEB, BJ WU, WD UEMURA, YJ BREWER, JH KADONO, R KIEFL, RF KREITZMAN, SR RISEMAN, TM DALICHAOUCH, Y LEE, BW MAPLE, MB SEAMAN, CL ARMSTRONG, PE ELLIS, RW FISK, Z SMITH, JL TI POSITIVE MUON KNIGHT-SHIFT AND SPIN RELAXATION IN HEAVY FERMION SUPERCONDUCTORS UPT3 AND UBE13 SO PHYSICS LETTERS A LA English DT Article ID MAGNETIC-FIELD PENETRATION; TEMPERATURE-DEPENDENCE; PHASE-DIAGRAM; DEPTH; ORDER; (U,TH)BE13; ROTATION AB We report muon spin rotation/relaxation (mu-SR) measurements of the heavy fermion superconductors UBe13 and UPt3. In both materials we find that the muon Knight shift is unchanged in the superconducting state. consistent with odd-parity pairing (such as p-wave). The magnetic field penetration depths in UPt3 and UBe13 are extremely long, greater than 10000 angstrom. We find no evidence of a magnetic transition in UBe13 below 10 K. C1 UNIV BRITISH COLUMBIA,DEPT PHYS,VANCOUVER V6T 2A3,BC,CANADA. UNIV CALIF SAN DIEGO,DEPT PHYS,LA JOLLA,CA 92093. UNIV CALIF SAN DIEGO,INST PURE & APPL PHYS SCI,LA JOLLA,CA 92093. UNIV CALIF LOS ALAMOS SCI LAB,LOS ALAMOS,NM 87545. RP LUKE, GM (reprint author), COLUMBIA UNIV,DEPT PHYS,538 W 120TH ST,NEW YORK,NY 10027, USA. RI Luke, Graeme/A-9094-2010; OI Luke, Graeme/0000-0003-4762-1173; Brewer, Jesse H./0000-0002-8211-1235 NR 25 TC 37 Z9 37 U1 0 U2 1 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0375-9601 J9 PHYS LETT A JI Phys. Lett. A PD JUL 22 PY 1991 VL 157 IS 2-3 BP 173 EP 177 DI 10.1016/0375-9601(91)90094-O PG 5 WC Physics, Multidisciplinary SC Physics GA FZ521 UT WOS:A1991FZ52100019 ER PT J AU NORTHRUP, MA KULP, TJ ANGEL, SM AF NORTHRUP, MA KULP, TJ ANGEL, SM TI FLUORESCENT PARTICLE IMAGE VELOCIMETRY - APPLICATION TO FLOW MEASUREMENT IN REFRACTIVE INDEX-MATCHED POROUS-MEDIA SO APPLIED OPTICS LA English DT Article DE PARTICLE IMAGE VELOCIMETRY; PIV; FLUORESCENCE IMAGING; POROUS MEDIA FLOW; REFRACTIVE INDEX MATCHING ID VELOCITY-FIELD MEASUREMENTS; SPECKLE PHOTOGRAPHY; FLUID; FRINGES AB This paper presents results in which particle image velocimetry (PIV) is used in conjunction with refractive index matching to measure fluid flow velocities within complex, multiphase systems. This application required the adaptation of PIV for use with fluorescent, rather than scattering, seed particles; we refer to the technique as fluorescent PIV (FPIV). We applied index-matched FPIV to the measurement of low flow velocities (tens of microns per second) at high spatial resolution (tens of microns) in a porous medium. We produced clear images of flowing particles in heterogeneous porous media and obtained reliable velocity vectors by a point-by-point interrogation of these images. We also found evidence of the intrapore mixing of porous media flow. RP NORTHRUP, MA (reprint author), UNIV CALIF LAWRENCE LIVERMORE NATL LAB,DIV ENVIRONM SCI,POB 5507,LIVERMORE,CA 94550, USA. NR 25 TC 30 Z9 30 U1 1 U2 9 PU OPTICAL SOC AMER PI WASHINGTON PA 2010 MASSACHUSETTS AVE NW, WASHINGTON, DC 20036 SN 0003-6935 J9 APPL OPTICS JI Appl. Optics PD JUL 20 PY 1991 VL 30 IS 21 BP 3034 EP 3040 PG 7 WC Optics SC Optics GA FX920 UT WOS:A1991FX92000023 PM 20706352 ER PT J AU QUIGLEY, GP WEBSTER, RB CARAMANA, EJ MORSE, RL YORK, GW AF QUIGLEY, GP WEBSTER, RB CARAMANA, EJ MORSE, RL YORK, GW TI CLOUD HOLE BORING WITH LONG PULSE CO2-LASERS - THEORY AND EXPERIMENT SO APPLIED OPTICS LA English DT Article DE CLOUD CLEARING; CLOUD HOLE-BORING; LASER DROPLET INTERACTIONS; LONG PULSE CO2 LASERS ID CO2-LASER PULSE; FOG; TRANSMISSION AB Chemically generated CO2 laser pulses at 10.6-mu-m have been used to clear a 5-cm diameter hole through a stratus-like cloud in a laboratory cloud chamber. The results show that 100% clearing can be achieved. The mechanism is shown to be droplet shattering followed by evaporation. In the experimental conditions, the channel closure is effected by turbulent mixing and droplet recondensation. RP QUIGLEY, GP (reprint author), UNIV CALIF LOS ALAMOS SCI LAB,LOS ALAMOS,NM 87545, USA. NR 16 TC 1 Z9 1 U1 1 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 JUL 20 PY 1991 VL 30 IS 21 BP 3041 EP 3046 PG 6 WC Optics SC Optics GA FX920 UT WOS:A1991FX92000024 PM 20706353 ER PT J AU KOENIGSBERGER, G MOFFAT, AFJ AUER, LH AF KOENIGSBERGER, G MOFFAT, AFJ AUER, LH TI ULTRAVIOLET VARIABILITY OF THE MASSIVE W-R BINARY-SYSTEM HDE-311884 = WR-47 SO ASTROPHYSICAL JOURNAL LA English DT Article DE STARS, BINARIES; STARS, INDIVIDUAL (HDE-311884); STARS, WOLF-RAYET; ULTRAVIOLET, SPECTRA ID WOLF-RAYET STARS; EVOLUTION AB We present IUE observations and their analysis of the massive WN6 + O binary system HDE 311884. The phase-dependent variations are like those of WN4-6 binaries studied previously, with atmospheric eclipses evident in the N IV 1718 angstrom and C IV 1550 angstrom lines, and in the Fe V + VI pseudocontinuum at lambda < 1480 angstrom. The considerable variability longward of 1700 angstrom is due mostly to Fe II and Fe III lines. C1 UNIV MONTREAL,DEPT PHYS,MONTREAL H3C 3J7,QUEBEC,CANADA. UNIV CALIF LOS ALAMOS SCI LAB,LOS ALAMOS,NM 87545. RP KOENIGSBERGER, G (reprint author), NATL AUTONOMOUS UNIV MEXICO,INST ASTRON,APDO POSTAL 70264,MEXICO CITY 04510,DF,MEXICO. NR 21 TC 0 Z9 0 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 JUL 20 PY 1991 VL 376 IS 1 BP 272 EP 277 DI 10.1086/170277 PN 1 PG 6 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA FX238 UT WOS:A1991FX23800029 ER PT J AU CHENG, XD SCHOENBORN, BP AF CHENG, XD SCHOENBORN, BP TI NEUTRON-DIFFRACTION STUDY OF CARBONMONOXYMYOGLOBIN SO JOURNAL OF MOLECULAR BIOLOGY LA English DT Article DE NEUTRON DIFFRACTION; MYOGLOBIN; HYDROGEN BONDING ID CO BOND ANGLE; SPERM WHALE; ELECTROSTATIC STABILIZATION; COORDINATION-COMPLEXES; CATALYTIC PROPERTIES; REFINEMENT PROCEDURE; PROTEIN CRYSTALS; MYOGLOBIN; RESOLUTION; CARBOXYMYOGLOBIN C1 BROOKHAVEN NATL LAB,DEPT BIOL,CTR STRUCT BIOL,UPTON,NY 11973. SUNY STONY BROOK,DEPT PHYS,STONY BROOK,NY 11794. NR 36 TC 167 Z9 167 U1 0 U2 4 PU ACADEMIC PRESS LTD PI LONDON PA 24-28 OVAL RD, LONDON, ENGLAND NW1 7DX SN 0022-2836 J9 J MOL BIOL JI J. Mol. Biol. PD JUL 20 PY 1991 VL 220 IS 2 BP 381 EP 399 DI 10.1016/0022-2836(91)90020-7 PG 19 WC Biochemistry & Molecular Biology SC Biochemistry & Molecular Biology GA FY714 UT WOS:A1991FY71400020 PM 1856864 ER PT J AU STEVENS, RG AF STEVENS, RG TI DIETARY-EFFECTS ON BREAST-CANCER SO LANCET LA English DT Letter ID IRON RP STEVENS, RG (reprint author), PACIFIC NW LAB, RICHLAND, WA 99352 USA. NR 7 TC 1 Z9 1 U1 0 U2 0 PU LANCET LTD PI LONDON PA 42 BEDFORD SQUARE, LONDON, ENGLAND WC1B 3SL SN 0140-6736 J9 LANCET JI Lancet PD JUL 20 PY 1991 VL 338 IS 8760 BP 186 EP 187 DI 10.1016/0140-6736(91)90175-O PG 2 WC Medicine, General & Internal SC General & Internal Medicine GA FX424 UT WOS:A1991FX42400035 PM 1677085 ER PT J AU ARNOLD, PB MATTIS, MP AF ARNOLD, PB MATTIS, MP TI GAUGE PROPAGATOR CONTRIBUTION TO HIGH-ENERGY BARYON NUMBER VIOLATION SO MODERN PHYSICS LETTERS A LA English DT Article AB The leading contribution of the gauge propagator to the inclusive baryon-number-violating cross-section in electroweak theory is calculated using the Levine-Yaffe propagator in the instanton background. The result resolves a current discrepancy between two calculational approaches to high energy baryon number violation, the "valley method" and the "R-term method." RP ARNOLD, PB (reprint author), ARGONNE NATL LAB,DIV HIGH ENERGY PHYS,ARGONNE,IL 60439, USA. NR 0 TC 22 Z9 22 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 0217-7323 J9 MOD PHYS LETT A JI Mod. Phys. Lett. A PD JUL 20 PY 1991 VL 6 IS 22 BP 2059 EP 2067 DI 10.1142/S0217732391002232 PG 9 WC Physics, Nuclear; Physics, Particles & Fields; Physics, Mathematical SC Physics GA FY723 UT WOS:A1991FY72300008 ER PT J AU ANTILLON, A FOREST, E HOENEISEN, B LEYVRAZ, F AF ANTILLON, A FOREST, E HOENEISEN, B LEYVRAZ, F TI TRANSPORT MATRICES FOR NONLINEAR LATTICE FUNCTIONS SO NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH SECTION A-ACCELERATORS SPECTROMETERS DETECTORS AND ASSOCIATED EQUIPMENT LA English DT Article ID HAMILTONIAN-SYSTEMS AB We review some of the methods currently used to reliably calculate quasi-invariants and we make transparent the relation between our previous work and part of this article, with the Lie algebraic technique. We construct the explicit relation between them for the problem of transverse motion of particles in a storage ring. Here, the onset of distortions of phase space due to amplitude and chromatic effects is well described by periodic functions in addition to the Courant-Snyder functions alpha, beta and gamma. To use the periodic functions at the design stage of the machine, it is necessary to compute these functions efficiently. For this purpose we also present a convenient list of transport matrices for the periodic functions. C1 UNIV SAN FRANCISCO QUITO,QUITO,ECUADOR. UNIV CALIF BERKELEY LAWRENCE BERKELEY LAB,ACCELERATOR & FUS RES DIV,EXPLORAT STUDIES GRP,BERKELEY,CA 94720. RP ANTILLON, A (reprint author), UNIV NACL AUTONOMA MEXICO,INST FIS,CUERNAVACA LAB,APDO POST 20364,MEXICO CITY 01000,DF,MEXICO. NR 20 TC 1 Z9 1 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 JUL 20 PY 1991 VL 305 IS 2 BP 247 EP 256 DI 10.1016/0168-9002(91)90544-Z PG 10 WC Instruments & Instrumentation; Nuclear Science & Technology; Physics, Nuclear; Physics, Particles & Fields SC Instruments & Instrumentation; Nuclear Science & Technology; Physics GA FY031 UT WOS:A1991FY03100004 ER PT J AU VANGINNEKEN, A AF VANGINNEKEN, A TI SMOOTHING ALGORITHM FOR HISTOGRAMS OF ONE OR MORE DIMENSIONS SO NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH SECTION A-ACCELERATORS SPECTROMETERS DETECTORS AND ASSOCIATED EQUIPMENT LA English DT Article ID SPLINE AB A smoothing algorithm based on the Bernstein polynomials and their higher dimensional generalizations is presented. It allows for easy introduction of boundary conditions and other constraints. RP VANGINNEKEN, A (reprint author), FERMI NATL ACCELERATOR LAB,POB 500,BATAVIA,IL 60510, USA. NR 16 TC 1 Z9 1 U1 1 U2 1 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0168-9002 J9 NUCL INSTRUM METH A JI Nucl. Instrum. Methods Phys. Res. Sect. A-Accel. Spectrom. Dect. Assoc. Equip. PD JUL 20 PY 1991 VL 305 IS 2 BP 453 EP 461 DI 10.1016/0168-9002(91)90567-A PG 9 WC Instruments & Instrumentation; Nuclear Science & Technology; Physics, Nuclear; Physics, Particles & Fields SC Instruments & Instrumentation; Nuclear Science & Technology; Physics GA FY031 UT WOS:A1991FY03100027 ER PT J AU DYTLEWSKI, N AF DYTLEWSKI, N TI DEAD-TIME CORRECTIONS FOR MULTIPLICITY COUNTERS SO NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH SECTION A-ACCELERATORS SPECTROMETERS DETECTORS AND ASSOCIATED EQUIPMENT LA English DT Letter AB Exact dead-time correction formulas are derived for the true mean and second factorial moment of a multiplicity distribution measured with a paralyzable dead-time system. RP DYTLEWSKI, N (reprint author), UNIV CALIF LOS ALAMOS SCI LAB,LOS ALAMOS,NM 87545, USA. NR 3 TC 11 Z9 13 U1 0 U2 4 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0168-9002 J9 NUCL INSTRUM METH A JI Nucl. Instrum. Methods Phys. Res. Sect. A-Accel. Spectrom. Dect. Assoc. Equip. PD JUL 20 PY 1991 VL 305 IS 2 BP 492 EP 494 DI 10.1016/0168-9002(91)90572-8 PG 3 WC Instruments & Instrumentation; Nuclear Science & Technology; Physics, Nuclear; Physics, Particles & Fields SC Instruments & Instrumentation; Nuclear Science & Technology; Physics GA FY031 UT WOS:A1991FY03100032 ER PT J AU DILLON, KA GROSSISSEROFF, R ISRAELI, M BIEGON, A AF DILLON, KA GROSSISSEROFF, R ISRAELI, M BIEGON, A TI AUTORADIOGRAPHIC ANALYSIS OF SEROTONIN 5-HT1A RECEPTOR-BINDING IN THE HUMAN BRAIN POSTMORTEM - EFFECTS OF AGE AND ALCOHOL SO BRAIN RESEARCH LA English DT Article DE SEROTONIN RECEPTOR; HUMAN BRAIN; AUTORADIOGRAPHY ID RECOGNITION SITES; SUICIDE VICTIMS; POST-MORTEM; DOPAMINE; LOCALIZATION; SYSTEMS; NEURONS; LIGAND AB Quantitative autoradiographic analysis of serotonin 5-HT1A receptors in the human brain, using [H-3]8-OH-DPAT as a ligand, reveals region-specific decreases in receptor labeling with age in several cortical and hippocampal regions and in the raphe nuclei. This is due to a change in receptor density (B(max)) with no apparent change in affinity (K(d)) as affirmed by saturation binding analysis on representative cortical regions. The presence of alcohol is associated with decreased binding in several cortical gyri. Suicide, gender and postmortem delay had no effect on 8-OH-DPAT binding. C1 UNIV CALIF BERKELEY LAWRENCE BERKELEY LAB,DIV RES MED & RADIAT BIOPHYS,1 CYCLOTRON RD,BERKELEY,CA 94720. NYU MED CTR,DEPT PSYCHIAT,NEW YORK,NY 10016. WEIZMANN INST SCI,DEPT NEUROBIOL,IL-76100 REHOVOT,ISRAEL. NR 35 TC 160 Z9 161 U1 0 U2 1 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0006-8993 J9 BRAIN RES JI Brain Res. PD JUL 19 PY 1991 VL 554 IS 1-2 BP 56 EP 64 DI 10.1016/0006-8993(91)90171-Q PG 9 WC Neurosciences SC Neurosciences & Neurology GA FZ504 UT WOS:A1991FZ50400008 PM 1834306 ER PT J AU ALLEMAND, PM KHEMANI, KC KOCH, A WUDL, F HOLCZER, K DONOVAN, S GRUNER, G THOMPSON, JD AF ALLEMAND, PM KHEMANI, KC KOCH, A WUDL, F HOLCZER, K DONOVAN, S GRUNER, G THOMPSON, JD TI ORGANIC MOLECULAR SOFT FERROMAGNETISM IN A FULLERENE-C60 SO SCIENCE LA English DT Article ID CHARGE-TRANSFER COMPLEXES; INTERMOLECULAR INTERACTIONS; CRYSTALS; CARBON; C-60; FORM AB The properties of an organic molecular ferromagnet [C60TDAE0.86; TDAE is tetrakis(dimethylamino)ethylene] with a Curie temperature T(c) = 16.1 kelvin are described. The ferromagnetic state shows no remanence, and the temperature dependence of the magnetization below T(c) does not follow the behavior expected of a conventional ferromagnet. These results are interpreted as a reflection of a three-dimensional system leading to a soft ferromagnet. C1 UNIV CALIF SANTA BARBARA,DEPT PHYS,SANTA BARBARA,CA 93106. UNIV CALIF SANTA BARBARA,INST POLYMERS & ORGAN SOLIDS,SANTA BARBARA,CA 93106. UNIV CALIF LOS ANGELES,DEPT PHYS,LOS ANGELES,CA 90024. UNIV CALIF LOS ALAMOS SCI LAB,LOS ALAMOS,NM 87545. RP ALLEMAND, PM (reprint author), UNIV CALIF SANTA BARBARA,DEPT CHEM,SANTA BARBARA,CA 93106, USA. NR 29 TC 1052 Z9 1059 U1 17 U2 115 PU AMER ASSOC ADVANCEMENT SCIENCE PI WASHINGTON PA 1200 NEW YORK AVE, NW, WASHINGTON, DC 20005 SN 0036-8075 J9 SCIENCE JI Science PD JUL 19 PY 1991 VL 253 IS 5017 BP 301 EP 303 DI 10.1126/science.253.5017.301 PG 3 WC Multidisciplinary Sciences SC Science & Technology - Other Topics GA FX224 UT WOS:A1991FX22400035 PM 17794696 ER PT J AU COVEY, C AF COVEY, C TI CLIMATE CHANGE - CREDIT THE OCEANS SO NATURE LA English DT Editorial Material ID HEAT-TRANSPORT; CIRCULATION; MODEL RP COVEY, C (reprint author), UNIV CALIF LAWRENCE LIVERMORE NATL LAB,POB 808,L-264,LIVERMORE,CA 94550, USA. NR 12 TC 6 Z9 6 U1 0 U2 1 PU MACMILLAN MAGAZINES LTD PI LONDON PA 4 LITTLE ESSEX STREET, LONDON, ENGLAND WC2R 3LF SN 0028-0836 J9 NATURE JI Nature PD JUL 18 PY 1991 VL 352 IS 6332 BP 196 EP 197 DI 10.1038/352196a0 PG 2 WC Multidisciplinary Sciences SC Science & Technology - Other Topics GA FX185 UT WOS:A1991FX18500037 ER PT J AU BERGER, MS CHANOWITZ, MS AF BERGER, MS CHANOWITZ, MS TI STRONG W+W+ SCATTERING AT THE SSC SO PHYSICS LETTERS B LA English DT Article ID ELECTROWEAK SYMMETRY-BREAKING; INTERACTING WS; EQUIVALENCE THEOREM; ZS; APPROXIMATION; UNITARITY; PHYSICS; PAIRS AB WW scattering is a general probe of the strength of the still unknown fifth force that breaks the electroweak symmetry. For the design energy and luminosity of the SSC we find that strong WW scattering signals in the like-charge W+W+ + W-W- channel exceed the irreducible background by many standard deviations. An important feature of the analysis is the use of leptonic observables that distinguish between the longitudinal polarization of the signal and the predominantly transverse polarization of the background. RP BERGER, MS (reprint author), UNIV CALIF BERKELEY LAWRENCE BERKELEY LAB,DIV PHYS,THEORET PHYS RES INST,1 CYCLOTRON RD,BERKELEY,CA 94720, USA. NR 32 TC 24 Z9 24 U1 0 U2 0 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0370-2693 J9 PHYS LETT B JI Phys. Lett. B PD JUL 18 PY 1991 VL 263 IS 3-4 BP 509 EP 516 DI 10.1016/0370-2693(91)90497-E PG 8 WC Astronomy & Astrophysics; Physics, Nuclear; Physics, Particles & Fields SC Astronomy & Astrophysics; Physics GA FY433 UT WOS:A1991FY43300029 ER PT J AU VALENCIA, G SONI, A AF VALENCIA, G SONI, A TI ADDITIONAL CP ODD OBSERVABLES IN Z-DECAYS SO PHYSICS LETTERS B LA English DT Article ID ELECTRIC-DIPOLE MOMENT; HIGGS-BOSON-EXCHANGE; NONCONSERVATION; NEUTRON; VIOLATION; TERMS AB Recently, T-odd observables in Z-boson decays have been studied from the point of view of effective lagrangians. We consider additional CP-odd observables that appear in conjunction with absorptive phases. As an example we discuss the possibility of observing a CP violating energy asymmetry in the decays Z --> BX and Z --> BXBAR, and we related this to the presence of an electroweak dipole moment of the b-quark. We estimate that expected LEP performance could yield a sensitivity to dipole moments of the order of 10(-17) e cm. C1 BROOKHAVEN NATL LAB,DEPT PHYS,UPTON,NY 11973. RP VALENCIA, G (reprint author), CERN,DIV THEORY,CH-1211 GENEVA 23,SWITZERLAND. NR 28 TC 21 Z9 21 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 JUL 18 PY 1991 VL 263 IS 3-4 BP 517 EP 522 DI 10.1016/0370-2693(91)90498-F PG 6 WC Astronomy & Astrophysics; Physics, Nuclear; Physics, Particles & Fields SC Astronomy & Astrophysics; Physics GA FY433 UT WOS:A1991FY43300030 ER PT J AU KRAKAUER, DA TALAGA, RL ALLEN, RC CHEN, HH DOE, PJ HAUSAMMANN, R LEE, WP LU, XQ MAHLER, HJ POTTER, ME WANG, KC YAO, H BOWLES, TJ BURMAN, RL CARLINI, RD COCHRAN, DRF FRANK, JS PIASETZKY, E SANDBERG, VD AF KRAKAUER, DA TALAGA, RL ALLEN, RC CHEN, HH DOE, PJ HAUSAMMANN, R LEE, WP LU, XQ MAHLER, HJ POTTER, ME WANG, KC YAO, H BOWLES, TJ BURMAN, RL CARLINI, RD COCHRAN, DRF FRANK, JS PIASETZKY, E SANDBERG, VD TI SEARCH FOR THE EXOTIC DECAY MU+-]E+NU-BARE-NU-MU SO PHYSICS LETTERS B LA English DT Article ID CROSS-SECTION; NEUTRINO; NUMBER AB We search for the exotic decay-mu+ --> e+ nu-eBAR nu-mu as a test of lepton-number conversation. An exposure of almost-equal-to 10(20) mu+-decay neutrinos to a 15 ton detector leads to a new upper bound for the branching ratio, R = GAMMA (mu+ --> e+ nu-eBAR nu-mu)/GAMMA (mu+ --> all), R < 0.018 (90% CL). C1 UNIV MARYLAND,COLLEGE PK,MD 20742. UNIV CALIF IRVINE,IRVINE,CA 92717. UNIV CALIF LOS ALAMOS SCI LAB,LOS ALAMOS,NM 87545. NR 19 TC 10 Z9 10 U1 0 U2 0 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0370-2693 J9 PHYS LETT B JI Phys. Lett. B PD JUL 18 PY 1991 VL 263 IS 3-4 BP 534 EP 538 DI 10.1016/0370-2693(91)90501-G PG 5 WC Astronomy & Astrophysics; Physics, Nuclear; Physics, Particles & Fields SC Astronomy & Astrophysics; Physics GA FY433 UT WOS:A1991FY43300033 ER PT J AU FRABETTI, PL BOGART, CW CHEUNG, HWK CULY, S CUMALAT, JP BUTLER, JN DAVENPORT, F GAINES, I GARBINCIUS, PH GOURLAY, S HARDING, DJ KASPER, P KREYMER, A LEBRUN, P MENDEZ, H BIANCO, S ENORINI, M FABBRI, FL SPALLONE, A ZALLO, A CULBERTSON, R JAROSS, G LINGEL, K SHELDON, PD WILSON, JR WISS, J ALIMONTI, G BELLINI, G DICORATO, M GIAMMARCHI, M INZANI, P MALVEZZI, S MANFREDI, PF MENASCE, D MORONI, L PEDRINI, D PERASSO, L SALA, A SALA, S TORRETTA, D VITTONE, M BUCHHOLZ, D CASTOLDI, C GOBBI, B PARK, S YOSHIDA, R BISHOP, JM BUSENITZ, JK CASON, NM CUNNINGHAM, JD GARDNER, RW KENNEDY, CJ MANNEL, EJ MOUNTAIN, RJ PUSELJIC, DL RUCHTI, RC SHEPHARD, WD ZANABRIA, ME RATTI, SP VITULO, P LOPEZ, A AF FRABETTI, PL BOGART, CW CHEUNG, HWK CULY, S CUMALAT, JP BUTLER, JN DAVENPORT, F GAINES, I GARBINCIUS, PH GOURLAY, S HARDING, DJ KASPER, P KREYMER, A LEBRUN, P MENDEZ, H BIANCO, S ENORINI, M FABBRI, FL SPALLONE, A ZALLO, A CULBERTSON, R JAROSS, G LINGEL, K SHELDON, PD WILSON, JR WISS, J ALIMONTI, G BELLINI, G DICORATO, M GIAMMARCHI, M INZANI, P MALVEZZI, S MANFREDI, PF MENASCE, D MORONI, L PEDRINI, D PERASSO, L SALA, A SALA, S TORRETTA, D VITTONE, M BUCHHOLZ, D CASTOLDI, C GOBBI, B PARK, S YOSHIDA, R BISHOP, JM BUSENITZ, JK CASON, NM CUNNINGHAM, JD GARDNER, RW KENNEDY, CJ MANNEL, EJ MOUNTAIN, RJ PUSELJIC, DL RUCHTI, RC SHEPHARD, WD ZANABRIA, ME RATTI, SP VITULO, P LOPEZ, A TI A MEASUREMENT OF THE D0 AND D+ LIFETIMES SO PHYSICS LETTERS B LA English DT Article AB We present precision measurements of the D0 and D+ meson lifetimes using approximately 7500 fully reconstructed D0 --> K-pi+, K-pi+pi+pi-, D+ --> K-pi+pi+, and charge conjugate decays. The data were accumulated by the Fermilab high energy photoproduction experiment E687. The lifetime of the D0 is measured to be 0.424 +/- 0.011 +/- 0.007 ps while the D+ lifetime is measured to be 1.075 +/- 0.040 +/- 0.018 ps. C1 IST NAZL FIS NUCL,I-40126 BOLOGNA,ITALY. UNIV COLORADO,BOULDER,CO 80309. FERMI NATL ACCELERATOR LAB,BATAVIA,IL 60510. IST NAZL FIS NUCL,LAB NAZL FRASCATI,I-00044 FRASCATI,ITALY. UNIV ILLINOIS,URBANA,IL 61801. UNIV MILAN,DIPARTMENTO FIS,I-20133 MILAN,ITALY. NORTHWESTERN UNIV,EVANSTON,IL 60208. IST NAZL FIS NUCL,I-20133 MILAN,ITALY. UNIV NOTRE DAME,NOTRE DAME,IN 46556. UNIV PAVIA,DIPARTIMENTO FIS NUCL,I-27100 PAVIA,ITALY. IST NAZL FIS NUCL,I-27100 PAVIA,ITALY. UNIV PUERTO RICO,MAYAGUEZ,PR 00708. RP FRABETTI, PL (reprint author), UNIV BOLOGNA,DIPARTMENTO FIS,I-40126 BOLOGNA,ITALY. RI Menasce, Dario Livio/A-2168-2016 OI bianco, stefano/0000-0002-8300-4124; Menasce, Dario Livio/0000-0002-9918-1686 NR 3 TC 17 Z9 17 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 JUL 18 PY 1991 VL 263 IS 3-4 BP 584 EP 590 DI 10.1016/0370-2693(91)90508-N PG 7 WC Astronomy & Astrophysics; Physics, Nuclear; Physics, Particles & Fields SC Astronomy & Astrophysics; Physics GA FY433 UT WOS:A1991FY43300040 ER PT J AU CHOI, MG ANGELICI, RJ AF CHOI, MG ANGELICI, RJ TI SYNTHESIS, REACTIVITY, AND SE-77 NMR-STUDIES OF THE ETA-2(SE)-SELENOPHENE AND ETA-1(SE)-SELENOPHENE COMPLEXES CP'(CO)2RE(SEL) SO JOURNAL OF THE AMERICAN CHEMICAL SOCIETY LA English DT Article ID TRANSITION-METAL COMPLEXES; CRYSTAL-STRUCTURE; THIOPHENE; SELENOPHENE; COORDINATION; ISOMERS AB Selenophenes coordinate in CP'(CO)2Re(Sel) (Cp' = C5H5 or C5Me5; Sel = selenophenes) as a rapidly equilibrating mixture of eta-1(Se) and eta-2 isomers. Increasing the electron density on the Re by replacing Cp with Cp* favors eta-2-coordination, [GRAPHICS] while addition of methyl groups to the selenophene favors the eta-1(Se) isomer. These shifts in the eta-2 reversible eta-1(Se) equilibrium can be readily explained by noting that electron-donating methyl groups in the selenophene enhance the donor ability of the Se and reduce the pi-acceptor ability of the olefin which favors Se-coordination, while increasing the electron density on the Re strengthens pi-back-bonding to the eta-2 ligand. The uncoordinated selenophene Se atom in Cp*(CO)2Re(eta-2-Sel) (1) is capable of binding to M(CO)4(L)(THF) (M = Cr, Mo, W; L = CO or PPh3) to give dinuclear selenophene-bridged complexes CP*(CO)2Re(mu-2-eta-2(Se)-Sel)[M(CO)4(L)] in which the selenophene is eta-2 bonded to the Re and Se-bonded to a second metal (M). The reaction of 1 with Fe2(CO)9 gives three different types of compounds. One of them (11) results from Fe(CO)4 addition to the Se of the eta-2 isomer; another presumably results from coordination of Fe(CO)3 to the diene portion of the eta-1(Se) isomer. The third product has a thiaferrole-type structure in which a C-Se bond bas been cleaved. ''Se NMR studies of these different types of selenophene complexes are also reported. C1 IOWA STATE UNIV SCI & TECHNOL,DEPT CHEM,GILMAN HALL,AMES,IA 50011. IOWA STATE UNIV SCI & TECHNOL,US DOE,AMES LAB,AMES,IA 50011. NR 53 TC 45 Z9 45 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 JUL 17 PY 1991 VL 113 IS 15 BP 5651 EP 5657 DI 10.1021/ja00015a019 PG 7 WC Chemistry, Multidisciplinary SC Chemistry GA FX878 UT WOS:A1991FX87800019 ER PT J AU STEVENS, FJ SOLOMON, A SCHIFFER, M AF STEVENS, FJ SOLOMON, A SCHIFFER, M TI JONES,BENCE PROTEINS - A POWERFUL TOOL FOR THE FUNDAMENTAL-STUDY OF PROTEIN CHEMISTRY AND PATHOPHYSIOLOGY SO BIOCHEMISTRY LA English DT Article ID BENCE-JONES PROTEIN; IMMUNOGLOBULIN DEPOSITION DISEASE; ESCHERICHIA-COLI; VARIABLE DOMAINS; LIGHT-CHAINS; MOLECULAR-STRUCTURE; X-RAY; ANTIGEN; DIMER; CRYSTAL C1 UNIV TENNESSEE,MED CTR,GRAD SCH MED,DEPT MED,HUMAN IMMUNOL & CANC PROGRAM,KNOXVILLE,TN 37920. RP STEVENS, FJ (reprint author), ARGONNE NATL LAB,DIV BIOL & MED RES,ARGONNE,IL 60439, USA. FU NCI NIH HHS [CA-10056] NR 34 TC 44 Z9 44 U1 1 U2 1 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 SN 0006-2960 J9 BIOCHEMISTRY-US JI Biochemistry PD JUL 16 PY 1991 VL 30 IS 28 BP 6803 EP 6805 DI 10.1021/bi00242a001 PG 3 WC Biochemistry & Molecular Biology SC Biochemistry & Molecular Biology GA FX130 UT WOS:A1991FX13000001 PM 2069946 ER PT J AU SCHOTT, DR SHYAMALA, G SCHNEIDER, W PARRY, G AF SCHOTT, DR SHYAMALA, G SCHNEIDER, W PARRY, G TI MOLECULAR-CLONING, SEQUENCE ANALYSES, AND EXPRESSION OF COMPLEMENTARY-DNA ENCODING MURINE PROGESTERONE-RECEPTOR SO BIOCHEMISTRY LA English DT Article ID MONOCLONAL-ANTIBODIES; MESSENGER-RNA; A-RECEPTORS; GENE; PHOSPHORYLATION; TRANSCRIPTION; FORM; CELLS; STEP AB Progesterone receptors exist in two molecular forms commonly designated as "A" and "B" forms, the relative proportion of which can vary among species. In murine tissues, progesterone receptor exists predominantly as the "A" form which, in mammary glands, is also under developmental regulation [Shyamala et al. (1990) Endocrinology 126, 2882-2889]. Therefore, toward resolving the molecular mechanisms responsible for the predominance of the "A" form of progesterone receptor in murine tissues and its developmental regulation, we have isolated, sequenced, and expressed the complementary DNA corresponding to the mouse progesterone receptor. Nucleotide sequence analysis revealed two in-frame ATG codons, such that the largest open reading frame beginning with the first codon could encode a polypeptide with an estimated molecular weight of 99089, while the shorter open reading frame beginning with the second codon could produce a polypeptide with a calculated molecular weight of 81 829. The murine progesterone receptor had complete identity for the DNA binding domain of human and rabbit progesterone receptors and 99% homology with the chicken progesterone receptor; for the steroid binding domain, it had 96% homology with human and rabbit progesterone receptors and 86% homology with chicken progesterone receptors. Expression of the complete complementary DNA in Chinese hamster ovary cells yielded a protein which bound the synthetic progestin promegestone with an equilibrium dissociation constant of approximately 1 nM, and in Western blot analyses revealed both "A" and "B" forms of immunoreactive receptor. C1 UNIV CALIF BERKELEY LAWRENCE BERKELEY LAB,DIV CELL & MOLEC BIOL,BERKELEY,CA 94720. SIR MORTIMER B DAVIS JEWISH HOSP,LADY DAVIS INST MED RES,MONTREAL H3T 1E2,QUEBEC,CANADA. FU NICHD NIH HHS [HD-22762] NR 38 TC 84 Z9 86 U1 0 U2 1 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 SN 0006-2960 J9 BIOCHEMISTRY-US JI Biochemistry PD JUL 16 PY 1991 VL 30 IS 28 BP 7014 EP 7020 DI 10.1021/bi00242a029 PG 7 WC Biochemistry & Molecular Biology SC Biochemistry & Molecular Biology GA FX130 UT WOS:A1991FX13000029 PM 2069958 ER PT J AU DOSANJH, MK SINGER, B ESSIGMANN, JM AF DOSANJH, MK SINGER, B ESSIGMANN, JM TI COMPARATIVE MUTAGENESIS OF O6-METHYLGUANINE AND O4-METHYLTHYMINE IN ESCHERICHIA-COLI SO BIOCHEMISTRY LA English DT Article ID SITE-SPECIFIC MUTAGENESIS; DNA-POLYMERASE-I; UNIQUE SITE; PHYSICAL CHARACTERIZATION; ADAPTIVE RESPONSE; ALKYLATING-AGENTS; EXCISION REPAIR; O-6-METHYLGUANINE; INVIVO; OLIGODEOXYNUCLEOTIDES AB The qualitative and quantitative features of mutagenesis by two DNA adducts of carcinogenic alkylating agents, O6-methylguanine (m6G) and O4-methylthymine (m4T), were examined in vivo. The deoxyhexanucleotides 5'-GCTAGC-3' and 5'-GCTAGC-3' were synthesized, where the underlined bases are the positions of m4T or m6G, respectively. By use of recombinant DNA techniques, the respective hexanucleotides or an unmodified control were inserted into a six-base gap in the otherwise duplex genome of the Escherichia coli virus M13mp19-NheI. The duplex adducted genome was converted to single-stranded form and introduced into an E. coli strain that was phenotypically normal with regard to m6G/m4T repair, a strain deficient in repair by virtue of an insertion in the gene encoding the Ada-m6G/m4T DNA methyltransferase, or the same two cell lines after challenge with N-methyl-N'-nitro-N-nitrosoguanidine. Treatment with this alkylating agent chemically compromises alkyl-DNA repair functions. The mutation efficiency of m6G was low or undetectable (0-1.7%) in all cell systems tested, owing, we believe, to rapid repair. In striking Contrast, the mutagenicity of m4T was high (12%) in cells fully competent to repair alkylation damage and was roughly doubled when those cells were pretreated with N-methyl-N'-nitro-N-nitrosoguanidine to suppress repair. Taken together, these data suggest that m4T is potentially more mutagenic than m6G and, if formed by a DNA methylating agent, may pose a significant threat to the genetic integrity of an organism. C1 MIT,WHITAKER COLL HLTH SCI & TECHNOL,DEPT CHEM,CAMBRIDGE,MA 02139. UNIV CALIF BERKELEY LAWRENCE BERKELEY LAB,DONNER LAB,BERKELEY,CA 94720. MIT,WHITAKER COLL HLTH SCI & TECHNOL,DIV TOXICOL,CAMBRIDGE,MA 02139. FU NCI NIH HHS [CA42736, CA52127] NR 40 TC 61 Z9 61 U1 1 U2 3 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 SN 0006-2960 J9 BIOCHEMISTRY-US JI Biochemistry PD JUL 16 PY 1991 VL 30 IS 28 BP 7027 EP 7033 DI 10.1021/bi00242a031 PG 7 WC Biochemistry & Molecular Biology SC Biochemistry & Molecular Biology GA FX130 UT WOS:A1991FX13000031 PM 2069960 ER PT J AU CHANG, HP JOHNSON, DC AF CHANG, HP JOHNSON, DC TI VOLTAMMETRIC RESPONSE OF DIMETHYL-SULFOXIDE AT GOLD ELECTRODES MODIFIED BY THIN-FILMS OF BISMUTH-DOPED LEAD DIOXIDE SO ANALYTICA CHIMICA ACTA LA English DT Article DE VOLTAMMETRY; DIMETHYL SULFOXIDE; DMSO; ELECTROCATALYSIS; LEAD DIOXIDE ID OXYGEN-TRANSFER REACTIONS; GLASSY-CARBON ELECTRODE; BLUE-MODIFIED ELECTRODES; PRUSSIAN-BLUE; ELECTROCATALYTIC OXIDATION; CHLORINE EVOLUTION; METAL-OXIDES; ACIDIC MEDIA; COATINGS; REDUCTION AB The anodic oxidation of dimethyl sulphoxide (DMSO) to DMSO2 is representative of numerous anodic oxygen-transfer reactions that do not occur at appreciable rates at conventional anodes, e.g., noble metals and carbon. However, useful voltammetric waves can be obtained at noble metal electrodes modified by thin films of electrodeposited, bismuth(V)-doped lead dioxide (Bi-PbO2). Voltammetric data for anodic deposition with cathodic stripping of Bi-PbO2 films are examined for gold rotated disk electrodes in 1.0 M HClO4 containing Pb2+ with Bi3+. Evidence is shown that ultra-thin films (< ca. 1-mu-m) of a reduced oxide, designated "Bi-PbO", remain on the Au substrate when thick Bi-PbO2 films (> ca. 10-mu-m) are voltammetrically stripped under rapid potential scan. The ultra-thin films possess a larger atomic ratio of Bi/Pb than the original thicker films and, following reoxidation to Bi-PbO2, they display greater catalytic activity. The effect is interpreted on the basis of mediation of the oxygen-transfer step. C1 IOWA STATE UNIV SCI & TECHNOL,DEPT CHEM,AMES,IA 50011. RP CHANG, HP (reprint author), IOWA STATE UNIV SCI & TECHNOL,AMES LAB,AMES,IA 50011, USA. NR 58 TC 18 Z9 18 U1 2 U2 6 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 JUL 15 PY 1991 VL 248 IS 1 BP 85 EP 94 DI 10.1016/S0003-2670(00)80872-7 PG 10 WC Chemistry, Analytical SC Chemistry GA FY566 UT WOS:A1991FY56600008 ER PT J AU HALE, PD BOGUSLAVSKY, LI KARAN, HI LAN, HL LEE, HS OKAMOTO, Y SKOTHEIM, TA AF HALE, PD BOGUSLAVSKY, LI KARAN, HI LAN, HL LEE, HS OKAMOTO, Y SKOTHEIM, TA TI INVESTIGATION OF VIOLOGEN DERIVATIVES AS ELECTRON-TRANSFER MEDIATORS IN AMPEROMETRIC GLUCOSE SENSORS SO ANALYTICA CHIMICA ACTA LA English DT Article DE AMPEROMETRY; CYCLIC VOLTAMMETRY; ENZYME ELECTRODES; GLUCOSE; VIOLOGENS ID CARBON-PASTE ELECTRODE; ENZYME ELECTRODE; OXIDASE; POLYMER; ELECTROCHEMISTRY; BENZOQUINONE; OXIDATION AB Using experiments involving cyclic voltammetry and stationary potential measurements, it was shown that several water-soluble viologens, N,N'-di(4-nitrobenzyl)viologen dichloride, poly(o-xylylviologen dibromide) and poly(p-xylylviologen dibromide), can efficiently mediate electron transfer from reduced glucose oxidase to a conventional carbon paste electrode. Whereas most viologens cannot serve as electron-transfer mediators for flavoenzymes owing to their highly negative redox potentials, these molecules have sufficiently anodic redox potentials (more positive than that of flavin adenine dinucleotide) that they can reoxidize reduced glucose oxidase. These redox potentials are, however, sufficiently cathodic that glucose sensors based on glucose oxidase and these mediators can be operated in a potential range where the oxidation of common interfering species, such as ascorbic acid and uric acid, does not occur. C1 CUNY MEDGAR EVERS COLL,DIV NAT SCI & MATH,BROOKLYN,NY 11225. POLYTECH INST NEW YORK,DEPT CHEM,BROOKLYN,NY 11201. BROOKHAVEN NATL LAB,DEPT APPL SCI,UPTON,NY 11973. RP HALE, PD (reprint author), SUNY STONY BROOK,MOLTECH CORP,CHEM BLDG,STONY BROOK,NY 11794, USA. NR 20 TC 33 Z9 33 U1 1 U2 1 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 JUL 15 PY 1991 VL 248 IS 1 BP 155 EP 161 DI 10.1016/S0003-2670(00)80879-X PG 7 WC Chemistry, Analytical SC Chemistry GA FY566 UT WOS:A1991FY56600015 ER PT J AU SMITH, FG WIEDERIN, DR HOUK, RS EGAN, CB SERFASS, RE AF SMITH, FG WIEDERIN, DR HOUK, RS EGAN, CB SERFASS, RE TI MEASUREMENT OF BORON CONCENTRATION AND ISOTOPE RATIOS IN BIOLOGICAL SAMPLES BY INDUCTIVELY COUPLED PLASMA MASS-SPECTROMETRY WITH DIRECT INJECTION NEBULIZATION SO ANALYTICA CHIMICA ACTA LA English DT Article DE MASS SPECTROMETRY; BIOLOGICAL SAMPLES; BORON; NEBULIZATION ID WATERS AB A method for the determination of boron in a variety of biological samples is described. Sample material is fused with sodium carbonate and boron is separated from matrix components by using Amberlite IRA-743 boron selective ion-exchange resin. Boron is eluted with 1% HNO3 and samples are introduced to an inductively coupled plasma mass spectrometer with a direct injection nebulizer. This nebulizer provides a fast sample cleanout of ca. 15 s. The B-10/B-11 ratio is determined with a relative standard deviation (RSD) of 0.4-1.5%, and the detection limit for boron is approximately 1 ng g-1 in these samples. Stable isotope dilution methodology for quantitation of boron shows that: (1) fusion of sample with sodium carbonate avoids volatilization of boron from samples; (2) approximately 80% of submicrogram amounts of boron from samples can be recovered from the resin with insignificant isotopic fractionation; (3) results for biological reference materials are in agreement with certified values; and (4) the boron concentration of pooled human blood plasma is 24 +/- 4-mu-g l-1 (95% confidence interval). C1 IOWA STATE UNIV SCI & TECHNOL,DEPT CHEM,AMES,IA 50011. IOWA STATE UNIV SCI & TECHNOL,DEPT FOOD & NUTR,AMES,IA 50011. RP SMITH, FG (reprint author), US DOE,AMES LAB,AMES,IA 50011, USA. NR 21 TC 58 Z9 61 U1 0 U2 8 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 JUL 15 PY 1991 VL 248 IS 1 BP 229 EP 234 DI 10.1016/S0003-2670(00)80889-2 PG 6 WC Chemistry, Analytical SC Chemistry GA FY566 UT WOS:A1991FY56600025 ER PT J AU SMITH, FG WIEDERIN, DR HOUK, RS AF SMITH, FG WIEDERIN, DR HOUK, RS TI ARGON XENON PLASMA FOR ALLEVIATING POLYATOMIC ION INTERFERENCES IN INDUCTIVELY COUPLED PLASMA MASS-SPECTROMETRY SO ANALYTICAL CHEMISTRY LA English DT Article ID AQUEOUS-SOLUTIONS; HELIUM PLASMA; MIXED-GAS; ICP-MS; NONMETALS; NITROGEN; METALS; SYSTEM AB Xenon is added at 10 or 37 mL min-1 to the aerosol gas flow of an argon inductively coupled plasma mass spectrometer. Addition of xenon substantially reduces polyatomic ions such as N2+, HN2+, NO+, ArH+, CIO+, ArC+, CIOH+, ArN+, and ArO+ and facilitates the measurement of Si-28, Si-29, K-39, K-41, V-51, Cr-52, Cr-53, Cr-54, Fe-54, and Fe-58. Isotope ratios are determined with relative standard deviations from 0.6% to 1.6%. Detection limits for the above elements range from 0.3 to 2-mu-g L-1. C1 IOWA STATE UNIV SCI & TECHNOL,US DOE,AMES LAB,DEPT CHEM,AMES,IA 50011. NR 32 TC 49 Z9 51 U1 1 U2 4 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 SN 0003-2700 J9 ANAL CHEM JI Anal. Chem. PD JUL 15 PY 1991 VL 63 IS 14 BP 1458 EP 1462 DI 10.1021/ac00014a021 PG 5 WC Chemistry, Analytical SC Chemistry GA FW297 UT WOS:A1991FW29700022 ER PT J AU MINNICK, MF SMALL, CL FRAZIER, ME MALLAVIA, LP AF MINNICK, MF SMALL, CL FRAZIER, ME MALLAVIA, LP TI ANALYSIS OF THE CBHE' PLASMID GENE FROM ACUTE DISEASE-CAUSING ISOLATES OF COXIELLA-BURNETII SO GENE LA English DT Note DE RECOMBINANT DNA; QPH1; QPRS; RICKETTSIAE, NUCLEOTIDE SEQUENCE; MEDICAL MICROBIOLOGY; CHRONIC DISEASE; Q-FEVER ID TRANSLATIONAL INITIATION; GEL-ELECTROPHORESIS; SECONDARY-STRUCTURE; ESCHERICHIA-COLI; Q-FEVER; SEQUENCES; PROTEINS; LIPOPOLYSACCHARIDE; IDENTIFICATION; ENDOCARDITIS AB A gene termed cbhE' was cloned from the QpH 1 plasmid of Coxiella burnetii. Expression of recombinants containing cbhE' in vitro and in Escherichia coli maxicells, produced an insert-encoded polypeptide of approx. 42 kDa. The CbhE protein was not cleaved when intact maxicells were treated with trypsin. Hybridizations of total DNA isolated from the six strains of C. burnetii indicate that this gene is unique to C. burnetii strains associated with acute disease, i.e., Hamilton[I], Vacca[II], and Rasche[III]. The cbhE' gene was not detected in strains associated with chronic disease (Biotzere[IV] and Corazon[V]) or the Dod[VI] strain. The cbhE' open reading frame (ORF) is 1022 bp in length and is preceded by a predicted promoter/Shine-Dalgarno (SD) region of TCAACT(-35)-N16-TAAAAT(-10)-N14-AGAAGGA (SD) located 10 nucleotides (nt) before the presumed AUG start codon. The ORF ends with a single UAA stop codon and has no apparent Rho-factor-independent terminator following it. The cbhE' gene codes for the CbhE protein of 341 amino acid (aa) residues with a deduced M(r) of 39442. CbhE is predominantly hydrophilic with a predicted pI of 4.43. The function of CbhE is unknown. No nt or aa sequences with homology to cbhE' or CbhE, respectively, were found in searches of a number of data bases. C1 WASHINGTON STATE UNIV, DEPT MICROBIOL, PULLMAN, WA 99164 USA. PACIFIC NW LAB, DEPT BIOL, RICHLAND, WA 99352 USA. FU NIAID NIH HHS [AI20190] NR 32 TC 13 Z9 14 U1 2 U2 2 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0378-1119 J9 GENE JI Gene PD JUL 15 PY 1991 VL 103 IS 1 BP 113 EP 118 DI 10.1016/0378-1119(91)90401-V PG 6 WC Genetics & Heredity SC Genetics & Heredity GA GD832 UT WOS:A1991GD83200019 PM 1879692 ER PT J AU OZTURK, N WILLIAMSON, W ANTOLAK, AJ AF OZTURK, N WILLIAMSON, W ANTOLAK, AJ TI ELASTIC-SCATTERING OF ELECTRONS AND POSITRONS BY BOUND GALLIUM AND ARSENIC ATOMS SO JOURNAL OF APPLIED PHYSICS LA English DT Article AB Elastic differential and total cross sections for positrons, from 5 eV to 10 keV, and for electrons, from 50 eV to 10 keV, scattered by bound gallium and arsenic atoms have been calculated using the method of partial waves. The optical potential consists of a static potential, a Buckingham-type polarization potential, and the Mittleman-Watson exchange potential (for electrons). Low-order partial wave phase shifts are computed by numerical integration of the radial part of the Schrodinger equation. For higher orders, a closed analytic expression is obtained in the first Born approximation for the phase shifts. The calculated total cross sections are parametrized in terms of the screened Rutherford cross section to be used in Monte Carlo transport codes. C1 SANDIA NATL LABS,DIV THEORET,LIVERMORE,CA 94551. RP OZTURK, N (reprint author), UNIV TOLEDO,DEPT PHYS & ASTRON,TOLEDO,OH 43606, USA. NR 12 TC 9 Z9 9 U1 0 U2 6 PU AMER INST PHYSICS PI WOODBURY PA CIRCULATION FULFILLMENT DIV, 500 SUNNYSIDE BLVD, WOODBURY, NY 11797-2999 SN 0021-8979 J9 J APPL PHYS JI J. Appl. Phys. PD JUL 15 PY 1991 VL 70 IS 2 BP 537 EP 542 PG 6 WC Physics, Applied SC Physics GA FY341 UT WOS:A1991FY34100002 ER PT J AU SPEAR, JD RUSSO, RE AF SPEAR, JD RUSSO, RE TI TRANSVERSE PHOTOTHERMAL BEAM DEFLECTION WITHIN A SOLID SO JOURNAL OF APPLIED PHYSICS LA English DT Article ID SPECTROSCOPY; PROBE AB The mirage effect within a transparent solid substrate was used for monitoring optical absorption of a thin film. Refractive index gradients, which accompany thermal gradients below the film-coated surface, cause a probe laser beam to be deflected. The spectrum of copper, deposited onto a piece of clear acrylic, was recorded by this method of photothermal deflection. The influence of thermally induced mechanical stresses can alter the effective value of the thermo-optic coefficient of the solid, dn/dT. RP SPEAR, JD (reprint author), UNIV CALIF BERKELEY LAWRENCE BERKELEY LAB,DIV APPL SCI,BERKELEY,CA 94720, USA. NR 19 TC 11 Z9 12 U1 0 U2 4 PU AMER INST PHYSICS PI WOODBURY PA CIRCULATION FULFILLMENT DIV, 500 SUNNYSIDE BLVD, WOODBURY, NY 11797-2999 SN 0021-8979 J9 J APPL PHYS JI J. Appl. Phys. PD JUL 15 PY 1991 VL 70 IS 2 BP 580 EP 586 DI 10.1063/1.349659 PG 7 WC Physics, Applied SC Physics GA FY341 UT WOS:A1991FY34100009 ER PT J AU SIVIA, DS HAMILTON, WA SMITH, GS RIEKER, TP PYNN, R AF SIVIA, DS HAMILTON, WA SMITH, GS RIEKER, TP PYNN, R TI A NOVEL EXPERIMENTAL PROCEDURE FOR REMOVING AMBIGUITY FROM THE INTERPRETATION OF NEUTRON AND X-RAY REFLECTIVITY MEASUREMENTS - SPECKLE HOLOGRAPHY SO JOURNAL OF APPLIED PHYSICS LA English DT Article AB The analysis of neutron or x-ray reflectivity data to obtain density profiles close to surfaces is akin to the notorious phaseless Fourier problem, well known in many fields such as crystallography. It is a difficult problem because a highly nonlinear transform relates the density profile to the data; this results in the existence of several very different solutions, which are also hard to find. A novel experimental procedure is presented, the analogue of astronomical speckle holography, which is designed to eliminate the ambiguity problems inherent in traditional reflectivity measurements. The theoretical basis of this procedure is explained, and it is illustrated with a simple example using both simulated and real experimental data. C1 UNIV CALIF LOS ALAMOS SCI LAB,MANUEL LUJAN JR NEUTRON SCATTERING CTR,LOS ALAMOS,NM 87545. NR 9 TC 32 Z9 34 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 JUL 15 PY 1991 VL 70 IS 2 BP 732 EP 738 DI 10.1063/1.349629 PG 7 WC Physics, Applied SC Physics GA FY341 UT WOS:A1991FY34100029 ER PT J AU ZOUBOULIS, ES GRIMSDITCH, M AF ZOUBOULIS, ES GRIMSDITCH, M TI REFRACTIVE-INDEX AND ELASTIC PROPERTIES OF SINGLE-CRYSTAL CORUNDUM (ALPHA-AL2O3) UP TO 2100-K SO JOURNAL OF APPLIED PHYSICS LA English DT Article AB We show that Brillouin scattering can be used to measure the elastic and optical properties of materials to very high temperatures. We have measured the elastic constants C-11, C33, and C44 of single-crystal sapphire in the temperature range 300-2100 K extending by 300 K the highest temperature previously attained with ultrasonic resonance techniques. The temperature dependence of the ordinary and extraordinary refractive indices n(o) and n(e) in the same temperature range have been obtained for the first time. Although both n(o) and n(e) are temperature dependent, the ratio n(o)/n(e) is found to be almost temperature independent. RP ZOUBOULIS, ES (reprint author), ARGONNE NATL LAB,DIV MAT SCI,ARGONNE,IL 60439, USA. NR 19 TC 49 Z9 50 U1 1 U2 13 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 JUL 15 PY 1991 VL 70 IS 2 BP 772 EP 776 DI 10.1063/1.349633 PG 5 WC Physics, Applied SC Physics GA FY341 UT WOS:A1991FY34100034 ER PT J AU WILLIAMS, RK ALEXANDER, KB BRYNESTAD, J HENSON, TJ KROEGER, DM LINDEMER, TB MARSH, GC SCARBROUGH, JO SPECHT, ED AF WILLIAMS, RK ALEXANDER, KB BRYNESTAD, J HENSON, TJ KROEGER, DM LINDEMER, TB MARSH, GC SCARBROUGH, JO SPECHT, ED TI OXIDATION INDUCED DECOMPOSITION OF YBA2CU3O7-X SO JOURNAL OF APPLIED PHYSICS LA English DT Article ID PHASE-DIAGRAMS; OXYGEN; PRESSURES; YBA2CU4O8; STABILITY; SYSTEM AB At low oxygen potentials, YBa2Cu3O7-x decomposes by chemical reactions involving reduction. The results of this study show that the compound also decomposes at higher oxygen potentials. The initial decomposition products were found to be Y2BaCuO5 and a Ba-Cu oxide phase. The Ba-Cu phase was found to be a peroxide-type and the decomposition can be described by a chemical reaction involving oxidation: 4(YBa2Cu3O7-x) + (1/2 - 3/2-delta + 2x)O2 reversible 2Y2BaCuO5 + 3Ba2Cu3O6-delta + CuO. At 800-degrees-C the equilibrium pressure for this reaction is slightly < 1 bar, and the enthalpy change is approximately 80-kJ/mol Y123. This result is not consistent with the conclusions drawn from some other studies of the stability of the superconducting Y-Ba-Cu-O compounds, and the differences are discussed. C1 OAK RIDGE NATL LAB,DIV CHEM,OAK RIDGE,TN 37831. OAK RIDGE NATL LAB,DIV CHEM TECHNOL,OAK RIDGE,TN 37831. RP WILLIAMS, RK (reprint author), OAK RIDGE NATL LAB,DIV MET & CERAM,POB 2008,OAK RIDGE,TN 37831, USA. RI Specht, Eliot/A-5654-2009 OI Specht, Eliot/0000-0002-3191-2163 NR 23 TC 37 Z9 37 U1 0 U2 1 PU AMER INST PHYSICS PI WOODBURY PA CIRCULATION FULFILLMENT DIV, 500 SUNNYSIDE BLVD, WOODBURY, NY 11797-2999 SN 0021-8979 J9 J APPL PHYS JI J. Appl. Phys. PD JUL 15 PY 1991 VL 70 IS 2 BP 906 EP 913 DI 10.1063/1.349597 PG 8 WC Physics, Applied SC Physics GA FY341 UT WOS:A1991FY34100055 ER PT J AU VINOGRADOV, SN SHARMA, PK QABAR, AN WALL, JS WESTRICK, JA SIMMONS, JH GILL, SJ AF VINOGRADOV, SN SHARMA, PK QABAR, AN WALL, JS WESTRICK, JA SIMMONS, JH GILL, SJ TI A DODECAMER OF GLOBIN CHAINS IS THE PRINCIPAL FUNCTIONAL SUBUNIT OF THE EXTRACELLULAR HEMOGLOBIN OF LUMBRICUS-TERRESTRIS SO JOURNAL OF BIOLOGICAL CHEMISTRY LA English DT Article ID TRANSMISSION ELECTRON-MICROSCOPE; AMINO-ACID-SEQUENCE; EARTHWORM ERYTHROCRUORIN; QUATERNARY STRUCTURE; OXYGEN BINDING; DISSOCIATION; PH; CHLOROCRUORINS; REASSOCIATION; PROTEIN AB Repeated dissociation of the approximately 3600-kDa hexagonal bilayer extracellular hemoglobin of Lumbricus terrestris in 4 m urea followed by gel filtration at neutral pH produces a subunit that retains the oxygen affinity of the native molecule (approximately 12 torr), but only two-thirds of the cooperativity (n(max) = 2.1 +/- 0.2 versus 3.3 +/- 0.3). The mass of this subunit was estimated to be 202 +/- 15 kDa by gel filtration and 202 +/- 26 kDa from mass measurements of unstained freeze-dried specimens by scanning transmission electron microscopy. Sodium dodecyl sulfate-polyacrylamide gel electrophoresis of this subunit showed that it consists predominantly of the heme-containing subunits M (chain I, 17 kDa) and T (disulfide-bonded chains II-IV, 50 kDa). Mixing of subunits M and T isolated concurrently with the 200-kDa subunit resulted in partial association into particles that had a mass of 191 +/- 13 kDa determined by gel filtration and 200 +/- 38 kDa determined by scanning transmission electron microscopy and whose oxygen affinity and cooperativity were the same as those of the 200-kDa subunit. The results imply that the 200-kDa subunit is a dodecamer of globin chains, consisting of three copies each of subunits M and T (3 x chains (I + II + Ill + IV)), in good agreement with the mass of 209 kDa calculated from the amino acid sequences of the four chains, and represents the largest functional subunit of Lumbricus hemoglobin. Twelve copies of this subunit would account for two-thirds of the total mass of the molecule, as suggested earlier (Vinogradov, S. N., Lugo, S. L., Mainwaring, M. G., Kapp, 0. H., and Crewe, A. V. (1986) Proc. Natl. Acad. Sci. U. S. A. 83, 8034-8038). The retention of only partial cooperativity by the 200-kDa subunit implies that full cooperativity is dependent on the presence of a complete hexagonal bilayer structure, wherein 12 200-kDa subunits are linked together by approximately 30-kDa heme-deficient chains. C1 BROOKHAVEN NATL LAB,DEPT BIOL,UPTON,NY 11973. UNIV COLORADO,DEPT CHEM & BIOCHEM,BOULDER,CO 80303. RP VINOGRADOV, SN (reprint author), WAYNE STATE UNIV,SCH MED,DEPT BIOCHEM,DETROIT,MI 48201, USA. FU NCRR NIH HHS [RR01777]; NHLBI NIH HHS [HL22325]; NIDDK NIH HHS [DK38674] NR 49 TC 58 Z9 58 U1 0 U2 0 PU AMER SOC BIOCHEMISTRY MOLECULAR BIOLOGY INC PI BETHESDA PA 9650 ROCKVILLE PIKE, BETHESDA, MD 20814 SN 0021-9258 J9 J BIOL CHEM JI J. Biol. Chem. PD JUL 15 PY 1991 VL 266 IS 20 BP 13091 EP 13096 PG 6 WC Biochemistry & Molecular Biology SC Biochemistry & Molecular Biology GA FX132 UT WOS:A1991FX13200048 PM 2071593 ER PT J AU WIEDMANN, RT GRANT, ER TONKYN, RG WHITE, MG AF WIEDMANN, RT GRANT, ER TONKYN, RG WHITE, MG TI HIGH-RESOLUTION THRESHOLD PHOTOIONIZATION OF N2O SO JOURNAL OF CHEMICAL PHYSICS LA English DT Article ID PHOTOELECTRON-SPECTROSCOPY; EMISSION-SPECTRUM; SELECTION-RULES; IONIZATION; ION; ENERGY; STATE; DISSOCIATION; OXIDE; HBR+ AB Pulsed field ionization (PFI) has been used in conjunction with a coherent vuv source to obtain high-resolution threshold photoelectron spectra for the (000), (010), (020), and (100) vibrational states of the N2O+ cation. Simulations for the rotational profiles of each vibronic level were obtained by fitting the Buckingham-Orr-Sichel equations [A. D. Buckingham, B. J. Orr, and J. M. Sichel, Philos. Trans. R. Soc. London, Ser. A 268, 147 (1970)] using accurate spectroscopic constants for the ground states of the neutral and the ion. The relative branch intensities are interpreted in terms of the partial waves of the outgoing photoelectron to which the ionic core is coupled and in terms of the angular momentum transferred to the core. The PFI technique also allows us to report an improved value for the ionization potential of N2O of 103 963 +/- 5 cm-1. C1 BROOKHAVEN NATL LAB,DEPT CHEM,UPTON,NY 11973. RP WIEDMANN, RT (reprint author), PURDUE UNIV,DEPT CHEM,W LAFAYETTE,IN 47907, USA. NR 38 TC 56 Z9 56 U1 0 U2 11 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 JUL 15 PY 1991 VL 95 IS 2 BP 746 EP 753 DI 10.1063/1.461080 PG 8 WC Chemistry, Physical; Physics, Atomic, Molecular & Chemical SC Chemistry; Physics GA FV976 UT WOS:A1991FV97600003 ER PT J AU NOURBAKHSH, S NORWOOD, K YIN, HM LIAO, CL NG, CY AF NOURBAKHSH, S NORWOOD, K YIN, HM LIAO, CL NG, CY TI VACUUM ULTRAVIOLET PHOTODISSOCIATION AND PHOTOIONIZATION STUDIES OF CH3SH AND SH SO JOURNAL OF CHEMICAL PHYSICS LA English DT Article ID METASTABLE ION CHARACTERISTICS; PHOTOELECTRON COINCIDENCE; COLLISIONAL ACTIVATION; METHANETHIOL; SULFUR; PHOTOFRAGMENTATION; THIOFORMALDEHYDE; FRAGMENTATION; DISSOCIATION; ETHANETHIOL AB The kinetic energy releases of the photodissociation processes, CH3SH + h-nu (193 nm) --> CH3 + SH, CH3S + H, and CH2S + H-2, have been measured using the time-of-flight mass spectrometric method. These measurements allow the direct determination of the dissociation energies for the CH3-SH and CH3S-H bonds at 0 K as 72.4 +/- 1.5 and 90 +/- 2 kcal/mol, respectively. The further dissociation of SH according to the process SH + h-nu (193 nm) --> S + H has also been observed. The appearance energy (AE) of S produced in the latter process is consistent with the formation of S(3P) + H. The photoelectron-photoion coincidence (PEPICO) spectra for CH3SH+, CH3S+ (or CH2SH+), and CH2S+ from CH3SH have been measured in the wavelength range of 925-1460 angstrom. The PEPICO measurements make possible the construction of the breakdown diagram for the unimolecular decomposition of internal-energy-selected CH3SH+ in the range of 0-83 kcal/mol. The AE measured for CH2S+ is consistent with the conclusion that the activation energy is negligible for 1,2-H-2 elimination from CH3SH+. C1 IOWA STATE UNIV SCI & TECHNOL,DEPT CHEM,AMES,IA 50011. RP NOURBAKHSH, S (reprint author), IOWA STATE UNIV SCI & TECHNOL,US DOE,AMES LAB,AMES,IA 50011, USA. NR 42 TC 68 Z9 72 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 JUL 15 PY 1991 VL 95 IS 2 BP 946 EP 954 DI 10.1063/1.461103 PG 9 WC Chemistry, Physical; Physics, Atomic, Molecular & Chemical SC Chemistry; Physics GA FV976 UT WOS:A1991FV97600027 ER PT J AU HOLCOMBE, CE DYKES, NL AF HOLCOMBE, CE DYKES, NL TI MICROWAVE SINTERING OF TITANIUM DIBORIDE SO JOURNAL OF MATERIALS SCIENCE LA English DT Article AB Using a 2.45 GHz, 6 kW microwave furnace adapted for inert gas sintering, titanium diboride (TiB2) can be rapidly microwave-sintered to > 90% of theoretical density with sintering temperatures of 1900 to 2100-degrees-C and soak times of 30 min or less. Densification behaviour with low-level additives was evaluated; 3 wt% chromium diboride (CrB2) was an excellent sintering aid-grain growth inhibitor. A special covering system was required to produce oxide-free TiB2. Specimen surface and interior temperatures were determined with a "hole experiment". Comparison with conventional sintering indicates that microwave sintering of TiB2-3 wt% CrB2 occurs at lower temperatures (i.e., 200-degrees-C lower) and can yield material with improved hardness, grain size, and fracture toughness. RP HOLCOMBE, CE (reprint author), OAK RIDGE Y-12 PLANT,POB 2009,OAK RIDGE,TN 37831, USA. NR 10 TC 31 Z9 34 U1 0 U2 4 PU CHAPMAN HALL LTD PI LONDON PA 2-6 BOUNDARY ROW, LONDON, ENGLAND SE1 8HN SN 0022-2461 J9 J MATER SCI JI J. Mater. Sci. PD JUL 15 PY 1991 VL 26 IS 14 BP 3730 EP 3738 DI 10.1007/BF01184963 PG 9 WC Materials Science, Multidisciplinary SC Materials Science GA FY705 UT WOS:A1991FY70500006 ER PT J AU WAGH, AS POEPPEL, RB SINGH, JP AF WAGH, AS POEPPEL, RB SINGH, JP TI OPEN PORE DESCRIPTION OF MECHANICAL-PROPERTIES OF CERAMICS SO JOURNAL OF MATERIALS SCIENCE LA English DT Article ID BRITTLE SOLIDS; YOUNG MODULUS; POROSITY; STRENGTH; ALUMINA; OXIDE; VOIDS AB A dependence of Young s modulus of elasticity on open porosity in ceramics is derived from an open-porosity model, which in the literature, is applied to salinity conductivity and fluid permeability in rocks. A random distribution of grain and pore size is assumed. The relation developed, E(p) = E0(1 - p)m, where E is the modulus of elasticity of the porous ceramic, E0 is the theoretical elastic modulus, p is the porosity and m is an exponent dependent on the tortuosity of the structure of the ceramic, adequately describes the dependence of the modulus of elasticity on porosity. The model is applied to the experimental data from several ceramics such as alumina, silicon nitride, silicon carbide, uranium oxide, rare-earth oxides, and YBa2Cu3O7-delta superconductor, and the value of m is obtained for each case. We have shown that m has a value of nearly 2 for sintered ceramics, unless sintering aids or hot pressing have been used during fabrication of the ceramic. Such additional procedures approximately double the magnitude of m. C1 UNIV W INDIES, DEPT PHYS, MAT LAB, KINGSTON 7, JAMAICA. RP ARGONNE NATL LAB, DIV MAT & COMPONENTS TECHNOL, ARGONNE, IL 60439 USA. OI Wagh, Arun/0000-0002-8678-7574 NR 43 TC 75 Z9 77 U1 2 U2 28 PU SPRINGER PI NEW YORK PA 233 SPRING ST, NEW YORK, NY 10013 USA SN 0022-2461 EI 1573-4803 J9 J MATER SCI JI J. Mater. Sci. PD JUL 15 PY 1991 VL 26 IS 14 BP 3862 EP 3868 DI 10.1007/BF01184983 PG 7 WC Materials Science, Multidisciplinary SC Materials Science GA FY705 UT WOS:A1991FY70500026 ER PT J AU SKYLLINGSTAD, ED AF SKYLLINGSTAD, ED TI CRITICAL LAYER EFFECTS ON ATMOSPHERIC SOLITARY AND CNOIDAL WAVES SO JOURNAL OF THE ATMOSPHERIC SCIENCES LA English DT Article ID GRAVITY-WAVE; BOUNDARY-CONDITION; SHEAR-FLOW; INSTABILITY; CONVECTION; MODEL; OVERREFLECTION; SIMULATION AB The interactions of atmospheric cnoidal waves with a critical level are examined using a two-dimensional numerical model. A cnoidal wave system is generated by applying a bore initial condition to a shallow surface-based inversion; the system is analyzed using various profiles of stability and shear. Under neutral conditions a critical level is shown to cause wave reflection with wave growth, as indicated by the vertical velocity, when the stability is low. Increasing the ambient stability above the cnoidal wave leads to a reduction in the reflective properties of the critical level and an increase in critical level absorption. The division between wave growth and wave decay occurs near a critical level Richardson's number of 0.25 agreeing with instability theory. When a variable profile of stability is assumed, with stable regions both below and above the critical layer and weak stability at the critical level region, the cnoidal wave system again amplifies, but not as strongly. The results conform with past analytical results pertaining to the atmospheric structure required for wave reflection and absorption. However, the occurrence of overreflection cannot be diagnosed from the simulations because of the strongly nonlinear, unsteady behavior of the cnoidal wave systems. RP SKYLLINGSTAD, ED (reprint author), PACIFIC NW LAB, POB 999, RICHLAND, WA 99352 USA. NR 33 TC 13 Z9 13 U1 0 U2 0 PU AMER METEOROLOGICAL SOC PI BOSTON PA 45 BEACON ST, BOSTON, MA 02108-3693 SN 0022-4928 J9 J ATMOS SCI JI J. Atmos. Sci. PD JUL 15 PY 1991 VL 48 IS 14 BP 1613 EP 1624 DI 10.1175/1520-0469(1991)048<1613:CLEOAS>2.0.CO;2 PG 12 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA GB986 UT WOS:A1991GB98600001 ER PT J AU RAO, KTV BUCCI, RJ JATA, KV RITCHIE, RO AF RAO, KTV BUCCI, RJ JATA, KV RITCHIE, RO TI A COMPARISON OF FATIGUE-CRACK PROPAGATION BEHAVIOR IN SHEET AND PLATE ALUMINUM LITHIUM ALLOYS SO MATERIALS SCIENCE AND ENGINEERING A-STRUCTURAL MATERIALS PROPERTIES MICROSTRUCTURE AND PROCESSING LA English DT Article ID AL-LI ALLOY; GROWTH; TOUGHNESS AB The influence of wrought product form on the fatigue-crack propagation resistance of aluminum-lithium alloys was examined; specifically, results on the growth kinetics of long (greater than 10 mm) fatigue cracks in peak-aged Al-Li-Cu-Zr 2090-T8X and Al-Li-Cu-Mg-Zr 2091-T8 alloys, fabricated as sheet and plate, are presented as a function of microstructure, load ratio and specimen orientation. Contrary to popular belief, it was found that fatigue-crack growth rates at equivalent stress intensity levels are significantly faster and less dependent on specimen orientation in sheet than in plate. Such differences are attributed to the prominent role of crack-tip shielding during fatigue in these alloys, resulting from crack deflection and consequent crack closure from wedging of fracture-surface asperities, which microstructurally is related to variations in the degree of recrystallization, grain morphology and texture between the two product forms. C1 UNIV CALIF BERKELEY,DEPT MAT SCI & MINERAL ENGN,BERKELEY,CA 94720. ALCOA LABS,ALCOA CTR,PA 15069. UNIV DAYTON,RES INST,DAYTON,OH 45469. RP RAO, KTV (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 27 TC 16 Z9 16 U1 0 U2 6 PU ELSEVIER SCIENCE SA LAUSANNE PI LAUSANNE 1 PA PO BOX 564, 1001 LAUSANNE 1, SWITZERLAND SN 0921-5093 J9 MAT SCI ENG A-STRUCT JI Mater. Sci. Eng. A-Struct. Mater. Prop. Microstruct. Process. PD JUL 15 PY 1991 VL 141 IS 1 BP 39 EP 48 PG 10 WC Nanoscience & Nanotechnology; Materials Science, Multidisciplinary; Metallurgy & Metallurgical Engineering SC Science & Technology - Other Topics; Materials Science; Metallurgy & Metallurgical Engineering GA GC548 UT WOS:A1991GC54800004 ER PT J AU WRIGHT, RN KNIBLOE, JR NOEBE, RD AF WRIGHT, RN KNIBLOE, JR NOEBE, RD TI CONSOLIDATION OF NIAL POWDERS USING HOT ISOSTATIC PRESSING SO MATERIALS SCIENCE AND ENGINEERING A-STRUCTURAL MATERIALS PROPERTIES MICROSTRUCTURE AND PROCESSING LA English DT Article ID DENSIFICATION; DIFFUSION; DIAGRAMS AB Consolidation of stoichiometric NiAl powder during hot isostatic pressing (HIP) and the rate controlling densification mechanisms were modeled through the development of HIP maps. Using the best available data for material behavior and diffusion characteristics from the literature and experiments, maps were developed which describe densification of monosized powders as a function of HIP time, temperature and pressure. There is good agreement between the final densities predicted from the model and those observed experimentally. C1 NASA,LEWIS RES CTR,CLEVELAND,OH 44135. RP WRIGHT, RN (reprint author), EG&G IDAHO INC,IDAHO NATL ENGN LAB,IDAHO FALLS,ID 83415, USA. NR 20 TC 6 Z9 6 U1 1 U2 3 PU ELSEVIER SCIENCE SA LAUSANNE PI LAUSANNE 1 PA PO BOX 564, 1001 LAUSANNE 1, SWITZERLAND SN 0921-5093 J9 MAT SCI ENG A-STRUCT JI Mater. Sci. Eng. A-Struct. Mater. Prop. Microstruct. Process. PD JUL 15 PY 1991 VL 141 IS 1 BP 79 EP 83 DI 10.1016/0921-5093(91)90711-U PG 5 WC Nanoscience & Nanotechnology; Materials Science, Multidisciplinary; Metallurgy & Metallurgical Engineering SC Science & Technology - Other Topics; Materials Science; Metallurgy & Metallurgical Engineering GA GC548 UT WOS:A1991GC54800010 ER PT J AU PATTERSON, FG GONZALES, R PERRY, MD AF PATTERSON, FG GONZALES, R PERRY, MD TI COMPACT 10-TW, 800-FS ND-GLASS LASER SO OPTICS LETTERS LA English DT Article ID CHIRPED-PULSE AMPLIFICATION; STIMULATED RAMAN-SCATTERING; GROUP-VELOCITY DISPERSION; COMPRESSION; COMPENSATION AB A tabletop Nd:phosphate glass laser system capable of producing a focused intensity in excess of 10(18) W/cm2 is described. Optimization of chirped-pulse amplification, including spectral shaping and careful attention to beam quality, produces a transform-limited, 800-fs compressed pulse with a peak power of > 10 TW in a near-diffraction-limited spatially uniform beam. RP PATTERSON, FG (reprint author), UNIV CALIF LAWRENCE LIVERMORE NATL LAB,LASER PROGRAM,MC L-490,LIVERMORE,CA 94550, USA. NR 17 TC 71 Z9 71 U1 0 U2 3 PU OPTICAL SOC AMER PI WASHINGTON PA 2010 MASSACHUSETTS AVE NW, WASHINGTON, DC 20036 SN 0146-9592 J9 OPT LETT JI Opt. Lett. PD JUL 15 PY 1991 VL 16 IS 14 BP 1107 EP 1109 DI 10.1364/OL.16.001107 PG 3 WC Optics SC Optics GA FX982 UT WOS:A1991FX98200018 PM 19776891 ER PT J AU LINDEMER, TB WASHBURN, FA MACDOUGALL, CS FEENSTRA, R CAVIN, OB AF LINDEMER, TB WASHBURN, FA MACDOUGALL, CS FEENSTRA, R CAVIN, OB TI DECOMPOSITION OF YBA2CU3O7-X AND YBA2CU4O8 FOR RHO-OMICRON-LESS-THAN-OR-EQUAL-TO-0.1 MPA SO PHYSICA C LA English DT Article ID BA-CU OXIDES; OXYGEN-PRESSURE; LIQUIDUS RELATIONS; PHASE-EQUILIBRIA; O SYSTEM; STABILITY; SUPERCONDUCTORS; DIAGRAMS; GROWTH AB The temperature and oxygen pressure conditions were determined by thermogravimetry for decomposition of phase-pure YBa2Cu3O7-x and YBa2Cu4O8 from 3 Pa to 0.1 MPA O2. All extant data were reviewed to determine the conditions for thermodynamic stability of phase-pure YBa2Cu3O7-x and for compositions lying between YBa2Cu3O7-x and CuO. Thermodynamic values for YBa2Cu4O8 were derived, as was the 123-CuO section of the Y2O3-BaO-CuO phase diagram. C1 OAK RIDGE NATL LAB,DIV ANALYT CHEM,OAK RIDGE,TN 37831. OAK RIDGE NATL LAB,DIV SOLID STATE,OAK RIDGE,TN 37831. OAK RIDGE NATL LAB,DIV MET & CERAM,OAK RIDGE,TN 37831. RP LINDEMER, TB (reprint author), OAK RIDGE NATL LAB,DIV CHEM TECHNOL,POB 2008,OAK RIDGE,TN 37831, USA. NR 47 TC 96 Z9 97 U1 0 U2 7 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0921-4534 J9 PHYSICA C JI Physica C PD JUL 15 PY 1991 VL 178 IS 1-3 BP 93 EP 104 DI 10.1016/0921-4534(91)90163-S PG 12 WC Physics, Applied SC Physics GA GA444 UT WOS:A1991GA44400014 ER PT J AU KOTTMANN, A BURGAZY, F LAM, DJ FANG, Y LAMPARTER, P STEEB, S AF KOTTMANN, A BURGAZY, F LAM, DJ FANG, Y LAMPARTER, P STEEB, S TI PARTIAL DENSITIES OF STATES WITH POLARIZED OXYGEN K-ALPHA X-RAY-EMISSION OF YBA2CU3O7-DELTA SO PHYSICA C LA English DT Article ID HIGH-TC SUPERCONDUCTOR; SINGLE-CRYSTALS; PHOTOELECTRON; SPECTROSCOPY; ABSORPTION; OXIDES; BA; CU AB O K-alpha X-ray emission spectra of the high-T(c) superconductor YBa2Cu3O7-delta were evaluated in terms of the linear polarization along the x-, y- and z-direction. These partial spectra represent the electronic densities of states of the valence band with 2p(x)-, 2p(y)-and 2p(z)-like symmetry. The measurements which are representative for the bulk material were done by using an electron microprobe. The polarization factor of the spectrometer crystal was determined. The O 2p(x)- and O 2p(y)-spectra show a main peak at a binding energy of 1.80 eV and a shoulder at about 4.3 eV as well as a band width of about 8 eV. They differ for binding energies around the shoulder. The O 2p(z) spectrum which represents the density of states resulting from oxygen p-orbitals perpendicular to the CuO2-planes shows a different shape, a lower integrated intensity, and a smaller energetic breadth compared with the O 2p(x)- and O 2p(y)-spectra. The agreement between recently calculated partial densities of states and the measured X-ray emission spectra is satisfactory. C1 ARGONNE NATL LAB,DIV MAT SCI,ARGONNE,IL 60439. RP KOTTMANN, A (reprint author), MAX PLANCK INST MET RES,INST WERKSTOFFWISSENSCH,W-7000 STUTTGART 80,GERMANY. NR 23 TC 8 Z9 8 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 JUL 15 PY 1991 VL 178 IS 1-3 BP 125 EP 136 DI 10.1016/0921-4534(91)90167-W PG 12 WC Physics, Applied SC Physics GA GA444 UT WOS:A1991GA44400018 ER PT J AU SCHIRBER, JE OVERMYER, DL WANG, HH WILLIAMS, JM CARLSON, KD KINI, AM WELP, U KWOK, WK AF SCHIRBER, JE OVERMYER, DL WANG, HH WILLIAMS, JM CARLSON, KD KINI, AM WELP, U KWOK, WK TI PRESSURE-DEPENDENCE OF THE SUPERCONDUCTING TRANSITION-TEMPERATURE OF POTASSIUM FULLERENE, KXC60 SO PHYSICA C LA English DT Article ID C-60 AB The pressure dependence of the superconducting transition temperature in K(x)C60 is determined using solid He pressure techniques to be dT(c)/dP = -0.63 +/- 0.08 K/kbar. Crude scaling would predict Rb(x)C60 and CSC60 to have T(c) values of approximately 35 and approximately 60 K, respectively. C1 ARGONNE NATL LAB,ARGONNE,IL 60439. RP SCHIRBER, JE (reprint author), SANDIA NATL LABS,ALBUQUERQUE,NM 87185, USA. RI Kini, Aravinda/F-4467-2012 NR 9 TC 50 Z9 50 U1 0 U2 6 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0921-4534 J9 PHYSICA C JI Physica C PD JUL 15 PY 1991 VL 178 IS 1-3 BP 137 EP 139 DI 10.1016/0921-4534(91)90168-X PG 3 WC Physics, Applied SC Physics GA GA444 UT WOS:A1991GA44400019 ER PT J AU CREAGH, SC LITTLEJOHN, RG AF CREAGH, SC LITTLEJOHN, RG TI SEMICLASSICAL TRACE FORMULAS IN THE PRESENCE OF CONTINUOUS SYMMETRIES SO PHYSICAL REVIEW A LA English DT Article ID PERIODIC-ORBITS; QUANTUM SPECTRA; BOUND SPECTRUM; WAVE-EQUATION; FINITE DOMAIN; QUANTIZATION; EIGENFREQUENCIES; MECHANICS; DENSITY; TERMS AB We derive generalizations of the semiclassical trace formula of Gutzwiller [J. Math. Phys. 12, 343 (1971)] and Balian and Bloch [Ann. Phys. 69, 76 (1972)] that are valid for systems exhibiting continuous symmetries. In particular, we consider symmetries for which the associated set of conserved quantities Poisson-commute. For these systems, the periodic orbits of a given energy occur in continuous families and the usual trace formula, which is valid only when the periodic orbits of a given energy are isolated, does not apply. In the trace formulas we derive, the density of states is determined by a sum over continuous families of periodic orbits rather than a sum over individual periodic orbits. Like Gutzwiller's formula for isolated orbits, the sum involves intrinsic, canonically invariant properties of the periodic orbits. We illustrate the theory with two important special cases: axial symmetry and integrable systems. C1 UNIV CALIF BERKELEY,BERKELEY,CA 94720. RP CREAGH, SC (reprint author), UNIV CALIF BERKELEY LAWRENCE BERKELEY LAB,BERKELEY,CA 94720, USA. NR 28 TC 90 Z9 90 U1 1 U2 2 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 1050-2947 J9 PHYS REV A JI Phys. Rev. A PD JUL 15 PY 1991 VL 44 IS 2 BP 836 EP 850 DI 10.1103/PhysRevA.44.836 PG 15 WC Optics; Physics, Atomic, Molecular & Chemical SC Optics; Physics GA FY463 UT WOS:A1991FY46300010 ER PT J AU HIRSCHMUGL, CJ SAGURTON, M WILLIAMS, GP AF HIRSCHMUGL, CJ SAGURTON, M WILLIAMS, GP TI MULTIPARTICLE COHERENCE CALCULATIONS FOR SYNCHROTRON-RADIATION EMISSION SO PHYSICAL REVIEW A LA English DT Article ID ELECTRON STORAGE-RINGS AB We have used Monte Carlo calculations to verify the classical electrodynamics result describing the multiparticle coherent enhancement at long wavelengths for synchrotron-radiation emission. In addition we show the derivation of the result that, for a bunch of electrons in a storage ring, the synchrotron-radiation emission has a multiparticle coherent enhancement that is given by the square of the Fourier transform of the longitudinal spatial distribution function of the electrons. The result has been verified for Gaussian and sinusoidal distributions. For a Gaussian distribution of particles in a bunch, this is seen to have an effect only at wavelengths close to the bunch length. For a sinusoidal distribution as in the transverse optical klystron, the enhancement can easily be seen to occur at one specific wavelength. C1 BROOKHAVEN NATL LAB,NATL SYNCHROTRON LIGHT SOURCE,UPTON,NY 11973. RP HIRSCHMUGL, CJ (reprint author), YALE UNIV,DEPT APPL PHYS,NEW HAVEN,CT 06520, USA. NR 8 TC 72 Z9 72 U1 1 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 JUL 15 PY 1991 VL 44 IS 2 BP 1316 EP 1320 DI 10.1103/PhysRevA.44.1316 PG 5 WC Optics; Physics, Atomic, Molecular & Chemical SC Optics; Physics GA FY463 UT WOS:A1991FY46300060 ER PT J AU DRALLOS, PJ RILEY, ME AF DRALLOS, PJ RILEY, ME TI SEPARATION-OF-VARIABLES APPROXIMATION TO THE BOLTZMANN-EQUATION SO PHYSICAL REVIEW A LA English DT Note ID EVOLUTION AB We have tested a separation-of-variables approximation for the electron velocity distribution function in the Boltzmann equation. In this approximation, the distribution function f(e)(z, v(z), v(r), t) is represented as the product of two functions F(z, v(z), t) and G(z, v(r), t). This approximation can represent very anisotropic distributions, while effectively reducing the dimensionality of the calculation. We have implemented this approximation using a method of characteristics, and have applied it to argon and neon gas for a wide range of applied electric fields. RP DRALLOS, PJ (reprint author), SANDIA NATL LABS,ALBUQUERQUE,NM 87185, USA. NR 5 TC 0 Z9 0 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 JUL 15 PY 1991 VL 44 IS 2 BP 1405 EP 1408 DI 10.1103/PhysRevA.44.1405 PG 4 WC Optics; Physics, Atomic, Molecular & Chemical SC Optics; Physics GA FY463 UT WOS:A1991FY46300072 ER PT J AU BUTLER, WH ZHANG, XG AF BUTLER, WH ZHANG, XG TI ACCURACY AND CONVERGENCE PROPERTIES OF MULTIPLE-SCATTERING THEORY IN 3 DIMENSIONS SO PHYSICAL REVIEW B LA English DT Article ID EXACT EIGENVALUE EQUATION; MUFFIN-TIN POTENTIALS; INFINITE COLLECTION; VALIDITY; FINITE AB We present a numerical and analytical study of the accuracy and convergence properties of multiple-scattering theory (MST) in three dimensions. The convergence with respect to the number of angular momentum states, l(max), of the solutions to the three-dimensional MST equations for two muffin-tin potentials is studied analytically and by means of numerical calculations. The rate of convergence appears to be a universal quantity which depends, in the limit of l(max) --> infinity, only on the separation between the scatterers relative to their radii. No evidence of error in the energy, the wave function, or the derivative of the wave function in the limit l(max) --> infinity is found. In numerical tests which use square-well potentials and truncated Coulomb potentials it is found that the accuracy of the calculated wave functions and their derivatives is limited by the precision with which real numbers can be represented on the digital computers available to the authors (approximately one part in 10(28)) rather than by postulated errors inherent in MST. Analytic formulas, valid in the limit of large l(max), for the residual errors in the solutions of the MST equations indicate that these errors vanish in the limit l(max) --> infinity. These results are inconsistent with the claim of Badralexe and Freeman [Phys. Rev. B 37, 10469 (1988); 41, 10226 (1990)] that multiple-scattering theory does not yield exact solutions to the wave equation for muffin-tin potentials. C1 UNIV CALIF LAWRENCE LIVERMORE NATL LAB,DEPT CHEM & MAT SCI,LIVERMORE,CA 94550. RP BUTLER, WH (reprint author), OAK RIDGE NATL LAB,DIV MET & CERAM,POB 2008,OAK RIDGE,TN 37831, USA. NR 14 TC 6 Z9 8 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 JUL 15 PY 1991 VL 44 IS 3 BP 969 EP 983 DI 10.1103/PhysRevB.44.969 PG 15 WC Physics, Condensed Matter SC Physics GA FW105 UT WOS:A1991FW10500004 ER PT J AU KURTZ, SR BIEFELD, RM AF KURTZ, SR BIEFELD, RM TI INFRARED MAGNETOOPTICAL AND PHOTOLUMINESCENCE STUDIES OF THE ELECTRONIC-PROPERTIES OF IN(AS,SB) STRAINED-LAYER SUPERLATTICES SO PHYSICAL REVIEW B LA English DT Article ID BAND-STRUCTURE; QUANTUM WELLS; DETECTOR AB Long-wavelength magnetotransmission and photoluminescence measurements were performed on InAs0.13Sb0.87/InSb strained-layer superlattices (SLS's). The energies and reduced effective masses of several interband optical transitions were obtained from these experiments. SLS's with different layer thicknesses produced self-consistent results. With these data, the type-II band offset and band-edge strain-shift parameters were accurately determined. Consistent with a type-II offset, an extremely small, in-plane effective-mass hole ground state was observed, thus proving that the hole quantum well is located in the biaxially compressed, InSb layer. Nonparabolicity, suggesting valence-band anticrossing, was also observed. RP KURTZ, SR (reprint author), SANDIA NATL LABS,ALBUQUERQUE,NM 87185, USA. NR 21 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 JUL 15 PY 1991 VL 44 IS 3 BP 1143 EP 1149 DI 10.1103/PhysRevB.44.1143 PG 7 WC Physics, Condensed Matter SC Physics GA FW105 UT WOS:A1991FW10500026 ER PT J AU BAIN, JA CHYUNG, LJ BRENNAN, S CLEMENS, BM AF BAIN, JA CHYUNG, LJ BRENNAN, S CLEMENS, BM TI ELASTIC STRAINS AND COHERENCY STRESSES IN MO/NI MULTILAYERS SO PHYSICAL REVIEW B LA English DT Article ID SUPER-LATTICES; SURFACE STRESS; METAL-FILMS; THIN-FILMS; SUPERLATTICES; ANOMALIES; DYNAMICS; EPITAXY; GROWTH; PHASE AB The observed expansion in the out-of-plane lattice parameter in metal multilayers can be produced by elastic strains, bulk relaxation, or interface dilatation. Each can produce the observed out-of-plane result but will differ in their in-plane lattice-parameter behavior. We perform a complete strain determination in Mo/Ni multilayers, using grazing-incidence and asymmetric x-ray diffraction as well as substrate-curvature-stress measurements, and determine that elastic strains dominate. Assuming Nishiyama-Wasserman epitaxial orientation, we were able to calculate the complete stress state in both materials. The stresses, which arise from substrate interaction and coherency between the bcc Mo and fcc Ni layers, increase as the bilayer period is decreased. We find remarkable agreement between the substrate-interaction stresses calculated from x-ray strain measurements and those measured using wafer-curvature techniques; this shows that interface contraction stresses are not significant. We found no evidence for interface dilatation strains. Furthermore, the small changes that are observed in the unstrained lattice parameters can be ascribed to alloying rather than bulk relaxation. C1 STANFORD SYNCHROTRON RADIAT LAB, STANFORD, CA 94309 USA. RP BAIN, JA (reprint author), STANFORD UNIV, DEPT MAT SCI & ENGN, STANFORD, CA 94305 USA. OI Bain, James/0000-0002-5355-5048 NR 23 TC 61 Z9 61 U1 0 U2 5 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 JUL 15 PY 1991 VL 44 IS 3 BP 1184 EP 1192 DI 10.1103/PhysRevB.44.1184 PG 9 WC Physics, Condensed Matter SC Physics GA FW105 UT WOS:A1991FW10500032 ER PT J AU WANG, LQ VONWITTENAU, AES JI, ZG WANG, LS HUANG, ZQ SHIRLEY, DA AF WANG, LQ VONWITTENAU, AES JI, ZG WANG, LS HUANG, ZQ SHIRLEY, DA TI C(2X2)CL/CU(001) ADSORBATE GEOMETRY AND SUBSTRATE-SURFACE RELAXATION USING LOW-TEMPERATURE ANGLE-RESOLVED PHOTOEMISSION EXTENDED FINE-STRUCTURE SO PHYSICAL REVIEW B LA English DT Article ID NORMAL PHOTOELECTRON DIFFRACTION; CU(001); NI(001); ATOM; CL AB A detailed structural study of the c(2X2)CI/Cu(001) adsorbate system was made, using the angle-resolved photoemission extended-fine-structure (ARPEFS) technique at low temperature, which yields both more accurate surface structural information and near-surface structural information for deeper substrate layers. Electrons were detected along two emission directions, [001] and [01 1], and at two temperatures, 110 and 300 K. The Cl atoms were found to adsorb in the fourfold hollow site, 1.604(5) angstrom above the first copper layer, with a Cl - Cu bond length of 2.416(3) angstrom (in which the errors in parentheses are statistical standard deviations only). These values are in excellent agreement with a previous low-energy electron-diffraction study by Jona et al. The c (2 X 2)Cl-covered first copper layer showed no relaxation with respect to the bulk position. However, a small corrugation of the second copper layer was found: The second-layer copper atoms below the Cl atoms move 0.042(12) angstrom away from the surface, while those in open positions remain in their bulk positions. The distances from the Cl atoms to the third and fourth copper layers were found to be 5.222(25) and 7.023(22) angstrom, respectively, yielding a bulk-like interlayer spacing. Thus the depth sensitivity of the low-temperature ARPEFS facilitated definitive referencing of near-surface atomic positions to the underlying lattice. C1 UNIV CALIF BERKELEY LAWRENCE BERKELEY LAB,DIV CHEM SCI,BERKELEY,CA 94720. RP WANG, LQ (reprint author), UNIV CALIF BERKELEY,DEPT CHEM,BERKELEY,CA 94720, USA. NR 34 TC 51 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 JUL 15 PY 1991 VL 44 IS 3 BP 1292 EP 1305 DI 10.1103/PhysRevB.44.1292 PG 14 WC Physics, Condensed Matter SC Physics GA FW105 UT WOS:A1991FW10500044 ER PT J AU NORMAN, MR AF NORMAN, MR TI CRYSTAL-FIELD POLARIZATION AND THE INSULATING GAP IN FEO, COO, NIO, AND LA2CUO4 SO PHYSICAL REVIEW B LA English DT Note ID TRANSITION-METAL OXIDES; ORBITAL POLARIZATION AB An orbital-polarization correction to local-spin-density (LSD) theory is developed in a crystal-field basis, and applied to FeO, CoO, NiO, and La2CUO4. The result is a substantial enhancement of the LSD band gap for NiO, and the creation of an insulating ground state for FeO, CoO, and La2CU04. RP NORMAN, MR (reprint author), ARGONNE NATL LAB,DIV MAT SCI,ARGONNE,IL 60439, USA. RI Norman, Michael/C-3644-2013 NR 11 TC 39 Z9 39 U1 0 U2 6 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 0163-1829 J9 PHYS REV B JI Phys. Rev. B PD JUL 15 PY 1991 VL 44 IS 3 BP 1364 EP 1367 DI 10.1103/PhysRevB.44.1364 PG 4 WC Physics, Condensed Matter SC Physics GA FW105 UT WOS:A1991FW10500057 ER PT J AU FISCHER, DA WENTZCOVITCH, RM CARR, RG CONTINENZA, A FREEMAN, AJ AF FISCHER, DA WENTZCOVITCH, RM CARR, RG CONTINENZA, A FREEMAN, AJ TI GRAPHITIC INTERLAYER STATES - A CARBON-K NEAR-EDGE X-RAY-ABSORPTION FINE-STRUCTURE STUDY SO PHYSICAL REVIEW B LA English DT Note ID ELECTRONIC-PROPERTIES; PREDICTION; BAND AB We have measured the carbon K near-edge x-ray-absorption fine structure of graphite by transmission, electron yield, and fluorescence yield. A rounded and prominent peak is identified in the near-edge spectrum, among the other well-known spectral features. With the aid of a full-potential linearized augmented-plane-wave band calculation, this feature is interpreted as originating from interlayer states in low-symmetry regions of the Brillouin zone. This finding is relevant to interpreting the near-edge structure of graphite intercalation compounds specially of the alkali-metal type. C1 BROOKHAVEN NATL LAB,DEPT PHYS,UPTON,NY 11973. STANFORD SYNCHROTRON RADIAT LAB,STANFORD,CA 94309. NORTHWESTERN UNIV,DEPT PHYS & ASTRON,EVANSTON,IL 60208. NORTHWESTERN UNIV,MAT RES CTR,EVANSTON,IL 60208. RP FISCHER, DA (reprint author), BROOKHAVEN NATL LAB,EXXON PARTICIPATING RES TEAM,UPTON,NY 11973, USA. RI Continenza, Alessandra/M-1919-2015; Wentzcovitch, Renata/J-8768-2015 OI Continenza, Alessandra/0000-0002-6169-2448; NR 22 TC 120 Z9 121 U1 1 U2 9 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 0163-1829 J9 PHYS REV B JI Phys. Rev. B PD JUL 15 PY 1991 VL 44 IS 3 BP 1427 EP 1429 DI 10.1103/PhysRevB.44.1427 PG 3 WC Physics, Condensed Matter SC Physics GA FW105 UT WOS:A1991FW10500073 ER PT J AU FREERICKS, JK FALICOV, LM ROKHSAR, DS AF FREERICKS, JK FALICOV, LM ROKHSAR, DS TI EXACT-SOLUTIONS OF FRUSTRATED ORDINARY AND CHIRAL 8-SITE HUBBARD MODELS SO PHYSICAL REVIEW B LA English DT Article ID T-J MODEL; RESONATING-VALENCE-BOND; GROUND-STATE PROPERTIES; LARGE-N LIMIT; EXACT-DIAGONALIZATION; HEISENBERG-MODEL; HOLE DYNAMICS; T/U EXPANSION; FLUX PHASES; SUPERCONDUCTIVITY AB This contribution addresses the question of whether or not the ground state of a frustrated spin-1/2 Heisenberg model can be smoothly related to the ground state of a simple tight-binding model at half-filling in an appropriately chosen magnetic field. This continuity is considered explicitly for an eight-site square-lattice Hubbard model with nearest- and next-nearest-neighbor hopping, which approaches a frustrated Heisenberg model with nearest- and next-nearest-neighbor antiferromagnetic exchange coupling in the limit of large Hubbard U. In addition, a counterexample to the widely held belief that the half-filled band of the ordinary Hubbard model is nonmagnetic has been found in the regime where the hopping parameters and Hubbard interaction are all the same order of magnitude. C1 UNIV CALIF BERKELEY LAWRENCE BERKELEY LAB, DIV MAT SCI, BERKELEY, CA 94720 USA. RP FREERICKS, JK (reprint author), UNIV CALIF BERKELEY, DEPT PHYS, BERKELEY, CA 94720 USA. RI Freericks, James/D-7502-2011; OI Freericks, James/0000-0002-6232-9165 NR 90 TC 10 Z9 10 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 JUL 15 PY 1991 VL 44 IS 4 BP 1458 EP 1474 DI 10.1103/PhysRevB.44.1458 PG 17 WC Physics, Condensed Matter SC Physics GA FY718 UT WOS:A1991FY71800002 ER PT J AU VALONE, SM AF VALONE, SM TI DENSITY AND ONE-MATRIX FUNCTIONALS GENERATED BY CONSTRAINED-SEARCH THEORY SO PHYSICAL REVIEW B LA English DT Article ID ELECTRON-DENSITIES; CORRELATION-ENERGY; GROUND-STATE; HARTREE-FOCK; 1 MATRICES; MOLECULES; EXCHANGE; APPROXIMATION; SOLIDS; METALS AB In principle, it is possible to construct analytical energy functionals of the electron density and the one-particle density matrix by using the constrained-search theory of Levy [Proc. Natl. Acad. Sci. U.S.A. 76, 6062 (1979)] to calculate the parameters in either model wave functions or two-particle density matrices. Illustrations are attempted through several specific examples. A very simple model set of two-particle matrices is shown to contain all forms of local exchange-correlation expressions for the electron-electron repulsion contribution to the total energy. A special feature of the model two-particle matrices is that they depend explicitly on the interelectronic distance. Constrained-search theory is used to derive values for the two parameters in the model two-particle matrices. The resulting functional shows promise for preserving charge distribution and bond directionality information absent in other functionals. A generalization of this model two-particle matrix allows derivation of a one-matrix functional, thereby skirting a common, implicit approximation in some local-density approximations to the total energy. Finally, outlines of constrained-search modifications to functionals due to Gunnarsson-Jones and to Colle and Salvetti illustrate the many possible variations of the central theme. For the Colle-Salvetti functional, a method is proposed that produces an N-representable total energy, rather than an electron-electron repulsion, functional, i.e., a functional based on a model wave function, and consequently obeys the variational principle for the true Hamiltonian system. RP UNIV CALIF LOS ALAMOS SCI LAB, DIV MAT SCI & TECHNOL, LOS ALAMOS, NM 87545 USA. NR 74 TC 15 Z9 15 U1 0 U2 2 PU AMER PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 1098-0121 EI 1550-235X J9 PHYS REV B JI Phys. Rev. B PD JUL 15 PY 1991 VL 44 IS 4 BP 1509 EP 1522 DI 10.1103/PhysRevB.44.1509 PG 14 WC Physics, Condensed Matter SC Physics GA FY718 UT WOS:A1991FY71800008 ER PT J AU AKIMOTO, K HIROSE, K MIZUKI, J AF AKIMOTO, K HIROSE, K MIZUKI, J TI STRUCTURE AT THE YB/GAAS INTERFACE STUDIED BY ANOMALOUS X-RAY-SCATTERING SO PHYSICAL REVIEW B LA English DT Article ID SCHOTTKY-BARRIER HEIGHT; GAAS(100) AB Different 4 X 1 superstructures are found for Yb/GaAs(001) contacts with different Yb thicknesses. To clarify the role of Yb atoms in the 4 X 1 structure, an x-ray anomalous-dispersion effect has been used in the grazing-incidence x-ray-diffraction geometry. Diffraction intensities measured in the x-ray energy range near the Yb L(III) absorption edge show a characteristic variation, which reflects the energy dependence of the real part of the anomalous scattering factor (f') for Yb atoms. As a result, for all the samples, Yb atoms are found to order in 4 X 1 structures. The arrangements of the Yb atoms in the 4 X 1 unit cell are derived from Buerger's decomposition method of the Patterson function. By comparison of the calculated diffraction intensities with observed intensities, two different (4 X 1) structural models for the thin and thick Yb-layer samples are found. Different Schottky-barrier-height values are also found for these samples. C1 BROOKHAVEN NATL LAB,UPTON,NY 11973. RP AKIMOTO, K (reprint author), NEC CORP LTD,FUNDAMENTAL RES LABS,TSUKUBA,IBARAKI 305,JAPAN. NR 10 TC 15 Z9 15 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 JUL 15 PY 1991 VL 44 IS 4 BP 1622 EP 1627 DI 10.1103/PhysRevB.44.1622 PG 6 WC Physics, Condensed Matter SC Physics GA FY718 UT WOS:A1991FY71800020 ER PT J AU BERNARD, JE ZUNGER, A AF BERNARD, JE ZUNGER, A TI STRAIN-ENERGY AND STABILITY OF SI-GE COMPOUNDS, ALLOYS, AND SUPERLATTICES SO PHYSICAL REVIEW B LA English DT Article ID SPECIAL-QUASIRANDOM-STRUCTURES; SEMICONDUCTOR SOLID-SOLUTIONS; SILICON-GERMANIUM ALLOYS; ELECTRONIC-PROPERTIES; SI/GE SUPERLATTICES; PHASE-DIAGRAMS; LAYER SUPERLATTICES; ORDER; TRANSITIONS; SYSTEMS AB First-principles total-energy pseudopotential calculations are carried out for Si, Ge, zinc-blende-structure SiGe, (Si2)p/(Ge2)p superlattices in various layer orientations G and with various choices of substrate lattice parameter alpha-s and for the Si0.5Ge0.5 random alloy. A subset of the results is used to construct an energy model, incorporating both strain (via an anharmonic valence force- field) and chemical interactions (via a rapidly convergent cluster expansion) that closely reproduces the first-principles results, including those not used as input to the model. The model is applied to the study of larger superlattices than are amenable to first-principles treatment, revealing trends in (i) constituent strain energies, (ii) interfacial "strain-relief" relaxation energies, and (iii) interfacial chemical energies. The analysis reveals the major regularities in the dependence of superlattice stability on {p,G,alpha-s}, and permits investigation of the nature of interactions at interfaces, including the substrate-film interface. C1 SOLAR ENERGY RES INST, GOLDEN, CO 80401 USA. RI Zunger, Alex/A-6733-2013 NR 55 TC 54 Z9 54 U1 3 U2 18 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 JUL 15 PY 1991 VL 44 IS 4 BP 1663 EP 1681 DI 10.1103/PhysRevB.44.1663 PG 19 WC Physics, Condensed Matter SC Physics GA FY718 UT WOS:A1991FY71800024 ER PT J AU NIELSEN, B LYNN, KG LEUNG, TC CORDTS, BF SERAPHIN, S AF NIELSEN, B LYNN, KG LEUNG, TC CORDTS, BF SERAPHIN, S TI DEFECTS IN OXYGEN-IMPLANTED SILICON-ON-INSULATOR STRUCTURES PROBED WITH POSITRONS SO PHYSICAL REVIEW B LA English DT Article ID MONOENERGETIC POSITRONS; INTERFACE; BEAM; SI AB Defects in a silicon-on-insulator structure formed by high-energy (200-keV) oxygen implantation has been studied utilizing a variable-energy positron beam. The positron-based probe is found to be especially sensitive to the condition of the top Si layer. Open-volume defects (cavities) are detected in the top 80-nm Si layer in the as-irradiated state. The majority of these defects are removed by high-temperature annealing (approximately 1300-degrees-C) after which the positron response correlates with the density of dislocations observed by transmission electron microscopy. Variations in dislocation density across a wafer were probed with positrons, demonstrating the potential of positrons in defect topology. C1 IBIS TECHNOL CORP,DANVERS,MA 01915. UNIV ARIZONA,TUCSON,AZ 85721. RP NIELSEN, B (reprint author), BROOKHAVEN NATL LAB,UPTON,NY 11973, USA. RI Nielsen, Bent/B-7353-2009 OI Nielsen, Bent/0000-0001-7016-0040 NR 20 TC 20 Z9 20 U1 0 U2 0 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 1098-0121 J9 PHYS REV B JI Phys. Rev. B PD JUL 15 PY 1991 VL 44 IS 4 BP 1812 EP 1816 DI 10.1103/PhysRevB.44.1812 PG 5 WC Physics, Condensed Matter SC Physics GA FY718 UT WOS:A1991FY71800042 ER PT J AU KLITSNER, T BECKER, RS VICKERS, JS AF KLITSNER, T BECKER, RS VICKERS, JS TI INITIAL-STAGES OF OXIDATION OF GE(111)-C(2X8) STUDIED BY SCANNING TUNNELING MICROSCOPY SO PHYSICAL REVIEW B LA English DT Article ID SEMICONDUCTOR SURFACES; OXYGEN-ADSORPTION; SI(111); SPECTROSCOPY; SILICON; STATES; ADATOMS AB The reaction of oxygen with the Ge(111)-c(2 X 8) surface has been studied with use of a scanning tunneling microscope. Atomically resolved images of the same area before and after oxygen exposure reveal that, on a room-temperature surface, the primary nucleation sites are the boundaries between domains of different orientations of the c(2 X 8) reconstruction. Point defects and disordered adatom regions can also act as nucleation sites. The c(2 X 8) reconstructed terraces themselves and, unexpectedly, the step risers between terraces are found to be relatively unreactive. At elevated sample temperatures, the surface unreconstructs due to adatom mobility. At these elevated temperatures, the oxide nucleates homogeneously and pins the surface in a disordered adatom configuration. This suggests that facilitated oxidation at elevated sample temperatures is primarily due to degradation of the c(2 X 8) reconstruction. Spectroscopic data from I-V curves are also presented and compared with known electronic spectra. C1 AT&T BELL LABS,MURRAY HILL,NJ 07974. RP KLITSNER, T (reprint author), SANDIA NATL LABS,ALBUQUERQUE,NM 87185, USA. NR 30 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 1098-0121 J9 PHYS REV B JI Phys. Rev. B PD JUL 15 PY 1991 VL 44 IS 4 BP 1817 EP 1824 DI 10.1103/PhysRevB.44.1817 PG 8 WC Physics, Condensed Matter SC Physics GA FY718 UT WOS:A1991FY71800043 ER PT J AU HWANG, RQ ZEGLINSKI, DM VAZQUEZDEPARGA, AL OGLETREE, DF SOMORJAI, GA SALMERON, M DENLEY, DR AF HWANG, RQ ZEGLINSKI, DM VAZQUEZDEPARGA, AL OGLETREE, DF SOMORJAI, GA SALMERON, M DENLEY, DR TI FORMATION OF SULFUR CLUSTERS ON RE(0001) SURFACES OBSERVED WITH THE SCANNING TUNNELING MICROSCOPE SO PHYSICAL REVIEW B LA English DT Note ID ADSORPTION AB We have studied the various structures formed by sulfur on Re(0001) single-crystal surfaces using a scanning tunneling microscope. At coverages of 0.25 monolayer and below, open lattices formed by single adatoms are formed, mostly with a (2 X 2) structure. Between 0.25 and 0.5 monolayer, phases consisting of three-, four-, or six-adatom clusters are observed. The sulfur trimers are formed first randomly in the (2 X 2) regions and then ordered as their coverage increases to saturation at 0.45 monolayer. In all cases sulfur atoms are adsorbed in threefold hollow sites. The formation of sulfur clusters above 0.25 monolayer is interpreted as evidence of substrate-mediated many-body forces. C1 SHELL DEV CO,HOUSTON,TX 77001. RP HWANG, RQ (reprint author), UNIV CALIF BERKELEY LAWRENCE BERKELEY LAB,DIV MAT SCI,1 CYCLOTRON RD,BERKELEY,CA 94720, USA. RI Vazquez de Parga, Amadeo/L-2418-2013; Ogletree, D Frank/D-9833-2016 OI Vazquez de Parga, Amadeo/0000-0003-0551-1603; Ogletree, D Frank/0000-0002-8159-0182 NR 13 TC 45 Z9 45 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 JUL 15 PY 1991 VL 44 IS 4 BP 1914 EP 1917 DI 10.1103/PhysRevB.44.1914 PG 4 WC Physics, Condensed Matter SC Physics GA FY718 UT WOS:A1991FY71800056 ER PT J AU BURDEN, CJ ROBERTS, CD AF BURDEN, CJ ROBERTS, CD TI LIGHT-CONE REGULAR VERTEX IN 3-DIMENSIONAL QUENCHED QED SO PHYSICAL REVIEW D LA English DT Article ID CHIRAL-SYMMETRY-BREAKING; SCHWINGER-DYSON EQUATION; QUANTUM CHROMODYNAMICS; COLLISION SYSTEMS; COUPLING-CONSTANT; TH COLLISIONS; QUARK MASSES; U-U; POSITRON; ELECTRODYNAMICS AB We study a model Schwinger-Dyson equation in three dimensions based on three-dimensional QED in the confining quenched approximation. We employ an ansatz for the dressed photon-fermion vertex function that does not have a singularity on the light cone. Our ansatz also allows us to study the relationship between the transverse part of the vertex and gauge independence of . We find that the transverse part of the vertex is crucial to obtaining independent of the gauge parameter. It modifies both the infrared and ultraviolet behavior of the fermion propagator without upsetting the 1/p2 behavior expected of the mass function at large spacelike p2. C1 ARGONNE NATL LAB, DIV PHYS, ARGONNE, IL 60439 USA. RP BURDEN, CJ (reprint author), AUSTRALIAN NATL UNIV, RES SCH PHYS SCI, DEPT THEORET PHYS, CANBERRA, ACT 2601, AUSTRALIA. RI Burden, Conrad/D-5556-2016; OI Burden, Conrad/0000-0003-0015-319X; Roberts, Craig/0000-0002-2937-1361 NR 45 TC 67 Z9 67 U1 0 U2 2 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 JUL 15 PY 1991 VL 44 IS 2 BP 540 EP 550 DI 10.1103/PhysRevD.44.540 PG 11 WC Astronomy & Astrophysics; Physics, Particles & Fields SC Astronomy & Astrophysics; Physics GA FX272 UT WOS:A1991FX27200026 ER PT J AU JOHNSON, MB BOWMAN, JD YOO, SH AF JOHNSON, MB BOWMAN, JD YOO, SH TI THEORY OF PARITY NONCONSERVATION IN COMPOUND-NUCLEAR STATES SO PHYSICAL REVIEW LETTERS LA English DT Article ID NEUTRON RESONANCES; VIOLATION; LA-139 AB We show how to calculate the root-mean-square parity-violating matrix element M for a heavy nucleus of valence nucleon number A-upsilon in terms of a standard parity-violating interaction V(PV). For large values of A-upsilon, we find a scaling law for M in terms of A-upsilon and the number of core nucleons. We compare our results to a recent measurement of M in U-239, obtaining results that bracket the data for three previously determined parameter sets of V(PV). RP JOHNSON, MB (reprint author), UNIV CALIF LOS ALAMOS SCI LAB,LOS ALAMOS,NM 87545, USA. NR 17 TC 33 Z9 33 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 JUL 15 PY 1991 VL 67 IS 3 BP 310 EP 313 DI 10.1103/PhysRevLett.67.310 PG 4 WC Physics, Multidisciplinary SC Physics GA FW159 UT WOS:A1991FW15900007 ER PT J AU BROOKES, NB CHANG, Y JOHNSON, PD AF BROOKES, NB CHANG, Y JOHNSON, PD TI MAGNETIC INTERFACE STATES AND FINITE-SIZE EFFECTS SO PHYSICAL REVIEW LETTERS LA English DT Article ID PHOTOEMISSION; SURFACE; ENERGY; FILMS; AG; SUPERLATTICES; FE(001); METALS; LAYERS; FIELD AB Studies of the formation of a nonmagnetic/magnetic silver/iron interface by spin-polarized photoemission identify magnetic interface states showing discrete binding energies dependent on the number of atomic layers in the overlayer. The results for one layer of silver on iron are in good agreement with a full-potential linearized-augmented-plane-wave calculation and tight-binding modeling allows us to reproduce qualitatively the layer-dependent binding energies for one, two, and three layers of silver on iron. The interface states appear to be related to a minority surface resonance on the iron surface. RP BROOKES, NB (reprint author), BROOKHAVEN NATL LAB,DEPT PHYS,UPTON,NY 11973, USA. NR 33 TC 92 Z9 92 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 JUL 15 PY 1991 VL 67 IS 3 BP 354 EP 357 DI 10.1103/PhysRevLett.67.354 PG 4 WC Physics, Multidisciplinary SC Physics GA FW159 UT WOS:A1991FW15900018 ER PT J AU HAGHIGHI, H KAISER, JH RAYNER, S WEST, RN LIU, JZ SHELTON, R HOWELL, RH SOLAL, F FLUSS, MJ AF HAGHIGHI, H KAISER, JH RAYNER, S WEST, RN LIU, JZ SHELTON, R HOWELL, RH SOLAL, F FLUSS, MJ TI DIRECT OBSERVATION OF FERMI-SURFACE IN YBA2CU3O7-DELTA SO PHYSICAL REVIEW LETTERS LA English DT Article ID ELECTRONIC-STRUCTURE; POSITRON; SUPERCONDUCTIVITY; DENSITY AB We have performed a high-precision measurement (5 x 10(8) coincidence counts) of the basal-plane electron-positron momentum density in well oxygenated, twin-free, single crystals of YBa2CU3O7-delta. The raw, processed, and k-space reduced spectra unambiguously show a clear image of a major Fermi surface sheet. The form and profile of that image are in substantial quantitative agreement with theoretical predictions of a GAMMA-X electron ridge section associated with states in the Cu-O chains. C1 UNIV CALIF DAVIS,DAVIS,CA 95616. UNIV CALIF LAWRENCE LIVERMORE NATL LAB,LIVERMORE,CA 94550. RP HAGHIGHI, H (reprint author), UNIV TEXAS,ARLINGTON,TX 76019, USA. NR 19 TC 100 Z9 100 U1 0 U2 3 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 0031-9007 J9 PHYS REV LETT JI Phys. Rev. Lett. PD JUL 15 PY 1991 VL 67 IS 3 BP 382 EP 385 DI 10.1103/PhysRevLett.67.382 PG 4 WC Physics, Multidisciplinary SC Physics GA FW159 UT WOS:A1991FW15900025 ER PT J AU COFFEY, MW CLEM, JR AF COFFEY, MW CLEM, JR TI UNIFIED THEORY OF EFFECTS OF VORTEX PINNING AND FLUX CREEP UPON THE RF SURFACE IMPEDANCE OF TYPE-II SUPERCONDUCTORS SO PHYSICAL REVIEW LETTERS LA English DT Article ID HIGH-TEMPERATURE SUPERCONDUCTORS; YBA2CU3O7-X; DEPENDENCE; CRYSTALS; FORCES; FIELD; FILMS; FLOW AB We present a new theoretical approach that permits the rf surface impedance Z(s) of type-11 superconductors to be calculated over a wide range of angular frequencies-omega, magnetic inductions B, and temperatures T. Our approach, based on a self-consistent treatment of vortex dynamics, includes the influence of both vortex pinning and flux creep upon Z(s) in a unified manner, by making use of continued-fraction-expansion results for the dynamic mobility of a particle undergoing Brownian motion in a periodic potential. C1 IOWA STATE UNIV SCI & TECHNOL,DEPT PHYS & ASTRON,AMES,IA 50011. RP COFFEY, MW (reprint author), IOWA STATE UNIV SCI & TECHNOL,US DOE,AMES LAB,AMES,IA 50011, USA. NR 33 TC 453 Z9 454 U1 3 U2 20 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 0031-9007 J9 PHYS REV LETT JI Phys. Rev. Lett. PD JUL 15 PY 1991 VL 67 IS 3 BP 386 EP 389 DI 10.1103/PhysRevLett.67.386 PG 4 WC Physics, Multidisciplinary SC Physics GA FW159 UT WOS:A1991FW15900026 ER PT J AU KWOK, WK WELP, U VINOKUR, VM FLESHLER, S DOWNEY, J CRABTREE, GW AF KWOK, WK WELP, U VINOKUR, VM FLESHLER, S DOWNEY, J CRABTREE, GW TI DIRECT OBSERVATION OF INTRINSIC PINNING BY LAYERED STRUCTURE IN SINGLE-CRYSTAL YBA2CU3O7-DELTA SO PHYSICAL REVIEW LETTERS LA English DT Article ID UPPER CRITICAL-FIELD; UNIAXIAL SUPERCONDUCTORS; TRANSITION AB The intrinsic pinning in twinned and untwinned single-crystal YBa2Cu3O7-delta is observed using a novel crossed-magnetic-field technique for obtaining angular resolutions of DELTA-theta < 0.005-degrees. The pinning occurs for magnetic-field directions within a critical angle-theta* < 1-degrees of the Cu-O planes. The data are discussed in the context of a lock-in transition of vortices in the a-b plane of the crystal. C1 ARGONNE NATL LAB,DIV MAT SCI,ARGONNE,IL 60439. PURDUE UNIV,DEPT PHYS,W LAFAYETTE,IN 47907. CHERNOGOLOVKA SOLID STATES PHYS INST,CHERNOGOLOVKA,USSR. RP KWOK, WK (reprint author), ARGONNE NATL LAB,SCI & TECHNOL CTR SUPERCOND,ARGONNE,IL 60439, USA. NR 24 TC 137 Z9 137 U1 0 U2 9 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 0031-9007 J9 PHYS REV LETT JI Phys. Rev. Lett. PD JUL 15 PY 1991 VL 67 IS 3 BP 390 EP 393 DI 10.1103/PhysRevLett.67.390 PG 4 WC Physics, Multidisciplinary SC Physics GA FW159 UT WOS:A1991FW15900027 ER PT J AU BESMANN, TM ABDELLATIF, AI AF BESMANN, TM ABDELLATIF, AI TI MODIFICATION OF OPTICAL-PROPERTIES WITH CERAMIC COATINGS SO THIN SOLID FILMS LA English DT Article ID CHEMICAL VAPOR-DEPOSITION AB Coatings of ceramic materials that exhibited high thermal absorptance and emittance were chemically vapor deposited on graphite, carbon-carbon, and refractory and reactive metals. The coatings prepared were SiC and B4C. The coatings were characterized with regard to composition, morphology, and optical properties. C1 GE AEROSP,PHILADELPHIA,PA 19101. RP BESMANN, TM (reprint author), OAK RIDGE NATL LAB,POB 2008,MS 6063,OAK RIDGE,TN 37831, USA. NR 8 TC 1 Z9 1 U1 0 U2 0 PU ELSEVIER SCIENCE SA LAUSANNE PI LAUSANNE 1 PA PO BOX 564, 1001 LAUSANNE 1, SWITZERLAND SN 0040-6090 J9 THIN SOLID FILMS JI Thin Solid Films PD JUL 15 PY 1991 VL 202 IS 1 BP 51 EP 59 DI 10.1016/0040-6090(91)90540-E PG 9 WC Materials Science, Multidisciplinary; Materials Science, Coatings & Films; Physics, Applied; Physics, Condensed Matter SC Materials Science; Physics GA FX997 UT WOS:A1991FX99700010 ER PT J AU DYE, RC MUENCHAUSEN, RE NOGAR, NS AF DYE, RC MUENCHAUSEN, RE NOGAR, NS TI LASER ABLATION OF Y2O3 IN AN OXYGEN ATMOSPHERE SO CHEMICAL PHYSICS LETTERS LA English DT Article ID SUPERCONDUCTING THIN-FILMS; GROUP IIIB ATOMS; CHEMILUMINESCENT REACTIONS; DEPOSITION; BEAM; YBA2CU3O7-DELTA; EVAPORATION; DEPENDENCE; EMISSION; RATES AB A Y203 Pressed powder target was ablated by pulses from a XeCl excimer laser, operating at 308 nm, 150 mJ/pulse, almost-equal-to 15 ns/pulse and 20 Hz. Emission spectra from Y* and YO* were recorded as a function of ambient oxygen pressure in the range 10(-5)-4 x 10(-1) Torr, at a peak laser fluence of almost-equal-to 4 J/cm2. A kinetic model is developed to describe the results, and the application to production of laser-deposited high-temperature superconductor thin films is discussed. C1 UNIV CALIF LOS ALAMOS SCI LAB,CTR EXPLORATORY RES & DEV,LOS ALAMOS,NM 87545. RP DYE, RC (reprint author), UNIV CALIF LOS ALAMOS SCI LAB,DIV CHEM & LASER SCI,MS G738,LOS ALAMOS,NM 87545, USA. NR 26 TC 17 Z9 17 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 JUL 12 PY 1991 VL 181 IS 6 BP 531 EP 536 DI 10.1016/0009-2614(91)80308-K PG 6 WC Chemistry, Physical; Physics, Atomic, Molecular & Chemical SC Chemistry; Physics GA FX548 UT WOS:A1991FX54800009 ER PT J AU HAN, P BARTELS, DM AF HAN, P BARTELS, DM TI ON THE HYDRATED ELECTRON AS A STRUCTURE-BREAKING ION SO JOURNAL OF PHYSICAL CHEMISTRY LA English DT Letter ID MOLECULAR-DYNAMICS SIMULATION AB It was recently concluded that hydrated electrons must be enormously effective "structure-breaking" ions, based on a redetermination of the entropy of solvation. The basis for this interpretation was compromised by the use of classical statistical mechanics for the quantum particle. We present here a revised interpretation of the hydration entropy and a new calculation of the free energy of transfer from H-2O to D2O (DELTA-G(trnfr) = + 1.3 +/- 1.1 kJ/mol). Both thermodynamic quantities support the previous conclusion that electrons are effective structure-breaking ions. C1 ARGONNE NATL LAB,DIV CHEM,ARGONNE,IL 60439. NR 23 TC 19 Z9 19 U1 0 U2 2 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 SN 0022-3654 J9 J PHYS CHEM-US JI J. Phys. Chem. PD JUL 11 PY 1991 VL 95 IS 14 BP 5367 EP 5370 DI 10.1021/j100167a001 PG 4 WC Chemistry, Physical SC Chemistry GA FW477 UT WOS:A1991FW47700001 ER PT J AU UCHIDA, H CURTIS, CJ NOZIK, AJ AF UCHIDA, H CURTIS, CJ NOZIK, AJ TI GAAS NANOCRYSTALS PREPARED IN QUINOLINE SO JOURNAL OF PHYSICAL CHEMISTRY LA English DT Letter ID COLLOIDAL SEMICONDUCTOR PARTICLES; MATCHED SUPERLATTICE ELECTRODES; MULTIPLE QUANTUM-WELLS; SMALL CDS PARTICLES; SIZE QUANTIZATION; STRAINED-LAYER; PHOTOCURRENT SPECTROSCOPY; PICOSECOND RELAXATION; GALLIUM-ARSENIDE; CRYSTALLITES AB GaAs nanocrystals were prepared in quinoline according to procedures previously published in the literature. However, we find that the optical absorption and photoluminescence properties of GaAs colloids that we prepared in quinoline are dominated by molecular species that mask the optical properties of the GaAs nanocrystals. These species appear to be present both in solution and on the surface of the GaAs nanocrystals; they have not been identified but are believed to consist of quinoline oligomers and/or Ga-quinoline complexes. C1 SOLAR ENERGY RES INST,GOLDEN,CO 80401. OI Uchida, Hiroyuki/0000-0001-6718-5431 NR 60 TC 68 Z9 69 U1 0 U2 6 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 SN 0022-3654 J9 J PHYS CHEM-US JI J. Phys. Chem. PD JUL 11 PY 1991 VL 95 IS 14 BP 5382 EP 5384 DI 10.1021/j100167a006 PG 3 WC Chemistry, Physical SC Chemistry GA FW477 UT WOS:A1991FW47700006 ER PT J AU THOMPSON, MA ZERNER, MC FAJER, J AF THOMPSON, MA ZERNER, MC FAJER, J TI A THEORETICAL-EXAMINATION OF THE ELECTRONIC-STRUCTURE AND EXCITED-STATES OF THE BACTERIOCHLOROPHYLL B DIMER FROM RHODOPSEUDOMONAS-VIRIDIS SO JOURNAL OF PHYSICAL CHEMISTRY LA English DT Article ID PHOTOSYNTHETIC REACTION CENTER; BACTERIAL REACTION CENTERS; DETECTION-WAVELENGTH DEPENDENCE; DIFFERENTIAL-OVERLAP TECHNIQUE; RHODOBACTER-SPHAEROIDES; INTERMEDIATE NEGLECT; CHARGE SEPARATION; OPTICAL-SPECTRA; LOW-TEMPERATURE; PRIMARY DONOR AB We report calculations of the electronic structure of the bacteriochlorophyll b (BChlb) dimer (P) from the reaction center of the photosynthetic bacterium, Rhodopseudomonas viridis. The calculations use the Intermediate Neglect of Differential Overlap Spectroscopic Model (INDO/S). We classify the four low-lying excited states of Q(y) origin, which determine the photophysics and photochemistry of the dimer, as mainly excitonic or charge resonance, using the excited configurations of the monomers as a basis. The calculations yield an 1850-cm-1 red shift in the lowest lying Q(y) (Q(y1) state of P relative to the average of its constituent monomers. The Q(y1) state of P contains substantial charge resonance character with only a small net transfer of charge between its BChlb components. Charge resonance contributes to the red shift of the Q(y1) state about as much as the exciton splitting, while the surrounding protein contributes only a small effect to this red shift. This work suggests that the red shift of P is mostly due to the formation of the BChlb dimer. Consideration of the protein is found to influence the charge-transfer character in Q(y1), as well as in the higher energy Q(y3) and Q(y4) states of P, and gives better agreement with the experimental Stark results. The calculated linear dichroism and the splitting between the two low-lying excitonic bands of P in Rps. viridis compare well with experimental results and support the identification of the transition at 850 nm in the experimental spectrum as the upper Q(y) exciton component. Small conformational changes in P yield calculated optical changes as large as 800 cm-1. In addition, the blue shift in the lowest Q(y) band of the BChla dimer in Rb. sphaeroides (Q(y) = 870 nm) relative to the BChlb dimer of Rps. viridis (Q(y) = 960 nm) is easily rationalized by an increase in the average spacing between the macrocyles of 0.2-0.3 angstrom. C1 UNIV FLORIDA,QUANTUM THEORY PROJECT,GAINESVILLE,FL 32611. BROOKHAVEN NATL LAB,DEPT APPL SCI,UPTON,NY 11973. NR 84 TC 128 Z9 129 U1 0 U2 7 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 SN 0022-3654 J9 J PHYS CHEM-US JI J. Phys. Chem. PD JUL 11 PY 1991 VL 95 IS 14 BP 5693 EP 5700 DI 10.1021/j100167a058 PG 8 WC Chemistry, Physical SC Chemistry GA FW477 UT WOS:A1991FW47700058 ER PT J AU CLARKE, J AF CLARKE, J TI SUPERCONDUCTIVITY - SQUIDS IN WITH APPLICATIONS SO NATURE LA English DT Editorial Material C1 UNIV CALIF BERKELEY LAWRENCE BERKELEY LAB,BERKELEY,CA 94720. RP CLARKE, J (reprint author), UNIV CALIF BERKELEY,DEPT PHYS,BERKELEY,CA 94720, USA. NR 1 TC 0 Z9 0 U1 0 U2 0 PU MACMILLAN MAGAZINES LTD PI LONDON PA 4 LITTLE ESSEX STREET, LONDON, ENGLAND WC2R 3LF SN 0028-0836 J9 NATURE JI Nature PD JUL 11 PY 1991 VL 352 IS 6331 BP 110 EP 111 PG 2 WC Multidisciplinary Sciences SC Science & Technology - Other Topics GA FW097 UT WOS:A1991FW09700027 ER PT J AU CARLSON, CE LASSILA, KE SUKHATME, UP AF CARLSON, CE LASSILA, KE SUKHATME, UP TI BACKWARD HADRONS FROM DEEP INELASTIC LEPTON SCATTERING ON NUCLEI SO PHYSICS LETTERS B LA English DT Article ID QUARK DISTRIBUTIONS AB We consider the predictions of a quark cluster model for backward hadrons produced in deep inelastic scattering of leptons from nuclear targets. After making some kinematic comments, we show that the counting rules for the longitudinal momentum distribution supplemented by a standard parametrization of the transverse momentum distribution produce a decent representation of the available high energy experimental backward proton results. C1 IOWA STATE UNIV SCI & TECHNOL, DEPT PHYS, AMES, IA 50011 USA. IOWA STATE UNIV SCI & TECHNOL, US DOE, AMES LAB, AMES, IA 50011 USA. UNIV ILLINOIS, DEPT PHYS, CHICAGO, IL 60680 USA. RP CARLSON, CE (reprint author), COLL WILLIAM & MARY, DEPT PHYS, WILLIAMSBURG, VA 23185 USA. NR 15 TC 18 Z9 18 U1 0 U2 0 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0370-2693 EI 1873-2445 J9 PHYS LETT B JI Phys. Lett. B PD JUL 11 PY 1991 VL 263 IS 2 BP 277 EP 281 DI 10.1016/0370-2693(91)90600-U PG 5 WC Astronomy & Astrophysics; Physics, Nuclear; Physics, Particles & Fields SC Astronomy & Astrophysics; Physics GA FX712 UT WOS:A1991FX71200025 ER PT J AU DECAMP, D DESCHIZEAUX, B GOY, C LEES, JP MINARD, MN ALEMANY, R CRESPO, JM DELFINO, M FERNANDEZ, E GAITAN, V GARRIDO, L MIR, LM PACHECO, A CATANESI, MG CREANZA, D DE PALMA, M FARILLA, A IASELLI, G MAGGI, G MAGGI, M NATALI, S NUZZO, S QUATTROMINI, M RANIERI, A RASO, G ROMANO, F RUGGIERI, F SELVAGGI, G SILVESTRIS, L TEMPESTA, P ZITO, G GAO, Y HU, H HUANG, D HUANG, X LIN, J LOU, J QIAO, C RUAN, T WANG, T XIE, Y XU, D XU, R ZHANG, J ZHAO, W ATWOOD, WB BAUERDICK, LAT BIRD, F BLUCHER, E BONVICINI, G BOSSI, F BROWN, D BURNETT, TH DREVERMANN, H FORTY, RW GRAB, C HAGELBERG, R HAYWOOD, S HILGART, J JOST, B KASEMANN, M KNOBLOCH, J LACOURT, A LANCON, E LEHRAUS, I LOHSE, T MARCHIORO, A MARTINEZ, M MATO, P MENARY, S MINTEN, A MIOTTO, A MIQUEL, R MOSER, HG NASH, J PALAZZI, P RANJARD, F REDLINGER, G ROTH, A ROTHBERG, J ROTSCHEIDT, H ST DENIS, R SCHLATTER, D TAKASHIMA, M TALBY, M TEJESSY, W WACHSMUTH, H WASSERBAECH, S WHEELER, S WIEDENMANN, W WITZELING, W WOTSCHACK, J WU, W AJALTOUNI, Z BARADADIN-OTWINOWSKA, M FALVARD, A EL FELLOUS, R GAY, P HENRARD, P JOUSSET, J MICHEL, B MONTRET, JC PALLIN, D PERRET, P PRORIOL, J PRULHIERE, F STIMPFL, G HANSEN, JD HANSEN, JR HANSEN, PH MOLLERUD, R NIELSEN, ER NILSSON, BS EFTHYMIOPOULOS, I SIMOPOULOU, E VAYAKI, A BADIER, J BLONDEL, A BONNEAUD, G BOUROTTE, J BRAEMS, F BRIENT, JC FOUQUE, G GAMESS, A GUIRLET, R ORTEU, S ROSOWSKY, A ROUGE, A RUMPF, M TANAKA, R VIDEAU, H CANDLIN, DJ VEITCH, E PARRINI, G CORDEN, M GEORGIOPOULOS, C IKEDA, M LANNUTTI, J LEVINTHAL, D MERMIKIDES, M SAWYER, L ANTONELLI, A BALDINI, R BENCIVENNI, G BOLOGNA, G CAMPANA, P CAPON, G CERUTTI, F CHIARELLA, V D'ETTORRE-PIAZZOLI, B FELICI, G LAURELLI, P MANNOCCHI, G MURTAS, F MURTAS, GP NICOLETTI, G PASSALACQUA, L PEPE-ALTARELLI, M PICCHI, P ZOGRAFOU, P ALTOON, B BOYLE, O HALLEY, AW TEN HAVE, I HEARNS, JL LYNCH, JG MORTON, WT RAINE, C SCARR, JM SMITH, K THOMPSON, AS TURNBULL, RM BRANDL, B BRAUN, O GEIGES, R GEWENIGER, C HANKE, P HEPP, V KLUGE, EE MAUMARY, Y PUTZER, A RENSCH, B STAHL, A TITTEL, K WUNSCH, M BELK, AT BEUSELINCK, R BINNIE, DM CAMERON, W CATTANEO, M DORNAN, PJ DUGEAY, S GREENE, AM HASSARD, JF LIESKE, NM PATTON, SJ PAYNE, DG PHILLIPS, MJ SEDGBEER, JK TAYLOR, G TOMALIN, IR WRIGHT, AG GIRTLER, P KUHN, D RUDOLPH, G BOWDERY, CK BRODBECK, TJ FINCH, AJ FOSTER, F HUGHES, G KEEMER, NR NUTTALL, M PATEL, A ROWLINGSON, BS SLOAN, T SNOW, SW WHELAN, EP BARCZEWSKI, T KLEINKNECHT, K RAAH, J RENK, B ROEHN, S SANDER, HG SCHMELLING, M SCHMIDT, H STEEG, F WALTHER, SM WOLF, B ALBANESE, JP AUBERT, JJ BENCHOUK, C BERNARD, V BONISSENT, A COURVOISIER, D ETIENNE, F PAPALEXIOU, S PAYRE, P PIETRZYK, B QIAN, Z BECKER, H BLUM, W CATTANEO, P COWAN, G DEHNING, B DIETL, H DYDAK, F FERNANDEZ-BOSMAN, M HANSL-KOZANECKA, T JAHN, A KOZANECKI, W LANGE, E LAUBER, J LUTJENS, G LUTZ, G MANNER, W PAN, Y RICHTER, R SCHRODER, J SCHWARZ, AS SETTLES, R STIERLIN, U THOMAS, J WOLF, G BERTIN, V BOUCROT, J CALLOT, O CHEN, X CORDIER, A DAVIER, M GANIS, G GRIVAZ, JF HARVEY, J HEUSSE, P JANOT, P KIM, DW LE DIBERDER, F LEFRANCOIS, J LUTZ, AM VEILLET, JJ VIDEAU, I ZHANG, Z ZOMER, F ABBANEO, D AMENDOLIA, SR BAGLIESI, G BATIGNANI, G BOSISIO, L BOTTIGLI, U BRADASCHIA, C CARPINELLI, M CIOCCI, MA DELL'ORSO, R FERRANTE, I FIDECARO, F FOA, L FOCARDI, E FORTI, F GIASSI, A GIORGI, MA LIGABUE, F LUSIANI, A MANNELLI, EB MARROCCHESI, PS MESSINEO, A MONETA, L PALLA, F SANGUINETTI, G STEINBERGER, J TENCHINI, R TONELLI, G TRIGGIANI, G VANNINI, C VENTURI, A VERDINI, PG WALSH, J CARTER, JM GREEN, MG MARCH, PV MEDCALF, T QUAZI, IS SAICH, MR STRONG, JA THOMAS, RM WEST, LR WILDISH, T BOTTERILL, DR CLIFFT, RW EDGECOCK, TR EDWARDS, M FISHER, SM JONES, TJ NORTON, PR SALMON, DP THOMPSON, JC BLOCH-DEVAUX, B COLAS, P KLOPFENSTEIN, C LOCCI, E LOUCATOS, S MONNIER, E PEREZ, P PERLAS, JA PERRIER, F RANDER, J RENARDY, JF ROUSSARIE, A SCHULLER, JP SCHWINDLING, J VALLAGE, B ASHMAN, JG BOOTH, CN BUTTAR, C CARNEY, R CARTWRIGHT, S COMBLEY, F DINSDALE, M DOGRU, M HATFIELD, F MARTIN, J PARKER, D REEVES, P THOMPSON, LF BRANDT, S BURKHARDT, H GRUPEN, C MEINHARD, H MIRABITO, L NEUGEBAUER, E SCHAFER, U SEYWERD, H APOLLINARI, G GIANNINI, G GOBBO, B LIELLO, F RAGUSA, F ROLANDI, L STIEGLER, U BELLANTONI, L BOUDREAU, JF CINABRO, D CHEN, X CONWAY, JS COWEN, DF FENG, Z FERGUSON, DPS GAO, YS GRAHL, J HARTON, JL JACOBSEN, JE JARED, RC JOHNSON, RP LECLAIRE, BW PAN, YB PATER, JR SAADI, Y SHARMA, V SHI, ZH TANG, YH WALSH, AM WEAR, JA WEBER, FV WHITNEY, MH WU, SL ZOBERNIG, G AF DECAMP, D DESCHIZEAUX, B GOY, C LEES, JP MINARD, MN ALEMANY, R CRESPO, JM DELFINO, M FERNANDEZ, E GAITAN, V GARRIDO, L MIR, LM PACHECO, A CATANESI, MG CREANZA, D DE PALMA, M FARILLA, A IASELLI, G MAGGI, G MAGGI, M NATALI, S NUZZO, S QUATTROMINI, M RANIERI, A RASO, G ROMANO, F RUGGIERI, F SELVAGGI, G SILVESTRIS, L TEMPESTA, P ZITO, G GAO, Y HU, H HUANG, D HUANG, X LIN, J LOU, J QIAO, C RUAN, T WANG, T XIE, Y XU, D XU, R ZHANG, J ZHAO, W ATWOOD, WB BAUERDICK, LAT BIRD, F BLUCHER, E BONVICINI, G BOSSI, F BROWN, D BURNETT, TH DREVERMANN, H FORTY, RW GRAB, C HAGELBERG, R HAYWOOD, S HILGART, J JOST, B KASEMANN, M KNOBLOCH, J LACOURT, A LANCON, E LEHRAUS, I LOHSE, T MARCHIORO, A MARTINEZ, M MATO, P MENARY, S MINTEN, A MIOTTO, A MIQUEL, R MOSER, HG NASH, J PALAZZI, P RANJARD, F REDLINGER, G ROTH, A ROTHBERG, J ROTSCHEIDT, H ST DENIS, R SCHLATTER, D TAKASHIMA, M TALBY, M TEJESSY, W WACHSMUTH, H WASSERBAECH, S WHEELER, S WIEDENMANN, W WITZELING, W WOTSCHACK, J WU, W AJALTOUNI, Z BARADADIN-OTWINOWSKA, M FALVARD, A EL FELLOUS, R GAY, P HENRARD, P JOUSSET, J MICHEL, B MONTRET, JC PALLIN, D PERRET, P PRORIOL, J PRULHIERE, F STIMPFL, G HANSEN, JD HANSEN, JR HANSEN, PH MOLLERUD, R NIELSEN, ER NILSSON, BS EFTHYMIOPOULOS, I SIMOPOULOU, E VAYAKI, A BADIER, J BLONDEL, A BONNEAUD, G BOUROTTE, J BRAEMS, F BRIENT, JC FOUQUE, G GAMESS, A GUIRLET, R ORTEU, S ROSOWSKY, A ROUGE, A RUMPF, M TANAKA, R VIDEAU, H CANDLIN, DJ VEITCH, E PARRINI, G CORDEN, M GEORGIOPOULOS, C IKEDA, M LANNUTTI, J LEVINTHAL, D MERMIKIDES, M SAWYER, L ANTONELLI, A BALDINI, R BENCIVENNI, G BOLOGNA, G CAMPANA, P CAPON, G CERUTTI, F CHIARELLA, V D'ETTORRE-PIAZZOLI, B FELICI, G LAURELLI, P MANNOCCHI, G MURTAS, F MURTAS, GP NICOLETTI, G PASSALACQUA, L PEPE-ALTARELLI, M PICCHI, P ZOGRAFOU, P ALTOON, B BOYLE, O HALLEY, AW TEN HAVE, I HEARNS, JL LYNCH, JG MORTON, WT RAINE, C SCARR, JM SMITH, K THOMPSON, AS TURNBULL, RM BRANDL, B BRAUN, O GEIGES, R GEWENIGER, C HANKE, P HEPP, V KLUGE, EE MAUMARY, Y PUTZER, A RENSCH, B STAHL, A TITTEL, K WUNSCH, M BELK, AT BEUSELINCK, R BINNIE, DM CAMERON, W CATTANEO, M DORNAN, PJ DUGEAY, S GREENE, AM HASSARD, JF LIESKE, NM PATTON, SJ PAYNE, DG PHILLIPS, MJ SEDGBEER, JK TAYLOR, G TOMALIN, IR WRIGHT, AG GIRTLER, P KUHN, D RUDOLPH, G BOWDERY, CK BRODBECK, TJ FINCH, AJ FOSTER, F HUGHES, G KEEMER, NR NUTTALL, M PATEL, A ROWLINGSON, BS SLOAN, T SNOW, SW WHELAN, EP BARCZEWSKI, T KLEINKNECHT, K RAAH, J RENK, B ROEHN, S SANDER, HG SCHMELLING, M SCHMIDT, H STEEG, F WALTHER, SM WOLF, B ALBANESE, JP AUBERT, JJ BENCHOUK, C BERNARD, V BONISSENT, A COURVOISIER, D ETIENNE, F PAPALEXIOU, S PAYRE, P PIETRZYK, B QIAN, Z BECKER, H BLUM, W CATTANEO, P COWAN, G DEHNING, B DIETL, H DYDAK, F FERNANDEZ-BOSMAN, M HANSL-KOZANECKA, T JAHN, A KOZANECKI, W LANGE, E LAUBER, J LUTJENS, G LUTZ, G MANNER, W PAN, Y RICHTER, R SCHRODER, J SCHWARZ, AS SETTLES, R STIERLIN, U THOMAS, J WOLF, G BERTIN, V BOUCROT, J CALLOT, O CHEN, X CORDIER, A DAVIER, M GANIS, G GRIVAZ, JF HARVEY, J HEUSSE, P JANOT, P KIM, DW LE DIBERDER, F LEFRANCOIS, J LUTZ, AM VEILLET, JJ VIDEAU, I ZHANG, Z ZOMER, F ABBANEO, D AMENDOLIA, SR BAGLIESI, G BATIGNANI, G BOSISIO, L BOTTIGLI, U BRADASCHIA, C CARPINELLI, M CIOCCI, MA DELL'ORSO, R FERRANTE, I FIDECARO, F FOA, L FOCARDI, E FORTI, F GIASSI, A GIORGI, MA LIGABUE, F LUSIANI, A MANNELLI, EB MARROCCHESI, PS MESSINEO, A MONETA, L PALLA, F SANGUINETTI, G STEINBERGER, J TENCHINI, R TONELLI, G TRIGGIANI, G VANNINI, C VENTURI, A VERDINI, PG WALSH, J CARTER, JM GREEN, MG MARCH, PV MEDCALF, T QUAZI, IS SAICH, MR STRONG, JA THOMAS, RM WEST, LR WILDISH, T BOTTERILL, DR CLIFFT, RW EDGECOCK, TR EDWARDS, M FISHER, SM JONES, TJ NORTON, PR SALMON, DP THOMPSON, JC BLOCH-DEVAUX, B COLAS, P KLOPFENSTEIN, C LOCCI, E LOUCATOS, S MONNIER, E PEREZ, P PERLAS, JA PERRIER, F RANDER, J RENARDY, JF ROUSSARIE, A SCHULLER, JP SCHWINDLING, J VALLAGE, B ASHMAN, JG BOOTH, CN BUTTAR, C CARNEY, R CARTWRIGHT, S COMBLEY, F DINSDALE, M DOGRU, M HATFIELD, F MARTIN, J PARKER, D REEVES, P THOMPSON, LF BRANDT, S BURKHARDT, H GRUPEN, C MEINHARD, H MIRABITO, L NEUGEBAUER, E SCHAFER, U SEYWERD, H APOLLINARI, G GIANNINI, G GOBBO, B LIELLO, F RAGUSA, F ROLANDI, L STIEGLER, U BELLANTONI, L BOUDREAU, JF CINABRO, D CHEN, X CONWAY, JS COWEN, DF FENG, Z FERGUSON, DPS GAO, YS GRAHL, J HARTON, JL JACOBSEN, JE JARED, RC JOHNSON, RP LECLAIRE, BW PAN, YB PATER, JR SAADI, Y SHARMA, V SHI, ZH TANG, YH WALSH, AM WEAR, JA WEBER, FV WHITNEY, MH WU, SL ZOBERNIG, G CA ALEPH Collaboration TI MEASUREMENT OF THE FORWARD BACKWARD ASYMMETRY IN Z-]BBAR AND Z-]CCBAR SO PHYSICS LETTERS B LA English DT Article ID Z-DECAYS; E+E ANNIHILATION; ENERGIES; LEP AB From a sample of 150 000 hadronic Z decays collected with the ALEPH detector at LEP, events containing prompt leptons are used to measure the forward-backward asymmetries for the channels Z --> bbBAR and Z --> ccBAR, giving the results A(FB)b = 0.126 +/- 0.028 +/- 0.012 and A(FB)c = 0.064 +/- 0.039 +/- 0.030. These asymmetries correspond to the value of effective electroweak mixing angle at the Z mass sin2-theta-w (m(Z)2) = 0.2262 +/- 0.0053. C1 CNRS, IN2P3, LAB PHYS PARTICULES, F-74019 ANNECY LE VIEUX, FRANCE. UNIV AUTONOMA BARCELONA, LAB FIS ALTAS ENERGIAS, E-08193 BARCELONA, SPAIN. IST NAZL FIS NUCL, SEZ BARI, I-70126 BARI, ITALY. IST NAZL FIS NUCL, DIPARTIMENTO FIS UNIV, I-70126 BARI, ITALY. ACAD SINICA, INST HIGH ENERGY PHYS, BEIJING, PEOPLES R CHINA. CERN, EUROPEAN LAB PARTICLE PHYS, CH-1211 GENEVA 23, SWITZERLAND. UNIV BLAISE PASCAL, CNRS, IN2P3, LAB PHYS CORPUSCULAIRE, F-63177 AUBIERE, FRANCE. NIELS BOHR INST, DK-2100 COPENHAGEN, DENMARK. NUCL RES CTR DEMOKRITOS NRCD, ATHENS, GREECE. ECOLE POLYTECH, CNRS, IN2P3, LAB PHYS NUCL & HAUTES ENERGIES, F-91128 PALAISEAU, FRANCE. UNIV EDINBURGH, DEPT PHYS, EDINBURGH EH9 3JZ, ENGLAND. UNIV FIRENZE, DIPARTIMENTO FIS, I-50125 FLORENCE, ITALY. IST NAZL FIS NUCL, SEZ FIRENZE, I-50125 FLORENCE, ITALY. FLORIDA STATE UNIV, SUPERCOMP COMPUTAT RES INST, TALLAHASSEE, FL 32306 USA. FLORIDA STATE UNIV, DEPT PHYS, TALLAHASSEE, FL 32306 USA. IST NAZL FIS NUCL, LNF, I-00044 FRASCATI, ITALY. UNIV GLASGOW, DEPT PHYS & ASTRON, GLASGOW G12 8QQ, LANARK, SCOTLAND. UNIV HEIDELBERG, INST HOCHENERGIEPHYS, W-6900 HEIDELBERG, GERMANY. IMPERIAL COLL, DEPT PHYS, LONDON SW7 2BZ, ENGLAND. UNIV INNSBRUCK, INST EXPT PHYS, A-6020 INNSBRUCK, AUSTRIA. UNIV LANCASTER, DEPT PHYS, LANCASTER LA1 4YB, ENGLAND. UNIV MAINZ, INST PHYS, W-6500 MAINZ, GERMANY. CNRS, IN2P3, FAC SCI LUMINY, CTR PHYS PARTICULES, F-13288 MARSEILLE, FRANCE. WERNER HEISENBERG INST PHYS, MAX PLANCK INST PHYS & ASTROPHYS, W-8000 MUNICH, GERMANY. UNIV PARIS SUD, CNRS, IN2P3, LAB ACCELERATEUR LINEAIRE, F-91405 ORSAY, FRANCE. UNIV PISA, DIPARTIMENTO FIS, INFN, SEZ PISA, I-56010 PISA, ITALY. SCUOLA NORMALE SUPER, I-56010 PISA, ITALY. UNIV LONDON, ROYAL HOLLOWAY & BEDFORD NEW COLL, DEPT PHYS, SURREY TW20 0EX, ENGLAND. RUTHERFORD APPLETON LAB, PARTICLE PHYS DEPT, DIDCOT OX11 0QX, OXON, ENGLAND. CEN SACLAY, DEPT PHYS PARTICULES ELEMENTAIRES, F-91191 GIF SUR YVETTE, FRANCE. UNIV SHEFFIELD, DEPT PHYS, SHEFFIELD S3 7RH, ENGLAND. UNIV SIEGEN, FACHBEREICH PHYS, W-5900 SIEGEN, GERMANY. UNIV TRIESTE, DIPARTIMENTO FIS, I-34127 TRIESTE, ITALY. IST NAZL FIS NUCL, SEZ TRIESTE, I-34127 TRIESTE, ITALY. UNIV WISCONSIN, DEPT PHYS, MADISON, WI 53706 USA. SLAC, Stanford, CA 94309 USA. UNIV WASHINGTON, Seattle, WA 98195 USA. LBL, Berkeley, CA 94720 USA. FAC SCI, CTR PHYS PARTICULES, F-13288 MARSEILLE, FRANCE. UNIV TORINO, IST FIS GEN, Turin, ITALY. CNR, IST COSMO GEOFIS, I-10126 Turin, ITALY. CERN, PPE DIV, CH-1211 Geneva 23, SWITZERLAND. RP DECAMP, D (reprint author), CNRS, IN2P3, LAB PHYS PARTICULES, F-74019 ANNECY LE VIEUX, FRANCE. RI Murtas, Fabrizio/B-5729-2012; Booth, Christopher/B-5263-2016; Delfino, Manuel/A-1545-2012; Pacheco Pages, Andres/C-5353-2011; Ferrante, Isidoro/F-1017-2012; Venturi, Andrea/J-1877-2012; Perrier, Frederic/A-5953-2011; Rolandi, Luigi (Gigi)/E-8563-2013; Colas, Paul/F-2876-2013; Bosman, Martine/J-9917-2014; Fernandez, Enrique/L-5387-2014; Mir, Lluisa-Maria/G-7212-2015; ciocci, maria agnese /I-2153-2015; Lusiani, Alberto/N-2976-2015; Marrocchesi, Pier Simone/N-9068-2015; Forti, Francesco/H-3035-2011; Lusiani, Alberto/A-3329-2016 OI Booth, Christopher/0000-0002-6051-2847; Delfino, Manuel/0000-0002-9468-4751; Pacheco Pages, Andres/0000-0001-8210-1734; Ferrante, Isidoro/0000-0002-0083-7228; Rolandi, Luigi (Gigi)/0000-0002-0635-274X; Bosman, Martine/0000-0002-7290-643X; Fernandez, Enrique/0000-0002-6405-9488; Mir, Lluisa-Maria/0000-0002-4276-715X; ciocci, maria agnese /0000-0003-0002-5462; Lusiani, Alberto/0000-0002-6876-3288; Marrocchesi, Pier Simone/0000-0003-1966-140X; Forti, Francesco/0000-0001-6535-7965; Lusiani, Alberto/0000-0002-6876-3288 NR 19 TC 35 Z9 35 U1 0 U2 4 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0370-2693 J9 PHYS LETT B JI Phys. Lett. B PD JUL 11 PY 1991 VL 263 IS 2 BP 325 EP 336 DI 10.1016/0370-2693(91)90607-R PG 12 WC Astronomy & Astrophysics; Physics, Nuclear; Physics, Particles & Fields SC Astronomy & Astrophysics; Physics GA FX712 UT WOS:A1991FX71200032 ER PT J AU HAWKINS, I CRAIG, N AF HAWKINS, I CRAIG, N TI PROBING SHOCK-MODELS OF CH+ FORMATION SO ASTROPHYSICAL JOURNAL LA English DT Article DE INTERSTELLAR, MOLECULES; LINE PROFILES; MOLECULAR PROCESSES; RADIAL VELOCITIES; SHOCK WAVES ID DIFFUSE INTERSTELLAR CLOUDS; INTER-STELLAR SHOCKS; ZETA-OPHIUCHI; MAGNETOHYDRODYNAMIC SHOCKS; MOLECULAR CH+; LINE; GAS; SPECTROSCOPY; PLEIADES; MATTER AB We have carried out high-resolution, high signal-to-noise ratio (S/N) CCD observations of interstellar CH+ (4232 angstrom) and CH (4300 angstrom) toward the bright stars zeta-Oph, zeta-Per, and P Cyg in an attempt to test shock models of CH+ formation. Theoretical models make observable predictions which, if verified, can help constrain the different proposed theories. The expected difference in heliocentric velocity between the CH and CH+ molecules, as well as the intrinsic line profile shapes, were probed by these observations. We do not find differences between the CH and CH+ heliocentric velocities of the magnitude predicted by the shock theories in any of the three stars. Toward zeta-Oph and zeta-Per, where we obtained very high quality data, we find no difference between the observed CH+ line profiles and a Gaussian function which one would expect as a consequence of shock structure. In the case of P Cyg, the analysis is complicated by the presence of two velocity components. We have resolved the CH+ lines toward zeta-Oph and zeta-Per, obtaining Gaussian line width parameters which are broad as predicted by shock models and which are consistent with previous measurements. Our observations yield only weak evidence in favor of the predictions put forth by shock models of molecule formation. C1 UNIV CALIF LAWRENCE LIVERMORE NATL LAB,INST GEOPHYS & PLANETARY PHYS,LIVERMORE,CA 94550. RP HAWKINS, I (reprint author), UNIV CALIF BERKELEY,CTR EUV ASTROPHYS,BERKELEY,CA 94720, USA. NR 40 TC 16 Z9 16 U1 0 U2 1 PU UNIV CHICAGO PRESS PI CHICAGO PA 5720 S WOODLAWN AVE, CHICAGO, IL 60637 SN 0004-637X J9 ASTROPHYS J JI Astrophys. J. PD JUL 10 PY 1991 VL 375 IS 2 BP 642 EP 651 DI 10.1086/170227 PN 1 PG 10 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA FV411 UT WOS:A1991FV41100025 ER PT J AU WOODS, DT HOLZER, TE AF WOODS, DT HOLZER, TE TI THE EFFECTS OF MASS-FLOW ON THE TEMPERATURE AND ABUNDANCE STRUCTURE OF THE SOLAR TRANSITION REGION SO ASTROPHYSICAL JOURNAL LA English DT Article DE SUN, ABUNDANCES; SUN, ATMOSPHERIC MOTIONS; SUN, TRANSITION REGION ID VELOCITY DISTRIBUTION-FUNCTIONS; QUIET-SUN; CHROMOSPHERE; CORONA; EQUILIBRIUM; GRADIENTS; LINES; ATMOSPHERE; IONIZATION; EQUATIONS AB We have computed the density and temperature structure of a multicomponent plasma consisting of electrons, protons, ionized helium, and a trace of minor ion species (carbon). The equations of force and energy balance for this model are developed allowing for the fact that species may have different temperatures. We have solved these equations using an electron temperature profile which is taken form inversion of the observationally deduced emission measure curve. For the case of downflows, we find that the minor ion temperature can be significantly hotter than the electron temperature, and significant abundance enhancements are possible due to the slow down of the minor species from the effect of the thermal force. We have also provided a simple physical picture of the origin of the thermal force, which is not so easily seen in the context of a standard diffusion treatment. The minor ion temperature enhancements relative to the electron temperature can have significant implications for the computation of detailed line profiles. In addition, the effect of the thermal force may be of importance to studies of the emission from asymmetrically heated loops in which the minor ion abundance will be enhanced in the downflowing leg and diminished in the upward flowing leg. This would tend to make the downflowing side brighter in a given line, and therefore contribute to the production of a net redshift in a spatially unresolved loop. C1 UNIV CALIF BERKELEY, DEPT ASTRON, BERKELEY, CA 94720 USA. UNIV CALIF LAWRENCE LIVERMORE NATL LAB, INST GEOPHYS & PLANETARY PHYS, LIVERMORE, CA 94550 USA. RP NATL CTR ATMOSPHER RES, HIGH ALTITUDE OBSERV, BOULDER, CO 80307 USA. NR 56 TC 9 Z9 9 U1 0 U2 1 PU IOP PUBLISHING LTD PI BRISTOL PA TEMPLE CIRCUS, TEMPLE WAY, BRISTOL BS1 6BE, ENGLAND SN 0004-637X EI 1538-4357 J9 ASTROPHYS J JI Astrophys. J. PD JUL 10 PY 1991 VL 375 IS 2 BP 800 EP 817 DI 10.1086/170244 PN 1 PG 18 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA FV411 UT WOS:A1991FV41100042 ER PT J AU HALPERN, HJ JAFFE, DR NGUYEN, TD HARAF, DJ SPENCER, DP BOWMAN, MK WEICHSELBAUM, RR DIAMOND, AM AF HALPERN, HJ JAFFE, DR NGUYEN, TD HARAF, DJ SPENCER, DP BOWMAN, MK WEICHSELBAUM, RR DIAMOND, AM TI MEASUREMENT OF BIOREDUCTION RATES OF CELLS WITH DISTINCT RESPONSES TO IONIZING-RADIATION AND CISPLATIN SO BIOCHIMICA ET BIOPHYSICA ACTA LA English DT Article DE RADICAL FORMATION; RADIATION DAMAGE; CISPLATIN; ELECTRON PARAMAGNETIC RESONANCE; (CHINESE HAMSTER OVARY CELL LINE) ID NITROXIDE SPIN LABELS; DNA-DAMAGING AGENTS; LIVING CELLS; RESISTANCE; CIS-DIAMMINEDICHLOROPLATINUM(II); SENSITIVITY; MECHANISMS; LINE AB A low frequency electron paramagnetic resonance (EPR) spectrometer has been used to measure the bioreduction rate of an exogenously added nitroxide free radical species. Measurements have been made in a well controlled, in vitro system using an X-ray and cisplatin sensitive Chinese hamster ovary (CHO) cell line, xrs-5, and partial revertants which display wild-type levels of sensitivity to X-rays but retain xrs-5 levels of cisplatin sensitivity. The xrs-5 cells reduce this radical species at a rate which is approx. 50% that of the wild-type CHO cell line, K1. The partial revertants maintain this defect in bioreduction despite their decrease in radiosensitivity. However, the bioreduction rate observed in these cells correlates with their sensitivity to the chemotherapeutic drug cisplatin. Low frequency EPR allows measurements and imaging of living tissue and may be of value as a predictive assay of human tumor response to chemotherapy. C1 UNIV CHICAGO,MICHAEL REESE HOSP & MED CTR,CTR RADIAT THERAPY,CHICAGO,IL 60616. ARGONNE NATL LAB,DIV CHEM,ARGONNE,IL 60439. RP HALPERN, HJ (reprint author), UNIV CHICAGO,DEPT RADIAT & CELLULAR ONCOL,5841 S MARYLAND AVE,BOX 442,CHICAGO,IL 60637, USA. RI Bowman, Michael/F-4265-2011 OI Bowman, Michael/0000-0003-3464-9409 FU NCI NIH HHS [R01CA42596, R29CA50679] NR 18 TC 6 Z9 6 U1 0 U2 2 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0006-3002 J9 BIOCHIM BIOPHYS ACTA PD JUL 10 PY 1991 VL 1093 IS 2-3 BP 121 EP 124 DI 10.1016/0167-4889(91)90112-B PG 4 WC Biochemistry & Molecular Biology; Biophysics SC Biochemistry & Molecular Biology; Biophysics GA FZ271 UT WOS:A1991FZ27100002 PM 1650577 ER PT J AU WANG, HH KINI, AM SAVALL, BM CARLSON, KD WILLIAMS, JM LYKKE, KR WURZ, P PARKER, DH PELLIN, MJ GRUEN, DM WELP, U KWOK, WK FLESHLER, S CRABTREE, GW AF WANG, HH KINI, AM SAVALL, BM CARLSON, KD WILLIAMS, JM LYKKE, KR WURZ, P PARKER, DH PELLIN, MJ GRUEN, DM WELP, U KWOK, WK FLESHLER, S CRABTREE, GW TI 1ST EASILY REPRODUCED SOLUTION-PHASE SYNTHESIS AND CONFIRMATION OF SUPERCONDUCTIVITY IN THE FULLERENE KXC60 (TC=18.0+/-0.1K) SO INORGANIC CHEMISTRY LA English DT Letter ID AMBIENT-PRESSURE; TC C1 ARGONNE NATL LAB,DIV MAT SCI,ARGONNE,IL 60439. UNIV CALIF IRVINE,DEPT CHEM,IRVINE,CA 92717. RP WANG, HH (reprint author), ARGONNE NATL LAB,DIV CHEM,ARGONNE,IL 60439, USA. RI Pellin, Michael/B-5897-2008; Kini, Aravinda/F-4467-2012 OI Pellin, Michael/0000-0002-8149-9768; NR 15 TC 50 Z9 50 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 JUL 10 PY 1991 VL 30 IS 14 BP 2838 EP 2839 DI 10.1021/ic00014a005 PG 2 WC Chemistry, Inorganic & Nuclear SC Chemistry GA FW786 UT WOS:A1991FW78600005 ER PT J AU HAY, BP AF HAY, BP TI EXTENSION OF MOLECULAR MECHANICS TO HIGH-COORDINATE METAL-COMPLEXES - CALCULATION OF THE STRUCTURES OF AQUA AND NITRATO COMPLEXES OF LANTHANIDE(III) METAL-IONS SO INORGANIC CHEMISTRY LA English DT Article ID CROWN ETHER COMPLEXES; FORCE-FIELD CALCULATIONS; M = LA; CONFORMATIONAL-ANALYSIS; MACROCYCLIC LIGANDS; COBALT(III) COMPLEXES; CRYSTAL-STRUCTURES; ELECTRON-TRANSFER; NONAAQUALANTHANOID(III) TRIS(TRIFLUOROMETHANESULFONATES); THERMODYNAMIC PROPERTIES AB Molecular mechanics methods have been used to calculate the diverse geometries found in 58 known structures of 8- to 12-coordinate aqua- and nitratolanthanide(III) complexes. A simple model based on the replacement of L-M-L bending interactions with nonbonded interactions between the ligand donor atoms and the use of harmonic M-L stretching potentials is shown to yield very reasonable geometric results. A method of structure specification for coordination compounds is presented that allows these calculations to be carried out by using the MM2 program without requiring any software modification. C1 UNIV CALIF LOS ALAMOS SCI LAB,DIV ISOTOPE & NUCL CHEM,LOS ALAMOS,NM 87545. UNIV CALIF LOS ALAMOS SCI LAB,DIV NUCL MAT TECHNOL,LOS ALAMOS,NM 87545. NR 115 TC 75 Z9 75 U1 0 U2 8 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 SN 0020-1669 J9 INORG CHEM JI Inorg. Chem. PD JUL 10 PY 1991 VL 30 IS 14 BP 2876 EP 2884 DI 10.1021/ic00014a011 PG 9 WC Chemistry, Inorganic & Nuclear SC Chemistry GA FW786 UT WOS:A1991FW78600011 ER PT J AU SZPAK, S GABRIEL, CJ SMITH, JJ NOWAK, RJ AF SZPAK, S GABRIEL, CJ SMITH, JJ NOWAK, RJ TI ELECTROCHEMICAL CHARGING OF PD RODS SO JOURNAL OF ELECTROANALYTICAL CHEMISTRY LA English DT Article ID HYDROGEN ABSORPTION; PALLADIUM; METALS; DIFFUSION; DEUTERIUM; KINETICS; SURFACE AB A model describing the electrochemical charging of Pd rods is presented. The essential feature of this model is the coupling of the interfacial processes with the transport of interstitials in the electrode interior. It is shown that boundary conditions arise from the solution of equations governing the elementary adsorption-desorption and adsorption-absorption steps and the symmetry of the electrode. Effects of the choice of rate constants of the elementary steps and the charging current on the surface coverage, the electrode potential and the time required to complete electrode charging are examined. C1 US DOE,WASHINGTON,DC 20545. OFF NAVAL RES,ARLINGTON,VA 22217. RP SZPAK, S (reprint author), USN,CTR OCEAN SYST,SAN DIEGO,CA 92152, USA. NR 28 TC 23 Z9 23 U1 1 U2 3 PU ELSEVIER SCIENCE SA LAUSANNE PI LAUSANNE 1 PA PO BOX 564, 1001 LAUSANNE 1, SWITZERLAND SN 0022-0728 J9 J ELECTROANAL CHEM JI J. Electroanal. Chem. PD JUL 10 PY 1991 VL 309 IS 1-2 BP 273 EP 292 DI 10.1016/0022-0728(91)87019-Z PG 20 WC Chemistry, Analytical; Electrochemistry SC Chemistry; Electrochemistry GA FX823 UT WOS:A1991FX82300019 ER PT J AU TOME, CN WENK, HR CANOVA, GR KOCKS, UF AF TOME, CN WENK, HR CANOVA, GR KOCKS, UF TI SIMULATIONS OF TEXTURE DEVELOPMENT IN CALCITE - COMPARISON OF POLYCRYSTAL PLASTICITY THEORIES SO JOURNAL OF GEOPHYSICAL RESEARCH-SOLID EARTH AND PLANETS LA English DT Article ID SLIP SYSTEM ACTIVITY; TRANSITIONS; SHEAR AB Deformation modelling based on polycrystal plasticity theory has been applied to several rocks. Recently it has been demonstrated that rate sensitivity and heterogeneous deformation can have a significant influence on the activation of slip systems and corresponding texture development. In this study previous predictions for pure shear deformation of calcite with the rigid-plastic fully constrained Taylor theory are compared with those from a visco-plastic Taylor theory, a relaxed Taylor theory and a visco-plastic self-consistent theory. In the case of calcite, texture simulations for all models are similar and conclusions based on earlier data remain valid. There are some quantitative differences and these will be discussed. A new procedure for dealing with mechanical twinning is proposed; it requires the volume fraction of twin reoriented grains to match the twinning fraction given by the twinning shears. C1 FAC SCI METL,PHYS & MECAN MAT LAB,F-57045 METZ,FRANCE. UNIV CALIF LOS ALAMOS SCI LAB,CTR MAT SCI,LOS ALAMOS,NM 87545. UNIV CALIF BERKELEY,DEPT GEOL & GEOPHYS,BERKELEY,CA 94720. RP TOME, CN (reprint author), UNIV NACL ROSARIO,INST FIS ROSARIO,27 FEBRERO 210 BIS,RA-2000 ROSARIO,ARGENTINA. RI Kocks, Fred/E-1159-2011; Tome, Carlos/D-5058-2013 NR 28 TC 23 Z9 23 U1 0 U2 8 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 SN 0148-0227 J9 J GEOPHYS RES-SOLID PD JUL 10 PY 1991 VL 96 IS B7 BP 11865 EP 11875 DI 10.1029/91JB00682 PG 11 WC Geosciences, Multidisciplinary SC Geology GA FW819 UT WOS:A1991FW81900015 ER PT J AU GUTTMANN, GD HENKE, BL KERNER, JA AF GUTTMANN, GD HENKE, BL KERNER, JA TI SOFT-X-RAY DOSIMETRY USING RADIOCHROMIC NYLON FILMS SO NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH SECTION A-ACCELERATORS SPECTROMETERS DETECTORS AND ASSOCIATED EQUIPMENT LA English DT Letter ID SYSTEM AB This Letter reports on the effectiveness of radiachromic nylon films for soft X-ray dosimetry at high radiation doses. The results indicate that the film is not energy-sensitive but does have a dose range. Application of the results to the calibration of the LBL soft X-ray contact microscopy station are discussed. C1 UNIV CALIF BERKELEY LAWRENCE BERKELEY LAB,CTR XRAY OPT,BERKELEY,CA 94720. NR 5 TC 0 Z9 0 U1 0 U2 1 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0168-9002 J9 NUCL INSTRUM METH A JI Nucl. Instrum. Methods Phys. Res. Sect. A-Accel. Spectrom. Dect. Assoc. Equip. PD JUL 10 PY 1991 VL 305 IS 1 BP 216 EP 218 DI 10.1016/0168-9002(91)90538-2 PG 3 WC Instruments & Instrumentation; Nuclear Science & Technology; Physics, Nuclear; Physics, Particles & Fields SC Instruments & Instrumentation; Nuclear Science & Technology; Physics GA FX225 UT WOS:A1991FX22500028 ER PT J AU REDDMANN, H SCHULTZE, H AMBERGER, HD SHALIMOFF, GV EDELSTEIN, NM AF REDDMANN, H SCHULTZE, H AMBERGER, HD SHALIMOFF, GV EDELSTEIN, NM TI ELECTRON-STRUCTURE OF ORGANOMETALLIC COMPLEXES OF THE F-ELEMENTS .27. INTERPRETATION OF THE OPTICAL MAGNETOCHEMICAL, ESR AND NMR PROPERTIES OF NEUTRAL BASE ADDUCTS OF TRIS(ETA-5-CYCLOPENTADIENYL)NEODYMIUM(III) SO JOURNAL OF ORGANOMETALLIC CHEMISTRY LA German DT Article ID FIELD SPLITTING PATTERN; ABSORPTION-SPECTRUM; PARAMETERIZATION AB The absorption spectrum of (Cp-d5)3Nd.THF-d8 in hydrocarbon glasses and run as pellets was measured at room and low temperatures. The bands were assigned based on calculations assuming the crystal field parameters of the Nd complex were the same as for the previously analyzed Cp3Pr.MeTHF. The parameters of an empirical Hamiltonian were fitted to the energies of 96 levels to give an r.m.s. deviation of 26 cm-1. On the basis of the wave functions of the crystal field ground state obtained from these calculations, the observed EPR spectrum of Cp3Nd0.06La0.94.THF could be explained. Making use of the calculated wave functions and eigenvalues the experimentally determined temperature dependence of mu-eff2 of powdered Cp3Nd.THF and of an oriented signel crystal of Cp3Nd.NCCH3 could be simulated. Assuming that the methyl protons of the gamma-picoline ligand of Cp3Nd.gamma-pic and (MeCp)3Nd.gamma-pic, respectively, experience only an NMR shift of dipolar type, the paramagnetic anisotropy chi parallel-to - chi perpendicular-to was estimated. C1 LAWRENCE BERKELEY LAB,DIV MAT & CHEM SCI,BERKELEY,CA 94720. RP REDDMANN, H (reprint author), UNIV HAMBURG,INST ANORGAN & ANGEW CHEM,MARTIN LUTHER KING PL 6,W-2000 HAMBURG 13,GERMANY. NR 31 TC 24 Z9 24 U1 1 U2 10 PU ELSEVIER SCIENCE SA LAUSANNE PI LAUSANNE 1 PA PO BOX 564, 1001 LAUSANNE 1, SWITZERLAND SN 0022-328X J9 J ORGANOMET CHEM JI J. Organomet. Chem. PD JUL 9 PY 1991 VL 411 IS 3 BP 331 EP 345 DI 10.1016/0022-328X(91)83039-7 PG 15 WC Chemistry, Inorganic & Nuclear; Chemistry, Organic SC Chemistry GA FW705 UT WOS:A1991FW70500004 ER PT J AU SHI, DL GORETTA, KC SALEMSUGUI, S MCGINN, PJ CHEN, WH ZHU, N AF SHI, DL GORETTA, KC SALEMSUGUI, S MCGINN, PJ CHEN, WH ZHU, N TI FLUX CREEP AND PINNING POTENTIAL DISTRIBUTION IN ZONE-MELTED YBA2CU3OX SO APPLIED PHYSICS LETTERS LA English DT Article ID CRITICAL CURRENT-DENSITY; IRREVERSIBILITY; STATE AB Magnetic relaxation data have been taken on zone-melted and sintered YBa2Cu3Ox samples over wide temperature and magnetic field ranges. We have found that magnetic relaxation varies greatly in the samples with different microstructures and crystallographic orientations. Flux-creep rates have been found to be reduced in the zone-melted samples owing to large amounts of intragranular crystal defects such as edge dislocations and stacking faults. An important flux-pinning behavior related to the pinning potential distributions has been observed in the samples. The relationship between microstructural orientation and pinning potential distributions in YBa2Cu3Ox is discussed. C1 ARGONNE NATL LAB,DIV MAT & COMPONENTS TECHNOL,ARGONNE,IL 60439. UNIV NOTRE DAME,DEPT ELECT ENGN,NOTRE DAME,IN 46556. RP SHI, DL (reprint author), ARGONNE NATL LAB,DIV MAT SCI,ARGONNE,IL 60439, USA. NR 15 TC 6 Z9 6 U1 0 U2 0 PU AMER INST PHYSICS PI WOODBURY PA CIRCULATION FULFILLMENT DIV, 500 SUNNYSIDE BLVD, WOODBURY, NY 11797-2999 SN 0003-6951 J9 APPL PHYS LETT JI Appl. Phys. Lett. PD JUL 8 PY 1991 VL 59 IS 2 BP 225 EP 227 DI 10.1063/1.105973 PG 3 WC Physics, Applied SC Physics GA FV763 UT WOS:A1991FV76300030 ER PT J AU ZHENG, JQ SHIH, MC WILLIAMS, S LEE, SJ KAJIYAMA, H WANG, XK ZHAO, Z VIANI, K JACOBSON, S DUTTA, P CHANG, RPH KETTERSON, JB ROBERTS, T KAMPWIRTH, RT GRAY, KE AF ZHENG, JQ SHIH, MC WILLIAMS, S LEE, SJ KAJIYAMA, H WANG, XK ZHAO, Z VIANI, K JACOBSON, S DUTTA, P CHANG, RPH KETTERSON, JB ROBERTS, T KAMPWIRTH, RT GRAY, KE TI EFFECT OF OXYGEN PARTIAL-PRESSURE ON THE INSITU GROWTH OF Y-BA-CU-O THIN-FILMS ON SRTIO3 SO APPLIED PHYSICS LETTERS LA English DT Article ID MICROSTRUCTURE; YBACUO; PHASE AB The evolution of YBCO film growth with thickness at various oxygen pressures was observed by in situ synchrotron x-ray diffraction in real time. When the films were deposited at 2 angstrom/s and 730-degrees-C under higher oxygen partial pressures (in an Ar/O2 mixture of 90 mTorr), the nucleation was observed to have c-axis orientation. After the films reached a critical thickness, the growth of the YBCO film changed from c axis to a axis and then propagated epitaxially. This provides evidence that a-axis epitaxial growth nucleates on a c-axis base. The critical thickness reflects the competition between the growth of the c and a axes, which is determined by the oxygen partial pressure in the process of thin-film formation. The a-axis oriented films showed a very sharp rocking curve (less than 0.1-degrees) which indicates a very high structural quality. For very low oxygen partial pressures, the in situ growth process was very similar, but the initial nuclei involve a second phase mixed with a small amount of c-axis "123" phase. The nucleation and growth mechanisms of in situ YBCO films are discussed. C1 NORTHWESTERN UNIV,MAT RES CTR,EVANSTON,IL 60208. ARGONNE NATL LAB,DIV MAT SCI,ARGONNE,IL 60439. RP ZHENG, JQ (reprint author), NORTHWESTERN UNIV,NSF SCI & TECHNOL CTR SUPERCONDUCT,EVANSTON,IL 60208, USA. RI Ketterson, John/B-7234-2009; Chang, R.P.H/B-7505-2009 NR 13 TC 33 Z9 33 U1 1 U2 5 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 JUL 8 PY 1991 VL 59 IS 2 BP 231 EP 233 DI 10.1063/1.105975 PG 3 WC Physics, Applied SC Physics GA FV763 UT WOS:A1991FV76300032 ER PT J AU HAMILTON, CL MA, L RENNER, MW SCOTT, RA AF HAMILTON, CL MA, L RENNER, MW SCOTT, RA TI NI(II) AND NI(I) FORMS OF PENTAALKYLAMIDE DERIVATIVES OF COFACTOR F430 OF METHANOBACTERIUM-THERMOAUTOTROPHICUM SO BIOCHIMICA ET BIOPHYSICA ACTA LA English DT Article DE COFACTOR F430; MASS SPECTROMETRY; EPR; (M-THERMOAUTOTROPHICUM) ID COENZYME-M-REDUCTASE; COMPONENT-C; METHANOGENIC BACTERIA; METHYLREDUCTASE SYSTEM; NICKEL(II) COMPLEXES; STRAIN MARBURG; FACTOR-F430; HETERODISULFIDE; PHOSPHATE; CHEMISTRY AB A series of pentaalkylamide forms of F430 and of its 12,13-diepimer have been generated and characterized. Carbodiimide-assisted N-hydroxysulfosuccinimide activation of all five peripheral carboxylates of the F430 macrocycle allows nucleophilic attack by a number of primary amines (RNH2, R- = CH3-, CH3CH2-, CF3CH2-, CH3(CH2)3-) generating the pentaalkylamide derivatives. The identity of each derivative has been verified by fast-atom bombardment mass spectrometry (FAB-MS). The solubility of these derivatives in aprotic organic solvents varies as the amine alkyl substituent (R-) is changed. Electrochemical measurements have shown that the Ni(II/I) reduction potentials in N,N-dimethylformamide (DMF) are approximately -1 V (Ag/AgCl). Reduction by sodium amalgam in THF generates the Ni(I) form of the F430 diepimer pentabutylamide. The visible and EPR spectra of this Ni(I) species are very similar to the corresponding spectra of Ni(I) F430M (Jaun, B. and Pfaltz, A. (1986) J. Chem. Soc. Chem. Commun. 1327-1329.). C1 UNIV GEORGIA,DEPT CHEM,ATHENS,GA 30602. UNIV GEORGIA,DEPT BIOCHEM,ATHENS,GA 30602. UNIV GEORGIA,CTR METALLOENZYME STUDIES,ATHENS,GA 30602. BROOKHAVEN NATL LAB,DEPT APPL SCI,UPTON,NY 11973. NR 33 TC 14 Z9 15 U1 1 U2 5 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0006-3002 J9 BIOCHIM BIOPHYS ACTA PD JUL 8 PY 1991 VL 1074 IS 2 BP 312 EP 319 DI 10.1016/0304-4165(91)90169-H PG 8 WC Biochemistry & Molecular Biology; Biophysics SC Biochemistry & Molecular Biology; Biophysics GA FV787 UT WOS:A1991FV78700015 PM 1648401 ER PT J AU NOID, DW SUMPTER, BG WUNDERLICH, B AF NOID, DW SUMPTER, BG WUNDERLICH, B TI MOLECULAR-DYNAMICS SIMULATION OF TWIST MOTION IN POLYETHYLENE SO MACROMOLECULES LA English DT Article ID CRYSTALLINE POLYMERS; RELAXATION PROCESSES AB The molecular dynamics technique to simulate polyethylene crystals, described earlier, is used with minor modifications to study the mobility of the defect in crystal environment proposed by Mansfield and Boyd. A gradual 180-degrees twist is added to the central atoms of a polyethylene chain before the beginning of the simulation. It is shown that the defect is mobile and when started below the barrier moves quickly to the nearest edge of the crystal. C1 UNIV TENNESSEE,DEPT CHEM,KNOXVILLE,TN 37996. RP NOID, DW (reprint author), OAK RIDGE NATL LAB,DIV CHEM,OAK RIDGE,TN 37831, USA. RI Sumpter, Bobby/C-9459-2013 OI Sumpter, Bobby/0000-0001-6341-0355 NR 21 TC 42 Z9 43 U1 0 U2 4 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 SN 0024-9297 J9 MACROMOLECULES JI Macromolecules PD JUL 8 PY 1991 VL 24 IS 14 BP 4148 EP 4151 DI 10.1021/ma00014a029 PG 4 WC Polymer Science SC Polymer Science GA FW237 UT WOS:A1991FW23700029 ER PT J AU KIM, MW FETTERS, LJ CHEN, W SHEN, YR AF KIM, MW FETTERS, LJ CHEN, W SHEN, YR TI END-FUNCTIONALIZED POLYMER ADSORPTION STUDY BY EVANESCENT ELLIPSOMETRY SO MACROMOLECULES LA English DT Note ID BLOCK COPOLYMERS; INTERFACE; SOLVENT; SURFACES; CHAINS C1 UNIV CALIF BERKELEY LAWRENCE BERKELEY LAB,DEPT PHYS,DIV MAT SCI,BERKELEY,CA 94720. RP KIM, MW (reprint author), EXXON RES & ENGN CO,CORP RES,ROUTE 22 E,ANNANDALE,NJ 08801, USA. RI Kim, Mahn Won/C-1541-2011 NR 14 TC 8 Z9 8 U1 0 U2 0 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 SN 0024-9297 J9 MACROMOLECULES JI Macromolecules PD JUL 8 PY 1991 VL 24 IS 14 BP 4216 EP 4217 DI 10.1021/ma00014a043 PG 2 WC Polymer Science SC Polymer Science GA FW237 UT WOS:A1991FW23700043 ER PT J AU BINETRUY, P GAILLARD, MK AF BINETRUY, P GAILLARD, MK TI SUPERSYMMETRY BREAKING IN STRING MODELS AND A SOURCE OF HIERARCHY (I) SO NUCLEAR PHYSICS B LA English DT Article ID YANG-MILLS THEORIES; COMPACTIFIED SUPERSTRING MODELS; EFFECTIVE FIELD-THEORY; LINEAR SIGMA MODEL; COSMOLOGICAL CONSTANT; SUPERGRAVITY THEORIES; LOCAL SUPERSYMMETRY; MODULAR INVARIANCE; NEWTONS CONSTANT; N=1 SUPERGRAVITY AB In a certain class of superstring models, supersymmetry is broken in a hidden sector but remains globally conserved in the observable sector of quarks and gluons. We recently identified the symmetry responsible for this property, a noncompact symmetry closely connected with space-time duality. This symmetry is broken by chiral and conformal anomalies, which provides the source of supersymmetry breaking in the observable sector and a possibly large hierarchy of scales. We give here details on our analysis, focussing on the identification of the anomalous terms which provide a source of breaking. C1 LAB ANNECY LE VIEUX PHYS PARTICULES,F-74941 ANNECY LE VIEUX,FRANCE. CERN,CH-1211 GENEVA 23,SWITZERLAND. UNIV CALIF BERKELEY LAWRENCE BERKELEY LAB,DEPT PHYS,BERKELEY,CA 94720. UNIV CALIF BERKELEY LAWRENCE BERKELEY LAB,DIV PHYS,BERKELEY,CA 94720. NR 58 TC 36 Z9 36 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 JUL 8 PY 1991 VL 358 IS 1 BP 121 EP 168 DI 10.1016/0550-3213(91)90534-5 PG 48 WC Physics, Particles & Fields SC Physics GA FR228 UT WOS:A1991FR22800007 ER PT J AU FUJIWARA, T IGARASHI, Y KUBO, J AF FUJIWARA, T IGARASHI, Y KUBO, J TI INVESTIGATION OF ANOMALOUS SCHWINGER TERMS BASED ON THE BATALIN-FRADKIN-VILKOVISKY FORMALISM SO NUCLEAR PHYSICS B LA English DT Article ID DYNAMICAL-SYSTEMS SUBJECT; PATH-INTEGRAL MEASURE; GAUSS LAW CONSTRAINT; QUANTUM FIELD-THEORY; GAUGE-THEORIES; CURRENT-ALGEBRA; COVARIANT QUANTIZATION; OPERATOR QUANTIZATION; SUBSIDIARY CONDITIONS; COMMUTATOR ANOMALIES AB On the basis of the generalized hamiltonian formalism of Batalin, Fradkin and Vilkovisky, we investigate the algebraic structure of the anomalous Schwinger terms that appear in the nilpotency condition and/or the time development of the BRST charge in Yang-Mills theory. These anomalies are shown to satisfy a set of consistency conditions which originate from the (super-)Jacobi identities among (anti-)commutation relations. The consistency conditions are solved in an exhaustive fashion to order h2 and our results are independent of a wide class of regularization schemes and gauge choices. C1 NIIGATA UNIV,FAC EDUC,NIIGATA 95021,JAPAN. BROOKHAVEN NATL LAB,DEPT PHYS,UPTON,NY 11973. KANAZAWA UNIV,COLL LIBERAL ARTS,KANAZAWA,ISHIKAWA 920,JAPAN. RP FUJIWARA, T (reprint author), IBARAKI UNIV,DEPT PHYS,MITO,IBARAKI 310,JAPAN. NR 66 TC 8 Z9 8 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 JUL 8 PY 1991 VL 358 IS 1 BP 195 EP 211 DI 10.1016/0550-3213(91)90537-8 PG 17 WC Physics, Particles & Fields SC Physics GA FR228 UT WOS:A1991FR22800010 ER PT J AU CAHN, RN SUZUKI, M AF CAHN, RN SUZUKI, M TI SCALAR BOUND-STATE IN NONMINIMAL TECHNICOLOR - A SURROGATE HIGGS BOSON SO PHYSICAL REVIEW LETTERS LA English DT Article ID SYMMETRY-BREAKING; PARAMETERS AB Models with many technifermion doublets have enhanced interactions. The one-family technicolor model, which has four doublets, may well have a scalar bound state that resembles a Higgs boson. Using a bubble summation, which is justified in the limit of many isodoublets of technifermions, the binding energy and the decay width of the state can be calculated as a function of the technipion mass. Its partial width into WW and ZZ is of order 10-40 GeV, while the partial width into gluon-gluon is about 0.4 GeV. As a result, this surrogate Higgs boson would be narrow, but copiously produced at very-high-energy hadron colliders. C1 UNIV CALIF BERKELEY,DEPT PHYS,BERKELEY,CA 94720. RP CAHN, RN (reprint author), UNIV CALIF BERKELEY LAWRENCE BERKELEY LAB,BERKELEY,CA 94720, USA. NR 15 TC 12 Z9 12 U1 0 U2 1 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 0031-9007 J9 PHYS REV LETT JI Phys. Rev. Lett. PD JUL 8 PY 1991 VL 67 IS 2 BP 169 EP 172 DI 10.1103/PhysRevLett.67.169 PG 4 WC Physics, Multidisciplinary SC Physics GA FV182 UT WOS:A1991FV18200003 ER PT J AU KELLOGG, GL AF KELLOGG, GL TI DIRECT OBSERVATIONS OF ADATOM-SURFACE-ATOM REPLACEMENT - PT ON NI(110) SO PHYSICAL REVIEW LETTERS LA English DT Article ID EXCHANGE MECHANISM; SELF-DIFFUSION AB Field-ion-microscope observations provide direct evidence that Pt adatoms replace Ni(110) surface atoms at temperatures above 105 K. The directions of the individual displacements in this replacement process are consistent with a model involving concerted motion of the adatom and substrate atom. The activation barrier for the exchange is estimated to be 0.28 eV. RP KELLOGG, GL (reprint author), SANDIA NATL LABS,ALBUQUERQUE,NM 87185, USA. NR 13 TC 73 Z9 73 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 JUL 8 PY 1991 VL 67 IS 2 BP 216 EP 219 DI 10.1103/PhysRevLett.67.216 PG 4 WC Physics, Multidisciplinary SC Physics GA FV182 UT WOS:A1991FV18200015 ER PT J AU PHILLIPS, R CHRZAN, DC AF PHILLIPS, R CHRZAN, DC TI KINETIC PHASE-DIAGRAM FOR CRYSTAL-GROWTH - A (1+1)-DIMENSIONAL MODEL SO PHYSICAL REVIEW LETTERS LA English DT Article ID MOLECULAR-BEAM EPITAXY; SURFACE-GROWTH; DYNAMICS; DIFFUSION; TRANSITION; DEPOSITION; EQUATION AB An outstanding goal in the study of crystal growth is the theoretical determination of optimal growth conditions for a specific surface morphology. We have developed a (1 + 1 )-dimensional crystal-growth model which includes both a tunable substrate temperature and growth rate. A kinetic phase diagram, which reveals the dependence of the interface width dynamical exponent on temperature and growth rate, is constructed. The phase diagram contains two limiting phases described by different exponents. It is also demonstrated that the interface width can be minimized through a suitable choice of substrate temperature and deposition rate. RP PHILLIPS, R (reprint author), SANDIA NATL LABS,LIVERMORE,CA 94551, USA. NR 27 TC 13 Z9 13 U1 0 U2 1 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 0031-9007 J9 PHYS REV LETT JI Phys. Rev. Lett. PD JUL 8 PY 1991 VL 67 IS 2 BP 220 EP 223 DI 10.1103/PhysRevLett.67.220 PG 4 WC Physics, Multidisciplinary SC Physics GA FV182 UT WOS:A1991FV18200016 ER PT J AU WOSNITZA, J CRABTREE, GW WANG, HH CARLSON, KD VASHON, MD WILLIAMS, JM AF WOSNITZA, J CRABTREE, GW WANG, HH CARLSON, KD VASHON, MD WILLIAMS, JM TI ANGULAR-DEPENDENCE OF THE CYCLOTRON EFFECTIVE MASS IN ORGANIC SUPERCONDUCTORS SO PHYSICAL REVIEW LETTERS LA English DT Article ID ELECTRON-SPIN-RESONANCE; CONDUCTOR (BEDT-TTF)2KHG(SCN)4; FERMI-SURFACE; BEDT-TTF; KAPPA-(BEDT-TTF)2CU(NCS)2; (BEDT-TTF)2CU(NCS)2; OSCILLATIONS; (BEDT-TTF)2(NH4)HG(SCN)4; FIELDS; HEAT AB We report measurements of the de Haas-van Alphen (dHvA) effect in the organic superconductors alpha-(BEDT-TTF)2(NH4)Hg(SCN)4 (T(c) almost-equal-to 1 K) and kappa-(BEDT-TTF)2Cu(NCS)2 (T(c) almost-equal-to 10 K) in fields up to 15 T and temperatures down to 0.45 K. For the first time, we determine the angular dependence of the cyclotron effective mass m(c), and the orientation of up to four spin-splitting zeros of the dHvA signal. The angular dependence of the amplitude of the dHvA oscillations is quantitatively explained, and the mass enhancement due to electron-phonon coupling is estimated. C1 ARGONNE NATL LAB,DIV CHEM,ARGONNE,IL 60439. RP WOSNITZA, J (reprint author), ARGONNE NATL LAB,DIV MAT SCI,ARGONNE,IL 60439, USA. NR 26 TC 49 Z9 49 U1 1 U2 2 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 0031-9007 J9 PHYS REV LETT JI Phys. Rev. Lett. PD JUL 8 PY 1991 VL 67 IS 2 BP 263 EP 266 DI 10.1103/PhysRevLett.67.263 PG 4 WC Physics, Multidisciplinary SC Physics GA FV182 UT WOS:A1991FV18200027 ER PT J AU HOLCZER, K KLEIN, O GRUNER, G THOMPSON, JD DIEDERICH, F WHETTEN, RL AF HOLCZER, K KLEIN, O GRUNER, G THOMPSON, JD DIEDERICH, F WHETTEN, RL TI CRITICAL MAGNETIC-FIELDS IN THE SUPERCONDUCTING STATE OF K3C60 SO PHYSICAL REVIEW LETTERS LA English DT Article AB We have measured the temperature dependence of the lower and upper critical fields in superconducting K3C60. From the measurements, we have evaluated the penetration depth (lambda = 2400 angstrom) and superconducting coherence length (zeta = 26 angstrom). The parameters are in agreement with a superconducting state formed by a narrow band. C1 UNIV CALIF LOS ANGELES,CTR SOLID STATE SCI,LOS ANGELES,CA 90024. UNIV CALIF LOS ALAMOS SCI LAB,LOS ALAMOS,NM 87545. HUNGARIAN ACAD SCI,CENT RES INST PHYS,H-1525 BUDAPEST,HUNGARY. RP HOLCZER, K (reprint author), UNIV CALIF LOS ANGELES,DEPT PHYS,LOS ANGELES,CA 90024, USA. NR 11 TC 168 Z9 168 U1 1 U2 7 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 0031-9007 J9 PHYS REV LETT JI Phys. Rev. Lett. PD JUL 8 PY 1991 VL 67 IS 2 BP 271 EP 274 DI 10.1103/PhysRevLett.67.271 PG 4 WC Physics, Multidisciplinary SC Physics GA FV182 UT WOS:A1991FV18200029 ER PT J AU MILLER, CA KERSTEIN, AR TORQUATO, S AF MILLER, CA KERSTEIN, AR TORQUATO, S TI STERICALLY HINDERED FRAGMENTATION IN REACTIVE SOLIDS SO JOURNAL OF PHYSICS A-MATHEMATICAL AND GENERAL LA English DT Article ID INVASION PERCOLATION; MODEL AB A two-dimensional model of a two-phase solid which undergoes a reaction at its surface is used to study the fragmentation of reactive materials in which the morphological hindering of fragment release is considered. Scaling concepts of cluster percolation theory are used to evaluate Monte Carlo data generated from a simulation of the hindered fragmentation process. By defining a hierarchy of fragmentation objects, different scaling exponents are computed for each of these objects as measured by the number of sub-objects they contain. In addition, it appears that each of the different measures of object size exhibits optimum scaling at a different critical reactive-phase mass fraction; simulation data indicate that the critical mass fractions follow a trend consistent with expected physical behaviour of the system. In addition, the critical mass fractions reported correspond to 'virtual' criticalities, i.e. the critical points cannot result in actual divergences in size, but rather are properties of the scaling function. C1 NYU,COURANT INST MATH SCI,NEW YORK,NY 10012. SANDIA NATL LABS,LIVERMORE,CA 94550. RP MILLER, CA (reprint author), N CAROLINA STATE UNIV,DEPT MECH & AEROSP ENGN,RALEIGH,NC 27607, USA. RI Miller, Andrew/C-5777-2011 NR 18 TC 0 Z9 0 U1 0 U2 1 PU IOP PUBLISHING LTD PI BRISTOL PA TECHNO HOUSE, REDCLIFFE WAY, BRISTOL, ENGLAND BS1 6NX SN 0305-4470 J9 J PHYS A-MATH GEN JI J. Phys. A-Math. Gen. PD JUL 7 PY 1991 VL 24 IS 13 BP 3077 EP 3093 DI 10.1088/0305-4470/24/13/022 PG 17 WC Physics, Multidisciplinary; Physics, Mathematical SC Physics GA FW636 UT WOS:A1991FW63600022 ER PT J AU JUSZCZAK, LJ ZILINSKAS, BA GEACINTOV, NE BRETON, J SAUER, K AF JUSZCZAK, LJ ZILINSKAS, BA GEACINTOV, NE BRETON, J SAUER, K TI ORIENTATION AND LINEAR DICHROISM OF MASTIGOCLADUS-LAMINOSUS PHYCOCYANIN TRIMER AND NOSTOC-SP PHYCOCYANIN DODECAMER IN STRETCHED POLY(VINYL ALCOHOL) FILMS SO BIOCHIMICA ET BIOPHYSICA ACTA LA English DT Article DE LINEAR DICHROISM; EXCITON MODEL; PHYCOCYANIN ID CRYSTAL-STRUCTURE DATA; C-PHYCOCYANIN; AGMENELLUM-QUADRUPLICATUM; ELECTRIC-FIELDS; PHYCOBILISOMES; COMPLEXES; PROTEIN; CHROMOPHORES; CHLOROPLASTS; PIGMENTS AB The linear dichroism (LD) spectra of the C-phycocyanin (C-PC) trimer disks oriented in poly(vinyl alcohol) films (PVA) at room temperature and at 95 K were determined. Utilizing the known atomic coordinates of the chromophores (Schirmer, T., Bode, W. and Huber, R. (1987) J. Mol. Biol. 196, 677-695) and theoretical estimates of the orientations of the transition dipole moments relative to the molecular framework, the LD spectra were simulated using the pairwise exciton interaction model of Sauer and Scheer (Biochim. Biophys. Acta 936 (1988) 157-170); in this model, the alpha-84 and beta-84 transition moments are coupled by an exciton mechanism, while the beta-155 chromophore remains uncoupled. Linear dichroism spectra calculated using this exciton model, as well as an uncoupled chromophore (molecular) model, were compared with experimental LD spectra. Satisfactory qualitative agreement can be obtained in both the exciton and molecular models using somewhat different relative values of the theoretically estimated magnitudes of the beta-155 oscillator strength. Because the relative contributions of each of the chromophores (and thus exciton components) to the overall absorption of the C-PC trimer are not known exactly, it is difficult to differentiate successfully between the molecular and exciton models at this time. The linear dichroism spectra of PC dodecamers derived from phycobilisomes of Nostoc sp. oriented in stretched PVA films closely resemble those of the C-PC trimers from Mastigocladus laminosus, suggesting that the phycocyanin chromophores are oriented in a similar manner in both cases, and that neither linker polypeptides nor the state of aggregation have a significant influence on these orientations and linear dichroism spectra. The LD spectra of oriented phycocyanins in stretched PVA films at low temperatures (95 K) appear to be of similar quality and magnitude as the LD spectra of single C-PC crystals (Schirmer, T. and Vincent, M.G. (1987) Biochim. Biophys. Acta 893, 379-385). C1 NYU,DEPT CHEM,NEW YORK,NY 10003. CENS,DEPT BIOL,F-91190 GIF SUR YVETTE,FRANCE. RUTGERS STATE UNIV,COOK COLL,DEPT BIOCHEM & MICROBIOL,NEW BRUNSWICK,NJ 08903. UNIV CALIF BERKELEY LAWRENCE BERKELEY LAB,DEPT CHEM,BERKELEY,CA 94720. UNIV CALIF BERKELEY LAWRENCE BERKELEY LAB,CHEM BIODYNAM LAB,BERKELEY,CA 94720. NR 27 TC 5 Z9 5 U1 0 U2 2 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0006-3002 J9 BIOCHIM BIOPHYS ACTA PD JUL 5 PY 1991 VL 1058 IS 3 BP 363 EP 373 DI 10.1016/S0005-2728(05)80132-X PG 11 WC Biochemistry & Molecular Biology; Biophysics SC Biochemistry & Molecular Biology; Biophysics GA FW346 UT WOS:A1991FW34600005 PM 1905956 ER PT J AU REDDY, NRS SMALL, GJ SEIBERT, M PICOREL, R AF REDDY, NRS SMALL, GJ SEIBERT, M PICOREL, R TI ENERGY-TRANSFER DYNAMICS OF THE B800-B850 ANTENNA COMPLEX OF RHODOBACTER-SPHAEROIDES - A HOLE BURNING STUDY SO CHEMICAL PHYSICS LETTERS LA English DT Article ID ELECTRON-DONOR STATE; LIGHT-HARVESTING COMPLEXES; RESOLUTION OPTICAL-SPECTRA; PHOTOSYNTHETIC BACTERIA; REACTION CENTERS; PURPLE BACTERIA; BURNED SPECTRA; FROZEN-SOLUTIONS; PROTEIN COMPLEX; PHOTOSYSTEM-II AB Hole burned spectra for the B800-B850 bacteriochlorophyll a antenna complex of Rb. sphaeroides chromatophores have been obtained for burn wavelengths ranging from the high-energy side of the B800 absorption profile to the low-energy side of B850 profile. The results indicate that B800-B800 energy transfer at 1.6 K is slow relative to B800 to B850 transfer which occurs in 2.4 ps. Whereas B800 is largely site inhomogeneously broadened, B850 is found to exhibit a homogeneous linewidth of about 220 cm-1 at low temperatures. The latter result is used to explain the temperature independence of the B800 to B850 energy transfer rate. The homogeneous linewidth of 220 cm-1 is argued to be a measure of the exciton bandwidth of B850. It is concluded that B800 and B850 are weakly exciton-coupled and that the mechanism for B800 to B850 energy transfer is most likely of the Forster-type. The B850 vibronic hole structure allows for an identification of bacteriochlorophyll a modes that participate in Forster-transfer. C1 IOWA STATE UNIV SCI & TECHNOL,DEPT CHEM,AMES,IA 50011. SOLAR ENERGY RES INST,PHOTOCONVERS RES BRANCH,GOLDEN,CO 80401. CSIC,E-50080 ZARAGOZA,SPAIN. RP REDDY, NRS (reprint author), IOWA STATE UNIV SCI & TECHNOL,US DOE,AMES LAB,AMES,IA 50011, USA. RI PICOREL, RAFAEL/K-7930-2014 OI PICOREL, RAFAEL/0000-0003-3791-129X NR 60 TC 124 Z9 128 U1 0 U2 3 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0009-2614 J9 CHEM PHYS LETT JI Chem. Phys. Lett. PD JUL 5 PY 1991 VL 181 IS 5 BP 391 EP 399 DI 10.1016/0009-2614(91)90369-K PG 9 WC Chemistry, Physical; Physics, Atomic, Molecular & Chemical SC Chemistry; Physics GA FV217 UT WOS:A1991FV21700002 ER PT J AU MIAOU, SP CHIN, SM AF MIAOU, SP CHIN, SM TI COMPUTING K-SHORTEST PATH FOR NUCLEAR SPENT FUEL HIGHWAY TRANSPORTATION SO EUROPEAN JOURNAL OF OPERATIONAL RESEARCH LA English DT Article DE TRANSPORTATION; NUCLEAR SPENT FUEL; NETWORKS; COMPUTATIONAL ANALYSIS ID HAZARDOUS MATERIALS; ALGORITHMS; NETWORK; LENGTHS AB Four k-shortest path algorithms were implemented to select a set of optimal routes for transporting nuclear spent fuel on the U.S. Interstate highway system. Origin-destination pairs drawn from a selection of six nuclear reactors and two potential repository sites across the U.S. were used for evaluation of the computational performance of each algorithm. The first two algorithms maintained a priority queue under two different management systems, a linear search and a binary heap. The third was an adaptive algorithm which exploited the knowledge of the Euclidean distances between nodes to reduce search effort. The relative effectiveness of these algorithms in determining the k-shortest path was examined in terms of computation time. Finally, a simple (or loopless) path algorithm, which required only a minor modification of the original k-shortest path algorithm, was introduced for situations in which a large set of simple paths was needed. C1 UNIV TENNESSEE,CTR ENERGY ENVIRONM & RESOURCES,KNOXVILLE,TN 37996. RP MIAOU, SP (reprint author), OAK RIDGE NATL LAB,DIV ENERGY,CTR TRANSPORTAT ANAL,POB 2008,MS 6336,5500A,OAK RIDGE,TN 37831, USA. NR 20 TC 15 Z9 26 U1 0 U2 2 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0377-2217 J9 EUR J OPER RES JI Eur. J. Oper. Res. PD JUL 5 PY 1991 VL 53 IS 1 BP 64 EP 80 DI 10.1016/0377-2217(91)90093-B PG 17 WC Management; Operations Research & Management Science SC Business & Economics; Operations Research & Management Science GA FZ111 UT WOS:A1991FZ11100006 ER PT J AU CHA, KW JACOBSON, KB YIM, JJ AF CHA, KW JACOBSON, KB YIM, JJ TI ISOLATION AND CHARACTERIZATION OF GTP CYCLOHYDROLASE-I FROM MOUSE-LIVER - COMPARISON OF NORMAL AND THE HPH-1 MUTANT SO JOURNAL OF BIOLOGICAL CHEMISTRY LA English DT Article ID GUANOSINE TRIPHOSPHATE CYCLOHYDROLASE; DROSOPHILA-MELANOGASTER; PARTIAL-PURIFICATION; HYPERPHENYLALANINEMIA; BIOSYNTHESIS; TETRAHYDROBIOPTERIN; SYNTHETASE; DEFICIENCY; NEOPTERIN; PROTEIN AB GTP cyclohydrolase I, an enzyme that catalyzes the first reaction in the pathway for the biosynthesis of pterin compounds, was purified from of C3H mouse liver by 192-fold to apparent homogeneity, using Ultrogel AcA34, DEAE-Trisacryl, and GTP-agarose gels. Its native molecular weight was estimated at 362,000. When the enzyme was subjected to electrophoresis on a denaturing polyacrylamide gel, only one protein band was evident, and its molecular weight was estimated at 55,700. The NH2-terminal amino acid of this enzyme was serine. These results indicate the enzyme consists of six to eight subunits. No coenzyme or metal ion was required for activity. This enzyme activity was inhibited by most of divalent cations and was slightly activated by potassium ion. The K(m) value for GTP was determined to be 17.3-mu-M. The temperature and pH optima for the activity were 60-degrees-C and pH 8.0-8.5, respectively. The expected products, a dihydroneopterin compound and formic acid, were found in a molar ratio of 1.01. A polyclonal antiserum generated against the purified enzyme was used to compare GTP cyclohydrolase I from the hph-I mutant and normal mouse. The hph-1 mutant liver contained only 8% of normal specific activity, but a normal amount of GTP cyclohydrolase I antigen as compared with the C3H mouse. Subunit molecular weight and electrophoretic behavior of GTP cyclohydrolase I from hph-1 mutant were not different from those of the enzyme from C3H mouse. These results suggest that the hph-1 mutation may involve alteration of the catalytic site but does not detectably alter the whole enzyme structure. C1 SEOUL NATL UNIV,DEPT MICROBIOL,SEOUL 151,SOUTH KOREA. OAK RIDGE NATL LAB,DIV BIOL,OAK RIDGE,TN 37831. NR 29 TC 23 Z9 23 U1 0 U2 0 PU AMER SOC BIOCHEMISTRY MOLECULAR BIOLOGY INC PI BETHESDA PA 9650 ROCKVILLE PIKE, BETHESDA, MD 20814 SN 0021-9258 J9 J BIOL CHEM JI J. Biol. Chem. PD JUL 5 PY 1991 VL 266 IS 19 BP 12294 EP 12300 PG 7 WC Biochemistry & Molecular Biology SC Biochemistry & Molecular Biology GA FV180 UT WOS:A1991FV18000032 PM 1905717 ER PT J AU MEERSSEMAN, G PENNINGS, S BRADBURY, EM AF MEERSSEMAN, G PENNINGS, S BRADBURY, EM TI CHROMATOSOME POSITIONING ON ASSEMBLED LONG CHROMATIN LINKER HISTONES AFFECT NUCLEOSOME PLACEMENT ON 5-S-RDNA SO JOURNAL OF MOLECULAR BIOLOGY LA English DT Article DE CHROMATIN; NUCLEOSOME POSITIONING; 5-S-RDNA; LINKER HISTONE; CHROMATOSOME ID CORE PARTICLE; ALPHA-SATELLITE; DNA; RECONSTITUTION; INVITRO; PERIODICITIES; RESOLUTION C1 UNIV CALIF LOS ALAMOS SCI LAB,DIV LIFE SCI,LOS ALAMOS,NM 87545. RP MEERSSEMAN, G (reprint author), UNIV CALIF DAVIS,SCH MED,DEPT BIOCHEM,DAVIS,CA 95616, USA. FU NIGMS NIH HHS [GM 26901] NR 29 TC 124 Z9 124 U1 0 U2 3 PU ACADEMIC PRESS LTD PI LONDON PA 24-28 OVAL RD, LONDON, ENGLAND NW1 7DX SN 0022-2836 J9 J MOL BIOL JI J. Mol. Biol. PD JUL 5 PY 1991 VL 220 IS 1 BP 89 EP 100 DI 10.1016/0022-2836(91)90383-H PG 12 WC Biochemistry & Molecular Biology SC Biochemistry & Molecular Biology GA FW102 UT WOS:A1991FW10200011 PM 2067021 ER PT J AU PENNINGS, S MEERSSEMAN, G BRADBURY, EM AF PENNINGS, S MEERSSEMAN, G BRADBURY, EM TI MOBILITY OF POSITIONED NUCLEOSOMES ON 5-S-RDNA SO JOURNAL OF MOLECULAR BIOLOGY LA English DT Article DE CHROMATIN; NUCLEOSOME POSITIONING; HISTONE OCTAMER MOBILITY; 5-S-RDNA ID TRANSCRIPTION FACTOR-IIIA; CORE HISTONES; PAIR DNA; SEQUENCE; GENE; PROMOTER; SITES; RNA C1 UNIV CALIF LOS ALAMOS SCI LAB,DIV LIFE SCI,LOS ALAMOS,NM 87545. RP PENNINGS, S (reprint author), UNIV CALIF DAVIS,SCH MED,DEPT BIOL CHEM,DAVIS,CA 95616, USA. FU NIGMS NIH HHS [GM 26901] NR 23 TC 160 Z9 163 U1 0 U2 2 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 JUL 5 PY 1991 VL 220 IS 1 BP 101 EP 110 DI 10.1016/0022-2836(91)90384-I PG 10 WC Biochemistry & Molecular Biology SC Biochemistry & Molecular Biology GA FW102 UT WOS:A1991FW10200012 PM 2067009 ER PT J AU GORETTA, KC ARROYO, RC WU, CT ROUTBORT, JL AF GORETTA, KC ARROYO, RC WU, CT ROUTBORT, JL TI EROSION OF WORK-HARDENED COPPER, NICKEL, AND 304 STAINLESS-STEEL SO WEAR LA English DT Article ID PARTICLE IMPACTS; METALS; ALLOYS AB Solid-particle erosion of three face-centered-cubic metals was studied to determine the effects of prior work hardening, hardness, and ductility on erosion resistance. Erosion rates for the most ductile metal, copper, decreased with increased reduction by cold rolling. The rates for nickel and 304 stainless steel increased for large cold reduction. These increases were attributed to the effects of shear localization and the relatively lower strains to failure for the less ductile metals. The effects of cold rolling on erosion rates were more pronounced for impact at 15-degrees than at 90-degrees. RP GORETTA, KC (reprint author), ARGONNE NATL LAB,ARGONNE,IL 60439, USA. NR 23 TC 20 Z9 20 U1 0 U2 2 PU ELSEVIER SCIENCE SA LAUSANNE PI LAUSANNE 1 PA PO BOX 564, 1001 LAUSANNE 1, SWITZERLAND SN 0043-1648 J9 WEAR JI Wear PD JUL 5 PY 1991 VL 147 IS 1 BP 145 EP 154 DI 10.1016/0043-1648(91)90125-E PG 10 WC Engineering, Mechanical; Materials Science, Multidisciplinary SC Engineering; Materials Science GA FW879 UT WOS:A1991FW87900012 ER PT J AU BRANDSTADTER, A GORETTA, KC ROUTBORT, JL GROPPI, DP KARASEK, KR AF BRANDSTADTER, A GORETTA, KC ROUTBORT, JL GROPPI, DP KARASEK, KR TI SOLID-PARTICLE EROSION OF BISMALEIMIDE POLYMERS SO WEAR LA English DT Article ID WEAR; COMPOSITE; SURFACES; DAMAGE; GLASS AB Solid-particle erosion of bismaleimide (BMI) polymers of various compositions was studied and compared with measured mechanical properties. For angular aluminum oxide erodents of mean diameter 42, 63, 143 or 390-mu-m impacting normal to the surface at 60 m s-1, the erosion rate was found to be a strong function of the size of the impacting particle. Material removal occurred primarily by a process of brittle-fracture-induced damage. However, the results suggest that for the BMI specimens, degradation and plasticity occurred in addition to fracture, and that the occurrence of these phenomena reduced the erosion rates. C1 ALLIED SIGNAL INC,DES PLAINES,IL 60017. RP BRANDSTADTER, A (reprint author), ARGONNE NATL LAB,ARGONNE,IL 60439, USA. NR 28 TC 31 Z9 32 U1 2 U2 6 PU ELSEVIER SCIENCE SA LAUSANNE PI LAUSANNE 1 PA PO BOX 564, 1001 LAUSANNE 1, SWITZERLAND SN 0043-1648 J9 WEAR JI Wear PD JUL 5 PY 1991 VL 147 IS 1 BP 155 EP 164 DI 10.1016/0043-1648(91)90126-F PG 10 WC Engineering, Mechanical; Materials Science, Multidisciplinary SC Engineering; Materials Science GA FW879 UT WOS:A1991FW87900013 ER PT J AU FALKOWSKI, PG ZIEMANN, D KOLBER, Z BIENFANG, PK AF FALKOWSKI, PG ZIEMANN, D KOLBER, Z BIENFANG, PK TI ROLE OF EDDY PUMPING IN ENHANCING PRIMARY PRODUCTION IN THE OCEAN SO NATURE LA English DT Article ID PHOTOSYNTHETIC ENERGY-CONVERSION; PACIFIC-OCEAN; FLUXES; GROWTH AB IN steady-state models of primary production in the open ocean, the upward fluxes of nutrients are balanced by the export of particulate production to the ocean depths. Export production represents the biological effect of carbon production on the net exchange of carbon dioxide between the atmosphere and the ocean. Geochemical estimates of exported production, based on calculations of rates of oxygen usage 1 or heat fluxes 2 are two to three times as high as those determined from biological measurements 3-5. One possible explanation for the differing estimates is that export production, calculated from independent geochemical signals, is too high. Another is that biological measurements severely undersample episodic nutrient injections into the photic zone 1,4. Eddy pumping represents one of the possible mechanisms of nutrient injection 1. Here we examine the enhancement of production by a cyclonic eddy in the subtropical Pacific with instrumentation that allows us to overcome the sampling problem. Our results reveal that eddy pumping markedly stimulates primary production, and that phytoplankton in the upper oligotrophic ocean outside the eddy are not growing near their maximum relative specific growth rates. But if the relative enhancement of production is typical, our results suggest that eddy pumping would enhance total primary production by only approximately 20%. C1 OCEAN INST,WAIMANALO,HI 96795. RP FALKOWSKI, PG (reprint author), BROOKHAVEN NATL LAB,DIV OCEANOG & ATMOSPHER SCI,UPTON,NY 11973, USA. NR 17 TC 320 Z9 328 U1 3 U2 37 PU MACMILLAN MAGAZINES LTD PI LONDON PA 4 LITTLE ESSEX STREET, LONDON, ENGLAND WC2R 3LF SN 0028-0836 J9 NATURE JI Nature PD JUL 4 PY 1991 VL 352 IS 6330 BP 55 EP 58 DI 10.1038/352055a0 PG 4 WC Multidisciplinary Sciences SC Science & Technology - Other Topics GA FV178 UT WOS:A1991FV17800067 ER PT J AU POULIOT, J AUGER, G BRICAULT, P CHAN, Y DORE, D GROULT, S HORN, D HOUDE, S LAFOREST, R PLAGNOL, E ROY, R STPIERRE, C AF POULIOT, J AUGER, G BRICAULT, P CHAN, Y DORE, D GROULT, S HORN, D HOUDE, S LAFOREST, R PLAGNOL, E ROY, R STPIERRE, C TI PROJECTILE EXCITATION-ENERGY EVOLUTION IN PERIPHERAL COLLISIONS FOR O-16+AU-197 AT 32.5, 50 AND 70 MEV/N SO PHYSICS LETTERS B LA English DT Article ID NUCLEON AB A comparison of the multiple breakup of O-16 projectiles scattered by a Au target at three different energies (32.5, 50 and 70 MeV/N) is presented. The excitation energy spectra of the primary projectile-like nuclei decaying into specific output channels were reconstructed. The excitation energy of the target is found to increase faster with beam energy than the one for the quasi-projectile. C1 GRAND ACCELERATEUR NATL IONS LOURDS,F-14021 CAEN,FRANCE. UNIV CALIF BERKELEY LAWRENCE BERKELEY LAB,BERKELEY,CA 94720. UNIV CAEN,PHYS CORPUSCULAIRE LAB,F-14032 CAEN,FRANCE. ATOM ENERGY CANADA LTD,CHALK RIVER NUCL LABS,CHALK RIVER K0J 1J0,ONTARIO,CANADA. RP POULIOT, J (reprint author), UNIV LAVAL,DEPT PHYS,PHYS NUCL LAB,QUEBEC CITY G1K 7P4,QUEBEC,CANADA. NR 13 TC 15 Z9 15 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 JUL 4 PY 1991 VL 263 IS 1 BP 18 EP 22 DI 10.1016/0370-2693(91)91700-6 PG 5 WC Astronomy & Astrophysics; Physics, Nuclear; Physics, Particles & Fields SC Astronomy & Astrophysics; Physics GA FX050 UT WOS:A1991FX05000004 ER PT J AU WUOSMAA, AH BETTS, RR BACK, BB CARPENTER, MP ESBENSEN, H FERNANDEZ, PB GLAGOLA, BG HAPP, T JANSSENS, RVF KHOO, TL MOORE, EF SCARLASSARA, F BENET, P AF WUOSMAA, AH BETTS, RR BACK, BB CARPENTER, MP ESBENSEN, H FERNANDEZ, PB GLAGOLA, BG HAPP, T JANSSENS, RVF KHOO, TL MOORE, EF SCARLASSARA, F BENET, P TI GAMMA-RAY MULTIPLICITY DISTRIBUTIONS IN O-16+SM-152 FUSION NEAR AND BELOW THE COULOMB BARRIER SO PHYSICS LETTERS B LA English DT Article ID HEAVY-ION FUSION; SUBBARRIER FUSION; ANGULAR-MOMENTUM; CROSS-SECTIONS; ENERGIES; PENETRATION; O-16 AB We have studied gamma-ray multiplicity distributions for the system O-16 + 152Sm at five beam energies in the range 60-80 MeV, near and below the Coulomb barrier. The data were obtained using a large array of gamma-ray detectors and an efficient evaporation-residue detector system utilizing an electrostatic deflector. The data are in good agreement with predictions of angular momentum distributions calculated using a coupled-channels model incorporating the effects of deformation. C1 PURDUE UNIV,W LAFAYETTE,IN 47907. RP WUOSMAA, AH (reprint author), ARGONNE NATL LAB,DIV PHYS,ARGONNE,IL 60439, USA. RI Carpenter, Michael/E-4287-2015; OI Carpenter, Michael/0000-0002-3237-5734; Scarlassara, Fernando/0000-0002-4663-8216 NR 25 TC 38 Z9 38 U1 0 U2 0 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0370-2693 J9 PHYS LETT B JI Phys. Lett. B PD JUL 4 PY 1991 VL 263 IS 1 BP 23 EP 28 DI 10.1016/0370-2693(91)91701-V PG 6 WC Astronomy & Astrophysics; Physics, Nuclear; Physics, Particles & Fields SC Astronomy & Astrophysics; Physics GA FX050 UT WOS:A1991FX05000005 ER PT J AU KOGUT, JB SINCLAIR, DK WANG, KC AF KOGUT, JB SINCLAIR, DK WANG, KC TI TOWARDS THE CONTINUUM-LIMIT OF THE THERMODYNAMICS OF LATTICE QCD WITH A REALISTIC QUARK SPECTRUM SO PHYSICS LETTERS B LA English DT Article ID PHASE-TRANSITION; TEMPERATURE AB Lattice QCD with a light isodoublet and a heavier strange quark is simulated on a 6 x 12(3) lattice. Metastability studies on the 6 x 12(3) lattice give considerably weaker evidence for a first order transition than on a 4 X 8(3) lattice. Comparison of chiral condensates and energy densities with similar measurements on 4 x 8(3) and 4 x 12(3) lattices also indicate that the quark - gluon plasma transition becomes less abrupt as the lattice size increases and could be just a crossover phenomenon at the quark masses simulated here. The light quark and strange quark energy densities are suppressed in the transition region and approach their high temperature limits from below. C1 ARGONNE NATL LAB,DIV PHYS,ARGONNE,IL 60439. RP KOGUT, JB (reprint author), UNIV ILLINOIS,DEPT PHYS,1110 W GREEN ST,URBANA,IL 61801, USA. NR 16 TC 52 Z9 52 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 JUL 4 PY 1991 VL 263 IS 1 BP 101 EP 106 DI 10.1016/0370-2693(91)91714-7 PG 6 WC Astronomy & Astrophysics; Physics, Nuclear; Physics, Particles & Fields SC Astronomy & Astrophysics; Physics GA FX050 UT WOS:A1991FX05000018 ER PT J AU DECAMP, D DESCHIZEAUX, B GOY, C LEES, JP MINARD, MN ALEMANY, R CRESPO, JM DELFINO, M FERNANDEZ, E GAITAN, V GARRIDO, L MIR, LM PACHECO, A CATANESI, MG CREANZA, D DEPALMA, M FARILLA, A IASELLI, G MAGGI, G MAGGI, M NATALI, S NUZZO, S QUATTROMINI, M RANIERI, A RASO, G ROMANO, F RUGGIERI, F SELVAGGI, G SILVESTRIS, L TEMPESTA, P ZITO, G GAO, Y HU, H HUANG, D HUANG, X LIN, J LOU, J QIAO, C RUAN, T WANG, T XIE, Y XU, D XU, R ZHANG, J ZHAO, W ATWOOD, WB BAUERDICK, LAT BIRD, F BLUCHER, E BONVICINI, G BOSSI, F BROWN, D BURNETT, TH DREVERMANN, H FORTY, RW GRAB, C HAGELBERG, R HAYWOOD, S HILGART, J JOST, B KASEMANN, M KNOBLOCH, J LACOURT, A LANCON, E LEHRAUS, I LOHSE, T MARCHIORO, A MARTINEZ, M MATO, P MENARY, S MINTEN, A MIOTTO, A MIQUEL, R MOSER, HG NASH, J PALAZZI, P RANJARD, F REDLINGER, G ROTH, A ROTHBERG, J ROTSCHEIDT, H ST DENIS R SCHLATTER, D TAKASHIMA, M TALBY, M TEJESSY, W WACHSMUTH, H WASSERBAECH, S WHEELER, S WIEDENMANN, W WITZELING, W WOTSCHACK, J WU, W AJALTOUNI, Z BARDADIN-OTWINOWSKA, M FALVARD, A EL FELLOUS, R GAY, P HARVEY, J HENRARD, P JOUSSET, J MICHEL, B MONTRET, JC PALLIN, D PERRET, P PRORIOL, J PRULHIERE, F STIMPFL, G HANSEN, JD HANSEN, JR HANSEN, PH MOLLERUD, R NIELSEN, ER NILSSON, BS EFTHYMIOPOULOS, I SIMOPOULOU, E VAYAKI, A BADIER, J BLONDEL, A BONNEAUD, G BOUROTTE, J BRAEMS, F BRIENT, JC FOUQUE, G GAMESS, A GUIRLET, R ORTEU, S ROSOWSKY, A ROUGE, A RUMPF, M TANAKA, R VIDEAU, H CANDLIN, DJ VEITCH, E PARRINI, G CORDEN, M GEORGIOPOULOS, C IKEDA, M LANNUTTI, J LEVINTHAL, D MERMIKIDES, M SAWYER, L ANTONELLI, A BALDINI, R BENCIVENNI, G BOLOGNA, G CAMPANA, P CAPON, G CERUTTI, F CHIARELLA, V D'ETTORRE-PIAZZOLI, B FELICI, G LAURELLI, P MANNOCCHI, G MURTAS, F MURTAS, GP NICOLETTI, G PASSALACQUA, M PEPE-ALTARELLI, M PICCHI, P ZOGRAFOU, P ALTOON, B BOYLE, O HALLEY, AW TEN HAVE, I HEARNS, JL LYNCH, JG MORTON, WT RAINE, C SCARR, JM SMITH, K THOMPSON, AS TURNBULL, RM BRANDL, B BRAUN, O GEIGES, R GEWENIGER, C HANKE, P HEPP, V KLUGE, EE MAUMARY, Y PUTZER, A RENSCH, B STAHL, A TITTEL, K WUNSCH, M BELK, AT BEUSELINCK, R BINNIE, DM CAMERON, W CATTANEO, M DORNAN, PJ DUGEAY, S GREENE, AM LIESKE, NM PATTON, SJ PAYNE, DG PHILLIPS, MJ SEDGBEER, JK TAYLOR, G TOMALIN, IR WRIGHT, AG GIRTLER, P KUHN, D RUDOLPH, G BOWDERY, CK BRODBECK, TJ FINCH, AJ FOSTER, F HUGHES, G KEEMER, NR NUTTALL, M PATEL, A ROWLINGSON, BS SLOAN, T SNOW, SW WHELAN, EP BARCZEWSKI, T KLEINKNECHT, K RAAB, J RENK, B ROEHN, S SANDER, HG SCHMELLING, M SCHMIDT, H STEEG, F WALTHER, SM WOLF, B ALBANESE, JP AUBERT, JJ BENCHOUK, C BERNARD, V BONISSENT, A COURVOISIER, D ETIENNE, F PAPALEXIOU, S PAYRE, P PIETRZYK, B QIAN, Z BECKER, H BLUM, W CATTANEO, P COWAN, G DEHNING, B DIETL, H DYDAK, F FERNANDEZ-BOSMAN, M HANSL-KOZANECKA, T JAHN, A KOZANECKI, W LANGE, E LAUBER, J LUTJENS, G LUTZ, G MANNER, W PAN, Y RICHTER, R SCHRODER, J SCHWARZ, AS SETTLES, R STIERLIN, U THOMAS, J WOLF, G BERTIN, V BOUCROT, J CALLOT, O CHEN, X CORDIER, A GANIS, M GRIVAZ, JF HEUSSE, P JANOT, P KIM, DW LE DIBERDER, F LEFRANCOIS, J LUTZ, AM VEILLET, JJ VIDEAU, I ZHANG, Z ZOMER, F ABBANEO, D AMENDOLIA, SR BAGLIESI, G BATIGNANI, G BOSISIO, L BOTTIGLI, U BRADASCHIA, C CARPINELLI, M CIOCCI, MA DELL'ORSO, R FERRANTE, I FIDECARO, F FOA, L FOCARDI, E FORTI, F GIASSI, A GIORGI, MA LIGABUE, F LUSIANI, A MANNELLI, EB MARROCCHESI, PS MESSINEO, A MONETA, L PALLA, F SANGUINETTI, G STEINBERGER, J TENCHINI, R TONELLI, G TRIGGIANI, G VANNINI, C VENTURI, A VERDINI, PG WALSH, J CARTER, JM GREEN, MG MARCH, PV MEDCALF, T QUAZI, IS SAICH, MR STRONG, JA THOMAS, RM WEST, LR WILDISH, T BOTTERILL, DR CLIFFT, RW EDGECOCK, TR EDWARDS, M FISHER, SM JONES, TJ NORTON, PR SALMON, DP THOMPSON, JC BLOCH-DEVAUX, B COLAS, P KLOPFENSTEIN, C LOCCI, E LOUCATOS, S MONNIER, E PEREZ, P PERLAS, JA PERRIER, F RANDER, J RENARDY, JF ROUSSARIE, A SCHULLER, JP SCHWINDLING, J VALLAGE, B ASHMAN, JG BOOTH, CN BUTTAR, C CARNEY, R CARTWRIGHT, S COMBLEY, F DINSDALE, M DOGRU, M HATFIELD, F MARTIN, J PARKER, D REEVES, P THOMPSON, LF BRANDT, S BURKHARDT, H GRUPEN, C MEINHARD, H MIRABITO, L NEUGEBAUER, E SCHAFER, U SEYWERD, H APOLLINARI, G GIANNINI, G GOBBO, B LIELLO, F RAGUSA, F ROLANDI, L STIEGLER, U BELLANTONI, L BOUDREAU, JF CINABRO, D CHEN, X CONWAY, JS COWEN, DF FENG, Z FERGUSON, DPS GAO, YS GRAHL, J HARTON, JL JACOBSEN, JE JARED, RC JOHNSON, RP LECLAIRE, BW PAN, YB PATER, JR SAADI, Y SHARMA, V SHI, ZH TANG, YH WALSH, AM WEAR, JA WEBER, FV WHITNEY, MH SAU, LW ZOBERNIG, G AF DECAMP, D DESCHIZEAUX, B GOY, C LEES, JP MINARD, MN ALEMANY, R CRESPO, JM DELFINO, M FERNANDEZ, E GAITAN, V GARRIDO, L MIR, LM PACHECO, A CATANESI, MG CREANZA, D DEPALMA, M FARILLA, A IASELLI, G MAGGI, G MAGGI, M NATALI, S NUZZO, S QUATTROMINI, M RANIERI, A RASO, G ROMANO, F RUGGIERI, F SELVAGGI, G SILVESTRIS, L TEMPESTA, P ZITO, G GAO, Y HU, H HUANG, D HUANG, X LIN, J LOU, J QIAO, C RUAN, T WANG, T XIE, Y XU, D XU, R ZHANG, J ZHAO, W ATWOOD, WB BAUERDICK, LAT BIRD, F BLUCHER, E BONVICINI, G BOSSI, F BROWN, D BURNETT, TH DREVERMANN, H FORTY, RW GRAB, C HAGELBERG, R HAYWOOD, S HILGART, J JOST, B KASEMANN, M KNOBLOCH, J LACOURT, A LANCON, E LEHRAUS, I LOHSE, T MARCHIORO, A MARTINEZ, M MATO, P MENARY, S MINTEN, A MIOTTO, A MIQUEL, R MOSER, HG NASH, J PALAZZI, P RANJARD, F REDLINGER, G ROTH, A ROTHBERG, J ROTSCHEIDT, H ST DENIS R SCHLATTER, D TAKASHIMA, M TALBY, M TEJESSY, W WACHSMUTH, H WASSERBAECH, S WHEELER, S WIEDENMANN, W WITZELING, W WOTSCHACK, J WU, W AJALTOUNI, Z BARDADIN-OTWINOWSKA, M FALVARD, A EL FELLOUS, R GAY, P HARVEY, J HENRARD, P JOUSSET, J MICHEL, B MONTRET, JC PALLIN, D PERRET, P PRORIOL, J PRULHIERE, F STIMPFL, G HANSEN, JD HANSEN, JR HANSEN, PH MOLLERUD, R NIELSEN, ER NILSSON, BS EFTHYMIOPOULOS, I SIMOPOULOU, E VAYAKI, A BADIER, J BLONDEL, A BONNEAUD, G BOUROTTE, J BRAEMS, F BRIENT, JC FOUQUE, G GAMESS, A GUIRLET, R ORTEU, S ROSOWSKY, A ROUGE, A RUMPF, M TANAKA, R VIDEAU, H CANDLIN, DJ VEITCH, E PARRINI, G CORDEN, M GEORGIOPOULOS, C IKEDA, M LANNUTTI, J LEVINTHAL, D MERMIKIDES, M SAWYER, L ANTONELLI, A BALDINI, R BENCIVENNI, G BOLOGNA, G CAMPANA, P CAPON, G CERUTTI, F CHIARELLA, V D'ETTORRE-PIAZZOLI, B FELICI, G LAURELLI, P MANNOCCHI, G MURTAS, F MURTAS, GP NICOLETTI, G PASSALACQUA, M PEPE-ALTARELLI, M PICCHI, P ZOGRAFOU, P ALTOON, B BOYLE, O HALLEY, AW TEN HAVE, I HEARNS, JL LYNCH, JG MORTON, WT RAINE, C SCARR, JM SMITH, K THOMPSON, AS TURNBULL, RM BRANDL, B BRAUN, O GEIGES, R GEWENIGER, C HANKE, P HEPP, V KLUGE, EE MAUMARY, Y PUTZER, A RENSCH, B STAHL, A TITTEL, K WUNSCH, M BELK, AT BEUSELINCK, R BINNIE, DM CAMERON, W CATTANEO, M DORNAN, PJ DUGEAY, S GREENE, AM LIESKE, NM PATTON, SJ PAYNE, DG PHILLIPS, MJ SEDGBEER, JK TAYLOR, G TOMALIN, IR WRIGHT, AG GIRTLER, P KUHN, D RUDOLPH, G BOWDERY, CK BRODBECK, TJ FINCH, AJ FOSTER, F HUGHES, G KEEMER, NR NUTTALL, M PATEL, A ROWLINGSON, BS SLOAN, T SNOW, SW WHELAN, EP BARCZEWSKI, T KLEINKNECHT, K RAAB, J RENK, B ROEHN, S SANDER, HG SCHMELLING, M SCHMIDT, H STEEG, F WALTHER, SM WOLF, B ALBANESE, JP AUBERT, JJ BENCHOUK, C BERNARD, V BONISSENT, A COURVOISIER, D ETIENNE, F PAPALEXIOU, S PAYRE, P PIETRZYK, B QIAN, Z BECKER, H BLUM, W CATTANEO, P COWAN, G DEHNING, B DIETL, H DYDAK, F FERNANDEZ-BOSMAN, M HANSL-KOZANECKA, T JAHN, A KOZANECKI, W LANGE, E LAUBER, J LUTJENS, G LUTZ, G MANNER, W PAN, Y RICHTER, R SCHRODER, J SCHWARZ, AS SETTLES, R STIERLIN, U THOMAS, J WOLF, G BERTIN, V BOUCROT, J CALLOT, O CHEN, X CORDIER, A GANIS, M GRIVAZ, JF HEUSSE, P JANOT, P KIM, DW LE DIBERDER, F LEFRANCOIS, J LUTZ, AM VEILLET, JJ VIDEAU, I ZHANG, Z ZOMER, F ABBANEO, D AMENDOLIA, SR BAGLIESI, G BATIGNANI, G BOSISIO, L BOTTIGLI, U BRADASCHIA, C CARPINELLI, M CIOCCI, MA DELL'ORSO, R FERRANTE, I FIDECARO, F FOA, L FOCARDI, E FORTI, F GIASSI, A GIORGI, MA LIGABUE, F LUSIANI, A MANNELLI, EB MARROCCHESI, PS MESSINEO, A MONETA, L PALLA, F SANGUINETTI, G STEINBERGER, J TENCHINI, R TONELLI, G TRIGGIANI, G VANNINI, C VENTURI, A VERDINI, PG WALSH, J CARTER, JM GREEN, MG MARCH, PV MEDCALF, T QUAZI, IS SAICH, MR STRONG, JA THOMAS, RM WEST, LR WILDISH, T BOTTERILL, DR CLIFFT, RW EDGECOCK, TR EDWARDS, M FISHER, SM JONES, TJ NORTON, PR SALMON, DP THOMPSON, JC BLOCH-DEVAUX, B COLAS, P KLOPFENSTEIN, C LOCCI, E LOUCATOS, S MONNIER, E PEREZ, P PERLAS, JA PERRIER, F RANDER, J RENARDY, JF ROUSSARIE, A SCHULLER, JP SCHWINDLING, J VALLAGE, B ASHMAN, JG BOOTH, CN BUTTAR, C CARNEY, R CARTWRIGHT, S COMBLEY, F DINSDALE, M DOGRU, M HATFIELD, F MARTIN, J PARKER, D REEVES, P THOMPSON, LF BRANDT, S BURKHARDT, H GRUPEN, C MEINHARD, H MIRABITO, L NEUGEBAUER, E SCHAFER, U SEYWERD, H APOLLINARI, G GIANNINI, G GOBBO, B LIELLO, F RAGUSA, F ROLANDI, L STIEGLER, U BELLANTONI, L BOUDREAU, JF CINABRO, D CHEN, X CONWAY, JS COWEN, DF FENG, Z FERGUSON, DPS GAO, YS GRAHL, J HARTON, JL JACOBSEN, JE JARED, RC JOHNSON, RP LECLAIRE, BW PAN, YB PATER, JR SAADI, Y SHARMA, V SHI, ZH TANG, YH WALSH, AM WEAR, JA WEBER, FV WHITNEY, MH SAU, LW ZOBERNIG, G CA ALEPH Collaboration TI CHARGED-PARTICLE PAIR PRODUCTION ASSOCIATED WITH A LEPTON PAIR IN Z-DECAYS - INDICATION OF AN EXCESS IN THE TAU CHANNEL SO PHYSICS LETTERS B LA English DT Article ID PION FORM-FACTOR; REGION AB In a sample of 200 000 Z decays, events with two leptons and an additional pair of charged particles are studied. The 35 events found show a possible excess in the tau channel compared with the expectation from electroweak processes. The features of the events are consistent with radiation of virtual photons. C1 CNRS, IN2P3, LAB PHYS PARTICULES LAPP, F-74019 ANNECY LE VIEUX, FRANCE. UNIV AUTONOMA BARCELONA, LAB FIS ALTA ENERGIES, E-08193 BELLATERRA, BARCELONA, SPAIN. IST NAZL FIS NUCL, SEZ BARI, I-70126 BARI, ITALY. IST NAZL FIS NUCL, DIPARTIMENTO FIS UNIV, I-70126 BARI, ITALY. ACAD SINICA, INST HIGH ENERGY PHYS, BEIJING, PEOPLES R CHINA. SLAC, STANFORD, CA 94309 USA. UNIV WASHINGTON, Seattle, WA 98195 USA. CERN, EUROPEAN LAB PARTICLE PHYS, CH-1211 Geneva 23, SWITZERLAND. UNIV BLAISE PASCAL, LAB PHYS CORPUSCULAIRE, F-63177 AUBIERE, FRANCE. NIELS BOHR INST, DK-2100 Copenhagen, DENMARK. NUCL RES CTR DEMOKRITOS NRCD, Athens, GREECE. ECOLE POLYTECH, CNRS, IN2P3, LAB PHYS NUCL & HAUTES ENERGIES, F-91128 PALAISEAU, FRANCE. UNIV EDINBURGH, DEPT PHYS, EDINBURGH EH9 3JZ, ENGLAND. UNIV FIRENZE, DIPARTIMENTO FIS, I-50125 FLORENCE, ITALY. IST NAZL FIS NUCL, SEZ FIRENZE, I-50125 FLORENCE, ITALY. FLORIDA STATE UNIV, SUPERCOMP COMPUTAT RES INST, TALLAHASSEE, FL 32306 USA. FLORIDA STATE UNIV, DEPT PHYS, TALLAHASSEE, FL 32306 USA. IST NAZL FIS NUCL, LNF, I-00044 FRASCATI, ITALY. UNIV GLASGOW, DEPT PHYS & ASTRON, GLASGOW G12 8QQ, LANARK, SCOTLAND. UNIV HEIDELBERG, INST HOCHENERGIEPHYS, W-6900 HEIDELBERG, GERMANY. IMPERIAL COLL, DEPT PHYS, LONDON SW7 2BZ, ENGLAND. UNIV INNSBRUCK, INST EXPT PHYS, A-6020 INNSBRUCK, AUSTRIA. UNIV LANCASTER, DEPT PHYS, LANCASTER LA1 4YB, ENGLAND. UNIV MAINZ, INST PHYS, W-6500 MAINZ, GERMANY. CNRS, IN2P3, FAC SCI LUMINY, CTR PHYS PARTICULES, F-13288 MARSEILLE, FRANCE. WERNER HEISENBERG INST PHYS, MAX PLANCK INST PHYS & ASTROPHYS, W-8000 MUNICH, GERMANY. UNIV PARIS SUD, CNRS, IN2P3, LAB ACCELERATEUR LINEAIRE, F-91405 ORSAY, FRANCE. UNIV PISA, DIPARTIMENTO FIS, INFN, SEZ PISA, I-56010 PISA, ITALY. SCUOLA NORMALE SUPER, I-56010 PISA, ITALY. UNIV LONDON, ROYAL HOLLOWAY & BEDFORD NEW COLL, DEPT PHYS, SURREY TW20 0EX, ENGLAND. RUTHERFORD APPLETON LAB, PARTICLE PHYS DEPT, DIDCOT OX11 0QX, OXON, ENGLAND. CEN SACLAY, DEPT PHYS PARTICULES ELEMENTAIRES, F-91191 GIF SUR YVETTE, FRANCE. UNIV SHEFFIELD, DEPT PHYS, SHEFFIELD S3 7RH, ENGLAND. UNIV SIEGEN, FACHBEREICH PHYS, W-5900 SIEGEN, GERMANY. UNIV TRIESTE, DIPARTIMENTO FIS, I-34127 TRIESTE, ITALY. IST NAZL FIS NUCL, SEZ TRIESTE, I-34127 TRIESTE, ITALY. UNIV WISCONSIN, DEPT PHYS, MADISON, WI 53706 USA. FAC SCI, CTR PHYS PARTICULES, F-13288 MARSEILLE, FRANCE. UNIV TORINO, IST FIS GEN, Turin, ITALY. CNR, IST COSMO GEOFIS, I-10126 Turin, ITALY. CERN, PPE Div, CH-1211 Geneva 23, SWITZERLAND. LBL, Berkeley, CA 94720 USA. RP DECAMP, D (reprint author), CNRS, IN2P3, LAB PHYS PARTICULES LAPP, F-74019 ANNECY LE VIEUX, FRANCE. RI Lusiani, Alberto/A-3329-2016; Venturi, Andrea/J-1877-2012; Perrier, Frederic/A-5953-2011; Rolandi, Luigi (Gigi)/E-8563-2013; Colas, Paul/F-2876-2013; Bosman, Martine/J-9917-2014; Fernandez, Enrique/L-5387-2014; Mir, Lluisa-Maria/G-7212-2015; ciocci, maria agnese /I-2153-2015; Lusiani, Alberto/N-2976-2015; Marrocchesi, Pier Simone/N-9068-2015; Forti, Francesco/H-3035-2011; Murtas, Fabrizio/B-5729-2012; Booth, Christopher/B-5263-2016; Delfino, Manuel/A-1545-2012; Pacheco Pages, Andres/C-5353-2011; Ferrante, Isidoro/F-1017-2012; Ligabue, Franco/F-3432-2014; OI Lusiani, Alberto/0000-0002-6876-3288; Rolandi, Luigi (Gigi)/0000-0002-0635-274X; Bosman, Martine/0000-0002-7290-643X; Fernandez, Enrique/0000-0002-6405-9488; Mir, Lluisa-Maria/0000-0002-4276-715X; ciocci, maria agnese /0000-0003-0002-5462; Lusiani, Alberto/0000-0002-6876-3288; Marrocchesi, Pier Simone/0000-0003-1966-140X; Forti, Francesco/0000-0001-6535-7965; Booth, Christopher/0000-0002-6051-2847; Delfino, Manuel/0000-0002-9468-4751; Pacheco Pages, Andres/0000-0001-8210-1734; Ferrante, Isidoro/0000-0002-0083-7228; Palazzi, Paolo/0000-0002-4861-391X; RASO, Giuseppe/0000-0002-5660-3711; Bottigli, Ubaldo/0000-0002-0666-3433; Ligabue, Franco/0000-0002-1549-7107; Bloch-Devaux, Brigitte/0000-0002-2463-1232; Murtas, Fabrizio/0000-0002-7041-6541; Garrido Beltran, Lluis/0000-0001-8883-6539; Edgecock, Rob/0000-0002-7896-3312; Miquel, Ramon/0000-0002-6610-4836 NR 12 TC 18 Z9 18 U1 0 U2 2 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0370-2693 J9 PHYS LETT B JI Phys. Lett. B PD JUL 4 PY 1991 VL 263 IS 1 BP 112 EP 122 DI 10.1016/0370-2693(91)91716-9 PG 11 WC Astronomy & Astrophysics; Physics, Nuclear; Physics, Particles & Fields SC Astronomy & Astrophysics; Physics GA FX050 UT WOS:A1991FX05000020 ER PT J AU REHR, JJ DELEON, JM ZABINSKY, SI ALBERS, RC AF REHR, JJ DELEON, JM ZABINSKY, SI ALBERS, RC TI THEORETICAL X-RAY ABSORPTION FINE-STRUCTURE STANDARDS SO JOURNAL OF THE AMERICAN CHEMICAL SOCIETY LA English DT Article ID NEAR-EDGE STRUCTURE; MULTIPLE-SCATTERING THEORY; STRUCTURE SPECTROSCOPY; ABINITIO CALCULATIONS; STRUCTURE AMPLITUDES; PHASE FUNCTIONS; STRUCTURE EXAFS; POTENTIALS AB Theoretical X-ray absorption fine structure (XAFS) standards are developed for arbitrary pairs of atoms throughout the periodic table (Z less-than-or-equal-to 94). These standard XAFS spectra are obtained from ab initio single-scattering XAFS calculations, using an automated code, FEFF, which takes into account the most important features in current theories: (i) an exact treatment of curved-wave effects; (ii) approximate molecular potentials derived from relativistic atoms, (iii) a complex, energy-dependent self-energy; (iv) a well defined energy reference. FEFF also yields tables of XAFS phases and amplitudes as well as mean-free paths. Sample results are presented and compared with experimental results and with earlier work. We find that these theoretical standards are competitive with experimental standards, permitting XAFS analysis at lower wavenumbers and yielding distance determinations typically better than 0.02 angstrom and coordination numbers typically better than 20%. These standards also provide theoretical tests of chemical transferability in XAFS. C1 LOS ALAMOS NATL LAB,DIV THEORET,LOS ALAMOS,NM 87545. RP REHR, JJ (reprint author), UNIV WASHINGTON,DEPT PHYS,FM-15,SEATTLE,WA 98195, USA. NR 44 TC 1594 Z9 1595 U1 24 U2 158 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 JUL 3 PY 1991 VL 113 IS 14 BP 5135 EP 5140 DI 10.1021/ja00014a001 PG 6 WC Chemistry, Multidisciplinary SC Chemistry GA FU900 UT WOS:A1991FU90000001 ER PT J AU SAETHRE, LJ SIGGEL, MRF THOMAS, TD AF SAETHRE, LJ SIGGEL, MRF THOMAS, TD TI MOLECULAR CHARGE-DISTRIBUTION, CORE-IONIZATION ENERGIES, AND THE POINT-CHARGE APPROXIMATION SO JOURNAL OF THE AMERICAN CHEMICAL SOCIETY LA English DT Article ID X-RAY PHOTOELECTRON; ELECTRON BINDING-ENERGIES; AUGER-PARAMETER; PHOSPHORUS-COMPOUNDS; HYDROCARBON PROPERTIES; THEORETICAL-ANALYSIS; GERMANIUM COMPOUNDS; STATIC RELAXATION; CARBOXYLIC-ACIDS; CHEMICAL-SHIFTS AB Charge distributions in molecules are frequently studied experimentally with core-ionization spectroscopy and analyzed in terms of a potential model that assigns point charges at the atomic centers. This point-charge model has been evaluated by extensive ab initio calculations and the use of Bader's partitioning algorithm of electron density. With ethene and the monohalogenated ethenes as examples, it is shown that the model cannot describe properly the charge distribution and potentials at the atomic centers. It is necessary to consider both a valence radius that varies with atomic charge and the nonspherical distribution of electrons around the atoms in the molecule. The rather small atomic charges derived from the analysis of core-ionization energies with a point-charge model result from ignoring this nonspherical nature of the charge distributions. A possible improvement on the traditional point-charge model is a multipole expansion. It is shown that it is necessary to carry such an expansion at least through the octupole terms to obtain a reasonably accurate description of shifts in potentials. For absolute potentials, even higher multipoles will be needed. C1 LAWRENCE BERKELEY LAB,BERKELEY,CA 94720. UNIV CALIF BERKELEY,DEPT CHEM,BERKELEY,CA 94720. OREGON STATE UNIV,DEPT CHEM,CORVALLIS,OR 97331. OREGON STATE UNIV,CTR ADV MAT RES,CORVALLIS,OR 97331. RP SAETHRE, LJ (reprint author), UNIV TROMSO,INST MATH & PHYS SCI,DEPT CHEM,N-9000 TROMSO,NORWAY. NR 76 TC 20 Z9 20 U1 0 U2 1 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 SN 0002-7863 J9 J AM CHEM SOC JI J. Am. Chem. Soc. PD JUL 3 PY 1991 VL 113 IS 14 BP 5224 EP 5230 DI 10.1021/ja00014a014 PG 7 WC Chemistry, Multidisciplinary SC Chemistry GA FU900 UT WOS:A1991FU90000014 ER PT J AU BEUHLER, RJ FRIEDLANDER, G FRIEDMAN, L AF BEUHLER, RJ FRIEDLANDER, G FRIEDMAN, L TI FUSION REACTIONS IN DENSE HOT ATOM ASSEMBLIES GENERATED BY CLUSTER IMPACT SO ACCOUNTS OF CHEMICAL RESEARCH LA English DT Article ID SURFACES; TARGETS RP BEUHLER, RJ (reprint author), BROOKHAVEN NATL LAB,DEPT CHEM,UPTON,NY 11973, USA. NR 18 TC 3 Z9 3 U1 0 U2 0 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 SN 0001-4842 J9 ACCOUNTS CHEM RES JI Accounts Chem. Res. PD JUL PY 1991 VL 24 IS 7 BP 198 EP 202 DI 10.1021/ar00007a002 PG 5 WC Chemistry, Multidisciplinary SC Chemistry GA FZ037 UT WOS:A1991FZ03700002 ER PT J AU GALBRAITH, HW LOUCK, JD AF GALBRAITH, HW LOUCK, JD TI CANONICAL SOLUTION OF THE SU(3)-DOWN-SO(3) REDUCTION PROBLEM FROM THE SU(3) PATTERN CALCULUS SO ACTA APPLICANDAE MATHEMATICAE LA English DT Article DE SU(3)-DOWN-SO(3) GROUP-SUBGROUP REDUCTION; MULTIPLICITY FUNCTION; UNITARY GROUP PATTERN CALCULUS; CANONICAL SOLUTION ID STATE LABELING PROBLEM; LITTLEWOOD BRANCHING RULE; SUPERSET-OF SO(N); TENSOR-OPERATORS; UNITARY GROUPS; STRUCTURAL-PROPERTIES; ORTHONORMAL BASIS; MATRIX-ELEMENTS; U(3); TRANSFORMATIONS AB Because of its numerous applications to physics, there have been many solutions published on the problem of reducing a given irreducible representation (irrep) of the unitary unimodular group SU(3) into irreps of the proper orthogonal subgroup SO(3). Such solutions are generally based on an arbitrary construction of a nonorthogonal basis of the highest weight space for an irrep of SO(3), followed by an equally arbitrary orthonormalization procedure. This paper presents a unique solution of this problem based on the intrinsic structure of the multiplicity function, which is a function M(L)(p,q) giving the number of times irrep[L] of SO(3) is contained in irrep[pq0] of SU(3). This structure is implemented uniquely into the reduction problem through the use of the SU(3) pattern calculus. C1 UNIV CALIF LOS ALAMOS SCI LAB,DIV THEORET,LOS ALAMOS,NM 87545. NR 33 TC 2 Z9 2 U1 0 U2 0 PU KLUWER ACADEMIC PUBL PI DORDRECHT PA SPUIBOULEVARD 50, PO BOX 17, 3300 AA DORDRECHT, NETHERLANDS SN 0167-8019 J9 ACTA APPL MATH JI Acta Appl. Math. PD JUL PY 1991 VL 24 IS 1 BP 59 EP 108 PG 50 WC Mathematics, Applied SC Mathematics GA GJ080 UT WOS:A1991GJ08000003 ER PT J AU CHENG, XD SCHOENBORN, BP AF CHENG, XD SCHOENBORN, BP TI REPULSIVE RESTRAINTS FOR HYDROGEN-BONDING IN LEAST-SQUARES REFINEMENT OF PROTEIN CRYSTALS - A NEUTRON-DIFFRACTION STUDY OF MYOGLOBIN CRYSTALS SO ACTA CRYSTALLOGRAPHICA SECTION A LA English DT Article AB The purpose of this article is to describe stereochemical restraints on hydrogen bonding within proteins and their associated solvent which can be included in the refinement (PROLSQ) of X-ray or neutron structures of protein crystals. The parameters which define the geometry of hydrogen bonding, ie. the correlation between distances and angles, are based on the results of an analysis of hydrogen bonding in crystal structures of myoglobin derivatives analyzed by neutron diffraction. C1 BROOKHAVEN NATL LAB,DEPT BIOL,CTR STRUCT BIOL,UPTON,NY 11973. SUNY STONY BROOK,DEPT PHYS,STONY BROOK,NY 11794. NR 6 TC 13 Z9 13 U1 1 U2 1 PU MUNKSGAARD INT PUBL LTD PI COPENHAGEN PA 35 NORRE SOGADE, PO BOX 2148, DK-1016 COPENHAGEN, DENMARK SN 0108-7673 J9 ACTA CRYSTALLOGR A JI Acta Crystallogr. Sect. A PD JUL 1 PY 1991 VL 47 BP 314 EP 317 DI 10.1107/S010876739001426X PN 4 PG 4 WC Chemistry, Multidisciplinary; Crystallography SC Chemistry; Crystallography GA FY900 UT WOS:A1991FY90000002 ER PT J AU MITCHELL, TE HIRTH, JP AF MITCHELL, TE HIRTH, JP TI THE SHAPE, CONFIGURATION AND STRESS-FIELD OF TWINS AND MARTENSITE PLATES SO ACTA METALLURGICA ET MATERIALIA LA English DT Article ID MICROSTRUCTURE AB It is shown that the equilibrium shape of a twin or martensite plate can be calculated by treating the interface as a distributed array of dislocations and by calculating their equilibrium distribution. The shape of an isolated twin is an ellipse to first approximation. Second approximation treatments show that the tip of the twin sharpens with increasing stress for the screw dislocation case while it becomes blunter with increasing stress for the edge dislocation case. A colony of twins is treated in much the same way as a stacked array of piled-up dislocations for the screw dislocation case. It is found that the twins flatten out with decreasing separation. Expressions are derived for the stress-field and for the strain energy of such stacked twins. It is shown that the twin spacing should be proportional to the square root of the twin length, from which the twin boundary energy can be calculated. C1 WASHINGTON STATE UNIV, DEPT MECH & MAT ENGN, PULLMAN, WA 99164 USA. RP MITCHELL, TE (reprint author), UNIV CALIF LOS ALAMOS SCI LAB, CTR MAT SCI, LOS ALAMOS, NM 87545 USA. NR 16 TC 41 Z9 41 U1 2 U2 10 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 JUL PY 1991 VL 39 IS 7 BP 1711 EP 1717 DI 10.1016/0956-7151(91)90260-8 PG 7 WC Materials Science, Multidisciplinary; Metallurgy & Metallurgical Engineering SC Materials Science; Metallurgy & Metallurgical Engineering GA FV363 UT WOS:A1991FV36300036 ER PT J AU JACOB, A AF JACOB, A TI COMPARATIVE-STUDY OF INJECTION LOCKED FET OSCILLATORS SO AEU-ARCHIV FUR ELEKTRONIK UND UBERTRAGUNGSTECHNIK-INTERNATIONAL JOURNAL OF ELECTRONICS AND COMMUNICATIONS LA English DT Article AB A study of injection locked FET oscillators (ILO) is presented. Starting from large signal design considerations a comparison between reflection- and transmission-type injection locking is drawn. Bandwidth capabilities and the transfer of modulated signals are investigated by both experiments and computer simulations. In the examples studied the reflection type ILO shows superior performances. RP JACOB, A (reprint author), UNIV CALIF BERKELEY LAWRENCE BERKELEY LAB,1 CYCLOTRON RD,BERKELEY,CA 94720, USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU S HIRZEL VERLAG PI STUTTGART PA POSTFACH 10 10 61, D-70 009 STUTTGART, GERMANY SN 0001-1096 J9 AEU-ARCH ELEKTRON UB JI AEU- Arch. Elektron. Ubertrag.tech.-Int. J. Electron. Commun. PD JUL PY 1991 VL 45 IS 4 BP 261 EP 272 PG 12 WC Engineering, Electrical & Electronic; Telecommunications SC Engineering; Telecommunications GA FY251 UT WOS:A1991FY25100007 ER PT J AU FOURGUETTE, DC MUNGAL, MG DIBBLE, RW AF FOURGUETTE, DC MUNGAL, MG DIBBLE, RW TI TIME EVOLUTION OF THE SHEAR-LAYER OF A SUPERSONIC AXISYMMETRICAL JET SO AIAA JOURNAL LA English DT Article ID MIXING LAYERS; TURBULENT; VELOCITY AB We used a two-laser two-detector experiment to investigate the temporal evolution of the mixing layer of a pressure matched supersonic jet at an exit Mach number of 1.5. discharging into still air, resulting in a convective Mach number of 0.7. The convective speed of the structures present in the flow was measured and compared with previous findings. Additional views of the mixing layer provided information on the three dimensionality of the mixing layer. We found that the structures travel with a velocity higher thin the predicted velocity and they rotate as they progress downstream. C1 STANFORD UNIV,DEPT MECH ENGN,STANFORD,CA 94305. SANDIA NATL LABS,LIVERMORE,CA 94550. RP FOURGUETTE, DC (reprint author), WELLESLEY COLL,DEPT PHYS,WELLESLEY,MA 02181, USA. NR 24 TC 44 Z9 44 U1 0 U2 5 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 JUL PY 1991 VL 29 IS 7 BP 1123 EP 1130 DI 10.2514/3.10712 PG 8 WC Engineering, Aerospace SC Engineering GA FZ702 UT WOS:A1991FZ70200012 ER PT J AU MAZER, JJ STEVENSON, CM EBERT, WL BATES, JK AF MAZER, JJ STEVENSON, CM EBERT, WL BATES, JK TI THE EXPERIMENTAL HYDRATION OF OBSIDIAN AS A FUNCTION OF RELATIVE-HUMIDITY AND TEMPERATURE SO AMERICAN ANTIQUITY LA English DT Article ID GLASSES; RATES; WATER C1 ARCHAEOL & HIST CONSULTANTS INC,CTR HALL,PA 16828. RP MAZER, JJ (reprint author), ARGONNE NATL LAB,ARGONNE,IL 60439, USA. NR 28 TC 27 Z9 27 U1 1 U2 2 PU SOC AMER ARCHAEOLOGY AMERICAN ANTIQUITY PI WASHINGTON PA 900 SECOND ST., NE #12 ATTN: BRIGHID BRADY-DE LAMBERT, WASHINGTON, DC 20002-3557 SN 0002-7316 J9 AM ANTIQUITY JI Am. Antiq. PD JUL PY 1991 VL 56 IS 3 BP 504 EP 513 DI 10.2307/280898 PG 10 WC Anthropology; Archaeology SC Anthropology; Archaeology GA FV147 UT WOS:A1991FV14700008 ER PT J AU GREEN, TM AKINC, M AF GREEN, TM AKINC, M TI SHAPE FORMING OF SUPERCONDUCTING CERAMICS SO AMERICAN CERAMIC SOCIETY BULLETIN LA English DT Article ID CU C1 IOWA STATE UNIV SCI & TECHNOL,DEPT MAT SCI & ENGN,AMES,IA 50011. RP GREEN, TM (reprint author), IOWA STATE UNIV SCI & TECHNOL,AMES LAB,AMES,IA 50011, USA. NR 14 TC 4 Z9 4 U1 0 U2 0 PU AMER CERAMIC SOC PI WESTERVILLE PA 735 CERAMIC PLACE, PO BOX 6136, WESTERVILLE, OH 43081-6136 SN 0002-7812 J9 AM CERAM SOC BULL JI Am. Ceram. Soc. Bull. PD JUL PY 1991 VL 70 IS 7 BP 1162 EP 1166 PG 5 WC Materials Science, Ceramics SC Materials Science GA FW425 UT WOS:A1991FW42500010 ER PT J AU KUO, WL TENJIN, H SEGRAVES, R PINKEL, D GOLBUS, MS GRAY, J AF KUO, WL TENJIN, H SEGRAVES, R PINKEL, D GOLBUS, MS GRAY, J TI DETECTION OF ANEUPLOIDY INVOLVING CHROMOSOME-13, CHROMOSOME-18, OR CHROMOSOME-21, BY FLUORESCENCE INSITU HYBRIDIZATION (FISH) TO INTERPHASE AND METAPHASE AMNIOCYTES SO AMERICAN JOURNAL OF HUMAN GENETICS LA English DT Article ID AGE-SPECIFIC RATES; DNA LIBRARIES; ABERRATIONS; ABNORMALITIES; SEQUENCES; PROBES; AMNIOCENTESIS; CELLS AB Fluorescence in situ hybridization (FISH) with chromosome-specific proves has been applied to detection of numerical aberrations involving chromosomes 13, 18, and 21 in metaphase and interphase amniocytes. High-complexity, composite probes for chromosomes 13, 18, and 21 were used as hybridization probes for this study. These probes were constructed as chromosome-specific libraries in Bluescribe plasmids and are designated pBS-13, pBS-18, and pBS-21. Elements of these probes bind at numerous sites along the target chromosome and, when detected fluorescently, stain essentially the entire long arm of the target chromosome. The target chromosome number (i.e., the number of chromosomes of the type for which the probe was specific) was correctly determined in 20 of 20 samples in which metaphase spreads were analyzed and in 43 of 43 samples in which interphase nuclei were analyzed; all of these studies were conducted in blind fashion. These results suggest the utility of FISH with composite probes for rapid detection of numerical aberrations in metaphase and interphase amniotic cells. C1 UNIV CALIF LAWRENCE LIVERMORE NATL LAB,DIV BIOMED SCI,LIVERMORE,CA 94550. NIPPON MED COLL,DEPT GYNECOL,TOKYO 113,JAPAN. UNIV CALIF SAN FRANCISCO,DEPT OBSTET GYNECOL & REPROD SCI,SAN FRANCISCO,CA 94143. RI Slagboom, P. Eline/R-4790-2016 OI Slagboom, P. Eline/0000-0002-2875-4723 FU NICHD NIH HHS [HD 17665] NR 26 TC 115 Z9 117 U1 0 U2 0 PU UNIV CHICAGO PRESS PI CHICAGO PA 5720 S WOODLAWN AVE, CHICAGO, IL 60637 SN 0002-9297 J9 AM J HUM GENET JI Am. J. Hum. Genet. PD JUL PY 1991 VL 49 IS 1 BP 112 EP 119 PG 8 WC Genetics & Heredity SC Genetics & Heredity GA FW511 UT WOS:A1991FW51100014 PM 2063863 ER PT J AU FRITZ, JS CHEN, J AF FRITZ, JS CHEN, J TI NEW CHROMATOGRAPHIC METHODS FOR THE DETERMINATION OF WATER SO AMERICAN LABORATORY LA English DT Article AB The effect water has in shifting the spectral absorbance of some organic compounds forms the basis for its quantitative determination chromatographically. A simple HPLC method with a patented spectrophotometric detection system, and a nearly instantaneous reaction with water followed by GC determination of the reaction products, constitute two quick and reliable methods to date. C1 IOWA STATE UNIV SCI & TECHNOL,DEPT CHEM,AMES,IA 50011. RP FRITZ, JS (reprint author), US DOE,AMES LAB,AMES,IA 50011, USA. NR 11 TC 3 Z9 3 U1 0 U2 0 PU INT SCIENTIFIC COMMUN INC PI SHELTON PA PO BOX 870, 30 CONTROLS DRIVE, SHELTON, CT 06484-0870 SN 0044-7749 J9 AM LAB JI Am. Lab. PD JUL PY 1991 VL 23 IS 11 BP J24 EP & PG 0 WC Chemistry, Analytical; Instruments & Instrumentation SC Chemistry; Instruments & Instrumentation GA FV287 UT WOS:A1991FV28700005 ER PT J AU BLOM, PE JOHNSON, JB AF BLOM, PE JOHNSON, JB TI CONCENTRATIONS OF CS-137 AND CO-60 IN NESTS OF THE HARVESTER ANT, POGONOMYRMEX-SALINUS, AND ASSOCIATED SOILS NEAR NUCLEAR-REACTOR WASTE-WATER DISPOSAL PONDS SO AMERICAN MIDLAND NATURALIST LA English DT Article ID OCCIDENTALIS; COLONIES; OWYHEEI; IDAHO AB Waste water from light-water-moderated and cooled nuclear reactors of the Test Reactor Area on the Idaho National Engineering Laboratory was discharged into three ponds to leach into the soil. Soils of Pogonomyrmex salinus nests near these ponds contained concentrations of Cs-137 and Co-60 greater than those observed in adjacent reference soils. The mound contained the highest concentrations of Cs-137 and Co-60 with levels at least two times greater than any other nest-associated or reference soil. The concentrations in the mound may have resulted from aggregation of surface particles and/or through vertical exhumation of deeper soils during nest construction. Considerations from Pogonomyrmex biology and the observation that radionuclide concentrations 5-10 cm below the mound were significantly greater than soils of the same depth not influenced by ants lend strength to the latter hypothesis. No significant erosion of Cs-137 and Co-60 from the mound to the surrounding clearing was detected. C1 US DOE,IDAHO FALLS,ID 83402. RP BLOM, PE (reprint author), UNIV IDAHO,DEPT PLANT SOIL & ENTOMOL SCI,MOSCOW,ID 83843, USA. NR 27 TC 7 Z9 7 U1 0 U2 0 PU AMER MIDLAND NATURALIST PI NOTRE DAME PA UNIV NOTRE DAME, NOTRE DAME, IN 46556 SN 0003-0031 J9 AM MIDL NAT JI Am. Midl. Nat. PD JUL PY 1991 VL 126 IS 1 BP 140 EP 151 DI 10.2307/2426158 PG 12 WC Biodiversity Conservation; Ecology SC Biodiversity & Conservation; Environmental Sciences & Ecology GA GA853 UT WOS:A1991GA85300014 ER PT J AU GOERINGER, DE GLISH, GL MCLUCKEY, SA AF GOERINGER, DE GLISH, GL MCLUCKEY, SA TI FIXED-WAVELENGTH LASER IONIZATION TANDEM MASS-SPECTROMETRY FOR MIXTURE ANALYSIS IN THE QUADRUPOLE ION TRAP SO ANALYTICAL CHEMISTRY LA English DT Article ID MULTI-PHOTON IONIZATION; AROMATIC-MOLECULES; GAS-CHROMATOGRAPHY; BEAM; FRAGMENTATION; SPECTROSCOPY; DESORPTION; BENZENE AB The analytical potential of fixed-wavelength laser photoionization/tandem mass spectrometry in the quadrupole ion trap is investigated. The capability of the ion trap for mass-selective isolation and dissociation of laser-generated ions is exploited for organic mixture analysis. Despite the fact that collision-induced dissociation (CID) yields product ions no different from the fragment ions produced via laser ionization/fragmentation, tandem mass spectrometry is shown to improve the specificity of fixed-wavelength (266-nm), resonance-enhanced, two-photon ionization (R2PI). The technique is illustrated by using mass-selective CID of laser-generated molecular ions from a mixture of ethylbenzene, propylbenzene, and the isomers N,N-dimethylaniline and N-ethylaniline. RP GOERINGER, DE (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 34 TC 8 Z9 8 U1 1 U2 1 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 SN 0003-2700 J9 ANAL CHEM JI Anal. Chem. PD JUL 1 PY 1991 VL 63 IS 13 BP 1186 EP 1192 DI 10.1021/ac00013a002 PG 7 WC Chemistry, Analytical SC Chemistry GA FV113 UT WOS:A1991FV11300004 ER PT J AU BRISBIN, IL AUSTAD, SN AF BRISBIN, IL AUSTAD, SN TI TESTING THE INDIVIDUAL ODOR THEORY OF CANINE OLFACTION SO ANIMAL BEHAVIOUR LA English DT Article C1 HARVARD UNIV,DEPT ORGANISM & EVOLUT BIOL,BIOL LABS,16 DIVIN AVE,CAMBRIDGE,MA 02138. SAVANNAH RIVER ECOL LAB,AIKEN,SC 29801. NR 11 TC 31 Z9 31 U1 2 U2 19 PU ACADEMIC PRESS LTD PI LONDON PA 24-28 OVAL RD, LONDON, ENGLAND NW1 7DX SN 0003-3472 J9 ANIM BEHAV JI Anim. Behav. PD JUL PY 1991 VL 42 BP 63 EP 69 DI 10.1016/S0003-3472(05)80606-2 PN 1 PG 7 WC Behavioral Sciences; Zoology SC Behavioral Sciences; Zoology GA FY405 UT WOS:A1991FY40500007 ER PT J AU SNYDER, JJ REICHERT, P BAER, TM AF SNYDER, JJ REICHERT, P BAER, TM TI FAST DIFFRACTION-LIMITED CYLINDRICAL MICROLENSES SO APPLIED OPTICS LA English DT Article DE MICROLENSES; MICROOPTICS; CYLINDRICAL LENSES; DIFFRACTION-LIMITED LENSES; CYLINDRICAL MICROLENSES; CYLINDRICAL MICROOPTICS; FIBER LENSES; LASER DIODE LENSES; LASER DIODE OPTICS; INTEGRATED OPTICS LENSES AB We describe a technique for fabricating fast well-corrected cylindrical microlenses for applications such as collimating laser diodes and coupling light into and out of integrated optics devices. The lenses are produced by first grinding a glass preform to a desired cross-sectional shape and then heating and drawing the preform into a fiber of the desired diameter. The heating and drawing operations polish the glass surface and reduce the cross-sectional dimensions but maintain the cross-sectional shape. Diffraction-limited 220-mu-m focal length immersion lenses with numerical aperture > 0.6 have been demonstrated. C1 SPECTRA PHYS LASER DIODE SYST,MT VIEW,CA 94043. RP SNYDER, JJ (reprint author), UNIV CALIF LAWRENCE LIVERMORE NATL LAB,POB 808,LIVERMORE,CA 94551, USA. NR 10 TC 51 Z9 52 U1 1 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 JUL 1 PY 1991 VL 30 IS 19 BP 2743 EP 2747 PG 5 WC Optics SC Optics GA FU391 UT WOS:A1991FU39100014 PM 20700270 ER PT J AU HALLER, EE WOLK, JA AF HALLER, EE WOLK, JA TI SI DX CENTERS IN GAAS AT LARGE HYDROSTATIC PRESSURES SO APPLIED PHYSICS A-MATERIALS SCIENCE & PROCESSING LA English DT Article ID DIAMOND ANVIL CELL; ALXGA1-XAS ALLOYS; GALLIUM-ARSENIDE; PHOTOCONDUCTIVITY; SEMICONDUCTORS; CAPTURE; SILICON AB A number of experimental and theoretical studies indicate that DX centers in GaAs, its alloys and other III-V semiconductors have negative U properties. Using far infrared localized vibrational mode (LVM) spectroscopy of Si donors in GaAs under large hydrostatic pressure in a diamond anvil cell we have discovered an LVM of the Si DX center. From the ratio of the LVM absorption lines of Si(Ga) and Si(DX) and the compensation in our GaAs samples, we show unambiguously that two electrons are trapped when the ionized shallow Si donors transform into negatively charged DX centers, in full agreement with the negative U model. C1 UNIV CALIF BERKELEY,BERKELEY,CA 94720. RP HALLER, EE (reprint author), UNIV CALIF BERKELEY LAWRENCE BERKELEY LAB,CTR ADV MAT,BERKELEY,CA 94720, USA. NR 27 TC 2 Z9 2 U1 0 U2 1 PU SPRINGER VERLAG PI NEW YORK PA 175 FIFTH AVE, NEW YORK, NY 10010 SN 0947-8396 J9 APPL PHYS A-MATER JI Appl. Phys. A-Mater. Sci. Process. PD JUL PY 1991 VL 53 IS 1 BP 26 EP 31 DI 10.1007/BF00323430 PG 6 WC Materials Science, Multidisciplinary; Physics, Applied SC Materials Science; Physics GA FV077 UT WOS:A1991FV07700005 ER PT J AU JOU, CJ WASHBURN, J AF JOU, CJ WASHBURN, J TI RELATIONSHIP BETWEEN TC AND ELECTRONEGATIVITY DIFFERENCES IN COMPOUND SUPERCONDUCTORS SO APPLIED PHYSICS A-MATERIALS SCIENCE & PROCESSING LA English DT Article ID HIGH-TEMPERATURE SUPERCONDUCTIVITY; CU-O SYSTEM; CRYSTAL-STRUCTURE; BULK SUPERCONDUCTIVITY; OXIDE SUPERCONDUCTORS; OXYGEN ISOTOPE; 2 DIMENSIONS; COPPER; BIPOLARONS; MODEL AB The electronegativity differences, DELTA-N, between the anions and the cations in suggested resonating elements of some representative high-temperature superconductors with T(c) greater-than-or-equal-to 10 K are evaluated adopting Pauling's scale. The relationship between DELTA-N and T(c) was found to separate all the examined high-T(c) superconductors onto two curves: One for the cuprate superconductors having two-dimensional layered structures was a straight line, T(c) = 29.8 + 4.1 DELTA-N; the other correlation curve representing the remaining compound superconductors including the doped 113 perovskite and the perovskite-related 214 structures was at lower T(c) values but also suggested that increasing electronegativity difference was related to increasing T(c). C1 UNIV CALIF BERKELEY,DEPT MAT SCI & MINERAL ENGN,BERKELEY,CA 94720. RP JOU, CJ (reprint author), UNIV CALIF BERKELEY LAWRENCE BERKELEY LAB,CTR ADV MAT,DIV MAT & CHEM SCI,BERKELEY,CA 94720, USA. NR 77 TC 3 Z9 3 U1 1 U2 6 PU SPRINGER VERLAG PI NEW YORK PA 175 FIFTH AVE, NEW YORK, NY 10010 SN 0947-8396 J9 APPL PHYS A-MATER JI Appl. Phys. A-Mater. Sci. Process. PD JUL PY 1991 VL 53 IS 1 BP 87 EP 93 DI 10.1007/BF00323440 PG 7 WC Materials Science, Multidisciplinary; Physics, Applied SC Materials Science; Physics GA FV077 UT WOS:A1991FV07700015 ER PT J AU FERRARO, JR HILL, S STOUT, P FURLANI, A POLZONETTI, G RUSSO, MV AF FERRARO, JR HILL, S STOUT, P FURLANI, A POLZONETTI, G RUSSO, MV TI COMPARISON OF HETEROGENEOUSLY AND HOMOGENEOUSLY DOPED POLYPHENYLACETYLENE USING IR AND XPS SO APPLIED SPECTROSCOPY LA English DT Article DE CONDUCTIVE POLYMER FILMS; XPS; IR(ATR); RAMAN ID CONDUCTING POLYMERS; POLYACETYLENE; SPECTROSCOPY; SPECTRA; (CH)X AB Infrared (IR) and x-ray photoemission spectroscopy (XPS) studies have been made on heterogeneously iodine-doped polyphenylacetylene (PPA) polymer films. Similarities and differences between the doping processes (heterogeneous and homogeneous) are presented. Results point to a surface doping process in the heterogeneously doped films vs. a bulk process in the homogeneously doped materials (doped in solution). The counter anion moiety in the films appears to be the polyiodide I5- ion, as contrasted to the bulk powder (homogeneously doped) polymer in which the species of I2, I3- in the presence of a predominance of I5- ion coexist. C1 BIORAD,DIV DIGILAB,CAMBRIDGE,MA 02139. UNIV LA SAPIENZA,DEPT CHEM,I-00185 ROME,ITALY. RP FERRARO, JR (reprint author), ARGONNE NATL LAB,DIV CHEM,9700 CASS AVE,ARGONNE,IL 60439, USA. NR 23 TC 6 Z9 6 U1 1 U2 1 PU SOC APPLIED SPECTROSCOPY PI FREDERICK PA PO BOX 1438, FREDERICK, MD 21701 SN 0003-7028 J9 APPL SPECTROSC JI Appl. Spectrosc. PD JUL PY 1991 VL 45 IS 6 BP 932 EP 937 DI 10.1366/0003702914336192 PG 6 WC Instruments & Instrumentation; Spectroscopy SC Instruments & Instrumentation; Spectroscopy GA FY841 UT WOS:A1991FY84100003 ER PT J AU ARMSTRONG, DP BOSTICK, WD FLETCHER, WH AF ARMSTRONG, DP BOSTICK, WD FLETCHER, WH TI AN FT-IR STUDY OF THE ATMOSPHERIC HYDROLYSIS OF URANIUM HEXAFLUORIDE SO APPLIED SPECTROSCOPY LA English DT Article DE URANIUM HEXAFLUORIDE; URANYL FLUORIDE; HYDROGEN FLUORIDE; UF6 RELEASE; UF6 HYDROLYSIS AB The handling and processing of UF6 is accompanied by the potential for a reaction with water, usually as airborne moisture, and the subsequent risk of releasing airborne, particulate UO2F2 and gaseous hydrogen fluoride. We have studied this reaction under the simulated conditions of a "release" of UF6, whereby hot, pressurized UF6 gas suddenly escapes into ambient air. The "release" experiment simulates, on a small scale, the accidental mixing of UF6 gas with the atmosphere in the absence of wind currents. The data obtained with the use of FT-IR spectroscopy have provided information which permits a much better understanding of the behavior of the evolved hydrogen fluoride, the residual water vapor, and the airborne, particulate UO2F2 and of their relation to each other. C1 OAK RIDGE K-25 SITE,DIV TECH,OAK RIDGE,TN 37831. UNIV TENNESSEE,DEPT CHEM,KNOXVILLE,TN 37996. RP ARMSTRONG, DP (reprint author), URANIUM ENRICHMENT ORG,APPL URANIUM CHEM & SPECT GRP,BOX 2003,OAK RIDGE,TN 37831, USA. NR 10 TC 8 Z9 9 U1 3 U2 6 PU SOC APPLIED SPECTROSCOPY PI FREDERICK PA PO BOX 1438, FREDERICK, MD 21701 SN 0003-7028 J9 APPL SPECTROSC JI Appl. Spectrosc. PD JUL PY 1991 VL 45 IS 6 BP 1008 EP 1016 DI 10.1366/0003702914336381 PG 9 WC Instruments & Instrumentation; Spectroscopy SC Instruments & Instrumentation; Spectroscopy GA FY841 UT WOS:A1991FY84100015 ER PT J AU DAI, S YOUNG, JP MAMANTOV, G AF DAI, S YOUNG, JP MAMANTOV, G TI A NEW SAMPLE CELL FOR DIFFUSE REFLECTANCE IR SPECTROSCOPY OF AIR-SENSITIVE SOLID SAMPLES SO APPLIED SPECTROSCOPY LA English DT Note DE INFRARED; AIR-SENSITIVE SAMPLES; REFLECTANCE; SPECTROSCOPY TECHNIQUES C1 OAK RIDGE NATL LAB,DIV ANALYT CHEM,OAK RIDGE,TN 37831. UNIV TENNESSEE,DEPT CHEM,KNOXVILLE,TN 37996. RI Dai, Sheng/K-8411-2015 OI Dai, Sheng/0000-0002-8046-3931 NR 7 TC 7 Z9 7 U1 1 U2 7 PU SOC APPLIED SPECTROSCOPY PI FREDERICK PA PO BOX 1438, FREDERICK, MD 21701 SN 0003-7028 J9 APPL SPECTROSC JI Appl. Spectrosc. PD JUL PY 1991 VL 45 IS 6 BP 1056 EP 1058 DI 10.1366/0003702914336327 PG 3 WC Instruments & Instrumentation; Spectroscopy SC Instruments & Instrumentation; Spectroscopy GA FY841 UT WOS:A1991FY84100027 ER PT J AU KUREK, E FRANCIS, AJ BOLLAG, JM AF KUREK, E FRANCIS, AJ BOLLAG, JM TI IMMOBILIZATION OF CADMIUM BY MICROBIAL EXTRACELLULAR PRODUCTS SO ARCHIVES OF ENVIRONMENTAL CONTAMINATION AND TOXICOLOGY LA English DT Article ID PSEUDOMONAS-PUTIDA; ESCHERICHIA-COLI; HEAVY-METALS; SEWAGE-SLUDGE; SORPTION; SOIL; ACCOMMODATION; DISSOLUTION; MOBILITY; MOVEMENT AB An axenic bacterial culture was isolated from Morrison loam soil (pH 6.4) and was capable of growth in the presence of CdO (175-mu-g/mL of Cd). During the first two days of incubation, growth of the culture was accompanied by a decrease in the concentration of soluble Cd. This effect was due to two phenomena: (1) a decrease in the solubility of CdO in medium conditioned by the microorganisms; and (2) to sorption of Cd to bacterial cells. The solubility of CdO in filter-sterilized spend medium was very low (4-6-mu-g/mL), yet the solubility was high (110-160-mu-g/mL) in autoclaved, filtered spent medium. Changes in the pH value of the medium were not responsible for this effect. Incubation of spent medium in the presence of increasing concentrations of Cd as Cd(NO3)2 resulted in a decrease in the metal concentration of the liquid, due to the formation of a precipitate in quantities proportional to the amount of added Cd. Similar precipitate formation was observed when 100-mu-g/mL of Hg, Cu, or Zn were added but not when 100-mu-g/mL of Mg was introduced. The compound(s) responsible for the precipitate formation was not dialyzable from tubing with a pore size of 12,000-14,000 and was not retained by a C18 Sep-Pak cartridge. Dialysis of a suspension of the precipitate against water (pH 3.0) resulted in partial dissolution of the complex. Approximately 50% of the bound Cd was released and this was accompanied by the release of a protein of molecular weight of 42,600 daltons. The results suggest that this microbial protein forms a water insoluble precipitate with Cd and therefore plays a major role in decreasing the concentration of soluble Cd during microbial growth. C1 PENN STATE UNIV,SOIL BIOCHEM LAB,UNIVERSITY PK,PA 16802. BROOKHAVEN NATL LAB,DEPT APPL SCI,UPTON,NY 11973. NR 28 TC 5 Z9 5 U1 0 U2 0 PU SPRINGER VERLAG PI NEW YORK PA 175 FIFTH AVE, NEW YORK, NY 10010 SN 0090-4341 J9 ARCH ENVIRON CON TOX JI Arch. Environ. Contam. Toxicol. PD JUL PY 1991 VL 21 IS 1 BP 106 EP 111 PG 6 WC Environmental Sciences; Toxicology SC Environmental Sciences & Ecology; Toxicology GA FR206 UT WOS:A1991FR20600015 ER PT J AU FINGER, PT MOSHFEGHI, DM SMITH, PD PERRY, HD AF FINGER, PT MOSHFEGHI, DM SMITH, PD PERRY, HD TI MICROWAVE CYCLODESTRUCTION FOR GLAUCOMA IN A RABBIT MODEL SO ARCHIVES OF OPHTHALMOLOGY LA English DT Article ID THERAPEUTIC ULTRASOUND; TRANSSCLERAL NEODYMIUM; HYPERTHERMIC TREATMENT; INTRAOCULAR TUMORS; YAG LASER; THERMORADIOTHERAPY; CYCLOCRYOTHERAPY AB Microwave thermotherapy was used to treat experimentally induced glaucoma. Microwave-induced cyclodestruction was successful in reducing intraocular pressure in all treated glaucomatous eyes for 4 weeks. Two additional glaucomatous eyes were left untreated to serve as controls, and were noted to have persistently elevated intraocular pressures. Six additional eyes were then subjected to an equivalent treatment (50-degrees-C in five 1-minute applications), which resulted in approximately 180-degrees of heat treatment just posterior to the corneoscleral limbus. These specimens were evaluated with light microscopy at baseline, 24 hours, and 7 days after treatment. Our clinical and histopathologic evaluations suggested that microwave thermotherapy (delivered under thermometry control) allowed for chorioretinal/ciliary body destruction that resulted in reductions of intraocular pressure in glaucomatous eyes. C1 CORNELL UNIV,N SHORE UNIV HOSP,COLL MED,DEPT OPHTHALMOL,MANHASSET,NY 11030. TULANE UNIV,DEPT BIOMED ENGN,NEW ORLEANS,LA 70118. BROOKHAVEN NATL LAB,DEPT MED,UPTON,NY 11973. CORNELL UNIV,MED CTR,COLL MED,DEPT OPHTHALMOL,NEW YORK,NY 10021. OI Finger, Paul T/0000-0002-8111-3896 NR 27 TC 5 Z9 5 U1 0 U2 0 PU AMER MEDICAL ASSOC PI CHICAGO PA 515 N STATE ST, CHICAGO, IL 60610 SN 0003-9950 J9 ARCH OPHTHALMOL-CHIC JI Arch. Ophthalmol. PD JUL PY 1991 VL 109 IS 7 BP 1001 EP 1004 PG 4 WC Ophthalmology SC Ophthalmology GA FV414 UT WOS:A1991FV41400036 PM 2064553 ER PT J AU MONAGHAN, JJ LATTANZIO, JC AF MONAGHAN, JJ LATTANZIO, JC TI A SIMULATION OF THE COLLAPSE AND FRAGMENTATION OF COOLING MOLECULAR CLOUDS SO ASTROPHYSICAL JOURNAL LA English DT Article DE HYDRODYNAMICS; INTERSTELLAR, MOLECULES; NEBULAE, INDIVIDUAL (W49); NEBULAE, STRUCTURE ID ISOTHERMAL CLOUDS; STAR FORMATION; GAS CLOUDS; SHOCKS; SPH AB We describe the application of the Smoothed Particle Hydrodynamics method to the fragmentation of rotating cloud and disk systems, allowing for molecular cooling due to H-2 and CO. We also describe a novel approach to solving Poisson's equation for disklike structures, which exploits the multigrid algorithm. Numerical studies are presented which investigate the evolution of both rotating clouds and Maclaurin disks, in each case with both an isothermal equation of state and with molecular cooling. Our results establish the influence of molecular cooling on the fragmentation of molecular clouds. The isothermal sequences, if they fragment at all, do so into far fewer lumps than the cooling sequences. This is not due to a cooling instability as such, but rather to the reduced thermal support. One of our sequences shows a remarkable similarity to the W49A star-forming region. C1 UNIV CALIF BERKELEY,DEPT ASTRON,BERKELEY,CA 94720. UNIV CALIF LAWRENCE LIVERMORE NATL LAB,INST GEOPHYS & PLANETARY PHYS,LIVERMORE,CA 94550. RP MONAGHAN, JJ (reprint author), MONASH UNIV,DEPT MATH,CLAYTON,VIC 3168,AUSTRALIA. NR 27 TC 75 Z9 76 U1 1 U2 6 PU UNIV CHICAGO PRESS PI CHICAGO PA 5720 S WOODLAWN AVE, CHICAGO, IL 60637 SN 0004-637X J9 ASTROPHYS J JI Astrophys. J. PD JUL 1 PY 1991 VL 375 IS 1 BP 177 EP 189 DI 10.1086/170179 PN 1 PG 13 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA FT836 UT WOS:A1991FT83600016 ER PT J AU WINTER, R CHRISTMANN, MH BOTTNER, M THIYAGARAJAN, P HEENAN, RK AF WINTER, R CHRISTMANN, MH BOTTNER, M THIYAGARAJAN, P HEENAN, RK TI THE INFLUENCE OF THE LOCAL-ANESTHETIC TETRACAINE ON THE TEMPERATURE AND PRESSURE DEPENDENT PHASE-BEHAVIOR OF MODEL BIOMEMBRANES SO BERICHTE DER BUNSEN-GESELLSCHAFT-PHYSICAL CHEMISTRY CHEMICAL PHYSICS LA English DT Article DE BIOPHYSICAL CHEMISTRY; HIGH PRESSURE; MEMBRANES; NEUTRON SCATTERING; PHASE TRANSITIONS ID ANGLE NEUTRON-SCATTERING; NUCLEAR MAGNETIC-RESONANCE; DIPALMITOYL PHOSPHATIDYLCHOLINE; HYDROSTATIC-PRESSURE; GENERAL-ANESTHETICS; TRANSITION TEMPERATURE; BIOLOGICAL-MEMBRANES; CELL-MEMBRANE; X-RAY; MOLECULAR-ORGANIZATION AB By using differential scanning calorimetry and neutron small-angle scattering, the effect of the local anaesthetic tetracaine on the temperature and pressure dependent phase behaviour of model biomembrane systems, such as pure and cholesterol - containing 1,2-dimyristoyl-phosphatidylcholine bilayers, has been investigated. The results provide insight into the thermodynamic and structural consequences of the incorporation of the anaesthetic into the membranes and might thus help in understanding the molecular mechanisms underlying the pharmacological action of local anaesthetics and the antagonistic effect of pressure against anaesthesia, which has been observed in vivo. Furthermore, as tetracaine can be viewed as a model system for amphiphilic molecules, knowledge of its concentration, temperature and pressure dependent phase behaviour helps in understanding the general physico-chemical action of amphiphilic molecules on membranes. C1 ARGONNE NATL LAB,DIV INTENSE PULSED NEUTRON SOURCE,ARGONNE,IL 60439. RUTHERFORD APPLETON LAB,DIDCOT OX11 0QX,OXON,ENGLAND. RP WINTER, R (reprint author), UNIV MARBURG,INST PHYS CHEM,HANS MEERWEINSTR,W-3550 MARBURG,GERMANY. NR 82 TC 17 Z9 17 U1 0 U2 1 PU VCH PUBLISHERS INC PI DEERFIELD BEACH PA 303 NW 12TH AVE, DEERFIELD BEACH, FL 33442-1788 SN 0005-9021 J9 BER BUNSEN PHYS CHEM JI Ber. Bunsen-Ges. Phys. Chem. Chem. Phys. PD JUL PY 1991 VL 95 IS 7 BP 811 EP 820 PG 10 WC Chemistry, Physical SC Chemistry GA GB585 UT WOS:A1991GB58500009 ER PT J AU FREI, B FORTE, TM AMES, BN CROSS, CE AF FREI, B FORTE, TM AMES, BN CROSS, CE TI GAS-PHASE OXIDANTS OF CIGARETTE-SMOKE INDUCE LIPID-PEROXIDATION AND CHANGES IN LIPOPROTEIN PROPERTIES IN HUMAN BLOOD-PLASMA - PROTECTIVE EFFECTS OF ASCORBIC-ACID SO BIOCHEMICAL JOURNAL LA English DT Article ID LOW-DENSITY-LIPOPROTEIN; VITAMIN-C; OXIDATIVE MODIFICATION; CHOLESTEROL; MACROPHAGES; METABOLISM; ACCUMULATION; NEUTROPHILS; ANTIOXIDANT; SUBCLASSES AB Cigarette smoke (CS) is known to contain a large number of oxidants. In order to assess the oxidative effects of CS on biological fluids, we exposed human blood plasma to filtered (gas phase) and unfiltered (whole) CS, and determined the rate of utilization of endogenous antioxidants in relation to the appearance of lipid hydroperoxides. Lipid peroxidation was measured with a specific and sensitive assay that can detect lipid hydroperoxides at plasma levels as low as 10 nM. We found that exposure of plasma to the gas phase of CS, but not to whole CS, induces lipid peroxidation once endogenous ascorbic acid has been oxidized completely. In addition, CS exposure caused oxidation of plasma protein thiols and albumin-bound bilirubin, whereas uric acid and alpha-tocopherol were not consumed at significant rates. In plasma exposed to the gas phase of CS, low-density lipoprotein exhibited slightly increased electrophoretic mobility, but there was no apparent degradation of apolipoprotein B. Our results support the concept of an increased vitamin C utilization in smokers, and suggest that lipid peroxidation induced by oxidants present in the gas phase of CS leads to potentially atherogenic changes in lipoproteins. C1 UNIV CALIF BERKELEY, DIV BIOCHEM & MOLEC BIOL, BERKELEY, CA 94720 USA. UNIV CALIF BERKELEY LAWRENCE BERKELEY LAB, BERKELEY, CA 94720 USA. UNIV CALIF DAVIS, DEPT MED & PHYSIOL, DAVIS, CA 95616 USA. FU NCI NIH HHS [CA39910]; NHLBI NIH HHS [HL18574]; NIEHS NIH HHS [ES01896] NR 48 TC 374 Z9 382 U1 1 U2 5 PU PORTLAND PRESS LTD PI LONDON PA CHARLES DARWIN HOUSE, 12 ROGER STREET, LONDON WC1N 2JU, ENGLAND SN 0264-6021 EI 1470-8728 J9 BIOCHEM J JI Biochem. J. PD JUL 1 PY 1991 VL 277 BP 133 EP 138 PN 1 PG 6 WC Biochemistry & Molecular Biology SC Biochemistry & Molecular Biology GA FV584 UT WOS:A1991FV58400019 PM 1854329 ER PT J AU TUMMINIA, SJ MANDIYAN, V WALL, JS BOUBLIK, M AF TUMMINIA, SJ MANDIYAN, V WALL, JS BOUBLIK, M TI HETEROGENEITY OF ESCHERICHIA-COLI RIBOSOMES ESTABLISHED BY SCANNING-TRANSMISSION ELECTRON-MICROSCOPY SO BIOCHIMIE LA English DT Article DE ELECTRON MICROSCOPY; RIBOSOMES; ESCHERICHIA-COLI; MORPHOLOGY; MOLECULAR MASS; RADIUS OF GYRATION AB Quantitative mass image analysis of Escherichia coli ribosomal particles by scanning transmission electron microscopy (STEM) provided direct evidence that presumably homogeneous preparations of ribosomes are, in reality, populations of heterogeneous particles. Variations in composition, relative molecular mass (M(r)) and shape were observed both in the monosomes and in the ribosomal subunits. None of these changes can be resolved visually; they can be evaluated only by computer processing. The variations in relative mass and shape monitored by values of radius of gyration (R(G)) were attributed to the loss of ribosomal proteins and/or factors and correlated with the changes in ribosome composition and biological activity. The highest activity was found in monosomes prepared from the standard 0.5 M NH4Cl wash. With increasing concentrations (up to 1.5 M) of NH4Cl in the wash buffer the activity decreased slowly, then dropped rapidly to about half in 2 M NH4Cl. The most striking effects were observed in ribosomal particles washed with 0.1 M NH4Cl. The 70S monosomes and the 30S subunits attained maximum M(r) and R(G) values (2660 kDa and 76 angstrom, and 990 kDa and 75 angstrom, respectively), which were greater than the theoretical values, while the activity was minimal (almost-equal-to 12%). The M(r) and R(G) parameters of the 50S subunits remained uneffected by the NH4Cl washes (almost-equal-to 1600 kDa and 68 angstrom). C1 ROCHE INST MOLEC BIOL,ROCHE RES CTR,NUTLEY,NJ 07110. BROOKHAVEN NATL LAB,DEPT BIOL,UPTON,NY 11973. FU NCRR NIH HHS [RRO 1777] NR 12 TC 8 Z9 8 U1 1 U2 1 PU EDITIONS SCIENTIFIQUES ELSEVIER PI PARIS CEDEX 15 PA 141 RUE JAVEL, 75747 PARIS CEDEX 15, FRANCE SN 0300-9084 J9 BIOCHIMIE JI Biochimie PD JUL-AUG PY 1991 VL 73 IS 7-8 BP 919 EP 925 DI 10.1016/0300-9084(91)90133-L PG 7 WC Biochemistry & Molecular Biology SC Biochemistry & Molecular Biology GA GF348 UT WOS:A1991GF34800008 PM 1742364 ER PT J AU GOLDBECK, RA DAWES, TD EINARSDOTTIR, O WOODRUFF, WH KLIGER, DS AF GOLDBECK, RA DAWES, TD EINARSDOTTIR, O WOODRUFF, WH KLIGER, DS TI TIME-RESOLVED MAGNETIC CIRCULAR-DICHROISM SPECTROSCOPY OF PHOTOLYZED CARBONMONOXY CYTOCHROME-C-OXIDASE (CYTOCHROME-AA3) SO BIOPHYSICAL JOURNAL LA English DT Article ID INFRARED-SPECTROSCOPY; HEMOGLOBIN; BINDING; HEME; ABSORPTION; DYNAMICS; RAMAN AB Nanosecond time-resolved magnetic circular dichroism (TRMCD) and time-resolved natural circular dichroism (TRCD) measurements of photolysis products of the CO complex of eukaryotic cytochrome c oxidase (CcO-CO) are presented. TRMCD spectra obtained at 100 ns and 10-mu-s after photolysis are diagnostic of pentacoordinate cytochrome a3 Fe2+, as would be expected for simple photodissociation. Other time-resolved spectroscopies (UV-visible and resonance Raman), however, show evidence for unusual Fe(a3)2+ coordination after CO photolysis (Woodruff, W. H., O. Einarsdottir, R. B. Dyer, K. A. Bagley, G. Palmer, S. J. Atherton, R. A. Goldbeck, T. D. Dawes, and D. S. Kliger. 1991. Proc. Nat. Acad. Sci, U.S.A. 88:2588-2592). Furthermore, time-resolved IR experiments have shown that photodissociated CO binds to Cu(b)+ prior to recombining with Fe(a3)2+ (Dyer, R. B., O. Einarsdottir, P. M. Killough, J. J. Lopez-Garriga, and W. H. Woodruff. 1989. J. Am. Chem. Soc. 111:7657-7659). A model of the CcO-CO photolysis cycle which is consistent with all of the spectroscopic results is presented. A novel feature of this model is the coordination of a ligand endogenous to the protein to the Fe axial site vacated by the photolyzed CO and the simultaneous breaking of the Fe-imidazole(histidine) bond. C1 UNIV CALIF LOS ALAMOS SCI LAB,ISOTOPE & STRUCT CHEM GRP INC 4,LOS ALAMOS,NM 87545. RP GOLDBECK, RA (reprint author), UNIV CALIF SANTA CRUZ,DEPT CHEM & BIOCHEM,SANTA CRUZ,CA 95064, USA. FU NIDDK NIH HHS [DK-36263]; NIGMS NIH HHS [GM-38549] NR 26 TC 21 Z9 21 U1 0 U2 7 PU BIOPHYSICAL SOCIETY PI BETHESDA PA 9650 ROCKVILLE PIKE, BETHESDA, MD 20814-3998 SN 0006-3495 J9 BIOPHYS J JI Biophys. J. PD JUL PY 1991 VL 60 IS 1 BP 125 EP 134 PG 10 WC Biophysics SC Biophysics GA FU407 UT WOS:A1991FU40700012 PM 1653049 ER PT J AU SHIANG, M LINDEN, JC MOHAGHEGHI, A GROHMANN, K HIMMEL, ME AF SHIANG, M LINDEN, JC MOHAGHEGHI, A GROHMANN, K HIMMEL, ME TI REGULATION OF CELLULASE SYNTHESIS IN ACIDOTHERMUS-CELLULOLYTICUS SO BIOTECHNOLOGY PROGRESS LA English DT Article ID TRICHODERMA-REESEI; L-SORBOSE; THERMOMONOSPORA-CURVATA; CATABOLITE REPRESSION; NEUROSPORA-CRASSA; INDUCTION; BIOSYNTHESIS; MUTANTS; PSEUDOKONINGII; CELLULOMONAS AB The regulation of cellulase synthesis by induction and catabolite repression in the thermophilic, aerobic bacterium Acidothermus cellulolyticus was studied in batch fermentations. Various compounds, such as L-sorbose, cyclic AMP (cAMP), L-glucose, 2-deoxyglucose (2-DG), glucose 1-phosphate (G-1-P), sophorose, salicin, sugar alcohols, and isopropyl thioglucoside (IPTGlu), were added along with Solka Floc to improve extracellular cellulase formation by the culture. When cAMP was added exogenously to A. cellulolyticus cultures in the concentration range of 0.01-0.2 g/L, cAMP did not affect cell growth; however, cellulase yields were increased with increasing levels of cAMP. The enzyme production rates with the different levels of cAMP addition during Solka-Floc fermentations were identical. L-Sorbose, L-glucose, 2-DG, G-1-P, sophorose, IPTGlu, and sugar alcohols enhanced cellulase activity produced in the medium, but the starting time and the time required to reach the maximum enzyme activity were different in each condition. All these substances may function as moderators of cellulase synthesis. From the experimental results, only cellobiose, xylose, sophorose, and unknown soluble derivatives from cellulose were considered as inducers. In a possible regulatory mechanism of cellulase synthesis, the repressor, inducer, cAMP, and moderator may be all involved in controlling the rate and the yield of enzyme production. C1 SOLAR ENERGY RES INST,SOLAR FUELS RES,BIOTECHNOL RES BRANCH,APPL BIOL SCI SECT,GOLDEN,CO 80401. COLORADO STATE UNIV,DEPT MICROBIOL,FT COLLINS,CO 80523. COLORADO STATE UNIV,DEPT AGR & CHEM ENGN,FT COLLINS,CO 80523. NR 46 TC 10 Z9 11 U1 0 U2 4 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 SN 8756-7938 J9 BIOTECHNOL PROGR JI Biotechnol. Prog. PD JUL-AUG PY 1991 VL 7 IS 4 BP 315 EP 322 DI 10.1021/bp00010a005 PG 8 WC Biotechnology & Applied Microbiology; Food Science & Technology SC Biotechnology & Applied Microbiology; Food Science & Technology GA GA792 UT WOS:A1991GA79200005 ER PT J AU SORBJAN, Z COULTER, RL WESLEY, ML AF SORBJAN, Z COULTER, RL WESLEY, ML TI SIMILARITY SCALING APPLIED TO SODAR OBSERVATIONS OF THE CONVECTIVE BOUNDARY-LAYER ABOVE AN IRREGULAR HILL SO BOUNDARY-LAYER METEOROLOGY LA English DT Article ID BOTTOM-UP DIFFUSION; TURBULENCE STRUCTURE; STRUCTURE PARAMETER; REFRACTIVE-INDEX; TOP-DOWN; TEMPERATURE; MODEL; MOMENTS; HEIGHT; SCALES AB Nine profiles of the temperature structure parameter C(T)2 and the standard deviation of vertical velocity fluctuations (sigma-w) in the convective boundary layer (CBL) were obtained with a monostatic Doppler sodar during the second intensive field compaign of the First ISLSCP Field Experiment in 1987. The results were analyzed by using local similarity theory. Local similarity curves depend on four parameters: the height of the mixed layer (z(i)), the depth of the interfacial layer (DELTA), and the temperature fluxes at the top of the mixed layer (Q(i)) and the surface (Q(o)). Values of these parameters were inferred from sodar data by using the similarity curve for C(T)2 and observations at three points in its profile. The effects of entrainment processes on the profiles of C(T)2 and sigma-w near the top of the CBL appeared to be described well by local similarity theory. Inferred estimates of surface temperature flux, however, were underestimated in comparison to fluxes measured by eddy correlation. The measured values of sigma-w appeared to be slightly smaller than estimates based on available parmeterizations. These discrepancies might have been caused by experimental error or, more likely, by the distortion of turbulence structure above the site by flow over the nonuniform terrain at the observation site. C1 ARGONNE NATL LAB,DIV ENVIRONM RES,ARGONNE,IL 60439. RP SORBJAN, Z (reprint author), UNIV OKLAHOMA,CIMMS,NORMAN,OK 73019, USA. NR 32 TC 9 Z9 9 U1 0 U2 0 PU KLUWER ACADEMIC PUBL PI DORDRECHT PA SPUIBOULEVARD 50, PO BOX 17, 3300 AA DORDRECHT, NETHERLANDS SN 0006-8314 J9 BOUND-LAY METEOROL JI Bound.-Layer Meteor. PD JUL PY 1991 VL 56 IS 1-2 BP 33 EP 50 DI 10.1007/BF00119961 PG 18 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA FZ885 UT WOS:A1991FZ88500002 ER PT J AU ZHONG, SY LEONE, JM TAKLE, ES AF ZHONG, SY LEONE, JM TAKLE, ES TI INTERACTION OF THE SEA BREEZE WITH A RIVER BREEZE IN AN AREA OF COMPLEX COASTAL HEATING SO BOUNDARY-LAYER METEOROLOGY LA English DT Article ID BOUNDARY-LAYER; MODEL AB A three-dimensional finite-element mesoscale model is used to study the interaction of two different but related mesoscale phenomena in an area having a complex pattern of surface heating. The model simulations have been compared with temperature and wind fields observed on a typical fall day during the Kennedy Space Center Atmospheric Boundary Layer Experiment on the east coast of Florida. Numerical results and observations both show that the meso-beta scale flow field is significantly modified from the conventional coastal-flow patterns by the smaller meso-gamma scale irregular geographic features in this area. A local river breeze is observed to develop around the Indian River almost the same time as the Atlantic sea breeze. A comparison of the sea and the river breezes shows a large difference in their horizontal circulations but only slight differences in their vertical scales. The sea breeze intensifies more rapidly than the river breeze, so that a lag of 1 to 1.5 h exists between their most developed stages. The river breeze is relatively stationary, whereas the sea breeze propagates inland, with an eventual merger of the two circulations occurring about 6-8 h after their onset. Different synoptic wind regimes create different flow structures. Well-defined sea- and river-breeze circulations become established under calm, weak offshore, and weak alongshore synoptic-wind conditions. Maximum vertical velocities occur in the sea-breeze front (river-breeze front) in the cases of calm (offshore winds). The sea breeze and the river breeze are weaker when the synoptic winds are stronger. Finally, the results from numerical experiments designed to isolate the rivers' effect indicate that the convergence in the sea-breeze front is suppressed when it passes over the cooler surface of the rivers. C1 UNIV CALIF LAWRENCE LIVERMORE NATL LAB,LIVERMORE,CA 94550. RP ZHONG, SY (reprint author), IOWA STATE UNIV SCI & TECHNOL,DEPT GEOL & ATMOSPHER SCI,AMES,IA 50011, USA. NR 23 TC 15 Z9 15 U1 0 U2 1 PU KLUWER ACADEMIC PUBL PI DORDRECHT PA SPUIBOULEVARD 50, PO BOX 17, 3300 AA DORDRECHT, NETHERLANDS SN 0006-8314 J9 BOUND-LAY METEOROL JI Bound.-Layer Meteor. PD JUL PY 1991 VL 56 IS 1-2 BP 101 EP 139 DI 10.1007/BF00119964 PG 39 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA FZ885 UT WOS:A1991FZ88500005 ER PT J AU DANIELS, RC BIRDWELL, KR AF DANIELS, RC BIRDWELL, KR TI A STORM CLIMATOLOGY DATABASE WITH APPLICATIONS IN REGIONAL AND GLOBAL CHANGE STUDIES SO BULLETIN OF THE AMERICAN METEOROLOGICAL SOCIETY LA English DT Letter AB Described herein are the contents of a new digital climatological database entitled A Global Geographic Information System Database of Storm Occurrences and Other Climatic Phenomena Affecting Coastal Zones. The database may be used by raster or vector geographic information systems (GIS). The primary focus of the database is the quantification of synoptic storms and other climatological factors that effect coastlines (e.g., induce erosion or contribute to coastal inundation). Data on tropical storms, hurricanes, extratropical cyclones, polar lows, and cyclonicity frequencies as well as information on sea ice concentrations and a monsoon wind index are provided. Portions of the database form complete regional and global coverages, and all of the data groups except one are referenced to 1-degrees by 1-degrees or 5-degrees by 5-degrees grid cells of latitude and longitude. RP DANIELS, RC (reprint author), OAK RIDGE NATL LAB,DIV ENVIRONM SCI,OAK RIDGE,TN, USA. NR 3 TC 1 Z9 1 U1 1 U2 2 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 JUL PY 1991 VL 72 IS 7 BP 1005 EP 1007 PG 3 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA GL655 UT WOS:A1991GL65500006 ER PT J AU ELLSAESSER, HW AF ELLSAESSER, HW TI THE GLOBAL WARMING DEBATE HEATS UP - AN ANALYSIS AND PERSPECTIVE - COMMENT SO BULLETIN OF THE AMERICAN METEOROLOGICAL SOCIETY LA English DT Letter RP ELLSAESSER, HW (reprint author), UNIV CALIF LAWRENCE LIVERMORE NATL LAB,DIV ATMOSPHER & GEOPHYS SCI,POB 808,L-264,LIVERMORE,CA 94550, USA. NR 5 TC 2 Z9 2 U1 1 U2 1 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 JUL PY 1991 VL 72 IS 7 BP 1009 EP 1009 PG 1 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA GL655 UT WOS:A1991GL65500007 ER PT J AU ANDERSEN, CP MCLAUGHLIN, SB ROY, WK AF ANDERSEN, CP MCLAUGHLIN, SB ROY, WK TI FOLIAR INJURY SYMPTOMS AND PIGMENT CONCENTRATIONS IN RED SPRUCE SAPLINGS IN THE SOUTHERN APPALACHIANS SO CANADIAN JOURNAL OF FOREST RESEARCH-REVUE CANADIENNE DE RECHERCHE FORESTIERE LA English DT Note ID NORTH-AMERICA; DECLINE; OZONE AB The frequency and percent surface area covered by necrotic flecking on red spruce (Picea rubens Sarg.) needles from sapling-sized trees were examined on nine research sites on three mountains in the southern Appalachians. Foliar pigment analysis was conducted on trees from two of the nine research sites. Flecking increased with foliar age on all sites, and on two of the mountains the area covered by flecks increased with elevation. Above 1720 m on Clingman's Dome, foliar flecking was found to constitute >8% of the upper needle surface area of 1-year-old needles. Chlorophyll a and b concentrations increased with foliar age and were greater in trees growing at the mid-elevation site (1720 m) than at the high-elevation site (1935 m) on Clingman's Dome. Pigment concentrations did not correspond to foliar flecking frequency at these two sites. Foliar flecking appears to increase over winter, and its widespread occurrence throughout the southern Appalachians suggests that regional rather than local site-related phenomena are involved. C1 OAK RIDGE NATL LAB,DIV ENVIRONM SCI,OAK RIDGE,TN 37831. NR 12 TC 5 Z9 5 U1 1 U2 1 PU NATL RESEARCH COUNCIL CANADA PI OTTAWA PA RESEARCH JOURNALS, MONTREAL RD, OTTAWA ON K1A 0R6, CANADA SN 0045-5067 J9 CAN J FOREST RES JI Can. J. For. Res.-Rev. Can. Rech. For. PD JUL PY 1991 VL 21 IS 7 BP 1119 EP 1123 DI 10.1139/x91-154 PG 5 WC Forestry SC Forestry GA HX879 UT WOS:A1991HX87900023 ER PT J AU OSTROWSKI, LE PEGRAM, CN VONWRONSKI, MA HUMPHREY, PA HE, XM SHIOTA, S MITRA, S BRENT, TP BIGNER, DD AF OSTROWSKI, LE PEGRAM, CN VONWRONSKI, MA HUMPHREY, PA HE, XM SHIOTA, S MITRA, S BRENT, TP BIGNER, DD TI PRODUCTION AND CHARACTERIZATION OF ANTIPEPTIDE ANTIBODIES AGAINST HUMAN O6-METHYLGUANINE-DNA METHYLTRANSFERASE SO CANCER RESEARCH LA English DT Article ID O-6-ALKYLGUANINE-DNA ALKYLTRANSFERASE; ESCHERICHIA-COLI; TUMOR XENOGRAFTS; ALKYLATED DNA; REPAIR; O-6-METHYLGUANINE; EXPRESSION; PROTEIN; ENZYME; PURIFICATION AB Four synthetic peptides from the sequence of human O6-methylguanine-DNA methyltransferase (MGMT), three corresponding to different hydrophilic regions and one corresponding to the sequence containing the alkyl acceptor residue cysteine 145, were used to immunize rabbits. The antibody against Peptide III (residues 171-184) was highly specific, and MGMT protein could be detected on Western blots of soluble protein extracts containing as little as 1 fmol of active MGMT. Antibodies against all of the peptides were able to immunoprecipitate denatured MGMT, while only the antibody against Peptide III was able to react with active enzyme. The antibody against Peptide III did not cross-react with methyltransferase from mice. The use of synthetic peptides has led to the production of a highly sensitive, specific antibody that recognizes native and denatured human MGMT. This antibody should prove useful in studies involving the detection, purification, and characterization of this enzyme. C1 DUKE UNIV, MED CTR, DEPT PATHOL, POB 3156, DURHAM, NC 27710 USA. DUKE UNIV, MED CTR, PREUSS LAB BRAIN TUMOR RES, DURHAM, NC 27710 USA. ST JUDE CHILDRENS RES HOSP, DEPT BIOCHEM & CLIN PHARMACOL, MEMPHIS, TN 38101 USA. UNIV TENNESSEE, GRAD SCH BIOMED SCI, OAK RIDGE, TN 37831 USA. OAK RIDGE NATL LAB, DIV BIOL, OAK RIDGE, TN 37831 USA. FU NCI NIH HHS [CA 11898, CA 32672]; NINDS NIH HHS [NS 20023] NR 24 TC 23 Z9 24 U1 0 U2 0 PU AMER ASSOC CANCER RESEARCH PI PHILADELPHIA PA 615 CHESTNUT ST, 17TH FLOOR, PHILADELPHIA, PA 19106-4404 USA SN 0008-5472 J9 CANCER RES JI Cancer Res. PD JUL 1 PY 1991 VL 51 IS 13 BP 3339 EP 3344 PG 6 WC Oncology SC Oncology GA FT764 UT WOS:A1991FT76400001 PM 2054774 ER PT J AU SINGH, SB HINGERTY, BE SINGH, UC GREENBERG, JP GEACINTOV, NE BROYDE, S AF SINGH, SB HINGERTY, BE SINGH, UC GREENBERG, JP GEACINTOV, NE BROYDE, S TI STRUCTURES OF THE (+)-TRANS-7,8-DIHYDROXY-ANTI-9,10-EPOXY-7,8,9,10-TETRAHYDROBENZO(A)PYREN E AND (-)-TRANS-7,8-DIHYDROXY-ANTI-9,10-EPOXY-7,8,9,10-TETRAHYDROBENZO(A)PYREN E ADDUCTS TO GUANINE-N2 IN A DUPLEX DODECAMER SO CANCER RESEARCH LA English DT Article ID DIASTEREOMERIC BENZOPYRENE 7,8-DIOL-9,10-EPOXIDES; POLYCYCLIC AROMATIC-HYDROCARBONS; STEREOSELECTIVE COVALENT BINDING; MOLECULAR-DYNAMICS SIMULATIONS; IRREGULAR NUCLEIC-ACIDS; EPOXIDE-DNA ADDUCTS; DIOL-EPOXIDE; OPTICAL ENANTIOMERS; LINEAR DICHROISM; BENZOPYRENE-7,8-DIHYDRODIOL 9,10-OXIDE AB The structures of the mirror image (+)- and (-)-trans-anti-adducts of 7,8-dihydroxy-9,10-epoxy-7,8,9,10-tetrahydrobenzo(a)pyrene to guanine N2 have been of great interest because the high biological activity of 7,8-dihydroxy-9,10 -epoxy-7,8,9,10-tetrahydrobenzo(a)pyrene in mammalian mutagenesis and tumorigenesis has been attributed to the predominant (+)-trans-anti-adduct. We have carried out new potential energy minimization studies, involving wide-scale conformational searches on small modified DNA subunits, followed by energy-minimized build-up techniques. to generate atomic resolution views of these adducts. These energy-minimized duplex dodecamers were then subjected to 100-ps molecular dynamic simulations with solvent and salt to yield animated molecular structures. The most favored computed structure for the (+)-adduct places the pyrenyl moiety in the B-DNA minor groove, with its long axis directed toward the 5' end of the modified strand, and with a pronounced bend in the helix axis. In the (-)-adduct, there are 2 favored structures. One places the pyrenyl moiety in the minor groove, whereas the other positions it in the major groove; in both cases, the pyrenyl long axis is directed more toward the 3' end of the modified strand, and with much less helix axis bend. Structures with intercalation character computed for these adducts are less preferred. The favored computed structures agree with spectroscopic data on the (+)- and (-)-trans-anti-adducts, whereas recent experimental evidence suggests that cis-adducts assume intercalation-type structures. Perhaps the conformational distinctions elucidated for the (+)- and (-)-trans-anti-adducts play a role in their differential tumorigenic properties in mammalian systems. C1 NYU, DEPT BIOL, 109 MAIN BLDG, WASHINGTON SQ, NEW YORK, NY 10003 USA. NYU, DEPT CHEM, NEW YORK, NY 10003 USA. OAK RIDGE NATL LAB, DIV HLTH & SAFETY RES, OAK RIDGE, TN 37831 USA. Scripps Res Inst, RES INST, DEPT MOLEC BIOL, LA JOLLA, CA 92037 USA. SAN DIEGO SUPERCOMP CTR, SAN DIEGO, CA 92186 USA. FU NCI NIH HHS [CA-28038]; NIGMS NIH HHS [GM-39310] NR 71 TC 55 Z9 55 U1 0 U2 1 PU AMER ASSOC CANCER RESEARCH PI PHILADELPHIA PA 615 CHESTNUT ST, 17TH FLOOR, PHILADELPHIA, PA 19106-4404 USA SN 0008-5472 J9 CANCER RES JI Cancer Res. PD JUL 1 PY 1991 VL 51 IS 13 BP 3482 EP 3492 PG 11 WC Oncology SC Oncology GA FT764 UT WOS:A1991FT76400023 PM 1905197 ER PT J AU HEISKANEN, KA RHIM, HC MONTEIRO, PJM AF HEISKANEN, KA RHIM, HC MONTEIRO, PJM TI COMPUTER-SIMULATIONS OF LIMITED ANGLE TOMOGRAPHY OF REINFORCED-CONCRETE SO CEMENT AND CONCRETE RESEARCH LA English DT Article AB Computed tomography (CT) with x-rays or gamma-rays has the potential of being a powerful tool in assessing the degree of damage in reinforced concrete structures. The traditional CT method consists of taking measurements from all directions around the structure. However in reinforced concrete structures the measurement device cannot be positioned around all the structure, and the measurement data are thus available only from a limited range of angles. In this paper a new algorithm is presented for reducing the effects of the limited angle problem. Computer simulations of limited angle tomography of reinforced concrete columns show that the proposed algorithm is robust and can significantly increase the power of tomography in civil engineering applications. RP HEISKANEN, KA (reprint author), UNIV CALIF BERKELEY LAWRENCE BERKELEY LAB,DEPT CIVIL ENGN,BERKELEY,CA 94720, USA. NR 9 TC 5 Z9 8 U1 0 U2 0 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD, ENGLAND OX5 1GB SN 0008-8846 J9 CEMENT CONCRETE RES JI Cem. Concr. Res. PD JUL PY 1991 VL 21 IS 4 BP 625 EP 634 DI 10.1016/0008-8846(91)90113-V PG 10 WC Construction & Building Technology; Materials Science, Multidisciplinary SC Construction & Building Technology; Materials Science GA FQ863 UT WOS:A1991FQ86300025 ER PT J AU Newman, WI Campbell, DK Hyman, JM AF Newman, William I. Campbell, David K. Hyman, James M. TI Identifying coherent structures in nonlinear wave propagation SO CHAOS LA English DT Article AB Nonlinear wave phenomena are often characterized by the appearance of ''solitary wave coherent structures'' traveling at speeds determined by their amplitudes and morphologies. Assuming that time intervals exist in which these structures are essentially noninteracting, a method for identifying the number of independent features and their respective speeds is proposed and developed. The method is illustrated with a variety of increasingly realistic specific applications, beginning with a simple nonlinear but analytically tractable Gaussian model, continuing with (numerically generated) data describing multisoliton solutions to the Korteweg-de Vries equation, and concluding with (numerical) data from a realistic simulation of nonlinear wave interactions in plasma turbulence. These studies reveal both strengths and limitations of the method in its present incarnation and suggest topics for future investigations. C1 [Newman, William I.; Campbell, David K.; Hyman, James M.] Univ Calif Los Alamos Natl Lab, Ctr Nonlinear Studies, Los Alamos, NM 87545 USA. [Hyman, James M.] Univ Calif Los Alamos Natl Lab, Div Theoret, Los Alamos, NM 87545 USA. [Newman, William I.] Univ Calif Los Angeles, Dept Earth & Space Sci, Los Angeles, CA 90024 USA. [Newman, William I.] Univ Calif Los Angeles, Dept Astron, Los Angeles, CA 90024 USA. [Newman, William I.] Univ Calif Los Angeles, Dept Math, Los Angeles, CA 90024 USA. RP Newman, WI (reprint author), Univ Calif Los Alamos Natl Lab, Ctr Nonlinear Studies, Los Alamos, NM 87545 USA. RI Newman, William/E-5918-2011 OI Newman, William/0000-0002-9835-1428 FU U.S. Department of Energy FX We are grateful to the U.S. Department of Energy for its support of this work. We are particularly grateful to Dan Winske for useful discussions and for making his magnetospheric simulation data44 available to us prior to publication, and to Philip Holmes for a critical reading of the manuscript and many useful comments. NR 44 TC 10 Z9 10 U1 1 U2 3 PU AMER INST PHYSICS PI MELVILLE PA CIRCULATION & FULFILLMENT DIV, 2 HUNTINGTON QUADRANGLE, STE 1 N O 1, MELVILLE, NY 11747-4501 USA SN 1054-1500 J9 CHAOS JI Chaos PD JUL PY 1991 VL 1 IS 1 BP 77 EP 94 DI 10.1063/1.165813 PG 18 WC Mathematics, Applied; Physics, Mathematical SC Mathematics; Physics GA V22XJ UT WOS:000208307600010 ER PT J AU SIMPSON, TB AF SIMPSON, TB TI ENERGY AND SECURITY SO CHEMICAL ENGINEERING LA English DT Letter RP SIMPSON, TB (reprint author), US DOE,WASHINGTON,DC 20545, USA. NR 0 TC 1 Z9 1 U1 0 U2 0 PU MCGRAW HILL INC PI NEW YORK PA 1221 AVENUE OF THE AMERICAS, NEW YORK, NY 10020 SN 0009-2460 J9 CHEM ENG-NEW YORK JI Chem. Eng. PD JUL PY 1991 VL 98 IS 7 BP 7 EP 8 PG 2 WC Engineering, Chemical SC Engineering GA FV859 UT WOS:A1991FV85900005 ER PT J AU NEWTON, MD AF NEWTON, MD TI QUANTUM CHEMICAL PROBES OF ELECTRON-TRANSFER KINETICS - THE NATURE OF DONOR-ACCEPTOR INTERACTIONS SO CHEMICAL REVIEWS LA English DT Review ID LONG-RANGE ELECTRON; THROUGH-BOND INTERACTIONS; TRANSITION-METAL COMPLEXES; PHOTOSYNTHETIC REACTION CENTER; PHOTOINDUCED CHARGE-SEPARATION; TRANSFER MATRIX-ELEMENTS; HARTREE-FOCK-SLATER; PI-PI INTERACTIONS; ABINITIO SCF-MO; DISTANCE DEPENDENCE RP BROOKHAVEN NATL LAB, DEPT CHEM, UPTON, NY 11973 USA. NR 204 TC 1212 Z9 1219 U1 10 U2 151 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 0009-2665 EI 1520-6890 J9 CHEM REV JI Chem. Rev. PD JUL-AUG PY 1991 VL 91 IS 5 BP 767 EP 792 DI 10.1021/cr00005a007 PG 26 WC Chemistry, Multidisciplinary SC Chemistry GA GB059 UT WOS:A1991GB05900008 ER PT J AU MAYER, TM ROGERS, JW MICHALSKE, TA AF MAYER, TM ROGERS, JW MICHALSKE, TA TI MECHANISM OF NUCLEATION AND ATOMIC LAYER GROWTH OF ALN ON SI SO CHEMISTRY OF MATERIALS LA English DT Article ID RAY PHOTOELECTRON-SPECTROSCOPY; MOLECULAR-BEAM; GAAS 100; EPITAXY; SURFACE; DECOMPOSITION; TRIMETHYLGALLIUM; DEPOSITION; GAAS(100); ALUMINUM AB We have studied by X-ray photoelectron spectroscopy the adsorption and decomposition of trimethylaluminum (TMA) on Si(100), the low-temperature formation of AlN from pyrolysis of TMA and NH3, and have demonstrated a mechanism for atomic layer growth of AlN at 600 K. TMA adsorbs dissociatively to Si at temperatures above 300 K. At < 650 K adsorption is self-limiting at < 1 monolayer, with most carbon remaining in the form of CH3. At higher temperatures, decomposition of the TMA is rapid, and continuous deposition is observed with production of carbides as the primary product. Coadsorption of TMA and NH3 at room temperature leads to formation of Al-N covalent bonding as well as a surface adduct species, Al:N, which is converted quantitatively to Al-N at higher temperature. At substrate temperatures < 550 K, coadsorption of TMA and NH3 is self-limiting at less than a monolayer, while above this temperature reaction to form AlN is rapid and continuous deposition is observed. Self-limiting adsorption of TMA at < 650 K and rapid, site-selective reaction with NH3 to from AlN at > 550 K satisfy the conditions for atomic layer growth of AlN at 600 K using sequential exposures of TMA and NH3. The chemical nature of the interfacial and growth surface are discussed. RP MAYER, TM (reprint author), SANDIA NATL LABS,ALBUQUERQUE,NM 87185, USA. NR 35 TC 33 Z9 33 U1 2 U2 13 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 SN 0897-4756 J9 CHEM MATER JI Chem. Mat. PD JUL-AUG PY 1991 VL 3 IS 4 BP 641 EP 646 DI 10.1021/cm00016a016 PG 6 WC Chemistry, Physical; Materials Science, Multidisciplinary SC Chemistry; Materials Science GA FZ190 UT WOS:A1991FZ19000016 ER PT J AU CISNEROS, MR AF CISNEROS, MR TI A TECHNICIANS DIVISION WITHIN ACS SO CHEMTECH LA English DT Editorial Material RP CISNEROS, MR (reprint author), UNIV CALIF LOS ALAMOS SCI LAB,DIV ISOTOPE & NUCL CHEM,LOS ALAMOS,NM 87545, USA. NR 2 TC 0 Z9 0 U1 0 U2 0 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 SN 0009-2703 J9 CHEMTECH JI Chemtech PD JUL PY 1991 VL 21 IS 7 BP 420 EP 421 PG 2 WC Chemistry, Applied SC Chemistry GA FW944 UT WOS:A1991FW94400009 ER PT J AU DAI, GX QI, YJ ZHENG, JW LIU, XM CHAN, Y STOKSTAD, RG HARMON, A POULIOT, J DIGREGORIO, D AF DAI, GX QI, YJ ZHENG, JW LIU, XM CHAN, Y STOKSTAD, RG HARMON, A POULIOT, J DIGREGORIO, D TI FISSION MEASUREMENT ON THE 5.5 TO 21.7 MEV/A SI-28 + AU-197 SYSTEM(II) ANGULAR-DISTRIBUTIONS OF ICF AND SF SO CHINESE PHYSICS LA English DT Article AB According to the distribution of linear-momentum transfer (LMT) obtained from the correlation measurement of fission partners, the events of Incomplete-Fusion Fission (ICF) and Sequential Fission (SF) were distinguished. The fission angular distributions of both ICF and SF were obtained. Calculating the moment of inertia by Cassinian Ovaloids as the fission shape, the angular distributions were fitted by current procedure. The spins of fissioning nuclei corresponding to ICF and SF are extracted. The relation between spin and bombarding energy is discussed. Besides, the angular distribution in coincidence with complex particles is discussed. C1 UNIV CALIF BERKELEY LAWRENCE BERKELEY LAB,DIV NUCL SCI,BERKELEY,CA 94720. RP DAI, GX (reprint author), ACAD SINICA,INST MODERN PHYS,POB 31,LANZHOU,PEOPLES R CHINA. NR 9 TC 0 Z9 0 U1 0 U2 0 PU AMER INST PHYSICS PI WOODBURY PA CIRCULATION FULFILLMENT DIV, 500 SUNNYSIDE BLVD, WOODBURY, NY 11797-2999 SN 0273-429X J9 CHINESE PHYS PD JUL-SEP PY 1991 VL 11 IS 3 BP 595 EP 601 PG 7 WC Physics, Multidisciplinary SC Physics GA GH590 UT WOS:A1991GH59000013 ER PT J AU WEIER, HUG LUCAS, JN POGGENSEE, M SEGRAVES, R PINKEL, D GRAY, JW AF WEIER, HUG LUCAS, JN POGGENSEE, M SEGRAVES, R PINKEL, D GRAY, JW TI 2-COLOR HYBRIDIZATION WITH HIGH COMPLEXITY CHROMOSOME-SPECIFIC PROBES AND A DEGENERATE ALPHA SATELLITE PROBE DNA ALLOWS UNAMBIGUOUS DISCRIMINATION BETWEEN SYMMETRICAL AND ASYMMETRICAL TRANSLOCATIONS SO CHROMOSOMA LA English DT Article ID FLUORESCENCE INSITU HYBRIDIZATION; HUMAN CENTROMERIC REGIONS; TUMOR-CELLS; ABERRATIONS; SEQUENCES; AMPLIFICATION; ORGANIZATION; INTERPHASE; METAPHASE AB This report describes a fluorescence in situ hybridization approach to chromosome staining that facilitates detection of structural aberrations and allows discrimination between dicentric chromosomes and symmetrically translocated chromosomes. In this approach, selected whole chromosomes are stained in one color by hybridization with composite probes whose elements have DNA sequence homology along the length of the target chromosomes. In addition, all chromosomes are counterstained with a DNA specific dye so that structural aberrations between target and non-target chromosomes are clearly visible. Discrimination between dicentric chromosomes and symmetrical translocations is accomplished by hybridization with a second probe that is homologous to DNA sequences found in the centromeric region of all chromosomes. The centromeric marker is visualized in a different color, so that the number of centromeres per aberrant chromosome can be rapidly determined in the microscope by changing excitation and fluorescence filters. RP WEIER, HUG (reprint author), UNIV CALIF LAWRENCE LIVERMORE NATL LAB,DIV BIOMED SCI,MAILSTOP L-452,POB 5507,LIVERMORE,CA 94550, USA. FU NICHD NIH HHS [HD17665] NR 35 TC 71 Z9 73 U1 0 U2 1 PU SPRINGER VERLAG PI NEW YORK PA 175 FIFTH AVE, NEW YORK, NY 10010 SN 0009-5915 J9 CHROMOSOMA JI Chromosoma PD JUL PY 1991 VL 100 IS 6 BP 371 EP 376 DI 10.1007/BF00337515 PG 6 WC Biochemistry & Molecular Biology; Genetics & Heredity SC Biochemistry & Molecular Biology; Genetics & Heredity GA FU778 UT WOS:A1991FU77800003 PM 1893794 ER PT J AU OLINS, DE OLINS, AL HERRMANN, A LIN, RL ALLIS, CD ROBERTNICOUD, M AF OLINS, DE OLINS, AL HERRMANN, A LIN, RL ALLIS, CD ROBERTNICOUD, M TI LOCALIZATION OF ACETYLATED HISTONE H4 IN THE MACRONUCLEUS OF EUPLOTES SO CHROMOSOMA LA English DT Article ID NUCLEOSOME CORE PARTICLE; REPLICATION BAND; CONJUGATING TETRAHYMENA; DNA-SYNTHESIS; EURYSTOMUS; CHROMATIN; HYPERACETYLATION; MICRONUCLEI; ANTIBODIES; SOLUBILITY AB Antisera specific to acetylated and unacetylated N-terminal domains of histone H4 were employed to map the spatial distribution of exposed antigenic determinants in the macronucleus of Euplotes eurystomus. Sites of putative transcription-related acetylation appear to reside in the regions between condensed chromatin granules and disappear during chromatin restructuring in the forward zone of replication bands. Coincident with synthesis of newly replicated chromatin, the specific antisera reveal a resumption of exposed sites of Hr acetylation in the rear zone of replication bands. C1 SYRACUSE UNIV,DEPT BIOL,SYRACUSE,NY 13244. U J FOURIER,ERFMG CERMO,F-38041 GRENOBLE,FRANCE. OAK RIDGE NATL LAB,DIV PHYS,OAK RIDGE,TN 37831. MAX PLANCK INST BIOPHYS CHEM,W-3400 GOTTINGEN,GERMANY. RP OLINS, DE (reprint author), UNIV TENNESSEE,OAK RIDGE GRAD SCH BIOMED SCI,POB 2009,OAK RIDGE,TN 37831, USA. NR 39 TC 9 Z9 9 U1 0 U2 0 PU SPRINGER VERLAG PI NEW YORK PA 175 FIFTH AVE, NEW YORK, NY 10010 SN 0009-5915 J9 CHROMOSOMA JI Chromosoma PD JUL PY 1991 VL 100 IS 6 BP 377 EP 385 DI 10.1007/BF00337516 PG 9 WC Biochemistry & Molecular Biology; Genetics & Heredity SC Biochemistry & Molecular Biology; Genetics & Heredity GA FU778 UT WOS:A1991FU77800004 ER PT J AU HAUSER, LJ ROBERSON, AE OLINS, DE AF HAUSER, LJ ROBERSON, AE OLINS, DE TI STRUCTURE OF THE MACRONUCLEAR POLYUBIQUITIN GENE IN EUPLOTES SO CHROMOSOMA LA English DT Article ID AMINO-ACID-SEQUENCE; UBIQUITIN-CONJUGATING ENZYME; NUCLEOTIDE-SEQUENCE; STYLONYCHIA-LEMNAE; TANDEM REPEATS; CODON USAGE; PROTEIN; DNA; EXPRESSION; CHROMATIN AB The hypotrichous ciliate, Euplotes eurystomus, contains both a transcriptionally inactive micronucleus (MIC) and a transcriptionally active macronucleus (MAC) in the same cell. MAC DNA is small (0.5-20 kb), linear and highly amplified. Each DNA fragment consists of two telomeres, a single coding region, and the necessary control elements to regulate gene transcription and replication. The polyubiquitin gene consists of 898 bp, plus 28 bp of double-stranded and 14 bases of single-stranded DNA of the telomeric repeat G4T4 at each end. The coding region exists as three copies of the ubiquitin gene (690 bp) fused in a head-to-tail arrangement as in other organisms. The stop codon is TAA, as in other Euplotes genes, and is not the rare glutamine codon used in most other ciliates. The 3' nontranslated region contains two presumptive poly(A) addition sites; the 5' nontranslated region possesses two putative TATA boxes, several imperfect direct and inverted repeats, and a possible origin of replication. Nucleosome positioning studies reveal four tightly packed nucleosomes and a non-nucleosomal area containing the probable 5' control region as well as part of the coding region. The 5' area does not contain any DNAse I hypersensitive sites. Although the telomeres are protected from exonuclease digestion, they are not as well protected as Oxytricha telomeres against endonucleases and cleavage by methidium propyl Fe2+ EDTA. C1 UNIV TENNESSEE,OAK RIDGE GRAD SCH BIOMED SCI,OAK RIDGE NATL LAB,DIV BIOL,POB 2009,OAK RIDGE,TN 37831. RI Hauser, Loren/H-3881-2012 FU NCI NIH HHS [T32CA09336]; NIGMS NIH HHS [GM07438] NR 58 TC 12 Z9 13 U1 0 U2 0 PU SPRINGER VERLAG PI NEW YORK PA 175 FIFTH AVE, NEW YORK, NY 10010 SN 0009-5915 J9 CHROMOSOMA JI Chromosoma PD JUL PY 1991 VL 100 IS 6 BP 386 EP 394 DI 10.1007/BF00337517 PG 9 WC Biochemistry & Molecular Biology; Genetics & Heredity SC Biochemistry & Molecular Biology; Genetics & Heredity GA FU778 UT WOS:A1991FU77800005 PM 1654239 ER PT J AU HERTZBERG, JR SHEPHERD, IG TALBOT, L AF HERTZBERG, JR SHEPHERD, IG TALBOT, L TI VORTEX SHEDDING BEHIND ROD STABILIZED FLAMES SO COMBUSTION AND FLAME LA English DT Article ID PREMIXED TURBULENT FLAMES; CIRCULAR-CYLINDER; BLUFF-BODIES; COMBUSTION; INSTABILITIES; FLAMEHOLDERS; ABSOLUTE; BLOWOFF; FLOW AB The stabilization of a premixed, turbulent V-shaped flame on a bluff body has been studied using laser Doppler anemometry for two-component velocity data, and Rayleigh scattering for point measurements of density. The conditions studied include isothermal flow, a lean ethylene flame at equivalence ratio-phi = 0.62, and a very lean (phi = 0.54) flame that is close to blow off for the free stream velocity of 6 m/s. Examination of velocity and density fluctuation spectra and fluctuation intensity contour maps reveals the first quantitative evidence of vortex shedding in the wake of a V-shaped flame under unperturbed free stream conditions. Vortex shedding accompanied by high periodic fluctuation intensities have been clearly identified in the cases of a very lean flame stabilized on a bar (6 x 3mm) and on a rod (6 mm diameter), and in a slightly richer bar stabilized case, but not as clearly for a richer rod-stabilized case. It is suggested that vortex shedding may play a role in the blowoff process, and that the assumption of steady recirculation is not always valid. C1 UNIV CALIF BERKELEY, DEPT MECH ENGN, BERKELEY, CA 94720 USA. UNIV CALIF BERKELEY LAWRENCE BERKELEY LAB, DIV APPL SCI, COMBUST GRP, BERKELEY, CA 94720 USA. NR 43 TC 39 Z9 40 U1 0 U2 6 PU ELSEVIER SCIENCE INC PI NEW YORK PA 360 PARK AVE SOUTH, NEW YORK, NY 10010-1710 USA SN 0010-2180 EI 1556-2921 J9 COMBUST FLAME JI Combust. Flame PD JUL PY 1991 VL 86 IS 1-2 BP 1 EP 11 DI 10.1016/0010-2180(91)90051-C PG 11 WC Thermodynamics; Energy & Fuels; Engineering, Multidisciplinary; Engineering, Chemical; Engineering, Mechanical SC Thermodynamics; Energy & Fuels; Engineering GA GA828 UT WOS:A1991GA82800001 ER PT J AU PHILLIPS, RL AF PHILLIPS, RL TI MEDIAVIEW - A GENERAL MULTIMEDIA DIGITAL PUBLICATION SYSTEM SO COMMUNICATIONS OF THE ACM LA English DT Article RP PHILLIPS, RL (reprint author), UNIV CALIF LOS ALAMOS SCI LAB,DIV COMP & COMMUN,COMP GRAPH GRP,BIKINI RD MS B-272,LOS ALAMOS,NM 87545, USA. NR 21 TC 4 Z9 5 U1 0 U2 2 PU ASSOC COMPUTING MACHINERY PI NEW YORK PA 1515 BROADWAY, NEW YORK, NY 10036 SN 0001-0782 J9 COMMUN ACM JI Commun. ACM PD JUL PY 1991 VL 34 IS 7 BP 74 EP 83 DI 10.1145/105783.105799 PG 10 WC Computer Science, Hardware & Architecture; Computer Science, Software Engineering; Computer Science, Theory & Methods SC Computer Science GA FU162 UT WOS:A1991FU16200014 ER PT J AU GYULASSY, M HARLANDER, M AF GYULASSY, M HARLANDER, M TI ELASTIC TRACKING AND NEURAL NETWORK ALGORITHMS FOR COMPLEX PATTERN-RECOGNITION SO COMPUTER PHYSICS COMMUNICATIONS LA English DT Article ID HIGH-ENERGY PHYSICS; DETECTOR AB A new elastic tracking (ET) algorithm is proposed for finding tracks in very high multiplicity and noise environments. It is based on a dynamical reinterpretation and generalization of the Radon transform and is related to elastic net algorithms for geometrical optimization. ET performs an adaptive nonlinear fit to noisy data with a variable number of tracks and is more efficient numerically than the traditional Radon or Hough transform method, because it avoids binning of phase space and the costly search for valid minima. Spurious local minima are avoided in ET by introducing an iteration time-dependent effective potential. The method is shown to be very robust to noise and measurement error and extends tracking capabilities to much higher track densities than possible via local road finding or even the novel Denby-Peterson (DP) neural network tracking algorithms. A possible neural network implementation of ET is also discussed. C1 TECH UNIV MUNICH,DEPT PHYS T30,W-8046 GARCHING,GERMANY. RP GYULASSY, M (reprint author), UNIV CALIF BERKELEY LAWRENCE BERKELEY LAB,DIV NUCL SCI,BERKELEY,CA 94720, USA. NR 19 TC 38 Z9 38 U1 0 U2 0 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0010-4655 J9 COMPUT PHYS COMMUN JI Comput. Phys. Commun. PD JUL PY 1991 VL 66 IS 1 BP 31 EP 46 DI 10.1016/0010-4655(91)90005-6 PG 16 WC Computer Science, Interdisciplinary Applications; Physics, Mathematical SC Computer Science; Physics GA FZ569 UT WOS:A1991FZ56900004 ER PT J AU HOSTICK, CJ BILLO, RE RUCKER, RH AF HOSTICK, CJ BILLO, RE RUCKER, RH TI MAKING THE MOST OF STRUCTURED ANALYSIS IN MANUFACTURING INFORMATION-SYSTEM DESIGN - APPLICATION OF ICONS AND CYCLE-TIME SO COMPUTERS IN INDUSTRY LA English DT Article DE STRUCTURED ANALYSIS; CASE; MANUFACTURING INFORMATION SYSTEMS; SOFTWARE ENGINEERING; ICONS; CYCLE-TIME; COGNITIVE SCIENCE AB An attempt was made to extend the usefulness of structured analysis for modeling the as-is manufacturing information data flows, by enriching both its perspective and its tools. The change in perspective involved a re-emphasis on modeling the current as-is information system as completely as possible. To support this change in perspective, an additional tool set was proposed that is to be incorporated into the structured analysis paradigm. This tool set has been termed Icon-Based Structured Analysis (ISA). The tool set includes text and mathematically-tagged iconic-based modeling techniques; these techniques include both numeric attribute cycle-time components for showing process, as well as visually oriented, user-specific graphic components that display structure. In effect, ISA extends the syntactic and interpretative elements available to the structured analysis modeler and thus allows the display of additional high-level abstractions that are understandable and analyzable by both user and modeler. This capability allows the analyst and user to move quickly to agreement on the desired characteristics of the proposed information system. C1 PACIFIC NW LAB, RICHLAND, WA 99352 USA. ARIZONA STATE UNIV, DEPT IND & MANAGEMENT SYST ENGN, TEMPE, AZ 85287 USA. NR 9 TC 2 Z9 2 U1 0 U2 0 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0166-3615 J9 COMPUT IND JI Comput. Ind. PD JUL PY 1991 VL 16 IS 3 BP 267 EP 278 DI 10.1016/0166-3615(91)90064-G PG 12 WC Computer Science, Interdisciplinary Applications SC Computer Science GA FY550 UT WOS:A1991FY55000004 ER PT J AU ELLIOTT, SR ROBERTSON, RGH AF ELLIOTT, SR ROBERTSON, RGH TI DETECTING NEUTRINOS FROM THE SUN SO CONTEMPORARY PHYSICS LA English DT Article ID SOLAR-NEUTRINO; OSCILLATIONS; BURST AB The Sun shines brightly to our eyes, but is three times dimmer in neutrinos than it should be for the amount of energy it is producing. How that can happen has been a mystery for twenty years. It was long thought to be an error in our understanding of how the Sun works, but new experiments and new ideas about particle physics are lending support to the possibility that it is the neutrino itself that was not understood. If so, a revolution in particle physics and our understanding of the universe may be at hand. We describe the remarkable experiments that have brought us to this point, and new ones to come. RP ELLIOTT, SR (reprint author), UNIV CALIF LOS ALAMOS SCI LAB,DIV PHYS,LOS ALAMOS,NM 87545, USA. NR 34 TC 0 Z9 0 U1 0 U2 0 PU TAYLOR & FRANCIS LTD PI LONDON PA ONE GUNDPOWDER SQUARE, LONDON, ENGLAND EC4A 3DE SN 0010-7514 J9 CONTEMP PHYS JI Contemp. Phys. PD JUL-AUG PY 1991 VL 32 IS 4 BP 251 EP 263 DI 10.1080/00107519108223699 PG 13 WC Physics, Multidisciplinary SC Physics GA GK768 UT WOS:A1991GK76800003 ER PT J AU FRANKLIN, MJ NIVENS, DE GUCKERT, JB WHITE, DC AF FRANKLIN, MJ NIVENS, DE GUCKERT, JB WHITE, DC TI EFFECT OF ELECTROCHEMICAL IMPEDANCE SPECTROSCOPY ON MICROBIAL BIOFILM CELL NUMBERS, VIABILITY, AND ACTIVITY SO CORROSION LA English DT Note C1 UNIV TENNESSEE,INST APPL MICROBIOL,KNOXVILLE,TN 37932. UNIV TENNESSEE,DEPT MICROBIOL,KNOXVILLE,TN 37932. OAK RIDGE NATL LAB,DIV ENVIRONM SCI,OAK RIDGE,TN 37831. UNIV TENNESSEE,DEPT CHEM,KNOXVILLE,TN 37996. NR 9 TC 16 Z9 18 U1 1 U2 3 PU NATL ASSN CORROSION ENG PI HOUSTON PA 1440 SOUTH CREEK DRIVE, HOUSTON, TX 77084-4906 SN 0010-9312 J9 CORROSION JI Corrosion PD JUL PY 1991 VL 47 IS 7 BP 519 EP 522 PG 4 WC Materials Science, Multidisciplinary; Metallurgy & Metallurgical Engineering SC Materials Science; Metallurgy & Metallurgical Engineering GA HC475 UT WOS:A1991HC47500004 ER PT J AU JONES, RH WINDISCH, CF AREY, BW BAER, DR AF JONES, RH WINDISCH, CF AREY, BW BAER, DR TI GRAIN-BOUNDARY CHEMISTRY EFFECTS ON THE INTERGRANULAR STRESS-CORROSION OF IRON-ALLOYS IN SULFATE AND NITRATE SOLUTIONS SO CORROSION LA English DT Article DE GRAIN-BOUNDARY CHEMISTRY; IRON; NITRATE SOLUTIONS, STRESS CORROSION CRACKING; SUBCRITICAL CRACK GROWTH; SULFATE ID CRACKING; PHOSPHORUS; STEEL AB Intergranular stress corrosion measurements have been made on Fe alloys in 1 M sodium sulfate at electrochemical potentials of +750 to +1250 mV(SCE) and in 55% calcium nitrate at 60-degrees-C and +750 mV(SCE). Tests were conducted on Fe with variable grain-boundary S and P concentrations ranging from 0.04 to 0.23 monolayers of S and 0 to 0.31 monolayers of P. Compact tension samples were used to measure the subcritical crack growth behavior. The calcium nitrate solutions were considerably more effective in causing crack growth of Fe than was the sodium sulfate solution. Crack growth thresholds, K(ISCC), of 6 MPa square-root m and 3 MPa square-root m were observed for Fe with 0.23 monolayers of S and 0.31 monolayers of P, respectively, when tested in calcium nitrate and 13 MPa square-root m when tested in sodium sulfate. A clear correlation was observed between the total S + P grain-boundary concentration and K(ISCC) and crack velocity. The crack growth rates were about a factor of 10 faster in nitrate than sulfate. In general, the crack growth behavior is consistent with an electrochemical mechanism being the dominant process; however, the stage II velocities of 10(-5) m/s observed in the nitrate solution are considerably faster than can be explained by anodic dissolution and long-range, steady-state transport away from the crack tip. Therefore, some form of mechanical fracture contributing to the crack velocity cannot be ruled out, but evidence for such a mechanism has not been observed. C1 PACIFIC NW LAB, RICHLAND, WA 99352 USA. RI Baer, Donald/J-6191-2013 OI Baer, Donald/0000-0003-0875-5961 NR 18 TC 12 Z9 12 U1 0 U2 2 PU NATL ASSN CORROSION ENG PI HOUSTON PA 1440 SOUTH CREEK DRIVE, HOUSTON, TX 77084-4906 SN 0010-9312 J9 CORROSION JI Corrosion PD JUL PY 1991 VL 47 IS 7 BP 542 EP 554 PG 13 WC Materials Science, Multidisciplinary; Metallurgy & Metallurgical Engineering SC Materials Science; Metallurgy & Metallurgical Engineering GA HC475 UT WOS:A1991HC47500008 ER PT J AU DRESNER, L AF DRESNER, L TI SUPERCONDUCTOR STABILITY 90 - A REVIEW SO CRYOGENICS LA English DT Article; Proceedings Paper CT INTERNATIONAL SYMP ON SUPERCONDUCTOR STABILITY ( SSS 90 ) CY NOV 13-15, 1990 CL YOKOHAMA NATL UNIV, YOKOHAMA, JAPAN SP INST ELECT ENGINEERS JAPAN, CRYOGEN ASSOC JAPAN, MINIST EDUC JAPAN HO YOKOHAMA NATL UNIV DE SUPERCONDUCTORS; STABILITY; REVIEW ID IN-CONDUIT SUPERCONDUCTORS; CABLE; CONDUCTORS; PRESSURE; EXPULSION; MARGINS AB This paper reviews some recent developments in the field of stability of superconductors. The main topics dealt with are: 1, hydrodynamic phenomena in cable-in-conduit super-conductors, namely, multiple stability, quench pressure, thermal expulsion and thermal hydraulic quenchback; 2, travelling normal zones in large, composite conductors, such as those intended for SMES; and 3, the stability of vapour cooled leads made of high temperature superconductors. RP DRESNER, L (reprint author), OAK RIDGE NATL LAB,POB 2009,OAK RIDGE,TN 37831, USA. NR 30 TC 21 Z9 21 U1 0 U2 0 PU BUTTERWORTH-HEINEMANN LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD, OXON, ENGLAND OX5 1GB SN 0011-2275 J9 CRYOGENICS JI Cryogenics PD JUL PY 1991 VL 31 IS 7 BP 489 EP 498 DI 10.1016/0011-2275(91)90034-T PG 10 WC Thermodynamics; Physics, Applied SC Thermodynamics; Physics GA FZ610 UT WOS:A1991FZ61000002 ER PT J AU BOTTURA, L MITCHELL, N MINERVINI, JV AF BOTTURA, L MITCHELL, N MINERVINI, JV TI DESIGN CRITERIA FOR STABILITY IN CABLE-IN-CONDUIT CONDUCTORS SO CRYOGENICS LA English DT Article; Proceedings Paper CT INTERNATIONAL SYMP ON SUPERCONDUCTOR STABILITY ( SSS 90 ) CY NOV 13-15, 1990 CL YOKOHAMA NATL UNIV, YOKOHAMA, JAPAN SP INST ELECT ENGINEERS JAPAN, CRYOGEN ASSOC JAPAN, MINIST EDUC JAPAN HO YOKOHAMA NATL UNIV DE SUPERCONDUCTORS; STABILITY; DESIGN CRITERIA ID HEAT-TRANSFER; SUPERCONDUCTORS; HELIUM AB Stability is a key point in the design of large conductors for application in fusion machines such as NET or ITER. In the electromagnetically noisy environment characterizing the surroundings of a plasma, the superconductor should be stable against all expected heat deposition, including a.c. losses driven by plasma disruptions. Since all sources of thermal perturbations cannot be adequately identified, predicted or calculated, the design must allow for suitable margins. To ensure this, stability must be considered as a design criterion which is checked by means of analytical and numerical methods and later calibrated against experimental measurements of transient heat transfer and stability behaviour. In this the procedure developed at NET is described for the design and analysis of the stability margin of conductors for the toroidal and poloidal field coils. These methods are applied to the generation of stability curves and maps which are used to set operating limits for the 40 kA NET conductor. The design criteria and analytical methods can be appropriately modified for other conductors and coil applications. C1 UNIV CALIF LOS ALAMOS SCI LAB,LOS ALAMOS,NM 87545. RP BOTTURA, L (reprint author), MAX PLANCK INST PLASMA PHYS,NET TEAM,BOLTZMANNSTR 2,W-8046 GARCHING,GERMANY. NR 14 TC 16 Z9 19 U1 0 U2 4 PU BUTTERWORTH-HEINEMANN LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD, OXON, ENGLAND OX5 1GB SN 0011-2275 J9 CRYOGENICS JI Cryogenics PD JUL PY 1991 VL 31 IS 7 BP 510 EP 515 DI 10.1016/0011-2275(91)90037-W PG 6 WC Thermodynamics; Physics, Applied SC Thermodynamics; Physics GA FZ610 UT WOS:A1991FZ61000005 ER PT J AU DRESNER, L AF DRESNER, L TI THEORY OF THERMAL HYDRAULIC QUENCHBACK IN CABLE-IN-CONDUIT SUPERCONDUCTORS SO CRYOGENICS LA English DT Article; Proceedings Paper CT INTERNATIONAL SYMP ON SUPERCONDUCTOR STABILITY ( SSS 90 ) CY NOV 13-15, 1990 CL YOKOHAMA NATL UNIV, YOKOHAMA, JAPAN SP INST ELECT ENGINEERS JAPAN, CRYOGEN ASSOC JAPAN, MINIST EDUC JAPAN HO YOKOHAMA NATL UNIV DE SUPERCONDUCTORS; QUENCH PROTECTION; CABLE-IN-CONDUIT SUPERCONDUCTORS AB In a numerical simulation of the motion induced by local heating of the helium in a cable-inconduit superconductor Luongo et al. discovered a new phenomenon they called thermal hydraulic quenchback. After the creation of a local normal zone, its expansion compresses and displaces adjacent cold helium. This compression and displacement heat the cold helium and case long segments of the conductor rapidly to become normal. The propagation velocity thus appears to increase rather suddenly. The present paper describes an analytical study of this phenomenon. The main result is a simple formula for the time at which thermal hydraulic quenchback first starts. RP DRESNER, L (reprint author), OAK RIDGE NATL LAB,POB 2009,OAK RIDGE,TN 37831, USA. NR 7 TC 9 Z9 9 U1 0 U2 1 PU BUTTERWORTH-HEINEMANN LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD, OXON, ENGLAND OX5 1GB SN 0011-2275 J9 CRYOGENICS JI Cryogenics PD JUL PY 1991 VL 31 IS 7 BP 557 EP 561 DI 10.1016/0011-2275(91)90047-Z PG 5 WC Thermodynamics; Physics, Applied SC Thermodynamics; Physics GA FZ610 UT WOS:A1991FZ61000015 ER PT J AU GUTHRIE, GD VEBLEN, DR NAVON, O ROSSMAN, GR AF GUTHRIE, GD VEBLEN, DR NAVON, O ROSSMAN, GR TI SUBMICROMETER FLUID INCLUSIONS IN TURBID-DIAMOND COATS SO EARTH AND PLANETARY SCIENCE LETTERS LA English DT Article ID ELECTRON-PROBE; MANTLE; PRESSURE; COESITE; TEMPERATURE; KIMBERLITE; ORIGIN; GROWTH; CARBON; QUARTZ AB Transmission and analytical electron microscopies were used to characterize the turbid coats on two diamonds from Zaire. The coats contained euhedral cavities (generally less-than-or-equal-to 0.5-mu-m) that are believed to represent decrepit fluid inclusions. Crystals (generally less-than-or-equal-to 0.2-mu-m) were sometimes found in the cavities, but they were never observed to fill the cavities entirely. Cavities that appeared to be intact typically contained several solid inclusions and an amorphous material with a low average atomic weight. The crystals in such cavities were able to move under a condensed electron beam, suggesting that the amorphous material was a liquid and not a glass. Using compositional analysis and electron diffraction, five minerals were identified as daughter crystals in the cavities: apatite, high-Ca carbonate, low-Ca carbonate, mica, and quartz. Coesite and olivine were not observed in any of the cavities. Compositional analysis of some crystals indicated that other minerals (e.g., amphibole) were present as daughter crystals; however, electron diffraction data were insufficient to identify them unambiguously. Since these inclusions are believed to have been trapped during the growth of the diamond coats [1], it may be possible to constrain the environment under which the coats grew, assuming that the daughter minerals precipitated from the trapped fluid and that the fluid inclusions have not re-equilibrated. Coexisting magnesite-like and dolomite-like carbonates and silica constrain X(CO2) of the fluid to greater than 0.4. The presence of quartz is consistent with the coats developing at lower pressures and temperatures than the cores they surround; alternatively, quartz grew from a glass or a high-P, high-T silica polymorph (coesite) when the inclusions re-equilibrated in the quartz stability field. C1 UNIV CALIF LOS ALAMOS SCI LAB,LOS ALAMOS,NM 87545. JOHNS HOPKINS UNIV,DEPT EARTH & PLANETARY SCI,BALTIMORE,MD 21218. DEPT GEOL & PLANETARY SCI,PASADENA,CA 91125. RI Navon, Oded/N-9649-2013; OI Navon, Oded/0000-0003-4617-1553; Rossman, George/0000-0002-4571-6884 NR 40 TC 63 Z9 66 U1 1 U2 5 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0012-821X J9 EARTH PLANET SC LETT JI Earth Planet. Sci. Lett. PD JUL PY 1991 VL 105 IS 1-3 BP 1 EP 12 DI 10.1016/0012-821X(91)90116-Y PG 12 WC Geochemistry & Geophysics SC Geochemistry & Geophysics GA GD519 UT WOS:A1991GD51900001 ER PT J AU WANG, J BRENNSTEINER, A SYLWESTER, AP RENSCHLER, CL AF WANG, J BRENNSTEINER, A SYLWESTER, AP RENSCHLER, CL TI PREPARATION AND CHARACTERIZATION OF BAND NANOELECTRODES MADE OF CARBONIZED POLYACRYLONITRILE FILMS SO ELECTROANALYSIS LA English DT Article ID ELECTRODES AB We describe the fabrication and characterization of new nanoband electrodes, based on ultrathin carbon films produced by carbonization of deposited polyacrylonitrile. Because of their controlled thickness (down to molecular dimensions) and high electrical conductivity, such electrodes show great promise for electroanalytical work. Sigmoidal voltammograms, characteristic of nonlinear diffusion, are obtained. Direct measurements in electrolyte-free organic media are illustrated. Effects of band thickness, scan rate, solute and electrolyte concentrations, and other variables are explored. These films and other forms of carbon from polyacrylonitrile present opportunities for a wide range of electrode materials. C1 SANDIA NATL LABS,DIV 1811,ALBUQUERQUE,NM 87185. RP WANG, J (reprint author), NEW MEXICO STATE UNIV,DEPT CHEM,LAS CRUCES,NM 88003, USA. RI Wang, Joseph/C-6175-2011 NR 15 TC 12 Z9 12 U1 0 U2 5 PU VCH PUBLISHERS INC PI DEERFIELD BEACH PA 303 NW 12TH AVE, DEERFIELD BEACH, FL 33442-1788 SN 1040-0397 J9 ELECTROANAL JI Electroanalysis PD JUL PY 1991 VL 3 IS 6 BP 505 EP 509 DI 10.1002/elan.1140030610 PG 5 WC Chemistry, Analytical; Electrochemistry SC Chemistry; Electrochemistry GA FZ240 UT WOS:A1991FZ24000008 ER PT J AU GIOMETTI, CS GEMMELL, MA TOLLAKSEN, SL TAYLOR, J AF GIOMETTI, CS GEMMELL, MA TOLLAKSEN, SL TAYLOR, J TI QUANTITATION OF HUMAN-LEUKOCYTE PROTEINS AFTER SILVER STAINING - A STUDY WITH 2-DIMENSIONAL ELECTROPHORESIS SO ELECTROPHORESIS LA English DT Article ID POLYACRYLAMIDE-GEL ELECTROPHORESIS; TWO-DIMENSIONAL ELECTROPHORESIS; TISSUE PROTEINS; LIVER PROTEINS; CELL FRACTIONS; EXPRESSION; MUTATIONS; PATTERNS; VARIANTS; SERUM AB The quantitative attributes of human leukocyte proteins detected by silver staining two-dimensional electrophoresis (2-DE) gels were studied by using computer-assisted data analysis. Experiments included (a) analysis of replicate patterns of the same sample, (b) analysis of different dilutions of the same sample, and (c) analysis of samples from different individuals. Over 200 proteins were observed to have coefficients of variation (CV) less than or equal to 15 % when data from replicate patterns were analyzed. In contrast, 8 proteins had CV values of less than or equal to 15 % when data from different samples were analyzed. The dilution experiment showed that a majority of the proteins detected with some consistency (i.e., observed in at least 80% of the patterns) have a linear relationship between the amount of protein loaded onto a 2-DE gel and the spot volume in the final 2-DE pattern. The slope of the curves and the deviation from linearity were found to be quite protein-specific. These results indicate that optimization of sample purity and minimization of staining protocol variables are required to limit the background quantitative variability between and within 2-DE runs to a level that will allow detection of quantitative changes indicative of biological responses. RP GIOMETTI, CS (reprint author), ARGONNE NATL LAB,DIV BIOL & MED RES,BLDG 202,RM 4121,ARGONNE,IL 60439, USA. NR 27 TC 58 Z9 58 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 JUL-AUG PY 1991 VL 12 IS 7-8 BP 536 EP 543 DI 10.1002/elps.1150120713 PG 8 WC Biochemical Research Methods; Chemistry, Analytical SC Biochemistry & Molecular Biology; Chemistry GA FY558 UT WOS:A1991FY55800012 PM 1717251 ER PT J AU GNIRKE, A BARNES, TS PATTERSON, D SCHILD, D FEATHERSTONE, T OLSON, MV AF GNIRKE, A BARNES, TS PATTERSON, D SCHILD, D FEATHERSTONE, T OLSON, MV TI CLONING AND INVIVO EXPRESSION OF THE HUMAN GART GENE USING YEAST ARTIFICIAL CHROMOSOMES SO EMBO JOURNAL LA English DT Article DE CHROMOSOME-21; GENE TRANSFER; PURINE BIOSYNTHESIS; RESTRICTION MAPPING; YEAST ARTIFICIAL CHROMOSOME ID GLYCINAMIDE RIBONUCLEOTIDE TRANSFORMYLASE; FUNCTIONAL COMPLEMENTATION; MAMMALIAN-CELLS; HIGH-RESOLUTION; DNA-MOLECULES; SYNTHETASE; LIBRARIES; HYBRIDIZATION; BIOSYNTHESIS; REGION AB Two Yeast Artificial Chromosomes (YACs) were isolated each with a full-length copy of the human gene that encodes the trifunctional protein containing phosphoribosylglycinamide synthetase (GARS), phosphoribosylglycinamide formyltransferase (GART) and phosphoribosylaminoimidazole synthetase (AIRS). The YACs were characterized by restriction mapping and by in situ hybridization of cosmid subclones containing the YAC ends to human metaphase chromosomes. One of the YACs contains co-cloned non-contiguous DNA whereas the other appears to have a single 600 kbp insert from 21q22.1, the location of the GART gene. A restriction map of the gene was obtained from two cosmid subclones which together span the 40 kb gene. The gene is functional when YAC DNA is transferred into GARS- or GARS-and-AIRS-deficient Chinese Hamster Ovary cells. The gene transfer was carried out both by lipofection using purified yeast DNA and by fusion between yeast spheroplasts and the hamster cells. Restriction analysis of DNA from cell lines whose purine auxotrophy was complemented by the YAC showed that with either method a complete and unrearranged copy of the gene can be transferred. The majority of the fusion cell lines appear to contain at least 80% of the YAC. C1 WASHINGTON UNIV, SCH MED, HOWARD HUGHES MED INST, ST LOUIS, MO 63110 USA. ELEANOR ROOSEVELT INST CANC RES, DENVER, CO 80206 USA. UNIV CALIF BERKELEY LAWRENCE BERKELEY LAB, DIV CELL & MOLEC BIOL, BERKELEY, CA 94720 USA. RP WASHINGTON UNIV, SCH MED, DEPT GENET, ST LOUIS, MO 63110 USA. FU NICHD NIH HHS [HD22720] NR 36 TC 56 Z9 56 U1 0 U2 0 PU WILEY-BLACKWELL PI HOBOKEN PA 111 RIVER ST, HOBOKEN 07030-5774, NJ USA SN 0261-4189 EI 1460-2075 J9 EMBO J JI Embo J. PD JUL PY 1991 VL 10 IS 7 BP 1629 EP 1634 PG 6 WC Biochemistry & Molecular Biology; Cell Biology SC Biochemistry & Molecular Biology; Cell Biology GA FR684 UT WOS:A1991FR68400003 PM 2050105 ER PT J AU HOF, JV LAMM, SS AF HOF, JV LAMM, SS TI SINGLE-STRANDED REPLICATION INTERMEDIATES OF RIBOSOMAL DNA REPLICONS OF PEA SO EMBO JOURNAL LA English DT Article DE DISPLACEMENT LOOPS; PISUM SATIVUM; RDNA REPLICONS; REPLICATION; SINGLE-STRANDED DNA ID PISUM-SATIVUM; RNA GENES; MAMMALIAN-CELLS; ROOT-CELLS; CEREVISIAE; VARIANTS; ORIGINS; CYCLE; RDNA AB Replication of ribosomal DNA replicons in cells of Pisum sativum (cv. Alaska) occurs bidirectionally by displacement loops. Replication is initiated on opposite parental strands and nascent chains are elongated moving 5' --> 3' along each parental template. Replicative intermediates were analyzed by 2-dimensional agarose gel electrophoresis under neutral - neutral and neutral - alkaline conditions. Southern blots of ribosomal DNA fragments separated in the second dimension under neutral conditions show slowly migrating replicative fragments that hybridize with specific probes in a manner consistent with bidirectional replication. The replicative fragments are present in root meristems with cells in S phase; they are absent or few in number in meristems with cells in G2 phase. The following observations indicate that the replicative fragments are single stranded. The apparent length of the replicative fragments is not the same when separated under neutral and alkaline conditions. They contain rDNA without breaks and they do not exhibit the smaller nascent chains expected from replication bubbles and forks. They are not cleaved by restriction enzymes that require duplex DNA as substrate and they are digestible by S1 nuclease. RP HOF, JV (reprint author), BROOKHAVEN NATL LAB,DEPT BIOL,UPTON,NY 11973, USA. NR 25 TC 0 Z9 0 U1 0 U2 0 PU OXFORD UNIV PRESS UNITED KINGDOM PI OXFORD PA WALTON ST JOURNALS DEPT, OXFORD, ENGLAND OX2 6DP SN 0261-4189 J9 EMBO J JI Embo J. PD JUL PY 1991 VL 10 IS 7 BP 1949 EP 1953 PG 5 WC Biochemistry & Molecular Biology; Cell Biology SC Biochemistry & Molecular Biology; Cell Biology GA FR684 UT WOS:A1991FR68400039 ER PT J AU TORVANGER, A AF TORVANGER, A TI MANUFACTURING SECTOR CARBON-DIOXIDE EMISSIONS IN 9 OECD COUNTRIES, 1973-87 - A DIVISIA INDEX DECOMPOSITION TO CHANGES IN FUEL MIX, EMISSION COEFFICIENTS, INDUSTRY STRUCTURE, ENERGY INTENSITIES AND INTERNATIONAL STRUCTURE SO ENERGY ECONOMICS LA English DT Article DE DESCRIPTIVE INDUSTRIAL ANALYSIS; ENERGY USE; CARBON DIOXIDE EMISSIONS AB The reduction in energy-related manufacturing carbon dioxide emissions for nine OECD countries for 1973-87 is analysed. Carbon dioxide emissions are estimated from energy use data. The emphasis is on carbon dioxide intensities, defined as emissions divided by value added. The overall manufacturing carbon dioxide intensity was reduced by 42% in the period. Four fuels are specified together with six subsectors of manufacturing. A Divisia index approach is used to evaluate the contribution to reduced carbon dioxide intensity from different components. The main contribution to reduced carbon dioxide intensity is from the general reduction in manufacturing energy intensity, most likely driven by economic growth and increased energy prices, giving incentives to invest in new technology and industrial processes. There is also a significant contribution from reduced production in the most carbon dioxide intensive subsectors, and a contribution from higher efficiency in electricity generation together with a larger nuclear power share at the expense of oil. C1 UNIV CALIF BERKELEY LAWRENCE BERKELEY LAB,BERKELEY,CA 94720. RP TORVANGER, A (reprint author), SAF,CTR APPL RES,GAUSTADALLEEN 21,N-0371 OSLO 3,NORWAY. NR 19 TC 72 Z9 79 U1 1 U2 6 PU BUTTERWORTH-HEINEMANN LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD, OXON, ENGLAND OX5 1GB SN 0140-9883 J9 ENERG ECON JI Energy Econ. PD JUL PY 1991 VL 13 IS 3 BP 168 EP 186 DI 10.1016/0140-9883(91)90018-U PG 19 WC Economics SC Business & Economics GA FV445 UT WOS:A1991FV44500003 ER PT J AU GILES, HN KOENIG, JWJ NEIHOF, RA SHAY, JY WOODWARD, PW AF GILES, HN KOENIG, JWJ NEIHOF, RA SHAY, JY WOODWARD, PW TI STABILITY OF REFINED PRODUCTS AND CRUDE-OIL STORED IN LARGE CAVITIES IN SALT DEPOSITS - BIOGEOCHEMICAL ASPECTS SO ENERGY & FUELS LA English DT Article AB Large cavities in salt deposits have been used in a number of countries for stocking petroleum in strategic reserves and for operational storage. Stocks have included hydrocarbon gases, motor gasoline, home heating oil, jet fuel, and crude oil. Crude oil is not subject to deleterious changes in quality, although it does tend to deposit sludge during storage. No changes in quality of light hydrocarbons such as propane and butane have been reported. During storage in solution-mined cavities, gasoline and middle distillates can become contaminated with brine causing them to fail certain specification tests. Oxygen brought in with the water used to leach cavities can promote autoxidation resulting in formation of soluble or insoluble gum in some products. The walls of salt cavities are largely inert with respect to stored petroleum, and no reactions between them have been reported. Biodeterioration of petroleum is generally inhibited by the high salinity of the brine, but episodic bacterial activity could occur following injections of relatively fresh surface water resulting in catabolism of hydrocarbons, or production of hydrogen sulfide or methane. With careful planning and exercise of a few precautions, most quality problems encountered to date can be avoided. Petroleum stored in cavities in salt should not need to be rolled over as frequently to maintain its quality as it would if stored in aboveground tanks. C1 ERDOLBEVORRATUNGSVERBAND,W-2000 HAMBURG 36,GERMANY. USN,RES LAB,WASHINGTON,DC 20375. NATL INST PETROL & ENERGY RES,BARTLESVILLE,OK 74005. RP GILES, HN (reprint author), US DOE,OFF STRATEG PETR RESERVE,WASHINGTON,DC 20585, USA. NR 38 TC 3 Z9 4 U1 1 U2 3 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 SN 0887-0624 J9 ENERG FUEL JI Energy Fuels PD JUL-AUG PY 1991 VL 5 IS 4 BP 602 EP 608 DI 10.1021/ef00028a012 PG 7 WC Energy & Fuels; Engineering, Chemical SC Energy & Fuels; Engineering GA FY124 UT WOS:A1991FY12400012 ER PT J AU HIRST, E AF HIRST, E TI IMPROVING ENERGY EFFICIENCY IN THE USA - THE FEDERAL-ROLE SO ENERGY POLICY LA English DT Article DE POLICY; GOVERNMENT; EFFICIENCY AND CONSERVATION ID COST AB Energy efficiency in the USA improved dramatically between 1973-86. During the past two years, however, efficiency has stagnated. This is unfortunate because improving efficiency saves money for energy consumers, boosts economic productivity, reduces oil imports, and improves environmental quality. This paper discusses ways for the US Department of Energy to further improve US energy efficiency during the 1990s. Such efforts include: make a national commitment to energy efficiency; strengthen the Federal Energy Management Program; update programmes aimed at State and local governments; increase energy-efficiency research; work with utilities and State regulatory commissions to implement least-cost planning; strengthen energy-efficiency standards, and collect more data on energy-use and its determinants. RP HIRST, E (reprint author), OAK RIDGE NATL LAB,DIV ENERGY,OAK RIDGE,TN 37831, USA. NR 29 TC 1 Z9 1 U1 0 U2 2 PU BUTTERWORTH-HEINEMANN LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD, OXON, ENGLAND OX5 1GB SN 0301-4215 J9 ENERG POLICY JI Energy Policy PD JUL-AUG PY 1991 VL 19 IS 6 BP 567 EP 577 DI 10.1016/0301-4215(91)90036-N PG 11 WC Energy & Fuels; Environmental Sciences; Environmental Studies SC Energy & Fuels; Environmental Sciences & Ecology GA FX621 UT WOS:A1991FX62100006 ER PT J AU SCHIPPER, L MEYERS, S AF SCHIPPER, L MEYERS, S TI IMPROVING APPLIANCE EFFICIENCY IN INDONESIA SO ENERGY POLICY LA English DT Article DE EFFICIENCY; ELECTRICITY DEMAND; INDONESIA AB We report on findings from a study of household electricity consumption and the potential impact on future electricity demand of improving appliance efficiency in urban Java, Indonesia. We describe the current pattern of household electricity use in urban Java, based on results from a recent survey of 2 700 households, and the market for and characteristics of appliances currently sold in Indonesia. We estimate the impact on future electricity demand of two scenarios of penetration of higher efficiency. Finally, we discuss the barriers to improvement of appliance efficiency, and describe various policy approaches that the government could take in order to accelerate the adoption of higher-efficiency appliances. While in this article we focus our attention on Indonesia, many of the conclusions would apply to other developing countries as well. RP SCHIPPER, L (reprint author), UNIV CALIF BERKELEY LAWRENCE BERKELEY LAB,ENERGY ANAL PROGRAM,BERKELEY,CA 94720, USA. NR 12 TC 6 Z9 6 U1 0 U2 1 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 JUL-AUG PY 1991 VL 19 IS 6 BP 578 EP 588 DI 10.1016/0301-4215(91)90037-O PG 11 WC Energy & Fuels; Environmental Sciences; Environmental Studies SC Energy & Fuels; Environmental Sciences & Ecology GA FX621 UT WOS:A1991FX62100007 ER PT J AU BERRY, L SCHWEITZER, M AF BERRY, L SCHWEITZER, M TI RESIDENTIAL CONSERVATION PROGRAMS FOR THE ELDERLY - MARKETING TECHNIQUES AND ORGANIZATIONAL STRUCTURES SO ENERGY POLICY LA English DT Article DE ENERGY CONSERVATION; ELDERLY PEOPLE; CONSERVATION PROGRAMS AB Because the elderly tend not to respond to standard Residential Conservation Service (RCS) audit programmes, different programme structures and marketing approaches may be needed to serve the elderly segment adequately. The main purposes of this article are to describe the organizational features and marketing approaches that managers of energy conservation programmes targeted to the elderly have found to be effective, and to present the policy implications of these programme characteristics. RP BERRY, L (reprint author), OAK RIDGE NATL LAB,POB 2008,OAK RIDGE,TN 37831, USA. NR 14 TC 0 Z9 0 U1 0 U2 0 PU BUTTERWORTH-HEINEMANN LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD, OXON, ENGLAND OX5 1GB SN 0301-4215 J9 ENERG POLICY JI Energy Policy PD JUL-AUG PY 1991 VL 19 IS 6 BP 596 EP 605 DI 10.1016/0301-4215(91)90039-Q PG 10 WC Energy & Fuels; Environmental Sciences; Environmental Studies SC Energy & Fuels; Environmental Sciences & Ecology GA FX621 UT WOS:A1991FX62100009 ER PT J AU CRECELIUS, EA TREFRY, JH STEINHAUER, MS BOEHM, PD AF CRECELIUS, EA TREFRY, JH STEINHAUER, MS BOEHM, PD TI TRACE-METALS IN SEDIMENTS FROM THE INNER CONTINENTAL-SHELF OF THE WESTERN BEAUFORT SEA SO ENVIRONMENTAL GEOLOGY AND WATER SCIENCES LA English DT Article AB Increased development and changing climate have enhanced global interest in the Arctic Ocean and adjacent seas. Using a large, 3-yr data base, we have determined the distribution of trace metals in sediments from the inner shelf of the western Beaufort Sea. Metal concentrations in these sediments reflect pristine conditions, consistent with those for most coastal areas in the Arctic and with predictions based on average continental crust. Geographic variations in metal values are primarily related to sediment grain-size distribution. However, grain-size patterns are a complex function of several variables including source areas, ice and water movement, as well as physical and chemical weathering. Future identification of any metal contamination in Beaufort Sea sediments will be simplified by understanding the predictable natural patterns. C1 FLORIDA INST TECHNOL, DEPT OCEANOG & OCEAN ENGN, MELBOURNE, FL 32901 USA. BATTELLE OCEAN SCI, DUXBURY, MA 02332 USA. ARTHUR D LITTLE INC, CAMBRIDGE, MA 02140 USA. RP CRECELIUS, EA (reprint author), PACIFIC NW LAB, 439 W SEQUIM BAY RD, SEQUIM, WA 98382 USA. OI Trefry, John/0000-0002-8451-5524 NR 26 TC 8 Z9 8 U1 0 U2 5 PU SPRINGER VERLAG PI NEW YORK PA 175 FIFTH AVE, NEW YORK, NY 10010 SN 0177-5146 J9 ENVIRON GEOL WATER S PD JUL-AUG PY 1991 VL 18 IS 1 BP 71 EP 79 DI 10.1007/BF01704579 PG 9 WC Environmental Sciences; Geosciences, Multidisciplinary; Water Resources SC Environmental Sciences & Ecology; Geology; Water Resources GA FW552 UT WOS:A1991FW55200009 ER PT J AU BLACKWOOD, LG AF BLACKWOOD, LG TI ANALYZING CENSORED ENVIRONMENTAL DATA USING SURVIVAL ANALYSIS - SINGLE SAMPLE TECHNIQUES SO ENVIRONMENTAL MONITORING AND ASSESSMENT LA English DT Article AB The occurrence of censored data due to less than detectable measurements is a common problem with environmental data. The methods of survival analysis, although designed primarily for right censored data and time measured variables, can be adapted to apply censored environmental data. These methods have several theoretical and practical advantages over many existing techniques for dealing with less than detectable measurements. RP BLACKWOOD, LG (reprint author), EG&G IDAHO INC,IDAHO NATL ENGN LAB,POB 1625,IDAHO FALLS,ID 83415, USA. NR 0 TC 6 Z9 6 U1 1 U2 2 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 JUL PY 1991 VL 18 IS 1 BP 25 EP 40 PG 16 WC Environmental Sciences SC Environmental Sciences & Ecology GA GB666 UT WOS:A1991GB66600002 PM 24233643 ER PT J AU ELLSAESSER, HW AF ELLSAESSER, HW TI THE GLOBAL WARMING DEBATE SO ENVIRONMENTAL SCIENCE & TECHNOLOGY LA English DT Letter RP ELLSAESSER, HW (reprint author), UNIV CALIF LAWRENCE LIVERMORE NATL LAB,LIVERMORE,CA 94550, USA. NR 4 TC 0 Z9 0 U1 1 U2 1 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 SN 0013-936X J9 ENVIRON SCI TECHNOL JI Environ. Sci. Technol. PD JUL PY 1991 VL 25 IS 7 BP 1186 EP 1186 PG 1 WC Engineering, Environmental; Environmental Sciences SC Engineering; Environmental Sciences & Ecology GA FU945 UT WOS:A1991FU94500002 ER PT J AU SEED, TM KASPAR, LV LUNDBERG, D MARTIN, P GIOMETTI, CS AF SEED, TM KASPAR, LV LUNDBERG, D MARTIN, P GIOMETTI, CS TI CYTOGENETIC AND DIFFERENTIATIVE HEMATOPOIETIC PATTERNS DURING EARLY PHASES OF EVOLVING CHRONIC RADIATION-INDUCED MYELOPROLIFERATIVE DISEASE IN DOGS SO EXPERIMENTAL HEMATOLOGY LA English DT Meeting Abstract C1 ARGONNE NATL LAB,ARGONNE,IL 60439. NR 0 TC 0 Z9 0 U1 1 U2 1 PU CARDEN JENNINGS PUBL CO LTD PI CHARLOTTESVILLE PA BLAKE CTR, STE 200, 1224 W MAIN ST, CHARLOTTESVILLE, VA 22903 SN 0301-472X J9 EXP HEMATOL JI Exp. Hematol. PD JUL PY 1991 VL 19 IS 6 BP 535 EP 535 PG 1 WC Hematology; Medicine, Research & Experimental SC Hematology; Research & Experimental Medicine GA FQ310 UT WOS:A1991FQ31000294 ER PT J AU SMID, I CROESSMANN, CD WATSON, RD LINKE, J CARDELLA, A BOLT, H REHEIS, N KNY, E AF SMID, I CROESSMANN, CD WATSON, RD LINKE, J CARDELLA, A BOLT, H REHEIS, N KNY, E TI PERFORMANCE OF BRAZED GRAPHITE, CARBON-FIBER COMPOSITE, AND TZM MATERIALS FOR ACTIVELY COOLED STRUCTURES - QUALIFICATION TESTS SO FUSION TECHNOLOGY LA English DT Article DE BRAZED DIVERTOR TARGETS; HIGH HEAT FLUX TESTING; GRAPHITE REFRACTORY METAL JOINTS AB The divertor of a near-term fusion device has to withstand high heat fluxes, heat shocks, and erosion caused by the plasma. Furthermore, it has to be maintainable through remote techniques. Above all, a good heat removal capability across the interface (low-Z armor/heat sink) plus overall integrity after many operational cycles are needed. To meet all these requirements, an active metal brazing technique is applied to bond graphite and carbon-fiber composite materials to a heat sink consisting of a Mo-41Re coolant tube through a TZM body. Plain brazed graphite and TZM tiles are tested for their fusion-relevant properties. The interfaces appear undamaged after thermal cycling when the melting point of the braze joint is not exceeded and when the graphite armor is > 4 mm thick. High heat flux tests are performed on three actively cooled divertor targets. The braze joints show no sign of failure after exposure to thermal loads approximately 25% higher than the design value surface heat flux of 10 MW/m2. C1 SANDIA NATL LABS,ALBUQUERQUE,NM 87185. FORSCHUNGSZENTRUM JULICH GMBH,W-5170 JULICH,GERMANY. NET TEAM,W-8046 GARCHING,GERMANY. MET WERK PLANSEE GMBH,A-6600 REUTTE,AUSTRIA. RP SMID, I (reprint author), OSTERREICHISCHES FORSCHUNGSZENTRUM,A-2444 SEIBERSDORF,AUSTRIA. NR 7 TC 12 Z9 12 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 JUL PY 1991 VL 19 IS 4 BP 2035 EP 2040 PG 6 WC Nuclear Science & Technology SC Nuclear Science & Technology GA FR205 UT WOS:A1991FR20500003 ER PT J AU NYGREN, RE SMITH, MF AF NYGREN, RE SMITH, MF TI BERYLLIUM, AN ALTERNATIVE MATERIAL FOR PLASMA-FACING COMPONENTS SO FUSION TECHNOLOGY LA English DT Article DE BERYLLIUM; PLASMA SPRAY; DIVERTOR MATERIALS AB The promise of beryllium as a plasma-facing material in advanced fusion devices is discussed in the context of the design requirements for the International Thermonuclear Experimental Reactor (ITER). The properties of beryllium and the technology for plasma spraying of beryllium are summarized, and an overview of key issues and recommendations for the selection of plasma-facing armor are given. RP NYGREN, RE (reprint author), SANDIA NATL LABS,POB 5800,ALBUQUERQUE,NM 87185, USA. NR 11 TC 8 Z9 8 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 JUL PY 1991 VL 19 IS 4 BP 2092 EP 2097 PG 6 WC Nuclear Science & Technology SC Nuclear Science & Technology GA FR205 UT WOS:A1991FR20500010 ER PT J AU SAITO, A ABAD, JP WANG, D OHKI, M CANTOR, CR SMITH, CL AF SAITO, A ABAD, JP WANG, D OHKI, M CANTOR, CR SMITH, CL TI CONSTRUCTION AND CHARACTERIZATION OF A NOTI LINKING LIBRARY OF HUMAN CHROMOSOME-21 SO GENOMICS LA English DT Article ID SOMATIC-CELL GENETICS; BACTERIOPHAGE-LAMBDA; GEL-ELECTROPHORESIS; DNA METHYLATION; DELETION; EXPRESSION; SEPARATION; FRAGMENTS; SEQUENCES; ISLANDS C1 UNIV CALIF BERKELEY,DEPT MOLEC & CELLULAR BIOL,BERKELEY,CA 94720. NIIGATA UNIV,SCH MED,DEPT MED 2,NIIGATA 951,JAPAN. UNIV AUTONOMA MADRID,FAC CIENCIAS,CTR BIOL MOLEC,E-28049 MADRID,SPAIN. UNIV CALIF BERKELEY LAWRENCE BERKELEY LAB,CTR HUMAN GENOME,BERKELEY,CA 94720. SAITAMA CANC CTR,RES INST,DEPT IMMUNOL & VIROL,INA,SAITAMA 362,JAPAN. OI Smith, Cassandra/0000-0002-0346-8907 FU NCI NIH HHS [CA 38782] NR 44 TC 22 Z9 22 U1 0 U2 0 PU ACADEMIC PRESS INC JNL-COMP SUBSCRIPTIONS PI SAN DIEGO PA 525 B ST, STE 1900, SAN DIEGO, CA 92101-4495 SN 0888-7543 J9 GENOMICS JI Genomics PD JUL PY 1991 VL 10 IS 3 BP 618 EP 630 DI 10.1016/0888-7543(91)90444-J PG 13 WC Biotechnology & Applied Microbiology; Genetics & Heredity SC Biotechnology & Applied Microbiology; Genetics & Heredity GA FQ640 UT WOS:A1991FQ64000015 PM 1889809 ER PT J AU TONJES, RR WEITH, A RINCHIK, EM WINKING, H CARNWATH, JW KALINER, B PAUL, D AF TONJES, RR WEITH, A RINCHIK, EM WINKING, H CARNWATH, JW KALINER, B PAUL, D TI MICROCLONES DERIVED FROM THE MOUSE CHROMOSOME-7 D-E BANDS MAP WITHIN THE PROXIMAL REGION OF THE C14COS-DELETION IN ALBINO MUTANT MICE SO GENOMICS LA English DT Article ID MESSENGER-RNA; LOCUS REGION; DELETIONS; LIVER; CLONING; COMPLEX; GENES; DNA C1 FRAUNHOFER INST TOXICOL & AEROSOL RES,DEPT CELL BIOL,NIKOLAI FUCHS STR 1,W-3000 HANNOVER 61,GERMANY. GERMAN CANC RES CTR,W-6900 HEIDELBERG 1,GERMANY. OAK RIDGE NATL LAB,DIV BIOL,OAK RIDGE,TN 37830. LUBECK UNIV,SCH MED,INST BIOL,LUBECK,GERMANY. UNIV HAMBURG,SCH MED,INST PHARMACOL,W-2000 HAMBURG 13,GERMANY. NR 23 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 0888-7543 J9 GENOMICS JI Genomics PD JUL PY 1991 VL 10 IS 3 BP 686 EP 691 DI 10.1016/0888-7543(91)90453-L PG 6 WC Biotechnology & Applied Microbiology; Genetics & Heredity SC Biotechnology & Applied Microbiology; Genetics & Heredity GA FQ640 UT WOS:A1991FQ64000024 PM 1889814 ER PT J AU STALLINGS, RL FORD, AF NELSON, D TORNEY, DC HILDEBRAND, CE MOYZIS, RK AF STALLINGS, RL FORD, AF NELSON, D TORNEY, DC HILDEBRAND, CE MOYZIS, RK TI EVOLUTION AND DISTRIBUTION OF (GT)N REPETITIVE SEQUENCES IN MAMMALIAN GENOMES SO GENOMICS LA English DT Article ID FACTOR-I GENE; Z-DNA; CHROMOSOME-16; ORGANIZATION; EXPRESSION; LOCATIONS C1 UNIV CALIF LOS ALAMOS SCI LAB,CTR HUMAN GENOME STUDIES,LOS ALAMOS,NM 87545. UNIV CALIF LOS ALAMOS SCI LAB,DIV THEORET,LOS ALAMOS,NM 87545. RP STALLINGS, RL (reprint author), UNIV CALIF LOS ALAMOS SCI LAB,DIV LIFE SCI,MAIL STOP M886,LOS ALAMOS,NM 87545, USA. RI Stallings, Raymond/A-7213-2008 NR 18 TC 331 Z9 344 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 0888-7543 J9 GENOMICS JI Genomics PD JUL PY 1991 VL 10 IS 3 BP 807 EP 815 DI 10.1016/0888-7543(91)90467-S PG 9 WC Biotechnology & Applied Microbiology; Genetics & Heredity SC Biotechnology & Applied Microbiology; Genetics & Heredity GA FQ640 UT WOS:A1991FQ64000038 PM 1909685 ER PT J AU ANDERSON, GM CASTET, S SCHOTT, J MESMER, RE AF ANDERSON, GM CASTET, S SCHOTT, J MESMER, RE TI THE DENSITY MODEL FOR ESTIMATION OF THERMODYNAMIC PARAMETERS OF REACTIONS AT HIGH-TEMPERATURES AND PRESSURES SO GEOCHIMICA ET COSMOCHIMICA ACTA LA English DT Article ID PARTIAL MOLAL PROPERTIES; TRANSPORT-PROPERTIES; THEORETICAL PREDICTION; AQUEOUS-ELECTROLYTES; IONIZATION-CONSTANTS; 1ST IONIZATION; ION-PRODUCT; ACETIC-ACID; WATER; STANDARD AB Equations are presented for the calculation of the equilibrium constant and standard state thermodynamic properties at high temperatures and pressures of reactions involving both aqueous species and minerals, given a knowledge of the equilibrium constant and the standard enthalpy and heat capacity of the reactions at reference conditions. The equations are based on a model variation of the heat capacity of reaction which uses reference state values and solvent properties only, notably the temperature derivative of the coefficient of thermal expansion of water. C1 UNIV TOULOUSE 3,GEOCHIM LAB,CNRS,F-31062 TOULOUSE,FRANCE. OAK RIDGE NATL LAB,DIV CHEM,OAK RIDGE,TN 37831. RP ANDERSON, GM (reprint author), UNIV TORONTO,CTR EARTH SCI,DEPT GEOL,TORONTO M5S 3B1,ONTARIO,CANADA. OI Anderson, Gregor/0000-0001-8997-0633 NR 51 TC 113 Z9 113 U1 1 U2 24 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 JUL PY 1991 VL 55 IS 7 BP 1769 EP 1779 DI 10.1016/0016-7037(91)90022-W PG 11 WC Geochemistry & Geophysics SC Geochemistry & Geophysics GA FY221 UT WOS:A1991FY22100002 ER PT J AU MURRAY, RW TENBRINK, MRB GERLACH, DC RUSS, GP JONES, DL AF MURRAY, RW TENBRINK, MRB GERLACH, DC RUSS, GP JONES, DL TI RARE-EARTH, MAJOR, AND TRACE-ELEMENTS IN CHERT FROM THE FRANCISCAN COMPLEX AND MONTEREY GROUP, CALIFORNIA - ASSESSING REE SOURCES TO FINE-GRAINED MARINE-SEDIMENTS SO GEOCHIMICA ET COSMOCHIMICA ACTA LA English DT Article ID EAST PACIFIC RISE; NORTH-ATLANTIC OCEAN; METALLIFEROUS SEDIMENTS; DEPOSITIONAL-ENVIRONMENTS; PELAGIC SEDIMENTS; HYDROTHERMAL SEDIMENTS; GEOCHEMICAL STANDARDS; ACCUMULATION RATES; EQUATORIAL PACIFIC; SEAWATER AB Rare earth element (REE), major, and trace element analyses of 77 samples from the Mesozoic Franciscan Complex and Miocene Monterey Group of California (USA) indicate that magnitudes of the Ce anomaly (Ce/Ce*) and total REE abundances (SIGMA-REE) in these rocks are controlled dominantly by (a) the amount of included metalliferous material, (b) the amount of direct terrigenous input, and (c) the overall burial rate. The relative importance of these individual processes varies across an ocean basin in such a way that REE relative fractionations and SIGMA-REE correspond with its depositional environment. Our conclusions are supported by an extensive review of published REE data from various river, coastal, open-ocean, and ridge-influenced waters, as well as terrigenous, pelagic, and metalliferous sediment. The chert sequences record deposition in spreading ridge, open-ocean basin, and continental margin environments. The relative importance of metalliferous and terrigenous influences and the role of scavenging from seawater may be estimated from a sample's inferred depositional distance (km) from the spreading ridge, the major element chemistry, and the stratigraphic context. The Ce/Ce* values are low (approximately 0.29) in the vicinity of spreading ridges and trend to successively higher (approximately 1) values with decreasing metalliferous and increasing terrigenous influences. Other REE indicators (SIGMA-REE, Lu(n)/La(n), Eu/Eu*) also respond to metalliferous and terrigenous influences. Near the spreading ridge, chert SIGMA-REE appears determined by burial rate, while shale SIGMA-REE responds to metalliferous abundance. In open-ocean and continental margin environments, SIGMA-REE is controlled by sediment exposure time and therefore is related inversely to burial rate. REE data are consistent with the major elements Fe2O3, MnO, and Al2O3 in reflecting the respective metalliferous and terrigenous sources. P2O5 and CaO do not vary with Ce/Ce* in any environment, but CaO shows a weak negative correlation with SIGMA-REE. Trace element trends (e.g., V, Cr, Cu, Ge/Si, Rb, Sr, Y, Th, U) in general can similarly be accounted for in the context of depositional position relative to metalliferous and terrigenous inputs. REEs in chert appear less affected by post-depositional processes than either major or trace elements, indicating that REEs are better tools for paleoceanographic or tectonic reconstructions that are based on chert chemistry. This work complements recent efforts to elucidate the factors determining large-scale REE distributions in marine sediments and has direct bearing on previous attempts to use the Ce anomaly in older rocks and sediments as a recorder of secular variations and anoxic events in the overlying water column. C1 UNIV CALIF LAWRENCE LIVERMORE NATL LAB,DIV EARTH SCI,LIVERMORE,CA 94550. UNIV CALIF LAWRENCE LIVERMORE NATL LAB,DIV NUCL CHEM,LIVERMORE,CA 94550. RP MURRAY, RW (reprint author), UNIV CALIF BERKELEY,DEPT GEOL & GEOPHYS,BERKELEY,CA 94720, USA. NR 90 TC 173 Z9 299 U1 2 U2 32 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 JUL PY 1991 VL 55 IS 7 BP 1875 EP 1895 DI 10.1016/0016-7037(91)90030-9 PG 21 WC Geochemistry & Geophysics SC Geochemistry & Geophysics GA FY221 UT WOS:A1991FY22100010 ER PT J AU TAYLOR, SR MARSHALL, PD AF TAYLOR, SR MARSHALL, PD TI SPECTRAL DISCRIMINATION BETWEEN SOVIET EXPLOSIONS AND EARTHQUAKES USING SHORT-PERIOD ARRAY DATA SO GEOPHYSICAL JOURNAL INTERNATIONAL LA English DT Note DE DISCRIMINATION; EARTHQUAKE; EXPLOSION; SEISMIC ID WAVES AB Spectral ratio discriminants are applied to 61 presumed nuclear explosions, five large chemical explosions, and 44 earthquakes in the Soviet Union recorded at the four UK teleseismic arrays. The nuclear explosions were mainly from the Shagan test site (STS) and from peaceful nuclear explosions (PNE) ranging in magnitude from 4.2 to 6.2. The earthquakes were mostly located in the south-central Soviet Union and range in magnitude from 4.4 to 5.9. For each event/station pair, the P-wave spectrum is calculated out to 10 Hz using a 5 s window from the time-domain array beam and from a spectral stack. The spectral ratios from the array beam in the 0.5-1.0 Hz and 2.0-3.0 Hz frequency bands appear to give the best discrimination performance. At higher frequencies, reduced signal-to-noise ratios (particularly for the earthquakes) result in fewer measurements and increased scatter. In general, the explosions are characterized by the existence of more high-frequency energy than the shallow crustal earthquakes. A least-squares matrix factorization approach is used to separate out source and path effects. The separation of earthquakes and explosions is generally quite good down to magnitude 4.5 where the two populations merge because of signal-to-noise problems. The spectral values from the PNEs shows increased scatter relative to those from STS, presumably due to their wider range of emplacement conditions and geologic environment. Previous studies using regional phases indicate that NTS explosions are deficient in high frequencies relative to western US earthquakes. These contrasts in frequency content between NTS and STS explosions may be caused by differences in the near-source dynamic material response to the passage of the explosion shock wave or to depth-dependent effects of Q. C1 MINIST DEF,READING RG47 4RS,ENGLAND. RP TAYLOR, SR (reprint author), UNIV CALIF LAWRENCE LIVERMORE NATL LAB,DEPT EARTH SCI,LIVERMORE,CA 94550, USA. NR 11 TC 9 Z9 11 U1 0 U2 3 PU BLACKWELL SCIENCE LTD PI OXFORD PA OSNEY MEAD, OXFORD, OXON, ENGLAND OX2 0EL SN 0956-540X J9 GEOPHYS J INT JI Geophys. J. Int. PD JUL PY 1991 VL 106 IS 1 BP 265 EP 273 DI 10.1111/j.1365-246X.1991.tb04616.x PG 9 WC Geochemistry & Geophysics SC Geochemistry & Geophysics GA FV404 UT WOS:A1991FV40400021 ER PT J AU HIRSCH, LM SHANKLAND, TJ AF HIRSCH, LM SHANKLAND, TJ TI POINT-DEFECTS IN (MG,FE)SIO3 PEROVSKITE SO GEOPHYSICAL RESEARCH LETTERS LA English DT Article ID SILICATE PEROVSKITE; LOWER MANTLE; IRON AB Equilibrium concentrations of point defects in Fe-bearing MgSiO3 perovskite are calculated using a quantitative defect chemistry approach. Dependences of defect concentrations on temperature, oxygen activity, and pressure are illustrated. These calculations demonstrate how differences in the control of experimental conditions can lead to significant differences in point defect-controlled properties. C1 UNIV CALIF LOS ALAMOS SCI LAB,INST GEOPHYS & PLANETARY SCI,LOS ALAMOS,NM 87545. RP HIRSCH, LM (reprint author), UNIV CALIF LOS ALAMOS SCI LAB,GEOPHYS GRP,MS D447,LOS ALAMOS,NM 87545, USA. NR 20 TC 13 Z9 14 U1 0 U2 1 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 SN 0094-8276 J9 GEOPHYS RES LETT JI Geophys. Res. Lett. PD JUL PY 1991 VL 18 IS 7 BP 1305 EP 1308 DI 10.1029/91GL01582 PG 4 WC Geosciences, Multidisciplinary SC Geology GA FW155 UT WOS:A1991FW15500034 ER PT J AU HIRSCH, LM AF HIRSCH, LM TI THE FE-FEO BUFFER AT LOWER MANTLE PRESSURES AND TEMPERATURES SO GEOPHYSICAL RESEARCH LETTERS LA English DT Article ID SI-O; SYSTEM; IRON; COMPRESSION; PEROVSKITE; MIXTURES; STATE AB As a constraint on oxygen fugacity of the lower mantle, the iron-wustite (IW) oxygen buffer has been calculated for temperatures to 3000 K and pressures to 135 GPa using available thermochemical and thermophysical data for Fe, FeO, and O2. At conditions corresponding to the coremantle boundary and 670 km depth, respectively, the oxygen fugacity of this buffer is 10(20) and 10(3) Pa; oxygen activities referenced to these conditions are 10(-9) and 10(-13). C1 UNIV CALIF LOS ALAMOS SCI LAB,INST GEOPHYS & PLANETARY SCI,LOS ALAMOS,NM 87545. RP HIRSCH, LM (reprint author), UNIV CALIF LOS ALAMOS SCI LAB,GEOPHYS GRP,MS D447,LOS ALAMOS,NM 87545, USA. NR 33 TC 12 Z9 13 U1 0 U2 2 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 JUL PY 1991 VL 18 IS 7 BP 1309 EP 1312 DI 10.1029/91GL01583 PG 4 WC Geosciences, Multidisciplinary SC Geology GA FW155 UT WOS:A1991FW15500035 ER PT J AU NYQUIST, JE BLAIR, MS AF NYQUIST, JE BLAIR, MS TI A GEOPHYSICAL TRACKING AND DATA LOGGING SYSTEM - DESCRIPTION AND CASE-HISTORY SO GEOPHYSICS LA English DT Article AB Oak Ridge National Laboratory has developed an Ultrasonic Ranging and Data System (USRADS) and interfaced the system with a Geonics EM31 terrian conductivity meter. The system tracks the EM31 operator's position by measuring the traveltime of ultrasonic pulses from a transducer carried in a backpack, to microphones mounted on stationary receivers deployed in the survey area. A microprocessor-controlled radio transmitter, also carried in the backpack, transmits the terrain conductivity data to a mobile base station (van or truck), where the EM31's X-Y position, and the electromagnetic quadrature and in-phase readings are automatically recorded each second by a portable computer. USRADS can track the surveyor for distances of up to about 120 m from the base station with an accuracy of about 10 cm. USRADS potentially offers several advantages for surface geophysical surveys: (1) when elevations are not required, USRADS saves time and money because a measurement grid does not have to be surveyed before the geophysical work begins, (2) data are directly recorded by a portable computer and are available for analysis in the field, and (3) refining or expanding the coverage of an anomaly does not require additional surveying to add extra grid points. We discuss a field study where we surveyed roughly 8000 m2 of Solid Waste Storage Area 4 (SWSA 4) on the Oak Ridge Reservation collecting over 2700 in-phase and quadrature measurements in 45 minutes. The high density of measurements provided sharp resolution of waste trench boundaries. C1 CHEMRAD CORP,OAK RIDGE,TN 37830. RP NYQUIST, JE (reprint author), OAK RIDGE NATL LAB,POB 2008,OAK RIDGE,TN 37931, USA. RI Nyquist, Jonathan/B-2240-2010 NR 3 TC 10 Z9 10 U1 0 U2 2 PU SOC EXPLORATION GEOPHYSICISTS PI TULSA PA 8801 S YALE ST, TULSA, OK 74137 SN 0016-8033 J9 GEOPHYSICS JI Geophysics PD JUL PY 1991 VL 56 IS 7 BP 1114 EP 1121 DI 10.1190/1.1443123 PG 8 WC Geochemistry & Geophysics SC Geochemistry & Geophysics GA FW153 UT WOS:A1991FW15300024 ER PT J AU ANDERSON, LE AF ANDERSON, LE TI ELF - EXPOSURE LEVELS, BIOEFFECTS, AND EPIDEMIOLOGY SO HEALTH PHYSICS LA English DT Article ID 60-HZ ELECTRIC-FIELDS; SINGLE-STRAND BREAKS; MAMMALIAN-CELLS; MAGNETIC-FIELDS; REPAIR; GROWTH; CANCER; RATS AB Considerable information has been obtained within the last decade describing biological effects, both real and potential, of extremely low frequency (ELF) electric and magnetic fields. Additionally, advances have also been made in defining the interactions between such fields and living systems. Many of the current studies concerning ELF electromagnetic fields are focused on understanding the mechanisms of interaction and in elucidating the issues of human health impact. This paper provides an overview of recent progress in ELF research including work on dosimetry of the fields, laboratory animal studies, cellular research, and epidemiology. RP ANDERSON, LE (reprint author), PACIFIC NW LAB, POB 999, RICHLAND, WA 99352 USA. NR 26 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 JUL PY 1991 VL 61 IS 1 BP 41 EP 46 DI 10.1097/00004032-199107000-00004 PG 6 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 FW001 UT WOS:A1991FW00100005 PM 2061048 ER PT J AU WIGGS, LD COXDEVORE, CA VOELZ, GL AF WIGGS, LD COXDEVORE, CA VOELZ, GL TI MORTALITY AMONG A COHORT OF WORKERS MONITORED FOR PO-210 EXPOSURE - 1944-1972 SO HEALTH PHYSICS LA English DT Article AB This study represents the largest epidemiologic investigation of humans exposed to the radionuclide Po-210. In a cohort of 4402 white males employed by the Mound Facility, during the period when Po operations were conducted (1944-1972), no excess mortality was observed. Among workers initially hired during World War II, mortality was elevated, especially for deaths from all cancers, cancers of the lung, and cancers of the rectum. These adverse health events do not appear related to exposure to Po-210. Among workers monitored for Po-210, mortality was significantly less than expected, although more lung cancers were observed than expected. No significant dose-response trends were identified for all causes combined, all cancers combined, or for cause-specific cancers among the Po-monitored subcohort. Continued follow-up of this cohort is planned. RP WIGGS, LD (reprint author), UNIV CALIF LOS ALAMOS SCI LAB, EPIDEMIOL SECT, OCCUPAT MED GRP, MS-K404, POB 1663, LOS ALAMOS, NM 87545 USA. NR 16 TC 22 Z9 23 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 JUL PY 1991 VL 61 IS 1 BP 71 EP 76 DI 10.1097/00004032-199107000-00007 PG 6 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 FW001 UT WOS:A1991FW00100008 PM 2061051 ER PT J AU ANSPAUGH, LR AF ANSPAUGH, LR TI LETS ALL PLAY BY THE SAME RULES - REPLY SO HEALTH PHYSICS LA English DT Letter RP ANSPAUGH, LR (reprint author), UNIV CALIF LAWRENCE LIVERMORE NATL LAB, DIV ENVIRONM SCI, POB 5507, L-453, LIVERMORE, CA 94550 USA. NR 18 TC 1 Z9 1 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 JUL PY 1991 VL 61 IS 1 BP 143 EP 145 PG 3 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 FW001 UT WOS:A1991FW00100018 PM 2061042 ER PT J AU MARSEILLE, TJ SCHLIESING, JS BELL, DM JOHNSON, BM AF MARSEILLE, TJ SCHLIESING, JS BELL, DM JOHNSON, BM TI EXTENDING COOLING-TOWER THERMAL PERFORMANCE PREDICTION USING A LIQUID-SIDE FILM RESISTANCE MODEL SO HEAT TRANSFER ENGINEERING LA English DT Article AB Current models used to analyze the thermal performance of cooling towers assume that the air/water interfacial temperature is equivalent to the bulk temperature of the water, or, in other words, that the liquid-side film resistance is negligible. This assumption is a possible source of the dependence on inlet hot water temperatures found in cooling tower packing heat and mass transfer correlations derived from these models. For applications in which the water temperatures exceed the limits of experimental data used in developing such correlations, a resulting high level of uncertainty exists. This article describes a method by which one-dimensional cooling tower model equations can be corrected to account for liquid-side film resistance. The use of these corrected equations in the development of temperature-independent heat and mass transfer correlations for tower packings is also described. RP MARSEILLE, TJ (reprint author), PACIFIC NW LAB, DEPT ENERGY SCI, RICHLAND, WA 99352 USA. NR 0 TC 13 Z9 13 U1 0 U2 0 PU HEMISPHERE PUBL CORP PI BRISTOL PA 1900 FROST ROAD, SUITE 101, BRISTOL, PA 19007-1598 SN 0145-7632 J9 HEAT TRANSFER ENG JI Heat Transf. Eng. PD JUL-SEP PY 1991 VL 12 IS 3 BP 19 EP 30 DI 10.1080/01457639108939753 PG 12 WC Thermodynamics; Engineering, Mechanical; Mechanics SC Thermodynamics; Engineering; Mechanics GA GC134 UT WOS:A1991GC13400002 ER PT J AU FRANCO, B LAI, LW PATTERSON, D LEDBETTER, DH TRASK, BJ VANDENENGH, G IANNACCONE, S FRANCES, S PATEL, PI LUPSKI, JR AF FRANCO, B LAI, LW PATTERSON, D LEDBETTER, DH TRASK, BJ VANDENENGH, G IANNACCONE, S FRANCES, S PATEL, PI LUPSKI, JR TI MOLECULAR CHARACTERIZATION OF A PATIENT WITH DEL(1)(Q23-Q25) SO HUMAN GENETICS LA English DT Article ID MARIE-TOOTH NEUROPATHY; INTERSTITIAL DELETION; HIGH-RESOLUTION; DUFFY LOCUS; LONG ARM; SENSORY NEUROPATHY; HEREDITARY MOTOR; GENETIC-LINKAGE; HUMAN GENOME; CHROMOSOME-1 AB We report a patient (S.T.) with multiple congenital anomalies and developmental delay associated with an interstitial deletion of 1q23-1q25. Molecular analysis of the deletion was performed using DNA markers that map to 1q. Five DNA markers, MLAJ-1 (D1S61), CRI-L1054 (D1S42), HB140 (D1S66), OS-6 (D1S75), and BH516 (D1S110), were demonstrated to be deleted. Informative polymorphisms demonstrated this to be a de novo deletion of the maternally derived chromosome. Deletion status was determined using restriction fragment length polymorphism (RFLP) analysis supplemented with densitometry in the experiments where RFLP analysis was not fully informative. Deletions were confirmed by Southern analysis using genomic DNA from a somatic cell hybrid retaining the del(1)(q23-q25) chromosome that was constructed from patient S.T. Flow karyotyping confirmed the deletion and estimated that the deletion encompassed 11,000- 16,000 kb. The clinical and cytogenetic characteristics of S.T. are compared with those of ten previously described patients with monosomy 1q2l-1q25. C1 BAYLOR UNIV,INST MOLEC GENET,ONE BAYLOR PLAZA,ROOM T-905,HOUSTON,TX 77030. BAYLOR UNIV,DEPT PEDIAT,HOUSTON,TX 77030. UNIV CALIF LAWRENCE LIVERMORE NATL LAB,DIV BIOMED SCI,LIVERMORE,CA 94550. ELEANOR ROOSEVELT INST,DENVER,CO 80206. TEXAS SCOTTISH RITE HOSP CRIPPLED CHILDREN,DALLAS,TX 75219. OI FRANCO, Brunella/0000-0001-5588-4569 FU NICHD NIH HHS [HD 24064-02, HD-17665]; NINDS NIH HHS [R01 NS-27042] NR 54 TC 29 Z9 29 U1 0 U2 0 PU SPRINGER VERLAG PI NEW YORK PA 175 FIFTH AVE, NEW YORK, NY 10010 SN 0340-6717 J9 HUM GENET JI Hum. Genet. PD JUL PY 1991 VL 87 IS 3 BP 269 EP 277 PG 9 WC Genetics & Heredity SC Genetics & Heredity GA FY516 UT WOS:A1991FY51600005 PM 1677922 ER PT J AU MARLEY, NA GAFFNEY, JS ORLANDINI, KA DUGUE, CP AF MARLEY, NA GAFFNEY, JS ORLANDINI, KA DUGUE, CP TI AN EVALUATION OF AN AUTOMATED HOLLOW-FIBER ULTRAFILTRATION APPARATUS FOR THE ISOLATION OF COLLOIDAL MATERIALS IN NATURAL-WATERS SO HYDROLOGICAL PROCESSES LA English DT Article DE ULTRAFILTRATION OF GROUNDWATER; COLLOIDAL AND MACROMOLECULAR SAMPLING METHODS; AUTOMATED GROUNDWATER SAMPLING SYSTEM; HUMIC AND FULVIC ACID SAMPLER AB Colloidal materials and macromolecules that are less than 0.45 microns in diameter can act to transport both hydrophobic and hydrophilic contaminations in subsurface waters. An automated hollow-fibre ultrafiltration apparatus is described and evaluated regarding its ability to physically size and isolate colloidal materials from natural waters. Sufficient size-fractionated colloidal samples can be obtained from 60 litre samples to perform inorganic, organic, and radionuclide characterizations, as well as allow the binding capacities of humic and fulvic materials to be evaluated. Samples processed in the field with the automated system were compared with laboratory analyses using single cartridge hollow-fibre ultrafilters and found to agree well with each other. Typical sample reproducibilities were with 15 per cent. The results indicate that field collection of colloidal materials is feasible with minimal sample perturbation using the automated sampler. C1 IIT,ENVIRONM ENGN,CHICAGO,IL 60616. RP MARLEY, NA (reprint author), ARGONNE NATL LAB,DIV ENVIRONM RES,ARGONNE,IL 60439, USA. NR 0 TC 8 Z9 8 U1 2 U2 2 PU JOHN WILEY & SONS LTD PI W SUSSEX PA BAFFINS LANE CHICHESTER, W SUSSEX, ENGLAND PO19 1UD SN 0885-6087 J9 HYDROL PROCESS JI Hydrol. Process. PD JUL-SEP PY 1991 VL 5 IS 3 BP 291 EP 299 DI 10.1002/hyp.3360050309 PG 9 WC Water Resources SC Water Resources GA GA610 UT WOS:A1991GA61000008 ER PT J AU MOYER, BA BALTICH, FJ ANDREWS, KC AF MOYER, BA BALTICH, FJ ANDREWS, KC TI INTERFACIAL PRECIPITATES CONTAINING DODECAMOLYBDOPHOSPHATE AND DODECAMOLYBDOARSENATE ANIONS IN TERTIARY AMINE SOLVENT-EXTRACTION SO HYDROMETALLURGY LA English DT Note ID PHASE AB Interfacial precipitates from the strip settler of a uranium mill employing tertiary amine solvent extraction were analyzed by X-ray fluorescence, X-ray powder diffraction, FTIR spectrophotometry, and elemental analysis. It was revealed that the major solid component is a double salt having the composition (R3NH)3[alpha-XM(o)12O40].3(R3NH)Cl, where X = P or As and R = n-octyl or n-decyl. Knowledge of the nature of the interfacial precipitates explained the deteriorating performance of the solvent extraction circuit and assisted in the development of successful measures to control the problem and resume normal operation. C1 CHEVRON RESOURCES CO,HOBSON,TX. RP MOYER, BA (reprint author), OAK RIDGE NATL LAB,DIV PLANT PATHOL,OAK RIDGE,TN 37831, USA. RI Solominow, Sonia/A-4021-2008; Moyer, Bruce/L-2744-2016 OI Moyer, Bruce/0000-0001-7484-6277 NR 13 TC 2 Z9 2 U1 0 U2 1 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0304-386X J9 HYDROMETALLURGY JI Hydrometallurgy PD JUL PY 1991 VL 27 IS 1 BP 113 EP 122 DI 10.1016/0304-386X(91)90082-W PG 10 WC Metallurgy & Metallurgical Engineering SC Metallurgy & Metallurgical Engineering GA FT008 UT WOS:A1991FT00800010 ER PT J AU MORSE, JD MARIELLA, RP ANDERSON, GD DUTTON, RW AF MORSE, JD MARIELLA, RP ANDERSON, GD DUTTON, RW TI PICOSECOND OPTOELECTRONIC GATING OF SILICON BIPOLAR-TRANSISTORS BY LOCALLY INTEGRATED GAAS PHOTOCONDUCTIVE DEVICES SO IEEE ELECTRON DEVICE LETTERS LA English DT Article ID VLSI AB Integration of picosecond GaAs photoconductive devices with silicon bipolar transistors to provide a high-performance optoelectronic gating element is demonstrated. GaAs photoconductive circuit elements (PCE's) with approximately 15-ps FWHM photocurrent transient responses have been integrated in base-drive circuit configurations. Results have demonstrated that approximately 70-ps FWHM pulses of > 1 mA (5 V switching across 5 k-OMEGA) are possible using approximately 3-4 pJ of optical input at 820 nm. Furthermore, for the silicon bipolar transistor process which has a nominal f(t) > 10 GHz, gating pulses with approximately 50-ps rise times, limited by the input optical pulse, have been observed. C1 STANFORD UNIV,CTR INTEGRATED SYST,STANFORD,CA 94305. RP MORSE, JD (reprint author), UNIV CALIF LAWRENCE LIVERMORE NATL LAB,OPT ELECTR & DEVICES GRP,LIVERMORE,CA 94550, USA. NR 7 TC 2 Z9 2 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 0741-3106 J9 IEEE ELECTR DEVICE L JI IEEE Electron Device Lett. PD JUL PY 1991 VL 12 IS 7 BP 379 EP 381 DI 10.1109/55.103613 PG 3 WC Engineering, Electrical & Electronic SC Engineering GA FT653 UT WOS:A1991FT65300008 ER PT J AU LEE, SM CHUANG, SL BRYAN, RP ZMUDZINSKI, CA COLEMAN, JJ AF LEE, SM CHUANG, SL BRYAN, RP ZMUDZINSKI, CA COLEMAN, JJ TI A SELF-CONSISTENT MODEL OF A NONPLANAR QUANTUM-WELL PERIODIC LASER ARRAY SO IEEE JOURNAL OF QUANTUM ELECTRONICS LA English DT Article ID DIMENSIONAL DEVICE SIMULATOR; TWIN-STRIPE LASERS; NUMERICAL-SOLUTION; OPTICAL GAIN; THRESHOLD; GAAS; DIFFUSION; LAYERS AB An analysis of a nonplanar semiconductor periodic laser array is carried out using a self-consistent model, which explains successfully the experimentally observed efficiencies and output optical patterns. Our model takes into account the two-dimensional injected current distribution coupled with the optical intensity profile and gain variation from the mesa to the groove. The optical field distribution of the nonplanar laser array is treated as a linear combination of the optical modes in the mesas, the grooves, and the bends using the effective index method. Our numerical results show the multimode operation due to spatial hole burning, the near-field patterns affected by the nonuniform current injection, and the competition of available carriers among the modes of neighboring waveguides. The aluminum mole fraction on the cladding layers affects both the carrier and optical confinements of the modes; therefore, it controls the coupling of modes in neighboring waveguides and output radiation patterns. C1 UNIV ILLINOIS,DEPT ELECT & COMP ENGN,URBANA,IL 61801. UNIV ILLINOIS,COMPOUND SEMICOND MICROELECTR LAB,URBANA,IL 61801. SANDIA NATL LABS,ALBUQUERQUE,NM 87185. RP LEE, SM (reprint author), EMORY UNIV,DEPT PHYS,ATLANTA,GA 30322, USA. RI Coleman, James/C-9703-2011 NR 43 TC 1 Z9 1 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 0018-9197 J9 IEEE J QUANTUM ELECT JI IEEE J. Quantum Electron. PD JUL PY 1991 VL 27 IS 7 BP 1886 EP 1899 DI 10.1109/3.83391 PG 14 WC Engineering, Electrical & Electronic; Optics; Physics, Applied SC Engineering; Optics; Physics GA GB771 UT WOS:A1991GB77100006 ER PT J AU ZHOU, P CHENG, J SCHAUS, CF SUN, SZ ZHENG, K ARMOUR, E HAINS, C HSIN, W MYERS, DR VAWTER, GA AF ZHOU, P CHENG, J SCHAUS, CF SUN, SZ ZHENG, K ARMOUR, E HAINS, C HSIN, W MYERS, DR VAWTER, GA TI LOW SERIES RESISTANCE HIGH-EFFICIENCY GAAS ALGAAS VERTICAL-CAVITY SURFACE-EMITTING LASERS WITH CONTINUOUSLY GRADED MIRRORS GROWN BY MOCVD SO IEEE PHOTONICS TECHNOLOGY LETTERS LA English DT Article AB GaAs/AlGaAs vertical-cavity top-surface-emitting lasers with a continuously graded mirror composition have been grown by MOCVD, and planar devices with proton-implant current confinement have been characterized. Continuous grading of the heterointerfaces in the Bragg reflectors eliminated the energy-band discontinuities, thus improving carrier transport and resulting in a substantial reduction in the series resistance and threshold voltage of the laser diodes. These VCSEL's have excellent room-temperature CW electrical characteristics, including some of the lowest series resistance, highest power efficiency, and lowest operating voltages ever reported. C1 SANDIA NATL LABS,ALBUQUERQUE,NM 87185. RP ZHOU, P (reprint author), UNIV NEW MEXICO,CTR HIGH TECHNOL MAT,ALBUQUERQUE,NM 87131, USA. NR 12 TC 70 Z9 70 U1 1 U2 9 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 JUL PY 1991 VL 3 IS 7 BP 591 EP 593 DI 10.1109/68.87923 PG 3 WC Engineering, Electrical & Electronic; Optics; Physics, Applied SC Engineering; Optics; Physics GA GA189 UT WOS:A1991GA18900003 ER PT J AU HARFOUSH, FA TAFLOVE, A AF HARFOUSH, FA TAFLOVE, A TI SCATTERING OF ELECTROMAGNETIC-WAVES BY A MATERIAL HALF-SPACE WITH A TIME-VARYING CONDUCTIVITY SO IEEE TRANSACTIONS ON ANTENNAS AND PROPAGATION LA English DT Article AB This paper analyzes for the first time electromagnetic wave penetration and scattering interactions for a material half-space having sinusoidally time-varying conductivity. Two limiting cases are considered. The first assumes that the material conductivity is almost a constant with a small temporal perturbation. The problem is accordingly attacked with first-order perturbation methods. The second exploits a large dimensionless parameter and yields an asymptotic expansion of the field inside a highly conducting material undergoing sinusoidal time variation. Illustrative examples are given which agree well with numerically obtained finite-difference time-domain (FDTD) results. C1 NORTHWESTERN UNIV,INST TECHNOL,DEPT ELECT ENGN & COMP SCI,EVANSTON,IL 60208. RP HARFOUSH, FA (reprint author), FERMI NATL ACCELERATOR LAB,MS 345,POB 500,BATAVIA,IL 60510, USA. RI Taflove, Allen/B-7275-2009 NR 12 TC 17 Z9 17 U1 0 U2 1 PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017-2394 SN 0018-926X J9 IEEE T ANTENN PROPAG JI IEEE Trans. Antennas Propag. PD JUL PY 1991 VL 39 IS 7 BP 898 EP 906 DI 10.1109/8.86907 PG 9 WC Engineering, Electrical & Electronic; Telecommunications SC Engineering; Telecommunications GA FZ277 UT WOS:A1991FZ27700004 ER PT J AU HIVELY, LM CONDIT, WC AF HIVELY, LM CONDIT, WC TI ELECTROMECHANICAL RAILGUN MODEL SO IEEE TRANSACTIONS ON MAGNETICS LA English DT Article ID FUSION AB The electromechanical aspects of railgun motion are modeled analytically. A Lagrangian formulation is used to obtain the force and circuit equations, which are then solved for energy conservation and resistive flux decay. The resulting integral equation is solved for the barrel length as a measure of the launcher size and cost. C1 UNIV CALIF LOS ALAMOS SCI LAB,LOS ALAMOS,NM 87545. RP HIVELY, LM (reprint author), MARTIN MARIETTA ENERGY SYST INC,OAK RIDGE NATL LAB,DIV APPL TECHNOL,OAK RIDGE,TN 37831, USA. NR 13 TC 2 Z9 2 U1 1 U2 1 PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017-2394 SN 0018-9464 J9 IEEE T MAGN JI IEEE Trans. Magn. PD JUL PY 1991 VL 27 IS 4 BP 3731 EP 3734 DI 10.1109/20.102944 PG 4 WC Engineering, Electrical & Electronic; Physics, Applied SC Engineering; Physics GA GP593 UT WOS:A1991GP59300024 ER PT J AU KRUSE, VJ NICKEL, DL TAYLOR, ER BONK, JJ BARNES, PR AF KRUSE, VJ NICKEL, DL TAYLOR, ER BONK, JJ BARNES, PR TI IMPACTS OF A NOMINAL NUCLEAR ELECTROMAGNETIC PULSE ON ELECTRIC-POWER SYSTEMS - A PROBABILISTIC APPROACH SO IEEE TRANSACTIONS ON POWER DELIVERY LA English DT Article DE ELECTRIC POWER SYSTEM; EMP; ELECTROMAGNETIC PULSE; HEMP; MHD-EMP; DOE EMP RESEARCH PROGRAM; EMP ASSESSMENTS ID EXPLOSIONS; HEMP; LINE AB A high-altitude nuclear detonation several hundred kilometers above the central United States will subject much of the nation to an electromagnetic pulse (EMP) consisting of intense steep-front short-duration transient electromagnetic fields followed by a geomagnetic disturbance with a duration of tens of seconds. Since 1983, the Department of Energy has been actively pursuing a research program to assess the potential impacts of one or more EMP events on the nation's electric energy supply. A nominal EMP environment suitable for assessing geographically large systems has been used to provide an indication of EMP impacts on electric power systems. It was found that a single high-altitude burst, which significantly disturbs the geomagnetic field, could cause significant load and generation loss, but permanent damage would be isolated. Multiple bursts would increase the disturbance. Nevertheless, based on the effects of a nominal EMP environment, a long term blackout is not expected since major components such as power transformers are not likely to be damaged. C1 OAK RIDGE NATL LAB,OAK RIDGE,TN 37831. RP KRUSE, VJ (reprint author), ABB POWER SYST INC,777 PENN CTR BLVD,PITTSBURGH,PA 15235, USA. NR 41 TC 0 Z9 0 U1 1 U2 1 PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017-2394 SN 0885-8977 J9 IEEE T POWER DELIVER JI IEEE Trans. Power Deliv. PD JUL PY 1991 VL 6 IS 3 BP 1251 EP 1263 DI 10.1109/61.85874 PG 13 WC Engineering, Electrical & Electronic SC Engineering GA FT325 UT WOS:A1991FT32500045 ER PT J AU SHEN, DX LITTLEJOHN, D CHANG, SG AF SHEN, DX LITTLEJOHN, D CHANG, SG TI EFFECT OF SIMPLE ANIONS AND METAL-IONS ON THE HYDROLYSIS OF DISULFATE ION SO INDUSTRIAL & ENGINEERING CHEMISTRY RESEARCH LA English DT Article AB The influence of anions and cations commonly found in flue gas scrubber systems on the hydrolysis rate of disulfate ion (S2O7(2-)) has been studied. The cations studied include Na+, K+, Ca2+, Mg2+, and Mn2+. The anions studied include SO3(2-), SO4(2-), S2O3(2-), S2O6(2-), HSO3-, Cl-, H2PO4-, and HPO4(2-). Of the ions studied, Ca2+, Mg2+, SO3(2-), and S2O6(2-) were found to approximately double the rate of S2O7(2-) hydrolysis. Adipic acid was found to have no effect on S2O7(2-) hydrolysis. Activation energies for the S2O7(2-) hydrolysis rate accelerated by Ca2+, Mg2+, and SO3(2-), as well as for the unenhanced rate, were found to be in the range of 9-12 kcal/mol. C1 UNIV CALIF BERKELEY LAWRENCE BERKELEY LAB,DIV APPL SCI,BERKELEY,CA 94720. NR 10 TC 0 Z9 0 U1 0 U2 0 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 SN 0888-5885 J9 IND ENG CHEM RES JI Ind. Eng. Chem. Res. PD JUL PY 1991 VL 30 IS 7 BP 1434 EP 1437 DI 10.1021/ie00055a005 PG 4 WC Engineering, Chemical SC Engineering GA FW315 UT WOS:A1991FW31500005 ER PT J AU SOLANKI, RS SOUTHWORTH, F AF SOLANKI, RS SOUTHWORTH, F TI AN EXECUTION PLANNING ALGORITHM FOR MILITARY AIRLIFT SO INTERFACES LA English DT Article DE MILITARY; LOGISTICS TRANSPORTATION; ROUTE SELECTION ID SCHEDULING PROBLEMS; TIME AB Execution planning at the military airlift command of the US Air Force involves updating the routes and schedules of aircraft to reflect changing requirements for moving freight and personnel and changing airlift resources. The problem can be characterized as a pickup and delivery problem with time windows and node capacities. The constraints on the capacities of the nodes (airfields) limit the rate at which the aircraft can be serviced and the amount of requirements (tonnage of cargo, number of passengers) that can be loaded and unloaded at an airfield per day. The execution planning algorithm described can be used daily to modify the existing airlift operations plan. An algorithm based on the insertion heuristic was selected for implementation due to its computational feasibility and its capability to absorb complex constraints arising in the execution planning problem. The insertion heuristic has the additional desirable feature of keeping intact as much of the existing schedule as possible. RP SOLANKI, RS (reprint author), OAK RIDGE NATL LAB,POB 2008,OAK RIDGE,TN 37831, USA. NR 5 TC 16 Z9 16 U1 0 U2 2 PU INST OPERATIONS RESEARCH MANAGEMENT SCIENCES PI LINTHICUM HTS PA 901 ELKRIDGE LANDING RD, STE 400, LINTHICUM HTS, MD 21090-2909 SN 0092-2102 J9 INTERFACES JI Interfaces PD JUL-AUG PY 1991 VL 21 IS 4 BP 121 EP 131 DI 10.1287/inte.21.4.121 PG 11 WC Management; Operations Research & Management Science SC Business & Economics; Operations Research & Management Science GA GC627 UT WOS:A1991GC62700011 ER PT J AU CHANG, SL LYCZKOWSKI, RW BERRY, GF AF CHANG, SL LYCZKOWSKI, RW BERRY, GF TI SPECTRAL DYNAMICS OF COMPUTER-SIMULATED, 2-DIMENSIONAL, FEW-TUBE FLUIDIZED-BED COMBUSTORS SO INTERNATIONAL JOURNAL OF HEAT AND MASS TRANSFER LA English DT Article AB Argonne National Laboratory has developed methods for investigating erosion phenomena in fluid/solids systems by integrating a state-of-the-art, two-phase, two-dimensional, hydrodynamic computer model (FLUFIX, which computes temporal and spatial distributions) with erosion models that correlate the computed hydrodynamic properties with erosion patterns and rates. In this paper, a spectral analysis correlating the porosity, pressure, and velocity of a generic, few-tube, fluidized-bed combuster in time and space is reported. The major frequencies of porosity, pressure, and velocity oscillations are 0.7-4 Hz. Porosity and pressure oscillations traveled in the combustor at speeds of 0.4-1 m s-1. Pressure oscillations are well correlated with the lagging porosity oscillations. RP CHANG, SL (reprint author), ARGONNE NATL LAB,DIV ENERGY SYST,9700 S CASS AVE,ARGONNE,IL 60439, USA. NR 15 TC 3 Z9 3 U1 0 U2 0 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD, ENGLAND OX5 1GB SN 0017-9310 J9 INT J HEAT MASS TRAN JI Int. J. Heat Mass Transf. PD JUL PY 1991 VL 34 IS 7 BP 1773 EP 1781 DI 10.1016/0017-9310(91)90152-5 PG 9 WC Thermodynamics; Engineering, Mechanical; Mechanics SC Thermodynamics; Engineering; Mechanics GA FT896 UT WOS:A1991FT89600016 ER PT J AU MARTEL, SJ PETERSON, JE AF MARTEL, SJ PETERSON, JE TI INTERDISCIPLINARY CHARACTERIZATION OF FRACTURE SYSTEMS AT THE UNITED-STATES BK SITE, GRIMSEL-LABORATORY, SWITZERLAND SO INTERNATIONAL JOURNAL OF ROCK MECHANICS AND MINING SCIENCES & GEOMECHANICS ABSTRACTS LA English DT Article ID SLIP-FAULT ZONES; MOUNT ABBOT QUADRANGLE; GRANITIC ROCK; SIERRA-NEVADA; STRIKE; DEFORMATION; EXAMPLE; NUCLEATION; CALIFORNIA; GROWTH AB We have implemented a characterization methodology for fractured rock sites that combines geophysical and geologic information to aid hydrologic modelling. This approach concentrates on fracture zones, which commonly dominate the hydrologic behaviour of large rock masses. This approach contrasts with approaches that focus on individual fractures and are largely statistically-based. The general philosophy is to identify and locate the major fracture zones, and then establish the essential and recurring patterns in which fractures are organized with the zones. We make a concerted effort to use this information on fracture systematics to link site-specific geologic and geophysical information. The procedure generally is applied to a specific site in a four-step sequence. First, information on the region encompassing the site is assembled and a model of the geologic structure in the vicinity of the target site is prepared. The major structures that might intersect the site are identified in this stage. Second, detailed geologic mapping is conducted to define the structural systematics of the major fracture zones near the site and to gain insight into how fluid might flow along the zones. Third, a preliminary model of the major structures at the site is prepared using the regional information together with geologic mapping and borehole surveys along the target site perimeter. Finally, the model is refined based on geophysical techniques [such as vertical seismic profiling (VSP) and geophysical tomography] that can image a rock mass at distances of at least several tens of metres from a borehole. Results to date from the US/BK site at the Grimsel Rock Laboratory in Switzerland indicate that this approach can contribute significantly to the hydrologic evaluation of a fractured rock mass. RP MARTEL, SJ (reprint author), UNIV CALIF BERKELEY LAWRENCE BERKELEY LAB,DIV EARTH SCI,BERKELEY,CA 94720, USA. NR 52 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 0148-9062 J9 INT J ROCK MECH MIN JI Int. J. Rock Mech. Min. Sci. PD JUL PY 1991 VL 28 IS 4 BP 295 EP 323 DI 10.1016/0148-9062(91)90596-E PG 29 WC Engineering, Geological; Mining & Mineral Processing SC Engineering; Mining & Mineral Processing GA GA570 UT WOS:A1991GA57000006 ER PT J AU ZIMMERMAN, RW KUMAR, S BODVARSSON, GS AF ZIMMERMAN, RW KUMAR, S BODVARSSON, GS TI LUBRICATION THEORY ANALYSIS OF THE PERMEABILITY OF ROUGH-WALLED FRACTURES SO INTERNATIONAL JOURNAL OF ROCK MECHANICS AND MINING SCIENCES & GEOMECHANICS ABSTRACTS LA English DT Article ID SINGLE FRACTURE; TRACER TESTS; FLOW; FLUID AB Lubrication theory is used to study the permeability of rough-walled rock fractures. In this approximation, which is valid for low Reynolds numbers and under certain restrictions on the magnitude of the roughness, the Navier-Stokes equations that govern fluid flow are reduced to the more tractable Reynolds equation. An idealized model of a fracture, in which the roughness follows a sinusoidal variation, is studied in detail. This fracture is considered to consist of a random mixture of elements in which the fluid flows either parallel or transverse to the sinusoidal bumps. The overall permeability is then found by a suitable averaging procedure. The results are similar to those found by other researchers from numerical analysis of the Reynolds equation, in that the ratio of the hydraulic aperture to the mean aperture correlates well with the ratio of the mean aperture to the standard deviation of the aperture. Higher-order approximations to the Navier-Stokes equations for flow between sinusoidal walls are then studied, and it is concluded that in order for the lubrication approximation to be valid, the fracture walls must be smooth over lengths on the order of one standard deviation of the aperture, which is much less restrictive a condition than had previously been thought to apply. C1 POLYTECH INST NEW YORK,DEPT MECH ENGN,BROOKLYN,NY 11201. RP ZIMMERMAN, RW (reprint author), UNIV CALIF BERKELEY LAWRENCE BERKELEY LAB,DIV EARTH SCI,BERKELEY,CA 94720, USA. RI Kumar, Sunil/H-1082-2012; OI Zimmerman, Robert/0000-0001-6674-3403 NR 22 TC 111 Z9 116 U1 1 U2 12 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD, ENGLAND OX5 1GB SN 0148-9062 J9 INT J ROCK MECH MIN JI Int. J. Rock Mech. Min. Sci. PD JUL PY 1991 VL 28 IS 4 BP 325 EP 331 DI 10.1016/0148-9062(91)90597-F PG 7 WC Engineering, Geological; Mining & Mineral Processing SC Engineering; Mining & Mineral Processing GA GA570 UT WOS:A1991GA57000007 ER PT J AU ROMINE, CH AF ROMINE, CH TI ON AN UNSOLVED PROBLEM OF TAUSSKY,OLGA SO JOHNS HOPKINS APL TECHNICAL DIGEST LA English DT Article AB This article summarizes recent investigations about an unsolved problem in the distribution of eigenvalues over a class of matrices. Several elementary results in matrix theory are used to generate initial results. Empirical results based on a computational study are also presented. The empirical study was motivated by the ready availability of high-performance computers that can quickly compute thousands of eigenvalues. RP ROMINE, CH (reprint author), OAK RIDGE NATL LAB,DIV ENGN PHYS & MATH,COMP SCI GRP,OAK RIDGE,TN 37830, USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU JOHNS HOPKINS UNIV PI LAUREL PA APPLIED PHYSICS LABORATORY ATTN: MANAGING EDITOR JOHN HOPKINS RD, BLDG 1-E254, LAUREL, MD 20723-6099 SN 0270-5214 J9 J HOPKINS APL TECH D JI Johns Hopkins APL Tech. Dig. PD JUL-SEP PY 1991 VL 12 IS 3 BP 271 EP 274 PG 4 WC Engineering, Multidisciplinary SC Engineering GA GX478 UT WOS:A1991GX47800007 ER PT J AU MANSUR, LK AF MANSUR, LK TI THE SCIENCE AND ENGINEERING OF IRRADIATED MATERIALS SO JOM-JOURNAL OF THE MINERALS METALS & MATERIALS SOCIETY LA English DT Note RP MANSUR, LK (reprint author), OAK RIDGE NATL LAB,DIV MET & CERAM,OAK RIDGE,TN 37831, USA. NR 0 TC 1 Z9 1 U1 0 U2 0 PU MINERALS METALS MATERIALS SOC PI WARRENDALE PA 420 COMMONWEALTH DR, WARRENDALE, PA 15086 SN 1047-4838 J9 JOM-J MIN MET MAT S JI JOM-J. Miner. Met. Mater. Soc. PD JUL PY 1991 VL 43 IS 7 BP 34 EP 34 PG 1 WC Materials Science, Multidisciplinary; Metallurgy & Metallurgical Engineering; Mineralogy; Mining & Mineral Processing SC Materials Science; Metallurgy & Metallurgical Engineering; Mineralogy; Mining & Mineral Processing GA FZ553 UT WOS:A1991FZ55300008 ER PT J AU WEBER, WJ AF WEBER, WJ TI THE EFFECT OF RADIATION ON NUCLEAR WASTE FORMS SO JOM-JOURNAL OF THE MINERALS METALS & MATERIALS SOCIETY LA English DT Review ID RADIOACTIVE-WASTE; BOROSILICATE GLASS; MANAGEMENT; DAMAGE AB Radioactive decay within solidified nuclear wastes leads to physical and chemical changes that can alter the rate at which radionuclides are released to the biosphere. Under current policy, the geologic repository for such wastes is relied upon to meet federal release-rate regulations. If these regulatory and acceptance criteria cannot be achieved or are tightened, it may become necessary to rely more heavily on the physical and chemical durability of the waste form itself. Although radiation effects are known to degrade nuclear waste forms, the mechanisms and extent of the degradation are neither well understood nor under current investigation. RP WEBER, WJ (reprint author), PACIFIC NW LAB, DEPT MAT SCI, RICHLAND, WA 99352 USA. RI Weber, William/A-4177-2008 OI Weber, William/0000-0002-9017-7365 NR 59 TC 13 Z9 14 U1 0 U2 5 PU MINERALS METALS MATERIALS SOC PI WARRENDALE PA 420 COMMONWEALTH DR, WARRENDALE, PA 15086 SN 1047-4838 J9 JOM-J MIN MET MAT S JI JOM-J. Miner. Met. Mater. Soc. PD JUL PY 1991 VL 43 IS 7 BP 35 EP 39 PG 5 WC Materials Science, Multidisciplinary; Metallurgy & Metallurgical Engineering; Mineralogy; Mining & Mineral Processing SC Materials Science; Metallurgy & Metallurgical Engineering; Mineralogy; Mining & Mineral Processing GA FZ553 UT WOS:A1991FZ55300009 ER PT J AU PARKIN, DM AF PARKIN, DM TI HIGH-TC SUPERCONDUCTORS - A RADIATION-EFFECTS LABORATORY SO JOM-JOURNAL OF THE MINERALS METALS & MATERIALS SOCIETY LA English DT Review ID FAST-NEUTRON IRRADIATION; YBA2CU3O7 AB High-critical-temperature superconductors can be viewed as ceramic materials from a structural point of view and metallic superconductors from a properties perspective. This duality makes these materials exciting subjects for radiation-effects research. Observations from irradiation studies clearly illustrate ceramic-like damage processes, as well as effects on superconducting properties similar to those found in metallic superconductors. RP PARKIN, DM (reprint author), UNIV CALIF LOS ALAMOS SCI LAB, CTR MAT SCI, LOS ALAMOS, NM 87544 USA. NR 12 TC 0 Z9 0 U1 0 U2 2 PU MINERALS METALS MATERIALS SOC PI WARRENDALE PA 420 COMMONWEALTH DR, WARRENDALE, PA 15086 SN 1047-4838 J9 JOM-J MIN MET MAT S JI JOM-J. Miner. Met. Mater. Soc. PD JUL PY 1991 VL 43 IS 7 BP 45 EP 46 PG 2 WC Materials Science, Multidisciplinary; Metallurgy & Metallurgical Engineering; Mineralogy; Mining & Mineral Processing SC Materials Science; Metallurgy & Metallurgical Engineering; Mineralogy; Mining & Mineral Processing GA FZ553 UT WOS:A1991FZ55300011 ER PT J AU ROSS, PN AF ROSS, PN TI THE ROLE OF DEFECTS IN THE SPECIFIC ADSORPTION OF ANIONS ON PT(111) SO JOURNAL DE CHIMIE PHYSIQUE ET DE PHYSICO-CHIMIE BIOLOGIQUE LA English DT Article ID SINGLE-CRYSTAL ELECTRODES; PLATINUM STEPPED SURFACES; WORK FUNCTION; HYDROGEN ADSORPTION; ACIDIC SOLUTIONS; ADSORBED XENON; FORMIC-ACID; ZERO CHARGE; LEED; ELECTROSORPTION AB The specific adsorption of anions from hydrochloric and sulfuric acids was studied on Pt(111) surfaces containing two different types of deliberately induced defects. One type of defect surface used was the step-terrace structure produced by cutting a [111] oriented crystal a few degrees off the [111] zone axis. A second type was a randomly up-and-down stepped surface produced by ion bombardment and annealing. The atomic structure of the defect surfaces was determined by spot-profile analysis of LEED patterns in a UHV chamber directly coupled to the electrochemical cell. The vacuum work function of the surfaces was determined by UV photoemission. All of the step defects of the type studied lowered the work function of the surface in direct proportion to the step density, indicative of a local dipole at the step with the positive end of the dipole outward from the surface. The local work function at the step, and thus the local potential of zero charge (pzc), is lower at the step than at the atomically flat terrace. This difference in local pzc controls the coupling of the processes of hydrogen adsorption and anion desorption. On the atomically flat (111) terraces, which have the most positive pzc of all Pt surfaces, the processes are completely decoupled in dilute (mM) acids, with complete desorption of anions from the terraces at potentials more anodic than for the onset of hydrogen adsorption. The lower pzc for steps places the potential region for anion desorption/adsorption in the potential region for hydrogen adsorption/desorption, e.g. anion desorption from steps occurs simultaneously with hydrogen adsorption on the terraces. RP ROSS, PN (reprint author), UNIV CALIF BERKELEY LAWRENCE BERKELEY LAB,DIV MAT SCI,1 CYCLOTRON RD,MAILSTOP 2-200,BERKELEY,CA 94720, USA. NR 45 TC 52 Z9 52 U1 0 U2 6 PU EDITIONS SCIENTIFIQUES ELSEVIER PI PARIS CEDEX 15 PA 141 RUE JAVEL, 75747 PARIS CEDEX 15, FRANCE SN 0021-7689 J9 J CHIM PHYS PCB JI J. Chim. Phys.-Chim. Biol. PD JUL-AUG PY 1991 VL 88 IS 7-8 BP 1353 EP 1380 PG 28 WC Biochemistry & Molecular Biology; Chemistry, Physical SC Biochemistry & Molecular Biology; Chemistry GA GK345 UT WOS:A1991GK34500006 ER PT J AU HONSINGER, RW AF HONSINGER, RW TI ANAPHYLAXIS DURING INDUCTION OF GENERAL-ANESTHESIA - SUBSEQUENT EVALUATIONS AND MANAGEMENT - COMMENT SO JOURNAL OF ALLERGY AND CLINICAL IMMUNOLOGY LA English DT Letter RP HONSINGER, RW (reprint author), UNIV CALIF LOS ALAMOS SCI LAB,LOS ALAMOS,NM 87544, USA. NR 3 TC 0 Z9 0 U1 0 U2 0 PU MOSBY-YEAR BOOK INC PI ST LOUIS PA 11830 WESTLINE INDUSTRIAL DR, ST LOUIS, MO 63146-3318 SN 0091-6749 J9 J ALLERGY CLIN IMMUN JI J. Allergy Clin. Immunol. PD JUL PY 1991 VL 88 IS 1 BP 140 EP 140 DI 10.1016/0091-6749(91)90315-F PG 1 WC Allergy; Immunology SC Allergy; Immunology GA FY204 UT WOS:A1991FY20400020 PM 2071781 ER PT J AU WINANS, RE AF WINANS, RE TI PYROLYSIS FAST-ATOM-BOMBARDMENT TANDEM MASS-SPECTROMETRY CHARACTERIZATION OF COALS SO JOURNAL OF ANALYTICAL AND APPLIED PYROLYSIS LA English DT Article DE COALS; FAST ATOM BOMBARDMENT TANDEM MASS SPECTROMETRY; PYROLYSIS ID TEMPERATURE; LIQUEFACTION; MECHANISMS; CONVERSION; BEHAVIOR AB The objective of this study is to combine pyrolysis with various mass spectrometric techniques to characterize a set of the Argonne Premium coals. Pyrolysis high-resolution mass spectrometry (Py-HRMS) rapidly provides elemental compositions, while fast atom bombardment (FAB) mass spectrometry (MS) yields information on higher molecular weight species. Structural information for either of the approaches can be obtained by fragmentation of individual ions in a collision gas followed by mass analysis of the fragments. The MS/MS approach provides a wealth of information on very complex mixtures. These various techniques are examined and their advantages and limitations discussed. The emphasis will be placed on characterization of large and polar molecules. RP WINANS, RE (reprint author), ARGONNE NATL LAB, DIV CHEM, ARGONNE, IL 60439 USA. NR 31 TC 17 Z9 17 U1 0 U2 1 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0165-2370 J9 J ANAL APPL PYROL JI J. Anal. Appl. Pyrolysis PD JUL PY 1991 VL 20 BP 1 EP 13 DI 10.1016/0165-2370(91)80058-G PG 13 WC Chemistry, Analytical; Spectroscopy SC Chemistry; Spectroscopy GA GC789 UT WOS:A1991GC78900002 ER PT J AU GIULIANI, JD WANG, PR DYRKACZ, GR JOHNS, RB AF GIULIANI, JD WANG, PR DYRKACZ, GR JOHNS, RB TI THE CHARACTERIZATION OF 2 AUSTRALIAN BITUMINOUS COALS AND ISOLATED MACERAL FRACTIONS BY SEQUENTIAL PYROLYSIS-GAS CHROMATOGRAPHY MASS-SPECTROMETRY SO JOURNAL OF ANALYTICAL AND APPLIED PYROLYSIS LA English DT Article DE BITUMINOUS COALS; INERTINITE; PYROLYSIS; THERMAL DESORPTION; VITRINITE ID THERMAL-DESORPTION; HYDROCARBONS; THERMODESORPTION; RANK; GC AB Two Sydney Basin Bulli coals with differing coking properties are compared and characterised by thermal desorption and pyrolysis-GC/MS analyses. From the TD-GC/MS data a series of maturity indicators have been calculated and from the MPI-1 the calculated vitrinite reflectances have been obtained. On the basis of these maturity indicators, the two Australian coals compare well with a suite of northern hemisphere coals. Continuous flow centrifugation has been used to separate one coal (Bulli A) on a large scale into highly pure vitrinite and inertinite maceral fractions enabling comparative data to be obtained. The inertinite is distinguished from the vitrinite by the quantitative differences of many components released on pyrolysis. Bulli A can also be distinguished from Bulli B coal on a similar basis. The inertinite fraction gives a yield of volatiles 54% of that released from vitrinite and unexpectedly releases high proportions of n-alkanes and n-alkenes at 600-degrees-C pyrolysis. C1 ARGONNE NATL LAB,DIV CHEM,ARGONNE,IL 60439. RP GIULIANI, JD (reprint author), UNIV MELBOURNE,SCH CHEM,PARKVILLE,VIC 3052,AUSTRALIA. NR 12 TC 5 Z9 5 U1 0 U2 0 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0165-2370 J9 J ANAL APPL PYROL JI J. Anal. Appl. Pyrolysis PD JUL PY 1991 VL 20 BP 151 EP 159 DI 10.1016/0165-2370(91)80069-K PG 9 WC Chemistry, Analytical; Spectroscopy SC Chemistry; Spectroscopy GA GC789 UT WOS:A1991GC78900013 ER PT J AU TICIANELLI, EA BEERY, JG SRINIVASAN, S AF TICIANELLI, EA BEERY, JG SRINIVASAN, S TI DEPENDENCE OF PERFORMANCE OF SOLID POLYMER ELECTROLYTE FUEL-CELLS WITH LOW PLATINUM LOADING ON MORPHOLOGICAL-CHARACTERISTICS OF THE ELECTRODES SO JOURNAL OF APPLIED ELECTROCHEMISTRY LA English DT Article ID PHOSPHORIC-ACID; TECHNOLOGY; COMPONENTS; CARBON AB This paper describes the results of transmission electron microscopic, scanning electron microscopic and/or Rutherford backscattering spectroscopic analyses of platinum electrocatalysts supported on carbon, and of low catalyst loading gas-diffusion electrodes used in proton-exchange-membrane (PEM) fuel cells. We looked for correlations between the performance of PEM fuel cells and the morphology of low-catalyst-loading electrodes, taking into account the thickness of the catalyst layers, the crystallite sizes of the platinum electrocatalyst supported on carbon and the increased Pt catalyst content near the front of the electrodes. We reached the conclusion that the use of electrodes with thin catalyst layers (made by using platinum on carbon electrocatalysts with a high Pt/C weight ratio) and with more platinum localized near the front surface had the effect of diminishing the overpotentials in PEM fuel cells. C1 UNIV CALIF LOS ALAMOS SCI LAB,LOS ALAMOS,NM 87545. RI Ticianelli, Edson/D-1560-2012 OI Ticianelli, Edson/0000-0003-3432-2799 NR 14 TC 86 Z9 93 U1 3 U2 23 PU CHAPMAN HALL LTD PI LONDON PA 2-6 BOUNDARY ROW, LONDON, ENGLAND SE1 8HN SN 0021-891X J9 J APPL ELECTROCHEM JI J. Appl. Electrochem. PD JUL PY 1991 VL 21 IS 7 BP 597 EP 605 DI 10.1007/BF01024847 PG 9 WC Electrochemistry SC Electrochemistry GA FT514 UT WOS:A1991FT51400005 ER PT J AU LIU, HM POWELL, RC BOATNER, LA AF LIU, HM POWELL, RC BOATNER, LA TI ORIGIN OF PICOSECOND-PULSE-INDUCED, DEGENERATE 4-WAVE-MIXING SIGNALS IN KTA1-XNBXO3 CRYSTALS SO JOURNAL OF APPLIED PHYSICS LA English DT Article ID ALEXANDRITE CRYSTALS; LITHIUM TANTALATE; RAMAN-SCATTERING; SPECTROSCOPY; LINBO3; LUMINESCENCE; MIGRATION; CR-3+; KTN AB Transient gratings have been produced in KTa(1-x)Nb(x)O3 by picosecond-pulse, two-photon excitation using degenerate four-wave-mixing techniques. The excitation process has been characterized through fluorescence studies, and the fluorescence is attributed to the transition between an excited state and the ground state of B4+ ions that are produced in ABO3 perovskite crystals. Strong electron-phonon coupling gives rise to the luminescence quenching. The observed degenerate four-wave-mixing signal is shown to be due predominantly to a phase grating caused by a change in the susceptibility associated with the formation of Nb4+ or Ta4+ ions in the peak region of the grating. The grating signal intensity was found to be dependent on the concentration of niobium ions and the crossing angle of the two laser write beams. C1 OAK RIDGE NATL LAB,DIV SOLID STATE,OAK RIDGE,TN 37830. RP LIU, HM (reprint author), OKLAHOMA STATE UNIV,CTR LASER RES,STILLWATER,OK 74078, USA. RI Boatner, Lynn/I-6428-2013 OI Boatner, Lynn/0000-0002-0235-7594 NR 36 TC 36 Z9 37 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 JUL 1 PY 1991 VL 70 IS 1 BP 20 EP 28 DI 10.1063/1.350312 PG 9 WC Physics, Applied SC Physics GA FV069 UT WOS:A1991FV06900005 ER PT J AU AHRENKIEL, RK KEYES, BM DUNLAVY, DJ AF AHRENKIEL, RK KEYES, BM DUNLAVY, DJ TI INTENSITY-DEPENDENT MINORITY-CARRIER LIFETIME IN III-V-SEMICONDUCTORS DUE TO SATURATION OF RECOMBINATION CENTERS SO JOURNAL OF APPLIED PHYSICS LA English DT Article ID EPITAXIAL GAAS; INTERFACE; PHOTOLUMINESCENCE; ABSORPTION; VELOCITY AB The minority-carrier lifetime has been measured by time-resolved photoluminescence in a variety of III-V epitaxial material including GaAs and Al(x)Ga1-xAs. In cases where Shockley-Read-Hall recombination is dominant, the measured lifetimes are dependent upon the intensity of the excitation source. These lifetime effects can be described by a Shockley-Read-Hall model that includes the injection dependence of the recombination. As the lifetimes increase with the injection level, we describe the effects as the saturation of recombination centers. RP AHRENKIEL, RK (reprint author), SOLAR ENERGY RES INST,GOLDEN,CO 80401, USA. NR 22 TC 65 Z9 66 U1 2 U2 21 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 JUL 1 PY 1991 VL 70 IS 1 BP 225 EP 231 DI 10.1063/1.350315 PG 7 WC Physics, Applied SC Physics GA FV069 UT WOS:A1991FV06900035 ER PT J AU WARREN, WL RONG, FC POINDEXTER, EH GERARDI, GJ KANICKI, J AF WARREN, WL RONG, FC POINDEXTER, EH GERARDI, GJ KANICKI, J TI STRUCTURAL IDENTIFICATION OF THE SILICON AND NITROGEN DANGLING-BOND CENTERS IN AMORPHOUS-SILICON NITRIDE SO JOURNAL OF APPLIED PHYSICS LA English DT Article ID NUCLEAR DOUBLE-RESONANCE; ELECTRON-SPIN-RESONANCE; THIN-FILM TRANSISTORS; DOMINANT DEEP TRAP; PARAMAGNETIC DEFECTS; CORRELATION-ENERGY; ANNEALED SILICON; 1ST OBSERVATION; STATES; GLASSES AB We report the observation of both silicon and nitrogen paramagnetic defect centers using X-band and Q-band electron spin resonance microwave excitation frequencies. By using two different microwave frequencies along with a computer analysis of the resonance lineshapes, we have been able to confirm and extend earlier observations regarding the chemical identity of these paramagnetic defects. Specifically, we provide additional evidence that the silicon dangling bond, i.e., K center, is an unpaired electron on a silicon atom bonded to three nitrogen atoms in stoichiometric silicon nitride. We further demonstrate that the g tensor of the K center exhibits very little anisotropy and that the lineshape is broadened primarily by hyperfine interactions of the nitrogens bonded to the silicon atom. We also confirm that the recently observed nitrogen dangling-bond resonance in silicon nitride is indeed due to a hyperfine interaction with a nitrogen nucleus. This improved understanding of these two important paramagnetic defects may be importance in eliminating or perhaps exploiting their chemical properties. C1 SANDIA NATL LABS,DIV ELECTR PROPERTIES MAT,ALBUQUERQUE,NM 87185. IBM CORP,THOMAS J WATSON RES CTR,DIV RES,YORKTOWN HTS,NY 10598. RP WARREN, WL (reprint author), ELECTR TECHNOL & DEVICES LAB,FT MONMOUTH,NJ 07703, USA. RI Kanicki, Jerzy/E-2753-2016 OI Kanicki, Jerzy/0000-0002-3649-8360 NR 55 TC 65 Z9 65 U1 1 U2 5 PU AMER INST PHYSICS PI WOODBURY PA CIRCULATION FULFILLMENT DIV, 500 SUNNYSIDE BLVD, WOODBURY, NY 11797-2999 SN 0021-8979 J9 J APPL PHYS JI J. Appl. Phys. PD JUL 1 PY 1991 VL 70 IS 1 BP 346 EP 354 DI 10.1063/1.350280 PG 9 WC Physics, Applied SC Physics GA FV069 UT WOS:A1991FV06900054 ER PT J AU UEHARA, Y NUMABE, A KAWABATA, Y NAGATA, T IWAI, J MATSUOKA, H YAGI, S TAKABATAKE, Y SUGIMOTO, T AF UEHARA, Y NUMABE, A KAWABATA, Y NAGATA, T IWAI, J MATSUOKA, H YAGI, S TAKABATAKE, Y SUGIMOTO, T TI EVIDENCE FOR MEDIAL-MASS REGRESSION IN THE VASCULAR WALL OF DAHL HYPERTENSIVE RATS BY CICLETANINE TREATMENT SO JOURNAL OF CARDIOVASCULAR PHARMACOLOGY LA English DT Article DE CICLETANINE; VASCULAR WALLS; CELL GROWTH; ACTIN; VASCULAR SMOOTH MUSCLE CELL; HYPERTROPHY; HYPERPLASIA; DAHL-S RATS ID SMOOTH-MUSCLE CELLS; GROWTH AB We designed experiments to investigate the effects of cicletanine, a novel antihypertensive drug, on medial hypertrophy in Dahl rats susceptible to salt-induced hypertension (Dahl S rats). Cicletanine treatment (500 mg of cicletanine/kg of chow) for 6 weeks lowered blood pressure by 19% in Dahl S rats challenged with a high-salt (4%) diet. The blood pressure reduction was associated with a significant decrease in weight of the aortic vessels. Morphological examination revealed that this treatment decreased medial hypertrophy and expansion of intimal tissue, in concert with resolution of the periarteritis in the intrarenal arteries. In fact, the content of actin in the aortic wall, analyzed by SDS-PAGE, was decreased significantly with this treatment and myosin content was reduced to the same extent as well. Moreover, cicletanine per se lowered protein synthesis in randomly cycling cultured vascular smooth muscle cells (VSMCs) from Sprague-Dawley rats. Actin formation by VSMCs was decreased with cicletanine. Thus, these data indicate that chronic cicletanine treatment produces regression of the medial hypertrophy in Dahl S rats. Direct inhibitory effects on cytoskeleton protein synthesis, as well as its antihypertensive action, are partly responsible for this regression in vivo. C1 DOKKYO UNIV,SCH MED,DEPT MED,DIV HYPERTENS & CARDIORENAL DIS,MIBU,TOCHIGI 32102,JAPAN. KOSHIGAYA HOSP,TOCHIGI,JAPAN. BROOKHAVEN NATL LAB,UPTON,NY 11973. RP UEHARA, Y (reprint author), UNIV TOKYO,DEPT MED 2,7-3-1 HONGO,BUNKYO KU,TOKYO 113,JAPAN. NR 23 TC 9 Z9 9 U1 0 U2 1 PU LIPPINCOTT-RAVEN PUBL PI PHILADELPHIA PA 227 EAST WASHINGTON SQ, PHILADELPHIA, PA 19106 SN 0160-2446 J9 J CARDIOVASC PHARM JI J. Cardiovasc. Pharmacol. PD JUL PY 1991 VL 18 IS 1 BP 158 EP 166 DI 10.1097/00005344-199107000-00021 PG 9 WC Cardiac & Cardiovascular Systems; Pharmacology & Pharmacy SC Cardiovascular System & Cardiology; Pharmacology & Pharmacy GA FU138 UT WOS:A1991FU13800021 PM 1719285 ER PT J AU OUTKA, DA FOLTZ, GW AF OUTKA, DA FOLTZ, GW TI MECHANISTIC STUDIES OF THE ISOTOPIC-EXCHANGE REACTION BETWEEN GASEOUS-HYDROGEN AND PALLADIUM HYDRIDE POWDER SO JOURNAL OF CATALYSIS LA English DT Article ID ADSORPTION; PD(111); SURFACE; SYSTEM RP OUTKA, DA (reprint author), SANDIA NATL LABS,LIVERMORE,CA 94551, USA. NR 12 TC 7 Z9 7 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 0021-9517 J9 J CATAL JI J. Catal. PD JUL PY 1991 VL 130 IS 1 BP 268 EP 282 DI 10.1016/0021-9517(91)90109-H PG 15 WC Chemistry, Physical; Engineering, Chemical SC Chemistry; Engineering GA FR445 UT WOS:A1991FR44500024 ER PT J AU MATSUNAMI, RK YETTE, ML STEVENS, A NIYOGI, SK AF MATSUNAMI, RK YETTE, ML STEVENS, A NIYOGI, SK TI MUTATIONAL ANALYSIS OF LEUCINE-47 IN HUMAN EPIDERMAL GROWTH-FACTOR SO JOURNAL OF CELLULAR BIOCHEMISTRY LA English DT Article DE HEGF; SITE-DIRECTED MUTAGENESIS; RECEPTOR AFFINITY; RECEPTOR KINASE; MITOGENESIS; NMR ID SITE-DIRECTED MUTAGENESIS; NUCLEAR-MAGNETIC-RESONANCE; FACTOR RECEPTOR; KINASE-ACTIVITY; RESIDUES; PROTEIN; BINDING; DOMAIN; EGF AB Seven site-specific mutants (including changes to other hydrophobic, charged, and heterocyclic amino acids) of leucine 47 of human epidermal growth factor (EGF) were generated by protein engineering and characterized for their activity in three assays: radioreceptor competition binding in membrane fractions, the stimulation of the EGF receptor's tyrosine kinase activity, and the stimulation of thymidine uptake in tissue culture cells. K1/2 (concentration required for half maximum response) values for each of the mutants are reported in the three assays. The results show that the native leucine residue is quite important for EGF activity. Substitutions are tolerated to different degrees, depending upon hydrophobicity and size of the side chain. Substitution with ionic residues led to the most drastic reduction in activity. One-dimensional nuclear magnetic resonance spectroscopy, at physiological pH, of several of the mutants did not detect any major structural perturbations which would account for the loss of activity. The results suggest that the side chain of leucine 47, because of its charge neutrality, size, and hydrophobicity, is highly important, although not absolutely essential for the interaction of EGF with its receptor. A striking finding was the lower (compared with wild type) V(max) values of the mutants in the tyrosine kinase reaction, but these low V(max) mutants, in cell culture experiments, were able to stimulate at high concentrations a growth response equivalent to wild type EGF. C1 OAK RIDGE NATL LAB,DIV BIOL,POB 2009,OAK RIDGE,TN 37831. FU NCI NIH HHS [CA 09104, CA 50735] NR 24 TC 42 Z9 42 U1 0 U2 5 PU WILEY-LISS PI NEW YORK PA DIV JOHN WILEY & SONS INC 605 THIRD AVE, NEW YORK, NY 10158-0012 SN 0730-2312 J9 J CELL BIOCHEM JI J. Cell. Biochem. PD JUL PY 1991 VL 46 IS 3 BP 242 EP 249 DI 10.1002/jcb.240460307 PG 8 WC Biochemistry & Molecular Biology; Cell Biology SC Biochemistry & Molecular Biology; Cell Biology GA FX059 UT WOS:A1991FX05900006 PM 1774224 ER PT J AU BUTENHOFF, TJ ROHLFING, EA AF BUTENHOFF, TJ ROHLFING, EA TI LASER-INDUCED FLUORESCENCE SPECTROSCOPY OF JET-COOLED SIC2 SO JOURNAL OF CHEMICAL PHYSICS LA English DT Article ID LABORATORY MEASUREMENT; SPECTRUM; VAPORIZATION; MATRIX AB We present a spectroscopic study of the approximately A 1B2 <-- approximately X 1A1 system of jet-cooled SiC2 that includes both laser-induced fluorescence (LIF) excitation and dispersed fluorescence (DF) spectra. Rotational analysis of several previously unobserved bands in the LIF spectrum enables us to reassign the vibronic structure in the approximately A 1B2 <-- approximately X 1A1 system and gives an accurate term energy for the low-frequency, antisymmetric mode in the ground state, G(0,0,1) = 196.37 (4) cm-1. Analysis of DF spectra from ten different approximately A-state levels yields vibrational term energies for 43 levels in the ground state, including (0,0,nu-3") levels as high as nu-3" = 16. The rapidly decreasing level spacings in the (0,0,nu-3") progression, coupled with a dramatic decrease in the small inertial moment, give insight into the extreme anharmonic potential surface of the ground state. These data also provide indirect evidence for the onset of large-amplitude pseudorotation that samples both cyclic and linear minima. In contrast, the approximately A state is quite harmonic at the cyclic minimum, indicative of a more substantial barrier between the two isomers. RP BUTENHOFF, TJ (reprint author), SANDIA NATL LABS,COMBUST RES FACIL,LIVERMORE,CA 94551, USA. NR 28 TC 36 Z9 36 U1 0 U2 6 PU AMER INST PHYSICS PI WOODBURY PA CIRCULATION FULFILLMENT DIV, 500 SUNNYSIDE BLVD, WOODBURY, NY 11797-2999 SN 0021-9606 J9 J CHEM PHYS JI J. Chem. Phys. PD JUL 1 PY 1991 VL 95 IS 1 BP 1 EP 8 DI 10.1063/1.461476 PG 8 WC Chemistry, Physical; Physics, Atomic, Molecular & Chemical SC Chemistry; Physics GA FT847 UT WOS:A1991FT84700001 ER PT J AU SCHMUTTENMAER, CA COHEN, RC LOESER, JG SAYKALLY, RJ AF SCHMUTTENMAER, CA COHEN, RC LOESER, JG SAYKALLY, RJ TI FAR-INFRARED VIBRATION-ROTATION-TUNNELING SPECTROSCOPY OF AR-NH3 - INTERMOLECULAR VIBRATIONS AND EFFECTIVE ANGULAR POTENTIAL-ENERGY SURFACE SO JOURNAL OF CHEMICAL PHYSICS LA English DT Article ID VANDERWAALS COEFFICIENTS; LASER SPECTROSCOPY; INTERNAL-ROTATION; SPECTRUM; MICROWAVE; AR; COMPLEXES; AR-H2O; STATES; DIPOLE AB Two new intermolecular vibration-rotation-tunneling (VRT) bands of Ar-NH3 have been measured using tunable far infrared laser spectroscopy. We have unambiguously assigned these and a previously measured FIR band [Gwo et al., Mol. Phys. 71, 453 (1990)] as PI(1(0),n = 0) <-- SIGMA(0(0),n = 0), SIGMA(1(0),n = 0) <-- SIGMA(0(0),n = 0), and SIGMA(0(0),n = 1) <-- SIGMA(0(0),n = 0). The three upper states of these are found to be strongly mixed by anisotropy and Coriolis effects. A simultaneous least squares fit of all transitions has yielded vibrational frequencies, rotational and centrifugal distortion constants, and a Coriolis parameter as well as quadrupole hyperfine coupling constants for the upper states. An effective angular potential energy surface for Ar-NH3 in its lowest stretching state has been determined from these data, after explicitly accounting for the effects of bend stretch interactions. Features of the surface include a global minimum at the near T-shaped configuration (theta = 90-degrees), a 30 cm-1 to 60 cm-1 barrier to rotation at theta = 180-degrees (or 0-degrees), and a very low barrier or possibly a secondary minimum at theta = 0-degrees (or 180-degrees). Both attractive and repulsive interactions are shown to contribute significantly to the anisotropic forces in the complex. Comparison with ab initio calculations are presented. C1 UNIV CALIF BERKELEY LAWRENCE BERKELEY LAB,DIV MAT & CHEM SCI,BERKELEY,CA 94720. RP SCHMUTTENMAER, CA (reprint author), UNIV CALIF BERKELEY,DEPT CHEM,BERKELEY,CA 94720, USA. RI Cohen, Ronald/A-8842-2011 OI Cohen, Ronald/0000-0001-6617-7691 NR 37 TC 44 Z9 45 U1 0 U2 2 PU AMER INST PHYSICS PI WOODBURY PA CIRCULATION FULFILLMENT DIV, 500 SUNNYSIDE BLVD, WOODBURY, NY 11797-2999 SN 0021-9606 J9 J CHEM PHYS JI J. Chem. Phys. PD JUL 1 PY 1991 VL 95 IS 1 BP 9 EP 21 DI 10.1063/1.461430 PG 13 WC Chemistry, Physical; Physics, Atomic, Molecular & Chemical SC Chemistry; Physics GA FT847 UT WOS:A1991FT84700002 ER PT J AU SHIN, KS MICHAEL, JV AF SHIN, KS MICHAEL, JV TI RATE CONSTANTS FOR THE REACTIONS H+O2-]OH+O AND D+O2-]OD+O OVER THE TEMPERATURE-RANGE 1085-2278-K BY THE LASER PHOTOLYSIS SHOCK-TUBE TECHNIQUE SO JOURNAL OF CHEMICAL PHYSICS LA English DT Article ID THERMAL RATE COEFFICIENT; POTENTIAL-ENERGY SURFACES; GROUND-STATE HO2; FLASH-PHOTOLYSIS; + O; TRAJECTORY CALCULATIONS; CHEMICAL-KINETICS; REACTION H; ABSORPTION; DYNAMICS AB Rate constants for the reactions (1) H + O2 --> OH + O and (2) D + O2 --> OD + O have been measured over the temperature ranges 1103-2055 K and 1085-2278 K, respectively. The experimental method that has been used is the laser photolysis-shock tube technique. This technique utilizes atomic resonance absorption spectrophotometry (ARAS) to monitor H- or D-atom depletion in the presence of a large excess of reactant, O2. The results can be well represented by the Arrhenius expressions k1(T) = (1.15 +/- 0.16) x 10(-10) exp(-6917 +/- 193 K/T) cm3 molecule-1 s-1, and k2(T) = (1.09 +/- 0.20) x 10(-10) exp(-6937 +/- 247 K/T) cm3 molecule-1 s-1. Over the experimental temperature range, the present results show that the isotope effect is unity within experimental uncertainty. The Arrhenius equations, k1(T) = (8.75 +/- 1.24) x 10(-12) exp(1121 +/- 193 K/T) cm3 molecule-1 s-1 and k2(T) = (9.73 +/- 1.79) x 10(-12) exp(526 +/- 247 K/T) cm3 molecule-1 s-1, for the rate constants of the reverse reactions were calculated from the experimentally measured forward rate constants and expressions for the equilibrium constants that have been derived from the JANAF thermochemical database. The theoretical implications of the present results are also discussed. RP SHIN, KS (reprint author), ARGONNE NATL LAB, DIV CHEM, ARGONNE, IL 60439 USA. RI Michael, Joe/E-3907-2010 NR 63 TC 52 Z9 52 U1 0 U2 3 PU AMER INST PHYSICS PI MELVILLE PA CIRCULATION & FULFILLMENT DIV, 2 HUNTINGTON QUADRANGLE, STE 1 N O 1, MELVILLE, NY 11747-4501 USA SN 0021-9606 J9 J CHEM PHYS JI J. Chem. Phys. PD JUL 1 PY 1991 VL 95 IS 1 BP 262 EP 273 DI 10.1063/1.461483 PG 12 WC Chemistry, Physical; Physics, Atomic, Molecular & Chemical SC Chemistry; Physics GA FT847 UT WOS:A1991FT84700027 ER PT J AU PINNADUWAGE, LA CHRISTOPHOROU, LG BITOUNI, AP AF PINNADUWAGE, LA CHRISTOPHOROU, LG BITOUNI, AP TI ENHANCED ELECTRON-ATTACHMENT TO SUPEREXCITED STATES OF SATURATED TERTIARY-AMINES SO JOURNAL OF CHEMICAL PHYSICS LA English DT Article ID MULTI-PHOTON IONIZATION; DISSOCIATIVE ATTACHMENT; EXCITED TRIMETHYLAMINE; RELAXATION PROCESSES; ENERGY COLLISIONS; EXCITATION; TEMPERATURE; MOLECULES; SF6; DEPENDENCE AB Electron attachment measurements on excimer-laser-excited superexcited states (SES) of saturated amine compounds, and in particular on triethylamine (TEA), have been carried out employing a new experimental technique. A rate equation analysis based on a proposed model shows that the electron attachment rate constant for the SES is several orders of magnitude larger than that for the ground electronic state. The proposed mechanism for electron attachment to SES involves the capture of a near-zero-energy electron-(produced by the same laser pulse that produces the SES)-by a superexcited molecule to form a transient parent anion which subsequently dissociates producing a stable fragment anion. The similarity of the above mechanism to an electron-excited Feshbach resonance is indicated and a scheme for the identification of molecular systems that can be excited (via resonance-enhanced multiphoton excitation) to SES is outlined. C1 UNIV TENNESSEE,DEPT PHYS,KNOXVILLE,TN 37996. RP PINNADUWAGE, LA (reprint author), OAK RIDGE NATL LAB,DIV HLTH & SAFETY RES,ATOM MOLEC & HIGH VOLTAGE GRP,OAK RIDGE,TN 37831, USA. NR 56 TC 30 Z9 30 U1 0 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 JUL 1 PY 1991 VL 95 IS 1 BP 274 EP 287 DI 10.1063/1.461484 PG 14 WC Chemistry, Physical; Physics, Atomic, Molecular & Chemical SC Chemistry; Physics GA FT847 UT WOS:A1991FT84700028 ER PT J AU CROMWELL, EF LIU, DJ VRAKKING, MJJ KUNG, AH LEE, YT AF CROMWELL, EF LIU, DJ VRAKKING, MJJ KUNG, AH LEE, YT TI DYNAMICS OF H2 ELIMINATION FROM CYCLOHEXADIENE SO JOURNAL OF CHEMICAL PHYSICS LA English DT Article ID PHOTODISSOCIATION DYNAMICS; VECTOR CORRELATIONS; MOLECULAR-BEAM; 1,4-CYCLOHEXADIENE; SPECTROSCOPY; H-2; VELOCITY; 1,3-CYCLOHEXADIENE; DISTRIBUTIONS; FORMALDEHYDE AB A comprehensive study of the dynamics of H2 elimination from 1,4 and 1,3 cyclohexadiene is reported. Rotational and vibrational quantum state distributions as well as translation energy distributions for the H2 product are measured. State specific detection of H2 is accomplished with a transform limited vacuum ultraviolet-extreme ultraviolet laser system via (1 + 1) resonance enhanced multiphoton ionization (REMPI). Rate constants for the H2 elimination and 1,4 to 1,3 isomerization reactions are derived. A (v,J) correlation for H2 with v parallel-to J primarily is observed from anisotropy in the Doppler profiles. A clear picture of the transition state configuration of 1,4 cyclohexadiene is provided from the information obtained. C1 UNIV CALIF BERKELEY,DEPT CHEM,BERKELEY,CA 94720. RP CROMWELL, EF (reprint author), UNIV CALIF BERKELEY LAWRENCE BERKELEY LAB,DIV CHEM SCI,BERKELEY,CA 94720, USA. RI Lee, Yuan-Tseh/F-7914-2012; Kung, Andy/F-7909-2012 NR 39 TC 22 Z9 22 U1 2 U2 10 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 JUL 1 PY 1991 VL 95 IS 1 BP 297 EP 307 DI 10.1063/1.461487 PG 11 WC Chemistry, Physical; Physics, Atomic, Molecular & Chemical SC Chemistry; Physics GA FT847 UT WOS:A1991FT84700030 ER PT J AU BANERJEE, A AF BANERJEE, A TI ABINITIO CORRELATED VALENCE SHELL EFFECTIVE HAMILTONIAN METHOD FOR ATOMIC AND MOLECULAR-SYSTEMS SO JOURNAL OF CHEMICAL PHYSICS LA English DT Article ID EFFECTIVE CORE POTENTIALS AB A new method for correlated electronic structure calculations that makes explicit reference to valence electrons only is presented for atomic and molecular processes in which the core electrons remain inert. The method is based on constructing a valence Hamiltonian that includes a one-electron effective potential for the core-valence interactions. It exactly reproduces all properties (wave functions, energies, etc.) of an all electron calculation with frozen core wave functions with same bases. It has no adjustable parameters, and no restrictions on the choice of basis sets. It yields considerable savings of computer time and space over the corresponding all electron calculations. Self-consistent field (SCF) and complete active space multiconfiguration self-consistent field (CAS-MCSCF) test calculations on ground states of F,F-, and S are presented. RP BANERJEE, A (reprint author), EG&G IDAHO INC,IDAHO NATL ENGN LAB,THEORET CHEM PROJECT,POB 1625,IDAHO FALLS,ID 83415, USA. NR 22 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 0021-9606 J9 J CHEM PHYS JI J. Chem. Phys. PD JUL 1 PY 1991 VL 95 IS 1 BP 395 EP 402 DI 10.1063/1.461441 PG 8 WC Chemistry, Physical; Physics, Atomic, Molecular & Chemical SC Chemistry; Physics GA FT847 UT WOS:A1991FT84700040 ER PT J AU VIECELLI, JA CANFIELD, EH AF VIECELLI, JA CANFIELD, EH TI FUNCTIONAL REPRESENTATION OF POWER-LAW RANDOM-FIELDS AND TIME-SERIES SO JOURNAL OF COMPUTATIONAL PHYSICS LA English DT Article C1 UNIV CALIF LAWRENCE LIVERMORE NATL LAB,LIVERMORE,CA 94550. NR 11 TC 10 Z9 11 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 0021-9991 J9 J COMPUT PHYS JI J. Comput. Phys. PD JUL PY 1991 VL 95 IS 1 BP 29 EP 39 DI 10.1016/0021-9991(91)90251-F PG 11 WC Computer Science, Interdisciplinary Applications; Physics, Mathematical SC Computer Science; Physics GA FR893 UT WOS:A1991FR89300002 ER PT J AU BAUGHMAN, RJ AF BAUGHMAN, RJ TI QUARTZ CRYSTAL-GROWTH SO JOURNAL OF CRYSTAL GROWTH LA English DT Article AB A successful method for growing high quality synthetic quartz crystals directly from a fused silica nutrient material is reported. This method overcomes problems, such as massive transport of silicate material, which results in uncontrollable deposition of nutrient on seed crystals as well as significant spurious nucleation and growth within the growth chamber. Very high purity fused silica is now being produced from the vast supplies of amorphous silica available on this continent. This method thus permits these amorphous materials to be used for the growth of synthetic quartz crystals. RP BAUGHMAN, RJ (reprint author), SANDIA NATL LABS,ALBUQUERQUE,NM 87185, USA. NR 7 TC 7 Z9 7 U1 0 U2 2 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 JUL PY 1991 VL 112 IS 4 BP 753 EP 757 DI 10.1016/0022-0248(91)90132-O PG 5 WC Crystallography; Materials Science, Multidisciplinary; Physics, Applied SC Crystallography; Materials Science; Physics GA GA813 UT WOS:A1991GA81300017 ER PT J AU SEKAR, RR MARR, WW ASSANIS, DN COLE, RL MARCINIAK, TJ SCHAUS, JE AF SEKAR, RR MARR, WW ASSANIS, DN COLE, RL MARCINIAK, TJ SCHAUS, JE TI OXYGEN-ENRICHED DIESEL-ENGINE PERFORMANCE - A COMPARISON OF ANALYTICAL AND EXPERIMENTAL RESULTS SO JOURNAL OF ENGINEERING FOR GAS TURBINES AND POWER-TRANSACTIONS OF THE ASME LA English DT Article AB Use of oxygen-enriched combustion air in diesel engines can lead to significant improvements in power density, as well as reductions in particulate emissions, but at the expense of higher NO(x) emissions. Oxygen enrichment would also lead to lower ignition delays and the opportunity to burn lower grade fuels. Analytical and experimental studies are being conducted in parallel to establish the optimal combination of oxygen level and diesel fuel properties. In this paper, cylinder pressure data acquired on a single-cylinder engine are used to generate heat release rates for operation under various oxygen contents. These derived heat release rates are in turn used to improve the combustion correlation-and thus the prediction capability-of the simulation code. It is shown that simulated and measured cylinder pressures and other performance parameters are in good agreement. The improved simulation can provide sufficiently accurate predictions of trends and magnitudes to be useful in parametric studies assessing the effects of oxygen enrichment and water injection on diesel engine performance. Measured ignition delays, NO(x) emissions, and particulate emissions are also compared with previously published data. The measured ignition delays are slightly lower than previously reported. Particulate emissions measured in this series of tests are significantly lower than previously reported. C1 UNIV ILLINOIS,URBANA,IL 61801. AUTORESEARCH LABS INC,CHICAGO,IL 60638. RP SEKAR, RR (reprint author), ARGONNE NATL LAB,ARGONNE,IL 60439, USA. NR 14 TC 6 Z9 6 U1 1 U2 3 PU ASME-AMER SOC MECHANICAL ENG PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 SN 0742-4795 J9 J ENG GAS TURB POWER JI J. Eng. Gas. Turbines Power-Trans. ASME PD JUL PY 1991 VL 113 IS 3 BP 365 EP 369 DI 10.1115/1.2906239 PG 5 WC Engineering, Mechanical SC Engineering GA FY394 UT WOS:A1991FY39400007 ER PT J AU CARLSON, CL ADRIANO, DC AF CARLSON, CL ADRIANO, DC TI GROWTH AND ELEMENTAL CONTENT OF 2 TREE SPECIES GROWING ON ABANDONED COAL FLY-ASH BASINS SO JOURNAL OF ENVIRONMENTAL QUALITY LA English DT Article ID AMENDED SOIL; SELENIUM; PLANTS; ECOSYSTEMS; SEEDLINGS; DISPOSAL; PH AB Differences in aboveground tissue concentrations of trace elements were assessed for sweetgum (Liquidambar styraciflua L.) and sycamore (Platanus occidentalis L.) growing on two abandoned coal fly ash basins and a control soil (Fuquay sand; loamy, siliceous, thermic Arenic Plinthic Kandiudult; pH = 4.99). The "wet basin" (pH = 5.58) had originally received precipitator ash in an ash-water slurry, while the "dry basin" (pH = 8.26) had received both precipitator and bottom ash in dry form. In general, trees from the wet basin exhibited elevated trace element concentrations in comparison to the controls, while the dry basin trees exhibited reduced concentrations. One of the most striking differences in elemental concentrations among the ash basin and control trees was observed for Mn, with the control trees exhibiting concentrations orders of magnitude greater than the ash basin trees. Differences in foliar trace element concentrations among the sites can generally be explained by differences in substrate trace element concentrations and/or substrate pH. While trees from the wet ash basin generally had the highest trace element concentrations, these trees also attained the greatest height and diameter growth, suggesting that the elevated trace element concentrations in the wet basin substrate are not limiting the establishment of these two species. The greater height and diameter growth of the wet basin trees is presumably a result of the greater water-holding capacity of the substrate on this site. Differences in growth and tissue concentrations between sweetgum and sycamore highlight the importance of using more than one species when assessing metal toxicity or deficiency on a given substrate. C1 SAVANNAH RIVER ECOL LAB,DIV BIOGEOCHEM,AIKEN,SC 29802. NR 30 TC 26 Z9 29 U1 1 U2 6 PU AMER SOC AGRONOMY PI MADISON PA 677 S SEGOE RD, MADISON, WI 53711 SN 0047-2425 J9 J ENVIRON QUAL JI J. Environ. Qual. PD JUL-SEP PY 1991 VL 20 IS 3 BP 581 EP 587 PG 7 WC Environmental Sciences SC Environmental Sciences & Ecology GA FZ678 UT WOS:A1991FZ67800013 ER PT J AU PHANTHIEN, N TRANCONG, T GRAHAM, AL AF PHANTHIEN, N TRANCONG, T GRAHAM, AL TI SHEAR-FLOW OF PERIODIC ARRAYS OF PARTICLE CLUSTERS - A BOUNDARY-ELEMENT METHOD SO JOURNAL OF FLUID MECHANICS LA English DT Article ID LOW-REYNOLDS-NUMBER; SLOW VISCOUS FLOW; STOKES-FLOW; MULTIPARTICLE SYSTEMS; INTERACTING SPHERES; EFFECTIVE VISCOSITY; DYNAMIC SIMULATION; MOBILITY FUNCTIONS; CONVEX PARTICLES; NUMERICAL-METHOD AB The boundary-element method is used to solve Stokes equations for periodic arrays of force-free and torque-free rigid particles. Simple cubic arrays of spheres, spheroids, cubes, and clusters of spheres are subjected to a bulk simple shearing flow. The effective volume-averaged stress tensor for the suspension and the detailed velocity and stress fields throughout the Newtonian suspending fluid are calculated. We find that even crude meshes give very good volume-averaged results, but fine meshes are required to track local minima and maxima in the stress field. For simple cubic arrays of spheres, the boundary-element results are in excellent agreement with the analytical viscosity predictions of Nunan & Keller (1984). Even at the highest concentration of solids studied, no significant normal stress differences were observed, in agreement with Nunan & Keller's results (1984). Up to moderate concentrations of particles, the volume-averaged properties of the suspension display only a weak dependence on the particle geometry. Suspensions of spheroids and cubes behave approximately as suspensions of spheres on the average despite large differences in the local micromechanics of stress and velocity fields. Simple cubic arrays of clusters of spheres tend to behave on a macroscopic level as a cubic array of spheres whose effective volume fraction is about 150% of the total volume fraction of the spheres in the clusters. C1 UNIV COLL SO QUEENSLAND,DEPT MECH ENGN,TOOWOOMBA,QLD 4350,AUSTRALIA. UNIV CALIF LOS ALAMOS SCI LAB,DIV MECH & ELECTR ENGN,LOS ALAMOS,NM 87545. RP PHANTHIEN, N (reprint author), UNIV SYDNEY,DEPT MECH ENGN,SYDNEY,NSW 2006,AUSTRALIA. RI Tran-Cong, Thanh/G-1077-2010; Phan-Thien, Nhan/I-4705-2012 OI Tran-Cong, Thanh/0000-0002-7919-1879; NR 58 TC 21 Z9 21 U1 0 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 JUL PY 1991 VL 228 BP 275 EP 293 DI 10.1017/S0022112091002707 PG 19 WC Mechanics; Physics, Fluids & Plasmas SC Mechanics; Physics GA FZ151 UT WOS:A1991FZ15100010 ER PT J AU LEACH, F ARMSTRONG, GA HEARST, JE AF LEACH, F ARMSTRONG, GA HEARST, JE TI PHOTOSYNTHETIC GENES IN RHODOBACTER-CAPSULATUS CAN BE REGULATED BY OXYGEN DURING DARK RESPIRATORY GROWTH WITH DIMETHYLSULFOXIDE SO JOURNAL OF GENERAL MICROBIOLOGY LA English DT Article ID BACTERIUM RHODOPSEUDOMONAS-CAPSULATA; TRIMETHYLAMINE-N-OXIDE; PIGMENT-BINDING PROTEINS; ELECTRON-TRANSPORT; BACTERIOCHLOROPHYLL BIOSYNTHESIS; CAROTENOID BIOSYNTHESIS; RIBOSOMAL-RNA; R-CAPSULATA; DIMETHYLSULFOXIDE; EXPRESSION AB In the purple non-sulphur bacterium Rhodobacter capsulatus, genes encoding structural polypeptides of the light-harvesting (LH) and reaction center (RC) complexes incorporated into an intracytoplasmic photosynthetic membrane are induced upon lowering the oxygen tension in the media of aerobically growing cultures. When cultures are grown microaerophilically in the dark, an intracytoplasmic photosynthetic membrane develops gratuitously if a terminal oxidant, such as dimethylsulphoxide (DMSO) is present in the medium. The purpose of the present study was to determine whether in these conditions, photosynthetic genes are completely derepressed or whether they are still inducible in response to a lowering of oxygen tension. Oxygen induction of mRNA for the puf and puc operons was compared in dark aerobic cultures (20% O2) shifted to low oxygen conditions (3% O2) allowing growth microaerophilically with or without DMSO as an accessory terminal oxidant. The extent of the induction was similar in both growth conditions, 6 to 12-fold for pufA mRNA and at least 400-fold for pucB mRNA which encode the light-harvesting I (LHI-alpha) and light-harvesting II (LHII-beta) polypeptides, respectively. The puf and puc operons were also induced by low oxygen tension in a mutant strain blocked in an early step of bacteriochlorophyll (BChl) synthesis, suggesting that the presence of BChl may not be a prerequisite for the normal oxygen regulation of the genes encoding the structural polypeptides of the photosynthetic apparatus. C1 UNIV CALIF BERKELEY LAWRENCE BERKELEY LAB,CHEM BIODYNAM LAB,BERKELEY,CA 94720. UNIV CALIF BERKELEY,DEPT CHEM,BERKELEY,CA 94720. NR 33 TC 4 Z9 4 U1 0 U2 1 PU SOC GENERAL MICROBIOLOGY PI READING PA HARVEST HOUSE 62 LONDON ROAD, READING, BERKS, ENGLAND RG1 5AS SN 0022-1287 J9 J GEN MICROBIOL JI J. Gen. Microbiol. PD JUL PY 1991 VL 137 BP 1551 EP 1556 PN 7 PG 6 WC Microbiology SC Microbiology GA FX602 UT WOS:A1991FX60200014 ER PT J AU LUI, ATY CHANG, CL MANKOFSKY, A WONG, HK WINSKE, D AF LUI, ATY CHANG, CL MANKOFSKY, A WONG, HK WINSKE, D TI A CROSS-FIELD CURRENT INSTABILITY FOR SUBSTORM EXPANSIONS SO JOURNAL OF GEOPHYSICAL RESEARCH-SPACE PHYSICS LA English DT Article ID HYBRID-DRIFT INSTABILITY; COLLISIONLESS TEARING INSTABILITY; PLASMA SHEET; MAGNETOSPHERIC SUBSTORMS; NEUTRAL SHEET; STREAMING INSTABILITY; THERMAL CATASTROPHE; GEOMAGNETIC TAIL; GROWTH-PHASE; SOLAR-WIND AB We investigate a cross-field current instability (CFCI) as a candidate for current disruption during substorm expansions. The numerical solution of the linear dispersion equation indicates that (1) the proposed instability can occur at the inner edge or the midsection of the neutral sheet just prior to the substorm expansion onset although the former environment is found more favorable at the same drift speed scaled to the ion thermal speed, (2) the computed growth time is comparable to the substorm onset time, and (3) the excited waves have a mixed polarization with frequencies near the ion gyrofrequency at the inner edge and near the lower hybrid frequency in the midtail region. On the basis of this analysis we propose a substorm development scenario in which plasma sheet thinning during the substorm growth phase leads to an enhancement in the relative drift between ions and electrons. This results in the neutral sheet being susceptible to the CFCI and initiates the diversion of the cross-tail current through the ionosphere. Whether or not a substorm current wedge is ultimately formed is regulated by the ionospheric condition. A large number of substorm features can be readily understood with the proposed scheme. These include (1) precursory activities (pseudobreakups) prior to substorm onset, (2) substorm initiation region to be spatially localized, (3) three different solar wind conditions for substorm occurrence, (4) skew towards evening local times for substorm onset locations, (5) different acceleration characteristics between ions and electrons, (6) tailward spreading of current disruption region after substorm onset, and (7) local time expansion of substorm current wedge with possible discrete westward jump for the evening expansion. C1 SCI APPLICAT INT CORP,MCLEAN,VA. SW RES INST,SAN ANTONIO,TX 78284. UNIV CALIF LOS ALAMOS SCI LAB,LOS ALAMOS,NM 87545. RP LUI, ATY (reprint author), JOHNS HOPKINS UNIV,APPL PHYS LAB,LAUREL,MD 20707, USA. NR 72 TC 191 Z9 195 U1 0 U2 7 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 SN 0148-0227 J9 J GEOPHYS RES JI J. Geophys. Res-Space Phys. PD JUL 1 PY 1991 VL 96 IS A7 BP 11389 EP 11401 DI 10.1029/91JA00892 PG 13 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA FW171 UT WOS:A1991FW17100036 ER PT J AU HESSE, M BIRN, J AF HESSE, M BIRN, J TI MAGNETOSPHERE-IONOSPHERE COUPLING DURING PLASMOID EVOLUTION - 1ST-RESULTS SO JOURNAL OF GEOPHYSICAL RESEARCH-SPACE PHYSICS LA English DT Article ID FIELD; MODEL; MAGNETOTAIL; SUBSTORM; TAIL; FLUX AB The influence of magnetosphere-ionosphere coupling on the dynamic evolution of the magnetotail is investigated by a three-dimensional resistive MHD code that includes the effects of the closure of field-aligned currents in a simple resistive model ionosphere. Particular emphasis is on the role of this coupling during substorm evolution and the modification of the latter by the convection driven by the ionospheric electric fields. For comparison, we present results from a simulation which uses an infinitely conducting ionosphere but is otherwise identical. Comparison of the two simulations shows that the major impact of magnetosphere-ionosphere communication is an acceleration of magnetotail evolution. Otherwise, phenomena in the two models are qualitatively similar. We conclude that ionospheric effects do not significantly affect substorm associated magnetotail dynamics. RP UNIV CALIF LOS ALAMOS SCI LAB, LOS ALAMOS, NM 87545 USA. RI Hesse, Michael/D-2031-2012 NR 19 TC 24 Z9 24 U1 0 U2 1 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 2169-9380 EI 2169-9402 J9 J GEOPHYS RES-SPACE JI J. Geophys. Res-Space Phys. PD JUL 1 PY 1991 VL 96 IS A7 BP 11513 EP 11522 DI 10.1029/91JA00440 PG 10 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA FW171 UT WOS:A1991FW17100045 ER PT J AU HOSHINO, M AF HOSHINO, M TI FORCED MAGNETIC RECONNECTION IN A PLASMA SHEET WITH LOCALIZED RESISTIVITY PROFILE EXCITED BY LOWER HYBRID DRIFT TYPE INSTABILITY SO JOURNAL OF GEOPHYSICAL RESEARCH-SPACE PHYSICS LA English DT Article ID TEARING MODE; NEUTRAL SHEET; MAGNETOTAIL; GROWTH; ACCELERATION; SIMULATION; EVOLUTION; EXPANSION; DIFFUSION AB A forced magnetic reconnection process with a temporal evolution of resistivity is studied for a plasma sheet with a nonuniform resistivity profile based on the nonlocal mode structure of the lower hybrid drift type instability. The growth rate of the mode found is almost independent of the resistivity at the neutral sheet, but depends on the resistivity of the region of maximum density gradient away from the neutral sheet. We study this by using both a nonlinear numerical MHD simulation and a linear theory. The mode may be relevant to the prevalent theoretical concept of MHD reconnection and the localized anomalous resistivity profile based on the lower hybrid drift instability. C1 UNIV CALIF LAWRENCE LIVERMORE NATL LAB,INST GEOPHYS & PLANETARY PHYS,LIVERMORE,CA 94550. NR 48 TC 30 Z9 30 U1 0 U2 0 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 SN 0148-0227 J9 J GEOPHYS RES JI J. Geophys. Res-Space Phys. PD JUL 1 PY 1991 VL 96 IS A7 BP 11555 EP 11567 DI 10.1029/91JA00984 PG 13 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA FW171 UT WOS:A1991FW17100048 ER PT J AU THOMAS, VA WINSKE, D THOMSEN, MF ONSAGER, TG AF THOMAS, VA WINSKE, D THOMSEN, MF ONSAGER, TG TI HYBRID SIMULATION OF THE FORMATION OF A HOT FLOW ANOMALY SO JOURNAL OF GEOPHYSICAL RESEARCH-SPACE PHYSICS LA English DT Note ID EARTHS BOW SHOCK; DIAMAGNETIC CAVITIES UPSTREAM; PLASMA STRUCTURES; CURRENT SHEET; SOLAR-WIND; REFLECTION AB Results are presented from two-dimensional hybrid simulations of the interaction of a supercritical quasi-perpendicular collisionless shock wave with current sheets embedded in the upstream flow. The current sheet normals are perpendicular to the shock normal. When the motional electric field is directed toward the discontinuity, the interaction leads to the generation of a region with high ion temperature, low magnetic field, and low density, which has many properties of a class of events variously referred to as active current sheets, hot diamagnetic cavities, or hot flow anomalies (HFAs). The simulations demonstrate that the HFA results from the interaction of ions reflected at the shock with the current sheet. The interaction does not involve an instability and is not caused by the collision of the current sheet and the shock but rather is a property of a shock with an embedded current sheet. The simulations suggest that the HFAs formed in this way are always attached to the shock and extend into both the upstream and downstream regions. RP THOMAS, VA (reprint author), UNIV CALIF LOS ALAMOS SCI LAB,LOS ALAMOS,NM 87545, USA. NR 18 TC 66 Z9 67 U1 0 U2 3 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 SN 0148-0227 J9 J GEOPHYS RES JI J. Geophys. Res-Space Phys. PD JUL 1 PY 1991 VL 96 IS A7 BP 11625 EP 11632 DI 10.1029/91JA01092 PG 8 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA FW171 UT WOS:A1991FW17100054 ER PT J AU LENHARD, RJ PARKER, JC MISHRA, S AF LENHARD, RJ PARKER, JC MISHRA, S TI ON THE CORRESPONDENCE BETWEEN BROOKS-COREY AND VANGENUTCHEN MODELS - CLOSURE SO JOURNAL OF IRRIGATION AND DRAINAGE ENGINEERING-ASCE LA English DT Discussion RP LENHARD, RJ (reprint author), PACIFIC NW LAB, K6-77, POB 999, RICHLAND, WA 99352 USA. NR 0 TC 0 Z9 0 U1 0 U2 3 PU ASCE-AMER SOC CIVIL ENG PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017-2398 SN 0733-9437 J9 J IRRIG DRAIN E-ASCE JI J. Irrig. Drainage Eng-ASCE PD JUL-AUG PY 1991 VL 117 IS 4 BP 610 EP 611 DI 10.1061/(ASCE)0733-9437(1991)117:4(610.2) PG 2 WC Agricultural Engineering; Engineering, Civil; Water Resources SC Agriculture; Engineering; Water Resources GA FY416 UT WOS:A1991FY41600017 ER PT J AU HANNERS, J GIBSON, R VELARDE, K HAMMER, J ALVAREZ, M GRIEGO, J UNKEFER, CJ AF HANNERS, J GIBSON, R VELARDE, K HAMMER, J ALVAREZ, M GRIEGO, J UNKEFER, CJ TI STEREOSELECTIVE SYNTHESIS OF STABLE ISOTOPE-LABELED L-ALPHA-AMINO ACIDS - BIOSYNTHESIS OF H-2-LABELED, C-13-LABELED, AND N-15-LABELED L-SERINES SO JOURNAL OF LABELLED COMPOUNDS & RADIOPHARMACEUTICALS LA English DT Article DE L-[1-C-13]SERINE; L-[2-C-13]SERINE; L-[3-C-13]SERINE; L-[2,3-C-13(2)]SERINE; L-[3-H-2(2), C-13]SERINE ID EFFICIENT; METHANOL; GLYCINE; GROWTH AB We have developed a stereospecific biosynthesis of C-13 and N-15-labeled L-serine which involves the serine-type methylotroph Methylobacterium extorquens AM1. In this biosynthesis, C-3 of serine is derived from methanol while C-2, C-1 and the a-amino group are derived from glycine. By starting with the appropriate labeling precursor, we can produce any of the H-2, C-13 and/or N-15 isotopomers of L-serine. Using a 5-L culture, 40-50 millimoles of L-serine are produced; L-serine and glycine are recovered from the growth medium and then separated chromatographically. C1 LOS ALAMOS NATL LAB,NATL STABLE ISOTOPES RESOURCE,INC-4 GRP,MS C345,LOS ALAMOS,NM 87545. NR 23 TC 11 Z9 11 U1 0 U2 0 PU JOHN WILEY & SONS LTD PI W SUSSEX PA BAFFINS LANE CHICHESTER, W SUSSEX, ENGLAND PO19 1UD SN 0362-4803 J9 J LABELLED COMPD RAD JI J. Label. Compd. Radiopharm. PD JUL PY 1991 VL 29 IS 7 BP 781 EP 790 DI 10.1002/jlcr.2580290708 PG 10 WC Biochemical Research Methods; Chemistry, Medicinal; Chemistry, Analytical SC Biochemistry & Molecular Biology; Pharmacology & Pharmacy; Chemistry GA FV483 UT WOS:A1991FV48300006 ER PT J AU WOS, L MCCUNE, W AF WOS, L MCCUNE, W TI AUTOMATED THEOREM-PROVING AND LOGIC PROGRAMMING - A NATURAL SYMBIOSIS SO JOURNAL OF LOGIC PROGRAMMING LA English DT Article AB We present a detailed review of the elements of automated theorem proving, emphasizing certain aspects of especial interest to the logic programming community. In particular, we focus heavily on how an automated theorem-proving program can treat equality in a natural and yet effective manner, and how such a program can use strategy to control its reasoning in a sophisticated fashion. With the objective of significantly increasing the scope of logic programming, perhaps some unusually inventive researcher can adapt various procedures we review in this article, and adapt them in a way that preserves most of the speed offered by logic programming. In turn, although our expertise rests far more in automated theorem proving, we include certain observations concerning the value of logic programming to automated theorem proving in general. In other words, a natural symbiosis between automated theorem proving and logic programming exists, which nicely completes the circle, since logic programming was born of automated theorem proving. C1 ARGONNE NATL LAB,DIV MATH & COMP SCI,ARGONNE,IL 60439. NR 42 TC 3 Z9 3 U1 0 U2 0 PU ELSEVIER SCIENCE INC PI NEW YORK PA 655 AVENUE OF THE AMERICAS, NEW YORK, NY 10010 SN 0743-1066 J9 J LOGIC PROGRAM JI J. Log. Program. PD JUL PY 1991 VL 11 IS 1 BP 1 EP 53 DI 10.1016/0743-1066(91)90008-D PG 53 WC Computer Science, Theory & Methods SC Computer Science GA FV252 UT WOS:A1991FV25200001 ER PT J AU FISHER, RA MARCENAT, C PHILLIPS, NE HAEN, P LAPIERRE, F LEJAY, P FLOUQUET, J VOIRON, J AF FISHER, RA MARCENAT, C PHILLIPS, NE HAEN, P LAPIERRE, F LEJAY, P FLOUQUET, J VOIRON, J TI THE MAGNETIC INSTABILITY IN THE HEAVY FERMION COMPOUNDS CE1-XLAXRU2SI2 SO JOURNAL OF LOW TEMPERATURE PHYSICS LA English DT Article ID LOW-TEMPERATURE PROPERTIES; HIGH-FIELD MAGNETIZATION; TRANSPORT-PROPERTIES; METAMAGNETIC TRANSITION; SYSTEM CERU2SI2; LA RU2SI2; CEAL3; UPT3; (CE,LA)RU2SI2; FLUCTUATIONS AB The magnetization and the specific heat of Ce1-xLa(x)Ru2Si2 with x less-than-or-equal-to 0.13 are reported with special attention to the effect of magnetic field and the role of lanthanum doping. Evidence is given of differences between the undoped (x = 0) and the solid solution (x not-equal 0) cases. A common feature is the occurrence of well-defined anomalies in the magnetization at the "metamagnetic" field H(M) independently of whether the ground state is one of long-range order or Pauli paramagnetism. For x = 0, the ground state appears to be a Pauli paramagnet for any strength of the magnetic field; quantum fluctuations or deviations from an ideal lattice may prevent the occurrence of a true static magnetic transition. C1 UNIV GRENOBLE 1,CTR RECH TRES BASSES TEMP,CNRS,F-38041 GRENOBLE,FRANCE. UNIV GRENOBLE 1,LAB LOUIS NEEL,CNRS,F-38041 GRENOBLE,FRANCE. RP FISHER, RA (reprint author), UNIV CALIF BERKELEY LAWRENCE BERKELEY LAB,DIV MAT & CHEM SCI,BERKELEY,CA 94720, USA. NR 69 TC 82 Z9 82 U1 0 U2 12 PU PLENUM PUBL CORP PI NEW YORK PA 233 SPRING ST, NEW YORK, NY 10013 SN 0022-2291 J9 J LOW TEMP PHYS JI J. Low Temp. Phys. PD JUL PY 1991 VL 84 IS 1-2 BP 49 EP 86 DI 10.1007/BF00681617 PG 38 WC Physics, Applied; Physics, Condensed Matter SC Physics GA GA351 UT WOS:A1991GA35100004 ER PT J AU ROBINSON, RA LAWSON, AC BUSCHOW, KHJ DEBOER, FR SECHOVSKY, V VONDREELE, RB AF ROBINSON, RA LAWSON, AC BUSCHOW, KHJ DEBOER, FR SECHOVSKY, V VONDREELE, RB TI LOW-TEMPERATURE MAGNETIC-STRUCTURES OF UPDSN SO JOURNAL OF MAGNETISM AND MAGNETIC MATERIALS LA English DT Article ID UNISN AB The intermetallic compound UPdSn has been studied by means of dc magnetic susceptibility and neutron diffraction. While it has been assumed in previous work that the space group is P6(3)/mmc and there is disorder between the Pd and Sn atoms, we find a significantly better fit to our data with the related space group P6(3)mc which allows Pd/Sn ordering. There are two magnetic phase transitions at approximately 25 and 40 K. Above 40 K, there is no long-range magnetic order, but between 25 and 40 K, a canted antiferromagnetic structure forms, in which the moments lie in, or close to, the y-z-plane of a double-sized orthorhombic cell, with an angle of approximately 54-degrees away from the z-axis. Below 25 K, the moments rotate out of the y-z-plane by approximately 45-degrees to form a second related non-collinear structure. At the lowest temperature measured, the uranium moment is (2.05 +/- 0.13)-mu-B. C1 PHILIPS RES LABS,5600 JA EINDHOVEN,NETHERLANDS. UNIV AMSTERDAM,NATUURKUNDIG LAB,1018 XE AMSTERDAM,NETHERLANDS. CHARLES UNIV,CS-12116 PRAGUE 2,CZECHOSLOVAKIA. RP ROBINSON, RA (reprint author), UNIV CALIF LOS ALAMOS SCI LAB,LOS ALAMOS,NM 87545, USA. RI Sechovsky, Vladimir/A-5256-2008 OI Sechovsky, Vladimir/0000-0003-1298-2120 NR 23 TC 38 Z9 38 U1 0 U2 0 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 JUL PY 1991 VL 98 IS 1-2 BP 147 EP 154 DI 10.1016/0304-8853(91)90439-H PG 8 WC Materials Science, Multidisciplinary; Physics, Condensed Matter SC Materials Science; Physics GA GA324 UT WOS:A1991GA32400024 ER PT J AU ARMES, SP GOTTESFELD, S BEERY, JG GARZON, F MOMBOURQUETTE, C HAWLEY, M KUHN, HH AF ARMES, SP GOTTESFELD, S BEERY, JG GARZON, F MOMBOURQUETTE, C HAWLEY, M KUHN, HH TI CHARACTERIZATION OF CONDUCTING POLYMER QUARTZ COMPOSITES SO JOURNAL OF MATERIALS CHEMISTRY LA English DT Article DE POLYPYRROLE; CONDUCTING POLYMER; ORGANIC INORGANIC COMPOSITE ID POLYPYRROLE AB We have characterized several polypyrrole-quartz and polyaniline-quartz composites over a range of conducting-polymer loading levels by thermogravimetric analysis (TG), Rutherford backscattering spectrometry (RBS), scanning electron microscopy (SEM), scanning tunnelling microscopy (STM) and conductivity measurements. It is shown that the conducting polymer overlayers are remarkably thin and uniform; film thicknesses were determined independently by TG and RBS and are in close agreement. The film thickness of one of the polypyrrole-quartz samples was used to obtain the first direct of the conductivity of the polypyrrole component (ca. 35 OMEGA-1 cm-1). C1 UNIV CALIF LOS ALAMOS SCI LAB,ELECTR RES GRP,LOS ALAMOS,NM 87545. UNIV CALIF LOS ALAMOS SCI LAB,DIV MAT SCI & TECHNOL,LOS ALAMOS,NM 87545. MILLIKEN RES CORP,SPARTANBURG,SC 29304. RP ARMES, SP (reprint author), UNIV SUSSEX,SCH CHEM & MOLEC SCI,BRIGHTON BN1 9QJ,E SUSSEX,ENGLAND. OI Armes, Steven/0000-0002-8289-6351 NR 18 TC 16 Z9 16 U1 0 U2 2 PU ROYAL SOC CHEMISTRY PI CAMBRIDGE PA THOMAS GRAHAM HOUSE, SCIENCE PARK MILTON ROAD, CAMBRIDGE, CAMBS, ENGLAND CB4 4WF SN 0959-9428 J9 J MATER CHEM JI J. Mater. Chem. PD JUL PY 1991 VL 1 IS 4 BP 525 EP 529 DI 10.1039/jm9910100525 PG 5 WC Chemistry, Physical; Materials Science, Multidisciplinary SC Chemistry; Materials Science GA FY353 UT WOS:A1991FY35300006 ER PT J AU BHATTACHARYA, RN PARILLA, PA MASON, A ROYBAL, LL AHRENKIEL, RK NOUFI, R HELLMER, RP KWAK, JF GINLEY, DS AF BHATTACHARYA, RN PARILLA, PA MASON, A ROYBAL, LL AHRENKIEL, RK NOUFI, R HELLMER, RP KWAK, JF GINLEY, DS TI TLBACACUO AND YBACUO SUPERCONDUCTOR THIN-FILMS VIA AN ELECTRODEPOSITION PROCESS SO JOURNAL OF MATERIALS RESEARCH LA English DT Note AB Thin-film superconductors of TlBaCaCuO (TBCCO) and YBaCuO (YBCO) were fabricated via an electrodeposition process. The precursors of the superconducting TBCCO films were codeposited at a constant potential of -4 V onto a silver-coated SrTiO3 substrate. The YBCO precursors also were codeposited but under pulsed-potential conditions (in order to improve the film morphology) and onto a silver-coated MgO substrate. The pulsed-potential cycle consisted of 1 s at -4 V followed by 1 s at -1 V. The post-annealed TBCCO film showed zero resistance at about 102 K and critical current density at 76 K of 20 000 A/cm2 in zero magnetic field and 5000 A/cm2 in a 10 kOe field parallel to the film plane. The post-annealed YBCO film showed zero resistance at approximately 80 K and critical current density of 5160 A/cm2 at 4 K in zero magnetic field. C1 SANDIA NATL LABS,ALBUQUERQUE,NM 87185. RP BHATTACHARYA, RN (reprint author), SOLAR ENERGY RES INST,GOLDEN,CO 80401, USA. NR 6 TC 27 Z9 27 U1 0 U2 1 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 JUL PY 1991 VL 6 IS 7 BP 1389 EP 1392 DI 10.1557/JMR.1991.1389 PG 4 WC Materials Science, Multidisciplinary SC Materials Science GA FV269 UT WOS:A1991FV26900001 ER PT J AU COOPER, EA GANGOPADHYAY, AK MASON, TO BALACHANDRAN, U AF COOPER, EA GANGOPADHYAY, AK MASON, TO BALACHANDRAN, U TI CO-2 DECOMPOSITION KINETICS OF YBA2CU3O7-X VIA INSITU ELECTRICAL-CONDUCTIVITY MEASUREMENTS SO JOURNAL OF MATERIALS RESEARCH LA English DT Article ID CARBON; CO2 AB In situ electrical conductivity measurements were employed to study the kinetics of decomposition of YBa2Cu3O7-x in flowing 5% CO2/95% O2 atmosphere at 815-degrees-C. Three regimes could be observed in the decay of the conductivity with time, interpreted as corresponding to nucleation over the initial 5 - 10 min, rapid formation of Y2Cu2O5, BaCO3, and CuO between 10 min and 1 h, and finally transition to the formation of Y2BaCuO5, BaCO3, and CuO at longer times. The absence of dispersion in impedance measurements as a function of frequency together with the gradual decay of conductivity (roughly corresponding to the remaining volume fraction of YBa2Cu3O7-x) indicates that not all grain boundaries are involved in the decomposition process. C1 ARGONNE NATL LAB,DIV MAT & COMPONENTS TECHNOL,ARGONNE,IL 60439. ARGONNE NATL LAB,SCI & TECHNOL CTR SUPERCOND,ARGONNE,IL 60439. RP COOPER, EA (reprint author), NORTHWESTERN UNIV,CTR SUPERCOND,DEPT MAT SCI & ENGN & SCI & TECHNOL,EVANSTON,IL 60208, USA. RI Mason, Thomas/B-7528-2009 NR 15 TC 7 Z9 7 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 JUL PY 1991 VL 6 IS 7 BP 1393 EP 1397 DI 10.1557/JMR.1991.1393 PG 5 WC Materials Science, Multidisciplinary SC Materials Science GA FV269 UT WOS:A1991FV26900002 ER PT J AU KIM, HE KIMREY, HD KIM, DJ AF KIM, HE KIMREY, HD KIM, DJ TI MICROWAVE SINTERING OF YBA2CU3OX SUPERCONDUCTORS SO JOURNAL OF MATERIALS SCIENCE LETTERS LA English DT Article RP KIM, HE (reprint author), OAK RIDGE NATL LAB,DIV MET & CERAM,OAK RIDGE,TN 37831, USA. NR 11 TC 5 Z9 5 U1 0 U2 0 PU CHAPMAN HALL LTD PI LONDON PA 2-6 BOUNDARY ROW, LONDON, ENGLAND SE1 8HN SN 0261-8028 J9 J MATER SCI LETT JI J. Mater. Sci. Lett. PD JUL 1 PY 1991 VL 10 IS 13 BP 742 EP 744 DI 10.1007/BF00723264 PG 3 WC Materials Science, Multidisciplinary SC Materials Science GA FX074 UT WOS:A1991FX07400002 ER PT J AU LAIRD, G KENNEDY, TC AF LAIRD, G KENNEDY, TC TI THE ROLE OF INTERFACIAL COHESION OF THE MICROMECHANICS OF COMPOSITES CONTAINING SPHERICAL INCLUSIONS SO JOURNAL OF MATERIALS SCIENCE LETTERS LA English DT Article C1 OREGON STATE UNIV,DEPT MECH ENGN,CORVALLIS,OR 97331. RP LAIRD, G (reprint author), US BUR MINES,ALBANY RES CTR,ALBANY,OR 97321, USA. NR 10 TC 0 Z9 0 U1 0 U2 0 PU CHAPMAN HALL LTD PI LONDON PA 2-6 BOUNDARY ROW, LONDON, ENGLAND SE1 8HN SN 0261-8028 J9 J MATER SCI LETT JI J. Mater. Sci. Lett. PD JUL 1 PY 1991 VL 10 IS 13 BP 772 EP 773 DI 10.1007/BF00723276 PG 2 WC Materials Science, Multidisciplinary SC Materials Science GA FX074 UT WOS:A1991FX07400014 ER PT J AU BROWN, RW CONVERY, ME DELANEY, DB AF BROWN, RW CONVERY, ME DELANEY, DB TI PRODUCT REPRESENTATION FOR THE HARMONIC SERIES OF A UNIT VECTOR SO JOURNAL OF MATHEMATICAL PHYSICS LA English DT Article ID COSMIC STRINGS AB A representation is found for the finite Fourier series of a vector whereby any constant constraint on its magnitude is completely solved and automatically satisfied. The representation is a product of rotations, one set for each harmonic, such that the independent degrees of freedom are identified as rotational angles. Examples for the first few harmonics are presented. A recursive procedure is found whereby one can relate the standard Fourier coefficients to the angles. C1 UNIV CALIF LOS ALAMOS SCI LAB,LOS ALAMOS,NM 87545. RP BROWN, RW (reprint author), CASE WESTERN RESERVE UNIV,DEPT PHYS,CLEVELAND,OH 44106, USA. NR 10 TC 6 Z9 6 U1 0 U2 0 PU AMER INST PHYSICS PI WOODBURY PA CIRCULATION FULFILLMENT DIV, 500 SUNNYSIDE BLVD, WOODBURY, NY 11797-2999 SN 0022-2488 J9 J MATH PHYS JI J. Math. Phys. PD JUL PY 1991 VL 32 IS 7 BP 1674 EP 1682 DI 10.1063/1.529279 PG 9 WC Physics, Mathematical SC Physics GA FU115 UT WOS:A1991FU11500003 ER PT J AU CHAU, LL SHAW, JC YEN, HC AF CHAU, LL SHAW, JC YEN, HC TI AN ALTERNATIVE EXPLICIT CONSTRUCTION OF N-SOLITON SOLUTIONS IN 1+1 DIMENSIONS SO JOURNAL OF MATHEMATICAL PHYSICS LA English DT Article ID NONLINEAR-EVOLUTION EQUATIONS; SINE-GORDON EQUATION; BACKLUND-TRANSFORMATIONS AB Using the special Riemann-problem technique of Zakharov et al. [Sov. Phys. JETP 47, 1017 (1978)], an explicit N-step Backlund transformation is derived for a class of 1 + 1-dimensional nonlinear evolution equations, thus providing an alternative explicit expression of their N-soliton solutions which no longer involves computations of the intermediate solutions, nor leaves any expansion of N x N determinants (and their differentiation) to be done. C1 UNIV CALIF LOS ALAMOS SCI LAB,LOS ALAMOS,NM 87545. NATL CHIAO TUNG UNIV,DEPT APPL MATH,HSINCHU,TAIWAN. NATL TSING HUA UNIV,DEPT PHYS,HSINCHU 300,TAIWAN. RP CHAU, LL (reprint author), UNIV CALIF DAVIS,DEPT PHYS,DAVIS,CA 95616, USA. NR 18 TC 36 Z9 36 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 JUL PY 1991 VL 32 IS 7 BP 1737 EP 1743 DI 10.1063/1.529235 PG 7 WC Physics, Mathematical SC Physics GA FU115 UT WOS:A1991FU11500011 ER PT J AU COOLING, BF AF COOLING, BF TI THE ARMY NUCLEAR-POWER PROGRAM - THE EVOLUTION OF A SUPPORT AGENCY - SUID,LH SO JOURNAL OF MILITARY HISTORY LA English DT Book Review RP COOLING, BF (reprint author), US DOE,WASHINGTON,DC 20545, USA. NR 1 TC 0 Z9 0 U1 0 U2 0 PU VIRGINIA MILITARY INST PI LEXINGTON PA LEXINGTON, VA 24450 SN 0899-3718 J9 J MILITARY HIST JI J. Mil. Hist. PD JUL PY 1991 VL 55 IS 3 BP 423 EP 424 DI 10.2307/1985699 PG 2 WC History SC History GA FV764 UT WOS:A1991FV76400019 ER PT J AU BROWN, JM RADFORD, HE SEARS, TJ AF BROWN, JM RADFORD, HE SEARS, TJ TI AVOIDED CROSSINGS IN THE FAR-INFRARED LASER MAGNETIC-RESONANCE SPECTRUM OF HCO SO JOURNAL OF MOLECULAR SPECTROSCOPY LA English DT Article ID ASYMMETRIC-TOP MOLECULES; ZEEMAN LEVEL-CROSSINGS; GROUND-STATE; LMR SPECTRA; GAS-PHASE; SPECTROSCOPY; HO2; PARAMETERS; AVOIDANCE; RADICALS C1 HARVARD SMITHSONIAN CTR ASTROPHYS,CTR ASTROPHYS,CAMBRIDGE,MA 02138. BROOKHAVEN NATL LAB,UPTON,NY 11973. RP BROWN, JM (reprint author), PHYS CHEM LAB,S PARKS RD,OXFORD OX1 3QZ,ENGLAND. RI Sears, Trevor/B-5990-2013 OI Sears, Trevor/0000-0002-5559-0154 NR 36 TC 38 Z9 38 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 0022-2852 J9 J MOL SPECTROSC JI J. Mol. Spectrosc. PD JUL PY 1991 VL 148 IS 1 BP 20 EP 37 DI 10.1016/0022-2852(91)90031-5 PG 18 WC Physics, Atomic, Molecular & Chemical; Spectroscopy SC Physics; Spectroscopy GA FR895 UT WOS:A1991FR89500003 ER PT J AU CHASON, E AZIZ, MJ AF CHASON, E AZIZ, MJ TI EFFECT OF PRESSURE ON CRYSTALLIZATION KINETICS OF CORDIERITE GLASS SO JOURNAL OF NON-CRYSTALLINE SOLIDS LA English DT Article ID VISCOSITY; RAMAN; MELT; MECHANISM; SILICA; ALBITE; SI AB The effect of pressure on the crystal growth rate and bulk nucleation rate of cordierite (2MgO.2Al2O3.5SiO2) in glass of the stoichiometric composition was measured. The crystal nucleation barrier was eliminated by seeding the surface of the cordierite glass with crystals. Crystal growth kinetics were determined independently from the nucleation kinetics by comparing the amount of surface seeded crystal growth and bulk-nucleated growth. Time dependence of crystal growth changes from linear at low pressure (0-2 kbar) to square root of time at high pressure (> 5 kbar). In both regimes of growth, increasing pressure was found to retard the crystal growth rate and increase bulk nucleation time. The pressure effect is discussed in terms of structure and transport properties in cordierite and in other silicates melts and glasses. C1 HARVARD UNIV,DIV APPL SCI,CAMBRIDGE,MA 02138. RP CHASON, E (reprint author), SANDIA NATL LABS,ALBUQUERQUE,NM 87185, USA. NR 27 TC 10 Z9 10 U1 0 U2 0 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 JUL PY 1991 VL 130 IS 2 BP 204 EP 210 DI 10.1016/0022-3093(91)90456-G PG 7 WC Materials Science, Ceramics; Materials Science, Multidisciplinary SC Materials Science GA FY043 UT WOS:A1991FY04300008 ER PT J AU ITOH, N TANAKA, T CLINARD, FW AF ITOH, N TANAKA, T CLINARD, FW TI FORMATION OF METASTABLE DEFECTS UNDER IRRADIATION OF CERAMICS SO JOURNAL OF NUCLEAR MATERIALS LA English DT Article ID SELF-TRAPPED EXCITON; RADIATION-INDUCED CONDUCTIVITY; ELECTRONIC EXCITATION; LATTICE-DEFECTS; ALKALI-HALIDES; AL2O3; SIO2; KBR; CREATION; CRYSTALS AB Possible change in electrical conductivity and dielectric loss factor in ceramics under ionizing irradiation has been evaluated. First, evidence for formation of transient lattice defects by ionizing irradiation is presented and their yield is evaluated. Then the contributions of the transient defects as well as electron-hole pairs to the electrical conductivity and dielectric loss factor are compared and it is pointed out that the electron-hole pairs make a major contribution to the electrical conductivity, while the contribution to the high-frequency dielectric loss factor is dominated by the transient defects. A model calculation of the conductivity and dielectric loss factor under irradiation for Al2O3 is presented. C1 UNIV CALIF LOS ALAMOS SCI LAB,LOS ALAMOS,NM 87545. RP ITOH, N (reprint author), NAGOYA UNIV,FAC SCI,DEPT PHYS,FURO CHO,NAGOYA 46401,JAPAN. NR 38 TC 7 Z9 7 U1 0 U2 1 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 JUL PY 1991 VL 183 IS 1-2 BP 25 EP 32 DI 10.1016/0022-3115(91)90467-L PG 8 WC Materials Science, Multidisciplinary; Nuclear Science & Technology SC Materials Science; Nuclear Science & Technology GA FT840 UT WOS:A1991FT84000004 ER PT J AU ZOCCO, TG SHELDON, RI RIZZO, HF AF ZOCCO, TG SHELDON, RI RIZZO, HF TI TWINNING IN MONOCLINIC BETA-PHASE PLUTONIUM SO JOURNAL OF NUCLEAR MATERIALS LA English DT Article AB Twinning has been investigated in body-centered monoclinic beta-phase plutonium by Transmission Electron Microscopy (TEM). A triode sputtering system was used to produce single-phase thick films of room temperature stabilized beta-phase metal. General examination of the microstructure revealed a very fine grain size (approximately 100 nm) and the presence of twins. As expected in a fine grained metal, the dislocation density was low. Morphologically the twins appeared much like annealing twins observed in many metals and alloys, however, the formation of twins may have been due to deformation, growth or transformation processes. The definitive mode of formation has not been established, although classical deformation twinning theory was used to interpret the crystallography of the observed twins. Close inspection of the twins using microdiffraction revealed the individual parent/twin orientations. Crystallographic analysis of the electron diffraction patterns showed that Type II twinning appears to predominate, with a common orientation relationship between parent and twins described as a two-fold rotation axis about the [110] shear direction (eta-1). Further work is in progress to theoretically predict the complete twinning systems for beta-phase plutonium. C1 UNIV CALIF LOS ALAMOS SCI LAB,DIV NUCL MAT TECHNOL,MS E502,LOS ALAMOS,NM 87545. UNIV CALIF LAWRENCE LIVERMORE NATL LAB,DEPT CHEM & MAT SCI,LIVERMORE,CA 94550. RP ZOCCO, TG (reprint author), UNIV CALIF LOS ALAMOS SCI LAB,DIV MAT SCI & TECHNOL,MS G730,LOS ALAMOS,NM 87545, USA. NR 16 TC 5 Z9 5 U1 2 U2 6 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 JUL PY 1991 VL 183 IS 1-2 BP 80 EP 88 DI 10.1016/0022-3115(91)90474-L PG 9 WC Materials Science, Multidisciplinary; Nuclear Science & Technology SC Materials Science; Nuclear Science & Technology GA FT840 UT WOS:A1991FT84000011 ER PT J AU GIBAUD, A SHAPIRO, SM GESLAND, JY AF GIBAUD, A SHAPIRO, SM GESLAND, JY TI KINETICS OF THE LOCK-IN PHASE-TRANSITION IN RB2ZNCL4 SO JOURNAL OF PHYSICS-CONDENSED MATTER LA English DT Article ID INCOMMENSURATE PHASE; NEUTRON-SCATTERING; THERMAL HYSTERESIS; X-RAY; TRANSFORMATION; BEHAVIOR; K2ZNCL4 AB High-resolution x-ray scattering experiments have been performed on single crystals of the incommensurate system Rb2ZnCl4 with emphasis on the kinetics of the lock-in phase transition. The nearly perfect single crystal (mosaic spread congruent-to 0.6 min) displayed a large hysteresis of 20 K. As the sample was cooled quickly from the paraelectric phase into the commensurate phase, via the incommensurate phase, the time evolution of the disappearance of the incommensurate peak intensity was monitored. The time becomes longer when the sample is quenched to lower than the lock-in temperature, which is contrary to the expected kinetic behaviour of nucleation and growth. The characteristic time of decay exhibits an Arrhenius-like behaviour with an energetic barrier E(b) to overcome of the order of 0.37 eV. The origin of the energetic barrier is interpreted in terms of an order-disorder process of the ZnCl4 tetrahedra network. C1 UNIV MAINE,FAC SCI,CNRS,URA 807,F-72017 LE MANS,FRANCE. RP GIBAUD, A (reprint author), BROOKHAVEN NATL LAB,DEPT PHYS,BLDG 510,UPTON,NY 11973, USA. NR 15 TC 5 Z9 5 U1 0 U2 0 PU IOP PUBLISHING LTD PI BRISTOL PA TECHNO HOUSE, REDCLIFFE WAY, BRISTOL, ENGLAND BS1 6NX SN 0953-8984 J9 J PHYS-CONDENS MAT JI J. Phys.-Condes. Matter PD JUL 1 PY 1991 VL 3 IS 26 BP 4817 EP 4824 DI 10.1088/0953-8984/3/26/005 PG 8 WC Physics, Condensed Matter SC Physics GA FV487 UT WOS:A1991FV48700005 ER PT J AU DOSS, E ROY, G AF DOSS, E ROY, G TI FLOW CHARACTERISTICS INSIDE MHD SEAWATER THRUSTERS SO JOURNAL OF PROPULSION AND POWER LA English DT Article AB A three-dimensional MHD fluid-flow computer model has been developed and applied to study the concept of MHD seawater propulsion. The effects of strong magnetic fields on the current and electrical fields inside the MHD duct and their interaction with the flowfields, particularly those in the boundary layers, have been investigated. Results of parametric studies for variables influencing the flowfield characteristics and the overall performance of the propulsion systems are discussed. Such parameters include the magnetic field and electrical loading of the MHD thruster. The results of the calculations performed indicate the sensitivity of the thruster performance to the load factor and wall friction. The nonuniform distribution of the current density in the Hartmann layers of the insulating sidewalls causes the flattening of the velocity profiles on the sidewalls relative to the velocity profiles over the electrode walls. These nonuniformities in the flowfield give rise to nonuniform distribution of the skin friction along the walls of the thrusters, where higher values are predicted over the sidewalls relative to those over the electrode walls. Although the discrepancies of the velocity profiles between the different walls of the MHD thruster are not significant, careful considerations should be given to the calculation of the frictional losses because of their adverse effect on the electrical efficiency of the thruster. C1 OFF NAVAL RES,ARLINGTON,VA 22217. RP DOSS, E (reprint author), ARGONNE NATL LAB,DIV ENGN PHYS,ARGONNE,IL 60439, USA. NR 12 TC 3 Z9 3 U1 0 U2 0 PU AMER INST AERONAUT ASTRONAUT PI RESTON PA 1801 ALEXANDER BELL DRIVE, STE 500, RESTON, VA 22091 SN 0748-4658 J9 J PROPUL POWER JI J. Propul. Power PD JUL-AUG PY 1991 VL 7 IS 4 BP 635 EP 641 DI 10.2514/3.23372 PG 7 WC Engineering, Aerospace SC Engineering GA FY513 UT WOS:A1991FY51300024 ER PT J AU ABBOTT, JR TETLOW, N GRAHAM, AL ALTOBELLI, SA FUKUSHIMA, E MONDY, LA STEPHENS, TS AF ABBOTT, JR TETLOW, N GRAHAM, AL ALTOBELLI, SA FUKUSHIMA, E MONDY, LA STEPHENS, TS TI EXPERIMENTAL-OBSERVATIONS OF PARTICLE MIGRATION IN CONCENTRATED SUSPENSIONS - COUETTE-FLOW SO JOURNAL OF RHEOLOGY LA English DT Article ID SPHERES AB Nuclear magnetic resonance (NMR) imaging was used to observe the evolution of radial concentration and velocity profiles of initially well-mixed concentrated suspensions of spheres in viscous Newtonian liquids undergoing flow between rotating concentric cylinders (wide-gap, annular Couette flow). In Couette flow, particles migrate from the high shear-rate region near the inner rotating cylinder to the low shear-rate region at the outer wall. The particle concentration near the outer wall approaches maximum packing for randomly distributed spheres at steady state, and velocity profiles reveal that the suspension is almost stagnant in these regions. For unimodal suspensions of spheres, the shear-induced migration of large particles results in concentric two-dimensional, circular sheets of particles arranged in hexgonal close-packed arrangements extending inward from the outer wall. This paper examines the functional dependence of particle migration in concentrated suspensions undergoing shear flow in a wide-gap Couette. The primary experimental parameters were strain, shear rate, viscosity of the suspending liquid, particle diameter, and degree of polydispersivity of the particle phase. The particle migration is irreversible, even under creeping flow conditions, and is a function of total strain. Particle migration rate increases with the mean particle diameter raised to 2.7 +/- 0.3 for sieved samples and 2.5 +/- 0.3 for unsieved samples. The particle migration does not depend on the strain rate nor on the suspending liquid viscosity. The migration rate was found to depend only weakly on the polydispersivity of the particulate phase. C1 LOVELACE FDN MED EDUC & RES,ALBUQUERQUE,NM 87108. SANDIA NATL LABS,ALBUQUERQUE,NM 87185. USN,CTR WEAP,CHINA LAKE,CA 93555. RP ABBOTT, JR (reprint author), UNIV CALIF LOS ALAMOS SCI LAB,LOS ALAMOS,NM 87545, USA. RI Stephens, Thomas/D-9512-2012 NR 16 TC 202 Z9 204 U1 1 U2 19 PU AMER INST PHYSICS PI WOODBURY PA CIRCULATION FULFILLMENT DIV, 500 SUNNYSIDE BLVD, WOODBURY, NY 11797-2999 SN 0148-6055 J9 J RHEOL JI J. Rheol. PD JUL PY 1991 VL 35 IS 5 BP 773 EP 795 DI 10.1122/1.550157 PG 23 WC Mechanics SC Mechanics GA FU918 UT WOS:A1991FU91800003 ER PT J AU MONDY, LA INGBER, MS DINGMAN, SE AF MONDY, LA INGBER, MS DINGMAN, SE TI BOUNDARY ELEMENT METHOD SIMULATIONS OF A BALL FALLING THROUGH QUIESCENT SUSPENSIONS SO JOURNAL OF RHEOLOGY LA English DT Article ID STOKES-FLOW; HYDRODYNAMIC INTERACTIONS; CONCENTRATED SUSPENSIONS; MULTIPARTICLE SYSTEMS; PARTICLE INTERACTIONS; DYNAMIC SIMULATION; NUMERICAL-METHOD; RIGID PARTICLES; ARBITRARY SHAPE; SPHERES AB Falling ball rheometry of suspensions of spheres and rods is simulated with a boundary element method. Fully three-dimensional simulations are performed to obtain static, configuration-specific solutions of the particle motions as well as to track the particles in time. The relative viscosities of suspensions of spheres (both unimodal and bimodal in size distribution) with solid volume fractions up to 0.05 are obtained. The effect of the spheres on the pressure drop from the top to the bottom of the cylinder is also investigated. Up to 40 interacting particles are modeled. Suspensions of rods of aspect ratio 5 and 10 (volume fraction of solids equal to 0.01) are also modeled. Results agree with available laboratory measurements. Ensemble averages of configuration-specific solutions give good approximations of the relative viscosity of suspensions, even though flow-induced structure is not accounted for. Each configuration-specific solution requires orders of magnitude less computation time than the dynamic analyses. Further computation time can be saved without loss of accuracy by modeling only those particles within roughly 10 ball radii (about one cylinder radius) of the falling ball. C1 UNIV NEW MEXICO,DEPT CHEM ENGN,ALBUQUERQUE,NM 87131. RP MONDY, LA (reprint author), SANDIA NATL LABS,ALBUQUERQUE,NM 87185, USA. NR 40 TC 10 Z9 10 U1 1 U2 2 PU AMER INST PHYSICS PI WOODBURY PA CIRCULATION FULFILLMENT DIV, 500 SUNNYSIDE BLVD, WOODBURY, NY 11797-2999 SN 0148-6055 J9 J RHEOL JI J. Rheol. PD JUL PY 1991 VL 35 IS 5 BP 825 EP 848 DI 10.1122/1.550159 PG 24 WC Mechanics SC Mechanics GA FU918 UT WOS:A1991FU91800005 ER PT J AU MACK, GH COLE, DR GIORDANO, TH SCHAAL, WC BARCELOS, JH AF MACK, GH COLE, DR GIORDANO, TH SCHAAL, WC BARCELOS, JH TI PALEOCLIMATIC CONTROLS ON STABLE OXYGEN AND CARBON ISOTOPES IN CALICHE OF THE ABO FORMATION (PERMIAN), SOUTH-CENTRAL NEW-MEXICO, USA SO JOURNAL OF SEDIMENTARY PETROLOGY LA English DT Article ID GROUND WATERS; UNITED-STATES; SOILS; CALCRETE; PLEISTOCENE; GEOCHEMISTRY; PALAEOSOLS; RHIZOLITHS; AUSTRALIA; PALEOSOLS AB The stable oxygen and carbon isotopic composition of caliche in fluvial and supratidal rocks of the Abo Formation (Permian), south-central New Mexico, is controlled by palecoclimate and depositional environment. Fluvial caliche consists of low-Mg calcite nodules and vertically oriented tubules that display stage II texture. Micrite matrix support, brecciation, ooids/pisoliths, aveolar-septal texture, and peloids are common in the fluvial caliche and, along with red color and slickensides in the host shale, indicate pedogenesis in a well-oxidized vadose zone. In contrast, periodic waterlogging of the supratidal paleosols, probably due to high water table, is indicated by drab colors, carbonaceous flecks, horizontal rhizoliths, and the paucity of vadose textures in the stage II caliche nodules. Stable oxygen isotopes are similar in the fluvial and supratidal caliches and range from 21.6 to 30.5 parts per thousand (SMOW). The data exhibit a crude bimodality and delta-O-18 enrichment with a decrease in age (higher in the section). Consideration of these data in the context of delta-temperature relations suggests that 1) surface waters responsible for caliche formation increased in delta-O-18 (from roughly -8 to + 1 parts per thousand) over the 18 m.y. time interval that separated the lowest stratigraphic nodule horizon from the highest, 2) the increasing delta-O-18 values also reflect a warming trend (approximately 15-degrees to nearly 30-degrees-C) in the mean monthly temperature over this same time period, with perhaps an associated increase in Permian ocean temperatures, and 3) the significant variation in delta-O-18 from oldest to youngest caliche was probably enhanced by the "amount" effect, such that as the temperature increased, the amount of precipitation decreased, resulting in high delta-O-18 values. Caliches in the Abo are enriched in heavy carbon (-7.2 to -1.5 part per thousand PDB) compared to that of soil carbonate derived exclusively from C3 plants (-12 part per thousand PDB), and the supratidal caliches contain somewhat heavier carbon compared to the fluvial caliche. The delta-C-13 values for both environments increase with a decrease in caliche age. These results indicate that as the temperature increased and rainfall decreased with time, the level of C3 plant productivity apparently declined, allowing a greater influx of atmospheric CO2 into the soil. This can only occur when soil respiration rates are quite low or at very shallow depths (less than 10 cm), or both. Atmospheric CO2 seems to have invaded the supratidal soils to a somewhat greater extent than the fluvial soils. C1 OAK RIDGE NATL LAB,DIV CHEM,OAK RIDGE,TN 37831. UNIV ESTADUAL PAULISTA JULIO MESQUITA FILHO,INST GEOSCI & CIENCIAS EXATAS,RIO CLARO,SP,BRAZIL. RP MACK, GH (reprint author), NEW MEXICO STATE UNIV,DEPT EARTH SCI,LAS CRUCES,NM 88003, USA. NR 73 TC 43 Z9 46 U1 0 U2 9 PU SEPM-SOC SEDIMENTARY GEOLOGY PI TULSA PA 1731 E 71ST STREET, TULSA, OK 74136-5108 SN 0022-4472 J9 J SEDIMENT PETROL PD JUL PY 1991 VL 61 IS 4 BP 458 EP 472 PG 15 WC Geology SC Geology GA FV040 UT WOS:A1991FV04000002 ER PT J AU HINATSU, Y EDELSTEIN, N AF HINATSU, Y EDELSTEIN, N TI ANALYSIS OF THE OPTICAL-SPECTRA AND MAGNETIC-SUSCEPTIBILITIES OF LI7UO6, BA3NPO6, AND LI5PUO6 SO JOURNAL OF SOLID STATE CHEMISTRY LA English DT Article ID SPIN C1 UNIV CALIF BERKELEY LAWRENCE BERKELEY LAB,DIV MAT & CHEM SCI,BERKELEY,CA 94720. RP HINATSU, Y (reprint author), JAPAN ATOM ENERGY RES INST,DEPT CHEM,TOKAI,IBARAKI 31911,JAPAN. NR 20 TC 4 Z9 4 U1 0 U2 0 PU ACADEMIC PRESS INC JNL-COMP SUBSCRIPTIONS PI SAN DIEGO PA 525 B ST, STE 1900, SAN DIEGO, CA 92101-4495 SN 0022-4596 J9 J SOLID STATE CHEM JI J. Solid State Chem. PD JUL PY 1991 VL 93 IS 1 BP 173 EP 182 DI 10.1016/0022-4596(91)90286-Q PG 10 WC Chemistry, Inorganic & Nuclear; Chemistry, Physical SC Chemistry GA FV973 UT WOS:A1991FV97300020 ER PT J AU PARISE, JB MCCARRON, EM VONDREELE, R AF PARISE, JB MCCARRON, EM VONDREELE, R TI BETA-MOO3 PRODUCED FROM A NOVEL FREEZE-DRYING ROUTE SO JOURNAL OF SOLID STATE CHEMISTRY LA English DT Article ID MOO3; WO3 C1 SUNY STONY BROOK,DEPT EARTH & SPACE SCI,STONY BROOK,NY 11794. DUPONT CO,DEPT CENT RES & DEV,EXPTL STN,WILMINGTON,DE 19880. UNIV CALIF LOS ALAMOS SCI LAB,MANUAL LUJAN JR NEUTRON SCATTERING CTR,LOS ALAMOS,NM 87545. RP PARISE, JB (reprint author), SUNY STONY BROOK,INST MINERAL PHYS,STONY BROOK,NY 11794, USA. NR 12 TC 58 Z9 58 U1 1 U2 6 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 JUL PY 1991 VL 93 IS 1 BP 193 EP 201 DI 10.1016/0022-4596(91)90288-S PG 9 WC Chemistry, Inorganic & Nuclear; Chemistry, Physical SC Chemistry GA FV973 UT WOS:A1991FV97300022 ER PT J AU BENDER, C COOPER, F SIMMONS, LM ROY, P KILCUP, G AF BENDER, C COOPER, F SIMMONS, LM ROY, P KILCUP, G TI NOVEL PERTURBATION EXPANSION FOR THE LANGEVIN EQUATION SO JOURNAL OF STATISTICAL PHYSICS LA English DT Article DE LANGEVIN EQUATION; DELTA EXPANSION; NONLINEAR; PERTURBATION EXPANSION; SCALING RELATIONS ID CLASSICAL STATISTICAL DYNAMICS; STRONG-COUPLING EXPANSION; FIELD-THEORY; DIMENSIONS; LATTICE AB We discuss the randomly driven system dx/dt = -W(x) + f(t), where f(t) is a Gaussian random function or stirring force with = 2-delta-(t-t'), and W(x) is of the form gx1 + 2-delta. The parameter delta is a measure of the nonlinearity of the equation. We show how to obtain the correlation functions f as a power series in delta. We obtain three terms in the delta expansion and show how to use Pade approximants to analytically continue the answer in the variable delta. By using scaling relations, we show how to get a uniform approximation to the equal-time correlation functions valid for all g and delta. C1 UNIV CALIF LOS ALAMOS SCI LAB,DIV THEORET,LOS ALAMOS,NM 87545. SANTA FE INST,SANTA FE,NM 87501. INDIAN STAT INST,ELECTR UNIT,CALCUTTA 700035,W BENGAL,INDIA. OHIO STATE UNIV,DEPT PHYS,COLUMBUS,OH 43210. RP BENDER, C (reprint author), WASHINGTON UNIV,DEPT PHYS,ST LOUIS,MO 63101, USA. NR 11 TC 8 Z9 8 U1 0 U2 1 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 JUL PY 1991 VL 64 IS 1-2 BP 395 EP 428 DI 10.1007/BF01057884 PG 34 WC Physics, Mathematical SC Physics GA FY144 UT WOS:A1991FY14400019 ER PT J AU GARBEY, M KAPER, HG LEAF, GK MATKOWSKY, BJ AF GARBEY, M KAPER, HG LEAF, GK MATKOWSKY, BJ TI USING MAPLE FOR THE ANALYSIS OF BIFURCATION PHENOMENA IN CONDENSED-PHASE SURFACE COMBUSTION SO JOURNAL OF SYMBOLIC COMPUTATION LA English DT Article ID FLAME PROPAGATION C1 UNIV LYON 1,ANALYSE NUMERIQUE LAB,F-69622 VILLEURBANNE,FRANCE. NORTHWESTERN UNIV,DEPT ENGN SCI & APPL MATH,EVANSTON,IL 60208. RP GARBEY, M (reprint author), ARGONNE NATL LAB,DIV MATH & COMP SCI,ARGONNE,IL 60439, USA. RI Matkowsky, Bernard/B-7371-2009 NR 14 TC 5 Z9 5 U1 0 U2 1 PU ACADEMIC PRESS LTD PI LONDON PA 24-28 OVAL RD, LONDON, ENGLAND NW1 7DX SN 0747-7171 J9 J SYMB COMPUT JI J. Symb. Comput. PD JUL PY 1991 VL 12 IS 1 BP 89 EP 113 DI 10.1016/S0747-7171(08)80141-1 PG 25 WC Computer Science, Theory & Methods; Mathematics, Applied SC Computer Science; Mathematics GA GA163 UT WOS:A1991GA16300004 ER PT J AU SHERA, CA ZWEIG, G AF SHERA, CA ZWEIG, G TI PHENOMENOLOGICAL CHARACTERIZATION OF EARDRUM TRANSDUCTION SO JOURNAL OF THE ACOUSTICAL SOCIETY OF AMERICA LA English DT Article ID TYMPANIC-MEMBRANE VIBRATIONS; TIME-AVERAGED HOLOGRAPHY; MIDDLE-EAR; MODEL; CAT; TRANSMISSION AB A phenomenological description of the transduction effected by the eardrum is presented. That description is provided by a transfer matrix, whose elements define those measurements sufficient to characterize eardrum transduction. Causality provides constraints on the matrix elements. In addition, measurements of the matrix elements can determine whether they satisfy constraints imposed by minimum-phase behavior and the principle of reciprocity. Those constraints may be used either to reduce the number of measurements necessary to characterize the eardrum or to check the consistency of measurements that overdetermine the system. Within its region of validity, the transfer matrix of the eardrum provides a common ground for the comparison between theory and experiment. As an example, a simple model for the transduction characteristics of the eardrum, defined completely in terms of measurable quantities, is presented. C1 CALTECH,DEPT PHYS,PASADENA,CA 91125. RP SHERA, CA (reprint author), UNIV CALIF LOS ALAMOS SCI LAB,DIV THEORET,LOS ALAMOS,NM 87545, USA. NR 50 TC 21 Z9 21 U1 0 U2 0 PU AMER INST PHYSICS PI WOODBURY PA CIRCULATION FULFILLMENT DIV, 500 SUNNYSIDE BLVD, WOODBURY, NY 11797-2999 SN 0001-4966 J9 J ACOUST SOC AM JI J. Acoust. Soc. Am. PD JUL PY 1991 VL 90 IS 1 BP 253 EP 262 DI 10.1121/1.401295 PG 10 WC Acoustics; Audiology & Speech-Language Pathology SC Acoustics; Audiology & Speech-Language Pathology GA FV280 UT WOS:A1991FV28000031 PM 1880296 ER PT J AU MOORE, WH AF MOORE, WH TI BETWEEN DAYLIGHT AND DARKNESS SO JOURNAL OF THE AIR & WASTE MANAGEMENT ASSOCIATION LA English DT Article RP MOORE, WH (reprint author), US DOE,WASHINGTON,DC 20545, USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU AIR & WASTE MANAGEMENT ASSOC PI PITTSBURGH PA PO BOX 2861, PITTSBURGH, PA 15230 SN 1047-3289 J9 J AIR WASTE MANAGE JI J. Air Waste Manage. Assoc. PD JUL PY 1991 VL 41 IS 7 BP 904 EP 905 PG 2 WC Engineering, Environmental; Environmental Sciences; Meteorology & Atmospheric Sciences SC Engineering; Environmental Sciences & Ecology; Meteorology & Atmospheric Sciences GA FY406 UT WOS:A1991FY40600003 ER PT J AU HSUEH, CH AF HSUEH, CH TI SOME CONSIDERATIONS OF DETERMINATION OF RESIDUAL-STRESSES AND YOUNGS MODULI IN CERAMIC COATINGS SO JOURNAL OF THE AMERICAN CERAMIC SOCIETY LA English DT Article DE COATINGS; SUBSTRATES; STRESS; YOUNGS MODULUS; BENDING ID FILMS AB Residual stresses that develop during cooling of a ceramic coating/substrate strip are considered. Bending occurs because of an asymmetric stress distribution in the strip. In the presence of residual stresses, strains induced on the surfaces of the coating and the substrate are analyzed when (1) the coating-substrate interface exhibits a transition from a bonded to a debonded state, and (2) a bending moment is applied to straighten the strip. The result shows that both the residual stress and Young's modulus in the ceramic coating can be determined from the surface strains due to either interfacial debonding or strip straightening, Young's modulus of the substrate, and the thicknesses of the coating and the substrate. RP HSUEH, CH (reprint author), OAK RIDGE NATL LAB,DIV KREBSFORSCH,OAK RIDGE,TN 37831, USA. RI Hsueh, Chun-Hway/G-1345-2011 NR 8 TC 19 Z9 19 U1 1 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 JUL PY 1991 VL 74 IS 7 BP 1646 EP 1649 DI 10.1111/j.1151-2916.1991.tb07153.x PG 4 WC Materials Science, Ceramics SC Materials Science GA FX399 UT WOS:A1991FX39900022 ER PT J AU JANNEY, MA KIMREY, HD SCHMIDT, MA KIGGANS, JO AF JANNEY, MA KIMREY, HD SCHMIDT, MA KIGGANS, JO TI GRAIN-GROWTH IN MICROWAVE-ANNEALED ALUMINA SO JOURNAL OF THE AMERICAN CERAMIC SOCIETY LA English DT Article DE GRAIN GROWTH; MICROWAVES; ALUMINA; ANNEALING; ACTIVATION ENERGY ID KINETICS; AL2O3 AB Normal grain growth in dense, fine-grained, aluminum oxide-0.1 wt% MgO was studied under both conventional furnance and 28-GHz microwave furnace annealing conditions. The microstructural changes that occurred were the same for both sets of samples; soap bubble microstructures were observed and the aspect ratios and shape factors did not change during the anneals. The kinetics of grain growth were greatly increased by the 28-GHz microwave anneals; e.g., the grain growth rate at 1500-degrees-C in the microwave furnace was the same as the rate at 1700-degrees-C in the conventional furnance. Also, the activation energy for grain growth was reduced by the microwave anneal from 590 kJ/mol (conventional) to 480 kJ/mol (microwave). Finally, these results demonstrate that a "microwave effect" can exist in a dense ceramic body and that no free pore-solid interfaces are necessary. RP JANNEY, MA (reprint author), OAK RIDGE NATL LAB,OAK RIDGE,TN 37831, USA. RI kiggans, james/E-1588-2017 OI kiggans, james/0000-0001-5056-665X NR 20 TC 84 Z9 90 U1 3 U2 12 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 JUL PY 1991 VL 74 IS 7 BP 1675 EP 1681 DI 10.1111/j.1151-2916.1991.tb07159.x PG 7 WC Materials Science, Ceramics SC Materials Science GA FX399 UT WOS:A1991FX39900028 ER PT J AU MAYA, L COLE, DR HAGAMAN, EW AF MAYA, L COLE, DR HAGAMAN, EW TI CARBON NITROGEN PYROLYZATES - ATTEMPTED PREPARATION OF CARBON NITRIDE SO JOURNAL OF THE AMERICAN CERAMIC SOCIETY LA English DT Note DE PRESSURE; CARBON; NITRIDES; SYNTHESIS; PYROLYSIS AB Precursors for the preparation of carbon nitride were selected from a number of relatively high nitrogen content organic materials. The precursors were pyrolyzed in a closed system at 700-degrees-C under 225 MPa. The resulting residues showed little nitrogen loss, but were amorphous with relatively low densities. Raman spectroscopy and C-13 NMR indicate the presence of trigonal carbon. RP MAYA, L (reprint author), OAK RIDGE NATL LAB,DIV CHEM,OAK RIDGE,TN 37831, USA. NR 11 TC 191 Z9 191 U1 1 U2 12 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 JUL PY 1991 VL 74 IS 7 BP 1686 EP 1688 DI 10.1111/j.1151-2916.1991.tb07161.x PG 3 WC Materials Science, Ceramics SC Materials Science GA FX399 UT WOS:A1991FX39900030 ER PT J AU CHAN, SK FANG, Y GRIMSDITCH, M LI, Z NEVITT, MV ROBERTSON, WM ZOUBOULIS, ES AF CHAN, SK FANG, Y GRIMSDITCH, M LI, Z NEVITT, MV ROBERTSON, WM ZOUBOULIS, ES TI TEMPERATURE-DEPENDENCE OF THE ELASTIC-MODULI OF MONOCLINIC ZIRCONIA SO JOURNAL OF THE AMERICAN CERAMIC SOCIETY LA English DT Note DE ELASTIC CONSTANTS; ZIRCONIA; SINGLE CRYSTAL; TEMPERATURE DEPENDENCE; SOUND AB We have used Brillouin scattering to measure the temperature dependence of the sound velocities of the longitudinal and transverse vibrational modes in various directions in small single crystals of monoclinic ZrO2. Using these velocities and the Christoffel equation, we have calculated the 13 elastic stiffness moduli between room temperature and the monoclinic-tetragonal transformation temperature. RP CHAN, SK (reprint author), ARGONNE NATL LAB,DIV MAT SCI,ARGONNE,IL 60439, USA. NR 7 TC 69 Z9 69 U1 1 U2 17 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 JUL PY 1991 VL 74 IS 7 BP 1742 EP 1744 DI 10.1111/j.1151-2916.1991.tb07177.x PG 3 WC Materials Science, Ceramics SC Materials Science GA FX399 UT WOS:A1991FX39900046 ER PT J AU GIRILL, TR GRIFFIN, T JONES, RB AF GIRILL, TR GRIFFIN, T JONES, RB TI EXTENDED SUBJECT ACCESS TO HYPERTEXT ONLINE DOCUMENTATION .1.2. THE SEARCH-SUPPORT AND MAINTENANCE PROBLEMS SO JOURNAL OF THE AMERICAN SOCIETY FOR INFORMATION SCIENCE LA English DT Article ID INFORMATION; SYSTEMS; RETRIEVAL; ISSUES AB The DFT (DOCUMENT, FIND, THESEUS) online documentation system resembles other hypertext software in managing a full-text database with reference links (pointers) between passages (nodes). But DFT's prime role as an end-user reference service at a computer center where text updates are frequent required extra access methods often neglected in hypertext systems. To solve the problem of rapid, high-recall search for specific answer passages we combined syntactical interface features (substring and fuzzy matching of search terms) with a semantic expansion of the system's entry vocabulary. Extensive aliasing increased the number of descriptions under which any passage could be found. Conversion of the NBS GAMS classification scheme for mathematical software into descriptors allowed us to impose a virtual organization on our subroutine documentation that supports easy, task-oriented retrieval without tedious path walking. To solve the problem of reliable database maintenance amid frequent passage revisions we developed software tools for flexible input of text and entry-term changes, as well as for thorough and versatile status reporting. These, together with special features for testing and privately simulating changes and for coordinating the sequence of text and entry-term updates for maximum efficiency, yielded a robust and practical answer-delivery system. RP GIRILL, TR (reprint author), UNIV CALIF LAWRENCE LIVERMORE NATL LAB,NATL ENERGY RES SUPERCOMP CTR,LIVERMORE,CA 94550, USA. NR 33 TC 3 Z9 3 U1 0 U2 0 PU JOHN WILEY & SONS INC PI NEW YORK PA 605 THIRD AVE, NEW YORK, NY 10158-0012 SN 0002-8231 J9 J AM SOC INFORM SCI JI J. Am. Soc. Inf. Sci. PD JUL PY 1991 VL 42 IS 6 BP 414 EP 426 DI 10.1002/(SICI)1097-4571(199107)42:6<414::AID-ASI4>3.0.CO;2-V PG 13 WC Computer Science, Information Systems; Information Science & Library Science SC Computer Science; Information Science & Library Science GA FU468 UT WOS:A1991FU46800004 ER PT J AU GIRILL, TR AF GIRILL, TR TI EXTENDED SUBJECT ACCESS TO HYPERTEXT ONLINE DOCUMENTATION .3. THE DOCUMENT-BOUNDARIES PROBLEM SO JOURNAL OF THE AMERICAN SOCIETY FOR INFORMATION SCIENCE LA English DT Article ID ISSUES; TEXT AB Because the DFT (DOCUMENT, FIND, THESEUS) online documentation system supports the hybrid goals of computer-managed on-demand printing of software manuals as well as the interactive retrieval of reference passages, its hypertext database is partitioned by stable document boundaries. These document boundaries solve some organizational problems to which newer hypertext systems are prone: they help disambiguate multiple hits and they promote unified editing and monitoring of passages that belong together intellectually. They make online cross-references harder to use efficiently, however, and they create "local" contexts for keyword choices that introduce apparent inconsistencies from the perspective of global searching. Supporting document-based along with document-independent searches also runs a risk of invoking conflicting mental models in users. Finally, the virtual database structures of which hypertext systems boast are constrained by the size of the system's text nodes. With node sizes chosen large enough to preserve the logical structure of within-document passages, however, this constraint actually improves a hypertext's explanatory value. RP GIRILL, TR (reprint author), UNIV CALIF LAWRENCE LIVERMORE NATL LAB,NATL ENERGY RES SUPERCOMP CTR,LIVERMORE,CA 94550, USA. NR 29 TC 3 Z9 3 U1 0 U2 1 PU JOHN WILEY & SONS INC PI NEW YORK PA 605 THIRD AVE, NEW YORK, NY 10158-0012 SN 0002-8231 J9 J AM SOC INFORM SCI JI J. Am. Soc. Inf. Sci. PD JUL PY 1991 VL 42 IS 6 BP 427 EP 437 DI 10.1002/(SICI)1097-4571(199107)42:6<427::AID-ASI5>3.0.CO;2-I PG 11 WC Computer Science, Information Systems; Information Science & Library Science SC Computer Science; Information Science & Library Science GA FU468 UT WOS:A1991FU46800005 ER PT J AU MUNRO, NB SHUGART, LR WATSON, AP HALBROOK, RS AF MUNRO, NB SHUGART, LR WATSON, AP HALBROOK, RS TI CHOLINESTERASE ACTIVITY IN DOMESTIC-ANIMALS AS A POTENTIAL BIOMONITOR FOR NERVE AGENT AND OTHER ORGANOPHOSPHATE EXPOSURE SO JOURNAL OF THE AMERICAN VETERINARY MEDICAL ASSOCIATION LA English DT Review ID WHOLE-BLOOD; ORGANO-PHOSPHORUS; CEREBROSPINAL-FLUID; PHYSICAL EXERCISE; YOUNG CHICKENS; PHOSPHATE; TOXICITY; PLASMA; INHIBITION; GOATS C1 OAK RIDGE NATL LAB,DIV ENVIRONM SCI,OAK RIDGE,TN 37831. RP MUNRO, NB (reprint author), OAK RIDGE NATL LAB,DIV HLTH & SAFETY RES,POB 2008,OAK RIDGE,TN 37831, USA. NR 69 TC 29 Z9 29 U1 1 U2 1 PU AMER VETERINARY MEDICAL ASSOC PI SCHAUMBURG PA 1931 N MEACHAM RD SUITE 100, SCHAUMBURG, IL 60173-4360 SN 0003-1488 J9 J AM VET MED ASSOC JI J. Am. Vet. Med. Assoc. PD JUL 1 PY 1991 VL 199 IS 1 BP 103 EP 115 PG 13 WC Veterinary Sciences SC Veterinary Sciences GA FU287 UT WOS:A1991FU28700029 PM 1885319 ER PT J AU BRAMMER, L CHARNOCK, JM GOGGIN, PL GOODFELLOW, RJ ORPEN, AG KOETZLE, TF AF BRAMMER, L CHARNOCK, JM GOGGIN, PL GOODFELLOW, RJ ORPEN, AG KOETZLE, TF TI THE ROLE OF TRANSITION-METAL ATOMS AS HYDROGEN-BOND ACCEPTORS - A NEUTRON-DIFFRACTION STUDY OF [NPRN4]2[PTCL4].CIS-[PTCL2(NH2ME)2] AT 20-K SO JOURNAL OF THE CHEMICAL SOCIETY-DALTON TRANSACTIONS LA English DT Article ID MOLECULAR-STRUCTURES; PLATINUM(II) COMPLEXES; SCHIFF-BASE; N-H; O-H; CRYSTAL; PALLADIUM(II); LIGAND; METHYLAMINE; CISPLATIN AB Single-crystal neutron diffraction has allowed accurate characterisation of N-H...Pt and N-H...Cl interactions linking the two square-planar platinum(II) units which comprise the dianion of [NPr(n)4]2[PtCl4].cis-[PtCl2(NH2Me)2] 1: Pt...H 2.262(11) angstrom, N-H...Pt 167.1(9)-degrees; Cl...H 2.318(12) angstrom, N-H...Cl 151.0(12)-degrees. An extensive network of C-H...Cl hydrogen bonding between the cation and anion species is also revealed, and provides valuable information on what is one of the least well characterised types of hydrogen bond. A weak C-H...Pt interaction between one cation unit and the anion is also observed. In the light of this and particularly the stronger intra-anion N-H...Pt interaction, a new type of three-centre four-electron hydrogen bridge, involving a transition-metal atom, is proposed. Further supporting evidence is drawn from a re-evaluation of spectroscopic data for similar interactions previously reported. This type of interaction is contrasted with the more well known three-centre two-electron M-H half-arrow-pointing-right M, C-H half-arrow-pointing-right M, Si-H half-arrow-pointing-right M and B-H half-arrow-pointing-right M interactions and compared with conventional four-electron hydrogen bonds. Compound 1 is triclinic, space group P1BAR (no.2), Z = 2, with a = 10.680(4), b = 11.926(2), c = 15.350(15) angstrom, alpha = 93.88(4), beta = 100.57(5) and gamma 96.58(4)-degrees at 20 K. Final R(F2) = 0.124, S = 1.136 for 5244 F2 values (F0(2) > 0.0). C1 UNIV BRISTOL, DEPT INORGAN CHEM, BRISTOL BS8 1TS, AVON, ENGLAND. BROOKHAVEN NATL LAB, DEPT CHEM, UPTON, NY 11973 USA. NR 67 TC 158 Z9 158 U1 0 U2 5 PU ROYAL SOC CHEMISTRY PI CAMBRIDGE PA THOMAS GRAHAM HOUSE, SCIENCE PARK, MILTON RD, CAMBRIDGE CB4 0WF, CAMBS, ENGLAND SN 1472-7773 J9 J CHEM SOC DALTON JI J. Chem. Soc.-Dalton Trans. PD JUL PY 1991 IS 7 BP 1789 EP 1798 DI 10.1039/dt9910001789 PG 10 WC Chemistry, Inorganic & Nuclear SC Chemistry GA FW478 UT WOS:A1991FW47800023 ER PT J AU LIU, ML VISCO, SJ DEJONGHE, LC AF LIU, ML VISCO, SJ DEJONGHE, LC TI NOVEL SOLID REDOX POLYMERIZATION ELECTRODES - ALL-SOLID-STATE, THIN-FILM, RECHARGEABLE LITHIUM BATTERIES SO JOURNAL OF THE ELECTROCHEMICAL SOCIETY LA English DT Article; Proceedings Paper CT MEETING OF THE ELECTROCHEMICAL SOC CY OCT 15-20, 1989 CL HOLLYWOOD, FL SP ELECTROCHEM SOC AB Lithium batteries using solid redox polymerization electrodes (SRPEs) maintain the inherent advantages of all-solid-state, thin-film systems while overcoming some of the limitations of using intercalation compounds as positive electrode (i.e., insufficient rate capability and capacity utilization). Laboratory Li/PEO/SRPE cells have demonstrated higher power capability, energy density, and capacity utilization than analogous Li/PEO/TiS2 cells. One of the Li/PEO/SRPE cells has achieved 350 cycles from 50 to 93-degrees-C with a sustained energy density of 160 Wh/kg (190 Wh/l), power density of 120 W/kg (140 W/l), and 40-75% capacity utilization of the polymerization electrode. At 100-degrees-C, power densities of over 1800 W/kg (2200 W/l) at energy densities of 140 Wh/kg (170 Wh/l) have been achieved with up to 96% utilization of cathode capacity. At ambient temperatures (35-degrees-C), the cells can be discharged at a current density of 250-mu-A/cm2, achieving a film capacity of 0.5 C/cm2. C1 UNIV CALIF BERKELEY,DEPT MAT SCI & MINERAL ENGN,BERKELEY,CA 94720. UNIV CALIF BERKELEY LAWRENCE BERKELEY LAB,DIV MAT & CHEM SCI,BERKELEY,CA 94720. RI Liu, Meilin/E-5782-2010 OI Liu, Meilin/0000-0002-6188-2372 NR 10 TC 129 Z9 141 U1 2 U2 33 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 JUL PY 1991 VL 138 IS 7 BP 1891 EP 1895 DI 10.1149/1.2085895 PG 5 WC Electrochemistry; Materials Science, Coatings & Films SC Electrochemistry; Materials Science GA FW341 UT WOS:A1991FW34100005 ER PT J AU LIU, ML VISCO, SJ DEJONGHE, LC AF LIU, ML VISCO, SJ DEJONGHE, LC TI NOVEL SOLID REDOX POLYMERIZATION ELECTRODES - ELECTROCHEMICAL PROPERTIES SO JOURNAL OF THE ELECTROCHEMICAL SOCIETY LA English DT Article; Proceedings Paper CT MEETING OF THE ELECTROCHEMICAL SOC CY OCT 15-20, 1989 CL HOLLYWOOD, FL SP ELECTROCHEM SOC ID BATTERIES; STORAGE AB The generic redox reaction of a class of linear sulfur-containing redox polymerication electrodes can be described as (-SRS-)n + n (2e-) reversible n (-SRS-) that is, the polymer electrode can be progressively depolymerized, leading ultimately to monomeric anions, as the sulfur-sulfur bridges between the organic R groups are cleaved during discharge and then the monomer anions can be subsequently reoxidized back to the original polymer during charge. This is the first time the process of electrodepolymerization-electropolymerization has been exploited for energy storage, establishing a broad class of chemically flexible, low equivalent weight, and inexpensive electrodes for advanced batteries. Electrochemical investigation of a diverse group of novel solid redox polymerization electrodes indicates that these materials are excellent candidates for all-solid-state, thin-film, energy-storage systems. Some of the advantages offered by the batteries based on these materials include high energy density and rate capability, extensive utilization of positive electrode capacity, ease of fabrication, low cost, and superior reliability, and safety. In addition, these materials are reversible to lithium and sodium (as well as many alkaline earth and transition metals), allowing for a much greater choice of negative electrode materials, in stark contrast to cells based on analogous intercalation compounds. Further, and in particular, a great advantage of redox polymerization electrodes is the ability to alter the physical, chemical, and electrochemical properties of these materials in a very predictable manner through manipulation of various functional groups, electron-withdrawing heteroatoms, and the molecular architecture. C1 UNIV CALIF BERKELEY,DEPT MAT SCI & MINERAL ENGN,BERKELEY,CA 94720. UNIV CALIF BERKELEY LAWRENCE BERKELEY LAB,DIV MAT & CHEM SCI,BERKELEY,CA 94720. RI Liu, Meilin/E-5782-2010 OI Liu, Meilin/0000-0002-6188-2372 NR 15 TC 81 Z9 93 U1 3 U2 25 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 JUL PY 1991 VL 138 IS 7 BP 1896 EP 1901 DI 10.1149/1.2085896 PG 6 WC Electrochemistry; Materials Science, Coatings & Films SC Electrochemistry; Materials Science GA FW341 UT WOS:A1991FW34100006 ER PT J AU JORDAN, KG TOBIAS, CW AF JORDAN, KG TOBIAS, CW TI SIMULATION OF THE ROLE OF CONVECTION IN ELECTRODEPOSITION INTO MICROSCOPIC TRENCHES SO JOURNAL OF THE ELECTROCHEMICAL SOCIETY LA English DT Article ID SMALL CAVITIES; FLUID-FLOW; MASS-TRANSPORT AB The effect on mass transport of Couette and Poiseuille flows passing by a microscopic angular notch is calculated using the finite element method. Recirculation regions are characterized as a function of Reynolds number, notch angle, and depth. The increase in transport rates caused by convective eddies is assessed relative to the pure diffusion case, for boundary layer thicknesses equal to or one ninth as large as the notch depth. Secondary flows are shown to noticeably enhance transport into microscopic trenches at high Peclet numbers, i.e., at very high flow velocities. C1 UNIV CALIF BERKELEY,DEPT CHEM ENGN,BERKELEY,CA 94720. UNIV CALIF BERKELEY LAWRENCE BERKELEY LAB,DIV MAT & CHEM SCI,BERKELEY,CA 94720. NR 19 TC 10 Z9 13 U1 1 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 JUL PY 1991 VL 138 IS 7 BP 1933 EP 1939 DI 10.1149/1.2085903 PG 7 WC Electrochemistry; Materials Science, Coatings & Films SC Electrochemistry; Materials Science GA FW341 UT WOS:A1991FW34100013 ER PT J AU CURTISS, LA HALLEY, JW HAUTMAN, J HUNG, NC NAGY, Z RHEE, YJ YONCO, RM AF CURTISS, LA HALLEY, JW HAUTMAN, J HUNG, NC NAGY, Z RHEE, YJ YONCO, RM TI TEMPERATURE-DEPENDENCE OF THE HETEROGENEOUS FERROUS-FERRIC ELECTRON-TRANSFER REACTION-RATE - COMPARISON OF EXPERIMENT AND THEORY SO JOURNAL OF THE ELECTROCHEMICAL SOCIETY LA English DT Article ID MOLECULAR-DYNAMICS; AQUEOUS-SOLUTION; METAL-IONS; KINETICS; WATER; ABINITIO; RANGE AB We describe experiments on the temperature dependence of the rate of the ferrous-ferric electron transfer reaction at a gold electrode and compare them with a detailed molecular dynamics simulation which is used to predict the rate. We find from the experiments that the temperature dependence of the rate has the Arrhenius form over the temperature range from 25 to 275-degrees-C, and that the transfer coefficient is independent of temperature in this range. The molecular dynamics simulations are used in two ways to extract activation energies and transfer coefficients for comparison with experiment. In one of these methods, we assume parabolic dependence of the energies for the product and reactant in a reaction coordinate which is not specified a priori. In the other method, we use a quantum mechanical calculation extrapolated from the very short molecular dynamics time scale to times characteristic of the electron transfer rate. The assumption of parabolic dependence of the energies gives an estimate for the activation energy which is consistent with experiment. The transfer coefficient calculated using this assumption is also consistent with experiment. The activation energy and the transfer coefficient from the quantum mechanical calculation are both lower than the experimental values. The quantum mechanical method, together with a molecular orbital calculation of the electron transfer matrix element, permits a theoretical estimate of the absolute value of the rate, which is also compared with the experimental result. These results show that the ferrous-ferric reaction, which is a single-step outer-sphere charge-transfer reaction, follows the classical Butler-Volmer equation at temperatures up to 275-degrees-C, and that earlier results on other reactions giving a temperature dependent transfer coefficient are likely to arise from elementary steps other than outer-sphere charge transfer. C1 ARGONNE NATL LAB, DIV CHEM TECHNOL, ARGONNE, IL 60439 USA. UNIV MINNESOTA, SCH PHYS & ASTRON, MINNEAPOLIS, MN 55455 USA. RP ARGONNE NATL LAB, DIV MAT SCI, ARGONNE, IL 60439 USA. NR 45 TC 48 Z9 48 U1 1 U2 12 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 JUL PY 1991 VL 138 IS 7 BP 2032 EP 2041 DI 10.1149/1.2085919 PG 10 WC Electrochemistry; Materials Science, Coatings & Films SC Electrochemistry; Materials Science GA FW341 UT WOS:A1991FW34100030 ER PT J AU AHO, JM BUSH, AO WOLFE, RW AF AHO, JM BUSH, AO WOLFE, RW TI HELMINTH-PARASITES OF BOWFIN (AMIA-CALVA) FROM SOUTH-CAROLINA SO JOURNAL OF THE HELMINTHOLOGICAL SOCIETY OF WASHINGTON LA English DT Article DE BOWFIN; AMIA-CALVA; HELMINTHS; FREQUENCY; INTENSITY; SPECIES RICHNESS; INFRACOMMUNITY COMPOSITION ID INTESTINAL HELMINTHS; PATTERNS; COMMUNITIES; FISH AB Twelve bowfin (Amia calva) collected from 3 backwaters off the Savannah River in South Carolina were examined for helminth parasites. Thirteen species were found: 5 trematodes, 2 cestodes, 5 nematodes, and 1 acanthocephalan. Five species (2 trematodes, 2 cestodes, and 1 acanthocephalan) occur regularly and are considered core species. Species richness and community abundance were high compared to published studies on other species of freshwater fish. Although mean number of species and diversity were comparable to infra-community patterns observed for many aquatic birds, the abundance of helminths was reduced. Host specificity and broad feeding preferences are suggested as important determinants of helminth community structure in bowfin. C1 UNIV GEORGIA,SAVANNAH RIVER ECOL LAB,DRAWER E,AIKEN,SC 29802. BRANDON UNIV,DEPT ZOOL,BRANDON R7A 6A9,MANITOBA,CANADA. NR 32 TC 27 Z9 28 U1 1 U2 6 PU HELMINTHOLOGICAL SOC WASHINGTON PI LAWRENCE PA C/O ALLEN PRESS INC, 1041 NEW HAMPSHIRE ST, LAWRENCE, KS 66044 SN 1049-233X J9 J HELMINTHOL SOC W JI J. Helminthol. Soc. Wash. PD JUL PY 1991 VL 58 IS 2 BP 171 EP 175 PG 5 WC Parasitology; Zoology SC Parasitology; Zoology GA GD363 UT WOS:A1991GD36300004 ER PT J AU CAIRD, JA RAMPONI, AJ STAVER, PR AF CAIRD, JA RAMPONI, AJ STAVER, PR TI QUANTUM EFFICIENCY AND EXCITED-STATE RELAXATION DYNAMICS IN NEODYMIUM-DOPED PHOSPHATE LASER GLASSES SO JOURNAL OF THE OPTICAL SOCIETY OF AMERICA B-OPTICAL PHYSICS LA English DT Article ID RARE-EARTH IONS; ENERGY MIGRATION; GAIN SATURATION; ND-3+ IONS; ND-YAG; DECAY AB Radiometrically calibrated spectroscopic techniques employing an integrating-sphere detection system have been used to determine the fluorescence quantum efficiencies for two commercially available Nd3+-doped phosphate laser glasses, LG-750 and LG-760. Quantum efficiencies and fluorescence lifetimes were measured for samples with various neodymium concentrations. It is shown that the effects of concentration quenching are accurately described when both resonant nonradiative excitation hopping (the Burshtein model) and annihilation by cross relaxation are accounted for by Foster-Dexter dipole-dipole energy-transfer theory. The Forster-Dexter critical range for nonradiative excitation hopping was found to be R(DD) = 11 angstrom, while the critical range for cross relaxation was close to R(DA) = 4 angstrom in these glasses. The quantum efficiency at low Nd3+ concentrations was (92 +/- 5)%, implying a nonradiative relaxation rate of 210 +/- 150 s-1 for isolated ions. Improved values for the radiative lifetimes and the stimulated emission cross sections for these glasses were also deduced from the measurements. RP CAIRD, JA (reprint author), UNIV CALIF LAWRENCE LIVERMORE NATL LAB,LAWRENCE LIVERMORE NATL LAB,POB 808,LIVERMORE,CA 94551, USA. NR 58 TC 132 Z9 132 U1 3 U2 19 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 JUL PY 1991 VL 8 IS 7 BP 1391 EP 1403 DI 10.1364/JOSAB.8.001391 PG 13 WC Optics SC Optics GA FV323 UT WOS:A1991FV32300005 ER PT J AU LAWSON, JK PAYNE, SA AF LAWSON, JK PAYNE, SA TI EXCITED-STATE ABSORPTION-SPECTRA AND GAIN MEASUREMENTS OF CAF2-SM-2+ SO JOURNAL OF THE OPTICAL SOCIETY OF AMERICA B-OPTICAL PHYSICS LA English DT Article ID ALKALINE-EARTH FLUORIDES; ELECTRONIC-STRUCTURE; BAND-STRUCTURE; CRYSTALS; CAF2; IONS; SPECTROSCOPY; THRESHOLDS; LASER; SM-2+ AB We have measured the pump-probe spectrum for CaF2: Sm2+ over a wide (360-1020 nm) spectral range. We observed gain throughout most of the 730-nm emission band, although there is some evidence of excited-state absorption (ESA) in this region. A much stronger ESA was observed near 500 nm. The temperature dependence of the ESA signal clearly indicates that the absorption is associated with divalent samarium. Because of the width and strength of this transition, we assign the ESA to a 4f(5)5d --> conduction band transition. We calculated the oscillator strength for this ESA band to be 0.10 and rationalized its magnitude based on an intensity-borrowing mechanism that involves the transition from the valence band to the conduction band. RP LAWSON, JK (reprint author), UNIV CALIF LAWRENCE LIVERMORE NATL LAB,POB 5508,L-490,LIVERMORE,CA 94550, USA. NR 50 TC 28 Z9 28 U1 0 U2 7 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 JUL PY 1991 VL 8 IS 7 BP 1404 EP 1405 DI 10.1364/JOSAB.8.001404 PG 2 WC Optics SC Optics GA FV323 UT WOS:A1991FV32300006 ER PT J AU FURMAN, NS AF FURMAN, NS TI AMERICAN-INDIAN TRIBAL GOVERNMENTS - OBRIEN,S SO JOURNAL OF THE WEST LA English DT Book Review RP FURMAN, NS (reprint author), SANDIA NATL LABS,ALBUQUERQUE,NM 87185, USA. NR 1 TC 0 Z9 0 U1 0 U2 0 PU J WEST INC PI MANHATTAN PA P O BOX 1009 1531 YUMA, MANHATTAN, KS 66502 SN 0022-5169 J9 J WEST JI J. West PD JUL PY 1991 VL 30 IS 3 BP 107 EP 107 PG 1 WC History SC History GA GA279 UT WOS:A1991GA27900038 ER PT J AU Torczynski, JR AF Torczynski, J. R. TI Heat Transfer Regimes in Nuclear-Reactor-Pumped Gas Lasers SO JOURNAL OF THERMOPHYSICS AND HEAT TRANSFER LA English DT Article AB The flow induced in nuclear-reactor-pumped gas lasers by spatially nonuniform fission-fragment heating and by heat transfer to the walls is examined. The equations of motion are acoustically filtered, and the resulting equations have three time scales: the heating duration, the time over which an O (1) pressure rise is produced, and the thermal boundary-layer growth time. Three distinct regimes emerge from consideration of the relative magnitudes of these time scales. In the negligible-condition regime, heating nonuniformity determines the motion. In the dominant-conduction regime, thermal-conduction effects govern the motion. In the mixed regime, both effects are comparable but oppositely directed, producing a complex motion. Analytical solutions for the motion and for partial derivative(2)rho/partial derivative x(2) (used in optical analyses) are presented for the first two regimes, and numerical examples are given for all three. C1 Sandia Natl Labs, Fluid & Thermal Sci Dept, Albuquerque, NM 87185 USA. RP Torczynski, JR (reprint author), Sandia Natl Labs, Fluid & Thermal Sci Dept, Div 1512, Albuquerque, NM 87185 USA. NR 28 TC 5 Z9 5 U1 0 U2 1 PU AMER INST AERONAUT ASTRONAUT PI RESTON PA 1801 ALEXANDER BELL DRIVE, STE 500, RESTON, VA 22091-4344 USA SN 0887-8722 J9 J THERMOPHYS HEAT TR JI J. Thermophys. Heat Transf. PD JUL-SEP PY 1991 VL 5 IS 3 BP 318 EP 326 DI 10.2514/3.266 PG 9 WC Thermodynamics; Engineering, Mechanical SC Thermodynamics; Engineering GA V24ZW UT WOS:000208449300008 ER PT J AU Chappidi, PR Gunnerson, FS Pasamehmetoglu, KO AF Chappidi, P. R. Gunnerson, F. S. Pasamehmetoglu, K. O. TI Subcooled Forced Convection Film Boiling Drag and Heat Transfer of a Wedge SO JOURNAL OF THERMOPHYSICS AND HEAT TRANSFER LA English DT Article AB Subcooled laminar forced convection film boiling flow on a wedge is analyzed considering the streamwise pressure gradient imposed on the flow and the streamwise buoyancy force acting on the vapor film. A two-phase boundary-layer model is proposed, and the local similarity concept is applied to obtain an approximate solution of the governing equations. For a water-steam system at atmospheric pressure considered within this study, wall skin friction results display a strong dependency on the streamwise buoyancy force driving the vapor film and the external pressure gradient. Adverse streamwise buoyancy force acting on the vapor film, which is the case on the lower surface of a horizontally aligned wedge, may cause vapor flow separation. In contrast to wall skin friction dependency, the wall heat transfer parameter shows a secondary dependence on the streamwise pressure gradient and the buoyancy force. C1 [Chappidi, P. R.] Los Alamos Natl Lab, Nucl Technol & Engn Div, Engn & Soc Anal Grp, Los Alamos, NM 87545 USA. [Gunnerson, F. S.] Univ Cent Florida, Dept Mech Engn, Orlando, FL 32816 USA. RP Chappidi, PR (reprint author), Los Alamos Natl Lab, Nucl Technol & Engn Div, Engn & Soc Anal Grp, MSK 557, Los Alamos, NM 87545 USA. NR 15 TC 0 Z9 0 U1 0 U2 2 PU AMER INST AERONAUT ASTRONAUT PI RESTON PA 1801 ALEXANDER BELL DRIVE, STE 500, RESTON, VA 22091-4344 USA SN 0887-8722 J9 J THERMOPHYS HEAT TR JI J. Thermophys. Heat Transf. PD JUL-SEP PY 1991 VL 5 IS 3 BP 355 EP 365 DI 10.2514/3.271 PG 11 WC Thermodynamics; Engineering, Mechanical SC Thermodynamics; Engineering GA V24ZW UT WOS:000208449300013 ER PT J AU WRUCK, DA DIXON, MA RUBIN, M BOGY, SN AF WRUCK, DA DIXON, MA RUBIN, M BOGY, SN TI AS-SPUTTERED ELECTROCHROMIC FILMS OF NICKEL-OXIDE SO JOURNAL OF VACUUM SCIENCE & TECHNOLOGY A-VACUUM SURFACES AND FILMS LA English DT Article ID ENERGY-EFFICIENT WINDOWS; OPTICAL-PROPERTIES; COATINGS AB Electrochromic nickel oxide films were deposited by radio-frequency magnetron sputtering of a Ni target in gas mixtures of Ar and O2. When electrochemically cycled in 0.1 N KOH solution, large reversible changes in visible absorption were obtained within the first 10 bleach/color cycles. Films which showed the greatest changes in optical properties and charge capacity were produced within a narrow range of oxygen flow rates. The coloration efficiency was found to be insensitive to the sputtering conditions and stoichiometry, with a value of 34 +/- 4 cm2C-1 at 550 nm. This indicates that microstructure and charge capacity determine the absorption coefficient. The reaction rate was found to depend on the concentration of OH- in the electrolyte, indicating that OH- diffusion in the electrolyte limits the rate of reaction. RP WRUCK, DA (reprint author), UNIV CALIF BERKELEY LAWRENCE BERKELEY LAB,DIV APPL SCI,BERKELEY,CA 94720, USA. NR 15 TC 41 Z9 41 U1 0 U2 6 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 JUL-AUG PY 1991 VL 9 IS 4 BP 2170 EP 2173 DI 10.1116/1.577245 PG 4 WC Materials Science, Coatings & Films; Physics, Applied SC Materials Science; Physics GA FV995 UT WOS:A1991FV99500015 ER PT J AU VANDENTOP, GJ NASCENTE, PAP KAWASAKI, M OGLETREE, DF SOMORJAI, GA SALMERON, M AF VANDENTOP, GJ NASCENTE, PAP KAWASAKI, M OGLETREE, DF SOMORJAI, GA SALMERON, M TI OBSERVATION OF THE INITIAL-STAGES OF GROWTH OF HYDROGENATED AMORPHOUS-CARBON FILMS BY SCANNING TUNNELING MICROSCOPY SO JOURNAL OF VACUUM SCIENCE & TECHNOLOGY A-VACUUM SURFACES AND FILMS LA English DT Article ID ELECTRON; SURFACE; TEMPERATURE; TERMINATION; DISCHARGE; SILICON AB Scanning tunneling microscopy was used to investigate the initial stages of growth of hydrogenated amorphous carbon (a-C:H) films. The films were deposited on highly oriented pyrolytic graphite and silicon substrates both on the powered (negatively self-biased) and grounded electrodes from a methane rf plasma (13.56 MHz) at 68-70 mTorr and room temperature. On graphite substrates, films formed at the powered electrode were observed to nucleate in clusters approximately 50 angstrom in diameter. Cluster density increased with deposition time, while cluster size remained relatively constant. The atomic structure of individual clusters was resolved and found to be amorphous, containing areas of both five- and sixfold rings in a disordered matrix. No long-range order was observed. The C-H bonding in these clusters was observed by high-resolution electron-energy-loss spectroscopy. Films formed on graphite substrates placed at the grounded electrode produced very noisy images due to an unstable tunneling gap, indicative of the material's poor electrical conductivity. On silicon substrates placed at the powered electrode, cluster formation was not observed, and the films formed were measured to be flat to within 3-angstrom rms. The clusters formed on graphite at the powered electrode may be initiated by nucleation sites created by high-energy ion bombardment. Due to the higher reactivity of silicon, growth onto these substrates proceeds without the requirement of ion bombardment nucleation sites, thus the more homogeneous growth on silicon. C1 UNIV CALIF BERKELEY LAWRENCE BERKELEY LAB,CTR ADV MAT MAT,DIV CHEM,BERKELEY,CA 94720. UNIV CALIF BERKELEY,DEPT CHEM,BERKELEY,CA 94720. RI Ogletree, D Frank/D-9833-2016 OI Ogletree, D Frank/0000-0002-8159-0182 NR 19 TC 30 Z9 30 U1 0 U2 2 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 JUL-AUG PY 1991 VL 9 IS 4 BP 2273 EP 2278 DI 10.1116/1.577308 PG 6 WC Materials Science, Coatings & Films; Physics, Applied SC Materials Science; Physics GA FV995 UT WOS:A1991FV99500033 ER PT J AU DRAPER, BL HILL, TA AF DRAPER, BL HILL, TA TI STRESS AND STRESS-RELAXATION IN INTEGRATED-CIRCUIT METALS AND DIELECTRICS SO JOURNAL OF VACUUM SCIENCE & TECHNOLOGY B LA English DT Article ID THERMAL-STRESS; ALUMINUM FILMS; METALLIZATIONS; INTERCONNECTS AB In order to provide data needed in the investigation and modeling of stress voiding in integrated circuit metallizations, stress and stress relaxation in Al/Si/Cu alloys and common dielectrics were studied as a function of storage temperature and deposition conditions. It was found that the room-temperature tensile stress in Al/Si/Cu increases with increasing substrate bias and deposition temperature, and that the isothermal relaxation rate upon cooling from 400-degrees-C is sharply dependent on temperature. The activation energy for the relaxation process was found to be 0.39 eV above 130-degrees-C and about 0.08 eV at lower temperatures. For insulating layers deposited with plasma-enhanced chemical-vapor deposition techniques, strong correlations were found among stress, density, hydrogen content, deposition temperature, and film composition (oxides, nitrides, and several intermediate oxynitrides), with the highest levels of compressive stress (near 1 GPa) being measured in nitride films deposited at 300-degrees-C. These films, as well as phosphorus-doped glasses used as capping/protection layers, were found to undergo structural changes upon post-deposition thermal cycling which affected stress levels. RP DRAPER, BL (reprint author), SANDIA NATL LABS,ALBUQUERQUE,NM 87185, USA. NR 18 TC 3 Z9 3 U1 1 U2 3 PU AMER INST PHYSICS PI WOODBURY PA CIRCULATION FULFILLMENT DIV, 500 SUNNYSIDE BLVD, WOODBURY, NY 11797-2999 SN 1071-1023 J9 J VAC SCI TECHNOL B JI J. Vac. Sci. Technol. B PD JUL-AUG PY 1991 VL 9 IS 4 BP 1956 EP 1962 DI 10.1116/1.585387 PG 7 WC Engineering, Electrical & Electronic; Nanoscience & Nanotechnology; Physics, Applied SC Engineering; Science & Technology - Other Topics; Physics GA GB897 UT WOS:A1991GB89700009 ER PT J AU SPINDT, CJ YAMADA, M MEISSNER, PL MIYANO, KE HERRERA, A SPICER, WE ARKO, AJ AF SPINDT, CJ YAMADA, M MEISSNER, PL MIYANO, KE HERRERA, A SPICER, WE ARKO, AJ TI AU AND AL SCHOTTKY-BARRIER FORMATION ON GAAS (100) SURFACES PREPARED BY THERMAL-DESORPTION OF A PROTECTIVE ARSENIC COATING SO JOURNAL OF VACUUM SCIENCE & TECHNOLOGY B LA English DT Article ID METAL-SEMICONDUCTOR INTERFACE; AU-GAAS(110) INTERFACE; TEMPERATURE; TRANSITION; OVERLAYERS; CONTACTS; HEIGHT; MODEL AB Soft x-ray photoemission spectroscopy has been used to investigate the initial stages of Schottky barrier formation on GaAs (100) surfaces prepared by the thermal desorption of an As cap. This work was motivated by a previous study [Brillson et al., J. Vac. Sci. Technol. B 6, 1263 (1988)] of identically grown and capped samples which reported "unpinned" Schottky barrier formation, with barrier heights falling over a wide range (0.75 eV) of energies. This large energy range is a striking result, as a considerable number of prior studies on both (110) and (100) surfaces have found that all metals will pin in a narrow (0.25 eV) range near midgap. Since Au and Al are the extremes of the larger 0.75 eV span of Schottky barriers, we have studied the deposition of these two metals. We found that the barrier height measurements on the low doped n-type samples used in this work and in the paper referenced above are affected by photovoltaic effects, even at room temperature. These photovoltaic effects cause shifts in the band bending, which are an artifact of the measurement. We also performed measurements on more heavily doped samples, and the photovoltaic effects were removed. In addition, we point out that Au-Ga alloying makes the case of Au potentially misleading. With the photovoltaic effects removed, and the Au-Ga alloying carefully accounted for, we found that the barriers heights for Au and Al differ by only 0.25 eV. C1 UNIV CALIF LOS ALAMOS SCI LAB,LOS ALAMOS,NM 87545. RP SPINDT, CJ (reprint author), STANFORD UNIV,STANFORD ELECTR LABS,STANFORD,CA 94305, USA. NR 18 TC 17 Z9 17 U1 0 U2 3 PU AMER INST PHYSICS PI WOODBURY PA CIRCULATION FULFILLMENT DIV, 500 SUNNYSIDE BLVD, WOODBURY, NY 11797-2999 SN 1071-1023 J9 J VAC SCI TECHNOL B JI J. Vac. Sci. Technol. B PD JUL-AUG PY 1991 VL 9 IS 4 BP 2090 EP 2094 DI 10.1116/1.585780 PG 5 WC Engineering, Electrical & Electronic; Nanoscience & Nanotechnology; Physics, Applied SC Engineering; Science & Technology - Other Topics; Physics GA GB897 UT WOS:A1991GB89700031 ER PT J AU FROYEN, S ZUNGER, A AF FROYEN, S ZUNGER, A TI SURFACE RECONSTRUCTIONS AND SURFACE ENERGIES OF MONOLAYER-COVERAGE CATION-TERMINATED GA0.5IN0.5P(001) SURFACES SO JOURNAL OF VACUUM SCIENCE & TECHNOLOGY B LA English DT Article ID ISOVALENT INTERSEMICONDUCTOR ALLOYS; MOLECULAR-BEAM EPITAXY; SEMICONDUCTORS AB Using the first-principles pseudopotential method we have studied the fully covered cation-terminated (001) surfaces of Ga0.5In0.5P alloys. We find that among several possible Ga and In surface patterns (within a 2 x 2 unit cell), the one corresponding to CuPt-like bulk ordering is stabilized by approximately 100 meV per surface atom. This structure has been observed experimentally in thick films, yet is known to be bulk unstable. The stability of a CuPt-like surface layer is related to electronically driven surface reconstructions-dimerization, buckling, and tilting-which are discussed in detail. RP FROYEN, S (reprint author), SOLAR ENERGY RES INST,GOLDEN,CO 80401, USA. RI Zunger, Alex/A-6733-2013 NR 17 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 1071-1023 J9 J VAC SCI TECHNOL B JI J. Vac. Sci. Technol. B PD JUL-AUG PY 1991 VL 9 IS 4 BP 2176 EP 2181 DI 10.1116/1.585760 PG 6 WC Engineering, Electrical & Electronic; Nanoscience & Nanotechnology; Physics, Applied SC Engineering; Science & Technology - Other Topics; Physics GA GB897 UT WOS:A1991GB89700047 ER PT J AU GODIN, TJ LAFEMINA, JP DUKE, CB AF GODIN, TJ LAFEMINA, JP DUKE, CB TI DYNAMIC STRAIN AT SEMICONDUCTOR INTERFACES - STRUCTURE AND SURFACE-ATOM VIBRATIONS OF GAAS(110) AND GAAS(110)-P(1X1)-SB SO JOURNAL OF VACUUM SCIENCE & TECHNOLOGY B LA English DT Article ID III-V-SEMICONDUCTORS; 110 SURFACES; COMPOUND SEMICONDUCTORS; ELECTRONIC-STRUCTURE; ENERGY-MINIMIZATION; SB OVERLAYERS; PHONONS; GEOMETRY; BISMUTH AB The dynamical force fields of the clean GaAs(110) surface, an isolated Sb chain, and the GaAs(110)-p(1 x 1)-Sb(1-ML) interface have been computed utilizing tight-binding total energy models that have been used successfully to describe the atomic and electronic structure of the clean and adsorbed cleavage faces of the tetrahedrally coordinated compound semiconductors. Since the main consequences of the different chemical bonding in these two cases are manifested in changes in the force field associated with the dynamics of the top-layer atoms, we explore these consequences using a restricted dynamical model in which only the top-layer atoms are allowed to vibrate. The resulting vibrational energies are in remarkably good agreement with experimental measurements, and hence afford a vehicle to obtain quantitative relationships between the nature of the surface chemical bonds and the vibrational energies of the surface atomic species. C1 XEROX CORP, WEBSTER RES CTR, WEBSTER, NY 14580 USA. RP GODIN, TJ (reprint author), PACIFIC NW LAB, MOLEC SCI RES CTR, RICHLAND, WA 99352 USA. NR 24 TC 28 Z9 28 U1 0 U2 0 PU A V S AMER INST PHYSICS PI MELVILLE PA STE 1 NO 1, 2 HUNTINGTON QUADRANGLE, MELVILLE, NY 11747-4502 USA SN 1071-1023 J9 J VAC SCI TECHNOL B JI J. Vac. Sci. Technol. B PD JUL-AUG PY 1991 VL 9 IS 4 BP 2282 EP 2289 DI 10.1116/1.585734 PG 8 WC Engineering, Electrical & Electronic; Nanoscience & Nanotechnology; Physics, Applied SC Engineering; Science & Technology - Other Topics; Physics GA GB897 UT WOS:A1991GB89700065 ER PT J AU KENDELEWICZ, T WOICIK, JC MIYANO, KE COWAN, PL KARLIN, BA BOULDIN, CE PIANETTA, P SPICER, WE AF KENDELEWICZ, T WOICIK, JC MIYANO, KE COWAN, PL KARLIN, BA BOULDIN, CE PIANETTA, P SPICER, WE TI SYNCHROTRON X-RAY STANDING-WAVE STUDY OF SB ON GAAS(110) AND INP(110) SO JOURNAL OF VACUUM SCIENCE & TECHNOLOGY B LA English DT Article ID ENERGY ELECTRON-DIFFRACTION; SURFACE REGISTRATION PROBLEM; RADIATION BEAMLINE; 110 SURFACES; ANTIMONY; SEMICONDUCTORS; OVERLAYERS; RESOLUTION AB The soft x-ray standing-wave technique has been used to study ordered monolayers of Sb on GaAs(110) and InP(110). Using the back-reflection diffraction geometry from (220) planes, we determine the perpendicular distances of Sb atoms to the substrate and compare these with theoretical calculations and elastic low-energy electron diffraction determinations. The various models of Sb chemisorption are evaluated on the basis of our data. C1 NATL INST STAND & TECHNOL,GAITHERSBURG,MD 20899. BROOKHAVEN NATL LAB,NATL SYNCHROTRON RADIAT LIGHT SOURCE,UPTON,NY 11973. RP KENDELEWICZ, T (reprint author), STANFORD UNIV,STANFORD ELECTR LABS,STANFORD,CA 94305, USA. NR 22 TC 13 Z9 13 U1 1 U2 1 PU AMER INST PHYSICS PI WOODBURY PA CIRCULATION FULFILLMENT DIV, 500 SUNNYSIDE BLVD, WOODBURY, NY 11797-2999 SN 1071-1023 J9 J VAC SCI TECHNOL B JI J. Vac. Sci. Technol. B PD JUL-AUG PY 1991 VL 9 IS 4 BP 2290 EP 2293 DI 10.1116/1.585735 PG 4 WC Engineering, Electrical & Electronic; Nanoscience & Nanotechnology; Physics, Applied SC Engineering; Science & Technology - Other Topics; Physics GA GB897 UT WOS:A1991GB89700066 ER PT J AU LILIENTALWEBER, Z COOPER, G MARIELLA, R KOCOT, C AF LILIENTALWEBER, Z COOPER, G MARIELLA, R KOCOT, C TI THE ROLE OF AS IN MOLECULAR-BEAM EPITAXY GAAS-LAYERS GROWN AT LOW-TEMPERATURE SO JOURNAL OF VACUUM SCIENCE & TECHNOLOGY B LA English DT Article ID BUFFER AB Annealed GaAs layers grown at low temperatures (180-300-degrees-C) by molecular-beam epitaxy (MBE) were studied by transmission electron microscopy (TEM). These layers were used as buffers for a field-effect transistor (FET) device structure and effectively eliminated sidegating effects. All these layers were found to contain As precipitates. Precipitate size and separation between them differed from sample to sample. The smallest precipitates were coherent "pseudocubic." Larger precipitates had hexagonal structure. The distance between precipitates was estimated to be in the range of 10-40 nm. These results are consistent with the buried Schottky model by Warren et al., although other explanations cannot be excluded at present. C1 UNIV CALIF LAWRENCE LIVERMORE NATL LAB,LIVERMORE,CA 94550. HEWLETT PACKARD CO,PALO ALTO,CA 94304. RP LILIENTALWEBER, Z (reprint author), UNIV CALIF BERKELEY,LAWRENCE BERKELEY LAB 62-203,DIV MAT SCI,BERKELEY,CA 94720, USA. RI Liliental-Weber, Zuzanna/H-8006-2012 NR 11 TC 30 Z9 30 U1 1 U2 5 PU AMER INST PHYSICS PI WOODBURY PA CIRCULATION FULFILLMENT DIV, 500 SUNNYSIDE BLVD, WOODBURY, NY 11797-2999 SN 1071-1023 J9 J VAC SCI TECHNOL B JI J. Vac. Sci. Technol. B PD JUL-AUG PY 1991 VL 9 IS 4 BP 2323 EP 2327 DI 10.1116/1.585741 PG 5 WC Engineering, Electrical & Electronic; Nanoscience & Nanotechnology; Physics, Applied SC Engineering; Science & Technology - Other Topics; Physics GA GB897 UT WOS:A1991GB89700072 ER PT J AU WOLFORD, DJ GILLILAND, GD KUECH, TF SMITH, LM MARTINSEN, J BRADLEY, JA TSANG, CF VENKATASUBRAMANIAN, R GHANDI, SK HJALMARSON, HP AF WOLFORD, DJ GILLILAND, GD KUECH, TF SMITH, LM MARTINSEN, J BRADLEY, JA TSANG, CF VENKATASUBRAMANIAN, R GHANDI, SK HJALMARSON, HP TI INTRINSIC RECOMBINATION AND INTERFACE CHARACTERIZATION IN SURFACE-FREE GAAS STRUCTURES SO JOURNAL OF VACUUM SCIENCE & TECHNOLOGY B LA English DT Article ID MINORITY-CARRIER LIFETIME; PHOTOLUMINESCENCE; PASSIVATION; ABSORPTION; EPITAXY AB We have conducted a thorough photoluminescence (PL) and PL time-decay study of the interfacial passivating effects of metalorganic chemical vapor deposition prepared Al0.3Ga0.7As, n+-doped GaAs, and Na2S surface barriers on epitaxial, high-purity (n-) GaAs structures. We observe 300-K radiative lifetimes, in such 10-mu-m structures, of 2.5-mu-s, 800 ns, and 150 ns, respectively. These are to be compared with lifetimes of approximately 2 ns for a single, "bare" GaAs surface with an Al0.3Ga0.7As rear surface barrier, and approximately 0.5 ns for unpassivated epitaxial GaAs. Accompanying radiative efficiencies are 10(3)-10(4) higher in all of these epibased structures, and 10(2) higher for Na2S, than for corresponding bare GaAs surfaces. Further, from detailed PL lifetime studies versus GaAs thickness, we find the lowest interfacial recombination velocities reported for any GaAs/Al(x)Ga1-xAs structure, to date, of less-than-or-similar-to 40 cm/s, and, correspondingly, 0-1800 cm/s for n+/n-/n+ all-GaAs homostructures. Thus, virtually "surface-free" structures are now achievable. In comparison, we find, at best, approximately 5500 cm/s for Na2S, and typically 34 000 cm/s for bare GaAs surfaces. We conclude, on the basis of our detailed experimental study of a wide variety of samples, that these values provide truly reliable measures of surface recombination velocities for both surface types. We find an unambiguous determination of surface recombination velocities requires detailed examination of the minority-carrier recombination kinetics versus temperature, together with minority-carrier spatial transport properties. After demonstrating that minority-carrier recombination kinetics in our ideal structures are truly "intrinsic," and thus wholly unaffected by extrinsic processes, we examine the temperature dependence of band-to-band and free-exciton recombination. We fully explain all intrinsic, free-carrier recombination found in each structure, for temperatures of 40-300 K through rate equations appropriate to each structure. Similar low-temperature (1.8-40 K) studies confirm dominant decay proceeds, here, by intrinsic free excitons. C1 RENSSELAER POLYTECH INST,TROY,NY 12180. SANDIA NATL LABS,ALBUQUERQUE,NM 87185. RP WOLFORD, DJ (reprint author), IBM CORP,THOMAS J WATSON RES CTR,DIV RES,YORKTOWN HTS,NY 10598, USA. RI Smith, Leigh/A-1071-2009 OI Smith, Leigh/0000-0002-3950-1713 NR 19 TC 36 Z9 36 U1 0 U2 11 PU AMER INST PHYSICS PI WOODBURY PA CIRCULATION FULFILLMENT DIV, 500 SUNNYSIDE BLVD, WOODBURY, NY 11797-2999 SN 1071-1023 J9 J VAC SCI TECHNOL B JI J. Vac. Sci. Technol. B PD JUL-AUG PY 1991 VL 9 IS 4 BP 2369 EP 2376 DI 10.1116/1.585705 PG 8 WC Engineering, Electrical & Electronic; Nanoscience & Nanotechnology; Physics, Applied SC Engineering; Science & Technology - Other Topics; Physics GA GB897 UT WOS:A1991GB89700080 ER PT J AU THOMAS, DJ WALL, JS HAINFELD, JF KACZOREK, M BOOY, FP TRUS, BL EISERLING, FA STEVEN, AC AF THOMAS, DJ WALL, JS HAINFELD, JF KACZOREK, M BOOY, FP TRUS, BL EISERLING, FA STEVEN, AC TI GP160, THE ENVELOPE GLYCOPROTEIN OF HUMAN-IMMUNODEFICIENCY-VIRUS TYPE-1, IS A DIMER OF 125-KILODALTON SUBUNITS STABILIZED THROUGH INTERACTIONS BETWEEN THEIR GP41 DOMAINS SO JOURNAL OF VIROLOGY LA English DT Article ID TRANSMISSION ELECTRON-MICROSCOPE; HAMSTER OVARY CELLS; OLIGOMERIC STRUCTURE; GLUTAMINE-SYNTHETASE; NUCLEOTIDE-SEQUENCE; AIDS PATIENTS; HTLV-III; HIV; PROTEIN; ANTIBODIES AB The molecular masses, carbohydrate contents, oligomeric status, and overall molecular structure of the env glycoproteins of human immunodeficiency virus type 1-gp120, gp160, and gp41-have been determined by quantitative electron microscopy. Using purified gp160s, a water-soluble form of env purified from a recombinant vaccinia virus expression system, we have measured the masses of several hundred individual molecules by dark-field scanning transmission electron microscopy. When combined with sequence-based information, these mass measurements establish that gp160s is a dimer of subunits with an average monomer mass of 123 kDa, of which approximately 32 kDa is carbohydrate and 91 kDa is protein. Similarly, gp120 was found to be a monomer of 89 kDa and to contain virtually all of env's glycosylation. gp41 is glycosylated only slightly, if at all, and is responsible for the interactions that stabilize the gp160s dimer. A molecular mass map of gp160s derived by image processing depicts an asymmetric dumbbell whose two domains have masses of approximately 173 and approximately 73 kDa, corresponding to a gp120 dimer and a gp41 dimer, respectively. We infer that the average monomer mass of native gp160 is 125 kDa and that in situ, env is either a dimer or a tetramer but is most unlikely to be a trimer. C1 NIAMSD,STRUCT BIOL RES LAB,BLDG 6,ROOM 114,BETHESDA,MD 20892. NIH,DIV COMP RES & TECHNOL,BETHESDA,MD 20892. UNIV RENNES 1,BIOL CELLULAIRE LAB,CNRS,URA 256,F-35042 RENNES,FRANCE. PASTEUR MERIEUX,RES & DEV,F-27101 VAL DE REUIL,FRANCE. BROOKHAVEN NATL LAB,DEPT BIOL,UPTON,NY 11973. UNIV CALIF LOS ANGELES,DEPT MOLEC BIOL,LOS ANGELES,CA 90024. FU NCRR NIH HHS [RR01777]; NIAID NIH HHS [AI25319] NR 46 TC 70 Z9 70 U1 0 U2 1 PU AMER SOC MICROBIOLOGY PI WASHINGTON PA 1325 MASSACHUSETTS AVENUE, NW, WASHINGTON, DC 20005-4171 SN 0022-538X J9 J VIROL JI J. Virol. PD JUL PY 1991 VL 65 IS 7 BP 3797 EP 3803 PG 7 WC Virology SC Virology GA FQ940 UT WOS:A1991FQ94000047 PM 2041094 ER PT J AU LEITNER, LA DUNN, CP GUNTENSPERGEN, GR STEARNS, F SHARPE, DM AF LEITNER, LA DUNN, CP GUNTENSPERGEN, GR STEARNS, F SHARPE, DM TI EFFECTS OF SITE, LANDSCAPE FEATURES, AND FIRE REGIME ON VEGETATION PATTERNS IN PRESETTLEMENT SOUTHERN WISCONSIN SO LANDSCAPE ECOLOGY LA English DT Article DE DISTURBANCE; FIRE; HETEROGENEITY; LANDSCAPE PATTERN; TOPOGRAPHY; WISCONSIN AB The presettlement tree cover (1831-33) of 3 townships in a southern Wisconsin landscape was analyzed using original survey records. Four forest types were identified: closed forest, open forest, savanna, and prairie. Comparisons of vegetation types and landscape pattern were made between the east and west sides of the Pecatonica River, which bisects the landscape and could have acted as a natural fire barrier. West of the river, presettlement tree species richness and diversity were lower and trees were smaller in diameter and less dense than to the east. The major vegetation types to the west were prairie (42% of landscape) and savanna (40%), both fire-susceptible types. Prairie was more common on gentle slopes than on other landforms. To the east, the landscape was 70% forested (closed plus open forest). Here, prairie was more frequent on steep dry sites. These vegetation differences, including the contrasting landscape placement of prairie, are attributed to distinct site characteristics and to disturbance (fire) regimes, with the west likely having more frequent fires. In terms of the four vegetation types, the east landscape was more homogeneous, being dominated by closed forest (50%). West of the Pecatonica River, the landscape was more heterogeneous because of the high proportion of both prairie and savanna; however, in terms of flammability of vegetation, the west was essentially homogeneous (82% prairie plus savanna). C1 ARGONNE NATL LAB, DIV ENVIRONM ASSESSMENT & INFORMAT SCI, ARGONNE, IL 60439 USA. US FISH & WILDLIFE SERV, NATL WETLANDS RES CTR, SLIDELL, LA 70458 USA. N CENT FOREST EXPT STN, FORESTRY SCI LAB, RHINELANDER, WI 54501 USA. SO ILLINOIS UNIV, DEPT GEOG, CARBONDALE, IL 62901 USA. RP LEITNER, LA (reprint author), UNIV WISCONSIN, DEPT BIOL SCI, POB 413, MILWAUKEE, WI 53201 USA. NR 0 TC 45 Z9 46 U1 0 U2 8 PU SPRINGER PI DORDRECHT PA VAN GODEWIJCKSTRAAT 30, 3311 GZ DORDRECHT, NETHERLANDS SN 0921-2973 J9 LANDSCAPE ECOL JI Landsc. Ecol. PD JUL PY 1991 VL 5 IS 4 BP 203 EP 217 DI 10.1007/BF00141435 PG 15 WC Ecology; Geography, Physical; Geosciences, Multidisciplinary SC Environmental Sciences & Ecology; Physical Geography; Geology GA GG213 UT WOS:A1991GG21300002 ER PT J AU KING, AW JOHNSON, AR ONEILL, RV AF KING, AW JOHNSON, AR ONEILL, RV TI TRANSMUTATION AND FUNCTIONAL REPRESENTATION OF HETEROGENEOUS LANDSCAPES SO LANDSCAPE ECOLOGY LA English DT Article AB Models of local small-scale ecological processes can be used to describe related processes at larger spatial scales if the influences of increased scale and heterogeneity are carefully considered. In this paper we consider the changes in the functional representation of an ecological process that can occur as one moves from a local small-scale model to a model of the aggregate expression of that process for a larger spatial extent. We call these changes "spatial transmutation". We specifically examine landscape heterogeneity as a cause of transmutation. Spatial transmutation as a consequence of landscape heterogeneity is a source of error in the prediction of aggregate landscape behavior from smaller scale models. However, we also demonstrate a procedure for taking advantage of spatial transmutation to develop appropriately scaled landscape functions. First a mathematical function describing the process of interest as a local function of local variables is defined. The spatial heterogeneity of the local variables is described by their statistical distribution in the landscape. The aggregate landscape expression of the local process is then predicted by calculating the expected value of the local function, explicitly integrating landscape heterogeneity. Monte Carlo simulation is used to repeat the local-to-landscape extrapolation for a variety of landscape patterns. Finally, the extrapolated landscape results are regressed on landscape variables to define response functions that explain a useful fraction of the total variation in landscape behavior. The response functions are hypotheses about the functional representation of the local process at the larger spatial scale. RP KING, AW (reprint author), OAK RIDGE NATL LAB, DIV ENVIRONM SCI, POB 2008, OAK RIDGE, TN 37830 USA. NR 0 TC 57 Z9 60 U1 0 U2 1 PU SPRINGER PI DORDRECHT PA VAN GODEWIJCKSTRAAT 30, 3311 GZ DORDRECHT, NETHERLANDS SN 0921-2973 J9 LANDSCAPE ECOL JI Landsc. Ecol. PD JUL PY 1991 VL 5 IS 4 BP 239 EP 253 DI 10.1007/BF00141438 PG 15 WC Ecology; Geography, Physical; Geosciences, Multidisciplinary SC Environmental Sciences & Ecology; Physical Geography; Geology GA GG213 UT WOS:A1991GG21300005 ER PT J AU WILLIAMS, JM AF WILLIAMS, JM TI HIGH INTERNAL PHASE WATER-IN-OIL EMULSIONS - INFLUENCE OF SURFACTANTS AND COSURFACTANTS ON EMULSION STABILITY AND FOAM QUALITY SO LANGMUIR LA English DT Article ID MICROCELLULAR FOAMS; MICROSTRUCTURES AB The relationship between the hydrophilic-lipophilic balance (HLB) number of a cosurfactant and the stability of a styrene-based emulsion is studied for 8 surfactants and 22 cosurfactants. The amount of cosurfactant that can be incorporated into a water-in-oil emulsion is strongly and inversely coupled to the HLB number of the cosurfactant with a correlation of 96%. The higher the HLB number the smaller the amount of cosurfactant required to form large, coalesced droplets in the emulsion and, hence, in the ultimate polymeric foam. Methanol is an obvious deviant from the typical HLB number-related, cosurfactant disintegration of the sorbitan monooleate containing emulsions. Some modifications to the literature assignments of HLB numbers are recommended. A mechanism is presented for the dual droplet distribution observed for nonionic cosurfactants. The mechanism for the disintegration of emulsions by anionic and nonionic surfactants appears to be different, but the ultimate dependence on HLB number appears to be similar. RP UNIV CALIF LOS ALAMOS SCI LAB, DIV MAT SCI & TECHNOL, LOS ALAMOS, NM 87545 USA. NR 16 TC 115 Z9 117 U1 2 U2 35 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 0743-7463 J9 LANGMUIR JI Langmuir PD JUL PY 1991 VL 7 IS 7 BP 1370 EP 1377 DI 10.1021/la00055a014 PG 8 WC Chemistry, Multidisciplinary; Chemistry, Physical; Materials Science, Multidisciplinary SC Chemistry; Materials Science GA FX350 UT WOS:A1991FX35000014 ER PT J AU ARMES, SP ALDISSI, M HAWLEY, M BEERY, JG GOTTESFELD, S AF ARMES, SP ALDISSI, M HAWLEY, M BEERY, JG GOTTESFELD, S TI MORPHOLOGY AND STRUCTURE OF CONDUCTING POLYMERS SO LANGMUIR LA English DT Article ID POLYPYRROLE PARTICLES; COLLOIDAL DISPERSIONS; EMERALDINE POLYMER; COMPOSITE FILMS; POLYANILINE; STABILIZERS; TRANSITION; TRANSPORT; SYSTEM AB We have examined polyaniline and polypyrrole colloids, polyaniline- and polypyrrole-coated textile substrates, and electrochemically synthesized polyaniline films by a combination of transmission and scanning electron microscopy, scanning tunneling microscopy, and energy-dispersive analytical X-rays. Our results shed new light on various aspects of these systems, including conduction mechanisms, coating homogeneity, and nanomorphology. C1 UNIV CALIF LOS ALAMOS SCI LAB,DIV MAT SCI & TECHNOL,LOS ALAMOS,NM 87545. UNIV CALIF LOS ALAMOS SCI LAB,ELECTR RES GRP,LOS ALAMOS,NM 87545. RP ARMES, SP (reprint author), UNIV SUSSEX,SCH CHEM,BRIGHTON BN1 9QJ,E SUSSEX,ENGLAND. OI Armes, Steven/0000-0002-8289-6351 NR 39 TC 86 Z9 87 U1 0 U2 7 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 SN 0743-7463 J9 LANGMUIR JI Langmuir PD JUL PY 1991 VL 7 IS 7 BP 1447 EP 1452 DI 10.1021/la00055a027 PG 6 WC Chemistry, Multidisciplinary; Chemistry, Physical; Materials Science, Multidisciplinary SC Chemistry; Materials Science GA FX350 UT WOS:A1991FX35000027 ER PT J AU SEGEV, A FANG, WP AF SEGEV, A FANG, WP TI OPTIMAL UPDATE POLICIES FOR DISTRIBUTED MATERIALIZED VIEWS SO MANAGEMENT SCIENCE LA English DT Article DE DATABASE; DATABASE VIEWS; MATERIALIZED VIEWS; DISTRIBUTED DATABASES; INFORMATION ID DATABASES AB In this paper we present an analysis of the problem of determining optimal policies for updating distributed materialized views. We demonstrate the general application of materialized views, and define the concept of materialized view currency and allow a query to specify its currency requirement. We also allow a materialized view to be updated from either a base relation or another materialized view. This flexibility provides an opportunity for further reduction in the cost of maintaining distributed materialized views. We model the problem of optimal update policies to capture currency and policy constraints, replicated data, and various view update policies. The optimization incorporates a minimum-cost objective function as well as user's response time constraints. C1 UNIV CALIF BERKELEY LAWRENCE BERKELEY LAB,DIV INFORMAT & COMP SCI,BERKELEY,CA 94720. UNIV CALIF BERKELEY,AGR RES & EXTENS RES DEPT,BERKELEY,CA 94720. RP SEGEV, A (reprint author), UNIV CALIF BERKELEY,WALTER A HAAS SCH BUSINESS,INFORMAT SYST PROGRAM,BERKELEY,CA 94720, USA. NR 24 TC 13 Z9 13 U1 0 U2 4 PU INST OPERATIONS RESEARCH MANAGEMENT SCIENCES PI LINTHICUM HTS PA 901 ELKRIDGE LANDING RD, STE 400, LINTHICUM HTS, MD 21090-2909 SN 0025-1909 J9 MANAGE SCI JI Manage. Sci. PD JUL PY 1991 VL 37 IS 7 BP 851 EP 870 DI 10.1287/mnsc.37.7.851 PG 20 WC Management; Operations Research & Management Science SC Business & Economics; Operations Research & Management Science GA GD933 UT WOS:A1991GD93300007 ER PT J AU NAUS, DJ OLAND, CB ARNDT, EG AF NAUS, DJ OLAND, CB ARNDT, EG TI AGING MANAGEMENT OF SAFETY-RELATED CONCRETE STRUCTURES TO PROVIDE IMPROVED BASES FOR CONTINUING THE SERVICE OF NUCLEAR-POWER-PLANTS SO MATERIALS AND STRUCTURES LA English DT Article C1 US NUCL REGULATORY COMMISS,WASHINGTON,DC 20555. RP NAUS, DJ (reprint author), OAK RIDGE NATL LAB,OAK RIDGE,TN 37831, USA. NR 29 TC 0 Z9 0 U1 1 U2 3 PU R I L E M PI CACHAN PA PAVILLON DES JARDINS, 61 AV DU PRESIDENT WILSON, 94235 CACHAN, FRANCE SN 0025-5432 J9 MATER STRUCT JI Mater. Struct. PD JUL PY 1991 VL 24 IS 142 BP 308 EP 316 DI 10.1007/BF02472087 PG 9 WC Construction & Building Technology; Engineering, Civil; Materials Science, Multidisciplinary SC Construction & Building Technology; Engineering; Materials Science GA JB013 UT WOS:A1991JB01300010 ER PT J AU LAIRD, G BROWN, RR NIELSEN, RL AF LAIRD, G BROWN, RR NIELSEN, RL TI FACTORS AFFECTING EUTECTIC SOLIDIFICATION OF CR-NI (-SI-MN) WHITE CAST IRONS SO MATERIALS SCIENCE AND TECHNOLOGY LA English DT Article ID AUSTENITE AB The crystal structure and morphology of eutectic carbides are known to strongly determine the mechanical and tribological properties of Cr-Ni white cast irons. In an effect to improve these properties, investigators at the US Bureau of Mines have studied the effects of alloying additions of 0.0-1.8%Si, 0.0-6.7%Ni, and 0.0-3.2%Mn (all wt-%) and solidification rates of from 1.0 to approximately 500 K min-1 on hypoeutectic irons containing approximately 3% C and approximately 8% Cr. The structure and morphology of the eutectic carbides formed were identified using electron microprobe analysis, X-ray diffraction, and scanning electron and optical microscopy. Differential thermal analysis was used to study the effects of alloying additions on the solidification reactions. The results show that these irons can have carbide structures consisting of (Fe, Cr)3Cr or (Fe, Cr)7C3 or both. These observations are explained in terms of the effects of Si, Ni, and Mn on the liquidus surface of the metastable Fe-Cr-C phase diagram. C1 OREGON STATE UNIV,COLL OCEANOG,CORVALLIS,OR 97331. RP LAIRD, G (reprint author), US BUR MINES,ALBANY RES CTR,ALBANY,OR, USA. NR 28 TC 4 Z9 4 U1 0 U2 4 PU INST MATERIALS PI LONDON PA 1 CARLTON HOUSE TERRACE, LONDON, ENGLAND SW1Y 5DB SN 0267-0836 J9 MATER SCI TECH SER JI Mater. Sci. Technol. PD JUL PY 1991 VL 7 IS 7 BP 631 EP 642 PG 12 WC Materials Science, Multidisciplinary; Metallurgy & Metallurgical Engineering SC Materials Science; Metallurgy & Metallurgical Engineering GA FZ921 UT WOS:A1991FZ92100009 ER PT J AU BRAMBLE, JH PASCIAK, JE WANG, JP XU, JC AF BRAMBLE, JH PASCIAK, JE WANG, JP XU, JC TI CONVERGENCE-ESTIMATES FOR PRODUCT ITERATIVE METHODS WITH APPLICATIONS TO DOMAIN DECOMPOSITION SO MATHEMATICS OF COMPUTATION LA English DT Article DE 2ND-ORDER ELLIPTIC EQUATION; DOMAIN DECOMPOSITION ID ELLIPTIC PROBLEMS; PRECONDITIONERS; CONSTRUCTION AB In this paper, we consider iterative methods for the solution of symmetric positive definite problems on a space V which are defined in terms of products of operators defined with respect to a number of subspaces. The simplest algorithm of this sort has an error-reducing operator which is the product of orthogonal projections onto the complement of the subspaces. New norm-reduction estimates for these iterative techniques will be presented in an abstract setting. Applications are given for overlapping Schwarz algorithms with many subregions for finite element approximation of second-order elliptic problems. C1 BROOKHAVEN NATL LAB,DEPT APPL SCI,UPTON,NY 11973. UNIV WYOMING,DEPT MATH,LARAMIE,WY 82071. PENN STATE UNIV,DEPT MATH,UNIVERSITY PK,PA 16802. RP BRAMBLE, JH (reprint author), CORNELL UNIV,DEPT MATH,ITHACA,NY 14853, USA. NR 20 TC 140 Z9 142 U1 0 U2 0 PU AMER MATHEMATICAL SOC PI PROVIDENCE PA 201 CHARLES ST, PROVIDENCE, RI 02940-2213 SN 0025-5718 J9 MATH COMPUT JI Math. Comput. PD JUL PY 1991 VL 57 IS 195 BP 1 EP 21 PG 21 WC Mathematics, Applied SC Mathematics GA FZ449 UT WOS:A1991FZ44900001 ER EF