FN Thomson Reuters Web of Science™ VR 1.0 PT J AU DRAKE, DM WENDER, SA NELSON, RO CLARK, DA DROSG, M AMIAN, W BRUCKNER, J ENGLERT, PAJ AF DRAKE, DM WENDER, SA NELSON, RO CLARK, DA DROSG, M AMIAN, W BRUCKNER, J ENGLERT, PAJ TI EXPERIMENTAL SIMULATION OF MARTIAN NEUTRON LEAKAGE SPECTRA SO NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH SECTION A-ACCELERATORS SPECTROMETERS DETECTORS AND ASSOCIATED EQUIPMENT LA English DT Article AB The LAMPF 800 MeV proton beam and a container of sand, mixed to resemble martian soil, were used to simulate the neutron leakage spectrum of Mars. The neutron spectra were measured by time-of-flight techniques and compared with Monte Carlo calculations. C1 UNIV VIENNA, A-1010 VIENNA, AUSTRIA. FORSCHUNGSZENTRUM JULICH, W-5170 JULICH 1, GERMANY. MAX PLANCK INST CHEM, W-6500 MAINZ, GERMANY. SAN JOSE STATE UNIV, SAN JOSE, CA 95192 USA. RP DRAKE, DM (reprint author), UNIV CALIF LOS ALAMOS SCI LAB, LOS ALAMOS, NM 87544 USA. NR 14 TC 3 Z9 3 U1 0 U2 0 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0168-9002 J9 NUCL INSTRUM METH A JI Nucl. Instrum. Methods Phys. Res. Sect. A-Accel. Spectrom. Dect. Assoc. Equip. PD NOV 15 PY 1991 VL 309 IS 3 BP 575 EP 580 DI 10.1016/0168-9002(91)90265-R PG 6 WC Instruments & Instrumentation; Nuclear Science & Technology; Physics, Nuclear; Physics, Particles & Fields SC Instruments & Instrumentation; Nuclear Science & Technology; Physics GA GT824 UT WOS:A1991GT82400027 ER PT J AU DEUTSCH, IH GARRISON, JC AF DEUTSCH, IH GARRISON, JC TI QUANTUM SPATIAL PROPAGATION OF SQUEEZED LIGHT IN A DEGENERATE PARAMETRIC-AMPLIFIER SO OPTICS COMMUNICATIONS LA English DT Article ID STATES; FIELD AB Differential equations which describe the steady state spatial evolution of nonclassical light are established using standard quantum field theoretic techniques. A Schrodinger equation for the state vector of the optical field is derived using the quantum analog of the slowly varying envelope approximation (SVEA). The steady state solutions are those that satisfy the time independent Schrodinger equation. The resulting eigenvalue problem then leads to the spatial propagation equations. For the degenerate parametric amplifier this method shows that the squeezed state is an eigenstate of the squeezing hamiltonian. The magnitude and phase of the squeezing parameter obey nonlinear differential equations coupled by the amplifier gain constant and phase mismatch. The solution to these differential equations is equivalent to one obtained from the classical three-wave mixing steady state solution to the parametric amplifier with a nondepleted pump. C1 UNIV CALIF LAWRENCE LIVERMORE NATL LAB,LIVERMORE,CA 94550. RP DEUTSCH, IH (reprint author), UNIV CALIF BERKELEY,DEPT PHYS,BERKELEY,CA 94720, USA. RI Deutsch, Ivan/D-1882-2009 OI Deutsch, Ivan/0000-0002-1733-5750 NR 19 TC 7 Z9 7 U1 0 U2 0 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0030-4018 J9 OPT COMMUN JI Opt. Commun. PD NOV 15 PY 1991 VL 86 IS 3-4 BP 311 EP 316 DI 10.1016/0030-4018(91)90011-2 PG 6 WC Optics SC Optics GA GT570 UT WOS:A1991GT57000011 ER PT J AU JACOBSEN, C WILLIAMS, S ANDERSON, E BROWNE, MT BUCKLEY, CJ KERN, D KIRZ, J RIVERS, M ZHANG, X AF JACOBSEN, C WILLIAMS, S ANDERSON, E BROWNE, MT BUCKLEY, CJ KERN, D KIRZ, J RIVERS, M ZHANG, X TI DIFFRACTION-LIMITED IMAGING IN A SCANNING-TRANSMISSION X-RAY MICROSCOPE SO OPTICS COMMUNICATIONS LA English DT Article ID BIOLOGICAL-MATERIALS; ZONE PLATES; RESOLUTION AB We report the characterization of a scanning transmission X-ray microscope which makes use of an undulator X-ray source, a high resolution scanning stage, and a 45 nm outer zone width, > 10% diffraction efficiency Fresnel zone plate as the probe-forming optic at soft X-ray wavelengths (typically 3.64 nm). The modulation transfer function of the instrument is in good agreement with theory; it remains above 0.1 to spatial frequencies corresponding to structures as small as 25 nm. This spatial frequency limit is the best obtained in any soft X-ray microscope, and is about a factor of ten better than what is attained in conventional or confocal visible light microscopes. By deconvolving the zone plate point spread function from the image, the microscope has been used to resolve 36 nm features in a gold test object. The microscope is used primarily for the study of thick, hydrated biological specimens with minimal radiation dose. C1 UNIV CALIF BERKELEY,LAWRENCE BERKELEY LAB,CTR XRAY OPT,BERKELEY,CA 94720. UNIV LONDON KINGS COLL,DEPT PHYS,LONDON WC2R 2LS,ENGLAND. IBM CORP,THOMAS J WATSON RES CTR,NANOLITHOG GRP,YORKTOWN HTS,NY 10598. UNIV CHICAGO,DEPT GEOPHYS SCI,CHICAGO,IL 60637. RP JACOBSEN, C (reprint author), SUNY STONY BROOK,DEPT PHYS,STONY BROOK,NY 11794, USA. RI Jacobsen, Chris/E-2827-2015 OI Jacobsen, Chris/0000-0001-8562-0353 NR 46 TC 177 Z9 177 U1 1 U2 20 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0030-4018 J9 OPT COMMUN JI Opt. Commun. PD NOV 15 PY 1991 VL 86 IS 3-4 BP 351 EP 364 DI 10.1016/0030-4018(91)90016-7 PG 14 WC Optics SC Optics GA GT570 UT WOS:A1991GT57000016 ER PT J AU YOUNG, DA COREY, EM DEWITT, HE AF YOUNG, DA COREY, EM DEWITT, HE TI ANALYTIC FIT TO THE ONE-COMPONENT-PLASMA STRUCTURE FACTOR SO PHYSICAL REVIEW A LA English DT Article ID CLASSICAL PLASMA; STATE; THERMODYNAMICS; APPROXIMATION; EQUATION; FLUIDS; FORM AB We use a nonlinear least-squares-fitting program to find an analytic fit to the one-component plasma fluid structure factor S(q,GAMMA) over the ranges 0 less-than-or-equal-to q less-than-or-equal-to 21.75 and 1 less-than-or-equal-to GAMMA less-than-or-equal-to 225. The S(q,GAMMA) function is generated as a table from the solution of the modified hypernetted chain integral equation. The table is fitted with polynomials in q and GAMMA, using a total of 175 coefficients. The overall fit is good, suggesting that the fitting method might be applied successfully to other distribution functions. RP YOUNG, DA (reprint author), UNIV CALIF LAWRENCE LIVERMORE NATL LAB,LIVERMORE,CA 94550, USA. NR 18 TC 25 Z9 25 U1 0 U2 1 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 1050-2947 J9 PHYS REV A JI Phys. Rev. A PD NOV 15 PY 1991 VL 44 IS 10 BP 6508 EP 6512 DI 10.1103/PhysRevA.44.6508 PG 5 WC Optics; Physics, Atomic, Molecular & Chemical SC Optics; Physics GA GR738 UT WOS:A1991GR73800040 ER PT J AU BACK, CA CHENAISPOPOVICS, C LEE, RW AF BACK, CA CHENAISPOPOVICS, C LEE, RW TI PHOTOPUMPING AND FLUORESCENCE IN A LASER-PRODUCED PLASMA .1. EXPERIMENTAL RESULTS SO PHYSICAL REVIEW A LA English DT Article ID X-RAY LASERS; ABSORPTION-SPECTROSCOPY; SPECTRA; IONS AB A complete series of three experiments dedicated to the study of a photopumping and resonance fluorescence scheme is presented. An aluminum plasma is preformed in the heliumlike ground state by a 2-J 1.06-mu-m laser beam, then this plasma is photopumped by an x-ray source approximately 1 ns later. The pump is a spatially distinct laser-produced plasma that emits intense emission of the heliumlike resonance lines in the 4-8-angstrom region. The pump is line coincident with the transitions to be photopumped. The resulting perturbation is studied by the fluorescence, which is directly observed and absolutely quantified. The separate characterization of each component of this system is discussed in detail, with an emphasis on the experimental quantities that will be compared with numerical calculations. C1 UNIV CALIF LAWRENCE LIVERMORE NATL LAB,LIVERMORE,CA 94550. RP BACK, CA (reprint author), ECOLE POLYTECH,PHYS MILIEUX IONISES LAB,F-91128 PALAISEAU,FRANCE. NR 28 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 1050-2947 J9 PHYS REV A JI Phys. Rev. A PD NOV 15 PY 1991 VL 44 IS 10 BP 6730 EP 6742 DI 10.1103/PhysRevA.44.6730 PG 13 WC Optics; Physics, Atomic, Molecular & Chemical SC Optics; Physics GA GR738 UT WOS:A1991GR73800061 ER PT J AU BACK, CA CASTOR, JI KLEIN, RI DYKEMA, PG LEE, RW AF BACK, CA CASTOR, JI KLEIN, RI DYKEMA, PG LEE, RW TI PHOTOPUMPING AND FLUORESCENCE IN A LASER-PRODUCED PLASMA .2. SIMULATIONS SO PHYSICAL REVIEW A LA English DT Article ID RADIATION; SPECTRA AB Detailed radiative-transfer simulations are presented for plasma that is prepared in a predominantly heliumlike ground state and then photopumped. The plasma conditions in the simulation are based on those determined in a line-coincidence experiment described in the preceding paper [C. A. Back, C. Chenais-Popovics, and R. W. Lee, Phys. Rev. A 44, 6730 (1991)]. The measured emitted flux of the resonance line of the heliumlike aluminum ion, at 7.757 angstrom, is used as input for the photon pump. Predictions of the fluorescence are directly compared with experimental results. The synthetic spectra are calculated, and the effect of the photopumping on the level populations and ionization balance is discussed. Also a description is included of the equivalent two-level-atom radiative-transfer scheme that is used to calculate the self-consistent solution of the level populations and the radiation field. C1 UNIV CALIF LAWRENCE LIVERMORE NATL LAB,LIVERMORE,CA 94550. UNIV CALIF BERKELEY,DEPT ASTRON,BERKELEY,CA 94720. RP BACK, CA (reprint author), ECOLE POLYTECH,PHYS MILIEUX IONISES LAB,F-91128 PALAISEAU,FRANCE. NR 19 TC 9 Z9 9 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 NOV 15 PY 1991 VL 44 IS 10 BP 6743 EP 6761 DI 10.1103/PhysRevA.44.6743 PG 19 WC Optics; Physics, Atomic, Molecular & Chemical SC Optics; Physics GA GR738 UT WOS:A1991GR73800062 ER PT J AU ROZSNYAI, BF BLOOM, SD RESLER, DA AF ROZSNYAI, BF BLOOM, SD RESLER, DA TI COMPUTATION OF SPECTRAL ARRAYS IN HOT PLASMAS USING THE LANCZOS-ALGORITHM SO PHYSICAL REVIEW A LA English DT Article ID TRANSITION ARRAYS; ATOMIC SPECTRA; DENSITY; MATTER AB We apply the approach initiated by Lanczos to compute large spectral arrays in hot plasmas. The wave functions that form the basis for the Lanczos state vectors are derived from a self-consistent "average-atom" model. We present calculations for a bromine plasma at low and at metallic density. RP ROZSNYAI, BF (reprint author), UNIV CALIF LAWRENCE LIVERMORE NATL LAB,DEPT PHYS,POB 808,LIVERMORE,CA 94550, USA. NR 19 TC 8 Z9 8 U1 0 U2 1 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 1050-2947 J9 PHYS REV A JI Phys. Rev. A PD NOV 15 PY 1991 VL 44 IS 10 BP 6791 EP 6799 DI 10.1103/PhysRevA.44.6791 PG 9 WC Optics; Physics, Atomic, Molecular & Chemical SC Optics; Physics GA GR738 UT WOS:A1991GR73800066 ER PT J AU FERRARIO, M CICCOTTI, G HOLIAN, BL RYCKAERT, JP AF FERRARIO, M CICCOTTI, G HOLIAN, BL RYCKAERT, JP TI SHEAR-RATE DEPENDENCE OF THE VISCOSITY OF THE LENNARD-JONES LIQUID AT THE TRIPLE POINT SO PHYSICAL REVIEW A LA English DT Note ID MOLECULAR-DYNAMICS METHOD; MODE-COUPLING THEORY; SIMPLE FLUIDS; CANONICAL ENSEMBLE; GREEN-KUBO AB High-precision molecular-dynamics (MD) data are reported for the shear viscosity eta of the Lennard-Jones liquid at its triple point, as a function of the shear rate epsilon for a large system (N = 2048). The Green-Kubo (GK) value eta(epsilon = 0) = 3.24 +/- 0.04 is estimated from a run of 3.6 x 10(6) steps (40 nsec). We find no numerical evidence of a t-3/2 long-time tail for the GK integrand (stress-stress time-correlation function). From our nonequilibrium MD results, obtained both at small and large values of epsilon, a consistent picture emerges that supports an analytical (quadratic at low shear rate) dependence of the viscosity on epsilon. C1 UNIV MESSINA,IST FIS TEOR,I-98166 ST AGATA MILITELL,ITALY. UNIV CALIF LOS ALAMOS SCI LAB,LOS ALAMOS,NM 87545. UNIV LIBRE BRUXELLES,POOL PHYS,B-1050 BRUSSELS,BELGIUM. UNIV ROME LA SAPIENZA,DIPARTMENTO FIS,I-00185 ROME,ITALY. RI Ferrario, Mauro/B-8461-2008 OI Ferrario, Mauro/0000-0001-6754-9055 NR 17 TC 32 Z9 32 U1 4 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 NOV 15 PY 1991 VL 44 IS 10 BP 6936 EP 6939 DI 10.1103/PhysRevA.44.6936 PG 4 WC Optics; Physics, Atomic, Molecular & Chemical SC Optics; Physics GA GR738 UT WOS:A1991GR73800086 ER PT J AU LI, Y KRIEGER, JB NORMAN, MR IAFRATE, GJ AF LI, Y KRIEGER, JB NORMAN, MR IAFRATE, GJ TI BAND-STRUCTURE CALCULATIONS OF NOBLE-GAS AND ALKALI-HALIDE SOLIDS USING ACCURATE KOHN-SHAM POTENTIALS WITH SELF-INTERACTION CORRECTION SO PHYSICAL REVIEW B LA English DT Article ID DENSITY-FUNCTIONAL THEORY; DERIVATIVE DISCONTINUITIES; ELECTRONIC-STRUCTURE; ENERGY-BANDS; PHOTOEMISSION; EXCHANGE; LICL; NACL AB The optimized-effective-potential (OEP) method and a method developed recently by Krieger, Li, and Iafrate (KLI) are applied to the band-structure calculations of noble-gas and alkali halide solids employing the self-interaction-corrected (SIC) local-spin-density (LSD) approximation for the exchange-correlation energy functional. The resulting band gaps from both calculations are found to be in fair agreement with the experimental values. The discrepancies are typically within a few percent with results that are nearly the same as those of previously published orbital-dependent multipotential SIC calculations, whereas the LSD results underestimate the band gaps by as much as 40%. As in the LSD- and it is believed to be the case even for the exact Kohn-Sham potential-both the OEP and KLI predict valence-band widths which are narrower than those of experiment. In all cases, the KLI method yields essentially the same results as the OEP. C1 ARGONNE NATL LAB, DIV MAT SCI, ARGONNE, IL 60439 USA. USA, RES OFF, RES TRIANGLE PK, NC 27709 USA. RP CUNY BROOKLYN COLL, DEPT PHYS, BROOKLYN, NY 11210 USA. RI Norman, Michael/C-3644-2013 NR 37 TC 52 Z9 52 U1 0 U2 3 PU AMER PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 2469-9950 EI 2469-9969 J9 PHYS REV B JI Phys. Rev. B PD NOV 15 PY 1991 VL 44 IS 19 BP 10437 EP 10443 DI 10.1103/PhysRevB.44.10437 PG 7 WC Physics, Condensed Matter SC Physics GA GP689 UT WOS:A1991GP68900001 ER PT J AU GIESEKUS, A FALICOV, LM AF GIESEKUS, A FALICOV, LM TI THEORY OF PRESSURE-INDUCED MAGNETIC AND METAL-INSULATOR TRANSITIONS SO PHYSICAL REVIEW B LA English DT Article ID INTERSECTING-SPHERES MODEL; NICL2 AB A theory of pressure-induced simultaneous metal-insulator and magnetic phase transitions is presented. It is based on a model consisting of a periodic lattice with (1) an itinerant-electron band, (2) a narrow dispersionless band (localized states), (3) a hybridization term, (4) a very strong short-ranged repulsion between electrons of opposite spin in the localized states, and (5) a moderately strong short-ranged repulsion between electrons in the itinerant and localized bands. The problem is treated in the Hartree-Fock approximation, allowing spontaneous ferromagnetic broken symmetry. Pressure, which mainly changes the energy separation between the two bands, induces transitions from insulating, (ferro)magnetic states, to metallic states with no localized moments. The transition may be continuous or discontinuous, depending on the values of the interaction parameters. A richly structured phase diagram is obtained. For some values of the parameters the model reproduces in a reasonable fashion and for T --> 0 the complex transition recently found in NiI2 at pressures of about 19 GPa. C1 UNIV CALIF BERKELEY,LAWRENCE BERKELEY LAB,DIV MAT SCI,BERKELEY,CA 94720. UNIV DORTMUND,INST PHYS,POSTFACH 500500,W-4600 DORTMUND 50,GERMANY. RP GIESEKUS, A (reprint author), UNIV CALIF BERKELEY,DEPT PHYS,BERKELEY,CA 94720, USA. NR 19 TC 9 Z9 9 U1 0 U2 3 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 0163-1829 J9 PHYS REV B JI Phys. Rev. B PD NOV 15 PY 1991 VL 44 IS 19 BP 10449 EP 10454 DI 10.1103/PhysRevB.44.10449 PG 6 WC Physics, Condensed Matter SC Physics GA GP689 UT WOS:A1991GP68900003 ER PT J AU LU, ZW WEI, SH ZUNGER, A AF LU, ZW WEI, SH ZUNGER, A TI ELECTRONIC-STRUCTURE OF RANDOM AG0.5PD0.5-ALLOYS AND AG0.5AU0.5-ALLOYS SO PHYSICAL REVIEW B LA English DT Article ID ABSORPTION FINE-STRUCTURE; COHERENT-POTENTIAL-APPROXIMATION; SPECIAL-QUASIRANDOM-STRUCTURES; RANDOM SOLID-SOLUTIONS; SITE DIAGONAL DISORDER; GROUND-STATE; SUBSTITUTIONAL ALLOYS; PHASE-STABILITY; AGCPD1-C ALLOYS; LOCAL-STRUCTURE AB The electronic density of states and mixing enthalpies of random substitutional A1-xBx alloys have often been described within the single-site coherent-potential approximation (SCPA). There one assumes that each atom interacts with a fictitious, highly symmetric average medium and that at a given composition x, all A atoms (and separately, all B atoms) are equivalent (i.e., have the same charges and atomic sizes). In reality, however, a random alloy manifests a distribution of different (generally, low-symmetry) local environments, whereby an atom surrounded locally mostly by like atoms can have different charge-transfer or structural relaxations than an atom surrounded mostly by unlike atoms. Such "environmental effects" (averaged out in the SCPA) were previously studied in terms of simple model Hamiltonians. We offer here an efficient method capable of describing such effects within first-principles self-consistent electronic-structure theory. This is accomplished through the use of the "special-quasirandom-structures" (SQS) concept [Zunger et al., Phys. Rev. Lett. 65, 353 (1990)], whereby the lattice sites of a periodic "supercell" are occupied by A's and B's in such a way that the structural correlation functions closely mimic those of a perfectly random infinite alloy. The self-consistent charge density, total and local density of states, and mixing enthalpies are then obtained by applying band theory (here, the linearized augmented-plane-wave method) to the SQS. Application to Ag0.5Pd0.5 and Ag0.5Au0.5 alloys clearly reveals environmental effects; that is, the charge distribution and local density of states of a given atomic site depend sensitively not only on the composition and occupation of the site but also on the distribution of atoms around it. This SQS approach provides a rather general framework for studying the electronic density of states of alloys. RP SOLAR ENERGY RES INST, GOLDEN, CO 80401 USA. RI Zunger, Alex/A-6733-2013 NR 100 TC 66 Z9 66 U1 0 U2 10 PU AMER PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 2469-9950 EI 2469-9969 J9 PHYS REV B JI Phys. Rev. B PD NOV 15 PY 1991 VL 44 IS 19 BP 10470 EP 10484 DI 10.1103/PhysRevB.44.10470 PG 15 WC Physics, Condensed Matter SC Physics GA GP689 UT WOS:A1991GP68900006 ER PT J AU SWANSON, LS LANE, PA SHINAR, J WUDL, F AF SWANSON, LS LANE, PA SHINAR, J WUDL, F TI POLARONS AND TRIPLET POLARONIC EXCITONS IN POLY(PARAPHENYLENEVINYLENE) (PPV) AND SUBSTITUTED PPV - AN OPTICALLY DETECTED MAGNETIC-RESONANCE STUDY SO PHYSICAL REVIEW B LA English DT Article ID CONJUGATED POLYMERS; LUMINESCENCE; SPECTRA; SOLIDS AB The X-band optically detected magnetic resonance (ODMR) of poly(paraphenylenevinylene) (PPV) and its dihexoxy derivative films and solutions is described and discussed. As in poly(3-alkylthiophenes) (P3AT), the photoluminescence (PL) -enhancing features include a narrow resonance at g approximately equal to 2.0023, a broad triplet powder pattern around g approximately 2, and the DELTA-m(S) = 2 transition of this triplet at g approximately equal to 4.07. The symmetric narrow resonance, attributed to intrachain "distant" polaron recombination, indicates that charge-conjugation symmetry violation is weaker in PPV than in P3AT. As in P3AT, its spectral dependence is similar to the PL spectrum, suggesting that the polaron levels are close to the band edges. Although the spectral dependence of the half-field resonance is similar, that may result from singlets generated by triplet-triplet collisions. A broad decrease in the ODMR intensity at g approximately 2, probably due to a PL-quenching resonance resulting from geminate singlet decay, is also observed at low temperatures. C1 IOWA STATE UNIV SCI & TECHNOL,DEPT PHYS,AMES,IA 50011. UNIV CALIF SANTA BARBARA,INST POLYMERS & ORGAN SOLIDS,SANTA BARBARA,CA 93106. UNIV CALIF SANTA BARBARA,DEPT PHYS,SANTA BARBARA,CA 93106. RP SWANSON, LS (reprint author), IOWA STATE UNIV SCI & TECHNOL,AMES LAB,AMES,IA 50011, USA. NR 21 TC 112 Z9 112 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 NOV 15 PY 1991 VL 44 IS 19 BP 10617 EP 10621 DI 10.1103/PhysRevB.44.10617 PG 5 WC Physics, Condensed Matter SC Physics GA GP689 UT WOS:A1991GP68900023 ER PT J AU KONG, Y LYNN, KG AF KONG, Y LYNN, KG TI TRAPPING OF THERMAL POSITRONS AT METAL-SURFACES SO PHYSICAL REVIEW B LA English DT Article ID VACANCY CLUSTERS AB The interaction of positrons with a surface potential is considered as a two-step process, upon which the time-dependent positron trapping into the surface potential is evaluated. The reflection of positrons at the surface potential is seen to be larger than previously calculated. This suggests that the interaction of positrons with a surface is a many-encounter process. RP KONG, Y (reprint author), BROOKHAVEN NATL LAB,DEPT PHYS,UPTON,NY 11973, USA. NR 10 TC 1 Z9 1 U1 0 U2 0 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 0163-1829 J9 PHYS REV B JI Phys. Rev. B PD NOV 15 PY 1991 VL 44 IS 19 BP 10843 EP 10847 DI 10.1103/PhysRevB.44.10843 PG 5 WC Physics, Condensed Matter SC Physics GA GP689 UT WOS:A1991GP68900047 ER PT J AU TIDSWELL, IM RABEDEAU, TA PERSHAN, PS FOLKERS, JP BAKER, MV WHITESIDES, GM AF TIDSWELL, IM RABEDEAU, TA PERSHAN, PS FOLKERS, JP BAKER, MV WHITESIDES, GM TI WETTING FILMS ON CHEMICALLY MODIFIED SURFACES - AN X-RAY STUDY SO PHYSICAL REVIEW B LA English DT Article ID SELF-ASSEMBLED MONOLAYERS; MULTILAYER ADSORPTION; ARGON FILMS; SILICON; ALKYLSILOXANES; REFLECTIVITY; CHEMISTRY; FORCES AB The wetting of silicon wafers and silicon wafers coated with alkylsiloxane monolayers by saturated vapors of cyclohexane and methanol were studied using x-ray specular reflection. Differentially heating the substrate surface relative to the temperature of a liquid reservoir was used to probe the disjoining pressure as a function of the film thickness and surface chemistry. Uncoated silicon wafers wet completely. The variations in film thickness with DELTA-T are explained exclusively in terms of the nonretarded van der Waals forces for films 10-120 angstrom thick. Wafers coated with methyl terminated alkylsiloxane monolayers wet incompletely, with a microscopic film 1-3 angstrom thick adsorbing on the surface. Changing the alkylsiloxane terminal group from -CH3 to -CH2OH converts the surface from incompletely to completely wet. Surfaces coated with partial monolayers of methyl terminated alkylsiloxane of greater than 50% coverage are incompletely wet by cyclohexane, with the monolayers "swelling" to a thickness close to that of fully extended alkane chains through incorporation of cyclohexane into the film structure. The data are consistent with a first-order transition to complete wetting upon reduction of the alkylsiloxane coverage below approximately 50%. The importance of the surface atomic layer in the promotion or suppression of complete wetting is explained in the context of van der Waals forces. C1 UNIV CALIF BERKELEY,LAWRENCE BERKELEY LAB,DIV APPL SCI,BERKELEY,CA 94720. HARVARD UNIV,DEPT CHEM,CAMBRIDGE,MA 02138. RI Baker, Murray/B-4539-2013 NR 48 TC 45 Z9 45 U1 1 U2 10 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 0163-1829 J9 PHYS REV B JI Phys. Rev. B PD NOV 15 PY 1991 VL 44 IS 19 BP 10869 EP 10879 DI 10.1103/PhysRevB.44.10869 PG 11 WC Physics, Condensed Matter SC Physics GA GP689 UT WOS:A1991GP68900050 ER PT J AU WALUKIEWICZ, W HOPKINS, PF SUNDARAM, M GOSSARD, AC AF WALUKIEWICZ, W HOPKINS, PF SUNDARAM, M GOSSARD, AC TI SIZE EFFECT IN PARABOLIC GAAS/ALXGA1-XAS QUANTUM-WELLS SO PHYSICAL REVIEW B LA English DT Note ID DEFORMATION POTENTIALS; ELECTRON-GAS; SEMICONDUCTORS AB We report the results of experimental and theoretical studies of the electron mobility in remotely doped, quasi-three-dimensional GaAs/AlxGa1-xAs parabolic wells. We show that the electron mobility in such structures is strongly reduced by a size effect due to nonspecular scattering of electrons from rough walls confining the electron gas. The roughness of the walls results from random fluctuations of the remote-ionized-impurity concentration and/or the alloy composition. Incorporation of the size effect allows for a quantitative description of the electron mobility in these parabolic wells. C1 UNIV CALIF SANTA BARBARA,DEPT MAT ELECT & COMP ENGN,SANTA BARBARA,CA 93106. RP WALUKIEWICZ, W (reprint author), UNIV CALIF BERKELEY,LAWRENCE BERKELEY LAB,DIV MAT SCI,BERKELEY,CA 94720, USA. NR 20 TC 10 Z9 10 U1 0 U2 2 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 0163-1829 J9 PHYS REV B JI Phys. Rev. B PD NOV 15 PY 1991 VL 44 IS 19 BP 10909 EP 10912 DI 10.1103/PhysRevB.44.10909 PG 4 WC Physics, Condensed Matter SC Physics GA GP689 UT WOS:A1991GP68900059 ER PT J AU POWERS, JM WANDER, A ROUS, PJ VANHOVE, MA SOMORJAI, GA AF POWERS, JM WANDER, A ROUS, PJ VANHOVE, MA SOMORJAI, GA TI STRUCTURAL-ANALYSIS OF THE BETA-SIC(100)-C(2X2) SURFACE RECONSTRUCTION BY AUTOMATED TENSOR LOW-ENERGY ELECTRON-DIFFRACTION SO PHYSICAL REVIEW B LA English DT Article ID SILICON-CARBIDE SURFACES; SPECTROSCOPY; LEED; OXYGEN AB The atomic structure of the beta-SiC(100)-c(2 X 2) surface was analyzed using dynamical calculations of low-energy electron-diffraction intensities. The c(2 X 2) surface was prepared in ultrahigh vacuum by two different methods. The first utilized the removal of surface silicon by high-temperature annealing in ultrahigh vacuum. The second route utilized the deposition of surface carbon by exposing the stoichiometric (2 X 1) surface at 1125 K to C2H4. Our results showed that both methods produced a surface terminated with C2 groups in staggered silicon bridge sites. Weak silicon dimer bonds were found in the second atomic layer of the c(2 X 2) surface produced by silicon sublimation, but not for the c(2 X 2) surface produced by C2H4 exposure. We postulate that hydrogen, released by the thermal decomposition of C2H4, saturated silicon dangling bonds in the second atomic layer, suppressing dimer formation. C1 UNIV CALIF BERKELEY,LAWRENCE BERKELEY LAB,CTR ADV MAT,DIV MAT SCI,BERKELEY,CA 94720. UNIV CALIF BERKELEY,DEPT CHEM,BERKELEY,CA 94720. RI Van Hove, Michel/A-9862-2008 OI Van Hove, Michel/0000-0002-8898-6921 NR 19 TC 104 Z9 104 U1 1 U2 6 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 0163-1829 J9 PHYS REV B JI Phys. Rev. B PD NOV 15 PY 1991 VL 44 IS 20 BP 11159 EP 11166 DI 10.1103/PhysRevB.44.11159 PG 8 WC Physics, Condensed Matter SC Physics GA GR559 UT WOS:A1991GR55900018 ER PT J AU BERNARD, JE FROYEN, S ZUNGER, A AF BERNARD, JE FROYEN, S ZUNGER, A TI SPONTANEOUS SURFACE-INDUCED LONG-RANGE ORDER IN GA0.5IN0.5P ALLOYS SO PHYSICAL REVIEW B LA English DT Article ID VAPOR-PHASE EPITAXY; BAND-GAP ENERGY; SEMICONDUCTOR SOLID-SOLUTIONS; MOLECULAR-BEAM EPITAXY; X-RAY-DIFFRACTION; ALAS RANDOM ALLOY; TERNARY-III-V; 1ST-PRINCIPLES CALCULATION; MIXING ENTHALPY; ISOVALENT IMPURITIES AB Previous total-energy calculations for bulk Ga0.5In0.5P alloys have demonstrated that the lowest-energy configuration at T = 0 corresponds to phase separation into GaP + InP, followed by the ordered GaInP2 chalcopyrite phase as the next lowest state; the (111)-ordered CuPt-like superstructure is predicted to lie at a much higher energy. Yet, vapor-phase crystal growth has shown CuPt-like long-range ordering in relatively thick Ga0.5In0.5P films grown on a lattice-matched (001) GaAs substrate. We present here first-principles local-density total-energy calculations for Ga0.5In0.5P/GaAs(001) in various two-dimensional structures, each having a free surface. For one-monolayer coverage, we find electronically driven surface reconstructions, consisting not only of the previously known cation dimerization, but also of buckling and tilting of the surface dimers. These considerably stabilize the CuPt-like surface topology over all other forms of surface order, including phase separation. Furthermore, a Ga/In layer covered by three monolayers still exhibits a significant energy preference (relative to kT(g), where T(g) congruent-to 900 K is the growth temperature) for the CuPt structure. If complete atomic mobility were to exist irrespective of how deeply buried the atoms are, we would then expect that the surface-stable CuPt ordering would exist in the near-surface regions, whereas deeper layers would revert to the bulk-stable structures. Since, however, surface atomic mobilities are far larger than bulk mobilities, it is possible that surface-stabilized structures will be frozen in and consequently ordering will propagate into macroscopic film dimensions. In light of our results, we describe several possible ways that surface effects could lead to long-range CuPt-like ordering. RP BERNARD, JE (reprint author), SOLAR ENERGY RES INST,GOLDEN,CO 80401, USA. RI Zunger, Alex/A-6733-2013 NR 122 TC 60 Z9 60 U1 0 U2 4 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 0163-1829 J9 PHYS REV B JI Phys. Rev. B PD NOV 15 PY 1991 VL 44 IS 20 BP 11178 EP 11195 DI 10.1103/PhysRevB.44.11178 PG 18 WC Physics, Condensed Matter SC Physics GA GR559 UT WOS:A1991GR55900020 ER PT J AU CHEN, Y TONG, SY KIM, JS KESMODEL, LL RODACH, T BOHNEN, KP HO, KM AF CHEN, Y TONG, SY KIM, JS KESMODEL, LL RODACH, T BOHNEN, KP HO, KM TI CHARACTERIZATION OF SURFACE PHONONS ON CU(001) AND AG(001) - 1ST-PRINCIPLES PHONON CALCULATIONS WITH EXPERIMENTAL AND THEORETICAL-STUDIES OF HIGH-RESOLUTION ELECTRON-ENERGY-LOSS SPECTRA SO PHYSICAL REVIEW B LA English DT Article ID CROSS-SECTION ANALYSIS; EMBEDDED-ATOM METHOD; ADSORBATE VIBRATIONS; BULK PHONONS; SCATTERING; CU(100); DISPERSION; MODES AB A parameter-free first-principles phonon calculation is combined with a multiple-scattering electron-energy-loss-spectra calculation to characterize surface phonons of Cu(001) and Ag(001). The electron-energy-loss data on Cu(001) reveal the gap mode S6 at XBAR, which has been detected before only for Ni(001). The calculations also discover two additional surface modes on these surfaces, and the inelastic-electron-scattering cross sections of these modes are investigated. With the discovery of these modes, and knowledge about their inelastic-cross-section behavior, data of inelastic electron scattering are very satisfactorily explained. We also suggest that the mode found at XBAR could explain a recent He-atom scattering experiment. A comprehensive picture is established for the surface phonons on Cu(001) and Ag(001). C1 UNIV WISCONSIN,DEPT PHYS,MILWAUKEE,WI 53201. INDIANA UNIV,DEPT PHYS,BLOOMINGTON,IN 47405. KERNFORSCHUNGSZENTRUM KARLSRUHE GMBH,INST NUKL FESTKORPERPHYS,W-7500 KARLSRUHE 1,GERMANY. IOWA STATE UNIV SCI & TECHNOL,AMES LAB,AMES,IA 50011. IOWA STATE UNIV SCI & TECHNOL,DEPT PHYS,AMES,IA 50011. RP CHEN, Y (reprint author), UNIV WISCONSIN,SURFACE STUDIES LAB,MILWAUKEE,WI 53201, USA. NR 26 TC 42 Z9 42 U1 0 U2 3 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 0163-1829 J9 PHYS REV B JI Phys. Rev. B PD NOV 15 PY 1991 VL 44 IS 20 BP 11394 EP 11401 DI 10.1103/PhysRevB.44.11394 PG 8 WC Physics, Condensed Matter SC Physics GA GR559 UT WOS:A1991GR55900045 ER PT J AU QIAN, GX LEUNG, KM AF QIAN, GX LEUNG, KM TI PHOTONIC BAND-STRUCTURE - THE CASE OF OVAL HOLES SO PHYSICAL REVIEW B LA English DT Note ID PERIODIC DIELECTRIC STRUCTURES; WAVE-PROPAGATION AB The photonic bands of a face-centered-cubic structure with a basis consisting of three intersecting cylinders with oval cross section are computed using the plane-wave method. The optimal band-gap size to midgap frequency ratio is found to be 12% larger than the case of circular holes for a refractive-index contrast of 3.6. A contour plot is computed that gives this ratio as a function of both the refractive-index contrast and the major diameter of the oval holes. C1 POLYTECH UNIV,DEPT PHYS,NEW YORK,NY 11201. BROOKHAVEN NATL LAB,DEPT PHYS,UPTON,NY 11973. NR 13 TC 4 Z9 4 U1 0 U2 2 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 0163-1829 J9 PHYS REV B JI Phys. Rev. B PD NOV 15 PY 1991 VL 44 IS 20 BP 11482 EP 11485 DI 10.1103/PhysRevB.44.11482 PG 4 WC Physics, Condensed Matter SC Physics GA GR559 UT WOS:A1991GR55900054 ER PT J AU RESSELL, MT AF RESSELL, MT TI LIMITS TO THE RADIATIVE DECAY OF THE AXION SO PHYSICAL REVIEW D LA English DT Article ID STRONG CP PROBLEM; X-RAY-EMISSION; DARK MATTER; SPECTROPHOTOMETRIC STANDARDS; INVISIBLE AXIONS; HADRONIC AXIONS; GALACTIC HALOES; NIGHT-SKY; CLUSTERS; GALAXIES AB An axion with a mass greater than 1 eV should be detectable through its decay into two photons. In this paper I discuss the astrophysical and cosmological limits which define a small window of allowed axion mass above 3 eV. A firm upper bound to the axion's mass of m(a) less-than-or-equal-to 8 eV is derived by considering the effect of decaying axions upon the diffuse extragalactic background radiation and the brightness of the night sky due to axions in the halo of our Galaxy. The intergalactic light of clusters of galaxies is shown to be an ideal place to search for an emission line arising from the radiative decay of axions. An unsuccessful search for this emission line in three clusters of galaxies is then detailed. Limits to the presence of any intracluster line emission are derived with the result that axions with masses between 3 and 8 eV are excluded by the data, effectively closing this window of axion mass, unless a severe cancellation of axionic decay amplitudes occurs. The intracluster flux limits are then used to constrain the amplitude of any such model dependence. C1 FERMI NATL ACCELERATOR LAB,NASA,FERMILAB ASTROPHYS CTR,BATAVIA,IL 60510. RP RESSELL, MT (reprint author), UNIV CHICAGO,ENRICO FERMI INST,DEPT ASTRON & ASTROPHYS,CHICAGO,IL 60637, USA. NR 62 TC 49 Z9 49 U1 2 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 NOV 15 PY 1991 VL 44 IS 10 BP 3001 EP 3020 DI 10.1103/PhysRevD.44.3001 PG 20 WC Astronomy & Astrophysics; Physics, Particles & Fields SC Astronomy & Astrophysics; Physics GA GT643 UT WOS:A1991GT64300008 ER PT J AU KAMIONKOWSKI, M AF KAMIONKOWSKI, M TI ENERGETIC NEUTRINOS FROM HEAVY-NEUTRALINO ANNIHILATION IN THE SUN SO PHYSICAL REVIEW D LA English DT Article ID COLD-DARK-MATTER; COSMIC-RAY ANTIPROTONS; PHOTINO-DOMINATED UNIVERSE; ASTROPHYSICAL IMPLICATIONS; HIGGS BOSONS; GAMMA-RAYS; SUPERSYMMETRIC MODELS; MASSIVE PARTICLES; STANDARD MODEL; PROBE AB Neutralinos may be captured in the Sun and annihilate therein producing high-energy neutrinos. Present limits on the flux of such neutrinos from underground detectors such as Irvine-Michigan-Brookhaven (IMB) and Kamiokande II may be used to rule out certain supersymmetric dark-matter candidates, while in many other supersymmetric models the rates are large enough that if neutralinos do reside in the galactic halo, observation of a neutrino signal may be possible in the near future. Neutralinos that are either nearly pure Higgsino or a Higgsino-gaugino combination are generally captured in the Sun by a scalar interaction with nuclei in which a virtual lightest Higgs boson is exchanged. If the squark mass is not much greater than the neutralino mass then capture of neutralinos that are primarily gaugino occurs predominantly by spin-dependent scattering off hydrogen in the Sun. Although only neutrinos from annihilation in the Sun are considered here, the neutrino signal from weakly interacting massive particle annihilation in the Earth should be of comparable strength. Detection rates for mixed-state neutralinos are generally higher than those for Higgsinos or gauginos. C1 UNIV CHICAGO,DEPT PHYS,CHICAGO,IL 60637. FERMI NATL ACCELERATOR LAB,NASA,FERMILAB ASTROPHYS CTR,BATAVIA,IL 60510. UNIV CHICAGO,ENRICO FERMI INST,CHICAGO,IL 60637. NR 91 TC 106 Z9 106 U1 0 U2 0 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 0556-2821 J9 PHYS REV D JI Phys. Rev. D PD NOV 15 PY 1991 VL 44 IS 10 BP 3021 EP 3042 DI 10.1103/PhysRevD.44.3021 PG 22 WC Astronomy & Astrophysics; Physics, Particles & Fields SC Astronomy & Astrophysics; Physics GA GT643 UT WOS:A1991GT64300009 ER PT J AU KURKISUONIO, H GRAZIANI, F MATHEWS, GJ AF KURKISUONIO, H GRAZIANI, F MATHEWS, GJ TI PROSPECTS FOR OBSERVING SUBHORIZON PREINFLATION FLUCTUATIONS IN THE COSMIC MICROWAVE BACKGROUND SO PHYSICAL REVIEW D LA English DT Article ID INFLATIONARY-UNIVERSE; COSMOLOGICAL PERTURBATIONS; ANISOTROPY AB We consider constraints on preinflation subhorizon fluctuations in a chaotic inflationary model. The requirement that the energy density in the fluctuating field not exceed the Planck scale limits the amplitude of the fluctuations. The requirement that the preinflation fluctuations have a presently observable amplitude that is at least comparable to the quantum fluctuations generated during inflation constrains the length scale of the fluctuations. We show that in order for preinflation fluctuations to be observable above the background due to quantum fluctuations generated during inflation, they must have a scale at least comparable to the preinflation Hubble length. Unless OMEGA-0 > 0.94, such fluctuations could be observable in the present microwave background with a wavelength less than the present observed horizon. RP KURKISUONIO, H (reprint author), UNIV CALIF LAWRENCE LIVERMORE NATL LAB,LIVERMORE,CA 94550, USA. RI Kurki-Suonio, Hannu/B-8502-2016 OI Kurki-Suonio, Hannu/0000-0002-4618-3063 NR 24 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 0556-2821 J9 PHYS REV D JI Phys. Rev. D PD NOV 15 PY 1991 VL 44 IS 10 BP 3072 EP 3076 DI 10.1103/PhysRevD.44.3072 PG 5 WC Astronomy & Astrophysics; Physics, Particles & Fields SC Astronomy & Astrophysics; Physics GA GT643 UT WOS:A1991GT64300014 ER PT J AU LAGUNA, P KURKISUONIO, H MATZNER, RA AF LAGUNA, P KURKISUONIO, H MATZNER, RA TI INHOMOGENEOUS INFLATION - THE INITIAL-VALUE PROBLEM SO PHYSICAL REVIEW D LA English DT Article ID UNIVERSE; COSMOLOGY; FLATNESS; SYMMETRY; HORIZON AB We present a spatially three-dimensional study for solving the initial-value problem in general relativity for inhomogeneous cosmologies. We use York's conformal approach to solve the constraint equations of Einstein's field equations for scalar field sources and find the initial data which will be used in the evolution. This work constitutes the first stage in the development of a code to analyze the effects of matter and spacetime inhomogeneities on inflation. C1 UNIV CALIF LAWRENCE LIVERMORE NATL LAB,LIVERMORE,CA 94550. UNIV TEXAS,CTR RELAT,AUSTIN,TX 78712. RP LAGUNA, P (reprint author), UNIV CALIF LOS ALAMOS SCI LAB,DIV THEORET,LOS ALAMOS,NM 87545, USA. RI Kurki-Suonio, Hannu/B-8502-2016 OI Kurki-Suonio, Hannu/0000-0002-4618-3063 NR 23 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 0556-2821 J9 PHYS REV D JI Phys. Rev. D PD NOV 15 PY 1991 VL 44 IS 10 BP 3077 EP 3086 DI 10.1103/PhysRevD.44.3077 PG 10 WC Astronomy & Astrophysics; Physics, Particles & Fields SC Astronomy & Astrophysics; Physics GA GT643 UT WOS:A1991GT64300015 ER PT J AU GUPTA, R BAILLIE, CF BRICKNER, RG KILCUP, GW PATEL, A SHARPE, SR AF GUPTA, R BAILLIE, CF BRICKNER, RG KILCUP, GW PATEL, A SHARPE, SR TI QCD WITH DYNAMIC WILSON FERMIONS .2. SO PHYSICAL REVIEW D LA English DT Article ID HYBRID MONTE-CARLO; LATTICE QCD; CURRENT-ALGEBRA; BARYON OCTET; SPECTRUM; MASSES; MODEL AB We present results for the QCD spectrum and the matrix elements of scalar and axial-vector densities at beta = 6/g2 = 5.4, 5.5, 5.6. The lattice update was done using the hybrid Monte Carlo algorithm to include two flavors of dynamical Wilson fermions. We have explored quark masses in the range m(s) less-than-or-equal-to m(q) less-than-or-equal-to 3 m(s). The results for the spectrum are similar to quenched simulations and mass ratios are consistent with pbenomenological heavy-quark models. The results for matrix elements of the scalar density show that the contribution of sea quarks is comparable to that of the valence quarks. This has important implications for the pion-nucleon-sigma term. C1 UNIV COLORADO,DEPT PHYS,BOULDER,CO 80309. UNIV CALIF LOS ALAMOS SCI LAB,DIV C,LOS ALAMOS,NM 87545. OHIO STATE UNIV,DEPT PHYS,COLUMBUS,OH 43210. INDIAN INST SCI,SUPERCOMP EDUC & RES CTR,BANGALORE 560012,KARNATAKA,INDIA. INDIAN INST SCI,CTR THEORET STUDIES,BANGALORE 560012,KARNATAKA,INDIA. UNIV WASHINGTON,DEPT PHYS,SEATTLE,WA 98195. RP GUPTA, R (reprint author), UNIV CALIF LOS ALAMOS SCI LAB,T-8,MS-B285,LOS ALAMOS,NM 87545, USA. RI Patel, Apoorva/F-4359-2010 NR 33 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 0556-2821 J9 PHYS REV D JI Phys. Rev. D PD NOV 15 PY 1991 VL 44 IS 10 BP 3272 EP 3292 DI 10.1103/PhysRevD.44.3272 PG 21 WC Astronomy & Astrophysics; Physics, Particles & Fields SC Astronomy & Astrophysics; Physics GA GT643 UT WOS:A1991GT64300036 ER PT J AU KLEPEIS, JE SCHAFER, KJ BARBEE, TW ROSS, M AF KLEPEIS, JE SCHAFER, KJ BARBEE, TW ROSS, M TI HYDROGEN-HELIUM MIXTURES AT MEGABAR PRESSURES - IMPLICATIONS FOR JUPITER AND SATURN SO SCIENCE LA English DT Article ID PHASE-SEPARATION; STATISTICAL-MECHANICS; IONIC MIXTURES; LIGHT-ELEMENTS; STATE; EQUATION; FLUID; ENERGY AB Models of Jupiter and Saturn postulate a central rock core surrounded by a fluid mixture of hydrogen and helium. These models suggest that the mixture is undergoing phase separation in Saturn but not Jupiter. State-of-the-art total energy calculations of the enthalpy of mixing for ordered alloys of hydrogen and helium confirm that at least partial phase separation has occurred in Saturn and predict that this process has also begun in Jupiter. RP KLEPEIS, JE (reprint author), UNIV CALIF LAWRENCE LIVERMORE NATL LAB,LIVERMORE,CA 94550, USA. NR 22 TC 37 Z9 37 U1 0 U2 2 PU AMER ASSOC ADVANCEMENT SCIENCE PI WASHINGTON PA 1200 NEW YORK AVE, NW, WASHINGTON, DC 20005 SN 0036-8075 J9 SCIENCE JI Science PD NOV 15 PY 1991 VL 254 IS 5034 BP 986 EP 989 DI 10.1126/science.254.5034.986 PG 4 WC Multidisciplinary Sciences SC Science & Technology - Other Topics GA GP883 UT WOS:A1991GP88300038 PM 17731520 ER PT J AU UZIEL, M HOUCK, K AF UZIEL, M HOUCK, K TI DIRECT LABELING OF DNA-ADDUCTS FORMED FROM CARCINOGENIC DIOL-EPOXIDES WITH A FLUORESCENT REPORTER COMPOUND SPECIFIC FOR THE CIS VIC-DIOL GROUP SO BIOCHEMICAL AND BIOPHYSICAL RESEARCH COMMUNICATIONS LA English DT Article ID BENZOPYRENE-DNA ADDUCTS; BINDING; INVIVO; DAMAGE; ASSAY RP UZIEL, M (reprint author), OAK RIDGE NATL LAB,DIV HLTH & SAFETY RES,OAK RIDGE,TN 37831, USA. NR 14 TC 2 Z9 2 U1 0 U2 0 PU ACADEMIC PRESS INC JNL-COMP SUBSCRIPTIONS PI SAN DIEGO PA 525 B ST, STE 1900, SAN DIEGO, CA 92101-4495 SN 0006-291X J9 BIOCHEM BIOPH RES CO JI Biochem. Biophys. Res. Commun. PD NOV 14 PY 1991 VL 180 IS 3 BP 1233 EP 1240 DI 10.1016/S0006-291X(05)81328-2 PG 8 WC Biochemistry & Molecular Biology; Biophysics SC Biochemistry & Molecular Biology; Biophysics GA GP332 UT WOS:A1991GP33200011 PM 1953775 ER PT J AU ZHOU, XL CHEN, SH FELCHER, GP AF ZHOU, XL CHEN, SH FELCHER, GP TI NEW ANALYTICAL FORMULA FOR NEUTRON REFLECTION FROM SURFACE-FILMS SO JOURNAL OF PHYSICAL CHEMISTRY LA English DT Article AB The closed-form expressions for the neutron reflectance and transmittance of a thin film deposited on a bulk substrate are derived from the Green's function solution of the Schroedinger wave equation in the material medium with an optical potential under the approximation that the curvature of the scattering length density profile in the film is small. This closed-form solution reduces to all the known approximations in various limiting cases and is shown to be more accurate than the existing approximations. C1 MIT,DEPT NUCL ENGN,CAMBRIDGE,MA 02139. ARGONNE NATL LAB,ARGONNE,IL 60439. NR 9 TC 13 Z9 13 U1 0 U2 0 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 SN 0022-3654 J9 J PHYS CHEM-US JI J. Phys. Chem. PD NOV 14 PY 1991 VL 95 IS 23 BP 9025 EP 9029 DI 10.1021/j100176a001 PG 5 WC Chemistry, Physical SC Chemistry GA GQ457 UT WOS:A1991GQ45700001 ER PT J AU COSTANTINO, M RICE, SF AF COSTANTINO, M RICE, SF TI SUPERCRITICAL PHASE-SEPARATION IN H2O-N2 MIXTURES SO JOURNAL OF PHYSICAL CHEMISTRY LA English DT Article ID HIGH-PRESSURES; CRITICAL LINE; EQUILIBRIA; SYSTEM; FLUID; KBAR AB We report phase separation of supercritical mixtures of H2O and N2 at pressures to 2.1 GPa and temperatures to 830 K on the 75 mol% water isopleth. The composition is fixed by loading a diamond anvil cell with a known mixture at temperatures above 400-degrees-C and pressures above 150 MPa. We measure the pressure using the pressure dependence of the Sm3+:YAG fluorescence line at 6178 angstrom. The shape of the coexistence curve for this isopleth implies a critical curve with a relatively weak dependence of the phase separation pressure on the temperature. RP COSTANTINO, M (reprint author), UNIV CALIF LAWRENCE LIVERMORE NATL LAB,DEPT CHEM & MAT SCI,L-369,LIVERMORE,CA 94550, USA. NR 18 TC 30 Z9 31 U1 1 U2 4 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 NOV 14 PY 1991 VL 95 IS 23 BP 9034 EP 9036 DI 10.1021/j100176a004 PG 3 WC Chemistry, Physical SC Chemistry GA GQ457 UT WOS:A1991GQ45700004 ER PT J AU HAN, P BARTELS, DM AF HAN, P BARTELS, DM TI H/D ISOTOPE EFFECTS IN WATER RADIOLYSIS .3. ATOMIC-HYDROGEN IN ACIDIC H2O/D2O MIXTURES SO JOURNAL OF PHYSICAL CHEMISTRY LA English DT Article ID ELECTRON; KINETICS AB We present measurements of the EPR spectra of H and D atoms immediately (30-50 ns) following pulse radiolysis of acidic H2O/D2O mixtures with 3-MeV electrons. The spectra exhibit a low-field emission/high-field absorption (E/A) polarization pattern of chemically induced dynamic electron polarization (CIDEP), which is characteristic of random (uncorrelated spin) recombination reactions of free radicals in the radiolysis spurs. As in previous work, we analyze the CIDEP amplitudes to deduce the isotope effect alpha = (H/D)product/(H/D)water which characterizes the formation of the H and D atoms. The relative H and D signal intensities can be accounted for in terms of two strong isotope effects demonstrated in previous work: (a) reaction of hydrated electrons with hydronium ions to give H (or D) and (b) the dissociation of the electronically excited HDO* molecule to give preferentially H. It is estimated that the direct dissociation channel accounts for G congruent-to 0.3 of the atomic hydrogen yield in radiolysis of both acidic and alkaline water. C1 ARGONNE NATL LAB,DIV CHEM,ARGONNE,IL 60439. NR 26 TC 3 Z9 3 U1 1 U2 1 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 NOV 14 PY 1991 VL 95 IS 23 BP 9370 EP 9374 DI 10.1021/j100176a061 PG 5 WC Chemistry, Physical SC Chemistry GA GQ457 UT WOS:A1991GQ45700061 ER PT J AU PALMANS, R FRANK, AJ AF PALMANS, R FRANK, AJ TI A MOLECULAR WATER-REDUCTION CATALYST - SURFACE DERIVATIZATION OF TIO2 COLLOIDS AND SUSPENSIONS WITH A PLATINUM COMPLEX SO JOURNAL OF PHYSICAL CHEMISTRY LA English DT Article ID HETEROGENEOUS PHOTOCATALYTIC OXIDATION; INTERFACIAL ELECTRON-TRANSFER; SPECTRAL SENSITIZATION; TITANIUM-DIOXIDE; SEMICONDUCTOR ELECTRODES; AQUEOUS SUSPENSIONS; CARBON-DIOXIDE; ZINC-OXIDE; SACRIFICIAL PHOTOLYSIS; HYDROGEN-PRODUCTION AB Room-temperature irradiation of alkaline solutions (pH > 8) of [Pt(bpy)2]2+ (where bpy is 2,2'-bipyridine) in the presence of TiO2-SiO2 (or TiO2) colloids or TiO2 powder suspensions and an electron donor results in the loss of one bipyridyl ligand and the chemical fixation of Pt(bpy) to the TiO2 surface via the formation of Ti-O-Pt bonds. The chemical derivatization of TiO2 with Pt(bpy) is pH dependent and proceeds through a Ti-O-Pt(bpy)2 intermediary. X-ray photoelectron spectroscopy analysis indicates that the heterometallic surface complex Ti-O-Pt(bpy) exists in the Pt(0) and Pt(I) oxidation state. The surface complex exhibits a metal-to-ligand charge-transfer absorption band in the visible region of the spectrum. Direct excitation of either the semiconductor or the photosensitizer [Ru(bpy)3]2+, electrostatically adsorbed to colloidal SiO2-TiO2, initiates both the surface derivatization of TiO2 and the subsequent generation of H-2. Large turnover numbers (H-2 concentration/[Pt(bpy)2]2+ >> 1) are observed, indicating that the Pt(bpy) species on the TiO2 surface is catalytic and is therefore regenerated during the photoreduction of water. The rates of H-2 evolution with Pt(bpy)-TiO2 particles are higher in acidic than basic media. The photocatalytic activity of these particles for H-2 production compares favorably with that of other TiO2 systems charged with an equivalent Pt loading. C1 NATL RENEWABLE ENERGY LAB,1617 COLE BLVD,GOLDEN,CO 80401. NR 87 TC 22 Z9 22 U1 0 U2 15 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 NOV 14 PY 1991 VL 95 IS 23 BP 9438 EP 9443 DI 10.1021/j100176a075 PG 6 WC Chemistry, Physical SC Chemistry GA GQ457 UT WOS:A1991GQ45700075 ER PT J AU HENDRICKS, WM BELL, AT RADKE, CJ AF HENDRICKS, WM BELL, AT RADKE, CJ TI EFFECTS OF ORGANIC AND ALKALI-METAL CATIONS ON THE DISTRIBUTION OF SILICATE ANIONS IN AQUEOUS-SOLUTIONS SO JOURNAL OF PHYSICAL CHEMISTRY LA English DT Article ID NUCLEAR MAGNETIC-RESONANCE; SI-29 NMR-SPECTROSCOPY; PATTERNS AB The effects of tetraalkylammonium (TAA) cations on the equilibrium distribution of silicate oligomers in aqueous alkaline silicate solutions have been investigated using Si-29 NMR spectroscopy. The results indicate that intrinsic differences exist in the interactions involving TAA cations and those involving alkali metal cations. The large size of the TAA cations precludes significant ion pairing; however, hydrophobic solvation and ion crowding play important roles in determining silicate speciation at equilibrium. C1 UNIV CALIF BERKELEY,LAWRENCE BERKELEY LAB,CTR ADV MAT,BERKELEY,CA 94720. UNIV CALIF BERKELEY,DEPT CHEM ENGN,BERKELEY,CA 94720. OI Bell, Alexis/0000-0002-5738-4645 NR 33 TC 27 Z9 28 U1 3 U2 8 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 NOV 14 PY 1991 VL 95 IS 23 BP 9513 EP 9518 DI 10.1021/j100176a087 PG 6 WC Chemistry, Physical SC Chemistry GA GQ457 UT WOS:A1991GQ45700087 ER PT J AU HENDRICKS, WM BELL, AT RADKE, CJ AF HENDRICKS, WM BELL, AT RADKE, CJ TI EFFECTS OF SOLVENT STRUCTURE ON THE DISTRIBUTION OF SILICATE ANIONS IN MIXED AQUEOUS ORGANIC SOLUTIONS OF ALKALINE TETRAMETHYLAMMONIUM SILICATE SO JOURNAL OF PHYSICAL CHEMISTRY LA English DT Article AB Effects of solvent structure on the equilibrium distribution of silicate oligomers in mixed organic/aqueous solutions of tetramethylammonium hydroxide (TMAOH) have been investigated by using Si-29 NMR spectroscopy. The results indicate that the presence of organic molecules leads to condensation of the silicates, particularly to double-ring structures. Equilibrium calculations indicate that the observed extent of silicate condensation exceeds what would be expected from mass action. The variety of organic solvents used allowed elucidation of structure effects due to the following: carbon chain length, carbon chain morphology, functional group, and placement of the functional group. The structural effects of organic solvents can be attributed to the ordering of water around the solvent molecules. C1 UNIV CALIF BERKELEY,LAWRENCE BERKELEY LAB,CTR ADV MAT,BERKELEY,CA 94720. UNIV CALIF BERKELEY,DEPT CHEM ENGN,BERKELEY,CA 94720. OI Bell, Alexis/0000-0002-5738-4645 NR 5 TC 19 Z9 19 U1 0 U2 1 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 NOV 14 PY 1991 VL 95 IS 23 BP 9519 EP 9524 DI 10.1021/j100176a088 PG 6 WC Chemistry, Physical SC Chemistry GA GQ457 UT WOS:A1991GQ45700088 ER PT J AU AUMAYR, F LEE, W SKINNER, CH SUCKEWER, S AF AUMAYR, F LEE, W SKINNER, CH SUCKEWER, S TI QUENCHING OF EINSTEIN COEFFICIENTS BY PHOTONS SO JOURNAL OF PHYSICS B-ATOMIC MOLECULAR AND OPTICAL PHYSICS LA English DT Article ID SPONTANEOUS-EMISSION COEFFICIENTS; PLASMAS AB Experimental evidence is presented for the change of Einstein's A coefficients for spontaneous transitions from the upper laser level of an argon ion laser discharge due to the presence of a high-intensity laser flux. To demonstrate that this quenching effect cannot be attributed to a reduction in self-absorption of the strong spontaneous emission line, absorption and line profile measurements have been performed. Computer modelling of the reduction of self-absorption due to Rabi splitting also indicated that this effect is too small to explain the observed quenching of spontaneous line emissions. C1 PRINCETON UNIV,DEPT MECH & AEROSP ENGN,PRINCETON,NJ 08544. PRINCETON UNIV,PLASMA PHYS LAB,PRINCETON,NJ 08544. RI Aumayr, Friedrich/A-3920-2009 OI Aumayr, Friedrich/0000-0002-9788-0934 NR 15 TC 2 Z9 2 U1 0 U2 2 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 NOV 14 PY 1991 VL 24 IS 21 BP 4489 EP 4504 DI 10.1088/0953-4075/24/21/005 PG 16 WC Optics; Physics, Atomic, Molecular & Chemical SC Optics; Physics GA GQ355 UT WOS:A1991GQ35500005 ER PT J AU SPENCE, JR VARY, JP AF SPENCE, JR VARY, JP TI ELECTRON-PROTON RESONANCES AT LOW-ENERGY FROM A RELATIVISTIC 2-BODY WAVE-EQUATION SO PHYSICS LETTERS B LA English DT Article ID CONFINING POTENTIALS; SPECTRA AB The K-matrix for electron-proton scattering is evaluated in the 0- channel from 0.05 to 5.0 eV using a relativistic wave equation derived from QED. We find very narrow resonances at E(cm) = 0.748, 1.347, 2.095, 3.032, and 4.707 eV. Since these are short-distance phenomena, these resonances may provide a super screening mechanism for fusion reactions. C1 IOWA STATE UNIV SCI & TECHNOL,DEPT PHYS & ASTRON,AMES,IA 50011. RP SPENCE, JR (reprint author), IOWA STATE UNIV SCI & TECHNOL,US DOE,AMES LAB,AMES,IA 50011, USA. NR 21 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 NOV 14 PY 1991 VL 271 IS 1-2 BP 27 EP 31 DI 10.1016/0370-2693(91)91272-W PG 5 WC Astronomy & Astrophysics; Physics, Nuclear; Physics, Particles & Fields SC Astronomy & Astrophysics; Physics GA GT794 UT WOS:A1991GT79400006 ER PT J AU GIVEON, A HALL, LJ SARID, U AF GIVEON, A HALL, LJ SARID, U TI SU(5) UNIFICATION REVISITED SO PHYSICS LETTERS B LA English DT Article ID GAUGE-THEORIES; GRAND UNIFICATION; MASSES; SUPERSYMMETRY; EQUATIONS; MODEL; WEAK AB Model-independent criteria for unification in the SU (5) framework are studied. These are applied to the minimal supersymmetric standard model and to the standard model with a split 45 Higgs representation. Although the former is consistent with SU (5) unification, the superpartner masses can vary over a wide range, and may even all lie well beyond the reach of planned colliders. Adding a split 45 to the standard model can also satisfy the unification criteria. so supersymmetric SU (5) is far from unique. Furthermore, we learn that separate Higgs doublets must couple to the top and bottom quarks in order to give a correct m(b)/m(tau) prediction. C1 UNIV CALIF BERKELEY,DEPT PHYS,BERKELEY,CA 94720. RP GIVEON, A (reprint author), UNIV CALIF BERKELEY,LAWRENCE BERKELEY LAB,1 CYCLOTRON RD 50A-3115,BERKELEY,CA 94720, USA. NR 30 TC 69 Z9 69 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 NOV 14 PY 1991 VL 271 IS 1-2 BP 138 EP 144 DI 10.1016/0370-2693(91)91289-8 PG 7 WC Astronomy & Astrophysics; Physics, Nuclear; Physics, Particles & Fields SC Astronomy & Astrophysics; Physics GA GT794 UT WOS:A1991GT79400023 ER PT J AU PORRATI, M GIRARDELL, L AF PORRATI, M GIRARDELL, L TI QUANTUM-MECHANICAL AND FIELD THEORETICAL-MODELS OF NONPERTURBATIVE HIGH-ENERGY INTERACTIONS SO PHYSICS LETTERS B LA English DT Article ID WEINBERG-SALAM THEORY; WEAK-INTERACTIONS; GAUGE-THEORIES; INSTANTONS; BEHAVIOR; FREEDOM; TEV AB We study non-perturbative high energy fermion number violating transition amplitudes in a quantum mechanical model containing interacting bosonic and fermionic degrees of freedom. We find that these transition amplitudes are always exponentially suppressed by at least one half of the low energy suppression factor exp(-S0/HBAR). We argue that this result is valid for the field theoretical case as well. C1 IST NAZL FIS NUCL,SEZIONE PISA,I-56100 PISA,ITALY. UNIV MILANO,DIPARTIMENTO FIS,I-20133 MILAN,ITALY. IST NAZL FIS NUCL,SEZIONE MILANO,I-20133 MILAN,ITALY. RP PORRATI, M (reprint author), UNIV CALIF BERKELEY,LAWRENCE BERKELEY LAB,DEPT PHYS,BERKELEY,CA 94720, USA. NR 28 TC 6 Z9 6 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 NOV 14 PY 1991 VL 271 IS 1-2 BP 148 EP 154 DI 10.1016/0370-2693(91)91291-3 PG 7 WC Astronomy & Astrophysics; Physics, Nuclear; Physics, Particles & Fields SC Astronomy & Astrophysics; Physics GA GT794 UT WOS:A1991GT79400025 ER PT J AU ALTHERR, T GRANDOU, T PISARSKI, RD AF ALTHERR, T GRANDOU, T PISARSKI, RD TI THERMAL-INSTABILITY IN (PHI(3))6 SO PHYSICS LETTERS B LA English DT Article ID FINITE TEMPERATURE; CURVED SPACE; FIELD-THEORY; SINGULARITIES; TIME AB At zero temperature a (phi-3)6 theory is perturbatively stable in the cubic coupling constant, g, if the mass squared is positive, m2 > 0. At nonzero temperature there is a critical temperature T(cr) above which perturbative stability is lost. In weak coupling, T(cr) = (180/pi)1/4m/square-root g C1 BROOKHAVEN NATL LAB,DEPT PHYS,UPTON,NY 11973. UNIV NICE,INST NON LINEARIRE NICE,F-06034 NICE,FRANCE. RP ALTHERR, T (reprint author), CNRS,ANNECY VIEUX PHYS PARTICULES LAB,IN2P3,CHEMIN BELLEVUE,BP 110,F-74941 ANNECY LE VIEUX,FRANCE. NR 22 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 NOV 14 PY 1991 VL 271 IS 1-2 BP 183 EP 186 DI 10.1016/0370-2693(91)91297-9 PG 4 WC Astronomy & Astrophysics; Physics, Nuclear; Physics, Particles & Fields SC Astronomy & Astrophysics; Physics GA GT794 UT WOS:A1991GT79400031 ER PT J AU SHARMA, VK BIELSKI, BHJ AF SHARMA, VK BIELSKI, BHJ TI REACTIVITY OF FERRATE(VI) AND FERRATE(V) WITH AMINO-ACIDS SO INORGANIC CHEMISTRY LA English DT Article ID ELECTRON-SPIN-RESONANCE; PULSE-RADIOLYSIS; AQUEOUS-SOLUTIONS; HYDROGEN-PEROXIDE; FREE-RADICALS; IRON; OXIDATION; REDUCTION; COMPLEXES; TRYPTOPHAN AB The oxidation of the essential amino acids by ferrate(VI) (Fe(VI)) and ferrate(V) (Fe(V)) has been studied by stopped-flow and pulse radiolysis techniques at pH 12.4 and 23-24-degrees-C. FeO43- was formed in these studies by reduction of Fe(VI) with radiation-generated reducing radicals. Both Fe(VI) and Fe(V) react preferentially with amino acids in which the alpha-amino group is protonated (RCH(NH3+)COO-). Rate constants (k5) for reactions of Fe(VI) with RCH(NH3+)COO- range from 10 to 10(3) M-1 s-1. The corresponding k6 values for Fe(V) are orders of magnitude higher: k6 = (0.01-5.0) x 10(7) M-1 s-1. Cysteine, a reducing species, reacts with Fe(VI) at a rate of k = 760 +/- 49 M-1 s-1 and with FeO43- at a nearly diffusion-controlled rate of k = (4.0 +/- 0.8) x 10(9) M-1 s-1; both rates were computed on the basis of [cysteine]tot. The ratio k6/k5 varies from 5 x 10(3) to 3 x 10(5); for cysteine this ratio is 5 x 10(6). The oxidation process of amino acids initiated by Fe(V) proceeds in presence of Fe(VI) by a chain reaction in which amino acid free radicals and Fe(V) are the chain carriers. C1 BROOKHAVEN NATL LAB,DEPT CHEM,UPTON,NY 11973. OI Sharma, Virender/0000-0002-5980-8675 NR 51 TC 88 Z9 95 U1 1 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 NOV 13 PY 1991 VL 30 IS 23 BP 4306 EP 4310 DI 10.1021/ic00023a005 PG 5 WC Chemistry, Inorganic & Nuclear SC Chemistry GA GP945 UT WOS:A1991GP94500005 ER PT J AU ROWANGORDON, N NGUYENPHO, AA MONDONKONAN, E TURNER, AH BUTCHER, RJ OKONKWO, AS HAYDEN, HH STORM, CB AF ROWANGORDON, N NGUYENPHO, AA MONDONKONAN, E TURNER, AH BUTCHER, RJ OKONKWO, AS HAYDEN, HH STORM, CB TI ELECTROPHILIC SUBSTITUTION-REACTIONS IN HETEROCYCLES COMPLEXED TO EXCHANGE-INERT METAL-IONS - (ETHYLENEDIAMINE)COBALT(III) COMPLEXES OF IMIDAZOLE AND HISTIDINE SO INORGANIC CHEMISTRY LA English DT Article ID COBALT(III) COMPLEXES; LIGAND; NMR AB (Ethylenediamine)cobalt(III) complexes of imidazole and histidine are nitrated under mild conditions with a standard HNO3-H2SO4 nitrating mixture. In contrast to the more robust pentaamminecobalt(III) complexes, the nitrate imidazole ligand readily dissociates, providing an excellent synthetic route to a variety of nitroimidazoles. Pyridine coordinated to either Co(NH3)5(3+) or Co(en)2Cl2+ is not nitrated, even under conditions that destroy the complex. The difference in reactivity is evidently a reflection of the Co(III) d electron interaction with the lowest unoccupied molecular orbital (LUMO) of the ligand. The nucleophilic displacement of a nitro group by chloride in a coordinated nitroimidazole is also observed. Crystal data for bis(ethylenediamine)(benzimidazole)chlorocobalt(III) perchlorate, space group P1BAR, Z = 4, a = 8.168 (4) angstrom, b = 11.570 (4) angstrom, c = 21.162 (8) angstrom, alpha = 78.93 (2)-degrees, beta = 78.87 (2)-degrees, gamma = 69.24 (2)-degrees, and R = 6.67% for 3437 reflections; for bis(ethylenediamine)(pyridine)-chlorocobalt(III) chloride, space group P2(1)/n, a = 8.489 (3) angstrom, b = 14.021 (6) angstrom, c = 12.670 (6) angstrom, alpha = 90.0-degrees, beta = 91.63 (2)-degrees, gamma = 90.0-degrees, and R = 4.11% for 2185 reflections; for bis(ethylenediamine)(4-nitroimidazolato)chlorocobalt(III) chloride hydrate, space group P1BAR, a = 8.603 (5) angstrom, b = 7.358 (3) angstrom, c = 14.287 (7) angstrom, alpha = 95.82 (2)-degrees, beta = 86.79 (2)-degrees, gamma = 115.39 (2)-degrees, and R = 5.21% for 5903 reflections; for bis(ethylenediamine)(4-chloroimidazole)chlorocobalt(III) chloride, space group C2/c, Z = 8, a = 23.550 (6) angstrom, b = 11.805 (2) angstrom, c = 12.128 (3) angstrom, alpha = 90.0-degrees, beta = 115.92 (2)-degrees, gamma = 90.0-degrees, and R = 4.34% for 2377 reflections; and for (ethylenediamine)(4-nitrohistidinato-O,N,N')chlorocobalt(III) hydrate, space group P2(1).n, a = 8.544 (3) angstrom, b = 17.382 (5) angstrom, c = 10.256 (3) angstrom, alpha = 90.0-degrees, beta = 107.50 (2)-degrees, gamma = 90.0-degrees, and R = 5.60% for 2556 reflections, are reported. C1 HOWARD UNIV,DEPT CHEM,WASHINGTON,DC 20059. UNIV CALIF LOS ALAMOS SCI LAB,DEPT CHEM,LOS ALAMOS,NM 87545. RP ROWANGORDON, N (reprint author), AMERICAN UNIV,DEPT CHEM,WASHINGTON,DC 20016, USA. NR 33 TC 14 Z9 14 U1 0 U2 3 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 SN 0020-1669 J9 INORG CHEM JI Inorg. Chem. PD NOV 13 PY 1991 VL 30 IS 23 BP 4374 EP 4380 DI 10.1021/ic00023a017 PG 7 WC Chemistry, Inorganic & Nuclear SC Chemistry GA GP945 UT WOS:A1991GP94500017 ER PT J AU SHI, S ESPENSON, JH MEYERSTEIN, D MEISEL, D AF SHI, S ESPENSON, JH MEYERSTEIN, D MEISEL, D TI OXIDATIVE HOMOLYSIS REACTIONS BETWEEN ORGANOCHROMIUM MACROCYCLES AND DIHALIDE RADICAL-ANIONS SO INORGANIC CHEMISTRY LA English DT Note ID PULSE-RADIOLYSIS; COMPLEXES; CLEAVAGE C1 IOWA STATE UNIV SCI & TECHNOL,AMES LAB,AMES,IA 50011. IOWA STATE UNIV SCI & TECHNOL,DEPT CHEM,AMES,IA 50011. BEN GURION UNIV NEGEV,DEPT CHEM,IL-84120 BEER SHEVA,ISRAEL. ARGONNE NATL LAB,DIV CHEM,ARGONNE,IL 60439. NR 14 TC 6 Z9 6 U1 0 U2 0 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 SN 0020-1669 J9 INORG CHEM JI Inorg. Chem. PD NOV 13 PY 1991 VL 30 IS 23 BP 4468 EP 4470 DI 10.1021/ic00023a036 PG 3 WC Chemistry, Inorganic & Nuclear SC Chemistry GA GP945 UT WOS:A1991GP94500036 ER PT J AU TYAGARAJAN, K MONFORTE, JA HEARST, JE AF TYAGARAJAN, K MONFORTE, JA HEARST, JE TI RNA FOLDING DURING TRANSCRIPTION BY T7-RNA POLYMERASE ANALYZED USING THE SELF-CLEAVING TRANSCRIPT ASSAY SO BIOCHEMISTRY LA English DT Article ID TERNARY COMPLEXES; INITIATION; BACTERIOPHAGE-T7; CLEAVAGE AB We have used a self-cleaving RNA molecule (a "hammerhead") to study the length-dependent folding of RNA produced during transcription by T7 RNA polymerase. Transcript elongation is arrested at defined positions using chain-terminating ribonucleoside triphosphate analogues, 3'-deoxynucleoside triphosphates. When the nascent transcript attains the minimum length required for the "hammerhead" domain of the transcript to fully emerge from the ternary complex, the "hammerhead" structure forms and self-cleaves, producing a truncated product. The experiment yields an RNA sequencing ladder which terminates at the length at which cleavage becomes possible; the sequencing ladder is compared to that generated by using a noncleaving control template. We have shown that 13 nucleotides past the cleavage point must be synthesized before the transcript can self-cleave in the ternary complex whereas RNA freed from the complex by heating can cleave with only 3 or more nucleotides present beyond the cleavage site. The results indicate that the RNA in T7 RNA polymerase is not free of steric interactions in the ternary complex and not available for structure formation until it is at least 10 bases away from the site of polymerization. The results suggest that the maximum possible length of the RNA-DNA hybrid in the ternary complexes is 10. The relevance of the results in comparisons with other RNA polymerases, especially Escherichia coli RNA polymerase, is discussed. C1 UNIV CALIF BERKELEY,DEPT CHEM,HEARST RES GRP,BERKELEY,CA 94720. UNIV CALIF BERKELEY,LAWRENCE BERKELEY LAB,CHEM BIODYNAM LAB,BERKELEY,CA 94720. FU NIGMS NIH HHS [GM41911] NR 22 TC 14 Z9 14 U1 0 U2 0 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 SN 0006-2960 J9 BIOCHEMISTRY-US JI Biochemistry PD NOV 12 PY 1991 VL 30 IS 45 BP 10920 EP 10924 DI 10.1021/bi00109a016 PG 5 WC Biochemistry & Molecular Biology SC Biochemistry & Molecular Biology GA GP525 UT WOS:A1991GP52500016 PM 1932016 ER PT J AU ZHOU, P CHENG, JL SCHAUS, CF SUN, SZ HAINS, C ZHENG, K TORRES, A MYERS, DR VAWTER, GA AF ZHOU, P CHENG, JL SCHAUS, CF SUN, SZ HAINS, C ZHENG, K TORRES, A MYERS, DR VAWTER, GA TI HIGH-PERFORMANCE LATCHABLE OPTICAL SWITCH AND LOGIC GATES BASED ON THE INTEGRATION OF SURFACE-EMITTING LASERS AND PHOTOTHYRISTORS SO APPLIED PHYSICS LETTERS LA English DT Article AB Latching optical switches and cascadable optical logic gates AND and OR are demonstrated by the monolithic integration of a vertical-cavity surface-emitting laser with heterojunction photothyristors. Excellent optical switching characteristics, including low switching power (tens of nW), high optical gain (> 10(4)), and a large on/off ratio, have been achieved. C1 SANDIA NATL LABS,ALBUQUERQUE,NM 87185. RP ZHOU, P (reprint author), UNIV NEW MEXICO,CTR HIGH TECHNOL MAT,ALBUQUERQUE,NM 87131, USA. NR 7 TC 10 Z9 10 U1 0 U2 0 PU AMER INST PHYSICS PI WOODBURY PA CIRCULATION FULFILLMENT DIV, 500 SUNNYSIDE BLVD, WOODBURY, NY 11797-2999 SN 0003-6951 J9 APPL PHYS LETT JI Appl. Phys. Lett. PD NOV 11 PY 1991 VL 59 IS 20 BP 2504 EP 2506 DI 10.1063/1.105934 PG 3 WC Physics, Applied SC Physics GA GP275 UT WOS:A1991GP27500008 ER PT J AU KOIKE, J MITCHELL, TE PARKIN, DM AF KOIKE, J MITCHELL, TE PARKIN, DM TI FORMATION OF DEFECT CLUSTERS IN ELECTRON-IRRADIATED DIAMOND AT 16-K AND 87-K SO APPLIED PHYSICS LETTERS LA English DT Article ID ION-IMPLANTATION; LOW-TEMPERATURE; AMORPHIZATION; DEPENDENCE AB A type IIa natural diamond was irradiated with 300 kV electrons at 16 and 87 K. Transmission electron microscopy and electron energy-loss spectroscopy were employed to investigate the phase stability of diamond under electron irradiation. At both temperatures, the diamond structure was found to be stable, and the formation of defect clusters was observed. The present results in comparison to previous work on ion implantation indicate that displacement cascade damage is a prerequisite for irradiation-induced phase transformation from diamond to amorphous r-arbon or graphite. The temperature dependence of the cluster size suggests that interstitials are thermally mobile above 50 K. RP KOIKE, J (reprint author), UNIV CALIF LOS ALAMOS SCI LAB,CTR MAT SCI,LOS ALAMOS,NM 87545, 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 NOV 11 PY 1991 VL 59 IS 20 BP 2515 EP 2517 DI 10.1063/1.105938 PG 3 WC Physics, Applied SC Physics GA GP275 UT WOS:A1991GP27500012 ER PT J AU THOMPSON, JR SUN, YR MALOZEMOFF, AP CHRISTEN, DK KERCHNER, HR OSSANDON, JG MARWICK, AD HOLTZBERG, F AF THOMPSON, JR SUN, YR MALOZEMOFF, AP CHRISTEN, DK KERCHNER, HR OSSANDON, JG MARWICK, AD HOLTZBERG, F TI REDUCED FLUX MOTION VIA FLUX CREEP ANNEALING IN HIGH-JC SINGLE-CRYSTAL Y1BA2CU3O7 SO APPLIED PHYSICS LETTERS LA English DT Article ID TEMPERATURE SUPERCONDUCTORS; IRREVERSIBILITY AB We investigated the stabilization of magnetic flux in a high-temperature superconductor (a proton-irradiated Y1Ba2Cu3O7 crystal), by operating with subcritical current density J. Using the thermal history to obtain an induced current density J less-than-or-equal-to J(c), we observed a drastically reduced relaxation rate dM/dt (M = magnetization), after "flux creep annealing." The results show that the field gradient approximately J approximately M determined the relaxation rate, independent of the sample's H-T history, in agreement with recent theory. C1 UNIV TENNESSEE,KNOXVILLE,TN 37996. IBM CORP,THOMAS J WATSON LAB,YORKTOWN HTS,NY 10598. RP THOMPSON, JR (reprint author), OAK RIDGE NATL LAB,POB 2008,OAK RIDGE,TN 37831, USA. NR 16 TC 26 Z9 27 U1 0 U2 2 PU AMER INST PHYSICS PI WOODBURY PA CIRCULATION FULFILLMENT DIV, 500 SUNNYSIDE BLVD, WOODBURY, NY 11797-2999 SN 0003-6951 J9 APPL PHYS LETT JI Appl. Phys. Lett. PD NOV 11 PY 1991 VL 59 IS 20 BP 2612 EP 2614 DI 10.1063/1.105918 PG 3 WC Physics, Applied SC Physics GA GP275 UT WOS:A1991GP27500045 ER PT J AU MANSFIELD, KF THEODOROU, DN AF MANSFIELD, KF THEODOROU, DN TI MOLECULAR-DYNAMICS SIMULATION OF A GLASSY POLYMER SURFACE SO MACROMOLECULES LA English DT Article ID LIQUID VAPOR INTERFACE; LENNARD-JONES LIQUID; LINKED RIGID BODIES; COMPUTER-SIMULATION; BROWNIAN DYNAMICS; ISOMERIZATION DYNAMICS; CANONICAL ENSEMBLE; CHAIN MOLECULES; NORMAL-BUTANE; MONTE-CARLO AB The free surface of glassy atactic polypropylene is studied by molecular dynamics computer simulation. A model film system exposed to vacuum on both sides is examined at a temperature 22-degrees-C below the experimental glass transition temperature of the bulk polymer. The vinyl chains are represented as collections of backbone carbon atoms with united atom pendant methyl groups and explicit hydrogens. Bond lengths are held fixed, while bond angles are flexible. Simulations have been performed for durations of up to 400 ps and incorporate density profile dependent long-range contributions to the energy and stress. The spatial dependence of the short-time dynamical properties of the model film has been determined. Enhancements in the mean-squared displacement of atoms, in the orientational relaxation of backbone bonds, and in the rate of torsion angle fluctuations within a conformational state are observed near the free surface. One must penetrate into the film by approximately 15 angstrom from the extreme edge before observing a behavior in these dynamical features that resembles that of the bulk glassy polymer. This "dynamical interfacial thickness" is twice as large as the thickness over which the mass density profile varies. The center of mass motion of chains located as far as 2-3 times the unperturbed radius of gyration from the edge of the free surface is enhanced and highly anisotropic. Conformational transitions in the glassy polymer film have been analyzed. The glass is found to contain many "soft spots", where transitions occur with rates comparable to those observed in polymer liquids, as well as "stiff" regions, where the transitions are virtually arrested. An average rate for conformational isomerization in the polymer has been calculated by constructing a hazard plot of first passage times. 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 83 TC 267 Z9 268 U1 2 U2 56 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 SN 0024-9297 J9 MACROMOLECULES JI Macromolecules PD NOV 11 PY 1991 VL 24 IS 23 BP 6283 EP 6294 DI 10.1021/ma00023a034 PG 12 WC Polymer Science SC Polymer Science GA GQ428 UT WOS:A1991GQ42800034 ER PT J AU KERN, J RAEMY, A BEER, W DOUSSE, JC SCHWITZ, W BALODIS, MK PROKOFJEV, PT KRAMER, ND SIMONOVA, LI HOFF, RW GARDNER, DG GARDNER, MA GARDNER, MA CASTEN, RF GILL, RL EDER, R VONEGIDY, T HAGN, E HUNGERFORD, P SCHEERER, HJ SCHMIDT, HH MURZIN, AV LIBMAN, VA KONONENKO, IV COCEVA, C GIACOBBE, P KONDUROV, IA LOGINOV, YE SUSHKOV, PA BRANT, S PAAR, V AF KERN, J RAEMY, A BEER, W DOUSSE, JC SCHWITZ, W BALODIS, MK PROKOFJEV, PT KRAMER, ND SIMONOVA, LI HOFF, RW GARDNER, DG GARDNER, MA GARDNER, MA CASTEN, RF GILL, RL EDER, R VONEGIDY, T HAGN, E HUNGERFORD, P SCHEERER, HJ SCHMIDT, HH MURZIN, AV LIBMAN, VA KONONENKO, IV COCEVA, C GIACOBBE, P KONDUROV, IA LOGINOV, YE SUSHKOV, PA BRANT, S PAAR, V TI NUCLEAR-LEVELS IN IR-192 SO NUCLEAR PHYSICS A LA English DT Article ID CAPTURE GAMMA-RAYS; ODD-ODD NUCLEI; NEUTRON-CAPTURE; O(6) LIMIT; MODEL; STATES; AU-198; FE; SPECTROMETER; RESONANCE AB Levels in Ir-192 were studied using neutron-capture and direct-reaction spectroscopy. A pair spectrometer was used to study the high-energy gamma-ray spectrum from thermal-neutron capture in enriched IR-191 over the energy range 4640-6200 keV. From the same reaction, low-energy gamma-radiation was observed from 48 to 635 keV with semiconductor and curved-crystal spectrometers, conversion electrons were observed from 19 to 280 keV with a magnetic spectrograph and a prompt and delayed gamma-gamma-coincidence experiment was performed using semiconductor and scintillation detectors. The (n(res), gamma(high)) spectrum measurements were performed with 2 and 24 keV neutrons for primary transitions leading to excitation energies from 0 to 1160 keV. The secondary transitions following capture in three discrete resonances were observed. The spin of several parent states could thus be determined by the "population ratio" method. Using 14, 15 and 22 MeV deuterons, Ir-191(d, p) and Ir-193(d, t) high resolution spectra were observed with a magnetic spectrograph. The ground-state spin I = 4 is confirmed from the angular distribution of gamma-rays from oriented nuclei; the data favour a positive parity, in agreement with model analysis of the experimental magnetic moment and with other experimental evidence. A value of 6198.1 +/- 0.2 keV was obtained for the neutron binding energy in Ir-192. A nuclear level scheme deduced for Ir-192 includes 35 levels connected by 120 transitions. Unambiguous spins and parities were determined in a model-independent way for 14 levels, and narrow ranges of possible values were obtained for the others. Part of the results are interpreted in a qualitative way in the framework of the rotor-plus-particle model, suggesting the existence of a few rotational bands. Calculations performed in the framework of the IBFFM model are compared to the experimental results. It is suggested that the 161 keV I = 9 isomeric state has positive parity. C1 TECH UNIV MUNICH,DEPT PHYS,W-8046 GARCHING,GERMANY. ACAD SCI LASSR,INST PHYS,RIGA SALASPILS 229021,LATVIA,USSR. UNIV CALIF LAWRENCE LIVERMORE NATL LAB,LIVERMORE,CA 94550. BROOKHAVEN NATL LAB,DEPT PHYS,UPTON,NY 11973. KIEV NUCL RES INST,KIEV 252028,UKRAINE,USSR. ENTE NAZL ENERGIA ATOM,CRE E CLEMENTEL,I-40138 BOLOGNA,ITALY. ACAD SCI USSR,INST NUCL PHYS,LENINGRAD,USSR. UNIV ZAGREB,DEPT PHYS,YU-41000 ZAGREB,YUGOSLAVIA. AUSTRIAN ACAD SCI,DEPT PHYS,A-1090 VIENNA,AUSTRIA. RP KERN, J (reprint author), UNIV FRIBOURG,DEPT PHYS,CH-1700 FRIBOURG,SWITZERLAND. RI Paar, Vladimir/D-8009-2015 NR 68 TC 23 Z9 23 U1 0 U2 3 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 NOV 11 PY 1991 VL 534 IS 1 BP 77 EP 127 DI 10.1016/0375-9474(91)90559-O PG 51 WC Physics, Nuclear SC Physics GA GQ750 UT WOS:A1991GQ75000005 ER PT J AU KALLICK, DA WEMMER, DE AF KALLICK, DA WEMMER, DE TI H-1-NMR OF 5'CGCGTATATACGCG3', A DUPLEX AND A 4-MEMBERED LOOP SO NUCLEIC ACIDS RESEARCH LA English DT Article ID NUCLEAR MAGNETIC-RESONANCE; EXCHANGEABLE PROTON RESONANCES; DNA HAIRPINS; H-1-NMR SPECTRA; SPECTROSCOPY; TRANSITIONS; ASSIGNMENT; SEQUENCE; D(CGCGTTGTTCGCG); CGCGTATACGCG AB The deoxyribonucleotide 5'CGCGTATATACGCG3' was synthesized and studied by NMR methods. This short, fully palindromic duplex also forms a hairpin under certain conditions described within. As such, it is considered to be a model for cruciform formation. We show that this sequence forms a four-membered loop and a duplex in solution. The duplex is shown to be a normal, B-DNA like helix, while the hairpin is shown to be a four-membered ATAT loop. C1 UNIV CALIF BERKELEY,DEPT CHEM,BERKELEY,CA 94720. UNIV CALIF BERKELEY,LAWRENCE BERKELEY LAB,CHEM BIODYNAM LAB,BERKELEY,CA 94720. FU PHS HHS [36601] NR 27 TC 6 Z9 6 U1 0 U2 0 PU OXFORD UNIV PRESS UNITED KINGDOM PI OXFORD PA WALTON ST JOURNALS DEPT, OXFORD, ENGLAND OX2 6DP SN 0305-1048 J9 NUCLEIC ACIDS RES JI Nucleic Acids Res. PD NOV 11 PY 1991 VL 19 IS 21 BP 6041 EP 6046 DI 10.1093/nar/19.21.6041 PG 6 WC Biochemistry & Molecular Biology SC Biochemistry & Molecular Biology GA GQ238 UT WOS:A1991GQ23800033 PM 1945888 ER PT J AU BARR, SM CHANG, D SENJANOVIC, G AF BARR, SM CHANG, D SENJANOVIC, G TI STRONG CP PROBLEM AND PARITY SO PHYSICAL REVIEW LETTERS LA English DT Article ID KOBAYASHI-MASKAWA MODEL; ELECTRIC-DIPOLE MOMENT; LEFT-RIGHT SYMMETRY; INDUCED THETA-TERM; STRONG P; NATURAL SUPPRESSION; MIRROR UNIVERSE; T-INVARIANCE; VIOLATION; CHARGE AB We analyze the possibility of solving,the strong CP problem by imposing parity symmetry. simple realizations of such a scheme are given and interesting phenomenological and cosmological consequences are discussed. C1 NORTHWESTERN UNIV,DEPT PHYS & ASTRON,EVANSTON,IL 60208. FERMI NATL ACCELERATOR LAB,BATAVIA,IL 60510. UNIV ZAGREB,DEPT PHYS,YU-41001 ZAGREB,YUGOSLAVIA. RP BARR, SM (reprint author), UNIV DELAWARE,BARTOL RES INST,NEWARK,DE 19716, USA. NR 38 TC 73 Z9 73 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 NOV 11 PY 1991 VL 67 IS 20 BP 2765 EP 2768 DI 10.1103/PhysRevLett.67.2765 PG 4 WC Physics, Multidisciplinary SC Physics GA GP277 UT WOS:A1991GP27700005 ER PT J AU WALKER, FJ SPECHT, ED MCKEE, RA AF WALKER, FJ SPECHT, ED MCKEE, RA TI FILM SUBSTRATE REGISTRY AS MEASURED BY ANOMALOUS X-RAY-SCATTERING AT A REACTED, EPITAXIAL CU/SI(111) INTERFACE SO PHYSICAL REVIEW LETTERS LA English DT Article ID SURFACES; CRYSTAL; CU AB We used anomalous x-ray-diffraction methods to measure the contribution of an epitaxial copper over-layer on silicon to the crystal truncation rods (CTR's). The intensities of the CTR's are analyzed to determine interface structure; the epitaxy of a large-misfit system, Cu on Si(111), can be described in relationship to this structure. Anomalous scattering observed at the Cu K edge along a Si CTR demonstrates copper atoms to be in registry with the Si(111) surface. The copper-atom registry at the interface can be modeled based on the known bulk eta-Cu3Si structure and observed epitaxy. C1 UNIV TENNESSEE, KNOXVILLE, TN 37996 USA. RP OAK RIDGE NATL LAB, OAK RIDGE, TN 37831 USA. RI Specht, Eliot/A-5654-2009; OI Specht, Eliot/0000-0002-3191-2163; Walker, Frederick/0000-0002-8094-249X NR 19 TC 55 Z9 55 U1 0 U2 9 PU AMER PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 0031-9007 EI 1079-7114 J9 PHYS REV LETT JI Phys. Rev. Lett. PD NOV 11 PY 1991 VL 67 IS 20 BP 2818 EP 2821 DI 10.1103/PhysRevLett.67.2818 PG 4 WC Physics, Multidisciplinary SC Physics GA GP277 UT WOS:A1991GP27700019 ER PT J AU HAMALAINEN, K SIDDONS, DP HASTINGS, JB BERMAN, LE AF HAMALAINEN, K SIDDONS, DP HASTINGS, JB BERMAN, LE TI ELIMINATION OF THE INNER-SHELL LIFETIME BROADENING IN X-RAY-ABSORPTION SPECTROSCOPY SO PHYSICAL REVIEW LETTERS LA English DT Article ID RESONANT RAMAN-SCATTERING; WIDTHS AB A novel method to measure x-ray-absorption spectra without the inner-shell lifetime broadening is presented. It is based on a high-resolution spectrometer which can be used to analyze the fluorescence photon energy with better resolution than the natural linewidth. The dramatic improvement in resolution and detailed structure for the x-ray-absorption near-edge structure (XANES) at the Dy L(III) edge is presented. This new technique reveals structure which is totally invisible using conventional XANES. C1 UNIV HELSINKI,DEPT PHYS,SF-00170 HELSINKI 17,FINLAND. RP HAMALAINEN, K (reprint author), BROOKHAVEN NATL LAB,NATL SYNCHROTRON LIGHT SOURCE,UPTON,NY 11973, USA. RI Hamalainen, Keijo/A-3986-2010 OI Hamalainen, Keijo/0000-0002-9234-9810 NR 10 TC 330 Z9 331 U1 6 U2 42 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 NOV 11 PY 1991 VL 67 IS 20 BP 2850 EP 2853 DI 10.1103/PhysRevLett.67.2850 PG 4 WC Physics, Multidisciplinary SC Physics GA GP277 UT WOS:A1991GP27700027 ER PT J AU BAKER, GA AF BAKER, GA TI COLLOID THERMODYNAMICS AND ISOSPECTRAL GRAPHS SO PHYSICAL REVIEW LETTERS LA English DT Article RP BAKER, GA (reprint author), UNIV CALIF LOS ALAMOS SCI LAB,DIV THEORET,LOS ALAMOS,NM 87545, USA. NR 4 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 NOV 11 PY 1991 VL 67 IS 20 BP 2914 EP 2914 DI 10.1103/PhysRevLett.67.2914 PG 1 WC Physics, Multidisciplinary SC Physics GA GP277 UT WOS:A1991GP27700043 ER PT J AU FORDY, AP HOLM, DD AF FORDY, AP HOLM, DD TI A TRI-HAMILTONIAN FORMULATION OF THE SELF-INDUCED TRANSPARENCY EQUATIONS SO PHYSICS LETTERS A LA English DT Article ID PULSE AB We present a tri-Hamiltonian formulation of the self-induced transparency (SIT) equations. C1 UNIV LEEDS, CTR NONLINEAR STUDIES, LEEDS LS2 9JT, W YORKSHIRE, ENGLAND. UNIV CALIF LOS ALAMOS SCI LAB, DIV THEORET, LOS ALAMOS, NM 87545 USA. RP UNIV LEEDS, DEPT APPL MATH STUDIES, LEEDS LS2 9JT, W YORKSHIRE, ENGLAND. RI Fordy, Allan/K-5206-2013; OI Fordy, Allan/0000-0002-2523-0262; Holm, Darryl D/0000-0001-6362-9912 NR 13 TC 6 Z9 6 U1 0 U2 1 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0375-9601 EI 1873-2429 J9 PHYS LETT A JI Phys. Lett. A PD NOV 11 PY 1991 VL 160 IS 2 BP 143 EP 148 DI 10.1016/0375-9601(91)90603-6 PG 6 WC Physics, Multidisciplinary SC Physics GA GU466 UT WOS:A1991GU46600007 ER PT J AU BUTLER, MA PFEIFER, KB MARTIN, SJ AF BUTLER, MA PFEIFER, KB MARTIN, SJ TI 2-DIMENSIONAL PATTERNS FOR OPTICAL ALIGNMENT SO APPLIED OPTICS LA English DT Note ID BAR CODE SYSTEMS; ACCURATE ALIGNMENT; DESIGN AB Two-dimensional patterns that have properties suited for optical alignment have been constructed from one-dimensional binary Barker codes. Applications include automated alignment of masks with patterns in photolithography. RP BUTLER, MA (reprint author), SANDIA NATL LABS,MICROSENSOR DIV 1163,POB 5800,ALBUQUERQUE,NM 87185, USA. NR 4 TC 1 Z9 1 U1 0 U2 0 PU OPTICAL SOC AMER PI WASHINGTON PA 2010 MASSACHUSETTS AVE NW, WASHINGTON, DC 20036 SN 0003-6935 J9 APPL OPTICS JI Appl. Optics PD NOV 10 PY 1991 VL 30 IS 32 BP 4600 EP 4601 PG 2 WC Optics SC Optics GA GT888 UT WOS:A1991GT88800005 PM 20717256 ER PT J AU SIMPSON, ML JANSEN, JF AF SIMPSON, ML JANSEN, JF TI IMAGING COLORIMETRY - A NEW APPROACH SO APPLIED OPTICS LA English DT Article DE COLORIMETRY; IMAGING, IN-PROCESS MEASUREMENT ID IMAGES AB A new technique is described for the in-process measuring of the color content of images with pixel resolution, using commercially available devices. Color measurement is extremely important in the printing industry for assessing the quality of printed graphic images. Commercially available instruments designed to measure color, in process, have outputs that represent the average color content over specific areas of the printed surface. The color content of an image feature on the printed surface that may be important to consumers is then difficult to assess from these general readings. Instead of an average reading, the technique that we describe provides a color measurement of each pixel within the area of interest on the printing surface so that the color content of specific features can be evaluated. RP SIMPSON, ML (reprint author), OAK RIDGE NATL LAB,POB 6006,OAK RIDGE,TN 37830, USA. NR 10 TC 22 Z9 22 U1 0 U2 0 PU OPTICAL SOC AMER PI WASHINGTON PA 2010 MASSACHUSETTS AVE NW, WASHINGTON, DC 20036 SN 0003-6935 J9 APPL OPTICS JI Appl. Optics PD NOV 10 PY 1991 VL 30 IS 32 BP 4666 EP 4671 PG 6 WC Optics SC Optics GA GT888 UT WOS:A1991GT88800016 PM 20717267 ER PT J AU HECKMAN, TM LEHNERT, MD MILEY, GK VANBREUGEL, W AF HECKMAN, TM LEHNERT, MD MILEY, GK VANBREUGEL, W TI SPECTROSCOPY OF SPATIALLY EXTENDED MATERIAL AROUND HIGH-REDSHIFT RADIO-LOUD QUASARS SO ASTROPHYSICAL JOURNAL LA English DT Article DE GALAXIES, FORMATION; GALAXIES, INTERNAL MOTIONS; QUASARS ID EMISSION-LINE REGIONS; ALPHA EMISSION; COOLING FLOWS; CHEMICAL-PROPERTIES; ABSORPTION-LINES; GALAXY FORMATION; GAS; QSOS; EVOLUTION; CLUSTERS AB We present the analysis of long-slit optical spectra taken of five high-redshift (z almost-equal-to 2-3) radio-loud quasars (QSRs), selected from the imaging survey of Heckman et al. We confirm that the QSRs have Ly-alpha emission that is spatially extended by at least several tens of kiloparsecs, with a luminosity of order 10(44) ergs s-1. The gas is very active kinematically. After a subtraction of the seeing-scattered light from the broad-line region (BLR) of the central QSR, we find that line widths in the nebulae are 1000-1500 km s-1 (FWHM). The gas does not show any globally organized velocity gradients (i.e., velocities do not change by more than about 500 km s-1 over scales of tens of kiloparsecs). The line widths are close to the maximum possible for gas that is freely falling into the potential well of a very massive galaxy. Alternatively, we may be witnessing the explosive ejection of matter on a galactic scale by the QSR. The kinematic properties of the QSR nebulae are broadly similar to those of the nebulae associated with high-redshift radio galaxies. We confirm the suggestion of Foltz et al. that the nuclear He II lambda-1640 emission line in QSRs is systematically narrower than other nuclear emission lines. We find that this narrow-lined, nuclear He II emission has a strength that correlates with the strength of the spatially extended Ly-alpha emission, and suggest that the former probably arises in the inner (arcsec-scale) part of the Ly-alpha nebula. This is consistent with the fact that the velocity of the spatially extended Ly-alpha emission agrees well with the velocity of the narrow core of the nuclear Ly-alpha profile. Selecting by the presence of strong narrow He II lambda-1640 lines should be a good way to find high-z quasars with prominent Ly-alpha nebulae. We discuss the implications of these results for the nature of the z(abs) almost-equal-to z(em) systems in high-z QSRs. In three QSRs, the spatially extended Ly-alpha is redshifted by of order 10(3) km s-1 with respect to the C IV lambda-1549 BLR profile (but exhibits no significant shift in the other two QSRs). We believe that this reflects a blueshift of the C IV lines with respect to QSR systemic velocity. This has implications for the interpretation of the BLR dynamics. We have likely (4-5 sigma) detections of spatially extended He II lambda-1640 in one QSR nebulae and C IV lambda-1549 in another (each at 7%-10% of Ly-alpha). These possible detections and the upper limits on other lines are consistent with the emission-line spectra of high-z radio galaxies. Our data are not good enough either to yield strong constraints on the metallicities in the nebulae or to discriminate decisively between alternative ionization sources (photoionization by a standard active galactic nucleus continuum, photoionization by hot stars, shock heating, etc). The probable He II detector is inconsistent with predictions of photoionization models for normal high-mass stars. The probable C IV detection means that at least some galaxy-scale sites in the early universe have nonprimordial chemical abundances. The probable detections of He II and C IV make it unlikely that the bulk of the spatially extended Ly-alpha emission arises via resonant scattering of nuclear Ly-alpha photons by neutral hydrogen surrounding the QSR. C1 SPACE TELESCOPE SCI INST,BALTIMORE,MD 21218. STERREWACHT LEIDEN,2300 RA LEIDEN,NETHERLANDS. UNIV CALIF LAWRENCE LIVERMORE NATL LAB,INST GEOPHYS & PLANETARY PHYS,LIVERMORE,CA 94550. RP HECKMAN, TM (reprint author), JOHNS HOPKINS UNIV,ROWLAND DEPT PHYS & ASTRON,BALTIMORE,MD 21218, USA. NR 62 TC 79 Z9 79 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 NOV 10 PY 1991 VL 381 IS 2 BP 373 EP 385 DI 10.1086/170660 PN 1 PG 13 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA GN112 UT WOS:A1991GN11200003 ER PT J AU DAVIES, MB BENZ, W HILLS, JG AF DAVIES, MB BENZ, W HILLS, JG TI STELLAR ENCOUNTERS INVOLVING RED GIANTS IN GLOBULAR-CLUSTER CORES SO ASTROPHYSICAL JOURNAL LA English DT Article DE CLUSTERS, GLOBULAR; STARS, LATE-TYPE; STARS, STELLAR DYNAMICS ID 3-DIMENSIONAL HYDRODYNAMICAL SIMULATIONS; MAIN-SEQUENCE; WHITE-DWARFS; BINARY STARS; EVOLUTION; COLLISIONS; SUPERNOVAE AB Collisions between a 0.8 M. red giant and impactors of mass 0.4 and 0.6 M. are simulated using a three-dimensional smoothed particle hydrodynamics (SPH) code. The red giant is modeled as a massive core surrounded by a gaseous envelope, while the impactor, assumed to be a white dwarf or a main-sequence star, is treated as single particle. Encounters at various impact parameters and with relative velocities pertinent to globular clusters (10 km s-1) are studied. The effect of the encounter on the red giant depends strongly on the impact parameter. We find that if the impactor passes within twice the radius of the red giant (2R(RG)), mass loss occurs from the red giant envelope and both objects are left bound in elliptical orbits. Calculations suggest that if the impactor has an initial distance at closest approach of approximately 1.6R(RG) or less, the impactor will spiral in to the red giant envelope on subsequent periastron passages. For bound systems with a greater separation, the orbit may circularize with a radius approximately double that of the initial encounter. In both cases the system will undergo a common envelope phase: in the latter case the red giant will eventually fill its Roche lobe as it expands up the giant branch. In the case of a sufficiently small closest approach (R(min) < R(RG)), the impactor is immediately captured by the core of the red giant. Both objects form a binary system orbiting inside a common envelope formed from the original envelope of the giant. Acting like an "eggbeater," the system spins up the surrounding gas, leading to further mass loss while spiraling together. With a white drawf impactor, the likely outcome of the common envelope phase will be a tight white dwarf/white dwarf binary that will merge in less than a Hubble time. In the case of a main-sequence star impactor, a tight binary comprised of the main-sequence star and a white dwarf (the red giant core) is likely to be produced, with the main-sequence star filling its Roche lobe. C1 UNIV CALIF LOS ALAMOS SCI LAB,DIV THEORET,LOS ALAMOS,NM 87545. RP DAVIES, MB (reprint author), HARVARD SMITHSONIAN CTR ASTROPHYS,60 GARDEN ST,CAMBRIDGE,MA 02138, USA. NR 27 TC 68 Z9 68 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 NOV 10 PY 1991 VL 381 IS 2 BP 449 EP 461 DI 10.1086/170668 PN 1 PG 13 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA GN112 UT WOS:A1991GN11200011 ER PT J AU CLARK, REH ABDALLAH, J MANN, JB AF CLARK, REH ABDALLAH, J MANN, JB TI INTEGRAL AND DIFFERENTIAL CROSS-SECTIONS FOR ELECTRON-IMPACT IONIZATION SO ASTROPHYSICAL JOURNAL LA English DT Article DE ATOMIC PROCESSES; NUMERICAL METHODS ID HIGHLY CHARGED IONS; SUBLEVELS AB Calculated Coulomb-Born exchange cross sections for hydrogenic ions from 1s through 6h exist in the literature. In this paper an analytic fit formula to these cross sections has been derived by fitting simultaneously to n, l, and u where n is the principal quantum number, l is the orbital angular momentum, and u is the impact electron energy in threshold units. The resulting fit, which is easily integrated over a Maxwellian velocity distribution, reproduces the calculated cross sections to better than 10%. A prescription is given for applying the cross sections to nonhydrogenic ions. In addition, the cross sections differential with respect to the energy of the scattered electron have been fitted. RP CLARK, REH (reprint author), UNIV CALIF LOS ALAMOS SCI LAB,LOS ALAMOS,NM 87545, USA. NR 11 TC 46 Z9 46 U1 0 U2 0 PU UNIV CHICAGO PRESS PI CHICAGO PA 5720 S WOODLAWN AVE, CHICAGO, IL 60637 SN 0004-637X J9 ASTROPHYS J JI Astrophys. J. PD NOV 10 PY 1991 VL 381 IS 2 BP 597 EP 600 DI 10.1086/170685 PN 1 PG 4 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA GN112 UT WOS:A1991GN11200028 ER PT J AU COX, AN AF COX, AN TI MASSES OF RRD VARIABLES USING LIVERMORE OPAL OPACITIES SO ASTROPHYSICAL JOURNAL LA English DT Article DE OPACITIES; STARS, RR LYRAE; STARS, VARIABLES ID LYRAE STARS; MODELS; PULSATIONS; CEPHEIDS AB Twenty-seven new stellar envelope models have been constructed using the new Livermore opacities to see if the discrepancy between the masses of the double-mode RR Lyrae variables using pulsation and evolution theories can be reconciled. For these extreme Population II variables (Z = 0.0001 to 0.0004), the large opacity increases found from the extensive line absorptions of iron around 250,000 K seen in Population I compositions are not realized. If the Z is 0.001, period ratios decrease from the original Cox, Hodson, and Clancy values by more than 0.01, leading to double-mode masses more than 0.3 M. larger, but such a large Z is not reasonable for these stars. It is discovered that opacity decreases below a temperature of 10(5) K, due to more narrow lines of hydrogen than used in the Los Alamos opacities, can also decrease theoretical period ratios. This opacity decrease, as with the higher temperature increases, studied extensively before for other types of yellow giant variable stars, produces steeper temperature increases and more shallow density gradients in the regions where the pulsation eigenvectors can feel the stellar structure. This leads to longer periods for all modes, with the fundamental mode being increased in period the most. Thus it appears that period ratios should be smaller and theoretical double-mode masses about 0.1 M. larger than those using earlier opacities that were higher at lower temperatures and lower at higher temperatures. Small opacity increases at about 250,000 K can increase the more metal content RRd variables in the Oosterhoff I clusters by another 0.1 M.. This essentially eliminates the inconsistency between masses from the two globular cluster types and between those determined from pulsation and evolution theories. RP COX, AN (reprint author), UNIV CALIF LOS ALAMOS SCI LAB,DIV THEORET,POB 1663,LOS ALAMOS,NM 87545, USA. NR 28 TC 50 Z9 50 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 NOV 10 PY 1991 VL 381 IS 2 BP L71 EP L74 DI 10.1086/186199 PN 2 PG 4 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA GN115 UT WOS:A1991GN11500009 ER PT J AU GWINN, CR DANEN, RM MIDDLEDITCH, J OZERNOY, LM TRAN, TK AF GWINN, CR DANEN, RM MIDDLEDITCH, J OZERNOY, LM TRAN, TK TI THE GALACTIC-CENTER RADIO-SOURCE SHINES BELOW THE COMPTON LIMIT SO ASTROPHYSICAL JOURNAL LA English DT Article DE GALAXIES, NUCLEI; GALAXIES, THE GALAXY; INTERSTELLAR, MATTER; RADIO SOURCES, GENERAL ID REFRACTIVE INTERSTELLAR SCINTILLATION; BRIGHTNESS TEMPERATURES; A-STAR; PULSAR; SCATTERING; GALAXY; VLBI; MM AB Absence of refractive scintillation of Sgr A*, the Galactic center radio source, at 1.3 and 0.8 mm wavelengths places an observational limit of brightness temperature T(b) less-than-or-similar-to 0.5 x 10(12) K on the source. This is less than the maximum brightness of an incoherently synchrotron-emitting plasma, 10(12) K, known as the Compton limit. The refractive scintillations expected, due to strong broadening of the source by the interstellar plasma, are observed by Zhao et al. at decimeter wavelengths. We fail to observe them at 1.3 and 0.8 mm wavelengths over time spans between 0.1 s and 24 hr. Such scintillations are quenched by source size greater than about 0.1 AU, or, equivalently, T(b) < 0.5 x 10(12) K for Sgr A*, at 0.8 mm wavelength. The scintillations would also require fluctuations with scale sizes of 0.1 AU in the scattering plasma, moving across the line of sight at velocities V perpendicular-to greater-than-or-similar-to 100 km s-1. We argue that the plasma that scatters Sgr A* satisfies the latter two conditions, and that the absence of scintillations is due to the size of the source. Our observation strengthens the identification of Sgr A* as a quiescent galactic nucleus. C1 UNIV CALIF LOS ALAMOS SCI LAB,LOS ALAMOS,NM 87545. NASA,GODDARD SPACE FLIGHT CTR,HIGH ENERGY ASTROPHYS LAB,GREENBELT,MD 20771. UNIV CALIF SANTA BARBARA,COLL CREAT STUDIES,SANTA BARBARA,CA 93106. RP GWINN, CR (reprint author), UNIV CALIF SANTA BARBARA,DEPT PHYS,BROIDA HALL,SANTA BARBARA,CA 93106, USA. NR 35 TC 26 Z9 26 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 NOV 10 PY 1991 VL 381 IS 2 BP L43 EP L46 DI 10.1086/186192 PN 2 PG 4 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA GN115 UT WOS:A1991GN11500002 ER PT J AU VANRIPER, KA EPSTEIN, RI MILLER, GS AF VANRIPER, KA EPSTEIN, RI MILLER, GS TI SOFT-X-RAY PULSES FROM NEUTRON-STAR GLITCHES SO ASTROPHYSICAL JOURNAL LA English DT Article DE DENSE MATTER; STARS, EVOLUTION; STARS, INTERIORS; STARS, NEUTRON; STARS, X-RAYS ID MATTER AB Glitches release energy in the interiors of neutron stars. In some models of glitches, such as those involving the sudden transfer of angular momentum to the stellar crust from a more rapidly rotating neutron superfluid, the energy liberated is large enough (approximately 10(38)-10(43) ergs) to noticeably raise the temperature of the stellar surface. These temperature enhancements last from hours to months, depending on the stellar equation of state and the depth at which the heating occurs. We describe how measurements of the amplitudes and time scales of the temperature changes can determine the depth and the magnitude of the internal heating and set bounds on the equation of state for dense neutron star matter. These variations may be observable with the ROSAT satellite or the upcoming LANL/Berkeley soft X-ray telescope ALEXIS. RP VANRIPER, KA (reprint author), UNIV CALIF LOS ALAMOS SCI LAB,X-6,MS B226,LOS ALAMOS,NM 87544, USA. NR 18 TC 36 Z9 36 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 NOV 10 PY 1991 VL 381 IS 2 BP L47 EP L50 DI 10.1086/186193 PN 2 PG 4 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA GN115 UT WOS:A1991GN11500003 ER PT J AU MOROSIN, B VENTURINI, EL GINLEY, DS AF MOROSIN, B VENTURINI, EL GINLEY, DS TI TL-O CHARGE RESERVOIR CHANGES ON ANNEALING TL-1223 CRYSTALS SO PHYSICA C LA English DT Article ID COPPER-OXIDE SUPERCONDUCTORS; BOND-VALENCE SUMS; TRANSITION-TEMPERATURES; OXYGEN; CHEMISTRY; TC AB Two TlCa2Ba2Cu3O9-delta (Tl-1223) single crystals have been sequentially annealed in flowing oxygen or nitrogen and the complete crystal structure determined by least-squares refinement of Mo K-alpha-X-ray diffraction data. Small atomic displacements are consistent with a model in which small amounts of Tl1+ present in the Tl-O layer are reversibly oxidized to Tl3+ during mild oxygen anneals. Further, the disordered location of the Tl position off the four-fold, as determined by the usual least-squares refinement of X-ray data, appears to be related to the amount of oxygen present in the Tl-O layer in the particular crystal. Despite substantial changes in oxygen content in the Tl-O layers with annealing, Meissner data show very modest shifts in the superconducting transition temperature. T(c)'s are 117 K after extended oxygen anneals and 121 K for nitrogen anneals, suggesting little change in the carrier concentration in the Cu-O2 planes. RP MOROSIN, B (reprint author), SANDIA NATL LABS,ALBUQUERQUE,NM 87185, USA. NR 24 TC 48 Z9 48 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 NOV 10 PY 1991 VL 183 IS 1-3 BP 90 EP 98 DI 10.1016/0921-4534(91)90770-Y PG 9 WC Physics, Applied SC Physics GA GT360 UT WOS:A1991GT36000013 ER PT J AU MAO, XL BERDAHL, P RUSSO, RE LIU, HB HO, JC AF MAO, XL BERDAHL, P RUSSO, RE LIU, HB HO, JC TI BI-PB-SB-SR-CA-CU-O SUPERCONDUCTING THIN-FILMS DEPOSITED ON NI-BASED ALLOY WITH YTTRIA-STABILIZED ZIRCONIA INTERMEDIATE LAYERS SO PHYSICA C LA English DT Article ID PULSED LASER DEPOSITION; ABLATION; DEPENDENCE AB Bi-Pb-Sb-Sr-Ca-Cu-O superconducting thin films were grown as deposited using pulsed laser deposition on polycrystalline metallic alloy substrates with yttria-stabilized zirconia (YSZ) intermediate layers. YSZ intermediate layers have (111) direction perpendicular to alloy surface as determined by X-ray diffraction measurements. X-ray diffraction data show that the Bi-Pb-Sb-Sr-Ca-Cu-O films are c-axis oriented and contain primarily the 2212 phase with minor 2201 and CuO phases. Following an onset of superconducting transition above 90 K, the reproducible zero resistance temperature of these films is 62 K with J(c) of approximately 620 A/cm2 at 30 K. C1 WICHITA STATE UNIV,DEPT PHYS,WICHITA,KS 67208. WICHITA STATE UNIV,DEPT CHEM,WICHITA,KS 67208. WICHITA STATE UNIV,NATL INST AVIAT RES,WICHITA,KS 67208. RP MAO, XL (reprint author), UNIV CALIF BERKELEY,LAWRENCE BERKELEY LAB,DIV APPL SCI,BERKELEY,CA 94720, USA. NR 17 TC 4 Z9 4 U1 0 U2 1 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0921-4534 J9 PHYSICA C JI Physica C PD NOV 10 PY 1991 VL 183 IS 1-3 BP 167 EP 171 DI 10.1016/0921-4534(91)90781-S PG 5 WC Physics, Applied SC Physics GA GT360 UT WOS:A1991GT36000024 ER PT J AU HOFFMAN, GG PRATT, LR AF HOFFMAN, GG PRATT, LR TI STATISTICAL-THEORY OF ELECTRON-DENSITIES - MULTIPLE-SCATTERING PERTURBATION-THEORY SO PROCEEDINGS OF THE ROYAL SOCIETY OF LONDON SERIES A-MATHEMATICAL PHYSICAL AND ENGINEERING SCIENCES LA English DT Article ID FUNCTIONAL THEORY; PROPAGATORS AB A multiple scattering perturbation theory for electron densities, originally discussed by N. H. March and A. M. Murray, is derived in a new way. The new derivation does not depend on special choices for the origin of the energy scale. Therefore, it clarifies the point that the result of the perturbation calculation, the electron density, should be independent of the energy origin chosen for the purposes of the calculation even though the individual terms of the series do depend on that choice. This point is not evident in the previous derivations. Appreciation of this point permits adoption of an origin of the energy scale which varies with position without any change in form of the perturbation expansion. This extends the original theory beyond the significant limitation that the zero-order result is the uniform density of the free-electron gas. In particular, the energy origin can be chosen so that the zero-order contribution reproduces any physical model electron density. The theory then gives successive corrections and allows investigation of the usefulness of physical models by an analysis of the low-order corrections. These ideas permit a compact new derivation of the Thomas-Fermi theory, a derivation which also produces explicit formulae for corrections of all orders. An especially useful choice for the energy origin yields the optimized Thomas-Fermi theory as the zero-order contribution. Therefore, new results of this development are explicit formulae for the corrections to that simple theory. C1 UNIV CALIF LOS ALAMOS SCI LAB,DIV CHEM & LASER SCI,LOS ALAMOS,NM 87545. RI Pratt, Lawrence/H-7955-2012 OI Pratt, Lawrence/0000-0003-2351-7451 NR 21 TC 6 Z9 6 U1 0 U2 1 PU ROYAL SOC LONDON PI LONDON PA 6 CARLTON HOUSE TERRACE, LONDON, ENGLAND SW1Y 5AG SN 1364-5021 J9 P ROY SOC LOND A MAT JI Proc. R. Soc. London Ser. A-Math. Phys. Eng. Sci. PD NOV 8 PY 1991 VL 435 IS 1894 BP 245 EP 255 DI 10.1098/rspa.1991.0142 PG 11 WC Multidisciplinary Sciences SC Science & Technology - Other Topics GA GQ399 UT WOS:A1991GQ39900002 ER PT J AU DYKSTRA, H FLYNN, JM RANDALL, L AF DYKSTRA, H FLYNN, JM RANDALL, L TI KL-]PI-O-PI-O-GAMMA-GAMMA IN CHIRAL PERTURBATION-THEORY SO PHYSICS LETTERS B LA English DT Article ID DECAYS AB We calculate the rate and two-photon spectrum for the decay K(L) --> pi-0-pi-0-gamma-gamma using chiral perturbation theory. We comment on the implications of the study of this decay. C1 HARVARD UNIV,LYMAN LAB PHYS,CAMBRIDGE,MA 02138. MIT,CTR THEORET PHYS,NUCL SCI LAB,CAMBRIDGE,MA 02139. MIT,DEPT PHYS,CAMBRIDGE,MA 02139. RP DYKSTRA, H (reprint author), FERMI NATL ACCELERATOR LAB,BATAVIA,IL 60510, USA. NR 14 TC 6 Z9 6 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 NOV 7 PY 1991 VL 270 IS 1 BP 45 EP 50 DI 10.1016/0370-2693(91)91536-5 PG 6 WC Astronomy & Astrophysics; Physics, Nuclear; Physics, Particles & Fields SC Astronomy & Astrophysics; Physics GA GQ877 UT WOS:A1991GQ87700008 ER PT J AU ADEVA, B ADRIANI, O AGUILARBENITEZ, M AKBARI, H ALCARAZ, J ALOISIO, A ALVERSON, G ALVIGGI, MG AMBROSI, G AN, Q ANDERHUB, H ANDERSON, AL ANDREEV, VP ANGELOV, T ANTONOV, L ANTREASYAN, D ARCE, P AREFIEV, A AZEMOON, T AZIZ, T BABA, PVKS BAGNAIA, P BAKKEN, JA BAKSAY, L BALL, RC BANERJEE, S BAO, J BARILLERE, R BARONE, L BATTISTON, R BAY, A BECKER, U BEHNER, F BEHRENS, J BEINGESSNER, S BENCZE, GL BERDUGO, J BERGES, P BERTUCCI, B BETEV, BL BILAND, A BILEI, GM BIZZARRI, R BLAISING, JJ BLOMEKE, P BLUMENFELD, B BOBBINK, GJ BOCCIOLINI, M BOCK, R BOHM, A BORGIA, B BOURILKOV, D BOURQUIN, M BOUTIGNY, D BOUWENS, B BRAMBILLA, E BRANSON, JG BROCK, IC BRUYANT, F BUISSON, C BUJAK, A BURGER, JD BURQ, JP BUSENITZ, J CAI, XD CAPELL, M CARIA, M CARLINO, G CARMINATI, F CARTACCI, AM CERRADA, M CESARONI, F CHANG, YH CHATURVEDI, UK CHEMARIN, M CHEN, A CHEN, C CHEN, GM CHEN, HF CHEN, HS CHEN, M CHEN, ML CHEN, WY CHIEFARI, G CHIEN, CY CHMEISSANI, M CIVININI, C CLARE, I CLARE, R COHN, HO COIGNET, G COLINO, N COMMICHAU, V CONFORTO, G CONTIN, A CRIJNS, F CUI, XY DAI, TS DALESSANDRO, R DEASMUNDIS, R DEGRE, A DEITERS, K DENES, E DENES, P DENOTARISTEFANI, F DHINA, M DIBITONTO, D DIEMOZ, M DIMITROV, HR DIONISI, C DOVA, MT DRAGO, E DRIEVER, T DUCHESNEAU, D DUINKER, P DURAN, I ELMAMOUNI, H ENGLER, A EPPLING, FJ ERNE, FC EXTERMANN, P FABBRETTI, R FABRE, M FALCIANO, S FAN, Q FAN, SJ FACKLER, O FAY, J FERGUSON, T FERNANDEZ, G FERRONI, F FESEFELDT, H FIANDRINI, E FIELD, J FILTHAUT, F FINOCCHIARO, G FISHER, PH FORCONI, G FOREMAN, T FREUDENREICH, K FRIEBEL, W FUKUSHIMA, M GAILLOUD, M GALAKTIONOV, Y GALLO, E GANGULI, SN GARCIAABIA, P GAU, SS GELE, D GENTILE, S GLAUBMAN, M GOLDFARB, S GONG, ZF GONZALEZ, E GORDEEV, A GOTTLICHER, P GOUJON, D GRATTA, G GRINNELL, C GRUENEWALD, M GUANZIROLI, M GUO, JK GURTU, A GUSTAFSON, HR GUTAY, LJ HAAN, H HASAN, A HAUSCHILDT, D HE, CF HEBBEKER, T HEBERT, M HERTEN, G HERTEN, U HERVE, A HILGERS, K HOFER, H HOORANI, H HSU, LS HU, G HU, GQ ILLE, B ILYAS, MM INNOCENTE, V JANSSEN, H JEZEQUEL, S JIN, BN JONES, LW KASSER, A KHAN, RA KAMYSHKOV, Y KARYOTAKIS, Y KAUR, M KHOKHAR, S KHOZE, V KIENZLEFOCACCI, MN KINNISON, W KIRKBY, D KITTEL, W KLIMENTOV, A KONIG, AC KORNADT, O KOUTSENKO, V KRAEMER, RW KRAMER, T KRASTEV, VR KRENZ, W KRIZMANIC, J KUMAR, KS KUMAR, V KUNIN, A LALIEU, V LANDI, G LANIUS, K LANSKE, D LANZANO, S LEBRUN, P LECOMTE, P LECOQ, P LECOULTRE, P LEE, D LEEDOM, I LEGOFF, JM LEISTAM, L LEISTE, R LENTI, M LEONARDI, E LETTRY, J LEVCHENKO, PM LEYTENS, X LI, C LI, HT LI, JF LI, L LI, PJ LI, Q LI, XG LIAO, JY LIN, ZY LINDE, FL LINDEMANN, B LINNHOFER, D LIU, R LIU, Y LOHMANN, W LONGO, E LU, YS LUBBERS, JM LUBELSMEYER, K LUCI, C LUCKEY, D LUDOVICI, L LUMINARI, L MA, WG MACDERMOTT, M MAGAHIZ, R MALHOTRA, PK MALIK, R MALININ, A MANA, C MAO, DN MAO, YF MAOLINBAY, M MARCHESINI, P MARCHIONNI, A MARTIN, JP MARTINEZLASO, L MARZANO, F MASSARO, GGG MATSUDA, T MAZUMDAR, K MCBRIDE, P MCMAHON, T MCNALLY, D MEINHOLZ, T MERK, M MEROLA, L MESCHINI, M METZGER, WJ MI, Y MILLS, GB MIR, Y MIRABELLI, G MNICH, J MOLLER, M MONTELEONI, B MORAND, G MORAND, R MORGANTI, S MOULAI, NE MOUNT, R MULLER, S NAGY, E NAPOLITANO, M NEWMAN, H NEYER, C NIAZ, MA NIESSEN, L NOWAK, H PANDOULAS, D PAULUZZI, M PAUSS, F PLASIL, F PASSALEVA, G PATRICELLI, S PEI, YJ PERRETGALLIX, D PERRIER, J PEVSNER, A PIERI, M PIROUE, PA PLYASKIN, V POHL, M POJIDAEV, V PRODUIT, N QIAN, JM QURESHI, KN RAGHAVAN, R RAHALCALLOT, G RAVEN, G RAZIS, P READ, K REN, D REN, Z REUCROFT, S RICKER, A RIEMANN, S RIND, O RIPPICH, C RIZVI, HA ROE, BP ROHNER, M ROHNER, S ROMERO, L ROSE, J ROSIERLEES, S ROSMALEN, R ROSSELET, P RUBBIA, A RUBIO, JA RUCKSTUHL, W RYKACZEWSKI, H SACHWITZ, M SALICIO, J SALICIO, JM SANDERS, G SANTOCCHIA, A SARAKINOS, MS SARTORELLI, G SAUVAGE, G SAVIN, A SCHEGELSKY, V SCHMIEMANN, K SCHMITZ, D SCHMITZ, P SCHNEEGANS, M SCHOPPER, H SCHOTANUS, DJ SHOTKIN, S SCHREIBER, HJ SCHULTE, R SCHULTE, S SCHULTZE, K SCHUTTE, J SCHWENKE, J SCHWERING, G SCIACCA, C SCOTT, I SEHGAL, R SEILER, PG SENS, JC SERVOLI, L SHEER, I SHEN, DZ SHEVCHENKO, V SHEVCHENKO, S SHI, XR SHMAKOV, K SHOUTKO, V SHUMILOV, E SMIRNOV, N SODERSTROM, E SOPCZAK, A SPARTIOTIS, C SPICKERMANN, T SPILLANTINI, P STAROSTA, R STEUER, M STICKLAND, DP STICOZZI, F STOEFFL, W STONE, H STRAUCH, K STRINGFELLOW, BC SUDHAKAR, K SULTANOV, G SUMNER, RL SUN, LZ SUTER, H SUTTON, RB SWAIN, JD SYED, AA TANG, XW TARKOVSKY, E TAYLOR, L TIMMERMANS, C TING, SCC TING, SM TONG, YP TONISCH, F TONUTTI, M TONWAR, SC TOTH, J TROWITZSCH, G TULLY, C TUNG, KL ULBRICHT, J URBAN, L UWER, U VALENTE, E VANDEWALLE, RT VETLITSKY, I VIERTEL, G VIKAS, P VIKAS, U VIVARGENT, M VOGEL, H VOGT, H VONDARDEL, G VOROBIEV, I VOROBYOV, AA VOROBYOV, AA VUILLEUMIER, L WADHWA, M WALLRAFF, W WANG, CR WANG, GH WANG, JH WANG, QF WANG, XL WANG, YF WANG, Z WANG, ZM WEBER, A WEBER, J WEILL, R WENAUS, TJ WENNINGER, J WHITE, M WILLMOTT, C WITTGENSTEIN, F WRIGHT, D WU, RJ WU, SL WU, SX WU, YG WYSLOUCH, B XIE, YY XU, YD XU, ZZ XUE, ZL YAN, DS YAN, XJ YANG, BZ YANG, CG YANG, G YANG, KS YANG, QY YANG, ZQ YE, CH YE, JB YE, Q YEH, SC YIN, ZW YOU, JM YZERMAN, M ZACCARDELLI, C ZEMP, P ZENG, M ZENG, Y ZHANG, DH ZHANG, ZP ZHOU, JF ZHU, RY ZHUANG, HL ZICHICHI, A AF ADEVA, B ADRIANI, O AGUILARBENITEZ, M AKBARI, H ALCARAZ, J ALOISIO, A ALVERSON, G ALVIGGI, MG AMBROSI, G AN, Q ANDERHUB, H ANDERSON, AL ANDREEV, VP ANGELOV, T ANTONOV, L ANTREASYAN, D ARCE, P AREFIEV, A AZEMOON, T AZIZ, T BABA, PVKS BAGNAIA, P BAKKEN, JA BAKSAY, L BALL, RC BANERJEE, S BAO, J BARILLERE, R BARONE, L BATTISTON, R BAY, A BECKER, U BEHNER, F BEHRENS, J BEINGESSNER, S BENCZE, GL BERDUGO, J BERGES, P BERTUCCI, B BETEV, BL BILAND, A BILEI, GM BIZZARRI, R BLAISING, JJ BLOMEKE, P BLUMENFELD, B BOBBINK, GJ BOCCIOLINI, M BOCK, R BOHM, A BORGIA, B BOURILKOV, D BOURQUIN, M BOUTIGNY, D BOUWENS, B BRAMBILLA, E BRANSON, JG BROCK, IC BRUYANT, F BUISSON, C BUJAK, A BURGER, JD BURQ, JP BUSENITZ, J CAI, XD CAPELL, M CARIA, M CARLINO, G CARMINATI, F CARTACCI, AM CERRADA, M CESARONI, F CHANG, YH CHATURVEDI, UK CHEMARIN, M CHEN, A CHEN, C CHEN, GM CHEN, HF CHEN, HS CHEN, M CHEN, ML CHEN, WY CHIEFARI, G CHIEN, CY CHMEISSANI, M CIVININI, C CLARE, I CLARE, R COHN, HO COIGNET, G COLINO, N COMMICHAU, V CONFORTO, G CONTIN, A CRIJNS, F CUI, XY DAI, TS DALESSANDRO, R DEASMUNDIS, R DEGRE, A DEITERS, K DENES, E DENES, P DENOTARISTEFANI, F DHINA, M DIBITONTO, D DIEMOZ, M DIMITROV, HR DIONISI, C DOVA, MT DRAGO, E DRIEVER, T DUCHESNEAU, D DUINKER, P DURAN, I ELMAMOUNI, H ENGLER, A EPPLING, FJ ERNE, FC EXTERMANN, P FABBRETTI, R FABRE, M FALCIANO, S FAN, Q FAN, SJ FACKLER, O FAY, J FERGUSON, T FERNANDEZ, G FERRONI, F FESEFELDT, H FIANDRINI, E FIELD, J FILTHAUT, F FINOCCHIARO, G FISHER, PH FORCONI, G FOREMAN, T FREUDENREICH, K FRIEBEL, W FUKUSHIMA, M GAILLOUD, M GALAKTIONOV, Y GALLO, E GANGULI, SN GARCIAABIA, P GAU, SS GELE, D GENTILE, S GLAUBMAN, M GOLDFARB, S GONG, ZF GONZALEZ, E GORDEEV, A GOTTLICHER, P GOUJON, D GRATTA, G GRINNELL, C GRUENEWALD, M GUANZIROLI, M GUO, JK GURTU, A GUSTAFSON, HR GUTAY, LJ HAAN, H HASAN, A HAUSCHILDT, D HE, CF HEBBEKER, T HEBERT, M HERTEN, G HERTEN, U HERVE, A HILGERS, K HOFER, H HOORANI, H HSU, LS HU, G HU, GQ ILLE, B ILYAS, MM INNOCENTE, V JANSSEN, H JEZEQUEL, S JIN, BN JONES, LW KASSER, A KHAN, RA KAMYSHKOV, Y KARYOTAKIS, Y KAUR, M KHOKHAR, S KHOZE, V KIENZLEFOCACCI, MN KINNISON, W KIRKBY, D KITTEL, W KLIMENTOV, A KONIG, AC KORNADT, O KOUTSENKO, V KRAEMER, RW KRAMER, T KRASTEV, VR KRENZ, W KRIZMANIC, J KUMAR, KS KUMAR, V KUNIN, A LALIEU, V LANDI, G LANIUS, K LANSKE, D LANZANO, S LEBRUN, P LECOMTE, P LECOQ, P LECOULTRE, P LEE, D LEEDOM, I LEGOFF, JM LEISTAM, L LEISTE, R LENTI, M LEONARDI, E LETTRY, J LEVCHENKO, PM LEYTENS, X LI, C LI, HT LI, JF LI, L LI, PJ LI, Q LI, XG LIAO, JY LIN, ZY LINDE, FL LINDEMANN, B LINNHOFER, D LIU, R LIU, Y LOHMANN, W LONGO, E LU, YS LUBBERS, JM LUBELSMEYER, K LUCI, C LUCKEY, D LUDOVICI, L LUMINARI, L MA, WG MACDERMOTT, M MAGAHIZ, R MALHOTRA, PK MALIK, R MALININ, A MANA, C MAO, DN MAO, YF MAOLINBAY, M MARCHESINI, P MARCHIONNI, A MARTIN, JP MARTINEZLASO, L MARZANO, F MASSARO, GGG MATSUDA, T MAZUMDAR, K MCBRIDE, P MCMAHON, T MCNALLY, D MEINHOLZ, T MERK, M MEROLA, L MESCHINI, M METZGER, WJ MI, Y MILLS, GB MIR, Y MIRABELLI, G MNICH, J MOLLER, M MONTELEONI, B MORAND, G MORAND, R MORGANTI, S MOULAI, NE MOUNT, R MULLER, S NAGY, E NAPOLITANO, M NEWMAN, H NEYER, C NIAZ, MA NIESSEN, L NOWAK, H PANDOULAS, D PAULUZZI, M PAUSS, F PLASIL, F PASSALEVA, G PATRICELLI, S PEI, YJ PERRETGALLIX, D PERRIER, J PEVSNER, A PIERI, M PIROUE, PA PLYASKIN, V POHL, M POJIDAEV, V PRODUIT, N QIAN, JM QURESHI, KN RAGHAVAN, R RAHALCALLOT, G RAVEN, G RAZIS, P READ, K REN, D REN, Z REUCROFT, S RICKER, A RIEMANN, S RIND, O RIPPICH, C RIZVI, HA ROE, BP ROHNER, M ROHNER, S ROMERO, L ROSE, J ROSIERLEES, S ROSMALEN, R ROSSELET, P RUBBIA, A RUBIO, JA RUCKSTUHL, W RYKACZEWSKI, H SACHWITZ, M SALICIO, J SALICIO, JM SANDERS, G SANTOCCHIA, A SARAKINOS, MS SARTORELLI, G SAUVAGE, G SAVIN, A SCHEGELSKY, V SCHMIEMANN, K SCHMITZ, D SCHMITZ, P SCHNEEGANS, M SCHOPPER, H SCHOTANUS, DJ SHOTKIN, S SCHREIBER, HJ SCHULTE, R SCHULTE, S SCHULTZE, K SCHUTTE, J SCHWENKE, J SCHWERING, G SCIACCA, C SCOTT, I SEHGAL, R SEILER, PG SENS, JC SERVOLI, L SHEER, I SHEN, DZ SHEVCHENKO, V SHEVCHENKO, S SHI, XR SHMAKOV, K SHOUTKO, V SHUMILOV, E SMIRNOV, N SODERSTROM, E SOPCZAK, A SPARTIOTIS, C SPICKERMANN, T SPILLANTINI, P STAROSTA, R STEUER, M STICKLAND, DP STICOZZI, F STOEFFL, W STONE, H STRAUCH, K STRINGFELLOW, BC SUDHAKAR, K SULTANOV, G SUMNER, RL SUN, LZ SUTER, H SUTTON, RB SWAIN, JD SYED, AA TANG, XW TARKOVSKY, E TAYLOR, L TIMMERMANS, C TING, SCC TING, SM TONG, YP TONISCH, F TONUTTI, M TONWAR, SC TOTH, J TROWITZSCH, G TULLY, C TUNG, KL ULBRICHT, J URBAN, L UWER, U VALENTE, E VANDEWALLE, RT VETLITSKY, I VIERTEL, G VIKAS, P VIKAS, U VIVARGENT, M VOGEL, H VOGT, H VONDARDEL, G VOROBIEV, I VOROBYOV, AA VOROBYOV, AA VUILLEUMIER, L WADHWA, M WALLRAFF, W WANG, CR WANG, GH WANG, JH WANG, QF WANG, XL WANG, YF WANG, Z WANG, ZM WEBER, A WEBER, J WEILL, R WENAUS, TJ WENNINGER, J WHITE, M WILLMOTT, C WITTGENSTEIN, F WRIGHT, D WU, RJ WU, SL WU, SX WU, YG WYSLOUCH, B XIE, YY XU, YD XU, ZZ XUE, ZL YAN, DS YAN, XJ YANG, BZ YANG, CG YANG, G YANG, KS YANG, QY YANG, ZQ YE, CH YE, JB YE, Q YEH, SC YIN, ZW YOU, JM YZERMAN, M ZACCARDELLI, C ZEMP, P ZENG, M ZENG, Y ZHANG, DH ZHANG, ZP ZHOU, JF ZHU, RY ZHUANG, HL ZICHICHI, A TI MEASUREMENT OF THE LIFETIME OF B-HADRONS AND A DETERMINATION OF [VCB] SO PHYSICS LETTERS B LA English DT Article ID AVERAGE LIFETIME; BOTTOM HADRONS; E+E ANNIHILATION; DECAYS; QUARKS; FRAGMENTATION; UPDATE AB From a fit to the impact parameter distribution of lepton tracks from semileptonic b decay, the lifetime of B-hadrons produced in e+e- collisions at the Z0 is measured to be 1.32 +/- 0.08 (stat.) +/- 0.09 (syst.) ps. Combined with an earlier measurement of the branching ratio Br(B --> lvX), the CKM matrix element \V(cb)\ is determined to be 0.046 +/- 0.002 (exp.) -0.003(+0.004) (theory). C1 IST NAZL FIS NUCL,I-50125 FLORENCE,ITALY. UNIV FLORENCE,I-50125 FLORENCE,ITALY. CTR INVEST ENERGET MED & TECNOL,E-28040 MADRID,SPAIN. JOHNS HOPKINS UNIV,BALTIMORE,MD 21218. IST NAZL FIS NUCL,I-80125 NAPLES,ITALY. NAPLES UNIV,I-80125 NAPLES,ITALY. NORTHEASTERN UNIV,BOSTON,MA 02115. IST NAZL FIS NUCL,I-06100 PERUGIA,ITALY. UNIV PERUGIA,I-06100 PERUGIA,ITALY. WORLD LAB,FBLJA PROJECT,CH-1211 GENEVA,SWITZERLAND. SWISS FED INST TECHNOL,CH-8093 ZURICH,SWITZERLAND. MIT,CAMBRIDGE,MA 02139. LENINGRAD NUCL PHYS INST,GATCHINA 188350,USSR. CLANP,CENT LAB AUTOMAT & INSTRUMENTAT,SOFIA,BULGARIA. UNIV BOLOGNA,I-40126 BOLOGNA,ITALY. IST NAZL FIS NUCL,I-40126 BOLOGNA,ITALY. MOSCOW THEORET & EXPTL PHYS INST,MOSCOW 117259,USSR. UNIV MICHIGAN,ANN ARBOR,MI 48109. TATA INST FUNDAMENTAL RES,BOMBAY 400005,INDIA. IST NAZL FIS NUCL,I-00185 ROME,ITALY. UNIV ROME LA SAPIENZA,I-00185 ROME,ITALY. PRINCETON UNIV,PRINCETON,NJ 08544. UNIV ALABAMA,TUSCALOOSA,AL 35486. UNIV GENEVA,CH-1211 GENEVA 4,SWITZERLAND. LAB PHYS PARTICLES,F-74519 ANNECY LE VIEUX,FRANCE. HUNGARIAN ACAD SCI,CENT RES INST PHYS,H-1525 BUDAPEST 114,HUNGARY. RHEIN WESTFAL TH AACHEN,INST PHYS 1,W-5100 AACHEN,GERMANY. RHEIN WESTFAL TH AACHEN,INST PHYS 2,W-5100 AACHEN,GERMANY. NATL INST HIGH ENERGY PHYS,1009 DB AMSTERDAM,NETHERLANDS. UNIV CALIF SAN DIEGO,SAN DIEGO,CA 92182. CARNEGIE MELLON UNIV,PITTSBURGH,PA 15213. UNIV LYON 1,INST PHYS NUCL LYON,CNRS,IN2P3,F-69622 VILLEURBANNE,FRANCE. PURDUE UNIV,W LAFAYETTE,IN 47907. UNIV CALIF LAWRENCE LIVERMORE NATL LAB,LIVERMORE,CA 94550. INST HIGH ENERGY PHYS,BEIJING,PEOPLES R CHINA. UNIV SCI & TECHNOL,HEFEI 230029,PEOPLES R CHINA. OAK RIDGE NATL LAB,OAK RIDGE,TN 37830. CATHOLIC UNIV NIJMEGEN,6525 ED NIJMEGEN,NETHERLANDS. NIKHEF NIJMEGEN,6525 ED NIJMEGEN,NETHERLANDS. PAUL SCHERRER INST,WURENLINGEN,SWITZERLAND. SHANGHAI INST CERAM,SHANGHAI,PEOPLES R CHINA. INST HOCHENERGIEPHYS,W-1615 ZEUTHEN BERLIN,GERMANY. UNIV LAUSANNE,CH-1015 LAUSANNE,SWITZERLAND. CALTECH,PASADENA,CA 91125. UNIV CALIF LOS ALAMOS SCI LAB,LOS ALAMOS,NM 87544. HARVARD UNIV,CAMBRIDGE,MA 02139. UNION UNIV UNION COLL,SCHENECTADY,NY 12308. UNIV HAMBURG,W-2000 HAMBURG 13,GERMANY. RP ADEVA, B (reprint author), CERN,EUROPEAN LAB PARTICLE PHYS,CH-1211 GENEVA 23,SWITZERLAND. RI Fiandrini, Emanuele/C-4549-2008; Leijtens, Xaveer/F-3302-2010; Ludovici, Lucio/F-5917-2011; Servoli, Leonello/E-6766-2012; bertucci, bruna/J-5237-2012; Cerrada, Marcos/J-6934-2014; Gonzalez Romero, Enrique/L-7561-2014; Vogel, Helmut/N-8882-2014; Ferguson, Thomas/O-3444-2014; Berdugo, Javier/A-2858-2015; D'Alessandro, Raffaello/F-5897-2015; Chmeissani, Mokhtar/G-4346-2015; Duran, Ignacio/H-7254-2015; Adeva, Bernardo /L-1378-2014; Hoorani, Hafeez/D-1791-2013; Arce, Pedro/L-1268-2014; Kamyshkov, Yuri/J-7999-2016; OI Leijtens, Xaveer/0000-0001-7794-8236; Ludovici, Lucio/0000-0003-1970-9960; Servoli, Leonello/0000-0003-1725-9185; Cerrada, Marcos/0000-0003-0112-1691; Gonzalez Romero, Enrique/0000-0003-2376-8920; Vogel, Helmut/0000-0002-6109-3023; Ferguson, Thomas/0000-0001-5822-3731; Berdugo, Javier/0000-0002-7911-8532; D'Alessandro, Raffaello/0000-0001-7997-0306; Chmeissani, Mokhtar/0000-0002-2287-4791; Adeva, Bernardo /0000-0001-9756-3712; Arce, Pedro/0000-0003-3009-0484; Kamyshkov, Yuri/0000-0002-3789-7152; Longo, Egidio/0000-0001-6238-6787; Levchenko, Petr/0000-0003-4913-0538; Diemoz, Marcella/0000-0002-3810-8530; Bertucci, Bruna/0000-0001-7584-293X; Filthaut, Frank/0000-0003-3338-2247 NR 45 TC 22 Z9 22 U1 1 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 NOV 7 PY 1991 VL 270 IS 1 BP 111 EP 122 DI 10.1016/0370-2693(91)91547-9 PG 12 WC Astronomy & Astrophysics; Physics, Nuclear; Physics, Particles & Fields SC Astronomy & Astrophysics; Physics GA GQ877 UT WOS:A1991GQ87700019 ER PT J AU DUBOIS, DL MIEDANER, A HALTIWANGER, RC AF DUBOIS, DL MIEDANER, A HALTIWANGER, RC TI ELECTROCHEMICAL REDUCTION OF CO2 CATALYZED BY [PD(TRIPHOSPHINE)(SOLVENT)](BF4)2 COMPLEXES - SYNTHETIC AND MECHANISTIC STUDIES SO JOURNAL OF THE AMERICAN CHEMICAL SOCIETY LA English DT Article ID CARBON-DIOXIDE REDUCTION; ELECTROCATALYTIC REDUCTION; PHOSPHINE-LIGANDS; METAL CATIONS; NICKEL; PLATINUM(I); CONSTANTS; COBALT(I); BINDING; CRYSTAL AB The free radical addition of phosphorus-hydrogen bonds to carbon-carbon double bonds has been used to prepare a number of new tridentate ligands containing phosphorus. Reactions of these tridentate ligands with [Pd(CH3CN)4](BF4)2 yield the corresponding [Pd(tridentate)(CH3CN)](BF4)2 complexes. These complexes catalyze the electrochemical reduction of CO2 to CO in acidic dimethylformamide or acetonitrile solutions if the tridentate ligand is a linear triphosphine ligand. Complexes in which one or more of the phosphorus atoms of the tridentate ligand have been substituted with a nitrogen or sulfur heteroatom do not catalyze the electrochemical reduction of C02. Kinetic studies on [Pd(etpC)(CH3CN)](BPh4)2 (where etpC is bis[(dicyclohexylphosphino)ethyl]phenylphosphine) show that, at acid concentrations above 1.0 X 10(-2) M, the reaction is first order in catalyst, first order in CO2, and independent of acid concentration. At acid concentrations less than 4.0 X 10(-3) M, the catalytic rate is first order in catalyst, second order in acid, and independent of CO2. The rate is also solvent dependent. A mechanism is proposed to account for these data. Comparison of the rate constants for catalysts with different alkyl and aryl substituents on the terminal phosphorus atoms indicates that the rate of reaction of the palladium(I) intermediates with CO2 increases with the electron-donating ability of the R groups, and that steric interactions are of less importance. In contrast, the rate constants decrease with increasing steric bulk for substituents on the central phosphorus atoms of the triphosphine ligand. Other relationships between ligand structure and catalyst activity, selectivity, and stability are also discussed. An X-ray diffraction study of the catalytic decomposition product [Pd(etp)]2(BF4)2 (where etp is bis[(diphenylphosphino)-ethyl] phenylphosphine) has been carried out. [Pd(etP)]2(BF4)2 crystallizes in the monoclinic space group P2(1)/n with a = 13.842 (6) angstrom, b = 28.055 (8) angstrom, c = 19.596 (7) angstrom, beta = 95.80 (3)degrees, upsilon = 7571 (5) angstrom3, and Z = 4. The structure was refined to R = 0.057 and R(w) = 0.0809 for 10 352 independent reflections (F > 6-sigma(F)). This Pd(I) dimer is bridged by two triphosphine ligands. A dihedral angle of 67-degrees exists between the two nearly square planar PdP3 fragments of [Pd(etP)]2(BF4)2. This dimer can be reoxidized to regenerate the catalytically active complexes. C1 UNIV COLORADO,DEPT CHEM & BIOCHEM,BOULDER,CO 80309. RP DUBOIS, DL (reprint author), SOLAR ENERGY RES INST,GOLDEN,CO 80401, USA. NR 65 TC 108 Z9 108 U1 8 U2 58 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 NOV 6 PY 1991 VL 113 IS 23 BP 8753 EP 8764 DI 10.1021/ja00023a023 PG 12 WC Chemistry, Multidisciplinary SC Chemistry GA GP037 UT WOS:A1991GP03700023 ER PT J AU SALVADORI, MC AGER, JW BROWN, IG KRISHNAN, KM AF SALVADORI, MC AGER, JW BROWN, IG KRISHNAN, KM TI DIAMOND SYNTHESIS BY MICROWAVE PLASMA CHEMICAL VAPOR-DEPOSITION USING GRAPHITE AS THE CARBON SOURCE SO APPLIED PHYSICS LETTERS LA English DT Article ID GROWTH AB We report on the growth of high-quality diamond using a microwave plasma chemical vapor deposition (CVD) system in which the feed gas contains no hydrocarbons, but instead the source of carbon is a graphite piece which resides within the plasma volume. Results of experiments using this technique by itself and in combination with the normal methane feed gas method are described. The samples were analyzed by Raman spectroscopy and scanning electron microscopy. Diamond grown in this way was found to be particularly pure and of high crystallinity. C1 UNIV CALIF BERKELEY,LAWRENCE BERKELEY LAB,DIV ACCELERATOR & FUS RES,BERKELEY,CA 94720. UNIV CALIF BERKELEY,LAWRENCE BERKELEY LAB,DIV MAT SCI,BERKELEY,CA 94720. RI Salvadori, Maria Cecilia/A-9379-2013; OI Ager, Joel/0000-0001-9334-9751 NR 7 TC 26 Z9 26 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 NOV 4 PY 1991 VL 59 IS 19 BP 2386 EP 2388 DI 10.1063/1.106024 PG 3 WC Physics, Applied SC Physics GA GM782 UT WOS:A1991GM78200013 ER PT J AU DUNKER, AK ENSIGN, LD ARNOLD, GE ROBERTS, LM AF DUNKER, AK ENSIGN, LD ARNOLD, GE ROBERTS, LM TI A MODEL FOR FD PHAGE PENETRATION AND ASSEMBLY SO FEBS LETTERS LA English DT Article DE FILAMENTOUS PHAGE ASSEMBLY ID COAT PROTEIN; CONFORMATIONAL CHANGE; BACTERIOPHAGE-FD; SPECTROSCOPY; ORIENTATION; MECHANISM; DYNAMICS; M13 AB Below 15-degrees-C, chloroform causes fd phage to contract to I-forms, which are compact structures about 1/3 as long as the original phage. Above 15-degrees-C, chloroform causes I-forms to contract to even more compact spheroidal S-forms. Here we show that the coat protein structure in I-forms is the same as the protein structure in the phage and the protein structure in S-forms is the same as the protein structure in bilayers. The conversions from fd --> I-forms --> S-forms are therefore suggested to mimic steps in fd penetration. The same conversions, in reverse order, are suggested to mimic steps in fd assembly. C1 PACIFIC NW LAB, MOLEC SCI RES CTR, RICHLAND, WA 99352 USA. SO RES INST, BIRMINGHAM, AL 35205 USA. RP DUNKER, AK (reprint author), WASHINGTON STATE UNIV, DEPT BIOCHEM & BIOPHYS, PULLMAN, WA 99164 USA. NR 31 TC 28 Z9 28 U1 0 U2 1 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0014-5793 J9 FEBS LETT JI FEBS Lett. PD NOV 4 PY 1991 VL 292 IS 1-2 BP 271 EP 274 DI 10.1016/0014-5793(91)80882-4 PG 4 WC Biochemistry & Molecular Biology; Biophysics; Cell Biology SC Biochemistry & Molecular Biology; Biophysics; Cell Biology GA GQ995 UT WOS:A1991GQ99500064 PM 1959617 ER PT J AU DUNKER, AK ENSIGN, LD ARNOLD, GE ROBERTS, LM AF DUNKER, AK ENSIGN, LD ARNOLD, GE ROBERTS, LM TI PROPOSED MOLTEN GLOBULE INTERMEDIATES IN FD PHAGE PENETRATION AND ASSEMBLY SO FEBS LETTERS LA English DT Article DE FILAMENTOUS PHAGE ASSEMBLY; MOLTEN GLOBULE INTERMEDIATE ID COAT PROTEIN; STATE; BACTERIOPHAGE-F1; ORIENTATION AB The fd filamentous phage can be contracted to short rods called I-forms and to spheroidal particles called S-forms. The conversions from fd-->I-forms-->S-forms were previously suggested to mimic steps in fd penetration. The same conversions, in reverse order, were suggested to mimic steps in fd assembly. The I-forms and S-forms bind the hydrophobic probe, 1-anilino-napthalene-8-sulfonate (ANS); under the same conditions, fd binds this probe very poorly. Rigidly packed side chains in fd and nonrigidly packed side chains in I-forms and S-forms would explain the differences in ANS binding. A compilation of the properties of I-forms and S-forms indicate that: (i) they have compact structures; (ii) they have secondary structures of the same type as native phage; (iii) they have non-native morphologies; and (iv) they may have nonrigid side chain packing. These are the properties of molten globules. C1 PACIFIC NW LAB, MOLEC SCI RES CTR, RICHLAND, WA 99352 USA. SO RES INST, BIRMINGHAM, AL 35205 USA. RP DUNKER, AK (reprint author), WASHINGTON STATE UNIV, DEPT BIOCHEM & BIOPHYS, PULLMAN, WA 99164 USA. NR 20 TC 27 Z9 27 U1 0 U2 2 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0014-5793 J9 FEBS LETT JI FEBS Lett. PD NOV 4 PY 1991 VL 292 IS 1-2 BP 275 EP 278 DI 10.1016/0014-5793(91)80883-5 PG 4 WC Biochemistry & Molecular Biology; Biophysics; Cell Biology SC Biochemistry & Molecular Biology; Biophysics; Cell Biology GA GQ995 UT WOS:A1991GQ99500065 PM 1959618 ER PT J AU GNEHM, E HELLAND, GA AF GNEHM, E HELLAND, GA TI WELL CONTROL IN KUWAIT SO OIL & GAS JOURNAL LA English DT Letter C1 US DOE,WASHINGTON,DC 20585. NR 0 TC 0 Z9 0 U1 0 U2 0 PU PENNWELL PUBL CO ENERGY GROUP PI TULSA PA 1421 S SHERIDAN RD PO BOX 1260, TULSA, OK 74101 SN 0030-1388 J9 OIL GAS J JI Oil Gas J. PD NOV 4 PY 1991 VL 89 IS 44 BP 8 EP 9 PG 2 WC Energy & Fuels; Engineering, Petroleum SC Energy & Fuels; Engineering GA GN349 UT WOS:A1991GN34900001 ER PT J AU ABE, F AMIDEI, D APOLLINARI, G ATAC, M AUCHINCLOSS, P BADEN, AR BACCHETTA, N BAILEY, MW BAMBERGER, A BARNETT, BA BARBAROGALTIERI, A BARNES, VE BAUMANN, T BEDESCHI, F BEHRENDS, S BELFORTE, S BELLETTINI, G BELLINGER, J BENSINGER, J BERETVAS, A BERGE, JP BERTOLUCCI, S BHADRA, S BINKLEY, M BLAIR, R BLOCKER, C BOLOGNESI, V BOOTH, AW BOSWELL, C BRANDENBURG, G BROWN, D BUCKLEYGEER, E BUDD, HS BUSETTO, G BYONWAGNER, A BYRUM, KL CAMPAGNARI, C CAMPBELL, M CAREY, R CARITHERS, W CARLSMITH, D CARROLL, JT CASHMORE, R CASTRO, A CERVELLI, F CHADWICK, K CHIARELLI, G CHINOWSKY, W CIHANGIR, S CLARK, AG CONNOR, D CONTRERAS, M COOPER, J CORDELLI, M CRANE, D CURATOLO, M DAY, C DEJONGH, F DELLAGNELLO, S DELLORSO, M DEMORTIER, L DENBY, B DERWENT, PF DEVLIN, T DIBITONTO, D DRUCKER, RB EDNER, S ELIAS, JE ELY, R ENO, S ERREDE, S ESPOSITO, B FLAUGHER, B FOSTER, GW FRANKLIN, M FREEMAN, J FRISCH, H FUESS, T FUKUI, Y FUNAYAMA, Y GARFINKEL, AF GAUTHIER, A GEER, S GERDES, DW GIANNETTI, P GIOKARIS, N GIROMINI, P GLADNEY, L GOLD, M GOULIANOS, K GRASSMANN, H GROSSOPILCHER, C HABER, C HAHN, SR HANDLER, R HARA, K HARRIS, RM HAUSER, J HAWK, C HESSING, T HOLLEBEEK, R HOLLOWAY, L HU, P HUBBARD, B HUFFMAN, BT HUGHES, R HURST, P HUTH, J INCAGLI, M INO, T ISO, H JENSEN, H JESSOP, CP JOHNSON, RP JOSHI, U KADEL, RW KAMON, T KANDA, S KARDELIS, DA KARLINER, I KEARNS, E KEEBLE, L KEPHART, R KESTEN, P KEUP, RM KEUTELIAN, H KIM, D KIM, S KIRSCH, L KONDO, K KONIGSBERG, J KOVACS, E KUHLMANN, SE KUNS, E LAASANEN, AT LAMOUREUX, JI LEONE, S LI, W LISS, TM LOCKYER, N LUCHINI, CB LUKENS, P MAAS, P MANGANO, M MARRINER, JP MARIOTTI, M MARKELOFF, R MARKOSKY, LA MATTINGLY, R MCINTYRE, P MENZIONE, A MEYER, T MIKAMO, S MILLER, M MIMASHI, T MISCETTI, S MISHINA, M MIYASHITA, S MORITA, Y MOULDING, S MUELLER, J MUKHERJEE, A NAKAE, LF NAKANO, I NELSON, C NEWMANHOLMES, C NG, JST NINOMIYA, M NODULMAN, L OGAWA, S PAOLETTI, R PARA, A PARE, E PATRICK, J PHILLIPS, TJ PLUNKETT, R PONDROM, L PROUDFOOT, J PUNZI, G QUARRIE, D RAGAN, K REDLINGER, G RHOADES, J ROACH, M RIMONDI, F RISTORI, L ROHALY, T ROODMAN, A SAKUMOTO, WK SANSONI, A SARD, RD SAVOYNAVARRO, A SCARPINE, V SCHLABACH, P SCHMIDT, EE SCHUB, MH SCHWITTERS, R SCRIBANO, A SEGLER, S SEIYA, Y SEKIGUCHI, M SHAPIRO, M SHAW, NM SHEAFF, M SHOCHET, M SIEGRIST, J SINERVO, P SKARHA, J SLIWA, K SMITH, DA SNIDER, FD SONG, L STDENIS, R STEFANINI, A SULLIVAN, G SWARTZ, RL TAKANO, M TARTARELLI, F TAKIKAWA, K TAREM, S THERIOT, D TIMKO, M TIPTON, P TKACZYK, S TOLLESTRUP, A TONNISON, J TRISCHUK, W TURINI, N TSAY, Y UKEGAWA, F UNDERWOOD, D VEJCIK, S VIDAL, R WAGNER, RG WAGNER, RL WAINER, N WALSH, J WATTS, T WEBB, R WENDT, C WENZEL, H WESTER, WC WESTHUSING, T WHITE, SN WICKLUND, AB WILLIAMS, HH WINER, BL WYSS, J YAGIL, A YAMASHITA, A YASUOKA, K YEH, GP YOH, J YOKOYAMA, M YUN, JC ZANETTI, A ZETTI, F ZUCCHELLI, S AF ABE, F AMIDEI, D APOLLINARI, G ATAC, M AUCHINCLOSS, P BADEN, AR BACCHETTA, N BAILEY, MW BAMBERGER, A BARNETT, BA BARBAROGALTIERI, A BARNES, VE BAUMANN, T BEDESCHI, F BEHRENDS, S BELFORTE, S BELLETTINI, G BELLINGER, J BENSINGER, J BERETVAS, A BERGE, JP BERTOLUCCI, S BHADRA, S BINKLEY, M BLAIR, R BLOCKER, C BOLOGNESI, V BOOTH, AW BOSWELL, C BRANDENBURG, G BROWN, D BUCKLEYGEER, E BUDD, HS BUSETTO, G BYONWAGNER, A BYRUM, KL CAMPAGNARI, C CAMPBELL, M CAREY, R CARITHERS, W CARLSMITH, D CARROLL, JT CASHMORE, R CASTRO, A CERVELLI, F CHADWICK, K CHIARELLI, G CHINOWSKY, W CIHANGIR, S CLARK, AG CONNOR, D CONTRERAS, M COOPER, J CORDELLI, M CRANE, D CURATOLO, M DAY, C DEJONGH, F DELLAGNELLO, S DELLORSO, M DEMORTIER, L DENBY, B DERWENT, PF DEVLIN, T DIBITONTO, D DRUCKER, RB EDNER, S ELIAS, JE ELY, R ENO, S ERREDE, S ESPOSITO, B FLAUGHER, B FOSTER, GW FRANKLIN, M FREEMAN, J FRISCH, H FUESS, T FUKUI, Y FUNAYAMA, Y GARFINKEL, AF GAUTHIER, A GEER, S GERDES, DW GIANNETTI, P GIOKARIS, N GIROMINI, P GLADNEY, L GOLD, M GOULIANOS, K GRASSMANN, H GROSSOPILCHER, C HABER, C HAHN, SR HANDLER, R HARA, K HARRIS, RM HAUSER, J HAWK, C HESSING, T HOLLEBEEK, R HOLLOWAY, L HU, P HUBBARD, B HUFFMAN, BT HUGHES, R HURST, P HUTH, J INCAGLI, M INO, T ISO, H JENSEN, H JESSOP, CP JOHNSON, RP JOSHI, U KADEL, RW KAMON, T KANDA, S KARDELIS, DA KARLINER, I KEARNS, E KEEBLE, L KEPHART, R KESTEN, P KEUP, RM KEUTELIAN, H KIM, D KIM, S KIRSCH, L KONDO, K KONIGSBERG, J KOVACS, E KUHLMANN, SE KUNS, E LAASANEN, AT LAMOUREUX, JI LEONE, S LI, W LISS, TM LOCKYER, N LUCHINI, CB LUKENS, P MAAS, P MANGANO, M MARRINER, JP MARIOTTI, M MARKELOFF, R MARKOSKY, LA MATTINGLY, R MCINTYRE, P MENZIONE, A MEYER, T MIKAMO, S MILLER, M MIMASHI, T MISCETTI, S MISHINA, M MIYASHITA, S MORITA, Y MOULDING, S MUELLER, J MUKHERJEE, A NAKAE, LF NAKANO, I NELSON, C NEWMANHOLMES, C NG, JST NINOMIYA, M NODULMAN, L OGAWA, S PAOLETTI, R PARA, A PARE, E PATRICK, J PHILLIPS, TJ PLUNKETT, R PONDROM, L PROUDFOOT, J PUNZI, G QUARRIE, D RAGAN, K REDLINGER, G RHOADES, J ROACH, M RIMONDI, F RISTORI, L ROHALY, T ROODMAN, A SAKUMOTO, WK SANSONI, A SARD, RD SAVOYNAVARRO, A SCARPINE, V SCHLABACH, P SCHMIDT, EE SCHUB, MH SCHWITTERS, R SCRIBANO, A SEGLER, S SEIYA, Y SEKIGUCHI, M SHAPIRO, M SHAW, NM SHEAFF, M SHOCHET, M SIEGRIST, J SINERVO, P SKARHA, J SLIWA, K SMITH, DA SNIDER, FD SONG, L STDENIS, R STEFANINI, A SULLIVAN, G SWARTZ, RL TAKANO, M TARTARELLI, F TAKIKAWA, K TAREM, S THERIOT, D TIMKO, M TIPTON, P TKACZYK, S TOLLESTRUP, A TONNISON, J TRISCHUK, W TURINI, N TSAY, Y UKEGAWA, F UNDERWOOD, D VEJCIK, S VIDAL, R WAGNER, RG WAGNER, RL WAINER, N WALSH, J WATTS, T WEBB, R WENDT, C WENZEL, H WESTER, WC WESTHUSING, T WHITE, SN WICKLUND, AB WILLIAMS, HH WINER, BL WYSS, J YAGIL, A YAMASHITA, A YASUOKA, K YEH, GP YOH, J YOKOYAMA, M YUN, JC ZANETTI, A ZETTI, F ZUCCHELLI, S TI SEARCH FOR W' -] EV AND W' -] MU-V IN PBARP COLLISIONS AT SQUARE-ROOT-S = 1.8 TEV SO PHYSICAL REVIEW LETTERS LA English DT Article ID RIGHT-HANDED CURRENTS; DECAY; SCATTERING; COLLIDER AB The W' is a charged, heavy, vector boson predicted to exist by some extensions of the standard model. We have searched for the processes W' --> ev and W'--> mu-v for M(W') > 100 GeV/c2, in ppBAR collisions at square-root s = 1.8 TeV, using data taken with the Collider Detector at Fermilab. The nonobservation of these processes leads to a lower limit of 520 GeV/c2 (95% confidence level) on the mass of the W', assuming standard-strength couplings to three fermion generations. C1 BRANDEIS UNIV, WALTHAM, MA 02254 USA. UNIV CHICAGO, CHICAGO, IL 60637 USA. FERMI NATL ACCELERATOR LAB, BATAVIA, IL 60510 USA. IST NAZL FIS NUCL, LAB NAZL FRASCATI, FRASCATI, ITALY. HARVARD UNIV, CAMBRIDGE, MA 02138 USA. UNIV ILLINOIS, URBANA, IL 61801 USA. JOHNS HOPKINS UNIV, BALTIMORE, MD 21218 USA. KEK NAT LAB HIGH ENERGY PHYS, NATL LAB HIGH ENERGY PHYS, TSUKUBA, IBARAKI 305, JAPAN. UNIV CALIF BERKELEY, LAWRENCE BERKELEY LAB, BERKELEY, CA 94720 USA. IST NAZL FIS NUCL, I-35131 PADUA, ITALY. UNIV PENN, PHILADELPHIA, PA 19104 USA. UNIV PISA, IST NAZL FIS NUCL, I-56100 PISA, ITALY. SCUOLA NORMALE SUPER PISA, I-56100 PISA, ITALY. PURDUE UNIV, W LAFAYETTE, IN 47907 USA. UNIV ROCHESTER, ROCHESTER, NY 14627 USA. ROCKEFELLER UNIV, NEW YORK, NY 10021 USA. RUTGERS STATE UNIV, PISCATAWAY, NJ 08854 USA. TEXAS A&M UNIV SYST, COLLEGE STN, TX 77843 USA. UNIV TSUKUBA, TSUKUBA, IBARAKI 305, JAPAN. TUFTS UNIV, MEDFORD, MA 02155 USA. UNIV WISCONSIN, MADISON, WI 53706 USA. RP ABE, F (reprint author), ARGONNE NATL LAB, ARGONNE, IL 60439 USA. RI St.Denis, Richard/C-8997-2012; Chiarelli, Giorgio/E-8953-2012; Punzi, Giovanni/J-4947-2012 OI Chiarelli, Giorgio/0000-0001-9851-4816; Punzi, Giovanni/0000-0002-8346-9052 NR 18 TC 34 Z9 34 U1 0 U2 0 PU AMER PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 0031-9007 EI 1079-7114 J9 PHYS REV LETT JI Phys. Rev. Lett. PD NOV 4 PY 1991 VL 67 IS 19 BP 2609 EP 2613 DI 10.1103/PhysRevLett.67.2609 PG 5 WC Physics, Multidisciplinary SC Physics GA GM792 UT WOS:A1991GM79200005 ER PT J AU TESANOVIC, Z LEI, X AF TESANOVIC, Z LEI, X TI CRITICAL FLUCTUATIONS IN STRONGLY TYPE-II QUASI-2-DIMENSIONAL SUPERCONDUCTORS SO PHYSICAL REVIEW LETTERS LA English DT Article ID HIGH-TC SUPERCONDUCTORS; PERTURBATION-SERIES; MAGNETIC-FIELD; FLUX LIQUIDS; TRANSITION; BEHAVIOR; HC2 AB The critical fluctuations near H(c2)(T) in the mixed phase of layered type-II superconductors are related to an equivalent system of classical particles with many-body "gauge" interactions. The scale invariance of this dense vortex plasma leads to a universal character of the vortex solid-liquid melting line where the transition to the superconducting state occurs. The relation to experimental situation in high-T(c) and other layered superconductors and superconducting thin films is discussed. C1 UNIV CALIF LOS ALAMOS SCI LAB,DIV THEORET,LOS ALAMOS,NM 87545. MAX PLANCK INST FESTKORPERFORSCH,HIGH FIELD MAGNETLABOR,F-38042 GRENOBLE,FRANCE. RP TESANOVIC, Z (reprint author), JOHNS HOPKINS UNIV,DEPT PHYS & ASTRON,BALTIMORE,MD 21218, USA. NR 26 TC 99 Z9 99 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 NOV 4 PY 1991 VL 67 IS 19 BP 2729 EP 2732 DI 10.1103/PhysRevLett.67.2729 PG 4 WC Physics, Multidisciplinary SC Physics GA GM792 UT WOS:A1991GM79200035 ER PT J AU ROTTER, LD SCHLESINGER, Z COLLINS, RT HOLTZBERG, F FIELD, C WELP, UW CRABTREE, GW LIU, JZ FANG, Y VANDERVOORT, KG FLESHLER, S AF ROTTER, LD SCHLESINGER, Z COLLINS, RT HOLTZBERG, F FIELD, C WELP, UW CRABTREE, GW LIU, JZ FANG, Y VANDERVOORT, KG FLESHLER, S TI DEPENDENCE OF THE INFRARED PROPERTIES OF SINGLE-DOMAIN YBA2CU3O7-Y ON OXYGEN-CONTENT SO PHYSICAL REVIEW LETTERS LA English DT Article ID SUPERCONDUCTING ENERGY-GAP; HIGH-TC SUPERCONDUCTOR; CONDUCTIVITY; REFLECTIVITY; CRYSTALS; ANISOTROPY; DYNAMICS AB The first polarized infrared-reflectivity measurements of untwinned crystals of YBa2Cu3O7-y as a function of y are reported. We separate the chain and plane contributions to the infrared conductivity, and find that for crystals with T(c) greater-than-or-similar-to 50 K the prominent normal-state midinfrared feature is associated with the chains. A threshold in the plane conductivity at approximately 500 cm-1 has a strong temperature dependence just below T(c) suggesting an association with the superconducting gap. Its temperature dependence above and below T(c) is quite similar to that of relevant NMR data, and is suggestive of gap development in the normal state. C1 ARGONNE NATL LAB, SCI & TECHNOL CTR SUPERCOND, ARGONNE, IL 60439 USA. ARGONNE NATL LAB, DIV MAT SCI, ARGONNE, IL 60439 USA. UNIV CALIF DAVIS, DEPT PHYS, DAVIS, CA 95616 USA. RP ROTTER, LD (reprint author), IBM CORP, THOMAS J WATSON RES CTR, YORKTOWN HTS, NY 10598 USA. RI Collins, Reuben/O-2545-2014 OI Collins, Reuben/0000-0001-7910-3819 NR 24 TC 194 Z9 194 U1 0 U2 3 PU AMER PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 0031-9007 J9 PHYS REV LETT JI Phys. Rev. Lett. PD NOV 4 PY 1991 VL 67 IS 19 BP 2741 EP 2744 DI 10.1103/PhysRevLett.67.2741 PG 4 WC Physics, Multidisciplinary SC Physics GA GM792 UT WOS:A1991GM79200038 ER PT J AU LORENZ, JC TEUFEL, LW WARPINSKI, NR AF LORENZ, JC TEUFEL, LW WARPINSKI, NR TI REGIONAL FRACTURES .1. A MECHANISM FOR THE FORMATION OF REGIONAL FRACTURES AT DEPTH IN FLAT-LYING RESERVOIRS SO AAPG BULLETIN-AMERICAN ASSOCIATION OF PETROLEUM GEOLOGISTS LA English DT Article ID EAST TEXAS BASIN; APPALACHIAN PLATEAU; JOINT SETS; STRESS-FIELD; COMPRESSION; PATTERNS; EXAMPLE; ROCKS; DIRECTIONS; SANDSTONE AB "Regional" fractures may form slowly, at depth, in extension, and parallel to regional horizontal tectonic compression. Such fracture sets can be common in reservoirs despite the absence of flexure of the strata, and are commonly important contributors to reservoir permeability. Such fractures make good targets for deviated wells. High formation pore pressure is crucial to creating low effective confining stresses and brittle rock properties in the reservoirs (conditions conducive to fracturing) despite deep burial, but pore pressure does not exceed the least principal stress and does not cause tensile fracturing: the mechanism of natural hydraulic fracturing is incompatible with the characteristics of most regional fracture sets. Rather, many regional fractures form during far-field compression, initiate at locally induced tensile stresses caused by flaws in the rock, and propagate in the plane of the maximum and intermediate compressive stresses. The differential stress required for initiation and propagation of regional fractures is well below that necessary for shear failure. In the presence of high pore pressure, fractures can be held open at depth by a tectonic, basinwide dilatancy of the strata, and the open void space commonly becomes mineralized. C1 SANDIA NATL LABS,DIV 6232,ALBUQUERQUE,NM 87185. RP LORENZ, JC (reprint author), SANDIA NATL LABS,DIV 6253,ALBUQUERQUE,NM 87185, USA. NR 144 TC 98 Z9 112 U1 1 U2 6 PU AMER ASSN PETROL GEOLOGISTS PI TULSA PA 1444 S BOULDER AVE PO BOX 979, TULSA, OK 74101 SN 0149-1423 J9 AAPG BULL JI AAPG Bull.-Am. Assoc. Petr. Geol. PD NOV PY 1991 VL 75 IS 11 BP 1714 EP 1737 PG 24 WC Geosciences, Multidisciplinary SC Geology GA GN269 UT WOS:A1991GN26900003 ER PT J AU LORENZ, JC FINLEY, SJ AF LORENZ, JC FINLEY, SJ TI REGIONAL FRACTURES .2. FRACTURING OF MESAVERDE RESERVOIRS IN THE PICEANCE BASIN, COLORADO SO AAPG BULLETIN-AMERICAN ASSOCIATION OF PETROLEUM GEOLOGISTS LA English DT Article ID ROCKY-MOUNTAIN FORELAND; WESTERN UNITED-STATES; FLUID INCLUSIONS; LOW-PERMEABILITY; INSITU STRESS; NEW-YORK; FIELD; SANDSTONE; BEARING; STRAIN AB Cretaceous strata in the east-central Piceance basin of northwestern Colorado were subjected to several phases of stress due to horizontal tectonic compression, burial, and uplift. These rocks contain a regional set of west-northwest extension fractures, observed in abundant vertical and deviated core from the U.S. Department of Energy's Multiwell Experiment and Slant Hole Completion Test wells. Time-depth relationships, fracture orientation, and fluid inclusion analyses indicate that the fractures formed at about 36-40 Ma, during a phase of increased Laramide west-northwest compression, and in a pressure-temperature regime compatible with the geologically reconstructed maximum burial depths. This regional fracturing is an example of load-parallel extension fracturing and basinwide dilatancy at depth, under conditions of high pore pressure and anisotropic, tectonically created, horizontal stress. RP LORENZ, JC (reprint author), SANDIA NATL LABS,DIV GEOTECHNOL 6253,ALBUQUERQUE,NM 87185, USA. NR 100 TC 42 Z9 48 U1 0 U2 1 PU AMER ASSN PETROL GEOLOGISTS PI TULSA PA 1444 S BOULDER AVE PO BOX 979, TULSA, OK 74101 SN 0149-1423 J9 AAPG BULL JI AAPG Bull.-Am. Assoc. Petr. Geol. PD NOV PY 1991 VL 75 IS 11 BP 1738 EP 1757 PG 20 WC Geosciences, Multidisciplinary SC Geology GA GN269 UT WOS:A1991GN26900004 ER PT J AU WANG, ZL AF WANG, ZL TI MULTIPLE INELASTIC-SCATTERING IN HIGH-ENERGY ELECTRON-DIFFRACTION AND IMAGING SO ACTA CRYSTALLOGRAPHICA SECTION A LA English DT Article ID KIKUCHI PATTERNS; CRYSTALS; STEM AB A dynamical multiple elastic and inelastic electron scattering theory is proposed and is applied to the plural scattering cases of phonon, single-electron and valence (or plasmon) excitations. The incoherence of all the possible inelastic scattering processes of different energies and momenta is evaluated analytically before any numerical calculations. The effects of multiple scattering are equivalent partially to the broadening of the scattering function of a single inelastic process by those of others and partially to the re-scattering of the Kikuchi pattern produced in one inelastic process by others. The final diffraction pattern is a convoluted result of those Kikuchi patterns produced by different inelastic scattering processes. All these characteristics can be considered in just one single formula. The theory of multiple-phonon excitations in simulating high-angle annular-dark-field (ADF) scanning transmission electron-microscopy (STEM) images is proposed. It is shown that the single-phonon scattering model is a good approximation except at the points close to atomic nuclei if the electron probe is comparable in size to that of an atom. The higher-order phonon scattering may improve the resolution of the ADF STEM images of thin crystals. C1 UNIV TENNESSEE,DEPT MAT SCI & ENGN,KNOXVILLE,TN 37996. RP WANG, ZL (reprint author), OAK RIDGE NATL LAB,DIV MET & CERAM,POB 2008,BLDG 5500,MS 6376,OAK RIDGE,TN 37831, USA. RI Wang, Zhong Lin/E-2176-2011 OI Wang, Zhong Lin/0000-0002-5530-0380 NR 43 TC 4 Z9 4 U1 0 U2 3 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 NOV 1 PY 1991 VL 47 BP 686 EP 698 DI 10.1107/S0108767391005524 PN 6 PG 13 WC Chemistry, Multidisciplinary; Crystallography SC Chemistry; Crystallography GA GR135 UT WOS:A1991GR13500005 ER PT J AU TOME, CN LEBENSOHN, RA KOCKS, UF AF TOME, CN LEBENSOHN, RA KOCKS, UF TI A MODEL FOR TEXTURE DEVELOPMENT DOMINATED BY DEFORMATION TWINNING - APPLICATION TO ZIRCONIUM ALLOYS SO ACTA METALLURGICA ET MATERIALIA LA English DT Article ID YIELD SURFACE; POLYCRYSTALS AB In many polycrystals of less than cubic crystal symmetry, plastic deformation is dominated by twinning. In particular, we will treat the case of Zr and Zr alloys in detail. We propose a new method for modelling grain reorientation due to twinning, which is based on a Volume Fraction Transfer (VFT) scheme; the scheme is also applied to the slip modes. We find that this method predicts textures that are, when twinning is the dominant mode, considerably different from, and in better agreement with experiment than the conventional schemes which reorient an entire grain when some criterion has been met. Various combinations of slip and twinning modes and of the associated critical stresses are systematically investigated for the case of rolling, tension and compression of Zr alloys. A comparison of various predicted and experimental textures leads to the conclusion that twinning must, indeed, be controlling texture development. C1 UNIV CALIF LOS ALAMOS SCI LAB, CTR MAT SCI, MS K765, LOS ALAMOS, NM 87545 USA. RP TOME, CN (reprint author), CONSEJO NACL INVEST CIENT & TECN, UNR, INST FIS ROSARIO, 27 FEBRERO 210 BIS, RA-2000 ROSARIO, ARGENTINA. RI Lebensohn, Ricardo/A-2494-2008; Kocks, Fred/E-1159-2011; Tome, Carlos/D-5058-2013 OI Lebensohn, Ricardo/0000-0002-3152-9105; NR 27 TC 306 Z9 313 U1 6 U2 47 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 NOV PY 1991 VL 39 IS 11 BP 2667 EP 2680 DI 10.1016/0956-7151(91)90083-D PG 14 WC Materials Science, Multidisciplinary; Metallurgy & Metallurgical Engineering SC Materials Science; Metallurgy & Metallurgical Engineering GA GN537 UT WOS:A1991GN53700022 ER PT J AU BACHER, P WYNBLATT, P FOILES, SM AF BACHER, P WYNBLATT, P FOILES, SM TI A MONTE-CARLO STUDY OF THE STRUCTURE AND COMPOSITION OF (001) SEMICOHERENT INTERPHASE BOUNDARIES IN CU-AG-AU ALLOYS SO ACTA METALLURGICA ET MATERIALIA LA English DT Article ID EMBEDDED-ATOM METHOD; METALS AB Monte Carlo simulation, in conjunction with embedded atom method, has been used to model the composition and structure of semicoherent (001) interphase boundaries separating coexisting Cu-rich and Ag-rich phases in a ternary Cu-Ag-Au alloy. This approach has also been used to re-examine previous results obtained on two-phase binary Cu-Ag alloys. Results of computations performed at 600 and 900 K on both binary and ternary alloys show good agreement between predicted bulk phase composition and the experimental phase diagrams. A statistical structural and compositional analysis of the atomic configurations at interfaces has shown that the (001) interface is unstable and tends to break down into {111} facets. This faceting manifests itself as the formation of silver-rich pyramids which penetrate deeply into the copper-rich phase. Possible sources for the instability of the (001) interface are discussed. It is also found that while this faceting is well defined at 600 K, it is substantially smeared out at 900 K. Segregation of gold occurs along the facet surfaces, and as a result appears to be weak in composition profiles calculated along the [001] direction. This conclusion about the nature of the composition profiles in confirmed by comparisons between the results obtained in the early stages of the simulation, when the (001) interface is metastable, and from a regular solution model of the composition profile across a coherent (001) interface. C1 SANDIA NATL LABS, LIVERMORE, CA 94550 USA. RP BACHER, P (reprint author), CARNEGIE MELLON UNIV, DEPT MET ENGN & MAT SCI, PITTSBURGH, PA 15213 USA. NR 17 TC 28 Z9 28 U1 0 U2 3 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 NOV PY 1991 VL 39 IS 11 BP 2681 EP 2691 DI 10.1016/0956-7151(91)90084-E PG 11 WC Materials Science, Multidisciplinary; Metallurgy & Metallurgical Engineering SC Materials Science; Metallurgy & Metallurgical Engineering GA GN537 UT WOS:A1991GN53700023 ER PT J AU HEUSER, BJ KING, JS SUMMERFIELD, GC BOUE, F EPPERSON, JE AF HEUSER, BJ KING, JS SUMMERFIELD, GC BOUE, F EPPERSON, JE TI SANS MEASUREMENT OF DEUTERIUM TRAPPING AT DISLOCATIONS AND GRAIN-BOUNDARIES IN PALLADIUM SO ACTA METALLURGICA ET MATERIALIA LA English DT Article ID HYDROGEN AB Small angle neutron scattering (SANS) measurements have been made on deformed single crystal and polycrystalline palladium with and without deuterium dissolved in the solution phase at room temperature. The net scattering cross section for the same sample-with and without deuterium loading shows a behavior expected from deuterium correlation with dislocations forming rod-like scattering structures. We conclude from these scattering measurements that the trapped deuterium is within 2-3 Burgers vectors of the dislocation core. On average 1-3 deuterons per angstrom are trapped at dislocations in the deformed samples. The measurements indicate the straight, rod-like correlation geometry extends on average 50-100 angstrom along the dislocations. Net scattering from a well annealed polycrystalline palladium sample exhibiting a behavior expected from surfaces has been observed. This net scattering is attributed to deuterium trapped at grain boundaries in the polycrystalline sample. A value of 0.4 +/- 0.2 trapped deuterons per angstrom 2 of grain boundary area is calculated from the well annealed polycrystalline scattering measurement. C1 CENS, LEON BRILLOUIN LAB, F-91190 GIF SUR YVETTE, FRANCE. UNIV MICHIGAN, DEPT NUCL ENGN, ANN ARBOR, MI 48109 USA. ARGONNE NATL LAB, DIV MAT SCI, ARGONNE, IL 60439 USA. RI boue, francois/C-6062-2008 OI boue, francois/0000-0002-6799-3292 NR 10 TC 21 Z9 21 U1 0 U2 4 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 NOV PY 1991 VL 39 IS 11 BP 2815 EP 2824 DI 10.1016/0956-7151(91)90099-M PG 10 WC Materials Science, Multidisciplinary; Metallurgy & Metallurgical Engineering SC Materials Science; Metallurgy & Metallurgical Engineering GA GN537 UT WOS:A1991GN53700038 ER PT J AU VERHOEVEN, JD CHUMBLEY, LS LAABS, FC SPITZIG, WA AF VERHOEVEN, JD CHUMBLEY, LS LAABS, FC SPITZIG, WA TI MEASUREMENT OF FILAMENT SPACING IN DEFORMATION PROCESSED CU-NB ALLOYS SO ACTA METALLURGICA ET MATERIALIA LA English DT Article ID MICROSTRUCTURAL EVOLUTION; COMPOSITE WIRES; STRENGTH; RESISTIVITY AB Previous studies of Cu-20 vol .% Nb alloys used optical and SEM techniques to evaluate the thickness and spacing of the Nb filaments. It had been known that the filament sizes were smaller than the resolution limit of the SEM at high deformation strain but it was assumed that this problem would not significantly change the observed trends. Results of this TEM study using dark-field techniques on the same materials show that the previous SEM measurements significantly overestimated the spacing at the higher deformations. Analysis of resistivity data on the samples also confirms this result. The strength dependence on Cu channel spacing, t(cu), was found to display a large transition region, with the dependence changing from a t(cu)-0.5 at low strains to a t(cu)-0.38 at high strains. The significance of these results is discussed. It is also pointed out that the filament sizes observed at high strains in these materials range to below 20 nm and they exhibit strength/filament size characteristics similar to vapor deposited nanocrystalline materials. C1 IOWA STATE UNIV SCI & TECHNOL, AMES LAB, AMES, IA 50011 USA. RP VERHOEVEN, JD (reprint author), IOWA STATE UNIV SCI & TECHNOL, DEPT MAT SCI ENGN, AMES, IA 50011 USA. NR 27 TC 90 Z9 98 U1 0 U2 2 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 NOV PY 1991 VL 39 IS 11 BP 2825 EP 2834 DI 10.1016/0956-7151(91)90100-F PG 10 WC Materials Science, Multidisciplinary; Metallurgy & Metallurgical Engineering SC Materials Science; Metallurgy & Metallurgical Engineering GA GN537 UT WOS:A1991GN53700039 ER PT J AU MINNICK, MF SMALL, CL FRAZIER, ME MALLAVIA, LP AF MINNICK, MF SMALL, CL FRAZIER, ME MALLAVIA, LP TI ANALYSIS OF STRAIN-SPECIFIC PLASMID SEQUENCES FROM COXIELLA-BURNETII SO ACTA VIROLOGICA LA English DT Article DE Q-FEVER; PLASMIDS; GENE EXPRESSION; RICKETTSIA AB Acute isolates of Coxiella burnetii possess a 36-kbp plasmid termed QpH1. DNA hybridizations show that QpH1 contains a approximately 6-kbp region of DNA which is not present in the QpRS plasmid from chronic isolates. This QpH1-specific region of DNA contains the contiguous EcoRI fragments G, E, and D. The GED region was found to possess seven open reading frames (ORF's) coding for proteins ranging from 5.5 to 42.3 kDa in molecular mass when subcloned and expressed in vitro. Summing the predicted ORF's accounts for 95 % of the GED coding potential. E. coli expression produced a stable 42.3-kDa protein from the pHIN19 subclone of GED. The ORF of the 42.3-kDa protein, termed cbhE', has been localized on GED by both in vitro transcription/translation and DNA sequencing. The cbhE' gene is estimated as 1142 bp in length with a putative promoter region of TCAACT (-35)-N-16-TAAAAT (-10)-N-14-AGAAGGA (Shine-Dalgarno)--N-10-ATG. C1 WASHINGTON STATE UNIV, DEPT MICROBIOL, PULLMAN, WA 99164 USA. PACIFIC NW LAB, DEPT BIOL, RICHLAND, WA 99352 USA. NR 16 TC 3 Z9 3 U1 1 U2 2 PU SLOVAK ACADEMIC PRESS LTD PI BRATISLAVA PA PO BOX 57, NAM SLOBODY 6, 810 05 BRATISLAVA, SLOVAKIA SN 0001-723X J9 ACTA VIROL JI Acta Virol. PD NOV PY 1991 VL 35 IS 6 BP 497 EP 502 PG 6 WC Virology SC Virology GA HB173 UT WOS:A1991HB17300001 PM 1687630 ER PT J AU ROMAN, MJ CRISSMAN, HA SAMSONOFF, WA HECHEMY, KE BACA, OG AF ROMAN, MJ CRISSMAN, HA SAMSONOFF, WA HECHEMY, KE BACA, OG TI ANALYSIS OF COXIELLA-BURNETII ISOLATES IN CELL-CULTURE AND THE EXPRESSION OF PARASITE-SPECIFIC ANTIGENS ON THE HOST MEMBRANE-SURFACE SO ACTA VIROLOGICA LA English DT Article DE COXIELLA-BURNETII ISOLATES; CLASSIFICATION; PLASMIDS; SURFACE ANTIGENS; FLOW CYTOMETRY ID LYSOSOMAL RESPONSE; MODEL; INFECTION; FATE AB Coxiella burnetii isolates may be classified into several groups based on plasmid character. These groups may also be correlated with disease syndrome - chronic or short-term acute. L929 mouse fibroblast cells were exposed, independently, to two members of the three major C. burnetii groups, and their growth /morphological characteristics analysed by light and electron microscopy, including High Voltage Electron Microscopy. The fates of the isolates were followed. Two acute isolates [Nine Mile (RSA 493) and Henzerling (RSA 331), QpH1-type plasmids] and two chronic isolates (S Q217 and L Q216, plasmidless) readily infected L929 cells in static culture. Priscilla (Q177) and F (Q228) isolates (QpRS-type plasmid, and implicated in causing chronic Q fever) took longer to infect cells, and, unlike the members of the other two groups, gradually disappeared when shifted to suspension culture. Cells infected with Q177 and Q228 exhibited a higher degree of vacuolation than cells infected with the other isolates. Parasite-specific antigens on the surfaces of the host cells were analysed by immunofluorescence/flow cytometry. The acute and plasmidless isolates caused the display of significantly more C. burnetii-specific antigen on the host cell membrane than the two QpRS plasmid-containing isolates. This host cell model system clearly reveals biological differences among the C. burnetii groups. C1 NEW YORK STATE DEPT HLTH,WADSWORTH CTR LABS & RES,ALBANY,NY 12201. UNIV CALIF LOS ALAMOS SCI LAB,LOS ALAMOS,NM 87544. RP ROMAN, MJ (reprint author), UNIV NEW MEXICO,ALBUQUERQUE,NM 87131, USA. NR 11 TC 15 Z9 15 U1 0 U2 1 PU SLOVAK ACADEMIC PRESS LTD PI BRATISLAVA PA PO BOX 57, NAM SLOBODY 6, 810 05 BRATISLAVA, SLOVAKIA SN 0001-723X J9 ACTA VIROL JI Acta Virol. PD NOV PY 1991 VL 35 IS 6 BP 503 EP 510 PG 8 WC Virology SC Virology GA HB173 UT WOS:A1991HB17300002 PM 1687632 ER PT J AU FRAZIER, ME HEINZEN, RA STIEGLER, GL MALLAVIA, LP AF FRAZIER, ME HEINZEN, RA STIEGLER, GL MALLAVIA, LP TI PHYSICAL MAPPING OF THE COXIELLA-BURNETII GENOME SO ACTA VIROLOGICA LA English DT Article DE COXIELLA-BURNETII; RICKETTSIAE; PULSED FIELD GRADIENT ELECTROPHORESIS; RESTRICTION MAPPING ID GEL-ELECTROPHORESIS; PLASMID; LIPOPOLYSACCHARIDE; SEPARATION; SEQUENCES AB Coxiella burnetii isolates from different genomic groups contain restriction fragment polymorphisms that were easily distinguishable using pulsed field gradient electrophoresis (PFGE). Conversely, isolates that belong to the same genomic group yield identical patterns indicating that PFGE can be used to identify the genomic grouping of new C. burnetii isolates. Intact C. burnetii cells were embedded in agarose and lysed in situ. The genomic DNA was digested with low-frequency cutting restriction endonucleases, and subjected to PFGE analysis. NotI and SfiI cut C. burnetii DNA least often and produced the largest fragments. ApaI, MluI, SalI, XbaI or XhoI produced only small DNA fragments (+/- 50 kbp). When PFGE was used to analyse C. burnetii genomes for the presence of plasmid-related sequences, all the plasmid sequences in Nine Mile and Priscilla were associated with their 36 kbp or 39 kbp plasmid bands, respectively. If these isolates contained plasmid sequences which had integrated into their chromosomes those sequences would have been visible as additional bands. These same studies also showed that plasmid sequences in the plasmidless-Ko isolate were completely contained within two NotI fragments, indicating that the integrated plasmid is localized to a concise region of the C. burnetii genome. Since it is difficult to conduct genetic analyses of obligate intracellular parasites using standard techniques, a physical map is being developed using PFGE. In addition to providing a means for determining gene loci, the physical maps provide a means for comparing genetic organization among the different strains of C. burnetii. C1 WASHINGTON STATE UNIV, DEPT MICROBIOL, PULLMAN, WA 99164 USA. RP FRAZIER, ME (reprint author), PACIFIC NW LAB, RICHLAND, WA 99352 USA. FU NIAID NIH HHS [AI20190] NR 14 TC 3 Z9 3 U1 1 U2 2 PU SLOVAK ACADEMIC PRESS LTD PI BRATISLAVA PA PO BOX 57, NAM SLOBODY 6, 810 05 BRATISLAVA, SLOVAKIA SN 0001-723X J9 ACTA VIROL JI Acta Virol. PD NOV PY 1991 VL 35 IS 6 BP 511 EP 518 PG 8 WC Virology SC Virology GA HB173 UT WOS:A1991HB17300003 PM 1687633 ER PT J AU RESCHKE, DK FRAZIER, ME MALLAVIA, LP AF RESCHKE, DK FRAZIER, ME MALLAVIA, LP TI TRANSFORMATION AND GENOMIC RESTRICTION MAPPING OF ROCHALIMAEA SPP SO ACTA VIROLOGICA LA English DT Article DE ROCHALIMAEA; TRENCH FEVER; TRANSFORMATION; ELECTROPORATION; RICKETTSIA; PLASMIDS; PULSED FIELD GRADIENT ELECTROPHORESIS; RESTRICTION; GENOMIC MAPPING ID HIGH-EFFICIENCY TRANSFORMATION; HIGH-VOLTAGE ELECTROPORATION; ESCHERICHIA-COLI; PLASMID DNA; RICKETTSIAE AB Transformation procedures using electroporation were established for Rochalimae quintana. Several cosmid/plasmids possessing the RK2 or RSF1010 origin of replication were successfully inserted. Plasmid retention and replication were verified by antibiotic resistance and Southern blot analysis. The highest level of transformation was obtained at a voltage field strength of 12.5 kV/cm with a pulse time of 10 miliseconds. Transformation efficiency was low (0.3 %) with approximately 10(5) transformants/microgram of DNA. One construct, designated pAG10, reached sufficient levels in R. quintana to be isolated by density gradient centrifugation. Analysis of this plasmid after several cycles of growth in R. quintana revealed no obvious modifications. Physical maps of Rochalimaea spp. chromosomal DNA using pulse-field electrophoresis are being developed. Digestion of R. vinsonii chromosomal DNA with NotI or SfiI resulted in three and one fragments, respectively. When R. quintana was digested in a similar manner, both NotI and SfiI produced four fragments. Double digestion of R. quintana DNA with NotI and SfiI yield seven fragments ranging in size from 11 to 925 kb. Summing the fragments indicate an approximate genome size of 2.1 x 10(6) bp for R. vinsonii and 1.7 x 10(6) bp for R. quintana chromosomal DNA. C1 WASHINGTON STATE UNIV, DEPT MICROBIOL, PULLMAN, WA 99164 USA. PACIFIC NW LAB, DEPT BIOL, RICHLAND, WA 99352 USA. FU NIAID NIH HHS [AI 20190] NR 17 TC 7 Z9 7 U1 0 U2 0 PU SLOVAK ACADEMIC PRESS LTD PI BRATISLAVA PA PO BOX 57, NAM SLOBODY 6, 810 05 BRATISLAVA, SLOVAKIA SN 0001-723X J9 ACTA VIROL JI Acta Virol. PD NOV PY 1991 VL 35 IS 6 BP 519 EP 525 PG 7 WC Virology SC Virology GA HB173 UT WOS:A1991HB17300004 PM 1687634 ER PT J AU FRYE, G AF FRYE, G TI MASS-SPECTROMETER ON A CHIP SO ADVANCED MATERIALS & PROCESSES LA English DT Note RP FRYE, G (reprint author), SANDIA NATL LABS,POB 5800,DIV 1846,ALBUQUERQUE,NM 87185, USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU ASM INTERNATIONAL PI MATERIALS PARK PA SUBSCRIPTIONS SPECIALIST CUSTOMER SERVICE, MATERIALS PARK, OH 44073-0002 SN 0026-0665 J9 ADV MATER PROCESS JI Adv. Mater. Process. PD NOV PY 1991 VL 140 IS 5 BP 6 EP 6 PG 1 WC Materials Science, Multidisciplinary SC Materials Science GA GP091 UT WOS:A1991GP09100002 ER PT J AU ALLEN, JJ MARTINEZ, DR AF ALLEN, JJ MARTINEZ, DR TI TECHNIQUES FOR IMPLEMENTING STRUCTURAL MODEL IDENTIFICATION USING TEST DATA SO AIAA JOURNAL LA English DT Article AB Structural system identification methods are analytical techniques for reconciling test data with analytical models. For system identification to become a practical tool for engineering analysis, the estimation techniques/codes must communicate with finite element software packages, without intensive analyst intervention and supervision. This paper presents a technique used to integrate commercial software packages for finite element modeling, mathematical programming techniques, and general linear system analysis. Two examples of application of this software using measured data are presented. The examples consist of a truss structure in which the model form is well defined, and an electronics package whose model form is ill defined since it is difficult to model such structures with finite elements. A comparison of the resulting updated models with the experimental data shows significant improvement. RP ALLEN, JJ (reprint author), SANDIA NATL LABS,DIV STRUCT DYNAM 1545,POB 5800,ALBUQUERQUE,NM 87185, USA. NR 23 TC 1 Z9 1 U1 0 U2 0 PU AMER INST AERONAUT ASTRONAUT PI RESTON PA 1801 ALEXANDER BELL DRIVE, STE 500, RESTON, VA 22091 SN 0001-1452 J9 AIAA J JI AIAA J. PD NOV PY 1991 VL 29 IS 11 BP 1937 EP 1944 DI 10.2514/3.10822 PG 8 WC Engineering, Aerospace SC Engineering GA GM809 UT WOS:A1991GM80900023 ER PT J AU NOVAK, CF LAKE, LW SCHECHTER, RS AF NOVAK, CF LAKE, LW SCHECHTER, RS TI GEOCHEMICAL MODELING OF 2-PHASE FLOW WITH INTERPHASE MASS-TRANSFER SO AICHE JOURNAL LA English DT Article ID PRECIPITATION DISSOLUTION WAVES; CHEMICAL-REACTIONS; MINERAL SEQUENCES; PERMEABLE MEDIA; POROUS-MEDIA; TRANSPORT AB Injecting an acidic aqueous solution into a carbonate-rich permeable medium can cause the formation of a mobile gas phase through mineral dissolution. The flowing gas can cause significant changes in mineral identities through interaction with the initially present mineral and aqueous species. We have developed a solution to such transport problems based on a finite difference implicit-pressure/explicit-saturation formulation for two-phase flow, using the local equilibrium assumption as calculated with the Villars-Cruise-Smith stoichiometric chemical equilibrium algorithm. We illustrate the changes that occur to a calcite/iron (II) hydroxide medium upon injection of hydrochloric acid and the stripping of hydrogen sulfide gas from carbon dioxide gas injected into a siderite-rich medium. The examples demonstrate that the formation and/or presence of a gas phase can alter resident minerals and that minerals can remove impurities from a gas phase. C1 UNIV TEXAS,DEPT PETR ENGN,AUSTIN,TX 78712. UNIV TEXAS,DEPT CHEM ENGN,AUSTIN,TX 78712. RP NOVAK, CF (reprint author), SANDIA NATL LABS,ALBUQUERQUE,NM 87185, USA. NR 25 TC 5 Z9 5 U1 1 U2 3 PU AMER INST CHEMICAL ENGINEERS PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 SN 0001-1541 J9 AICHE J JI AICHE J. PD NOV PY 1991 VL 37 IS 11 BP 1625 EP 1633 DI 10.1002/aic.690371105 PG 9 WC Engineering, Chemical SC Engineering GA GP763 UT WOS:A1991GP76300004 ER PT J AU THOMAS, TL KANG, HK DALAGER, NA AF THOMAS, TL KANG, HK DALAGER, NA TI MORTALITY AMONG WOMEN VIETNAM VETERANS, 1973-1987 SO AMERICAN JOURNAL OF EPIDEMIOLOGY LA English DT Article DE ACCIDENTS; MORTALITY; NEOPLASMS; SUICIDE; VETERANS; WOMEN ID REGISTERED NURSES; CANCER; DEATH AB A retrospective cohort mortality study was conducted to examine health effects of US military service in Vietnam on women veterans who served there between July 4, 1965 and March 28, 1973. About 4,600 women Vietnam veterans and 5,300 women veterans who had never served in Vietnam were identified from military records and followed for vital status on December 31, 1987. Mortality rates for all causes of death combined and for all cancers among Vietnam veterans were similar to those among non-Vietnam veterans (relative risk (RR) = 0.93). There was a slight excess of mortality from external causes among women Vietnam veterans compared with non-Vietnam veterans (RR = 1.33), primarily due to an excess of motor vehicle accidents (RR = 3.19). Suicide rates were nearly the same in both cohorts (RR = 0.96). Vietnam veterans had twofold increases in mortality from cancers of the pancreas and uterine corpus compared with non-Vietnam veterans. Women Vietnam veterans and non-Vietnam veterans had lower-than-expected mortality from all causes of death combined (standardized mortality ratio (SMR) = 0.82 and 0.88, respectively), based on rates for US women, due to significant deficits of deaths from circulatory disease. Compared with rates for US women, mortality from cancers of the pancreas (five deaths, SMR = 3.27) and uterine corpus (four deaths, SMR = 4.05) was significantly elevated among Vietnam veteran nurses. C1 DEPT VET AFFAIRS,ENVIRONM EPIDEMIOL SERV,1825 K ST NW,SUITE 322,WASHINGTON,DC 20005. US DOE,DIV HLTH COMMUNICAT & COORDINAT,OFF EPIDEMIOL & HLTH SURVEILLANCE,WASHINGTON,DC. NR 22 TC 45 Z9 45 U1 1 U2 1 PU AMER J EPIDEMIOLOGY PI BALTIMORE PA 624 N BROADWAY RM 225, BALTIMORE, MD 21205 SN 0002-9262 J9 AM J EPIDEMIOL JI Am. J. Epidemiol. PD NOV 1 PY 1991 VL 134 IS 9 BP 973 EP 980 PG 8 WC Public, Environmental & Occupational Health SC Public, Environmental & Occupational Health GA GQ914 UT WOS:A1991GQ91400007 PM 1951295 ER PT J AU ESKENAZI, B WYROBEK, AJ FENSTER, L KATZ, DF SADLER, M LEE, J HUDES, M REMPEL, DM AF ESKENAZI, B WYROBEK, AJ FENSTER, L KATZ, DF SADLER, M LEE, J HUDES, M REMPEL, DM TI A STUDY OF THE EFFECT OF PERCHLOROETHYLENE EXPOSURE ON SEMEN QUALITY IN DRY CLEANING WORKERS SO AMERICAN JOURNAL OF INDUSTRIAL MEDICINE LA English DT Article DE TETRACHLOROETHYLENE; INFERTILITY; OCCUPATIONAL DISEASES; OLIGOSPERMIA; AZOOSPERMIA; SPERM COUNT; SPERM MOTION; SPERM MORPHOLOGY ID OCCUPATIONAL EXPOSURE; SPERM MORPHOLOGY; TETRACHLOROETHYLENE; SPERMATOZOA; INDUSTRY; RISK AB The purpose of this investigation was to determine the effects of perchloroethylene (PCE) exposure on human semen quality. We compared the semen quality of 34 dry cleaners with that of 48 laundry workers. We examined the relationships of 17 semen parameters to expired air levels of PCE and to an index of exposure based on job tasks in the last three months. The average sperm concentration was over 80 million for both dry cleaners and laundry workers, but approximately one-quarter of each group was oligospermic. The overall percentage of abnormal forms was similar for the two groups; however, sperm of dry cleaners were significantly more likely to be round (t = -3.29, p = 0.002) and less likely to be narrow (t = 2.35, p = 0.02) than the sperm of laundry workers. These effects were dose-related to expired air levels and to the exposure index after controlling for potential confounders (e.g., heat exposure). The average percent motile sperm for both groups was slightly over 60%; however, sperm of dry cleaners tended to swim with greater amplitude of lateral head displacement (ALH) than those of laundry workers (t = - 1.73, p = 0.09), and level of PCE in expired air was a significant predictor of ALH in the multiple regression model (t = 2.00, p = 0.05). In addition, exposure index was a significant negative predictor of the sperm linearity parameter (t = - 2.57, p = 0.01). These results suggest that occupational exposures to PCE can have subtle effects on sperm quality. Additional analyses are required to determine whether these effects are associated with changes in fertility. C1 CALIF DEPT HLTH SERV,CALIF OCCUPAT HLTH PROGRAM,BERKELEY,CA 94704. CALIF DEPT HLTH SERV,EPIDEMIOL STUDIES SECT,BERKELEY,CA 94704. UNIV CALIF LAWRENCE LIVERMORE NATL LAB,DIV BIOMED SCI,LIVERMORE,CA 94550. UNIV CALIF DAVIS,SCH MED,SCH MED,DEPT OBSTET & GYNECOL,DAVIS,CA 95616. UNIV CALIF BERKELEY,SCH PUBL HLTH,PROGRAM EPIDEMIOL,BERKELEY,CA 94720. UNIV CALIF BERKELEY,DEPT NUTR SCI,BERKELEY,CA 94720. UNIV CALIF BERKELEY,SCH PUBL HLTH,NO CALIF OCCUPAT HLTH CTR,BERKELEY,CA 94720. RP ESKENAZI, B (reprint author), UNIV CALIF BERKELEY,SCH PUBL HLTH,PROGRAM MATERNAL & CHILD HLTH,312 EARL WARREN HALL,BERKELEY,CA 94720, USA. RI Rempel, David/E-8424-2013 FU NIEHS NIH HHS [ES04699] NR 38 TC 52 Z9 55 U1 0 U2 3 PU WILEY-LISS PI NEW YORK PA DIV JOHN WILEY & SONS INC 605 THIRD AVE, NEW YORK, NY 10158-0012 SN 0271-3586 J9 AM J IND MED JI Am. J. Ind. Med. PD NOV PY 1991 VL 20 IS 5 BP 575 EP 591 DI 10.1002/ajim.4700200502 PG 17 WC Public, Environmental & Occupational Health SC Public, Environmental & Occupational Health GA GM896 UT WOS:A1991GM89600001 PM 1793101 ER PT J AU ESKENAZI, B FENSTER, L HUDES, M WYROBEK, AJ KATZ, DF GERSON, J REMPEL, DM AF ESKENAZI, B FENSTER, L HUDES, M WYROBEK, AJ KATZ, DF GERSON, J REMPEL, DM TI A STUDY OF THE EFFECT OF PERCHLOROETHYLENE EXPOSURE ON THE REPRODUCTIVE OUTCOMES OF WIVES OF DRY-CLEANING WORKERS SO AMERICAN JOURNAL OF INDUSTRIAL MEDICINE LA English DT Article DE TETRACHLOROETHYLENE; INFERTILITY; OCCUPATIONAL EXPOSURES; REPRODUCTIVE EFFECTS; PREGNANCY OUTCOMES ID SPONTANEOUS-ABORTIONS; DELAYED CONCEPTION; DIBROMOCHLOROPROPANE; INFERTILITY; WORKPLACE; FERTILITY; FINLAND AB The purpose of this investigation was to compare the reproductive outcomes of wives of men exposed to perchloroethylene in the dry-cleaning industry compared to those of wives of laundry workers. Seventeen female partners of dry cleaners and 32 partners of laundry workers were interviewed. The number of pregnancies and the standardized fertility ratios were similar between the two groups. Wives of dry cleaners did not have higher rates of spontaneous abortions. However, wives of dry cleaners were more than twice as likely to have a history of attempting to become pregnant for more than 12 months or to have sought care for an infertility problem. Cox proportional hazards models indicated that dry-cleaners' wives had half of the per-cycle pregnancy rate of wives of laundry workers, when controlling for other potential confounders (estimated rate ratio of 0.54, 95% C.I. = 0.23, 1.27). C1 UNIV CALIF DAVIS,SCH MED,SCH MED,DEPT OBSTET & GYNECOL,DAVIS,CA 95616. CALIF DEPT HLTH SERV,CALIF OCCUPAT HLTH PROGRAM,BERKELEY,CA 94704. CALIF DEPT HLTH SERV,EPIDEMIOL STUDIES SECT,BERKELEY,CA 94704. UNIV CALIF BERKELEY,DEPT NUTR SCI,BERKELEY,CA 94720. UNIV CALIF LAWRENCE LIVERMORE NATL LAB,DIV BIOMED SCI,LIVERMORE,CA 94550. UNIV CALIF BERKELEY,SCH PUBL HLTH,PROGRAM EPIDEMIOL,BERKELEY,CA 94720. UNIV CALIF BERKELEY,SCH PUBL HLTH,NO CALIF OCCUPAT HLTH CTR,BERKELEY,CA 94720. RP ESKENAZI, B (reprint author), UNIV CALIF BERKELEY,SCH PUBL HLTH,PROGRAM MATERNAL & CHILD HLTH,312 EARL WARREN HALL,BERKELEY,CA 94720, USA. RI Rempel, David/E-8424-2013 FU NIEHS NIH HHS [ES04699] NR 24 TC 30 Z9 31 U1 1 U2 2 PU WILEY-LISS PI NEW YORK PA DIV JOHN WILEY & SONS INC 605 THIRD AVE, NEW YORK, NY 10158-0012 SN 0271-3586 J9 AM J IND MED JI Am. J. Ind. Med. PD NOV PY 1991 VL 20 IS 5 BP 593 EP 600 DI 10.1002/ajim.4700200503 PG 8 WC Public, Environmental & Occupational Health SC Public, Environmental & Occupational Health GA GM896 UT WOS:A1991GM89600002 PM 1793102 ER PT J AU CRAWFORD, FS AF CRAWFORD, FS TI PULSE-COMPRESSION - DECHIRPING OF TIME-REVERSED SLINKY WHISTLERS SO AMERICAN JOURNAL OF PHYSICS LA English DT Note C1 UNIV CALIF BERKELEY LAWRENCE BERKELEY LAB,BERKELEY,CA 94720. RP CRAWFORD, FS (reprint author), UNIV CALIF BERKELEY,DEPT PHYS,BERKELEY,CA 94720, USA. NR 3 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 0002-9505 J9 AM J PHYS JI Am. J. Phys. PD NOV PY 1991 VL 59 IS 11 BP 1050 EP 1050 DI 10.1119/1.16649 PG 1 WC Education, Scientific Disciplines; Physics, Multidisciplinary SC Education & Educational Research; Physics GA GK753 UT WOS:A1991GK75300024 ER PT J AU NARAYANAN, VA BELLO, JM STOKES, DL VO-DINH, T AF NARAYANAN, VA BELLO, JM STOKES, DL VO-DINH, T TI DETERMINATION OF P-AMINOBENZOIC ACID IN PRESUN-15 LOTION USING SURFACE-ENHANCED RAMAN ANALYSIS SO ANALUSIS LA English DT Article DE RAMAN SPECTROMETRY; SURFACE-ENHANCED RAMAN; SUNSCREEN LOTION; PRESUN ANALYSIS; PARA-AMINOBENZOIC ACID ID SCATTERING ANALYSIS; SILVER ELECTRODE; SPECTROSCOPY; SPECTROMETRY; FILMS AB The p-aminobenzoic acid (PABA) content of Presun-15 lotion was analysed by the Surface-Enhanced Raman Scattering (SERS) technique using a silver-coated alumina substrate as the SERS-active medium. PABA standards and Presun-15 lotion were dissolved in ethanol and spotted on the substrate. The PABA signal at 1 132 cm-1 was used to estimate the PABA concentration with an accuracy of a few parts per million (ppm). The linear response was up to 16 ppm. C1 OAK RIDGE NATL LAB, DIV HLTH & SAFETY RES, ADV MONITORING DEV GRP, OAK RIDGE, TN 37831 USA. RP VO-DINH, T (reprint author), OAK RIDGE NATL LAB, DIV HLTH & SAFETY RES, ADV MONITORING DEV GRP, OAK RIDGE, TN 37831 USA. NR 18 TC 13 Z9 13 U1 0 U2 1 PU EDP SCIENCES S A PI LES ULIS CEDEX A PA 17, AVE DU HOGGAR, PA COURTABOEUF, BP 112, F-91944 LES ULIS CEDEX A, FRANCE SN 0365-4877 J9 ANALUSIS JI Analusis PD NOV PY 1991 VL 19 IS 9 BP 307 EP 310 PG 4 WC Chemistry, Analytical SC Chemistry GA GT716 UT WOS:A1991GT71600025 ER PT J AU PANG, HM YEUNG, ES AF PANG, HM YEUNG, ES TI MONITORING OF FORMATION RATES OF THIN-FILMS IN LASER-INDUCED CHEMICAL VAPOR-DEPOSITION SO ANALYTICAL CHEMISTRY LA English DT Article ID METAL-FILMS; GAS-PHASE; PHOTODEPOSITION; DISSOCIATION; CARBONYLS AB Acoustic analysis for in situ laser-induced chemical vapor thin-film deposition is described. It shows that the transient acoustic signal due to the density changes from the photodissociation process can be used to monitor the deposition rate. The acoustic signal is compared with transmittance, reflectance, and quartz crystal microbalance measurements. The observed deposition rate at the initial moment of film formation is also examined by photoacoustic measurements. The contributions from surface absorption and surface-induced dissociation can thus be assessed independently. C1 IOWA STATE UNIV SCI & TECHNOL,US DOE,AMES LAB,AMES,IA 50011. IOWA STATE UNIV SCI & TECHNOL,DEPT CHEM,AMES,IA 50011. NR 15 TC 3 Z9 3 U1 0 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 NOV 1 PY 1991 VL 63 IS 21 BP 2402 EP 2406 DI 10.1021/ac00021a004 PG 5 WC Chemistry, Analytical SC Chemistry GA GM571 UT WOS:A1991GM57100005 ER PT J AU LOO, JA EDMONDS, CG SMITH, RD AF LOO, JA EDMONDS, CG SMITH, RD TI TANDEM MASS-SPECTROMETRY OF VERY LARGE MOLECULES - SERUM-ALBUMIN SEQUENCE INFORMATION FROM MULTIPLY CHARGED IONS FORMED BY ELECTROSPRAY IONIZATION SO ANALYTICAL CHEMISTRY LA English DT Article ID AMINO-ACID SEQUENCE; COLLISION-INDUCED DECOMPOSITION; CYTOCHROME-C; 000 DALTON; PROTEINS; PEPTIDE; SPECTRA; DESORPTION; ELECTROPHORESIS; DISSOCIATION AB Serum albumin proteins, M(r) approximately 66 kDa, from 10 different species (bovine, human, rat, horse, sheep, goat, rabbit, dog, porcine, and guinea pig) have been studied by electrospray ionization mass spectrometry (ESI-MS) and tandem MS using a triple-quadrupole instrument. The effectiveness of collisional activation for the multiply charged albumin ions greatly exceeds that for singly charged ions, allowing an extension by a factor of at least 20 to the molecular mass range for obtaining sequence-specific product ions by tandem MS. Efficient dissociation is largely attributed to "preheating" in the interface Coulombic instability and the large number of collisions. Increasing the electric field In the intermediate pressure region, between the nozzle-skimmer elements of the atmospheric pressure/vacuum interface, allows fragmentation of the multiply protonated (to 96+) molecules produced by ESI. The most abundant dissociation product ions assigned have a low charge state (2+ to 5+) and are attributed to "b(n)" mode species from cleavage of the -CO-N- peptide backbone bonds. Particularly abundant dissociation products originate from regions near residues n = 20-25 from the NH2 terminus for parent ions of moderate charge (approximately 50+). Collisionally activated dissociation (CAD) mass spectra from porcine serum albumin, in contrast to the other albumins, also gave prominent singly charged "y(n)" fragments formed from cleavages near the COOH terminus. Tandem mass spectrometry (MS/MS) of the multiply charged molecular ions, and of fragment species produced by dissociation in the interface (i.e., effective MS/MS/MS), produced similar "b(n)" species and served to confirm spectral assignments. We also show that ESI mass spectra allow a qualitative assessment of protein microheterogeneity and, in some cases, resolution of major contributions. The physical and analytical implications of the results are discussed, including the identification of possible errors in previously published sequences. C1 PACIFIC NW LAB, DEPT CHEM SCI, RICHLAND, WA 99352 USA. RI Smith, Richard/J-3664-2012 OI Smith, Richard/0000-0002-2381-2349 FU NHGRI NIH HHS [HG 00327] NR 67 TC 187 Z9 190 U1 1 U2 16 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 SN 0003-2700 J9 ANAL CHEM JI Anal. Chem. PD NOV 1 PY 1991 VL 63 IS 21 BP 2488 EP 2499 DI 10.1021/ac00021a018 PG 12 WC Chemistry, Analytical SC Chemistry GA GM571 UT WOS:A1991GM57100019 PM 1763807 ER PT J AU BOESE, R HUFFMAN, MA VOLLHARDT, KPC AF BOESE, R HUFFMAN, MA VOLLHARDT, KPC TI UNIQUE REACTIVITY OF HETERODINUCLEAR PENTACARBONYL(FULVALENE)MOLYBDENUMRUTHENIUM WITH ALKYNES - FLUXIONALITY, REARRANGEMENTS, STRUCTURES, AND 1ST REVERSIBLE CONVERSION OF A SIDE-ON - TO A SEMI-BRIDGING ALKENYLIDENE LIGAND SO ANGEWANDTE CHEMIE-INTERNATIONAL EDITION IN ENGLISH LA English DT Article ID MU-VINYLIDENE; COMPLEXES; DINUCLEAR; CARBONYLS; CHEMISTRY; RUTHENIUM AB Acting as as two- and four-electron donors alkynes react with the heteronuclear fulvalene complex 1. Terminally bound alkyne ligands rearrange to alkenylidene ligands; in the course of the reaction an equilibrium between the side-on and semibridging coordination (2 reversible 3) can be observed. (2: R1 = C6H5, R2 = H). C1 UNIV CALIF BERKELEY,LAWRENCE BERKELEY LAB,DIV CHEM SCI,BERKELEY,CA 94720. UNIV ESSEN GESAMTHSCH,INST ANORGAN CHEM,W-4300 ESSEN 1,GERMANY. RP BOESE, R (reprint author), UNIV CALIF BERKELEY,DEPT CHEM,BERKELEY,CA 94720, USA. NR 19 TC 21 Z9 21 U1 0 U2 2 PU VCH PUBLISHERS INC PI DEERFIELD BEACH PA 303 NW 12TH AVE, DEERFIELD BEACH, FL 33442-1788 SN 0570-0833 J9 ANGEW CHEM INT EDIT JI Angew. Chem.-Int. Edit. Engl. PD NOV PY 1991 VL 30 IS 11 BP 1463 EP 1465 DI 10.1002/anie.199114631 PG 3 WC Chemistry, Multidisciplinary SC Chemistry GA GW832 UT WOS:A1991GW83200010 ER PT J AU MYERS, WD SWIATECKI, WJ AF MYERS, WD SWIATECKI, WJ TI A THOMAS-FERMI MODEL OF NUCLEI .2. FISSION-BARRIERS AND CHARGE-DISTRIBUTIONS SO ANNALS OF PHYSICS LA English DT Article ID DEFORMED-NUCLEI; MASS FORMULA; SCATTERING RP MYERS, WD (reprint author), UNIV CALIF BERKELEY,LAWRENCE BERKELEY LAB,DIV NUCL SCI,1 CYCLOTRON RD,BERKELEY,CA 94720, USA. NR 20 TC 24 Z9 24 U1 1 U2 1 PU ACADEMIC PRESS INC JNL-COMP SUBSCRIPTIONS PI SAN DIEGO PA 525 B ST, STE 1900, SAN DIEGO, CA 92101-4495 SN 0003-4916 J9 ANN PHYS-NEW YORK JI Ann. Phys. PD NOV 1 PY 1991 VL 211 IS 2 BP 292 EP 315 DI 10.1016/0003-4916(91)90207-O PG 24 WC Physics, Multidisciplinary SC Physics GA GM644 UT WOS:A1991GM64400005 ER PT J AU NIEVES, RA ELLIS, RP TODD, RJ JOHNSON, TJA GROHMANN, K HIMMEL, ME AF NIEVES, RA ELLIS, RP TODD, RJ JOHNSON, TJA GROHMANN, K HIMMEL, ME TI VISUALIZATION OF TRICHODERMA-REESEI CELLOBIOHYDROLASE-I AND ENDOGLUCANASE-I ON ASPEN CELLULOSE BY USING MONOCLONAL ANTIBODY-COLLOIDAL GOLD CONJUGATES SO APPLIED AND ENVIRONMENTAL MICROBIOLOGY LA English DT Article ID 1,4-BETA-D-GLUCAN CELLOBIOHYDROLASE; ENZYMATIC-HYDROLYSIS; CELLULASES; ADSORPTION; SYNERGISM; DEGRADATION; ENZYMES AB Monoclonal antibodies (MAbs) specific for cellobiohydrolase I (CBH I) and endoglucanase I (EG I) were conjugated to 10- and 15-nm colloidal gold particles, respectively. The binding of CBH I and EG I was visualized by utilizing the MAb-colloidal gold probes. The visualization procedure involved immobilization of cellulose microfibrils on copper electron microscopy grids, incubation of the cellulose-coated grids with cellulase(s), binding of MAb-colloidal gold conjugates to cellulase(s), and visualization via transmission electron microscopy. CBH I was seen bound to apparent crystalline cellulose as well as apparent amorphous cellulose. EG I was seen bound extensively to apparent amorphous cellulose with minimal binding to crystalline cellulose. C1 COLORADO STATE UNIV,COLL VET MED & BIOMED SCI,DEPT ANAT & NEUROBIOL,FT COLLINS,CO 80523. COLORADO STATE UNIV,COLL VET MED & BIOMED SCI,DEPT MICROBIOL,FT COLLINS,CO 80523. RP NIEVES, RA (reprint author), SOLAR ENERGY RES INST,DIV FUELS & CHEM RES & ENGN,BIOTECHNOL RES BRANCH,1617 COLE BLVD,GOLDEN,CO 80401, USA. NR 27 TC 24 Z9 24 U1 1 U2 4 PU AMER SOC MICROBIOLOGY PI WASHINGTON PA 1325 MASSACHUSETTS AVENUE, NW, WASHINGTON, DC 20005-4171 SN 0099-2240 J9 APPL ENVIRON MICROB JI Appl. Environ. Microbiol. PD NOV PY 1991 VL 57 IS 11 BP 3163 EP 3170 PG 8 WC Biotechnology & Applied Microbiology; Microbiology SC Biotechnology & Applied Microbiology; Microbiology GA GN265 UT WOS:A1991GN26500016 PM 16348581 ER PT J AU DORR, MR AF DORR, MR TI A DOMAIN DECOMPOSITION PRECONDITIONER WITH REDUCED RANK INTERDOMAIN COUPLING SO APPLIED NUMERICAL MATHEMATICS LA English DT Article AB A preconditioner for the conjugate gradient solution of the linear system arising from a standard finite element discretization of a self-adjoint, second-order elliptic problem is proposed. To achieve an efficient implementation on multiprocessors, the preconditioner employs a domain decomposition strategy designed to substantially reduce the amount of interdomain (and therefore interprocessor) communication required to invert the preconditioner against the residual vector in each conjugate gradient iteration. A spectral equivalence result and some numerical experiments are presented. RP DORR, MR (reprint author), UNIV CALIF LAWRENCE LIVERMORE NATL LAB,POB 808,L-316,LIVERMORE,CA 94550, USA. NR 9 TC 6 Z9 6 U1 0 U2 0 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0168-9274 J9 APPL NUMER MATH JI Appl. Numer. Math. PD NOV PY 1991 VL 8 IS 4-5 BP 333 EP 352 DI 10.1016/0168-9274(91)90073-9 PG 20 WC Mathematics, Applied SC Mathematics GA GU875 UT WOS:A1991GU87500004 ER PT J AU TESAR, A FUCHS, B HED, P AF TESAR, A FUCHS, B HED, P TI IMPROVEMENT IN POLISHING OF FUSED-SILICA PARTS SO APPLIED OPTICS LA English DT Editorial Material AB High-power laser optics can require high-quality polished surfaces for damage resistance. Fabrication efficiency for producing quality surfaces becomes an important cost consideration. Our systematic study of fused-silica polishing conditions has led to the discovery that enhanced removal efficiency and higher quality optical surfaces can be achieved by decreasing the cerium oxide polishing slurry pH to 4. Both hydrochloric acid and citric acid have been used to lower the slurry pH with equal success. RP TESAR, A (reprint author), LAWRENCE LIVERMORE NATL LAB,POB 5508,L-462,LIVERMORE,CA 94551, USA. NR 0 TC 1 Z9 1 U1 0 U2 2 PU OPTICAL SOC AMER PI WASHINGTON PA 2010 MASSACHUSETTS AVE NW, WASHINGTON, DC 20036 SN 0003-6935 J9 APPL OPTICS JI Appl. Optics PD NOV 1 PY 1991 VL 30 IS 31 BP 4459 EP 4459 PG 1 WC Optics SC Optics GA GT889 UT WOS:A1991GT88900001 PM 20717224 ER PT J AU KOIKE, M MITANI, S NAMIOKA, T AF KOIKE, M MITANI, S NAMIOKA, T TI EXTENDED RAYLEIGH-FANO THEORY AND ITS APPLICATION TO GRATING POLARIZATION SO APPLIED OPTICS LA English DT Article DE GRATING POLARIZATION AB A simple method of calculating the degree of polarization of light diffracted by a grating having shallow grooves and finite conductivity has been developed by extending the Rayleigh-Fano theory. Its validity is examined by comparing the computed degree of polarization with the experimental data obtained in the visible and vacuum ultraviolet for the +/- 1st and -2nd orders of Al- and Au-coated blazed gratings and holographic gratings used in the specific mountings. The calculations are in good agreement with the observed polarization behavior of the gratings, verifying the usefulness of the present method. C1 OSAKA CITY UNIV,DEPT ELECT ENGN,SUMIYOSHI KU,OSAKA 558,JAPAN. TOHOKU UNIV,SCI MEASUREMENTS RES INST,AOBA KU,SENDAI,MIYAGI 980,JAPAN. RP KOIKE, M (reprint author), UNIV CALIF BERKELEY,LAWRENCE BERKELEY LAB,CTR XRAY OPT,1 CYCLOTRON RD,BERKELEY,CA 94720, USA. NR 16 TC 2 Z9 2 U1 0 U2 1 PU OPTICAL SOC AMER PI WASHINGTON PA 2010 MASSACHUSETTS AVE NW, WASHINGTON, DC 20036 SN 0003-6935 J9 APPL OPTICS JI Appl. Optics PD NOV 1 PY 1991 VL 30 IS 31 BP 4528 EP 4536 PG 9 WC Optics SC Optics GA GT889 UT WOS:A1991GT88900021 PM 20717245 ER PT J AU SAPPEY, AD GAMBLE, TK AF SAPPEY, AD GAMBLE, TK TI LASER-FLUORESCENCE DIAGNOSTICS FOR CONDENSATION IN LASER-ABLATED COPPER PLASMAS SO APPLIED PHYSICS B-PHOTOPHYSICS AND LASER CHEMISTRY LA English DT Article ID CLUSTERS; SPECTROSCOPY AB We are investigating the thermodynamic conditions under which condensation occurs in laser ablated copper plasma plumes. The plasma is created by XeCl excimer laser ablation (308 nm, 300 mJ/pulse) at power densities from 500-1000 MW/cm2 into backing pressures of helium in the range 0-50 torr. We use laser-induced fluorescence (LIF) to probe velocity and relative density of both atomic copper and the copper dimer molecule, Cu2, which is formed during condensation onset. At low pressure (10 mtorr), the atomic Cu velocity peaks at approximately 2 x 10(6) cm/s. Copper dimer time-of-flight data suggest that condensation onset occurs after the Cu atoms have slowed very significantly. Excitation scans of the Cu2A-X (0,0) and (1,1) bands yield a rotational and vibrational temperature in the neighborhood of 300 K for all conditions studied. Such low temperatures support the theory that Cu2 is formed under thermally and translationally cold conditions. Direct laser beam absorption is used to determine the number density of atomic copper. Typical densities attained with 5 torr of helium backing gas are 6-8 x 10(13) cm-3. Rayleigh scattering from particulate is easily observable under conditions favorable to particulate production. RP SAPPEY, AD (reprint author), UNIV CALIF LOS ALAMOS SCI LAB,DIV CHEM & LASER SCI,CLS-3,LOS ALAMOS,NM 87545, USA. NR 16 TC 27 Z9 27 U1 0 U2 2 PU SPRINGER VERLAG PI NEW YORK PA 175 FIFTH AVE, NEW YORK, NY 10010 SN 0721-7269 J9 APPL PHYS B-PHOTO PD NOV-DEC PY 1991 VL 53 IS 5-6 BP 353 EP 361 DI 10.1007/BF00331827 PG 9 WC Physics, Applied SC Physics GA GV789 UT WOS:A1991GV78900016 ER PT J AU WIEDERIN, DR HOUK, RS AF WIEDERIN, DR HOUK, RS TI MEASUREMENTS OF AEROSOL-PARTICLE SIZES FROM A DIRECT INJECTION NEBULIZER SO APPLIED SPECTROSCOPY LA English DT Article DE EMISSION SPECTROSCOPY; INSTRUMENTATION, EMISSION SPECTROSCOPY; INSTRUMENTATION, NEBULIZERS ID ATOMIC EMISSION-SPECTROMETRY; LIQUID-CHROMATOGRAPHY; PNEUMATIC NEBULIZERS; SAMPLE INTRODUCTION; PLASMA; SPECTROSCOPY; SPRAY AB Photographs and laser-scattering measurements showed that a direct injection nebulizer (DIN) produced a finer aerosol with a narrower drop size distribution than that for a conventional glass concentric nebulizer when both were operated at the same liquid and nebulizer gas flow rates. The droplets from the DIN were slightly larger, however, than those leaving a Scott-type spray chamber with a glass concentric nebulizer. The droplets from the DIN had a Sauter mean diameter of approximately 7-mu-m and a 90% mass diameter of 11-16-mu-m. The droplet size distribution became narrower and shifted to lower diameters as the aerosol gas flow rate increased. C1 IOWA STATE UNIV SCI & TECHNOL,US DOE,AMES LAB,DEPT CHEM,AMES,IA 50011. NR 18 TC 43 Z9 43 U1 0 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 NOV PY 1991 VL 45 IS 9 BP 1408 EP 1412 DI 10.1366/0003702914335481 PG 5 WC Instruments & Instrumentation; Spectroscopy SC Instruments & Instrumentation; Spectroscopy GA GR646 UT WOS:A1991GR64600004 ER PT J AU LEWIS, KB OYAMA, ST SOMORJAI, GA AF LEWIS, KB OYAMA, ST SOMORJAI, GA TI TPD STUDIES OF VANADIUM-OXIDE FILMS DEPOSITED ON GOLD SO APPLIED SURFACE SCIENCE LA English DT Article ID SURFACE-PROPERTIES; METAL-OXIDES; V2O5; OXIDATION; PENTOXIDE AB Temperature-programmed desorption (TPD) can be used to study reactions on vanadium oxide films deposited onto gold foil by evaporation. Scanning electron microscopy, X-ray diffraction, laser Raman spectroscopy, and Auger electron spectroscopy reveal that these films consist of micron-sized crystallites of fully oxidized V2O5. In vacuum, molecular O2 desorbs from the films above 775 K, a temperature at which surface oxygen lost through desorption can be replaced through surface segregation of bulk oxygen. However, after activated hydrogen is adsorbed, surface oxygen can be removed at much lower temperatures as H2O. Water desorbs at 425 K without leaving surface oxygen vacancies. After the adsorption of ethanol and ethylene, CO and CO2 are the primary desorption products (peak desorption temperatures at 670-720 K) although small amounts of acetaldehyde are also observed. This behaviour is related to that found in the catalytic oxidation of ethanol. C1 UNIV CALIF BERKELEY,DEPT CHEM,BERKELEY,CA 94720. UNIV WASHINGTON,DEPT CHEM ENGN,SEATTLE,WA 98195. UNIV WASHINGTON,CTR BIOENGN,SEATTLE,WA 98195. CLARKSON UNIV,DEPT CHEM ENGN & CHEM,POTSDAM,NY 13699. UNIV CALIF BERKELEY,LAWRENCE BERKELEY LAB,DIV CHEM SCI,BERKELEY,CA 94720. NR 19 TC 11 Z9 11 U1 3 U2 14 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0169-4332 J9 APPL SURF SCI JI Appl. Surf. Sci. PD NOV PY 1991 VL 52 IS 3 BP 241 EP 248 DI 10.1016/0169-4332(91)90053-M PG 8 WC Chemistry, Physical; Materials Science, Coatings & Films; Physics, Applied; Physics, Condensed Matter SC Chemistry; Materials Science; Physics GA GT307 UT WOS:A1991GT30700008 ER PT J AU DIAMOND, SA NEWMAN, MC MULVEY, M GUTTMAN, SI AF DIAMOND, SA NEWMAN, MC MULVEY, M GUTTMAN, SI TI ALLOZYME GENOTYPE AND TIME-TO-DEATH OF MOSQUITOFISH, GAMBUSIA-HOLBROOKI, DURING ACUTE INORGANIC MERCURY EXPOSURE - A COMPARISON OF POPULATIONS SO AQUATIC TOXICOLOGY LA English DT Article DE FISH; MOSQUITOFISH (GAMBUSIA-HOLBROOKI); MERCURY; HEAVY METAL; GENETICS; TOLERANCE ID POLYCHAETE NEREIS-DIVERSICOLOR; DROSOPHILA-MELANOGASTER; ESTUARINE SEDIMENTS; AFFINIS BAIRD; COPPER; SELECTION; CADMIUM; DEHYDROGENASE; SURVIVORSHIP; FREQUENCIES AB Relationships between enzyme genotype and time-to-death (TTD) during acute mercury exposure were examined in mosquitofish taken from two isolated field populations. Results were compared with those from an exposure conducted two years previously, with fish from one of these populations, in which genotypes at three enzyme loci, Icd-1, Gpi-2, and Mdh-1, were significantly related to TTD, as was overall heterozygosity. Neither genotype nor heterozygosity were related to TTD in the present exposure of fish from this population. In the exposure of fish from the population not sampled previously, two loci, Icd-2 and Mpi, were significantly related to TTD. Multiple locus heterozygosity was not related to mortality in this exposure. These two populations exhibited different genotype-TTD relationships during laboratory exposures, suggesting that the response of one population exposed in the laboratory may not accurately represent the responses of other populations, either in the laboratory or during exposures in nature. C1 UNIV GEORGIA,SAVANNAH RIVER ECOL LAB,AIKEN,SC. RP DIAMOND, SA (reprint author), MIAMI UNIV,DEPT ZOOL,OXFORD,OH 45056, USA. NR 34 TC 29 Z9 30 U1 0 U2 5 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0166-445X J9 AQUAT TOXICOL JI Aquat. Toxicol. PD NOV PY 1991 VL 21 IS 1-2 BP 119 EP 134 DI 10.1016/0166-445X(91)90010-7 PG 16 WC Marine & Freshwater Biology; Toxicology SC Marine & Freshwater Biology; Toxicology GA GR906 UT WOS:A1991GR90600009 ER PT J AU CHRISTIAN, JE AF CHRISTIAN, JE TI ENERGY-EFFICIENT RESIDENTIAL BUILDING FOUNDATIONS SO ASHRAE JOURNAL-AMERICAN SOCIETY OF HEATING REFRIGERATING AND AIR-CONDITIONING ENGINEERS LA English DT Article RP CHRISTIAN, JE (reprint author), OAK RIDGE NATL LAB,BLDG ENVELOPE SYST & MAT PROGRAM,OAK RIDGE,TN, USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU AMER SOC HEAT REFRIG AIR- CONDITIONING ENG INC PI ATLANTA PA 1791 TULLIE CIRCLE NE, ATLANTA, GA 30329 SN 0001-2491 J9 ASHRAE J JI ASHRAE J.-Am. Soc. Heat Refrig. Air-Cond. Eng. PD NOV PY 1991 VL 33 IS 11 BP 36 EP & PG 0 WC Thermodynamics; Construction & Building Technology; Engineering, Mechanical SC Thermodynamics; Construction & Building Technology; Engineering GA GP866 UT WOS:A1991GP86600008 ER PT J AU BAADE, D CRISTIANI, S LANZ, T MALANEY, RA SAHU, KC VLADILO, G AF BAADE, D CRISTIANI, S LANZ, T MALANEY, RA SAHU, KC VLADILO, G TI REDUCED UPPER LIMITS ON THE EQUIVALENT WIDTH OF INTERSTELLAR LI-I-670.8 TOWARDS SN-1987-A SO ASTRONOMY & ASTROPHYSICS LA English DT Article DE INTERSTELLAR MATTER; LARGE MAGELLANIC CLOUD; LITHIUM; PRIMORDIAL NUCLEOSYNTHESIS ID LARGE MAGELLANIC CLOUD; SUPERNOVA 1987A; DIFFUSE CLOUDS; LITHIUM; NUCLEOSYNTHESIS; ABUNDANCES; SPECTRUM; STARS AB A new search for interstellar Li I 670.8 along the line of sight to SN 1987A has been carried out using all 34 known (and previously published) high-resolution Reticon spectra obtained at the European Southern Observatory. In spite of the large number and high quality of the observations, the line remains undetected even in the carefully weighted and filtered mean spectrum. The most probable 3-sigma detection limit in equivalent width is 7.3 10(-6) nm. For the cloud at radial velocity + 286 km s-1, standard relations then imply a maximum abundance, Li/H, of 1.7 10(-11) in the gaseous interstellar medium of the LMC. If depletion to dust grains is the same for both lithium and potassium, this figure has to be increased by 1.1 dex. Accordingly. conventional present-day reasoning suggests that the elemental abundance of lithium does not exceed 2.7 10(-10). However, the cumulative uncertainties are such that a primordial abundance which is an order of magnitude higher is not firmly ruled out. Constraints on primordial nucleosynthesis models are, therefore, only weak. C1 UNIV PADUA, DIPARTIMENTO ASTRON, I-35122 PADUA, ITALY. UNIV LAUSANNE, INST ASTRON, CH-1290 CHAVANNES DES BOIS, SWITZERLAND. KAPTEYN LAB, 9700 AV GRONINGEN, NETHERLANDS. OSSERV ASTRON TRIESTE, I-34131 TRIESTE, ITALY. UNIV CALIF LAWRENCE LIVERMORE NATL LAB, INST GEOPHYS & PLANETARY PHYS, LIVERMORE, CA 94550 USA. RP BAADE, D (reprint author), EUROPEAN SO OBSERV, KARL SCHWARZSCHILD STR 2, W-8046 GARCHING, GERMANY. RI Malaney, Robert/F-6588-2012; OI Malaney, Robert/0000-0001-9672-5601; Cristiani, Stefano/0000-0002-2115-5234; Vladilo, Giovanni/0000-0001-7604-8332 NR 23 TC 5 Z9 5 U1 0 U2 0 PU EDP SCIENCES S A PI LES ULIS CEDEX A PA 17, AVE DU HOGGAR, PA COURTABOEUF, BP 112, F-91944 LES ULIS CEDEX A, FRANCE SN 0004-6361 J9 ASTRON ASTROPHYS JI Astron. Astrophys. PD NOV PY 1991 VL 251 IS 1 BP 253 EP 258 PG 6 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA GM776 UT WOS:A1991GM77600031 ER PT J AU WRIGHT, EL MATHER, JC BENNETT, CL CHENG, ES SHAFER, RA FIXSEN, DJ EPLEE, RE ISAACMAN, RB READ, SM BOGGESS, NW GULKIS, S HAUSER, MG JANSSEN, M KELSALL, T LUBIN, PM MEYER, SS MOSELEY, SH MURDOCK, TL SILVERBERG, RF SMOOT, GF WEISS, R WILKINSON, DT AF WRIGHT, EL MATHER, JC BENNETT, CL CHENG, ES SHAFER, RA FIXSEN, DJ EPLEE, RE ISAACMAN, RB READ, SM BOGGESS, NW GULKIS, S HAUSER, MG JANSSEN, M KELSALL, T LUBIN, PM MEYER, SS MOSELEY, SH MURDOCK, TL SILVERBERG, RF SMOOT, GF WEISS, R WILKINSON, DT TI PRELIMINARY SPECTRAL OBSERVATIONS OF THE GALAXY WITH A 7-DEGREES BEAM BY THE COSMIC BACKGROUND EXPLORER (COBE) SO ASTROPHYSICAL JOURNAL LA English DT Article DE INFRARED, SPECTRA; INTERSTELLAR, GRAINS; INTERSTELLAR, MATTER; INTERSTELLAR, MOLECULES ID C-II EMISSION; INTERSTELLAR-MEDIUM; MOLECULAR CLOUDS; GALACTIC PLANE; ATOMIC CARBON; 158 MICRON; LINE; REGIONS; DUST; TEMPERATURE AB The far-infrared absolute spectrophotometer (FIRAS) on the Cosmic Background Explorer (COBE) has carried out the first all-sky spectral line survey in the far-infrared region, as well as mapping spectra of the Galactic dust distribution at lambda > 100-mu-m. Lines of [C I], [C II], [N II], and CO are all clearly detected, [C II] (158-mu-m) and [N II] (205.3-mu-m) with sufficient strength to be mapped, and the wavelength of the [N II] line at 205.3-mu-m is determined by observation for the first time. The mean line intensities are interpreted in terms of the heating and cooling of the multiple phases of the interstellar gas. In addition, an average spectrum of the galaxy is constructed and searched for weak lines. The spectrum of the galaxy observed by FIRAS has two major components: a continuous spectrum due to interstellar dust heated by starlight with a total luminosity of (1.8 +/- 0.6)(R0/8.5 kpc)2 x 10(10) L. within the solar circle; and a line spectrum dominated by the strong 158-mu-m line from singly ionized carbon, with a spatial distribution similar to the dust distribution, and a luminosity of 0.3% of the dust luminosity. There are in addition moderately strong 122 and 205.3-mu-m lines, identified as coming from singly ionized nitrogen, which contribute 0.04% and 0.03% of the total dust luminosity. The much weaker lines of neutral carbon at 370 and 609-mu-m are seen, as are the 2-1 through 5-4 CO lines. These low-J CO lines contribute 0.003% of the total dust luminosity. Maps of the emission by dust, [C II], and [N II] are presented. C1 NASA,GODDARD SPACE FLIGHT CTR,GREENBELT,MD 20771. NASA,GODDARD SPACE FLIGHT CTR,UNIV SPACE RES ASSOC,GREENBELT,MD 20771. NASA,GODDARD SPACE FLIGHT CTR,GEN SCI CORP,GREENBELT,MD 20771. ST SYST CORP,LANHAM,MD 20706. CALTECH,JET PROP LAB,PASADENA,CA 91109. UNIV CALIF SANTA BARBARA,DEPT PHYS,SANTA BARBARA,CA 93106. MIT,DEPT PHYS,CAMBRIDGE,MA 02139. GEN RES CORP,DANVERS,MA 01923. UNIV CALIF BERKELEY,LAWRENCE BERKELEY LAB,BERKELEY,CA 94720. UNIV CALIF BERKELEY,SSL,BERKELEY,CA 94720. PRINCETON UNIV,DEPT PHYS,PRINCETON,NJ 08544. RP WRIGHT, EL (reprint author), UNIV CALIF LOS ANGELES,DEPT ASTRON,LOS ANGELES,CA 90024, USA. RI Moseley, Harvey/D-5069-2012 NR 46 TC 350 Z9 350 U1 0 U2 4 PU UNIV CHICAGO PRESS PI CHICAGO PA 5720 S WOODLAWN AVE, CHICAGO, IL 60637 SN 0004-637X J9 ASTROPHYS J JI Astrophys. J. PD NOV 1 PY 1991 VL 381 IS 1 BP 200 EP 209 DI 10.1086/170641 PN 1 PG 10 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA GM575 UT WOS:A1991GM57500019 ER PT J AU VANTURE, AD WALLERSTEIN, G BROWN, JA BAZAN, G AF VANTURE, AD WALLERSTEIN, G BROWN, JA BAZAN, G TI ABUNDANCES OF TC AND RELATED ELEMENTS IN STARS OF TYPE-M, TYPE-MS, AND TYPE-S SO ASTROPHYSICAL JOURNAL LA English DT Article DE NUCLEOSYNTHESIS; STARS, ABUNDANCES; STARS, LATE-TYPE; STARS, LONG-PERIOD VARIABLES; STARS, SEMIREGULAR ID ASYMPTOTIC GIANT BRANCH; RED GIANTS; TECHNETIUM ABUNDANCES; CHEMICAL-COMPOSITION; DREDGE-UP; ATMOSPHERES; ZIRCONIUM; EVOLUTION; LITHIUM; SOLAR AB Abundances of Co, Zr, Nb, and Tc relative to V have been derived for a sample of ten M and MS stars from 0.10 angstrom pixel-1 and 0.04 angstrom pixel-1 Reticon spectra. On a scale with log N(H) = 12.0 and log N(V) = 4.0, we find log N(Tc) almost-equal-to 1.4 for M stars and 1.0 for MS stars with Tc. It has been suggested by Dominy and Wallerstein that the presence of Tc in M stars which show no enhancements of other s-process elements can be explained by a "mini s-process". Detailed calculations and the observed abundances of Tc and related elements presented in this study put this interpretation in doubt. Our observations also fail to support the alternative hypothesis suggested by Malaney and Lattanzio that Tc is produced by the photofission of Th and U. C1 UNIV ILLINOIS, DEPT ASTRON, URBANA, IL 61801 USA. UNIV CALIF LAWRENCE LIVERMORE NATL LAB, DIV E, LIVERMORE, CA 94550 USA. RP UNIV WASHINGTON, DEPT ASTRON FM20, SEATTLE, WA 98195 USA. NR 37 TC 15 Z9 15 U1 0 U2 2 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 NOV 1 PY 1991 VL 381 IS 1 BP 278 EP 287 DI 10.1086/170649 PN 1 PG 10 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA GM575 UT WOS:A1991GM57500027 ER PT J AU GUZIK, JA COX, AN AF GUZIK, JA COX, AN TI EFFECTS OF OPACITY AND EQUATION OF STATE ON SOLAR STRUCTURE AND OSCILLATIONS SO ASTROPHYSICAL JOURNAL LA English DT Article DE EQUATION OF STATE; OPACITIES; SUN, INTERIOR; SUN, OSCILLATIONS ID STELLAR ENVELOPES; FREQUENCIES; INTERIOR; MODELS; TABLES AB The volution and p-mode oscillation frequencies of several solar models are presented, highlighting the effects of uncertainties in the opacity and equation of state. We have incorporated the Dappen, Mihalas, Hummer, and Mihalas ("MHD") equation of state tables into our evolution and oscillation calculations, and compared results with those of models calculated using the analytical Iben equation of state. The nonadiabatic low-degree p-mode oscillation frequencies derived from models using either of these equations of state agree with observations to within a few microhertz. The MHD equation of state, with more detailed treatment of envelope ionization regions, improves agreement with observations for p-modes of degree l = 40-300. For higher degree p-modes, observational uncertainties make it difficult to determine how much improvement the MHD equation of state provides over the analytical Iben procedure. We incorporated small opacity increases (10%-15%) in the 2-5 million K temperature region below the bottom of the convection zone, as indicated by the new Iglesias and Rogers Livermore opacities, to adjust the convection zone depth and fine-tune agreement between calculated and observed p-mode frequencies. We also find that calculated p-mode oscillation frequencies favor the higher Ross-Aller opacities, which include molecular effects and more iron lines, over the older Cox-Tabor opacities in the solar envelope at temperature below 9000 K. Thus, solar oscillations can be effectively used to constrain opacities at the solar surface and below the convection zone. C1 UNIV CALIF LOS ALAMOS SCI LAB,DIV THEORET PHYS,LOS ALAMOS,NM 87545. RP GUZIK, JA (reprint author), UNIV CALIF LOS ALAMOS SCI LAB,DIV APPL THEORET PHYS,X-2,MS B220,LOS ALAMOS,NM 87545, USA. NR 32 TC 27 Z9 27 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 NOV 1 PY 1991 VL 381 IS 1 BP 333 EP 340 DI 10.1086/170655 PN 1 PG 8 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA GM575 UT WOS:A1991GM57500033 ER PT J AU DEAMICI, G BERSANELLI, M KOGUT, A LEVIN, S LIMON, M SMOOT, GF AF DEAMICI, G BERSANELLI, M KOGUT, A LEVIN, S LIMON, M SMOOT, GF TI THE TEMPERATURE OF THE COSMIC MICROWAVE BACKGROUND-RADIATION AT 3.8 GHZ - RESULTS OF A MEASUREMENT FROM THE SOUTH-POLE SITE SO ASTROPHYSICAL JOURNAL LA English DT Article DE COSMIC BACKGROUND RADIATION; EARTH, ATMOSPHERE ID SPECTRUM; WAVELENGTH AB As part of an international collaboration to measure the low-frequency spectrum of the cosmic microwave background (CMB) radiation, we have measured its temperature at a frequency of 3.8 GHz (7.9 cm wavelength), during the austral spring of 1989, obtaining a brightness temperature, T(CMB), of 2.64 +/- 0.07 K (68% confidence level). The new result is in agreement with our previous measurements at the same frequency obtained in 1986-88 from a very different site and has comparable error bars. Combining measurements from all years we obtain T(CMB) = 2.64 +/- 0.06 K. C1 UNIV CALIF BERKELEY, LAWRENCE BERKELEY LAB, BERKELEY, CA 94720 USA. CNR, IFC, I-20133 MILAN, ITALY. NASA, GODDARD SPACE FLIGHT CTR, ASTRON & SOLAR PHYS LAB, GREENBELT, MD 20771 USA. RP UNIV CALIF BERKELEY, SPACE SCI LAB, M-S 50-232, BERKELEY, CA 94720 USA. NR 19 TC 27 Z9 27 U1 0 U2 0 PU IOP PUBLISHING LTD PI BRISTOL PA TEMPLE CIRCUS, TEMPLE WAY, BRISTOL BS1 6BE, ENGLAND SN 0004-637X EI 1538-4357 J9 ASTROPHYS J JI Astrophys. J. PD NOV 1 PY 1991 VL 381 IS 1 BP 341 EP 347 DI 10.1086/170656 PN 1 PG 7 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA GM575 UT WOS:A1991GM57500034 ER PT J AU TAVANI, M BROOKSHAW, L AF TAVANI, M BROOKSHAW, L TI OUTFLOW HYDRODYNAMICS IN THE ECLIPSING MILLISECOND PULSAR BINARIES PSR 1957+20 AND PSR 1744-24A SO ASTROPHYSICAL JOURNAL LA English DT Article DE HYDRODYNAMICS; PULSARS; SHOCK WAVES; STARS, ECLIPSING BINARIES ID X-RAY BINARIES; EVOLUTION; TERZAN-5; MODEL AB We present results of a two-dimensional calculation of the hydrodynamic wind outflow for the two eclipsing millisecond pulsar binaries PSR 1957 + 20 and PSR 1744-24A. The calculation includes pressure forces as an essential part of the wind hydrodynamics, and the wind material is assumed to be optically thick to pulsar radiation. We show that a shock forms where the gas outflowing from the companion star interacts with pulsar radiation. The eclipse shape is dependent on the possibly time-variable thermal and kinematic state of the outflowing gas. We present here results for a particular time chosen to represent important qualitative features of the outflow. The results of the simulations can be used to valuably constrain models for the formation of pulsar eclipses and mass outflow for star-vaporizing millisecond pulsars. C1 UNIV CALIF BERKELEY,DEPT ASTRON,BERKELEY,CA 94720. UNIV CALIF SANTA BARBARA,INST THEORET PHYS,SANTA BARBARA,CA 93106. RP TAVANI, M (reprint author), UNIV CALIF LAWRENCE LIVERMORE NATL LAB,INST GEOPHYS & PLANETARY PHYS,L-413,LIVERMORE,CA 94550, USA. NR 29 TC 17 Z9 17 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 NOV 1 PY 1991 VL 381 IS 1 BP L21 EP L24 DI 10.1086/186187 PN 2 PG 4 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA GM577 UT WOS:A1991GM57700006 ER PT J AU NARAYANAMURTI, V ARVIZU, DE AF NARAYANAMURTI, V ARVIZU, DE TI USING SANDIA TECHNOLOGIES TO IMPROVE NATIONAL COMPETITIVENESS SO AT&T TECHNICAL JOURNAL LA English DT Article AB Sandia National Laboratories was established in 1945 to provide engineering support for the United States nuclear deterrence program. Technologies developed for that and other federal programs are coupled with Sandia's industrial management roots. Together, they have resulted in a national laboratory whose systems engineering orientation is based on research and development processes modeled after those of AT&T Bell Laboratories. Recent dramatic changes in international relationships have redirected Sandia's role toward the transfer of its government-sponsored technologies to commercial and industrial applications in the private sector. C1 SANDIA NATL LABS,TECHNOL TRANSFER & IND RELAT,ALBUQUERQUE,NM 87185. RP NARAYANAMURTI, V (reprint author), SANDIA NATL LABS,AREA RES EXPLORATORY TECHNOL,ALBUQUERQUE,NM 87185, USA. NR 7 TC 0 Z9 0 U1 0 U2 0 PU AT&T BELL LABORATORIES PI MURRAY HILL PA 600 MOUNTAIN AVE,RM 3C-417 CIRCULATION GROUP P O BOX 636, MURRAY HILL, NJ 07974-0636 SN 8756-2324 J9 AT&T TECH J JI AT&T Tech. J. PD NOV-DEC PY 1991 VL 70 IS 6 BP 2 EP 9 PG 8 WC Computer Science, Hardware & Architecture; Telecommunications SC Computer Science; Telecommunications GA HA500 UT WOS:A1991HA50000001 ER PT J AU EICKER, PJ MILLER, DJ STRIP, DR AF EICKER, PJ MILLER, DJ STRIP, DR TI INTELLIGENT SYSTEMS AND TECHNOLOGIES FOR MANUFACTURING SO AT&T TECHNICAL JOURNAL LA English DT Article AB Issues as diverse as occupational safety, waste minimization, and product quality are forcing the Department of Energy (DOE) to increase the level of automation in its defense-production facilities. In this paper, we describe the development necessary to allow a specific automation technology-the standard industrial robot-to be used effectively in DOE manufacturing operations. We describe Sandia's research and development efforts on automated planning and programming, and on programming models and languages for "intelligent" manufacturing systems that use robots. We conclude by discussing the application of these concepts to machines and processes other than robots. We also mention how these technologies affect the more general manufacturing-technology base. RP EICKER, PJ (reprint author), SANDIA NATL LABS,DEPT COMP SCI,TECH STAFF,ALBUQUERQUE,NM 87185, USA. NR 16 TC 0 Z9 0 U1 0 U2 0 PU AT&T BELL LABORATORIES PI MURRAY HILL PA 600 MOUNTAIN AVE,RM 3C-417 CIRCULATION GROUP P O BOX 636, MURRAY HILL, NJ 07974-0636 SN 8756-2324 J9 AT&T TECH J JI AT&T Tech. J. PD NOV-DEC PY 1991 VL 70 IS 6 BP 10 EP 22 PG 13 WC Computer Science, Hardware & Architecture; Telecommunications SC Computer Science; Telecommunications GA HA500 UT WOS:A1991HA50000002 ER PT J AU WEISSMAN, SH SEKUTOWSKI, JC AF WEISSMAN, SH SEKUTOWSKI, JC TI ENVIRONMENTALLY CONSCIOUS MANUFACTURING - A TECHNOLOGY FOR THE NINETIES SO AT&T TECHNICAL JOURNAL LA English DT Article AB Environmentally conscious manufacturing involves developing and implementing manufacturing processes that minimize or eliminate hazardous chemical waste, reduce scrap, or are operationally safer. The benefits include safer and cleaner factories, reduced future costs for disposal and worker protection, reduced environmental and health risks, improved product quality at lower cost, and higher productivity. Sandia and AT&T are committed to environmentally conscious manufacturing. C1 AT&T BELL LABS,DEPT ENVIRONM & MAT TECHNOL,PRINCETON,NJ. RP WEISSMAN, SH (reprint author), SANDIA NATL LABS,DIV PROC OPTIMIZAT & CONTROL,ALBUQUERQUE,NM 87185, USA. NR 7 TC 5 Z9 5 U1 0 U2 0 PU AT&T BELL LABORATORIES PI MURRAY HILL PA 600 MOUNTAIN AVE,RM 3C-417 CIRCULATION GROUP P O BOX 636, MURRAY HILL, NJ 07974-0636 SN 8756-2324 J9 AT&T TECH J JI AT&T Tech. J. PD NOV-DEC PY 1991 VL 70 IS 6 BP 23 EP 30 PG 8 WC Computer Science, Hardware & Architecture; Telecommunications SC Computer Science; Telecommunications GA HA500 UT WOS:A1991HA50000003 ER PT J AU JORGENSEN, JL YANEY, DS AF JORGENSEN, JL YANEY, DS TI RADIATION-HARDENED MICROELECTRONICS SO AT&T TECHNICAL JOURNAL LA English DT Article AB Many nuclear power, defense, and space applications require radiation-hardened integrated circuits. In 1986, Sandia's expertise in microelectronics radiation hardening was combined with AT&T's 1.25-micrometer (mu-m) complementary-metal-oxide semiconductor (CMOS) process to develop a new generation of digital designs. These include a 32-bit microprocessor and a 256-kilobit static random access memory (SRAM). This effort is now complete; the new process is running at AT&T's Allentown, Pennsylvania, MOS V production facility, and the technology has been transferred to Sandia's Microelectronics Development Laboratory (MDL) in Albuquerque, New Mexico. By joining their resources and expertise, Sandia and AT&T developed this process at a fraction of what it would have cost if either had attempted it alone. C1 AT&T BELL LABS,DEPT MEMORY TECHNOL DEV,ALLENTOWN,PA 18103. RP JORGENSEN, JL (reprint author), SANDIA NATL LABS,DEPT MULTICHIP & CUSTOM PROD MICROELECTR PROD,ALBUQUERQUE,NM 87185, USA. NR 2 TC 0 Z9 0 U1 0 U2 0 PU AT&T BELL LABORATORIES PI MURRAY HILL PA 600 MOUNTAIN AVE,RM 3C-417 CIRCULATION GROUP P O BOX 636, MURRAY HILL, NJ 07974-0636 SN 8756-2324 J9 AT&T TECH J JI AT&T Tech. J. PD NOV-DEC PY 1991 VL 70 IS 6 BP 31 EP 36 PG 6 WC Computer Science, Hardware & Architecture; Telecommunications SC Computer Science; Telecommunications GA HA500 UT WOS:A1991HA50000004 ER PT J AU STULEN, RH FREEMAN, RR AF STULEN, RH FREEMAN, RR TI DEVELOPING A SOFT-X-RAY PROJECTION LITHOGRAPHY TOOL SO AT&T TECHNICAL JOURNAL LA English DT Article ID REDUCTION AB The circuit-integration densities needed for semiconductor devices in the late 1990s will require advanced patterning technologies that can print line widths of 0.2 micrometers or less. Because it uses shorter wavelengths, X-ray lithography is one of the most promising methods for volume production of such circuits. X-ray projection lithography, which uses reflective optics, offers the added advantage of image reduction. AT&T Bell Laboratories has used X-ray projection lithography for diffraction-limited imaging with 140-angstrom radiation from a synchrotron. Now, Sandia National Laboratories and AT&T Bell Laboratories are developing a soft X-ray projection lithography tool that uses a compact source of X-rays: the laser-plasma source. A possible alternative to the expensive, complex synchrotrons, the laser-plasma source could influence the future commercialization of X-ray projection lithography. This paper describes soft X-ray projection lithography and our progress in combining projection optics at 140 angstroms with a laser-plasma source. C1 SANDIA NATL LABS,DEPT PHYS SCI,LIVERMORE,CA 94550. RP STULEN, RH (reprint author), AT&T BELL LABS,ADV LITHOG RES DEPT,HOLMDEL,NJ 07733, USA. NR 5 TC 0 Z9 0 U1 0 U2 0 PU AT&T BELL LABORATORIES PI MURRAY HILL PA 600 MOUNTAIN AVE,RM 3C-417 CIRCULATION GROUP P O BOX 636, MURRAY HILL, NJ 07974-0636 SN 8756-2324 J9 AT&T TECH J JI AT&T Tech. J. PD NOV-DEC PY 1991 VL 70 IS 6 BP 37 EP 48 PG 12 WC Computer Science, Hardware & Architecture; Telecommunications SC Computer Science; Telecommunications GA HA500 UT WOS:A1991HA50000005 ER PT J AU PEERCY, PS AF PEERCY, PS TI STRAINED-LAYER SEMICONDUCTOR RESEARCH-AND-DEVELOPMENT AT SANDIA SO AT&T TECHNICAL JOURNAL LA English DT Article ID SURFACE-EMITTING LASERS; FIELD-EFFECT TRANSISTOR; QUANTUM-WELL; SUPER-LATTICES; SUPERLATTICE; TEMPERATURE; WAVE AB Sandia National Laboratories pioneered work in strained-layer superlattice systems for electronics and optoelectronics. Based on that work, it now conducts research and development in compound semiconductor and optoelectronics physics, materials science, and device technology. Although Sandia's research relies heavily on theoretical and experimental solid state physics, this paper will emphasize applications that exploit the properties of strained-layer systems. This research allows the microelectronics and photonics community to use the special properties of strained-layer systems in an engineering, rather than an empirical, manner. The number of electronic and optoelectronic devices that depend on strained-layer systems for their highest performance with device applications indicates their importance. Selected strained-layer structures and devices developed at Sandia will be discussed. RP PEERCY, PS (reprint author), SANDIA NATL LABS,MICROELECTR & PHOTON,ALBUQUERQUE,NM 87185, USA. NR 29 TC 0 Z9 0 U1 0 U2 1 PU AT&T BELL LABORATORIES PI MURRAY HILL PA 600 MOUNTAIN AVE,RM 3C-417 CIRCULATION GROUP P O BOX 636, MURRAY HILL, NJ 07974-0636 SN 8756-2324 J9 AT&T TECH J JI AT&T Tech. J. PD NOV-DEC PY 1991 VL 70 IS 6 BP 49 EP 58 PG 10 WC Computer Science, Hardware & Architecture; Telecommunications SC Computer Science; Telecommunications GA HA500 UT WOS:A1991HA50000006 ER PT J AU BENNER, RE HARRIS, JM AF BENNER, RE HARRIS, JM TI APPLICATIONS, ALGORITHMS, AND SOFTWARE FOR MASSIVELY PARALLEL COMPUTING SO AT&T TECHNICAL JOURNAL LA English DT Article AB Sandia National Laboratories has developed massively parallel (MP) software that provides high absolute performance and nearly perfect parallel efficiencies. We have used this software on first- and second-generation 1K-processor hypercubes with more than thousand-fold parallel speedups and supercomputer performance. As we developed MP software, we made significant research advances in parallel numerical methods, such as parallel time stepping. The hardware diagnostic tools and parallel graphics algorithms that we have developed and provided to vendors can pinpoint hardware problems and visualize performance in thousand-processor ensembles. Our distributed-computing software will provide super-computer performance from workstation networks. In collaboration with university and industry researchers in parallel computing, we have proven the concept of distributed parallel supercomputing with parallel computations on a network of VAX(R) computers. (VAX is a registered trademark of Digital Equipment Corporation.) C1 SANDIA NATL LABS,CTR COMPUTAT ENGN,LIVERMORE,CA 94550. RP BENNER, RE (reprint author), SANDIA NATL LABS,DEPT MATH & COMPAT SCI,TECH STAFF,ALBUQUERQUE,NM 87185, USA. NR 31 TC 0 Z9 0 U1 0 U2 0 PU AT&T BELL LABORATORIES PI MURRAY HILL PA 600 MOUNTAIN AVE,RM 3C-417 CIRCULATION GROUP P O BOX 636, MURRAY HILL, NJ 07974-0636 SN 8756-2324 J9 AT&T TECH J JI AT&T Tech. J. PD NOV-DEC PY 1991 VL 70 IS 6 BP 59 EP 72 PG 14 WC Computer Science, Hardware & Architecture; Telecommunications SC Computer Science; Telecommunications GA HA500 UT WOS:A1991HA50000007 ER PT J AU BRICKELL, EF MCCURLEY, KS AF BRICKELL, EF MCCURLEY, KS TI INTERACTIVE IDENTIFICATION AND DIGITAL-SIGNATURES SO AT&T TECHNICAL JOURNAL LA English DT Article ID SCHEME AB An interactive identification scheme is a method for remotely (or locally) verifying an individual's identity. Interaction prevents the person who is doing the verifying from collecting information that could be used later to impersonate the individual. It also prevents anyone else from gaining such information. Interactive identification schemes have many potential applications-from providing more secure remote computer logins to providing more secure bank-card transactions. Such schemes can also be used to construct digital signatures, a way of signing an electronic document that makes the signature easy to check but difficult for an unauthorized person to forge. In this paper, we describe the general problems of identification and signatures, explain some shortcomings of current methods, and discuss how interactive identification schemes address them. We also describe an interactive identification scheme discovered at Sandia National Laboratories in which the security is based on the computational difficulty of solving two hard problems. RP BRICKELL, EF (reprint author), SANDIA NATL LABS,DEPT MATH & COMPUTAT SCI,DIV COMP SCI,TECH STAFF,ALBUQUERQUE,NM 87185, USA. NR 26 TC 1 Z9 1 U1 0 U2 0 PU AT&T BELL LABORATORIES PI MURRAY HILL PA 600 MOUNTAIN AVE,RM 3C-417 CIRCULATION GROUP P O BOX 636, MURRAY HILL, NJ 07974-0636 SN 8756-2324 J9 AT&T TECH J JI AT&T Tech. J. PD NOV-DEC PY 1991 VL 70 IS 6 BP 73 EP 86 PG 14 WC Computer Science, Hardware & Architecture; Telecommunications SC Computer Science; Telecommunications GA HA500 UT WOS:A1991HA50000008 ER PT J AU MIYOSHI, DS GREEN, MW AF MIYOSHI, DS GREEN, MW TI SECURITY AND TECHNOLOGY - A BETTER MOUSETRAP SO AT&T TECHNICAL JOURNAL LA English DT Article AB Sandia National Laboratories is the Department of Energy's lead laboratory in physical security research and development. It is now working to transfer this technology base to the private sectors, where we believe society will benefit greatly from improved security systems. We discuss projects that typify Sandia's efforts and exemplify the opportunities this technology provides. RP MIYOSHI, DS (reprint author), SANDIA NATL LABS,NUCL SECUR SYST,ALBUQUERQUE,NM 87185, USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU AT&T BELL LABORATORIES PI MURRAY HILL PA 600 MOUNTAIN AVE,RM 3C-417 CIRCULATION GROUP P O BOX 636, MURRAY HILL, NJ 07974-0636 SN 8756-2324 J9 AT&T TECH J JI AT&T Tech. J. PD NOV-DEC PY 1991 VL 70 IS 6 BP 87 EP 91 PG 5 WC Computer Science, Hardware & Architecture; Telecommunications SC Computer Science; Telecommunications GA HA500 UT WOS:A1991HA50000009 ER PT J AU EDMONDS, CG LOO, JA LOO, RRO UDSETH, HR BARINAGA, CJ SMITH, RD AF EDMONDS, CG LOO, JA LOO, RRO UDSETH, HR BARINAGA, CJ SMITH, RD TI APPLICATION OF ELECTROSPRAY IONIZATION MASS-SPECTROMETRY AND TANDEM MASS-SPECTROMETRY IN COMBINATION WITH CAPILLARY ELECTROPHORESIS FOR BIOCHEMICAL INVESTIGATIONS SO BIOCHEMICAL SOCIETY TRANSACTIONS LA English DT Article; Proceedings Paper CT 639TH MEETING OF THE BIOCHEMICAL SOC CY JUL 16-19, 1991 CL MANCHESTER UNIV, MANCHESTER, ENGLAND SP BIOCHEM SOC HO MANCHESTER UNIV ID ZONE ELECTROPHORESIS; INTERFACE RP EDMONDS, CG (reprint author), PACIFIC NW LAB, BATTELLE BLVD, RICHLAND, WA 99352 USA. RI Smith, Richard/J-3664-2012 OI Smith, Richard/0000-0002-2381-2349 FU NHGRI NIH HHS [HG00327] NR 10 TC 10 Z9 10 U1 0 U2 0 PU PORTLAND PRESS PI LONDON PA 59 PORTLAND PLACE, LONDON, ENGLAND W1N 3AJ SN 0300-5127 J9 BIOCHEM SOC T JI Biochem. Soc. Trans. PD NOV PY 1991 VL 19 IS 4 BP 943 EP 947 PG 5 WC Biochemistry & Molecular Biology SC Biochemistry & Molecular Biology GA GV019 UT WOS:A1991GV01900033 PM 1794588 ER PT J AU SOSNICK, T CHARLES, S STUBBS, G YAU, P BRADBURY, EM TIMMINS, P TREWHELLA, J AF SOSNICK, T CHARLES, S STUBBS, G YAU, P BRADBURY, EM TIMMINS, P TREWHELLA, J TI ORIENTING RIGID AND FLEXIBLE BIOLOGICAL ASSEMBLIES IN FERROFLUIDS FOR SMALL-ANGLE NEUTRON-SCATTERING STUDIES SO BIOPHYSICAL JOURNAL LA English DT Article ID TOBACCO-MOSAIC-VIRUS; X-RAY-DIFFRACTION; CONDENSATION MECHANISM; FIBER DIFFRACTION; CHROMATIN; SUPERSTRUCTURE; RESOLUTION; LENGTH AB Small-angle scattering from macromolecules in solution is widely used to study their structures, but the information content is limited because the molecules are generally randomly oriented and hence the data are spherically averaged, The use of oriented rodlike structures for scattering, as in fiber diffraction, greatly increases the amount of structural detail that can be obtained. A new technique using a ferromagnetic fluid has been developed to align elongated structures independent of their intrinsic magnetic properties. This technique is ideal for small-angle neutron scattering because the scattering from the ferrofluid particles can be reduced significantly by matching the neutron scattering length density of the particles to a D2O solvent ("contrast matching"). The net result is scattering primarily from the ordered biological assembly in a solution environment that can be adjusted to physiological pH and ionic strength. Scattering results from ordered tobacco mosaic virus, tobacco rattle virus, and chromatin fibers are presented. C1 UNIV CALIF LOS ALAMOS SCI LAB,DIV LIFE SCI,LOS ALAMOS,NM 87545. UNIV COLL N WALES,DEPT CHEM,BANGOR LL57 2UW,GWYNEDD,WALES. VANDERBILT UNIV,DEPT MOLEC BIOL,NASHVILLE,TN 37240. UNIV CALIF DAVIS,DEPT BIOL CHEM,DAVIS,CA 95616. INST MAX VON LAUE PAUL LANGEVIN,F-38042 GRENOBLE,FRANCE. OI Trewhella, Jill/0000-0002-8555-6766 NR 26 TC 9 Z9 9 U1 1 U2 1 PU BIOPHYSICAL SOCIETY PI BETHESDA PA 9650 ROCKVILLE PIKE, BETHESDA, MD 20814-3998 SN 0006-3495 J9 BIOPHYS J JI Biophys. J. PD NOV PY 1991 VL 60 IS 5 BP 1178 EP 1189 PG 12 WC Biophysics SC Biophysics GA GR685 UT WOS:A1991GR68500018 PM 19431809 ER PT J AU UBER, DC JAKLEVIC, JM THEIL, EH LISHANSKAYA, A MCNEELY, MR AF UBER, DC JAKLEVIC, JM THEIL, EH LISHANSKAYA, A MCNEELY, MR TI APPLICATION OF ROBOTICS AND IMAGE-PROCESSING TO AUTOMATED COLONY PICKING AND ARRAYING SO BIOTECHNIQUES LA English DT Article AB We describe a system that applies image processing and robotic techniques to automatically pick individual colonies from square petri dishes and array them in 96-well microtiter plates. Digital images of the colony distribution in the dishes are acquired using a video camera and frame buffer. Commercial image processing software is used to identify individual colonies and determine their locations. A Hewlett-Packard Microassay System robot reads the resulting coordinate file for each dish, picks cells from each identified colony and transfers the cells into a microtiter plate well. A disposable pipet tip is used as the sterile implement for colony picking. Custom holders position the dishes accurately and provide common coordinate systems for imaging and picking. The system is calibrated to account for the depth of agar in the dishes. The robot can process up to 10 dishes and 20 plates (1920 colonies) in a single run. It has successfully arrayed a cosmid library of the S. pombe genome consisting of approximately 6000 colonies in 30 petri dishes in about 40 hours of robot time. Future enhancements to the system are discussed. C1 UNIV CALIF SAN DIEGO,BIOENGN GRP,SAN DIEGO,CA 92103. RP UBER, DC (reprint author), UNIV CALIF BERKELEY,LAWRENCE BERKELEY LAB,CTR HUMAN GENOME,BERKELEY,CA 94720, USA. NR 1 TC 23 Z9 23 U1 0 U2 1 PU EATON PUBLISHING CO PI NATICK PA 154 E. CENTRAL ST, NATICK, MA 01760 SN 0736-6205 J9 BIOTECHNIQUES JI Biotechniques PD NOV PY 1991 VL 11 IS 5 BP 642 EP & PG 0 WC Biochemical Research Methods; Biochemistry & Molecular Biology SC Biochemistry & Molecular Biology GA GN890 UT WOS:A1991GN89000018 PM 1804255 ER PT J AU CONBOY, JG SHITAMOTO, R PARRA, M WINARDI, R KABRA, A SMITH, J MOHANDAS, N AF CONBOY, JG SHITAMOTO, R PARRA, M WINARDI, R KABRA, A SMITH, J MOHANDAS, N TI HEREDITARY ELLIPTOCYTOSIS DUE TO BOTH QUALITATIVE AND QUANTITATIVE DEFECTS IN MEMBRANE SKELETAL PROTEIN 4.1 SO BLOOD LA English DT Article ID HUMAN-ERYTHROCYTE-MEMBRANE; INSERTION DELETION MUTATIONS; MOLECULAR ANALYSIS; MESSENGER-RNA; BINDING-SITE; BAND 4.1; GLYCOPHORIN; REARRANGEMENTS; DEFICIENCY; DISORDERS C1 KANSAS STATE UNIV AGR & APPL SCI,DEPT PATHOL,MANHATTAN,KS 66506. RP CONBOY, JG (reprint author), UNIV CALIF BERKELEY,LAWRENCE BERKELEY LAB,1 CYCLOTRON RD,BLDG 74-157,BERKELEY,CA 94720, USA. FU NHLBI NIH HHS [HL 01877]; NIDDK NIH HHS [DK 32094, DK 26263] NR 27 TC 34 Z9 35 U1 0 U2 0 PU W B SAUNDERS CO PI PHILADELPHIA PA INDEPENDENCE SQUARE WEST CURTIS CENTER, STE 300, PHILADELPHIA, PA 19106-3399 SN 0006-4971 J9 BLOOD JI Blood PD NOV 1 PY 1991 VL 78 IS 9 BP 2438 EP 2443 PG 6 WC Hematology SC Hematology GA GM787 UT WOS:A1991GM78700039 PM 1932756 ER PT J AU ECHEVERRIA, D FINE, L LANGOLF, G SCHORK, T SAMPAIO, C AF ECHEVERRIA, D FINE, L LANGOLF, G SCHORK, T SAMPAIO, C TI ACUTE BEHAVIORAL-COMPARISONS OF TOLUENE AND ETHANOL IN HUMAN-SUBJECTS SO BRITISH JOURNAL OF INDUSTRIAL MEDICINE LA English DT Article ID ORGANIC-SOLVENTS; PSYCHOMOTOR PERFORMANCE; ENVIRONMENTAL EPIDEMIOLOGY; EVALUATION SYSTEM; EXPOSURE; ALCOHOL; METHODOLOGY; NEUROTOXICITY; SENSITIVITY; VALIDATION AB A comparison of toluene and ethanol (EtOH) induced changes in central nervous system (CNS) function and symptoms were evaluated in two studies, and when possible the effects of toluene were expressed in EtOH equivalent units. The toluene concentrations were 0, 75, and 150 ppm, bracketing the American Conference of Governmental Industrial Hygienists threshold limit value (ACGIH TLV) of 100 ppm. The socially relevant EtOH doses were 0.00, 0.33, and 0.66g EtOH/kg body weight, equivalent to two and four 3.5% 12 ounce beers. Forty two paid college students were used in each study. In the first study, subjects were exposed to toluene and an odour masking agent menthol (0.078 ppm) for seven hours over three days. In the second study EtOH or a placebo was administered at 1530 across three days also in the presence of menthol. Verbal and visual short term memory (Sternberg, digit span, Benton, pattern memory), perception (pattern recognition), psychomotor skill (simple reaction time, continuous performance, symbol-digit, hand-eye coordination, finger tapping, and critical tracking), manual dexterity (one hole), mood (profile on mood scales (POMS), fatigue (fatigue checklist), and verbal ability were evaluated at 0800, 1200, and 1600. Voluntary symptoms and observations of sleep were collected daily. A 3 x 3 latin square design evaluated solvent effects simultaneously controlling for learning and dose sequence. An analysis of variance and test for trend were performed on am-pm differences reflecting an eight hour workday and on pm scores for each solvent, in which subjects were their own control. Intersubject variation in absorbance was monitored in breath. A 5 to 10% decrement was considered meaningful if consistent with a linear trend at p < 0.05. At 150 ppm toluene, losses in performance were 6.0% for digit span, 12.1 % for pattern recognition (latency), 5% for pattern memory (number correct), 6.5% for one hole, and 3% for critical tracking. The number of headaches and eye irritation also increased in a dose-response manner. The greatest effect was found for an increasing number of observations of sleep. A range of 2 to 7% decrements suggest the ACGIH TLV of 100 ppm toluene may be a good estimate of the biological threshold supporting a re-evaluation of the TLV. At 0.66g EtOH/kg body weight symptoms and performance decrements were 6.6% for digit span, 9.2% for pattern recognition, 4.0% for continuous performance, 7.9% for symbol-digit, 16.5% for finger tapping, 6.2% for critical tracking, and 5.2% for the one hole test. The EtOH equivalents at 150 ppm toluene for digit span (0.56g EtOH/kg/body weight), the latency for pattern recognition (0.66 g EtOH kg body weight), and the one hole element "move" (0.37 g EtOH kg body weight) show that the first two measures would be affected at or above the 50 mg% blood alcohol concentration. This concentration is recognised as the lowest alcohol concentration associated with increased numbers of automobile accidents. The results suggest that EtOH may be a useful acute standard to compare the effects of various industrial solvents and support investigating an association between exposure to solvents and increased risk to safety in industry. RP ECHEVERRIA, D (reprint author), BATTELLE SEATTLE RES CTR,4000 NE 41ST ST,SEATTLE,WA 98105, USA. FU NIOSH CDC HHS [OH02071-02] NR 41 TC 53 Z9 53 U1 0 U2 4 PU BRITISH MED JOURNAL PUBL GROUP PI LONDON PA BRITISH MED ASSOC HOUSE, TAVISTOCK SQUARE, LONDON, ENGLAND WC1H 9JR SN 0007-1072 J9 BRIT J IND MED PD NOV PY 1991 VL 48 IS 11 BP 750 EP 761 PG 12 WC Public, Environmental & Occupational Health SC Public, Environmental & Occupational Health GA GM242 UT WOS:A1991GM24200005 PM 1954153 ER PT J AU KUSTAS, WP GOODRICH, DC MORAN, MS AMER, SA BACH, LB BLANFORD, JH CHEHBOUNI, A CLAASSEN, H CLEMENTS, WE DORAISWAMY, PC DUBOIS, P CLARKE, TR DAUGHTRY, CST GELLMAN, DI GRANT, TA HIPPS, LE HUETE, AR HUMES, KS JACKSON, TJ KEEFER, TO NICHOLS, WD PARRY, R PERRY, EM PINKER, RT PINTER, PJ QI, J RIGGS, AC SCHMUGGE, TJ SHUTKO, AM STANNARD, DI SWIATEK, E VANLEEUWEN, JD VANZYL, J VIDAL, A WASHBURNE, J WELTZ, MA AF KUSTAS, WP GOODRICH, DC MORAN, MS AMER, SA BACH, LB BLANFORD, JH CHEHBOUNI, A CLAASSEN, H CLEMENTS, WE DORAISWAMY, PC DUBOIS, P CLARKE, TR DAUGHTRY, CST GELLMAN, DI GRANT, TA HIPPS, LE HUETE, AR HUMES, KS JACKSON, TJ KEEFER, TO NICHOLS, WD PARRY, R PERRY, EM PINKER, RT PINTER, PJ QI, J RIGGS, AC SCHMUGGE, TJ SHUTKO, AM STANNARD, DI SWIATEK, E VANLEEUWEN, JD VANZYL, J VIDAL, A WASHBURNE, J WELTZ, MA TI AN INTERDISCIPLINARY FIELD-STUDY OF THE ENERGY AND WATER FLUXES IN THE ATMOSPHERE-BIOSPHERE SYSTEM OVER SEMIARID RANGELANDS - DESCRIPTION AND SOME PRELIMINARY-RESULTS SO BULLETIN OF THE AMERICAN METEOROLOGICAL SOCIETY LA English DT Article ID SOUTHWESTERN UNITED-STATES; SOIL-MOISTURE; METEOROLOGICAL DATA; RADIATION BUDGET; EDDY-CORRELATION; BOUNDARY-LAYER; EVAPOTRANSPIRATION; RAINFALL; EVAPORATION; BALANCE AB Arid and semiarid rangelands comprise a significant portion of the earth's land surface. Yet little is known about the effects of temporal and spatial changes in surface soil moisture on the hydrologic cycle, energy balance, and the feedbacks to the atmosphere via thermal forcing over such environments. Understanding this interrelationship is crucial for evaluating the role of the hydrologic cycle in surface-atmosphere interactions. This study focuses on the utility of remote sensing to provide measurements of surface soil moisture, surface albedo, vegetation biomass, and temperature at different spatial and temporal scales. Remote-sensing measurements may provide the only practical means of estimating some of the more important factors controlling land surface processes over large areas. Consequently, the use of remotely sensed information in biophysical and geophysical models greatly enhances their ability to compute fluxes at catchment and regional scales on a routine basis. However, model calculations for different climates and ecosystems need verification. This requires that the remotely sensed data and model computations be evaluated with ground-truth data collected at the same areal scales. The present study (MONSOON 90) attempts to address this issue for semiarid rangelands. The experimental plan included remotely sensed data in the visible, near-infrared, thermal, and microwave wavelengths from ground and aircraft platforms and, when available, from satellites. Collected concurrently were ground measurements of soil moisture and temperature, energy and water fluxes, and profile data in the atmospheric boundary layer in a hydrologically instrumented semiarid rangeland watershed. Field experiments were conducted in 1990 during the dry and wet or "monsoon season" for the southwestern United States. A detailed description of the field campaigns, including measurements and some preliminary results are given. C1 USDA ARS,US WATER CONSERVAT LAB,PHOENIX,AZ 85040. USDA ARS,ARIDLAND WATERSHED MANAGEMENT RES UNIT,TUCSON,AZ. USDA ARS,BELTSVILLE AGR RES CTR,REMOTE SENSING RES LAB,BELTSVILLE,MD 20705. CEMAGREF,ENGREF,REMOTE SENSING LAB,MONTPELLIER,FRANCE. CALTECH,JET PROP LAB,PASADENA,CA 91109. UNIV CALIF LOS ALAMOS SCI LAB,LOS ALAMOS,NM 87544. UNIV ARIZONA,DEPT OPT SCI,TUCSON,AZ 85721. US GEOL SURVEY,DIV WATER RESOURCES,DENVER,CO 80225. UTAH STATE UNIV,DEPT SOIL SCI & BIOMETEOROL,LOGAN,UT 84322. UNIV ARIZONA,SCH RENEWABLE NAT RESOURCES,TUCSON,AZ 85721. ACAD SCI USSR,INST RADIOENGN & ELECTR,MOSCOW V-71,USSR. US GEOL SURVEY,DIV WATER RESOURCES,CARSON,NV. UNIV MARYLAND,DEPT METEOROL,COLLEGE PK,MD 20742. UNIV ARIZONA,DEPT SOIL & WATER SCI,TUCSON,AZ 85721. UNIV ARIZONA,DEPT HYDROL & WATER RESOURCES,TUCSON,AZ 85721. ETUDES & RECH TELEDETECT SPATIALE,TOULOUSE,FRANCE. RP KUSTAS, WP (reprint author), USDA ARS,BELTSVILLE AGR RES CTR,HYDROL LAB,BELTSVILLE,MD 20705, USA. RI Vidal, Alain/A-3986-2009; Pinker, Rachel/F-6565-2010; Dubois-Fernandez, Pascale/A-6743-2012; Goodrich, David/B-1763-2009 OI Goodrich, David/0000-0001-7735-1448 NR 72 TC 77 Z9 80 U1 0 U2 12 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 NOV PY 1991 VL 72 IS 11 BP 1683 EP 1705 DI 10.1175/1520-0477(1991)072<1683:AIFSOT>2.0.CO;2 PG 23 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA GR433 UT WOS:A1991GR43300001 ER PT J AU MARSH, G AF MARSH, G TI THE UPS AND DOWNS OF DOWNLOADING SO BULLETIN OF THE ATOMIC SCIENTISTS LA English DT Article RP MARSH, G (reprint author), ARGONNE NATL LAB,DEF ANAL & PHYS,ARGONNE,IL 60439, USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU EDUC FOUNDATION NUCLEAR SCI PI CHICAGO PA 6042 SOUTH KIMBARK, CHICAGO, IL 60637 SN 0096-3402 J9 B ATOM SCI JI Bull. Atom. Scient. PD NOV PY 1991 VL 47 IS 9 BP 21 EP 23 PG 3 WC International Relations; Social Issues SC International Relations; Social Issues GA GM693 UT WOS:A1991GM69300012 ER PT J AU DRELL, SD AF DRELL, SD TI VERIFICATION TRIUMPHS SO BULLETIN OF THE ATOMIC SCIENTISTS LA English DT Article RP DRELL, SD (reprint author), STANFORD UNIV,STANFORD LINEAR ACCELERATOR CTR,STANFORD,CA 94305, USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU EDUC FOUNDATION NUCLEAR SCI PI CHICAGO PA 6042 SOUTH KIMBARK, CHICAGO, IL 60637 SN 0096-3402 J9 B ATOM SCI JI Bull. Atom. Scient. PD NOV PY 1991 VL 47 IS 9 BP 28 EP 29 PG 2 WC International Relations; Social Issues SC International Relations; Social Issues GA GM693 UT WOS:A1991GM69300015 ER PT J AU TELLER, E AF TELLER, E TI NUCLEAR GLASNOST SO BULLETIN OF THE ATOMIC SCIENTISTS LA English DT Article RP TELLER, E (reprint author), UNIV CALIF LAWRENCE LIVERMORE NATL LAB,LIVERMORE,CA 94550, USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU EDUC FOUNDATION NUCLEAR SCI PI CHICAGO PA 6042 SOUTH KIMBARK, CHICAGO, IL 60637 SN 0096-3402 J9 B ATOM SCI JI Bull. Atom. Scient. PD NOV PY 1991 VL 47 IS 9 BP 34 EP 35 PG 2 WC International Relations; Social Issues SC International Relations; Social Issues GA GM693 UT WOS:A1991GM69300018 ER PT J AU KOPPENAAL, RS TSCHAPLINSKI, TJ COLOMBO, SJ AF KOPPENAAL, RS TSCHAPLINSKI, TJ COLOMBO, SJ TI CARBOHYDRATE ACCUMULATION AND TURGOR MAINTENANCE IN SEEDLING SHOOTS AND ROOTS OF 2 BOREAL CONIFERS SUBJECTED TO WATER-STRESS SO CANADIAN JOURNAL OF BOTANY-REVUE CANADIENNE DE BOTANIQUE LA English DT Article DE CARBOHYDRATE ACCUMULATION; DROUGHT TOLERANCE; ORGANIC SOLUTES; OSMOTIC ADJUSTMENT; PICEA-GLAUCA; PINUS-BANKSIANA; WATER POTENTIAL COMPONENTS ID OSMOTIC ADJUSTMENT; SOLUTE ACCUMULATION; SEASONAL-CHANGES; USE EFFICIENCY; LEAVES; PLANTS; DEFICITS; GROWTH; TISSUE; LEAF AB Water potential components and organic solutes were examined in shoots and roots of potted jack pine (Pinus banksiana Lamb.) and white spruce (Picea glauca (Moench) Voss) seedlings after exposure to 7 days of water stress. The osmotic potential at the turgor loss point (psi(pi-TLP)) decreased in shoots and roots of water-stressed seedlings of both species, resulting in the maintenance of positive turgor at lower xylem water potentials (psi(X)) compared with nonstressed seedlings. Following water stress, psi(pi-TLP) of shoots and roots declined by 0.28 MPa and 0.14 MPa, respectively, in jack pine, and 0.19 MPa and 0.28 MPa, respectively, in white spruce. The osmotic potential at saturation (psi(pi-100)) was significantly lower after water stress only in jack pine roots. Active osmotic adjustment during water stress was confirmed by higher concentrations of organic solutes in white spruce shoots (1.4 x increase relative to nonstressed plants) and roots (1.7 x) and in the roots (2.2 x) but not the shoots of jack pine. Carbohydrates, particularly fructose and glucose, were the primary organic solutes accumulating in both species. Tissue elasticity was greater in the roots than the shoots of both jack pine and white spruce regardless of treatment. Consequently, the relative water content at the turgor loss point was 22% and 18% lower in the roots than in the shoots of jack pine and white spruce, respectively. Osmotic adjustment in the roots and shoots of these two boreal conifers suggests that preconditioning planting stock by exposure to water stress may increase carbohydrate concentrations and enhance seedling drought tolerance. C1 OAK RIDGE NATL LAB,OAK RIDGE,TN 37831. RP KOPPENAAL, RS (reprint author), ONTARIO MINIST NAT RESOURCES,ONTARIO FOREST RES INST,POB 969,SAULT ST MARIE P6A 5N5,ONTARIO,CANADA. NR 34 TC 24 Z9 28 U1 0 U2 8 PU NATL RESEARCH COUNCIL CANADA PI OTTAWA PA RESEARCH JOURNALS, MONTREAL RD, OTTAWA ON K1A 0R6, CANADA SN 0008-4026 J9 CAN J BOT JI Can. J. Bot.-Rev. Can. Bot. PD NOV PY 1991 VL 69 IS 11 BP 2522 EP 2528 PG 7 WC Plant Sciences SC Plant Sciences GA HA710 UT WOS:A1991HA71000021 ER PT J AU DALE, VH GARDNER, RH DEANGELIS, DL EAGAR, CC WEBB, JW AF DALE, VH GARDNER, RH DEANGELIS, DL EAGAR, CC WEBB, JW TI ELEVATION-MEDIATED EFFECTS OF BALSAM WOOLLY ADELGID ON SOUTHERN APPALACHIAN SPRUCE-FIR FORESTS SO CANADIAN JOURNAL OF FOREST RESEARCH-REVUE CANADIENNE DE RECHERCHE FORESTIERE LA English DT Article ID FRASER FIR; APHID AB The pattern of distribution of endemic Fraser fir (Abies fraseri (Pursh)Poir.) in the southern Appalachian Mountains is being affected by infestation of the exotic balsam woolly adelgid (BWA) (Adelges piceae (Ratz.)). BWA kill mature fir trees in about 3-9 years after initial infestation. Prediction of the effects of BWA in a forest region requires an assessment of (i) the population dynamics of the BWA and the fir, (ii) the prevailing physical conditions that affect the spread of BWA, and (iii) the subsequent pattern of fir mortality. This paper predicts the patterns of fir mortality and recovery on an elevation gradient by using a population model with site-specific environmental conditions and ecological interactions. The model shows that temperature range and amplitude, which affect the survival and development rates of BWA, can have an indirect influence on the spatial pattern of living trees. The model results suggest that persistence of both species, with oscillations in numbers over time and space, is probable. C1 SPRUCE FIR RES COOPERAT,RADNOR,PA 19087. RP DALE, VH (reprint author), OAK RIDGE NATL LAB,DIV ENVIRONM SCI,POB 2008,OAK RIDGE,TN 37831, USA. RI Dale, Virginia/B-6023-2009 NR 34 TC 10 Z9 11 U1 3 U2 8 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 NOV PY 1991 VL 21 IS 11 BP 1639 EP 1648 DI 10.1139/x91-227 PG 10 WC Forestry SC Forestry GA GP695 UT WOS:A1991GP69500011 ER PT J AU BADGER, CC DAVIS, J NOURIGAT, C WU, ZM HUI, TE FISHER, DR SHULMAN, H APPELBAUM, FR EARY, JF KROHN, KA MATTHEWS, DC BERNSTEIN, ID AF BADGER, CC DAVIS, J NOURIGAT, C WU, ZM HUI, TE FISHER, DR SHULMAN, H APPELBAUM, FR EARY, JF KROHN, KA MATTHEWS, DC BERNSTEIN, ID TI BIODISTRIBUTION AND DOSIMETRY FOLLOWING INFUSION OF ANTIBODIES LABELED WITH LARGE AMOUNTS OF I-131 SO CANCER RESEARCH LA English DT Article ID DOSE-RATE; IMMUNOGLOBULIN-G; THERAPY; BONE; RADIOIMMUNOTHERAPY; ANTIFERRITIN; LYMPHOMA; HEPATOMA; CANCER; CELLS AB Dosimetry and treatment planning for therapeutic infusions of radiolabeled antibodies are usually performed by extrapolation from the biodistribution of trace-labeled antibody. This extrapolation assumes that the biodistribution of high specific activity antibody will be similar to that seen with trace-labeled antibody. However, high doses of radiation result in rapid depletion of lymphoid and hematopoietic cells in lymph nodes, spleen, and marrow with replacement by blood and plasma. If radiolabeled antibody is cleared slowly from blood, this replacement may result in increased radionuclide concentrations in these tissues following infusions of antibody labeled with large amounts of radionuclide. To examine the influence of deposited radiation on the biodistribution of radiolabeled antibody, we treated mice with a constant amount of antibody that was labeled with varying amounts of I-131. Survival was determined in normal specific pathogen-free AKR/Cum mice (Thy1.2+) after infusion of anti-Thy1.1 antibody labeled with 10 to 6500-mu-g of I-131, to determine an appropriate range of I-131 doses for further study. The dose producing 50% lethality within 30 days following infusion of I-131-labeled antibody was 530-mu-Ci I-131. Biodistribution, bone marrow histology, and dosimetry were subsequently determined after infusion of 500-mu-g of antibody labeled with 10, 250, 500, or 3500-mu-Ci I-131. The amount of I-131 did not influence uptake or retention of antibody in blood, liver, lung, or kidney. In contrast, infusion of antibody labeled with 250 to 3500-mu-Ci of I-131 led to a dose-related increase in the concentration of I-131 in marrow, spleen, lymph node, and thymus. For example, at 96 h after infusion of antibody labeled with 500 or 3500-mu-Ci I-131 concentrations in marrow were 3- to 4-fold higher than after infusion of trace-labeled antibody. The increase in marrow I-131 concentrations was associated with depletion of cells and hemorrhage within the marrow space. As a result, estimated mean absorbed doses to marrow, lymph node, spleen, and thymus were 1.2 to 3.1 times higher than would have been predicted from the biodistribution of trace-labeled antibody. These results suggest that the biodistribution of trace-labeled antibody should be an accurate predictor of the behavior of high specific activity antibody in blood and solid organs such as liver and kidney. In contrast, radiation from antibody labeled with large amounts of radionuclide can result in an alteration of the concentration of radiolabeled antibody in rapidly responding tissues such as marrow. For this reason, in situations in which radiolabeled antibody remains in serum for a prolonged period (many hours to days), extrapolation from the biodistribution of trace-labeled antibody may underestimate the absorbed dose to marrow following infusion of antibody labeled with higher amounts of radionuclide. C1 UNIV WASHINGTON, DEPT MED, SEATTLE, WA 98195 USA. UNIV WASHINGTON, DEPT PATHOL, SEATTLE, WA 98195 USA. UNIV WASHINGTON, DEPT RADIOL, SEATTLE, WA 98195 USA. UNIV WASHINGTON, DEPT PEDIAT, SEATTLE, WA 98195 USA. PACIFIC NW LAB, RICHLAND, WA 99352 USA. RP BADGER, CC (reprint author), FRED HUTCHINSON CANC RES CTR, DIV CLIN RES, 1124 COLUMBIA ST, SEATTLE, WA 98104 USA. FU NCI NIH HHS [P01 CA042045, CA26386] NR 29 TC 19 Z9 19 U1 0 U2 0 PU AMER ASSOC CANCER RESEARCH PI PHILADELPHIA PA PUBLIC LEDGER BLDG, SUITE 816, 150 S. INDEPENDENCE MALL W., PHILADELPHIA, PA 19106 SN 0008-5472 J9 CANCER RES JI Cancer Res. PD NOV 1 PY 1991 VL 51 IS 21 BP 5921 EP 5928 PG 8 WC Oncology SC Oncology GA GM477 UT WOS:A1991GM47700023 PM 1682038 ER PT J AU PINNADUWAGE, LA CHRISTOPHOROU, LG AF PINNADUWAGE, LA CHRISTOPHOROU, LG TI ENHANCED ELECTRON-ATTACHMENT TO SUPEREXCITED STATES OF NITRIC-OXIDE SO CHEMICAL PHYSICS LETTERS LA English DT Article ID MULTI-PHOTON IONIZATION; DISSOCIATIVE ATTACHMENT; MULTIPHOTON IONIZATION; SPECTROSCOPY; TEMPERATURE; 2-PHOTON AB We report the observation of enhanced electron attachment to laser-excited superexcited states of nitric oxide. These states were produced in multiphoton excitation processes via (i) real and virtual states, and (ii) only virtual states. The attaching electrons were produced in situ via concomitant multiphoton ionization. Several orders-of-magnitude enhancement in the electron-attachment rate constant was observed for the superexcited states compared to the ground electronic state. 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 PHYS GRP,POB 2008,OAK RIDGE,TN 37831, USA. NR 21 TC 23 Z9 23 U1 1 U2 1 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0009-2614 J9 CHEM PHYS LETT JI Chem. Phys. Lett. PD NOV 1 PY 1991 VL 186 IS 1 BP 4 EP 10 DI 10.1016/0009-2614(91)80182-W PG 7 WC Chemistry, Physical; Physics, Atomic, Molecular & Chemical SC Chemistry; Physics GA GP942 UT WOS:A1991GP94200002 ER PT J AU CHRISTOPHOROU, LG DATSKOS, PG CARTER, JG AF CHRISTOPHOROU, LG DATSKOS, PG CARTER, JG TI EFFECT OF VIBRATIONAL-EXCITATION ON ELECTRON-TRANSPORT IN GASES SO CHEMICAL PHYSICS LETTERS LA English DT Article ID CROSS-SECTIONS; SCATTERING; METHANE AB The thermal electron mobility was found to increase with increasing temperature T for CH4 and to decrease with T for C2F6. These findings can be understood on the basis of the momentum transfer cross section sigma-m(epsilon) of the two molecules and the effect of vibrational excitation on electron transport. C1 UNIV TENNESSEE,DEPT PHYS,KNOXVILLE,TN 37996. RP CHRISTOPHOROU, LG (reprint author), OAK RIDGE NATL LAB,DIV HLTH & SAFETY RES,ATOM MOLEC & HIGH VOLTAGE PHYS GRP,OAK RIDGE,TN 37831, USA. NR 17 TC 10 Z9 10 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 NOV 1 PY 1991 VL 186 IS 1 BP 11 EP 14 DI 10.1016/0009-2614(91)80183-X PG 4 WC Chemistry, Physical; Physics, Atomic, Molecular & Chemical SC Chemistry; Physics GA GP942 UT WOS:A1991GP94200003 ER PT J AU KLOTS, CE AF KLOTS, CE TI QUASI-EQUILIBRIUM RATE CONSTANTS FOR THERMIONIC EMISSION FROM SMALL PARTICLES SO CHEMICAL PHYSICS LETTERS LA English DT Article AB A modified hard-sphere model for electron capture by small aggregates is used to derive an expression for the rate constants for thermionic emission from isolated aggregates of matter. Its connection with earlier models for autoionization is indicated. The use of generalized Arrhenius plots for comparing experiment and theory is outlined. RP KLOTS, CE (reprint author), OAK RIDGE NATL LAB,DIV HLTH & SAFETY RES,CHEM PHYS SECT,OAK RIDGE,TN 37831, USA. NR 11 TC 118 Z9 118 U1 0 U2 4 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 NOV 1 PY 1991 VL 186 IS 1 BP 73 EP 76 DI 10.1016/0009-2614(91)80194-3 PG 4 WC Chemistry, Physical; Physics, Atomic, Molecular & Chemical SC Chemistry; Physics GA GP942 UT WOS:A1991GP94200014 ER PT J AU KOURI, DJ HOFFMAN, DK AF KOURI, DJ HOFFMAN, DK TI TIME-DEPENDENT INTEGRAL-EQUATION APPROACH TO QUANTUM DYNAMICS OF SYSTEMS WITH TIME-DEPENDENT POTENTIALS SO CHEMICAL PHYSICS LETTERS LA English DT Article ID SCATTERING AB The solution of the time-dependent Schrodinger equation in the form exp(-iHt/hBAR)PSI(0) is valid only for Hamiltonian systems for which H is independent of time. This fact precludes the solution in this form for any time interval, t, during which H changes significantly. We present a formal solution, by means of integral equations, which is valid for time-dependent potentials and arbitrarily long times, as well as for time-dependent stochastic potentials. An important feature of the approach is the explicit inclusion of time ordering of noncommuting operators even when the formal solution is converted into a computationally viable form. The resulting time-ordered expression provides a basis for numerical algorithms for treating such systems to arbitrary accuracy. Several schemes for implementing the approach are presented. Some problems for which the present approach is the appropriate one include: (1) mixed quantum and classical systems (e.g., systems containing both light and heavy particles); (2) systems in which the interaction with radiation is treated semiclassically and (3) nonisolated systems. In addition we show briefly how the same techniques can be applied to treat the von Neumann equation for the density matrix, time-dependent Hohenberg-Kohn-Sham density functional equations (where the time dependence arises from a mixed quantum-classical treatment of electron-ion interactions in solids), and to an example of a nonisolated system, namely a driven oscillator. C1 UNIV HOUSTON, DEPT PHYS, HOUSTON, TX 77204 USA. IOWA STATE UNIV SCI & TECHNOL, DEPT CHEM, AMES, IA 50011 USA. IOWA STATE UNIV SCI & TECHNOL, US DOE, AMES LAB, AMES, IA 50011 USA. RP UNIV HOUSTON, DEPT CHEM, HOUSTON, TX 77204 USA. NR 31 TC 7 Z9 7 U1 0 U2 4 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0009-2614 EI 1873-4448 J9 CHEM PHYS LETT JI Chem. Phys. Lett. PD NOV 1 PY 1991 VL 186 IS 1 BP 91 EP 99 DI 10.1016/0009-2614(91)80197-6 PG 9 WC Chemistry, Physical; Physics, Atomic, Molecular & Chemical SC Chemistry; Physics GA GP942 UT WOS:A1991GP94200017 ER PT J AU KOBAYASHI, H BUN, K MIYAMOTO, A NAITO, T KATO, R KOBAYASHI, A WILLIAMS, JM AF KOBAYASHI, H BUN, K MIYAMOTO, A NAITO, T KATO, R KOBAYASHI, A WILLIAMS, JM TI SUPERCONDUCTING TRANSITION OF A GREASE-COATED CRYSTAL OF KAPPA-(BEDT-TTF)2CU[N(CN)2]CL SO CHEMISTRY LETTERS LA English DT Article ID PRESSURE ORGANIC SUPERCONDUCTOR; TC AB Superconducting transition of the grease-coated crystal of kappa-(BEDT-TTF)2 Cu[N(CN)2]Cl has been confirmed. There are at least three types of these crystals with different resistivity behaviors, of which the crystal exhibiting a resistivity anomaly around 50 K, undergoes a superconducting transition at 12.5 K, when it is coated with Apiezon L grease. C1 UNIV TOKYO, INST SOLID STATE PHYS, MINATO KU, TOKYO 106, JAPAN. UNIV TOKYO, FAC SCI, DEPT CHEM, BUNKYO KU, TOKYO 113, JAPAN. ARGONNE NATL LAB, DIV CHEM, ARGONNE, IL 60439 USA. ARGONNE NATL LAB, DIV MAT SCI, ARGONNE, IL 60439 USA. RP KOBAYASHI, H (reprint author), TOHO UNIV, FAC SCI, DEPT CHEM, FUNABASHI, CHIBA 274, JAPAN. RI Kato, Reizo/I-1073-2014 NR 9 TC 18 Z9 18 U1 0 U2 2 PU CHEMICAL SOC JAPAN PI TOKYO PA 1-5 KANDA-SURUGADAI CHIYODA-KU, TOKYO, 101-8307, JAPAN SN 0366-7022 EI 1348-0715 J9 CHEM LETT JI Chem. Lett. PD NOV PY 1991 IS 11 BP 1997 EP 2000 DI 10.1246/cl.1991.1997 PG 4 WC Chemistry, Multidisciplinary SC Chemistry GA GR281 UT WOS:A1991GR28100034 ER PT J AU JAIN, A CHI, KM KODAS, TT HAMPDENSMITH, MJ FARR, JD PAFFETT, MF AF JAIN, A CHI, KM KODAS, TT HAMPDENSMITH, MJ FARR, JD PAFFETT, MF TI CHEMICAL VAPOR-DEPOSITION OF COPPER FROM (HEXAFLUOROACETYLACETONATO)(ALKYNE)-COPPER(I) COMPLEXES VIA DISPROPORTIONATION SO CHEMISTRY OF MATERIALS LA English DT Note C1 UNIV NEW MEXICO,DEPT CHEM ENGN,ALBUQUERQUE,NM 87131. UNIV NEW MEXICO,DEPT CHEM,ALBUQUERQUE,NM 87131. UNIV CALIF LOS ALAMOS SCI LAB,CLS-1,LOS ALAMOS,NM 87545. NR 19 TC 106 Z9 106 U1 0 U2 7 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 SN 0897-4756 J9 CHEM MATER JI Chem. Mat. PD NOV-DEC PY 1991 VL 3 IS 6 BP 995 EP 997 DI 10.1021/cm00018a005 PG 3 WC Chemistry, Physical; Materials Science, Multidisciplinary SC Chemistry; Materials Science GA GR966 UT WOS:A1991GR96600005 ER PT J AU BENSON, DK TRACY, CE AF BENSON, DK TRACY, CE TI ELECTROCHROMIC, SUN-CONTROL WINDOWS SO CHEMTECH LA English DT Article RP BENSON, DK (reprint author), SOLAR ENERGY RES INST,1617 COLE BLVD,GOLDEN,CO 80401, USA. NR 8 TC 2 Z9 2 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 NOV PY 1991 VL 21 IS 11 BP 677 EP 680 PG 4 WC Chemistry, Applied SC Chemistry GA GN877 UT WOS:A1991GN87700011 ER PT J AU RICE, SF FOLTZ, MF AF RICE, SF FOLTZ, MF TI VERY HIGH-PRESSURE COMBUSTION - REACTION PROPAGATION RATES OF NITROMETHANE WITHIN A DIAMOND ANVIL CELL SO COMBUSTION AND FLAME LA English DT Article ID STIMULATED RAMAN-SCATTERING; THERMAL-DECOMPOSITION; SINGLE-PULSE; LIQUID NITROMETHANE; HIGH-TEMPERATURES; ASYMPTOTIC THEORY; CARBON-DISULFIDE; SPECTROSCOPY; COMPRESSION; NITROGEN AB The combustion-front propagation rate of nitromethane has been examined to pressures of 40 GPa. A new and general technique involving pulsed laser ignition of an energic material within a diamond anvil cell and a method for monitoring the rapid decomposition of nitromethane and other explosives to more stable chemical products is described in detail. Nitromethane is shown to exhibit a flame propagation rate that increases smoothly to 100 m/s at 30 GPa as a function of pressure. Above 30 GPa, the final solid-state combustion products change dramatically and the flame propagation rate begins to decrease. The combustion-front propagation rate is analyzed in terms of an existing condensed-phase model that predicts a relationship between the front propagation rate, U, and the pressure derivative of the chemical kinetic activation energy, dE(a)/dP, such that a plot of logU2 vs. P should be linear. The activation energy is analyzed to yield an effective volume of activation, DELTA-V-dagger, of -3.4 ml/mol. The chemical kinetic parameters determined from the combustion-front propagation rate analysis of solid high-pressure nitromethane is compared with results from other thermal decomposition studies of this prototypic molecular explosive. C1 UNIV CALIF LAWRENCE LIVERMORE NATL LAB,LIVERMORE,CA 94550. NR 34 TC 20 Z9 21 U1 1 U2 9 PU ELSEVIER SCIENCE INC PI NEW YORK PA 655 AVENUE OF THE AMERICAS, NEW YORK, NY 10010 SN 0010-2180 J9 COMBUST FLAME JI Combust. Flame PD NOV PY 1991 VL 87 IS 2 BP 109 EP 122 DI 10.1016/0010-2180(91)90161-4 PG 14 WC Thermodynamics; Energy & Fuels; Engineering, Multidisciplinary; Engineering, Chemical; Engineering, Mechanical SC Thermodynamics; Energy & Fuels; Engineering GA GT792 UT WOS:A1991GT79200001 ER PT J AU MILLER, EK BURKE, GJ AF MILLER, EK BURKE, GJ TI USING MODEL-BASED PARAMETER-ESTIMATION TO INCREASE THE PHYSICAL INTERPRETABILITY AND NUMERICAL EFFICIENCY OF COMPUTATIONAL ELECTROMAGNETICS SO COMPUTER PHYSICS COMMUNICATIONS LA English DT Article ID TRANSIENT DATA AB All of electromagnetics, whether measurement, analysis, or computation, may be regarded as activities of information acquisition, processing, and presentation. It is relevant to mention the information-intensive nature of electromagnetics, because this property can provide a useful, unifying perspective from which might be developed efficiency improvements in these various areas. If, for example, redundant information can be reduced or avoided in numerical calculations, the result should be a possibly substantial decrease in the amount of computer time that is needed for computer modeling. In this paper, we consider the use of a generalized signal-processing approach called "model-based parameter estimation" (MBPE) for making various improvements in either the efficiency of electromagnetic computer modeling or the efficiency of representing electromagnetic observables. One is to increase the efficiency of the basic model computation itself, a typical example being that of replacing the rigorous Green's function for the antenna-interface problem by a simpler, more easily computable, approximation. Another is to make more efficient use of the results that are computed, for example, by reducing the number of samples needed to construct a transfer function over some frequency band. A third arises because the electromagnetic fields/sources in various transformed-pair domains, such as exhibited by the far fields and locations of a linear-source array, are described by exponential and pole series from which physically relevant parameters can be extracted, which are useful for such purposes as data compression and physical interpretation. The discussion below deals primarily with MBPE based on exponential- and poles-series models which yield generalized waveform- and spectral-domain response functions of various transform-pair variables. We demonstrate how sampling such observables in terms of the appropriate variable or derivatives thereof leads to a data matrix from which the model parameters can be computed. Various kinds of data and models are used to illustrate the breadth of potential applications, with an emphasis on estimating frequency responses from frequency-sampled data. Some concluding remarks are addressed to use of MBPE for the Green's-function application. C1 UNIV CALIF LAWRENCE LIVERMORE NATL LAB,LIVERMORE,CA 94550. RP MILLER, EK (reprint author), UNIV CALIF LOS ALAMOS SCI LAB,POB 1663,LOS ALAMOS,NM 87545, USA. NR 15 TC 25 Z9 26 U1 2 U2 4 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 NOV PY 1991 VL 68 IS 1-3 BP 43 EP 75 DI 10.1016/0010-4655(91)90193-O PG 33 WC Computer Science, Interdisciplinary Applications; Physics, Mathematical SC Computer Science; Physics GA GT614 UT WOS:A1991GT61400004 ER PT J AU KOTTAPALLI, K SARKAR, TK ADVE, R HUA, Y MILLER, EK BURKE, GJ AF KOTTAPALLI, K SARKAR, TK ADVE, R HUA, Y MILLER, EK BURKE, GJ TI ACCURATE COMPUTATION OF WIDE-BAND RESPONSE OF ELECTROMAGNETIC SYSTEMS UTILIZING NARROW-BAND INFORMATION SO COMPUTER PHYSICS COMMUNICATIONS LA English DT Article AB The concept of analytical continuation is utilized to generate the electromagnetic response over a wide frequency band. The problem of interest is TM scattering from a conducting cylinder. A method of moment formulation is utilized to generate information about the current and its derivatives at a set of specific frequencies. This information is utilized to extrapolate the current at other frequencies. The numerical results presented are in good agreement with exact data. Two techniques, namely frequency derivative and Cauchy's technique have been introduced for extrapolating and interpolating a rational function, respectively, from a few samples of frequency responses and their derivatives. This technique can be used to speed up the numerical computations of parameters like input impedance and RCS of any linear time-invariant system. C1 SYRACUSE UNIV,DEPT ELECT & COMP ENGN,SYRACUSE,NY 13244. UNIV MELBOURNE,DEPT ELECT ENGN,PARKVILLE,VIC 3052,AUSTRALIA. UNIV CALIF LOS ALAMOS SCI LAB,LOS ALAMOS,NM 87544. UNIV CALIF LAWRENCE LIVERMORE NATL LAB,LIVERMORE,CA 94550. RP KOTTAPALLI, K (reprint author), COMPACT SOFTWARE INC,PATERSON,NJ 07504, USA. NR 8 TC 4 Z9 4 U1 0 U2 1 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0010-4655 J9 COMPUT PHYS COMMUN JI Comput. Phys. Commun. PD NOV PY 1991 VL 68 IS 1-3 BP 126 EP 144 DI 10.1016/0010-4655(91)90196-R PG 19 WC Computer Science, Interdisciplinary Applications; Physics, Mathematical SC Computer Science; Physics GA GT614 UT WOS:A1991GT61400007 ER PT J AU SMART, LB ANDERSON, SL MCINTOSH, L AF SMART, LB ANDERSON, SL MCINTOSH, L TI TARGETED GENETIC INACTIVATION OF THE PHOTOSYSTEM-I REACTION CENTER IN THE CYANOBACTERIUM SYNECHOCYSTIS SP PCC-6803 SO EMBO JOURNAL LA English DT Article DE EPR SPECTROSCOPY; HETEROTROPHIC GROWTH; PHOTOSYSTEM-I; PSAA; TARGETED MUTAGENESIS ID OXYGEN-EVOLVING SYSTEM; CHLAMYDOMONAS-REINHARDTII; PROTEIN COMPLEX; CHLOROPLAST; MUTANT; CHLOROPHYLL; DEFICIENT; SUBUNIT; MAIZE; DNA AB We describe the first complete segregation of a targeted inactivation of psaA encoding one of the P700-chlorophyll alpha-apoproteins of photosystem (PS) I. A kanamycin resistance gene was used to interrupt the psaA gene in the unicellular cyanobacterittm Synechocystis sp. PCC 6803. Selection of a fully segregated mutant, ADK9, was performed under light-activated heterotrophic growth (LAHG) conditions; complete darkness except for 5 min of light every 24 h and 5 mM glucose. Under these conditions, wild-type cells showed a 4-fold decrease in chlorophyll (chl) per cell, primarily due to a decrease of PS I reaction centers. Evidence for the absence of PS I in ADK9 includes: the lack of EPR (electron paramagnetic resonance) signal I, from P700+; undetectable P700-apoprotein; greatly reduced whole-chain photosynthesis rates; and greatly reduced chl per cell, resulting in a turquoise blue phenotype. The PS I peripheral proteins PSA-C and PSA-D were not detected in this mutant. ADK9 does assemble near wild-type levels of functional PS 11 per cell, evidenced by: EPR signal II from Y(D)+; high rates of oxygen evolution with 2,6-dichloro-p-benzoquinone (DCBQ), an electron acceptor from PS II; and accumulation of D1, a PS II core polypeptide. The success of this transformation indicates that this cyanobacterium may be utilized for site-directed mutagenesis of the PS I core. C1 MICHIGAN STATE UNIV, DEPT BOT & PLANT PATHOL, E LANSING, MI 48824 USA. MICHIGAN STATE UNIV, GENET PROGRAM, E LANSING, MI 48824 USA. MICHIGAN STATE UNIV, DEPT BIOCHEM, E LANSING, MI 48824 USA. RP SMART, LB (reprint author), MICHIGAN STATE UNIV, US DOE, PLANT RES LAB, E LANSING, MI 48824 USA. OI Smart, Lawrence/0000-0002-7812-7736 NR 50 TC 78 Z9 78 U1 0 U2 5 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 NOV PY 1991 VL 10 IS 11 BP 3289 EP 3296 PG 8 WC Biochemistry & Molecular Biology; Cell Biology SC Biochemistry & Molecular Biology; Cell Biology GA GK973 UT WOS:A1991GK97300021 PM 1717264 ER PT J AU MARLAND, G TURHOLLOW, AF AF MARLAND, G TURHOLLOW, AF TI CO2 EMISSIONS FROM THE PRODUCTION AND COMBUSTION OF FUEL ETHANOL FROM CORN SO ENERGY LA English DT Article AB Concern over the increasing concentration of CO2 in the Earth's atmosphere is causing us to re-evaluate how we use energy. In particular, we need to inquire if there are alternative energy systems which discharge less net CO2 per unit of energy service. This paper deals with the CO2 fluxes associated with the use of one biomass fuel, ethanol derived from corn. In a sustainable agricultural system, there is no net CO2 flux to the atmosphere from the corn itself but there is a net CO2 flux due to the fossil-fuel supplements currently used to produce and process corn. A comparison between ethanol from corn and gasoline from crude oil becomes very complex because of the variability of corn yield, the lack of available data on corn processing, and the complexity of treating the multiple products from corn processing. When the comparison is made on an energy content basis only, with no consideration of how the products are to be used, and at the margin of the current U.S. energy system, it appears that there is a net CO2 saving associated with ethanol from corn. This net saving in CO2 emissions may be as large as 40% or as small as 20%, depending on how one chooses to evaluate the by-product credits. This analysis also demonstrates that the frequently posed question, whether the energy inputs to ethanol exceed the energy outputs, would not be an over-riding consideration even if it were true, because most of the inputs are as coal and natural gas, whereas the output is as a high-quality liquid fuel. C1 OAK RIDGE NATL LAB,DIV ENERGY,OAK RIDGE,TN 37831. RP MARLAND, G (reprint author), OAK RIDGE NATL LAB,DIV ENVIRONM SCI,POB 2008,OAK RIDGE,TN 37831, USA. NR 28 TC 44 Z9 46 U1 0 U2 4 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD, ENGLAND OX5 1GB SN 0360-5442 J9 ENERGY JI Energy PD NOV-DEC PY 1991 VL 16 IS 11-12 BP 1307 EP 1316 DI 10.1016/0360-5442(91)90004-6 PG 10 WC Thermodynamics; Energy & Fuels SC Thermodynamics; Energy & Fuels GA GY648 UT WOS:A1991GY64800004 ER PT J AU CHANDLER, WU KOLAR, S GHEORGHE, A SITNICKI, S AF CHANDLER, WU KOLAR, S GHEORGHE, A SITNICKI, S TI CLIMATE CHANGE AND ENERGY-POLICY IN EASTERN-EUROPE - 2 SCENARIOS FOR THE FUTURE SO ENERGY LA English DT Article AB The citizens of Poland, Eastern Germany, Czechoslovakia, Hungary, and Romania inhabit perhaps the most polluted environments in the world, largely because of their countries' inefficient use of energy. Energy use is two to three times greater per unit of economic output than in Western Europe. Energy inefficiency also constrains economic growth by diverting capital to unproductive use. As much as 40% of all industrial investment in Poland was consumed in energy production. The emerging democracies of Eastern Europe have embarked on reforms to make their economies more efficient. We assess their potential for energy efficiency and apply end-use analysis in an energy end-use economic model to evaluate future energy use in the region. We assume that Eastern Europe will approach current Western living standards over the next three decades and that this will in turn increase energy consumption. We have found, nevertheless, that Eastern European nations could hold energy demand virtually constant through structural reform and technical energy-efficiency improvement. The six countries in the region could save as much as 3.5 exajoules per year, with savings yielding an economic benefit of $300 million annually. Capturing the energy-efficiency potential in Eastern Europe would require a combination of market forces and policy initiatives. Such optimistic prediction, however, should not be taken at face value. Financial and technical constraints will impede some of the potential gains in energy efficiency in Eastern Europe. Overcoming them will require national leadership and decisive international cooperation. C1 BUCHAREST POLYTECH INST, BUCHAREST, ROMANIA. MINIST ENVIRONM, WARSAW, POLAND. RP CHANDLER, WU (reprint author), PACIFIC NW LAB, ADV INT STUDIES UNIT, 901 D ST SW,SUITE 900,370 ENFANT PROMENADE SW, WASHINGTON, DC 20024 USA. NR 9 TC 3 Z9 3 U1 0 U2 1 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD, ENGLAND OX5 1GB SN 0360-5442 J9 ENERGY JI Energy PD NOV-DEC PY 1991 VL 16 IS 11-12 BP 1423 EP 1435 DI 10.1016/0360-5442(91)90012-B PG 13 WC Thermodynamics; Energy & Fuels SC Thermodynamics; Energy & Fuels GA GY648 UT WOS:A1991GY64800012 ER PT J AU STREETS, DG BLOYD, CN BOYD, GA SANTINI, DJ VESELKA, TD AF STREETS, DG BLOYD, CN BOYD, GA SANTINI, DJ VESELKA, TD TI CLIMATE CHANGE AND UNITED-STATES ENERGY-POLICY SO ENERGY LA English DT Article AB We present an analysis of the ability of the US to achieve significant reductions in CO2 emissions in the future. The emission-reduction objectives are 20% by the year 2000 and 50% by 2010, measured relative to 1985 levels. The economic sectors studied are electricity supply, industrial manufacturing, and transportation. The near-term reductions are considered to be achievable but with significant disruptions; the long-term goals are unlikely to be achieved without new breakthroughs in technology. Electricity-supply options, such as increased use of NG and more-efficient technologies, cannot alone allow us to achieve the goals, and end-use conservation will likely be the major contributor. Policy intervention in the industrial sector could achieve significant emission reductions, but concerns about international competition are important. In the transportation sector, analysis shows that fuel-economy regulation is preferable to gasoline-price increases. C1 ARGONNE NATL LAB,DIV ENERGY SYST,ARGONNE,IL 60463. RP STREETS, DG (reprint author), ARGONNE NATL LAB,DIV ENVIRONM ASSESSMENT & INFORMAT SCI,ARGONNE,IL 60463, USA. OI Streets, David/0000-0002-0223-1350 NR 27 TC 4 Z9 4 U1 0 U2 1 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD, ENGLAND OX5 1GB SN 0360-5442 J9 ENERGY JI Energy PD NOV-DEC PY 1991 VL 16 IS 11-12 BP 1437 EP 1466 DI 10.1016/0360-5442(91)90013-C PG 30 WC Thermodynamics; Energy & Fuels SC Thermodynamics; Energy & Fuels GA GY648 UT WOS:A1991GY64800013 ER PT J AU WROBLEWSKI, AE REINARTZ, K VERKADE, JG AF WROBLEWSKI, AE REINARTZ, K VERKADE, JG TI MOISTURE DETERMINATION OF ARGONNE PREMIUM COAL EXTRACTS BY P-31 NMR-SPECTROSCOPY SO ENERGY & FUELS LA English DT Article ID LABILE HYDROGEN; BROWN COALS; PHOSPHINES; PYROLYSIS AB A method for the determination of moisture in coals by derivatizing pyridine-extracted moisture with a P-31 NMR tagging agent has been developed. Candidate derivatizing reagents which formed anhydride products (R2POPR2) possessing P-31 Chemical shifts that did not overlap with derivatized phenols and carboxylic acids in the coal extract included ClPOCH2CH2O (1), ClPOCMe2CMe2O (2), ClPSCH2CH2S (3), ClPPh2 (9), and Cl(O)PPh2 (5). Because of interesting but bothersome side reactions encountered with 1-3 and 9, reagent 5 was finally selected as the reagent of choice for determining moisture contents in six Argonne Premium Coals. Advantages of reagent 5 include its clean and instantaneous reaction under very mild conditions to form Ph2(O)POP(O)Ph2 (7) which contains two P-31 nuclei for NMR integration for each molecule of water reacted. C1 IOWA STATE UNIV SCI & TECHNOL,DEPT CHEM,AMES,IA 50011. IOWA STATE UNIV SCI & TECHNOL,AMES LAB,AMES,IA 50011. NR 47 TC 9 Z9 9 U1 0 U2 1 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 SN 0887-0624 J9 ENERG FUEL JI Energy Fuels PD NOV-DEC PY 1991 VL 5 IS 6 BP 786 EP 791 DI 10.1021/ef00030a003 PG 6 WC Energy & Fuels; Engineering, Chemical SC Energy & Fuels; Engineering GA GR772 UT WOS:A1991GR77200003 ER PT J AU JANNUZZI, GD SCHIPPER, L AF JANNUZZI, GD SCHIPPER, L TI THE STRUCTURE OF ELECTRICITY DEMAND IN THE BRAZILIAN HOUSEHOLD SECTOR SO ENERGY POLICY LA English DT Article DE BRAZIL; ELECTRICITY DEMAND; HOUSEHOLD SECTOR AB The present structure of residential electricity demand is analysed by electricity consumption classes and end-uses. Nearly 70% of households consume less than 150 kWh/month and are responsible for 35% of total residential demand. Other determinants of electricity-use, such as income and place of residence, are also discussed. It is found that electricity demand is increasing faster than income as the country reaches appliances saturation in upper consumption levels. Water heating and refrigeration account for the major part of residential consumption. Residential conservation efforts have started introducing more efficient lighting equipment and refrigerators, but further work will have to be done to speed up the diffusion of efficient technology at costs that can be paid by consumers. C1 UNIV CALIF BERKELEY,LAWRENCE BERKELEY LAB,BERKELEY,CA 94720. RP JANNUZZI, GD (reprint author), STATE UNIV CAMPINAS,FEM,DEPT ENERGY,CAIXA POSTAL 6122,BR-13081 CAMPINAS,SP,BRAZIL. RI Jannuzzi, Gilberto/A-6601-2013 OI Jannuzzi, Gilberto/0000-0002-5716-6947 NR 21 TC 14 Z9 14 U1 1 U2 3 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 NOV PY 1991 VL 19 IS 9 BP 879 EP 891 DI 10.1016/0301-4215(91)90013-E PG 13 WC Energy & Fuels; Environmental Sciences; Environmental Studies SC Energy & Fuels; Environmental Sciences & Ecology GA GQ333 UT WOS:A1991GQ33300013 ER PT J AU RAUTMAN, CA TREADWAY, AH AF RAUTMAN, CA TREADWAY, AH TI GEOLOGIC UNCERTAINTY IN A REGULATORY ENVIRONMENT - AN EXAMPLE FROM THE POTENTIAL YUCCA MOUNTAIN NUCLEAR WASTE REPOSITORY SITE SO ENVIRONMENTAL GEOLOGY AND WATER SCIENCES LA English DT Article ID CONDITIONAL SIMULATION; PROGRAM AB Regulatory geologists are concerned with predicting the performance of sites proposed for waste disposal or for remediation of existing pollution problems. Geologic modeling of these sites requires large-scale expansion of knowledge obtained from very limited sampling. This expansion induces considerable uncertainty into the geologic models of rock properties that are required for modeling the predicted performance of the site. One method for assessing this uncertainty is through nonparametric geostatistical simulation. Simulation can produce a series of equiprobable models of a rock property of interest. Each model honors measured values at sampled locations, and each can be constructed to emulate both the univariate histogram and the spatial covariance structure of the measured data. Computing a performance model for a number of geologic simulations allows evaluation of the effects of geologic uncertainty. A site may be judged acceptable if the number of failures to meet a particular performance criterion produced by these computations is sufficiently low. A site that produces too many failures may be either unacceptable or simply inadequately described. The simulation approach to addressing geologic uncertainty is being applied to the potential high-level nuclear waste repository site at Yucca Mountain, Nevada, U.S.A. Preliminary geologic models of unsaturated permeability have been created that reproduce observed statistical properties reasonably well. A spread of unsaturated groundwater travel times has been computed that reflects the variability of those geologic models. Regions within the simulated models exhibiting the greatest variability among multiple runs are candidates for obtaining the greatest reduction in uncertainty through additional site characterization. RP RAUTMAN, CA (reprint author), SANDIA NATL LABS,DEPT NUCL WASTE REPOSITORY TECHNOL,ALBUQUERQUE,NM 87185, USA. NR 21 TC 6 Z9 6 U1 0 U2 1 PU SPRINGER VERLAG PI NEW YORK PA 175 FIFTH AVE, NEW YORK, NY 10010 SN 0177-5146 J9 ENVIRON GEOL WATER S PD NOV-DEC PY 1991 VL 18 IS 3 BP 171 EP 184 DI 10.1007/BF01740473 PG 14 WC Environmental Sciences; Geosciences, Multidisciplinary; Water Resources SC Environmental Sciences & Ecology; Geology; Water Resources GA GP795 UT WOS:A1991GP79500003 ER PT J AU TAFFET, MJ LAMARRE, AL OBERDORFER, JA AF TAFFET, MJ LAMARRE, AL OBERDORFER, JA TI PERFORMANCE OF A MIXED-WASTE LANDFILL AMID GEOLOGIC UNCERTAINTY - LEARNING FROM A CASE-STUDY - ALTAMONT HILLS, CALIFORNIA, USA SO ENVIRONMENTAL GEOLOGY AND WATER SCIENCES LA English DT Article AB This paper presents a case study that illustrates how geologic factors. which are not always obvious without extensive study, may hamper later landfill performance. The site is Lawrence Livermore National Laboratory (LLNL) site 300. Two unlined landfills, opened n 1958, and 1968 contain small amounts of tritium, uranium-238, lead, and beryllium in a vast proportion of inert materials (gravel, wood, and plastic) Groundwater analyses indicate that tritium at activities up to 600,000 picoCuries per liter (pCi/l) is present in two plumes beneath and adjacent to the landfills within a perched water-bearing zone. The affected water-bearing zone averages 2 m in thickness and occurs within the late Miocene Neroly Formation, which is composed of feldspathic sandstones and siltstones and interbedded claystones and conglomerates. Scanning election microscopy (SEM) analysis indicates that diagenetic clays have occluded the porosity of much of the sandstones. However, abundant fractures appear to provide permeability. Depth to the water table fluctuates greatly beneath the site but averages about 10 m. In the past, following heavy rains, groundwater levels rose into the landfill bottoms and mobilized the tritium. Rapid recharge and rise of water levels appear to have been enhanced by the funnelling of surface water by topography, direct infiltration through fractures and permeable landfill materials, and the low permeability of the geologic materials that comprise the water-bearing zone. These and other hydrogeologic conditions contributed to groundwater contact with landfill materials but were not known before landfill construction. Such information is important for siting landfills in the current regulatory environment. Contaminant transport modeling indicates that even if the perched water-bearing zone were continuous to the site 300 boundary, tritium activities would undergo radioactive decay to background levels by the time the tritiated water could reach the site boundary. C1 SAN JOSE STATE UNIV,DEPT GEOL,SAN JOSE,CA 95133. RP TAFFET, MJ (reprint author), UNIV CALIF LAWRENCE LIVERMORE NATL LAB,DIV ENVIRONM RESTORAT,BOX 808,L-528,LIVERMORE,CA 94550, USA. NR 17 TC 3 Z9 3 U1 1 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 NOV-DEC PY 1991 VL 18 IS 3 BP 185 EP 194 DI 10.1007/BF01740474 PG 10 WC Environmental Sciences; Geosciences, Multidisciplinary; Water Resources SC Environmental Sciences & Ecology; Geology; Water Resources GA GP795 UT WOS:A1991GP79500004 ER PT J AU BLANCHARD, MB DOBSON, DC VOEGELE, MD YOUNKER, JL AF BLANCHARD, MB DOBSON, DC VOEGELE, MD YOUNKER, JL TI LICENSING A GEOLOGIC REPOSITORY - TYPES OF UNCERTAINTIES SO ENVIRONMENTAL GEOLOGY AND WATER SCIENCES LA English DT Article AB This paper provides a summary of the regulatory background for the U.S. geologic repository program, describing the history of the congressional actions that established the program and the allocation of responsibilities within the program. The current status of actions by the U.S. Department of Energy (DOE) to investigate a potential repository site, located at Yucca Mountain in Nye County, Nevada, is then reviewed. The U.S. Nuclear Regulatory Commission has provided guidance to the DOE for characterizing potential repository sites, and the DOE's approach to implementing that guidance is described. One of the purposes of intensive characterization of a potential repository site is to reduce uncertainties about key aspects of the site that are relevant to protection of public health and safety. However, the link between measurable site characteristics and demonstrations of compliance with regulatory criteria promulgated by the responsible federal agencies are often complex. A discussion of types of uncertainties points out that the potential licensee (DOE) and the regulator (NRC) may have differing views of the nature and importance of uncertainties. C1 SCI APPLICAT INT CORP,LAS VEGAS,NV 89109. RP BLANCHARD, MB (reprint author), US DOE,POB 98518,LAS VEGAS,NV 89193, USA. NR 13 TC 2 Z9 2 U1 0 U2 0 PU SPRINGER VERLAG PI NEW YORK PA 175 FIFTH AVE, NEW YORK, NY 10010 SN 0177-5146 J9 ENVIRON GEOL WATER S PD NOV-DEC PY 1991 VL 18 IS 3 BP 215 EP 220 DI 10.1007/BF01740477 PG 6 WC Environmental Sciences; Geosciences, Multidisciplinary; Water Resources SC Environmental Sciences & Ecology; Geology; Water Resources GA GP795 UT WOS:A1991GP79500007 ER PT J AU SIMPSON, TB AF SIMPSON, TB TI LIMITING EMISSIONS OF THE GREENHOUSE GAS, CO2 SO ENVIRONMENTAL PROGRESS LA English DT Article AB While considerable global warming uncertainties remain, limiting the emission of the greenhouse gas, CO2, at minimum cost is a growing social concern. An approach suggested is to generate electricity by processes that facilitate capture of the CO2, and then to compress and inject it into suitable underground formations. By using formations containing uneconomical deposits of energy sources such as oil, gas, Fe++, coal, etc., underground bioconversion of the CO2 to recoverable fuel forms may prove possible. RP SIMPSON, TB (reprint author), US DOE,WASHINGTON,DC 20545, USA. NR 0 TC 1 Z9 1 U1 1 U2 3 PU AMER INST CHEMICAL ENGINEERS PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 SN 0278-4491 J9 ENVIRON PROG JI Environ. Prog. PD NOV PY 1991 VL 10 IS 4 BP 248 EP 250 DI 10.1002/ep.670100409 PG 3 WC Engineering, Environmental; Engineering, Chemical; Environmental Sciences SC Engineering; Environmental Sciences & Ecology GA GV921 UT WOS:A1991GV92100006 ER PT J AU JONES, TL BETOWSKI, LD LESNIK, B CHIANG, TC TEBERG, JE AF JONES, TL BETOWSKI, LD LESNIK, B CHIANG, TC TEBERG, JE TI INTERLABORATORY COMPARISON OF THERMOSPRAY AND PARTICLE BEAM LIQUID-CHROMATOGRAPHY MASS-SPECTROMETRY INTERFACES - EVALUATION OF A CHLORINATED PHENOXY ACID HERBICIDE LIQUID-CHROMATOGRAPHY MASS-SPECTROMETRY ANALYSIS METHOD SO ENVIRONMENTAL SCIENCE & TECHNOLOGY LA English DT Article ID FORMULATIONS; DICAMBA; SALTS AB Seven laboratories participated in an interlaboratory evaluation of a liquid chromatography/mass spectrometry (LC/MS) method for the analysis of 10 chlorinated phenoxy acid herbicides. The focus of this evaluation was to test the intercomparability of LC/MS data obtained from two types of LC/MS interfaces [i.e., thermospray (TS) and particle beam (PB)]. Eight simulated sample extracts were sent to each laboratory for LC/MS analysis. There were statistically significant differences between interfaces in the quantitative data for all analytes except 2-(2,4,5-trichlorophenoxy)propanoic acid (silvex). Particle beam exhibited a high positive bias and a low relative standard deviation at the highest sample extract concentration range, 500-mu-g/mL, while TS showed a low bias and a low relative standard deviation at the lowest sample extract concentration range, 5-mu-g/mL. Another factor of this study was to look for any performance differences between interfaces of the same type, but differing manufacturers. A statistical difference was observed, between PB interfaces, for 2-(1-methylpropyl)-4,6-dinitrophenol (dinoseb). C1 US EPA,ENVIRONM MONITORING SYST LAB,POB 93478,LAS VEGAS,NV 89193. US DOE,LAB MANAGEMENT BRANCH,GERMANTOWN,MD 20874. LOCKHEED ENGN & SCI CO,LAS VEGAS,NV 89119. NR 10 TC 37 Z9 37 U1 0 U2 5 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 NOV PY 1991 VL 25 IS 11 BP 1880 EP 1884 DI 10.1021/es00023a006 PG 5 WC Engineering, Environmental; Environmental Sciences SC Engineering; Environmental Sciences & Ecology GA GM848 UT WOS:A1991GM84800012 ER PT J AU MULVEY, M AHO, JM LYDEARD, C LEBERG, PL SMITH, MH AF MULVEY, M AHO, JM LYDEARD, C LEBERG, PL SMITH, MH TI COMPARATIVE POPULATION GENETIC-STRUCTURE OF A PARASITE (FASCIOLOIDES-MAGNA) AND ITS DEFINITIVE HOST SO EVOLUTION LA English DT Article DE FASCIOLOIDES-MAGNA; GENETIC POPULATION STRUCTURE; HOST-PARASITE RELATIONSHIPS; LIVER FLUKE; WHITE-TAILED DEER ID WHITE-TAILED DEER; ODOCOILEUS-VIRGINIANUS; NATURAL-POPULATIONS; VARIABILITY; DIFFERENTIATION; BIOLOGY; GROWTH AB The population genetic structure of the American liver fluke, Fascioloides magma, and its definitive host the white-tailed deer, Odocoileus virginianus, was examined in South Carolina. Flukes were significantly more common in deer from river-swamp habitat than upland areas and prevalence increased with host age. The distribution of flukes among deer occurred as a negative binomial with the mean dispersion parameter, k, equal to 0.17 and the range from 0.10 to 1.11 within local areas. Significant spatial genetic differentiation was observed for flukes and deer. Patterns of genetic distance in flukes were not concordant with those of the definitive host nor were they related to geographic distance between sample locations. Spatial genetic differentiation among flukes reflected the tendency for individual hosts to harbor multiple individuals from a limited number of parasite clones. The large population size of the parasite and movements of the definitive host tend to counteract factors that lead to spatial differentiation. RP MULVEY, M (reprint author), UNIV GEORGIA,SAVANNAH RIVER ECOL LAB,DRAWER E,AIKEN,SC 29802, USA. NR 47 TC 102 Z9 105 U1 2 U2 15 PU SOC STUDY EVOLUTION PI LAWRENCE PA 810 E 10TH STREET, LAWRENCE, KS 66044 SN 0014-3820 J9 EVOLUTION JI Evolution PD NOV PY 1991 VL 45 IS 7 BP 1628 EP 1640 DI 10.2307/2409784 PG 13 WC Ecology; Evolutionary Biology; Genetics & Heredity SC Environmental Sciences & Ecology; Evolutionary Biology; Genetics & Heredity GA GR184 UT WOS:A1991GR18400007 ER PT J AU MORGAN, TL YANG, DJ FRY, DG HURLIN, PJ KOHLER, SK MAHER, VM MCCORMICK, JJ AF MORGAN, TL YANG, DJ FRY, DG HURLIN, PJ KOHLER, SK MAHER, VM MCCORMICK, JJ TI CHARACTERISTICS OF AN INFINITE LIFE-SPAN DIPLOID HUMAN FIBROBLAST CELL STRAIN AND A NEAR-DIPLOID STRAIN ARISING FROM A CLONE OF CELLS EXPRESSING A TRANSFECTED V-MYC ONCOGENE SO EXPERIMENTAL CELL RESEARCH LA English DT Article ID N-RAS ONCOGENE; MALIGNANT TRANSFORMATION; MORPHOLOGICAL TRANSFORMATION; T-ANTIGEN; IMMORTALIZATION; SENESCENCE; GROWTH C1 MICHIGAN STATE UNIV, DEPT BIOCHEM, E LANSING, MI 48824 USA. MICHIGAN STATE UNIV, DEPT MICROBIOL, CARCINOGENESIS LAB, E LANSING, MI 48824 USA. RP MORGAN, TL (reprint author), PACIFIC NW LAB, RICHLAND, WA 99352 USA. RI Morgan, Thomas/J-5020-2015 OI Morgan, Thomas/0000-0003-1988-5067 FU NCI NIH HHS [CA21289]; NIEHS NIH HHS [ES65152] NR 30 TC 76 Z9 77 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 0014-4827 J9 EXP CELL RES JI Exp. Cell Res. PD NOV PY 1991 VL 197 IS 1 BP 125 EP 136 DI 10.1016/0014-4827(91)90489-H PG 12 WC Oncology; Cell Biology SC Oncology; Cell Biology GA GK787 UT WOS:A1991GK78700018 PM 1915659 ER PT J AU SWANEY, G GRIMM, U SEBEK, R AF SWANEY, G GRIMM, U SEBEK, R TI ATTRITION AND BREAKAGE OF A NEW-ALBANY SHALE AT PROCESS TEMPERATURES SO FUEL LA English DT Article; Proceedings Paper CT EASTERN OIL SHALE SYMP CY NOV 06-08, 1990 CL UNIV KENTUCKY, INST MIN & MINERALS RES, LEXINGTON, KY SP US DOE, STONE & WEBSTER ENGN, INST GAS TECHNOL, UNIV KENTUCKY, CTR APPL ENERGY RES HO UNIV KENTUCKY, INST MIN & MINERALS RES DE OIL SHALE; PARTICLE SIZE; ATTRITION AB An improved, high temperature rolling attrition tester (RAT) has been used to measure attrition and breakage of a New Albany eastern oil shale. The RAT is an inconel drum, suspended and rotating in an electric furnace. It is capable of temperatures from ambient to 1000-degrees-C and controlled attrition atmospheres at ambient pressure. While such high temperatures are not used during retorting of the shale, they do allow the study of mineral reactions which could occur when combusting spent shale for waste heat recovery. The effect of temperature has been studied over the full temperature range, with more experimentation concentrated on the typical retorting range of 300-600-degrees-C. Attrition and breakage under nitrogen, air and carbon dioxide was measured, and feed particle sizes ranged from 16 mm to fines. The resultant particle size distributions were bimodal, and attrition under air was substantially higher than that under nitrogen. For the larger feed sizes and short tumbling times, the breakage kinetics were linear, and breakage rates exhibited a power law relationship with particle size. RP SWANEY, G (reprint author), US DOE,MORGANTOWN ENERGY TECHNOL CTR,POB 880,MORGANTOWN,WV 26507, USA. NR 9 TC 1 Z9 1 U1 0 U2 1 PU BUTTERWORTH-HEINEMANN LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD, OXON, ENGLAND OX5 1GB SN 0016-2361 J9 FUEL JI Fuel PD NOV PY 1991 VL 70 IS 11 BP 1260 EP 1265 DI 10.1016/0016-2361(91)90211-R PG 6 WC Energy & Fuels; Engineering, Chemical SC Energy & Fuels; Engineering GA GN191 UT WOS:A1991GN19100004 ER PT J AU SHEN, MS LUI, AP SHADLE, LJ ZHANG, GQ MORRIS, GJ AF SHEN, MS LUI, AP SHADLE, LJ ZHANG, GQ MORRIS, GJ TI KINETIC-STUDIES OF RAPID OIL-SHALE PYROLYSIS .2. RAPID PYROLYSIS OF OIL SHALES IN A LAMINAR-FLOW ENTRAINED REACTOR SO FUEL LA English DT Article; Proceedings Paper CT EASTERN OIL SHALE SYMP CY NOV 06-08, 1990 CL UNIV KENTUCKY, INST MIN & MINERALS RES, LEXINGTON, KY SP US DOE, STONE & WEBSTER ENGN, INST GAS TECHNOL, UNIV KENTUCKY, CTR APPL ENERGY RES HO UNIV KENTUCKY, INST MIN & MINERALS RES DE OIL SHALE; PYROLYSIS; KINETIC ID TEMPERATURE; COAL AB Rapid pyrolysis of Kentucky New Albany shale was conducted in a laminar-flow entrained reactor (LFER) to obtain a fundamental understanding of thermal reactions, which occur during high-heating-rate retorting processes. The reactor configuration was designed to simplify operation and allow accurate modelling. Temperature characterization and flow visualization in the LFER were conducted to provide the data necessary to proceed with a kinetic study on the rapid pyrolysis of oil shale. The reactor with gas preheaters was constructed to achieve high particle heating rates and to feed oil shale fine particles generated from beneficiation. The rapid pyrolysis of raw and beneficiated oil shales was carried out in nitrogen at temperatures between 700-degrees-C and 850-degrees-C, with gas preheat temperatures up to 980-degrees-C. For each temperature, the sampling probe was set at different positions along the length of the reactor tube to obtain different residence times. A pyrolysis kinetic model of LFER has been developed to calculate the particle heat-up rate and residence time under each set of conditions. Comparisons are presented to evaluate the effects of beneficiation, temperature and heating rate as well as residence time. The effects of particle size and gas environment on heat transfer rates and conversion yields were also studied, and the results were used to validate the heat transfer model and to evaluate the impact of devolatilization behaviour on shale combustion in a circulating fluidized-bed reactor. C1 W VIRGINIA UNIV,DEPT MECH ENGN,MORGANTOWN,WV 26506. RP SHEN, MS (reprint author), MORGANTOWN ENERGY TECHNOL CTR,MORGANTOWN,WV 26507, USA. OI Shadle, Lawrence/0000-0002-6283-3628 NR 25 TC 10 Z9 11 U1 0 U2 1 PU BUTTERWORTH-HEINEMANN LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD, OXON, ENGLAND OX5 1GB SN 0016-2361 J9 FUEL JI Fuel PD NOV PY 1991 VL 70 IS 11 BP 1277 EP 1284 DI 10.1016/0016-2361(91)90214-U PG 8 WC Energy & Fuels; Engineering, Chemical SC Energy & Fuels; Engineering GA GN191 UT WOS:A1991GN19100007 ER PT J AU COBURN, TT MORRIS, CJ AF COBURN, TT MORRIS, CJ TI BENCH SCALE STUDIES OF OIL-SHALE FLASH PYROLYSIS UNDER HOT-RECYCLED-SOLID CONDITIONS SO FUEL LA English DT Article; Proceedings Paper CT EASTERN OIL SHALE SYMP CY NOV 06-08, 1990 CL UNIV KENTUCKY, INST MIN & MINERALS RES, LEXINGTON, KY SP US DOE, STONE & WEBSTER ENGN, INST GAS TECHNOL, UNIV KENTUCKY, CTR APPL ENERGY RES HO UNIV KENTUCKY, INST MIN & MINERALS RES DE OIL SHALE; PYROLYSIS; SOLID-RECYCLE RETORTING AB Burnt oil shale cokes oil and reduces the hydrocarbon yield from a hot-recycled-solid (HRS) retort. A novel volatile hydrocarbon detector that gives a precise organic carbon balance under HRS conditions has been designed to investigate flash pyrolysis of eastern and western oil shales. The kerogen H:C atomic ratio sets a theoretical upper limit on yield and allows experimental trends from eastern oil shale studies to be applied to western oil shale. This limit cannot be exceeded unless external hydrogen donors are introduced. The additional oil formed when eastern oil shale pyrolyses under steam fluidization conditions apparently results partially from an increase in H donors as steam reacts with iron-containing minerals. Oil vapour losses due to coking increase as burnt shale surface area increases, but Surface area and, hence, coking activity decreases as the burn temperature increases. Thus, eastern spent shale burnt at 1060 K cokes less oil than when burnt at 750 K. However, with a heat carrier:raw shale ratio of three, 50 wt% more oil plus gas was obtained with unburnt rather than burnt Devonian shale, even though porosities and surface areas of the two materials are similar. Procedures to make burnt shale more like unburnt retorted shale have realized some increase in oil yield under solid recycle conditions. Reduction with H-2 and carbon deposition are methods for successfully reducing the coking activity of burnt shale. A small quantity of coke deposited onto surfaces from the vapour phase is more effective than partially oxidized residual carbon (char) for surface deactivation. RP COBURN, TT (reprint author), UNIV CALIF LAWRENCE LIVERMORE NATL LAB,POB 808,L-365,LIVERMORE,CA 94550, USA. NR 16 TC 1 Z9 1 U1 1 U2 4 PU BUTTERWORTH-HEINEMANN LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD, OXON, ENGLAND OX5 1GB SN 0016-2361 J9 FUEL JI Fuel PD NOV PY 1991 VL 70 IS 11 BP 1362 EP 1368 DI 10.1016/0016-2361(91)90230-8 PG 7 WC Energy & Fuels; Engineering, Chemical SC Energy & Fuels; Engineering GA GN191 UT WOS:A1991GN19100023 ER PT J AU SLOMKA, BJ BUTTERMORE, WH AF SLOMKA, BJ BUTTERMORE, WH TI SONICALLY ENHANCED BENEFICIATION OF ILLINOIS NO 6 COAL SO FUEL PROCESSING TECHNOLOGY LA English DT Article ID FLOTATION; SLIMES AB Laboratory tests were performed to investigate the effects of sonic energy on the selective removal of ash-forming minerals from Illinois No. 6 coal. The net effect of exposure to sonic energy was elucidated by using wet-sieved narrowly sized coal samples free of undersize material loosely clinging to particle surfaces. A 10-kHz near-field array processor, configured for continuous rinsing of coal in the presence of sonic waves, was used. Results for sonically treated, then wet-sieved coal and the initial wet-sieved sample showed ash content removals ranging from 11.6 to 31.3% by weight, as a result of exposure to pulsed sonic energy for a 50-second total time of sonic treatment. Calculated recoveries of heating value ranged from 97.6 to as high as 99.8%, depending on the particle size of coal treated. Ash content of the sonically dislodged undersize material ranged from 55.0 to 86.9% by weight. Exposure to sonic energy also enhanced the floatability of Illinois No. 6 coal. Lower ash-content float fractions resulted from sonic pretreatment of the coal feed, compared to float fractions of wet-sieved coal not exposed to sonic energy. Separate tests with specific gravity fractions of Illinois No. 6 coal have shown that exposure to sonic energy promotes separation of coal-mineral composite particles. C1 IOWA STATE UNIV SCI & TECHNOL,IOWA STATE MINING & MINERAL RES INST,AMES,IA 50011. RP SLOMKA, BJ (reprint author), IOWA STATE UNIV SCI & TECHNOL,AMES LAB,AMES,IA 50011, USA. NR 14 TC 1 Z9 1 U1 0 U2 0 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0378-3820 J9 FUEL PROCESS TECHNOL JI Fuel Process. Technol. PD NOV PY 1991 VL 29 IS 1-2 BP 133 EP 142 DI 10.1016/0378-3820(91)90023-6 PG 10 WC Chemistry, Applied; Energy & Fuels; Engineering, Chemical SC Chemistry; Energy & Fuels; Engineering GA GR398 UT WOS:A1991GR39800011 ER PT J AU ZHU, RB WANG, XZ FENG, L DING, DZ HE, JY LIU, HJ JIANG, JC CHEN, GA YUAN, Y YANG, LC CHEN, ZL AF ZHU, RB WANG, XZ FENG, L DING, DZ HE, JY LIU, HJ JIANG, JC CHEN, GA YUAN, Y YANG, LC CHEN, ZL TI MEASUREMENT OF NEUTRON BURST PRODUCTION IN THERMAL CYCLE OF D2 ABSORBED TITANIUM CHIPS SO FUSION TECHNOLOGY LA English DT Note DE NEUTRON BURST; DEUTERIUM-ABSORBED TITANIUM; THERMAL CYCLE EXPERIMENT AB A high-level neutron coincidence counter equipped with 18 He-3 tubes and a JSR-11 shift register unit with a detection limit of 0.20 n/s for a 2-h run is used to study the neutron signals in D2 gas experiments. Different material pretreatments are selected to review the changes in frequency and size of the neutron burst production. Experimental sequence is deliberately designed to distinguish the neutron burst from fake signals, e.g., electronic noise pickup, cosmic rays, and other sources of environmental background. Ten batches of dry fusion samples are tested, among them, seven batches with neutron burst signals that occur roughly from -100-degrees-C to near room temperature. In the first four runs of a typical sample batch, seven neutron bursts are observed with neutron numbers from 15 to 482, which are 3 and 75 times, respectively, higher than the uncertainty of the background. The samples seem to be inactive after four or five temperature cycles, and the inactive samples could be reactivated by degassing and recharging of deuterium. The same anomalous phenomena were observed in the Mentou Valley Underground Laboratory situated 580 m below ground. C1 CHINA INST ATOM ENERGY,DIV NUCL PHYS,BEIJING,PEOPLES R CHINA. UNIV CALIF LOS ALAMOS SCI LAB,LOS ALAMOS,NM 87545. BEIJING ELECTRON POSITRON COLLIDER,NATL LAB,BEIJING,PEOPLES R CHINA. RP ZHU, RB (reprint author), CHINA INST ATOM ENERGY,DIV RADIOCHEM,GAMMA SPECTROSCOPY LAB,POB 275-26,BEIJING,PEOPLES R CHINA. NR 4 TC 3 Z9 3 U1 0 U2 0 PU AMER NUCLEAR SOCIETY PI LA GRANGE PK PA 555 N KENSINGTON AVENUE, LA GRANGE PK, IL 60525 SN 0748-1896 J9 FUSION TECHNOL JI Fusion Technol. PD NOV PY 1991 VL 20 IS 3 BP 349 EP 353 PG 5 WC Nuclear Science & Technology SC Nuclear Science & Technology GA GM943 UT WOS:A1991GM94300008 ER PT J AU ZWEBEN, SJ BIGLARI, H AF ZWEBEN, SJ BIGLARI, H TI SUMMARY OF THE 1ST WORKSHOP ON ALPHA-PARTICLE PHYSICS IN TFTR, PRINCETON, NEW-JERSEY, MARCH 28-29, 1991 SO FUSION TECHNOLOGY LA English DT Editorial Material RP ZWEBEN, SJ (reprint author), PRINCETON UNIV,PLASMA PHYS LAB,POB 451,PRINCETON,NJ 08544, USA. NR 2 TC 1 Z9 1 U1 0 U2 0 PU AMER NUCLEAR SOCIETY PI LA GRANGE PK PA 555 N KENSINGTON AVENUE, LA GRANGE PK, IL 60525 SN 0748-1896 J9 FUSION TECHNOL JI Fusion Technol. PD NOV PY 1991 VL 20 IS 3 BP 377 EP 380 PG 4 WC Nuclear Science & Technology SC Nuclear Science & Technology GA GM943 UT WOS:A1991GM94300015 ER PT J AU BEUGELSDIJK, TJ AF BEUGELSDIJK, TJ TI THE FUTURE OF LABORATORY AUTOMATION SO GENETIC ANALYSIS-BIOMOLECULAR ENGINEERING LA English DT Article AB Among the many factors that will define the laboratory of the future are the development of advanced computer communications systems, artificial intelligence, robotic systems, and material storage and retrieval systems. This article examines some of these factors and challenges current automation justification procedures in light of the greater competitive environment of today. RP BEUGELSDIJK, TJ (reprint author), UNIV CALIF LOS ALAMOS SCI LAB,CTR HUMAN GENOME,DIV MECH & ELECTR ENGN,LOS ALAMOS,NM 87545, USA. NR 4 TC 3 Z9 3 U1 0 U2 0 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 1050-3862 J9 GENET ANAL-BIOMOL E JI Genet. Anal.-Biomol. Eng. PD NOV PY 1991 VL 8 IS 7 BP 217 EP 220 DI 10.1016/1050-3862(91)90016-K PG 4 WC Biochemical Research Methods; Biotechnology & Applied Microbiology; Genetics & Heredity SC Biochemistry & Molecular Biology; Biotechnology & Applied Microbiology; Genetics & Heredity GA GX102 UT WOS:A1991GX10200004 PM 1772698 ER PT J AU SHARAN, SK HOLDENERKENNY, B RUPPERT, S SCHEDL, A KELSEY, G RINCHIK, EM MAGNUSON, T AF SHARAN, SK HOLDENERKENNY, B RUPPERT, S SCHEDL, A KELSEY, G RINCHIK, EM MAGNUSON, T TI THE ALBINO-DELETION COMPLEX OF THE MOUSE - MOLECULAR MAPPING OF DELETION BREAKPOINTS THAT DEFINE REGIONS NECESSARY FOR DEVELOPMENT OF THE EMBRYONIC AND EXTRAEMBRYONIC ECTODERM SO GENETICS LA English DT Article ID LOCUS REGION; GENES AB Previous complementation analyses with five (c11DSD, c5FR60Hg, c2YPSj, c4FR60Hd, c6H) of the mouse albino deletions defined at least two genes on chromosome 7, known as eed and exed, which are necessary for development of the embryonic and extraembryonic ectoderm, respectively, of early postimplantation embryos. The region of chromosome 7 containing these two genes has now been accessed at the molecular level by cloning two of the deletion breakpoint-fusion fragments. The c2YPSj breakpoints were isolated by cloning an EcoRI fragment containing a copy of an albino region-specific repeat unique to c2YPSj DNA. Similarly, the c11DSD breakpoints were isolated by cloning a c11DSD EcoRI fragment detected by a unique-sequence probe mapping proximal to the albino-coat-color locus. By mapping the cloned breakpoints relative to the remaining three deletions, the c11DSD distal breakpoint was found to define the distal limit of the region containing eed, whereas the c2YPSj and c6H distal breakpoints were found to define the proximal and distal limits, respectively, of the region containing exed. C1 GERMAN CANC RES CTR,INST CELL & TUMOR BIOL,W-6900 HEIDELBERG,GERMANY. OAK RIDGE NATL LAB,DIV BIOL,OAK RIDGE,TN 37831. RP SHARAN, SK (reprint author), CASE WESTERN RESERVE UNIV,DEPT GENET,CLEVELAND,OH 44106, USA. RI Schedl, Andreas/F-8823-2015 FU NHGRI NIH HHS [HG 00370]; NICHD NIH HHS [HD2446] NR 24 TC 37 Z9 37 U1 0 U2 0 PU GENETICS PI BALTIMORE PA 428 EAST PRESTON ST, BALTIMORE, MD 21202 SN 0016-6731 J9 GENETICS JI Genetics PD NOV PY 1991 VL 129 IS 3 BP 825 EP 832 PG 8 WC Genetics & Heredity SC Genetics & Heredity GA GL996 UT WOS:A1991GL99600023 PM 1684331 ER PT J AU GREEN, ED MOHR, RM IDOL, JR JONES, M BUCKINGHAM, JM DEAVEN, LL MOYZIS, RK OLSON, MV AF GREEN, ED MOHR, RM IDOL, JR JONES, M BUCKINGHAM, JM DEAVEN, LL MOYZIS, RK OLSON, MV TI SYSTEMATIC GENERATION OF SEQUENCE-TAGGED SITES FOR PHYSICAL MAPPING OF HUMAN-CHROMOSOMES - APPLICATION TO THE MAPPING OF HUMAN CHROMOSOME-7 USING YEAST ARTIFICIAL CHROMOSOMES SO GENOMICS LA English DT Article ID POLYMERASE CHAIN-REACTION; HUMAN GENOME; REPETITIVE DNA; LIBRARIES; CONSTRUCTION; CLONING; CLONES; GENES; TOOLS; ALU C1 WASHINGTON UNIV, SCH MED, CTR GENET MED, ST LOUIS, MO 63110 USA. WASHINGTON UNIV, SCH MED, HOWARD HUGHES MED INST, ST LOUIS, MO 63110 USA. UNIV CALIF LOS ALAMOS SCI LAB, CTR HUMAN GENOME STUDIES, LOS ALAMOS, NM 87545 USA. RP WASHINGTON UNIV, SCH MED, DEPT GENET, ST LOUIS, MO 63110 USA. FU NHGRI NIH HHS [P50-HG00201] NR 33 TC 79 Z9 79 U1 0 U2 1 PU ACADEMIC PRESS INC ELSEVIER SCIENCE PI SAN DIEGO PA 525 B ST, STE 1900, SAN DIEGO, CA 92101-4495 USA SN 0888-7543 EI 1089-8646 J9 GENOMICS JI Genomics PD NOV PY 1991 VL 11 IS 3 BP 548 EP 564 DI 10.1016/0888-7543(91)90062-J PG 17 WC Biotechnology & Applied Microbiology; Genetics & Heredity SC Biotechnology & Applied Microbiology; Genetics & Heredity GA GK046 UT WOS:A1991GK04600007 PM 1837788 ER PT J AU NISHIIZUMI, K ARNOLD, JR KLEIN, J FINK, D MIDDLETON, R KUBIK, PW SHARMA, P ELMORE, D REEDY, RC AF NISHIIZUMI, K ARNOLD, JR KLEIN, J FINK, D MIDDLETON, R KUBIK, PW SHARMA, P ELMORE, D REEDY, RC TI EXPOSURE HISTORIES OF LUNAR METEORITES - ALHA81005, MAC88104, MAC88105, AND Y791197 SO GEOCHIMICA ET COSMOCHIMICA ACTA LA English DT Article; Proceedings Paper CT SPECIAL SESSION OF THE 21ST LUNAR AND PLANETARY SCIENCE CONF : THE MACALPINE HILLS LUNAR METEORITE CONSORTIUM CY MAR 12, 1990 CL HOUSTON, TX ID ACCELERATOR MASS-SPECTROMETRY; STONY METEORITES; DEPTH PROFILE; MOON; ALHA-81005; NUCLIDES; CL-36; BE-10; AL-26 AB The cosmogenic radionuclides Ca-41, Cl-36, Al-26, and Be-10 in the Allan Hills 81005, MacAlpine Hills 88104, MacAlpine Hills 88105, and Yamato 791197 meteorites were measured by accelerator mass spectrometry (AMS). Mn-53 in Allan Hills 81005 and Yamato 791197 was measured by neutron activation. These four lunar meteorites experienced similar histories. They were ejected from near the surface of the Moon ranging in depth down to 400 g/cm2 and had very short transition times (less than 0.1 Ma) from the Moon to the Earth. A comparison of the cosmogenic nuclide concentrations in MacAlpine Hills 88104 and MacAlpine Hills 88105 clearly indicates that they are a pair from the same fall. C1 UNIV CALIF LOS ALAMOS SCI LAB,LOS ALAMOS,NM 87545. UNIV PENN,DEPT PHYS,PHILADELPHIA,PA 19104. UNIV ROCHESTER,NUCL STRUCT RES LAB,ROCHESTER,NY 14627. RP NISHIIZUMI, K (reprint author), UNIV CALIF SAN DIEGO,DEPT CHEM,0317,LA JOLLA,CA 92093, USA. RI fink, David/A-9518-2012; OI Reedy, Robert/0000-0002-2189-1303 NR 41 TC 22 Z9 22 U1 0 U2 1 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 NOV PY 1991 VL 55 IS 11 BP 3149 EP 3155 DI 10.1016/0016-7037(91)90479-O PG 7 WC Geochemistry & Geophysics SC Geochemistry & Geophysics GA GT024 UT WOS:A1991GT02400012 ER PT J AU THOMAS, VA WINSKE, D AF THOMAS, VA WINSKE, D TI KINETIC SIMULATION OF THE KELVIN-HELMHOLTZ INSTABILITY AT THE VENUS IONOPAUSE SO GEOPHYSICAL RESEARCH LETTERS LA English DT Article AB Two dimensional hybrid simulations with particle ions and fluid electrons are used to calculate the kinetic evolution of the Kelvin-Helmholtz instability at a boundary similar to the ionopause at the planet Venus. The magnetic field has been chosen to be essentially transverse to the plasma flow velocity, which is the most unstable case for the Kelvin-Helmholtz instability. Effects analogous to those found in MHD simulations are recovered, including a mode cascade to longer wavelengths. In addition, isolated structures on the order of the ion gyroradius are formed which can cross the boundary in either direction. These structures may be related to flux ropes commonly observed near the ionopause of Venus. The time evolution of these structures may represent transport across the boundary layers and the smearing of the shear layer may give rise to internal structure in the boundary. Similar processes occur in magnetized layers akin to the Earth's magnetopause. RP THOMAS, VA (reprint author), UNIV CALIF LOS ALAMOS SCI LAB,LOS ALAMOS,NM 87545, USA. NR 12 TC 47 Z9 47 U1 1 U2 4 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 SN 0094-8276 J9 GEOPHYS RES LETT JI Geophys. Res. Lett. PD NOV PY 1991 VL 18 IS 11 BP 1943 EP 1946 DI 10.1029/91GL02552 PG 4 WC Geosciences, Multidisciplinary SC Geology GA GP755 UT WOS:A1991GP75500004 ER PT J AU FELDMAN, WC REEDY, RC MCKAY, DS AF FELDMAN, WC REEDY, RC MCKAY, DS TI LUNAR NEUTRON LEAKAGE FLUXES AS A FUNCTION OF COMPOSITION AND HYDROGEN CONTENT SO GEOPHYSICAL RESEARCH LETTERS LA English DT Article ID SPECTRA; ICE AB Areas of the Moon that might have enhanced concentrations of hydrogen are discussed. The fluxes of thermal, epithermal, and fast neutrons escaping from the lunar surface were calculated for eight different compositions and several hydrogen contents. These flux ratios depend on composition and are very sensitive to the hydrogen content. Their measurement using flight-proven techniques from lunar orbit should allow detection and identification of hydrogen residing in either permanently shaded cold traps near the lunar poles or mature regoliths. Knowledge of composition, especially of Fe and Ti, improves the thresholds for hydrogen detection and also could allow identification of Gd and Sm. C1 NASA,LYNDON B JOHNSON SPACE CTR,HOUSTON,TX 77058. RP FELDMAN, WC (reprint author), UNIV CALIF LOS ALAMOS SCI LAB,MS-D438,LOS ALAMOS,NM 87545, USA. OI Reedy, Robert/0000-0002-2189-1303 NR 21 TC 29 Z9 29 U1 1 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 NOV PY 1991 VL 18 IS 11 BP 2157 EP 2160 DI 10.1029/91GL02618 PG 4 WC Geosciences, Multidisciplinary SC Geology GA GP755 UT WOS:A1991GP75500058 ER PT J AU EDWARDS, BC PRIEDHORSKY, WC SMITH, BW AF EDWARDS, BC PRIEDHORSKY, WC SMITH, BW TI EXPECTED EXTREME ULTRAVIOLET-SPECTRUM OF THE LUNAR-SURFACE SO GEOPHYSICAL RESEARCH LETTERS LA English DT Article AB The moon was recently observed to be a source of very soft x-ray emission. The emission was most intense at wavelengths longer than 62 angstrom and was attributed to Thomson scattering of solar x-rays. This observation prompted us to study the emissions expected from the lunar surface in the wavelength range between 90 and 500 angstrom. Photons in this wavelength range scatter inefficiently. Instead, the solar x-rays are absorbed in the first several microns of lunar regolith. The absorbed x-rays can excite the surface elements and result in fluorescent emission. We find that much of the L- and M-shell extreme ultraviolet fluorescence, in the wavelength range between 90 and 500 angstrom, have higher peak intensities than the scattered solar spectrum. The total integrated fluorescent emission is also higher than the total scattered solar radiation. The L-shell fluorescent radiation can be an indicator of the surface abundances of Si, Al, Mg and other major lunar elements. RP EDWARDS, BC (reprint author), UNIV CALIF LOS ALAMOS SCI LAB,MAIL STOP D436,LOS ALAMOS,NM 87544, USA. OI Priedhorsky, William/0000-0003-0295-9138 NR 10 TC 7 Z9 7 U1 0 U2 0 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 SN 0094-8276 J9 GEOPHYS RES LETT JI Geophys. Res. Lett. PD NOV PY 1991 VL 18 IS 11 BP 2161 EP 2164 DI 10.1029/91GL02542 PG 4 WC Geosciences, Multidisciplinary SC Geology GA GP755 UT WOS:A1991GP75500059 ER PT J AU ELPHIC, RC FUNSTEN, HO BARRACLOUGH, BL MCCOMAS, DJ PAFFETT, MT VANIMAN, DT HEIKEN, G AF ELPHIC, RC FUNSTEN, HO BARRACLOUGH, BL MCCOMAS, DJ PAFFETT, MT VANIMAN, DT HEIKEN, G TI LUNAR-SURFACE COMPOSITION AND SOLAR WIND-INDUCED SECONDARY ION MASS-SPECTROMETRY SO GEOPHYSICAL RESEARCH LETTERS LA English DT Article ID BODIES AB The Moon has no strong global magnetic field and only a tenuous atmosphere, so solar wind ions (approximately 95% H+, 5% He++) directly bombard the lunar surface, sputtering atoms and secondary ions from the exposed grains of the regolith. The secondary ions potentially provide surface composition information through secondary ion mass spectrometry (SIMS), a standard laboratory surface composition analysis technique. In this paper we report the results of laboratory SIMS experiments on lunar soil simulants using solar wind-like ions. We find that H+ and He++, while not efficient sputterers, nevertheless produce significant fluxes of secondary lunar ions, including Na+, Mg+, Al+, Si+, K+, Ca+, Ti+, Mn+ and Fe+. We predict that lunar surface secondary-ion fluxes range between approximately 10 and 10(4) ions cm-2 s-1, depending on the species. RP ELPHIC, RC (reprint author), UNIV CALIF LOS ALAMOS SCI LAB,MS D438,LOS ALAMOS,NM 87545, USA. RI Funsten, Herbert/A-5702-2015 OI Funsten, Herbert/0000-0002-6817-1039 NR 8 TC 46 Z9 46 U1 0 U2 8 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 NOV PY 1991 VL 18 IS 11 BP 2165 EP 2168 DI 10.1029/91GL02669 PG 4 WC Geosciences, Multidisciplinary SC Geology GA GP755 UT WOS:A1991GP75500060 ER PT J AU TSANG, CF AF TSANG, CF TI THE MODELING PROCESS AND MODEL VALIDATION SO GROUND WATER LA English DT Article AB The safety assessment of underground disposal of nuclear or toxic wastes requires the use of models. Such models need to be validated to ensure, as much as possible, that they are a good representation of the actual processes occurring in the real system. In this paper an attempt is made to take a broad view by reviewing step by step the modeling process and bringing out the need for validating every step of this process. Thus, model validation includes not only comparison of modeling results with data from selected experiments , but also evaluation of procedures for the construction of conceptual models and calculational models as well as methodologies for studying data and parameter correlation. The need for advancing basic scientific knowledge in related fields, for multiple assessment groups, and for presenting our modeling efforts in open literature for public scrutiny is also emphasized. RP TSANG, CF (reprint author), UNIV CALIF BERKELEY,LAWRENCE BERKELEY LAB,DIV EARTH SCI,BERKELEY,CA 94720, USA. NR 33 TC 30 Z9 31 U1 0 U2 4 PU GROUND WATER PUBLISHING CO PI COLUMBUS PA 2600 GROUND WATER WAY, COLUMBUS, OH 43219 SN 0017-467X J9 GROUND WATER JI Ground Water PD NOV-DEC PY 1991 VL 29 IS 6 BP 825 EP 831 DI 10.1111/j.1745-6584.1991.tb00568.x PG 7 WC Geosciences, Multidisciplinary; Water Resources SC Geology; Water Resources GA GN146 UT WOS:A1991GN14600002 ER PT J AU PALMER, HE RIEKSTS, GA LYNCH, TP AF PALMER, HE RIEKSTS, GA LYNCH, TP TI PERFORMANCE OF AN ARRAY OF LARGE-VOLUME GERMANIUM DETECTORS FOR WHOLE-BODY COUNTING SO HEALTH PHYSICS LA English DT Article AB An array of four large-volume coaxial germanium detectors was installed in a shielded room for the in-vivo measurement of gamma-emitters in the body. All four detectors are in a single 50-L dewar of liquid nitrogen and are positioned underneath the supine subject with the axes of the detector elements parallel with the length of the body. This orientation gives approximately 15% more counting efficiency than having the axes of the detectors perpendicular to the body length. The detectors have resolutions that are less than 2 keV with an average of 1.86 keV for the Co-60 1.33-MeV gamma-ray peak. The efficiencies of the four detectors range from 59% to 77% of a 7.62- x 7.62-cm (3- X 3-in.) NaI(Tl) detector. The detectors are interfaced to a multichannel analyzer such that spectra from the detectors are stored both as a sum of all counts from the four detectors and as a spectrum from each detector. The sensitivity of the germanium array for measuring radioactivity in the body exceeds that of multiple large NaI(Tl) detectors for measuring single radionuclides in the body and is much superior for measuring internal depositions of radionuclide mixtures. Another major advantage of this system compared to NaI(Tl) systems is that the results can be calculated by computer analysis with minimal human interpretation. The sensitivity of the array configuration is described and applications of the array in other configurations, such as that used for measuring the very small quantities of Na-24 induced in the body during air travel, are also discussed. RP PALMER, HE (reprint author), PACIFIC NW LAB, POB 999, RICHLAND, WA 99352 USA. NR 3 TC 5 Z9 5 U1 0 U2 1 PU LIPPINCOTT WILLIAMS & WILKINS PI PHILADELPHIA PA 530 WALNUT ST, PHILADELPHIA, PA 19106-3621 USA SN 0017-9078 EI 1538-5159 J9 HEALTH PHYS JI Health Phys. PD NOV PY 1991 VL 61 IS 5 BP 595 EP 600 DI 10.1097/00004032-199111000-00001 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 GL720 UT WOS:A1991GL72000001 PM 1661276 ER PT J AU CRAWFORD, OH TURNER, JE HAMM, RN ASHLEY, JC AF CRAWFORD, OH TURNER, JE HAMM, RN ASHLEY, JC TI EFFECTS OF THE TISSUE-AIR INTERFACE IN CALCULATIONS OF BETA-PARTICLE SKIN DOSE AT A DEPTH OF 70-MU-M SO HEALTH PHYSICS LA English DT Note ID TRANSPORT; DOSIMETRY AB The effects that the tissue-air interface has on the basal-layer dose at a depth of 70-mu-m from beta-emitters on the skin surface are studied using Monte Carlo calculations. The dose is decreased at small lateral distances from a point source but is increased at large distances. RP CRAWFORD, OH (reprint author), OAK RIDGE NATL LAB, DIV HLTH & SAFETY RES, OAK RIDGE, TN 37831 USA. NR 18 TC 2 Z9 2 U1 0 U2 0 PU LIPPINCOTT WILLIAMS & WILKINS PI PHILADELPHIA PA 530 WALNUT ST, PHILADELPHIA, PA 19106-3621 USA SN 0017-9078 EI 1538-5159 J9 HEALTH PHYS JI Health Phys. PD NOV PY 1991 VL 61 IS 5 BP 641 EP 645 DI 10.1097/00004032-199111000-00008 PG 5 WC Environmental Sciences; Public, Environmental & Occupational Health; Nuclear Science & Technology; Radiology, Nuclear Medicine & Medical Imaging SC Environmental Sciences & Ecology; Public, Environmental & Occupational Health; Nuclear Science & Technology; Radiology, Nuclear Medicine & Medical Imaging GA GL720 UT WOS:A1991GL72000008 PM 1752748 ER PT J AU DOSKEY, PV AF DOSKEY, PV TI THE EFFECT OF TREATING AIR SAMPLES WITH MAGNESIUM PERCHLORATE FOR WATER REMOVAL DURING ANALYSIS FOR NONMETHANE HYDROCARBONS SO HRC-JOURNAL OF HIGH RESOLUTION CHROMATOGRAPHY LA English DT Article DE GAS CHROMATOGRAPHY, GC; FUSED SILICA CAPILLARY COLUMN; NONMETHANE HYDROCARBONS, NMHCS; MAGNESIUM PERCHLORATE; AIR ANALYSIS; CRYOGENIC PRECONCENTRATION ID GAS-CHROMATOGRAPHY; AMBIENT AIR AB A comparison has been made between two cryogenic preconcentration-high resolution gas chromatography techniques for the analysis of non-methane hydrocarbons in ambient air, one involving treatment of air samples with magnesium perchlorate to remove water, the other involving analysis without treatment. Recoveries of C1-, C2-, and C3-substituted benzenes in treated samples were 80%, 50%, and 50%, respectively. Incomplete recovery of C-7-C-9 n-1-olefins was also observed. C2-C-8 hydrocarbons and C2-C6 n-1-olefins were recovered with greater than 90% efficiency. Analyses of certified audit samples containing a mixture of C2-C-8 aliphatic and aromatic hydrocarbons at the 20 ppbv level in humidified zero-grade air indicated that the accuracy of the technique for untreated air samples was approximately 90%. The use of magnesium perchlorate for water removal cannot be recommended for the analysis of non-methane hydrocarbons in ambient air. RP DOSKEY, PV (reprint author), ARGONNE NATL LAB,DIV ENVIRONM RES,ARGONNE,IL 60439, USA. NR 8 TC 25 Z9 25 U1 0 U2 2 PU DR ALFRED HUTHIG VERLAG GMBH PI HEIDELBERG 1 PA POSTFACH 102869, W-69018 HEIDELBERG 1, GERMANY SN 0935-6304 J9 HRC-J HIGH RES CHROM JI HRC-J. High Resolut. Chromatogr. PD NOV PY 1991 VL 14 IS 11 BP 724 EP 728 PG 5 WC Chemistry, Analytical SC Chemistry GA HH359 UT WOS:A1991HH35900003 ER PT J AU STEPHENS, JR GUSTAFSON, BAS AF STEPHENS, JR GUSTAFSON, BAS TI LABORATORY REFLECTANCE MEASUREMENTS OF ANALOGS TO DIRTY ICE SURFACES ON ATMOSPHERELESS SOLAR-SYSTEM BODIES SO ICARUS LA English DT Article ID SPECTRAL REFLECTANCE; COMETARY NUCLEI; PHASE CURVES; DUST; ASTEROIDS; SPECTROSCOPY; PARTICLES; MIXTURES; METEOROIDS; RESIDUES C1 UNIV FLORIDA,DEPT ASTRON,GAINESVILLE,FL 32611. RP STEPHENS, JR (reprint author), UNIV CALIF LOS ALAMOS SCI LAB,LOS ALAMOS,NM 87545, USA. RI Gustafson, Bo/B-9526-2011 NR 43 TC 7 Z9 7 U1 1 U2 1 PU ACADEMIC PRESS INC JNL-COMP SUBSCRIPTIONS PI SAN DIEGO PA 525 B ST, STE 1900, SAN DIEGO, CA 92101-4495 SN 0019-1035 J9 ICARUS JI Icarus PD NOV PY 1991 VL 94 IS 1 BP 209 EP 217 DI 10.1016/0019-1035(91)90151-I PG 9 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA GR704 UT WOS:A1991GR70400015 ER PT J AU ZHOU, P CHENG, JL SCHAUS, CF SUN, SZ HAINS, C ZHENG, K ARMOUR, E HSIN, W MYERS, DR VAWTER, GA AF ZHOU, P CHENG, JL SCHAUS, CF SUN, SZ HAINS, C ZHENG, K ARMOUR, E HSIN, W MYERS, DR VAWTER, GA TI CASCADABLE, LATCHING PHOTONIC SWITCH WITH HIGH OPTICAL GAIN BY THE MONOLITHIC INTEGRATION OF A VERTICAL-CAVITY SURFACE-EMITTING LASER AND A PN-PN PHOTOTHYRISTOR SO IEEE PHOTONICS TECHNOLOGY LETTERS LA English DT Article ID PHOTOTRANSISTORS; DEVICE AB We report the first demonstration of a cascadable photonic switch based on the monolithic integration of a multi-quantum-well vertical-cavity surface-emitting laser (VCSEL) and a latching pn-pn photothyristor grown by LP-MOCVD. The VCSEL and pn-pn photothyristor structures can be independently optimized for optical switching, logic and memory functions. Optical switching with high gain (30 000), high contrast (30 dB), low switching power (11 nW), and latching memory have been demonstrated. C1 SANDIA NATL LABS,ALBUQUERQUE,NM 87185. RP ZHOU, P (reprint author), UNIV NEW MEXICO,CTR HIGH TECHNOL MAT,ALBUQUERQUE,NM 87131, USA. NR 11 TC 21 Z9 21 U1 0 U2 3 PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017-2394 SN 1041-1135 J9 IEEE PHOTONIC TECH L JI IEEE Photonics Technol. Lett. PD NOV PY 1991 VL 3 IS 11 BP 1009 EP 1012 DI 10.1109/68.97844 PG 4 WC Engineering, Electrical & Electronic; Optics; Physics, Applied SC Engineering; Optics; Physics GA GL590 UT WOS:A1991GL59000022 ER PT J AU RILEY, DJ TURNER, CD AF RILEY, DJ TURNER, CD TI THE INCLUSION OF WALL LOSS IN FINITE-DIFFERENCE TIME-DOMAIN THIN-SLOT ALGORITHMS SO IEEE TRANSACTIONS ON ELECTROMAGNETIC COMPATIBILITY LA English DT Article ID APERTURES; DEPTH AB Subgridding techniques enable finite-difference time-domain (FDTD) electromagnetic codes to model apertures that are much narrower than the spatial resolution of the FDTD mesh. Previous thin-slot methods have assumed that the slot walls are perfectly conducting. As the slot depth-to-width ratio becomes large, interior wall losses for realistic materials can significantly affect the coupling through the slot, and therefore these loss effects should not be neglected. This paper presents two methods for incorporating slot wall loss into the FDTD calculations. The walls are assumed to be good conductors. Loss is only applied to the current component that flows axially along the slot walls, which is generally the dominant component for slots that are long and narrow. The first method modifies an FDTD equation internal to the slot to include a surface-impedance contribution. This method is appropriate for the usual FDTD thin-slot formalisms. The second method includes the losses into a "half-space" integral equation that can be used by the recently introduced hybrid thin-slot algorithm. Results based on the two methods are compared for a variety of slot parameters and wall conductivities. RP RILEY, DJ (reprint author), SANDIA NATL LABS,DIV RADIAT & ELECTROMAGNET ANAL,ALBUQUERQUE,NM 87185, USA. NR 10 TC 5 Z9 6 U1 1 U2 2 PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017-2394 SN 0018-9375 J9 IEEE T ELECTROMAGN C JI IEEE Trans. Electromagn. Compat. PD NOV PY 1991 VL 33 IS 4 BP 304 EP 311 DI 10.1109/15.99111 PG 8 WC Engineering, Electrical & Electronic; Telecommunications SC Engineering; Telecommunications GA GK638 UT WOS:A1991GK63800004 ER PT J AU KOSTAS, JG BOVERIE, B AF KOSTAS, JG BOVERIE, B TI STATISTICAL-MODEL FOR A MODE-STIRRED CHAMBER SO IEEE TRANSACTIONS ON ELECTROMAGNETIC COMPATIBILITY LA English DT Note AB The probability density functions for one- and three-dimensional fields in a mode-stirred chamber are derived and verified with chi-square goodness-of-fit tests on experimental data. Maximum-likelihood estimators of the functions' parameters are derived, and their accuracy is determined as a function of the amount of data. These results are applied to estimating chamber Q. The amount of data required for a given accuracy is determined. RP KOSTAS, JG (reprint author), SANDIA NATL LABS,ALBUQUERQUE,NM 87185, USA. NR 10 TC 195 Z9 207 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 0018-9375 J9 IEEE T ELECTROMAGN C JI IEEE Trans. Electromagn. Compat. PD NOV PY 1991 VL 33 IS 4 BP 366 EP 370 DI 10.1109/15.99120 PG 5 WC Engineering, Electrical & Electronic; Telecommunications SC Engineering; Telecommunications GA GK638 UT WOS:A1991GK63800013 ER PT J AU MARCHON, B VO, PN KHAN, MR AGER, JW AF MARCHON, B VO, PN KHAN, MR AGER, JW TI STRUCTURE AND MECHANICAL-PROPERTIES OF HYDROGENATED CARBON-FILMS PREPARED BY MAGNETRON SPUTTERING SO IEEE TRANSACTIONS ON MAGNETICS LA English DT Article; Proceedings Paper CT 5TH JOINT MMM-INTERMAG CONF CY JUN 18-21, 1991 CL PITTSBURGH, PA SP AKASHIC MEMORIES, ALLEGHENY LUDLUM, ALLIED SIGNAL, APPL MAGNET, ARMCO, ANORD ENGN, BASF AG, CERAM MAGNET, CRUCIBLE MAT, DASTEK ID THIN-FILMS; OVERCOATS; LAYERS; MEDIA; WEAR AB Hydrogenated thin carbon films have been prepared by DC-magnetron sputtering in an hydrogen-containing Argon atmosphere. A monotonic decrease in friction buildup as well as an increase in abrasion resistance is observed for increasing hydrogen proportion in Argon, from 0 to 5%. At the same time, Raman data shows higher sp3 character and an increase in hydrogen content in the film, as monitored with FTIR, is observed. Resistivity measurements also show, a transition from conductor to insulator. For very high hydrogen content, the film becomes increasingly softer. These data are attributed to an initial increase in the sp3/sp2 bonding ratio, followed by a loss of three-dimensional cross-linking eventually leading to polymerization. C1 UNIV CALIF BERKELEY,LAWRENCE BERKELEY LAB,CTR ADV MAT,BERKELEY,CA 94720. RP MARCHON, B (reprint author), SEAGATE MAGNET,FREMONT,CA 94538, USA. RI Marchon, Bruno/H-5665-2013; OI Ager, Joel/0000-0001-9334-9751 NR 19 TC 49 Z9 50 U1 0 U2 6 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 NOV PY 1991 VL 27 IS 6 BP 5160 EP 5162 DI 10.1109/20.278773 PN 2 PG 3 WC Engineering, Electrical & Electronic; Physics, Applied SC Engineering; Physics GA HB661 UT WOS:A1991HB66100169 ER PT J AU JILES, DC THOELKE, JB AF JILES, DC THOELKE, JB TI MODELING OF THE COMBINED EFFECTS OF STRESS AND ANISOTROPY ON THE MAGNETOSTRICTION OF TB0.3DY0.7FE2 SO IEEE TRANSACTIONS ON MAGNETICS LA English DT Article; Proceedings Paper CT 5TH JOINT MMM-INTERMAG CONF CY JUN 18-21, 1991 CL PITTSBURGH, PA SP AKASHIC MEMORIES, ALLEGHENY LUDLUM, ALLIED SIGNAL, APPL MAGNET, ARMCO, ANORD ENGN, BASF AG, CERAM MAGNET, CRUCIBLE MAT, DASTEK ID TB.27DY.73FE2; MAGNETIZATION; CRYSTALS AB In this paper it is shown how the magnetization and magnetostriction of Tb0.3Dy0.7Fe2 can be calculated using a three dimensional anisotropy model, with fractional occupancies P1,...P8 along each of the easy <111> axes. This model assumes no interaction between the domains. Previous calculations were made only in the unstressed state. The present work extends this model to include the effects of applied stress. RP JILES, DC (reprint author), IOWA STATE UNIV SCI & TECHNOL,AMES LAB,AMES,IA 50011, USA. RI Jiles, David/H-9548-2012 NR 7 TC 29 Z9 29 U1 0 U2 3 PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017-2394 SN 0018-9464 J9 IEEE T MAGN JI IEEE Trans. Magn. PD NOV PY 1991 VL 27 IS 6 BP 5352 EP 5354 DI 10.1109/20.278836 PN 2 PG 3 WC Engineering, Electrical & Electronic; Physics, Applied SC Engineering; Physics GA HB661 UT WOS:A1991HB66100232 ER PT J AU CHUNG, R WEBER, R JILES, DC AF CHUNG, R WEBER, R JILES, DC TI A TERFENOL BASED MAGNETOSTRICTIVE DIODE-LASER MAGNETOMETER SO IEEE TRANSACTIONS ON MAGNETICS LA English DT Article; Proceedings Paper CT 5TH JOINT MMM-INTERMAG CONF CY JUN 18-21, 1991 CL PITTSBURGH, PA SP AKASHIC MEMORIES, ALLEGHENY LUDLUM, ALLIED SIGNAL, APPL MAGNET, ARMCO, ANORD ENGN, BASF AG, CERAM MAGNET, CRUCIBLE MAT, DASTEK AB A simple, rugged Terfenol based magnetostrictive magnetometer prototype has been developed. Experiments were performed to determine the optimum operating point for the transducer and to study the characteristic of the diode laser sensor. A laboratory prototype has been constructed and evaluated under different field strengths and frequencies. Nonlinear responses were observed and their origin examined. The device has an ultimate sensitivity of 160 x 10(-6) A/m(= 2 micro+Oe). C1 IOWA STATE UNIV SCI & TECHNOL,AMES LAB,AMES,IA 50011. IOWA STATE UNIV SCI & TECHNOL,DEPT MAT SCI & ENGN,AMES,IA 50011. RP CHUNG, R (reprint author), IOWA STATE UNIV SCI & TECHNOL,DEPT ELECT & COMP ENGN,AMES,IA 50011, USA. RI Jiles, David/H-9548-2012 NR 4 TC 11 Z9 13 U1 0 U2 0 PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017-2394 SN 0018-9464 J9 IEEE T MAGN JI IEEE Trans. Magn. PD NOV PY 1991 VL 27 IS 6 BP 5358 EP 5360 DI 10.1109/20.278838 PN 2 PG 3 WC Engineering, Electrical & Electronic; Physics, Applied SC Engineering; Physics GA HB661 UT WOS:A1991HB66100234 ER PT J AU SCHWARTZ, RW TUTTLE, BA DOUGHTY, DH LAND, CE GOODNOW, DC HERNANDEZ, CL ZENDER, TJ MARTINEZ, SL AF SCHWARTZ, RW TUTTLE, BA DOUGHTY, DH LAND, CE GOODNOW, DC HERNANDEZ, CL ZENDER, TJ MARTINEZ, SL TI PREPARATION AND CHARACTERIZATION OF CHEMICALLY DERIVED (PB, LA)TIO3 THIN-FILMS SO IEEE TRANSACTIONS ON ULTRASONICS FERROELECTRICS AND FREQUENCY CONTROL LA English DT Article ID PRECURSORS AB Ferroelectric lead lanthanum titanate (PLT) thin films with composition varying from pure PbTiO3 to PLT 25/100 (0 to 25 mol% La) were prepared by spin-casting 0.25 M solutions containing metallo-organic precursors of Pb, La, and Ti. The as-deposited amorphous films were crystallized into the perovskite structure by heat treatment at temperatures between 450 and 650-degrees-C. The dielectric and ferroelectric properties of the thin (410 nm) films were characterized. The dielectric constants of the films varied from approximately 80 to approximately 690 for La contents varying from 0 to 25 mol%, respectively. Dissipation factors varied from approximately 0.03 to approximately 0.09 over the same compositional range. We also studied the temperature dependence of the dielectric properties in order to determine the effects of La content on the Curie point (T(c)). We found that, as expected, T(c) decreased with increasing La concentration. Coercive field and remanent polarization also decreased with increased La concentration. Hysteresis loops became slim and more symmetric with increasing La content. C1 UNIV NEW MEXICO,DEPT CHEM ENGN,ALBUQUERQUE,NM 87131. RP SCHWARTZ, RW (reprint author), SANDIA NATL LABS,DIV ELECTR CERAM,ALBUQUERQUE,NM 87185, USA. NR 12 TC 20 Z9 21 U1 1 U2 3 PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017-2394 SN 0885-3010 J9 IEEE T ULTRASON FERR JI IEEE Trans. Ultrason. Ferroelectr. Freq. Control PD NOV PY 1991 VL 38 IS 6 BP 677 EP 683 DI 10.1109/58.108869 PG 7 WC Acoustics; Engineering, Electrical & Electronic SC Acoustics; Engineering GA GW460 UT WOS:A1991GW46000023 PM 18267634 ER PT J AU MARUSIC, M BAJZER, Z FREYER, JP VUKPAVLOVIC, S AF MARUSIC, M BAJZER, Z FREYER, JP VUKPAVLOVIC, S TI MODELING AUTOSTIMULATION OF GROWTH IN MULTICELLULAR TUMOR SPHEROIDS SO INTERNATIONAL JOURNAL OF BIO-MEDICAL COMPUTING LA English DT Article DE GROWTH MODELS; NESTED MODELS; MULTICELLULAR TUMOR SPHEROIDS; POSITIVE FEEDBACK ID CELLS AB We report the development of a growth model that includes the positive regulatory feedback by cell-cell interactions. It is based on the model by Wheldon et al. (J Theor Biol, 38 (1973) 627) and Cox et al, (Comput Biomed Res, 13 (1980) 445) and is characterized by biologically interpretable parameters. We applied the model to growth of multicellular spheroids formed by V79 Chinese hamster fibroblasts. The new model resulted in a statistically sound fit. We compared the applicability of our model, of the model by Wheldon et al and Cox et al. as well as of the related model by Piantadosi (Comput Biomed Res, 18 (1985) 220). We affiliated the models with each other within a nesting scheme and compared their respective fits to data by the F-test. Our model yielded a fit statistically equivalent to the fit by the model of Piantadosi. However, in distinction to other models, the estimated cellular doubling time in our model agreed better with the respective experimentally determined value. C1 MAYO CLIN & MAYO FDN,DIV DEV ONCOL RES,ROCHESTER,MN 55905. MAYO CLIN & MAYO FDN,DEPT BIOCHEM & MOLEC BIOL,ROCHESTER,MN 55905. UNIV CALIF LOS ALAMOS SCI LAB,DIV LIFE SCI,LOS ALAMOS,NM 87545. FU NCI NIH HHS [CA36535, CA45312] NR 26 TC 15 Z9 15 U1 0 U2 2 PU ELSEVIER SCI IRELAND LTD PI CLARE PA CUSTOMER RELATIONS MANAGER, BAY 15, SHANNON INDUSTRIAL ESTATE CO, CLARE, IRELAND SN 0020-7101 J9 INT J BIOMED COMPUT JI Int. J. Bio-Med. Comput. PD NOV PY 1991 VL 29 IS 2 BP 149 EP 158 DI 10.1016/0020-7101(91)90005-Y PG 10 WC Computer Science, Interdisciplinary Applications; Computer Science, Theory & Methods; Engineering, Biomedical; Medical Informatics SC Computer Science; Engineering; Medical Informatics GA GN082 UT WOS:A1991GN08200005 PM 1757165 ER PT J AU RAJU, GVS ZHOU, J KISNER, RA AF RAJU, GVS ZHOU, J KISNER, RA TI HIERARCHICAL FUZZY CONTROL SO INTERNATIONAL JOURNAL OF CONTROL LA English DT Article AB In a conventional rule based fuzzy control system, the rules are of the following form: if (condition) then (action), and all rules are essentially in a random order. The number of rules increases exponentially as the number of the system variables, on which the fuzzy rules are based, is increased. In this paper, the rules are structured in a hierarchical way so that the total number of rules will be a linear function of the system variables. The hierarchical fuzzy control algorithm developed in this paper is applied to control the feedwater flow to a steam generator of a power plant. The simulation results show that the hierarchical fuzzy controller yields superior performance over the conventional PID controller. C1 OAK RIDGE NATL LAB,DIV INSTRUMENTAT & CONTROL,OAK RIDGE,TN 37831. OHIO UNIV,DEPT ELECT & COMP ENGN,ATHENS,OH 45701. NR 8 TC 187 Z9 225 U1 0 U2 14 PU TAYLOR & FRANCIS LTD PI LONDON PA ONE GUNDPOWDER SQUARE, LONDON, ENGLAND EC4A 3DE SN 0020-7179 J9 INT J CONTROL JI Int. J. Control PD NOV PY 1991 VL 54 IS 5 BP 1201 EP 1216 DI 10.1080/00207179108934205 PG 16 WC Automation & Control Systems SC Automation & Control Systems GA GK627 UT WOS:A1991GK62700008 ER PT J AU MCLUCKEY, SA GLISH, GL ASANO, KG BARTMESS, JE AF MCLUCKEY, SA GLISH, GL ASANO, KG BARTMESS, JE TI PROTONATED WATER AND PROTONATED METHANOL CLUSTER DECOMPOSITIONS IN A QUADRUPOLE ION TRAP SO INTERNATIONAL JOURNAL OF MASS SPECTROMETRY AND ION PROCESSES LA English DT Article ID GAS-PHASE; MASS-SPECTROMETRY; EQUILIBRIA AB Electrospray mass spectra of water and methanol have been studied with a quadrupole ion trap operated with background gas pressures of 2 x 10(-5)-2 x 10(-3) Torr. In each case, the most abundant ions observed consist of protonated clusters of varying size, e.g. (H2O)nH+ in which n ranges up into the twenties. For clusters of n > 6 or so, rapid desolvation is observed. For intermediate values of n, the desolvation rate constants can be readily measured in the typical time frame of a quadrupole ion trap experiment. The internal temperatures of the cluster ions can be estimated from the known thermochemical parameters and the measured decomposition rate constants. In all cases, the temperature exceeds that of the bath gas but is significantly less than 1000 K. It is also noted that the ion temperature is inversely proportional to the logarithm of the bath gas pressure. C1 UNIV TENNESSEE,DEPT CHEM,KNOXVILLE,TN 37996. RP MCLUCKEY, SA (reprint author), OAK RIDGE NATL LAB,DIV ANALYT CHEM,OAK RIDGE,TN 37831, USA. RI McLuckey, Scott/B-2203-2009; Asano, Keiji/L-3164-2016 OI McLuckey, Scott/0000-0002-1648-5570; Asano, Keiji/0000-0003-2254-3586 NR 32 TC 26 Z9 26 U1 0 U2 6 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0168-1176 J9 INT J MASS SPECTROM JI Int. J. Mass Spectrom. Ion Process. PD NOV 1 PY 1991 VL 109 BP 171 EP 186 DI 10.1016/0168-1176(91)85103-S PG 16 WC Physics, Atomic, Molecular & Chemical; Spectroscopy SC Physics; Spectroscopy GA GN866 UT WOS:A1991GN86600012 ER PT J AU BARTELT, MC PRIVMAN, V AF BARTELT, MC PRIVMAN, V TI KINETICS OF IRREVERSIBLE MONOLAYER AND MULTILAYER ADSORPTION SO INTERNATIONAL JOURNAL OF MODERN PHYSICS B LA English DT Review AB We review recent theoretical developments of microscopic lattice and continuum models of the kinetics of irreversible monolayer and multilayer surface adsorption. Such models have been used to describe adhesion and reaction processes of colloidal particles and proteins at solid surfaces. Theoretical results surveyed here include the void-filling rate equation approach, exact results for low dimensionalities, the mean-field theory, and large-time kinetics arguments. Numerical simulations serving to test and supplement the analytical theories, are reviewed as well. We also elucidate the crossover from the discrete to continuum behavior, analyzed via scaling arguments in the large-time limit of the deposition kinetics. RP BARTELT, MC (reprint author), IOWA STATE UNIV SCI & TECHNOL,INST PHYS RES & TECHNOL,AMES,IA 50011, USA. NR 0 TC 112 Z9 112 U1 0 U2 5 PU WORLD SCIENTIFIC PUBL CO PTE LTD PI SINGAPORE PA JOURNAL DEPT PO BOX 128 FARRER ROAD, SINGAPORE 9128, SINGAPORE SN 0217-9792 J9 INT J MOD PHYS B JI Int. J. Mod. Phys. B PD NOV PY 1991 VL 5 IS 18 BP 2883 EP 2907 DI 10.1142/S0217979291001127 PG 25 WC Physics, Applied; Physics, Condensed Matter; Physics, Mathematical SC Physics GA GR185 UT WOS:A1991GR18500002 ER PT J AU HASSELBACHER, CA SCHWARTZ, GP GLASS, JD LAWS, WR AF HASSELBACHER, CA SCHWARTZ, GP GLASS, JD LAWS, WR TI NEUROPHYSIN-NEUROHYPOPHYSEAL HORMONE INTERACTIONS - STUDIES USING A DANSYLATED VASOTOCIN ANALOG SO INTERNATIONAL JOURNAL OF PEPTIDE AND PROTEIN RESEARCH LA English DT Article DE BINDING; DANSYL; FLUORESCENCE; ISOFORMS; NEUROHYPOPHYSEAL HORMONES; NEUROPHYSIN; STEADY-STATE; TIME-RESOLVED ID PROTEOLYTICALLY MODIFIED NEUROPHYSINS; NUCLEAR MAGNETIC-RESONANCE; BOVINE NEUROPHYSIN; SELF-ASSOCIATION; PEPTIDE INTERACTIONS; AFFINITY-CHROMATOGRAPHY; MOLECULAR-PROPERTIES; BINDING; OXYTOCIN; VASOPRESSIN AB We have synthesized a neurohypophyseal hormone analogue containing an extrinsic fluorescence probe by linking a dansyl (DNS) group to the epsilon-amino group of the lysine at residue 8 of vasotocin. The fluorescence properties of this analogue have been characterized by steady-state and time-resolved spectroscopic methods and compared with those of epsilon-DNS-lysine and the dansylated carboxyl terminal tripeptide Pro-Lys(DNS)-GlyNH2. The binding of this hormone analogue to purified isoforms of bovine neurophysins, the natural carrier proteins of the neurohypophyseal hormones, results in changes in several fluorescence parameters of the dansyl probe. These changes include an increase in intensity and average lifetime, a shift of the emission band to higher energies, and an increase in the emission anisotropy. Anisotropy changes have been used to determine dissociation constants for binding to these neurophysin isoforms. Based on the changes in the fluorescence properties of the dansyl probe, the dansyl group itself interacts with the protein. The degree of the dansyl-neurophysin interaction, however, appears to be different for the full sequence isoform of neurophysin I and the Val89 isoform of neurophysin II. C1 CUNY MT SINAI SCH MED,DEPT BIOCHEM,1 GUSTAVE LEVY PL,NEW YORK,NY 10029. BROOKHAVEN NATL LAB,DEPT MED,UPTON,NY 11973. FU NIDDK NIH HHS [DK-12925, DK-10080, DK-39548] NR 62 TC 3 Z9 3 U1 0 U2 0 PU MUNKSGAARD INT PUBL LTD PI COPENHAGEN PA 35 NORRE SOGADE, PO BOX 2148, DK-1016 COPENHAGEN, DENMARK SN 0367-8377 J9 INT J PEPT PROT RES JI Int. J. Pept. Protein Res. PD NOV PY 1991 VL 38 IS 5 BP 459 EP 468 PG 10 WC Biochemistry & Molecular Biology SC Biochemistry & Molecular Biology GA GT974 UT WOS:A1991GT97400008 PM 1820072 ER PT J AU PERNOT, P LESTER, WA AF PERNOT, P LESTER, WA TI MULTIDIMENSIONAL WAVE-PACKET ANALYSIS - SPLITTING METHOD FOR TIME-RESOLVED PROPERTY DETERMINATION SO INTERNATIONAL JOURNAL OF QUANTUM CHEMISTRY LA English DT Article ID REACTIVE SCATTERING; SYSTEMS AB The splitting method is an approach for preventing unphysical behavior of a wave-packet at the edges of its coordinate space representation grid. We examine here the possibilities and limits of using this method to perform time-resolved analysis of the products of molecular processes. C1 UNIV PARIS 11,GRP CHIM QUANT,PHYSICO CHIM RAYONNEMENTS LAB,F-91405 ORSAY,FRANCE. UNIV CALIF BERKELEY,DEPT CHEM,BERKELEY,CA 94720. RP PERNOT, P (reprint author), UNIV CALIF BERKELEY LAWRENCE BERKELEY LAB,DIV MAT & CHEM SCI,1 CYCLOTRON RD,BERKELEY,CA 94720, USA. RI PERNOT, Pascal/C-2643-2008 OI PERNOT, Pascal/0000-0001-8586-6222 NR 13 TC 30 Z9 30 U1 0 U2 0 PU JOHN WILEY & SONS INC PI NEW YORK PA 605 THIRD AVE, NEW YORK, NY 10158-0012 SN 0020-7608 J9 INT J QUANTUM CHEM JI Int. J. Quantum Chem. PD NOV PY 1991 VL 40 IS 5 BP 577 EP 588 DI 10.1002/qua.560400502 PG 12 WC Chemistry, Physical; Mathematics, Interdisciplinary Applications; Physics, Atomic, Molecular & Chemical SC Chemistry; Mathematics; Physics GA GJ719 UT WOS:A1991GJ71900001 ER PT J AU KESSLER, ML PITLUCK, S PETTI, P CASTRO, JR AF KESSLER, ML PITLUCK, S PETTI, P CASTRO, JR TI INTEGRATION OF MULTIMODALITY IMAGING DATA FOR RADIOTHERAPY TREATMENT PLANNING SO INTERNATIONAL JOURNAL OF RADIATION ONCOLOGY BIOLOGY PHYSICS LA English DT Article DE MULTIMODALITY IMAGING; IMAGE REGISTRATION; TREATMENT PLANNING AB This paper describes computational techniques to permit the quantitative integration of magnetic resonance (MR), positron emission tomography (PET), and x-ray computed tomography (CT) imaging data sets. These methods are used to incorporate unique diagnostic information provided by PET and MR imaging into CT-based treatment planning for radiotherapy of intracranial tumors and vascular malformations. Integration of information from the different imaging modalities is treated as a two-step process. The first step is to determine the set of geometric parameters relating the coordinates of two imaging data sets. No universal method for determining these parameters is appropriate because of the diversity of contemporary imaging methods and data formats. Most situations can be handled by one of the four different techniques described. These four methods make use of specific geometric objects contained in the two data sets to determine the parameters. These objects are: (a) anatomical and/or fiducial points, (b) attached line markers, (c) anatomical surfaces, and (d) outlines of anatomical structures. The second step involves using the derived transformation to transfer outlines of treatment volumes and/or anatomical structures drawn on the images of one imaging study to the images of another study, usually the treatment planning CT. Solid modelling and image processing techniques have been adapted and developed further to accomplish this task. Clinical examples and phantom studies are presented which verify the different aspects of these techniques and demonstrate the accuracy with which they can be applied. Clinical use of these techniques for treatment planning has resulted in improvements in localization of treatment volumes and critical structures in the brain. These improvements have allowed greater sparing of normal tissues and more precise delivery of energy to the desired irradiation volume. It is believed that these improvements will have a positive impact on the outcome of radiation therapy. C1 UNIV CALIF BERKELEY,GRAD GRP BIOPHYS & MED PHYS,BERKELEY,CA 94720. UNIV CALIF BERKELEY,LAWRENCE BERKELEY LAB,DIV RES MED & RADIAT BIOPHYS,BERKELEY,CA 94720. FU NCI NIH HHS [1P01 CA19138] NR 12 TC 110 Z9 110 U1 0 U2 2 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD, ENGLAND OX5 1GB SN 0360-3016 J9 INT J RADIAT ONCOL JI Int. J. Radiat. Oncol. Biol. Phys. PD NOV PY 1991 VL 21 IS 6 BP 1653 EP 1667 PG 15 WC Oncology; Radiology, Nuclear Medicine & Medical Imaging SC Oncology; Radiology, Nuclear Medicine & Medical Imaging GA GR727 UT WOS:A1991GR72700033 PM 1938575 ER PT J AU SOUTHWORTH, F DALE, VH ONEILL, RV AF SOUTHWORTH, F DALE, VH ONEILL, RV TI CONTRASTING PATTERNS OF LAND-USE IN RONDONIA, BRAZIL - SIMULATING THE EFFECTS ON CARBON RELEASE SO INTERNATIONAL SOCIAL SCIENCE JOURNAL LA English DT Article ID DEFORESTATION RP SOUTHWORTH, F (reprint author), OAK RIDGE NATL LAB,DIV ECOL,OAK RIDGE,TN 37831, USA. NR 37 TC 4 Z9 4 U1 1 U2 1 PU BLACKWELL PUBL LTD PI OXFORD PA 108 COWLEY RD, OXFORD, OXON, ENGLAND OX4 1JF SN 0020-8701 J9 INT SOC SCI J JI Int. Soc. Sci. J. PD NOV PY 1991 VL 43 IS 4 BP 681 EP 698 PG 18 WC Social Sciences, Interdisciplinary SC Social Sciences - Other Topics GA GU250 UT WOS:A1991GU25000007 ER PT J AU NATESAN, K AF NATESAN, K TI MATERIALS PERFORMANCE IN ADVANCED FOSSIL TECHNOLOGIES SO JOM-JOURNAL OF THE MINERALS METALS & MATERIALS SOCIETY LA English DT Review ID CORROSION AB A number of advanced technologies are being developed to convert coal into clean fuels for use as a feedstock in chemical plants and for power generation. From the standpoint of component materials, the environments created by coal conversion and combustion in these technologies and their interactions with materials are of interest. This article identifies several modes of materials degradation and possible mechanisms for metal wastage. Available data on the performance of materials in several of the environments are highlighted, and examples of promising research activities to improve the corrosion resistance of materials are presented. RP NATESAN, K (reprint author), ARGONNE NATL LAB,ARGONNE,IL 60439, USA. NR 23 TC 9 Z9 9 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 NOV PY 1991 VL 43 IS 11 BP 61 EP 67 PG 7 WC Materials Science, Multidisciplinary; Metallurgy & Metallurgical Engineering; Mineralogy; Mining & Mineral Processing SC Materials Science; Metallurgy & Metallurgical Engineering; Mineralogy; Mining & Mineral Processing GA GT745 UT WOS:A1991GT74500010 ER PT J AU DAMJANOVIC, VP SIMONOV, AY AF DAMJANOVIC, VP SIMONOV, AY TI BEAN-LIVINGSTON BARRIER IN UNIAXIAL SUPERCONDUCTORS SO JOURNAL DE PHYSIQUE I LA English DT Article ID ANISOTROPIC SUPERCONDUCTORS; MAGNETIC-PROPERTIES; FIELD AB The role of surface barrier on the inclined vortex penetration into uniaxial superconductors is investigated. It is shown that the field of the barrier disappearance is practically independent on an angle of magnetic field inclination. Peculiarities of the vortex penetration into the layered superconductors are discussed. The rotation of vortex direction near the surface is predicted. C1 TITOGRAD UNIV,DEPT MATH & PHYS,MONTE NEGRO,YUGOSLAVIA. IOWA STATE UNIV SCI & TECHNOL,AMES LAB,AMES,IA 50011. IOWA STATE UNIV SCI & TECHNOL,DEPT PHYS,AMES,IA 50011. RP DAMJANOVIC, VP (reprint author), MV LOMONOSOV STATE UNIV,DEPT PHYS,HIGH TC SUPERCONDUCT LAB,MOSCOW 117234,USSR. RI Simonov, Andrei/C-1697-2015 OI Simonov, Andrei/0000-0001-6452-0214 NR 13 TC 8 Z9 8 U1 0 U2 0 PU EDITIONS PHYSIQUE PI LES ULIS CEDEX PA Z I DE COURTABOEUF AVE 7 AV DU HOGGAR, BP 112, 91944 LES ULIS CEDEX, FRANCE SN 1155-4304 J9 J PHYS I JI J. Phys. I PD NOV PY 1991 VL 1 IS 11 BP 1639 EP 1647 PG 9 WC Physics, Multidisciplinary SC Physics GA GM548 UT WOS:A1991GM54800008 ER PT J AU THOMPSON, LR COLLINS, GJ DOYLE, BL KNAPP, JA AF THOMPSON, LR COLLINS, GJ DOYLE, BL KNAPP, JA TI X-RAY-DIFFRACTION CHARACTERIZATION OF SILICON-ON-INSULATOR FILMS SO JOURNAL OF APPLIED PHYSICS LA English DT Article ID OXYGEN IMPLANTATION; SI FILMS; RECRYSTALLIZATION AB Silicon-on-insulator layers produced by the processes of oxygen implantation into single-crystal silicon substrates, zone melt recrystallization of deposited polysilicon films, and silicon epitaxy on sapphire substrates have been examined by an improved x-ray-diffraction technique. The technique incorporates a position-sensitive x-ray detector placed on the 2-theta arm of a conventional double-crystal diffractometer, thus allowing the measurement of scattered x-ray intensity in both the incident and diffracted x-ray beam angles simultaneously. X-ray scattering intensity maps plotted in k space reveal the relative strain and mosaic spread of the silicon overlayers with respect to the (001) silicon substrates. Oxygen-implanted films and graphite strip recrystallized films exhibit mosaic spreads (< +/- 0.08-degrees and +/- 0.05-degrees, respectively) approaching that of bulk single-crystal Si. The electron-beam-recrystallized films exhibit significantly larger mosaic spreads (almost-equal-to +/- 0.52-degrees). These silicon overlayer films all exhibit similar perpendicular strain values with an average of approximately 0.08%. Silicon layers produced by both zone melt recrystallization techniques contain a preferential tilt of the diffraction planes along the recrystallization scan direction with respect to the underlying (001)-oriented silicon substrate. Silicon-on-sapphire samples exhibit both a large mosaic spread (+/- 0.18-degrees) and a large perpendicular strain (0.13%). These x-ray results are consistent with crystalline data taken by backscattered electron images and Rutherford ion backscattering. C1 SANDIA NATL LABS,ALBUQUERQUE,NM 87185. RP THOMPSON, LR (reprint author), COLORADO STATE UNIV,FT COLLINS,CO 80523, USA. NR 15 TC 5 Z9 5 U1 0 U2 3 PU AMER INST PHYSICS PI WOODBURY PA CIRCULATION FULFILLMENT DIV, 500 SUNNYSIDE BLVD, WOODBURY, NY 11797-2999 SN 0021-8979 J9 J APPL PHYS JI J. Appl. Phys. PD NOV 1 PY 1991 VL 70 IS 9 BP 4760 EP 4769 DI 10.1063/1.349068 PG 10 WC Physics, Applied SC Physics GA GN971 UT WOS:A1991GN97100013 ER PT J AU STEVENS, A HSU, CL ISHAM, KR LARIMER, FW AF STEVENS, A HSU, CL ISHAM, KR LARIMER, FW TI FRAGMENTS OF THE INTERNAL TRANSCRIBED SPACER-1 OF PRE-RIBOSOMAL-RNA ACCUMULATE IN SACCHAROMYCES-CEREVISIAE LACKING 5'-]3' EXORIBONUCLEASE-1 SO JOURNAL OF BACTERIOLOGY LA English DT Note ID RIBOSOMAL-RNA; YEAST; PURIFICATION; SITES AB The portion of the internal transcribed spacer 1 found on 20S pre-rRNA accumulates in Saccharomyces cerevisiae lacking 5' --> 3' exoribonuclease 1, showing that an endonucleolytic cleavage at the 3' terminus of 18S rRNA is involved in the 20S pre-rRNA to 18S mature rRNA conversion. Smaller fragments of the spacer sequence are also found. The exoribonuclease may be involved as a cytoplasmic RNase in the hydrolysis of the spacer. RP STEVENS, A (reprint author), OAK RIDGE NATL LAB,DIV BIOL,OAK RIDGE,TN 37831, USA. FU NCI NIH HHS [CA 09336]; NIGMS NIH HHS [GM42144] NR 23 TC 97 Z9 97 U1 0 U2 0 PU AMER SOC MICROBIOLOGY PI WASHINGTON PA 1325 MASSACHUSETTS AVENUE, NW, WASHINGTON, DC 20005-4171 SN 0021-9193 J9 J BACTERIOL JI J. Bacteriol. PD NOV PY 1991 VL 173 IS 21 BP 7024 EP 7028 PG 5 WC Microbiology SC Microbiology GA GM344 UT WOS:A1991GM34400050 PM 1938905 ER PT J AU DAI, S AF DAI, S TI SIMPLE DERIVATION OF THE HELLER-MCCONNELL EQUATION SO JOURNAL OF CHEMICAL EDUCATION LA English DT Article ID PHYSICAL-CHEMISTRY EXPERIMENT; RADICALS RP DAI, S (reprint author), OAK RIDGE NATL LAB,DIV ANALYT CHEM,OAK RIDGE,TN 37831, USA. RI Dai, Sheng/K-8411-2015 OI Dai, Sheng/0000-0002-8046-3931 NR 11 TC 2 Z9 2 U1 1 U2 2 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 SN 0021-9584 J9 J CHEM EDUC JI J. Chem. Educ. PD NOV PY 1991 VL 68 IS 11 BP 894 EP 895 PG 2 WC Chemistry, Multidisciplinary; Education, Scientific Disciplines SC Chemistry; Education & Educational Research GA GU972 UT WOS:A1991GU97200014 ER PT J AU PRATT, ST DEHMER, PM DEHMER, JL AF PRATT, ST DEHMER, PM DEHMER, JL TI PHOTOELECTRON-SPECTROSCOPY FROM THE A1AU STATE OF ACETYLENE - THE BENDING VIBRATIONS OF C2H2+X2-PI-U SO JOURNAL OF CHEMICAL PHYSICS LA English DT Article ID X BAND SYSTEM; ROTATION CONSTANTS; WAVELENGTH BANDS; RYDBERG STATES; ION; H-2; PREDISSOCIATION; AUTOIONIZATION; DISTRIBUTIONS; IONIZATION AB Photoelectron spectra are reported for one-photon resonant, two-photon ionization of acetylene via a number of vibronic levels of the A approximately 1A(u) state. Because the A approximately 1A(u) state is trans bent and the X 2-PI-u ground state of the ion is linear, ionization from the A approximately 1A(u) levels produces a long progression in the trans-bending vibration of the ion. The X 2-PI-u state is split by the Renner-Teller interaction along the trans-bending coordinate; the analysis of the photoelectron spectra allows the determination of the Renner-Teller parameters and leads to reassignments of the cis and trans-bending vibrations in earlier photoelectron studies. RP PRATT, ST (reprint author), ARGONNE NATL LAB,ARGONNE,IL 60439, USA. NR 39 TC 37 Z9 37 U1 1 U2 3 PU AMER INST PHYSICS PI WOODBURY PA CIRCULATION FULFILLMENT DIV, 500 SUNNYSIDE BLVD, WOODBURY, NY 11797-2999 SN 0021-9606 J9 J CHEM PHYS JI J. Chem. Phys. PD NOV 1 PY 1991 VL 95 IS 9 BP 6238 EP 6248 DI 10.1063/1.461570 PG 11 WC Chemistry, Physical; Physics, Atomic, Molecular & Chemical SC Chemistry; Physics GA GL753 UT WOS:A1991GL75300005 ER PT J AU KOIZUMI, H SCHATZ, GC GORDON, MS AF KOIZUMI, H SCHATZ, GC GORDON, MS TI AN ANALYTICAL REPRESENTATION OF THE LOWEST POTENTIAL-ENERGY SURFACE FOR THE REACTION O(3P)+HCL(X1-SIGMA+)-]OH(X2-PI)+CL(2P) SO JOURNAL OF CHEMICAL PHYSICS LA English DT Article ID ATOM TRANSFER-REACTIONS; ARRHENIUS PARAMETERS; RATE COEFFICIENTS; HCL; SCATTERING; O(P-3); KINETICS; DYNAMICS; CL+HCL; O(3P) AB We present a new analytical representation of the lowest 3A" energy surface for the reaction O(3P) + HCl(X 1-SIGMA+) --> OH(X 2-PI) + Cl(2P). This surface is derived by fitting ab initio calculations, and adjustments are made to the barrier height so that rate constants derived from accurate quantum scattering calculations match the room temperature thermal rate constants. Contributions to thermal and state resolved rate constants arising from reaction on the lowest 3A' surface are also considered. Comparisons of thermal and state resolved rate constants with experiment are good except at high temperature where the 3A' contributions are significant. C1 ARGONNE NATL LAB,THEORET CHEM GRP,ARGONNE,IL 60439. N DAKOTA STATE UNIV,DEPT CHEM,FARGO,ND 58105. RP KOIZUMI, H (reprint author), NORTHWESTERN UNIV,DEPT CHEM,EVANSTON,IL 60208, USA. NR 35 TC 77 Z9 78 U1 0 U2 4 PU AMER INST PHYSICS PI WOODBURY PA CIRCULATION FULFILLMENT DIV, 500 SUNNYSIDE BLVD, WOODBURY, NY 11797-2999 SN 0021-9606 J9 J CHEM PHYS JI J. Chem. Phys. PD NOV 1 PY 1991 VL 95 IS 9 BP 6421 EP 6428 DI 10.1063/1.461562 PG 8 WC Chemistry, Physical; Physics, Atomic, Molecular & Chemical SC Chemistry; Physics GA GL753 UT WOS:A1991GL75300024 ER PT J AU LARESE, JZ HASTINGS, JM PASSELL, L SMITH, D RICHTER, D AF LARESE, JZ HASTINGS, JM PASSELL, L SMITH, D RICHTER, D TI ROTATIONAL TUNNELING OF METHANE ON MGO SURFACES - A NEUTRON-SCATTERING STUDY SO JOURNAL OF CHEMICAL PHYSICS LA English DT Letter ID CRYSTALLINE FIELD; PHASE-TRANSITIONS; SOLID METHANES; SYMMETRIC TOPS; ENERGY-LEVELS; CH4 C1 PENN STATE UNIV, DEPT CHEM, HAZLETON, PA 18201 USA. FORSCHUNGSZENTRUM JULICH, INST FESTKORPERFORSCH, W-5170 JULICH 1, GERMANY. RP LARESE, JZ (reprint author), BROOKHAVEN NATL LAB, UPTON, NY 11973 USA. RI Richter, Dieter/H-3701-2013 OI Richter, Dieter/0000-0003-0719-8470 NR 21 TC 43 Z9 43 U1 0 U2 0 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 NOV 1 PY 1991 VL 95 IS 9 BP 6997 EP 7000 DI 10.1063/1.461044 PG 4 WC Chemistry, Physical; Physics, Atomic, Molecular & Chemical SC Chemistry; Physics GA GL753 UT WOS:A1991GL75300084 ER PT J AU WURZ, P LYKKE, KR AF WURZ, P LYKKE, KR TI DELAYED ELECTRON-EMISSION FROM PHOTOEXCITED C60 SO JOURNAL OF CHEMICAL PHYSICS LA English DT Letter ID CARBON; C-60; CLUSTERS; SPECTRA C1 ARGONNE NATL LAB,DIV CHEM,ARGONNE,IL 60439. RP WURZ, P (reprint author), ARGONNE NATL LAB,DIV MAT SCI,ARGONNE,IL 60439, USA. NR 17 TC 87 Z9 87 U1 0 U2 4 PU AMER INST PHYSICS PI WOODBURY PA CIRCULATION FULFILLMENT DIV, 500 SUNNYSIDE BLVD, WOODBURY, NY 11797-2999 SN 0021-9606 J9 J CHEM PHYS JI J. Chem. Phys. PD NOV 1 PY 1991 VL 95 IS 9 BP 7008 EP 7012 DI 10.1063/1.461046 PG 5 WC Chemistry, Physical; Physics, Atomic, Molecular & Chemical SC Chemistry; Physics GA GL753 UT WOS:A1991GL75300087 ER PT J AU MILLER, DL AF MILLER, DL TI UPDATE ON SAFETY OF DIAGNOSTIC ULTRASONOGRAPHY SO JOURNAL OF CLINICAL ULTRASOUND LA English DT Article DE DIAGNOSTIC ULTRASOUND; BIOEFFECTS; SAFETY STANDARDS ID PULSED ULTRASOUND; EXPOSURE; INVITRO; OUTPUT AB Safety considerations for diagnostic ultrasonography have gradually changed as new instruments, not only more powerful in performance but also in ultrasonic exposure, have come into use. Nonthermal cavitational bioeffects of ultrasound have a problematic role in risk assessment for clinical applications, but should serve as cautionary reminders that there potentially could be low-level risks. Recent analyses have indicated possible areas of concern related to the thermal mechanism of bioeffects, particularly if trends for higher intensities continue into the future. The most critical area of concern is in fetal examinations, for which developing bone is unavoidably heated by relatively powerful pulsed-Doppler beams. Fortunately, because of the threshold nature of thermal damage, development of flexible, use-driven upper limits on output should completely resolve this impending safety problem. The ultrasonics community is now responding to these evolving safety issues with improved instrument characterization standards, new bioeffects research, and initiatives in continuing education for sonographers. RP MILLER, DL (reprint author), PACIFIC NW LAB, DEPT BIOL & CHEM, RICHLAND, WA 99352 USA. FU NCI NIH HHS [CA42947] NR 39 TC 26 Z9 26 U1 0 U2 1 PU JOHN WILEY & SONS INC PI NEW YORK PA 605 THIRD AVE, NEW YORK, NY 10158-0012 SN 0091-2751 J9 J CLIN ULTRASOUND JI J. Clin. Ultrasound PD NOV-DEC PY 1991 VL 19 IS 9 BP 531 EP 540 DI 10.1002/jcu.1870190903 PG 10 WC Acoustics; Radiology, Nuclear Medicine & Medical Imaging SC Acoustics; Radiology, Nuclear Medicine & Medical Imaging GA GL631 UT WOS:A1991GL63100002 PM 1663122 ER PT J AU COHEN, BI WILLIAMS, TJ AF COHEN, BI WILLIAMS, TJ TI SEMIIMPLICIT PARTICLE SIMULATION OF KINETIC PLASMA PHENOMENA SO JOURNAL OF COMPUTATIONAL PHYSICS LA English DT Note RP COHEN, BI (reprint author), UNIV CALIF LAWRENCE LIVERMORE NATL LAB,LIVERMORE,CA 94550, USA. NR 14 TC 2 Z9 2 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 NOV PY 1991 VL 97 IS 1 BP 224 EP 234 PG 11 WC Computer Science, Interdisciplinary Applications; Physics, Mathematical SC Computer Science; Physics GA GL783 UT WOS:A1991GL78300010 ER PT J AU BUDINGER, TF FISCHER, H HENTSCHEL, D REINFELDER, HE SCHMITT, F AF BUDINGER, TF FISCHER, H HENTSCHEL, D REINFELDER, HE SCHMITT, F TI PHYSIOLOGICAL-EFFECTS OF FAST OSCILLATING MAGNETIC-FIELD GRADIENTS SO JOURNAL OF COMPUTER ASSISTED TOMOGRAPHY LA English DT Article DE MAGNETIC RESONANCE IMAGING; TECHNIQUES; MAGNETIC RESONANCE IMAGING; APPARATUS AND EQUIPMENT; ECHO PLANAR IMAGING; MAGNETIC RESONANCE IMAGING; PHYSICS AND INSTRUMENTATION ID CARDIAC FIBRILLATION THRESHOLDS; VENTRICULAR-FIBRILLATION; SPATIAL LOCALIZATION; STIMULATION; HEART; CURRENTS AB To evaluate the physiological thresholds of neuromuscular stimulation relevant to very fast NMR imaging studies that use gradient switching at frequencies of 1-2 kHz and a maximum magnetic field of up to 10 mT, a series of studies were done with human volunteers using an experimental echo planar gradient coil set. The threshold for induction of localized and momentary sensations in the human back and abdomen for 10 subjects is 60 T/s for sinusoidally oscillating magnetic fields at 1.27 kHz. The threshold relates to an E field of 6 V/m and is shown to vary with number of oscillations and frequency in accord with theory. Using a simple model of E field induction, the threshold for stimulation of cardiac electrical events should be > 4 times this value. C1 SIEMENS AG,MED ENGN GRP,W-8520 ERLANGEN,GERMANY. RP BUDINGER, TF (reprint author), UNIV CALIF BERKELEY,LAWRENCE BERKELEY LAB,MS 55-121,1 CYCLOTRON RD,BERKELEY,CA 94720, USA. NR 28 TC 73 Z9 73 U1 0 U2 0 PU LIPPINCOTT-RAVEN PUBL PI PHILADELPHIA PA 227 EAST WASHINGTON SQ, PHILADELPHIA, PA 19106 SN 0363-8715 J9 J COMPUT ASSIST TOMO JI J. Comput. Assist. Tomogr. PD NOV-DEC PY 1991 VL 15 IS 6 BP 909 EP 914 DI 10.1097/00004728-199111000-00001 PG 6 WC Radiology, Nuclear Medicine & Medical Imaging SC Radiology, Nuclear Medicine & Medical Imaging GA GN911 UT WOS:A1991GN91100001 PM 1939767 ER PT J AU CARY, JW MCBRIDE, JF SIMMONS, CS AF CARY, JW MCBRIDE, JF SIMMONS, CS TI ASSAY OF ORGANIC LIQUID CONTENTS IN PREDOMINANTLY WATER-WET UNCONSOLIDATED POROUS-MEDIA SO JOURNAL OF CONTAMINANT HYDROLOGY LA English DT Article AB Immiscible organic liquids may be extracted from moist soil or other hydrophilic porous media by shaking a suspension of water and soil in a glass jar with a piece of porous polyethylene. The water displaces the organic liquid from the predominantly hydrophilic sample and the hydrophobic polyethylene preferentially absorbs the organic liquid, excluding water unless there is a detergent associated with the organic. Because most soils have some hydrophobic surfaces, the extraction of organic liquids by displacement with water is not quite complete. A correction is therefore made in the assay method by including samples with known organic liquid content as controls. The amount of organic liquid not displaced from the control samples can also be used to indicate the extent of hydrophobic sites in predominantly water-wet porous media. Organic liquid extractions were made by using three soils and two organic liquids. The standard deviation among replicated extractions was 0.010 g organic liquid. By applying a correction to the mass of organic liquid recovered, the assay accuracy was +/- 0.001 g organic liquid/g soil with 20.0-g oven-dry soil samples. It is likely that this assay method could be scaled up and used as a remediation method for removing and recovering organic liquids from earth excavated from spill or leak sites. RP CARY, JW (reprint author), PACIFIC NW LAB, RICHLAND, WA 99352 USA. NR 0 TC 5 Z9 5 U1 0 U2 0 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0169-7722 J9 J CONTAM HYDROL JI J. Contam. Hydrol. PD NOV PY 1991 VL 8 IS 2 BP 135 EP 142 DI 10.1016/0169-7722(91)90012-P PG 8 WC Environmental Sciences; Geosciences, Multidisciplinary; Water Resources SC Environmental Sciences & Ecology; Geology; Water Resources GA GU445 UT WOS:A1991GU44500002 ER PT J AU SMITH, NR BENSON, S LARABELL, CA AF SMITH, NR BENSON, S LARABELL, CA TI AN INVITRO EXTRACELLULAR-MATRIX MODEL SYSTEM TO VISUALIZE WHOLE CELLS WITH INTERMEDIATE VOLTAGE ELECTRON-MICROSCOPY (IVEM) SO JOURNAL OF ELECTRON MICROSCOPY TECHNIQUE LA English DT Note C1 UNIV CALIF BERKELEY LAWRENCE BERKELEY LAB,INTERMEDIATE VOLTAGE ELECTRON MICROSCOPY FACIL,BERKELEY,CA 94720. RP SMITH, NR (reprint author), CALIF STATE UNIV HAYWARD,DEPT BIOL SCI,HAYWARD,CA 94542, USA. NR 4 TC 0 Z9 0 U1 0 U2 1 PU WILEY-LISS PI NEW YORK PA DIV JOHN WILEY & SONS INC 605 THIRD AVE, NEW YORK, NY 10158-0012 SN 0741-0581 J9 J ELECTRON MICR TECH PD NOV PY 1991 VL 19 IS 3 BP 380 EP 381 DI 10.1002/jemt.1060190313 PG 2 WC Biology; Microscopy SC Life Sciences & Biomedicine - Other Topics; Microscopy GA GJ661 UT WOS:A1991GJ66100011 PM 1795190 ER PT J AU HOWARTH, RB AF HOWARTH, RB TI INTERGENERATIONAL COMPETITIVE EQUILIBRIA UNDER TECHNOLOGICAL UNCERTAINTY AND AN EXHAUSTIBLE RESOURCE CONSTRAINT SO JOURNAL OF ENVIRONMENTAL ECONOMICS AND MANAGEMENT LA English DT Article; Proceedings Paper CT 1990 ANNUAL MEETING OF THE ASSOC FOR PUBLIC POLICY ANALYSIS AND MANAGEMENT CY OCT 18-20, 1990 CL SAN FRANCISCO, CA SP ASSOC PUBLIC POLICY ANAL & MANAGEMENT ID OPTIMALITY; FERTILITY; MARKETS RP HOWARTH, RB (reprint author), UNIV CALIF BERKELEY,LAWRENCE BERKELEY LAB,BERKELEY,CA 94720, USA. OI Howarth, Richard/0000-0003-3182-7345 NR 26 TC 24 Z9 25 U1 0 U2 2 PU ACADEMIC PRESS INC JNL-COMP SUBSCRIPTIONS PI SAN DIEGO PA 525 B ST, STE 1900, SAN DIEGO, CA 92101-4495 SN 0095-0696 J9 J ENVIRON ECON MANAG JI J.Environ.Econ.Manage. PD NOV PY 1991 VL 21 IS 3 BP 225 EP 243 DI 10.1016/0095-0696(91)90028-H PG 19 WC Business; Economics; Environmental Studies SC Business & Economics; Environmental Sciences & Ecology GA GL787 UT WOS:A1991GL78700002 ER PT J AU ENGLIN, J MENDELSOHN, R AF ENGLIN, J MENDELSOHN, R TI A HEDONIC TRAVEL COST-ANALYSIS FOR VALUATION OF MULTIPLE COMPONENTS OF SITE QUALITY - THE RECREATION VALUE OF FOREST MANAGEMENT SO JOURNAL OF ENVIRONMENTAL ECONOMICS AND MANAGEMENT LA English DT Article ID DEMAND MODEL; TIME RP ENGLIN, J (reprint author), PACIFIC NW LAB, 500 NE MULTNOMAH, SUITE 650, PORTLAND, OR 97232 USA. NR 22 TC 40 Z9 44 U1 5 U2 10 PU ACADEMIC PRESS INC JNL-COMP SUBSCRIPTIONS PI SAN DIEGO PA 525 B ST, STE 1900, SAN DIEGO, CA 92101-4495 SN 0095-0696 J9 J ENVIRON ECON MANAG JI J.Environ.Econ.Manage. PD NOV PY 1991 VL 21 IS 3 BP 275 EP 290 DI 10.1016/0095-0696(91)90031-D PG 16 WC Business; Economics; Environmental Studies SC Business & Economics; Environmental Sciences & Ecology GA GL787 UT WOS:A1991GL78700005 ER PT J AU RAILSBACK, SF BOWNDS, JM AF RAILSBACK, SF BOWNDS, JM TI INDEXING GAS TRANSFER IN SELF-AERATED FLOWS - DISCUSSION SO JOURNAL OF ENVIRONMENTAL ENGINEERING-ASCE LA English DT Article C1 OAK RIDGE NATL LAB,DIV ENERGY,OAK RIDGE,TN 37831. RP RAILSBACK, SF (reprint author), OAK RIDGE NATL LAB,DIV ENVIRONM SCI,OAK RIDGE,TN 37831, USA. OI Railsback, Steven/0000-0002-5923-9847 NR 1 TC 1 Z9 1 U1 0 U2 1 PU ASCE-AMER SOC CIVIL ENG PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017-2398 SN 0733-9372 J9 J ENVIRON ENG-ASCE JI J. Environ. Eng.-ASCE PD NOV-DEC PY 1991 VL 117 IS 6 BP 866 EP 867 DI 10.1061/(ASCE)0733-9372(1991)117:6(866) PG 2 WC Engineering, Environmental; Engineering, Civil; Environmental Sciences SC Engineering; Environmental Sciences & Ecology GA GQ745 UT WOS:A1991GQ74500013 ER PT J AU GUCKERT, JB RINGELBERG, DB WHITE, DC HANSON, RS BRATINA, BJ AF GUCKERT, JB RINGELBERG, DB WHITE, DC HANSON, RS BRATINA, BJ TI MEMBRANE FATTY-ACIDS AS PHENOTYPIC MARKERS IN THE POLYPHASIC TAXONOMY OF METHYLOTROPHS WITHIN THE PROTEOBACTERIA SO JOURNAL OF GENERAL MICROBIOLOGY LA English DT Article ID METHANOL-UTILIZING BACTERIA; BIOMARKERS; PROFILES; ACETATE AB A polyphasic approach to bacterial taxonomy attempts to integrate phylogenetic relationships with phenotypic marker analysis. This study describes the application of membrane fatty acids as a phenotypic marker for methylotrophs. Detailed phospholipid, ester-linked fatty acid (PLFA) profiles are reported for 17 methylotrophic eubacterial strains. These profiles includes verification of double bond positions and geometries, both critical features for this analysis. Multivariate cluster analysis was used to indicate groupings of these strains along with literature values of both methylotrophs and non-methylotrophs based on the PLFA phenotype. Like many phenotypic characteristics, PLFA profiles were influenced by environmental conditions. The instabilities displayed, however, were predictable from physiological studies including increased trans/cis and cyclopropyl/cis ratios. Cluster analysis of PLFA profiles generated by separate investigators with different culture conditions indicated reproducibility by strain and species. The PLFA phenotype relationships compare favourably with phylogenetic associations based on 16S rRNA data for methylotrophs and will continue to be a valuable phenotypic marker for Proteobacteria taxonomy. 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 MINNESOTA,GRAY FRESHWATER BIOL INST,NAVARRE,MN 55392. NR 36 TC 99 Z9 103 U1 2 U2 14 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 NOV PY 1991 VL 137 BP 2631 EP 2641 PN 11 PG 11 WC Microbiology SC Microbiology GA GR075 UT WOS:A1991GR07500018 PM 1783909 ER PT J AU HESSE, M BIRN, J AF HESSE, M BIRN, J TI ON DIPOLARIZATION AND ITS RELATION TO THE SUBSTORM CURRENT WEDGE SO JOURNAL OF GEOPHYSICAL RESEARCH-SPACE PHYSICS LA English DT Article ID NEAR-EARTH MAGNETOTAIL; MAGNETOSPHERIC SUBSTORMS; SOLAR-WIND; GENERATION AB Within the framework of our three-dimensional self-consistent MHD model of magnetotail activity we investigate near-Earth properties of magnetospheric substorms. Particular emphasis is on the generation mechanism and the three-dimensional aspects of the B(z) increase which is commonly called magnetic field dipolarization, and its spatial and temporal relation to the field-aligned currents of the substorm current wedge and the current reduction and diversion. We find that the dipolarization can be understood as the flux pileup due to the slowing down of the fast earthward flows carrying reconnected flux from the reconnection region. The gradients of B(z) at the dawn and dusk flanks of the dipolarization region contribute to the region 1 field-aligned current system of the substorm current wedge. The major contribution, however, is found to be associated with the shear between the y and x components of the magnetic field. We also find that the region where the cross-tail current is reduced ("disrupted") and diverted is located tailward from the dipolarization region. Our results indicate that the apparent tailward propagation of dipolarization effects does not support the conclusion that the underlying process is initiated further earthward. RP HESSE, M (reprint author), UNIV CALIF LOS ALAMOS SCI LAB,MS D438,LOS ALAMOS,NM 87545, USA. RI Hesse, Michael/D-2031-2012 NR 14 TC 103 Z9 104 U1 0 U2 4 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 NOV 1 PY 1991 VL 96 IS A11 BP 19417 EP 19426 DI 10.1029/91JA01953 PG 10 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA GM857 UT WOS:A1991GM85700015 ER PT J AU BIRN, J AF BIRN, J TI THE BOUNDARY-VALUE PROBLEM OF MAGNETOTAIL EQUILIBRIUM SO JOURNAL OF GEOPHYSICAL RESEARCH-SPACE PHYSICS LA English DT Article ID EARTHS MAGNETOTAIL; MAGNETOSPHERE; TAIL; SIMULATION AB The equilibrium problem for the Earth's magnetotail is discussed under the assumption that the boundary of the tail can be prescribed or derived from the force balance with the solar wind. A general solution of this problem is presented for the two-dimensional case, where the dependence on the y coordinate and the presence of B(y) axe neglected. These solutions axe further generalized to include the y dependence (but no B(y)) and an open magnetopause. In this formulation, a solution can be obtained by integration when the magnetopause boundary a(x, y), the total pressure function p(x), and the magnetic flux distribution A(b)(x, y) at the magnetopause are prescribed. Certain restrictions, however, may limit the free choice of these functions to yield physically reasonable, real solutions. When the interaction with the solar wind is included, the boundary location can no longer be chosen freely but follows from the force balance of the magnetotail with the solar wind. For a simplified description of this force balance a differential equation for the boundary location is derived, which general an earlier result by Coroniti and Kennel (1972). It is shown that solutions of this differential equation are bounded by a maximum tail width if the plasma sheet thickness is limited. Several explicit solutions are presented, illustrating cases with and without tail flaring in the z direction, and including the restrictions of the force balance with the solar wind and of the conservation laws of adiabatic convection in a steady configuration. RP BIRN, J (reprint author), UNIV CALIF LOS ALAMOS SCI LAB,MS D438,LOS ALAMOS,NM 87545, USA. NR 20 TC 19 Z9 19 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 NOV 1 PY 1991 VL 96 IS A11 BP 19441 EP 19450 DI 10.1029/91JA01955 PG 10 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA GM857 UT WOS:A1991GM85700017 ER PT J AU DROST, MK WHITE, MD AF DROST, MK WHITE, MD TI NUMERICAL PREDICTIONS OF LOCAL ENTROPY GENERATION IN AN IMPINGING JET SO JOURNAL OF HEAT TRANSFER-TRANSACTIONS OF THE ASME LA English DT Article DE JETS; NUMERICAL METHODS; THERMODYNAMICS AND 2ND LAW AB Local entropy generation rates related to viscous dissipation and heat transfer across finite temperature differences can be calculated for isotropic and Newtonian fluids from the temperature and velocity fields in a thermal process. This study consisted of the development of a numerical procedure for the prediction of local entropy generation rates and the application of that procedure to convective heat transfer associated with a fluid jet impinging on a heated wall. The procedure involved expanding an existing computation fluid dynamics computer code to include the numerical calculation of local entropy generation. The modified code was bench-marked against analytical solutions and was then used to simulate a cold fluid jet impinging on a hot wall. The results show that the calculation of local entropy generation is feasible and can provide useful information. C1 PACIFIC NW LAB, RICHLAND, WA 99352 USA. NR 16 TC 36 Z9 36 U1 0 U2 6 PU ASME-AMER SOC MECHANICAL ENG PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 SN 0022-1481 J9 J HEAT TRANS-T ASME JI J. Heat Transf.-Trans. ASME PD NOV PY 1991 VL 113 IS 4 BP 823 EP 829 DI 10.1115/1.2911209 PG 7 WC Thermodynamics; Engineering, Mechanical SC Thermodynamics; Engineering GA HP761 UT WOS:A1991HP76100005 ER PT J AU CHEUNG, FB SHIAH, SW CHO, DH BAKER, L AF CHEUNG, FB SHIAH, SW CHO, DH BAKER, L TI TURBULENT NATURAL-CONVECTION IN A HORIZONTAL LAYER OF SMALL-PRANDTL-NUMBER FLUID SO JOURNAL OF HEAT TRANSFER-TRANSACTIONS OF THE ASME LA English DT Article DE ENCLOSURE FLOWS; LIQUID METALS; NATURAL CONVECTION ID THERMAL CONVECTION AB Turbulent natural convection in a horizontal layer of liquid metal confined between two infinite rigid plates is studied theoretically. The layer, with uniformly distributed energy sources in the fluid, is heated from below and cooled from above. An approximate analysis of the Boussinesq equations of motion is performed for the case of small-Prandtl-number fluids to determine the temperature profiles in three different thermal regions of the layer. By matching these profiles in the regions of overlap, analytical expressions are derived for the lower and upper surface Nusselt numbers and the dimensionless turbulent core temperature as functions of the internal and external Rayleigh numbers defined respectively in terms of the volumetric heating rate and surface-to-surface temperature difference of the layer. Comparison of the present results with heat transfer data for liquid mercury is made and found to be good. C1 PENN STATE UNIV,DEPT MECH ENGN,UNIV PK,PA 16802. ARGONNE NATL LAB,DIV REACTOR ANAL & SAFETY,ARGONNE,IL 60439. NR 14 TC 1 Z9 1 U1 1 U2 3 PU ASME-AMER SOC MECHANICAL ENG PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 SN 0022-1481 J9 J HEAT TRANS-T ASME JI J. Heat Transf.-Trans. ASME PD NOV PY 1991 VL 113 IS 4 BP 919 EP 925 DI 10.1115/1.2911222 PG 7 WC Thermodynamics; Engineering, Mechanical SC Thermodynamics; Engineering GA HP761 UT WOS:A1991HP76100018 ER PT J AU HUGLY, S KUNST, L SOMERVILLE, C AF HUGLY, S KUNST, L SOMERVILLE, C TI LINKAGE RELATIONSHIPS OF MUTATIONS THAT AFFECT FATTY-ACID COMPOSITION IN ARABIDOPSIS SO JOURNAL OF HEREDITY LA English DT Article ID ENHANCED THERMAL TOLERANCE; CHLOROPLAST ULTRASTRUCTURE; PALMITIC ACID; LEAF LIPIDS; MUTANT; DEFICIENT; PHOTOSYNTHESIS; DESATURATION; UNSATURATION; THALIANA AB Mutations at the act1, fadA, fadB, fadC, and fadD loci of Arabidopsis thaliana affect the fatty acid composition of the chloroplast membrane lipids. The mutations were mapped by measuring the fatty acid composition by gas chromatography of more than 3,300 leaf samples from individuals in segregating populations. Linkage analysis of the act1 mutant indicated that it is 35 cM from the an locus on chromosome 1. The fadA locus is on chromosome 4, where it is 18 cM from cer2 and tightly linked to ap2. The fadB locus is on chromosome 3, where it is 28 cM from gl1 and tightly linked to hy2. The fadC locus is 13 cM from ap2 and is tightly linked to cer2 on chromosome 4. The fadD locus is on chromosome 3, where it is 40 cM from gl1 and 3 cM from hy2. C1 MICHIGAN STATE UNIV,DOE,PLANT RES LAB,E LANSING,MI 48824. RI Somerville, Christopher/A-4048-2009 OI Somerville, Christopher/0000-0003-4647-0094 NR 17 TC 14 Z9 14 U1 0 U2 4 PU OXFORD UNIV PRESS INC PI CARY PA JOURNALS DEPT, 2001 EVANS RD, CARY, NC 27513 SN 0022-1503 J9 J HERED JI J. Hered. PD NOV-DEC PY 1991 VL 82 IS 6 BP 484 EP 488 PG 5 WC Evolutionary Biology; Genetics & Heredity SC Evolutionary Biology; Genetics & Heredity GA HD557 UT WOS:A1991HD55700008 ER PT J AU UNKEFER, CJ HANNERS, JL EHLER, DS AF UNKEFER, CJ HANNERS, JL EHLER, DS TI STEREOSELECTIVE SYNTHESIS OF STABLE ISOTOPE-LABELED L-ALPHA-AMINO ACIDS - CHEMOMICROBIOLOGICAL SYNTHESIS OF C-13-LABELED AND H-2-LABELED L-CYSTEINE SO JOURNAL OF LABELLED COMPOUNDS & RADIOPHARMACEUTICALS LA English DT Article DE L-[3-C-13]CYSTEINE, L-[3-H-2(2)]CYSTEINE, S-BENZYL-L-[3-C-13]CYSTEINE, S-B; BENZYL-L-[3-H-2(2)]CYSTEINE, L-[3-C-13]SERINE, AND L-[3-H-2(2)]SERINE ID TRYPTOPHAN SYNTHASE; ENZYMATIC-SYNTHESIS AB Tryptophan synthase catalyzes the nucleophilic replacement of the hydroxyl group at C-3 of L-serine. This enzyme can use benzyl mercaptan as a nucleophile in the conversion of serine to S-benzyl-L-cysteine which is deblocked by treatment with sodium in liquid ammonia to yield L-cysteine. A strain of E. coli engineered to overproduce tryptophan synthase was used in the conversion of L-serine to L-cysteine. Labeled serine was prepared biosynthetically as described previously. RP UNKEFER, CJ (reprint author), UNIV CALIF LOS ALAMOS SCI LAB,NATL STABLE ISOTOPES RESOURCE,GRP INC4,MS C345,LOS ALAMOS,NM 87545, USA. NR 7 TC 5 Z9 5 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 NOV PY 1991 VL 29 IS 11 BP 1241 EP 1246 DI 10.1002/jlcr.2580291108 PG 6 WC Biochemical Research Methods; Chemistry, Medicinal; Chemistry, Analytical SC Biochemistry & Molecular Biology; Pharmacology & Pharmacy; Chemistry GA GN884 UT WOS:A1991GN88400007 ER PT J AU UNKEFER, CJ LODWIG, SN SILKS, LA HANNERS, JL EHLER, DS GIBSON, R AF UNKEFER, CJ LODWIG, SN SILKS, LA HANNERS, JL EHLER, DS GIBSON, R TI STEREOSELECTIVE SYNTHESIS OF STABLE ISOTOPE-LABELED L-ALPHA-AMINO ACIDS - CHEMOMICROBIOLOGICAL SYNTHESIS OF L-[BETA-C-13]-TRYPTOPHAN, L-[2'-C-13]-TRYPTOPHAN, AND L-[1'-N-15]TRYPTOPHAN SO JOURNAL OF LABELLED COMPOUNDS & RADIOPHARMACEUTICALS LA English DT Article DE L-[BETA-C-13]TRYPTOPHAN; L-[BETA-C-13]TRYPTOPHAN; L-[2'-C-13]TRYPTOPHAN; L-[1'-N-15]TRYPTOPHAN; L-[BETA-C-13]SERINE; [1-N-15]INDOLE, AND [2-C-13]INDOLE ID INDOLE AB We have developed a stereospecific chemomicrobiological synthesis of labeled tryptophan. L-[3-C-13]Serine, [1-N-15]- and [2-C-13]indole were used as precursors for the synthesis of L-[beta-C-13]-, L-[1'-N-15]-, and L-[2'-C-13]tryptophan, respectively. The labeled precursors were incorporated quantitatively into tryptophan using a strain of E. coli engineered to overproduce tryptophan synthase. Labeled indoles were prepared by the base-promoted cyclization of appropriately labeled N-formyl-o-toluide; serine was prepared biosynthetically as described previously. C1 CENTRALIA COLL, DIV SCI, CENTRALIA, WA 98531 USA. RP UNKEFER, CJ (reprint author), UNIV CALIF LOS ALAMOS SCI LAB, NATL STABLE ISOTOPES RESOURCE, GROUP INC4, MS C345, LOS ALAMOS, NM 87545 USA. NR 15 TC 11 Z9 12 U1 1 U2 2 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 NOV PY 1991 VL 29 IS 11 BP 1247 EP 1256 DI 10.1002/jlcr.2580291109 PG 10 WC Biochemical Research Methods; Chemistry, Medicinal; Chemistry, Analytical SC Biochemistry & Molecular Biology; Pharmacology & Pharmacy; Chemistry GA GN884 UT WOS:A1991GN88400008 ER PT J AU MOON, RM NICKLOW, RM AF MOON, RM NICKLOW, RM TI NEUTRON-SCATTERING OF LANTHANIDE MATERIALS SO JOURNAL OF MAGNETISM AND MAGNETIC MATERIALS LA English DT Article ID Q MAGNETIC-STRUCTURE; NUCLEAR-SPIN ORDER; TEMPERATURE-DEPENDENCE; CRITICAL-BEHAVIOR; X-RAY; NEODYMIUM; PRASEODYMIUM; EXCITATIONS; DIFFRACTION; HOLMIUM AB A selected review of recent neutron scattering results on lanthanide materials is presented. Topics covered include the magnetic structures of the elemental metals, magnetic superlattices, enhanced nuclear magnetism, magnetic excitations and critical scattering. RP MOON, RM (reprint author), OAK RIDGE NATL LAB,POB 2008,OAK RIDGE,TN 37831, USA. NR 69 TC 2 Z9 2 U1 1 U2 6 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 NOV PY 1991 VL 100 IS 1-3 BP 139 EP 150 DI 10.1016/0304-8853(91)90817-T PG 12 WC Materials Science, Multidisciplinary; Physics, Condensed Matter SC Materials Science; Physics GA GX179 UT WOS:A1991GX17900010 ER PT J AU JOHNSTON, DC AF JOHNSTON, DC TI NORMAL STATE MAGNETISM OF THE HIGH-TC CUPRATE SUPERCONDUCTORS SO JOURNAL OF MAGNETISM AND MAGNETIC MATERIALS LA English DT Review ID MUON-SPIN-ROTATION; CU-O SYSTEM; SQUARE-LATTICE ANTIFERROMAGNET; NEUTRON-SCATTERING; HEISENBERG-ANTIFERROMAGNET; SINGLE-CRYSTAL; BULK SUPERCONDUCTIVITY; PHASE-TRANSITIONS; MONTE-CARLO; QUANTUM ANTIFERROMAGNETS AB Magnetic measurements of various types have played an essential role in establishing the novel normal state characteristics of high transition temperature (T(c)) superconductors with T(c) > 23 K. Among these materials, the highest T(c)'s (less-than-or-equal-to 125 K) are exhibited by the layered cuprates. In this paper, the normal state magnetic susceptibilities of the cuprates are reviewed and interpreted in the context of magnetic neutron scattering and other magnetic measurements, using the La2-xMxCuO4-type and YBa2Cu3O6+x-type materials as prototypical examples. The evolution of the magnetism upon doping the insulating antiferromagnetic "parent" compounds with x = 0 to form the high temperature superconductors is described. A recurrent property which differentiates these materials from conventional superconductors is the existence of strong antiferromagnetic correlations in the metallic state on the same sublattice of the structure in which the itinerant carriers reside. C1 IOWA STATE UNIV SCI & TECHNOL,DEPT PHYS & ASTRON,AMES,IA 50011. RP JOHNSTON, DC (reprint author), IOWA STATE UNIV SCI & TECHNOL,US DOE,AMES LAB,AMES,IA 50011, USA. NR 178 TC 71 Z9 71 U1 1 U2 6 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 NOV PY 1991 VL 100 IS 1-3 BP 218 EP 240 DI 10.1016/0304-8853(91)90822-R PG 23 WC Materials Science, Multidisciplinary; Physics, Condensed Matter SC Materials Science; Physics GA GX179 UT WOS:A1991GX17900015 ER PT J AU IKEDA, K DHAR, SK YOSHIZAWA, M GSCHNEIDNER, KA AF IKEDA, K DHAR, SK YOSHIZAWA, M GSCHNEIDNER, KA TI QUENCHING OF SPIN FLUCTUATIONS BY HIGH MAGNETIC-FIELDS SO JOURNAL OF MAGNETISM AND MAGNETIC MATERIALS LA English DT Review ID PD-NI ALLOYS; ELECTRONIC SPECIFIC-HEAT; LAVES PHASE-STRUCTURE; FERMI-LIQUID THEORY; ELECTRICAL-RESISTIVITY; FERROMAGNETIC METALS; NI3AL ALLOYS; SYSTEM UAL2; CAPACITY; TIBE2 AB The quenching of spin fluctuations by magnetic fields has been observed in heat capacity and electrical resistivity measurements at low temperatures for a series of highly exchange enhanced magnetic materials. These include: the weak itinerant electron ferromagnets Sc3In, Zr1-xHfxZn2 (0 less-than-or-equal-to x less-than-or-equal-to 0.2) and Ni3Al; the strong Pauli paramagnets RCo2(R = Sc, Y and Lu), TiBe2 and Pd1-xNix (0 less-than-or-equal-to x less-than-or-equal-to 0.01); and the heavy fermion systems CeSn3, CeSix (x almost-equal-to 1.85) and UAl2. The reported quenching of spin fluctuations in scandium and palladium by magnetic fields is reviewed, and it appears that the initial observations and conclusions are incorrect, and that fields greater than 10 and 40 T, respectively, will be necessary to quench spin fluctuations in these metals. The behaviors of these spin fluctuations in these metals. The behaviors of these spin fluctuators have been grouped into six classes. C1 TATA INST FUNDAMENTAL RES,HOMI BHABHA RD,BOMBAY 400005,INDIA. IWATE UNIV,DEPT MET,MORIOKA,IWATE 020,JAPAN. IOWA STATE UNIV SCI & TECHNOL,AMES LAB,AMES,IA 50011. IOWA STATE UNIV SCI & TECHNOL,DEPT MAT SCI & ENGN,AMES,IA 50011. NR 103 TC 55 Z9 55 U1 2 U2 18 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 NOV PY 1991 VL 100 IS 1-3 BP 292 EP 321 DI 10.1016/0304-8853(91)90826-V PG 30 WC Materials Science, Multidisciplinary; Physics, Condensed Matter SC Materials Science; Physics GA GX179 UT WOS:A1991GX17900019 ER PT J AU BADER, SD AF BADER, SD TI SMOKE SO JOURNAL OF MAGNETISM AND MAGNETIC MATERIALS LA English DT Review ID ULTRATHIN FERROMAGNETIC-FILMS; SURFACE MAGNETIC-ANISOTROPY; EPITAXIAL FE FILMS; MAGNETOOPTICAL KERR; ULTRAHIGH-VACUUM; PHASE-TRANSITION; PLASMA RESONANCE; SPIN ANISOTROPY; CHARGE-CARRIERS; MONTE-CARLO AB Research activities associated with the surface magneto-optic Kerr effect (SMOKE) are reviewed. The purpose is to stimulate interest in the range of contemporary topics in surface magnetism and magneto-optics that SMOKE has addressed. These include the quest for monolayer magnetism, the nature of the surface magnetic anisotropy, trends in the Curie temperature with film thickness, and the critical magnetization exponent at the two-dimensional phase transition. Also, a macroscopic formalism that provides insights into magneto-optics in the ultrathin limit is examined and used to simulate the properties of a number of overlayer, sandwich and superlattice film configurations of interest. Comparisons are then made to experiment and the outlook for the future is examined. RP BADER, SD (reprint author), ARGONNE NATL LAB,DIV MAT SCI,ARGONNE,IL 60439, USA. RI Bader, Samuel/A-2995-2013 NR 117 TC 198 Z9 198 U1 3 U2 48 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 NOV PY 1991 VL 100 IS 1-3 BP 440 EP 454 DI 10.1016/0304-8853(91)90833-V PG 15 WC Materials Science, Multidisciplinary; Physics, Condensed Matter SC Materials Science; Physics GA GX179 UT WOS:A1991GX17900026 ER PT J AU FREEMAN, AJ GSCHNEIDNER, KA AF FREEMAN, AJ GSCHNEIDNER, KA TI MAGNETISM IN THE NINETIES - PREFACE SO JOURNAL OF MAGNETISM AND MAGNETIC MATERIALS LA English DT Editorial Material C1 IOWA STATE UNIV SCI & TECHNOL,USDA,AMES LAB,AMES,IA 50011. RP FREEMAN, AJ (reprint author), NORTHWESTERN UNIV,DEPT PHYS & ASTRON,EVANSTON,IL 60208, USA. NR 0 TC 2 Z9 2 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 NOV PY 1991 VL 100 IS 1-3 BP R9 EP R10 DI 10.1016/0304-8853(91)90808-N PG 2 WC Materials Science, Multidisciplinary; Physics, Condensed Matter SC Materials Science; Physics GA GX179 UT WOS:A1991GX17900001 ER PT J AU RAMESH, R INAM, A HWANG, DM RAVI, TS SANDS, T XI, XX WU, XD LI, Q VENKATESAN, T KILAAS, R AF RAMESH, R INAM, A HWANG, DM RAVI, TS SANDS, T XI, XX WU, XD LI, Q VENKATESAN, T KILAAS, R TI THE ATOMIC-STRUCTURE OF GROWTH INTERFACES IN Y-BA-CU-O THIN-FILMS SO JOURNAL OF MATERIALS RESEARCH LA English DT Article ID SINGLE-CRYSTAL MGO; YBA2CU3O7-X-PRBA2CU3O7-Y HETEROSTRUCTURES; SUPERCONDUCTING FILMS; DEFECT STRUCTURE; SUBSTRATE AB We have examined the atomic structure of growth interfaces in thin films of Y-Ba-Cu-O grown on [001] perovskite or cubic substrates. At substrate heater temperatures in the range of 780-820-degrees-C c-axis oriented growth is observed on these substrates. On SrTiO3, the first layer appears to be either a BaO or CuO2 plane while on LaAlO3 the first layer appears to be a CuO chain layer. The mismatch on the a-b plane is accommodated by the formation of interface dislocations. Defects on the substrate surface propagate as defects in the film. These defects are primarly translational boundaries and in some cases second phases. At lower substrate heater temperatures, i.e., 650-700-degrees-C, a, b-axis growth dominates. Defects and steps on the substrate surface are more detrimental in the growth of a, b-axis oriented films, since they tend to favor the nucleation of c-axis oriented domains. This is ascribed to the ledge mechanism of c-axis film growth, for which the surface steps are good nucleation sites. C1 RUTGERS STATE UNIV,PISCATAWAY,NJ 08854. UNIV CALIF BERKELEY,LAWRENCE BERKELEY LAB,NATL CTR ELECTRON MICROSCOPY,BERKELEY,CA 94720. RP RAMESH, R (reprint author), BELL COMMUN RES INC,RED BANK,NJ 07701, USA. RI Sands, Timothy/D-2133-2009; Venkatesan, Thirumalai/E-1667-2013 OI Sands, Timothy/0000-0001-9718-6515; NR 24 TC 57 Z9 58 U1 1 U2 5 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 NOV PY 1991 VL 6 IS 11 BP 2264 EP 2271 DI 10.1557/JMR.1991.2264 PG 8 WC Materials Science, Multidisciplinary SC Materials Science GA GM828 UT WOS:A1991GM82800004 ER PT J AU RICKMAN, JM PHILLPOT, SR WOLF, D WOODRASKA, DL YIP, S AF RICKMAN, JM PHILLPOT, SR WOLF, D WOODRASKA, DL YIP, S TI ON THE MECHANISM OF GRAIN-BOUNDARY MIGRATION IN METALS - A MOLECULAR-DYNAMICS STUDY SO JOURNAL OF MATERIALS RESEARCH LA English DT Article ID STRUCTURE-ENERGY CORRELATION; INSITU OBSERVATIONS; FCC METALS; SIMULATION; DISLOCATIONS; TRANSITION; KINETICS; PLANES AB The migration of a (100) theta = 43.6-degrees (SIGMA-29) twist grain boundary is observed during the course of a molecular-dynamics simulation. The atomic-level details of the migration are investigated by determining the time dependence of the planar structure factor, a function of the planar interparticle bond angles, and the location of the center of a mass of planes near the grain boundary. It is found that a migration step consists of local bond rearrangements which, when the simulation cell is made large enough, produce domain-like structures in the migrating plane. Although no overall sliding is observed during migration, a local sliding of the planes near the migrating grain boundary accompanies the migration process. It is suggested that a three-dimensional cloud of thermally produced Frenkel-like point defects near the boundary accompanies, and facilitates, its migration. C1 MIT,DEPT NUCL ENGN,CAMBRIDGE,MA 02139. RP RICKMAN, JM (reprint author), ARGONNE NATL LAB,DIV MAT SCI,ARGONNE,IL 60439, USA. RI Phillpot, Simon/J-9117-2012; OI Phillpot, Simon/0000-0002-7774-6535 NR 37 TC 17 Z9 18 U1 0 U2 6 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 NOV PY 1991 VL 6 IS 11 BP 2291 EP 2304 DI 10.1557/JMR.1991.2291 PG 14 WC Materials Science, Multidisciplinary SC Materials Science GA GM828 UT WOS:A1991GM82800008 ER PT J AU COSTANTINO, M FIRPO, C AF COSTANTINO, M FIRPO, C TI HIGH-PRESSURE COMBUSTION SYNTHESIS OF ALUMINUM NITRIDE SO JOURNAL OF MATERIALS RESEARCH LA English DT Article AB We report initial results on the synthesis of monolithic aluminum nitride by burning Al-AlN mixtures in high pressure nitrogen. The objective is to synthesize economically large, near-theoretical density AlN parts. In this work, we begin with compacted mixtures of 10-mu-m Al and 3-mu-m AlN powder formed into 7.62 cm diameter by 3.81 cm thick disks having densities up to 60% of theoretical. Then, at N2 pressures up to 180 MPa (26 000 psi), we ignite the disk on one face. The fraction of Al converted to AlN, density, and severity of macroscopic cracking vary with N2 pressure and heat transfer from the sample. Presently, products are inhomogeneous, showing regions of relatively high porosity, regions with no porosity but with AlN in a matrix of Al, and regions of nearly theoretical density AlN. RP COSTANTINO, M (reprint author), UNIV CALIF LAWRENCE LIVERMORE NATL LAB,LIVERMORE,CA 94550, USA. NR 12 TC 30 Z9 30 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 NOV PY 1991 VL 6 IS 11 BP 2397 EP 2402 DI 10.1557/JMR.1991.2397 PG 6 WC Materials Science, Multidisciplinary SC Materials Science GA GM828 UT WOS:A1991GM82800021 ER PT J AU GAO, Y MERKLE, KL CHANG, HLM ZHANG, TJ LAM, DJ AF GAO, Y MERKLE, KL CHANG, HLM ZHANG, TJ LAM, DJ TI MICROSTRUCTURE OF TIO2 RUTILE THIN-FILMS DEPOSITED ON (11-2BAR0) ALPHA-AL2O3 SO JOURNAL OF MATERIALS RESEARCH LA English DT Article ID CHEMICAL VAPOR-DEPOSITION AB TiO2 rutile thin films grown on (1120BAR) sapphire (alpha-Al2O3) by the MOCVD technique have been characterized by transmission electron microscopy (TEM) and high resolution electron microscopy (HREM). The TiO2 rutile thin films grew on the sapphire with two epitaxial orientations. The epitaxial orientation relationships between the rutile films (R) and the sapphire substrate (S) were found to be (1) (101)[010]R parallel-to (1120BAR)[0001]S and (2) (200)[010]R parallel-to (1120BAR)[0001]S. Detailed atomic structures of near-interface regions have been investigated by HREM, providing a clear picture of the initial stage of film growth. HREM images show that about 70% of the nuclei at the interface are the (101) rutile, but most of them are very small, about 5 nm (or 2% of the film thickness) in the growth direction. The film growth was dominated by the (200) orientation. Nucleation and growth of the films will be discussed in terms of the lattice mismatch at the interface and growth rates along the two orientations. Planar defects such as twin boundaries and special grain boundaries are commonly observed in the films, especially in regions close to the substrate. The twin plane and twinning direction are {101} and [101], respectively. Special grain boundaries are found to be correlated with nucleation and twinning. RP GAO, Y (reprint author), ARGONNE NATL LAB,DIV MAT SCI,ARGONNE,IL 60439, USA. NR 16 TC 19 Z9 21 U1 0 U2 8 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 NOV PY 1991 VL 6 IS 11 BP 2417 EP 2426 DI 10.1557/JMR.1991.2417 PG 10 WC Materials Science, Multidisciplinary SC Materials Science GA GM828 UT WOS:A1991GM82800024 ER PT J AU AUBERT, JH SYLWESTER, AP AF AUBERT, JH SYLWESTER, AP TI MORPHOLOGICAL CHARACTERIZATION OF MICROCELLULAR CARBON FOAMS SO JOURNAL OF MATERIALS SCIENCE LA English DT Article ID LOW-DENSITY AB Microcellular carbon foams have been prepared by the high-temperature carbonization of polyacrylonitrile (PAN) foams in an inert atmosphere. The PAN precursor foams were first prepared by thermally induced phase separation of PAN solutions followed by gelation/extraction or freezing/freeze-drying processes. The resulting carbon foams have low densities and open-celled morphologies. We have developed two complementary techniques to characterize objectively carbon foam morphologies, BET surface area measurements and mercury porosimetry. These two measurement techniques, when used in conjunction with known stereological rules, allow us to calculate densities and average cell sizes or cell size distributions. As a bonus, values of the bulk modulus for low-density carbon foams also can be determined from mercury porosimetry. Unlike other techniques, our determinations do not require carefully prepared surfaces (such as for microscopy) or an assumed morphological model (required for most other techniques). RP AUBERT, JH (reprint author), SANDIA NATL LABS,ALBUQUERQUE,NM 87185, USA. NR 13 TC 14 Z9 14 U1 0 U2 5 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 NOV 1 PY 1991 VL 26 IS 21 BP 5741 EP 5752 DI 10.1007/BF01130110 PG 12 WC Materials Science, Multidisciplinary SC Materials Science GA GP518 UT WOS:A1991GP51800010 ER PT J AU VOKOS, SP AF VOKOS, SP TI MULTIPARAMETER DEFORMATIONS OF GL(N) AND JORDAN-SCHWINGER CONSTRUCTIONS SO JOURNAL OF MATHEMATICAL PHYSICS LA English DT Article ID YANG-BAXTER EQUATION; SU(2) GROUP; QUANTUM; SUPERGROUP; ANALOG AB The covariant differential calculus on the quantum hyperplane acted on by GL(X;qij) (N) is interpreted as a deformed Heisenberg algebra (holomorphically realized on a polynomial basis) and the corresponding quantum algebra is constructed through the Jordan-Schwinger construction. For N greater-than-or-equal-to 3 this quantum algebra is shown to give quadratic constraints among the generators. However, for N = 2 this construction is elevated to a Hopf algebra by finding simple comultiplication rules. This is seen to be equivalent to the Woronowicz-type two-parameter deformation of Schirrmacher et al. [Z. Phys. C 49, 317 (1991)] as well as the Drinfeld-Jimbo deformation [V. G. Drinfeld, in Proceedings of the International Congress of Mathematicians, Berkeley (Academic, New York, 1986), Vol. 1, pp. 798-820; M. Jimbo, Lett. Math. Phys. 10, 63 (1985); M. Jimbo, Lett. Math. Phys. 11, 247 (1986)]. RP VOKOS, SP (reprint author), ARGONNE NATL LAB,DIV HIGH ENERGY PHYS,ARGONNE,IL 60439, USA. NR 34 TC 10 Z9 10 U1 0 U2 0 PU AMER INST PHYSICS PI WOODBURY PA CIRCULATION FULFILLMENT DIV, 500 SUNNYSIDE BLVD, WOODBURY, NY 11797-2999 SN 0022-2488 J9 J MATH PHYS JI J. Math. Phys. PD NOV PY 1991 VL 32 IS 11 BP 2979 EP 2985 DI 10.1063/1.529041 PG 7 WC Physics, Mathematical SC Physics GA GL513 UT WOS:A1991GL51300006 ER PT J AU KHEYFETS, A MILLER, WA AF KHEYFETS, A MILLER, WA TI THE BOUNDARY OF A BOUNDARY PRINCIPLE IN FIELD-THEORIES AND THE ISSUE OF AUSTERITY OF THE LAWS OF PHYSICS SO JOURNAL OF MATHEMATICAL PHYSICS LA English DT Article AB The boundary of a boundary principle has been suggested by J. A. Wheeler as a realization of the austerity idea in field theories. This principle is described in three basic field theories-electrodynamics, Yang-Mills theory, and general relativity. It is demonstrated that it supplies a unified geometric interpretation of the source current in each of the three theories in terms of a generalized E. Cartan moment of rotation. The extent to which the boundary of a boundary principle represents the austerity principle is discussed. It is concluded that it works in a way analogous to thermodynamic relations and it is argued that deeper principles might be needed to comprehend the nature of austerity. C1 UNIV CALIF LOS ALAMOS SCI LAB,DEPT THEORET,LOS ALAMOS,NM 87545. RP KHEYFETS, A (reprint author), N CAROLINA STATE UNIV,DEPT MATH,RALEIGH,NC 27695, USA. NR 13 TC 4 Z9 4 U1 1 U2 3 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 NOV PY 1991 VL 32 IS 11 BP 3168 EP 3175 DI 10.1063/1.529519 PG 8 WC Physics, Mathematical SC Physics GA GL513 UT WOS:A1991GL51300033 ER PT J AU DROEGE, MW FINKE, RG AF DROEGE, MW FINKE, RG TI A NOVEL TRIPEROXYNIOBIUM-CONTAINING POLYOXOANION, (SIW9(NBO2)3O37)-O-7- - SYNTHESIS, CHARACTERIZATION, CATALYTIC ALLYLIC EPOXIDATIONS WITH H2O2 AND PRELIMINARY KINETIC-STUDIES SO JOURNAL OF MOLECULAR CATALYSIS LA English DT Article ID METAL-OXIDE ANALOGS; QUATERNARY AMMONIUM TETRAKIS(DIPEROXOTUNGSTO)PHOSPHATES(3-); PEROXOTUNGSTEN HETEROPOLY ANION; ATOMICALLY DISPERSED IRIDIUM(I); EFFICIENT ALKENE EPOXIDATION; SPECIAL OXIDIZING PROPERTIES; MASS-SPECTROSCOPY FABMS; SOLVENT SOLUBLE FORMS; HYDROGEN-PEROXIDE; OXIDATIVE CLEAVAGE AB The synthesis and characterization of the previously unknown SiW9(NbO2)3O377-, a novel composition of matter containing three adjacent NbvO2 peroxide groups, is described. Also reported is a survey of the catalytic epoxidation of seven olefinic substrates with 30% aqueous H2O2 Using this heteropolyanion as a precatalyst. Additionally, the preliminary kinetic evidence presented indicates that SiW9(NbO2)3O377- ServeS as a catalyst precursor to the true catalyst, a catalytically active W, Nb or polyoxoanion fragment. C1 UNIV OREGON,DEPT CHEM,EUGENE,OR 97403. RP DROEGE, MW (reprint author), UNIV CALIF LAWRENCE LIVERMORE NATL LAB,LIVERMORE,CA 94550, USA. NR 46 TC 61 Z9 66 U1 0 U2 5 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0304-5102 J9 J MOL CATAL PD NOV 1 PY 1991 VL 69 IS 3 BP 323 EP 338 DI 10.1016/0304-5102(91)80113-H PG 16 WC Chemistry, Physical SC Chemistry GA GT258 UT WOS:A1991GT25800003 ER PT J AU SHIPMAN, RWG DENN, MM KEUNINGS, R AF SHIPMAN, RWG DENN, MM KEUNINGS, R TI MECHANICS OF THE FALLING PLATE EXTENSIONAL RHEOMETER SO JOURNAL OF NON-NEWTONIAN FLUID MECHANICS LA English DT Article DE EXTENSIONAL FLOW; POLYMER SOLUTIONS; RHEOMETRY AB The low-rate falling-plate extensional rheometer experiments by Sridhar and coworkers on a mobile polymer solution were simulated using a free-surface finite-element code which accounts for gravity and surface tension. There is a reverse flow near the plates which is caused by the interaction between gravitational and surface tension forces, causing a delay in the development of the uniform cylindrical column and a difference between the local and imposed extension rates during the early stages of the experiment. C1 UNIV CALIF BERKELEY,LAWRENCE BERKELEY LAB,DEPT CHEM ENGN,BERKELEY,CA 94720. CATHOLIC UNIV LOUVAIN,UNITE MECAN APPL,B-1348 LOUVAIN,BELGIUM. RP SHIPMAN, RWG (reprint author), UNIV CALIF BERKELEY,LAWRENCE BERKELEY LAB,CTR ADV MAT,BERKELEY,CA 94720, USA. NR 7 TC 38 Z9 38 U1 0 U2 1 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0377-0257 J9 J NON-NEWTON FLUID JI J. Non-Newton. Fluid Mech. PD NOV PY 1991 VL 40 IS 3 BP 281 EP 288 DI 10.1016/0377-0257(91)87013-N PG 8 WC Mechanics SC Mechanics GA GR996 UT WOS:A1991GR99600002 ER PT J AU CLINARD, FW FOLTYN, EM EWING, RC AF CLINARD, FW FOLTYN, EM EWING, RC TI STORED ENERGY IN NATURAL ZIRCONOLITE AND ITS SYNTHETIC COUNTERPART AFTER ALPHA-RECOIL SELF-IRRADIATION DAMAGE SO JOURNAL OF NUCLEAR MATERIALS LA English DT Article ID PU-238-SUBSTITUTED ZIRCONOLITE; CAZRTI2O7; MINERALS; SYNROC AB Zirconolite (nominally CaZrTi2O7) was fully substituted with Pu-238, resulting in the composition CaPuTi2O7. The effects of self-irradiation due to alpha decay were monitored at room temperature for times as long as 1198 days and doses as high as 1.6 x 10(26) alpha/m3, using differential thermal analysis. As storage time increased, the temperature of recovery from the damaged to the crystalline state increased and the recovery step became more abrupt. Stored energy reached a maximum of 100 J/g at 2.1 X 10(25) alpha/m3 and then decreased to half this value with further damage. Results for synthetic samples were compared with those for naturally-occurring zirconolites that had attained a damage dose of almost-equal-to 4.8 x 10(26) alpha/m3 as a result of their high Th and U contents. At high alpha decay doses the synthetic and natural materials behaved similarly, indicating the absence of major damage recovery or alteration effects for the natural mineral at ambient temperature. It is concluded that actinide-doped zirconolite and natural mineral analogues can both be used to study alpha decay damage under nuclear waste storage conditions after the initial cooling-off period. C1 UNIV NEW MEXICO, ALBUQUERQUE, NM 87131 USA. RP CLINARD, FW (reprint author), UNIV CALIF LOS ALAMOS SCI LAB, LOS ALAMOS, NM 87545 USA. NR 21 TC 5 Z9 5 U1 1 U2 3 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0022-3115 EI 1873-4820 J9 J NUCL MATER JI J. Nucl. Mater. PD NOV PY 1991 VL 185 IS 2 BP 202 EP 207 DI 10.1016/0022-3115(91)90336-6 PG 6 WC Materials Science, Multidisciplinary; Nuclear Science & Technology SC Materials Science; Nuclear Science & Technology GA GN284 UT WOS:A1991GN28400008 ER PT J AU LYKKE, KR KAY, BD AF LYKKE, KR KAY, BD TI ROTATIONAL RAINBOWS IN THE INELASTIC-SCATTERING OF N2 FROM AU(111) SO JOURNAL OF PHYSICS-CONDENSED MATTER LA English DT Article; Proceedings Paper CT 9TH INTERDISCIPLINARY SURFACE SCIENCE CONF ( ISSC-9 ) CY APR 22-24, 1991 CL SOUTHAMPTON, ENGLAND SP BRIT PETR RES, CADBURN, ELSEVIER, SHELL RES, UNILEVER RES, RON UNWIN, SCI INSTRUMENT CONSULTANT, USAF, EUROPEAN OFF AEROSP RES & DEV, VACUUM GENERATORS ID GAS-SURFACE SCATTERING; SOLID-SURFACES; ENERGY-DISTRIBUTIONS; AG(111); MODEL; NH3; MOLECULES; N-2 AB Resonantly enhanced multi-photon ionization (REMPI) laser spectroscopic and molecular beam-surface scattering techniques are coupled to study the rotationally inelastic scattering of N2 from Au(111). The scattered N2 rotational distributions are markedly non-Boltzmann and exhibit pronounced maxima at large angular momentum transfers (DELTA-J = 20 to 30). These maxima are indicative of direct rotational rainbow scattering and strongly depend upon the translational energy of the incident N2 molecular beam. The translational energy dependence of the rainbow rotational energy yields a value of 4.1 kcal mol-1 for the depth of the laterally averaged N2-Au(111) physisorption potential. C1 SANDIA NATL LABS,ALBUQUERQUE,NM 87185. RP LYKKE, KR (reprint author), ARGONNE NATL LAB,ARGONNE,IL 60439, USA. NR 21 TC 24 Z9 24 U1 1 U2 9 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 NOV PY 1991 VL 3 SU A BP S65 EP S70 DI 10.1088/0953-8984/3/S/010 PG 6 WC Physics, Condensed Matter SC Physics GA GU831 UT WOS:A1991GU83100011 ER PT J AU PAFFETT, MT HUTCHINSON, W FARR, JD PAPIN, P BEERY, JG GOTTESFELD, S FERET, J AF PAFFETT, MT HUTCHINSON, W FARR, JD PAPIN, P BEERY, JG GOTTESFELD, S FERET, J TI THE PHYSICAL AND CHEMICAL-STATE OF PHOSPHORIC-ACID FUEL-CELL ASSEMBLIES AFTER LONG-TERM OPERATION - SURFACE AND NEAR-SURFACE ANALYSIS SO JOURNAL OF POWER SOURCES LA English DT Article AB An attempt was made to correlate performance losses with materials compatibility and compositional changes in phosphoric acid fuel cell (PAFC) electrode assemblies as a function of operation time. Westinghouse PAFC stacks were run under a constant operating regime and portions of some of the single cells were analyzed after stack operation for 5000 and 16 000 h along with appropriate reference samples. The PAFC assemblies were disassembled, sectioned where appropriate and analyzed using scanning and transmission electron microscopy (SEM and TEM), Rutherford backscattering spectroscopy (RBS), electron microprobe analysis (EMP), and X-ray photoelectron spectroscopy (XPS). The profiles of the Pt catalyst in both the anode and the cathode layer did not show any preferential loss or peaking. The most pronounced change in cell composition detected following stack operation for 5000 and 16 000 h was the increase in Pt/C ratio, that was related to loss of carbon from the cathode electrocatalyst. In contrast, the anode catalyst layer maintains the same ratio of Pt:C following 16 000 h of operation. The loss of carbon is thought to occur by an electrochemical mechanism and is enhanced at the higher potentials experienced by the air cathode in the fuel cell. In addition, TEM results clearly demonstrate the well recognized phenomenon of Pt particle agglomeration in the cathode catalyst layer, which is seen to be quite substantial after 5000 h of stack operation. This behavior was not observed at the anode electrocatalyst layer. The mechanical integrity of the assemblies was found to be quite satisfactory after 5000 h, but much less so after 16 000 h. Questions regarding carbon and Pt corrosion, Pt migration, and the chemical and physical integrity of the PAFC structures are addressed and are all postulated to be contributing to the observed cell performance losses. C1 WESTINGHOUSE ELECT CORP,PITTSBURGH,PA 15236. RP PAFFETT, MT (reprint author), UNIV CALIF LOS ALAMOS SCI LAB,DIV CHEM & LASER SCI,ELECTR RES GRP,LOS ALAMOS,NM 87545, USA. NR 10 TC 9 Z9 9 U1 1 U2 4 PU ELSEVIER SCIENCE SA LAUSANNE PI LAUSANNE 1 PA PO BOX 564, 1001 LAUSANNE 1, SWITZERLAND SN 0378-7753 J9 J POWER SOURCES JI J. Power Sources PD NOV PY 1991 VL 36 IS 2 BP 137 EP 153 DI 10.1016/0378-7753(91)80010-U PG 17 WC Chemistry, Physical; Electrochemistry; Energy & Fuels; Materials Science, Multidisciplinary SC Chemistry; Electrochemistry; Energy & Fuels; Materials Science GA GH160 UT WOS:A1991GH16000003 ER PT J AU TESAR, AA AF TESAR, AA TI NONRADIATIVE PROPERTIES OF ND-3+-DOPED FLUORIDE GLASSES SO JOURNAL OF QUANTITATIVE SPECTROSCOPY & RADIATIVE TRANSFER LA English DT Article ID MULTIPHONON RELAXATION; IONS AB Intrinsic nonradiative properties of Nd3+ in six representative fluoride glasses were investigated. Both neodymium concentration quenching and multiphonon decay are dependent on the host matrix. For the fluoride systems studied, however, the concentration quenching behavior did not vary as the host composition changed. The observed quadratic dependence of decay rate on Nd concentration follows the Forster-Dexter model. RP TESAR, AA (reprint author), UNIV CALIF LAWRENCE LIVERMORE NATL LAB,POB 5508,L-462,LIVERMORE,CA 94551, USA. NR 10 TC 0 Z9 0 U1 0 U2 2 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD, ENGLAND OX5 1GB SN 0022-4073 J9 J QUANT SPECTROSC RA JI J. Quant. Spectrosc. Radiat. Transf. PD NOV PY 1991 VL 46 IS 5 BP 425 EP 431 DI 10.1016/0022-4073(91)90044-Q PG 7 WC Optics; Spectroscopy SC Optics; Spectroscopy GA GR458 UT WOS:A1991GR45800007 ER PT J AU MENDOZA, PG NIEMCZYK, TM AF MENDOZA, PG NIEMCZYK, TM TI INTERFERENCE STUDY OF THE PU(III) SPECTROPHOTOMETRIC ASSAY SO JOURNAL OF RADIOANALYTICAL AND NUCLEAR CHEMISTRY-ARTICLES LA English DT Article AB The study was undertaken to determine the immunity of the Pu(III) spectrophotometric assay to diverse species. We acquired spectra of a set of solutions containing 10 mM Pu(III), reduced with ascorbic acid-aminoguanidine in 2M HCl, and of a similar set of solutions containing a spike of test species. The initial molar ratio of plutonium to species was 10:1, and after interference it was increased to 10:0.1, etc., until no interference occurred. The species examined were element numbers 1, 9, 11-13, 17, 19, 22-31, 35, 42, 44-46, 48, 50, 53, 57, 58, 60, 62, 73, 74, 76, 77, 79, 83, 90, 92, 93, 95 and nitrate, phosphate, sulfate, and oxalic acid. C1 UNIV NEW MEXICO,DEPT CHEM,ALBUQUERQUE,NM 87131. RP MENDOZA, PG (reprint author), UNIV CALIF LOS ALAMOS SCI LAB,ANALYT CHEM GRP,MAIL STOP G740,LOS ALAMOS,NM 87545, USA. NR 14 TC 0 Z9 0 U1 0 U2 1 PU AKADEMIAI KIADO PI BUDAPEST PA PO BOX 245, H-1519 BUDAPEST, HUNGARY SN 0236-5731 J9 J RADIOAN NUCL CH AR JI J. Radioanal. Nucl. Chem.-Artic. PD NOV PY 1991 VL 152 IS 1 BP 207 EP 218 DI 10.1007/BF02042154 PG 12 WC Chemistry, Analytical; Chemistry, Inorganic & Nuclear; Nuclear Science & Technology SC Chemistry; Nuclear Science & Technology GA GU891 UT WOS:A1991GU89100020 ER PT J AU PEI, SY JORGENSEN, JD HINKS, DG ZHENG, Y RICHARDS, DR DABROWSKI, B MITCHELL, AW AF PEI, SY JORGENSEN, JD HINKS, DG ZHENG, Y RICHARDS, DR DABROWSKI, B MITCHELL, AW TI STRUCTURE AND CHEMISTRY OF BA0.6K0.4BIOY AT HIGH-TEMPERATURE SO JOURNAL OF SOLID STATE CHEMISTRY LA English DT Article ID SUPERCONDUCTIVITY; SYSTEM; BA1-XKXBIO3-Y; PEROVSKITE; COPPER C1 ARGONNE NATL LAB,DIV MAT SCI,ARGONNE,IL 60439. RP PEI, SY (reprint author), ARGONNE NATL LAB,SCI & TECHNOL CTR SUPERCONDUCT,ARGONNE,IL 60439, USA. NR 15 TC 14 Z9 14 U1 0 U2 1 PU ACADEMIC PRESS INC JNL-COMP SUBSCRIPTIONS PI SAN DIEGO PA 525 B ST, STE 1900, SAN DIEGO, CA 92101-4495 SN 0022-4596 J9 J SOLID STATE CHEM JI J. Solid State Chem. PD NOV PY 1991 VL 95 IS 1 BP 29 EP 38 DI 10.1016/0022-4596(91)90373-P PG 10 WC Chemistry, Inorganic & Nuclear; Chemistry, Physical SC Chemistry GA GL786 UT WOS:A1991GL78600004 ER PT J AU CAMPBELL, LJ ONEIL, K AF CAMPBELL, LJ ONEIL, K TI STATISTICS OF 2-DIMENSIONAL POINT VORTICES AND HIGH-ENERGY VORTEX STATES SO JOURNAL OF STATISTICAL PHYSICS LA English DT Article DE POINT VORTICES; MICROCANONICAL ENSEMBLE; NEGATIVE TEMPERATURE; THERMODYNAMIC LIMIT; 2D TURBULENCE; U-STATISTICS ID EULER EQUATIONS; MECHANICS; THERMODYNAMICS; PLASMAS; FLUIDS AB Results from the theory of U-statistics are used to characterize the microcanonical partition function of the N-vortex system in a rectangular region for large N, under various boundary conditions, and for neutral, asymptotically neutral, and nonneutral systems. Numerical estimates show that the limiting distribution is well matched in the region of major probability for N larger than 20. Implications for the thermodynamic limit are discussed. Vortex clustering is quantitatively studied via the average interaction energy between negative and positive vortices. Vortex states for which clustering is generic (in a statistical sense) are shown to result from two modeling processes: the approximation of a continuous inviscid fluid by point vortex configurations; and the modeling of the evolution of a continuous fluid at high Reynolds number by point vortex configurations, with the viscosity represented by the annihilation of close positive-negative vortex pairs. This last process, with the vortex dynamics replaced by a random walk, reproduces quite well the late-time features seen in spectral integration of the 2d Navier-Stokes equation. C1 UNIV TULSA,DEPT MATH & COMP SCI,TULSA,OK 74104. RP CAMPBELL, LJ (reprint author), UNIV CALIF LOS ALAMOS SCI LAB,DIV THEORET,LOS ALAMOS,NM 87545, USA. NR 29 TC 39 Z9 40 U1 0 U2 2 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 NOV PY 1991 VL 65 IS 3-4 BP 495 EP 529 DI 10.1007/BF01053742 PG 35 WC Physics, Mathematical SC Physics GA GR569 UT WOS:A1991GR56900006 ER PT J AU BOHRINGER, DE KUPPERMAN, DS BAILEY, JL KNOX, AE AF BOHRINGER, DE KUPPERMAN, DS BAILEY, JL KNOX, AE TI INSITU ULTRASONIC EXAMINATION OF THE INTENSE PULSED NEUTRON SOURCE (IPNS) ENRICHED URANIUM TARGET ASSEMBLY SO JOURNAL OF TESTING AND EVALUATION LA English DT Article DE NEUTRONS; PULSED NEUTRON SOURCE; ULTRASONIC MONITORING; URANIUM; URANIUM TARGET ASSEMBLY AB The Intense Pulsed Neutron Source (IPNS) at Argonne National Laboratory is one of the nation's largest and most powerful sources of pulsed neutron beams for the study of atomic and molecular structures in solids and liquids, Due to large grains, preferred crystal orientation, and high neutron flux levels, irradiation growth of the enriched uranium target is a major factor in limiting the useful lifetime of the target assembly Since predicting growth is difficult, in situ ultrasonic pulse-echo techniques are being used to periodically monitor the growth of the target assembly. Several tests have confirmed that irradiation growth of the target can be tracked and measured to an accuracy of 100-mu-m. C1 ARGONNE NATL LAB,DIV MAT & COMPONENTS,ARGONNE,IL 60439. ARGONNE NATL LAB,DIV ENGN PHYS,ARGONNE,IL 60439. RP BOHRINGER, DE (reprint author), ARGONNE NATL LAB,DIV INTENSE PULSED NEUTRON SOURCE,ARGONNE,IL 60439, USA. NR 3 TC 0 Z9 0 U1 1 U2 1 PU AMER SOC TESTING MATERIALS PI W CONSHOHOCKEN PA 100 BARR HARBOR DR, W CONSHOHOCKEN, PA 19428-2959 SN 0090-3973 J9 J TEST EVAL JI J. Test. Eval. PD NOV PY 1991 VL 19 IS 6 BP 467 EP 474 PG 8 WC Materials Science, Characterization & Testing SC Materials Science GA GN311 UT WOS:A1991GN31100007 ER PT J AU SINEX, DG MCDONALD, LP MOTT, JB AF SINEX, DG MCDONALD, LP MOTT, JB TI NEURAL CORRELATES OF NONMONOTONIC TEMPORAL ACUITY FOR VOICE ONSET TIME SO JOURNAL OF THE ACOUSTICAL SOCIETY OF AMERICA LA English DT Article ID CHINCHILLA AUDITORY-NERVE; CONSONANT-VOWEL SYLLABLES; DISCHARGE RATE REPRESENTATION; ON-TONE MASKING; SPEECH-PERCEPTION; FIBER RESPONSES; DISCRIMINATION; STIMULI; NOISE; MECHANISMS AB Human and chinchilla listeners exhibit nonmonotonic temporal acuity for speech sounds differing in voice onset time (VOT). Characteristics of the neural discharge pattern or of the stimuli themselves that might account for the pattern of temporal acuity have not been described. Responses of chinchilla auditory-nerve fibers to syllables from an alveolar VOT continuum were measured. Peak discharge rates and peak response latencies elicited by the syllables with the shortest and longest VOTs were highly variable across groups of neurons with similar characteristic frequencies. For VOTs from the middle of the continuum, peak responses were larger, and response latencies were nearly constant across the same group of neurons. Overall, the magnitude and temporal variability of the responses of populations of primary auditory neurons varied nonmonotonically with VOT, consistent with the pattern of psychophysical temporal acuity for these syllables exhibited by humans and chinchillas. Spectral analyses suggested by the pattern of neural responses indicated that synchronous or correlated spectral cues were available over a wider bandwidth for those syllables from the middle of the continuum for which the neural representation was least variable. C1 LOS ALAMOS NATL LAB,LOS ALAMOS,NM 87545. OI Sinex, Donal/0000-0002-0673-7252 FU NIDCD NIH HHS [DC00341] NR 54 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 0001-4966 J9 J ACOUST SOC AM JI J. Acoust. Soc. Am. PD NOV PY 1991 VL 90 IS 5 BP 2441 EP 2449 DI 10.1121/1.402048 PG 9 WC Acoustics; Audiology & Speech-Language Pathology SC Acoustics; Audiology & Speech-Language Pathology GA GN734 UT WOS:A1991GN73400006 PM 1774413 ER PT J AU HODGSON, AT DAISEY, JM GROT, RA AF HODGSON, AT DAISEY, JM GROT, RA TI SOURCES AND SOURCE STRENGTHS OF VOLATILE ORGANIC-COMPOUNDS IN A NEW OFFICE BUILDING SO JOURNAL OF THE AIR & WASTE MANAGEMENT ASSOCIATION LA English DT Article ID EXPOSURE AB This study was conducted at a newly constructed federal office building in Portland, Oregon. The primary objectives were to identity the major sources of volatile organic compounds (VOC) in the building and to measure both long-term (one year) and short-term (several day) variations in concentrations and source strengths. Samples for VOC were collected on four occasions over a period of 14 months starting with the first month of occupancy. During the final sampling period, samples were collected over four days (Friday - Monday). The samples were analyzed for individual compounds and for total VOC (TVOC). The results were expressed as specific source strengths, as well as concentrations, to facilitate comparisons of measurements made under different ventilation conditions. The primary source of VOC in the building was identified as liquid-process photocopiers and plotters which emitted a characteristic mixture of C-10-C-11 isoparaffinic hydrocarbons. The specific source strength of TVOC, which was dominated by the emissions from these office machines, remained relatively constant over the course of the study. Motor vehicles in the below-ground parking garage were implicated as another major source of hydrocarbons in the building. Over the final four-day sampling period, the specific source strength of TVOC varied by about a factor of five, predominantly reflecting occupant use of office machines. C1 NATL INST STAMP & TECHNOL,DIV BLDG ENVIRONMENT,CTR BLDG TECHNOL,GAITHERSBURG,MD 20899. RP HODGSON, AT (reprint author), UNIV CALIF BERKELEY,LAWRENCE BERKELEY LAB,DIV APPL SCI,INDOOR ENVIRONM PROGRAM,BERKELEY,CA 94720, USA. NR 13 TC 29 Z9 29 U1 0 U2 3 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 NOV PY 1991 VL 41 IS 11 BP 1461 EP 1468 PG 8 WC Engineering, Environmental; Environmental Sciences; Meteorology & Atmospheric Sciences SC Engineering; Environmental Sciences & Ecology; Meteorology & Atmospheric Sciences GA GR444 UT WOS:A1991GR44400009 ER PT J AU REDDY, TA GADSBY, KJ BLACK, HE HARRJE, DT SEXTRO, RG AF REDDY, TA GADSBY, KJ BLACK, HE HARRJE, DT SEXTRO, RG TI MODELING AIR-FLOW DYNAMICS IN RADON MITIGATION SYSTEMS - A SIMPLIFIED APPROACH SO JOURNAL OF THE AIR & WASTE MANAGEMENT ASSOCIATION LA English DT Article AB Subslab air flow dynamics provide important diagnostic information for designing optimal radon mitigation systems based on the subslab depressurization technique. In this paper, it is suggested that subslab air flow induced by a central suction point be treated as radial air flow through a porous bed contained between two impermeable disks. Next, we show that subslab air flow is most likely to be turbulent under actual field situations in houses with subslab gravel beds, while remaining laminar when saul is present under the slab. The physical significance of this model is discussed and simplified closed-form equations are derived to predict pressure and flows at various distances from a single central depressurization point. A laboratory apparatus was built in order to verify our model and experimentally determine the model coefficients of the pressure drop versus flow for commonly encountered subslab gravel materials. These pressure drop coefficients can be used in conjunction with our simplified model as a rational means of assessing subslab connectivity in actual houses, which is an important aspect of the pre-mitigation diagnostic phase. Preliminary field verification results in a house with gravel under the basement slab are presented and discussed. C1 PRINCETON UNIV,SCH ENGN APPL SCI,CTR ENERGY & ENVIRONM STUDIES,PRINCETON,NJ 08544. UNIV CALIF BERKELEY,LAWRENCE BERKELEY LAB,INDOOR ENVIRONM PROGRAM,BERKELEY,CA 94720. NR 11 TC 3 Z9 3 U1 0 U2 1 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 NOV PY 1991 VL 41 IS 11 BP 1476 EP 1482 PG 7 WC Engineering, Environmental; Environmental Sciences; Meteorology & Atmospheric Sciences SC Engineering; Environmental Sciences & Ecology; Meteorology & Atmospheric Sciences GA GR444 UT WOS:A1991GR44400011 ER PT J AU NOLAN, TA ALLARD, LF COFFEY, DW HUBBARD, CR PADGETT, RA RAWLINS, MH NIXDORF, RW AF NOLAN, TA ALLARD, LF COFFEY, DW HUBBARD, CR PADGETT, RA RAWLINS, MH NIXDORF, RW TI MICROSTRUCTURE AND CRYSTALLOGRAPHY OF TITANIUM NITRIDE WHISKERS GROWN BY A VAPOR-LIQUID-SOLID PROCESS SO JOURNAL OF THE AMERICAN CERAMIC SOCIETY LA English DT Article AB Titanium nitride whiskers having diameters of 0.5 to 1.5-mu-m and aspect ratios in the range of 20 to 50 have been produced by a new commercially scalable vapor-liquid-solid process. Electron microscopy studies have shown that most of the whiskers can be classified into two types based upon structure and morphology. The whiskers of one type are single crystals and have a growth direction of <100>. Whiskers of the second type are comprised of two crystals having a common <110> growth direction. Both types have smooth surfaces and relatively few internal defects. Additionally, a small percentage of whiskers have considerable internal structure related to significnat magnesium impurities. C1 REMAXCO TECHNOL INC,KNOXVILLE,TN 37922. RP NOLAN, TA (reprint author), OAK RIDGE NATL LAB,HIGH TEMP MAT LAB,OAK RIDGE,TN 37831, USA. NR 17 TC 3 Z9 3 U1 1 U2 3 PU AMER CERAMIC SOC PI WESTERVILLE PA 735 CERAMIC PLACE, PO BOX 6136, WESTERVILLE, OH 43081-6136 SN 0002-7820 J9 J AM CERAM SOC JI J. Am. Ceram. Soc. PD NOV PY 1991 VL 74 IS 11 BP 2769 EP 2775 DI 10.1111/j.1151-2916.1991.tb06841.x PG 7 WC Materials Science, Ceramics SC Materials Science GA GQ453 UT WOS:A1991GQ45300006 ER PT J AU HAN, Y AKINC, M AF HAN, Y AKINC, M TI PREPARATION OF CALCIUM LANTHANUM SULFIDE POWDERS VIA ALKOXIDE SULFURIZATION SO JOURNAL OF THE AMERICAN CERAMIC SOCIETY LA English DT Article ID CALA2S4 AB Calcium lanthanum sulfide powders were prepared by reacting methoxides of calcium and lanthanum with H2S. Alkoxide mixtures of various La/Ca ratios dispersed in methanol were reacted with H2S at 25-degrees to 85-degrees-C and the amorphous gels obtained after the removal of methanol were heat-treated in H2S for full sulfurization at various temperatures. Up to 500-degrees-C, cubic LaS2 was the only crystalline phase present. Calcium lanthanum sulfide phase started to form at 550-degrees-C. In the temperature range of 650-degrees to 750-degrees-C, single-phase calcium lanthanum sulfide powders were obtained for La/Ca = 2.41 and 2.68. C1 IOWA STATE UNIV SCI & TECHNOL,AMES LAB,AMES,IA 50011. RP HAN, Y (reprint author), IOWA STATE UNIV SCI & TECHNOL,DEPT MAT SCI & ENGN,AMES,IA 50011, USA. NR 29 TC 24 Z9 24 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 NOV PY 1991 VL 74 IS 11 BP 2815 EP 2819 DI 10.1111/j.1151-2916.1991.tb06848.x PG 5 WC Materials Science, Ceramics SC Materials Science GA GQ453 UT WOS:A1991GQ45300013 ER PT J AU CHU, MY DEJONGHE, LC LIN, MKF LIN, FJT AF CHU, MY DEJONGHE, LC LIN, MKF LIN, FJT TI PRECOARSENING TO IMPROVE MICROSTRUCTURE AND SINTERING OF POWDER COMPACTS SO JOURNAL OF THE AMERICAN CERAMIC SOCIETY LA English DT Article ID STABILITY; KINETICS; ARRAYS AB MgO and Al2O3 were sintered by two types of processes: a conventional isothermal sintering and a two-step sintering consisting of an initial low-temperature precoarsening treatment before conventional isothermal sintering. The final microstructure from two-step sintering can be more uniform and finer than that of compacts sintered conventionally. A narrow-size-distribution alumina powder was sintered under constant-heating-rate conditions, with and without a precoarsening treatment, and the results were compared. The differences between two-step and conventional processing were clarified by experiments on precoarsened and as-received ZnO powders. These compacts were precoarsened at 450-degrees-C for 90 h with virtually no increase in the overall density. The resulting grain size was 1.7 times the starting one, but the standard deviation of the precoarsened powder size distribution was smaller than that of the as-received powder. Precoarsened compacts sintered to nearly full density showed improved homogeneity. The sintering stress of the precoarsened ZnO was approximately 0.8 that of the as-received one. A computational model has been used with two components of coarsening to describe the differences in pore spacing evolution between the precoarsened and the as-received system. The benefit of two-step sintering is attributed to the increase in uniformity resulting from precoarsening. The increased uniformity decreases sintering damage and allows the system to stay in the open porosity state longer, delaying or inhibiting additional coarsening (grain growth) during the final stage of densification. Two-step sintering is especially useful for nonuniform powder systems with a wide size distribution and is a simple and convenient method of making more uniform ceramic bodies without resorting to specialized powders or complicated heat schedules. C1 UNIV CALIF BERKELEY,LAWRENCE BERKELEY LAB,DIV MAT SCI,BERKELEY,CA 94720. UNIV CALIF BERKELEY,DEPT MAT SCI & MINERAL ENGN,BERKELEY,CA 94720. NR 22 TC 41 Z9 43 U1 1 U2 8 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 NOV PY 1991 VL 74 IS 11 BP 2902 EP 2911 DI 10.1111/j.1151-2916.1991.tb06861.x PG 10 WC Materials Science, Ceramics SC Materials Science GA GQ453 UT WOS:A1991GQ45300026 ER PT J AU BAKAC, A ESPENSON, JH AF BAKAC, A ESPENSON, JH TI KINETICS OF THE CAPTURE OF METHYL RADICALS BY CARBON-MONOXIDE IN AQUEOUS-SOLUTION SO JOURNAL OF THE CHEMICAL SOCIETY-CHEMICAL COMMUNICATIONS LA English DT Article ID RATE CONSTANTS; COMPLEXES; ALKYL AB The title reaction has a rate constant of (2.0 +/- 0.3) x 10(6) dm3 mol-1 s-1 at 25-degrees-C, which is fast enough to make it a useful route for C-C bond formation even at ambient temperatures and pressures. C1 IOWA STATE UNIV SCI & TECHNOL,DEPT CHEM,AMES,IA 50011. RP BAKAC, A (reprint author), IOWA STATE UNIV SCI & TECHNOL,AMES LAB,AMES,IA 50011, USA. NR 9 TC 17 Z9 17 U1 0 U2 0 PU ROYAL SOC CHEMISTRY PI CAMBRIDGE PA THOMAS GRAHAM HOUSE, SCIENCE PARK MILTON ROAD, CAMBRIDGE, CAMBS, ENGLAND CB4 4WF SN 0022-4936 J9 J CHEM SOC CHEM COMM JI J. Chem. Soc.-Chem. Commun. PD NOV 1 PY 1991 IS 21 BP 1497 EP 1498 DI 10.1039/c39910001497 PG 2 WC Chemistry, Multidisciplinary SC Chemistry GA GP557 UT WOS:A1991GP55700001 ER PT J AU GOTTESFELD, S MAIA, G FLORIANO, JB TREMILIOSI, G TICIANELLI, EA GONZALEZ, ER AF GOTTESFELD, S MAIA, G FLORIANO, JB TREMILIOSI, G TICIANELLI, EA GONZALEZ, ER TI STUDY OF THICK ANODIC OXIDE-FILMS ON PT BY SPECTROSCOPIC ELLIPSOMETRY SO JOURNAL OF THE ELECTROCHEMICAL SOCIETY LA English DT Article ID PLATINUM; RESOLUTION; SURFACES AB We describe a study of the oxide films grown on a platinum (Pt) electrode by anodization at 2.1 V in a 0.5 M H2SO4 solution. These oxide films were studied before by single lambda ellipsometry (1) and by cyclic voltammetry (2). Our present study employed a spectroscopic ellipsometer, and thus allowed us to measure in situ the spectrum of the anodic oxide film in the wavelength range 300 to 800 nm, at various stages of film growth. We show that both film thickness and optical spectrum can be solved at each stage in oxide growth by assuming a highly absorbing thin film (congruent-to 30 angstrom) adjacent to the metal surface, and, on top of it, a second film, which is most probably a hydrous form of PtO2. The latter film reaches thicknesses of several hundred angstrom after more than two days of anodization. The thick film seems to grow at a constant rate, unaffected by its thickness. The optical spectrum of the latter film shows a nonzero extinction coefficient, k(f), in the visible, which tends to increase toward the near-UV end of the lambda-domain probed, suggesting a bandgap > 3.5 eV. A typical range for the value of triple overdot n(film) of the thicker external oxide layer is triple overdot n = (1.70 +/- 0.03) - (0.15 +/- 0.05)i. C1 UNIV CALIF LOS ALAMOS SCI LAB,LOS ALAMOS,NM 87545. RP GOTTESFELD, S (reprint author), UNIV SAO PAULO,INST FIS & QUIM,BR-13560 SAO CARLOS,SP,BRAZIL. RI Maia, Gilberto/A-8051-2012; Ticianelli, Edson/D-1560-2012; Gonzalez, Ernesto /C-9422-2012; Tremiliosi-Filho, Germano/D-6684-2012 OI Maia, Gilberto/0000-0003-2449-0887; Ticianelli, Edson/0000-0003-3432-2799; NR 19 TC 25 Z9 25 U1 3 U2 8 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 NOV PY 1991 VL 138 IS 11 BP 3219 EP 3224 DI 10.1149/1.2085395 PG 6 WC Electrochemistry; Materials Science, Coatings & Films SC Electrochemistry; Materials Science GA GN909 UT WOS:A1991GN90900014 ER PT J AU GIBBONS, DW MULLER, RH TOBIAS, CW AF GIBBONS, DW MULLER, RH TOBIAS, CW TI MASS-TRANSPORT TO CYLINDRICAL ELECTRODES ROTATING IN SUSPENSIONS OF INERT MICROSPHERES SO JOURNAL OF THE ELECTROCHEMICAL SOCIETY LA English DT Article ID EFFECTIVE THERMAL-CONDUCTIVITY; DISK ELECTRODE; SUSPENDED PARTICLES; CYLINDER ELECTRODE; DEPOSITION; KINETICS; SPHERES; SOLIDS; BATHS AB Mass transfer enhancement produced by the addition of inert microspheres was investigated on a rotating cylinder electrode operating in the turbulent regime. The effects of rotation speed, rotor radius, particle size, solids volume fraction, and particle density on the rate of mass transfer were determined by limiting current measurements for ferricyanide ion reduction. In comparison to transport rates observed with clear electrolytes, up to two and a half fold higher limiting currents were obtained in concentrated suspensions containing 5-80-mu-m diameter microspheres with densities ranging from 0.7 to 2.1 g/cm3. Transport enhancement is attributed to the microconvective eddies produced by particle rotation in the shear field adjacent to the spinning electrode, and to the increased shear rate caused by the formation of a particle-free wall layer. Experimental data could be correlated in the form Sh = alpha-Re-beta-Sc1/3 where Sh, Re, and Sc are the Sherwood, Reynolds, and Schmidt numbers, respectively, and alpha and beta are empirical functions of solids volume fraction determined from transport rate measurements. The addition of appreciable volume fractions of inert particles to the electrolyte results in significant improvements in production capacity when the latter is limited by transport rates. The use of suspended particles to achieve a given increase in limiting current density is shown to require much less power than simply increasing electrode rotation speed to enhance mass transport. C1 UNIV CALIF BERKELEY,LAWRENCE BERKELEY LAB,DEPT CHEM ENGN,BERKELEY,CA 94720. UNIV CALIF BERKELEY,LAWRENCE BERKELEY LAB,DIV CHEM SCI,BERKELEY,CA 94720. ELTECH RES CORP,FAIRPORT HARBOR,OH 44077. NR 49 TC 9 Z9 9 U1 0 U2 0 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 NOV PY 1991 VL 138 IS 11 BP 3255 EP 3264 DI 10.1149/1.2085400 PG 10 WC Electrochemistry; Materials Science, Coatings & Films SC Electrochemistry; Materials Science GA GN909 UT WOS:A1991GN90900019 ER PT J AU FENG, JR JOHNSON, DC AF FENG, JR JOHNSON, DC TI ELECTROCATALYSIS OF ANODIC OXYGEN-TRANSFER REACTIONS - TITANIUM SUBSTRATES FOR PURE AND DOPED LEAD DIOXIDE FILMS SO JOURNAL OF THE ELECTROCHEMICAL SOCIETY LA English DT Article ID ACIDIC MEDIA; ELECTRODES AB Voltammetric and kinetic results are described for the electrocatalytic oxidations of various compounds at doped PbO2- film electrodes on Ti substrates. Compounds tested include dimethyl sulfoxide and several thiophene derivatives. Results are emphasized for PbO2 films doped with Fe(III) (Fe-PbO2), and with Ag(I) and Bi(V) (Ag-Bi-PbO2), that were electrolytically deposited on Ti substrates with the presence of an interlayer of PbO2 deposited from acidic solutions of Pb2+ and NaF. These "laminar" film electrodes are quite stable and offer significantly improved catalytic activity for various anodic oxygen-transfer reactions in comparison to pure PbO2-film electrodes. C1 IOWA STATE UNIV SCI & TECHNOL,AMES LAB,AMES,IA 50011. RP FENG, JR (reprint author), IOWA STATE UNIV SCI & TECHNOL,DEPT CHEM,AMES,IA 50011, USA. NR 25 TC 80 Z9 93 U1 0 U2 4 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 NOV PY 1991 VL 138 IS 11 BP 3328 EP 3337 DI 10.1149/1.2085410 PG 10 WC Electrochemistry; Materials Science, Coatings & Films SC Electrochemistry; Materials Science GA GN909 UT WOS:A1991GN90900029 ER PT J AU PATTERSON, FG PERRY, MD AF PATTERSON, FG PERRY, MD TI DESIGN AND PERFORMANCE OF A MULTITERAWATT, SUBPICOSECOND NEODYMIUM - GLASS-LASER SO JOURNAL OF THE OPTICAL SOCIETY OF AMERICA B-OPTICAL PHYSICS LA English DT Article ID STIMULATED RAMAN-SCATTERING; CHIRPED-PULSE AMPLIFICATION; GROUP-VELOCITY DISPERSION; GRATING COMPRESSOR; OPTICAL PULSES; RARE-GASES; SYSTEM; IONIZATION; ND; SPECTROSCOPY AB A tabletop Nd:phosphate glass laser system capable of producing subpicosecond pulses with a peak power > 8.5 TW is described. Relay imaging and optimization of the chirped-pulse amplification technique, including spectral shaping and careful attention to beam quality, produce a transform-limited, 800-fs compressed pulse with an energy of 6.8 J 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 37 TC 52 Z9 52 U1 0 U2 5 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 NOV PY 1991 VL 8 IS 11 BP 2384 EP 2391 DI 10.1364/JOSAB.8.002384 PG 8 WC Optics SC Optics GA GN918 UT WOS:A1991GN91800021 ER PT J AU CREIGHTON, JR AF CREIGHTON, JR TI TRIMETHYLGALLIUM DISSOCIATIVE CHEMISORPTION ON GALLIUM-RICH GAAS(100) SURFACES SO JOURNAL OF VACUUM SCIENCE & TECHNOLOGY A-VACUUM SURFACES AND FILMS LA English DT Article ID ATOMIC LAYER EPITAXY; THERMAL-DECOMPOSITION; GAAS; GROWTH; DEPOSITION; ADSORPTION; KINETICS; RATES; SIMS; LEED AB Trimethylgallium (TMGa) chemisorption on the gallium-rich "(4 x 6)" and (1 x 6) GaAs(100) surfaces has been studied with temperature programmed desorption (TPD) and static secondary ion mass spectroscopy (SSIMS). Low coverages of TMGa irreversibly dissociate on GaAs(100) and methyl radicals are the main gas-phase product observed around 700 K during TPD. At higher TMGa coverages some recombinative desorption of molecular TMGa occurs from 250-650 K. On the Ga-rich surface reconstructions the desorbing methyl radicals are kinetically indistinguishable, strongly suggesting that they evolve from a single type of binding site. We believe this binding site corresponds to surface MMGa, which is formed by stepwise methyl group transfer from chemisorbed TMGa to neighboring surface gallium atoms. The presence of MMGa is supported by SSIMS results at approximately 650 K. Temperature-programmed SSIMS was used to follow the dissociation of adsorbed TMGa from 120 to 700 K. RP CREIGHTON, JR (reprint author), SANDIA NATL LABS,ALBUQUERQUE,NM 87185, USA. NR 42 TC 23 Z9 23 U1 0 U2 3 PU AMER INST PHYSICS PI WOODBURY PA CIRCULATION FULFILLMENT DIV, 500 SUNNYSIDE BLVD, WOODBURY, NY 11797-2999 SN 0734-2101 J9 J VAC SCI TECHNOL A JI J. Vac. Sci. Technol. A-Vac. Surf. Films PD NOV-DEC PY 1991 VL 9 IS 6 BP 2895 EP 2899 DI 10.1116/1.577148 PG 5 WC Materials Science, Coatings & Films; Physics, Applied SC Materials Science; Physics GA GP815 UT WOS:A1991GP81500005 ER PT J AU GALUSKA, AA AF GALUSKA, AA TI NI QUARTZ ADHESION ENHANCEMENT - COMPARISON OF AR+ AND SI+ ION MIXING SO JOURNAL OF VACUUM SCIENCE & TECHNOLOGY A-VACUUM SURFACES AND FILMS LA English DT Article ID SI-28+ IMPLANTATION; FILMS; CARBON; ESCA AB The adhesion between 30 nm Ni films and quartz substrates was examined as a function of the interfacial chemistry and mixing induced by low temperature (< 100-degrees-C) Ar-40+ and Si-28+ ion mixing. The Ni/quartz specimens were implanted with either 65 keV Ar-40+ or 55 keV Si-28+ to doses between 1 and 10 x 10(16) atom/cm2. Both types of implants were observed to induce extensive interfacial grading. X-ray photoelectron spectroscopy analyses indicated that Ni-O-Si types of interfacial complexes were present in the as-deposited specimens, but that these complexes were eliminated by the Ar-40+ ion mixing. In contrast, high dose Si-28+ ion mixing was shown to induce the formation of new interfacial complexes (Ni-Si-O and new Ni-O-Si complexes). Adhesion measurements, performed using a scratch tester, indicated that the adhesion of the as-deposited specimens was good (20 N), but that this adhesion got progressively worse (to less than 1 N) with Ar-40+ implantation. In the case of Si-28+ ion mixing, adhesion was reduced (to 5 N) in the low dose specimens, but was substantially increased (to 45 N) in the high dose specimens. Overall, Ni/quartz adhesion was shown to correlate with the concentration of interfacial complexes that could chemically attach the Ni films and quartz substrates. RP GALUSKA, AA (reprint author), SANDIA NATL LABS,ALBUQUERQUE,NM 87185, USA. NR 14 TC 5 Z9 5 U1 0 U2 0 PU AMER INST PHYSICS PI WOODBURY PA CIRCULATION FULFILLMENT DIV, 500 SUNNYSIDE BLVD, WOODBURY, NY 11797-2999 SN 0734-2101 J9 J VAC SCI TECHNOL A JI J. Vac. Sci. Technol. A-Vac. Surf. Films PD NOV-DEC PY 1991 VL 9 IS 6 BP 2907 EP 2915 DI 10.1116/1.577150 PG 9 WC Materials Science, Coatings & Films; Physics, Applied SC Materials Science; Physics GA GP815 UT WOS:A1991GP81500007 ER PT J AU KLEM, JF TSAO, JY RENO, JL DATYE, A CHADDA, S AF KLEM, JF TSAO, JY RENO, JL DATYE, A CHADDA, S TI THERMAL-DESORPTION OF INSB SURFACE OXIDES SO JOURNAL OF VACUUM SCIENCE & TECHNOLOGY A-VACUUM SURFACES AND FILMS LA English DT Article ID MOLECULAR-BEAM EPITAXY; INSB(100); GROWTH AB We have investigated methods of chemical preparation and thermal treatments of InSb substrates to produce InSb surfaces suitable for subsequent molecular beam epitaxy. Etching in a solution of lactic acid: HNO3:HCl was shown to produce an oxide surface layer which could be thermally desorbed. Growth on surfaces prepared in this manner produced precipitate-free substrate-epilayer interfaces. C1 UNIV NEW MEXICO,DEPT CHEM & NUCL ENGN,ALBUQUERQUE,NM 87131. RP KLEM, JF (reprint author), SANDIA NATL LABS,ALBUQUERQUE,NM 87185, USA. NR 8 TC 20 Z9 21 U1 1 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 NOV-DEC PY 1991 VL 9 IS 6 BP 2996 EP 2998 DI 10.1116/1.577162 PG 3 WC Materials Science, Coatings & Films; Physics, Applied SC Materials Science; Physics GA GP815 UT WOS:A1991GP81500019 ER PT J AU BASFORD, JA AF BASFORD, JA TI LEAK CALIBRATION BY THE DELTA-P-DELTA V AND PRESSURE DIFFERENCE TECHNIQUES SO JOURNAL OF VACUUM SCIENCE & TECHNOLOGY A-VACUUM SURFACES AND FILMS LA English DT Article AB Two techniques for calibrating leaks, one primary and one secondary, are described. The DELTA-P-DELTA-V method, a primary technique, is a modification of the P-DELTA-V technique which requires less time, has smaller outgassing error, and allows simultaneous, automated calibrations of several leaks in the range 10(-8)-10(-12) mol s-1. The pressure difference method is a comparison technique in which a mass spectrometer is used to compare the partial pressure of gas collected from the leak being calibrated to a known partial pressure generated by a constant flow. It is useful for calibrations in the 10(-12)-10(-15) mol s-1 range. Both methods have been incorporated in an automated apparatus. RP BASFORD, JA (reprint author), MARTIN MARIETTA ENERGY SYST INC,OAK RIDGE Y-12 PLANT,OAK RIDGE,TN 37831, USA. NR 8 TC 3 Z9 3 U1 0 U2 1 PU AMER INST PHYSICS PI WOODBURY PA CIRCULATION FULFILLMENT DIV, 500 SUNNYSIDE BLVD, WOODBURY, NY 11797-2999 SN 0734-2101 J9 J VAC SCI TECHNOL A JI J. Vac. Sci. Technol. A-Vac. Surf. Films PD NOV-DEC PY 1991 VL 9 IS 6 BP 3153 EP 3158 DI 10.1116/1.577187 PG 6 WC Materials Science, Coatings & Films; Physics, Applied SC Materials Science; Physics GA GP815 UT WOS:A1991GP81500044 ER PT J AU CARLSSON, JO GORBATKIN, S LUBBEN, D GREENE, JE AF CARLSSON, JO GORBATKIN, S LUBBEN, D GREENE, JE TI THERMODYNAMICS OF THE HOMOGENEOUS AND HETEROGENEOUS DECOMPOSITION OF TRIMETHYLALUMINUM, MONOMETHYLALUMINUM, AND DIMETHYLALUMINUMHYDRIDE - EFFECTS OF SCAVENGERS AND ULTRAVIOLET-LASER PHOTOLYSIS SO JOURNAL OF VACUUM SCIENCE & TECHNOLOGY B LA English DT Article ID ALUMINUM; DEPOSITION; GROWTH; FILM; GAAS; GAS AB Thermodynamic calculations, based upon free-energy minimization, have been used to determine the nature and the relative amounts of equilibrium product species following thermal decomposition of the Al-bearing metal-alkyl donor molecules trimethylaluminum Al(CH3)3, monomethylaluminum AlCH3, and dimethylaluminumhydride Al(CH3)2H at temperatures between 0 and 1250-degrees-C. The calculations were carried out using initial total pressures of 760, 1, and 0.1 Torr (101 kPa, 133, and 13.3 Pa) and both homogeneous and heterogeneous decomposition were considered. The calculations were repeated for mixtures containing trimethylaluminum and the reducing agents H-2, arsine AsH3, and silane SiH4 in order to investigate the effectiveness of these species in scavenging C-containing radicals. The effect of H-2 on the decomposition of AlCH3 and Al(CH3)2H was also studied. The results are discussed and compared with available data from Al film growth experiments by pyrolytic chemical vapor deposition (CVD) and laser-induced photolytic CVD. Finally, the CVD phase diagram for solid product species was computed for reactant mixtures of Al2(CH3)6 + AsH3 + H-2. C1 UNIV ILLINOIS,COORDINATED SCI LAB,DEPT MAT SCI,URBANA,IL 61801. UNIV ILLINOIS,DEPT MAT SCI,MAT RES LAB,URBANA,IL 61801. OAK RIDGE NATL LAB,OAK RIDGE,TN 37831. NR 32 TC 11 Z9 11 U1 1 U2 6 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 NOV-DEC PY 1991 VL 9 IS 6 BP 2759 EP 2770 DI 10.1116/1.585642 PG 12 WC Engineering, Electrical & Electronic; Nanoscience & Nanotechnology; Physics, Applied SC Engineering; Science & Technology - Other Topics; Physics GA GW423 UT WOS:A1991GW42300006 ER PT J AU SMITH, HI HECTOR, SD SCHATTENBURG, ML ANDERSON, EH AF SMITH, HI HECTOR, SD SCHATTENBURG, ML ANDERSON, EH TI A NEW APPROACH TO HIGH FIDELITY E-BEAM AND ION-BEAM LITHOGRAPHY BASED ON AN INSITU GLOBAL-FIDUCIAL GRID SO JOURNAL OF VACUUM SCIENCE & TECHNOLOGY B LA English DT Article; Proceedings Paper CT 35TH INTERNATIONAL SYMP ON ELECTRON, ION, AND PHOTON BEAMS CY MAY 28-31, 1991 CL SEATTLE, WA SP AMER VACUUM SOC, IEEE, ELECTR DEVICE, OPT SOC AMER ID X-RAY-LITHOGRAPHY; ULTRAVIOLET AB The distortion-free scan field of an electron-beam or ion-beam lithography system is generally quite small (approximately 10(4) x 10(4) beam addresses) and hence to achieve pattern fidelity over large areas laser-interferometer-controlled stages are employed. Because the laser interferometer monitors the stage, not the electron or ion beam, beam drift of thermal, mechanical, electrostatic, magnetic, or electronic origin is not accounted for, leading to pattern placement error. To overcome this fundamental problem of "dead reckoning" we propose a new approach in which a global-fiducial reference grid, which does not disturb the writing process, is put directly on the substrate. The grid is scanned with sufficiently low areal dose that the subsequent pattern development is not adversely affected. This can be achieved by "sparse sampling" of the grid over the entire scan field in conjunction with phase-locking technqiues in the time domain. In this way one can spatially phase lock the two grids together and thereby ensure pattern placement accuracy. The pattern of interest is then written within the scan field. This method assumes that no drift occurs during the writing of the single field. However, it may also be feasible to do some drift monitoring during the field writing. We consider secondary electrons to be the optimal signal for "seeing" the grid. In addition to providing enhanced pattern integrity (and hence better overlay in 1-to-1 masks), lithography systems based on an in situ global-fiducial grid may prove to be of lower cost than conventional systems since the difficult task of ensuring pattern integrity is thrust upon a computer rather than an advanced electromechanical system. C1 MIT,CTR SPACE RES,CAMBRIDGE,MA 02139. UNIV CALIF BERKELEY,LAWRENCE BERKELEY LAB,BERKELEY,CA 94720. RP SMITH, HI (reprint author), MIT,DEPT ELECT ENGN & COMP SCI,CAMBRIDGE,MA 02139, USA. NR 9 TC 38 Z9 38 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 NOV-DEC PY 1991 VL 9 IS 6 BP 2992 EP 2995 DI 10.1116/1.585355 PG 4 WC Engineering, Electrical & Electronic; Nanoscience & Nanotechnology; Physics, Applied SC Engineering; Science & Technology - Other Topics; Physics GA GW423 UT WOS:A1991GW42300050 ER PT J AU TENNANT, DM BJORKHOLM, JE DSOUZA, RM EICHNER, L FREEMAN, RR PASTALAN, JZ SZETO, LH WOOD, OR JEWELL, TE MANSFIELD, WM WASKIEWICZ, WK WHITE, DL WINDT, DL MACDOWELL, AA AF TENNANT, DM BJORKHOLM, JE DSOUZA, RM EICHNER, L FREEMAN, RR PASTALAN, JZ SZETO, LH WOOD, OR JEWELL, TE MANSFIELD, WM WASKIEWICZ, WK WHITE, DL WINDT, DL MACDOWELL, AA TI REFLECTIVE MASK TECHNOLOGIES AND IMAGING RESULTS IN SOFT-X-RAY PROJECTION LITHOGRAPHY SO JOURNAL OF VACUUM SCIENCE & TECHNOLOGY B LA English DT Article; Proceedings Paper CT 35TH INTERNATIONAL SYMP ON ELECTRON, ION, AND PHOTON BEAMS CY MAY 28-31, 1991 CL SEATTLE, WA SP AMER VACUUM SOC, IEEE, ELECTR DEVICE, OPT SOC AMER ID REDUCTION; FEATURES; METAL AB In this work we investigate and compare a variety of technologies for patterning high resolution Mo/Si multilayer reflective x-ray masks for use at wavelengths near 13 nm. The patterning methods investigated include: absorbing layers deposited on top of multilayer reflectors, reflective coating removal by reactive ion etching and ion damage of multilayer regions to form a planar mask structure. Large area samples were prepared by each of the above methods and reflectivity measurements made to determine the expected mask contrast. The reflectivity data are compared with simulation for the absorber overlayer and etched multilayer measurements. Our results indicate that reflectivity changes between 5 and 300 were effected. Fine patterning tests show that mask features as fine as 0.1-mu-m can be achieved in each technology. The advantages, process complexity, and limits of each method are discussed. We also report the first use of an x-ray reflectance mask to print 0.1-mu-m features in resist. The developed resist images obtained using reflection masks in a 20:1 Schwarzschild projection camera compare favorably with transmission mask results obtained using the same optical system. C1 AT&T BELL LABS,MURRAY HILL,NJ 07974. BROOKHAVEN NATL LAB,UPTON,NY 11973. RP TENNANT, DM (reprint author), AT&T BELL LABS,HOLMDEL,NJ 07733, USA. NR 12 TC 22 Z9 22 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 NOV-DEC PY 1991 VL 9 IS 6 BP 3176 EP 3183 DI 10.1116/1.585312 PG 8 WC Engineering, Electrical & Electronic; Nanoscience & Nanotechnology; Physics, Applied SC Engineering; Science & Technology - Other Topics; Physics GA GW423 UT WOS:A1991GW42300087 ER PT J AU KUBIAK, GD TICHENOR, DA MALINOWSKI, ME STULEN, RH HANEY, SJ BERGER, KW BROWN, LA BJORKHOLM, JE FREEMAN, RR MANSFIELD, WM TENNANT, DM WOOD, OR BOKOR, J JEWELL, TE WHITE, DL WINDT, DL WASKIEWICZ, WK AF KUBIAK, GD TICHENOR, DA MALINOWSKI, ME STULEN, RH HANEY, SJ BERGER, KW BROWN, LA BJORKHOLM, JE FREEMAN, RR MANSFIELD, WM TENNANT, DM WOOD, OR BOKOR, J JEWELL, TE WHITE, DL WINDT, DL WASKIEWICZ, WK TI DIFFRACTION-LIMITED SOFT-X-RAY PROJECTION LITHOGRAPHY WITH A LASER PLASMA SOURCE SO JOURNAL OF VACUUM SCIENCE & TECHNOLOGY B LA English DT Article; Proceedings Paper CT 35TH INTERNATIONAL SYMP ON ELECTRON, ION, AND PHOTON BEAMS CY MAY 28-31, 1991 CL SEATTLE, WA SP AMER VACUUM SOC, IEEE, ELECTR DEVICE, OPT SOC AMER ID REDUCTION AB A laser plasma source of extreme ultraviolet and soft x-ray radiation has been used to print diffraction-limited features using soft x-ray projection lithography. A spherical condenser optic, a Si/Ge transmissive mask and a Mo/Si multilayer-coated Schwarzschild objective having 20:1 reduction ratio were employed to pattern selected single-layer and trilevel resists. At a numerical aperture of 0.12, a 0.1-mu-m line and space pattern is clearly delineated and weak modulation is observed for the analogous 0.05-mu-m pattern. C1 AT&T BELL LABS,HOLMDEL,NJ 07733. AT&T BELL LABS,MURRAY HILL,NJ 07974. RP KUBIAK, GD (reprint author), SANDIA NATL LABS,POB 969,LIVERMORE,CA 94551, USA. RI Bokor, Jeffrey/A-2683-2011 NR 23 TC 19 Z9 19 U1 0 U2 2 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 NOV-DEC PY 1991 VL 9 IS 6 BP 3184 EP 3188 DI 10.1116/1.585313 PG 5 WC Engineering, Electrical & Electronic; Nanoscience & Nanotechnology; Physics, Applied SC Engineering; Science & Technology - Other Topics; Physics GA GW423 UT WOS:A1991GW42300088 ER PT J AU ADESIDA, I BALLEGEER, DG SEO, JW KETTERSON, A CHANG, H CHENG, KY GESSERT, T AF ADESIDA, I BALLEGEER, DG SEO, JW KETTERSON, A CHANG, H CHENG, KY GESSERT, T TI ETCHING OF INDIUM TIN OXIDE IN METHANE/HYDROGEN PLASMAS SO JOURNAL OF VACUUM SCIENCE & TECHNOLOGY B LA English DT Article; Proceedings Paper CT 35TH INTERNATIONAL SYMP ON ELECTRON, ION, AND PHOTON BEAMS CY MAY 28-31, 1991 CL SEATTLE, WA SP AMER VACUUM SOC, IEEE, ELECTR DEVICE, OPT SOC AMER ID DEPOSITION; DISCHARGE AB The reactive ion etching of the transparent conductor, indium tin oxide (ITO), in methane/hydrogen plasmas has been characterized. It is shown that ITO can be selectively etched on GaAs and AlGaAs. Anisotropic structures and gratings with submicrometer dimensions in ITO are presented. Application of the etching process to the fabrication of highly sensitive metal-semiconductor-metal (MSM) photodetectors with interdigitated ITO fingers is demonstrated. C1 UNIV ILLINOIS,DEPT ELECT & COMP ENGN,URBANA,IL 61801. SOLAR ENERGY RES INST,GOLDEN,CO 80401. RP ADESIDA, I (reprint author), UNIV ILLINOIS,CTR COMPOUND SEMICOND MICROELECTR,MAT RES LAB,URBANA,IL 61801, USA. RI Schaff, William/B-5839-2009 NR 13 TC 20 Z9 21 U1 0 U2 2 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 NOV-DEC PY 1991 VL 9 IS 6 BP 3551 EP 3554 DI 10.1116/1.585843 PG 4 WC Engineering, Electrical & Electronic; Nanoscience & Nanotechnology; Physics, Applied SC Engineering; Science & Technology - Other Topics; Physics GA GW423 UT WOS:A1991GW42300163 ER PT J AU ANDERSON, EH BOEGLI, V SCHATTENBURG, ML KERN, D SMITH, HI AF ANDERSON, EH BOEGLI, V SCHATTENBURG, ML KERN, D SMITH, HI TI METROLOGY OF ELECTRON-BEAM LITHOGRAPHY SYSTEMS USING HOLOGRAPHICALLY PRODUCED REFERENCE SAMPLES SO JOURNAL OF VACUUM SCIENCE & TECHNOLOGY B LA English DT Article; Proceedings Paper CT 35TH INTERNATIONAL SYMP ON ELECTRON, ION, AND PHOTON BEAMS CY MAY 28-31, 1991 CL SEATTLE, WA SP AMER VACUUM SOC, IEEE, ELECTR DEVICE, OPT SOC AMER AB Metrology in an electron-beam lithography system is typically carried out by a combination of beam scan and laser-interferometer-controlled sample motion. The high-resolution technique presented in this paper avoids the stage motion by using a holographically produced grid, which is essentially a permanently recorded interference pattern. This grid can be at least as accurate as the interferometer, and no stage motion, with the potential for additional error sources, is required to map out the distortion in the deflection field. The quality of the grid is critical since it is the reference to which the distortion is compared. With careful control of the holographic exposure system, high-quality low-distortion orthogonal grids were fabricated. We have produced grids with a period of 200 nm and orthogonality of a few arc seconds using an UV laser holographic system. Once the grid is processed to produce a high-contrast signal for either back-scattered or transmitted electrons, both scanning and signal-processing techniques are needed to measure the distortion. If the errors are larger or similar in size to the grating period a moire technique can be used. Unfortunately, when the distortion is much less than the period this technique does not have the required resolution. Therefore, two new techniques have been developed. The first uses a lock-in amplifier to measure the phase difference between the expected signal and the actual measured signal. The second uses digital image processing to compare the expected and measured images. With both of these techniques resolution of about one beam step (almost-equal-to 6 nm) has been achieved. C1 IBM CORP,THOMAS J WATSON RES CTR,YORKTOWN HTS,NY 10598. MIT,CAMBRIDGE,MA 02139. RP ANDERSON, EH (reprint author), UNIV CALIF BERKELEY,LAWRENCE BERKELEY LAB,BERKELEY,CA 94720, USA. NR 7 TC 29 Z9 30 U1 0 U2 7 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 NOV-DEC PY 1991 VL 9 IS 6 BP 3606 EP 3611 DI 10.1116/1.585854 PG 6 WC Engineering, Electrical & Electronic; Nanoscience & Nanotechnology; Physics, Applied SC Engineering; Science & Technology - Other Topics; Physics GA GW423 UT WOS:A1991GW42300174 ER PT J AU PAVLOVICKENTERA, V DJUKANOVIC, L CLEMONS, GK TRBOJEVIC, S DIMKOVIC, N SLAVKOVIC, A AF PAVLOVICKENTERA, V DJUKANOVIC, L CLEMONS, GK TRBOJEVIC, S DIMKOVIC, N SLAVKOVIC, A TI ANEMIA IN BALKAN ENDEMIC NEPHROPATHY SO KIDNEY INTERNATIONAL LA English DT Article ID ERYTHROPOIETIN AB The severity of anemia in patients at different stages of the evolution of two tubulointerstitial nephropathies, Balkan endemic nephropathy and chronic pyelonephritis, was compared to clarify the previous observations that anemia appears earlier and is more severe in Balkan endemic nephropathy than in other renal diseases. The role of erythropoietin insufficiency as the cause of anemia in endemic nephropathy was studied as well. The severity of anemia increased with the impairment of renal function in endemic nephropathy and was similar to anemia in chronic pyelonephritis. However, in patients with endemic nephropathy at the initial stage of renal insufficiency significantly lower red cell concentrations were found compared with control subjects from the endemic region. In contrast, patients with pyelonephritis did not have decreased red cell concentrations at the early phase of their renal failure, suggesting that earlier appearance of anemia is characteristic for endemic nephropathy. To confirm this finding a study involving larger number of patients would be necessary. The serum erythropoietin levels, inappropriately low for the degree of anemia in patients with renal failure, were unrelated to the type of tubulointerstitial nephropathy. C1 INST ENDEM NEPHROPATHY,LAZAREVAC,YUGOSLAVIA. UNIV CALIF BERKELEY LAWRENCE BERKELEY LAB,BERKELEY,CA 94720. UNIV BELGRADE,CTR CLIN,INST UROL & NEPHROL,BELGRADE,YUGOSLAVIA. ZVEZDARA CLIN HOSP,CTR INST KIDNEY DIS,BELGRADE,YUGOSLAVIA. RP PAVLOVICKENTERA, V (reprint author), INST MED RES,POB 721,YU-11001 BELGRADE,YUGOSLAVIA. NR 5 TC 4 Z9 4 U1 0 U2 0 PU BLACKWELL SCIENCE INC PI CAMBRIDGE PA 238 MAIN ST, CAMBRIDGE, MA 02142 SN 0085-2538 J9 KIDNEY INT JI Kidney Int. PD NOV PY 1991 VL 40 SU 34 BP S46 EP S48 PG 3 WC Urology & Nephrology SC Urology & Nephrology GA GL440 UT WOS:A1991GL44000014 ER PT J AU EVANS, JW AF EVANS, JW TI KINETIC PHASE-TRANSITIONS IN CATALYTIC REACTION MODELS SO LANGMUIR LA English DT Article ID SURFACE-REACTION MODEL; MEAN-FIELD THEORY; HETEROGENEOUS CATALYSIS; COMPUTER-SIMULATIONS; CRITICAL-BEHAVIOR; CARBON-MONOXIDE; CO OXIDATION; OSCILLATIONS; PERCOLATION; ADSORPTION AB We review and augment recent developments in the understanding of microscopic lattice-gas models for irreversible surface reactions where diffusion does not play a dominant role. Monomer-monomer reactions exhibit domain coarsening much slower than equilibrium Lifschitz-Cahn-Allen coarsening and instead reflect Voter model behavior. The monomer-dimer reaction is of particular interest as a model for CO oxidation. We provide a sophisticated characterization of the associated first- and second-order kinetic phase transitions (corresponding to poisoning) via ''epidemic analyses''. Here one considers the evolution of reaction starting from an empty patch embedded on an otherwise poisoned surface. C1 IOWA STATE UNIV SCI & TECHNOL,DEPT PHYS,AMES,IA 50011. IOWA STATE UNIV SCI & TECHNOL,DEPT MATH,AMES,IA 50011. RP EVANS, JW (reprint author), IOWA STATE UNIV SCI & TECHNOL,AMES LAB,AMES,IA 50011, USA. NR 49 TC 120 Z9 120 U1 1 U2 6 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 SN 0743-7463 J9 LANGMUIR JI Langmuir PD NOV PY 1991 VL 7 IS 11 BP 2514 EP 2519 DI 10.1021/la00059a020 PG 6 WC Chemistry, Multidisciplinary; Chemistry, Physical; Materials Science, Multidisciplinary SC Chemistry; Materials Science GA GQ894 UT WOS:A1991GQ89400023 ER PT J AU GLAND, JL FISCHER, DA PARKER, DH SHEN, S AF GLAND, JL FISCHER, DA PARKER, DH SHEN, S TI HYDROGEN CARBON-MONOXIDE INTERACTIONS ON METAL-SURFACES AT HIGH HYDROGEN COVERAGES SO LANGMUIR LA English DT Article ID PT(111) SURFACE; ADSORPTION; CO; NI(100); PLATINUM AB Carbon monoxide displacement has been observed for hydrogen pressures above 0.01 Torr on both the Pt(111) and Ni(100) surfaces. Displacement occurs well below the usual thermal desorption temperatures. ''Crowding'' or repulsive interactions between large coverages of coadsorbed atomic hydrogen and carbon monoxide are consistent with the displacement energetics and kinetics observed. Fluorescence yield near edge spectroscopy (FYNES), a new ultrasoft X-ray method, has been used as an in situ probe of CO surface coverages. Both isothermal and temperature programmed FYNES experiments have been used to characterize hydrogen-induced displacement of CO. On the Pt(111) surface in situ isothermal displacement experiments in the temperature range 318-348 K clearly indicate that CO displacement is a first-order process with an activation energy of about 11 kcal/mol in the presence 0.2 Torr of hydrogen. Activation energies for CO desorption decrease with increasing CO coverage from the 30 kcal/mol value measured in the limit of zero coverage; thus isothermal desorption in this name temperature range cannot be described by a simple first-order exponential process. Temperature-programmed FYNES experiments on the Pt-(111) surface indicate that at a temperature of 168 K even for hydrogen pressures below 0.2 Torr where CO displacement by hydrogen is not complete, hydrogen removes the (3(1/2) x 3(1/2)) compression structure observed for the saturated monolayer (0.67 ML) and induces the formation of the well-known (2 x 2) structure (0.5 ML) with reduced CO-CO repulsive interactions. On the Ni(100) surface in situ isothermal displacement experiments in the 278-330 K temperature range indicate that CO is rapidly displaced by hydrogen pressures above 1.0 x 10(-3) Torr. The displacement rate can be fit by two sequential first-order processes with activation energies of 7 kcal/mol for high CO coverages and 10 kcal/mol for lower CO coverages. These in situ soft X-ray displacement experiments have been independently confirmed by a series of mass spectrometric ex situ isothermal displacement experiments for both the Pt(111) and Ni(100) surfaces. Taken together these displacement experiments suggest that hydrogen-induced displacement processes may be general and clearly may play an important role in the transient behavior of catalytic processes run at ''high'' pressure. These displacement experiments also highlight the importance of understanding the chemistry of coadsorbed overlayers at extremely high coverages. In situ characterization of coadsorbed and surface reaction systems clearly offers an important general approach for discovering new surface phenomena which occur at high coverage and characterizing and establishing the primary mechanisms which govern these new phenomena. C1 BROOKHAVEN NATL LAB,EXXON PRT,NSLS,UPTON,NY 11973. UNIV CALIF IRVINE,DEPT CHEM,IRVINE,CA 92717. CHINESE ACAD SCI,LANZHOU INST CHEM PHYS,LANZHOU,PEOPLES R CHINA. RP GLAND, JL (reprint author), UNIV MICHIGAN,DEPT CHEM,ANN ARBOR,MI 48109, USA. NR 23 TC 13 Z9 13 U1 1 U2 2 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 SN 0743-7463 J9 LANGMUIR JI Langmuir PD NOV PY 1991 VL 7 IS 11 BP 2574 EP 2579 DI 10.1021/la00059a030 PG 6 WC Chemistry, Multidisciplinary; Chemistry, Physical; Materials Science, Multidisciplinary SC Chemistry; Materials Science GA GQ894 UT WOS:A1991GQ89400033 ER PT J AU WALCZAK, MM POPENOE, DD DEINHAMMER, RS LAMP, BD CHUNG, CK PORTER, MD AF WALCZAK, MM POPENOE, DD DEINHAMMER, RS LAMP, BD CHUNG, CK PORTER, MD TI REDUCTIVE DESORPTION OF ALKANETHIOLATE MONOLAYERS AT GOLD - A MEASURE OF SURFACE COVERAGE SO LANGMUIR LA English DT Article ID ORGANIZED MOLECULAR ASSEMBLIES; SCANNING TUNNELING MICROSCOPY; STRUCTURAL CHARACTERIZATION; ELECTRODES; FERROCENE; FILMS; ELECTROCHEMISTRY; COADSORPTION; THIOLS; SPECTROSCOPY AB An approach for the determination of the surface coverages of monolayer films formed by the chemisorption of thiol compounds at evaporated gold electrodes is described. The approach is based on the voltammetric measurement of the charge passed for the one-electron reductive desorption of the resulting gold-bound thiolate layer (Au-SR) in alkaline solution (pH > 11): Au-SR + e- --> Au(0) + -SR. The applicability of this approach is evaluated using monolayers formed from a methyl-terminated thiol (dodecanethiol) and two ferrocene-terminated thiols of differing polymethylene chain length. Coverages for the ferrocene-terminated layers are assessed by the reductive desorption process, the ferrocene-ferricenium redox transformation, and the loss of the adsorbate precursor from the film-formation solution. The coverages determined by all three methods are found to be comparable. For the methyl-terminated structure, the coverage from the reductive desorption measurement agrees with that expected for the (square-root 3BAR x square-root 3BAR) R30-degrees overlayer at Au(111) (the predominant crystal face of evaporated gold films) after accounting for surface roughness. In addition, general structural and reactivity characteristics of the ferrocene-terminated layers, as gleaned from the electrochemical measurements and from characterizations using infrared reflection absorption spectroscopy, are presented and compared with those of the methyl-terminated layer. Taken together, these results verify the utility of the reductive desorption measurement as a quantitative tool for determining the surface coverage of thiolate monolayers at gold. C1 US DOE,AMES LAB,AMES,IA 50011. IOWA STATE UNIV SCI & TECHNOL,DEPT CHEM,AMES,IA 50011. NR 60 TC 492 Z9 492 U1 5 U2 70 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 SN 0743-7463 J9 LANGMUIR JI Langmuir PD NOV PY 1991 VL 7 IS 11 BP 2687 EP 2693 DI 10.1021/la00059a048 PG 7 WC Chemistry, Multidisciplinary; Chemistry, Physical; Materials Science, Multidisciplinary SC Chemistry; Materials Science GA GQ894 UT WOS:A1991GQ89400051 ER PT J AU PFEIFER, P JOHNSTON, GP DESHPANDE, R SMITH, DM HURD, AJ AF PFEIFER, P JOHNSTON, GP DESHPANDE, R SMITH, DM HURD, AJ TI STRUCTURE-ANALYSIS OF POROUS SOLIDS FROM PREADSORBED FILMS SO LANGMUIR LA English DT Article ID SURFACE-ROUGHNESS; ADSORPTION; SCATTERING AB In this paper we explore the idea that the variation of the surface area of an adsorbed film on a porous solid, as a function of coverage (film volume), should yield structural information about the solid. We describe the formalizations for relating such film area measurements to surface roughness and micropore size distribution, showing that under weak thermodynamic and structural assumptions the two are uniquely related to each other. The surface roughness of four Cab-O-Sil fumed silicas, two phase-separated glasses (CPG and Vycor), and two silica xerogels are obtained from combined water-nitrogen adsorption experiments (nitrogen adsorption on preadsorbed water films) and compared to results from scattering and molecular tiling. Also, the surface roughness of various silica gels is assessed from the change in surface area when the surface is coated with surfactant or is derivatized. The micropore size distributions from film area measurements for Vycor and the xerogels are evaluated and compared to the results from micropore analysis, including Kelvin equation analysis, of nitrogen adsorption on the bare solids. The agreement between the film area results and the results from other methods, to the extent that they overlap, is excellent throughout. Specifically, we find that all of the Cab-O-Sils and the CPG glass are essentially smooth at length scales up to 1 nm. By contrast, Vycor and the base-catalyzed xerogel show an extended fractal behavior, with surface fractal dimension of 2.3 +/- 0.1 and 2.5 +/- 0.1, respectively, over a length range of about 0.2-10 nm (combination of all available data). C1 UNIV NEW MEXICO,NSF CTR MICROENGINEERED CERAM,ALBUQUERQUE,NM 87131. SANDIA NATL LABS,DIV 1841,ALBUQUERQUE,NM 87185. RP PFEIFER, P (reprint author), UNIV MISSOURI,DEPT PHYS,COLUMBIA,MO 65211, USA. NR 36 TC 22 Z9 24 U1 0 U2 3 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 SN 0743-7463 J9 LANGMUIR JI Langmuir PD NOV PY 1991 VL 7 IS 11 BP 2833 EP 2843 DI 10.1021/la00059a069 PG 11 WC Chemistry, Multidisciplinary; Chemistry, Physical; Materials Science, Multidisciplinary SC Chemistry; Materials Science GA GQ894 UT WOS:A1991GQ89400072 ER PT J AU PERRY, MD OLSON, R AF PERRY, MD OLSON, R TI LICAF AND LISAF AMPLIFY TUNABLE LASER-PULSES SO LASER FOCUS WORLD LA English DT Article C1 POSIT LIGHT INC,FELTON,CA 95018. RP PERRY, MD (reprint author), UNIV CALIF LAWRENCE LIVERMORE NATL LAB,LASER PROGRAM,MAILSTOP L-493,LIVERMORE,CA 94550, USA. NR 6 TC 5 Z9 5 U1 0 U2 0 PU PENNWELL PUBL CO PI NASHUA PA 5TH FLOOR TEN TARA BOULEVARD, NASHUA, NH 03062-2801 SN 0740-2511 J9 LASER FOCUS WORLD JI Laser Focus World PD NOV PY 1991 VL 27 IS 11 BP 69 EP & PG 0 WC Optics SC Optics GA GP405 UT WOS:A1991GP40500016 ER PT J AU OGIEVETSKY, O SCHMIDKE, WB WESS, J ZUMINO, B AF OGIEVETSKY, O SCHMIDKE, WB WESS, J ZUMINO, B TI 6 GENERATOR Q-DEFORMED LORENTZ ALGEBRA SO LETTERS IN MATHEMATICAL PHYSICS LA English DT Article AB The six generator deformation of the Lorentz algebra is presented. The Hopf algebra structure and the reality conditions are found. The chiral decomposition of SL(2, C) is generalized to the q-case. Casimir operators for the q-Lorentz algebra are given. C1 UNIV MUNICH,SEKT PHYS,W-8000 MUNICH 2,GERMANY. UNIV CALIF BERKELEY,LAWRENCE BERKELEY LAB,DIV PHYS,THEORET PHYS GRP,BERKELEY,CA 94720. UNIV CALIF BERKELEY,DEPT PHYS,BERKELEY,CA 94720. RP OGIEVETSKY, O (reprint author), MAX PLANCK INST PHYS & ASTROPHYS,WERNER HEISENBERG INST PHYS,POB 40 12 12,W-8000 MUNICH 40,GERMANY. RI Ogievetsky, Oleg/N-4540-2015 NR 5 TC 37 Z9 37 U1 0 U2 2 PU KLUWER ACADEMIC PUBL PI DORDRECHT PA SPUIBOULEVARD 50, PO BOX 17, 3300 AA DORDRECHT, NETHERLANDS SN 0377-9017 J9 LETT MATH PHYS JI Lett. Math. Phys. PD NOV PY 1991 VL 23 IS 3 BP 233 EP 240 DI 10.1007/BF01885501 PG 8 WC Physics, Mathematical SC Physics GA HE132 UT WOS:A1991HE13200007 ER PT J AU HILL, WR BOSTON, HL AF HILL, WR BOSTON, HL TI COMMUNITY-DEVELOPMENT ALTERS PHOTOSYNTHESIS IRRADIANCE RELATIONS IN STREAM PERIPHYTON SO LIMNOLOGY AND OCEANOGRAPHY LA English DT Article ID RIVER COMMUNITY; LIGHT; PHYTOPLANKTON; RESPONSES; ALGAE; ASSEMBLAGES; ADAPTATION; SUBSTRATE; EPILITHON; DENSITY AB The effects of biomass accumulation and community age on the photosynthesis-irradiance response of periphyton were examined in developmental sequences from three stream locations that differed in canopy cover. Photosynthesis-irradiance (P-I) curves for four developmental stages from each location were constructed from C-14 uptake at six irradiances (22-1,100-mu-mol quanta m-2 s-1) in the laboratory. Photoinhibition in the periphyton from the two shaded sites declined with development, indicating that self-shading significantly influenced photosynthesis in older communities. Photoinhibition was absent, however, in all of the developmental stages from the high light site. Maximum photosynthesis (P(max)) and slope (alpha) of the light-limited portion of the chlorophyll-specific light response decreased > 40% in developing periphyton at all sites. Significant negative correlations between biomass and biomass-specific P(max) suggested that light or metabolic substrates became progressively more limiting during development. Although there was little community-level evidence of shade adaptation during development (photosynthesis did not saturate at lower light intensities as development proceeded), periphyton understories appear to retain considerable photosynthetic potential despite significant shading by upper layers. RP HILL, WR (reprint author), OAK RIDGE NATL LAB,DIV ENVIRONM SCI,POB 2008,OAK RIDGE,TN 37831, USA. NR 31 TC 79 Z9 81 U1 1 U2 19 PU AMER SOC LIMNOLOGY OCEANOGRAPH PI LAWRENCE PA 810 EAST 10TH ST, LAWRENCE, KS 66044-8897 SN 0024-3590 J9 LIMNOL OCEANOGR JI Limnol. Oceanogr. PD NOV PY 1991 VL 36 IS 7 BP 1375 EP 1389 PG 15 WC Limnology; Oceanography SC Marine & Freshwater Biology; Oceanography GA HE784 UT WOS:A1991HE78400009 ER PT J AU SANCETTA, C VILLAREAL, T FALKOWSKI, P AF SANCETTA, C VILLAREAL, T FALKOWSKI, P TI MASSIVE FLUXES OF RHIZOSOLENID DIATOMS - A COMMON OCCURRENCE SO LIMNOLOGY AND OCEANOGRAPHY LA English DT Note ID SUBARCTIC PACIFIC; NITROGEN-FIXATION; SINKING; OCEAN; MATS AB The potential nonlinearities in the relationship between vertical flux of material to the deep sea and rates of production in the surface water include the possibility that stochastic events are responsible for a large proportion of export below the euphotic zone. It has been suggested that large diatoms might play a role in such export production. We summarize data sets referring specifically to the rhizosolenid diatoms, including several not previously published, and show that mass sinking of rhizosolenids may be a common occurrence. C1 WOODS HOLE OCEANOG INST,WOODS HOLE,MA 02543. BROOKHAVEN NATL LAB,UPTON,NY 11973. RP SANCETTA, C (reprint author), COLUMBIA UNIV,LAMONT DOHERTY GEOL OBSERV,PALISADES,NY 10964, USA. NR 26 TC 63 Z9 66 U1 0 U2 3 PU AMER SOC LIMNOLOGY OCEANOGRAPH PI LAWRENCE PA 810 EAST 10TH ST, LAWRENCE, KS 66044-8897 SN 0024-3590 J9 LIMNOL OCEANOGR JI Limnol. Oceanogr. PD NOV PY 1991 VL 36 IS 7 BP 1452 EP 1457 PG 6 WC Limnology; Oceanography SC Marine & Freshwater Biology; Oceanography GA HE784 UT WOS:A1991HE78400016 ER PT J AU MCCLUNG, RW AF MCCLUNG, RW TI REFERENCES FOR LOW-ENERGY RADIOGRAPHY SO MATERIALS EVALUATION LA English DT Letter RP MCCLUNG, RW (reprint author), OAK RIDGE NATL LAB,OAK RIDGE,TN, USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU AMER SOC NON-DESTRUCTIVE TEST PI COLUMBUS PA 1711 ARLINGATE LANE PO BOX 28518, COLUMBUS, OH 43228-0518 SN 0025-5327 J9 MATER EVAL JI Mater. Eval. PD NOV PY 1991 VL 49 IS 11 BP 1365 EP 1365 PG 1 WC Materials Science, Characterization & Testing SC Materials Science GA GP111 UT WOS:A1991GP11100006 ER PT J AU SIMPSON, WA MCCLUNG, RW AF SIMPSON, WA MCCLUNG, RW TI QUANTITATIVE ATTENUATION TECHNIQUE FOR MATERIALS CHARACTERIZATION SO MATERIALS EVALUATION LA English DT Article DE ACOUSTICS; AEROSPACE; ATTENUATION; COMPOSITE MATERIAL; MATERIAL CHARACTERIZATION; NONDESTRUCTIVE EVALUATION; NUCLEAR INDUSTRY; PLASTICS; QUALITY ASSURANCE; SIGNAL PROCESSING; STEEL; ULTRASONIC TESTING; WELD TESTING AB A quantitative knowledge of ultrasonic attenuation in material being nondestructively examined is important for flaw detection and analysis as well as for material characterization. In flaw detection, the degree of ultrasonic attenuation affects the ultrasonic frequencies that can be transmitted effectively through the inspected material. The attenuation is affected by the grain size, distributed flaws, and other microstructural properties of the material. A quantitative technique for measuring ultrasonic attenuation as a function of frequency has been developed and applied to many different materials, including plastic, graphite, stainless steel, aluminum, fiber-reinforced plastic (FRP) composites, and ceramics. RP SIMPSON, WA (reprint author), OAK RIDGE NATL LAB,DIV MET & CERAM,NONDESTRUCT TESTING GRP,POB 2008,OAK RIDGE,TN 37831, USA. NR 0 TC 4 Z9 4 U1 0 U2 0 PU AMER SOC NON-DESTRUCTIVE TEST PI COLUMBUS PA 1711 ARLINGATE LANE PO BOX 28518, COLUMBUS, OH 43228-0518 SN 0025-5327 J9 MATER EVAL JI Mater. Eval. PD NOV PY 1991 VL 49 IS 11 BP 1409 EP 1413 PG 5 WC Materials Science, Characterization & Testing SC Materials Science GA GP111 UT WOS:A1991GP11100012 ER PT J AU ROSS, J RUBIN, M AF ROSS, J RUBIN, M TI HIGH-QUALITY GAN GROWN BY REACTIVE SPUTTERING SO MATERIALS LETTERS LA English DT Article ID NITRIDE THIN-FILMS; GALLIUM NITRIDE AB Gallium nitride films were grown by reactive rf magnetron sputtering on sapphire substrates. Crystalline (1120BAR) GaN films were obtained on (0112BAR) sapphire at substrate temperatures between 640 and 680-degrees-C. High N2 partial pressures are required to crystallize the GaN films. Nitrogen incorporation and crystal quality of GaN films are examined as a function of substrate temperature and nitrogen partial pressure. Band gaps of 3.4 eV, and photoluminescence peaks as narrow as 11 meV are reported for sputtered GaN films. RP ROSS, J (reprint author), UNIV CALIF BERKELEY,LAWRENCE BERKELEY LAB,BERKELEY,CA 94720, USA. NR 9 TC 26 Z9 26 U1 0 U2 4 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0167-577X J9 MATER LETT JI Mater. Lett. PD NOV PY 1991 VL 12 IS 4 BP 215 EP 218 DI 10.1016/0167-577X(91)90001-M PG 4 WC Materials Science, Multidisciplinary; Physics, Applied SC Materials Science; Physics GA GR928 UT WOS:A1991GR92800001 ER PT J AU RISCH, GA LANAGAN, MT WU, W GORETTA, KC MOON, BM AF RISCH, GA LANAGAN, MT WU, W GORETTA, KC MOON, BM TI YBA2CU3OX PROCESSED WITH A SILVER PALLADIUM ALLOY SO MATERIALS LETTERS LA English DT Article ID BA-CU-O; CURRENT-DENSITY; SUPERCONDUCTORS AB YBa2Cu3O(x) powders were sintered in sealed Ag and Ag/10% Pd wraps and melted on Ag/10% Pd foils. The melting was performed at 980-degrees-C under an O2 pressure of 10(3) Pa. Although YBa2Cu3O(x) was successfully melt-processed, some interdiffusion occurred between it and the Ag/Pd alloy. The superconducting transition temperature was 86-88 K for YBa2Cu3O(x) processed with Ag/Pd alloy and 89 K for YBa2Cu3O(x) processed with pure Ag. C1 UNIV ILLINOIS,SCI & TECHNOL CTR SUPERCONDUCT,URBANA,IL 61801. RP RISCH, GA (reprint author), ARGONNE NATL LAB,DIV MAT & COMPONENTS TECHNOL,ARGONNE,IL 60439, USA. NR 21 TC 4 Z9 4 U1 0 U2 0 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0167-577X J9 MATER LETT JI Mater. Lett. PD NOV PY 1991 VL 12 IS 4 BP 291 EP 294 DI 10.1016/0167-577X(91)90016-Y PG 4 WC Materials Science, Multidisciplinary; Physics, Applied SC Materials Science; Physics GA GR928 UT WOS:A1991GR92800016 ER PT J AU SWARNALATHA, M STEWART, AF GUENTHER, AH CARNIGLIA, CK AF SWARNALATHA, M STEWART, AF GUENTHER, AH CARNIGLIA, CK TI LASER-FUSED REFRACTORY OXIDES FOR OPTICAL COATINGS SO MATERIALS SCIENCE AND ENGINEERING B-SOLID STATE MATERIALS FOR ADVANCED TECHNOLOGY LA English DT Article ID FILMS; HAFNIUM AB Laser sintering was carried out using a high power continuous-wave CO2 laser to prepare pellets of zirconia (ZrO2), hafnia (HfO2) and yttria (Y2O3) mixed oxides as starting materials in the deposition of optical coatings. Hardened recrystallized pellets appeared to have been formed during laser treatment. X-ray diffraction analysis revealed a monoclinic-to-tetragonal phase transformation in the binary system while the ternary system was found to have a mixture of two crystalline phases. Cross-sectional scanning electron microscopy showed two isothermal crystalline regions in the ternary system. The optical inhomogeneity was low in the films deposited from the laser-fused pellets, but the absorption at a wavelength of 351 nm increased with increasing HfO2 content. The films deposited from laser-fused pellets were analysed by electron spectroscopy for chemical analysis and found to be stoichiometric and homogeneous. C1 LITTON GUIDANCE & MISSILE SYST,LOS ANGELES,CA 91367. S SYST CORP,ALBUQUERQUE,NM 87119. UNIV CALIF LOS ALAMOS SCI LAB,LOS ALAMOS,NM 87545. RP SWARNALATHA, M (reprint author), INDIAN INST SCI,INSTRUMENTAT & SERV UNIT,BANGALORE 5600033,INDIA. NR 14 TC 2 Z9 2 U1 0 U2 1 PU ELSEVIER SCIENCE SA LAUSANNE PI LAUSANNE 1 PA PO BOX 564, 1001 LAUSANNE 1, SWITZERLAND SN 0921-5107 J9 MAT SCI ENG B-SOLID JI Mater. Sci. Eng. B-Solid State Mater. Adv. Technol. PD NOV PY 1991 VL 10 IS 3 BP 241 EP 246 DI 10.1016/0921-5107(91)90131-E PG 6 WC Materials Science, Multidisciplinary; Physics, Condensed Matter SC Materials Science; Physics GA GQ567 UT WOS:A1991GQ56700009 ER PT J AU NAGASAWA, A KITA, K MORII, Y FUCHIZAKI, K KATANO, S FUNAHASHI, S CHILD, HR AF NAGASAWA, A KITA, K MORII, Y FUCHIZAKI, K KATANO, S FUNAHASHI, S CHILD, HR TI OMEGA-LIKE DIFFRACTION ANOMALY IN THE PREMARTENSITIC BETA-1 PHASE OF AUCUZN2 ALLOY SO MATERIALS TRANSACTIONS JIM LA English DT Article DE OMEGA-LIKE PEAK; OMEGA-PHASE; BETA-PHASE ALLOYS; ORDERING; QUENCHED-IN VACANCIES; 6-JUMP VACANCY CYCLES; INCOMPLETELY ORDERED B2-PHASE; HEUSLER TYPE STRUCTURE; MARTENSITIC TRANSFORMATION; PHONON DISPERSION ID LATTICE INSTABILITY; NEUTRON-SCATTERING; TRANSFORMATION; TRANSITION; STATE; MODE AB The present study by X-ray and neutron diffraction methods is concerned with the omega-like peak appearing at the positions (H +/- 2/3, K +/- 2/3, L +/- 4/3) and (H +/- 2/3, K +/- 2/3, L -/+ 4/3) in the reciprocal lattice of the quenched beta(1) phase with the Heusler type structure of AuCuZn2. The obtained results indicate evidently that the omega-like peak is neither due to the omega phase formation as is the case of Zr alloy nor precursor phenomenon of the martensitic transformation. It is originated from a certain kind of regular arrangement of vacancies in the incompletely ordered B2 phase: the vacancies are responsible for the ordering reaction to the Heusler type structure occurring at about 670 K. They are frozen into the Heusler phase formed by quenching, and hence the quenched Heusler phase exhibits the omega-like peak as observed. The peak disappears with vacancy annihilation from the Heusler type beta(1) phase. Characteristics of both the [111]LA and [112BAR]TA phonon dispersion relations also support this conclusion. C1 OAK RIDGE NATL LAB,DIV SOLID STATE,OAK RIDGE,TN 37831. JAPAN ATOM ENERGY RES INST,DEPT PHYS,TOKAI,IBARAKI 31911,JAPAN. RP NAGASAWA, A (reprint author), NARA WOMENS UNIV,DEPT PHYS,NARA 630,JAPAN. NR 22 TC 3 Z9 3 U1 0 U2 1 PU JAPAN INST METALS PI SENDAI PA AOBA ARAMAKI, SENDAI 980, JAPAN SN 0916-1821 J9 MATER T JIM JI Mater. Trans. JIM PD NOV PY 1991 VL 32 IS 11 BP 1011 EP 1016 PG 6 WC Materials Science, Multidisciplinary; Metallurgy & Metallurgical Engineering SC Materials Science; Metallurgy & Metallurgical Engineering GA GZ547 UT WOS:A1991GZ54700002 ER PT J AU HUGHES, ED AF HUGHES, ED TI TEXS ROUGH RIDE SO MECHANICAL ENGINEERING LA English DT Letter RP HUGHES, ED (reprint author), EG&G IDAHO INC,IDAHO FALLS,ID 83401, USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU ASME-AMER SOC MECHANICAL ENG PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 SN 0025-6501 J9 MECH ENG JI Mech. Eng. PD NOV PY 1991 VL 113 IS 11 BP 73 EP 73 PG 1 WC Engineering, Mechanical SC Engineering GA GN834 UT WOS:A1991GN83400016 ER PT J AU COUTRAKON, G BAUMAN, M LESYNA, D MILLER, D NUSBAUM, J SLATER, J JOHANNING, J MIRANDA, J DELUCA, PM SIEBERS, J LUDEWIGT, B AF COUTRAKON, G BAUMAN, M LESYNA, D MILLER, D NUSBAUM, J SLATER, J JOHANNING, J MIRANDA, J DELUCA, PM SIEBERS, J LUDEWIGT, B TI A PROTOTYPE BEAM DELIVERY SYSTEM FOR THE PROTON MEDICAL ACCELERATOR AT LOMA-LINDA SO MEDICAL PHYSICS LA English DT Article DE PROTON; MEDICAL ACCELERATOR; BEAM DELIVERY SYSTEM; BRAGG PEAK AB A variable energy proton accelerator was commissioned at Fermi National Accelerator Laboratory for use in cancer treatment at the Loma Linda University Medical Center. The advantages of precise dose localization by proton therapy, while sparing nearby healthy tissue, are well documented [R. R. Wilson, Radiology 47, 487 (1946); M. Wagner, Med. Phys. 9, 749 (1982); M. Goitein and F. Chen, Med. Phys. 10, 831 (1983)]. One of the components of the proton therapy facility is a beam delivery system capable of delivering precise dose distributions to the target volume in the patient. To this end, a prototype beam delivery system was tested during the accelerator's commissioning period. The beam delivery system consisted of a beam spreading device to produce a large, uniform field, a range modulator to generate a spread out Bragg peak (SOBP), and various beam detectors to measure intensity, beam centering, and dose distributions. The beam delivery system provided a uniform proton dose distribution in a cylindrical volume of 20-cm-diam area and 9-cm depth. The dose variations throughout the target volume were found to be less then +/- 5%. Modifications in the range modulator should reduce this considerably. The central axis dose rate in the region of the SOBP was found to be 0.4 cGy/spill with an incident beam intensity of 6.7 x 10(9) protons/spill. With an accelerator repetition rate of 30 spills/min and expected intensity of 2.5 x 10(10) protons/spill for patient treatment, this system can provide 50 cGy/min for a 20-cm-diam field and 9-cm range modulation. The distal edge of the spread out Bragg peak was observed at 27.5-cm depth with an incident proton energy of 235 MeV. The dose at the distal edge falls from 90% to 10% of the peak value in 7 mm. The 90%-10% penumbras as small as 6 mm were measured at 3-cm depth without range shifter material in the beam and as large as 15 mm when measured at 25-cm depth with 10 cm of range shifter placed in the beam. The unmodulated Bragg curve had a peak to entrance dose ratio of 3, while the peak to entrance dose ratio for the 9-cm spread out Bragg peak was observed to be only 1.3. C1 UNIV WISCONSIN,DEPT MED PHYS,MADISON,WI 53706. UNIV CALIF BERKELEY,LAWRENCE BERKELEY LAB,BERKELEY,CA 94720. RP COUTRAKON, G (reprint author), LOMA LINDA UNIV,MED CTR,11234 ANDERSON ST,POB 2000,LOMA LINDA,CA 92354, USA. NR 7 TC 33 Z9 33 U1 1 U2 3 PU AMER INST PHYSICS PI WOODBURY PA CIRCULATION FULFILLMENT DIV, 500 SUNNYSIDE BLVD, WOODBURY, NY 11797-2999 SN 0094-2405 J9 MED PHYS JI Med. Phys. PD NOV-DEC PY 1991 VL 18 IS 6 BP 1093 EP 1099 DI 10.1118/1.596617 PG 7 WC Radiology, Nuclear Medicine & Medical Imaging SC Radiology, Nuclear Medicine & Medical Imaging GA GQ085 UT WOS:A1991GQ08500002 PM 1661367 ER PT J AU DAFTARI, I PETTI, PL COLLIER, JM CASTRO, JR PITLUCK, S AF DAFTARI, I PETTI, PL COLLIER, JM CASTRO, JR PITLUCK, S TI THE EFFECT OF PATIENT MOTION ON DOSE UNCERTAINTY IN CHARGED-PARTICLE IRRADIATION FOR LESIONS ENCIRCLING THE BRAIN-STEM OR SPINAL-CORD SO MEDICAL PHYSICS LA English DT Article DE CHARGED-PARTICLE THERAPY; LOCALIZATION ACCURACY; PATIENT MOTION; TREATMENT PLANNING ID RADIATION-THERAPY; VOLUME HISTOGRAMS; RADIOTHERAPY; TOLERANCE AB A specialized charged-particle radiotherapy technique developed at Lawrence Berkeley Laboratory (LBL) is applied to patients with lesions abutting or surrounding the spinal cord or brain stem. This technique divides the target into two parts, one partially surrounding the critical structure (brain stem or spinal cord) and a second excluding the critical structure and abutting the first portion of the target. Compensators are used to conform the dose distribution to the distal surface of the target. This technique represents a novel approach in treating unresectable or residual tumors surrounding the spinal cord or brain stem. Since the placement of the patient with respect to beam-shaping devices is critical for divided-target treatments, a method for calculating dose distributions reflecting random patient motion is proposed, and the effects of random patient motion are studied for two divided-target patient examples. Dose-volume histograms and a normal-tissue complication probability model are used in this analysis. For the patients considered in this study, the normal-tissue-complication probability model predicts that random patient motion less than or equal to 0.2 cm is tolerable in terms of spinal cord complications. RP DAFTARI, I (reprint author), UNIV CALIF BERKELEY,LAWRENCE BERKELEY LAB,DIV RES MED & RADIAT BIOPHYS,BERKELEY,CA 94720, USA. FU NCI NIH HHS [CA19138] NR 21 TC 7 Z9 7 U1 0 U2 0 PU AMER INST PHYSICS PI WOODBURY PA CIRCULATION FULFILLMENT DIV, 500 SUNNYSIDE BLVD, WOODBURY, NY 11797-2999 SN 0094-2405 J9 MED PHYS JI Med. Phys. PD NOV-DEC PY 1991 VL 18 IS 6 BP 1105 EP 1115 DI 10.1118/1.596619 PG 11 WC Radiology, Nuclear Medicine & Medical Imaging SC Radiology, Nuclear Medicine & Medical Imaging GA GQ085 UT WOS:A1991GQ08500004 PM 1753891 ER PT J AU BUTLER, BD COHEN, JB ZSCHACK, P AF BUTLER, BD COHEN, JB ZSCHACK, P TI AN INVESTIGATION OF FE-NI ORDER IN A STEEL SO METALLURGICAL TRANSACTIONS A-PHYSICAL METALLURGY AND MATERIALS SCIENCE LA English DT Note C1 NORTHWESTERN UNIV,MCCORMICK SCH ENGN & APPL SCI,DEPT MAT SCI & ENGN,EVANSTON,IL 60208. OAK RIDGE NATL LAB,DIV MET & CERAM,OAK RIDGE,TN 37831. RP BUTLER, BD (reprint author), AUSTRALIAN NATL UNIV,RES SCH CHEM,CANBERRA,ACT 2601,AUSTRALIA. NR 14 TC 6 Z9 6 U1 0 U2 1 PU MINERALS METALS MATERIALS SOC PI WARRENDALE PA 420 COMMONWEALTH DR, WARRENDALE, PA 15086 SN 0360-2133 J9 METALL TRANS A PD NOV PY 1991 VL 22 IS 11 BP 2807 EP 2809 DI 10.1007/BF02851374 PG 3 WC Materials Science, Multidisciplinary SC Materials Science GA GP092 UT WOS:A1991GP09200027 ER PT J AU GLESNE, DA COLLART, FR HUBERMAN, E AF GLESNE, DA COLLART, FR HUBERMAN, E TI REGULATION OF IMP DEHYDROGENASE GENE-EXPRESSION BY ITS END-PRODUCTS, GUANINE-NUCLEOTIDES SO MOLECULAR AND CELLULAR BIOLOGY LA English DT Article ID PURINE NUCLEOSIDE PHOSPHORYLASE; MYCOPHENOLIC-ACID; MESSENGER-RNA; TRANSCRIPTION ELONGATION; CELL-DIFFERENTIATION; LEUKEMIA-CELLS; TOXICITY; PROTEIN; DNA; AMPLIFICATION AB To study the regulation of IMP dehydrogenase (IMPDH), the rate-limiting enzyme of guanine nucleotide biosynthesis, we examined the effects of nucleosides, nucleotides, nucleotide analogs, or the IMPDH inhibitor mycophenolic acid (MPA) on the steady-state levels of IMPDH mRNA. The results indicated that IMPDH gene expression is regulated inversely by the intracellular level of guanine ribonucleotides. We have shown that treatment with guanosine increased the level of cellular guanine ribonucleotides and subsequently reduced IMPDH steady-state mRNA levels in a time- and dose-dependent manner. Conversely, MPA treatment diminished the level of guanine ribonucleotides and increased IMPDH mRNA levels. Both of these effects on the steady-state level of IMPDH mRNA could be negated by cotreatment with guanosine and MPA. The down regulation of IMPDH gene expression by guanosine or its up regulation by MPA was not due to major changes in transcriptional initiation and elongation or mRNA stability in the cytoplasm but rather was due to alterations in the levels of the IMPDH mRNA in the nucleus. These results suggest that IMPDH gene expression is regulated by a posttranscriptional, nuclear event in response to fluctuations in the intracellular level of guanine ribonucleotides. C1 ARGONNE NATL LAB,DIV BIOL & MED RES,9700 S CASS AVE,ARGONNE,IL 60439. UNIV CHICAGO,DEPT MOLEC GENET & CELL BIOL,CHICAGO,IL 60637. OI Collart, Frank/0000-0001-6942-4483 FU NIGMS NIH HHS [GM07183] NR 33 TC 67 Z9 67 U1 0 U2 2 PU AMER SOC MICROBIOLOGY PI WASHINGTON PA 1325 MASSACHUSETTS AVENUE, NW, WASHINGTON, DC 20005-4171 SN 0270-7306 J9 MOL CELL BIOL JI Mol. Cell. Biol. PD NOV PY 1991 VL 11 IS 11 BP 5417 EP 5425 PG 9 WC Biochemistry & Molecular Biology; Cell Biology SC Biochemistry & Molecular Biology; Cell Biology GA GL382 UT WOS:A1991GL38200004 PM 1717828 ER PT J AU FEE, JA AF FEE, JA TI REGULATION OF SOD GENES IN ESCHERICHIA-COLI - RELEVANCE TO SUPEROXIDE-DISMUTASE FUNCTION SO MOLECULAR MICROBIOLOGY LA English DT Review ID MEDIATING REPRESSION; PARAQUAT TOXICITY; AEROBIC PATHWAYS; OXIDATIVE STRESS; POSITIVE CONTROL; MANGANESE; BIOSYNTHESIS; IRON; INDUCTION; PROTEIN AB This review is concerned with the effects of environmental perturbations on the expression of the two superoxide dismutase (SOD) genes in Escherichia coli (sodA, MnSOD; sodB, FeSOD). Early studies using SOD activity, showed that MnSOD levels respond to changes in oxygen tension, type of substrate, redox active compounds, iron concentration, the nature of the terminal oxidant, and the redox potential of the medium. FeSOD levels appeared nominally insensitive to these perturbations. More recent molecular genetic studies revealed that sodA expression is subject to regulation by three major regulatory systems: fur(ferric uptake regulation) and arcA arcB (aerobic respiratory control) mediate repression of sodA, while a relatively new system, soxR soxS (superoxide response), mediates activation of sodA expression. By contrast, sodB expression, which is much less studied at this time, appears to be positively activated in trans by fur. A rudimentary gene regulation model is presented which rationalizes past observations, is experimentally testable, and should serve as a guide to future research in this area. C1 UNIV CALIF LOS ALAMOS SCI LAB,STABLE ISOTOPE RESOURCE ISOTOPE & STRUCT CHEM GRP,LOS ALAMOS,NM 87545. RP FEE, JA (reprint author), UNIV CALIF LOS ALAMOS SCI LAB,BIOCHEM SECT,LOS ALAMOS,NM 87545, USA. FU NIGMS NIH HHS [GM35189] NR 78 TC 76 Z9 78 U1 1 U2 12 PU BLACKWELL SCIENCE LTD PI OXFORD PA OSNEY MEAD, OXFORD, OXON, ENGLAND OX2 0EL SN 0950-382X J9 MOL MICROBIOL JI Mol. Microbiol. PD NOV PY 1991 VL 5 IS 11 BP 2599 EP 2610 DI 10.1111/j.1365-2958.1991.tb01968.x PG 12 WC Biochemistry & Molecular Biology; Microbiology SC Biochemistry & Molecular Biology; Microbiology GA GT131 UT WOS:A1991GT13100005 PM 1779751 ER PT J AU KOSTRIKIS, LG REISBERG, SA SIMON, MN WALL, JS DAY, LA AF KOSTRIKIS, LG REISBERG, SA SIMON, MN WALL, JS DAY, LA TI EXPORT OF INFECTIOUS PARTICLES BY ESCHERICHIA-COLI TRANSFECTED WITH THE RF DNA OF PF1, A VIRUS OF PSEUDOMONAS-AERUGINOSA STRAIN-K SO MOLECULAR MICROBIOLOGY LA English DT Article ID FILAMENTOUS BACTERIAL VIRUSES; MOLECULAR ARCHITECTURE; BACTERIOPHAGE; PROTEIN; MEMBRANE; VIRION; PHAGE; HOST; FD AB Pf1 is a filamentous, single-stranded DNA virus that has Pseudomas aeruginosa (strain K) as host. It is the longest of the filamentous bacterial viruses, and the DNA within it has the most extended conformation known. Pf1 virus cannot infect Escherichia coli (strain MM294) cells, but when these cells are transfected with the double-stranded replicative form of Pf1 DNA (RF DNA, 7.35 kb), they export low levels of infectious particles that create plaques on lawns of P. aeruginosa. Several different structural species, at least two of which are infectious, are exported. One of them, called Epf1, has virtually the same structure as Pf1, but the amount of Epf1 exported by E. coli is 10(4) lower than the amount of Pf1 exported by P. aeruginosa. The results imply that host factors affect not only the efficiency of virus assembly and export, but also the actual structures of the species exported. C1 PUBL HLTH RES INST CITY NEW YORK INC,455 1ST AVE,NEW YORK,NY 10016. BROOKHAVEN NATL LAB,DEPT BIOL,UPTON,NY 11973. RI Kostrikis, Leondios/A-5330-2016 OI Kostrikis, Leondios/0000-0002-5340-7109 FU NCRR NIH HHS [RR 01777]; NIGMS NIH HHS [GM 42286-22] NR 28 TC 4 Z9 4 U1 0 U2 0 PU BLACKWELL SCIENCE LTD PI OXFORD PA OSNEY MEAD, OXFORD, OXON, ENGLAND OX2 0EL SN 0950-382X J9 MOL MICROBIOL JI Mol. Microbiol. PD NOV PY 1991 VL 5 IS 11 BP 2641 EP 2647 DI 10.1111/j.1365-2958.1991.tb01973.x PG 7 WC Biochemistry & Molecular Biology; Microbiology SC Biochemistry & Molecular Biology; Microbiology GA GT131 UT WOS:A1991GT13100010 PM 1779755 ER PT J AU ZHU, Y TAFTO, J SUENAGA, M AF ZHU, Y TAFTO, J SUENAGA, M TI DEFECTS IN HIGH-TC CUPRATE SUPERCONDUCTORS SO MRS BULLETIN LA English DT Article RP ZHU, Y (reprint author), BROOKHAVEN NATL LAB,DIV MAT SCI,UPTON,NY 11973, USA. NR 0 TC 18 Z9 19 U1 0 U2 0 PU MATERIALS RESEARCH SOCIETY PI PITTSBURGH PA 9800 MC KNIGHT ROAD SUITE 327, PITTSBURGH, PA 15237 SN 0883-7694 J9 MRS BULL JI MRS Bull. PD NOV PY 1991 VL 16 IS 11 BP 54 EP 59 PG 6 WC Materials Science, Multidisciplinary; Physics, Applied SC Materials Science; Physics GA GQ096 UT WOS:A1991GQ09600007 ER PT J AU JONES, TD EASTERLY, CE AF JONES, TD EASTERLY, CE TI ON THE RODENT BIOASSAYS CURRENTLY BEING CONDUCTED ON 44 CHEMICALS - A RASH ANALYSIS TO PREDICT TEST-RESULTS FROM THE NATIONAL TOXICOLOGY PROGRAM SO MUTAGENESIS LA English DT Article ID CARCINOGENIC RISK ASSESSMENTS; CELL-PROLIFERATION; UNIFYING CONCEPT; PROMOTION; RADIATION; EPIDERMIS; SKIN; MICE AB We use a method of relative potency comparisons to rank the potential strength of 44 compounds being tested in rodent carcinogenicity bioassays. All of our previous hazard evaluations have been for human conditions where great numbers of simultaneous and serial exposures may act in combination to produce a neoplasm comprised of 2(20) to 2(30) cells commonly expected to derive from a single precancerous cell. For human exposures, we have always assumed an initiated target tissue containing at least one transformed but subcarcinogenic cell per organ. Thus, for man we have focused on empirical correspondences that may help to index the monoclonal growth of a particular cell lineage during cancer expansion. In contrast to humans, initiation of target tissues in animals subjected to National Toxicity Program (NTP) bioassays may not be a given condition, because of extensive precautions taken to minimize exposures to contaminates in food, water and cage environments. For this evaluation, we used categorical assignments of 'unlikely', 'possible' and 'probable' carcinogens adapted from NTP tests. Our rank ordering, of compounds according to maximum doses tested in male mice and male rats, is coded accordingly to the three outcomes taken from the NTP tests, but the magnitude of potency depend completely upon our particular method of comparing toxicological data. We have attempted to demonstrate that a relative potency based analysis of a diversity of toxicological data may be useful for rank ordering potentially hazardous compounds to be tested by the NTP and for range-finding of their effective test doses to be administered during chronic test protocols. RP JONES, TD (reprint author), OAK RIDGE NATL LAB,DIV HLTH & SAFETY RES,OAK RIDGE,TN 37831, USA. NR 31 TC 20 Z9 20 U1 0 U2 0 PU OXFORD UNIV PRESS UNITED KINGDOM PI OXFORD PA WALTON ST JOURNALS DEPT, OXFORD, ENGLAND OX2 6DP SN 0267-8357 J9 MUTAGENESIS JI Mutagenesis PD NOV PY 1991 VL 6 IS 6 BP 507 EP 514 DI 10.1093/mutage/6.6.507 PG 8 WC Genetics & Heredity; Toxicology SC Genetics & Heredity; Toxicology GA GQ907 UT WOS:A1991GQ90700009 PM 1800899 ER PT J AU BAMBERGER, C BRYNESTAD, J AF BAMBERGER, C BRYNESTAD, J TI SYNTHESIS OF TITANIUM NITRIDE WHISKERS FROM POTASSIUM FLUOROTITANATE .4. COMMENT SO NIPPON SERAMIKKUSU KYOKAI GAKUJUTSU RONBUNSHI-JOURNAL OF THE CERAMIC SOCIETY OF JAPAN LA English DT Note RP BAMBERGER, C (reprint author), MAYTIN MARIETTA ENERGY SYST INC,OAK RIDGE NATL LAB,DIV CHEM,POB 2008,OAK RIDGE,TN 37831, USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU CERAMIC SOC JAPAN-NIPPON SERAMIKKUSU KYOKAI PI TOKYO PA 22-17 HYAKUNIN-CHO SHINJUKU-KU, TOKYO 169, JAPAN SN 0914-5400 J9 NIPPON SERAM KYO GAK PD NOV PY 1991 VL 99 IS 11 BP 1172 EP 1172 PG 1 WC Materials Science, Ceramics SC Materials Science GA GR272 UT WOS:A1991GR27200021 ER PT J AU MCPHERSON, DW LISIC, E KNAPP, FF AMBROSE, KR LAMBERT, CR KUNG, MP KUNG, H AF MCPHERSON, DW LISIC, E KNAPP, FF AMBROSE, KR LAMBERT, CR KUNG, MP KUNG, H TI SYNTHESIS AND EVALUATION OF 2 RADIOIODINATED IODOALKENYL-SUBSTITUTED SPIROPERIDOL ANALOGS SO NUC COMPACT-EUROPEAN-AMERICAN COMMUNICATIONS IN NUCLEAR MEDICINE LA English DT Article DE RADIOIODINE; DOPAMINE RECEPTOR; SPIROPERIDOL; IODODESTANNYLATION AB The (E)-3-N-(1-iodo-1-propen-3-yl) (11) and (E)-3-N-(1-iodo-1-penten-5-yl) (12) substituted analogues of spiroperidol have been prepared via iododestannylation of the corresponding tributylstannyl intermediates. No-carrier-added iodine-125-labeled analogues of 11 and 12 were also prepared and evaluated invivo for dopamine D2 receptor uptake. In vivo studies in male mice showed a higher global brain uptake for 11 (0.13% dose/g) as compared to the uptake of 12 (0.05 dose/g) after 300 min. 11 also showed a higher striatum to cerebellum ratio as compared to 12 after 300 min. RP MCPHERSON, DW (reprint author), OAK RIDGE NATL LAB,NUCL MED GRP,POB 2008,OAK RIDGE,TN 37831, USA. NR 0 TC 1 Z9 1 U1 0 U2 0 PU G-I-T VERLAG ERNST GIEBELER PI 6100 DARMSTADT 11 PA ROBLERSTRABE 90 POSTFACH 11 05 64, W-6100 6100 DARMSTADT 11, GERMANY SN 0344-3752 J9 NUC COMPACT PD NOV PY 1991 VL 22 IS 3 BP 92 EP 98 PG 7 WC Radiology, Nuclear Medicine & Medical Imaging SC Radiology, Nuclear Medicine & Medical Imaging GA JX535 UT WOS:A1991JX53500003 ER PT J AU PARKS, MB AF PARKS, MB TI LEAKAGE BEHAVIOR OF INFLATABLE SEALS SUBJECT TO SEVERE ACCIDENT CONDITIONS SO NUCLEAR ENGINEERING AND DESIGN LA English DT Article AB The paper describes tests to determine the leakage behavior of inflatable seals when subjected to containment pressures that exceed the design basis. 2 Inflatable seals are used to prevent leakage around personnel and escape lock doors in about 10% of the commercial nuclear power plant containment structures in the United States. All of the installations are in either Pressurized Water Reactor (PWR) or Boiling Water Reactor (BWR) Mark-Ill type containments. This work is a part of an overall effort at Sandia National Laboratories to develop proven techniques for evaluating the performance of Light Water Reactor (LWR) containment buildings for beyond design basis loadings. Inflatable seals were tested at both room temperature and at elevated temperatures representative of postulated severe accident conditions. Parameters that were monitored and recorded during each test were the internal seal pressure and temperature, chamber (containment) pressure, leakage past the seals, and temperature of the test chamber and fixture to which the seals were attached. An empirically based, analytical method is presented to predict the containment pressure at which significant leakage past inflatable seals can be expected. RP PARKS, MB (reprint author), SANDIA NATL LABS,DIV CONTAINMENT TECHNOL,POB 5800,ALBUQUERQUE,NM 87185, USA. NR 11 TC 0 Z9 0 U1 1 U2 2 PU ELSEVIER SCIENCE SA LAUSANNE PI LAUSANNE 1 PA PO BOX 564, 1001 LAUSANNE 1, SWITZERLAND SN 0029-5493 J9 NUCL ENG DES JI Nucl. Eng. Des. PD NOV PY 1991 VL 131 IS 2 BP 175 EP 186 DI 10.1016/0029-5493(91)90277-O PG 12 WC Nuclear Science & Technology SC Nuclear Science & Technology GA GW513 UT WOS:A1991GW51300005 ER PT J AU KELLY, DL AF KELLY, DL TI OVERVIEW OF CONTAINMENT VENTING AS AN ACCIDENT MITIGATION STRATEGY IN UNITED-STATES LIGHT WATER-REACTORS SO NUCLEAR ENGINEERING AND DESIGN LA English DT Review AB This paper summarizes the results of previous analyses of containment venting at US light water reactors. The focus of the paper is on the risk aspects of containment venting as a severe accident mitigation strategy; therefore, past risk analyses of venting are critically reviewed and conclusions are drawn where possible concerning the risk and efficacy of this strategy. Because the accident mitigation issues vary from one reactor and containment type to another, the paper examines five containment types separately. RP KELLY, DL (reprint author), EG&G IDAHO INC,IDAHO NATL ENGN LAB,POB 1625,IDAHO FALLS,ID 83415, USA. NR 20 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 0029-5493 J9 NUCL ENG DES JI Nucl. Eng. Des. PD NOV PY 1991 VL 131 IS 2 BP 253 EP 261 DI 10.1016/0029-5493(91)90283-N PG 9 WC Nuclear Science & Technology SC Nuclear Science & Technology GA GW513 UT WOS:A1991GW51300011 ER PT J AU MAYO, RM FERNANDEZ, JC HENINS, I KIRSCHENBAUM, LS MUNSON, CP WYSOCKI, FJ AF MAYO, RM FERNANDEZ, JC HENINS, I KIRSCHENBAUM, LS MUNSON, CP WYSOCKI, FJ TI TIME OF FLIGHT MEASUREMENT OF ION TEMPERATURES IN SPHEROMAKS SO NUCLEAR FUSION LA English DT Article ID MAGNETIZED PLASMA SOURCE; MESH FLUX CONSERVERS; ENERGY CONFINEMENT; S-1 SPHEROMAK; SUSTAINMENT; RELAXATION; BALANCE AB The energy distribution of neutral particles is detected from spheromak plasmas by a time of flight neutral atom spectrometer. These particles originate in charge exchange interactions within the bulk plasma and carry the temperature of the majority ion component. This is the first direct measurement of temperatures of the main ion species in spheromaks. The data are found to be in the range of 500 eV during the sustainment and late decay phases and are in agreement with impurity Doppler temperatures for species expected to be localized to the plasma centre. C1 UNIV CALIF LOS ALAMOS SCI LAB,LOS ALAMOS,NM 87544. RI Fernandez, Juan/H-3268-2011 OI Fernandez, Juan/0000-0002-1438-1815 NR 26 TC 12 Z9 12 U1 0 U2 1 PU INT ATOMIC ENERGY AGENCY PI VIENNA PA WAGRAMERSTRASSE 5 PO BOX 100, A-1400 VIENNA, AUSTRIA SN 0029-5515 J9 NUCL FUSION JI Nucl. Fusion PD NOV PY 1991 VL 31 IS 11 BP 2087 EP 2095 DI 10.1088/0029-5515/31/11/005 PG 9 WC Physics, Fluids & Plasmas SC Physics GA GP730 UT WOS:A1991GP73000005 ER PT J AU FIDONE, I GRANATA, G GIRUZZI, G MAZZUCATO, E AF FIDONE, I GRANATA, G GIRUZZI, G MAZZUCATO, E TI SYNCHROTRON RADIATION LOSS IN A TOKAMAK REACTOR IN THE PRESENCE OF AN ENHANCED ELECTRON TAIL SO NUCLEAR FUSION LA English DT Letter ID CYCLOTRON EMISSION AB The role of an enhanced electron tail on the emission and absorption of synchrotron radiation in a tokamak reactor is investigated. It is shown that the radiofrequency power loss at omega much greater than omega(c) in a Maxwellian plasma is radiated by electrons with velocities significantly higher than the thermal velocity. Therefore, the synchrotron radiation loss will be enhanced when the tail distribution develops a superthermal feature. The enhanced loss with respect to Trubnikov's result has been computed for a homogeneous plasma. C1 PRINCETON UNIV,PLASMA PHYS LAB,PRINCETON,NJ 08543. RP FIDONE, I (reprint author), ASSOC EURATOM CEA FUS,CTR ETUD NUCL CADARACHE,DEPT RECH FUS CONTROLEE,ST PAUL DURANCE,FRANCE. NR 10 TC 2 Z9 2 U1 1 U2 2 PU INT ATOMIC ENERGY AGENCY PI VIENNA PA WAGRAMERSTRASSE 5 PO BOX 100, A-1400 VIENNA, AUSTRIA SN 0029-5515 J9 NUCL FUSION JI Nucl. Fusion PD NOV PY 1991 VL 31 IS 11 BP 2167 EP 2171 DI 10.1088/0029-5515/31/11/015 PG 5 WC Physics, Fluids & Plasmas SC Physics GA GP730 UT WOS:A1991GP73000015 ER PT J AU HOGAN, JT HILLIS, DL AF HOGAN, JT HILLIS, DL TI HELIUM TRANSPORT AND EXHAUST IN TOKAMAKS - REPORT ON THE INTERNATIONAL WORKSHOP ON HELIUM TRANSPORT AND EXHAUST EXPERIMENTS HELD AT GATLINBURG, TENNESSEE, UNITED-STATES-OF-AMERICA, 16-18 APRIL 1991 SO NUCLEAR FUSION LA English DT Editorial Material RP HOGAN, JT (reprint author), OAK RIDGE NATL LAB,DIV FUS ENERGY,OAK RIDGE,TN, USA. NR 0 TC 7 Z9 7 U1 0 U2 0 PU INT ATOMIC ENERGY AGENCY PI VIENNA PA WAGRAMERSTRASSE 5 PO BOX 100, A-1400 VIENNA, AUSTRIA SN 0029-5515 J9 NUCL FUSION JI Nucl. Fusion PD NOV PY 1991 VL 31 IS 11 BP 2181 EP 2191 DI 10.1088/0029-5515/31/11/017 PG 11 WC Physics, Fluids & Plasmas SC Physics GA GP730 UT WOS:A1991GP73000017 ER PT J AU JOB, PK PRICE, L PROUDFOOT, J HANDLER, T BISHOP, BL GABRIEL, TA AF JOB, PK PRICE, L PROUDFOOT, J HANDLER, T BISHOP, BL GABRIEL, TA TI COMPARISON OF CALOR89 MODEL PREDICTIONS WITH SCINTILLATOR PLATE CALORIMETER DATA SO NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH SECTION A-ACCELERATORS SPECTROMETERS DETECTORS AND ASSOCIATED EQUIPMENT LA English DT Article ID ENERGY TRANSPORT CODE; HADRON CALORIMETERS; URANIUM; RESOLUTION AB The CALOR code system has been recently revised by adding a high energy collision model for energies greater-than-or-equal-to 5 GeV. This version is called as CALOR89. Calculations with this version have been carried out and compared with experimental data from four test beam scintillator plate calorimeter configurations. The agreement is good within the systematics. The limiting uncertainty in CALOR simulation at 10 GeV is the choice of collision model. We have addressed this uncertainty by appealing to the experimental data and determined that by a careful transition from the Intranuclear Cascade model to the FLUKA model this can be reduced to 1.5%. The other mostly mechanical effects such as cladding, scintillator saturation, shower integration time and shower containment can each produce systematic shifts as much as 4%. However, careful modeling of the experimental configuration should allow the systematic effects from each of these to be minimised to 1%. We find that an overall systematic uncertainty of 2.5% in the model predictions may then be achieved. C1 UNIV TENNESSEE,KNOXVILLE,TN 37996. OAK RIDGE NATL LAB,OAK RIDGE,TN 37831. RP JOB, PK (reprint author), ARGONNE NATL LAB,ARGONNE,IL 60439, USA. NR 23 TC 5 Z9 5 U1 0 U2 0 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0168-9002 J9 NUCL INSTRUM METH A JI Nucl. Instrum. Methods Phys. Res. Sect. A-Accel. Spectrom. Dect. Assoc. Equip. PD NOV 1 PY 1991 VL 309 IS 1-2 BP 60 EP 68 DI 10.1016/0168-9002(91)90092-5 PG 9 WC Instruments & Instrumentation; Nuclear Science & Technology; Physics, Nuclear; Physics, Particles & Fields SC Instruments & Instrumentation; Nuclear Science & Technology; Physics GA GN654 UT WOS:A1991GN65400009 ER PT J AU ANDERSON, DF AMOS, NA AF ANDERSON, DF AMOS, NA TI PROSPECTS FOR USING PHOTOSENSITIVE DOPANTS TO IMPROVE THE E/PI RATIO OF LIQUID ARGON CALORIMETERS SO NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH SECTION A-ACCELERATORS SPECTROMETERS DETECTORS AND ASSOCIATED EQUIPMENT LA English DT Article ID IONIZATION; XENON; PHOTOIONIZATION; TRIMETHYLAMINE; TRIETHYLAMINE; LUMINESCENCE AB There is evidence that shows that heavily ionizing interactions contribute to the signal from hadrons in liquid argon calorimeters, and that saturation effects play an important role in the e/pi-ratio. Measurements and calculations are presented which indicate a substantial improvement can be made to the e/pi-ratio by the addition of a few ppm of photosensitive dopants. RP ANDERSON, DF (reprint author), FERMI NATL ACCELERATOR LAB,PARTICLE DETECTOR GRP,BATAVIA,IL 60510, USA. NR 24 TC 7 Z9 7 U1 0 U2 0 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0168-9002 J9 NUCL INSTRUM METH A JI Nucl. Instrum. Methods Phys. Res. Sect. A-Accel. Spectrom. Dect. Assoc. Equip. PD NOV 1 PY 1991 VL 309 IS 1-2 BP 69 EP 76 DI 10.1016/0168-9002(91)90093-6 PG 8 WC Instruments & Instrumentation; Nuclear Science & Technology; Physics, Nuclear; Physics, Particles & Fields SC Instruments & Instrumentation; Nuclear Science & Technology; Physics GA GN654 UT WOS:A1991GN65400010 ER PT J AU DERRICK, M GACEK, D HILL, N MUSGRAVE, B NOLAND, R PETEREIT, E REPOND, J STANEK, R SUGANO, K AF DERRICK, M GACEK, D HILL, N MUSGRAVE, B NOLAND, R PETEREIT, E REPOND, J STANEK, R SUGANO, K TI DESIGN AND CONSTRUCTION OF THE ZEUS BARREL CALORIMETER SO NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH SECTION A-ACCELERATORS SPECTROMETERS DETECTORS AND ASSOCIATED EQUIPMENT LA English DT Article ID MONTE-CARLO; URANIUM AB We present the mechanical design and construction techniques used in building the barrel calorimeter for the ZEUS detector. The latter is currently under construction for use at the HERA electron-proton colliding beam facility. The calorimeter consists of 32 wedge shaped modules with approximate dimensions of 3 x 0.5 x 1.7 m3. The modules use alternate layers of depleted uranium and scintillator with one radiation length sampling. The light is collected via wavelength shifter plates placed on the sloping sides of the modules and read out by photomultiplier tubes located at the outer radius. The unit cell dimensions result in a ratio e/h = 1 which yields an optimal energy resolution for hadronic jets. The placing of the structural components and the arrangement of the cracks between modules were chosen to maximize the uniformity of the response. Details of the construction and assembly effort needed to realize the total calorimeter are given. We finally describe the procedures used for transporting the completed modules to DESY and to install them on ZEUS. RP DERRICK, M (reprint author), ARGONNE NATL LAB,ARGONNE,IL 60439, USA. NR 24 TC 223 Z9 223 U1 0 U2 2 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0168-9002 J9 NUCL INSTRUM METH A JI Nucl. Instrum. Methods Phys. Res. Sect. A-Accel. Spectrom. Dect. Assoc. Equip. PD NOV 1 PY 1991 VL 309 IS 1-2 BP 77 EP 100 DI 10.1016/0168-9002(91)90094-7 PG 24 WC Instruments & Instrumentation; Nuclear Science & Technology; Physics, Nuclear; Physics, Particles & Fields SC Instruments & Instrumentation; Nuclear Science & Technology; Physics GA GN654 UT WOS:A1991GN65400011 ER PT J AU ANDRESEN, A BAMBERGER, A BARGENDE, A BARREIRO, F BEHRENS, U BENTVELSEN, S BRKIC, M BUROW, B CALDWELL, A CASES, G CORRIVEAU, F CRITTENDEN, JA DAKE, A DANNEMANN, A DAWSON, J DIERKS, K DREWS, G ENGELEN, J FAWCETT, H FRISKEN, W FURTJES, A GILKINSON, D HAGGE, L HAMATSU, R HANNA, D HARTMANN, J HASEGAWA, T HASELL, D HAZUMI, M HERVAS, L HILGER, E HOLM, U ISHII, T DEJONG, P KAMMERLOCHER, H KASAI, S KITAMURA, S KLANNER, R KOOIJMAN, P KOTZ, U KRAMER, M KREBS, B KROGER, W KRUGER, J KUZE, M LEVMAN, G LINDENBERG, T MARTIN, J MAYER, J VANDERLUGT, H MITCHELL, J PATEL, P POSER, T PRANGE, K RITZ, S ROHDE, M ROMANOWSKI, T ROS, E SCHNEIDER, HL SCHACKE, D SCHULZ, W SELONKE, F SIPPACH, W SMITH, G STAIRS, G STRAVER, J THEISEN, G TIECKE, H TOKUSHUKU, K TRONDLE, B TSURUGAI, T UIJTERWAAL, H ULLMANN, R VOGEL, W WICK, K WOENIGER, T YAMADA, S YOUNGMAN, C AF ANDRESEN, A BAMBERGER, A BARGENDE, A BARREIRO, F BEHRENS, U BENTVELSEN, S BRKIC, M BUROW, B CALDWELL, A CASES, G CORRIVEAU, F CRITTENDEN, JA DAKE, A DANNEMANN, A DAWSON, J DIERKS, K DREWS, G ENGELEN, J FAWCETT, H FRISKEN, W FURTJES, A GILKINSON, D HAGGE, L HAMATSU, R HANNA, D HARTMANN, J HASEGAWA, T HASELL, D HAZUMI, M HERVAS, L HILGER, E HOLM, U ISHII, T DEJONG, P KAMMERLOCHER, H KASAI, S KITAMURA, S KLANNER, R KOOIJMAN, P KOTZ, U KRAMER, M KREBS, B KROGER, W KRUGER, J KUZE, M LEVMAN, G LINDENBERG, T MARTIN, J MAYER, J VANDERLUGT, H MITCHELL, J PATEL, P POSER, T PRANGE, K RITZ, S ROHDE, M ROMANOWSKI, T ROS, E SCHNEIDER, HL SCHACKE, D SCHULZ, W SELONKE, F SIPPACH, W SMITH, G STAIRS, G STRAVER, J THEISEN, G TIECKE, H TOKUSHUKU, K TRONDLE, B TSURUGAI, T UIJTERWAAL, H ULLMANN, R VOGEL, W WICK, K WOENIGER, T YAMADA, S YOUNGMAN, C TI CONSTRUCTION AND BEAM TEST OF THE ZEUS FORWARD AND REAR CALORIMETER SO NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH SECTION A-ACCELERATORS SPECTROMETERS DETECTORS AND ASSOCIATED EQUIPMENT LA English DT Article ID SCINTILLATOR CALORIMETER; URANIUM; RESOLUTION; PROTOTYPE AB The forward and rear calorimeters of the ZEUS experiment are made of 48 modules with maximum active dimensions of 4.6 m height, 0.2 m width, 7-lambda-depth and maximum weight of 12 t. It consists of 1 X0 uranium plates interleaved with plastic scintillator tiles read out via wavelength shifters and photomultipliers. The mechanical construction, the achieved tolerances as well as the optical and electronics readout are described. Ten of these modules have been tested with electrons, hadrons and muons in the momentum range 15-100 GeV/c. Results on resolution, uniformity and calibration are presented. Our main result is the achieved calibration accuracy of about 1% obtained by using the signal from the uranium radioactivity. C1 UNIV FREIBURG,W-7800 FREIBURG,GERMANY. UNIV BONN,W-5300 BONN,GERMANY. UNIV AUTONOMA MADRID,MADRID 34,SPAIN. UNIV HAMBURG,INST EXPT PHYS 1,W-2000 HAMBURG 13,GERMANY. NATL INST NUCL PHYS & HIGH ENERGY PHYS,AMSTERDAM,NETHERLANDS. UNIV TORONTO,TORONTO M5S 1A1,ONTARIO,CANADA. COLUMBIA UNIV,NEW YORK,NY 10027. ARGONNE NATL LAB,ARGONNE,IL 60439. DESY,W-2000 HAMBURG 52,GERMANY. YORK UNIV,N YORK M3J 1P3,ONTARIO,CANADA. MCGILL UNIV,MONTREAL H3A 2T5,QUEBEC,CANADA. TOKYO METROPOLITAN UNIV,TOKYO 158,JAPAN. UNIV TOKYO,INS,TOKYO 113,JAPAN. OHIO STATE UNIV,COLUMBUS,OH 43210. UNIV MANITOBA,WINNIPEG R3T 2N2,MANITOBA,CANADA. RP ANDRESEN, A (reprint author), UNIV HAMBURG,INST EXPTL PHYS 2,W-2000 HAMBURG 13,GERMANY. NR 46 TC 255 Z9 255 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 NOV 1 PY 1991 VL 309 IS 1-2 BP 101 EP 142 DI 10.1016/0168-9002(91)90095-8 PG 42 WC Instruments & Instrumentation; Nuclear Science & Technology; Physics, Nuclear; Physics, Particles & Fields SC Instruments & Instrumentation; Nuclear Science & Technology; Physics GA GN654 UT WOS:A1991GN65400012 ER PT J AU CHRISTOPHOROU, LG DATSKOS, PG CARTER, JG AF CHRISTOPHOROU, LG DATSKOS, PG CARTER, JG TI GASES OF POSSIBLE INTEREST TO SSC MUON DETECTORS SO NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH SECTION A-ACCELERATORS SPECTROMETERS DETECTORS AND ASSOCIATED EQUIPMENT LA English DT Article ID SCATTERING CROSS-SECTIONS; ELECTRON-ATTACHMENT; MIXTURES; DRIFT; ETHANE; ARGON; CF4 AB We have been exploring the development of multicomponent gas mixtures with optimal electron transport, gain, electrical and chemical properties of potential interest to the Superconducting Super Collider muon detectors focusing in particular on binary and ternary mixtures of Ar, N2, CO, CO2, CH4, CF4, NH3, and H2O. In this article, we report and discuss: (i) recent measurements of electron drift velocities as a function of the density-reduced electric field E/N for CO2/CF4, CO2/CH4, CO2/N2, CO/Ar, Ar/Si(CH3)4, NH3/CF4/Ar, CO2/CF4/Ar, and H2O/CF4/Ar mixtures, (ii) calculated values of the mean electron energy as a function of E/N for a number of unitary gases and the gas mixtures CO2/CF4, CO2/CH4, and CF4/Ar, and (iii) effective ionization coefficients as a function of E/N for Ar/CF4, Ar/CO2, CO2/CH4, and mixtures of Ar/CF4 containing CO2 or H2O. Addition of CO2 or H2O or NH3 to CF4/Ar causes electron "cooling" and increases the electron yield; the addition of H2O (or NH3) may, also, improve the detector aging performance. Mixtures of Ar/CF4 with CO2 or H2O appear promising. All results reported are for the case of zero magnetic field. C1 UNIV TENNESSEE,KNOXVILLE,TN 37996. RP CHRISTOPHOROU, LG (reprint author), OAK RIDGE NATL LAB,HLTH & SAFETY RES GRP,ATOM MOLEC & HIGH VOLTAGE PHYS GRP,OAK RIDGE,TN 37831, USA. NR 39 TC 25 Z9 25 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 NOV 1 PY 1991 VL 309 IS 1-2 BP 160 EP 168 DI 10.1016/0168-9002(91)90097-A PG 9 WC Instruments & Instrumentation; Nuclear Science & Technology; Physics, Nuclear; Physics, Particles & Fields SC Instruments & Instrumentation; Nuclear Science & Technology; Physics GA GN654 UT WOS:A1991GN65400014 ER PT J AU KWAN, S ANDERSON, DF AF KWAN, S ANDERSON, DF TI A STUDY OF THE CSI-TMAE PHOTOCATHODE SO NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH SECTION A-ACCELERATORS SPECTROMETERS DETECTORS AND ASSOCIATED EQUIPMENT LA English DT Article ID SOLID ORGANIC PHOTOCATHODES; PRESSURE WIRE CHAMBER; PHOTO-CATHODE; LIQUID; EFFICIENCY; EXTRACTION; ELECTRONS; DETECTOR; GAS AB The quantum efficiency of a CsI-TMAE photocathode has been found to increase by over a factor of 2 under bombardment of positive ions from the avalanche process. A quantum efficiency of about 40% has been achieved for wavelengths less-than-or-equal-to 190 nm. This "enhancement" can be removed by an electrical discharge or by a brief exposure to a vacuum. Results on photocathode ageing are also presented. RP KWAN, S (reprint author), FERMI NATL ACCELERATOR LAB,PARTICLE DETECTOR GRP,BATAVIA,IL 60510, USA. NR 18 TC 22 Z9 22 U1 0 U2 1 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0168-9002 J9 NUCL INSTRUM METH A JI Nucl. Instrum. Methods Phys. Res. Sect. A-Accel. Spectrom. Dect. Assoc. Equip. PD NOV 1 PY 1991 VL 309 IS 1-2 BP 190 EP 195 DI 10.1016/0168-9002(91)90101-U PG 6 WC Instruments & Instrumentation; Nuclear Science & Technology; Physics, Nuclear; Physics, Particles & Fields SC Instruments & Instrumentation; Nuclear Science & Technology; Physics GA GN654 UT WOS:A1991GN65400018 ER PT J AU GAGGELER, HW JOST, DT BALTENSPERGER, U WEBER, A KOVACS, A VERMEULEN, D TURLER, A AF GAGGELER, HW JOST, DT BALTENSPERGER, U WEBER, A KOVACS, A VERMEULEN, D TURLER, A TI OLGA-II, AN ONLINE GAS CHEMISTRY APPARATUS FOR APPLICATIONS IN HEAVY ELEMENT RESEARCH SO NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH SECTION A-ACCELERATORS SPECTROMETERS DETECTORS AND ASSOCIATED EQUIPMENT LA English DT Article ID PRODUCE SUPERHEAVY ELEMENTS; BOMBARDING ENERGY-RANGE; FUSION; SEPARATION; CM-248; CA-48; MEV/U AB OLGA II is a device which performs on-line gas phase separations of volatile compounds of atoms produced in nuclear reactions. Reaction products are attached to aerosol particles and transported in a gas-jet to a heated quartz column and stopped in a quartz wool plug kept at 900 to 1000-degrees-C. Volatile compounds are formed by the addition of reactive gases. The volatile compounds are transported along a cooler, isothermal part of the column by the gas flow. The retention time in the isothermal part of the column is related to the enthalpies of adsorption of the compounds on the quartz surface. Separated atoms leaving the column are attached to new aerosol particles and transported through a second gas-jet to a detection system. This apparatus consists of a modified tape system. In a first collecting chamber the products are deposited on the surface of a stepwise moving tape. At preset times the deposited activity is moved past a series of six counting chambers equipped with charged particle or high-purity germanium detectors for alpha, spontaneous-fission, X- and gamma-ray counting. Data acquisition is performed event-by-event which allows to detect also correlated events. The system can be used for nuclides with half-lives longer than about 10 s. Correlated events can be resolved for times greater-than-or-equal-to 150-mu-s between consecutive decays. C1 UNIV CALIF BERKELEY,LAWRENCE BERKELEY LAB,BERKELEY,CA 94720. RP GAGGELER, HW (reprint author), PAUL SCHERRER INST,CH-5232 VILLIGEN,SWITZERLAND. RI Turler, Andreas/D-3913-2014 OI Turler, Andreas/0000-0002-4274-1056 NR 34 TC 54 Z9 56 U1 0 U2 2 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0168-9002 J9 NUCL INSTRUM METH A JI Nucl. Instrum. Methods Phys. Res. Sect. A-Accel. Spectrom. Dect. Assoc. Equip. PD NOV 1 PY 1991 VL 309 IS 1-2 BP 201 EP 208 DI 10.1016/0168-9002(91)90103-W PG 8 WC Instruments & Instrumentation; Nuclear Science & Technology; Physics, Nuclear; Physics, Particles & Fields SC Instruments & Instrumentation; Nuclear Science & Technology; Physics GA GN654 UT WOS:A1991GN65400020 ER PT J AU ERCK, RA REHN, LE AF ERCK, RA REHN, LE TI CORRECTION OF ENERGY SHIFT DURING RBS DATA-ANALYSIS - APPLICATION TO STUDY OF SOLUTE SEGREGATION IN MO-RE ALLOYS SO NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH SECTION B-BEAM INTERACTIONS WITH MATERIALS AND ATOMS LA English DT Article AB Rutherford backscattering spectrometry (RBS) is often used to measure the elemental composition of the near-surface region of a specimen. During data acquisition, small shifts in energy calibration can occur, introducing errors in the data. Such shifts were experienced during measurements of radiation-induced solute segregation in molybdenum-rhenium alloys where segregation of Re atoms toward the external surface was measured during irradiation by in situ RBS. The resulting edge shifts in the spectra produced spurious contributions near the elemental leading edges significantly affecting the measured segregation. A simple method is proposed for correcting errors due to energy shift, and applied to these segregation measurements. C1 ARGONNE NATL LAB,DIV MAT SCI,ARGONNE,IL 60439. RP ERCK, RA (reprint author), ARGONNE NATL LAB,DIV MAT & COMPONENTS TECHNOL,ARGONNE,IL 60439, USA. NR 3 TC 1 Z9 1 U1 0 U2 2 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0168-583X J9 NUCL INSTRUM METH B JI Nucl. Instrum. Methods Phys. Res. Sect. B-Beam Interact. Mater. Atoms PD NOV PY 1991 VL 62 IS 1 BP 143 EP 146 DI 10.1016/0168-583X(91)95940-F PG 4 WC Instruments & Instrumentation; Nuclear Science & Technology; Physics, Atomic, Molecular & Chemical; Physics, Nuclear SC Instruments & Instrumentation; Nuclear Science & Technology; Physics GA GU719 UT WOS:A1991GU71900020 ER PT J AU KHALIL, HS HILL, RN AF KHALIL, HS HILL, RN TI EVALUATION OF LIQUID-METAL REACTOR DESIGN OPTIONS FOR REDUCTION OF SODIUM VOID WORTH SO NUCLEAR SCIENCE AND ENGINEERING LA English DT Article AB Systematic analyses of alternative methods for reducing the sodium void worth for plutonium-fueled liquid-metal reactors (LMRs) have been performed. The focus is on core designs of recent interest in the U.S. LMR program, i.e., designs in the 450- to 1200-MW(thermal) size range that make use of metal alloy fuel. The design alternatives encompass changes in composition and geometry. An internally consistent and comprehensive evaluation is made of the void worth reduction achievable by various methods and of the associated core physics performance trade-offs. The performance penalties (e.g., the reduced breeding efficiency and the increases in burnup reactivity loss and fissile mass requirement) caused by design changes that significantly reduce the void worth are quantified, and the relative merits of each design option are assessed. The results indicate that the penalties in burnup reactivity loss and fissile requirement can be minimized by use of a "tightly coupled" radially heterogeneous configuration of minimum volume consistent with fuel rating limits and by adjusting the core height-to-diameter ratio to a value sufficiently small to yield an acceptable void worth. The reactor breeding ratio penalty, however, is minimized by the use of loosely coupled heterogeneous cores or annular cores with a large central blanket zone. Penalties in core radius and volume can be minimized by core composition changes, specifically by replacing a fraction of the fuel (or steel) with sodium or a moderating material. RP KHALIL, HS (reprint author), ARGONNE NATL LAB,DIV REACTOR ANAL,ARGONNE,IL 60439, USA. NR 37 TC 21 Z9 22 U1 0 U2 1 PU AMER NUCLEAR SOCIETY PI LA GRANGE PK PA 555 N KENSINGTON AVENUE, LA GRANGE PK, IL 60525 SN 0029-5639 J9 NUCL SCI ENG JI Nucl. Sci. Eng. PD NOV PY 1991 VL 109 IS 3 BP 221 EP 266 PG 46 WC Nuclear Science & Technology SC Nuclear Science & Technology GA GN080 UT WOS:A1991GN08000001 ER PT J AU SAILOR, WC BYRD, RC GAVRON, A HAMMOCK, R YARIV, Y AF SAILOR, WC BYRD, RC GAVRON, A HAMMOCK, R YARIV, Y TI A NEUTRON SOURCE IMAGING DETECTOR FOR NUCLEAR ARMS TREATY VERIFICATION SO NUCLEAR SCIENCE AND ENGINEERING LA English DT Article ID SCINTILLATION-COUNTERS AB A detector design that is capable of finding the image of neutron sources within a nuclear missile is discussed. The method involves the double scatter of a neutron in an array of organic scintillator elements and the partial reconstruction of the incident neutron direction vector from the information the array provides. The Monte Carlo simulation results for a basic design and several modifications are presented. The results of an experimental demonstration of the technique using a crude prototype detector are given. Problems expected in a real application are discussed. C1 SOREQ NUCL RES CTR,IL-70600 YAVNE,ISRAEL. RP SAILOR, WC (reprint author), UNIV CALIF LOS ALAMOS SCI LAB,LOS ALAMOS,NM 87545, USA. NR 14 TC 6 Z9 6 U1 0 U2 1 PU AMER NUCLEAR SOCIETY PI LA GRANGE PK PA 555 N KENSINGTON AVENUE, LA GRANGE PK, IL 60525 SN 0029-5639 J9 NUCL SCI ENG JI Nucl. Sci. Eng. PD NOV PY 1991 VL 109 IS 3 BP 267 EP 277 PG 11 WC Nuclear Science & Technology SC Nuclear Science & Technology GA GN080 UT WOS:A1991GN08000002 ER PT J AU DOWNAR, TJ KHALIL, H AF DOWNAR, TJ KHALIL, H TI UNCERTAINTY IN THE BURNUP REACTIVITY SWING OF LIQUID-METAL FAST-REACTORS SO NUCLEAR SCIENCE AND ENGINEERING LA English DT Article ID FAST BREEDER REACTOR; GENERALIZED PERTURBATION-THEORY; SENSITIVITY ANALYSIS; DEPLETION; PREDICTION; ERROR AB The uncertainty in the burnup reactivity swing delta-k(b) attributable to nuclear data uncertainties is analyzed using depletion-dependent sensitivity coefficients for single- and multicycle equilibrium depletion. Four systems are analyzed with design features that encompass many of the design options considered for current U.S. advanced liquid-metal reactor cores. These systems, while characterized by very different delta-k(b) values in the range from -0.22 to 3.87% DELTA-k, exhibit much smaller differences in their delta-k(b) uncertainties, which range from 0.18 to 0.33% DELTA-k. The delta-k(b) uncertainties depend primarily on the design choices of core size and fissile fuel type, as well as whether the analysis represents multicycle effects. For all reactors analyzed, the burnup swing uncertainty is dominated by the U-238 capture reaction. The potential for reducing uncertainties by a factor of 3 by use of available integral experiment results is also demonstrated. C1 ARGONNE NATL LAB,ARGONNE,IL 60439. RP DOWNAR, TJ (reprint author), PURDUE UNIV,SCH NUCL ENGN,W LAFAYETTE,IN 47907, USA. NR 24 TC 3 Z9 3 U1 0 U2 1 PU AMER NUCLEAR SOCIETY PI LA GRANGE PK PA 555 N KENSINGTON AVENUE, LA GRANGE PK, IL 60525 SN 0029-5639 J9 NUCL SCI ENG JI Nucl. Sci. Eng. PD NOV PY 1991 VL 109 IS 3 BP 278 EP 296 PG 19 WC Nuclear Science & Technology SC Nuclear Science & Technology GA GN080 UT WOS:A1991GN08000003 ER PT J AU WANG, OS COLES, GA KELLY, JE POWERS, TB RAINEY, TE ZENTNER, MD WYSS, GD KUNSMAN, DM MILLER, LA WHEELER, TA SPRUNG, JL CAMP, AL AF WANG, OS COLES, GA KELLY, JE POWERS, TB RAINEY, TE ZENTNER, MD WYSS, GD KUNSMAN, DM MILLER, LA WHEELER, TA SPRUNG, JL CAMP, AL TI N-REACTOR LEVEL-III PROBABILISTIC RISK ASSESSMENT USING NUREG-1150 METHODS SO NUCLEAR TECHNOLOGY LA English DT Article DE N-REACTOR; PROBABILISTIC RISK ASSESSMENT; NUREG-1150 AB In the late 1980s, a level III probabilistic risk assessment (PRA) was performed for the N Reactor, a U.S. Department of Energy (DOE) production reactor located on the Hanford site in Washington State. The PRA objectives were to assess the risks to the public and to the Hanford on-site workers posed by the operation of the N Reactor, to compare those risks to proposed DOE nuclear safety guidelines, and to identify risk-reduction changes to the plant. State-of-the-art methodology was employed based largely on the methods developed by Sandia National Laboratories for the U.S. Nuclear Regulatory Commission in support of the NUREG-1150 study of five commercial nuclear power plants. The structure of the probabilistic models allowed complex interactions and dependencies between systems to be explicitly considered. Latin hypercube sampling techniques were used to develop uncertainty distributions for the risks associated with postulated core damage events initiated by fire, seismic, and internal events as well as the overall combined risk. The risk results show that the N Reactor meets the proposed DOE nuclear safety guidelines and compares favorably to the commercial nuclear power plants considered in the NUREG-1150 analysis. C1 SANDIA NATL LABS,ALBUQUERQUE,NM 87185. RP WANG, OS (reprint author), WESTINGHOUSE HANFORD CO,RISK ASSESSMENT TECHNOL,POB 1970,RICHLAND,WA 99352, USA. NR 20 TC 0 Z9 0 U1 0 U2 1 PU AMER NUCLEAR SOCIETY PI LA GRANGE PK PA 555 N KENSINGTON AVENUE, LA GRANGE PK, IL 60525 SN 0029-5450 J9 NUCL TECHNOL JI Nucl. Technol. PD NOV PY 1991 VL 96 IS 2 BP 147 EP 168 PG 22 WC Nuclear Science & Technology SC Nuclear Science & Technology GA GL670 UT WOS:A1991GL67000003 ER PT J AU BUELT, JL FARNSWORTH, RK AF BUELT, JL FARNSWORTH, RK TI INSITU VITRIFICATION OF SOILS CONTAINING VARIOUS METALS SO NUCLEAR TECHNOLOGY LA English DT Article DE VITRIFICATION; BURIED METALS; ELECTRODES AB In situ vitrification (ISV) converts contaminated soil into a glass and crystalline product by melting it with electrical energy. Pacific Northwest Laboratory, the developer of ISV, is currently conducting research to extend the technology to buried wastes and underground tanks for the U.S. Department of Energy. Since these types of wastes are anticipated to contain high concentrations of metals, new processing techniques are being developed and tested. In addition, the effects of metals on melt shape and on the solubility of heavy metals are being studied and tested. An electrode feeding technique has been developed and tested for processing high concentrations of metals. Instead of predrilling casings for electrode installation into the contaminated soil to be vitrified, electrode feeding allows the electrodes to be inserted as the vitrified soil melts downward. This concept has been successfully tested four times on engineering-scale equipment, which is 1/100th the capacity of large-scale equipment. Preliminary information has been collected on the influence of metals on melt on melt shape and on the solubility of heavy metals in the molten soil. Test results indicate that metals could be used to achieve greater depths with ISV. Also, although the presence of metals can cause heavy metals to reduce and alloy with the molten metal pool at the bottom of the vitrified soil, the metallic phase passes all criteria for product durability. Additional and larger scale testing is needed to confirm these conclusions. RP BUELT, JL (reprint author), PACIFIC NW LAB, POB 999, RICHLAND, WA 99352 USA. NR 11 TC 3 Z9 3 U1 2 U2 4 PU AMER NUCLEAR SOCIETY PI LA GRANGE PK PA 555 N KENSINGTON AVENUE, LA GRANGE PK, IL 60525 SN 0029-5450 J9 NUCL TECHNOL JI Nucl. Technol. PD NOV PY 1991 VL 96 IS 2 BP 178 EP 184 PG 7 WC Nuclear Science & Technology SC Nuclear Science & Technology GA GL670 UT WOS:A1991GL67000005 ER PT J AU FORSBERG, CW AF FORSBERG, CW TI A WATER LEVEL-INITIATED DECAY ENERGY COOLING SYSTEM SO NUCLEAR TECHNOLOGY LA English DT Article DE PASSIVE SAFETY; DECAY HEAT REMOVAL; EMERGENCY CORE COOLING SYSTEM ID REACTOR; PLANT AB A new passive safety system to remove reactor decay heat (energy) from water-cooled reactors has been developed. It consists of (a) a natural-circulation heat transfer subsystem to remove heat from the reactor coolant and dump it into the atmosphere and (b) a subsystem that triggers the heat transfer subsystem based on low water levels. The initiating mechanism relies on the difference in the physical properties of steam and liquid water. A preliminary description and performance analysis of the water level-initiated decay energy cooling system are provided. RP FORSBERG, CW (reprint author), OAK RIDGE NATL LAB,DEV LIGHT WATER REACTOR PROGRAM,OAK RIDGE,TN 37830, USA. NR 12 TC 1 Z9 1 U1 0 U2 0 PU AMER NUCLEAR SOCIETY PI LA GRANGE PK PA 555 N KENSINGTON AVENUE, LA GRANGE PK, IL 60525 SN 0029-5450 J9 NUCL TECHNOL JI Nucl. Technol. PD NOV PY 1991 VL 96 IS 2 BP 229 EP 235 PG 7 WC Nuclear Science & Technology SC Nuclear Science & Technology GA GL670 UT WOS:A1991GL67000010 ER PT J AU GALLAGHER, MA KELLY, EJ AF GALLAGHER, MA KELLY, EJ TI A NEW METHODOLOGY FOR MILITARY FORCE STRUCTURE-ANALYSIS SO OPERATIONS RESEARCH LA English DT Article DE MILITARY, COST EFFECTIVE, FORCE TRADEOFF ANALYSES; MILITARY, FORCE EFFECTIVENESS, CONVENTIONAL AND NUCLEAR FORCE CAPABILITY ASSESSMENT; MILITARY, TARGETING, GENERIC TARGETS FOR LARGE-SCALE CONVENTIONAL ANALYSIS AB A new methodology provides military decision makers with information on the aggregate effectiveness of large-scale conventional (nonnuclear) and combined nuclear and conventional force structures against a wide range of targets. This methodology coupled a generic data base of representative targets, to which real-world targets can be mapped, with a nuclear force-exchange model that uses goal programming techniques to determine optimal allocations of weapons to targets. This methodology enabled military strategists to analyze the effectiveness of existing and proposed weapon systems against a variety of targets and to study a number of force structures constrained by proposed force reduction treaties and tight defense budgets. C1 UNIV CALIF LOS ALAMOS SCI LAB,ENVIRONM RESTORAT PROGRAM,LOS ALAMOS,NM 87545. RP GALLAGHER, MA (reprint author), USAF,INST TECHNOL,WRIGHT PATTERSON AFB,OH 45433, USA. NR 5 TC 5 Z9 5 U1 3 U2 3 PU OPERATIONS RESEARCH SOC AMER PI LINTHICUM HTS PA 901 ELKRIDGE LANDING RD, STE 400, LINTHICUM HTS, MD 21090-2920 SN 0030-364X J9 OPER RES JI Oper. Res. PD NOV-DEC PY 1991 VL 39 IS 6 BP 877 EP 885 DI 10.1287/opre.39.6.877 PG 9 WC Management; Operations Research & Management Science SC Business & Economics; Operations Research & Management Science GA GV746 UT WOS:A1991GV74600002 ER PT J AU GARRETT, WR HART, RC MILLER, JC PAYNE, MG WRAY, JE AF GARRETT, WR HART, RC MILLER, JC PAYNE, MG WRAY, JE TI LARGE SPECTRAL SHIFTS OF STIMULATED HYPER-RAMAN SCATTERING - PREDICTIONS AND OBSERVATIONS IN XE SO OPTICS COMMUNICATIONS LA English DT Article ID MULTI-PHOTON IONIZATION; 3-PHOTON RESONANCE; MULTIPHOTON IONIZATION; FREQUENCY-SHIFT; XENON; INTERFERENCE; EXCITATION; EMISSION; KRYPTON; GENERATION AB The influence of near-resonant sum or difference frequency-mixing fields on multiphoton excitations can produce large pressure-dependent lineshifts for odd-photon resonances, as recently reported by Garrett et al. [Phys. Rev. Lett. 64 (1990) 1717]. Stimulated hyper-Raman emission from Xe is shown to exhibit similar pressure dependent shifts. RP GARRETT, WR (reprint author), OAK RIDGE NATL LAB,CHEM PHYS SECT,POB 2008,OAK RIDGE,TN 37831, USA. NR 17 TC 17 Z9 17 U1 0 U2 2 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0030-4018 J9 OPT COMMUN JI Opt. Commun. PD NOV 1 PY 1991 VL 86 IS 2 BP 205 EP 210 DI 10.1016/0030-4018(91)90561-Q PG 6 WC Optics SC Optics GA GP936 UT WOS:A1991GP93600020 ER PT J AU GOSNELL, TR MACPHERSON, DC TAYLOR, AJ AF GOSNELL, TR MACPHERSON, DC TAYLOR, AJ TI CHIRPED-PULSE AMPLIFICATION IN XECL SO OPTICS LETTERS LA English DT Article ID ENERGY-EXTRACTION; KRF AB By using a 0.25-ps nearly transform-limited pulse and both 16- and 75-ps strongly chirped pulses of the same bandwidth, measurements of the effective saturation fluence (E(sat)) of a XeCl discharge amplifier have been performed. We find that while E(sat) for the 16-ps pulse is comparable with that of the 0.25-ps pulse, pulse stretching to a width of 75 ps increases the effective E(sat) by 35%. However, the measured values of E(sat) for the 16- and 75-ps pulses are significantly less than would be expected for transform-limited pulses of the same pulse widths. A simple rate-equation model, which takes into account variation of the small-signal gain across the gain bandpass and which assumes that E(sat) is enhanced for the longer pulse widths only by population decay of the lower electronic state, predicts the measured values of E(sat) to within the experimental error. RP GOSNELL, TR (reprint author), UNIV CALIF LOS ALAMOS SCI LAB,DIV CHEM & LASER SCI,MS E543,LOS ALAMOS,NM 87545, USA. NR 10 TC 4 Z9 4 U1 0 U2 0 PU OPTICAL SOC AMER PI WASHINGTON PA 2010 MASSACHUSETTS AVE NW, WASHINGTON, DC 20036 SN 0146-9592 J9 OPT LETT JI Opt. Lett. PD NOV 1 PY 1991 VL 16 IS 21 BP 1686 EP 1688 DI 10.1364/OL.16.001686 PG 3 WC Optics SC Optics GA GM708 UT WOS:A1991GM70800020 PM 19784109 ER PT J AU CHARALAMBOUS, A MARCINIAK, G SHIUE, CY DEWEY, SL SCHLYER, DJ WOLF, AP MAKRIYANNIS, A AF CHARALAMBOUS, A MARCINIAK, G SHIUE, CY DEWEY, SL SCHLYER, DJ WOLF, AP MAKRIYANNIS, A TI PET STUDIES IN THE PRIMATE BRAIN AND BIODISTRIBUTION IN MICE USING (-)-5'-18F-DELTA-8-THC SO PHARMACOLOGY BIOCHEMISTRY AND BEHAVIOR LA English DT Article DE (-)-5'-18F-DELTA-8-THC; BIODISTRIBUTION; PET ID CANNABINOID RECEPTOR; MEMBRANES AB Cannabinoids, the active constituents of marijuana, are known to have many therapeutic properties; however, their exact mechanism of action is not well understood. In an effort to obtain more information concerning the pharmacokinetics and biodistribution of psychoactive THC analogs we synthesized (-)-F-18-DELTA-8-THC and studied its biodistribution in mice and baboon brains. The analog was obtained by nucleophilic fluorination of the ditriflate ester of (-)-5'-OH-DELTA-8-THC with KF-18/Kryptofix followed by deprotection with LiAIH4, and purification with HPLC in 8% yield in a 90-min synthesis from EOB. The uptake of (-)-5'-F-18-DELTA-8-THC in mouse tissue was high at 5 min, but radioactivity declined rapidly in almost all the tissues studied. Following IV administration, (-)-5'-F-18-DELTA-8-THC uptake in baboon brain was similar in the basal ganglia, thalamus and cerebellum, and the clearance from these regions was relatively rapid. Also, a study from baboon plasma clearance of (-)-5'-F-18-DELTA-8-THC showed rapid metabolism of the analog. C1 UNIV CONNECTICUT, SCHOOL PHARM, DEPT MED CHEM, U-92, STORRS, CT 06269 USA. BROOKHAVEN NATL LAB, DEPT CHEM, UPTON, NY 11973 USA. CREIGHTON UNIV, CTR METAB IMAGING, OMAHA, NE 68108 USA. FU NIDA NIH HHS [DA-152, DA-3801] NR 18 TC 37 Z9 39 U1 0 U2 1 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLAND SN 0091-3057 J9 PHARMACOL BIOCHEM BE JI Pharmacol. Biochem. Behav. PD NOV PY 1991 VL 40 IS 3 BP 503 EP 507 DI 10.1016/0091-3057(91)90354-5 PG 5 WC Behavioral Sciences; Neurosciences; Pharmacology & Pharmacy SC Behavioral Sciences; Neurosciences & Neurology; Pharmacology & Pharmacy GA GR804 UT WOS:A1991GR80400009 PM 1666914 ER PT J AU PENISSON, JM DAHMEN, U MILLS, MJ AF PENISSON, JM DAHMEN, U MILLS, MJ TI HREM STUDY OF A SIGMA=3(112) TWIN BOUNDARY IN ALUMINUM SO PHILOSOPHICAL MAGAZINE LETTERS LA English DT Article ID RESOLUTION ELECTRON-MICROSCOPY; ATOMIC-STRUCTURE; GRAIN-BOUNDARY; TILT BOUNDARY; METALS; GOLD AB An incoherent {112} twin boundary in aluminium has been observed by high resolution electron microscopy. No rigid body translation parallel to the boundary plane has been found. The experimental structure is in agreement with one of the calculated models. The junction of the {112} segment with a coherent {111} boundary is also studied. C1 UNIV CALIF BERKELEY,LAWRENCE BERKELEY LAB,NATL CTR ELECTRON MICROSCOPY,BERKELEY,CA 94720. SANDIA NATL LABS,LIVERMORE,CA 94551. RP PENISSON, JM (reprint author), CEN GRENOBLE 85X,DEPT RECH FONDAMENTALE,F-38041 GRENOBLE,FRANCE. NR 23 TC 34 Z9 34 U1 1 U2 5 PU TAYLOR & FRANCIS LTD PI LONDON PA ONE GUNDPOWDER SQUARE, LONDON, ENGLAND EC4A 3DE SN 0950-0839 J9 PHIL MAG LETT JI Philos. Mag. Lett. PD NOV PY 1991 VL 64 IS 5 BP 277 EP 283 DI 10.1080/09500839108214622 PG 7 WC Materials Science, Multidisciplinary; Metallurgy & Metallurgical Engineering; Physics, Applied; Physics, Condensed Matter SC Materials Science; Metallurgy & Metallurgical Engineering; Physics GA GP579 UT WOS:A1991GP57900005 ER PT J AU ABRIKOSOV, AA AF ABRIKOSOV, AA TI RAMAN LIGHT-SCATTERING BY ELECTRONS IN LAYERED SUPERCONDUCTORS SO PHYSICA C LA English DT Article AB Raman light scattering by electrons in a layered model of HTSC is considered. The superconductor is supposed to consist of alternating layers of two kinds: (1) layers with an attractive electron interaction and an effective mass of usual magnitude, (2) layers without interaction and with a large effective mass. The overlap between the layers is assumed to be small, its energy t being less than DELTA. It is shown, that such a model explains the most peculiar property found in experiment: different threshold values for the Raman satellite measured at different polarizations of the incident and scattered light. Comparison is given with the tunneling data and possible extensions of the model are discussed. RP ABRIKOSOV, AA (reprint author), ARGONNE NATL LAB,DIV MAT SCI,9700 S CASS AVE,ARGONNE,IL 60439, USA. NR 6 TC 52 Z9 52 U1 1 U2 1 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0921-4534 J9 PHYSICA C JI Physica C PD NOV 1 PY 1991 VL 182 IS 4-6 BP 191 EP 202 DI 10.1016/0921-4534(91)90513-X PG 12 WC Physics, Applied SC Physics GA GR638 UT WOS:A1991GR63800001 ER PT J AU BALTZ, AJ RHOADESBROWN, MJ WENESER, J AF BALTZ, AJ RHOADESBROWN, MJ WENESER, J TI ENERGY-DEPENDENCE OF BOUND-ELECTRON POSITRON PAIR PRODUCTION AT VERY-HIGH-ENERGY ION-ION TRANSITS SO PHYSICAL REVIEW A LA English DT Article ID COLLISIONS AB The problem of calculating the cross section for bound-electron-positron pair creation in very-high-energy heavy-ion colliders (100 GeV/u or higher, an effective gamma greater-than-or-similar-to 2 x 10(4)) is addressed. The multipole decomposition of the basic time-varying interaction is explicitly written in terms of simple and compact forms that display the energy (gamma) dependence directly. Then, specific gauge transforms remove the gamma-dependence for smaller impact parameters, up to negligible terms of higher order in 1/gamma. For larger impact parameters b, the interaction is shown to weaken as 1/b, where the known perturbative results apply. Only at small impact parameters are strong-coupling calculations necessary, but the gauge choices show that the contributions from these regions are gamma-independent. Putting these results together leads to a simple form for the cross section, A ln-gamma + B, where A and B are energy independent and A is known from the perturbative calculations. This form and its weak dependence on energy makes extrapolation from lower-energy results reliable and indicates the usefulness of a possible experiment at comparatively low energies (gamma approximately 200). C1 BROOKHAVEN NATL LAB,RELATIVIST HEAVY ION COLLIDER PROJECT,UPTON,NY 11973. RP BALTZ, AJ (reprint author), BROOKHAVEN NATL LAB,DEPT PHYS,UPTON,NY 11973, USA. NR 17 TC 50 Z9 50 U1 0 U2 0 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 1050-2947 J9 PHYS REV A JI Phys. Rev. A PD NOV 1 PY 1991 VL 44 IS 9 BP 5569 EP 5585 DI 10.1103/PhysRevA.44.5569 PG 17 WC Optics; Physics, Atomic, Molecular & Chemical SC Optics; Physics GA GP388 UT WOS:A1991GP38800028 ER PT J AU GAO, RS JOHNSON, LK SMITH, GJ HAKES, CL SMITH, KA LANE, NF STEBBINGS, RF KIMURA, M AF GAO, RS JOHNSON, LK SMITH, GJ HAKES, CL SMITH, KA LANE, NF STEBBINGS, RF KIMURA, M TI COLLISIONS BETWEEN H+ AND H-2 AT KILO-ELECTRON-VOLT ENERGIES - ABSOLUTE DIFFERENTIAL CROSS-SECTIONS FOR SMALL-ANGLE DIRECT, SINGLE-CHARGE-TRANSFER, AND DOUBLE-CHARGE-TRANSFER SCATTERING SO PHYSICAL REVIEW A LA English DT Article ID CAPTURE; REGIME AB Measurements of absolute differential cross sections for H+-H-2 direct, single-, and double-charge-transfer scattering at 0.5, 1.5, and 5.0 keV are reported at laboratory scattering angles less than 1-degrees with an angular resolution of approximately 0.02-degrees. The cross sections exhibit deep interference oscillations in single-charge-transfer scattering, but no such oscillations are present in direct and double-charge-transfer scattering. Theoretical cross sections derived using the diatoms-in-molecules method to describe the molecular states in a semiclassical molecular-orbital three-state close-coupling model within a semiclassical framework agree satisfactorily with the experimental results. C1 RICE UNIV,DEPT SPACE PHYS & ASTRON,HOUSTON,TX 77251. RICE UNIV,RICE QUANTUM INST,HOUSTON,TX 77251. ARGONNE NATL LAB,ER 203,ARGONNE,IL 60439. RP GAO, RS (reprint author), RICE UNIV,DEPT PHYS,HOUSTON,TX 77251, USA. RI Gao, Ru-Shan/H-7455-2013 NR 8 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 1050-2947 J9 PHYS REV A JI Phys. Rev. A PD NOV 1 PY 1991 VL 44 IS 9 BP 5599 EP 5604 DI 10.1103/PhysRevA.44.5599 PG 6 WC Optics; Physics, Atomic, Molecular & Chemical SC Optics; Physics GA GP388 UT WOS:A1991GP38800030 ER PT J AU BRUCH, R SCHNEIDER, D CHEN, MH CHUNG, KT DAVIS, BF AF BRUCH, R SCHNEIDER, D CHEN, MH CHUNG, KT DAVIS, BF TI PROJECTILE-K AUGER-SPECTRA OF LI-LIKE, BE-LIKE, AND B-LIKE MULTIPLY CHARGED NE IONS - AUGER ENERGIES, AUGER RATES, AND INTENSITY RATIOS SO PHYSICAL REVIEW A LA English DT Article ID RAY-EMISSION RATES; EIGENVALUE SCHRODINGER-EQUATION; FLUORESCENCE YIELDS; RELATIVISTIC AUGER; 1S2LN(2L')M CONFIGURATIONS; RADIATIVE DEEXCITATION; IONIZED NEON; STATES; TRANSITION; COLLISIONS AB In this work we have made an intense theoretical effort to determine accurate K-Auger transition energies, Auger rates, and line intensity ratios for Be- and B-like multiply charged neon ions using several different atomic models. Theoretical data on Li-like states in Ne VIII are also reported. In particular a detailed study of Auger line intensity ratios is presented. For several Be- and B-like states strong cancellations in the Auger matrix elements are predicted. These rates are quite sensitive to the atomic wave functions. We have also deduced experimental Auger intensity ratios for Be and B-like Ne ions from previous data. In order to classify our high-resolution projectile spectra, theoretical Auger energies and rates for various terms of the electron configurations 1s2s(2)2pn-1, 1s2pn+1, and 1s2s2p(n) (n = 1-3) have been calculated relativistically, using the saddle-point technique, the multiconfiguration Dirac-Fock model, and the 1/Z expansion method. Several previously unknown line identifications of Be-like states in Ne VII and B-like states in Ne VI are reported. C1 UNIV CALIF LAWRENCE LIVERMORE NATL LAB,DIV HIGH TEMP PHYS,LIVERMORE,CA 94550. N CAROLINA STATE UNIV,DEPT PHYS,RALEIGH,NC 27650. UNIV N CAROLINA,DEPT PHYS,WILMINGTON,NC 28403. RP BRUCH, R (reprint author), UNIV NEVADA,DEPT PHYS,RENO,NV 89557, USA. OI Davis, Brian/0000-0003-4043-8077 NR 62 TC 14 Z9 15 U1 0 U2 2 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 1050-2947 J9 PHYS REV A JI Phys. Rev. A PD NOV 1 PY 1991 VL 44 IS 9 BP 5659 EP 5673 DI 10.1103/PhysRevA.44.5659 PG 15 WC Optics; Physics, Atomic, Molecular & Chemical SC Optics; Physics GA GP388 UT WOS:A1991GP38800040 ER PT J AU BURGDORFER, J LERNER, P MEYER, FW AF BURGDORFER, J LERNER, P MEYER, FW TI ABOVE-SURFACE NEUTRALIZATION OF HIGHLY CHARGED IONS - THE CLASSICAL OVER-THE-BARRIER MODEL SO PHYSICAL REVIEW A LA English DT Article ID ELECTRON-EMISSION; TUNGSTEN SURFACE; CROSS-SECTIONS; METAL-SURFACE; COLLISIONS; AUGER; ATOMS AB The neutralization of highly charged ions during interaction with metallic surfaces is accompanied by the ejection of a large number of secondary electrons. Recent experiments demonstrate two main contributions to this electron ejection process: one from the region below the surface and the second from the above-surface portion of the trajectory. We present a theoretical analysis of the neutralization dynamics above the surface, prior to impact, based on the classical over-the-barrier model. The theory incorporates resonant multielectron capture of conduction electrons, resonant loss into unoccupied states of the conduction band, and intra-atomic Auger deexcitation. The effective barrier potential includes quantum corrections to the classical image potential. The effect of below-barrier ("tunneling") transfer is investigated. The solution of a coupled system of rate equations allows the approximate determination of the n-shell populations, the projectile charge state, and the total number of Auger electrons. The calculation describes the transient formation of "hollow" atoms. We find satisfactory agreement with recent data for K Auger yields by Meyer et al. C1 OAK RIDGE NATL LAB,OAK RIDGE,TN 37831. RP BURGDORFER, J (reprint author), UNIV TENNESSEE,DEPT PHYS,KNOXVILLE,TN 37996, USA. OI Lerner , Peter/0000-0002-3086-0170 NR 49 TC 427 Z9 441 U1 3 U2 19 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 1050-2947 J9 PHYS REV A JI Phys. Rev. A PD NOV 1 PY 1991 VL 44 IS 9 BP 5674 EP 5685 DI 10.1103/PhysRevA.44.5674 PG 12 WC Optics; Physics, Atomic, Molecular & Chemical SC Optics; Physics GA GP388 UT WOS:A1991GP38800041 ER PT J AU BAUCHE, J BAUCHEARNOULT, C WYART, JF DUFFY, P KLAPISCH, M AF BAUCHE, J BAUCHEARNOULT, C WYART, JF DUFFY, P KLAPISCH, M TI SIMULATION OF ATOMIC TRANSITION ARRAYS FOR OPACITY CALCULATIONS SO PHYSICAL REVIEW A LA English DT Article ID PARAMETRIC POTENTIAL METHOD; X-RAY-SPECTRA; STATISTICAL SPECTROSCOPY; STRENGTH DISTRIBUTIONS; IONIZED ATOMS; ENERGY-LEVELS; CONFIGURATIONS; VARIANCE; PROGRAM; PLASMA AB A method is proposed for simulating resolved transition arrays of ionized atom spectra in full intermediate coupling. The wave number and intensity of each line in an array are picked at random from separated but correlated distributions. Even though each line is not exactly reproduced, this procedure yields the correct following characteristics of the supposedly symmetric array: total intensity; second and fourth moments of the distributions of unweighted wave numbers, of intensity-weighted wave numbers, and of transition amplitudes; numbers of lines and sums of intensities in consecutive narrow energy ranges. All the parameters of the distribution are obtained by means of compact formulas, or tabulated. Applications to the arrays 4d4-4d(3)5p of Pd6+ and 4d(7)5s-4d(7)5p of Cd4+ are presented. Comparison with the explicit results of the Slater-Condon method shows good agreement. It is proposed to use this method for fast and reliable computation of Rosseland means and other opacity properties. C1 UNIV CALIF LAWRENCE LIVERMORE NATL LAB,LIVERMORE,CA 94550. UNIV CALIF BERKELEY,LAWRENCE BERKELEY LAB,BERKELEY,CA 94720. RP BAUCHE, J (reprint author), LAB AIMEE COTTON,BATIMENT 505,F-91405 ORSAY,FRANCE. NR 39 TC 31 Z9 31 U1 0 U2 0 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 1050-2947 J9 PHYS REV A JI Phys. Rev. A PD NOV 1 PY 1991 VL 44 IS 9 BP 5707 EP 5714 DI 10.1103/PhysRevA.44.5707 PG 8 WC Optics; Physics, Atomic, Molecular & Chemical SC Optics; Physics GA GP388 UT WOS:A1991GP38800045 ER PT J AU DUFFY, P KLAPISCH, M BAUCHE, J BAUCHEARNOULT, C AF DUFFY, P KLAPISCH, M BAUCHE, J BAUCHEARNOULT, C TI MONTE-CARLO SIMULATION OF COMPLEX SPECTRA FOR OPACITY CALCULATIONS SO PHYSICAL REVIEW A LA English DT Article AB A Monte Carlo technique for modeling spectra with many resolved lines of ions in intermediate coupling was presented in the preceding paper [Phys. Rev. A 44, 5707 (1991)]. We use the same concept here with a modification for the near-LS-coupling case. Rosseland and Planck means of transition arrays of Fe V and Fe VI are evaluated. Comparison with "exact" computations shows much better agreement than is found using the simple unresolved-transition-array approximation. C1 UNIV CALIF BERKELEY,LAWRENCE BERKELEY LAB,BERKELEY,CA 94720. LAB AIMEE COTTON,F-91405 ORSAY,FRANCE. RP DUFFY, P (reprint author), UNIV CALIF LAWRENCE LIVERMORE NATL LAB,POB 808,LIVERMORE,CA 94550, USA. NR 9 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 1050-2947 J9 PHYS REV A JI Phys. Rev. A PD NOV 1 PY 1991 VL 44 IS 9 BP 5715 EP 5724 DI 10.1103/PhysRevA.44.5715 PG 10 WC Optics; Physics, Atomic, Molecular & Chemical SC Optics; Physics GA GP388 UT WOS:A1991GP38800046 ER PT J AU MANDELBAUM, P SEELY, JF BARSHALOM, A KLAPISCH, M AF MANDELBAUM, P SEELY, JF BARSHALOM, A KLAPISCH, M TI EFFECT OF CONFIGURATION MIXING ON 3D-4F TRANSITIONS IN HIGHLY IONIZED GA-LIKE, ZN-LIKE, AND CU-LIKE IONS SO PHYSICAL REVIEW A LA English DT Article ID X-RAY-SPECTRA; LASER-PRODUCED PLASMA; ENERGY-LEVELS; EXTENDED ANALYSIS; ATOMIC SPECTRA; TANTALUM; ARRAYS; RANGE; DISTRIBUTIONS; SEQUENCE AB It is shown that the introduction of configuration interaction through 4s4f-4p4d and 4p4f-4d2 mixing has a very significant effect on 3d-4f transitions in highly charged Ga-,Zn-, and Cu-like ions. This effect changes the width and, to a lesser extent, the mean wavelength of transition arrays as compared to the spin-orbit split array model. Because of this mixing, lines previously identified as dielectronic recombination satellites may have a non-negligible inner-shell excitation component. This should be taken into account in models for the intensities of these lines. C1 HEBREW UNIV JERUSALEM,RACAH INST PHYS,IL-91904 JERUSALEM,ISRAEL. NUCL RES CTR NEGEV,IL-84190 BEER SHEVA,ISRAEL. UNIV CALIF BERKELEY,LAWRENCE BERKELEY LAB,BERKELEY,CA 94720. RP MANDELBAUM, P (reprint author), USN,RES LAB,EO HULBURT CTR SPACE RES,WASHINGTON,DC 20375, USA. NR 19 TC 9 Z9 11 U1 0 U2 1 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 1050-2947 J9 PHYS REV A JI Phys. Rev. A PD NOV 1 PY 1991 VL 44 IS 9 BP 5744 EP 5751 DI 10.1103/PhysRevA.44.5744 PG 8 WC Optics; Physics, Atomic, Molecular & Chemical SC Optics; Physics GA GP388 UT WOS:A1991GP38800050 ER PT J AU MANDELBAUM, P SEELY, JF BROWN, CM KANIA, DR KAUFFMAN, RL AF MANDELBAUM, P SEELY, JF BROWN, CM KANIA, DR KAUFFMAN, RL TI EXTENDED ANALYSIS OF THE X-RAY-SPECTRUM EMITTED BY HIGHLY IONIZED URANIUM FROM A LASER-PRODUCED PLASMA IN THE 3.1-6.4-KEV RANGE (1.9-LESS-THAN-LAMBDA-LESS-THAN-3.9 A) SO PHYSICAL REVIEW A LA English DT Article ID ENERGY-LEVELS; TM; TRANSITIONS; TANTALUM; RE; CLASSIFICATION; ATOMS; AU AB The x-ray spectrum of laser-produced uranium plasma has been obtained in the range 3.1-6.4 keV (1.9 < lambda < 3.9 angstrom). Detailed analysis of the spectrum has been performed using the HULLAC code and the unresolved-transition-array formalism. This led to the identification of most of the features of the spectrum as transitions in the Ni-like ion (U64+) and satellite transitions of neighboring ionization states. The identification is fully consistent with the previous analysis of the spectra emitted by laser-produced plasmas of lower-Z elements. C1 HEBREW UNIV JERUSALEM,RACAH INST PHYS,IL-91904 JERUSALEM,ISRAEL. UNIV CALIF LAWRENCE LIVERMORE NATL LAB,LIVERMORE,CA 94550. RP MANDELBAUM, P (reprint author), USN,RES LAB,EO HULBURT CTR SPACE RES,WASHINGTON,DC 20375, USA. NR 17 TC 9 Z9 9 U1 2 U2 3 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 1050-2947 J9 PHYS REV A JI Phys. Rev. A PD NOV 1 PY 1991 VL 44 IS 9 BP 5752 EP 5761 DI 10.1103/PhysRevA.44.5752 PG 10 WC Optics; Physics, Atomic, Molecular & Chemical SC Optics; Physics GA GP388 UT WOS:A1991GP38800051 ER PT J AU HAN, SJ AF HAN, SJ TI STABILITY OF AN IMPLODING SPHERICAL-SHELL SO PHYSICAL REVIEW A LA English DT Article ID RAYLEIGH-TAYLOR INSTABILITY; HYDRODYNAMIC INSTABILITIES; PLASMA SHELL; DRIVEN; AMPLIFICATION; TURBULENCE; TOMOGRAPHY; TOKAMAK AB It is shown that, in an imploding spherical shell, the surface instabilities are of two different types. The first, which occurs at the outer surface, is the well-known Rayleigh-Taylor instability. The second instability occurs at the inner surface. The characteristics of this instability are similar to those of amplified sound waves in an imploding plasma shell. It is suggested that this instability is driven by the amplified sound waves. RP HAN, SJ (reprint author), UNIV CALIF LOS ALAMOS SCI LAB,LOS ALAMOS,NM 87545, USA. NR 35 TC 1 Z9 1 U1 0 U2 0 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 1050-2947 J9 PHYS REV A JI Phys. Rev. A PD NOV 1 PY 1991 VL 44 IS 9 BP 5784 EP 5792 DI 10.1103/PhysRevA.44.5784 PG 9 WC Optics; Physics, Atomic, Molecular & Chemical SC Optics; Physics GA GP388 UT WOS:A1991GP38800054 ER PT J AU HALKA, M BRYANT, HC MACKERROW, EP MILLER, W MOHAGHEGHI, AH TANG, CY COHEN, S DONAHUE, JB HSU, A QUICK, CR TIEE, J ROZSA, K AF HALKA, M BRYANT, HC MACKERROW, EP MILLER, W MOHAGHEGHI, AH TANG, CY COHEN, S DONAHUE, JB HSU, A QUICK, CR TIEE, J ROZSA, K TI OBSERVATION OF THE PARTIAL DECAY INTO H0(N'=2) BY EXCITED H- NEAR THE N=3 AND 4 THRESHOLDS SO PHYSICAL REVIEW A LA English DT Note ID 2-ELECTRON IONIZATION LADDER; N = 3; HYDROGEN-ATOMS; RESONANCES AB Two resonances in the photodetachment spectrum of H-, one just below the n = 3 threshold and the other just below the n = 4 threshold, were observed decaying into H0(n' = 2) + e. The n = 3 resonance shows a preference for the n' = 2 channel when compared with total-detachment measurements. Fanoline-shape fits give central energies of 12.652 +/- 0.003 eV for H-**(3) and 13.338 +/- 0.004 eV for H-**(4). These values are in good agreement with current theoretical calculations. C1 UNIV CALIF LOS ALAMOS SCI LAB,LOS ALAMOS,NM 87545. HUNGARIAN ACAD SCI,H-1361 BUDAPEST 5,HUNGARY. RP HALKA, M (reprint author), UNIV NEW MEXICO,DEPT PHYS & ASTRON,ALBUQUERQUE,NM 87131, USA. NR 25 TC 36 Z9 36 U1 0 U2 0 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 1050-2947 J9 PHYS REV A JI Phys. Rev. A PD NOV 1 PY 1991 VL 44 IS 9 BP 6127 EP 6129 DI 10.1103/PhysRevA.44.6127 PG 3 WC Optics; Physics, Atomic, Molecular & Chemical SC Optics; Physics GA GP388 UT WOS:A1991GP38800092 ER PT J AU COLLINS, LA CSANAK, G AF COLLINS, LA CSANAK, G TI MULTIPHOTON RESONANCES IN E+H+ SCATTERING IN A LINEARLY POLARIZED RADIATION-FIELD SO PHYSICAL REVIEW A LA English DT Note ID FREQUENCY LASER FIELDS; CIRCULAR-POLARIZATION; ATOMIC-HYDROGEN; SUPERINTENSE; ELECTRONS; STABILIZATION; DISTORTION; MOLECULES AB We report a solution of the Gavrila-Kaminski coupled-channel system of equations describing the continuum states of an electron in the combined field of a Coulomb potential and a linearly polarized intense radiation field. Convergence was achieved in the number of Floquet states and partial waves for intensities up to 3 x 10(14) W/cm2 at a photon energy of 7.35 eV. In addition, we observed the one-and two-photon capture-escape resonances. RP COLLINS, LA (reprint author), UNIV CALIF LOS ALAMOS SCI LAB,DIV NEUROL,GRP T-4,LOS ALAMOS,NM 87545, USA. NR 21 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 1050-2947 J9 PHYS REV A JI Phys. Rev. A PD NOV 1 PY 1991 VL 44 IS 9 BP R5343 EP R5345 PG 3 WC Optics; Physics, Atomic, Molecular & Chemical SC Optics; Physics GA GP388 UT WOS:A1991GP38800004 ER PT J AU KIMURA, M AF KIMURA, M TI H(N = 2 AND 3) DENSITY-MATRICES RESULTING FROM LOW-ENERGY TO INTERMEDIATE-ENERGY COLLISIONS OF H+ IONS WITH HE ATOMS - THE ATOMIC-ORBITAL MOLECULAR-ORBITAL MATCHING APPROACH SO PHYSICAL REVIEW A LA English DT Note ID CHARGE-TRANSFER COLLISIONS; CROSS-SECTIONS; EXCITATION; POLARIZATION; H(2P) AB The density matrices of excited H atoms (n = 2 and 3 manifolds) resulting from electron capture in collisions of H+ ions with He atoms in the energy region from 1 to 100 keV/amu are investigated on the basis of the atomic-orbital-molecular-orbital matching approach. Two electrons in the system are explicitly included in the calculation. The present results for the electric dipole moment, electron current density distributions, and alignment parameters compare favorably with recent measurements by Cline (unpublished), Hippler et al. [Phys. Rev. A 43, 2587 (1991)], and Ashburn et al. [Phys. Rev. A 41, 2407 (1990)] in the entire energy regions studied, and reveal similarities of these quantities for n = 2 and n = 3. Some insights of the similarities are discussed. C1 RICE UNIV,DEPT PHYS,HOUSTON,TX 77251. RP KIMURA, M (reprint author), ARGONNE NATL LAB,ARGONNE,IL 60439, USA. NR 22 TC 9 Z9 9 U1 0 U2 1 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 1050-2947 J9 PHYS REV A JI Phys. Rev. A PD NOV 1 PY 1991 VL 44 IS 9 BP R5339 EP R5342 PG 4 WC Optics; Physics, Atomic, Molecular & Chemical SC Optics; Physics GA GP388 UT WOS:A1991GP38800003 ER PT J AU WENTZCOVITCH, RM LAM, PK AF WENTZCOVITCH, RM LAM, PK TI FCC-TO-HCP TRANSFORMATION - A 1ST-PRINCIPLES INVESTIGATION SO PHYSICAL REVIEW B LA English DT Article ID ABINITIO CALCULATION; AL; TRANSITIONS; PHASES AB A distortion model for the fcc --> hcp transformation is introduced. It predicts an orientational relationship between parent and daughter phases which is very different from that implied by the Shoji-Nishyiama model. By means of first-principles total-energy calculations, we investigate this pressure-induced transformation in Al and compare the energy barriers along the reconstructional routes implied by both models. We conclude that, from the energetic point of view, both models are equally favorable. C1 UNIV HAWAII MANOA,DEPT PHYS & ASTRON,HONOLULU,HI 96822. RP WENTZCOVITCH, RM (reprint author), BROOKHAVEN NATL LAB,DEPT PHYS,UPTON,NY 11793, USA. RI Wentzcovitch, Renata/J-8768-2015 NR 17 TC 8 Z9 8 U1 1 U2 3 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 0163-1829 J9 PHYS REV B JI Phys. Rev. B PD NOV 1 PY 1991 VL 44 IS 17 BP 9155 EP 9158 DI 10.1103/PhysRevB.44.9155 PG 4 WC Physics, Condensed Matter SC Physics GA GP267 UT WOS:A1991GP26700001 ER PT J AU SHAPIRO, SM YANG, BX NODA, Y TANNER, LE SCHRYVERS, D AF SHAPIRO, SM YANG, BX NODA, Y TANNER, LE SCHRYVERS, D TI NEUTRON-SCATTERING AND ELECTRON-MICROSCOPY STUDIES OF THE PREMARTENSITIC PHENOMENA IN NIXAL100-X ALLOYS SO PHYSICAL REVIEW B LA English DT Article ID NI-AL ALLOYS; THERMOELASTIC MARTENSITIC-TRANSFORMATION; STRUCTURAL PHASE-TRANSITIONS; MODULATED LATTICE-RELAXATION; TWEED MICROSTRUCTURES; CRYSTAL-STRUCTURE; BETA-1 ALLOY; OMEGA-PHASE; DIFFRACTION; NUCLEATION AB Inelastic-neutron-scattering and electron-microscopy studies were performed on single crystals of the cubic phase of Ni(x)Al100-x alloys for x = 50, 58, 62.5, and 63.9 at. %. The [110]-TA2 phonon branch, corresponding to atomic displacements along the [110] direction, is shown to exhibit anomalous behavior in that the entire branch is very sensitive to composition and exhibits a "kink" whose position in q space is also sensitive to x. A peak in the elastic diffuse scattering is also present at the same q as the kink. Amplitude-contrast electron-microscope images display a "tweed" pattern characteristic of many martensitically transforming materials. The high-resolution (phase-contrast) electron image reveals microscopic deviations of the cubic structure and can be viewed as embryos of the low-temperature (5,2BAR) martensitic phase. The displacement fields associated with these distortions are shown to be the origin of the elastic central peak observed in the experiments. Temperature-dependence studies show a substantial softening of the phonon branch in the vicinity of the kink and the elastic diffuse scattering increases as T approaches T(M), the martensitic-transformation onset temperature. The mode never becomes completely soft. Furthermore, the softening is narrowly restricted to the [110BAR] direction, which is perpendicular to [110]. Studies of the phonon dispersion curve under uniaxial stress show a softening of the phonon mode near the q value of the kink, which can be interpreted in terms of Clapp's proposed localized-soft-mode theory of nucleation of materials undergoing martensitic transformation. C1 ANTWERP STATE UNIV CTR,B-2020 ANTWERP,BELGIUM. CHIBA UNIV,CHIBA 260,JAPAN. UNIV CALIF LAWRENCE LIVERMORE NATL LAB,LIVERMORE,CA 94550. UNIV WESTERN ONTARIO,DEPT CHEM,LONDON N6A 5B7,ONTARIO,CANADA. RP SHAPIRO, SM (reprint author), BROOKHAVEN NATL LAB,UPTON,NY 11973, USA. NR 71 TC 125 Z9 125 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 NOV 1 PY 1991 VL 44 IS 17 BP 9301 EP 9313 DI 10.1103/PhysRevB.44.9301 PG 13 WC Physics, Condensed Matter SC Physics GA GP267 UT WOS:A1991GP26700019 ER PT J AU CHOI, M BUDNICK, JI PEASE, DM HAYES, GH HEALD, SM AF CHOI, M BUDNICK, JI PEASE, DM HAYES, GH HEALD, SM TI THERMAL VARIATION OF THE MEAN-SQUARE RELATIVE DISPLACEMENT FOR THE PT-PT PAIR IN THE NI10PT90 RANDOM SOLID-SOLUTION ALLOY SO PHYSICAL REVIEW B LA English DT Article ID ABSORPTION FINE-STRUCTURE AB The Pt L3-edge extended x-ray-absorption fine-structure measurements were made on the Ni10Pt90 random solid-solution alloy, as well as on pure Pt, at four different temperatures (in the range 7 K less-than-or-similar-to T less-than-or-equal-to 300 K). The data have been analyzed with the ratio fit, to obtain the relative values of the nearest-neighbor mean-square relative displacement (MSRD) for the Pt-Pt pair in each temperature case with respect to the MSRD value for the Pt-Pt pair in pure Pt at 7 K. For the Ni10Pt90-alloy cases, only a high-k region above approximately 12 angstrom-1 was used for the ratio fit. In this approach, the contribution of Ni-neighbor backscattering is assumed to be negligibly small in the high-k region where the Pt backscattering overwhelms the Ni backscattering, since about 90% of the nearest neighbors are Pt atoms. The intercept values of the ratio fits agree well with the expected values, indicating that this approximation is valid. Subsequently the MSRD values were determined by Einstein-model fits. The Debye-model fit was also tried for the pure-Pt data, and the Debye temperature obtained from the fit is 240 K, showing the good quality of the data. The results of the ratio fit for the Ni10Pt90 data are in good agreement with those of two-shell fits. C1 UNIV CONNECTICUT,DEPT PHYS,STORRS,CT 06269. UNIV CONNECTICUT,INST MAT SCI,STORRS,CT 06269. BROOKHAVEN NATL LAB,UPTON,NY 11973. NR 20 TC 5 Z9 5 U1 0 U2 0 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 0163-1829 J9 PHYS REV B JI Phys. Rev. B PD NOV 1 PY 1991 VL 44 IS 17 BP 9319 EP 9324 DI 10.1103/PhysRevB.44.9319 PG 6 WC Physics, Condensed Matter SC Physics GA GP267 UT WOS:A1991GP26700021 ER PT J AU MATTSON, JE BRUBAKER, ME SOWERS, CH CONOVER, M QIU, Z BADER, SD AF MATTSON, JE BRUBAKER, ME SOWERS, CH CONOVER, M QIU, Z BADER, SD TI TEMPERATURE-DEPENDENCE OF THE MAGNETORESISTANCE OF SPUTTERED FE/CR SUPERLATTICES SO PHYSICAL REVIEW B LA English DT Article ID GIANT MAGNETORESISTANCE; MULTILAYERED STRUCTURES; FE AB The temperature dependence of the resistivity of three sputtered Fe/Cr superlattices was analyzed. Two are antiferromagnetic and one is ferromagnetic. Also, a series of Fe/Cr superlattices was characterized as a function of Cr thickness by means of resistivity, Kerr-rotation, and x-ray-diffraction measurements. Magnetoresistance measurements for films with 32-angstrom Fe layers confirm the presence of three oscillations with peaks at approximately 11, 27, and 42 angstrom Cr. The Kerr-rotation measurements for fixed Fe thicknesses of 15, 25, 32 and 40 angstrom indicate that the first antiferromagnetic region is always between approximately 6 and 17 angstrom Cr thickness. The low-angle x-ray results show that the structure is not ideal, based on comparison to dynamical simulation or to the quality of similarly prepared Fe/Mo superlattices. The magnetoresistivity of the antiferromagnetic films decays from its maximum value at low temperature with a T2 behavior below approximately 100 K, while a ferromagnetic film could be similarly approximated by a T3/2 behavior. These power laws are a consequence of the thermal excitation of magnons in these anisotropic antiferromagnetic and ferromagnetic superlattices, respectively. The resistivities due to sd-interband scattering rho-sd are approximated by a T2 behavior and roughly a T3 behavior, respectively. This indicates that for the antiferromagnetic films the dominant contributions to rho-sd come from processes mediated by magnons as well as phonons. RP MATTSON, JE (reprint author), ARGONNE NATL LAB,DIV MAT SCI,ARGONNE,IL 60439, USA. RI Bader, Samuel/A-2995-2013 NR 36 TC 71 Z9 72 U1 0 U2 5 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 0163-1829 J9 PHYS REV B JI Phys. Rev. B PD NOV 1 PY 1991 VL 44 IS 17 BP 9378 EP 9384 DI 10.1103/PhysRevB.44.9378 PG 7 WC Physics, Condensed Matter SC Physics GA GP267 UT WOS:A1991GP26700028 ER PT J AU WU, RQ LI, C FREEMAN, AJ FU, CL AF WU, RQ LI, C FREEMAN, AJ FU, CL TI STRUCTURAL, ELECTRONIC, AND MAGNETIC-PROPERTIES OF RARE-EARTH-METAL SURFACES - HCP GD(0001) SO PHYSICAL REVIEW B LA English DT Article ID BULK CURIE-TEMPERATURE; FERROMAGNETIC ORDER; PHASE-TRANSITIONS; GD FILMS; SPIN; INTERFACES; W(001); IRON; EU; TB AB Structural, electronic, and magnetic properties of the hcp Gd(0001) surface have been determined using the all-electron local-density full-potential linearized augmented-plane-wave method. A precise total-energy analysis reveals that (1) surface Gd atoms occupy the hcp sites; the outermost interlayer spacing expands by approximately 6%; (2) the surface Gd layer couples antiferromagnetically with the underlying ferromagnetic bulk; and (3) the energy stability of the surface antiferromagnetic coupling arises from the enhancement of the second-neighbor interactions. A localized d(z)2 surface state is found near the GAMMA-BAR point, which is occupied (empty) in the majority (minority)-spin band and results in an enhancement of the surface magnetic moment. C1 OAK RIDGE NATL LAB,OAK RIDGE,TN 37831. RP WU, RQ (reprint author), NORTHWESTERN UNIV,DEPT PHYS & ASTRON,EVANSTON,IL 60208, USA. RI Wu, Ruqian/C-1395-2013 OI Wu, Ruqian/0000-0002-6156-7874 NR 59 TC 120 Z9 120 U1 0 U2 4 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 0163-1829 J9 PHYS REV B JI Phys. Rev. B PD NOV 1 PY 1991 VL 44 IS 17 BP 9400 EP 9409 DI 10.1103/PhysRevB.44.9400 PG 10 WC Physics, Condensed Matter SC Physics GA GP267 UT WOS:A1991GP26700031 ER PT J AU ZYSLER, RD TOVAR, M RETTORI, C RAO, D SHORE, H OSEROFF, SB VIER, DC SCHULTZ, S FISK, Z CHEONG, SW AF ZYSLER, RD TOVAR, M RETTORI, C RAO, D SHORE, H OSEROFF, SB VIER, DC SCHULTZ, S FISK, Z CHEONG, SW TI DIFFERENT GD3+ SITES ASSOCIATED WITH MAGNETIC-ORDERING AND STRUCTURAL DISTORTIONS IN EU2CUO4-GD3+ OBSERVED VIA ELECTRON-PARAMAGNETIC-RESONANCE MEASUREMENTS SO PHYSICAL REVIEW B LA English DT Article ID POPULATION ANALYSIS; PHASE-TRANSITIONS; CRYSTAL-STRUCTURE; SPIN CORRELATIONS; GD2CUO4 CRYSTALS; CHARGE-CARRIERS; SUPERCONDUCTORS; ND2CUO4; REDETERMINATION; PR2CUO4 AB We have measured the EPR spectrum of dilute Gd3+ ions substituting for EU3+ in Eu2CuO4. Each one of the resonance lines shows a splitting into two or more weaker lines below T(N) almost-equal-to 215 K. The simultaneous appearance of a low-field microwave-absorption signal is attributed to the onset of long-range antiferromagnetic ordering with a weak ferromagnetic component. The splitting of the EPR spectrum is associated with different Gd sites in the magnetically ordered structure. A reduction of the local symmetry of the rare-earth sites below T(N) is described in terms of an internal magnetic field lying in the ab plane and additional crystal-field terms related to local crystallographic distortions. Dipolar and exchange contributions to the internal field are discussed. Possible random static displacements of the oxygen atoms in the CuO2 planes and their role-in the development of the weak ferromagnetism and the presence of internal fields at the Gd sites are also analyzed. A strong dependence of the Gd EPR spectrum and the microwave absorption on the magnetic history of the samples has been observed, suggesting the formation of magnetic domains or a glassy state. C1 UNICAMP,INST FIS,BR-13081 CAMPINAS,SP,BRAZIL. INST BALSEIRO,RA-8400 BARILOCHE,RIO NEGRO,ARGENTINA. SAN DIEGO STATE UNIV,DEPT PHYS,SAN DIEGO,CA 92182. UNIV CALIF SAN DIEGO,DEPT PHYS,LA JOLLA,CA 92093. UNIV CALIF LOS ALAMOS SCI LAB,LOS ALAMOS,NM 87545. AT&T BELL LABS,MURRAY HILL,NJ 07974. RP ZYSLER, RD (reprint author), CTR ATOM BARILOCHE,RA-8400 BARILOCHE,RIO NEGRO,ARGENTINA. RI Rettori, Carlos/C-3966-2012; Inst. of Physics, Gleb Wataghin/A-9780-2017 OI Rettori, Carlos/0000-0001-6692-7915; NR 28 TC 27 Z9 27 U1 0 U2 1 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 0163-1829 J9 PHYS REV B JI Phys. Rev. B PD NOV 1 PY 1991 VL 44 IS 17 BP 9467 EP 9479 DI 10.1103/PhysRevB.44.9467 PG 13 WC Physics, Condensed Matter SC Physics GA GP267 UT WOS:A1991GP26700038 ER PT J AU ALLEN, PG DELEON, JM CONRADSON, SD BISHOP, AR AF ALLEN, PG DELEON, JM CONRADSON, SD BISHOP, AR TI CHARACTERIZATION OF A SPLIT AXIAL-OXYGEN SITE IN TLBA2CA3CU4O11 BY EXTENDED X-RAY-ABSORPTION FINE-STRUCTURE SPECTROSCOPY SO PHYSICAL REVIEW B LA English DT Article ID CRYSTAL-STRUCTURE; SUPERCONDUCTING TL2BA2CACU2O8; NEUTRON-DIFFRACTION; TC; YBA2CU3O7-DELTA; TL2BA2CA2CU3O10; SCATTERING; RANGE AB The Cu K-edge extended x-ray-absorption fine structure (EXAFS) of TlBa2Ca3Cu4O11 (T(c) = 118 K) is analyzed in the range 10 less-than-or-equal-to T less-than-or-equal-to 156 K. Nonlinear-least-squares fits to the EXAFS Cu-axial-oxygen contributions show the presence of two equally populated axial-oxygen sites at R1 = 2.57 angstrom and R2 = 2.74 angstrom for temperatures above T(c), and at 10 K. The corresponding Tl-axial-oxygen distances are 2.18 and 2.01 angstrom, which are similar to those found in other thallium superconducting phases. In a fluctuation region below T(c), (T = 100, 117 K), the separation between the two sites decreases to less than 0.10 angstrom. This effect is analogous to the one previously reported in YBa2Cu3O7, suggesting a similar coupling between elastic degrees of freedom and superconductivity. We note, however, that both the separation between the sites and the decrease in this separation within the fluctuation region are greater than in YBa2Cu3O7. C1 UNIV CALIF LOS ALAMOS SCI LAB,CONDENSED MATTER THEORY GRP,LOS ALAMOS,NM 87545. RP ALLEN, PG (reprint author), UNIV CALIF LOS ALAMOS SCI LAB,ELECTR RES GRP,LOS ALAMOS,NM 87545, USA. NR 32 TC 34 Z9 34 U1 0 U2 4 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 0163-1829 J9 PHYS REV B JI Phys. Rev. B PD NOV 1 PY 1991 VL 44 IS 17 BP 9480 EP 9485 DI 10.1103/PhysRevB.44.9480 PG 6 WC Physics, Condensed Matter SC Physics GA GP267 UT WOS:A1991GP26700039 ER PT J AU VERWERFT, M VANTENDELOO, G HINKS, DG DABROWSKI, B RICHARDS, DR MITCHELL, AW MARX, DT PEI, SY JORGENSEN, JD AF VERWERFT, M VANTENDELOO, G HINKS, DG DABROWSKI, B RICHARDS, DR MITCHELL, AW MARX, DT PEI, SY JORGENSEN, JD TI INCOMMENSURATE MODULATION IN THE HIGH-TC SUPERCONDUCTOR BA1-XKXBIO3 AND ITS RELATION TO THE CONDUCTING PROPERTIES SO PHYSICAL REVIEW B LA English DT Article ID METAL-INSULATOR-TRANSITION; NEUTRON-DIFFRACTION; O SYSTEM; BAPB1-XBIXO3; BABIO3; BA2BI3+BI5+O6; TEMPERATURE; PEROVSKITE; WAVES AB The incommensurate modulation in Ba1-xKxBiO3 is studied by means of electron diffraction. Attention is paid to the symmetry of the modulation and the effect of electron irradiation. Interpretation of the modulation symmetry in cubic samples (0.3 < x < 0.5) as well as in orthorhombic samples (0.1 < x < 0.3) in the framework of a four-dimensional description allows one to determine it as a periodic displacement of the bismuth atoms. Satellite reflections corresponding to the modulation are observed only after irradiation with electrons, However, since the critical voltage is below 40 kV, it is believed that the modulation is in fact a fundamental material property. The incommensurability of the modulation for x < 0.4 results in a partial charge disproportionation on the bismuth sites, which can explain the lack of superconducting properties for Ba1-xKxBiO3 with x < 0.4. In the superconducting phase Ba0.6K0.4BiO3, the modulation is commensurate, and high-resolution observations provide evidence for a modulation model without charge disproportionation, yielding a metallic behavior at room temperature. C1 ARGONNE NATL LAB,DIV MAT SCI,ARGONNE,IL 60439. RP VERWERFT, M (reprint author), ANTWERP STATE UNIV CTR,GROENENBORGERLAAN 171,B-2020 ANTWERP,BELGIUM. NR 30 TC 23 Z9 23 U1 0 U2 1 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 0163-1829 J9 PHYS REV B JI Phys. Rev. B PD NOV 1 PY 1991 VL 44 IS 17 BP 9547 EP 9555 DI 10.1103/PhysRevB.44.9547 PG 9 WC Physics, Condensed Matter SC Physics GA GP267 UT WOS:A1991GP26700049 ER PT J AU MORRIS, DE MARKELZ, AG WEI, JYT HULTGREN, CT NICKEL, JH HAMILTON, JC MCCARTY, KF AF MORRIS, DE MARKELZ, AG WEI, JYT HULTGREN, CT NICKEL, JH HAMILTON, JC MCCARTY, KF TI SITE-SELECTIVE OXYGEN-ISOTOPE SUBSTITUTION IN YBA2CU3O7-DELTA SO PHYSICAL REVIEW B LA English DT Article ID SUPERCONDUCTIVITY AB We report selective substitution of oxygen-18 and oxygen-16 isotopes into the inequivalent oxygen lattice sites in YBa2Cu3O7-delta. The technique involves gas-phase diffusion and exploits the site dependence of diffusion rates. The CuO2-plane [O(2),O(3)] sites of YBa2Cu3O7-delta can be filled with O-18 while the apical [O(4)] and CuO-chain sites [O(1)] contain O-16 (the opposite distribution can also be made). The site-selective isotope occupation has been confirmed by Raman spectroscopy. Our method will permit experiments to determine the contributions of the different oxygen sites to the isotope effect, in order to locate the pairing interaction within the unit cell. C1 SANDIA NATL LABS,LIVERMORE,CA 94550. RP MORRIS, DE (reprint author), MORRIS RES,1918 UNIV AVE,BERKELEY,CA 94704, USA. RI McCarty, Kevin/F-9368-2012 OI McCarty, Kevin/0000-0002-8601-079X NR 14 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 0163-1829 J9 PHYS REV B JI Phys. Rev. B PD NOV 1 PY 1991 VL 44 IS 17 BP 9556 EP 9561 DI 10.1103/PhysRevB.44.9556 PG 6 WC Physics, Condensed Matter SC Physics GA GP267 UT WOS:A1991GP26700050 ER PT J AU XU, M ZHAO, ZX AF XU, M ZHAO, ZX TI EXPERIMENTAL-OBSERVATIONS OF ELECTRONIC-STRUCTURES FOR TERNARY METALLIC GLASSES OF (CU1-XNIX)33ZR67 SO PHYSICAL REVIEW B LA English DT Article ID CRITICAL FIELDS; SUPERCONDUCTIVITY; ALLOYS; TRANSPORT; STATES AB We have experimentally studied the electronic structures of ternary glassy metals of (Cu(1-x)Ni(x))33Zr67. The density of states at the Fermi level, N(0), has been estimated from measurements of the superconducting upper critical field. We have also measured the valence band, using x-ray photoemission spectroscopy. We found that the electronic structure is affected by the Ni concentration in ternary glassy metals of (Cu(1-x)Ni(x))33Zr67. Also discussed are relationships between the electronic structure and superconducting properties, detailed band structures including the bandwidth, the position of the subband, the intensity of spectrum, and various theoretical models. C1 CHINESE ACAD SCI,INST PHYS,BEIJING 100080,PEOPLES R CHINA. RP XU, M (reprint author), IOWA STATE UNIV SCI & TECHNOL,INST PHYS RES & TECHNOL,AMES LAB,AMES,IA 50011, USA. NR 21 TC 3 Z9 3 U1 0 U2 2 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 0163-1829 J9 PHYS REV B JI Phys. Rev. B PD NOV 1 PY 1991 VL 44 IS 17 BP 9652 EP 9655 DI 10.1103/PhysRevB.44.9652 PG 4 WC Physics, Condensed Matter SC Physics GA GP267 UT WOS:A1991GP26700060 ER PT J AU LIU, AY COHEN, ML AF LIU, AY COHEN, ML TI ELECTRON-PHONON COUPLING IN BCC AND 9R LITHIUM SO PHYSICAL REVIEW B LA English DT Article ID LOW-TEMPERATURE; ALKALI-METALS; PHASE AB We test the hypothesis that the observed absence of superconductivity in Li results from weak electron-phonon coupling in the low-temperature 9R phase. A first-principles study of the phonon spectrum and electron-phonon coupling constant in bcc and 9R Li is presented. The electron-phonon coupling constant is found to be similar in bcc and 9R Li, and in both phases it is too strong to be consistent with the experimental upper bound on the superconducting transition temperature within the standard theory of phonon-mediated superconductivity. C1 UNIV CALIF BERKELEY,DEPT PHYS,BERKELEY,CA 94720. UNIV CALIF BERKELEY,LAWRENCE BERKELEY LAB,DIV MAT SCI,BERKELEY,CA 94720. RI Liu, Amy/E-2266-2015 OI Liu, Amy/0000-0002-2011-1854 NR 24 TC 43 Z9 43 U1 0 U2 3 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 0163-1829 J9 PHYS REV B JI Phys. Rev. B PD NOV 1 PY 1991 VL 44 IS 17 BP 9678 EP 9684 DI 10.1103/PhysRevB.44.9678 PG 7 WC Physics, Condensed Matter SC Physics GA GP267 UT WOS:A1991GP26700063 ER PT J AU WEST, GW SEYMOUR, EFW CHANG, CT TORGESON, DR BARNES, RG AF WEST, GW SEYMOUR, EFW CHANG, CT TORGESON, DR BARNES, RG TI NMR EVIDENCE FOR A CHANGE IN LOCAL ELECTRONIC-STRUCTURE ACCOMPANYING HYDROGEN PAIRING IN YTTRIUM-HYDROGEN SOLID-SOLUTIONS SO PHYSICAL REVIEW B LA English DT Note ID CROSS-RELAXATION; PROTON; NMR; METAL; DEUTERIUM; SCANDIUM; MOTION; LOCATION; SYSTEMS; SPINS AB Measurements of the proton spin-lattice relaxation (SLR) rate in yttrium-hydrogen solid solutions (alpha-YH(x)) show that the hydrogen-pairing phenomenon, which occurs in the temperature range 170-300 K, is accompanied by a continuous, strong (22%) decrease in the Korringa parameter, R1e/T, with decreasing temperature, where R1e, is the conduction-electron contribution to the total SLR rate. This shows that a substantial (37%) change occurs in the product of the hyperfine field at the proton site and the local d-band density of states at the Fermi level, Nd(E(F)), when hydrogens become paired. Similar behavior has not been detected in the corresponding Sc-H and Lu-H systems in which pairing also occurs. C1 UNIV WARWICK,DEPT PHYS,COVENTRY CV4 7AL,W MIDLANDS,ENGLAND. IOWA STATE UNIV SCI & TECHNOL,AMES LAB,AMES,IA 50011. IOWA STATE UNIV SCI & TECHNOL,DEPT PHYS,AMES,IA 50011. RP WEST, GW (reprint author), CSIRO,DIV MAT SCI & TECHNOL,CLAYTON,VIC 3168,AUSTRALIA. NR 18 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 0163-1829 J9 PHYS REV B JI Phys. Rev. B PD NOV 1 PY 1991 VL 44 IS 17 BP 9692 EP 9695 DI 10.1103/PhysRevB.44.9692 PG 4 WC Physics, Condensed Matter SC Physics GA GP267 UT WOS:A1991GP26700065 ER PT J AU CHEONG, SW COOPER, AS RUPP, LW BATLOGG, B THOMPSON, JD FISK, Z AF CHEONG, SW COOPER, AS RUPP, LW BATLOGG, B THOMPSON, JD FISK, Z TI MAGNETIC DILUTION STUDY IN LA2CUO4 - COMPARISON WITH OTHER 2-DIMENSIONAL MAGNETS SO PHYSICAL REVIEW B LA English DT Note ID ANTIFERROMAGNETS; TEMPERATURE AB The reduction of the Neel point T(N) of La2CuO4 by substitution of nonmagnetic Mg or Zn for Cu has been studied, with particular emphasis on keeping the oxygen content unaffected. In the low-concentration range (less-than-or-similar-to 10%), the rate of T(N) suppression is found to be the same as in other two-dimensional (2D) Heisenberg magnets such as K2CuF4 (S = 1/2) and K2MnF4 (S = 5/2). While this suppression rate is larger than for 2D Ising magnets, it is much smaller than the rapid T(N) reduction upon introduction of holes in La2CuO4 through oxygen excess or heterovalent substitution for La. Thus, no unusual quantum magnetic dilution effects are observed in the S = 1/2 La2CuO4 magnet. C1 UNIV CALIF LOS ALAMOS SCI LAB,LOS ALAMOS,NM 87545. RP CHEONG, SW (reprint author), AT&T BELL LABS,MURRAY HILL,NJ 07974, USA. NR 20 TC 78 Z9 78 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 NOV 1 PY 1991 VL 44 IS 17 BP 9739 EP 9742 DI 10.1103/PhysRevB.44.9739 PG 4 WC Physics, Condensed Matter SC Physics GA GP267 UT WOS:A1991GP26700077 ER PT J AU NORTON, DP LOWNDES, DH ZHENG, XY ZHU, S WARMACK, RJ AF NORTON, DP LOWNDES, DH ZHENG, XY ZHU, S WARMACK, RJ TI SCANNING TUNNELING MICROSCOPY OF PULSED-LASER-DEPOSITED YBA2CU3O7-DELTA EPITAXIAL THIN-FILMS - SURFACE MICROSTRUCTURE AND GROWTH-MECHANISM SO PHYSICAL REVIEW B LA English DT Note ID YBA2CU3O7-X/PRBA2CU3O7-X SUPERLATTICES AB Scanning tunneling microscopy suggests that epitaxial YBa2Cu3O7-delta thin films grow unit cell by unit cell, by a terraced-island-growth mode. Although films grown at low temperatures exhibit a spiral-growth surface microstructure, films with high critical current densities (grown at high temperatures on nearly-lattice-matched substrates) do not. The terraced microstructure explains the steps found in ultrathin YBa2Cu3O7-delta layers in YBa2Cu3O7-delta/PrBa2Cu3O7-delta superlattices. These steps may act as superconducting weak links, providing support for Josephson-coupled-array models of superconducting superlattices. C1 OAK RIDGE NATL LAB,DIV HLTH & SAFETY RES,OAK RIDGE,TN 37831. UNIV TENNESSEE,DEPT PHYS & ASTRON,KNOXVILLE,TN 37996. RP NORTON, DP (reprint author), OAK RIDGE NATL LAB,DIV SOLID STATE,POB 2008,OAK RIDGE,TN 37831, USA. NR 19 TC 65 Z9 65 U1 0 U2 1 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 0163-1829 J9 PHYS REV B JI Phys. Rev. B PD NOV 1 PY 1991 VL 44 IS 17 BP 9760 EP 9763 DI 10.1103/PhysRevB.44.9760 PG 4 WC Physics, Condensed Matter SC Physics GA GP267 UT WOS:A1991GP26700083 ER PT J AU HOOD, RQ FALICOV, LM AF HOOD, RQ FALICOV, LM TI ITINERANT-ELECTRON, ONE-DIMENSIONAL MAGNETIC SUPERLATTICES SO PHYSICAL REVIEW B LA English DT Article ID MAGNETORESISTANCE AB Self-consistent Hartree-Fock calculations are presented for a variety of heterogeneous systems consisting of one-dimensional arrays of itinerant paramagnets, ferromagnets, and antiferromagnets. Several aspects of the multilayers and interfaces are explored: enhancement and reduction of the local magnetic moments, magnetic coupling at the interfaces, magnetic arrangements within each film and among non-neighboring films, the global symmetry of the systems, frustration, orientation of the various moments with respect to an outside applied field, and magnetic-field-induced transitions. The various situations exhibit a rich structure and a wealth of possible magnetic effects. C1 UNIV CALIF BERKELEY,LAWRENCE BERKELEY LAB,DIV MAT SCI,BERKELEY,CA 94720. RP HOOD, RQ (reprint author), UNIV CALIF BERKELEY,DEPT PHYS,BERKELEY,CA 94720, USA. NR 13 TC 6 Z9 6 U1 1 U2 1 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 0163-1829 J9 PHYS REV B JI Phys. Rev. B PD NOV 1 PY 1991 VL 44 IS 18 BP 9989 EP 9996 DI 10.1103/PhysRevB.44.9989 PG 8 WC Physics, Condensed Matter SC Physics GA GP268 UT WOS:A1991GP26800020 ER PT J AU KIOUSSIS, N COOPER, BR WILLS, JM AF KIOUSSIS, N COOPER, BR WILLS, JM TI MAGNETIC INSTABILITY WITH INCREASING HYBRIDIZATION IN CERIUM COMPOUNDS SO PHYSICAL REVIEW B LA English DT Article ID ORBITALLY-DRIVEN MAGNETISM; CESB1-XTEX SOLID-SOLUTIONS; ACTINIDE SYSTEMS; PHOTOEMISSION SPECTRA; 2-PEAK PHOTOEMISSION; CE COMPOUNDS; MODEL; MECHANISM; BAND; MONOCHALCOGENIDES AB A synthesis of a phenomenological theory of orbitally driven magnetic ordering of moderately delocalized light rare-earth systems and ab initio electronic structure calculations has been applied to investigate the change in magnetic behavior on going from CeSb to CeTe, both of which have rocksalt structure with a small decrease in lattice parameter. The hybridization-potential matrix elements and the band energies entering the Anderson-lattice Hamiltonian are obtained from linear-muffin-tin-orbital (LMTO) electronic-structure calculations with the Ce 4f states treated as core states. The position of the Ce 4f energy level relative to the Fermi energy and the intra-atomic Coulomb energy U are obtained by use of a sequence of three total-energy supercell calculations with one out of four Ce sites constrained to f(n) occupation with n = 0, 1, 2, successively. The calculations elucidate the origins, in the electronic structure, of the variation of the f-state resonance width and hybridization potential on going from CeSb to CeTe, and the resultant sensitivity of the hybridization dressing of the crystal-field splitting and the hybridization-induced exchange interactions to chemical environment. The effect of opening up successive angular momentum scattering channels of the ab initio calculated two-ion exchange-interaction matrix on the nature of the magnetic ordering is examined. The calculated magnitude and range dependence of the two-ion exchange interactions changes sharply from CeSb to CeTe, yielding a change in magnetic behavior in qualitative agreement with experiment. The nonlinear hybridization effects on the hybridization dressing of the crystal-field splitting have been examined. These effects, which are associated with the self-consistent determination of both the band states and f states in the presence of band-f hybridization, are found to be small in both systems. C1 W VIRGINIA UNIV,DEPT PHYS,MORGANTOWN,WV 26506. UNIV CALIF LOS ALAMOS SCI LAB,LOS ALAMOS,NM 87544. RP KIOUSSIS, N (reprint author), CALIF STATE UNIV NORTHRIDGE,DEPT PHYS,NORTHRIDGE,CA 91330, USA. NR 48 TC 29 Z9 29 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 NOV 1 PY 1991 VL 44 IS 18 BP 10003 EP 10013 DI 10.1103/PhysRevB.44.10003 PG 11 WC Physics, Condensed Matter SC Physics GA GP268 UT WOS:A1991GP26800022 ER PT J AU VOLKEL, AR WYSIN, GM BISHOP, AR MERTENS, FG AF VOLKEL, AR WYSIN, GM BISHOP, AR MERTENS, FG TI DYNAMIC CORRELATIONS IN THE CLASSICAL 2-DIMENSIONAL ANTIFERROMAGNETIC HEISENBERG-MODEL WITH EASY-PLANE SYMMETRY SO PHYSICAL REVIEW B LA English DT Article ID KOSTERLITZ-THOULESS TRANSITION; XY MODEL; FERROMAGNETS; VORTICES; RB2CRCL4; SYSTEMS; MAGNETS AB We investigate the dynamics of the two-dimensional antiferromagnetic Heisenberg model with easy-plane exchange symmetry. We develop a phenomenology of spin-wave and vortex excitations and calculate their contributions to the dynamical correlation functions S(alpha-alpha)(q, omega), alpha = x, y, z. The vortex shape depends explicitly on an exchange anisotropy parameter lambda and changes from a mainly in-plane structure below a critical lambda-c to a shape with well-established z components around the vortex center above lambda-c. In this paper we will discuss only the case lambda < lambda-c, where the system behaves almost like the pure XY model. The general properties of the dynamical behavior of the spin waves and vortices below the Kosterlitz-Thouless transition temperature T(KT) have been widely examined for the ferromagnetic XY model, and do not change much in the antiferromagnet (although here we have two magnon branches according to the two different spin sublattices). Our main interest is focused on the unbound vortices just above T(KT) Assuming a dilute gas of ballistically moving vortices, we obtain central peaks in S(alpha-alpha)(q, omega) similar to the ferromagnetic case, but in some cases at different positions in q space depending on whether the static vortex structure or the deviation from it due to a finite velocity dominates the correlations. These results are compared with a combined Monte Carlo-molecular-dynamics simulation on a 100 X 100 square lattice. The phenomenological predictions for the correlation functions and the integrated intensities describe the numerical results quite well and, by comparing both methods, we obtain values for the vortex correlation length, which are in good agreement with the Kosterlitz-Thouless theory. C1 UNIV CALIF LOS ALAMOS SCI LAB,CTR NONLINEAR STUDIES,LOS ALAMOS,NM 87545. KANSAS STATE UNIV AGR & APPL SCI,DEPT PHYS,MANHATTAN,KS 66506. UNIV BAYREUTH,INST PHYS,W-8580 BAYREUTH,GERMANY. RP VOLKEL, AR (reprint author), UNIV CALIF LOS ALAMOS SCI LAB,DIV THEORET,LOS ALAMOS,NM 87545, USA. RI Wysin, Gary/I-8162-2012 OI Wysin, Gary/0000-0001-8422-800X NR 31 TC 25 Z9 25 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 NOV 1 PY 1991 VL 44 IS 18 BP 10066 EP 10078 DI 10.1103/PhysRevB.44.10066 PG 13 WC Physics, Condensed Matter SC Physics GA GP268 UT WOS:A1991GP26800029 ER PT J AU COFFEY, D RICE, TM ZHANG, FC AF COFFEY, D RICE, TM ZHANG, FC TI DZYALOSHINSKII-MORIYA INTERACTION IN THE CUPRATES SO PHYSICAL REVIEW B LA English DT Article ID HUBBARD-MODEL; LA2CUO4; SUPERCONDUCTIVITY; METAMAGNETISM AB The Dzyaloshinskii-Moriya interaction, which arises from a mixture of superexchange and spin-orbit coupling NN Cu2+ spin with a term of the D(ij).(S(i) X S(j)). The coupling constants D(ij) are estimated for several cuprate crystal structures. The pattern of the D(ij) varies considerably between these structures and only in some cases causes a weak ferromagnetic component in an ordered antiferromagnetic of the Cu spins. In no case, however, does this interaction stabilize a flux phase. C1 SWISS FED INST TECHNOL,CH-8093 ZURICH,SWITZERLAND. UNIV CINCINNATI,DEPT PHYS,CINCINNATI,OH 45221. RP COFFEY, D (reprint author), UNIV CALIF LOS ALAMOS SCI LAB,LOS ALAMOS,NM 87545, USA. NR 22 TC 87 Z9 87 U1 3 U2 24 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 0163-1829 J9 PHYS REV B JI Phys. Rev. B PD NOV 1 PY 1991 VL 44 IS 18 BP 10112 EP 10116 DI 10.1103/PhysRevB.44.10112 PG 5 WC Physics, Condensed Matter SC Physics GA GP268 UT WOS:A1991GP26800034 ER PT J AU NAVARRO, R CAMPBELL, LJ AF NAVARRO, R CAMPBELL, LJ TI MAGNETIC-FLUX PROFILES OF HIGH-TC SUPERCONDUCTING GRANULES - 3-DIMENSIONAL CRITICAL-STATE-MODEL APPROXIMATION SO PHYSICAL REVIEW B LA English DT Article ID II SUPERCONDUCTORS; HARD SUPERCONDUCTORS; CRITICAL CURRENTS; BEAN MODEL; FIELD; SUSCEPTIBILITY; PENETRATION; WIRE; DISK; KIM AB Magnetic-flux penetration of high-T(c) superconducting (HTS) granules in three dimensions is modeled using spheres and spheroids within the critical-state theory. Numerical approximations for the simplest Bean-London model overlap analytic results in the limits of small and full penetration. Examples for flux contours, initial magnetization, and magnetic hysteresis loops are calculated for the complete range of flux penetration. These results are compared with the solutions for slabs and cylinders so far used in the study of HTS materials. The differences in the flux profiles found for oblate spheroids indicate the inaccuracy of using other geometries in the analysis of HTS flakelike grains. C1 UNIV ZARAGOZA,CSIC,INST CIENCIA MAT ARAGON,E-50009 ZARAGOZA,SPAIN. RP NAVARRO, R (reprint author), UNIV CALIF LOS ALAMOS SCI LAB,DIV THEORET,LOS ALAMOS,NM 87545, USA. NR 38 TC 29 Z9 29 U1 0 U2 4 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 0163-1829 J9 PHYS REV B JI Phys. Rev. B PD NOV 1 PY 1991 VL 44 IS 18 BP 10146 EP 10157 DI 10.1103/PhysRevB.44.10146 PG 12 WC Physics, Condensed Matter SC Physics GA GP268 UT WOS:A1991GP26800039 ER PT J AU BULAEVSKII, L CLEM, JR AF BULAEVSKII, L CLEM, JR TI VORTEX LATTICE OF HIGHLY ANISOTROPIC LAYERED SUPERCONDUCTORS IN STRONG, PARALLEL MAGNETIC-FIELDS SO PHYSICAL REVIEW B LA English DT Article ID SPATIALLY MODULATED CONCENTRATION; ALLOYS AB The equations for the gauge-invariant phases obtained in the framework of the Lawrence-Doniach model are used to study the vortex lattice in layered superconductors in strong, parallel magnetic fields H. As H changes, a sequence of first-order phase transitions occurs between the lattices with different periods. The largest jumps in magnetization, of order H(cl), occur at fields of order H0 = phi-0/gamma-s2, where phi-0 is the flux quantum, s is the interlayer spacing, and gamma is the anisotropy (gamma = lambda-c/lambda-ab, where lambda-c and lambda-ab are the penetration depths for currents perpendicular and parallel to the layers, respectively). The asymptotic dependence of the magnetization M at high fields H >> H0 is M is-proportional-to H(-3). C1 IOWA STATE UNIV SCI & TECHNOL,DEPT PHYS & ASTRON,AMES,IA 50011. PN LEBEDEV PHYS INST,MOSCOW,USSR. RP BULAEVSKII, L (reprint author), IOWA STATE UNIV SCI & TECHNOL,AMES LAB,AMES,IA 50011, USA. NR 19 TC 174 Z9 175 U1 0 U2 1 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 0163-1829 J9 PHYS REV B JI Phys. Rev. B PD NOV 1 PY 1991 VL 44 IS 18 BP 10234 EP 10238 DI 10.1103/PhysRevB.44.10234 PG 5 WC Physics, Condensed Matter SC Physics GA GP268 UT WOS:A1991GP26800049 ER PT J AU ZHOU, Y FEDRO, AJ BOWEN, SP KOELLING, DD LEUNG, TC HARMON, BN SINHA, SK AF ZHOU, Y FEDRO, AJ BOWEN, SP KOELLING, DD LEUNG, TC HARMON, BN SINHA, SK TI QUASI-PARTICLE BANDS OF THE 2-DIMENSIONAL HUBBARD-MODEL SO PHYSICAL REVIEW B LA English DT Article ID MEAN-FIELD-THEORY AB We present a mean-field calculation of the two-dimensional single-band Hubbard model based on a Mori-projection-operator formalism. Various physical properties including the energy, effective hopping matrix clement, local moment, momentum distribution function, and Fermi surface are calculated. The results are compared with those of the Hubbard-I approximation, the four-boson mean-field theory of Kotliar and Rockenstein (SBMF), and quantum Monte Carlo simulations. Systematic improvement over the Hubbard-I approximation is seen, and good agreements are obtained between our calculation and the SBMF theory. C1 IOWA STATE UNIV SCI & TECHNOL,DEPT PHYS,AMES LAB,AMES,IA 50011. EXXON RES & ENGN CO,CORP RES,ANNANDALE,NJ 08801. NO ILLINOIS UNIV,DEPT PHYS,DE KALB,IL 60115. RP ZHOU, Y (reprint author), ARGONNE NATL LAB,ARGONNE,IL 60439, USA. NR 20 TC 8 Z9 8 U1 0 U2 0 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 0163-1829 J9 PHYS REV B JI Phys. Rev. B PD NOV 1 PY 1991 VL 44 IS 18 BP 10291 EP 10295 DI 10.1103/PhysRevB.44.10291 PG 5 WC Physics, Condensed Matter SC Physics GA GP268 UT WOS:A1991GP26800056 ER PT J AU ANDRAKA, B STEWART, GR FISK, Z AF ANDRAKA, B STEWART, GR FISK, Z TI LOW-TEMPERATURE ANOMALIES IN THE HIGH-FIELD SPECIFIC-HEAT OF UCD11 SO PHYSICAL REVIEW B LA English DT Note ID FERMION SYSTEMS; ELECTRON SYSTEM; GROUND-STATE AB The specific heat of UCd11 has been investigated in magnetic fields up to 16 T and in the temperature range 0.35-10 K. In addition to the well-known 5-K magnetic transition, another anomaly is observed below 2 K in fields larger than 10 T. This anomaly can be related to the previously reported signature in the temperature-dependent resistivity under pressure. Furthermore, the magnetic fields do not affect the high-temperature specific heat (above the 5-K transition). The latter observation is discussed in relation to the origin of the extremely large electronic effective mass of UCd11. C1 UNIV AUGSBURG,W-8900 AUGSBURG,GERMANY. UNIV CALIF LOS ALAMOS SCI LAB,LOS ALAMOS,NM 87545. RP ANDRAKA, B (reprint author), UNIV FLORIDA,DEPT PHYS,GAINESVILLE,FL 32611, USA. NR 17 TC 8 Z9 8 U1 0 U2 1 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 0163-1829 J9 PHYS REV B JI Phys. Rev. B PD NOV 1 PY 1991 VL 44 IS 18 BP 10346 EP 10349 DI 10.1103/PhysRevB.44.10346 PG 4 WC Physics, Condensed Matter SC Physics GA GP268 UT WOS:A1991GP26800064 ER PT J AU ELSASSER, C HO, KM CHAN, CT FAHNLE, M AF ELSASSER, C HO, KM CHAN, CT FAHNLE, M TI VIBRATIONAL-STATES FOR HYDROGEN IN PALLADIUM SO PHYSICAL REVIEW B LA English DT Note ID NORM-CONSERVING PSEUDOPOTENTIALS; QUANTUM-MECHANICAL CALCULATIONS; ELECTRONIC-STRUCTURE; METALS; DIFFUSION; SOLIDS; PD; FORMALISM; TANTALUM; NIOBIUM AB Vibrational potentials for hydrogen isotopes in PdH and Pd4H are determined from first-principles total-energy calculations. The strong anharmonicity of the potential for H around octahedral sites must be taken into account beyond perturbation theory. For PdH good quantitative agreement of our calculated vibration energies with inelastic-neutron-scattering (INS) results is achieved, allowing a reinterpretation of the INS spectra. For lower H concentrations (Pd(n)H, n = 4, 8, 16, and 32) the influence of local lattice relaxations on the vibration potentials and energies is important. Furthermore, metastable states confined to tetrahedral sites in Pd are found for the heavier isotopes 2D and 3T. C1 IOWA STATE UNIV SCI & TECHNOL,AMES LAB,AMES,IA 50011. IOWA STATE UNIV SCI & TECHNOL,DEPT PHYS,AMES,IA 50011. RP ELSASSER, C (reprint author), MAX PLANCK INST MET RES,INST PHYS,HEISENBERGSTR 1,W-7000 STUTTGART 80,GERMANY. NR 30 TC 38 Z9 38 U1 1 U2 13 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 0163-1829 J9 PHYS REV B JI Phys. Rev. B PD NOV 1 PY 1991 VL 44 IS 18 BP 10377 EP 10380 DI 10.1103/PhysRevB.44.10377 PG 4 WC Physics, Condensed Matter SC Physics GA GP268 UT WOS:A1991GP26800074 ER PT J AU LEYBA, JD HENDERSON, RA HALL, HL CZERWINSKI, KR KADKHODAYAN, BA KREEK, SA BRADY, EK GREGORICH, KE LEE, DM NURMIA, MJ HOFFMAN, DC AF LEYBA, JD HENDERSON, RA HALL, HL CZERWINSKI, KR KADKHODAYAN, BA KREEK, SA BRADY, EK GREGORICH, KE LEE, DM NURMIA, MJ HOFFMAN, DC TI EXCITATION-FUNCTIONS FOR ACTINIDES PRODUCED IN THE INTERACTIONS OF P-31 WITH CM-248 SO PHYSICAL REVIEW C LA English DT Article ID TRANSFER-INDUCED TRANSPORT; HEAVY ACTINIDES; NUCLEAR AB Excitation functions have been measured for the production of various isotopes of Bk, Cf, Es, and Fm from the interactions of 174- and 239-MeV P-31 projectiles with Cm-248. The isotopic distributions were symmetric and displayed full widths at half maximum of 2.5, 2.5, and 2.25 mass units for Bk, Cf, and Fm, respectively. The maxima of the isotopic distributions occur for those reaction channels which involve the exchange of the fewest number of nucleons between the target and projectile for which the calculated excitation energy is a positive quantity. The maxima of the excitation functions occur at those projectile energies which are consistent with the calculated reaction barriers based upon a binary reaction mechanism. The effects of the odd proton in the P-31 projectile on the final isotopic distributions are discussed. C1 UNIV CALIF BERKELEY,LAWRENCE BERKELEY LAB,DIV NUCL SCI,BERKELEY,CA 94720. RP LEYBA, JD (reprint author), UNIV CALIF BERKELEY,DEPT CHEM,BERKELEY,CA 94720, USA. OI Hall, Howard/0000-0002-4080-5159 NR 24 TC 3 Z9 3 U1 0 U2 1 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 0556-2813 J9 PHYS REV C JI Phys. Rev. C PD NOV PY 1991 VL 44 IS 5 BP 1850 EP 1861 DI 10.1103/PhysRevC.44.1850 PG 12 WC Physics, Nuclear SC Physics GA GP735 UT WOS:A1991GP73500014 ER PT J AU OLSON, DL BAUMGARTNER, M GREINER, DE LINDSTROM, PJ SYMONS, TJM WADA, R WEBB, ML BERMAN, BL CRAWFORD, HJ ENGELAGE, JM AF OLSON, DL BAUMGARTNER, M GREINER, DE LINDSTROM, PJ SYMONS, TJM WADA, R WEBB, ML BERMAN, BL CRAWFORD, HJ ENGELAGE, JM TI DIRECT OBSERVATION OF THE GIANT-DIPOLE RESONANCE OF O-16 VIA ELECTROMAGNETIC DISSOCIATION SO PHYSICAL REVIEW C LA English DT Article ID FRAGMENTATION CROSS-SECTIONS; RELATIVISTIC HEAVY-IONS; AU-197 TARGETS; GEV NUCLEON; CO-59; PROJECTILES; COLLISIONS; EMISSION; SI-28; RADII AB We have measured the invariant-mass spectrum of the final-state N-15+p system in the reaction T(O-16,N-15+p)X at 2.1A GeV with Be, Cu, and U targets (T). Electromagnetic dissociation of the O-16 projectile nucleus in the Coulomb field of the target nucleus produces two prominent peaks in the proton-energy spectrum, one at 9 MeV, from transitions to the ground state of the residual N-15 nucleus, and the other at 4 MeV, from transitions to excited states. This is corroborated by gamma rays corresponding to the deexcitation of the N-15 nucleus which are in coincidence with the 4-MeV peak and are suppressed for the 9-MeV peak. Nucleon-nucleus diffractive dissociation makes a significant contribution to the cross section and results in a peak at 1.5 MeV. Nucleon-nucleon quasielastic scattering results in a featureless high-energy tail above 20 MeV. C1 GEORGE WASHINGTON UNIV,CTR NUCL STUDIES,WASHINGTON,DC 20052. UNIV CALIF BERKELEY,SPACE SCI LAB,BERKELEY,CA 94720. RP OLSON, DL (reprint author), UNIV CALIF BERKELEY,LAWRENCE BERKELEY LAB,BERKELEY,CA 94720, USA. NR 28 TC 9 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 NOV PY 1991 VL 44 IS 5 BP 1862 EP 1867 DI 10.1103/PhysRevC.44.1862 PG 6 WC Physics, Nuclear SC Physics GA GP735 UT WOS:A1991GP73500015 ER PT J AU TOTH, KS VIERINEN, KS KORTELAHTI, MO SOUSA, DC NITSCHKE, JM WILMARTH, PA AF TOTH, KS VIERINEN, KS KORTELAHTI, MO SOUSA, DC NITSCHKE, JM WILMARTH, PA TI INVESTIGATION OF A = 155 AND A = 151 NUCLIDES - IDENTIFICATION OF THE TM-155 S1/2 ISOMER AND OF THE YB-155 BETA-DECAY BRANCH SO PHYSICAL REVIEW C LA English DT Article ID ALPHA-DECAY; NUCLEI; ENERGIES; ISOTOPES; STATES; RATIOS AB The decay properties of 155Lu, 155Yb, 155Tm, and of the alpha-decay daughters 151Er and 151Ho were investigated following the on-line mass separation of A = 155 nuclides produced in Zn-64 irradiations of Mo-95. In the study, the half-life of the low-spin isomer in 155Lu was measured to be 140 +/- 20 ms, the beta-decay branch of 155Yb was identified by observing daughter gamma rays and Tm K x rays, and the existence in 155Tm of an s1/2 isomer (T1/2 = 44 +/- 4 s), in addition to the h11/2 ground state (T1/2 = 21.6 +/- 0.2 s) was established. Schemes for the beta decays of 155Yb, 155Tm, and 151Er are proposed. New information on 151Er decay establishes the s1/2 isomer in 151Ho to be 41.1 +/- 0.2 keV above the h11/2 ground state. Also, branchings of 90 +/- 5, 28 +/- 7, and 80(-20)+15% were determined for the alpha decays of 155Yb, 151Ho, and 151Ho(m), respectively. C1 UNIV CALIF BERKELEY,LAWRENCE BERKELEY LAB,BERKELEY,CA 94720. LOUISIANA STATE UNIV,BATON ROUGE,LA 70803. RP TOTH, KS (reprint author), OAK RIDGE NATL LAB,OAK RIDGE,TN 37831, USA. NR 29 TC 18 Z9 18 U1 0 U2 0 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 0556-2813 J9 PHYS REV C JI Phys. Rev. C PD NOV PY 1991 VL 44 IS 5 BP 1868 EP 1877 DI 10.1103/PhysRevC.44.1868 PG 10 WC Physics, Nuclear SC Physics GA GP735 UT WOS:A1991GP73500016 ER PT J AU DOVER, CB MILLENER, DJ GAL, A DAVIS, DH AF DOVER, CB MILLENER, DJ GAL, A DAVIS, DH TI INTERPRETATION OF A DOUBLE HYPERNUCLEUS EVENT SO PHYSICAL REVIEW C LA English DT Article ID BARYON-BARYON SCATTERING; EXCHANGE-POTENTIAL APPROACH; HYPERON HYPERON INTERACTION; NUCLEON-NUCLEON; LAMBDA-HYPERNUCLEI; MODEL; DIHYPERON; ENERGY AB Arguments are put forward to suggest that a double hypernucleus event, recently reported by Aoki et al. as either Be-10-LAMBDA-LAMBDA or B-13-LAMBDA-LAMBDA, should be interpreted as B-13-LAMBDA-LAMBDA. It is proposed that the formation of B-13-LAMBDA-LAMBDA occurs sequentially via an intermediate excited state of C-14-LAMBDA-LAMBDA, which decays by proton emission: XI- + N-14 --> n + C-14-LAMBDA-LAMBDA*, C-14-LAMBDA-LAMBDA* --> p + B-13-LAMBDA-LAMBDA. Moreover, it is shown that particular excited states are favored in the XI- hyperon capture process. The binding energy of the two LAMBDA hyperons in B-13-LAMBDA-LAMBDA is B-LAMBDA-LAMBDA = 27.5 + 0.7 MeV, corresponding to an attractive S-LAMBDA-2 matrix element DELTA-B-LAMBDA-LAMBDA = 4.8 +/- 0.7 MeV, in good agreement with values of DELTA-B-LAMBDA-LAMBDA obtained from previous events. C1 HEBREW UNIV JERUSALEM,RACAH INST PHYS,IL-91904 JERUSALEM,ISRAEL. UNIV LONDON UNIV COLL,DEPT PHYS & ASTRON,LONDON WC1E 6BT,ENGLAND. RP DOVER, CB (reprint author), BROOKHAVEN NATL LAB,DEPT PHYS,UPTON,NY 11973, USA. NR 27 TC 119 Z9 119 U1 0 U2 0 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 0556-2813 J9 PHYS REV C JI Phys. Rev. C PD NOV PY 1991 VL 44 IS 5 BP 1905 EP 1909 DI 10.1103/PhysRevC.44.1905 PG 5 WC Physics, Nuclear SC Physics GA GP735 UT WOS:A1991GP73500021 ER PT J AU ROBERTS, ML FELSHER, PD WEISEL, GJ CHEN, ZM HOWELL, CR TORNOW, W WALTER, RL HOREN, DJ AF ROBERTS, ML FELSHER, PD WEISEL, GJ CHEN, ZM HOWELL, CR TORNOW, W WALTER, RL HOREN, DJ TI MEASUREMENT OF AY(THETA) FOR N+PB-208 FROM 6 TO 10 MEV AND THE NEUTRON-NUCLEUS INTERACTION OVER THE ENERGY-RANGE FROM BOUND-STATES AT -17 MEV UP TO SCATTERING AT 40 MEV SO PHYSICAL REVIEW C LA English DT Article ID OPTICAL-MODEL ANALYSIS; ANALYZING POWER; MEAN FIELD; PB-208; POLARIZATION; PREDICTIONS; DEPENDENCE; THRESHOLD; FE-54; CU-65 AB High-accuracy measurements of A(y)(theta) data for elastic scattering and inelastic scattering to the first excited state for n + Pb-208 have been performed at 6, 7, 8, 9, and 10 MeV. In addition, sigma(theta) was measured at 8 MeV. These data provide an important subset for the growing database for the n + Pb-208 system from bound-state energies to energies above 40 MeV, the limit of the range of interest here. This database has been interpreted via several approaches. First, a conventional Woods-Saxon spherical optical was used to obtain three potential representations for the energy range from 4 to 40 MeV: "best fits" at each energy, constant-geometry global fit with linear energy dependences for the potential strengths for the range 4.0-40 MeV, and an extension of the latter model to allow a linear energy dependence on the radii and diffuseness. A preference for a complex spin-orbit interaction was observed in all cases. Second, the dispersion relation was introduced into the spherical optical model to obtain a more "realistic" representation. In our approach, the strength and shape of the real potential was modified by calculating the dispersion-relation contributions that originate from the presence of the surface and volume imaginary terms. Two potentials were developed, one based only on the scattering data (from 4.0 to 40 MeV) and another based additionally on single-particle and single-hole information down to a binding energy of 17 MeV. In addition, the sigma(theta) and A(y)(theta) measurements were compared to earlier conventional and dispersion-relation models. One of the latter of these included an l dependence in the absorptive surface term, and we applied this model in the 6- to 10-MeV region to describe all the sigma(theta) and the new A(y)(theta). A reasonably good overall description was obtained by all the models; however, only the l-dependent model came close to giving a detailed agreement to the data around 7 MeV, a region where some abnormal angular dependences occur in the data. C1 DUKE UNIV,DEPT PHYS,DURHAM,NC 27706. DUKE UNIV,TRIANGLE UNIV NUCL LAB,DURHAM,NC 27706. OAK RIDGE NATL LAB,OAK RIDGE,TN 37831. NR 31 TC 26 Z9 27 U1 0 U2 1 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 0556-2813 J9 PHYS REV C JI Phys. Rev. C PD NOV PY 1991 VL 44 IS 5 BP 2006 EP 2024 DI 10.1103/PhysRevC.44.2006 PG 19 WC Physics, Nuclear SC Physics GA GP735 UT WOS:A1991GP73500033 ER PT J AU WILLIAMS, AL JOHNSON, KW KAHRIMANIS, GP WARD, H MOORE, CF MCGILL, JA MORRIS, CL BURLESON, GR FAUCETT, JA RAWOOLSULLIVAN, M OAKLEY, DS BURLEIN, M FORTUNE, HT INSKO, E IVIE, R ODONNELL, JM SMITH, D AF WILLIAMS, AL JOHNSON, KW KAHRIMANIS, GP WARD, H MOORE, CF MCGILL, JA MORRIS, CL BURLESON, GR FAUCETT, JA RAWOOLSULLIVAN, M OAKLEY, DS BURLEIN, M FORTUNE, HT INSKO, E IVIE, R ODONNELL, JM SMITH, D TI MASS DEPENDENCE OF HIGH-ENERGY PION DOUBLE CHARGE-EXCHANGE SO PHYSICAL REVIEW C LA English DT Article ID NUCLEAR SHELL-MODEL; RESONANCE REGION AB The mass dependence of cross sections for double-isobaric-analog states from pion-induced double-charge-exchange reactions is examined with small-angle data taken at 450 and 500 MeV incident pion energies for several targets. New (pi+, pi-) cross sections are reported for Mg-26, Ti-46, Ti-50, Fe-54, Fe-56, Cr-52, Se-80, Zr-90, Au-197, and Pb-208. The (f7/2)n data are fitted to a two-amplitude model which contains expressions for cross sections for transitions to the DIAS and to nonanalog ground states in the residual nucleus. C1 UNIV CALIF LOS ALAMOS SCI LAB,LOS ALAMOS,NM 87545. NEW MEXICO STATE UNIV,LAS CRUCES,NM 88003. UNIV COLORADO,BOULDER,CO 80309. UNIV PENN,PHILADELPHIA,PA 19104. RP WILLIAMS, AL (reprint author), UNIV TEXAS,AUSTIN,TX 78712, USA. NR 22 TC 6 Z9 6 U1 0 U2 0 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 0556-2813 J9 PHYS REV C JI Phys. Rev. C PD NOV PY 1991 VL 44 IS 5 BP 2025 EP 2030 DI 10.1103/PhysRevC.44.2025 PG 6 WC Physics, Nuclear SC Physics GA GP735 UT WOS:A1991GP73500034 ER PT J AU BRINKMOLLER, B BLILIE, CL DEHNHARD, D JONES, MK MARTINEZ, GM NANDA, SK STERBENZ, SM YEN, YF ATENCIO, LG GREENE, SJ MORRIS, CL SEESTROM, SJ BURLESON, GR DHUGA, KS FAUCETT, JA GARNETT, RW MAEDA, K MOORE, CF MORDECHAI, S WILLIAMS, A YOO, SH BLAND, LC AF BRINKMOLLER, B BLILIE, CL DEHNHARD, D JONES, MK MARTINEZ, GM NANDA, SK STERBENZ, SM YEN, YF ATENCIO, LG GREENE, SJ MORRIS, CL SEESTROM, SJ BURLESON, GR DHUGA, KS FAUCETT, JA GARNETT, RW MAEDA, K MOORE, CF MORDECHAI, S WILLIAMS, A YOO, SH BLAND, LC TI ELASTIC-SCATTERING OF PI+ AND PI- FROM HE-4 BETWEEN 90 AND 240 MEV SO PHYSICAL REVIEW C LA English DT Article ID PHASE-SHIFT ANALYSIS; NUCLEUS SCATTERING; 3,3 RESONANCE; HELIUM; PIONS AB In a series of experiments, differential cross sections for elastic scattering of pi+ and pi- from He-4 were measured at the Clinton P. Anderson Meson Physics Facility (LAMPF). Data were taken at incident energies between T-pi = 90 and 240 MeV using different experimental setups which covered the angular range from far forward (almost-equal-to 10-degrees) to far backward angles (almost-equal-to 170-degrees). A phase-shift analysis of the data was carried out. The experimental phase shifts are compared with values predicted by a first-order optical model program. C1 UNIV MINNESOTA,MINNEAPOLIS,MN 55455. UNIV CALIF LOS ALAMOS SCI LAB,LOS ALAMOS,NM 87545. NEW MEXICO STATE UNIV,LAS CRUCES,NM 88003. TOHOKU UNIV,SENDAI,MIYAGI 980,JAPAN. UNIV TEXAS,AUSTIN,TX 78712. UNIV PENN,PHILADELPHIA,PA 19104. BEN GURION UNIV NEGEV,IL-84105 BEER SHEVA,ISRAEL. NR 39 TC 18 Z9 19 U1 0 U2 1 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 0556-2813 J9 PHYS REV C JI Phys. Rev. C PD NOV PY 1991 VL 44 IS 5 BP 2031 EP 2040 DI 10.1103/PhysRevC.44.2031 PG 10 WC Physics, Nuclear SC Physics GA GP735 UT WOS:A1991GP73500035 ER PT J AU CHEN, XY SHEPARD, JR BRAUNSTEIN, MR CAREY, TA JONES, KW MCCLELLAND, JB REES, L TADDEUCCI, TN TANAKA, N BACHER, AD AF CHEN, XY SHEPARD, JR BRAUNSTEIN, MR CAREY, TA JONES, KW MCCLELLAND, JB REES, L TADDEUCCI, TN TANAKA, N BACHER, AD TI COMPLETE SPIN-TRANSFER MEASUREMENTS FOR INELASTIC POLARIZED PROTON-SCATTERING FROM C-12 SO PHYSICAL REVIEW C LA English DT Article ID WAVE IMPULSE APPROXIMATION; INTERMEDIATE ENERGIES; ELECTRON-SCATTERING; ELASTIC-SCATTERING; 500-MEV PROTONS; OBSERVABLES; CA-40; ENHANCEMENT; EXCITATION; PARAMETERS AB Complete spin-transfer observables for the two lowest 1+ levels in C-12 have been studied with incident protons of 500 MeV. Outgoing protons were detected with an energy resolution of 120 keV at laboratory angles of 3.5-degrees, 5.0-degrees, 7.5-degrees, 9.5-degrees, and 12.5-degrees. Angular distributions of differential cross sections, analyzing powers, and the individual spin observables for each 1+ state are recombined into three transverse and one longitudinal partial differential cross section as well as the spin-sum and spin-difference functions. Results are compared with model calculations and electron-scattering data. Information about experimental quantities not accessible in electron scattering is also discussed. C1 UNIV CALIF LOS ALAMOS SCI LAB,LOS ALAMOS,NM 87545. INDIANA UNIV,CYCLOTRON FACIL,BLOOMINGTON,IN 47405. RP CHEN, XY (reprint author), UNIV COLORADO,DEPT PHYS,NUCL PHYS LAB,BOULDER,CO 80309, USA. NR 30 TC 6 Z9 7 U1 0 U2 0 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 0556-2813 J9 PHYS REV C JI Phys. Rev. C PD NOV PY 1991 VL 44 IS 5 BP 2041 EP 2052 DI 10.1103/PhysRevC.44.2041 PG 12 WC Physics, Nuclear SC Physics GA GP735 UT WOS:A1991GP73500036 ER PT J AU OAKLEY, DS PETERSON, RJ SEESTROM, SJ MORRIS, CL PLUM, MA ZUMBRO, JD WILLIAMS, AL BRYAN, MA MCDONALD, JW MOORE, CF AF OAKLEY, DS PETERSON, RJ SEESTROM, SJ MORRIS, CL PLUM, MA ZUMBRO, JD WILLIAMS, AL BRYAN, MA MCDONALD, JW MOORE, CF TI ENERGY-DEPENDENCE OF PION INELASTIC-SCATTERING FROM PB-208 SO PHYSICAL REVIEW C LA English DT Article ID MULTIPOLE MATRIX-ELEMENTS; GIANT QUADRUPOLE-RESONANCE; PROTON-SCATTERING; NEUTRON; NUCLEI; TRANSITIONS; STATES; REGION AB Differential cross sections were measured for pion elastic and inelastic scattering from Pb-208 at T-pi = 120 and 250 MeV. Energy-dependent neutron- and proton-transition matrix elements for a range of excited states were extracted and tested for consistency, using several structure models. C1 UNIV COLORADO,BOULDER,CO 80309. UNIV CALIF LOS ALAMOS SCI LAB,LOS ALAMOS,NM 87545. UNIV PENN,PHILADELPHIA,PA 19104. UNIV TEXAS,AUSTIN,TX 78712. RP OAKLEY, DS (reprint author), LEWIS & CLARK COLL,PORTLAND,OR 97219, USA. NR 31 TC 4 Z9 4 U1 0 U2 1 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 0556-2813 J9 PHYS REV C JI Phys. Rev. C PD NOV PY 1991 VL 44 IS 5 BP 2058 EP 2064 DI 10.1103/PhysRevC.44.2058 PG 7 WC Physics, Nuclear SC Physics GA GP735 UT WOS:A1991GP73500038 ER PT J AU YUAN, VW BOWMAN, CD BOWMAN, JD BUSH, JE DELHEIJ, PPJ FRANKLE, CM GOULD, CR HAASE, DG KNUDSON, JN MITCHELL, GE PENTTILA, S POSTMA, H ROBERSON, NR SEESTROM, SJ SZYMANSKI, JJ ZHU, X AF YUAN, VW BOWMAN, CD BOWMAN, JD BUSH, JE DELHEIJ, PPJ FRANKLE, CM GOULD, CR HAASE, DG KNUDSON, JN MITCHELL, GE PENTTILA, S POSTMA, H ROBERSON, NR SEESTROM, SJ SZYMANSKI, JJ ZHU, X TI PARITY NONCONSERVATION IN POLARIZED-NEUTRON TRANSMISSION THROUGH LA-139 SO PHYSICAL REVIEW C LA English DT Article ID RESONANCES; VIOLATION AB Parity nonconservation has been studied in the transmission of longitudinally polarized epithermal neutrons incident upon a La-139 target. Previous experiments have demonstrated the existence of a large value of the longitudinal asymmetry in the 0.734-eV p-wave resonance of the compound nucleus La-140, but report conflicting values for the measured asymmetry. We report the results of an experiment at the Los Alamos Neutron Scattering Center (LANSCE) which measured the asymmetry by two independent methods. One of these methods utilizes a conventional polarizer and a single lanthanum target. The other method uses an unpolarized beam with two lanthanum targets, and therefore does not require a separate measurement of the beam polarization. The asymmetry values determined from these two methods (0.1015 +/- 0.0045 and 0.0955 +/- 0.0035, respectively) are compared to previously measured values. Measurement of the asymmetry of the 0.734-eV resonance in La-139 provides a highly accurate method of determining the polarization of an epithermal neutron beam. C1 N CAROLINA STATE UNIV,RALEIGH,NC 27695. TRIANGLE UNIV NUCL LAB,DURHAM,NC 27706. TRIUMF,VANCOUVER V6T 2A3,BC,CANADA. DELFT UNIV TECHNOL,DELFT,NETHERLANDS. DUKE UNIV,DURHAM,NC 27706. RP YUAN, VW (reprint author), UNIV CALIF LOS ALAMOS SCI LAB,LOS ALAMOS,NM 87544, USA. RI Gould, Christopher/M-7676-2013; OI Bush, Judith/0000-0001-6240-4121 NR 17 TC 58 Z9 58 U1 0 U2 4 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 0556-2813 J9 PHYS REV C JI Phys. Rev. C PD NOV PY 1991 VL 44 IS 5 BP 2187 EP 2194 DI 10.1103/PhysRevC.44.2187 PG 8 WC Physics, Nuclear SC Physics GA GP735 UT WOS:A1991GP73500048 ER PT J AU MOORE, CF JOHNSON, K KAHRIMANIS, GP MCDONALD, J SNELL, M WARD, HJ YOO, SH MORRIS, CL MORDECHAI, S BURLEIN, M CLAYTOR, N FORTUNE, HT IVIE, R LIU, GB ODONNELL, JM SMITH, D AUERBACH, N ROBSON, D AF MOORE, CF JOHNSON, K KAHRIMANIS, GP MCDONALD, J SNELL, M WARD, HJ YOO, SH MORRIS, CL MORDECHAI, S BURLEIN, M CLAYTOR, N FORTUNE, HT IVIE, R LIU, GB ODONNELL, JM SMITH, D AUERBACH, N ROBSON, D TI ANGULAR-DISTRIBUTIONS FOR THE DOUBLE ISOBARIC ANALOG AND A T-LESS-THAN STATE AT HIGH-EXCITATION IN PION DOUBLE CHARGE-EXCHANGE ON NB-93 SO PHYSICAL REVIEW C LA English DT Note ID INELASTIC-SCATTERING; C-12 AB The double isobaric analog state \IASXIAS> and a new resonance below the \IASXIAS> have been observed in pion-induced double-charge-exchange reactions on Nb-93. Angular distributions have been measured for both transitions. The cross section observed for the T < resonance is 21% of that for the \IASXIAS> in Tc-93. We mention various possibilities for the nature of the observed resonance but have no unique explanation for its large cross section. C1 UNIV CALIF LOS ALAMOS SCI LAB,LOS ALAMOS,NM 87545. BEN GURION UNIV NEGEV,IL-84105 BEER SHEVA,ISRAEL. UNIV PENN,PHILADELPHIA,PA 19104. TEL AVIV UNIV,IL-69978 TEL AVIV,ISRAEL. FLORIDA STATE UNIV,TALLAHASSEE,FL 32306. RP MOORE, CF (reprint author), UNIV TEXAS,AUSTIN,TX 78712, USA. NR 24 TC 8 Z9 8 U1 0 U2 0 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 0556-2813 J9 PHYS REV C JI Phys. Rev. C PD NOV PY 1991 VL 44 IS 5 BP 2209 EP 2212 DI 10.1103/PhysRevC.44.2209 PG 4 WC Physics, Nuclear SC Physics GA GP735 UT WOS:A1991GP73500050 ER PT J AU CHADWICK, MB OBLOZINSKY, P AF CHADWICK, MB OBLOZINSKY, P TI LINEAR MOMENTUM IN THE EXCITON MODEL - A CONSISTENT WAY TO OBTAIN ANGULAR-DISTRIBUTIONS SO PHYSICAL REVIEW C LA English DT Note ID NEUTRON EMISSION; PREEQUILIBRIUM; SCATTERING; CONTINUUM; COMPOUND; SPECTRA; STATE AB We present an exciton model for preequilibrium emission in nucleon-induced reactions in which linear-momentum conservation is included. The particle emission contributions from the first two preequilibrium stages are calculated by determining exact particle-hole state densities with a specific energy and linear momentum in a Fermi-gas model of the nucleus. Angular distributions arise naturally from our treatment and do not have to be added in an ad hoc way. The angular distributions that we obtain from the first two preequilibrium stages are identical to those found using the Kikuchi-Kawai quasifree scattering kernel. C1 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 30 TC 39 Z9 39 U1 0 U2 0 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 0556-2813 J9 PHYS REV C JI Phys. Rev. C PD NOV PY 1991 VL 44 IS 5 BP R1740 EP R1744 PG 5 WC Physics, Nuclear SC Physics GA GP735 UT WOS:A1991GP73500005 ER PT J AU JADACH, S RICHTERWAS, E WARD, BFL WAS, Z AF JADACH, S RICHTERWAS, E WARD, BFL WAS, Z TI HIGH-PRECISION IMPROVED-ANALYTIC-EXPONENTIATION RESULTS FOR MULTIPLE-PHOTON EFFECTS IN LOW-ANGLE BHABHA SCATTERING AT THE SLAC LINEAR COLLIDER AND THE CERN E+E- COLLIDER LEP SO PHYSICAL REVIEW D LA English DT Article ID ANNIHILATION; PAIR AB Starting from an earlier benchmark analytical calculation of the luminosity process e+e- --> e+e- +(gamma) at the SLAC Linear Collider (SLC) and the CERN e+e- collider LEP, we use the methods of Yennie, Frautschi, and Suura to develop an analytical improved naive exponentiated formula for this process. The formula is compared to our multiple-photon Monte Carlo event generator BHLUMI (1.13) for the same process. We find agreement on the overall cross-section normalization between the exponentiated formula and BHLUMI below the 0.2% level. In this way, we obtain an important cross-check on the normalization of our higher-order results in BHLUMI and we arrive at formulas which represent the LEP/SLC luminosity process in the below 1% Z0 physics tests of the SU(2)L X U(1) theory in complete analogy with the famous high-precision Z0 line-shape formulas for the e+e- --> mu+mu- process discussed by Berends et al., for example. C1 JAGIELLONIAN UNIV,INST PHYS,PL-31007 KRAKOW,POLAND. JAGIELLONIAN UNIV,INST COMP SCI,PL-31007 KRAKOW,POLAND. UNIV TENNESSEE,DEPT PHYS & ASTRON,KNOXVILLE,TN 37996. STANFORD UNIV,STANFORD LINEAR ACCELERATOR CTR,STANFORD,CA 94305. INST NUCL PHYS,PL-31342 KRAKOW,POLAND. RP JADACH, S (reprint author), EUROPEAN ORG NUCL RES,CERN,DIV THEORY,GENEVA 23,SWITZERLAND. NR 25 TC 10 Z9 10 U1 0 U2 0 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 0556-2821 J9 PHYS REV D JI Phys. Rev. D PD NOV 1 PY 1991 VL 44 IS 9 BP 2669 EP 2677 DI 10.1103/PhysRevD.44.2669 PG 9 WC Astronomy & Astrophysics; Physics, Particles & Fields SC Astronomy & Astrophysics; Physics GA GT642 UT WOS:A1991GT64200007 ER PT J AU BARGER, V CHEUNG, K HAN, T ZEPPENFELD, D AF BARGER, V CHEUNG, K HAN, T ZEPPENFELD, D TI SINGLE-FORWARD-JET TAGGING AND CENTRAL-JET VETOING TO IDENTIFY THE LEPTONIC WW DECAY MODE OF A HEAVY HIGGS BOSON SO PHYSICAL REVIEW D LA English DT Article ID LARGE TRANSVERSE-MOMENTUM; FERMILAB TEVATRON; SYMMETRY-BREAKING; PPBAR COLLISIONS; QUARK PRODUCTION; PAIR PRODUCTION; TOP QUARKS; SCATTERING; COLLIDER; SUPERCOLLIDERS AB We study the extraction of the heavy-Higgs-boson signal H --> W+W- --> lBAR-nu, l-nu-BAR (l = e or mu) from the standard-model background at hadron supercolliders. By tagging a single forward jet with energy E(j) > 3 TeV and pseudorapidity 3 < /eta(j)/ < 5 and by vetoing central jets of transverse momenta pT(j) > 60 GeV in the pseudorapidity range 0 < /eta(j)/ < 3, the QCD WWj and ttjBAR --> WWbbjBAR backgrounds are suppressed. For m(H) = 1 TeV there are about 46 signal events from electroweak-vector-boson scattering (of which 36 events are of Higgs-boson origin) at the Superconducting Super Collider (SSC) for an integrated luminosity of 10 fb-1 and 10 other events from the WWj and ttjBAR backgrounds for m(t) = 140 GeV. The experimental separation of the vector-boson-scattering subprocess is thereby possible. At the CERN Large Hadron Collider, with an E(j) > 2 TeV jet energy cut, all cross sections are about a factor of 10 below the SSC values. C1 FERMI NATL ACCELERATOR LAB,BATAVIA,IL 60510. RP BARGER, V (reprint author), UNIV WISCONSIN,DEPT PHYS,MADISON,WI 53706, USA. RI Cheung, Kingman/A-8380-2008 OI Cheung, Kingman/0000-0003-2176-4053 NR 52 TC 50 Z9 50 U1 0 U2 0 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 0556-2821 J9 PHYS REV D JI Phys. Rev. D PD NOV 1 PY 1991 VL 44 IS 9 BP 2701 EP 2716 DI 10.1103/PhysRevD.44.2701 PG 16 WC Astronomy & Astrophysics; Physics, Particles & Fields SC Astronomy & Astrophysics; Physics GA GT642 UT WOS:A1991GT64200009 ER PT J AU MAXWELL, CJ PARKE, S AF MAXWELL, CJ PARKE, S TI APPROXIMATING THE PRODUCTION OF A VECTOR BOSON PLUS MULTIJETS AT HADRON COLLIDERS SO PHYSICAL REVIEW D LA English DT Article ID JET PRODUCTION; AMPLITUDES; SCATTERING; QCD AB We give approximations to the matrix element squared for the production of a vector boson accompanied by an arbitrary number of jets. Only subprocesses containing one and two quark-antiquark pairs are estimated. Approximate cross sections and kinematical distributions are compared to those obtained from the known exact tree-level matrix elements for W plus four and three jets and Z plus three jets using all subprocesses, and an agreement at the approximately 30% level is found. The approximations are simple and can be rapidly evaluated on a computer, saving an order of magnitude in CPU time compared to using the tree-level exact matrix elements. Estimates of the cross sections for W plus five jets and the Z plus four jets, as well as their kinematical distributions are also given. C1 FERMI NATL ACCELERATOR LAB,BATAVIA,IL 60510. RP MAXWELL, CJ (reprint author), UNIV DURHAM,DEPT PHYS,DURHAM DH1 3HP,ENGLAND. NR 16 TC 5 Z9 5 U1 0 U2 0 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 0556-2821 J9 PHYS REV D JI Phys. Rev. D PD NOV 1 PY 1991 VL 44 IS 9 BP 2727 EP 2736 DI 10.1103/PhysRevD.44.2727 PG 10 WC Astronomy & Astrophysics; Physics, Particles & Fields SC Astronomy & Astrophysics; Physics GA GT642 UT WOS:A1991GT64200011 ER PT J AU COUTURE, G AF COUTURE, G TI POSSIBILITY OF MEASURING THE MAGNETIC-MOMENT OF THE W-BOSON AT HEAVY-ION COLLIDERS SO PHYSICAL REVIEW D LA English DT Article ID GAMMA-VERTEX; SELF-INTERACTIONS; PAIR PRODUCTION; COLLISIONS; CONSTRAINTS; PHYSICS; BEAMS; W+/ AB We consider the possibility of measuring the magnetic moment at the W boson at a heavy-ion collider. We find that the cross section for the process Pb+Pb --> gamma-gamma --> e+/- nu-e-mu -/+ nu-mu is very sensitive to this parameter and that a 3-sigma measurement of 35% seems possible at the CERN Large Hadron Collider and a precision of 8% or so at the Superconducting Super Collider, given an integrated luminosity of 0.1 pb-1. C1 SO METHODIST UNIV, DEPT PHYS, DALLAS, TX 75275 USA. RP BROOKHAVEN NATL LAB, DEPT PHYS, UPTON, NY 11973 USA. NR 52 TC 6 Z9 6 U1 0 U2 0 PU AMER PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 2470-0010 EI 2470-0029 J9 PHYS REV D JI Phys. Rev. D PD NOV 1 PY 1991 VL 44 IS 9 BP 2755 EP 2761 DI 10.1103/PhysRevD.44.2755 PG 7 WC Astronomy & Astrophysics; Physics, Particles & Fields SC Astronomy & Astrophysics; Physics GA GT642 UT WOS:A1991GT64200014 ER PT J AU KOGUT, JB SINCLAIR, DK TEPER, M AF KOGUT, JB SINCLAIR, DK TEPER, M TI GLUEBALLS, MESONS, AND THE STRING TENSION - AN EXPLORATORY-STUDY OF LATTICE QCD WITH 2 COLORS AND 4 LIGHT FLAVORS SO PHYSICAL REVIEW D LA English DT Article ID SU(2) GAUGE-THEORY; SMALL-VOLUME; SPECTRUM; SU(3); EXPANSION; FERMIONS; TORUS AB We calculate various meson and glueball masses in the version of lattice QCD with two colors and four (light) flavors. We do so both in the chirally symmetric and in the spontaneously broken phases. In the spontaneously broken phase (performed on 10(3)20 lattices at beta = 1.975) we find the following mass ratios: m(G)(0+)/m(rho) = 1.1(2), m(G)(0+)/square-root-kappa = 2.8(5), square-root-kappa/m(rho) = 0.39(3), m(G)(2+)/m(G)(0+) = 1.7(5). In the small-spatial-volume, chirally symmetric phase we explicitly observe parity doubling among the mesons but not among the glueballs. All these calculations are exploratory for a variety of reasons which we discuss. C1 ARGONNE NATL LAB,DIV PHYS,ARGONNE,IL 60439. UNIV OXFORD,ALL SOULS COLL,OXFORD OX1 3NP,ENGLAND. UNIV OXFORD,DEPT THEORET PHYS,OXFORD OX1 3NP,ENGLAND. RP KOGUT, JB (reprint author), UNIV ILLINOIS,DEPT PHYS,1110 W GREEN ST,URBANA,IL 61801, USA. NR 26 TC 8 Z9 8 U1 0 U2 0 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 0556-2821 J9 PHYS REV D JI Phys. Rev. D PD NOV 1 PY 1991 VL 44 IS 9 BP 2869 EP 2878 DI 10.1103/PhysRevD.44.2869 PG 10 WC Astronomy & Astrophysics; Physics, Particles & Fields SC Astronomy & Astrophysics; Physics GA GT642 UT WOS:A1991GT64200027 ER PT J AU BRAATEN, E THOMA, MH AF BRAATEN, E THOMA, MH TI ENERGY-LOSS OF A HEAVY QUARK IN THE QUARK-GLUON PLASMA SO PHYSICAL REVIEW D LA English DT Note ID HOT GAUGE-THEORIES; QCD; AMPLITUDES AB The energy loss dE/dx for a heavy quark propagating through a quark-gluon plasma is calculated to leading order in the QCD coupling constant. Simple formulas for dE/dx are obtained in the regions E << M(Q)2/T and E >> M(Q)2/T, where M(Q) is the mass of the heavy quark and T is the temperature. The crossover energy between the two regions is determined to be approximately 1.8M(Q)2/T. Under conditions relevant to ultrarelativistic heavy-ion collisions, charm quarks and bottom quarks lie on opposite sides of the crossover energy and therefore experience significantly different energy losses. C1 UNIV CALIF BERKELEY,LAWRENCE BERKELEY LAB,DIV NUCL SCI,BERKELEY,CA 94720. RP BRAATEN, E (reprint author), NORTHWESTERN UNIV,DEPT PHYS & ASTRON,EVANSTON,IL 60208, USA. NR 18 TC 202 Z9 202 U1 0 U2 0 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 0556-2821 J9 PHYS REV D JI Phys. Rev. D PD NOV 1 PY 1991 VL 44 IS 9 BP R2625 EP R2630 DI 10.1103/PhysRevD.44.R2625 PG 6 WC Astronomy & Astrophysics; Physics, Particles & Fields SC Astronomy & Astrophysics; Physics GA GT642 UT WOS:A1991GT64200001 ER PT J AU MIKAELIAN, KO AF MIKAELIAN, KO TI KINETIC-ENERGY OF RAYLEIGH-TAYLOR AND RICHTMYER-MESHKOV INSTABILITIES SO PHYSICS OF FLUIDS A-FLUID DYNAMICS LA English DT Article ID STRATIFIED FLUIDS; GROWTH-RATES; SN-1987A; MODEL; INTERFACES AB General expressions for the kinetic energy associated with Rayleigh-Taylor (RT) and Richtmyer-Meshkov (RM) instabilities in incompressible fluids are derived. The results are valid for small perturbations in continuous as well as discontinuous density profiles. It was found that KE(RT)/KE(RM) = ge2-gamma-tau/(DELTA-upsilon-GAMMA)2 = (ge-gamma-tau/DELTA-upsilon-gamma)2, where tau = time, g = acceleration, DELTA-upsilon = velocity jump, and gamma is the exponential growth rate of the RT amplitude. The linear growth rate of the RM amplitude is DELTA-upsilon-GAMMA-2 = DELTA-upsilon-gamma-2/g, and is found by solving an eigenvalue equation for a given density profile subject to appropriate boundary conditions. In general, KE(RT) asymptotes to a constant value at large k (k = 2-pi/lambda, lambda = wavelength), while KE(RM) continues to grow with k. Several analytic examples are illustrated and the k dependence of the kinetic energies is displayed. RP MIKAELIAN, KO (reprint author), UNIV CALIF LAWRENCE LIVERMORE NATL LAB,LIVERMORE,CA 94550, USA. NR 35 TC 5 Z9 5 U1 1 U2 7 PU AMER INST PHYSICS PI WOODBURY PA CIRCULATION FULFILLMENT DIV, 500 SUNNYSIDE BLVD, WOODBURY, NY 11797-2999 SN 0899-8213 J9 PHYS FLUIDS A-FLUID PD NOV PY 1991 VL 3 IS 11 BP 2625 EP 2637 DI 10.1063/1.858151 PG 13 WC Mechanics; Physics, Fluids & Plasmas SC Mechanics; Physics GA GL829 UT WOS:A1991GL82900014 ER PT J AU MIKAELIAN, KO AF MIKAELIAN, KO TI DENSITY GRADIENT STABILIZATION OF THE RICHTMYER-MESHKOV INSTABILITY SO PHYSICS OF FLUIDS A-FLUID DYNAMICS LA English DT Article ID RAYLEIGH-TAYLOR INSTABILITY; STRATIFIED FLUIDS AB Numerical and analytical results on the growth rate of the Richtmyer-Meshkov (RM) instability in continuous density profiles are presented, and this paper relates them to the Rayleigh-Taylor (RT) instability by treating the shock as an instantaneous acceleration of incompressible fluids. Most of this work is in the linear regime, where it is found that density gradient stabilization is even more effective for the RM instability than for the RT instability. Recent experimental results are discussed and a numerical simulation of a shock-tube experiment with a continuous density profile between two gases is presented. RP MIKAELIAN, KO (reprint author), UNIV CALIF LAWRENCE LIVERMORE NATL LAB,LIVERMORE,CA 94550, USA. NR 23 TC 12 Z9 12 U1 0 U2 16 PU AMER INST PHYSICS PI WOODBURY PA CIRCULATION FULFILLMENT DIV, 500 SUNNYSIDE BLVD, WOODBURY, NY 11797-2999 SN 0899-8213 J9 PHYS FLUIDS A-FLUID PD NOV PY 1991 VL 3 IS 11 BP 2638 EP 2643 DI 10.1063/1.858152 PG 6 WC Mechanics; Physics, Fluids & Plasmas SC Mechanics; Physics GA GL829 UT WOS:A1991GL82900015 ER PT J AU VIECELLI, JA AF VIECELLI, JA TI LAGRANGIAN TURBULENCE AND THE BROWNIAN-MOTION PARADOX SO PHYSICS OF FLUIDS A-FLUID DYNAMICS LA English DT Article ID DYNAMICS AB The unique properties of three-dimensional hydrodynamic turbulence depend on the nature of the long-range time correlations as well as the spatial correlations. Although Kolmogorov's second similarity hypothesis predicts a power-law spatial scaling exponent for the Eulerian velocity fluctuations in agreement with experiments, it also leads, via the Lagrangian velocity time structure function relationship, to particle dispersion predictions that are inconsistent with enhanced diffusion. Recently, a new computational technique has been developed which can generate random power-law correlated fields in any number of dimensions with unlimited scale range. This new method is used to explore the consequences of a proposed set of assumptions about the nature of the time correlations and their relationship to the spatial correlations. In particular, the Brownian motion paradox is examined and it is shown that it can be resolved if the time domain constraint part of Kolmogorov's second hypothesis is relaxed and replaced with an assumption of space-time isotropy. The proposed modification preserves the observed one-dimensional k-5/3 spatial energy spectrum, allows for enhanced diffusion consistent with Richardson's law, is consistent with Taylor's frozen turbulence assumption under the appropriate conditions, and yields an omega-5/3 frequency spectrum for the velocity fluctuations in a frame at rest with respect to the turbulence. RP VIECELLI, JA (reprint author), UNIV CALIF LAWRENCE LIVERMORE NATL LAB,LIVERMORE,CA 94550, USA. NR 18 TC 3 Z9 3 U1 0 U2 0 PU AMER INST PHYSICS PI WOODBURY PA CIRCULATION FULFILLMENT DIV, 500 SUNNYSIDE BLVD, WOODBURY, NY 11797-2999 SN 0899-8213 J9 PHYS FLUIDS A-FLUID PD NOV PY 1991 VL 3 IS 11 BP 2698 EP 2708 DI 10.1063/1.858217 PG 11 WC Mechanics; Physics, Fluids & Plasmas SC Mechanics; Physics GA GL829 UT WOS:A1991GL82900023 ER PT J AU DRAKE, RP BATHA, SH AF DRAKE, RP BATHA, SH TI THE INFLUENCE OF SUBSIDIARY LANGMUIR DECAY ON THE SPECTRUM OF STIMULATED RAMAN-SCATTERING SO PHYSICS OF FLUIDS B-PLASMA PHYSICS LA English DT Letter ID LASER-PRODUCED PLASMAS; BRILLOUIN-SCATTERING; UNDERDENSE PLASMA; COMPETITION; TARGETS; WAVES; INSTABILITIES AB The saturation of stimulated Raman scattering (SRS) from plasmas produced by visible or ultraviolet (UV) lasers is discussed. A correspondence is reported between relatively strong plasma-wave damping and relatively large spectral intensity in the observed SRS spectra. This observation is interpreted by the hypothesis that SRS saturates at roughly the level of marginal stability for Langmuir decay. C1 UNIV CALIF DAVIS,LIVERMORE,CA 94550. RP DRAKE, RP (reprint author), UNIV CALIF LAWRENCE LIVERMORE NATL LAB,PLASMA PHYS RES INST,LIVERMORE,CA 94550, USA. RI Drake, R Paul/I-9218-2012 OI Drake, R Paul/0000-0002-5450-9844 NR 27 TC 57 Z9 57 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 NOV PY 1991 VL 3 IS 11 BP 2936 EP 2938 DI 10.1063/1.859926 PG 3 WC Physics, Fluids & Plasmas SC Physics GA GL828 UT WOS:A1991GL82800002 ER PT J AU PRASAD, MK KERSHAW, DS AF PRASAD, MK KERSHAW, DS TI STABLE-SOLUTIONS OF NONLOCAL ELECTRON HEAT-TRANSPORT EQUATIONS SO PHYSICS OF FLUIDS B-PLASMA PHYSICS LA English DT Article ID STEEP TEMPERATURE-GRADIENTS; LASER-PRODUCED PLASMAS; FUSION AB Electron heat transport equations with a nonlocal heat flux are in general ill-posed and intrinsically unstable, as proved by the present authors [Phys. Fluids B 1, 2430 (1989)]. A straightforward numerical solution of these equations will therefore lead to absurd results. It is shown here that by imposing a minimal set of constraints on the problem it is possible to arrive at a globally stable, consistent, and energy conserving numerical solution. RP PRASAD, MK (reprint author), UNIV CALIF LAWRENCE LIVERMORE NATL LAB,DIV COMPUTAT PHYS,LIVERMORE,CA 94550, USA. NR 13 TC 12 Z9 12 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 NOV PY 1991 VL 3 IS 11 BP 3087 EP 3091 DI 10.1063/1.859995 PG 5 WC Physics, Fluids & Plasmas SC Physics GA GL828 UT WOS:A1991GL82800020 ER PT J AU MAYO, RM WYSOCKI, FJ FERNANDEZ, JC AF MAYO, RM WYSOCKI, FJ FERNANDEZ, JC TI A MODEL FOR DETERMINING RELAXATION ELECTRIC-FIELDS IN SPHEROMAKS SO PHYSICS OF FLUIDS B-PLASMA PHYSICS LA English DT Article ID MESH FLUX CONSERVERS; ENERGY CONFINEMENT AB Past spheromak experiments have experienced poor confinement [Nucl. Fusion 28, 1555 (1988); Phys. Fluids B 2, 115 (1990)] as a result of edge-dominated helicity dissipation due to substantial field error and edge neutral inventory. Recent works have identified the importance of edge helicity loss and its effects on confinement [Phys. Fluids B 2, 115 (1990)]. Herein, the results of the edge helicity dissipation model [Phys. Fluids 30, 1177 (1987)] are applied to determine the relative magnitudes of electric fields during relaxation in spheromaks. This is achieved by quantifying the average electric field in the plasma edge region generated by (a) flux decay and (b) relaxation mechanism(s). It is shown that relaxation electric fields can be as much as three times the flux decay field in the edge. The model also correctly predicts no relaxation electric field when the spheromak is a cold, purely resistively decaying object. In addition, the model provides an estimate for the quantity of magnetic decay power from relaxation, which can be as much as 75% of the total decay power. C1 UNIV CALIF LOS ALAMOS SCI LAB,LOS ALAMOS,NM 87545. RP MAYO, RM (reprint author), N CAROLINA STATE UNIV,DEPT NUCL ENGN,RALEIGH,NC 27695, USA. RI Fernandez, Juan/H-3268-2011 OI Fernandez, Juan/0000-0002-1438-1815 NR 13 TC 3 Z9 3 U1 0 U2 1 PU AMER INST PHYSICS PI WOODBURY PA CIRCULATION FULFILLMENT DIV, 500 SUNNYSIDE BLVD, WOODBURY, NY 11797-2999 SN 0899-8221 J9 PHYS FLUIDS B-PLASMA PD NOV PY 1991 VL 3 IS 11 BP 3160 EP 3166 DI 10.1063/1.859795 PG 7 WC Physics, Fluids & Plasmas SC Physics GA GL828 UT WOS:A1991GL82800027 ER PT J AU HEIDBRINK, WW BARNES, CW HAMMETT, GW KUSAMA, Y SCOTT, SD ZARNSTORFF, MC JOHNSON, LC MCCUNE, D MEDLEY, SS PARK, HK ROQUEMORE, AL STRACHAN, JD TAYLOR, G AF HEIDBRINK, WW BARNES, CW HAMMETT, GW KUSAMA, Y SCOTT, SD ZARNSTORFF, MC JOHNSON, LC MCCUNE, D MEDLEY, SS PARK, HK ROQUEMORE, AL STRACHAN, JD TAYLOR, G TI THE DIFFUSION OF FAST IONS IN OHMIC TFTR DISCHARGES SO PHYSICS OF FLUIDS B-PLASMA PHYSICS LA English DT Article ID NEUTRAL-BEAM INJECTION; ABEL-INVERSION METHOD; DIII-D; TOKAMAK; CALIBRATION; SYSTEMS; PLASMAS; RIPPLE; PLT AB Short duration (20 msec) neutral deuterium beams are injected into the TFTR tokamak [Plasma Physics and Controlled Nuclear Fusion Research 1986 (IAEA, Vienna, 1987), Vol. I, p. 51]. The subsequent confinement, thermalization, and diffusion of the beam ions are studied with multichannel neutron and charge exchange diagnostics. The central fast-ion diffusion (< 0.05 m2/sec) is an order of magnitude smaller than typical thermal transport coefficients. C1 UNIV CALIF IRVINE,DEPT PHYS,IRVINE,CA 92717. UNIV CALIF LOS ALAMOS SCI LAB,LOS ALAMOS,NM 87545. RP HEIDBRINK, WW (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 28 TC 35 Z9 35 U1 1 U2 8 PU AMER INST PHYSICS PI WOODBURY PA CIRCULATION FULFILLMENT DIV, 500 SUNNYSIDE BLVD, WOODBURY, NY 11797-2999 SN 0899-8221 J9 PHYS FLUIDS B-PLASMA PD NOV PY 1991 VL 3 IS 11 BP 3167 EP 3170 DI 10.1063/1.859796 PG 4 WC Physics, Fluids & Plasmas SC Physics GA GL828 UT WOS:A1991GL82800028 ER PT J AU JAKOBSON, M ROSEN, L AF JAKOBSON, M ROSEN, L TI MANLEY,JOHN,HENRY - OBITUARY SO PHYSICS TODAY LA English DT Item About an Individual C1 UNIV CALIF LOS ALAMOS SCI LAB,LOS ALAMOS,NM 87544. RP JAKOBSON, M (reprint author), UNIV MONTANA,MISSOULA,MT 59812, USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU AMER INST PHYSICS PI WOODBURY PA CIRCULATION FULFILLMENT DIV, 500 SUNNYSIDE BLVD, WOODBURY, NY 11797-2999 SN 0031-9228 J9 PHYS TODAY JI Phys. Today PD NOV PY 1991 VL 44 IS 11 BP 113 EP 114 DI 10.1063/1.2810336 PG 2 WC Physics, Multidisciplinary SC Physics GA GP915 UT WOS:A1991GP91500016 ER PT J AU DREICER, H JAHODA, F SHLACHTER, J AF DREICER, H JAHODA, F SHLACHTER, J TI HAMMEL,JAY,E. - OBITUARY SO PHYSICS TODAY LA English DT Item About an Individual RP DREICER, H (reprint author), UNIV CALIF LOS ALAMOS SCI LAB,LOS ALAMOS,NM 87544, USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU AMER INST PHYSICS PI WOODBURY PA CIRCULATION FULFILLMENT DIV, 500 SUNNYSIDE BLVD, WOODBURY, NY 11797-2999 SN 0031-9228 J9 PHYS TODAY JI Phys. Today PD NOV PY 1991 VL 44 IS 11 BP 114 EP 115 DI 10.1063/1.2810338 PG 2 WC Physics, Multidisciplinary SC Physics GA GP915 UT WOS:A1991GP91500018 ER PT J AU HWANG, I KOHCHI, T HAUGE, BM GOODMAN, HM SCHMIDT, R CNOPS, G DEAN, C GIBSON, S IBA, K LEMIEUX, B ARONDEL, V DANHOFF, L SOMERVILLE, C AF HWANG, I KOHCHI, T HAUGE, BM GOODMAN, HM SCHMIDT, R CNOPS, G DEAN, C GIBSON, S IBA, K LEMIEUX, B ARONDEL, V DANHOFF, L SOMERVILLE, C TI IDENTIFICATION AND MAP POSITION OF YAC CLONES COMPRISING ONE-THIRD OF THE ARABIDOPSIS GENOME SO PLANT JOURNAL LA English DT Article ID POLYMORPHISM LINKAGE MAP; THALIANA; YEAST; DNA AB YAC clones corresponding to 125 Arabidopsis thaliana RFLP markers have been identified. At least one YAC clone has been isolated for each of the RFLP markers tested. Based on CHEF gel analysis of 196 clones, the mean insert size of the available Arabidopsis YAC libraries is approximately 160 kb. The YACs of known genetic map location encompass about 30% of the Arabidopsis genome. The results presented here represent a first step towards assembly of an overlapping YAC library of the A. thaliana genome. C1 HARVARD UNIV,SCH MED,DEPT GENET,BOSTON,MA 02115. MASSACHUSETTS GEN HOSP,DEPT MOLEC BIOL,BOSTON,MA 02114. JOHN INNES CTR,AFRC,INST PLANT SCI RES,CAMBRIDGE LAB,NORWICH NR4 7UJ,ENGLAND. MICHIGAN STATE UNIV,US DOE,PLANT RES LAB,E LANSING,MI 48824. RI Somerville, Christopher/A-4048-2009 OI Somerville, Christopher/0000-0003-4647-0094 NR 11 TC 56 Z9 56 U1 0 U2 1 PU BLACKWELL SCIENCE LTD PI OXFORD PA OSNEY MEAD, OXFORD, OXON, ENGLAND OX2 0EL SN 0960-7412 J9 PLANT J JI Plant J. PD NOV PY 1991 VL 1 IS 3 BP 367 EP 374 DI 10.1046/j.1365-313X.1991.t01-5-00999.x PG 8 WC Plant Sciences SC Plant Sciences GA GW290 UT WOS:A1991GW29000011 PM 1844889 ER PT J AU SMART, LB MCINTOSH, L AF SMART, LB MCINTOSH, L TI EXPRESSION OF PHOTOSYNTHESIS GENES IN THE CYANOBACTERIUM SYNECHOCYSTIS SP PCC-6803 - PSAA-PSAB AND PSBA TRANSCRIPTS ACCUMULATE IN DARK-GROWN CELLS SO PLANT MOLECULAR BIOLOGY LA English DT Article DE GENE EXPRESSION; HETEROTROPHIC GROWTH; LEUCINE ZIPPER; PHOTOSYSTEM-I; PHOTOSYSTEM-II ID I REACTION-CENTER; CHLOROPHYLL-A-APOPROTEINS; ENCODING SUBUNIT-II; 2 P700 CHLOROPHYLL; PHOTOSYSTEM-I; NUCLEOTIDE-SEQUENCE; MOLECULAR-CLONING; CHLOROPLAST GENOME; ANACYSTIS-NIDULANS; RNA GENES AB We have cloned and sequenced the psaA and psaB genes from the unicellular cyanobacterium Synechocystis sp. PCC 6803. These genes are arranged in tandem, are co-transcribed, and are highly homologous to the psaA and psab genes previously characterized. RNA was isolated from light-grown cells, from cells put in total darkness with and without glucose, and from cells grown under light-activated heterotrophic growth (LAHG) conditions. Quantitation of hybridization to northern blots revealed only a slight decrease in the accumulation of the psaA-psaB transcript in cells grown in complete darkness with glucose and in LAHG cells, relative to light-grown cells. Accumulation of the psbA transcript steadily declines through dark incubation, with a steady-state level in LAHG cells 28% of that in light-grown cells. Transcripts from psbD, psaD, and rbcLS accumulate in cells grown in complete darkness and in LAHG cells to approximately the same levels as in light-grown cells. Photosynthesis gene transcripts in cells grown in the dark without glucose were detected, but were highly degraded. Our data prove that transcripts from photosynthesis genes do accumulate in dark-grown Synechocystis 6803, which may allow for synthesis and assembly of photosystem (PS) I and PS II in the dark. C1 MICHIGAN STATE UNIV,US DOE,PLANT RES LAB,E LANSING,MI 48824. MICHIGAN STATE UNIV,DEPT BIOCHEM,E LANSING,MI 48824. MICHIGAN STATE UNIV,US DOE,GENET PROGRAM,E LANSING,MI 48824. OI Smart, Lawrence/0000-0002-7812-7736 NR 50 TC 50 Z9 52 U1 0 U2 2 PU KLUWER ACADEMIC PUBL PI DORDRECHT PA SPUIBOULEVARD 50, PO BOX 17, 3300 AA DORDRECHT, NETHERLANDS SN 0167-4412 J9 PLANT MOL BIOL JI Plant Mol.Biol. PD NOV PY 1991 VL 17 IS 5 BP 959 EP 971 DI 10.1007/BF00037136 PG 13 WC Biochemistry & Molecular Biology; Plant Sciences SC Biochemistry & Molecular Biology; Plant Sciences GA GM462 UT WOS:A1991GM46200001 PM 1932686 ER PT J AU KEILHACKER, M ADAMS, JM ALTMANN, H ANDERSEN, A ANDREW, P ANGELONE, M ARSHAD, SA BAILEY, W BALLANTYNE, P BALET, B BARABASCHI, P BARNSLEY, R BARONIAN, M BARTLETT, DV BELL, AC BENFATTO, I BENALI, G BERGSAKER, H BERTOLDI, P BERTOLINI, E BHATNAGAR, V BICKLEY, AJ BINDSLEV, H BONICELLI, T BOOTH, SJ BOSIA, G BOTMAN, M BOUCHER, D BOUCQUEY, P BREGER, P BRELEN, H BRINKSCHULTE, H BROWN, T BRUSATI, M BUDD, T BURES, M BUSINARO, T BUTCHER, P BUTTGEREIT, H CALDWELLNICHOLS, C CAMPBELL, DJ CARD, P CELENTANO, G CHALLIS, CD CHANKIN, AV CHIRON, D CHRISTIANSEN, J CHRISTODOULOPOULOS, C CHUILON, P CLAESEN, R CLEMENT, S CLIPSHAM, E COAD, JP COMISKEY, M CONROY, S COOKE, M COOPER, S CORDEY, JG CORE, W CORRIGAN, G CORTI, S COSTLEY, AE COTTRELL, G COX, M CRIPWELL, P DEBLANK, H DEESCH, H DEKOCK, L DEKSNIS, E DENNEHINNOV, GB DESCHAMPS, G DIETZ, KJ DMITRENKO, SL DOBBING, J DOLGETTA, N DORLING, SE DOYLE, PG DUCHS, DF DUQUENOY, H EDWARDS, A EHRENBERG, J EKEDAHL, A ELEVANT, T ERENTS, SK ERIKSSON, LG FAJEMIROKUN, H FALTER, H FLORY, D FREILING, J FROGER, C FROISSARD, P FULLARD, K GADEBERG, M GALETSAS, A GAMBIER, D GARRIBBA, M GAZE, P GIANNELLA, R GIBSON, A GILL, RD GIRARD, A GONDHALEKAR, A GORMEZANO, C GOTTARDI, NA GOWERS, C GREEN, BJ HAANGE, R HAAS, G HAIGH, A HAMMETT, G HANCOCK, CJ HARBOUR, PJ HAWKES, NC HAYNES, P HEMMERICH, JL HENDER, T HERZOG, FB HERZOG, RF HOEKZEMA, J HOW, J HUART, M HUGHES, I HUGHES, TP HUGON, M HUGUET, M HWANG, A INGRAM, B IRVING, M JACQUINOT, J JAECKEL, H JAEGER, JF JANESCHITZ, G JANKOWICZ, S JARVIS, ON JENSEN, F JONES, EM JONES, LPDF JONES, TTC JUNGER, JF JUNIQUE, E KAYE, A KEEN, BE KELLY, GJ KERNER, W KONIG, R KONSTANTELLOS, A KOVANEN, M KRAMER, G KUPSCHUS, P LASSER, R LAST, JR LAUNDY, B LAUROTARONI, L LAWSON, K LENNHOLM, M LOARTE, A LOBEL, R LOMAS, P LOUGHLIN, M LOWRY, C MACKLIN, B MADDISON, G MAGYAR, G MANDL, W MARCHESE, V MARCUS, F MART, J MARTIN, E MARTINSOLIS, R MASSMANN, P MCCRACKEN, G MERIGUET, P MIELE, P MILLS, SF MILLWARD, P MOHANTI, R MONDINO, PL MONTVAI, A MORIYAMA, S MORGAN, P MORSI, H MURPHY, G MYNARENDS, M MYRNAS, R NARDONE, C NAVE, F NEWBERT, G NEWMAN, M NIELSEN, P NOLL, P OBERT, W OBRIEN, D OROURKE, J OSTROM, R OTTAVIANI, M PAIN, M PAOLETTI, F PAPASTERGIOU, S PASINI, D PEACOCK, A PEACOCK, N PEARSON, D DESILVA, RP PERINIC, G PERRY, C PICK, M PITTS, R PLANCOULAINE, J POFFE, JP PORCELLI, F PORTE, L PRENTICE, R PUPPIN, S PUTVINSKO, S RADFORD, G RAIMONDI, T DEANDRADE, MCR REBUT, PH REICHLE, R RIGHI, E RIMINI, F ROBINSON, D ROLFE, A ROSS, RT ROSSI, L RUSS, R RUTTER, P SACK, HC SADLER, G SAIBENE, G SALANAVE, JL SANAZZARO, G SANTAGIUSTINA, A SARTORI, R SBORCHIA, C SCHILD, P SCHMID, M SCHMIDT, G SCHUNKE, B SCOTT, SM SIBLEY, A SIMONINI, R SIPS, ACC SMEULDERS, P STANKIEWICZ, R STAMP, M STANGEBY, P START, DF STEED, CA STORK, D STOTT, PE STRINGER, TE STUBBERFIELD, P SUMMERS, D SUMMERS, H SVENSSON, L TAGLE, JA TANGA, A TARONI, A TESINI, A THOMAS, PR THOMPSON, E THOMSEN, K TODD, JM TREVALION, P TUBBING, B TIBONE, F USSELMANN, E VANDERBEKEN, H VLASES, G VONHELLERMANN, M WADE, T WALKER, C WALTON, R WARD, D WATKINS, ML WATSON, MJ WEBER, S WESSON, J WIJNANDS, TJ WILKS, J WILSON, D WINKEL, T WOLF, R WOLLE, B WONG, D WOODWARD, C WU, Y WYKES, M YOUNG, ID ZANNELLI, L ZHU, Y ZWINGMANN, W AF KEILHACKER, M ADAMS, JM ALTMANN, H ANDERSEN, A ANDREW, P ANGELONE, M ARSHAD, SA BAILEY, W BALLANTYNE, P BALET, B BARABASCHI, P BARNSLEY, R BARONIAN, M BARTLETT, DV BELL, AC BENFATTO, I BENALI, G BERGSAKER, H BERTOLDI, P BERTOLINI, E BHATNAGAR, V BICKLEY, AJ BINDSLEV, H BONICELLI, T BOOTH, SJ BOSIA, G BOTMAN, M BOUCHER, D BOUCQUEY, P BREGER, P BRELEN, H BRINKSCHULTE, H BROWN, T BRUSATI, M BUDD, T BURES, M BUSINARO, T BUTCHER, P BUTTGEREIT, H CALDWELLNICHOLS, C CAMPBELL, DJ CARD, P CELENTANO, G CHALLIS, CD CHANKIN, AV CHIRON, D CHRISTIANSEN, J CHRISTODOULOPOULOS, C CHUILON, P CLAESEN, R CLEMENT, S CLIPSHAM, E COAD, JP COMISKEY, M CONROY, S COOKE, M COOPER, S CORDEY, JG CORE, W CORRIGAN, G CORTI, S COSTLEY, AE COTTRELL, G COX, M CRIPWELL, P DEBLANK, H DEESCH, H DEKOCK, L DEKSNIS, E DENNEHINNOV, GB DESCHAMPS, G DIETZ, KJ DMITRENKO, SL DOBBING, J DOLGETTA, N DORLING, SE DOYLE, PG DUCHS, DF DUQUENOY, H EDWARDS, A EHRENBERG, J EKEDAHL, A ELEVANT, T ERENTS, SK ERIKSSON, LG FAJEMIROKUN, H FALTER, H FLORY, D FREILING, J FROGER, C FROISSARD, P FULLARD, K GADEBERG, M GALETSAS, A GAMBIER, D GARRIBBA, M GAZE, P GIANNELLA, R GIBSON, A GILL, RD GIRARD, A GONDHALEKAR, A GORMEZANO, C GOTTARDI, NA GOWERS, C GREEN, BJ HAANGE, R HAAS, G HAIGH, A HAMMETT, G HANCOCK, CJ HARBOUR, PJ HAWKES, NC HAYNES, P HEMMERICH, JL HENDER, T HERZOG, FB HERZOG, RF HOEKZEMA, J HOW, J HUART, M HUGHES, I HUGHES, TP HUGON, M HUGUET, M HWANG, A INGRAM, B IRVING, M JACQUINOT, J JAECKEL, H JAEGER, JF JANESCHITZ, G JANKOWICZ, S JARVIS, ON JENSEN, F JONES, EM JONES, LPDF JONES, TTC JUNGER, JF JUNIQUE, E KAYE, A KEEN, BE KELLY, GJ KERNER, W KONIG, R KONSTANTELLOS, A KOVANEN, M KRAMER, G KUPSCHUS, P LASSER, R LAST, JR LAUNDY, B LAUROTARONI, L LAWSON, K LENNHOLM, M LOARTE, A LOBEL, R LOMAS, P LOUGHLIN, M LOWRY, C MACKLIN, B MADDISON, G MAGYAR, G MANDL, W MARCHESE, V MARCUS, F MART, J MARTIN, E MARTINSOLIS, R MASSMANN, P MCCRACKEN, G MERIGUET, P MIELE, P MILLS, SF MILLWARD, P MOHANTI, R MONDINO, PL MONTVAI, A MORIYAMA, S MORGAN, P MORSI, H MURPHY, G MYNARENDS, M MYRNAS, R NARDONE, C NAVE, F NEWBERT, G NEWMAN, M NIELSEN, P NOLL, P OBERT, W OBRIEN, D OROURKE, J OSTROM, R OTTAVIANI, M PAIN, M PAOLETTI, F PAPASTERGIOU, S PASINI, D PEACOCK, A PEACOCK, N PEARSON, D DESILVA, RP PERINIC, G PERRY, C PICK, M PITTS, R PLANCOULAINE, J POFFE, JP PORCELLI, F PORTE, L PRENTICE, R PUPPIN, S PUTVINSKO, S RADFORD, G RAIMONDI, T DEANDRADE, MCR REBUT, PH REICHLE, R RIGHI, E RIMINI, F ROBINSON, D ROLFE, A ROSS, RT ROSSI, L RUSS, R RUTTER, P SACK, HC SADLER, G SAIBENE, G SALANAVE, JL SANAZZARO, G SANTAGIUSTINA, A SARTORI, R SBORCHIA, C SCHILD, P SCHMID, M SCHMIDT, G SCHUNKE, B SCOTT, SM SIBLEY, A SIMONINI, R SIPS, ACC SMEULDERS, P STANKIEWICZ, R STAMP, M STANGEBY, P START, DF STEED, CA STORK, D STOTT, PE STRINGER, TE STUBBERFIELD, P SUMMERS, D SUMMERS, H SVENSSON, L TAGLE, JA TANGA, A TARONI, A TESINI, A THOMAS, PR THOMPSON, E THOMSEN, K TODD, JM TREVALION, P TUBBING, B TIBONE, F USSELMANN, E VANDERBEKEN, H VLASES, G VONHELLERMANN, M WADE, T WALKER, C WALTON, R WARD, D WATKINS, ML WATSON, MJ WEBER, S WESSON, J WIJNANDS, TJ WILKS, J WILSON, D WINKEL, T WOLF, R WOLLE, B WONG, D WOODWARD, C WU, Y WYKES, M YOUNG, ID ZANNELLI, L ZHU, Y ZWINGMANN, W TI JET - PROGRESS IN PERFORMANCE AND UNDERSTANDING SO PLASMA PHYSICS AND CONTROLLED FUSION LA English DT Article; Proceedings Paper CT 18TH EUROPEAN CONF ON CONTROLLED FUSION AND PLASMA PHYSICS CY JUN 03-07, 1991 CL BERLIN, GERMANY SP EUROPEAN PHYS SOC, DIV PLASMA PHYS DE TOKAMAK; JET; FUSION REACTOR; PARTICLE TRANSPORT; ENERGY TRANSPORT; H-MODE PHYSICS; DIVERTOR PHYSICS ID CONFINEMENT; PLASMAS; TEMPERATURE; TRANSPORT; PARTICLE; MODE AB In 1990 JET operated with a number of technical improvements which led to advances in performance and permitted the carrying out of experiments specifically aimed at improving physics understanding of selected topics relevant to the "NEXT STEP". The new facilities include beryllium antenna screens, a prototype lower hybrid current drive system, and modification of the NI system to enable the injection of He-3 and He-4. Continued investigation of the hot-ion H-mode produced a value of n(D)(0)tau-E(T)(i)(0) = 9 x 10(20)m-3s keV, which is near conditions required for Q(DT) = 1, while a new peaked density profile H-mode was developed with only slightly lower performance. Progress towards steady state operation has been made by achieving ELMy H-modes under certain operating conditions, while maintaining good tau-E values. Experimental simulation of He ash transport indicates effective removal of alpha-particles from the plasma core for both L and H mode plasmas. Detailed analyses of particle and energy transport have helped establish a firmer link between particle and energy transport, and have suggested a connection between reduced energy transport and reversed shear. Numerical and analytic studies of divertor physics carried out for the pumped divertor phase of JET have helped clarify the key parameters governing impurity retention, and an intensive model validation effort has begun. Experimental simulation of alpha-particle effects with beta-fast up to 8% have shown that the slowing down processes are classical, and have given no evidence of deleterious collective effects. C1 UKAEA,HARWELL OX11 0RA,BERKS,ENGLAND. UNIV LEICESTER,LEICESTER LE1 7RH,ENGLAND. ACAD SCI BUDAPEST,CENT RES INST PHYS,BUDAPEST,HUNGARY. UNIV ESSEX,COLCHESTER CO4 3SQ,ESSEX,ENGLAND. ENTE NAZL ENERGIA ATOM,CNR,PADUA,ITALY. PRINCETON PLASMA PHYS LAB,PRINCETON,NJ. UKAEA,CULHAM LAB,ABINGDON OX14 3DB,OXON,ENGLAND. UNIV COMPLUTENSE MADRID,MADRID 3,SPAIN. UNIV OXFORD,INST MATH,OXFORD,ENGLAND. FREE UNIV BERLIN,W-1000 BERLIN 33,GERMANY. SWEDISH ENERGY COMMISS,S-10072 STOCKHOLM,SWEDEN. UNIV LONDON IMPERIAL COLL SCI & TECHNOL,LONDON SW7 2AZ,ENGLAND. MAX PLANCK INST PLASMA PHYS,W-8046 GARCHING,GERMANY. RISO NATL LAB,DK-4000 ROSKILDE,DENMARK. FOM,INST PLASMAFYS,3430 BE NIEWWEGEIN,NETHERLANDS. UNIV LUND,S-22101 LUND,SWEDEN. N CAROLINA STATE UNIV,RALEIGH,NC 27695. UNIV TORONTO,INST AEROSP STUDIES,TORONTO M3H 5T6,ONTARIO,CANADA. UNIV STRATHCLYDE,GLASGOW G1 1XW,SCOTLAND. LAPEENRANTA UNIV,NUCL ENGN LAB,LAPEENRANTA,FINLAND. CIEMAT,MADRID,SPAIN. INST NUCL STUDIES,OTWOCK,POLAND. IV KURCHATOV ATOM ENERGY INST,MOSCOW,USSR. UNIV HEIDELBERG,W-6900 HEIDELBERG,GERMANY. CHINESE ACAD SCI,INST MECH,BEIJING,PEOPLES R CHINA. SOUTHWESTERN UNIV PHYS,LESHAN,PEOPLES R CHINA. RCC CYFRONET,OTWOCK,POLAND. CNEN,I-00044 FRASCATI,ITALY. JAPAN ATOM ENERGY RES INST,NAKA FUS RES ESTAB,IBARAKI,JAPAN. RP KEILHACKER, M (reprint author), JET JOINT UNDERTATING,ABINGDON OX14 3EA,OXON,ENGLAND. RI Hammett, Gregory/D-1365-2011; Nave, Maria/A-5581-2013 OI Hammett, Gregory/0000-0003-1495-6647; Nave, Maria/0000-0003-2078-6584 NR 42 TC 20 Z9 21 U1 2 U2 5 PU IOP PUBLISHING LTD PI BRISTOL PA TECHNO HOUSE, REDCLIFFE WAY, BRISTOL, ENGLAND BS1 6NX SN 0741-3335 J9 PLASMA PHYS CONTR F JI Plasma Phys. Control. Fusion PD NOV PY 1991 VL 33 IS 13 BP 1453 EP 1477 PG 25 WC Physics, Fluids & Plasmas SC Physics GA GV336 UT WOS:A1991GV33600002 ER PT J AU HAWRYLUK, RJ ARUNASALAM, V BARNES, CW BEER, M BELL, M BELL, R BIGLARI, H BITTER, M BOIVIN, R BRETZ, NL BUDNY, R BUSH, CE CHENG, CZ CHU, TK COHEN, SA COWLEY, S EFTHIMION, PC FONCK, RJ FREDRICKSON, E FURTH, HP GOLDSTON, RJ GREENE, G GREK, B GRISHAM, LR HAMMETT, G HEIDBRINK, W HILL, KW HOSEA, J HULSE, RA HSUAN, H JANOS, A JASSBY, D JOBES, FC JOHNSON, DW JOHNSON, LC KESNER, J KIERASPHILLIPS, C KILPATRICK, SJ KUGEL, H LAMARCHE, PH LEBLANC, B MANOS, DM MANSFIELD, DK MARMAR, ES MAZZUCATO, E MCCARTHY, MP MAUEL, M MCCUNE, DC MCGUIRE, KM MEADE, DM MEDLEY, SS MIKKELSEN, DR MONTICELLO, D MOTLEY, R MUELLER, D NAGAYAMA, Y NAVRATIL, GA NAZIKIAN, R OWENS, DK PARK, H PARK, W PAUL, S PERKINS, F PITCHER, S RAMSEY, AT REDI, MH REWOLDT, G ROBERTS, D ROQUEMORE, AL RUTHERFORD, PH SABBAGH, S SCHILLING, G SCHIVELL, J SCHMIDT, GL SCOTT, SD SNIPES, J STEVENS, J STRATTON, BC STODIEK, W SYNAKOWSKI, E TAKASE, Y TANG, W TAYLOR, G TERRY, J TIMBERLAKE, JR TOWNER, HH ULRICKSON, M VONGOELER, S WIELAND, R WILLIAMS, M WILSON, JR WONG, KL YAMADA, M YOSHIKAWA, S YOUNG, KM ZARNSTORFF, MC ZWEBEN, SJ AF HAWRYLUK, RJ ARUNASALAM, V BARNES, CW BEER, M BELL, M BELL, R BIGLARI, H BITTER, M BOIVIN, R BRETZ, NL BUDNY, R BUSH, CE CHENG, CZ CHU, TK COHEN, SA COWLEY, S EFTHIMION, PC FONCK, RJ FREDRICKSON, E FURTH, HP GOLDSTON, RJ GREENE, G GREK, B GRISHAM, LR HAMMETT, G HEIDBRINK, W HILL, KW HOSEA, J HULSE, RA HSUAN, H JANOS, A JASSBY, D JOBES, FC JOHNSON, DW JOHNSON, LC KESNER, J KIERASPHILLIPS, C KILPATRICK, SJ KUGEL, H LAMARCHE, PH LEBLANC, B MANOS, DM MANSFIELD, DK MARMAR, ES MAZZUCATO, E MCCARTHY, MP MAUEL, M MCCUNE, DC MCGUIRE, KM MEADE, DM MEDLEY, SS MIKKELSEN, DR MONTICELLO, D MOTLEY, R MUELLER, D NAGAYAMA, Y NAVRATIL, GA NAZIKIAN, R OWENS, DK PARK, H PARK, W PAUL, S PERKINS, F PITCHER, S RAMSEY, AT REDI, MH REWOLDT, G ROBERTS, D ROQUEMORE, AL RUTHERFORD, PH SABBAGH, S SCHILLING, G SCHIVELL, J SCHMIDT, GL SCOTT, SD SNIPES, J STEVENS, J STRATTON, BC STODIEK, W SYNAKOWSKI, E TAKASE, Y TANG, W TAYLOR, G TERRY, J TIMBERLAKE, JR TOWNER, HH ULRICKSON, M VONGOELER, S WIELAND, R WILLIAMS, M WILSON, JR WONG, KL YAMADA, M YOSHIKAWA, S YOUNG, KM ZARNSTORFF, MC ZWEBEN, SJ TI OVERVIEW OF TFTR TRANSPORT STUDIES SO PLASMA PHYSICS AND CONTROLLED FUSION LA English DT Article; Proceedings Paper CT 18TH EUROPEAN CONF ON CONTROLLED FUSION AND PLASMA PHYSICS CY JUN 03-07, 1991 CL BERLIN, GERMANY SP EUROPEAN PHYS SOC, DIV PLASMA PHYS ID GRADIENT-DRIVEN TURBULENCE; HEAT-PULSE-PROPAGATION; NEUTRAL BEAM INJECTION; ENHANCED-CONFINEMENT; DRIFT INSTABILITIES; ANOMALOUS TRANSPORT; ENERGY CONFINEMENT; TOKAMAK; PLASMAS; FLUCTUATIONS AB A review of TFTR plasma transport studies is presented. Parallel transport and the confinement of suprathermal ions are found to be relatively well described by theory. Cross-field transport of the thermal plasma, however, is anomalous with the momentum diffusivity being comparable to the ion thermal diffusivity and larger than the electron thermal diffusivity in neutral beam heated discharges. Perturbative experiments have studied non-linear dependencies in the transport coefficients and examined the role of possible non-local phenomena. The underlying turbulence has been studied using microwave scattering, beam emission spectroscopy and microwave reflectometry over a much broader range in k perpendicular-to than previously possible. Results indicate the existence of large-wavelength fluctuations correlated with enhanced transport. MHD instabilities set important operational constraints. However, by modifying the current profile using current ramp-down techniques, it has been possible to extend the operating regime to higher values of both epsilon-beta-p and normalized beta-T. In addition, the interaction of MHD fluctuations with fast ions, of potential relevance to alpha - particle confinement in D-T plasmas, has been investigated. The installation of carbon-carbon composite tiles and improvements in wall conditioning, in particular the use of Li pellet injection to reduce the carbon recycling, continue to be important in the improvement of plasma performance. C1 OAK RIDGE NATL LAB,OAK RIDGE,TN. CANADIAN FUS FUELS TECHNOL PROJECT,TORONTO,ONTARIO,CANADA. UNIV CALIF LOS ALAMOS SCI LAB,LOS ALAMOS,NM 87544. UNIV WISCONSIN,MADISON,WI 53706. UNIV CALIF IRVINE,IRVINE,CA 92717. MIT,CAMBRIDGE,MA 02139. COLUMBIA UNIV,NEW YORK,NY 10027. UNIV TOKYO,TOKYO 113,JAPAN. RP HAWRYLUK, RJ (reprint author), PRINCETON UNIV,PLASMA PHYS LAB,POB 451,PRINCETON,NJ 08543, USA. RI Sabbagh, Steven/C-7142-2011; Hammett, Gregory/D-1365-2011; Cheng, Chio/K-1005-2014; Yamada, Masaaki/D-7824-2015; OI Hammett, Gregory/0000-0003-1495-6647; Yamada, Masaaki/0000-0003-4996-1649; Mauel, Michael/0000-0003-2490-7478 NR 96 TC 57 Z9 57 U1 1 U2 6 PU IOP PUBLISHING LTD PI BRISTOL PA TECHNO HOUSE, REDCLIFFE WAY, BRISTOL, ENGLAND BS1 6NX SN 0741-3335 J9 PLASMA PHYS CONTR F JI Plasma Phys. Control. Fusion PD NOV PY 1991 VL 33 IS 13 BP 1509 EP 1536 DI 10.1088/0741-3335/33/13/005 PG 28 WC Physics, Fluids & Plasmas SC Physics GA GV336 UT WOS:A1991GV33600005 ER PT J AU MOREAU, D GORMEZANO, C AGARICI, G AGOSTINI, E ANE, JM AUGE, N BALME, S BASIUK, V BAREYT, B BAYETTI, P BEAUMONT, B BECHERER, R BECOULET, A BENKADDA, M BERGERBY, G BESSETTE, D BIBET, P BIZARRO, JP BONMARDION, G BONNEL, P BOTTEREAU, JM BOTTIGLIONI, F BRUGNETTI, R BRUNEAU, JL BURAVAND, Y CAPES, H CAPITAIN, JJ CHAPPUIS, P CHATAIN, D CHATELIER, A CHATELIER, M CIAZYNSKI, D CORDIER, JJ COSTON, JF COULON, JP COUTURIER, B CRENN, JP DECK, C DEGENTILE, B DEMARTHE, H DEMICHELIS, C DESCHAMPS, P DEVYNCK, P DOCEUL, L DOUGNAC, M DRAWIN, HW DUBOIS, M DUCHATEAU, JL DUPAS, L EDERY, D ELBEZE, D EVANS, T FALL, T FARJON, JL FIDONE, I FOIS, M FOSTER, CA FUMELLI, M GAGEY, B GARBET, X GAUTHIER, E GERAUD, A GERVAIS, F GENDRIH, P GIL, C GIRUZZI, G GONICHE, M GRAVIER, R GRAVIL, B GREGOIRE, M GRESILLON, D GRISOLIA, C GROSMAN, A GUILHEM, D GUILLERMINET, B HENNEQUIN, P HENNION, F HERTOUT, P HESS, WR HESSE, M HOANG, GT HORTON, L HUBBARD, A HUTTER, T IDMTAL, J JACQUOT, C JAGER, B JAVON, C JEQUIER, F JOFFRIN, E JOHNER, J JOURNEAUX, JY JOYER, P KUUS, H LAFON, D LASALLE, J LAURENT, L LAVIRON, C LECLERT, G LECOUSTEY, P LELOUP, C LIBEYRE, P LIPA, M LITAUDON, X LOARER, T LOTTE, P MAGAUD, P MAGNE, R MARTIN, G MARTINEZ, A MASCHKE, EK MATTIOLI, M MAYAUX, G MIODUSZEWSKI, P MISGUICH, J MONIERGARBET, P MOREAU, D MORERA, JP MORET, JM MOULIN, B MOULIN, D MOURGUESMILLOT, F MOUSTIER, M NGUYEN, F OLIVAIN, J OUVRIERBUFFET, P PAMELA, J PANZARELLA, A PARLANGE, F PASTOR, G PATRIS, R PAUME, M PECQUET, AL PEGOURIE, B PEYSSON, Y PIAT, D PICCHIOTTINO, JM PIERRE, J PLATZ, P PORTAFAIX, C POUTCHY, F PROU, M QUEMENEUR, A RAX, JM REY, G RIBAND, P RIGAUD, D RODRIGUEZ, L ROTHAN, B ROUBIN, JP ROUSSEL, P SAHA, SK SAMAILLE, F SAMAIN, A SAOUTIC, B SCHLOSSER, J SEIGNEUR, A SEGUI, JL SHEPARD, T SOLER, K STIRLING, W TACHON, J TALVARD, M TONON, G TOROSSIAN, A TRUC, A TURCK, B UCKAN, T VALLET, JC VANHOUTTE, D WEISSE, J ZOU, XL AF MOREAU, D GORMEZANO, C AGARICI, G AGOSTINI, E ANE, JM AUGE, N BALME, S BASIUK, V BAREYT, B BAYETTI, P BEAUMONT, B BECHERER, R BECOULET, A BENKADDA, M BERGERBY, G BESSETTE, D BIBET, P BIZARRO, JP BONMARDION, G BONNEL, P BOTTEREAU, JM BOTTIGLIONI, F BRUGNETTI, R BRUNEAU, JL BURAVAND, Y CAPES, H CAPITAIN, JJ CHAPPUIS, P CHATAIN, D CHATELIER, A CHATELIER, M CIAZYNSKI, D CORDIER, JJ COSTON, JF COULON, JP COUTURIER, B CRENN, JP DECK, C DEGENTILE, B DEMARTHE, H DEMICHELIS, C DESCHAMPS, P DEVYNCK, P DOCEUL, L DOUGNAC, M DRAWIN, HW DUBOIS, M DUCHATEAU, JL DUPAS, L EDERY, D ELBEZE, D EVANS, T FALL, T FARJON, JL FIDONE, I FOIS, M FOSTER, CA FUMELLI, M GAGEY, B GARBET, X GAUTHIER, E GERAUD, A GERVAIS, F GENDRIH, P GIL, C GIRUZZI, G GONICHE, M GRAVIER, R GRAVIL, B GREGOIRE, M GRESILLON, D GRISOLIA, C GROSMAN, A GUILHEM, D GUILLERMINET, B HENNEQUIN, P HENNION, F HERTOUT, P HESS, WR HESSE, M HOANG, GT HORTON, L HUBBARD, A HUTTER, T IDMTAL, J JACQUOT, C JAGER, B JAVON, C JEQUIER, F JOFFRIN, E JOHNER, J JOURNEAUX, JY JOYER, P KUUS, H LAFON, D LASALLE, J LAURENT, L LAVIRON, C LECLERT, G LECOUSTEY, P LELOUP, C LIBEYRE, P LIPA, M LITAUDON, X LOARER, T LOTTE, P MAGAUD, P MAGNE, R MARTIN, G MARTINEZ, A MASCHKE, EK MATTIOLI, M MAYAUX, G MIODUSZEWSKI, P MISGUICH, J MONIERGARBET, P MOREAU, D MORERA, JP MORET, JM MOULIN, B MOULIN, D MOURGUESMILLOT, F MOUSTIER, M NGUYEN, F OLIVAIN, J OUVRIERBUFFET, P PAMELA, J PANZARELLA, A PARLANGE, F PASTOR, G PATRIS, R PAUME, M PECQUET, AL PEGOURIE, B PEYSSON, Y PIAT, D PICCHIOTTINO, JM PIERRE, J PLATZ, P PORTAFAIX, C POUTCHY, F PROU, M QUEMENEUR, A RAX, JM REY, G RIBAND, P RIGAUD, D RODRIGUEZ, L ROTHAN, B ROUBIN, JP ROUSSEL, P SAHA, SK SAMAILLE, F SAMAIN, A SAOUTIC, B SCHLOSSER, J SEIGNEUR, A SEGUI, JL SHEPARD, T SOLER, K STIRLING, W TACHON, J TALVARD, M TONON, G TOROSSIAN, A TRUC, A TURCK, B UCKAN, T VALLET, JC VANHOUTTE, D WEISSE, J ZOU, XL TI LOWER HYBRID CURRENT DRIVE IN TORE SUPRA AND JET SO PLASMA PHYSICS AND CONTROLLED FUSION LA English DT Article; Proceedings Paper CT 18TH EUROPEAN CONF ON CONTROLLED FUSION AND PLASMA PHYSICS CY JUN 03-07, 1991 CL BERLIN, GERMANY SP EUROPEAN PHYS SOC, DIV PLASMA PHYS DE TOKAMAKS; TORE SUPRA; JET; CURRENT DRIVE; LOWER HYBRID WAVE; FAST WAVE; SYNERGY; TRANSIT TIME MAGNETIC PUMPING; SAWTOOTH SUPPRESSION; ANOMALOUS TRANSPORT; PELLET INJECTION ID TOKAMAKS; ENERGY AB Recent Lower Hybrid Current Drive (LHCD) experiments in TORE SUPRA and JET are reported. Large multijunction launchers have allowed the coupling of 5 MW to the plasma for several seconds with a maximum of 3.8 kw/cm2. Measurements of the scattering matrices of the antennae show good agreement with theory. The current drive efficiency in TORE SUPRA is about 0.2 x 10(20) Am-2/W with LH power alone and reaches 0.4 x 10(20) Am-2/W in JET thanks to a high volume-averaged electron temperature (1.9 keV) and also to a synergy between Lower Hybrid and Fast Magnetosonic Waves. At N(e)BAR = 1.5 x 10(19) m-3 in TORE SUPRA, sawteeth are suppressed and m = 1 MHD oscillations the frequency of which clearly depends on the amount of LH power are observed on soft x-rays, and also on non-thermal ECE. In JET ICRH produced sawtooth-free periods are extended by the application of LHCD (2.9 s. with 4 MW ICRH) and current profile broadening has been clearly observed consistent with off-axis fast electron populations. LH power modulation experiments performed in TORE SUPRA at N(e)BAR = 4 x 10(19) m-3 show a delayed central electron heating despite the off-axis creation of suprathermal electrons, thus ruling out the possibility of a direct heating through central wave absorption. A possible explanation in terms of anomlous fast electron transport and classical slowing down would yield a diffusion coefficient of the order of 10 m2/s for the fast electrons. Other interpretations such as an anomalous heat pinch or a central confinement enhancement cannot be excluded. Finally, successful pellet fuelling of a partially LH driven plasma was obtained in TORE SUPRA, 28 successive pellets allowing the density to rise to N(e)BAR = 4 x 10(19) m-3. This could be achieved by switching the LH power off for 90 ms before each pellet injection, i.e. without modifying significantly the current density profile. C1 JET JOINT UNDERTAKING,ABINGDON OX14 3EA,OXON,ENGLAND. GEN ATOM,SAN DIEGO,CA. OAK RIDGE NATL LAB,OAK RIDGE,TN. CTR CANADIEN FUS MAGNET,VARENNES,QUEBEC,CANADA. ECOLE POLYTECH,PMI,F-91128 PALAISEAU,FRANCE. UNIV NANCY 1,LPMI,F-54506 VANDOEUVRE NANCY,FRANCE. ECOLE POLYTECH FED LAUSANNE,CRPP,CH-1007 LAUSANNE,SWITZERLAND. RP MOREAU, D (reprint author), CTR ETUD CADARACHE,DEPT RECH FUS CONTROLEE,F-13108 ST PAUL DURANCE,FRANCE. RI GAUTHIER, Eric/E-1076-2011; Bizarro, Joao P. S./F-4124-2011 OI Bizarro, Joao P. S./0000-0002-0698-6259 NR 35 TC 21 Z9 21 U1 3 U2 16 PU IOP PUBLISHING LTD PI BRISTOL PA TECHNO HOUSE, REDCLIFFE WAY, BRISTOL, ENGLAND BS1 6NX SN 0741-3335 J9 PLASMA PHYS CONTR F JI Plasma Phys. Control. Fusion PD NOV PY 1991 VL 33 IS 13 BP 1621 EP 1638 DI 10.1088/0741-3335/33/13/010 PG 18 WC Physics, Fluids & Plasmas SC Physics GA GV336 UT WOS:A1991GV33600010 ER PT J AU JACQUINOT, J ADAMS, JM ALTMANN, H ANDERSEN, A ANDREW, P ANGELONE, M ARSHAD, SA BAILEY, W BALLANTYNE, P BALET, B BARABASCHI, P BARNSLEY, R BARONIAN, M BARTLETT, DV BELL, AC BENFATTO, I BENALI, G BERGSAKER, H BERTOLDI, P BERTOLINI, E BHATNAGAR, V BICKLEY, AJ BINDSLEV, H BONICELLI, T BOOTH, SJ BOSIA, G BOTMAN, M BOUCHER, D BOUCQUEY, P BREGER, P BRELEN, H BRINKSCHULTE, H BROWN, T BRUSATI, M BUDD, T BURES, M BUSINARO, T BUTCHER, P BUTTGEREIT, H CALDWELLNICHOLS, C CAMPBELL, DJ CARD, P CELENTANO, G CHALLIS, CD CHANKIN, AV CHIRON, D CHRISTIANSEN, J CHRISTODOULOPOULOS, C CHUILON, P CLAESEN, R CLEMENT, S CLIPSHAM, E COAD, JP COMISKEY, M CONROY, S COOKE, M COOPER, S CORDEY, JG CORE, W CORRIGAN, G CORTI, S COSTLEY, AE COTTRELL, G COX, M CRIPWELL, P DEBLANK, H DEESCH, H DEKOCK, L DEKSNIS, E DENNEHINNOV, GB DESCHAMPS, G DIETZ, KJ DMITRENKO, SL DOBBING, J DOLGETTA, N DORLING, SE DOYLE, PG DUCHS, DF DUQUENOY, H EDWARDS, A EHRENBERG, J EKEDAHL, A ELEVANT, T ERENTS, SK ERIKSSON, LG FAJEMIROKUN, H FALTER, H FLORY, D FREILING, J FROGER, C FROISSARD, P FULLARD, K GADEBERG, M GALETSAS, A GAMBIER, D GARRIBBA, M GAZE, P GIANNELLA, R GIBSON, A GILL, RD GIRARD, A GONDHALEKAR, A GORMEZANO, C GOTTARDI, NA GOWERS, C GREEN, BJ HAANGE, R HAAS, G HAIGH, A HAMMETT, G HANCOCK, CJ HARBOUR, PJ HAWKES, NC HAYNES, P HEMMERICH, JL HENDER, T HERZOG, FB HERZOG, RF HOEKZEMA, J HOW, J HUART, M HUGHES, I HUGHES, TP HUGON, M HUGUET, M HWANG, A INGRAM, B IRVING, M JAECKEL, H JAEGER, JF JANESCHITZ, G JANKOWICZ, S JARVIS, ON JENSEN, F JONES, EM JONES, LPDF JONES, TTC JUNGER, JF JUNIQUE, E KAYE, A KEEN, BE KEILHACKER, M KELLY, GJ KEMER, W KONIG, R KONSTANTELLOS, A KOVANEN, M KRAMER, G KUPSCHUS, P LASSER, R LAST, JR LAUNDY, B LAUROTARONI, L LAWSON, K LENNHOLM, M LOARTE, A LOBEL, R LOMAS, P LOUGHLIN, M LOWRY, C MACKLIN, B MADDISON, G MAGYAR, G MANDL, W MARCHESE, V MARCUS, F MART, J MARTIN, E MARTINSOLIS, R MASSMANN, P MCCRACKEN, G MERIGUET, P MIELE, P MILLS, SF MILLWARD, P MOHANTI, R MONDINO, PL MONTVAI, A MORIYAMA, S MORGAN, P MORSI, H MURPHY, G MYNARENDS, M MYRNAS, R NARDONE, C NAVE, F NEWBERT, G NEWMAN, M NIELSEN, P NOLL, P OBERT, W OBRIEN, D OROURKE, J OSTROM, R OTTAVIANI, M PAIN, M PAOLETTI, F PAPASTERGIOU, S PASINI, D PEACOCK, A PEACOCK, N PEARSON, D DESILVA, RP PERINIC, G PERRY, C PICK, M PITTS, R PLANCOULAINE, J POFFE, JP PORCELLI, F PORTE, L PRENTICE, R PUPPIN, S PUTVINSKO, S RADFORD, G RAIMONDI, T DEANDRADE, MCR REBUT, PH REICHLE, R RIGHI, E RIMINI, F ROBINSON, D ROLFE, A ROSS, RT ROSSI, L RUSS, R RUTTER, P SACK, HC SADLER, G SAIBENE, G SALANAVE, JL SANAZZARO, G SANTAGIUSTINA, A SARTORI, R SBORCHIA, C SCHILD, P SCHMID, M SCHMIDT, G SCHUNKE, B SCOTT, SM SIBLEY, A SIMONINI, R SIPS, ACC SMEULDERS, P STANKIEWICZ, R STAMP, M STANGEBY, P START, DF STEED, CA STORK, D STOTT, PE STRINGER, TE STUBBERFIELD, P SUMMERS, D SUMMERS, H SVENSSON, L TAGLE, JA TANGA, A TARONI, A TESINI, A THOMAS, PR THOMPSON, E THOMSEN, K TODD, JM TREVALION, P TUBBING, B TIBONE, F USSELMANN, E VANDERBEKEN, H VLASES, G VONHELLERMANN, M WADE, T WALKER, C WALTON, R WARD, D WATKINS, ML WATSON, MJ WEBER, S WESSON, J WIJNANDS, TJ WILKS, J WILSON, D WINKEL, T WOLF, R WOLLE, B WONG, D WOODWARD, C WU, Y WYKES, M YOUNG, ID ZANNELLI, L ZHU, Y ZWINGMANN, W AF JACQUINOT, J ADAMS, JM ALTMANN, H ANDERSEN, A ANDREW, P ANGELONE, M ARSHAD, SA BAILEY, W BALLANTYNE, P BALET, B BARABASCHI, P BARNSLEY, R BARONIAN, M BARTLETT, DV BELL, AC BENFATTO, I BENALI, G BERGSAKER, H BERTOLDI, P BERTOLINI, E BHATNAGAR, V BICKLEY, AJ BINDSLEV, H BONICELLI, T BOOTH, SJ BOSIA, G BOTMAN, M BOUCHER, D BOUCQUEY, P BREGER, P BRELEN, H BRINKSCHULTE, H BROWN, T BRUSATI, M BUDD, T BURES, M BUSINARO, T BUTCHER, P BUTTGEREIT, H CALDWELLNICHOLS, C CAMPBELL, DJ CARD, P CELENTANO, G CHALLIS, CD CHANKIN, AV CHIRON, D CHRISTIANSEN, J CHRISTODOULOPOULOS, C CHUILON, P CLAESEN, R CLEMENT, S CLIPSHAM, E COAD, JP COMISKEY, M CONROY, S COOKE, M COOPER, S CORDEY, JG CORE, W CORRIGAN, G CORTI, S COSTLEY, AE COTTRELL, G COX, M CRIPWELL, P DEBLANK, H DEESCH, H DEKOCK, L DEKSNIS, E DENNEHINNOV, GB DESCHAMPS, G DIETZ, KJ DMITRENKO, SL DOBBING, J DOLGETTA, N DORLING, SE DOYLE, PG DUCHS, DF DUQUENOY, H EDWARDS, A EHRENBERG, J EKEDAHL, A ELEVANT, T ERENTS, SK ERIKSSON, LG FAJEMIROKUN, H FALTER, H FLORY, D FREILING, J FROGER, C FROISSARD, P FULLARD, K GADEBERG, M GALETSAS, A GAMBIER, D GARRIBBA, M GAZE, P GIANNELLA, R GIBSON, A GILL, RD GIRARD, A GONDHALEKAR, A GORMEZANO, C GOTTARDI, NA GOWERS, C GREEN, BJ HAANGE, R HAAS, G HAIGH, A HAMMETT, G HANCOCK, CJ HARBOUR, PJ HAWKES, NC HAYNES, P HEMMERICH, JL HENDER, T HERZOG, FB HERZOG, RF HOEKZEMA, J HOW, J HUART, M HUGHES, I HUGHES, TP HUGON, M HUGUET, M HWANG, A INGRAM, B IRVING, M JAECKEL, H JAEGER, JF JANESCHITZ, G JANKOWICZ, S JARVIS, ON JENSEN, F JONES, EM JONES, LPDF JONES, TTC JUNGER, JF JUNIQUE, E KAYE, A KEEN, BE KEILHACKER, M KELLY, GJ KEMER, W KONIG, R KONSTANTELLOS, A KOVANEN, M KRAMER, G KUPSCHUS, P LASSER, R LAST, JR LAUNDY, B LAUROTARONI, L LAWSON, K LENNHOLM, M LOARTE, A LOBEL, R LOMAS, P LOUGHLIN, M LOWRY, C MACKLIN, B MADDISON, G MAGYAR, G MANDL, W MARCHESE, V MARCUS, F MART, J MARTIN, E MARTINSOLIS, R MASSMANN, P MCCRACKEN, G MERIGUET, P MIELE, P MILLS, SF MILLWARD, P MOHANTI, R MONDINO, PL MONTVAI, A MORIYAMA, S MORGAN, P MORSI, H MURPHY, G MYNARENDS, M MYRNAS, R NARDONE, C NAVE, F NEWBERT, G NEWMAN, M NIELSEN, P NOLL, P OBERT, W OBRIEN, D OROURKE, J OSTROM, R OTTAVIANI, M PAIN, M PAOLETTI, F PAPASTERGIOU, S PASINI, D PEACOCK, A PEACOCK, N PEARSON, D DESILVA, RP PERINIC, G PERRY, C PICK, M PITTS, R PLANCOULAINE, J POFFE, JP PORCELLI, F PORTE, L PRENTICE, R PUPPIN, S PUTVINSKO, S RADFORD, G RAIMONDI, T DEANDRADE, MCR REBUT, PH REICHLE, R RIGHI, E RIMINI, F ROBINSON, D ROLFE, A ROSS, RT ROSSI, L RUSS, R RUTTER, P SACK, HC SADLER, G SAIBENE, G SALANAVE, JL SANAZZARO, G SANTAGIUSTINA, A SARTORI, R SBORCHIA, C SCHILD, P SCHMID, M SCHMIDT, G SCHUNKE, B SCOTT, SM SIBLEY, A SIMONINI, R SIPS, ACC SMEULDERS, P STANKIEWICZ, R STAMP, M STANGEBY, P START, DF STEED, CA STORK, D STOTT, PE STRINGER, TE STUBBERFIELD, P SUMMERS, D SUMMERS, H SVENSSON, L TAGLE, JA TANGA, A TARONI, A TESINI, A THOMAS, PR THOMPSON, E THOMSEN, K TODD, JM TREVALION, P TUBBING, B TIBONE, F USSELMANN, E VANDERBEKEN, H VLASES, G VONHELLERMANN, M WADE, T WALKER, C WALTON, R WARD, D WATKINS, ML WATSON, MJ WEBER, S WESSON, J WIJNANDS, TJ WILKS, J WILSON, D WINKEL, T WOLF, R WOLLE, B WONG, D WOODWARD, C WU, Y WYKES, M YOUNG, ID ZANNELLI, L ZHU, Y ZWINGMANN, W TI HEATING, CURRENT DRIVE AND CONFINEMENT REGIMES WITH THE JET ICRH AND LHCD SYSTEMS SO PLASMA PHYSICS AND CONTROLLED FUSION LA English DT Article; Proceedings Paper CT 18TH EUROPEAN CONF ON CONTROLLED FUSION AND PLASMA PHYSICS CY JUN 03-07, 1991 CL BERLIN, GERMANY SP EUROPEAN PHYS SOC, DIV PLASMA PHYS DE ICRH; LHCD; H-MODE; L-MODE; HEATING; CONFINEMENT; FUSION YIELD; PEAKED DENSITY PROFILES; ANTENNA SCREEN; EDGE PHYSICS; SYNERGISTIC EFFECTS; CURRENT DRIVE ID TOKAMAKS; PLASMA; ENERGY; MODE AB During its 1990 operation, 2 large RF systems were available on JET. The Ion Cyclotron Resonance Heating (ICRH) system was equipped with new beryllium screens and with feedback matching systems. Specific impurities generated by ICRH were reduced to negligible levels even in the most stringent H-mode conditions. A maximum power of 22 MW was coupled to L-mode plasmas. High quality H-modes (tau-E greater-than-or-equal-to 2.5 tau-EG) were achieved using dipole phasing. A new high confinement mode was discovered. It combines the properties of the H-mode regime to the low central diffusivities obtained by pellet injection. A value of n(d) tau-E T(i) = 7.8 x 10(20) m-3 s keV was obtained in this mode with T(e) approximately T(i) approximately 11 keV. In the L-mode regime, a regime, a record (140 kW) D-He-3 fusion power was generated with 10 - 14 MW of ICRH at the He-3 cyclotron frequency. Experiments were performed with the prototype launcher of the Lower Hybrid Current Drive (LHCD) systems with coupled power up to 1.6 MW with current drive efficiencies up to < n(e) > R I(CD)/P = 0.4 x 10(20) m-2 A/W. Fast electrons are driven by LHCD to tail temperatures of 100 keV with a hollow radial profile. Paradoxically, LHCD induces central heating particularly in combination with ICRH. Finally we present the first observations of the synergistic acceleration of fast electrons by Transit Time Magnetic Pumping (TTMP) (from ICRH) and Electron Landau Damping (ELD) (from LHCD). The synergism generates TTMP current drive even without phasing the ICRH antennae. C1 UKAEA,HARWELL OX11 0RA,BERKS,ENGLAND. UNIV LEICESTER,LEICESTER LE1 7RH,ENGLAND. ACAD SCI BUDAPEST,CENT RES INST PHYS,BUDAPEST,HUNGARY. UNIV ESSEX,COLCHESTER CO4 3SQ,ESSEX,ENGLAND. ENTE NAZL ENERGIA ATOM,CNR,PADUA,ITALY. PRINCETON PLASMA PHYS LAB,PRINCETON,NJ. UKAEA,CULHAM LAB,ABINGDON OX14 3DB,OXON,ENGLAND. UNIV COMPLUTENSE MADRID,MADRID 3,SPAIN. UNIV OXFORD,INST MATH,OXFORD,ENGLAND. FREE UNIV BERLIN,W-1000 BERLIN 33,GERMANY. SWEDISH ENERGY COMMISS,S-10072 STOCKHOLM,SWEDEN. UNIV LONDON IMPERIAL COLL SCI & TECHNOL,LONDON SW7 2AZ,ENGLAND. MAX PLANCK INST PLASMA PHYS,W-8046 GARCHING,GERMANY. RISO NATL LAB,DK-4000 ROSKILDE,DENMARK. FOM,INST PLASMAFYS,3430 BE NIEWWEGEIN,NETHERLANDS. UNIV LUND,S-22101 LUND,SWEDEN. N CAROLINA STATE UNIV,RALEIGH,NC 27695. UNIV TORONTO,INST AEROSP STUDIES,TORONTO M3H 5T6,ONTARIO,CANADA. UNIV STRATHCLYDE,GLASGOW G1 1XW,SCOTLAND. LAPEENRANTA UNIV,NUCL ENGN LAB,LAPEENRANTA,FINLAND. CIEMAT,MADRID,SPAIN. INST NUCL STUDIES,OTWOCK,POLAND. IV KURCHATOV ATOM ENERGY INST,MOSCOW,USSR. UNIV HEIDELBERG,W-6900 HEIDELBERG,GERMANY. CHINESE ACAD SCI,INST MECH,BEIJING,PEOPLES R CHINA. SOUTHWESTERN UNIV PHYS,LESHAN,PEOPLES R CHINA. RCC CYFRONET,OTWOCK,POLAND. CNEN,I-00044 FRASCATI,ITALY. JAPAN ATOM ENERGY RES INST,NAKA FUS RES ESTAB,IBARAKI,JAPAN. RP JACQUINOT, J (reprint author), JET JOINT UNDERTATING,ABINGDON OX14 3EA,OXON,ENGLAND. RI Hammett, Gregory/D-1365-2011; Nave, Maria/A-5581-2013 OI Hammett, Gregory/0000-0003-1495-6647; Nave, Maria/0000-0003-2078-6584 NR 36 TC 31 Z9 31 U1 1 U2 7 PU IOP PUBLISHING LTD PI BRISTOL PA TECHNO HOUSE, REDCLIFFE WAY, BRISTOL, ENGLAND BS1 6NX SN 0741-3335 J9 PLASMA PHYS CONTR F JI Plasma Phys. Control. Fusion PD NOV PY 1991 VL 33 IS 13 BP 1657 EP 1675 DI 10.1088/0741-3335/33/13/012 PG 19 WC Physics, Fluids & Plasmas SC Physics GA GV336 UT WOS:A1991GV33600012 ER PT J AU BATISTONI, P BARNES, CW AF BATISTONI, P BARNES, CW TI COMPUTATION OF CLASSICAL TRITON BURNUP WITH HIGH PLASMA TEMPERATURE AND CURRENT SO PLASMA PHYSICS AND CONTROLLED FUSION LA English DT Article ID TFTR TOKAMAK; TRANSPORT; CALIBRATION; MOMENTUM; HEAT AB For comparison with experiment, the expected production of 14-MeV neutrons from the burnup of tritons produced in the d(d, t)p reaction must be computed. An effort was undertaken to compare in detail the computer codes used for this purpose at TFTR and JET. The calculation of the confined fraction of tritons by the different codes agrees to within a few per cent. The high electron temperature in the experiments has raised the critical energy (where ion drag equals electron drag) of the tritons that are slowing down to near or above the peak of the D-T reactivity, making the ion drag terms more important. When the different codes use the same slowing-down formulas, the calculated burnup was within 6% for a case where orbit effects are expected to be small. Then results from codes with and without the effects of finite radial orbit excursions were compared for two test cases. For medium to high current discharges the finite radius effects are only of the order of 10%. A new version of the TFTR burnup code using an implicit Fokker-Planck solution was written to include the effects of energy diffusion and charge exchange. These effects change the time-integrated yields by only a few per cent, but can significantly affect the instantaneous rates in time. Significant populations of hot ions can affect the fusion reactivity, and this effect was also studied. In particular, the d(d, p)t rate can be 5 10% less than the d(d, He-3)n rate which is usually used as a direct monitor of the triton source. Finally, a finite (instead of the typical zero) particle confinement time for the thermalized tritons can increase the apparent "burnup" (by 30% for confinement of the order of the slowing-down time) either if there is a high thermal deuteron temperature or if there exists a significant beam deuteron density. C1 PRINCETON UNIV,PRINCETON PLASMA PHYS LAB,PRINCETON,NJ 08543. NR 30 TC 13 Z9 13 U1 0 U2 2 PU IOP PUBLISHING LTD PI BRISTOL PA TECHNO HOUSE, REDCLIFFE WAY, BRISTOL, ENGLAND BS1 6NX SN 0741-3335 J9 PLASMA PHYS CONTR F JI Plasma Phys. Control. Fusion PD NOV PY 1991 VL 33 IS 14 BP 1735 EP 1756 DI 10.1088/0741-3335/33/14/003 PG 22 WC Physics, Fluids & Plasmas SC Physics GA GV683 UT WOS:A1991GV68300003 ER PT J AU POWERS, M HOPPE, F GANNOTTI, J AF POWERS, M HOPPE, F GANNOTTI, J TI A QUICK, SIMPLE METHOD FOR THE DETERMINATION OF GOLD CONCENTRATION IN ELECTROPLATING SOLUTIONS BY HIGH-PERFORMANCE LIQUID-CHROMATOGRAPHY SO PLATING AND SURFACE FINISHING LA English DT Article ID COMPLEXES AB Separation and quantification of both gold(I) and gold(III) species are obtained by the application of High Performance Liquid Chromatography (HPLC) to the analysis of electroplating solutions. The method employs detection by conductivity and produces results in under ten minutes. Comparison of results achieved indicate accuracies that rival those of fire assay. C1 HEWLETT PACKARD CO,MICROWAVE TEST ACCESSORIES OPERAT,PALO ALTO,CA 94304. AT BROCHEM,MKT & SALES,MALVERN,PA. RP POWERS, M (reprint author), UNIV CALIF BERKELEY,LAWRENCE BERKELEY LAB,DIV MAT SCI 63203,1 CYCLOTRON RD,BERKELEY,CA 94720, USA. NR 8 TC 1 Z9 1 U1 0 U2 0 PU AMER ELECTROPLATERS SOC INC PI ORLANDO PA 12644 RESEARCH PKWY, ORLANDO, FL 32826-3298 SN 0360-3164 J9 PLAT SURF FINISH JI Plat. Surf. Finish. PD NOV PY 1991 VL 78 IS 11 BP 76 EP 78 PG 3 WC Metallurgy & Metallurgical Engineering; Materials Science, Coatings & Films SC Metallurgy & Metallurgical Engineering; Materials Science GA GN377 UT WOS:A1991GN37700016 ER PT J AU TAI, LW LESSING, PA AF TAI, LW LESSING, PA TI ADVANCED RESIN-INTERMEDIATE PROCESSING OF AGGLOMERATED POWDERS FOR PLASMA SPRAYING APPLICATIONS SO POWDER METALLURGY INTERNATIONAL LA English DT Article AB A method of preparing ceramic granules suitable for plasma spraying is described. Coarse, dense and sprayable agglomerates of Sr-doped lanthanum manganite (LSM) sized 100...200-mu-m were prepared via an advanced resin-intermediate process. This process is much more efficient than the conventional solid-state-reaction method in fabricating mixed-oxide powder of a large particle size and a narrow grain size distribution. The optimal molar ratio of citric acid/etyhlene glycol in the polymeric precursor was found to be 20/80 for forming a rigid resin and consequently large agglomerates. A minimum gel-to-nitrate ratio of 6/1 was recommended in preparing LSM particles suitable for plasma spraying. C1 EG&G IDAHO INC,CERAM SECT,IDAHO NATL ENGN LAB,IDAHO FALLS,ID 83415. RP TAI, LW (reprint author), UNIV MISSOURI,DEPT CERAM ENGN,ROLLA,MO 65401, USA. NR 8 TC 2 Z9 2 U1 0 U2 0 PU VERLAG SCHMID GMBH PI FREIBURG PA PO BOX 6609, D-79042 FREIBURG, GERMANY SN 0048-5012 J9 POWDER METALL INT PD NOV PY 1991 VL 23 IS 5 BP 301 EP 304 PG 4 WC Metallurgy & Metallurgical Engineering SC Metallurgy & Metallurgical Engineering GA GR807 UT WOS:A1991GR80700004 ER PT J AU RIVKIN, DB CASEY, LA AF RIVKIN, DB CASEY, LA TI THE RUSSIAN-REVOLUTION - PIPES,R SO PROBLEMS OF COMMUNISM LA English DT Book Review C1 US DEPT JUSTICE,WHITE HOUSE COUNSELS OFF,WASHINGTON,DC 20530. US DEPT JUSTICE,OFF POLICY DEV,WASHINGTON,DC 20530. GEORGE MASON UNIV,FAIRFAX,VA 22030. RP RIVKIN, DB (reprint author), US DOE,WASHINGTON,DC, USA. NR 1 TC 0 Z9 0 U1 0 U2 1 PU US GOVERNMENT PRINTING OFFICE PI WASHINGTON PA SUPT OF DOCUMENTS, WASHINGTON, DC 20402-9325 SN 0032-941X J9 PROBL COMMUNISM PD NOV-DEC PY 1991 VL 40 IS 6 BP 124 EP 134 PG 11 WC Economics; Political Science SC Business & Economics; Government & Law GA HC268 UT WOS:A1991HC26800016 ER PT J AU BJELDANES, LF KIM, JY GROSE, KR BARTHOLOMEW, JC BRADFIELD, CA AF BJELDANES, LF KIM, JY GROSE, KR BARTHOLOMEW, JC BRADFIELD, CA TI AROMATIC HYDROCARBON RESPONSIVENESS-RECEPTOR AGONISTS GENERATED FROM INDOLE-3-CARBINOL INVITRO AND INVIVO - COMPARISONS WITH 2,3,7,8-TETRACHLORODIBENZO-PARA-DIOXIN SO PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF THE UNITED STATES OF AMERICA LA English DT Article DE ANTICARCINOGEN; BRASSICA-OLERACEA; INDOLO[3,2-B]CARBAZOLE ID DIETARY INDOLE-3-CARBINOL; BRUSSELS-SPROUTS; AH RECEPTOR; BINDING; METABOLISM; INDUCTION; RAT; INDOLES; LIVER; CYTOCHROME-P1-450 AB Indole-3-carbinol (I3C) is a secondary plant metabolite produced in vegetables of the Brassica genus, including cabbage, cauliflower, and brussels sprouts. I3C is both an anti-initiator and a promoter of carcinogenesis. Consumption of I3C by humans and rodents can lead to marked increases in activities of cytochrome P-450-dependent monooxygenases and in a variety of phase II drug-metabolizing enzymes. We have reported previously that the enzyme-inducing activity of 13C is mediated through a mechanism requiring exposure of the compound to the low-pH environment of the stomach. We report here the aromatic hydrocarbon responsiveness-receptor K(d) values (22 nM-90 nM), determined with C57BL/6J mouse liver cytosol and the in vitro- and in vivo-molar yields (0.1-6%) of the major acid condensation products of 13C. We also show that indolo[3,2-b]carbazole (ICZ) is produced from 13C in yields on the order of 0.01% in vitro and, after oral intubation, in vivo. ICZ has a K(d) Of 190 pM for aromatic hydrocarbon responsiveness-receptor binding and an EC50 of 269 nM for induction of cytochrome P4501A1, as measured by ethoxyresorufin O-deethylase activity in murine hepatoma Hepa 1c1c7 cells. The binding affinity of ICZ is only a factor of 3.7 x 10(-2) lower than that of the highly toxic environmental contaminant and cancer promoter 2,3,7,8-tetrachlorodibenzo-p-dioxin. ICZ and related condensation products appear responsible for the enzyme-inducing effects of dietary I3C. C1 UNIV CALIF BERKELEY,LAWRENCE BERKELEY LAB,MELVIN CALVIN LAB,BERKELEY,CA 94720. NORTHWESTERN UNIV,DEPT PHARMACOL & TOXICOL,CHICAGO,IL 60611. RP BJELDANES, LF (reprint author), UNIV CALIF BERKELEY,DEPT NUTR SCI,BERKELEY,CA 94720, USA. NR 39 TC 390 Z9 390 U1 1 U2 10 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 NOV PY 1991 VL 88 IS 21 BP 9543 EP 9547 DI 10.1073/pnas.88.21.9543 PG 5 WC Multidisciplinary Sciences SC Science & Technology - Other Topics GA GM781 UT WOS:A1991GM78100035 PM 1658785 ER PT J AU MCCOMAS, DJ BARRACLOUGH, BL ELPHIC, RC FUNSTEN, HO THOMSEN, MF AF MCCOMAS, DJ BARRACLOUGH, BL ELPHIC, RC FUNSTEN, HO THOMSEN, MF TI MAGNETOSPHERIC IMAGING WITH LOW-ENERGY NEUTRAL ATOMS SO PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF THE UNITED STATES OF AMERICA LA English DT Article ID RING CURRENT; CARBON; STORM; IONS AB Global imaging of the magnetospheric charged particle population can be achieved by remote measurement of the neutral atoms produced when magnetospheric ions undergo charge exchange with cold exospheric neutral atoms. Previously suggested energetic neutral atom imagers were only able to measure neutral atoms with energies typically greater than several tens of keV. A laboratory prototype has been built and tested for a different type of space plasma neutral imaging instrument, which allows neutral atoms to be imaged down to < 1 keV. Such low-energy measurements provide greater sensitivity for imaging the terrestrial magnetosphere and allow the bulk of the magnetospheric ion distribution, typically centered below 10 keV, to be observed rather than just the high-energy tail of the distribution. The low-energy neutral atom measurements are made possible by utilizing charge state modifications that occur when an initially neutral atom passes through an ultrathin carbon foil. Oxygen, for example, is highly electronegative, and for energies of almost-equal-to 10-30 keV, the O- yield is almost-equal-to 30%, essentially independent of the charge state of the incident oxygen atom. These ions are energy per charge analyzed, and the UV background is rejected by using an electrostatic analyzer. Imaging of other ion species, such as hydrogen, could also be accomplished by using ultrathin foil-induced charge state modifications. The technique described in this paper provides a method for imaging charge exchange neutrals from the terrestrial magnetosphere and would also have applications for similar imaging in other planetary or cometary environs. The Inner Magnetosphere Imaging Mission, which the National Aeronautics and Space Administration is presently considering, would provide a nearly ideal platform for low-energy neutral atom imaging, and such measurements would substantially enhance the scientific yield of this mission. RP MCCOMAS, DJ (reprint author), UNIV CALIF LOS ALAMOS SCI LAB,SPACE PLASMA PHYS GRP,LOS ALAMOS,NM 87545, USA. RI Funsten, Herbert/A-5702-2015 OI Funsten, Herbert/0000-0002-6817-1039 NR 20 TC 28 Z9 28 U1 1 U2 3 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 NOV PY 1991 VL 88 IS 21 BP 9598 EP 9602 DI 10.1073/pnas.88.21.9598 PG 5 WC Multidisciplinary Sciences SC Science & Technology - Other Topics GA GM781 UT WOS:A1991GM78100046 PM 11607229 ER PT J AU SNYDER, SW RUSTANDI, RR BIGGINS, J NORRIS, JR THURNAUER, MC AF SNYDER, SW RUSTANDI, RR BIGGINS, J NORRIS, JR THURNAUER, MC TI DIRECT ASSIGNMENT OF VITAMIN-K1 AS THE SECONDARY ACCEPTOR-A1 IN PHOTOSYSTEM-I SO PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF THE UNITED STATES OF AMERICA LA English DT Article DE PHOTOSYNTHESIS; QUINONES; ELECTRON SPIN POLARIZATION ELECTRON PARAMAGNETIC RESONANCE; PHOTOSYSTEM-I REACTIONS ID ELECTRON-SPIN POLARIZATION; PHYLLOQUINONE; IDENTIFICATION; A1 AB The characteristic electron spin polarized electron paramagnetic resonance (ESP EPR) signal observed in photosystem I (PSI) has been previously assigned to a radical pair composed of the oxidized primary donor and a reduced vitamin K1. Under conditions in which Bottin, H. & Setif, P. [(1991), Biochim. Biophys. Acta 105, 331-3361 proposed that A1 is doubly reduced, the ESP EPR signal was not observed. Therefore, the ESP EPR signal can be directly attributed to A1-, and vitamin K1 can be assigned as this PSI acceptor. The ESP EPR signal was partially restored by removal of the chemical reductants. C1 ARGONNE NATL LAB,DIV CHEM,ARGONNE,IL 60439. UNIV CHICAGO,DEPT CHEM,CHICAGO,IL 60637. BROWN UNIV,BIOCHEM SECT,PROVIDENCE,RI 02912. RI Snyder, Seth/C-4370-2008 OI Snyder, Seth/0000-0001-6232-1668 NR 14 TC 48 Z9 49 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 NOV PY 1991 VL 88 IS 21 BP 9895 EP 9896 DI 10.1073/pnas.88.21.9895 PG 2 WC Multidisciplinary Sciences SC Science & Technology - Other Topics GA GM781 UT WOS:A1991GM78100109 PM 11607234 ER PT J AU CHENG, KC PRESTON, BD CAHILL, DS DOSANJH, MK SINGER, B LOEB, LA AF CHENG, KC PRESTON, BD CAHILL, DS DOSANJH, MK SINGER, B LOEB, LA TI THE VINYL-CHLORIDE DNA DERIVATIVE N2,3-ETHENOGUANINE PRODUCES G-]A TRANSITIONS IN ESCHERICHIA-COLI SO PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF THE UNITED STATES OF AMERICA LA English DT Article DE ENVIRONMENTAL CARCINOGENESIS; CHLORACETALDEHYDE; SITE-SPECIFIC MUTAGENESIS; CYCLIC DNA ADDUCTS; MUTAGENICITY TESTS ID SITE-SPECIFIC MUTAGENESIS; PHENOTYPIC SELECTION; HIGH FIDELITY; POLYMERASE; OLIGODEOXYNUCLEOTIDES; FLUORESCENCE; REPLICATION; ADDUCTS; LIVER AB Vinyl chloride is a known human and rodent carcinogen that forms several cyclic base derivatives in DNA. The mutagenic potential of these derivatives has been examined in vitro but not in vivo. One of these derivatives, N2,3-ethenoguanine (epsilon-G), is known to base pair with both cytosine and thymine during in vitro DNA synthesis, which would result in G --> A transitions. To determine the base pairing specificity of this labile guanine derivative in Escherichia coli, we have developed a genetic reversion assay for guanine derivatives. The assay utilizes DNA polymerase-mediated analogue insertion into a bacteriophage vector, M13G*1, which detects all single-base substitutions at position 141 of the lacz-alpha gene by change in plaque color. After the insertion of a single epsilon-G opposite the template cytosine at position 141 by use of epsilon-dGTP and DNA polymerase and further extension with all four normal dNTPs, the DNA was transfected into E. coli. Transfection of M13G*1 containing epsilon-G at the target site yielded 135 mutants among 26,500 plaques, 134 of which represented G --> A transitions. The uncorrected mutation frequency was 0.5 %, as compared with the control value, almost-equal-to 0.02%; when corrected for epsilon-G content and penetrance, the calculated mutagenic potential of epsilon-G (mutations/analogue) was about 13%. We thus conclude that epsilon-G specifically induces G --> A transitions during DNA replication in E. coli. The M13G*l assay may permit the testing of other labile guanine derivatives not otherwise amenable to mutagenesis studies. C1 UNIV WASHINGTON,DEPT PATHOL SM30,SEATTLE,WA 98195. RUTGERS STATE UNIV,COLL PHARM,CANC RES LAB,PISCATAWAY,NJ 08855. UNIV CALIF BERKELEY,LAWRENCE BERKELEY LAB,DIV CELL & MOLEC BIOL,DONNER LAB,BERKELEY,CA 94720. RI Cheng, Keith/B-6506-2011 FU NCI NIH HHS [CA47723, CA48174, R35-CA39903] NR 38 TC 147 Z9 150 U1 1 U2 5 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 NOV PY 1991 VL 88 IS 22 BP 9974 EP 9978 DI 10.1073/pnas.88.22.9974 PG 5 WC Multidisciplinary Sciences SC Science & Technology - Other Topics GA GP895 UT WOS:A1991GP89500014 PM 1946466 ER PT J AU CARNES, BA FRITZ, TE AF CARNES, BA FRITZ, TE TI RESPONSES OF THE BEAGLE TO PROTRACTED IRRADIATION .1. EFFECT OF TOTAL DOSE AND DOSE-RATE SO RADIATION RESEARCH LA English DT Article ID LIFE TABLE DATA; HOMOGENEITY ANALYSES; TREND; PROPORTIONS RP CARNES, BA (reprint author), ARGONNE NATL LAB,DIV BIOL & MED RES,ARGONNE,IL 60439, USA. FU NCI NIH HHS [Y01-CP-50503] NR 31 TC 14 Z9 15 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 NOV PY 1991 VL 128 IS 2 BP 125 EP 132 DI 10.2307/3578129 PG 8 WC Biology; Biophysics; Radiology, Nuclear Medicine & Medical Imaging SC Life Sciences & Biomedicine - Other Topics; Biophysics; Radiology, Nuclear Medicine & Medical Imaging GA GM764 UT WOS:A1991GM76400002 PM 1947009 ER PT J AU STRAUME, T MCDONALD, JC PEDERSON, RA BRENNER, DJ DOBSON, RL AF STRAUME, T MCDONALD, JC PEDERSON, RA BRENNER, DJ DOBSON, RL TI HIROSHIMA-LIKE NEUTRONS FROM A-BOMB REPLICA - PHYSICAL BASIS FOR THEIR USE IN BIOLOGICAL EXPERIMENTS SO RADIATION RESEARCH LA English DT Article ID CHROMOSOME-ABERRATIONS; HUMAN-LYMPHOCYTES; FISSION NEUTRONS; DEPENDENCE; INDUCTION; CF-252 C1 PACIFIC NW LAB, RICHLAND, WA 99352 USA. UNIV CALIF LOS ALAMOS SCI LAB, LOS ALAMOS, NM 87545 USA. COLUMBIA UNIV, NEW YORK, NY 10032 USA. RP STRAUME, T (reprint author), UNIV CALIF LAWRENCE LIVERMORE NATL LAB, LIVERMORE, CA 94550 USA. FU NCI NIH HHS [5 RO1 CA-34650, CA12536] NR 39 TC 9 Z9 9 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 NOV PY 1991 VL 128 IS 2 BP 133 EP 142 DI 10.2307/3578130 PG 10 WC Biology; Biophysics; Radiology, Nuclear Medicine & Medical Imaging SC Life Sciences & Biomedicine - Other Topics; Biophysics; Radiology, Nuclear Medicine & Medical Imaging GA GM764 UT WOS:A1991GM76400003 PM 1947010 ER PT J AU DOBSON, RL STRAUME, T CARRANO, AV MINKLER, JL DEAVEN, LL LITTLEFIELD, LG AWA, AA AF DOBSON, RL STRAUME, T CARRANO, AV MINKLER, JL DEAVEN, LL LITTLEFIELD, LG AWA, AA TI BIOLOGICAL EFFECTIVENESS OF NEUTRONS FROM HIROSHIMA BOMB REPLICA - RESULTS OF A COLLABORATIVE CYTOGENETIC STUDY SO RADIATION RESEARCH LA English DT Article ID HUMAN-LYMPHOCYTES; IRRADIATION; RADIATION C1 UNIV CALIF LAWRENCE LIVERMORE NATL LAB,LIVERMORE,CA 94550. UNIV CALIF LOS ALAMOS SCI LAB,LOS ALAMOS,NM 87545. OAK RIDGE ASSOCIATED UNIV,OAK RIDGE,TN 37831. RADIAT EFFECTS RES FDN,HIROSHIMA 730,JAPAN. NR 32 TC 25 Z9 25 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 NOV PY 1991 VL 128 IS 2 BP 143 EP 149 DI 10.2307/3578131 PG 7 WC Biology; Biophysics; Radiology, Nuclear Medicine & Medical Imaging SC Life Sciences & Biomedicine - Other Topics; Biophysics; Radiology, Nuclear Medicine & Medical Imaging GA GM764 UT WOS:A1991GM76400004 PM 1947011 ER PT J AU CODERRE, JA SLATKIN, DN MICCA, PL CIALLELLA, JR AF CODERRE, JA SLATKIN, DN MICCA, PL CIALLELLA, JR TI BORON NEUTRON-CAPTURE THERAPY OF A MURINE MELANOMA WITH PARA-BORONOPHENYLALANINE - DOSE-RESPONSE ANALYSIS USING A MORBIDITY INDEX SO RADIATION RESEARCH LA English DT Article ID GROWTH DELAY DATA; MICE; IRRADIATION; PARAMETERS; SYSTEM; BEAM RP CODERRE, JA (reprint author), BROOKHAVEN NATL LAB,DEPT MED,UPTON,NY 11973, USA. FU NCI NIH HHS [CA42446] NR 25 TC 27 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 NOV PY 1991 VL 128 IS 2 BP 177 EP 185 DI 10.2307/3578135 PG 9 WC Biology; Biophysics; Radiology, Nuclear Medicine & Medical Imaging SC Life Sciences & Biomedicine - Other Topics; Biophysics; Radiology, Nuclear Medicine & Medical Imaging GA GM764 UT WOS:A1991GM76400008 PM 1947013 ER PT J AU EISEN, Y HARVEY, WF RAJU, MR AF EISEN, Y HARVEY, WF RAJU, MR TI RADIOBIOLOGY OF ALPHA-PARTICLES .2. DOSIMETRY OF LOW-ENERGY ALPHA-PARTICLES USING PARALLEL-PLATE IONIZATION CHAMBERS AND A SURFACE-BARRIER DETECTOR SO RADIATION RESEARCH LA English DT Article C1 UNIV CALIF LOS ALAMOS SCI LAB,CELL BIOL GRP,LOS ALAMOS,NM 87545. RP EISEN, Y (reprint author), UNIV CALIF LOS ALAMOS SCI LAB,RADIAT PROTECT GRP,DOSE ASSESSMENT SECT,POB 1663,LOS ALAMOS,NM 87545, USA. NR 10 TC 7 Z9 7 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 NOV PY 1991 VL 128 IS 2 BP 197 EP 203 DI 10.2307/3578138 PG 7 WC Biology; Biophysics; Radiology, Nuclear Medicine & Medical Imaging SC Life Sciences & Biomedicine - Other Topics; Biophysics; Radiology, Nuclear Medicine & Medical Imaging GA GM764 UT WOS:A1991GM76400011 PM 1947016 ER PT J AU RAJU, MR EISEN, Y CARPENTER, S INKRET, WC AF RAJU, MR EISEN, Y CARPENTER, S INKRET, WC TI RADIOBIOLOGY OF ALPHA-PARTICLES .3. CELL INACTIVATION BY ALPHA-PARTICLE TRAVERSALS OF THE CELL-NUCLEUS SO RADIATION RESEARCH LA English DT Article ID ULTRASOFT X-RAYS; SURVIVAL; FIBROBLASTS C1 UNIV CALIF LOS ALAMOS SCI LAB,RADIAT PROTECT GRP,DOSE ASSESSMENT SECT,LOS ALAMOS,NM 87545. RP RAJU, MR (reprint author), UNIV CALIF LOS ALAMOS SCI LAB,CELLULAR & MOLEC BIOL GRP,POB 1663,LOS ALAMOS,NM 87545, USA. NR 16 TC 132 Z9 134 U1 0 U2 1 PU RADIATION RESEARCH SOC PI OAK BROOK PA 2021 SPRING RD, STE 600, OAK BROOK, IL 60521 SN 0033-7587 J9 RADIAT RES JI Radiat. Res. PD NOV PY 1991 VL 128 IS 2 BP 204 EP 209 DI 10.2307/3578139 PG 6 WC Biology; Biophysics; Radiology, Nuclear Medicine & Medical Imaging SC Life Sciences & Biomedicine - Other Topics; Biophysics; Radiology, Nuclear Medicine & Medical Imaging GA GM764 UT WOS:A1991GM76400012 PM 1947017 ER PT J AU GEANMARTON, AD KIRSCH, CFE VEZINA, LG WEBER, AL AF GEANMARTON, AD KIRSCH, CFE VEZINA, LG WEBER, AL TI FOCAL AMYLOIDOSIS OF THE HEAD AND NECK - EVALUATION WITH CT AND MR IMAGING SO RADIOLOGY LA English DT Article DE AMYLOIDOSIS; COMPUTED TOMOGRAPHY (CT), TISSUE CHARACTERIZATION; MAGNETIC RESONANCE (MR), TISSUE CHARACTERIZATION; NASOPHARYNX, ABNORMALITIES; NASOPHARYNX, CT STUDIES; NASOPHARYNX, MR STUDIES; ORBIT, ABNORMALITIES ID BETA-FIBRILLOSES; DEPOSITS AB Localized amyloidosis of the head and neck was found retrospectively in the nasopharynx (n = 3) and orbit (n = 1) of four female patients (mean age, 32 years), three of whom had a prior history of antigenic stimulation. In all patients, computed tomography revealed a slightly high absorption and a relatively homogeneous, partially calcified mass. In the one patient who underwent magnetic resonance (MR) imaging, a distinctive loss of signal intensity was seen on the long repetition time/echo time sequence. This enhanced T2 relaxation may be due to (a) static or slowly fluctuating internal magnetic fields arising from adjacent amyloid protons held in relatively fixed positions within the beta-pleated sheet, resulting in quick phase dispersion; (b) chemical exchange and spin-spin interaction with adjacent water protons; and (c) diffusion through differences in diamagnetic susceptibility. This unusual appearance at MR imaging may improve the ability of radiologists to distinguish focal amyloidosis from many other diseases that affect the head and neck. C1 UNIV NEW MEXICO,SCH MED,LOS ALAMOS NATL LAB,ALBUQUERQUE,NM 87131. CHILDRENS HOSP,NATL MED CTR,DEPT RADIOL,WASHINGTON,DC 20010. MASSACHUSETTS EYE & EAR HOSP,DEPT RADIOL,BOSTON,MA 02114. RP GEANMARTON, AD (reprint author), UNIV CALIF SAN FRANCISCO,SAN FRANCISCO GEN HOSP,DEPT RADIOL,1001 POTRERO AVE,SAN FRANCISCO,CA 94110, USA. NR 25 TC 77 Z9 77 U1 0 U2 3 PU RADIOLOGICAL SOC NORTH AMER PI EASTON PA 20TH AND NORTHAMPTON STS, EASTON, PA 18042 SN 0033-8419 J9 RADIOLOGY JI Radiology PD NOV PY 1991 VL 181 IS 2 BP 521 EP 525 PG 5 WC Radiology, Nuclear Medicine & Medical Imaging SC Radiology, Nuclear Medicine & Medical Imaging GA GL841 UT WOS:A1991GL84100036 PM 1924798 ER PT J AU HART, M SIDDONS, DP AMEMIYA, Y STOJANOFF, V AF HART, M SIDDONS, DP AMEMIYA, Y STOJANOFF, V TI TUNABLE X-RAY POLARIMETERS FOR SYNCHROTRON RADIATION SOURCES SO REVIEW OF SCIENTIFIC INSTRUMENTS LA English DT Article ID FORBIDDEN REFLECTIONS; SCATTERING; GERMANIUM; SILICON AB We describe the design and optical characteristics of a tunable x-ray polarimeter set up at the National Synchrotron Light Source at Brookhaven. Initially, the energy range from 7.0 to 9.2 keV is covered with a polarization extinction ratio greater than 10 000 and a statistically limited sensitivity of 70-mu-rad in measurements of optical rotary power. First spectroscopic measurements on a wide range of cobalt compounds show optical activity, Faraday rotation, and circular dichroism in the energy region close to the cobalt K edge. More recently we have worked on a variety of samples containing iron near the iron K edge. C1 BROOKHAVEN NATL LAB,UPTON,NY 11973. KEK NAT LAB HIGH ENERGY PHYS,PHOTON FACTORY,OHO,IBARAKI 305,JAPAN. RP HART, M (reprint author), UNIV MANCHESTER,DEPT PHYS,SCHUSTER LAB,MANCHESTER M13 9PL,LANCS,ENGLAND. RI stojanoff, vivian /I-7290-2012 OI stojanoff, vivian /0000-0002-6650-512X NR 28 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 0034-6748 J9 REV SCI INSTRUM JI Rev. Sci. Instrum. PD NOV PY 1991 VL 62 IS 11 BP 2540 EP 2544 DI 10.1063/1.1142523 PG 5 WC Instruments & Instrumentation; Physics, Applied SC Instruments & Instrumentation; Physics GA GN773 UT WOS:A1991GN77300003 ER PT J AU HILL, NC LIMBACH, PA SHOMO, RE MARSHALL, AG APPELHANS, AD DELMORE, JE AF HILL, NC LIMBACH, PA SHOMO, RE MARSHALL, AG APPELHANS, AD DELMORE, JE TI FAST NEUTRAL BEAM ION-SOURCE COUPLED TO A FOURIER-TRANSFORM ION-CYCLOTRON RESONANCE MASS-SPECTROMETER SO REVIEW OF SCIENTIFIC INSTRUMENTS LA English DT Article ID CF-252 PLASMA DESORPTION; ELECTROSPRAY IONIZATION; ICR SPECTROMETRY; SF6; TIME AB The coupling of an autoneutralizing SF6- fast ion-beam gun to a Fourier transform ion cyclotron resonance (FT/ICR) mass spectrometer is described. The fast neutral beam provides for secondary-ion-type FT/ICR mass analysis [e.g., production of abundant pseudomolecular (M + H)+ ions] of involatile samples without the need for external ion injection, since ions are formed at the entrance to the ICR ion trap. The design, construction, and testing of the hybrid instrument are described. The feasibility of the experiment (for both broadband and high-resolution FT/ICR positive-ion mass spectra) is demonstrated with tetra-butylammonium bromide and a Tylenol(R) sample. The ability to analyze high molecular weight polymers with high mass resolution is demonstrated for Teflon(R). All of the advantages of the fast neutral beam ion source previously demonstrated with quadrupole mass analysis are preserved, and the additional advantages of FT/ICR mass analysis (e.g., high mass resolving power, ion trapping) are retained. C1 OHIO STATE UNIV,DEPT BIOCHEM,COLUMBUS,OH 43210. EG&G IDAHO INC,IDAHO NATL ENGN LAB,IDAHO FALLS,ID 83415. RP HILL, NC (reprint author), OHIO STATE UNIV,DEPT CHEM,120 W 18TH AVE,COLUMBUS,OH 43210, USA. RI Limbach, Patrick/A-9188-2009 OI Limbach, Patrick/0000-0003-1526-4546 NR 47 TC 8 Z9 8 U1 0 U2 2 PU AMER INST PHYSICS PI WOODBURY PA CIRCULATION FULFILLMENT DIV, 500 SUNNYSIDE BLVD, WOODBURY, NY 11797-2999 SN 0034-6748 J9 REV SCI INSTRUM JI Rev. Sci. Instrum. PD NOV PY 1991 VL 62 IS 11 BP 2612 EP 2617 DI 10.1063/1.1142239 PG 6 WC Instruments & Instrumentation; Physics, Applied SC Instruments & Instrumentation; Physics GA GN773 UT WOS:A1991GN77300015 ER PT J AU LUPPOV, VG MERTIG, M ROSER, T VANGUILDER, BS VUARIDEL, B MELNIK, YM PRUDKOGLYAD, AF AF LUPPOV, VG MERTIG, M ROSER, T VANGUILDER, BS VUARIDEL, B MELNIK, YM PRUDKOGLYAD, AF TI CRYOPUMPING OF ATOMIC-HYDROGEN SO REVIEW OF SCIENTIFIC INSTRUMENTS LA English DT Article AB The pumping speed for the cryopumping of an atomic hydrogen beam was measured. Measurements were made for cryocondensation, cryosorption, and differential pumping. The pumping speed for atomic hydrogen was observed to be much smaller than the pumping speed for molecular hydrogen. It is believed that this is due to the energy released during the recombination of the atomic hydrogen. C1 UNIV MICHIGAN,RANDALL LAB PHYS,ANN ARBOR,MI 48109. PROTVINO HIGH ENERGY PHYS INST,PROTVINO 142284,USSR. TECH UNIV DRESDEN,SEKT PHYS,O-8027 DRESDEN,GERMANY. BROOKHAVEN NATL LAB,DEPT AGS,UPTON,NY 11973. UNIV GENEVA,DEPT PHYS NUCL & CORPUSCULAIRE,CH-1211 GENEVA 4,SWITZERLAND. RP LUPPOV, VG (reprint author), JOINT INST NUCL RES,HIGH ENERGIES LAB,POB 79,HEAD PO,MOSCOW,USSR. NR 5 TC 1 Z9 1 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 NOV PY 1991 VL 62 IS 11 BP 2738 EP 2741 DI 10.1063/1.1142207 PG 4 WC Instruments & Instrumentation; Physics, Applied SC Instruments & Instrumentation; Physics GA GN773 UT WOS:A1991GN77300036 ER PT J AU STEINKAMP, JA HABBERSETT, RC HIEBERT, RD AF STEINKAMP, JA HABBERSETT, RC HIEBERT, RD TI IMPROVED MULTILASER MULTIPARAMETER FLOW CYTOMETER FOR ANALYSIS AND SORTING OF CELLS AND PARTICLES SO REVIEW OF SCIENTIFIC INSTRUMENTS LA English DT Article ID HUMAN-DIPLOID FIBROBLASTS; AXIAL LIGHT LOSS; DUAL-LASER; ALVEOLAR MACROPHAGES; CHROMOSOME SORTER; PROTEIN-CONTENT; LACEL SYSTEM; FLUORESCENCE; DESIGN; DNA AB An improved multilaser instrument has been developed for quantitative analysis and separation of biological cells and particles. Argon ion, krypton ion, and dye lasers are employed as excitation sources to sequentially illuminate cells labeled with multiple fluorochromes as they pass through an improved flow chamber that incorporates an electronic cell-volume sensor and an optical measurement region. Detectors located on the axis of each excitation beam are used to measure axial light loss and forward light scatter. Multicolor fluorescence is measured using a five-channel detector located orthogonal to the laser beam(s)-cell stream intersection(s). Sequential measurements are made on a cell-by-cell basis to provide pulse height, area, and width signals that are made coincident in time by analog delay modules to increase data throughput. Analog electronics are used to compute real-time ratios, sums, and differences of signals. Up to eight signals are acquired and displayed as single-parameter frequency distribution histograms and bivariate diagrams using a microcomputer. Processed signals also activate cell sorting according to computer-controlled preselected parametric criteria. The unique measurement capabilities and other new features designed into this instrument represent marked technological improvements over our previous system. RP STEINKAMP, JA (reprint author), UNIV CALIF LOS ALAMOS SCI LAB,POB 1663,LOS ALAMOS,NM 87545, USA. NR 65 TC 30 Z9 30 U1 1 U2 3 PU AMER INST PHYSICS PI WOODBURY PA CIRCULATION FULFILLMENT DIV, 500 SUNNYSIDE BLVD, WOODBURY, NY 11797-2999 SN 0034-6748 J9 REV SCI INSTRUM JI Rev. Sci. Instrum. PD NOV PY 1991 VL 62 IS 11 BP 2751 EP 2764 DI 10.1063/1.1142210 PG 14 WC Instruments & Instrumentation; Physics, Applied SC Instruments & Instrumentation; Physics GA GN773 UT WOS:A1991GN77300039 ER PT J AU TSANG, CF AF TSANG, CF TI COUPLED HYDROMECHANICAL-THERMOCHEMICAL PROCESSES IN ROCK FRACTURES SO REVIEWS OF GEOPHYSICS LA English DT Review ID FLUID-FLOW; GEOTHERMAL-RESERVOIRS; SINGLE FRACTURE; CONFINING PRESSURE; SOLUTE TRANSPORT; CRACK-GROWTH; PERMEABILITY; MODEL; SIMULATION; DEFORMATION AB The behavior of rock fractures under various coupled processes is reviewed under seven broad categories: (1) hydromechanical processes, (2) thermohydrologic processes, (3) hydrochemical processes, (4) thermohydromechanical processes, (5) thermohydrochemical processes, (6) hydromechanical-chemical processes, and (7) thermomechanical-hydrochemical processes. The state-of-the-art and possible directions of further research in these coupled processes are discussed. Rock fracture behaviors considered include not only dilation, closure, shear, and joint propagation but also changes in flow permeability and chemical sorption and retardation capabilities. These properties are of critical concern in practical considerations of the rock mass as a medium to store and isolate chemical and radioactive wastes. Investigations of coupled processes in two-fracture systems and multifracture systems are identified as important areas for future research. The need to consider coupled processes in borehole testing procedures involving rock fractures is emphasized. RP TSANG, CF (reprint author), UNIV CALIF BERKELEY,LAWRENCE BERKELEY LAB,DIV EXPTL BIOL & GENET,BERKELEY,CA 94720, USA. NR 97 TC 54 Z9 62 U1 4 U2 10 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 SN 8755-1209 J9 REV GEOPHYS JI Rev. Geophys. PD NOV PY 1991 VL 29 IS 4 BP 537 EP 551 DI 10.1029/91RG01832 PG 15 WC Geochemistry & Geophysics SC Geochemistry & Geophysics GA GR588 UT WOS:A1991GR58800003 ER PT J AU GUTBROD, H STOCKER, H AF GUTBROD, H STOCKER, H TI THE NUCLEAR-EQUATION OF STATE SO SCIENTIFIC AMERICAN LA English DT Article C1 GESELL SCHWERIONENFORSCH GMBH,INST HEAVY ION RES,W-6100 DARMSTADT 11,GERMANY. UNIV FRANKFURT,PHYS,W-6000 FRANKFURT,GERMANY. UNIV CALIF BERKELEY,LAWRENCE BERKELEY LAB,BERKELEY,CA 94720. UNIV CALIF LAWRENCE LIVERMORE NATL LAB,LIVERMORE,CA 94550. BROOKHAVEN NATL LAB,UPTON,NY 11973. RP GUTBROD, H (reprint author), CERN,EUROPEAN LAB PARTICLE PHYS,CH-1211 GENEVA 23,SWITZERLAND. RI Stoecker, Horst/D-6173-2013 OI Stoecker, Horst/0000-0002-3282-3664 NR 3 TC 0 Z9 0 U1 0 U2 0 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 NOV PY 1991 VL 265 IS 5 BP 32 EP 39 PG 8 WC Multidisciplinary Sciences SC Science & Technology - Other Topics GA GP213 UT WOS:A1991GP21300009 ER PT J AU DURLU, N INAL, OT YOST, FG AF DURLU, N INAL, OT YOST, FG TI L12-TYPE TERNARY TITANIUM ALUMINIDES OF THE COMPOSITION TI25X8AL67 - TIAL3-BASED OR TIAL2-BASED SO SCRIPTA METALLURGICA ET MATERIALIA LA English DT Article ID STRUCTURAL L12 COMPOUNDS; PHASE-EQUILIBRIA; COMPRESSION BEHAVIOR; TI-FE; SYSTEM; ALLOYS; NI C1 SANDIA NATL LABS,ALBUQUERQUE,NM 87185. RP DURLU, N (reprint author), NEW MEXICO INST MIN & TECHNOL,DEPT MAT & MET ENGN,SOCORRO,NM 87801, USA. NR 30 TC 10 Z9 10 U1 1 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 NOV PY 1991 VL 25 IS 11 BP 2475 EP 2479 DI 10.1016/0956-716X(91)90052-3 PG 5 WC Materials Science, Multidisciplinary; Metallurgy & Metallurgical Engineering SC Materials Science; Metallurgy & Metallurgical Engineering GA GM988 UT WOS:A1991GM98800012 ER PT J AU NAJAFABADI, R WANG, HY SROLOVITZ, DJ LESAR, R AF NAJAFABADI, R WANG, HY SROLOVITZ, DJ LESAR, R TI THE EFFECTS OF SEGREGATION ON GRAIN-BOUNDARY COHESIVE ENERGIES IN NI3-XAL1+X SO SCRIPTA METALLURGICA ET MATERIALIA LA English DT Article ID NI3AL; BORON C1 UNIV CALIF LOS ALAMOS SCI LAB,DIV THEORET,LOS ALAMOS,NM 87545. RP NAJAFABADI, R (reprint author), UNIV MICHIGAN,DEPT MAT SCI & ENGN,ANN ARBOR,MI 48109, USA. RI LeSar, Richard/G-1609-2012 NR 22 TC 10 Z9 10 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 NOV PY 1991 VL 25 IS 11 BP 2497 EP 2502 DI 10.1016/0956-716X(91)90056-7 PG 6 WC Materials Science, Multidisciplinary; Metallurgy & Metallurgical Engineering SC Materials Science; Metallurgy & Metallurgical Engineering GA GM988 UT WOS:A1991GM98800016 ER PT J AU SRINIVASAN, S DESCH, PB SCHWARZ, RB AF SRINIVASAN, S DESCH, PB SCHWARZ, RB TI METASTABLE PHASES IN THE AL3X(X = TI, ZR, AND HF) INTERMETALLIC SYSTEM SO SCRIPTA METALLURGICA ET MATERIALIA LA English DT Article ID ALLOYS; STABILITY; DEFORMATION; AL3TI; ZRAL3; DO22 RP SRINIVASAN, S (reprint author), UNIV CALIF LOS ALAMOS SCI LAB,DEPT MAT SCI,LOS ALAMOS,NM 87545, USA. NR 26 TC 103 Z9 106 U1 0 U2 10 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 NOV PY 1991 VL 25 IS 11 BP 2513 EP 2516 DI 10.1016/0956-716X(91)90059-A PG 4 WC Materials Science, Multidisciplinary; Metallurgy & Metallurgical Engineering SC Materials Science; Metallurgy & Metallurgical Engineering GA GM988 UT WOS:A1991GM98800019 ER PT J AU SAIGAL, A KUPPERMAN, DS AF SAIGAL, A KUPPERMAN, DS TI RESIDUAL THERMAL STRAINS AND STRESSES IN NICKEL ALUMINIDE MATRIX COMPOSITES SO SCRIPTA METALLURGICA ET MATERIALIA LA English DT Article ID FIBER-REINFORCED GLASS C1 ARGONNE NATL LAB,DIV MAT & COMPONENTS TECHNOL,ARGONNE,IL 60439. RP SAIGAL, A (reprint author), TUFTS UNIV,DEPT MECH ENGN,MEDFORD,MA 02155, USA. NR 11 TC 6 Z9 6 U1 0 U2 0 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 NOV PY 1991 VL 25 IS 11 BP 2547 EP 2552 DI 10.1016/0956-716X(91)90066-A PG 6 WC Materials Science, Multidisciplinary; Metallurgy & Metallurgical Engineering SC Materials Science; Metallurgy & Metallurgical Engineering GA GM988 UT WOS:A1991GM98800026 ER PT J AU BREITBACH, KL CHUMBLEY, LS AF BREITBACH, KL CHUMBLEY, LS TI COMPARISON OF NANOCRYSTALLINE MATERIAL PRODUCED USING MECHANICAL MILLING AND A RF-PLASMA HEATING SOURCE SO SCRIPTA METALLURGICA ET MATERIALIA LA English DT Article RP BREITBACH, KL (reprint author), IOWA STATE UNIV SCI & TECHNOL,AMES LAB,AMES,IA 50011, USA. NR 10 TC 5 Z9 5 U1 0 U2 0 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD, ENGLAND OX5 1GB SN 0956-716X J9 SCRIPTA METALL MATER JI Scr. Metall. Materialia PD NOV PY 1991 VL 25 IS 11 BP 2553 EP 2558 DI 10.1016/0956-716X(91)90067-B PG 6 WC Materials Science, Multidisciplinary; Metallurgy & Metallurgical Engineering SC Materials Science; Metallurgy & Metallurgical Engineering GA GM988 UT WOS:A1991GM98800027 ER PT J AU BRICKELL, EF STINSON, DR AF BRICKELL, EF STINSON, DR TI THE DETECTION OF CHEATERS IN THRESHOLD SCHEMES SO SIAM JOURNAL ON DISCRETE MATHEMATICS LA English DT Article DE THRESHOLD SCHEME; SECRET SHARING SCHEME ID SECRET AB Informally, a (t, w)-threshold scheme is a way of distributing partial information (shadows) to w participants, so that any t of them can easily calculate a key (or secret), but no subset of fewer than t participants can determine the key. Presented in this paper is an unconditionally secure threshold scheme in which any cheating participant can be detected and identified with high probability by any honest participant, even if the cheater is in coalition with other participants. Also given is a construction that will detect with high probability a dealer who distributes inconsistent shadows (shares) to the honest participants. The scheme is not perfect; a set of t - 1 participants can rule out at most 1 + t-1w-t+1) possible keys, given the information they have. In this scheme, the key will be an element of GF(q) for some prime power q. Hence q can be chosen large enough so that the amount of information obtained by any t - 1 participants is negligible. C1 UNIV NEBRASKA,LINCOLN,NE 68588. RP BRICKELL, EF (reprint author), SANDIA NATL LABS,ALBUQUERQUE,NM 87185, USA. NR 12 TC 22 Z9 28 U1 0 U2 0 PU SIAM PUBLICATIONS PI PHILADELPHIA PA 3600 UNIV CITY SCIENCE CENTER PH#382-9800, PHILADELPHIA, PA 19104-2688 SN 0895-4801 J9 SIAM J DISCRETE MATH JI SIAM Discret. Math. PD NOV PY 1991 VL 4 IS 4 BP 502 EP 510 DI 10.1137/0404044 PG 9 WC Mathematics, Applied SC Mathematics GA GK992 UT WOS:A1991GK99200004 ER PT J AU Wright, SJ AF Wright, Stephen J. TI PARTITIONED DYNAMIC PROGRAMMING FOR OPTIMAL CONTROL SO SIAM JOURNAL ON OPTIMIZATION LA English DT Article DE discrete-time optimal control; parallel algorithms; dynamic programming; multiple shooting AB Parallel algorithms for the solution of linear-quadratic optimal control problems are described. The algorithms are based on a straightforward decomposition of the domain of the problem, and are related to multiple shooting methods for two-point boundary value problems. Their arithmetic cost is approximately twice that of the serial dynamic programming approach; however, they have the advantage that they can be efficiently implemented on a wide variety of parallel architectures. Extension to the case in which there are box constraints on the controls is simple. The algorithms can be used to solve linear-quadratic subproblems arising from the application of Newton's method or two-metric gradient projection methods to nonlinear problems. C1 Argonne Natl Lab, Argonne, IL 60439 USA. RP Wright, SJ (reprint author), Argonne Natl Lab, 9700 S Cass Ave, Argonne, IL 60439 USA. FU Applied Mathematical Sciences subprogram of the Office of Energy research, United States Department of Energy [W-31-109-Eng-38]; National Science Foundation [DMS-8900984] FX This research was supported by the Applied Mathematical Sciences subprogram of the Office of Energy research, United States Department of Energy, contract W-31-109-Eng-38, and by the National Science Foundation under contract DMS-8900984. NR 15 TC 6 Z9 6 U1 0 U2 0 PU SIAM PUBLICATIONS PI PHILADELPHIA PA 3600 UNIV CITY SCIENCE CENTER, PHILADELPHIA, PA 19104-2688 USA SN 1052-6234 EI 1095-7189 J9 SIAM J OPTIMIZ JI SIAM J. Optim. PD NOV PY 1991 VL 1 IS 4 BP 620 EP 642 DI 10.1137/0801037 PG 23 WC Mathematics, Applied SC Mathematics GA V40ST UT WOS:000209499000012 ER PT J AU BISCHOF, CH HANSEN, PC AF BISCHOF, CH HANSEN, PC TI STRUCTURE-PRESERVING AND RANK-REVEALING QR-FACTORIZATIONS SO SIAM JOURNAL ON SCIENTIFIC AND STATISTICAL COMPUTING LA English DT Article DE RANK-REVEALING QR-FACTORIZATION; RANK-DEFICIENT PROBLEMS; NUMERICAL RANK; INCREMENTAL CONDITION ESTIMATION; SPARSE MATRICES ID LEAST-SQUARES PROBLEMS; HOUSEHOLDER TRANSFORMATIONS; WY REPRESENTATION; SPARSE; MATRIX; DECOMPOSITION; PRODUCTS AB The rank-revealing QR-factorization (RRQR-factorization) is a special QR-factorization that is guaranteed to reveal the numerical rank of the matrix under consideration. This makes the RRQR-factorization a useful tool in the numerical treatment of many rank-deficient problems in numerical linear algebra. In this paper, a framework is presented for the efficient implementation of RRQR algorithms, in particular, for sparse matrices. A sparse RRQR-algorithm should seek to preserve the structure and sparsity of the matrix as much as possible while retaining the ability to capture safely the numerical rank. To this end, the paper proposes to compute an initial QR-factorization using a restricted pivoting strategy guarded by incremental condition estimation (ICE), and then applies the algorithm suggested by Chan and Foster to this QR-factorization. The column exchange strategy used in the initial QR factorization will exploit the fact that certain column exchanges do not change the sparsity structure, and compute a sparse QR-factorization that is a good approximation of the sought-after RRQR-factorization. Due to quantities produced by ICE, the Chan/Foster RRQR algorithm can be implemented very cheaply, thus verifying that the sought-after RRQR-factorization has indeed been computed. Experimental results on a model problem show that the initial QR-factorization is indeed very likely to produce RRQR-factorization. Fill-in is comparable with other methods, and little additional effort is required to implement the Chan/Foster postprocessing step. Compared to alternative strategies, the new algorithm allows to a greater extent the use of Householder transformations (instead of Givens rotations), and requires fewer touches of the data, while requiring not more (and sometimes substantially fewer) floating-point operations. These characteristics make the algorithm attractive for sparse problems, and a good candidate for parallel computers as well. C1 TECH UNIV DENMARK,DANISH COMP CTR RES & EDUC,DK-2800 LYNGBY,DENMARK. RP BISCHOF, CH (reprint author), ARGONNE NATL LAB,DIV MATH & COMP SCI,9700 S CASS AVE,ARGONNE,IL 60439, USA. RI Bischof, Christian/D-2897-2009 NR 37 TC 25 Z9 25 U1 0 U2 0 PU SIAM PUBLICATIONS PI PHILADELPHIA PA 3600 UNIV CITY SCIENCE CENTER PH#382-9800, PHILADELPHIA, PA 19104-2688 SN 0196-5204 J9 SIAM J SCI STAT COMP PD NOV PY 1991 VL 12 IS 6 BP 1332 EP 1350 DI 10.1137/0912073 PG 19 WC Mathematics, Applied SC Mathematics GA GK840 UT WOS:A1991GK84000007 ER PT J AU TONG, CH CHAN, TF KUO, CCJ AF TONG, CH CHAN, TF KUO, CCJ TI A DOMAIN DECOMPOSITION PRECONDITIONER BASED ON A CHANGE TO A MULTILEVEL NODAL BASIS SO SIAM JOURNAL ON SCIENTIFIC AND STATISTICAL COMPUTING LA English DT Note DE DOMAIN DECOMPOSITION; HIERARCHICAL BASIS; MULTILEVEL NODAL BASIS; PRECONDITIONED CONJUGATE GRADIENT METHODS; SCHUR COMPLEMENT ID HIERARCHICAL BASIS AB A domain decomposition method based on a simple change of basis on the interfaces and vertices is presented. It is shown that this leads to an effective preconditioner compared to the ones previously considered, such as the preconditioner by Bramble, Pasciak, and Schatz (BPS) [Math. Comp., 47 (1986), pp. 103-134], and the hierarchical basis domain decomposition (HBDD) preconditioner by Smith and Widlund [SIAM J. Sci. Statist. Comput., 11 (1990), pp. 1212-1226]. This domain-decomposed preconditioner is based on Bramble, Pasciak, and Xu's multilevel nodal basis preconditioner [Math. Comp., to appear]. It is shown that analytically this method and the HBDD method give the same order of condition number, namely, O(log2(H/h)) for problems with smooth coefficients. Numerically this method appears to be more effective with little additional cost and for the model Poisson problem, the condition numbers appear to be O(1). C1 UNIV CALIF LOS ANGELES,DEPT MATH,LOS ANGELES,CA 90024. UNIV SO CALIF,DEPT ELECT ENGN SYST,LOS ANGELES,CA 90089. RP TONG, CH (reprint author), SANDIA NATL LABS,LIVERMORE,CA 94551, USA. RI Kuo, C.-C. Jay/A-7110-2011; Chan, Tony/A-4166-2013 OI Kuo, C.-C. Jay/0000-0001-9474-5035; NR 11 TC 25 Z9 25 U1 0 U2 0 PU SIAM PUBLICATIONS PI PHILADELPHIA PA 3600 UNIV CITY SCIENCE CENTER PH#382-9800, PHILADELPHIA, PA 19104-2688 SN 0196-5204 J9 SIAM J SCI STAT COMP PD NOV PY 1991 VL 12 IS 6 BP 1486 EP 1495 DI 10.1137/0912082 PG 10 WC Mathematics, Applied SC Mathematics GA GK840 UT WOS:A1991GK84000016 ER PT J AU CARY, JW GEE, GW SIMMONS, CS AF CARY, JW GEE, GW SIMMONS, CS TI USING AN ELECTROOPTICAL SWITCH TO MEASURE SOIL-WATER SUCTION SO SOIL SCIENCE SOCIETY OF AMERICA JOURNAL LA English DT Note AB A simple and inexpensive electro-optical switch (infrared light-emitting diode; IR LED) was used to show that soil water suctions can be measured accurately by employing nylon filter disks with different pore sizes. Nylon filter disks that become translucent when water is absorbed were shown to open or close an electro-optical switch at specific soil water suctions associated with the air-entry suction of a disk, thereby demonstrating the principle of a digital tensiometer. Sensors constructed by inserting a nylon filter disk in a switch were shown to operate across a suction range of 0.004 to 2.4 MPa and were tested in a silt loam soil under drying and wetting conditions. The switch-sensor's performance was compared with a second type of sensor (CdS photoresistor with LED) made with a layered fritted-glass disk instead of nylon. This second sensor was able to continuously detect changes of water content from air dry to saturated. We concluded, however, that the first type of sensor was superior for precisely measuring soil water suction. RP SIMMONS, CS (reprint author), PACIFIC NW LAB, RICHLAND, WA 99352 USA. NR 7 TC 0 Z9 0 U1 0 U2 2 PU SOIL SCI SOC AMER PI MADISON PA 677 SOUTH SEGOE ROAD, MADISON, WI 53711 SN 0361-5995 J9 SOIL SCI SOC AM J JI Soil Sci. Soc. Am. J. PD NOV-DEC PY 1991 VL 55 IS 6 BP 1798 EP 1800 PG 3 WC Soil Science SC Agriculture GA HB462 UT WOS:A1991HB46200051 ER PT J AU NYHAN, JW DRENNON, BJ AF NYHAN, JW DRENNON, BJ TI TENSIOMETER DATA ACQUISITION-SYSTEM FOR HYDROLOGIC STUDIES REQUIRING HIGH TEMPORAL RESOLUTION - REPLY SO SOIL SCIENCE SOCIETY OF AMERICA JOURNAL LA English DT Letter RP NYHAN, JW (reprint author), UNIV CALIF LOS ALAMOS SCI LAB,ENVIRONM SCI GRP,LOS ALAMOS,NM 87544, USA. NR 5 TC 1 Z9 1 U1 0 U2 0 PU SOIL SCI SOC AMER PI MADISON PA 677 SOUTH SEGOE ROAD, MADISON, WI 53711 SN 0361-5995 J9 SOIL SCI SOC AM J JI Soil Sci. Soc. Am. J. PD NOV-DEC PY 1991 VL 55 IS 6 BP 1803 EP 1804 PG 2 WC Soil Science SC Agriculture GA HB462 UT WOS:A1991HB46200054 ER PT J AU KING, RJ AF KING, RJ TI SOLAR CARS RACE FOR THE FUTURE - RESULTS OF THE GM SUNRAYCE USA AND THE WORLD SOLAR CHALLENGE SO SOLAR CELLS LA English DT Article AB In July 1990, 32 North American university teams gathered in Orlando, FL to compete in GM Sunrayce USA, a 1650 mile transcontinental race of solar powered cars. Using only sunlight for power, the cars had to travel through eight states over eleven days before reaching the finish line in Detroit, MI. Created as a student competition to strengthen hands-on science and engineering skills, Sunrayce was a triumph of higher learning. Students were motivated to learn skills and excel at challenges they never thought possible. Their hard work, creativity and innovation surpassed everyone's expectations. What started out as a race of students ended as a race of scientists and engineers better prepared for their future. The prize for the three winners of Sunrayce was an all expenses paid trip to compete in the 1990 World Solar Challenge (WSC) in Australia. The WSC is a 1870 n-mile solar car race across the Australian outback. This year's event had 36 competitors from around the world, including eleven entries from Japan, eight from the U.S.A., and five from Europe. In total, 62 different solar racing teams competed in the two events in 1990. Both events are described in detail in this paper. Vehicle specifications, race results and day-by-day descriptions of how the race developed are provided. Technical details of the three winning teams in GM Sunrayce USA are given in individual design reports written by the teams and following this paper. Pictures and summaries of each Sunrayce vehicle are given in Appendix A, which follows the design reports. RP KING, RJ (reprint author), US DOE,DIV PHOTOVOLTAIC TECHNOL,WASHINGTON,DC 20585, USA. NR 0 TC 5 Z9 5 U1 1 U2 11 PU ELSEVIER SCIENCE SA LAUSANNE PI LAUSANNE 1 PA PO BOX 564, 1001 LAUSANNE 1, SWITZERLAND SN 0379-6787 J9 SOL CELLS PD NOV PY 1991 VL 31 IS 5 BP 395 EP 424 DI 10.1016/0379-6787(91)90011-D PG 30 WC Energy & Fuels SC Energy & Fuels GA GU312 UT WOS:A1991GU31200001 ER PT J AU AYDINLI, A COMPAAN, A CONTRERASPUENTE, G MASON, A AF AYDINLI, A COMPAAN, A CONTRERASPUENTE, G MASON, A TI POLYCRYSTALLINE CD1-XZNXTE THIN-FILMS ON GLASS BY PULSED LASER DEPOSITION SO SOLID STATE COMMUNICATIONS LA English DT Article ID MOLECULAR-BEAM EPITAXY; RAMAN-SCATTERING; TE AB Polycrystalline thin films of Cd1-xZn(x)Te on glass were grown by pulsed laser deposition using an XeCl excimer laser. X-ray diffraction, optical absorption, Raman scattering and energy dispersive x-ray analysis were used to characterize these films. The grains show a predominant <111> orientation with considerable amounts of <113> for the alloys. The band gap energy exhibits a small amount of bowing and the phonons display the expected two-mode behavior. Substrate temperatures above 275-degrees-C resulted in optical quality films with good stoichiometry for deposition rates below approximately 1 angstrom/pulse. C1 SOLAR ENERGY RES INST,PHOTOVOLTA MEASUREMENTS & PERFORMANCE BRANCH,GOLDEN,CO 80401. RP AYDINLI, A (reprint author), UNIV TOLEDO,DEPT PHYS & ASTRON,TOLEDO,OH 43606, USA. NR 17 TC 23 Z9 25 U1 1 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 NOV PY 1991 VL 80 IS 7 BP 465 EP 468 DI 10.1016/0038-1098(91)90051-V PG 4 WC Physics, Condensed Matter SC Physics GA GR863 UT WOS:A1991GR86300003 ER PT J AU WANG, CZ CHAN, CT HO, KM AF WANG, CZ CHAN, CT HO, KM TI OVERTONE PHONON STATES AND THE SHARP 2-PHONON RAMAN PEAK IN DIAMOND SO SOLID STATE COMMUNICATIONS LA English DT Article ID MOLECULAR-DYNAMICS; SPECTRUM; SILICON AB Phonon dispersions near the Brillouin zone center and the two-phonon overtone states at the high frequency region in diamond are studied with a tight-binding potential model previously developed. We found that the uppermost phonon branch has its minimum frequency at the zone center leading to a peak in the two-phonon overtone density-of-states at frequency bigger than twice of the one-phonon Raman frequency. The frequency shift and line shape of the two-phonon peak are compared with the experimental data. C1 IOWA STATE UNIV SCI & TECHNOL,MICROELECTR RES CTR,AMES,IA 50011. IOWA STATE UNIV SCI & TECHNOL,DEPT PHYS,AMES,IA 50011. RP WANG, CZ (reprint author), IOWA STATE UNIV SCI & TECHNOL,US DOE,AMES LAB,AMES,IA 50011, USA. NR 12 TC 0 Z9 0 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 NOV PY 1991 VL 80 IS 7 BP 469 EP 472 DI 10.1016/0038-1098(91)90052-W PG 4 WC Physics, Condensed Matter SC Physics GA GR863 UT WOS:A1991GR86300004 ER PT J AU DONGARRA, J DEMMEL, J AF DONGARRA, J DEMMEL, J TI LAPACK - A PORTABLE HIGH-PERFORMANCE NUMERICAL LIBRARY FOR LINEAR ALGEBRA SO SUPERCOMPUTER LA English DT Article; Proceedings Paper CT INTERNATIONAL SYMP ON SUPERCOMPUTING 91 CY NOV 06-08, 1991 CL UNIV KYUSHU, FUKUOKA, JAPAN HO UNIV KYUSHU AB High quality portable numerical libraries have existed for many years. These libraries, such as LINPACK and EISPACK, were designed to be accurate, robust, efficient and portable in a Fortran environment of conventional uniprocessors, diverse floating-point arithmetics, and limited input data structures. These libraries are no longer adequate on modern high-performance computer architectures. We describe their inadequacies and how we are addressing them in the LAPACK project, a library of numerical linear algebra routines designed to supplant LINPACK and EISPACK. We shall show how the new architectures lead to important changes in the goals as well as the methods of library design. C1 UNIV CALIF BERKELEY,DEPT MATH,BERKELEY,CA 94720. UNIV CALIF BERKELEY,DIV COMP SCI,BERKELEY,CA 94720. OAK RIDGE NATL LAB,OAK RIDGE,TN 37831. RP DONGARRA, J (reprint author), UNIV TENNESSEE,DEPT COMP SCI,KNOXVILLE,TN 37996, USA. RI Dongarra, Jack/E-3987-2014 NR 12 TC 5 Z9 5 U1 0 U2 1 PU ASFRA PI EDAM PA VOORHAVEN 33, 1135 BL EDAM, NETHERLANDS SN 0168-7875 J9 SUPERCOMPUTER JI Supercomputer PD NOV PY 1991 VL 8 IS 6 BP 33 EP 38 PG 6 WC Computer Science, Hardware & Architecture; Computer Science, Theory & Methods SC Computer Science GA HM360 UT WOS:A1991HM36000005 ER PT J AU PARKER, DH FISCHER, DA COLBERT, J KOEL, BE GLAND, JL AF PARKER, DH FISCHER, DA COLBERT, J KOEL, BE GLAND, JL TI HYDROGEN-INDUCED CO DISPLACEMENT FROM THE PT(111) SURFACE - AN ISOTHERMAL KINETIC-STUDY SO SURFACE SCIENCE LA English DT Article ID ADSORPTION; SPECTROSCOPY; PLATINUM; NI(100) AB Chemisorbed CO can be completely removed from the Pt(111) surface in the temperature range 318 to 348 K for hydrogen pressures above 2 x 10(-2) Torr. Thermal desorption of CO in this temperature range in the absence of hydrogen removes only a fraction of the adsorbed CO. A series of in situ isothermal kinetic experiments are presented in this paper which show that CO displacement in the presence of 0.2 Torr of hydrogen is a first-order process in CO coverage with an activation energy of 10.9 kcal/mol. We propose that the origin of this effect is that repulsive intereactions between coadsorbed atomic hydrogen and carbon monoxide induce high desorption rates of CO characteristic of high CO coverages, presumably due to lower values of the desorption activation energy. The importance of these results is to show that high coverages of coadsorbed hydrogen resulting from substantial overpressures of H-2 may substantially modify desorption activation energies, and thus the coverages and kinetic pathways available, even for strongly chemisorbed species. These phenomena may play an important role in surface reactions which occur at high pressure. C1 UNIV COLORADO,DEPT CHEM & BIOCHEM,BOULDER,CO 80309. UNIV COLORADO,COOPERAT INST RES ENVIRONM SCI,BOULDER,CO 80309. BROOKHAVEN NATL LAB,EXXON PRT,NSLS,UPTON,NY 11973. BROOKHAVEN NATL LAB,DIV INSTRUMENTAT,UPTON,NY 11973. UNIV MICHIGAN,DEPT CHEM,ANN ARBOR,MI 48109. RI Koel, Bruce/H-3857-2013 OI Koel, Bruce/0000-0002-0032-4991 NR 18 TC 31 Z9 31 U1 0 U2 2 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0039-6028 J9 SURF SCI JI Surf. Sci. PD NOV PY 1991 VL 258 IS 1-3 BP 75 EP 81 DI 10.1016/0039-6028(91)90902-5 PG 7 WC Chemistry, Physical; Physics, Condensed Matter SC Chemistry; Physics GA GQ633 UT WOS:A1991GQ63300016 ER PT J AU ALLENDORF, MD OUTKA, DA AF ALLENDORF, MD OUTKA, DA TI THE ADSORPTION OF H-ATOMS ON POLYCRYSTALLINE BETA-SILICON CARBIDE SO SURFACE SCIENCE LA English DT Article ID CHEMICAL VAPOR-DEPOSITION; ENERGY ELECTRON-DIFFRACTION; SINGLE-CRYSTAL; GROWTH-CHARACTERISTICS; HYDROGEN DESORPTION; THERMAL-DESORPTION; EPITAXIAL-GROWTH; SURFACE; SI(100); PHASE AB The adsorption of atomic hydrogen on a polycrystalline beta-silicon carbide (SiC) surface has been studied using temperature-programmed desorption (TPD). Atomic hydrogen adsorbs on this surface, whereas molecular hydrogen does not. Upon heating, the hydrogen recombines and desorbs as H-2, producing two peaks in the TPD spectrum at 975 and 1130 K. The unusually broad width of the desorption peaks is attributed to a distribution of surface binding energies for hydrogen atoms. The desorption spectra are fit using a model that assumes two adsorption sites and a Gaussian distribution of binding energies. The average activation energies derived for the two peaks are 63 and 72 kcal/mol. RP ALLENDORF, MD (reprint author), SANDIA NATL LABS,LIVERMORE,CA 94551, USA. NR 60 TC 32 Z9 32 U1 0 U2 2 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0039-6028 J9 SURF SCI JI Surf. Sci. PD NOV PY 1991 VL 258 IS 1-3 BP 177 EP 189 DI 10.1016/0039-6028(91)90912-C PG 13 WC Chemistry, Physical; Physics, Condensed Matter SC Chemistry; Physics GA GQ633 UT WOS:A1991GQ63300026 ER PT J AU CHEN, JS DEVINE, TM OGLETREE, DF SALMERON, M AF CHEN, JS DEVINE, TM OGLETREE, DF SALMERON, M TI INSITU ELECTROCHEMICAL SCANNING TUNNELING MICROSCOPY STUDY OF THE STRUCTURAL-CHANGES OF SILVER SURFACES FOLLOWING AN OXIDATION REDUCTION CYCLE IN 1M-KCL SO SURFACE SCIENCE LA English DT Article ID ENHANCED RAMAN-SCATTERING; 2ND-HARMONIC GENERATION; POTENTIOSTATIC CONTROL; ELECTROLYTE INTERFACE; STM TIPS; SERS; AG; SPECTROSCOPY; ROUGHNESS; PYRIDINE AB In situ electrochemical scanning tunneling microscopy (ESTM) was employed to observe the surface of silver immersed in 1M KCl before and after an oxidation-reduction cycle (ORC). The roughness created by ORC was found to relax quickly. During the first 2 min marked decreases in surface area occur that are accompanied by the disappearance of nanometer size features. The rate of change in surface area decreases significantly after this time. Further decreases in surface energy are brought about by the growth of crystal planes which become apparent during the first 3-5 min. Some of these planes appear to be low index planes {111}; these have the lowest surface energy. The results of the present study suggest that the time evolution of surface enhanced Raman scattering (SERS) following an ORC of silver can be contributed to by changes in atomic scale roughness (less-than-or-equal-to 30 angstrom) as well as submicroscopic roughness (approximately 500 angstrom). C1 UNIV CALIF BERKELEY,LAWRENCE BERKELEY LAB,CTR ADV MAT,DIV MAT SCI,BERKELEY,CA 94720. RP CHEN, JS (reprint author), UNIV CALIF BERKELEY,DEPT MAT SCI & MINERAL ENGN,BERKELEY,CA 94720, USA. RI Ogletree, D Frank/D-9833-2016 OI Ogletree, D Frank/0000-0002-8159-0182 NR 30 TC 40 Z9 42 U1 1 U2 6 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0039-6028 J9 SURF SCI JI Surf. Sci. PD NOV PY 1991 VL 258 IS 1-3 BP 346 EP 358 DI 10.1016/0039-6028(91)90929-M PG 13 WC Chemistry, Physical; Physics, Condensed Matter SC Chemistry; Physics GA GQ633 UT WOS:A1991GQ63300043 ER PT J AU KELLOGG, GL AF KELLOGG, GL TI FIELD-ION MICROSCOPE AND ATOM-PROBE ANALYSIS OF NI OVERLAYERS ON THIN-FILMS OF RH2O3 SO SURFACE SCIENCE LA English DT Article ID CLEAN RUTHENIUM SURFACES; OXIDE FORMATION; MASS-SPECTROSCOPY; INITIAL-STAGES; OXIDATION; REDUCTION; PLATINUM AB The structure and composition of Ni overlayers on thin films of Rh2O3 have been investigated with the techniques of field ion microscopy and atom-probe mass spectroscopy. The metal-oxide-metal structures were produced by thermal oxidation of Rh field emitters in 1 Torr O2 at 500 K and subsequent deposition of Ni at approximately 100 K. The as-deposited Ni films were found to have a fine-grained polycrystalline structure and the Ni-Rh2O3 interface was atomically sharp. A small amount of interdiffusion between the Ni and Rh2O3 oxide was detected upon annealing the structures to 300 K. Interdiffusion was extensive upon annealing to 500 K. RP KELLOGG, GL (reprint author), SANDIA NATL LABS,ALBUQUERQUE,NM 87185, USA. NR 19 TC 4 Z9 4 U1 1 U2 1 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0039-6028 J9 SURF SCI JI Surf. Sci. PD NOV PY 1991 VL 257 IS 1-3 BP 1 EP 8 DI 10.1016/0039-6028(91)90773-L PG 8 WC Chemistry, Physical; Physics, Condensed Matter SC Chemistry; Physics GA GP212 UT WOS:A1991GP21200010 ER PT J AU LEUNG, WY SCHMITZ, PJ KANG, HC THIEL, PA AF LEUNG, WY SCHMITZ, PJ KANG, HC THIEL, PA TI SURPRISING EFFECT OF DEPOSITION TEMPERATURE ON PT/PD(110) RECONSTRUCTION SO SURFACE SCIENCE LA English DT Article ID ENERGY ELECTRON-DIFFRACTION; PT(110)-(1X2) SURFACE; INTENSITY OSCILLATIONS; FILM GROWTH; LEED; 1X2; TRANSITION; STABILITY; PLANE AB Pt films deposited on Pd(110) can exhibit (1 x 2) and (1 x 3) superstructures when they are annealed above room temperature. At a coverage of 3 monolayers, the film "remembers" the conditions of its deposition below room temperature. When the film is deposited at temperatures below 200 K, annealing above room temperature produces a bright and stable (1 x 2). When the deposition temperature falls between 200 and 300 K, annealing above room temperature produces split spots whose splitting is a function of deposition temperature. When the film is deposited at 300 K, annealing produces a (1 x 3) pattern. The origin of this memory effect is not clear, but evidence is presented that it does not result from spurious adsorption of hydrogen. The (1 x 2) and (1 x 3) superstructures probably correspond to bulk-like, missing-row reconstructions. C1 IOWA STATE UNIV SCI & TECHNOL,AMES LAB,AMES,IA 50011. RP LEUNG, WY (reprint author), IOWA STATE UNIV SCI & TECHNOL,DEPT CHEM,AMES,IA 50011, USA. RI Kang, Hway Chuan/A-3401-2012 NR 38 TC 4 Z9 4 U1 0 U2 0 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0039-6028 J9 SURF SCI JI Surf. Sci. PD NOV PY 1991 VL 257 IS 1-3 BP 79 EP 85 DI 10.1016/0039-6028(91)90781-M PG 7 WC Chemistry, Physical; Physics, Condensed Matter SC Chemistry; Physics GA GP212 UT WOS:A1991GP21200018 ER PT J AU BANSE, BA CREIGHTON, JR AF BANSE, BA CREIGHTON, JR TI THE ADSORPTION AND REACTION OF TRIETHYLGALLIUM ON GAAS(100) SO SURFACE SCIENCE LA English DT Article ID THERMAL-DECOMPOSITION; GAAS 100; TRIMETHYLGALLIUM; DESORPTION; SURFACE; MOMBE AB The surface chemistry of triethylgallium (TEGa) on both Ga-rich and As-rich GaAs(100) was studied using Auger electron spectroscopy (AES), low energy electron diffraction (LEED), and temperature programmed desorption (TPD). TEGa desorbs molecularly from two states with peak temperatures of about 323 and 523 K after TEGa exposure at 123 K on the Ga-rich surface. These conclusions of molecular desorption are in contrast to previous work which has been interpreted in terms of both TEGa and diethylgallium (DEGa) desorption above 150 K. The major products of TEGa decomposition, in agreement with previous work, are ethylene, hydrogen, and a small amount of ethyl radical. The saturation coverage of ethylene molecules and hydrogen atoms was measured to be approximately 1 x 10(14) cm-2. The total ethyl radical yield is estimated to be 8% of the saturation ethylene coverage (approximately 9 x 10(12) molecules cm-2). On the As-rich surface, more TEGa desorption is observed in comparison to the Ga-rich conditions. The decomposition products are identical to those observed for the Ga-rich surface; however, the relative amounts of ethyl radicals to ethylene and hydrogen are significantly different. RP BANSE, BA (reprint author), SANDIA NATL LABS,DIV 1126,POB 5800,ALBUQUERQUE,NM 87185, USA. RI Schaff, William/B-5839-2009 NR 17 TC 44 Z9 44 U1 0 U2 4 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0039-6028 J9 SURF SCI JI Surf. Sci. PD NOV PY 1991 VL 257 IS 1-3 BP 221 EP 229 DI 10.1016/0039-6028(91)90794-S PG 9 WC Chemistry, Physical; Physics, Condensed Matter SC Chemistry; Physics GA GP212 UT WOS:A1991GP21200031 ER PT J AU MITSUDA, Y YAMADA, T CHUANG, TJ SEKI, H CHIN, RP HUANG, JY SHEN, YR AF MITSUDA, Y YAMADA, T CHUANG, TJ SEKI, H CHIN, RP HUANG, JY SHEN, YR TI INTERACTIONS OF DEUTERIUM AND HYDROCARBON SPECIES WITH THE DIAMOND C(111) SURFACE SO SURFACE SCIENCE LA English DT Letter ID ELECTRON-SPECTROSCOPY; CARBON-FILMS; CHAIN MODEL; GROWTH; HYDROGEN; RECONSTRUCTION; METHYL; ADSORPTION; MECHANISM; ACETYLENE AB AES, XPS, TDS and LEED have been used to study the adsorption, the desorption and the reaction behavior of D atoms and CH(x) (1 less-than-or-equal-to x less-than-or-equal-to 3) species on the diamond C(111) surface. It is found that a small amount of chemisorbed D atoms can induce the (2 x 1) to (1 x 1) phase transition and hold the sp3 structure up to nearly 1400 K. The structural transformation can also be monitored by the optical second-harmonic generation technique. Thermal desorption of deuterium occurs mainly around 1300 K. Adsorption of CH(x) can also induce the phase change but not as readily as the D atoms. Annealing of the adlayer at a high temperature results in the partial conversion to graphitic carbon. D atoms can react with both the adsorbed CH(x) and the surface graphite. The surface bonding characteristics and the relevance of present results to the diamond CVD process are briefly discussed. C1 IBM CORP,DIV RES,ALMADEN RES CTR,SAN JOSE,CA 95120. UNIV CALIF BERKELEY,DEPT PHYS,BERKELEY,CA 94720. UNIV CALIF BERKELEY,LAWRENCE BERKELEY LAB,DIV MAT SCI,BERKELEY,CA 94720. NR 43 TC 63 Z9 63 U1 2 U2 9 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0039-6028 J9 SURF SCI JI Surf. Sci. PD NOV PY 1991 VL 257 IS 1-3 BP L633 EP L641 PG 9 WC Chemistry, Physical; Physics, Condensed Matter SC Chemistry; Physics GA GP212 UT WOS:A1991GP21200004 ER PT J AU LOGAN, J DEWEY, SL WOLF, AP FOWLER, JS BRODIE, JD ANGRIST, B VOLKOW, ND GATLEY, SJ AF LOGAN, J DEWEY, SL WOLF, AP FOWLER, JS BRODIE, JD ANGRIST, B VOLKOW, ND GATLEY, SJ TI EFFECTS OF ENDOGENOUS DOPAMINE ON MEASURES OF [F-18] N-METHYLSPIROPERIDOL BINDING IN THE BASAL GANGLIA - COMPARISON OF SIMULATIONS AND EXPERIMENTAL RESULTS FROM PET STUDIES IN BABOONS SO SYNAPSE LA English DT Article DE POSITRON EMISSION TOMOGRAPHY; AMPHETAMINE; KINETIC MODELING; DOPAMINE; RECEPTOR ID POSITRON EMISSION TOMOGRAPHY; BRAIN TRANSFER CONSTANTS; LIVING HUMAN-BRAIN; TIME UPTAKE DATA; INTRACEREBRAL DIALYSIS; INVIVO MICRODIALYSIS; GRAPHICAL EVALUATION; STRIATAL DOPAMINE; RECEPTOR DENSITY; H-3 RACLOPRIDE AB The effect of endogenous dopamine on PET measures of radioligand binding is important to the measurement of receptor density (or availability) and neurotransmitter interactions in vivo. We recently reported that pretreatment with amphetamine, a drug which stimulates dopamine release, significantly reduced NMS binding in the baboon brain as determined by the product lambda-k3 derived from the graphical analysis method for irreversible systems (lambda is the ratio of the forward to reverse plasma to tissue transport constants and k3 is proportional to receptor density) (Dewey et al.: Synapse 7:324-327, 1991). The purpose of this work is twofold: to evaluate the sensitivity and stability of the analysis method used for the NMS data and from simulation studies which include the competitive effects of dopamine on NMS binding to predict the effect of dopamine on the in vivo PET experiment. Using a measured plasma [F-18]-NMS input function from a control study in a baboon, simulation data was numerically generated explicitly allowing competition between NMS and dopamine in the calculation. This data was analyzed using the same techniques as used for the experimental data and the results were compared to in vitro calculations. The following conclusions were reached: 1) The effect of dopamine on specific binding was found to be greater in vivo than in vitro because the in vitro equilibrium experiment is controlled only by the relative Kd's of tracer and dopamine while the in vivo experiment also depends upon the halftime of tracer in tissue which is controlled by the tissue-to-plasma transport constant; 2) Experimental evidence from rodent studies (Seeman et al.: Synapse 3:96-97, 1989) and the agreement between PET studies (Wong et al.: Science 234:1558-1563, 1986a) and postmortem human studies (Seeman et al.: Science 225:728-731, 1984) in schizophrenics suggest that NMS is not likely to be affected by normal levels of endogenous dopamine. From the calculations reported here the effective in vivo Kd of dopamine for the NMS binding site would have to be on the order of or greater than 100 nM, assuming a synaptic dopamine concentration of 20 nM, in order that this concentration of dopamine have little effect on NMS binding. C1 VET ADM MED CTR,DEPT PSYCHIAT,NEW YORK,NY 10010. NYU MED CTR,DEPT PSYCHIAT,NEW YORK,NY 10016. BROOKHAVEN NATL LAB,DEPT MED,UPTON,NY 11973. RP LOGAN, J (reprint author), BROOKHAVEN NATL LAB,DEPT CHEM,UPTON,NY 11973, USA. FU NINDS NIH HHS [NS 15638] NR 43 TC 92 Z9 92 U1 1 U2 5 PU WILEY-LISS PI NEW YORK PA DIV JOHN WILEY & SONS INC 605 THIRD AVE, NEW YORK, NY 10158-0012 SN 0887-4476 J9 SYNAPSE JI Synapse PD NOV PY 1991 VL 9 IS 3 BP 195 EP 207 DI 10.1002/syn.890090306 PG 13 WC Neurosciences SC Neurosciences & Neurology GA GM944 UT WOS:A1991GM94400005 PM 1685599 ER PT J AU THOMAS, EV AF THOMAS, EV TI ERRORS-IN-VARIABLES ESTIMATION IN MULTIVARIATE CALIBRATION SO TECHNOMETRICS LA English DT Article DE CHEMOMETRICS; INFRARED SPECTROSCOPY; LINEAR FUNCTIONAL MODEL; MAXIMUM LIKELIHOOD ESTIMATION ID LEAST-SQUARES METHODS; CONFIDENCE AB A set of q responses, y = (y1, y2,..., y(q))T, is related to a set of p explanatory variables, x = (x1, x2, . . . , x(p))T, through the classical linear regression model, y(T) = a(T) + x(T)B + e(T). First, the unknown parameters a and B are estimated using a calibration set. The statistical problem that is considered here is that of estimating the vector x(o) that underlies a new observed vector of responses y(o) using the parameter estimates obtained from the first procedure. These two procedures are commonly referred to as calibration and prediction (or inverse prediction) and sometimes jointly referred to as calibration. The prediction procedure can be viewed as parameter estimation in errors-in-variables regression. The maximum likelihood estimator (assuming normally distributed measurement errors) is proposed for the prediction procedure. Unlike the classical estimator used in the prediction procedure, the proposed estimator is consistent with respect to the number of response variables. The performances of the maximum likelihood estimator and the classical estimator are compared both analytically and via Monte Carlo simulations. An example is given from infrared spectroscopy. RP THOMAS, EV (reprint author), SANDIA NATL LABS,ALBUQUERQUE,NM 87185, USA. NR 20 TC 13 Z9 13 U1 1 U2 5 PU AMER STATIST ASSN PI ALEXANDRIA PA 1429 DUKE ST, ALEXANDRIA, VA 22314 SN 0040-1706 J9 TECHNOMETRICS JI Technometrics PD NOV PY 1991 VL 33 IS 4 BP 405 EP 413 DI 10.2307/1269413 PG 9 WC Statistics & Probability SC Mathematics GA GK783 UT WOS:A1991GK78300003 ER PT J AU HU, PS WRIGHT, T MIAOU, SP GORMAN, R DAVIS, SC AF HU, PS WRIGHT, T MIAOU, SP GORMAN, R DAVIS, SC TI A STUDY OF INTERSTATE MOTOR CARRIER VEHICLE MILES OF TRAVEL SO TRANSPORTATION RESEARCH PART A-POLICY AND PRACTICE LA English DT Article AB This article summarizes the evaluation results of six data sources in terms of their ability to estimate the number of commercial trucks operating in interstate commerce and their vehicle miles of travel by carrier type and by state. The six data sources were: (a) Truck Inventory and Use Survey of the U.S. Bureau of the Census; (b) Nationwide Truck Activity and Commodity Survey of the U.S. Bureau of the Census; (c) National Truck Trip Information Survey of the University of Michigan Transportation Research Institute; (d) Highway Performance Monitoring System of the Federal Highway Administration, U.S. Department of Transportation; (e) International Registration Plan of the American Association of Motor Vehicle Administrators; and (f) State fuel tax reports from each individual state and the International Fuel Tax Agreement. Evaluation results concluded that none of the data sources by themselves were capable of providing reliable estimates at the state level. Although several attempts were made to combine the strengths of different data sources so that reliable estimates could be generated, none of them were successful. Data inconsistency and incompatibility contributed primarily to the failures. Although several of the six data sources by themselves could provide estimates at the national level, each had limitations. As a result of these findings, two cost-effective methodologies were proposed to estimate the number of commercial trucks operating in interstate commerce and their vehicle miles of travel by carrier type. Neither method required collecting additional data. C1 OAK RIDGE NATL LAB,MATH SCI SECT,OAK RIDGE,TN 37831. UNIV TENNESSEE,KNOXVILLE,TN 37996. FED HIGHWAY ADM,WASHINGTON,DC 20590. RP HU, PS (reprint author), OAK RIDGE NATL LAB,CTR TRANSPORTAT ANAL,OAK RIDGE,TN 37831, USA. NR 11 TC 0 Z9 0 U1 1 U2 2 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD, ENGLAND OX5 1GB SN 0965-8564 J9 TRANSPORT RES A-POL JI Transp. Res. Pt. A-Policy Pract. PD NOV PY 1991 VL 25 IS 6 BP 451 EP 463 DI 10.1016/0191-2607(91)90022-I PG 13 WC Economics; Transportation; Transportation Science & Technology SC Business & Economics; Transportation GA GU653 UT WOS:A1991GU65300012 ER PT J AU ALLEN, CW SMITH, DA AF ALLEN, CW SMITH, DA TI INSITU STUDY OF EFFECTS OF ION IRRADIATION ON SOLID-STATE CRYSTALLIZATION OF COBALT DISILICIDE THIN-FILMS SO ULTRAMICROSCOPY LA English DT Article; Proceedings Paper CT 2ND OSAKA INTERNATIONAL SYMP ON HIGH-VOLTAGE ELECTRON MICROSCOPY : NEW DIRECTIONS AND FUTURE ASPECTS OF HIGH VOLTAGE ELECTRON MICROSCOPY CY NOV 08-10, 1990 CL OSAKA UNIV, OSAKA, JAPAN SP MINIST EDUC SCI & CULTURE JAPAN HO OSAKA UNIV ID SILICON AB Results of a continuing in situ study of the ion-irradiation-modified crystallization of amorphous CoSi2 thin films are discussed. 1.5 MeV Kr ion irradiation is employed at 90 K to "mix" nominally amorphous, as-deposited material for subsequent epitaxial regrowth at 450 K. The ion irradiation is also employed at 300 K to produce ion-assisted crystallization. The average degree of transformation per ion is approximately 4 x 10(-20) cm3. The resultant number density of crystals, however, depends sensitively on prior treatment of the film. For example, 300 kV electron irradiation at 300 K prior to ion irradiation may result in a large number density of crystal nuclei. Low-dose Kr irradiation at 300 K may also cause a slight increase in the number density of crystals formed subsequently at 450 K, while larger Kr doses at 300 K (> 3 x 10(14) cm-2) may double the subsequent thermal growth rate at 450 K. These results are discussed qualitatively in terms of nucleation and growth theory. C1 IBM CORP,THOMAS J WATSON RES CTR,YORKTOWN HTS,NY 10598. RP ALLEN, CW (reprint author), ARGONNE NATL LAB,DIV MAT SCI,ARGONNE,IL 60439, USA. NR 8 TC 2 Z9 2 U1 0 U2 1 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0304-3991 J9 ULTRAMICROSCOPY JI Ultramicroscopy PD NOV PY 1991 VL 39 IS 1-4 BP 222 EP 230 DI 10.1016/0304-3991(91)90201-G PG 9 WC Microscopy SC Microscopy GA GY231 UT WOS:A1991GY23100027 ER PT J AU WANG, ZL BENTLEY, J AF WANG, ZL BENTLEY, J TI THEORY OF PHASE CORRELATIONS IN LOCALIZED INELASTIC ELECTRON-DIFFRACTION AND IMAGING SO ULTRAMICROSCOPY LA English DT Article ID DIFFUSE-SCATTERING; KIKUCHI PATTERNS; CRYSTALS; STEM; MICROSCOPE; IMAGES AB A dynamical theory is proposed starting from the coupled wave equations for describing inelastic electron scattering in perfect crystals and crystals with defects. The phase correlations of the localized inelastic scattering occurring at different atomic sites can be statistically evaluated before any numerical calculations, essentially providing an easy way for treating coherence, incoherence or partial coherence in dynamical electron diffraction. The time average of electron diffraction from the lattices of different thermal vibration configurations can be performed in just a single calculation. It is shown that the phase correlations of atomic vibrations result in streaking of electron diffraction spots. The possible streaks in 2D reciprocal space tau can be predicted by examining SIGMA-l-SIGMA-l1 cos[tau.(R(l) - R(l1))] for a monatomic system, where R(l) and R(l1) are the 3D positions of the lth atom within the unit cell and its first nearest neighbors located in the same atomic plane perpendicular to the incidence beam direction, respectively. The TDS streaks are located on lines satisfying tau.(R(l) - R(l1)) = 0. This rule can also be applied to multiatomic cases if the differences made by atomic structure factors are considered. Also this rule should allow the determination of strong atomic interaction relationships from the orientation of TDS in diffraction patterns. A dynamical diffraction theory is described to calculate the intensities of thermal diffuse scattering (TDS) streaks. Theoretical schemes are described for calculating electron energy-filtered images and diffraction patterns after exciting an atomic inner-shell, and Z-contrast images in scanning transmission electron microscopy (STEM). Some experimental evidence is shown to demonstrate spot streaking in electron diffraction and the corresponding theoretical interpretations. 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 48 TC 13 Z9 13 U1 0 U2 4 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0304-3991 J9 ULTRAMICROSCOPY JI Ultramicroscopy PD NOV PY 1991 VL 38 IS 2 BP 181 EP 213 DI 10.1016/0304-3991(91)90119-Q PG 33 WC Microscopy SC Microscopy GA GT320 UT WOS:A1991GT32000008 ER PT J AU HLOHOWSKYJ, I CHAGNON, N AF HLOHOWSKYJ, I CHAGNON, N TI REDUCTION IN TOLERANCE TO PROGRESSIVE HYPOXIA IN THE CENTRAL STONEROLLER MINNOW FOLLOWING SUBLETHAL EXPOSURE TO PHENOL SO WATER AIR AND SOIL POLLUTION LA English DT Article ID ACUTE TOXICITY; FATHEAD MINNOWS; RAINBOW AB Acute exposure of the central stoneroller minnow to sublethal levels of phenol was found to decrease the ability of this species to tolerate hypoxic conditions as indicated by the dissolved oxygen (DO) concentration at which loss of equilibrium occurred. For fishes acclimated at 7.5-degrees-C, loss of equilibrium occurred at progressively higher DO levels as the phenol exposure concentration was increased from 0 to 12 mg phenol L-1. Mean DO concentrations at which loss of equilibrium occurred ranged from 2.33 +/- 0.10 mg O2 L-1 for the control group (0 mg phenol L-1) to 2.76 +/- 0.14 mg O2 L-1 (at 12 mg phenol L-1). Loss of equilibrium also occurred at progressively higher DO levels in fish acclimated at 23-degrees-C, but only after an initial decrease among the 6 mg phenol L-1 test fish in the loss of equilibrium DO concentration. At 23-degrees-C, loss of equilibrium occurred at DO levels ranging from 1.3 +/- 0.09 mg O2 L-1 (6 mg phenol L-1) to 2.33 +/- 0.16 Mg O2 L-1 (12 mg phenol L-1). These data indicate that acute exposures to sublethal levels of phenol can have significant effects on the ability of the stoneroller minnow to tolerate conditions of low DO, and the results agree with the previously reported relationship between phenol toxicity and DO levels. C1 OHIO EDISON PROGRAM,COLUMBUS,OH 43266. RP HLOHOWSKYJ, I (reprint author), ARGONNE NATL LAB,ECOL SCI SECT,ARGONNE,IL 60439, USA. NR 26 TC 3 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 NOV PY 1991 VL 60 IS 1-2 BP 189 EP 196 DI 10.1007/BF00293974 PG 8 WC Environmental Sciences; Meteorology & Atmospheric Sciences; Water Resources SC Environmental Sciences & Ecology; Meteorology & Atmospheric Sciences; Water Resources GA HB308 UT WOS:A1991HB30800014 ER PT J AU HOOVER, KA FOLEY, MG HEASLER, PG BOYER, EW AF HOOVER, KA FOLEY, MG HEASLER, PG BOYER, EW TI SUB-GRID-SCALE CHARACTERIZATION OF CHANNEL LENGTHS FOR USE IN CATCHMENT MODELING SO WATER RESOURCES RESEARCH LA English DT Article ID NETWORKS AB We explored methods for extrapolating mainstream channel lengths of first-order drainage basins from synoptic data to characterize them for numerical watershed modeling. We analyzed four catchments in a climatologically semiarid and geologically homogeneous region east of the Cascade Mountains in Washington state. Within each of these catchments, we identified stream channel networks manually from 1:24,000-scale topographic maps, and from 50-m resolution digital elevation models using commercially available drainage network extraction methods. A least squares fit of logarithms of mainstream length plotted against basin area established a regression relation to use for predicting mainstream lengths in the smallest subbasins. To test our relation, we compared predicted mainstream lengths with first-, second- and third-order channel lengths measured from low-altitude aerial photographs of a representative fourth-order basin. Our results indicate that relations of mainstream length to basin area derived from coarsely gridded data (e.g., 30 m) cannot be used to characterize stream and basin morphometry in the smallest basins due to the presence of hydrologic and geometric controls (i.e., thresholds) that limit the mainstream channel length and total basin length in first-, second-, and third-order basins. The presence of these thresholds potentially constrains the range over which theoretically self-similar, or fractal, relationships can be applied to stream-channel networks. C1 UNIV VIRGINIA, DEPT ENVIRONM SCI, CHARLOTTESVILLE, VA 22903 USA. RP HOOVER, KA (reprint author), PACIFIC NW LAB, DEPT GEOSCI, BATTELLE BLVD,POB 999, RICHLAND, WA 99352 USA. RI Boyer, Elizabeth/D-6617-2013 NR 17 TC 3 Z9 3 U1 1 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 NOV PY 1991 VL 27 IS 11 BP 2865 EP 2873 DI 10.1029/91WR01551 PG 9 WC Environmental Sciences; Limnology; Water Resources SC Environmental Sciences & Ecology; Marine & Freshwater Biology; Water Resources GA GN682 UT WOS:A1991GN68200007 ER PT J AU BIDAUX, P TSANG, CF AF BIDAUX, P TSANG, CF TI FLUID-FLOW PATTERNS AROUND A WELL BORE OR AN UNDERGROUND DRIFT WITH COMPLEX SKIN EFFECTS SO WATER RESOURCES RESEARCH LA English DT Article AB A semianalytic solution is given for steady state flow around a well bore or a drift with a complex skin. The hydraulic conductivity of the skin may vary continuously as a function of the radial distance from the well (or drift) and may also be radially anisotropic. Such configurations can be found around damaged or acidized well bores or around a drift near which the stress redistribution induces changes in hydraulic conductivity. Purely radial flow, regional flow around an open or cemented hole without pumping or injection, and combined regional and radial flow are considered. Variations of hydraulic potential and Darcy velocity in various radial directions are studied for several cases and are found to be strongly affected by a complex skin. It is shown that the convergence of the streamlines toward the borehole, which is used in applications involving the point dilution method of measuring regional flow velocity, is significantly enhanced by a complex negative skin. Negative skin values may also reduce the size of the capture zone of a withdrawal well. Head distribution and tracer transport in combined radial and regional flow around a drift have also been modeled. It is demonstrated that tracer breakthrough curves from an experiment of tracer transport from an injection zone in the rock to the drift can be significantly affected by the fluid flow pattern around the drift, so the commonly used radial pattern may lead to erroneous results for tracer dispersivity. C1 UNIV SCI & TECH,HYDROGEOL LAB,CNRS,F-34095 MONTPELLIER 5,FRANCE. RP BIDAUX, P (reprint author), UNIV CALIF BERKELEY,LAWRENCE BERKELEY LAB,DIV EARTH SCI,BERKELEY,CA 94720, USA. NR 18 TC 22 Z9 22 U1 2 U2 6 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 SN 0043-1397 J9 WATER RESOUR RES JI Water Resour. Res. PD NOV PY 1991 VL 27 IS 11 BP 2993 EP 3008 DI 10.1029/91WR01947 PG 16 WC Environmental Sciences; Limnology; Water Resources SC Environmental Sciences & Ecology; Marine & Freshwater Biology; Water Resources GA GN682 UT WOS:A1991GN68200016 ER PT J AU FUERSCHBACH, PW KNOROVSKY, GA AF FUERSCHBACH, PW KNOROVSKY, GA TI A STUDY OF MELTING EFFICIENCY IN PLASMA-ARC AND GAS TUNGSTEN ARC-WELDING SO WELDING JOURNAL LA English DT Article DE PLASMA ARC WELDING; GTAW; MELTING EFFICIENCY; HEAT INPUT; WELD SCHEDULE; MEASUREMENT; ARC EFFICIENCY; PENETRATION; CALORIMETER AB Extensive calorimetric measurements of the net heat input for the plasma arc and the gas tungsten arc welding processes in an edge weld configuration have been conducted. The experiment compared base materials with contrasting thermal diffusivities and varied the weld process control parameters, including current pulsation, in order to determine their effects on both arc and melting efficiency. The arc efficiency for plasma arc welding was found to be lower and more variable than for gas tungsten arc welding due to the constricting torch nozzle. The melting efficiencies for the two processes were equivalent and increased with travel speed while asymptotically reaching a maximum level. At travel speeds below this level, current pulsation was found effective in increasing the melting efficiency for both processes. For many conditions, the plasma arc welding process outperformed the gas tungsten arc welding process by achieving deeper penetration for equivalent amounts of heat input. A dimensionless parameter was determined that correlates well with the measured melting efficiencies. It was used to express all the continuous current welds with a single curve. Simple equations using this parameter and empirical data were developed, which show that the maximum melting efficiency for two-dimensional heat flow is significantly higher than for three-dimensional heat flow. RP FUERSCHBACH, PW (reprint author), SANDIA NATL LABS,ALBUQUERQUE,NM 87185, USA. NR 28 TC 28 Z9 28 U1 0 U2 3 PU AMER WELDING SOC PI MIAMI PA PO BOX 351040, MIAMI, FL 33135 SN 0043-2296 J9 WELD J JI Weld. J. PD NOV PY 1991 VL 70 IS 11 BP S287 EP S297 PG 11 WC Metallurgy & Metallurgical Engineering SC Metallurgy & Metallurgical Engineering GA GM741 UT WOS:A1991GM74100016 ER PT J AU NALEWAY, CA CURTISS, LA MILLER, JR AF NALEWAY, CA CURTISS, LA MILLER, JR TI SUPEREXCHANGE-PATHWAY MODEL FOR LONG-DISTANCE ELECTRONIC COUPLINGS SO JOURNAL OF PHYSICAL CHEMISTRY LA English DT Letter ID THROUGH-BOND INTERACTION; DONOR-ACCEPTOR SYSTEMS; PHOTOINDUCED CHARGE SEPARATION; TRANSFER MATRIX-ELEMENTS; TRANSFER ABSORPTION; INVERTED REGION; POSITIVE-CHARGE; FIXED-DISTANCE; RANGE ELECTRON; RADICAL-ANIONS AB Long-distance electronic couplings for electron-transfer reactions are calculated in a method which makes use of McConnell's superexchange model. The necessary matrix elements come from ab initio molecular orbital calculations by transforming the UHF wave function to localized bond orbitals using Weinhold's natural bond orbital method. The result is a series of visualizable pathways between the donor (D) and acceptor (A) groups. When the material between the donor and acceptor is a saturated hydrocarbon, it is found that (1) the bulk of the interaction comes from pathways which "skip" over some bonds in contrast to the more usual "tight binding" picture, (2) C-C bonds provide most of the interaction, and (3) pathways containing C-H bonds give smaller contributions but cannot be neglected because they give rise to a large number of pathways. The method appears to have excellent potential for developing an understanding of how electronic coupling is transmitted through molecular material between donor and acceptor groups. C1 ARGONNE NATL LAB,DIV CHEM,ARGONNE,IL 60439. ARGONNE NATL LAB,DIV CHEM TECHNOL,ARGONNE,IL 60439. ARGONNE NATL LAB,DIV MAT SCI,ARGONNE,IL 60439. NR 85 TC 123 Z9 123 U1 2 U2 10 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 SN 0022-3654 J9 J PHYS CHEM-US JI J. Phys. Chem. PD OCT 31 PY 1991 VL 95 IS 22 BP 8434 EP 8437 DI 10.1021/j100175a005 PG 4 WC Chemistry, Physical SC Chemistry GA GX469 UT WOS:A1991GX46900005 ER PT J AU GLAUSER, WA KOSZYKOWSKI, ML AF GLAUSER, WA KOSZYKOWSKI, ML TI VIBRATIONAL DISPERSION INTERACTIONS IN VANDERWAALS COMPLEXES - EFFECT UPON STABILITY AND INFRARED-SPECTRA SO JOURNAL OF PHYSICAL CHEMISTRY LA English DT Article ID INTERMOLECULAR FORCES; ELECTRON-DONOR; BASIS-SETS; SPECTROSCOPY; MOLECULES; ETHYLENE; SYSTEMS; INTENSITIES; EXPANSIONS; ENERGIES AB The vibrational analogue of London dispersion forces has been studied for a generalized bimolecular complex, and calculations have been performed for a series of van der Waals complexes comprised of subunits CO2, C2H4, and HCN. We present a generalized nonempirical perturbational methodology for evaluating the second-order stabilization resulting from the correlation between instantaneous monomeric vibrational motions using the harmonic approximation. We find that these second-order energies are typically on the order of 0.01 cm-1, with the relative ordering (CO2)2 > (CO2-HCN) > (HCN-C2H4) > (C2H4)2. In conjunction with first-order resonance energies, the shift in monomer vibrational energy levels upon complexation is evaluated. We conclude that although the effect of vibrational dispersion upon the stability of a complex is quite small, its effect upon infrared spectra can be potentially significant. The formalisms for electronic and vibrational dispersion are compared and contrasted. The limitations of this nonempirical scheme for the calculation of vibrational dispersion energies are discussed in light of the approximations that are needed to make the calculations tractable and applicable to large systems. RP GLAUSER, WA (reprint author), SANDIA NATL LABS, COMBUST RES FACIL, LIVERMORE, CA 94551 USA. NR 54 TC 1 Z9 1 U1 0 U2 0 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 0022-3654 J9 J PHYS CHEM-US JI J. Phys. Chem. PD OCT 31 PY 1991 VL 95 IS 22 BP 8507 EP 8517 DI 10.1021/j100175a019 PG 11 WC Chemistry, Physical SC Chemistry GA GX469 UT WOS:A1991GX46900019 ER PT J AU HARDING, LB AF HARDING, LB TI THEORETICAL-STUDIES OF THE HYDROGEN-PEROXIDE POTENTIAL SURFACE .2. AN ABINITIO, LONG-RANGE, OH(2-PI) + OH(2-PI) POTENTIAL SO JOURNAL OF PHYSICAL CHEMISTRY LA English DT Article ID BEAM ELECTRIC RESONANCE; WATER DIMER; ASSOCIATION; STATE; HOOH; H2O AB Ab initio, multireference, CI calculations have been used to characterize the long-range interaction potentials between two OH radicals. The calculations predict that the four singlet surfaces correlating with ground-state OH radicals interact very strongly, resulting in a complex addition reaction path. At very long range (O-O separations of more than 8 angstrom) the character of the surfaces is dominated by the electrostatic, dipole-dipole interaction, and consequently, the four surfaces are nearly degenerate. At intermediate distances (O-O separations of 3-6 angstrom) hydrogen bonding is found to be the dominant attractive force. In this region the four singlet surfaces split into two pairs, with one pair being significantly more attractive than the other. At shorter distances (O-O separations less than 2.5 angstrom), covalent bonding becomes important. In this region there is only one attractive singlet surface. Sharp, avoided crossings occur at O-O separations between 2.5 and 3 angstrom where the lowest energy wave function switches from hydrogen bonding in character to covalent bonding. In this region, the orientation of the minimum-energy path also changes rapidly from a hydrogen-bonding orientation (OOH angle of 0-degrees) to a covalent bonding orientation (OOH angle of 90-degrees). RP HARDING, LB (reprint author), ARGONNE NATL LAB,DIV CHEM,ARGONNE,IL 60439, USA. NR 19 TC 51 Z9 51 U1 1 U2 3 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 SN 0022-3654 J9 J PHYS CHEM-US JI J. Phys. Chem. PD OCT 31 PY 1991 VL 95 IS 22 BP 8653 EP 8660 DI 10.1021/j100175a044 PG 8 WC Chemistry, Physical SC Chemistry GA GX469 UT WOS:A1991GX46900044 ER PT J AU BALLA, RJ CASLETON, KH ADAMS, JS PASTERNACK, L AF BALLA, RJ CASLETON, KH ADAMS, JS PASTERNACK, L TI ABSOLUTE RATE CONSTANTS FOR THE REACTION OF CN WITH CH4, C2H6, AND C3H8 FROM 292-K TO 1500-K USING HIGH-TEMPERATURE PHOTOCHEMISTRY AND DIODE-LASER ABSORPTION SO JOURNAL OF PHYSICAL CHEMISTRY LA English DT Article ID THERMAL-DECOMPOSITION; SHOCK-TUBE; KINETICS; BANDS; HCN; SPECTROSCOPY; CYANOGEN; PHOTODISSOCIATION; DISSOCIATION; OXIDATION AB By combining the laser-induced fluorescence detection technique with high-temperature reactor technology, absolute rate constants for the reaction of CN with CH4, C2H6, and C3H8 have been measured as a function of temperature (292-1500 K) and pressure (5-60 Torr). CN radicals were generated by 193-nm excimer laser photolysis of dilute C2N2/Ar mixtures. Radical decays were monitored by laser-induced fluorescence from the B2-SIGMA+ <-- X2-SIGMA+ transition near 387 nm under pseudo-first-order conditions. Arrhenius plots of the rate constants show significant curvature. The temperature-dependent rate constants have been fit to modified Arrhenius expressions of the form k = AT(n) exp(-E/T). This study represents the widest continuous temperature range over which rate constants for these reactions have been measured directly. The reaction kinetics and products of these reactions were also studied at 295 K by diode laser absorption. Rate constants obtained from product growth are in good agreement with the laser-induced fluorescence data. For these reactions at 295 K, HCN was found to be the dominant observable product. C1 US DOE,MORGANTOWN ENERGY TECHNOL CTR,POB 880,MORGANTOWN,WV 26507. USN,RES LAB,DIV CHEM,WASHINGTON,DC 20375. NR 44 TC 37 Z9 37 U1 1 U2 7 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 SN 0022-3654 J9 J PHYS CHEM-US JI J. Phys. Chem. PD OCT 31 PY 1991 VL 95 IS 22 BP 8694 EP 8701 DI 10.1021/j100175a051 PG 8 WC Chemistry, Physical SC Chemistry GA GX469 UT WOS:A1991GX46900051 ER PT J AU YARWOOD, G SUTHERLAND, JW WICKRAMAARATCHI, MA KLEMM, RB AF YARWOOD, G SUTHERLAND, JW WICKRAMAARATCHI, MA KLEMM, RB TI DIRECT RATE-CONSTANT MEASUREMENTS FOR THE REACTION O + NO + AR-]NO2 + AR AT 300-1341-K SO JOURNAL OF PHYSICAL CHEMISTRY LA English DT Article ID PHOTOLYSIS-SHOCK-TUBE; ABSOLUTE RATE PARAMETERS; STATE ATOMIC OXYGEN; FLASH-PHOTOLYSIS; ETHYLENE; KINETICS; O(P-3); WAVES; O(3P); CH4 AB Rate constants for the title reaction were measured by two independent techniques: flash photolysis-resonance fluorescence 300-1001 K, and flash photolysis-shock tube, 915-1341 K. In all cases, low-pressure-limit conditions prevailed. The data are well fitted, over the entire experimental temperature span (300-1341 K), by the expression k1(0)(M = Ar) = (6.7 +/- 0.1) x 10(-32)(T/300)-1.41+/-0.02 cm6 molecule-2 s-1. The present values, which fill in a gap in experimental measurements from 500 to 1450 K, are compared to those of previous studies and evaluations. Also, the strong collision, low-pressure rate constant (k1(0,SC)) and the collisional efficiency factor (beta(c)) are calculated over the temperature range 300-2000 K, and beta(c) is compared with previously reported results. C1 BROOKHAVEN NATL LAB,BLDG 815,UPTON,NY 11973. NR 36 TC 24 Z9 24 U1 1 U2 1 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 SN 0022-3654 J9 J PHYS CHEM-US JI J. Phys. Chem. PD OCT 31 PY 1991 VL 95 IS 22 BP 8771 EP 8775 DI 10.1021/j100175a065 PG 5 WC Chemistry, Physical SC Chemistry GA GX469 UT WOS:A1991GX46900065 ER PT J AU JIN, YM WUNDERLICH, B AF JIN, YM WUNDERLICH, B TI HEAT-CAPACITIES OF PARAFFINS AND POLYETHYLENE SO JOURNAL OF PHYSICAL CHEMISTRY LA English DT Article ID CARBON BACKBONE POLYMERS; LINEAR MACROMOLECULES; THERMODYNAMIC PROPERTIES; SKELETAL VIBRATIONS; ADDITION SCHEME AB The heat capacities of the homologous series of paraffins from n-propane to polyethylene in the solid state are analyzed by use of the advanced thermal analysis system (ATHAS) developed for linear macromolecules. While the skeletal heat capacity contributions linked to the intramolecular vibrations follow a simple functional relationship with the number of chain atoms [THETA-1 = 519 - 3508/n2], one detects for the beat capacities linked to the intermolecular vibrations a clear odd/even fluctuation [THETA-3odd = 158 - 116.7/square-root n; THETA-3even = 158 - 103.6/square-root n]. All prior measured data are included in the analysis in addition to new data on n-hexatriacontane (C36H74), n-tetratetracontane (C44H90), and n-pentacontane (C50H102). Similarly, the heat capacities in the liquid state can be generated within a precision of +/- 1.7% (rms error), using empirical contributions from the CH2 and CH3 groups [C(p)CH2 = 17.33 + 0.04551 T; C(p)CH3 = 30.41 + 0.01479T]. With heat capacities of the solid and liquid known, the transitions and thermal functions H, S, and G can be derived and extrapolated to paraffins not measured. For all homologues a large increase in heat capacity beyond that expected from the contributions of vibrations is observed 50-100 K below the fusion temperature. This increase in heat capacity is shown to be in line with the gradual increase in conformational disorder proven by polyethylene crystal simulation using supercomputers. C1 UNIV TENNESSEE,DEPT CHEM,KNOXVILLE,TN 37996. OAK RIDGE NATL LAB,DIV CHEM,OAK RIDGE,TN 37831. NR 49 TC 60 Z9 60 U1 1 U2 10 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 SN 0022-3654 J9 J PHYS CHEM-US JI J. Phys. Chem. PD OCT 31 PY 1991 VL 95 IS 22 BP 9000 EP 9007 DI 10.1021/j100175a105 PG 8 WC Chemistry, Physical SC Chemistry GA GX469 UT WOS:A1991GX46900105 ER PT J AU VANAMERONGEN, H STRUVE, WS AF VANAMERONGEN, H STRUVE, WS TI EXCITED-STATE ABSORPTION IN BACTERIOCHLOROPHYLL-A-PROTEIN FROM THE GREEN PHOTOSYNTHETIC BACTERIUM PROSTHECOCHLORIS-AESTUARII - REINTERPRETATION OF THE ABSORPTION DIFFERENCE SPECTRUM SO JOURNAL OF PHYSICAL CHEMISTRY LA English DT Article ID PHOTOSYSTEM-I PARTICLES; SPECTROSCOPY AB Excited-state absorption arising from transitions between singly and doubly excited exciton components in strongly coupled photosynthetic antennae profoundly influences the absorption difference spectra observed in pump-probe spectroscopy. Model calculations of the absorption difference spectrum in the BChl a-protein complex from P. aestuarii are compared with the experimental spectrum. C1 IOWA STATE UNIV SCI & TECHNOL,AMES LAB,AMES,IA 50011. IOWA STATE UNIV SCI & TECHNOL,DEPT CHEM,AMES,IA 50011. RI van Amerongen, Herbert/J-9483-2016 OI van Amerongen, Herbert/0000-0002-9783-2895 NR 20 TC 19 Z9 19 U1 1 U2 1 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 SN 0022-3654 J9 J PHYS CHEM-US JI J. Phys. Chem. PD OCT 31 PY 1991 VL 95 IS 22 BP 9020 EP 9023 DI 10.1021/j100175a108 PG 4 WC Chemistry, Physical SC Chemistry GA GX469 UT WOS:A1991GX46900108 ER PT J AU COVEY, C AF COVEY, C TI CLIMATE CHANGE - CHAOS IN OCEAN HEAT-TRANSPORT SO NATURE LA English DT Editorial Material ID CIRCULATION RP COVEY, C (reprint author), UNIV CALIF LAWRENCE LIVERMORE NATL LAB,MAIL STOP L-264,LIVERMORE,CA 94551, USA. NR 6 TC 2 Z9 2 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 OCT 31 PY 1991 VL 353 IS 6347 BP 796 EP 797 DI 10.1038/353796d0 PG 2 WC Multidisciplinary Sciences SC Science & Technology - Other Topics GA GM732 UT WOS:A1991GM73200034 ER PT J AU HOLMAN, R KOLB, EW VADAS, SL WANG, Y AF HOLMAN, R KOLB, EW VADAS, SL WANG, Y TI PLAUSIBLE DOUBLE INFLATION SO PHYSICS LETTERS B LA English DT Article ID DENSITY PERTURBATIONS; EXTENDED INFLATION; UNIVERSE; FLUCTUATIONS; GENERATION; COSMOLOGY AB It is likely that extended inflation is followed by an epoch of slowroll inflation. Such a sequence of events may lead to a very interesting perturbation spectrum with significant power on the scale of the transition between the extended and slowroll phase, superimposed upon a power-law spectrum with deviations from the Harrison-Zel'dovich slope. Normalization of the spectra above and below the transition scale is expected to differ. C1 UNIV CHICAGO,ENRICO FERMI INST,CHICAGO,IL 60637. FERMI NATL ACCELERATOR LAB,NASA FERMILAB ASTROPHYS CTR,BATAVIA,IL 60510. UNIV CHICAGO,DEPT ASTRON & ASTROPHYS,CHICAGO,IL 60637. UNIV CHICAGO,DEPT PHYS,CHICAGO,IL 60637. RP HOLMAN, R (reprint author), CARNEGIE MELLON UNIV,DEPT PHYS,PITTSBURGH,PA 15213, USA. RI Wang, Yun/B-5724-2011 OI Wang, Yun/0000-0002-4749-2984 NR 20 TC 50 Z9 50 U1 0 U2 0 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0370-2693 J9 PHYS LETT B JI Phys. Lett. B PD OCT 31 PY 1991 VL 269 IS 3-4 BP 252 EP 256 DI 10.1016/0370-2693(91)90165-M PG 5 WC Astronomy & Astrophysics; Physics, Nuclear; Physics, Particles & Fields SC Astronomy & Astrophysics; Physics GA GP904 UT WOS:A1991GP90400003 ER PT J AU DEALWIS, SP LYKKEN, J AF DEALWIS, SP LYKKEN, J TI 2D GRAVITY AND THE BLACK-HOLE SOLUTION IN 2D CRITICAL STRING THEORY SO PHYSICS LETTERS B LA English DT Article ID 2-DIMENSIONAL QUANTUM-GRAVITY; FIELD-THEORY; BACKGROUND FIELDS; CRITICAL-BEHAVIOR; BETA-FUNCTIONS; RENORMALIZATION; EQUATIONS; DIMENSION; MOTION; MODELS AB We discuss the relation between 2D gravity and critical string theory in two target space dimensions. In particular we consider the effect that the tachyon, and its back reaction on the metric, has on the interpretation of the critical theory as a non-critical theory coupled to world sheet gravity. We examine the generalizations of the black hole solution of the critical theory and argue that a generic feature of these solutions is that they have two horizons, similar to, but distinct from, the Reissner-Nordstrom black hole. We also find some indication that the tachyon may destabilize a naked singularity. Finally we show that KPZ scaling is valid for the general solution of the critical theory, when it is interpreted as a theory of world sheet gravity. C1 FERMI NATL ACCELERATOR LAB, THEORY GRP, BATAVIA, IL 60510 USA. RP UNIV COLORADO, DEPT PHYS, BOX 390, BOULDER, CO 80309 USA. OI DE ALWIS, SENARATH/0000-0002-6907-947X NR 39 TC 28 Z9 28 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 OCT 31 PY 1991 VL 269 IS 3-4 BP 264 EP 270 DI 10.1016/0370-2693(91)90167-O PG 7 WC Astronomy & Astrophysics; Physics, Nuclear; Physics, Particles & Fields SC Astronomy & Astrophysics; Physics GA GP904 UT WOS:A1991GP90400005 ER PT J AU SCOTT, SL BAKAC, A ESPENSON, JH AF SCOTT, SL BAKAC, A ESPENSON, JH TI CATALYTIC-OXIDATION OF THE (HYDROXYMETHYL)CHROMIUM(III) ION BY THE SUPEROXOCHROMIUM(III) ION SO INORGANIC CHEMISTRY LA English DT Article ID CHROMIC ACID OXIDATION; ELECTRON-TRANSFER; AQUEOUS-SOLUTION; MACROCYCLIC LIGANDS; REDUCTION REACTIONS; "(MU-OXO)BIS(PENTAAQUOCHROMIUM(III)) ION; IRON(III) PORPHYRINS; METAL-IONS; COMPLEXES; DIOXYGEN AB The superoxochromium(III) ion, CrO22+, is an efficient catalyst for autoxidation of the (hydroxymethyl)chromium(III) ion, CrCH2OH2+, in aqueous solution. The reaction involves one-electron oxidation of CrCH2OH2+ by CrO22+, k = 137 M-1 s-1, to yield Cr2+, CH2O, and the novel (hydroperoxo)chromium(III) ion, CrO2H2+. The Cr2+ produced reacts rapidly with O2 to regenerate the catalyst, CrO22+. When oxygen is depleted, the Cr2+ reacts instead with CrO22+ to produce the chromyl(IV) ion, CrO2+. This initiates a chain reaction that rapidly consumes the remaining CrO22+ and a stoichiometric amount of CrCH2OH2+. C1 IOWA STATE UNIV SCI & TECHNOL,AMES LAB,AMES,IA 50011. IOWA STATE UNIV SCI & TECHNOL,DEPT CHEM,AMES,IA 50011. NR 66 TC 20 Z9 20 U1 0 U2 1 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 SN 0020-1669 J9 INORG CHEM JI Inorg. Chem. PD OCT 30 PY 1991 VL 30 IS 22 BP 4112 EP 4117 DI 10.1021/ic00022a006 PG 6 WC Chemistry, Inorganic & Nuclear SC Chemistry GA GM765 UT WOS:A1991GM76500006 ER PT J AU CARPENTER, BF OLSON, DL MATLOCK, DK CIESLAK, MJ AF CARPENTER, BF OLSON, DL MATLOCK, DK CIESLAK, MJ TI PHASE-STABILITY OF FE-AL-CR-NI WELD METAL SO MATERIALS SCIENCE AND ENGINEERING A-STRUCTURAL MATERIALS PROPERTIES MICROSTRUCTURE AND PROCESSING LA English DT Article AB The weld metal microstructures of three austenitic iron-based alloys have been examined analytically using electron microscopy techniques. These alloys, having the designations Fe-2Al-8Cr-20Ni, Fe-4Al-10Cr-20Ni and Fe-5Al-14Cr-25Ni, are similar in composition to stainless steels with high aluminum additions. Electron microanalysis of the solidification structure revealed that aluminum and chromium had segregated to the interdendritic volume. Nickel and iron were found to be depleted within the interdendritic volume. Austenite phase stability was evaluated by annealing each of the alloys. At a temperature of 750-degrees-C, sigma-phase was observed in both the Fe-4Al-10Cr-20Ni and Fe-5Al-14Cr-25Ni alloys after 2 h. The Fe-2Al-8Cr-20Ni weld metal did not form sigma-phase after annealing for 100 h. Phase stability is a function of composition and as such is expected to change with position across solidification microstructures. New PHACOMP calculations have been used to describe this change in terms of a metal d level M(d). The M(d) level was found to increase in traversing from the dendrite core towards the interdendritic volume. For each of the weld metals investigated the M(d) level calculated within the interdendritic volume exceeded the critical M(d) value for sigma-phase formation. The new PHACOMP results correlate with the changes in microstructure observed for Fe-5Al-14Cr-25Ni and Fe-4Al-10Cr-20Ni weld metals. The behavior of Fe-2Al-8Cr-20Ni weld metal can be explained by modifying the New PHACOMP model to account for compositional changes that occur during annealing. Homogenization provides a mechanism of reducing the M(d) level of the alloy, increasing its stability. If the maximum M(d) level can be reduced to some value below the critical M(d) level before nucleation of sigma-phase, then alloys which are unstable in the as-welded condition can be made stable during homogenization. The development of the modified version of New PHACOMP and the limitation of its application are presented. C1 SANDIA NATL LABS,ALBUQUERQUE,NM 87185. RP CARPENTER, BF (reprint author), COLORADO SCH MINES,CTR WELDING & JOINING RES,GOLDEN,CO 80401, USA. NR 7 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 0921-5093 J9 MAT SCI ENG A-STRUCT JI Mater. Sci. Eng. A-Struct. Mater. Prop. Microstruct. Process. PD OCT 30 PY 1991 VL 147 IS 1 BP 1 EP 8 DI 10.1016/0921-5093(91)90799-S PG 8 WC Nanoscience & Nanotechnology; Materials Science, Multidisciplinary; Metallurgy & Metallurgical Engineering SC Science & Technology - Other Topics; Materials Science; Metallurgy & Metallurgical Engineering GA GQ565 UT WOS:A1991GQ56500001 ER PT J AU SEKHAR, JA TRIVEDI, R AF SEKHAR, JA TRIVEDI, R TI SOLIDIFICATION MICROSTRUCTURE EVOLUTION IN THE PRESENCE OF INERT PARTICLES SO MATERIALS SCIENCE AND ENGINEERING A-STRUCTURAL MATERIALS PROPERTIES MICROSTRUCTURE AND PROCESSING LA English DT Article ID DENDRITIC GROWTH; RAPID SOLIDIFICATION; COMPOSITES; INTERFACE; STABILITY AB The development of solidification microstructure can be significantly influenced by the presence of inert particles in the liquid during the processing of particulate composites by the solidification techniques. The effect of particles on the microstructural development is characterized through directional solidification experiments in a transparent organic system, succinonitrile, in which the interactions between the particles and the interface can be examined in situ. These particle-interface interactions have been examined in an alloy system in which the long-range solute field interactions between the particles and the interface are dominant. These interactions have been found to be significantly different for different interface morphologies, i.e. planar, cellular or dendritic interfaces. The effect of particles on the morphological changes and on the nature of the particle trapping processes are characterized for different particle distributions, particle sizes and interface morphologies. It is shown that the presence of particles in binary alloys can either cause the instability of the interface, such as dendrite tip splitting, or lead to morphological transitions, such as a dendritic-to-cellular transition. When the particle density is large, the presence of particles significantly influences the interface shape and thereby alters the interface growth characteristics such that an oscillatory behavior of the interface can be obtained under constant externally imposed velocity. Appropriate theoretical ideas are developed to explain the effects of particles on the morphological development of the interface. C1 US DOE,AMES LAB,AMES,IA 50011. IOWA STATE UNIV SCI & TECHNOL,DEPT MAT SCI & ENGN,AMES,IA 50011. RP SEKHAR, JA (reprint author), UNIV CINCINNATI,DEPT MAT SCI & ENGN,CINCINNATI,OH 45221, USA. NR 23 TC 53 Z9 53 U1 3 U2 9 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 OCT 30 PY 1991 VL 147 IS 1 BP 9 EP 21 DI 10.1016/0921-5093(91)90800-3 PG 13 WC Nanoscience & Nanotechnology; Materials Science, Multidisciplinary; Metallurgy & Metallurgical Engineering SC Science & Technology - Other Topics; Materials Science; Metallurgy & Metallurgical Engineering GA GQ565 UT WOS:A1991GQ56500002 ER PT J AU BALDRIDGE, WS EYAL, Y BARTOV, Y STEINITZ, G EYAL, M AF BALDRIDGE, WS EYAL, Y BARTOV, Y STEINITZ, G EYAL, M TI MIOCENE MAGMATISM OF SINAI RELATED TO THE OPENING OF THE RED-SEA SO TECTONOPHYSICS LA English DT Article; Proceedings Paper CT SYMP ON WORLD RIFT SYSTEMS CY APR 27-28, 1989 CL TEXAS A&M UNIV, COLLEGE STN, TX SP NASA, INTER UNION COMMISS LITHOSPHERE HO TEXAS A&M UNIV ID FLOOD-BASALT PROVINCE; ARABIAN COASTAL-PLAIN; X-RAY-FLUORESCENCE; OCEANIC LITHOSPHERE; CONTINENTAL-MARGIN; WESTERN MARGIN; SUEZ RIFT; EVOLUTION; GULF; HISTORY AB Extension associated with the initial (early Miocene) stages of opening of the Red Sea resulted in intrusion of a widespread system of dikes and smaller bodies, primarily along the northeastern margin of the Red Sea/Gulf of Suez axis. Dikes, some up to more than 800 km in length, were emplaced dominantly parallel to the Red Sea/Gulf of Suez from the Sinai Peninsula to Yemen. Intrusive rocks are mainly basaltic in composition, but minor granophyres are also present. In the Sinai, this magmatic event is about 20 m.y. old. Dikes of the southern and southeastern Sinai crop out in Precambrian terrane. In the central and northern Sinai, they occur in Phanerozoic terrane, where they may be associated with linear grabens and cryptovolcanic features. Basaltic dikes of the Sinai underwent variable degrees of alteration. Alteration phases include sericite, quartz, smectite, chlorite, and serpentine. X-ray diffraction and petrographic analysis indicate that, in spite of extensive alteration, primary minerals still control the major-element compositions of the rocks. Basalts are tholeiitic in composition, with SiO2 = 48.5 to 50%, and Na2O + K2O = 3 to 3.5%. Rb and Sr concentrations are probably dominated by alteration and by introduction of secondary material (primarily carbonate). Zr/TiO2, which is relatively unchanged during alteration, substantiates that the basaltic rocks are subalkaline. Initial Sr-87/Sr-86, determined after leaching of samples, is approximately 0.7043-0.7063, much higher than Red Sea axial trough basalts (< 0.703). We infer that these Sinai basalts equilibrated at depths of 35-50 km, possibly within an enriched mantle. Whether the main trough of the Red Sea is underlain by extended and modified continental crust or by oceanic crust is controversial. Since Miocene dikes were intruded along both coasts (but primarily the Saudi Arabian coast) of the Red Sea/Gulf of Suez axis in a zone up to 150 km wide, they may also underlie the main trough of the Red Sea and result, at least partially, in the discontinuous magnetic and gravity anomalies observed there. Possibly the abundance of dikes beneath the main trough is much greater than adjacent to the Red Sea, giving rise to properties intermediate between those of continental and oceanic crust. Downwarping and widespread intrusion of dikes along the Red Sea 18-26 m.y. ago probably signified crustal dilation and the initiation of a continental rift. Because tholeiitic basalts of the Sinai are higher in Sr-87/Sr-86 than Red Sea axial trough basalts, we infer that the conditions of their origin must also be very different. We suggest that the Sinai basalts may have been generated within but near the base of subcrustal continental lithosphere, perhaps indicating thermal thinning of lithospheric mantle above upwelled asthenosphere associated with continental rifting. This inference, if correct, would indicate that the lithosphere was at least 35-50 km thick during the early Miocene phase of rifting but possibly not much thicker. Since dikes farthest from the Red Sea are apparently identical in composition to those closest, asthenospheric upwarping must have been broad enough that all magmas were derived from approximately the same depth. In the Yemen-Ethiopia areas, volcanism began earlier (about 30 m.y. ago) and was much more voluminous than elsewhere along the Red Sea/Gulf of Suez axis, suggesting the presence of underlying mantle upwelling accompanying rifting of the Red Sea. In spite of differences in age and volume, the presence of large volumes of tholeiites among the Miocene basalts of the Yemen-Ethiopia areas suggests that the lithosphere was similarly thinned along the entire length of the Red Sea. C1 GEOL SURVEY ISRAEL,IL-95501 JERUSALEM,ISRAEL. BEN GURION UNIV NEGEV,DEPT GEOL & MINERAL,IL-84105 BEER SHEVA,ISRAEL. RP BALDRIDGE, WS (reprint author), UNIV CALIF LOS ALAMOS SCI LAB,DIV EARTH & ENVIRONM SCI,MS D462,LOS ALAMOS,NM 87545, USA. NR 64 TC 29 Z9 29 U1 0 U2 0 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0040-1951 J9 TECTONOPHYSICS JI Tectonophysics PD OCT 30 PY 1991 VL 197 IS 2-4 BP 181 EP 201 DI 10.1016/0040-1951(91)90040-Y PG 21 WC Geochemistry & Geophysics SC Geochemistry & Geophysics GA GQ737 UT WOS:A1991GQ73700007 ER PT J AU BALDRIDGE, WS PERRY, FV VANIMAN, DT NEALEY, LD LEAVY, BD LAUGHLIN, AW KYLE, P BARTOV, Y STEINITZ, G GLADNEY, ES AF BALDRIDGE, WS PERRY, FV VANIMAN, DT NEALEY, LD LEAVY, BD LAUGHLIN, AW KYLE, P BARTOV, Y STEINITZ, G GLADNEY, ES TI MIDDLE TO LATE CENOZOIC MAGMATISM OF THE SOUTHEASTERN COLORADO PLATEAU AND CENTRAL RIO-GRANDE RIFT (NEW-MEXICO AND ARIZONA, USA) - A MODEL FOR CONTINENTAL RIFTING SO TECTONOPHYSICS LA English DT Article; Proceedings Paper CT SYMP ON WORLD RIFT SYSTEMS CY APR 27-28, 1989 CL TEXAS A&M UNIV, COLLEGE STN, TX SP NASA, INTER UNION COMMISS LITHOSPHERE HO TEXAS A&M UNIV ID JEMEZ VOLCANIC FIELD; NORTHERN NEW-MEXICO; K-AR DATES; EVOLUTION; GEOCHEMISTRY; ROCKS; LITHOSPHERE; SYSTEMATICS; EXTENSION; PETROLOGY AB The region of the present Rio Grande rift and southeastern Colorado Plateau underwent lithospheric extension during middle to late Cenozoic deformation affecting the entire southwestern U.S. Lithospheric mantle was disrupted, and in many regions displaced or replaced by asthenospheric mantle at depths from which basaltic magmas were derived and erupted to the surface. Study of the igneous rocks erupted or intruded during this deformation yields insights into processes of magmatism associated with extension of continental lithosphere. Magmatic rocks associated with an early (late Oligocene-early Miocene) ductile phase of extension are dominantly basaltic andesites and related, calc-alkaline intermediate to silicic derivative rocks. Mafic magmas were probably derived from isotopically "enriched" lithospheric mantle. Igneous rocks associated with a later (middle Miocene-Holocene), more brittle phase of extension include widespread basaltic rocks and localized central volcanoes of intermediate to silicic composition. Isotopic compositions of mafic rocks, which include both tholeiitic and alkalic basalts, correlate strongly with tectonic setting and lithospheric structure. Basalts erupted in areas of greatest crustal extension, such as the central and southern rift and Basin and Range province, were derived from isotopically "depleted" (correlated with "asthenospheric") mantle. Also, isotopic compositions of Pliocene to Holocene basalts are slightly more depleted than those of Miocene basalts, suggesting that subcrustal lithospheric mantle was thinned during late Miocene extension. Intermediate rocks of the central volcanoes formed by a complex combination of processes, probably dominated by fractional crystallization and by assimilation of upper and lower crust in isolated, small magma chambers. The petrologic, geochemical, and isotopic data are compatible with a model, derived first from geophysical data, whereby lithosphere is thinned beneath the central rift and southeastern Colorado Plateau, with greatest thinning centered beneath the axis of the rift. A lithospheric model involving uniform-sense simple shear does not appear compatible with the data as presently understood. C1 GEOL SURVEY ISRAEL,IL-95501 JERUSALEM,ISRAEL. UNIV CALIF LOS ALAMOS SCI LAB,DIV HLTH SAFETY & ENVIRONM,LOS ALAMOS,NM 87545. UNIV NEW MEXICO,DEPT GEOL,ALBUQUERQUE,NM 87131. US GEOL SURVEY,DENVER FED CTR,DENVER,CO 80225. NEW MEXICO INST MIN & TECHNOL,DEPT GEOSCI,SOCORRO,NM 87801. RP BALDRIDGE, WS (reprint author), UNIV CALIF LOS ALAMOS SCI LAB,DIV EARTH & ENVIRONM SCI,MS D462,LOS ALAMOS,NM 87545, USA. NR 69 TC 30 Z9 30 U1 0 U2 15 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0040-1951 J9 TECTONOPHYSICS JI Tectonophysics PD OCT 30 PY 1991 VL 197 IS 2-4 BP 327 EP 354 DI 10.1016/0040-1951(91)90049-X PG 28 WC Geochemistry & Geophysics SC Geochemistry & Geophysics GA GQ737 UT WOS:A1991GQ73700016 ER PT J AU KELLER, GR KHAN, MA MORGAN, P WENDLANDT, RF BALDRIDGE, WS OLSEN, KH PRODEHL, C BRAILE, LW AF KELLER, GR KHAN, MA MORGAN, P WENDLANDT, RF BALDRIDGE, WS OLSEN, KH PRODEHL, C BRAILE, LW TI A COMPARATIVE-STUDY OF THE RIO-GRANDE AND KENYA RIFTS SO TECTONOPHYSICS LA English DT Article ID SOUTHERN NEW-MEXICO; EAST-AFRICA; GREGORY RIFT; WEST TEXAS; HEAT-FLOW; GRAVITY INTERPRETATION; TECTONIC DEVELOPMENT; CRUSTAL STRUCTURE; COLORADO PLATEAU; CONTINENTAL RIFT AB Since they are two of the prominent continental rifts which are active today, the Kenya and Rio Grande rifts have been the subject of many recent studies. There are many gaps in our knowledge, but the data available make a comparative analysis worthwhile. Although they are part of much larger extensional regimes, these rifts are of similar dimensions and extent. In addition to these obvious similarities, geophysical data suggest the crustal and upper mantle structures of these features are also similar. They both are associated with relatively localized crustal thinning and much broader zones of lithospheric thinning. Seismic and gravity data indicate that the basement structure beneath both rift valleys is very complex, and recent studies have stressed the role of low-angle normal faulting in their structural development. However, geologic data and earthquake focal mechanisms indicate that high-angle normal faults and strike-slip faulting are also important. However, as one looks at the tectonic evolution and volcanic histories of the rifts, many differences are apparent. Volcanism has been virtually continuous in the Kenya rift area for over 20 Ma and the total volume of extrusives is over 200,000 km3. Unlike the Kenya rift. the Rio Grande rift formed in a region which was already both tectonically and magmatically active. Thus, there is uncertainty about what constitutes rift volcanism in the Rio Grande rift. However, the volume of extrusives generally accepted to be associated with this rift is about 5-10% that of the Kenya rift. The compositions of the volcanics are also very different in these rifts, and the Kenya rift displays migration of volcanic activity, and compositional variations in time which have not been recognized in the Rio Grande rift. The volcanic activity in the Rio Grande rift post-dated most of the faulting, whereas faulting and volcanism display complex interactions in Kenya. The nature and timing of uplift are important but difficult questions in both rifts. C1 UNIV KARLSRUHE, INST GEOPHYS, W-7500 KARLSRUHE 21, GERMANY. PURDUE UNIV, DEPT EARTH & ATMOSPHER SCI, W LAFAYETTE, IN 47907 USA. UNIV LEICESTER, DEPT GEOL, LEICESTER LE1 7RH, ENGLAND. NO ARIZONA UNIV, DEPT GEOL, FLAGSTAFF, AZ 86011 USA. COLORADO SCH MINES, DEPT GEOL, GOLDEN, CO 80401 USA. UNIV CALIF LOS ALAMOS SCI LAB, LOS ALAMOS, NM 87545 USA. RP KELLER, GR (reprint author), UNIV TEXAS, DEPT GEOL SCI, EL PASO, TX 79968 USA. NR 115 TC 34 Z9 34 U1 0 U2 23 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0040-1951 EI 1879-3266 J9 TECTONOPHYSICS JI Tectonophysics PD OCT 30 PY 1991 VL 197 IS 2-4 BP 355 EP 371 PG 17 WC Geochemistry & Geophysics SC Geochemistry & Geophysics GA GQ737 UT WOS:A1991GQ73700017 ER PT J AU SOONG, Y RAO, VUS GORMLEY, RJ ZHONG, B AF SOONG, Y RAO, VUS GORMLEY, RJ ZHONG, B TI TEMPERATURE-PROGRAMMED DESORPTION STUDY ON MANGANESE IRON CATALYSTS SO APPLIED CATALYSIS LA English DT Article DE TEMPERATURE-PROGRAMMED DESORPTION; MANGANESE IRON; SPINEL; SYNGAS CONVERSION ID FISCHER-TROPSCH SYNTHESIS; SUPPORTED FE-MN; OXIDE CATALYSTS; CARBON-MONOXIDE; UNSUPPORTED IRON; H-2; CHEMISORPTION; SELECTIVITY; ADSORPTION; POTASSIUM AB A systematic temperature-programmed desorption (TPD) study of Mn-Fe catalysts was conducted. Hydrogen chemisorption on Mn-Fe catalysts is a highly activated process. Fe, MnO and MnFe2O4 related desorption spectra have been assigned. Hydrogen does adsorb on the spinel phase (MnFe2O4) in the form of activated adsorption. Carbon monoxide does not adsorb on the spinel phase. The results suggest that the spinel phase alone may not be an active phase for syngas conversion. C1 ACAD SINICA, INST COAL CHEM, TAIYUAN, PEOPLES R CHINA. RP SOONG, Y (reprint author), US DOE, PITTSBURGH ENERGY TECHNOL CTR, POB 10940, PITTSBURGH, PA 15236 USA. NR 26 TC 8 Z9 9 U1 4 U2 7 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0166-9834 J9 APPL CATAL PD OCT 29 PY 1991 VL 78 IS 1 BP 97 EP 108 DI 10.1016/0166-9834(91)80091-A PG 12 WC Chemistry, Physical SC Chemistry GA GN676 UT WOS:A1991GN67600007 ER PT J AU RONG, FC BUCHWALD, WR HARMATZ, M POINDEXTER, EH WARREN, WL AF RONG, FC BUCHWALD, WR HARMATZ, M POINDEXTER, EH WARREN, WL TI ELECTRON-PARAMAGNETIC-RESONANCE STUDY OF THE ISOLATED ARSENIC ANTISITE IN ELECTRON-IRRADIATED GAAS AND ITS RELATION TO THE EL2 CENTER SO APPLIED PHYSICS LETTERS LA English DT Article ID SITE DEFECTS; IDENTIFICATION; ASGA; CONVERSION; RES AB Arsenic antisites produced in GaAs by room-temperature electron irradiation (RTEI) are examined by electron paramagnetic resonance (EPR). For the first time, this RTEI antisite, which has been believed to be the isolated antisite, is found to be metastable. The most efficient photon energy for photoquenching is found to be approximately 1.15 eV, which is very close to that observed for the well-known EL2 center in undoped semi-insulating GaAs. However, the thermal recovery temperature is about 200-250 K, much higher than that for the EL2 center. C1 USA,ELECTR TECHNOL & DEVICES LAB,FT MONMOUTH,NJ 07703. SANDIA NATL LABS,ALBUQUERQUE,NM 87185. NR 18 TC 2 Z9 2 U1 0 U2 0 PU AMER INST PHYSICS PI WOODBURY PA CIRCULATION FULFILLMENT DIV, 500 SUNNYSIDE BLVD, WOODBURY, NY 11797-2999 SN 0003-6951 J9 APPL PHYS LETT JI Appl. Phys. Lett. PD OCT 28 PY 1991 VL 59 IS 18 BP 2281 EP 2283 DI 10.1063/1.106043 PG 3 WC Physics, Applied SC Physics GA GM040 UT WOS:A1991GM04000026 ER PT J AU MILLER, D RICHARDS, PL ETEMAD, S INAM, A VENKATESAN, T DUTTA, B WU, XD EOM, CB GEBALLE, TH NEWMAN, N COLE, BF AF MILLER, D RICHARDS, PL ETEMAD, S INAM, A VENKATESAN, T DUTTA, B WU, XD EOM, CB GEBALLE, TH NEWMAN, N COLE, BF TI RESIDUAL LOSSES IN EPITAXIAL THIN-FILMS OF YBA2CU3O7 FROM MICROWAVE TO SUBMILLIMETER WAVE FREQUENCIES SO APPLIED PHYSICS LETTERS LA English DT Article ID FAR-INFRARED REFLECTIVITY; HIGH-TC; INSITU; CONDUCTIVITY; PENETRATION AB We have measured the residual loss in five epitaxial a-b plane films of the high-T(c) superconductor YBa2Cu3O7. Microwave measurements near 10 GHz were made by resonance techniques at 4 K. Submillimeter measurements from approximately 1.5 to 21 THz were made at 2 K by a direct absorption technique. We use a model of weakly coupled superconducting grains and a homogeneous two-fluid model to fit the data for each film below the well-known absorption edge at 13.5 THz. When the penetration depth determined from muon spin rotation measurements is used to constrain each model, the weakly coupled grain model is able to fit the measured absorptivities for all films, but the two-fluid model is less successful. C1 UNIV CALIF BERKELEY LAWRENCE BERKELEY LAB,DIV MAT SCI,BERKELEY,CA 94720. BELL COMMUN RES INC,RED BANK,NJ 07701. STANFORD UNIV,DEPT APPL PHYS,STANFORD,CA 94305. CONDUCTUS INC,SUNNYVALE,CA 94086. RP MILLER, D (reprint author), UNIV CALIF BERKELEY,DEPT PHYS,BERKELEY,CA 94720, USA. RI Venkatesan, Thirumalai/E-1667-2013; Eom, Chang-Beom/I-5567-2014; Newman, Nathan/E-1466-2011 OI Newman, Nathan/0000-0003-2819-9616 NR 19 TC 23 Z9 23 U1 0 U2 2 PU AMER INST PHYSICS PI WOODBURY PA CIRCULATION FULFILLMENT DIV, 500 SUNNYSIDE BLVD, WOODBURY, NY 11797-2999 SN 0003-6951 J9 APPL PHYS LETT JI Appl. Phys. Lett. PD OCT 28 PY 1991 VL 59 IS 18 BP 2326 EP 2328 DI 10.1063/1.106058 PG 3 WC Physics, Applied SC Physics GA GM040 UT WOS:A1991GM04000041 ER PT J AU MEES, J NAHUM, M RICHARDS, PL AF MEES, J NAHUM, M RICHARDS, PL TI NEW DESIGNS FOR ANTENNA-COUPLED SUPERCONDUCTING BOLOMETERS SO APPLIED PHYSICS LETTERS LA English DT Article AB We propose a novel antenna-coupled low T(c) supereonducting bolometer which makes use of the thermal boundary resistance and the trapping of quasiparticles at metal-superconducting interfaces. A thin strip of superconductor, whose temperature is regulated at the midpoint of its resistive transition, serves both as a resistive load to thermalize the infrared current from the antenna and as a thermometer to measure the resulting temperature rise. Calculations give a noise equivalent power (NEP) almost-equal-to 7 X 10(-16) T5/2 WHz-1/2 and a time constant tau-almost-equal-to 10(-8) T-2 s for a 2 X 2-mu-m2 thermometer area at temperature T (K). Designs for efficient on-chip rf matching and filter networks with well-defined bandpasses are presented. These detectors can be used to make frequency-multiplexed array receivers for astronomical observations at near millimeter wavelengths. C1 UNIV CALIF BERKELEY,DEPT PHYS,BERKELEY,CA 94720. UNIV CALIF BERKELEY LAWRENCE BERKELEY LAB,DIV MAT SCI,BERKELEY,CA 94720. NR 17 TC 26 Z9 27 U1 0 U2 1 PU AMER INST PHYSICS PI WOODBURY PA CIRCULATION FULFILLMENT DIV, 500 SUNNYSIDE BLVD, WOODBURY, NY 11797-2999 SN 0003-6951 J9 APPL PHYS LETT JI Appl. Phys. Lett. PD OCT 28 PY 1991 VL 59 IS 18 BP 2329 EP 2331 DI 10.1063/1.106059 PG 3 WC Physics, Applied SC Physics GA GM040 UT WOS:A1991GM04000042 ER PT J AU DEMING, TJ NOVAK, BM AF DEMING, TJ NOVAK, BM TI POLYISOCYANIDES USING [(ETA-3-C3H5)NI(OC(O)CF3)]2 - RATIONAL DESIGN AND IMPLEMENTATION OF A LIVING POLYMERIZATION CATALYST SO MACROMOLECULES LA English DT Letter ID RING-OPENING POLYMERIZATION; COORDINATION POLYMERIZATION; ALKYLIDENE COMPLEXES; NORBORNENE; PROPENE; STEREOCHEMISTRY; ISOCYANIDES; CARBENE; CHOICE; LIGAND C1 UNIV CALIF BERKELEY,DEPT CHEM,BERKELEY,CA 94720. UNIV CALIF BERKELEY,LAWRENCE BERKELEY LAB,CTR ADV MAT,BERKELEY,CA 94720. UNIV CALIF BERKELEY,LAWRENCE BERKELEY LAB,DIV MAT & CHEM SCI,BERKELEY,CA 94720. RI Deming, Timothy/I-5411-2013; OI Deming, Timothy/0000-0002-0594-5025 NR 37 TC 39 Z9 39 U1 0 U2 5 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 SN 0024-9297 J9 MACROMOLECULES JI Macromolecules PD OCT 28 PY 1991 VL 24 IS 22 BP 6043 EP 6045 DI 10.1021/ma00022a023 PG 3 WC Polymer Science SC Polymer Science GA GM483 UT WOS:A1991GM48300023 ER PT J AU BENMENAHEM, S AF BENMENAHEM, S TI 2-POINT AND 3-POINT FUNCTIONS IN THE D = 1 MATRIX MODEL SO NUCLEAR PHYSICS B LA English DT Article ID CONFORMAL FIELD-THEORY; 2-D QUANTUM-GRAVITY; RANDOM SURFACES; CLOSED STRINGS; ONE-DIMENSION; 2D AB The critical behavior of the genus-zero two-point function in the D = 1 matrix model is carefully analyzed for arbitrary embedding-space momentum. Kostov's result is recovered for momenta below a certain value P0 (which is 1/square-root-alpha' in the continuum language), with a non-universal form factor which is expressed simply in terms of the critical fermion trajectory. For momenta above P0, the Kostov scaling term is found to be subdominant. We then extend the large-N WKB treatment to calculate the genus-zero three-point function, and elucidate its critical behavior when all momenta are below P0. The resulting universal scaling behavior, its well as the non-university form factor for the three-point function, are related to the two-point functions of the individual external momenta, through the factorization familiar from continuum conformal field theories. RP BENMENAHEM, S (reprint author), STANFORD UNIV,STANFORD LINEAR ACCELERATOR CTR,STANFORD,CA 94305, USA. NR 29 TC 7 Z9 7 U1 0 U2 0 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0550-3213 J9 NUCL PHYS B JI Nucl. Phys. B PD OCT 28 PY 1991 VL 364 IS 3 BP 681 EP 702 DI 10.1016/0550-3213(91)90281-2 PG 22 WC Physics, Particles & Fields SC Physics GA GL694 UT WOS:A1991GL69400007 ER PT J AU GLENDENNING, NK MOSZKOWSKI, SA AF GLENDENNING, NK MOSZKOWSKI, SA TI RECONCILIATION OF NEUTRON-STAR MASSES AND BINDING OF THE LAMBDA IN HYPERNUCLEI SO PHYSICAL REVIEW LETTERS LA English DT Article ID NUCLEAR-MATTER; EQUATION; FIELD AB By relating scalar and vector couplings of the hyperons to the inferred empirical binding of the LAMBDA-hyperon in saturated nuclear matter, we obtain compatibility of this binding energy with neutron-star masses. Using the observational constraint on the lower bound on the maximum neutron-star mass and the upper bound of the couplings that are compatible with hypernuclear levels, we place bounds on the reduction in neutron-star mass that hyperons produce. For the best current estimate of nuclear-matter properties, the reduction in mass due to conversion of nucleons to hyperons is (0.71 +/- 0.15)M.. Neutrons comprise a slight majority population in neutron stars with mass approximately 1.5M.. C1 UNIV CALIF LOS ANGELES,LOS ANGELES,CA 90024. RP GLENDENNING, NK (reprint author), UNIV CALIF BERKELEY LAWRENCE BERKELEY LAB,DIV NUCL SCI,ONE CYCLOTRON RD,BERKELEY,CA 94720, USA. NR 25 TC 503 Z9 517 U1 0 U2 9 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 0031-9007 J9 PHYS REV LETT JI Phys. Rev. Lett. PD OCT 28 PY 1991 VL 67 IS 18 BP 2414 EP 2417 DI 10.1103/PhysRevLett.67.2414 PG 4 WC Physics, Multidisciplinary SC Physics GA GL801 UT WOS:A1991GL80100003 ER PT J AU ABE, F AF ABE, F TI MEASUREMENT OF THE E+E- INVARIANT-MASS DISTRIBUTION IN PBARP COLLISIONS AT SQUARE-ROOT S= 1.8 TEV SO PHYSICAL REVIEW LETTERS LA English DT Article ID PPBAR COLLISIONS; HIGH ENERGIES; GAUGE BOSONS; LEPTON AB We have measured the cross section as a function of invariant mass for isolated electron pairs produced in ppBAR collisions at square-root s = 1.8 TeV for pair masses M > 30 GeV/c2. We find good agreement between the measured distribution and the standard-model prediction for the Drell-Yan production mechanism. Additional heavy neutral vector bosons (Z') are excluded for M(Z') < 387 GeV/c2 (95% confidence level) assuming standard-model couplings. A lower limit of 2.2 TeV (95% confidence level) is placed on the electron-quark compositeness scale parameter LAMBDA-LLBAR associated with an effective contact interaction. RP ABE, F (reprint author), ARGONNE NATL LAB,ARGONNE,IL 60439, USA. NR 11 TC 26 Z9 26 U1 0 U2 0 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 0031-9007 J9 PHYS REV LETT JI Phys. Rev. Lett. PD OCT 28 PY 1991 VL 67 IS 18 BP 2418 EP 2422 DI 10.1103/PhysRevLett.67.2418 PG 5 WC Physics, Multidisciplinary SC Physics GA GL801 UT WOS:A1991GL80100004 ER PT J AU KLUGER, Y EISENBERG, JM SVETITSKY, B COOPER, F MOTTOLA, E AF KLUGER, Y EISENBERG, JM SVETITSKY, B COOPER, F MOTTOLA, E TI PAIR PRODUCTION IN A STRONG ELECTRIC-FIELD SO PHYSICAL REVIEW LETTERS LA English DT Article ID HEAVY-ION COLLISIONS; QUARK-GLUON PLASMA; FLUX-TUBE MODEL; PARTICLE-PRODUCTION; VACUUM AB We investigate the mechanism of pair creation in scalar QED from spatially homogeneous strong electric fields in 1 + 1 dimensions. Solution of the semiclassical field equations shows particle creation followed by plasma oscillations. We compare our results with a model based on a relativistic Boltzmann-Vlasov equation with a pair-creation source term related to the Schwinger mechanism. The time evolution of the electric field and the current obtained from the Boltzmann-Vlasov model is surprisingly similar to that found in the semiclassical calculation. C1 UNIV CALIF LOS ALAMOS SCI LAB,DIV THEORET,LOS ALAMOS,NM 87545. RP KLUGER, Y (reprint author), TEL AVIV UNIV,RAYMOND & BEVERLY SACKLER FAC EXACT SCI,SCH PHYS & ASTRON,IL-69978 TEL AVIV,ISRAEL. OI Svetitsky, Benjamin/0000-0001-5536-4707 NR 14 TC 184 Z9 185 U1 0 U2 0 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 0031-9007 J9 PHYS REV LETT JI Phys. Rev. Lett. PD OCT 28 PY 1991 VL 67 IS 18 BP 2427 EP 2430 DI 10.1103/PhysRevLett.67.2427 PG 4 WC Physics, Multidisciplinary SC Physics GA GL801 UT WOS:A1991GL80100006 ER PT J AU KRISHNAGOPAL, S SIEMANN, R AF KRISHNAGOPAL, S SIEMANN, R TI COHERENT BEAM-BEAM INTERACTIONS IN ELECTRON-POSITRON COLLIDERS SO PHYSICAL REVIEW LETTERS LA English DT Article ID SOLVABLE MODEL; RINGS AB We present the results of a new calculational technique that evaluates the beam-beam force due to an arbitrary charge distribution. We find coherent instabilities that dominate at certain operating points and depend strongly on the degree of damping in the system. We conclude that while these resonances may play a significant role for colliders with low damping, with a careful choice of operating points they are unlikely to present a danger to colliders with greater damping, such as the new generation of high-luminosity heavy-quark factories currently under design. C1 STANFORD UNIV,STANFORD LINEAR ACCELERATOR CTR,STANFORD,CA 94305. RP KRISHNAGOPAL, S (reprint author), UNIV CALIF BERKELEY LAWRENCE BERKELEY LAB,BERKELEY,CA 94720, USA. NR 14 TC 13 Z9 13 U1 0 U2 0 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 0031-9007 J9 PHYS REV LETT JI Phys. Rev. Lett. PD OCT 28 PY 1991 VL 67 IS 18 BP 2461 EP 2464 DI 10.1103/PhysRevLett.67.2461 PG 4 WC Physics, Multidisciplinary SC Physics GA GL801 UT WOS:A1991GL80100015 ER PT J AU ZHONG, F ECKE, R STEINBERG, V AF ZHONG, F ECKE, R STEINBERG, V TI ASYMMETRIC MODES AND THE TRANSITION TO VORTEX STRUCTURES IN ROTATING RAYLEIGH-BENARD CONVECTION SO PHYSICAL REVIEW LETTERS LA English DT Article ID STABILITY AB We report heat transport measurements and optical shadowgraph visualization of rotating Rayleigh-Benard convection. For dimensionless rotation rates 140 < OMEGA < 4300, the initial transition to convection, occurring at a Rayleigh number R much less than the linear-stability value for roll or vortex states, is a forward Hopf bifurcation to an azimuthally asymmetric state with mode number n. States with n = 3, 4, 5, 6, and 7 exist at low to moderate R and precess with frequencies that depend on R and OMEGA. At higher R there is a continuous transition to a state with noisy, time-dependent heat transport, a distinct array of vortices in the central region, and a modulation of the precession speed of the outer structures. C1 UNIV CALIF LOS ALAMOS SCI LAB,CTR NONLINEAR STUDIES,LOS ALAMOS,NM 87545. RP ZHONG, F (reprint author), UNIV CALIF LOS ALAMOS SCI LAB,DIV PHYS,LOS ALAMOS,NM 87545, USA. RI Steinberg, Victor/B-3205-2009; OI Ecke, Robert/0000-0001-7772-5876 NR 9 TC 70 Z9 70 U1 2 U2 7 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 0031-9007 J9 PHYS REV LETT JI Phys. Rev. Lett. PD OCT 28 PY 1991 VL 67 IS 18 BP 2473 EP 2476 DI 10.1103/PhysRevLett.67.2473 PG 4 WC Physics, Multidisciplinary SC Physics GA GL801 UT WOS:A1991GL80100018 ER PT J AU DRAKE, RP WILLIAMS, EA AF DRAKE, RP WILLIAMS, EA TI 3-WAVE PARAMETRIC AMPLIFICATION IN TIME-DEPENDENT MEDIA, WITH APPLICATION TO STIMULATED BRILLOUIN-SCATTERING SO PHYSICAL REVIEW LETTERS LA English DT Article ID 4-DIMENSIONAL EIKONAL THEORY; LINEAR-MODE CONVERSION; INHOMOGENEOUS PLASMAS; DRIFTING PLASMAS; INSTABILITIES; TOKAMAK AB A method is presented for evaluating the amplification of a three-wave parametric instability in a medium having a slow, locally linear variation in both time and space, and is applied to the specific case of stimulated Brillouin scattering (SBS) in a plasma undergoing an isothermal rarefaction. Time dependence can substantially alter the gain of such a parametric amplifier. For SBS in a subsonic rarefaction, inclusion of time dependence eliminates the absolute instability. RP DRAKE, RP (reprint author), UNIV CALIF LAWRENCE LIVERMORE NATL LAB,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 16 TC 10 Z9 10 U1 0 U2 1 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 0031-9007 J9 PHYS REV LETT JI Phys. Rev. Lett. PD OCT 28 PY 1991 VL 67 IS 18 BP 2477 EP 2480 DI 10.1103/PhysRevLett.67.2477 PG 4 WC Physics, Multidisciplinary SC Physics GA GL801 UT WOS:A1991GL80100019 ER PT J AU LOWE, W MACHARRIE, RA BEAN, JC PETICOLAS, L CLARKE, R DOSPASSOS, W BRIZARD, C RODRICKS, B AF LOWE, W MACHARRIE, RA BEAN, JC PETICOLAS, L CLARKE, R DOSPASSOS, W BRIZARD, C RODRICKS, B TI REAL-TIME X-RAY-DIFFRACTION OBSERVATION OF A PIN-SLIP MECHANISM IN GEXSI1-X STRAINED LAYERS SO PHYSICAL REVIEW LETTERS LA English DT Article ID EPITAXIAL MULTILAYERS; MISFIT DISLOCATIONS; DEFECTS; HETEROSTRUCTURES; RELAXATION AB Steplike behavior of the perpendicular lattice strain in GexSi1-x alloy layers, grown epitaxially on Si(001), is revealed by real-time x-ray scattering during rapid thermal annealing. A cooperative pin-slip mechanism is proposed which accounts for the observed kinetic effects including the coexistence of domains with different states of strain. C1 UNIV MICHIGAN,RANDALL LAB PHYS,ANN ARBOR,MI 48109. ARGONNE NATL LAB,DIV ADV PHOTON SOURCE,ARGONNE,IL 60439. RP LOWE, W (reprint author), AT&T BELL LABS,MURRAY HILL,NJ 07974, USA. NR 19 TC 7 Z9 7 U1 0 U2 4 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 0031-9007 J9 PHYS REV LETT JI Phys. Rev. Lett. PD OCT 28 PY 1991 VL 67 IS 18 BP 2513 EP 2516 DI 10.1103/PhysRevLett.67.2513 PG 4 WC Physics, Multidisciplinary SC Physics GA GL801 UT WOS:A1991GL80100028 ER PT J AU RUCKMAN, MW CHEN, J QIU, SL KUIPER, P STRONGIN, M DUNLAP, BI AF RUCKMAN, MW CHEN, J QIU, SL KUIPER, P STRONGIN, M DUNLAP, BI TI INTERPRETING THE NEAR EDGES OF O2 AND O2- IN ALKALI-METAL SUPEROXIDES SO PHYSICAL REVIEW LETTERS LA English DT Article ID N-2; O-2; NO AB Depositing alkali metal into a molecular oxygen layer dispersed on a Kr film produces alkali-metal superoxides containing the O2- species for photoemission and near-edge study. The oxygen K-edge spectrum of LiO2, KO2, and CsO2 is in good agreement with theoretical calculations for the free O2- ion. The O K edge for the superoxide strongly resembles that observed for O2 which is nondissociatively adsorbed on a metal surface. C1 USN,RES LAB,THEORET CHEM SECT,WASHINGTON,DC 20375. RP RUCKMAN, MW (reprint author), BROOKHAVEN NATL LAB,DEPT PHYS,UPTON,NY 11973, USA. RI Kuiper, Pieter/A-6806-2012; OI Dunlap, Brett/0000-0003-1356-6559 NR 19 TC 46 Z9 46 U1 0 U2 10 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 0031-9007 J9 PHYS REV LETT JI Phys. Rev. Lett. PD OCT 28 PY 1991 VL 67 IS 18 BP 2533 EP 2536 DI 10.1103/PhysRevLett.67.2533 PG 4 WC Physics, Multidisciplinary SC Physics GA GL801 UT WOS:A1991GL80100033 ER PT J AU TSEN, KT WALD, KR RUF, T YU, PY MORKOC, H AF TSEN, KT WALD, KR RUF, T YU, PY MORKOC, H TI ELECTRON-OPTICAL-PHONON INTERACTIONS IN ULTRATHIN GAAS/ALAS MULTIPLE QUANTUM-WELLS SO PHYSICAL REVIEW LETTERS LA English DT Article ID RAMAN-SCATTERING; CONFINED LO; GAAS; SUPERLATTICES AB Nonequilibrium populations of both confined and interface phonons generated by picosecond laser pulses in a series of GaAs/AlAs quantum wells have been studied by time-resolved picosecond Raman scattering as a function of well width. The dependence of the nonequilibrium phonon populations on well width is found to be sensitive to the theoretical model which is used to describe the electron-phonon interaction. Our data disagree with the macroscopic models of electron-phonon interaction, but they are in excellent agreement with the microscopic model proposed recently by Huang and Zhu. C1 UNIV CALIF BERKELEY,DEPT PHYS,BERKELEY,CA 94720. UNIV CALIF BERKELEY LAWRENCE BERKELEY LAB,DIV MAT SCI,BERKELEY,CA 94720. UNIV ILLINOIS,COORDINATED SCI LAB,URBANA,IL 61801. RP TSEN, KT (reprint author), ARIZONA STATE UNIV,DEPT PHYS,TEMPE,AZ 85287, USA. NR 15 TC 115 Z9 116 U1 0 U2 3 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 0031-9007 J9 PHYS REV LETT JI Phys. Rev. Lett. PD OCT 28 PY 1991 VL 67 IS 18 BP 2557 EP 2560 DI 10.1103/PhysRevLett.67.2557 PG 4 WC Physics, Multidisciplinary SC Physics GA GL801 UT WOS:A1991GL80100039 ER PT J AU TROHIDOU, KN BLACKMAN, JA COOKE, JF AF TROHIDOU, KN BLACKMAN, JA COOKE, JF TI CALCULATION OF THE HIGH-ENERGY SPIN-WAVE SPECTRUM OF HCP COBALT SO PHYSICAL REVIEW LETTERS LA English DT Article ID MAGNETIC EXCITATIONS; NICKEL; IRON AB The magnetic susceptibility of ferromagnetic hcp cobalt has been calculated based on itinerant-electron theory. For wave vectors along the c axis, well-defined acoustic and optic spin-wave excitations were found to exist out to the zone boundary. In the basal plane, spin waves were found to exist up to energies of about 300 meV before disappearing into the Stoner continuum. These spectra are considerably less complex than expected and are in broad agreement with preliminary neutron-scattering data. C1 UNIV READING,DEPT PHYS,READING RG6 2AF,BERKS,ENGLAND. OAK RIDGE NATL LAB,DIV SOLID STATE,OAK RIDGE,TN 37831. NR 13 TC 14 Z9 14 U1 0 U2 4 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 0031-9007 J9 PHYS REV LETT JI Phys. Rev. Lett. PD OCT 28 PY 1991 VL 67 IS 18 BP 2561 EP 2564 DI 10.1103/PhysRevLett.67.2561 PG 4 WC Physics, Multidisciplinary SC Physics GA GL801 UT WOS:A1991GL80100040 ER PT J AU ARNOLD, GB MUELLER, FM SWIHART, JC AF ARNOLD, GB MUELLER, FM SWIHART, JC TI ANGLE-RESOLVED PHOTOEMISSION AS A PROBE OF ALPHA-2-F IN HIGH-TEMPERATURE SUPERCONDUCTORS - A STUDY OF BI2SR2CACU2O8+DELTA SO PHYSICAL REVIEW LETTERS LA English DT Article ID HIGH-TC SUPERCONDUCTORS; SPECTROSCOPY AB The possibility of using temperature-dependent angle-resolved-photoemission data to derive an effective a2F for high-temperature superconductors via a Nambu-Eliashberg inversion is investigated. On analyzing data of Dessau et aL on Bi 2:2:1:2, we find a sharp bosonic peak at low energy (at approximately 10 meV). C1 UNIV CALIF LOS ALAMOS SCI LAB,CTR MAT SCI,LOS ALAMOS,NM 87545. INDIANA UNIV,DEPT PHYS,BLOOMINGTON,IN 47405. RP ARNOLD, GB (reprint author), UNIV NOTRE DAME,DEPT PHYS,NOTRE DAME,IN 46556, USA. NR 31 TC 42 Z9 42 U1 0 U2 1 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 0031-9007 J9 PHYS REV LETT JI Phys. Rev. Lett. PD OCT 28 PY 1991 VL 67 IS 18 BP 2569 EP 2572 DI 10.1103/PhysRevLett.67.2569 PG 4 WC Physics, Multidisciplinary SC Physics GA GL801 UT WOS:A1991GL80100042 ER PT J AU SCOVEL, C AF SCOVEL, C TI ON SYMPLECTIC LATTICE MAPS SO PHYSICS LETTERS A LA English DT Article ID INTEGRATION AB Symplectic lattice maps are lattice maps which can be thought of as the restriction of a symplectic map to an invariant lattice. I show how Ruth's method, the midpoint rule, and the generating function technique may be altered to determine symplectic lattice maps which approximate the flow map of a Hamiltonian system to arbitrarily high order. Consequently, symplectic lattice maps are a viable tool in the study of Hamiltonian systems. RP SCOVEL, C (reprint author), UNIV CALIF LOS ALAMOS SCI LAB,COMP RES GRP,C-3,MS-B265,LOS ALAMOS,NM 87545, USA. NR 18 TC 11 Z9 11 U1 0 U2 2 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0375-9601 J9 PHYS LETT A JI Phys. Lett. A PD OCT 28 PY 1991 VL 159 IS 8-9 BP 396 EP 400 DI 10.1016/0375-9601(91)90368-I PG 5 WC Physics, Multidisciplinary SC Physics GA GP047 UT WOS:A1991GP04700005 ER PT J AU CONNOLLY, JS AF CONNOLLY, JS TI PERSONNEL SHORTAGES SO SCIENTIST LA English DT Letter RP CONNOLLY, JS (reprint author), SOLAR ENERGY RES INST,PHOTOCONVERS RES BRANCH,GOLDEN,CO 80401, USA. NR 1 TC 0 Z9 0 U1 0 U2 0 PU SCIENTIST INC PI PHILADELPHIA PA 3600 MARKET ST SUITE 450, PHILADELPHIA, PA 19104 SN 0890-3670 J9 SCIENTIST JI Scientist PD OCT 28 PY 1991 VL 5 IS 21 BP 12 EP 12 PG 1 WC Information Science & Library Science; Multidisciplinary Sciences SC Information Science & Library Science; Science & Technology - Other Topics GA GL796 UT WOS:A1991GL79600014 ER PT J AU AMONETTE, JE SCOTT, AD AF AMONETTE, JE SCOTT, AD TI DETERMINATION OF FERROUS IRON IN NONREFRACTORY SILICATE MINERALS .1. AN IMPROVED SEMI-MICRO OXIDIMETRIC METHOD SO CHEMICAL GEOLOGY LA English DT Article AB Peters' oxidimetric vanadate method for the determination of Fe(II) in silicate minerals was investigated to see if improvements could be made in the accuracy, precision and speed of the analysis. Specific attention was given to the composition of the acid matrix used to dissolve the samples, incubation temperature and period, composition of the acid matrix during the titration step, titration endpoint indicator, calibration of Fe(II) standard, the manner of adding and quantifying the amounts of oxidimetric reagents, and potential interferences. As a result of the investigation, several improvements were made in the method, notably, sample dissolution at 60-degrees-C for 4 hr., gravimetric addition of redox reagents, a sharper titration endpoint, and use of the same container for the entire process. Application of the improved method to the analysis of Fe(II) in 5 geochemical reference samples (BCR-1, G-2, PCC-1, MICA-Fe and MICA-Mg) and 3 mica samples yielded very precise results (S.D. 0.01-0.04% FeO) and very good agreement with reference values. C1 IOWA STATE UNIV SCI & TECHNOL, DEPT AGRON, AMES, IA 50011 USA. RP AMONETTE, JE (reprint author), PACIFIC NW LAB, POB 999, RICHLAND, WA 99352 USA. NR 20 TC 6 Z9 6 U1 0 U2 2 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0009-2541 J9 CHEM GEOL JI Chem. Geol. PD OCT 25 PY 1991 VL 92 IS 4 BP 329 EP 338 DI 10.1016/0009-2541(91)90077-5 PG 10 WC Geochemistry & Geophysics SC Geochemistry & Geophysics GA GR974 UT WOS:A1991GR97400005 ER PT J AU VANLEEUWEN, C TOPS, C BREUKEL, C VANDERKLIFT, H DEAVEN, L FODDE, R KHAN, PM AF VANLEEUWEN, C TOPS, C BREUKEL, C VANDERKLIFT, H DEAVEN, L FODDE, R KHAN, PM TI CA REPEAT POLYMORPHISM WITHIN THE MCC (MUTATED IN COLORECTAL-CANCER) GENE SO NUCLEIC ACIDS RESEARCH LA English DT Note C1 LEIDEN UNIV,DEPT HUMAN GENET,2300 RA LEIDEN,NETHERLANDS. UNIV CALIF LOS ALAMOS SCI LAB,LOS ALAMOS,NM 87545. NR 2 TC 51 Z9 52 U1 0 U2 1 PU OXFORD UNIV PRESS UNITED KINGDOM PI OXFORD PA WALTON ST JOURNALS DEPT, OXFORD, ENGLAND OX2 6DP SN 0305-1048 J9 NUCLEIC ACIDS RES JI Nucleic Acids Res. PD OCT 25 PY 1991 VL 19 IS 20 BP 5805 EP 5805 DI 10.1093/nar/19.20.5805-a PG 1 WC Biochemistry & Molecular Biology SC Biochemistry & Molecular Biology GA GM698 UT WOS:A1991GM69800076 PM 1945868 ER PT J AU HUGHES, R AF HUGHES, R TI ATOMIC PHYSICS - ANTIHYDROGEN IN A NEW LIGHT SO NATURE LA English DT Editorial Material RP HUGHES, R (reprint author), UNIV CALIF LOS ALAMOS SCI LAB,DIV PHYS,LOS ALAMOS,NM 87545, USA. NR 7 TC 7 Z9 7 U1 0 U2 0 PU MACMILLAN MAGAZINES LTD PI LONDON PA 4 LITTLE ESSEX STREET, LONDON, ENGLAND WC2R 3LF SN 0028-0836 J9 NATURE JI Nature PD OCT 24 PY 1991 VL 353 IS 6346 BP 700 EP 701 DI 10.1038/353700d0 PG 2 WC Multidisciplinary Sciences SC Science & Technology - Other Topics GA GL696 UT WOS:A1991GL69600035 ER PT J AU RUSSO, JG AF RUSSO, JG TI CORRELATION-FUNCTIONS IN C-GREATER-THAN-25 NONCRITICAL STRING THEORIES SO PHYSICS LETTERS B LA English DT Article ID QUANTUM-GRAVITY; FIELD-THEORY; ALGEBRA; MODELS AB We compute three-point correlation functions in c > 25 noncritical strings by extending a recent approach by Goulian and Li. It is shown that only for special kinematic configurations they reduce to simple expressions. Then we discuss another approach in which the cosmological term is modified and introduced in perturbation theory. Unlike c < 1, where this prescription is basically equivalent to GL ansatz, for c > 25 it defines different theories. In particular, when c = 25 + 6(p-p')2/pp' the Liouville field takes values on a circle of radius R = square-root pp'/2 and it is consistent to truncate the spectrum to that of a minimal model. Some consequences of such an interpretation are discussed. C1 STANFORD UNIV,STANFORD LINEAR ACCELERATOR CTR,STANFORD,CA 94305. RP RUSSO, JG (reprint author), STANFORD UNIV,THEORY GRP,STANFORD,CA 94305, USA. OI Russo, Jorge Guillermo/0000-0002-3023-1833 NR 20 TC 0 Z9 0 U1 0 U2 0 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0370-2693 J9 PHYS LETT B JI Phys. Lett. B PD OCT 24 PY 1991 VL 269 IS 1-2 BP 91 EP 95 DI 10.1016/0370-2693(91)91457-7 PG 5 WC Astronomy & Astrophysics; Physics, Nuclear; Physics, Particles & Fields SC Astronomy & Astrophysics; Physics GA GN329 UT WOS:A1991GN32900017 ER PT J AU THOMA, MH AF THOMA, MH TI VISCOSITY COEFFICIENT OF THE QUARK GLUON PLASMA IN THE WEAK-COUPLING LIMIT SO PHYSICS LETTERS B LA English DT Article ID HOT GAUGE-THEORIES; TRANSPORT-COEFFICIENTS; QCD; TEMPERATURE; AMPLITUDES AB The shear viscosity coefficient of the quark-gluon plasma is calculated by considering the relaxation time approximation. Screening effects are taken into account by using an effective perturbation theory developed recently for the finite temperature QCD in the weak coupling limit. The result agrees with the one obtained from a variational approach to the Boltzmann equation, but is at variance to other results based on a Kubo-type formula. RP THOMA, MH (reprint author), UNIV CALIF BERKELEY,LAWRENCE BERKELEY LAB,DIV NUCL SCI,BERKELEY,CA 94720, USA. NR 26 TC 49 Z9 49 U1 1 U2 1 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0370-2693 J9 PHYS LETT B JI Phys. Lett. B PD OCT 24 PY 1991 VL 269 IS 1-2 BP 144 EP 148 DI 10.1016/0370-2693(91)91466-9 PG 5 WC Astronomy & Astrophysics; Physics, Nuclear; Physics, Particles & Fields SC Astronomy & Astrophysics; Physics GA GN329 UT WOS:A1991GN32900026 ER PT J AU THOMSON, MA COBB, JH ALLISON, WWM ALNER, GJ AMBATS, I AYRES, DS BALKA, LJ BARR, GD BARRETT, WL BENJAMIN, D BORDER, PM BROOKS, CB COCKERILL, DJA COURANT, H DAWSON, JW EDWARDS, VW EWEN, B FIELDS, TH GARCIAGARCIA, C GILES, RH GILLER, GL GOODMAN, MC GRAY, RN HEPPELMANN, S HILL, N HOFTIEZER, JH JANKOWSKI, DJ JOHNS, K JOYCE, T KAFKA, T KASAHARA, SMS KIRBYGALLAGHER, LM KOCHOCKI, J LITCHFIELD, PJ LONGLEY, NP LOPEZ, FV LOWE, MJ MANN, WA MARSHAK, ML MAY, EN MCMASTER, L MILBURN, R MILLER, WH MINOR, CP NAPIER, A OLIVER, W PEARCE, GF PERKINS, DH PETERSON, EA PRICE, LE ROBACK, DM ROSEN, DB RUDDICK, K SAITTA, B SCHMID, DJ SCHLERETH, J SCHNEPS, J SHIELD, PD SHUPE, MA SUNDARALINGAM, N THRON, JL URETSKY, JL WERKEMA, SJ WEST, N WOODS, CA AF THOMSON, MA COBB, JH ALLISON, WWM ALNER, GJ AMBATS, I AYRES, DS BALKA, LJ BARR, GD BARRETT, WL BENJAMIN, D BORDER, PM BROOKS, CB COCKERILL, DJA COURANT, H DAWSON, JW EDWARDS, VW EWEN, B FIELDS, TH GARCIAGARCIA, C GILES, RH GILLER, GL GOODMAN, MC GRAY, RN HEPPELMANN, S HILL, N HOFTIEZER, JH JANKOWSKI, DJ JOHNS, K JOYCE, T KAFKA, T KASAHARA, SMS KIRBYGALLAGHER, LM KOCHOCKI, J LITCHFIELD, PJ LONGLEY, NP LOPEZ, FV LOWE, MJ MANN, WA MARSHAK, ML MAY, EN MCMASTER, L MILBURN, R MILLER, WH MINOR, CP NAPIER, A OLIVER, W PEARCE, GF PERKINS, DH PETERSON, EA PRICE, LE ROBACK, DM ROSEN, DB RUDDICK, K SAITTA, B SCHMID, DJ SCHLERETH, J SCHNEPS, J SHIELD, PD SHUPE, MA SUNDARALINGAM, N THRON, JL URETSKY, JL WERKEMA, SJ WEST, N WOODS, CA TI THE OBSERVATION OF UNDERGROUND MUONS FROM THE DIRECTION OF CYGNUS-X-3 DURING THE JANUARY 1991 RADIO FLARE SO PHYSICS LETTERS B LA English DT Article ID PROPORTIONAL-TUBE ARRAY; SEARCH; FLUX AB Muons recorded in the Soudan 2 underground nucleon decay detector from January 1989 to February 1991 have been examined for any correlation with the radio flares of Cygnus X-3 observed during this period. On two nearby days during the radio flare of January 1991 a total of 32 muons within 2.0-degrees of the Cygnus X-3 direction were observed when 11.4 were expected. C1 RUTHERFORD APPLETON LAB,DIDCOT OX11 0QX,OXON,ENGLAND. ARGONNE NATL LAB,ARGONNE,IL 60439. TUFTS UNIV,MEDFORD,MA 02155. UNIV MINNESOTA,MINNEAPOLIS,MN 55455. RP THOMSON, MA (reprint author), UNIV OXFORD,DEPT PHYS,OXFORD OX1 3RH,ENGLAND. NR 27 TC 11 Z9 11 U1 0 U2 0 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0370-2693 J9 PHYS LETT B JI Phys. Lett. B PD OCT 24 PY 1991 VL 269 IS 1-2 BP 220 EP 226 DI 10.1016/0370-2693(91)91478-E PG 7 WC Astronomy & Astrophysics; Physics, Nuclear; Physics, Particles & Fields SC Astronomy & Astrophysics; Physics GA GN329 UT WOS:A1991GN32900038 ER PT J AU FULTON, JL YEE, GG SMITH, RD AF FULTON, JL YEE, GG SMITH, RD TI HYDROGEN-BONDING OF METHYL ALCOHOL-D IN SUPERCRITICAL CARBON-DIOXIDE AND SUPERCRITICAL ETHANE SOLUTIONS SO JOURNAL OF THE AMERICAN CHEMICAL SOCIETY LA English DT Article ID PHASE-BEHAVIOR; METHANOL DIMER; ASSOCIATION; FLUIDS; NITROGEN; TEMPERATURE; ISOBUTANE; SOLVENTS; ABINITIO; MATRICES AB Fourier transform infrared (FTIR) spectroscopy has been used to measure the degree of intermolecular hydrogen bonding between solute molecules of methyl alcohol-d in supercritical carbon dioxide, supercritical ethane, and liquid heptane. In these fluids, an equilibrium is established between the free non-hydrogen-bonded monomer and the various hydrogen-bonded species of which the tetrameric species is believed to predominate. The fluid pressure, temperature, and the alcohol concentration significantly affect the equilibrium distribution of the monomer and oligomeric species. Both supercritical and subcritical binary solutions containing up to 0.07 mole fraction of methyl alcohol-d were examined under conditions ranging from 30 to 400 bar and 40 to 80-degrees-C. The changes in the partial molar enthalpies and partial molar volumes of the alcohol upon hydrogen bonding are reported. These measurements, together with evidence from coupled rotational-vibrational bands, point to the formation of some type of weak complex between carbon dioxide and methyl alcohol. Such a complex is likely the result of the interaction of the large carbon dioxide quadrupole with the methyl alcohol dipole. The solvation phenomena presented in this paper will provide for more complete thermodynamic treatments of these systems. C1 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 47 TC 127 Z9 128 U1 1 U2 7 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 SN 0002-7863 J9 J AM CHEM SOC JI J. Am. Chem. Soc. PD OCT 23 PY 1991 VL 113 IS 22 BP 8327 EP 8334 DI 10.1021/ja00022a019 PG 8 WC Chemistry, Multidisciplinary SC Chemistry GA GM038 UT WOS:A1991GM03800019 ER PT J AU LEMKE, FR SZALDA, DJ BULLOCK, RM AF LEMKE, FR SZALDA, DJ BULLOCK, RM TI RUTHENIUM ZIRCONIUM COMPLEXES CONTAINING C2 BRIDGES WITH BOND ORDERS OF 3, 2, AND 1 - SYNTHESIS AND STRUCTURES OF CP(PME3)2RUCHNCHNZRCLCP2 (N = 0, 1, 2) SO JOURNAL OF THE AMERICAN CHEMICAL SOCIETY LA English DT Article ID TRANSITION-METAL COMPLEXES; AGOSTIC ALKENYLZIRCONOCENE COMPLEXES; CYCLOPENTADIENYL-OSMIUM CHEMISTRY; ORGANOMETALLIC LEWIS-ACIDS; MU-METHYLENE COMPLEXES; X-RAY STRUCTURE; INSERTION REACTIONS; RHENIUM CARBONYLS; HETEROBIMETALLIC COMPLEX; ACTIVATED ACETYLENES AB A series of Ru/Zr complexes linked by C2 bridges of bond orders 3, 2, and 1 were prepared, and characterized by spectroscopic data and single-crystal X-ray diffraction. The dimetalloalkyne complex Cp(PMe3)2RuC = CZrClCp2 was prepared by the reaction of Cp(PMe3)2RuC = CH with either Cp2Zr(CH3)Cl or Cp2Zr(NMe2)Cl. This dimetalloalkyne is the first example of a structurally characterized alkyne that is substituted by an electron-rich metal at one end, and by an electron-deficient metal at the other. The reaction of Cp(PMe3)2RuC = CH with [Cp2Zr(H)Cl]n gives the dimetalloalkene complex Cp(PMe3)2RuCH = CHZrClCp2, which has a three-center, two-electron agostic interaction between the Zr and the vinylic CH that is beta to Zr. Carbonylation of Cp(PMe3)2RuCH = CHZrClCp2 with 1 atm of CO produces the eta-2-acyl complex Cp(PMe3)2RuCH = CHC(O)ZrClCp2. Analysis of the spectroscopic and structural data for this acyl compound indicates a substantial contribution from a zwitterionic resonance form that has a formal positive charge at Ru and a negative charge on the Zr portion. Hydrolysis of Cp(PMe3)2RuCH = CHZrClCp2 produces the known zirconium complex [Cp2ZrCl]2O and the ruthenium vinyl complex Cp(PMe3)2RuCH = CH2. Reaction of [Cp2Zr(H)Cl]n with Cp(PMe3)2RuCH = CH2 gives the dimetalloalkane complex Cp(PMe3)2RuCH2CH2ZrClCp2. Spectroscopic and crystallographic data are interpreted to indicate that this compound also has an agostic interaction between the Zr and a CH adjacent to Ru. C1 BROOKHAVEN NATL LAB, DEPT CHEM, UPTON, NY 11973 USA. RI Bullock, R. Morris/L-6802-2016 OI Bullock, R. Morris/0000-0001-6306-4851 NR 90 TC 132 Z9 132 U1 0 U2 5 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 0002-7863 J9 J AM CHEM SOC JI J. Am. Chem. Soc. PD OCT 23 PY 1991 VL 113 IS 22 BP 8466 EP 8477 DI 10.1021/ja00022a039 PG 12 WC Chemistry, Multidisciplinary SC Chemistry GA GM038 UT WOS:A1991GM03800039 ER PT J AU SUN, L THOMAS, RC CROOKS, RM RICCO, AJ AF SUN, L THOMAS, RC CROOKS, RM RICCO, AJ TI REAL-TIME ANALYSIS OF CHEMICAL-REACTIONS OCCURRING AT A SURFACE-CONFINED ORGANIC MONOLAYER SO JOURNAL OF THE AMERICAN CHEMICAL SOCIETY LA English DT Note ID LANGMUIR-BLODGETT MONOLAYERS; SELF-ASSEMBLING MONOLAYERS; ADSORBED MONOLAYERS; GOLD SURFACES; FILMS; MULTILAYERS; ADSORPTION; IR; ELLIPSOMETRY; SPECTROSCOPY C1 UNIV NEW MEXICO,DEPT CHEM,ALBUQUERQUE,NM 87131. UNIV NEW MEXICO,CTR HIGH TECHNOL MAT,ALBUQUERQUE,NM 87131. SANDIA NATL LABS,DIV MICROSENSOR 1163,ALBUQUERQUE,NM 87185. RI Ricco, Antonio/A-5273-2010; OI Ricco, Antonio/0000-0002-2355-4984 NR 19 TC 65 Z9 65 U1 1 U2 6 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 SN 0002-7863 J9 J AM CHEM SOC JI J. Am. Chem. Soc. PD OCT 23 PY 1991 VL 113 IS 22 BP 8550 EP 8552 DI 10.1021/ja00022a068 PG 3 WC Chemistry, Multidisciplinary SC Chemistry GA GM038 UT WOS:A1991GM03800068 ER PT J AU HIGASHI, M YAMAMURA, N ABE, T BURNS, TP AF HIGASHI, M YAMAMURA, N ABE, T BURNS, TP TI WHY DONT ALL TERMITE SPECIES HAVE A STERILE WORKER CASTE SO PROCEEDINGS OF THE ROYAL SOCIETY B-BIOLOGICAL SCIENCES LA English DT Article ID EVOLUTION AB No general theory explains why a sterile worker caste is not found in all species of both Hymenoptera and Isoptera (Insecta). Recent empirical findings show that, in the termites (Isoptera), feeding outside the nest correlates well with the evolution of the sterile (true) worker caste from the non-sterile (false) worker caste. Here we explain the connection between food-nest separation and true worker evolution in termites, providing a general theory on the restricted distribution of the sterile worker caste in the Isoptera. A cost-benefit model suggests that there is a critical level of nest stability above which natural selection favours true workers over false workers, irrespective of genetical relatedness. Because food-nest separation tends to increase nest stability, this theoretical result implies that the less a termite species consumes its nest as food, the more likely is its nest stability to fall above the critical level and a true worker caste will evolve. C1 SAGA MED SCH, DEPT NAT SCI, NABESHIMA, SAGA 849, JAPAN. KYOTO UNIV, CTR ECOL RES, SHIMOSAKAMOTO, OTSU 52001, JAPAN. OAK RIDGE NATL LAB, DIV ENVIRONM SCI, OAK RIDGE, TN 37831 USA. RP HIGASHI, M (reprint author), RYUKOKU UNIV, FAC SCI & TECHNOL, SETA, OTSU 52021, JAPAN. NR 7 TC 35 Z9 36 U1 0 U2 1 PU ROYAL SOC PI LONDON PA 6-9 CARLTON HOUSE TERRACE, LONDON SW1Y 5AG, ENGLAND SN 0962-8452 J9 P ROY SOC B-BIOL SCI JI Proc. R. Soc. B-Biol. Sci. PD OCT 22 PY 1991 VL 246 IS 1315 BP 25 EP 29 DI 10.1098/rspb.1991.0120 PG 5 WC Biology; Ecology; Evolutionary Biology SC Life Sciences & Biomedicine - Other Topics; Environmental Sciences & Ecology; Evolutionary Biology GA GM267 UT WOS:A1991GM26700004 PM 1684665 ER PT J AU SIMS, KWW GLADNEY, ES AF SIMS, KWW GLADNEY, ES TI DETERMINATION OF ARSENIC, ANTIMONY, TUNGSTEN AND MOLYBDENUM IN SILICATE MATERIALS BY EPITHERMAL NEUTRON-ACTIVATION AND INORGANIC-ION EXCHANGE SO ANALYTICA CHIMICA ACTA LA English DT Article DE ACTIVATION ANALYSIS; ION EXCHANGE; ANTIMONY; ARSENIC; GEOLOGICAL MATERIALS; MOLYBDENUM; ROCKS; SILICATES; TUNGSTEN ID ATOMIC-ABSORPTION SPECTROMETRY; SELENIUM; ROCKS; FLAME AB Ion exchange on alumina columns was used to determine As, Sb, W and Mo in silicate rock samples. This procedure requires hour-long epithermal neutron irradiations, rapid ion exchange after the rocks have been brought into solution with sodium hydroxide, sodium peroxide fusion and short gamma-ray counts on an intrinsic Ge detector. With this technique the detection limits achieved were 5 ng g-1 for As, 10 ng g-1 for Sb and W and 50 ng g-1 for Mo. C1 UNIV CALIF LOS ALAMOS SCI LAB,HLTH & ENVIRONM CHEM GRP,LOS ALAMOS,NM 87545. NR 26 TC 17 Z9 18 U1 0 U2 4 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0003-2670 J9 ANAL CHIM ACTA JI Anal. Chim. Acta PD OCT 21 PY 1991 VL 251 IS 1-2 BP 297 EP 303 DI 10.1016/0003-2670(91)87150-6 PG 7 WC Chemistry, Analytical SC Chemistry GA GN416 UT WOS:A1991GN41600043 ER PT J AU BARBOUR, JC DIMOS, D GUILINGER, TR KELLY, MJ TSAO, SS AF BARBOUR, JC DIMOS, D GUILINGER, TR KELLY, MJ TSAO, SS TI ION-IRRADIATION CONTROL OF PHOTOLUMINESCENCE FROM POROUS SILICON SO APPLIED PHYSICS LETTERS LA English DT Article ID QUANTUM AB Ion irradiation was used to pattern a region of red-light emitting porous silicon by eliminating visible-light photoluminescence (PL). The PL peak wavelength is approximately 735 nm and shows little dependence on the excitation-light wavelength. The ratio of PL intensities for different excitation wavelengths was shown to be proportional to the ratio of the absorption coefficients. Below saturation, the integrated PL intensity increased linearly with excitation-light power density. RP BARBOUR, JC (reprint author), SANDIA NATL LABS,ALBUQUERQUE,NM 87185, USA. NR 12 TC 36 Z9 36 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 OCT 21 PY 1991 VL 59 IS 17 BP 2088 EP 2090 DI 10.1063/1.106141 PG 3 WC Physics, Applied SC Physics GA GK727 UT WOS:A1991GK72700008 ER PT J AU LUCAS, CA NGUYEN, TD KORTRIGHT, JB AF LUCAS, CA NGUYEN, TD KORTRIGHT, JB TI X-RAY REFLECTIVITY MEASUREMENTS OF THE EXPANSION OF CARBON-FILMS UPON ANNEALING SO APPLIED PHYSICS LETTERS LA English DT Article ID AMORPHOUS-CARBON; THIN-FILMS; MULTILAYERS; DIFFRACTION; SCATTERING; OVERCOATS; SURFACES; MEDIA; W/C AB Measurements have been made of the x-ray reflectivity from ultrathin, amorphous carbon films both before and after annealing. Analysis of the x-ray results indicates that annealing causes an increase in film thickness with a corresponding decrease in density. Such behavior is uncharacteristic of amorphous thin films and is interpreted as being due to changes in the interatomic bonding associated with transition to a more graphitic microstructure. RP LUCAS, CA (reprint author), UNIV CALIF BERKELEY LAWRENCE BERKELEY LAB,CTR ADV MAT,BERKELEY,CA 94720, USA. OI Lucas, Christopher/0000-0001-5743-3868 NR 25 TC 42 Z9 42 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 OCT 21 PY 1991 VL 59 IS 17 BP 2100 EP 2102 DI 10.1063/1.106093 PG 3 WC Physics, Applied SC Physics GA GK727 UT WOS:A1991GK72700012 ER PT J AU LAPIANOSMITH, DA EKLUND, EA HIMPSEL, FJ TERMINELLO, LJ AF LAPIANOSMITH, DA EKLUND, EA HIMPSEL, FJ TERMINELLO, LJ TI EPITAXY OF LIF ON GE(100) SO APPLIED PHYSICS LETTERS LA English DT Article ID PHOTOEMISSION; EXCITON; STATES; FILMS AB It is shown that LiF(100) films with the electronic properties of cleaved bulk LiF crystals can be grown epitaxially on Ge(100). These include an exceptionally large, negative electron affinity of -2.7 eV, which leads to intense photoemission at zero kinetic energy. The valence band offset ranges from 7.3-7.6 eV. C1 UNIV CALIF LAWRENCE LIVERMORE NATL LAB, LIVERMORE, CA 94550 USA. BROOKHAVEN NATL LAB, NATL SYNCHROTRON LIGHT SOURCE, UPTON, NY 11973 USA. RP LAPIANOSMITH, DA (reprint author), IBM CORP, THOMAS J WATSON RES CTR, DIV RES, POB 218, YORKTOWN HTS, NY 10598 USA. NR 18 TC 65 Z9 65 U1 0 U2 1 PU AMER INST PHYSICS PI WOODBURY PA CIRCULATION FULFILLMENT DIV, 500 SUNNYSIDE BLVD, WOODBURY, NY 11797-2999 SN 0003-6951 J9 APPL PHYS LETT JI Appl. Phys. Lett. PD OCT 21 PY 1991 VL 59 IS 17 BP 2174 EP 2176 DI 10.1063/1.106091 PG 3 WC Physics, Applied SC Physics GA GK727 UT WOS:A1991GK72700037 ER PT J AU FISHMAN, RS LIU, SH AF FISHMAN, RS LIU, SH TI COUPLING BETWEEN LONGITUDINAL AND TRANSVERSE FLUCTUATIONS IN A HEISENBERG-FERROMAGNET SO JOURNAL OF PHYSICS-CONDENSED MATTER LA English DT Article AB The coupling between the longitudinal and transverse fluctuations in a spin s ferromagnet becomes significant above a crossover temperature TBAR almost-equal-to T(C)/s. This coupling produces a splitting of the spin-wave resonance near the energy zJs, where z is the coordination number and J the coupling constant. We calculate the transverse mode frequencies and propose an experiment to detect the longitudinal fluctuations. RP FISHMAN, RS (reprint author), OAK RIDGE NATL LAB,DIV SOLID STATE,POB 2008,OAK RIDGE,TN 37831, USA. RI Fishman, Randy/C-8639-2013 NR 14 TC 2 Z9 2 U1 0 U2 1 PU IOP PUBLISHING LTD PI BRISTOL PA TECHNO HOUSE, REDCLIFFE WAY, BRISTOL, ENGLAND BS1 6NX SN 0953-8984 J9 J PHYS-CONDENS MAT JI J. Phys.-Condes. Matter PD OCT 21 PY 1991 VL 3 IS 42 BP 8313 EP 8318 DI 10.1088/0953-8984/3/42/026 PG 6 WC Physics, Condensed Matter SC Physics GA GM247 UT WOS:A1991GM24700027 ER PT J AU CHEN, SH CHANG, SL STREY, R THIYAGARAJAN, P AF CHEN, SH CHANG, SL STREY, R THIYAGARAJAN, P TI SMALL-ANGLE NEUTRON-SCATTERING INVESTIGATION OF STRUCTURAL INVERSION IN A 3-COMPONENT IONIC MICROEMULSION SO JOURNAL OF PHYSICS-CONDENSED MATTER LA English DT Article ID DILUTE SURFACTANT SOLUTIONS; LIQUID-CRYSTALLINE PHASES; NONPOLAR-SOLVENTS; GENERAL PATTERNS; FLUID MEMBRANES; BEHAVIOR; MIXTURES; SYSTEMS; L3; ELECTROLYTES AB We have made an extensive investigation of the phase diagrams and the associated micro-structure of a pseudo-ternary system AOT/water (0.6 wt% NaCl)/decane. This micro-emulsion system shows, for a surfactant concentration in excess of 6 wt%, a characteristic phase progression from a water-in-oil (W/O) micro-emulsion in coexistence with excess water at low temperatures to an oil-in-water (O/W) micro-emulsion in coexistence with excess oil at high temperatures through a one-phase micro-emulsion in the intermediate temperatures. Thus, one expects a structural inversion to occur somewhere in the one-phase channel. We have performed extensive small angle neutron scattering (SANS) measurements to study the pathway of such a structural inversion in this micro-emulsion system when there are comparable amounts of oil and water in the system, and when the volume fraction of water is much higher than that of oil. In the former case, we observed the inversion of the W/O to the O/W micro-emulsions through an intermediate bicontinuous one-phase micro-emulsion. In the latter case, we show that the inversion takes place through a pathway of L3-L-alpha-L1 as temperature increases. Particular emphasis is put on analyses of the interfacial structure in different micro-emulsion phases. C1 MIT,CTR MAT SCI & ENGN,CAMBRIDGE,MA 02139. MAX PLANCK INST BIOPHYS CHEM,W-3400 GOTTINGEN,GERMANY. ARGONNE NATL LAB,INTENSE PULSED NEUTRON SOURCE,ARGONNE,IL 60439. RP CHEN, SH (reprint author), MIT,DEPT NUCL ENGN,CAMBRIDGE,MA 02139, USA. NR 31 TC 13 Z9 13 U1 1 U2 9 PU IOP PUBLISHING LTD PI BRISTOL PA TECHNO HOUSE, REDCLIFFE WAY, BRISTOL, ENGLAND BS1 6NX SN 0953-8984 J9 J PHYS-CONDENS MAT JI J. Phys.-Condes. Matter PD OCT 21 PY 1991 VL 3 IS 42 BP F91 EP F107 DI 10.1088/0953-8984/3/42/009 PG 17 WC Physics, Condensed Matter SC Physics GA GM247 UT WOS:A1991GM24700010 ER PT J AU MJOLSNESS, E SHARP, DH REINITZ, J AF MJOLSNESS, E SHARP, DH REINITZ, J TI A CONNECTIONIST MODEL OF DEVELOPMENT SO JOURNAL OF THEORETICAL BIOLOGY LA English DT Article ID DROSOPHILA EMBRYO; GENE-EXPRESSION; GAP GENES; SEGMENTATION; PATTERN; EMBRYOGENESIS C1 UNIV CALIF LOS ALAMOS SCI LAB,DIV THEORET,LOS ALAMOS,NM 87545. COLUMBIA UNIV,DEPT BIOL SCI,NEW YORK,NY 10027. YALE UNIV,SCH MED,CTR MED INFORMAT,DEPT ANESTHESIOL,NEW HAVEN,CT 06510. RP MJOLSNESS, E (reprint author), YALE UNIV,DEPT COMP SCI,POB 2158 YALE STN,NEW HAVEN,CT 06520, USA. FU NLM NIH HHS [5-T15-LM07056] NR 26 TC 221 Z9 233 U1 1 U2 7 PU ACADEMIC PRESS LTD PI LONDON PA 24-28 OVAL RD, LONDON, ENGLAND NW1 7DX SN 0022-5193 J9 J THEOR BIOL JI J. Theor. Biol. PD OCT 21 PY 1991 VL 152 IS 4 BP 429 EP 453 DI 10.1016/S0022-5193(05)80391-1 PG 25 WC Biology; Mathematical & Computational Biology SC Life Sciences & Biomedicine - Other Topics; Mathematical & Computational Biology GA GN175 UT WOS:A1991GN17500001 PM 1758194 ER PT J AU WU, CY CLINE, D VOGT, EG KERNAN, WJ CZOSNYKA, T HELMER, KG IBBOTSON, RW KAVKA, AE KOTLINSKI, B DIAMOND, RM AF WU, CY CLINE, D VOGT, EG KERNAN, WJ CZOSNYKA, T HELMER, KG IBBOTSON, RW KAVKA, AE KOTLINSKI, B DIAMOND, RM TI ELECTROMAGNETIC PROPERTIES OF TUNGSTEN NUCLEI SO NUCLEAR PHYSICS A LA English DT Article DE W-182,W-184(NI-58, NI-58'), E = 235 MEV; W-182,W-184(XE-136, XE-136'), E = 561 MEV; MEASURED E-GAMMA, I-GAMMA FOLLOWING COULOMB EXCITATION; W-182,W-184(NI-58, NI-58'), E = 245 MEV; MEASURED E-GAMMA, I-GAMMA, RECOIL DISTANCE METHOD; W-182,W-184 DEDUCED LEVELS, E2 STATIC, TRANSITION MATRIX ELEMENTS, T1/2 ID 2ND 2+ STATE; COULOMB-EXCITATION; REORIENTATION MEASUREMENTS; QUADRUPOLE-MOMENT; ISOTOPES; W-184,186; W-182 AB Quadrupole collectivity in W-182, W-184 has been studied by Coulomb excitation with Ni-58 and Xe-136 projectiles. The yields of the de-excitation gamma-rays, measured in coincidence with the scattered ions, were used to determine a fairly complete set of electromagnetic matrix elements for the low-lying states. A separate experiment measured lifetimes for five and eight states respectively in W-182 and W-184 by the recoil distance method following Coulomb excitation with a 245 MeV Ni-58 projectile. These lifetime measurements are in good agreement with the results for the Coulomb excitation yield measurements. The correlations of the extracted E2 matrix elements are examined using the Cline-Flaum sum-rule technique and discussed in the framework of the various collective models. These correlations are well described with quadrupole shape degrees of freedom. Strong mixing between the beta- and gamma-vibration degrees of freedom, claimed in the pairing-plus-quadrupole model of Kumar and Baranger, is not supported by the present results. C1 UNIV CALIF BERKELEY,LAWRENCE BERKELEY LAB,DIV NUCL SCI,BERKELEY,CA 94720. RP WU, CY (reprint author), UNIV ROCHESTER,NUCL STRUCT RES LAB,ROCHESTER,NY 14627, USA. NR 33 TC 22 Z9 22 U1 0 U2 1 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0375-9474 J9 NUCL PHYS A JI Nucl. Phys. A PD OCT 21 PY 1991 VL 533 IS 2 BP 359 EP 380 DI 10.1016/0375-9474(91)90495-R PG 22 WC Physics, Nuclear SC Physics GA GM769 UT WOS:A1991GM76900010 ER PT J AU GLEISER, M KOLB, EW WATKINS, R AF GLEISER, M KOLB, EW WATKINS, R TI PHASE-TRANSITIONS WITH SUBCRITICAL BUBBLES SO NUCLEAR PHYSICS B LA English DT Article ID EARLY UNIVERSE; INFLATIONARY UNIVERSE; FINITE TEMPERATURE; ELECTROWEAK THEORY; SYMMETRY-BREAKING; BARYON ASYMMETRY; FALSE VACUUM; DOMAIN-WALLS; HIGGS-BOSON; COSMOLOGY AB We study the dynamics of cosmological phase transitions initiated from a state of thermal equilibrium. If the effective potential satisfies certain general conditions, a homogeneous phase of false vacuum will form as the Universe expands, and the transition will proceed by well-known bubble nucleation processes. If such conditions do not hold, the Universe may instead be filled with a two-phase emulsion. The evolution of the transition will be determined by the free energy difference between the two phases and by the expansion rate of the Universe. Thermal fluctuations between the phases will determine the final distribution of regions of the Universe in each phase as they freeze out. We develop a method to study the dynamics of such fluctuations, which we call sub-critical bubbles, and apply it to several situations of interest, including the symmetric and asymmetric double-well, and the Coleman-Weinberg scalar potentials. We show that in certain cases it is possible to avoid supercooling, with the transition being completed by sub-critical fluctuations. Possible applications to the electroweak phase transition are briefly discussed. C1 UNIV CALIF SANTA BARBARA,INST THEORET PHYS,SANTA BARBARA,CA 93106. FERMI NATL ACCELERATOR LAB,NASA,FERMILAB ASTROPHYS CTR,BATAVIA,IL 60510. UNIV CHICAGO,ENRICO FERMI INST,DEPT ASTRON & ASTROPHYS,CHICAGO,IL 60637. NR 63 TC 73 Z9 73 U1 0 U2 1 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0550-3213 J9 NUCL PHYS B JI Nucl. Phys. B PD OCT 21 PY 1991 VL 364 IS 2 BP 411 EP 450 DI 10.1016/0550-3213(91)90592-L PG 40 WC Physics, Particles & Fields SC Physics GA GL798 UT WOS:A1991GL79800008 ER PT J AU BAGGER, J DAWSON, S VALENCIA, G AF BAGGER, J DAWSON, S VALENCIA, G TI TESTING ELECTROWEAK SYMMETRY-BREAKING THROUGH GLUON FUSION AT RHO-RHO-COLLIDERS SO PHYSICAL REVIEW LETTERS LA English DT Article AB We use chiral Lagrangians to study the nonresonant production of longitudinally polarized vector bosons through gluon fusion at pp colliders. We compute the contributions induced by loops of colored pseudo Goldstone bosons and colored fermions. We find that the resulting cross sections potentially dominate the standard-model predictions and provide an important probe of the electroweak-symmetry-breaking sector. C1 BROOKHAVEN NATL LAB,DEPT PHYS,UPTON,NY 11973. CERN,DIV THEORY,CH-1211 GENEVA 23,SWITZERLAND. RP BAGGER, J (reprint author), JOHNS HOPKINS UNIV,DEPT PHYS & ASTRON,BALTIMORE,MD 21218, USA. NR 13 TC 24 Z9 24 U1 0 U2 0 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 0031-9007 J9 PHYS REV LETT JI Phys. Rev. Lett. PD OCT 21 PY 1991 VL 67 IS 17 BP 2256 EP 2259 DI 10.1103/PhysRevLett.67.2256 PG 4 WC Physics, Multidisciplinary SC Physics GA GK725 UT WOS:A1991GK72500005 ER PT J AU ZHU, D DOVER, CB GAL, A MAY, M AF ZHU, D DOVER, CB GAL, A MAY, M TI FORMATION OF LAMBDA-LAMBDA-HYPERNUCLEI BY XI- CAPTURE IN LIGHT-NUCLEI SO PHYSICAL REVIEW LETTERS LA English DT Article ID STRANGE MATTER AB We discuss the production of doubly strange LAMBDA-LAMBDA hypernuclei in XI- atomic capture. The two-body XI- + Li-6 --> LAMBDA-LAMBDA-He-6 + n reaction is a relatively favorable case, with a yield of order 3%. For heavier p-shell targets, such as N-14, the (1s-LAMBDA)2 ground-state yields in the XI- + (A)Z --> LAMBDA-LAMBDA-A(Z-1) + n reaction are suppressed, and states of (1s-LAMBDA-1p-LAMBDA) structure, coupled to an excited nuclear core, are preferentially populated. C1 BROOKHAVEN NATL LAB,DEPT PHYS,UPTON,NY 11973. HEBREW UNIV JERUSALEM,RACAH INST PHYS,IL-91904 JERUSALEM,ISRAEL. RP ZHU, D (reprint author), COLUMBIA UNIV,DEPT PHYS,NEW YORK,NY 10027, USA. NR 21 TC 34 Z9 34 U1 0 U2 0 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 0031-9007 J9 PHYS REV LETT JI Phys. Rev. Lett. PD OCT 21 PY 1991 VL 67 IS 17 BP 2268 EP 2271 DI 10.1103/PhysRevLett.67.2268 PG 4 WC Physics, Multidisciplinary SC Physics GA GK725 UT WOS:A1991GK72500008 ER PT J AU BEIERSDORFER, P OSTERHELD, AL SCOFIELD, J WARGELIN, B MARRS, RE AF BEIERSDORFER, P OSTERHELD, AL SCOFIELD, J WARGELIN, B MARRS, RE TI OBSERVATION OF MAGNETIC OCTUPOLE DECAY IN ATOMIC SPECTRA SO PHYSICAL REVIEW LETTERS LA English DT Article ID ELECTRIC QUADRUPOLE DECAYS; IONS; TOKAMAK; PLASMAS AB We report the first observation of magnetic octupole decay in the x-ray spectrum of a highly charged ion. Detailed analyses of the low-energy region of the n = 3 --> 4 spectra of nickel-like Th62+ and U64+ show an intense line at 2558.7 +/- 0.2 and 2689.3 +/- 0.2 eV, respectively, that is attributed to the transition (3d(9)4s)j = 3 --> (3d10)j = 0. Calculations indicate that the line is almost exclusively excited by indirect processes such as radiative cascades and electron capture. RP BEIERSDORFER, P (reprint author), UNIV CALIF LAWRENCE LIVERMORE NATL LAB,LIVERMORE,CA 94550, USA. NR 19 TC 49 Z9 49 U1 0 U2 3 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 0031-9007 J9 PHYS REV LETT JI Phys. Rev. Lett. PD OCT 21 PY 1991 VL 67 IS 17 BP 2272 EP 2275 DI 10.1103/PhysRevLett.67.2272 PG 4 WC Physics, Multidisciplinary SC Physics GA GK725 UT WOS:A1991GK72500009 ER PT J AU WARK, DL BARTLETT, R BOWLES, TJ ROBERTSON, RGH SIVIA, DS TRELA, W WILKERSON, JF BROWN, GS CRASEMANN, B SORENSEN, SL SCHAPHORST, SJ KNAPP, DA HENDERSON, J TULKKI, J ABERG, T AF WARK, DL BARTLETT, R BOWLES, TJ ROBERTSON, RGH SIVIA, DS TRELA, W WILKERSON, JF BROWN, GS CRASEMANN, B SORENSEN, SL SCHAPHORST, SJ KNAPP, DA HENDERSON, J TULKKI, J ABERG, T TI CORRESPONDENCE OF ELECTRON-SPECTRA FROM PHOTOIONIZATION AND NUCLEAR INTERNAL-CONVERSION SO PHYSICAL REVIEW LETTERS LA English DT Article ID ARGON AB Electron energy spectra have been measured that result from K-shell ionization of Kr by two different mechanisms: (1) photoionization and (2) internal conversion in the decay of the isomeric state of Kr-83. it is demonstrated experimentally that these spectra, including satellites on the low-energy side of the primary 1s-electron peak, are identical. A theoretical interpretation of the identity of the spectra is given. The spectra agree well with a relativistic many-electron calculation in which the satellites are attributed to excitation and ionization of M and N electrons during the K-ionization process. C1 UNIV CALIF LOS ALAMOS SCI LAB,LOS ALAMOS,NM 87545. STANFORD SYNCHROTRON RADIAT LAB,STANFORD,CA 94305. UNIV OREGON,DEPT PHYS,EUGENE,OR 97403. UNIV CALIF LAWRENCE LIVERMORE NATL LAB,LIVERMORE,CA 94550. HELSINKI UNIV TECHNOL,PHYS LAB,SF-02150 ESPOO,FINLAND. OI Wilkerson, John/0000-0002-0342-0217; Sorensen, Stacey/0000-0002-1706-0232 NR 14 TC 28 Z9 28 U1 0 U2 2 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 0031-9007 J9 PHYS REV LETT JI Phys. Rev. Lett. PD OCT 21 PY 1991 VL 67 IS 17 BP 2291 EP 2294 DI 10.1103/PhysRevLett.67.2291 PG 4 WC Physics, Multidisciplinary SC Physics GA GK725 UT WOS:A1991GK72500014 ER PT J AU KRAUTH, W TRIVEDI, N CEPERLEY, D AF KRAUTH, W TRIVEDI, N CEPERLEY, D TI SUPERFLUID-INSULATOR TRANSITION IN DISORDERED BOSON SYSTEMS SO PHYSICAL REVIEW LETTERS LA English DT Article ID FUNCTION MONTE-CARLO; QUANTUM ANTIFERROMAGNETS; 2 DIMENSIONS; LOCALIZATION; SUPERCONDUCTIVITY; CONDENSATION; METALS; ONSET AB We present results of path-integral Monte Carlo simulations of bosons on a two-dimensional square lattice in a random potential of average strength V and with on-site repulsion U. We find that the superfluid density rho-s is enhanced by increasing V and U in certain regions of parameter space. By combining the results of rho-s with the behavior of the density-density correlation function on lattices of size up to 10 x 10, we study the superfluid-to-Mott-insulator transition and the transition from a superfluid to a disorder-localized ("Bose-glass") phase. C1 SUNY STONY BROOK,DEPT PHYS,STONY BROOK,NY 11794. ARGONNE NATL LAB,DIV MAT SCI,ARGONNE,IL 60439. RP KRAUTH, W (reprint author), UNIV ILLINOIS,NATL CTR SUPERCOMP APPLICAT,URBANA,IL 61801, USA. RI Ceperley, David/A-6858-2008; Krauth, Werner/L-5623-2016 OI Krauth, Werner/0000-0003-0183-6726 NR 24 TC 235 Z9 235 U1 0 U2 9 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 0031-9007 J9 PHYS REV LETT JI Phys. Rev. Lett. PD OCT 21 PY 1991 VL 67 IS 17 BP 2307 EP 2310 DI 10.1103/PhysRevLett.67.2307 PG 4 WC Physics, Multidisciplinary SC Physics GA GK725 UT WOS:A1991GK72500018 ER PT J AU HAO, ZD CLEM, JR AF HAO, ZD CLEM, JR TI LIMITATIONS OF THE LONDON MODEL FOR THE REVERSIBLE MAGNETIZATION OF TYPE-II SUPERCONDUCTORS SO PHYSICAL REVIEW LETTERS LA English DT Article ID PENETRATION DEPTH; ANISOTROPY AB We point out that the London model for the reversible magnetization M of high-kappa type-II superconductors in the intermediate-field region is quantitatively incorrect, and we discuss the implications on our understanding of the mixed state of type-II superconductors. We also show that the apparently linear dependence of M vs lnH in the intermediate-field region, a behavior that has been observed experimentally, can be obtained from a previously proposed variational model. C1 IOWA STATE UNIV SCI & TECHNOL, DEPT PHYS, AMES, IA 50011 USA. RP HAO, ZD (reprint author), US DOE, AMES LAB, AMES, IA 50011 USA. NR 20 TC 173 Z9 174 U1 1 U2 3 PU AMER PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 0031-9007 EI 1079-7114 J9 PHYS REV LETT JI Phys. Rev. Lett. PD OCT 21 PY 1991 VL 67 IS 17 BP 2371 EP 2374 DI 10.1103/PhysRevLett.67.2371 PG 4 WC Physics, Multidisciplinary SC Physics GA GK725 UT WOS:A1991GK72500034 ER PT J AU AKERA, H MACDONALD, AH GIRVIN, SM NORMAN, MR AF AKERA, H MACDONALD, AH GIRVIN, SM NORMAN, MR TI VORTEX-LATTICE STATES AT STRONG MAGNETIC-FIELDS SO PHYSICAL REVIEW LETTERS LA English DT Article ID DENSITY-WAVE STATE; SCANNING-TUNNELING-MICROSCOPE; II SUPERCONDUCTOR; FLUX LATTICE; QUANTIZATION; CORE AB At strong magnetic fields, Landau quantization invalidates the semiclassical approximations which underly the Ginzburg-Landau (GL) theory of the mixed states of type-II superconductors. We have solved the microscopic mean-field equations for the case of a two-dimensional electron system in the strong magnetic-field limit. For delta-function attractive interactions there exist n + 1 pairing channels in the nth Landau level. For n > 0, two channels share the maximum T(c) and the order parameter differs markedly from expectations based on GL theory. C1 ARGONNE NATL LAB,DIV MAT SCI,ARGONNE,IL 60439. RP AKERA, H (reprint author), INDIANA UNIV,DEPT PHYS,BLOOMINGTON,IN 47405, USA. RI Norman, Michael/C-3644-2013 NR 28 TC 49 Z9 49 U1 0 U2 4 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 0031-9007 J9 PHYS REV LETT JI Phys. Rev. Lett. PD OCT 21 PY 1991 VL 67 IS 17 BP 2375 EP 2378 DI 10.1103/PhysRevLett.67.2375 PG 4 WC Physics, Multidisciplinary SC Physics GA GK725 UT WOS:A1991GK72500035 ER PT J AU KES, PH VANDERBEEK, CJ MALEY, MP MCHENRY, ME HUSE, DA MENKEN, MJV MENOVSKY, AA AF KES, PH VANDERBEEK, CJ MALEY, MP MCHENRY, ME HUSE, DA MENKEN, MJV MENOVSKY, AA TI FIELD-INDUCED SUPPRESSION OF THE PHASE-TRANSITION IN BI2SR2CACU2O8 SO PHYSICAL REVIEW LETTERS LA English DT Article ID HIGH-TEMPERATURE SUPERCONDUCTORS; LAYERED SUPERCONDUCTORS; SINGLE-CRYSTALS; DIAMAGNETISM; ANISOTROPY; ORDER; CREEP AB Magnetization measurements in field on a Bi2Sr2CaCu2O8 single crystal do not reveal any sharp phase transition between the normal and superconducting states. The M(H) curves for temperatures about T(c) in fields up to 5 T all display diamagnetic behavior. Above the mean-field transition temperature T(c)MF, quasi-two-dimensional diamagnetic fluctuations are responsible. Below T(c)MF strong deviations from the conventional mean-field (Abrikosov) behavior lead to an apparent T(c)(B) which increases with field. This effect clearly demonstrates the inadequacy of the mean-field theory to describe the vortex state below the crossover line H(c2)(T). C1 AT&T BELL LABS,MURRAY HILL,NJ 07974. UNIV AMSTERDAM,NAT LAB,AMSTERDAM,NETHERLANDS. LEIDEN UNIV,KAMERLINGH ONNES LAB,2300 RA LEIDEN,NETHERLANDS. CARNEGIE MELLON UNIV,DEPT MET ENGN & MAT SCI,PITTSBURGH,PA 15213. RP KES, PH (reprint author), UNIV CALIF LOS ALAMOS SCI LAB,CTR EXPLORATORY RES & DEV,LOS ALAMOS,NM 87545, USA. RI McHenry, Michael/B-8936-2009 NR 25 TC 116 Z9 116 U1 0 U2 2 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 0031-9007 J9 PHYS REV LETT JI Phys. Rev. Lett. PD OCT 21 PY 1991 VL 67 IS 17 BP 2383 EP 2386 DI 10.1103/PhysRevLett.67.2383 PG 4 WC Physics, Multidisciplinary SC Physics GA GK725 UT WOS:A1991GK72500037 ER PT J AU GENG, GQ WANG, BQ HOU, PY LEVY, AV AF GENG, GQ WANG, BQ HOU, PY LEVY, AV TI THE EFFECT OF ADDITIONAL SILICON ON THE CORROSION AND EROSION CORROSION OF LOW CHROMIUM STEELS SO WEAR LA English DT Article ID ALLOYS; OXIDATION; CR AB The addition of 1wt.%Si to commercial steel containing 2.5wt.%Cr significantly lowered its erosion-corrosion metal wastage rate at 650-degrees-C. The improved erosion resistance was largely a result of a modified corrosion behavior. Static oxidation studies showed that the normal silicon content 2.5Cr steel developed a duplex, spalling prone, iron-rich scale at 650-degrees-C. However, with the addition of silicon, the scale was almost 50 times thinner, and was chromium-rich instead. Metal wastage was significantly reduced for static and dynamic corrosion as well as for erosion-corrosion. The thin scale that formed on the additional silicon steels cracked and chipped off at a low metal loss rate compared with the thick scale that formed on the normal silicon steels that spalled off at a higher metal loss rate. C1 UNIV CALIF BERKELEY,LAWRENCE BERKELEY LAB,BERKELEY,CA 94720. RP GENG, GQ (reprint author), XIAN INST HIGHWAYS,XIAN,PEOPLES R CHINA. NR 20 TC 8 Z9 9 U1 0 U2 0 PU ELSEVIER SCIENCE SA LAUSANNE PI LAUSANNE 1 PA PO BOX 564, 1001 LAUSANNE 1, SWITZERLAND SN 0043-1648 J9 WEAR JI Wear PD OCT 21 PY 1991 VL 150 IS 1-2 BP 89 EP 105 DI 10.1016/0043-1648(91)90308-H PG 17 WC Engineering, Mechanical; Materials Science, Multidisciplinary SC Engineering; Materials Science GA GN607 UT WOS:A1991GN60700008 ER PT J AU WANG, BQ GENG, GQ LEVY, AV AF WANG, BQ GENG, GQ LEVY, AV TI EROSIVITY OF PARTICLES FROM OPERATING FLUIDIZED-BED COMBUSTORS SO WEAR LA English DT Article AB The erosion-corrosion (E-C) metal wastage mechanisms and rates that occur in 1018 plain carbon steel used in tubular heat exchangers of fluid bed combustors (FBCs) are discussed. The characteristics of FBC bed material erodent particles such as composition, shape, size and strength were found to have a major effect on the surface degradation mechanisms and rates which occurred. A total of 16 different bed material particles from ten different FBCs were tested. It was determined that when the particles were strong enough not to shatter upon impact, their shape and composition were the most important factors in determining their erosivity. The basic E-C mechanism was the formation of an outer layer of bed material deposit or mixed bed material and iron oxide that was eroded away in a brittle manner by cracking and chipping of a segmented scale. Beneath the outer layer i mixture of varying amounts of iron oxide and bed material occurred, with the iron oxide content increasing as the base metal was approached. The morphology and behavior of the outer layer are closely related to the metal wastage of the tubing steel. C1 UNIV CALIF BERKELEY,LAWRENCE BERKELEY LAB,BERKELEY,CA 94720. RP WANG, BQ (reprint author), XIAN INST HIGHWAYS,XIAN,PEOPLES R CHINA. NR 7 TC 9 Z9 9 U1 0 U2 0 PU ELSEVIER SCIENCE SA LAUSANNE PI LAUSANNE 1 PA PO BOX 564, 1001 LAUSANNE 1, SWITZERLAND SN 0043-1648 J9 WEAR JI Wear PD OCT 21 PY 1991 VL 150 IS 1-2 BP 107 EP 124 PG 18 WC Engineering, Mechanical; Materials Science, Multidisciplinary SC Engineering; Materials Science GA GN607 UT WOS:A1991GN60700009 ER PT J AU GENG, GQ WANG, BQ LEVY, AV AF GENG, GQ WANG, BQ LEVY, AV TI THE EFFECT OF THE COMPOSITION OF FLUIDIZED-BED COMBUSTOR BED MATERIALS ON THE EROSION CORROSION OF CARBON-STEEL SO WEAR LA English DT Article AB The relative amounts of SiO2, CaO, CaCO3, CaSO4, and alkali compounds in the bed materials of circulating fluidized bed combustors determine the metal wastage of heat exchanger tubing alloys exposed to the particles. The weight ratio Of SiO2 to CaO and to CaCO3 is especially important in determining the erosivity of the bed materials. It was found that increasing this ratio increased the metal wastage. A sharp transition ratio occurred, on either side of which the metal wastages were linear. The slope of the linear curve was low for the lower sand content mixtures and higher for the higher sand content mixtures. The transition ratio required a higher CaO content for higher velocity particles. The transition ratio of SiO2 to CaCO3 is related to the formation or lack of formation of a protective layer on the metal surface. The transition ratio of SiO2 to CaO is related to the formation of a thick protective layer or a thin, less protective layer on the metal surface. In the thick layer, CaO mechanically mixed with iron oxide to form an intimate mixture whose CaO content decreased inward from the gas-scale layer surface. C1 UNIV CALIF BERKELEY,LAWRENCE BERKELEY LAB,BERKELEY,CA 94720. RP GENG, GQ (reprint author), XIAN INST HIGHWAYS,XIAN,PEOPLES R CHINA. NR 7 TC 3 Z9 4 U1 1 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 OCT 21 PY 1991 VL 150 IS 1-2 BP 125 EP 134 DI 10.1016/0043-1648(91)90310-Q PG 10 WC Engineering, Mechanical; Materials Science, Multidisciplinary SC Engineering; Materials Science GA GN607 UT WOS:A1991GN60700010 ER PT J AU RAO, MK KEISER, J LEVY, AV WANG, BQ AF RAO, MK KEISER, J LEVY, AV WANG, BQ TI MECHANICAL-BEHAVIOR OF EROSION CORROSION SCALES ON STEELS AS CHARACTERIZED BY SINGLE-PARTICLE IMPACTS SO WEAR LA English DT Article ID 9CR-1MO STEEL; TEMPERATURE AB Samples of 2.25Cr-1Mo (less than 0.5 Si) and 2.5Cr-0.55Mo-1.4Si steels were eroded-corroded at 450 and 650-degrees-C using fluidized bed combustor bed particles at velocities of 10 and 20 m s-1. The steel with higher silicon content showed significantly lower metal loss rates under all conditions. The samples were subsequently subjected to single-particle impacts using spherical WC particles at velocities around 50 m s-1. The impact response of the scales could be explained in terms of a combination of substrate hardness and scale morphology effects but could not be consistently related to the superior erosion-corrosion resistance of the steel with higher silicon content. All scales were composed of oxidation product and deposited bed material erodent. Samples eroded-corroded at 450-degrees-C had denser, more mechanically stable scales which could be associated with the generally lower erosion-corrosion rates at this temperature. At 650-degrees-C the scales were more loosely packed, especially at the lower erosion-corrosion velocity, which resulted in apparent ductility by permitting them to densify under impact. Scales were either segmented or continuous in appearance. Thick continuous scales maintained their integrity under the lower velocity conditions of the erosion-corrosion tests, thus leading to low metal losses, but spalled catastrophically under the single impacts. Segmented scales spalled in smaller pieces under single impacts. It is proposed that the segmented scales would exhibit significant failure under low velocity conditions, thus providing less protection to the steels than continuous scales under similar conditions. C1 UNIV CALIF BERKELEY,LAWRENCE BERKELEY LAB,BERKELEY,CA 94720. RP RAO, MK (reprint author), OAK RIDGE NATL LAB,DIV MET & CERAM,OAK RIDGE,TN 37831, USA. NR 16 TC 3 Z9 3 U1 0 U2 0 PU ELSEVIER SCIENCE SA LAUSANNE PI LAUSANNE 1 PA PO BOX 564, 1001 LAUSANNE 1, SWITZERLAND SN 0043-1648 J9 WEAR JI Wear PD OCT 21 PY 1991 VL 150 IS 1-2 BP 135 EP 152 DI 10.1016/0043-1648(91)90311-H PG 18 WC Engineering, Mechanical; Materials Science, Multidisciplinary SC Engineering; Materials Science GA GN607 UT WOS:A1991GN60700011 ER PT J AU JERVIS, TR HIRVONEN, JP AF JERVIS, TR HIRVONEN, JP TI TRIBOLOGY AND SURFACE MECHANICAL-PROPERTIES OF THE OXIDE FILM FORMED BY EXCIMER LASER SURFACE-TREATMENT OF AISI-304 STAINLESS-STEEL SO WEAR LA English DT Article ID NITROGEN; FRICTION; WEAR AB The surface hardness and tribological properties of the surface oxide formed by excimer laser surface processing of AISI 304 stainless steel have been examined. It is found that laser processing initially anneals the stress-induced martensite on the surface of the stainless steel, resulting in a softening of the surface. After more than 100 cycles of melting and resolidification, a surface oxide film develops which is harder than the austenite of the annealed substrate and comparable in hardness to the stress-induced martensite. The thickness of the oxide film is dependent on the number of laser pulses, so that arbitrarily thick films can be produced. The dry-sliding friction of the oxide film against a steel pin is substantially lower than that of the untreated polished surface with only the native oxide film and there is substantially less damage in both the wear track and the pin. The hard surface oxide is underlain by relatively soft austenite. The tribological behavior is thus not obviously the result of the surface mechanical properties of the film-substrate combination but is ascribed to changes in the chemical interaction between the pin and the disk. RP JERVIS, TR (reprint author), UNIV CALIF LOS ALAMOS SCI LAB,CTR MAT SCI,LOS ALAMOS,NM 87545, USA. NR 10 TC 5 Z9 5 U1 1 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 OCT 21 PY 1991 VL 150 IS 1-2 BP 259 EP 265 DI 10.1016/0043-1648(91)90321-K PG 7 WC Engineering, Mechanical; Materials Science, Multidisciplinary SC Engineering; Materials Science GA GN607 UT WOS:A1991GN60700021 ER PT J AU CHENG, J OLBRIGHT, GR BRYAN, RP AF CHENG, J OLBRIGHT, GR BRYAN, RP TI BINARY ARITHMETIC USING OPTICAL SYMBOLIC SUBSTITUTION AND INTEGRATED PHOTOTRANSISTOR SURFACE-EMITTING LASER LOGIC SO APPLIED OPTICS LA English DT Note ID TRANSMISSION ELECTROPHOTONIC DEVICE; OUTPUT AB We outline an architecture for performing binary addition by using optical symbolic substitution and optical logic gates based on heterojunction phototransistors and vertical-cavity surface-emitting lasers. C1 SANDIA NATL LABS,ALBUQUERQUE,NM 87185. RP CHENG, J (reprint author), UNIV NEW MEXICO,CTR HIGH TECHNOL,ALBUQUERQUE,NM 87131, USA. NR 8 TC 4 Z9 4 U1 0 U2 2 PU OPTICAL SOC AMER PI WASHINGTON PA 2010 MASSACHUSETTS AVE NW, WASHINGTON, DC 20036 SN 0003-6935 J9 APPL OPTICS JI Appl. Optics PD OCT 20 PY 1991 VL 30 IS 30 BP 4284 EP 4287 PG 4 WC Optics SC Optics GA GQ421 UT WOS:A1991GQ42100003 PM 20717196 ER PT J AU CRANE, JK PRESTA, RW CHRISTENSEN, JJ COOKE, JD SHAW, MJ JOHNSON, MA PAISNER, JA AF CRANE, JK PRESTA, RW CHRISTENSEN, JJ COOKE, JD SHAW, MJ JOHNSON, MA PAISNER, JA TI GROUP-DELAY DIAGNOSTIC FOR MEASURING VAPOR COLUMN DENSITY SO APPLIED OPTICS LA English DT Article ID NUMBER DENSITY; METAL VAPOR AB We describe a technique for determining Nfl by measuring the group-velocity delay of a probe laser beam propagating through a vapor. This diagnostic has wide dynamic range, is simple to implement, and can be used as a high-bandwidth vapor rate monitor. In addition, it can be used to measure column density, Nl, number density, N, oscillator strengths, f, or absorption cross sections, collisional line broadening, and vapor group-velocity delay. RP CRANE, JK (reprint author), UNIV CALIF LAWRENCE LIVERMORE NATL LAB,POB 808,L-490,LIVERMORE,CA 94509, USA. NR 19 TC 9 Z9 9 U1 0 U2 2 PU OPTICAL SOC AMER PI WASHINGTON PA 2010 MASSACHUSETTS AVE NW, WASHINGTON, DC 20036 SN 0003-6935 J9 APPL OPTICS JI Appl. Optics PD OCT 20 PY 1991 VL 30 IS 30 BP 4289 EP 4296 PG 8 WC Optics SC Optics GA GQ421 UT WOS:A1991GQ42100005 PM 20717198 ER PT J AU MOLLER, KD SIDDONS, DP HIRSCHMUGL, CJ SCARDINO, D PETRONE, P CARLSON, D WILLIAMS, GP AF MOLLER, KD SIDDONS, DP HIRSCHMUGL, CJ SCARDINO, D PETRONE, P CARLSON, D WILLIAMS, GP TI 2-MIRROR WAVE-FRONT-DIVIDING INTERFEROMETER FOR INFRARED SYNCHROTRON RADIATION SO APPLIED OPTICS LA English DT Article AB We describe what is to our knowledge the first instrument specifically designed for use with infrared synchrotron radiation that takes advantage of the spatial coherence of this radiation. Beam splitting is achieved by wave-front division. We show data taken with the instrument over the wavelength region from 10 to 1000-mu-m (1-mm wavelengths) and discuss the advantages of this instrument over a conventional one. C1 BROOKHAVEN NATL LAB,NATL SYNCHROTRON LIGHT SOURCE,UPTON,NY 11973. RP MOLLER, KD (reprint author), FAIRLEIGH DICKINSON UNIV,DEPT PHYS,TEANECK,NJ 07666, USA. NR 10 TC 4 Z9 5 U1 0 U2 2 PU OPTICAL SOC AMER PI WASHINGTON PA 2010 MASSACHUSETTS AVE NW, WASHINGTON, DC 20036 SN 0003-6935 J9 APPL OPTICS JI Appl. Optics PD OCT 20 PY 1991 VL 30 IS 30 BP 4297 EP 4301 PG 5 WC Optics SC Optics GA GQ421 UT WOS:A1991GQ42100006 PM 20717199 ER PT J AU JELLISON, GE SALES, BC AF JELLISON, GE SALES, BC TI DETERMINATION OF THE OPTICAL FUNCTIONS OF TRANSPARENT GLASSES BY USING SPECTROSCOPIC ELLIPSOMETRY SO APPLIED OPTICS LA English DT Article ID ELEVATED-TEMPERATURES; REFRACTIVE-INDEX; DEPTH-PROFILE; THIN-FILMS; DISPERSION; SILICON; CARBIDE; SI; GE AB Two-channel spectroscopic polarization-modulation ellipsometry measurements have been made on four different glasses (fused SiO2, finely annealed BK-7, a lead-indium-phosphate glass, and a germanium-arsenic-selenium glass). We show that this technique is sensitive to thin surface layers and that these surface layers can be modeled by using the Bruggeman effective-medium theory with 50% glass and 50% voids. By correcting the experimental spectra for this surface layer, we determined the refractive index of the sample within an error of +/- 0.002 in the transparent region. For wavelength regions where the material is normally opaque, the ellipsometric data can be corrected for this overlayer, thereby increasing the accuracy of the determination of both the refractive index and the extinction coefficient. RP JELLISON, GE (reprint author), OAK RIDGE NATL LAB, DIV SOLID STATE, OAK RIDGE, TN 37831 USA. NR 24 TC 30 Z9 31 U1 0 U2 7 PU OPTICAL SOC AMER PI WASHINGTON PA 2010 MASSACHUSETTS AVE NW, WASHINGTON, DC 20036 SN 0003-6935 J9 APPL OPTICS JI Appl. Optics PD OCT 20 PY 1991 VL 30 IS 30 BP 4310 EP 4315 PG 6 WC Optics SC Optics GA GQ421 UT WOS:A1991GQ42100008 PM 20717201 ER PT J AU PETERSEN, JN DAVISON, BH SCOTT, CD BLANKINSHIP, SL AF PETERSEN, JN DAVISON, BH SCOTT, CD BLANKINSHIP, SL TI SIZE CHANGES ASSOCIATED WITH METAL ADSORPTION ONTO MODIFIED BONE GELATIN BEADS SO BIOTECHNOLOGY AND BIOENGINEERING LA English DT Article ID COUNTERION CONDENSATION; ELECTROLYTE-SOLUTIONS; GELS AB Significant quantities of heavy metals will adsorb onto modified bone gelatin beads. As this adsorption occurs, the bead can undergo a substantial volume change. Research has shown that the equilibrium bead diameter was a function of the solution pH and the ion concentration in the solution. Here, we demonstrate that under certain conditions, the volume of the beads that adsorbed the metal was only 35% of the bead volume when no metal was adsorbed. By taking advantage of these size changes, a fluidized-bed separator can be operated such that natural segregation of loaded beads occurs. This phenomenon may facilitate the design of continuous separators for the recovery and concentration of heavy-metal-contaminated waters. These concepts are demonstrated using Cu2+ adsorption onto such beads. C1 OAK RIDGE NATL LAB,DIV CHEM TECHNOL,OAK RIDGE,TN 37831. RP PETERSEN, JN (reprint author), WASHINGTON STATE UNIV,DEPT CHEM ENGN,PULLMAN,WA 99164, USA. RI Petersen, James/B-8924-2008; Davison, Brian/D-7617-2013 OI Davison, Brian/0000-0002-7408-3609 NR 13 TC 4 Z9 4 U1 0 U2 3 PU JOHN WILEY & SONS INC PI NEW YORK PA 605 THIRD AVE, NEW YORK, NY 10158-0012 SN 0006-3592 J9 BIOTECHNOL BIOENG JI Biotechnol. Bioeng. PD OCT 20 PY 1991 VL 38 IS 8 BP 923 EP 928 DI 10.1002/bit.260380813 PG 6 WC Biotechnology & Applied Microbiology SC Biotechnology & Applied Microbiology GA GJ270 UT WOS:A1991GJ27000012 PM 18600848 ER EF