FN Thomson Reuters Web of Science™ VR 1.0 PT J AU STEPHENS, GL SLINGO, A WEBB, MJ MINNETT, PJ DAUM, PH KLEINMAN, L WITTMEYER, I RANDALL, DA AF STEPHENS, GL SLINGO, A WEBB, MJ MINNETT, PJ DAUM, PH KLEINMAN, L WITTMEYER, I RANDALL, DA TI OBSERVATIONS OF THE EARTHS RADIATION BUDGET IN RELATION TO ATMOSPHERIC HYDROLOGY .4. ATMOSPHERIC COLUMN RADIATIVE COOLING OVER THE WORLDS OCEANS SO JOURNAL OF GEOPHYSICAL RESEARCH-ATMOSPHERES LA English DT Article ID SENSOR MICROWAVE IMAGER; LONGWAVE RADIATION; GLOBAL OCEANS; WATER-VAPOR; SURFACE; CLIMATE AB This paper introduces a simple method for deriving climatological values of the longwave flux emitted from the clear sky atmosphere to the ice-free ocean surface. Simulations of the clear sky longwave fluxes to space and to the surface are employed in this study to assist in the development of this flux retrieval which requires monthly averaged column-integrated water vapor w and the clear sky top-of-atmosphere (TOA) outgoing longwave flux (both available from satellite measurements). It is shown using both theory and data. from simulations how the ratio of the surface to TOA flux is a simple function of w, and a validation of the simple relationship is presented based on a limited set of surface flux measurements. The rms difference between the retrieved surface fluxes and the simulated surface fluxes is approximately 6 W m(-2). The clear sky column cooling rate of the atmosphere is derived from the Earth Radiation Budget Experiment (ERBE) values of the clear sky TOA flux and the surface flux retrieved using Special Scanning Microwave Imager (SSM/I) measurements of w together with ERBE clear sky fluxes. The relationship between this column cooling rate, w and the sea surface temperature (SST) is explored and it is shown how the cooling rate systematically increases as both w and SST increase. The uncertainty implied in these estimates of cooling are approximately +/-0.2 K d(-1). The effects of clouds on this longwave cooling are also explored in a limited way by placing bounds on the possible impact of clouds on the column cooling rate based on certain assumptions about the effect of clouds on the longwave flux to the surface. While a more global assessment of the cloud effect must await use of new satellite data that will allow us to estimate the contributions by clouds to these surface fluxes, it is shown in this paper how the longwave effects of clouds in a moist atmosphere where the column water vapor exceeds approximately 30 kg m(-2) may be estimated from presently available satellite data with an uncertainty estimated to be approximately 0.2 K d(-1) Based on an approach described in this paper, we show how clouds in these relatively moist regions decrease the column cooling by almost 50% of the clear sky values and the existence of significant longitudinal gradients in column radiative heating across the equatorial and subtropical. Pacific Ocean. C1 HADLEY CTR CLIMATE PREDICT & RES, METEOROL OFF, BRACKNELL, BERKS, ENGLAND. BROOKHAVEN NATL LAB, DIV ENVIRONM CHEM, UPTON, NY 11973 USA. BROOKHAVEN NATL LAB, DIV OCEANOG & ATMOSPHER SCI, UPTON, NY 11973 USA. RP STEPHENS, GL (reprint author), COLORADO STATE UNIV, DEPT ATMOSPHER SCI, FT COLLINS, CO 80523 USA. RI Randall, David/E-6113-2011 OI Randall, David/0000-0001-6935-4112 NR 34 TC 43 Z9 43 U1 0 U2 7 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 2169-897X J9 J GEOPHYS RES-ATMOS JI J. Geophys. Res.-Atmos. PD SEP 20 PY 1994 VL 99 IS D9 BP 18585 EP 18604 DI 10.1029/94JD01151 PG 20 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA PH357 UT WOS:A1994PH35700007 ER PT J AU TANG, IN MUNKELWITZ, HR AF TANG, IN MUNKELWITZ, HR TI WATER ACTIVITIES, DENSITIES, AND REFRACTIVE-INDEXES OF AQUEOUS SULFATES AND SODIUM-NITRATE DROPLETS OF ATMOSPHERIC IMPORTANCE SO JOURNAL OF GEOPHYSICAL RESEARCH-ATMOSPHERES LA English DT Article ID AEROSOLS; VISIBILITY; PARTICLES; CYCLE; INDEX AB Water activities, densities, and refractive indices over extended concentration ranges at 25 degrees C are reported for solution droplets containing a single salt of either (NH4)(2)SO4, NH4HSO4, (NH4)(3)H(SO4)(2), Na2SO4, NaHSO4, or NaNO3, which are common constituents of atmospheric aerosols. The extensive data reported here are obtained from experiments using the single-particle levitation technique recently developed for measuring the thermodynamic and optical properties of microdroplets. These data should find application in mathematical models predicting the dynamic behavior, visibility reduction, and radiative effects of atmospheric sulfate and nitrate aerosols. C1 BROOKHAVEN NATL LAB, DIV ENVIRONM CHEM, UPTON, NY 11973 USA. NR 32 TC 561 Z9 580 U1 12 U2 112 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 2169-897X EI 2169-8996 J9 J GEOPHYS RES-ATMOS JI J. Geophys. Res.-Atmos. PD SEP 20 PY 1994 VL 99 IS D9 BP 18801 EP 18808 DI 10.1029/94JD01345 PG 8 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA PH357 UT WOS:A1994PH35700023 ER PT J AU LINDEMER, TB CHAKOUMAKOS, BC SPECHT, ED WILLIAMS, RK CHEN, YJ AF LINDEMER, TB CHAKOUMAKOS, BC SPECHT, ED WILLIAMS, RK CHEN, YJ TI EFFECTS OF COMPOSITION AND PROCESSING ON THE SUPERCONDUCTIVITY OF LA1+ZBA2-ZCU3OY SO PHYSICA C LA English DT Article ID AEROSOL DECOMPOSITION; OXYGEN-PRESSURE; PHASE; YBA2CU3O7-X; LABA2CU3OY; SYSTEM; 90-K; TC; NONSTOICHIOMETRY; PEROVSKITES AB The effects of composition, processing time (t), temperature (T) and O-2 partial pressure (p(O2)) on the superconducting transition temperature, T-c, were investigated for La1+zBa2-zCu3Oy. Tallon and Flower's prediction of T-c approximate to 100 K [Physica C 204 (1993) 237] at z = 0 could not be attained. Instead, the T-c maximum of 93-94 K is similar to that of the yttria analog. As z was increased, the T-c values increased gradually by a few kelvin until z = 0.2, which is at the orthorhombic to tetragonal transition, and then decreased more abruptly, with no superconductivity for z greater than or equal to 0.5. Crucial steps in the process at all z values include the highest temperature anneal ( 1065 degrees C) in 0.1 MPa O-2, reduction of the oxygen content at 950 degrees C and cooling to 300-400 degrees C, both at 100-1000 Pa O-2, and reoxygenation at 0.1 MPa O-2 during slow cooling (5-20 degrees C/min) to < 150 degrees C. Additional experiments demonstrated that the intragranular critical current was less than that for the yttria analog. Values of T-c decreased fairly monotonically with decreasing y at z = 0.08, and a La excess of 0.2 and Cu nonstoichiometry on both sides of Cu/(La + Ba) = 1 generally depressed T-c. C1 OAK RIDGE NATL LAB,DIV SOLID STATE,OAK RIDGE,TN 37831. OAK RIDGE NATL LAB,DIV MET & CERAM,OAK RIDGE,TN 37831. UNIV TENNESSEE,DEPT PHYS,KNOXVILLE,TN 37996. RP LINDEMER, TB (reprint author), OAK RIDGE NATL LAB,DIV CHEM TECHNOL,POB 2008,OAK RIDGE,TN 37831, USA. RI Specht, Eliot/A-5654-2009; Chakoumakos, Bryan/A-5601-2016 OI Specht, Eliot/0000-0002-3191-2163; Chakoumakos, Bryan/0000-0002-7870-6543 NR 47 TC 42 Z9 42 U1 0 U2 1 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0921-4534 J9 PHYSICA C JI Physica C PD SEP 20 PY 1994 VL 231 IS 1-2 BP 80 EP 90 DI 10.1016/0921-4534(94)90144-9 PG 11 WC Physics, Applied SC Physics GA PJ982 UT WOS:A1994PJ98200010 ER PT J AU PARRELL, JA DORRIS, SE LARBALESTIER, DC AF PARRELL, JA DORRIS, SE LARBALESTIER, DC TI ON THE ROLE OF VICKERS AND KNOOP MICROHARDNESS AS A GUIDE TO DEVELOPING HIGH CRITICAL-CURRENT DENSITY AG-CLAD BSCCO-2223 TAPES SO PHYSICA C LA English DT Article ID SUPERCONDUCTING TAPES; PHASE FORMATION; SHEATHED TAPES; TC PHASE; SYSTEM AB Because there are many parameters influencing the critical current density (J(c)) of Ag sheathed (Bi, Pb)(2)Sr2Ca2Cu3Ox tapes, good and easily measured correlation variables to J(c) are highly desirable. Yamada et al. have recently shown that very high J(c) values can be obtained when the BSCCO core is rolled to a high Vickers microhardness (H-V) prior to heat treatment. The present experiment extends the correlation by showing that there is a linear relation between the H-V of reacted tapes and J(c). Measurement of the Knoop microhardness (H-K) shows that the hardness is highly anisotropic. H-K measured with the long indentor axis parallel to the a-b planes shows no dependence on reaction time or J(c), while H-K measured parallel to the c-axis is strongly correlated. A high microhardness appears to be directly correlated to a high-density BSCCO core with a small crack density. Such a core has good connectivity which directly translates to a high J(c) value. C1 UNIV WISCONSIN,CTR APPL SUPERCONDUCT,MADISON,WI 53706. UNIV WISCONSIN,MAT SCI PROGRAM,MADISON,WI 53706. ARGONNE NATL LAB,DIV ENERGY TECHNOL,ARGONNE,IL 60439. RI Larbalestier, David/B-2277-2008 OI Larbalestier, David/0000-0001-7098-7208 NR 26 TC 56 Z9 56 U1 2 U2 11 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0921-4534 J9 PHYSICA C JI Physica C PD SEP 20 PY 1994 VL 231 IS 1-2 BP 137 EP 146 DI 10.1016/0921-4534(94)90153-8 PG 10 WC Physics, Applied SC Physics GA PJ982 UT WOS:A1994PJ98200019 ER PT J AU GILCHRIST, J VANDERBEEK, CJ AF GILCHRIST, J VANDERBEEK, CJ TI NONLINEAR DIFFUSION IN HARD AND SOFT SUPERCONDUCTORS SO PHYSICA C-SUPERCONDUCTIVITY AND ITS APPLICATIONS LA English DT Article ID HIGH-TC SUPERCONDUCTORS; LOGARITHMIC U(J) DEPENDENCE; ORGANIZED CRITICAL STATE; FLUX CREEP; II SUPERCONDUCTORS; DENSITY AB We discuss the diffusion of magnetic flux in a field-cooled (''hard'') superconducting slab in a creep regime in which E proportional to \J\(sigma)J. Bryksin and Dorogovtsev recently discussed flux diffusion in a pinningless (''soft'') superconductor in which E proportional to \B\J. This problem is closely related to the flux-creep one with sigma=1, and provides additional insight into the possible types of behaviour. We list a series of possible long-term asymptotic solutions of a scaling form, which are either analytically exact or accurately calculated. We check numerically that the relevant long-term solution is approached after various initial conditions. Amongst other conclusions we find S=d(1n\M\)/d(1n t)-->-1/sigma or -1/2 sigma, after application and removal of an additional field, according to whether the disturbance has reached the sample centre or not. A relaxing sandpile model appears to have wide validity when creep is only a small correction to the critical state, as when sigma-->infinity. C1 ARGONNE NATL LAB, DIV MAT SCI, ARGONNE, IL 60439 USA. RP UNIV GRENOBLE 1, CNRS, CTR RECH TRES BASSES TEMP, BP 166X, F-38042 GRENOBLE 09, FRANCE. NR 27 TC 37 Z9 37 U1 0 U2 0 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0921-4534 EI 1873-2143 J9 PHYSICA C JI Physica C PD SEP 20 PY 1994 VL 231 IS 1-2 BP 147 EP 156 DI 10.1016/0921-4534(94)90154-6 PG 10 WC Physics, Applied SC Physics GA PJ982 UT WOS:A1994PJ98200020 ER PT J AU TIDSWELL, IM MARKOVIC, NM ROSS, PN AF TIDSWELL, IM MARKOVIC, NM ROSS, PN TI POTENTIAL-DEPENDENT STRUCTURE OF SINGLE-CRYSTAL GOLD INTERFACES IN ALKALINE ELECTROLYTE - AN IN-SITU X-RAY-SCATTERING STUDY SO SURFACE SCIENCE LA English DT Article ID SCANNING-TUNNELING-MICROSCOPY; INDUCED 1X3 RECONSTRUCTION; SURFACE RECONSTRUCTIONS; AU(111) SURFACE; AU(001) RECONSTRUCTION; ACIDIC ELECTROLYTES; AU(100); DIFFRACTION; REFLECTIVITY; DISLOCATIONS AB An X-ray scattering study of the structure of gold (001), (111), and (011) single crystals in 0.1M KOH electrolyte found that all three faces were reconstructed in the potential region where hydroxyl coverage was low. For the (001) and (111) surfaces, the reconstruction had a structure generally similar to the vacuum reconstruction (i.e. discommensurate distorted hexagonal and uniaxial compression, respectively). The (011) surface had a (1 x 3) ''missing row'' reconstruction, the same as found in neutral salt electrolytes, but different from the vacuum (1 x 2) reconstruction. The potentials at which the reconstruction formation and removal began were similar for all three faces. The kinetics of the reconstruction formation and removal were generally faster than in acidic electrolytes with non-adsorbing anions. The significant differences in the kinetics of transformation between the three faces were attributed to the markedly different density changes between the (1 x 1) and reconstructed structures and the consequent surface diffusion requirements. C1 LAWRENCE BERKELEY LAB,DIV MAT SCI,ONE CYCLOTRON RD,BERKELEY,CA 94720. NR 38 TC 13 Z9 13 U1 4 U2 10 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0039-6028 J9 SURF SCI JI Surf. Sci. PD SEP 20 PY 1994 VL 317 IS 1-2 BP 241 EP 252 DI 10.1016/0039-6028(94)90271-2 PG 12 WC Chemistry, Physical; Physics, Condensed Matter SC Chemistry; Physics GA PH032 UT WOS:A1994PH03200027 ER PT J AU SUCHA, G BOLTON, SR CHEMLA, DS SIVCO, DL CHO, AY AF SUCHA, G BOLTON, SR CHEMLA, DS SIVCO, DL CHO, AY TI CARRIER RELAXATION IN INGAAS HETEROSTRUCTURES SO APPLIED PHYSICS LETTERS LA English DT Article ID FEMTOSECOND GAIN DYNAMICS; WELL OPTICAL AMPLIFIERS; QUANTUM WELLS; SINGULARITIES; ABSORPTION; GENERATION; 1.5-MU-M; SYSTEMS; PULSES AB We present time-resolved measurements of carrier dynamics in bulk and quantum wells InGaAs, using differential absorption spectroscopy. We find that the carrier thermalization time is 200-300 fs regardless of layer width for sample thickness ranging from 100 to 6000 angstrom. The efficiency of screening relative to phase space filling is larger in the bulk than in the quantum wells. C1 LAWRENCE BERKELEY LAB,DIV MAT SCI,BERKELEY,CA 94720. AT&T BELL LABS,MURRAY HILL,NJ 07974. RP SUCHA, G (reprint author), UNIV CALIF BERKELEY,DEPT PHYS,BERKELEY,CA 94720, USA. NR 19 TC 9 Z9 9 U1 1 U2 2 PU AMER INST PHYSICS PI WOODBURY PA CIRCULATION FULFILLMENT DIV, 500 SUNNYSIDE BLVD, WOODBURY, NY 11797-2999 SN 0003-6951 J9 APPL PHYS LETT JI Appl. Phys. Lett. PD SEP 19 PY 1994 VL 65 IS 12 BP 1486 EP 1488 DI 10.1063/1.112020 PG 3 WC Physics, Applied SC Physics GA PG925 UT WOS:A1994PG92500004 ER PT J AU WALKER, FJ MCKEE, RA YEN, HW ZELMON, DE AF WALKER, FJ MCKEE, RA YEN, HW ZELMON, DE TI OPTICAL CLARITY AND WAVE-GUIDE PERFORMANCE OF THIN-FILM PEROVSKITES ON MGO SO APPLIED PHYSICS LETTERS LA English DT Article AB The optical clarity of a new class of thin film waveguides, epitaxial perovskites on MgO, has been characterized and found to have optical clarity comparable to in-diffused waveguide structures typically represented by Ti drifted LiNbO3. For the simplest member within this new class, SrTiO3, measurements of the wavelength dependence of optical loss show a monotonic decrease with increasing wavelength between 475 and 705 nm, reaching a value of 1 dB/cm at 705 nm. C1 HUGHES AIRCRAFT CO,OPT PHYS LAB,MALIBU,CA 90265. WRIGHT LAB,MAT DIRECTORATE,MLOP,WRIGHT PATTERSON AFB,OH 45433. UNIV TENNESSEE,KNOXVILLE,TN 37996. RP WALKER, FJ (reprint author), OAK RIDGE NATL LAB,OAK RIDGE,TN 37831, USA. OI Walker, Frederick/0000-0002-8094-249X NR 10 TC 46 Z9 46 U1 1 U2 2 PU AMER INST PHYSICS PI WOODBURY PA CIRCULATION FULFILLMENT DIV, 500 SUNNYSIDE BLVD, WOODBURY, NY 11797-2999 SN 0003-6951 J9 APPL PHYS LETT JI Appl. Phys. Lett. PD SEP 19 PY 1994 VL 65 IS 12 BP 1495 EP 1497 DI 10.1063/1.112023 PG 3 WC Physics, Applied SC Physics GA PG925 UT WOS:A1994PG92500007 ER PT J AU OSTAPENKO, SS JASTRZEBSKI, L LAGOWSKI, J SOPORI, B AF OSTAPENKO, SS JASTRZEBSKI, L LAGOWSKI, J SOPORI, B TI INCREASING SHORT MINORITY-CARRIER DIFFUSION LENGTHS IN SOLAR-GRADE POLYCRYSTALLINE SILICON BY ULTRASOUND TREATMENT SO APPLIED PHYSICS LETTERS LA English DT Article ID PHOTOELECTRIC PROPERTIES; SOLID-SOLUTIONS; LUMINESCENCE AB We have found that ultrasound treatment (UST) has a profound effect on the recombination rate in as-grown, B-doped cast polycrystalline silicon wafers for photovoltaic applications. As determined by surface photovoltage measurements of the minority carrier diffusion length L, the UST increases the corresponding lifetime by almost an order of magnitude. The maximum enhancement takes place in the wafer regions with the shortest L values. For L > 20 mum, both positive and negative changes of L after UST are revealed at different wafer regions. The UST effect is temperature dependent and exhibits maximum influence at about 60-degrees-C. Enhanced dissociation of Fe-B pairs by UST is identified as a mechanism which leads to a negative change of large L values, and a complex post-treatment relaxation. A positive change of L is attributed to the influence of ultrasound vibrations on crystallographic defects. C1 NATL RENEWABLE ENERGY LAB,GOLDEN,CO 80401. RP OSTAPENKO, SS (reprint author), UNIV S FLORIDA,CTR MICROELECTR RES,TAMPA,FL 33620, USA. NR 11 TC 17 Z9 17 U1 0 U2 3 PU AMER INST PHYSICS PI WOODBURY PA CIRCULATION FULFILLMENT DIV, 500 SUNNYSIDE BLVD, WOODBURY, NY 11797-2999 SN 0003-6951 J9 APPL PHYS LETT JI Appl. Phys. Lett. PD SEP 19 PY 1994 VL 65 IS 12 BP 1555 EP 1557 DI 10.1063/1.112942 PG 3 WC Physics, Applied SC Physics GA PG925 UT WOS:A1994PG92500027 ER PT J AU BRINKER, CJ SEHGAL, R HIETALA, SL DESHPANDE, R SMITH, DM LOY, D ASHLEY, CS AF BRINKER, CJ SEHGAL, R HIETALA, SL DESHPANDE, R SMITH, DM LOY, D ASHLEY, CS TI SOL-GEL STRATEGIES FOR CONTROLLED POROSITY INORGANIC MATERIALS SO JOURNAL OF MEMBRANE SCIENCE LA English DT Article; Proceedings Paper CT Alex Stern Honorary Symposium on Membrane-Based Gas Separations, at the AICHE Spring Meeting CY MAR 28-APR 01, 1993 CL HOUSTON, TX SP AMER INST CHEM ENGINEERS DE INORGANIC MEMBRANES; COMPOSITE MEMBRANES; GAS SEPARATIONS; GLASS MEMBRANES; MICROPOROUS AND POROUS MEMBRANES ID CHEMISTRY; NETWORKS AB The porosity (i.e., pore volume, pore size, and surface area) of ceramic materials prepared by sol-gel processing depends on the size and structure of primary particles or polymers formed by condensation reactions, the organization of these structures, often by aggregation, to form a gel, and the collapse of the gel by drying. This paper reviews these ideas in the context of the formation of thin films suitable for inorganic membranes and introduces a number of specific strategies designed to control pore sizes in the range appropriate for gas separation: (1) aggregation of fractals; (2) management of capillary pressure, (3) control of condensation rate, and (4) the use of organic or microporous templates in composite thin film structures. These strategies are contrasted with the more traditional particle packing approach to preparing controlled porosity materials. C1 UNIV NEW MEXICO,UNM NSF CTR MICROENGN CERAM,ALBUQUERQUE,NM 87131. SANDIA NATL LABS,ADV MAT LAB,ALBUQUERQUE,NM 87106. RI Loy, Douglas/D-4847-2009 OI Loy, Douglas/0000-0001-7635-9958 NR 40 TC 170 Z9 174 U1 2 U2 45 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0376-7388 J9 J MEMBRANE SCI JI J. Membr. Sci. PD SEP 19 PY 1994 VL 94 BP 85 EP 102 DI 10.1016/0376-7388(93)E0129-8 PG 18 WC Engineering, Chemical; Polymer Science SC Engineering; Polymer Science GA PK195 UT WOS:A1994PK19500004 ER PT J AU GILMAN, R BRASH, E EDWARDS, G GLASHAUSSER, C JONES, MK BAKER, FT BASTEA, S BEATTY, DP BIMBOT, L BRUSOE, J CHIBA, J COOPER, D KUMBARTZKI, G MAUGER, C NAGAE, T PARK, B PROUT, D RANSOME, RD RAWOOLSULLIVAN, M RUTT, P STORM, B SUGARBAKER, E TADDEUCCI, T ZUMBRO, J AF GILMAN, R BRASH, E EDWARDS, G GLASHAUSSER, C JONES, MK BAKER, FT BASTEA, S BEATTY, DP BIMBOT, L BRUSOE, J CHIBA, J COOPER, D KUMBARTZKI, G MAUGER, C NAGAE, T PARK, B PROUT, D RANSOME, RD RAWOOLSULLIVAN, M RUTT, P STORM, B SUGARBAKER, E TADDEUCCI, T ZUMBRO, J TI COHERENT PION-PRODUCTION IN C-12(P, N-PI) AT 800 MEV SO NUCLEAR PHYSICS A LA English DT Article; Proceedings Paper CT International Symposium on Spin-Isospin Responses and Weak Processes in Hadrons and Nuclei CY MAR 08-10, 1994 CL SENRI LIFE SCI CTR, OSAKA, JAPAN SP MINIST EDUC SCI & CULTURE JAPAN HO SENRI LIFE SCI CTR ID CHARGE-EXCHANGE REACTIONS; NUCLEI AB Studies of the production of the Delta resonance in hadronic charge exchange reactions show a shift in the Delta peak position. Measurements looking also at the Delta decay products give some evidence for coherent pion production. We have recently completed a new measurement of the C-12(p,n) reaction leading to the Delta resonance, including a higher resolution coincidence measurement of decay pi's in the forward direction. We describe the experiment and some aspects of the preliminary analysis. C1 COLL WILLIAM & MARY,WILLIAMSBURG,VA 23187. UNIV TOKYO,INST NUCL STUDY,TOKYO 188,JAPAN. INST PHYS NUCL LYON,F-91406 ORSAY,FRANCE. LOS ALAMOS NATL LAB,LOS ALAMOS,NM 87545. KEK,NATL LAB HIGH ENERGY PHYS,IBARAKI,OSAKA 305,JAPAN. OHIO STATE UNIV,COLUMBUS,OH 43212. UNIV GEORGIA,ATHENS,GA 30602. NEW MEXICO STATE UNIV,LAS CRUCES,NM 88003. RP GILMAN, R (reprint author), RUTGERS STATE UNIV,POB 849,PISCATAWAY,NJ 08854, USA. NR 9 TC 4 Z9 4 U1 0 U2 0 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0375-9474 J9 NUCL PHYS A JI Nucl. Phys. A PD SEP 19 PY 1994 VL 577 IS 1-2 BP C227 EP C232 PG 6 WC Physics, Nuclear SC Physics GA PH686 UT WOS:A1994PH68600039 ER PT J AU OTSUKA, T GINOCCHIO, JN AF OTSUKA, T GINOCCHIO, JN TI M1 EXCITATION OF DEFORMED-NUCLEI AND PROTON-NEUTRON CORRELATION SO NUCLEAR PHYSICS A LA English DT Article; Proceedings Paper CT International Symposium on Spin-Isospin Responses and Weak Processes in Hadrons and Nuclei CY MAR 08-10, 1994 CL SENRI LIFE SCI CTR, OSAKA, JAPAN SP MINIST EDUC SCI & CULTURE JAPAN HO SENRI LIFE SCI CTR AB The proton-neutron correlation in the axially-symmetric rotor is studied. It is shown that, in and near the ground state, the proton and neutron deformed ellipsoids are rotating in the opposite directions, whereas they rotate about almost the same axis in states of higher spins. This holds, quite similarly, for angular-momentum-projected Nilsson wave functions and for wave functions in the Interacting Boson Model. The M1 excitation from the ground state is shown to reflect this correlation between the proton and neutron ellipsoids. C1 LOS ALAMOS NATL LAB,DIV THEORET,LOS ALAMOS,NM 87545. RP OTSUKA, T (reprint author), UNIV TOKYO,DEPT PHYS,BUNKYO KU,TOKYO 113,JAPAN. RI OTSUKA, TAKAHARU/G-5072-2014 NR 10 TC 2 Z9 2 U1 0 U2 0 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0375-9474 J9 NUCL PHYS A JI Nucl. Phys. A PD SEP 19 PY 1994 VL 577 IS 1-2 BP C197 EP C202 PG 6 WC Physics, Nuclear SC Physics GA PH686 UT WOS:A1994PH68600034 ER PT J AU PROUT, D DELUCIA, S SUGARBAKER, E LUTHER, B COOPER, D TADDEUCCI, T RYBARCYK, L MCCLELLAND, J GOODMAN, C PARK, B RAPAPORT, J SAMS, T EDWARDS, G GLASSHAUSER, C AF PROUT, D DELUCIA, S SUGARBAKER, E LUTHER, B COOPER, D TADDEUCCI, T RYBARCYK, L MCCLELLAND, J GOODMAN, C PARK, B RAPAPORT, J SAMS, T EDWARDS, G GLASSHAUSER, C TI SPIN-LONGITUDINAL AND SPIN-TRANSVERSE CROSS-SECTIONS FOR DELTA-PRODUCTION IN THE C-12((P)OVER-RIGHT-ARROW,(N)OVER-RIGHT-ARROW) REACTION SO NUCLEAR PHYSICS A LA English DT Article; Proceedings Paper CT International Symposium on Spin-Isospin Responses and Weak Processes in Hadrons and Nuclei CY MAR 08-10, 1994 CL SENRI LIFE SCI CTR, OSAKA, JAPAN SP MINIST EDUC SCI & CULTURE JAPAN HO SENRI LIFE SCI CTR AB We present (($) over right arrow p, ($) over right arrow n) spin observable measurements in the delta region of excitation taken on the targets H-2 and C-12 at 0 degrees and 795 MeV proton energy. These observables have been used to form the spin-longitudinal and spin-transverse cross sections. Good agreement is found between experiment and theory in the spin-longitudinal channel. C1 LOS ALAMOS NATL LAB,LOS ALAMOS,NM 87545. INDIANA UNIV,CYCLOTRON FACIL,BLOOMINGTON,IN 47405. NEW MEXICO STATE UNIV,LAS CRUCES,NM 88003. OHIO UNIV,ATHENS,OH 45701. NIELS BOHR INST,DK-2100 COPENHAGEN,DENMARK. RUTGERS STATE UNIV,PISCATAWAY,NJ 08855. RP PROUT, D (reprint author), OHIO STATE UNIV,COLUMBUS,OH 43212, USA. RI Sams, Thomas/A-9781-2014 OI Sams, Thomas/0000-0002-6316-2539 NR 7 TC 12 Z9 12 U1 0 U2 0 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0375-9474 J9 NUCL PHYS A JI Nucl. Phys. A PD SEP 19 PY 1994 VL 577 IS 1-2 BP C233 EP C236 PG 4 WC Physics, Nuclear SC Physics GA PH686 UT WOS:A1994PH68600040 ER PT J AU SATO, T ODAGAWA, N OHTSUBO, H LEE, TSH AF SATO, T ODAGAWA, N OHTSUBO, H LEE, TSH TI NUCLEAR-STRUCTURE OF B-10 STUDIED WITH (E,E'),(PI,PI') AND (GAMMA,PI) REACTIONS SO NUCLEAR PHYSICS A LA English DT Article; Proceedings Paper CT International Symposium on Spin-Isospin Responses and Weak Processes in Hadrons and Nuclei CY MAR 08-10, 1994 CL SENRI LIFE SCI CTR, OSAKA, JAPAN SP MINIST EDUC SCI & CULTURE JAPAN HO SENRI LIFE SCI CTR ID ELECTRON-SCATTERING; PION-PHOTOPRODUCTION; POTENTIALS; MODEL AB We studied nuclear structure of B-10 using (e, e'),(pi, pi') and (gamma, pi) reactions under the distorted wave impulse approximation(DWIA). For this purpose the off-shell dependence of the amplitude was taken into account in the momentum space DWIA. We used the off-shell elementary amplitude of (pi,pi) and (gamma,pi) by the model of Nozawa, Blankleider and Lee[1]. The first order core polarization effects were incorporated with the p-shell wave functions of Cohen and Kurath and Hauge and Maripuu. It was shown that the core-polarization effects greatly improve the agreement with the experimental data and that the simultaneous study of these reactions is useful to probe the spin structure of p-shell nuclei. C1 ARGONNE NATL LAB,DIV PHYS,ARGONNE,IL 60439. RP SATO, T (reprint author), OSAKA UNIV,FAC SCI,DEPT PHYS,TOYONAKA,OSAKA 560,JAPAN. NR 18 TC 2 Z9 2 U1 0 U2 0 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0375-9474 J9 NUCL PHYS A JI Nucl. Phys. A PD SEP 19 PY 1994 VL 577 IS 1-2 BP C219 EP C224 PG 6 WC Physics, Nuclear SC Physics GA PH686 UT WOS:A1994PH68600038 ER PT J AU TADDEUCCI, TN AF TADDEUCCI, TN TI NUCLEAR ISOVECTOR SPIN RESPONSES FROM ((P)OVER-RIGHT-ARROW,(N)OVER-RIGHT-ARROW) REACTIONS AT 494 MEV SO NUCLEAR PHYSICS A LA English DT Article; Proceedings Paper CT International Symposium on Spin-Isospin Responses and Weak Processes in Hadrons and Nuclei CY MAR 08-10, 1994 CL SENRI LIFE SCI CTR, OSAKA, JAPAN SP MINIST EDUC SCI & CULTURE JAPAN HO SENRI LIFE SCI CTR ID POLARIZATION-TRANSFER; PROTON-SCATTERING; ELECTRON-SCATTERING; OBSERVABLES AB Complete sets of polarization transfer coefficients have been measured for quasifree (($) over right arrow p, ($) over right arrow n) scattering from H-2, C, and Ca at 494 MeV and scattering angles of 12.5 degrees, 18 degrees, and 27 degrees (q = 1.2, 1.7, 2.5 fm(-1)). These measurements yield separated transverse (sigma x q) and longitudinal (sigma . q) isovector spin responses. The transverse responses are in very good agreement with the responses measured in deep inelastic electron scattering. No significant enhancement or softening is observed in the longitudinal responses, in contrast to expectations based on an attractive pionic residual interaction. RP TADDEUCCI, TN (reprint author), LOS ALAMOS NATL LAB,POB 1663,LOS ALAMOS,NM 87545, USA. NR 20 TC 3 Z9 3 U1 0 U2 0 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0375-9474 J9 NUCL PHYS A JI Nucl. Phys. A PD SEP 19 PY 1994 VL 577 IS 1-2 BP C105 EP C110 PG 6 WC Physics, Nuclear SC Physics GA PH686 UT WOS:A1994PH68600021 ER PT J AU KASHLINSKY, A TKACHEV, II FRIEMAN, J AF KASHLINSKY, A TKACHEV, II FRIEMAN, J TI MICROWAVE BACKGROUND ANISOTROPY IN LOW-OMEGA(0) INFLATIONARY MODELS AND THE SCALE OF HOMOGENEITY IN THE UNIVERSE SO PHYSICAL REVIEW LETTERS LA English DT Article ID COSMOLOGICAL PERTURBATIONS; PREINFLATIONARY UNIVERSE; GALAXY; CLUSTERS; REMNANTS AB We study the microwave background anisotropy due to superhorizon-size perturbations in open universes with negative spatial curvature. Using results on the low-order temperature multipole moments from the Cosmic Background Explorer satellite, we find that if the homogeneity of the observable Universe arises from an early epoch of inflation, the present density parameter cannot differ from unity by more than the observed quadrupole anisotropy, \1 - Omega(0)\ less than or similar to Q similar or equal to 5 x 10(-6), assuming preinflationary density perturbations to be of order unity. With this assumption, inflation models with low Omega(0) either do not fit the microwave background observations or they do not solve the horizon problem. C1 FERMILAB NATL ACCELERATOR LAB,NASA,FERMILAB ASTROPHYS CTR,BATAVIA,IL 60510. RUSSIAN ACAD SCI,INST NUCL RES,MOSCOW 117312,RUSSIA. UNIV CHICAGO,DEPT ASTRON & ASTROPHYS,CHICAGO,IL 60637. RP KASHLINSKY, A (reprint author), NASA,GODDARD SPACE FLIGHT CTR,CODE 685,GREENBELT,MD 20771, USA. NR 36 TC 41 Z9 41 U1 0 U2 0 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 0031-9007 J9 PHYS REV LETT JI Phys. Rev. Lett. PD SEP 19 PY 1994 VL 73 IS 12 BP 1582 EP 1585 DI 10.1103/PhysRevLett.73.1582 PG 4 WC Physics, Multidisciplinary SC Physics GA PG522 UT WOS:A1994PG52200005 ER PT J AU GILKES, ML ALBERGO, S BIESER, F BRADY, FP CACCIA, Z CEBRA, DA CHACON, AD CHANCE, JL CHOI, Y COSTA, S ELLIOTT, JB HAUGER, JA HIRSCH, AS HJORT, EL INSOLIA, A JUSTICE, M KEANE, D KINTNER, JC LINDENSTRUTH, V LISA, MA LYNEN, U MATIS, HS MCMAHAN, M MCPARLAND, C MULLER, WFJ OLSON, DL PARTLAN, MD PORILE, NT POTENZA, R RAI, G RASMUSSEN, J RITTER, HG ROMANSKI, J ROMERO, JL RUSSO, GV SANN, H SCHARENBERG, R SCOTT, A SHAO, Y SRIVASTAVA, BK SYMONS, TJM TINCKNELL, M TUVE, C WANG, S WARREN, P WIEMAN, HH WOLF, K AF GILKES, ML ALBERGO, S BIESER, F BRADY, FP CACCIA, Z CEBRA, DA CHACON, AD CHANCE, JL CHOI, Y COSTA, S ELLIOTT, JB HAUGER, JA HIRSCH, AS HJORT, EL INSOLIA, A JUSTICE, M KEANE, D KINTNER, JC LINDENSTRUTH, V LISA, MA LYNEN, U MATIS, HS MCMAHAN, M MCPARLAND, C MULLER, WFJ OLSON, DL PARTLAN, MD PORILE, NT POTENZA, R RAI, G RASMUSSEN, J RITTER, HG ROMANSKI, J ROMERO, JL RUSSO, GV SANN, H SCHARENBERG, R SCOTT, A SHAO, Y SRIVASTAVA, BK SYMONS, TJM TINCKNELL, M TUVE, C WANG, S WARREN, P WIEMAN, HH WOLF, K TI DETERMINATION OF CRITICAL EXPONENTS FROM THE MULTIFRAGMENTATION OF GOLD NUCLEI SO PHYSICAL REVIEW LETTERS LA English DT Article ID PERCOLATION CLUSTERS; COLLISIONS; YIELDS AB Using reverse kinematics, we have studied the breakup of 1.0A GeV gold nuclei incident on a carbon target. The detector system permitted exclusive event reconstruction of nearly all charged reaction nuclear matter possesses a critical point observable in finite nuclei. We have determined values for the critical exponents gamma, beta, and tau. These values are close to those for liquid-gas systems and clearly different than those for 3D percolation and the liquid-gas mean field limit. C1 UNIV CATANIA,I-95129 CATANIA,ITALY. IST NAZL FIS NUCL,I-95129 CATANIA,ITALY. UNIV CALIF DAVIS,DAVIS,CA 95616. GESELL SCHWERIONENFORSCH MBH,D-64220 DARMSTADT,GERMANY. KENT STATE UNIV,KENT,OH 44242. UNIV CALIF BERKELEY,LAWRENCE BERKELEY LAB,DIV NUCL SCI,BERKELEY,CA 94720. TEXAS A&M UNIV,COLLEGE STN,TX 77843. RP GILKES, ML (reprint author), PURDUE UNIV,W LAFAYETTE,IN 47907, USA. RI Insolia, Antonio/M-3447-2015; TUVE', Cristina/P-3933-2015 OI Insolia, Antonio/0000-0002-9040-1566; TUVE', Cristina/0000-0003-0739-3153 NR 15 TC 183 Z9 189 U1 0 U2 6 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 0031-9007 J9 PHYS REV LETT JI Phys. Rev. Lett. PD SEP 19 PY 1994 VL 73 IS 12 BP 1590 EP 1593 DI 10.1103/PhysRevLett.73.1590 PG 4 WC Physics, Multidisciplinary SC Physics GA PG522 UT WOS:A1994PG52200007 ER PT J AU BLINOV, BB CHU, CM COURANT, ED CRANDELL, DA KAUFMAN, WA KRISCH, AD NURUSHEV, TS PHELPS, RA RACZKOWSKI, DB RATNER, LG WONG, VK CAUSSYN, DD DERBENEV, YS ELLISON, TJP LEE, SY RINCKEL, T SCHWANDT, P SPERISEN, F STEPHENSON, EJ VONPRZEWOSKI, B BAIOD, R MINTY, MG OHMORI, C WIENANDS, U AF BLINOV, BB CHU, CM COURANT, ED CRANDELL, DA KAUFMAN, WA KRISCH, AD NURUSHEV, TS PHELPS, RA RACZKOWSKI, DB RATNER, LG WONG, VK CAUSSYN, DD DERBENEV, YS ELLISON, TJP LEE, SY RINCKEL, T SCHWANDT, P SPERISEN, F STEPHENSON, EJ VONPRZEWOSKI, B BAIOD, R MINTY, MG OHMORI, C WIENANDS, U TI FIRST TEST OF A PARTIAL SIBERIAN SNAKE DURING POLARIZED BEAM ACCELERATION SO PHYSICAL REVIEW LETTERS LA English DT Article ID DEPOLARIZING RESONANCES AB We recently studied the first acceleration of a spin-polarized beam through a depolarizing resonance using a partial Siberian snake. We accelerated polarized protons from 95 to 140 MeV while ramping a 10% partial Siberian snake along with the acceleration cycle. The 10% partial snake suppressed all observable depolarization due to the G gamma = 2 imperfection depolarizing resonance which occurred near 108 MeV during acceleration. However, 20% and 30% partial Siberian snakes apparently moved the G gamma = 7 - nu(y) intrinsic depolarizing resonance from near 177 MeV into our energy range; this caused some interesting but not-yet fully understood depolarization. C1 INDIANA UNIV,CYCLOTRON FACIL,BLOOMINGTON,IN 47408. FERMILAB NATL ACCELERATOR LAB,BATAVIA,IL 60510. UNIV TOKYO,INST NUCL STUDY,TANASHI,TOKYO 188,JAPAN. STANFORD LINEAR ACCELERATOR CTR,STANFORD,CA 94309. SUPERCONDUCTING SUPER COLLIDER LAB,DALLAS,TX. MOSCOW MV LOMONOSOV STATE UNIV,MOSCOW,RUSSIA. BROOKHAVEN NATL LAB,BROOKHAVEN,NY 11973. UNIV MICHIGAN,OFF PROVOST,FLINT,MI 48501. UNIV MICHIGAN,DEPT NUCL ENGN,ANN ARBOR,MI 48109. RP BLINOV, BB (reprint author), UNIV MICHIGAN,RANDALL LAB PHYS,ANN ARBOR,MI 48109, USA. NR 15 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 0031-9007 J9 PHYS REV LETT JI Phys. Rev. Lett. PD SEP 19 PY 1994 VL 73 IS 12 BP 1621 EP 1623 DI 10.1103/PhysRevLett.73.1621 PG 3 WC Physics, Multidisciplinary SC Physics GA PG522 UT WOS:A1994PG52200015 ER PT J AU SHAN, XW MONTGOMERY, D AF SHAN, XW MONTGOMERY, D TI MAGNETOHYDRODYNAMIC STABILIZATION THROUGH ROTATION SO PHYSICAL REVIEW LETTERS LA English DT Article ID HARTMANN-NUMBER; TEARING MODES; TOKAMAK; TRANSITION; STATES AB Rotation of a cylinder of current-carrying magnetofluid is shown to stabilize it against helical magnetohydrodynamic activity, much as rotation can ''stiffen'' a Navier-Stokes fluid. The (viscous, resistive) magnetofluid is in a periodic cylinder bounded by a rigid wall; it contains an externally supported axial magnetic flux and a driven axial current. The suppressed activity is that known to result in paired helical vortices and helical current-channel distortions. The method used is fully three-dimensional, spectral-method computation. The stabilization is global and not confined to the outer edge of the plasma. C1 DARTMOUTH COLL, DEPT PHYS & ASTRON, HANOVER, NH 03755 USA. RP LOS ALAMOS NATL LAB, CTR NONLINEAR STUDIES, LOS ALAMOS, NM 87545 USA. RI Shan, Xiaowen/H-2836-2013 OI Shan, Xiaowen/0000-0002-6350-9248 NR 19 TC 20 Z9 21 U1 1 U2 4 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 SEP 19 PY 1994 VL 73 IS 12 BP 1624 EP 1627 DI 10.1103/PhysRevLett.73.1624 PG 4 WC Physics, Multidisciplinary SC Physics GA PG522 UT WOS:A1994PG52200016 ER PT J AU RODRIGUEZ, JP AF RODRIGUEZ, JP TI OBSERVABLE ZERO SOUND IN STRONGLY CORRELATED METALS SO PHYSICAL REVIEW LETTERS LA English DT Article ID T-J MODEL; VALENCE-BOND STATE; MEAN-FIELD-THEORY; PHASE-DIAGRAM; SUPERCONDUCTIVITY; LA2CUO4; FERMIONS AB The slow zero-sound mode expected near the Mott transition in strongly interacting two-dimensional Fermi systems that are neutral is shown to persist as the physical sound mode in the case that the fermion carries electronic charge and is embedded in a positive ionic background. The latter sound velocity softens completely precisely at the Mott transition, indicating that a zone-center structural transition will occur in the system. We suggest that this phonon-softening mechanism is related to the structural transitions commonly observed in the oxide superconductors. C1 CALIF STATE UNIV LOS ANGELES,DEPT PHYS & ASTRON,LOS ANGELES,CA 90032. RP RODRIGUEZ, JP (reprint author), LOS ALAMOS NATL LAB,DIV THEORET,LOS ALAMOS,NM 87545, USA. NR 29 TC 2 Z9 2 U1 0 U2 0 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 0031-9007 J9 PHYS REV LETT JI Phys. Rev. Lett. PD SEP 19 PY 1994 VL 73 IS 12 BP 1675 EP 1678 DI 10.1103/PhysRevLett.73.1675 PG 4 WC Physics, Multidisciplinary SC Physics GA PG522 UT WOS:A1994PG52200029 ER PT J AU BOUKHNY, M BULLOCK, GL SHIVARAM, BS HINKS, DG AF BOUKHNY, M BULLOCK, GL SHIVARAM, BS HINKS, DG TI TETRACRITICAL POINTS AND THE SUPERCONDUCTING PHASES OF UPT3 - UNIAXIAL PRESSURE EFFECTS SO PHYSICAL REVIEW LETTERS LA English DT Article ID UNCONVENTIONAL SUPERCONDUCTIVITY; DOUBLE TRANSITION; ORDER-PARAMETER; MAGNETIC-FIELD; DIAGRAM; DEPENDENCE AB Using signatures in the longitudinal sound velocity we have mapped for the first time experimentally the pressure dependence of the phase boundaries in superconducting UPt3 for magnetic field H parallel to the a axis. With increasing pressure P-c parallel to the c axis, the tetracritical point in the H-T plane is observed to shift to lower H and higher temperature T. At a critical stress, P-c similar to 2.6 kbar the tetracritical point reaches the H = O, P-c - T plane, and our measurements prove coexistence of at least four phases in this plane as well. C1 ARGONNE NATL LAB,DIV MAT SCI,ARGONNE,IL 60439. RP BOUKHNY, M (reprint author), UNIV VIRGINIA,JESSE W BEAMS LAB PHYS,CHARLOTTESVILLE,VA 22901, USA. NR 41 TC 30 Z9 30 U1 0 U2 5 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 0031-9007 J9 PHYS REV LETT JI Phys. Rev. Lett. PD SEP 19 PY 1994 VL 73 IS 12 BP 1707 EP 1710 DI 10.1103/PhysRevLett.73.1707 PG 4 WC Physics, Multidisciplinary SC Physics GA PG522 UT WOS:A1994PG52200037 ER PT J AU LILL, TB CALLAWAY, WF PELLIN, MJ GRUEN, DM AF LILL, TB CALLAWAY, WF PELLIN, MJ GRUEN, DM TI ABUNDANCE AND DEPTH OF ORIGIN OF NEUTRAL AND IONIC CLUSTERS SPUTTERED FROM A LIQUID GALLIUM-INDIUM EUTECTIC ALLOY SO PHYSICAL REVIEW LETTERS LA English DT Article ID ELECTRONIC SHELL STRUCTURE; MASS DISTRIBUTIONS; ATOMS; BOMBARDMENT; DEPENDENCE; IONIZATION; EMISSION; SILVER; ENERGY AB Neutral and positively charged clusters produced by 4 keV Ar+ ion bombardment of a liquid gallium-indium eutectic alloy have been studied by time-of-flight mass spectrometry coupled with single photon postionization of the neutrals. The abundance distributions for clusters with equal nuclearity are statistical. They confirm a strong indium surface segregation. An increasing gallium content, and therefore, larger depth of origin, was found for increasing cluster size. C1 ARGONNE NATL LAB,DIV CHEM TECHNOL,ARGONNE,IL 60439. ARGONNE NATL LAB,DIV CHEM,ARGONNE,IL 60439. RP LILL, TB (reprint author), ARGONNE NATL LAB,DIV MAT SCI,9700 S CASS AVE,ARGONNE,IL 60439, USA. RI Pellin, Michael/B-5897-2008 OI Pellin, Michael/0000-0002-8149-9768 NR 27 TC 19 Z9 19 U1 0 U2 2 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 0031-9007 J9 PHYS REV LETT JI Phys. Rev. Lett. PD SEP 19 PY 1994 VL 73 IS 12 BP 1719 EP 1722 DI 10.1103/PhysRevLett.73.1719 PG 4 WC Physics, Multidisciplinary SC Physics GA PG522 UT WOS:A1994PG52200040 ER PT J AU KONNO, H LOMDAHL, PS AF KONNO, H LOMDAHL, PS TI STATISTICAL-MECHANICS OF SOLITON CREATION AND ANNIHILATION IN A DRIVEN NONLINEAR SCHRODINGER-EQUATION SO PHYSICS LETTERS A LA English DT Article ID CHAOS AB We report numerical and theoretical results for the statistical mechanics of annihilation and creation processes of soliton-like pulses in a dissipative nonlinear Schrodinger equation driven strongly by an external sinusoidal force. It is shown by analyzing statistical mechanical quantities and a phenomenological stochastic theory that the soliton annihilation/creation process has sub-Poissonian character and is dominated by two-''solitons'' and large amplitude radiation. C1 SANTA FE INST,SANTA FE,NM 87501. UNIV TSUKUBA,INST MAT SCI,TSUKUBA,IBARAKI 305,JAPAN. RP KONNO, H (reprint author), LOS ALAMOS NATL LAB,LOS ALAMOS,NM 87545, USA. NR 18 TC 5 Z9 5 U1 2 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 SEP 19 PY 1994 VL 193 IS 1 BP 35 EP 41 DI 10.1016/0375-9601(94)00643-1 PG 7 WC Physics, Multidisciplinary SC Physics GA PH171 UT WOS:A1994PH17100008 ER PT J AU ALEKSEEV, KN BERMAN, GP CAMPBELL, DK AF ALEKSEEV, KN BERMAN, GP CAMPBELL, DK TI DYNAMICAL INSTABILITIES AND DETERMINISTIC CHAOS IN BASSISTIC ELECTRON MOTION IN SEMICONDUCTOR SUPERLATTICES SO PHYSICS LETTERS A LA English DT Article ID BLOCH OSCILLATIONS AB We consider the motion of ballistic electrons within a superlattice miniband under the influence of an alternating electric field. We show that the interaction of electrons with the self-consistent electromagnetic field generated by the electron current may lead to the transition from regular to chaotic dynamics. We estimate the conditions for the experimental observation of this deterministic chaos and discuss the similarities of the superlattice system with the other condensed matter and quantum optical systems. C1 KRASNOYARSK STATE UNIV,KIRENSKY INST PHYS,RES & EDUC CTR NONLINEAR PROC,DEPT THEORET,KRASNOYARSK 660036,RUSSIA. UNIV ILLINOIS,DEPT PHYS,URBANA,IL 61801. RP ALEKSEEV, KN (reprint author), LANL,CNLS,MS-B258,LOS ALAMOS,NM 87545, USA. NR 29 TC 10 Z9 10 U1 0 U2 0 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0375-9601 J9 PHYS LETT A JI Phys. Lett. A PD SEP 19 PY 1994 VL 193 IS 1 BP 54 EP 60 DI 10.1016/0375-9601(94)00641-5 PG 7 WC Physics, Multidisciplinary SC Physics GA PH171 UT WOS:A1994PH17100012 ER PT J AU MCCALLEN, DB AF MCCALLEN, DB TI COMPUTER-SIMULATION OF LARGE FRAME STRUCTURES SO COMPUTERS & STRUCTURES LA English DT Article ID LATTICE STRUCTURES; CONTINUUM MODEL; ELEMENT AB A weapon test canister frame provides a structural platform for a weapon device and associated diagnostic instrumentation. The underground environment in which a test canister is placed results in the canister being subjected to large static loads. Excessive canister deflection under load may result in misalignment of optical lines-of-sight, with resulting degradation of the quality of the experimental physics data which is obtained. Each weapon test costs tens of millions of dollars and takes months or years to design and construct, and thus it is essential that the canister structure maintains functionality and prevents excessive deformation under load. In the current paper, a discussion of computer modeling and model verification for canister structures is presented. Two different approaches for performing computer simulation of the response of canister structures are discussed. One approach consists of a brute force detailed finite element model in which a classical finite element technique is employed to model the structure in great detail. The second approach employs a reduced-order, equivalent continuum model to represent the canister structure. The continuum model is based on a special purpose methodology which allows representation of the global behavior of large canister structures with an efficient and economical model. Canister modeling results for both modeling approaches are presented in this paper and compared to experimental data from actual canister tests. Finally, the utility of numerical simulations in identifying an effective technique for canister frame stiffening is discussed. RP MCCALLEN, DB (reprint author), LAWRENCE LIVERMORE NATL LAB,LIVERMORE,CA 94550, USA. NR 16 TC 0 Z9 0 U1 0 U2 0 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD, ENGLAND OX5 1GB SN 0045-7949 J9 COMPUT STRUCT JI Comput. Struct. PD SEP 17 PY 1994 VL 52 IS 6 BP 1145 EP 1160 DI 10.1016/0045-7949(94)90181-3 PG 16 WC Computer Science, Interdisciplinary Applications; Engineering, Civil SC Computer Science; Engineering GA PJ563 UT WOS:A1994PJ56300006 ER PT J AU EVLETH, EM AKACEM, Y COLVIN, M AF EVLETH, EM AKACEM, Y COLVIN, M TI COMPARISON OF AB-INITIO AND AMSOL SEMIEMPIRICAL FREE-ENERGIES OF SOLVATION OF 3RD-ROW SPECIES SO CHEMICAL PHYSICS LETTERS LA English DT Article ID NEUTRAL MOLECULES; AQUEOUS-SOLUTION; GAS-PHASE; HYDRATION; CONTINUUM; THERMODYNAMICS; POTENTIALS; FRAMEWORK; CATIONS; ANIONS AB A comparative study of ab initio and AMSOL semiempirical continuum modeling of aqueous free energies of solvation shows that the AM1 and PM3 parameterizations yield unreasonable values for structures containing oxyphosphorous groups as well as some other third-row elements. The experimental estimations of the aqueous free energies of solvation of sulfuric and nitric acids are -23 and -11 kcal/mol, respectively. The value for sulfuric acid is considerably more negative than found for other neutral substances and is approximated in the ab initio calculation. C1 SANDIA NATL LABS,CTR COMPUTAT ENGN,LIVERMORE,CA 94551. RP EVLETH, EM (reprint author), UNIV PARIS 06,DYNAMIQUE INTERACT MOLEC LAB ER271,4 PL JUSSIEU,F-75230 PARIS 05,FRANCE. NR 34 TC 8 Z9 8 U1 0 U2 0 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0009-2614 J9 CHEM PHYS LETT JI Chem. Phys. Lett. PD SEP 16 PY 1994 VL 227 IS 4-5 BP 412 EP 418 DI 10.1016/0009-2614(94)00864-7 PG 7 WC Chemistry, Physical; Physics, Atomic, Molecular & Chemical SC Chemistry; Physics GA PG254 UT WOS:A1994PG25400008 ER PT J AU TONETTI, DA HENNINGCHUBB, C YAMANISHI, DT HUBERMAN, E AF TONETTI, DA HENNINGCHUBB, C YAMANISHI, DT HUBERMAN, E TI PROTEIN-KINASE C-BETA IS REQUIRED FOR MACROPHAGE DIFFERENTIATION OF HUMAN HL-60 LEUKEMIA-CELLS SO JOURNAL OF BIOLOGICAL CHEMISTRY LA English DT Article ID PHORBOL ESTER; MONOCYTIC DIFFERENTIATION; TERMINAL DIFFERENTIATION; GENE-EXPRESSION; RETINOIC ACID; INDUCTION; RESISTANT; PHORBOL-12-MYRISTATE-13-ACETATE; TRANSLOCATION; DIESTER AB The requirement for protein kinase C (PKC)-beta in phorbol 12-myristate 13-acetate (PMA)-induced macrophage differentiation of human HL-60 promyelocytic leukemia cells was studied by using the variant HL-525, which is deficient in PKC-beta and is resistant to PMA-induced differentiation. Transfecting these resistant HL-525 cells with expression vectors containing either PKC-beta I or PKC-beta II cDNA resulted in clones that displayed PKC-beta transcript levels similar to or higher than those of the parental HL-60 cells or cells from a PMA-susceptible HL 60 clone, HL-205. These productive transfectants also exhibited PMA-induced cell attachment and spreading, inhibition of cell replication, reactivity to the OKM1 monoclonal antibody, and the ability to phagocytize opsinized beads, which are all characteristic macrophage markers. No PMA-induced differentiation markers were observed in any of the PKC-beta I or PKC-beta II transfectants that did not exhibit an increased PKC-beta RNA level or in cells transfected with control plasmids. These results indicate that restoration of the PKC-beta isozyme deficiency by productive gene transfection causes HL-525 cells to revert to a phenotype like that of the parental HL-60 cells, which is characterized by susceptibility to PMA-induced macrophage differentiation. Therefore, we can conclude that PKC-beta is one of the essential elements in the PMA-induced signal transduction pathway which leads to macrophage differentiation in HL-60 cells and perhaps in other related cell types, C1 ARGONNE NATL LAB,CTR MECHANIST BIOL & BIOTECHNOL,ARGONNE,IL 60439. UNIV CALIF IRVINE,DEPT MED,DIV HEMATOL ONCOL,IRVINE,CA 92717. NR 43 TC 110 Z9 112 U1 0 U2 1 PU AMER SOC BIOCHEMISTRY MOLECULAR BIOLOGY INC PI BETHESDA PA 9650 ROCKVILLE PIKE, BETHESDA, MD 20814 SN 0021-9258 J9 J BIOL CHEM JI J. Biol. Chem. PD SEP 16 PY 1994 VL 269 IS 37 BP 23230 EP 23235 PG 6 WC Biochemistry & Molecular Biology SC Biochemistry & Molecular Biology GA PQ164 UT WOS:A1994PQ16400051 PM 8083228 ER PT J AU SLATKIN, DN AF SLATKIN, DN TI GLIOBLASTOMA TREATMENT SO SCIENCE LA English DT Letter RP SLATKIN, DN (reprint author), BROOKHAVEN NATL LAB,CLIN RES CTR,POB 5000,UPTON,NY 11973, USA. NR 1 TC 1 Z9 1 U1 1 U2 1 PU AMER ASSOC ADVANCEMENT SCIENCE PI WASHINGTON PA 1200 NEW YORK AVE, NW, WASHINGTON, DC 20005 SN 0036-8075 J9 SCIENCE JI Science PD SEP 16 PY 1994 VL 265 IS 5179 BP 1644 EP 1644 DI 10.1126/science.7993457 PG 1 WC Multidisciplinary Sciences SC Science & Technology - Other Topics GA PG284 UT WOS:A1994PG28400005 PM 7993457 ER PT J AU MARTINEAU, D DEGUISE, S FOURNIER, M SHUGART, L GIRARD, C LAGACE, A BELAND, P AF MARTINEAU, D DEGUISE, S FOURNIER, M SHUGART, L GIRARD, C LAGACE, A BELAND, P TI PATHOLOGY AND TOXICOLOGY OF BELUGA WHALES FROM THE ST-LAWRENCE ESTUARY, QUEBEC, CANADA - PAST, PRESENT AND FUTURE SO SCIENCE OF THE TOTAL ENVIRONMENT LA English DT Article; Proceedings Paper CT International Symposium on Marine Pollution - Mammals and Toxic Contaminants/5th Annual International Symposium of the International-Marine-Biological-Research-Institute CY FEB 06-08, 1993 CL KAMOGAWA, JAPAN SP INT MARINE BIOL RES INST DE BELUGA; CANCER; CETACEANS; CONTAMINANTS; DDT; IMMUNOSUPPRESSION; ORGANOCHLORINE; PATHOLOGY; PCB; POLYCYCLIC AROMATIC; HYDROCARBONS; WHALES ID HALOGENATED AROMATIC-HYDROCARBONS; HUMAN LYMPHOCYTES-T; POLYCHLORINATED-BIPHENYLS; DELPHINAPTERUS-LEUCAS; MERCURY POLLUTION; COVALENT BINDING; RHESUS-MONKEYS; MACACA-MULATTA; SAGUENAY FJORD; ADRENAL-GLAND AB An indigenous population of 450-500 beluga whales (Delphinapterus leucas) inhabiting the St. Lawrence Estuary has been exposed chronically for more than 50 years to a complex mixture of industrial pollutants including organochlorinated compounds (OC), polycyclic aromatic hydrocarbons (PAH) and heavy metals. From 1983 to 1990, we have necropsied 45 well preserved carcasses out of a total of 120 beluga whales reported dead over this period. Of these 45 animals, nine were affected by 10 malignant neoplasms. Fifteen animals (33%) were affected by pneumonia. Milk production was compromised in eight of 17 mature females (41%), by inflammatory changes (seven animals) and cancer (one animal) which affected the mammary glands. Opportunistic bacteria were found in pure culture, and/or in significant amounts in at least two organs in 20 belugas (44%). The concentrations of both total PCBs and highly chlorinated PCB congeners were much higher in St. Lawrence animals than in Arctic beluga whales. OC-induced immunosuppression has been repeatedly demonstrated in a wide variety of animal species. Therefore, it is probable that the immune functions of St. Lawrence beluga whales are impaired. Benzo[alpha]pyrene adducts were detected in 10 of the 11 St. Lawrence beluga whales of which tissues (six livers, 10/11 brains) were analyzed by a method based on HPLC. No such adducts were found in four Arctic animals. Since benzo[alpha]pyrene is one of the most potent chemical carcinogens known to man, these compounds might be responsible for some of the cancers observed in that population. Overall, our findings contrast vividly with those of others who found that cancers are exceedingly rare in free-ranging odontocete populations and that the major causes for mortalities in these populations are bacteria, parasites, and trauma. C1 UNIV QUEBEC,DEPT SCI BIOL,MONTREAL H3C 3P8,QUEBEC,CANADA. INST NATL ECOTOXICOL ST LAURENT,MONTREAL H2L 3M6,PQ,CANADA. OAK RIDGE NATL LAB,DIV ENVIRONM SCI,OAK RIDGE,TN 37831. RP MARTINEAU, D (reprint author), UNIV MONTREAL,FAC MED VET,DEPT MICROBIOL & PATHOL,ST HYACINTHE J2S 7C6,QUEBEC,CANADA. NR 100 TC 106 Z9 108 U1 11 U2 47 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0048-9697 J9 SCI TOTAL ENVIRON JI Sci. Total Environ. PD SEP 16 PY 1994 VL 154 IS 2-3 BP 201 EP 215 DI 10.1016/0048-9697(94)90088-4 PG 15 WC Environmental Sciences SC Environmental Sciences & Ecology GA PF441 UT WOS:A1994PF44100008 PM 7973607 ER PT J AU LOVELY, RH BUSCHBOM, RL SLAVICH, AL ANDERSON, LE HANSEN, NH WILSON, BW AF LOVELY, RH BUSCHBOM, RL SLAVICH, AL ANDERSON, LE HANSEN, NH WILSON, BW TI ADULT LEUKEMIA RISK AND PERSONAL APPLIANCE USE - A PRELIMINARY-STUDY SO AMERICAN JOURNAL OF EPIDEMIOLOGY LA English DT Article DE ADULT; ELECTROMAGNETIC FIELDS; HOUSEHOLD PRODUCTS; LEUKEMIA, NONLYMPHOCYTIC, ACUTE ID ELECTRICAL WIRING CONFIGURATIONS; 60-HZ MAGNETIC-FIELDS; CHILDHOOD-CANCER; RESIDENTIAL EXPOSURE AB The hypothesis that use of personal electric appliances may be associated with increased risk of acute nonlymphocytic leukemia in adults was tested using interview data from a previously completed case-control study of 114 cases and 133 controls conducted between 1981 and 1984. Cases were obtained from a population-based cancer registry in western Washington state, and controls were obtained from the same area by random digit dialing. Of 32 electrical home appliances for which data on use were available for adult acute nonlymphocytic leukemia cases and controls, three motor-driven personal appliances (electric razors, hair dryers, and massage units) were selected a priori because their use represents exposure to higher peak magnetic fields than that from most other home appliances. When compared on an ''ever used'' versus ''never used'' basis, use of one or more of these appliances was not associated with increased risk of leukemia in the population studied (odds ratio (OR) = 0.71, 95% confidence interval (CI) 0.41-1.24). When the appliances were considered individually, massage units were more likely to have been used by cases than by controls (OR = 3.00, 95% CI 1.43-6.32), while hair dryers were more likely to have been used by controls than cases (OR = 0.38, 95% CI 0.22-0.66). There was a nonsignificant tendency for electric razor use to differentiate the cases from controls (OR = 1.33, 95% CI 0.80-2.23). When reported daily time of use was stratified, there was no overall increased risk with increased time of use except for electric razors (p < 0.05). In addition to the analysis of appliance use data from the case-control study, the authors obtained several models of these motor-driven personal appliances and characterized the magnetic fields they produce. Magnetic field flux density, or the B-field, and spectral measurements showed that partial body exposure from such appliances may exceed 0.5 mTesla (root mean squared) at rates-of-change exceeding 10 Tesla/sec. These epidemiologic data must be interpreted cautiously because the number of cases is limited and because of proxy reporting of appliance use for deceased cases. Nevertheless, the authors believe these data indicate that peak magnetic field exposure from personal appliances warrants further investigation as a possible risk factor for acute nonlymphocytic leukemia in adults. C1 PACIFIC NW LAB, RICHLAND, WA USA. RP LOVELY, RH (reprint author), BATTELLE SEATTLE RES CTR, NE 41ST ST, SEATTLE, WA 98105 USA. NR 18 TC 19 Z9 19 U1 0 U2 0 PU JOHNS HOPKINS UNIV SCHOOL HYGIENE PUB HEALTH PI BALTIMORE PA 111 MARKET PLACE, STE 840, BALTIMORE, MD 21202-6709 SN 0002-9262 J9 AM J EPIDEMIOL JI Am. J. Epidemiol. PD SEP 15 PY 1994 VL 140 IS 6 BP 510 EP 517 PG 8 WC Public, Environmental & Occupational Health SC Public, Environmental & Occupational Health GA PG136 UT WOS:A1994PG13600003 PM 8067344 ER PT J AU GOTO, T KENNEL, SJ ABE, M TAKISHITA, M KOSAKA, M SOLOMON, A SAITO, S AF GOTO, T KENNEL, SJ ABE, M TAKISHITA, M KOSAKA, M SOLOMON, A SAITO, S TI A NOVEL MEMBRANE ANTIGEN SELECTIVELY EXPRESSED ON TERMINALLY DIFFERENTIATED HUMAN B-CELLS SO BLOOD LA English DT Article ID HUMAN-PLASMA-CELLS; HUMAN-BONE-MARROW; MULTIPLE-MYELOMA; MONOCLONAL-ANTIBODIES; CIRCULATING LYMPHOCYTES; PERIPHERAL-BLOOD; LINEAGE; IDENTIFICATION; HETEROGENEITY; GLYCOPROTEIN AB A monoclonal antibody (MoAb) that defines a novel terminal B-cell-restricted antigen, termed HM1.24, was developed against a human plasma cell line. The MoAb, designated anti-HM1.24, reacted with five different human myeloma cell lines, as well as with monoclonal neoplastic plasma cells obtained from the bone marrow or peripheral blood of patients with multiple myeloma or Waldenstrom's macroglobulinemia. The HM1.24 antigen was also expressed by mature Ig-secreting B cells (plasma cells and lymphoplasmacytoid cells) but not by other cells contained in the peripheral blood, bone marrow, liver, spleen, kidney, or heart of normal individuals or patients with non-plasma-cell-related malignancies. The anti-HM1.24 MoAb bound to human myeloma RPMI 8226 cells with an affinity constant of 9.2 x 10(8) M(-1), indicating similar to 84,000 sites/cell. By immunoprecipitation assay under reducing conditions, this MoAb identified a membrane glycoprotein that had a molecular weight of 29 to 33 kD. Our studies indicate that the HM1.24-related protein represents a specific marker of late-stage B-cell maturation and potentially serves as a target antigen for the immunotherapy of multiple myeloma and related plasma cell dyscrasias. (C) 1994 by The American Society of Hematology. C1 OAK RIDGE NATL LAB,DIV BIOL,KNOXVILLE,TN. UNIV TENNESSEE,MED CTR,GRAD SCH MED,KNOXVILLE,TN. UNIV TENNESSEE,MED CTR,DEPT MED,HUMAN IMMUNOL & CANC PROGRAM,KNOXVILLE,TN. RP GOTO, T (reprint author), UNIV TOKUSHIMA,SCH MED,DEPT INTERNAL MED 1,3-8-15 KURAMOTO CHO,TOKUSHIMA 770,JAPAN. FU NCI NIH HHS [CA10056] NR 49 TC 136 Z9 139 U1 0 U2 6 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 SEP 15 PY 1994 VL 84 IS 6 BP 1922 EP 1930 PG 9 WC Hematology SC Hematology GA PG388 UT WOS:A1994PG38800028 PM 8080996 ER PT J AU DEES, C TRAVIS, C AF DEES, C TRAVIS, C TI HYPERPHOSPHORYLATION OF P53 INDUCED BY BENZENE, TOLUENE, AND CHLOROFORM SO CANCER LETTERS LA English DT Article DE P53; TUMOR PROMOTER; PROTEIN KINASE C; PHOSPHORYLATION ID PROTEIN-KINASE-C; WILD-TYPE P53; TUMOR PROMOTER AB Phorbol 12-myristate, 13-acetate (PMA) is a known protein kinase C activator (PKC); benzene, chloroform, and toluene have also been reported to be PKC activators. We examined the effects of these three solvents on the phosphorylation of p53 in treated cells. Hyperphosphorylated p53 was found when p53 was immunoprecipitated from rat liver epithelial cell extracts treated with any of the solvents or PMA. The solvents also resulted in hyper-phosphorylation of human p53 produced by transfection of Saos-2 cells with a eucaryotic expression vector. Increased phosphorylation of p53 induced by the solvents was also observed through in vitro assays. Hyperphosphoryation of p53 may be involved in tumor promotion by benzene, toluene and chloroform. RP DEES, C (reprint author), OAK RIDGE NATL LAB,DIV HLTH SCI RES,RISK ANAL SECT,MOLEC TOXICOL GRP,BLDG 4500 MS-6109,POB 2008,OAK RIDGE,TN 37831, USA. NR 17 TC 14 Z9 15 U1 0 U2 0 PU ELSEVIER SCI IRELAND LTD PI CLARE PA CUSTOMER RELATIONS MANAGER, BAY 15, SHANNON INDUSTRIAL ESTATE CO, CLARE, IRELAND SN 0304-3835 J9 CANCER LETT JI Cancer Lett. PD SEP 15 PY 1994 VL 84 IS 2 BP 117 EP 123 DI 10.1016/0304-3835(94)90365-4 PG 7 WC Oncology SC Oncology GA PG262 UT WOS:A1994PG26200002 PM 8076368 ER PT J AU BLANK, DA NORTH, SW LEE, YT AF BLANK, DA NORTH, SW LEE, YT TI THE ULTRAVIOLET PHOTODISSOCIATION DYNAMICS OF PYRROLE SO CHEMICAL PHYSICS LA English DT Article ID FUEL-NITROGEN; SHOCK-TUBE; CYCLOPENTADIENE; ISOMERIZATION; PYROLYSIS; NM AB Photofragment translational spectroscopy was used to study the photodissociation of pyrrole at 193 and 248 nm under collision-free conditions. Five primary dissociation channels were observed at 193 nm. Two channels resulted from cleavage of the N-H bond to yield H + pyrrolyl radical with one channel following internal conversion (IC) to the ground state (almost-equal-to 21%) and the other originating from electronically excited pyrrole (almost-equal-to 30%). Two dissociation channels involved elimination of HCN following IC. One channel producing HCN + vinylmethylene (almost-equal-to 25%) following ring opening and hydrogen migration and the other proceeding via a bridged 3H-pyrrole intermediate to form HCN + cyclopropene (almost-equal-to 24%). The last channel at 193 nm involved IC to the ground state followed by ring opening and N-C bond cleavage to form NH + CHCCHCH2 (<1%). At 248 nm three dissociation channels were observed, all of which involved the elimination of atomic hydrogen. Analogous to the results at 193 nm, two of these channels resulted from cleavage of the N-H bond with one channel following IC (almost-equal-to 42%) and the other dissociating from an excited electronic state (almost-equal-to 47%). The third dissociation channel at 248 nm involved the cleavage of one of the two C-H bonds in electronically excited pyrrole (almost-equal-to 11%). Translational energy distributions were determined for all observed dissociation channels. From consideration of the maximum translational energy of the photofragments D0(N-H) = 88+/-2 kcal/mol, D0(C-H) = 112.5+/-1 kcal/mol and DELTAH(f)(pyrrolyl radical) = 62+/-2 kcal/mol were determined. C1 UNIV CALIF BERKELEY,DEPT CHEM,BERKELEY,CA 94720. RP BLANK, DA (reprint author), LAWRENCE BERKELEY LAB,DIV CHEM SCI,BERKELEY,CA 94720, USA. RI Lee, Yuan-Tseh/F-7914-2012; North, Simon/G-5054-2012 OI North, Simon/0000-0002-0795-796X NR 32 TC 85 Z9 85 U1 4 U2 21 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0301-0104 J9 CHEM PHYS JI Chem. Phys. PD SEP 15 PY 1994 VL 187 IS 1-2 BP 35 EP 47 DI 10.1016/0301-0104(94)00230-4 PG 13 WC Chemistry, Physical; Physics, Atomic, Molecular & Chemical SC Chemistry; Physics GA PG977 UT WOS:A1994PG97700005 ER PT J AU HEISE, JA AF HEISE, JA TI CRADA ADDENDUM SO EDN LA English DT Letter RP HEISE, JA (reprint author), SANDIA NATL LABS,ALBUQUERQUE,NM 87185, USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU CAHNERS-DENVER PUBLISHING CO PI HIGHLANDS RANCH PA 8773 S RIDGELINE BLVD, HIGHLANDS RANCH, CO 80126-2329 SN 0012-7515 J9 EDN JI EDN PD SEP 15 PY 1994 VL 39 IS 19 BP 25 EP 25 PG 1 WC Engineering, Electrical & Electronic SC Engineering GA PF961 UT WOS:A1994PF96100012 ER PT J AU HARRIS, PC THOMAS, S MACCARTHY, AB STALLINGS, RL BREUNING, MH JENNE, DE FINK, TM BUCKLE, VJ RATCLIFFE, PJ WARD, CJ AF HARRIS, PC THOMAS, S MACCARTHY, AB STALLINGS, RL BREUNING, MH JENNE, DE FINK, TM BUCKLE, VJ RATCLIFFE, PJ WARD, CJ TI A LARGE DUPLICATED AREA IN THE POLYCYSTIC KIDNEY-DISEASE-1 (PKD1) REGION OF CHROMOSOME-16 IS PRONE TO REARRANGEMENT SO GENOMICS LA English DT Article ID FAMILIAL MEDITERRANEAN FEVER; GENETIC-ANALYSIS; SHORT ARM; LOCUS; IDENTIFICATION; REPEAT; MARKER; RECOMBINATION; MUTATIONS; SEQUENCES AB An area of 500 kb at the proximal end of the polycystic kidney disease 1 (PKD1) region has been mapped in detail, with 260 kb cloned in cosmids. The area cloned from normal individuals contains two homologous but divergent regions each of 75 kb, including the previously described marker 26-6. Pulsed-held gel electrophoresis identified a duplication of 75 kb of this region, referred to as the OX duplication (OXdup), in three patients with PKD1. The OXdup probably arose by an unequal exchange promoted by misalignment of partially homologous areas. Study of the OXdup in a large PKD1 family showed that it segregated with PKD1 in just one-half of the family, indicating that a recent crossover had occurred between the OXdup and PKD1 and showing that it was not a PKD1 mutation. Further analysis identified an OXdup breakpoint fragment: the OXdup was subsequently identified in 2 normal individuals of 110 assayed. The finding of the OXdup and in other individuals an 11-kb deletion (OXdel) at a similar point within this duplicated area indicates that this is an unusually unstable genomic region. (C) 1994 Academic Press, Inc. C1 LOS ALAMOS NATL LAB,DIV LIFE SCI,LOS ALAMOS,NM 87545. LOS ALAMOS NATL LAB,CTR HUMAN GENOME STUDIES,LOS ALAMOS,NM 87545. LEIDEN UNIV,INST HUMAN GENET,2333 AL LEIDEN,NETHERLANDS. MAX PLANCK INST PSYCHIAT,DEPT NEUROIMMUNOL,D-82152 MARTINSRIED PLANE,GERMANY. DEUTSCH KREBSFORSCHUNGSZENTRUM,ORG KOMPLEXER GENOME ABT,D-69120 HEIDELBERG,GERMANY. RP HARRIS, PC (reprint author), JOHN RADCLIFFE HOSP,INST MOLEC MED,MRC,MOLEC HAEMATOL UNIT,OXFORD OX3 9DU,ENGLAND. RI Breuning, Martijn/E-3429-2010; Stallings, Raymond/A-7213-2008; OI Ratcliffe, Peter/0000-0002-2853-806X FU Wellcome Trust NR 41 TC 14 Z9 14 U1 0 U2 0 PU ACADEMIC PRESS INC JNL-COMP SUBSCRIPTIONS PI SAN DIEGO PA 525 B ST, STE 1900, SAN DIEGO, CA 92101-4495 SN 0888-7543 J9 GENOMICS JI Genomics PD SEP 15 PY 1994 VL 23 IS 2 BP 321 EP 330 DI 10.1006/geno.1994.1507 PG 10 WC Biotechnology & Applied Microbiology; Genetics & Heredity SC Biotechnology & Applied Microbiology; Genetics & Heredity GA PK060 UT WOS:A1994PK06000002 PM 7835880 ER PT J AU LAI, F STUBBS, L LEHRACH, H HUANG, YZ YEOM, Y ARTZT, K AF LAI, F STUBBS, L LEHRACH, H HUANG, YZ YEOM, Y ARTZT, K TI GENOMIC ORGANIZATION AND EXPRESSED SEQUENCES OF THE MOUSE EXTENDED H-2K REGION SO GENOMICS LA English DT Article ID MAJOR HISTOCOMPATIBILITY COMPLEX; YEAST ARTIFICIAL CHROMOSOME; GENES; MHC; PROTEIN; MUTATIONS; MARKERS; CLONES; MEMBER; MICE AB The mouse major histocompatibility complex (MHC) has long been of great interest to many biologists because of not only its critical role in the immune system, but also its association with at least three embryonic lethal genes. Here, we present an analysis of the mouse extended H-2K region using YAC technology. Six new expressed sequences were identified, demonstrating that the high gene density previously described continues. Restriction mapping of a YAC clone extending proximal of the MHC region defined a CpG-rich region located up to 320 kb away from H-2K. The absence of any CpG-rich region for a distance spanning approximately 200 kb near the YAC's proximal end suggests that the high gene density probably diminishes at a distance of 360 kb away from H-2K. The description of genomic organization of both H-2K and the extended H-2K region provides insight into the characteristics of this whole region with respect to gene diversity and density. (C) 1994 Academic Press, Inc. C1 UNIV TEXAS,DEPT ZOOL,AUSTIN,TX 78712. OAK RIDGE NATL LAB,BIOL SECT,MAMMALIAN GENET LAB,OAK RIDGE,TN 37831. IMPERIAL CANC RES FUND LAB,LONDON WC2A 3PX,ENGLAND. EUROPEAN MOLEC BIOL LAB,GENE EXPRESS,W-6900 HEIDELBERG,GERMANY. OI Stubbs, Lisa/0000-0002-9556-1972 FU NICHD NIH HHS [HD10668, HD30658] NR 33 TC 10 Z9 11 U1 0 U2 0 PU ACADEMIC PRESS INC JNL-COMP SUBSCRIPTIONS PI SAN DIEGO PA 525 B ST, STE 1900, SAN DIEGO, CA 92101-4495 SN 0888-7543 J9 GENOMICS JI Genomics PD SEP 15 PY 1994 VL 23 IS 2 BP 338 EP 343 DI 10.1006/geno.1994.1509 PG 6 WC Biotechnology & Applied Microbiology; Genetics & Heredity SC Biotechnology & Applied Microbiology; Genetics & Heredity GA PK060 UT WOS:A1994PK06000004 PM 7835882 ER PT J AU VETOULIS, G CHEN, L AF VETOULIS, G CHEN, L TI GLOBAL STRUCTURES OF ALFVEN-BALLOONING MODES IN MAGNETOSPHERIC PLASMAS SO GEOPHYSICAL RESEARCH LETTERS LA English DT Article AB We show that a steep plasma pressure gradient can lead to radially localized Alfven modes, which are damped through coupling to field line resonances. These have been called drift Alfven ballooning modes (DABM) by [Chen and Hasegawa, 1991] and are the prime candidates to explain Pc4-Pc5 geomagnetic pulsations observed during the recovery phase of geomagnetic storms. A strong dependence of the damping rate on the azimuthal wave number m is established, as well as on the equilibrium profile. A minimum azimuthal mode number can be found for the DABM to be radially trapped. We find that higher m DABMs are better localized, which is consistent with high-m observations. C1 UNIV CALIF IRVINE,DEPT PHYS,IRVINE,CA 92717. RP VETOULIS, G (reprint author), PRINCETON UNIV,PRINCETON PLASMA PHYS LAB,DIV THEORY,POB 451,PRINCETON,NJ 08543, USA. RI chen, liu/I-2297-2013 NR 7 TC 29 Z9 29 U1 0 U2 1 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 SN 0094-8276 J9 GEOPHYS RES LETT JI Geophys. Res. Lett. PD SEP 15 PY 1994 VL 21 IS 19 BP 2091 EP 2094 DI 10.1029/94GL01703 PG 4 WC Geosciences, Multidisciplinary SC Geology GA PH573 UT WOS:A1994PH57300005 ER PT J AU DICKENS, GR QUINBYHUNT, MS AF DICKENS, GR QUINBYHUNT, MS TI METHANE HYDRATE STABILITY IN SEAWATER SO GEOPHYSICAL RESEARCH LETTERS LA English DT Article ID ELECTROLYTE-SOLUTIONS; GAS; ICE AB Experimental data are presented for methane hydrate stability conditions in seawater (S almost-equal-to 33.5 part per thousand). For the pressure range of 2.75-10.0 MPa, at any given pressure, the dissociation temperature of methane hydrate is depressed by approximately -1.1 degrees-C relative to the pure methane-pure water system. These experimental results are consistent with previously reported thermodynamic predictions and experimental results obtained with artificial seawater. Collectively these results provide a minimum constraint concerning depth ranges over which methane hydrate is stable in the oceanic environment. C1 LAWRENCE BERKELEY LAB,DIV ENERGY & ENVIRONM,BERKELEY,CA 94720. RP DICKENS, GR (reprint author), UNIV MICHIGAN,DEPT GEOL SCI,ANN ARBOR,MI 48109, USA. RI Dickens, Gerald/G-1222-2011 NR 25 TC 168 Z9 189 U1 1 U2 19 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 SN 0094-8276 J9 GEOPHYS RES LETT JI Geophys. Res. Lett. PD SEP 15 PY 1994 VL 21 IS 19 BP 2115 EP 2118 DI 10.1029/94GL01858 PG 4 WC Geosciences, Multidisciplinary SC Geology GA PH573 UT WOS:A1994PH57300011 ER PT J AU MCHUGH, PR KNOLL, DA AF MCHUGH, PR KNOLL, DA TI FULLY COUPLED FINITE-VOLUME SOLUTIONS OF THE INCOMPRESSIBLE NAVIER-STOKES AND ENERGY EQUATIONS USING AN INEXACT NEWTON METHOD SO INTERNATIONAL JOURNAL FOR NUMERICAL METHODS IN FLUIDS LA English DT Article DE INCOMPRESSIBLE NAVIER-STOKES; NEWTONS METHOD; CONJUGATE GRADIENT ID NONSYMMETRIC LINEAR-SYSTEMS; MINIMAL RESIDUAL ALGORITHM; CONJUGATE-GRADIENT METHODS; ITERATIVE SOLUTION; ELEMENT SOLUTION; MATRIX; FLOWS AB An inexact Newton method is used to solve the steady, incompressible Navier-Stokes and energy equations. Finite volume differencing is employed on a staggered grid using the power law scheme of Patankar. Natural convection in an enclosed cavity is studied as the model problem. Two conjugate-gradient-like algorithms based upon the Lanczos biorthogonalization procedure are used to solve the linear systems arising on each Newton iteration, The first conjugate-gradient-like algorithm is the transpose-free quasi-minimal residual algorithm (TFQMR) and the second is the conjugate gradients squared algorithm (CGS). Incomplete lower-upper (ILU) factorization of the Jacobian matrix is used as a right preconditioner. The performance of the Newton-TFQMR algorithm is studied with regard to different choices for the TFQMR convergence criteria and the amount of fill-in allowed in the ILU factorization. Performance data are compared with results using the Newton-CGS algorithm and previous results using LINPACK banded Gaussian elimination (direct-Newton). The inexact Newton algorithms were found to be CPU competetive with the direct-Newton algorithm for the model problem considered. Among the inexact Newton algorithms, Newton-CGS outperformed Newton-TFQMR with regard to CPU time but was less robust because of the sometimes erratic CGS convergence behaviour. RP MCHUGH, PR (reprint author), EG&G IDAHO INC,IDAHO NATL ENGN LAB,COMPUTAT FLUID DYNAM UNIT,POB 1625,IDAHO FALLS,ID 83415, USA. NR 45 TC 24 Z9 25 U1 0 U2 3 PU JOHN WILEY & SONS LTD PI W SUSSEX PA BAFFINS LANE CHICHESTER, W SUSSEX, ENGLAND PO19 1UD SN 0271-2091 J9 INT J NUMER METH FL JI Int. J. Numer. Methods Fluids PD SEP 15 PY 1994 VL 19 IS 5 BP 439 EP 455 DI 10.1002/fld.1650190506 PG 17 WC Computer Science, Interdisciplinary Applications; Mathematics, Interdisciplinary Applications; Mechanics; Physics, Fluids & Plasmas SC Computer Science; Mathematics; Mechanics; Physics GA PG499 UT WOS:A1994PG49900005 ER PT J AU CERJAN, C AF CERJAN, C TI SPECTRAL CHARACTERIZATION OF A SN SOFT-X-RAY PLASMA SOURCE SO JOURNAL OF APPLIED PHYSICS LA English DT Article ID LASER-PRODUCED PLASMAS; 4D-4F EMISSION RESONANCES; RANGE AB The radiative emission from a soft x-ray laser-produced plasma source is examined in detail for the particular case of a Sn solid target under moderate illumination conditions: 10(10)-10(12) W/cm(2). The prominent spectral features which contribute to the relatively large conversion efficiency in the range 124-155 Angstrom are identified using extensive multi-configuration Dirac-Fock calculations. These data are used to generate synthetic spectra with plasma characteristics derived from a two-dimensional simulation of the ablating, radiating plasma. The comparison to the experimental results is generally favorable. RP CERJAN, C (reprint author), LAWRENCE LIVERMORE NATL LAB,POB 808,LIVERMORE,CA 94550, USA. NR 19 TC 4 Z9 4 U1 0 U2 0 PU AMER INST PHYSICS PI WOODBURY PA CIRCULATION FULFILLMENT DIV, 500 SUNNYSIDE BLVD, WOODBURY, NY 11797-2999 SN 0021-8979 J9 J APPL PHYS JI J. Appl. Phys. PD SEP 15 PY 1994 VL 76 IS 6 BP 3332 EP 3336 DI 10.1063/1.357455 PG 5 WC Physics, Applied SC Physics GA PJ117 UT WOS:A1994PJ11700015 ER PT J AU SZELES, C NIELSEN, B ASOKAKUMAR, P LYNN, KG ANDERLE, M MA, TP RUBLOFF, GW AF SZELES, C NIELSEN, B ASOKAKUMAR, P LYNN, KG ANDERLE, M MA, TP RUBLOFF, GW TI ROLE OF IMPLANTATION-INDUCED DEFECTS IN SURFACE-ORIENTED DIFFUSION OF FLUORINE IN SILICON SO JOURNAL OF APPLIED PHYSICS LA English DT Article ID ANOMALOUS DIFFUSION; IRRADIATED SILICON; POINT-DEFECTS; CHARGE-STATE; SI; ELECTRON; BORON; SEMICONDUCTORS; IMPROVEMENT; INTERFACES AB Open-volume defects introduced in Si(100) crystals during fluorine implantation were investigated by variable-energy positron beam depth profiling. The behavior of the implantation-induced lattice defects upon high temperature annealing and their role in the surface-oriented diffusion of F impurities were examined. The defects become mobile and undergo recovery at temperatures below 550 degrees C, i.e., well before the onset of fluorine diffusion as seen by secondary ion mass spectroscopy (SIMS) profiling. This behavior suggests that after irradiation and annealing the fluorine occupies substitutional sites to which positrons are insensitive. The anomalous F diffusion seen in SIMS has been explained through a two-step diffusion mechanism, in which the diffusion kinetics is determined by dissociation of the substitutional F into an interstitial F and a vacancy, followed by a rapid diffusion of the interstitial F and the vacancy through the crystal to the surface. C1 BROOKHAVEN NATL LAB, DEPT APPL SCI, UPTON, NY 11973 USA. INST RIC SCI & TECNOL, DIV SCI MAT, I-38050 TRENT, ITALY. YALE UNIV, DEPT ELECT ENGN, NEW HAVEN, CT 06520 USA. IBM CORP, THOMAS J WATSON RES CTR, YORKTOWN HTS, NY 10598 USA. RP SZELES, C (reprint author), BROOKHAVEN NATL LAB, DEPT PHYS, UPTON, NY 11973 USA. RI Nielsen, Bent/B-7353-2009; Rubloff, Gary/D-4142-2009 OI Nielsen, Bent/0000-0001-7016-0040; Rubloff, Gary/0000-0002-1901-3982 NR 52 TC 47 Z9 47 U1 1 U2 1 PU AMER INST PHYSICS PI MELVILLE PA CIRCULATION & FULFILLMENT DIV, 2 HUNTINGTON QUADRANGLE, STE 1 N O 1, MELVILLE, NY 11747-4501 USA SN 0021-8979 J9 J APPL PHYS JI J. Appl. Phys. PD SEP 15 PY 1994 VL 76 IS 6 BP 3403 EP 3409 DI 10.1063/1.357470 PG 7 WC Physics, Applied SC Physics GA PJ117 UT WOS:A1994PJ11700027 ER PT J AU STRANE, JW STEIN, HJ LEE, SR PICRAUX, ST WATANABE, JK MAYER, JW AF STRANE, JW STEIN, HJ LEE, SR PICRAUX, ST WATANABE, JK MAYER, JW TI PRECIPITATION AND RELAXATION IN STRAINED SI1-YCY/SI HETEROSTRUCTURES SO JOURNAL OF APPLIED PHYSICS LA English DT Article ID THIN SEMICONDUCTOR LAYERS; PREAMORPHIZED SI; SILICON; CARBON; IMPLANTATION; SUPERLATTICES; REDUCTION; ALLOYS AB We have studied the thermal stability of Si1-yCy/Si (y=0.007 and 0.014) heterostructures formed by solid phase epitaxial regrowth of C implanted layers. The loss of substitutional C was monitored over a temperature range of 810-925 degrees C using Fourier transform infrared absorbance spectroscopy. Concurrent strain measurements were performed using rocking curve x-ray diffraction to correlate : strain relaxation with the loss of substitutional C from the lattice. Loss of C from the lattice was initiated immediately without an incubation period, indicative of a low barrier to C clustering. The activation energy as calculated from a time to 50% completion analysis (3.3+/-5 eV) is near the activation energy for the diffusion of C in Si. Over the entire temperature range studied, annealing to complete loss of substitutional C resulted in the precipitation of C into beta-SiC. The precipitates are nearly spherical with diameters of 2-4 nm. These precipitates have the same crystallographic orientation as the Si matrix but the interfaces between the Si and beta-SiC precipitates are incoherent. During the initial stages of precipitation, however, C-rich clusters form which maintain coherency with the Si matrix so the biaxial strain in the heterostructure is partially retained. C1 SANDIA NATL LABS,ALBUQUERQUE,NM 87185. ARIZONA STATE UNIV,DEPT CHEM BIOL & MAT ENGN,TEMPE,AZ 85287. MOTOROLA INC,MESA,AZ 85202. RP STRANE, JW (reprint author), CORNELL UNIV,ITHACA,NY 14853, USA. NR 39 TC 119 Z9 120 U1 0 U2 2 PU AMER INST PHYSICS PI WOODBURY PA CIRCULATION FULFILLMENT DIV, 500 SUNNYSIDE BLVD, WOODBURY, NY 11797-2999 SN 0021-8979 J9 J APPL PHYS JI J. Appl. Phys. PD SEP 15 PY 1994 VL 76 IS 6 BP 3656 EP 3668 DI 10.1063/1.357429 PG 13 WC Physics, Applied SC Physics GA PJ117 UT WOS:A1994PJ11700062 ER PT J AU WILLIAMS, RK KROEGER, DM MARTIN, PM MAYOTTE, JR SPECHT, ED BRYNESTAD, J AF WILLIAMS, RK KROEGER, DM MARTIN, PM MAYOTTE, JR SPECHT, ED BRYNESTAD, J TI EFFECTS OF HIGH OXYGEN PRESSURES AND TEMPERATURES ON THE STABILITY OF THE 3 SUPERCONDUCTING Y-BA-CU-O COMPOUNDS SO JOURNAL OF APPLIED PHYSICS LA English DT Article ID THERMODYNAMIC STABILITY; SYSTEM; PHASE; YBA2CU3O7-X; OXIDES; YBA2CU4O8; EMF; THERMOCHEMISTRY; DECOMPOSITION; ENTHALPIES AB the course of investigating synthesis routes, stability information was developed for YBa2Cu3O7-x, Y2Ba4Cu7O15-x, and YBa2Cu4O8. The results were obtained between similar to 900 and 1040 degrees C and involve oxygen pressures between 10 and 145 atm. The observations show that the P-o2-T ranges for stability of the three phases overlap and that some stable mixtures of the phases can be synthesized. The results are compared to the results of other experimental studies and to calculations based on calorimetric data. C1 OAK RIDGE NATL LAB,DIV CHEM,OAK RIDGE,TN 37831. RP WILLIAMS, RK (reprint author), OAK RIDGE NATL LAB,DIV MET & CERAM,POB 2008,OAK RIDGE,TN 37831, USA. RI Specht, Eliot/A-5654-2009 OI Specht, Eliot/0000-0002-3191-2163 NR 32 TC 4 Z9 4 U1 0 U2 0 PU AMER INST PHYSICS PI WOODBURY PA CIRCULATION FULFILLMENT DIV, 500 SUNNYSIDE BLVD, WOODBURY, NY 11797-2999 SN 0021-8979 J9 J APPL PHYS JI J. Appl. Phys. PD SEP 15 PY 1994 VL 76 IS 6 BP 3673 EP 3678 DI 10.1063/1.357431 PG 6 WC Physics, Applied SC Physics GA PJ117 UT WOS:A1994PJ11700064 ER PT J AU JELLISON, GE MODINE, FA AF JELLISON, GE MODINE, FA TI OPTICAL FUNCTIONS OF SILICON AT ELEVATED-TEMPERATURES SO JOURNAL OF APPLIED PHYSICS LA English DT Article ID SPECTROSCOPIC ELLIPSOMETRY; DIELECTRIC FUNCTION; DEPENDENCE; ABSORPTION AB The optical functions of silicon have been measured accurately at elevated temperatures using the two-channel spectroscopic polarization modulation ellipsometer. The wavelength region covered is 240-840 nm (5.16-1.47 eV), and the temperature region covered is room temperature to 490 degrees C. Using this data, the refractive index n iind the extinction coefficient k are both parameterized as functions of temperature T and photon energy E for photon energies below the direct band edge of silicon (similar to 3.36 eV or 370 nm). In this range, n (E,T) can lie fit with five parameters, and k(E,T) can be fit with six parameters. RP JELLISON, GE (reprint author), OAK RIDGE NATL LAB,DIV SOLID STATE,POB 2008,OAK RIDGE,TN 37831, USA. NR 13 TC 115 Z9 116 U1 2 U2 23 PU AMER INST PHYSICS PI WOODBURY PA CIRCULATION FULFILLMENT DIV, 500 SUNNYSIDE BLVD, WOODBURY, NY 11797-2999 SN 0021-8979 J9 J APPL PHYS JI J. Appl. Phys. PD SEP 15 PY 1994 VL 76 IS 6 BP 3758 EP 3761 DI 10.1063/1.357378 PG 4 WC Physics, Applied SC Physics GA PJ117 UT WOS:A1994PJ11700080 ER PT J AU DESAI, SR FEIGERLE, CS MILLER, JC AF DESAI, SR FEIGERLE, CS MILLER, JC TI LASER IONIZATION MASS-SPECTROMETRY OF HOMOGENEOUS AND BINARY MOLECULAR CLUSTERS OF NITRIC-OXIDE SO JOURNAL OF CHEMICAL PHYSICS LA English DT Article ID BEAM PHOTO-IONIZATION; MULTIPHOTON IONIZATION; VANDERWAALS MOLECULES; PHOTOELECTRON-SPECTROSCOPY; METASTABLE POLYMERS; NITROGEN-OXIDES; GAS-PHASE; WATER CLUSTERS; MAGIC NUMBERS; IONS AB A potpourri of binary heteroclusters of the form (NO)(m)(Y)(n) has been investigated by coexpansion of the two components (along with argon) in a supersonic nozzle. They are subsequently ionized by picosecond, nonresonant, two-photon absorption and characterized by mass spectrometry. Neat (NO)(m)(+) clusters exhibit an odd-even intensity alternation which is attributed to electron pairing effects. A varied set of partners for the binary nitric oxide clusters includes N2O, NO2, H2O, CO2, CS2, SO2, and SF6. The observed cluster distributions are discussed in terms of cluster formation and decay mechanisms and relative bond strengths. Possible structures for some especially stable species act discussed. Of special interest are the observations of especially stable (NO)(3)(+)(Y)(n) compounds where Y represents the isovalent N2O, CO2, or CS2 partners. SF6 and its clusters also form notably stable clusters with the nitric oxide trimer ion. C1 UNIV TENNESSEE, DEPT CHEM, KNOXVILLE, TN 37996 USA. RP OAK RIDGE NATL LAB, CHEM PHYS SECT, OAK RIDGE, TN 37831 USA. NR 79 TC 23 Z9 23 U1 1 U2 17 PU AMER INST PHYSICS PI MELVILLE PA 1305 WALT WHITMAN RD, STE 300, MELVILLE, NY 11747-4501 USA SN 0021-9606 EI 1089-7690 J9 J CHEM PHYS JI J. Chem. Phys. PD SEP 15 PY 1994 VL 101 IS 6 BP 4526 EP 4535 DI 10.1063/1.467440 PG 10 WC Chemistry, Physical; Physics, Atomic, Molecular & Chemical SC Chemistry; Physics GA PF943 UT WOS:A1994PF94300006 ER PT J AU SITZ, GO FARROW, RL AF SITZ, GO FARROW, RL TI PREPARATION AND DECAY OF ALIGNMENT IN N-2 (V=1) SO JOURNAL OF CHEMICAL PHYSICS LA English DT Article ID DIRECT INELASTIC-SCATTERING; 2-PHOTON NONRESONANT EXCITATION; MULTIPHOTON IONIZATION; AG(111); STATE; ORIENTATION; POPULATION; N2 AB We report measurements of the collisional decay of the angular momentum alignment for N-2 (v=1) at 298 K. Stimulated Raman pumping of S-branch (v=1 <-- 0) transitions is used to prepare a selected rotational state of N-2 With an anisotropic spatial J distribution in the v=1 state. After allowing an appropriate time interval for collisions to occur, 2+2 resonance-enhanced multiphoton ionization is used (through the a (1) Pi(g) <-- X (1) Sigma(g)(+) transition) to detect the relative population and alignment of the pumped level and other levels to which rotational energy transfer has occurred. We have performed a series of measurements in which a selected even rotational level (J(i)=0-14) is excited and the time-dependent level population and alignment are measured at several delay times. We find the decay of alignment to be no faster than the decay of the population of the pumped level, indicating that pure m-state changing collisions are slower that J-state changing collisions. We have also observed substantial alignment of molecules which have undergone a J-state changing collision. The alignment is this case is found to be inconsistent with a Delta m=0 selection rule often used in models of rotational energy transfer rates. C1 SANDIA NATL LABS,COMBUST RES FACIL,LIVERMORE,CA 94551. RP SITZ, GO (reprint author), UNIV TEXAS,DEPT PHYS,AUSTIN,TX 78712, USA. NR 15 TC 46 Z9 46 U1 0 U2 3 PU AMER INST PHYSICS PI WOODBURY PA CIRCULATION FULFILLMENT DIV, 500 SUNNYSIDE BLVD, WOODBURY, NY 11797-2999 SN 0021-9606 J9 J CHEM PHYS JI J. Chem. Phys. PD SEP 15 PY 1994 VL 101 IS 6 BP 4682 EP 4687 DI 10.1063/1.467457 PG 6 WC Chemistry, Physical; Physics, Atomic, Molecular & Chemical SC Chemistry; Physics GA PF943 UT WOS:A1994PF94300024 ER PT J AU DAVIS, MJ KOIZUMI, H SCHATZ, GC BRADFORTH, SE NEUMARK, DM AF DAVIS, MJ KOIZUMI, H SCHATZ, GC BRADFORTH, SE NEUMARK, DM TI EXPERIMENTAL AND THEORETICAL-STUDY OF THE O+HCL TRANSITION-STATE REGION BY PHOTODETACHMENT OF OHCL- SO JOURNAL OF CHEMICAL PHYSICS LA English DT Article ID MOLECULAR-SPECTRA; HCL; DYNAMICS; ATOMS; SPECTROSCOPY; O(P-3); O(3P); CL AB We present measured and calculated photodetachment spectra of OHCl-, and we interpret the results in terms of the vibrational structure of the transition state of the O+HCl-->OH+Cl reaction. The measured spectra exhibit two distinct features-an intense broad peak at high electron kinetic energies and a less intense shoulder at lower energies. Superimposed on these broad features are several sharper structures, but they are barely discernible from noise in the spectrum. To interpret these spectra, we have used a recently developed global (3)A'' potential surface for the O+HCl reaction to calculate Franck-Condon factors, using an L(2) method (i.e., expansion in terms of square integrable basis functions) to approximate the scattering wave functions on the reactive surface. Assignment of the spectrum has been assisted using the results of quantum coupled channel calculations for the same surface. The resulting calculated spectrum shows the same broad features as the measured spectrum. There is also fine structure with spacings and energies that are similar to the experiment, but specific features do not match. To interpret both the broad and fine features in the theoretical spectrum, a hierarchical analysis is applied wherein this spectrum is decomposed by a tree construction into components of increasingly higher resolution. The physical meaning of each of these components is then determined by plotting ''smoothed states'' that are obtained from the tree coefficients. This leads to the conclusion that the two broad features in the spectrum are made up of progressions in hindered rotor states of the Cl-OH complex, with the most intense feature corresponding to OH(v=0) and the weaker shoulder corresponding to OH(v=1). There is evidence for Feshbach resonance features in the v=1 feature, but it appears that most of the fine structure is due to hindered rotor states. C1 NORTHWESTERN UNIV,DEPT CHEM,EVANSTON,IL 60201. UNIV CALIF BERKELEY,DEPT CHEM,BERKELEY,CA 94720. NORTHWESTERN UNIV,DEPT CHEM,EVANSTON,IL 60208. RP DAVIS, MJ (reprint author), ARGONNE NATL LAB,THEORET CHEM GRP,9700 S CASS AVE,ARGONNE,IL 60439, USA. RI Bradforth, Stephen/B-5186-2008; Neumark, Daniel/B-9551-2009 OI Bradforth, Stephen/0000-0002-6164-3347; Neumark, Daniel/0000-0002-3762-9473 NR 40 TC 27 Z9 27 U1 0 U2 3 PU AMER INST PHYSICS PI WOODBURY PA CIRCULATION FULFILLMENT DIV, 500 SUNNYSIDE BLVD, WOODBURY, NY 11797-2999 SN 0021-9606 J9 J CHEM PHYS JI J. Chem. Phys. PD SEP 15 PY 1994 VL 101 IS 6 BP 4708 EP 4721 DI 10.1063/1.468463 PG 14 WC Chemistry, Physical; Physics, Atomic, Molecular & Chemical SC Chemistry; Physics GA PF943 UT WOS:A1994PF94300027 ER PT J AU MANTHE, U SEIDEMAN, T MILLER, WH AF MANTHE, U SEIDEMAN, T MILLER, WH TI QUANTUM-MECHANICAL CALCULATIONS OF THE RATE-CONSTANT FOR THE H-2+OH-]H+H2O REACTION - FULL-DIMENSIONAL RESULTS AND COMPARISON TO REDUCED DIMENSIONALITY MODELS SO JOURNAL OF CHEMICAL PHYSICS LA English DT Article ID INTEGRAL CROSS-SECTIONS; DISCRETE VARIABLE REPRESENTATION; CUMULATIVE REACTION PROBABILITY; NONSYMMETRIC LINEAR-SYSTEMS; POTENTIAL-ENERGY SURFACE; TRANSITION-STATE THEORY; THERMAL RATE CONSTANTS; BIMOLECULAR REACTIONS; CONVERGED QUANTUM; RATE COEFFICIENTS AB The cumulative reaction probability is calculated for the H-2+ OH-->H+H2O reaction in its full (six) dimensionality for total angular momentum J=0. The calculation, which should give the (numerically) exact result for the assumed potential energy surface, yields the cumulative reaction probability directly, without having to solve the complete state-to-state reactive scattering problem. Higher angular momenta (J>0) were taken into account approximately to obtain the thermal rate constant k(T) over the range 300 degreestype-I transition occurs around the period n=4; (ii) this transition has a different origin with respect to the well-known case of GaAs/AlAs superlattices; (iii) the band structure of ultrathin superlattices cannot be explained in terms of a simple effective-mass theory; (iv) the wave-function localization in short-period superlattices is determined by the atomic orbital energies. RP NATL RENEWABLE ENERGY LAB, GOLDEN, CO 80401 USA. NR 23 TC 11 Z9 11 U1 0 U2 0 PU AMER PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 1098-0121 EI 1550-235X J9 PHYS REV B JI Phys. Rev. B PD SEP 15 PY 1994 VL 50 IS 11 BP 8094 EP 8097 DI 10.1103/PhysRevB.50.8094 PG 4 WC Physics, Condensed Matter SC Physics GA PJ437 UT WOS:A1994PJ43700122 ER PT J AU BLASE, X DASILVA, AJR ZHU, XJ LOUIE, SG AF BLASE, X DASILVA, AJR ZHU, XJ LOUIE, SG TI SI 2P CORE-LEVEL CHEMICAL-SHIFTS AT THE H/SI(111)-(1X1) SURFACE SO PHYSICAL REVIEW B LA English DT Note ID SI(111) AB We calculate the core-level shift of the Si 2p levels for atoms near the H/Si(111)-(1x1) surface. We show that a simple first-order perturbation theory using pseudopotentials and the local-density approximation gives good results for the photoemission spectra of the core electrons. The electric-dipole matrix elements for the levels are also calculated. The results are in good agreement with a recent high-resolution angle-resolved photoemission-spectroscopy measurement and allow us to interpret some previously unexplained experimental peaks. C1 UNIV CALIF BERKELEY,LAWRENCE BERKELEY LAB,DIV MAT SCI,BERKELEY,CA 94720. AT&T BELL LABS,MURRAY HILL,NJ 07974. RP BLASE, X (reprint author), UNIV CALIF BERKELEY,DEPT PHYS,BERKELEY,CA 94720, USA. NR 9 TC 22 Z9 22 U1 1 U2 2 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 1098-0121 J9 PHYS REV B JI Phys. Rev. B PD SEP 15 PY 1994 VL 50 IS 11 BP 8102 EP 8105 DI 10.1103/PhysRevB.50.8102 PG 4 WC Physics, Condensed Matter SC Physics GA PJ437 UT WOS:A1994PJ43700124 ER PT J AU HONG, S MAHAN, GD AF HONG, S MAHAN, GD TI CONSERVING APPROXIMATIONS - ELECTRON-GAS WITH EXCHANGE EFFECTS SO PHYSICAL REVIEW B LA English DT Article ID STATIC SCREENING FUNCTION; WAVE-NUMBER DEPENDENCE AB The conserving approximation includes a correct mix of the self-energy Sigma(p) and the vertex function Gamma(p,p + q). Only keeping the exchange self-energy Sigma(x)(p), we obtain the self-consistent equation for the vertex function Gamma(x)(p,p + q) in the closed form, which can be solved numerically. Using this vertex function, the polarization P-x(q) is obtained. We evaluate the long-wavelength limit of P-x(q) in the static case at both zero and nonzero temperatures. The latter case is compared with results obtained using the density-functional approach. C1 UNIV PENN, DEPT PHYS, PHILADELPHIA, PA 19104 USA. UNIV TENNESSEE, DEPT PHYS & ASTRON, KNOXVILLE, TN 37996 USA. RP OAK RIDGE NATL LAB, DIV SOLID STATE, POB 2008, OAK RIDGE, TN 37831 USA. NR 20 TC 15 Z9 15 U1 0 U2 0 PU AMER PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 1098-0121 EI 1550-235X J9 PHYS REV B JI Phys. Rev. B PD SEP 15 PY 1994 VL 50 IS 12 BP 8182 EP 8188 DI 10.1103/PhysRevB.50.8182 PG 7 WC Physics, Condensed Matter SC Physics GA PJ438 UT WOS:A1994PJ43800004 ER PT J AU SALES, BC JONES, EC CHAKOUMAKOS, BC FERNANDEZBACA, JA HARMON, HE SHARP, JW VOLCKMANN, EH AF SALES, BC JONES, EC CHAKOUMAKOS, BC FERNANDEZBACA, JA HARMON, HE SHARP, JW VOLCKMANN, EH TI MAGNETIC, TRANSPORT, AND STRUCTURAL-PROPERTIES OF FE1-XIRXSI SO PHYSICAL REVIEW B LA English DT Article ID FESI AB Magnetic susceptibility, resistivity, Seebeck, Hall, and powder x-ray and neutron-diffraction measurements were used to characterize single crystals of FeSi and polycrystalline samples of Fe1-xIrxSi for x < 0.2. The Rietveld refinement of low-temperature powder neutron-diffraction data on FeSi showed no change in the space group and no structural anomalies from 4 to 300 K. Magnetic and transport data from 4 to 700 K are consistent with the characterization of FeSi as a narrow-gap semiconductor (E(g) = 1200 K) with strong intrasite correlations for the states just below and above the gap. Fits to the magnetic susceptibility and resistivity data suggest that the magnetic (or direct) gap may be larger than the transport (indirect) gap. Electron mobilities in FeSi are very low (3-5 cm(2)/Vs). The thermopower of FeSi has a large positive peak (500 mu V/K) at 50 K that is attributed to an unusually strong phonon-drag mechanism. Indium acts as an electron donor in the Fe1-xIrxSi alloys. As the iridium doping level is increased, there is a rapid decrease in the low-temperature resistivity and a large negative (- 140 mu V/K) phonon-drag contribution to the thermopower. For Peltier cooling applications, a maximum value for ZT of 0.07 was found for a Fe0.95Ir0.05Si alloy at 100 K. C1 MARLOW IND,DALLAS,TX 75238. RP SALES, BC (reprint author), OAK RIDGE NATL LAB,OAK RIDGE,TN 37831, USA. RI Fernandez-Baca, Jaime/C-3984-2014; Chakoumakos, Bryan/A-5601-2016 OI Fernandez-Baca, Jaime/0000-0001-9080-5096; Chakoumakos, Bryan/0000-0002-7870-6543 NR 20 TC 100 Z9 100 U1 0 U2 14 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 0163-1829 J9 PHYS REV B JI Phys. Rev. B PD SEP 15 PY 1994 VL 50 IS 12 BP 8207 EP 8213 DI 10.1103/PhysRevB.50.8207 PG 7 WC Physics, Condensed Matter SC Physics GA PJ438 UT WOS:A1994PJ43800007 ER PT J AU TURGUT, S FALICOV, LM AF TURGUT, S FALICOV, LM TI PHENOMENOLOGICAL GINZBURG-LANDAU THEORY OF CHARGE-DENSITY-WAVE SPECTRA SO PHYSICAL REVIEW B LA English DT Article ID TRANSITION-METAL DICHALCOGENIDES; DYNAMICS; NBSE3; CONDUCTIVITY; FIELD AB A phenomenological Ginzburg-Landau theory of charge-density waves is presented. It yields, in the absence of pinning impurities, a manifold of stable (equal-energy) states that are independent of the phase of the wave. The pinning of these waves by impurities (both weak and strong pinning) is examined in detail and spectra for various impurity distributions are analyzed in detail. Strong dependence on the wave phase, change in harmonic content, and phase shifts are common features, in addition to the appearance of a continuous background. There is also a plethora of metastable states, many of which have energies close to the ground state. Comparison between the proposed theory and experiment in NbSe3 is satisfactory. C1 UNIV CALIF BERKELEY, LAWRENCE BERKELEY LAB, DIV MAT SCI, BERKELEY, CA 94720 USA. RP TURGUT, S (reprint author), UNIV CALIF BERKELEY, DEPT PHYS, BERKELEY, CA 94720 USA. RI Turgut, Sadi/A-6589-2010 OI Turgut, Sadi/0000-0003-4575-8424 NR 34 TC 3 Z9 3 U1 0 U2 1 PU AMER PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 1098-0121 EI 1550-235X J9 PHYS REV B JI Phys. Rev. B PD SEP 15 PY 1994 VL 50 IS 12 BP 8221 EP 8229 DI 10.1103/PhysRevB.50.8221 PG 9 WC Physics, Condensed Matter SC Physics GA PJ438 UT WOS:A1994PJ43800009 ER PT J AU CHEMLA, DS BIGOT, JY MYCEK, MA WEISS, S SCHAFER, W AF CHEMLA, DS BIGOT, JY MYCEK, MA WEISS, S SCHAFER, W TI ULTRAFAST PHASE DYNAMICS OF COHERENT EMISSION FROM EXCITONS IN GAAS QUANTUM-WELLS SO PHYSICAL REVIEW B LA English DT Article ID SEMICONDUCTORS; PULSES; COMPRESSION; LIGHT AB We investigate the temporal evolution of the instantaneous frequency of ultrashort-pulse four-wave mixing in GaAs/GaxAl1-xAs quantum-well structures. We find that the coherent light emitted by excitons exhibits a complex phase behavior which depends critically on the density of excitons and the central frequency of the exciting pulses. Depending on the excitation conditions, we observe nonlinear shifts of the instantaneous frequency within one ultrashort pulsed emission or quantum beats. In the latter case we determine that the beat pi-phase shift is very fast, only 40% above the fundamental quantum limit. We also present elaborate numerical simulations of the experiments based on a six-band generalization of the semiconductor Bloch equations. This formalism takes into account Coulomb many-body interactions and Pauli exclusion. It reproduces the salient features of the experimental data. It fails to account for important details revealed by the very sensitive phase measurements. The discrepancies can be traced back to two approximations in the theory: the statical treatment of screening, and the Lorentzian description of dephasing. In both cases, this indicates the need for theoretical refinements requiring a microscopic description of Coulomb scattering and dephasing processes in a non-Markovian theory. C1 UNIV CALIF BERKELEY,LAWRENCE BERKELEY LAB,DIV MAT SCI,BERKELEY,CA 94720. KFA JULICH,HOCHSTLEISTUNGSRECHEN ZENTRUM,D-52428 JULICH,GERMANY. INST PHYS & CHIM MAT STRASBOURG,F-67084 STRASBOURG,FRANCE. RP CHEMLA, DS (reprint author), UNIV CALIF BERKELEY,DEPT PHYS,BERKELEY,CA 94720, USA. RI weiss, shimon/B-4164-2009 OI weiss, shimon/0000-0002-0720-5426 NR 29 TC 74 Z9 74 U1 0 U2 5 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 0163-1829 J9 PHYS REV B JI Phys. Rev. B PD SEP 15 PY 1994 VL 50 IS 12 BP 8439 EP 8453 DI 10.1103/PhysRevB.50.8439 PG 15 WC Physics, Condensed Matter SC Physics GA PJ438 UT WOS:A1994PJ43800032 ER PT J AU NAZARENO, HN GALLARDO, JC AF NAZARENO, HN GALLARDO, JC TI DETERMINATION OF THE COMPTON WAVELENGTH ON A SUPERLATTICE SO PHYSICAL REVIEW B LA English DT Note ID BLOCH OSCILLATIONS; SEMICONDUCTOR SUPERLATTICES; DYNAMIC LOCALIZATION; ELECTRIC-FIELD; TRANSPORT AB We suggest a method to measure the Compton wavelength by placing a superlattice in combined static electric and magnetic fields applied along its growth axis. When the magnitudes of the fields are appropriately chosen, a resonance can be excited between the transverse (circular) and longitudinal (oscillatory) motion of the carriers in the superlattice. This resonance enables an accurate measurement of the Compton wavelength. C1 BROOKHAVEN NATL LAB,UPTON,NY 11973. RP NAZARENO, HN (reprint author), UNIV BRASILIA,INT CTR CONDENSED MATTER PHYS,CAIXA POSTAL 04667,BR-70910 BRASILIA,DF,BRAZIL. NR 17 TC 2 Z9 2 U1 0 U2 0 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 0163-1829 J9 PHYS REV B JI Phys. Rev. B PD SEP 15 PY 1994 VL 50 IS 12 BP 8872 EP 8874 DI 10.1103/PhysRevB.50.8872 PG 3 WC Physics, Condensed Matter SC Physics GA PJ438 UT WOS:A1994PJ43800084 ER PT J AU MCCARTY, KF MILLS, MJ MEDLIN, DL FRIEDMANN, TA AF MCCARTY, KF MILLS, MJ MEDLIN, DL FRIEDMANN, TA TI GROWTH AND CHARACTERIZATION OF EPITAXIAL CUBIC BORON-NITRIDE FILMS ON SILICON - COMMENT SO PHYSICAL REVIEW B LA English DT Note ID PULSED-LASER DEPOSITION AB We review the x-ray-diffraction and high-resolution transmission electron microscopy (HRTEM) data that Doll et al. [Phys. Rev. B 43, 6816 (1991)] used as evidence for the epitaxial growth of cubic boron nitride (cBN) on silicon (001) surfaces. The three reported x-ray-diffraction peaks do not provide unambiguous evidence for cBN due to potential interference from the graphitelike phase of BN and from artifacts of the silicon substrate. We provide an interpretation of their HRTEM image. Our interpretation does not provide support for an epitaxial cBN/Si relationship or the presence of cBN. RP MCCARTY, KF (reprint author), SANDIA NATL LABS, LIVERMORE, CA 94551 USA. RI McCarty, Kevin/F-9368-2012 OI McCarty, Kevin/0000-0002-8601-079X NR 21 TC 3 Z9 3 U1 0 U2 2 PU AMER PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 1098-0121 J9 PHYS REV B JI Phys. Rev. B PD SEP 15 PY 1994 VL 50 IS 12 BP 8907 EP 8910 DI 10.1103/PhysRevB.50.8907 PG 4 WC Physics, Condensed Matter SC Physics GA PJ438 UT WOS:A1994PJ43800094 ER PT J AU JOHNSON, PD GARRISON, K DONG, Q SMITH, NV LI, DQ MATTSON, J PEARSON, J BADER, SD AF JOHNSON, PD GARRISON, K DONG, Q SMITH, NV LI, DQ MATTSON, J PEARSON, J BADER, SD TI HYBRIDIZATION AND THE EFFECTIVE-MASS OF QUANTUM-WELL STATES IN MAGNETIC MULTILAYERS SO PHYSICAL REVIEW B LA English DT Note ID EXCHANGE; SUPERLATTICES; SUBSTRATE; FILMS AB Angle-resolved-photoemission studies of the dispersion of the quantum-well states in copper thin films deposited on a Co(001) substrate reveal that hybridization in the interface leads to a large increase in the effective mass of the electrons. These observations have implications for theories of the oscillatory exchange coupling in the related magnetic multilayers, particularly where Fermi-surface spanning vectors away from the center of the zone are invoked as in the case of the short-period oscillation in the Co/Cu(001) multilayers. C1 UNIV CALIF BERKELEY,LAWRENCE BERKELEY LAB,BERKELEY,CA 94720. ARGONNE NATL LAB,DIV MAT SCI,ARGONNE,IL 60439. RP JOHNSON, PD (reprint author), BROOKHAVEN NATL LAB,DEPT PHYS,UPTON,NY 11973, USA. RI Bader, Samuel/A-2995-2013 NR 18 TC 37 Z9 37 U1 0 U2 2 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 0163-1829 J9 PHYS REV B JI Phys. Rev. B PD SEP 15 PY 1994 VL 50 IS 12 BP 8954 EP 8956 DI 10.1103/PhysRevB.50.8954 PG 3 WC Physics, Condensed Matter SC Physics GA PJ438 UT WOS:A1994PJ43800106 ER PT J AU BORDE, A AF BORDE, A TI OPEN AND CLOSED UNIVERSES, INITIAL SINGULARITIES, AND INFLATION SO PHYSICAL REVIEW D LA English DT Article ID WEAK ENERGY CONDITION; GENERAL RELATIVITY; SPACETIME; MATTER; FIELDS AB The existence of initial singularities in expanding universes is proved without assuming the timelike convergence condition. The assumptions made in the proof are ones likely to hold both in open universes and in many closed ones. (It is further argued that at least some of the expanding closed universes that do not obey a key assumption of the theorem will have initial singularities on other grounds.) The result is significant for two reasons: (a) previous closed-universe singularity theorems have assumed the timelike convergence condition, and (b) the timelike convergence condition is known to be violated in inflationary spacetimes. An immediate consequence of this theorem is that a recent result on initial singularities in open, future-eternal, inflating spacetimes may now be extended to include many closed universes. Also, as a fringe benefit, the time reverse of the theorem may be applied to gravitational collapse. C1 BROOKHAVEN NATL LAB,HIGH ENERGY THEORY GRP,UPTON,NY 11973. LONG ISL UNIV,SOUTHAMPTON,NY 11968. RP BORDE, A (reprint author), TUFTS UNIV,DEPT PHYS & ASTRON,INST COSMOL,MEDFORD,MA 02155, USA. NR 45 TC 56 Z9 56 U1 0 U2 1 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 0556-2821 J9 PHYS REV D JI Phys. Rev. D PD SEP 15 PY 1994 VL 50 IS 6 BP 3692 EP 3702 DI 10.1103/PhysRevD.50.3692 PG 11 WC Astronomy & Astrophysics; Physics, Particles & Fields SC Astronomy & Astrophysics; Physics GA PJ037 UT WOS:A1994PJ03700013 ER PT J AU GLENDENNING, NK WEBER, F AF GLENDENNING, NK WEBER, F TI IMPACT OF FRAME DRAGGING ON THE KEPLER FREQUENCY OF RELATIVISTIC STARS SO PHYSICAL REVIEW D LA English DT Article ID CENTRIFUGAL-FORCE; PULSAR; MODELS AB It has long been known that in general relativity the centrifugal force on an element in a rotating star involves the frequency of the star relative to the frequency at which the local inertial frame is dragged by the rotation. Intuitively, one would expect that this would increase the critical frequency at which rotation disrupts the star. Our analysis shows the opposite to be true and gives theoretical underpinning to a commonly used empirical formula for the Kepler frequency of a rotating star. C1 UNIV MUNICH,INST THEORET PHYS,D-80333 MUNICH,GERMANY. RP GLENDENNING, NK (reprint author), UNIV CALIF BERKELEY,LAWRENCE BERKELEY LAB,DIV NUCL SCI,1 CYCLOTRON RD,BERKELEY,CA 94720, USA. NR 20 TC 21 Z9 21 U1 0 U2 0 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 0556-2821 J9 PHYS REV D JI Phys. Rev. D PD SEP 15 PY 1994 VL 50 IS 6 BP 3836 EP 3841 DI 10.1103/PhysRevD.50.3836 PG 6 WC Astronomy & Astrophysics; Physics, Particles & Fields SC Astronomy & Astrophysics; Physics GA PJ037 UT WOS:A1994PJ03700025 ER PT J AU FARHI, E KHOZE, VV RAJAGOPAL, K SINGLETON, R AF FARHI, E KHOZE, VV RAJAGOPAL, K SINGLETON, R TI SPHERICAL-SHELLS OF CLASSICAL GAUGE FIELD AND THEIR TOPOLOGICAL CHARGE AS A PERTURBATIVE EXPANSION SO PHYSICAL REVIEW D LA English DT Article ID WEINBERG-SALAM THEORY; HIGH-ENERGY; BARYON-NUMBER; VIOLATION; VACUUM AB We consider the classical equations of motion of SU(2) gauge theory, without a Higgs field, in Minkowski space. We work in the spherical ansatz and develop a perturbative expansion in the coupling constant g for solutions which in the far past look like freely propagating spherical shells. The topological charge Q of these solutions is typically noninteger. We then show that Q can be expressed as a power series expansion in g which can be nonzero at finite order, We give an explicit analytic calculation of the order g(5) contribution to Q for specific initial pulses. We discuss the relation between our findings and anomalous fermion number violation, and speculate on the physical implications of our results. C1 MIT,DEPT PHYS,CAMBRIDGE,MA 02139. STANFORD LINEAR ACCELERATOR CTR,STANFORD,CA 94309. HARVARD UNIV,LYMAN LAB PHYS,CAMBRIDGE,MA 02138. BOSTON UNIV,DEPT PHYS,BOSTON,MA 02215. RP FARHI, E (reprint author), MIT,CTR THEORET PHYS,NUCL SCI LAB,CAMBRIDGE,MA 02139, USA. NR 17 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 0556-2821 J9 PHYS REV D JI Phys. Rev. D PD SEP 15 PY 1994 VL 50 IS 6 BP 4162 EP 4174 DI 10.1103/PhysRevD.50.4162 PG 13 WC Astronomy & Astrophysics; Physics, Particles & Fields SC Astronomy & Astrophysics; Physics GA PJ037 UT WOS:A1994PJ03700055 ER PT J AU WAN, XJ ZHU, JH JING, KL LIU, CT AF WAN, XJ ZHU, JH JING, KL LIU, CT TI HYDROGEN DIFFUSIVITY IN BORON-DOPED POLYCRYSTALLINE NI3AL SO SCRIPTA METALLURGICA ET MATERIALIA LA English DT Article ID ENVIRONMENTAL EMBRITTLEMENT; DUCTILITY C1 OAK RIDGE NATL LAB,DIV MET & CERAM,OAK RIDGE,TN 37831. RP WAN, XJ (reprint author), SHANGHAI UNIV SCI & TECHNOL,SHANGHAI 200072,PEOPLES R CHINA. OI Liu, Chain Tsuan/0000-0001-7888-9725 NR 18 TC 36 Z9 44 U1 0 U2 5 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD, ENGLAND OX5 1GB SN 0956-716X J9 SCRIPTA METALL MATER JI Scr. Metall. Materialia PD SEP 15 PY 1994 VL 31 IS 6 BP 677 EP 681 DI 10.1016/0956-716X(94)90209-7 PG 5 WC Materials Science, Multidisciplinary; Metallurgy & Metallurgical Engineering SC Materials Science; Metallurgy & Metallurgical Engineering GA NW207 UT WOS:A1994NW20700006 ER PT J AU CLOSE, MR MCCARLEY, RE AF CLOSE, MR MCCARLEY, RE TI SYNTHESIS AND STRUCTURE OF WNCL3 AND EVIDENCE FOR STRUCTURAL MODIFICATIONS WITH BOUND CHLOROCARBON SOLVENTS SO INORGANIC CHEMISTRY LA English DT Article ID CRYSTAL-STRUCTURE; NITRIDO COMPLEXES; TUNGSTEN AB A convenient synthesis of WNCl3 resulted from the reaction between WCl6 and Me(3)SiN(3) in 1:1 molar ratio in refluxing 1,2-dichloroethane (DCE) at 84 degrees C, The isolated material was shown by elemental analysis, IR, and NMR to be WNCl3.1.1DCE. Heating in vacuo at 160 degrees C was required to remove the DCE and give unsolvated [WNCl3](4). Crystals of the latter were grown by sublimation in a sealed tube under a temperature gradient of 290/300 degrees C. WNCl3 is isostructural with MoNCl3; triclinic P1 $($) over bar$$, a = 7.752(2) Angstrom, b = 8.143(2) Angstrom, c = 9.114(2) Angstrom, alpha = 98.71(3)degrees, beta = 107.52(3)degrees, gamma = 110.40(3)degrees, Z = 4, R = 0.0431, R(W), = 0.0554. The structure is composed of [WNl(3)](4) molecules interconnected through W-Cl-W bridge bonding. The tetramers consist of planar W4N4 rings with alternating short and long W-N bonds, with average distances of 1.696(7) and 2.082(7) Angstrom, respectively, similar to several complexes [WNCl3.L](4) known previously. C1 IOWA STATE UNIV SCI & TECHNOL,US DOE,AMES LAB,AMES,IA 50011. IOWA STATE UNIV SCI & TECHNOL,DEPT CHEM,AMES,IA 50011. NR 16 TC 17 Z9 17 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 SEP 14 PY 1994 VL 33 IS 19 BP 4198 EP 4201 DI 10.1021/ic00097a002 PG 4 WC Chemistry, Inorganic & Nuclear SC Chemistry GA PG754 UT WOS:A1994PG75400002 ER PT J AU SHADLE, SE HEDMAN, B HODGSON, KO SOLOMON, EI AF SHADLE, SE HEDMAN, B HODGSON, KO SOLOMON, EI TI LIGAND K-EDGE X-RAY-ABSORPTION SPECTROSCOPY AS A PROBE OF LIGAND-METAL BONDING - CHARGE DONATION AND COVALENCY IN COPPER-CHLORIDE SYSTEMS SO INORGANIC CHEMISTRY LA English DT Article ID IRON MOLYBDENUM COFACTOR; MOLECULAR-STRUCTURE; ELECTRONIC-STRUCTURE; CRYSTAL; COMPLEXES; STATE; NITROGENASE; PHOTOELECTRON; DERIVATIVES; INSIGHTS AB X-ray absorption spectra (XAS) have been measured at the chloride K-edge for a series of complexes containing chloride ligands bound to open shell d(9) copper ions in order to probe ligand-metal bonding. The intensity of the pre-edge feature in these spectra reflects the covalency in the half-occupied d(x2-y2)-derived molecular orbital (HOMO) of the complex. The energy of the pre-edge feature is related to both the charge on the ligand and the HOMO energy. An analysis of the intensity and energy of the pre-edge feature as well as the energy of the rising absorption edge provides quantitative information about the covalency of the ligand-metal interaction, the charge donated by the chloride, and the energy of the copper d-manifold. The results demonstrate that ligand K-edge XAS features can be used to obtain information about ligand-metal bonding. The results also identify the chemical basis for trends in the XAS data for the following complexes: D4hCuCl42-, D-2d CuCl42-, planar trans-CuCl2- (pdmp)(2) (pdmp = N-phenyl-3,5-dimethylpyrazole), square pyramidal CuCl53-, the planar dimer KCuCl3, the distorted tetrahedral dimer (Ph(4)P)CuCl3, and two dimers with mixed ligation, one containing a bridging chloride, and the other, containing terminally bound chloride. Several of these results are supported by independent spectral data or by basic ligand field concepts. A geometric distortion from square planar to distorted tetrahedral results in a decrease in the chloride-copper HOMO covalency but an increase in the total charge donation by the chlorides. While the geometry can maximize the overlap for a highly covalent HOMO, this does not necessarily reflect the overall charge donation. The CI-Cu(II) bonding interactions are dependent on the nature of the other coordinating ligands. Replacement of chlorides by less strongly donating ligands causes an increase in charge donation by the remaining chloride ligands. An increase in the coordination number of the copper or in the charge donation by the ligands (resulting in a lower effective nuclear charge on the copper) causes an increase in the copper d-manifold energy. Finally, the bonding of a terminal vs bridging chloride is very different, in that for the latter there is more total charge donation and a higher ligand covalent contribution to the HOMO of the two coppers. C1 STANFORD UNIV,STANFORD SYNCHROTRON RADIAT LAB,STANFORD,CA 94305. STANFORD UNIV,DEPT CHEM,STANFORD,CA 94305. NR 37 TC 92 Z9 92 U1 0 U2 22 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 SN 0020-1669 J9 INORG CHEM JI Inorg. Chem. PD SEP 14 PY 1994 VL 33 IS 19 BP 4235 EP 4244 DI 10.1021/ic00097a009 PG 10 WC Chemistry, Inorganic & Nuclear SC Chemistry GA PG754 UT WOS:A1994PG75400009 ER PT J AU AVENS, LR BARNHART, DM BURNS, CJ MCKEE, SD SMITH, WH AF AVENS, LR BARNHART, DM BURNS, CJ MCKEE, SD SMITH, WH TI OXIDATION CHEMISTRY OF A URANIUM(III) ARYLOXIDE SO INORGANIC CHEMISTRY LA English DT Article ID ACTINIDE ALKOXIDE CHEMISTRY; CRYSTAL-STRUCTURE; COMPLEXES; ADDUCTS; LIGANDS; (C5ME5)2UCL.THF; TETRAHYDROFURAN; COORDINATION; METALLOCENES; DERIVATIVES AB The oxidation chemistry of the uranium(III) aryloxide complex U(OAr)(3) (OAr = 2,6-di-tert-butylphenoxide) has been explored with a variety of one-electron oxidants. Oxidation of U(OAr)(3) with either AgBF4 or AgPF6 produces the uranium(IV) fluoride FU(OAr)(3), 1. The analogous chloride compound, CIU(OAr)(3), 2, is prepared by reaction with either benzyl chloride or PCl5. Oxidation by AgBr, CBr4, or PBr5 yields BrU(OAr)(3), 3. Oxidation of U(OAr)(3) by elemental iodine yields IU(OAr)(3), 4. Compound 4 crystallizes in the space group P2(1)/n, with unit cell dimensions a = 20.005(6) Angstrom, b = 10.228(4) Angstrom, c = 21.879(6) Angstrom, beta = 115.30(2)degrees, V = 4047(2) Angstrom(3), and Z = 4. Oxidation of U(OAr)(3) with CL (carbon tetraiodide) does not yield 4 but rather gives rise to I2U(OAr)(2), 5. Orthorhombic crystals of the THF adduct I2U(OAr)(2)(THF) were obtained from THF/hexane. I2U(OAr)(2)(THF) crystallizes in the space grpup Pbca, with unit cell dimensions a = 18.197(2) Angstrom, b = 17.866(2) Angstrom, c = 20.930(3) Angstrom, V = 6804.5(14) Angstrom(3), and Z = 8. The chalcogenide-bridged compounds (ArO)(3)U-O-U(OAr)(3), 6, and (ArO)(3)U-S-U(OAr)(3), 7, can be prepared by reaction with a variety of chalcogen-donor reagents; reaction of the tris(aryloxido)uranium complex with N2O, NO, Me(3)NO, or pyNO yields compound 6, while reaction with either COS or Ph(3)P=S affords 7. Compound 7 crystallizes as a diethyl ether solvate in the space group P1 $($) over bar$$, with unit cell dimensions a = 13.290(3) Angstrom, b = 13.744(4) Angstrom, c = 14.643(5) Angstrom, alpha = 81.41(2)degrees, beta = 65.36(2)degrees, gamma = 67.58(2)degrees, V = 2247.4(11) Angstrom(3), and Z = 1. Oxidation of U(OAr)(3) by molecular oxygen does not result in the isolation of the oxo-bridged dinuclear species but in the formation of the known uranium(IV) compound U(OAr)(4) by ligand redistribution. C1 LOS ALAMOS NATL LAB,LOS ALAMOS,NM 87545. NR 54 TC 67 Z9 67 U1 2 U2 7 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 SN 0020-1669 J9 INORG CHEM JI Inorg. Chem. PD SEP 14 PY 1994 VL 33 IS 19 BP 4245 EP 4254 DI 10.1021/ic00097a010 PG 10 WC Chemistry, Inorganic & Nuclear SC Chemistry GA PG754 UT WOS:A1994PG75400010 ER PT J AU MARTIN, NLS THOMPSON, DB BAUMAN, RP WILSON, M JIMENEZMIER, J CALDWELL, CD KRAUSE, MO AF MARTIN, NLS THOMPSON, DB BAUMAN, RP WILSON, M JIMENEZMIER, J CALDWELL, CD KRAUSE, MO TI PHOTOELECTRON-SPECTRA IN CADMIUM - COMPARISON WITH THEORY AND (E, 2E) SPECTRA SO JOURNAL OF PHYSICS B-ATOMIC MOLECULAR AND OPTICAL PHYSICS LA English DT Article ID COHERENT EXCITATION; AUTOIONIZING LEVELS; SPECTROSCOPY; RESONANCES AB Experimental photoelectron data in Cd for the 4d95s25p autoionizing region are compared with calculations and high resolution (e, 2e) spectroscopic data. Doubly excited autoionizing states are found to influence the spectral profile and are observed in both photoelectron and (e, 2e) spectra. C1 NATL AUTONOMOUS UNIV MEXICO,INST CIENCIAS NUCL,MEXICO CITY 04510,DF,MEXICO. OAK RIDGE NATL LAB,OAK RIDGE,TN 37831. UNIV CENT FLORIDA,ORLANDO,FL 32816. UNIV LONDON,DEPT PHYS,SURREY TW20 0EX,ENGLAND. RP MARTIN, NLS (reprint author), UNIV KENTUCKY,DEPT PHYS & ASTRON,LEXINGTON,KY 40506, USA. RI Jimenez-Mier, Jose/A-5081-2009 OI Jimenez-Mier, Jose/0000-0002-5939-9568 NR 12 TC 5 Z9 5 U1 0 U2 0 PU IOP PUBLISHING LTD PI BRISTOL PA TECHNO HOUSE, REDCLIFFE WAY, BRISTOL, ENGLAND BS1 6NX SN 0953-4075 J9 J PHYS B-AT MOL OPT JI J. Phys. B-At. Mol. Opt. Phys. PD SEP 14 PY 1994 VL 27 IS 17 BP 3945 EP 3951 DI 10.1088/0953-4075/27/17/018 PG 7 WC Optics; Physics, Atomic, Molecular & Chemical SC Optics; Physics GA PJ483 UT WOS:A1994PJ48300018 ER PT J AU WIEDERRECHT, GP SEIBERT, M GOVINDJEE WASIELEWSKI, MR AF WIEDERRECHT, GP SEIBERT, M GOVINDJEE WASIELEWSKI, MR TI FEMTOSECOND PHOTODICHROISM STUDIES OF ISOLATED PHOTOSYSTEM-II REACTION CENTERS SO PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF THE UNITED STATES OF AMERICA LA English DT Article DE PHOTOSYNTHESIS; GREEN PLANTS; FEMTOSECOND SPECTROSCOPY ID REACTION-CENTER COMPLEX; PRIMARY CHARGE SEPARATION; PICOSECOND FLUORESCENCE KINETICS; PHOTOSYNTHETIC REACTION CENTERS; EXCITED-STATE STRUCTURE; 2 REACTION CENTERS; RHODOPSEUDOMONAS-SPHAEROIDES; PLANT PHOTOSYNTHESIS; ELECTRON-TRANSFER; ENERGY-TRANSFER AB Photosynthetic conversion of light energy into chemical potential begins in reaction center protein complexes, where rapid charge separation occurs with nearly unit quantum efficiency. Primary charge separation was studied in isolated photosystem II reaction centers from spinach containing 6 chlorophyll a, 2 pheophytin a (Pheo), 1 cytochrome b(559), and 2 beta carotene molecules. Time-resolved pump-probe kinetic spectroscopy was carried out with 105-fs time resolution and with the pump laser polarized parallel, perpendicular, and at the magic angle (54.7 degrees) relative to the polarized probe beam. The time evolution of the transient absorption changes due to the formation of the oxidized primary electron donor P680(+) and the reduced primary electron acceptor Pheo(-) were measured at 820 nm and 545 nm, respectively. In addition, kinetics were obtained at 680 nm, the wavelength ascribed to the Q(y) transition of the primary electron donor P680 in the reaction center. At each measured probe wavelength the kinetics of the transient absorption changes can be fit to two major kinetic components. The relative amplitudes of these components are strongly dependent on the polarization of the pump beam relative to that of the probe. At the magic angle, where no photoselection occurs, the amplitude of the 3-ps component, which is indicative of the charge separation, dominates. When the primary electron acceptor Pheo is reduced prior to P680 excitation, the 3-ps component is eliminated. C1 ARGONNE NATL LAB,DIV CHEM,ARGONNE,IL 60439. NATL RENEWABLE ENERGY LAB,PHOTOCONVERS BRANCH,GOLDEN,CO 80401. UNIV ILLINOIS,DEPT PLANT BIOL,URBANA,IL 61801. NR 48 TC 39 Z9 39 U1 0 U2 4 PU NATL ACAD SCIENCES PI WASHINGTON PA 2101 CONSTITUTION AVE NW, WASHINGTON, DC 20418 SN 0027-8424 J9 P NATL ACAD SCI USA JI Proc. Natl. Acad. Sci. U. S. A. PD SEP 13 PY 1994 VL 91 IS 19 BP 8999 EP 9003 DI 10.1073/pnas.91.19.8999 PG 5 WC Multidisciplinary Sciences SC Science & Technology - Other Topics GA PG521 UT WOS:A1994PG52100055 PM 8090759 ER PT J AU LU, B ZHOU, P CHENG, JL MALLOY, KJ ZOLPER, JC AF LU, B ZHOU, P CHENG, JL MALLOY, KJ ZOLPER, JC TI HIGH-TEMPERATURE PULSED AND CONTINUOUS-WAVE OPERATION AND THERMALLY STABLE THRESHOLD CHARACTERISTICS OF VERTICAL-CAVITY SURFACE-EMITTING LASERS GROWN BY METALORGANIC CHEMICAL-VAPOR-DEPOSITION SO APPLIED PHYSICS LETTERS LA English DT Article AB A systematic and comparative study of the temperature performance of vertical-cavity surface-emitting lasers (VCSELs) is presented to discuss how thermal effects govern their temperature range for cw operation. These include the temperature-induced detuning of the lasing mode from the gain peak, thermal self-heating, and thermal runaway. The power dissipation of the VCSELs and the resultant rise in junction temperature have been measured as a function of the mode detuning. It is shown that low power dissipation is achieved by aligning the cavity mode to the gain peak and introducing continuously graded heterointerfaces throughout the VCSEL structure. By selecting the optimal mode detuning, VCSELs have achieved excellent operating characteristics over a broad range of temperatures, including thermally stable threshold voltage and current, and a very wide temperature range for both pulsed (100-580 K) and continuous-wave (100-400 K) operations. C1 SANDIA NATL LABS,ALBUQUERQUE,NM 87185. RP LU, B (reprint author), UNIV NEW MEXICO,CTR HIGH TECHNOL MAT,EECE BLDG,ROOM 125,ALBUQUERQUE,NM 87131, USA. RI Malloy, Kevin/E-5994-2010 NR 4 TC 46 Z9 47 U1 0 U2 2 PU AMER INST PHYSICS PI WOODBURY PA CIRCULATION FULFILLMENT DIV, 500 SUNNYSIDE BLVD, WOODBURY, NY 11797-2999 SN 0003-6951 J9 APPL PHYS LETT JI Appl. Phys. Lett. PD SEP 12 PY 1994 VL 65 IS 11 BP 1337 EP 1339 DI 10.1063/1.112044 PG 3 WC Physics, Applied SC Physics GA PG223 UT WOS:A1994PG22300003 ER PT J AU RONG, ZY ABRAIZOV, M DORFMAN, B STRONGIN, M YANG, XQ YAN, D POLLAK, FH AF RONG, ZY ABRAIZOV, M DORFMAN, B STRONGIN, M YANG, XQ YAN, D POLLAK, FH TI SCANNING-TUNNELING-MICROSCOPY OF DIAMOND-LIKE NANOCOMPOSITE FILMS SO APPLIED PHYSICS LETTERS LA English DT Article ID CARBON-FILMS; SURFACE AB Scanning tunneling microscopy is used in the present investigation to study metal containing diamond-like nanocomposites, viz. (a-C:H)/(a-Si:O)/Me films. By comparing images taken before and after samples were annealed at 450-degrees-C for two hours, a formation of sp2-rich regions is found in Pt containing samples, in contrast to the high thermal stability shown for transition-metal containing samples. It indicates that the Pt engenders the ''loosening'' of the diamond-like matrix with a decrease in the energy barrier. These results are further confirmed by Fourier transformation infrared spectroscopy and Raman spectroscopy. The obtained micro- and nanoscale surface images and observed transformation from sp3 to sp2 bonding provides new understanding of the fundamental structure of diamond-like films. C1 KPOLYTECH UNIV,INST INST MAT & TECHNOL,FARMINGDALE,NY 11735. BROOKHAVEN NATL LAB,DEPT PHYS,UPTON,NY 11973. CUNY BROOKLYN COLL,DEPT PHYS,BROOKLYN,NY 11210. RP RONG, ZY (reprint author), SUNY STONY BROOK,DEPT PHYS,STONY BROOK,NY 11794, USA. NR 11 TC 15 Z9 15 U1 0 U2 1 PU AMER INST PHYSICS PI WOODBURY PA CIRCULATION FULFILLMENT DIV, 500 SUNNYSIDE BLVD, WOODBURY, NY 11797-2999 SN 0003-6951 J9 APPL PHYS LETT JI Appl. Phys. Lett. PD SEP 12 PY 1994 VL 65 IS 11 BP 1379 EP 1381 DI 10.1063/1.112058 PG 3 WC Physics, Applied SC Physics GA PG223 UT WOS:A1994PG22300017 ER PT J AU GOODWIN, A NOVAK, BM AF GOODWIN, A NOVAK, BM TI SYNTHESIS OF NEW RIGID-ROD HELICAL POLYMERS THROUGH THE LIVING POLYMERIZATION OF CARBODIIMIDES USING TITANIUM(IV) COMPLEXES SO MACROMOLECULES LA English DT Note ID OPTICALLY-ACTIVE POLYISOCYANATES; MACROMOLECULAR STEREOCHEMISTRY; CRYSTAL-STRUCTURES; ISOCYANIDES; ISOCYANATES; CHIRALITY; CATALYSTS; CHAINS C1 UNIV CALIF BERKELEY,DEPT CHEM,BERKELEY,CA 94720. LAWRENCE BERKELEY LAB,DIV MAT SCI,BERKELEY,CA 94720. UNIV MASSACHUSETTS,DEPT POLYMER SCI & ENGN,AMHERST,MA 01003. NR 44 TC 73 Z9 73 U1 0 U2 4 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 SN 0024-9297 J9 MACROMOLECULES JI Macromolecules PD SEP 12 PY 1994 VL 27 IS 19 BP 5520 EP 5522 DI 10.1021/ma00097a037 PG 3 WC Polymer Science SC Polymer Science GA PG449 UT WOS:A1994PG44900037 ER PT J AU MCABEE, TL WILSON, JR AF MCABEE, TL WILSON, JR TI MEAN-FIELD PION CALCULATIONS OF HEAVY-ION COLLISIONS AT BEVALAC ENERGIES SO NUCLEAR PHYSICS A LA English DT Article DE LA-139 (LA-139, CHI-PI), E=530-1350 MEV/NUCLEON; CALCULATED PION SPECTRA, MULTIPLICITY; HYDRODYNAMIC APPROXIMATION, TIME-DEPENDENT BOLTZMANN EQUATION, PIONS IN A MEAN-FIELD MODEL ID NUCLEAR-MATTER; EQUATION; STATE AB A model for relativistic heavy-ion collisions is developed and applied to the La-139 + La-139 system for several collision energies as measured at the Bevalac. Nuclei are treated within a hydrodynamic approximation and a time-dependent Boltzmann equation is used to describe pions in a mean-field model. Good agreement in both pion multiplicity and spectrum is attained. These results place limits on the magnitude of the Landau-Migdal parameter g'. RP MCABEE, TL (reprint author), LAWRENCE LIVERMORE NATL LAB,LIVERMORE,CA 94550, USA. NR 24 TC 9 Z9 9 U1 0 U2 0 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0375-9474 J9 NUCL PHYS A JI Nucl. Phys. A PD SEP 12 PY 1994 VL 576 IS 4 BP 626 EP 638 DI 10.1016/0375-9474(94)90747-1 PG 13 WC Physics, Nuclear SC Physics GA PG101 UT WOS:A1994PG10100006 ER PT J AU TERAKOPIAN, GM HAMILTON, JH OGANESSIAN, YT KORMICKI, J POPEKO, GS DANIEL, AV RAMAYYA, AV LU, Q BUTLERMOORE, K MA, WC DENG, JK SHI, D KLIMAN, J POLHORSKY, V MORHAC, M GREINER, W SANDELESCU, A COLE, JD ARYAEINEJAD, R JOHNSON, NR LEE, IY MCGOWAN, FK AF TERAKOPIAN, GM HAMILTON, JH OGANESSIAN, YT KORMICKI, J POPEKO, GS DANIEL, AV RAMAYYA, AV LU, Q BUTLERMOORE, K MA, WC DENG, JK SHI, D KLIMAN, J POLHORSKY, V MORHAC, M GREINER, W SANDELESCU, A COLE, JD ARYAEINEJAD, R JOHNSON, NR LEE, IY MCGOWAN, FK TI NEUTRON MULTIPLICITIES AND YIELDS OF CORRELATED ZR-CE AND MO-BA FRAGMENT PAIRS IN SPONTANEOUS FISSION OF CF-252 SO PHYSICAL REVIEW LETTERS LA English DT Article ID SPIN STATES; CHARGE AB High resolution gamma-gamma and gamma-gamma-gamma coincidences in the spontaneous fission of Cf-252 were measured. Relative yields and neutron multiplicities from zero up to 10 were extracted directly for the first time in fission for the Zr-Ce and Mo-Ba correlated fragment pairs. The 0, 8, and the new 10 neutron emission yields for Mo-Ba are significantly larger than those reported previously for total Cf-252 spontaneous fission. Our results demonstrate that the use of this high resolution gamma-gamma-gamma coincidence technique can provide important, previously inaccessible data on fission. C1 VANDERBILT UNIV,DEPT PHYS,NASHVILLE,TN 37235. INST PHYS SASC,BRATISLAVA,SLOVAKIA. JOINT INST HEAVY ION RES,OAK RIDGE,TN 37831. JW GOETHE UNIV,INST THEORET PHYS,D-660054 FRANKFURT,GERMANY. INST ATOM PHYS,BUCHAREST,ROMANIA. IDAHO NATL ENGN LAB,IDAHO FALLS,ID 83415. OAK RIDGE NATL LAB,OAK RIDGE,TN 37831. USINOR,ORISE,OAK RIDGE,TN 37831. RP TERAKOPIAN, GM (reprint author), JOINT INST NUCL RES,DUBNA 141980,RUSSIA. NR 11 TC 71 Z9 73 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 SEP 12 PY 1994 VL 73 IS 11 BP 1477 EP 1480 DI 10.1103/PhysRevLett.73.1477 PG 4 WC Physics, Multidisciplinary SC Physics GA PF793 UT WOS:A1994PF79300005 ER PT J AU OSTERHELD, AL MORGAN, WL LARSEN, JT YOUNG, BKF GOLDSTEIN, WH AF OSTERHELD, AL MORGAN, WL LARSEN, JT YOUNG, BKF GOLDSTEIN, WH TI ANALYSIS OF SPECTRA FROM LASER-PRODUCED PLASMAS USING A NEURAL-NETWORK SO PHYSICAL REVIEW LETTERS LA English DT Article ID CROSS-SECTIONS AB A backpropagation artificial neural network algorithm is applied to the analysis of K-shell x-ray line spectra from a well characterized laser produced plasma. After training on synthetic spectra produced by appropriate collisional radiative plasma emission models, the network correctly determines the electron temperature as a function of distance into the plasma. The results demonstrate the potential utility of neural networks for interpreting spectral data from plasma devices and sources. C1 KINEMA RES,MONUMENT,CO 80132. CASCADE APPL SCI INC,BOULDER,CO 80306. RP OSTERHELD, AL (reprint author), LAWRENCE LIVERMORE NATL LAB,POB 808,LIVERMORE,CA 94550, USA. NR 27 TC 3 Z9 3 U1 2 U2 2 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 0031-9007 J9 PHYS REV LETT JI Phys. Rev. Lett. PD SEP 12 PY 1994 VL 73 IS 11 BP 1505 EP 1508 DI 10.1103/PhysRevLett.73.1505 PG 4 WC Physics, Multidisciplinary SC Physics GA PF793 UT WOS:A1994PF79300012 ER PT J AU QIAN, Y BEDZYK, MJ TANG, S FREEMAN, AJ FRANKLIN, GE AF QIAN, Y BEDZYK, MJ TANG, S FREEMAN, AJ FRANKLIN, GE TI RESOLVING THE GA AD-DIMER LOCATION AND ORIENTATION ON THE SI(100) SURFACE SO PHYSICAL REVIEW LETTERS LA English DT Article ID SCANNING-TUNNELING-MICROSCOPY; LOW-COVERAGE PHASES; RAY STANDING WAVES; GROWTH; SPECTROSCOPY; MONOLAYER; ADSORBATE; SI(111); SI(001); ENERGY AB Quantitative x-ray standing wave measurements of the Ga ad-dimer bond length, orientation, and location for the Si(100)-(2 x 2):Ga surface combined with first-principles molecular cluster calculations on four different ad-dimer models lead to the conclusion that Ga atoms form ad-dimers which are aligned parallel to the underlying Si dimers and lie in between Si dimer rows at the valley bridge site. C1 ARGONNE NATL LAB,DIV MAT SCI,ARGONNE,IL 60439. NORTHWESTERN UNIV,DEPT MAT SCI & ENGN,EVANSTON,IL 60208. NORTHWESTERN UNIV,MAT RES CTR,EVANSTON,IL 60208. NORTHWESTERN UNIV,DEPT PHYS,EVANSTON,IL 60208. HARVARD UNIV,DEPT PHYS,CAMBRIDGE,MA 02142. RI Bedzyk, Michael/B-7503-2009; Bedzyk, Michael/K-6903-2013 NR 23 TC 32 Z9 32 U1 0 U2 0 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 0031-9007 J9 PHYS REV LETT JI Phys. Rev. Lett. PD SEP 12 PY 1994 VL 73 IS 11 BP 1521 EP 1524 DI 10.1103/PhysRevLett.73.1521 PG 4 WC Physics, Multidisciplinary SC Physics GA PF793 UT WOS:A1994PF79300016 ER PT J AU TAMURA, E WADDILL, GD TOBIN, JG STERNE, PA AF TAMURA, E WADDILL, GD TOBIN, JG STERNE, PA TI LINEAR AND CIRCULAR-DICHROISM IN ANGLE-RESOLVED FE 3P PHOTOEMISSION SO PHYSICAL REVIEW LETTERS LA English DT Article ID CORE-LEVEL PHOTOEMISSION; MAGNETIC DICHROISM; SPIN POLARIZATION; SELF-ENERGY; NI; SPECTRA; STATES AB Using a recently developed spin-polarized, fully relativistic, multiple scattering approach based on the layer Korringa-Kohn-Rostoker Green function method, we have reproduced the Fe 3p angle resolved soft x-ray photoemission spectra and analyzed the associated large magnetic dichroism effects for excitation with both linearly and circularly polarized light. Comparison between theory and experiment yields a spin-orbit splitting of 1.0-1.2 eV and an exchange splitting of 0.9-1.0 eV for Fe 3p. These values are 50%-100% larger than those hitherto obtained experimentally. C1 UNIV CALIF DAVIS,DEPT PHYS,DAVIS,CA 95616. RP TAMURA, E (reprint author), LAWRENCE LIVERMORE NATL LAB,DEPT CHEM & MAT SCI,LIVERMORE,CA 94550, USA. RI Tobin, James/O-6953-2015 NR 17 TC 63 Z9 63 U1 2 U2 6 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 0031-9007 J9 PHYS REV LETT JI Phys. Rev. Lett. PD SEP 12 PY 1994 VL 73 IS 11 BP 1533 EP 1536 DI 10.1103/PhysRevLett.73.1533 PG 4 WC Physics, Multidisciplinary SC Physics GA PF793 UT WOS:A1994PF79300019 ER PT J AU SPIELMAN, S PARKS, B ORENSTEIN, J NEMETH, DT LUDWIG, F CLARKE, J MERCHANT, P LEW, DJ AF SPIELMAN, S PARKS, B ORENSTEIN, J NEMETH, DT LUDWIG, F CLARKE, J MERCHANT, P LEW, DJ TI OBSERVATION OF THE QUASI-PARTICLE HALL-EFFECT IN SUPERCONDUCTING YBA2CU3O7-DELTA SO PHYSICAL REVIEW LETTERS LA English DT Article ID QUASI-PARTICLE SCATTERING; THIN-FILMS; CONDUCTIVITY; YBA2CU3O6.95 AB Coherent time-domain spectroscopy was used to measure the complex transmission tensor of several YBa2Cu3O7-delta thin films in magnetic fields up to 6 T at temperatures from 10 to 200 K. The complex conductivity tensor was determined from transmission measurements in the frequency range 150-800 GHz without the need for Kramers-Kronig analysis. Both the real and imaginary parts of sigma(xy) were found to peak near 40 K, exceeding their normal state values by more than a factor of 10. This behavior is ascribed to the Hall effect of quasiparticles in the superconducting state. C1 UNIV CALIF BERKELEY,DEPT PHYS,BERKELEY,CA 94720. HEWLETT PACKARD CORP,PALO ALTO,CA 94304. STANFORD UNIV,DEPT APPL PHYS,STANFORD,CA 94305. RP SPIELMAN, S (reprint author), LAWRENCE BERKELEY LAB,DIV MAT SCI,BERKELEY,CA 94720, USA. RI Orenstein, Joseph/I-3451-2015 NR 18 TC 50 Z9 50 U1 1 U2 3 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 0031-9007 J9 PHYS REV LETT JI Phys. Rev. Lett. PD SEP 12 PY 1994 VL 73 IS 11 BP 1537 EP 1540 DI 10.1103/PhysRevLett.73.1537 PG 4 WC Physics, Multidisciplinary SC Physics GA PF793 UT WOS:A1994PF79300020 ER PT J AU CHARLOT, S SILK, J AF CHARLOT, S SILK, J TI EVOLUTION OF GALAXIES IN CLUSTERS SO ASTROPHYSICAL JOURNAL LA English DT Article DE GALAXIES, CLUSTERING; GALAXIES, ELLIPTIC AND LENTICULAR, CD; GALAXIES, EVOLUTION; GALAXIES, STELLAR CONTENT; STARS, FORMATION ID STELLAR POPULATION SYNTHESIS; M-CIRCLE-DOT; DISTANT CLUSTERS; SPECTRAL EVOLUTION; ELLIPTICAL GALAXIES; RICH CLUSTER; SPECTROSCOPY; PHOTOMETRY; MORPHOLOGY; ABELL-370 AB We use new models of stellar population synthesis to estimate the fraction of stars formed during the last major bursts of star formation in E/SO galaxies in low-redshift clusters (z less than or similar to 0.4) from the spectral signatures of intermediate-age stars. We find that the mass fraction of stars formed in late bursts in early-type galaxies in clusters must have decreased smoothly with time, from about 8% at z approximate to 1 to less than 1% at z approximate to 0. This result, which we interpret as a constraint on stellar mass added in mergers, is nearly independent of the assumed ages and morphological types of the progenitor galaxies prior to the last major bursts of star formation. We then compute the implied color and 4000 Angstrom break evolution for progenitors of E/SO galaxies in clusters at redshifts z less than or similar to 1. We investigate a conservative model in which all present-day E/SO galaxies are assumed to be initially elliptical galaxies and then to undergo bursts of star formation at the rate estimated from the signatures of intermediate-age stars at low redshifts. This model predicts that the progenitors of present-day E/SO galaxies could be among the galaxies with the bluest colors and smallest 4000 A breaks observed in high-redshift clusters. However, the predicted fraction of blue galaxies at high redshifts is significantly lower than is observed. The most natural explanation for this shortfall is an increase with redshift of the fraction of blue spiral galaxies in clusters, as suggested independently by recent high-resolution observations of intermediate-redshift clusters. C1 UNIV CALIF BERKELEY,DEPT PHYS,BERKELEY,CA 94720. UNIV CALIF BERKELEY,CTR PARTICLE ASTROPHYS,BERKELEY,CA 94720. LAWRENCE LIVERMORE NATL LAB,INST GEOPHYS & PLANETARY PHYS,LIVERMORE,CA 94550. RP CHARLOT, S (reprint author), UNIV CALIF BERKELEY,DEPT ASTRON,601 CAMPBELL HALL,BERKELEY,CA 94720, USA. OI silk, joe/0000-0002-1566-8148 NR 58 TC 54 Z9 54 U1 0 U2 0 PU UNIV CHICAGO PRESS PI CHICAGO PA 5720 S WOODLAWN AVE, CHICAGO, IL 60637 SN 0004-637X J9 ASTROPHYS J JI Astrophys. J. PD SEP 10 PY 1994 VL 432 IS 2 BP 453 EP 463 DI 10.1086/174584 PN 1 PG 11 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA PE877 UT WOS:A1994PE87700004 ER PT J AU NICHOL, RC ULMER, MP KRON, RG WIRTH, GD KOO, DC AF NICHOL, RC ULMER, MP KRON, RG WIRTH, GD KOO, DC TI A SEARCH FOR X-RAY BRIGHT DISTANT CLUSTERS OF GALAXIES SO ASTROPHYSICAL JOURNAL LA English DT Article DE GALAXIES, CLUSTERS OF; X-RAYS, GALAXIES ID COLD DARK MATTER; RICH CLUSTERS; LUMINOSITY FUNCTION; EVOLUTION; ABELL AB We present the results of a search for X-ray luminous distant clusters of galaxies. We found extended X-ray emission characteristic of a cluster toward two of our candidate clusters of galaxies. They both have a luminosity in the ROSAT bandpass of similar or equal to 10(44) ergs s(-1) and a redshift greater than 0.5; thus making them two of the most distant X-ray clusters ever observed. Furthermore, we show that both clusters are optically rich and have a known radio source associated with them. We compare our result with other recent searches for distant X-ray luminous clusters and present a lower limit of 1.2 x 10(-7) Mpc(-3) for the number density of such high-redshift clusters. This limit is consistent with the expected abundance of such clusters in a standard (b = 2) cold dark matter universe. Finally, our clusters provide important high-redshift targets for further study into the origin and evolution of massive clusters of galaxies. C1 NORTHWESTERN UNIV,DEPT PHYS & ASTRON,EVANSTON,IL 60208. FERMILAB NATL ACCELERATOR LAB,BATAVIA,IL 60510. UNIV CALIF SANTA CRUZ,BOARD STUDIES ASTRON & ASTROPHYS,SANTA CRUZ,CA 95064. UNIV CALIF SANTA CRUZ,UNIV CALIF OBSERV,LICK OBSERV,SANTA CRUZ,CA 95064. NR 29 TC 12 Z9 12 U1 0 U2 0 PU UNIV CHICAGO PRESS PI CHICAGO PA 5720 S WOODLAWN AVE, CHICAGO, IL 60637 SN 0004-637X J9 ASTROPHYS J JI Astrophys. J. PD SEP 10 PY 1994 VL 432 IS 2 BP 464 EP 468 DI 10.1086/174585 PN 1 PG 5 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA PE877 UT WOS:A1994PE87700005 ER PT J AU STROHMAYER, TE FENIMORE, EE MIRALLES, JA AF STROHMAYER, TE FENIMORE, EE MIRALLES, JA TI CONSTRAINTS ON THE FRACTION OF REPEATING GAMMA-RAY BURST SOURCES FROM BATSE MEASUREMENTS SO ASTROPHYSICAL JOURNAL LA English DT Article DE GAMMA RAYS, BURSTS; METHODS, STATISTICAL ID CATALOG AB The discovery of excess nearest neighbor clustering; on small angular scales in the BATSE catalog GRB positions has recently been used to argue that classical GRB sources repeat on a timescale of months. We employ extensive simulations describing burst repetition to investigate the influence of burst location uncertainties on both the ability of BATSE to detect burst source repetition and to place constraints on the fraction of repeating sources. From Monte Carlo simulations we find that the current level of uncertainty in BATSE burst locations severely limits the ability to confidently detect source repetition from distributions of sources containing fewer than 10%-15% repeaters. A fit of our burst repetition model to the sample of 260 BATSE catalog bursts yields a best-fit repeating fraction f(r) = 21% with a 90% confidence region on f(r) ranging from 5.5% to 32.5%. By modifying the size of the measurement errors in our simulations we also show that the location and width of the derived confidence region for f(r) depends sensitively on the BATSE burst location uncertainties. In addition, with BATSE's present burst location accuracy, we find that analysis of larger samples of bursts will only marginally improve the constraint on the repeating fraction. RP STROHMAYER, TE (reprint author), LOS ALAMOS NATL LAB,SST-9,MS D436,POB 1663,LOS ALAMOS,NM 87545, USA. NR 13 TC 11 Z9 11 U1 0 U2 0 PU UNIV CHICAGO PRESS PI CHICAGO PA 5720 S WOODLAWN AVE, CHICAGO, IL 60637 SN 0004-637X J9 ASTROPHYS J JI Astrophys. J. PD SEP 10 PY 1994 VL 432 IS 2 BP 665 EP 671 DI 10.1086/174605 PN 1 PG 7 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA PE877 UT WOS:A1994PE87700025 ER PT J AU FENIMORE, EE LAROS, JG ULMER, A AF FENIMORE, EE LAROS, JG ULMER, A TI THE X-RAY-SPECTRUM OF THE SOFT-GAMMA-REPEATER-1806-20 SO ASTROPHYSICAL JOURNAL LA English DT Article DE GAMMA-RAYS, BURSTS; RADIATION MECHANISMS, NONTHERMAL; STARS, INDIVIDUAL (SGR 1806 -20); X-RAYS, BURSTS ID 1979 MARCH 5; HIGH-ENERGY TRANSIENT; BURST; EVENT; SCATTERING; LOCATION; COMPTON; PULSAR AB Soft gamma repeaters (SGRs) are a class of rare, high-energy galactic transients that have episodes of short (similar to 1 s), soft (similar to 30 keV), intense (similar to 100 Crab), gamma-ray bursts. We report an analysis of the X-ray emission from 95 SGR 1806-20 events observed by the international Cometary Explorer. The spectral shape remains remarkably constant for bursts that differ in intensity by a range of 50. Below similar to 15 keV the number spectrum falls off rapidly such that we can estimate the total intensity of the events. Assuming that SGR 1806-20 is associated with the supernova remnant G10.0-0.3 (Kulkarni and Frail 1993; Murakami et al. 1994), the brightest events had a total luminosity of 1.8 x 10(42) ergs s(-1), a factor of 2 x 10(4) above the Eddington limit. A third of the emission was above 30 keV. There are at least three processes that are consistent with the spectral rollover below 15 keV. (1) The rollover is consistent with some forms of self-absorption. Typical thermal temperatures are similar to 20 keV and require an emitting surface with a radius between 10 and 50 km. The lack of spectral variability implies that only the size of the emitting surface varies from event to event. If the process is thermal synchrotron, the required magnetic field might be too small to confine the plasma against the super-Eddington flux. (2) The low-energy rollover could be due to photoelectric absorption by 10(24) hydrogen atoms cm(-2) of neutral material with a cosmic abundance. This assumes a continuum similar to thermal bremsstrahlung with a temperature of similar to 22 keV. The material is most likely to be associated with the object as circumstellar matter a few AU from the central source rather than foreground clouds or directly at the site of the energy release. (3) Emission in the two lowest harmonics from a 1.3 x 10(12) G field would appear as Doppler-broadened lines and fall off rapidly below 15 keV. C1 PRINCETON UNIV,PRINCETON,NJ 08544. RP FENIMORE, EE (reprint author), LOS ALAMOS NATL LAB,MS D436,POB 1663,LOS ALAMOS,NM 87545, USA. NR 45 TC 54 Z9 54 U1 0 U2 0 PU UNIV CHICAGO PRESS PI CHICAGO PA 5720 S WOODLAWN AVE, CHICAGO, IL 60637 SN 0004-637X J9 ASTROPHYS J JI Astrophys. J. PD SEP 10 PY 1994 VL 432 IS 2 BP 742 EP 752 DI 10.1086/174612 PN 1 PG 11 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA PE877 UT WOS:A1994PE87700032 ER PT J AU DOBRY, A GRECO, A LORENZANA, J RIERA, J DIEP, HT AF DOBRY, A GRECO, A LORENZANA, J RIERA, J DIEP, HT TI EFFECTS OF POLARONIC STATES IN THE MULTIBAND HUBBARD-MODEL SO EUROPHYSICS LETTERS LA English DT Article ID CUPRATE SUPERCONDUCTORS; OPTICAL CONDUCTIVITY; OXIDES; EXCITATIONS; LA2CUO4; SYSTEMS AB The effects of electron-lattice coupling in a multiband Hubbard model are investigated by exact diagonalization. For a system with one doped hole, and with parameters relevant to cuprate superconductors, we find a continuous transition from a delocalized to a small polaron state at a critical value of the electron-phonon interaction. We characterize this state as a Zhang-Rice singlet with distortions in the CuO4 cluster. We find, in addition, a polaronic shift of the band near the Fermi level in the spectral function of the system. An enhancement of the transfer of the low-energy spectral weight is also observed. These results are in qualitative agreement with different spectroscopic measurements for high-T(c) superconductors. C1 CIUNR,RA-2000 ROSARIO,ARGENTINA. INST FIS ROSARIO,CONICET,UNR,RA-2000 ROSARIO,ARGENTINA. MAX PLANCK INST FESTKORPERFORSCH,W-7000 STUTTGART 80,GERMANY. UNIV CERGY PONTOISE,PHYS STAT GRP,49 AVE GENOTTES,F-95806 CERGY,FRANCE. UNIV GRONINGEN,APPL & SOLID STATE PHYS LAB,9747 AG GRONINGEN,NETHERLANDS. OAK RIDGE NATL LAB,DIV PHYS,OAK RIDGE,TN 37831. RP DOBRY, A (reprint author), UNIV CERGY PONTOISE,PHYS STAT GRP,49 AVE GENOTTES,F-95806 CERGY,FRANCE. RI Riera, Jose/A-1234-2008; DIEP, H. T./B-5169-2013; Lorenzana, Jose/A-2809-2008 OI Riera, Jose/0000-0003-4546-1137; Lorenzana, Jose/0000-0001-7426-2570 NR 26 TC 6 Z9 6 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 0295-5075 J9 EUROPHYS LETT JI Europhys. Lett. PD SEP 10 PY 1994 VL 27 IS 8 BP 617 EP 622 DI 10.1209/0295-5075/27/8/011 PG 6 WC Physics, Multidisciplinary SC Physics GA PG321 UT WOS:A1994PG32100011 ER PT J AU JIN, AS MAYEDA, K ADAMS, D AKI, K AF JIN, AS MAYEDA, K ADAMS, D AKI, K TI SEPARATION OF INTRINSIC AND SCATTERING ATTENUATION IN SOUTHERN CALIFORNIA USING TERRASCOPE DATA SO JOURNAL OF GEOPHYSICAL RESEARCH-SOLID EARTH LA English DT Article ID WAVE ENERGY; LITHOSPHERE; MODEL; JAPAN; CODA AB A multiple lapse time window analysis was applied to three-component broadband seismograms recorded at five TERRAscope stations in southern California to separate scattering and intrinsic attenuation. Seismic energies were integrated over three consecutive lapse time intervals: 0-15, 15-30, and 30-45 s (measured from the S arrival) for approximately 30 earthquakes with hypocentral distances of less than 70 km from each station. Using the fundamental separability of source, site, and path effects for coda waves, the integrated energies for different magnitude earthquakes were normalized to a common source size at each station, and the effect of near-site amplification is removed. Subsequently, we constructed a group of geometric spreading-corrected normalized energy-distance curves for each station region over frequency bands 0.5-1, 1-2, 2-4, and 4-8 Hz for all five stations. Two more frequency bands, 8-16 and 16-32 Hz, were added at stations PAS and SVD, for which higher sample rate data were available. A theoretical model of body wave energy propagation in a randomly heterogeneous elastic medium was employed to interpret the observation. Two parameters describe the medium in this model. These are the scattering attenuation coefficient eta(s) and the intrinsic attenuation coefficient eta(i). By assuming that scattering is isotropic and including all orders of multiple scattering, this model predicts the spatial and temporal distribution of seismic energy. A two-step least squares fitting procedure was used to find the best fitting model parameters. The result shows the following: (1) the seismic albedo, B-0 = eta(s)/(eta(i) + eta(s)), increases with decreasing frequency for all station regions. The difference in B-0 among stations is frequency dependent, and the difference disappears at 6.0 Hz. (2) Significant differences exist for the scattering attenuation coefficient eta(s) and seismic albedo B-0 among stations at lower frequencies. Stations on or close to the fault zone(s), such as PAS, PFO, and SVD, show a stronger scattering at frequencies of 0.75 and 1.5 Hz, whereas station ISA, located far away from any major active faults, shows the lowest scattering. (3) The coda Q(-1) determined from the decay rate of coda waves lies, in general, between the intrinsic Q(-1) and total Q(-1), sometimes closer to the former than the latter, and sometimes opposite, depending on the frequency and station. C1 LAWRENCE LIVERMORE NATL LAB, DIV EARTH SCI, LIVERMORE, CA 94550 USA. RP JIN, AS (reprint author), UNIV SO CALIF, DEPT GEOL SCI, LOS ANGELES, CA 90089 USA. NR 21 TC 65 Z9 69 U1 0 U2 1 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 2169-9313 EI 2169-9356 J9 J GEOPHYS RES-SOL EA JI J. Geophys. Res.-Solid Earth PD SEP 10 PY 1994 VL 99 IS B9 BP 17835 EP 17848 DI 10.1029/94JB01468 PG 14 WC Geochemistry & Geophysics SC Geochemistry & Geophysics GA PG767 UT WOS:A1994PG76700013 ER PT J AU YIN, A HARRISON, TM RYERSON, FJ CHEN, WJ KIDD, WSF COPELAND, P AF YIN, A HARRISON, TM RYERSON, FJ CHEN, WJ KIDD, WSF COPELAND, P TI TERTIARY STRUCTURAL EVOLUTION OF THE GANGDESE THRUST SYSTEM, SOUTHEASTERN TIBET SO JOURNAL OF GEOPHYSICAL RESEARCH-SOLID EARTH LA English DT Article ID MAIN CENTRAL THRUST; INDIA-EURASIA COLLISION; TECTONIC EVOLUTION; DIFFUSION DOMAINS; K-FELDSPAR; HIMALAYAN TECTONICS; GRAVITY-ANOMALIES; SOUTHERN TIBET; ASIA COLLISION; CENTRAL NEPAL AB Structural and thermochronological investigations of southern Tibet (Xizang) suggest that intracontinental thrusting has been the dominant cause for formation of thickened crust in the southernmost Tibetan plateau since late Oligocene. Two thrust systems are documented in this study: the north dipping Gangdese system (GTS) and the younger south dipping Renbu-Zedong system (RZT). West of Lhasa, the Gangdese thrust juxtaposes the Late Cretaceous forearc basin deposits of the Lhasa Block (the Xigaze Group) over the Tethyan sedimentary rocks of the Indian plate, whereas east of Lhasa, the fault juxtaposes the Late Cretaceous-Eocene, Andean-type are (the Gangdese batholith) over Tethyan sedimentary rocks. Near Zedong, 150 km southeast of Lhasa, the Gangdese thrust is marked by a >200-m-thick mylonitic shear zone that consists of deformed granite and metasedimentary rocks. A major south dipping backthrust in the hanging wall of the Gangdese thrust puts the Xigaze Group over Tertiary conglomerates and the Gangdese plutonics north of Xigaze and west of Lhasa. A lower age bound for the Gangdese thrust of 18.3+/-0.5 Ma is given by crosscutting relationships. The timing of slip on the Gangdese thrust is estimated to be 27-23 Ma from Ar-40/Ar-39 thermochronology, and a displacement of at least 46+/-9 km is indicated near Zedong. The age of the Gangdese thrust (GT) is consistent with an upper age limit of similar to 24 Ma for the initiation of movement on the Main Central thrust. In places, the younger Renbu-Zedong fault is thrust over the trace of the GT, obscuring its exposure. The RZT appears to have been active at circa 18 Ma but had ceased movement by 8+/-1 Ma. The suture between India and Asia has been complexly modified by development of the GTS, RZT, and, locally, strike-slip and normal fault systems. C1 UNIV HOUSTON, DEPT GEOSCI, HOUSTON, TX 77204 USA. UNIV CALIF LOS ANGELES, INST GEOPHYS & PLANETARY PHYS, LOS ANGELES, CA 90024 USA. SUNY ALBANY, DEPT GEOL SCI, ALBANY, NY 12222 USA. LAWRENCE LIVERMORE NATL LAB, INST GEOPHYS & PLANETARY PHYS, LIVERMORE, CA 94550 USA. STATE SEISMOL BUR, INST GEOL, BEIJING 100029, PEOPLES R CHINA. RP YIN, A (reprint author), UNIV CALIF LOS ANGELES, DEPT EARTH & SPACE SCI, LOS ANGELES, CA 90024 USA. RI Copeland, Peter/A-9823-2008; Harrison, Timothy/E-7443-2012; Yin, An/B-3050-2014 NR 61 TC 235 Z9 315 U1 1 U2 26 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 2169-9313 EI 2169-9356 J9 J GEOPHYS RES-SOL EA JI J. Geophys. Res.-Solid Earth PD SEP 10 PY 1994 VL 99 IS B9 BP 18175 EP 18201 DI 10.1029/94JB00504 PG 27 WC Geochemistry & Geophysics SC Geochemistry & Geophysics GA PG767 UT WOS:A1994PG76700039 ER PT J AU MASUR, LJ PODTBURG, ER CRAVEN, CA OTTO, A WANG, ZL KROEGER, DM COULTER, JY MALEY, MP AF MASUR, LJ PODTBURG, ER CRAVEN, CA OTTO, A WANG, ZL KROEGER, DM COULTER, JY MALEY, MP TI BI-AXIAL TEXTURE IN CA0.1Y0.9BA2CU4O8 COMPOSITE WIRES MADE BY METALLIC PRECURSORS SO PHYSICA C LA English DT Article ID YBA2CU3O7; JC AB High filament count, silver-sheathed composite wires of Ca0.1Y0.9Ba2Cu4O8 (Y-124) were prepared by a metallic precursor route. The ductility of the metallic precursor enabled one to manufacture tapes containing up to 962 407 filaments, with filament dimensions as fine as 0.25 mum thick and 1 mum wide. By using a thermal-mechanical treatment to texture the Y-124 grains, transport critical current densities in the oxide filaments of 69 500 A/cm2 at 4.2 K in self-field were obtained. Moreover, in an applied field of 0.1 T, the samples retained 39% of their self-field critical current density. A TEM investigation revealed significant bi-axial crystallographic texture: in areas viewed, c-axis alignment of adjacent grains was within 10-degrees and oriented perpendicular to the tape face; a-axis alignment of adjacent grains was within 15-degrees and oriented parallel to the longitudinal direction of the filaments. Furthermore, c-axis texture alone did not adequately predict the performance of these Y-124 composite conductors. Instead, performance scaled with the degree of bi-axial texture. These wires exhibited among the best reported J(c) for a polycrystalline, sintered wire of YBCO in an applied magnetic field. C1 OAK RIDGE NATL LAB,COLL MET & CERAM,OAK RIDGE,TN 37831. LOS ALAMOS NATL LAB,CTR SUPERCONDUCT TECHNOL,LOS ALAMOS,NM 87544. RP MASUR, LJ (reprint author), AMER SUPERCOND CORP,2 TECHNOL DR,WESTBOROUGH,MA, USA. RI Wang, Zhong Lin/E-2176-2011 OI Wang, Zhong Lin/0000-0002-5530-0380 NR 20 TC 8 Z9 8 U1 0 U2 1 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0921-4534 J9 PHYSICA C JI Physica C PD SEP 10 PY 1994 VL 230 IS 3-4 BP 274 EP 282 DI 10.1016/0921-4534(94)90840-0 PG 9 WC Physics, Applied SC Physics GA PH401 UT WOS:A1994PH40100007 ER PT J AU SCHLUETER, JA CARLSON, KD WILLIAMS, JM GEISER, U WANG, HH WELP, U KWOK, WK FENDRICH, JA DUDEK, JD ACHENBACH, CA KEANE, PM KOMOSA, AS NAUMANN, D ROY, T SCHIRBER, JE BAYLESS, WR AF SCHLUETER, JA CARLSON, KD WILLIAMS, JM GEISER, U WANG, HH WELP, U KWOK, WK FENDRICH, JA DUDEK, JD ACHENBACH, CA KEANE, PM KOMOSA, AS NAUMANN, D ROY, T SCHIRBER, JE BAYLESS, WR TI A NEW 9-K SUPERCONDUCTING ORGANIC SALT COMPOSED OF THE BIS(ETHYLENEDITHIO) TETRATHIAFULVALENE (ET) ELECTRON-DONOR MOLECULE AND THE TETRAKIS (TRIFLUOROMETHYL) CUPRATE (III) ANION, [CU(CF3)4]- SO PHYSICA C LA English DT Article ID RESISTANCE; PRESSURE; TC AB We report the discovery of a second, higher-T(c) superconducting organic charge-transfer salt derived from the electron-donor molecule BEDT-TTF (or ET), the novel organometallic anion [Cu(CF3)4]-, and the neutral solvent molecule 1,1,2-trichloroethane (TCE). We have very recently reported that this charge-transfer system yields a new superconducting k phase salt, k(L)-(ET)2Cu(CF3)4.TCE, with inductive onset T(c) = 4.0 K at ambient pressure. This k phase salt (k denotes a particular packing arrangement of the ET organic donor molecules) is electrocrystallized in the habit of hexagonal plates. Crystals possessing a needle-like habit electrocrystallize simultaneously with these plates, and we find these needles to be a distinctly different superconducting phase with diamagnetic onset T(c) = 9.2 +/- 0.1 K at ambient pressure. On the basis of our experiments, we denote this new superconducting phase as k(H)-(ET)2Cu(CF3)4.(TCE)(x),X<1 C1 ARGONNE NATL LAB,DIV CHEM,ARGONNE,IL 60439. UNIV COLOGNE,INST ANORGAN CHEM,D-50939 COLOGNE,GERMANY. ARGONNE NATL LAB,DIV MAT SCI,ARGONNE,IL 60439. SANDIA NATL LABS,ALBUQUERQUE,NM 87185. NR 15 TC 29 Z9 29 U1 0 U2 0 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0921-4534 J9 PHYSICA C JI Physica C PD SEP 10 PY 1994 VL 230 IS 3-4 BP 378 EP 384 DI 10.1016/0921-4534(94)90854-0 PG 7 WC Physics, Applied SC Physics GA PH401 UT WOS:A1994PH40100021 ER PT J AU CANFIELD, PC CHO, BK JOHNSTON, DC FINNEMORE, DK HUNDLEY, MF AF CANFIELD, PC CHO, BK JOHNSTON, DC FINNEMORE, DK HUNDLEY, MF TI SPECIFIC-HEAT AND ANISOTROPIC SUPERCONDUCTING AND NORMAL-STATE MAGNETIZATION OF HONI2B2C SO PHYSICA C LA English DT Article AB The magnetization of single-crystal HoNi2B2C has been measured as a function of applied field (H) and temperature in order to probe the interplay between superconductivity and magnetism in this complex layered system. The normal-state magnetic susceptibility of HoNi2B2C is highly anisotropic with a Curie-Weiss-like temperature dependence for H applied perpendicular to the c-axis and with a much weaker temperature dependence for H applied parallel to the c-axis, indicating that the Ho+3 magnetic moments lie predominately in the tetragonal a-b plane below 20 K. High-field magnetization (2000 Oe), low-field magnetization (20 Oe) and zero-field specific heat all give an antiferromagnetic ordering temperature of T(N)=5.0 K. Remarkably, in 20 Oe applied field both superconductivity (T(c)=8.0 K) and antiferromagnetism (T(N)=5.0 K) clearly make themselves manifest in the magnetization data. From these magnetization data a phase diagram in the H-T plane was constructed for both directions of applied field. This phase diagram shows a non-monotonic temperature dependence of H(c2) with a deep minimum at T(N)=5 K. The high-field magnetization data for H applied perpendicular to the c-axis also reveal a cascade of three phase transitions for T < 5 K and H < 15 000 Oe, contributing to the rich H versus T phase diagram for HoNi2B2C at low temperatures. C1 IOWA STATE UNIV SCI & TECHNOL,DEPT PHYS & ASTRON,AMES,IA 50011. LOS ALAMOS NATL LAB,LOS ALAMOS,NM 87545. RP CANFIELD, PC (reprint author), IOWA STATE UNIV SCI & TECHNOL,AMES LAB,AMES,IA 50011, USA. RI Canfield, Paul/H-2698-2014 NR 14 TC 148 Z9 148 U1 1 U2 15 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0921-4534 J9 PHYSICA C JI Physica C PD SEP 10 PY 1994 VL 230 IS 3-4 BP 397 EP 406 DI 10.1016/0921-4534(94)90857-5 PG 10 WC Physics, Applied SC Physics GA PH401 UT WOS:A1994PH40100024 ER PT J AU DURBIN, TD SIMPSON, WC CHAKARIAN, V SHUH, DK VAREKAMP, PR LO, CW YARMOFF, JA AF DURBIN, TD SIMPSON, WC CHAKARIAN, V SHUH, DK VAREKAMP, PR LO, CW YARMOFF, JA TI STIMULATED DESORPTION OF CL+ AND THE CHEMISORPTION OF CL-2 ON SI(111)-7X7 AND SI(100)-2X1 SO SURFACE SCIENCE LA English DT Article ID BONDING SITES; CHLORINE CHEMISORPTION; RAY PHOTOEMISSION; ELECTRON-ENERGY; FLUORINE; SURFACE; ADSORPTION; SILICON; SPECTROSCOPY; SI AB The chemisorption of Cl-2 on Si(111)-7 x 7 and Si(100)-2 x 1 and the mechanism for stimulated desorption of Cl+ from Si are studied with soft X-ray photoelectron spectroscopy (SXPS) and photon-stimulated desorption (PSD). It is shown that Cl-2 interacts with Si(111)-7 x 7 at room temperature to form mono-, di- and tri-chlorides, while primarily monochlorides are formed on Si(100)-2 x 1. These differences are explained in terms of the reconstructions of each clean surface. The stimulated desorption of Cl+ ions has a threshold at similar to 20 eV that results from a direct excitation of a Cl 3s electron to an unoccupied Cl antibonding level. No direct desorption of Cl+ ions is observed at the Si 2p edge. Differences between the mechanisms for F+ and Cl+ desorption from Si are discussed. C1 UNIV CALIF RIVERSIDE,DEPT PHYS,RIVERSIDE,CA 92521. UNIV CALIF BERKELEY,LAWRENCE BERKELEY LAB,DIV MAT SCI,BERKELEY,CA 94720. NR 42 TC 46 Z9 47 U1 1 U2 4 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0039-6028 J9 SURF SCI JI Surf. Sci. PD SEP 10 PY 1994 VL 316 IS 3 BP 257 EP 266 DI 10.1016/0039-6028(94)91218-1 PG 10 WC Chemistry, Physical; Physics, Condensed Matter SC Chemistry; Physics GA PF849 UT WOS:A1994PF84900011 ER PT J AU BAFRALI, R BELL, AT AF BAFRALI, R BELL, AT TI ADSORPTION AND DECOMPOSITION OF CH3NH2 ON MO(100)-C(2X2)N SO SURFACE SCIENCE LA English DT Article ID SURFACE; HYDRODENITROGENATION; METHYLAMINE; CHEMISORPTION; SPECTROSCOPY; GAMMA-MO2N; QUINOLINE; CATALYSIS; CARBIDES; NITRIDES AB The adsorption and decomposition of CH3NH2 on a Mo(100)-c(2x2)N surface has been studied using temperature-programmed desorption and Auger electron spectroscopy. The initial sticking coefficient for CH3NH2, at 210 K, is estimated to be similar to 10(-1), with the absolute value expected to be within a factor of three, and the maximum adsorption capacity is 0.28 ML. Temperature-programmed desorption studies show that adsorbed CH3NH2 undergoes desorption and concurrent decomposition. The major decomposition products are H-2, NH3, C-s, and N-s. In addition, C2H4 is a minor decomposition product. D-2/CH3NH2 coadsorption studies suggest that the decomposition of adsorbed CH3NH2 is initiated by intramolecular hydrogen transfer to form adsorbed CH2 and NH3. Most of the CH2 species undergo dehydrogenation to form C and H-2. Some of the adsorbed NH3 decomposes to form N and H-2, but most of the NH3 desorbs into the gas phase. C1 UNIV CALIF BERKELEY,DEPT CHEM ENGN,BERKELEY,CA 94720. UNIV CALIF BERKELEY,LAWRENCE BERKELEY LAB,CTR ADV MAT,DIV MAT SCI,BERKELEY,CA 94720. NR 18 TC 19 Z9 20 U1 0 U2 1 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0039-6028 J9 SURF SCI JI Surf. Sci. PD SEP 10 PY 1994 VL 316 IS 3 BP 267 EP 276 DI 10.1016/0039-6028(94)91219-X PG 10 WC Chemistry, Physical; Physics, Condensed Matter SC Chemistry; Physics GA PF849 UT WOS:A1994PF84900012 ER PT J AU LIU, CL AF LIU, CL TI ENERGETICS OF DIFFUSION-PROCESSES DURING NUCLEATION AND GROWTH FOR THE CU/CU(100) SYSTEM SO SURFACE SCIENCE LA English DT Article ID EMBEDDED-ATOM-METHOD; SELF-DIFFUSION; NI SURFACES; SINGLE ADATOMS; CU(100); METALS; CLUSTERS; DYNAMICS; CU; MECHANISMS AB Various diffusion processes during sub-monolayer epitaxy of Cu/Cu(100) were studied using the embedded atom method. These processes include (1) single atom diffusion on a flat Cu(100), (2) adatom diffusion around steps running both in [110] and [100] directions, and (3) migration of small clusters of up to 5 atoms on a flat terrace. The results show that the energy barrier for adatom diffusion along the step ledge of [110] directions is actually lower than that for adatom diffusion on a flat terrace and that diffusion across the descending steps depends on step orientation. The exchange mechanism is favored energetically over direct jumps across [110] steps, while direct jumps are favored across [100] steps. Dissociation energies and diffusion barriers for small clusters are oscillatory among clusters of odd and even number atoms. Comparison of dissociation energies and diffusion barriers indicates that (1) tetramers are relatively stable compared to dimers, trimers, and pentamers, and (2) small clusters of up to 5 atoms are quite mobile near room temperature. The calculated results support the conclusions from a recent high-resolution low-energy electron diffraction investigation on sub-monolayer epitaxy for Cu/Cu(100). RP LIU, CL (reprint author), OAK RIDGE NATL LAB,DIV SOLID STATE,POB 2008,OAK RIDGE,TN 37831, USA. NR 28 TC 32 Z9 32 U1 0 U2 1 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0039-6028 J9 SURF SCI JI Surf. Sci. PD SEP 10 PY 1994 VL 316 IS 3 BP 294 EP 302 DI 10.1016/0039-6028(94)91221-1 PG 9 WC Chemistry, Physical; Physics, Condensed Matter SC Chemistry; Physics GA PF849 UT WOS:A1994PF84900014 ER PT J AU VODINH, T VIALLET, P RAMIREZ, L PAL, A VIGO, J AF VODINH, T VIALLET, P RAMIREZ, L PAL, A VIGO, J TI DETECTION OF CADMIUM ION USING THE FLUORESCENCE PROBE INDO-1 SO ANALYTICA CHIMICA ACTA LA English DT Article DE BIOSENSORS; FLUOROMETRY; CADMIUM; INDO-1 ID INDICATORS; ACTIVATION; CELLS AB Fluorescence probes for biosensors used for the determination of intracellular concentration of metal ions have been synthesized in order to bind selectively with a specific cation. Since certain ions exhibit similar chemical properties, binding selectivity with the probes is difficult. In this paper we describe for the first time the interaction between Indo-1, a fluorescence probe representative of a family of ''specific chelating compounds'' (mainly used for calcium) with the cadmium ion. The fluorescence properties of the cadmium complex are described and a method is proposed to determine the concentrations of both calcium and cadmium ions in aqueous solutions. C1 UNIV PERPIGNAN, CHEM PHYS LAB, F-66860 PERPIGNAN, FRANCE. RP OAK RIDGE NATL LAB, DIV HLTH & SAFETY RES, ADV MONITORING DEV GRP, POB 2008, OAK RIDGE, TN 37831 USA. NR 12 TC 9 Z9 9 U1 0 U2 4 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0003-2670 EI 1873-4324 J9 ANAL CHIM ACTA JI Anal. Chim. Acta PD SEP 9 PY 1994 VL 295 IS 1-2 BP 67 EP 72 DI 10.1016/0003-2670(94)80335-8 PG 6 WC Chemistry, Analytical SC Chemistry GA PF683 UT WOS:A1994PF68300006 ER PT J AU QIAN, YL STURCHIO, NC CHIARELLO, RP LYMAN, PF LEE, TL BEDZYK, MJ AF QIAN, YL STURCHIO, NC CHIARELLO, RP LYMAN, PF LEE, TL BEDZYK, MJ TI LATTICE LOCATION OF TRACE-ELEMENTS WITHIN MINERALS AND AT THEIR SURFACES WITH X-RAY STANDING WAVES SO SCIENCE LA English DT Article ID CALCITE; INTERFACE; SORPTION AB The x-ray standing waves generated by dynamical Bragg diffraction were used to directly measure lattice locations of trace elements within and at the surface of a mineral single crystal. These high-precision measurements were made on natural Iceland spar calcite cleaved along the (<10(1)over bar 4>) plane and reacted with a dilute aqueous lead solution. Within the bulk crystal, naturally occurring trace manganese was found within (<10(1)over bar 4>) planes, consistent with its substitution for calcium. At the crystal surface, sorbed lead was found to be highly ordered and mostly within (<10(1)over bar 4>) planes. This demonstrates a powerful application of synchrotron radiation in the earth and environmental sciences. C1 ARGONNE NATL LAB,DIV MAT SCI,ARGONNE,IL 60439. NORTHWESTERN UNIV,DEPT MAT SCI & ENGN,EVANSTON,IL 60208. NORTHWESTERN UNIV,MAT RES CTR,EVANSTON,IL 60208. RI Bedzyk, Michael/B-7503-2009; Bedzyk, Michael/K-6903-2013 FU PHS HHS [IR01KD45295-01] NR 19 TC 38 Z9 39 U1 0 U2 5 PU AMER ASSOC ADVANCEMENT SCIENCE PI WASHINGTON PA 1200 NEW YORK AVE, NW, WASHINGTON, DC 20005 SN 0036-8075 J9 SCIENCE JI Science PD SEP 9 PY 1994 VL 265 IS 5178 BP 1555 EP 1557 DI 10.1126/science.8079168 PG 3 WC Multidisciplinary Sciences SC Science & Technology - Other Topics GA PF336 UT WOS:A1994PF33600026 PM 8079168 ER PT J AU RICHARDSON, PL GROSS, ML LIGHTWAHL, KJ SMITH, RD SCHEPARTZ, A AF RICHARDSON, PL GROSS, ML LIGHTWAHL, KJ SMITH, RD SCHEPARTZ, A TI A UNIQUELY MODIFIED RNA - INTRODUCTION OF A SINGLE RNA CLEAVAGE AGENT INTO THE M1 RIBOZYME SO BIOORGANIC & MEDICINAL CHEMISTRY LETTERS LA English DT Article ID SITE-SPECIFIC MODIFICATION; HAMMERHEAD RIBOZYME; TETRAHYMENA RIBOZYME; 2'-HYDROXYL GROUPS; CHEMICAL SYNTHESIS; SUBSTRATE BINDING; PROTEIN CLEAVAGE; REPORTER GROUPS; IRON CHELATE; DNA AB We describe an efficient, Sour-step synthesis of an N-4-modified cytidine phosphoramidite reagent (1) that permits nonnative functionality tp be introduced into a synthetic oligoribonucleotide. This reagent was used to prepare a 377-nt E. coli M1 ribozyme equipped with a single RNA cleavage agent at nucleotide 11. C1 YALE UNIV, DEPT CHEM, NEW HAVEN, CT 06511 USA. PACIFIC NW LAB, DEPT CHEM SCI, RICHLAND, WA 99352 USA. RI Smith, Richard/J-3664-2012 OI Smith, Richard/0000-0002-2381-2349 NR 47 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 0960-894X J9 BIOORG MED CHEM LETT JI Bioorg. Med. Chem. Lett. PD SEP 8 PY 1994 VL 4 IS 17 BP 2133 EP 2138 DI 10.1016/S0960-894X(01)80116-5 PG 6 WC Chemistry, Medicinal; Chemistry, Organic SC Pharmacology & Pharmacy; Chemistry GA PG041 UT WOS:A1994PG04100014 ER PT J AU WOON, DE AF WOON, DE TI AB-INITIO MODELING OF (LIF)(2) AND (LIF)(2)(H2O) SO JOURNAL OF PHYSICAL CHEMISTRY LA English DT Letter ID CORRELATED MOLECULAR CALCULATIONS; GAUSSIAN-BASIS SETS; WAVE-FUNCTIONS; SYSTEMATIC SEQUENCES; WATER AB Second-order Moller-Plesset perturbation theory (MP2) and correlation consistent basis sets have been employed to investigate energetics and minimum-energy structures for (LIF)(2) and its complex with one water, (LiF)(2)-(H2O). The computed dimerization energy for 2LiF --> (LiF)(2) of -61.8 kcal/mol [-59.9 kcal/mol with zero-point correction (ZPC)] compares very well with the experimental value of -59 kcal/mol. The cyclic C-1 minimum structure for (LiF)(2)(H2O) is very similar to that of LiF(H2O). The binding energy for (LiF)(2)(H2O) of -16.7 kcal/mol (-14.6 kcal/mol with ZPC) is nearly 20% smaller than the value of -20.3 kcal/mol (-17.9 kcal/mol with ZPC) for LiF(H2O). A transition state with C-2v symmetry is also discussed. A simple electrostatic argument indicates that this configuration will remain a transition state even with an extended substrate present. RP WOON, DE (reprint author), PACIFIC NW LAB, MOLEC SCI RES CTR, POB 999, RICHLAND, WA 99352 USA. NR 17 TC 6 Z9 6 U1 0 U2 0 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 SN 0022-3654 J9 J PHYS CHEM-US JI J. Phys. Chem. PD SEP 8 PY 1994 VL 98 IS 36 BP 8831 EP 8833 DI 10.1021/j100087a003 PG 3 WC Chemistry, Physical SC Chemistry GA PF331 UT WOS:A1994PF33100003 ER PT J AU MARTIN, JH COALE, KH JOHNSON, KS FITZWATER, SE GORDON, RM TANNER, SJ HUNTER, CN ELROD, VA NOWICKI, JL COLEY, TL BARBER, RT LINDLEY, S WATSON, AJ VANSCOY, K LAW, CS LIDDICOAT, MI LING, R STANTON, T STOCKEL, J COLLINS, C ANDERSON, A BIDIGARE, R ONDRUSEK, M LATASA, M MILLERO, FJ LEE, K YAO, W ZHANG, JZ FRIEDERICH, G SAKAMOTO, C CHAVEZ, F BUCK, K KOLBER, Z GREENE, R FALKOWSKI, P CHISHOLM, SW HOGE, F SWIFT, R YUNGEL, J TURNER, S NIGHTINGALE, P HATTON, A LISS, P TINDALE, NW AF MARTIN, JH COALE, KH JOHNSON, KS FITZWATER, SE GORDON, RM TANNER, SJ HUNTER, CN ELROD, VA NOWICKI, JL COLEY, TL BARBER, RT LINDLEY, S WATSON, AJ VANSCOY, K LAW, CS LIDDICOAT, MI LING, R STANTON, T STOCKEL, J COLLINS, C ANDERSON, A BIDIGARE, R ONDRUSEK, M LATASA, M MILLERO, FJ LEE, K YAO, W ZHANG, JZ FRIEDERICH, G SAKAMOTO, C CHAVEZ, F BUCK, K KOLBER, Z GREENE, R FALKOWSKI, P CHISHOLM, SW HOGE, F SWIFT, R YUNGEL, J TURNER, S NIGHTINGALE, P HATTON, A LISS, P TINDALE, NW TI TESTING THE IRON HYPOTHESIS IN ECOSYSTEMS OF THE EQUATORIAL PACIFIC-OCEAN SO NATURE LA English DT Article ID SUB-ARCTIC PACIFIC; MARINE-PHYTOPLANKTON; PRODUCTIVITY; ENVIRONMENTS; LIMITATION; SEAWATER; GROWTH; WATER; SEA AB The idea that iron might limit phytoplankton growth in large regions of the ocean has been tested by enriching an area of 64 km(2) in the open equatorial Pacific Ocean with iron. This resulted in a doubling of plant biomass, a threefold increase In chlorophyll and a fourfold increase in plant production. Similar increases were found in a chlorophyll-rich plume downstream of the Galapagos Islands, which was naturally enriched in iron. These findings indicate that iron limitation can control rates of phytoplankton productivity and biomass in the ocean. C1 MOSS LANDING MARINE LABS,MOSS LANDING,CA 95039. DUKE UNIV,MARINE LAB,BEAUFORT,NC 28516. PLYMOUTH MARINE LAB,PLYMOUTH PL1 3DH,ENGLAND. USN,POSTGRAD SCH,MONTEREY,CA 93943. UNIV HAWAII,DEPT OCEANOG,HONOLULU,HI 96822. UNIV MIAMI,ROSENSTIEL SCH MARINE & ATMOSPHER SCI,MIAMI,FL 33149. MONTEREY BAY AQUARIUM RES INST,PACIFIC GROVE,CA 93950. BROOKHAVEN NATL LAB,DIV OCEANOG & ATMOSPHER SCI,UPTON,NY 11973. MIT,DEPT CIVIL & ENVIRONM ENGN,RALPH M PARSONS LAB,CAMBRIDGE,MA 02139. NASA,GODDARD SPACE FLIGHT CTR,WALLOPS FLIGHT FACIL,WALLOPS ISL,VA 23337. UNIV E ANGLIA,SCH ENVIRONM SCI,NORWICH NR4 7TJ,NORFOLK,ENGLAND. TEXAS A&M UNIV,DEPT METEOROL,COLLEGE STN,TX 77843. RI Zhang, Jia-Zhong/B-7708-2008; Ondrusek, Michael/F-5617-2010; LISS, Peter/A-8219-2013; Hatton, Angela/D-6196-2013; Nightingale, Philip/I-4324-2012; Lindley, Steven/G-3997-2014; Latasa, Mikel/D-2202-2011; Johnson, Kenneth/F-9742-2011 OI Zhang, Jia-Zhong/0000-0002-1138-2556; Ondrusek, Michael/0000-0002-5311-9094; Nightingale, Philip/0000-0001-7177-5469; Lindley, Steven/0000-0001-9556-0411; Latasa, Mikel/0000-0002-8202-0923; Johnson, Kenneth/0000-0001-5513-5584 NR 52 TC 917 Z9 980 U1 16 U2 181 PU MACMILLAN MAGAZINES LTD PI LONDON PA PORTERS SOUTH, 4 CRINAN ST, LONDON, ENGLAND N1 9XW SN 0028-0836 J9 NATURE JI Nature PD SEP 8 PY 1994 VL 371 IS 6493 BP 123 EP 129 DI 10.1038/371123a0 PG 7 WC Multidisciplinary Sciences SC Science & Technology - Other Topics GA PF191 UT WOS:A1994PF19100054 ER PT J AU KOLBER, ZS BARBER, RT COALE, KH FITZWATER, SE GREENE, RM JOHNSON, KS LINDLEY, S FALKOWSKI, PG AF KOLBER, ZS BARBER, RT COALE, KH FITZWATER, SE GREENE, RM JOHNSON, KS LINDLEY, S FALKOWSKI, PG TI IRON LIMITATION OF PHYTOPLANKTON PHOTOSYNTHESIS IN THE EQUATORIAL PACIFIC-OCEAN SO NATURE LA English DT Article ID MARINE-PHYTOPLANKTON; FLUORESCENCE; ENERGY; GROWTH; PRODUCTIVITY; TRANSPORT; KINETICS; ALGAE AB THE surface waters of the equatorial Pacific have unusually high nitrate and phosphate concentrations, but relatively low phytoplankton biomass(1-3). This high nitrate, low chlorophyll' (HNLC)(4) Phenomenon has been ascribed to 'top-down' grazing pressure by herbivores, which prevent the phytoplankton from fully utilizing the available nutrients(5). In the late 1980s, however, Martin and co-workers proposed that iron, which is delivered to the remote open ocean in aeolean dust(6), is he key factor limiting the standing crop of phytoplankton in HNLC areas(7,8). Using a sensitive fluorescence method(9), we have followed changes in photochemical energy conversion efficiency(9,10) of the natural phytoplankton community both before and after artificial enrichment with iron of a small area (7.5 x 7.5 km) of the equatorial Pacific Ocean(11). Our results show that iron limits phytoplankton photosynthesis in all size classes in this region bg impairing intrinsic photochemical energy conversion, thereby supporting the hypothesis of physiological ('bottom up') limitation by this element. C1 DUKE UNIV, MARINE LAB, BEAUFORT, NC 28516 USA. MOSS LANDING MARINE LABS, MOSS LANDING, CA 95039 USA. MONTEREY BAY AQUARIUM RES INST, PACIFIC GROVE, CA 93950 USA. RP KOLBER, ZS (reprint author), BROOKHAVEN NATL LAB, DIV OCEANOG & ATMOSPHER SCI, UPTON, NY 11973 USA. RI Greene, Richard/G-9685-2013; Lindley, Steven/G-3997-2014; Johnson, Kenneth/F-9742-2011 OI Lindley, Steven/0000-0001-9556-0411; Johnson, Kenneth/0000-0001-5513-5584 NR 35 TC 248 Z9 261 U1 5 U2 37 PU NATURE PUBLISHING GROUP PI LONDON PA MACMILLAN BUILDING, 4 CRINAN ST, LONDON N1 9XW, ENGLAND SN 0028-0836 J9 NATURE JI Nature PD SEP 8 PY 1994 VL 371 IS 6493 BP 145 EP 149 DI 10.1038/371145a0 PG 5 WC Multidisciplinary Sciences SC Science & Technology - Other Topics GA PF191 UT WOS:A1994PF19100060 ER PT J AU HAIDER, Q LIU, LC AF HAIDER, Q LIU, LC TI PIONIC CONTENT OF RHO-NN AND RHO-N-DELTA VERTEX FUNCTIONS SO PHYSICS LETTERS B LA English DT Article ID PI VERTEX; SCATTERING; NUCLEON AB The dynamical content of rhoNN and rhoNDELTA vertex functions is studied with a mesonic model. A set of coupled integral equations satisfied by these vertex functions was solved self-consistently. These solutions indicate that the dominant mesonic content arises from di-pion dynamics. With the experimentally determined pion-baryon-baryon coupling constants and ranges as input, the model predicts a g(rhoNN) that agrees with the meson-exchange-potential results. On the other hand, it predicts a smaller f(rhoNDELTA) and much softer form factors. Implications of the findings on the use of phenomenological coupling constants in nuclear reaction studies are discussed. C1 LOS ALAMOS NATL LAB,DIV THEORET,LOS ALAMOS,NM 87545. RP HAIDER, Q (reprint author), FORDHAM UNIV,DEPT PHYS,BRONX,NY 10458, USA. NR 13 TC 12 Z9 12 U1 0 U2 0 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0370-2693 J9 PHYS LETT B JI Phys. Lett. B PD SEP 8 PY 1994 VL 335 IS 3-4 BP 253 EP 258 DI 10.1016/0370-2693(94)90346-8 PG 6 WC Astronomy & Astrophysics; Physics, Nuclear; Physics, Particles & Fields SC Astronomy & Astrophysics; Physics GA PF866 UT WOS:A1994PF86600001 ER PT J AU WERNER, TR SHEIKH, JA NAZAREWICZ, W STRAYER, MR UMAR, AS MISU, M AF WERNER, TR SHEIKH, JA NAZAREWICZ, W STRAYER, MR UMAR, AS MISU, M TI SHAPE COEXISTENCE AROUND S-44(16)28 - THE DEFORMED N=28 REGION SO PHYSICS LETTERS B LA English DT Article ID EXOTIC NUCLEI; BETA-DECAY; NEUTRON; ISOTOPES; STATES AB Masses, deformations, radii, and single-particle properties of the very neutron-rich sulfur isotopes are investigated in the framework of the self-consistent mean-field theory. The stability of the N = 28 magic gap around 44S is discussed. C1 JOINT INST HEAVY ION RES,OAK RIDGE,TN 37831. UNIV TENNESSEE,DEPT PHYS & ASTRON,KNOXVILLE,TN 37996. VANDERBILT UNIV,DEPT PHYS,NASHVILLE,TN 37235. RP WERNER, TR (reprint author), OAK RIDGE NATL LAB,DIV PHYS,POB 2008,OAK RIDGE,TN 37831, USA. RI Umar, Ahmet/J-4125-2013 OI Umar, Ahmet/0000-0002-9267-5253 NR 37 TC 80 Z9 80 U1 0 U2 1 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0370-2693 J9 PHYS LETT B JI Phys. Lett. B PD SEP 8 PY 1994 VL 335 IS 3-4 BP 259 EP 265 DI 10.1016/0370-2693(94)90347-6 PG 7 WC Astronomy & Astrophysics; Physics, Nuclear; Physics, Particles & Fields SC Astronomy & Astrophysics; Physics GA PF866 UT WOS:A1994PF86600002 ER PT J AU MITCHELL, KL TANDY, PC ROBERTS, CD CAHILL, RT AF MITCHELL, KL TANDY, PC ROBERTS, CD CAHILL, RT TI CHARGE-SYMMETRY BREAKING VIA RHO-OMEGA-MIXING FROM MODEL QUARK-GLUON DYNAMICS SO PHYSICS LETTERS B LA English DT Article ID QCD; PROPAGATOR; BOSONIZATION; SCATTERING AB The quark-loop contribution to the rho(o)-omega mixing self-energy is calculated within a QCD-based model field theory in which the mesons are composite qBARq bound states and the dressed quark propagator, obtained from a model Dyson-Schwinger equation, is confining. In contrast to previous studies, the strength and range of the meson-qBARq vertex functions are produced within the model, and the off-mass-shell mixing behaviour includes the contribution from the diagonal meson self-energies. Although the mass-shell mixing is very sensitive to the small isovector component of dynamical chiral symmetry breaking, the spacelike mixing still generates an insignificant charge symmetry breaking nuclear force. C1 ARGONNE NATL LAB,DIV PHYS,ARGONNE,IL 60439. FLINDERS UNIV S AUSTRALIA,SCH PHYS SCI,BEDFORD PK,SA 5042,AUSTRALIA. RP MITCHELL, KL (reprint author), KENT STATE UNIV,DEPT PHYS,CTR NUCL RES,KENT,OH 44242, USA. NR 27 TC 52 Z9 52 U1 0 U2 3 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0370-2693 J9 PHYS LETT B JI Phys. Lett. B PD SEP 8 PY 1994 VL 335 IS 3-4 BP 282 EP 288 DI 10.1016/0370-2693(94)90351-4 PG 7 WC Astronomy & Astrophysics; Physics, Nuclear; Physics, Particles & Fields SC Astronomy & Astrophysics; Physics GA PF866 UT WOS:A1994PF86600006 ER PT J AU BRIGNOLE, A MURAYAMA, H RATTAZZI, R AF BRIGNOLE, A MURAYAMA, H RATTAZZI, R TI UPPER BOUND ON HOT DARK-MATTER DENSITY FROM SO(10) YUKAWA UNIFICATION SO PHYSICS LETTERS B LA English DT Article ID GRAND UNIFIED THEORIES; TOP-QUARK; WEAK; MASS; OSCILLATIONS; COUPLINGS; SU(5) AB We study low-energy consequences of supersymmetric SO(10) models with Yukawa unification h(t) = h(N) and h(b) = h(tau). We find that it is difficult to reproduce the observed m(b)/m(tau) ratio when the third-generation right-handed neutrino is at an intermediate scale, especially for small tan beta. We obtain a conservative lower bound on the mass of the right-handed neutrino M(N) > 6 x 10(13) GeV for tan beta < 10. This bound translates into an upper bound on the tau-neutrino mass, and therefore on its contribution to the hot dark matter density of the present universe, OMEGA(nu)h2 < 0.004. Our analysis is based on the full two-loop renormalization group equations with one-loop threshold effects. However, we also point out that physics above the GUT-scale could modify the Yukawa unification condition h(b) = h(tau) for tan beta less-than-or-similar-to 10. This might affect the prediction of m(b)/m(tau) and the constraint on M(N). C1 RUTGERS STATE UNIV,DEPT PHYS,PISCATAWAY,NJ 08855. RP BRIGNOLE, A (reprint author), LAWRENCE BERKELEY LAB,THEORET PHYS GRP,BERKELEY,CA 94720, USA. RI Murayama, Hitoshi/A-4286-2011; OI Rattazzi, Riccardo/0000-0003-0276-017X NR 42 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 SEP 8 PY 1994 VL 335 IS 3-4 BP 345 EP 354 DI 10.1016/0370-2693(94)90362-X PG 10 WC Astronomy & Astrophysics; Physics, Nuclear; Physics, Particles & Fields SC Astronomy & Astrophysics; Physics GA PF866 UT WOS:A1994PF86600017 ER PT J AU ADAMS, MR AID, S ANTHONY, PL BAKER, MD BARTLETT, J BHATTI, AA BOTTERWECK, F BRAUN, HM BUSZA, W CONRAD, JM COUTRAKON, G DAVISSON, R DERADO, I DHAWAN, SK DOUGHERTY, W DREYER, T DZIUNIKOWSKA, K ECKARDT, V ECKER, U ERDMANN, M ESKREYS, A FIGIEL, J GEBAUER, HJ GEESAMAN, DF GILMAN, R GREEN, MC HAAS, J HALLIWELL, C HANLON, J HANTKE, D HUGHES, VW JACKSON, HE JAFFE, DE JANCSO, G JANSEN, DM KADIJA, K KAUFMAN, S KENNEDY, RD KIRK, T KOBRAK, HGE KRZYWDZINSKI, S KUNORI, S LORD, JJ LUBATTI, HJ MCLEOD, D MAGILL, S MALECKI, P MANZ, A MELANSON, H MICHAEL, DG MOHR, W MONTGOMERY, HE MORFIN, JG NICKERSON, RB ODAY, S OLKIEWICZ, K OSBORNE, L PAPAVASSILIOU, V PAWLIK, B PIPKIN, FM RAMBERG, EJ ROSER, A RYAN, JJ SALGADO, CW SALVARANI, A SCHELLMAN, H SCHMITT, M SCHMITZ, N SCHULER, KP SEYERLEIN, HJ SKUJA, A SNOW, GA SOLDNERREMBOLD, S STEINBERG, PH STIER, HE STOPA, P SWANSON, RA TALAGA, R TENTINDOREPOND, S TROST, HJ VENKATARAMANIA, H WILHELM, M WILKES, J WILSON, R WITTEK, W WOLBERS, SA ZHAO, T AF ADAMS, MR AID, S ANTHONY, PL BAKER, MD BARTLETT, J BHATTI, AA BOTTERWECK, F BRAUN, HM BUSZA, W CONRAD, JM COUTRAKON, G DAVISSON, R DERADO, I DHAWAN, SK DOUGHERTY, W DREYER, T DZIUNIKOWSKA, K ECKARDT, V ECKER, U ERDMANN, M ESKREYS, A FIGIEL, J GEBAUER, HJ GEESAMAN, DF GILMAN, R GREEN, MC HAAS, J HALLIWELL, C HANLON, J HANTKE, D HUGHES, VW JACKSON, HE JAFFE, DE JANCSO, G JANSEN, DM KADIJA, K KAUFMAN, S KENNEDY, RD KIRK, T KOBRAK, HGE KRZYWDZINSKI, S KUNORI, S LORD, JJ LUBATTI, HJ MCLEOD, D MAGILL, S MALECKI, P MANZ, A MELANSON, H MICHAEL, DG MOHR, W MONTGOMERY, HE MORFIN, JG NICKERSON, RB ODAY, S OLKIEWICZ, K OSBORNE, L PAPAVASSILIOU, V PAWLIK, B PIPKIN, FM RAMBERG, EJ ROSER, A RYAN, JJ SALGADO, CW SALVARANI, A SCHELLMAN, H SCHMITT, M SCHMITZ, N SCHULER, KP SEYERLEIN, HJ SKUJA, A SNOW, GA SOLDNERREMBOLD, S STEINBERG, PH STIER, HE STOPA, P SWANSON, RA TALAGA, R TENTINDOREPOND, S TROST, HJ VENKATARAMANIA, H WILHELM, M WILKES, J WILSON, R WITTEK, W WOLBERS, SA ZHAO, T TI DENSITY AND CORRELATION INTEGRALS IN DEEP-INELASTIC MUON-NUCLEON SCATTERING AT 490 GEV SO PHYSICS LETTERS B LA English DT Article ID BOSE-EINSTEIN CORRELATIONS; HIGH-ENERGY; MULTIPARTICLE PRODUCTION; INTERMITTENCY; MOMENTS; COLLISIONS; FLUCTUATIONS; CUMULANTS AB Results on density integrals F(q)(Q2) and correlation integrals K(q)(Q2) are presented for the first time in muon-nucleon scattering at approximately 490 GeV, using data from the E665 experiment at the Tevatron of Fermilab. A clear rise of the F(q) integrals with decreasing size of the phase-space cells (''intermittency'') is observed for pairs and triplets of negative hadrons whereas the effect is much weaker for mixed charge combinations. From these findings it is concluded that the observed intermittency signal is mainly caused by Bose-Einstein interference. Furthermore, no energy (W) dependence of F2(Q2) is observed within the W range of the E665 experiment. Finally, the third-order correlation integrals K3(Q2) are found to be significantly different from zero which implies the presence of genuine three-particle correlations in muon-nucleon interactions. C1 ARGONNE NATL LAB,ARGONNE,IL 60439. UNIV CALIF SAN DIEGO,LA JOLLA,CA 92093. HARVARD UNIV,CAMBRIDGE,MA 02138. UNIV ILLINOIS,CHAMPAIGN,IL 61820. INST NUCL PHYS,PL-31342 KRAKOW,POLAND. STANISLAW STASZIC UNIV MIN & MET,INST NUCL PHYS,PL-30059 KRAKOW,POLAND. UNIV MARYLAND,COLLEGE PK,MD 20742. MIT,CAMBRIDGE,MA 02139. MAX PLANCK INST PHYS & ASTROPHYS,MUNICH,GERMANY. NORTHWESTERN UNIV,EVANSTON,IL 60201. UNIV WASHINGTON,SEATTLE,WA 98195. UNIV GESAMTHSCH WUPPERTAL,W-5600 WUPPERTAL 1,GERMANY. YALE UNIV,NEW HAVEN,CT 06520. RP ADAMS, MR (reprint author), UNIV FREIBURG,W-7800 FREIBURG,GERMANY. NR 25 TC 9 Z9 9 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 SEP 8 PY 1994 VL 335 IS 3-4 BP 535 EP 541 DI 10.1016/0370-2693(94)90390-5 PG 7 WC Astronomy & Astrophysics; Physics, Nuclear; Physics, Particles & Fields SC Astronomy & Astrophysics; Physics GA PF866 UT WOS:A1994PF86600045 ER PT J AU ACCIARRI, M ADAM, A ADRIANI, O AGUILARBENITEZ, M AHLEN, S ALCARAZ, J ALOISIO, A ALVERSON, G ALVIGGI, MG AMBROSI, G AN, Q ANDERHUB, H ANDERSON, AL ANDREEV, VP ANGELESCU, T ANTONOV, L ANTREASYAN, D ALKHAZOV, G ARCE, P AREFIEV, A AZEMOON, T AZIZ, T BABA, PVKS BAGNAIA, P BAKKEN, JA BAKSAY, L BALL, RC BANERJEE, S BANICZ, K BARILLERE, R BARONE, L BASCHIROTTO, A BASILE, M BATTISTON, R BAY, A BECATTINI, F BECKER, U BEHNER, F BENCZE, GL BERDUGO, J BERGES, P BERTUCCI, B BETEV, BL BIASINI, M BILAND, A BILEI, GM BIZZARRI, R BLAISING, JJ BOBBINK, GJ BOCK, R BOHM, A BORGIA, B BOURILKOV, D BOURQUIN, M BOUTIGNY, D BOUWENS, B BRAMBILLA, E BRANSON, JG BRIGLJEVIC, V BROCK, IC BROOKS, M BUJAK, A BURGER, JD BURGER, WJ BURGOS, C BUSENITZ, J BUYTENHUIJS, A BYKOV, A CAI, XD CAPELL, M ROMEO, GC CARIA, M CARLINO, G CARTACCI, AM CASAUS, J CASTELLO, R CAVALLO, N CERRADA, M CESARONI, F CHAMIZO, M CHANG, YH CHATURVEDI, UK CHEMARIN, M CHEN, A CHEN, C CHEN, G CHEN, GM CHEN, HF CHEN, HS CHEN, M CHIEFARI, G CHIEN, CY CHOI, MT CHUNG, S CIFARELLI, L CINDOLO, F CIVININI, C CLARE, I CLARE, R COAN, TE COHN, HO COIGNET, G COLINO, N COSTANTINI, S COTOROBAI, F DELACRUZ, B CUI, XT CUI, XY DAI, TS DALESSANDRO, R DEASMUNDIS, R DEGRE, A DEITERS, K DENES, E DENES, P DENOTARISTEFANI, F DIBITONTO, D DIEMOZ, M DIMITROV, HR DIONISI, C DITTMAR, M DJAMBAZOV, L DOVA, MT DRAGO, E DUCHESNEAU, D DUINKER, P DURAN, I EASO, S ELMAMOUNI, H ENGLER, A EPPLING, FJ ERNE, FC EXTERMANN, P FABBRETTI, R FABRE, M FALCIANO, S FAVARA, A FAY, J FELCINI, M FERGUSON, T FERNANDEZ, D FERNANDEZ, G FERRONI, F FESEFELDT, H FIANDRINI, E FIELD, JH FILTHAUT, F FISHER, PH FORCONI, G FREDJ, L FREUDENREICH, K GAILLOUD, M GALAKTIONOV, Y GALLO, E GANGULI, SN GARCIAABIA, P GENTILE, S GERALD, J GHEORDANESCU, N GIAGU, S GOLDFARB, S GONG, ZF GONZALEZ, E GOUGAS, A GOUJON, D GRATTA, G GRUENEWALD, MW GU, C GUANZIROLI, M GUPTA, VK GURTU, A GUSTAFSON, HR GUTAY, LJ HASAN, A HAUSCHILDT, D HE, JT HEBBEKER, T HEBERT, M HERVE, A HILGERS, K HOFER, H HOORANI, H HOU, SR HU, G ILLE, B ILYAS, MM INNOCENTE, V JANSSEN, H JIN, BN JONES, LW DEJONG, P JOSAMUTUBERRIA, I KASSER, A KHAN, RA KAMYSHKOV, Y KAPINOS, P KAPUSTINSKY, JS KARYOTAKIS, Y KAUR, M KHOKHAR, S KIENZLEFOCACCI, MN KIM, D KIM, JK KIM, SC KIM, YG KINNISON, WW KIRKBY, A KIRKBY, D KIRSCH, S KITTEL, W KLIMENTOV, A KONIG, AC KOFFEMAN, E KORNADT, O KOUTSENKO, V KOULBARDIS, A KRAEMER, RW KRAMER, T KRASTEV, VR KRENZ, W KUIJTEN, H KUMAR, KS KUNIN, A DEGUEVARA, PL LANDI, G LANSKE, D LANZANO, S LEBEDEV, A LEBRUN, P LECOMTE, P LECOQ, P LECOULTRE, P LEE, DM LEE, JS LEE, KY LEEDOM, I LEGGETT, C LEGOFF, JM LEISTE, R LENTI, M LEONARDI, E LEVTCHENKO, P LI, C LIN, WT LINDE, FL LINDEMANN, B LISTA, L LIU, Y LOHMANN, W LONGO, E LU, W LU, YS LUBBERS, JM LUBELSMEYER, K LUCI, C LUCKEY, D LUDOVICI, L LUMINARI, L LUSTERMANN, W MA, WG MACDERMOTT, M MALGERI, L MALIK, R MALININ, A MANA, C MAOLINBAY, M MARCHESINI, P MARION, F MARIN, A MARTIN, JP MARZANO, F MASSARO, GGG MAZUMDAR, K MCBRIDE, P MCMAHON, T MCNALLY, D MERK, M MEROLA, L MESCHINI, M METZGER, WJ MI, Y MIHUL, A MILLS, GB MIR, Y MIRABELLI, G MNICH, J MOLLER, M MONACO, V MONTELEONI, B MORAND, R MORGANTI, S MOULAI, NE MOUNT, R MULLER, S NAGY, E NAPOLITANO, M NESSITEDALDI, F NEWMAN, H NIAZ, MA NIPPE, A NOWAK, H ORGANTINI, G PANDOULAS, D PAOLETTI, S PAOLUCCI, P PASCALE, G PASSALEVA, G PATRICELLI, S PAUL, T PAULUZZI, M PAUS, C PAUSS, F PEI, YJ PENSOTTI, S PERRETGALLIX, D PEVSNER, A PICCOLO, D PIERI, M PINTO, JC PIROUE, PA PLASIL, F PLYASKIN, V POHL, M POJIDAEV, V POSTEMA, H PRODUIT, N QIAN, JM QURESHI, KN RAGHAVAN, R RAHALCALLOT, G RANCOITA, PG RATTAGGI, M RAVEN, G RAZIS, P READ, K REDAELLI, M REN, D REN, Z RESCIGNO, M REUCROFT, S RICKER, A RIEMANN, S RIEMERS, BC RILES, K RIND, O RIZVI, HA RO, S ROBOHM, A RODRIGUEZ, FJ ROE, BP ROHNER, M ROHNER, S ROMERO, L ROSIERLEES, S ROSMALEN, R ROSSELET, P VANROSSUM, W ROTH, S RUBBIA, A RUBIO, JA RYKACZEWSKI, H SACHWITZ, M SALICIO, J SALICIO, JM SANCHEZ, E SANDERS, GS SANTOCCHIA, A SARAKINOS, ME SARTORELLI, G SASSOWSKY, M SAUVAGE, G SCHAFER, C SCHEGELSKY, V SCHMITZ, D SCHMITZ, P SCHNEEGANS, M SCHOLZ, N SCHOPPER, H SCHOTANUS, DJ SHOTKIN, S SCHREIBER, HJ SHUKLA, J SCHULTE, R SCHULTZE, K SCHWENKE, J SCHWERING, G SCIACCA, C SCOTT, I SEHGAL, R SEILER, PG SENS, JC SERVOLI, L SHEER, I SHEVCHENKO, S SHI, XR SHUMILOV, E SHOUTKO, V SON, D SOPCZAK, A SOULIMOV, V SPARTIOTIS, C SPICKERMANN, T SPILLANTINI, P STEUER, M STICKLAND, DP STICOZZI, F STONE, H STRAUCH, K SUDHAKAR, K SULTANOV, G SUN, LZ SUSINNO, GF SUTER, H SWAIN, JD SYED, AA TANG, XW TAYLOR, L TIMELLINI, R TING, SCC TING, SM TOKER, O TONUTTI, M TONWAR, SC TOTH, J TROWITZSCH, G TSAREGORODTSEV, A TSIPOLITIS, G TULLY, C TUUVA, T ULBRICHT, J URBAN, L UWER, U VALENTE, E VANDEWALLE, RT VETLITSKY, I VIERTEL, G VIKAS, P VIKAS, U VIVARGENT, M VOGEL, H VOGT, H VOROBIEV, I VOROBYOV, AA VOROBYOV, AA VUILLEUMIER, L WADHWA, M WALLRAFF, W WANG, JC WANG, XL WANG, YF WANG, ZM WEBER, A WEBER, J WEILL, R WILLMOTT, C WITTGENSTEIN, F WRIGHT, D WU, SX WYNHOFF, S XU, ZZ YANG, BZ YANG, CG YANG, G YAO, XY YE, CH YE, JB YE, Q YEH, SC YOU, JM YUNUS, N YZERMAN, M ZACCARDELLI, C ZEMP, P ZENG, M ZENG, Y ZHANG, DH ZHANG, ZP ZHOU, B ZHOU, GJ ZHOU, JF ZHU, RY ZICHICHI, A VANDERZWAAN, BCC AF ACCIARRI, M ADAM, A ADRIANI, O AGUILARBENITEZ, M AHLEN, S ALCARAZ, J ALOISIO, A ALVERSON, G ALVIGGI, MG AMBROSI, G AN, Q ANDERHUB, H ANDERSON, AL ANDREEV, VP ANGELESCU, T ANTONOV, L ANTREASYAN, D ALKHAZOV, G ARCE, P AREFIEV, A AZEMOON, T AZIZ, T BABA, PVKS BAGNAIA, P BAKKEN, JA BAKSAY, L BALL, RC BANERJEE, S BANICZ, K BARILLERE, R BARONE, L BASCHIROTTO, A BASILE, M BATTISTON, R BAY, A BECATTINI, F BECKER, U BEHNER, F BENCZE, GL BERDUGO, J BERGES, P BERTUCCI, B BETEV, BL BIASINI, M BILAND, A BILEI, GM BIZZARRI, R BLAISING, JJ BOBBINK, GJ BOCK, R BOHM, A BORGIA, B BOURILKOV, D BOURQUIN, M BOUTIGNY, D BOUWENS, B BRAMBILLA, E BRANSON, JG BRIGLJEVIC, V BROCK, IC BROOKS, M BUJAK, A BURGER, JD BURGER, WJ BURGOS, C BUSENITZ, J BUYTENHUIJS, A BYKOV, A CAI, XD CAPELL, M ROMEO, GC CARIA, M CARLINO, G CARTACCI, AM CASAUS, J CASTELLO, R CAVALLO, N CERRADA, M CESARONI, F CHAMIZO, M CHANG, YH CHATURVEDI, UK CHEMARIN, M CHEN, A CHEN, C CHEN, G CHEN, GM CHEN, HF CHEN, HS CHEN, M CHIEFARI, G CHIEN, CY CHOI, MT CHUNG, S CIFARELLI, L CINDOLO, F CIVININI, C CLARE, I CLARE, R COAN, TE COHN, HO COIGNET, G COLINO, N COSTANTINI, S COTOROBAI, F DELACRUZ, B CUI, XT CUI, XY DAI, TS DALESSANDRO, R DEASMUNDIS, R DEGRE, A DEITERS, K DENES, E DENES, P DENOTARISTEFANI, F DIBITONTO, D DIEMOZ, M DIMITROV, HR DIONISI, C DITTMAR, M DJAMBAZOV, L DOVA, MT DRAGO, E DUCHESNEAU, D DUINKER, P DURAN, I EASO, S ELMAMOUNI, H ENGLER, A EPPLING, FJ ERNE, FC EXTERMANN, P FABBRETTI, R FABRE, M FALCIANO, S FAVARA, A FAY, J FELCINI, M FERGUSON, T FERNANDEZ, D FERNANDEZ, G FERRONI, F FESEFELDT, H FIANDRINI, E FIELD, JH FILTHAUT, F FISHER, PH FORCONI, G FREDJ, L FREUDENREICH, K GAILLOUD, M GALAKTIONOV, Y GALLO, E GANGULI, SN GARCIAABIA, P GENTILE, S GERALD, J GHEORDANESCU, N GIAGU, S GOLDFARB, S GONG, ZF GONZALEZ, E GOUGAS, A GOUJON, D GRATTA, G GRUENEWALD, MW GU, C GUANZIROLI, M GUPTA, VK GURTU, A GUSTAFSON, HR GUTAY, LJ HASAN, A HAUSCHILDT, D HE, JT HEBBEKER, T HEBERT, M HERVE, A HILGERS, K HOFER, H HOORANI, H HOU, SR HU, G ILLE, B ILYAS, MM INNOCENTE, V JANSSEN, H JIN, BN JONES, LW DEJONG, P JOSAMUTUBERRIA, I KASSER, A KHAN, RA KAMYSHKOV, Y KAPINOS, P KAPUSTINSKY, JS KARYOTAKIS, Y KAUR, M KHOKHAR, S KIENZLEFOCACCI, MN KIM, D KIM, JK KIM, SC KIM, YG KINNISON, WW KIRKBY, A KIRKBY, D KIRSCH, S KITTEL, W KLIMENTOV, A KONIG, AC KOFFEMAN, E KORNADT, O KOUTSENKO, V KOULBARDIS, A KRAEMER, RW KRAMER, T KRASTEV, VR KRENZ, W KUIJTEN, H KUMAR, KS KUNIN, A DEGUEVARA, PL LANDI, G LANSKE, D LANZANO, S LEBEDEV, A LEBRUN, P LECOMTE, P LECOQ, P LECOULTRE, P LEE, DM LEE, JS LEE, KY LEEDOM, I LEGGETT, C LEGOFF, JM LEISTE, R LENTI, M LEONARDI, E LEVTCHENKO, P LI, C LIN, WT LINDE, FL LINDEMANN, B LISTA, L LIU, Y LOHMANN, W LONGO, E LU, W LU, YS LUBBERS, JM LUBELSMEYER, K LUCI, C LUCKEY, D LUDOVICI, L LUMINARI, L LUSTERMANN, W MA, WG MACDERMOTT, M MALGERI, L MALIK, R MALININ, A MANA, C MAOLINBAY, M MARCHESINI, P MARION, F MARIN, A MARTIN, JP MARZANO, F MASSARO, GGG MAZUMDAR, K MCBRIDE, P MCMAHON, T MCNALLY, D MERK, M MEROLA, L MESCHINI, M METZGER, WJ MI, Y MIHUL, A MILLS, GB MIR, Y MIRABELLI, G MNICH, J MOLLER, M MONACO, V MONTELEONI, B MORAND, R MORGANTI, S MOULAI, NE MOUNT, R MULLER, S NAGY, E NAPOLITANO, M NESSITEDALDI, F NEWMAN, H NIAZ, MA NIPPE, A NOWAK, H ORGANTINI, G PANDOULAS, D PAOLETTI, S PAOLUCCI, P PASCALE, G PASSALEVA, G PATRICELLI, S PAUL, T PAULUZZI, M PAUS, C PAUSS, F PEI, YJ PENSOTTI, S PERRETGALLIX, D PEVSNER, A PICCOLO, D PIERI, M PINTO, JC PIROUE, PA PLASIL, F PLYASKIN, V POHL, M POJIDAEV, V POSTEMA, H PRODUIT, N QIAN, JM QURESHI, KN RAGHAVAN, R RAHALCALLOT, G RANCOITA, PG RATTAGGI, M RAVEN, G RAZIS, P READ, K REDAELLI, M REN, D REN, Z RESCIGNO, M REUCROFT, S RICKER, A RIEMANN, S RIEMERS, BC RILES, K RIND, O RIZVI, HA RO, S ROBOHM, A RODRIGUEZ, FJ ROE, BP ROHNER, M ROHNER, S ROMERO, L ROSIERLEES, S ROSMALEN, R ROSSELET, P VANROSSUM, W ROTH, S RUBBIA, A RUBIO, JA RYKACZEWSKI, H SACHWITZ, M SALICIO, J SALICIO, JM SANCHEZ, E SANDERS, GS SANTOCCHIA, A SARAKINOS, ME SARTORELLI, G SASSOWSKY, M SAUVAGE, G SCHAFER, C SCHEGELSKY, V SCHMITZ, D SCHMITZ, P SCHNEEGANS, M SCHOLZ, N SCHOPPER, H SCHOTANUS, DJ SHOTKIN, S SCHREIBER, HJ SHUKLA, J SCHULTE, R SCHULTZE, K SCHWENKE, J SCHWERING, G SCIACCA, C SCOTT, I SEHGAL, R SEILER, PG SENS, JC SERVOLI, L SHEER, I SHEVCHENKO, S SHI, XR SHUMILOV, E SHOUTKO, V SON, D SOPCZAK, A SOULIMOV, V SPARTIOTIS, C SPICKERMANN, T SPILLANTINI, P STEUER, M STICKLAND, DP STICOZZI, F STONE, H STRAUCH, K SUDHAKAR, K SULTANOV, G SUN, LZ SUSINNO, GF SUTER, H SWAIN, JD SYED, AA TANG, XW TAYLOR, L TIMELLINI, R TING, SCC TING, SM TOKER, O TONUTTI, M TONWAR, SC TOTH, J TROWITZSCH, G TSAREGORODTSEV, A TSIPOLITIS, G TULLY, C TUUVA, T ULBRICHT, J URBAN, L UWER, U VALENTE, E VANDEWALLE, RT VETLITSKY, I VIERTEL, G VIKAS, P VIKAS, U VIVARGENT, M VOGEL, H VOGT, H VOROBIEV, I VOROBYOV, AA VOROBYOV, AA VUILLEUMIER, L WADHWA, M WALLRAFF, W WANG, JC WANG, XL WANG, YF WANG, ZM WEBER, A WEBER, J WEILL, R WILLMOTT, C WITTGENSTEIN, F WRIGHT, D WU, SX WYNHOFF, S XU, ZZ YANG, BZ YANG, CG YANG, G YAO, XY YE, CH YE, JB YE, Q YEH, SC YOU, JM YUNUS, N YZERMAN, M ZACCARDELLI, C ZEMP, P ZENG, M ZENG, Y ZHANG, DH ZHANG, ZP ZHOU, B ZHOU, GJ ZHOU, JF ZHU, RY ZICHICHI, A VANDERZWAAN, BCC TI MEASUREMENT OF THE B(0)-(B)OVER-BAR(0) MIXING PARAMETER AND THE Z-]B(B)OVER-BAR FORWARD-BACKWARD ASYMMETRY SO PHYSICS LETTERS B LA English DT Article ID SEMILEPTONIC BRANCHING RATIOS; FERMION PAIR PRODUCTION; HADRONIC Z(0) DECAYS; LUND MONTE-CARLO; Z0 DECAYS; JET FRAGMENTATION; E+E ANNIHILATION; QED CORRECTIONS; PHYSICS; MESONS AB We have measured the time integrated B0-BBAR0 mixing parameter and the forward-backward asymmetry in the process e+e- --> bbBAR using hadronic events containing muons or electrons. The data sample corresponds to 1,044,000 hadronic decays of the Z. From a fit to the momentum and transverse momentum distributions for single lepton and dilepton events, we have determined the B0-BBAR0 mixing parameter to be chi(B) = 0.123 +/- 0.012 (stat.) +/- 0.008 (sys.), and the bbBAR forward-backward asymmetry at the effective center-of-mass energy square-root s = 91.30 GeV to be A(bbBAR) = 0.087 +/- 0.011 (stat.) +/- 0.004 (sys.) This measurement corresponds to a value of the effective electroweak mixing angle of sin2thetaBAR(w) = 0.2335 +/- 0.0021. C1 UNIV MICHIGAN, ANN ARBOR, MI 48109 USA. JOHNS HOPKINS UNIV, BALTIMORE, MD 21218 USA. TATA INST FUNDAMENTAL RES, BOMBAY 400005, INDIA. BOSTON UNIV, BOSTON, MA 02215 USA. NORTHEASTERN UNIV, BOSTON, MA 02115 USA. UNIV BUCHAREST, R-76900 BUCHAREST, ROMANIA. HARVARD UNIV, CAMBRIDGE, MA 02138 USA. MIT, CAMBRIDGE, MA 02139 USA. UNIV FLORENCE, I-50121 FLORENCE, ITALY. UNIV LAUSANNE, CH-1015 LAUSANNE, SWITZERLAND. LOS ALAMOS NATL LAB, LOS ALAMOS, NM 87544 USA. UNIV NAPLES, I-80125 NAPLES, ITALY. CATHOLIC UNIV NIJMEGEN, 6525 ED NIJMEGEN, NETHERLANDS. OAK RIDGE NATL LAB, OAK RIDGE, TN 37831 USA. CALTECH, PASADENA, CA 91125 USA. UNIV PERUGIA, I-06100 PERUGIA, ITALY. CARNEGIE MELLON UNIV, PITTSBURGH, PA 15213 USA. PRINCETON UNIV, PRINCETON, NJ 08544 USA. UNIV ROMA LA SAPIENZA, I-00185 ROME, ITALY. ST PETERSBURG NUCL PHYS INST, ST PETERSBURG, RUSSIA. HUNGARIAN ACAD SCI, CENT RES INST PHYS, H-1525 BUDAPEST 114, HUNGARY. FBLJA PROJECT, WORLD LAB, CH-1211 GENEVA 23, SWITZERLAND. UNIV LYON 1, IN2P3, CNRS, INST PHYS NUCL LYON, F-69622 VILLEURBANNE, FRANCE. RHEIN WESTFAL TH AACHEN, INST PHYS 1, D-52056 AACHEN, GERMANY. RHEIN WESTFAL TH AACHEN, INST PHYS 3, D-52056 AACHEN, GERMANY. NIKHEF, NATL INST HIGH ENERGY PHYS, 1009 DB AMSTERDAM, NETHERLANDS. IN2P3, CNRS, LAB ANNECY VIEUX PHYS PARTICULES, F-74941 ANNECY LE VIEUX, FRANCE. INST HIGH ENERGY PHYS, 100039 BEIJING, PEOPLES R CHINA. HUMBOLDT UNIV BERLIN, D-10099 BERLIN, GERMANY. INFN, I-40126 BOLOGNA, ITALY. INST ATOM PHYS, R-76900 BUCHAREST, ROMANIA. INFN, I-50125 FLORENCE, ITALY. CERN, EUROPEAN LAB PARTICLE PHYS, CH-1211 GENEVA 23, SWITZERLAND. CHINESE UNIV SCI & TECHNOL, HEFEI 230029, PEOPLES R CHINA. SEFT, HIGH ENERGY PHYS RES INST, SF-00014 HELSINKI, FINLAND. CIEMAT, CTR INVEST ENERGET MEDIOAMBIENTALES & TECNOL, E-28040 MADRID, SPAIN. INFN, I-20133 MILAN, ITALY. INST THEORET & EXPTL PHYS, MOSCOW, RUSSIA. INFN, I-80125 NAPLES, ITALY. UNIV CYPRUS, DEPT NAT SCI, NICOSIA, CYPRUS. NATL INST NUCL PHYS & HIGH ENERGY PHYS, 6525 ED NIJMEGEN, NETHERLANDS. INFN, PERUGIA, ITALY. INFN, ROME, ITALY. UNIV CALIF SAN DIEGO, LA JOLLA, CA 92093 USA. BULGARIAN ACAD SCI, INST MECHATRON, BU-1113 SOFIA, BULGARIA. UNIV SANTIAGO, DEPT FIS PARTICULAS ELEMENTALES, E-15706 SANTIAGO, SPAIN. KOREA ADV INST SCI & TECHNOL, CTR HIGH ENERGY PHYS, TAEJON 305701, SOUTH KOREA. PAUL SCHERRER INST, CH-5232 VILLIGEN, SWITZERLAND. UNIV ALABAMA, UNIVERSITY, AL 35486 USA. DESY, INST HOCHENERGIEPHYS, D-15738 ZEUTHEN, GERMANY. PURDUE UNIV, W LAFAYETTE, IN 47907 USA. SWISS FED INST TECHNOL, CH-8093 ZURICH, SWITZERLAND. UNIV HAMBURG, D-22761 HAMBURG, GERMANY. RP INFN, I-20133 MILAN, ITALY. RI van der Zwaan, Bob/F-4070-2015; D'Alessandro, Raffaello/F-5897-2015; Duran, Ignacio/H-7254-2015; rodriguez calonge, francisco javier/H-9682-2015; Sanchez, Eusebio/H-5228-2015; Rancoita, Pier Giorgio/J-9896-2015; Hoorani, Hafeez/D-1791-2013; Arce, Pedro/L-1268-2014; Roth, Stefan/J-2757-2016; Ludovici, Lucio/F-5917-2011; Servoli, Leonello/E-6766-2012; bertucci, bruna/J-5237-2012; Cavallo, Nicola/F-8913-2012; Cerrada, Marcos/J-6934-2014; de la Cruz, Begona/K-7552-2014; Josa, Isabel/K-5184-2014; Gonzalez Romero, Enrique/L-7561-2014; Fiandrini, Emanuele/C-4549-2008; Lista, Luca/C-5719-2008; Vogel, Helmut/N-8882-2014; Ferguson, Thomas/O-3444-2014; Berdugo, Javier/A-2858-2015 OI van der Zwaan, Bob/0000-0001-5871-7643; D'Alessandro, Raffaello/0000-0001-7997-0306; Sanchez, Eusebio/0000-0002-9646-8198; Rancoita, Pier Giorgio/0000-0002-1990-4283; Arce, Pedro/0000-0003-3009-0484; Roth, Stefan/0000-0003-3616-2223; 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 NR 44 TC 21 Z9 21 U1 2 U2 5 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0370-2693 EI 1873-2445 J9 PHYS LETT B JI Phys. Lett. B PD SEP 8 PY 1994 VL 335 IS 3-4 BP 542 EP 553 DI 10.1016/0370-2693(94)90391-3 PG 12 WC Astronomy & Astrophysics; Physics, Nuclear; Physics, Particles & Fields SC Astronomy & Astrophysics; Physics GA PF866 UT WOS:A1994PF86600046 ER PT J AU KELLER, SW CARLSON, VA SANDFORD, D STENZEL, F STACY, AM KWEI, GH ALARIOFRANCO, M AF KELLER, SW CARLSON, VA SANDFORD, D STENZEL, F STACY, AM KWEI, GH ALARIOFRANCO, M TI A NEW SERIES OF MAGNETIC RARE-EARTH CUPRATES - RCU(2)O(4) (R=LA, ND, SM, AND EU) SO JOURNAL OF THE AMERICAN CHEMICAL SOCIETY LA English DT Article ID HIGH-TEMPERATURE SUPERCONDUCTIVITY; O SYSTEM; PHASE; ANTIFERROMAGNETISM; BAPB1-XBIXO3; COMPOUND; LA2CUO4; OXIDES; LA AB The synthesis, crystal structure, and magnetic properties of a new series of isostructural rare earth cuprates, RCu(2)O(4) (R = La, Nd, Sm, and Eu), are reported. The highly oxidized materials with an average formal copper oxidation state of Cu-2.5+ were isolated by precipitation from molten NaOH at 400 OC. Powder X-ray diffraction data for EuCu2O4 combined with neutron diffraction data for NdCu2O4 were used to determine the crystal structure and refine the structure by Rietveld profile analysis. The lattice parameters for NdCu2O4 in the non-standard monoclinic space group 12/a derived from the neutron data set are the following: a 5.826(1) Angstrom, b = 9.703(1) Angstrom, c - 5.753(1) Angstrom, and beta = 92.341(1)degrees. The copper-oxygen network consists of a three-dimensional array of CuO4 distorted square planes that are cornered-shared; the Cu-O-Cu bond angle is similar to 115 degrees. These phases exhibit magnetic ordering of the copper spins as determined by a large increase in the magnetization as the temperature is lowered, the onset of which varies between 18 and 28 K, depending on R. While the negative Weiss constants for LaCu2O4 and NdCu2O4 indicate that the predominant interaction is antiferromagnetic, the saturation moments of similar to 0.13 mu(B) per mol of RCu(2)O(4) indicate that there is a significant ferromagnetic component, possibly due to canting of the ordered copper moments. C1 UNIV CALIF BERKELEY,DEPT CHEM,BERKELEY,CA 94720. LOS ALAMOS NATL LAB,LOS ALAMOS,NM 87545. UNIV COMPLUTENSE MADRID,FAC CIENCIAS QUIM,E-28040 MADRID,SPAIN. NR 38 TC 52 Z9 52 U1 3 U2 8 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 SN 0002-7863 J9 J AM CHEM SOC JI J. Am. Chem. Soc. PD SEP 7 PY 1994 VL 116 IS 18 BP 8070 EP 8076 DI 10.1021/ja00097a013 PG 7 WC Chemistry, Multidisciplinary SC Chemistry GA PF913 UT WOS:A1994PF91300013 ER PT J AU YANG, H CAVES, TC WHITTEN, JL HUNTLEY, DR AF YANG, H CAVES, TC WHITTEN, JL HUNTLEY, DR TI CHEMISORPTION STUDIES OF CH3S ON NI(111) SO JOURNAL OF THE AMERICAN CHEMICAL SOCIETY LA English DT Article ID METALLIC SURFACES; PT(111) SURFACE; NI(111); ADSORPTION; METHANETHIOL; HYDROGEN; DECOMPOSITION; THIOLATE; MO(110); NICKEL AB The chemisorption of methanethiolate on Ni(111) is treated using a many-electron embedding theory, modeling the lattice as a 28-atom, three-layer cluster with the Ni atoms fixed at the positions from the bulk. Methanethiolate binds strongly to the Ni(111) surface at both high and low symmetry sites. Calculated adsorption energies are 61 kcal/mol for an equilibrium sulfur-surface distance of 1.99 Angstrom at three-fold sites, 61 kcal/mol with a sulfur-surface distance of 2.06 Angstrom at bridge sites, and 57 kcal/mol with a sulfur-surface distance of 2.13 Angstrom at atop sites. Different equilibrium geometries are predicted for CH3S at three-fold, bridge, and atop sites. The methanethiolate C-S axis is nearly perpendicular to the surface, inclined only about 5 degrees from the surface normal, at the three-fold site. The C-S axis is found to be tilted away from the surface normal by 45 degrees at the bridge site, and by 55 degrees at the atop site. For the C-S axis perpendicular to the surface, the calculated C-S stretching vibration is 730 cm(-1), and the CH3S-surface stretch is 281 cm(-1) at the three-fold site. For a 45 degrees tilt at the bridge site and a 55 degrees tilt at the atop site, the CS stretching vibrations are 677 and 698 cm(-1), respectively. C1 OAK RIDGE NATL LAB, OAK RIDGE, TN 37831 USA. RP YANG, H (reprint author), N CAROLINA STATE UNIV, DEPT CHEM, RALEIGH, NC 27695 USA. NR 64 TC 25 Z9 25 U1 0 U2 1 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 SEP 7 PY 1994 VL 116 IS 18 BP 8200 EP 8206 DI 10.1021/ja00097a029 PG 7 WC Chemistry, Multidisciplinary SC Chemistry GA PF913 UT WOS:A1994PF91300029 ER PT J AU MOREIRA, I SUN, J CHO, MOK WISHART, JF ISIED, SS AF MOREIRA, I SUN, J CHO, MOK WISHART, JF ISIED, SS TI ELECTRON-TRANSFER FROM THE HEME OF CYTOCHROME-C TO 2 EQUIDISTANT REDOX-MODIFIED SITES, HISTIDINE-33 AND METHIONINE-65 - THE IMPORTANCE OF ELECTRONIC EFFECTS AND PEPTIDE NETWORKS SO JOURNAL OF THE AMERICAN CHEMICAL SOCIETY LA English DT Note ID TUNNELING PATHWAYS; COMPLEXES; PROTEINS; RATES; RUTHENIUM(II) C1 RUTGERS STATE UNIV,DEPT CHEM,NEW BRUNSWICK,NJ 08903. BROOKHAVEN NATL LAB,DEPT CHEM,UPTON,NY 11973. RI Wishart, James/L-6303-2013 OI Wishart, James/0000-0002-0488-7636 NR 34 TC 26 Z9 26 U1 0 U2 2 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 SN 0002-7863 J9 J AM CHEM SOC JI J. Am. Chem. Soc. PD SEP 7 PY 1994 VL 116 IS 18 BP 8396 EP 8397 DI 10.1021/ja00097a069 PG 2 WC Chemistry, Multidisciplinary SC Chemistry GA PF913 UT WOS:A1994PF91300069 ER PT J AU FISHMAN, MA PERELSON, AS AF FISHMAN, MA PERELSON, AS TI TH1/TH2 CROSS-REGULATION SO JOURNAL OF THEORETICAL BIOLOGY LA English DT Article ID CD4+ T-CELLS; DELAYED-TYPE HYPERSENSITIVITY; INTERFERON-GAMMA PRODUCTION; ANTIGEN-PRESENTING CELLS; LYMPH DENDRITIC CELLS; MEDIATED-IMMUNITY; CYTOKINE PRODUCTION; LEISHMANIA-MAJOR; INTERLEUKIN-4 SUPPRESSES; MACROPHAGE ACTIVATION AB We present and analyze a model for the cross-regulation of the Th1 and Th2 helper cell subsets during an immune response by the regulatory cytokines interferon-gamma (IFN-gamma) and interleukin-10 (IL-10). IFN-gamma, secreted by Th1 cells, can inhibit the proliferation of Th2 cells. Interleukin-10, secreted by Th2 cells, inhibits cytokine production by Th1 cells. Based on these properties, the model shows that responses are expected to be dominated by either Th1 cells or Th2 cells but not both. Which type dominates is shown to depend principally on the relative efficiencies of activation of the responding Th1 and Th2 cells. However, our model, as well as numerous experiments, show that perturbations of the system, allow one to switch from a Th2 to a Th1 response, or vice versa. Our model can account for observed outcomes of parasitic infection and may also contribute to our understanding of immune responses to HIV infection as well as to tolerance to self components. It also predicts that in certain parameter ranges vaccination with low doses of live parasites can provide protection against subsequent encounters with high doses that normally induce disease. Experiments by Bretscher et al. (1992, Science 257, 539) on Leishmania major infection are consistent with this prediction. A similar strategy may also be relevant for the design of an AIDS vaccine. Lastly, our results indicate that Th1/Th2 cross-regulation is capable of generating a ''sneaking through'' phenomenon, and hence it may play a role in tumor immunity. C1 LOS ALAMOS NATL LAB,DIV THEORET,LOS ALAMOS,NM 87545. WEIZMANN INST SCI,DEPT APPL MATH & COMP SCI,IL-76100 REHOVOT,ISRAEL. FU NIAID NIH HHS [AI28433] NR 87 TC 62 Z9 62 U1 0 U2 4 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 SEP 7 PY 1994 VL 170 IS 1 BP 25 EP 56 DI 10.1006/jtbi.1994.1166 PG 32 WC Biology; Mathematical & Computational Biology SC Life Sciences & Biomedicine - Other Topics; Mathematical & Computational Biology GA PK511 UT WOS:A1994PK51100003 PM 7967633 ER PT J AU DELOACH, LD PAYNE, SA CHAI, BHT LOUTTS, G AF DELOACH, LD PAYNE, SA CHAI, BHT LOUTTS, G TI LASER DEMONSTRATION OF NEODYMIUM-DOPED STRONTIUM CHLOROVANADATE SO APPLIED PHYSICS LETTERS LA English DT Article ID EFFICIENT AB Nd:Sr5(VO4)3Cl has been successfully lased using a Ti:sapphire pump laser operating at 810 nm. A slope efficiency of 52% for the 1.065 mum laser line and a lasing threshold of only a few tens of milliwatts have been measured. These favorable results are comparable to another Nd-doped vanadate apatite, Sr5(VO4)3F. A brief survey of the spectroscopy of Nd3+ in Sr5(VO4)3Cl, Sr5(VO4)3F, and Ca5(VO4)3F reveals properties which suggest the vanadate-based apatite crystals as a whole may represent a useful new class of Nd-laser hosts. C1 UNIV CENT FLORIDA,CTR RES ELECTROOPT & LASERS,ORLANDO,FL 32826. RP DELOACH, LD (reprint author), LAWRENCE LIVERMORE NATL LAB,POB 5508,LIVERMORE,CA 94550, USA. NR 17 TC 14 Z9 14 U1 1 U2 4 PU AMER INST PHYSICS PI WOODBURY PA CIRCULATION FULFILLMENT DIV, 500 SUNNYSIDE BLVD, WOODBURY, NY 11797-2999 SN 0003-6951 J9 APPL PHYS LETT JI Appl. Phys. Lett. PD SEP 5 PY 1994 VL 65 IS 10 BP 1208 EP 1210 DI 10.1063/1.112072 PG 3 WC Physics, Applied SC Physics GA PE880 UT WOS:A1994PE88000002 ER PT J AU VANDOREN, E VANCAMP, PE STRAUB, G AF VANDOREN, E VANCAMP, PE STRAUB, G TI SELF-CONSISTENT 2ND-ORDER SCREENING IN MANY-BODY THEORY SO INTERNATIONAL JOURNAL OF QUANTUM CHEMISTRY LA English DT Article AB Self-consistent screening arises in all many-body problems where one-particle equations containing functionals of the solutions are considered. In the theory of simple metals, e.g., these one-particle equations are usually solved to second-order perturbation in the crystal pseudopotential and to first order in the screening. However, higher-order screening terms have a sizable effect on the form factors, the electron charge density, and the screened pseudopotential. The effects of second order are presented for the bcc simple metals Na and Ba. A nonlocal exchange-correlation potential has been used since local density approximations such as rho1/3 cause difficulties in the electron-electron dielectric function. (C) 1994 John Wiley & Sons, Inc. C1 LOS ALAMOS NATL LAB, DIV THEORET, LOS ALAMOS, NM 87545 USA. RP ANTWERP STATE UNIV CTR, DEPT PHYS, GROENENBORGERLAAN 171, B-2020 ANTWERP, BELGIUM. NR 8 TC 0 Z9 0 U1 0 U2 0 PU WILEY-BLACKWELL PI HOBOKEN PA 111 RIVER ST, HOBOKEN 07030-5774, NJ USA SN 0020-7608 EI 1097-461X J9 INT J QUANTUM CHEM JI Int. J. Quantum Chem. PD SEP 5 PY 1994 VL 51 IS 6 BP 389 EP 396 PG 8 WC Chemistry, Physical; Mathematics, Interdisciplinary Applications; Physics, Atomic, Molecular & Chemical SC Chemistry; Mathematics; Physics GA PD549 UT WOS:A1994PD54900005 ER PT J AU BEARDEN, IG JANSSENS, RVF CARPENTER, MP MOORE, EF AHMAD, I DALY, PJ MAYER, R DRIGERT, MW FERNANDEZ, PB FORNAL, B GARG, U GRABOWSKI, ZW KHOO, TL LAURITSEN, T REVIOL, W YE, D AF BEARDEN, IG JANSSENS, RVF CARPENTER, MP MOORE, EF AHMAD, I DALY, PJ MAYER, R DRIGERT, MW FERNANDEZ, PB FORNAL, B GARG, U GRABOWSKI, ZW KHOO, TL LAURITSEN, T REVIOL, W YE, D TI DETAILED BAND STRUCTURES IN HG-189 AND HG-190 SO NUCLEAR PHYSICS A LA English DT Article DE GD-160 (S-34,4 AND 5N); E=159 MEV, 162 MEV 165 MEV; MEASURED E-GAMMA, I-GAMMA, GAMMA-GAMMA (THETA); GAMMA-GAMMA-CORRELATIONS; 189,190HG DEDUCED LEVELS; BAND STRUCTURES; DEFORMATION; ENRICHED TARGETS; COMPTON-SUPPRESSED GE-DETECTORS; CENTRAL ARRAY OF BGO HEXAGONS; CRANKED SHELL MODEL CALCULATIONS ID HIGH-SPIN; SUPERDEFORMED BANDS; YRAST STATES; NUCLEI; MODEL; GD-148; RA AB The level structures of the 189Hg and 190Hg nuclei have been extended considerably from earlier studies by using the Gd-160(S-34, 4n and 5n) reactions in conjunction with an array of twelve Compton suppressed Ge detectors. Eight band structures have been delineated in 189Hg and ten in 190Hg. Most bands can be understood within the framework of cranked shell model calculations assuming an oblate collective shape and specific quasiparticle configurations are proposed. There is also some evidence for the onset of triaxiality. In both nuclei level structures which appear to be non-collective in character are interpreted in a band termination picture. C1 ARGONNE NATL LAB,ARGONNE,IL 60439. EG&G IDAHO INC,IDAHO NATL ENGN LAB,IDAHO FALLS,ID 83415. UNIV NOTRE DAME,NOTRE DAME,IN 46556. RP BEARDEN, IG (reprint author), PURDUE UNIV,W LAFAYETTE,IN 47907, USA. RI Bearden, Ian/M-4504-2014; Carpenter, Michael/E-4287-2015 OI Bearden, Ian/0000-0003-2784-3094; Carpenter, Michael/0000-0002-3237-5734 NR 34 TC 22 Z9 24 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 SEP 5 PY 1994 VL 576 IS 3 BP 441 EP 476 DI 10.1016/0375-9474(94)90253-4 PG 36 WC Physics, Nuclear SC Physics GA PF428 UT WOS:A1994PF42800006 ER PT J AU LUTY, MA MARCHRUSSELL, J AF LUTY, MA MARCHRUSSELL, J TI BARYONS FROM QUARKS IN THE 1/N EXPANSION SO NUCLEAR PHYSICS B LA English DT Article ID STRONG-COUPLING THEORY; LARGE-N-QCD; SKYRME MODEL; HEAVY MESONS; U(1); SOLITON AB We present a new formalism for treating baryons in the 1/N expansion, where N is the number of QCD colors, based on an analysis of quark-level diagrams. This method allows us to derive known results on the large-N limit in a very efficient and transparent manner: we show that there are an infinite number of degenerate baryon states in the large-N limit, and that forward matrix elements of quark bilinear operators satisfy the static quark-model relations. We also derive new results: we enumerate the corrections to the large-N relations to all orders in 1/N, and write an explicit effective lagrangian for baryon chiral perturbation theory which respects chiral symmetry to all orders in 1/N. These results give a simple algorithm to apply the 1/N expansion for baryons at N = 3. Finally, we compare our results for the corrections to the large-N relations to what is expected from a chiral constituent quark model. RP UNIV CALIF BERKELEY, LAWRENCE BERKELEY LAB, THEORET PHYS GRP, 1 CYCLOTRON RD, BERKELEY, CA 94720 USA. NR 27 TC 133 Z9 133 U1 0 U2 0 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0550-3213 EI 1873-1562 J9 NUCL PHYS B JI Nucl. Phys. B PD SEP 5 PY 1994 VL 426 IS 1 BP 71 EP 93 DI 10.1016/0550-3213(94)90126-0 PG 23 WC Physics, Particles & Fields SC Physics GA PH528 UT WOS:A1994PH52800004 ER PT J AU ZELDOV, E LARKIN, AI GESHKENBEIN, VB KONCZYKOWSKI, M MAJER, D KHAYKOVICH, B VINOKUR, VM SHTRIKMAN, H AF ZELDOV, E LARKIN, AI GESHKENBEIN, VB KONCZYKOWSKI, M MAJER, D KHAYKOVICH, B VINOKUR, VM SHTRIKMAN, H TI GEOMETRICAL BARRIERS IN HIGH-TEMPERATURE SUPERCONDUCTORS SO PHYSICAL REVIEW LETTERS LA English DT Article ID FIELD AB A theoretical description of vortex dynamics in thin flat samples is derived and is found to compare favorably with experimental results. In perpendicular applied magnetic field the vortex penetration is delayed significantly due to the presence of a potential barrier of geometrical origin. This novel geometrical barrier effect results in hysteretic magnetization and in the existence of an irreversibility line in the absence of bulk pinning. Among the unique characteristics of the barrier are a vortex concentration in the center of the sample and a zero-field peak in the magnetization loops. C1 LD LANDAU THEORET PHYS INST,MOSCOW 117940,RUSSIA. ECOLE POLYTECH,SOLIDES IRRADIES LAB,F-91128 PALAISEAU,FRANCE. ARGONNE NATL LAB,ARGONNE,IL 60439. RP ZELDOV, E (reprint author), WEIZMANN INST SCI,DEPT CONDENSED MATTER PHYS,IL-76100 REHOVOT,ISRAEL. RI Khaykovich, Boris/A-7376-2012; Zeldov, Eli/K-1546-2012 OI Khaykovich, Boris/0000-0002-9490-2771; Zeldov, Eli/0000-0002-8200-4974 NR 12 TC 537 Z9 540 U1 0 U2 16 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 0031-9007 J9 PHYS REV LETT JI Phys. Rev. Lett. PD SEP 5 PY 1994 VL 73 IS 10 BP 1428 EP 1431 DI 10.1103/PhysRevLett.73.1428 PG 4 WC Physics, Multidisciplinary SC Physics GA PE727 UT WOS:A1994PE72700030 ER PT J AU BROWER, KL MYERS, SM EDWARDS, AH JOHNSON, NM VAN DE WALLE, CG POINDEXTER, EH AF BROWER, KL MYERS, SM EDWARDS, AH JOHNSON, NM VAN DE WALLE, CG POINDEXTER, EH TI ELECTRON-PARAMAGNETIC-RESONANCE OF MOLECULAR-HYDROGEN IN SILICON - COMMENT SO PHYSICAL REVIEW LETTERS LA English DT Note ID 111 SI-SIO2 INTERFACE; HYPERFINE INTERACTIONS; KINETICS; DEFECTS C1 UNIV N CAROLINA, DEPT ELECT ENGN, CHARLOTTE, NC 28223 USA. XEROX CORP, PALO ALTO RES CTR, PALO ALTO, CA 94304 USA. USA, RES LAB, ELECTR & POWER SOURCES DIRECTORATE, FT MONMOUTH, NJ 07703 USA. RP BROWER, KL (reprint author), SANDIA NATL LABS, ALBUQUERQUE, NM 87185 USA. RI Van de Walle, Chris/A-6623-2012 OI Van de Walle, Chris/0000-0002-4212-5990 NR 11 TC 12 Z9 12 U1 1 U2 2 PU AMER PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 0031-9007 EI 1079-7114 J9 PHYS REV LETT JI Phys. Rev. Lett. PD SEP 5 PY 1994 VL 73 IS 10 BP 1456 EP 1456 DI 10.1103/PhysRevLett.73.1456 PG 1 WC Physics, Multidisciplinary SC Physics GA PE727 UT WOS:A1994PE72700037 ER PT J AU TANG, J AF TANG, J TI TUNNELING MECHANISM IN ELECTRON-TRANSFER - A VIEW FROM THE FEYNMANS PATH-INTEGRAL APPROACH SO CHEMICAL PHYSICS LETTERS LA English DT Article ID ENERGY-GAP LAW; BIOLOGICAL MOLECULES; CONDENSED PHASES; POLAR-SOLVENTS; QUANTUM MODES; DYNAMICS; TRANSITIONS; DISSIPATION; MEDIA AB The Feynman's path integral approach is used to analyze the quantum tunneling mechanism in electron-transfer reactions. A transition function W(T)(x) is derived in terms of the reaction coordinate, displaying multi-phonon tunneling transitions. This method offers better insights and improves our understanding of the tunneling mechanism. It provides a smooth connection between the high-temperature classical regime and the low-temperature quantum tunneling regime. RP TANG, J (reprint author), ARGONNE NATL LAB, DIV CHEM, ARGONNE, IL 60439 USA. RI Tang, Jau/D-8382-2012 OI Tang, Jau/0000-0003-2078-1513 NR 38 TC 8 Z9 8 U1 1 U2 1 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0009-2614 EI 1873-4448 J9 CHEM PHYS LETT JI Chem. Phys. Lett. PD SEP 2 PY 1994 VL 227 IS 1-2 BP 170 EP 179 DI 10.1016/0009-2614(94)00806-X PG 10 WC Chemistry, Physical; Physics, Atomic, Molecular & Chemical SC Chemistry; Physics GA PE835 UT WOS:A1994PE83500029 ER PT J AU DANG, LX AF DANG, LX TI FREE-ENERGIES FOR ASSOCIATION OF CS+ TO 18-CROWN-6 IN WATER - A MOLECULAR-DYNAMICS STUDY INCLUDING COUNTER IONS SO CHEMICAL PHYSICS LETTERS LA English DT Article AB Molecular dynamics simulations have been performed to obtain free energy profiles, for the association of Cs+ to 18-crown-6 in water. This is the first study of cation-crown ether interactions in aqueous solutions that explicitly includes the counter ion. This work also provides the first quantitative measurement of the influence of the counter ion on the Cs+: 18-crown-6 complex potential of mean force and the related thermodynamic properties. Our results illustrate the validity of the potential function and the power of the molecular dynamics approach to the study of of cation-crown ether interactions in aqueous solutions. RP DANG, LX (reprint author), PACIFIC NW LAB, MOLEC SCI RES CTR, RICHLAND, WA 99352 USA. NR 20 TC 45 Z9 45 U1 1 U2 10 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0009-2614 J9 CHEM PHYS LETT JI Chem. Phys. Lett. PD SEP 2 PY 1994 VL 227 IS 1-2 BP 211 EP 214 DI 10.1016/0009-2614(94)00810-8 PG 4 WC Chemistry, Physical; Physics, Atomic, Molecular & Chemical SC Chemistry; Physics GA PE835 UT WOS:A1994PE83500034 ER PT J AU HEADGORDON, T AF HEADGORDON, T TI AN EFFICIENT SOLVENT MODEL FOR STUDY OF HYDROPHOBIC PHENOMENA SO CHEMICAL PHYSICS LETTERS LA English DT Article ID MOLECULAR-DYNAMICS SIMULATIONS; LIQUID WATER; COMPUTER-SIMULATIONS; TEMPERATURE; METHANE; FORCES AB We have recently introduced a new Hamiltonian for water which accurately describes the thermodynamics of methane association in solution at 25-degrees-C and 1 atm. This work quantifies potentially important advances for characterizing the structure and thermodynamics of hydrophobic solvation in the future. When compared to commonly used multi-site water models, the new model provides (1) a straightforward procedure for extrapolating the one-site description of water to other thermodynamic points of interest, (2) an order of magnitude gain in computational speed, and (3) statistical confidence for quantities such as the entropy which is comparable to free energies evaluated with traditional water models. RP HEADGORDON, T (reprint author), LAWRENCE BERKELEY LAB,DIV LIFE SCI,BERKELEY,CA 94720, USA. RI Head-Gordon, Teresa/E-5818-2011 NR 39 TC 19 Z9 19 U1 0 U2 0 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0009-2614 J9 CHEM PHYS LETT JI Chem. Phys. Lett. PD SEP 2 PY 1994 VL 227 IS 1-2 BP 215 EP 220 DI 10.1016/0009-2614(94)00811-6 PG 6 WC Chemistry, Physical; Physics, Atomic, Molecular & Chemical SC Chemistry; Physics GA PE835 UT WOS:A1994PE83500035 ER PT J AU MCINTYRE, BJ SALMERON, M SOMORJAI, GA AF MCINTYRE, BJ SALMERON, M SOMORJAI, GA TI NANOCATALYSIS BY THE TIP OF A SCANNING TUNNELING MICROSCOPE OPERATING INSIDE A REACTOR CELL SO SCIENCE LA English DT Article ID SINGLE-CRYSTAL SURFACES; DEUTERIUM-EXCHANGE REACTIONS; ENERGY LOSS SPECTROSCOPY; PT(111); DECOMPOSITION; HYDROGENATION; DESORPTION; ETHYLENE; SCIENCE AB The platinum-rhodium tip of a scanning tunneling microscope that operates inside of an atmospheric-pressure chemical reactor cell has been used to locally rehydrogenate carbonaceous fragments deposited on the (111) surface of platinum. The carbon fragments were produced by partial dehydrogenation of propylene. The reactant gas environment inside the cell consisted of pure H-2 or a 1:9 mixture of CH3CHCH2 and H-2 at 300 kelvin. The platinum-rhodium tip acted as a catalyst after activation by short voltage pulses. In this active state, the clusters in the area scanned by the tip were reacted away with very high spatial resolution. C1 UNIV CALIF BERKELEY,DEPT CHEM,BERKELEY,CA 94720. RP MCINTYRE, BJ (reprint author), UNIV CALIF BERKELEY,LAWRENCE BERKELEY LAB,CTR ADV MAT,DIV MAT SCI,BERKELEY,CA 94720, USA. NR 18 TC 65 Z9 65 U1 1 U2 12 PU AMER ASSOC ADVANCEMENT SCIENCE PI WASHINGTON PA 1200 NEW YORK AVE, NW, WASHINGTON, DC 20005 SN 0036-8075 J9 SCIENCE JI Science PD SEP 2 PY 1994 VL 265 IS 5177 BP 1415 EP 1418 DI 10.1126/science.265.5177.1415 PG 4 WC Multidisciplinary Sciences SC Science & Technology - Other Topics GA PE733 UT WOS:A1994PE73300039 PM 17833813 ER PT J AU MORE, JJ THUENTE, DJ AF MORE, JJ THUENTE, DJ TI LINE SEARCH ALGORITHMS WITH GUARANTEED SUFFICIENT DECREASE SO ACM TRANSACTIONS ON MATHEMATICAL SOFTWARE LA English DT Article DE ALGORITHMS; CONJUGATE GRADIENT ALGORITHMS; LINE SEARCH ALGORITHMS; NONLINEAR OPTIMIZATION; TRUNCATED NEWTON ALGORITHMS; VARIABLE METRIC ALGORITHMS ID NEWTON MINIMIZATION PACKAGE; LARGE-SCALE PROBLEMS; GLOBAL CONVERGENCE; TNPACK AB The development of software for minimization problems is often based on a line search method. We consider line search methods that satisfy sufficient decrease and curvature conditions, and formulate the problem of determining a point that satisfies these two conditions in terms of finding a point in a set T(mu). We describe a search algorithm for this problem that produces a sequence of iterates that converge to a point in T(mu) and that, except for pathological cases, terminates in a finite number of steps. Numerical results for an implementation of the search algorithm on a set of test functions show that the algorithm terminates within a small number of iterations. C1 INDIANA PURDUE UNIV,DEPT MATH SCI,FT WAYNE,IN 46805. RP MORE, JJ (reprint author), ARGONNE NATL LAB,DIV MATH & COMP SCI,9700 S CASS AVE,ARGONNE,IL 60439, USA. NR 20 TC 204 Z9 205 U1 4 U2 10 PU ASSOC COMPUTING MACHINERY PI NEW YORK PA 1515 BROADWAY, NEW YORK, NY 10036 SN 0098-3500 J9 ACM T MATH SOFTWARE JI ACM Trans. Math. Softw. PD SEP PY 1994 VL 20 IS 3 BP 286 EP 307 DI 10.1145/192115.192132 PG 22 WC Computer Science, Software Engineering; Mathematics, Applied SC Computer Science; Mathematics GA PR442 UT WOS:A1994PR44200004 ER PT J AU SANISHVILI, RG MARGOLIASH, E WESTBROOK, ML WESTBROOK, EM VOLZ, KW AF SANISHVILI, RG MARGOLIASH, E WESTBROOK, ML WESTBROOK, EM VOLZ, KW TI CRYSTALLIZATION OF WILD-TYPE AND MUTANT FERRICYTOCHROMES-C AT LOW IONIC-STRENGTH - SEEDING TECHNIQUE AND X-RAY-DIFFRACTION ANALYSIS SO ACTA CRYSTALLOGRAPHICA SECTION D-BIOLOGICAL CRYSTALLOGRAPHY LA English DT Article ID RESOLUTION 3-DIMENSIONAL STRUCTURE; IMAGING PROPORTIONAL COUNTER; CYTOCHROME-C; FERROCYTOCHROME-C; CRYSTAL-STRUCTURE; ELECTROSTATIC INTERACTIONS; YEAST ISO-1-CYTOCHROME-C; POLYETHYLENE-GLYCOL; CONFORMATION CHANGE; PROTEINS AB Ferricytochromes c were crystallized at low ionic strength by macroseeding techniques. Large crystals were grown by seed-induced self-nucleation which occurred anywhere in the drop, regardless of the location of the seed crystal. This unusual crystal-seeding method worked reproducibly in our hands, and X-ray quality crystals have been prepared of several ferricytochromes c: horse, rat (recombinant wild type), and two site-directed mutants of the latter, tyrosine 67 to phenylalanine (Y67F) and asparagine 52 to isoleucine (N52I). Crystals of any one of these four proteins could be used as seeds for the crystallization of any one of the others. All the crystals are of the same crystal form, with space group P2(1)2(1)2(1). There are two protein molecules per asymmetric unit. The crystals are stable in the X-ray beam and diffract to at least 2.0 angstrom resolution. Full crystallographic data sets have been collected from single crystals of all four proteins. C1 UNIV ILLINOIS,DEPT BIOL SCI,MOLEC BIOL LAB,4297A SEL M-C 067,840 W TAYLOR ST,CHICAGO,IL 60607. ARGONNE NATL LAB,DIV BIOL & MED RES,ARGONNE,IL 60439. UNIV ILLINOIS,DEPT MICROBIOL & IMMUNOL,CHICAGO,IL 60612. NR 46 TC 10 Z9 10 U1 0 U2 1 PU MUNKSGAARD INT PUBL LTD PI COPENHAGEN PA 35 NORRE SOGADE, PO BOX 2148, DK-1016 COPENHAGEN, DENMARK SN 0907-4449 J9 ACTA CRYSTALLOGR D JI Acta Crystallogr. Sect. D-Biol. Crystallogr. PD SEP 1 PY 1994 VL 50 BP 687 EP 694 DI 10.1107/S0907444994002568 PN 5 PG 8 WC Biochemical Research Methods; Biochemistry & Molecular Biology; Biophysics; Crystallography SC Biochemistry & Molecular Biology; Biophysics; Crystallography GA PK568 UT WOS:A1994PK56800003 PM 15299366 ER PT J AU BAEYENS, KJ JANCARIK, J HOLBROOK, SR AF BAEYENS, KJ JANCARIK, J HOLBROOK, SR TI USE OF LOW-MOLECULAR-WEIGHT POLYETHYLENE-GLYCOL IN THE CRYSTALLIZATION OF RNA OLIGOMERS SO ACTA CRYSTALLOGRAPHICA SECTION D-BIOLOGICAL CRYSTALLOGRAPHY LA English DT Article ID PURIFICATION; DNA AB We have crystallized a variety of RNA oligonucleotides in a form suitable for X-ray diffraction studies using polyethylene glycol with a low-molecular-weight distribution (PEG 400) as the precipitant. Crystallization experiments on a set of 26 RNA oligomers ranging from eight to 12 nucleotides in length resulted in eight diffraction-quality crystals. Of these eight RNA crystals, six utilized PEG 400 as the precipitating agent. We have also been able to obtain large single crystals of a DNA-RNA hybrid, transfer RNA (two different conditions) and a catalytic RNA from PEG 400 solutions. These results suggest that PEG 400 may be a generally useful alternative to 2-methyl-2,4-pentanediol (MPD) which has, thus far, been the most successful precipitant for DNA oligomers. C1 LAWRENCE BERKELEY LAB,MELVIN CALVIN LAB,DIV STRUCT BIOL,BERKELEY,CA 94720. UNIV CALIF BERKELEY,DEPT CHEM,BERKELEY,CA 94720. NR 11 TC 17 Z9 17 U1 0 U2 1 PU MUNKSGAARD INT PUBL LTD PI COPENHAGEN PA 35 NORRE SOGADE, PO BOX 2148, DK-1016 COPENHAGEN, DENMARK SN 0907-4449 J9 ACTA CRYSTALLOGR D JI Acta Crystallogr. Sect. D-Biol. Crystallogr. PD SEP 1 PY 1994 VL 50 BP 764 EP 767 DI 10.1107/S0907444994003458 PN 5 PG 4 WC Biochemical Research Methods; Biochemistry & Molecular Biology; Biophysics; Crystallography SC Biochemistry & Molecular Biology; Biophysics; Crystallography GA PK568 UT WOS:A1994PK56800012 PM 15299375 ER PT J AU DAVIES, C GERCHMAN, SE KYCIA, JH MCGEE, K RAMAKRISHNAN, V WHITE, SW AF DAVIES, C GERCHMAN, SE KYCIA, JH MCGEE, K RAMAKRISHNAN, V WHITE, SW TI CRYSTALLIZATION AND PRELIMINARY-X-RAY DIFFRACTION STUDIES OF BACTERIAL RIBOSOMAL PROTEIN-L14 SO ACTA CRYSTALLOGRAPHICA SECTION D-BIOLOGICAL CRYSTALLOGRAPHY LA English DT Note ID RNA-BINDING DOMAIN; ESCHERICHIA-COLI; CRYSTAL-STRUCTURE; BACILLUS-STEAROTHERMOPHILUS; 3-DIMENSIONAL STRUCTURE; SUBUNIT; COMPONENT; MODEL AB Based on amino-acid sequence homology, it is predicted that ribosomal protein L14 is a member of a recently identified family of structurally related RNA-binding proteins. To verify this, the gene for Bacillus stearothermophilus L14 has been cloned, and the protein has been purified and crystallized. The crystals are in space group C2 with cell dimensions a = 67.0, b = 32.7, c = 49.4 angstrom, and beta = 101.8-degrees, and there is one molecule in the asymmetric unit (V(m) = 2.0 angstrom 3 Da-1). They are of high quality, and a native data set has been collected to a resolution of 1.6 angstrom with an R(merge) of 5.3%. C1 BROOKHAVEN NATL LAB,DEPT BIOL,UPTON,NY 11973. RP DAVIES, C (reprint author), DUKE UNIV,MED CTR,DEPT MICROBIOL,DURHAM,NC 27710, USA. OI Ramakrishnan, V/0000-0002-4699-2194 NR 25 TC 2 Z9 2 U1 0 U2 0 PU MUNKSGAARD INT PUBL LTD PI COPENHAGEN PA 35 NORRE SOGADE, PO BOX 2148, DK-1016 COPENHAGEN, DENMARK SN 0907-4449 J9 ACTA CRYSTALLOGR D JI Acta Crystallogr. Sect. D-Biol. Crystallogr. PD SEP 1 PY 1994 VL 50 BP 790 EP 792 DI 10.1107/S0907444994004117 PN 5 PG 3 WC Biochemical Research Methods; Biochemistry & Molecular Biology; Biophysics; Crystallography SC Biochemistry & Molecular Biology; Biophysics; Crystallography GA PK568 UT WOS:A1994PK56800017 PM 15299380 ER PT J AU TULLOCK, DL REIMANIS, IE GRAHAM, AL PETROVIC, JJ AF TULLOCK, DL REIMANIS, IE GRAHAM, AL PETROVIC, JJ TI DEFLECTION AND PENETRATION OF CRACKS AT AN INTERFACE BETWEEN 2 DISSIMILAR MATERIALS SO ACTA METALLURGICA ET MATERIALIA LA English DT Article ID BOUNDARY ELEMENT ANALYSIS; MATRIX COMPOSITES AB The tendency of a crack to deflect or penetrate at an interface between two dissimilar elastic materials in a finite-sized sample is investigated with the boundary element method. The ratio of the energy release rate of a deflecting crack to the maximum energy release rate of a penetrating crack is computed as a function of the Dundurs' elastic mismatch parameters for several double-edged notch specimen geometries and loading conditions. Over the entire range of material parameters, the results displayed only a weak dependence on the loading conditions imposed on the specimen, the aspect ratio of the specimen, and on Dundurs' parameter, beta. For moderate differences in the relative stiffnesses of the two materials and when the crack is advancing toward a stiffer material, we find essentially no difference between the singly and doubly deflected crack, and the numerical calculations are in excellent agreement with recent analytical predictions [1]. However, when the crack is advancing into a material of much lower modulus, the numerical calculations for a doubly deflected crack are smaller than the analytical predictions. C1 LOS ALAMOS NATL LAB, LOS ALAMOS, NM 87544 USA. UNIV SYDNEY, DEPT MECH ENGN, SYDNEY, NSW 2006, AUSTRALIA. NR 20 TC 29 Z9 30 U1 1 U2 8 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLAND SN 0956-7151 J9 ACTA METALL MATER JI Acta Metall. Mater. PD SEP PY 1994 VL 42 IS 9 BP 3245 EP 3252 DI 10.1016/0956-7151(94)90422-7 PG 8 WC Materials Science, Multidisciplinary; Metallurgy & Metallurgical Engineering SC Materials Science; Metallurgy & Metallurgical Engineering GA PB268 UT WOS:A1994PB26800035 ER PT J AU AHLUWALIA, DV GOLDMAN, T JOHNSON, MB AF AHLUWALIA, DV GOLDMAN, T JOHNSON, MB TI (J,0)CIRCLE-PLUS(0,J) REPRESENTATION SPACE - MAJORANA-LIKE CONSTRUCT SO ACTA PHYSICA POLONICA B LA English DT Article; Proceedings Paper CT XVIII International School of Theoretical Physics: Standard Model and Beyond 93 CY SEP 19-27, 1993 CL SZCZYRK, POLAND ID SPIN AB This is second of the two invited lectures presented at the ''XVII International School of Theoretical Physics: Standard Model and Beyond' 93.'' The text is essentially based on a recent publication by the present authors [Mod. Phys. Lett. A (in press)]. Here, after briefly reviewing the (j, 0) + (0, j) Dirac-like construct in the front form, we present a detailed construction of the (j, 0) + (0, j) Majorana-like fields. RP AHLUWALIA, DV (reprint author), LOS ALAMOS NATL LAB,LOS ALAMOS,NM 87545, USA. NR 21 TC 12 Z9 12 U1 0 U2 0 PU POLISH ACAD SCIENCES INST PHYSICS PI WARSAW PA AL LOTNIKOW 32-46, 02-668 WARSAW, POLAND SN 0587-4254 J9 ACTA PHYS POL B JI Acta Phys. Pol. B PD SEP PY 1994 VL 25 IS 9 BP 1267 EP 1278 PG 12 WC Physics, Multidisciplinary SC Physics GA PL154 UT WOS:A1994PL15400002 ER PT J AU HENDREY, GR KIMBALL, BA AF HENDREY, GR KIMBALL, BA TI THE FACE PROGRAM SO AGRICULTURAL AND FOREST METEOROLOGY LA English DT Article ID ATMOSPHERIC CARBON-DIOXIDE; AIR CO-2 ENRICHMENT; OPEN-TOP CHAMBER; ELEVATED CO2; FIELD; PHOTOSYNTHESIS; POPULATIONS; ECOSYSTEMS; VEGETATION; EXPOSURE AB A large, cooperative, integrated experimental program utilizing free-air CO2 enrichment (FACE) is being conducted to expose plants to elevated concentrations of CO2. The goals are to evaluate the effects of increasing atmospheric CO2 on plants and ecosystems and, in the long run, to contribute to the evaluation of terrestrial plant feedback regulation on the rate of change of CO2 in the atmosphere. Having no walls, the FACE system allows plants to be grown under realistic microclimate and CO2 conditions expected to prevail in the mid-twenty-first century. Data obtained under such conditions are needed for validation of models being developed to predict the effects of increasing CO2 and changing climate variables on plants, ecosystems, agricultural productivity and water resources. Setup costs for the FACE systems used in these experiments are similar to the costs of field chamber systems. Although annual operating costs are about three times the cost of field chambers, FACE plots are relatively large, leading to an economy of scale, so that per unit of treated plant material, FACE systems are the least expensive approach for well-integrated field experiments. These features have provided an incentive to conduct comprehensive FACE experiments with many cooperating scientists working together to measure numerous plant, soil and micrometeorological parameters, as described in the collection of papers in this special issue of 'Agricultural and Forest Meterology'. C1 USDA ARS,WATER CONSERVAT LAB,PHOENIX,AZ 85040. RP HENDREY, GR (reprint author), BROOKHAVEN NATL LAB,DEPT APPL SCI,UPTON,NY 11973, USA. NR 36 TC 96 Z9 103 U1 3 U2 14 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0168-1923 J9 AGR FOREST METEOROL JI Agric. For. Meteorol. PD SEP PY 1994 VL 70 IS 1-4 BP 3 EP 14 DI 10.1016/0168-1923(94)90044-2 PG 12 WC Agronomy; Forestry; Meteorology & Atmospheric Sciences SC Agriculture; Forestry; Meteorology & Atmospheric Sciences GA PK499 UT WOS:A1994PK49900002 ER PT J AU LEWIN, KF HENDREY, GR NAGY, J LAMORTE, RL AF LEWIN, KF HENDREY, GR NAGY, J LAMORTE, RL TI DESIGN AND APPLICATION OF A FREE-AIR CARBON-DIOXIDE ENRICHMENT FACILITY SO AGRICULTURAL AND FOREST METEOROLOGY LA English DT Article AB Growth chambers and other enclosures used in plant physiology and growth studies tend to introduce chamber effects that alter the microclimate around the plants compared with the natural environment. A free-air (chamberless) carbon dioxide enrichment (FACE) system has been developed by Brookhaven National Laboratory (BNL) to provide controlled fumigation conditions while minimizing the potential to impose a discernible chamber effect. This system is capable of exposing large numbers of field-grown plants to elevated levels of atmospheric carbon dioxide (CO2) from seedling emergence until physiologic maturity. A FACE User Facility was established at the Maricopa Agricultural Center, University of Arizona, for continuous enrichment of CO2 at a set point of 550 mumol mol-1 during daylight hours throughout the cotton crop growing seasons of 1989-1991. The facility consisted of four circular BNL FACE arrays and associated equipment placed in a commercial cotton plantation. FACE array diameters of 23, 25, and 27 m were tested. The FACE facility included the ability to operate the experimental plots under two watering regimes using an automated, sub-surface irrigation system. CO2 was stored in a 48 000 kg receiver and vaporized with a heat exchanger that used water at ambient temperature as the energy source. The 1 min average CO2 concentration was held to within +/- 20% of the set point more than 98% of the time that the arrays were operating during all three seasons. In 1991, the long term average CO2 concentration measured at 63 points throughout the volume of a 20 m diameter experimental plot (ground to canopy top) centered within a 25 m diameter FACE array was 568 mumol mol-1. All of the FACE arrays operated for more than 99% of the planned experimental period in 1991. These 3 years of operation have demonstrated that the BNL FACE technology can be used as a basis for a large scale facility devoted to studying the fate of carbon in the terrestrial environment. C1 USDA ARS,US WATER CONSERVAT LAB,PHOENIX,AZ 85040. RP LEWIN, KF (reprint author), BROOKHAVEN NATL LAB,DEPT APPL SCI,UPTON,NY 11973, USA. NR 14 TC 120 Z9 123 U1 1 U2 7 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0168-1923 J9 AGR FOREST METEOROL JI Agric. For. Meteorol. PD SEP PY 1994 VL 70 IS 1-4 BP 15 EP 29 DI 10.1016/0168-1923(94)90045-0 PG 15 WC Agronomy; Forestry; Meteorology & Atmospheric Sciences SC Agriculture; Forestry; Meteorology & Atmospheric Sciences GA PK499 UT WOS:A1994PK49900003 ER PT J AU NAGY, J LEWIN, KF HENDREY, GR HASSINGER, E LAMORTE, R AF NAGY, J LEWIN, KF HENDREY, GR HASSINGER, E LAMORTE, R TI FACE FACILITY CO2 CONCENTRATION CONTROL AND CO2 USE IN 1990 AND 1991 SO AGRICULTURAL AND FOREST METEOROLOGY LA English DT Article ID FIELD CROPS; SYSTEM AB CO2 treatment level control and CO2 use are reported for free-air carbon dioxide enrichment (FACE) facility operations at the University of Arizona's Maricopa Agricultural Center in 1990 and 1991. These are required for evaluation of the validity of biological experiments conducted in four replicates of paired experimental and control plots in a large cotton field and the cost-effectiveness of the plant fumigation facility. Gas concentration was controlled to 550 mumol mol-1 at the center of each experimental plot, just above the canopy. In both years, season-long (April-September) average CO2 levels during treatment hours (05:00-19:00 h Mountain Standard Time) were 550 mumol mol-1 measured at treatment plot centers when the facility was operating. Including downtime, the season average was 548 mumol mol-1 in 1991. In 1990, the season averages for the four elevated CO2 treatments varied from 522 to 544 mumol mol-1, owing to extended periods of downtime after lightning damage. Ambient CO2 concentration during treatment was 370 mumol mol-1. Instantaneous measurements of CO2 concentration were within 10% of the target concentration of 550 mumol mol-1 more than 65% of the time when the facility was operating, and 1 min averages were within 10% of the target concentration for 90% of the time. The long-term average of CO2 concentration measured over the 20 m diameter experimental area of one array at the height of the canopy was in the range 550-580 mumol mol-1 during July 1991, with the higher values near the edges. In 1991, CO2 demand averaged 1250 kg per array per 14 h treatment day, or 4 kg m-2 of fumigated plant canopy. The FACE facility provided good temporal and spatial control of CO2 concentration and was a cost-effective method for large-scale field evaluations of the biological effects of CO2. C1 USDA ARS,WATER CONSERVAT LAB,PHOENIX,AZ 85040. RP NAGY, J (reprint author), BROOKHAVEN NATL LAB,DEPT APPL SCI,DIV BIOSYST & PROC SCI,UPTON,NY 11973, USA. NR 9 TC 43 Z9 44 U1 0 U2 1 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0168-1923 J9 AGR FOREST METEOROL JI Agric. For. Meteorol. PD SEP PY 1994 VL 70 IS 1-4 BP 31 EP 48 DI 10.1016/0168-1923(94)90046-9 PG 18 WC Agronomy; Forestry; Meteorology & Atmospheric Sciences SC Agriculture; Forestry; Meteorology & Atmospheric Sciences GA PK499 UT WOS:A1994PK49900004 ER PT J AU MAUNEY, JR KIMBALL, BA PINTER, PJ LAMORTE, RL LEWIN, KF NAGY, J HENDREY, GR AF MAUNEY, JR KIMBALL, BA PINTER, PJ LAMORTE, RL LEWIN, KF NAGY, J HENDREY, GR TI GROWTH AND YIELD OF COTTON IN RESPONSE TO A FREE-AIR CARBON-DIOXIDE ENRICHMENT (FACE) ENVIRONMENT SO AGRICULTURAL AND FOREST METEOROLOGY LA English DT Article AB To quantify the growth and yield responses to CO2 enrichment in an open field setting, free-air CO2 enrichment (FACE) technology was used to expose a cotton (Gossypium hirustum L.) crop to 550 mumol mol-1 CO2 throughout the growing seasons of 1989, 1990 and 1991 in fields near Maricopa, Arizona. In 1990 and 1991 a water stress treatment was also imposed. Response data for all years were consistent, and the data for 1991 were the least compromised by unusual weather or equipment failures. In that season the biomass was increased 37% by the 48% increase in CO2 concentration. Harvestable yield was increased 43%. The increase in biomass and yield was attributed to increased early leaf area, more profuse flowering and a longer period of fruit retention. The FACE treatment increased water-use efficiency (WUE) to the same amount in the well-irrigated plots as in the water-stressed plots. The increase in WUE was due to the increase in biomass production rather than a reduction of consumptive use. C1 USDA ARS,US WATER CONSERVAT LAB,PHOENIX,AZ 85040. BROOKHAVEN NATL LAB,UPTON,NY 11973. RP MAUNEY, JR (reprint author), USDA ARS,WESTERN COTTON RES LAB,4135 E BROADWAY RD,PHOENIX,AZ 85040, USA. NR 24 TC 102 Z9 118 U1 2 U2 9 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0168-1923 J9 AGR FOREST METEOROL JI Agric. For. Meteorol. PD SEP PY 1994 VL 70 IS 1-4 BP 49 EP 67 DI 10.1016/0168-1923(94)90047-7 PG 19 WC Agronomy; Forestry; Meteorology & Atmospheric Sciences SC Agriculture; Forestry; Meteorology & Atmospheric Sciences GA PK499 UT WOS:A1994PK49900005 ER PT J AU LEAVITT, SW PAUL, EA KIMBALL, BA HENDREY, GR MAUNEY, JR RAUSCHKOLB, R ROGERS, H LEWIN, KF NAGY, J PINTER, PJ JOHNSON, HB AF LEAVITT, SW PAUL, EA KIMBALL, BA HENDREY, GR MAUNEY, JR RAUSCHKOLB, R ROGERS, H LEWIN, KF NAGY, J PINTER, PJ JOHNSON, HB TI CARBON-ISOTOPE DYNAMICS OF FREE-AIR CO2-ENRICHED COTTON AND SOILS SO AGRICULTURAL AND FOREST METEOROLOGY LA English DT Article ID ABUNDANCE; FLUXES; ROOT AB A role for soils as global carbon sink or source under increasing atmospheric CO2 concentrations has been speculative. Free-air carbon dioxide enrichment (FACE) experiments with cotton, conducted from 1989 to 1991 at the Maricopa Agricultural Center in Arizona, maintained circular plots at 550 mumol mol-1 CO2 with tank CO2 while adjacent ambient control plots averaged about 370 mumol mol-1 CO2. This provided an exceptional test for entry of carbon into soils because the petrochemically derived tank CO2 used to enrich the air above the FACE plots was depleted in both radiocarbon (C-14 content was 0% modern carbon (pmC)) and C-13 (delta13 C almost-equal-to -36 parts per thousand) relative to background air, thus serving as a potent isotopic tracer. Flask air samples, and plant and soil samples were collected in conjunction with the 1991 experiment. Most of the isotopic analyses on the plants were performed on the holecellulose component. Soil organic carbon was obtained by first removing carbonate with HCl, floating off plant fragments with a NaCl solution, and picking out remaining plant fragments under magnification. The delta C-13 of the air above the FACE plots was approximately - 15 to - 19 parts per thousand, i.e. much more C-13 depleted than the background air of approximately -7.5parts per thousand. The delta C-13 values of plants and soils in the FACE plots were 10-12 parts per thousand and 2 parts per thousand C-13-depleted, respectively, compared with their control counterparts. The C-14 content of the FACE cotton plants was approximately 40 pmC lower than that of the control cotton, but the C-14 results from soils were conflicting and therefore not as revealing as the delta C-13 of soils. Soil stable-carbon isotope patterns were consistent, and mass balance calculations indicate that about 10% of the present organic carbon content in the FACE soil derived from the 3 year FACE experiment. At a minimum, this is an important quantitative measure of carbon turnover, but the presence of C-13-depleted carbon, even in the recalcitrant 6 N HCl resistant soil organic fraction (average age 2200 years before present (BP)), suggests that at least some portion of this 10% is an actual increase in carbon accumulation. Similar isotopic studies on FACE experiments in different ecosystems could permit more definitive assessment of carbon turnover rates and perhaps provide insight into the extent to which soil organic matter can accommodate the 'missing' carbon in the global carbon cycle. C1 MICHIGAN STATE UNIV,DEPT CROP & SOIL SCI,E LANSING,MI 48824. USDA ARS,US WATER CONSERVAT LAB,PHOENIX,AZ 85040. USDA ARS,WESTERN COTTON RES LAB,PHOENIX,AZ 85040. USDA ARS,NATL SOILS DYNAM LAB,AUBURN,AL 36831. USDA ARS,GRASSLAND SOIL & WATER RES LAB,TEMPLE,TX 76502. BROOKHAVEN NATL LAB,DEPT APPL SCI,UPTON,NY 11973. UNIV ARIZONA,MARICOPA AGR CTR,MARICOPA,AZ 85239. RP LEAVITT, SW (reprint author), UNIV ARIZONA,TREE RING RES LAB,TUCSON,AZ 85721, USA. NR 24 TC 65 Z9 69 U1 4 U2 16 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0168-1923 J9 AGR FOREST METEOROL JI Agric. For. Meteorol. PD SEP PY 1994 VL 70 IS 1-4 BP 87 EP 101 DI 10.1016/0168-1923(94)90049-3 PG 15 WC Agronomy; Forestry; Meteorology & Atmospheric Sciences SC Agriculture; Forestry; Meteorology & Atmospheric Sciences GA PK499 UT WOS:A1994PK49900007 ER PT J AU NAKAYAMA, FS HULUKA, G KIMBALL, BA LEWIN, KF NAGY, J HENDREY, GR AF NAKAYAMA, FS HULUKA, G KIMBALL, BA LEWIN, KF NAGY, J HENDREY, GR TI SOIL CARBON-DIOXIDE FLUXES IN NATURAL AND CO2-ENRICHED SYSTEMS SO AGRICULTURAL AND FOREST METEOROLOGY LA English DT Article ID RESPIRATION AB Carbon dioxide fluxes between the soil and atmosphere were determined on the 1991 free-air carbon dioxide enrichment (FACE) experiment at the Maricopa Agricultural Center, Maricopa, Arizona. The study was conducted on drip-irrigated cotton in conjunction with other physical and physiological measurements. Fluxes were measured with a 1.6 l closed-chamber static sampling system. The main treatment for the open-air release study had two levels of CO2-ambient air with CO2 concentration of approximately 370 mumol mol-1 (control) and CO2-enriched air with CO2 concentration of approximately 550 mumol mol-1 (FACE). The enrichment was made over the daylight hours (05:00-19:00 h). Two quantities of water application, 'wet' (1050 mm) and 'dry' (790 mm), were superimposed on the two CO2 levels. The observed soil CO2 fluxes ranged from 2 to 8 mumol m-2 s-1 over the cultivation period. The CO2 fluxes were significantly higher in the FACE than in the control plots, and also higher for the wet than for the dry irrigation level. In addition, an interaction between CO2 and water levels was present. The CO2 enrichment effect on soil CO2 flux remained for approximately 4 weeks after the enrichment was ended. A detailed study on the procedure for determining flux indicated that some of the random and inconsistent flux values observed in the field could be attributed to a high CO2 concentration present in the first of the two gas samples taken to estimate flux. C1 TUSKEGEE UNIV,DEPT AGR SCI,TUSKEGEE,AL 36088. BROOKHAVEN NATL LAB,DEPT APPL SCI,UPTON,NY 11973. RP NAKAYAMA, FS (reprint author), US WATER CONSERVAT LAB,4331 E BROADWAY RD,PHOENIX,AZ 85040, USA. NR 17 TC 28 Z9 34 U1 1 U2 2 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0168-1923 J9 AGR FOREST METEOROL JI Agric. For. Meteorol. PD SEP PY 1994 VL 70 IS 1-4 BP 131 EP 140 DI 10.1016/0168-1923(94)90052-3 PG 10 WC Agronomy; Forestry; Meteorology & Atmospheric Sciences SC Agriculture; Forestry; Meteorology & Atmospheric Sciences GA PK499 UT WOS:A1994PK49900010 ER PT J AU HULUKA, G HILEMAN, DR BISWAS, PK LEWIN, KF NAGY, J HENDREY, GR AF HULUKA, G HILEMAN, DR BISWAS, PK LEWIN, KF NAGY, J HENDREY, GR TI EFFECTS OF ELEVATED CO2 AND WATER-STRESS ON MINERAL CONCENTRATION OF COTTON SO AGRICULTURAL AND FOREST METEOROLOGY LA English DT Article ID CARBON-DIOXIDE; NUTRIENT CONCENTRATIONS; DRY-MATTER; GROWTH; PLANTS; ACCLIMATION; ENRICHMENT; NITROGEN; STARCH; LEPIDOPTERA AB Projected increases in atmospheric CO2 concentrations may alter mineral and protein levels in plant tissues, systematically affecting growth, nutrient cycling and utilization, residue decomposition, and insect-plant interactions in the future. The free-air CO2 enrichment (FACE) system provided an opportunity to monitor seasonal trends in nutrient status and crude protein content of cotton (Gossypium hirsutum L. cv. Deltapine 77) grown in a natural field setting without the limitations often imposed by growth chambers or reduced rooting volumes. In 1990, plants were exposed to two levels of atmospheric CO2 (FACE, almost-equal-to 550 mumol mol-1 and CONTROL, almost-equal-to 370 mumol mol-1) and two irrigation regimes (100% and 75% replacement of evapotranspiration) beginning in early July. Cotton leaves, stem, and roots were sampled at different times during the season and analyzed for C, N, Ca, K, Mg, P, Cu, Fe, Mn, Zn, B, Mo, Si and protein. The N and protein concentrations of leaves, stems and roots were significantly lower in FACE plants than in CONTROL plants, but C:N ratios were higher for the FACE plants than the CONTROL plants. Some other elements were significantly affected by CO2 enrichment, but not for all dates and all plant tissues. There were no significant effects in any of the data because of the irrigation treatment or the irrigation-CO2 interaction. Reductions in tissue N and protein concentrations and the increases in the C:N with CO2 enrichment have important implications for agricultural and natural systems and demand additional research. C1 TUSKEGEE UNIV,DEPT BIOL,TUSKEGEE,AL 36088. BROOKHAVEN NATL LAB,DEPT APPL SCI,UPTON,NY 11973. RP HULUKA, G (reprint author), TUSKEGEE UNIV,DEPT AGR SCI,TUSKEGEE,AL 36088, USA. NR 38 TC 19 Z9 28 U1 0 U2 6 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0168-1923 J9 AGR FOREST METEOROL JI Agric. For. Meteorol. PD SEP PY 1994 VL 70 IS 1-4 BP 141 EP 152 DI 10.1016/0168-1923(94)90053-1 PG 12 WC Agronomy; Forestry; Meteorology & Atmospheric Sciences SC Agriculture; Forestry; Meteorology & Atmospheric Sciences GA PK499 UT WOS:A1994PK49900011 ER PT J AU HENDRIX, DL MAUNEY, JR KIMBALL, BA LEWIN, K NAGY, J HENDREY, GR AF HENDRIX, DL MAUNEY, JR KIMBALL, BA LEWIN, K NAGY, J HENDREY, GR TI INFLUENCE OF ELEVATED CO2 AND MILD WATER-STRESS ON NONSTRUCTURAL CARBOHYDRATES IN FIELD-GROWN COTTON TISSUES SO AGRICULTURAL AND FOREST METEOROLOGY LA English DT Article ID ATMOSPHERIC CO2; TUSSOCK TUNDRA; PLANT-GROWTH; TEMPERATURE; ENRICHMENT; EXPORT; YIELD; CO-2 AB Root, stem and leaf tissues, from cotton plants exposed to CO2 at ambient (370 mumol mol-1 (control)) or elevated (550 mumol mol-1 (FACE; free-air carbon dioxide enrichment)) levels in the field during the 1990 and 1991 growing seasons, were analyzed for nonstructural carbohydrates (glucose, fructose, sucrose and starch). Besides the FACE treatment, these plants were also exposed to two irrigation levels: 100% and 67% replacement of evapotranspiration. FACE had a greater effect upon cotton plant nonstructural carbohydrates than did irrigation treatments. Leaf carbohydrate content was increased by FACE, but this increase was much more pronounced in the stems and roots. Starch and soluble sugars in leaves in FACE plots tended to be consistently greater than in control leaves, without much change in carbohydrate content during the growing season. In contrast, root and stem, starch and soluble sugar pools were strongly increased by FACE and fluctuated strongly during the growing season. In both seasons, stem and taproot nonstructural carbohydrate content passed through a minimum during periods of heavy boll set. The fluctuations in stem and root carbohydrate content were therefore probably caused by the varying metabolic demands of the developing plant. These results suggest that a significant effect of CO2 enrichment on starch-accumulating plants is an increase of nonstructural carbohydrate, especially starch, in nonleaf storage pools. This buildup occurs somewhat independently of the water status of the plant, and these enlarged pools can be drawn upon by the growing plant to maintain growth during periods of high metabolic demand. C1 USDA ARS,WATER CONSERVAT LAB,PHOENIX,AZ 85040. BROOKHAVEN NATL LAB,DEPT APPL SCI,UPTON,NY 11973. RP HENDRIX, DL (reprint author), USDA ARS,WESTERN COTTON RES LAB,4135 E BROADWAY RD,PHOENIX,AZ 85040, USA. NR 18 TC 27 Z9 28 U1 1 U2 4 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0168-1923 J9 AGR FOREST METEOROL JI Agric. For. Meteorol. PD SEP PY 1994 VL 70 IS 1-4 BP 153 EP 162 DI 10.1016/0168-1923(94)90054-X PG 10 WC Agronomy; Forestry; Meteorology & Atmospheric Sciences SC Agriculture; Forestry; Meteorology & Atmospheric Sciences GA PK499 UT WOS:A1994PK49900012 ER PT J AU PINTER, PJ IDSO, SB HENDRIX, DL ROKEY, RR RAUSCHKOLB, RS MAUNEY, JR KIMBALL, BA HENDREY, GR LEWIN, KF NAGY, J AF PINTER, PJ IDSO, SB HENDRIX, DL ROKEY, RR RAUSCHKOLB, RS MAUNEY, JR KIMBALL, BA HENDREY, GR LEWIN, KF NAGY, J TI EFFECT OF FREE-AIR CO2 ENRICHMENT ON THE CHLOROPHYLL CONTENT OF COTTON LEAVES SO AGRICULTURAL AND FOREST METEOROLOGY LA English DT Article ID CARBON-DIOXIDE; PHOTOSYNTHETIC ACCLIMATION; EXTRACTABLE CHLOROPHYLL; LEAF GREENNESS; DRY-MATTER; NITROGEN; GROWTH; ROOT; DENSITY; PLANTS AB In vivo chlorophyll concentrations were estimated using a Minolta SPAD 502 meter on upper-canopy leaves of cotton plants exposed to air enriched to an atmospheric CO2 concentration of approximately 550 mumol mol-1 in a free-air CO2 enrichment (FACE) study. Measurements were made on 27 days during the final 90 days of the 1991 growing season. In both well-watered and moderately water-stressed plants, leaves in the FACE plots had greater chlorophyll a concentrations than leaves in the ambient air control plots (about 370 mumol CO2 mol-1): season-long chlorophyll a averages were 7.1% greater in the 'wet' treatment and 8.2% greater in the 'dry' treatment. This finding differs from what has been observed in a number of studies where experimental plants were grown in small pots. It is, however, typical of what has been observed in studies employing larger pots and open fields, and is a compelling rationale for conducting additional studies of this nature in FACE projects. C1 BROOKHAVEN NATL LAB,UPTON,NY 11973. UNIV ARIZONA,MARICOPA AGR CTR,MARICOPA,AZ 85239. RP PINTER, PJ (reprint author), USDA ARS,WATER CONSERVAT LAB,4331 E BROADWAY RD,PHOENIX,AZ 85040, USA. NR 28 TC 19 Z9 19 U1 0 U2 0 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0168-1923 J9 AGR FOREST METEOROL JI Agric. For. Meteorol. PD SEP PY 1994 VL 70 IS 1-4 BP 163 EP 169 DI 10.1016/0168-1923(94)90055-8 PG 7 WC Agronomy; Forestry; Meteorology & Atmospheric Sciences SC Agriculture; Forestry; Meteorology & Atmospheric Sciences GA PK499 UT WOS:A1994PK49900013 ER PT J AU BHATTACHARYA, NC RADIN, JW KIMBALL, BA MAUNEY, JR HENDREY, GR NAGY, J LEWIN, KF PONCE, DC AF BHATTACHARYA, NC RADIN, JW KIMBALL, BA MAUNEY, JR HENDREY, GR NAGY, J LEWIN, KF PONCE, DC TI LEAF WATER RELATIONS OF COTTON IN A FREE-AIR CO2-ENRICHED ENVIRONMENT SO AGRICULTURAL AND FOREST METEOROLOGY LA English DT Article ID CARBON-DIOXIDE ENRICHMENT; CO2 ENRICHMENT; GROWTH; STRESS; YIELD; PHOTOSYNTHESIS; SEEDLINGS; RESPONSES; CONDUCTANCE; PHOSPHORUS AB As part of an intensive study of crop response to CO2 enrichment in a free-air CO2 enrichment (FACE) experiment in the field, we determined aspects of the water relations of a cotton crop on selected dates in 1991. The atmosphere was enriched from 370 mumol CO2 mol-1 (control) to about 550 mumol mol-1 in free air during daylight hours. Under full irrigation, CO2 enrichment decreased stomatal conductance and single-leaf transpiration only toward the end of the season, and these changes led to increased leaf water potentials only at that time of year. Under water-stressed (deficit irrigation) conditions, CO2 enrichment decreased conductance throughout the season but there was no corresponding consistent effect on leaf water potentials. As with the fully irrigated controls, CO2 enrichment increased leaf water potentials only at the end of the season. CO2 enrichment increased season-long biomass accumulation 39% under full irrigation and 34% under deficit irrigation. These results are consistent with previous studies of cotton in open-top chambers that found only small effects of CO2 enrichment on internal water relations of cotton, and no water stress-induced increase in crop responsiveness to elevated CO2. C1 USDA ARS,WESTERN COTTON RES LAB,PHOENIX,AZ 85040. USDA ARS,US WATER CONSERVAT LAB,PHOENIX,AZ 85040. BROOKHAVEN NATL LAB,DEPT APPL SCI,UPTON,NY 11973. NR 34 TC 23 Z9 24 U1 1 U2 4 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0168-1923 J9 AGR FOREST METEOROL JI Agric. For. Meteorol. PD SEP PY 1994 VL 70 IS 1-4 BP 171 EP 182 DI 10.1016/0168-1923(94)90056-6 PG 12 WC Agronomy; Forestry; Meteorology & Atmospheric Sciences SC Agriculture; Forestry; Meteorology & Atmospheric Sciences GA PK499 UT WOS:A1994PK49900014 ER PT J AU IDSO, SB KIMBALL, BA WALL, GW GARCIA, RL LAMORTE, R PINTER, PJ MAUNEY, JR HENDREY, GR LEWIN, K NAGY, J AF IDSO, SB KIMBALL, BA WALL, GW GARCIA, RL LAMORTE, R PINTER, PJ MAUNEY, JR HENDREY, GR LEWIN, K NAGY, J TI EFFECTS OF FREE-AIR CO2 ENRICHMENT ON THE LIGHT RESPONSE CURVE OF NET PHOTOSYNTHESIS IN COTTON LEAVES SO AGRICULTURAL AND FOREST METEOROLOGY LA English DT Article ID CARBON-DIOXIDE; QUANTUM YIELD; TRANSPIRATION; GROWTH AB Daytime measurements of leaf CO2 exchange rates in a free-air CO2 enrichment (FACE) experiment reveal that at photosynthetically active radiation (PAR) flux rates in excess of 1000 mumol m-2 s-1, cotton leaves exposed to an atmospheric CO2 concentration of approximately 500 mumol mol-1 exhibit net photosynthetic rates about 30% greater than those for leaves of similar plants growing in ambient air. As PAR flux rates drop below this value, the stimulatory effect of elevated CO2 rises, suggesting that the relative benefits of atmospheric CO2 enrichment will be greater for shaded cotton leaves that for those exposed to full sunlight. C1 WESTERN COTTON RES LAB,PHOENIX,AZ 85040. BROOKHAVEN NATL LAB,UPTON,NY 11973. RP IDSO, SB (reprint author), US WATER CONSERVAT LAB,4331 E BROADWAY RD,PHOENIX,AZ 85040, USA. NR 18 TC 12 Z9 14 U1 2 U2 4 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0168-1923 J9 AGR FOREST METEOROL JI Agric. For. Meteorol. PD SEP PY 1994 VL 70 IS 1-4 BP 183 EP 188 DI 10.1016/0168-1923(94)90057-4 PG 6 WC Agronomy; Forestry; Meteorology & Atmospheric Sciences SC Agriculture; Forestry; Meteorology & Atmospheric Sciences GA PK499 UT WOS:A1994PK49900015 ER PT J AU HILEMAN, DR HULUKA, G KENJIGE, PK SINHA, N BHATTACHARYA, NC BISWAS, PK LEWIN, KF NAGY, J HENDREY, GR AF HILEMAN, DR HULUKA, G KENJIGE, PK SINHA, N BHATTACHARYA, NC BISWAS, PK LEWIN, KF NAGY, J HENDREY, GR TI CANOPY PHOTOSYNTHESIS AND TRANSPIRATION OF FIELD-GROWN COTTON EXPOSED TO FREE-AIR CO2 ENRICHMENT (FACE) AND DIFFERENTIAL IRRIGATION SO AGRICULTURAL AND FOREST METEOROLOGY LA English DT Article ID WATER-USE EFFICIENCY; CARBON-DIOXIDE; STOMATAL CONDUCTANCE; NITROGEN DEFICIENCY; ELEVATED CO2; LEAF; RESPONSES; STRESS; PLANTS; YIELD AB Growth, yield and leaf photosynthetic rates of cotton (Gossypium hirsutum L. ) all respond strongly to CO2 enrichment, but the gas exchange of whole cotton canopies grown under elevated CO2 has not been investigated. We compared the effects of CO2 enrichment on both single-leaf and whole-canopy photosynthetic rates in cotton. We also determined whole-canopy photosynthetic and transpiration rates in cotton in response to CO2 enrichment and differential irrigation. Field-grown cotton was exposed to either 550 mumol mol-1 of CO2 using the free-air carbon dioxide enrichment (FACE) system or to 370 mumol mol-1 in control plots. In the second year of the experiment, half of each plot received reduced levels of irrigation. Rates of photosynthesis and stomatal conductance of single leaves were determined using a portable photosynthesis system and a portable steady-state porometer, respectively. Rates of whole-canopy photosynthesis and transpiration were determined using a custom-built chamber (about 1 m x 1 m). Midday net photosynthesis rates of both leaves and canopies were 19-41% higher in the CO2-enriched plots than in control plots. The CO2 effect on leaf photosynthesis was greatest in July, whereas the CO2 effect on canopy photosynthesis was greatest in June and decreased thereafter as mutual shading of leaves and the amount of non-photosynthetic biomass increased. Midday stomatal conductance values of leaves were 13-44% greater in control plants than in CO2-enriched plants. Except for late in the second season, canopy transpiration rates were not affected by the CO2 treatment because the decrease in stomatal conductance was offset by an increase in plant size. Differential irrigation led to no significant differences in either canopy photosynthesis or transpiration, possibly because differential irrigation was applied only during the second half of the season. It appears that cotton crops grown in a future, higher-CO2 climate may have increased photosynthetic rates, but water requirements may not be reduced. C1 BROOKHAVEN NATL LAB,DEPT APPL SCI,UPTON,NY 11973. TUSKEGEE UNIV,DEPT AGR SCI,TUSKEGEE,AL 36088. RP HILEMAN, DR (reprint author), TUSKEGEE UNIV,DEPT BIOL,TUSKEGEE,AL 36088, USA. NR 51 TC 38 Z9 47 U1 6 U2 17 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0168-1923 J9 AGR FOREST METEOROL JI Agric. For. Meteorol. PD SEP PY 1994 VL 70 IS 1-4 BP 189 EP 207 DI 10.1016/0168-1923(94)90058-2 PG 19 WC Agronomy; Forestry; Meteorology & Atmospheric Sciences SC Agriculture; Forestry; Meteorology & Atmospheric Sciences GA PK499 UT WOS:A1994PK49900016 ER PT J AU PINTER, PJ KIMBALL, BA MAUNEY, JR HENDREY, GR LEWIN, KF NAGY, J AF PINTER, PJ KIMBALL, BA MAUNEY, JR HENDREY, GR LEWIN, KF NAGY, J TI EFFECTS OF FREE-AIR CARBON-DIOXIDE ENRICHMENT ON PAR ABSORPTION AND CONVERSION EFFICIENCY BY COTTON SO AGRICULTURAL AND FOREST METEOROLOGY LA English DT Article ID PHOTOSYNTHETICALLY ACTIVE RADIATION; VEGETATION INDEXES; SOLAR-RADIATION; CANOPY REFLECTANCE; CORN CANOPIES; WINTER-WHEAT; GROWTH; CO2; FIELD; YIELD AB Anticipated changes in global climate and atmospheric CO2 concentrations have very important, albeit poorly understood consequences for production agriculture. Effects of these changes on plants have usually been examined in controlled-environment enclosures, glass-houses, or open-top field chambers. Beginning in 1989, an innovative experimental free-air CO2 enrichment (FACE) facility was operated in central Arizona to evaluate crop response to increased CO2 levels within a large, open-field production environment. Cotton (Gossypium hirsutum L.) was grown for three consecutive seasons under exposed to either ambient (control, about 370 mumol mol-1) or elevated (FACE, 550 mumol mol-1) CO2 concentrations. Deficit irrigation regimes supplying 75% (beginning in July 1990) or 67% (beginning in mid-May 1991) of the crop's evapotranspiration requirement were included as additional treatment variables. Plant growth was monitored by periodic sampling. Canopy reflectances in visible (blue, 0.45-0.52 mum; green, 0.05-0.59 mum; red, 0.61-0.68 mum) and near-infrared (NIR; 0.79-0.89 mum) wavebands were measured frequently with an Exotech radiometer and related to absorbed photosynthetically active radiation (PAR; 0.4-0.7 mum) measured with a line quantum sensor. Dry biomass of plants in the FACE treatment was significantly (P < 0.05) greater than control values during each year of the study. The FACE plant canopy also absorbed significantly more PAR than controls during the early and middle portion of the 1990 and 1991 seasons. Light use efficiency (LUE, biomass produced per unit absorbed PAR) was significantly higher in FACE plots during each year. In the well-watered irrigation treatment, the 3 year mean LUE was 1.97 g MJ-1 for FACE and 1.56 g MJ-1 for controls. The deficit irrigation treatment in 1991 produced significantly smaller plants, which absorbed less PAR and had lower LUE than plants in the well-watered treatment (P < 0.05). No interaction was observed between CO2 and irrigation treatments. FACE research under realistic field conditions revealed positive consequences of increased CO2 on cotton plant biomass, PAR absorption, and LUE. It also demonstrated the effectiveness of this new technology for examining community-level plant responses to possible changes in global environment. C1 WESTERN COTTON RES LAB,PHOENIX,AZ 85040. BROOKHAVEN NATL LAB,UPTON,NY 11973. RP PINTER, PJ (reprint author), US WATER CONSERVAT LAB,4331 E BROADWAY RD,PHOENIX,AZ 85040, USA. NR 47 TC 38 Z9 38 U1 0 U2 3 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0168-1923 J9 AGR FOREST METEOROL JI Agric. For. Meteorol. PD SEP PY 1994 VL 70 IS 1-4 BP 209 EP 230 DI 10.1016/0168-1923(94)90059-0 PG 22 WC Agronomy; Forestry; Meteorology & Atmospheric Sciences SC Agriculture; Forestry; Meteorology & Atmospheric Sciences GA PK499 UT WOS:A1994PK49900017 ER PT J AU DUGAS, WA HEUER, ML HUNSAKER, D KIMBALL, BA LEWIN, KF NAGY, J JOHNSON, M AF DUGAS, WA HEUER, ML HUNSAKER, D KIMBALL, BA LEWIN, KF NAGY, J JOHNSON, M TI SAP FLOW MEASUREMENTS OF TRANSPIRATION FROM COTTON GROWN UNDER AMBIENT AND ENRICHED CO2 CONCENTRATIONS SO AGRICULTURAL AND FOREST METEOROLOGY LA English DT Article ID CARBON-DIOXIDE; WATER-USE; HEAT-BALANCE; STEM-FLOW; LEAF CONDUCTANCE; ELEVATED CO2; CROP YIELD; MASS-FLOW; EVAPORATION; PLANTS AB Increasing atmospheric CO2 concentration has many implications for agriculture and forestry, one of which is the effect it will have on transpiration (T). The objective of this work was to quantify T of cotton (Gossypium hirsutum L.) grown in the field under ambient (370 mumol mol-1) and enriched (550 mumol mol-1) CO2 concentrations. Measurements were made in 1990 and 1991 at the Maricopa Agricultural Center, Arizona. Constant-power sap flow gauges were used to measure T. In 1990, three plants and in 1991, 10 plants were simultaneously instrumented with gauges in each of the CO2 treatments. Leaf area of plants with gauges was measured. T measured by sap flow was compared with evapotranspiration (ET) calculated by water balance in 1990 and with T calculated by water balance in 1991. Soil evaporation was measured using microlysimeters in 1991, and was found to be essentially equal (approximately 0.8 mm day-1, or about 10% of T) in the two CO2 treatments. There were no consistent differences in leaf area of plants with gauges between the two CO2 treatments. Sap flow, for periods from 15 min to 2 weeks, was not significantly different between the two CO2 treatments in either year, except for a few days in 1990. In 1991, the coefficient of variation of daily sap flow across plants was the same (about 30%) for both CO2 treatments throughout the year. The water balance ET (1990) and T (1991) were similar to sap flow in both years, and also showed no effect of CO2 treatment. These results show that for this crop, grown under well-watered and high-fertility conditions, there was no effect of CO2 on T, on a per unit ground area or per plant basis. These results are relevant for assessing the effects of increasing atmospheric CO2 concentrations on transpiration by cotton. C1 USDA ARS,US WATER CONSERVAT LAB,PHOENIX,AZ 85040. BROOKHAVEN NATL LAB,DEPT APPL SCI,UPTON,NY 11973. RP DUGAS, WA (reprint author), TEXAS AGR EXPTL STN,BLACKLAND RES CTR,808 E BLACKLAND RD,TEMPLE,TX 76502, USA. NR 47 TC 46 Z9 52 U1 0 U2 8 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0168-1923 J9 AGR FOREST METEOROL JI Agric. For. Meteorol. PD SEP PY 1994 VL 70 IS 1-4 BP 231 EP 245 DI 10.1016/0168-1923(94)90060-4 PG 15 WC Agronomy; Forestry; Meteorology & Atmospheric Sciences SC Agriculture; Forestry; Meteorology & Atmospheric Sciences GA PK499 UT WOS:A1994PK49900018 ER PT J AU HUNSAKER, DJ HENDREY, GR KIMBALL, BA LEWIN, KF MAUNEY, JR NAGY, J AF HUNSAKER, DJ HENDREY, GR KIMBALL, BA LEWIN, KF MAUNEY, JR NAGY, J TI COTTON EVAPOTRANSPIRATION UNDER FIELD CONDITIONS WITH CO2 ENRICHMENT AND VARIABLE SOIL-MOISTURE REGIMES SO AGRICULTURAL AND FOREST METEOROLOGY LA English DT Article ID CARBON-DIOXIDE; WATER-USE; YIELD AB The CO2 concentration of the atmosphere is predicted to double by the next century, and this is expected to increase significantly the growth and yield of many important agricultural crops. One consequence of larger and more vigorous plants may be increased crop evapotranspiration (ET) and irrigation water requirements. The objective of this work was to determine ET of cotton (Gossypium hirsutum L. cv. 'Deltapine 77') grown under ambient (about 370 mumol mol-1) and enriched (550 mumol mol-1) CO2 concentrations for both well-watered and water-stress irrigation managements. Studies were conducted in 1990 and 1991 within a large, drip-irrigated cotton field in central Arizona. Cotton ET was measured during the growing seasons using a soil water balance, based on neutron gauge soil water measurements. ET, for periods from 7 to 14 days, was not significantly different between ambient and enriched CO2 treatments at the 0.05 probability level, and the total seasonal ET for the CO2 treatments varied by 2% or less in either year. However, water-stress treatments, which were initiated on 3 July (day of year (DOY) 184) in 1990 and on 20 May (DOY 128) in 1991, had significantly lower (P < 0.05) ET than well-watered treatments starting at the end of July in 1990 and in early July in 1991 when the plants were about 75-90 days old. The result that CO2 enrichment to 550 mumol mol-1 did not significantly change the ET of cotton was consistent with the results of co-investigators who measured ET in the same experiments using stem flow gauges and an energy balance. This result implies that irrigation water use would not have to be increased to produce cotton in a future high-CO2 world. However, if a concomitant change in climate occurs, such as global warming, cotton evapotranspiration may change in response to the changed weather condition. C1 USDA ARS,WESTERN COTTON RES LAB,PHOENIX,AZ 85040. BROOKHAVEN NATL LAB,DEPT APPL SCI,UPTON,NY 11973. RP HUNSAKER, DJ (reprint author), USDA ARS,US WATER CONSERVAT LAB,4331 E BROADWAY RD,PHOENIX,AZ 85040, USA. NR 28 TC 49 Z9 57 U1 1 U2 5 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0168-1923 J9 AGR FOREST METEOROL JI Agric. For. Meteorol. PD SEP PY 1994 VL 70 IS 1-4 BP 247 EP 258 DI 10.1016/0168-1923(94)90061-2 PG 12 WC Agronomy; Forestry; Meteorology & Atmospheric Sciences SC Agriculture; Forestry; Meteorology & Atmospheric Sciences GA PK499 UT WOS:A1994PK49900019 ER PT J AU KIMBALL, BA LAMORTE, RL SEAY, RS PINTER, PJ ROKEY, RR HUNSAKER, DJ DUGAS, WA HEUER, ML MAUNEY, JR HENDREY, GR LEWIN, KF NAGY, J AF KIMBALL, BA LAMORTE, RL SEAY, RS PINTER, PJ ROKEY, RR HUNSAKER, DJ DUGAS, WA HEUER, ML MAUNEY, JR HENDREY, GR LEWIN, KF NAGY, J TI EFFECTS OF FREE-AIR CO2 ENRICHMENT ON ENERGY-BALANCE AND EVAPOTRANSPIRATION OF COTTON SO AGRICULTURAL AND FOREST METEOROLOGY LA English DT Article ID RADIATIVE SURFACE-TEMPERATURE; INCREASING ATMOSPHERIC CO2; WATER-USE; CARBON-DIOXIDE; WHEAT CANOPY; LATENT-HEAT; CROP YIELD; EVAPORATION AB The effects of free-air CO2 enrichment (FACE) at 550 mumol mol-1 on the energy balance and evapotranspiration, ET, of cotton (Gossypium hirsutum L.) were investigated. Latent heat flux, lambdaET, was calculated as the residual in an energy balance approach from determinations of net radiation, R(n), minus surface soil heat flux, G0, minus sensible heat flux, H. R(n) was directly measured. G0 was determined from measurements with soil heat flux plates at 10 mm depth, corrected for temperature changes in the soil above. H was determined from measurements of air temperature with aspirated psychrometers, of foliage temperature with IR thermometers, and of wind speed with cup anemometers. Under ambient CO2 (control) conditions (about 370 mumol mol-1), the lambdaET from the energy balance approach agreed fairly well with values from several other methods, including the Bowen ratio method, lending credence to the technique. However, the results had an uncertainty of the order of 20% associated with the R(n) measurements. Therefore, an apparent increase in ET of about 13% in the FACE plots was judged insignificant. The conclusion that any effects of CO2 enrichment to 550 mumol mol-1 on the ET of cotton were too small to be detected was consistent with the results of other investigators who determined ET in the same experiment using stem flow gauges and the soil water balance. C1 TEXAS AGR EXPTL STN,BLACKLAND RES CTR,TEMPLE,TX 76502. USDA ARS,WESTERN COTTON RES LAB,PHOENIX,AZ 85040. BROOKHAVEN NATL LAB,DEPT APPL SCI,UPTON,NY 11973. RP KIMBALL, BA (reprint author), USDA ARS,US WATER CONSERVAT LAB,4331 E BROADWAY RD,PHOENIX,AZ 85040, USA. NR 34 TC 67 Z9 87 U1 2 U2 6 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0168-1923 J9 AGR FOREST METEOROL JI Agric. For. Meteorol. PD SEP PY 1994 VL 70 IS 1-4 BP 259 EP 278 DI 10.1016/0168-1923(94)90062-0 PG 20 WC Agronomy; Forestry; Meteorology & Atmospheric Sciences SC Agriculture; Forestry; Meteorology & Atmospheric Sciences GA PK499 UT WOS:A1994PK49900020 ER PT J AU AKIN, DE KIMBALL, BA MAUNEY, JR LAMORTE, RL HENDREY, GR LEWIN, K NAGY, J GATES, RN AF AKIN, DE KIMBALL, BA MAUNEY, JR LAMORTE, RL HENDREY, GR LEWIN, K NAGY, J GATES, RN TI INFLUENCE OF ENHANCED CO2 CONCENTRATION AND IRRIGATION ON SUDANGRASS DIGESTIBILITY SO AGRICULTURAL AND FOREST METEOROLOGY LA English DT Article ID CARBON-DIOXIDE; ENRICHMENT AB An experimental line of sudangrass (Sorghum bicolor L. Moench) was included in the free-air CO2 enrichment (FACE) project in 1991 at the University of Arizona Maricopa Agricultural Center to evaluate the effect of ambient (approximately 370 mumol mol-1) and enriched (550 mumol mol-1) CO2 in well-watered or water-stressed plots. Our specific objective was to determine modifications caused by these environmental effects on the percentages of morphological parts and the fiber components, and on the in vitro digestibility in vegetative and mature harvests. Enrichment with CO2 did not (P > 0.05) change the percentages of morphological parts or fiber components, or the digestibility of any of the morphological components. Protein levels tended to be lower in CO2-enriched plants. However, water-stressed plants tended to have a higher proportion of leaves (blades and sheaths) and a lower proportion of stems, were more digestible, and had lower amounts of anti-quality, aromatic compounds within the plant cell. Stems had the highest digestibility of all morphological components (about 75% in vegetative plants) despite the lowest levels of protein. Stems also showed the greatest changes caused by all treatments, including a 20% decline in digestibility from vegetative to mature samples. The results indicate that enriching CO2 to 550 mumol mol-1 did not reduce digestibility of sudangrass. C1 USDA ARS, US WATER CONSERVAT LAB, PHOENIX, AZ 85040 USA. USDA ARS, WESTERN COTTON RES LAB, PHOENIX, AZ 85040 USA. BROOKHAVEN NATL LAB, UPTON, NY 11973 USA. USDA ARS, COASTAL PLAIN EXPT STN, TIFTON, GA 31794 USA. RP USDA ARS, RICHARD B RUSSELL AGR RES CTR, POB 5677, ATHENS, GA 30613 USA. NR 25 TC 15 Z9 15 U1 0 U2 1 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0168-1923 EI 1873-2240 J9 AGR FOREST METEOROL JI Agric. For. Meteorol. PD SEP PY 1994 VL 70 IS 1-4 BP 279 EP 287 DI 10.1016/0168-1923(94)90063-9 PG 9 WC Agronomy; Forestry; Meteorology & Atmospheric Sciences SC Agriculture; Forestry; Meteorology & Atmospheric Sciences GA PK499 UT WOS:A1994PK49900021 ER PT J AU SCHEFER, RW NAMAZIAN, M KELLY, J AF SCHEFER, RW NAMAZIAN, M KELLY, J TI VELOCITY-MEASUREMENTS IN TURBULENT BLUFF-BODY STABILIZED FLOWS SO AIAA JOURNAL LA English DT Article ID FLAME AB Velocity measurements have been obtained in a turbulent bluff-body stabilized flow. The flow configuration consisted of a 5.4-mm-diam methane jet separated from an outer, annular air flow by a 50-mm-diam bluff body. Results were obtained for three fuel-jet to outer air velocity ratios to study the effects of inlet velocity ratio on the turbulence and flowfield characteristics. At low inlet velocity ratios the flow can best be described as dominated by the reverse flow of the annular air stream and exhibits well-defined fuel jet and annular air stagnation points along the centerline. As the velocity ratio is increased, fuel-jet penetration increases until the dynamic pressure of the jet is sufficient to overcome the adverse pressure gradient of the outer air, and the fuel jet penetrates the recirculation zone. Under these conditions the stagnation points move off the centerline, and the flow is best described as dominated by the fuel jet. Probability distributions of individual velocity components are bimodal in regions of high shear located along the recirculation zone boundaries and in downstream stagnation zones. Conditional seeding of the central jet and annular air shows that the two modes of the bimodal distributions are associated with the alternate passage of unmixed fuel and air through the measurement volume. The observed data are interpreted in terms of instantaneous Mie scattering pictures, which emphasize the importance of large-scale structure and intermittency in these flows. C1 ALTEX TECHNOL CORP,SANTA CLARA,CA 95054. RP SCHEFER, RW (reprint author), SANDIA NATL LABS,COMBUST RES FACIL,LIVERMORE,CA 94550, USA. RI Schefer, Jurg/G-3960-2012 NR 11 TC 36 Z9 36 U1 0 U2 3 PU AMER INST AERONAUT ASTRONAUT PI RESTON PA 1801 ALEXANDER BELL DRIVE, STE 500, RESTON, VA 22091 SN 0001-1452 J9 AIAA J JI AIAA J. PD SEP PY 1994 VL 32 IS 9 BP 1844 EP 1851 DI 10.2514/3.12182 PG 8 WC Engineering, Aerospace SC Engineering GA PF092 UT WOS:A1994PF09200012 ER PT J AU TUFILLARO, NB AF TUFILLARO, NB TI A GENERATION LOST - COMMENT SO AMERICAN JOURNAL OF PHYSICS LA English DT Editorial Material RP TUFILLARO, NB (reprint author), LOS ALAMOS NATL LAB,LOS ALAMOS,NM 87545, USA. NR 8 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 0002-9505 J9 AM J PHYS JI Am. J. Phys. PD SEP PY 1994 VL 62 IS 9 BP 777 EP 778 DI 10.1119/1.17458 PG 2 WC Education, Scientific Disciplines; Physics, Multidisciplinary SC Education & Educational Research; Physics GA PD725 UT WOS:A1994PD72500006 ER PT J AU FARGES, F BROWN, GE VELDE, D AF FARGES, F BROWN, GE VELDE, D TI STRUCTURAL ENVIRONMENT OF ZR IN 2 INOSILICATES FROM CAMEROON - MINERALOGICAL AND GEOCHEMICAL IMPLICATIONS SO AMERICAN MINERALOGIST LA English DT Article ID IGALIKO DYKE SWARM; SOUTH GREENLAND; TRACE-ELEMENT; PARTITION-COEFFICIENTS; ZIRCON SATURATION; PYROXENES; LIQUIDS; ROCKS; NB; NOMENCLATURE AB The structural environments of Zr in a Na- and Fe2+-rich clinopyroxene and an arfvedsonitic amphibole (both with 1-2 wt% ZrO2) from a phonolite of the Rumpi Hills volcanic complex, west Cameroon, were examined using X-ray absorption fine-structure (XAFS) spectroscopy at the ZrK edge. In the clinopyroxene, tetravalent Zr is coordinated by six O atoms. Mean d[Zr-O] almost-equal-to 2.07(1) angstrom; second neighbors around Zr include (Si,Na) and Fe at almost-equal-to 3.16-3.18(5) angstrom. No evidence was found for Zr second neighbors. These observations are consistent with the presence of Zr in the M1 site. This structural arrangement leads to local bond valence satisfaction and supports the mechanism for Zr substitution in inosilicates suggested by Jones and Peckett (1980). Similarities in the XANES and XAFS spectra of clinopyroxene and arfvedsonite suggest that Zr is located in the M2 site in arfvedsonite, with mean d[Zr-O] almost-equal-to 2.04(4) angstrom. The local environment of Zr in these Na- and Fe2+-rich inosilicates is like that observed in Zr-bearing garnets and Zr-bearing silicate glasses, in which [6]Zr is favored by the presence of nonbridging O atoms, to which Zr preferentially bonds. The similarity of the short-range structural environment of Zr in silicate melts and in [6]Zr-, Na-, and Fe2+-bearing inosilicates may explain why this normally incompatible trace element behaved compatibly during the crystallization of the phonolites of the Rumpi Hills volcanic complex, in which Na- and Fe2+-rich inosilicates are found. Simple bond valence arguments are used to explain why increases in the Fe3+-Fe(tot) ratio during later stages of differentiation of the Rumpi Hills peralkaline melt should favor the incompatible behavior of Zr. C1 STANFORD UNIV,DEPT GEOL & ENVIRONM SCI,STANFORD,CA 94305. STANFORD UNIV,STANFORD SYNCHROTRON RADIAT LAB,STANFORD,CA 94305. UNIV PARIS 06,PETROL MINERAL LAB,F-75252 PARIS 05,FRANCE. NR 52 TC 28 Z9 28 U1 0 U2 3 PU MINERALOGICAL SOC AMER PI WASHINGTON PA 1130 17TH ST NW SUITE 330, WASHINGTON, DC 20036 SN 0003-004X J9 AM MINERAL JI Am. Miner. PD SEP-OCT PY 1994 VL 79 IS 9-10 BP 838 EP 847 PG 10 WC Geochemistry & Geophysics; Mineralogy SC Geochemistry & Geophysics; Mineralogy GA PM159 UT WOS:A1994PM15900005 ER PT J AU SPIEGEL, DR CALAWAY, WF CURLEE, GA DAVIS, AM LEWIS, RS PELLIN, MJ GRUEN, DM CLAYTON, RN AF SPIEGEL, DR CALAWAY, WF CURLEE, GA DAVIS, AM LEWIS, RS PELLIN, MJ GRUEN, DM CLAYTON, RN TI 3-COLOR AND 1+1-RESONANCE IONIZATION MASS-SPECTROMETRY OF ZIRCONIUM SPUTTERED FROM REFRACTORY CARBIDES SO ANALYTICAL CHEMISTRY LA English DT Article ID INTERSTELLAR GRAINS; LASER FLUORESCENCE; ISOTOPE RATIOS; ATOMS; SPECTROSCOPY; SELECTIVITY; METEORITES; OSMIUM; DISTRIBUTIONS; SENSITIVITY AB Although resonance ionization mass spectrometry (RIMS) has proved a powerful tool in trace analyses of pure elemental materials, much less attention has been given to refractory multicomponent materials of interest in many geochemical applications. As preparation for analyses of minor amounts of Zr in refractory carbide interstellar grains, we have detected zirconium atoms sputtered from Zr metal and a ZrC powder, using both 1 + 1 and three-color RIMS. The two spectroscopic schemes were quantitatively evaluated for studies of chemically complex samples via (1) matrix sensitivity measurements, in which the Zr resonance signals obtained from ZrC and Zr metal under identical experimental conditions were compared; (2) measurement of the resonant enhancement of Zr sputtered from ZrC, relative to (isobarically interfering) Mo and Ti-2 sputtered from Mo2C and TiC samples, respectively; and (3) for the three-color study, measurement of the saturation curves for the individual Zr isotopes for each of the laser wavelengths employed. No Ti-2 signal was observed above the analog noise level for either scheme. The three-color ionization is easily saturated and yields a Zr/Mo selectivity of 3600 +/- 1400. An odd-even Zr isotope effect was clearly evident in a comparison of the measured off- and on-resonance Zr-91 abundance. The results here should prove useful in quantitative RIMS analyses of compound refractory matrices and in the assessment of the potential for RIMS in studies of interstellar carbide grains. C1 ARGONNE NATL LAB,DIV CHEM TECHNOL,ARGONNE,IL 60439. UNIV CHICAGO,ENRICO FERMI INST,CHICAGO,IL 60637. ARGONNE NATL LAB,DIV CHEM,ARGONNE,IL 60439. ARGONNE NATL LAB,DIV MAT SCI,ARGONNE,IL 60439. RP SPIEGEL, DR (reprint author), TRINITY UNIV,DEPT PHYS,SAN ANTONIO,TX 78212, USA. RI Pellin, Michael/B-5897-2008 OI Pellin, Michael/0000-0002-8149-9768 NR 42 TC 7 Z9 7 U1 1 U2 2 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 SN 0003-2700 J9 ANAL CHEM JI Anal. Chem. PD SEP 1 PY 1994 VL 66 IS 17 BP 2647 EP 2655 DI 10.1021/ac00089a010 PG 9 WC Chemistry, Analytical SC Chemistry GA PD717 UT WOS:A1994PD71700012 ER PT J AU FORNSTEDT, T GUIOCHON, G AF FORNSTEDT, T GUIOCHON, G TI COMPARISON BETWEEN EXPERIMENTAL AND THEORETICAL PROFILES OF HIGH-CONCENTRATION ELUTION BANDS AND LARGE SYSTEM PEAKS IN NONLINEAR CHROMATOGRAPHY SO ANALYTICAL CHEMISTRY LA English DT Article ID PAIR ADSORPTION CHROMATOGRAPHY; PERFORMANCE LIQUID-CHROMATOGRAPHY; QUATERNARY AMMONIUM ION; BINARY ELUENT; MOBILE PHASE; COMPRESSION; RETENTION; OPTIMIZATION; REMOXIPRIDE; BIOANALYSIS AB A detailed experimental investigation of the profiles of system peaks and single solute bands at high concentrations was conducted under experimental conditions leading to severe interference between the primary additive system peak and the additive system peak associated with the solute band. These conditions trigger the formation of extremely unusual band shapes. Both additive and solute individual profiles have been recorded separately, using a diode-array detector operating at different wavelengths selected for the selectivity of the response to the two different compounds. The profiles recorded are in very good agreement with the profiles calculated from the isotherms of the two compounds, using the equilibrium-dispersive model of chromatography. This result confirms that major distortions of band profiles occur whenever the additive is more strongly adsorbed than the solute by the stationary phase, but its concentration in the mobile phase is high enough for the additive primary system peak to be eluted before the solute peak, with a separation factor close to unity. Although the experiments were carried out using a reversed-phase ion-pair chromatographic system, the same phenomenon has been shown to occur in normal-phase adsorption chromatography as well. Important band deformation, corresponding to the passage from a Langmuirian to an anti-Langmuirian band profile when the sample size is increased may easily take place when these modes of chromatography are used for preparative applications, explaining a certain disfavor among users. Guidelines are suggested to avoid or control these phenomena whose consequences may not be always as disastrous as felt at first glance. C1 UNIV TENNESSEE,DEPT CHEM,KNOXVILLE,TN 37996. OAK RIDGE NATL LAB,DIV ANALYT CHEM,OAK RIDGE,TN 37831. OI Fornstedt, Torgny/0000-0002-7123-2066 NR 36 TC 37 Z9 37 U1 0 U2 8 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 SN 0003-2700 J9 ANAL CHEM JI Anal. Chem. PD SEP 1 PY 1994 VL 66 IS 17 BP 2686 EP 2693 DI 10.1021/ac00089a015 PG 8 WC Chemistry, Analytical SC Chemistry GA PD717 UT WOS:A1994PD71700017 ER PT J AU FIRESTONE, LL QUINLAN, JJ HOMANICS, G FIRESTONE, S WINTER, PM RUSSELL, LB FINCHIK, EM AF FIRESTONE, LL QUINLAN, JJ HOMANICS, G FIRESTONE, S WINTER, PM RUSSELL, LB FINCHIK, EM TI HALOTHANE RESPONSES IN MICE WITH DELETION OF THE GENES ENCODING FOR GABA(A) RECEPTOR SUBUNIT-ALPHA(5) AND SUBUNIT-GAMMA(3) SO ANESTHESIOLOGY LA English DT Meeting Abstract C1 UNIV PITTSBURGH,DEPT ANASTHESIOL,PITTSBURGH,PA 15261. UNIV PITTSBURGH,DEPT CRIT CARE MED,PITTSBURGH,PA 15261. OAK RIDGE NATL LAB,DEPT BIOL,OAK RIDGE,TN 37831. NR 16 TC 1 Z9 1 U1 0 U2 0 PU LIPPINCOTT-RAVEN PUBL PI PHILADELPHIA PA 227 EAST WASHINGTON SQ, PHILADELPHIA, PA 19106 SN 0003-3022 J9 ANESTHESIOLOGY JI Anesthesiology PD SEP PY 1994 VL 81 IS 3A SU S BP A861 EP A861 PG 1 WC Anesthesiology SC Anesthesiology GA PJ091 UT WOS:A1994PJ09100860 ER PT J AU ABDALLA, MA AF ABDALLA, MA TI A 4-REGION, MOVING-BOUNDARY MODEL OF A ONCE-THROUGH, HELICAL-COIL STEAM-GENERATOR SO ANNALS OF NUCLEAR ENERGY LA English DT Article AB A dynamic model of a once-through, helical-coil steam generator is presented. The model simulates the advanced liquid metal reactor superheated cycle steam generator with a four-region, moving-boundary, draft-flux flow model. The model is described by a set of nonlinear differential equations derived from the fundamental equations of conservation of mass, energy, and momentum. Sample results of steady-state and transient calculations are presented. RP ABDALLA, MA (reprint author), OAK RIDGE ASSOCIATED UNIV,POB 117,OAK RIDGE,TN 37831, USA. NR 12 TC 16 Z9 18 U1 0 U2 2 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD, ENGLAND OX5 1GB SN 0306-4549 J9 ANN NUCL ENERGY JI Ann. Nucl. Energy PD SEP PY 1994 VL 21 IS 9 BP 541 EP 562 DI 10.1016/0306-4549(94)90078-7 PG 22 WC Nuclear Science & Technology SC Nuclear Science & Technology GA PD318 UT WOS:A1994PD31800004 ER PT J AU ANDERSON, KM SEED, T ONDREY, F HARRIS, JE AF ANDERSON, KM SEED, T ONDREY, F HARRIS, JE TI THE SELECTIVE 5-LIPOXYGENASE INHIBITOR A63162 REDUCES PC3 PROLIFERATION AND INITIATES MORPHOLOGIC CHANGES CONSISTENT WITH SECRETION SO ANTICANCER RESEARCH LA English DT Article DE 5-LIPOXYGENASE; A63162; PC3 PROLIFERATION; SECRETION ID ARACHIDONIC-ACID METABOLISM; PROTEIN KINASE-C; SIGNAL TRANSDUCTION; PROSTATE-CANCER; DNA-SYNTHESIS; CARCINOMA-CELLS; GROWTH-FACTORS; FATTY-ACIDS; PRODUCTS; PATHWAY AB We examined the effect of A63162 (Abbott), a selective inhibitor of 5-lipoxygenase on human prostate (PC3) cell proliferation. Within 5 min DNA synthesis was reversibly inhibited by 40 mu M A63162, without altered cellular attachment or uptake of trypan blue. After 72 Hr, cells continued to be attached and exclude dye, were reduced in number and their histology was altered. Many treated cells were larger, more pleomorphic, with nuclear and cytoplasmic ultrastructural changes consistent with preparation for secretion. Some cells contained moderately swollen, distorted mitochondria. ETYA, a less selective inhibitor of 5-lipoxygenase that also inhibits cell replication, acutely reduced O-2 uptake by 40%, but A63162 did not. The retention of the supravital mitochondrial dye, rhodamine 123 was increased by ETYA at 4 hr, but not after 24 hr; retention was not altered by A63162. Although the mechanism by which A63162 reversibly inhibits PC3 proliferation and initiates preparation for secretion is not identified, additional studies should further define its role in these events. C1 RUSH MED COLL, DEPT BIOCHEM, CHICAGO, IL 60612 USA. ARGONNE NATL LAB, DIV BIOL & MED RES, ARGONNE, IL 60439 USA. UNIV MINNESOTA, DEPT OTOLARYNGOL, MINNEAPOLIS, MN 55455 USA. RP ANDERSON, KM (reprint author), RUSH MED COLL, DEPT MED, MED ONCOL SECT, CHICAGO, IL 60612 USA. NR 42 TC 13 Z9 13 U1 0 U2 1 PU INT INST ANTICANCER RESEARCH PI ATHENS PA EDITORIAL OFFICE 1ST KM KAPANDRITIOU-KALAMOU RD KAPANDRITI, PO BOX 22, ATHENS 19014, GREECE SN 0250-7005 J9 ANTICANCER RES JI Anticancer Res. PD SEP-OCT PY 1994 VL 14 IS 5A BP 1951 EP 1960 PG 10 WC Oncology SC Oncology GA QE791 UT WOS:A1994QE79100040 PM 7847833 ER PT J AU JELLISON, GE BOATNER, LA LOWNDES, DH MCKEE, RA GODBOLE, M AF JELLISON, GE BOATNER, LA LOWNDES, DH MCKEE, RA GODBOLE, M TI OPTICAL FUNCTIONS AND TRANSPARENT THIN-FILMS OF SRTIO3, BATIO3, AND SIOX DETERMINED BY SPECTROSCOPIC ELLIPSOMETRY SO APPLIED OPTICS LA English DT Article ID POLARIZATION MODULATION ELLIPSOMETRY; REFRACTIVE-INDEX; DEPTH-PROFILE; DISPERSION; GAAS; CONSTANTS; SILICON; OXIDE; GAP; ZNS AB A procedure is presented for accurately determining the thickness, optical functions, and surface-roughness characteristics of thin-film insulators from two-channel spectroscopic polarization-modulation ellipsometry data. For films with minimal surface roughness, the optical functions can be determined over the entire measured spectrum; for rougher films, the analysis of the spectroscopic ellipsometry data yields meaningful values of the optical functions only in the transparent region. In general, the films must be transparent in a given range of wavelengths sampled by the ellipsometer so that at least two interference oscillations can be observed. The use of the procedure is illustrated with the determination of the optical functions of SrTiO3 and BaTiO3 thin films grown on MgO, and of SiO(x) films grown on Si. For SrTiO3 and BaTiO3, the thin-film results are compared with the measured optical functions of the respective bulk materials. C1 UNIV TENNESSEE, KNOXVILLE, TN 37996 USA. OAK RIDGE NATL LAB, DIV MET & CERAM, OAK RIDGE, TN 37831 USA. RP JELLISON, GE (reprint author), OAK RIDGE NATL LAB, DIV SOLID STATE, POB 2008, OAK RIDGE, TN 37831 USA. RI Boatner, Lynn/I-6428-2013 OI Boatner, Lynn/0000-0002-0235-7594 NR 23 TC 53 Z9 53 U1 2 U2 18 PU OPTICAL SOC AMER PI WASHINGTON PA 2010 MASSACHUSETTS AVE NW, WASHINGTON, DC 20036 USA SN 0003-6935 J9 APPL OPTICS JI Appl. Optics PD SEP 1 PY 1994 VL 33 IS 25 BP 6053 EP 6058 PG 6 WC Optics SC Optics GA PF320 UT WOS:A1994PF32000032 PM 20936019 ER PT J AU STUMP, NA CHEN, G HAIRE, RG PETERSON, JR AF STUMP, NA CHEN, G HAIRE, RG PETERSON, JR TI TEMPERATURE-DEPENDENCE OF THE EU3+ ION LUMINESCENCE LIFETIME EXHIBITED BY ANHYDROUS EUCL3 SO APPLIED SPECTROSCOPY LA English DT Note DE ANHYDROUS EUCL3; EU3+ ION LUMINESCENCE LIFETIME; TEMPERATURE EFFECT UPON LUMINESCENCE LIFETIME ID THERMAL-DECOMPOSITION; OXALATE C1 UNIV TENNESSEE,DEPT CHEM,KNOXVILLE,TN 37996. WINSTON SALEM STATE UNIV,DEPT PHYS SCI,WINSTON SALEM,NC 27110. OAK RIDGE NATL LAB,DIV CHEM & ANALYT SCI,TRANSURANIUM RES LAB,OAK RIDGE,TN 37831. NR 6 TC 5 Z9 5 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 SEP PY 1994 VL 48 IS 9 BP 1174 EP 1176 DI 10.1366/0003702944029488 PG 3 WC Instruments & Instrumentation; Spectroscopy SC Instruments & Instrumentation; Spectroscopy GA PL056 UT WOS:A1994PL05600020 ER PT J AU PEAK, MJ PEAK, JG STEVENS, FJ BLAMEY, J MAI, X ZHOU, ZH ADAMS, MWW AF PEAK, MJ PEAK, JG STEVENS, FJ BLAMEY, J MAI, X ZHOU, ZH ADAMS, MWW TI THE HYPERTHERMOPHILIC GLYCOLYTIC ENZYME ENOLASE IN THE ARCHAEON, PYROCOCCUS-FURIOUSUS - COMPARISON WITH MESOPHILIC ENOLASES SO ARCHIVES OF BIOCHEMISTRY AND BIOPHYSICS LA English DT Article ID MUSCLE-SPECIFIC ENOLASE; THERMOSTABLE GLUTAMATE-DEHYDROGENASE; NUCLEOTIDE-SEQUENCE; MOLECULAR-CLONING; ALPHA-ENOLASE; CDNA CLONING; FURIOSUS; ARCHAEBACTERIUM; GENE; PATHWAY AB High enolase activity, as measured by the conversion of 2-phosphoglycerate to phosphoenolpyruvate, was found in the cytoplasm of Pyrococcus furiosus (an anaerobic, hyperthermophilic archaeon that grows optimally at 100 degrees C). In this organism, the enzyme probably functions in a sugar fermentation pathway. The enzyme was purified to homogeneity. It had a temperature optimum of >90 degrees C and a pH optimum of 8.1. The enzyme was extremely thermostable with a time for 50% inactivation at 100 degrees C of 40 min. In contrast, an enolase from yeast was totally inactivated in 1 min at 88 degrees C. Both the P. furiosus and yeast enzymes required a metal ion for activity, but whereas the yeast enzyme has an absolute requirement for Mg2+, the P. furiosus enolase was equally active in the presence of Mn2+. Both enzymes were competitively inhibited by citrate. P. furiosus enolase, as for mesophilic enolases, probably has a homodimeric structure with subunit M(r) greater than 45,000. A highly conserved sequence of eight amino acids in the N-terminal region was found in enolases from P. furiosus and a wide range of other organisms including bacteria, yeast, birds, and mammals. Substantial differences in the thermal properties of the hyperthermophilic enzyme compared with that from less extreme thermophiles and mesophiles might be due to a substantially enhanced composition of hydrophobic amino acids. C1 UNIV GEORGIA, DEPT BIOCHEM, ATHENS, GA 30602 USA. UNIV GEORGIA, CTR METALLOENZYME STUDIES, ATHENS, GA 30602 USA. RP ARGONNE NATL LAB, CTR MECH BIOL & BIOTECHNOL, 9700 S CASS AVE, ARGONNE, IL 60439 USA. NR 42 TC 26 Z9 27 U1 1 U2 3 PU ELSEVIER SCIENCE INC PI NEW YORK PA 360 PARK AVE SOUTH, NEW YORK, NY 10010-1710 USA SN 0003-9861 EI 1096-0384 J9 ARCH BIOCHEM BIOPHYS JI Arch. Biochem. Biophys. PD SEP PY 1994 VL 313 IS 2 BP 280 EP 286 DI 10.1006/abbi.1994.1389 PG 7 WC Biochemistry & Molecular Biology; Biophysics SC Biochemistry & Molecular Biology; Biophysics GA PE541 UT WOS:A1994PE54100013 PM 8080274 ER PT J AU BERSHADY, MA HERELD, M KRON, RG KOO, DC MUNN, JA MAJEWSKI, SR AF BERSHADY, MA HERELD, M KRON, RG KOO, DC MUNN, JA MAJEWSKI, SR TI THE OPTICAL AND NEAR-INFRARED COLORS OF GALAXIES .1. THE PHOTOMETRIC DATA SO ASTRONOMICAL JOURNAL LA English DT Article ID SPIRAL GALAXIES; FAINT GALAXIES; MULTICOLOR PHOTOMETRY; SPECTROSCOPIC SURVEY; SPACE TELESCOPE; COMPLETE SAMPLE; STARS; LUMINOSITY; COUNTS; SPECTROPHOTOMETRY AB We present optical and near-infrared photometry and spectroscopic redshifts of a well defined sample of 171 field galaxies selected from three high galactic latitude fields. This data set forms the basis for subsequent studies to characterize the trends, dispersion, and evolution of rest-frame colors and image structure. A subset of 143 galaxies constitutes a magnitude-limited sample to B similar to 19.9-20.75 (depending on field), with a median redshift of 0.14, and a maximum redshift of 0.54. This subset is statistically representative in its sampling of the apparent color distribution of galaxies. Thirty six galaxies were selected to have the reddest red-optical colors in two redshift intervals between 0.2 2000 K and from zero pressure to more than 10(5) bar (10 GPa). The equation was calibrated using properties predicted by existing formulations at low to moderate PTconditions, original experimental PVTdata at higher pressures, corresponding states comparisons at higher temperatures and using shock compression data at still higher PTs. Extensive comparisons illustrating the correlation of our new EOS with available phase equilibria and volumetric data are provided. Fugacities of carbon dioxide at high pressures and temperatures predicted using our EOS are in agreement with mineral equilibria calculated from internally consistent thermodynamic data for minerals. C1 UNIV BAYREUTH,BAYER GEOINST,D-95440 BAYREUTH,GERMANY. UNIV CALIF BERKELEY,DEPT CHEM,BERKELEY,CA 94720. UNIV CALIF BERKELEY,LAWRENCE BERKELEY LAB,BERKELEY,CA 94720. NR 39 TC 56 Z9 59 U1 1 U2 8 PU SPRINGER VERLAG PI NEW YORK PA 175 FIFTH AVE, NEW YORK, NY 10010 SN 0010-7999 J9 CONTRIB MINERAL PETR JI Contrib. Mineral. Petrol. PD SEP PY 1994 VL 117 IS 4 BP 362 EP 374 DI 10.1007/BF00307271 PG 13 WC Geochemistry & Geophysics; Mineralogy SC Geochemistry & Geophysics; Mineralogy GA PJ454 UT WOS:A1994PJ45400003 ER PT J AU LOCKETT, SJ HERMAN, B AF LOCKETT, SJ HERMAN, B TI AUTOMATIC DETECTION OF CLUSTERED, FLUORESCENT-STAINED NUCLEI BY DIGITAL IMAGE-BASED CYTOMETRY SO CYTOMETRY LA English DT Article DE IMAGE ANALYSIS; IMAGE CYTOMETRY; NUCLEI; TISSUE SECTIONS ID LIGHT-MICROSCOPY; SEGMENTATION; CARCINOMA; SMEARS; CANCER; THICK AB Automatic image-based cytometry (IC) can conveniently quantify the distributions of several specific, fluorescence-labeled molecules within individual, isolated cells of slide- or tissue-based specimens. However, many specimens contain clusters of cells or nuclei that are not detected as individual entities by existing automatic methods. We have developed analysis algorithms which detect individual nuclei occurring in clusters or as isolated nuclei. Specimens were labeled with a fluorescent DNA stain, imaged and the images were segmented into regions of nuclei and background. Clusters of nuclei, identified by their size and shape, were divided into individual nuclei by searching for dividing paths between nuclei. The paths, which need not be straight, possessed the highest average gradient per pixel. In addition, both high- and low-pass filtered images of the original image were analyzed. For each individual nucleus, one of the three segmented regions representing the nucleus (from either the original or one of two filtered images) was chosen as the final result, based on the closeness of the regions to average nuclear morphology. The algorithms correctly detected a high proportion of isolated (328/333) and clustered (254/271) nuclei when applied to images of 2 mu m prostate and breast cancer sections. Thus, these algorithms should enable much more accurate detection and analyses of nuclei in intact specimens. (C) 1994 Wiley-Liss, Inc. C1 UNIV N CAROLINA,DEPT CELL BIOL & ANAT,CELL BIOL LABS,CHAPEL HILL,NC 27599. RP LOCKETT, SJ (reprint author), UNIV CALIF BERKELEY,LAWRENCE BERKELEY LAB,MAIL STOP 74-157,1 CYCLOTRON RD,BERKELEY,CA 94720, USA. NR 40 TC 42 Z9 42 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 0196-4763 J9 CYTOMETRY JI Cytometry PD SEP 1 PY 1994 VL 17 IS 1 BP 1 EP 12 DI 10.1002/cyto.990170102 PG 12 WC Biochemical Research Methods; Cell Biology SC Biochemistry & Molecular Biology; Cell Biology GA PD154 UT WOS:A1994PD15400001 PM 7528121 ER PT J AU DEKA, C SKLAR, LA STEINKAMP, JA AF DEKA, C SKLAR, LA STEINKAMP, JA TI FLUORESCENCE LIFETIME MEASUREMENTS IN A FLOW CYTOMETER BY AMPLITUDE DEMODULATION USING DIGITAL DATA-ACQUISITION TECHNIQUE SO CYTOMETRY LA English DT Note DE FLUORESCENCE LIFETIME; FREQUENCY-DOMAIN; AMPLITUDE DEMODULATION; PHASE-SHIFT; DIGITAL DATA ACQUISITION; FLOW CYTOMETER ID PHASE; RESOLUTION; FLUOROPHORES; SPECTROSCOPY AB We have developed a method for fluorescence lifetime measurements in a flow cytometer based upon the amplitude demodulation of the fluorescence signals using digital data acquisition techniques. Amplitude demodulation is one of the two methods by which excited state lifetimes may be investigated in the frequency domain. The other method involves the phase-shift measurements. In frequency-domain measurement techniques, the amplitude-demodulation and phase-shift data serve mutually complementary roles to enhance the analytical capabilities of the measurements. The purpose of having amplitude demodulation measurement capability is to obtain information that supplements, rather than replaces, that obtained by the phase-shift method alone. Application of amplitude demodulation measurements has been widely explored in static, cuvette-based, frequency domain systems. However, due to time dependence of the amplitude of the modulated fluorescence signal in a flow cytometer, the amplitude demodulation measurements in flow turns out to be more complicated than similar measurements in a static system. The goal of the present work is to explore the problems involved in amplitude demodulation measurements in flow (using digital method), through detailed theoretical modeling and use the model to develop a practical method that can be incorporated into a flow cytometer to measure amplitude modulation lifetimes. We experimentally verify the amplitude demodulation measurement capability of this method using fluorescent microspheres. The experimental measurements show good agreement with static frequency-domain measurements on microspheres in bulk suspensions. (C) 1994 Wiley-Liss, Inc. C1 UNIV NEW MEXICO,SCH MED,ALBUQUERQUE,NM 87131. RP DEKA, C (reprint author), LOS ALAMOS NATL LAB,GROUP LS1,MAIL STOP M888,LOS ALAMOS,NM 87545, USA. FU NCRR NIH HHS [RR 06490, P41-RR01315, R01-RR07855] NR 11 TC 24 Z9 24 U1 2 U2 3 PU WILEY-LISS PI NEW YORK PA DIV JOHN WILEY & SONS INC 605 THIRD AVE, NEW YORK, NY 10158-0012 SN 0196-4763 J9 CYTOMETRY JI Cytometry PD SEP 1 PY 1994 VL 17 IS 1 BP 94 EP 101 DI 10.1002/cyto.990170112 PG 8 WC Biochemical Research Methods; Cell Biology SC Biochemistry & Molecular Biology; Cell Biology GA PD154 UT WOS:A1994PD15400011 PM 8001462 ER PT J AU STRAIT, RS AF STRAIT, RS TI DECISION-ANALYSIS APPROACH TO COMPETITIVE SITUATIONS WITH A PURE INFINITE REGRESS SO DECISION SCIENCES LA English DT Article AB If the standard decision analysis approach was applied to a competitive situation, then the decision maker would attempt to assess a subjective probability distribution over all possible actions by the competitors or rivals. However, in assessing this probability distribution, the decision maker would quickly find him/herself in an infinite regress. There is a range of possible dependencies between the decision maker's decision and the rival's action that lead to such a regress. This paper presents an approach to overcoming this infinite regress in performing decision analyses of competitive situations with a ''pure'' infinite regress. In a pure infinite regress there is a dependency between the decision maker's decision and the rival's choice of action: if the decision maker prefers one alternative to any other, then the rival's actions will reflect a belief by the rival that the preferred alternative is more likely to be the decision maker's decision. The approach builds the decision maker's preferred rank order of alternatives, while simultaneously constructing a consistent model of the rival's beliefs about the decision maker's decision. RP STRAIT, RS (reprint author), LAWRENCE LIVERMORE NATL LAB,LIVERMORE,CA 94551, USA. NR 6 TC 3 Z9 3 U1 0 U2 1 PU DECISION SCIENCES INST, GEORGIA STATE UNIV PI ATLANTA PA COLLEGE OF BUSINESS ADMN, UNIVERSITY PLAZA, ATLANTA, GA 30303 SN 0011-7315 J9 DECISION SCI JI Decis. Sci. PD SEP-DEC PY 1994 VL 25 IS 5-6 BP 853 EP 862 DI 10.1111/j.1540-5915.1994.tb00833.x PG 10 WC Management SC Business & Economics GA QP073 UT WOS:A1994QP07300008 ER PT J AU SCHIERENBECK, KA MACK, RN SHARITZ, RR AF SCHIERENBECK, KA MACK, RN SHARITZ, RR TI EFFECTS OF HERBIVORY ON GROWTH AND BIOMASS ALLOCATION IN NATIVE AND INTRODUCED SPECIES OF LONICERA SO ECOLOGY LA English DT Article DE BIOMASS ALLOCATION; COMPENSATORY RESPONSE; HERBIVORY; INVASIVE SPECIES; LONICERA JAPONICA; LONICERA SEMPERVIRENS; SOUTHEASTERN US ID CARBON GAIN; SOUTHERN WISCONSIN; PLANT-RESPONSES; HONEYSUCKLE; ECOPHYSIOLOGY; AVAILABILITY; CONSTRAINTS; SUCCESSION; ECOLOGY; SHRUBS AB We compared growth and biomass allocation patterns of Lonicera japonica, an invasive vine in the southeastern United States, and its native congener, L. sempervirens, among three herbivory treatments. Growth and biomass variables were calculated at nine harvest dates across 14 mo under no herbivory, insect herbivory, and mammal and insect herbivory. In the absence of herbivory, L. sempervirens accumulated greater biomass and had higher growth rates than L. japonica. Lonicera sempervirens, however, experienced more herbivore damage than L. japonica, particularly due to the combined effects of insect and mammal herbivory. Total biomass accumulation and greater allocation to leaves and stems indicate a compensatory response to herbivory by L. japonica. These attributes in response to herbivory coupled with lower herbivory in its new range compared to L. sempervirens could give L. japonica a substantial advantage over its native congener. C1 WASHINGTON STATE UNIV,DEPT BOT,PULLMAN,WA 99163. SAVANNAH RIVER ECOL LAB,AIKEN,SC 29803. NR 57 TC 129 Z9 138 U1 4 U2 49 PU ECOLOGICAL SOC AMER PI WASHINGTON PA 2010 MASSACHUSETTS AVE, NW, STE 400, WASHINGTON, DC 20036 SN 0012-9658 J9 ECOLOGY JI Ecology PD SEP PY 1994 VL 75 IS 6 BP 1661 EP 1672 DI 10.2307/1939626 PG 12 WC Ecology SC Environmental Sciences & Ecology GA PE267 UT WOS:A1994PE26700014 ER PT J AU DOYLE, M FULLER, TF NEWMAN, J AF DOYLE, M FULLER, TF NEWMAN, J TI THE IMPORTANCE OF THE LITHIUM ION TRANSFERENCE NUMBER IN LITHIUM POLYMER CELLS SO ELECTROCHIMICA ACTA LA English DT Article DE LITHIUM; POLYMER ELECTROLYTE; TRANSFERENCE NUMBER; MODELING; BATTERY ID ELECTROLYTES; CONDUCTIVITY; SALTS; ACID AB Simulation results are presented for a lithium negative electrode, solid polymer separator, manganese dioxide composite positive electrode cell. In particular, we assess the effect of conductivity and transference number on cell performance, establishing criteria for situations when a trade-off between these two properties is expected. We show that polymer-electrolyte systems with a unity transference number have improved performance over systems with t+0 = 0.2, even when the conductivity is decreased by an order of magnitude. The improvements are primarily at higher rates of discharge, where the latter cell would be depleted of electrolyte due to large concentration gradients that develop. Cells with a unity transference number have larger energy densities and can attain higher peak-power densities. C1 LAWRENCE BERKELEY LAB,DIV MAT SCI,BERKELEY,CA 94720. RP DOYLE, M (reprint author), UNIV CALIF BERKELEY,DEPT CHEM ENGN,BERKELEY,CA 94720, USA. RI Fuller, Thomas/D-5534-2009; Newman, John/B-8650-2008 OI Newman, John/0000-0002-9267-4525 NR 26 TC 180 Z9 181 U1 11 U2 88 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD, ENGLAND OX5 1GB SN 0013-4686 J9 ELECTROCHIM ACTA JI Electrochim. Acta PD SEP PY 1994 VL 39 IS 13 BP 2073 EP 2081 DI 10.1016/0013-4686(94)85091-7 PG 9 WC Electrochemistry SC Electrochemistry GA PE261 UT WOS:A1994PE26100019 ER PT J AU FRANZ, JA FERRIS, KF CAMAIONI, DM AUTREY, ST AF FRANZ, JA FERRIS, KF CAMAIONI, DM AUTREY, ST TI ARE STRONG BONDS CLEAVED DURING COAL-LIQUEFACTION VIA RADICAL HYDROGEN-TRANSFER - AN AB-INITIO THEORETICAL-STUDY OF THERMONEUTRAL RADICAL HYDROGEN-TRANSFER SO ENERGY & FUELS LA English DT Article ID ANTHRACENE STRUCTURES; DEGRADATION; MECHANISMS; PARAMETERS; SCISSION; MODEL AB Ab initio calculations of adiabatic barriers for the prototypical radical hydrogen transfer (RHT) reaction, bimolecular transfer of hydrogen atom from ethyl radical to ethylene and, for comparison, the hydrogen abstraction reaction, ethyl + ethane, were carried out at the spin-projected UHF mp2/6-31g** level with thermal corrections. The mp2/6-31g** barrier for the abstraction reaction, 15.5 kcal/mol (vs experiment, 12.6 kcal/mol), can be compared with the much higher intrinsic barrier for RHT from ethyl to ethylene, 27.2 kcal/mol. The RHT barrier is less than that of hydrogen atom loss, 37 kcal/mol. This barrier, together with other considerations, suggests that the RHT reaction is a much higher energy pathway than widely assumed. RP FRANZ, JA (reprint author), PACIFIC NW LAB, BATTELLE BLVD,POB 999, RICHLAND, WA 99352 USA. NR 32 TC 12 Z9 13 U1 1 U2 1 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 SN 0887-0624 J9 ENERG FUEL JI Energy Fuels PD SEP-OCT PY 1994 VL 8 IS 5 BP 1016 EP 1019 DI 10.1021/ef00047a002 PG 4 WC Energy & Fuels; Engineering, Chemical SC Energy & Fuels; Engineering GA PG748 UT WOS:A1994PG74800002 ER PT J AU FAULON, JL AF FAULON, JL TI CALCULATING THE NUMBER AVERAGED MOLECULAR-WEIGHT (M(0)) OF AROMATIC AND HYDROAROMATIC CLUSTERS IN COAL USING RUBBER ELASTICITY THEORY SO ENERGY & FUELS LA English DT Article ID POLYMER NETWORKS; MODEL AB For the past 10 years, rubber elasticity theory has been applied to coal to calculate the number-averaged molecular weight between branch points (M(c)) and the number-averaged molecular weight of aromatic/hydroaromatic clusters (M(o)). In the equations that have been proposed in the context of coal, the average number of statistical links between branch points (N) was always assumed to be equal to the average number of clusters between branch points (N'). The present paper demonstrates that this assumption is invalid for highly cross-linked polymer networks. Modified equations are proposed for which the assumption N = N' is no longer considered valid. The main consequence of the modification is that the number-averaged molecular weight of coal clusters is greater than previously reported. RP FAULON, JL (reprint author), SANDIA NATL LABS,POB 5800,ALBUQUERQUE,NM 87185, USA. NR 15 TC 7 Z9 7 U1 1 U2 1 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 SN 0887-0624 J9 ENERG FUEL JI Energy Fuels PD SEP-OCT PY 1994 VL 8 IS 5 BP 1020 EP 1023 DI 10.1021/ef00047a003 PG 4 WC Energy & Fuels; Engineering, Chemical SC Energy & Fuels; Engineering GA PG748 UT WOS:A1994PG74800003 ER PT J AU HARTGERS, WA DAMSTE, JSS DELEEUW, JW LING, Y DYRKACZ, GR AF HARTGERS, WA DAMSTE, JSS DELEEUW, JW LING, Y DYRKACZ, GR TI MOLECULAR CHARACTERIZATION OF FLASH PYROLYSATES OF 2 CARBONIFEROUS COALS AND THEIR CONSTITUTING MACERAL FRACTIONS SO ENERGY & FUELS LA English DT Article ID CHROMATOGRAPHY-MASS-SPECTROMETRY; POLYCYCLIC AROMATIC-HYDROCARBONS; FLOW CENTRIFUGATION TECHNIQUES; NUCLEAR-MAGNETIC-RESONANCE; AUSTRALIAN CRUDE OILS; GAS-CHROMATOGRAPHY; ORGANIC SULFUR; GEOCHEMICAL SIGNIFICANCE; ANCIENT SEDIMENTS; BITUMINOUS COAL AB Two high-volatile bituminous Upper Carboniferous coals from the Argonne Premium Coal Set and their constituting liptinite, vitrinite, and inertinite fractions, obtained by density gradient centrifugation (DGC), were characterized by Curie point pyrolysis-gas chromatography-mass spectrometry. A detailed analysis of the pyrolysis products was performed to relate individual macerals to their (plant-derived) precursors. Liptinite fractions were found to be mainly composed of sporinite, the diagenetic product of sporopollenin. Its aliphatic character was reflected in its pyrolysate by the abundance and characteristic distribution of n-alk-1-enes and n-alkanes showing maxima at C-11 and C-25 Moreover, a selective enrichment of aromatic components derived from linear carbon skeletons via cyclization and aromatization of functionalized, linear precursors was observed. In the sulfur-rich Illinois No. 6 coal, the addition of abiotic inorganic sulfur species to functional groups was reflected by a selective enrichment of organic sulfur compounds in the liptinite maceral. Diagenetically altered lignin derived from gymnospermous wood is the most likely precursor for vitrinite, the major constituent of both coals. Flash pyrolysates of vitrinite fractions were dominated by alkylbenzenes and alkylphenols. Inertinite fractions exhibited relatively high amounts of(poly)aromatic pyrolysis products. Thermal extraction experiments revealed that these components were mainly present as such adsorbed to or entrapped in the pore system of the maceral matrix. C1 DELFT UNIV TECHNOL,FAC CHEM TECHNOL & MAT SCI,ORGAN GEOCHEM UNIT,2628 RZ DELFT,NETHERLANDS. ARGONNE NATL LAB,DIV CHEM,ARGONNE,IL 60439. RP HARTGERS, WA (reprint author), NETHERLANDS INST SEA RES,DIV MARINE BIOGEOCHEM,POB 59,1790 AB DEN BURG,NETHERLANDS. RI de Leeuw, Jan/F-6471-2011; Sinninghe Damste, Jaap/F-6128-2011 OI Sinninghe Damste, Jaap/0000-0002-8683-1854 NR 72 TC 34 Z9 38 U1 0 U2 0 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 SN 0887-0624 J9 ENERG FUEL JI Energy Fuels PD SEP-OCT PY 1994 VL 8 IS 5 BP 1055 EP 1067 DI 10.1021/ef00047a008 PG 13 WC Energy & Fuels; Engineering, Chemical SC Energy & Fuels; Engineering GA PG748 UT WOS:A1994PG74800008 ER PT J AU WORNAT, MJ PORTER, BG YANG, NYC AF WORNAT, MJ PORTER, BG YANG, NYC TI SINGLE DROPLET COMBUSTION OF BIOMASS PYROLYSIS OILS SO ENERGY & FUELS LA English DT Article ID MOLECULAR CHARACTERIZATION; FUEL DROPLET; FUNDAMENTALS; EMULSIONS AB In an investigation of the combustion behavior of biomass-derived liquids, we have performed single droplet experiments with two biomass oils, produced from the pyrolysis of oak and pine. The experiments are conducted at 1600 K on 320 mu m diameter droplets introduced into a laminar flow reactor, operating at O-2 concentrations of 14-33 mol %. In-situ video imaging of burning droplets reveals that biomass oil droplets undergo several distinct stages of combustion. Initially biomass oil droplets burn quiescently in a blue flame. The broad range of component volatilities and inefficient mass transfer within the viscous biomass oils bring about an abrupt termination of the quiescent stage, however, causing rapid droplet swelling and distortion, followed by a microexplosion. Droplet coalescence follows, and subsequent burning occurs in a faint blue flame with occasional smaller scale bursts of fuel vapor. At the late stages of biomass oil combustion, droplets are accompanied by clouds of soot, produced from gas-phase pyrolysis. Liquid-phase polymerization or pyrolysis of the oxygenate-rich biomass oils leads to the formation of carbonaceous cenospheres, whose burnout signifies the final stage of biomass oil droplet combustion. Oak and pine oils behave similarly during combustion, though differences in their physical properties cause pine oil to show more susceptibility to fragmentation during the microexplosion. Changes in oxygen concentration alter the timing of the events during biomass oil combustion, but not their nature. Comparison of the biomass oils with No, 2 fuel oil reveals vast differences in combustion mechanisms, which are attributable to differences in the physical properties and chemical compositions of the fuels. Despite these differences, the biomass oils and No. 2 fuel oil exhibit surprisingly comparable burning times under the conditions of our experiments. C1 SANDIA NATL LABS,COMBUST RES FACIL,LIVERMORE,CA 94550. CTR MAT & APPL MECH,LIVERMORE,CA 94550. NR 59 TC 67 Z9 70 U1 2 U2 5 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 SN 0887-0624 J9 ENERG FUEL JI Energy Fuels PD SEP-OCT PY 1994 VL 8 IS 5 BP 1131 EP 1142 DI 10.1021/ef00047a018 PG 12 WC Energy & Fuels; Engineering, Chemical SC Energy & Fuels; Engineering GA PG748 UT WOS:A1994PG74800018 ER PT J AU BERNSTEIN, M FARRELL, A WINEBRAKE, J AF BERNSTEIN, M FARRELL, A WINEBRAKE, J TI THE ENVIRONMENT AND ECONOMICS - THE IMPACT OF RESTRICTING THE SO2 ALLOWANCE MARKET SO ENERGY POLICY LA English DT Article DE ENERGY POLICY; SULFUR DIOXIDE ALLOWANCE TRADING; ENVIRONMENTAL POLICY ID EMPIRICAL PROPERTIES; AIR-POLLUTION; PERMITS AB This paper analyzes the effects of several types of regulatory policy on the operation of the SO2 allowance trading system established in the US Clean Air Act Amendments of 1990 (CAAA). Theoretically, such a system can achieve environmental goals at least cost. However, regional environment and employment concerns have suggested regulations in some states that will restrict full market operation, thereby negating many of the efficiency gains that market based regulation is designed to capture. This paper determines the costs of these regulatory interventions. These costs can be compared with employment and environmental impacts to assist policy makers in their regulatory decisions. C1 UNIV PENN,CTR ENERGY & ENVIRONM,PHILADELPHIA,PA 19104. RP BERNSTEIN, M (reprint author), NATL RENEWABLE ENERGY LAB,409 12TH ST SW,SUITE 710,WASHINGTON,DC 20024, USA. RI Winebrake, James/D-2478-2010 NR 19 TC 8 Z9 8 U1 1 U2 4 PU BUTTERWORTH-HEINEMANN LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD, OXON, ENGLAND OX5 1GB SN 0301-4215 J9 ENERG POLICY JI Energy Policy PD SEP PY 1994 VL 22 IS 9 BP 748 EP 754 DI 10.1016/0301-4215(94)90050-7 PG 7 WC Energy & Fuels; Environmental Sciences; Environmental Studies SC Energy & Fuels; Environmental Sciences & Ecology GA PR207 UT WOS:A1994PR20700004 ER PT J AU Campbell, K AF Campbell, Katherine TI Identifying extremely large values using composite sample data Discussion SO ENVIRONMENTAL AND ECOLOGICAL STATISTICS LA English DT Article C1 Univ Calif Los Alamos Natl Lab, Stat Grp, Los Alamos, NM 87545 USA. RP Campbell, K (reprint author), Univ Calif Los Alamos Natl Lab, Stat Grp, Los Alamos, NM 87545 USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU SPRINGER PI DORDRECHT PA VAN GODEWIJCKSTRAAT 30, 3311 GZ DORDRECHT, NETHERLANDS SN 1352-8505 EI 1573-3009 J9 ENVIRON ECOL STAT JI Environ. Ecol. Stat. PD SEP PY 1994 VL 1 IS 3 BP 243 EP 244 DI 10.1007/BF00571397 PG 3 WC Environmental Sciences; Mathematics, Interdisciplinary Applications; Statistics & Probability SC Environmental Sciences & Ecology; Mathematics GA V31TI UT WOS:000208905500012 ER PT J AU FLEMING, DM WOLFF, WF DEANGELIS, DL AF FLEMING, DM WOLFF, WF DEANGELIS, DL TI IMPORTANCE OF LANDSCAPE HETEROGENEITY TO WOOD STORKS IN FLORIDA EVERGLADES SO ENVIRONMENTAL MANAGEMENT LA English DT Article DE COMPUTER SIMULATION; WOOD STORKS; WADING BIRDS; EVERGLADES; INDIVIDUAL-BASED MODELING; LANDSCAPE HETEROGENEITY ID WADING BIRDS; WATER-FLOW; MANAGEMENT; POPULATION; PATTERNS; BAY AB Declines in populations of and reproductive success of wood storks and other wading birds have occurred in the Florida Everglades over the past several decades. These declines have been concurrent with major changes in the Everglades' landscape characteristics. Among the plausible hypotheses that relate to landscape change are the following: (1) general loss of habitat; (2) heavy loss of specific habitat, namely, short-hydroperiod wetlands that provide high prey availability early in the breeding season; and (3) an increase in frequency of major drying out of the central slough areas, which can affect prey availability late in the breeding season. These three hypotheses were compared using an individual-based model of wood stork (Mycteria americana) reproduction. This model simulated the behavior and energetics of each individual wood stork in a breeding colony on 15-min time intervals. Changes in water depth and prey availability occurred on daily time steps. Simulation results showed a threshold response in reproductive success to reduction of wetland heterogeneity. Model comparisons in which (1) only short-hydroperiod wetlands were removed and (2) wetlands of both long and short hydroperiods were removed showed that, for the same loss of total area, the specific habitat removal caused a much greater reduction in wood stork reproduction, indicating hypothesis 2 may be a more likely explanation than hypothesis 1. Reduction of initial prey availability in the central slough areas (simulating frequent drying; hypothesis 3) reduced fledging success by an average of more than 90% in the model. C1 OAK RIDGE NATL LAB,DIV ENVIRONM SCI,POB 2008,OAK RIDGE,TN 37831. NATL BIOL SURVEY,EVERGLADES NATL PK FIELD STN,HOMESTEAD,FL 33034. FORSCHUNGSZENTRUM JUELICH,INST BIOTECHNOL 3,JULICH,GERMANY. NR 49 TC 34 Z9 36 U1 3 U2 7 PU SPRINGER VERLAG PI NEW YORK PA 175 FIFTH AVE, NEW YORK, NY 10010 SN 0364-152X J9 ENVIRON MANAGE JI Environ. Manage. PD SEP-OCT PY 1994 VL 18 IS 5 BP 743 EP 757 DI 10.1007/BF02394637 PG 15 WC Environmental Sciences SC Environmental Sciences & Ecology GA NY153 UT WOS:A1994NY15300008 ER PT J AU JACOBY, WA NIMLOS, MR BLAKE, DM NOBLE, RD KOVAL, CA AF JACOBY, WA NIMLOS, MR BLAKE, DM NOBLE, RD KOVAL, CA TI PRODUCTS, INTERMEDIATES, MASS BALANCES, AND REACTION PATHWAYS FOR THE OXIDATION OF TRICHLOROETHYLENE IN AIR VIA HETEROGENEOUS PHOTOCATALYSIS SO ENVIRONMENTAL SCIENCE & TECHNOLOGY LA English DT Article ID TITANIUM-DIOXIDE AB Studies of the photocatalytic reaction of a solution of trichloroethylene in the air and in contact with UV-irradiated titanium dioxide have produced conflicting reports in regard to the composition of the product mixture. This paper resolves these discrepancies by reporting the results of experiments designed to identify and quantify intermediates, products, and reaction pathways. Mass balances are closed in differential and integral modes to ascertain the effects of factors such as the extent of conversion, feed composition, and photon energy on the composition of the product stream. Dichloroacetyl chloride, phosgene, carbon dioxide, carbon monoxide, and hydrogen chloride were observed in the effluent of photocatalytic reactors featuring thin films of titanium dioxide catalyst. These observations were made with a gas-phase Fourier transform infrared spectrometer. The instrument directly samples the effluent from the reactor without splitting or dilution. A direct sampling molecular beam mass spectrometer used in a parallel study has also identified molecular chlorine as a component of the effluent. C1 UNIV COLORADO, BOULDER, CO 80302 USA. RP JACOBY, WA (reprint author), NATL RENEWABLE ENERGY LAB, 1617 COLE BLVD, GOLDEN, CO 80401 USA. NR 21 TC 111 Z9 111 U1 2 U2 11 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 0013-936X J9 ENVIRON SCI TECHNOL JI Environ. Sci. Technol. PD SEP PY 1994 VL 28 IS 9 BP 1661 EP 1668 DI 10.1021/es00058a018 PG 8 WC Engineering, Environmental; Environmental Sciences SC Engineering; Environmental Sciences & Ecology GA PE258 UT WOS:A1994PE25800023 PM 22176368 ER PT J AU RUSIN, PA QUINTANA, L BRAINARD, JR STRIETELMEIER, BA TAIT, CD EKBERG, SA PALMER, PD NEWTON, TW CLARK, DL AF RUSIN, PA QUINTANA, L BRAINARD, JR STRIETELMEIER, BA TAIT, CD EKBERG, SA PALMER, PD NEWTON, TW CLARK, DL TI SOLUBILIZATION OF PLUTONIUM HYDROUS OXIDE BY IRON-REDUCING BACTERIA SO ENVIRONMENTAL SCIENCE & TECHNOLOGY LA English DT Article ID MANGANESE REDUCTION; ELECTRON-TRANSPORT; BACILLUS; URANIUM; SILVER AB The removal of plutonium from soils is challenging because of its strong sorption to soils and limited solubility. Microbial reduction of metals is known to affect the speciation and solubility of sparingly soluble metals in the environment, notably iron and manganese. The similarity in reduction potential for alpha-FeOOH(s) and hydrous PuO2(s) suggests that iron-reducing bacteria may also reduce and solubilize plutonium. Bacillus strains were used to demonstrate that iron-reducing bacteria mediate the solubilization of hydrous PuO2(s) under anaerobic conditions. Up to similar to 90% of the PuO2 was biosolubilized in the presence of nitrilotriacetic acid (NTA) within 6-7 days. Biosolubilization occurred to a lesser extent (similar to 40%) in the absence of NTA. Little PuO2 solubilization occurred in sterile culture media or in the presence of a non-iron-reducing Escherichia coli. These observations suggest a potentially attractive, environmentally benign strategy for the remediation of Pu-contaminated soils. C1 LOS ALAMOS NATL LAB, LOS ALAMOS, NM 87545 USA. RP RUSIN, PA (reprint author), MBX SYST INC, 325 S EUCLID, SUITE 123, TUCSON, AZ 85719 USA. RI Clark, David/A-9729-2011 NR 26 TC 65 Z9 66 U1 0 U2 7 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 0013-936X EI 1520-5851 J9 ENVIRON SCI TECHNOL JI Environ. Sci. Technol. PD SEP PY 1994 VL 28 IS 9 BP 1686 EP 1690 DI 10.1021/es00058a021 PG 5 WC Engineering, Environmental; Environmental Sciences SC Engineering; Environmental Sciences & Ecology GA PE258 UT WOS:A1994PE25800026 PM 22176371 ER PT J AU SZECSODY, JE ZACHARA, JM BRUCKHART, PL AF SZECSODY, JE ZACHARA, JM BRUCKHART, PL TI ADSORPTION-DISSOLUTION REACTIONS AFFECTING THE DISTRIBUTION AND STABILITY OF CO(II)EDTA IN IRON OXIDE-COATED SAND SO ENVIRONMENTAL SCIENCE & TECHNOLOGY LA English DT Article ID METAL HYDROUS OXIDES; CHELATING-AGENTS; COORDINATION CHEMISTRY; SELECTIVE EXTRACTION; EDTA COMPLEXES; MIGRATION; KINETICS; TRANSPORT; OXYHYDROXIDE; DELTA-AL2O3 AB The time-variant chemical behavior of Co(II)EDTA (and other metal-EDTA complexes) was investigated in suspensions ofiron oxide-coated sand to identify equilibrium and kinetic reactions that control the mobility of Me(II)DTA complexes in subsurface environments. Batch experiments were conducted to evaluate the adsorption as a function of pH, concentration, and time and to quantify the rate-controlling step(s) of dissolution of the iron oxide by EDTA complexes. Ionic Co2+ exhibited typical cation-like adsorption, whereas Me(II)EDTA adsorption was ligand-like, increasing with decreasing pH. Adsorption isotherms for all reactive species exhibited Langmuir behavior, with site saturation occurring at molar values of <0.5% of Fe-tot. The adsorption of Me(II)EDTA enhanced the apparent solubility of the iron oxide phase, which destabilized the Co(II)EDTA complex, liberating Co2+ and Fe(III)EDTA. The dissolution rate was an order of magnitude slower at pH 6.5 than at pH 4.5 and was influenced by there-adsorption of solubilized Fe(III)EDTA. Two multireaction kinetic models were developed that each included Langmuir adsorption for Co2+ and metal-EDTA species but differed in their depiction of the dissolution mechanism (i.e., ligand- versus proton-promoted dissolution). Ligand-promoted dissolution was most consistent with the experimental data. It is suggested that Co(II)DTA will undergo similar reactions in subsurface environments causing complex, distance-variant retardation. RP SZECSODY, JE (reprint author), PACIFIC NW LAB, MAIL STOP K6-77,POB 999, RICHLAND, WA 99352 USA. NR 44 TC 89 Z9 90 U1 1 U2 11 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 SN 0013-936X J9 ENVIRON SCI TECHNOL JI Environ. Sci. Technol. PD SEP PY 1994 VL 28 IS 9 BP 1706 EP 1716 DI 10.1021/es00058a024 PG 11 WC Engineering, Environmental; Environmental Sciences SC Engineering; Environmental Sciences & Ecology GA PE258 UT WOS:A1994PE25800029 PM 22176374 ER PT J AU SPICER, CW KENNY, DV SHAW, WJ BUSNESS, KM CHAPMAN, EG AF SPICER, CW KENNY, DV SHAW, WJ BUSNESS, KM CHAPMAN, EG TI A LABORATORY IN THE SKY - NEW FRONTIERS IN MEASUREMENTS ALOFT SO ENVIRONMENTAL SCIENCE & TECHNOLOGY LA English DT Article C1 US DOE, PACIFIC NW LAB, RICHLAND, WA 99352 USA. RP SPICER, CW (reprint author), BATTELLE MEM INST, DEPT ATMOSPHER SCI & APPL TECHNOL, 505 KING AVE, COLUMBUS, OH 43201 USA. RI Chapman, Elaine/K-8756-2012 NR 3 TC 18 Z9 18 U1 0 U2 1 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 SN 0013-936X J9 ENVIRON SCI TECHNOL JI Environ. Sci. Technol. PD SEP PY 1994 VL 28 IS 9 BP A412 EP A420 DI 10.1021/es00058a001 PG 9 WC Engineering, Environmental; Environmental Sciences SC Engineering; Environmental Sciences & Ecology GA PE258 UT WOS:A1994PE25800006 ER PT J AU GUENTHER, W BRODIE, JD BARTLETT, EJ DEWEY, SL HENN, FA VOLKOW, ND ALPER, K WOLKIN, A CANCRO, R WOLF, AP AF GUENTHER, W BRODIE, JD BARTLETT, EJ DEWEY, SL HENN, FA VOLKOW, ND ALPER, K WOLKIN, A CANCRO, R WOLF, AP TI DIMINISHED CEREBRAL METABOLIC RESPONSE TO MOTOR STIMULATION IN SCHIZOPHRENICS - A PET STUDY SO EUROPEAN ARCHIVES OF PSYCHIATRY AND CLINICAL NEUROSCIENCE LA English DT Article DE SCHIZOPHRENIC BRAIN DYSFUNCTION; PET IN SCHIZOPHRENIA; MOTOR DYSFUNCTION; CORTICAL ACTIVATION IN SCHIZOPHRENIA ID POSITRON EMISSION TOMOGRAPHY; BLOOD-FLOW; GLUCOSE-UTILIZATION; BASAL GANGLIA; VOLUNTARY MOVEMENTS; PREFRONTAL CORTEX; BRAIN; PATHOLOGY; HUMANS; AREA AB Positron emission tomography (PET) and the deoxyglucose method were used to measure cerebral metabolism in 14 normals and 13 schizophrenics at rest and during performance of simple and complex finger-movement sequences. The normals, but not the schizophrenics, showed significant metabolic activation in mesial frontal and contralateral sensorimotor and premotor regions during the complex movement. The relative metabolism of schizophrenics was significantly lower than normal in frontal regions and higher than normal in thalamus and basal ganglia under all scanning conditions. The results suggest that schizophrenics may have a brain dysfunction which limits their capacity to produce a focal metabolic response to stimulation in several functionally distinct brain regions. C1 NYU,MED CTR,DEPT PSYCHIAT,NEW YORK,NY 10017. BROOKHAVEN NATL LAB,DEPT CHEM,UPTON,NY 11973. SUNY STONY BROOK,SCH MED,DEPT PSYCHIAT & BEHAV SCI,STONY BROOK,NY 11694. RP GUENTHER, W (reprint author), UNIV MUNICH,HOSP PSYCHIAT,NUSSBAUMSTR 7,D-80336 MUNICH,GERMANY. RI Alper, Kenneth/B-5676-2009 FU NIMH NIH HHS [MH-42647]; NINDS NIH HHS [NS-15638] NR 65 TC 27 Z9 27 U1 0 U2 0 PU SPRINGER VERLAG PI NEW YORK PA 175 FIFTH AVE, NEW YORK, NY 10010 SN 0940-1334 J9 EUR ARCH PSY CLIN N JI Eur. Arch. Psych. Clin. Neurosci. PD SEP PY 1994 VL 244 IS 3 BP 115 EP 125 DI 10.1007/BF02191884 PG 11 WC Clinical Neurology; Psychiatry SC Neurosciences & Neurology; Psychiatry GA PG575 UT WOS:A1994PG57500002 PM 7803524 ER PT J AU EBBE, S MAURER, H AF EBBE, S MAURER, H TI ERYTHROPOIESIS, BUT NOT THROMBOCYTOPOIESIS, IS AFFECTED BY THE PRESENCE OF A LARGE AMOUNT OF SUBCUTANEOUSLY IMPLANTED BONE-MARROW SO EXPERIMENTAL HEMATOLOGY LA English DT Article DE MEGAKARYOCYTES; PLATELETS; ERYTHROPOIESIS; IRON INCORPORATION; MARROW IMPLANTS ID GROWTH-PROMOTING ACTIVITY; IRRADIATION; INCREASE; RATS AB The concept that megakaryocytopoiesis is regulated in part by the number of megakaryocytes themselves, separately from its regulation by the number of platelets, is referred to as autoregulation. Its occurrence has been implied from animal models that demonstrate compensated megakaryocytopenia. In that condition, normal platelet production can occur even though numbers of megakaryocytes are substantially reduced, and individual megakaryocytes exhibit changes consistent with their being stimulated. The present experiments were undertaken to determine whether the converse situation, namely suppression of megakaryocytopoiesis by an excess of megakaryocytes, could be created. The experimental model consisted of C57Bl mice in which as many as 10 isogeneic femurs were implanted subcutaneously 10 weeks before analysis. The implanted femurs contained hematopoietic marrow morphologically. They incorporated radioiron, but only about 40% as much as an equal number of normal femurs, so hematopoiesis did not regenerate to the full potential of the implanted marrows. After implantation of nine or 10 femurs, thrombocytopoiesis was normal as judged by platelet counts, mean platelet volumes, numbers of megakaryocytes in tibial marrow, and megakaryocyte sizes. Hematocrits were increased, but plasma erythropoietin levels were normal. The implants showed a 15- to 20-hour incorporation of radioiron of 9.4 +/- 0.5%. Iron incorporation into endogenous bones and spleen was reduced, demonstrating that erythropoiesis was redistributed. The total incorporation of iron into all hematopoietic tissue was slightly increased, but red-cell iron incorporation was normal, implying that there was more ineffective erythropoiesis than normal. Leukocyte counts, differentials, and tibial cellularity were normal. After implantation of three or six femurs, no abnormalities of hematopoiesis were detected, even though the implants incorporated iron in proportion to their number. Thus, erythropoiesis was adjusted by the excess of total marrow caused by nine or 10 subcutaneously implanted femurs. This is about the maximum of implanted marrow that is feasible with this model, and the failure to observe suppression of megakaryocytopoiesis may have been due to an inability to achieve a large enough number of megakaryocytes to elicit a detectable response. Alternatively, autoregulation of megakaryocytes may depend more on the marrow concentration of megakaryocytes than on the total body content. C1 UNIV CALIF SAN FRANCISCO, DEPT LAB MED, SAN FRANCISCO, CA 94143 USA. RP EBBE, S (reprint author), UNIV CALIF BERKELEY, LAWRENCE BERKELEY LAB, BLDG 74, 1 CYCLOTRON RD, BERKELEY, CA 94720 USA. NR 12 TC 2 Z9 2 U1 0 U2 0 PU ELSEVIER SCIENCE INC PI NEW YORK PA 360 PARK AVE SOUTH, NEW YORK, NY 10010-1710 USA SN 0301-472X J9 EXP HEMATOL JI Exp. Hematol. PD SEP PY 1994 VL 22 IS 10 BP 1011 EP 1015 PG 5 WC Hematology; Medicine, Research & Experimental SC Hematology; Research & Experimental Medicine GA PG272 UT WOS:A1994PG27200011 PM 8088375 ER PT J AU REYNOLDS, JG TAYLOR, RW MORRIS, CJ AF REYNOLDS, JG TAYLOR, RW MORRIS, CJ TI OXIDIZED OIL-SHALE FOR REMOVAL OF NITROGEN-OXIDES IN COMBUSTION GAS STREAMS SO FUEL LA English DT Article; Proceedings Paper CT 1992 Eastern Oil Shale Symposium (EOSS) CY 1992 CL UNIV KENTUCKY, LEXINGTON, KY SP UNIV KENTUCKY, CTR APPL ENERGY RES, UNIV KENTUCKY, INST MIN & MINERALS RES HO UNIV KENTUCKY DE NOX REMOVAL; COMBUSTION; SHALE AB Oxidized oil shale from the combustor in the Lawrence Livermore National Laboratory (LLNL) hot recycled solids (HRS) oil shale retorting process has been found to be a catalyst for removing nitrogen oxides from laboratory gas streams, using NH3 as a reductant. Oxidized Green River oil shale, heated at 10-degrees-C min-1 in an Ar/O2/NO/NH3 mixture (approximately 93%/6%/2000 ppm/4000 ppm) with a gas residence time of approximately 0.6 s, removed NO between 250 and 500-degrees-C, with maximum removal of 70% at approximately 400-degrees-C. Under isothermal conditions with the same gas mixture, the maximum NO removal was approximately 64%. When CO2 was added to the gas mixture at approximately 8%, the NO removal dropped to approximately 50%. However, increasing the gas residence time to approximately 1.2 s, increased NO removal to 63%. Nitrogen balances of these experiments suggest selective catalytic reduction of NO is occurring using NH3 as the reductant. These results are not based on completely optimized process conditions, but indicate that oxidized oil shale is an effective catalyst for NO removal from combustion gas streams using NH3 as the reductant. Parameters calculated for implementing oxidized oil shale for NO(x) remediation on the current HRS retort, indicate an abatement device is practical to construct. RP REYNOLDS, JG (reprint author), LAWRENCE LIVERMORE NATL LAB,LIVERMORE,CA 94551, USA. NR 11 TC 0 Z9 0 U1 0 U2 2 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 SEP PY 1994 VL 73 IS 9 BP 1466 EP 1471 DI 10.1016/0016-2361(94)90064-7 PG 6 WC Energy & Fuels; Engineering, Chemical SC Energy & Fuels; Engineering GA PC423 UT WOS:A1994PC42300013 ER PT J AU DAMLE, AS GANGWAL, SK VENKATARAMAN, VK AF DAMLE, AS GANGWAL, SK VENKATARAMAN, VK TI CARBON MEMBRANES FOR GAS SEPARATION - DEVELOPMENTAL STUDIES SO GAS SEPARATION & PURIFICATION LA English DT Article DE CARBON COMPOSITE MEMBRANES; GAS SEPARATION; KNUDSEN DIFFUSION; MEMBRANE MODIFICATIONS AB Carbon membranes with 0.2 and 1.0 mum pore sizes are commercially available for liquid microfiltration applications. These membranes may be modified for gas separation applications by providing a gas separation layer with pores in the 1 to 10 nm range. With such pores, gases are separated by Knudsen diffusion with an individual gas species permeation rate inversely proportional to the ratio of the square root of the molecular weight of the permeating species. This paper describes some of the techniques used for depositing a suitable layer starting with various organic polymeric precursors. The in situ polymerization technique was found to be the most promising, and pure component tests with membrane samples prepared with this technique indicated Knudsen diffusion behaviour. The gas separation factors obtained by mixed-gas permeation tests were found to depend strongly on gas temperature and pressure indicating significant viscous flow at high-pressure conditions. C1 RES TRIANGLE INST,RES TRIANGLE PK,NC 27709. US DOE,MORGANTOWN ENERGY TECHNOL CTR,MORGANTOWN,WV 26507. NR 7 TC 19 Z9 23 U1 0 U2 1 PU BUTTERWORTH-HEINEMANN LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD, OXON, ENGLAND OX5 1GB SN 0950-4214 J9 GAS SEP PURIF JI Gas Sep. Purif. PD SEP PY 1994 VL 8 IS 3 BP 137 EP 147 DI 10.1016/0950-4214(94)80024-3 PG 11 WC Engineering, Chemical SC Engineering GA PB710 UT WOS:A1994PB71000002 ER PT J AU DAMLE, AS GANGWAL, SK VENKATARAMAN, VK AF DAMLE, AS GANGWAL, SK VENKATARAMAN, VK TI A SIMPLE-MODEL FOR A WATER-GAS SHIFT MEMBRANE REACTOR (VOL 8, PG 101, 1994) SO GAS SEPARATION & PURIFICATION LA English DT Correction, Addition C1 US DOE,MORGANTOWN ENERGY TECHNOL CTR,MORGANTOWN,WV 26507. RES TRIANGLE INST,RES TRIANGLE PK,NC 27709. NR 1 TC 0 Z9 0 U1 0 U2 0 PU BUTTERWORTH-HEINEMANN LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD, OXON, ENGLAND OX5 1GB SN 0950-4214 J9 GAS SEP PURIF JI Gas Sep. Purif. PD SEP PY 1994 VL 8 IS 3 BP 191 EP 191 PG 1 WC Engineering, Chemical SC Engineering GA PB710 UT WOS:A1994PB71000008 ER PT J AU CHENG, JF BOYARTCHUK, V ZHU, YW AF CHENG, JF BOYARTCHUK, V ZHU, YW TI ISOLATION AND MAPPING OF HUMAN-CHROMOSOME-21 CDNA - PROGRESS IN CONSTRUCTING A CHROMOSOME-21 EXPRESSION MAP SO GENOMICS LA English DT Article ID HUMAN GENOME PROJECT; TRANSCRIBED SEQUENCES; DNA; SELECTION; REGION; GENES; AMPLIFICATION; FRAGMENTS; STRATEGY; CLONING AB We have isolated 175 cDNA clones from a fetal brain library by direct cDNA selection using genomic DNA isolated from pools of human chromosome 21 (HC21) cosmids. DNA sequences have revealed that 16 of these cDNA clones contain overlapping sequences. Of the other 159 cDNA sequences, 10 match previously identified HC21 genes, and 9 match previously determined cDNA sequences, including the Wilms tumor related transcript (QM), the human testican cDNA, the mammalian calponin cDNA, and 6 anonymous expressed sequence tags. Ah isolated cDNAs were hybridized to their corresponding cosmids, which suggests that they originated from HC21. We have localized 92 cDNA clones to previously reported HC21q YACs. The remaining unmapped cDNAs contain either sequences not included in the isolated HC21q YACs or sequences that hybridize to yeast DNA. The cDNAs not included in the YACs should be useful in isolating new YACs to bridge the gaps. PCR primers were derived from 4 novel cDNA sequences that had been mapped to the YACs in the suspected Down syndrome region and used in RT-PCR analysis. All 4 primer sequences amplified RNA fragments with the expected sizes, suggesting that these sequences could be used for expression analysis. The construction of a chromosome 21 cDNA map not only is important in the refinement of physical maps, but also will identify a set of genes in the disease regions for detailed characterization. (C) 1994 Academic Press, Inc. RP CHENG, JF (reprint author), UNIV CALIF BERKELEY,LAWRENCE BERKELEY LAB,CTR HUMAN GENOME,1 CYCLOTRON RD,MS 74-157,BERKELEY,CA 94720, USA. NR 30 TC 92 Z9 94 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 0888-7543 J9 GENOMICS JI Genomics PD SEP 1 PY 1994 VL 23 IS 1 BP 75 EP 84 DI 10.1006/geno.1994.1461 PG 10 WC Biotechnology & Applied Microbiology; Genetics & Heredity SC Biotechnology & Applied Microbiology; Genetics & Heredity GA PG072 UT WOS:A1994PG07200010 PM 7829105 ER PT J AU MORRIS, DE CHISHOLMBRAUSE, CJ BARR, ME CONRADSON, SD ELLER, PG AF MORRIS, DE CHISHOLMBRAUSE, CJ BARR, ME CONRADSON, SD ELLER, PG TI OPTICAL SPECTROSCOPIC STUDIES OF THE SORPTION OF UO2(2+) SPECIES ON A REFERENCE SMECTITE SO GEOCHIMICA ET COSMOCHIMICA ACTA LA English DT Article ID HEMATITE PARTICLES; URANYL-ION; URANIUM; ADSORPTION; CLAY; COMPLEXES; ZEOLITES; SILICA AB The speciation of UO22+ (uranyl) on a reference smectite (SAz-1 from Cheto, Arizona, USA) has been investigated by electronic emission and Raman vibrational spectroscopies. The spectroscopic studies have been done on uranyl-bearing clays prepared from aqueous solutions of uranyl nitrate in the pH range from similar to 2.5 to 7 and high initial ionic strength (similar to 0.1-0.3 M). The uranyl loading levels in these samples ranged from similar to 0.1% to similar to 53% of the reported cation exchange capacity (similar to 1.2 meq/g). Vibronically resolved emission spectra have been obtained for all samples. These spectra vary significantly in intensity and band-shape as a function of uranyl concentration in the clays and the equilibrium pH of the solutions from which the clays were prepared. For most clay samples the measured emission spectrum is a composite of spectra from multiple uranyl emitters. At the lowest loading levels a uranyl sorption complex with an apparent vibronic spacing of similar to 750 cm(-1) dominates the spectra. At intermediate loading levels an additional uranyl sorption complex also having an apparent vibronic spacing of similar to 750 cm(-1) is present at an approximately constant concentration ratio to the species in the most dilute samples. At the highest loading levels, a uranyl sorption complex with a vibronic spacing of similar to 850 cm(-1) dominates the spectra. Raman spectra have been obtained for the more concentrated uranyl/clay samples. Two distinct bands (855 cm(-1) and 883 cm(-1)) are seen in the spectral region of the totally symmetric uranyl stretch. The 855 cm(-1) band correlates with the dominant high-coverage species, while the 883 cm(-1) band arises from an additional sorption complex. Comparison of these results with aqueous solution spectral data suggests that monomeric uranyl moieties are responsible for the observed spectral responses in the clay samples, and the multiple spectral components are a result of occupancy by these moieties in several structurally and/or energetically different sites within the clay. It is proposed that the uranyl species responsible for the dominant components in the emission spectra in the low and intermediate coverage clay sample are sorbed to amphoteric edge site(s). The uranyl species responsible for the dominant component in the emission spectrum and the 855 cm(-1) Raman band in the high-coverage clays is proposed to be exchanged into the fixed charge site(s). The additional complex identified by the Raman band at 883 cm(-1) is also proposed as a sorption complex at fixed-charge sites. C1 LOS ALAMOS NATL LAB,CTR MAT,LOS ALAMOS,NM 87545. RP MORRIS, DE (reprint author), LOS ALAMOS NATL LAB,DIV CHEM SCI & TECHNOL,POB 1663,LOS ALAMOS,NM 87545, USA. RI Morris, David/A-8577-2012 NR 44 TC 86 Z9 86 U1 1 U2 10 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD, ENGLAND OX5 1GB SN 0016-7037 J9 GEOCHIM COSMOCHIM AC JI Geochim. Cosmochim. Acta PD SEP PY 1994 VL 58 IS 17 BP 3613 EP 3623 DI 10.1016/0016-7037(94)90153-8 PG 11 WC Geochemistry & Geophysics SC Geochemistry & Geophysics GA PG266 UT WOS:A1994PG26600005 ER PT J AU CHISHOLMBRAUSE, C CONRADSON, SD BUSCHER, CT ELLER, PG MORRIS, DE AF CHISHOLMBRAUSE, C CONRADSON, SD BUSCHER, CT ELLER, PG MORRIS, DE TI SPECIATION OF URANYL SORBED AT MULTIPLE BINDING-SITES ON MONTMORILLONITE SO GEOCHIMICA ET COSMOCHIMICA ACTA LA English DT Article ID HEMATITE PARTICLES; CRYSTAL-CHEMISTRY; ADSORPTION; URANIUM; MINERALS; CLAY; SORPTION; SILICA; OXIDE; ION AB We have investigated the structures of U (VI) complexes as uranyl moieties sorbed onto a reference montmorillonite, SAz-1, using X-ray absorption fine structure spectroscopy (XAFS). The uranyl-loaded clays were prepared from aqueous solutions of uranyl nitrate in the pH range from 3.0 to 3.5. The U concentrations on the clay ranged from 1.7 to 34.6% of the reported cation exchange capacity (CEC = 1.2 meq/g) of the clay. For all samples, XAFS results indicate that there are two axial oxygen atoms at 1.78-1.80 Angstrom, as expected for the uranyl moiety. The average numbers and distances of equatorial oxygen atoms about uranyl sorbed on the clay vary significantly as a function of surface coverage. At high coverage (34.6% CEC), the average number and distance of equatorial oxygen atoms are near those found for the fully hydrated uranyl species in aqueous solution. However, there are fewer equatorial oxygen atoms at a shorter average distance about uranyl sorbed at low coverage (1.7% CEC). At moderate coverage (7.3% CEC), the average number and distance of equatorial oxygen atoms are intermediate between those at higher and lower coverage. These changes suggest that sorbing U is reacting with at least three different sites on the clay as U concentration increases. The existence of multiple surface sites and sorption complexes which are structurally distinct from solution species need to be considered for rigorous modeling of sorption processes. C1 LOS ALAMOS NATL LAB,DIV CHEM SCI & TECHNOL,LOS ALAMOS,NM 87545. LOS ALAMOS NATL LAB,DIV MAT SCI & TECHNOL,LOS ALAMOS,NM 87545. RI Morris, David/A-8577-2012 NR 37 TC 124 Z9 124 U1 4 U2 33 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD, ENGLAND OX5 1GB SN 0016-7037 J9 GEOCHIM COSMOCHIM AC JI Geochim. Cosmochim. Acta PD SEP PY 1994 VL 58 IS 17 BP 3625 EP 3631 DI 10.1016/0016-7037(94)90154-6 PG 7 WC Geochemistry & Geophysics SC Geochemistry & Geophysics GA PG266 UT WOS:A1994PG26600006 ER PT J AU RYERSON, FJ MCKEEGAN, KD AF RYERSON, FJ MCKEEGAN, KD TI DETERMINATION OF OXYGEN SELF-DIFFUSION IN AKERMANITE, ANORTHITE, DIOPSIDE, AND SPINEL - IMPLICATIONS FOR OXYGEN ISOTOPIC ANOMALIES AND THE THERMAL HISTORIES OF CA-AL-RICH INCLUSIONS SO GEOCHIMICA ET COSMOCHIMICA ACTA LA English DT Article ID ALLENDE METEORITE; SINGLE-CRYSTALS; ION MICROPROBE; ELEMENT DISTRIBUTION; WATER FUGACITY; COOLING RATE; ORIGIN; MELILITE; COEFFICIENTS; TEMPERATURE AB Oxygen self-diffusion coefficients have been measured for three natural diopsidic clinopyroxenes, a natural anorthite, a synthetic magnesium aluminate spinel. and a synthetic akermanite for oxygen fugacities ranging from the NNO to IW buffers. The experiments employed a gas-solid isotopic exchange technique utilizing 99% O-18-enriched CO-CO2 gas mixtures to control both the oxygen fugacity and the isotopic composition of the exchange reservoir. Diffusion profiles of the O-18 tracer were obtained by in-depth analysis with an ion microprobe. The experimental results, fit to the Arrhenius relation D = D(0)e((-Q/RT)), yield the following: D-degrees(m(2) s(-1)) Q(kJ mol(-1)) diopside 4.3[-3.8 +32.6] x 10(-4) 457 +/- 26 akermanite 4.7[-4.4 +83.5] x 10(-7) 278 +/- 33 spinel 2.2[-1.8 +8.7] x 10(-7) 404 +/- 21 anorthite 8.4[-8.0 +174] x 10(-13) 162 +/- 36 At a given temperature, oxygen diffuses about 100 times more slowly in diopside than indicated by previous bulk-exchange experiments (CONNOLLY and MUEHLENBACHS, 1988). Our data for anorthite, spinel, and akermanite agree well with prior results obtained by gas-solid exchange and depth profiling methods (ELPHICK et al., 1988; REDDY and COOPER, 1981; YURIMOTO et al., 1989, respectively). Since these other experiments were conducted at different oxygen fugacities, this agreement indicates that diffusion of oxygen in these nominally Fe-free minerals is not greatly affected by f(o2) in the range between pure oxygen and the iron-wustite buffer. However, our diffusion coefficients for anorthite, melilite, and spinel are also uniformly lower than those obtained by bulk analysis of crushed powders at similar temperatures (MUEHLENBACHS and KUSHIRO, 1974; HAYASHI and MUEHLENBACHS, 1986; ANDO and OISHI, 1974). The oxygen diffusion data are used to evaluate the effects of three different types of thermal histories upon the oxygen isotopic compositions of minerals found in Type B Ca-Al-rich inclusions (CAIBs) in carbonaceous chondrites: (1) gas-solid exchange during isothermal heating, (2) gas-solid exchange as a function of cooling rate subsequent to instantaneous heating, and (3) isotopic exchange with a gaseous reservoir during partial melting and recrystallization. With the assumptions that the mineral compositions within a CAIB were uniformly enriched in O-16 prior to any thermal processing, that effective diffusion dimensions may be estimated from observed grain sizes, and that diffusion in diopside is similar to that in fassaitic clinopyroxene, none of the above scenarios can reproduce the relative oxygen isotopic anomalies observed in CAIBs without improbably long or unrealistically intense thermal histories relative to current theoretical models of nebular evolution. The failure of these simple models, coupled with recent observations of ''disturbed'' magnesium isotopic abundances and correlated petrographic features in anorthite and melilite indicative of alteration and recrystallization, suggests that the oxygen isotopic compositions of these phases may have also been modified by alteration and recrystallization possibly interspersed with multiple melting events. Because the modal abundance of spinel remains relatively constant for plausible melting scenarios, and its relatively sluggish diffusion kinetics prevent substantial equilibration, Mg-AI spinel is the most reliable indicator of the oxygen isotopic composition of precursor material which formed Type B CAIs. C1 UNIV CALIF LOS ANGELES,DEPT EARTH & SPACE SCI,LOS ANGELES,CA 90024. RP RYERSON, FJ (reprint author), LAWRENCE LIVERMORE NATL LAB,INST GEOPHYS & PLANETARY PHYS,LIVERMORE,CA 94602, USA. RI McKeegan, Kevin/A-4107-2008 OI McKeegan, Kevin/0000-0002-1827-729X NR 73 TC 117 Z9 118 U1 2 U2 11 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD, ENGLAND OX5 1GB SN 0016-7037 J9 GEOCHIM COSMOCHIM AC JI Geochim. Cosmochim. Acta PD SEP PY 1994 VL 58 IS 17 BP 3713 EP 3734 DI 10.1016/0016-7037(94)90161-9 PG 22 WC Geochemistry & Geophysics SC Geochemistry & Geophysics GA PG266 UT WOS:A1994PG26600013 ER PT J AU VANIMAN, DT CHIPERA, SJ BISH, DL AF VANIMAN, DT CHIPERA, SJ BISH, DL TI PEDOGENESIS OF SILICEOUS CALCRETES AT YUCCA MOUNTAIN, NEVADA SO GEODERMA LA English DT Article ID MORPHOLOGY; CALCITE; AUSTRALIA; GENESIS; ORIGIN; SOILS; USA AB Siliceous calcretes in faults near Yucca Mountain, Nevada, have been interpreted by some observers as evidence of seismically-triggered eruptions of deep water. Such an origin could have important consequences if Yucca Mountain is developed as an unsaturated site for disposal of high-level nuclear waste. At odds with this hypothesis are the absence of features that should be present at fault-fed springs (e.g., fissure-ridge mounds with microterraces) and the preservation within root casts of delicate pedogenic microfossils such as calcified filaments and needle-fiber calcites. Chemical evidence of pedogenic origin is found in Fe and Sc enrichments that require prior weathering of detritus in the calcretes, as opposed to direct incorporation of adjacent unweathered bedrock. Carbonate and silica abundances and accumulation rates are well within the scope of pedogenic processes. Sources of carbonate are eolian, whereas silica is derived in part by dissolution of local volcanic glasses but also by extensive dissolution of unstable silica minerals (tridymite and cristobalite) that are abundant in the local tuffs. The siliceous calcretes at Yucca Mountain are pedogenic and provide no evidence in support of conjectured spring activity. RP VANIMAN, DT (reprint author), LOS ALAMOS NATL LAB,MS D462,LOS ALAMOS,NM 87545, USA. NR 35 TC 19 Z9 19 U1 0 U2 4 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0016-7061 J9 GEODERMA JI Geoderma PD SEP PY 1994 VL 63 IS 1 BP 1 EP 17 DI 10.1016/0016-7061(94)90106-6 PG 17 WC Soil Science SC Agriculture GA PH569 UT WOS:A1994PH56900001 ER PT J AU ODA, H HIRAO, J SUZUKI, I VISSCHER, WM ANDERSON, OL AF ODA, H HIRAO, J SUZUKI, I VISSCHER, WM ANDERSON, OL TI FREE OSCILLATIONS OF ELASTICALLY ANISOTROPIC SPHERES AND ELLIPSOIDS SO GEOPHYSICAL JOURNAL INTERNATIONAL LA English DT Article DE ANISOTROPY; ELASTODYNAMICS; FREE OSCILLATIONS; PERTURBATION METHODS ID RESONANCE METHOD; CRYSTAL; EARTH; CONSTANTS AB The free oscillations of elastically anisotropic spheres are computed here using a Rayleigh-Ritz method developed by Mochizuki (1988). The computation of eigenfrequencies was made for elastic spheres with orthorhombic, tetragonal, cubic and isotropic crystal symmetries, and how the degenerate eigenfrequencies split due to the elastic anisotropy has been shown. A perturbation theory combined with the Rayleigh-Ritz method was presented to compute shifts in and splits of eigenfrequencies due to deformation of an elastic sphere into an ellipsoid. The frequency shifts are expressed by delta omega = Phi(x) epsilon(x) + Phi(y) epsilon(y) + Phi(z) epsilon(z), where epsilon(j) and Phi(j) (j = x, y, z) are, respectively, asphericities and aspherical coefficients of the ellipsoid. This equation was used not only to compute the free-oscillation frequencies of an elastically anisotropic ellipsoid, but also to determine the asphericities of an olivine ellipsoid from observed resonant frequencies. C1 LOS ALAMOS NATL LAB,LOS ALAMOS,NM 87545. UNIV CALIF LOS ANGELES,INST GEOPHYS & PLANETARY PHYS,LOS ANGELES,CA 90024. RP ODA, H (reprint author), OKAYAMA UNIV,FAC SCI,DEPT EARTH SCI,OKAYAMA 700,JAPAN. NR 26 TC 3 Z9 3 U1 1 U2 1 PU BLACKWELL SCIENCE LTD PI OXFORD PA OSNEY MEAD, OXFORD, OXON, ENGLAND OX2 0EL SN 0956-540X J9 GEOPHYS J INT JI Geophys. J. Int. PD SEP PY 1994 VL 118 IS 3 BP 555 EP 565 DI 10.1111/j.1365-246X.1994.tb03984.x PG 11 WC Geochemistry & Geophysics SC Geochemistry & Geophysics GA PG500 UT WOS:A1994PG50000006 ER PT J AU FARGES, F BROWN, GE CALAS, G GALOISY, L WAYCHUNAS, GA AF FARGES, F BROWN, GE CALAS, G GALOISY, L WAYCHUNAS, GA TI STRUCTURAL TRANSFORMATION IN NI-BEARING NA2SI2O5 GLASS AND MELT SO GEOPHYSICAL RESEARCH LETTERS LA English DT Article ID TRANSITION-METAL IONS; X-RAY ABSORPTION; HIGH-TEMPERATURE; SILICATE MELTS; NICKEL; LIQUID; COORDINATION; SYSTEMS; ENVIRONMENT; OLIVINE AB The coordination environment around Ni at minor concentration levels (2 wt. % NiO) in Na2Si2O5 glass and melt (293-1250K) has been investigated by Ni K-edge X-ray Absorption Fine Structure (XAFS) spectroscopy. X-ray Absorption Near Edge Structure (XANES) spectra indicate that both (IV)Ni and (V)Ni occur in the glass, whereas (IV)Ni is dominant in the melt. The average anharmonic Ni-O distances derived from XAFS spectra of the glass at 293 K and the melt above 1150 K are 2.00 (+/- 0.02) and 1.97 (+/- 0.02) angstrom, respectively. The Ni-O distance in the glass is consistent with a mixture of (IV)Ni and (V)Ni, whereas that in the melt is consistent with dominantly (IV)Ni, suggesting a Ni-coordination change during glass melting. This major change in Ni coordination indicates significant reorganization of the melt during quenching and crystallization. These observations for a compositionally-simple melt/glass system may help explain the enrichment of Ni in early-formed igneous minerals. They also suggest the possibility of a pressure-induced coordination change around Ni in the mantle which may influence geochemical modeling of the deep Earth. C1 STANFORD UNIV,DEPT GEOL & ENVIRONM SCI,STANFORD,CA 94305. UNIV PARIS 06,MINERAL CRISTALL LAB,F-75252 PARIS 05,FRANCE. STANFORD UNIV,CTR MAT RES,STANFORD,CA 94305. STANFORD UNIV,STANFORD SYNCHROTRON RADIAT LAB,STANFORD,CA 94305. UNIV PARIS 07,F-75252 PARIS 05,FRANCE. IPGP,CNRS, URA 09,F-75252 PARIS 05,FRANCE. UNIV MARNE LA VALLEE,IPGP,PHYS & MECAN GEOMAT LAB,NOISY LE GRAND,FRANCE. CNRS,URA 734,NOISY LE GRAND,FRANCE. RI Calas, Georges/B-2445-2012 OI Calas, Georges/0000-0003-0525-5734 NR 22 TC 31 Z9 31 U1 0 U2 6 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 SN 0094-8276 J9 GEOPHYS RES LETT JI Geophys. Res. Lett. PD SEP 1 PY 1994 VL 21 IS 18 BP 1931 EP 1934 DI 10.1029/94GL01079 PG 4 WC Geosciences, Multidisciplinary SC Geology GA PE824 UT WOS:A1994PE82400002 ER PT J AU PIZZO, VJ GOSLING, JT AF PIZZO, VJ GOSLING, JT TI 3-D SIMULATION OF HIGH-LATITUDE INTERACTION REGIONS - COMPARISON WITH ULYSSES RESULTS SO GEOPHYSICAL RESEARCH LETTERS LA English DT Article ID SOLAR-WIND STREAM; SECTOR STRUCTURE; EVOLUTION AB A three-dimensional (3-D) magnetohydrodynamic (MHD) numerical model is used to stimulate the global evolution of a steady, tilted-dipole solar wind flow configuration similar to that prevalent in interplanetary space in 1993. Systematic latitudinal changes in the structure of a corotating interaction region (CIR) near 5 AU is shown to agree well with recent Ulysses observations. The abrupt disappearance of forward shocks and continued persistence of reverse shocks poleward of the latitude where Ulysses crossed the southern edge of the coronal streamer belt is explained as a natural consequence of the 3-D flow geometry. C1 NOAA,SEL,BOULDER,CO 80303. LOS ALAMOS NATL LAB,LOS ALAMOS,NM 87545. RP PIZZO, VJ (reprint author), SAN JUAN INST,SAN JUAN,CA, USA. NR 12 TC 62 Z9 62 U1 0 U2 1 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 SN 0094-8276 J9 GEOPHYS RES LETT JI Geophys. Res. Lett. PD SEP 1 PY 1994 VL 21 IS 18 BP 2063 EP 2066 DI 10.1029/94GL01581 PG 4 WC Geosciences, Multidisciplinary SC Geology GA PE824 UT WOS:A1994PE82400035 ER PT J AU BJERSTEDT, TW AF BJERSTEDT, TW TI WHATS NEW AT YUCCA MOUNTAIN SO GEOTIMES LA English DT Article RP BJERSTEDT, TW (reprint author), US DOE,YUCCA MT SITE CHARACTERIZAT OFF,101 CONVENT CTR DR,LAS VEGAS,NV 89109, USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU AMER GEOLOGICAL INST PI ALEXANDRIA PA 4220 KING ST, ALEXANDRIA, VA 22302-1507 SN 0016-8556 J9 GEOTIMES JI Geotimes PD SEP PY 1994 VL 39 IS 9 BP 18 EP 20 PG 3 WC Geosciences, Multidisciplinary SC Geology GA PQ633 UT WOS:A1994PQ63300007 ER PT J AU BROECKER, WS PENG, TH AF BROECKER, WS PENG, TH TI STRATOSPHERIC CONTRIBUTION TO THE GLOBAL BOMB RADIOCARBON INVENTORY - MODEL VERSUS OBSERVATION SO GLOBAL BIOGEOCHEMICAL CYCLES LA English DT Article ID ATMOSPHERIC CARBON-DIOXIDE; SECULAR VARIATIONS; ISOTOPIC-RATIOS; CO2; OCEAN; C-14; ABUNDANCE AB An attempt is made, through modeling, to account for the decline in the C-14/C ratio in atmospheric CO2 after its bomb-test-induced peak in 1963. The model suggests that as of 1964 about one third of the bomb C-14 remained in the stratosphere and that it was released to the troposphere with an e-folding time of about seven years. By contrast, measurements carried out in the stratosphere suggest that at that time the excess was closer to one quarter of the total and that the e-folding time for its decline was 3 +/- 1 years. The anomaly between model and observation cannot be attributed solely to an inadequacy in the representation of the terrestrial biosphere. Rather, it must reflect either an inadequacy in the ocean model or in the measured stratospheric inventories. C1 OAK RIDGE NATL LAB, DIV ENVIRONM SCI, OAK RIDGE, TN 37831 USA. RP BROECKER, WS (reprint author), COLUMBIA UNIV, LAMONT DOHERTY EARTH OBSERV, PALISADES, NY 10964 USA. NR 24 TC 34 Z9 34 U1 0 U2 4 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 0886-6236 EI 1944-9224 J9 GLOBAL BIOGEOCHEM CY JI Glob. Biogeochem. Cycle PD SEP PY 1994 VL 8 IS 3 BP 377 EP 384 DI 10.1029/94GB00680 PG 8 WC Environmental Sciences; Geosciences, Multidisciplinary; Meteorology & Atmospheric Sciences SC Environmental Sciences & Ecology; Geology; Meteorology & Atmospheric Sciences GA PE619 UT WOS:A1994PE61900010 ER PT J AU ISTOK, JD RAUTMAN, CA FLINT, LE FLINT, AL AF ISTOK, JD RAUTMAN, CA FLINT, LE FLINT, AL TI SPATIAL VARIABILITY IN HYDROLOGIC PROPERTIES OF A VOLCANIC TUFF SO GROUND WATER LA English DT Article ID SOIL AB Spatial variability of hydrologic properties was quantified for a nonwelded-to-welded ash flow tuff at Yucca Mountain, Nevada, the potential site of a high-level, nuclear waste repository. Bulk density, porosity, saturated hydraulic conductivity, and sorptivity were measured on core specimens collected from outcrops on a grid that extended vertically through the entire unit thickness and horizontally 1.3 km in the direction of ash transport from the volcanic vent, A strong, geologically determined (deterministic) vertical trend in properties was apparent that correlated with visual trends in degree of welding observed in the outcrop. The trend was accurately described by simple regression models based on stratigraphic elevation (vertical distance from the base of the unit divided by unit thickness). No significant horizontal trends in properties were detected along the length of the transect. The validity of the developed model was tested by comparing model predictions with measured porosity values from additional outcrop sections and boreholes that extended 3000 m north, 1500 m northeast, and 6000 m south of the study area. The model accurately described vertical porosity variations except for locations very close to the source caldera, where the model underpredicted porosity in the upper half of the section. The presence of deterministic geologic trends, such as those demonstrated for an ash flow unit in this study, can simplify the collection of site characterization data and the development of site-scale models. C1 SANDIA NATL LABS,DEPT GEOSCI ASSESSMENT & VALIDAT,ALBUQUERQUE,NM 87185. US GEOL SURVEY,HYDROL RES FACIL,MERCURY,NV 89023. RAYTHEON SERV NEVADA,HYDROL RES FACIL,MERCURY,NV 89023. RP ISTOK, JD (reprint author), OREGON STATE UNIV,DEPT CIVIL ENGN,CORVALLIS,OR 97331, USA. NR 27 TC 12 Z9 12 U1 1 U2 3 PU GROUND WATER PUBLISHING CO PI WESTERVILLE PA 601 DEMPSEY RD, WESTERVILLE, OH 43081 SN 0017-467X J9 GROUND WATER JI Ground Water PD SEP-OCT PY 1994 VL 32 IS 5 BP 751 EP 760 DI 10.1111/j.1745-6584.1994.tb00916.x PG 10 WC Geosciences, Multidisciplinary; Water Resources SC Geology; Water Resources GA PE981 UT WOS:A1994PE98100007 ER PT J AU BJORNSTAD, BN MCKINLEY, JP STEVENS, TO RAWSON, SA FREDERICKSON, JK LONG, PE AF BJORNSTAD, BN MCKINLEY, JP STEVENS, TO RAWSON, SA FREDERICKSON, JK LONG, PE TI GENERATION OF HYDROGEN GAS A RESULT OF DRILLING WITHIN THE SATURATED ZONE SO GROUND WATER MONITORING AND REMEDIATION LA English DT Article AB Hydrogen gas was discovered within the steel casing above standing water in a percussion-drilled borehole on the Hanford Site in south-central Washington state. In situ measurements of the borehole fluids indicated anoxic, low-Eh (<-400 mV) conditions. Ground water sampled from adjacent wells in the same formation indicated that the ground water was oxygenated. H2 was generated during percussion drilling, due to the decomposition of borehole waters as a result of aqueous reactions with drilled sediment and steel from the drilling tools or casing. The generation of H2 within percussion-drilled boreholes that extend below the water table may be more common than previously realized. The ambient concentration of H2 produced during drilling was limited by microbial activity within the casing-resident fluids. H2 was generated abiotically in the laboratory, whereby sterilized borehole slurry samples produced 100 times more H2 than unsterilized samples. It appears that H2 is metabolized by microorganisms and concentrations might be significantly greater if not for microbial metabolism. RP BJORNSTAD, BN (reprint author), PACIFIC NW LAB, GEOL & GEOPHYS GRP, POB 999, RICHLAND, WA 99352 USA. RI Long, Philip/F-5728-2013 OI Long, Philip/0000-0003-4152-5682 NR 0 TC 13 Z9 13 U1 0 U2 3 PU GROUND WATER PUBLISHING CO PI WESTERVILLE PA 601 DEMPSEY RD, WESTERVILLE, OH 43081 SN 1069-3629 J9 GROUND WATER MONIT R JI Ground Water Monit. Remediat. PD FAL PY 1994 VL 14 IS 4 BP 140 EP 147 DI 10.1111/j.1745-6592.1994.tb00492.x PG 8 WC Water Resources SC Water Resources GA PN479 UT WOS:A1994PN47900008 ER PT J AU KEARL, PM KORTE, NE STITES, M BAKER, J AF KEARL, PM KORTE, NE STITES, M BAKER, J TI FIELD COMPARISON OF MICROPURGING VS TRADITIONAL GROUND-WATER SAMPLING SO GROUND WATER MONITORING AND REMEDIATION LA English DT Article AB Micropurge sampling of ground water wells has been suggested as a possible replacement to traditional purge and sample methods. To compare methods, duplicate ground water samples were collected at two field sites using traditional and micropurge methods. Samples were analyzed for selected organic and inorganic constituents, and the results were compared statistically. Analysis of the data using the nonparametric sign test indicates that within a 95 percent confidence interval, there was no significant difference between the two methods for the site contaminants and the majority of analytes. These analytical results were supported by visual observations with the colloidal borescope, which demonstrated impacts on the flow system in the well when using traditional sampling methods. Under selected circumstances, the results suggest replacing traditional sampling with micropurging based on reliability, cost, and waste minimization. RP KEARL, PM (reprint author), OAK RIDGE NATL LAB,DIV ENVIRONM SCI,GRAND JUNCT OFF,GRAND JCT,CO 81502, USA. NR 0 TC 24 Z9 26 U1 0 U2 2 PU GROUND WATER PUBLISHING CO PI WESTERVILLE PA 601 DEMPSEY RD, WESTERVILLE, OH 43081 SN 1069-3629 J9 GROUND WATER MONIT R JI Ground Water Monit. Remediat. PD FAL PY 1994 VL 14 IS 4 BP 183 EP 190 DI 10.1111/j.1745-6592.1994.tb00496.x PG 8 WC Water Resources SC Water Resources GA PN479 UT WOS:A1994PN47900012 ER PT J AU KALB, PD NEWTON, AS AF KALB, PD NEWTON, AS TI ENCAPSULATION OF HAZARDOUS-WASTE USING MODIFIED SULFUR CEMENT SO HAZARDOUS WASTE CONSULTANT LA English DT Article C1 ON LINE RECLAMAT LTD,OKLAHOMA CITY,OK 73154. RP KALB, PD (reprint author), BROOKHAVEN NATL LAB,CTR ENVIRONM & WASTE TECHNOL,UPTON,NY 11973, USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU ELSEVIER SCIENCE INC PI NEW YORK PA 655 AVENUE OF THE AMERICAS, NEW YORK, NY 10010 SN 0738-0232 J9 HAZARDOUS WASTE CONS JI Hazard. Waste Consult. PD SEP-OCT PY 1994 VL 12 IS 5 BP A29 EP A30 PG 2 WC Engineering, Environmental SC Engineering GA PH703 UT WOS:A1994PH70300011 ER PT J AU HUI, TE LOESCH, RM RADDATZ, C FISHER, DR MCDONALD, JC AF HUI, TE LOESCH, RM RADDATZ, C FISHER, DR MCDONALD, JC TI AN INTERNAL DOSIMETRY INTERCOMPARISON STUDY SO HEALTH PHYSICS LA English DT Article DE BIOASSAY; DOSE ASSESSMENT; DOSIMETRY; DOSE, INTERNAL AB Pacific Northwest Laboratory performed a study to evaluate the consistency of internal dosimetry assessments. A total of eleven laboratories, including DOE sites and NRC licensees, participated in this intercomparison study. Participants were asked to respond to five actual exposure scenarios, previously used in a similar European study. The participating dosimetrists assessed the data of the test scenarios and calculated results in terms of estimated radionuclide intake and the resulting internal doses. To maintain confidentiality, results are given without identifying any site. Except for one scenario, the results showed that the standard deviation of the final results on committed effective dose equivalent for each exposure scenario was about 30-50% of the mean value, giving a consistency slightly greater variant than that of the European study. The discrepancies can be attributed to variations in 1) the interpretation and statistical treatment of the bioassay data; 2) the biokinetic models applied; and 3) the computational tools used. This represents a preliminary study; further intercomparison testing is needed to fully evaluate the problem of dose-assessment inconsistency. C1 US DOE, WASHINGTON, DC 20585 USA. US NUCL REGULATORY COMMISS, WASHINGTON, DC 20555 USA. RP HUI, TE (reprint author), PACIFIC NW LAB, DEPT HLTH PHYS, RICHLAND, WA 99352 USA. NR 13 TC 13 Z9 13 U1 0 U2 0 PU LIPPINCOTT WILLIAMS & WILKINS PI PHILADELPHIA PA 530 WALNUT ST, PHILADELPHIA, PA 19106-3621 USA SN 0017-9078 EI 1538-5159 J9 HEALTH PHYS JI Health Phys. PD SEP PY 1994 VL 67 IS 3 BP 217 EP 225 DI 10.1097/00004032-199409000-00001 PG 9 WC Environmental Sciences; Public, Environmental & Occupational Health; Nuclear Science & Technology; Radiology, Nuclear Medicine & Medical Imaging SC Environmental Sciences & Ecology; Public, Environmental & Occupational Health; Nuclear Science & Technology; Radiology, Nuclear Medicine & Medical Imaging GA PC297 UT WOS:A1994PC29700001 PM 8056587 ER PT J AU CARLTON, WH MURPHY, CE EVANS, AG AF CARLTON, WH MURPHY, CE EVANS, AG TI RADIOCESIUM IN THE SAVANNA RIVER SITE ENVIRONMENT SO HEALTH PHYSICS LA English DT Article DE CESIUM; CONTAMINATION, ENVIRONMENTAL; DOSE; WATER AB The Savannah River Site has produced plutonium, tritium, and other special nuclear materials for national defense, other government programs, and some civilian purposes. Radiocesium, a waste product, has been released to the environment during the operation of five reactors, two radiochemical processing facilities, and a high-level waste storage system. During the period 1955-1989, 130 GBq of Cs-137 was released to the atmosphere and 2.2 x 10(4) GBq was released to site streams and ponds. Approximately 65% of the latter remained on the site. The maximum individual effective dose equivalent at the site boundary was estimated to be 3.3 mu SY from atmospheric releases and 600 mu Sv from liquid releases. The 80-km population dose was 1.6 person-Sv. RP CARLTON, WH (reprint author), WESTINGHOUSE SAVANNAH RIVER CO, SAVANNAH RIVER TECHNOL CTR, AIKEN, SC 29808 USA. NR 20 TC 9 Z9 9 U1 0 U2 2 PU LIPPINCOTT WILLIAMS & WILKINS PI PHILADELPHIA PA 530 WALNUT ST, PHILADELPHIA, PA 19106-3621 USA SN 0017-9078 EI 1538-5159 J9 HEALTH PHYS JI Health Phys. PD SEP PY 1994 VL 67 IS 3 BP 233 EP 244 DI 10.1097/00004032-199409000-00003 PG 12 WC Environmental Sciences; Public, Environmental & Occupational Health; Nuclear Science & Technology; Radiology, Nuclear Medicine & Medical Imaging SC Environmental Sciences & Ecology; Public, Environmental & Occupational Health; Nuclear Science & Technology; Radiology, Nuclear Medicine & Medical Imaging GA PC297 UT WOS:A1994PC29700003 PM 8056589 ER PT J AU MUNYON, WJ KRETZ, ND MARCHETTI, FP AF MUNYON, WJ KRETZ, ND MARCHETTI, FP TI DESIGN, CALIBRATION, AND OPERATION OF RN-220 STACK EFFLUENT MONITORING SYSTEMS AT ARGONNE-NATIONAL-LABORATORY SO HEALTH PHYSICS LA English DT Article DE RN-220; EFFLUENTS; EMISSIONS, ATMOSPHERIC; RADIOACTIVITY, AIRBORNE AB A group of stack effluent monitoring systems have been developed to monitor discharges of Rn-220 from a hot cell facility at Argonne National Laboratory. The stack monitors use dow-through scintillation cells and are completely microprocessor-based systems. A method for calibrating the stack monitors in the laboratory and in the field is described. A nominal calibration factor for the stack monitoring systems in use is 15.0 cts min(-1) per kBq m(-3) (0.56 cts min(-1) per pCi L(-1)) +/- 26% at the 95% confidence level. The plate-out fraction of decay products in the stack monitor scintillation cells, without any pre-filtering, was found to be nominally 25% under normal operating conditions. When the sample was pre-filtered upstream of the scintillation cell, the observed cell plate-out fraction ranged from 16-22%, depending on the specific sampling conditions. The instantaneous Rn-220 stack concentration can be underestimated or overestimated when the steady state condition established between Rn-220 and its decay products in the scintillation cell is disrupted by sudden changes in the monitored Rn-220 concentration. For long-term measurements, however, the time-averaged response of the monitor represents the steady state condition and leads to a reasonable estimate of the average Rn-220 concentration during the monitoring period. RP MUNYON, WJ (reprint author), ARGONNE NATL LAB, DIV ENVIRONM SAFETY & HLTH, HLTH PHYS SURVEILLANCE & SUPPORT SECT, ARGONNE, IL 60439 USA. NR 5 TC 0 Z9 0 U1 0 U2 0 PU LIPPINCOTT WILLIAMS & WILKINS PI PHILADELPHIA PA 530 WALNUT ST, PHILADELPHIA, PA 19106-3621 USA SN 0017-9078 EI 1538-5159 J9 HEALTH PHYS JI Health Phys. PD SEP PY 1994 VL 67 IS 3 BP 290 EP 296 DI 10.1097/00004032-199409000-00013 PG 7 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 PC297 UT WOS:A1994PC29700013 PM 8056599 ER PT J AU GILLAN, DJ LEWIS, R AF GILLAN, DJ LEWIS, R TI A COMPONENTIAL MODEL OF HUMAN INTERACTION WITH GRAPHS .1. LINEAR-REGRESSION MODELING SO HUMAN FACTORS LA English DT Article ID PERCEPTION; DISPLAYS AB Task analyses served as the basis for developing the Mixed Arithmetic-Perceptual (MA-P) model, which proposes (1) that people interacting with common graphs to answer common questions apply a set of component processes-searching for indicators, encoding the value of indicators, performing arithmetic operations on the values, making spatial comparisons among the indicators, and responding; and (2) that the type of graph and user's task determine the combination and order of the components applied (i.e., the processing steps). Two experiments investigated the prediction that response time will be linearly related to the number of processing steps according to the MA-P model. Subjects used line graphs, scatter plots, and stacked bar graphs to answer comparison questions and questions requiring arithmetic calculations. A one-parameter version of the model (with equal weights for all components) and a two-parameter version (with different weights for arithmetic and nonarithmetic processes) accounted for 76%-85% of individual subjects' variance in response time and 61%-68% of the variance taken across all subjects. The discussion addresses possible modifications in the MA-P model, alternative models, and design implications from the MA-P model. C1 UNIV IDAHO, MOSCOW, ID 83843 USA. PACIFIC NW LAB, RICHLAND, WA 99352 USA. NR 34 TC 32 Z9 33 U1 0 U2 2 PU HUMAN FACTORS SOC PI SANTA MONICA PA BOX 1369, SANTA MONICA, CA 90406 SN 0018-7208 J9 HUM FACTORS JI Hum. Factors PD SEP PY 1994 VL 36 IS 3 BP 419 EP 440 PG 22 WC Behavioral Sciences; Engineering, Industrial; Ergonomics; Psychology, Applied; Psychology SC Behavioral Sciences; Engineering; Psychology GA PL892 UT WOS:A1994PL89200003 PM 7989050 ER PT J AU WARD, OG MILLER, RL JOHNSON, EH LUCAS, JN MEYNE, J AF WARD, OG MILLER, RL JOHNSON, EH LUCAS, JN MEYNE, J TI IDENTIFICATION OF TRISOMY IN MACACA-FASCICULARIS BY FLUORESCENCE IN-SITU HYBRIDIZATION WITH A HUMAN-CHROMOSOME-13 DNA LIBRARY SO HUMAN GENETICS LA English DT Article ID INSITU SUPPRESSION HYBRIDIZATION; FUSCATA CHROMOSOMES; RHESUS-MONKEY; HOMOLOGIES; MULATTA; APES AB A juvenile macaque monkey with abnormal phenotypic and behavioral features was studied cytogenetically. An additional autosome was found in over 90% of the animal's cultured cells. This chromosome, subsequently identified as number 16 in the macaque karyotype by G-banding, was shown to be mostly homologous with human chromosome 13 using fluorescence in situ hybridization of a human chromosome specific cosmid library. Although the monkey, now deceased, exhibited some abnormal physical and behavioral features, none of the severe clinical characteristics associated with human chromosome 13 trisomy were apparent. We suggest that the incomplete expression of 13-trisomy observed could result if the macaque chromosome were deficient in some of the region(s) of chromosome 13 common to humans affected with the disorder. C1 NEW MEXICO REG PRIMATE RES LAB,HOLLOMAN AFB,NM 88330. LAWRENCE LIVERMORE NATL LAB,LIVERMORE,CA 94551. LOS ALAMOS NATL LAB,DIV LIFE SCI,LOS ALAMOS,NM 87545. RP WARD, OG (reprint author), UNIV ARIZONA,DEPT ECOL & EVOLUTIONARY BIOL,TUCSON,AZ 85721, USA. NR 29 TC 7 Z9 7 U1 0 U2 0 PU SPRINGER VERLAG PI NEW YORK PA 175 FIFTH AVE, NEW YORK, NY 10010 SN 0340-6717 J9 HUM GENET JI Hum. Genet. PD SEP PY 1994 VL 94 IS 3 BP 247 EP 251 PG 5 WC Genetics & Heredity SC Genetics & Heredity GA PD329 UT WOS:A1994PD32900006 PM 8076939 ER PT J AU BONALDO, MD YU, MT JELENC, P BROWN, S SU, L LAWTON, L DEAVEN, L EFSTRATIADIS, A WARBURTON, D SOARES, MB AF BONALDO, MD YU, MT JELENC, P BROWN, S SU, L LAWTON, L DEAVEN, L EFSTRATIADIS, A WARBURTON, D SOARES, MB TI SELECTION OF CDNAS USING CHROMOSOME-SPECIFIC GENOMIC CLONES - APPLICATION TO HUMAN-CHROMOSOME-13 SO HUMAN MOLECULAR GENETICS LA English DT Article ID GLYCERALDEHYDE-3-PHOSPHATE DEHYDROGENASE GENE; ALPHA-TUBULIN; INSITU HYBRIDIZATION; COMPLETE SEQUENCE; PROTEIN HMG-1; DNA; EXPRESSION; FAMILY; MOUSE; IDENTIFICATION AB We have developed a general method for an masse isolation of cDNAs present in a normalized library by hybridization to arrayed chromosome-specific phage lambda clones; we have used this approach to initiate exon-mapping of human chromosome 13. An advantage of the simultaneous isolation of cDNA/lambda pairs is that it allows cytogenetic assignment of a bona fide genomic clone by in situ hybdridization, which also verifies that the corresponding cDNA or a homologous expressed sequence resides on chromosome 13. This information is enriched by partial sequencing of a selected cDNA from both ends. The sequence of the 3' noncoding region provides an 'identifier' that is used to develop STSs, while the sequence from the 5' end, often corresponding to a coding region, is used for homology searches in databases that occasionally reveal gene functions. C1 COLUMBIA UNIV,DEPT PSYCHIAT,NEW YORK,NY 10032. COLUMBIA UNIV,DEPT GENET & DEV,NEW YORK,NY 10032. COLUMBIA UNIV,DEPT OBSTET & GYNECOL,NEW YORK,NY 10032. NEW YORK STATE PSYCHIAT INST & HOSP,NEW YORK,NY 10032. LOS ALAMOS NATL LAB,CTR HUMAN GENOME STUDIES,LOS ALAMOS,NM 87545. FU NCRR NIH HHS [2 S07 RR05395-30]; NHGRI NIH HHS [5R01 HG00362]; NICHD NIH HHS [1R55HD28422] NR 55 TC 27 Z9 27 U1 0 U2 0 PU OXFORD UNIV PRESS UNITED KINGDOM PI OXFORD PA WALTON ST JOURNALS DEPT, OXFORD, ENGLAND OX2 6DP SN 0964-6906 J9 HUM MOL GENET JI Hum. Mol. Genet. PD SEP PY 1994 VL 3 IS 9 BP 1663 EP 1673 PG 11 WC Biochemistry & Molecular Biology; Genetics & Heredity SC Biochemistry & Molecular Biology; Genetics & Heredity GA PJ381 UT WOS:A1994PJ38100022 PM 7833926 ER PT J AU SCHULTZ, EA CALLEN, DF DOGGETT, NA HAINES, JL LERNER, TJ AF SCHULTZ, EA CALLEN, DF DOGGETT, NA HAINES, JL LERNER, TJ TI MICROSATELLITE REPEAT POLYMORPHISM AT THE D16S366 LOCUS SO HUMAN MOLECULAR GENETICS LA English DT Note ID HUMAN CHROMOSOME-16; PHYSICAL MAP C1 ADELAIDE CHILDRENS HOSP INC,DEPT CYTOGENET & MOLEC GENET,ADELAIDE,SA 5006,AUSTRALIA. LOS ALAMOS NATL LAB,DIV LIFE SCI,LOS ALAMOS,NM 87545. LOS ALAMOS NATL LAB,CTR HUMAN GENOME STUDIES,LOS ALAMOS,NM 87545. HARVARD UNIV,SCH MED,DEPT NEUROL,BOSTON,MA 02115. RP SCHULTZ, EA (reprint author), MASSACHUSETTS GEN HOSP E,MOLEC NEUROGENET UNIT,BOSTON,MA 02129, USA. RI Haines, Jonathan/C-3374-2012; Callen, David/G-1975-2012 FU NINDS NIH HHS [NS24279, NS32099] NR 2 TC 0 Z9 0 U1 0 U2 0 PU OXFORD UNIV PRESS UNITED KINGDOM PI OXFORD PA WALTON ST JOURNALS DEPT, OXFORD, ENGLAND OX2 6DP SN 0964-6906 J9 HUM MOL GENET JI Hum. Mol. Genet. PD SEP PY 1994 VL 3 IS 9 BP 1713 EP 1713 DI 10.1093/hmg/3.9.1713-a PG 1 WC Biochemistry & Molecular Biology; Genetics & Heredity SC Biochemistry & Molecular Biology; Genetics & Heredity GA PJ381 UT WOS:A1994PJ38100044 PM 7833946 ER PT J AU CRAWFIS, R MAX, N BECKER, B AF CRAWFIS, R MAX, N BECKER, B TI VECTOR FIELD VISUALIZATION SO IEEE COMPUTER GRAPHICS AND APPLICATIONS LA English DT Article AB Users can probe vector fields interactively through a construct called flow volumes. They can also examine a global field with a construct called texture splats. RP CRAWFIS, R (reprint author), LAWRENCE LIVERMORE NATL LAB,GRAPH TECHNOL GRP,POB 808,L-301,LIVERMORE,CA 94551, USA. RI Crawfis, Roger/F-9873-2014 OI Crawfis, Roger/0000-0002-5667-2741 NR 16 TC 10 Z9 10 U1 0 U2 0 PU IEEE COMPUTER SOC PI LOS ALAMITOS PA 10662 LOS VAQUEROS CIRCLE, PO BOX 3014, LOS ALAMITOS, CA 90720-1264 SN 0272-1716 J9 IEEE COMPUT GRAPH JI IEEE Comput. Graph. Appl. PD SEP PY 1994 VL 14 IS 5 BP 50 EP 56 DI 10.1109/38.310726 PG 7 WC Computer Science, Software Engineering SC Computer Science GA PD798 UT WOS:A1994PD79800010 ER PT J AU THOMAS, VA LING, KM JONES, ME TOLAND, B LIN, JS ITOH, T AF THOMAS, VA LING, KM JONES, ME TOLAND, B LIN, JS ITOH, T TI FDTD ANALYSIS OF AN ACTIVE ANTENNA SO IEEE MICROWAVE AND GUIDED WAVE LETTERS LA English DT Article AB Coupled FDTD-SPICE simulations are performed for an active antenna problem. The results are comparable to previously published results using FDTD in conjunction with special integration techniques for the nonlinear elements. Some differences occur, and better agreement with experiment is observed for our newer approach. The main advantages are that all of the SPICE device models are directly available for FDTD modeling and the efficient SPICE integration schemes can be used directly. No user intervention is required for either the device models or the integration schemes. RP THOMAS, VA (reprint author), LOS ALAMOS NATL LAB,LOS ALAMOS,NM 87545, USA. NR 0 TC 21 Z9 22 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 1051-8207 J9 IEEE MICROW GUIDED W JI IEEE Microw. Guided Wave Lett. PD SEP PY 1994 VL 4 IS 9 BP 296 EP 298 DI 10.1109/75.311512 PG 3 WC Engineering, Electrical & Electronic SC Engineering GA PE803 UT WOS:A1994PE80300002 ER PT J AU FOSTER, I AF FOSTER, I TI TASK PARALLELISM AND HIGH-PERFORMANCE LANGUAGES SO IEEE PARALLEL & DISTRIBUTED TECHNOLOGY LA English DT Article AB High Performance Fortran currently lacks support for explicit task parallelism. This article explains why task parallelism is important, and describes one candidate task-parallel model: the Fortran M extensions to Fortran 77. RP FOSTER, I (reprint author), ARGONNE NATL LAB,DIV MATH & COMP SCI,9700 S CASS AVE,ARGONNE,IL 60439, USA. NR 10 TC 4 Z9 4 U1 0 U2 0 PU IEEE COMPUTER SOC PI LOS ALAMITOS PA 10662 LOS VAQUEROS CIRCLE, PO BOX 3014, LOS ALAMITOS, CA 90720-1264 SN 1063-6552 J9 IEEE PARALL DISTRIB JI IEEE Parallel Distrib. Technol. PD FAL PY 1994 VL 2 IS 3 BP 27 EP 36 DI 10.1109/M-PDT.1994.329794 PG 10 WC Computer Science, Theory & Methods; Engineering, Electrical & Electronic SC Computer Science; Engineering GA PW320 UT WOS:A1994PW32000009 ER PT J AU LEAR, KL SCHNEIDER, RP CHOQUETTE, KD KILCOYNE, SP FIGIEL, JJ ZOLPER, JC AF LEAR, KL SCHNEIDER, RP CHOQUETTE, KD KILCOYNE, SP FIGIEL, JJ ZOLPER, JC TI VERTICAL-CAVITY SURFACE-EMITTING LASERS WITH 21-PERCENT EFFICIENCY BY METALORGANIC VAPOR-PHASE EPITAXY SO IEEE PHOTONICS TECHNOLOGY LETTERS LA English DT Article ID RESISTANCE; MOCVD AB Proton implanted, vertical cavity top-surface emitting lasers exhibit the highest single-mode and multi-mode output powers, highest power conversion efficiency, and lowest threshold voltage for such devices reported to date. These lasers use new mirror grading designs that are enabled by metalorganic vapor phase epitaxy's capabilities of alloy grading and carbon doping. The results validate this growth technology by exceeding the previous best results which were based on molecular beam epitaxy. RP LEAR, KL (reprint author), SANDIA NATL LABS,ALBUQUERQUE,NM 87185, USA. NR 15 TC 45 Z9 46 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 SEP PY 1994 VL 6 IS 9 BP 1053 EP 1055 DI 10.1109/68.324666 PG 3 WC Engineering, Electrical & Electronic; Optics; Physics, Applied SC Engineering; Optics; Physics GA PK226 UT WOS:A1994PK22600001 ER PT J AU BANTA, L RAWSON, KD AF BANTA, L RAWSON, KD TI SENSOR FUSION FOR MINING ROBOTS SO IEEE TRANSACTIONS ON INDUSTRY APPLICATIONS LA English DT Article ID VISION AB The use of robots for work in hazardous or unpleasant environments is one factor driving the demand for machines of ever-increasing autonomy and intelligence. Such machines are required to sense and interpret situations, plan strategies, and execute tasks with nearly absolute reliability. Negotiation of complex environments requires the use of a variety of different sensor types and the interpretation of conflicting or missing data, diagnosis of faulty sensors, and the ability to reconfigure a system to work with a partially inoperative sensor suite. This paper focuses on the issues of integration of information from disparate sensor types in the presence of noise and uncertainty. The application is a mobile robot called the autonomous navigation testbed being used at West Virginia University for research in mining robot applications. This paper describes both traditional control techniques and neural-network-based methods being used to interpret data from a variety of sensors on the mobile testbed. C1 US DOE,MORGANTOWN ENERGY TECHNOL CTR,MORGANTOWN,WV 26505. RP BANTA, L (reprint author), W VIRGINIA UNIV,DEPT MAE,MORGANTOWN,WV 26506, USA. NR 14 TC 6 Z9 6 U1 0 U2 1 PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017-2394 SN 0093-9994 J9 IEEE T IND APPL JI IEEE Trans. Ind. Appl. PD SEP-OCT PY 1994 VL 30 IS 5 BP 1321 EP 1325 DI 10.1109/28.315246 PG 5 WC Engineering, Multidisciplinary; Engineering, Electrical & Electronic SC Engineering GA PH605 UT WOS:A1994PH60500024 ER PT J AU SMEDLEY, KM SHAFER, RE AF SMEDLEY, KM SHAFER, RE TI EXPERIMENTAL-DETERMINATION OF ELECTRICAL CHARACTERISTICS AND CIRCUIT MODELS OF SUPERCONDUCTING DIPOLE MAGNETS SO IEEE TRANSACTIONS ON MAGNETICS LA English DT Article AB Due to the effects of eddy currents and parasitic capacitance, the electrical characteristics of superconducting magnets are not completely inductive; instead, they are frequency dependent functions. This paper develops a method of accurately measuring the ac characteristics and determining the circuit models of superconducting magnets that characterize the eddy currents and the parasitic capacitance. This measurement method can be used to analyze eddy currents and the resulting circuit model can be used to study the transmission line effect of long magnet strings. C1 LOS ALAMOS NATL LAB,LOS ALAMOS,NM 87545. RP SMEDLEY, KM (reprint author), UNIV CALIF IRVINE,DEPT ELECT & COMP ENGN,IRVINE,CA 92717, USA. NR 2 TC 3 Z9 3 U1 0 U2 0 PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017-2394 SN 0018-9464 J9 IEEE T MAGN JI IEEE Trans. Magn. PD SEP PY 1994 VL 30 IS 5 BP 2708 EP 2712 DI 10.1109/20.312510 PN 1 PG 5 WC Engineering, Electrical & Electronic; Physics, Applied SC Engineering; Physics GA PD541 UT WOS:A1994PD54100002 ER PT J AU LORIMER, WL LIEU, DK HULL, JR MULCAHY, TM ROSSING, TD AF LORIMER, WL LIEU, DK HULL, JR MULCAHY, TM ROSSING, TD TI CORRELATION OF EXPERIMENTAL-DATA AND 3-DIMENSIONAL FINITE-ELEMENT MODELING OF A SPINNING MAGNET ARRAY SO IEEE TRANSACTIONS ON MAGNETICS LA English DT Article; Proceedings Paper CT 9th Conference on the Computation of Electromagnetic Fields (COMPUMAG 93) CY OCT 31-NOV 04, 1993 CL MIAMI, FL SP DIGITAL EQUIPMENT CORP, USA, VECTOR FIELDS INC, UK, INFOLYTICA CORP, CANADA, GE TRANSPORTAT SYST, USA, IBM CORP, USA, ALPS ELECT CO LTD, JAPAN, ANSOFT CORP, USA, BATH UNIV, APPL ELECTROMAGNET CTR, UK, DAEWOO ELECTR CO, KOREA, HYOSUNG IND CO, KOREA, INTEGRATED ENGN SOFTWARE INC, KOREA, MATSUSHITA ELECT IND CO LTD, JAPAN, SAMSUNG ELECTRO MECH, KOREA, SWANSEN ANAL SYST, USA, FLORIDA INT UNIV, USA AB A magnet array was spun above an aluminum disk, and the drag torque was measured for various speeds and pp sizes. Drag torques calculated using a three-dimensional finite element program were consistent with measured values. The finite element model was also used to determine the effects of the polarity and position of magnets in the source array. The peak torque was shown to occur when magnets are located at a radius equal to 70% of the disk radius. A magnet array with alternate magnets reversed was shown to produce more than twice the drag of an array comprised of parallel magnets. An approximation for fields under the magnet centers was obtained using a two-dimensional analytical solution. C1 ARGONNE NATL LAB,ARGONNE,IL 60439. RP LORIMER, WL (reprint author), UNIV CALIF BERKELEY,DEPT MECH ENGN,BERKELEY,CA 94720, USA. NR 3 TC 5 Z9 6 U1 0 U2 0 PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017-2394 SN 0018-9464 J9 IEEE T MAGN JI IEEE Trans. Magn. PD SEP PY 1994 VL 30 IS 5 BP 3004 EP 3007 DI 10.1109/20.312569 PN 2 PG 4 WC Engineering, Electrical & Electronic; Physics, Applied SC Engineering; Physics GA PD542 UT WOS:A1994PD54200037 ER PT J AU VEKLEROV, E AF VEKLEROV, E TI HOW TO COMPUTE THE DIFFERENCE BETWEEN TOMOGRAPHIC-IMAGES SO IEEE TRANSACTIONS ON MEDICAL IMAGING LA English DT Letter AB An algorithm for estimating the difference between two tomographic images is proposed if the two data vectors are obtained in nonoverlapping time intervals. The algorithm takes advantage of statistical independence of the two vectors. The results are significantly different from the traditional approach in which the two images are reconstructed separately and then subtracted. RP VEKLEROV, E (reprint author), LAWRENCE BERKELEY LAB,BERKELEY,CA 94720, USA. NR 7 TC 4 Z9 4 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 0278-0062 J9 IEEE T MED IMAGING JI IEEE Trans. Med. Imaging PD SEP PY 1994 VL 13 IS 3 BP 566 EP 569 DI 10.1109/42.310890 PG 4 WC Computer Science, Interdisciplinary Applications; Engineering, Biomedical; Engineering, Electrical & Electronic; Imaging Science & Photographic Technology; Radiology, Nuclear Medicine & Medical Imaging SC Computer Science; Engineering; Imaging Science & Photographic Technology; Radiology, Nuclear Medicine & Medical Imaging GA PF414 UT WOS:A1994PF41400017 PM 18218533 ER PT J AU ASIF, M PETERSEN, JN KAUFMAN, EN COSGROVE, JM SCOTT, TC AF ASIF, M PETERSEN, JN KAUFMAN, EN COSGROVE, JM SCOTT, TC TI A DYNAMIC-MODEL OF THE HYDRODYNAMICS OF A LIQUID FLUIDIZED-BED SO INDUSTRIAL & ENGINEERING CHEMISTRY RESEARCH LA English DT Article ID SEGREGATION AB The efficient design, operation, and scale up of novel fluidized bed bioreactors for direct coal liquefaction require detailed knowledge of reactor axial pressure drop, dispersion of the solid and liquid phases, and the particle size distribution as a function of axial position. In this paper, a fully predictive mathematical description of the hydrodynamics of a liquid fluidized bed, containing no adjustable parameters, is developed. This model is compared with experimental data obtained from a liquid fluidized bed containing finely divided coal particles. The emphasis of this study is the development of a predictive mathematical model to appropriately describe the transient behavior of such systems subject to changes in the liquid superficial velocity. The underlying mathematical treatment of this problem is based on particle mass transport mechanisms of dispersion and convection. The particle velocity responsible for convection and the particle dispersion coefficients were evaluated using correlations developed previously. The comparison of the model predictions with the experimental data for coal fluidized beds shows excellent agreement. C1 WASHINGTON STATE UNIV,DEPT CHEM ENGN,PULLMAN,WA 99164. OAK RIDGE NATL LAB,CTR BIOPROC RES & DEV,OAK RIDGE,TN 37831. RI Petersen, James/B-8924-2008; Asif, Mohammad/C-6332-2009 OI Asif, Mohammad/0000-0003-3196-0074 NR 14 TC 15 Z9 15 U1 0 U2 4 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 SN 0888-5885 J9 IND ENG CHEM RES JI Ind. Eng. Chem. Res. PD SEP PY 1994 VL 33 IS 9 BP 2151 EP 2156 DI 10.1021/ie00033a018 PG 6 WC Engineering, Chemical SC Engineering GA PF794 UT WOS:A1994PF79400018 ER PT J AU LEVINE, LO AURAND, SS AF LEVINE, LO AURAND, SS TI EVALUATING AUTOMATED WORK-FLOW SYSTEMS FOR ADMINISTRATIVE PROCESSES SO INTERFACES LA English DT Article DE SIMULATION; APPLICATIONS AB Electronic imaging (scanning and digitizing documents for computer storage) is used in ''work-flow automation,'' in which business documents are indexed into an electronic database, electronically routed, and monitored as they proceed through processing. We developed a discrete event simulation model, using the SIMAN computer simulation language, to evaluate the impact of employing work-flow automation to support the processing of travel and expense reports at the Pacific Northwest Laboratory. Our analysis showed that other changes would affect the performance of the process more favorably and that the processing office depended on external systems to achieve better customer service. C1 ARIZONA STATE UNIV, CIM SYST RES CTR, TEMPE, AZ 85287 USA. RP LEVINE, LO (reprint author), PACIFIC NW LAB, BATTELLE BLVD, RICHLAND, WA 99352 USA. NR 7 TC 7 Z9 7 U1 0 U2 2 PU INST OPERATIONS RESEARCH MANAGEMENT SCIENCES PI LINTHICUM HTS PA 901 ELKRIDGE LANDING RD, STE 400, LINTHICUM HTS, MD 21090-2909 SN 0092-2102 J9 INTERFACES JI Interfaces PD SEP-OCT PY 1994 VL 24 IS 5 BP 141 EP 151 DI 10.1287/inte.24.5.141 PG 11 WC Management; Operations Research & Management Science SC Business & Economics; Operations Research & Management Science GA PP057 UT WOS:A1994PP05700017 ER PT J AU CHUNG, I WEITSMAN, Y AF CHUNG, I WEITSMAN, Y TI A MECHANICS MODEL FOR THE COMPRESSIVE RESPONSE OF FIBER-REINFORCED COMPOSITES SO INTERNATIONAL JOURNAL OF SOLIDS AND STRUCTURES LA English DT Article ID CARBON AB This article presents a model for the uni-axial compressive response of uni-directionally reinforced fibrous composite. The model accounts for the non-linear shear response and the failure strain of the matrix, incorporating both aspects into a non-linear field equation which governs the load-deflection process. In addition, the model considers the effects of two kinds of geometric imperfections, namely, initial fiber waviness and random fiber spacing. it is shown that, under uni-axial compression, random fiber spacing may instigate the formation of severe transverse loadings on the fibers, which suggest the existence of a transitional mechanism from micro-buckling to micro-kinking. Computational results are presented which illuminate the effects of several material and geometric factors on the compressive strength of composites. C1 OAK RIDGE NATL LAB,DIV ENGN TECHNOL,OAK RIDGE,TN 37831. RP CHUNG, I (reprint author), UNIV TENNESSEE,DEPT ENGN SCI & MECH,KNOXVILLE,TN 37996, USA. NR 28 TC 16 Z9 17 U1 1 U2 2 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD, ENGLAND OX5 1GB SN 0020-7683 J9 INT J SOLIDS STRUCT JI Int. J. Solids Struct. PD SEP PY 1994 VL 31 IS 18 BP 2519 EP 2536 DI 10.1016/0020-7683(94)90035-3 PG 18 WC Mechanics SC Mechanics GA PG529 UT WOS:A1994PG52900007 ER PT J AU GARRETT, BC SCHENTER, GK AF GARRETT, BC SCHENTER, GK TI VARIATIONAL TRANSITION-STATE THEORY FOR ACTIVATED CHEMICAL-REACTIONS IN SOLUTION SO INTERNATIONAL REVIEWS IN PHYSICAL CHEMISTRY LA English DT Review ID EQUILIBRIUM SOLVATION DYNAMICS; SPATIALLY DEPENDENT FRICTION; ATOM TRANSFER-REACTIONS; FREE-ENERGY SURFACES; RATE CONSTANTS; DISSIPATIVE SYSTEMS; CONDENSED PHASES; POLAR-SOLVENTS; SN2 REACTION; INTRAMOLECULAR STRUCTURES AB An approach is outlined for including solvent effects in variational transition state theory calculations of rate constants for activated chemical reactions in solution. The focus is on methods capable of first-principles predictions of reaction rate constants from interatomic potential energy surfaces. The approach separates the system into a cluster model that is treated explicitly and the 'solvent' that is treated approximately, and includes both equilibrium solvation effects on interaction energies and non-equilibrium effects that enter through a solvent friction model. We discuss methods used to included quantum-mechanical effects on bound vibrational motions and quantum-mechanical effects on motion along a reaction coordinate (e.g. quantum tunnelling). RP GARRETT, BC (reprint author), PACIFIC NW LAB, MOLEC SCI RES CTR, RICHLAND, WA 99352 USA. RI Garrett, Bruce/F-8516-2011; Schenter, Gregory/I-7655-2014 OI Schenter, Gregory/0000-0001-5444-5484 NR 145 TC 28 Z9 28 U1 2 U2 7 PU TAYLOR & FRANCIS LTD PI ABINGDON PA 4 PARK SQUARE, MILTON PARK, ABINGDON OX14 4RN, OXON, ENGLAND SN 0144-235X J9 INT REV PHYS CHEM JI Int. Rev. Phys. Chem. PD SEP PY 1994 VL 13 IS 2 BP 263 EP 289 DI 10.1080/01442359409353296 PG 27 WC Chemistry, Physical; Physics, Atomic, Molecular & Chemical SC Chemistry; Physics GA PF426 UT WOS:A1994PF42600004 ER PT J AU DEGRASSE, RW AF DEGRASSE, RW TI PROTECTING PLUTONIUM SO ISSUES IN SCIENCE AND TECHNOLOGY LA English DT Letter RP DEGRASSE, RW (reprint author), US DOE,SURPLUS FISSILE MAT CONTROL & DISPOSIT PROJECT,WASHINGTON,DC 20545, USA. NR 1 TC 0 Z9 0 U1 0 U2 0 PU NATL ACAD SCIENCES PI WASHINGTON PA 2101 CONSTITUTION AVE NW, WASHINGTON, DC 20418 SN 0748-5492 J9 ISSUES SCI TECHNOL JI Issues Sci. Technol. PD FAL PY 1994 VL 11 IS 1 BP 10 EP 10 PG 1 WC Engineering, Multidisciplinary; Engineering, Industrial; Multidisciplinary Sciences; Social Issues SC Engineering; Science & Technology - Other Topics; Social Issues GA PL710 UT WOS:A1994PL71000008 ER PT J AU INDUSI, JP AF INDUSI, JP TI PROTECTING PLUTONIUM SO ISSUES IN SCIENCE AND TECHNOLOGY LA English DT Letter RP INDUSI, JP (reprint author), BROOKHAVEN NATL LAB,DEPT ADV TECHNOL,UPTON,NY 11973, USA. NR 1 TC 0 Z9 0 U1 0 U2 0 PU NATL ACAD SCIENCES PI WASHINGTON PA 2101 CONSTITUTION AVE NW, WASHINGTON, DC 20418 SN 0748-5492 J9 ISSUES SCI TECHNOL JI Issues Sci. Technol. PD FAL PY 1994 VL 11 IS 1 BP 12 EP 12 PG 1 WC Engineering, Multidisciplinary; Engineering, Industrial; Multidisciplinary Sciences; Social Issues SC Engineering; Science & Technology - Other Topics; Social Issues GA PL710 UT WOS:A1994PL71000010 ER PT J AU JANKOWSKI, AF SEDILLO, EM HAYES, JP AF JANKOWSKI, AF SEDILLO, EM HAYES, JP TI ELASTIC PROPERTY DEPENDENCE ON LAYER PERIODICITY IN CU/NI SUPERLATTICES SO JAPANESE JOURNAL OF APPLIED PHYSICS PART 1-REGULAR PAPERS SHORT NOTES & REVIEW PAPERS LA English DT Article DE CU/NI; ELASTIC PROPERTIES; SPUTTER DEPOSITION; TENSILE TESTING; THIN FILMS ID SOLID-SOLUTIONS; GOLD-NICKEL; FOILS; MULTILAYERS; MODULUS; FILMS; PALLADIUM; CU/PD AB Cu/Ni superlattices are prepared by magnetron sputter deposition and structurally characterized with X-ray diffraction measurement. A 1.2-4.5 nm range of layer pair spacings is produced in a series of 1-2-mu m-thick films which have a [111] textured growth. Uniaxial tensile testing is used to produce load-displacement curves from free-standing Cu/Ni films and calibration standards of Cu and Ni films. Direct measurement of the yield and ultimate stresses as well as Young's modulus is performed for the Cu/Ni films. The measured Young's modulus shows a bimodal variation with layer pair spacing. A maximum increase of 50% in Young's modulus, above the rule-of-mixtures value, is measured for a 2-nm-thick layer pair sample. The yield stress behavior follows the modulus trend with layer pair spacing, whereas the ultimate stress inversely follows the trend, that is, the stiff est samples are the most brittle. Isothermal annealing of the 2-nm-thick Cu/Ni sample progressively homogenizes the layered structure and diminishes the modulus enhancement to the rule-of-mixtures value. RP JANKOWSKI, AF (reprint author), LAWRENCE LIVERMORE NATL LAB,DEPT CHEM & MAT SCI,POB 808,LIVERMORE,CA 94550, USA. NR 22 TC 5 Z9 5 U1 0 U2 0 PU JAPAN J APPLIED PHYSICS PI MINATO-KU TOKYO PA DAINI TOYOKAIJI BLDG 24-8 SHINBASHI 4-CHOME, MINATO-KU TOKYO 105, JAPAN SN 0021-4922 J9 JPN J APPL PHYS 1 JI Jpn. J. Appl. Phys. Part 1 - Regul. Pap. Short Notes Rev. Pap. PD SEP PY 1994 VL 33 IS 9A BP 5019 EP 5025 DI 10.1143/JJAP.33.5019 PG 7 WC Physics, Applied SC Physics GA PM615 UT WOS:A1994PM61500042 ER PT J AU CHRISTENSEN, FE ABDALI, S FREDERIKSEN, PK HORNSTRUP, A RASMUSSEN, I WESTERGAARD, NJ SCHNOPPER, HW LOUIS, E VOORMA, HJ KOSTER, N WIEBICKE, H HALM, I GEPPERT, U SILVER, E LEGROS, M BOROZDIN, K JOENSEN, KD GORENSTEIN, P WOOD, J GUTMAN, G AF CHRISTENSEN, FE ABDALI, S FREDERIKSEN, PK HORNSTRUP, A RASMUSSEN, I WESTERGAARD, NJ SCHNOPPER, HW LOUIS, E VOORMA, HJ KOSTER, N WIEBICKE, H HALM, I GEPPERT, U SILVER, E LEGROS, M BOROZDIN, K JOENSEN, KD GORENSTEIN, P WOOD, J GUTMAN, G TI SOME APPLICATIONS OF NANOMETER-SCALE STRUCTURES FOR CURRENT AND FUTURE X-RAY SPACE RESEARCH SO JOURNAL DE PHYSIQUE III LA English DT Article ID GRATING SPECTROMETER; SPECTRA; MIRRORS AB Nanometer scale structures such as multilayers, gratings and natural crystals are playing an increasing role in spectroscopic applications for X-ray astrophysics. A few examples are briefly described as an introduction to current and planned applications pursued at the Danish Space Research Institute in collaboration with the FOM Institute for Plasma Physics, Nieuwegein, the Max-Planck-Institut fur Extraterrestrische Physik, Aussenstelle Berlin, the Space Research Institute, Russian Academy of Sciences, the Smithsonian Astrophysical Observatory, Ovonics Synthetic Materials Company and Lawrence Livermore National Laboratory. These examples include: 1. the application of multilayered Si crystals for simultaneous spectroscopy in two energy bands one centred around the SK-emission near 2.45 keV and the other below the CK absorption edge at 0.284 keV ; 2. the use of in-depth graded period multilayer structures for broad band spectroscopy in the energy range up to 100 keV; 3. the potential use of large perfect asymmetrically cut Si or Ge crystals combined with a short focal length multilayer telescope for ultra high energy resolution solar/stellar spectroscopy with E/DELTAE > 10(4) and; 4. high throughput multilayer coated telescope for high resolution Fe K line spectroscopy with microcalorimeters. C1 FOM,INST PLASMA PHYS,3430 BE NIEUWEGEIN,NETHERLANDS. MAX PLANCK INST EXTRATERR PHYS,D-12489 BERLIN,GERMANY. LAWRENCE LIVERMORE NATL LAB,EXPTL ASTROPHYS LAB,LIVERMORE,CA 94550. RUSSIAN ACAD SCI,SPACE RES INST,DEPT HIGH ENERGY ASTROPHYS,MOSCOW 117810,RUSSIA. OVON SYNTHET MAT CO,TROY,MI 48084. HARVARD SMITHSONIAN CTR ASTROPHYS,CAMBRIDGE,MA 02138. RP CHRISTENSEN, FE (reprint author), DANISH SPACE RES INST,G LUNDTOFTEVEJ 7,DK-2800 LYNGBY,DENMARK. NR 46 TC 1 Z9 1 U1 0 U2 1 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 1155-4320 J9 J PHYS III JI J. Phys. III PD SEP PY 1994 VL 4 IS 9 BP 1599 EP 1612 DI 10.1051/jp3:1994227 PG 14 WC Materials Science, Multidisciplinary; Physics, Applied; Physics, Fluids & Plasmas SC Materials Science; Physics GA PH373 UT WOS:A1994PH37300012 ER PT J AU STEINBERG, DJ AF STEINBERG, DJ TI COMPUTER STUDIES OF THE DYNAMIC STRENGTH OF CERAMICS .2. SO JOURNAL DE PHYSIQUE IV LA English DT Article; Proceedings Paper CT International Conference on Mechanical and Physical Behaviour of Materials under Dynamic Loading (EURODYMAT 94) CY SEP 26-30, 1994 CL OXFORD, ENGLAND ID TEMPERATURE; PRESSURE; ZIRCONIA AB Our previous constitutive model for fully dense ceramics has been extended to include Al2O3 (AD999) and Si3N4; there are now parameters for seven materials. New experimental data, such as spall and double-shock wave-profiles for SiC and B4C, have been successfully simulated. Additional experiments are proposed which should help elucidate the remaining problems. RP STEINBERG, DJ (reprint author), LAWRENCE LIVERMORE NATL LAB,POB 808 L35,LIVERMORE,CA 94551, USA. NR 22 TC 2 Z9 2 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 1155-4339 J9 J PHYS IV JI J. Phys. IV PD SEP PY 1994 VL 4 IS C8 BP 183 EP 188 DI 10.1051/jp4:1994826 PG 6 WC Physics, Multidisciplinary SC Physics GA PZ056 UT WOS:A1994PZ05600027 ER PT J AU LASSILA, DH LEBLANC, MM MAGNESS, FH AF LASSILA, DH LEBLANC, MM MAGNESS, FH TI THE EFFECT OF GRAIN-SIZE ON DEFORMATION AND FAILURE OF COPPER UNDER DYNAMIC LOADING SO JOURNAL DE PHYSIQUE IV LA English DT Article; Proceedings Paper CT International Conference on Mechanical and Physical Behaviour of Materials under Dynamic Loading (EURODYMAT 94) CY SEP 26-30, 1994 CL OXFORD, ENGLAND ID FLOW-STRESS; STRAIN; NECKING AB In this work, we show experimentally, and using computer modeling that the effect of grain size manifested as an effect on constitutive behavior can have an appreciable effect on the deformation stability of copper deformed in tension under both quasi-static and dynamic loading: an increase in grain size results in greater extents of deformation. In a work previously published by Gourdin and Lassila, the effect of grain size was incorporated into the Mechanical Threshold Stress (MTS) material model applied to OFE copper. Dynamic tensile tests were modeled using a 3-D computer code in which the MTS material model was incorporated. The computer code model accurately predicted the occurrence and growth of necking during dynamic deformation as a function of grain size. RP LASSILA, DH (reprint author), LAWRENCE LIVERMORE NATL LAB,L-342,POB 808,LIVERMORE,CA 94551, USA. NR 16 TC 0 Z9 0 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 1155-4339 J9 J PHYS IV JI J. Phys. IV PD SEP PY 1994 VL 4 IS C8 BP 195 EP 199 DI 10.1051/jp4:1994828 PG 5 WC Physics, Multidisciplinary SC Physics GA PZ056 UT WOS:A1994PZ05600029 ER PT J AU GOURDIN, WH LASSILA, DH LEBLANC, MM SHIELDS, AL AF GOURDIN, WH LASSILA, DH LEBLANC, MM SHIELDS, AL TI THE INFLUENCE OF TUNGSTEN ALLOYING ON THE MECHANICAL-PROPERTIES OF TANTALUM SO JOURNAL DE PHYSIQUE IV LA English DT Article; Proceedings Paper CT International Conference on Mechanical and Physical Behaviour of Materials under Dynamic Loading (EURODYMAT 94) CY SEP 26-30, 1994 CL OXFORD, ENGLAND ID THRESHOLD STRESS; FLOW-STRESS; STRAIN RATE; TEMPERATURE; DEFORMATION; COPPER AB In mechanical tests of tantalum-tungsten alloys with nominal tungsten contents between 0 and 10 wt% for strain rates between 0.000016 and 6800 s(-1) and temperatures between 77 and 400 K, the addition of tungsten noticeably reduces the strain-rate dependence of the now stress of tantalum near yield. It also subtly alters the strain-rate behavior of the work hardening, making it more like that of copper, an fee metal. These effects are reflected in the limiting strains for uniform plastic deformation calculated from our flow curves. For unalloyed tantalum, the instability strain appears to drop dramatically for strain rates in excess of approximately 0.005 s(-1) whereas for tungsten bearing alloys, it remains unchanged or increases slightly. Tungsten alloys may therefore be preferable to unalloyed tantalum in applications that demand substantial ductility at high rates of strain. We briefly discuss possible mechanisms for plastic flow in tantalum and how they might be affected by tungsten additions to produce the effects we observe. RP GOURDIN, WH (reprint author), LAWRENCE LIVERMORE NATL LAB,POB 808,LIVERMORE,CA 94551, USA. NR 14 TC 5 Z9 5 U1 0 U2 3 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 1155-4339 J9 J PHYS IV JI J. Phys. IV PD SEP PY 1994 VL 4 IS C8 BP 207 EP 212 PG 6 WC Physics, Multidisciplinary SC Physics GA PZ056 UT WOS:A1994PZ05600031 ER PT J AU VECCHIO, KS GRAY, GT AF VECCHIO, KS GRAY, GT TI SHOCK-LOADING RESPONSE OF 6061-T6 ALUMINUM ALUMINA METAL-MATRIX COMPOSITES SO JOURNAL DE PHYSIQUE IV LA English DT Article; Proceedings Paper CT International Conference on Mechanical and Physical Behaviour of Materials under Dynamic Loading (EURODYMAT 94) CY SEP 26-30, 1994 CL OXFORD, ENGLAND AB The purpose of this research is to systematically study the influence of peak-shock pressure and second-phase reinforcement on the structure/property response of shock-loaded 6061-T6 Al-alumina composites. The reload stress-strain response of monolithic 6061-T6 Al showed no increased shock hardening compared to the unshocked material deformed to an equivalent strain. The reload stress-strain response of the shock-loaded 6061-T6 Al-alumina composites exhibits a lower reload yield strength than the flow stress of the starting composites. Wavespeed measurements of shock-prestrained specimens showed no degradation compared to un-shocked specimens, and reload stress-strain response of the shock-prestrained composites, after resolutionizing and T6 aging, showed that the composites recovered their full as-received stress-strain responses. C1 LOS ALAMOS NATL LAB,LOS ALAMOS,NM 87545. RP VECCHIO, KS (reprint author), UNIV CALIF SAN DIEGO,DEPT APPL MECH & ENGN SCI,LA JOLLA,CA 92093, USA. NR 6 TC 6 Z9 6 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 1155-4339 J9 J PHYS IV JI J. Phys. IV PD SEP PY 1994 VL 4 IS C8 BP 231 EP 236 DI 10.1051/jp4:1994834 PG 6 WC Physics, Multidisciplinary SC Physics GA PZ056 UT WOS:A1994PZ05600035 ER PT J AU KIPP, ME GRADY, DE AF KIPP, ME GRADY, DE TI SHOCK PHASE-TRANSFORMATION AND RELEASE PROPERTIES OF ALUMINUM NITRIDE SO JOURNAL DE PHYSIQUE IV LA English DT Article; Proceedings Paper CT International Conference on Mechanical and Physical Behaviour of Materials under Dynamic Loading (EURODYMAT 94) CY SEP 26-30, 1994 CL OXFORD, ENGLAND AB Aluminum nitride is characterized by a non-recoverable volume phase transformation from the wurtzite (hexagonal) to the rocksalt (cubic) structure that commences about 22 GPa, accompanied by a volume strain of about 20%. A study of the manifestation of this large volume change under shock loading was made with four uniaxial strain impact experiments. Particle velocity histories of the shock and release states were obtained corresponding to impact pressures of 40 GPa, including the evolution of the shock and release waves with propagation distance. Stress - strain features characterizing aluminum nitride, including the phase transformation, were determined with numerical analysis techniques. RP KIPP, ME (reprint author), SANDIA NATL LABS,ALBUQUERQUE,NM 87185, USA. NR 14 TC 20 Z9 20 U1 1 U2 2 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 1155-4339 J9 J PHYS IV JI J. Phys. IV PD SEP PY 1994 VL 4 IS C8 BP 249 EP 256 DI 10.1051/jp4:1994837 PG 8 WC Physics, Multidisciplinary SC Physics GA PZ056 UT WOS:A1994PZ05600038 ER PT J AU JOHNSON, JN HIXSON, RS GRAY, GT AF JOHNSON, JN HIXSON, RS GRAY, GT TI IMPACT LOADING OF AN ALUMINUM ALUMINA COMPOSITE SO JOURNAL DE PHYSIQUE IV LA English DT Article; Proceedings Paper CT International Conference on Mechanical and Physical Behaviour of Materials under Dynamic Loading (EURODYMAT 94) CY SEP 26-30, 1994 CL OXFORD, ENGLAND AB The combined demands of increased strength and reduced weight in modem dynamic structural applications require improved understanding of composite materials subject to impact conditions. In order to isolate and identify individual contributions to composite material behavior under these conditions, an experimental and theoretical program was undertaken to examine dynamic behavior of an aluminum/alumina composite consisting of a 6061-T6 aluminum matrix containing elastic, spherical Al2O3 inclusions (10 percent by volume, average diameter similar to 25 microns). Parallel impact experiments are conducted on these composites and on pure 6061-T6 aluminum samples. This combination provides a direct and immediate qualitative picture of the effect of Al2O3 inclusions on the dynamic response of the composite in compression, release, and spallation. Additional experimental information is provided by postshock reload tests of shock-recovered samples at quasi-static and intermediate strain rates. RP JOHNSON, JN (reprint author), LOS ALAMOS NATL LAB,LOS ALAMOS,NM 87545, USA. NR 11 TC 2 Z9 2 U1 0 U2 1 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 1155-4339 J9 J PHYS IV JI J. Phys. IV PD SEP PY 1994 VL 4 IS C8 BP 325 EP 330 DI 10.1051/jp4:1994849 PG 6 WC Physics, Multidisciplinary SC Physics GA PZ056 UT WOS:A1994PZ05600050 ER PT J AU LASSILA, DH GRAY, GT AF LASSILA, DH GRAY, GT TI DUCTILE-BRITTLE TRANSITION BEHAVIOR OF TUNGSTEN UNDER SHOCK LOADING SO JOURNAL DE PHYSIQUE IV LA English DT Article; Proceedings Paper CT International Conference on Mechanical and Physical Behaviour of Materials under Dynamic Loading (EURODYMAT 94) CY SEP 26-30, 1994 CL OXFORD, ENGLAND AB The ductile-brittle transition behavior of warm-forged tungsten under shock loading conditions was examined by performing shock/soft-recovery experiments at 22 degrees C and 400 degrees C. The results of a recovery experiment at 22 degrees C indicate that shock (19 GPa)-induced strains were accommodated by fracture processes, i.e. there were no indications of shock-induced plastic deformation, and the test sample was reduced to rubble. At 400 degrees C the test sample was recovered intact and the shock-induced plasticity caused deformation banding and an increase in the dislocation density of the material. The results of these experiments demonstrate the principle of a ductile-brittle transition behavior of tungsten under uniaxial shock loading conditions and indicate that explosively-driven deformation of the material studied will likely result in pulverization due to shock loading. C1 LOS ALAMOS NATL LAB,LOS ALAMOS,NM 87545. RP LASSILA, DH (reprint author), LAWRENCE LIVERMORE NATL LAB,L-342,POB 808,LIVERMORE,CA 94550, USA. NR 13 TC 7 Z9 7 U1 0 U2 5 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 1155-4339 J9 J PHYS IV JI J. Phys. IV PD SEP PY 1994 VL 4 IS C8 BP 349 EP 354 DI 10.1051/jp4:1994853 PG 6 WC Physics, Multidisciplinary SC Physics GA PZ056 UT WOS:A1994PZ05600054 ER PT J AU GRAY, GT AF GRAY, GT TI INFLUENCE OF SHOCK LOADING ON THE STRUCTURE-PROPERTY RESPONSE OF TI-48AL-2CR-2NB AND TI-24AL-11NB SO JOURNAL DE PHYSIQUE IV LA English DT Article; Proceedings Paper CT International Conference on Mechanical and Physical Behaviour of Materials under Dynamic Loading (EURODYMAT 94) CY SEP 26-30, 1994 CL OXFORD, ENGLAND ID DEFORMATION AB Intermetallics are receiving increasing attention for applications requiring high-leverage materials possessing potentially high pay-offs such as in gas-turbine engines. While the quasistatic deformation response of a broad range of intermetallics is receiving intense scientific and engineering study increased utilization of intermetallics under dynamic loading requires an understanding of their high-rate / shock-wave behavior. In this paper the influence of shock loading on the structure / property behavior of Ti-48Al-2Cr-2Nb and Ti-24Al-11Nb is presented. The reload constitutive response of both shock-loaded intermetallics supports the dynamic deformation of both intermetallics being controlled by a Peierls mechanism. Defect generation and storage in intermetallics is compared and contrasted to that typical to conventional disordered metals and alloys. RP GRAY, GT (reprint author), LOS ALAMOS NATL LAB,LOS ALAMOS,NM 87545, USA. NR 14 TC 7 Z9 7 U1 0 U2 2 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 1155-4339 J9 J PHYS IV JI J. Phys. IV PD SEP PY 1994 VL 4 IS C8 BP 373 EP 378 DI 10.1051/jp4:1994857 PG 6 WC Physics, Multidisciplinary SC Physics GA PZ056 UT WOS:A1994PZ05600058 ER PT J AU GRADY, DE AF GRADY, DE TI SHOCK-WAVE STRENGTH PROPERTIES OF BORON-CARBIDE AND SILICON-CARBIDE SO JOURNAL DE PHYSIQUE IV LA English DT Article; Proceedings Paper CT International Conference on Mechanical and Physical Behaviour of Materials under Dynamic Loading (EURODYMAT 94) CY SEP 26-30, 1994 CL OXFORD, ENGLAND AB Time-resolved velocity interferometry measurements have been made on baron carbide and silicon carbide ceramics to assess dynamic equation-of-state and strength properties of these materials. Hugoniot precursor characteristics, and post-yield shack and release wave properties, indicated markedly different dynamic strength and flow behavior for the two carbides. RP GRADY, DE (reprint author), SANDIA NATL LABS,DEPT IMPACT PHYS,ALBUQUERQUE,NM 87185, USA. NR 12 TC 33 Z9 33 U1 3 U2 16 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 1155-4339 J9 J PHYS IV JI J. Phys. IV PD SEP PY 1994 VL 4 IS C8 BP 385 EP 391 PG 7 WC Physics, Multidisciplinary SC Physics GA PZ056 UT WOS:A1994PZ05600060 ER PT J AU DICK, JJ RITCHIE, JP AF DICK, JJ RITCHIE, JP TI THE CRYSTAL ORIENTATION DEPENDENCE OF THE ELASTIC PRECURSOR SHOCK STRENGTH IN THE PETN MOLECULAR EXPLOSIVE AND THE MODELING OF THE STERIC HINDRANCE TO SHEAR BY MOLECULAR MECHANICS SO JOURNAL DE PHYSIQUE IV LA English DT Article; Proceedings Paper CT International Conference on Mechanical and Physical Behaviour of Materials under Dynamic Loading (EURODYMAT 94) CY SEP 26-30, 1994 CL OXFORD, ENGLAND ID PENTAERYTHRITOL TETRANITRATE; INITIATION AB The elastic precursor shock strengths of pentaerythritol tetranitrate (PETN) explosive crystals were measured for [100], [101], [110], and [001] orientations using VISAR instrumentation for samples 3 to 6 mm thick. Input shock strength was 1.14 GPa. Measured precursor amplitudes were 0.38, 0.58, 0.98, and 1.22 GPa, respectively, for the four orientations. Molecular mechanics modeling of slip in the ambient crystal was performed, analagous to the shock-induced shear for different orientations. The results show the observed dependence of the precursor amplitude on crystal orientation for the cases considered and explains why the {110} <1(1) over bar1$> slip system is observed in quasistatic deformation in spite of having the longest Burgers vector. The results confirm the importance of steric hindrance to shear in controlling the orientation-dependent strength in some molecular crystals. RP DICK, JJ (reprint author), LOS ALAMOS NATL LAB,GRP M7,MAIL STOP P952,LOS ALAMOS,NM 87545, USA. NR 19 TC 3 Z9 3 U1 1 U2 2 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 1155-4339 J9 J PHYS IV JI J. Phys. IV PD SEP PY 1994 VL 4 IS C8 BP 393 EP 398 DI 10.1051/jp4:1994860 PG 6 WC Physics, Multidisciplinary SC Physics GA PZ056 UT WOS:A1994PZ05600061 ER PT J AU MURPHY, MJ AF MURPHY, MJ TI CONSTITUTIVE MODEL PARAMETER DETERMINATION FROM GENERIC EFP WARHEAD TESTS SO JOURNAL DE PHYSIQUE IV LA English DT Article; Proceedings Paper CT International Conference on Mechanical and Physical Behaviour of Materials under Dynamic Loading (EURODYMAT 94) CY SEP 26-30, 1994 CL OXFORD, ENGLAND AB The determination of liner material constitutive modeling parameters based on the results of four EFP tests, with different liner geometry's, is described in this paper. This paper presents an approach for determining an ''appropriate set'' of material parameters to describe the deviatoric behavior of the liner material. The Johnson-Cook and Steinberg-Guinan constitutive models are evaluated with the Steinberg model shown to be more suitable because of its upper limit on the flow stress. A set of flow stress hardening parameters are found that provide excellent correlation to the four different EFP warhead design configurations. RP MURPHY, MJ (reprint author), LAWRENCE LIVERMORE NATL LAB,CTR ENERGET MAT,POB 808,L-282,LIVERMORE,CA 94550, USA. NR 9 TC 3 Z9 3 U1 1 U2 1 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 1155-4339 J9 J PHYS IV JI J. Phys. IV PD SEP PY 1994 VL 4 IS C8 BP 483 EP 488 DI 10.1051/jp4:1994875 PG 6 WC Physics, Multidisciplinary SC Physics GA PZ056 UT WOS:A1994PZ05600076 ER PT J AU TONKS, DL AF TONKS, DL TI PERCOLATION WAVE-PROPAGATION, AND VOID LINK-UP EFFECTS IN DUCTILE FRACTURE SO JOURNAL DE PHYSIQUE IV LA English DT Article; Proceedings Paper CT International Conference on Mechanical and Physical Behaviour of Materials under Dynamic Loading (EURODYMAT 94) CY SEP 26-30, 1994 CL OXFORD, ENGLAND ID SIMULATION; SOLIDS; MODEL AB This work investigates the time evolution and spatial morphology of ductile damage based on void growth and coalescence The size enhancement of damage cluster growth, as well as wave speed limiting of growth, are treated microscopically. Simplified 2D plane strain simulations using individual voids are done with uniaxial strain and explained with a probabilistic theory. At low strain rates, fracture occurs by long, localized cracks. At high strain rates, widespread, random damage breaks the system. RP TONKS, DL (reprint author), LOS ALAMOS NATL LAB,DIV APPL THEORET,LOS ALAMOS,NM 87545, USA. NR 15 TC 16 Z9 17 U1 0 U2 2 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 1155-4339 J9 J PHYS IV JI J. Phys. IV PD SEP PY 1994 VL 4 IS C8 BP 665 EP 670 DI 10.1051/jp4:19948101 PG 6 WC Physics, Multidisciplinary SC Physics GA PZ056 UT WOS:A1994PZ05600102 ER PT J AU KAPPESSER, B WIPF, H BARNES, RG BEAUDRY, BJ AF KAPPESSER, B WIPF, H BARNES, RG BEAUDRY, BJ TI THE INFLUENCE OF HYDROGEN AND DISLOCATIONS ON THE INTERNAL-FRICTION IN YTTRIUM SO JOURNAL OF ALLOYS AND COMPOUNDS LA English DT Article ID RELAXATION AB The internal friction spectra of (i) plastically deformed Y, (ii) undeformed H-doped YH0.1 and (iii) plastically deformed and H-doped YH0.1 samples were measured with the help of the vibrating reed technique (polycrystalline foils, 5 K less than or equal to T less than or equal to 320 K, frequencies f between 100 and 1300 Hz, plastic deformations between 5% and 25% due to rolling at room temperature). The deformed (undoped) Y samples exhibit an internal friction peak in the same temperature range as the undeformed doped YH0.1 samples. We found further that combined plastic deformation and H-doping leads to a stronger peak than does sole deformation or H doping. The possible mechanisms for the observed relaxation process are discussed. C1 IOWA STATE UNIV SCI & TECHNOL, AMES LAB, AMES, IA 50011 USA. RP KAPPESSER, B (reprint author), TH DARMSTADT, INST FESTKORPERPHYS, W-6100 DARMSTADT, GERMANY. NR 8 TC 5 Z9 5 U1 0 U2 0 PU ELSEVIER SCIENCE SA PI LAUSANNE PA PO BOX 564, 1001 LAUSANNE, SWITZERLAND SN 0925-8388 EI 1873-4669 J9 J ALLOY COMPD JI J. Alloy. Compd. PD SEP PY 1994 VL 211 BP 249 EP 252 DI 10.1016/0925-8388(94)90494-4 PG 4 WC Chemistry, Physical; Materials Science, Multidisciplinary; Metallurgy & Metallurgical Engineering SC Chemistry; Materials Science; Metallurgy & Metallurgical Engineering GA PK471 UT WOS:A1994PK47100061 ER PT J AU HOLLENBACH, M GROHS, J MAMICH, S KROFT, M DENOYER, ER AF HOLLENBACH, M GROHS, J MAMICH, S KROFT, M DENOYER, ER TI DETERMINATION OF TC-99, TH-230 AND U-234 IN SOILS BY INDUCTIVELY-COUPLED PLASMA-MASS SPECTROMETRY USING FLOW-INJECTION PRECONCENTRATION SO JOURNAL OF ANALYTICAL ATOMIC SPECTROMETRY LA English DT Article; Proceedings Paper CT 1994 Winter Conference on Plasma Spectrochemistry CY JAN 10-15, 1994 CL SAN DIEGO, CA DE TC-99, TH-230 AND U-234 DETERMINATION; INDUCTIVELY COUPLED PLASMA MASS SPECTROMETRY; FLOW INJECTION ID SAMPLES AB A new method is described for the determination of Tc-99, Th-230, and U-234 at ultra-trace levels in soils. The method used flow injection (Fl) for on-line preconcentration of Tc-99, Th-230 and U-234 prior to detection using inductively coupled plasma mass spectrometry (ICP-MS). The Fl-ICP-MS method results in greater sensitivity and freedom from interferences compared with direct aspiration into an ICP mass spectrometer. Detection limits are improved by approximately a factor of 10. The FI-ICP-MS method is also faster, less labour intensive and generates less laboratory waste than traditional radiochemical methods. The accuracy of the method was tested for Tc-99 by comparison to liquid scintillation counting and for Th-230 and U-234 by analysis of a US Department of Energy reference soil. Detection limits in the soil for Tc-99, Th-230 and U-234 were 11 mBq g-1 (0.02 ng g-1), 3.7 mBq g-1 (0.005 ng g-1) and 0.74 mBq g-1 (0.003 ng g-1), respectively. Sample preparation, analysis protocol, and method validation are described. C1 PERKIN ELMER CORP,NORWALK,CT 06859. RP HOLLENBACH, M (reprint author), US DOE,RUST GEOTECH INC,GRAND JUNCT PROJECTS OFF,POB 14000,GRAND JCT,CO 81502, USA. NR 10 TC 51 Z9 51 U1 0 U2 0 PU ROYAL SOC CHEMISTRY PI CAMBRIDGE PA THOMAS GRAHAM HOUSE, SCIENCE PARK MILTON ROAD, CAMBRIDGE, CAMBS, ENGLAND CB4 4WF SN 0267-9477 J9 J ANAL ATOM SPECTROM JI J. Anal. At. Spectrom. PD SEP PY 1994 VL 9 IS 9 BP 927 EP 933 DI 10.1039/ja9940900927 PG 7 WC Chemistry, Analytical; Spectroscopy SC Chemistry; Spectroscopy GA PH792 UT WOS:A1994PH79200006 ER PT J AU KOPPENAAL, DW BARINAGA, CJ SMITH, MR AF KOPPENAAL, DW BARINAGA, CJ SMITH, MR TI PERFORMANCE OF AN INDUCTIVELY-COUPLED PLASMA SOURCE ION-TRAP MASS-SPECTROMETER SO JOURNAL OF ANALYTICAL ATOMIC SPECTROMETRY LA English DT Article; Proceedings Paper CT 1994 Winter Conference on Plasma Spectrochemistry CY JAN 10-15, 1994 CL SAN DIEGO, CA DE INDUCTIVELY COUPLED PLASMA MASS SPECTROMETRY; ION TRAP MASS SPECTROMETRY; POLYATOMIC ION DESTRUCTION; AR+ NEUTRALIZATION ID ISOTOPE RATIO MEASUREMENT; ELECTROSPRAY IONIZATION; RESOLUTION; LEAD; SAMPLES AB A unique system incorporating features of inductively coupled plasma (ICP) and ion trap mass spectrometry (ITMS) is described. The combined ICP-ITMS system is characterized instrumentally and the initial performance features are presented. Bare atomic ions are observed for all elements, including previously problematic high oxygen bond strength elements that produced high levels of MO(n)+ and M(OH)(n)+ ions in early ICP-ITMS experiments. Approximate, unoptimized detection limits of 10-500 pg ml-1 are reported. Other advantages of the system include the complete destruction of typical ICP-MS polyatomic ions and the near complete neutralization of plasma Ar+, both of which contribute to much simpler spectra below 80 m/z. RP KOPPENAAL, DW (reprint author), PACIFIC NW LAB, MS P8-08,POB 999, RICHLAND, WA 99352 USA. NR 38 TC 72 Z9 72 U1 0 U2 7 PU ROYAL SOC CHEMISTRY PI CAMBRIDGE PA THOMAS GRAHAM HOUSE, SCIENCE PARK MILTON ROAD, CAMBRIDGE, CAMBS, ENGLAND CB4 4WF SN 0267-9477 J9 J ANAL ATOM SPECTROM JI J. Anal. At. Spectrom. PD SEP PY 1994 VL 9 IS 9 BP 1053 EP 1058 DI 10.1039/ja9940901053 PG 6 WC Chemistry, Analytical; Spectroscopy SC Chemistry; Spectroscopy GA PH792 UT WOS:A1994PH79200026 ER PT J AU SALASMORALES, JC EVANS, JW AF SALASMORALES, JC EVANS, JW TI FURTHER-STUDIES OF A ZINC AIR CELL EMPLOYING A PACKED-BED ANODE .3. IMPROVEMENTS IN CELL DESIGN SO JOURNAL OF APPLIED ELECTROCHEMISTRY LA English DT Article ID ELECTROLYTE; BATTERY AB A laboratory-scale zinc-air cell described previously has been redesigned with the intention of improving its performance. The zinc was present as a packed bed of 600 mum particles and in this concept the electrolyte and particles are replaced with fresh ones at the end of discharge, permitting the use of a monofunctional air electrode. The improved design had a reduced electrolyte volume on the air side of the cell and better electrical connection to the bed of particles, along with more conveniently located conduits for electrolyte flow driven by natural convection. When discharged at room temperature under the Simplified Federal Urban Driving Schedule (SFUDS) regimen (modified to eliminate regenerative braking) the cell yielded energies that were 2.8 times higher than the original cell (Part I). Increasing the cell temperature (up to 55-degrees-C) was found to bring further improvements. Natural convection was shown to be necessary for good cell performance. C1 UNIV CALIF BERKELEY,DEPT MAT SCI & MINERAL ENGN,BERKELEY,CA 94720. LAWRENCE BERKELEY LAB,BERKELEY,CA 94720. NR 12 TC 15 Z9 15 U1 2 U2 9 PU CHAPMAN HALL LTD PI LONDON PA 2-6 BOUNDARY ROW, LONDON, ENGLAND SE1 8HN SN 0021-891X J9 J APPL ELECTROCHEM JI J. Appl. Electrochem. PD SEP PY 1994 VL 24 IS 9 BP 858 EP 862 DI 10.1007/BF00348772 PG 5 WC Electrochemistry SC Electrochemistry GA PG489 UT WOS:A1994PG48900004 ER PT J AU PATTERSON, EL SAMLIN, GE AF PATTERSON, EL SAMLIN, GE TI LONG-PULSE, ELECTRON-BEAM-PUMPED, ATOMIC XENON LASER SO JOURNAL OF APPLIED PHYSICS LA English DT Article ID PERFORMANCE AB Characteristics of a long-pulse, low pump rate, atomic xenon (XeI) laser are described. Energy loading up to 170 J/L at pulse widths between 5 and 55 ms is achieved with an electron beam in transverse geometry. The fraction of energy in each wavelength obtained with electron beam pumping is in good agreement with results from fission fragment pumping in a reactor pumped laser. Values for the small-signal gain coefficient, loss coefficient, and saturation intensity as a function of pump rate are presented. Laser energy as a function of pulse width and the effects of air and CO2 impurities are described. An investigation of the dominant laser wavelength in a high-Q cavity indicates that the 2.6 mum radiation dominates. RP PATTERSON, EL (reprint author), SANDIA NATL LABS,DEPT LASER & ATOM PHYS,POB 5800,ALBUQUERQUE,NM 87185, USA. NR 19 TC 9 Z9 9 U1 0 U2 0 PU AMER INST PHYSICS PI WOODBURY PA CIRCULATION FULFILLMENT DIV, 500 SUNNYSIDE BLVD, WOODBURY, NY 11797-2999 SN 0021-8979 J9 J APPL PHYS JI J. Appl. Phys. PD SEP 1 PY 1994 VL 76 IS 5 BP 2582 EP 2587 DI 10.1063/1.357553 PG 6 WC Physics, Applied SC Physics GA PD440 UT WOS:A1994PD44000003 ER PT J AU SIMPSON, TW MITCHELL, IV MCCALLUM, JC BOATNER, LA AF SIMPSON, TW MITCHELL, IV MCCALLUM, JC BOATNER, LA TI HYDROGEN CATALYZED CRYSTALLIZATION OF STRONTIUM-TITANATE SO JOURNAL OF APPLIED PHYSICS LA English DT Article ID NUCLEAR-REACTION; SRTIO3 AB The crystallization rate of amorphous strontium titanate is enhanced by more than an order of magnitude during thermal annealing in water vapor as compared to a dry ambient. Time resolved optical reflectivity (TRR) has been combined with Rutherford backscattering spectrometry (RBS) and ion channelling to investigate this effect. Thin amorphous films (0.6 mum) were produced on single-crystal substrates of (100) strontium titanate by bombardment with 1.9 or 2.0 MeV Pb ions. Specimens were annealed under controlled ambient conditions (H2O, D2O, vacuum, 265-430-degrees-C) and the solid phase epitaxial crystallization monitored in situ by TRR (633 nm). The TRR data were calibrated ex situ by transmission electron microscopy and RBS measurements. Isotope substitution, nuclear reaction analysis, and secondary-ion-mass spectrometry were utilized to reveal the uptake of hydrogen and oxygen into the implanted layer. Hydrogen is identified as the only species which penetrates to the crystal/amorphous interface. It is shown that the crystallization rate is proportional to the concentration of diffusing hydrogen (H or D) at the interface. The data show that the effect of water vapor, or more precisely, hydrogen, is to reduce the activation energy of crystallization from 2.1 to 1.0 eV. It is concluded that hydrogen, provided by the dissociation of water molecules at the surface, is a catalyst in the crystallization of amorphous strontium titanate. C1 AUSTRALIAN NATL UNIV,RES SCH PHYS SCI & ENGN,CANBERRA,ACT 0200,AUSTRALIA. OAK RIDGE NATL LAB,DIV SOLID STATE,OAK RIDGE,TN 37831. RP SIMPSON, TW (reprint author), UNIV WESTERN ONTARIO,DEPT PHYS,LONDON N6A 3K7,ONTARIO,CANADA. RI Boatner, Lynn/I-6428-2013 OI Boatner, Lynn/0000-0002-0235-7594 NR 13 TC 20 Z9 20 U1 0 U2 4 PU AMER INST PHYSICS PI WOODBURY PA CIRCULATION FULFILLMENT DIV, 500 SUNNYSIDE BLVD, WOODBURY, NY 11797-2999 SN 0021-8979 J9 J APPL PHYS JI J. Appl. Phys. PD SEP 1 PY 1994 VL 76 IS 5 BP 2711 EP 2718 DI 10.1063/1.357574 PG 8 WC Physics, Applied SC Physics GA PD440 UT WOS:A1994PD44000020 ER PT J AU DICK, JJ RITCHIE, JP AF DICK, JJ RITCHIE, JP TI MOLECULAR MECHANICS MODELING OF SHEAR AND THE CRYSTAL ORIENTATION DEPENDENCE OF THE ELASTIC PRECURSOR SHOCK STRENGTH IN PENTAERYTHRITOL TETRANITRATE SO JOURNAL OF APPLIED PHYSICS LA English DT Article ID FORCE-FIELD; INITIATION; DECAY AB The elastic precursor shock strengths of pentaerythritol tetranitrate explosive crystals were measured for [100], [101], [110], and [001] orientations using velocity interferometer system for any reflector instrumentation for samples 3-6 mm thick. Input shock strength was 1.14 GPa. Measured precursor amplitudes were 0.38, 0.58, 0.98, and 1.22 GPa, respectively, for the four orientations. Critical shear stress for the slip system with the maximum resolved shear stress for each shock orientation was computed. Details of the elastic and plastic wave profiles are discussed. Molecular mechanics modeling of the shear induced by the uniaxial strain of a plane shock wave in this molecular crystal was also performed using the AMBER Code. This may be the first application of molecular mechanics computation to a shear problem. The modeling correctly predicts the dependence of the precursor amplitude on crystal orientation for the cases considered. The results confirm the importance of steric hindrance to shear in controlling the orientation-dependent strength in molecular crystals and sensitivity to shock initiation of detonation in molecular explosive crystals. Details of the molecular deformations and contributions to the energy barrier to inelastic shear for different orientations are given. The computational results also explain why the {110} [111] slip system is observed in quasistatic deformation in spite of having the longest Burgers vector. The dynamics of sterically hindered, shock-induced shear is considered. RP DICK, JJ (reprint author), LOS ALAMOS NATL LAB,LOS ALAMOS,NM 87545, USA. NR 34 TC 94 Z9 100 U1 1 U2 7 PU AMER INST PHYSICS PI WOODBURY PA CIRCULATION FULFILLMENT DIV, 500 SUNNYSIDE BLVD, WOODBURY, NY 11797-2999 SN 0021-8979 J9 J APPL PHYS JI J. Appl. Phys. PD SEP 1 PY 1994 VL 76 IS 5 BP 2726 EP 2737 DI 10.1063/1.357576 PG 12 WC Physics, Applied SC Physics GA PD440 UT WOS:A1994PD44000022 ER PT J AU LEI, M LEDBETTER, H XIE, YF AF LEI, M LEDBETTER, H XIE, YF TI ELASTIC-CONSTANTS OF A MATERIAL WITH ORTHORHOMBIC SYMMETRY - AN ALTERNATIVE MEASUREMENT APPROACH SO JOURNAL OF APPLIED PHYSICS LA English DT Article ID BORON-ALUMINUM; COMPOSITE AB An alternative approach to measuring the complete anisotropic elastic constants c(ij)(s(ij)) of an orthorhombic-symmetry material is proposed. This approach requires measurements along only principal directions: (100). In this approach, a pulse-echo (megahertz-frequency) method was used to measure c11, c22, c33, c44, c55, and c66. A resonance (kilohertz-frequency) method was used to measure three elastic compliances: s11, s22, and s33. Combining the c(ii) with the s(ii), the complete sets of c(ij) and s(ij) were obtained. This approach avoids the troublesome, error-prone determination of off-diagonal c(ij)(s(ij)) by the usual measurements along nonprincipal directions. The approach was applied to a boron-aluminum composite where the off-diagonal terms remain uncertain. In principle, the approach applies to any orthorhombic-symmetry material. C1 NATL INST STAND & TECHNOL,BOULDER,CO 80303. NOAA,BOULDER,CO 80303. RP LEI, M (reprint author), LOS ALAMOS NATL LAB,LOS ALAMOS,NM 87545, USA. RI Xie, Yuanfu/G-4413-2015 NR 10 TC 7 Z9 9 U1 1 U2 3 PU AMER INST PHYSICS PI WOODBURY PA CIRCULATION FULFILLMENT DIV, 500 SUNNYSIDE BLVD, WOODBURY, NY 11797-2999 SN 0021-8979 J9 J APPL PHYS JI J. Appl. Phys. PD SEP 1 PY 1994 VL 76 IS 5 BP 2738 EP 2741 DI 10.1063/1.357577 PG 4 WC Physics, Applied SC Physics GA PD440 UT WOS:A1994PD44000023 ER PT J AU FRIEDMANN, TA MIRKARIMI, PB MEDLIN, DL MCCARTY, KF KLAUS, EJ BOEHME, DR JOHNSEN, HA MILLS, MJ OTTESEN, DK BARBOUR, JC AF FRIEDMANN, TA MIRKARIMI, PB MEDLIN, DL MCCARTY, KF KLAUS, EJ BOEHME, DR JOHNSEN, HA MILLS, MJ OTTESEN, DK BARBOUR, JC TI ION-ASSISTED PULSED-LASER DEPOSITION OF CUBIC BORON-NITRIDE FILMS SO JOURNAL OF APPLIED PHYSICS LA English DT Article ID STRESS-INDUCED FORMATION; DIAMOND-LIKE CARBON; THIN-FILMS; VAPOR-DEPOSITION; BN FILMS; STRUCTURAL CHARACTERIZATION; ROOM-TEMPERATURE; AMORPHOUS-CARBON; SI; IRRADIATION AB Ion-assisted pulsed laser deposition has been used to produce films containing >85% sp3-bonded cubic boron nitride (c-BN). By ablating from a target of hexagonal boron nitride (h-BN), BN films have been deposited on heated (50-800-degrees-C) Si(100) surfaces. The growing films are irradiated with ions from a broad beam ion source operated with Ar and N2 source gasses. Successful c-BN synthesis has been confirmed by Fourier transform infrared (FTIR) spectroscopy, high-resolution transmission electron microscopy (TEM), selected-area electron diffraction, electron energy-loss spectroscopy, and x-ray diffraction. The films are polycrystalline and show grain sizes up to 300 angstrom. In addition, Rutherford backscattering, elastic recoil detection, and Auger electron spectroscopies have been used to further characterize the samples. The effects of varying ion current density, substrate growth temperature, growth time, and ion energy have been investigated. It is found that stoichiometric films with a high c-BN percentage can be grown between 150 and 500-degrees-C. Below approximately 150-degrees-C, the c -BN percentage drops dramatically, and the deposited film is completely resputtered at the current densities and ablation deposition rates used. As the deposition temperature rises above approximately 500-degrees-C the c-BN percentage also drops, but less dramatically than at low temperatures. In addition, the IR-active c-BN mode narrows considerably as the deposition temperature increases, suggesting that the c-BN material has fewer defects or larger grain size. It is found that films with a high c-BN percentage are deposited only in a narrow window of ion/atom arrival values that are near unity at beam energies between 800 and 1200 eV Below this window the deposited films have a low c-BN percentage, and above this window the deposited film is completely resputtered. Using FTIR analysis, it is found that the c-BN percentage in these samples is dependent upon growth time. The initial deposit is essentially all sp2-bonded material and sp3-bonded material forms above this layer. Consistently, cross-section TEM samples reveal this layer to consist of an amorphous BN layer (approximately 30 angstrom thick) directly on the Si substrate followed by highly oriented turbostratic BN (approximately 300 angstrom thick) and finally the c-BN layer. The h-BN/t-BN interfacial layer is oriented with the 002 basal planes perpendicular to the plane of the substrate. Importantly, the position of the c-BN IR phonon changes with growth time. Initially this mode appears near 1130 cm-1 and decreases with growth time to a constant value of 1085 cm-1. Since in bulk c-BN the IR mode appears at 1065 cm-1, a large compressive stress induced by the ion bombardment is suggested. Possible mechanisms are commented on for the conversion process to c-BN based upon the results. C1 SANDIA NATL LABS,LIVERMORE,CA 94551. RP FRIEDMANN, TA (reprint author), SANDIA NATL LABS,ALBUQUERQUE,NM 87185, USA. RI McCarty, Kevin/F-9368-2012 OI McCarty, Kevin/0000-0002-8601-079X NR 66 TC 210 Z9 218 U1 4 U2 45 PU AMER INST PHYSICS PI WOODBURY PA CIRCULATION FULFILLMENT DIV, 500 SUNNYSIDE BLVD, WOODBURY, NY 11797-2999 SN 0021-8979 J9 J APPL PHYS JI J. Appl. Phys. PD SEP 1 PY 1994 VL 76 IS 5 BP 3088 EP 3101 DI 10.1063/1.357491 PG 14 WC Physics, Applied SC Physics GA PD440 UT WOS:A1994PD44000079 ER PT J AU DANDY, DS COLTRIN, ME AF DANDY, DS COLTRIN, ME TI EFFECTS OF TEMPERATURE AND FILAMENT POISONING ON DIAMOND GROWTH IN HOT-FILAMENT REACTORS SO JOURNAL OF APPLIED PHYSICS LA English DT Article ID CHEMICAL-VAPOR-DEPOSITION; H-ATOM CONCENTRATIONS; ROTATING-DISK; ENVIRONMENT; CHEMISTRY; KINETICS; OXYGEN; FLAMES; CH3 AB The growth of diamond in a hot-filament reactor has been modeled, and compared with existing experimental data. Studies have been carried out on non-growth systems containing only hydrogen, as well as on systems where the methane concentration at the inlet was varied between 0.4% and 7.2%. The one-dimensional stagnation flow model used here includes detailed gas-phase and surface kinetics. A simple model of filament poisoning has been implemented. The effect of the gas/filament temperature discontinuity on species distributions has also been examined. Gross errors between theory and experiment are obtained when filament poisoning is neglected, but good agreement is found using a simple linear poisoning model. A nonzero temperature discontinuity at the filament produces good overall agreement with experiment. C1 SANDIA NATL LABS, ALBUQUERQUE, NM 87185 USA. RP COLORADO STATE UNIV, DEPT CHEM ENGN, FT COLLINS, CO 80523 USA. RI Dandy, David/G-6984-2012 OI Dandy, David/0000-0003-3254-0717 NR 33 TC 51 Z9 52 U1 1 U2 5 PU AMER INST PHYSICS PI MELVILLE PA 1305 WALT WHITMAN RD, STE 300, MELVILLE, NY 11747-4501 USA SN 0021-8979 EI 1089-7550 J9 J APPL PHYS JI J. Appl. Phys. PD SEP 1 PY 1994 VL 76 IS 5 BP 3102 EP 3113 DI 10.1063/1.357492 PG 12 WC Physics, Applied SC Physics GA PD440 UT WOS:A1994PD44000080 ER PT J AU KOMVOPOULOS, K WEI, B ANDERS, S ANDERS, A BROWN, IG AF KOMVOPOULOS, K WEI, B ANDERS, S ANDERS, A BROWN, IG TI SURFACE MODIFICATION OF MAGNETIC RECORDING-HEADS BY PLASMA IMMERSION ION-IMPLANTATION AND DEPOSITION (VOL 76, PG 1656, 1994) SO JOURNAL OF APPLIED PHYSICS LA English DT Correction, Addition C1 LAWRENCE BERKELEY LAB,BERKELEY,CA 94720. RP KOMVOPOULOS, K (reprint author), UNIV CALIF BERKELEY,DEPT MECH ENGN,BERKELEY,CA 94720, USA. RI Anders, Andre/B-8580-2009; Raoux, Simone/G-3920-2016 OI Anders, Andre/0000-0002-5313-6505; NR 1 TC 0 Z9 0 U1 0 U2 1 PU AMER INST PHYSICS PI WOODBURY PA CIRCULATION FULFILLMENT DIV, 500 SUNNYSIDE BLVD, WOODBURY, NY 11797-2999 SN 0021-8979 J9 J APPL PHYS JI J. Appl. Phys. PD SEP 1 PY 1994 VL 76 IS 5 BP 3223 EP 3223 DI 10.1063/1.358541 PG 1 WC Physics, Applied SC Physics GA PD440 UT WOS:A1994PD44000101 ER PT J AU FERNANDEZPINAS, F LEGANES, F WOLK, CP AF FERNANDEZPINAS, F LEGANES, F WOLK, CP TI A 3RD GENETIC FOCUS REQUIRED FOR THE FORMATION OF HETEROCYSTS IN ANABAENA SP STRAIN PCC-7120 SO JOURNAL OF BACTERIOLOGY LA English DT Article ID AMINO-ACID SEQUENCE; BLUE-GREEN-ALGA; CYANOBACTERIUM ANABAENA; PATTERN-FORMATION; ESCHERICHIA-COLI; BACTERIAL LUCIFERASE; NUCLEOTIDE-SEQUENCE; NITROGEN-FIXATION; VIBRIO-HARVEYI; PCC-7120 AB Mutagenesis of Anabaena sp. strain PCC 7120 with a derivative of transposon Tn5 led to the isolation of a mutant strain, P6, in which heterocysts are not formed (A. Ernst, T. Black, Y. Cai, J.-M. Panoff, D. N. Tiwari, and C. P. Wolk, J. Bacteriol. 174:6025-6032, 1992). Reconstruction of the transposon mutation of P6 in the wild-type strain reproduced the phenotype of the original mutant. Analysis by pulsed-field gel electrophoresis localized the transposition at ca. 3.44 Mb on the physical map of the chromosome of wild-type Anabaena sp. The transposon was situated within an open reading frame (ORF), which we denote hetP, whose wild-type form was cloned and also sequenced. The predicted HetP protein was not found to show significant sequence similarity to other proteins. The mutation in strain P6 could be complemented by a clone of a fragment of wild-type DNA that includes hetP and at least one additional ORF 3' from hetP, but not by a clone that includes hetP as its only ORF. The latter clone proved highly toxic. The phenotype of the P6 mutant may, therefore, be due to a polar effect of the insertion of the transposon. Filaments of strain P6 and of the wild-type strain, when bearing the complementing fragment on a pDU1-based plasmid, showed an increased frequency of clustered heterocysts compared with that of the wild-type strain. C1 MICHIGAN STATE UNIV,DOE,PLANT RES LAB,E LANSING,MI 48824. OI Fernandez-Pinas, Francisca/0000-0002-7444-7601 NR 46 TC 37 Z9 39 U1 1 U2 2 PU AMER SOC MICROBIOLOGY PI WASHINGTON PA 1325 MASSACHUSETTS AVENUE, NW, WASHINGTON, DC 20005-4171 SN 0021-9193 J9 J BACTERIOL JI J. Bacteriol. PD SEP PY 1994 VL 176 IS 17 BP 5277 EP 5283 PG 7 WC Microbiology SC Microbiology GA PD457 UT WOS:A1994PD45700011 PM 8071202 ER PT J AU LEES, S HANSON, D PAGE, E MOOK, HA AF LEES, S HANSON, D PAGE, E MOOK, HA TI COMPARISON OF DOSAGE-DEPENDENT EFFECTS OF BETA-AMINOPROPIONITRILE, SODIUM-FLUORIDE, AND HYDROCORTISONE ON SELECTED PHYSICAL-PROPERTIES OF CORTICAL BONE SO JOURNAL OF BONE AND MINERAL RESEARCH LA English DT Article ID SONIC PLESIO-VELOCITY; NEUTRON-DIFFRACTION; SEX-DIFFERENCES; RABBIT FEMURS; COMPACT-BONE; COLLAGEN; OSTEOPOROSIS AB BAPN, sodium fluoride, and hydrocortisone are reported to induce altered mineralization states. Three separate sets of experiments, one set for each agent, were performed using male New Zealand white rabbits. In each experiment the rabbits were segregated into groups, each fed a specified weight-determined dose for 13 weeks and then sacrificed. Compact bone from the left femur and tibia were tested for density, composition, sonic velocity, longitudinal elastic modulus, equatorial diffraction spacing of mineralized collagen, diaphyseal cross-sectional area, and relative load stress. P-Aminopropionitrile (BAPN) induced monotonic degradation of all properties at all dose levels, corresponding to the decreasing density with dosage level. The elastic moduli show a decrease; the equatorial diffraction spacing of the collagen increases. The cross-sectioned diaphysis resembled woven bone. The variability in properties increased with dosage. The total cross-sectional area for a given weight increased, implying that the decreased elastic properties were compensated for by a larger area to support the weight. There was a slight increase in average density and other properties for fluoride-treated rabbits, peaking at 20 mg/kg BW/day. For higher dosages the properties are degraded and the values were much lower at high fluoride dosages than for BAPN. There was no peak for the equatorial diffraction spacing, which increased with dosage. It is inferred that the fluorosed apatite is denser than normal apatitic mineral and therefore has a smaller specific volume. A greater weight fraction of fluorosed mineral has a smaller volume fraction than the equivalent normal apatitic mineral. The bone sections look more normal, except for the porosis. The total cross-sectional area decreases when the bone density increases and then increases as the density falls, again implying that the area required to support body weight depends on the magnitude of the elastic moduli. There was a smalt change in some of the properties of the bones of the hydrocortisone-treated rabbits, but the effects on others were undetectable within the uncertainty of the procedures. There was no change in the cross-sectional areas of the diaphyses. C1 FORSYTH DENT CTR,DEPT BIOENGN,BOSTON,MA 02115. OAK RIDGE NATL LAB,OAK RIDGE,TN. FU NIA NIH HHS [AG02325]; NIEHS NIH HHS [ES05064] NR 23 TC 28 Z9 31 U1 0 U2 1 PU BLACKWELL SCIENCE INC PI CAMBRIDGE PA 238 MAIN ST, CAMBRIDGE, MA 02142 SN 0884-0431 J9 J BONE MINER RES JI J. Bone Miner. Res. PD SEP PY 1994 VL 9 IS 9 BP 1377 EP 1389 PG 13 WC Endocrinology & Metabolism SC Endocrinology & Metabolism GA PD706 UT WOS:A1994PD70600008 PM 7817821 ER PT J AU COSMA, G HUBBARD, F JAMASBI, RJ MARCHOK, A GARTE, SJ AF COSMA, G HUBBARD, F JAMASBI, RJ MARCHOK, A GARTE, SJ TI ROLE OF H-RAS IN THE MALIGNANT PROGRESSION OF RAT TRACHEAL EPITHELIAL-CELLS SO JOURNAL OF CANCER RESEARCH AND CLINICAL ONCOLOGY LA English DT Article DE TUMOR PROGRESSION; CELL TRANSFORMATION; RAS ID IMPLANTS EXPOSED INVIVO; ONCOGENE EXPRESSION; CARCINOGENESIS; ACTIVATION; 7,12-DIMETHYLBENZANTHRACENE; HETEROGENEITY; METASTASIS; TUMORS AB The effect of an activated H-ras oncogene on the progression of neoplasia was studied in transformed rat tracheal epithelial cells. Nude mouse tumours produced by injection of these cells exhibited a higher fraction of cells containing the mutant ras gene than did the injected cells, while a subclone that lacked the ras mutation was much less tumorigenic than parental cells. Serial passage of one cell line containing a ras mutation resulted in an increase in the fraction of ras-mutated cells, which suggests that, in this line, ras activation may confer a selective advantage in vitro as well. However, this was not seen in another ras-containing line, suggesting the importance of alternative pathways in malignant progression of rat tracheal epithelial cells. C1 NYU,MED CTR,INST ENVIRONM MED,DEPT ENVIRONM MED,NEW YORK,NY 10016. BOWLING GREEN STATE UNIV,DEPT MED TECHNOL,OAK RIDGE,TN. OAK RIDGE NATL LAB,DIV BIOL,OAK RIDGE,TN 37831. FU NCI NIH HHS [CA 52925, CA 13343]; NIEHS NIH HHS [ES 00260] NR 18 TC 2 Z9 2 U1 0 U2 0 PU SPRINGER VERLAG PI NEW YORK PA 175 FIFTH AVE, NEW YORK, NY 10010 SN 0171-5216 J9 J CANCER RES CLIN JI J. Cancer Res. Clin. Oncol. PD SEP PY 1994 VL 120 IS 11 BP 641 EP 644 DI 10.1007/BF01245374 PG 4 WC Oncology SC Oncology GA PM749 UT WOS:A1994PM74900004 PM 7962039 ER PT J AU KOMAYA, T BELL, AT WENGSIEH, Z GRONSKY, R ENGELKE, F KING, TS PRUSKI, M AF KOMAYA, T BELL, AT WENGSIEH, Z GRONSKY, R ENGELKE, F KING, TS PRUSKI, M TI THE INFLUENCE OF METAL-SUPPORT INTERACTIONS ON THE ACCURATE DETERMINATION OF RU DISPERSION FOR RU/TIO2 SO JOURNAL OF CATALYSIS LA English DT Article ID NUCLEAR MAGNETIC-RESONANCE; ELECTRON-MICROSCOPY; CATALYSTS; TITANIA; MODEL AB Titania-supported Ru catalysts have been characterized by TEM,H-1 NMR, and H-2 chemisorption to determine the metal particle size, the fraction of the metal surface available for H-2 chemisorption, and the H-2 adsorption capacity of the catalyst, as functions of the reduction temperature. TEM micrographs show that as the reduction temperature rises from 573 to 773 K, the average particle size of Ru remains the same but the surface of the particles is covered to an increasing extent by an amorphous layer of titania. Quantitative estimates of the fraction of the Ru particle surface available for H-2 chemisorption were obtained by H-1 NMR. The NMR spectra also show that a fraction of the adsorbed H-2 spills over onto the support and that as a consequence measurements of total H-2 chemisorption overestimate the number of Ru sites available for H-2 adsorption. The implications of these results for the correct calculation of Ru dispersion and the determination of turnover frequencies for reactions carried out over Ru/TiO2 are discussed. (C) 1994 Academic Press, Inc. C1 UNIV CALIF BERKELEY, LAWRENCE BERKELEY LAB, DEPT CHEM ENGN, DIV SCI MAT, BERKELEY, CA 94720 USA. UNIV CALIF BERKELEY, DEPT MAT SCI & MINERAL ENGN, BERKELEY, CA 94720 USA. IOWA STATE UNIV SCI & TECHNOL, AMES LAB, INST PHYS RES & TECHNOL, AMES, IA 50011 USA. IOWA STATE UNIV SCI & TECHNOL, DEPT CHEM ENGN, AMES, IA 50011 USA. MITSUBISHI KASEI CORP, CTR PROT TECHNOL & ENGN, YAKATA NISHI KU, KITAKYUSHU, FUKUOKA 806, JAPAN. RP UNIV CALIF BERKELEY, LAWRENCE BERKELEY LAB, DIV CHEM SCI, BERKELEY, CA 94720 USA. OI Bell, Alexis/0000-0002-5738-4645 NR 17 TC 28 Z9 28 U1 3 U2 10 PU ACADEMIC PRESS INC ELSEVIER SCIENCE PI SAN DIEGO PA 525 B ST, STE 1900, SAN DIEGO, CA 92101-4495 USA SN 0021-9517 EI 1090-2694 J9 J CATAL JI J. Catal. PD SEP PY 1994 VL 149 IS 1 BP 142 EP 148 DI 10.1006/jcat.1994.1279 PG 7 WC Chemistry, Physical; Engineering, Chemical SC Chemistry; Engineering GA PH988 UT WOS:A1994PH98800013 ER PT J AU BOFFA, A LIN, C BELL, AT SOMORJAI, GA AF BOFFA, A LIN, C BELL, AT SOMORJAI, GA TI PROMOTION OF CO AND CO2 HYDROGENATION OVER RH BY METAL-OXIDES - THE INFLUENCE OF OXIDE LEWIS ACIDITY AND REDUCIBILITY SO JOURNAL OF CATALYSIS LA English DT Article ID RAY PHOTOELECTRON-SPECTROSCOPY; SUPPORTED RHODIUM CATALYSTS; CARBON-DIOXIDE; TITANIA OVERLAYERS; SURFACE OXIDATION; THIN-FILMS; XPS; FOIL; METHANATION; VANADIUM AB An investigation has been carried out of CO and CO2 hydrogenation to methane over a Rh foil decorated with submonolayer quantities of AlOx, TiOx, VOx, FeOx, ZrOx, NbOx, TaOx, and WOx. The rate of methane formation was measured at 1 atm and the state of the working catalyst was characterized by XPS immediately after reaction. With the exception of AlOx, each of the oxides was found to enhance the rate of CO methanation relative to that observed over unpromoted Rh. The maximum degree of rate enhancement occurs at an oxide coverage of approximately half a monolayer. AlOx retards the formation of methane in direct proportion to the oxide coverage. FeOx behaves in a manner identical to that of AlOx in the case of CO2 hydrogenation, whereas all of the other oxides studied produce a maximum degree of methanation rate enhancement at an oxide coverage of half a monolayer. The enhancement of CO and CO2 hydrogenation is attributed to the formation of Lewis acid-base complexes between the oxygen end of adsorbed CO (or H2CO formed during the reaction) and anionic vacancies present at the edge of the oxide-metal boundary. The degree of enhancement of CO and CO2 hydrogenation is found to increase with the average oxidation state of the metal in the oxide overlayer. This trend is attributed to the direct relationship between Lewis acidity of an oxide and the oxidation state of the metal in the oxide. The degree of reduction of a given oxide is found to be higher during CO2 hydrogenation than CO hydrogenation. (C) 1994 Academic Press, Inc. C1 UNIV CALIF BERKELEY, DEPT CHEM, BERKELEY, CA 94720 USA. UNIV CALIF BERKELEY, DEPT CHEM ENGN, BERKELEY, CA 94720 USA. RP UNIV CALIF BERKELEY, LAWRENCE BERKELEY LAB, DIV MAT SCI, BERKELEY, CA 94720 USA. OI Bell, Alexis/0000-0002-5738-4645 NR 95 TC 143 Z9 145 U1 6 U2 63 PU ACADEMIC PRESS INC ELSEVIER SCIENCE PI SAN DIEGO PA 525 B ST, STE 1900, SAN DIEGO, CA 92101-4495 USA SN 0021-9517 EI 1090-2694 J9 J CATAL JI J. Catal. PD SEP PY 1994 VL 149 IS 1 BP 149 EP 158 DI 10.1006/jcat.1994.1280 PG 10 WC Chemistry, Physical; Engineering, Chemical SC Chemistry; Engineering GA PH988 UT WOS:A1994PH98800014 ER PT J AU BITTNER, EW BOCKRATH, BC SOLAR, JM AF BITTNER, EW BOCKRATH, BC SOLAR, JM TI THERMAL-ACTIVATION OF SILICA AT TEMPERATURES BELOW 500-DEGREES-C SO JOURNAL OF CATALYSIS LA English DT Article AB A simple low-temperature treatment (below 500 degrees C) of several types of silica was found to induce catalytic activity toward hydrogen-deuterium exchange, the degree of which was measured with a pulse-flow microreactor. Silica samples were heated in a microreactor in the presence of an argon carrier gas. Pulses of hydrogen and deuterium gas mixtures were injected into the flow and the effluent stream was monitored for H-2, D-2, and HD. In some cases equilibrium amounts of the effluent gases were observed. Activation of the silicas appeared to be related to the dehydration of the silica surfaces. After activation, the surface of one of the silicas, Cabosil M5, was found to catalyze the hydrogenation of ethylene to ethane and to catalyze extensive exchange when deuterium was used as the hydrogenation reagent. (C) 1994 Academic Press, Inc. C1 PENN STATE UNIV,MCKEESPORT,PA 15132. RP BITTNER, EW (reprint author), US DOE,PITTSBURGH ENERGY TECHNOL CTR,POB 10940,PITTSBURGH,PA 15236, USA. NR 9 TC 21 Z9 23 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 0021-9517 J9 J CATAL JI J. Catal. PD SEP PY 1994 VL 149 IS 1 BP 206 EP 210 DI 10.1006/jcat.1994.1286 PG 5 WC Chemistry, Physical; Engineering, Chemical SC Chemistry; Engineering GA PH988 UT WOS:A1994PH98800020 ER PT J AU YANG, LQ DEPRISTO, AE AF YANG, LQ DEPRISTO, AE TI ON THE COMPACT STRUCTURE OF SMALL FCC METAL-CLUSTERS SO JOURNAL OF CATALYSIS LA English DT Article ID CORRECTED EFFECTIVE-MEDIUM; MONTE-CARLO SIMULATIONS; MOLECULAR-DYNAMICS; BIMETALLIC CATALYSTS; SURFACE SEGREGATION; BODY FORMULATION; CU; ENERGY; ATOMS; AG AB The general structure of small fcc metal clusters was investigated through the use of site energies, i.e., interaction energy per atom as a function of coordination. We used only experimental data on the dimer binding energy, the surface energy, and the bulk cohesive energy to determine these energies for all 15 fcc metals. These showed that real fcc metal systems exhibit a slight bond weakening as the number of bonds increases. It is also demonstrated that experimental data are much closer to the limit of constant bond energy than to that of constant interaction energy per atom. The constant bond energy model leads to compact structures which maximize the number of bonds, and thus we predicted that real small cluster systems would also be compact. Using molecular dynamics/Monte Carlo corrected effective medium theory, which nearly duplicates the experimental site energy curves, we studied the structures of 13-atom clusters of fcc metals via repeated melting and quenching in computer simulations. The lowest-energy structure was found to be a compact icosahedron with very high symmetry in every case. We also performed such simulations in the presence of a SiO2 support and found that the 13-atom Pt cluster maintained its nearly icosahedral shape. (C) 1994 Academic Press, Inc. C1 IOWA STATE UNIV SCI & TECHNOL,DEPT CHEM,AMES,IA 50011. RP YANG, LQ (reprint author), US DOE,AMES LAB,AMES,IA 50011, USA. NR 31 TC 25 Z9 25 U1 1 U2 5 PU ACADEMIC PRESS INC JNL-COMP SUBSCRIPTIONS PI SAN DIEGO PA 525 B ST, STE 1900, SAN DIEGO, CA 92101-4495 SN 0021-9517 J9 J CATAL JI J. Catal. PD SEP PY 1994 VL 149 IS 1 BP 223 EP 228 DI 10.1006/jcat.1994.1288 PG 6 WC Chemistry, Physical; Engineering, Chemical SC Chemistry; Engineering GA PH988 UT WOS:A1994PH98800022 ER PT J AU RUPNIK, K KLASINC, L VARMA, M BATTISTA, J MCGLYNN, SP AF RUPNIK, K KLASINC, L VARMA, M BATTISTA, J MCGLYNN, SP TI LESION SPECTRA - RADIATION SIGNATURES AND BIOLOGICAL GATEWAYS SO JOURNAL OF CHEMICAL INFORMATION AND COMPUTER SCIENCES LA English DT Article; Proceedings Paper CT 8th Dubrovnik MATH/CHEM/COMP International Course and Conference CY JUN 21-26, 1993 CL ROVINJ, CROATIA SP INT UNIV CTR DUBROVNIK, UNIV ZAGREB, RUGJER BOSKOVIC INST ZAGREB, INT SOC MATH CHEM, INT SOC THEORET CHEM PHYS ID CELLS AB We describe an integrative approach to the modeling of biophysical radiation effects. The model takes aim at practical applications of the knowledge provided by molecular studies of radiation-matter interactions in DNA. The central proposition is the ideat that the distribution of molecular lesions (i.e., a molecular lesion spectrum, MLS) generated in DNA by exposure to a particular radiation is a characteristic of that causal radiation (i.e., is a radiation signature, RS). We have found that adaptive neural networks (ANN's) provide an efficient way to validate that proposition and that ANN's are also likely to be invaluable in any attempt to correlate cancers with radiation types (i.e., with RS's), to use RS's for evaluating individual carcinogenic susceptibilities, and to develop a low-dose personalized monitoring capability. Although efforts to identify products of radiation that are specific to radiation type and to link those with biological responses are almost a century old, the RS concept has provided the first quantitative confirmation of such causal relations. That is, RS's and radiation markers have been identified for various types of radiation, electromagnetic (EM) and particulate, and these signatures and markers may constitute a new way for fast radiation exposure estimates, risk assessment, and cumulative low-dose evaluation. In this work, while we will present a short review of the concepts and methods related to both RS's and markers, almost the entire effort will relate to the modeling and interpretation of RS's using ANN processing. C1 LOUISIANA STATE UNIV,DEPT MICROBIOL,BATON ROUGE,LA 70803. US DOE,WASHINGTON,DC 20585. RP RUPNIK, K (reprint author), LOUISIANA STATE UNIV,DEPT CHEM,BATON ROUGE,LA 70803, USA. NR 19 TC 0 Z9 0 U1 0 U2 0 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 SN 0095-2338 J9 J CHEM INF COMP SCI JI J. Chem. Inf. Comput. Sci. PD SEP-OCT PY 1994 VL 34 IS 5 BP 1054 EP 1063 DI 10.1021/ci00021a004 PG 10 WC Chemistry, Multidisciplinary; Computer Science, Information Systems; Computer Science, Interdisciplinary Applications SC Chemistry; Computer Science GA PJ459 UT WOS:A1994PJ45900005 PM 7962213 ER PT J AU FAULON, JL AF FAULON, JL TI STOCHASTIC GENERATOR OF CHEMICAL-STRUCTURE .1. APPLICATION TO THE STRUCTURE ELUCIDATION OF LARGE MOLECULES SO JOURNAL OF CHEMICAL INFORMATION AND COMPUTER SCIENCES LA English DT Article ID COAL MODEL MOLECULES; BITUMINOUS COAL; ARTIFICIAL-INTELLIGENCE; COMPUTER-SIMULATION; LIGNIN; SYSTEM; SUBSTRUCTURES; INFORMATION; CHEMISTRY; INFERENCE AB This paper presents an original computer-assisted structure elucidation system based on a stochastic approach. Using a randomized technique, it is shown that the number of chemical structures that match a set of analytical data can be approximated in a reasonable computational time. Furthermore, it is demonstrated that a sample of three-dimensional models can be generated and be statistically representative of the entire population of potential models. The analytical data introduced in the system can be derived from experimental techniques as diverse as elemental analysis, functional group analysis,H-1, C-13, and Si-29 NMR, mass spectrometry, pyrolysis, gas chromatography, pycnometry, N-2 and CO2 adsorption, mercury intrusion, and SAXS. The stochastic structure elucidation system is applied to macromolecular compounds that are studied in biochemistry (lignin), geochemistry and fuel science (coal), and material sciences (amorphous silica gel). For these compounds as well as for other amorphous chemical structures cited in the paper the proposed stochastic approach is the first technique that correlates a large diversity of analytical data and three-dimensional molecular models. RP SANDIA NATL LABS, POB 5800, ALBUQUERQUE, NM 87185 USA. NR 69 TC 55 Z9 55 U1 2 U2 11 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 0095-2338 J9 J CHEM INF COMP SCI JI J. Chem. Inf. Comput. Sci. PD SEP-OCT PY 1994 VL 34 IS 5 BP 1204 EP 1218 DI 10.1021/ci00021a031 PG 15 WC Chemistry, Multidisciplinary; Computer Science, Information Systems; Computer Science, Interdisciplinary Applications SC Chemistry; Computer Science GA PJ459 UT WOS:A1994PJ45900032 ER PT J AU MOORE, DS SCHMIDT, SC SHAW, MS AF MOORE, DS SCHMIDT, SC SHAW, MS TI COHERENT ANTI-STOKES-RAMAN SPECTROSCOPY OF SHOCK-COMPRESSED LIQUID NITROGEN/ARGON MIXTURES SO JOURNAL OF CHEMICAL PHYSICS LA English DT Article ID DENSITY DEPENDENCE; MOLECULAR-DYNAMICS; GAIN SPECTROSCOPY; Q-BRANCH; THERMODYNAMICS; OXYGEN; ARGON; SCATTERING; RELAXATION; MONOXIDE AB Single-pulse multiplex coherent anti-Stokes Raman scattering (CARS) was used to obtain vibrational spectra of 20%/80% liquid nitrogen/argon mixtures, shock compressed to several high-pressure/high-temperature states. A semiclassical model for CARS spectra was used to extract best fit vibrational frequencies, peak Raman susceptibilities, and Raman linewidths from the data. Up to a maximum single shock pressure of 17.1 GPa, the N-2 vibrational frequency was found to increase monotonically with pressure. The vibrational frequencies measured in both the singly and doubly shocked N-2/Ar mixtures correspond within experimental error to those for pure nitrogen at equivalent pressures and temperatures, implying that the influence of the interaction potential on the N-2 vibrational frequency for the N-2/Ar collision is not significantly different from that of a N-2/N-2, collision at these conditions. The transition intensity and linewidth data suggest that thermal equilibrium of the vibrational levels is attained in less than 10 ns at these shock pressures. Vibrational temperatures obtained were used to improve the potential function of argon used to calculate equation-of-state pressures and temperatures. The measured linewidths suggest that the nitrogen vibrational dephasing time decreased to about 1 ps at the highest pressure shock state. RP MOORE, DS (reprint author), LOS ALAMOS NATL LAB,POB 1663,LOS ALAMOS,NM 87545, USA. RI Moore, David/C-8692-2013 NR 43 TC 11 Z9 14 U1 1 U2 4 PU AMER INST PHYSICS PI WOODBURY PA CIRCULATION FULFILLMENT DIV, 500 SUNNYSIDE BLVD, WOODBURY, NY 11797-2999 SN 0021-9606 J9 J CHEM PHYS JI J. Chem. Phys. PD SEP 1 PY 1994 VL 101 IS 5 BP 3488 EP 3494 DI 10.1063/1.467533 PG 7 WC Chemistry, Physical; Physics, Atomic, Molecular & Chemical SC Chemistry; Physics GA PE110 UT WOS:A1994PE11000008 ER PT J AU HALL, GE MUCKERMAN, JT PRESES, JM WESTON, RE FLYNN, GW PERSKY, A AF HALL, GE MUCKERMAN, JT PRESES, JM WESTON, RE FLYNN, GW PERSKY, A TI TIME-RESOLVED FOURIER-TRANSFORM INFRARED STUDY OF THE PHOTODISSOCIATION OF 1,1-DIFLUOROETHENE AT 193-NM SO JOURNAL OF CHEMICAL PHYSICS LA English DT Article ID UNIMOLECULAR ELIMINATION-REACTIONS; ROTATIONAL EINSTEIN COEFFICIENTS; VIBRATIONAL DISTRIBUTIONS; FTIR EMISSION; ENERGY-DISTRIBUTIONS; CHEMICAL-REACTION; HYDROGEN HALIDES; O(1D2) REACTIONS; VINYL FLUORIDE; HF AB We have measured vibrational and rotational population distributions for the excited HF product of the 193 nm photolysis of CH2CF2. Approximately 15% of the available energy is released as vibrational energy of HF, and the estimated nascent HF rotational energy corresponds to about 10% of the total available energy. The relative vibrational populations can be fit to a linear surprisal. We have compared the vibrational distribution to that observed from this reaction with different amounts of available energy, and to the HF vibrational distributions produced in the dissociation of other fluoroethenes. While results differ among the various experiments considered, overall more than the amount of vibrational energy expected statistically is deposited in HF. The rotational population distributions we observe fit both a Boltzmann distribution and an information theoretic model corresponding to a nearly statistical energy distribution. C1 COLUMBIA UNIV,DEPT CHEM,NEW YORK,NY 10027. BAR ILAN UNIV,DEPT CHEM,IL-52100 RAMAT GAN,ISRAEL. RP HALL, GE (reprint author), BROOKHAVEN NATL LAB,DEPT CHEM,POB 5000,UPTON,NY 11973, USA. RI Muckerman, James/D-8752-2013; Hall, Gregory/D-4883-2013 OI Hall, Gregory/0000-0002-8534-9783 NR 41 TC 21 Z9 21 U1 0 U2 1 PU AMER INST PHYSICS PI WOODBURY PA CIRCULATION FULFILLMENT DIV, 500 SUNNYSIDE BLVD, WOODBURY, NY 11797-2999 SN 0021-9606 J9 J CHEM PHYS JI J. Chem. Phys. PD SEP 1 PY 1994 VL 101 IS 5 BP 3679 EP 3687 DI 10.1063/1.467552 PG 9 WC Chemistry, Physical; Physics, Atomic, Molecular & Chemical SC Chemistry; Physics GA PE110 UT WOS:A1994PE11000029 ER PT J AU DIAU, EW LIN, MC MELIUS, CF AF DIAU, EW LIN, MC MELIUS, CF TI A THEORETICAL-STUDY OF THE CH3+C2H2 REACTION SO JOURNAL OF CHEMICAL PHYSICS LA English DT Article ID RADICAL REACTIONS; METHYL RADICALS; SHOCK-WAVES; KINETICS; THERMOCHEMISTRY; RECOMBINATION; PYROLYSIS; BENZENE; SYSTEM AB The rate constants for the formation of various products in the CH3+C2H2 reaction have been computed by multichannel RRKM calculations using the molecular and transition-state parameters predicted by the BAC-MP4 method. The results of the calculations agree quantitatively with experimental data obtained under varying conditions: T=300-2200 K, P=30-2500 Torr. At low temperatures (T<1300 K), the CH3+C2H2 reaction is dominated by the addition-stabilization process producing CH3C2H2. Under high-temperature (T>1400 K) and atmospheric-pressure conditions, the reaction occurs primarily by the CH3-for-H displacement process producing CH3C2H, a likely source of the C3H3 radical (which has recently been shown to be a key precursor of C6H6 in hydrocarbon combustion reactions). C1 EMORY UNIV,DEPT CHEM,ATLANTA,GA 30322. SANDIA NATL LABS,COMBUST RES FACIL,LIVERMORE,CA 94550. NR 25 TC 45 Z9 45 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 SEP 1 PY 1994 VL 101 IS 5 BP 3923 EP 3927 DI 10.1063/1.467510 PG 5 WC Chemistry, Physical; Physics, Atomic, Molecular & Chemical SC Chemistry; Physics GA PE110 UT WOS:A1994PE11000056 ER PT J AU GRAY, SK NOID, DW SUMPTER, BG AF GRAY, SK NOID, DW SUMPTER, BG TI SYMPLECTIC INTEGRATORS FOR LARGE-SCALE MOLECULAR-DYNAMICS SIMULATIONS - A COMPARISON OF SEVERAL EXPLICIT METHODS SO JOURNAL OF CHEMICAL PHYSICS LA English DT Article ID HAMILTONIAN-SYSTEMS; POLYETHYLENE; ALGORITHM AB We test the suitability of a variety of explicit symplectic integrators for molecular dynamics calculations on Hamiltonian systems. These integrators are extremely simple algorithms with low memory requirements, and appear to be well suited for large scale simulations. We first apply all the methods to a simple test case using the ideas of Berendsen and van Gunsteren. We then use the integrators to generate long time trajectories of a 1000 unit polyethylene chain. Calculations are also performed with two popular but nonsymplectic integrators. The most efficient integrators of the set investigated are deduced. We also discuss certain variations on the basic symplectic integration technique. C1 OAK RIDGE NATL LAB,DIV CHEM,OAK RIDGE,TN 37831. RP GRAY, SK (reprint author), ARGONNE NATL LAB,DIV CHEM,THEORET CHEM GRP,ARGONNE,IL 60439, USA. RI Sumpter, Bobby/C-9459-2013 OI Sumpter, Bobby/0000-0001-6341-0355 NR 41 TC 110 Z9 111 U1 0 U2 9 PU AMER INST PHYSICS PI WOODBURY PA CIRCULATION FULFILLMENT DIV, 500 SUNNYSIDE BLVD, WOODBURY, NY 11797-2999 SN 0021-9606 J9 J CHEM PHYS JI J. Chem. Phys. PD SEP 1 PY 1994 VL 101 IS 5 BP 4062 EP 4072 DI 10.1063/1.467523 PG 11 WC Chemistry, Physical; Physics, Atomic, Molecular & Chemical SC Chemistry; Physics GA PE110 UT WOS:A1994PE11000071 ER PT J AU SHAPIRO, DB HULL, PG HUNT, AJ HEARST, JE AF SHAPIRO, DB HULL, PG HUNT, AJ HEARST, JE TI CALCULATIONS OF THE MUELLER SCATTERING MATRIX FOR A DNA PLECTONEMIC HELIX SO JOURNAL OF CHEMICAL PHYSICS LA English DT Article ID POLARIZED-LIGHT SCATTERING; INTENSITY DIFFERENTIAL SCATTERING; SUPERCOILED DNA; COMPUTER-SIMULATION; SPECTROSCOPY; ORIENTATION; TOPOLOGY; DYNAMICS AB The polarization state of a beam of light is fully described by the four elements of the Stokes vector. How the Stokes vector is transformed upon scattering is described by the sixteen element Mueller scattering matrix. Polarized light scattering provides a useful tool to study macromolecular structure. In particular, measurements of Mueller matrix elements have been used to study chromosome structure; changes in these measured quantities can be used to monitor structure as a function of cell cycle. Such measurements done on helical structures can be compared to theoretical computations to determine the geometrical parameters describing the helix. The matrix elements that are most sensitive to the chiral parameters of the helix are largest when the wavelength of light is of the order of the pitch of the helix. Therefore, polarized light scattering measurements made on DNA plectonemic helices would provide the most information in the far ultraviolet (UV) and x-ray region. The Mueller matrix elements are calculated using the coupled dipole approximation in the orientation average at wavelengths in the visible, ultraviolet, and x-ray regions. Each base-pair of the idealized plectonemic helix is represented by a single dipole. A complex polarizability tenser is assigned to each dipole. Calculations are sensitive to the writhe and polarizability of the DNA molecule. C1 UNIV CALIF BERKELEY,LAWRENCE BERKELEY LAB,BERKELEY,CA 94720. UNIV CALIF BERKELEY,GRAD GRP BIOPHYS,BERKELEY,CA 94720. TENNESSEE STATE UNIV,DEPT PHYS,NASHVILLE,TN 37209. NR 37 TC 5 Z9 5 U1 1 U2 1 PU AMER INST PHYSICS PI WOODBURY PA CIRCULATION FULFILLMENT DIV, 500 SUNNYSIDE BLVD, WOODBURY, NY 11797-2999 SN 0021-9606 J9 J CHEM PHYS JI J. Chem. Phys. PD SEP 1 PY 1994 VL 101 IS 5 BP 4214 EP 4221 DI 10.1063/1.467471 PG 8 WC Chemistry, Physical; Physics, Atomic, Molecular & Chemical SC Chemistry; Physics GA PE110 UT WOS:A1994PE11000088 ER PT J AU LIU, GY FENTER, P CHIDSEY, CED OGLETREE, DF EISENBERGER, P SALMERON, M AF LIU, GY FENTER, P CHIDSEY, CED OGLETREE, DF EISENBERGER, P SALMERON, M TI AN UNEXPECTED PACKING OF FLUORINATED N-ALKANE THIOLS ON AU(111) - A COMBINED ATOMIC-FORCE MICROSCOPY AND X-RAY-DIFFRACTION STUDY SO JOURNAL OF CHEMICAL PHYSICS LA English DT Article ID GOLD SURFACES; MONOLAYERS; DEPENDENCE AB Atomic force microscopy (AFM) and grazing incidence x-ray diffraction (GIXD) have been used to study the structure of self-assembled monolayers of CF3(CF2)(n)(CH2)(2)SH (n=11, 7, and 5) on the Au(111) surface. Surprisingly, although the nearest-neighbor fluorinated alkane thiol distance is very close to the lattice constant of a commensurate p(2X2) structure, the close-packed rows of molecules are rotated similar to 30 degrees with respect to the underlying gold lattice. That packing is incommensurate or at most only close to the high-order commensurate c(7X7) structure. The relative orientation of the organic monolayer and the Au(111) substrate has been determined unambiguously both with GIXD, and by AFM, taking advantage of an earlier finding (Ref. 1) that AFM tips can reversibly displace the thiol molecules under high loads. In addition, we demonstrate that the two techniques provide complementary information on the order and the domain structures of these monolayers. C1 UNIV CALIF BERKELEY,LAWRENCE BERKELEY LAB,DEPT CHEM,BERKELEY,CA 94720. PRINCETON UNIV,DEPT PHYS,PRINCETON,NJ 08544. STANFORD UNIV,DEPT CHEM,STANFORD,CA 94305. RP LIU, GY (reprint author), UNIV CALIF BERKELEY,LAWRENCE BERKELEY LAB,DIV MAT SCI,BERKELEY,CA 94720, USA. RI Liu, Guang Yu/A-8802-2008; Ogletree, D Frank/D-9833-2016; OI Ogletree, D Frank/0000-0002-8159-0182; Fenter, Paul/0000-0002-6672-9748 NR 23 TC 160 Z9 160 U1 0 U2 13 PU AMER INST PHYSICS PI WOODBURY PA CIRCULATION FULFILLMENT DIV, 500 SUNNYSIDE BLVD, WOODBURY, NY 11797-2999 SN 0021-9606 J9 J CHEM PHYS JI J. Chem. Phys. PD SEP 1 PY 1994 VL 101 IS 5 BP 4301 EP 4306 DI 10.1063/1.467479 PG 6 WC Chemistry, Physical; Physics, Atomic, Molecular & Chemical SC Chemistry; Physics GA PE110 UT WOS:A1994PE11000097 ER PT J AU CHIALVO, AA CUMMINGS, PT AF CHIALVO, AA CUMMINGS, PT TI HYDROGEN-BONDING IN SUPERCRITICAL WATER SO JOURNAL OF CHEMICAL PHYSICS LA English DT Note ID MONTE-CARLO SIMULATIONS; VAPOR COEXISTENCE CURVE; AQUEOUS-SOLUTIONS AB We study the hydrogen bonding structure of water models at supercritical conditions by molecular dynamics to directly compare with recent microstructural data obtained by neutron diffraction with isotopic substitution (NDIS) experiments. We also study the angular dependence of the hydrogen-oxygen pair distribution function to gain insight into the hydrogen bonding mechanism in the molecular models for water. The simulation results suggest that the angle-averaged radial distribution function g(OH)(r) measured by NDIS experiments may not provide a complete picture of the degree of hydrogen bonding. C1 OAK RIDGE NATL LAB,DIV CHEM TECHNOL,OAK RIDGE,TN 37831. RP CHIALVO, AA (reprint author), UNIV TENNESSEE,DEPT CHEM ENGN,419 DOUGHERTY ENGN BLDG,KNOXVILLE,TN 37996, USA. RI Cummings, Peter/B-8762-2013; OI Cummings, Peter/0000-0002-9766-2216; Chialvo, Ariel/0000-0002-6091-4563 NR 14 TC 95 Z9 96 U1 0 U2 10 PU AMER INST PHYSICS PI WOODBURY PA CIRCULATION FULFILLMENT DIV, 500 SUNNYSIDE BLVD, WOODBURY, NY 11797-2999 SN 0021-9606 J9 J CHEM PHYS JI J. Chem. Phys. PD SEP 1 PY 1994 VL 101 IS 5 BP 4466 EP 4469 DI 10.1063/1.467432 PG 4 WC Chemistry, Physical; Physics, Atomic, Molecular & Chemical SC Chemistry; Physics GA PE110 UT WOS:A1994PE11000116 ER PT J AU DAI, S TOTH, LM DELCUL, GD METCALF, DH AF DAI, S TOTH, LM DELCUL, GD METCALF, DH TI ULTRAVIOLET-VISIBLE ABSORPTION-SPECTRUM OF C-60 VAPOR AND DETERMINATION OF THE C-60 VAPORIZATION ENTHALPY SO JOURNAL OF CHEMICAL PHYSICS LA English DT Note ID BUCKMINSTERFULLERENE; FULLERENES; C-70; C60 RP DAI, S (reprint author), OAK RIDGE NATL LAB,DIV CHEM TECHNOL,OAK RIDGE,TN 37831, USA. RI Dai, Sheng/K-8411-2015 OI Dai, Sheng/0000-0002-8046-3931 NR 12 TC 53 Z9 55 U1 0 U2 3 PU AMER INST PHYSICS PI WOODBURY PA CIRCULATION FULFILLMENT DIV, 500 SUNNYSIDE BLVD, WOODBURY, NY 11797-2999 SN 0021-9606 J9 J CHEM PHYS JI J. Chem. Phys. PD SEP 1 PY 1994 VL 101 IS 5 BP 4470 EP 4471 DI 10.1063/1.467433 PG 2 WC Chemistry, Physical; Physics, Atomic, Molecular & Chemical SC Chemistry; Physics GA PE110 UT WOS:A1994PE11000117 ER PT J AU POLMAN, JK MILLER, KS STONER, DL BRECKENRIDGE, CR AF POLMAN, JK MILLER, KS STONER, DL BRECKENRIDGE, CR TI SOLUBILIZATION OF BITUMINOUS AND LIGNITE COALS BY CHEMICALLY AND BIOLOGICALLY SYNTHESIZED SURFACTANTS SO JOURNAL OF CHEMICAL TECHNOLOGY AND BIOTECHNOLOGY LA English DT Article DE COAL; SURFACTANT; BACILLUS-LICHENIFORMIS; TWEEN; TRITON; SODIUM DODECYL SULFATE ID MICROORGANISMS; BIOSURFACTANT AB Tween 80 (polyoxyethylene sorbitan monooleate), Triton X-100 (non-aethylene glycol octylphenol ether), and SDS (sodium dodecyl sulfate) solubilized several components of Mississippi Wilcox lignite and Illinois No. 6 bituminous coal. Tween 80 extraction of alkali-soluble Ugljevik lignite resulted in an increase in hydrogen content and decreases in the nitrogen and sulfur contents of undissolved coal solids. Biosurfactant-containing cell-free extracts of Bacillus licheniformis solubilized a 53 000 Da coal component of Mississippi Wilcox lignite. The results suggest that solubilization of coal organic components by chemically- and biologically-synthesized surfactants has potential in terms of upgrading coals. RP POLMAN, JK (reprint author), EG&G IDAHO INC,IDAHO NATL ENGN LAB,IND BIOTECHNOL & PROCESS ENGN,IDAHO FALLS,ID 83415, USA. NR 25 TC 15 Z9 15 U1 1 U2 3 PU JOHN WILEY & SONS LTD PI W SUSSEX PA BAFFINS LANE CHICHESTER, W SUSSEX, ENGLAND PO19 1UD SN 0268-2575 J9 J CHEM TECHNOL BIOT JI J. Chem. Technol. Biotechnol. PD SEP PY 1994 VL 61 IS 1 BP 11 EP 17 DI 10.1002/jctb.280610103 PG 7 WC Biotechnology & Applied Microbiology; Chemistry, Multidisciplinary; Engineering, Environmental; Engineering, Chemical SC Biotechnology & Applied Microbiology; Chemistry; Engineering GA PF546 UT WOS:A1994PF54600002 ER PT J AU WANG, RY ASHBY, CR EDWARDS, E ZHANG, JY AF WANG, RY ASHBY, CR EDWARDS, E ZHANG, JY TI THE ROLE OF 5-HT(3)-LIKE RECEPTORS IN THE ACTION OF CLOZAPINE SO JOURNAL OF CLINICAL PSYCHIATRY LA English DT Article; Proceedings Paper CT Symposium-Clozapine 1994 CY FEB 25-26, 1994 CL GARDEN CITY, NY ID ATYPICAL ANTIPSYCHOTIC-DRUGS; 5-HT3 RECOGNITION SITES; RAT-BRAIN; RADIOLIGAND BINDING; NUCLEUS-ACCUMBENS; CEREBRAL-CORTEX; AGONIST; HYDROLYSIS; DOPAMINE; RELEASE AB The serotonin3 (5-HT3)-like receptors play an important role in modulating the inhibitory action of dopamine in the mesocorticolimbic regions. The atypical antipsychotic drugs clozapine and RMI 81,582, but not other antipsychotic drugs, blocked the suppressant action produced by the 5-HT3 receptor agonist 2-methyl-5-HT on the firing rate of medial prefrontal cortical cells. Since the localization of 5-HT3 receptors overlaps with the mesocorticolimbic but not the nigrostriatal dopamine system, it is hypothesized that the preferential action of clozapine on the mesocorticolimbic dopamine system is the result of the drug's interaction with the 5-HT3-like receptors. Furthermore, the antagonizing effect of clozapine to 5-HT3-like receptors may contribute to its increased antipsychotic efficacy. C1 BROOKHAVEN NATL LAB,DEPT MED,UPTON,NY 11973. UNIV MARYLAND,DEPT PHARMACEUT SCI,BALTIMORE,MD 21201. RP WANG, RY (reprint author), SUNY STONY BROOK,DEPT PSYCHIAT & BEHAV SCI,STONY BROOK,NY 11794, USA. FU NIDA NIH HHS [DA-07193]; NIMH NIH HHS [MH-41440] NR 32 TC 12 Z9 13 U1 0 U2 0 PU PHYSICIANS POSTGRADUATE PRESS PI MEMPHIS PA P O BOX 240008, MEMPHIS, TN 38124 SN 0160-6689 J9 J CLIN PSYCHIAT JI J. Clin. Psychiatry PD SEP PY 1994 VL 55 IS 9 SU B BP 23 EP 26 PG 4 WC Psychology, Clinical; Psychiatry SC Psychology; Psychiatry GA PQ450 UT WOS:A1994PQ45000004 PM 7961566 ER PT J AU BRACKBILL, JU LAPENTA, G AF BRACKBILL, JU LAPENTA, G TI A METHOD TO SUPPRESS THE FINITE-GRID INSTABILITY IN PLASMA SIMULATIONS SO JOURNAL OF COMPUTATIONAL PHYSICS LA English DT Article ID IMPLICIT AB A technique for suppressing the finite-grid instability in plasma simulation by jiggling the computation mesh is revisited. Linear dispersion theory suggests a reduction in growth rate of 50% when the mesh is randomly jiggled. With an implicit method, a large time step, and a grid with variable spacing, a nearly complete absence of the instability is observed. Because of its simplicity and low cost, it is suggested the method can be used routinely with variable zoning or adaptive grids to suppress the finite-grid instability. (C) 1994 Academic Press, Inc. C1 POLITECN TORINO, I-10128 TURIN, ITALY. RP BRACKBILL, JU (reprint author), LOS ALAMOS NATL LAB, LOS ALAMOS, NM 87544 USA. NR 13 TC 5 Z9 5 U1 0 U2 0 PU ACADEMIC PRESS INC ELSEVIER SCIENCE PI SAN DIEGO PA 525 B ST, STE 1900, SAN DIEGO, CA 92101-4495 USA SN 0021-9991 J9 J COMPUT PHYS JI J. Comput. Phys. PD SEP PY 1994 VL 114 IS 1 BP 77 EP 84 DI 10.1006/jcph.1994.1150 PG 8 WC Computer Science, Interdisciplinary Applications; Physics, Mathematical SC Computer Science; Physics GA PB272 UT WOS:A1994PB27200007 ER PT J AU SIDIKMAN, KL CARRERAS, BA GARCIA, L AF SIDIKMAN, KL CARRERAS, BA GARCIA, L TI DRIFT-WAVE TURBULENCE IN A PLASMA WITH SHEARED FLOW SO JOURNAL OF COMPUTATIONAL PHYSICS LA English DT Article ID L-H TRANSITION; POLOIDAL ROTATION; MAGNETIC-FIELD; TOKAMAK AB A single-equation model of long-wavelength drift waves has been used to study the behavior of turbulent plasma fluctuations in the presence of sheared flow. These waves, which have a real frequency, are calculated using a time-evolution algorithm that includes flow effects. Linear tests show that growth rates and flow-shear damping agree with the predictions of analytical theory, even in the presence of a large real frequency. Criteria for selecting the proper spatial and temporal resolution for nonlinear calculations are described. Convergence tests show that, within these limits, solutions have a weak dependence on variations of thess resolution parameters. Tests of energy conservation indicate that calculated solutions remain accurate for large numbers of time steps. (C) 1994 Academic Press, Inc. C1 UNIV CARLOS 3,MADRID,SPAIN. RP SIDIKMAN, KL (reprint author), OAK RIDGE NATL LAB,OAK RIDGE,TN 37831, USA. RI Garcia, Luis/A-5344-2015 OI Garcia, Luis/0000-0002-0492-7466 NR 15 TC 1 Z9 1 U1 0 U2 0 PU ACADEMIC PRESS INC JNL-COMP SUBSCRIPTIONS PI SAN DIEGO PA 525 B ST, STE 1900, SAN DIEGO, CA 92101-4495 SN 0021-9991 J9 J COMPUT PHYS JI J. Comput. Phys. PD SEP PY 1994 VL 114 IS 1 BP 100 EP 112 DI 10.1006/jcph.1994.1152 PG 13 WC Computer Science, Interdisciplinary Applications; Physics, Mathematical SC Computer Science; Physics GA PB272 UT WOS:A1994PB27200009 ER PT J AU LEE, JH VERHOEVEN, JD AF LEE, JH VERHOEVEN, JD TI THE NATURE OF UNUSUAL GAMMA'/GAMMA' INTERFACES FORMED UPON QUENCHING DIRECTIONALLY SOLIDIFYING NI3AL ALLOYS SO JOURNAL OF CRYSTAL GROWTH LA English DT Article AB Upon quenching directionally solidified Ni-Al alloys having compositions near the Ni3Al compound, two distinct and unusual interfaces (No. I and No. II) occur in the region of the solid-liquid growth front. The interfaces appear after etching in a variety of etchants or with an ion beam or after electro-polishing. Both interfaces are gamma'/gamma' interfaces. Experiments are presented which show that during the quench a band of gamma' phase forms upon the solid growth front, and interface No. II marks the top of the band, while interface No. I marks the bottom of the band where it overgrows freezing gamma'. It is also shown that both interfaces result from local planar shaped regions of composition change. Interface No. II is mainly an interesting experimental observation, but interface No. I should be very useful in experiments involving growth of gamma' because it marks the location of the solid-liquid growth front. C1 IOWA STATE UNIV SCI & TECHNOL,AMES LAB,DEPT MAT SCI & ENGN,AMES,IA 50011. NR 8 TC 9 Z9 9 U1 1 U2 2 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0022-0248 J9 J CRYST GROWTH JI J. Cryst. Growth PD SEP PY 1994 VL 142 IS 1-2 BP 193 EP 208 DI 10.1016/0022-0248(94)90288-7 PG 16 WC Crystallography; Materials Science, Multidisciplinary; Physics, Applied SC Crystallography; Materials Science; Physics GA PE509 UT WOS:A1994PE50900027 ER PT J AU LOWNDES, DH NORTON, DP AF LOWNDES, DH NORTON, DP TI EXPERIMENTAL INVESTIGATIONS OF SUPERCONDUCTIVITY IN QUASI-2-DIMENSIONAL EPITAXIAL COPPER-OXIDE SUPERLATTICES AND TRILAYERS SO JOURNAL OF ELECTRONIC MATERIALS LA English DT Article; Proceedings Paper CT Symposium on Synthesis and Processing of Electronic and Photonic Materials CY FEB, 1993 CL DENVER, CO SP MINERALS MET & MAT SOC DE FILM-FLOW RESISTANCE; FILM-GROWTH MECHANISMS; GINZBURG-LANDAU COULOMB GAS; LASER ABLATION FILM GROWTH; SUPERCONDUCTIVITY; SUPERLATTICES; TRILAYERS; VORTICES ID HIGH-TC SUPERCONDUCTORS; TWO-DIMENSIONAL SUPERCONDUCTORS; KOSTERLITZ-THOULESS TRANSITION; YBA2CU3O7-X/PRBA2CU3O7-X SUPERLATTICES; THIN-FILMS; VORTEX FLUCTUATIONS; SINGLE-CRYSTALS; COULOMB-GAS; YBA2CU3O7-DELTA; GROWTH AB Epitaxial trilayer and superlattice structures grown by pulsed laser ablation have been used to study the superconducting-to-normal transition of ultrathin (one and two c-axis unit cells) YBa2Cu3O7-x layers. The normalized flux-flow resistances for several epitaxial structures containing two-cell-thick YBa2Cu3O7-x films collapse onto the ''universal'' curve of the Ginzburg-Landau Coulomb gas (GLCG) model. Analysis of normalized resistance data for a series of superlattices containing one-cell-thick YBa2Cu3O7-x layers also is consistent with the behavior expected for quasi-two-dimensional layers in a highly anisotropic, layered three-dimensional superconductor. Current-voltage measurements for one of the trilayer structures also are consistent with the normalized resistance data, and with the GLCG model. Scanning tunneling microscopy, transmission electron microscopy, and electrical transport studies show that growth-related steps in ultrathin YBa2Cu3O7-x layers affect electrical continuity over macroscopic distances, acting as weak links. However, the perturbation of the superconducting order parameter can be minimized by utilizing hole-doped buffer and cap layers, on both sides of the YBa2Cu3O7-x layer, in trilayers and superlattices. These results demonstrate the usefulness of epitaxial trilayer and superlattice structures as tools for systematic, fundamental studies of high-temperature superconductivity. RP LOWNDES, DH (reprint author), OAK RIDGE NATL LAB,POB 2008,OAK RIDGE,TN 37831, USA. NR 39 TC 2 Z9 2 U1 0 U2 2 PU MINERALS METALS MATERIALS SOC PI WARRENDALE PA 420 COMMONWEALTH DR, WARRENDALE, PA 15086 SN 0361-5235 J9 J ELECTRON MATER JI J. Electron. Mater. PD SEP PY 1994 VL 23 IS 9 BP 841 EP 847 DI 10.1007/BF02655353 PG 7 WC Engineering, Electrical & Electronic; Materials Science, Multidisciplinary; Physics, Applied SC Engineering; Materials Science; Physics GA PF342 UT WOS:A1994PF34200002 ER PT J AU TIWARI, P ZHELEVA, T NARAYAN, J AF TIWARI, P ZHELEVA, T NARAYAN, J TI SYNTHESIS AND CHARACTERIZATION OF PB(ZR0.54TI0.46)O3 THIN-FILMS ON (100)SI USING TEXTURED YBA2CU3O7-DELTA AND YTTRIA-STABILIZED ZIRCONIA BUFFER LAYERS BY LASER PHYSICAL VAPOR-DEPOSITION TECHNIQUE SO JOURNAL OF ELECTRONIC MATERIALS LA English DT Article; Proceedings Paper CT Symposium on Synthesis and Processing of Electronic and Photonic Materials CY FEB, 1993 CL DENVER, CO SP MINERALS MET & MAT SOC DE EPITAXY; FERROELECTRICS; LASER ABLATION; MULTILAYERS ID BA-CU-O; EVAPORATION TECHNIQUE; ABLATION AB We have fabricated high-quality [001] textured Pb(Zr0.54Ti0.46)O3 (PZT) thin films on (001)Si with interposing [001] texture YBa2Cu3O7-delta (YBCO) and yttria-stabilized zirconia (YSZ) buffer layers using pulsed laser deposition (KrF excimer laser, lambda = 248 nm, tau = 20 nanosecs). The YBCO layer provides a seed for PZT growth and can also act as an electrode for the PZT films, whereas YSZ provides a diffusion barrier as well as a seed for the growth of YBCO films on (001)Si. These heterostructures were characterized using x-ray diffraction, high-resolution transmission electron microscopy, and Rutherford backscattering techniques. The YSZ films were deposited in oxygen ambient (approximately 9 x 10(-4) Torr) at 775-degrees-C on (001)Si substrate having [001]YSZ\\[001]Si texture. The YBCO thin films were deposited in-situ in oxygen ambient (200 mTorr) at 650-degrees-C. The temperature and oxygen ambient for the PZT deposition were optimized to be 530-degrees-C and 0.4-0.6 Torr, respectively. The laser fluence to deposit this multilayer structure was 2.5-5.0 J/cm2. The [001] textured perovskite PZT films showed a dielectric constant of 800-1000, a saturation polarization of 37.81 muC/cm2, remnant polarization of 24.38 muC/cm2 and a coercive field of 125 kV/cm. The effects of processing parameters on microstructure and ferroelectric properties of PZT films and device implications of these structures are discussed. C1 N DAKOTA STATE UNIV,DEPT MAT SCI & ENGN,FARGO,ND 58105. RP TIWARI, P (reprint author), LOS ALAMOS NATL LAB,CTR SUPERCOND TECHNOL,LOS ALAMOS,NM 87545, USA. RI Narayan, Jagdish/D-1874-2009 NR 21 TC 3 Z9 3 U1 0 U2 1 PU MINERALS METALS MATERIALS SOC PI WARRENDALE PA 420 COMMONWEALTH DR, WARRENDALE, PA 15086 SN 0361-5235 J9 J ELECTRON MATER JI J. Electron. Mater. PD SEP PY 1994 VL 23 IS 9 BP 879 EP 882 DI 10.1007/BF02655358 PG 4 WC Engineering, Electrical & Electronic; Materials Science, Multidisciplinary; Physics, Applied SC Engineering; Materials Science; Physics GA PF342 UT WOS:A1994PF34200007 ER PT J AU MCELIGOT, J MCELIGOT, DM AF MCELIGOT, J MCELIGOT, DM TI PERSPECTIVE - SOME RESEARCH NEEDS IN CONVECTIVE HEAT-TRANSFER FOR INDUSTRY SO JOURNAL OF FLUIDS ENGINEERING-TRANSACTIONS OF THE ASME LA English DT Article ID ALGORITHMS; EJECTION; DYNAMICS C1 EG&G IDAHO INC,IDAHO NATL ENGN LAB,IDAHO FALLS,ID 83415. UNIV ARIZONA,TUCSON,AZ 85721. NR 55 TC 4 Z9 4 U1 0 U2 0 PU ASME-AMER SOC MECHANICAL ENG PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 SN 0098-2202 J9 J FLUID ENG-T ASME JI J. Fluids Eng.-Trans. ASME PD SEP PY 1994 VL 116 IS 3 BP 398 EP 404 DI 10.1115/1.2910290 PG 7 WC Engineering, Mechanical SC Engineering GA PK459 UT WOS:A1994PK45900004 ER PT J AU RUSSO, RE PELKEY, GE GRANT, P WHIPPLE, RE ANDRESEN, BD AF RUSSO, RE PELKEY, GE GRANT, P WHIPPLE, RE ANDRESEN, BD TI LASER INTERROGATION OF LATENT VEHICLE REGISTRATION NUMBER SO JOURNAL OF FORENSIC SCIENCES LA English DT Note DE FORENSIC SCIENCE; LASER ILLUMINATION; VEHICLE REGISTRATION DECALS ID SPECTROSCOPY AB Optimally tuned laser light illumination through the back of multilayered license-plate decals provided nondestructive absolute identification of a latent registration number. C1 UNIV CALIF BERKELEY,LAWRENCE BERKELEY LAB,DIV ENERGY & ENVIRONM,BERKELEY,CA 94720. CITY LIVERMORE POLICE DEPT,LIVERMORE,CA. RP RUSSO, RE (reprint author), LAWRENCE LIVERMORE NATL LAB,CTR FORENS SCI,L-371,LIVERMORE,CA 94550, USA. NR 8 TC 1 Z9 1 U1 0 U2 0 PU AMER SOC TESTING MATERIALS PI W CONSHOHOCKEN PA 100 BARR HARBOR DR, W CONSHOHOCKEN, PA 19428-2959 SN 0022-1198 J9 J FORENSIC SCI JI J. Forensic Sci. PD SEP PY 1994 VL 39 IS 5 BP 1331 EP 1334 PG 4 WC Medicine, Legal SC Legal Medicine GA PH967 UT WOS:A1994PH96700027 ER PT J AU RUTHERFORD, PH AF RUTHERFORD, PH TI INITIAL ACTIVITIES OF THE ITER TECHNICAL ADVISORY-COMMITTEE SO JOURNAL OF FUSION ENERGY LA English DT Editorial Material RP RUTHERFORD, PH (reprint author), PRINCETON UNIV,PLASMA PHYS LAB,POB 451,PRINCETON,NJ 08543, USA. NR 0 TC 1 Z9 1 U1 0 U2 0 PU PLENUM PUBL CORP PI NEW YORK PA 233 SPRING ST, NEW YORK, NY 10013 SN 0164-0313 J9 J FUSION ENERG JI J. Fusion Energy PD SEP PY 1994 VL 13 IS 2-3 BP 83 EP 84 DI 10.1007/BF02213937 PG 2 WC Nuclear Science & Technology SC Nuclear Science & Technology GA QP932 UT WOS:A1994QP93200004 ER PT J AU BALDWN, DE AF BALDWN, DE TI REPORT OF ITER SPECIAL WORKING GROUP SO JOURNAL OF FUSION ENERGY LA English DT Editorial Material RP BALDWN, DE (reprint author), LAWRENCE LIVERMORE NATL LAB,POB 808,L-640,LIVERMORE,CA 94551, USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU PLENUM PUBL CORP PI NEW YORK PA 233 SPRING ST, NEW YORK, NY 10013 SN 0164-0313 J9 J FUSION ENERG JI J. Fusion Energy PD SEP PY 1994 VL 13 IS 2-3 BP 85 EP 87 DI 10.1007/BF02213938 PG 3 WC Nuclear Science & Technology SC Nuclear Science & Technology GA QP932 UT WOS:A1994QP93200005 ER PT J AU ROBERTS, M AF ROBERTS, M TI REPORT OF ITER SPECIAL WORKING GROUP-2 SO JOURNAL OF FUSION ENERGY LA English DT Editorial Material RP ROBERTS, M (reprint author), US DOE,OFF FUS ENERGY ER52,WASHINGTON,DC 20585, USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU PLENUM PUBL CORP PI NEW YORK PA 233 SPRING ST, NEW YORK, NY 10013 SN 0164-0313 J9 J FUSION ENERG JI J. Fusion Energy PD SEP PY 1994 VL 13 IS 2-3 BP 89 EP 90 DI 10.1007/BF02213939 PG 2 WC Nuclear Science & Technology SC Nuclear Science & Technology GA QP932 UT WOS:A1994QP93200006 ER PT J AU CRANDALL, DH AF CRANDALL, DH TI OVERVIEW OF US FUSION ENERGY PROGRAMS - JANUARY 1993 SO JOURNAL OF FUSION ENERGY LA English DT Editorial Material RP CRANDALL, DH (reprint author), US DOE,OFF FUS ENERGY ER54,WASHINGTON,DC 20585, USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU PLENUM PUBL CORP PI NEW YORK PA 233 SPRING ST, NEW YORK, NY 10013 SN 0164-0313 J9 J FUSION ENERG JI J. Fusion Energy PD SEP PY 1994 VL 13 IS 2-3 BP 103 EP 104 DI 10.1007/BF02213944 PG 2 WC Nuclear Science & Technology SC Nuclear Science & Technology GA QP932 UT WOS:A1994QP93200011 ER PT J AU BANGERTER, RO AF BANGERTER, RO TI THE PROMISE OF HEAVY-ION FUSION SO JOURNAL OF FUSION ENERGY LA English DT Article RP BANGERTER, RO (reprint author), UNIV CALIF BERKELEY,LAWRENCE BERKELEY LAB,BERKELEY,CA 94720, USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU PLENUM PUBL CORP PI NEW YORK PA 233 SPRING ST, NEW YORK, NY 10013 SN 0164-0313 J9 J FUSION ENERG JI J. Fusion Energy PD SEP PY 1994 VL 13 IS 2-3 BP 121 EP 123 DI 10.1007/BF02213947 PG 3 WC Nuclear Science & Technology SC Nuclear Science & Technology GA QP932 UT WOS:A1994QP93200014 ER PT J AU THOMASSEN, KI AF THOMASSEN, KI TI INDUSTRY ROLES IN THE TOKAMAK PHYSICS EXPERIMENT SO JOURNAL OF FUSION ENERGY LA English DT Article RP THOMASSEN, KI (reprint author), UNIV CALIF LAWRENCE LIVERMORE NATL LAB,POB 808 L-637,LIVERMORE,CA 94551, USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU PLENUM PUBL CORP PI NEW YORK PA 233 SPRING ST, NEW YORK, NY 10013 SN 0164-0313 J9 J FUSION ENERG JI J. Fusion Energy PD SEP PY 1994 VL 13 IS 2-3 BP 127 EP 130 DI 10.1007/BF02213949 PG 4 WC Nuclear Science & Technology SC Nuclear Science & Technology GA QP932 UT WOS:A1994QP93200016 ER PT J AU HARRI, JG PAISNER, JA LOWDERMILK, WH BOYES, JD KUMPAN, SA SOREM, MS AF HARRI, JG PAISNER, JA LOWDERMILK, WH BOYES, JD KUMPAN, SA SOREM, MS TI THE NATIONAL IGNITION FACILITY AND INDUSTRY SO JOURNAL OF FUSION ENERGY LA English DT Article DE INERTIAL CONFINEMENT FUSION TARGETS; DIRECT DRIVE TARGETS; SOLID-STATE LASER DRIVE AB The mission of the National Ignition Facility is to achieve ignition and gain in inertial confinement fusion targets in the laboratory. The facility will be used for defense applications such as weapons physics and weapons effects testing, and for civilian applications such as fusion energy development and fundamental studies of matter at high temperatures and densities. The National Ignition Facility construction project will require the best of our construction industries and its success will depend on the best products offered by hundreds of the nation's high technology companies. Three-fourths of the construction costs will be invested in industry. This article reviews the design, cost and schedule, and required industrial involvement associated with the construction project. RP HARRI, JG (reprint author), LAWRENCE LIVERMORE NATL LAB,POB 808,L-466,LIVERMORE,CA 94550, USA. NR 0 TC 1 Z9 1 U1 2 U2 3 PU PLENUM PUBL CORP PI NEW YORK PA 233 SPRING ST, NEW YORK, NY 10013 SN 0164-0313 J9 J FUSION ENERG JI J. Fusion Energy PD SEP PY 1994 VL 13 IS 2-3 BP 137 EP 143 DI 10.1007/BF02213951 PG 7 WC Nuclear Science & Technology SC Nuclear Science & Technology GA QP932 UT WOS:A1994QP93200018 ER PT J AU MEADE, DM AF MEADE, DM TI D-T EXPERIMENTS ON TFTR SO JOURNAL OF FUSION ENERGY LA English DT Article DE DEUTERIUM-TRITIUM (D-T) FUEL; TOKAMAK FUSION TEST REACTOR (TFTR); BEAM PARAMETERS AB Temperatures, densities and confinement of deuterium plasmas confined in tokamaks have been achieved within the last decade that are approaching those required for a D-T reactor. As a result, the unique phenomena present in a D-T reactor plasma (D-T plasma confinement, alpha confinement, alpha heating and possible alpha driven instabilities) can now be studied in the laboratory. Recent experiments on the Tokamak Fusion Test Reactor (TFTR) have been the first magnetic fusion experiments to study plasmas with reactor fuel concentrations of tritium. The injection of similar to 20 MW of tritium and 14 MW of deuterium neutral beams into the TFTR produced a plasma with a T/D density ratio of similar to 1 and yielded a maximum fusion power of similar to 9.2 MW. The fusion power density in the core of the plasma was similar to 1.8 MW m(-3) approximating that expected in a D-T fusion reactor. In other experiments TFTR has produced 6.4 MJ of fusion energy in one pulse satisfying the original 1976 goal of producing 1 to 10 MJ of fusion energy per pulse. A TFTR plasma with T/D density ratio of similar to 1 was found to have similar to 20% higher energy confinement time than a comparable D plasma, indicating a confinement scaling with average ion mass, A, of tau(E) similar to A(0.6). The core ion temperature increased from 30 keV to 37 keV due to a 35% improvement of ion thermal conductivity. Using the electron thermal conductivity from a comparable deuterium plasma, about 50% of the electron temperature increase from 9 keV to 10.6 keV can be attributed to electron heating by the alpha particles. At fusion power levels of 7.5 MW, fluctuations at the Toroidal Alfven Eigenmode frequency were observed by the fluctuation diagnostics. However, no additional alpha loss due to the fluctuations was observed. These D-T experiments will continue over a broader range of parameters and higher power levels. RP MEADE, DM (reprint author), PRINCETON UNIV,PLASMA PHYS LAB,POB 451,PRINCETON,NJ 08543, USA. NR 0 TC 1 Z9 1 U1 0 U2 0 PU PLENUM PUBL CORP PI NEW YORK PA 233 SPRING ST, NEW YORK, NY 10013 SN 0164-0313 J9 J FUSION ENERG JI J. Fusion Energy PD SEP PY 1994 VL 13 IS 2-3 BP 145 EP 154 DI 10.1007/BF02213952 PG 10 WC Nuclear Science & Technology SC Nuclear Science & Technology GA QP932 UT WOS:A1994QP93200019 ER PT J AU ROSEN, MD LINDL, JD KILKENNY, JD AF ROSEN, MD LINDL, JD KILKENNY, JD TI RECENT RESULTS ON NOVA SO JOURNAL OF FUSION ENERGY LA English DT Article DE LASER HEATED HOHLRAUMS; LASER DRIVEN INDIRECT DRIVE IGNITION; LATERAL ELECTRON CONDUCTION SMOOTHING AB On the Nova Laser at LLNL, we have recently demonstrated many of the key elements required for assuring that the next proposed laser, the National Ignition Facility (NIF) will reach ignition. In particular, we have achieved a drive of 300 eV in laser heated hohlraums; have shown good understanding and control of symmetry in hohlruams; created large NIF-Scale plasmas with plasma and irradiation conditions relevant to NIF targets that showed low levels of plasma instabilities; demonstrated a good understanding of hydrodynamic instability and subsequent pusher/fuel mix in implosions by means of spectroscopic tracers; and performed integrated implosion experiments that have performed well even under stringent convergences of order 25, which is well into the NIF ignition target regime. RP ROSEN, MD (reprint author), LAWRENCE LIVERMORE NATL LAB,POB 5508,L-477,LIVERMORE,CA 94550, USA. NR 0 TC 2 Z9 2 U1 2 U2 2 PU PLENUM PUBL CORP PI NEW YORK PA 233 SPRING ST, NEW YORK, NY 10013 SN 0164-0313 J9 J FUSION ENERG JI J. Fusion Energy PD SEP PY 1994 VL 13 IS 2-3 BP 155 EP 166 DI 10.1007/BF02213953 PG 12 WC Nuclear Science & Technology SC Nuclear Science & Technology GA QP932 UT WOS:A1994QP93200020 ER PT J AU SHEFFIELD, J AF SHEFFIELD, J TI MAGNETIC FUSION COMMERCIAL POWER-PLANTS SO JOURNAL OF FUSION ENERGY LA English DT Article DE TOROIDAL MAGNETIC SYSTEMS; SPERICAL TORUS; REVERSED-FIELD PINCH; FIELD-REVERSED CONFIGURATION; SPHEROMAK AB Toroidal magnetic systems offer the best opportunity to make a commercial fusion power plant. They have, between them, all the features needed; however, no one system yet meets the ideal requirements. The tokamak is the most advanced system, and the proposed International Thermonuclear Experimental Reactor (ITER) and Tokamak Physics Experiment (TPX) will build upon the existing program to prepare for an advanced tokamak demonstration plant. Complementary toroidal systems such as the spherical torus, stellarator, reversed-field pinch, field-reversed configuration, and spheromak offer, between them, potential advantages in each area and should be studied in a balanced fusion development program. RP SHEFFIELD, J (reprint author), OAK RIDGE NATL LAB,DIV FUS ENERGY,M-S 8070,POB 2009,OAK RIDGE,TN 37831, USA. NR 0 TC 1 Z9 1 U1 0 U2 2 PU PLENUM PUBL CORP PI NEW YORK PA 233 SPRING ST, NEW YORK, NY 10013 SN 0164-0313 J9 J FUSION ENERG JI J. Fusion Energy PD SEP PY 1994 VL 13 IS 2-3 BP 167 EP 170 DI 10.1007/BF02213954 PG 4 WC Nuclear Science & Technology SC Nuclear Science & Technology GA QP932 UT WOS:A1994QP93200021 ER PT J AU LOGAN, BG AF LOGAN, BG TI INERTIAL FUSION COMMERCIAL POWER-PLANTS SO JOURNAL OF FUSION ENERGY LA English DT Article DE HEAVY-ION ACCELERATOR; KRF LASER AB This presentation discusses the motivation for inertial fusion energy, a brief synopsis of five recently-completed inertial fusion power plant designs, some general conclusions drawn from these studies, and an example of an IFE hydrogen synfuel plant to suggest that future fusion studies consider broadening fusion use to low-emission fuels production as well as electricity. RP LOGAN, BG (reprint author), LAWRENCE LIVERMORE NATL LAB,POB 5508,L-481,LIVERMORE,CA 94550, USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU PLENUM PUBL CORP PI NEW YORK PA 233 SPRING ST, NEW YORK, NY 10013 SN 0164-0313 J9 J FUSION ENERG JI J. Fusion Energy PD SEP PY 1994 VL 13 IS 2-3 BP 171 EP 172 DI 10.1007/BF02213955 PG 2 WC Nuclear Science & Technology SC Nuclear Science & Technology GA QP932 UT WOS:A1994QP93200022 ER PT J AU SLUYTER, MM AF SLUYTER, MM TI A BRIEF-HISTORY OF THE INERTIAL CONFINEMENT FUSION ADVISORY-COMMITTEE (ICFAC) SO JOURNAL OF FUSION ENERGY LA English DT Editorial Material RP SLUYTER, MM (reprint author), US DOE,DEF PROGRAMS,OFF RES & INERTIAL FUS,WASHINGTON,DC 20585, USA. NR 0 TC 0 Z9 0 U1 1 U2 2 PU PLENUM PUBL CORP PI NEW YORK PA 233 SPRING ST, NEW YORK, NY 10013 SN 0164-0313 J9 J FUSION ENERG JI J. Fusion Energy PD SEP PY 1994 VL 13 IS 2-3 BP 177 EP 179 DI 10.1007/BF02213957 PG 3 WC Nuclear Science & Technology SC Nuclear Science & Technology GA QP932 UT WOS:A1994QP93200024 ER PT J AU BERKNER, K SIEMON, R BATCHELOR, K BLOOM, E DAVIS, J DAVIS, J DEAN, SO GARNIER, J GOLDSTON, R HAAS, G JONES, R KULCINSKI, G PIET, SJ REARDON, P SHARAFAT, S SMITH, D STRINGER, J WILSON, K WONG, C AF BERKNER, K SIEMON, R BATCHELOR, K BLOOM, E DAVIS, J DAVIS, J DEAN, SO GARNIER, J GOLDSTON, R HAAS, G JONES, R KULCINSKI, G PIET, SJ REARDON, P SHARAFAT, S SMITH, D STRINGER, J WILSON, K WONG, C TI FUSION ENERGY ADVISORY-COMMITTEE (FEAC) - PANEL-6 REPORT ON THE NEUTRON-INTERACTIVE MATERIALS (NIM) PROGRAM SO JOURNAL OF FUSION ENERGY LA English DT Editorial Material C1 LOS ALAMOS NATL LAB, LOS ALAMOS, NM USA. BROOKHAVEN NATL LAB, UPTON, NY USA. OAK RIDGE NATL LAB, OAK RIDGE, TN USA. LAWRENCE LIVERMORE NATL LAB, LIVERMORE, CA 94550 USA. MCDONNELL DOUGLAS AEROSP, ST LOUIS, MO USA. FUS POWER ASSOCIATES, GAITHERSBURG, MD USA. PRINCETON UNIV, PRINCETON, NJ USA. US DOE, WASHINGTON, DC USA. PACIFIC NW LAB, RICHLAND, WA USA. UNIV WISCONSIN, MADISON, WI 53706 USA. IDAHO NATL ENGN LAB, IDAHO FALLS, ID USA. SUPERCONDUCTING SUPER COLLIDER LAB, DALLAS, TX USA. ARGONNE NATL LAB, ARGONNE, IL USA. ELECT POWER RES INST, PALO ALTO, CA 94303 USA. SANDIA NATL LABS, ALBUQUERQUE, NM USA. GEN ATOM CO, SAN DIEGO, CA 92138 USA. UNIV CALIF LOS ANGELES, LOS ANGELES, CA USA. UNIV CALIF BERKELEY, LAWRENCE BERKELEY LAB, BERKELEY, CA 94720 USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU PLENUM PUBL CORP PI NEW YORK PA 233 SPRING ST, NEW YORK, NY 10013 SN 0164-0313 J9 J FUSION ENERG JI J. Fusion Energy PD SEP PY 1994 VL 13 IS 2-3 BP 185 EP 231 PG 47 WC Nuclear Science & Technology SC Nuclear Science & Technology GA QP932 UT WOS:A1994QP93200026 ER PT J AU CONN, RW DAVIDSON, R RIPIN, B ABDOU, M BALDWIN, DE COMMISSO, R DEAN, SO HERRMANNSFELDT, W LEE, E LINDL, J MCCRORY, R MEIER, W MOSES, G NAJMABADI, F OLSON, C PAUL, P ROMESSER, T SCHRIBER, S SHEFFIELD, J AF CONN, RW DAVIDSON, R RIPIN, B ABDOU, M BALDWIN, DE COMMISSO, R DEAN, SO HERRMANNSFELDT, W LEE, E LINDL, J MCCRORY, R MEIER, W MOSES, G NAJMABADI, F OLSON, C PAUL, P ROMESSER, T SCHRIBER, S SHEFFIELD, J TI FUSION ENERGY ADVISORY-COMMITTEE (FEAC) - PANEL-7 REPORT ON INERTIAL FUSION ENERGY SO JOURNAL OF FUSION ENERGY LA English DT Editorial Material RP CONN, RW (reprint author), PRINCETON UNIV,PLASMA PHYS LAB,POB 451,PRINCETON,NJ 08543, USA. NR 0 TC 0 Z9 0 U1 2 U2 2 PU PLENUM PUBL CORP PI NEW YORK PA 233 SPRING ST, NEW YORK, NY 10013 SN 0164-0313 J9 J FUSION ENERG JI J. Fusion Energy PD SEP PY 1994 VL 13 IS 2-3 BP 233 EP 260 PG 28 WC Nuclear Science & Technology SC Nuclear Science & Technology GA QP932 UT WOS:A1994QP93200027 ER PT J AU THOMSEN, MF BAME, SJ MCCOMAS, DJ MOLDWIN, MB MOORE, KR AF THOMSEN, MF BAME, SJ MCCOMAS, DJ MOLDWIN, MB MOORE, KR TI THE MAGNETOSPHERIC LOBE AT GEOSYNCHRONOUS ORBIT SO JOURNAL OF GEOPHYSICAL RESEARCH-SPACE PHYSICS LA English DT Article ID SYNCHRONOUS ORBIT; PLASMA ANALYZER; DYNAMICS AB On rare occasions, satellites at geosynchronous altitude enter the magnetospheric lobe, characterized by extremely low ion fluxes between 1 eV and 40 keV and electron fluxes above a few hundred eV. One year of plasma observations from two simultaneously operating spacecraft at synchronous orbit is surveyed for lobe encounters. A total of 34 full encounters and 56 apparent near encounters are identified, corresponding to similar to 0.06% of the total observation time. Unlike energetic particle (E>40 keV) dropouts studied earlier, there is a strong tendency for the lobe encounters to occur postmidnight, as late as 07 local time. The two spacecraft encounter the lobe with different rates and in different seasons. These occurrence properties are not simply explicable in terms of the orbital geometry in either the solar magnetic or the geocentric solar magnetospheric coordinate system. A composite coordinate system which previously organized more energetic particle dropouts is somewhat more successful in organizing the lobe encounters, suggesting that solar wind distortion of the magnetic equatorial plane away from the dipole location and toward the antisolar direction may be largely responsible for these dropouts. Our results further suggest that this distortion persists even sunward of the dawn-dusk terminator. However, a simple dawn-dusk symmetric distortion does not fully account for all the seasonal and local time asymmetries in the occurrence of the lobe encounters; thus there is probably an additional dawn-dusk asymmetry in the distorted field. The lobe encounters are strongly associated with magnetospheric activity and tend to occur in association with rare magnetosheath encounters at synchronous orbit. It thus appears that the presence of the lobe at geosynchronous orbit is the result of major, probably asymmetric modifications of the magnetospheric field geometry in times of strong disturbance. RP THOMSEN, MF (reprint author), LOS ALAMOS NATL LAB,SPACE & ATMOSPHER SCI GRP,MS D466,LOS ALAMOS,NM 87545, USA. RI Moldwin, Mark/F-8785-2011 OI Moldwin, Mark/0000-0003-0954-1770 NR 19 TC 17 Z9 17 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 SEP 1 PY 1994 VL 99 IS A9 BP 17283 EP 17293 DI 10.1029/94JA00423 PG 11 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA PF925 UT WOS:A1994PF92500010 ER PT J AU CHAN, AA XIA, MF CHEN, L AF CHAN, AA XIA, MF CHEN, L TI ANISOTROPIC ALFVEN-BALLOONING MODES IN EARTHS MAGNETOSPHERE SO JOURNAL OF GEOPHYSICAL RESEARCH-SPACE PHYSICS LA English DT Article ID RING-CURRENT; HYDROMAGNETIC-WAVES; INSTABILITY; PARTICLES; PLASMA AB We have carried out a theoretical analysis of the stability and parallel structure of coupled shear Alfven and slow magnetosonic waves in Earth's inner magnetosphere (i.e., at equatorial distances between about five and ten Earth radii) including effects of finite anisotropic plasma pressure. Multiscale perturbation analysis of the anisotropic Grad-Shafranov equation yields an approximate self-consistent magnetohydrodynamic (MHD) equilibrium. This MHD equilibrium is used in the numerical solution of a set of eigenmode equations which describe the field line eigenfrequency, linear stability, and parallel eigenmode structure. We call these modes anisotropic Alfven-ballooning modes. The main results are: (1) The field line eigenfrequency can be significantly lowered by finite pressure effects. (2) The parallel mode structure of the transverse wave components is fairly insensitive to changes in the plasma pressure, but the compressional magnetic component can become highly peaked near the magnetic equator as a result of increased pressure, especially when P-perpendicular to > P-parallel to (here P-perpendicular to and P-parallel to are the perpendicular and parallel plasma pressure). (3) For the isotropic (P-parallel to = P-perpendicular to = P) case ballooning instability can occur when the ratio of the plasma pressure to the magnetic pressure, beta = P/(B-2/8 pi), exceeds a critical value beta(0)(B) approximate to 3.5 at the equator. (4) Compared to the isotropic case the critical beta value is lowered by anisotropy, either due to decreased field line bending stabilization when P-parallel to > P-perpendicular to or due to increased ballooning-mirror destabilization when P-perpendicular to > P-parallel to. (5) We use a beta-delta stability diagram to display the regions of instability with respect to the equatorial values of the parameters ($) over bar beta and S, where ($) over bar beta = (1/3)(beta(parallel to) + 2 beta(perpendicular to)) is an average beta value and delta = 1 - P-parallel to/P-perpendicular to is a measure of the plasma anisotropy. The diagram is divided into regions corresponding to the firehose, mirror and ballooning instabilities. It appears that observed values of the plasma pressure are below the critical value for the isotropic ballooning instability but it may be possible to approach a ballooning-mirror instability when P-perpendicular to /P-parallel to greater than or similar to 2. C1 DARTMOUTH COLL,DEPT PHYS & ASTRON,HANOVER,NH 03755. BEIJING UNIV,DEPT PHYS,BEIJING 100871,PEOPLES R CHINA. PRINCETON UNIV,DEPT ASTROPHYS SCI,PRINCETON,NJ 08544. PRINCETON UNIV,PLASMA PHYS LAB,PRINCETON,NJ. RP CHAN, AA (reprint author), RICE UNIV,DEPT SPACE PHYS & ASTRON,POB 1892,HOUSTON,TX 77251, USA. RI chen, liu/I-2297-2013 NR 31 TC 57 Z9 57 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 SEP 1 PY 1994 VL 99 IS A9 BP 17351 EP 17366 DI 10.1029/93JA03353 PG 16 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA PF925 UT WOS:A1994PF92500015 ER PT J AU FUSELIER, SA MENDE, SB GELLER, SP MILLER, M HOFFMAN, RA WYGANT, JR PONGRATZ, M MEREDITH, NP ANDERSON, RR AF FUSELIER, SA MENDE, SB GELLER, SP MILLER, M HOFFMAN, RA WYGANT, JR PONGRATZ, M MEREDITH, NP ANDERSON, RR TI DYNAMICS OF THE CRRES BARIUM RELEASES IN THE MAGNETOSPHERE SO JOURNAL OF GEOPHYSICAL RESEARCH-SPACE PHYSICS LA English DT Article AB The Combined Release and Radiation Effects satellite (CRRES) G-2, G-3, and G-4 ionized and neutral barium cloud positions are triangulated from ground-based optical data; From the time history of the ionized cloud motion perpendicular to the magnetic field, the late time coupling of the ionized cloud with the collisionless ambient plasma in the magnetosphere is investigated for each of the releases. The coupling of the ionized clouds with the ambient medium is qualitatively consistent with predictions from theory in that the coupling time increases with increasing distance from the Earth. Quantitative comparison with simple theory for the coupling time also yields reasonable agreement. Other effects not predicted by the theory are discussed in the context of the observations. C1 NASA, GODDARD SPACE FLIGHT CTR, GREENBELT, MD 20771 USA. UNIV CALIF BERKELEY, SPACE SCI LAB, BERKELEY, CA 94720 USA. LOS ALAMOS NATL LAB, LOS ALAMOS, NM 87545 USA. UCL, ATMOSPHER PHYS LAB, LONDON W1P 7PP, ENGLAND. UNIV IOWA, DEPT PHYS & ASTRON, IOWA CITY, IA 52242 USA. RP FUSELIER, SA (reprint author), LOCKHEED PALO ALTO RES LABS, DEPT 9120, BLDG 255, 3251 HANOVER ST, PALO ALTO, CA 94304 USA. NR 9 TC 3 Z9 3 U1 1 U2 1 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 0148-0227 J9 J GEOPHYS RES-SPACE JI J. Geophys. Res-Space Phys. PD SEP 1 PY 1994 VL 99 IS A9 BP 17379 EP 17389 DI 10.1029/94JA01099 PG 11 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA PF925 UT WOS:A1994PF92500017 ER PT J AU IMHOF, WL GAINES, EE MCGLENNON, JP BAKER, DN REEVES, GD BELIAN, RD AF IMHOF, WL GAINES, EE MCGLENNON, JP BAKER, DN REEVES, GD BELIAN, RD TI RELATIVISTIC ELECTRON FLUX COMPARISONS AT LOW AND HIGH-ALTITUDES WITH FAST TIME RESOLUTION AND BROAD SPATIAL COVERAGE SO JOURNAL OF GEOPHYSICAL RESEARCH-SPACE PHYSICS LA English DT Note ID ENHANCEMENTS; ATMOSPHERE AB Analyses are presented for the first high-time resolution multisatellite study of the spatial and temporal characteristics of a relativistic electron enhancement event with a rapid onset. Measurements of MeV electrons were made from two low-altitude polar orbiting satellites and three spacecraft at synchronous altitude. The electron fluxes observed by the low-altitude satellites include precipitating electrons in both the bounce and drift loss cones as well as electrons that are stably trapped, whereas the observations at geosynchronous altitude are dominated by the trapped population. The fluxes of >1 MeV electrons at low-satellite altitude over a wide range of L shells tracked very well the fluxes >0.93 MeV at synchronous altitude. C1 NASA,GODDARD SPACE FLIGHT CTR,GREENBELT,MD 20771. LOS ALAMOS NATL LAB,LOS ALAMOS,NM 87545. RP IMHOF, WL (reprint author), LOCKHEED PALO ALTO RES LABS,3251 HANOVER ST,PALO ALTO,CA 94304, USA. RI Reeves, Geoffrey/E-8101-2011 OI Reeves, Geoffrey/0000-0002-7985-8098 NR 10 TC 2 Z9 2 U1 0 U2 1 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 SEP 1 PY 1994 VL 99 IS A9 BP 17421 EP 17426 DI 10.1029/94JA01266 PG 6 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA PF925 UT WOS:A1994PF92500021 ER PT J AU PETERS, RW AF PETERS, RW TI SPECIAL ISSUE - ADSORPTION OF PRIORITY POLLUTANTS AT THE SOLID-LIQUID INTERFACE - PREFACE SO JOURNAL OF HAZARDOUS MATERIALS LA English DT Editorial Material RP PETERS, RW (reprint author), ARGONNE NATL LAB,DIV ENERGY SYST,ARGONNE,IL 60439, USA. NR 0 TC 0 Z9 0 U1 1 U2 1 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0304-3894 J9 J HAZARD MATER JI J. Hazard. Mater. PD SEP PY 1994 VL 38 IS 3 BP 351 EP 352 DI 10.1016/0304-3894(94)80040-5 PG 2 WC Engineering, Environmental; Engineering, Civil; Environmental Sciences SC Engineering; Environmental Sciences & Ecology GA PH590 UT WOS:A1994PH59000001 ER PT J AU ROWE, CL SADINSKI, WJ DUNSON, WA AF ROWE, CL SADINSKI, WJ DUNSON, WA TI PREDATION ON LARVAL AND EMBRYONIC AMPHIBIANS BY ACID-TOLERANT CADDISFLY LARVAE (PTILOSTOMIS-POSTICA) SO JOURNAL OF HERPETOLOGY LA English DT Article ID AMBYSTOMA-MACULATUM; SPOTTED SALAMANDER; TEMPORARY PONDS; LOW PH; WATER; SIZE AB We examined effects of predation by larvae of the caddisfly Ptilostomis postica on survival of embryonic and larval wood frogs (Rana sylvatica) and spotted and Jefferson salamanders (Ambystoma maculatum and A. jeffersonianum). Studies of predation were conducted both in the laboratory and natural ponds. We also estimated the tolerance to low pH of P. postica in laboratory trials. There were significant effects of predation by P. postica on overall hatching success of A. maculatum in one laboratory experiment; there was no difference between embryos from opaque versus clear egg mass morphs. Ptilostomis postica preyed on larvae of R. sylvatica and A. jeffersonianum in the laboratory and showed no preference in choice of prey. There were no differences in survival of prey due to density of amphibians or presence or absence of leaf and twig cover. Ptilostomis postica was considerably more tolerant to low pH than the amphibians. We observed no mortality of P. postica in any pH treatment (as low as pH 3.2 for 96 h). Field surveys showed that densities of P. postica were quite variable among ponds and years. Embryos of A. maculatum suffered severe (>90%) mortality due to predation by caddisflies in three ponds, whereas caddisfly predation was not observed in two ponds in which it had been observed in previous years. These results suggest that predatory outbreaks of these acid-tolerant insect larvae can dramatically affect amphibian recruitment, especially in systems already stressed by acidic conditions. C1 UNIV CALIF BERKELEY,LAWRENCE BERKELEY LAB,BERKELEY,CA 94720. RP ROWE, CL (reprint author), PENN STATE UNIV,DEPT BIOL,208 MUELLER LAB,UNIVERSITY PK,PA 16802, USA. RI Rowe, Christopher/D-5271-2012 NR 28 TC 18 Z9 21 U1 1 U2 10 PU SOC STUD AMPHIBIANS REPTILES PI OXFORD PA DEPT OF ZOOLOGY MIAMI UNIV, OXFORD, OH 45056 SN 0022-1511 J9 J HERPETOL JI J. Herpetol. PD SEP PY 1994 VL 28 IS 3 BP 357 EP 364 DI 10.2307/1564535 PG 8 WC Zoology SC Zoology GA PF821 UT WOS:A1994PF82100011 ER PT J AU FISCHER, RU SCOTT, DE CONGDON, JD BUSA, SA AF FISCHER, RU SCOTT, DE CONGDON, JD BUSA, SA TI MASS DYNAMICS DURING EMBRYONIC-DEVELOPMENT AND PARENTAL INVESTMENT IN COTTONMOUTH NEONATES SO JOURNAL OF HERPETOLOGY LA English DT Article ID POSTHATCHING YOLK RESERVES; NUTRITIONAL PROVISION; AMERICAN ALLIGATORS; TURTLES; SIZE; EGGS; ENVIRONMENTS; PERFORMANCE; COMPONENTS; EVOLUTION AB Follicle and embryo development in the cottonmouth Agkistrodon piscivorus were studied in adult females collected from a cypress swamp along the Savannah River in Aiken County, South Carolina. Non-polar lipids were extracted from follicles, eggs, embryos, and neonates. Egg dry mass averaged 4.70 g and was composed of 23.6% non-polar lipids. Neonate dry mass averaged 3.35 g and was composed of 18.8% non-polar lipids. The rate of decrease in the dry mass of egg components remained fairly constant in the early stages of development and then accelerated during the last third of embryo development, a period that corresponds with the most rapid phase of embryo growth. An average of 57% of the original egg non-polar lipids remained in neonates as parental investment in care (PIC). At a temperature of 30 C, stored lipids would fuel a neonate's standard metabolic rate for approximately 22 days. RP FISCHER, RU (reprint author), SAVANNAH RIVER ECOL LAB,DRAWER E,AIKEN,SC 29802, USA. NR 30 TC 6 Z9 6 U1 0 U2 1 PU SOC STUD AMPHIBIANS REPTILES PI OXFORD PA DEPT OF ZOOLOGY MIAMI UNIV, OXFORD, OH 45056 SN 0022-1511 J9 J HERPETOL JI J. Herpetol. PD SEP PY 1994 VL 28 IS 3 BP 364 EP 369 DI 10.2307/1564536 PG 6 WC Zoology SC Zoology GA PF821 UT WOS:A1994PF82100012 ER PT J AU POLMAN, JK STONER, DL DELEZENEBRIGGS, KM AF POLMAN, JK STONER, DL DELEZENEBRIGGS, KM TI BIOCONVERSION OF COAL, LIGNIN, AND DIMETHOXYBENZYL ALCOHOL BY PENICILLIUM-CITRINUM SO JOURNAL OF INDUSTRIAL MICROBIOLOGY LA English DT Article DE PENICILLIUM CITRINUM; COAL; LIGNIN; DIMETHOXYBENZYL ALCOHOL; VERATRYL ALCOHOL ID TRAMETES-VERSICOLOR; FUNGI; DEGRADATION; SOIL AB Bioconversion of alkali-soluble coal. sulfonated lignin. and dimethoxybenzyl alcohol (DMBA) by Penicillium citrinum was investigated with respect to the effects of (1) these compounds on growth and metabolism, and (2) the organism on the chemical nature of coal and DMBA. Alkali-soluble coal caused a slight enhancement of growth and metabolism; DMBA and lignin partially inhibited growth and metabolism. Both whole cells and cell-free extracts were capable of oxidation of DMBA to dimethoxybenzaldehyde. Whole cells demonstrated the capability of modifying alkali-soluble Beulah Zap and Ugljevik lignite coals by producing compounds that were of lower and higher molecular weight than the original coal. In vivo conversion of alkali-soluble Ugljevik coal resulted in a substantial decrease in the sulfur content of the coal (52% decrease). Cell-free extracts were able to degrade alkali-soluble Ugljevik lignite coal. The results suggest a potential usefulness of this microorganism for coal bioprocessing. RP POLMAN, JK (reprint author), EG&G IDAHO INC,IDAHO NATL ENGN LAB,IND BIOTECHNOL & PROC ENGN,POB 1625,IDAHO FALLS,ID 83415, USA. NR 33 TC 12 Z9 12 U1 0 U2 3 PU STOCKTON PRESS PI BASINGSTOKE PA HOUNDMILLS, BASINGSTOKE, HAMPSHIRE, ENGLAND RG21 6XS SN 0169-4146 J9 J IND MICROBIOL JI J. Indust. Microbiol. PD SEP PY 1994 VL 13 IS 5 BP 292 EP 299 DI 10.1007/BF01569731 PG 8 WC Biotechnology & Applied Microbiology SC Biotechnology & Applied Microbiology GA PU037 UT WOS:A1994PU03700005 ER PT J AU DELOACH, LD PAYNE, SA KWAY, WL TASSANO, JB DIXIT, SN KRUPKE, WF AF DELOACH, LD PAYNE, SA KWAY, WL TASSANO, JB DIXIT, SN KRUPKE, WF TI VIBRATIONAL STRUCTURE IN THE EMISSION-SPECTRA OF YB(3+)-DOPED APATITE CRYSTALS SO JOURNAL OF LUMINESCENCE LA English DT Article ID PHONON AB We have determined the ground state energy levels of Yb3+ in crystals with the apatite structure from the low temperature emission spectra of Yb-doped crystals of calcium, strontium and barium fluorophosphates, calcium chlorophosphate and strontium fluorovandate. Analyses of the data reveal that the previously reported laser transition arises from an electronic level of Yb interacting with the local vibrational modes of the Yb-O bond. RP DELOACH, LD (reprint author), LAWRENCE LIVERMORE NATL LAB,LAWRENCE LIVERMORE NATL LAB,POB 5508,L-493,LIVERMORE,CA 94551, USA. NR 25 TC 78 Z9 80 U1 4 U2 11 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0022-2313 J9 J LUMIN JI J. Lumines. PD SEP PY 1994 VL 62 IS 2 BP 85 EP 94 DI 10.1016/0022-2313(94)90013-2 PG 10 WC Optics SC Optics GA PK984 UT WOS:A1994PK98400006 ER PT J AU SUH, BJ BORSA, F TORGESON, DR AF SUH, BJ BORSA, F TORGESON, DR TI USE OF AN ALTERNATING-PHASE CPMG SEQUENCE TO AVOID SPIN-LOCKING EFFECTS IN T-2 MEASUREMENTS IN SOLIDS SO JOURNAL OF MAGNETIC RESONANCE SERIES A LA English DT Article ID NUCLEAR MAGNETIC-RESONANCE; ECHO DECAY; NMR; MOTION AB Measurements of the decay of the spin-echo amplitude using a two-pulse Hahn echo (TPHE), a Carr-Purcell-Meiboom-Gill (CPMG) sequence, and an alternating phase-CPMG (AP-CPMG) sequence are presented and discussed for three solid samples. We show that the CPMG generates spin-locking effects which can be suppressed entirely using the AP-CPMG variant. The comparison of the decay of the transverse magnetization in a TPHE and an AP-CPMG sequence allows one to separate the different T-2-type contributions of the spin-echo decay. (C) 1994 Academic Press, Inc. C1 IOWA STATE UNIV SCI & TECHNOL,DEPT PHYS & ASTRON,AMES,IA. UNIV PAVIA,DIPARTIMENTO FIS A VOLTA,I-27100 PAVIA,ITALY. RP SUH, BJ (reprint author), IOWA STATE UNIV SCI & TECHNOL,AMES LAB,AMES,IA 50011, USA. NR 17 TC 11 Z9 11 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 1064-1858 J9 J MAGN RESON SER A JI J. Magn. Reson. Ser. A PD SEP PY 1994 VL 110 IS 1 BP 58 EP 61 DI 10.1006/jmra.1994.1181 PG 4 WC Physics, Atomic, Molecular & Chemical SC Physics GA PH364 UT WOS:A1994PH36400010 ER PT J AU WANG, AC KENNEDY, MA REID, BR DROBNY, GP AF WANG, AC KENNEDY, MA REID, BR DROBNY, GP TI A SOLID-STATE H-2-NMR INVESTIGATION OF PURINE MOTION IN A 12-BASE-PAIR RNA DUPLEX SO JOURNAL OF MAGNETIC RESONANCE SERIES B LA English DT Article ID NUCLEAR MAGNETIC-RESONANCE; MODEL-FREE APPROACH; INTERNAL MOTION; LI-DNA; RELAXATION; MACROMOLECULES; SPECTROSCOPY; DIFFUSION; SYSTEM; CHAINS AB Solid-state H-2 NMR spectroscopy has been used to investigate the base dynamics of a RNA oligonucleotide with a defined sequence, [r(CGCGAAUUCGCG)](2), which contains the RNA analogue of the EcoRI binding site. The C8 protons of all purines in the self-complementary dodecamer were exchanged for deuterons. The quadrupole-echo lineshapes and spin-lattice relaxation times as a function of hydration for the sample in the form of the Na salt have previously been reported. In that study the H-2 NMR lineshapes and T-1 values of [r(CG*CG*A*A*UUCG*CG*)](2) were compared with those of the analogously labeled DNA sequence, [d(CG*CG*A*A*TTCG*CG*)](2) (Wang et al., J.Am. Chem. Sec. 114, 6583, 1992). It was concluded that the amplitudes of purine motion for DNA and RNA are similar at all hydration levels; however, the rate difference observed at low-hydration levels may or may not persist at high hydration. Here the internal motions of the purine bases in the RNA oligomer have been thoroughly investigated. Three models were used to simulate the motion: (1) two-site jump, (2) diffusion in a cone, and (3) restricted diffusion on the surface of a cone. The purine motion is best simulated by the restricted-diffusion on a cone model with an amplitude of +/-9.5 degrees and a rate between 8.0 x 10(6) rad/s at 90% RH and 8.4 X 10(8) rad/s at O% RH. This small amplitude and fast rate of purine motion for RNA are similar to previous results obtained for DNA purines. (C) 1994 Academic Press, Inc. C1 PACIFIC NW LAB, RICHLAND, WA 99352 USA. UNIV WASHINGTON, DEPT BIOCHEM, SEATTLE, WA 98195 USA. UNIV WASHINGTON, DEPT CHEM, SEATTLE, WA 98195 USA. FU NIGMS NIH HHS [GM 42896, GM08268-04] NR 32 TC 18 Z9 18 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 1064-1866 J9 J MAGN RESON SER B JI J. Magn. Reson. Ser. B PD SEP PY 1994 VL 105 IS 1 BP 1 EP 10 DI 10.1006/jmrb.1994.1092 PG 10 WC Physics, Atomic, Molecular & Chemical SC Physics GA PF937 UT WOS:A1994PF93700001 PM 7522867 ER PT J AU PEDRAZA, AJ PARK, JW MEYER, HM BRASKI, DN AF PEDRAZA, AJ PARK, JW MEYER, HM BRASKI, DN TI X-RAY PHOTOELECTRON-SPECTROSCOPY OF UV LASER-IRRADIATED SAPPHIRE AND ALUMINA SO JOURNAL OF MATERIALS RESEARCH LA English DT Article ID ELECTRONIC-STRUCTURE; CRYSTALS; ABLATION; AL2O3 AB X-ray photoelectron spectroscopy (XPS) was performed in as-received, thermally annealed, and laser-irradiated sapphire and alumina specimens in order to study the effects of the different treatments on surface chemistry and properties. Laser irradiations with a 308 nm wavelength laser were performed in air and in a reducing atmosphere consisting of a mixture of Ar and 4% of hydrogen. The atomic percentages of carbon, aluminum, and oxygen were measured in all the specimens. Particular attention was paid to the percentages of oxygen in the oxide and in a hydroxyl state. The XPS analyses clearly established that a very thin film of metallic aluminum is formed on the surface of both alumina and sapphire substrates when they are irradiated under a reducing atmosphere. However, the film is discontinuous because it is electrically insulating. Substrates irradiated in air have metallic aluminum only for fluences below 0.4 J/cm2. The valence band photoemission spectra of as-received, annealed, and laser-irradiated specimens were measured. In irradiated specimens, the width of the valence band spectra was found to decrease by approximately 10%. One possible cause of this decrease is the generation of point defects during laser irradiation. Electroless copper deposition occurs on sapphire and alumina substrates if their surface has been activated by laser irradiation. The time required for copper deposition was monitored by measuring the electrical resistivity in the irradiated area while the substrates were immersed in an electroless bath. The kinetics of deposition on laser-activated substrates and the XPS results show that the presence of metallic aluminum accelerates the deposition process. However, the presence of aluminum is not the sole reason for laser activation in alumina. Very strong metal-ceramic bonding is produced after thermal annealing of samples having preirradiated substrates. This result is explained in terms of the excess oxygen that is present at the ceramic surface after irradiation. C1 MARTIN MARIETTA ENERGY SYST INC,OAK RIDGE,TN 37831. OAK RIDGE NATL LAB,OAK RIDGE,TN 37831. RP PEDRAZA, AJ (reprint author), UNIV TENNESSEE,DEPT MAT SCI & ENGN,KNOXVILLE,TN 37996, USA. NR 14 TC 20 Z9 21 U1 1 U2 4 PU MATERIALS RESEARCH SOCIETY PI PITTSBURGH PA 9800 MC KNIGHT ROAD SUITE 327, PITTSBURGH, PA 15237 SN 0884-2914 J9 J MATER RES JI J. Mater. Res. PD SEP PY 1994 VL 9 IS 9 BP 2251 EP 2257 DI 10.1557/JMR.1994.2251 PG 7 WC Materials Science, Multidisciplinary SC Materials Science GA PD705 UT WOS:A1994PD70500008 ER PT J AU ZHANG, H CHANG, HLM GUO, J ZHANG, TJ AF ZHANG, H CHANG, HLM GUO, J ZHANG, TJ TI MICROSTRUCTURE OF EPITAXIAL VO2 THIN-FILMS DEPOSITED ON (11(2)OVER-BAR) SAPPHIRE BY MOCVD SO JOURNAL OF MATERIALS RESEARCH LA English DT Article ID CHEMICAL-VAPOR-DEPOSITION; HETEROEPITAXY; TRANSITION; TIO2 AB Epitaxial VO2 thin films grown on (112BAR0) sapphire (alpha - Al2O3) substrates by MOCVD at 600-degrees-C have been characterized by conventional electron microscopy and high resolution electron microscopy (HREM). Three different epitaxial relationships between the monoclinic VO2 films and sapphire substrates have been found at room temperature: I. (200)[010] monoclinic VO2 parallel-to (112BAR0) [0001] sapphire, II. (002) [010] monoclinic VO2 parallel-to (112BAR0) [0001] sapphire, and III. (020) [102] monoclinic VO2 parallel-to (112BAR0) [0001] sapphire. Expitaxial relationships II and III are equivalent to each other when the film possesses tetragonal structure at the deposition temperature; i.e., they can be described as (010) [100] tetragonal VO2 parallel-to (112BAR0) [0001] sapphire and (100) [010] tetragonal VO2 parallel-to (112BAR0) [0001] sapphire. HREM image shows that the initial nucleation of the film was dominated by the first orientation relationship, but the film then grew into the grains of the second and the third (equivalent to each other at the deposition temperature) epitaxial relationships. Successive 90-degrees transformation rotational twins around the a-axis are commonly observed in the monoclinic films. RP ZHANG, H (reprint author), ARGONNE NATL LAB,DIV MAT SCI,ARGONNE,IL 60439, USA. NR 23 TC 7 Z9 7 U1 0 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 SEP PY 1994 VL 9 IS 9 BP 2264 EP 2271 DI 10.1557/JMR.1994.2264 PG 8 WC Materials Science, Multidisciplinary SC Materials Science GA PD705 UT WOS:A1994PD70500010 ER PT J AU ROSSI, F ANDRE, B VANVEEN, A MIJNARENDS, PE SCHUT, H LABOHM, F DUNLOP, H DELPLANCKE, MP HUBBARD, K AF ROSSI, F ANDRE, B VANVEEN, A MIJNARENDS, PE SCHUT, H LABOHM, F DUNLOP, H DELPLANCKE, MP HUBBARD, K TI PHYSICAL-PROPERTIES OF A-C/N FILMS PRODUCED BY ION-BEAM-ASSISTED DEPOSITION SO JOURNAL OF MATERIALS RESEARCH LA English DT Article ID DIAMOND-LIKE CARBON; ENERGY LOSS SPECTROSCOPY; AMORPHOUS-CARBON; RAMAN-SCATTERING; MOLECULAR-DYNAMICS; CHEMICAL-STRUCTURE; THIN-FILMS; GRAPHITE; GROWTH AB Carbon films with up to 32 at.% of nitrogen have been prepared with ion beam assisted magnetron, using a N2+/N+ beam at energies between 50 and 300 eV. The composition and density of the films vary strongly with the deposition parameters. EELS, SXS, XPS, and IR studies show that these a-C: N films are mostly graphitic and have up to 20% sp3 bonding. Nitrogen is mostly combined with carbon in nitrile (C = N) and imine (C = N) groups. It is shown by RBS and NDP that density goes through a maximum as the average damage energy per incoming ion increases. Positron annihilation spectroscopy shows that the void concentration in the films goes through a minimum with average damage energy. These results are consistent with a densification induced by the collisions at low average damage energy values and induced graphitization at higher damage energy values. These results are similar to what is observed for Ar ion assisted deposition of a-C films. The mechanical properties of these films have been studied with a nanoindenter, and it was found that the hardness and Young's modulus go through a maximum as the average damage energy is increased. The maximum of mechanical properties corresponds to the minimum in the void concentration in the film. Tribological studies of the a-C:N show that the friction coefficient obtained against diamond under dynamic loading decreases strongly as the nitrogen composition increases, this effect being more pronounced at low loads. C1 CEREM, CTR ETUD NUCL GRENOBLE, F-38041 GRENOBLE, FRANCE. DELFT UNIV TECHNOL, IRI, 2629 JB DELFT, NETHERLANDS. PECHINEY CRV, F-38040 VOREPPE, FRANCE. UNIV LIBRE BRUXELLES, SESRV MET & ELECTROCHIM, B-1050 BRUSSELS, BELGIUM. LOS ALAMOS NATL LAB, CTR MAT SCI, LOS ALAMOS, NM 87454 USA. RP COMMISS EUROPEAN COMMUNITIES, CTR ADV COATING, POB 2, 1755 ZG PETTEN, NETHERLANDS. NR 32 TC 141 Z9 141 U1 1 U2 8 PU CAMBRIDGE UNIV PRESS PI NEW YORK PA 32 AVENUE OF THE AMERICAS, NEW YORK, NY 10013-2473 USA SN 0884-2914 EI 2044-5326 J9 J MATER RES JI J. Mater. Res. PD SEP PY 1994 VL 9 IS 9 BP 2440 EP 2449 DI 10.1557/JMR.1994.2440 PG 10 WC Materials Science, Multidisciplinary SC Materials Science GA PD705 UT WOS:A1994PD70500033 ER PT J AU BLUMENTHAL, WR GRAY, GT CLAYTOR, TN AF BLUMENTHAL, WR GRAY, GT CLAYTOR, TN TI RESPONSE OF ALUMINUM-INFILTRATED BORON-CARBIDE CERMETS TO SHOCK-WAVE LOADING SO JOURNAL OF MATERIALS SCIENCE LA English DT Article AB Shock-recovery and shock-spallation experiments were performed on two compositions of aluminium-infiltrated B4C cermets as a function of shock pressure. Sixty-five per cent volume B4C-Al cermets were recovered largely intact after shock loading up to pressures of ca. 12 GPa which permitted a critical study of the microstructural changes produced by the shock. Significantly, shock loading to between 12 and 13 GPa produced a combination of dislocation debris, stacking faults and deformation twins in a small fraction of the B4C grains. Fragmentation of shock-loaded 80% B4C-Al samples prevented meaningful microstructural investigation. Spall-strength testing also provided indirect evidence for the Hugoniot elastic limits (HEL) of these composites. Spall-strength calculations based on an elastic equation of state for 65% B4C-Al indicated that the elastic regime extended up to shock pressures of ca. 10 GPa, or approximately 65% of the HEL of polycrystalline B4C. A complete loss of spall strength was then observed at the transition to a plastic equation of state at a pressure of 12 GPa which coincided with observations of plasticity within the B4C-substructure. This study demonstrated that composites containing a highly ductile phase combined with a high compressive strength ceramic phase could support high dynamic tensile stresses by resisting the propagation of catastrophic cracks through the brittle ceramic substructure. C1 LOS ALAMOS NATL LAB,DIV DESIGN ENGN,LOS ALAMOS,NM 87545. RP BLUMENTHAL, WR (reprint author), LOS ALAMOS NATL LAB,DIV MAT SCI & TECHNOL,LOS ALAMOS,NM 87545, USA. NR 22 TC 34 Z9 35 U1 1 U2 3 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 SEP 1 PY 1994 VL 29 IS 17 BP 4567 EP 4576 DI 10.1007/BF00376280 PG 10 WC Materials Science, Multidisciplinary SC Materials Science GA PE419 UT WOS:A1994PE41900018 ER PT J AU OBRIEN, MH AF OBRIEN, MH TI FAILURE IN THICK ADHESIVE LAYERS SO JOURNAL OF MATERIALS SCIENCE LETTERS LA English DT Article ID TEMPERATURE; FRACTURE RP OBRIEN, MH (reprint author), IDAHO NATL ENGN LAB,IDAHO FALLS,ID 83415, USA. NR 8 TC 1 Z9 1 U1 0 U2 0 PU CHAPMAN HALL LTD PI LONDON PA 2-6 BOUNDARY ROW, LONDON, ENGLAND SE1 8HN SN 0261-8028 J9 J MATER SCI LETT JI J. Mater. Sci. Lett. PD SEP 1 PY 1994 VL 13 IS 17 BP 1240 EP 1242 DI 10.1007/BF00270947 PG 3 WC Materials Science, Multidisciplinary SC Materials Science GA PE420 UT WOS:A1994PE42000005 ER PT J AU BENDER, CM BOETTCHER, S MOSHE, M AF BENDER, CM BOETTCHER, S MOSHE, M TI SPHERICALLY SYMMETRICAL RANDOM-WALKS IN NONINTEGER DIMENSION SO JOURNAL OF MATHEMATICAL PHYSICS LA English DT Article ID ISING-MODELS; TRIVIALITY AB A previous article proposed a new kind of random walk on a spherically symmetric lattice in arbitrary noninteger dimension D. Such a lattice avoids the problems associated with a hypercubic lattice in noninteger dimension. This article examines the nature of spherically symmetric random walks in detail. A large-time asymptotic analysis of these random walks is performed and the results are used to determine the Hausdorff dimension of the process. Exact results are Obtained in terms of Hurwitz functions (incomplete zeta functions) for the probability of a walker going from one region of the spherical lattice to another. Finally, it is shown that the probability that the paths of K independent random walkers will intersect vanishes in the continuum limit if D > 2K/(K-1). C1 BROOKHAVEN NATL LAB,DEPT PHYS,UPTON,NY 11973. TECHNION ISRAEL INST TECHNOL,DEPT PHYS,IL-32000 HAIFA,ISRAEL. RP BENDER, CM (reprint author), WASHINGTON UNIV,DEPT PHYS,ST LOUIS,MO 63130, USA. RI Boettcher, Stefan/G-2640-2010 OI Boettcher, Stefan/0000-0003-1273-6771 NR 12 TC 16 Z9 16 U1 0 U2 0 PU AMER INST PHYSICS PI WOODBURY PA CIRCULATION FULFILLMENT DIV, 500 SUNNYSIDE BLVD, WOODBURY, NY 11797-2999 SN 0022-2488 J9 J MATH PHYS JI J. Math. Phys. PD SEP PY 1994 VL 35 IS 9 BP 4941 EP 4963 DI 10.1063/1.530824 PG 23 WC Physics, Mathematical SC Physics GA PF137 UT WOS:A1994PF13700037 ER PT J AU RITCHIE, B BOWDEN, CM AF RITCHIE, B BOWDEN, CM TI QUANTUM-CLASSICAL ELECTRODYNAMIC FIELD CORRESPONDENCE IN QUANTUM OPTICS SO JOURNAL OF MODERN OPTICS LA English DT Article ID RADIATION REACTION AB It is shown that causality is not violated in the classical electro-dynamic description of radiation reaction provided a physically appropriate form of the classical field is used. As a consequence the classical and quantum electrodynamic theories of a bound electron have a similar mathematical structure. C1 USA,MISSILE COMMAND,CTR RES DEV & ENGN,RES DIRECTORATE,REDSTONE ARSENAL,AL 35898. RP RITCHIE, B (reprint author), LAWRENCE LIVERMORE NATL LAB,POB 808,LIVERMORE,CA 94550, USA. NR 11 TC 1 Z9 1 U1 0 U2 0 PU TAYLOR & FRANCIS LTD PI LONDON PA ONE GUNDPOWDER SQUARE, LONDON, ENGLAND EC4A 3DE SN 0950-0340 J9 J MOD OPTIC JI J. Mod. Opt. PD SEP PY 1994 VL 41 IS 9 BP 1739 EP 1745 DI 10.1080/09500349414551691 PG 7 WC Optics SC Optics GA PM105 UT WOS:A1994PM10500005 ER PT J AU TRINGIDES, MC NGAI, KL AF TRINGIDES, MC NGAI, KL TI PHENOMENOLOGICAL ANALOGIES BETWEEN NONEQUILIBRIUM AND CORRELATED SYSTEMS SO JOURNAL OF NON-CRYSTALLINE SOLIDS LA English DT Article; Proceedings Paper CT 2nd International Discussion Meeting on Relaxations in Complex Systems CY JUN 28-JUL 08, 1993 CL ALICANTE, SPAIN ID MOLECULAR-DYNAMICS SIMULATION; COUPLING MODEL; KINETICS; GROWTH; DIFFUSION; POLYMER AB The time evolution of physical systems towards equilibrium and the relaxation of correlated systems shows interesting phenomenological analogies. Growth exponents are used to describe the evolution of the average domain size L similar to t(x) in non-equilibrium systems and the autocorrelation function of correlated systems, C(t) similar to e(-(t/tau)x). The energetics follow a simple relation between the collective and the microscopic activation energies E(D) = E(A)/x. Sublinear diffusive motions R(2) similar to t(1-X) ((1 - x) < 1) have also been observed in the two systems. C1 IOWA STATE UNIV SCI & TECHNOL,DEPT PHYS & ASTRON,AMES,IA 50011. USN,RES LAB,DIV ELECTR & SCI,WASHINGTON,DC 20375. RP TRINGIDES, MC (reprint author), IOWA STATE UNIV SCI & TECHNOL,AMES LAB,AMES,IA 50011, USA. NR 20 TC 5 Z9 5 U1 0 U2 0 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0022-3093 J9 J NON-CRYST SOLIDS JI J. Non-Cryst. Solids PD SEP PY 1994 VL 172 BP 412 EP 419 DI 10.1016/0022-3093(94)90466-9 PN 1 PG 8 WC Materials Science, Ceramics; Materials Science, Multidisciplinary SC Materials Science GA PJ196 UT WOS:A1994PJ19600058 ER PT J AU SCHAEFER, DW OLIVIER, BJ ASHLEY, C BEAUCAGE, G RICHTER, D FARAGO, B FRICK, B FISCHER, DA AF SCHAEFER, DW OLIVIER, BJ ASHLEY, C BEAUCAGE, G RICHTER, D FARAGO, B FRICK, B FISCHER, DA TI STRUCTURE AND TOPOLOGY OF SILICA AEROGELS DURING DENSIFICATION SO JOURNAL OF NON-CRYSTALLINE SOLIDS LA English DT Article ID SMALL-ANGLE-SCATTERING; DENSITY; SOLIDS; STATES AB A combination of scattering techniques, neutron powder diffraction, small-angle X-ray scattering (SAXS), neutron spin echo (NSE) and neutron time-of-flight. (TOF), is used to follow the structure and topology of silica aerogels during densification. NSE and TOF show that short-scale branching increases at the expense of large-scale connectivity leading to micron-size fluctuations, the existence of which is confirmed by SAXS. On shorter length scales, heat treatment leads to a transition from a spaghetti-like polymeric network to a colloidal microstructure. With increasing exposure to temperatures of the order of 1000 degrees C, the chord length of the colloidal solid phase increases exponentially with bulk density, even though the microscopic skeletal density remains at half that of amorphous silica. C1 FORSCHUNGSZENTRUM JULICH, INST FESTKORPERFORSCH, W-5170 JULICH, GERMANY. INST MAX VON LAUE PAUL LANGEVIN, F-38042 GRENOBLE, FRANCE. NATL INST STAND & TECHNOL, GAITHERSBURG, MD 20879 USA. RP SCHAEFER, DW (reprint author), SANDIA NATL LABS, POB 5800, ALBUQUERQUE, NM 87185 USA. RI Frick, Bernhard/C-2756-2011; Farago, Bela/H-4544-2012; Richter, Dieter/H-3701-2013 OI Richter, Dieter/0000-0003-0719-8470 NR 20 TC 9 Z9 9 U1 0 U2 7 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0022-3093 J9 J NON-CRYST SOLIDS JI J. Non-Cryst. Solids PD SEP PY 1994 VL 172 BP 647 EP 655 DI 10.1016/0022-3093(94)90503-7 PG 9 WC Materials Science, Ceramics; Materials Science, Multidisciplinary SC Materials Science GA PJ196 UT WOS:A1994PJ19600095 ER PT J AU BEAUCAGE, G SCHAEFER, DW AF BEAUCAGE, G SCHAEFER, DW TI STRUCTURAL STUDIES OF COMPLEX-SYSTEMS USING SMALL-ANGLE SCATTERING - A UNIFIED GUINIER POWER-LAW APPROACH SO JOURNAL OF NON-CRYSTALLINE SOLIDS LA English DT Article; Proceedings Paper CT 2nd International Discussion Meeting on Relaxations in Complex Systems CY JUN 28-JUL 08, 1993 CL ALICANTE, SPAIN ID ROUGH AB A unified analysis method for small-angle scattering data is demonstrated by surveying complex systems that display multiple size-scale structures. Using this approach the relationship between micro- and nano-structures can be ascertained. The method uses a function that is general enough to adequately describe systems ranging from particulates with fractally rough interfaces to mass fractals such as polymer coils. Additionally multiple Guinier and power-law regimes can be treated. The unified method can distinguish Guinier regimes buried between two power-law regimes. Data from particulate filled systems, low crystallinity polymers and low density polymer foams are analyzed. RP BEAUCAGE, G (reprint author), SANDIA NATL LABS,POB 5800,ALBUQUERQUE,NM 87185, USA. NR 20 TC 159 Z9 159 U1 7 U2 51 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0022-3093 J9 J NON-CRYST SOLIDS JI J. Non-Cryst. Solids PD SEP PY 1994 VL 172 BP 797 EP 805 DI 10.1016/0022-3093(94)90581-9 PN 2 PG 9 WC Materials Science, Ceramics; Materials Science, Multidisciplinary SC Materials Science GA PK610 UT WOS:A1994PK61000021 ER PT J AU GREEN, PF AF GREEN, PF TI TRANSLATIONAL DYNAMICS IN BINARY HOMOPOLYMER MIXTURES SO JOURNAL OF NON-CRYSTALLINE SOLIDS LA English DT Article ID CONCENTRATED POLYMER SYSTEMS; SELF-DIFFUSION COEFFICIENT; NUCLEAR MAGNETIC-RESONANCE; FIELD GRADIENT NMR; TEMPERATURE-DEPENDENCE; MUTUAL DIFFUSION; POLYSTYRENE MOLECULES; COPOLYMER STRUCTURES; CONSTRAINT RELEASE; CHAIN-LENGTH AB The influence of constraint release on the translational dynamics of deuteriated polystyrene (d-PS) chains of molecular weight, M, into two different binary mixtures was examined using forward recoil spectrometry. The first mixture was composed of two polystyrenes differing in molecular weight and the second was composed of polystyrene (PS) and poly(vinyl methyl ether) (PVME). The results are compared with a model developed to describe the effects of constraint release on the translational dynamics of a single chain diffusing into a melt whose behavior is characterized by chains that exhibit two different relaxation rates. A single fitting parameter, the ratio of the relaxation times of the fast to slow components, was used to describe the data. In the case of the PS/PS host, the ratio increased as the volume fraction of the slow component increased. For the PS/PVME system, a slight minimum was observed in the middle of the composition regime. Independent studies of the poly(ethylene oxide)/polymethylmethacrylate system, where relaxation times of the PEO and PMMA components were determined independently, reveal similar trends. RP SANDIA NATL LABS, POB 5800, ALBUQUERQUE, NM 87185 USA. NR 63 TC 7 Z9 7 U1 1 U2 5 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0022-3093 EI 1873-4812 J9 J NON-CRYST SOLIDS JI J. Non-Cryst. Solids PD SEP PY 1994 VL 172 BP 815 EP 822 DI 10.1016/0022-3093(94)90583-5 PN 2 PG 8 WC Materials Science, Ceramics; Materials Science, Multidisciplinary SC Materials Science GA PK610 UT WOS:A1994PK61000023 ER PT J AU MARTIN, JE ODINEK, J AF MARTIN, JE ODINEK, J TI LIGHT-SCATTERING-STUDIES OF THE ELECTRORHEOLOGICAL TRANSITION SO JOURNAL OF NON-CRYSTALLINE SOLIDS LA English DT Article; Proceedings Paper CT 2nd International Discussion Meeting on Relaxations in Complex Systems CY JUN 28-JUL 08, 1993 CL ALICANTE, SPAIN ID FLUIDS; RHEOLOGY AB Real-time, two-dimensional light scattering studies of the evolution of structure in an electrorheological fluid in the quiescent state and under shear are reported. It is found that when an electric field is applied to the quiescent fluid, particles chain along the electric field lines and cause strong light scattering lobes to appear at a finite scattering wavevector, q, orthogonal to the field lines. These lobes then brighten as they move to q = 0, indicating the existence of an unstable concentration fluctuation that signifies the segregation of chains into columns. In fact, the observed power law growth kinetics of the characteristic length, as well as the form of the structure factor, are qualitatively similar to two-dimensional spinodal decomposition in a system with a conserved order parameter. When the sample is subjected to shear, we find that the scattering pattern approaches a steady state, with lobes that are rotated in the direction of fluid vorticity. The angle of rotation is found to increase as the cube root of the shear rate, in agreement with a theoretical prediction of the steady state structure of fragmenting particle chains. RP MARTIN, JE (reprint author), SANDIA NATL LABS,DIV ADV MAT PHYS,POB 5800,ALBUQUERQUE,NM 87185, USA. NR 11 TC 3 Z9 3 U1 0 U2 2 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0022-3093 J9 J NON-CRYST SOLIDS JI J. Non-Cryst. Solids PD SEP PY 1994 VL 172 BP 1135 EP 1141 DI 10.1016/0022-3093(94)90635-1 PN 2 PG 7 WC Materials Science, Ceramics; Materials Science, Multidisciplinary SC Materials Science GA PK610 UT WOS:A1994PK61000075 ER PT J AU WILCOXON, JP MARTIN, JE ODINEK, J AF WILCOXON, JP MARTIN, JE ODINEK, J TI LIGHT-SCATTERING INVESTIGATION OF PHASE-SEPARATION IN A MICELLE SYSTEM SO JOURNAL OF NON-CRYSTALLINE SOLIDS LA English DT Article; Proceedings Paper CT 2nd International Discussion Meeting on Relaxations in Complex Systems CY JUN 28-JUL 08, 1993 CL ALICANTE, SPAIN ID SPINODAL DECOMPOSITION; CRITICAL-BEHAVIOR; EXPONENTS; MIXTURES; WATER; POINT AB A real-time, two-dimensional light scattering study is reported of the evolution of structure in a two-component non-ionic micelle system during phase separation via spinodal decomposition. The principal finding is that domain growth proceeds much slower than the cube root of time prediction for simple binary fluids. In fact, the growth kinetics can be empirically described as a stretched exponential approach to a pinned domain size. Although the kinetics are not yet understood, this anomalous behavior may be due to the ability of the spherical micelles to reorganize into more complex structures. The domain structure also shows some anomalies. Although at short times the expected structure factor for a critical quench is observed, at long times the structure factor crosses over to the off-critical form. However, in all cases the average scattered intensity is proportional to the cube of the domain size. These findings are discussed by comparison with standard theories of and experimental work on binary fluids. RP WILCOXON, JP (reprint author), SANDIA NATL LABS,DIV ADV MAT PHYS,POB 5800,ALBUQUERQUE,NM 87185, USA. NR 19 TC 3 Z9 3 U1 1 U2 2 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0022-3093 J9 J NON-CRYST SOLIDS JI J. Non-Cryst. Solids PD SEP PY 1994 VL 172 BP 1142 EP 1150 DI 10.1016/0022-3093(94)90636-X PN 2 PG 9 WC Materials Science, Ceramics; Materials Science, Multidisciplinary SC Materials Science GA PK610 UT WOS:A1994PK61000076 ER PT J AU SVARE, I BORSA, F TORGESON, DR MARTIN, SW AF SVARE, I BORSA, F TORGESON, DR MARTIN, SW TI CONNECTION BETWEEN NMR RELAXATION AND ELECTRICAL-CONDUCTIVITY FROM DISTRIBUTIONS OF ACTIVATION-ENERGIES OF IONIC MOTION IN SOME FAST-ION CONDUCTORS SO JOURNAL OF NON-CRYSTALLINE SOLIDS LA English DT Article; Proceedings Paper CT 2nd International Discussion Meeting on Relaxations in Complex Systems CY JUN 28-JUL 08, 1993 CL ALICANTE, SPAIN ID NUCLEAR-SPIN RELAXATION; SUPERIONIC GLASSES; DISORDERED SOLIDS; AC CONDUCTION AB The Li-7 nuclear magnetic resonance (NMR) spin-lattice relaxation and the electrical conductivity in the fast-ion conducting glass 0.56 Li2S + 0.44 SiS2 have been discussed in an earlier study using models of Li ionic motions with distributions of activation energies representing the disordered structure of glasses. Good fits to the observed NMR relaxation were obtained with a Gaussian distribution. It is shown how the complex conductivity and the related dielectric properties can be derived in the continuous time random walk model from the same distribution truncated at a proposed percolation limit. Local percolation and conductivity are possible at higher frequencies, so then the limit and the average correlation time must be scaled down. This model explains the differences between the time correlation functions derived from the two effects. The same model fits the conductivity and NMR data for a 0.6LiCl + 0.7Li(2)O + B2O3 glass. C1 IOWA STATE UNIV SCI & TECHNOL,AMES LAB,DEPT PHYS & ASTRON,AMES,IA 50011. UNIV TRONDHEIM,NTH,DEPT PHYS,N-7034 TRONDHEIM,NORWAY. UNIV PAVIA,DEPT PHYS,I-27100 PAVIA,ITALY. IOWA STATE UNIV SCI & TECHNOL,DEPT MAT SCI & ENGN,AMES,IA 50011. NR 14 TC 24 Z9 24 U1 0 U2 6 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0022-3093 J9 J NON-CRYST SOLIDS JI J. Non-Cryst. Solids PD SEP PY 1994 VL 172 BP 1300 EP 1305 DI 10.1016/0022-3093(94)90656-4 PN 2 PG 6 WC Materials Science, Ceramics; Materials Science, Multidisciplinary SC Materials Science GA PK610 UT WOS:A1994PK61000096 ER PT J AU GREEN, PF SIDEBOTTOM, D BROW, RK AF GREEN, PF SIDEBOTTOM, D BROW, RK TI RELAXATIONS IN MIXED-ALKALI METAPHOSPHATE GLASS SO JOURNAL OF NON-CRYSTALLINE SOLIDS LA English DT Article; Proceedings Paper CT 2nd International Discussion Meeting on Relaxations in Complex Systems CY JUN 28-JUL 08, 1993 CL ALICANTE, SPAIN ID VITREOUS IONIC CONDUCTORS; DIFFUSION; CONDUCTIVITY; TRANSITION; TRANSPORT AB A study of the materials response to time-dependent mechanical and electrical perturbations was performed on a mixed alkali, sodium and lithium, metaphosphate glass over a range of overlapping frequencies. The characteristic timescale that characterizes the mechanical relaxations, tau(mu), was observed to be two orders of magnitude slower than the characteristic response, tau(sigma), of the system to electrical perturbations. This is unlike the situation in single alkali glasses where tau(mu) and tau(sigma) are equivalent. Interestingly, it was also noted that the breadth of the distribution of relaxation times that characterize the response of the mixed mobile ion system is slightly narrower than that of the single alkali (Li) metaphosphate. A comparison of the characteristic timescales, tau(1) that describes the nuclear magnetic resonance spin-lattice relaxation time response revealed that tau(1) is comparable to tau(sigma). This is also by contrast with the single alkali case where tau(sigma) is approximately one order of magnitude faster than tau(1). However, as observed in single alkali glasses, the breadth of the distribution of relaxation times that characterize the loss processes of the mechanical response is considerably larger than that of the electrical response. RP GREEN, PF (reprint author), SANDIA NATL LABS,DEPT 1845,POB 5800,ALBUQUERQUE,NM 87185, USA. NR 36 TC 18 Z9 18 U1 0 U2 2 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0022-3093 J9 J NON-CRYST SOLIDS JI J. Non-Cryst. Solids PD SEP PY 1994 VL 172 BP 1353 EP 1362 DI 10.1016/0022-3093(94)90663-7 PN 2 PG 10 WC Materials Science, Ceramics; Materials Science, Multidisciplinary SC Materials Science GA PK610 UT WOS:A1994PK61000103 ER PT J AU GELLES, DS SERNYAEV, GA DALLEDONNE, M KAWAMURA, H AF GELLES, DS SERNYAEV, GA DALLEDONNE, M KAWAMURA, H TI RADIATION EFFECTS IN BERYLLIUM USED FOR PLASMA PROTECTION SO JOURNAL OF NUCLEAR MATERIALS LA English DT Article; Proceedings Paper CT 6th International Conference on Fusion Reactor Materials (ICFRM-6) CY SEP 27-OCT 01, 1993 CL STRESA, ITALY SP COMMISS EUROPEAN UNION, JOINT RES CTR, INST ADV MAT AB This paper reviews the literature on beryllium, emphasizing the effects of irradiation on essential properties. Swelling and embrittlement experiments as a function of irradiation temperature and dose, and as a function of neutron spectrum are described, and the results are quantified, where possible. Effects of impurity content are also reported, from which optimum composition specifications can be defined. Microstructural information has also been obtained to elucidate the processes controlling the property changes. The available information indicates that beryllium diverters can be expected to embrittle quickly and may need frequent replacement. C1 SF NIKIET, ZARECHNYI, RUSSIA. KERNFORSCHUNGSZENTRUM KARLSRUHE GMBH, W-7500 KARLSRUHE 1, GERMANY. JAPAN ATOM ENERGY RES INST, OARAI RES ESTAB, JMTR, BLANKET IRRADIAT & ANAL LAB, OARAI, IBARAKI 31113, JAPAN. RP GELLES, DS (reprint author), PACIFIC NW LAB, RICHLAND, WA 99352 USA. NR 53 TC 29 Z9 29 U1 0 U2 0 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0022-3115 J9 J NUCL MATER JI J. Nucl. Mater. PD SEP PY 1994 VL 212 BP 29 EP 38 DI 10.1016/0022-3115(94)90030-2 PN A PG 10 WC Materials Science, Multidisciplinary; Nuclear Science & Technology SC Materials Science; Nuclear Science & Technology GA PK613 UT WOS:A1994PK61300005 ER PT J AU KENIK, EA JONES, RH BELL, GEC AF KENIK, EA JONES, RH BELL, GEC TI IRRADIATION-ASSISTED STRESS-CORROSION CRACKING SO JOURNAL OF NUCLEAR MATERIALS LA English DT Article; Proceedings Paper CT 6th International Conference on Fusion Reactor Materials (ICFRM-6) CY SEP 27-OCT 01, 1993 CL STRESA, ITALY SP COMMISS EUROPEAN UNION, JOINT RES CTR, INST ADV MAT ID RADIATION-INDUCED SEGREGATION; STAINLESS-STEELS AB Irradiation-assisted stress corrosion cracking (IASCC) is a concern for both stainless steel and high nickel austenitic alloys irradiated in aqueous environments. A large experience base is available for conventional austenitic alloys from both commercial and experimental fission reactors. The current understanding of IASCC is reviewed with reference to recent experimental and theoretical results. Possible effects of fusion relevant irradiation conditions on IASCC will be discussed along with results from mixed spectrum reactor irradiations selected to approximate the fusion reactor environment. C1 PACIFIC NW LAB, RICHLAND, WA 99352 USA. MJ SCHIFF & ASSOCIATES, CLAREMONT, CA 91711 USA. RP KENIK, EA (reprint author), OAK RIDGE NATL LAB, DIV MET & CERAM, POB 2008, OAK RIDGE, TN 37831 USA. NR 30 TC 14 Z9 15 U1 0 U2 6 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0022-3115 J9 J NUCL MATER JI J. Nucl. Mater. PD SEP PY 1994 VL 212 BP 52 EP 59 DI 10.1016/0022-3115(94)90033-7 PN A PG 8 WC Materials Science, Multidisciplinary; Nuclear Science & Technology SC Materials Science; Nuclear Science & Technology GA PK613 UT WOS:A1994PK61300008 ER PT J AU DALLEDONNE, M HARRIES, DR KALININ, G MATTAS, R MORI, S AF DALLEDONNE, M HARRIES, DR KALININ, G MATTAS, R MORI, S TI MATERIAL PROBLEMS AND REQUIREMENTS RELATED TO THE DEVELOPMENT OF FUSION BLANKETS - THE DESIGNER POINT-OF-VIEW SO JOURNAL OF NUCLEAR MATERIALS LA English DT Article; Proceedings Paper CT 6th International Conference on Fusion Reactor Materials (ICFRM-6) CY SEP 27-OCT 01, 1993 CL STRESA, ITALY SP COMMISS EUROPEAN UNION, JOINT RES CTR, INST ADV MAT ID AUSTENITIC STAINLESS-STEELS; IRRADIATION; BEHAVIOR; DEMO; BERYLLIUM; CERAMICS; BREEDER; REACTOR; NET AB The structural materials considered for solid and liquid metal breeder blankets are the austenitic and martensitic steels and vanadium alloys. The principal concerns with these materials are: (a) the high-temperature-induced swelling of the austenitic steels, (b) the low temperature irradiation embrittlement of martensitic steels, and (c) the exact specification of the preferred alloy composition(s), properties during and following irradiation, and technological aspects (fabrication and welding) for the vanadium alloys. Solid breeder blankets are based on the use of lithiated ceramics such as Li2O, LiAlO2, Li4SiO4 and Li2ZrO3 and beryllium as a neutron multiplier. The main uncertainty with these materials is their behaviour under irradiation, particularly at higher burnups and fluences than have been achieved hitherto. Liquid metal blankets, utilising pure Li or the LiPb eutectic as the tritium breeding material, can be either self- or separately-cooled; separate coolants include water (with LiPb) and helium. The important materials issues with the LiPb are the development of permeation barriers to contain the tritium and, for the self-cooled option, electrical insulators to reduce the MHD pressure drop to acceptable levels. C1 ENTEK, MOSCOW 101000, RUSSIA. ARGONNE NATL LAB, ARGONNE, IL 60439 USA. JAPAN ATOM ENERGY RES INST, ITER, NAKA, IBARAKI 31101, JAPAN. RP DALLEDONNE, M (reprint author), KERNFORSCHUNGSZENTRUM KARLSRUHE GMBH, INST NEUTRONENPHYS & REAKTORTECH, POSTFACH 3640, D-76021 KARLSRUHE, GERMANY. NR 53 TC 7 Z9 7 U1 0 U2 1 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0022-3115 J9 J NUCL MATER JI J. Nucl. Mater. PD SEP PY 1994 VL 212 BP 69 EP 79 PN A PG 11 WC Materials Science, Multidisciplinary; Nuclear Science & Technology SC Materials Science; Nuclear Science & Technology GA PK613 UT WOS:A1994PK61300010 ER PT J AU HEINISCH, HL SINGH, BN DELARUBIA, TD AF HEINISCH, HL SINGH, BN DELARUBIA, TD TI CALIBRATING A MULTIMODEL APPROACH TO DEFECT PRODUCTION IN HIGH-ENERGY COLLISION CASCADES SO JOURNAL OF NUCLEAR MATERIALS LA English DT Article; Proceedings Paper CT 6th International Conference on Fusion Reactor Materials (ICFRM-6) CY SEP 27-OCT 01, 1993 CL STRESA, ITALY SP COMMISS EUROPEAN UNION, JOINT RES CTR, INST ADV MAT ID DISPLACEMENT CASCADES; COMPUTER-SIMULATION; MOLECULAR-DYNAMICS; METALS; DAMAGE AB A multi-model approach to simulating defect production processes at the atomic scale is described that incorporates molecular dynamics (MD), binary collision approximation (BCA) calculations and stochastic annealing simulations. The central hypothesis is that the simple, fast computer codes capable of simulating large numbers of high energy cascades (e.g., BCA codes) can be made to yield the correct defect configurations when their parameters are calibrated using the results of the more physically realistic MD simulations. The calibration procedure is investigated using results of MD simulations of 25 keV cascades in copper. The configurations of point defects are extracted from the MD cascade simulations at the end of the collisional phase, thus providing information similar to that obtained with a binary collision model. The MD collisional phase defect configurations are used as input to the ALSOME annealing simulation code, and values of the ALSOME quenching parameters are determined that yield the best fit to the post-quenching defect configurations of the MD simulations. C1 RISO NATL LAB, DEPT MAT, DK-4000 ROSKILDE, DENMARK. LAWRENCE LIVERMORE NATL LAB, LIVERMORE, CA 94550 USA. RP HEINISCH, HL (reprint author), PACIFIC NW LAB, POB 999, RICHLAND, WA 99352 USA. NR 7 TC 12 Z9 12 U1 0 U2 2 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0022-3115 J9 J NUCL MATER JI J. Nucl. Mater. PD SEP PY 1994 VL 212 BP 127 EP 131 DI 10.1016/0022-3115(94)90042-6 PN A PG 5 WC Materials Science, Multidisciplinary; Nuclear Science & Technology SC Materials Science; Nuclear Science & Technology GA PK613 UT WOS:A1994PK61300017 ER PT J AU ZINKLE, SJ HORSEWELL, A SINGH, BN SOMMER, WF AF ZINKLE, SJ HORSEWELL, A SINGH, BN SOMMER, WF TI DEFECT MICROSTRUCTURE IN COPPER-ALLOYS IRRADIATED WITH 750-MEV PROTONS SO JOURNAL OF NUCLEAR MATERIALS LA English DT Article; Proceedings Paper CT 6th International Conference on Fusion Reactor Materials (ICFRM-6) CY SEP 27-OCT 01, 1993 CL STRESA, ITALY SP COMMISS EUROPEAN UNION, JOINT RES CTR, INST ADV MAT ID NEUTRON-IRRADIATION; ION IRRADIATION; ACCUMULATION AB Transmission electron microscopy (TEM) disks of pure copper and solid solution copper alloys containing 5 at% of Al, Mn, or Ni were irradiated with 750 MeV protons to damage levels between 0.4 and 2 displacements per atom (dpa) at irradiation temperatures between 60 and 200 degrees C. The defect cluster density in copper was observed to be constant for irradiation temperatures below about 130 degrees C, and to decrease with increasing temperature above 150 degrees C. About 60% of the defect clusters in copper were resolvable as stacking fault tetrahedra (SFT). Cavity formation was observed for irradiation temperatures above about 150 degrees C. The dislocation loop and network densities were relatively low in all of the irradiated pure copper specimens. Contrary to expectations, the loop density and size both decreased with increasing irradiation temperature. Solute additions did not have any significant effect on the total density of small defect clusters, but they did cause a significant decrease in the fraction of defect clusters resolvable as SFT to similar to 20 to 25%. In addition, the dislocation loop density (> 5 nm diameter) was more than an order of magnitude higher in the alloys compared to pure copper. C1 RISO NATL LAB, DEPT MAT, DK-4000 ROSKILDE, DENMARK. LOS ALAMOS NATL LAB, LOS ALAMOS, NM 87545 USA. RP ZINKLE, SJ (reprint author), OAK RIDGE NATL LAB, DIV MET & CERAM, POB 2008, OAK RIDGE, TN 37831 USA. OI Zinkle, Steven/0000-0003-2890-6915; Horsewell, Andy/0000-0003-4297-2564 NR 16 TC 29 Z9 29 U1 0 U2 4 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0022-3115 J9 J NUCL MATER JI J. Nucl. Mater. PD SEP PY 1994 VL 212 BP 132 EP 138 DI 10.1016/0022-3115(94)90043-4 PN A PG 7 WC Materials Science, Multidisciplinary; Nuclear Science & Technology SC Materials Science; Nuclear Science & Technology GA PK613 UT WOS:A1994PK61300018 ER PT J AU WONG, J DELARUBIA, TD GUINAN, MW TOBIN, M PERLADO, JM PEREZ, AS SANZ, J AF WONG, J DELARUBIA, TD GUINAN, MW TOBIN, M PERLADO, JM PEREZ, AS SANZ, J TI THE THRESHOLD ENERGY FOR DEFECT PRODUCTION IN SIC - A MOLECULAR-DYNAMICS STUDY SO JOURNAL OF NUCLEAR MATERIALS LA English DT Article ID NEUTRON-IRRADIATION; COMPOSITE-MATERIALS; REACTORS; SURFACES; SILICON AB We discuss the results of molecular dynamics computer simulation studies of the threshold energy for defect production in beta-SiC. The simulations are performed with the Tersoff potential for SiC which provides accurate values of many of its defect properties. In addition, we show that it properly describes the melting behavior of SiC. Simulations were carried out for Si and C recoils in three-dimensional cubic computational cells with periodic boundary conditions and up to 4096 atoms. The results show anisotropy in the threshold for Si and C recoils as well as for the recoil direction. The lowest threshold is 25 eV for C recoils along [111] and the highest is 85 eV for Si recoils along [110]. Details of the defect configurations obtained will be discussed. C1 UNIV POLITECN MADRID, INST FUS NUCL, E-28006 MADRID, SPAIN. RP WONG, J (reprint author), LAWRENCE LIVERMORE NATL LAB, DEPT CHEM & MAT SCI, L-268, LIVERMORE, CA 94550 USA. NR 21 TC 28 Z9 28 U1 1 U2 4 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 SEP PY 1994 VL 212 BP 143 EP 147 DI 10.1016/0022-3115(94)90045-0 PN A PG 5 WC Materials Science, Multidisciplinary; Nuclear Science & Technology SC Materials Science; Nuclear Science & Technology GA PK613 UT WOS:A1994PK61300020 ER PT J AU FUKUSHIMA, H SHIMOMURA, Y KIRITANI, M GUINAN, MW GERSTENBERG, H MUKOUDA, I MITOMA, T AF FUKUSHIMA, H SHIMOMURA, Y KIRITANI, M GUINAN, MW GERSTENBERG, H MUKOUDA, I MITOMA, T TI DEPENDENCE OF OBSERVED CASCADE DEFECTS ON NEUTRON-SPECTRUM AND DOSE IN AU AND AG IRRADIATED WITH FISSION AND FUSION NEUTRONS AT LOW-TEMPERATURE SO JOURNAL OF NUCLEAR MATERIALS LA English DT Article; Proceedings Paper CT 6th International Conference on Fusion Reactor Materials (ICFRM-6) CY SEP 27-OCT 01, 1993 CL STRESA, ITALY SP COMMISS EUROPEAN UNION, JOINT RES CTR, INST ADV MAT ID RECOIL ENERGY; DISPLACEMENT CASCADES; MOLECULAR-DYNAMICS; FCC METALS; CU AB Cryotransfer transmission electron microscopy (TEM) experiments have been performed at about 110 K for Ag and Au irradiated with fission neutrons at 6 K and fusion neutrons at 20 K. More than 50% of the observed defect clusters were of interstitial type. The average size of defect clusters increased as neutron dose became higher. This result was explained by the effect of freely migrating interstitial atoms produced by newly developed displacement cascades. The effect of the difference in neutron spectrum was manifested in the number of defect clusters in a group of closely existing clusters ('subcascade' structure). There was a possibility that interstitial-type defect clusters were nucleated in the close vicinity of subcascades. C1 NAGOYA UNIV, SCH ENGN, DEPT NUCL ENGN, CHIKUSA KU, NAGOYA, AICHI 464, JAPAN. LAWRENCE LIVERMORE NATL LAB, LIVERMORE, CA 94550 USA. TECH UNIV MUNICH, FAC PHYS E21, D-85747 GARCHING, GERMANY. RP FUKUSHIMA, H (reprint author), HIROSHIMA UNIV, FAC ENGN, HIGASHIHIROSHIMA 724, JAPAN. NR 14 TC 4 Z9 4 U1 2 U2 3 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0022-3115 J9 J NUCL MATER JI J. Nucl. Mater. PD SEP PY 1994 VL 212 BP 154 EP 159 DI 10.1016/0022-3115(94)90047-7 PN A PG 6 WC Materials Science, Multidisciplinary; Nuclear Science & Technology SC Materials Science; Nuclear Science & Technology GA PK613 UT WOS:A1994PK61300022 ER PT J AU SPACZER, M CARO, A VICTORIA, M DELARUBIA, T AF SPACZER, M CARO, A VICTORIA, M DELARUBIA, T TI COMPUTER-SIMULATION OF DISORDERING KINETICS IN IRRADIATED A(3)B INTERMETALLIC COMPOUNDS SO JOURNAL OF NUCLEAR MATERIALS LA English DT Article; Proceedings Paper CT 6th International Conference on Fusion Reactor Materials (ICFRM-6) CY SEP 27-OCT 01, 1993 CL STRESA, ITALY SP COMMISS EUROPEAN UNION, JOINT RES CTR, INST ADV MAT ID SHORT-RANGE ORDER; CONCENTRATION FLUCTUATIONS; THRESHOLD DISPLACEMENT; MOLTEN ALLOYS; NI3AL; ENERGIES AB Molecular dynamics computer simulations of collision cascades on intermetallic Ni3Al, Cu3Au and NiAl have been performed to study the nature of the disordering processes in the cascade. The evolution of the crystalline and chemical order parameters show different time scales. To understand these features we study the liquid phase of these three alloys and present simulation results concerning the dynamical melting of small samples, examining the relaxation time and saturation value of the chemical short range order, SRO. A theoretical model for the time evolution of the SRO is given. C1 LAWRENCE LIVERMORE NATL LAB, LIVERMORE, CA 94550 USA. RP SPACZER, M (reprint author), EPFL, CRPP, DIV FUS TECHNOL, CH-5232 VILLIGEN, SWITZERLAND. NR 15 TC 6 Z9 6 U1 0 U2 1 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0022-3115 J9 J NUCL MATER JI J. Nucl. Mater. PD SEP PY 1994 VL 212 BP 164 EP 167 DI 10.1016/0022-3115(94)90049-3 PN A PG 4 WC Materials Science, Multidisciplinary; Nuclear Science & Technology SC Materials Science; Nuclear Science & Technology GA PK613 UT WOS:A1994PK61300024 ER PT J AU KATOH, Y STOLLER, RE KOHYAMA, A AF KATOH, Y STOLLER, RE KOHYAMA, A TI RATE THEORY INVESTIGATION OF INFLUENCE OF CASCADE CLUSTER FORMATION AND SOLUTE TRAPPING ON POINT-DEFECT AGGLOMERATION AND EXTENDED DEFECT EVOLUTION SO JOURNAL OF NUCLEAR MATERIALS LA English DT Article; Proceedings Paper CT 6th International Conference on Fusion Reactor Materials (ICFRM-6) CY SEP 27-OCT 01, 1993 CL STRESA, ITALY SP COMMISS EUROPEAN UNION, JOINT RES CTR, INST ADV MAT ID MICROSTRUCTURAL EVOLUTION; IRRADIATION; ENERGY AB Using a composite model of point defect behavior and microstructural evolution, the influence of cascade vacancy cluster formation and vacancy trapping at solute atoms on the point defect fluxes, point defect clustering and extended defect development was investigated. The point defect model calculates the concentrations of isolated and trapped point defects, and of simple or complex clusters. The extended defect model consists of individual rate theory models describing the evolution of cavities, Frank loops and network dislocations. Cascade vacancy clusters were observed to become the dominant sink for point defects in the early stages of irradiation at low to intermediate temperature. Therefore, the sink strength of the vacancy clusters largely determines the point defect flux and agglomeration rates. The calculations also showed that solute traps affect the irradiated microstructure to a large extent for certain combinations of trap concentration and trapping energy. Both the trap concentration and trapping energy have a non-monotonic effect on vacancy clustering though they do not change the interstitial flux significantly. C1 OAK RIDGE NATL LAB, DIV MET & CERAM, OAK RIDGE, TN 37831 USA. RP KATOH, Y (reprint author), UNIV TOKYO, DEPT MAT SCI, BUNKYO KU, 7-3-1 HONGO, TOKYO 113, JAPAN. RI Stoller, Roger/H-4454-2011; OI Katoh, Yutai/0000-0001-9494-5862 NR 23 TC 5 Z9 5 U1 1 U2 5 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0022-3115 J9 J NUCL MATER JI J. Nucl. Mater. PD SEP PY 1994 VL 212 BP 179 EP 185 DI 10.1016/0022-3115(94)90052-3 PN A PG 7 WC Materials Science, Multidisciplinary; Nuclear Science & Technology SC Materials Science; Nuclear Science & Technology GA PK613 UT WOS:A1994PK61300027 ER PT J AU MORISHITA, K HEINISCH, HL ISHINO, S SEKIMURA, N AF MORISHITA, K HEINISCH, HL ISHINO, S SEKIMURA, N TI THE RELATIONSHIP BETWEEN COLLISIONAL PHASE DEFECT DISTRIBUTION AND CASCADE COLLAPSE EFFICIENCY SO JOURNAL OF NUCLEAR MATERIALS LA English DT Article; Proceedings Paper CT 6th International Conference on Fusion Reactor Materials (ICFRM-6) CY SEP 27-OCT 01, 1993 CL STRESA, ITALY SP COMMISS EUROPEAN UNION, JOINT RES CTR, INST ADV MAT ID ENERGETIC DISPLACEMENT CASCADES; RECOIL ENERGY; IRRADIATION; METALS AB Defect distributions after the collisional phase of cascade damage processes were calculated using the computer simulation code MARLOWE, which is based on the binary collision approximation. The densities of vacant sites were evaluated in defect-dense regions at the end of the collisional phase in simulated ion irradiations of several pure metals (Au, Ag, Cu, Ni, Fe, Mo and W). The vacancy density distributions were compared to the measured cascade collapse efficiencies obtained from low-dose ion irradiations of thin foils reported in the literature to identify the minimum or ''critical'' values of the vacancy densities during the collisional phase corresponding to cascade collapse. The critical densities are generally independent of the cascade energy in the same metal. The relationships between physical properties of the target elements and the critical densities are discussed within the framework of the cascade thermal spike model. C1 PACIFIC NW LAB, RICHLAND, WA USA. UNIV TOKYO, NUCL ENGN RES LAB, TOKAI, IBARAKI 31911, JAPAN. RP MORISHITA, K (reprint author), UNIV TOKYO, DEPT QUANTUM ENGN & SYST SCI, BUNKYO KU, 7-3-1 HONGO, TOKYO 113, JAPAN. NR 16 TC 10 Z9 10 U1 0 U2 1 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0022-3115 J9 J NUCL MATER JI J. Nucl. Mater. PD SEP PY 1994 VL 212 BP 198 EP 202 DI 10.1016/0022-3115(94)90055-8 PN A PG 5 WC Materials Science, Multidisciplinary; Nuclear Science & Technology SC Materials Science; Nuclear Science & Technology GA PK613 UT WOS:A1994PK61300030 ER PT J AU ABE, H KINOSHITA, C OKAMOTO, PR REHN, LE AF ABE, H KINOSHITA, C OKAMOTO, PR REHN, LE TI EFFECT OF CONCURRENT IRRADIATION WITH ELECTRONS ON ION-INDUCED AMORPHIZATION IN SILICON SO JOURNAL OF NUCLEAR MATERIALS LA English DT Article; Proceedings Paper CT 6th International Conference on Fusion Reactor Materials (ICFRM-6) CY SEP 27-OCT 01, 1993 CL STRESA, ITALY SP COMMISS EUROPEAN UNION, JOINT RES CTR, INST ADV MAT ID CASCADES; ACCUMULATION; DEFECTS AB The effect of concurrent irradiation with electrons on ion-induced amorphization has been investigated under irradiation with high energy ions and fast electrons in the HVEM-TANDEM Facility at Argonne National Laboratory. The simultaneous irradiation with a focused electron beam prevents or retards the ion-induced amorphization, forming a distinct interface between crystalline and amorphous regions. The position of the interface has been converted to the critical electron flux, which increases with increasing energy deposition density and flux of ions and energy of electrons. It is concluded that amorphous embryos are essentially formed through overlap of subcascades, and that the prevention of ion-induced amorphization is mainly caused by athermal migration of point defects. C1 KYUSHU UNIV 36, DEPT NUCL ENGN, FUKUOKA 812, JAPAN. ARGONNE NATL LAB, DIV MAT SCI, ARGONNE, IL 60439 USA. RI abe, hiroaki/C-1906-2009 NR 18 TC 11 Z9 11 U1 0 U2 1 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0022-3115 J9 J NUCL MATER JI J. Nucl. Mater. PD SEP PY 1994 VL 212 BP 298 EP 302 PN A PG 5 WC Materials Science, Multidisciplinary; Nuclear Science & Technology SC Materials Science; Nuclear Science & Technology GA PK613 UT WOS:A1994PK61300050 ER PT J AU HAMILTON, ML GARNER, FA EDWARDS, DJ AF HAMILTON, ML GARNER, FA EDWARDS, DJ TI INFLUENCE OF HELIUM GENERATION RATE AND TEMPERATURE HISTORY ON MECHANICAL-PROPERTIES OF MODEL FE-CR-NI ALLOYS IRRADIATED IN FFTF AT RELATIVELY LOW DISPLACEMENT RATES SO JOURNAL OF NUCLEAR MATERIALS LA English DT Article; Proceedings Paper CT 6th International Conference on Fusion Reactor Materials (ICFRM-6) CY SEP 27-OCT 01, 1993 CL STRESA, ITALY SP COMMISS EUROPEAN UNION, JOINT RES CTR, INST ADV MAT ID DPA RATIO; NI-59; MICROSTRUCTURE; VARIABLES AB In agreement with earlier studies conducted at higher displacement rates, the evolution of mechanical properties at room temperature of model Fe-Cr-Ni alloys irradiated at lower displacement rates in the Ni-59 isotopic doping experiment does not appear to be strongly affected by large differences in helium generation rate. This insensitivity to helium/dpa ratio is exhibited during both isothermal and non-isothermal irradiation. The overall behavior of the model alloys used in this study is dominated by the tendency to converge to a saturation strength level that is independent of thermomechanical starting state and helium/dpa ratio, but which is dependent on irradiation temperature and alloy composition. RP HAMILTON, ML (reprint author), PACIFIC NW LAB, POB 999, RICHLAND, WA 99352 USA. NR 15 TC 4 Z9 4 U1 0 U2 0 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0022-3115 J9 J NUCL MATER JI J. Nucl. Mater. PD SEP PY 1994 VL 212 BP 325 EP 329 DI 10.1016/0022-3115(94)90080-9 PN A PG 5 WC Materials Science, Multidisciplinary; Nuclear Science & Technology SC Materials Science; Nuclear Science & Technology GA PK613 UT WOS:A1994PK61300055 ER PT J AU SHIMOMURA, Y MUKOUDA, I KIRITANI, M KOJIMA, S GARNER, FA AF SHIMOMURA, Y MUKOUDA, I KIRITANI, M KOJIMA, S GARNER, FA TI EXPERIMENTS TO EXAMINE THE CONTRIBUTION OF GAS ATOMS TO VOID FORMATION IN IRRADIATED METALS SO JOURNAL OF NUCLEAR MATERIALS LA English DT Article; Proceedings Paper CT 6th International Conference on Fusion Reactor Materials (ICFRM-6) CY SEP 27-OCT 01, 1993 CL STRESA, ITALY SP COMMISS EUROPEAN UNION, JOINT RES CTR, INST ADV MAT AB The use of vacuum melting has been employed to demonstrate that residual gases, especially hydrogen, strongly influence void nucleation of copper, copper binary alloys and various Fe-Cr-Ni base alloys during either neutron or electron irradiation. Void nucleation in nickel appears not to be strongly affected by residual gases, however. Solute-free and solute-bearing Fe-Cr-Ni alloys appear to respond differently to differences in gas content. When contamination of specimens with sodium occurs during neutron irradiation, void nucleation in both as-fabricated and vacuum-melted specimens is similar, suggesting that gas atoms re-enter the specimens during irradiation. C1 NAGOYA UNIV, SCH ENGN, DEPT NUCL ENGN, CHIKUSA KU, NAGOYA, AICHI 464, JAPAN. PACIFIC NW LAB, DEPT MAT SCI, RICHLAND, WA 99352 USA. RP SHIMOMURA, Y (reprint author), HIROSHIMA UNIV, FAC ENGN, HIGASHIHIROSHIMA 724, JAPAN. NR 4 TC 10 Z9 11 U1 0 U2 2 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0022-3115 J9 J NUCL MATER JI J. Nucl. Mater. PD SEP PY 1994 VL 212 BP 352 EP 357 DI 10.1016/0022-3115(94)90085-X PN A PG 6 WC Materials Science, Multidisciplinary; Nuclear Science & Technology SC Materials Science; Nuclear Science & Technology GA PK613 UT WOS:A1994PK61300060 ER PT J AU WATANABE, H GARNER, FA AF WATANABE, H GARNER, FA TI VOID SWELLING OF PURE COPPER, CU-5NI AND CU-5MN ALLOYS IRRADIATED WITH FAST-NEUTRONS SO JOURNAL OF NUCLEAR MATERIALS LA English DT Article; Proceedings Paper CT 6th International Conference on Fusion Reactor Materials (ICFRM-6) CY SEP 27-OCT 01, 1993 CL STRESA, ITALY SP COMMISS EUROPEAN UNION, JOINT RES CTR, INST ADV MAT AB The effects of cold-work level and solute addition (nickel or manganese) on pure copper under fast neutron irradiation have been investigated. Neutron irradiation was conducted in the Fast Flux Test Facility (FFTF) at temperatures from 638 to 873 K to doses ranging from 8 to 98 dpa. In pure copper, void swelling behavior was investigated as a function of cold-work levels. At 638 and 703 K, 10% cold-work reduced swelling somewhat with little influence at higher cold-work level. In comparison with pure copper, void swelling was suppressed by 5% nickel addition at 648 K but slightly increased at 696 K. Cu-5Mn resisted swelling in both annealed and 40% cold-worked specimens for all temperatures examined. At 648 K, void formation was not detected. Only stacking fault tetrahedra were observed in this specimen. C1 PACIFIC NW LAB, RICHLAND, WA 99352 USA. RP WATANABE, H (reprint author), KYUSHU UNIV, APPL MECH RES INST, KASUGA, FUKUOKA 816, JAPAN. RI U-ID, Kyushu/C-5291-2016; Kyushu, RIAM/F-4018-2015 NR 9 TC 9 Z9 9 U1 1 U2 4 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0022-3115 J9 J NUCL MATER JI J. Nucl. Mater. PD SEP PY 1994 VL 212 BP 370 EP 374 DI 10.1016/0022-3115(94)90088-4 PN A PG 5 WC Materials Science, Multidisciplinary; Nuclear Science & Technology SC Materials Science; Nuclear Science & Technology GA PK613 UT WOS:A1994PK61300063 ER PT J AU OKADA, A KAWAGUCHI, N HAMILTON, ML HAMADA, K YOSHIIE, T ISHIDA, I HIROTA, E AF OKADA, A KAWAGUCHI, N HAMILTON, ML HAMADA, K YOSHIIE, T ISHIDA, I HIROTA, E TI MECHANICAL PROPERTY CHANGE IN NEUTRON-IRRADIATED FE-CR AND FE-MN ALLOYS, AND THEIR DEFECT STRUCTURES SO JOURNAL OF NUCLEAR MATERIALS LA English DT Article; Proceedings Paper CT 6th International Conference on Fusion Reactor Materials (ICFRM-6) CY SEP 27-OCT 01, 1993 CL STRESA, ITALY SP COMMISS EUROPEAN UNION, JOINT RES CTR, INST ADV MAT AB The mechanical property change and defect structures were investigated on Fe-Cr and Fe-Mn alloys irradiated in the JMTR and the FFTF. Dislocation loop density increases much larger with manganese levels than chromium levels in irradiation in the JMTR, while in the FFTF, dislocation density of the Fe-Cr alloys is much larger than in the Fe-Mn alloys. This reverse trend is due to the saturation in the development of dislocation loops. The Fe-0.1 and 0.4% Cr with dislocation density much lower than that of 2% Cr, and that of the Fe-0.1 and 0.4% Mn much lower than that of 2% Mn showed the increment in yield strength almost the same as that of the Fe-2% Cr and rather larger than that of the Fe-2% Mn, respectively, in the JMTR. Yield strength increase without significant variation in strain hardening exponent is observed in the Fe-0.1% Cr and Fe-0.1% Mn irradiated in the FFTF and very small voids are observed in the Fe-0.1% Mn irradiated in the JMTR. These results suggest the existence of invisible defect clusters produced by irradiation. C1 PACIFIC NW LAB, RICHLAND, WA 99352 USA. KYOTO UNIV, INST RES REACTOR, KUMATORI, OSAKA 59004, JAPAN. RP OKADA, A (reprint author), HOKKAIDO UNIV, FAC ENGN, DEPT PRECIS ENGN, SAPPORO, HOKKAIDO 060, JAPAN. NR 8 TC 8 Z9 8 U1 2 U2 11 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0022-3115 J9 J NUCL MATER JI J. Nucl. Mater. PD SEP PY 1994 VL 212 BP 382 EP 387 DI 10.1016/0022-3115(94)90090-6 PN A PG 6 WC Materials Science, Multidisciplinary; Nuclear Science & Technology SC Materials Science; Nuclear Science & Technology GA PK613 UT WOS:A1994PK61300065 ER PT J AU EDWARDS, DJ GARNER, FA GREENWOOD, LR AF EDWARDS, DJ GARNER, FA GREENWOOD, LR TI THE INFLUENCE OF TRANSMUTATION, VOID SWELLING, AND FLUX SPECTRA UNCERTAINTIES ON THE ELECTRICAL-PROPERTIES OF COPPER AND COPPER-ALLOYS SO JOURNAL OF NUCLEAR MATERIALS LA English DT Article; Proceedings Paper CT 6th International Conference on Fusion Reactor Materials (ICFRM-6) CY SEP 27-OCT 01, 1993 CL STRESA, ITALY SP COMMISS EUROPEAN UNION, JOINT RES CTR, INST ADV MAT ID DPA AB A comparison of the predicted and measured electrical conductivities of MARZ copper and two copper alloys irradiated in FFTF shows that the calculated transmutation rates agree within 15% with those required to produce the observed changes. It also appears that the contribution of transmutants and void swelling to conductivity changes are directly additive. Of the three models studied, Euken's model has been found to best describe the contribution of void swelling to conductivity loss. RP EDWARDS, DJ (reprint author), PACIFIC NW LAB, POB 999, RICHLAND, WA 99352 USA. NR 20 TC 13 Z9 13 U1 0 U2 1 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0022-3115 J9 J NUCL MATER JI J. Nucl. Mater. PD SEP PY 1994 VL 212 BP 404 EP 409 DI 10.1016/0022-3115(94)90094-9 PN A PG 6 WC Materials Science, Multidisciplinary; Nuclear Science & Technology SC Materials Science; Nuclear Science & Technology GA PK613 UT WOS:A1994PK61300069 ER PT J AU GARNER, FA GREENWOOD, LR EDWARDS, DJ AF GARNER, FA GREENWOOD, LR EDWARDS, DJ TI THE INFLUENCE OF STARTING STATE ON NEUTRON-INDUCED DENSITY CHANGES OBSERVED IN NB-1ZR AND MO-41RE AT HIGH EXPOSURES SO JOURNAL OF NUCLEAR MATERIALS LA English DT Article; Proceedings Paper CT 6th International Conference on Fusion Reactor Materials (ICFRM-6) CY SEP 27-OCT 01, 1993 CL STRESA, ITALY SP COMMISS EUROPEAN UNION, JOINT RES CTR, INST ADV MAT ID MOLYBDENUM RHENIUM ALLOYS; IRRADIATION AB Both Nb-1Zr and Mo-41Re were irradiated in FFTF at five temperatures between 420 and 730 degrees C, reaching maximum exposure levels of 58 to 111 dpa, depending on the irradiation temperature. Each alloy was irradiated in two starting conditions, cold-worked and aged or annealed and aged. The neutron-induced swelling behavior in response to starting condition was quite different for the two alloys and appeared to reflect a strong role of precipitation in each. While transmutation does not play a major role in the response of Nb-1Zr, it plays a significant role in the behavior of Mo-41Re, which becomes a heavily-precipitated Mo-Re-Os-Tc-Ru alloy. This strong response may preclude the use of Mo-Re alloys for fusion application. RP GARNER, FA (reprint author), PACIFIC NW LAB, POB 999, RICHLAND, WA 99352 USA. RI Greenwood, Lawrence/H-9539-2016 OI Greenwood, Lawrence/0000-0001-6563-0650 NR 10 TC 13 Z9 13 U1 0 U2 2 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0022-3115 J9 J NUCL MATER JI J. Nucl. Mater. PD SEP PY 1994 VL 212 BP 426 EP 430 DI 10.1016/0022-3115(94)90098-1 PN A PG 5 WC Materials Science, Multidisciplinary; Nuclear Science & Technology SC Materials Science; Nuclear Science & Technology GA PK613 UT WOS:A1994PK61300073 ER PT J AU KLUEH, RL KENIK, EA AF KLUEH, RL KENIK, EA TI THERMAL-STABILITY OF MANGANESE-STABILIZED STAINLESS-STEELS SO JOURNAL OF NUCLEAR MATERIALS LA English DT Article; Proceedings Paper CT 6th International Conference on Fusion Reactor Materials (ICFRM-6) CY SEP 27-OCT 01, 1993 CL STRESA, ITALY SP COMMISS EUROPEAN UNION, JOINT RES CTR, INST ADV MAT ID AUSTENITIC STEELS; BEHAVIOR AB Previous work on experimental high-manganese reduced-activation austenitic stainless steels demonstrated that they had improved tensile properties relative to type 316 stainless steel (316 SS) in both the annealed and 20% cold-worked conditions. Seven steels were tested, which included an Fe-20Mn-12Cr-0.25C (in wt%) base composition, and this composition with various combinations of Ti, W, V, P, and B. Tensile tests have now been completed on these steels after thermal aging to 5000 h at 600 degrees C. Thermal stability varied with composition, but the alloys were as stable or more stable than 316 SS. After aging to 5000 h at 600 degrees C, the strength of the annealed steels increased slightly, and the strength of the cold-worked steels decreased. In both conditions, a steel with a combination of all the alloying elements had the best strength after thermal aging. Despite having higher strength than 316 SS after aging, the ductility of the strongest alloy was still as good as that of 316 SS. RP KLUEH, RL (reprint author), OAK RIDGE NATL LAB, DIV MET & CERAM, POB 2008, OAK RIDGE, TN 37831 USA. NR 11 TC 6 Z9 6 U1 0 U2 2 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0022-3115 J9 J NUCL MATER JI J. Nucl. Mater. PD SEP PY 1994 VL 212 BP 437 EP 441 DI 10.1016/0022-3115(94)90100-7 PN A PG 5 WC Materials Science, Multidisciplinary; Nuclear Science & Technology SC Materials Science; Nuclear Science & Technology GA PK613 UT WOS:A1994PK61300075 ER PT J AU PAWEL, JE ALEXANDER, DJ GROSSBECK, ML LONGEST, AW ROWCLIFFE, AF LUCAS, GE JITSUKAWA, S HISHINUMA, A SHIBA, K AF PAWEL, JE ALEXANDER, DJ GROSSBECK, ML LONGEST, AW ROWCLIFFE, AF LUCAS, GE JITSUKAWA, S HISHINUMA, A SHIBA, K TI FRACTURE-TOUGHNESS OF CANDIDATE MATERIALS FOR ITER FIRST WALL, BLANKET, AND SHIELD STRUCTURES SO JOURNAL OF NUCLEAR MATERIALS LA English DT Article; Proceedings Paper CT 6th International Conference on Fusion Reactor Materials (ICFRM-6) CY SEP 27-OCT 01, 1993 CL STRESA, ITALY SP COMMISS EUROPEAN UNION, JOINT RES CTR, INST ADV MAT ID AUSTENITIC STAINLESS-STEELS; IRRADIATION; BEHAVIOR; TENSILE AB Although the design of the International Thermonuclear Experimental Reactor is still in an evolutionary phase, the most probable choice for a structural material is a 300 series austenitic stainless steel. An experiment was carried out in the High Flux Isotope Reactor to quantify the effects of neutron irradiation on the fracture toughness properties of a range of austenitic stainless steels. The alloys investigated were provided by programs in the European Community, United States, and Japan; they included 316, 316L, and titanium-stabilized steels in cold-worked, annealed, and welded conditions. Subsize disk compact tension specimens were irradiated to a dose of about 3 dpa and 50 appm helium (the expected fusion value) at temperatures of either 60 to 125 degrees C or 200 to 300 degrees C. With the exception of a cold-worked air-melted heat of 316, all materials retained excellent fracture toughness, with K-J values varying from 150 to 400 MPa root m over the test temperature range from 90 to 250 degrees C. C1 OAK RIDGE NATL LAB, DIV ENGN TECHNOL, OAK RIDGE, TN 37831 USA. UNIV CALIF SANTA BARBARA, SANTA BARBARA, CA 93106 USA. JAPAN ATOM ENERGY RES INST, TOKAI, IBARAKI 31911, JAPAN. RP PAWEL, JE (reprint author), OAK RIDGE NATL LAB, DIV MET & CERAM, POB 2008, OAK RIDGE, TN 37831 USA. NR 13 TC 14 Z9 14 U1 2 U2 5 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0022-3115 J9 J NUCL MATER JI J. Nucl. Mater. PD SEP PY 1994 VL 212 BP 442 EP 447 DI 10.1016/0022-3115(94)90101-5 PN A PG 6 WC Materials Science, Multidisciplinary; Nuclear Science & Technology SC Materials Science; Nuclear Science & Technology GA PK613 UT WOS:A1994PK61300076 ER PT J AU GREENWOOD, LR GARNER, FA OLIVER, BM AF GREENWOOD, LR GARNER, FA OLIVER, BM TI AN ASSESSMENT OF THE NI-59 ISOTOPIC TAILORING TECHNIQUE TO STUDY THE INFLUENCE OF HELIUM/DPA RATIO SO JOURNAL OF NUCLEAR MATERIALS LA English DT Article; Proceedings Paper CT 6th International Conference on Fusion Reactor Materials (ICFRM-6) CY SEP 27-OCT 01, 1993 CL STRESA, ITALY SP COMMISS EUROPEAN UNION, JOINT RES CTR, INST ADV MAT ID NI-CR ALLOYS; DPA RATIO; VARIABLES AB The Ni-59 isotopic tailoring experiment conducted in the Fast Flux Test Facility (FFTF) to study the effects of helium on the radiation-induced evolution of microstructure and mechanical properties of austenitic steels has been assessed. The experiment has been judged to be very successful in reaching its objectives, and guidelines are presented to aid in planning similar experiments. Conducting such experiments successfully requires etching the surface regions of specimens before measuring the helium. Attempts to calculate in advance the helium/dpa ratio resulted in 20 to 40% underestimates of the measured levels. These underestimates appear to arise from uncertainties in the near-edge and out-of-core regions of both the neutron flux spectra and the neutron cross sections for Ni-59 in the epithermal energy region. C1 ROCKWELL INT CORP, CANOGA PK, CA USA. RP GREENWOOD, LR (reprint author), PACIFIC NW LAB, POB 999, RICHLAND, WA 99352 USA. RI Greenwood, Lawrence/H-9539-2016 OI Greenwood, Lawrence/0000-0001-6563-0650 NR 16 TC 10 Z9 10 U1 0 U2 0 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0022-3115 J9 J NUCL MATER JI J. Nucl. Mater. PD SEP PY 1994 VL 212 BP 492 EP 497 DI 10.1016/0022-3115(94)90110-4 PN A PG 6 WC Materials Science, Multidisciplinary; Nuclear Science & Technology SC Materials Science; Nuclear Science & Technology GA PK613 UT WOS:A1994PK61300085 ER PT J AU KAWANISHI, H GARNER, FA AF KAWANISHI, H GARNER, FA TI THE RESPONSE OF HELIUM ON MICROSTRUCTURE AND HARDNESS IN FE-NI-CR ALLOYS IRRADIATED AT 465-DEGREES-C TO 0.42-DPA USING ISOTOPIC DOPING WITH NI-59 SO JOURNAL OF NUCLEAR MATERIALS LA English DT Article; Proceedings Paper CT 6th International Conference on Fusion Reactor Materials (ICFRM-6) CY SEP 27-OCT 01, 1993 CL STRESA, ITALY SP COMMISS EUROPEAN UNION, JOINT RES CTR, INST ADV MAT ID VARIABLES AB TEM observations and hardness measurements were conducted on model Fe-25Ni-15Cr alloy irradiated in the Fast Flux Test Facility at 465 degrees C to 0.42 dpa. Half of the alloys in both solution-annealed and cold-worked conditions were doped with isotope Ni-59 to enhance the production rate of helium. Data showed that the production of dot clusters was suppressed at high He/dpa ratio (62 appm/dpa). The cluster density was increased with dose for cold-worked alloys, while it was decreased in solution-annealed alloys. Hardness in solution-annealed alloys was mainly correlated to the density and size of the clusters, whereas hardness in cold-worked alloys was understood as a competitive process of softening by dislocation annihilation and hardening by cluster formation during irradiation. C1 PACIFIC NW LAB, RICHLAND, WA 99352 USA. RP KAWANISHI, H (reprint author), UNIV TOKYO, FAC ENGN, BUNKYO KU, 7-3-1 HONGO, TOKYO 113, JAPAN. NR 11 TC 1 Z9 1 U1 0 U2 1 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0022-3115 J9 J NUCL MATER JI J. Nucl. Mater. PD SEP PY 1994 VL 212 BP 498 EP 502 DI 10.1016/0022-3115(94)90111-2 PN A PG 5 WC Materials Science, Multidisciplinary; Nuclear Science & Technology SC Materials Science; Nuclear Science & Technology GA PK613 UT WOS:A1994PK61300086 ER PT J AU TOLOCZKO, MB GARNER, FA AF TOLOCZKO, MB GARNER, FA TI RELATIONSHIP BETWEEN SWELLING AND IRRADIATION CREEP IN COLD-WORKED PCA STAINLESS-STEEL IRRADIATED TO SIMILAR-TO-178 DPA AT SIMILAR-TO-400-DEGREES-C SO JOURNAL OF NUCLEAR MATERIALS LA English DT Article; Proceedings Paper CT 6th International Conference on Fusion Reactor Materials (ICFRM-6) CY SEP 27-OCT 01, 1993 CL STRESA, ITALY SP COMMISS EUROPEAN UNION, JOINT RES CTR, INST ADV MAT ID HIGH NEUTRON FLUENCE; EXPOSURES AB The eighth and final irradiation segment for pressurized tubes constructed from the fusion Prime Candidate Alloy (PCA) has been completed in FFTF. At 178 dpa and similar to 400 degrees C, the irradiation creep of 20% cold-worked PCA has become dominated by the ''creep disappearance'' phenomenon. The total diametral deformation rate has reached the limiting value of 0.33%/dpa at the three highest stress levels employed in this test. The stress-enhancement of swelling tends to camouflage the onset of creep disappearance, however, requiring the use of several non-traditional techniques to extract the creep coefficients. No failures occurred in these tubes, even though the swelling ranged from similar to 20 to 40%. C1 PACIFIC NW LAB, RICHLAND, WA 99352 USA. RP TOLOCZKO, MB (reprint author), UNIV CALIF SANTA BARBARA, DEPT CHEM & NUCL ENGN, SANTA BARBARA, CA 93106 USA. NR 18 TC 19 Z9 19 U1 0 U2 4 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0022-3115 J9 J NUCL MATER JI J. Nucl. Mater. PD SEP PY 1994 VL 212 BP 509 EP 513 DI 10.1016/0022-3115(94)90113-9 PN A PG 5 WC Materials Science, Multidisciplinary; Nuclear Science & Technology SC Materials Science; Nuclear Science & Technology GA PK613 UT WOS:A1994PK61300088 ER PT J AU KURISHITA, H MUROGA, T WATANABE, H YOSHIDA, N KAYANO, H HAMILTON, ML AF KURISHITA, H MUROGA, T WATANABE, H YOSHIDA, N KAYANO, H HAMILTON, ML TI EFFECT OF FFTF IRRADIATION ON TENSILE PROPERTIES OF P-MODIFIED AND TI-MODIFIED MODEL AUSTENITIC ALLOYS WITH SMALL AMOUNTS OF BORON SO JOURNAL OF NUCLEAR MATERIALS LA English DT Article; Proceedings Paper CT 6th International Conference on Fusion Reactor Materials (ICFRM-6) CY SEP 27-OCT 01, 1993 CL STRESA, ITALY SP COMMISS EUROPEAN UNION, JOINT RES CTR, INST ADV MAT ID MICROSTRUCTURAL EVOLUTION; FAST-NEUTRONS; HELIUM; NI-59; CR; PHOSPHORUS; TITANIUM; STEEL AB The interactive effects of P and Ti additions, helium/dpa ratio, irradiation and test temperature on postirradiation tensile properties of a model Fe-16Cr-17Ni alloy were investigated. Miniature tensile specimens containing 64 and 522 appm B-10 (0.75 and 3.8 He/dpa ratio), with and without 0.1 wt% P and 0.25 wt% Ti additions, were irradiated to 33 dpa at 703, 793 and 874 K in the Fast Flux Test Facility (FFTF). They were deformed at 300, 473 and 673 K. For all the alloy conditions the irradiation at 703 K increases the yield stress and decreases the uniform elongation significantly. An effect of B-10 addition occurs, which is not related to helium generation, but it is small compared to the effects of P and Ti additions. Additions of P and Ti, especially their simultaneous addition, cause a significant strengthening but no appreciable change in uniform elongation. The cause of the strengthening and the observed changes in uniform elongation are discussed. C1 KYUSHU UNIV, APPL MECH RES INST, KASUGA, FUKUOKA 816, JAPAN. PACIFIC NW LAB, RICHLAND, WA 99352 USA. RP KURISHITA, H (reprint author), TOHOKU UNIV, INST MAT RES, OARAI BRANCH, OARAI, IBARAKI 31113, JAPAN. RI U-ID, Kyushu/C-5291-2016; Kyushu, RIAM/F-4018-2015 NR 15 TC 7 Z9 7 U1 0 U2 1 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0022-3115 J9 J NUCL MATER JI J. Nucl. Mater. PD SEP PY 1994 VL 212 BP 519 EP 524 DI 10.1016/0022-3115(94)90115-5 PN A PG 6 WC Materials Science, Multidisciplinary; Nuclear Science & Technology SC Materials Science; Nuclear Science & Technology GA PK613 UT WOS:A1994PK61300090 ER PT J AU KLUEH, RL ALEXANDER, DJ AF KLUEH, RL ALEXANDER, DJ TI EFFECT OF VANADIUM AND TITANIUM ON MECHANICAL-PROPERTIES OF CHROMIUM-TUNGSTEN STEELS SO JOURNAL OF NUCLEAR MATERIALS LA English DT Article; Proceedings Paper CT 6th International Conference on Fusion Reactor Materials (ICFRM-6) CY SEP 27-OCT 01, 1993 CL STRESA, ITALY SP COMMISS EUROPEAN UNION, JOINT RES CTR, INST ADV MAT ID CR-W STEELS; BEHAVIOR AB Increasing the vanadium content from 0.1 to 0.50% in a 2.25Cr-2W-0.1C steel (all concentrations are in wt%) increased the yield stress 20% and resulted in a higher ductile-brittle transition temperature (DBTT). When vanadium was increased to 0.5%, a further slight increase in strength occurred with a large increase in DBTT. Thus, optimum strength and impact toughness is achieved at an intermediate vanadium concentration. With the addition of 0.02% Ti to 2.25Cr-0.25V-0.1C, 2.25Cr-2W-0.1C, and 2.25Cr-2W-0.25V-0.1C steels, yield stress decreased 10 to 30%. An increase in impact toughness accompanied the strength loss. The toughness may have been affected by a decrease in the prior austenite grain size. There was little difference in the DBTT of the Ti-modified steels tempered at 700 or 750 degrees C. The use of a Ti-modified steel tempered at 700 degrees C might offset the strength advantage of steels without titanium, which have to be tempered at the higher temperature. RP KLUEH, RL (reprint author), OAK RIDGE NATL LAB, DIV MET & CERAM, POB 2008, OAK RIDGE, TN 37831 USA. NR 7 TC 4 Z9 4 U1 0 U2 1 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0022-3115 J9 J NUCL MATER JI J. Nucl. Mater. PD SEP PY 1994 VL 212 BP 569 EP 573 DI 10.1016/0022-3115(94)90124-4 PN A PG 5 WC Materials Science, Multidisciplinary; Nuclear Science & Technology SC Materials Science; Nuclear Science & Technology GA PK613 UT WOS:A1994PK61300099 ER PT J AU TOLOCZKO, MB GARNER, FA EIHOLZER, CR AF TOLOCZKO, MB GARNER, FA EIHOLZER, CR TI IRRADIATION CREEP AND SWELLING OF THE US FUSION HEATS OF HT9-1MO AND 9CR-1MO TO 208-DPA AT SIMILAR-TO-400-DEGREES-C SO JOURNAL OF NUCLEAR MATERIALS LA English DT Article; Proceedings Paper CT 6th International Conference on Fusion Reactor Materials (ICFRM-6) CY SEP 27-OCT 01, 1993 CL STRESA, ITALY SP COMMISS EUROPEAN UNION, JOINT RES CTR, INST ADV MAT AB The irradiation creep and swelling behaviors of the fusion heats of HT9 and 9Cr-1Mo at similar to 400 degrees C have been measured to exposures as large as 208 dpa, using both diametral and density measurements of helium-pressurized creep tubes. Void swelling was found in both alloys at 208 dpa to occur at rates of 0.012%/dpa or less, with the swelling of HT9 exhibiting a larger degree of stress enhancement than 9Cr-1Mo. The creep rate of HT9 is rather nonlinear in its response to hoop stress level in the range 0-200 MPa, but 9Cr-1Mo exhibits only slightly greater than linear behavior with stress level. The creep compliance and creep-swelling coupling coefficient for 9Cr-1Mo are consistent with values obtained for other steels. C1 PACIFIC NW LAB, RICHLAND, WA 99352 USA. WESTINGHOUSE HANFORD CO, RICHLAND, WA 99352 USA. RP TOLOCZKO, MB (reprint author), UNIV CALIF SANTA BARBARA, SANTA BARBARA, CA 93106 USA. NR 5 TC 72 Z9 75 U1 1 U2 10 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0022-3115 J9 J NUCL MATER JI J. Nucl. Mater. PD SEP PY 1994 VL 212 BP 604 EP 607 DI 10.1016/0022-3115(94)90131-7 PN A PG 4 WC Materials Science, Multidisciplinary; Nuclear Science & Technology SC Materials Science; Nuclear Science & Technology GA PK613 UT WOS:A1994PK61300106 ER PT J AU GREENWOOD, LR GARNER, FA AF GREENWOOD, LR GARNER, FA TI TRANSMUTATION OF MO, RE, W, HF, AND V IN VARIOUS IRRADIATION TEST FACILITIES AND STARFIRE SO JOURNAL OF NUCLEAR MATERIALS LA English DT Article; Proceedings Paper CT 6th International Conference on Fusion Reactor Materials (ICFRM-6) CY SEP 27-OCT 01, 1993 CL STRESA, ITALY SP COMMISS EUROPEAN UNION, JOINT RES CTR, INST ADV MAT ID NEUTRON-IRRADIATION; ALLOYS AB With the exception of V and Cu alloys, the formation of solid transmutants has not been thought to play a large role in the response of metals to irradiation. For a number of refractory elements, however, it appears that very large levels of solid transmutation can occur both in fission and fusion spectra. The phase stability and other properties of alloys can be strong functions of the changing composition. The spectral sensitivity of transmutation also poses some difficulty in correlating data from various neutron spectra. Transmutation of Mo, Re, W, Hf and V have been calculated for the Fast Flux Test Facility (FFTF), the High Flux Isotope Reactor (HFIR), and the STARFIRE fusion reactor. Results show that Re and W undergo sizeable transmutation in these spectra, and may limit the use of these elements in fusion reactor materials. Vanadium and hafnium have high transmutation rates in HFIR and may require spectral tailoring. RP GREENWOOD, LR (reprint author), PACIFIC NW LAB, POB 999, RICHLAND, WA 99352 USA. RI Greenwood, Lawrence/H-9539-2016 OI Greenwood, Lawrence/0000-0001-6563-0650 NR 18 TC 60 Z9 60 U1 1 U2 11 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0022-3115 J9 J NUCL MATER JI J. Nucl. Mater. PD SEP PY 1994 VL 212 BP 635 EP 639 DI 10.1016/0022-3115(94)90136-8 PN A PG 5 WC Materials Science, Multidisciplinary; Nuclear Science & Technology SC Materials Science; Nuclear Science & Technology GA PK613 UT WOS:A1994PK61300111 ER PT J AU BUTTERWORTH, GJ MCCARTHY, KA SMOLIK, GR FORTY, CBA AF BUTTERWORTH, GJ MCCARTHY, KA SMOLIK, GR FORTY, CBA TI SAFETY AND ENVIRONMENTAL ASPECTS OF VANADIUM ALLOYS SO JOURNAL OF NUCLEAR MATERIALS LA English DT Article; Proceedings Paper CT 6th International Conference on Fusion Reactor Materials (ICFRM-6) CY SEP 27-OCT 01, 1993 CL STRESA, ITALY SP COMMISS EUROPEAN UNION, JOINT RES CTR, INST ADV MAT AB Two important safety-related and environmental aspects of vanadium alloys are considered; the early doses that could potentially be delivered at the plant site boundary in the event of an accidental release of first-wall material and the disposal and recycling options for expired first wall-blanket material. The reference alloys V-15Cr-5Ti and V-3Ti-1Si are found to lead to similar doses and these are roughly an order of magnitude below the dose from 316L steel. These alloys appear to be excellent candidates for multiple recycling via high-vacuum remelting/refining, with consequent reductions in the consumption of alloy and the quantities of waste requiring geological isolation. The doses from accidental releases are found to be independent of the number of usage cycles. C1 UKAEA EURATOM FUS ASSOC, ABINGDON OX14 3DB, OXON, ENGLAND. RP BUTTERWORTH, GJ (reprint author), EG&G IDAHO INC, IDAHO NATL ENGN LAB, POB 1625, IDAHO FALLS, ID 83415 USA. NR 9 TC 5 Z9 5 U1 0 U2 0 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0022-3115 J9 J NUCL MATER JI J. Nucl. Mater. PD SEP PY 1994 VL 212 BP 667 EP 672 DI 10.1016/0022-3115(94)90142-2 PN A PG 6 WC Materials Science, Multidisciplinary; Nuclear Science & Technology SC Materials Science; Nuclear Science & Technology GA PK613 UT WOS:A1994PK61300117 ER PT J AU GELLES, DS AF GELLES, DS TI MICROSTRUCTURAL DEVELOPMENT IN REDUCED-ACTIVATION FERRITIC ALLOYS IRRADIATED TO 200-DPA AT 420-DEGREES-C SO JOURNAL OF NUCLEAR MATERIALS LA English DT Article; Proceedings Paper CT 6th International Conference on Fusion Reactor Materials (ICFRM-6) CY SEP 27-OCT 01, 1993 CL STRESA, ITALY SP COMMISS EUROPEAN UNION, JOINT RES CTR, INST ADV MAT AB Density change and microstructural development are reported for nine reduced activation ferritic steels covering the range 2.3 to 12Cr with varying additions of V and/or W for hardening and up to 6.5 Mn for austenite stability. Specimens were examined following irradiation in FFTF/MOTA at 420 degrees C to a dose exceeding 200 dpa. Void swelling was found, but the swelling remained at 5% or below, with the worst case in an alloy of 9Cr-2Mn-1WV. The carbide structure pinning martensite lath boundaries remained in place. RP GELLES, DS (reprint author), PACIFIC NW LAB, POB 999, RICHLAND, WA 99352 USA. NR 10 TC 26 Z9 29 U1 0 U2 3 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0022-3115 J9 J NUCL MATER JI J. Nucl. Mater. PD SEP PY 1994 VL 212 BP 714 EP 719 DI 10.1016/0022-3115(94)90150-3 PN A PG 6 WC Materials Science, Multidisciplinary; Nuclear Science & Technology SC Materials Science; Nuclear Science & Technology GA PK613 UT WOS:A1994PK61300125 ER PT J AU KIMURA, A CHARLOT, LA GELLES, DS JONES, RH AF KIMURA, A CHARLOT, LA GELLES, DS JONES, RH TI DEPENDENCE OF GRAIN-BOUNDARY CHEMISTRY ON THE IRRADIATION DOSE IN LOW-ACTIVATION FERRITICS SO JOURNAL OF NUCLEAR MATERIALS LA English DT Article; Proceedings Paper CT 6th International Conference on Fusion Reactor Materials (ICFRM-6) CY SEP 27-OCT 01, 1993 CL STRESA, ITALY SP COMMISS EUROPEAN UNION, JOINT RES CTR, INST ADV MAT ID STEELS AB Grain boundary chemistries in low activation 9%Cr-2%Mn-1%W and 12%Cr-6%Mn-1%W steels were measured by means of Auger electron spectroscopy (AES) after irradiations in the FFTF/MOTA at 638 K up to doses of 10 and 25 dpa. In 12%Cr-6%Mn-1%W steel, grain boundary concentration of Si increased with an increase in the irradiation dose from 10 to 25 dpa. Segregation of Mn, however, appeared to saturate or even decreased with the increase. The average size of grain boundary precipitates was increased during the irradiation from 10 to 25 dpa. It is considered that beyond the 10 dpa irradiation, Mn-rich precipitates at grain boundaries absorb Mn atoms segregated at grain boundaries, resulting in the growth of grain boundary precipitates and the reduction of segregated Mn atoms in elemental form at grain boundaries. It is possible that Si atoms which may compete site with Mn atoms at grain boundaries begin to segregate at grain boundaries. In contrast, no significant change in grain boundary chemistry was recognized in 9%Cr-2%Mn-1%W alloy with the increase in irradiation dose from 10 to 25 dpa. C1 PACIFIC NW LAB, RICHLAND, WA 99352 USA. RP KIMURA, A (reprint author), TOHOKU UNIV, INST MAT RES, AOBA KU, 2-1-1 KATAHIRA, SENDAI, MIYAGI 980, JAPAN. NR 5 TC 5 Z9 5 U1 0 U2 0 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0022-3115 J9 J NUCL MATER JI J. Nucl. Mater. PD SEP PY 1994 VL 212 BP 725 EP 729 DI 10.1016/0022-3115(94)90152-X PN A PG 5 WC Materials Science, Multidisciplinary; Nuclear Science & Technology SC Materials Science; Nuclear Science & Technology GA PK613 UT WOS:A1994PK61300127 ER PT J AU KURISHITA, H KAYANO, H NARUI, M KIMURA, A HAMILTON, ML GELLES, DS AF KURISHITA, H KAYANO, H NARUI, M KIMURA, A HAMILTON, ML GELLES, DS TI TENSILE PROPERTIES OF REDUCED-ACTIVATION FE-9CR-2W STEELS AFTER FFTF IRRADIATION SO JOURNAL OF NUCLEAR MATERIALS LA English DT Article; Proceedings Paper CT 6th International Conference on Fusion Reactor Materials (ICFRM-6) CY SEP 27-OCT 01, 1993 CL STRESA, ITALY SP COMMISS EUROPEAN UNION, JOINT RES CTR, INST ADV MAT ID CR-2-PERCENT W STEEL; FERRITIC STEELS AB In order to develop radiation resistant steels with reduced activation for fusion reactor applications, the effect of fast neutron irradiation was investigated on the tensile properties of five types of Fe-9Cr-2W martensitic steel with and without small additions of boron, yttrium and aluminum. Miniature tensile specimens of the steels were irradiated to 28 dpa at 663 K and 33-35 dpa at 703, 793 and 873 K in the Fast Flux Test Facility (FFTF) and were deformed at temperatures between 300 and 873 K. The yield and ultimate tensile stresses were not significantly affected by the irradiations, but the total elongation was considerably decreased by the irradiation at 663 K. The reduction in elongation depended strongly on the test temperature with a maximum at around 673 K. The addition of yttrium alone tended to increase the high temperature strength, while the simultaneous addition of yttrium and aluminum tended to decrease the total elongation. C1 TOHOKU UNIV, INST MAT RES, SENDAI, MIYAGI 980, JAPAN. PACIFIC NW LAB, RICHLAND, WA 99352 USA. RP KURISHITA, H (reprint author), TOHOKU UNIV, INST MAT RES, OARAI BRANCH, OARAI, IBARAKI 31113, JAPAN. NR 17 TC 13 Z9 13 U1 0 U2 3 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0022-3115 J9 J NUCL MATER JI J. Nucl. Mater. PD SEP PY 1994 VL 212 BP 730 EP 735 DI 10.1016/0022-3115(94)90153-8 PN A PG 6 WC Materials Science, Multidisciplinary; Nuclear Science & Technology SC Materials Science; Nuclear Science & Technology GA PK613 UT WOS:A1994PK61300128 ER PT J AU KLUEH, RL ALEXANDER, DJ AF KLUEH, RL ALEXANDER, DJ TI IMPACT TOUGHNESS OF IRRADIATED REDUCED-ACTIVATION FERRITIC STEELS SO JOURNAL OF NUCLEAR MATERIALS LA English DT Article; Proceedings Paper CT 6th International Conference on Fusion Reactor Materials (ICFRM-6) CY SEP 27-OCT 01, 1993 CL STRESA, ITALY SP COMMISS EUROPEAN UNION, JOINT RES CTR, INST ADV MAT ID CR-W STEELS; BEHAVIOR AB Eight chromium-tungsten steels ranging from 2.25 to 12 wt% Cr were irradiated at 365 degrees C to 13-14 dpa in the Fast Flux Test Facility. Post irradiation Charpy impact tests showed a loss of toughness for all steels, as measured by an increase in the ductile-brittle transition temperature (DBTT) and a decrease in the upper-shelf energy. The most irradiation-resistant steels were two 9% Cr steels: the DBTT of a 9Cr-2W-0.25V-0.1C steel increased 29 degrees C, and for the same composition with an addition of 0.07% Ta the DBTT increased only 15 degrees C. This is the smallest shift ever observed for such a steel irradiated to these levels. The other steels developed shifts in DBTT of 100 to 300 degrees C. A 2.25% Cr steel with 2% W, 0.25% V, and 0.1% C was less severely affected by irradiation than 2.25% Cr steels with 0.25% V and no tungsten, 2% W and no vanadium, and with 1% W and 0.25% V. Irradiation resistance appears to be associated with microstructure, and microstructural manipulation may lead to improved properties. RP KLUEH, RL (reprint author), OAK RIDGE NATL LAB, DIV MET & CERAM, POB 2008, OAK RIDGE, TN 37831 USA. NR 11 TC 20 Z9 20 U1 0 U2 2 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0022-3115 J9 J NUCL MATER JI J. Nucl. Mater. PD SEP PY 1994 VL 212 BP 736 EP 740 DI 10.1016/0022-3115(94)90154-6 PN A PG 5 WC Materials Science, Multidisciplinary; Nuclear Science & Technology SC Materials Science; Nuclear Science & Technology GA PK613 UT WOS:A1994PK61300129 ER PT J AU LI, HX JONES, RH HIRTH, JP GELLES, DS AF LI, HX JONES, RH HIRTH, JP GELLES, DS TI EFFECT OF LOADING MODE ON THE FRACTURE-TOUGHNESS OF A REDUCED-ACTIVATION FERRITIC MARTENSITIC STAINLESS-STEEL SO JOURNAL OF NUCLEAR MATERIALS LA English DT Article ID III FRACTURE AB The critical J integrals of mode I (J(IC)), mixed-mode I/III (J(MC)), and mode III (J(IIIC)) were examined for a ferritic stainless steel (F-82H) at ambient temperature. A determination of J(MC) was made using modified compact-tension specimens. Different ratios of tension/shear stress were achieved by varying the principal axis of the crack plane between 0 and 55 degrees from the load line. The results showed that J(MC)s and tearing moduli (T-M) varied with the crack angles and were lower than their made I and mode III counterparts. Both the minimum J(MC) and T-M occurred at a crack angle between 40 and 50 degrees, where the load ratio sigma(i)/sigma(iii) was 1.2 to 0.84. The J(min) was 240 kJ/m(2), and ratios of J(IC)/J(min) and J(MC)/J(min) were about 2.1 and 1.9, respectively. The morphology of fracture surfaces was consistent with the change of J(MC) and T-M values. While the upper-shelf fracture toughness of F-82H depends on loading mode, the J(min) remains very high. Other important considerations include the effect of mixed-mode loading on the DBT temperature, and effects of hydrogen and irradiation on J(min). C1 PACIFIC NW LAB, RICHLAND, WA 99352 USA. RP LI, HX (reprint author), WASHINGTON STATE UNIV, PULLMAN, WA 99164 USA. NR 19 TC 9 Z9 9 U1 0 U2 0 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0022-3115 J9 J NUCL MATER JI J. Nucl. Mater. PD SEP PY 1994 VL 212 BP 741 EP 745 PN A PG 5 WC Materials Science, Multidisciplinary; Nuclear Science & Technology SC Materials Science; Nuclear Science & Technology GA PK613 UT WOS:A1994PK61300130 ER PT J AU ABE, F GARNER, FA KAYANO, H AF ABE, F GARNER, FA KAYANO, H TI EFFECT OF CARBON ON IRRADIATION HARDENING OF REDUCED-ACTIVATION 10CR-30MN AUSTENITIC STEELS SO JOURNAL OF NUCLEAR MATERIALS LA English DT Article; Proceedings Paper CT 6th International Conference on Fusion Reactor Materials (ICFRM-6) CY SEP 27-OCT 01, 1993 CL STRESA, ITALY SP COMMISS EUROPEAN UNION, JOINT RES CTR, INST ADV MAT ID NEUTRON-IRRADIATION; INSITU DEFORMATION; ALLOYS AB Tensile properties of reduced-activation 10Cr-30Mn austenitic steels with carbon levels from 0.003 to 0.55% were investigated over the temperature range from room temperature to 873 K after neutron irradiation in the Japan Materials Testing Reactor at 573 K to 8.5 x 10(22) n/m(2). Irradiation-induced increase in yield stress increased significantly with carbon concentration up to about 0.1% and it was constant above 0.1% carbon. A high density of dislocation loops with small (below 10 nm) and large (20-30 nm) sizes formed during irradiation. The high density, small loops caused a large irradiation hardening, while the large loops contributed only slightly to irradiation hardening. It was considered that carbon atoms formed the small loops together with irradiation defects. The deformation channeling was observed in the irradiated high carbon steels, 0.11 and 0.55% carbon, but not in the very low carbon steel, 0.003% carbon, after deformation near room temperature. C1 PACIFIC NW LAB, RICHLAND, WA 99352 USA. TOHOKU UNIV, INST MAT RES, OARAI BRANCH, OARAI, IBARAKI 31113, JAPAN. RP ABE, F (reprint author), NATL RES INST MET, TSUKUBA, IBARAKI 305, JAPAN. NR 18 TC 9 Z9 9 U1 0 U2 1 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0022-3115 J9 J NUCL MATER JI J. Nucl. Mater. PD SEP PY 1994 VL 212 BP 760 EP 765 DI 10.1016/0022-3115(94)90159-7 PN A PG 6 WC Materials Science, Multidisciplinary; Nuclear Science & Technology SC Materials Science; Nuclear Science & Technology GA PK613 UT WOS:A1994PK61300134 ER PT J AU CHUNG, HM LOOMIS, BA SMITH, DL AF CHUNG, HM LOOMIS, BA SMITH, DL TI CREEP-PROPERTIES OF VANADIUM-BASE ALLOYS SO JOURNAL OF NUCLEAR MATERIALS LA English DT Article; Proceedings Paper CT 6th International Conference on Fusion Reactor Materials (ICFRM-6) CY SEP 27-OCT 01, 1993 CL STRESA, ITALY SP COMMISS EUROPEAN UNION, JOINT RES CTR, INST ADV MAT AB Vanadium-base alloys are promising candidate materials for application in fusion reactor structural components because of several important advantages. V-4Cr-4Ti has been identified as one of the most promising candidate alloys and was selected for comprehensive tests and examination. In the present investigation, thermal creep rates and stress-rupture life of V-4Cr-4Ti and V-10Cr-STi alloys were determined at 600 degrees C. The impurity composition and microstructural characteristics of creep-tested specimens were analyzed and correlated with the measured creep properties. The results of these tests shaw that V-4Cr-4Ti, which contains impurity compositions typical of a commercially fabricated vanadium-based alloy, exhibits creep strength substantially superior to that of V-20Ti, HT-9, or type 316 stainless steel. The V-10Cr-5Ti alloy exhibits creep strength somewhat higher than that of V-4Cr-4Ti. RP CHUNG, HM (reprint author), ARGONNE NATL LAB, 9700 S CASS AVE, ARGONNE, IL 60439 USA. NR 9 TC 14 Z9 15 U1 0 U2 1 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0022-3115 J9 J NUCL MATER JI J. Nucl. Mater. PD SEP PY 1994 VL 212 BP 772 EP 777 DI 10.1016/0022-3115(94)90161-9 PN A PG 6 WC Materials Science, Multidisciplinary; Nuclear Science & Technology SC Materials Science; Nuclear Science & Technology GA PK613 UT WOS:A1994PK61300136 ER PT J AU GELLES, DS STUBBINS, JF AF GELLES, DS STUBBINS, JF TI MICROSTRUCTURAL DEVELOPMENT IN IRRADIATED VANADIUM ALLOYS SO JOURNAL OF NUCLEAR MATERIALS LA English DT Article; Proceedings Paper CT 6th International Conference on Fusion Reactor Materials (ICFRM-6) CY SEP 27-OCT 01, 1993 CL STRESA, ITALY SP COMMISS EUROPEAN UNION, JOINT RES CTR, INST ADV MAT ID NEUTRON-IRRADIATION; HELIUM; DAMAGE; FFTF AB Three simple vanadium alloys, V-5Al, V-1Ni, and V-2Ti-1Ni have been examined to determine the effects of fast neutron irradiation on microstructural evolution. Specimens were irradiated in EBR II at temperatures in the range 425 to 600 degrees C to doses of 15 and 31 dpa. Each alloy responded very differently to irradiation. All V-5Al specimens were generally void-free and contained high densities of coherent precipitates, and moderate densities of network dislocations. Swelling was much higher in V-1Ni. Voids were uniformly distributed, but with widely varying shape and size. Precipitation of two types also developed. The response in V-2Ti-1Ni was intermediate to that of the other two alloys. Irradiation produced extensive precipitation of thin rods and a moderate density of large voids often associated with much larger precipitate particles. The dislocation structure strongly interacted with the rod precipitate particles. C1 UNIV ILLINOIS, URBANA, IL 61801 USA. RP GELLES, DS (reprint author), PACIFIC NW LAB, POB 999, RICHLAND, WA 99352 USA. NR 15 TC 9 Z9 9 U1 0 U2 0 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0022-3115 J9 J NUCL MATER JI J. Nucl. Mater. PD SEP PY 1994 VL 212 BP 778 EP 783 DI 10.1016/0022-3115(94)90162-7 PN A PG 6 WC Materials Science, Multidisciplinary; Nuclear Science & Technology SC Materials Science; Nuclear Science & Technology GA PK613 UT WOS:A1994PK61300137 ER PT J AU LOOMIS, BA NOWICKI, LJ SMITH, DL AF LOOMIS, BA NOWICKI, LJ SMITH, DL TI EFFECT OF NEUTRON-IRRADIATION ON TENSILE PROPERTIES OF V-CR-TI ALLOYS SO JOURNAL OF NUCLEAR MATERIALS LA English DT Article; Proceedings Paper CT 6th International Conference on Fusion Reactor Materials (ICFRM-6) CY SEP 27-OCT 01, 1993 CL STRESA, ITALY SP COMMISS EUROPEAN UNION, JOINT RES CTR, INST ADV MAT ID FUSION AB The tensile properties of V-4Cr-4Ti, V-9Cr-5Ti, V-14Cr-5Ti, V-3Ti-1Si, V-5Ti, and V-18Ti alloys were determined at 25, 420, 520, and 600 degrees C after neutron irradiation to 28-46 dpa at 420, 520, and 600 degrees C. The yield strength of the unirradiated alloys increased significantly (similar to 50%) upon neutron irradiation. Irradiation hardening of the alloys at 25 degrees C after irradiation at 420 degrees C was in the order of V-18Ti < V-3Ti-1Si < V-5Ti < V-4Cr-4Ti < V-9Cr-5Ti < V-14Cr-5Ti. Total elongation of the irradiated alloys at 25 degrees C after irradiation at 420 degrees C ranged from 3 to 11%, with total elongation of the alloys in the order of V-14Cr-5Ti < V-9Cr-5Ti < V-3Ti-1Si < V-5Ti < V-4Cr-4Ti < V-18Ti. The total elongation of the alloys at 600 degrees C after irradiation ranged from 11 to 23%, with total elongation of the alloys in the order of V-14Cr-STi < V-9Cr-5Ti < V-4Cr-4Ti < V-5Ti < V-3Ti-1Si < V-18Ti. RP LOOMIS, BA (reprint author), ARGONNE NATL LAB, 9700 S CASS AVE, ARGONNE, IL 60439 USA. NR 8 TC 20 Z9 20 U1 0 U2 1 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0022-3115 J9 J NUCL MATER JI J. Nucl. Mater. PD SEP PY 1994 VL 212 BP 790 EP 793 DI 10.1016/0022-3115(94)90164-3 PN A PG 4 WC Materials Science, Multidisciplinary; Nuclear Science & Technology SC Materials Science; Nuclear Science & Technology GA PK613 UT WOS:A1994PK61300139 ER PT J AU LOOMIS, BA CHUNG, HM NOWICKI, LJ SMITH, DL AF LOOMIS, BA CHUNG, HM NOWICKI, LJ SMITH, DL TI EFFECTS OF NEUTRON-IRRADIATION AND HYDROGEN ON DUCTILE-BRITTLE TRANSITION-TEMPERATURES OF V-CR-TI ALLOYS SO JOURNAL OF NUCLEAR MATERIALS LA English DT Article; Proceedings Paper CT 6th International Conference on Fusion Reactor Materials (ICFRM-6) CY SEP 27-OCT 01, 1993 CL STRESA, ITALY SP COMMISS EUROPEAN UNION, JOINT RES CTR, INST ADV MAT ID FUSION AB The effects of neutron irradiation and hydrogen on the ductile-brittle transition temperatures (DBTTs) of unalloyed vanadium and V-Cr-Ti alloys were determined from Charpy-impact tests on 1/3 ASTM-standard-size specimens and from impact tests on 3-mm diameter discs. The tests were conducted on specimens containing < 30 appm hydrogen and 600-1200 appm hydrogen and on specimens after neutron irradiation to 28-46 atom displacements per atom at 420, 520, and 600 degrees C. The DBTTs were minimum (< -220 degrees C) for V-(1-5)Ti alloys and for V-4Cr-4Ti alloy with < 30 appm hydrogen. The effect of 600-1200 appm hydrogen in the specimens was to raise the DBTTs by 60-100 degrees C. The DBTTs were minimum (< -200 degrees C) for V-(3-5)Ti and V-4Cr-4Ti alloys after neutron irradiation. RP LOOMIS, BA (reprint author), ARGONNE NATL LAB, 9700 S CASS AVE, ARGONNE, IL 60439 USA. NR 9 TC 51 Z9 52 U1 0 U2 2 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0022-3115 J9 J NUCL MATER JI J. Nucl. Mater. PD SEP PY 1994 VL 212 BP 799 EP 803 DI 10.1016/0022-3115(94)90166-X PN A PG 5 WC Materials Science, Multidisciplinary; Nuclear Science & Technology SC Materials Science; Nuclear Science & Technology GA PK613 UT WOS:A1994PK61300141 ER PT J AU CHUNG, HM LOOMIS, BA SMITH, DL AF CHUNG, HM LOOMIS, BA SMITH, DL TI EFFECT OF IRRADIATION DAMAGE AND HELIUM ON SWELLING AND STRUCTURE OF VANADIUM-BASE ALLOYS SO JOURNAL OF NUCLEAR MATERIALS LA English DT Article; Proceedings Paper CT 6th International Conference on Fusion Reactor Materials (ICFRM-6) CY SEP 27-OCT 01, 1993 CL STRESA, ITALY SP COMMISS EUROPEAN UNION, JOINT RES CTR, INST ADV MAT ID FUSION-REACTORS; MICROSTRUCTURE; ACTIVATION AB Swelling behavior and microstructural evolution of V-Ti, V-Cr-Ti, and V-Ti-Si alloys were investigated after irradiation at 420-600 degrees C up to 114 dpa. The alloys exhibited swelling maxima between 30 and 80 dpa and swelling decreased on irradiation to higher dpa. This is in contrast to the monotonically increasing swelling of binary alloys that contain Fe, Ni, Cr, Mo, and Si. Precipitation of dense Ti5Si3 promotes good resistance to swelling of the Ti-containing alloys, and it was concluded that Ti of > 3 wt% and 400-1000 wppm Si are necessary to effectively suppress swelling. Swelling was minimal in V-4Cr-4Ti, identified as the most promising alloy based on good mechanical properties and superior resistance to irradiation embrittlement. V-20Ti doped with B exhibited somewhat higher swelling because of He generation. Lithium atoms, generated from transmutation of B-10, formed gamma-LiV2O5 precipitates and did not seem to produce undesirable effects on mechanical properties. RP CHUNG, HM (reprint author), ARGONNE NATL LAB, 9700 S CASS AVE, ARGONNE, IL 60439 USA. NR 38 TC 30 Z9 30 U1 3 U2 8 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0022-3115 J9 J NUCL MATER JI J. Nucl. Mater. PD SEP PY 1994 VL 212 BP 804 EP 812 DI 10.1016/0022-3115(94)90167-8 PN A PG 9 WC Materials Science, Multidisciplinary; Nuclear Science & Technology SC Materials Science; Nuclear Science & Technology GA PK613 UT WOS:A1994PK61300142 ER PT J AU DAVIS, JW ULRICKSON, MA CAUSEY, RA AF DAVIS, JW ULRICKSON, MA CAUSEY, RA TI USE OF TITANIUM IN FUSION COMPONENTS SO JOURNAL OF NUCLEAR MATERIALS LA English DT Article; Proceedings Paper CT 6th International Conference on Fusion Reactor Materials (ICFRM-6) CY SEP 27-OCT 01, 1993 CL STRESA, ITALY SP COMMISS EUROPEAN UNION, JOINT RES CTR, INST ADV MAT AB In the late 1970s, titanium was of interest to the fusion program because of its large unirradiated material property database, mature supplier and fabrication industry, low cost, and large mineral reserves. At that time there were a number of other competing structural materials such as stainless steels, ferritic steels, nicker base alloys, refractory metals (niobium and vanadium), and ordered alloys. The majority of these materials had higher operating temperatures which allowed for higher thermal conversion efficiencies. The,lower operating temperature coupled with a lack of an irradiation database and the potential for high tritium inventory made titanium unattractive for further study. Today, with the greater emphasis in the US on reduced radioactivation and waste management, the case for titanium is being reassessed. This paper looks at the issues regarding the use of titanium in fusion and discusses the results of experimental activities initiated to resolve those issues. C1 SANDIA NATL LABS, ALBUQUERQUE, NM 87185 USA. SANDIA NATL LABS, LIVERMORE, CA 94551 USA. RP DAVIS, JW (reprint author), MCDONNELL DOUGLAS CORP, POB 516, ST LOUIS, MO 63166 USA. NR 9 TC 21 Z9 24 U1 0 U2 0 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0022-3115 J9 J NUCL MATER JI J. Nucl. Mater. PD SEP PY 1994 VL 212 BP 813 EP 817 DI 10.1016/0022-3115(94)90168-6 PN A PG 5 WC Materials Science, Multidisciplinary; Nuclear Science & Technology SC Materials Science; Nuclear Science & Technology GA PK613 UT WOS:A1994PK61300143 ER PT J AU JONES, RH HENAGER, CH AF JONES, RH HENAGER, CH TI HIGH-TEMPERATURE PROPERTIES OF SIC/SIC FOR FUSION APPLICATIONS SO JOURNAL OF NUCLEAR MATERIALS LA English DT Article; Proceedings Paper CT 6th International Conference on Fusion Reactor Materials (ICFRM-6) CY SEP 27-OCT 01, 1993 CL STRESA, ITALY SP COMMISS EUROPEAN UNION, JOINT RES CTR, INST ADV MAT ID FATIGUE; BEHAVIOR; COMPOSITE; FRACTURE; CERAMICS; GLASS AB Ceramic matrix composites (CMCs) such as SiC/SiC exhibit novel mechanical properties relative to their monolithic counterparts. The crack velocity (da/dt) versus stress intensity (K) relationship for monolithic ceramics can be described by a simple power law relationship whereas SiC/SiC was found to exhibit a multistage da/dt versus K relationship similar to that for stress corrosion of metals. A K-independent stage II was followed by a strongly K-dependent stage III similar to monolithic materials. Evidence also exists that the fracture resistance of these materials is greater if cracks are produced by subcritical growth processes relative to machined notches. Oxygen was found to increase da/dt and decrease the K for the stage II to stage III transition while cyclic loads produced little damage at low K values but there was some evidence for increasing damage with increasing number of cycles and K. RP JONES, RH (reprint author), PACIFIC NW LAB, POB 999, RICHLAND, WA 99352 USA. OI Henager, Chuck/0000-0002-8600-6803 NR 15 TC 19 Z9 19 U1 0 U2 1 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0022-3115 J9 J NUCL MATER JI J. Nucl. Mater. PD SEP PY 1994 VL 212 BP 830 EP 834 DI 10.1016/0022-3115(94)90171-6 PN A PG 5 WC Materials Science, Multidisciplinary; Nuclear Science & Technology SC Materials Science; Nuclear Science & Technology GA PK613 UT WOS:A1994PK61300146 ER PT J AU RAGHURAMAN, S STUBBINS, JF FERBER, MK WERESZCZAK, AA AF RAGHURAMAN, S STUBBINS, JF FERBER, MK WERESZCZAK, AA TI CRACK-PROPAGATION IN SICF/SIC CERAMIC-MATRIX COMPOSITE UNDER STATIC AND CYCLIC LOADING CONDITIONS SO JOURNAL OF NUCLEAR MATERIALS LA English DT Article; Proceedings Paper CT 6th International Conference on Fusion Reactor Materials (ICFRM-6) CY SEP 27-OCT 01, 1993 CL STRESA, ITALY SP COMMISS EUROPEAN UNION, JOINT RES CTR, INST ADV MAT AB SiCf/SiC ceramic matrix composite material is of high interest for potential application as a structural and barrier material in fusion systems. It possesses reasonable fracture toughness over a range of temperatures and, due to the low atomic number of its constituents, is appealing for low activation reasons. This study examines the mechanical durability of a Nicalon fiber-SiC composite which has been tested at temperatures up to 1400 degrees C to determine its resistance to crack propagation under static and cyclic loading conditions. The crack growth characteristics are governed by the fiber and interface failure modes. These, in turn are affected by loading parameters, temperature and environmental effects. The material shows R-curve behavior, due to fiber bridging of the crack wake. The material also shows time dependent crack growth at elevated temperature, but not at room temperature. However, cyclic loading does induce crack extension at room temperature. C1 OAK RIDGE NATL LAB, HIGH TEMP MAT LAB, OAK RIDGE, TN 37830 USA. RP RAGHURAMAN, S (reprint author), UNIV ILLINOIS, DEPT NUCL ENGN, URBANA, IL 61801 USA. RI Wereszczak, Andrew/I-7310-2016; OI Wereszczak, Andrew/0000-0002-8344-092X; Srinivasan, Raghuraman/0000-0002-5333-1810 NR 6 TC 3 Z9 3 U1 0 U2 2 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0022-3115 J9 J NUCL MATER JI J. Nucl. Mater. PD SEP PY 1994 VL 212 BP 840 EP 844 DI 10.1016/0022-3115(94)90173-2 PN A PG 5 WC Materials Science, Multidisciplinary; Nuclear Science & Technology SC Materials Science; Nuclear Science & Technology GA PK613 UT WOS:A1994PK61300148 ER PT J AU HUMER, K WEBER, HW TSCHEGG, EK EGUSA, S BIRTCHER, RC GERSTENBERG, H AF HUMER, K WEBER, HW TSCHEGG, EK EGUSA, S BIRTCHER, RC GERSTENBERG, H TI TENSILE-STRENGTH OF FIBER-REINFORCED PLASTICS AT 77-K IRRADIATED BY VARIOUS RADIATION SOURCES SO JOURNAL OF NUCLEAR MATERIALS LA English DT Article; Proceedings Paper CT 6th International Conference on Fusion Reactor Materials (ICFRM-6) CY SEP 27-OCT 01, 1993 CL STRESA, ITALY SP COMMISS EUROPEAN UNION, JOINT RES CTR, INST ADV MAT ID POLYMER MATRIX COMPOSITES; MECHANICAL-PROPERTIES; ROOM-TEMPERATURE; GAMMA-RAYS; CRYOGENIC TEMPERATURES; NEUTRON-IRRADIATION; ORGANIC INSULATORS; FUSION-MAGNET; 5 K; DEGRADATION AB The influence of radiation damage on the mechanical properties of fiber reinforced plastics (FRPs) has been investigated. Three aspects of our results will be discussed in detail. The first is related to an assessment of the tensile strength and its radiation dependence under the influence of strongly varying radiation conditions; the second to low temperature (similar to 5 K) reactor irradiation of selected materials. In this case, identical sets of tensile test samples were transferred into the tensile testing machine, one without warming-up to room temperature and the other after an annealing cycle to room temperature. Finally, a comparison between the radiation response of different materials shows that the tensile properties of a three-dimensionally reinforced bismaleimide degrade least under all irradiation conditions. C1 VIENNA TECH UNIV, INST ANGEW & TECH PHYS, A-1040 VIENNA, AUSTRIA. JAPAN ATOM ENERGY RES INST, TAKASAKI RADIAT CHEM RES ESTAB, TAKASAKI, GUMMA 37012, JAPAN. ARGONNE NATL LAB, DIV MAT SCI, ARGONNE, IL 60439 USA. TECH UNIV MUNICH, FAC PHYS, W-8046 GARCHING, GERMANY. RP HUMER, K (reprint author), UNIV VIENNA, ATOMINST, A-1020 VIENNA, AUSTRIA. NR 27 TC 6 Z9 6 U1 0 U2 0 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0022-3115 J9 J NUCL MATER JI J. Nucl. Mater. PD SEP PY 1994 VL 212 BP 849 EP 853 DI 10.1016/0022-3115(94)90175-9 PN A PG 5 WC Materials Science, Multidisciplinary; Nuclear Science & Technology SC Materials Science; Nuclear Science & Technology GA PK613 UT WOS:A1994PK61300150 ER PT J AU VERRALL, RA SLAGLE, OD HOLLENBERG, GW KURASAWA, T SULLIVAN, JD AF VERRALL, RA SLAGLE, OD HOLLENBERG, GW KURASAWA, T SULLIVAN, JD TI IRRADIATION OF LITHIUM ZIRCONATE PEBBLE-BED IN BEATRIX-II PHASE-II SO JOURNAL OF NUCLEAR MATERIALS LA English DT Article; Proceedings Paper CT 6th International Conference on Fusion Reactor Materials (ICFRM-6) CY SEP 27-OCT 01, 1993 CL STRESA, ITALY SP COMMISS EUROPEAN UNION, JOINT RES CTR, INST ADV MAT ID BREEDER MATERIALS AB BEATRIX-II was an in-situ tritium recovery experiment that was designed to characterize the behavior of lithium ceramics irradiated to a high burnup, and to assess their suitability for use in a fusion reactor blanket. This paper describes the results from the vented canister containing 29.47 g of lithium zirconate spheres packed in a bed 13.2 mm OD, 2.3 mm ID and 103 mm long. The enriched lithium spheres (85% Li-6) were irradiated to a burnup of 5.2% (total lithium) in a steep temperature profile - 400 degrees C edge, 1100 degrees C center. The sweep gas was He-0.1% H,, with systematic tests using alternate compositions: He-0.01% H-2 and pure He (maximum duration 8 days). Tritium recovery decreased slightly at lower H, concentrations; for example, the buildup of inventory during a 4-day test in pure He was 0.8 Ci, approximately 6.5% of the tritium generated in the lithium zirconate during that period. The steadiness of the bed central temperature and the tritium release rate, together with low moisture release indicate good performance of the zirconate bed. C1 PACIFIC NW LAB, RICHLAND, WA 99352 USA. JAPAN ATOM ENERGY RES INST, TOKAI, IBARAKI, JAPAN. RP VERRALL, RA (reprint author), AECL RES, CHALK RIVER LABS, CHALK RIVER K0J 1J0, ON, CANADA. NR 14 TC 12 Z9 12 U1 0 U2 0 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0022-3115 J9 J NUCL MATER JI J. Nucl. Mater. PD SEP PY 1994 VL 212 BP 902 EP 907 DI 10.1016/0022-3115(94)90966-0 PN B PG 6 WC Materials Science, Multidisciplinary; Nuclear Science & Technology SC Materials Science; Nuclear Science & Technology GA PL245 UT WOS:A1994PL24500010 ER PT J AU MASAKI, NM NODA, K WATANABE, H CLEMMER, RG HOLLENBERG, GW AF MASAKI, NM NODA, K WATANABE, H CLEMMER, RG HOLLENBERG, GW TI SPECTROSCOPIC STUDY OF LITHIUM-OXIDE IRRADIATED BY FAST-NEUTRONS SO JOURNAL OF NUCLEAR MATERIALS LA English DT Article; Proceedings Paper CT 6th International Conference on Fusion Reactor Materials (ICFRM-6) CY SEP 27-OCT 01, 1993 CL STRESA, ITALY SP COMMISS EUROPEAN UNION, JOINT RES CTR, INST ADV MAT ID ELECTRON-SPIN-RESONANCE; RADIATION-DAMAGE; LI2O AB Lithium oxide (Li2O) is a candidate material for solid breeder blankets in d-t fusion reactors. Radiation damage in Li2O was investigated in IEA BEATRIX-II phase 1 irradiation tests using the Fast Flux Test Facility (FFTF). Li2O single crystal specimens with various Li-6 concentrations, Li-6/(Li-6 + Li-7), were irradiated at about 650 K for 300 effective full power days in FFTF by fast neutrons (the fast neutron fluence (> 0.1 MeV): 3.9 x 10(26) n/m(2)). After the neutron-irradiation, measurements of electron-spin resonance (ESR) and optical absorption were carried out for the specimens at room temperature. From the measurements, colloidal lithium metal was found to be formed in Li2O irradiated with fast neutrons. C1 PACIFIC NW LAB, RICHLAND, WA 99352 USA. RP MASAKI, NM (reprint author), JAPAN ATOM ENERGY RES INST, TOKAI, IBARAKI 31911, JAPAN. NR 14 TC 17 Z9 17 U1 0 U2 2 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0022-3115 J9 J NUCL MATER JI J. Nucl. Mater. PD SEP PY 1994 VL 212 BP 908 EP 911 DI 10.1016/0022-3115(94)90967-9 PN B PG 4 WC Materials Science, Multidisciplinary; Nuclear Science & Technology SC Materials Science; Nuclear Science & Technology GA PL245 UT WOS:A1994PL24500011 ER PT J AU KOPASZ, JP SEILS, CA JOHNSON, CE AF KOPASZ, JP SEILS, CA JOHNSON, CE TI SPATIAL TRITIUM TRANSPORT IN SINGLE-CRYSTAL LITHIUM ALUMINATE SO JOURNAL OF NUCLEAR MATERIALS LA English DT Article; Proceedings Paper CT 6th International Conference on Fusion Reactor Materials (ICFRM-6) CY SEP 27-OCT 01, 1993 CL STRESA, ITALY SP COMMISS EUROPEAN UNION, JOINT RES CTR, INST ADV MAT ID RELEASE AB Isothermal anneal tests have been performed on large single-crystal samples (approximately 1.5 mm diameter) of LiAlO2 in an attempt to determine the diffusivity of tritium in lithium aluminate. To understand the effects-of impurities on the tritium transport, single crystals of Mg-doped LiAlO2 were also studied. The crystals were sectioned after annealing to determine the tritium concentration profiles within the crystals. From these profiles the tritium diffusivity, D, and the desorption rate constant, K, were calculated. The tritium diffusivities determined for the doped and undoped materials were the same within experimental error. The measured diffusivity is given by In D(m(2)/s)= -11.8 - (1.50 x 10(4))/T. Tritium release for these samples was generally in the mixed diffusion-desorption regime, as determined from the ratio aK/D, where a is the grain radius. Our data indicate that for grain radii less than 100 mu m, the tritium transport will be in the desorption-controlled regime. RP KOPASZ, JP (reprint author), ARGONNE NATL LAB, DIV CHEM TECHNOL, 9700 S CASS AVE, ARGONNE, IL 60439 USA. NR 12 TC 13 Z9 14 U1 1 U2 5 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0022-3115 J9 J NUCL MATER JI J. Nucl. Mater. PD SEP PY 1994 VL 212 BP 912 EP 916 DI 10.1016/0022-3115(94)90968-7 PN B PG 5 WC Materials Science, Multidisciplinary; Nuclear Science & Technology SC Materials Science; Nuclear Science & Technology GA PL245 UT WOS:A1994PL24500012 ER PT J AU KOPASZ, JP MILLER, JM JOHNSON, CE AF KOPASZ, JP MILLER, JM JOHNSON, CE TI TRITIUM RELEASE FROM LITHIUM TITANATE, A LOW-ACTIVATION TRITIUM BREEDING MATERIAL SO JOURNAL OF NUCLEAR MATERIALS LA English DT Article; Proceedings Paper CT 6th International Conference on Fusion Reactor Materials (ICFRM-6) CY SEP 27-OCT 01, 1993 CL STRESA, ITALY SP COMMISS EUROPEAN UNION, JOINT RES CTR, INST ADV MAT AB The goals for fusion power are to produce energy in as safe, economical, and environmentally benign a manner as possible. To ensure environmentally sound operation low-activation materials should be used where feasible. The ARIES Tokamak Reactor Study has based reactor designs on the concept of using low-activation materials throughout the fusion reactor. For the tritium breeding blanket, the choices for low activation tritium breeding materials are limited. Lithium titanate ii an alternative low-activation ceramic material for use in the tritium breeding blanket. To date, very little work has been done on characterizing the tritium release for lithium titanate. We have thus performed laboratory studies of tritium release from irradiated lithium titanate. The results indicate that tritium is easily removed from lithium titanate at temperatures as low as 600 K. The method of titanate preparation was found to affect the tritium release, and the addition of 0.1% H-2 to the helium purge gas did not improve tritium recovery. C1 AECL RES, CHALK RIVER LABS, CHALK RIVER K0J 1J0, ON, CANADA. RP KOPASZ, JP (reprint author), ARGONNE NATL LAB, DIV CHEM TECHNOL, 9700 S CASS AVE, ARGONNE, IL 60439 USA. NR 9 TC 44 Z9 46 U1 1 U2 7 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0022-3115 J9 J NUCL MATER JI J. Nucl. Mater. PD SEP PY 1994 VL 212 BP 927 EP 931 DI 10.1016/0022-3115(94)90971-7 PN B PG 5 WC Materials Science, Multidisciplinary; Nuclear Science & Technology SC Materials Science; Nuclear Science & Technology GA PL245 UT WOS:A1994PL24500015 ER PT J AU BALDWIN, DL BILLONE, MC AF BALDWIN, DL BILLONE, MC TI DIFFUSION/DESORPTION OF TRITIUM FROM IRRADIATED BERYLLIUM SO JOURNAL OF NUCLEAR MATERIALS LA English DT Article; Proceedings Paper CT 6th International Conference on Fusion Reactor Materials (ICFRM-6) CY SEP 27-OCT 01, 1993 CL STRESA, ITALY SP COMMISS EUROPEAN UNION, JOINT RES CTR, INST ADV MAT AB Stepped-isothermal anneal tritium release measurements at 573 up to 1173 K have been performed on irradiated Be test materials, fabricated and irradiated to meet conditions relevant to the International Thermonuclear Experimental Reactor (ITER). A combined diffusion/desorption model for tritium release allows determination of diffusion coefficients and desorption-rate constants in the mixed-mechanism regime where both diffusion and surface desorption appear to be rate-limiting. The effective tritium diffusivities (m(2)/s) for these materials, and also from new data analysis of previously reported fully dense material, were found to be 81% TD Be: 1.7x10(-11) exp(-3.4 DJ/mol/RT), 99% TD Be: 1.6x10(-1)0 exp(-9.5 kJ/mol/RT), 100% TD Be: 1.4x10(-10) exp(-11.5 kJ/mol/RT). Tritium release data for both the 81% TD and the 99% TD sample were matched reasonably well by the diffusion/desorption model. The model provides evidence for a changing mechanism over both temperature and density, but indicates that diffusion is the primary mechanism with a small and changing contribution from surface desorption. C1 ARGONNE NATL LAB, ARGONNE, IL 60439 USA. RP BALDWIN, DL (reprint author), PACIFIC NW LAB, POB 999, RICHLAND, WA 99352 USA. NR 12 TC 36 Z9 36 U1 1 U2 3 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0022-3115 J9 J NUCL MATER JI J. Nucl. Mater. PD SEP PY 1994 VL 212 BP 948 EP 953 DI 10.1016/0022-3115(94)90975-X PN B PG 6 WC Materials Science, Multidisciplinary; Nuclear Science & Technology SC Materials Science; Nuclear Science & Technology GA PL245 UT WOS:A1994PL24500019 ER PT J AU JOHNSON, CE BALDWIN, DL KOPASZ, JP AF JOHNSON, CE BALDWIN, DL KOPASZ, JP TI TRITIUM RELEASE FROM BERYLLIUM DISKS AND LITHIUM CERAMICS IRRADIATED IN THE SIBELIUS EXPERIMENT SO JOURNAL OF NUCLEAR MATERIALS LA English DT Article; Proceedings Paper CT 6th International Conference on Fusion Reactor Materials (ICFRM-6) CY SEP 27-OCT 01, 1993 CL STRESA, ITALY SP COMMISS EUROPEAN UNION, JOINT RES CTR, INST ADV MAT AB The SIBELIUS experiment was designed to obtain information on the compatibility between beryllium and ceramics, as well as beryllium and steel, in a neutron environment. This experiment comprised irradiation of eight capsules, seven of which were independently purged with a He/0.1% H-2 gas mixture. Four capsules were used to examine beryllium/ceramic (Li2O, LiAlO2, Li4SiO4, and Li2ZrO3) and beryllium/steel (Types 316L and 1.4914) compacts. Isothermal anneal experiments have been run on representative beryllium and ceramic disks from each of the four capsules at 550 to 850 degrees C in steps of 100 degrees C. The results indicate that tritium release from the beryllium did not exhibit burst release behavior, as previously reported, but rather a progressive release with increasing temperature. Generally, similar to 99% of the tritium was released by 850 degrees C. Tritium release from the ceramic discs was quite similar to the behavior shown in other dynamic tritium release experiments an lithium ceramics. The tritium content in beryllium discs adjacent to a steel sample was found to be significantly lower than that found in a beryllium disc adjacent to a ceramic sample. Recoil of tritium from the ceramic into the beryllium appears to be the source of tritium entering the beryllium, probably residing in the beryllium oxide layer. C1 PACIFIC NW LAB, DEPT CHEM SCI, RICHLAND, WA 99352 USA. RP JOHNSON, CE (reprint author), ARGONNE NATL LAB, DIV CHEM TECHNOL, 9700 S CASS AVE, ARGONNE, IL 60439 USA. NR 6 TC 2 Z9 2 U1 0 U2 0 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0022-3115 J9 J NUCL MATER JI J. Nucl. Mater. PD SEP PY 1994 VL 212 BP 966 EP 970 DI 10.1016/0022-3115(94)90978-4 PN B PG 5 WC Materials Science, Multidisciplinary; Nuclear Science & Technology SC Materials Science; Nuclear Science & Technology GA PL245 UT WOS:A1994PL24500022 ER PT J AU SLAGLE, OD TAKAHASHI, T HOBBS, FD NODA, K BALDWIN, DL HOLLENBERG, GW VERRALL, RA AF SLAGLE, OD TAKAHASHI, T HOBBS, FD NODA, K BALDWIN, DL HOLLENBERG, GW VERRALL, RA TI POSTIRRADIATION EXAMINATION OF BEATRIX-II, PHASE-I SO JOURNAL OF NUCLEAR MATERIALS LA English DT Article; Proceedings Paper CT 6th International Conference on Fusion Reactor Materials (ICFRM-6) CY SEP 27-OCT 01, 1993 CL STRESA, ITALY SP COMMISS EUROPEAN UNION, JOINT RES CTR, INST ADV MAT ID INSITU TRITIUM RECOVERY; LI2O AB BEATRIX-II is an in-situ tritium recovery experiment that was designed to characterize the behavior of lithium ceramics irradiated to high burnup in a fast neutron flux. Postirradiation examination was carried out on the Phase I vented canisters: one containing a Li2O ring capable of temperature changes and the other a Li2O solid specimen with a center temperature of 1000 degrees C. The tritium inventory of the ring specimen at 630 degrees C was determined to be in the range from 0.2-0.6 wppm, while for the solid specimen the inventory varied from 1.4 wppm at the surface to 0.06 wppm at the inner surface. Downstream transport of the Li2O by the sweep gas was determined to be insignificant from analyses of acid rinses of selected canister surfaces. Densification and restructuring of the solid specimen during irradiation resulted in the development of a central annulus. Ceramography was used to characterize the columnar grain structure and the mechanisms involved in its evolution. C1 JAPAN ATOM ENERGY RES INST, TOKAI, IBARAKI, JAPAN. AECL RES, CHALK RIVER LABS, CHALK RIVER K0J 1J0, ON, CANADA. RP SLAGLE, OD (reprint author), PACIFIC NW LAB, POB 999, RICHLAND, WA 99352 USA. NR 12 TC 7 Z9 7 U1 0 U2 0 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0022-3115 J9 J NUCL MATER JI J. Nucl. Mater. PD SEP PY 1994 VL 212 BP 988 EP 992 DI 10.1016/0022-3115(94)90982-2 PN B PG 5 WC Materials Science, Multidisciplinary; Nuclear Science & Technology SC Materials Science; Nuclear Science & Technology GA PL245 UT WOS:A1994PL24500026 ER PT J AU FEDERICI, G RAFFRAY, AR BILLONE, MC WU, CH CHO, S ABDOU, MA AF FEDERICI, G RAFFRAY, AR BILLONE, MC WU, CH CHO, S ABDOU, MA TI AN ASSESSMENT OF MODELS FOR TRITIUM RELEASE FROM CERAMIC BREEDERS FOR BLANKET ANALYSIS APPLICATIONS SO JOURNAL OF NUCLEAR MATERIALS LA English DT Article; Proceedings Paper CT 6th International Conference on Fusion Reactor Materials (ICFRM-6) CY SEP 27-OCT 01, 1993 CL STRESA, ITALY SP COMMISS EUROPEAN UNION, JOINT RES CTR, INST ADV MAT ID LITHIUM-BASE CERAMICS; COMPREHENSIVE MODEL; TRANSPORT AB Several models have been proposed and used to analyse the tritium release from ceramic breeder blankets. The transient models range from single-mechanism types of models to comprehensive, fully integrated models over a blanket spatial location, including all the key transport mechanisms, as well as local spatial temperature gradients. This paper considers different models available for analysis of tritium transport in ceramic breeders and performs a critical assessment of their applicability for blanket analysis and of their limits. Based on the analysis, the type of model which would be best suited for blanket analysis is described. It combines the possibility of including to a reasonable extent the effect of key transport mechanisms with the ease of integrating the computations over the whole blanket space, and provides the capability for both steady state and transient analyses. C1 UNIV CALIF LOS ANGELES, DEPT MECH AEROSP & NUCL ENGN, LOS ANGELES, CA 90024 USA. ARGONNE NATL LAB, DIV ENERGY TECHNOL, ARGONNE, IL 60439 USA. RP FEDERICI, G (reprint author), MAX PLANCK INST PLASMA PHYS, NET TEAM, BOLTZMANNSTR 2, D-85748 GARCHING, GERMANY. NR 20 TC 2 Z9 2 U1 0 U2 0 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0022-3115 J9 J NUCL MATER JI J. Nucl. Mater. PD SEP PY 1994 VL 212 BP 1003 EP 1009 DI 10.1016/0022-3115(94)90985-7 PN B PG 7 WC Materials Science, Multidisciplinary; Nuclear Science & Technology SC Materials Science; Nuclear Science & Technology GA PL245 UT WOS:A1994PL24500029 ER PT J AU LONGHURST, GR AF LONGHURST, GR TI A SIMPLIFIED MODEL FOR TRITIUM PERMEATION TRANSIENT PREDICTIONS WHEN TRAPPING IS ACTIVE SO JOURNAL OF NUCLEAR MATERIALS LA English DT Article; Proceedings Paper CT 6th International Conference on Fusion Reactor Materials (ICFRM-6) CY SEP 27-OCT 01, 1993 CL STRESA, ITALY SP COMMISS EUROPEAN UNION, JOINT RES CTR, INST ADV MAT AB This report describes a simplified one-dimensional tritium permeation and retention model. The model makes use of the same physical mechanisms as more sophisticated, time-transient codes such as implantation, recombination, diffusion, trapping and thermal gradient effects. It takes advantage of a number of simplifications and approximations to solve the steady-state problem and then provides interpolating functions to make estimates of intermediate states based on the steady-state solution. Comparison calculations with the verified and validated TMAP4 transient code show good agreement. RP LONGHURST, GR (reprint author), IDAHO NATL ENGN LAB, FUS SAFETY PROGRAM, POB 1625, IDAHO FALLS, ID 83415 USA. NR 7 TC 8 Z9 8 U1 0 U2 4 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0022-3115 J9 J NUCL MATER JI J. Nucl. Mater. PD SEP PY 1994 VL 212 BP 1015 EP 1020 DI 10.1016/0022-3115(94)90987-3 PN B PG 6 WC Materials Science, Multidisciplinary; Nuclear Science & Technology SC Materials Science; Nuclear Science & Technology GA PL245 UT WOS:A1994PL24500031 ER PT J AU KATANO, Y ZINKLE, SJ NAKATA, K HISHINUMA, A OHNO, H AF KATANO, Y ZINKLE, SJ NAKATA, K HISHINUMA, A OHNO, H TI MICROSTRUCTURAL EVOLUTION IN ION-IRRADIATED AND/OR ELECTRON-IRRADIATED SINGLE-CRYSTAL AL2O3 SO JOURNAL OF NUCLEAR MATERIALS LA English DT Article ID RADIATION-DAMAGE; DISPLACEMENT; SCALE AB Pure and Cr2O3-doped single crystal alpha-Al2O3 specimens were irradiated with 330 keV O+-ions, 400 keV He+-ions and 120 keV electrons at temperatures of 1123 to 1323 K, and the damage structure was studied by transmission electron microscopy. Dislocations, cavities and gamma-Al2O3 grains recrystallized from alpha-Al2O3 were formed by O-ion irradiation at 1223 K. The damage region extended to a depth of about twice as large as the peak damage depth predicted by TRIM85, and cracking occurred in the deeper part of the region. Recrystallization and cracking were not observed in the specimen irradiated with He-ions up to nearly the same dose as the case of O-ion irradiation. Instead, dislocation loops and cavities were observed. Damage near surface on basal planes occurred during 120 keV electron irradiation at 1273 K in the He preirradiated pure Al2O3 specimen. C1 OAK RIDGE NATL LAB, DIV MET & CERAM, OAK RIDGE, TN 37831 USA. HITACHI LTD, HITACHI RES LAB, HITACHI, IBARAKI 317, JAPAN. RP JAPAN ATOM ENERGY RES INST, DEPT MAT SCI & ENGN, TOKAI, IBARAKI 31911, JAPAN. NR 18 TC 9 Z9 9 U1 0 U2 4 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 SEP PY 1994 VL 212 BP 1039 EP 1045 DI 10.1016/0022-3115(94)90991-1 PN B PG 7 WC Materials Science, Multidisciplinary; Nuclear Science & Technology SC Materials Science; Nuclear Science & Technology GA PL245 UT WOS:A1994PL24500035 ER PT J AU WHITE, DP AF WHITE, DP TI THE EFFECT OF IONIZING AND DISPLACIVE RADIATION ON THE THERMAL-CONDUCTIVITY OF ALUMINA AT LOW-TEMPERATURE SO JOURNAL OF NUCLEAR MATERIALS LA English DT Article; Proceedings Paper CT 6th International Conference on Fusion Reactor Materials (ICFRM-6) CY SEP 27-OCT 01, 1993 CL STRESA, ITALY SP COMMISS EUROPEAN UNION, JOINT RES CTR, INST ADV MAT ID AL2O3 AB The effects of radiation-produced vacancies and of radiation-induced electrical conductivity (RIC) on the thermal conductivity of alumina at low temperatures have been calculated. The phonon scattering relaxation times for these mechanisms have been used in the evaluation of the thermal conductivity integral in order to determine the effect each mechanism has on the lattice thermal conductivity of alumina. It is found that vacancy scattering can significantly reduce the thermal conductivity; for example, a vacancy concentration of 0.01 per atom leads to a fractional change in thermal conductivity of about 90%. It is also concluded that the scattering of phonons by electrons in the conduction band due to RIC does not lead to a large reduction in the thermal conductivity. RP WHITE, DP (reprint author), OAK RIDGE NATL LAB, POB 2008, OAK RIDGE, TN 37831 USA. NR 20 TC 4 Z9 4 U1 0 U2 2 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0022-3115 J9 J NUCL MATER JI J. Nucl. Mater. PD SEP PY 1994 VL 212 BP 1069 EP 1074 DI 10.1016/0022-3115(94)90997-0 PN B PG 6 WC Materials Science, Multidisciplinary; Nuclear Science & Technology SC Materials Science; Nuclear Science & Technology GA PL245 UT WOS:A1994PL24500041 ER PT J AU CLINARD, FW DIENST, W FARNUM, EH AF CLINARD, FW DIENST, W FARNUM, EH TI ISSUES RELATED TO MECHANICAL-PROPERTIES OF NEUTRON-IRRADIATED CERAMICS SO JOURNAL OF NUCLEAR MATERIALS LA English DT Article; Proceedings Paper CT 6th International Conference on Fusion Reactor Materials (ICFRM-6) CY SEP 27-OCT 01, 1993 CL STRESA, ITALY SP COMMISS EUROPEAN UNION, JOINT RES CTR, INST ADV MAT ID SILICON-CARBIDE; STRENGTH; DAMAGE; FUSION; AL2O3 AB Ceramics will be used for a number of applications in fusion devices, where their dielectric properties, high strength, refractoriness, or low activation characteristics are required. In all cases mechanical properties must be adequate for the use intended, and the material must tolerate irradiation damage without undue degradation. In this paper the damage response of four candidate ceramics is reviewed, major issues are identified, and recommendations made for future studies. C1 KERNFORSCHUNGSZENTRUM KARLSRUHE GMBH, INST MET FORSCH, ASSOC KFK EURATOM, W-7500 KARLSRUHE 1, GERMANY. RP CLINARD, FW (reprint author), LOS ALAMOS NATL LAB, POB 1663, LOS ALAMOS, NM 87545 USA. NR 23 TC 7 Z9 7 U1 1 U2 3 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0022-3115 J9 J NUCL MATER JI J. Nucl. Mater. PD SEP PY 1994 VL 212 BP 1075 EP 1080 DI 10.1016/0022-3115(94)90998-9 PN B PG 6 WC Materials Science, Multidisciplinary; Nuclear Science & Technology SC Materials Science; Nuclear Science & Technology GA PL245 UT WOS:A1994PL24500042 ER PT J AU GARNER, FA HOLLENBERG, GW HOBBS, FD RYAN, JL LI, Z BLACK, CA BRADT, RC AF GARNER, FA HOLLENBERG, GW HOBBS, FD RYAN, JL LI, Z BLACK, CA BRADT, RC TI DIMENSIONAL STABILITY, OPTICAL AND ELASTIC PROPERTIES OF MGAL2O4 SPINEL IRRADIATED IN FFTF TO VERY HIGH EXPOSURES SO JOURNAL OF NUCLEAR MATERIALS LA English DT Article; Proceedings Paper CT 6th International Conference on Fusion Reactor Materials (ICFRM-6) CY SEP 27-OCT 01, 1993 CL STRESA, ITALY SP COMMISS EUROPEAN UNION, JOINT RES CTR, INST ADV MAT ID CERAMICS AB Stoichiometric MgAl2O4 spinel specimens irradiated in FFTF-MOTA at temperatures between 385 and 750 degrees C to fluences ranging from 2.2 to 24.9 x 10(22) n/cm(2) (E > 0.1 MeV) darken significantly, but do not develop any significant loss in weight or change in dimensions. Similar behavior was observed in both single crystal and fully dense polycrystalline specimens. Measurements of elastic constants by an ultrasonic technique show that no measurable changes occur as a result of the irradiation. These and other results confirm the stability of this material for fusion applications. C1 ARGONNE NATL LAB, ARGONNE, IL 60439 USA. UNIV NEVADA, RENO, NV 89557 USA. RP GARNER, FA (reprint author), PACIFIC NW LAB, POB 999, RICHLAND, WA 99352 USA. NR 7 TC 32 Z9 32 U1 1 U2 2 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0022-3115 J9 J NUCL MATER JI J. Nucl. Mater. PD SEP PY 1994 VL 212 BP 1087 EP 1090 DI 10.1016/0022-3115(94)91000-6 PN B PG 4 WC Materials Science, Multidisciplinary; Nuclear Science & Technology SC Materials Science; Nuclear Science & Technology GA PL245 UT WOS:A1994PL24500044 ER PT J AU BLACK, CA GARNER, FA BRADT, RC AF BLACK, CA GARNER, FA BRADT, RC TI INFLUENCE OF HIGH-DOSE NEUTRON-IRRADIATION AT 385-DEGREES-C AND 750-DEGREES-C ON THE MICROHARDNESS OF MGAL2O4 SPINEL SO JOURNAL OF NUCLEAR MATERIALS LA English DT Article; Proceedings Paper CT 6th International Conference on Fusion Reactor Materials (ICFRM-6) CY SEP 27-OCT 01, 1993 CL STRESA, ITALY SP COMMISS EUROPEAN UNION, JOINT RES CTR, INST ADV MAT ID CERAMICS; DAMAGE AB High-purity specimens of stoichiometric MgAl2O4 single crystal spinel and a hot-pressed polycrystalline ceramic spinel were irradiated to exposures as large as 24.9 x 10(22) n Cm-2 (E > 0.1 MeV) in FFTF at 385 and 750 degrees C. The specimens did not develop any brittleness or fragility, and maintained their physical integrity. Microhardness measurements revealed that initially all specimens hardened a small amount and then recovered slightly. At the lower irradiation temperature, the dependence of microhardness on orientation observed prior to irradiation tended to disappear. There was also some evidence that a secondary slip system was being activated. Following 750 degrees C irradiation, the orientation dependence was not lost, and the evidence for activation of a secondary slip system was stronger. C1 PACIFIC NW LAB, RICHLAND, WA 99352 USA. RP BLACK, CA (reprint author), UNIV NEVADA, RENO, NV 89557 USA. NR 12 TC 17 Z9 17 U1 0 U2 0 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0022-3115 J9 J NUCL MATER JI J. Nucl. Mater. PD SEP PY 1994 VL 212 BP 1096 EP 1100 DI 10.1016/0022-3115(94)91002-2 PN B PG 5 WC Materials Science, Multidisciplinary; Nuclear Science & Technology SC Materials Science; Nuclear Science & Technology GA PL245 UT WOS:A1994PL24500046 ER PT J AU SNEAD, LL WHITE, DP ZINKLE, SJ AF SNEAD, LL WHITE, DP ZINKLE, SJ TI IN-CORE MEASUREMENT OF DC ELECTRICAL-CONDUCTIVITY OF CERAMICS SO JOURNAL OF NUCLEAR MATERIALS LA English DT Article; Proceedings Paper CT 6th International Conference on Fusion Reactor Materials (ICFRM-6) CY SEP 27-OCT 01, 1993 CL STRESA, ITALY SP COMMISS EUROPEAN UNION, JOINT RES CTR, INST ADV MAT ID RADIATION-INDUCED CONDUCTIVITY; FUSION INSULATORS; BREAKDOWN; AL2O3; REACTOR AB An in-situ de conductivity capsule has been constructed and tested at the high flux beam reactor (HFBR) at Brookhaven National Laboratory. The prototype capsule contained two alumina and one silicon nitride polycrystalline samples. In-situ measurement of the DC conductivity was made utilizing custom-made mineral insulated triaxial cables with a guard ring configuration for the samples and the sample holders. Sample and capsule temperatures were also measured in situ. This prototype capsule was designed to operate at ITER relevant temperatures of 80 degrees C (alumina) and 300 degrees C (alumina and silicon nitride) with an applied electric field of 133 V/mm. It is significant that a large prompt increase in conductivity occurred but that no permanent radiation-induced electrical degradation was observed in alumina after irradiation at 80 degrees C to a neutron dose of > 0.1 dpa. RP SNEAD, LL (reprint author), OAK RIDGE NATL LAB, DIV MET & CERAM, POB 2008, OAK RIDGE, TN 37831 USA. OI Zinkle, Steven/0000-0003-2890-6915 NR 23 TC 10 Z9 10 U1 0 U2 3 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0022-3115 J9 J NUCL MATER JI J. Nucl. Mater. PD SEP PY 1994 VL 212 BP 1107 EP 1112 DI 10.1016/0022-3115(94)91004-9 PN B PG 6 WC Materials Science, Multidisciplinary; Nuclear Science & Technology SC Materials Science; Nuclear Science & Technology GA PL245 UT WOS:A1994PL24500048 ER PT J AU FARNUM, EH CLINARD, FW SOMMER, WF KENNEDY, JC SHIKAMA, T AF FARNUM, EH CLINARD, FW SOMMER, WF KENNEDY, JC SHIKAMA, T TI SEARCH FOR RADIATION-INDUCED ELECTRICAL DEGRADATION IN ALUMINA DURING SPALLATION-NEUTRON IRRADIATION SO JOURNAL OF NUCLEAR MATERIALS LA English DT Article; Proceedings Paper CT 6th International Conference on Fusion Reactor Materials (ICFRM-6) CY SEP 27-OCT 01, 1993 CL STRESA, ITALY SP COMMISS EUROPEAN UNION, JOINT RES CTR, INST ADV MAT ID INDUCED CONDUCTIVITY; INSULATORS; AL2O3 AB de and ac electrical conductivity of alumina and sapphire were measured during irradiation with spallation neutrons at the Los Alamos Spallation Radiation Effects Facility to a fluence of about 0.02 dpa. Both ac and de voltages were applied during irradiation at 395, 615 and 655 degrees C in an attempt to measure radiation-induced electrical degradation (RIED). RIED-like effects were observed in the evacuated AC capsules, but no RIED was observed with the de capsules in about 1 atm of argon gas. The de measurements showed an initial high increase in conductivity followed by a continual decrease with increasing fluence. We believe that postirradiation conductivity measurements must be made to confirm the observed current increases in the ac capsules. C1 TOHOKU UNIV, INST MAT RES, OARAI, IBARAKI 31113, JAPAN. RP FARNUM, EH (reprint author), LOS ALAMOS NATL LAB, POB 1663, LOS ALAMOS, NM 87545 USA. RI Shikama, Tatsuo/C-3042-2011 NR 12 TC 18 Z9 18 U1 0 U2 0 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0022-3115 J9 J NUCL MATER JI J. Nucl. Mater. PD SEP PY 1994 VL 212 BP 1128 EP 1132 DI 10.1016/0022-3115(94)91008-1 PN B PG 5 WC Materials Science, Multidisciplinary; Nuclear Science & Technology SC Materials Science; Nuclear Science & Technology GA PL245 UT WOS:A1994PL24500052 ER PT J AU BOWERS, DA DAVIS, JW DINWIDDIE, RB AF BOWERS, DA DAVIS, JW DINWIDDIE, RB TI DEVELOPMENT OF 1-D CARBON COMPOSITES FOR PLASMA-FACING COMPONENTS SO JOURNAL OF NUCLEAR MATERIALS LA English DT Article; Proceedings Paper CT 6th International Conference on Fusion Reactor Materials (ICFRM-6) CY SEP 27-OCT 01, 1993 CL STRESA, ITALY SP COMMISS EUROPEAN UNION, JOINT RES CTR, INST ADV MAT AB Carbon-based materials continue to be proposed and utilized as plasma-facing surfaces in fusion devices because of their low atomic number and superior high temperature thermal properties. This study presents results of a carbon-carbon composite development program for high heat flux surfaces using one-dimensional (1-D), high thermal conductivity materials. Thermal conductivity testing of six 1-D composites was accomplished, along with coefficient of thermal expansion (CTE) tests. Results indicate progress toward achieving composites with very high conductivity, approaching pyrolytic graphite values. Several 1-D composites have room temperature thermal conductivities which exceed 500 W/m K in the parallel-to-fiber direction. Perpendicular-to-fiber direction conductivity values were typically more that an order of magnitude lower. Experimental CTE data show values up to 10 x 10(-6)/degrees C perpendicular to fibers and nearly zero values in the fiber direction. Mechanical property testing will be included in future efforts. C1 OAK RIDGE NATL LAB, HIGH TEMP MAT LAB, OAK RIDGE, TN 37831 USA. RP BOWERS, DA (reprint author), MCDONNELL DOUGLAS AEROSP, POB 516, ST LOUIS, MO 63166 USA. NR 6 TC 6 Z9 8 U1 0 U2 4 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0022-3115 J9 J NUCL MATER JI J. Nucl. Mater. PD SEP PY 1994 VL 212 BP 1163 EP 1167 DI 10.1016/0022-3115(94)91014-6 PN B PG 5 WC Materials Science, Multidisciplinary; Nuclear Science & Technology SC Materials Science; Nuclear Science & Technology GA PL245 UT WOS:A1994PL24500058 ER PT J AU HASSANEIN, A EHST, DA GAHL, J AF HASSANEIN, A EHST, DA GAHL, J TI BERYLLIUM AND GRAPHITE PERFORMANCE IN ITER DURING A DISRUPTION SO JOURNAL OF NUCLEAR MATERIALS LA English DT Article; Proceedings Paper CT 6th International Conference on Fusion Reactor Materials (ICFRM-6) CY SEP 27-OCT 01, 1993 CL STRESA, ITALY SP COMMISS EUROPEAN UNION, JOINT RES CTR, INST ADV MAT ID PLASMA DISRUPTIONS; JET; SIMULATION; DAMAGE AB Plasma disruptions are considered one of the most limiting factors for successful operation of magnetic fusion reactors. During a disruption, a sharp, rapid release of energy strikes components such as the divertor or limiter plates. Severe surface erosion and melting of these components may then occur. The amount of material eroded from both ablation and melting is important to the reactor design and component lifetime. The anticipated performance of both beryllium and graphite as plasma-facing materials during such abnormal events is analyzed and compared. Recent experimental data obtained with both plasma guns and electron beams are carefully evaluated and compared to results of analytical modeling, including vapor shielding effect. Initial results from plasma gun experiments indicate that the Be erosion rate is about five times larger than that for a graphite material under the same disruption conditions. Key differences between simulation experiments and reactor disruption on the net erosion rate, and consequently on the lifetime of the divertor plate, are discussed in detail. The advantages and disadvantages of Be over graphite as a divertor plasma-facing material are discussed. C1 UNIV NEW MEXICO, DEPT ELECT & COMP ENGN, ALBUQUERQUE, NM 87131 USA. RP HASSANEIN, A (reprint author), ARGONNE NATL LAB, 9700 S CASS AVE, ARGONNE, IL 60439 USA. NR 18 TC 13 Z9 13 U1 0 U2 2 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0022-3115 J9 J NUCL MATER JI J. Nucl. Mater. PD SEP PY 1994 VL 212 BP 1272 EP 1277 DI 10.1016/0022-3115(94)91034-0 PN B PG 6 WC Materials Science, Multidisciplinary; Nuclear Science & Technology SC Materials Science; Nuclear Science & Technology GA PL245 UT WOS:A1994PL24500078 ER PT J AU ROCKETT, PD HUNTER, JA GAHL, JM BRADLEY, JT PETERSON, RR AF ROCKETT, PD HUNTER, JA GAHL, JM BRADLEY, JT PETERSON, RR TI PLASMA GUN EXPERIMENTS AND MODELING OF DISRUPTIONS SO JOURNAL OF NUCLEAR MATERIALS LA English DT Article; Proceedings Paper CT 6th International Conference on Fusion Reactor Materials (ICFRM-6) CY SEP 27-OCT 01, 1993 CL STRESA, ITALY SP COMMISS EUROPEAN UNION, JOINT RES CTR, INST ADV MAT AB Potentially high erosion due to ablation from plasma disruptions looms as a nemesis for advanced fusion devices such as ITER. Under some conditions, it is believed that the material ablated during a disruption forms a ''vapor shield'' that mitigates subsequent ablation. This paper presents new experimental data that identifies an absorption surface in the ablating plasma that is above the irradiated armor surface. We also present a summary of progress in modeling using a 1-D Lagrangian hydrodynamics code. Experimental erosion data will be reviewed from the PLADIS facility, a plasma gun at the University of New Mexico on several materials, including Be, tungsten, copper, graphites. Profile measurements of the crater topology showed the eroded Be surface to be much rougher than that of carbon and to demonstrate erosion rates that were almost factors of four greater than graphite. Plasma guns at the D.V. Efremov Scientific Research Institute and at TRINITI, both in the Russian Federation, are being utilized to confirm spectroscopic vapor shield data. C1 UNIV NEW MEXICO, DEPT EECE, ALBUQUERQUE, NM 87131 USA. UNIV WISCONSIN, INST FUS TECHNOL, MADISON, WI 53706 USA. RP ROCKETT, PD (reprint author), SANDIA NATL LABS, POB 5800, ALBUQUERQUE, NM 87185 USA. NR 9 TC 9 Z9 9 U1 1 U2 2 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0022-3115 J9 J NUCL MATER JI J. Nucl. Mater. PD SEP PY 1994 VL 212 BP 1278 EP 1282 DI 10.1016/0022-3115(94)91035-9 PN B PG 5 WC Materials Science, Multidisciplinary; Nuclear Science & Technology SC Materials Science; Nuclear Science & Technology GA PL245 UT WOS:A1994PL24500079 ER PT J AU GARNER, FA STUBBINS, JF AF GARNER, FA STUBBINS, JF TI SATURATION OF SWELLING IN NEUTRON-IRRADIATED MOLYBDENUM AND ITS DEPENDENCE ON IRRADIATION TEMPERATURE AND STARTING MICROSTRUCTURAL STATE SO JOURNAL OF NUCLEAR MATERIALS LA English DT Article; Proceedings Paper CT 6th International Conference on Fusion Reactor Materials (ICFRM-6) CY SEP 27-OCT 01, 1993 CL STRESA, ITALY SP COMMISS EUROPEAN UNION, JOINT RES CTR, INST ADV MAT AB Molybdenum and its alloys are of interest for potential fusion application due to their high melting points and relatively good thermal conductivities. The development of void superlattices during neutron irradiation appears to limit void swelling in pure molybdenum to values below 4% over a wide range of irradiation temperatures. The saturation value of swelling and the void superlattice parameter each appear to be somewhat dependent on temperature, but independent of the thermomechanical starting state. Formation of technetium and ruthenium by transmutation may also play some minor role in the microstructural evolution, but do not appear to be involved in the limitation of swelling observed in this and other experiments. C1 UNIV ILLINOIS, URBANA, IL 61801 USA. RP GARNER, FA (reprint author), PACIFIC NW LAB, RICHLAND, WA 99352 USA. NR 14 TC 18 Z9 18 U1 0 U2 2 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0022-3115 J9 J NUCL MATER JI J. Nucl. Mater. PD SEP PY 1994 VL 212 BP 1298 EP 1302 DI 10.1016/0022-3115(94)91039-1 PN B PG 5 WC Materials Science, Multidisciplinary; Nuclear Science & Technology SC Materials Science; Nuclear Science & Technology GA PL245 UT WOS:A1994PL24500083 ER PT J AU SINGHAL, A STUBBINS, JF SINGH, BN GARNER, FA AF SINGHAL, A STUBBINS, JF SINGH, BN GARNER, FA TI ROOM-TEMPERATURE FATIGUE BEHAVIOR OF OFHC COPPER AND CUAL25 SPECIMENS OF 2 SIZES SO JOURNAL OF NUCLEAR MATERIALS LA English DT Article; Proceedings Paper CT 6th International Conference on Fusion Reactor Materials (ICFRM-6) CY SEP 27-OCT 01, 1993 CL STRESA, ITALY SP COMMISS EUROPEAN UNION, JOINT RES CTR, INST ADV MAT ID MEAN STRESS; GRAIN-SIZE; LIFE AB Copper and its alloys are appealing for application in fusion reactor systems for high heat flux components where high thermal conductivities are critical, for instance, in divertor components. The thermal and mechanical loading of such components will be, at least in part, cyclic in nature, thus requiring an understanding of their fatigue behavior. This paper describes the room temperature fatigue behavior of unirradiated OFHC (oxygen-free high-conductivity) copper and CuAl25 (copper strengthened with a 0.25% atom fraction dispersion of alumina). The response of two fatigue specimen sizes to strain controlled fatigue loading is examined, and differences in behavior are discussed. Specimens with the smaller size are now being irradiated in several reactors. C1 RISO NATL LAB, DEPT MAT, DK-4000 ROSKILDE, DENMARK. PACIFIC NW LAB, RICHLAND, WA 99352 USA. RP SINGHAL, A (reprint author), UNIV ILLINOIS, URBANA, IL 61801 USA. NR 12 TC 10 Z9 10 U1 0 U2 2 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0022-3115 J9 J NUCL MATER JI J. Nucl. Mater. PD SEP PY 1994 VL 212 BP 1307 EP 1312 DI 10.1016/0022-3115(94)91041-3 PN B PG 6 WC Materials Science, Multidisciplinary; Nuclear Science & Technology SC Materials Science; Nuclear Science & Technology GA PL245 UT WOS:A1994PL24500085 ER PT J AU EDWARDS, DJ GARNER, FA NEWKIRK, JW NADKARNI, A AF EDWARDS, DJ GARNER, FA NEWKIRK, JW NADKARNI, A TI NEUTRON-INDUCED MICROSTRUCTURAL ALTERATION OF GLIDCOP(TM) ALLOYS AT APPROXIMATE-TO-415-DEGREES-C AND HIGH NEUTRON EXPOSURE SO JOURNAL OF NUCLEAR MATERIALS LA English DT Article; Proceedings Paper CT 6th International Conference on Fusion Reactor Materials (ICFRM-6) CY SEP 27-OCT 01, 1993 CL STRESA, ITALY SP COMMISS EUROPEAN UNION, JOINT RES CTR, INST ADV MAT ID STRENGTHENED COPPER-ALLOYS; ION IRRADIATION; CONDUCTIVITY; STABILITY; DPA AB GlidCop(TM) internally oxidized copper alloys remain the leading candidates for high heat flux applications in fusion reactors. This paper presents the microstructural changes incurred in three GlidCop(TM) alloys exposed to long term, high temperature neutron irradiation. Irradiation at high temperature produced a microstructure containing a much lower dislocation density than the unirradiated specimens. Although 10-50 nm size triangular oxide particles were observed in areas with a very low number density of particles, spherical oxide particles on the order of 5-7 nm in diameter, thought to be CuAl2O4, were the predominant morphology. The changes in grain size distribution, dislocation density, and precipitate type and distribution saturate in the range of 34 to 50 dpa, as reflected in the saturation of mechanical properties. C1 UNIV MISSOURI, ROLLA, MO 65401 USA. SCM MET PROD, RES TRIANGLE PK, NC USA. RP EDWARDS, DJ (reprint author), PACIFIC NW LAB, POB 999, RICHLAND, WA 99352 USA. NR 13 TC 9 Z9 9 U1 0 U2 3 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0022-3115 J9 J NUCL MATER JI J. Nucl. Mater. PD SEP PY 1994 VL 212 BP 1313 EP 1317 DI 10.1016/0022-3115(94)91042-1 PN B PG 5 WC Materials Science, Multidisciplinary; Nuclear Science & Technology SC Materials Science; Nuclear Science & Technology GA PL245 UT WOS:A1994PL24500086 ER PT J AU DAVIS, JW DRIEMEYER, DE HAINES, JR MCGRATH, RT AF DAVIS, JW DRIEMEYER, DE HAINES, JR MCGRATH, RT TI ENGINEERING AND MATERIALS ISSUES IN DESIGNING A COLD-GAS DIVERTOR SO JOURNAL OF NUCLEAR MATERIALS LA English DT Article; Proceedings Paper CT 6th International Conference on Fusion Reactor Materials (ICFRM-6) CY SEP 27-OCT 01, 1993 CL STRESA, ITALY SP COMMISS EUROPEAN UNION, JOINT RES CTR, INST ADV MAT AB One of the key challenges facing the International Thermonuclear Experimental Reactor (ITER) Project is the development of plasma-facing components (PFCs) that can withstand the severe environmental conditions at the plasma edge. The most intensely loaded element of the PFCs is the divertor. The divertor must handle high fluxes of energetic plasma particles and electromagnetic radiation without excessive impurity buildup in the plasma core. The ''cold-plasma-target'' mode of divertor operation proposed for ITER expands the divertor design window to include several alternate heat sink and armor materials that were not available for the previous ''high recycling divertor'' approach. In particular, beryllium armor can now be considered with copper, niobium and vanadium heat sink materials; and helium or liquid metal coolants are feasible in addition to water. This paper presents material properties and compatability assessments for these materials and coolants along with parametric studies of thermal and mechanical performance. A viable design window is found for copper and niobium heat sinks with beryllium armor, but not for vanadium unless thin (similar to 1 mm) coolant structures can be accommodated mechanically. C1 OAK RIDGE NATL LAB, OAK RIDGE, TN 37831 USA. SANDIA NATL LABS, ALBUQUERQUE, NM USA. RP DAVIS, JW (reprint author), MCDONNELL DOUGLAS CORP, POB 516, ST LOUIS, MO 63166 USA. NR 4 TC 11 Z9 11 U1 0 U2 2 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0022-3115 J9 J NUCL MATER JI J. Nucl. Mater. PD SEP PY 1994 VL 212 BP 1353 EP 1359 DI 10.1016/0022-3115(94)91050-2 PN B PG 7 WC Materials Science, Multidisciplinary; Nuclear Science & Technology SC Materials Science; Nuclear Science & Technology GA PL245 UT WOS:A1994PL24500094 ER PT J AU ANDERL, RA PAWELKO, RJ HANKINS, MR LONGHURST, GR NEISER, RA AF ANDERL, RA PAWELKO, RJ HANKINS, MR LONGHURST, GR NEISER, RA TI HYDROGEN PERMEATION PROPERTIES OF PLASMA-SPRAYED TUNGSTEN SO JOURNAL OF NUCLEAR MATERIALS LA English DT Article; Proceedings Paper CT 6th International Conference on Fusion Reactor Materials (ICFRM-6) CY SEP 27-OCT 01, 1993 CL STRESA, ITALY SP COMMISS EUROPEAN UNION, JOINT RES CTR, INST ADV MAT AB Tungsten has been proposed as a plasma-facing component material for advanced fusion facilities. This paper reports on laboratory-scale studies that were done to assess the hydrogen permeation properties of plasma-sprayed tungsten for such applications. The work entailed deuterium permeation measurements for plasma-sprayed (PS) tungsten coatings, sputter-deposited (SP) tungsten coatings, and steel substrate material using a mass-analyzed, 3 keV D-3(+) ion beam with fluxes of similar to 6.5 x 10(19) D/m(2) s. Extensive characterization analyses for the plasma-sprayed tungsten coatings were made using Auger spectrometry and scanning electron microscopy (SEM). Observed permeation rates through composite PS-tungsten/steel specimens were several orders of magnitude below the permeation levels observed for SP-tungsten/steel composite specimens and pure steel specimens. Characterization analyses indicated that the plasma-sprayed tungsten coating had a nonhomogeneous microstructure that consisted of splats with columnar solidification, partially-melted particles with grain boundaries, and void regions. Reduced permeation levels can be attributed to the complex microstructure and a substantial surface-connected porosity. RP ANDERL, RA (reprint author), EG&G IDAHO INC, IDAHO NATL ENGN LAB, POB 1625, IDAHO FALLS, ID 83415 USA. NR 10 TC 10 Z9 10 U1 0 U2 0 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0022-3115 J9 J NUCL MATER JI J. Nucl. Mater. PD SEP PY 1994 VL 212 BP 1416 EP 1420 DI 10.1016/0022-3115(94)91061-8 PN B PG 5 WC Materials Science, Multidisciplinary; Nuclear Science & Technology SC Materials Science; Nuclear Science & Technology GA PL245 UT WOS:A1994PL24500105 ER PT J AU CAUSEY, RA WILSON, KL AF CAUSEY, RA WILSON, KL TI TRITIUM INVENTORY AND PERMEATION IN THE ITER BERYLLIUM SO JOURNAL OF NUCLEAR MATERIALS LA English DT Article; Proceedings Paper CT 6th International Conference on Fusion Reactor Materials (ICFRM-6) CY SEP 27-OCT 01, 1993 CL STRESA, ITALY SP COMMISS EUROPEAN UNION, JOINT RES CTR, INST ADV MAT ID DEUTERIUM; RELEASE AB Beryllium is presently selected for use in International Thermonuclear Experimental Reactor (ITER) as the primary plasma-facing material. The surface conditions of the beryllium as well as its tritium diffusion and solubility coefficients will determine the permeation rate of tritium to the coolant of ITER. The in-vessel tritium inventory will be affected by these coefficients and the neutron damage-induced trap density and energy. This paper presents the results of modeling of the permeation and inventory of tritium in the beryllium components of ITER. The DIFFUSE computer code was used for this modeling. Diffusivities, solubilities, surface conditions, trapping densities, and trapping energies were extracted from the most recent laboratory studies. The code predicted that the tritium inventory is a strong function of both the assumed surface recombination rate constant and the trap density. RP CAUSEY, RA (reprint author), SANDIA NATL LABS, LIVERMORE, CA 94550 USA. NR 14 TC 12 Z9 12 U1 0 U2 2 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0022-3115 J9 J NUCL MATER JI J. Nucl. Mater. PD SEP PY 1994 VL 212 BP 1436 EP 1442 DI 10.1016/0022-3115(94)91065-0 PN B PG 7 WC Materials Science, Multidisciplinary; Nuclear Science & Technology SC Materials Science; Nuclear Science & Technology GA PL245 UT WOS:A1994PL24500109 ER PT J AU NYGREN, RE WALKER, CA LUTZ, TJ HOSKING, FM MCGRATH, RT AF NYGREN, RE WALKER, CA LUTZ, TJ HOSKING, FM MCGRATH, RT TI BRAZING OF THE TORE SUPRA ACTIVELY-COOLED PHASE-III LIMITER SO JOURNAL OF NUCLEAR MATERIALS LA English DT Article; Proceedings Paper CT 6th International Conference on Fusion Reactor Materials (ICFRM-6) CY SEP 27-OCT 01, 1993 CL STRESA, ITALY SP COMMISS EUROPEAN UNION, JOINT RES CTR, INST ADV MAT AB The head of the water-cooled Tore Supra Phase III Limiter is a bank of 14 round OFHC copper tubes, curved to fit the plasma radius, onto which several hundred pyrolytic graphite (PG) tiles and a lesser number of carbon fiber composite tiles are brazed. The small allowable tolerances for fitting the tiles to the tubes and mating of compound curvatures made the brazing and fabrication extremely challenging. The paper describes the fabrication process with emphasis on the procedure for brazing. In the fixturing for vacuum furnace brazing, the tiles were each independently clamped to the tube with an elaborate set of ''window frame'' clamps. Braze quality was evaluated with transient heating tests. Some rebrazing was necessary. RP NYGREN, RE (reprint author), SANDIA NATL LABS, ALBUQUERQUE, NM 87185 USA. NR 4 TC 10 Z9 10 U1 0 U2 0 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0022-3115 J9 J NUCL MATER JI J. Nucl. Mater. PD SEP PY 1994 VL 212 BP 1621 EP 1626 DI 10.1016/0022-3115(94)91102-9 PN B PG 6 WC Materials Science, Multidisciplinary; Nuclear Science & Technology SC Materials Science; Nuclear Science & Technology GA PL245 UT WOS:A1994PL24500146 ER PT J AU HASSANEIN, A SMITH, D AF HASSANEIN, A SMITH, D TI ANALYSIS OF BEAM-ON-TARGET INTERACTION IN A NEUTRON-SOURCE TEST FACILITY SO JOURNAL OF NUCLEAR MATERIALS LA English DT Article; Proceedings Paper CT 6th International Conference on Fusion Reactor Materials (ICFRM-6) CY SEP 27-OCT 01, 1993 CL STRESA, ITALY SP COMMISS EUROPEAN UNION, JOINT RES CTR, INST ADV MAT ID IRRADIATION TEST FACILITY AB The need is urgent for a high-flux, high-energy neutron test facility to evaluate the performance of fusion reactor materials. An accelerator-based deuterium-lithium source is generally considered the most reasonable approach to a high-flux neutron source in the near future. The idea is to bombard a high-energy (20-40 MeV) deuteron beam into a lithium jet target to produce high-energy neutrons in order to simulate a fusion reactor environment via the Li (d, n) nuclear stripping reaction. Deposition of the high-energy deuteron beam and the subsequent response of the lithium jet are modeled and evaluated in detail. To assess the feasibility of this concept, the analysis is done parametrically for various deuteron beam energies, beam currents, and jet velocities. A main requirement for a successful operation is to keep the free jet surface at a minimum temperature to reduce surface evaporation of lithium into the vacuum system. The effects of neutron-generated heating and irradiation on the jet-supporting back plate are also evaluated. The back plate must maintain a reasonable lifetime during system operation. RP HASSANEIN, A (reprint author), ARGONNE NATL LAB, 9700 S CASS AVE, ARGONNE, IL 60439 USA. NR 9 TC 5 Z9 5 U1 0 U2 0 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0022-3115 J9 J NUCL MATER JI J. Nucl. Mater. PD SEP PY 1994 VL 212 BP 1671 EP 1677 DI 10.1016/0022-3115(94)91111-8 PN B PG 7 WC Materials Science, Multidisciplinary; Nuclear Science & Technology SC Materials Science; Nuclear Science & Technology GA PL245 UT WOS:A1994PL24500155 ER PT J AU WECHSLER, MS RAMAVARAPU, R DAUGHERTY, EL PALMER, RC BULLEN, DB SOMMER, WF AF WECHSLER, MS RAMAVARAPU, R DAUGHERTY, EL PALMER, RC BULLEN, DB SOMMER, WF TI CALCULATION OF DISPLACEMENT, GAS, AND TRANSMUTATION PRODUCTION IN STAINLESS-STEEL IRRADIATED WITH SPALLATION NEUTRONS SO JOURNAL OF NUCLEAR MATERIALS LA English DT Article; Proceedings Paper CT 6th International Conference on Fusion Reactor Materials (ICFRM-6) CY SEP 27-OCT 01, 1993 CL STRESA, ITALY SP COMMISS EUROPEAN UNION, JOINT RES CTR, INST ADV MAT AB Calculations using the high-energy transport code LAHET have been made for the production of displacements, helium gas, and transmuted atoms for stainless steel (Fe-18 wt% Cr-10 wt% Ni) irradiated with spallation neutrons at energies of 100 to 1600 MeV. The damage energy cross section increased from about 250 to 350 b keV for increasing neutron energies from 100 to 1600 MeV with a spallation spectrum average of 281 b keV. For a displacement threshold energy of 33 eV, the corresponding spectrum-average displacement cross section is 3400 b. The PKA spectrum was found to be fairly independent of the incident neutron energy, with an average damage energy of 0.25-0.30 MeV. The helium production cross section increased monotonically with increasing neutron energy, with a spectrum average of 0.32 b. The maximum transmutation yield was observed near manganese (Z = 25), corresponding to a production cross section of about 0.2 b. Relevance to fusion materials is discussed. C1 IOWA STATE UNIV SCI & TECHNOL, AMES, IA 50011 USA. LOS ALAMOS NATL LAB, LOS ALAMOS, NM 87545 USA. NR 15 TC 3 Z9 3 U1 1 U2 3 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0022-3115 J9 J NUCL MATER JI J. Nucl. Mater. PD SEP PY 1994 VL 212 BP 1678 EP 1681 DI 10.1016/0022-3115(94)91112-6 PN B PG 4 WC Materials Science, Multidisciplinary; Nuclear Science & Technology SC Materials Science; Nuclear Science & Technology GA PL245 UT WOS:A1994PL24500156 ER PT J AU WANG, GJ VOLKOW, ND WOLF, AP BRODIE, JD HITZEMANN, RJ AF WANG, GJ VOLKOW, ND WOLF, AP BRODIE, JD HITZEMANN, RJ TI INTERSUBJECT VARIABILITY OF BRAIN GLUCOSE METABOLIC MEASUREMENTS IN YOUNG NORMAL MALES SO JOURNAL OF NUCLEAR MEDICINE LA English DT Review DE CEREBRAL GLUCOSE METABOLISM; INTERSUBJECT VIABILITY; PET ID POSITRON EMISSION TOMOGRAPHY; CEREBRAL BLOOD-FLOW; PROGRESSIVE SUPRANUCLEAR PALSY; OBSESSIVE-COMPULSIVE DISORDER; MULTI-INFARCT DEMENTIA; ALZHEIMERS-DISEASE; RATE CONSTANTS; COMPUTED-TOMOGRAPHY; MAGNETIC-RESONANCE; F-18 2-FLUORO-2-DEOXY-D-GLUCOSE AB This study evaluates intersubject variability on regional glucose metabolic values in a group of 50 healthy right-handed males between 20 and 40 yr of age. Methods: Brain glucose metabolism was measured using PET and 2-deoxy-2[F-18]fluoro-D-glucose under resting conditions and was separately assessed for subjects in their twenties (n = 34) and those in their thirties (n = 16). Results: Regional brain metabolic values showed significant intersubject variability with coefficients of variation (CV) that ranged between 11.1% to 15.2% (twenties) and 7.2% to 12.6% (thirties). Relative measures (regional/global) were less variable than absolute measures and the CV ranged between 4.1% to 8.3% (twenties) and 3.9% to 10% (thirties). Whereas global brain metabolic rate for subjects in their twenties was not significantly different from that of subjects in their thirties, the metabolic rate in left frontal regions was significantly lower in the older subjects. Conclusion: The correlations between age and absolute and relative metabolism in the left frontal region were r = 0.438, p < 0.002 and r = 0.447, p < 0.001, respectively. This study shows significant intersubject variability for regional brain metabolic values in normal controls and documents age-related decreases in frontal metabolism that occur even in relatively young adults. C1 BROOKHAVEN NATL LAB, DEPT CHEM, UPTON, NY 11973 USA. SUNY STONY BROOK, DEPT RADIOL, STONY BROOK, NY USA. SUNY STONY BROOK, DEPT PSYCHIAT, STONY BROOK, NY 11794 USA. NYU, MED CTR, DEPT PSYCHIAT, NEW YORK, NY 10016 USA. RP BROOKHAVEN NATL LAB, DEPT MED, UPTON, NY 11973 USA. FU NIDA NIH HHS [NIDA R01-DA06891]; NIMH NIH HHS [NIMH MH 47277] NR 116 TC 77 Z9 79 U1 0 U2 3 PU SOC NUCLEAR MEDICINE INC PI RESTON PA 1850 SAMUEL MORSE DR, RESTON, VA 20190-5316 USA SN 0161-5505 EI 1535-5667 J9 J NUCL MED JI J. Nucl. Med. PD SEP PY 1994 VL 35 IS 9 BP 1457 EP 1466 PG 10 WC Radiology, Nuclear Medicine & Medical Imaging SC Radiology, Nuclear Medicine & Medical Imaging GA PE096 UT WOS:A1994PE09600012 PM 8071692 ER PT J AU DONGARRA, JJ VANDEGEIJN, RA WALKER, DW AF DONGARRA, JJ VANDEGEIJN, RA WALKER, DW TI SCALABILITY ISSUES AFFECTING THE DESIGN OF A DENSE LINEAR ALGEBRA LIBRARY SO JOURNAL OF PARALLEL AND DISTRIBUTED COMPUTING LA English DT Article ID MEMORY AB This paper discusses the scalability of Cholesky, LU, and QR factorization routines on MIMD distributed memory concurrent computers. These routines form part of the ScaLAPACK mathematical software library that extends the widely used LAPACK library to run efficiently on scalable concurrent computers. To ensure good scalability and performance, the ScaLAPACK routines are based on block-partitioned algorithms that reduce the frequency of data movement between different levels of the memory hierarchy, and particularly between processors. The block cyclic data distribution, that is used in all three factorization algorithms, is described. An outline of the sequential and parallel block-partitioned algorithms is given. Approximate models of algorithms' performance are presented to indicate which factors in the design of the algorithm have an impact upon scalability. These models are compared with timings results on a 128-node Intel iPSC/860 hypercube. It is shown that the routines are highly scalable on this machine for problems that occupy more than about 25% of the memory on each processor, and that the measured timings are consistent with the performance model. The contribution of this paper goes beyond reporting our experience: our implementations are available in the public domain. (C) 1994 Academic Press, Inc. C1 OAK RIDGE NATL LAB,MATH SCI SECT,OAK RIDGE,TN 37831. UNIV TEXAS,DEPT COMP SCI,AUSTIN,TX 78712. RP DONGARRA, JJ (reprint author), UNIV TENNESSEE,DEPT COMP SCI,107 AYRES HALL,KNOXVILLE,TN 37996, USA. RI Walker, David/B-7978-2010; Dongarra, Jack/E-3987-2014; OI Walker, David/0000-0002-1360-6330 NR 51 TC 30 Z9 31 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 0743-7315 J9 J PARALLEL DISTR COM JI J. Parallel Distrib. Comput. PD SEP PY 1994 VL 22 IS 3 BP 523 EP 537 DI 10.1006/jpdc.1994.1108 PG 15 WC Computer Science, Theory & Methods SC Computer Science GA PG306 UT WOS:A1994PG30600011 ER PT J AU MATHIS, CA TAYLOR, SE ENAS, JD AKGUN, E AF MATHIS, CA TAYLOR, SE ENAS, JD AKGUN, E TI BINDING POTENCY OF 6-NITROQUIPAZINE ANALOGS FOR THE 5-HYDROXYTRYPTAMINE REUPTAKE COMPLEX SO JOURNAL OF PHARMACY AND PHARMACOLOGY LA English DT Article ID POSITRON EMISSION TOMOGRAPHY; SEROTONIN UPTAKE SITES; H-3 PAROXETINE BINDING; PARKINSONS-DISEASE; HUMAN-BRAIN; RAT-BRAIN; I-125 5-IODO-6-NITROQUIPAZINE; COMPUTED-TOMOGRAPHY; IMIPRAMINE BINDING; SELECTIVE LIGAND AB The in-vitro inhibition constants (K-i) of nine structural analogues of the potent 5-hydroxytryptamine (5-HT)-uptake inhibitor, 6-nitroquipazine, were determined to assess the structure-affinity relationship of these derivatives. The goal of these studies was to determine those positions on 6-nitroquipazine that could be derivatized without significantly decreasing the affinity of the drug for the binding site, so that radiolabels such as I-123, Br-76 or F-18 might be appended for in-vivo imaging studies of the 5-HT reuptake system. Using bromine as a steric probe, the rank order of potency of bromine-substituted 6-nitroquipazine analogues for inhibiting the binding of [H-3]paroxetine to the 5-HT reuptake binding site was: 8-<3-<7-<4-<5-bromo. The in-vitro equipotent molar ratio (EPMR, K-i (analogue)/K-i(6-nitroquipazine)) of the 5-bromo analogue was 0.57, indicating that this analogue had greater affinity for the 5-HT reuptake complex than 6-nitroquipazine. Derivatization at the 5-position with fluorine and iodine also resulted in potent compounds with EPMR values of 1.1 and 0.83, respectively. Substitution of quipazine with bromo, cyano, and formyl groups at the 6-position produced less potent compounds than the 6-nitro group. Based upon the high affinities of the 5-bromo-, 5-fluoro- and 5-iodo-6-nitroquipazines for the 5-HT reuptake complex, these compounds are candidates for radiolabelling for in-vivo studies of the 5-HT reuptake site. C1 UNIV PITTSBURGH,DEPT RADIOL,PITTSBURGH,PA 15213. UNIV PITTSBURGH,DEPT PHARMACEUT SCI,PITTSBURGH,PA 15213. UNIV CALIF BERKELEY,LAWRENCE BERKELEY LAB,CTR FUNCT IMAGING,BERKELEY,CA 94720. RI Mathis, Chester/A-8607-2009 FU NINDS NIH HHS [NS-22899] NR 28 TC 15 Z9 15 U1 0 U2 0 PU ROYAL PHARMACEUTICAL SOC GREAT BRITAIN PI LONDON PA 1 LAMBETH HIGH ST, LONDON, ENGLAND SE1 7JN SN 0022-3573 J9 J PHARM PHARMACOL JI J. Pharm. Pharmacol. PD SEP PY 1994 VL 46 IS 9 BP 751 EP 754 PG 4 WC Pharmacology & Pharmacy SC Pharmacology & Pharmacy GA PH515 UT WOS:A1994PH51500012 PM 7837045 ER PT J AU LEE, MA WINTER, NW CASEY, WH AF LEE, MA WINTER, NW CASEY, WH TI INVESTIGATION OF THE LIGAND-EXCHANGE REACTION FOR THE AQUEOUS BE2+ ION SO JOURNAL OF PHYSICAL CHEMISTRY LA English DT Article ID ELECTROSTATIC POTENTIALS; FREE-ENERGIES; SOLVATION; WATER; ABINITIO; MODEL; CONTINUUM; BERYLLIUM; FIELD AB The geometry and energy of the transition state for the exchange of water-coordinating Be2+ in aqueous solution has been investigated by Hartree-Fock (HF) cluster calculations, which include the ion and its near-neighbors. The calculated activation parameters, Delta V* and Delta H*, are compared to the spectroscopic values. The HF activation volume Delta V* was found to be similar to 0 compared to the experimental value of -13.6 cm(3)/mol. The discrepancy is attributed to an incomplete description of the second coordination shell, which is needed to accurately define the volume of the transition-state complex. Including a continuum approximation for the solvent did not improve the agreement. The HF activation enthalpy for the exchange reaction, 0.65 eV, is in good agreement with the experimentally determined value of 0.61 eV. A qualitative description of the reaction mechanism has been developed from calculations on 5-fold coordinated Be2+ with one Be-OH2 distance constrained to the reaction coordinate. The results suggest a reaction scheme where the exchanging water from the second coordination shell is oriented along a 2-fold axis of the tetramer. Optimization of the complex at the saddle point of the reaction surface resulted in a C-2v transition state with approximate trigonal-bipyramidal geometry. The Be-H2O bonding is dominated by electrostatic interactions with little evidence of dative or covalent bonding between the water lone pairs and the empty 2s and 2p orbitals on Be2+. C1 LAWRENCE LIVERMORE NATL LAB,STRUCT BIOL GRP,LIVERMORE,CA 94550. UNIV CALIF DAVIS,DEPT CHEM,DAVIS,CA 95616. UNIV CALIF DAVIS,DEPT LAND AIR & WATER RESOURCES,DAVIS,CA 95616. NR 30 TC 31 Z9 33 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 SEP 1 PY 1994 VL 98 IS 35 BP 8641 EP 8647 DI 10.1021/j100086a010 PG 7 WC Chemistry, Physical SC Chemistry GA PE359 UT WOS:A1994PE35900010 ER PT J AU HUNG, CT YANG, SN LEE, TSH AF HUNG, CT YANG, SN LEE, TSH TI A RELATIVISTIC MESON-EXCHANGE MODEL OF PION-NUCLEON SCATTERING SO JOURNAL OF PHYSICS G-NUCLEAR AND PARTICLE PHYSICS LA English DT Note ID PHOTOPRODUCTION AB Pion-nucleon scattering is investigated using the Kadyshevsky three-dimensional reduction of the Bethe-Salpeter equation. The resulting potential includes the direct and crossed N, Delta terms, and the t-channel sigma- and rho-exchange terms. The nucleon pole condition is imposed to define the renormalization of the nucleon mass and the pi NN coupling constant. A mixture of the scalar and vector sigma pi pi couplings is introduced to simulate the effect of the broad width of the s-wave correlated two-pion exchange mechanism. Good descriptions of the pi N phase shifts up to 400 MeV have been obtained in all S- and P-waves. The off-shell behaviours for our model differ significantly from those obtained using different reduction schemes. C1 ARGONNE NATL LAB,DIV PHYS,ARGONNE,IL 60439. RP HUNG, CT (reprint author), NATL TAIWAN UNIV,DEPT PHYS,TAIPEI 10764,TAIWAN. NR 21 TC 32 Z9 32 U1 0 U2 1 PU IOP PUBLISHING LTD PI BRISTOL PA TECHNO HOUSE, REDCLIFFE WAY, BRISTOL, ENGLAND BS1 6NX SN 0954-3899 J9 J PHYS G NUCL PARTIC JI J. Phys. G-Nucl. Part. Phys. PD SEP PY 1994 VL 20 IS 9 BP 1531 EP 1536 DI 10.1088/0954-3899/20/9/021 PG 6 WC Physics, Nuclear; Physics, Particles & Fields SC Physics GA PF549 UT WOS:A1994PF54900021 ER PT J AU PEILERT, G SANGSTER, TC NAMBOODIRI, MN BRITT, HC AF PEILERT, G SANGSTER, TC NAMBOODIRI, MN BRITT, HC TI THE MULTIFRAGMENTATION FREEZE-OUT VOLUME IN HEAVY-ION COLLISIONS SO JOURNAL OF PHYSICS G-NUCLEAR AND PARTICLE PHYSICS LA English DT Letter ID MASS FRAGMENT EMISSION; INTRANUCLEAR CASCADE CALCULATION; SUBTHRESHOLD PION-PRODUCTION; STATISTICAL MULTIFRAGMENTATION; NUCLEAR COLLISIONS; HADRONIC MATTER; SOURCE LIFETIME; BREAK-UP; MODEL; TEMPERATURE AB Reduced velocity correlation functions for fragments from the reaction Fe+Au at 100 A MeV bombarding energy are investigated using the dynamical-statistical approach QMD+SMM. It is shown that such a two-step model can consistently explain the data if a simultaneous multifragmentation with a freeze-out volume corresponding to 0.1-0.3 times normal nuclear matter density is used. The calculations show an additional correlation due to recoil effects from a third heavy fragment in an asymmetric break-up. This effect is present, but less pronounced in the data. RP PEILERT, G (reprint author), LAWRENCE LIVERMORE NATL LAB,LIVERMORE,CA 94550, USA. NR 41 TC 2 Z9 2 U1 0 U2 1 PU IOP PUBLISHING LTD PI BRISTOL PA TECHNO HOUSE, REDCLIFFE WAY, BRISTOL, ENGLAND BS1 6NX SN 0954-3899 J9 J PHYS G NUCL PARTIC JI J. Phys. G-Nucl. Part. Phys. PD SEP PY 1994 VL 20 IS 9 BP L105 EP L110 DI 10.1088/0954-3899/20/9/003 PG 6 WC Physics, Nuclear; Physics, Particles & Fields SC Physics GA PF549 UT WOS:A1994PF54900003 ER PT J AU ERDMANN, K CZERWINSKI, W GERSTEIN, BC PRUSKI, M AF ERDMANN, K CZERWINSKI, W GERSTEIN, BC PRUSKI, M TI STRUCTURAL STUDIES OF POLY(PARA-PHENYLENE), POLY(2,5-THIENYLENE) AND THEIR DERIVATIVES BY SOLID-STATE NMR OF H-1 AND C-13 SO JOURNAL OF POLYMER SCIENCE PART B-POLYMER PHYSICS LA English DT Article DE STRUCTURAL STUDIES; NMR; CONJUGATED POLYMERS ID NUCLEAR MAGNETIC-RESONANCE; COPOLYMERS; POLYMERS; COMPATIBILITY; SPECTROSCOPY; THIOPHENE; BLENDS AB Transient techniques in NMR of H-1 and C-13 were used to study the chemical and physical structures of solid poly(p-phenylene) (PPP), poly(2,6-dimethyl-p-phenylene oxide) (PDMPO), poly(p-phenylene sulfide) (PPS), poly(p-biphenylene sulfide) (PPBS), poly(p-phenylene selenide) (PPSe), poly(p-biphenylene selenide) (PPBSe), poly(2,5-thienylene) (PT), poly (3-methyl-2,5-thienylene) (PMT), and poly (p-phenylene-co-2,5-thienylene) (PPPT) of different monomer ratios. C-13 NMR confirmed the expected chemical structure for homopolymers, and indicated a random distribution of monomer units in PPPT. Relative fractions of crystalline and interfacial regions were determined by measurements of H-1 magnetic relaxation, C-13 CP/MAS NMR, and XRD. (c) 1994 John Wiley & Sons, Inc. C1 NICHOLAS COPERNICUS UNIV,PL-87100 TORUN,POLAND. IOWA STATE UNIV SCI & TECHNOL,AMES LAB,AMES,IA 50011. IOWA STATE UNIV SCI & TECHNOL,DEPT CHEM,AMES,IA 50011. NR 21 TC 6 Z9 6 U1 0 U2 4 PU JOHN WILEY & SONS INC PI NEW YORK PA 605 THIRD AVE, NEW YORK, NY 10158-0012 SN 0887-6266 J9 J POLYM SCI POL PHYS JI J. Polym. Sci. Pt. B-Polym. Phys. PD SEP PY 1994 VL 32 IS 12 BP 1961 EP 1968 DI 10.1002/polb.1994.090321202 PG 8 WC Polymer Science SC Polymer Science GA PC785 UT WOS:A1994PC78500002 ER PT J AU HOCHSTEIN, JI AYDELOTT, JC MJOLSNESS, RC TORREY, MD AF HOCHSTEIN, JI AYDELOTT, JC MJOLSNESS, RC TORREY, MD TI ON-ORBIT PROPELLANT MOTION RESULTING FROM AN IMPULSIVE ACCELERATION SO JOURNAL OF PROPULSION AND POWER LA English DT Article AB In-space docking and separation maneuvers of spacecraft that have large fluid mass fractions may cause undesirable spacecraft motion in response to the impulsive-acceleration-induced fluid motion. An example of this potential low-gravity fluid management problem arose during the development of the shuttle/Centaur vehicle. Experimentally verified numerical modeling techniques were developed to establish the propellant dynamics, and subsequent vehicle motion, associated with the separation of the Centaur vehicle from the shuttle cargo bay. Although the shuttle/Centaur development activity has been suspended, the numerical modeling techniques are available to predict on-orbit liquid motion resulting from impulsive accelerations for other missions and spacecraft. C1 NASA,LEWIS RES CTR,CYROGEN FLUIDS TECHNOL OFF,CLEVELAND,OH 44135. LOS ALAMOS NATL LAB,FLUID DYNAM GRP T3,LOS ALAMOS,NM 87545. RP HOCHSTEIN, JI (reprint author), MEMPHIS STATE UNIV,MEMPHIS,TN 38152, USA. NR 9 TC 0 Z9 0 U1 0 U2 2 PU AMER INST AERONAUT ASTRONAUT PI RESTON PA 1801 ALEXANDER BELL DRIVE, STE 500, RESTON, VA 22091 SN 0748-4658 J9 J PROPUL POWER JI J. Propul. Power PD SEP-OCT PY 1994 VL 10 IS 5 BP 653 EP 660 DI 10.2514/3.23776 PG 8 WC Engineering, Aerospace SC Engineering GA PG536 UT WOS:A1994PG53600009 ER PT J AU MERCURIO, D CHAMPAMAUDMESJARD, JC FRIT, B CONFLANT, P BOIVIN, JC VOGT, T AF MERCURIO, D CHAMPAMAUDMESJARD, JC FRIT, B CONFLANT, P BOIVIN, JC VOGT, T TI THERMAL EVOLUTION OF THE CRYSTAL-STRUCTURE OF THE RHOMBOHEDRAL BI0.75SR0.25O1.375 PHASE - A SINGLE-CRYSTAL NEUTRON-DIFFRACTION STUDY SO JOURNAL OF SOLID STATE CHEMISTRY LA English DT Article ID SINTERED OXIDES; SYSTEM; CONDUCTION AB The crystal structure of the rhombohedral (R(3)(-)m) Bi-0.75 Sr0.25O1.375 phase has been determined at room and high temperature using single crystal neutron diffraction. It can be described at all temperatures as the regular repetition of three fluorite-like sheets shifted with respect to one another by a vector mu = 2 (a/3 + b/3 + c/3) and thus separated by an intersheet space free of anions. Interstitial anions partially occupy delocalized sites in the vicinity of the unsubstituted interface Bi-layers and are responsible for the high ionic conductivity of this phase. They are mainly located on the fluorite-like sheet side of this Bi-layer at room temperature. At high temperature, they partly migrate to the opposite side, i.e., the intersheet side, a phenomenon which results in the beta(2) double right arrow beta(1) transition and a sudden increase of the conductivity. In light of these and previous results the different behavior of various alkaline earth-doped rhombohedral phases (Ca, Sr, Ba) and of the La-doped homologue is analyzed and rationalized. (C) 1994 Academic Press, Inc. C1 FAC SCI LIMOGES,MAT CERAM & TRAITEMENTS SURFACE LAB,CNRS,URA 320,F-87060 LIMOGES,FRANCE. UNIV LILLE 1,ENSCL,EQUIPE CRISTALLOCHIM & PHYSICOCHIM SOLIDE,CNRS,URA 452,F-59652 VILLENEUVE DASCQ,FRANCE. BROOKHAVEN NATL LAB,DEPT PHYS,UPTON,NY 11973. RI Vogt, Thomas /A-1562-2011 OI Vogt, Thomas /0000-0002-4731-2787 NR 20 TC 39 Z9 39 U1 0 U2 7 PU ACADEMIC PRESS INC JNL-COMP SUBSCRIPTIONS PI SAN DIEGO PA 525 B ST, STE 1900, SAN DIEGO, CA 92101-4495 SN 0022-4596 J9 J SOLID STATE CHEM JI J. Solid State Chem. PD SEP PY 1994 VL 112 IS 1 BP 1 EP 8 DI 10.1006/jssc.1994.1255 PG 8 WC Chemistry, Inorganic & Nuclear; Chemistry, Physical SC Chemistry GA PG305 UT WOS:A1994PG30500001 ER PT J AU HINATSU, Y EDELSTEIN, N AF HINATSU, Y EDELSTEIN, N TI ELECTRON-PARAMAGNETIC-RESONANCE SPECTRUM OF PR4+ IN BACEO3 SO JOURNAL OF SOLID STATE CHEMISTRY LA English DT Article ID MAGNETIC-SUSCEPTIBILITY; BAPRO3 AB The electron paramagnetic resonance spectrum of a powder of Pr4+ in BaCeO3 was measured at 8.5 K. A very large hyperfine interaction with the Pr-141 nucleus was observed. In addition to the allowed hyperfine transitions, forbidden hyperfine transitions were observed. The results were analyzed based on the weak field approximation, i.e., Breit-Rabi formula, and the g value, \g\ 0.745(1) and the hyperfine coupling constant, \A\ = 0.0606(2) cm(-1), were obtained. From the measured g value, the Gamma(7) --> Gamma(8) crystal field transition for BaPrO3 obtained from an earlier inelastic neutron scattering experiment, and setting the spin-orbit coupling constant to its free ion value zeta = 865 cm(-1), the energy levels of pr(4+) in BaCeO3 were calculated. The measured magnetic susceptibility of BaPrO3 was compared to the values calculated with the above model. (C) 1994 Academic Press, Inc. C1 UNIV CALIF BERKELEY,DIV CHEM SCI,LAWRENCE BERKELEY LAB,BERKELEY,CA 94720. RP HINATSU, Y (reprint author), JAPAN ATOM ENERGY RES INST,DEPT CHEM,TOKAI,IBARAKI 31911,JAPAN. NR 17 TC 33 Z9 33 U1 1 U2 3 PU ACADEMIC PRESS INC JNL-COMP SUBSCRIPTIONS PI SAN DIEGO PA 525 B ST, STE 1900, SAN DIEGO, CA 92101-4495 SN 0022-4596 J9 J SOLID STATE CHEM JI J. Solid State Chem. PD SEP PY 1994 VL 112 IS 1 BP 53 EP 57 DI 10.1006/jssc.1994.1263 PG 5 WC Chemistry, Inorganic & Nuclear; Chemistry, Physical SC Chemistry GA PG305 UT WOS:A1994PG30500009 ER PT J AU HO, PC PALMER, DA MESMER, RE AF HO, PC PALMER, DA MESMER, RE TI ELECTRICAL-CONDUCTIVITY MEASUREMENTS OF AQUEOUS SODIUM-CHLORIDE SOLUTIONS TO 600-DEGREES-C AND 300-MPA SO JOURNAL OF SOLUTION CHEMISTRY LA English DT Article DE CONDUCTIVITY; AQUEOUS; SODIUM CHLORIDE; PRESSURE; ION ASSOCIATION; TEMPERATURE ID THERMODYNAMIC PROPERTIES; 4000 BARS; IONIZATION-CONSTANTS; PRESSURES; TEMPERATURES; CONDUCTANCES; WATER; STEAM AB Electrical conductance measurements of dilute (< 0.1 mol-kg(-1)) aqueous NaCl solutions were made primarily to quantify the degree of ion association which increases with increasing temperature and decreasing solvent density. These measurements were carried our at temperatures from 100 to 600 degrees C and pressures up to 300 MPa with a modified version of the apparatus used previously in the high temperature study in this laboratory. Particular emphasis was placed on conditions close to the critical temperature/pressure region of water, i.e., at 5 degrees intervals from 370 to 400 degrees C. The results verify previous findings that the limiting equivalent conductance Lambda(0) of NaCl increases linearly with decreasing density from 0.75 to 0.3 g-cm(-1) and also with increasing temperature from 100 to 350 degrees C. Above 350 degrees C, Lambda(0), is virtually temperature independent. The logarithm of the molal association constant as calculated exclusively from the data greater than or equal to 400 degrees C is represented as a function of temperature (Kelvin) and the logarithm of the density of water (g-cm-(-3)) as follows: log K-m = 0.997 - 650.07/T - (10.420 - 2600.5/T)log rho(W) Note that this function also provides a good representation of the log K-m values obtained from 350 to 395 degrees C at densities greaser than ca. 0.6 g-cm(-3). More precise conductance data now available in the literature suggest a systematic error of unknown origin may exist in the data obtained at lower densities in this region. The relevant thermodynamics quantities derived from differentiation of this equation with respect to temperature and pressure are listed in the text. RP HO, PC (reprint author), OAK RIDGE NATL LAB,DIV CHEM & ANALYT SCI,POB 2008,OAK RIDGE,TN 37831, USA. NR 25 TC 109 Z9 110 U1 1 U2 15 PU PLENUM PUBL CORP PI NEW YORK PA 233 SPRING ST, NEW YORK, NY 10013 SN 0095-9782 J9 J SOLUTION CHEM JI J. Solut. Chem. PD SEP PY 1994 VL 23 IS 9 BP 997 EP 1018 DI 10.1007/BF00974100 PG 22 WC Chemistry, Physical SC Chemistry GA PL521 UT WOS:A1994PL52100004 ER PT J AU LAFARGE, RA BATY, RS AF LAFARGE, RA BATY, RS TI FUNCTIONAL DEPENDENCE OF TRAJECTORY DISPERSION ON INITIAL CONDITION ERRORS SO JOURNAL OF SPACECRAFT AND ROCKETS LA English DT Article AB This article proposes numerical techniques to approximate dispersion bounds and burst patterns for Monte Carlo trajectory simulations. The algorithms developed approximate trajectory dispersion bounds and burst patterns caused by the errors in initial conditions in 1/100th of the computational expense of full Monte Carlo analyses. The proposed techniques are based on the properties that the six-degree-of-freedom equations of motion produce solutions that vary continuously with initial conditions and preserve the statistical distribution of the initial conditions. The continuity of solutions in initial conditions is studied numerically by performing a stability analysis. Numerical experiments simulating a fuse effectiveness study for two generic re-entry bodies are exhibited. The dispersion bounds and burst patterns predicted using the proposed algorithms are compared to tile dispersion bounds and burst patterns predicted using full Monte Carlo simulations. The agreement is excellent. C1 SANDIA NATL LABS,DEPT AEROSCI & FLUID DYNAM,TECH STAFF,ALBUQUERQUE,NM 87185. RP LAFARGE, RA (reprint author), SANDIA NATL LABS,DEPT INTELLIGENT SYST PRINCIPLES,TECH STAFF,ALBUQUERQUE,NM 87185, USA. NR 13 TC 2 Z9 2 U1 0 U2 0 PU AMER INST AERONAUT ASTRONAUT PI RESTON PA 1801 ALEXANDER BELL DRIVE, STE 500, RESTON, VA 22091 SN 0022-4650 J9 J SPACECRAFT ROCKETS JI J. Spacecr. Rockets PD SEP-OCT PY 1994 VL 31 IS 5 BP 806 EP 813 DI 10.2514/3.26516 PG 8 WC Engineering, Aerospace SC Engineering GA QA684 UT WOS:A1994QA68400014 ER PT J AU QUIRAM, DJ OCONNELL, JP COCHRAN, HD AF QUIRAM, DJ OCONNELL, JP COCHRAN, HD TI THE SOLUBILITY OF SOLIDS IN COMPRESSED GASES SO JOURNAL OF SUPERCRITICAL FLUIDS LA English DT Article DE SOLID SOLUBILITY; NEAR-CRITICAL CO2; ENTRAINERS; VIRIAL EQUATION ID FLUID CARBON-DIOXIDE; SUPERCRITICAL FLUIDS; CO2; EQUILIBRIA; MIXTURES; SOLVENTS AB The density series virial equation of state truncated at the third virial coefficient has been evaluated for describing the fluid nonideality of systems of pure solids in equilibrium with near-critical CO2 including systems with cosolvents. The function [In (z phi(1))]/rho is found to be linear with rho for pressures up to 400 bar for 16 solutes, eleven of which also involved 8 different cosolvents for temperatures from 300 to 523 K. As required, when the virial series is applicable, the zero-density intercepts obtained from high-pressure data agree with those from low-pressure data. The method shows how cosolvent contributions via composition and density can be explicitly separated. Prediction of second cross virial coefficients along with fitting the third virial to a single data point on the isotherm can be at least as successful as other models. Sensitivity to variations in sublimation pressure, solid molar volume, and fluid density has been tested. C1 UNIV VIRGINIA,DEPT CHEM ENGN,CHARLOTTESVILLE,VA 22903. OAK RIDGE NATL LAB,OAK RIDGE,TN 37831. NR 30 TC 11 Z9 12 U1 1 U2 2 PU PRA PRESS PI CINCINNATI PA POLYMER RES ASSOC INC 9200 MONTGOMERY RD, SUITE 23B, CINCINNATI, OH 45242 SN 0896-8446 J9 J SUPERCRIT FLUID JI J. Supercrit. Fluids PD SEP PY 1994 VL 7 IS 3 BP 159 EP 164 DI 10.1016/0896-8446(94)90020-5 PG 6 WC Chemistry, Physical; Engineering, Chemical SC Chemistry; Engineering GA PW609 UT WOS:A1994PW60900002 ER PT J AU SCHREMS, KK AF SCHREMS, KK TI WEAR-RELATED FATIGUE IN A WIRE ROPE FAILURE SO JOURNAL OF TESTING AND EVALUATION LA English DT Article DE ROPE; WEAR; CONTACT STRESS; FATIGUE; FRACTOGRAPHY; CRACK INITIATION; STRESS; POINT CONTACT; LINE CONTACT AB The fatigue failure of a nonrotating wire rope used on a skip hoist in an underground mine has been studied as part of the ongoing research by the U.S. Bureau of Mines into haulage and materials handling hazards in mines. Correlation of individual wire failures within two segments of the failed rope were used to gain an understanding of the progression of degradation leading to rope failure. Wire failures occurred predominantly at locations of wear between adjacent strands. These interstrand wear sites are identifiable by a large reduction in diameter; however, reduction in area is not responsible for the location of failure. Fractography revealed crack initiation sites to be located opposite the characteristic wear site or at other less noticeable wear sites. The primary failure mechanism of individual wires within the rope is believed to be a function of contact stress at the interstrand wear sites. Axially loading and unloading the rope produces high compressive stresses at the contact sites, which in turn produce large alternating tensile stresses on the opposite side of the wire. This mechanism has been termed ''contact stress-accelerated fatigue.'' This mechanism and the affiliated wear pattern both are consequences of interstrand contact RP SCHREMS, KK (reprint author), US BUR MINES,ALBANY RES CTR,ALBANY,OR 97321, USA. NR 20 TC 14 Z9 15 U1 0 U2 2 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 SEP PY 1994 VL 22 IS 5 BP 490 EP 499 PG 10 WC Materials Science, Characterization & Testing SC Materials Science GA PJ305 UT WOS:A1994PJ30500015 ER PT J AU WATSON, JG MCMANUS, T EKLUND, G VIGON, B ITALIANO, M FRANKLIN, W GREEN, AES GREEN, S HARPER, G KEOLEIAN, G AF WATSON, JG MCMANUS, T EKLUND, G VIGON, B ITALIANO, M FRANKLIN, W GREEN, AES GREEN, S HARPER, G KEOLEIAN, G TI SUSTAINABLE DEVELOPMENT BY DESIGN - REVIEW OF LIFE-CYCLE DESIGN AND RELATED APPROACHES SO JOURNAL OF THE AIR & WASTE MANAGEMENT ASSOCIATION LA English DT Discussion C1 INTEL CORP,CHANDLER,AZ 85226. RADIAN CORP,AUSTIN,TX 78720. BATTELLE MEM INST,COLUMBUS,OH 43201. GARDNER CARBON & DOUGLAS,WASHINGTON,DC 20005. FRANKLIN ASSOCIATES LTD,PRAIRIE VILLAGE,KS 66208. UNIV FLORIDA,GAINESVILLE,FL 32611. OAK RIDGE NATL LAB,OAK RIDGE,TN. UNIV MICHIGAN,SCH NAT RESOURCES & ENVIRONM,NATL POLLUT PREVENT CTR,ANN ARBOR,MI 48109. RP WATSON, JG (reprint author), DESERT RES INST,POB 60220,RENO,NV 89506, USA. RI Watson, John/E-6869-2010 OI Watson, John/0000-0002-1752-6899 NR 1 TC 3 Z9 3 U1 0 U2 2 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 SEP PY 1994 VL 44 IS 9 BP 1083 EP 1088 PG 6 WC Engineering, Environmental; Environmental Sciences; Meteorology & Atmospheric Sciences SC Engineering; Environmental Sciences & Ecology; Meteorology & Atmospheric Sciences GA PJ502 UT WOS:A1994PJ50200002 ER PT J AU LAWSON, DD MOORE, DH SCHNEIDER, JS SAGEBIEL, RW AF LAWSON, DD MOORE, DH SCHNEIDER, JS SAGEBIEL, RW TI NEVUS COUNTING AS A RISK FACTOR FOR MELANOMA - COMPARISON OF SELF-COUNT WITH COUNT BY PHYSICIAN SO JOURNAL OF THE AMERICAN ACADEMY OF DERMATOLOGY LA English DT Article ID CUTANEOUS MALIGNANT-MELANOMA; MELANOCYTIC NEVI; DYSPLASTIC NEVI; PIGMENTED MOLES; POPULATION; NAEVI; NUMBER; EXPOSURE; COMMON; WOMEN AB Background: The number of total body nevi is a major risk marker for malignant melanoma. No previous study has evaluated the accuracy of whole body large nevus (greater than or equal to 5 mm) self-counts. Objective: Our purpose was to evaluate the accuracy of large nevus self-counts by sex, age, educational level, body site, family history of skin cancer, and nevus characteristics. Methods: Self-counting of large nevi by 125 patients was compared with physician counting, with attention to nevus characteristics. Results: Overall, 79% of the self-counts agreed to within +/- 3 nevi of the physician's count. Analysis of variance revealed that the presence of nonpigmented or flat nevi significantly increased the chance of subject undercount, as did male sex. Conclusion: Self-counts of large nevi are comparable to physician's counts and may be useful for melanoma screening. C1 UNIV CALIF SAN FRANCISCO,DEPT DERMATOL,SAN FRANCISCO,CA 94143. UNIV CALIF SAN FRANCISCO,DEPT PATHOL,SAN FRANCISCO,CA. LAWRENCE LIVERMORE NATL LAB,LIVERMORE,CA. KAISER PERMANENTE,SAN RAFAEL,CA. NR 32 TC 25 Z9 25 U1 0 U2 0 PU MOSBY-YEAR BOOK INC PI ST LOUIS PA 11830 WESTLINE INDUSTRIAL DR, ST LOUIS, MO 63146-3318 SN 0190-9622 J9 J AM ACAD DERMATOL JI J. Am. Acad. Dermatol. PD SEP PY 1994 VL 31 IS 3 BP 438 EP 444 PN 1 PG 7 WC Dermatology SC Dermatology GA PE837 UT WOS:A1994PE83700006 PM 8077469 ER PT J AU GRAHAM, DW STINTON, DP AF GRAHAM, DW STINTON, DP TI DEVELOPMENT OF TANTALUM PENTOXIDE COATINGS BY CHEMICAL-VAPOR-DEPOSITION SO JOURNAL OF THE AMERICAN CERAMIC SOCIETY LA English DT Article ID MOLTEN-SALT CORROSION; SILICON-NITRIDE; SODIUM-SULFATE; HOT CORROSION; CERAMICS; DISSOLUTION; MECHANISM; KINETICS AB Thermochemical considerations clearly indicate a need for the protection of SiC and Si3N4 materials from HCl- and Na2SO4 induced corrosion. Ta2O5 has been identified as a material which may be suitable for such a protective coating. Thermodynamic calculations have indicated a range of temperatures, pressures, and reactant concentrations under which Ta2O5 coatings may be formed as a single phase by chemical vapor deposition. Ta2O5 coatings exhibiting a range of microstructures were obtained experimentally. RP GRAHAM, DW (reprint author), OAK RIDGE NATL LAB,OAK RIDGE,TN 37831, USA. NR 38 TC 10 Z9 11 U1 0 U2 4 PU AMER CERAMIC SOC PI WESTERVILLE PA 735 CERAMIC PLACE, PO BOX 6136, WESTERVILLE, OH 43081-6136 SN 0002-7820 J9 J AM CERAM SOC JI J. Am. Ceram. Soc. PD SEP PY 1994 VL 77 IS 9 BP 2298 EP 2304 DI 10.1111/j.1151-2916.1994.tb04597.x PG 7 WC Materials Science, Ceramics SC Materials Science GA PH199 UT WOS:A1994PH19900008 ER PT J AU SEARCY, AW BULLARD, JW AF SEARCY, AW BULLARD, JW TI THERMODYNAMICS AND KINETICS OF SURFACE-AREA CHANGES OF FACETED PARTICLES SO JOURNAL OF THE AMERICAN CERAMIC SOCIETY LA English DT Article ID EQUILIBRIUM; CONFIGURATIONS; ENERGY AB An equation is derived that describes the influence of particle size and shape on the free energies of particles of anisotropic specific surface free energies. When the specific surface free energy is isotropic, the general equation reduces directly to the Gibbs-Thomson equation for the chemical potential of spherical drops and predicts the accepted driving force for neck growth between two spherical particles. The general equation is also used to obtain equations for the chemical potentials of particles of nonequilibrium shapes and to derive alternate rate equations for different possible rate-controlling steps of mass transport when faceted {100} ridge/channel arrays etched into a {100} single-crystal surface decrease in depth to reduce the surface free energy. Edge free energies are suggested to sometimes play important roles in determining the sequence of shape changes that occur when particles of nonequilibrium shapes are annealed. C1 UNIV CALIF BERKELEY,DEPT MAT SCI & MINERAL ENGN,BERKELEY,CA 94720. RP SEARCY, AW (reprint author), UNIV CALIF BERKELEY,LAWRENCE BERKELEY LAB,DIV MAT SCI,BERKELEY,CA 94720, USA. NR 32 TC 15 Z9 15 U1 0 U2 6 PU AMER CERAMIC SOC PI WESTERVILLE PA 735 CERAMIC PLACE, PO BOX 6136, WESTERVILLE, OH 43081-6136 SN 0002-7820 J9 J AM CERAM SOC JI J. Am. Ceram. Soc. PD SEP PY 1994 VL 77 IS 9 BP 2314 EP 2318 DI 10.1111/j.1151-2916.1994.tb04599.x PG 5 WC Materials Science, Ceramics SC Materials Science GA PH199 UT WOS:A1994PH19900010 ER PT J AU BULLARD, JW GLAESE, AM SEARCY, AW AF BULLARD, JW GLAESE, AM SEARCY, AW TI SHAPE CHANGES BY (100) LITHIUM-FLUORIDE RIDGE-CHANNEL ARRAYS AND OF LITHIUM-FLUORIDE PARTICLES AT SINTERING TEMPERATURES SO JOURNAL OF THE AMERICAN CERAMIC SOCIETY LA English DT Article ID SURFACE AB Parallel channels of rectangular cross section were etched into an LIF {100} single-crystal surface, by a photolithography technique, to produce ridge-channel arrays of controlled size and shape. The shape changes undergone by these arrays and by LIB isolated particles and powder beds at sintering temperatures were studied by SEM. The ridge-channel arrays and particles developed either faceted or rounded shapes, depending on temperature and atmosphere. Adsorption of an impurity, presumably H2O or O-2, although it causes faceting,(1) increases the rate of mass transport from the ridges to channels. The influence of array geometry on mass transport rates is compared to models to show that the rate-limiting mass transfer step is probably a surface step when the surfaces remain faceted and may be a surface step when the surfaces are rounded. C1 UNIV CALIF BERKELEY,DEPT MAT SCI & MINERAL ENGN,BERKELEY,CA 94720. RP BULLARD, JW (reprint author), UNIV CALIF BERKELEY,LAWRENCE BERKELEY LAB,DIV MAT SCI,BERKELEY,CA 94720, USA. NR 20 TC 7 Z9 7 U1 0 U2 2 PU AMER CERAMIC SOC PI WESTERVILLE PA 735 CERAMIC PLACE, PO BOX 6136, WESTERVILLE, OH 43081-6136 SN 0002-7820 J9 J AM CERAM SOC JI J. Am. Ceram. Soc. PD SEP PY 1994 VL 77 IS 9 BP 2319 EP 2326 DI 10.1111/j.1151-2916.1994.tb04600.x PG 8 WC Materials Science, Ceramics SC Materials Science GA PH199 UT WOS:A1994PH19900011 ER PT J AU HENAGER, CH JONES, RH AF HENAGER, CH JONES, RH TI SUBCRITICAL CRACK-GROWTH IN CVI SILICON-CARBIDE REINFORCED WITH NICALON FIBERS - EXPERIMENT AND MODEL SO JOURNAL OF THE AMERICAN CERAMIC SOCIETY LA English DT Article ID HIGH-TEMPERATURE FAILURE; FRACTURE-RESISTANCE MECHANISM; AL2O3 BEND SPECIMENS; POLYCRYSTALLINE ALUMINA; ELEVATED-TEMPERATURES; STRESS-CORROSION; CERAMIC COMPOSITES; MATRIX CRACKING; AMORPHOUS PHASE; BRIDGED CRACKS AB Subcritical crack growth measurements of ceramic-matrix composites have been conducted on materials consisting of CVI SiC matrix reinforced with Nicalon fibers (SiC/SiCf) having C and BN fiber-matrix interfaces. Velocities of effective elastic cracks were determined as a function of applied stress intensity in pure Ar and in Ar plus 2000 ppm O-2 at 1100 degrees C. A stage-II regime, where the crack velocity depends only weakly on the applied stress intensity, was observed in the V-K diagrams over a range of applied stress intensities that correspond to the R-curve of the materials. This stage-II behavior was followed by a stage-III, or power-law, regime at higher stress intensity values. Oxygen was observed to increase the crack velocity in the stage-II regime and to shift the stage-II-to-stage-III transition to lower stress intensity values. A 2D micromechanics approach was developed to model the time dependence of observed crack-bridging events and is able to rationalize the measured effective crack velocities, the time dependence of the crack velocity, and the stage-II-to-stage-II transition in terms of the stress relaxation of crack-bridging fibers. RP PACIFIC NW LAB, POB 999, RICHLAND, WA 99352 USA. OI Henager, Chuck/0000-0002-8600-6803 NR 69 TC 56 Z9 56 U1 0 U2 5 PU WILEY-BLACKWELL PI HOBOKEN PA 111 RIVER ST, HOBOKEN 07030-5774, NJ USA SN 0002-7820 EI 1551-2916 J9 J AM CERAM SOC JI J. Am. Ceram. Soc. PD SEP PY 1994 VL 77 IS 9 BP 2381 EP 2394 DI 10.1111/j.1151-2916.1994.tb04609.x PG 14 WC Materials Science, Ceramics SC Materials Science GA PH199 UT WOS:A1994PH19900020 ER PT J AU BESMANN, TM MILLER, JH COOLEY, KM LOWDEN, RA STARR, TL AF BESMANN, TM MILLER, JH COOLEY, KM LOWDEN, RA STARR, TL TI CHEMICAL-VAPOR INFILTRATION OF TIB2-MATRIX COMPOSITES SO JOURNAL OF THE AMERICAN CERAMIC SOCIETY LA English DT Article ID ALUMINUM SMELTING CELLS; LIQUID ALUMINUM; CERAMIC COMPOSITES; ENVIRONMENTS; CATHODES AB The efficiency of the Hall-Heroult electrolytic reduction of aluminum can be substantially improved by the use of a TiB2 cathode. The use of TiB2 components, however, has been hampered by the brittle nature of the material and the grain boundary attack of sintering-aid phases by molten aluminum. In the current work, TiB2 is toughened through the use of reinforcing fibers, with chemical vapor infiltration used to produce the TiB2 matrix. In early efforts it was observed that the formation of TiB2 from chloride precursors at fabrication temperatures below 900-1000 degrees C may have allowed the retention of destructive levels of chlorine. At higher fabrication temperatures (>1000 degrees C), using appropriate infiltration conditions as determined from the use of a process model, TiB2/THORNEL P-25 fiber composites have been fabricated in 20 h. The improved composite material has been demonstrated to be stable in molten aluminum in short-duration (24 h) tests. C1 GEORGIA TECH RES INST,ATLANTA,GA 30337. RP BESMANN, TM (reprint author), OAK RIDGE NATL LAB,DIV MET & CERAM,POB 2008,OAK RIDGE,TN 37831, USA. NR 22 TC 4 Z9 4 U1 0 U2 0 PU AMER CERAMIC SOC PI WESTERVILLE PA 735 CERAMIC PLACE, PO BOX 6136, WESTERVILLE, OH 43081-6136 SN 0002-7820 J9 J AM CERAM SOC JI J. Am. Ceram. Soc. PD SEP PY 1994 VL 77 IS 9 BP 2395 EP 2400 DI 10.1111/j.1151-2916.1994.tb04610.x PG 6 WC Materials Science, Ceramics SC Materials Science GA PH199 UT WOS:A1994PH19900021 ER PT J AU LYNN, R GINSBERG, N STALL, S BRIGNOL, YF ZABETAKIS, P DEVITA, M WANG, J PIERSON, R MA, R AF LYNN, R GINSBERG, N STALL, S BRIGNOL, YF ZABETAKIS, P DEVITA, M WANG, J PIERSON, R MA, R TI A COMPARISON OF 4 METHODS FOR ESTIMATING FAT-FREE MASS NFFM) IN DIALYSIS PATIENTS SO JOURNAL OF THE AMERICAN SOCIETY OF NEPHROLOGY LA English DT Meeting Abstract C1 VAUGHN FOLKERT BAUMRITTER KIDNEY CTR,LENOX HILL,NY. BROOKHAVEN NATL LAB,SUFFOLK,NY. ST LUKES ROOSEVELT HOSP,NEW YORK,NY 10025. BROOKHAVEN NATL LAB,NEW YORK,NY. NR 0 TC 4 Z9 4 U1 0 U2 0 PU WILLIAMS & WILKINS PI BALTIMORE PA 351 WEST CAMDEN ST, BALTIMORE, MD 21201-2436 SN 1046-6673 J9 J AM SOC NEPHROL JI J. Am. Soc. Nephrol. PD SEP PY 1994 VL 5 IS 3 BP 497 EP 497 PG 1 WC Urology & Nephrology SC Urology & Nephrology GA PG771 UT WOS:A1994PG77101005 ER PT J AU TRYGGVASSON, K KESTILA, M MANNIKKO, M HOLMBERG, C LEISTI, J PELTONEN, L OLSEN, A AF TRYGGVASSON, K KESTILA, M MANNIKKO, M HOLMBERG, C LEISTI, J PELTONEN, L OLSEN, A TI MAPPING OF THE LOCUS FOR CONGENITAL NEPHROTIC SYNDROME OF THE FINNISH TYPE (CNF) ON CHROMOSOME 19Q SO JOURNAL OF THE AMERICAN SOCIETY OF NEPHROLOGY LA English DT Meeting Abstract C1 UNIV HELSINKI,SF-00100 HELSINKI 10,FINLAND. NATL PUBL HLTH INST,SF-00280 HELSINKI 28,FINLAND. LAWRENCE LIVERMORE NATL LAB,LIVERMORE,CA 94550. NR 0 TC 1 Z9 1 U1 0 U2 1 PU WILLIAMS & WILKINS PI BALTIMORE PA 351 WEST CAMDEN ST, BALTIMORE, MD 21201-2436 SN 1046-6673 J9 J AM SOC NEPHROL JI J. Am. Soc. Nephrol. PD SEP PY 1994 VL 5 IS 3 BP 638 EP 638 PG 1 WC Urology & Nephrology SC Urology & Nephrology GA PG771 UT WOS:A1994PG77101567 ER PT J AU HANCOCK, WW COUGHLAN, AF KENNEL, SJ BIRD, PI AF HANCOCK, WW COUGHLAN, AF KENNEL, SJ BIRD, PI TI RETINOIC ACID REDUCES ENDOTHELIAL INJURY BY ENDOTOXEMIA - QUANTITATIVE-ANALYSIS OF RENAL THROMBOMODULIN EXPRESSION, TISSUE FACTOR INDUCTION, FIBRIN DEPOSITION AND LEUKOCYTE INFILTRATION SO JOURNAL OF THE AMERICAN SOCIETY OF NEPHROLOGY LA English DT Meeting Abstract C1 MONASH UNIV SCH MED,MELBOURNE,AUSTRALIA. OAK RIDGE NATL LAB,OAK RIDGE,TN 37830. NR 0 TC 1 Z9 1 U1 0 U2 0 PU WILLIAMS & WILKINS PI BALTIMORE PA 351 WEST CAMDEN ST, BALTIMORE, MD 21201-2436 SN 1046-6673 J9 J AM SOC NEPHROL JI J. Am. Soc. Nephrol. PD SEP PY 1994 VL 5 IS 3 BP 780 EP 780 PG 1 WC Urology & Nephrology SC Urology & Nephrology GA PG771 UT WOS:A1994PG77102132 ER PT J AU WINDISCH, CF BAER, DR ENGELHARD, MH AF WINDISCH, CF BAER, DR ENGELHARD, MH TI THE EFFECT OF SULFUR ON THE PASSIVATION OF IRON IN CALCIUM NITRATE SO JOURNAL OF THE ELECTROCHEMICAL SOCIETY LA English DT Article ID INTERGRANULAR STRESS-CORROSION; GRAIN-BOUNDARY CHEMISTRY; ALLOYS AB Electrochemical polarization experiments in conjunction with surface analyses using ultrahigh vacuum transfer showed that the presence of S, above a certain threshold amount, accelerated the corrosion of Fe when polarized at a normally passive potential in 55 weight percent Ca(NO3)2 solution at 60-degrees-C. Above the threshold amount, the corrosion rate did not depend on the S content. During corrosion, much of the S remained in the corrosion product film, and a large portion of the charge passed contributed to film growth. Similiarities between the effects of S and those of P reported previously may help explain the similar influences of S and P as grain boundary impurities on the intergranular stress corrosion cracking of Fe. RP WINDISCH, CF (reprint author), PACIFIC NW LAB, RICHLAND, WA 99352 USA. RI Engelhard, Mark/F-1317-2010; Baer, Donald/J-6191-2013 OI Baer, Donald/0000-0003-0875-5961 NR 17 TC 7 Z9 7 U1 1 U2 3 PU ELECTROCHEMICAL SOC INC PI PENNINGTON PA 10 SOUTH MAIN STREET, PENNINGTON, NJ 08534 SN 0013-4651 J9 J ELECTROCHEM SOC JI J. Electrochem. Soc. PD SEP PY 1994 VL 141 IS 9 BP 2343 EP 2349 DI 10.1149/1.2055123 PG 7 WC Electrochemistry; Materials Science, Coatings & Films SC Electrochemistry; Materials Science GA PG286 UT WOS:A1994PG28600027 ER PT J AU CONTOLINI, RJ BERNHARDT, AF MAYER, ST AF CONTOLINI, RJ BERNHARDT, AF MAYER, ST TI ELECTROCHEMICAL PLANARIZATION FOR MULTILEVEL METALLIZATION SO JOURNAL OF THE ELECTROCHEMICAL SOCIETY LA English DT Article ID POLYIMIDE; TUNGSTEN; ALUMINUM; COPPER; TOPOGRAPHY; SUBSTRATE AB We describe an electrochemical planarization technology involving electroplating followed by electropolishing, resulting in a very flat surface containing embedded conductors. Electrochemical planarization technology has been used to produce silicon substrate multichip modules.1 Both the electroplating and electropolishing processes have a thickness uniformity of better than +/-2% (+/-3sigma) across a 100 mm wafer. RP CONTOLINI, RJ (reprint author), LAWRENCE LIVERMORE NATL LAB,LIVERMORE,CA 94550, USA. NR 60 TC 39 Z9 39 U1 1 U2 2 PU ELECTROCHEMICAL SOC INC PI PENNINGTON PA 10 SOUTH MAIN STREET, PENNINGTON, NJ 08534 SN 0013-4651 J9 J ELECTROCHEM SOC JI J. Electrochem. Soc. PD SEP PY 1994 VL 141 IS 9 BP 2503 EP 2510 DI 10.1149/1.2055151 PG 8 WC Electrochemistry; Materials Science, Coatings & Films SC Electrochemistry; Materials Science GA PG286 UT WOS:A1994PG28600055 ER PT J AU GLENN, DF INGRAM, JC AF GLENN, DF INGRAM, JC TI ELECTRODEPOSITION AT AN ICE-COATED ELECTRODE SO JOURNAL OF THE ELECTROCHEMICAL SOCIETY LA English DT Letter AB The use of a working electrode coated with a thin layer of frost-like ice has been investigated. It was found that copper can be continuously electrodeposited at such an electrode, and the resultant particulate deposite can be trapped in a growing ice layer. RP GLENN, DF (reprint author), IDAHO NATL ENGN LAB,IDAHO FALLS,ID 83415, USA. NR 6 TC 1 Z9 1 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 SEP PY 1994 VL 141 IS 9 BP L113 EP L114 DI 10.1149/1.2055171 PG 2 WC Electrochemistry; Materials Science, Coatings & Films SC Electrochemistry; Materials Science GA PG286 UT WOS:A1994PG28600005 ER PT J AU RAO, NSV AF RAO, NSV TI FUSION METHODS FOR MULTIPLE SENSOR SYSTEMS WITH UNKNOWN ERROR DENSITIES SO JOURNAL OF THE FRANKLIN INSTITUTE-ENGINEERING AND APPLIED MATHEMATICS LA English DT Article AB Consider that the sensor S-i, i = 1, 2,...,N, output y((i)) is an element of R(d), according to an unknown probability density p(i)(y(i)\x), corresponding to an object with parameter x is an element of R(d). For the system of N sensors, S-1, S-2,...,S-N, a training l-sample (x1,y1), (x2,y2),...,(x is to minimized over a family of fusion rules F based on the given l-sample. Let f* is an element of F minimize I(f). In general, f* cannot be computed since the underlying probability densities are unknown. Using V apnik's empirical risk minimization method, we show that if F has finite capacity, then under bounded error condition, for sufficiently large sample, ($) over cap f can be obtained such that for arbitrarily specified epsilon > 0 and delta, 0 < delta < 1. We obtain similar conditions for the case when F is a set of Lipschitz continuous functions with a fixed constant, these conditions are applicable to feedforward neural networks with a particular with a particular type of sigmoidal units. Then we identify sufficiency conditions for the composite system (of fuser and sensors) to be better than the best of the individual sensors. We then discuss linearly separable systems to identify objects from a finite class where ($) over cap f can be computed in polynomial time using quadratic programming methods. RP RAO, NSV (reprint author), OAK RIDGE NATL LAB,CTR ENGN SYST ADV RES,OAK RIDGE,TN 37831, USA. OI Rao, Nageswara/0000-0002-3408-5941 NR 0 TC 7 Z9 7 U1 0 U2 0 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD, ENGLAND OX5 1GB SN 0016-0032 J9 J FRANKLIN I JI J. Frankl. Inst.-Eng. Appl. Math. PD SEP PY 1994 VL 331B IS 5 BP 509 EP 530 DI 10.1016/0016-0032(94)90035-3 PG 22 WC Automation & Control Systems; Engineering, Multidisciplinary; Engineering, Electrical & Electronic; Mathematics, Interdisciplinary Applications SC Automation & Control Systems; Engineering; Mathematics GA RU247 UT WOS:A1994RU24700004 ER PT J AU BATEMAN, VI BROWN, FA AF BATEMAN, VI BROWN, FA TI EVALUATION OF SHOCK MITIGATING MATERIALS IN A V-BAND PYROSHOCK ENVIRONMENT SIMULATED WITH A RESONANT FIXTURE SO JOURNAL OF THE IES LA English DT Article AB An explosively activated V-band joint is used on a multistage rocket payload to release components at prescribed times in the rocket's flight and creates a pyroshock environment that the other payload components must survive. Accelerometer response data were measured close to an actual V-band pyroshock. With the shock spectra calculated from these data, a resonant fixture was designed to simulate a V-band pyroshock event. The characteristics of the data and the design process are described. Laboratory tests were conducted to determine that the desired shock spectra with an unusually high knee at about 8,000 Hz was produced with the resonant fixture. The fixture was then mounted on a 29-in.-diameter, 2-in.-thick plate simulation of a payload plate. Simulated electronic components were also mounted on the plate. The pyroshock environment simulation was created by the resonant fixture response to a projectile impact. The component response to the environment was measured at the electronic component. The component responses to the pyroshock were measured with five different shock mitigating materials inserted between the resonant fixture and the payload plate simulation, and the peak response values were tabulated. RP BATEMAN, VI (reprint author), SANDIA NATL LABS,MECH SHOCK TESTING LAB,ALBUQUERQUE,NM 87185, USA. NR 0 TC 1 Z9 1 U1 0 U2 0 PU INST ENVIRONMENTAL SCI PI MT PROSPECT PA 940 E NORTHWEST HIGHWAY, MT PROSPECT, IL 60056 SN 1052-2883 J9 J IES JI J. IES PD SEP-OCT PY 1994 VL 37 IS 5 BP 40 EP 45 PG 6 WC Engineering, Environmental; Environmental Sciences; Instruments & Instrumentation SC Engineering; Environmental Sciences & Ecology; Instruments & Instrumentation GA PP036 UT WOS:A1994PP03600007 ER PT J AU DELONG, KW TREBINO, R AF DELONG, KW TREBINO, R TI IMPROVED ULTRASHORT PULSE-RETRIEVAL ALGORITHM FOR FREQUENCY-RESOLVED OPTICAL GATING SO JOURNAL OF THE OPTICAL SOCIETY OF AMERICA A-OPTICS IMAGE SCIENCE AND VISION LA English DT Article ID COMPLEX-VALUED OBJECT; PHASE-RETRIEVAL; INTENSITY AB We report on significant improvements in the pulse-retrieval algorithm used to reconstruct the amplitude and the phase of ultrashort optical pulses from the experimental frequency-resolved optical gating trace data in the polarization-gate geometry. These improvements involve the use of an intensity constraint, an overcorrection technique, and a multidimensional minimization scheme. While the previously published, basic algorithm converged for most common ultrashort pulses, it failed to retrieve pulses with significant intensity substructure. The improved composite algorithm successfully converges for such pulses. It can now retrieve essentially all pulses of practical interest. We present examples of complex waveforms that were retrieved by the improved algorithm. RP DELONG, KW (reprint author), SANDIA NATL LABS,COMBUST RES FACIL,LIVERMORE,CA 94551, USA. NR 12 TC 59 Z9 60 U1 1 U2 15 PU OPTICAL SOC AMER PI WASHINGTON PA 2010 MASSACHUSETTS AVE NW, WASHINGTON, DC 20036 SN 0740-3232 J9 J OPT SOC AM A JI J. Opt. Soc. Am. A-Opt. Image Sci. Vis. PD SEP PY 1994 VL 11 IS 9 BP 2429 EP 2437 DI 10.1364/JOSAA.11.002429 PG 9 WC Optics SC Optics GA PD990 UT WOS:A1994PD99000008 ER PT J AU NAQVI, SSH KRUKAR, RH MCNEIL, JR FRANKE, JE NIEMCZYK, TM HAALAND, DM GOTTSCHO, RA KORNBLIT, A AF NAQVI, SSH KRUKAR, RH MCNEIL, JR FRANKE, JE NIEMCZYK, TM HAALAND, DM GOTTSCHO, RA KORNBLIT, A TI ETCH DEPTH ESTIMATION OF LARGE-PERIOD SILICON GRATINGS WITH MULTIVARIATE CALIBRATION OF RIGOROUSLY SIMULATED DIFFRACTION PROFILES SO JOURNAL OF THE OPTICAL SOCIETY OF AMERICA A-OPTICS IMAGE SCIENCE AND VISION LA English DT Article ID LEAST-SQUARES METHODS; DIMENSIONAL METROLOGY; LATENT IMAGES; FILMS; LIGHT AB Diffraction from a periodic structure is sensitive to small changes in the shape of that structure. It is possible to exploit this behavior of the scatter data for accurate, precise, rapid, nondestructive, and in situ measurements of grating structures. We present the use of rigorous coupled-wave theory to generate diffraction profiles to train a partial least-squares (PLS) multivariate calibration routine. The resulting PLS calibration model was applied to experimental diffraction data from gratings in etched bulk silicon to predict etch depths. A single-detector scanning scatterometer was used to measure the scatter from 32-mum-pitch structures illuminated with a He-Ne laser beam. The scatterometer measured the diffraction patterns from grating structures at 14 die locations on each of a set of five wafers. The theoretically based PLS estimator was then used to predict etch depths from scatterometry data obtained from the 70 different grating structures. The etch depth predictions were in excellent agreement with those obtained with a scanning force microscope (i.e., 0.9-mum-deep structures were predicted with an average error of 0.007 mum). This is a significant step toward the solution of the parametric inverse grating diffraction problem: that of quantitative prediction of structure dimensions from the measurement of scatter data. C1 UNIV NEW MEXICO,DEPT CHEM,ALBUQUERQUE,NM 87131. SANDIA NATL LABS,ALBUQUERQUE,NM 87131. AT&T BELL LABS,MURRAY HILL,NJ 07974. RP NAQVI, SSH (reprint author), UNIV NEW MEXICO,CTR HIGH TECHNOL,ALBUQUERQUE,NM 87131, USA. NR 33 TC 31 Z9 31 U1 0 U2 0 PU OPTICAL SOC AMER PI WASHINGTON PA 2010 MASSACHUSETTS AVE NW, WASHINGTON, DC 20036 SN 0740-3232 J9 J OPT SOC AM A JI J. Opt. Soc. Am. A-Opt. Image Sci. Vis. PD SEP PY 1994 VL 11 IS 9 BP 2485 EP 2493 DI 10.1364/JOSAA.11.002485 PG 9 WC Optics SC Optics GA PD990 UT WOS:A1994PD99000014 ER PT J AU DELONG, KW TREBINOI, R KANE, DJ AF DELONG, KW TREBINOI, R KANE, DJ TI COMPARISON OF ULTRASHORT-PULSE FREQUENCY-RESOLVED-OPTICAL-GATING TRACES FOR 3 COMMON BEAM GEOMETRIES SO JOURNAL OF THE OPTICAL SOCIETY OF AMERICA B-OPTICAL PHYSICS LA English DT Article ID LIGHT-PULSES; PHASE; AMPLITUDE; COMPENSATION; INTENSITY AB We recently introduced frequency-resolved optical gating (FROG), a technique for measuring the intensity and phase of an individual, arbitrary, ultrashort laser pulse. FROG can use almost any instantaneous optical nonlinearity, with the most common geometries being polarization gate, self-diffraction, and second-harmonic generation. The experimentally generated FROG trace is intuitive, visually appealing, and can yield quantitative information about the pulse parameters (such as temporal and spectral width and chirp). However, the qualitative and the quantitative features of the FROG trace depend strongly on the geometry used. We compare the FROG traces for several common ultrashort pulses for these three common geometries and, where possible, develop scaling rules that allow one to obtain quantitative information about the pulse directly from the experimental FROG trace. We illuminate the important features of the various FROG traces for transform-limited, linearly chirped, self-phase modulated, and nonlinearly chirped pulses, pulses with simultaneous linear chirp and self-phase modulation, and pulses with simultaneous linear chirp and cubic phase distortion, as well as double pulses, pulses with phase jumps, and pulses with complex intensity and phase substructure. C1 SW SCI INC,SANTA FE,NM 87501. RP DELONG, KW (reprint author), SANDIA NATL LABS,COMBUST RES FACIL,LIVERMORE,CA 94551, USA. NR 37 TC 122 Z9 124 U1 2 U2 10 PU OPTICAL SOC AMER PI WASHINGTON PA 2010 MASSACHUSETTS AVE NW, WASHINGTON, DC 20036 SN 0740-3224 J9 J OPT SOC AM B JI J. Opt. Soc. Am. B-Opt. Phys. PD SEP PY 1994 VL 11 IS 9 BP 1595 EP 1608 DI 10.1364/JOSAB.11.001595 PG 14 WC Optics SC Optics GA PE853 UT WOS:A1994PE85300009 ER PT J AU LEVINE, AM OZIZMIR, E TREBINO, R HAYDEN, CC JOHNSON, AM TOKUDA, KL AF LEVINE, AM OZIZMIR, E TREBINO, R HAYDEN, CC JOHNSON, AM TOKUDA, KL TI INDUCED-GRATING AUTOCORRELATION OF ULTRASHORT PULSES IN A SLOWLY RESPONDING MEDIUM SO JOURNAL OF THE OPTICAL SOCIETY OF AMERICA B-OPTICAL PHYSICS LA English DT Article ID MULTI-PHOTON IONIZATION; SINGLE-SHOT MEASUREMENT; LASER-PULSES; FREQUENCY-DOMAIN; AUTO-CORRELATION; SUBPICOSECOND PULSES; 2-PHOTON ABSORPTION; WIDTH MEASUREMENT; CHIRP MEASUREMENT; PHASE MEASUREMENT AB We consider induced-grating autocorrelation (IGA) in a slowly responding medium and study three possible geometries (two-beam coupling, three-beam induced grating, and self-diffraction) in two different limiting cases (single-pulse experiments and many-pulse accumulated-grating experiments). We find that in five of these six cases the IGA trace is given by the squared amplitude of the electric-field correlation function, thus yielding information about the spectrum of the pulse. Theoretical expressions for the IGA trace are derived for both linearly chirped and self-phase-modulated pulses. Experiments performed with self-phase-modulated pulses are in excellent agreement with the theory. In this case we show how the measured IGA trace can be used to determine both pulse duration and pulse bandwidth. C1 SANDIA NATL LABS, COMBUST RES FACIL, LIVERMORE, CA 94551 USA. AT&T BELL LABS, HOLMDEL, NJ 07733 USA. RP CUNY COLL STATEN ISL, STATEN ISL, NY 10301 USA. NR 57 TC 14 Z9 14 U1 0 U2 4 PU OPTICAL SOC AMER PI WASHINGTON PA 2010 MASSACHUSETTS AVE NW, WASHINGTON, DC 20036 USA SN 0740-3224 EI 1520-8540 J9 J OPT SOC AM B JI J. Opt. Soc. Am. B-Opt. Phys. PD SEP PY 1994 VL 11 IS 9 BP 1609 EP 1618 DI 10.1364/JOSAB.11.001609 PG 10 WC Optics SC Optics GA PE853 UT WOS:A1994PE85300010 ER PT J AU NELSON, AJ HASOON, F LEVI, D AF NELSON, AJ HASOON, F LEVI, D TI PROCESSING AND CHARACTERIZATION OF LARGE-GRAIN THIN-FILM CDTE SO JOURNAL OF VACUUM SCIENCE & TECHNOLOGY A-VACUUM SURFACES AND FILMS LA English DT Article ID CDS/CDTE SOLAR-CELLS; PHOTOVOLTAIC PROPERTIES; CDCL2; SURFACE AB Basic material studies addressing the growth and processing of CdTe have resulted in dense, defect-free as-grown CdTe films on 7059 glass with initial grain sizes of almost-equal-to0.2 mum. Innovations in postdeposition processing (no CdCl2) have resulted in films with >50 mum grain sizes. Scanning electron microscopy analyses confirm film density while concurrent cathodluminescence reveals a change in the recombination efficiency. Transmission electron microscopy analyses reveal that films grown below 300-degrees-C are defect-free, while films grown above 300-degrees-C contain defects. Photoluminescence lifetime measurements reveal a fivefold increase in lifetime following posdeposition processing of these films. These results were correlated with x-ray photoemission measurements of the Te 4d, Cd, 4d, and valence band. This indicates that grain boundaries are the main factor limiting lifetimes. Based on these results, we have developed an understanding of the effects of oxygen and grain boundary oxides on postdeposition processing and enhanced grain growth. RP NELSON, AJ (reprint author), NATL RENEWABLE ENERGY LAB,GOLDEN,CO 80401, USA. NR 20 TC 13 Z9 13 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 SEP-OCT PY 1994 VL 12 IS 5 BP 2803 EP 2807 DI 10.1116/1.578947 PG 5 WC Materials Science, Coatings & Films; Physics, Applied SC Materials Science; Physics GA PH791 UT WOS:A1994PH79100031 ER PT J AU TENCH, RJ CHOW, R KOZLOWSKI, MR AF TENCH, RJ CHOW, R KOZLOWSKI, MR TI CHARACTERIZATION OF DEFECT GEOMETRIES IN MULTILAYER OPTICAL COATINGS SO JOURNAL OF VACUUM SCIENCE & TECHNOLOGY A-VACUUM SURFACES AND FILMS LA English DT Article AB Laser-induced damage in optical coatings is generally associated with micrometer-scale defects. A simple geometric model for nodule-shaped defects is commonly used to describe defects in optical coatings. No systematic study has been done, however, to prove the applicability of that model to an optical coating deposition process. Not all defects have a classic nodule geometry. The present study uses atomic force microscopy (AFM) and scanning electron microscopy to characterize the topography of coating defects in a HfO2/SiO2 multilayer mirror system. Focused ion-beam cross sectioning is then used to study the underlying defect structure. This work develops a model for defect shape such that the overall geometry of a coating defect, particularly the seed size and depth, can be inferred from nondestructive evaluation measurements such as AFM. The relative mechanical stabilities of nodular defects can be deduced based on the nodule's geometry. Auger analysis showed that the seed material that causes nodular defects in HfO2/SiO2 multilayers is a hafnia oxide. Such characterization capabilities are needed for understanding the enhanced susceptibility of particular defects to laser damage and for developing improved techniques for depositing low-defect density coatings. RP TENCH, RJ (reprint author), LAWRENCE LIVERMORE NATL LAB,POB 808,L-340,LIVERMORE,CA 94551, USA. NR 12 TC 37 Z9 38 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 SEP-OCT PY 1994 VL 12 IS 5 BP 2808 EP 2813 DI 10.1116/1.578948 PG 6 WC Materials Science, Coatings & Films; Physics, Applied SC Materials Science; Physics GA PH791 UT WOS:A1994PH79100032 ER PT J AU ERCK, RA AF ERCK, RA TI OBSERVATION OF CRYOPUMP FLUORESCENCE DURING OPERATION OF ELECTRON-BEAM EVAPORATOR SO JOURNAL OF VACUUM SCIENCE & TECHNOLOGY A-VACUUM SURFACES AND FILMS LA English DT Note AB A blue-green glow was observed in the cold-plate section of a conventional cryogenic pump used in a vacuum-deposition chamber. The fluororescence is associated with operation of an electron-beam evaporator and is present at all gas pressures and evaporator voltages used, but cannot be made to occur during operation of a 1 kV Kaufman-type ion source or a 3 kV electron source. RP ERCK, RA (reprint author), ARGONNE NATL LAB,DIV ENERGY TECHNOL,ARGONNE,IL 60439, 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 0734-2101 J9 J VAC SCI TECHNOL A JI J. Vac. Sci. Technol. A-Vac. Surf. Films PD SEP-OCT PY 1994 VL 12 IS 5 BP 2931 EP 2932 DI 10.1116/1.578968 PG 2 WC Materials Science, Coatings & Films; Physics, Applied SC Materials Science; Physics GA PH791 UT WOS:A1994PH79100052 ER PT J AU BAI, M CAMPISI, L FREIMUTH, P AF BAI, M CAMPISI, L FREIMUTH, P TI VITRONECTIN RECEPTOR ANTIBODIES INHIBIT INFECTION OF HELA AND A549 CELLS BY ADENOVIRUS-TYPE-12 BUT NOT BY ADENOVIRUS TYPE-2 SO JOURNAL OF VIROLOGY LA English DT Article ID PENTON BASE; ATTACHMENT; ADHESION; INTEGRIN-ALPHA-V-BETA-3; SEQUENCES; INTEGRINS; SURFACE; VIRION; RGD AB The penton base gene from adenovirus type 12 (Ad12) was sequenced and encodes a 497-residue polypeptide, 74 residues shorter than the penton base from Ad2. The Ad2 and Ad12 proteins are highly conserved at the amino- and carboxy-terminal ends but diverge radically in the central region, where 63 residues are missing from the Ad12 sequence. Conserved within this variable region is the sequence Arg-Gly-Asp (RGD), which, in the Ad2 penton base, binds to integrins in the target cell membrane, enhancing the rate or the efficiency of infection. The Ad12 penton base was expressed in Escherichia coli, and the purified refolded protein assembled in vitro with Ad2 fibers. In contrast to the Ad2 penton base, the Ad12 protein failed to cause the rounding of adherent cells or to promote attachment of HeLa S3 suspension cells; however, A549 cells did attach to surfaces coated vith either protein and pretreatment of the cells with an integrin alpha v beta 3 monoclonal antibody reduced attachment to background levels. Treatment of HeLa ind A549 cells with integrin alpha v beta 3 or alpha v beta 5 monoclonal antibodies or with an RGD-containing fragment of the Ad2 penton base protein inhibited infection by Ad12 but had no effect on and in some cases enhanced infection by Ad2. Purified Ad2 fiber protein reduced the binding of radiolabeled Ad2 and Ad12 virions to HeLa and A549 cells nearly to background levels, but the concentrations of fiber that strongly inhibited infection by Ad2 only weakly inhibited Ad12 infection. These data suggest that alpha v-containing integrins alone may be sufficient to support infection by Ad12 and that this pathway is not efficiently used by Ad2. C1 BROOKHAVEN NATL LAB,DEPT BIOL,UPTON,NY 11973. NR 39 TC 80 Z9 82 U1 0 U2 0 PU AMER SOC MICROBIOLOGY PI WASHINGTON PA 1325 MASSACHUSETTS AVENUE, NW, WASHINGTON, DC 20005-4171 SN 0022-538X J9 J VIROL JI J. Virol. PD SEP PY 1994 VL 68 IS 9 BP 5925 EP 5932 PG 8 WC Virology SC Virology GA PB785 UT WOS:A1994PB78500066 PM 7520097 ER PT J AU HUNSAKER, CT ONEILL, RV JACKSON, BL TIMMINS, SP LEVINE, DA NORTON, DJ AF HUNSAKER, CT ONEILL, RV JACKSON, BL TIMMINS, SP LEVINE, DA NORTON, DJ TI SAMPLING TO CHARACTERIZE LANDSCAPE PATTERN SO LANDSCAPE ECOLOGY LA English DT Article AB Current reseach suggests that metrics of landscape pattern may reflect ecological processes operating at different scales and may provide an appropriate indicator for monitoring regional ecological changes. This paper examines the extent to which a 1/16 areal subset of the landscape using equally spaced 40-km2 hexagons can characterize the spatial extent of land cover types and landscape pattern (number of types of edges, patch shape complexity, dominance, and contagion). For 200-m resolution data the hexagon subset gives a reasonable estimate of overall landscape cover but may not be adequate for monitoring uncommon land cover types such as wetlands. For agriculture and forest, their proportion of the full landscape units is only outside the 95% confidence interval of the hexagon estimate 4-8% of the time, whereas the proportions for wetland and barren areas are outside the confidence interval 11-34% of the time. The hexagon subset a so does not appear to be adequate as the sole basis for monitoring landscape pattern. The values for contagion, dominance, and shape complexity calculated on the full landscape units are outside the 95% confidence interval of the hexagon estimate 27-76% of the time. Other statistical analyses include regressions between full landscape and hexagon subsets, mean differences and standard errors along with tests on number of positive and negative values, and percent relative error of hexagon estimates. RP HUNSAKER, CT (reprint author), OAK RIDGE NATL LAB,DIV ENVIRONM SCI,OAK RIDGE,TN 37831, USA. OI Hunsaker, Carolyn/0000-0002-5662-2402 NR 0 TC 69 Z9 76 U1 1 U2 3 PU S P B ACADEMIC PUBLISHING BV PI LELYSTAD PA PLATINASTRAAT 33, 8211 AR LELYSTAD, NETHERLANDS SN 0921-2973 J9 LANDSCAPE ECOL JI Landsc. Ecol. PD SEP PY 1994 VL 9 IS 3 BP 207 EP 226 DI 10.1007/BF00134748 PG 20 WC Ecology; Geography, Physical; Geosciences, Multidisciplinary SC Environmental Sciences & Ecology; Physical Geography; Geology GA PL166 UT WOS:A1994PL16600004 ER PT J AU ANDERSON, RA AF ANDERSON, RA TI ELECTROSTATIC FORCES IN AN IDEAL SPHERICAL-PARTICLE ELECTRORHEOLOGICAL FLUID SO LANGMUIR LA English DT Article ID SPHERES; CONDUCTIVITY; SUSPENSIONS; LATTICES AB This paper examines an ideal electrorheological (ER) fluid containing chains of monodisperse spherical particles. The interparticle attractive force is analytically approximated in the infinite-alpha limit, where alpha is the ratio of particle and liquid phase dielectric constants. For small interparticle gaps this force becomes inversely dependent on the gap width. Equipotential distributions associated with chains of contacting spheres are numerically calculated over the range of finite alpha. The interparticle attractive force and the field enhancement in the liquid phase near an interparticle contact point are both found to vary approximately as alpha(2) for alpha > 6, with the dependence becoming exact as alpha-->infinity. For a chain having small interparticle gaps, the attractive force and the field enhancement smoothly approach their analytically determined limiting values as alpha becomes large, and both are nearly saturated at alpha = 1000. Single-chain results are applied to regular-lattice arrangements of spheres to estimate the breaking strength of a dense column of particles at large alpha. The increase in strength compared with isolated chains of particles is 33% or less. A new, quasistatic model is proposed in which columns attached to the electrodes deform without breaking and become inclined at a 30 degrees angle, thereby generating maximal shear stress. Predicted yield stresses are well above those from conventional models. The effective dielectric constant of an ER fluid having particles arranged in columns is estimated in the infinite-alpha limit, with the highest value found for the c-axis aligned, body-centered tetragonal arrangement and also for close-packed lattices. The dielectric constant is then nearly 4 times as large as for a random particle dispersion. A readily observable dielectric anisotropy also develops in high-alpha ER fluids, but it contributes negligibly to the shear stress compared with the tension in columns of particles. RP ANDERSON, RA (reprint author), SANDIA NATL LABS,POB 5800,ALBUQUERQUE,NM 87185, USA. NR 25 TC 67 Z9 68 U1 1 U2 4 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 SN 0743-7463 J9 LANGMUIR JI Langmuir PD SEP PY 1994 VL 10 IS 9 BP 2917 EP 2928 DI 10.1021/la00021a013 PG 12 WC Chemistry, Multidisciplinary; Chemistry, Physical; Materials Science, Multidisciplinary SC Chemistry; Materials Science GA PH964 UT WOS:A1994PH96400013 ER PT J AU KAPOOR, S LAWLESS, D KENNEPOHL, P MEISEL, D SERPONE, N AF KAPOOR, S LAWLESS, D KENNEPOHL, P MEISEL, D SERPONE, N TI REDUCTION AND AGGREGATION OF SILVER IONS IN AQUEOUS GELATIN SOLUTIONS SO LANGMUIR LA English DT Article ID PULSE-RADIOLYSIS; OLIGOMER CLUSTERS; PARTICLES; METAL; POLYACRYLATE; GROWTH; ATOMS; AG+ AB Radiolytic reduction of silver ions and the subsequent formation of silver clusters were studied in aqueous gelatin solutions and are compared with the parallel processes in aqueous solutions. The presence of gelatin in the solution affects the early processes, via complexation of Ag+ ions with the amino acid moieties of the gelatin. The ratio of Ag+ to gelatin chains predetermines the kinetic consequences to the agglomeration processes. This ratio may accelerate or inhibit any of the processes that involve silver ions (reduction as well as growth). The complexation reduces somewhat the rate of reduction by hydrated electrons. However, when all the ions are complexed to the gelatin, the agglomeration may become very fast; at the extreme the agglomeration rate is determined by the rate of reduction. Some of the small Ag-n(m+) bind to the gelatin stronger than Ag+ ions. Excess silver ions enhance the stability of smaller transient clusters in the presence of gelatin. Three long-lived aggregates of different sizes are stabilized by the gelatin upon complete reduction of the silver ions. C1 ARGONNE NATL LAB, DIV CHEM, ARGONNE, IL 60439 USA. CONCORDIA UNIV, MONTREAL H3G 1M8, PQ, CANADA. RI Kennepohl, Pierre/B-2096-2009 OI Kennepohl, Pierre/0000-0003-3408-9157 NR 15 TC 74 Z9 74 U1 1 U2 5 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 0743-7463 J9 LANGMUIR JI Langmuir PD SEP PY 1994 VL 10 IS 9 BP 3018 EP 3022 DI 10.1021/la00021a026 PG 5 WC Chemistry, Multidisciplinary; Chemistry, Physical; Materials Science, Multidisciplinary SC Chemistry; Materials Science GA PH964 UT WOS:A1994PH96400026 ER PT J AU TOBIN, KW AF TOBIN, KW TI MACHINE-VISION EXPERTISE CAN LEAD TO INDUSTRIAL SUCCESS SO LASER FOCUS WORLD LA English DT Article AB Joint ventures strive for competitive edge with machine-vision research and development. RP TOBIN, KW (reprint author), OAK RIDGE NATL LAB,ADV COMPUTAT & MACHINE VIS GRP,POB 2008,BLDG 3546,MS-6011,OAK RIDGE,TN 37831, USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU PENNWELL PUBL CO PI NASHUA PA 5TH FLOOR TEN TARA BOULEVARD, NASHUA, NH 03062-2801 SN 0740-2511 J9 LASER FOCUS WORLD JI Laser Focus World PD SEP PY 1994 VL 30 IS 9 BP 115 EP 119 PG 5 WC Optics SC Optics GA PG336 UT WOS:A1994PG33600030 ER PT J AU BURTON, HD AF BURTON, HD TI AMERICAN WOMEN IN SCIENCE - A BIOGRAPHICAL DICTIONARY - BAILEY,MJ SO LIBRARY JOURNAL LA English DT Book Review RP BURTON, HD (reprint author), LAWRENCE LIVERMORE NATL LAB,LIVERMORE,CA 94550, USA. NR 1 TC 0 Z9 0 U1 0 U2 0 PU BOWKER MAGAZINE GROUP CAHNERS MAGAZINE DIVISION PI NEW YORK PA 249 W 17TH ST, NEW YORK, NY 10011 SN 0363-0277 J9 LIBR J JI Libr. J. PD SEP 1 PY 1994 VL 119 IS 14 BP 168 EP & PG 0 WC Information Science & Library Science SC Information Science & Library Science GA PE175 UT WOS:A1994PE17500019 ER PT J AU STALLINGS, RL DEAVEN, LL AF STALLINGS, RL DEAVEN, LL TI A MOUSE MONOCHROMOSOME-8 SOMATIC-CELL HYBRID - A REAGENT FOR CHROMOSOME-8 ISOLATION SO MAMMALIAN GENOME LA English DT Note ID LIBRARIES; MAP C1 LOS ALAMOS NATL LAB,CTR HUMAN GENOME STUDIES,LOS ALAMOS,NM 87545. RP STALLINGS, RL (reprint author), UNIV PITTSBURGH,DEPT HUMAN GENET,PITTSBURGH,PA 15261, USA. RI Stallings, Raymond/A-7213-2008 NR 10 TC 2 Z9 2 U1 0 U2 0 PU SPRINGER VERLAG PI NEW YORK PA 175 FIFTH AVE, NEW YORK, NY 10010 SN 0938-8990 J9 MAMM GENOME JI Mamm. Genome PD SEP PY 1994 VL 5 IS 9 BP 572 EP 573 DI 10.1007/BF00354932 PG 2 WC Biochemistry & Molecular Biology; Biotechnology & Applied Microbiology; Genetics & Heredity SC Biochemistry & Molecular Biology; Biotechnology & Applied Microbiology; Genetics & Heredity GA PE646 UT WOS:A1994PE64600009 PM 8000142 ER PT J AU KEISER, JR DIAS, OC MAYOTTE, JR AF KEISER, JR DIAS, OC MAYOTTE, JR TI ANALYSIS OF PIPE FAILURE AT THE GREAT-PLAINS COAL-GASIFICATION PLANT SO MATERIALS CHARACTERIZATION LA English DT Article AB The rupture of a carbon steel elbow in the methanation area of the Great Plains Coal Gasification Plant resulted in a fire and plant shutdown. Failure studies consisted of an on-site inspection and an extensive laboratory examination that included light metallography, X-ray fluorescence, X-ray diffraction, chemical analyses, and electron spectroscopy for chemical analysis. It was concluded that operation of a heat exchanger under off-specification conditions contributed to higher than design temperatures, lower than design pressures, and higher than design concentrations of carbon dioxide and water in the exit line from a condensate separator. Together, these conditions produced high levels of carbonic acid and higher than design velocities resulting in severe corrosion of the carbon steel. C1 AMOCO OIL CO,TEXAS CITY,TX 77592. RP KEISER, JR (reprint author), OAK RIDGE NATL LAB,MARTIN MARIETTA ENERGY SYST INC,OAK RIDGE,TN 37831, USA. NR 9 TC 0 Z9 0 U1 0 U2 2 PU ELSEVIER SCIENCE INC PI NEW YORK PA 655 AVENUE OF THE AMERICAS, NEW YORK, NY 10010 SN 1044-5803 J9 MATER CHARACT JI Mater. Charact. PD SEP PY 1994 VL 33 IS 2 BP 147 EP 153 DI 10.1016/1044-5803(94)90077-9 PG 7 WC Materials Science, Multidisciplinary; Metallurgy & Metallurgical Engineering; Materials Science, Characterization & Testing SC Materials Science; Metallurgy & Metallurgical Engineering GA PD576 UT WOS:A1994PD57600008 ER PT J AU RAWL, DE WEST, SL WHEELER, DA LOUTHAN, MR AF RAWL, DE WEST, SL WHEELER, DA LOUTHAN, MR TI DEFECT CHARACTERIZATION IN PIPE-TO-PIPE WELDS IN LARGE-DIAMETER STAINLESS-STEEL PIPING SO MATERIALS CHARACTERIZATION LA English DT Article ID SOLIDIFICATION AB Metallurgical evaluation of pipe-to-pipe welds in large-diameter, Type 304 stainless-steel piping used to construct the moderator/coolant water systems for Savannah River Site reactors has demonstrated that small weld defects found in this 1950-vintage system do not compromise the integrity of the system. The weld defects were too small for detection by the preservice standard radiographic inspection, but were found through systematic ultrasonic testing and penetrant testing evaluations of piping that had been removed during upgrades to the piping system. The defects include lack of weld penetration, slag inclusions, and other weld metal discontinuities. These discontinuities typically did not propagate during more than 35 years of service. The defects examined were too small and isolated to degrade the mechanical properties of the pipe-to-pipe weldments and, therefore, did not compromise the integrity of the piping system. RP RAWL, DE (reprint author), WESTINGHOUSE SAVANNAH RIVER CO,SAVANNAH RIVER LAB,AIKEN,SC 29808, USA. NR 14 TC 1 Z9 1 U1 0 U2 3 PU ELSEVIER SCIENCE INC PI NEW YORK PA 655 AVENUE OF THE AMERICAS, NEW YORK, NY 10010 SN 1044-5803 J9 MATER CHARACT JI Mater. Charact. PD SEP PY 1994 VL 33 IS 2 BP 155 EP 162 DI 10.1016/1044-5803(94)90078-7 PG 8 WC Materials Science, Multidisciplinary; Metallurgy & Metallurgical Engineering; Materials Science, Characterization & Testing SC Materials Science; Metallurgy & Metallurgical Engineering GA PD576 UT WOS:A1994PD57600009 ER PT J AU OBRIEN, JR OESTERREICHER, H TAYLOR, RD AF OBRIEN, JR OESTERREICHER, H TAYLOR, RD TI EFFECTS OF GETTER ANNEALING AND CODOPING OF IRON AND ZINC IN YTTRIUM-BARIUM CUPRATES SO MATERIALS RESEARCH BULLETIN LA English DT Article DE CUPRATES; FE SUBSTITUTION; ZN SUBSTITUTION ID THERMAL TREATMENTS; FE CLUSTERS; YBA2(CU1-XFEX)3O6+Y AB This study explores issues connected with the complex structural and electronic behavior of partly substituted YBa2(Cu1-x-zFexZnz)3Oy when given special redox sequencing over varying times. For z=0 and x=0.03 conventional oxygenating slow cooling preparations (OP) yield tetragonal materials with T(c-mid)=59K. Getter annealing procedures using Gd to control the extent of reduction to y=6.1 at 1000K for 4 days followed by reoxidation at 700K for 1 hour yield orthorhombic materials with T(c-mid)=68K and improved superconducting volume fractions. The results are in line with expectations for the presence of ordered atomic size Fe clusters with these reducing preparations (RP). This redox sequence also reduces the paramagnetic Curie temperature from THETA(P)=-35 K to THETA(P)=-51 K for z=0, hinting at higher cluster Neel temperatures. When the getter annealed specimen is air annealed for prolonged times (50h) at 673 K, a broader T(c) transition develops and a slight decrease in the orthorhombic splitting is observed. This demonstrates that small rearrangements from properties of RP to OP are possible even at these low temperatures. Codoping to x = 0.03, z = 0.01 results in drastic reductions to T(c-mid) = 31 K for OP, beyond the one expected from individual contributions, while structural parameters do not change noticeably. This synergistic effect is also reflected in theta(P) and may have to do with a large proportion of Fe occupying the Cu(2) site. Results are discussed within models of inhomogeneous M distributions and oxygen chain order. C1 LOS ALAMOS NATL LAB,DIV PHYS,LOS ALAMOS,NM 87545. RP OBRIEN, JR (reprint author), UNIV CALIF SAN DIEGO,DEPT CHEM,LA JOLLA,CA 92093, USA. NR 9 TC 4 Z9 4 U1 0 U2 0 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD, ENGLAND OX5 1GB SN 0025-5408 J9 MATER RES BULL JI Mater. Res. Bull. PD SEP PY 1994 VL 29 IS 9 BP 981 EP 985 DI 10.1016/0025-5408(94)90059-0 PG 5 WC Materials Science, Multidisciplinary SC Materials Science GA PD122 UT WOS:A1994PD12200008 ER PT J AU WEGENG, RS DROST, MK AF WEGENG, RS DROST, MK TI DEVELOPING NEW MINIATURE ENERGY-SYSTEMS SO MECHANICAL ENGINEERING LA English DT Article RP WEGENG, RS (reprint author), PACIFIC NW LAB, RICHLAND, WA 99352 USA. NR 0 TC 5 Z9 6 U1 0 U2 0 PU ASME-AMER SOC MECHANICAL ENG PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 SN 0025-6501 J9 MECH ENG JI Mech. Eng. PD SEP PY 1994 VL 116 IS 9 BP 82 EP 85 PG 4 WC Engineering, Mechanical SC Engineering GA PG177 UT WOS:A1994PG17700022 ER PT J AU RILEY, RW AF RILEY, RW TI BEFORE THE SHOW STARTS SO MEDIA STUDIES JOURNAL LA English DT Discussion RP RILEY, RW (reprint author), US DOE,WASHINGTON,DC 20585, USA. NR 0 TC 1 Z9 1 U1 0 U2 0 PU COLUMBIA UNIV, FREEDOM FORUM MEDIA STUDIES CENTER PI NEW YORK PA FINANCIAL DEPT, 2950 BROADWAY, NEW YORK, NY 10027-7004 SN 1057-7416 J9 MEDIA STUD J JI Media Stud. J. PD FAL PY 1994 VL 8 IS 4 BP 1 EP 6 PG 6 WC Communication; Social Issues SC Communication; Social Issues GA RL471 UT WOS:A1994RL47100002 ER PT J AU CHANEY, EL CULLIP, TJ GABRIEL, TA AF CHANEY, EL CULLIP, TJ GABRIEL, TA TI MONTE-CARLO STUDY OF ACCELERATOR HEAD SCATTER SO MEDICAL PHYSICS LA English DT Article DE MONTE CARLO; HEAD SCATTER; COLLIMATOR FACTOR; EXTENDED SOURCE MODEL ID LINEAR ACCELERATORS; PHOTON-BEAM; ENERGY; OUTPUT; BACKSCATTER; DOSIMETRY AB The production of off-focus x rays in the head of a 6 MV linac has been investigated using the EGS4 Monte Carlo code. The purpose of the study was to identify the sources of off-focus radiation and the relative contribution for each source. Even though a particular energy and linac were modeled, the broad conclusions are expected to be general since the effects of head scatter are similar for most conventional head designs, regardless of manufacturer, energy, and model. The head components that were modeled include the exit window of the accelerating structure, target, beam stopper, flattening filter, monitor chamber, primary and secondary collimators, and air. Monoenergetic 6 MeV electrons were followed through the exit window, target, and beam stopper until all energy was expended. Primary- and higher-order x rays produced throughout the head were followed until they were either absorbed or passed through a plane at the isocenter. Sites of off-focus radiation were found to be diffusely distributed throughout the head, with the most intense sources being the primary collimator, flattening filter, and beam stopper. Data analysis shows that the collimator effect is determined primarily by the volume of the extended head-scatter source that is exposed to the point of measurement through the collimating system. The results of this study provide a rationale for developing extended source models to calculate the collimator factor for fields defined by arbitrary collimation. An additional advantage is an improvement in the agreement between measured and calculated isodose distributions. C1 OAK RIDGE NATL LAB,OAK RIDGE,TN 37831. RP CHANEY, EL (reprint author), UNIV N CAROLINA,CHAPEL HILL,NC 27599, USA. NR 22 TC 101 Z9 103 U1 0 U2 8 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 SEP PY 1994 VL 21 IS 9 BP 1383 EP 1390 DI 10.1118/1.597194 PG 8 WC Radiology, Nuclear Medicine & Medical Imaging SC Radiology, Nuclear Medicine & Medical Imaging GA PH393 UT WOS:A1994PH39300003 PM 7838048 ER PT J AU DAHMEN, U AF DAHMEN, U TI A COMPARISON BETWEEN 3 SIMPLE CRYSTALLOGRAPHIC PRINCIPLES OF PRECIPITATE MORPHOLOGY SO METALLURGICAL AND MATERIALS TRANSACTIONS A-PHYSICAL METALLURGY AND MATERIALS SCIENCE LA English DT Article; Proceedings Paper CT Pacific Rim Conference on the Role of Shear and Diffusion in the Formation of Plate-Shaped Transformation Products CY DEC 18-22, 1992 CL KONA, HI SP ASM INT, PHASE TRANSFORMAT COMM ID FCC-BCC BOUNDARIES; CR ALLOY; INVARIANT LINE; CU; GROWTH AB The connection between the optimum shape and orientation relationship of precipitates in a solid is examined. Three simple criteria for precipitate morphology are compared and illustrated schematically: the principle that precipitate dimensions tend to be inverse to the magnitude of the transformation strain; the postulate that precipitates are bounded by unrotated planes (eigenplanes); and the proposal that interfaces are parallel to the planes of three independent dislocation loop arrays necessary to accommodate the transformation strain completely. These principles are illustrated for different orientation relationships, and it is shown that special features are displayed by invariant-line precipitates. The implications of these criteria for experimental studies of precipitate morphologies are discussed and their predictions compared with results from a recent study of lath-shaped precipitates in Cu-Cr alloys. RP DAHMEN, U (reprint author), LAWRENCE BERKELEY LAB,NATL CTR ELECTRON MICROSCOPY,BERKELEY,CA 94720, USA. NR 21 TC 26 Z9 26 U1 0 U2 2 PU MINERALS METALS MATERIALS SOC PI WARRENDALE PA 420 COMMONWEALTH DR, WARRENDALE, PA 15086 SN 1073-5623 J9 METALL MATER TRANS A JI Metall. Mater. Trans. A-Phys. Metall. Mater. Sci. PD SEP PY 1994 VL 25 IS 9 BP 1857 EP 1863 DI 10.1007/BF02649033 PG 7 WC Materials Science, Multidisciplinary; Metallurgy & Metallurgical Engineering SC Materials Science; Metallurgy & Metallurgical Engineering GA PC476 UT WOS:A1994PC47600006 ER PT J AU JULL, AJT DONAHUE, DJ REEDY, RC MASARIK, J AF JULL, AJT DONAHUE, DJ REEDY, RC MASARIK, J TI A C-14 DEPTH PROFILE IN THE L5 CHONDRITE KNYAHINYA SO METEORITICS LA English DT Note ID COSMOGENIC NUCLIDES; STONY METEORITES; PRODUCTION-RATES; TERRESTRIAL AGE; C-14; ACCELERATOR AB We report on a series of measurements of C-14 in samples of the L-chondrite Knyahinya, as a function of depth. The results show C-14 concentrations ranging from 37 to 58 dpm/kg. These measurements are compared to the levels of Ne-21, Be-10 and noble-gas ratios in this meteorite reported by Graf et al (1990). We also compare the C-14 data to the expected profile based on two sets of model calculations. The behavior of this radioisotope with depth is similar to that expected from the models, and good agreement with the profiles of other nuclides is also observed. C1 LOS ALAMOS NATL LAB,GRP SST9,LOS ALAMOS,NM 87545. RP JULL, AJT (reprint author), UNIV ARIZONA,NSF ARIZONA ACCELERATOR MASS SPECT FACIL,TUCSON,AZ 85721, USA. NR 26 TC 21 Z9 21 U1 0 U2 0 PU METEORITICAL SOC PI FAYETTEVILLE PA DEPT CHEMISTRY/BIOCHEMISTRY, UNIV ARKANSAS, FAYETTEVILLE, AR 72701 SN 0026-1114 J9 METEORITICS JI Meteoritics PD SEP PY 1994 VL 29 IS 5 BP 649 EP 651 PG 3 WC Geochemistry & Geophysics SC Geochemistry & Geophysics GA PF653 UT WOS:A1994PF65300012 ER PT J AU KEMP, PF AF KEMP, PF TI A PHILOSOPHY OF METHODS DEVELOPMENT - THE ASSIMILATION OF NEW METHODS AND INFORMATION INTO AQUATIC MICROBIAL ECOLOGY SO MICROBIAL ECOLOGY LA English DT Article AB Emerging methodologies can be used to provide a strong basic understanding of the diversity of microbial behavior and interactions. However, these new methods should be thoroughly and rigorously validated under controlled conditions before being extended to uncontrolled field conditions. Data based on novel approaches are likely to provide insights that are not easily related to existing information based on conventional methodologies. As an example, measurements of the ribosomal RNA (rRNA) content of bacteria show similar spatial patterns as measurements of thymidine incorporation into DNA and leucine incorporation into protein. However, the spatial patterns are not identical, and these parameters are not equally intercorrelated nor equally predictable from basic oceanographic data. Therefore, rRNA content measurements provide a new dimension of information that can be used to explore the relationship of bacteria to their environment, complementing the information obtained from conventional methods. RP KEMP, PF (reprint author), BROOKHAVEN NATL LAB,UPTON,NY 11973, USA. RI Kemp, Paul/G-2291-2011 OI Kemp, Paul/0000-0001-8947-4349 NR 1 TC 6 Z9 6 U1 0 U2 0 PU SPRINGER VERLAG PI NEW YORK PA 175 FIFTH AVE, NEW YORK, NY 10010 SN 0095-3628 J9 MICROBIAL ECOL JI Microb. Ecol. PD SEP-OCT PY 1994 VL 28 IS 2 BP 159 EP 162 DI 10.1007/BF00166804 PG 4 WC Ecology; Marine & Freshwater Biology; Microbiology SC Environmental Sciences & Ecology; Marine & Freshwater Biology; Microbiology GA PN362 UT WOS:A1994PN36200007 PM 24186441 ER PT J AU WHITE, DC AF WHITE, DC TI IS THERE ANYTHING ELSE YOU NEED TO UNDERSTAND ABOUT THE MICROBIOTA THAT CANNOT BE DERIVED FROM ANALYSIS OF NUCLEIC-ACIDS SO MICROBIAL ECOLOGY LA English DT Article ID FATTY-ACIDS; SEDIMENTS; TRANS RP WHITE, DC (reprint author), UNIV TENNESSEE,OAK RIDGE NATL LAB,CTR ENVIRONM BIOTECHNOL,10515 RES DR,SUITE 300,KNOXVILLE,TN 37932, USA. NR 14 TC 33 Z9 34 U1 0 U2 3 PU SPRINGER VERLAG PI NEW YORK PA 175 FIFTH AVE, NEW YORK, NY 10010 SN 0095-3628 J9 MICROBIAL ECOL JI Microb. Ecol. PD SEP-OCT PY 1994 VL 28 IS 2 BP 163 EP 166 DI 10.1007/BF00166805 PG 4 WC Ecology; Marine & Freshwater Biology; Microbiology SC Environmental Sciences & Ecology; Marine & Freshwater Biology; Microbiology GA PN362 UT WOS:A1994PN36200008 PM 24186442 ER PT J AU ASHBY, C AF ASHBY, C TI MATERIALS, PROCESS SCIENCE AND TECHNOLOGY AT SANDIAS CENTER-FOR-COMPOUND-SEMICONDUCTOR-TECHNOLOGY - CCST SO MICROELECTRONICS JOURNAL LA English DT Article AB We present the first in a series of articles describing some of the current work underway at some of the world's leading R&D institutions. We begin with a report from the Center for Compound Semiconductor Technology (CCST) at Sandia National Laboratories in Albuquerque, New Mexico, USA. Advances in materials and process science and technology ave providing the crucial foundation for advances in photonic and electronic circuits and systems. RP ASHBY, C (reprint author), SANDIA NATL LABS,CTR COMPOUND SEMICOND TECHNOL,POB 5800,ALBUQUERQUE,NM 87185, USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU ELSEVIER ADVANCED TECHNOLOGY PI OXFORD PA OXFORD FULFILLMENT CENTRE THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD, OXON, ENGLAND OX5 1GB SN 0026-2692 J9 MICROELECTR J JI Microelectron. J. PD SEP PY 1994 VL 25 IS 6 BP R5 EP R12 PG 8 WC Engineering, Electrical & Electronic; Nanoscience & Nanotechnology SC Engineering; Science & Technology - Other Topics GA PT986 UT WOS:A1994PT98600002 ER PT J AU ZHANG, X JOY, D AF ZHANG, X JOY, D TI FABRICATION OF AU/P-SI SCHOTTKY-BARRIER FOR EBIC STUDY SO MICROSCOPY RESEARCH AND TECHNIQUE LA English DT Article DE SCANNING ELECTRON MICROSCOPE; DISLOCATIONS; MONTE CARLO SIMULATION ID SILICON; HEIGHT AB A simple method for the fabrication of a Au/p-Si Schottky barrier suitable for electron beam induced current (EBIC) study has been developed. The mechanical and electrical properties of the fabricated Au/p-Si Schottky barriers have been tested, and EBIC measurements of the dislocation contrast have been conducted using the fabricated Schottky barriers. (C) 1994 Wiley-Liss, Inc. C1 UNIV TENNESSEE,ELECTRON MICROSCOPE FACIL,KNOXVILLE,TN 37996. OAK RIDGE NATL LAB,DIV MET & CERAM,OAK RIDGE,TN 37831. NR 21 TC 0 Z9 0 U1 0 U2 5 PU WILEY-LISS PI NEW YORK PA DIV JOHN WILEY & SONS INC 605 THIRD AVE, NEW YORK, NY 10158-0012 SN 1059-910X J9 MICROSC RES TECHNIQ JI Microsc. Res. Tech. PD SEP 1 PY 1994 VL 29 IS 1 BP 47 EP 53 DI 10.1002/jemt.1070290107 PG 7 WC Anatomy & Morphology; Biology; Microscopy SC Anatomy & Morphology; Life Sciences & Biomedicine - Other Topics; Microscopy GA PF020 UT WOS:A1994PF02000006 PM 8000084 ER PT J AU CHAIYAROJ, SC COPPEL, RL MAGOWAN, C BROWN, GV AF CHAIYAROJ, SC COPPEL, RL MAGOWAN, C BROWN, GV TI A PLASMODIUM-FALCIPARUM ISOLATE WITH A CHROMOSOME-9 DELETION EXPRESSES A TRYPSIN-RESISTANT CYTOADHERENCE MOLECULE SO MOLECULAR AND BIOCHEMICAL PARASITOLOGY LA English DT Article DE PLASMODIUM FALCIPARUM; CHROMOSOME 9 DELETION; TRYPSIN RESISTANCE; PFEMP-1; CYTOADHERENCE; ANTIGENIC VARIATION ID INFECTED ERYTHROCYTES; PARASITIZED ERYTHROCYTES; MEMBRANE GLYCOPROTEIN; ADHESION MOLECULE-1; CEREBRAL MALARIA; SEQUESTRATION; ANTIGEN; SURFACE; IDENTIFICATION; RECEPTOR AB Sequestration of Plasmodium falciparum infected erythrocytes in the cerebral circulation is strongly implicated in the pathogenesis of cerebral malaria. From previous studies it was postulated that genes essential for cytoadherence were located on the right arm of chromosome 9 as P. falciparum isolates with a deletion in this region lost the capacity to cytoadhere vitro and no longer expressed Plasmodium falciparum erythrocyte membrane protein-1 (PfEMP-1) on the surface of the infected cells. We have selected a P. falciparum isolate from Papua New guinea for high levels of cytoadherence to human umbilical vein endothelial cells (HUVECs) and have shown that the cloned parasite has several novel properties related cytoadherence. The cloned parasite adheres to HUVECs, does not bind to melanoma cells, and expresses a surface molecule with most properties of PfEMP-1, despite a deletion in the right arm of chromosome 9. Interestingly, the surface expressed PfEMP-1 in this strain is resistant to trypsin treatment and infected cells continue to cytoadhere after trypsin digestion at a concentration of 100 mu g ml(-1). The receptor on HUVECs for the cloned parasite lines is a molecule different from any previously described, as parasitized cells do not adhere to soluble intercellular adhesion molecule 1, thrombospondin, vascular cell adhesion molecule 1, E-selectin or P-selectin, nor to CD36. Our work, taken together with the results from previous studies, suggest that the ability of parasites to cytoadhere is encoded in at least two distinct genome locations in the parasite, and the diversity of receptor-ligand interaction is greater than previously described. C1 UNIV CALIF BERKELEY,LAWRENCE BERKELEY LAB,BERKELEY,CA 94720. RP CHAIYAROJ, SC (reprint author), ROYAL MELBOURNE HOSP,WALTER & ELIZA HALL INST MED RES,MELBOURNE,VIC 3050,AUSTRALIA. RI Coppel, Ross/A-6626-2008 OI Coppel, Ross/0000-0002-4476-9124 FU NIDDK NIH HHS [DK 32094-10] NR 34 TC 19 Z9 19 U1 0 U2 0 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0166-6851 J9 MOL BIOCHEM PARASIT JI Mol. Biochem. Parasitol. PD SEP PY 1994 VL 67 IS 1 BP 21 EP 30 DI 10.1016/0166-6851(94)90092-2 PG 10 WC Biochemistry & Molecular Biology; Parasitology SC Biochemistry & Molecular Biology; Parasitology GA PH249 UT WOS:A1994PH24900003 PM 7838180 ER PT J AU MICHAEL, P AF MICHAEL, P TI ESTIMATING ADVECTIVE TENDENCIES FROM FIELD-MEASUREMENTS SO MONTHLY WEATHER REVIEW LA English DT Note ID DIVERGENCE AB The ability to estimate horizontal advective tendencies of environmental variables from measurements at a finite set of observation points has been evaluated. The observation points include a central point plus from three to six boundary points at a mean distance of R(0). Two methods of estimation were considered: either by a numerical approximation to the flux line integral, or by integrating a quadratic fit to the field function (the latter if there are five of more boundary points). Errors arise from random instrument errors (or turbulent fluctuations) and because of truncation errors. The latter results from a mismatch between the spatial distribution of the field being considered and the assumptions underlying the approximation algorithm. Both types of errors were considered. Random errors were considered using standard theory for the propagation of errors. Terms of the Fourier series were used as test functions to study truncation errors. The standard against which estimates were evaluated was multipoint numerical integrations. For truncation errors, the significant result is that the use of a triangle of boundary points yields estimates close to 10% of the exact value only for a wavelength greater than about 20R(0); if cells have radius of 100 km, that would be a wavelength of 2000 km; for a square, the estimates are better than 10% at a wavelength of about 7R(0) (700 km); and for a pentagon, the estimates are less than 10% for the smallest nonaliasing wavelength. For this application, the use of a quadratic fit added little to accuracy; for a symmetrical array of points, the quadratic term does not contribute to the advective tendency. When one considers joint random and truncation errors, the general result is that truncation errors are more important than random errors for small wavelengths, and the reverse for large wavelengths. The results indicate that there is a substantial gain in going from three to four or five boundary points; the improvement for each further increment is less dramatic. It is recommended that simple algorithms be augmented by the use of remotely sensed finescale observations of surrogate and by occasional periods of observations at higher spatial density. RP MICHAEL, P (reprint author), BROOKHAVEN NATL LAB,DIV OCEANOG & ATMOSPHER SCI,BLDG 318,UPTON,NY 11973, USA. NR 9 TC 1 Z9 1 U1 0 U2 0 PU AMER METEOROLOGICAL SOC PI BOSTON PA 45 BEACON ST, BOSTON, MA 02108-3693 SN 0027-0644 J9 MON WEATHER REV JI Mon. Weather Rev. PD SEP PY 1994 VL 122 IS 9 BP 2202 EP 2209 DI 10.1175/1520-0493(1994)122<2202:EATFFM>2.0.CO;2 PG 8 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA PE318 UT WOS:A1994PE31800015 ER PT J AU SELDEN, JR DOLBEARE, F CLAIR, JH MILLER, JE MCGETTIGAN, K DIJOHN, JA DYSART, GR DELUCA, JG AF SELDEN, JR DOLBEARE, F CLAIR, JH MILLER, JE MCGETTIGAN, K DIJOHN, JA DYSART, GR DELUCA, JG TI VALIDATION OF A FLOW CYTOMETRIC IN-VITRO DNA-REPAIR (UDS) ASSAY IN RAT HEPATOCYTES SO MUTATION RESEARCH-DNA REPAIR LA English DT Article DE AUTORADIOGRAPHY; DNA REPAIR; FLOW CYTOMETRY; RAT HEPATOCYTES; UNSCHEDULED DNA SYNTHESIS ID HUMAN-FIBROBLASTS; PRIMARY CULTURES; HUMAN-CELLS; BROMODEOXYURIDINE; CARCINOGENS; RADIATION; HAMSTER; AGENTS; MOUSE; LIVER AB An in vitro flow cytometric (FCM) DNA repair assay has been developed and validated by comparison to conventional autoradiography (ARG). Both assays measure unscheduled DNA synthesis (UDS). Cultures of hepatocytes from young male Sprague-Dawley rats were exposed to a battery of 26 chemicals plus bromodeoxyuridine (BrdUrd) or H-3-thymidine (H-3-dT) for 18-20 h before harvest. Selection of test chemicals was based upon both their genotoxicity classifications and carcinogenicity bioassay results in male rats. DNA repair in chemically treated cultures was detected flow cytometrically by measuring the uptake of BrdUrd in non-replicating (G(1), G(2), mitotic and 4C) cells. Intracellular levels of incorporated BrdUrd were visualized by immunochemical labeling with fluorescein isothiocyanate (FITC), and total cellular DNA content was simultaneously estimated by counterstaining samples with the nucleic acid intercalator, propidium iodide (PI). Information was obtained from 10(4) cells/sample. Since repairing cells incorporate significantly less BrdUrd per unit of time than replicating cells, low intensity BrdUrd-FITC fluorescent signals from repairing cells are readily discriminated from high intensity signals from replicating cells when displayed on linear univariate histograms. Further distinction between repairing and replicating cells was achieved by displaying the DNA contents of all cells on linear bivariate histograms. Thus, repairing cells were resolved without subjecting these cultures to agents which suppress replicative synthesis (e.g., hydroxyurea). Results from these concurrent FCM and ARG investigations include the following: (1) conclusions (DNA repair positive or negative) were in agreement, with one exception, cinnamyl anthranilate, for which cytotoxic doses produced a positive FCM response, but lack of intact hepatocytes in parallel ARG preparations prevented analysis; (2) similar sensitivities for most of the positive chemicals were reported; (3) a high correlation (85%) exists between the reported genotoxicity classification and these DNA repair results in the absence of overt cytotoxicity; (4) a poor correlation exists between these DNA repair results and hepatocarcinogenesis (only 4/11 liver carcinogens tested positive) or overall carcinogenesis in the male rat (only 9/21 carcinogens tested positive). This FCM assay provides a rapid, sensitive, safe and reliable means of identifying agents which induce DNA repair in mammalian cells. C1 MERCK SHARP & DOHME LTD,RES LABS,DEPT BIOMETR RES,W POINT,PA 19486. LAWRENCE LIVERMORE NATL LAB,DIV BIOMED SCI,LIVERMORE,CA 94550. RP SELDEN, JR (reprint author), MERCK SHARP & DOHME LTD,RES LABS,DEPT SAFETY ASSESSMENT,W POINT,PA 19486, USA. NR 30 TC 22 Z9 22 U1 0 U2 0 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0921-8777 J9 MUTAT RES-DNA REPAIR JI Mutat. Res.-DNA Repair PD SEP PY 1994 VL 315 IS 2 BP 147 EP 167 DI 10.1016/0921-8777(94)90015-9 PG 21 WC Biotechnology & Applied Microbiology; Genetics & Heredity; Toxicology SC Biotechnology & Applied Microbiology; Genetics & Heredity; Toxicology GA PM077 UT WOS:A1994PM07700007 PM 7520997 ER PT J AU CHICK, LA MAUPIN, GD PEDERSON, LR AF CHICK, LA MAUPIN, GD PEDERSON, LR TI GLYCINE-NITRATE SYNTHESIS OF A CERAMIC-METAL COMPOSITE SO NANOSTRUCTURED MATERIALS LA English DT Proceedings Paper CT Engineering-Foundation Conference on Vapor Phase Manufacture of Materials CY JAN 16-21, 1994 CL KONA, HI SP ENGN FDN ID COMBUSTION SYNTHESIS; MATRIX COMPOSITES; POWDERS; YBA2CU3O7-X C1 BATTELLE MEM INST,PACIFIC NW LABS,RICHLAND,WA 99352. NR 25 TC 24 Z9 25 U1 0 U2 16 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD, ENGLAND OX5 1GB SN 0965-9773 J9 NANOSTRUCT MATER JI Nanostruct. Mater. PD SEP PY 1994 VL 4 IS 5 BP 603 EP 615 DI 10.1016/0965-9773(94)90070-1 PG 13 WC Materials Science, Multidisciplinary SC Materials Science GA PC138 UT WOS:A1994PC13800016 ER PT J AU GISLER, G AF GISLER, G TI ASTROPHYSICS - A GALACTIC SPEED RECORD SO NATURE LA English DT Editorial Material RP GISLER, G (reprint author), LOS ALAMOS NATL LAB,LOS ALAMOS,NM 87544, USA. NR 7 TC 5 Z9 5 U1 0 U2 0 PU MACMILLAN MAGAZINES LTD PI LONDON PA PORTERS SOUTH, 4 CRINAN ST, LONDON, ENGLAND N1 9XW SN 0028-0836 J9 NATURE JI Nature PD SEP 1 PY 1994 VL 371 IS 6492 BP 18 EP 18 DI 10.1038/371018a0 PG 1 WC Multidisciplinary Sciences SC Science & Technology - Other Topics GA PE381 UT WOS:A1994PE38100026 ER PT J AU ATTAWAY, SW HEINSTEIN, MW SWEGLE, JW AF ATTAWAY, SW HEINSTEIN, MW SWEGLE, JW TI COUPLING OF SMOOTH PARTICLE HYDRODYNAMICS WITH THE FINITE-ELEMENT METHOD SO NUCLEAR ENGINEERING AND DESIGN LA English DT Article AB A gridless technique called smooth particle hydrodynamics (SPH) has been coupled with the transient dynamics finite element code PRONTO. In this paper, a new weighted residual derivation for the SPH method will be presented, and the methods used to embed SPH within PRONTO will be outlined. Example SPH PRONTO calculations will also be presented. One major difficulty associated with the Lagrangian finite element method is modeling materials with no shear strength; for example, gases, fluids and explosive biproducts. Typically, these materials can be modeled for only a short time with a Lagrangian finite element code. Large distortions cause tangling of the mesh, which will eventually lead to numerical difficulties, such as negative element area or ''bow tie'' elements. Remeshing will allow the problem to continue for a short while, but the large distortions can prevent a complete analysis. SPH is a gridless Lagrangian technique. Requiring no mesh, SPH has the potential to model material fracture, large shear flows and penetration. SPH computes the strain rate and the stress divergence based on the nearest neighbors of a particle, which are determined using an efficient particle-sorting technique. Embedding the SPH method within PRONTO allows part of the problem to be modeled with quadrilateral finite elements, while other parts are modeled with the gridless SPH method. SPH elements are coupled to the quadrilateral elements through a contact-like algorithm. C1 SANDIA NATL LABS,DEPT ENGN MECH P MAT MODELING,ALBUQUERQUE,NM 87185. SANDIA NATL LABS,DEPT SOLID & STRUCT MECH,ALBUQUERQUE,NM 87185. RP ATTAWAY, SW (reprint author), SANDIA NATL LABS,DEPT COMPUTAT MECH & VISUALIZAT,ALBUQUERQUE,NM 87185, USA. NR 11 TC 60 Z9 74 U1 1 U2 6 PU ELSEVIER SCIENCE SA LAUSANNE PI LAUSANNE 1 PA PO BOX 564, 1001 LAUSANNE 1, SWITZERLAND SN 0029-5493 J9 NUCL ENG DES JI Nucl. Eng. Des. PD SEP PY 1994 VL 150 IS 2-3 BP 199 EP 205 DI 10.1016/0029-5493(94)90136-8 PG 7 WC Nuclear Science & Technology SC Nuclear Science & Technology GA PN878 UT WOS:A1994PN87800002 ER PT J AU HOFFMAN, EL AMMERMAN, DJ AF HOFFMAN, EL AMMERMAN, DJ TI BENCHMARK STUDY OF 2-DIMENSIONAL AND 3-DIMENSIONAL, FINITE-ELEMENT CALCULATIONS, SIMULATING DYNAMIC PULSE BUCKLING TESTS OF CYLINDRICAL-SHELLS UNDER AXIAL IMPACT SO NUCLEAR ENGINEERING AND DESIGN LA English DT Article AB A series of tests investigating dynamic pulse buckling of a cylindrical shell under axial impact is compared with several finite element simulations of the event. The purpose of the study is to compare the performance of the various analysis codes and element types with respect to a problem which is applicable to radioactive material transport packages, and ultimately to develop a benchmark problem to qualify finite element analysis codes for the transport package design industry. Although the finite element codes used in this study utilize similar element technology, there are differences in the numerical solutions. Furthermore, this study demonstrates that experiments-which are typically accepted as the ''correct'' answer-can have multiple results because of design sensitivities. Multiplicity of experimental results suggests that experiments performed for numerical benchmarks should first be numerically evaluated for such sensitivities. C1 SANDIA NATL LABS,DEPT TRANSPORTAT SYST TECHNOL,ALBUQUERQUE,NM 87185. RP HOFFMAN, EL (reprint author), SANDIA NATL LABS,DEPT ENGN MECH P MAT MODELING,ALBUQUERQUE,NM 87185, USA. NR 9 TC 1 Z9 1 U1 0 U2 1 PU ELSEVIER SCIENCE SA LAUSANNE PI LAUSANNE 1 PA PO BOX 564, 1001 LAUSANNE 1, SWITZERLAND SN 0029-5493 J9 NUCL ENG DES JI Nucl. Eng. Des. PD SEP PY 1994 VL 150 IS 2-3 BP 243 EP 251 DI 10.1016/0029-5493(94)90141-4 PG 9 WC Nuclear Science & Technology SC Nuclear Science & Technology GA PN878 UT WOS:A1994PN87800007 ER PT J AU CLARKSEAN, R SOLBRIG, C AF CLARKSEAN, R SOLBRIG, C TI MINIMIZATION OF THE EFFECT OF ERRORS IN APPROXIMATE RADIATION VIEW FACTORS SO NUCLEAR ENGINEERING AND DESIGN LA English DT Article; Proceedings Paper CT 6th International Topical Meeting on Nuclear Reactor Thermal-Hydraulics (NURETH-6) CY OCT 05-08, 1993 CL GRENOBLE, FRANCE SP AMER NUCL SOC, FRENCH SECT, AMER NUCL SOC, THERMAL HYDRAUL DIV, SOC FRANCAISE ENERGIE NUCL, EUROPEAN NUCL SOC, INT ATOM ENERGY AGCY, OECD NUCL ENERGY AGCY, ATOM ENERGY SOC JAPAN, CEA, EDF, FRAMATOME AB The maximum temperature of irradiated fuel rods in storage containers was investigated, taking account only for radiation heat transfer. Estimating view factors is often easy but the emphasis is often on calculating the quadruple integrals exactly. Selecting different view factors in the view factor matrix as independent, yields somewhat different view factor matrices. In this study, errors of 10%-20% in view factors produce small errors in the temperature, which are well within the uncertainty resulting from the surface emissivities uncertainty. However, the enclosure and reciprocity principles must be strictly observed, or large errors in the temperatures and wall heat flux are observed (up to a factor of 3). In addition to being an aid for calculating the dependent view factors, satisfying these principles, particularly reciprocity, is more important than the calculation accuracy of the view factors. Comparison with experiment showed that the results of the radiation calculation were definitely conservative, as desired, despite the approximations of the view factors. RP CLARKSEAN, R (reprint author), ARGONNE NATL LAB,DIV TECHNOL DEV,POB 2528,IDAHO FALLS,ID 83403, USA. NR 5 TC 1 Z9 1 U1 0 U2 1 PU ELSEVIER SCIENCE SA LAUSANNE PI LAUSANNE 1 PA PO BOX 564, 1001 LAUSANNE 1, SWITZERLAND SN 0029-5493 J9 NUCL ENG DES JI Nucl. Eng. Des. PD SEP PY 1994 VL 149 IS 1-3 BP 431 EP 440 DI 10.1016/0029-5493(94)90308-5 PG 10 WC Nuclear Science & Technology SC Nuclear Science & Technology GA PF964 UT WOS:A1994PF96400042 ER PT J AU TREBULES, V WILLIAMS, J AF TREBULES, V WILLIAMS, J TI MPC - WHY USDOE IS PURSUING THE CONCEPT SO NUCLEAR ENGINEERING INTERNATIONAL LA English DT Article RP TREBULES, V (reprint author), US DOE,OFF CIVILIAN RADIOACT WASTE MANAGEMENT,1000 INDEPENDENCE AVE SW,WASHINGTON,DC 20585, USA. NR 0 TC 1 Z9 1 U1 0 U2 0 PU REED BUSINESS PUBLISHING LTD PI SUTTON PA QUADRANT HOUSE THE QUADRANT, SUTTON, SURREY, ENGLAND SM2 5AS SN 0029-5507 J9 NUCL ENG INT JI Nucl. Eng. Int. PD SEP PY 1994 VL 39 IS 482 BP 36 EP 39 PG 4 WC Nuclear Science & Technology SC Nuclear Science & Technology GA PH309 UT WOS:A1994PH30900008 ER PT J AU KESSEL, CE AF KESSEL, CE TI BOOTSTRAP CURRENT IN A TOKAMAK SO NUCLEAR FUSION LA English DT Article ID NEOCLASSICAL TRANSPORT-THEORY; TOROIDAL CONFINEMENT SYSTEMS; NEUTRAL INJECTION; PLASMA TRANSPORT; MULTISPECIES PLASMA; ASPECT-RATIO; REGIME AB The bootstrap current in a tokamak is examined by implementing the Hirshman-Sigmar model and comparing the predicted current profiles with those from two popular approximations. The dependences of the bootstrap current profile on the plasma properties are illustrated. The implications for steady state tokamaks are presented through two constraints; the pressure profile must be peaked and beta(p) must be kept below a critical value. RP KESSEL, CE (reprint author), PRINCETON UNIV,PRINCETON PLASMA PHYS LAB,PRINCETON,NJ 08544, USA. NR 36 TC 54 Z9 57 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 SEP PY 1994 VL 34 IS 9 BP 1221 EP 1238 DI 10.1088/0029-5515/34/9/I04 PG 18 WC Physics, Fluids & Plasmas SC Physics GA PT022 UT WOS:A1994PT02200004 ER PT J AU BUDNY, RV AF BUDNY, RV TI A STANDARD DT SUPERSHOT SIMULATION SO NUCLEAR FUSION LA English DT Article ID NEUTRAL-BEAM INJECTION; TOKAMAK; TFTR AB A simulation of an anticipated TFTR deuterium-tritium supershot is described. The simulation is based on a reproducible, high performance, long duration D-only supershot. The TRANSP plasma analysis code is used to model fast ion (D, T and alpha) parameters, including their distributions in energy and pitch angle. RP BUDNY, RV (reprint author), PRINCETON UNIV,PLASMA PHYS LAB,PRINCETON,NJ 08544, USA. NR 21 TC 141 Z9 142 U1 0 U2 4 PU INT ATOMIC ENERGY AGENCY PI VIENNA PA WAGRAMERSTRASSE 5, PO BOX 100, A-1400 VIENNA, AUSTRIA SN 0029-5515 J9 NUCL FUSION JI Nucl. Fusion PD SEP PY 1994 VL 34 IS 9 BP 1247 EP 1262 DI 10.1088/0029-5515/34/9/I06 PG 16 WC Physics, Fluids & Plasmas SC Physics GA PT022 UT WOS:A1994PT02200006 ER PT J AU PARK, HK BELL, MG TANG, WM TAYLOR, G YAMADA, M BUDNY, RV MCCUNE, DC WIELAND, RM AF PARK, HK BELL, MG TANG, WM TAYLOR, G YAMADA, M BUDNY, RV MCCUNE, DC WIELAND, RM TI ROLE OF NEUTRAL-BEAM FUELING PROFILE IN ENERGY CONFINEMENT AND NEUTRON EMISSION ON TFTR SO NUCLEAR FUSION LA English DT Letter ID FUSION TEST REACTOR; TOKAMAK; PLASMAS AB The role of the neutral-beam fuelling profile in determining the stored energy and neutron emission in neutral-beam-heated discharges on TFTR is investigated. It is found that the neutral-beam fuelling profile is sensitive to both the magnitude and the shape of the electron density. The ion stored energy correlates well with the peaking of the neutral-beam fuelling profile, whereas the electron stored energy is insensitive to this parameter. The DD fusion neutron emission is also well correlated with the peaking of the neutral-beam fuelling profile. The derived empirical scalings of the ion stored energy and neutron yield include discharges from the L mode to the supershot regime. RP PARK, HK (reprint author), PRINCETON UNIV,PLASMA PHYS LAB,PRINCETON,NJ 08544, USA. RI Yamada, Masaaki/D-7824-2015 OI Yamada, Masaaki/0000-0003-4996-1649 NR 20 TC 13 Z9 13 U1 0 U2 2 PU INT ATOMIC ENERGY AGENCY PI VIENNA PA WAGRAMERSTRASSE 5, PO BOX 100, A-1400 VIENNA, AUSTRIA SN 0029-5515 J9 NUCL FUSION JI Nucl. Fusion PD SEP PY 1994 VL 34 IS 9 BP 1271 EP 1276 DI 10.1088/0029-5515/34/9/I08 PG 6 WC Physics, Fluids & Plasmas SC Physics GA PT022 UT WOS:A1994PT02200008 ER PT J AU BRETZ, NL AF BRETZ, NL TI MICROWAVE REFLECTOMETRY FOR FUSION PLASMA DIAGNOSTICS - REPORT ON THE IAEA TECHNICAL COMMITTEE MEETING HELD AT PRINCETON PLASMA PHYSICS LABORATORY, PRINCETON-UNIVERSITY, PRINCETON, NEW-JERSEY, UNITED-STATES-OF-AMERICA, 25-27 JANUARY 1994 SO NUCLEAR FUSION LA English DT Editorial Material RP BRETZ, NL (reprint author), PRINCETON UNIV,PRINCETON PLASMA PHYS LAB,PRINCETON,NJ 08544, USA. NR 0 TC 3 Z9 3 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 SEP PY 1994 VL 34 IS 9 BP 1283 EP 1288 DI 10.1088/0029-5515/34/9/410 PG 6 WC Physics, Fluids & Plasmas SC Physics GA PT022 UT WOS:A1994PT02200010 ER PT J AU MERCER, DJ MIKOLAS, D YURKON, J AUSTIN, SM BAZIN, D GAFF, S KASHY, E KATARIA, D WINFIELD, JS BETTS, R HENDERSON, D HALLIN, A LIU, M AF MERCER, DJ MIKOLAS, D YURKON, J AUSTIN, SM BAZIN, D GAFF, S KASHY, E KATARIA, D WINFIELD, JS BETTS, R HENDERSON, D HALLIN, A LIU, M TI APEX HEAVY-ION COUNTERS SO NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH SECTION A-ACCELERATORS SPECTROMETERS DETECTORS AND ASSOCIATED EQUIPMENT LA English DT Article; Proceedings Paper CT 3rd London Conference on Position Sensitive Detectors CY SEP 06-10, 1993 CL BRUNEL UNIV, LONDON, ENGLAND HO BRUNEL UNIV ID ELECTRON-SPECTROSCOPY; COLLISIONS; POSITRON; DETECTORS; PEAKS AB A large solid-angle array of low pressure multiwire proportional counters has been constructed as part of the Atlas Positron EXperiment (APEX). Eight three-element trapezoidal counters provide 360-degrees coverage in phi and 20-degrees-68-degrees coverage in theta. Angle sensitivity in theta is provided by a transmission-line delay cathode, while the segmentation provides angle sensitivity in phi. Sample data are presented from the 1450 MeV U-238 + Ta-181 reaction. C1 MICHIGAN STATE UNIV,NATL SUPERCONDUCTING CYCLOTRON LAB,E LANSING,MI 48824. ARGONNE NATL LAB,ARGONNE,IL 60439. QUEENS UNIV,KINGSTON K7L 3N6,ONTARIO,CANADA. NR 16 TC 1 Z9 1 U1 0 U2 0 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0168-9002 J9 NUCL INSTRUM METH A JI Nucl. Instrum. Methods Phys. Res. Sect. A-Accel. Spectrom. Dect. Assoc. Equip. PD SEP 1 PY 1994 VL 348 IS 2-3 BP 252 EP 255 DI 10.1016/0168-9002(94)90741-2 PG 4 WC Instruments & Instrumentation; Nuclear Science & Technology; Physics, Nuclear; Physics, Particles & Fields SC Instruments & Instrumentation; Nuclear Science & Technology; Physics GA PF645 UT WOS:A1994PF64500011 ER PT J AU BOROVICKROMANOV, A PESKOV, V AF BOROVICKROMANOV, A PESKOV, V TI CS BASED PHOTOCATHODES FOR GASEOUS DETECTORS SO NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH SECTION A-ACCELERATORS SPECTROMETERS DETECTORS AND ASSOCIATED EQUIPMENT LA English DT Article; Proceedings Paper CT 3rd London Conference on Position Sensitive Detectors CY SEP 06-10, 1993 CL BRUNEL UNIV, LONDON, ENGLAND HO BRUNEL UNIV ID LIGHT AB We demonstrate that some standard photocathodes (SbCs, GaAs(Cs), Au(Cs)) can be easily manufactured for use inside gaseous detectors. When filled with clean quenched gases such detectors have a quantum efficiency of a few percent in the visible region of the spectrum and can operate at a gain > 10(3). We tried to make these photocathodes more air stable by protecting their surfaces with a thin layer of CsI or liquid TMAE. The most air stable were photocathodes with a CsI protective layer. At wavelengths greater-than-or-equal-to 185 nm such photocathodes have the highest quantum efficiency among all known air stable photocathodes, including CsI. Gaseous detectors with such photocathodes can operate at a gain of 10(5). Results of the first tests of doped CsI photocathode are also presented. Possible fields of application of the new photocathodes are discussed. C1 FERMILAB NATL ACCELERATOR LAB,BATAVIA,IL 60510. NR 29 TC 17 Z9 17 U1 0 U2 0 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0168-9002 J9 NUCL INSTRUM METH A JI Nucl. Instrum. Methods Phys. Res. Sect. A-Accel. Spectrom. Dect. Assoc. Equip. PD SEP 1 PY 1994 VL 348 IS 2-3 BP 269 EP 274 DI 10.1016/0168-9002(94)90745-5 PG 6 WC Instruments & Instrumentation; Nuclear Science & Technology; Physics, Nuclear; Physics, Particles & Fields SC Instruments & Instrumentation; Nuclear Science & Technology; Physics GA PF645 UT WOS:A1994PF64500015 ER PT J AU ANDERSON, DF KWAN, S PESKOV, V AF ANDERSON, DF KWAN, S PESKOV, V TI HIGH COUNTING RATE RESISTIVE-PLATE CHAMBER SO NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH SECTION A-ACCELERATORS SPECTROMETERS DETECTORS AND ASSOCIATED EQUIPMENT LA English DT Article; Proceedings Paper CT 3rd London Conference on Position Sensitive Detectors CY SEP 06-10, 1993 CL BRUNEL UNIV, LONDON, ENGLAND HO BRUNEL UNIV ID GLASS AB Resistive-glass, parallel-plate chambers are studied in both spark and avalanche modes. In the avalanche mode rates of over 10(3) s-1 cm-2 are achievable with a total collected charge per pulse of 10(8) electrons. Operated at low pressure and with secondary-electron emission from a porous CsI surface, a timing resolution of 600 ps has been measured. Future improvements are discussed. RP ANDERSON, DF (reprint author), FERMILAB NATL ACCELERATOR LAB,PARTICLE DETECTOR GRP,BATAVIA,IL 60510, USA. NR 18 TC 12 Z9 12 U1 0 U2 0 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0168-9002 J9 NUCL INSTRUM METH A JI Nucl. Instrum. Methods Phys. Res. Sect. A-Accel. Spectrom. Dect. Assoc. Equip. PD SEP 1 PY 1994 VL 348 IS 2-3 BP 324 EP 328 DI 10.1016/0168-9002(94)90755-2 PG 5 WC Instruments & Instrumentation; Nuclear Science & Technology; Physics, Nuclear; Physics, Particles & Fields SC Instruments & Instrumentation; Nuclear Science & Technology; Physics GA PF645 UT WOS:A1994PF64500025 ER PT J AU ADRIANI, O ALCARAZ, J AHLEN, S AMBROSI, G BASCHIROTTO, A BATTISTON, R BAY, A BENCZE, G BERTUCCI, B BIASINI, M BILEI, GM BOBBINK, GJ BOSETTI, M BROOKS, ML BUSENITZ, J BURGER, WJ CAMPS, C CARIA, M CASTELLINI, G CHEN, A COAN, TE COMMICHAU, V DIBITONTO, D DUINKER, P EASO, S EXTERMANN, P FIANDRINI, E GOUGAS, A HANGARTER, K HAUVILLER, C HERVE, A HOU, S JOSA, I KAPUSTINSKI, JS KIM, D KINNISON, WW KORNIS, J KRASTEV, VR LANDI, G LEBEAU, M LECOMTE, P LEE, DM LEISTE, R LIN, WT LOHMANN, W MASSETTI, R MILLS, GB NOWAK, H PASSALEVA, G PAUL, T PAULUZZI, M PENSOTTI, S RANCOITA, PG RATTAGGI, M ROSCH, A SANTOCCHIA, A SACHITZ, M SCHMITZ, P SCHONEICH, B SERVOLI, L SUSINNO, G TERZI, G TOTH, J VIERTEL, GM VOGT, H WALDMEIER, S WEGMANN, J WEILL, R XU, J YEH, SC ZHOU, B AF ADRIANI, O ALCARAZ, J AHLEN, S AMBROSI, G BASCHIROTTO, A BATTISTON, R BAY, A BENCZE, G BERTUCCI, B BIASINI, M BILEI, GM BOBBINK, GJ BOSETTI, M BROOKS, ML BUSENITZ, J BURGER, WJ CAMPS, C CARIA, M CASTELLINI, G CHEN, A COAN, TE COMMICHAU, V DIBITONTO, D DUINKER, P EASO, S EXTERMANN, P FIANDRINI, E GOUGAS, A HANGARTER, K HAUVILLER, C HERVE, A HOU, S JOSA, I KAPUSTINSKI, JS KIM, D KINNISON, WW KORNIS, J KRASTEV, VR LANDI, G LEBEAU, M LECOMTE, P LEE, DM LEISTE, R LIN, WT LOHMANN, W MASSETTI, R MILLS, GB NOWAK, H PASSALEVA, G PAUL, T PAULUZZI, M PENSOTTI, S RANCOITA, PG RATTAGGI, M ROSCH, A SANTOCCHIA, A SACHITZ, M SCHMITZ, P SCHONEICH, B SERVOLI, L SUSINNO, G TERZI, G TOTH, J VIERTEL, GM VOGT, H WALDMEIER, S WEGMANN, J WEILL, R XU, J YEH, SC ZHOU, B TI THE NEW DOUBLE-SIDED SILICON MICROVERTEX DETECTOR FOR THE L3 EXPERIMENT SO NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH SECTION A-ACCELERATORS SPECTROMETERS DETECTORS AND ASSOCIATED EQUIPMENT LA English DT Article AB The new technologies used in the construction of the L3 Silicon Microvertex Detector (SMD) at LEP are presented. The SMD consists of two cylindrical layers of double sided silicon sensors to provide very precise measurements of both r(phi) and z coordinates. In order to minimize the amount of material in the central region, a Kapton fanout has been developed to bring the signals of the z strips (transverse coordinate) to the end of the mechanical structure. To get rid of the leakage currents a new capacitor chip, with diode protection against overvoltages, has been designed and used. In addition, a solution based on optodecoupling has been adopted to read the silicon n-side strips operating at the bias voltage. C1 UNIV ALABAMA, TUSCALOOSA, AL 35401 USA. RMKI, BUDAPEST, HUNGARY. INFN, FLORENCE, ITALY. IROE, FLORENCE, ITALY. LANL, LOS ALAMOS, NM USA. LAPP, ANNECY, FRANCE. NIKHEE, AMSTERDAM, NETHERLANDS. NCU, CHUNGLI, TAIWAN. DESY, ZEUTHEN, GERMANY. NATL TSING HUA UNIV, HSINCHU 300, TAIWAN. SWISS FED INST TECHNOL, CH-8006 ZURICH, SWITZERLAND. UNIV LAUSANNE, CH-1000 LAUSANNE 17, SWITZERLAND. UNIV MILAN, INFN, I-20122 MILAN, ITALY. UNIV PERUGIA, INFN, I-06100 PERUGIA, ITALY. BOSTON UNIV, BOSTON, MA 02215 USA. TECH UNIV BUDAPEST, INST PHYS, H-1521 BUDAPEST, HUNGARY. CERN, CH-1211 GENEVA 23, SWITZERLAND. UNIV GENEVA, CH-1211 GENEVA 4, SWITZERLAND. JOHNS HOPKINS UNIV, BALTIMORE, MD 21218 USA. RHEIN WESTFAL TH AACHEN, INST PHYS 3, W-5100 AACHEN, GERMANY. RI Fiandrini, Emanuele/C-4549-2008; Rosch, Achim/A-2962-2009; Servoli, Leonello/E-6766-2012; bertucci, bruna/J-5237-2012; Josa, Isabel/K-5184-2014; Rancoita, Pier Giorgio/J-9896-2015; OI Rosch, Achim/0000-0002-6586-5721; Servoli, Leonello/0000-0003-1725-9185; Rancoita, Pier Giorgio/0000-0002-1990-4283; Ambrosi, Giovanni/0000-0001-6977-9559; Castellini, Guido/0000-0002-0177-0643; Bertucci, Bruna/0000-0001-7584-293X NR 12 TC 3 Z9 3 U1 0 U2 3 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0168-9002 EI 1872-9576 J9 NUCL INSTRUM METH A JI Nucl. Instrum. Methods Phys. Res. Sect. A-Accel. Spectrom. Dect. Assoc. Equip. PD SEP 1 PY 1994 VL 348 IS 2-3 BP 431 EP 435 DI 10.1016/0168-9002(94)90774-9 PG 5 WC Instruments & Instrumentation; Nuclear Science & Technology; Physics, Nuclear; Physics, Particles & Fields SC Instruments & Instrumentation; Nuclear Science & Technology; Physics GA PF645 UT WOS:A1994PF64500044 ER PT J AU YOO, SS WANG, KM MONTANO, PA FAURIE, JP HUANG, Q RODRICKS, B AF YOO, SS WANG, KM MONTANO, PA FAURIE, JP HUANG, Q RODRICKS, B TI FAST PHOTOCONDUCTOR CDTE DETECTORS FOR SYNCHROTRON X-RAY STUDIES SO NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH SECTION A-ACCELERATORS SPECTROMETERS DETECTORS AND ASSOCIATED EQUIPMENT LA English DT Article; Proceedings Paper CT 3rd London Conference on Position Sensitive Detectors CY SEP 06-10, 1993 CL BRUNEL UNIV, LONDON, ENGLAND HO BRUNEL UNIV AB The Advanced Photon Source will be the brightest source of synchroton X-rays when it becomes operational in 1996. During normal operation, the ring will be filled with 20 bunches of positrons with an interbunch spacing of 184 ns and a bunch width of 72 ps. To perform experiments with X-rays generated by positions on these time scales, one needs extremely high speed detectors. To achieve the necessary high speed, we are developing MBE-grown CdTe-based photoconductive position sensitive array detectors. The arrays fabricated have 64 pixels with a gap of 100 mum between the pixels. The high speed response of the devices was tested using a short pulse laser. X-ray static measurements were performed using an X-ray tube and synchrotron radiation to study the device's response to flux and wavelength changes. In this paper, we shall present the response of the devices to some of these tests and also discuss different physics aspects that need to be considered when designing high speed detectors. C1 ARGONNE NATL LAB,ADV PHOTON SOURCE,ARGONNE,IL 60439. UNIV ILLINOIS,DEPT PHYS,CHICAGO,IL 60680. ARGONNE NATL LAB,DIV MAT SCI,ARGONNE,IL 60439. NR 10 TC 4 Z9 4 U1 0 U2 0 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0168-9002 J9 NUCL INSTRUM METH A JI Nucl. Instrum. Methods Phys. Res. Sect. A-Accel. Spectrom. Dect. Assoc. Equip. PD SEP 1 PY 1994 VL 348 IS 2-3 BP 527 EP 530 PG 4 WC Instruments & Instrumentation; Nuclear Science & Technology; Physics, Nuclear; Physics, Particles & Fields SC Instruments & Instrumentation; Nuclear Science & Technology; Physics GA PF645 UT WOS:A1994PF64500064 ER PT J AU RODRICKS, B HUANG, Q HOPF, R WANG, KM AF RODRICKS, B HUANG, Q HOPF, R WANG, KM TI A LARGE-AREA DETECTOR FOR X-RAY APPLICATIONS SO NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH SECTION A-ACCELERATORS SPECTROMETERS DETECTORS AND ASSOCIATED EQUIPMENT LA English DT Article; Proceedings Paper CT 3rd London Conference on Position Sensitive Detectors CY SEP 06-10, 1993 CL BRUNEL UNIV, LONDON, ENGLAND HO BRUNEL UNIV ID SYNCHROTRON RADIATION; DIFFRACTION AB A large area detector for X-ray synchrotron applications has been developed. The front end of this device consists of a scintillator coupled to a fiber-optic taper. The fiber-optic taper is comprised of 4 smaller (70 mm x 70 mm) tapers fused together in a square matrix giving an active area of 140 mm x 140 mm. Each taper has a demagnification of 5.5 resulting in four small ends that are 12 mm diagonally across. The small ends of each taper are coupled to four microchannel-plate-based image intensifiers. The output from each image intensifier is focused onto a Charge Coupled Device (CCD) detector. The four CCDs are read out in parallel and are independently controlled. The image intensifiers also act as fast (20 ns) electronic shutters. The system is capable of displaying images in real time. Additionally, with independent control on the readout of each row of data from the CCD, the system is capable of performing high speed imaging through novel readout manipulation. RP RODRICKS, B (reprint author), ARGONNE NATL LAB,ADV PHOTON SOURCE,9700 S CASS AVE,ARGONNE,IL 60439, USA. NR 10 TC 4 Z9 4 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 SEP 1 PY 1994 VL 348 IS 2-3 BP 572 EP 576 DI 10.1016/0168-9002(94)90803-6 PG 5 WC Instruments & Instrumentation; Nuclear Science & Technology; Physics, Nuclear; Physics, Particles & Fields SC Instruments & Instrumentation; Nuclear Science & Technology; Physics GA PF645 UT WOS:A1994PF64500073 ER PT J AU NADAY, I WESTBROOK, EM WESTBROOK, ML TRAVIS, DJ STANTON, M PHILLIPS, WC OMARA, D XIE, JH AF NADAY, I WESTBROOK, EM WESTBROOK, ML TRAVIS, DJ STANTON, M PHILLIPS, WC OMARA, D XIE, JH TI CHARACTERIZATION AND DATA-COLLECTION ON A DIRECT-COUPLED CCD X-RAY-DETECTOR SO NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH SECTION A-ACCELERATORS SPECTROMETERS DETECTORS AND ASSOCIATED EQUIPMENT LA English DT Article; Proceedings Paper CT 3rd London Conference on Position Sensitive Detectors CY SEP 06-10, 1993 CL BRUNEL UNIV, LONDON, ENGLAND HO BRUNEL UNIV ID QUANTUM EFFICIENCY; AREA DETECTOR; CRYSTALLOGRAPHY; SYNCHROTRON AB A large-area, multi-module, CCD-based detector without intensification stages is being developed by our group for X-ray diffraction applications. Each module consists of a fiberoptic taper with a phosphor deposited on the large end and a large-format, scientific CCD bonded to the small end. A single module has been constructed to evaluate the performance of this type of detector. This module has an active area of 43 x 43 mm2, a point response function FWHM = 80 mum, a dynamic range of > 20 000:1, and a high DQE. Using four parallel readout circuits, the CCD can be read out in 1.8 s. Crystallographic data collected using a rotating-anode source demonstrate the capability of this type of detector. C1 BRANDEIS UNIV,ROSENSTIEL BASIC MED SCI RES CTR,WALTHAM,MA 02254. ARGONNE NATL LAB,ARGONNE,IL 60439. NR 19 TC 24 Z9 24 U1 0 U2 0 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0168-9002 J9 NUCL INSTRUM METH A JI Nucl. Instrum. Methods Phys. Res. Sect. A-Accel. Spectrom. Dect. Assoc. Equip. PD SEP 1 PY 1994 VL 348 IS 2-3 BP 635 EP 640 DI 10.1016/0168-9002(94)90814-1 PG 6 WC Instruments & Instrumentation; Nuclear Science & Technology; Physics, Nuclear; Physics, Particles & Fields SC Instruments & Instrumentation; Nuclear Science & Technology; Physics GA PF645 UT WOS:A1994PF64500084 ER PT J AU HUANG, Q HOPF, R RODRICKS, B AF HUANG, Q HOPF, R RODRICKS, B TI A VXI-BASED HIGH-SPEED X-RAY CCD DETECTOR SO NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH SECTION A-ACCELERATORS SPECTROMETERS DETECTORS AND ASSOCIATED EQUIPMENT LA English DT Article; Proceedings Paper CT 3rd London Conference on Position Sensitive Detectors CY SEP 06-10, 1993 CL BRUNEL UNIV, LONDON, ENGLAND HO BRUNEL UNIV ID SYNCHROTRON RADIATION; DIFFRACTION; UNDULATOR AB For time-resolved X-ray scattering, one ideally wants a high speed detector that also is capable of giving position sensitive information. Charge Coupled Devices (CCDs) have been used successfully as X-ray detectors. Unfortunately, they are inherently slow because of the serial readout. EEV has developed a CCD that has eight channels of parallel readout, thus increasing the speed eightfold. Using state-of-the-art VXI electronics, we have developed a readout system that could read the entire array in 2.5 ms using a 20-MHz readout clock. For testing and characterization, the device was clocked at a significantly slower speed of 30 kHz. The data are preamplified, and all eight channels of output are simultaneously digitized to 12 bits and stored in buffer memory. The system is controlled by a 486-based PC through an MXI bus' and VXI controller using commerically available software. The system is also capable of real-time image display and manipulation. C1 ARGONNE NATL LAB,ADV PHOTON SOURCE,ARGONNE,IL 60439. NR 9 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 SEP 1 PY 1994 VL 348 IS 2-3 BP 645 EP 648 DI 10.1016/0168-9002(94)90816-8 PG 4 WC Instruments & Instrumentation; Nuclear Science & Technology; Physics, Nuclear; Physics, Particles & Fields SC Instruments & Instrumentation; Nuclear Science & Technology; Physics GA PF645 UT WOS:A1994PF64500086 ER PT J AU DURST, MJ VIOLET, CE WINTER, NW MEI, Z AF DURST, MJ VIOLET, CE WINTER, NW MEI, Z TI CURVE-FITTING COMPLEX MOSSBAUER-SPECTRA - APPLICATION TO HOBA2(CU0.95FE0.05)3O7.02 SO NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH SECTION B-BEAM INTERACTIONS WITH MATERIALS AND ATOMS LA English DT Article AB A method for determining the best fit of a complex Mossbauer spectrum is presented and applied to the room temperature Fe-57 Mossbauer spectrum of HoBa2(Cu0.95Fe0.05)3O7.02. The method generates many ''good fits'' as do previous methods. The ''best fit'', which is the goal of curve fitting, is selected from the class of good fits by means of a statistical test using the ''F'' function. The best fit for this compound represents 7 doublets. This is significantly larger than the previously reported number (3 or 4) of subspectra associated with REBa2(Cu1-xFe(x))3O(y) compounds. Assuming no mixed valence, this implies 7 Fe sites. This result is also significantly larger than the previously reported number of Fe sites (1-4) in the REBa2(Cu1-xFe(x))3O(y) compounds. For 6 of the 7 doublets, the isomer shift, quadrupole splitting and line width are strongly correlated. The valence state corresponding to these 6 doublets is high spin + 4. The seventh doublet is high spin + 3. The sum of Mossbauer site multiplicities is related to the number of accidental degeneracies by a sum rule. C1 LAWRENCE LIVERMORE NATL LAB,LIVERMORE,CA 94550. LAWRENCE BERKELEY LAB,BERKELEY,CA 94720. HEWLETT PACKARD CORP,PALO ALTO,CA 94304. NR 12 TC 0 Z9 0 U1 0 U2 0 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0168-583X J9 NUCL INSTRUM METH B JI Nucl. Instrum. Methods Phys. Res. Sect. B-Beam Interact. Mater. Atoms PD SEP PY 1994 VL 93 IS 4 BP 521 EP 529 DI 10.1016/0168-583X(94)95643-X PG 9 WC Instruments & Instrumentation; Nuclear Science & Technology; Physics, Atomic, Molecular & Chemical; Physics, Nuclear SC Instruments & Instrumentation; Nuclear Science & Technology; Physics GA PG239 UT WOS:A1994PG23900020 ER EF