FN Thomson Reuters Web of Science™ VR 1.0 PT J AU ANTONIO, MR SODERHOLM, L AF ANTONIO, MR SODERHOLM, L TI CERIUM VALENCE IN CERIUM-EXCHANGED PREYSSLERS HETEROPOLYANION THROUGH X-RAY-ABSORPTION NEAR-EDGE STRUCTURE SO INORGANIC CHEMISTRY LA English DT Article ID SPECTROSCOPY; LANTHANIDE; COMPLEXES; XANES; CATIONS; STATE; ENVIRONMENTS; DIMENSIONS; CHEMISTRY; CATALYSTS AB The sodium ion in the heteropolytungstate known as the Preyssler anion, [NaP5W30O110](14-), was exchanged with cerium from aqueous solutions of ammonium eerie nitrate, [NH4]Ce-2(IV)(NO3)(6), as described by Creaser et al. [Inorg. Chem. 1993, 32, 1573]. The valence of cerium in this heteropolyanion was determined through Ce L-edge XANES, X-ray absorption near-edge structure. The XANES results demonstrate that cerium is trivalent in the Ce-exchanged Preyssler heteropolyanion in the solid state and in aqueous solution (1 M H2SO4) at rest potential and after constant-potential, bulk electrolysis at -0.55 V vs SCE. The encapsulated sodium ion of the Preyssler anion was shown to be directly exchangeable with Ce-III by prolonged (48 h), high temperature (165 degrees C) aqueous treatments with either Ce(NO3)(3).6H(2)O or CeCl3.7H(2)O in Teflon-lined pressure vessels. RP ANTONIO, MR (reprint author), ARGONNE NATL LAB,DIV CHEM,ARGONNE,IL 60439, USA. OI Antonio, Mark/0000-0002-1208-4534 NR 56 TC 47 Z9 47 U1 1 U2 8 PU AMER CHEMICAL SOC PI WASHINGTON PA PO BOX 57136, WASHINGTON, DC 20037-0136 SN 0020-1669 J9 INORG CHEM JI Inorg. Chem. PD DEC 21 PY 1994 VL 33 IS 26 BP 5988 EP 5993 DI 10.1021/ic00104a004 PG 6 WC Chemistry, Inorganic & Nuclear SC Chemistry GA PZ161 UT WOS:A1994PZ16100004 ER PT J AU MIURA, M MAJUMDER, SA HOBBS, JD RENNER, MW FURENLID, LR SHELNUTT, JA AF MIURA, M MAJUMDER, SA HOBBS, JD RENNER, MW FURENLID, LR SHELNUTT, JA TI SYNTHESIS AND SPECTROSCOPIC CHARACTERIZATION OF OCTAACETIC ACID TETRAPHENYLPORPHYRINS SO INORGANIC CHEMISTRY LA English DT Article ID RAMAN DIFFERENCE SPECTROSCOPY; NONPLANAR NICKEL(II) PORPHYRINS; PI-PI-COMPLEX; RESONANCE RAMAN; ELECTRONIC-STRUCTURE; ISOTOPE SHIFTS; FORCE-FIELD; UROPORPHYRIN; DERIVATIVES; HEMOGLOBIN AB Members of a new class of water-soluble, nonplanar porphyrins based on 5,10,15,20-tetraphenylporpyrin-2,3,7,8,12,13,17,18 -octaacetic acid (OAATPPs) have been synthesized, and their physical and chemical properties as well as their interactions with complexing agents have been investigated using UV-visible absorption, EXAFS, nuclear magnetic resonance and resonance Raman spectroscopies. Red shifts of 19-36 nm in the major absorption bands are noted for Ni derivatives of OAATPP and its octamethyl ester (OME), meso-tetrakis(p-nitrophenyl)-porphyrinoctaacetic acid octamethyl ester, and octakis(hydroxyethyl)tetraphenylporphyrin relative to nickel tetraphenylporphyrin. These red shifts are indicative of a high degree of nonplanarity. The short Ni-N distances of 1.92(2) Angstrom for NiOAATPP-OME and 1.89(2) Angstrom for NiOAATNPP-OME from EXAFS experiments corroborate the nonplanar nature of these porphyrins. The decreased ring current effect and temperature-dependent NMR measurements also confirm that the porphyrins are nonplanar in solution. Resonance Raman studies also indicate nonplanar conformations for NiOAATPP and its derivatives by the characteristic downshifts in the frequencies of the structure-sensitive marker lines. At low pH (< 3) or in 4.5 M NaCl, conditions under which planar octaacid porphyrins like nickel uroporphyrin form pi-pi aggregates that give small characteristic upshifts in the structure-sensitive Raman lines, NiOAATPP shows no significant changes in either the absorption or the Raman spectra. The pi-pi aggregates formed by planar Ni uroporphyrin do not form for NiOAATPP most likely because of the steric difficulty in stacking the highly nonplanar and sterically hindered OAATPPs. Finally, the affinity for axially coordinated nitrogenous bases is decreased by nonplanarity and increased by electron-withdrawing peripheral substituents. C1 BROOKHAVEN NATL LAB,DEPT APPL SCI,UPTON,NY 11973. BROOKHAVEN NATL LAB,NATL SYNCHROTRON LIGHT SOURCE DEPT,UPTON,NY 11973. SANDIA NATL LABS,DEPT FUEL SCI,ALBUQUERQUE,NM 87185. UNIV NEW MEXICO,DEPT CHEM,ALBUQUERQUE,NM 87131. RP MIURA, M (reprint author), BROOKHAVEN NATL LAB,DEPT MED,UPTON,NY 11973, USA. RI Shelnutt, John/A-9987-2009 OI Shelnutt, John/0000-0001-7368-582X NR 57 TC 18 Z9 18 U1 1 U2 8 PU AMER CHEMICAL SOC PI WASHINGTON PA PO BOX 57136, WASHINGTON, DC 20037-0136 SN 0020-1669 J9 INORG CHEM JI Inorg. Chem. PD DEC 21 PY 1994 VL 33 IS 26 BP 6078 EP 6085 DI 10.1021/ic00104a016 PG 8 WC Chemistry, Inorganic & Nuclear SC Chemistry GA PZ161 UT WOS:A1994PZ16100016 ER PT J AU HOWLETT, AR PETERSEN, OW STEEG, PS BISSELL, MJ AF HOWLETT, AR PETERSEN, OW STEEG, PS BISSELL, MJ TI A NOVEL FUNCTION FOR THE NM23-H1 GENE - OVEREXPRESSION IN HUMAN BREAST-CARCINOMA CELLS LEADS TO THE FORMATION OF BASEMENT-MEMBRANE AND GROWTH ARREST SO JOURNAL OF THE NATIONAL CANCER INSTITUTE LA English DT Article ID NUCLEOSIDE DIPHOSPHATE KINASE; PROTEIN EXPRESSION; GOOD PROGNOSIS; DIFFERENTIATION; CANCER; TRANSFECTION; ASSOCIATION; METASTASIS AB Background: We have developed a culture system using reconstituted basement membrane components in which normal human mammary epithelial cells exhibit several aspects of the development and differentiation process, including formation of acinar-like structures, production and basal deposition of basement membrane components, and production and apical secretion of sialomucins. Cell lines and cultures from human breast carcinomas failed to recapitulate this process. The data indicate the importance of cellular interactions with the basement membrane in the regulation of normal breast differentiation and, potentially, its loss in neoplasia. Purpose: Our purpose was to use this assay to investigate the role of the putative metastasis suppresser gene nm23-H1 in mammary development and differentiation. Methods: The metastatic human breast carcinoma cell line MDA-MB-435, clones transfected with a control pCMVBamneo vector, and clones transfected with pCMVBamneo vector containing nm23-H1 complementary DNA (the latter of which exhibited a substantial reduction in spontaneous metastatic potential in vivo) were cultured within a reconstituted basement membrane. Clones were examined for formation of acinus-like spheres, deposition of basement membrane components, production of sialomucin, polarization, and growth arrest. Results: In contrast to the parental cell line and control transfectants, MDA-MB-435 breast carcinoma cells overexpressing Nm23-H1 protein regained several aspects of the normal phenotype within reconstituted basement membrane. Nm23-H1 protein-positive cells formed organized acinus-like spheres, deposited the basement membrane components type IV collagen and, to some extent, laminin to the outside of the spheres, expressed sialomucin, and growth arrested. Growth arrest of Nm23-H1 protein-positive cells was preceded by and correlated with formation of a basement membrane, suggesting a causal relationship. Conclusion: The data indicate a previously unidentified cause-and-effect relationship between nm23-H1 gene expression and morphological-biosynthetic-growth aspects of breast differentiation in this model system. Implications: While the basement membrane microenvironment is capable of directing the differentiation of normal human breast cells, neoplastic transformation abrogates this relationship, suggesting that intrinsic cellular events are also critical to this process. The data identify nm23-H1 gene expression as one of these events, suggesting an important role in the modulation of cellular responsiveness to the microenvironment. The data also identify previously unknown growth inhibitory effects of nm23-H1 gene overexpression. C1 UNIV COPENHAGEN,PANUM INST,DEPT MED ANAT A,COPENHAGEN N,DENMARK. DANISH CANC SOC,DIV CANC BIOL,DEPT TUMOR ENDOCRINOL,COPENHAGEN O,DENMARK. NCI,DIV CANC BIOL DIAG & CTR,PATHOL LAB,WOMENS CANC SECT,BETHESDA,MD 20892. RP HOWLETT, AR (reprint author), UNIV CALIF BERKELEY,LAWRENCE BERKELEY LAB,DIV LIFE SCI,BERKELEY,CA 94720, USA. FU NCI NIH HHS [U54 CA126552, R01 CA057621, R01 CA057621-07, R01 CA064786, R01 CA064786-04A1, U01 CA143233, U01 CA143233-01, U54 CA112970, U54 CA112970-01, U54 CA126552-01, U54 CA143836, U54 CA143836-01] NR 19 TC 124 Z9 129 U1 0 U2 4 PU NATL CANCER INSTITUTE PI BETHESDA PA 9030 OLD GEORGETOWN RD, BETHESDA, MD 20814 SN 0027-8874 J9 J NATL CANCER I JI J. Natl. Cancer Inst. PD DEC 21 PY 1994 VL 86 IS 24 BP 1838 EP 1844 DI 10.1093/jnci/86.24.1838 PG 7 WC Oncology SC Oncology GA PX380 UT WOS:A1994PX38000009 PM 7990158 ER PT J AU SAPPEY, AD AF SAPPEY, AD TI OPTICAL IMAGING THROUGH TURBID MEDIA WITH A DEGENERATE 4-WAVE-MIXING CORRELATION TIME GATE SO APPLIED OPTICS LA English DT Article ID PHASE-CONJUGATE REFLECTION; HIGHLY SCATTERING MEDIUM; KRF LASER-RADIATION; ELECTRONIC HOLOGRAPHY; OBJECTS HIDDEN; PULSE; TRANSILLUMINATION; TOMOGRAPHY; COHERENT; FLIGHT AB A novel method for detection of ballistic light and rejection of unwanted diffusive light to image structures inside highly scattering media is demonstrated. Degenerate four wave mixing (DFWM) of a doubled YAG laser in Rhodamine 6G is used to provide an ultrafast correlation time gate to discriminate against light that has undergone multiple scattering and therefore lost memory of the structures inside the scattering medium. We present preliminary results that determine the nature of the DFWM grating, confirm the coherence time of the laser, prove the phase-conjugate nature of the signal beam, and determine the dependence of the signal (reflectivity) on dye concentration and laser intensity. Finally, we have obtained images of a test cross-hair pattern through highly turbid suspensions of whole milk in water that through turbid media. Based on our results, the use of DFWM as an ultrafast time gate for the detection of ballistic light in optical mammography appears to hold great promise for improving the current state of the art. are opaque to the naked eye. These imaging experiments demonstrate the utility of DFWM for imaging through turbid media. Based on our results, the use of DFWM as an ultrafast time gate for the detection of ballistic light in optical mammography appears to hold great promise for improving the current state of the art. C1 LOS ALAMOS NATL LAB,LOS ALAMOS,NM 87545. NR 38 TC 16 Z9 16 U1 0 U2 3 PU OPTICAL SOC AMER PI WASHINGTON PA 2010 MASSACHUSETTS AVE NW, WASHINGTON, DC 20036 SN 0003-6935 J9 APPL OPTICS JI Appl. Optics PD DEC 20 PY 1994 VL 33 IS 36 BP 8346 EP 8354 PG 9 WC Optics SC Optics GA QC055 UT WOS:A1994QC05500008 PM 20963068 ER PT J AU BROMLEY, BC AF BROMLEY, BC TI CORRELATIONS IN COSMIC DENSITY FIELDS SO ASTROPHYSICAL JOURNAL LA English DT Article DE COSMOLOGY, THEORY; GALAXIES, CLUSTERING; LARGE-SCALE STRUCTURE OF UNIVERSE; METHODS, NUMERICAL ID LARGE-SCALE STRUCTURE; POINT CORRELATION-FUNCTIONS; COLD DARK MATTER; EXPANDING UNIVERSE; GALAXY; FLUCTUATIONS; STATISTICS; HIERARCHY; SIMULATIONS; EVOLUTION AB A method is proposed to place constraints on the functional form of the high-order correlation functions xi(n) that arise in cosmic density fields at large scales. This technique is based on a mass-in-cell statistic and a difference of mass in partitions of a cell. The relationship between these measures is sensitive to the formal structure of the xi(n) as well as their amplitudes. This relationship is quantified in several theoretical models of structure, based on the hierarchical clustering paradigm. The results lead to a test for specific types of hierarchical clustering that is sensitive to correlations of all orders. The method is applied to examples of simulated large-scale structure dominated by cold dark matter. In this preliminary study, the hierarchical paradigm appears to be a realistic approximation over a broad range of the scales. Furthermore, there is evidence that graphs of low-order vertices are dominant. On the basis of simulated data a phenomologicaI model is specified that gives a good representation of clustering from linear scales to the strongly clustered regime (xi(2) similar to 500). C1 DARTMOUTH COLL,DEPT PHYS & ASTRON,HANOVER,NH 03755. RP BROMLEY, BC (reprint author), LOS ALAMOS NATL LAB,POB 1663,MS B288,LOS ALAMOS,NM 87545, USA. NR 32 TC 6 Z9 6 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 DEC 20 PY 1994 VL 437 IS 2 BP 541 EP 549 DI 10.1086/175018 PN 1 PG 9 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA PX348 UT WOS:A1994PX34800001 ER PT J AU KINNISON, DE GRANT, KE CONNELL, PS ROTMAN, DA WUEBBLES, DJ AF KINNISON, DE GRANT, KE CONNELL, PS ROTMAN, DA WUEBBLES, DJ TI THE CHEMICAL AND RADIATIVE EFFECTS OF THE MOUNT-PINATUBO ERUPTION SO JOURNAL OF GEOPHYSICAL RESEARCH-ATMOSPHERES LA English DT Article ID SULFURIC-ACID; MT-PINATUBO; STRATOSPHERIC OZONE; EL-CHICHON; HETEROGENEOUS CHEMISTRY; TROPICAL OZONE; SIZE DISTRIBUTION; VOLCANIC AEROSOL; SULFATE AEROSOLS; GLOBAL OZONE AB The eruption of Mount Pinatubo introduced large amounts of sulfur-containing particles into the stratosphere. Stratospheric ozone measured by ozonesondes and satellites is significantly lower following the June 1991 eruption and throughout 1992 and 1993. To clarify the mechanisms leading to effects on stratospheric ozone, time-dependent stratospheric aerosol and gas experiment II (SAGE II) and cryogenic limb array elaton spectrometer (CLAES) aerosol optical extinction data and SAGE II surface area density are used as parameters in a two-dimensional (2-D) zonally averaged chemical radiative transport model. The model was integrated with time from before the eruption through December 1993. The modeled impact on global ozone results from increased rates of heterogeneous reactions on sulfate aerosols and from the increased radiative heating and scattering caused by these aerosols. The model's dynamical response to changes in forcing (from changes in radiatively active trace gas concentrations and from aerosol-heating) is treated in one of three ways: (1) the stratospheric temperature is perturbed, with fixed seasonal circulation, (2) the circulation is perturbed, with fixed seasonal temperature, or (3) both circulation and temperature are unperturbed, when investigating only the impact of Mount Pinatubo increased aerosol surface area density (SAD) and aerosol scattering bf actinic solar radiation. When the aerosol heating is allowed to modify the temperature distribution, the maximum change calculated in equatorial column ozone is -1.6%. The calculated equatorial temperature change and peak local ozone change in October 1991 are +6 K and -4%, respectively. When aerosol heating perturbs the circulation in the model, the maximum change in equatorial column ozone is -6%. Increased heterogeneous processing on sulfate aerosols is calculated to have changed equatorial column ozone in late 1991 by -1.5%. Global column ozone in the model in 1992 and 1993 changed by -2.8% and -2.4%, respectively. The relationship of ozone-controlling processes in the lower stratosphere is altered as well; HOx becomes the most important catalytic cycle, followed by ClOx and NOx. This is driven by significant changes in trace gas concentrations. In October 1991, lower stratospheric, equatorial NOx decreased by 40%, ClOx increased by 60%, and HOx increased by 25%. When the effect of heterogeneous chemical processing on sulfate aerosols is combined with aerosol heating, modifying either circulation or temperature, dramatically different ozone fingerprints with time and latitude are predicted. Model-derived changes in the equatorial region in column ozone best represented the observed data when perturbed circulation was combined with heterogeneous chemical effects. However, at high latitudes, the increased ozone production from the strengthening of the mean circulation tends to cancel the heterogeneous reduction of ozone. This is not in good agreement with observed data, especially in 1992 and 1993. When the circulation is held fixed and the temperature allowed to change, and heterogeneous chemical effects are included, the equatorial ozone decrease predicted was too small for 1991. However, the mid- to high-latitude decrease in 1992 and 1993 is in better agreement with observed data. RP KINNISON, DE (reprint author), LAWRENCE LIVERMORE NATL LAB, L-262, POB 808, LIVERMORE, CA 94551 USA. NR 76 TC 88 Z9 89 U1 0 U2 9 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 DEC 20 PY 1994 VL 99 IS D12 BP 25705 EP 25731 DI 10.1029/94JD02318 PG 27 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA PY229 UT WOS:A1994PY22900031 ER PT J AU ROSKELLEY, CD DESPREZ, PY BISSELL, MJ AF ROSKELLEY, CD DESPREZ, PY BISSELL, MJ TI EXTRACELLULAR MATRIX-DEPENDENT TISSUE-SPECIFIC GENE-EXPRESSION IN MAMMARY EPITHELIAL-CELLS REQUIRES BOTH PHYSICAL AND BIOCHEMICAL SIGNAL-TRANSDUCTION SO PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF THE UNITED STATES OF AMERICA LA English DT Article ID RECONSTITUTED BASEMENT-MEMBRANE; TYROSINE PHOSPHORYLATION; CYTOSKELETAL INTERACTIONS; DIFFERENTIATION; PROTEIN; ADHESION; COMPONENTS; SECRETION; PROLACTIN; MORPHOGENESIS AB Extracellular matrix (ECM) profoundly influeuces the growth and differentiation of the mammary gland epithelium, both in culture and in vivo. Utilizing a clonal population of mouse mammary epithelial cells that absolutely requires an exogenous ECM for function, we developed a rapid assay to study signal transduction by ECM. Two components of the cellular response to a basement membrane overlay that result in the expression of the milk protein beta-casein were defined. The first component of this response involves a rounding and clustering of the cells that can be physically mimicked by plating the cells on a nonadhesive substratum. The second component is biochemical in nature, and it is associated with beta(1) integrin clustering and increased tyrosine phosphorylation. The second component is initiated in a morphology-independent manner, but the proper translation of this biochemical signal into a functional response requires cell rounding and cell clustering. Thus, physical and biochemical signal transduction events contribute to the ECM-dependent regulation of tissue-specific gene expression in mouse mammary epithelial cells. C1 UNIV CALIF BERKELEY,LAWRENCE BERKELEY LAB,DIV LIFE SCI,CELL BIOL LAB,BERKELEY,CA 94720. RI Roskelley, Calvin /F-4630-2011 NR 44 TC 346 Z9 349 U1 1 U2 16 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 DEC 20 PY 1994 VL 91 IS 26 BP 12378 EP 12382 DI 10.1073/pnas.91.26.12378 PG 5 WC Multidisciplinary Sciences SC Science & Technology - Other Topics GA PY294 UT WOS:A1994PY29400006 PM 7528920 ER PT J AU BRUSH, GS ANDERSON, CW KELLY, TJ AF BRUSH, GS ANDERSON, CW KELLY, TJ TI THE DNA-ACTIVATED PROTEIN-KINASE IS REQUIRED FOR THE PHOSPHORYLATION OF REPLICATION PROTEIN-A DURING SIMIAN-VIRUS-40 DNA-REPLICATION SO PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF THE UNITED STATES OF AMERICA LA English DT Article ID RNA POLYMERASE-II; LARGE T-ANTIGEN; INVITRO REPLICATION; A PHOSPHORYLATION; KU-AUTOANTIGEN; HUMAN-CELLS; MOUSE P53; PURIFICATION; INITIATION; TEMPLATE AB The 32-kDa subunit of replication protein A (RPA) is phosphorylated during the S phase of the cell cycle in vivo and during simian virus 40 DNA replication in vitro. To explore the functional significance of this modification, we purified a HeLa fell protein kinase that phosphorylates RPA in the presence of single-stranded DNA. By several criteria we identified the purified enzyme as a form of the DNA-activated protein kinase (DNA-PK), a previously described high molecular weight protein kinase that is capable of phosphorylating a number of nuclear DNA binding proteins. Phosphorylation of RPA by DNA-PR is stimulated by natural single-stranded DNAs but not by homopolymers lacking secondary structure. Studies with the simian virus 40 model system indicate that DNA-PK is required for DNA-replication-dependent RPA phosphorylation. Depletion of the kinase activity, however, has no effect on the extent of DNA replication in vitro. Our data support a model in which phosphorylation of RPA by DNA-Pk is activated by formation of replication intermediates containing single- and double-stranded regions. This event may be involved in a signaling mechanism that coordinates DNA replication with the cell cycle. C1 JOHNS HOPKINS UNIV,SCH MED,DEPT MOLEC BIOL & GENET,BALTIMORE,MD 21205. BROOKHAVEN NATL LAB,DEPT BIOL,UPTON,NY 11973. NR 32 TC 153 Z9 153 U1 0 U2 1 PU NATL ACAD SCIENCES PI WASHINGTON PA 2101 CONSTITUTION AVE NW, WASHINGTON, DC 20418 SN 0027-8424 J9 P NATL ACAD SCI USA JI Proc. Natl. Acad. Sci. U. S. A. PD DEC 20 PY 1994 VL 91 IS 26 BP 12520 EP 12524 DI 10.1073/pnas.91.26.12520 PG 5 WC Multidisciplinary Sciences SC Science & Technology - Other Topics GA PY294 UT WOS:A1994PY29400035 PM 7809070 ER PT J AU YUAN, HSH STEVENS, RC BAU, R MOSHER, HS KOETZLE, TF AF YUAN, HSH STEVENS, RC BAU, R MOSHER, HS KOETZLE, TF TI DETERMINATION OF THE ABSOLUTE-CONFIGURATION OF (+)-NEOPENTYL-1-D ALCOHOL BY NEUTRON AND X-RAY-DIFFRACTION ANALYSIS SO PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF THE UNITED STATES OF AMERICA LA English DT Article DE CHIRAL METHYLENE GROUP; DEUTERATED NEOPENTANOL; ALCOHOL DEHYDROGENASE ID TERNARY COMPLEX; DEHYDROGENASE; RESOLUTION; BINDING; CRYSTAL AB The absolute configuration of (+)-neopentyl-1-d alcohol, prepared by the reduction of 2,2-dimethylpropanal-1-d by actively fermenting yeast, has been determined to be S by neutron diffraction. The neutron study was carried out on the phthalate half ester of neopentyl-1-d alcohol, crystallized as its strychnine salt. The absolute configuration of the (-)-strychninium cation was first determined by an x-ray anomalous dispersion study of its iodide salt. The chiral skeleton of strychnine then served as a reference from which the absolute configuration of the -O-CHD-C(CH3)(3) group of neopentyl phthalate was determined. Difference Fourier maps calculated from the neutron data showed unambiguously that the -O-CHD-C(CH3)(3) groups of both independent molecules in the unit cell had the S configuration. This work proves conclusively that the yeast system reduces aldehydes by delivering hydrogen to the re face of the carbonyl group. Crystallographic details: (-)-strychninium (+)-neopentyl-1-d phthalate, space group P2(1) (monoclinic), a = 18.564(6) Angstrom, b = 7.713(2) Angstrom, c = 23.361(8) Angstrom, beta = 94.18(4)degrees, V = 3336.0(5) Angstrom(3), Z = 2 (T = 100 K). Final agreement factors are R(F) = 0.073 for 2768 reflections collected at room temperature (x-ray analysis) and R(F) = 0.144 for 960 reflections collected at 100 R (neutron analysis). C1 UNIV SO CALIF,DEPT CHEM,LOS ANGELES,CA 90089. STANFORD UNIV,DEPT CHEM,STANFORD,CA 94305. BROOKHAVEN NATL LAB,DEPT CHEM,UPTON,NY 11973. RI Stevens, Raymond/K-7272-2015 OI Stevens, Raymond/0000-0002-4522-8725 FU NIGMS NIH HHS [GM-29533] NR 49 TC 16 Z9 16 U1 0 U2 2 PU NATL ACAD SCIENCES PI WASHINGTON PA 2101 CONSTITUTION AVE NW, WASHINGTON, DC 20418 SN 0027-8424 J9 P NATL ACAD SCI USA JI Proc. Natl. Acad. Sci. U. S. A. PD DEC 20 PY 1994 VL 91 IS 26 BP 12872 EP 12876 DI 10.1073/pnas.91.26.12872 PG 5 WC Multidisciplinary Sciences SC Science & Technology - Other Topics GA PY294 UT WOS:A1994PY29400107 PM 7809138 ER PT J AU HALPERN, HJ YU, C PERIC, M BARTH, E GRDINA, DJ TEICHER, BA AF HALPERN, HJ YU, C PERIC, M BARTH, E GRDINA, DJ TEICHER, BA TI OXYMETRY DEEP IN TISSUES WITH LOW-FREQUENCY ELECTRON-PARAMAGNETIC-RESONANCE SO PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF THE UNITED STATES OF AMERICA LA English DT Article ID HYPERFINE COUPLING-CONSTANTS; NMR CONTRAST AGENTS; OXYGEN DISTRIBUTION; SPIN-RESONANCE; TENSION MEASUREMENTS; RECONSTRUCTION; LABEL; SENSITIVITY; DEPENDENCE; OXIMETRY AB We have measured the oxygen concentration in the body water of murine FSa and NFSa fibrosarcomas using a new method for quantitative oxygen concentration determination deep in the tissues of a living animal. The measurement uses unusually low-frequency electron paramagnetic spectroscopy sensitive to substrate 7 cm deep in tissue, partially deuterated spin probes (spin labels of molecular mass 195, approximating that of glucose) whose distribution compartment can be targeted with facile adduct substitution, and novel analytic techniques. We show that the water-compartment oxygen concentration of the tumors decreases as the tumor size increases and also shows a trend to decrease as radiobiologic hypoxia increases. An oxymetric spectral image of the tumor is presented. The technique will improve with larger human tissue samples. It provides the potential to quantitatively assess tissue hypoxia in ischemic or preischemic states in stroke and myocardial infarction. It will allow direct assessment of tumor hypoxia to determine the usefulness of radiation and chemotherapy adjuvants directed to hypoxic cell compartments. C1 UNIV CHICAGO,DEPT RADIAT & CELLULAR ONCOL,CHICAGO,IL 60637. ARGONNE NATL LAB,DIV BIOL & MED SCI,ARGONNE,IL 60439. HARVARD UNIV,SCH MED,DANA FARBER CANC INST,BOSTON,MA 02115. RP HALPERN, HJ (reprint author), UNIV CHICAGO,CTR RADIAT THERAPY,CHICAGO,IL 60637, USA. FU NCI NIH HHS [CA50679] NR 33 TC 133 Z9 135 U1 0 U2 8 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 DEC 20 PY 1994 VL 91 IS 26 BP 13047 EP 13051 DI 10.1073/pnas.91.26.13047 PG 5 WC Multidisciplinary Sciences SC Science & Technology - Other Topics GA PY294 UT WOS:A1994PY29400143 PM 7809170 ER PT J AU BOUCHARD, AM OSBOURN, GC SWARTZENTRUBER, BS AF BOUCHARD, AM OSBOURN, GC SWARTZENTRUBER, BS TI NEW METHOD FOR EMPIRICALLY DETERMINING SURFACE ELECTRONIC SPECIES FROM MULTIPLE-BIAS STM IMAGES - A MULTIVARIATE CLASSIFICATION APPROACH SO SURFACE SCIENCE LA English DT Article ID SCANNING-TUNNELING-MICROSCOPY; GE(111)-C(2X8); DEFECTS AB We introduce the use of multivariate image classification techniques to distinguish and identify surface electronic species directly from multiple-bias scanning tunneling microscope (STM) images. Multiple measurements at each site are used to distinguish and categorize inequivalent electronic or atomic species on the surface via a computerized classification algorithm. Then, comparison with theory or other suitably chosen experimental data enables the identification of each class. We demonstrate the technique by analyzing dual-polarity constant-current topographs of the Ge(111) surface. Without assuming a particular atomic structure of the surface, we find that just two measurements, negative- and positive-bias topography height, permit pixels to be separated into seven different classes. To assess the validity of our classifications and determine the identity of each class, we compare our results with the accepted atomic structure of the c(2X8) reconstruction of Ge(111). Labeling four of the classes as adatoms, first-layer atoms, and two inequivalent rest-atom sites, we find very good agreement with the c(2X8) structure. The remaining classes are associated with structural defects and contaminants. This work represents a first step toward developing a general electronic/chemical classification and identification tool for multivariate scanning probe microscopy imagery. RP BOUCHARD, AM (reprint author), SANDIA NATL LABS,POB 5800,MS 0350,ALBUQUERQUE,NM 87185, USA. NR 13 TC 6 Z9 6 U1 0 U2 0 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0039-6028 J9 SURF SCI JI Surf. Sci. PD DEC 20 PY 1994 VL 321 IS 3 BP 276 EP 286 DI 10.1016/0039-6028(94)90193-7 PG 11 WC Chemistry, Physical; Physics, Condensed Matter SC Chemistry; Physics GA QA552 UT WOS:A1994QA55200025 ER PT J AU YOSHIKAWA, SA NOGAMI, J QUATE, CF PIANETTA, P AF YOSHIKAWA, SA NOGAMI, J QUATE, CF PIANETTA, P TI BEHAVIOR OF TELLURIUM ON SILICON(100) SO SURFACE SCIENCE LA English DT Letter ID SI(100) SURFACE; EPITAXY; GERMANIUM; GROWTH; SB AB The adsorption of tellurium on Si(100) was investigated using scanning tunneling microscopy (STM) and LEED. Tellurium was evaporated onto the clean silicon (100)2 X 1 surface at approximate to 25 degrees C. Coverages ranging from 0.1 to 3.0 ML were investigated. Atom-resolved images reveal that low coverages of Te deposited at room temperature adsorb on top of the silicon 2 X 1 dimer rows with a minimum spacing of 2a where a = 3.84 Angstrom is the width of a 1 X 1 surface unit cell. There is a slight preference for growth along the silicon dimer rows. This surface saturates at 0.25 ML. When the low coverage sample is subsequently annealed for 10 min at 300 degrees C, trenches perpendicular to the silicon dimer rows appear with tellurium decorating the trench edge. At greater than or equal to 1 ML Te coverage, the surface consists of rows of Te with a spacing of a with missing rows of atoms at a maximum interval of 5-6 rows. C1 UNIV WISCONSIN,SURFACE STUDIES LAB,MILWAUKEE,WI 53201. UNIV WISCONSIN,DEPT PHYS,MILWAUKEE,WI 53201. STANFORD UNIV,GINZTON LAB,STANFORD,CA. RP YOSHIKAWA, SA (reprint author), STANFORD UNIV,STANFORD SYNCHROTRON RADIAT LAB,STANFORD,CA, USA. NR 18 TC 35 Z9 35 U1 2 U2 5 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0039-6028 J9 SURF SCI JI Surf. Sci. PD DEC 20 PY 1994 VL 321 IS 3 BP L183 EP L188 DI 10.1016/0039-6028(94)90172-4 PG 6 WC Chemistry, Physical; Physics, Condensed Matter SC Chemistry; Physics GA QA552 UT WOS:A1994QA55200004 ER PT J AU MAGRINI, KA BORON, D AF MAGRINI, KA BORON, D TI CARBON-DIOXIDE - GLOBAL PROBLEM AND GLOBAL RESOURCE SO CHEMISTRY & INDUSTRY LA English DT Article C1 US DOE,BIOL & CHEM TECHNOL RES PROGRAM,WASHINGTON,DC 20585. RP MAGRINI, KA (reprint author), NATL RENEWABLE ENERGY LAB,1617 COLE BLVD,GOLDEN,CO 80401, USA. NR 15 TC 7 Z9 7 U1 0 U2 1 PU SOC CHEMICAL INDUSTRY PI LONDON PA 14 BELGRAVE SQUARE, LONDON, ENGLAND SW1X 8PS SN 0009-3068 J9 CHEM IND-LONDON JI Chem. Ind. PD DEC 19 PY 1994 IS 24 BP 997 EP 1000 PG 4 WC Chemistry, Applied SC Chemistry GA PY469 UT WOS:A1994PY46900009 ER PT J AU BAGAN, E BALL, P BRAUN, VM GOSDZINSKY, P AF BAGAN, E BALL, P BRAUN, VM GOSDZINSKY, P TI CHARM QUARK MASS DEPENDENCE OF QCD CORRECTIONS TO NONLEPTONIC INCLUSIVE B-DECAYS SO NUCLEAR PHYSICS B LA English DT Article ID WEAK DECAYS; DIMENSIONAL REGULARIZATION; SUM-RULES; PARTICLES; BEAUTY; RATIO; MODEL AB We calculate the radiative corrections to the nonleptonic inclusive B decay mode b --> c(u) over bard$ taking into account the charm quark mass. Compared to the massless case, corrections resulting from a nonvanishing c quark mass increase the nonleptonic rate by (4-8)%, depending on the renormalization point. As a by-product of our calculation, we obtain an analytic expression for the radiative correction to the semileptonic decay b --> taking into account the tau lepton mass, and estimate the c quark mass effects on the nonleptonic decay mode b --> c(c) over bars$. C1 TECH UNIV MUNICH,DEPT PHYS T30,D-85747 GARCHING,GERMANY. MAX PLANCK INST PHYS & ASTROPHYS,D-80805 MUNICH,GERMANY. UNIV AUTONOMA BARCELONA,DEPT FIS,FIS TEOR GRP,E-08193 BARCELONA,SPAIN. UNIV AUTONOMA BARCELONA,INST FIS ALTES ENERGIES,E-08193 BARCELONA,SPAIN. RP BAGAN, E (reprint author), BROOKHAVEN NATL LAB,DEPT PHYS,UPTON,NY 11973, USA. NR 46 TC 69 Z9 69 U1 0 U2 1 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0550-3213 J9 NUCL PHYS B JI Nucl. Phys. B PD DEC 19 PY 1994 VL 432 IS 1-2 BP 3 EP 38 DI 10.1016/0550-3213(94)90591-6 PG 36 WC Physics, Particles & Fields SC Physics GA PX625 UT WOS:A1994PX62500001 ER PT J AU KNOX, L TURNER, MS AF KNOX, L TURNER, MS TI DETECTABILITY OF TENSOR PERTURBATIONS THROUGH ANISOTROPY OF THE COSMIC BACKGROUND-RADIATION SO PHYSICAL REVIEW LETTERS LA English DT Article ID GRAVITATIONAL-WAVES; INFLATIONARY UNIVERSE; GRAND UNIFICATION; COBE SATELLITE; IRAS GALAXIES; MICROWAVE; FLUCTUATIONS; COSMOLOGY; MODELS; SCENARIO C1 UNIV CHICAGO,DEPT PHYS,CHICAGO,IL 60637. UNIV CHICAGO,ENRICO FERMI INST,DEPT ASTRON & ASTROPHYS,CHICAGO,IL 60637. RP KNOX, L (reprint author), FERMILAB NATL ACCELERATOR LAB,NASA,FERMILAB ASTROPHYS CTR,BATAVIA,IL 60510, USA. NR 38 TC 53 Z9 53 U1 0 U2 1 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 0031-9007 J9 PHYS REV LETT JI Phys. Rev. Lett. PD DEC 19 PY 1994 VL 73 IS 25 BP 3347 EP 3350 DI 10.1103/PhysRevLett.73.3347 PG 4 WC Physics, Multidisciplinary SC Physics GA PX387 UT WOS:A1994PX38700005 ER PT J AU KOUWENHOVEN, LP JAUHAR, S ORENSTEIN, J MCEUEN, PL NAGAMUNE, Y MOTOHISA, I SAKAKI, H AF KOUWENHOVEN, LP JAUHAR, S ORENSTEIN, J MCEUEN, PL NAGAMUNE, Y MOTOHISA, I SAKAKI, H TI OBSERVATION OF PHOTON-ASSISTED TUNNELING THROUGH A QUANTUM-DOT SO PHYSICAL REVIEW LETTERS LA English DT Article ID POINT-CONTACT; TIME; ELECTRONS; TRANSPORT; PUMP C1 UNIV CALIF BERKELEY,DEPT PHYS,BERKELEY,CA 94720. UNIV CALIF BERKELEY,LAWRENCE BERKELEY LAB,DIV MAT SCI,BERKELEY,CA 94720. UNIV TOKYO,ADV SCI & TECHNOL RES CTR,MEGURO KU,TOKYO 153,JAPAN. RI Motohisa, Junichi/D-6174-2012; Orenstein, Joseph/I-3451-2015 NR 25 TC 278 Z9 283 U1 4 U2 15 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 DEC 19 PY 1994 VL 73 IS 25 BP 3443 EP 3446 DI 10.1103/PhysRevLett.73.3443 PG 4 WC Physics, Multidisciplinary SC Physics GA PX387 UT WOS:A1994PX38700029 ER PT J AU MARTIN, T BERMAN, G AF MARTIN, T BERMAN, G TI SWITCHING NANO-DEVICE BASED ON RABI OSCILLATIONS SO PHYSICS LETTERS A LA English DT Article AB We describe a switching device based on Rabi oscillations. The device consists of a well region separated from a free region by a potential barrier. The potential landscape is adjusted so that one bound state and one quasi level are present. By applying a microwave field with a driving frequency close to the separation between the two levels, a particle initially in the ground state can be activated to the quasi-level, and subsequently tunnel to the free region. The probability for tunneling in the free region exhibits a plateau structure, as the wave function is emitted by bursts after each Rabi oscillation. The leakage current can then be controlled by varying the amplitude of the external field, the barrier height/width, and the frequency mismatch. C1 LOS ALAMOS NATL LAB,CNLS,LOS ALAMOS,NM 87545. LOS ALAMOS NATL LAB,DIV THEORET,LOS ALAMOS,NM 87545. LV KIRENSKII INST PHYS,KRASNOYARSK 660036,RUSSIA. NR 5 TC 13 Z9 13 U1 0 U2 1 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0375-9601 J9 PHYS LETT A JI Phys. Lett. A PD DEC 19 PY 1994 VL 196 IS 1-2 BP 65 EP 69 DI 10.1016/0375-9601(94)91045-6 PG 5 WC Physics, Multidisciplinary SC Physics GA PX649 UT WOS:A1994PX64900013 ER PT J AU BUDA, SW AF BUDA, SW TI DIODE-LESS PEAK-HOLD CIRCUIT SO ELECTRONIC DESIGN LA English DT Note RP BUDA, SW (reprint author), BROOKHAVEN NATL LAB,UPTON,NY 11973, USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU PENTON PUBL INC PI CLEVELAND PA 1100 SUPERIOR AVE, CLEVELAND, OH 44114 SN 0013-4872 J9 ELECTRON DES JI Electron. Des. PD DEC 16 PY 1994 VL 42 IS 26 BP 115 EP 116 PG 2 WC Engineering, Electrical & Electronic SC Engineering GA PY013 UT WOS:A1994PY01300015 ER PT J AU NOZETTE, S RUSTAN, P PLEASANCE, LP HORAN, DM REGEON, P SHOEMAKER, EM SPUDIS, PD ACTON, CH BAKER, DN BLAMONT, JE BURATTI, BJ CORSON, MP DAVIES, ME DUXBURY, TC ELIASON, EM JAKOSKY, BM KORDAS, JF LEWIS, IT LICHTENBERG, CL LUCEY, PG MALARET, E MASSIE, MA RESNICK, JH ROLLINS, CJ PARK, HS MCEWEN, AS PRIEST, RE PIETERS, CM REISSE, RA ROBINSON, MS SIMPSON, RA SMITH, DE SORENSON, TC BREUGGE, RWV ZUBER, MT AF NOZETTE, S RUSTAN, P PLEASANCE, LP HORAN, DM REGEON, P SHOEMAKER, EM SPUDIS, PD ACTON, CH BAKER, DN BLAMONT, JE BURATTI, BJ CORSON, MP DAVIES, ME DUXBURY, TC ELIASON, EM JAKOSKY, BM KORDAS, JF LEWIS, IT LICHTENBERG, CL LUCEY, PG MALARET, E MASSIE, MA RESNICK, JH ROLLINS, CJ PARK, HS MCEWEN, AS PRIEST, RE PIETERS, CM REISSE, RA ROBINSON, MS SIMPSON, RA SMITH, DE SORENSON, TC BREUGGE, RWV ZUBER, MT TI THE CLEMENTINE MISSION TO THE MOON - SCIENTIFIC OVERVIEW SO SCIENCE LA English DT Article ID THERMAL EMISSION; COHERENT BACKSCATTER; SURFACE AB In the course of 71 days in lunar orbit, from 19 February to 3 May 1994, the Clementine spacecraft acquired just under two million digital images of the moon at visible and infrared wavelengths. These data are enabling the global mapping of the rock types of the lunar crust and the first detailed investigation of the geology of the lunar polar regions and the lunar far side. In addition, laser-ranging measurements provided the first view of the global topographic figure of the moon. The topography of many ancient impact basins has been measured, and a global map of the thickness of the lunar crust has been derived from the topography and gravity. C1 LAWRENCE LIVERMORE NATL LAB,LIVERMORE,CA 94550. USN,RES LAB,WASHINGTON,DC 20375. US GEOL SURVEY,FLAGSTAFF,AZ 86001. LUNAR & PLANETARY INST,HOUSTON,TX 77058. CALTECH,JET PROP LAB,PASADENA,CA 91109. UNIV COLORADO,LASP,BOULDER,CO 80309. CTR NATL ETUD SPATIALES,PARIS,FRANCE. RES SUPPORT INSTRUMENTS,ALEXANDRIA,VA 22314. RAND CORP,SANTA MONICA,CA 90407. UNIV HAWAII MANOA,HONOLULU,HI 96822. APPL COHERENT TECHNOL,HERNDON,VA 22070. PACIFIC ADV TECHNOL,SOLVANG,CA 94550. BROWN UNIV,PROVIDENCE,RI 02912. SCI INQUIRIES,CATONSVILLE,MD 21228. STANFORD UNIV,STANFORD,CA 94305. NASA,GODDARD SPACE FLIGHT CTR,GREENBELT,MD 20771. ALLIED SIGNAL AEROSP CO,ALEXANDRIA,VA 22314. SCI APPLICAT INT CORP,WASHINGTON,DC 20024. JOHNS HOPKINS UNIV,BALTIMORE,MD 21218. RP NOZETTE, S (reprint author), BALLIST MISSILE DEF ORG,WASHINGTON,DC, USA. NR 23 TC 253 Z9 263 U1 4 U2 14 PU AMER ASSOC ADVANCEMENT SCIENCE PI WASHINGTON PA 1200 NEW YORK AVE, NW, WASHINGTON, DC 20005 SN 0036-8075 J9 SCIENCE JI Science PD DEC 16 PY 1994 VL 266 IS 5192 BP 1835 EP 1839 DI 10.1126/science.266.5192.1835 PG 5 WC Multidisciplinary Sciences SC Science & Technology - Other Topics GA PX383 UT WOS:A1994PX38300028 PM 17737076 ER PT J AU GARCIA, JG ENAS, JD FRONCZEK, FR AF GARCIA, JG ENAS, JD FRONCZEK, FR TI 2,2-DIMETHYL-5-(DIMETHYLAMINO)INDAN-1,3-DIONE SO ACTA CRYSTALLOGRAPHICA SECTION C-CRYSTAL STRUCTURE COMMUNICATIONS LA English DT Article AB The title compound, C13H15NO2, lies on a crystallographic mirror plane. The indan-1,3-dione and the dimethylamino systems are therefore coplanar. The C-C-C angle formed by the gem-dimethyl groups is 110.3 (1)degrees and the C-C-C-O torsion angles which they form with the carbonyl O atoms have magnitudes of 61.6 (1) and 61.3 (1)degrees. The C=O distances are 1.217 (2) and 1.210 (2) Angstrom. The N-methyl groups lying on the crystallographic mirror plane have their atoms disordered into half-populated positions. The N-C(methyl) distances are 1.432 (2) and 1.447 (2) Angstrom. C1 LOUISIANA STATE UNIV,DEPT CHEM,BATON ROUGE,LA 70803. RP GARCIA, JG (reprint author), UNIV CALIF BERKELEY,LAWRENCE BERKELEY LAB,BERKELEY,CA 94720, USA. NR 17 TC 1 Z9 1 U1 0 U2 0 PU MUNKSGAARD INT PUBL LTD PI COPENHAGEN PA 35 NORRE SOGADE, PO BOX 2148, DK-1016 COPENHAGEN, DENMARK SN 0108-2701 J9 ACTA CRYSTALLOGR C JI Acta Crystallogr. Sect. C-Cryst. Struct. Commun. PD DEC 15 PY 1994 VL 50 BP 2025 EP 2027 DI 10.1107/S0108270194005238 PN 12 PG 3 WC Chemistry, Multidisciplinary; Crystallography SC Chemistry; Crystallography GA PX931 UT WOS:A1994PX93100081 ER PT J AU BARKIGIA, KM GOTTFRIED, DS AF BARKIGIA, KM GOTTFRIED, DS TI A NEW CRYSTAL FORM OF METHYL BACTERIOPHEOPHORBIDE-ALPHA SO ACTA CRYSTALLOGRAPHICA SECTION C-CRYSTAL STRUCTURE COMMUNICATIONS LA English DT Article ID PHOTOSYNTHETIC REACTION CENTER; RHODOPSEUDOMONAS-VIRIDIS; MOLECULAR-STRUCTURE; 3A RESOLUTION; PROTEIN; CHROMOPHORES; DIHYDRATE; MODELS; REDOX AB The structure of a new crystal form of methyl bacteriopheophorbide a, C36H40N4O6, which does not contain benzene molecules of crystallization, has been determined at 200 K. The molecule is slightly ruffled with maximum displacements from planarity of +/- 0.21 Angstrom in all five rings. The crystal packing is dominated by pi-pi interactions between pyrrole rings I and III of adjacent molecules, which are separated by 3.58 Angstrom. C1 STANFORD UNIV,DEPT CHEM,STANFORD,CA 94305. RP BARKIGIA, KM (reprint author), BROOKHAVEN NATL LAB,DEPT APPL SCI,UPTON,NY 11973, USA. NR 33 TC 12 Z9 13 U1 0 U2 0 PU MUNKSGAARD INT PUBL LTD PI COPENHAGEN PA 35 NORRE SOGADE, PO BOX 2148, DK-1016 COPENHAGEN, DENMARK SN 0108-2701 J9 ACTA CRYSTALLOGR C JI Acta Crystallogr. Sect. C-Cryst. Struct. Commun. PD DEC 15 PY 1994 VL 50 BP 2069 EP 2072 DI 10.1107/S0108270194004786 PN 12 PG 4 WC Chemistry, Multidisciplinary; Crystallography SC Chemistry; Crystallography GA PX931 UT WOS:A1994PX93100100 ER PT J AU CAMPBELL, JA STROMATT, RW SMITH, MR KOPPENAAL, DW BEAN, RM JONES, TE STRACHAN, DM BABAD, H AF CAMPBELL, JA STROMATT, RW SMITH, MR KOPPENAAL, DW BEAN, RM JONES, TE STRACHAN, DM BABAD, H TI ORGANIC-ANALYSIS AT THE HANFORD-NUCLEAR-SITE SO ANALYTICAL CHEMISTRY LA English DT Article ID COMPLEXING AGENTS C1 WESTINGHOUSE HANFORD CO, RICHLAND, WA 99352 USA. RP CAMPBELL, JA (reprint author), PACIFIC NW LAB, POB 999,MS P8-08, RICHLAND, WA 99352 USA. NR 27 TC 40 Z9 40 U1 0 U2 4 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 SN 0003-2700 J9 ANAL CHEM JI Anal. Chem. PD DEC 15 PY 1994 VL 66 IS 24 BP A1208 EP A1215 PG 8 WC Chemistry, Analytical SC Chemistry GA PW746 UT WOS:A1994PW74600001 ER PT J AU DOOLEY, TP PROBST, P MUNROE, PB MOLE, SE LIU, Z DOGGETT, NA AF DOOLEY, TP PROBST, P MUNROE, PB MOLE, SE LIU, Z DOGGETT, NA TI GENOMIC ORGANIZATION AND DNA-SEQUENCE OF THE HUMAN CATECHOLAMINE-SULFATING PHENOL SULFOTRANSFERASE GENE (STM) SO BIOCHEMICAL AND BIOPHYSICAL RESEARCH COMMUNICATIONS LA English DT Article ID FORM; CDNA AB The human monoamine neurotransmitter-preferring phenol sulfotransferase (M-PST) plays an essential role in the sulfation of catecholamines, such as dopamine. The cDNA encoding M-PST has been reported, and we have recently identified cosmid clones from human chromosome 16p11.2 for this gene, STM. Plasmid subclones derived from the STM cosmid clones were subjected to dideoxynucleotide chain termination sequencing to determine the genomic organization and DNA sequence of STM. The gene encoding full-length STM is approximately 6.4 kb and contains 8 exons and 7 introns. (C) 1994 Academic Press, Inc. C1 UCL, RAYNE INST, DEPT PAEDIAT, LONDON WC1E 6JJ, ENGLAND. LOS ALAMOS NATL LAB, DIV LIFE SCI, LOS ALAMOS, NM 87545 USA. LOS ALAMOS NATL LAB, CTR HUMAN GENOME STUDIES, LOS ALAMOS, NM 87545 USA. RP DOOLEY, TP (reprint author), SW FDN BIOMED RES, DEPT GENET, POB 28147, SAN ANTONIO, TX 78228 USA. OI Mole, Sara/0000-0003-4385-4957 FU NINDS NIH HHS [NS28722] NR 15 TC 28 Z9 29 U1 0 U2 1 PU ACADEMIC PRESS INC ELSEVIER SCIENCE PI SAN DIEGO PA 525 B ST, STE 1900, SAN DIEGO, CA 92101-4495 USA SN 0006-291X J9 BIOCHEM BIOPH RES CO JI Biochem. Biophys. Res. Commun. PD DEC 15 PY 1994 VL 205 IS 2 BP 1325 EP 1332 DI 10.1006/bbrc.1994.2810 PG 8 WC Biochemistry & Molecular Biology; Biophysics SC Biochemistry & Molecular Biology; Biophysics GA PY706 UT WOS:A1994PY70600049 PM 7802665 ER PT J AU PAPASPYROU, M FEINENDEGEN, LE MULLERGARTNER, HW AF PAPASPYROU, M FEINENDEGEN, LE MULLERGARTNER, HW TI PRELOADING WITH L-TYROSINE INCREASES THE UPTAKE OF BORONOPHENYLALANINE IN MOUSE MELANOMA-CELLS SO CANCER RESEARCH LA English DT Note ID NEUTRON-CAPTURE THERAPY; AMINO-ACIDS; TRANSPORT AB To improve the effectiveness of boron neutron capture therapy, the possibility of stimulating boron uptake was investigated in an experimental model. B16F1 mouse melanoma cells were exposed to boronophenylalanine (BPA). The intracellular boron concentration followed Michaelis-Menten kinetics in the early incubation phase, In the late phase, cellular boron concentration was linearly related to the BPA concentration in the culture medium. Incubation with L-tyrosine before exposure to BPA (preloading) increased the intracellular boron concentration by a factor of three. It is concluded that in B16F1 cells BPA is transported by L and presumably ASC (alanine, serine, and cysteine) transport systems, and that boron uptake can be effectively stimulated by L-tyrosine preloading. C1 FORSCHUNGSZENTRUM JULICH, RES CTR JULICH, INST MED, D-52425 JULICH, GERMANY. BROOKHAVEN NATL LAB, DEPT MED, UPTON, NY 11973 USA. NR 16 TC 19 Z9 19 U1 0 U2 0 PU AMER ASSOC CANCER RESEARCH PI PHILADELPHIA PA 615 CHESTNUT ST, 17TH FLOOR, PHILADELPHIA, PA 19106-4404 USA SN 0008-5472 EI 1538-7445 J9 CANCER RES JI Cancer Res. PD DEC 15 PY 1994 VL 54 IS 24 BP 6311 EP 6314 PG 4 WC Oncology SC Oncology GA PX306 UT WOS:A1994PX30600005 PM 7987818 ER PT J AU TANG, J AF TANG, J TI RESONANCE EFFECTS ON SUPEREXCHANGE AND SEQUENTIAL ELECTRON-TRANSFER REACTIONS DUE TO ENERGY-LEVEL CROSSING SO CHEMICAL PHYSICS LA English DT Article ID PHOTOSYNTHETIC REACTION CENTERS; PRIMARY CHARGE-SEPARATION; NONSUPEREXCHANGE COHERENT MECHANISM; BACTERIAL PHOTOSYNTHESIS; POLAR-SOLVENTS; DIELECTRIC FRICTION; 3-COMPONENT SYSTEM; SOLVATION DYNAMICS; TRANSFER KINETICS; CONDENSED PHASES AB A treatment using the Zusman equation is presented for electron-transfer reactions at high temperature involving three Marcus parabolic potential surfaces. Using the nonperturbative Zusman approach, analytical expressions are derived for the superexchange and the sequential electron-transfer rate constants, covering three regimes for the direct vertical energy gap Delta E: the nondegenerate, the degenerate and the quasi-degenerate regimes. For a small Delta E both superexchange and sequential mechanisms can be competing, and the rate constant can deviate significantly from the classical Marcus description which only considers the lowest-order perturbation theory. The novel resonance effects on these two processes due to degenerate energy-level crossing are examined. RP TANG, J (reprint author), ARGONNE NATL LAB,DIV CHEM,9700 S CASS AVE,ARGONNE,IL 60439, USA. RI Tang, Jau/D-8382-2012 OI Tang, Jau/0000-0003-2078-1513 NR 47 TC 2 Z9 2 U1 0 U2 1 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0301-0104 J9 CHEM PHYS JI Chem. Phys. PD DEC 15 PY 1994 VL 189 IS 3 BP 427 EP 442 DI 10.1016/0301-0104(94)00304-1 PG 16 WC Chemistry, Physical; Physics, Atomic, Molecular & Chemical SC Chemistry; Physics GA PX728 UT WOS:A1994PX72800001 ER PT J AU WU, GH TENG, LJ PING, JL WANG, F GOLDMAN, T AF WU, GH TENG, LJ PING, JL WANG, F GOLDMAN, T TI QUARK DELOCALIZATION, COLOR SCREENING AND NUCLEAR INTERMEDIATE RANGE ATTRACTION .2. SO COMMUNICATIONS IN THEORETICAL PHYSICS LA English DT Article ID FERMIONS; STATES AB The center of mass motion effect on the quark delocalization model is to make the effective baryon-baryon (BB) interactions a little less attractive but only a minor correction. The long-range behavior of the color screening potential is not critical for obtaining an intermediate attractive BB interaction. The cluster model and the molecular single quark-basis give exactly the same result. C1 NANJING NORMAL UNIV,DEPT PHYS,NANJING 210024,PEOPLES R CHINA. NANJING UNIV,CTR THEORET PHYS,NANJING 210008,PEOPLES R CHINA. LOS ALAMOS NATL LAB,DIV THEORET,LOS ALAMOS,NM 87545. RP WU, GH (reprint author), SICHUAN UNIV,INST NUCL SCI & TECHNOL,CHENGDU 610064,PEOPLES R CHINA. NR 10 TC 0 Z9 0 U1 0 U2 0 PU HUAZHONG UNIV SCI TECH PRESS PI WUHAN PA WUHAN, PEOPLES R CHINA SN 0253-6102 J9 COMMUN THEOR PHYS JI Commun. Theor. Phys. PD DEC 15 PY 1994 VL 22 IS 4 BP 449 EP 454 PG 6 WC Physics, Multidisciplinary SC Physics GA QH222 UT WOS:A1994QH22200008 ER PT J AU STENGER, JE TEGTMEYER, P MAYR, GA REED, M WANG, Y WANG, P HOUGH, PVC MASTRANGELO, IA AF STENGER, JE TEGTMEYER, P MAYR, GA REED, M WANG, Y WANG, P HOUGH, PVC MASTRANGELO, IA TI P53 OLIGOMERIZATION AND DNA LOOPING ARE LINKED WITH TRANSCRIPTIONAL ACTIVATION SO EMBO JOURNAL LA English DT Article DE ELECTRON MICROSCOPY; OLIGOMERIZATION; P53; TRANSACTIVATION; TUMOR SUPPRESSOR ID WILD-TYPE P53; TATA-BINDING PROTEIN; ENHANCER CONTAINS; GENE-EXPRESSION; DOMAIN; INVITRO; SP1; COMPLEXES; SEQUENCE; TRANSACTIVATION AB We examined the role of p53 oligomerization in DNA binding and in transactivation. By conventional electron microscopy (EM) and scanning transmission EM, we find that wild-type tetramers contact 18-20 bp at single or tandem 19 bp consensus sequences and also stack in apparent register, tetramer on top of tetramer. Stacked tetramers link separated DNA binding sites with DNA loops. Interestingly, the p53(1-320) segment, which lacks the C-terminal tetramerization domain, binds DNA consensus sites as stacked oligomers. Although the truncated protein binds DNA with reduced efficiency, it nevertheless induces DNA looping by self-association. p53, therefore, has a C-terminal tetramerization domain that enhances DNA binding and a non-tetrameric oligomerization domain that stacks p53 at consensus sites and loops separated consensus sites via protein-protein interactions. Using model promoters, we demonstrate that wild-type and tetramerization-deficient p53s activate transcription well when tandem consensus sites are proximal to TATA sequences and poorly when tandem sites are distal, In the presence of proximal sites, however, stimulation by distal sites increases 25-fold. Tetramerization and stacking of tetramers, therefore, provide dual mechanisms to augment the number of p53 molecules available for activation through p53 response elements. DNA looping between separated response elements further increases the concentration of local p53 by translocating distally bound protein to the promoter. C1 BROOKHAVEN NATL LAB,DEPT BIOL,UPTON,NY 11973. SUNY STONY BROOK,DEPT MOLEC GENET & MICROBIOL,STONY BROOK,NY 11794. FU NCI NIH HHS [CA-18808, CA-28148] NR 65 TC 102 Z9 102 U1 0 U2 1 PU OXFORD UNIV PRESS UNITED KINGDOM PI OXFORD PA WALTON ST JOURNALS DEPT, OXFORD, ENGLAND OX2 6DP SN 0261-4189 J9 EMBO J JI Embo J. PD DEC 15 PY 1994 VL 13 IS 24 BP 6011 EP 6020 PG 10 WC Biochemistry & Molecular Biology; Cell Biology SC Biochemistry & Molecular Biology; Cell Biology GA QA637 UT WOS:A1994QA63700025 PM 7813439 ER PT J AU JACQUEY, C WILLIAMS, DJ MCENTIRE, RW LUI, ATY ANGELOPOULOS, V CHRISTON, SP KOKUBUN, S YAMAMOTO, T REEVES, GD BELIAN, RD AF JACQUEY, C WILLIAMS, DJ MCENTIRE, RW LUI, ATY ANGELOPOULOS, V CHRISTON, SP KOKUBUN, S YAMAMOTO, T REEVES, GD BELIAN, RD TI TAILWARD ENERGETIC ION STREAMS OBSERVED AT SIMILAR-TO-100 R(E) BY GEOTAIL EPIC ASSOCIATED WITH GEOMAGNETIC-ACTIVITY INTENSIFICATION SO GEOPHYSICAL RESEARCH LETTERS LA English DT Article ID NEAR-EARTH; SHEET AB We report energetic particle (EPIC instrument) and magnetic field (MGF instrument) measurements collected onboard GEOTAIL located at similar to 100 R(E) downstream in the magnetotail during a 13-hour long active period on January 20-21, 1993. During this period, a series of 6 geomagnetic activity intensifications (breakup or pseudo-breakup) have been studied with ground magnetograms and energetic particle data at geosynchronous orbit. We show that: (1) as a general trend, the level of the energetic ion fluxes was related to the intensity of the westward electrojet; (2) a systematic temporal (within a few minutes) correlation exists between energetic ion flux enhancements observed by GEOTAIL/EPIC in the distant tail and neat-Earth geomagnetic activity intensification onsets; and (3) for 5 of 6 cases, these energetic ion flux enhancements corresponded to strong tailward streams which included particles of both solar wind and ionospheric origin. Their amplitude seemed also to be related to the electrojet intensity change. C1 UNIV MARYLAND,COLLEGE PK,MD 20742. NAGOYA UNIV,STEL,TOYOKAWA 442,JAPAN. INST SPACE & ASTRONAUT SCI,SAGAMIHARA,KANAGAWA 229,JAPAN. LOS ALAMOS NATL LAB,LOS ALAMOS,NM 87545. RP JACQUEY, C (reprint author), JOHNS HOPKINS UNIV,APPL PHYS LAB,JOHNS HOPKINS RD,LAUREL,MD 20723, USA. RI Reeves, Geoffrey/E-8101-2011 OI Reeves, Geoffrey/0000-0002-7985-8098 NR 6 TC 11 Z9 11 U1 0 U2 0 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 SN 0094-8276 J9 GEOPHYS RES LETT JI Geophys. Res. Lett. PD DEC 15 PY 1994 VL 21 IS 25 BP 3015 EP 3018 DI 10.1029/94GL01606 PG 4 WC Geosciences, Multidisciplinary SC Geology GA QA222 UT WOS:A1994QA22200063 ER PT J AU HO, CM TSURUTANI, BT SMITH, EJ FELDMAN, WC AF HO, CM TSURUTANI, BT SMITH, EJ FELDMAN, WC TI A DETAILED EXAMINATION OF A X-LINE REGION IN THE DISTANT TAIL - ISEE-3 OBSERVATIONS OF JET FLOW AND B-Z REVERSALS AND A PAIR OF SLOW SHOCKS SO GEOPHYSICAL RESEARCH LETTERS LA English DT Article ID GEOMAGNETIC TAIL; MODE SHOCKS; PLASMA; MAGNETOTAIL AB We report an observation of Petschek-type magnetic reconnection at a distant neutral line (X = -230 R(e), July 8, 1983) with a full set of signatures of the magnetic merging process. These features include a reversal of plasma flows from earthward to tailward, a pair of slow shocks and the magnetic field X-type line. These two slow shocks are shown to satisfy the shock criteria used by Feldman et al. [1987]. The spacecraft first crosses a slow shock to enter the earthward flowing plasmasheet with velocity of about 440 km/s. The embedded magnetic field has a positive B-z component. The spacecraft next enters a region of tailward plasma flow with speed similar to 670 km/s and an embedded negative B-z, indicating entry into the plasmasheet tailward of the X-line. These observed velocities are comparable to calculated velocities based on Rankine-Hugoniot conservation relationships. The spacecraft subsequently returns into the south tail lobe by crossing another slow shock. Coplanarity analyses show that the two slow shocks have orientations consistent with that predicted by the Petschek reconnection model. We note that this event occurs during northward interplanetary magnetic fields. Thus, a magnetic stress built-up in the distant tail may be responsible for this reconnection process. C1 LOS ALAMOS NATL LAB,LOS ALAMOS,NM 87545. RP HO, CM (reprint author), CALTECH,JET PROP LAB,4800 OAK GROVE DR,PASADENA,CA 91109, USA. NR 13 TC 18 Z9 18 U1 0 U2 2 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 SN 0094-8276 J9 GEOPHYS RES LETT JI Geophys. Res. Lett. PD DEC 15 PY 1994 VL 21 IS 25 BP 3031 EP 3034 DI 10.1029/94GL02096 PG 4 WC Geosciences, Multidisciplinary SC Geology GA QA222 UT WOS:A1994QA22200067 ER PT J AU DOMINGUEZ, D JOSE, JV AF DOMINGUEZ, D JOSE, JV TI NONEQUILIBRIUM COHERENT VORTEX STATES AND SUBHARMONIC GIANT SHAPIRO STEPS IN JOSEPHSON-JUNCTION ARRAYS SO INTERNATIONAL JOURNAL OF MODERN PHYSICS B LA English DT Article ID SUPERCONDUCTING WEAK LINKS; TRANSVERSE MAGNETIC-FIELDS; TWO-DIMENSIONAL ARRAY; DYNAMIC SIMULATIONS; VORTICES; DEPENDENCE; MICROSCOPY; CURRENTS; NETWORK; MOTION AB This is a review of recent work on the dynamic response of Josephson junction arrays driven by dc and ac currents. The arrays are modelled by the resistively shunted Josephson junction model, appropriate for proximity effect junctions, including self-induced magnetic fields as well as disorder. The relevance of the self-induced fields is measured as a function of a parameter kappa = lambda(L/a), with lambda(L) the London penetration depth of the arrays, and a the lattice spacing. The transition from Type II(kappa > 1) to Type I (K < 1) behavior is studied in detail. We compare the results for models with self, self+nearest-neighbor, and full inductance matrices. In the kappa = infinity limit, we find that when the initial state has at least one vortex-antivortex pair, after a characteristic transient time these vortices unbind and radiate other vortices. These radiated vortices settle into a parity-broken, time-periodic, axisymmetric coherent vortex state (ACVS), characterized by alternate rows of positive and negative vortices lying along a tilted axis. The ACVS produces subharmonic steps in the current voltage (IV) characteristics, typical of giant Shapiro steps. For finite kappa we find that the IV's show subharmonic giant Shapiro steps, even at zero external magnetic field. We find that these subharmonic steps are produced by a whole family of coherent vortex oscillating patterns, with their structure changing as a function of kappa. In general, we find that these patterns are due to a breakdown of translational invariance produced, for example, by disorder or antisymmetric edge-fields. The zero field case results are in good qualitative agreement with experiments in Nb-Au-Nb arrays. C1 UNIV UTRECHT,INST THEORET FYS,3508 TA UTRECHT,NETHERLANDS. NORTHEASTERN UNIV,DEPT PHYS,BOSTON,MA 02115. RP DOMINGUEZ, D (reprint author), LOS ALAMOS NATL LAB,DIV THEORET,MS B262,LOS ALAMOS,NM 87545, USA. NR 81 TC 37 Z9 37 U1 0 U2 1 PU WORLD SCIENTIFIC PUBL CO PTE LTD PI SINGAPORE PA JOURNAL DEPT PO BOX 128 FARRER ROAD, SINGAPORE 9128, SINGAPORE SN 0217-9792 J9 INT J MOD PHYS B JI Int. J. Mod. Phys. B PD DEC 15 PY 1994 VL 8 IS 27 BP 3749 EP 3793 DI 10.1142/S0217979294001639 PG 45 WC Physics, Applied; Physics, Condensed Matter; Physics, Mathematical SC Physics GA QE343 UT WOS:A1994QE34300001 ER PT J AU BRANDOW, BH AF BRANDOW, BH TI PHENOMENOLOGY OF THE VALENCE FLUCTUATION PAIRING MECHANISM - T-C SYSTEMATICS OF CUPRATES, AND EVIDENCE FOR THIS MECHANISM IN OTHER SUPERCONDUCTORS SO INTERNATIONAL JOURNAL OF MODERN PHYSICS B LA English DT Review ID UPPER CRITICAL-FIELD; HIGH-TEMPERATURE SUPERCONDUCTORS; PRESSURE ORGANIC SUPERCONDUCTOR; HEAVY-FERMION SUPERCONDUCTORS; COPPER-OXIDE SUPERCONDUCTORS; ELECTRON-PHONON INTERACTIONS; TRANSITION-METAL MONOXIDES; ANDERSON LATTICE MODEL; MUON SPIN RELAXATION; S-CHANNEL THEORY AB The phenomenology of the cuprate superconductors is unconventional in many respects, in addition to the high T-c's. A number of these features have recently been explained, qualitatively and even semi-quantitatively, by means of a valence-fluctuation mechanism. We now examine the extent to which this mechanism can account, at a qualitative level, for the T-c systematics of the many known cuprate superconductors. We find that this mechanism is consistent with some major features of the T-c systematics: the strong dependence on the hole-doping concentration x, the strong correlation with the Madelung potential of the apical oxygens, and a strong dependence on the number of apical oxygens per planar copper ion. We also argue that the same mechanism should be operating (together with phonons) in a number of other superconductors, in particular in the other ''exotic'' superconductors of Uemura. The evidence is that typical features of these exotics include extremely short coherence length, very high (and often T-2) normal-state resistivity, a highly anomalous form of H-c2(T), a large London penetration depth, and an often obvious suitability for representation by an Anderson lattice form of model Hamiltonian. The frequently-encountered cluster and/or reduced-dimensionality aspects are argued to be features which help to justify the latter form of model Hamiltonian. RP BRANDOW, BH (reprint author), LOS ALAMOS NATL LAB,CTR NONLINEAR STUDIES,LOS ALAMOS,NM 87545, USA. NR 170 TC 11 Z9 11 U1 0 U2 2 PU WORLD SCIENTIFIC PUBL CO PTE LTD PI SINGAPORE PA JOURNAL DEPT PO BOX 128 FARRER ROAD, SINGAPORE 9128, SINGAPORE SN 0217-9792 J9 INT J MOD PHYS B JI Int. J. Mod. Phys. B PD DEC 15 PY 1994 VL 8 IS 27 BP 3859 EP 3886 DI 10.1142/S0217979294001664 PG 28 WC Physics, Applied; Physics, Condensed Matter; Physics, Mathematical SC Physics GA QE343 UT WOS:A1994QE34300004 ER PT J AU RENK, TJ AF RENK, TJ TI PLASMA-FILLED APPLIED B ION DIODE EXPERIMENTS USING A PLASMA OPENING SWITCH SO JOURNAL OF APPLIED PHYSICS LA English DT Article ID FUSION; BEAMS RP RENK, TJ (reprint author), SANDIA NATL LABS,POB 5800,ALBUQUERQUE,NM 87185, USA. NR 25 TC 1 Z9 1 U1 0 U2 0 PU AMER INST PHYSICS PI WOODBURY PA CIRCULATION FULFILLMENT DIV, 500 SUNNYSIDE BLVD, WOODBURY, NY 11797-2999 SN 0021-8979 J9 J APPL PHYS JI J. Appl. Phys. PD DEC 15 PY 1994 VL 76 IS 12 BP 7741 EP 7749 DI 10.1063/1.357949 PG 9 WC Physics, Applied SC Physics GA PX184 UT WOS:A1994PX18400011 ER PT J AU HAN, SH GSCHNEIDNER, KA COOK, BA AF HAN, SH GSCHNEIDNER, KA COOK, BA TI THERMOELECTRIC PROPERTIES OF CU-DOPED DYSPROSIUM SESQUISULFIDE SO JOURNAL OF APPLIED PHYSICS LA English DT Article ID LU C1 IOWA STATE UNIV SCI & TECHNOL, AMES LAB, AMES, IA 50011 USA. IOWA STATE UNIV SCI & TECHNOL, DEPT MAT SCI & ENGN, AMES, IA 50011 USA. NR 52 TC 3 Z9 3 U1 0 U2 0 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 DEC 15 PY 1994 VL 76 IS 12 BP 7899 EP 7906 DI 10.1063/1.357900 PG 8 WC Physics, Applied SC Physics GA PX184 UT WOS:A1994PX18400034 ER PT J AU YANG, K EAST, JR HADDAD, GI DRUMMOND, TJ BRENNAN, TM HAMMONS, BE AF YANG, K EAST, JR HADDAD, GI DRUMMOND, TJ BRENNAN, TM HAMMONS, BE TI BUILT-IN BIAXIAL STRAIN DEPENDENCE OF GAMMA-X TRANSPORT IN GAAS/INXAL1-XAS/GAAS PSEUDOMORPHIC HETEROJUNCTION BARRIERS (X=0, 0.03, AND 0.06) SO JOURNAL OF APPLIED PHYSICS LA English DT Article ID CONDUCTION-BAND DISCONTINUITY; MOLECULAR-BEAM EPITAXY; PERPENDICULAR TRANSPORT; TUNNEL STRUCTURES; GAAS; ALXGA1-XAS; ALAS; HETEROSTRUCTURES; MODEL; TRANSITION C1 SANDIA NATL LABS,ALBUQUERQUE,NM 87185. RP YANG, K (reprint author), UNIV MICHIGAN,CTR HIGH FREQUENCY MICROELECTR,DEPT ELECT ENGN & COMP SCI,ANN ARBOR,MI 48109, USA. RI Yang, Kyounghoon/C-1564-2011 NR 34 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 DEC 15 PY 1994 VL 76 IS 12 BP 7907 EP 7914 DI 10.1063/1.357901 PG 8 WC Physics, Applied SC Physics GA PX184 UT WOS:A1994PX18400035 ER PT J AU HEHLEN, MP GUDEL, HU QUAGLIANO, JR AF HEHLEN, MP GUDEL, HU QUAGLIANO, JR TI ELECTRONIC ENERGY-LEVEL STRUCTURE AND CORRELATION CRYSTAL-FIELD EFFECTS OF ER3+ IN CS3LU2BR9 SO JOURNAL OF CHEMICAL PHYSICS LA English DT Article ID ROOM-TEMPERATURE; LASER-EMISSION; ND-3+; HOSTS C1 UNIV BERN,INST ANORGAN CHEM,CH-3000 BERN 9,SWITZERLAND. LOS ALAMOS NATL LAB,DIV CHEM SCI & TECHNOL,LOS ALAMOS,NM 87545. NR 21 TC 19 Z9 19 U1 0 U2 0 PU AMER INST PHYSICS PI WOODBURY PA CIRCULATION FULFILLMENT DIV, 500 SUNNYSIDE BLVD, WOODBURY, NY 11797-2999 SN 0021-9606 J9 J CHEM PHYS JI J. Chem. Phys. PD DEC 15 PY 1994 VL 101 IS 12 BP 10303 EP 10312 DI 10.1063/1.467910 PG 10 WC Chemistry, Physical; Physics, Atomic, Molecular & Chemical SC Chemistry; Physics GA QJ592 UT WOS:A1994QJ59200011 ER PT J AU FURLANETTO, MR THOMAN, JW GRAY, JA PAUL, PH DURANT, JL AF FURLANETTO, MR THOMAN, JW GRAY, JA PAUL, PH DURANT, JL TI NEAR-RESONANT ELECTRONIC-ENERGY TRANSFER IN THE ELECTRONIC QUENCHING OF NO ALPHA(2)SIGMA(+) BY HYDROCARBONS AND AMMONIA SO JOURNAL OF CHEMICAL PHYSICS LA English DT Article ID LASER-INDUCED FLUORESCENCE; MOLECULAR-ENERGIES; 2ND-ROW COMPOUNDS; NITRIC-OXIDE; SHOCK-TUBE; A2-SIGMA+; COMBUSTION; RELAXATION; COLLISIONS; MECHANISM C1 WILLIAMS COLL,DEPT CHEM,WILLIAMSTOWN,MA 01267. SANDIA NATL LABS,COMBUST RES FACIL,LIVERMORE,CA 94551. NR 39 TC 14 Z9 14 U1 0 U2 1 PU AMER INST PHYSICS PI WOODBURY PA CIRCULATION FULFILLMENT DIV, 500 SUNNYSIDE BLVD, WOODBURY, NY 11797-2999 SN 0021-9606 J9 J CHEM PHYS JI J. Chem. Phys. PD DEC 15 PY 1994 VL 101 IS 12 BP 10452 EP 10457 DI 10.1063/1.468441 PG 6 WC Chemistry, Physical; Physics, Atomic, Molecular & Chemical SC Chemistry; Physics GA QJ592 UT WOS:A1994QJ59200027 ER PT J AU HUANG, YH KOURI, DJ HOFFMAN, DK AF HUANG, YH KOURI, DJ HOFFMAN, DK TI GENERAL, ENERGY-SEPARABLE FABER POLYNOMIAL REPRESENTATION OF OPERATOR-FUNCTIONS - THEORY AND APPLICATION IN QUANTUM SCATTERING SO JOURNAL OF CHEMICAL PHYSICS LA English DT Article ID NONSYMMETRIC LINEAR-SYSTEMS; INDEPENDENT WAVEPACKET-SCHRODINGER; LIPPMANN-SCHWINGER EQUATIONS; TCHEBYCHEV ITERATION; TRANSFORM; ALGORITHM; APPROXIMATION; COMPUTATION; ACCURATE; SURFACE C1 UNIV HOUSTON,DEPT PHYS,HOUSTON,TX 77204. IOWA STATE UNIV SCI & TECHNOL,DEPT CHEM,AMES,IA 50011. IOWA STATE UNIV SCI & TECHNOL,AMES LAB,AMES,IA 50011. RP HUANG, YH (reprint author), UNIV HOUSTON,DEPT CHEM,UNIV PK,HOUSTON,TX 77204, USA. NR 52 TC 95 Z9 95 U1 0 U2 0 PU AMER INST PHYSICS PI WOODBURY PA CIRCULATION FULFILLMENT DIV, 500 SUNNYSIDE BLVD, WOODBURY, NY 11797-2999 SN 0021-9606 J9 J CHEM PHYS JI J. Chem. Phys. PD DEC 15 PY 1994 VL 101 IS 12 BP 10493 EP 10506 DI 10.1063/1.468481 PG 14 WC Chemistry, Physical; Physics, Atomic, Molecular & Chemical SC Chemistry; Physics GA QJ592 UT WOS:A1994QJ59200033 ER PT J AU PALMER, BJ LO, CM AF PALMER, BJ LO, CM TI MOLECULAR-DYNAMICS IMPLEMENTATION OF THE GIBBS ENSEMBLE CALCULATION SO JOURNAL OF CHEMICAL PHYSICS LA English DT Article ID CANONICAL ENSEMBLE; MONTE-CARLO; SIMULATIONS; TEMPERATURE; WATER RP PALMER, BJ (reprint author), PACIFIC NW LAB, DEPT ANALYT SCI, RICHLAND, WA 99352 USA. NR 16 TC 27 Z9 28 U1 0 U2 6 PU AMER INST PHYSICS PI WOODBURY PA CIRCULATION FULFILLMENT DIV, 500 SUNNYSIDE BLVD, WOODBURY, NY 11797-2999 SN 0021-9606 J9 J CHEM PHYS JI J. Chem. Phys. PD DEC 15 PY 1994 VL 101 IS 12 BP 10899 EP 10907 DI 10.1063/1.468440 PG 9 WC Chemistry, Physical; Physics, Atomic, Molecular & Chemical SC Chemistry; Physics GA QJ592 UT WOS:A1994QJ59200072 ER PT J AU RUSCIC, B BERKOWITZ, J AF RUSCIC, B BERKOWITZ, J TI THE HEATS OF FORMATION OF SOME C2H5O+ ISOMERS, RELEVANT BOND-ENERGIES IN ETHANOL AND PA(CH3CHO) SO JOURNAL OF CHEMICAL PHYSICS LA English DT Article ID DISSOCIATION ENERGIES; STRUCTURAL ISOMERS; PHOTOIONIZATION; ETHYLENE; PHOTODISSOCIATION; 2-BROMOETHANOL; IDENTIFICATION; SPECTROSCOPY; AFFINITIES; ENOLS RP RUSCIC, B (reprint author), ARGONNE NATL LAB,DIV CHEM,ARGONNE,IL 60439, USA. RI Ruscic, Branko/A-8716-2008 OI Ruscic, Branko/0000-0002-4372-6990 NR 45 TC 70 Z9 70 U1 2 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 DEC 15 PY 1994 VL 101 IS 12 BP 10936 EP 10946 DI 10.1063/1.467843 PG 11 WC Chemistry, Physical; Physics, Atomic, Molecular & Chemical SC Chemistry; Physics GA QJ592 UT WOS:A1994QJ59200076 ER PT J AU ENGELKE, R BLAIS, NC AF ENGELKE, R BLAIS, NC TI CHEMICAL DIMERIZATION OF CRYSTALLINE ANTHRACENE PRODUCED BY TRANSIENT HIGH-PRESSURE SO JOURNAL OF CHEMICAL PHYSICS LA English DT Article ID SHOCK WAVE COMPRESSION; PHASE-TRANSITIONS; BENZENE; INTERFEROMETER; STATE; GPA RP ENGELKE, R (reprint author), LOS ALAMOS NATL LAB,POB 1663,LOS ALAMOS,NM 87545, USA. NR 29 TC 21 Z9 21 U1 0 U2 6 PU AMER INST PHYSICS PI WOODBURY PA CIRCULATION FULFILLMENT DIV, 500 SUNNYSIDE BLVD, WOODBURY, NY 11797-2999 SN 0021-9606 J9 J CHEM PHYS JI J. Chem. Phys. PD DEC 15 PY 1994 VL 101 IS 12 BP 10961 EP 10972 DI 10.1063/1.467846 PG 12 WC Chemistry, Physical; Physics, Atomic, Molecular & Chemical SC Chemistry; Physics GA QJ592 UT WOS:A1994QJ59200079 ER PT J AU TEO, CK RUANO, OA WADSWORTH, J SHERBY, OD AF TEO, CK RUANO, OA WADSWORTH, J SHERBY, OD TI SUPERPLASTIC BEHAVIOR OF A CERAMIC-BASED KAPPA-ALPHA-FE-10AL-1.9C MATERIAL SO JOURNAL OF MATERIALS SCIENCE LA English DT Article AB A fine microstructure has been developed in a Fe-10Al-1.9C material made from rapidly solidified powders. The compacted material had a microstructure containing about 50 vol% kappa phase (Fe3AlC(x)) and 50 vol% alpha phase. The creep behaviour of the material was investigated using tension and compression change in strain rate tests and elongation to failure tests. Stress exponents of 2-3 were obtained over a wide range of strain rates, and an average activation energy for creep of 245 kJ mol-1 was determined. A maximum elongation to failure of 1120% was obtained at 900-degrees-C. The tensile ductility as a function of strain rate was found to follow the same behaviour of other ceramic materials wherein the elongation to failure decreases sharply with an increase in strain rate. C1 CSIC,CTR NACL INVEST MET,E-28040 MADRID,SPAIN. LAWRENCE LIVERMORE NATL LAB,LIVERMORE,CA 94550. STANFORD UNIV,DEPT MAT SCI & ENGN,STANFORD,CA 94305. RP TEO, CK (reprint author), ORDNANCE DEV & ENGN,15 CHIN BEE DR,SINGAPORE 2261,SINGAPORE. RI Ruano, Oscar/H-1835-2015 OI Ruano, Oscar/0000-0001-6368-986X NR 13 TC 7 Z9 7 U1 1 U2 2 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 DEC 15 PY 1994 VL 29 IS 24 BP 6581 EP 6586 DI 10.1007/BF00354024 PG 6 WC Materials Science, Multidisciplinary SC Materials Science GA QA323 UT WOS:A1994QA32300033 ER PT J AU BAMBERGER, CE AF BAMBERGER, CE TI THE PSEUDOMORPHIC CONVERSION OF ACICULAR CRYSTALS OF SODIUM TUNGSTEN BRONZE INTO WC/W SO JOURNAL OF MATERIALS SCIENCE LETTERS LA English DT Article RP BAMBERGER, CE (reprint author), OAK RIDGE NATL LAB,DIV CHEM,POB 2008,OAK RIDGE,TN 37831, USA. NR 1 TC 2 Z9 2 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 DEC 15 PY 1994 VL 13 IS 24 BP 1742 EP 1745 DI 10.1007/BF00776343 PG 4 WC Materials Science, Multidisciplinary SC Materials Science GA QA321 UT WOS:A1994QA32100004 ER PT J AU PFUND, DM DARAB, JG FULTON, JL MA, YJ AF PFUND, DM DARAB, JG FULTON, JL MA, YJ TI AN XAFS STUDY OF STRONTIUM IONS AND KRYPTON IN SUPERCRITICAL WATER SO JOURNAL OF PHYSICAL CHEMISTRY LA English DT Letter ID AQUEOUS-SOLUTIONS; RAMAN-SPECTROSCOPY; CONTINUUM MODEL; ALKALINE-EARTH; FLUIDS; ELECTROLYTES; CHEMISTRY; SOLVATION AB We present the first direct measurement of ion hydration in supercritical water using X-ray absorption fine structure (XAFS). Radial structure functions were determined for strontium ions in supercritical water at 385 degrees C and 269-339 bar at a concentration of strontium of 0.2 M. For supercritical water, at a temperature of 385 degrees C and density of 0.54 g/cm(3), the number of waters of hydration was a factor of 0.52 of the number in liquid water under ambient conditions. The radius of the first solvation shell changes very little at these elevated temperatures. This large local depletion of water around the ion would affect the short-range interactions with counterions and may increase the ion reactivity. We also report XAFS results for krypton in supercritical water and show that, in contrast to strontium ions, the local solvent environment is more gaslike in the first few solvation shells of the krypton atom. C1 PACIFIC NW LAB, DEPT CHEM SCI, RICHLAND, WA 99352 USA. UNIV WASHINGTON, DEPT PHYS, SEATTLE, WA 98195 USA. NR 36 TC 95 Z9 96 U1 0 U2 4 PU AMER CHEMICAL SOC PI WASHINGTON PA PO BOX 57136, WASHINGTON, DC 20037-0136 SN 0022-3654 J9 J PHYS CHEM-US JI J. Phys. Chem. PD DEC 15 PY 1994 VL 98 IS 50 BP 13102 EP 13107 DI 10.1021/j100101a002 PG 6 WC Chemistry, Physical SC Chemistry GA PX992 UT WOS:A1994PX99200002 ER PT J AU SHKROB, IA TRIFUNAC, AD AF SHKROB, IA TRIFUNAC, AD TI FDMR IN LOW-TEMPERATURE SOLIDS .1. THEORY SO JOURNAL OF PHYSICAL CHEMISTRY LA English DT Article ID DETECTED MAGNETIC-RESONANCE; ALKANE RADICAL-CATIONS; ELECTRON-PARAMAGNETIC RESONANCE; OD ESR TECHNIQUE; PULSE-RADIOLYSIS; TRAPPED ELECTRONS; 2-PHOTON IONIZATION; EXCIPLEX SYSTEMS; CONDENSED PHASE; TIME AB Various mechanisms of geminate recombination in spin-correlated radical ion pairs produced by radiolysis of organic solids under cryogenic conditions are considered and compared with experimental data. Single-step electron tunneling and slow resonant hole transfer are examined from the viewpoint of their manifestation in pulsed time-resolved fluorescence-detected magnetic resonance (FDMR). Two theoretical models treating the phenomenon are developed, and their predictions are compared with the experimental results. These models are found to be consistent with many observed features: t(-1) decay kinetics, unusual evolution of the FDMR spectra with time, narrow radial distribution of the FDMR-active pairs, and efficient spin memory transfer from the primary pairs. However, with very few exceptions the tunneling theories fail to reproduce the exact scale of the effect and its dependence on solute concentration and thermalization distance of electrons. This discrepancy suggests that the negative charge is more mobile than predicted by the single-step tunneling model. RP SHKROB, IA (reprint author), ARGONNE NATL LAB,DIV CHEM,9700 S CASS AVE,ARGONNE,IL 60439, USA. NR 82 TC 7 Z9 7 U1 0 U2 1 PU AMER CHEMICAL SOC PI WASHINGTON PA PO BOX 57136, WASHINGTON, DC 20037-0136 SN 0022-3654 J9 J PHYS CHEM-US JI J. Phys. Chem. PD DEC 15 PY 1994 VL 98 IS 50 BP 13249 EP 13261 DI 10.1021/j100101a027 PG 13 WC Chemistry, Physical SC Chemistry GA PX992 UT WOS:A1994PX99200027 ER PT J AU SHKROB, IA WERST, DW TRIFUNAC, AD AF SHKROB, IA WERST, DW TRIFUNAC, AD TI FDMR IN LOW-TEMPERATURE SOLIDS .2. OBSERVATION OF WEAKLY-BOUND ELECTRONS SO JOURNAL OF PHYSICAL CHEMISTRY LA English DT Article ID DETECTED MAGNETIC-RESONANCE; ALKANE RADICAL-CATIONS; OD ESR TECHNIQUE; PICOSECOND PULSE-RADIOLYSIS; IRRADIATED SINGLE-CRYSTALS; TRAPPED ELECTRONS; PARAMAGNETIC RESONANCE; AROMATIC-HYDROCARBONS; 2-PHOTON IONIZATION; SPECTRA AB Time-resolved fluorescence-detected magnetic resonance (FDMR) was used to study radiolysis of organic solids at low temperatures (4-30 K). The mobility of charges generated in the primary events of solid-state radiolysis may be accounted for by two mechanisms: single-step tunneling and relatively slow (10(6)-10(7) s(-1)) resonant charge transfer involving the solvent hole. Acting together, these mechanisms engender a variety of unusual and previously unknown spectral features. Although the tunneling satisfactorily explains FDMR behavior in general, quantitative agreement is poor, particularly for donor-acceptor systems. It appears that the origin of this discrepancy lays in an underestimation of the tunneling radii in reactions of negative charges. The latter is rationalized in terms of a selectivity of FDMR toward mobile weakly bound electrons and excited radical anions formed after electron scavenging. The possible nature of these weakly bound electronic states is discussed. C1 ARGONNE NATL LAB, DIV CHEM, ARGONNE, IL 60439 USA. NR 86 TC 10 Z9 10 U1 0 U2 1 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 0022-3654 J9 J PHYS CHEM-US JI J. Phys. Chem. PD DEC 15 PY 1994 VL 98 IS 50 BP 13262 EP 13279 DI 10.1021/j100101a028 PG 18 WC Chemistry, Physical SC Chemistry GA PX992 UT WOS:A1994PX99200028 ER PT J AU BLATTER, F MOREAU, F FREI, H AF BLATTER, F MOREAU, F FREI, H TI DIFFUSE-REFLECTANCE SPECTROSCOPY OF VISIBLE ALKENE-O-2 CHARGE-TRANSFER ABSORPTIONS IN ZEOLITE-Y AND DETERMINATION OF PHOTOOXYGENATION QUANTUM EFFICIENCIES SO JOURNAL OF PHYSICAL CHEMISTRY LA English DT Article ID CRYOGENIC OXYGEN MATRIX; ELECTRIC-FIELD; PHOTOCHEMICAL-REACTIONS; TRANSFER COMPLEXES; METHANE MOLECULE; SUPERCAGES; BAND; 2,3-DIMETHYL-2-BUTENE; CRYSTALS; SPECTRA AB Very large red shifts of charge-transfer bands of 2,3-dimethyl-2-butene.O-2, 2-methyl-2-butene.O-2, and trans-2-butene.O-2 complexes in zeolite NaY have been observed by diffuse reflectance spectroscopy. Absorption tails are shifted by over 10 000 cm(-1) compared to gas phase, solution, or solid oxygen matrix. In zeolite BaY with its divalent counterions, the 2-butene.O-2 absorption is further red shifted by several thousand wavenumbers. This points to stabilization of the excited charge-transfer states by the very strong electrostatic fields inside the zeolite cages as the origin of the observed red shifts. Reaction quantum efficiencies of previously reported selective photooxygenations of these alkenes by visible light are estimated on the basis of these spectra and found to be in the range 0.1-0.3. C1 UNIV CALIF BERKELEY,LAWRENCE BERKELEY LAB,CHEM BIODYNAM LAB,BERKELEY,CA 94720. NR 43 TC 59 Z9 60 U1 0 U2 1 PU AMER CHEMICAL SOC PI WASHINGTON PA PO BOX 57136, WASHINGTON, DC 20037-0136 SN 0022-3654 J9 J PHYS CHEM-US JI J. Phys. Chem. PD DEC 15 PY 1994 VL 98 IS 50 BP 13403 EP 13407 DI 10.1021/j100101a046 PG 5 WC Chemistry, Physical SC Chemistry GA PX992 UT WOS:A1994PX99200046 ER PT J AU KOLACZKOWSKI, SV HAYES, JM SMALL, GJ AF KOLACZKOWSKI, SV HAYES, JM SMALL, GJ TI A THEORY OF DISPERSIVE KINETICS IN THE ENERGY-TRANSFER OF ANTENNA COMPLEXES SO JOURNAL OF PHYSICAL CHEMISTRY LA English DT Article ID BACTERIOCHLOROPHYLL A-PROTEIN; EXCITED-STATE STRUCTURE; RHODOBACTER-SPHAEROIDES; TRANSFER DYNAMICS; REACTION CENTERS; PHOTOSYSTEM-II; PROSTHECOCHLORIS-AESTUARII; MASTIGOCLADUS-LAMINOSUS; 3-DIMENSIONAL STRUCTURE; CHARGE SEPARATION AB The inherent glasslike structural heterogeneity of photosynthetic antenna protein complexes is now known to result in a distribution of values for any given donor-acceptor energy gap. The width of the distribution is sufficiently broad to raise the possibility that the kinetics of D-A energy transfer might be dispersive and strongly dependent on temperature especially since the chlorophyll optical transitions are characterized by weak electron-phonon coupling. An approximate theory is presented that allows far computationally simple analysis of this problem. It is based on the familiar nonadiabatric energy-transfer theory and Condon approximation and, thus, is applicable to conventional Forster transfer involving localized phonons. The case of delocalized phonons is also treated. Calculations are presented for a model D-A system which, based on hole-burning data, can be considered to be realistic and typical of many complexes. The results reveal pronounced and temperature-dependent dispersion in the kinetics. The effect of pure electronic dephasing on the calculated results is considered. The theory is not applicable to the situation where excitonic level splittings are large relative to the pure dephasing frequencies of the levels. i.e., where one has to go beyond the Condon approximation. Nevertheless. the theory can be easily extended to cover this strong coupling case which can be expected to be important for many photosynthetic complexes at sufficiently low temperatures. The possibility that strong coupling might lead to a diminuation in the degree of dispersive kinetics is considered. C1 IOWA STATE UNIV SCI & TECHNOL,DEPT CHEM,AMES,IA 50011. IOWA STATE UNIV SCI & TECHNOL,US DOE,AMES LAB,AMES,IA 50011. RP KOLACZKOWSKI, SV (reprint author), UNIV ST THOMAS,DEPT CHEM,2115 SUMMIT AVE,ST PAUL,MN 55105, USA. NR 65 TC 33 Z9 34 U1 1 U2 1 PU AMER CHEMICAL SOC PI WASHINGTON PA PO BOX 57136, WASHINGTON, DC 20037-0136 SN 0022-3654 J9 J PHYS CHEM-US JI J. Phys. Chem. PD DEC 15 PY 1994 VL 98 IS 50 BP 13418 EP 13425 DI 10.1021/j100101a049 PG 8 WC Chemistry, Physical SC Chemistry GA PX992 UT WOS:A1994PX99200049 ER PT J AU TESKE, E VANHEERDE, P RUTTEMAN, GR KURZMAN, ID MOORE, PF MACEWEN, EG AF TESKE, E VANHEERDE, P RUTTEMAN, GR KURZMAN, ID MOORE, PF MACEWEN, EG TI PROGNOSTIC FACTORS FOR TREATMENT OF MALIGNANT-LYMPHOMA IN DOGS SO JOURNAL OF THE AMERICAN VETERINARY MEDICAL ASSOCIATION LA English DT Article ID NON-HODGKINS-LYMPHOMAS; NATIVE L-ASPARAGINASE; LARGE-CELL LYMPHOMA; CANINE LYMPHOMA; CHEMOTHERAPY; LYMPHOSARCOMA; DOXORUBICIN; MANAGEMENT; RECEPTORS; ANTIBODY AB Pretreatment characteristics of 138 dogs with malignant lymphoma were analyzed to determine prognostic factors associated with outcome (ie, complete response rate, time to relapse after complete response, survival time). Dogs were all treated for 10 weeks, wing a standard induction chemotherapy protocol, and were then given asparaginase weekly. Once the disease became progressive, second-line chemotherapy was instituted. Age, sex, weight, clinical stage, performance grade, immunophenotype, and malignancy grade assigned according to the National Cancer Institute's Working Formulation were not associated with complete response rate. However, malignancy grade assigned according to the Kiel classification was found to be associated with complete response rate, dogs with high-grade malignancies had a significantly higher complete response rate than did dogs with low-grade malignancies. By means of multivariate analysis, clinical stage and immunophenotype were found to be prognostic factors for time to relapse (among dogs that had had a complete response) and survival time. In addition, malignancy grade assigned according to the Kiel classification was found to be a prognostic factor for time to relapse, whereas, malignancy grade assigned according to the Working Formulation was determined to be a prognostic factor for survival time. C1 NETHERLANDS CANC INST,DEPT PATHOL,1066 CX AMSTERDAM,NETHERLANDS. UNIV WISCONSIN,SCH VET MED,DEPT MED SCI,MADISON,WI 53706. LAWRENCE LIVERMORE NATL LAB,SCH VET MED,DEPT VET PATHOL,DAVIS,CA 95616. RP TESKE, E (reprint author), UNIV UTRECHT,DEPT CLIN SCI COMPAN ANIM,UTRECHT 3508,NETHERLANDS. NR 30 TC 146 Z9 149 U1 1 U2 9 PU AMER VETERINARY MEDICAL ASSOC PI SCHAUMBURG PA 1931 N MEACHAM RD SUITE 100, SCHAUMBURG, IL 60173-4360 SN 0003-1488 J9 J AM VET MED ASSOC JI J. Am. Vet. Med. Assoc. PD DEC 15 PY 1994 VL 205 IS 12 BP 1722 EP 1728 PG 7 WC Veterinary Sciences SC Veterinary Sciences GA PW606 UT WOS:A1994PW60600017 PM 7744644 ER PT J AU DEMAREE, RS FLORY, WB GIBERSON, RT PUSHNIK, JC HOUPIS, JL AF DEMAREE, RS FLORY, WB GIBERSON, RT PUSHNIK, JC HOUPIS, JL TI USING REDUCED OSMIUM IN IMMUNOELECTRON MICROSCOPY SO MICROSCOPY RESEARCH AND TECHNIQUE LA English DT Meeting Abstract C1 CALIF STATE UNIV LOS ANGELES,DEPT SCI BIOL,CHICO,CA 95929. TED PELLA INC,REDDING,CA 96049. LAWRENCE LIVERMORE NATL LAB,LIVERMORE,CA 94550. NR 0 TC 0 Z9 0 U1 0 U2 0 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 DEC 15 PY 1994 VL 29 IS 6 BP 492 EP 492 PG 1 WC Anatomy & Morphology; Biology; Microscopy SC Anatomy & Morphology; Life Sciences & Biomedicine - Other Topics; Microscopy GA QF939 UT WOS:A1994QF93900008 ER PT J AU FLORY, WB DEMAREE, RS PUSHNIK, JC HOUPIS, JL AF FLORY, WB DEMAREE, RS PUSHNIK, JC HOUPIS, JL TI THE EFFECT OF ELEVATED CARBON-DIOXIDE ON THE NEEDLE MORPHOLOGY OF 2 DISTINCT CONIFER SPECIES SO MICROSCOPY RESEARCH AND TECHNIQUE LA English DT Meeting Abstract C1 CALIF STATE UNIV LOS ANGELES,DEPT SCI BIOL,CHICO,CA 95929. LAWRENCE LIVERMORE NATL LAB,LIVERMORE,CA 94550. NR 0 TC 0 Z9 0 U1 1 U2 1 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 DEC 15 PY 1994 VL 29 IS 6 BP 493 EP 493 PG 1 WC Anatomy & Morphology; Biology; Microscopy SC Anatomy & Morphology; Life Sciences & Biomedicine - Other Topics; Microscopy GA QF939 UT WOS:A1994QF93900010 ER PT J AU MONGER, HC COLE, DR AF MONGER, HC COLE, DR TI CLIMATE, CO2 AND PLANT ABUNDANCE - REPLY SO NATURE LA English DT Letter ID ICE CORE; ATMOSPHERIC CO2; RECORD C1 OAK RIDGE NATL LAB, DIV CHEM & ANALYT SCI, OAK RIDGE, TN 37831 USA. RP MONGER, HC (reprint author), NEW MEXICO STATE UNIV, DEPT AGRON & HORT, LAS CRUCES, NM 88003 USA. NR 11 TC 0 Z9 0 U1 0 U2 2 PU NATURE PUBLISHING GROUP PI LONDON PA MACMILLAN BUILDING, 4 CRINAN ST, LONDON N1 9XW, ENGLAND SN 0028-0836 J9 NATURE JI Nature PD DEC 15 PY 1994 VL 372 IS 6507 BP 626 EP 626 DI 10.1038/372626a0 PG 1 WC Multidisciplinary Sciences SC Science & Technology - Other Topics GA PX307 UT WOS:A1994PX30700064 ER PT J AU BARTON, DS AF BARTON, DS TI CONTROLS FOR RHIC, A PROGRESS REPORT SO NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH SECTION A-ACCELERATORS SPECTROMETERS DETECTORS AND ASSOCIATED EQUIPMENT LA English DT Article; Proceedings Paper CT 3rd International Conference on Accelerator and Large Experimental Physics Control Systems CY OCT 18-23, 1993 CL BERLIN, GERMANY SP HAHN MEITNER INST BERLIN GMBH, EPS IDG PHYS CONTROL SYST, EUROPEAN PHYS SOC, GERMAN PHYS SOC, ASSOC ASIAN PACIFIC PHYS SOC, IEEE, NUCL & PLASMA SCI SOC AB While the Relativistic Heavy Ion Collider presents problems neither of great size nor of state-of-the-art mechanical stability as found in other new accelerators, its control system must provide flexible, expandable connections between the operations and physics staff and the machine. The control system architecture is hierarchical in nature and consists of two physical layers with a fibre-optic network connection. The Console Level nodes including file-, database- and compute-servers are UNIX workstations. The Front End Level systems comprise VME crates with processors running the VxWorks real-time operating system. Accelerator devices are implemented as objects in C++. The network will be implemented using either FDDI or ATM technology, with bridges to Ethernet for connection to individual front ends. Specialized hardware modules are being designed for waveform control of power supplies, multiplexed signal acquisition, and timing services. Connection to slow systems will generally be made via VME interfaces to industrial PLC systems. The main features of the control system conceptual design are discussed, along with a progress report on controls development and RHIC construction. RP BARTON, DS (reprint author), BROOKHAVEN NATL LAB,UPTON,NY 11973, USA. NR 7 TC 0 Z9 0 U1 0 U2 0 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0168-9002 J9 NUCL INSTRUM METH A JI Nucl. Instrum. Methods Phys. Res. Sect. A-Accel. Spectrom. Dect. Assoc. Equip. PD DEC 15 PY 1994 VL 352 IS 1-2 BP 6 EP 12 DI 10.1016/0168-9002(94)91448-6 PG 7 WC Instruments & Instrumentation; Nuclear Science & Technology; Physics, Nuclear; Physics, Particles & Fields SC Instruments & Instrumentation; Nuclear Science & Technology; Physics GA QA953 UT WOS:A1994QA95300003 ER PT J AU MCDOWELL, W KNOTT, M KRAIMER, M AF MCDOWELL, W KNOTT, M KRAIMER, M TI STATUS OF THE ADVANCED PHOTON SOURCE AND ITS ACCELERATOR CONTROL-SYSTEM SO NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH SECTION A-ACCELERATORS SPECTROMETERS DETECTORS AND ASSOCIATED EQUIPMENT LA English DT Article; Proceedings Paper CT 3rd International Conference on Accelerator and Large Experimental Physics Control Systems CY OCT 18-23, 1993 CL BERLIN, GERMANY SP HAHN MEITNER INST BERLIN GMBH, EPS IDG PHYS CONTROL SYST, EUROPEAN PHYS SOC, GERMAN PHYS SOC, ASSOC ASIAN PACIFIC PHYS SOC, IEEE, NUCL & PLASMA SCI SOC AB This paper presents the current status of the Advanced Photon Source (APS), its control system and the Experimental Physics and Industrial Control System (EPICS) tools being used to implement this control system. The status of the physical plant and each of the accelerators as well as detailed descriptions of the software tools used to build the accelerator control system are presented. The control system uses high-performance graphic workstations and the X-Windows graphical user interface (GUI) at the operator interface level. It connects to VME/VXI-based microprocessors at the field level, using TCP/IP protocols over high-performance networks. This strategy assures the flexibility and expansibility of the control system. A defined interface between the system components will allow the system to evolve with the direct addition of future, improved equipment and new capabilities. RP MCDOWELL, W (reprint author), ARGONNE NATL LAB,ADV PHOTON SOURCE,9700 S CASS AVE,ARGONNE,IL 60439, USA. NR 0 TC 2 Z9 2 U1 0 U2 0 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0168-9002 J9 NUCL INSTRUM METH A JI Nucl. Instrum. Methods Phys. Res. Sect. A-Accel. Spectrom. Dect. Assoc. Equip. PD DEC 15 PY 1994 VL 352 IS 1-2 BP 13 EP 15 DI 10.1016/0168-9002(94)91449-4 PG 3 WC Instruments & Instrumentation; Nuclear Science & Technology; Physics, Nuclear; Physics, Particles & Fields SC Instruments & Instrumentation; Nuclear Science & Technology; Physics GA QA953 UT WOS:A1994QA95300004 ER PT J AU YOUNG, J BROWN, W CORK, C FOWLER, K GIMPEL, T LEWIS, S MCEVOY, M MEANEY, D MOLINARI, P PETERSON, D PORTMANN, G ROBB, A TIMOSSI, C AF YOUNG, J BROWN, W CORK, C FOWLER, K GIMPEL, T LEWIS, S MCEVOY, M MEANEY, D MOLINARI, P PETERSON, D PORTMANN, G ROBB, A TIMOSSI, C TI STATUS-REPORT ON THE ADVANCED LIGHT-SOURCE CONTROL-SYSTEM, 1993 SO NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH SECTION A-ACCELERATORS SPECTROMETERS DETECTORS AND ASSOCIATED EQUIPMENT LA English DT Article; Proceedings Paper CT 3rd International Conference on Accelerator and Large Experimental Physics Control Systems CY OCT 18-23, 1993 CL BERLIN, GERMANY SP HAHN MEITNER INST BERLIN GMBH, EPS IDG PHYS CONTROL SYST, EUROPEAN PHYS SOC, GERMAN PHYS SOC, ASSOC ASIAN PACIFIC PHYS SOC, IEEE, NUCL & PLASMA SCI SOC AB Advanced Light Source (ALS), under construction for the past seven years, has become operational. The accelerator has been successfully commissioned using a control system based on hundreds of controllers of our own design and high performance personal computers which form the operator interface. The first beamlines are being commissioned using a control system based on VME hardware and the Experimental Physics and Industrial Control System (EPICS) software. The two systems are being integrated and this paper reports on the current work. RP YOUNG, J (reprint author), UNIV CALIF BERKELEY,LAWRENCE BERKELEY LAB,BERKELEY,CA 94720, USA. NR 5 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 DEC 15 PY 1994 VL 352 IS 1-2 BP 112 EP 113 DI 10.1016/0168-9002(94)91474-5 PG 2 WC Instruments & Instrumentation; Nuclear Science & Technology; Physics, Nuclear; Physics, Particles & Fields SC Instruments & Instrumentation; Nuclear Science & Technology; Physics GA QA953 UT WOS:A1994QA95300029 ER PT J AU SMITH, JD RAMAMOORTHY, S TANG, YN AF SMITH, JD RAMAMOORTHY, S TANG, YN TI NSLS CONTROL-SYSTEM UPGRADE SO NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH SECTION A-ACCELERATORS SPECTROMETERS DETECTORS AND ASSOCIATED EQUIPMENT LA English DT Article; Proceedings Paper CT 3rd International Conference on Accelerator and Large Experimental Physics Control Systems CY OCT 18-23, 1993 CL BERLIN, GERMANY SP HAHN MEITNER INST BERLIN GMBH, EPS IDG PHYS CONTROL SYST, EUROPEAN PHYS SOC, GERMAN PHYS SOC, ASSOC ASIAN PACIFIC PHYS SOC, IEEE, NUCL & PLASMA SCI SOC AB The NSLS consists of two storage rings, a booster and a linac. A major upgrade of the control system (installed in 1978) was undertaken and has been completed. The computer architecture is being changed from a three level star-network to a two level distributed system. The microprocessor subsystem, host computer and workstations, communication link and the main software components are being upgraded or replaced. Since the NSLS rings operate twenty four hours a day a year with minimum maintenance time, the key requirement during the upgrade phase is a non-disruptive transition with minimum downtime. Concurrent with the upgrade, some immediate improvements were required. This paper describes the various components of the upgraded system and outlines the future plans. RP SMITH, JD (reprint author), BROOKHAVEN NATL LAB,NATL SYNCHROTRON LIGHT SOURCE DEPT,UPTON,NY 11973, USA. NR 3 TC 2 Z9 2 U1 0 U2 0 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0168-9002 J9 NUCL INSTRUM METH A JI Nucl. Instrum. Methods Phys. Res. Sect. A-Accel. Spectrom. Dect. Assoc. Equip. PD DEC 15 PY 1994 VL 352 IS 1-2 BP 114 EP 117 DI 10.1016/0168-9002(94)91475-3 PG 4 WC Instruments & Instrumentation; Nuclear Science & Technology; Physics, Nuclear; Physics, Particles & Fields SC Instruments & Instrumentation; Nuclear Science & Technology; Physics GA QA953 UT WOS:A1994QA95300030 ER PT J AU MORRIS, JT AF MORRIS, JT TI OBJECT-ORIENTED DESIGN IN THE AGSDCS ALARM SYSTEM SO NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH SECTION A-ACCELERATORS SPECTROMETERS DETECTORS AND ASSOCIATED EQUIPMENT LA English DT Article; Proceedings Paper CT 3rd International Conference on Accelerator and Large Experimental Physics Control Systems CY OCT 18-23, 1993 CL BERLIN, GERMANY SP HAHN MEITNER INST BERLIN GMBH, EPS IDG PHYS CONTROL SYST, EUROPEAN PHYS SOC, GERMAN PHYS SOC, ASSOC ASIAN PACIFIC PHYS SOC, IEEE, NUCL & PLASMA SCI SOC AB The alarm subsystem of the Alternating Gradient Synchrotron Distributed Control System (AGSDCS) has been redesigned to enhance reliability, flexibility, and ease of maintenance. The alarm system is functionally divided into Alarm Generators, Alarm Displays, and a central Alarm Receiver. The task was simplified by defining a set of C+ + classes that could be reused by all components of the alarm system. The AlarmData class represents instances of alarm conditions. The AlarmFilter class is used by both the Alarm Receiver and Alarm Displays to select the alarms that are of interest to a particular user. The AlarmDatabase class is used by the Alarm Receiver to manage the central alarm database. The Alarm Displays use the AlarmDatabase class to manage the local database representing the alarms on their screens. RP MORRIS, JT (reprint author), BROOKHAVEN NATL LAB,DEPT AGS,UPTON,NY 11973, USA. NR 1 TC 0 Z9 0 U1 0 U2 0 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0168-9002 J9 NUCL INSTRUM METH A JI Nucl. Instrum. Methods Phys. Res. Sect. A-Accel. Spectrom. Dect. Assoc. Equip. PD DEC 15 PY 1994 VL 352 IS 1-2 BP 141 EP 143 DI 10.1016/0168-9002(94)91483-4 PG 3 WC Instruments & Instrumentation; Nuclear Science & Technology; Physics, Nuclear; Physics, Particles & Fields SC Instruments & Instrumentation; Nuclear Science & Technology; Physics GA QA953 UT WOS:A1994QA95300038 ER PT J AU DALESIO, LR HILL, JO KRAIMER, M LEWIS, S MURRAY, D HUNT, S WATSON, W CLAUSEN, M DALESIO, J AF DALESIO, LR HILL, JO KRAIMER, M LEWIS, S MURRAY, D HUNT, S WATSON, W CLAUSEN, M DALESIO, J TI THE EXPERIMENTAL PHYSICS AND INDUSTRIAL CONTROL-SYSTEM ARCHITECTURE - PAST, PRESENT, AND FUTURE SO NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH SECTION A-ACCELERATORS SPECTROMETERS DETECTORS AND ASSOCIATED EQUIPMENT LA English DT Article; Proceedings Paper CT 3rd International Conference on Accelerator and Large Experimental Physics Control Systems CY OCT 18-23, 1993 CL BERLIN, GERMANY SP HAHN MEITNER INST BERLIN GMBH, EPS IDG PHYS CONTROL SYST, EUROPEAN PHYS SOC, GERMAN PHYS SOC, ASSOC ASIAN PACIFIC PHYS SOC, IEEE, NUCL & PLASMA SCI SOC AB The Experimental Physics and Industrial Control System (EPICS), has been used at a number of sites for performing data acquisition, supervisory control, closed-loop control, sequential control, and operational optimization. The EPICS architecture was originally developed by a group with diverse backgrounds in physics and industrial control. The current architecture represents one instance of the ''standard model''. It provides distributed processing and communication from any local area network (LAN) device to the front end controllers. This paper presents the current architecture, performance envelope, current installations, and planned extensions for requirements not met by the current architecture. C1 ARGONNE NATL LAB,ARGONNE,IL 60439. UNIV CALIF BERKELEY,LAWRENCE BERKELEY LAB,BERKELEY,CA 94720. SUPERCONDUCTING SUPER COLLIDER LAB,DALLAS,TX 75237. CONTINUOUS ELECTRON BEAM ACCELERATOR FACIL CTR,NEWPORT NEWS,VA 23606. DESY,W-2000 HAMBURG,GERMANY. TATE INTEGRATED SYST,BALTIMORE,MD. RP DALESIO, LR (reprint author), LOS ALAMOS NATL LAB,POB 1663,LOS ALAMOS,NM, USA. NR 13 TC 74 Z9 76 U1 0 U2 4 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0168-9002 J9 NUCL INSTRUM METH A JI Nucl. Instrum. Methods Phys. Res. Sect. A-Accel. Spectrom. Dect. Assoc. Equip. PD DEC 15 PY 1994 VL 352 IS 1-2 BP 179 EP 184 DI 10.1016/0168-9002(94)91493-1 PG 6 WC Instruments & Instrumentation; Nuclear Science & Technology; Physics, Nuclear; Physics, Particles & Fields SC Instruments & Instrumentation; Nuclear Science & Technology; Physics GA QA953 UT WOS:A1994QA95300048 ER PT J AU HOFF, LT SKELLY, JF AF HOFF, LT SKELLY, JF TI ACCELERATOR DEVICES AT PERSISTENT SOFTWARE OBJECTS SO NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH SECTION A-ACCELERATORS SPECTROMETERS DETECTORS AND ASSOCIATED EQUIPMENT LA English DT Article; Proceedings Paper CT 3rd International Conference on Accelerator and Large Experimental Physics Control Systems CY OCT 18-23, 1993 CL BERLIN, GERMANY SP HAHN MEITNER INST BERLIN GMBH, EPS IDG PHYS CONTROL SYST, EUROPEAN PHYS SOC, GERMAN PHYS SOC, ASSOC ASIAN PACIFIC PHYS SOC, IEEE, NUCL & PLASMA SCI SOC AB In the current ''standard model'' of accelerator control systems, the interface to accelerator equipment is implemented in a network component termed a front end computer. A front end computer system is being developed which provides access to underlying accelerator equipment via an abstraction termed an accelerator device object. Accelerator device objects support a standard set of operations which can be performed on them and contain all parameters necessary for controlling the underlying equipment. Accelerator device objects are realized as instances of C++ classes in software running in a real-time operating system, but exist independent of a particular task context and persist through system reset or power loss. This front end computer system is applied both to the development of a new control system for the RHIC project and also to the rejuvenation of an aged part of the AGS control system and its integration into the existing AGS Distributed Control System. RP HOFF, LT (reprint author), BROOKHAVEN NATL LAB,UPTON,NY 11973, USA. NR 12 TC 5 Z9 5 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 DEC 15 PY 1994 VL 352 IS 1-2 BP 185 EP 188 DI 10.1016/0168-9002(94)91494-X PG 4 WC Instruments & Instrumentation; Nuclear Science & Technology; Physics, Nuclear; Physics, Particles & Fields SC Instruments & Instrumentation; Nuclear Science & Technology; Physics GA QA953 UT WOS:A1994QA95300049 ER PT J AU GOODWIN, RW KUCERA, MJ SHEA, MF AF GOODWIN, RW KUCERA, MJ SHEA, MF TI USE OF SMALL STAND-ALONE INTERNET NODES AS A DISTRIBUTED CONTROL-SYSTEM SO NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH SECTION A-ACCELERATORS SPECTROMETERS DETECTORS AND ASSOCIATED EQUIPMENT LA English DT Article; Proceedings Paper CT 3rd International Conference on Accelerator and Large Experimental Physics Control Systems CY OCT 18-23, 1993 CL BERLIN, GERMANY SP HAHN MEITNER INST BERLIN GMBH, EPS IDG PHYS CONTROL SYST, EUROPEAN PHYS SOC, GERMAN PHYS SOC, ASSOC ASIAN PACIFIC PHYS SOC, IEEE, NUCL & PLASMA SCI SOC AB For several years, the standard model for accelerator control systems has been workstation consoles connected to VME local stations by a Local Area Network with analog and digital data being accessed via a field bus to custom I/O interface electronics. Commercially available hardware has now made it possible to implement a small stand-alone data acquisition station that combines the LAN connection, the computer, and the analog and digital I/O interface on a single board. This eliminates the complexity of a field bus and the associated proprietary I/O hardware. A minimum control system is one data acquisition station and a Macintosh or workstation console, both connected to the network; larger systems have more consoles and nodes. An implementation of this architecture is described along with performance and operational experience. RP GOODWIN, RW (reprint author), FERMILAB NATL ACCELERATOR LAB,POB 500,BATAVIA,IL 60510, USA. NR 2 TC 0 Z9 0 U1 0 U2 0 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0168-9002 J9 NUCL INSTRUM METH A JI Nucl. Instrum. Methods Phys. Res. Sect. A-Accel. Spectrom. Dect. Assoc. Equip. PD DEC 15 PY 1994 VL 352 IS 1-2 BP 189 EP 192 DI 10.1016/0168-9002(94)91495-8 PG 4 WC Instruments & Instrumentation; Nuclear Science & Technology; Physics, Nuclear; Physics, Particles & Fields SC Instruments & Instrumentation; Nuclear Science & Technology; Physics GA QA953 UT WOS:A1994QA95300050 ER PT J AU COULTER, KJ NAWROCKI, GJ AF COULTER, KJ NAWROCKI, GJ TI SURVEY OF HARDWARE SUPPORTED BY THE CONTROL-SYSTEM AT THE ADVANCED PHOTON SOURCE SO NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH SECTION A-ACCELERATORS SPECTROMETERS DETECTORS AND ASSOCIATED EQUIPMENT LA English DT Article; Proceedings Paper CT 3rd International Conference on Accelerator and Large Experimental Physics Control Systems CY OCT 18-23, 1993 CL BERLIN, GERMANY SP HAHN MEITNER INST BERLIN GMBH, EPS IDG PHYS CONTROL SYST, EUROPEAN PHYS SOC, GERMAN PHYS SOC, ASSOC ASIAN PACIFIC PHYS SOC, IEEE, NUCL & PLASMA SCI SOC AB The Experimental Physics and Industrial Control System (EPICS) has been under development at Los Alamos and Argonne National Laboratories for over six years. A wide variety of instrumentation is now supported. This presentation will give an overview of the types of hardware and subsystems which are currently supported and will discuss future plans for addressing additional hardware requirements at the APS. Supported systems to be discussed include: motion control, vacuum pump control and system monitoring, standard laboratory instrumentation, image processing, discrete binary and analog I/O, and standard temperature, pressure and flow monitoring. C1 ARGONNE NATL LAB,ADV PHOTON SOURCE,ARGONNE,IL 60439. NR 2 TC 1 Z9 1 U1 0 U2 0 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0168-9002 J9 NUCL INSTRUM METH A JI Nucl. Instrum. Methods Phys. Res. Sect. A-Accel. Spectrom. Dect. Assoc. Equip. PD DEC 15 PY 1994 VL 352 IS 1-2 BP 201 EP 203 DI 10.1016/0168-9002(94)91499-0 PG 3 WC Instruments & Instrumentation; Nuclear Science & Technology; Physics, Nuclear; Physics, Particles & Fields SC Instruments & Instrumentation; Nuclear Science & Technology; Physics GA QA953 UT WOS:A1994QA95300054 ER PT J AU STEIN, SJ AF STEIN, SJ TI ONE-WAY DATA TRANSFER FOR PLC TO VME STATUS REPORTING AT THE ADVANCED PHOTON SOURCE SO NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH SECTION A-ACCELERATORS SPECTROMETERS DETECTORS AND ASSOCIATED EQUIPMENT LA English DT Article; Proceedings Paper CT 3rd International Conference on Accelerator and Large Experimental Physics Control Systems CY OCT 18-23, 1993 CL BERLIN, GERMANY SP HAHN MEITNER INST BERLIN GMBH, EPS IDG PHYS CONTROL SYST, EUROPEAN PHYS SOC, GERMAN PHYS SOC, ASSOC ASIAN PACIFIC PHYS SOC, IEEE, NUCL & PLASMA SCI SOC AB The Personnel Safety System for the experimental beamlines at the Advanced Photon Source will use a large number of Alien Bradley Programmable Logic Controllers (PLC) to replace conventional relay logic. PLCs allow for the design of a very advanced safety system that can handle a large number of I/O points. Certain situations require monitoring of the safety system from various locations around the storage ring via the EPICS OPI (operator interface) consoles. This presentation covers the chosen method for transferring data from the Personnel Safety System into an EPICS database. Specifications on PLC ladder design, EPICS database design and hardware selection are also discussed. RP STEIN, SJ (reprint author), ARGONNE NATL LAB,DIV EXPTL FACIL,9700 S CASS AVE,ARGONNE,IL 60439, USA. NR 0 TC 0 Z9 0 U1 0 U2 1 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0168-9002 J9 NUCL INSTRUM METH A JI Nucl. Instrum. Methods Phys. Res. Sect. A-Accel. Spectrom. Dect. Assoc. Equip. PD DEC 15 PY 1994 VL 352 IS 1-2 BP 210 EP 212 DI 10.1016/0168-9002(94)91502-4 PG 3 WC Instruments & Instrumentation; Nuclear Science & Technology; Physics, Nuclear; Physics, Particles & Fields SC Instruments & Instrumentation; Nuclear Science & Technology; Physics GA QA953 UT WOS:A1994QA95300057 ER PT J AU HILL, JO AF HILL, JO TI EPICS COMMUNICATION LOSS MANAGEMENT SO NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH SECTION A-ACCELERATORS SPECTROMETERS DETECTORS AND ASSOCIATED EQUIPMENT LA English DT Article; Proceedings Paper CT 3rd International Conference on Accelerator and Large Experimental Physics Control Systems CY OCT 18-23, 1993 CL BERLIN, GERMANY SP HAHN MEITNER INST BERLIN GMBH, EPS IDG PHYS CONTROL SYST, EUROPEAN PHYS SOC, GERMAN PHYS SOC, ASSOC ASIAN PACIFIC PHYS SOC, IEEE, NUCL & PLASMA SCI SOC AB In a distributed control system there are multiple processors interconnected by a communications media such as a LAN. Plant I/O points are often divided between these processors according to the number of points that a processor can promptly service and according to processor locations which minimize field wiring. A robust distributed control system should properly respond to temporary loss of communication with any portion of the system. This temporary loss could be caused by hardware or software failures or it could be caused by reconfiguring or rebooting other portions of the system. For the Experimental Physics and Industrial Control System we have handled these temporary outages consistently and reliably. This capability makes it possible for distributed functions such as loop closure, sequencing, archiving, or operator consoles to take proper action at the beginning and end of the loss of communication with another part of the system. The control system continues to function in a degraded mode while some of its subsystems are not responding and resumes normal operation once a subsystem is restored. RP HILL, JO (reprint author), LOS ALAMOS NATL LAB,POB 1663,LOS ALAMOS,NM 87545, USA. NR 2 TC 2 Z9 2 U1 0 U2 2 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0168-9002 J9 NUCL INSTRUM METH A JI Nucl. Instrum. Methods Phys. Res. Sect. A-Accel. Spectrom. Dect. Assoc. Equip. PD DEC 15 PY 1994 VL 352 IS 1-2 BP 218 EP 220 DI 10.1016/0168-9002(94)91505-9 PG 3 WC Instruments & Instrumentation; Nuclear Science & Technology; Physics, Nuclear; Physics, Particles & Fields SC Instruments & Instrumentation; Nuclear Science & Technology; Physics GA QA953 UT WOS:A1994QA95300060 ER PT J AU HILL, JO AF HILL, JO TI A VXI-MESSAGE-BASED COMMUNICATIONS DRIVER AND RESOURCE MANAGER FOR EPICS SO NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH SECTION A-ACCELERATORS SPECTROMETERS DETECTORS AND ASSOCIATED EQUIPMENT LA English DT Article; Proceedings Paper CT 3rd International Conference on Accelerator and Large Experimental Physics Control Systems CY OCT 18-23, 1993 CL BERLIN, GERMANY SP HAHN MEITNER INST BERLIN GMBH, EPS IDG PHYS CONTROL SYST, EUROPEAN PHYS SOC, GERMAN PHYS SOC, ASSOC ASIAN PACIFIC PHYS SOC, IEEE, NUCL & PLASMA SCI SOC AB The VXI specification describes an open architecture instrumentation bus based on extensions of existing VME bus standards. The VXI system architecture provides for a central resource manager that identifies all VXI devices in the system, manages the system self-test and diagnostic sequence, configures the system's A24 and A32 address maps, configures the system's commander/servant hierarchies, allocates the system's interrupt request lines and initiates normal system operation. The VXI system architecture also provides for a standard set of communication protocols for use with a special class of message-based devices. A message-based communication library and resource manager were developed for use with the Experimental Physics and Industrial Control System (EPICS) in compliance with the VXI specification. The portability, performance and completeness of the author's implementation are discussed. RP HILL, JO (reprint author), LOS ALAMOS NATL LAB,POB 1663,LOS ALAMOS,NM 87545, USA. NR 4 TC 0 Z9 0 U1 0 U2 0 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0168-9002 J9 NUCL INSTRUM METH A JI Nucl. Instrum. Methods Phys. Res. Sect. A-Accel. Spectrom. Dect. Assoc. Equip. PD DEC 15 PY 1994 VL 352 IS 1-2 BP 221 EP 223 DI 10.1016/0168-9002(94)91506-7 PG 3 WC Instruments & Instrumentation; Nuclear Science & Technology; Physics, Nuclear; Physics, Particles & Fields SC Instruments & Instrumentation; Nuclear Science & Technology; Physics GA QA953 UT WOS:A1994QA95300061 ER PT J AU AHN, S BARTLETT, JF DENISENKO, N FUESS, S JONCKHEERE, A KRZYWDZINSKI, S PATERNO, L PROSPER, H RAJA, R FEATHERLY, J GIBBARD, B RASMUSSEN, L AF AHN, S BARTLETT, JF DENISENKO, N FUESS, S JONCKHEERE, A KRZYWDZINSKI, S PATERNO, L PROSPER, H RAJA, R FEATHERLY, J GIBBARD, B RASMUSSEN, L TI CONTROL AND MONITORING OF THE D0 DETECTOR SO NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH SECTION A-ACCELERATORS SPECTROMETERS DETECTORS AND ASSOCIATED EQUIPMENT LA English DT Article; Proceedings Paper CT 3rd International Conference on Accelerator and Large Experimental Physics Control Systems CY OCT 18-23, 1993 CL BERLIN, GERMANY SP HAHN MEITNER INST BERLIN GMBH, EPS IDG PHYS CONTROL SYST, EUROPEAN PHYS SOC, GERMAN PHYS SOC, ASSOC ASIAN PACIFIC PHYS SOC, IEEE, NUCL & PLASMA SCI SOC AB The D0 experiment at the Fermilab Tevatron Collider is currently studying proton-antiproton collisions at a center-of-mass energy of 1.8 TeV. The data-acquisition system for the experiment was designed with two independent pathways for communication between the front-end computers, which interface with the detector electronics, and the host-level computers, where the event data is logged and where the experiment is monitored and controlled. The event data path employs multiple, high-bandwidth, unidirectional busses while the control path, which uses standard local area network components, handles all control, configuration setting, alarm, and monitoring communications. This paper discusses the software components associated with the control communication path, with emphasis upon the design philosophy, user interface, database, and networking issues. C1 FERMILAB NATL ACCELERATOR LAB,BATAVIA,IL 60510. BROOKHAVEN NATL LAB,DEPT PHYS,UPTON,NY 11973. SUNY STONY BROOK,DEPT PHYS,STONY BROOK,NY 11794. NR 6 TC 0 Z9 0 U1 0 U2 0 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0168-9002 J9 NUCL INSTRUM METH A JI Nucl. Instrum. Methods Phys. Res. Sect. A-Accel. Spectrom. Dect. Assoc. Equip. PD DEC 15 PY 1994 VL 352 IS 1-2 BP 250 EP 253 DI 10.1016/0168-9002(94)91514-8 PG 4 WC Instruments & Instrumentation; Nuclear Science & Technology; Physics, Nuclear; Physics, Particles & Fields SC Instruments & Instrumentation; Nuclear Science & Technology; Physics GA QA953 UT WOS:A1994QA95300069 ER PT J AU BJORKLUND, E AF BJORKLUND, E TI VIRTUAL DATA SO NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH SECTION A-ACCELERATORS SPECTROMETERS DETECTORS AND ASSOCIATED EQUIPMENT LA English DT Article; Proceedings Paper CT 3rd International Conference on Accelerator and Large Experimental Physics Control Systems CY OCT 18-23, 1993 CL BERLIN, GERMANY SP HAHN MEITNER INST BERLIN GMBH, EPS IDG PHYS CONTROL SYST, EUROPEAN PHYS SOC, GERMAN PHYS SOC, ASSOC ASIAN PACIFIC PHYS SOC, IEEE, NUCL & PLASMA SCI SOC AB In the 1970s, when computers were memory limited, operating system designers created the concept of ''virtual memory'', which gave users the ability to address more memory than physically existed. In the 1990s, many large control systems have the potential of becoming data limited. We propose that many of the principles behind virtual memory systems (working sets, locality, caching and clustering) can also be applied to data-limited systems, creating, in effect, ''virtual data systems''. At the Los Alamos National Laboratory's Clinton P. Anderson Meson Physics Facility (LAMPF), we have applied these principles to a moderately sized (10000 data points) data acquisition and control system. To test the principles, we measured the system's performance during tune-up, production, and maintenance periods. In this paper, we present a general discussion of the principles of a virtual data system along with some discussion of our own implementation and the results of our performance measurements. RP BJORKLUND, E (reprint author), LOS ALAMOS NATL LAB,POB 1663,LOS ALAMOS,NM 87545, USA. NR 6 TC 0 Z9 0 U1 0 U2 0 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0168-9002 J9 NUCL INSTRUM METH A JI Nucl. Instrum. Methods Phys. Res. Sect. A-Accel. Spectrom. Dect. Assoc. Equip. PD DEC 15 PY 1994 VL 352 IS 1-2 BP 293 EP 295 DI 10.1016/0168-9002(94)91526-1 PG 3 WC Instruments & Instrumentation; Nuclear Science & Technology; Physics, Nuclear; Physics, Particles & Fields SC Instruments & Instrumentation; Nuclear Science & Technology; Physics GA QA953 UT WOS:A1994QA95300081 ER PT J AU MEAD, WC BROWN, SK JONES, RD BOWLING, PS BARNES, CW AF MEAD, WC BROWN, SK JONES, RD BOWLING, PS BARNES, CW TI ADAPTIVE OPTIMIZATION AND CONTROL USING NEURAL NETWORKS SO NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH SECTION A-ACCELERATORS SPECTROMETERS DETECTORS AND ASSOCIATED EQUIPMENT LA English DT Article; Proceedings Paper CT 3rd International Conference on Accelerator and Large Experimental Physics Control Systems CY OCT 18-23, 1993 CL BERLIN, GERMANY SP HAHN MEITNER INST BERLIN GMBH, EPS IDG PHYS CONTROL SYST, EUROPEAN PHYS SOC, GERMAN PHYS SOC, ASSOC ASIAN PACIFIC PHYS SOC, IEEE, NUCL & PLASMA SCI SOC AB Recent work has demonstrated the ability of neural-network-based controllers to optimize and control machines with complex, non-linear, relatively unknown control spaces. We present a brief overview of neural networks via a taxonomy illustrating some capabilities of different kinds of neutral networks. We present some successful control examples, particularly the optimization and control of a small-angle negative ion source. RP MEAD, WC (reprint author), LOS ALAMOS NATL LAB,POB 1663,LOS ALAMOS,NM, USA. NR 17 TC 4 Z9 4 U1 0 U2 0 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0168-9002 J9 NUCL INSTRUM METH A JI Nucl. Instrum. Methods Phys. Res. Sect. A-Accel. Spectrom. Dect. Assoc. Equip. PD DEC 15 PY 1994 VL 352 IS 1-2 BP 309 EP 315 DI 10.1016/0168-9002(94)91530-X PG 7 WC Instruments & Instrumentation; Nuclear Science & Technology; Physics, Nuclear; Physics, Particles & Fields SC Instruments & Instrumentation; Nuclear Science & Technology; Physics GA QA953 UT WOS:A1994QA95300085 ER PT J AU PAXSON, V AF PAXSON, V TI GLISH - A SOFTWARE BUS FOR HIGH-LEVEL CONTROL SO NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH SECTION A-ACCELERATORS SPECTROMETERS DETECTORS AND ASSOCIATED EQUIPMENT LA English DT Article; Proceedings Paper CT 3rd International Conference on Accelerator and Large Experimental Physics Control Systems CY OCT 18-23, 1993 CL BERLIN, GERMANY SP HAHN MEITNER INST BERLIN GMBH, EPS IDG PHYS CONTROL SYST, EUROPEAN PHYS SOC, GERMAN PHYS SOC, ASSOC ASIAN PACIFIC PHYS SOC, IEEE, NUCL & PLASMA SCI SOC AB Glish is a software system for building high-level control applications out of modular, event-oriented programs. Glish provides these applications with a high degree of flexibility, so they can adapt quickly to changing requirements. We describe the strengths of the ''software bus'' approach, how Glish can direct and modify interprocess communication within a distributed application, and how the system is currently used for orbit-correction at the Advanced Light Source at LBL. RP PAXSON, V (reprint author), UNIV CALIF BERKELEY,LAWRENCE BERKELEY LAB,1 CYCLOTRON RD,BERKELEY,CA 94720, USA. NR 5 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 DEC 15 PY 1994 VL 352 IS 1-2 BP 316 EP 321 DI 10.1016/0168-9002(94)91531-8 PG 6 WC Instruments & Instrumentation; Nuclear Science & Technology; Physics, Nuclear; Physics, Particles & Fields SC Instruments & Instrumentation; Nuclear Science & Technology; Physics GA QA953 UT WOS:A1994QA95300086 ER PT J AU PEGGS, S SALTMARSH, C SATOGATA, T FRYER, M AF PEGGS, S SALTMARSH, C SATOGATA, T FRYER, M TI HIGH-LEVEL CONTROLS AT RHIC SO NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH SECTION A-ACCELERATORS SPECTROMETERS DETECTORS AND ASSOCIATED EQUIPMENT LA English DT Article; Proceedings Paper CT 3rd International Conference on Accelerator and Large Experimental Physics Control Systems CY OCT 18-23, 1993 CL BERLIN, GERMANY SP HAHN MEITNER INST BERLIN GMBH, EPS IDG PHYS CONTROL SYST, EUROPEAN PHYS SOC, GERMAN PHYS SOC, ASSOC ASIAN PACIFIC PHYS SOC, IEEE, NUCL & PLASMA SCI SOC AB We report on the software tools and techniques in development to ensure that the commissioning and operations teams for RHIC have access to high level analysis, diagnosis, modelling and control functions early in the start up of the machine. The first tests will be for the sextant test in mid-1995. C1 UNIV CALIF BERKELEY,LAWRENCE BERKELEY LAB,BERKELEY,CA 94720. RP PEGGS, S (reprint author), BROOKHAVEN NATL LAB,UPTON,NY 11973, USA. NR 3 TC 0 Z9 0 U1 0 U2 0 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0168-9002 J9 NUCL INSTRUM METH A JI Nucl. Instrum. Methods Phys. Res. Sect. A-Accel. Spectrom. Dect. Assoc. Equip. PD DEC 15 PY 1994 VL 352 IS 1-2 BP 322 EP 324 DI 10.1016/0168-9002(94)91532-6 PG 3 WC Instruments & Instrumentation; Nuclear Science & Technology; Physics, Nuclear; Physics, Particles & Fields SC Instruments & Instrumentation; Nuclear Science & Technology; Physics GA QA953 UT WOS:A1994QA95300087 ER PT J AU FRIEDMAN, A BOZOKI, E AF FRIEDMAN, A BOZOKI, E TI A DIGITAL FEEDBACK-SYSTEM FOR TRANSVERSE ORBIT STABILIZATION IN THE NSLS RINGS SO NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH SECTION A-ACCELERATORS SPECTROMETERS DETECTORS AND ASSOCIATED EQUIPMENT LA English DT Article; Proceedings Paper CT 3rd International Conference on Accelerator and Large Experimental Physics Control Systems CY OCT 18-23, 1993 CL BERLIN, GERMANY SP HAHN MEITNER INST BERLIN GMBH, EPS IDG PHYS CONTROL SYST, EUROPEAN PHYS SOC, GERMAN PHYS SOC, ASSOC ASIAN PACIFIC PHYS SOC, IEEE, NUCL & PLASMA SCI SOC AB We are reporting on the design and preliminary results of a prototype digital feedback system for the storage rings at the NSLS. The system will use a nonlinear eigenvector decomposition algorithm. It will have a wide dynamic range and will be able to correct noise in the orbit over a bandwidth in excess of 60 Hz. A Motorola-162 CPU board is used to sample the PUE's at a minimum rate of 200 Hz and an HP-742rt board is used to read the sampled signals and to generate a correction signal for the orbit correctors. RP FRIEDMAN, A (reprint author), BROOKHAVEN NATL LAB,NATL SYNCHROTRON LIGHT SOURCE DEPT,UPTON,NY 11973, USA. NR 8 TC 0 Z9 0 U1 0 U2 0 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0168-9002 J9 NUCL INSTRUM METH A JI Nucl. Instrum. Methods Phys. Res. Sect. A-Accel. Spectrom. Dect. Assoc. Equip. PD DEC 15 PY 1994 VL 352 IS 1-2 BP 339 EP 341 DI 10.1016/0168-9002(94)91537-7 PG 3 WC Instruments & Instrumentation; Nuclear Science & Technology; Physics, Nuclear; Physics, Particles & Fields SC Instruments & Instrumentation; Nuclear Science & Technology; Physics GA QA953 UT WOS:A1994QA95300092 ER PT J AU HENDRICKS, B AF HENDRICKS, B TI PROGRAM RECORDING OF USER ACTIONS AND ITS USE IN THE FERMILAB ACCELERATOR CONTROL-SYSTEM SO NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH SECTION A-ACCELERATORS SPECTROMETERS DETECTORS AND ASSOCIATED EQUIPMENT LA English DT Article; Proceedings Paper CT 3rd International Conference on Accelerator and Large Experimental Physics Control Systems CY OCT 18-23, 1993 CL BERLIN, GERMANY SP HAHN MEITNER INST BERLIN GMBH, EPS IDG PHYS CONTROL SYST, EUROPEAN PHYS SOC, GERMAN PHYS SOC, ASSOC ASIAN PACIFIC PHYS SOC, IEEE, NUCL & PLASMA SCI SOC AB This paper describes the implementation of, and experience with, recording and playback of user actions during execution of application programs. All operator console applications have access to this facility as part of their runtime environment. It is used for program macros, safe operator training, and application tutorials. Various difficulties and capabilities inherent in this type of facility are also discussed. RP HENDRICKS, B (reprint author), FERMILAB NATL ACCELERATOR LAB,POB 500,BATAVIA,IL 60510, USA. NR 1 TC 0 Z9 0 U1 0 U2 0 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0168-9002 J9 NUCL INSTRUM METH A JI Nucl. Instrum. Methods Phys. Res. Sect. A-Accel. Spectrom. Dect. Assoc. Equip. PD DEC 15 PY 1994 VL 352 IS 1-2 BP 368 EP 369 DI 10.1016/0168-9002(94)91545-8 PG 2 WC Instruments & Instrumentation; Nuclear Science & Technology; Physics, Nuclear; Physics, Particles & Fields SC Instruments & Instrumentation; Nuclear Science & Technology; Physics GA QA953 UT WOS:A1994QA95300100 ER PT J AU NISHIMURA, H AF NISHIMURA, H TI OBJECT-ORIENTED SOFTWARE CONSTRUCTION AT ALS SO NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH SECTION A-ACCELERATORS SPECTROMETERS DETECTORS AND ASSOCIATED EQUIPMENT LA English DT Article; Proceedings Paper CT 3rd International Conference on Accelerator and Large Experimental Physics Control Systems CY OCT 18-23, 1993 CL BERLIN, GERMANY SP HAHN MEITNER INST BERLIN GMBH, EPS IDG PHYS CONTROL SYST, EUROPEAN PHYS SOC, GERMAN PHYS SOC, ASSOC ASIAN PACIFIC PHYS SOC, IEEE, NUCL & PLASMA SCI SOC AB C++ class libraries have been developed and used for accelerator modeling and machine control at the Advanced Light Source. A class library for accelerator modeling is portable and supports multiple model instances dynamically at run time. A class library for machine control covers fields from virtual devices to simulation studies. RP NISHIMURA, H (reprint author), UNIV CALIF BERKELEY,LAWRENCE BERKELEY LAB,BERKELEY,CA 94720, USA. NR 22 TC 2 Z9 2 U1 0 U2 0 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0168-9002 J9 NUCL INSTRUM METH A JI Nucl. Instrum. Methods Phys. Res. Sect. A-Accel. Spectrom. Dect. Assoc. Equip. PD DEC 15 PY 1994 VL 352 IS 1-2 BP 379 EP 382 DI 10.1016/0168-9002(94)91548-2 PG 4 WC Instruments & Instrumentation; Nuclear Science & Technology; Physics, Nuclear; Physics, Particles & Fields SC Instruments & Instrumentation; Nuclear Science & Technology; Physics GA QA953 UT WOS:A1994QA95300103 ER PT J AU LUBLINSKY, B AF LUBLINSKY, B TI SHELL SOFTWARE FOR SMART SUBSYSTEMS WITH FRONT-END CAPABILITIES SO NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH SECTION A-ACCELERATORS SPECTROMETERS DETECTORS AND ASSOCIATED EQUIPMENT LA English DT Article; Proceedings Paper CT 3rd International Conference on Accelerator and Large Experimental Physics Control Systems CY OCT 18-23, 1993 CL BERLIN, GERMANY SP HAHN MEITNER INST BERLIN GMBH, EPS IDG PHYS CONTROL SYST, EUROPEAN PHYS SOC, GERMAN PHYS SOC, ASSOC ASIAN PACIFIC PHYS SOC, IEEE, NUCL & PLASMA SCI SOC AB During the last few years there has been a trend towards incorporating smart subsystems into the ACNET control system. These smart subsystems are capable of doing direct I/O and communicating with the rest of the control system by means of standardized networking protocols. Creating custom software for each type of smart subsystems is not cost effective. Consequently, it was decided to create the standardized software shell for smart subsystems. The shell consists of an Object-Oriented kernel, OOC++, and standard ACNET communication support. OOC++ is implemented similarly to C++ late binding and memory management techniques and is based upon OIDs (object identificators), defining each particular object. ACNET communication support is built upon OOC++. The shell software is presently available on 680x0 and 80386 processors under MTOS and 680x0 processors under VxWorks. This paper gives the shell's description along with examples of smart subsystems utilizing the shell. It also shows that the described shell software allows significant reduction in system creation and debugging time and increased flexibility and robustness of the produced systems. RP LUBLINSKY, B (reprint author), FERMILAB NATL ACCELERATOR LAB,POB 500,BATAVIA,IL 60510, USA. NR 3 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 DEC 15 PY 1994 VL 352 IS 1-2 BP 403 EP 406 DI 10.1016/0168-9002(94)91554-7 PG 4 WC Instruments & Instrumentation; Nuclear Science & Technology; Physics, Nuclear; Physics, Particles & Fields SC Instruments & Instrumentation; Nuclear Science & Technology; Physics GA QA953 UT WOS:A1994QA95300109 ER PT J AU KOZUBAL, AJ KERSTIENS, DM WRIGHT, RM AF KOZUBAL, AJ KERSTIENS, DM WRIGHT, RM TI EXPERIENCE WITH THE STATE NOTATION LANGUAGE AND RUN-TIME SEQUENCER SO NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH SECTION A-ACCELERATORS SPECTROMETERS DETECTORS AND ASSOCIATED EQUIPMENT LA English DT Article; Proceedings Paper CT 3rd International Conference on Accelerator and Large Experimental Physics Control Systems CY OCT 18-23, 1993 CL BERLIN, GERMANY SP HAHN MEITNER INST BERLIN GMBH, EPS IDG PHYS CONTROL SYST, EUROPEAN PHYS SOC, GERMAN PHYS SOC, ASSOC ASIAN PACIFIC PHYS SOC, IEEE, NUCL & PLASMA SCI SOC AB The State Notation Language (SNL) has gained wide acceptance as a control system development tool. The SNL uses a subset of C with additional control statements that are based on the state transition diagram paradigm. In conjunction with a run-time sequencer, the SNL offers programming simplicity without significant performance penalty. As one of the major tools in the Experimental Physics and Industrial Control System (EPICS), the SNL has been successfully used on several control systems in a wide variety of applications, such as machine sequencing operation of beam diagnostics and facilitating complex operator interface functions. This paper presents the results of a survey of the various users of the SNL. The intent is to judge how well the SNL has met its original objectives and to determine future improvements. Such improvements will include implementing a graphical sequencer builder and providing a comprehensive graphical debugging tool. RP KOZUBAL, AJ (reprint author), LOS ALAMOS NATL LAB,LOS ALAMOS,NM 87545, USA. NR 8 TC 2 Z9 2 U1 0 U2 0 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0168-9002 J9 NUCL INSTRUM METH A JI Nucl. Instrum. Methods Phys. Res. Sect. A-Accel. Spectrom. Dect. Assoc. Equip. PD DEC 15 PY 1994 VL 352 IS 1-2 BP 411 EP 414 DI 10.1016/0168-9002(94)91556-3 PG 4 WC Instruments & Instrumentation; Nuclear Science & Technology; Physics, Nuclear; Physics, Particles & Fields SC Instruments & Instrumentation; Nuclear Science & Technology; Physics GA QA953 UT WOS:A1994QA95300111 ER PT J AU LUCAS, P BOHN, HU DUC, CN MAZZA, C POTEPAN, F AF LUCAS, P BOHN, HU DUC, CN MAZZA, C POTEPAN, F TI SUMMARY OF SESSION WE-K PANEL DISCUSSION ON THE TOPIC - SHOULD WE BUY NOT BUILD A CONTROL-SYSTEM SO NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH SECTION A-ACCELERATORS SPECTROMETERS DETECTORS AND ASSOCIATED EQUIPMENT LA English DT Editorial Material C1 NATL INSTRUMENTS,AUSTIN,TX. ESOC DARMSTADT,DARMSTADT,GERMANY. SYNCHROTRONE TRIESTE,TRIESTE,ITALY. RP LUCAS, P (reprint author), FERMILAB NATL ACCELERATOR LAB,POB 500,BATAVIA,IL 60510, USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0168-9002 J9 NUCL INSTRUM METH A JI Nucl. Instrum. Methods Phys. Res. Sect. A-Accel. Spectrom. Dect. Assoc. Equip. PD DEC 15 PY 1994 VL 352 IS 1-2 BP 484 EP 485 PG 2 WC Instruments & Instrumentation; Nuclear Science & Technology; Physics, Nuclear; Physics, Particles & Fields SC Instruments & Instrumentation; Nuclear Science & Technology; Physics GA QA953 UT WOS:A1994QA95300131 ER PT J AU KNOTT, M GURD, D LEWIS, S THUOT, M AF KNOTT, M GURD, D LEWIS, S THUOT, M TI EPICS - A CONTROL-SYSTEM SOFTWARE CO-DEVELOPMENT SUCCESS STORY SO NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH SECTION A-ACCELERATORS SPECTROMETERS DETECTORS AND ASSOCIATED EQUIPMENT LA English DT Article; Proceedings Paper CT 3rd International Conference on Accelerator and Large Experimental Physics Control Systems CY OCT 18-23, 1993 CL BERLIN, GERMANY SP HAHN MEITNER INST BERLIN GMBH, EPS IDG PHYS CONTROL SYST, EUROPEAN PHYS SOC, GERMAN PHYS SOC, ASSOC ASIAN PACIFIC PHYS SOC, IEEE, NUCL & PLASMA SCI SOC C1 SUPERCONDUCTING SUPER COLLIDER LAB,DALLAS,TX 75237. UNIV CALIF BERKELEY,LAWRENCE BERKELEY LAB,BERKELEY,CA. LOS ALAMOS NATL LAB,LOS ALAMOS,NM. RP KNOTT, M (reprint author), ARGONNE NATL LAB,ADV PHOTON SOURCE,BLDG 362,9700 S CASS AVE,ARGONNE,IL 60439, USA. NR 15 TC 2 Z9 3 U1 2 U2 2 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0168-9002 J9 NUCL INSTRUM METH A JI Nucl. Instrum. Methods Phys. Res. Sect. A-Accel. Spectrom. Dect. Assoc. Equip. PD DEC 15 PY 1994 VL 352 IS 1-2 BP 486 EP 491 DI 10.1016/0168-9002(94)91577-6 PG 6 WC Instruments & Instrumentation; Nuclear Science & Technology; Physics, Nuclear; Physics, Particles & Fields SC Instruments & Instrumentation; Nuclear Science & Technology; Physics GA QA953 UT WOS:A1994QA95300132 ER PT J AU SCHALLER, SC AF SCHALLER, SC TI A LAMPF CONTROLS RETROSPECTIVE - THE GOOD, THE BAD, AND IT SEEMED LIKE A GOOD IDEA AT THE TIME SO NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH SECTION A-ACCELERATORS SPECTROMETERS DETECTORS AND ASSOCIATED EQUIPMENT LA English DT Article; Proceedings Paper CT 3rd International Conference on Accelerator and Large Experimental Physics Control Systems CY OCT 18-23, 1993 CL BERLIN, GERMANY SP HAHN MEITNER INST BERLIN GMBH, EPS IDG PHYS CONTROL SYST, EUROPEAN PHYS SOC, GERMAN PHYS SOC, ASSOC ASIAN PACIFIC PHYS SOC, IEEE, NUCL & PLASMA SCI SOC AB LAMPF (Los Alamos Meson Physics Facility) was the first large particle accelerator to require the use of a computerized control system as part of its design. Over the past 25 years, the LAMPF control system has evolved from a single mini-computer system using home-built data acquisition hardware to a complex network of VAX and micro-VAX computers using CAMAC and other data acquisition protocols. On the occasion of LAMPF's possible closing, this paper provides a look back at how the LAMPF control system got to where it is today. After a brief historical introduction, we will discuss aspects of control system design and implementation including, the impact of technology on decision making and topics from the LAMPF operational experience. RP SCHALLER, SC (reprint author), LOS ALAMOS NATL LAB,POB 1663,LOS ALAMOS,NM 87545, USA. NR 26 TC 2 Z9 2 U1 0 U2 0 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0168-9002 J9 NUCL INSTRUM METH A JI Nucl. Instrum. Methods Phys. Res. Sect. A-Accel. Spectrom. Dect. Assoc. Equip. PD DEC 15 PY 1994 VL 352 IS 1-2 BP 516 EP 520 DI 10.1016/0168-9002(94)91581-4 PG 5 WC Instruments & Instrumentation; Nuclear Science & Technology; Physics, Nuclear; Physics, Particles & Fields SC Instruments & Instrumentation; Nuclear Science & Technology; Physics GA QA953 UT WOS:A1994QA95300136 ER PT J AU ELLIOTT, SR BEIERSDORFER, P LIBBY, SB OSTERHELD, AL PHILLIPS, T AF ELLIOTT, SR BEIERSDORFER, P LIBBY, SB OSTERHELD, AL PHILLIPS, T TI LINE OVERLAP MEASUREMENT FOR THE PHOTOPUMPING OF X-RAY LASING TRANSITIONS BETWEEN N=3 AND N=2 AUTOIONIZING STATES OF LITHIUM-LIKE AL SO OPTICS COMMUNICATIONS LA English DT Article ID DIELECTRONIC SATELLITE SPECTRA; NICKEL-LIKE IONS; HE-LIKE AB We performed a detailed measurement of the K beta spectrum of He-like Al11+, including the dielectronic satellite spectrum excited by the KLM resonances, and comparisons with theoretical predictions from multi-configuration Dirac-Fock calculations are made. We investigated the possibility of a line overlap between the (1s(2)2s) (J=1/2-)(1s2s3p)(J=3/2) transition in Li-like Al10+ and the (2s(2)2p(6))(J=0)-(2s(2)2p(1/2)(5)3s)(J=1) transition in Ne-Like Rb27+, situated near 1826 eV, to examine their suitability for use in a photopumped X-ray laser scheme. In this scheme with lasing at 46 Angstrom, the Rb27+ line pumps the Al10+ upper lasing level. The measured difference in the line energies is 0.7 +/- 0.1 eV or 380 ppm. RP ELLIOTT, SR (reprint author), LAWRENCE LIVERMORE NATL LAB,LIVERMORE,CA 94550, USA. NR 21 TC 3 Z9 3 U1 2 U2 2 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0030-4018 J9 OPT COMMUN JI Opt. Commun. PD DEC 15 PY 1994 VL 113 IS 1-3 BP 204 EP 212 DI 10.1016/0030-4018(94)90608-4 PG 9 WC Optics SC Optics GA QA755 UT WOS:A1994QA75500026 ER PT J AU PERRY, MD DITMIRE, T STUART, BC AF PERRY, MD DITMIRE, T STUART, BC TI SELF-PHASE MODULATION IN CHIRPED-PULSE AMPLIFICATION SO OPTICS LETTERS LA English DT Article ID OPTICAL PULSES; COMPENSATION; COMPRESSION; DISPERSION; EXPANSION; LASER AB The effect of self-phase modulation in chirped-pulse amplification is investigated. A numerical model is used to predict the effects of phase modulation on pulse recompression, and experimental results are presented that agree well with the calculations. We show that even moderate self-phase modulation can significantly distort the recompressed pulse after amplification, thereby reducing the peak power and degrading the pulse contrast. RP PERRY, MD (reprint author), LAWRENCE LIVERMORE NATL LAB,LASER PROGRAM,POB 808,L-493,LIVERMORE,CA 94550, USA. RI Stuart, Brent/K-4988-2015 NR 14 TC 92 Z9 98 U1 5 U2 17 PU OPTICAL SOC AMER PI WASHINGTON PA 2010 MASSACHUSETTS AVE NW, WASHINGTON, DC 20036 SN 0146-9592 J9 OPT LETT JI Opt. Lett. PD DEC 15 PY 1994 VL 19 IS 24 BP 2149 EP 2151 DI 10.1364/OL.19.002149 PG 3 WC Optics SC Optics GA QA175 UT WOS:A1994QA17500035 PM 19855769 ER PT J AU DELONG, KW FITTINGHOFF, DN TREBINO, R KOHLER, B WILSON, K AF DELONG, KW FITTINGHOFF, DN TREBINO, R KOHLER, B WILSON, K TI PULSE RETRIEVAL IN FREQUENCY-RESOLVED OPTICAL GATING BASED ON THE METHOD OF GENERALIZED PROJECTIONS SO OPTICS LETTERS LA English DT Article ID PHASE RETRIEVAL; INTENSITY AB We use the algorithmic method of generalized projections (GP's) to retrieve the intensity and phase of an ultrashort laser pulse from the experimental trace in frequency-resolved optical gating (FROG). Using simulations, we show that the use of GP's improves significantly the convergence properties of the algorithm over the basic FROG algorithm. In experimental measurements, the OF-based algorithm achieves significantly lower errors than previous algorithms. The use of GP's also permits the inclusion of an arbitrary material response function in the FROG problem. C1 UNIV CALIF SAN DIEGO,DEPT CHEM,LA JOLLA,CA 92093. RP DELONG, KW (reprint author), SANDIA NATL LABS,MS 9057,LIVERMORE,CA 94551, USA. RI Kohler, Bern/A-1728-2011 OI Kohler, Bern/0000-0001-5353-1655 NR 14 TC 96 Z9 100 U1 4 U2 18 PU OPTICAL SOC AMER PI WASHINGTON PA 2010 MASSACHUSETTS AVE NW, WASHINGTON, DC 20036 SN 0146-9592 J9 OPT LETT JI Opt. Lett. PD DEC 15 PY 1994 VL 19 IS 24 BP 2152 EP 2154 DI 10.1364/OL.19.002152 PG 3 WC Optics SC Optics GA QA175 UT WOS:A1994QA17500036 PM 19855770 ER PT J AU CHEN, YL CHAN, HM HARMER, MP TODT, VR SENGUPTA, S SHI, D AF CHEN, YL CHAN, HM HARMER, MP TODT, VR SENGUPTA, S SHI, D TI A NEW METHOD FOR NET-SHAPE FORMING OF LARGE, SINGLE-DOMAIN YBA2CU3O6+X SO PHYSICA C LA English DT Article ID CRITICAL CURRENT-DENSITY; TEXTURED YBA2CU3O7-DELTA; GRAIN-BOUNDARIES; WEAK-LINK; MELT; GROWTH; SUPERCONDUCTORS; MECHANISM AB A new process has been developed for the net-shape fabrication of bulk, single-domain YBa2Cu3O6+x (123) specimens. To date, transport critical currents in excess of 10 000 A cm-2 have been obtained. This process, designated the seeded preform (SPF) technique, involves the permeation of peritectic liquid through a preform of pressed Y2BaCuO5 (211) powder. The use of a single-crystal seed of Nd1+xBa2-xCu3O(y), ensures that only a single 123 domain is nucleated during the subsequent transformation: liquid + 211 --> 123. The SPF process enjoys several important advantages over the melt-texturing techniques which are currently available. In particular, it offers the potential of net-shape forming of bulk 123 samples with complex geometries, and circumvents problems such as sagging, and substrate reaction. Also unique to the SPF process is that it produces large, single domain 123, with essentially no encapsulated liquid phase. Finally, relative to conventional melt-texturing, there is a refinement of the size of the 211 inclusions in the final microstructure, and the particles are more uniformly distributed. C1 LEHIGH UNIV,DEPT MAT SCI & ENGN,BETHLEHEM,PA 18015. LEHIGH UNIV,MAT RES CTR,BETHLEHEM,PA 18015. ARGONNE NATL LAB,ARGONNE,IL 60439. UNIV CINCINNATI,DEPT MAT SCI & ENGN,CINCINNATI,OH 45221. NR 20 TC 47 Z9 51 U1 0 U2 5 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0921-4534 J9 PHYSICA C JI Physica C PD DEC 15 PY 1994 VL 234 IS 3-4 BP 232 EP 236 DI 10.1016/0921-4534(94)90568-1 PG 5 WC Physics, Applied SC Physics GA PY378 UT WOS:A1994PY37800005 ER PT J AU SCHULTZ, AJ WANG, HH WILLIAMS, JM FINGER, LW HAZEN, RM ROVIRA, C WHANGBO, MH AF SCHULTZ, AJ WANG, HH WILLIAMS, JM FINGER, LW HAZEN, RM ROVIRA, C WHANGBO, MH TI X-RAY-DIFFRACTION AND ELECTRONIC BAND-STRUCTURE STUDY OF THE ORGANIC SUPERCONDUCTOR-KAPPA-(ET)2CU[N(CN)2]CL AT PRESSURES UP TO 28 KBAR SO PHYSICA C LA English DT Article ID SUPERCONDUCTOR; CRYSTAL; KAPPA-(ET)2CUCL; SALTS AB The previously observed pressure-induced amorphization transition at 11 kbar [A.J. Schultz, U. Geiser, H.H. Wang, J.M. Williams, L.W. Finger and B.M. Hazen, Physica C 208 (1993) 277] was avoided and single-crystal X-ray data up to 28 kbar were obtained by replacing mineral oil with a hydrostatic alcohol mixture as the pressure medium in a diamond anvil cell. The linear compressibilities of the crystallographic axes are remarkably isotropic given the two-dimensional nature of the structure. A full structure determination was performed at room temperature and 28 kbar with the use of X-ray data. It is noteworthy that, a novel structure feature, short interlayer H...H contacts through a hole in the anion layer, may account for the isotropic compressibilities. Electronic band structures calculated for the crystal structures of kappa-(ET)2Cu[N(CN)2]Cl at 1 bar, 3 kbar and 28 kbar show that this salt is a two-dimensional metal, and that the density of states at the Fermi level decreases gradually with increasing pressure. C1 CARNEGIE INST WASHINGTON,GEOPHYS LAB,WASHINGTON,DC 20015. ARGONNE NATL LAB,DIV CHEM & MAT SCI,ARGONNE,IL 60439. CARNEGIE INST WASHINGTON,CTR HIGH PRESSURE RES,WASHINGTON,DC 20015. N CAROLINA STATE UNIV,DEPT CHEM,RALEIGH,NC 27695. RP SCHULTZ, AJ (reprint author), ARGONNE NATL LAB,DIV INTENSE PULSED NEUTRON SOURCE,ARGONNE,IL 60439, USA. RI Rovira, Carme/K-5195-2014 OI Rovira, Carme/0000-0003-1477-5010 NR 14 TC 16 Z9 16 U1 0 U2 0 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0921-4534 J9 PHYSICA C JI Physica C PD DEC 15 PY 1994 VL 234 IS 3-4 BP 300 EP 306 DI 10.1016/0921-4534(94)90577-0 PG 7 WC Physics, Applied SC Physics GA PY378 UT WOS:A1994PY37800014 ER PT J AU KRISHNARAJ, P LELOVIC, M EROR, NG BALACHANDRAN, U AF KRISHNARAJ, P LELOVIC, M EROR, NG BALACHANDRAN, U TI SYNTHESIS AND OXYGEN STOICHIOMETRY OF BI2SR2CACU2O8+X SO PHYSICA C LA English DT Article ID NONSTOICHIOMETRY; TC; LA2CUO4+DELTA; YBA2CU3O7-X; PRESSURE AB Bi2Sr2CaCu2O8+x (2212) was synthesized from freeze-dried precursors. The oxygen content of 2212 was determined as a function of temperature and oxygen partial pressure and the variation of T(c) with oxygen content was determined. It was found that 2212 without excess oxygen (x=0) is superconducting. This points to the role of the (Bi-O)infinity layers as a source for holes in 2212. It was also found that samples of 2212 with the same oxygen content had different T(c)'s depending on the thermal history. This difference in T(c) is thought to arise from oxygen occupying different sites in the lattice while maintaining the same total oxygen content. C1 UNIV PITTSBURGH,DEPT MAT SCI & ENGN,PITTSBURGH,PA 15261. ARGONNE NATL LAB,DIV ENERGY TECHNOL,ARGONNE,IL 60439. NR 20 TC 15 Z9 15 U1 0 U2 2 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0921-4534 J9 PHYSICA C JI Physica C PD DEC 15 PY 1994 VL 234 IS 3-4 BP 318 EP 322 DI 10.1016/0921-4534(94)90580-0 PG 5 WC Physics, Applied SC Physics GA PY378 UT WOS:A1994PY37800017 ER PT J AU CAI, ZX WELCH, DO AF CAI, ZX WELCH, DO TI STRUCTURE OF TWIN BOUNDARIES IN LA2-XBAXCUO4 SO PHYSICA C LA English DT Article AB The structure of the twin boundary in the low-temperature-orthorhombic (LTO) phase of La2-xBaxCuO4 is studied using a Landau-type free-energy model which reproduces the x-T phase diagram. We find that the twin boundaries that have the lowest free energy are those with low-temperature-tetragonal (LTT) structure in the center of the domain walls. Near the LTT-to-LTO phase-transition temperature, both the width as well as the density of the twin boundaries increase with decreasing temperature. C1 BROOKHAVEN NATL LAB,DIV MAT SCI,UPTON,NY 11973. NR 12 TC 5 Z9 5 U1 0 U2 0 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0921-4534 J9 PHYSICA C JI Physica C PD DEC 15 PY 1994 VL 234 IS 3-4 BP 373 EP 379 DI 10.1016/0921-4534(94)90588-6 PG 7 WC Physics, Applied SC Physics GA PY378 UT WOS:A1994PY37800025 ER PT J AU WOODFIELD, BF FISHER, RA PHILLIPS, NE CASPARY, R HELLMANN, P STEGLICH, F WOLF, T AF WOODFIELD, BF FISHER, RA PHILLIPS, NE CASPARY, R HELLMANN, P STEGLICH, F WOLF, T TI EQUALITY OF THE ENTROPIES OF THE LOW-TEMPERATURE ZERO-FIELD UPTURN AND THE IN-FIELD SCHOTTKY ANOMALIES IN THE SPECIFIC-HEAT OF YBA2CU3O7 SO PHYSICA C LA English DT Article ID HIGH-TC SUPERCONDUCTORS; MAGNETIC-FIELDS; ORIGIN; TERM AB Specific-heat measurements on a sample of YBa2Cu3O7 have been extended over a wide enough temperature interval to permit the determination of the entropies of both the zero-field ''upturn'' and the Schottky anomalies that occur in applied fields greater than a few tesla. Within the experimental uncertainty, these entropies are equal, consistent with a model in which both features are associated with the same low concentration of Cu2+ magnetic moments. C1 TECH HOCHSCH DARMSTADT,INST FESTKORPERPHYS,D-64289 DARMSTADT,GERMANY. KERNFORSCHUNGSZENTRUM KARLSRUHE,INST TECH PHYS,D-76021 KARLSRUHE,GERMANY. LAWRENCE BERKELEY LAB,BERKELEY,CA 94720. RP WOODFIELD, BF (reprint author), UNIV CALIF BERKELEY,DEPT CHEM,BERKELEY,CA 94720, USA. NR 19 TC 4 Z9 4 U1 0 U2 2 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0921-4534 J9 PHYSICA C JI Physica C PD DEC 15 PY 1994 VL 234 IS 3-4 BP 380 EP 384 DI 10.1016/0921-4534(94)90589-4 PG 5 WC Physics, Applied SC Physics GA PY378 UT WOS:A1994PY37800026 ER PT J AU MAINIERI, R ECKE, RE AF MAINIERI, R ECKE, RE TI DYNAMIC SCALING FUNCTION AT THE QUASI-PERIODIC TRANSITION TO CHAOS SO PHYSICA D LA English DT Article ID RAYLEIGH-BENARD CONVECTION; STRANGE SETS; BEHAVIOR; CIRCLE; ONSET; MAP AB We obtain a five-step approximation to the quasiperiodic dynamic scaling function for experimental Rayleigh-Bernard convection data. When errors are taken into account in the experiment, the f(alpha) spectrum of scalings is equivalent to just two of these five scales. To overcome this limitation, we develop a robust technique for extracting the scaling function from experimental data by reconstructing the dynamics of the experiment. C1 LOS ALAMOS NATL LAB,DIV PHYS,LOS ALAMOS,NM 87545. RP MAINIERI, R (reprint author), LOS ALAMOS NATL LAB,CTR NONLINEAR STUDIES,LOS ALAMOS,NM 87545, USA. OI Ecke, Robert/0000-0001-7772-5876 NR 22 TC 1 Z9 1 U1 0 U2 1 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0167-2789 J9 PHYSICA D JI Physica D PD DEC 15 PY 1994 VL 79 IS 2-4 BP 193 EP 205 PG 13 WC Mathematics, Applied; Physics, Multidisciplinary; Physics, Mathematical SC Mathematics; Physics GA PY379 UT WOS:A1994PY37900006 ER PT J AU ITOH, KM WALUKIEWICZ, W FUCHS, HD BEEMANM, JW HALLER, EE FARMER, JW OZHOGIN, VI AF ITOH, KM WALUKIEWICZ, W FUCHS, HD BEEMANM, JW HALLER, EE FARMER, JW OZHOGIN, VI TI NEUTRAL-IMPURITY SCATTERING IN ISOTOPICALLY ENGINEERED GE SO PHYSICAL REVIEW B LA English DT Article ID N-TYPE SILICON; SEMICONDUCTORS; TRANSMUTATION; MOBILITY C1 UNIV CALIF BERKELEY,LAWRENCE BERKELEY LAB,BERKELEY,CA 94720. UNIV MISSOURI,COLUMBIA,MO 65211. IV KURCHATOV ATOM ENERGY INST,MOSCOW 123182,RUSSIA. RP ITOH, KM (reprint author), UNIV CALIF BERKELEY,BERKELEY,CA 94720, USA. RI Itoh, Kohei/C-5738-2014 NR 35 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 0163-1829 J9 PHYS REV B JI Phys. Rev. B PD DEC 15 PY 1994 VL 50 IS 23 BP 16995 EP 17000 DI 10.1103/PhysRevB.50.16995 PG 6 WC Physics, Condensed Matter SC Physics GA PZ825 UT WOS:A1994PZ82500021 ER PT J AU GLUTSCH, S SIEGNER, U MYCEK, MA CHEMLA, DS AF GLUTSCH, S SIEGNER, U MYCEK, MA CHEMLA, DS TI FANO RESONANCES DUE TO COUPLED MAGNETOEXCITON AND CONTINUUM STATES IN BULK SEMICONDUCTORS SO PHYSICAL REVIEW B LA English DT Article ID 2-DIMENSIONAL MAGNETOEXCITONS; QUANTUM-WELLS; SPECTRUM; GAAS C1 UNIV CALIF BERKELEY,LAWRENCE BERKELEY LAB,DIV MAT SCI,BERKELEY,CA 94720. RP GLUTSCH, S (reprint author), UNIV CALIF BERKELEY,DEPT PHYS,BERKELEY,CA 94720, USA. NR 25 TC 68 Z9 68 U1 0 U2 6 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 0163-1829 J9 PHYS REV B JI Phys. Rev. B PD DEC 15 PY 1994 VL 50 IS 23 BP 17009 EP 17017 DI 10.1103/PhysRevB.50.17009 PG 9 WC Physics, Condensed Matter SC Physics GA PZ825 UT WOS:A1994PZ82500023 ER PT J AU MCCOY, JM LAFEMINA, JP AF MCCOY, JM LAFEMINA, JP TI MONTE-CARLO SIMULATIONS OF GROWTH OF SB ATOMS ON THE GAAS(110) SURFACE SO PHYSICAL REVIEW B LA English DT Article ID SCANNING-TUNNELING-MICROSCOPY; ELECTRONIC-STRUCTURE; EPITAXIAL-GROWTH; MBE GROWTH; COMPUTER-SIMULATIONS; ENERGY-MINIMIZATION; 110 SURFACES; SEMICONDUCTORS; OVERLAYERS C1 PACIFIC NW LAB, MOLEC SCI RES CTR, RICHLAND, WA 99352 USA. RP MCCOY, JM (reprint author), MONTANA STATE UNIV, DEPT PHYS, BOZEMAN, MT 59717 USA. NR 30 TC 6 Z9 6 U1 1 U2 3 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 0163-1829 J9 PHYS REV B JI Phys. Rev. B PD DEC 15 PY 1994 VL 50 IS 23 BP 17127 EP 17138 DI 10.1103/PhysRevB.50.17127 PG 12 WC Physics, Condensed Matter SC Physics GA PZ825 UT WOS:A1994PZ82500038 ER PT J AU KOGAN, SM AF KOGAN, SM TI THEORETICAL-STUDY OF A QUANTUM-POINT-CONTACT MODEL SO PHYSICAL REVIEW B LA English DT Article ID LOW-FREQUENCY NOISE; BALLISTIC TRANSPORT; CONDUCTANCE; IMPURITY; CONSTRICTIONS; QUANTIZATION; SCATTERING; BREAKDOWN RP KOGAN, SM (reprint author), LOS ALAMOS NATL LAB,POB 1663,LOS ALAMOS,NM 87545, USA. NR 20 TC 0 Z9 0 U1 0 U2 0 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 0163-1829 J9 PHYS REV B JI Phys. Rev. B PD DEC 15 PY 1994 VL 50 IS 23 BP 17230 EP 17241 DI 10.1103/PhysRevB.50.17230 PG 12 WC Physics, Condensed Matter SC Physics GA PZ825 UT WOS:A1994PZ82500050 ER PT J AU MADER, KA ZUNGER, A AF MADER, KA ZUNGER, A TI EMPIRICAL ATOMIC PSEUDOPOTENTIALS FOR ALAS/GAAS SUPERLATTICES, ALLOYS, AND NANOSTRUCTURES SO PHYSICAL REVIEW B LA English DT Article ID (GAAS)N (ALAS)N 001; PRESSURE-DEPENDENCE; HYDROSTATIC-PRESSURE; ELECTRONIC-STRUCTURE; CYCLOTRON-RESONANCE; OPTICAL-PROPERTIES; VALENCE-BAND; GAAS; ALXGA1-XAS; STATES RP MADER, KA (reprint author), NATL RENEWABLE ENERGY LAB,GOLDEN,CO 80401, USA. RI Zunger, Alex/A-6733-2013 NR 55 TC 95 Z9 96 U1 1 U2 2 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 0163-1829 J9 PHYS REV B JI Phys. Rev. B PD DEC 15 PY 1994 VL 50 IS 23 BP 17393 EP 17405 DI 10.1103/PhysRevB.50.17393 PG 13 WC Physics, Condensed Matter SC Physics GA PZ825 UT WOS:A1994PZ82500069 ER PT J AU FEIBELMAN, PJ STUMPF, R AF FEIBELMAN, PJ STUMPF, R TI PHYSICS OF THE BE(0001) SURFACE CORE-LEVEL SPECTRUM SO PHYSICAL REVIEW B LA English DT Article ID ELECTRONIC-STRUCTURE; WAVE CALCULATIONS; BINDING-ENERGY; BRILLOUIN-ZONE; SHIFTS; DENSITY; PSEUDOPOTENTIALS; SEGREGATION; BERYLLIUM; STATES RP FEIBELMAN, PJ (reprint author), SANDIA NATL LABS,POB 5800,ALBUQUERQUE,NM 87185, USA. NR 31 TC 31 Z9 32 U1 0 U2 4 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 0163-1829 J9 PHYS REV B JI Phys. Rev. B PD DEC 15 PY 1994 VL 50 IS 23 BP 17480 EP 17486 DI 10.1103/PhysRevB.50.17480 PG 7 WC Physics, Condensed Matter SC Physics GA PZ825 UT WOS:A1994PZ82500079 ER PT J AU WESTPHAL, C FEGEL, F BANSMANN, J GETZLAFF, M SCHONHENSE, G STEPHENS, JA MCKOY, V AF WESTPHAL, C FEGEL, F BANSMANN, J GETZLAFF, M SCHONHENSE, G STEPHENS, JA MCKOY, V TI ORIENTATION AND SUBSTRATE INTERACTION OF ADSORBED CO AND NO MOLECULES PROBED BY CIRCULAR-DICHROISM IN THE ANGULAR-DISTRIBUTION OF PHOTOELECTRONS SO PHYSICAL REVIEW B LA English DT Article ID ANGLE-RESOLVED PHOTOEMISSION; SYNCHROTRON RADIATION; FE(100) SURFACE; ADSORPTION; NI(100); NI(111); CHEMISORPTION; PD(111); OXYGEN C1 UNIV MAINZ,INST PHYS,D-55128 MAINZ,GERMANY. CALTECH,NOYES LAB CHEM PHYS,PASADENA,CA 91125. RP WESTPHAL, C (reprint author), UNIV CALIF BERKELEY,LAWRENCE BERKELEY LAB,DIV MAT SCI,BERKELEY,CA 94720, USA. RI Bansmann, Joachim/F-2696-2011 OI Bansmann, Joachim/0000-0003-3205-7450 NR 31 TC 13 Z9 13 U1 1 U2 5 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 0163-1829 J9 PHYS REV B JI Phys. Rev. B PD DEC 15 PY 1994 VL 50 IS 23 BP 17534 EP 17539 DI 10.1103/PhysRevB.50.17534 PG 6 WC Physics, Condensed Matter SC Physics GA PZ825 UT WOS:A1994PZ82500086 ER PT J AU RUCKMAN, MW XIA, B SHIH, D AF RUCKMAN, MW XIA, B SHIH, D TI PHOTOEMISSION-STUDY OF IRON DEPOSITED ON FULLERENES SO PHYSICAL REVIEW B LA English DT Note ID ELECTRONIC-STRUCTURE; MAGNETIC-PROPERTIES; CORE-LEVEL; CLUSTERS; FE; DEPENDENCE; PARTICLES; ELEMENTS; FILMS; METAL RP RUCKMAN, MW (reprint author), BROOKHAVEN NATL LAB,DEPT PHYS,UPTON,NY 11973, USA. NR 25 TC 11 Z9 11 U1 0 U2 0 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 0163-1829 J9 PHYS REV B JI Phys. Rev. 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B PD DEC 15 PY 1994 VL 50 IS 24 BP 17811 EP 17819 DI 10.1103/PhysRevB.50.17811 PG 9 WC Physics, Condensed Matter SC Physics GA QB022 UT WOS:A1994QB02200003 ER PT J AU NEUMEIER, JJ HUNDLEY, MF SMITH, MG THOMPSON, JD ALLGEIER, C XIE, H YELON, W KIM, JS AF NEUMEIER, JJ HUNDLEY, MF SMITH, MG THOMPSON, JD ALLGEIER, C XIE, H YELON, W KIM, JS TI MAGNETIC, THERMAL, TRANSPORT, AND STRUCTURAL-PROPERTIES OF SR2RUO4+DELTA - ENHANCED CHARGE-CARRIER MASS IN A NEARLY METALLIC OXIDE SO PHYSICAL REVIEW B LA English DT Article ID FERMI-LIQUID THEORY; NMR EXPERIMENTS; NORMAL-STATE; (LA1-XSRX)2CUO4; YBA2CU3O6+X; SYSTEM; HEAT C1 UNIV MUNICH, SEKT PHYS, D-80799 MUNICH, GERMANY. LOS ALAMOS NATL LAB, CTR SUPERCONDUCT TECHNOL, LOS ALAMOS, NM 87545 USA. UNIV MISSOURI, RES REACTOR FACIL, COLUMBIA, MO 65211 USA. OSRAM GMBH, D-81543 MUNICH, GERMANY. UNIV FLORIDA, DEPT PHYS, GAINESVILLE, FL 32611 USA. RP NEUMEIER, JJ (reprint author), LOS ALAMOS NATL LAB, MS K764, LOS ALAMOS, NM 87545 USA. NR 37 TC 42 Z9 42 U1 1 U2 10 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 DEC 15 PY 1994 VL 50 IS 24 BP 17910 EP 17916 DI 10.1103/PhysRevB.50.17910 PG 7 WC Physics, Condensed Matter SC Physics GA QB022 UT WOS:A1994QB02200013 ER PT J AU AHUJA, R AULUCK, S WILLS, JM ERIKSSON, O SODERLIND, P JOHANSSON, B AF AHUJA, R AULUCK, S WILLS, JM ERIKSSON, O SODERLIND, P JOHANSSON, B TI FERMI-SURFACE OF ALKALI-METALS USING THE FULL-POTENTIAL LINEAR-MUFFIN-TIN-ORBITAL METHOD AND THE GENERALIZED GRADIENT APPROXIMATION SO PHYSICAL REVIEW B LA English DT Article ID BRILLOUIN-ZONE; SPECIAL POINTS; HIGH-PRESSURE; EXCHANGE; TRANSITIONS; POTASSIUM; SYSTEMS; ENERGY; BAND C1 UNIV ROORKEE,DEPT PHYS,ROORKEE 247667,UTTAR PRADESH,INDIA. LOS ALAMOS NATL LAB,DIV THEORET,LOS ALAMOS,NM 87545. RP AHUJA, R (reprint author), UPPSALA UNIV,DEPT PHYS,CONDENSED MATTER THEORY GRP,BOX 530,UPPSALA,SWEDEN. RI Eriksson, Olle/E-3265-2014 OI Eriksson, Olle/0000-0001-5111-1374 NR 38 TC 4 Z9 4 U1 0 U2 1 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 0163-1829 J9 PHYS REV B JI Phys. Rev. B PD DEC 15 PY 1994 VL 50 IS 24 BP 18003 EP 18006 DI 10.1103/PhysRevB.50.18003 PG 4 WC Physics, Condensed Matter SC Physics GA QB022 UT WOS:A1994QB02200018 ER PT J AU HUNDLEY, MF CANFIELD, PC THOMPSON, JD FISK, Z AF HUNDLEY, MF CANFIELD, PC THOMPSON, JD FISK, Z TI SUBSTITUTIONAL EFFECTS ON THE ELECTRONIC TRANSPORT OF THE KONDO SEMICONDUCTOR CE3BI4PT3 SO PHYSICAL REVIEW B LA English DT Article ID HYBRIDIZATION GAP; ENERGY-GAP RP HUNDLEY, MF (reprint author), LOS ALAMOS NATL LAB,LOS ALAMOS,NM 87545, USA. RI Canfield, Paul/H-2698-2014 NR 24 TC 37 Z9 37 U1 2 U2 10 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 0163-1829 J9 PHYS REV B JI Phys. Rev. B PD DEC 15 PY 1994 VL 50 IS 24 BP 18142 EP 18146 DI 10.1103/PhysRevB.50.18142 PG 5 WC Physics, Condensed Matter SC Physics GA QB022 UT WOS:A1994QB02200035 ER PT J AU MIYAMOTO, Y RUBIO, A LOUIE, SG COHEN, ML AF MIYAMOTO, Y RUBIO, A LOUIE, SG COHEN, ML TI ELECTRONIC-PROPERTIES OF TUBULE FORMS OF HEXAGONAL BC3 SO PHYSICAL REVIEW B LA English DT Article ID CARBON; MICROTUBULES; GRAPHITE C1 UNIV CALIF BERKELEY,LAWRENCE BERKELEY LAB,DIV MAT SCI,BERKELEY,CA 94720. NEC CORP LTD,FUNDAMENTAL RES LABS,TSUKUBA,IBARAKI 305,JAPAN. UNIV VALLADOLID,DEPT FIS TEOR,E-47011 VALLADOLID,SPAIN. RP MIYAMOTO, Y (reprint author), UNIV CALIF BERKELEY,DEPT PHYS,BERKELEY,CA 94720, USA. RI Rubio, Angel/A-5507-2008; OI Rubio, Angel/0000-0003-2060-3151; Miyamoto, Yoshiyuki/0000-0001-6834-0499 NR 17 TC 192 Z9 194 U1 1 U2 7 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 0163-1829 J9 PHYS REV B JI Phys. Rev. B PD DEC 15 PY 1994 VL 50 IS 24 BP 18360 EP 18366 DI 10.1103/PhysRevB.50.18360 PG 7 WC Physics, Condensed Matter SC Physics GA QB022 UT WOS:A1994QB02200061 ER PT J AU REYNOLDS, GAM FUNG, AWP WANG, ZH DRESSELHAUS, MS PEKALA, RW AF REYNOLDS, GAM FUNG, AWP WANG, ZH DRESSELHAUS, MS PEKALA, RW TI MORPHOLOGICAL EFFECTS ON THE TRANSPORT AND MAGNETIC-PROPERTIES OF POLYMERIC AND COLLOIDAL CARBON AEROGELS SO PHYSICAL REVIEW B LA English DT Article ID GRANULAR METALS; HOPPING CONDUCTIVITY; DEPENDENCE C1 MIT,DEPT ELECT ENGN & COMP SCI,CAMBRIDGE,MA 02139. MIT,FRANCIS BITTER NATL MAGNET LAB,CAMBRIDGE,MA 02139. LAWRENCE LIVERMORE NATL LAB,DEPT CHEM & MAT SCI,LIVERMORE,CA 94550. RP REYNOLDS, GAM (reprint author), MIT,DEPT PHYS,CAMBRIDGE,MA 02139, USA. NR 25 TC 12 Z9 13 U1 2 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 DEC 15 PY 1994 VL 50 IS 24 BP 18590 EP 18600 DI 10.1103/PhysRevB.50.18590 PG 11 WC Physics, Condensed Matter SC Physics GA QB022 UT WOS:A1994QB02200085 ER PT J AU KANNER, GS GAMMEL, JT LOVE, SP JOHNSON, SR SCOTT, B SWANSON, BI AF KANNER, GS GAMMEL, JT LOVE, SP JOHNSON, SR SCOTT, B SWANSON, BI TI PRESSURE TUNING OF THE CHARGE-DENSITY-WAVE IN THE HALOGEN-BRIDGED TRANSITION-METAL SOLID PT2BR6(NH3)(4) SO PHYSICAL REVIEW B LA English DT Note ID LINEAR-CHAIN COMPOUNDS; DIAMOND-ANVIL CELL; PHASE-TRANSITION; RAMAN FREQUENCY; MX SOLIDS; STATE; DEPENDENCE; BROMIDE; MODEL RP KANNER, GS (reprint author), LOS ALAMOS NATL LAB, LOS ALAMOS, NM 87545 USA. RI Scott, Brian/D-8995-2017; OI Scott, Brian/0000-0003-0468-5396; Love, Steven/0000-0003-0588-9622 NR 32 TC 21 Z9 21 U1 1 U2 3 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 DEC 15 PY 1994 VL 50 IS 24 BP 18682 EP 18685 DI 10.1103/PhysRevB.50.18682 PG 4 WC Physics, Condensed Matter SC Physics GA QB022 UT WOS:A1994QB02200103 ER PT J AU MAIA, MD SILVA, GS AF MAIA, MD SILVA, GS TI GEOMETRICAL CONSTRAINTS ON THE COSMOLOGICAL CONSTANT SO PHYSICAL REVIEW D LA English DT Article ID PERTURBATIONS C1 NASA,FERMILAB ASTROPHYS CTR,FERMI NATL ACCELERATOR LAB,BATAVIA,IL 60510. RP MAIA, MD (reprint author), UNIV BRASILIA,DEPT MATEMAT,BR-70910900 BRASILIA,DF,BRAZIL. OI maia, marcos/0000-0003-0094-7686 NR 19 TC 23 Z9 24 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 DEC 15 PY 1994 VL 50 IS 12 BP 7233 EP 7238 DI 10.1103/PhysRevD.50.7233 PG 6 WC Astronomy & Astrophysics; Physics, Particles & Fields SC Astronomy & Astrophysics; Physics GA PY499 UT WOS:A1994PY49900014 ER PT J AU FRABETTI, PL CHEUNG, HWK CUMALAT, JP DALLAPICCOLA, C GINKEL, JF GREENE, SV JOHNS, WE NEHRING, MS BUTLER, JN CIHANGIR, S GAINES, I GARBINCIUS, PH GARREN, L GOURLAY, SA HARDING, DJ KASPER, P KREYMER, A LEBRUN, P SHUKLA, S BIANCO, S FABBRI, FL SARWAR, S ZALLO, A CULBERTSON, R GARDNER, RW GREENE, R WISS, J ALIMONTI, G BELLINI, G CACCIANIGA, B CINQUINI, L DICORATO, M GIAMMARCHI, M INZANI, P LEVERARO, F MALVEZZI, S MENASCE, D MERONI, E MORONI, L PEDRINI, D PERASSO, L SALA, A SALA, S TORRETTA, D VITTONE, M BUCHHOLZ, D CLAES, D GOBBI, B OREILLY, B BISHOP, JM CASON, NM KENNEDY, CJ KIM, GN LIN, TF PUSELJIC, DL RUCHTI, RC SHEPHARD, WD SWIATEK, JA WU, ZY ARENA, V BOCA, G CASTOLDI, C GIANINI, G RATTI, SP RICCARDI, C VITULO, P LOPEZ, A GRIM, GP PAOLONE, VS YAGER, PM WILSON, JR SHELDON, PD DAVENPORT, F BLACKETT, GR PISHARODY, M HANDLER, T CHEON, BG KANG, JS KIM, KY AF FRABETTI, PL CHEUNG, HWK CUMALAT, JP DALLAPICCOLA, C GINKEL, JF GREENE, SV JOHNS, WE NEHRING, MS BUTLER, JN CIHANGIR, S GAINES, I GARBINCIUS, PH GARREN, L GOURLAY, SA HARDING, DJ KASPER, P KREYMER, A LEBRUN, P SHUKLA, S BIANCO, S FABBRI, FL SARWAR, S ZALLO, A CULBERTSON, R GARDNER, RW GREENE, R WISS, J ALIMONTI, G BELLINI, G CACCIANIGA, B CINQUINI, L DICORATO, M GIAMMARCHI, M INZANI, P LEVERARO, F MALVEZZI, S MENASCE, D MERONI, E MORONI, L PEDRINI, D PERASSO, L SALA, A SALA, S TORRETTA, D VITTONE, M BUCHHOLZ, D CLAES, D GOBBI, B OREILLY, B BISHOP, JM CASON, NM KENNEDY, CJ KIM, GN LIN, TF PUSELJIC, DL RUCHTI, RC SHEPHARD, WD SWIATEK, JA WU, ZY ARENA, V BOCA, G CASTOLDI, C GIANINI, G RATTI, SP RICCARDI, C VITULO, P LOPEZ, A GRIM, GP PAOLONE, VS YAGER, PM WILSON, JR SHELDON, PD DAVENPORT, F BLACKETT, GR PISHARODY, M HANDLER, T CHEON, BG KANG, JS KIM, KY TI BRANCHING RATIOS OF THE DECAYS D-0-](K(0))OVER-BAR-K(0) AND D-0-]KS(0)KS(0)KS(0) SO PHYSICS LETTERS B LA English DT Article ID D0 AB The branching ratios of D-0 --> ($) over bar (KK0)-K-0 and D-0 --> (KsKsK)-K-0-K-0(s)(0) relative to D-0 --> ($) over bar K-0 pi(+)pi(-) are reported. The data were accumulated in the 1990-1991 fixed target running period of the Fermilab high energy photoproduction experiment E687. Gamma(D-0 --> ($) over bar (KK0)-K-0)/Gamma(D-0 --> ($) over bar K-0 pi(+)pi(-)) is measured to be 0.039 +/- 0.013 +/- 0.013 and Gamma(D-0 --> (KsKsKs0)-K-0-K-0/Gamma(D-0 --> ($) over bar K-0 pi(+)pi(-))is measured to be 0.035 +/- 0.012 +/- 0.006. We also measure Gamma(D-0 --> <($)over ($) over bar K-0 pi(+)pi(-))/Gamma(D-0 --> K(-)pi(+)) to be 1.61 +/- 0.10 +/- 0.15. C1 INFN,I-40126 BOLOGNA,ITALY. UNIV COLORADO,BOULDER,CO 80309. FERMILAB NATL ACCELERATOR LAB,BATAVIA,IL 60510. UNIV ILLINOIS,URBANA,IL 61801. UNIV MILAN,DIPARTIMENTO FIS,I-20133 MILAN,ITALY. IST NAZL FIS NUCL,I-20133 MILAN,ITALY. NORTHWESTERN UNIV,EVANSTON,IL 60208. UNIV NOTRE DAME,NOTRE DAME,IN 46556. UNIV PAVIA,DIPARTIMENTO FIS NUCL & TEOR,I-27100 PAVIA,ITALY. IST NAZL FIS NUCL,I-27100 PAVIA,ITALY. UNIV PUERTO RICO,MAYAGUEZ,PR. UNIV CALIF DAVIS,DAVIS,CA 95616. UNIV S CAROLINA,COLUMBIA,SC 29208. VANDERBILT UNIV,NASHVILLE,TN 37235. UNIV N CAROLINA,ASHEVILLE,NC 28804. UNIV TENNESSEE,KNOXVILLE,TN 37996. KOREA UNIV,SEOUL 136701,SOUTH KOREA. RP FRABETTI, PL (reprint author), UNIV BOLOGNA,DIPARTMENTO FIS,I-40126 BOLOGNA,ITALY. NR 10 TC 6 Z9 6 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 DEC 15 PY 1994 VL 340 IS 4 BP 254 EP 258 DI 10.1016/0370-2693(94)01346-2 PG 5 WC Astronomy & Astrophysics; Physics, Nuclear; Physics, Particles & Fields SC Astronomy & Astrophysics; Physics GA PW976 UT WOS:A1994PW97600008 ER PT J AU AMSLER, C ARMSTRONG, DS AUGUSTIN, I BAKER, CA BARNETT, BM BATTY, CJ BEUCHERT, K BIRIEN, P BLUM, P BOSSINGHAM, R BRAUNE, K BROSE, J BUGG, DV BURCHELL, M CASE, T CHUNG, SU COOPER, A CRAMER, O CROWE, KM DEGENER, T DIETZ, HP VONDOMBROWSKI, S DOSER, M DUNNWEBER, W ENGELHARDT, D ENGLERT, M FAESSLER, MA FELIX, C HACKMANN, R HADDOCK, RP HEINSIUS, FH HERZ, M HESSEY, NP HIDAS, P ILLINGER, P JAMNIK, D KALINOWSKY, H KAMMLE, B KIEL, T KISIEL, J KLEMPT, E KOBEL, M KOCH, H KOLO, C KONIGSMANN, K KUNZE, M LAKATA, M LANDUA, R LOSER, F LUDEMANN, J MATTHAY, H MERKEL, M MERLO, JP MEYER, CA MONTANET, L NOBLE, A OULDSAADA, F PETERS, K PINDER, CN PINTER, G RAVNDAL, S SALK, J SCHAFER, E SEIBERT, R SCHMIDT, P SPANIER, S STRASSBURGER, C STROHBUSCH, U SUFFERT, M URNER, D VOLCKER, C WALTER, F WALTHER, D WIEDNER, U WINTER, N ZOLL, J ZOU, BS ZUPANCIC, C AF AMSLER, C ARMSTRONG, DS AUGUSTIN, I BAKER, CA BARNETT, BM BATTY, CJ BEUCHERT, K BIRIEN, P BLUM, P BOSSINGHAM, R BRAUNE, K BROSE, J BUGG, DV BURCHELL, M CASE, T CHUNG, SU COOPER, A CRAMER, O CROWE, KM DEGENER, T DIETZ, HP VONDOMBROWSKI, S DOSER, M DUNNWEBER, W ENGELHARDT, D ENGLERT, M FAESSLER, MA FELIX, C HACKMANN, R HADDOCK, RP HEINSIUS, FH HERZ, M HESSEY, NP HIDAS, P ILLINGER, P JAMNIK, D KALINOWSKY, H KAMMLE, B KIEL, T KISIEL, J KLEMPT, E KOBEL, M KOCH, H KOLO, C KONIGSMANN, K KUNZE, M LAKATA, M LANDUA, R LOSER, F LUDEMANN, J MATTHAY, H MERKEL, M MERLO, JP MEYER, CA MONTANET, L NOBLE, A OULDSAADA, F PETERS, K PINDER, CN PINTER, G RAVNDAL, S SALK, J SCHAFER, E SEIBERT, R SCHMIDT, P SPANIER, S STRASSBURGER, C STROHBUSCH, U SUFFERT, M URNER, D VOLCKER, C WALTER, F WALTHER, D WIEDNER, U WINTER, N ZOLL, J ZOU, BS ZUPANCIC, C TI ETA-ETA' THRESHOLD ENHANCEMENT IN (P)OVER-BAR-P ANNIHILATIONS INTO PI(0)ETA-ETA' AT REST SO PHYSICS LETTERS B LA English DT Article ID PI AB We report on the observation of an eta eta' threshold enhancement produced in ($) over bar pp annihilations at rest into pi(0) eta eta', which we identify with the recently discovered f(0)(1500). C1 RUHR UNIV BOCHUM,D-44780 BOCHUM,GERMANY. UNIV BONN,D-53115 BONN,GERMANY. HUNGARIAN ACAD SCI,H-1525 BUDAPEST,HUNGARY. RUTHERFORD APPLETON LAB,DIDCOT OX11 0QX,OXON,ENGLAND. CERN,CH-1211 GENEVA,SWITZERLAND. UNIV HAMBURG,D-22761 HAMBURG,GERMANY. UNIV KARLSRUHE,D-76344 KARLSRUHE,GERMANY. UNIV LONDON QUEEN MARY & WESTFIELD COLL,LONDON E1 4NS,ENGLAND. UNIV CALIF LOS ANGELES,LOS ANGELES,CA 90024. UNIV MAINZ,D-55099 MAINZ,GERMANY. UNIV MUNICH,D-80333 MUNICH,GERMANY. CARNEGIE MELLON UNIV,PITTSBURGH,PA 15213. CTR RECH NUCL,F-67037 STRASBOURG,FRANCE. UNIV ZURICH,CH-8057 ZURICH,SWITZERLAND. RP AMSLER, C (reprint author), UNIV CALIF BERKELEY,LAWRENCE BERKELEY LAB,BERKELEY,CA 94720, USA. RI Meyer, Curtis/L-3488-2014 OI Meyer, Curtis/0000-0001-7599-3973 NR 10 TC 73 Z9 73 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 DEC 15 PY 1994 VL 340 IS 4 BP 259 EP 263 DI 10.1016/0370-2693(94)01347-0 PG 5 WC Astronomy & Astrophysics; Physics, Nuclear; Physics, Particles & Fields SC Astronomy & Astrophysics; Physics GA PW976 UT WOS:A1994PW97600009 ER PT J AU NIEH, TG IMAI, T WADSWORTH, J KOJIM, AS AF NIEH, TG IMAI, T WADSWORTH, J KOJIM, AS TI HIGH-STRAIN RATE SUPERPLASTICITY OF A POWDER-METALLURGY SIC PARTICULATE-REINFORCED 6061-AL COMPOSITE (6061/SIC/17.5P) SO SCRIPTA METALLURGICA ET MATERIALIA LA English DT Article ID ALUMINUM COMPOSITE; ALLOY; BEHAVIOR C1 NATL IND RES INST NAGOYA,KITA KU,NAGOYA 462,JAPAN. NAGOYA MUNICIPAL IND RES INST,ATSUTA KU,NAGOYA 456,JAPAN. RP NIEH, TG (reprint author), LAWRENCE LIVERMORE NATL LAB,POB 808L-350,LIVERMORE,CA 94550, USA. RI Nieh, Tai-Gang/G-5912-2011 OI Nieh, Tai-Gang/0000-0002-2814-3746 NR 20 TC 41 Z9 41 U1 0 U2 0 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD, ENGLAND OX5 1GB SN 0956-716X J9 SCRIPTA METALL MATER JI Scr. Metall. Materialia PD DEC 15 PY 1994 VL 31 IS 12 BP 1685 EP 1690 DI 10.1016/0956-716X(94)90464-2 PG 6 WC Materials Science, Multidisciplinary; Metallurgy & Metallurgical Engineering SC Materials Science; Metallurgy & Metallurgical Engineering GA PJ362 UT WOS:A1994PJ36200015 ER PT J AU SCHNEIBEL, JH SPECHT, ED AF SCHNEIBEL, JH SPECHT, ED TI SLOW CRACK-GROWTH IN TERNARY B2 IRON ALUMINIDES AT ROOM-TEMPERATURE SO SCRIPTA METALLURGICA ET MATERIALIA LA English DT Article ID COOLING RATE; AL ALLOYS; FEAL; BORON; EMBRITTLEMENT; HARDNESS RP SCHNEIBEL, JH (reprint author), OAK RIDGE NATL LAB,DIV MET & CERAM,OAK RIDGE,TN 37831, USA. RI Specht, Eliot/A-5654-2009 OI Specht, Eliot/0000-0002-3191-2163 NR 16 TC 7 Z9 7 U1 0 U2 2 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD, ENGLAND OX5 1GB SN 0956-716X J9 SCRIPTA METALL MATER JI Scr. Metall. Materialia PD DEC 15 PY 1994 VL 31 IS 12 BP 1737 EP 1742 DI 10.1016/0956-716X(94)90474-X PG 6 WC Materials Science, Multidisciplinary; Metallurgy & Metallurgical Engineering SC Materials Science; Metallurgy & Metallurgical Engineering GA PJ362 UT WOS:A1994PJ36200025 ER PT J AU EXARHOS, GJ WANG, LQ DENNIS, T AF EXARHOS, GJ WANG, LQ DENNIS, T TI SPATIALLY-RESOLVED DENSIFICATION OF SOLUTION DEPOSITED ZIRCONIUM DIOXIDE FILMS BY LASER IRRADIATION SO THIN SOLID FILMS LA English DT Article DE DEPOSITION PROCESS; FLUORESCENCE; LASER IRRADIATION; PHASE TRANSITIONS ID INDUCED CRYSTALLIZATION; GELS AB CW laser irradiation of glassy oxide films deposited from aqueous precursor solutions leads to localized densification within the laser footprint rendering that segment of the film water insoluble. Subsequent washing followed by thermal annealing transforms the densified region that remains into a fine grain polycrystalline material. Atomic force microscopy and ellipsometry are used to characterize the surface morphology and optical constants of the film during processing while laser- induced fluorescence from a rare earth dopant (Sm3+) intentionally introduced into the film provides a rapid in situ means of characterizing the evolving crystalline phase and phase purity. Spatially resolved regions of tetragonal ZrO2, 40 nm thick and 2 mu m wide, which have been doped with Sm3+ have been imprinted onto Si(100) substrates. The physical characteristics and morphology of the imprinted regions are compared with similar solution-deposited films which were subjected to thermal annealing alone. C1 RICE UNIV, HOUSTON, TX 77251 USA. RP EXARHOS, GJ (reprint author), PACIFIC NW LAB, POB 999, RICHLAND, WA 99352 USA. NR 15 TC 10 Z9 10 U1 0 U2 2 PU ELSEVIER SCIENCE SA LAUSANNE PI LAUSANNE 1 PA PO BOX 564, 1001 LAUSANNE 1, SWITZERLAND SN 0040-6090 J9 THIN SOLID FILMS JI Thin Solid Films PD DEC 15 PY 1994 VL 253 IS 1-2 BP 41 EP 46 DI 10.1016/0040-6090(94)90291-7 PG 6 WC Materials Science, Multidisciplinary; Materials Science, Coatings & Films; Physics, Applied; Physics, Condensed Matter SC Materials Science; Physics GA PX356 UT WOS:A1994PX35600008 ER PT J AU CARDINALE, GF MIRKARIMI, PB MCCARTY, KF KLAUS, EJ MEDLIN, DL CLIFT, WM HOWITT, DG AF CARDINALE, GF MIRKARIMI, PB MCCARTY, KF KLAUS, EJ MEDLIN, DL CLIFT, WM HOWITT, DG TI EFFECTS OF AMBIENT CONDITIONS ON THE ADHESION OF CUBIC BORON-NITRIDE FILMS ON SILICON SUBSTRATES SO THIN SOLID FILMS LA English DT Article DE BORON NITRIDE; COATINGS ID THIN-FILMS; STRESS AB The influence of environmental conditions on cubic boron nitride (cBN) film adhesion to silicon substrates was investigated. cBN films were deposited on (100)-oriented silicon substrates by ion-assisted pulsed laser deposition. The irradiating ions were mixtures of nitrogen with (i) argon, (ii) krypton and (iii) xenon. Under room-ambient conditions, the films delaminated in the following time order: N/Xe, N/Kr and N/Ar. cBN films deposited using N/Xe ion-assisted deposition were exposed to four environmental conditions for several weeks: a 1 mTorr vacuum, high humidity, dry oxygen and dry nitrogen. Films exposed to the humid environment delaminated whereas those stored under vacuum or in dry gases did not. Films stored in dry nitrogen were removed after nearly 2 weeks and placed in the high-humidity chamber; these films subsequently delaminated with 14 h. It is concluded that the presence of a humid environment facilitates the delamination of BN thin films from silicon substrates. A model of the interaction between water and the interfacial material is also presented. C1 SANDIA NATL LABS,LIVERMORE,CA 95550. RP CARDINALE, GF (reprint author), UNIV CALIF DAVIS,DAVIS,CA 95616, USA. RI McCarty, Kevin/F-9368-2012 OI McCarty, Kevin/0000-0002-8601-079X NR 30 TC 52 Z9 52 U1 1 U2 4 PU ELSEVIER SCIENCE SA LAUSANNE PI LAUSANNE 1 PA PO BOX 564, 1001 LAUSANNE 1, SWITZERLAND SN 0040-6090 J9 THIN SOLID FILMS JI Thin Solid Films PD DEC 15 PY 1994 VL 253 IS 1-2 BP 130 EP 135 DI 10.1016/0040-6090(94)90307-7 PG 6 WC Materials Science, Multidisciplinary; Materials Science, Coatings & Films; Physics, Applied; Physics, Condensed Matter SC Materials Science; Physics GA PX356 UT WOS:A1994PX35600024 ER PT J AU LIN, YP KRAUSS, AR CHANG, RPH AUCIELLO, OH GRUEN, DM SCHULTZ, JA AF LIN, YP KRAUSS, AR CHANG, RPH AUCIELLO, OH GRUEN, DM SCHULTZ, JA TI ATMOSPHERE INFLUENCE ON IN-SITU ION-BEAM ANALYSIS OF THIN-FILM GROWTH SO THIN SOLID FILMS LA English DT Article DE ION SCATTERING; SPUTTERING; SURFACE COMPOSITION; SURFACE STRUCTURE ID SCATTERING; SURFACE AB In-situ non-destructive surface characterization of thin film growth processes in an environment of chemically active gas at pressures of several millitorrs is required both for the understanding of growth processes in multicomponent films and layered heterostructures and for the improvement of process reproducibility and device reliability. We have developed a differentially pumped pulsed ion beam surface analysis system that includes ion scattering spectroscopy (ISS) and direct recoil spectroscopy (DRS), coupled to an automated ion beam sputter deposition system, to study film growth processes in an environment of chemically active gas, such as required for the growth of oxide, nitride or diamond thin films. The influence of gas-phase scattering and gas-surface interactions on the ISS and DRS signal intensity and peak shape has been studied. From the intensity variation as a function of ambient gas pressure, we have calculated the mean free path and the scattering cross-section for several combinations of primary ion species and ambient gas. Depending on the system geometry and the combination of primary beam and background gas, it is shown that surface-specific data can be obtained during thin film growth at pressures ranging up to several millitorrs. Detailed information such as surface composition, structure and film growth mechanism may be obtained in real time, making ion beam analysis an ideal non-destructive in-situ probe of thin film growth processes. C1 ARGONNE NATL LAB, DIV CHEM, ARGONNE, IL 60439 USA. NORTHWESTERN UNIV, DEPT MAT SCI & ENGN, EVANSTON, IL 60208 USA. MICROELECTR CTR N CAROLINA, RES TRIANGLE PK, NC 27709 USA. IONWERKS INC, HOUSTON, TX USA. RP LIN, YP (reprint author), ARGONNE NATL LAB, DIV MAT SCI, ARGONNE, IL 60439 USA. RI Chang, R.P.H/B-7505-2009 NR 14 TC 9 Z9 9 U1 0 U2 3 PU ELSEVIER SCIENCE SA PI LAUSANNE PA PO BOX 564, 1001 LAUSANNE, SWITZERLAND SN 0040-6090 J9 THIN SOLID FILMS JI Thin Solid Films PD DEC 15 PY 1994 VL 253 IS 1-2 BP 247 EP 253 DI 10.1016/0040-6090(94)90329-8 PG 7 WC Materials Science, Multidisciplinary; Materials Science, Coatings & Films; Physics, Applied; Physics, Condensed Matter SC Materials Science; Physics GA PX356 UT WOS:A1994PX35600046 ER PT J AU BARR, TL SEAL, S CHEN, LM KAO, CC AF BARR, TL SEAL, S CHEN, LM KAO, CC TI A NEW INTERPRETATION OF THE BINDING-ENERGIES IN X-RAY PHOTOELECTRON STUDIES OF OXIDES SO THIN SOLID FILMS LA English DT Article DE ALUMINUM OXIDE; BINDING ENERGY; CHARGING; OXIDATION; OXIDES ID SPECTROSCOPY; CATALYSTS; OXIDATION; AL(111); XPS AB Films and coatings applied to different substrates are often various types of oxides. The latter are employed for a number of reasons with particular emphasis on their lack of chemical and electrical porosity. It is generally important therefore to have some measure of the physical and chemical integrity of the resulting oxide films and their interfaces with the substrate. The latter is often realized by using X-ray photoelectron spectroscopy or electron spectroscopy for chemical analysis. In order to accomplish this, it is common practice to utilize the (now generally well accepted) binding energy data from the literature to verify and expand upon one's results. Unfortunately, close scrutiny reveals a number of major discrepancies in these literature results for certain key oxides. Thus, for example, a significant portion of the literature reports the Al 2p level of Al2O3 at similar to 75.7 +/- 0.3 eV, whereas many others specify similar to 74.0 +/- 0.2 eV. Perhaps the greatest difficulty with this observation is that it can be shown that, based upon their respective methods of analysis, both results are equally valid. In the present investigation, we examine the extent and nature of this problem. We have discovered that there are particular types of oxides that exhibit this dichotomy in binding energies, whereas others do not. The role played by bonding and morphology in these differences is explored, as is the effect of the different methods of binding energy determination. Finally, we shall describe how the mechanism of the growth of oxides is the principal ''culprit'' and a lack of understanding of the latter and its electronic implications may lead many to an incorrect interpretation of ''true'' binding energies. C1 BROOKHAVEN NATL LAB,NATL SYNCHROTRON LIGHT SOURCE DEPT,UPTON,NY 11973. RP BARR, TL (reprint author), UNIV WISCONSIN,DEPT MAT,SURFACE STUDIES LAB,MILWAUKEE,WI 53201, USA. NR 24 TC 50 Z9 50 U1 1 U2 6 PU ELSEVIER SCIENCE SA LAUSANNE PI LAUSANNE 1 PA PO BOX 564, 1001 LAUSANNE 1, SWITZERLAND SN 0040-6090 J9 THIN SOLID FILMS JI Thin Solid Films PD DEC 15 PY 1994 VL 253 IS 1-2 BP 277 EP 284 DI 10.1016/0040-6090(94)90334-4 PG 8 WC Materials Science, Multidisciplinary; Materials Science, Coatings & Films; Physics, Applied; Physics, Condensed Matter SC Materials Science; Physics GA PX356 UT WOS:A1994PX35600051 ER PT J AU ERCK, RA AF ERCK, RA TI PIN-PULL ADHESION MEASUREMENTS OF COPPER-FILMS ON ION-BOMBARDED ALUMINA SO THIN SOLID FILMS LA English DT Article DE ADHESION; ALUMINUM OXIDE; COPPER; ION BOMBARDMENT AB Copper films were deposited by evaporation onto aluminal substrates that had been sputtered to various doses with 500 eV ions. The adhesion strength of the films was measured with a pull-type adhesion tester. The adhesion of Cu to solvent-cleaned surfaces was low, but argon ion sputter cleaning produced adhesion near 80 MPa, and adhesion after oxygen ion bombardment was even better. Exposing the alumina to argon-oxygen plasma discharge (approximate to 40 eV ions) from the Kaufman-type ion source increased the adhesion beyond approximate to 55 MPa. The applicability of Weibull statistical analysis to the distribution of pull test data for solvent-cleaned rough alumina was investigated. A good fit of the data to the Weibull expression was observed, with zero apparent threshold strength and a low Weibull modulus of approximate to 2.9. RP ERCK, RA (reprint author), ARGONNE NATL LAB, DIV ENERGY TECHNOL, 9700 S CASS AVE, ARGONNE, IL 60439 USA. NR 16 TC 7 Z9 7 U1 0 U2 1 PU ELSEVIER SCIENCE SA PI LAUSANNE PA PO BOX 564, 1001 LAUSANNE, SWITZERLAND SN 0040-6090 J9 THIN SOLID FILMS JI Thin Solid Films PD DEC 15 PY 1994 VL 253 IS 1-2 BP 362 EP 366 DI 10.1016/0040-6090(94)90348-4 PG 5 WC Materials Science, Multidisciplinary; Materials Science, Coatings & Films; Physics, Applied; Physics, Condensed Matter SC Materials Science; Physics GA PX356 UT WOS:A1994PX35600065 ER PT J AU BERRY, LA GORBATKIN, SM RHOADES, RL AF BERRY, LA GORBATKIN, SM RHOADES, RL TI CU DEPOSITION USING A PERMANENT-MAGNET ELECTRON-CYCLOTRON-RESONANCE MICROWAVE PLASMA SOURCE SO THIN SOLID FILMS LA English DT Article DE COPPER; DEPOSITION PROCESS; METALLIZATION; PLASMA PROCESSING AND DEPOSITION ID FIELD AB An elecron cyclotron resonance (ECR) plasma has been used in conjunction with a solid metal sputter target for Cu deposition over a 200 mm diameter. The goal is to develop a deposition process suitable for filling submicron, high aspect ratio features used for ultralarge-scale integration. The system uses a permanent magnet for creation of the magnetic field necessary for ECR and is significantly more compact than systems equipped with electromagnets. A custom launcher design allows remote microwave injection with the microwave entrance window shielded from the Cu flux. Cu deposition rates up to 100 nm min(-1) were observed and film resistivities were typically in the low to mid 2 mu Omega cm range. On the basis of deposition rate measurements at two radial sample positions, uniformities of a few per cent over a 200 mm wafer should be attainable. RP BERRY, LA (reprint author), OAK RIDGE NATL LAB,OAK RIDGE,TN 37831, USA. NR 18 TC 4 Z9 4 U1 0 U2 0 PU ELSEVIER SCIENCE SA LAUSANNE PI LAUSANNE 1 PA PO BOX 564, 1001 LAUSANNE 1, SWITZERLAND SN 0040-6090 J9 THIN SOLID FILMS JI Thin Solid Films PD DEC 15 PY 1994 VL 253 IS 1-2 BP 382 EP 385 DI 10.1016/0040-6090(94)90352-2 PG 4 WC Materials Science, Multidisciplinary; Materials Science, Coatings & Films; Physics, Applied; Physics, Condensed Matter SC Materials Science; Physics GA PX356 UT WOS:A1994PX35600069 ER PT J AU LIN, XW LAMPERT, WV SWIDER, W HAAS, TW HOLLOWAY, PH WASHBURN, J LILIENTALWEBER, Z AF LIN, XW LAMPERT, WV SWIDER, W HAAS, TW HOLLOWAY, PH WASHBURN, J LILIENTALWEBER, Z TI MORPHOLOGY OF AL-NI-GE OHMIC CONTACTS TO N-GAAS AS A FUNCTION OF CONTACT COMPOSITION SO THIN SOLID FILMS LA English DT Article DE CONTACTS; GALLIUM ARSENIDE; METALLIZATION; SURFACE MORPHOLOGY ID COMPOUND SEMICONDUCTORS; MICROSTRUCTURE AB Al-Ni-Ge ohmic contacts on n-GaAs(001) were prepared by sequential vapor deposition and subsequent annealing at 500 degrees C. Structural properties were studied as a function of contact composition, by transmission electron microscopy and scanning electron microscopy, in addition to other techniques. In all cases, Al was deposited as the top layer at a fixed thickness. While all metallizations exhibit a non-spiking interface with the GaAs substrate, it was found that the contact morphology varies strongly with the Ge:Ni thickness ratio. For a Ge:Ni thickness ratio of 3:4 or greater, annealing results in the formation of a thick Al3Ni layer adjacent to the GaAs substrate, as well as a non-uniform surface layer, characterized by dendritic Ge precipitates in an Al matrix. By lowering the Ge:Ni thickness ratio to 1:2, the surface morphology was greatly improved and the contact displays a stable layered structure of the type Al3Ni/(Ni-Ge)/GaAs. These results were accounted for on the basis of a recently developed Al-Ni-Ge ternary phase diagram. C1 USAF,WRIGHT LAB,MAT DIRECTORATE,WRIGHT PATTERSON AFB,OH 45433. UNIV FLORIDA,DEPT MAT SCI & ENGN,GAINESVILLE,FL 32611. RP LIN, XW (reprint author), UNIV CALIF BERKELEY,LAWRENCE BERKELEY LAB,DIV MAT SCI,BERKELEY,CA 94720, USA. NR 18 TC 5 Z9 5 U1 1 U2 2 PU ELSEVIER SCIENCE SA LAUSANNE PI LAUSANNE 1 PA PO BOX 564, 1001 LAUSANNE 1, SWITZERLAND SN 0040-6090 J9 THIN SOLID FILMS JI Thin Solid Films PD DEC 15 PY 1994 VL 253 IS 1-2 BP 490 EP 495 DI 10.1016/0040-6090(94)90372-7 PG 6 WC Materials Science, Multidisciplinary; Materials Science, Coatings & Films; Physics, Applied; Physics, Condensed Matter SC Materials Science; Physics GA PX356 UT WOS:A1994PX35600089 ER PT J AU LOVEJOY, ML ZOLPER, JC SHERWIN, ME BACA, AG SHUL, RJ RIEGER, DJ KLEM, JF AF LOVEJOY, ML ZOLPER, JC SHERWIN, ME BACA, AG SHUL, RJ RIEGER, DJ KLEM, JF TI NONALLOYED, REFRACTORY-METAL CONTACT OPTIMIZATION WITH SHALLOW IMPLANTATIONS OF ZN AND MG SO THIN SOLID FILMS LA English DT Article DE CONTACTS; GALLIUM ARSENIDE; ION IMPLANTATION; ZINC ID GAAS; TRANSISTORS AB Refractory metal contacts to GaAs show great promise for stability during high temperature processing and for high reliabiltiy. In this paper, we report on a study of sputtered W and W-Si contacts to ion-implanted p-GaAs with both Zn and Mg implantations. This study focused on refractory contacts to shallow implanted contact layers that are suitable for devices such as junction field effect transistors and heterojunction bipolar transistors. The very different energy loss mechanisms of Zn and Mg ions result in different levels of implant damage, which is studied by varying the annealing temperatures and measuring the effects on contact and sheet resistances with the transmission line method. For the fabrication schemes investigated, the specific contact resistivity vs. annealing temperature values with implant doses from 1 x 10(14) to 5 x 10(15) cm(-2) are found to vary from non-ohmic to 10(-7) Omega cm(2). Low resistance contacts to shallow ( < 800 Angstrom) implanted layers are achieved. RP LOVEJOY, ML (reprint author), SANDIA NATL LABS,COMPOUND SEMICOND RES LAB,POB 5800,ALBUQUERQUE,NM 87185, USA. NR 10 TC 1 Z9 1 U1 1 U2 1 PU ELSEVIER SCIENCE SA LAUSANNE PI LAUSANNE 1 PA PO BOX 564, 1001 LAUSANNE 1, SWITZERLAND SN 0040-6090 J9 THIN SOLID FILMS JI Thin Solid Films PD DEC 15 PY 1994 VL 253 IS 1-2 BP 496 EP 500 DI 10.1016/0040-6090(94)90373-5 PG 5 WC Materials Science, Multidisciplinary; Materials Science, Coatings & Films; Physics, Applied; Physics, Condensed Matter SC Materials Science; Physics GA PX356 UT WOS:A1994PX35600090 ER PT J AU CZAPSKI, G HOLCMAN, J BIELSKI, BHJ AF CZAPSKI, G HOLCMAN, J BIELSKI, BHJ TI REACTIVITY OF NITRIC-OXIDE WITH SIMPLE SHORT-LIVED RADICALS IN AQUEOUS-SOLUTIONS SO JOURNAL OF THE AMERICAN CHEMICAL SOCIETY LA English DT Article ID PULSE RADIOLYSIS; NO; SUPEROXIDE AB The kinetic parameters and spectral properties of the products of the reaction of nitric oxide (NO) with (SCN)(2)(-), Br-2(-), CO2-, CO3-., and ethyl alcohol radicals were studied by the pulse radiolysis technique. The rate constants for the reaction of NO with these radicals are k[NO + (SCN)(2)(-)] = (4.3 +/- 0.1) x 10(9) M(-1) s(-1), k[NO + CO2-] = (2.9 +/- 0.5) x 10(9) M(-1) s(-1), k[NO + CO3-.] = (3.5 +/- 0.5) x 10(9) M(-1) s(-1), and k[NO + ethanol radicals] = (3.0 +/- 1.0) x 10(9) M(-1) s(-1). (SCN)(2)(-) radical forms an adduct that decomposes by first-order processes to yield ultimately NO2-. The CO3-. radical reacts with NO by O- transfer with the direct formation of NO2-. The CO2- radical reacts with NO forming the NOCO2- transient which reacts with excess NO yielding N2O2-. The ethanol radical-NO adducts rearrange to yield ultimately oximes/hydroxamic acids. Preliminary studies of the reaction of NO with Br-2(-) shaw that, while NOBr2- is formed at a rate similar to that of NO(SCN)(2)(-), k(NO + Br-2(-)) = (4.8 +/- 0.4) x 10(9) M(-1) s(-1)), the corresponding NOBr transient decays by a very complex mechanism that is currently being studied in greater detail. Mechanisms by which the various NO-adducts decay are discussed. C1 BROOKHAVEN NATL LAB,DEPT CHEM,UPTON,NY 11973. HEBREW UNIV JERUSALEM,DEPT CHEM,IL-91904 JERUSALEM,ISRAEL. NR 25 TC 62 Z9 62 U1 0 U2 4 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 SN 0002-7863 J9 J AM CHEM SOC JI J. Am. Chem. Soc. PD DEC 14 PY 1994 VL 116 IS 25 BP 11465 EP 11469 DI 10.1021/ja00104a028 PG 5 WC Chemistry, Multidisciplinary SC Chemistry GA PX386 UT WOS:A1994PX38600028 ER PT J AU ZHONG, CJ PORTER, MD AF ZHONG, CJ PORTER, MD TI EVIDENCE FOR CARBON SULFUR BOND-CLEAVAGE IN SPONTANEOUSLY ADSORBED ORGANOSULFIDE-BASED MONOLAYERS AT GOLD SO JOURNAL OF THE AMERICAN CHEMICAL SOCIETY LA English DT Note ID METAL-SURFACES; ELECTRODES; SPECTROSCOPY; DIFFRACTION; DESORPTION; THIOPHENOL; ADSORPTION; SILVER; FILMS; AU C1 IOWA STATE UNIV SCI & TECHNOL,US DOE,AMES LAB,AMES,IA 50011. IOWA STATE UNIV SCI & TECHNOL,DEPT CHEM,AMES,IA 50011. RI Zhong, Chuan-Jian/D-3394-2013 NR 33 TC 161 Z9 164 U1 0 U2 10 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 SN 0002-7863 J9 J AM CHEM SOC JI J. Am. Chem. Soc. PD DEC 14 PY 1994 VL 116 IS 25 BP 11616 EP 11617 DI 10.1021/ja00104a071 PG 2 WC Chemistry, Multidisciplinary SC Chemistry GA PX386 UT WOS:A1994PX38600071 ER PT J AU HUANG, DB CHANG, CH AINSWORTH, C BRUNGER, AT EULITZ, M SOLOMON, A STEVENS, FJ SCHIFFER, M AF HUANG, DB CHANG, CH AINSWORTH, C BRUNGER, AT EULITZ, M SOLOMON, A STEVENS, FJ SCHIFFER, M TI COMPARISON OF CRYSTAL-STRUCTURES OF 2 HOMOLOGOUS PROTEINS - STRUCTURAL ORIGIN OF ALTERED DOMAIN INTERACTIONS IMMUNOGLOBULIN LIGHT-CHAIN DIMERS SO BIOCHEMISTRY LA English DT Article ID BENCE-JONES PROTEIN; 3-DIMENSIONAL STRUCTURE; MOLECULAR-STRUCTURE; SOMATIC MUTATION; VARIABLE DOMAINS; IMMUNE-RESPONSE; HUMAN CD4; RESOLUTION; REFINEMENT; ANTIBODY AB The sequence and structure of a second human kappa(I) immunoglobulin light-chain variable domain, Wat, has been determined. The R-factor is 15.7% for 1.9-Angstrom data. One hundred and ninety-five water molecules were identified; 30 water molecules were located in identical positions in each of the monomers. Some of the water molecules are integral parts of the domains. This light chain is encoded by the same variable domain gene that encoded the previously characterized kappa(I) variable domain, Rei. Due to limited somatic mutation, the two highly homologous proteins differ in only 20 of the 108 residues. Wat crystallized in space group P6(4) while Rei crystallized in space group P6(1); in both crystals, the asymmetric unit was the noncovalent dimer. Although the basic domain structure is the same for both proteins, the relative positions of the domains within the two dimers differ. This difference is most likely accounted for by the replacement of Tyr36 in Rei by Phe in the Wat protein. Residue Tyr36 is part of the hydrogen-bonding network in the interface between the domains in Rei. Losing the hydrogen-bonding capability of residue 36 by replacement of Tyr by Phe alters the network of hydrogen bonds between the domains, resulting in a different domain-domain contact. The details of lattice contacts in the two crystals were compared. One type of contact that extends the beta-sheet of the individual domains was conserved, but because it involved different symmetry elements within the crystal, different crystal packing resulted. In the Wat crystal, one of the contacts shows an example of how a symmetrical binding site can ''bind'' an asymmetrical object. Further, the examination of the Wat crystal also illustrates how the different crystalline environments of the domains of the dimer results in different distributions of temperature factors for the residues within the domains. C1 ARGONNE NATL LAB,CTR MECHANIST BIOL & BIOTECHNOL,ARGONNE,IL 60439. YALE UNIV,DEPT MOLEC BIOPHYS & BIOCHEM,NEW HAVEN,CT. YALE UNIV,HOWARD HUGHES MED INST,NEW HAVEN,CT 06511. GESELL SCHWERIONENFORSCH MBH,INST CLIN MOLEC BIOL,MUNICH 70,GERMANY. UNIV TENNESSEE,MED CTR,GRAD SCH MED,DEPT MED,HUMAN IMMUNOL & CANC PROGRAM,KNOXVILLE,TN 37920. FU NCI NIH HHS [CA 10056]; NCRR NIH HHS [1 P41 RR06009]; NIDDK NIH HHS [DK43757] NR 41 TC 37 Z9 38 U1 0 U2 1 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 SN 0006-2960 J9 BIOCHEMISTRY-US JI Biochemistry PD DEC 13 PY 1994 VL 33 IS 49 BP 14848 EP 14857 DI 10.1021/bi00253a024 PG 10 WC Biochemistry & Molecular Biology SC Biochemistry & Molecular Biology GA PW706 UT WOS:A1994PW70600024 PM 7993911 ER PT J AU HUNN, JD WITHROW, SP WHITE, CW CLAUSING, RE HEATHERLY, L CHRISTENSEN, CP AF HUNN, JD WITHROW, SP WHITE, CW CLAUSING, RE HEATHERLY, L CHRISTENSEN, CP TI FABRICATION OF SINGLE-CRYSTAL DIAMOND MICROCOMPONENTS SO APPLIED PHYSICS LETTERS LA English DT Article ID FILMS C1 POTOMAC PHOTON,LANHAM,MD 20705. RP HUNN, JD (reprint author), OAK RIDGE NATL LAB,BLDG 5500 MS-6376,OAK RIDGE,TN 37831, USA. NR 14 TC 23 Z9 23 U1 0 U2 8 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 DEC 12 PY 1994 VL 65 IS 24 BP 3072 EP 3074 DI 10.1063/1.112959 PG 3 WC Physics, Applied SC Physics GA PX057 UT WOS:A1994PX05700012 ER PT J AU DINH, LN CHASE, LL BALOOCH, M TERMINELLO, LJ WOOTEN, F AF DINH, LN CHASE, LL BALOOCH, M TERMINELLO, LJ WOOTEN, F TI PHOTOLUMINESCENCE OF OXIDIZED SILICON NANOCLUSTERS DEPOSITED ON THE BASAL-PLANE OF GRAPHITE SO APPLIED PHYSICS LETTERS LA English DT Article ID LIGHT-EMISSION; POROUS SILICON; OXIDE C1 LAWRENCE LIVERMORE NATL LAB,DEPT APPL SCI,LIVERMORE,CA 94551. RP DINH, LN (reprint author), LAWRENCE LIVERMORE NATL LAB,DEPT CHEM & MAT SCI,LIVERMORE,CA 94551, USA. NR 15 TC 42 Z9 43 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 DEC 12 PY 1994 VL 65 IS 24 BP 3111 EP 3113 DI 10.1063/1.112452 PG 3 WC Physics, Applied SC Physics GA PX057 UT WOS:A1994PX05700025 ER PT J AU HEINEMANN, H AF HEINEMANN, H TI CATALYST PERFORMANCE TESTING SO CATALYSIS TODAY LA English DT Article RP HEINEMANN, H (reprint author), UNIV CALIF BERKELEY,LAWRENCE BERKELEY LAB,BLDG 66-421,BERKELEY,CA 94720, USA. NR 25 TC 1 Z9 1 U1 0 U2 0 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0920-5861 J9 CATAL TODAY JI Catal. Today PD DEC 12 PY 1994 VL 22 IS 2 BP 281 EP 293 DI 10.1016/0920-5861(94)80105-3 PG 13 WC Chemistry, Applied; Chemistry, Physical; Engineering, Chemical SC Chemistry; Engineering GA QA472 UT WOS:A1994QA47200007 ER PT J AU SZPAK, S MOSIERBOSS, PA SMITH, JJ AF SZPAK, S MOSIERBOSS, PA SMITH, JJ TI DEUTERIUM UPTAKE DURING PD-D CODEPOSITION SO JOURNAL OF ELECTROANALYTICAL CHEMISTRY LA English DT Article DE GALVANOSTATIC PERTURBATION; DEUTERIUM UPTAKE; PD-D CODEPOSITION ID HYDROGEN AB The mode of deuterium uptake during Pd-D co-deposition has been explored using galvanostatic perturbation techniques. The resultant potential relaxation curves exhibit four distinct potential-time intervals where the relaxation process is controlled by the interaction between the transport of deuterium from the lattice to the surface to form adsorbed deuterium and the reduction of palladium from solution. These interactions are discussed in terms of the palladium + electrolyte interphase. C1 US DOE,WASHINGTON,DC 20585. RP SZPAK, S (reprint author), USN,CTR NAVAL COMMAND CONTROL & OCEAN SURVEILLENCE,DIV RDT&E,SAN DIEGO,CA 92152, USA. NR 13 TC 9 Z9 9 U1 0 U2 0 PU ELSEVIER SCIENCE SA LAUSANNE PI LAUSANNE 1 PA PO BOX 564, 1001 LAUSANNE 1, SWITZERLAND SN 0022-0728 J9 J ELECTROANAL CHEM JI J. Electroanal. Chem. PD DEC 12 PY 1994 VL 379 IS 1-2 BP 121 EP 127 DI 10.1016/0022-0728(94)87130-2 PG 7 WC Chemistry, Analytical; Electrochemistry SC Chemistry; Electrochemistry GA PX037 UT WOS:A1994PX03700012 ER PT J AU COEN, S AF COEN, S TI WHITE HOLES IN THE FRESNEL ZONE CAUSING AMBIGUOUS FIRST ARRIVAL TIME TOMOGRAPHY INTERPRETATION SO PHYSICAL REVIEW LETTERS LA English DT Article ID NONLINEAR TRAVELTIME TOMOGRAPHY C1 UNIV CALIF BERKELEY,LAWRENCE BERKELEY LAB,CCS,BERKELEY,CA 94720. RP COEN, S (reprint author), GEOFRONTS INC,POB 7038,BERKELEY,CA 94707, USA. NR 9 TC 5 Z9 5 U1 0 U2 0 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 0031-9007 J9 PHYS REV LETT JI Phys. Rev. Lett. PD DEC 12 PY 1994 VL 73 IS 24 BP 3219 EP 3222 DI 10.1103/PhysRevLett.73.3219 PG 4 WC Physics, Multidisciplinary SC Physics GA PW978 UT WOS:A1994PW97800010 ER PT J AU GULACSI, Z GULACSI, M AF GULACSI, Z GULACSI, M TI EXACT SOLUTION FOR A CHAIN-LIKE CLUSTER GROWTH-MODEL SO PHYSICAL REVIEW LETTERS LA English DT Article ID GAS-PHASE; CARBON; IONS; FULLERENES; RINGS; ATOMS C1 LOS ALAMOS NATL LAB,DIV THEORET,LOS ALAMOS,NM 87545. RP GULACSI, Z (reprint author), LAJOS KOSSUTH UNIV,DEPT THEORET PHYS,POB 5,H-4010 DEBRECEN,HUNGARY. RI Gulacsi, Zsolt/A-3829-2013; OI Gulacsi, Zsolt/0000-0002-2349-7166 NR 30 TC 12 Z9 12 U1 0 U2 1 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 0031-9007 J9 PHYS REV LETT JI Phys. Rev. Lett. PD DEC 12 PY 1994 VL 73 IS 24 BP 3239 EP 3242 DI 10.1103/PhysRevLett.73.3239 PG 4 WC Physics, Multidisciplinary SC Physics GA PW978 UT WOS:A1994PW97800015 ER PT J AU KING, DM SHEN, ZX DESSAU, DS MARSHALL, DS PARK, CH SPICER, WE PENG, JL LI, ZY GREENE, RL AF KING, DM SHEN, ZX DESSAU, DS MARSHALL, DS PARK, CH SPICER, WE PENG, JL LI, ZY GREENE, RL TI OBSERVATION OF A SADDLE-POINT SINGULARITY IN BI-2(SR0.97PR0.03)(2)CUO6+DELTA AND ITS IMPLICATIONS FOR NORMAL AND SUPERCONDUCTING STATE PROPERTIES SO PHYSICAL REVIEW LETTERS LA English DT Article ID VANHOVE SINGULARITIES; FERMI-SURFACE; ELECTRONIC-STRUCTURE; HIGH-TC; TRANSITION; OXIDES C1 STANFORD UNIV,STANFORD ELECTR LABS,STANFORD,CA 94305. STANFORD UNIV,STANFORD SYNCHROTRON RADIAT LAB,STANFORD,CA 94305. STANFORD UNIV,DEPT APPL PHYS,STANFORD,CA 94305. UNIV MARYLAND,DEPT PHYS,CTR SUPERCONDUCT RES,COLLEGE PK,MD 20742. NR 24 TC 191 Z9 191 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 DEC 12 PY 1994 VL 73 IS 24 BP 3298 EP 3301 DI 10.1103/PhysRevLett.73.3298 PG 4 WC Physics, Multidisciplinary SC Physics GA PW978 UT WOS:A1994PW97800030 ER PT J AU GOFRON, K CAMPUZANO, JC ABRIKOSOV, AA LINDROOS, M BANSIL, A DING, H KOELLING, D DABROWSKI, B AF GOFRON, K CAMPUZANO, JC ABRIKOSOV, AA LINDROOS, M BANSIL, A DING, H KOELLING, D DABROWSKI, B TI OBSERVATION OF AN EXTENDED VAN-HOVE SINGULARITY IN YBA2CU4O8 BY ULTRAHIGH-ENERGY RESOLUTION ANGLE-RESOLVED PHOTOEMISSION SO PHYSICAL REVIEW LETTERS LA English DT Article ID FERMI-SURFACE; ELECTRONIC-STRUCTURE; BAND-STRUCTURE; SUPERCONDUCTIVITY; YBA2CU3O6.9 C1 UNIV ILLINOIS,DEPT PHYS,CHICAGO,IL 60607. NORTHEASTERN UNIV,DEPT PHYS,BOSTON,MA 02115. TAMPERE UNIV TECHNOL,DEPT PHYS,TAMPERE,FINLAND. NO ILLINOIS UNIV,DEPT PHYS,DE KALB,IL 60115. RP GOFRON, K (reprint author), ARGONNE NATL LAB,9700 S CASS AVE,ARGONNE,IL 60439, USA. RI Campuzano, Juan Carlos/G-4358-2012; OI Ding, Hong/0000-0003-4422-9248 NR 27 TC 346 Z9 349 U1 2 U2 17 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 DEC 12 PY 1994 VL 73 IS 24 BP 3302 EP 3305 DI 10.1103/PhysRevLett.73.3302 PG 4 WC Physics, Multidisciplinary SC Physics GA PW978 UT WOS:A1994PW97800031 ER PT J AU SCHRIESHEIM, A AF SCHRIESHEIM, A TI UNITED-STATES SCIENCE CONFRONTS A NEW UNCERTAINTY PRINCIPLE SO SCIENTIST LA English DT Editorial Material AB Much as the Heisenberg Uncertainty Principle revealed the difficulty of forecasting the position and momentum of subatomic particles, scientists and research administrators are struggling to find direction amid the intersection of societal goals, politics, and the scientific merits of the national research enterprise, asserts Argonne National Laboratory chief Alan Schriesheim. RP SCHRIESHEIM, A (reprint author), ARGONNE NATL LAB,ARGONNE,IL 60439, USA. NR 3 TC 0 Z9 0 U1 0 U2 0 PU SCIENTIST INC PI PHILADELPHIA PA 3600 MARKET ST SUITE 450, PHILADELPHIA, PA 19104 SN 0890-3670 J9 SCIENTIST JI Scientist PD DEC 12 PY 1994 VL 8 IS 24 BP 12 EP 12 PG 1 WC Information Science & Library Science; Multidisciplinary Sciences SC Information Science & Library Science; Science & Technology - Other Topics GA PW057 UT WOS:A1994PW05700007 ER PT J AU MARSCH, GA WARD, RL COLVIN, M TURTELTAUB, KW AF MARSCH, GA WARD, RL COLVIN, M TURTELTAUB, KW TI NONCOVALENT DNA GROOVE-BINDING BY 2-AMINO-1-METHYL-6-PHENYLIMIDAZO[4,5-B]PYRIDINE SO NUCLEIC ACIDS RESEARCH LA English DT Article ID HETEROCYCLIC AROMATIC-AMINES; NUCLEIC ACID INTERACTIONS; FOOD MUTAGEN; COOKED-BEEF; MOLECULAR RECOGNITION; EQUILIBRIUM BINDING; PHYSICAL BINDING; PYRIDINE PHIP; BASE-SEQUENCE; ACTINOMYCIN-D AB The cooked meat mutagen 2-amino-1-methyl-6-phenyl-imidazo[4,5-b]pyridine (PhIP) is metabolized in vivo to electrophilic intermediates that covalently bind to DNA guanines. Here we address the mechanism of PhIP's non-covalent interaction with DNA by using spectroscopic and computational methodologies. NMR methodologies indicated that upon addition of DNA, PhIP aromatic protons underwent a small, 0.11-0.12 p.p.m. upfield shift. DNA phosphorus resonances of noncovalent PhIP-DNA complexes broadened and slightly shifted upfield, while DNA base imino proton resonances shifted slightly downfield relative to DNA alone. UV and fluorescence spectra of PhIP titrated with DNA showed no detectable shifting and hypochromism of absorbance or fluorescence bands. In the presence of DNA, PhIP fluorescence was efficiently quenched by acrylamide, but not by silver ion. Further, the NMR spectra suggest that PhIP is in fast exchange with the DNA, and is slightly specific for adenine-thymine (A-T) sequences. Finally, structural arguments based on quantum chemistry calculations suggested that PhIP and its metabolites are unlikely to intercalate into DNA. These data collectively indicate that PhIP noncovalently binds in a groove of DNA. C1 LAWRENCE LIVERMORE NATL LAB,BIOL & BIOTECHNOL RES PROGRAM,LIVERMORE,CA 94551. LAWRENCE LIVERMORE NATL LAB,DEPT CHEM & MAT SCI,LIVERMORE,CA 94551. SANDIA NATL LABS,DEPT COMPUTAT ENGN,LIVERMORE,CA 94551. FU NCI NIH HHS [CA55861] NR 64 TC 13 Z9 13 U1 0 U2 3 PU OXFORD UNIV PRESS UNITED KINGDOM PI OXFORD PA WALTON ST JOURNALS DEPT, OXFORD, ENGLAND OX2 6DP SN 0305-1048 J9 NUCLEIC ACIDS RES JI Nucleic Acids Res. PD DEC 11 PY 1994 VL 22 IS 24 BP 5408 EP 5415 DI 10.1093/nar/22.24.5408 PG 8 WC Biochemistry & Molecular Biology SC Biochemistry & Molecular Biology GA PZ487 UT WOS:A1994PZ48700038 PM 7816632 ER PT J AU SCHELL, WR BERG, MT MYTTENAERE, C MASSEY, CD AF SCHELL, WR BERG, MT MYTTENAERE, C MASSEY, CD TI A REVIEW OF THE DEPOSITION AND UPTAKE OF STABLE AND RADIOACTIVE ELEMENTS IN FORESTS AND OTHER NATURAL ECOSYSTEMS FOR USE IN PREDICTIVE MODELING SO SCIENCE OF THE TOTAL ENVIRONMENT LA English DT Article DE FOREST; RADIONUCLIDE; RESIDENCE TIME; MODELING; RISK ID ATMOSPHERIC DEPOSITION; METALS AB To understand the behavior of radionuclides in forests, we require information on the processes which govern the interaction of elements in these ecosystems. The basic questions we ask are: (1) What is the residence time of any element in a forest? (2) What are the dominant rate determining processes responsible for uptake? (3) What are the important radionuclide pathways through the forest to man? (4) How long does the contamination remain a risk to man? (5) What chemical complexing species are responsible for element uptake by the roots. Such questions must be answered to define better the processes which are responsible for the distribution and fate of trace elements and radionuclides in forest and natural ecosystems, and to develop predictive models for radiological assessment purposes. C1 W VIRGINIA UNIV,DEPT IND ENGN,MORGANTOWN,WV 26506. UNIV CATHOLIQUE LOUVAIN,BIOL VEGETALE LAB,B-1348 LOUVAIN,BELGIUM. SANDIA NATL LABS,DIV RADIOACT & MIXED WASTE MANAGEMENT,ALBUQUERQUE,NM 87185. RP SCHELL, WR (reprint author), UNIV PITTSBURGH,DEPT ENVIRONM & OCCUPAT HLTH,PITTSBURGH,PA 15260, USA. NR 20 TC 3 Z9 3 U1 1 U2 3 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 DEC 11 PY 1994 VL 157 IS 1-3 BP 153 EP 161 PG 9 WC Environmental Sciences SC Environmental Sciences & Ecology GA QA245 UT WOS:A1994QA24500019 ER PT J AU SMOOT, GF TENORIO, L BANDAY, AJ KOGUT, A WRIGHT, EL HINSHAW, G BENNETT, CL AF SMOOT, GF TENORIO, L BANDAY, AJ KOGUT, A WRIGHT, EL HINSHAW, G BENNETT, CL TI STATISTICS AND TOPOLOGY OF THE COBE DIFFERENTIAL MICROWAVE RADIOMETER FIRST-YEAR SKY MAPS SO ASTROPHYSICAL JOURNAL LA English DT Article DE COSMIC MICROWAVE BACKGROUND; COSMOLOGY, OBSERVATIONS; LARGE-SCALE STRUCTURE OF UNIVERSE; METHODS, STATISTICAL ID INFLATIONARY UNIVERSE; COSMIC STRUCTURE; FLUCTUATIONS; PERTURBATIONS; ANISOTROPY; TEXTURE AB We use statistical and topological quantities to test the COBE DMR first-year sky maps against the hypothesis that the observed temperature fluctuations reflect Gaussian initial density perturbations with random phases. Recent papers discuss specific quantities as discriminators between Gaussian and non-Gaussian behavior, but the treatment of instrumental noise on the data is largely ignored. The presence of noise in the data biases many statistical quantities in a manner dependent on both the noise properties and the unknown cosmic microwave background temperature field. Appropriate weighting schemes can minimize this effect, but it cannot be completely eliminated. Analytic expressions are presented for these biases, and Monte Carlo simulations are used to assess the best strategy for determining cosmologically interesting information from noisy data. The genus is a robust discriminator that can be used to estimate the power-law quadrupole-normalized amplitude, Q(rms-PS) independently of the two-point correlation function. The genus of the DMR data is consistent with Gaussian initial fluctuations with Q(rms-PS) = (15.7 +/- 2.2) - (6.6 +/- 0.3)(n - 1) mu K, where n is the power-law index. Fitting the rms temperature variations at various smoothing angles gives Q(rms-PS) = 13.2 +/- 2.5 mu K and n = 1.7(-0.6)(+0.3). While consistent with Gaussian fluctuations, the first year data are only sufficient to rule out strongly non-Gaussian distributions of fluctuations. C1 UNIV CALIF BERKELEY,CTR PARTICLE ASTROPHYS,BERKELEY,CA 94720. NASA,GODDARD SPACE FLIGHT CTR,UNIV SPACE RES ASSOC,GREENBELT,MD 20771. NASA,GODDARD SPACE FLIGHT CTR,HUGHES STX CORP,GREENBELT,MD 20771. UNIV CALIF LOS ANGELES,DEPT ASTRON,LOS ANGELES,CA 90024. RP SMOOT, GF (reprint author), UNIV CALIF BERKELEY,LAWRENCE BERKELEY LAB,SPACE SCI LAB,BLDG 50-351,BERKELEY,CA 94720, USA. RI Kogut, Alan/D-6293-2012 NR 43 TC 58 Z9 58 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 DEC 10 PY 1994 VL 437 IS 1 BP 1 EP 11 DI 10.1086/174970 PN 1 PG 11 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA PW003 UT WOS:A1994PW00300001 ER PT J AU DICKEL, HR AUER, LH AF DICKEL, HR AUER, LH TI MODELING RADIATIVE-TRANSFER IN MOLECULAR CLOUDS .1. HCO+ IN THE STAR-FORMING REGION W49A NORTH SO ASTROPHYSICAL JOURNAL LA English DT Article DE H II REGIONS; ISM, CLOUDS; ISM, INDIVIDUAL (W49); ISM, MOLECULES RADIATIVE TRANSFER ID ROTATIONAL-EXCITATION; LINE; SUBMILLIMETER; COLLAPSE; CORE; FRAGMENTATION; KINEMATICS; EMISSION AB A new general multilevel, non-LTE radiative transfer code, valid for any velocity field, is applied to HCO+ observations of W49A North. Three classes of collapse models are considered: free-fall collapse (v proportional to 1/root r), homologous collapse (v proportional to r), and ''inside-out'' collapse (Shu 1977). A simple free-fall collapse model, with rho proportional to r(-3/2) throughout the molecular cloud, successfully reproduces the features of the observations and gives peer the best fit to the J = 1-0 and J = 3-2 profiles both toward the prominent H II component G of W49A North and off the center. In addition to a slow radial fall-off of density, the theoretical modeling implies the following for the molecular cloud: the large line widths result from motions occurring within the inner 1 pc, and there are probably one or more fragments with peculiar velocities within this same region. C1 LOS ALAMOS NATL LAB, EARTH & ENVIRONM SCI 5, MS-F665, LOS ALAMOS, NM 87545 USA. RP DICKEL, HR (reprint author), UNIV ILLINOIS, DEPT ASTRON, 1002 W GREEN ST, 103 ASTRON BLDG, URBANA, IL 61801 USA. NR 34 TC 20 Z9 21 U1 0 U2 0 PU IOP PUBLISHING LTD PI BRISTOL PA DIRAC HOUSE, TEMPLE BACK, BRISTOL BS1 6BE, ENGLAND SN 0004-637X J9 ASTROPHYS J JI Astrophys. J. PD DEC 10 PY 1994 VL 437 IS 1 BP 222 EP 238 DI 10.1086/174991 PN 1 PG 17 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA PW003 UT WOS:A1994PW00300022 ER PT J AU CLOUTMAN, LD AF CLOUTMAN, LD TI ENSEMBLE-AVERAGED THERMONUCLEAR REACTION-RATES FOR TURBULENT CONVECTION IN STELLAR INTERIORS SO ASTROPHYSICAL JOURNAL LA English DT Article DE CONVECTION; NUCLEAR REACTIONS, NUCLEOSYNTHESIS, ABUNDANCES; STARS, INTERIORS; SUPERNOVAE, GENERAL; TURBULENCE ID 3-DIMENSIONAL NUMERICAL SIMULATIONS; MIXING-LENGTH THEORY; CORE HELIUM FLASH; PROBABILITY-DISTRIBUTIONS; FLOWS; STARS; MODEL; TIME; DIFFUSION; SHELLS AB It is well known in combustion research that the interaction between turbulence and chemistry can substantially modify flame speeds and overall fuel consumption rates compared to the laminar values. An analogous effect exists for thermonuclear reaction rates in turbulent convection zones in stellar interiors. We describe a parametric study that estimates the modification of ensemble-averaged thermonuclear reaction rates by turbulence. The basic approach is to assume some parametric form for the joint probability density function for the reaction variables, estimate the values of the parameters, and then perform the necessary integration to get the averaged reaction rate. We conclude that the effect is not likely to be important during quiescent core-burning phases. The effect is likely to be important for explosive events such as the core helium flash, novae, and supernovae. However, accurate calculation of the turbulent reaction rates must await a reliable quantitative theory of stellar convection. RP CLOUTMAN, LD (reprint author), LAWRENCE LIVERMORE NATL LAB,POB 808,L-298,LIVERMORE,CA 94550, USA. NR 52 TC 0 Z9 0 U1 0 U2 0 PU UNIV CHICAGO PRESS PI CHICAGO PA 5720 S WOODLAWN AVE, CHICAGO, IL 60637 SN 0004-637X J9 ASTROPHYS J JI Astrophys. J. PD DEC 10 PY 1994 VL 437 IS 1 BP 384 EP 395 DI 10.1086/175003 PN 1 PG 12 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA PW003 UT WOS:A1994PW00300034 ER PT J AU GAZTANAGA, E FRIEMAN, JA AF GAZTANAGA, E FRIEMAN, JA TI BIAS AND HIGH-ORDER GALAXY CORRELATION-FUNCTIONS IN THE APM GALAXY SURVEY SO ASTROPHYSICAL JOURNAL LA English DT Article DE GALAXIES, CLUSTERING; LARGE-SCALE STRUCTURE OF UNIVERSE ID LARGE-SCALE STRUCTURE; STATISTICS; UNIVERSE; GRAVITY AB On large scales, the higher order moments of the mass distribution, S-J = ($) over bar xi(J)/($) over bar xi(2)(J-1), e.g., the skewness S-3 and kurtosis S-4, can be predicted using nonlinear perturbation theory. Comparison of these predictions with moments of the observed galaxy distribution probes the bias between galaxies and mass. Applying this method to models with initially Gaussian fluctuations and power spectra P(k) similar to that of galaxies in the Automatic Plate Measuring (APM) survey, we find that the predicted higher order moments S-J(R) are in good agreement with those directly inferred from the APM survey in the absence of bias. We use this result to place limits on the linear and nonlinear bias parameters. Models in which the extra power observed on large scales (with respect to the standard cold dark matter [CDM] model) is produced by scale-dependent bias match the APM higher order amplitudes only if nonlinear bias (rather than nonlinear gravity) generates the observed higher order moments. When normalized to COBE DMR, these models are significantly ruled out by the S-3 observations. The cold plus hot dark matter model normalized to COBE can reproduce the APM higher order correlations if one introduces nonlinear bias terms, while the low-density CDM model with a cosmological constant does not require any bias to fit the large-scale amplitudes. C1 FERMILAB NATL ACCELERATOR LAB,NASA,FERMILAB ASTROPHYS CTR,BATAVIA,IL 60510. UNIV CHICAGO,DEPT ASTRON & ASTROPHYS,CHICAGO,IL 60637. RP GAZTANAGA, E (reprint author), UNIV OXFORD,DEPT PHYS & ASTRON,NUCL & ASTROPHYS LAB,KEBLE RD,OXFORD OX1 3RH,ENGLAND. NR 24 TC 76 Z9 78 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 DEC 10 PY 1994 VL 437 IS 1 BP L13 EP L16 DI 10.1086/187671 PN 2 PG 4 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA PW004 UT WOS:A1994PW00400004 ER PT J AU VERDONCK, D ZANDT, G AF VERDONCK, D ZANDT, G TI 3-DIMENSIONAL CRUSTAL STRUCTURE OF THE MENDOCINO TRIPLE JUNCTION REGION FROM LOCAL EARTHQUAKE TRAVEL-TIMES SO JOURNAL OF GEOPHYSICAL RESEARCH-SOLID EARTH LA English DT Article ID SAN-ANDREAS FAULT; CASCADIA SUBDUCTION ZONE; NORTHERN CALIFORNIA; VELOCITY STRUCTURE; CAPE MENDOCINO; GORDA PLATE; NORTHWESTERN CALIFORNIA; NORTHEASTERN CALIFORNIA; TECTONIC HISTORY; ARRIVAL TIMES AB The large-scale, three-dimensional geometry of the Mendocino Triple Junction at Cape Mendocino, California, was investigated by inverting nearly 19,000 P wave arrival times from over 1400 local earthquakes to estimate the three-dimensional velocity structure and hypocentral parameters. A velocity grid 175 km (N-S) by 125 km (E-W) centered near Garberville, California, was constructed with 25 km horizontal and 5 km vertical node spacing, The model was well resolved near Cape Mendocino, where the earthquakes and stations are concentrated. At about 40.6 degrees N latitude a high-velocity gradient between 6.5 and 7.5 km/s dips gently to the south and east from about 15 km depth near the coast. Relocated hypocenters concentrate below this high gradient which we interpret as the oceanic crust of the subducted Gorda Plate. Therefore the depth to the top of the Gorda Plate near Cape Mendocino is interpreted to be similar to 15 km, The Gorda Plate appears intact and dipping similar to 8 degrees eastward due to subduction and flexing downward 6 degrees-12 degrees to the south. Both hypocenters and velocity structure suggest that the southern edge of the plate intersects the coastline at 40.3 degrees N latitude and maintains a linear trend 15 degrees south of east to at least 123 degrees W longitude. The top of a large low-velocity region at 20-30 km depth extends about 50 km N-S and 75 km E-W (roughly between Gatberville and Covelo) and is located above and south of the southern edge of the Gorda Plate, We interpret this low velocity area to be locally thickened crust (8-10 km) due to either local compressional forces associated with north-south compression caused by the northward impingement of the rigid Pacific Plate or by underthrusting of the base of the ascretionary subduction complex at the southern terminous of the Cascadia Subduction Zone. South of Cape Mendocino and southwest of the Garberville fault, high velocities indicative of oceanic crust are detected at 15 km depth, We interpret this evidence as tectonic underplating of the Pacific oceanic crust beneath the coastal Franciscan Complex, similar to the situation seismically imaged in central coastal California (Page and Brocher, 1994). This geometry indicates that the westernmost portion of the slab window has been filled by tectonic underplating and crustal thickening, while deep-seated mantle upwelling is confined to an area centered about 75 km north of Clear Lake (Bent et al, 1992; Zandt et al., 1992). C1 LAWRENCE LIVERMORE NATL LAB, DEPT EARTH SCI, DIV EARTH SCI, LIVERMORE, CA 94550 USA. LAWRENCE LIVERMORE NATL LAB, INST GEOPHYS & PLANETARY PHYS, LIVERMORE, CA 94550 USA. NR 66 TC 26 Z9 26 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 DEC 10 PY 1994 VL 99 IS B12 BP 23843 EP 23858 DI 10.1029/94JB01238 PG 16 WC Geochemistry & Geophysics SC Geochemistry & Geophysics GA PX338 UT WOS:A1994PX33800006 ER PT J AU MCCALL, KR GUYER, RA AF MCCALL, KR GUYER, RA TI EQUATION OF STATE AND WAVE-PROPAGATION IN HYSTERETIC NONLINEAR ELASTIC-MATERIALS SO JOURNAL OF GEOPHYSICAL RESEARCH-SOLID EARTH LA English DT Article ID MODELS AB Heterogeneous materials, such as rock, have extreme nonlinear elastic behavior (the coefficient characterizing cubic anharmonicity is orders of magnitude greater than that of homogeneous materials) and striking hysteretic behavior (the stress-strain equation of state has discrete memory). A model of these materials, taking their macroscopic elastic properties to result from many mesoscopic hysteretic elastic units, is developed. The Preisach-Mayergoyz description of hysteretic systems and effective medium theory are combined to find the quasistatic stress-strain equation of state; the quasistatic modulus-stress relationship, and the dynamic modulus-stress relationship. Hysteresis with discrete memory is inherent in all three relationships. The dynamic modulus-stress relationship is characterized and used as input to the equation of motion for nonlinear elastic wave propagation. This equation of motion is examined for one-dimensional propagation using a Green function method. The out-of-phase component of the dynamic modulus due to hysteresis is found to be responsible for the generation of odd harmonics and to determine the amplitude of the nonlinear attenuation. C1 UNIV MASSACHUSETTS, DEPT PHYS & ASTRON, AMHERST, MA 01003 USA. RP MCCALL, KR (reprint author), LOS ALAMOS NATL LAB, DIV EARTH & ENVIRONM SCI, MAIL STOP F665, LOS ALAMOS, NM 87545 USA. NR 20 TC 146 Z9 176 U1 0 U2 16 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 DEC 10 PY 1994 VL 99 IS B12 BP 23887 EP 23897 DI 10.1029/94JB01941 PG 11 WC Geochemistry & Geophysics SC Geochemistry & Geophysics GA PX338 UT WOS:A1994PX33800009 ER PT J AU TAYLOR, EW FEAR, AL BOHM, A KIM, SH KOTHS, K AF TAYLOR, EW FEAR, AL BOHM, A KIM, SH KOTHS, K TI STRUCTURE-FUNCTION STUDIES ON RECOMBINANT HUMAN MACROPHAGE-COLONY-STIMULATING FACTOR (M-CSF) SO JOURNAL OF BIOLOGICAL CHEMISTRY LA English DT Article ID RECEPTOR-BINDING SITE; FACTOR-I; 3-DIMENSIONAL STRUCTURE; HUMAN INTERLEUKIN-6; CRYSTAL-STRUCTURE; GROWTH-FACTORS; EXPRESSION; ACTIVATION; FMS; LOCATION AB Human macrophage colony-stimulating factor (M-CSF) is a homodimeric cytokine that is a member of a structurally related family of hormones defined by an unusual up-up-down-down alpha-helical bundle. To identify regions on the surface of M-CSF that might interact with the M-CSF receptor, single and double amino acid substitutions were introduced into a truncated form of human M-CSF by site directed mutagenesis, and the homodimeric M-CSF analogs were purified and characterized. Certain substitutions in the region before and in helix A and in helix C decreased specific bioactivity and correlated with an approximately equivalent reduction in M-CSF receptor affinity. The most dramatic change was observed in an analog in which residues His-9 and His-15 were replaced with alanines, resulting in a 9,100-fold decrease in specific bioactivity. X-ray crystallographic analysis of this M-CSF alpha H9A,H15A analog at a resolution of 2.5 Angstrom revealed no significant changes in structure other than the expected new side chains at residues 9 and 15. Analogs containing only one of these two histidine substitutions exhibited a decrease in specific bioactivity of 6- and 1200-fold for the H9A and H15A mutations, respectively. It appears that selected amino acids in the NH2-terminal region of M-CSF and possibly portions of the surface formed by helices A and C are significantly involved in interactions with the M-CSF receptor. C1 CHIRON CORP,DEPT BIOL THERAPEUT RES,EMERYVILLE,CA 94608. UNIV CALIF BERKELEY,BIOPHYS GRAD GRP,BERKELEY,CA 94720. UNIV CALIF BERKELEY,LAWRENCE BERKELEY LAB,DIV STRUCT BIOL,BERKELEY,CA 94720. NR 48 TC 21 Z9 22 U1 0 U2 0 PU AMER SOC BIOCHEMISTRY MOLECULAR BIOLOGY INC PI BETHESDA PA 9650 ROCKVILLE PIKE, BETHESDA, MD 20814 SN 0021-9258 J9 J BIOL CHEM JI J. Biol. Chem. PD DEC 9 PY 1994 VL 269 IS 49 BP 31171 EP 31177 PG 7 WC Biochemistry & Molecular Biology SC Biochemistry & Molecular Biology GA PV510 UT WOS:A1994PV51000067 PM 7983059 ER PT J AU CHARTON, F BAILLY, M GUIOCHON, G AF CHARTON, F BAILLY, M GUIOCHON, G TI RECYCLING IN PREPARATIVE LIQUID-CHROMATOGRAPHY SO JOURNAL OF CHROMATOGRAPHY A LA English DT Article ID ELUTION CHROMATOGRAPHY; OPTIMIZATION; ENANTIOMERS; ISOTHERMS; RESOLUTION; CELLULOSE; PROFILES; SILICA; SIZE AB A comparison is made between the performance achieved in preparative chromatography when using elution, the most usual operating mode of this technique, and the different implementations of recycling. This work is based on the experimental results obtained in the separation of the enantiomers of ketoprofen on a cellulose-based stationary phase, using the various chromatographic modes. It uses also the modeling of non-linear chromatography to compare the different operating modes considered. Theoretical and experimental results are presented and compared. In some cases, it is possible to achieve simultaneously both an increase in the production rate and a decrease in the amount of eluent needed. C1 UNIV TENNESSEE,DEPT CHEM,KNOXVILLE,TN 37996. LAB SCI GEN CHIM,F-54001 NANCY,FRANCE. OAK RIDGE NATL LAB,DIV ANALYT CHEM,OAK RIDGE,TN 37831. NR 29 TC 59 Z9 60 U1 0 U2 4 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0021-9673 J9 J CHROMATOGR A JI J. Chromatogr. A PD DEC 9 PY 1994 VL 687 IS 1 BP 13 EP 31 DI 10.1016/0021-9673(94)00728-4 PG 19 WC Biochemical Research Methods; Chemistry, Analytical SC Biochemistry & Molecular Biology; Chemistry GA QB867 UT WOS:A1994QB86700002 ER PT J AU KUROKI, K SPENCE, D DILLON, MA AF KUROKI, K SPENCE, D DILLON, MA TI ELECTRON-IMPACT SPECTROSCOPY OF SIF4 AND GEF4 SO JOURNAL OF ELECTRON SPECTROSCOPY AND RELATED PHENOMENA LA English DT Article DE EELS; GERMANIUM TETRAFLUORIDE; SILICON TETRAFLUORIDE ID ENERGY-LOSS SPECTROSCOPY; FAST CHARGED-PARTICLES; PHOTOABSORPTION SPECTRA; CROSS-SECTIONS; SILICON TETRAFLUORIDE; OSCILLATOR-STRENGTHS; INELASTIC-COLLISIONS; EXTREME-ULTRAVIOLET; ABSORPTION-SPECTRA; VALENCE-SHELL AB Electron energy loss spectra (EELS) of SiF4 and GeF4 have been recorded by using incident electrons with energy of 200 eV at scattering angles of about 0-9-degrees. The energy loss range of 10-30 eV covers the entire region of single-electron excitation from the five outer valence orbitals of both molecules. The spectra were obtained under conditions that favor the observation of both optically allowed and symmetry forbidden transitions. Evidence is presented for the existence of optically forbidden transitions in both molecules as well as excitations to valence as opposed to Rydberg states. C1 ARGONNE NATL LAB,ARGONNE,IL 60439. NATL RES INST POLICE SCI,TOKYO 102,JAPAN. NR 36 TC 14 Z9 14 U1 0 U2 3 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0368-2048 J9 J ELECTRON SPECTROSC JI J. Electron Spectrosc. Relat. Phenom. PD DEC 9 PY 1994 VL 70 IS 2 BP 151 EP 160 DI 10.1016/0368-2048(94)02220-T PG 10 WC Spectroscopy SC Spectroscopy GA PX034 UT WOS:A1994PX03400007 ER PT J AU RUFAEL, TS HUNTLEY, DR MULLINS, DR GLAND, JL AF RUFAEL, TS HUNTLEY, DR MULLINS, DR GLAND, JL TI ADSORPTION AND REACTIONS OF BENZENETHIOL ON THE NI(111) SURFACE SO JOURNAL OF PHYSICAL CHEMISTRY LA English DT Article ID ENERGY-LOSS SPECTROSCOPY; NICKEL; PT(111); SPECTRA; THIOPHENOL; MECHANISM; HYDROGEN; MO(110); SULFUR; FACES AB The adsorption and reactions of benzenethiol have been analyzed on the Ni(111) surface using TPD, XPS, LEED and HREELS. At 110 K, benzenethiol adsorbs on the surface through the sulfur atom. The vibrational data indicate that the S-H bond in benzenethiol breaks upon adsorption at 110 K for all exposures. The primary surface intermediate observed for high coverages of benzenethiol at 190 K is phenyl thiolate. HREELS results indicate that the aromatic ring in phenyl thiolate is neither parallel nor perpendicular to the surface, but tilted. For low coverages of benzenethiol, decomposition of the molecule to gaseous hydrogen, atomic sulfur, and carbon is the favored reaction pathway, while benzene formation is the dominant reaction for higher coverages. Two pathways are observed for the desorption of the benzene product. At intermediate coverages a desorption-limited process occurs near 400 K, while at high coverages benzene desorption is limited by hydrogenolysis of phenyl thiolate at 263 K. Above 300 K, a stable aromatic hydrocarbon intermediate, most Likely a phenyl fragment, is observed on the sulfur-covered Ni(111) surface. This intermediate stays almost parallel to the surface at 450 K. Annealing benzenethiol overlayers on the Ni(111) surface to 800 K results in a complex (root 39 x root 39)-S LEED pattern possibly as the result of the reconstruction of the top Ni layer over a broad coverage range. C1 OAK RIDGE NATL LAB,OAK RIDGE,TN 37831. UNIV MICHIGAN,DEPT CHEM,ANN ARBOR,MI 48109. NR 33 TC 28 Z9 28 U1 2 U2 6 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 SN 0022-3654 J9 J PHYS CHEM-US JI J. Phys. Chem. PD DEC 8 PY 1994 VL 98 IS 49 BP 13022 EP 13027 DI 10.1021/j100100a034 PG 6 WC Chemistry, Physical SC Chemistry GA PW303 UT WOS:A1994PW30300034 ER PT J AU WU, JQ ALBRIGHT, JG MILLER, DG AF WU, JQ ALBRIGHT, JG MILLER, DG TI ISOTHERMAL DIFFUSION-COEFFICIENTS FOR NACL-MGCL2-H2O .6. CONCENTRATION RATIO-3/1, RATIO-1/1, AND RATIO-1/3 NEAR SATURATION AT 35-DEGREES-C SO JOURNAL OF PHYSICAL CHEMISTRY LA English DT Article ID SOLUTE CONCENTRATION RATIO; MGCL2 CONCENTRATIONS; WIDE-RANGE; 25-DEGREES-C; SYSTEMS; NACL AB Isothermal interdiffusion coefficients have been obtained by the Gouy interferometric free-diffusion method for the system NaCl-MgCl2-H2O at 35 degrees C. The solute molality ratios were 3:1, 1:1, and 1:3 at total molar solute concentrations of 3.78, 3.70, and 3.58 mol dm(-3), respectively. These total molarities correspond to three nearly the same molalities for which data are available at 25 degrees C. The results suggest that within experimental error the four diffusion coefficients of this ternary system at 35 degrees C are about 1.25 times larger than their corresponding values at 25 degrees C, which is close to the fluidity ratio for pure water at these same two temperatures. However, the ratio for the main term diffusion coefficients D-11 and D-22 appeared on the average to be a little greater than this value (1.28 and 1.26), and the ratios for the cross-term diffusion coefficients D-12 and D-21 appeared to be a little less than this value (1.21 and 1.24). C1 TEXAS CHRISTIAN UNIV,DEPT CHEM,FT WORTH,TX 76129. ACAD SINICA,QINGHAI INST SALT LAKES,XINING 810008,PEOPLES R CHINA. LAWRENCE LIVERMORE NATL LAB,LIVERMORE,CA 94550. NR 23 TC 6 Z9 6 U1 0 U2 1 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 SN 0022-3654 J9 J PHYS CHEM-US JI J. Phys. Chem. PD DEC 8 PY 1994 VL 98 IS 49 BP 13054 EP 13057 DI 10.1021/j100100a039 PG 4 WC Chemistry, Physical SC Chemistry GA PW303 UT WOS:A1994PW30300039 ER PT J AU NIYAZYMBETOV, ME EVANS, DH LERKE, SA CAHILL, PA HENDERSON, CC AF NIYAZYMBETOV, ME EVANS, DH LERKE, SA CAHILL, PA HENDERSON, CC TI STUDY OF ACID-BASE AND REDOX EQUILIBRIA FOR THE C-60 C60H2 SYSTEM IN DIMETHYL-SULFOXIDE SOLVENT SO JOURNAL OF PHYSICAL CHEMISTRY LA English DT Article ID BUCKMINSTERFULLERENE; C60H2; ANION; C-60 AB Voltammetric techniques have been used to monitor the acid-base reactions of reduced forms of C-60 in dimethyl sulfoxide (DMSO) solution. In agreement with earlier work, the dihydrofullerene, C60H2, was found to show three reversible reduction processes with potentials about 0.1 V negative of the corresponding C-60 potentials in toluene/DMSO (67/33, v/v). For C60H2, the first and second acid dissociation constants are 4.7 and 16, respectively. Also, the reversible potentials for the C60H./C60H- and C60H-/C60H.- couples were found to be identical to the first two reduction potentials for C-60, within experimental error. The reversible potentials and pK(a) values were combined to compute the pK(a) of related species. For example, pK(a) for C60H. was computed to be 9. The titration of electrogenerated C-60(.-) with 4-nitrobenzoic acid (pK(a) = 9) was consistent with this calculation. C1 UNIV DELAWARE,DEPT CHEM & BIOCHEM,NEWARK,DE 19716. STERLING WINTHROP INC,COLLEGEVILLE,PA 19426. SANDIA NATL LABS,ALBUQUERQUE,NM 87185. NR 15 TC 85 Z9 85 U1 0 U2 4 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 SN 0022-3654 J9 J PHYS CHEM-US JI J. Phys. Chem. PD DEC 8 PY 1994 VL 98 IS 49 BP 13093 EP 13098 DI 10.1021/j100100a045 PG 6 WC Chemistry, Physical SC Chemistry GA PW303 UT WOS:A1994PW30300045 ER PT J AU BECKER, L BADA, JL WINANS, RE BUNCH, TE AF BECKER, L BADA, JL WINANS, RE BUNCH, TE TI FULLERENES IN ALLENDE METEORITE SO NATURE LA English DT Letter ID CHEMISTRY C1 ARGONNE NATL LAB,DIV CHEM,ARGONNE,IL 60439. NASA,AMES RES CTR,DIV SPACE SCI,MOFFETT FIELD,CA 94035. RP BECKER, L (reprint author), UNIV CALIF SAN DIEGO,SCRIPPS INST OCEANOG,LA JOLLA,CA 92093, USA. NR 10 TC 46 Z9 47 U1 0 U2 3 PU MACMILLAN MAGAZINES LTD PI LONDON PA PORTERS SOUTH, 4 CRINAN ST, LONDON, ENGLAND N1 9XW SN 0028-0836 J9 NATURE JI Nature PD DEC 8 PY 1994 VL 372 IS 6506 BP 507 EP 507 DI 10.1038/372507a0 PG 1 WC Multidisciplinary Sciences SC Science & Technology - Other Topics GA PW082 UT WOS:A1994PW08200033 PM 7990921 ER PT J AU JOYCE, MJ SHARPEYSCHAFER, JF RILEY, MA CULLEN, DM AZAIEZ, F BEAUSANG, CW CLARK, RM DAGNALL, PJ DELONCLE, I DUPRAT, J FALLON, P FORSYTH, PD FOTIADES, N GALE, SJ GALL, B HANNACHI, F HARISSOPULOS, S HAUSCHILD, K JONES, PM KALFAS, CA KORICHI, A LECOZ, Y MEYER, M PAUL, ES PORQUET, MG REDON, N SCHUCK, C SIMPSON, J VLASTOU, R WADSWORTH, R NAZAREWICZ, W AF JOYCE, MJ SHARPEYSCHAFER, JF RILEY, MA CULLEN, DM AZAIEZ, F BEAUSANG, CW CLARK, RM DAGNALL, PJ DELONCLE, I DUPRAT, J FALLON, P FORSYTH, PD FOTIADES, N GALE, SJ GALL, B HANNACHI, F HARISSOPULOS, S HAUSCHILD, K JONES, PM KALFAS, CA KORICHI, A LECOZ, Y MEYER, M PAUL, ES PORQUET, MG REDON, N SCHUCK, C SIMPSON, J VLASTOU, R WADSWORTH, R NAZAREWICZ, W TI THE N=7 UNFAVORED SUPERDEFORMED BAND IN (193)HG - CORIOLIS SPLITTING AND NEUTRON SHELL STRUCTURE AT EXTREME DEFORMATION SO PHYSICS LETTERS B LA English DT Article ID OCTUPOLE CORRELATIONS; QUANTIZED ALIGNMENT; ROTATING NUCLEI; HG-193; SPIN; STATES; EUROGAM; MOMENTS; INERTIA; REGION AB A new superdeformed band is reported in Hg-193 which has properties that are consistent with it being based on the unfavoured N = 7 (pi, alpha) = (-, + 1/2) intruder orbital. The signature splitting at HBARomega = 200 keV of this intruder orbital and its favoured (-, - 1/2) partner is estimated to be 160 +/- 30 keV, which is in agreement with cranked mean field calculations. This band completes the set of low-lying quasi-neutron orbitals predicted to be at the N = 113 superdeformed Fermi-surface. The previously known superdeformed bands in Hg-193 have been extended to higher rotational frequencies, HBARomega greater-than-or-equal-to 0.40 MeV. C1 FLORIDA STATE UNIV,DEPT PHYS,TALLAHASSEE,FL 32306. OAK RIDGE NATL LAB,DIV PHYS,OAK RIDGE,TN 37831. INST PHYS NUCL LYON,F-91406 ORSAY,FRANCE. UNIV YORK,YORK YO1 5DD,N YORKSHIRE,ENGLAND. LAWRENCE BERKELEY LAB,BERKELEY,CA 94720. CSNSM,CNRS,IN2P3,F-91405 ORSAY,FRANCE. DEMOCRITOS NUCL RES CTR,ATHENS,GREECE. SERC,DARESBURY LAB,NUCL STRUCT FACIL,WARRINGTON WA4 4AD,CHESHIRE,ENGLAND. UNIV TENNESSEE,DEPT PHYS,KNOXVILLE,TN 37996. UNIV LYON 1,INST PHYS NUCL LYON,F-69622 VILLEURBANNE,FRANCE. UNIV WARSAW,INST THEORET PHYS,PL-00681 WARSAW,POLAND. RP JOYCE, MJ (reprint author), UNIV LIVERPOOL,OLIVER LODGE LAB,LIVERPOOL L69 3BX,ENGLAND. RI Hauschild, Karl/A-6726-2009; Harissopulos, Sotirios/G-9541-2011 OI Harissopulos, Sotirios/0000-0003-4022-7595 NR 27 TC 32 Z9 32 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 DEC 8 PY 1994 VL 340 IS 3 BP 150 EP 154 DI 10.1016/0370-2693(94)01285-7 PG 5 WC Astronomy & Astrophysics; Physics, Nuclear; Physics, Particles & Fields SC Astronomy & Astrophysics; Physics GA PW163 UT WOS:A1994PW16300002 ER PT J AU AHMED, T AID, S ANDREEV, V ANDRIEU, B APPUHN, RD ARPAGAUS, M BABAEV, A BAEHR, J BAN, J BARANOV, P BARRELET, E BARTEL, W BARTH, M BASSLER, U BECK, HP BEHREND, HJ BELOUSOV, A BERGER, C BERGSTEIN, H BERNARDI, G BERNET, R BERTRANDCOREMANS, G BESANCON, M BIDDULPH, P BIZOT, JC BLOBEL, V BORRAS, K BOTTERWECK, F BOUDRY, V BRAEMER, A BRASSE, F BRAUNSCHWEIG, W BRISSON, V BRUNCKO, D BRUNE, C BUCHHOLZ, R BUNGENER, L BURGER, J BUSSER, FW BUNIATIAN, A BURKE, S BUSCHHORN, G CAMPBELL, AJ CARLI, T CHARLES, F CLARKE, D CLEGG, AB COLOMBO, M CONTRERAS, JG COUGHLAN, JA COURAU, A COUTURES, C COZZIKA, G CRIEGEE, L CUSSANS, DG CVACH, J DAGORET, S DAINTON, JB DANILOV, M DAU, WD DAUM, K DAVID, M DEFFUR, E DELCOURT, B DELBUONO, L DEROECK, A DEWOLF, EA DINEZZA, P DOLLFUS, C DOWELL, JD DREIS, HB DUBOC, J DULLMANN, D DUNGER, O DUHM, H EBERT, J EBERT, TR ECKERLIN, G EFREMENKO, V EGLI, S EHRLICHMANN, H EICHENBERGER, S EICHLER, R EISELE, F EISENHANDLER, E ELLISON, RJ ELSEN, E ERDMANN, M EVRARD, E FAVART, L FEDOTOV, A FEEKEN, D FELST, R FELTESSE, J FERENCEI, J FERRAROTTO, F FLAMM, K FLEISCHER, M FLIESER, M FLUGGE, G FOMENKO, A FOMINYKH, B FORBUSH, M FORMANEK, J FOSTER, JM FRANKE, G FRETWURST, E GABATHULER, E GABATHULER, K GAMERDINGER, K GARVEY, J GAYLER, J GEBAUER, M GELLRICH, A GENZEL, H GERHARDS, R GOERLACH, U GOERLICH, L GOGITIDZE, N GOLDBERG, M GOLDNER, D GONZALEZPINEIRO, B GOODALL, AM GORELOV, I GORITCHEV, P GRAB, C GRASSLER, H GRASSLER, R GREENSHAW, T GRINDHAMMER, G GRUBER, A GRUBER, C HAACK, J HAIDT, D HAJDUK, L HAMON, O HAMPEL, M HANLON, EM HAPKE, M HAYNES, WJ HEATHERINGTON, J HEDBERG, V HEINZELMANN, G HENDERSON, RCW HENSCHEL, H HERMA, R HERYNEK, I HESS, MF HILDESHEIM, W HILL, P HILLER, KH HILTON, CD HLADKY, J HOEGER, KC HOPPNER, M HORISBERGER, R HUET, P HUFNAGEL, H IBBOTSON, M ITTERBECK, H JABIOL, MA JACHOLKOWSKA, A JACOBSSON, C JAFFRE, M JANOTH, J JANSEN, T JONSSON, L JOHANNSEN, K JOHNSON, DP JOHNSON, L JUNG, H KALMUS, PIP KANT, D KASCHOWITZ, R KASSELMANN, P KATHAGE, U KAUFMANN, HH KAZARIAN, S KENYON, IR KERMICHE, S KEUKER, C KIESLING, C KLEIN, M KLEINWORT, C KNIES, G KO, W KOHLER, T KOLANOSKI, H KOLE, F KOLYA, SD KORBEL, V KORN, M KOSTKA, P KOTELNIKOV, SK KRASNY, MW KREHBIEL, H KRUCKER, D KRUGER, U KRUNERMARQUIS, U KUBENKA, JP KUSTER, H KUHLEN, M KURCA, T KURZHOFER, J KUZNIK, B LACOUR, D LAMARCHE, F LANDER, R LANDON, MPJ LANGE, W LANIUS, P LAPORTE, JF LEBEDEV, A LEVERENZ, C LEVONIAN, S LEY, C LINDNER, A LINDSTROM, G LINSEL, F LIPINSKI, J LIST, B LOCH, P LOHMANDER, H LOPEZ, GC LUKE, D MAGNUSSEN, N MALINOVSKI, E MANI, S MARACEK, R MARAGE, P MARSHALL, R MARTENS, J MARTIN, R MARTYN, HU MARTYNIAK, J MASSON, S MAVROIDIS, T MAXFIELD, SJ MCMAHON, SJ MEHTA, A MEIER, K MERCER, D MERZ, T MEYER, CA MEYER, H MEYER, J MIKOCKI, S MILSTEAD, D MOREAU, F MORRIS, JV MULLER, G MULLER, K MURIN, P NAGOVIZIN, V NAHNHAUER, R NAROSKA, B NAUMANN, T NEWMAN, PR NEWTON, D NEYRET, D NGUYEN, HK NIEBERGALL, F NIEBUHR, C NISIUS, R NOWAK, G NOYES, GW NYBERGWERTHER, M OBERLACK, H OBROCK, U OLSSON, JE PANITCH, A PASCAUD, C PATEL, GD PEPPEL, E PEREZ, E PHILLIPS, JP PICHLER, C PITZL, D POPE, G PRELL, S PROSI, R RADEL, G RAUPACH, F REIMER, P REINSHAGEN, S RIBARICS, P RIECH, V RIEDLBERGER, J RIESS, S RIETZ, M ROBERTSON, SM ROBMANN, P ROLOFF, HE ROOSEN, R ROSENBAUER, K ROSTOVTSEV, A ROUSE, F ROYON, C RUTER, K RUSAKOV, S RYBICKI, K RYLKO, R SAHLMANN, N SANCHEZ, E SANKEY, DPC SAVITSKY, M SCHACHT, P SCHIEK, S SCHLEPER, P VONSCHLIPPE, W SCHMIDT, C SCHMIDT, D SCHMIDT, G SCHONING, A SCHRODER, V SCHUHMANN, E SCHWAB, B SCHWIND, A SEEHAUSEN, U SEFKOW, F SEIDEL, M SELL, R SEMENOV, A SHEKELYAN, V SHEVIAKOV, I SHOOSHTARI, H SHTARKOV, LN SIEGMON, G SIEWERT, U SIROIS, Y SKILLICORN, IO SMIRNOV, P SMITH, JR SOLOVIEV, Y SPITZER, H STAROSTA, R STEENBOCK, M STEFFEN, P STEINBERG, R STELLA, B STEPHENS, K STIER, J STIEWE, J STOSSLEIN, U STRACHOTA, J STRAUMANN, U STRUCZINSKI, W SUTTON, JP TAPPROGGE, S TAYLOR, RE TCHERNYSHOV, V THIEBAUX, C THOMPSON, G TICHOMIROV, I TRUOL, P TURNAU, J TUTAS, J UELKES, P USIK, A VALKAR, S VALKAROVA, A VALLEE, C VANESCH, P VANMECHELEN, P VARTAPETIAN, A VAZDIK, Y VECKO, M VERRECCHIA, P VILLET, G WACKER, K WAGENER, A WALKER, IW WALTHER, A WEBER, G WEBER, M WEGENER, D WEGNER, A WELLISCH, HP WEST, LR WILLARD, S WINDE, M WINTER, GG WOLFF, T WRIGHT, AE WUNSCH, E WULFF, N YIOU, TP ZACEK, J ZHANG, Z ZIMMER, M ZIMMERMANN, W ZOMER, F ZUBER, K AF AHMED, T AID, S ANDREEV, V ANDRIEU, B APPUHN, RD ARPAGAUS, M BABAEV, A BAEHR, J BAN, J BARANOV, P BARRELET, E BARTEL, W BARTH, M BASSLER, U BECK, HP BEHREND, HJ BELOUSOV, A BERGER, C BERGSTEIN, H BERNARDI, G BERNET, R BERTRANDCOREMANS, G BESANCON, M BIDDULPH, P BIZOT, JC BLOBEL, V BORRAS, K BOTTERWECK, F BOUDRY, V BRAEMER, A BRASSE, F BRAUNSCHWEIG, W BRISSON, V BRUNCKO, D BRUNE, C BUCHHOLZ, R BUNGENER, L BURGER, J BUSSER, FW BUNIATIAN, A BURKE, S BUSCHHORN, G CAMPBELL, AJ CARLI, T CHARLES, F CLARKE, D CLEGG, AB COLOMBO, M CONTRERAS, JG COUGHLAN, JA COURAU, A COUTURES, C COZZIKA, G CRIEGEE, L CUSSANS, DG CVACH, J DAGORET, S DAINTON, JB DANILOV, M DAU, WD DAUM, K DAVID, M DEFFUR, E DELCOURT, B DELBUONO, L DEROECK, A DEWOLF, EA DINEZZA, P DOLLFUS, C DOWELL, JD DREIS, HB DUBOC, J DULLMANN, D DUNGER, O DUHM, H EBERT, J EBERT, TR ECKERLIN, G EFREMENKO, V EGLI, S EHRLICHMANN, H EICHENBERGER, S EICHLER, R EISELE, F EISENHANDLER, E ELLISON, RJ ELSEN, E ERDMANN, M EVRARD, E FAVART, L FEDOTOV, A FEEKEN, D FELST, R FELTESSE, J FERENCEI, J FERRAROTTO, F FLAMM, K FLEISCHER, M FLIESER, M FLUGGE, G FOMENKO, A FOMINYKH, B FORBUSH, M FORMANEK, J FOSTER, JM FRANKE, G FRETWURST, E GABATHULER, E GABATHULER, K GAMERDINGER, K GARVEY, J GAYLER, J GEBAUER, M GELLRICH, A GENZEL, H GERHARDS, R GOERLACH, U GOERLICH, L GOGITIDZE, N GOLDBERG, M GOLDNER, D GONZALEZPINEIRO, B GOODALL, AM GORELOV, I GORITCHEV, P GRAB, C GRASSLER, H GRASSLER, R GREENSHAW, T GRINDHAMMER, G GRUBER, A GRUBER, C HAACK, J HAIDT, D HAJDUK, L HAMON, O HAMPEL, M HANLON, EM HAPKE, M HAYNES, WJ HEATHERINGTON, J HEDBERG, V HEINZELMANN, G HENDERSON, RCW HENSCHEL, H HERMA, R HERYNEK, I HESS, MF HILDESHEIM, W HILL, P HILLER, KH HILTON, CD HLADKY, J HOEGER, KC HOPPNER, M HORISBERGER, R HUET, P HUFNAGEL, H IBBOTSON, M ITTERBECK, H JABIOL, MA JACHOLKOWSKA, A JACOBSSON, C JAFFRE, M JANOTH, J JANSEN, T JONSSON, L JOHANNSEN, K JOHNSON, DP JOHNSON, L JUNG, H KALMUS, PIP KANT, D KASCHOWITZ, R KASSELMANN, P KATHAGE, U KAUFMANN, HH KAZARIAN, S KENYON, IR KERMICHE, S KEUKER, C KIESLING, C KLEIN, M KLEINWORT, C KNIES, G KO, W KOHLER, T KOLANOSKI, H KOLE, F KOLYA, SD KORBEL, V KORN, M KOSTKA, P KOTELNIKOV, SK KRASNY, MW KREHBIEL, H KRUCKER, D KRUGER, U KRUNERMARQUIS, U KUBENKA, JP KUSTER, H KUHLEN, M KURCA, T KURZHOFER, J KUZNIK, B LACOUR, D LAMARCHE, F LANDER, R LANDON, MPJ LANGE, W LANIUS, P LAPORTE, JF LEBEDEV, A LEVERENZ, C LEVONIAN, S LEY, C LINDNER, A LINDSTROM, G LINSEL, F LIPINSKI, J LIST, B LOCH, P LOHMANDER, H LOPEZ, GC LUKE, D MAGNUSSEN, N MALINOVSKI, E MANI, S MARACEK, R MARAGE, P MARSHALL, R MARTENS, J MARTIN, R MARTYN, HU MARTYNIAK, J MASSON, S MAVROIDIS, T MAXFIELD, SJ MCMAHON, SJ MEHTA, A MEIER, K MERCER, D MERZ, T MEYER, CA MEYER, H MEYER, J MIKOCKI, S MILSTEAD, D MOREAU, F MORRIS, JV MULLER, G MULLER, K MURIN, P NAGOVIZIN, V NAHNHAUER, R NAROSKA, B NAUMANN, T NEWMAN, PR NEWTON, D NEYRET, D NGUYEN, HK NIEBERGALL, F NIEBUHR, C NISIUS, R NOWAK, G NOYES, GW NYBERGWERTHER, M OBERLACK, H OBROCK, U OLSSON, JE PANITCH, A PASCAUD, C PATEL, GD PEPPEL, E PEREZ, E PHILLIPS, JP PICHLER, C PITZL, D POPE, G PRELL, S PROSI, R RADEL, G RAUPACH, F REIMER, P REINSHAGEN, S RIBARICS, P RIECH, V RIEDLBERGER, J RIESS, S RIETZ, M ROBERTSON, SM ROBMANN, P ROLOFF, HE ROOSEN, R ROSENBAUER, K ROSTOVTSEV, A ROUSE, F ROYON, C RUTER, K RUSAKOV, S RYBICKI, K RYLKO, R SAHLMANN, N SANCHEZ, E SANKEY, DPC SAVITSKY, M SCHACHT, P SCHIEK, S SCHLEPER, P VONSCHLIPPE, W SCHMIDT, C SCHMIDT, D SCHMIDT, G SCHONING, A SCHRODER, V SCHUHMANN, E SCHWAB, B SCHWIND, A SEEHAUSEN, U SEFKOW, F SEIDEL, M SELL, R SEMENOV, A SHEKELYAN, V SHEVIAKOV, I SHOOSHTARI, H SHTARKOV, LN SIEGMON, G SIEWERT, U SIROIS, Y SKILLICORN, IO SMIRNOV, P SMITH, JR SOLOVIEV, Y SPITZER, H STAROSTA, R STEENBOCK, M STEFFEN, P STEINBERG, R STELLA, B STEPHENS, K STIER, J STIEWE, J STOSSLEIN, U STRACHOTA, J STRAUMANN, U STRUCZINSKI, W SUTTON, JP TAPPROGGE, S TAYLOR, RE TCHERNYSHOV, V THIEBAUX, C THOMPSON, G TICHOMIROV, I TRUOL, P TURNAU, J TUTAS, J UELKES, P USIK, A VALKAR, S VALKAROVA, A VALLEE, C VANESCH, P VANMECHELEN, P VARTAPETIAN, A VAZDIK, Y VECKO, M VERRECCHIA, P VILLET, G WACKER, K WAGENER, A WALKER, IW WALTHER, A WEBER, G WEBER, M WEGENER, D WEGNER, A WELLISCH, HP WEST, LR WILLARD, S WINDE, M WINTER, GG WOLFF, T WRIGHT, AE WUNSCH, E WULFF, N YIOU, TP ZACEK, J ZHANG, Z ZIMMER, M ZIMMERMANN, W ZOMER, F ZUBER, K TI A SEARCH FOR HEAVY-LEPTONS AT HERA SO PHYSICS LETTERS B LA English DT Article ID EXCITED LEPTONS; E+E; LEP; NEUTRINOS; DETECTOR; QUARKS; DECAYS AB A search for direct production of new leptons in the mass range from 10 GeV up to 225 GeV is presented by the H1 experiment at HERA. The data were obtained during 1993 and correspond to an integrated luminosity of 528 nb-1. The search includes heavy lepton decays to final states e (nu) gamma and e (nu) W, e (nu) Z with the subsequent decay of the W and Z bosons into jets or lepton pairs. No evidence was found for the production of new massive electrons or neutrinos in any of the decay channels. Rejection limits for excited electrons and neutrinos are derived. C1 RHEIN WESTFAL TH AACHEN,INST PHYS 1,AACHEN,GERMANY. RHEIN WESTFAL TH AACHEN,INST PHYS 3,AACHEN,GERMANY. UNIV BIRMINGHAM,SCH PHYS & SPACE RES,BIRMINGHAM B15 2TT,W MIDLANDS,ENGLAND. VUB,ULB,INTER UNIV INST HIGH ENERGIES,BRUSSELS,BELGIUM. RUTHERFORD APPLETON LAB,DIDCOT OX11 0QX,OXON,ENGLAND. INST NUCL PHYS,PL-31342 KRAKOW,POLAND. UNIV CALIF DAVIS,DEPT PHYS,DAVIS,CA 95616. UNIV CALIF DAVIS,IIRPA,DAVIS,CA 95616. UNIV DORTMUND,INST PHYS,W-4600 DORTMUND 50,GERMANY. CE SACLAY,DAPNIA,DSM,CEA,GIF SUR YVETTE,FRANCE. UNIV GLASGOW,DEPT PHYS & ASTRON,GLASGOW G12 8QQ,SCOTLAND. DESY,W-2000 HAMBURG 52,GERMANY. UNIV HAMBURG,INST EXPTL PHYS 1,W-2000 HAMBURG 13,GERMANY. UNIV HAMBURG,INST EXPTL PHYS 2,W-2000 HAMBURG 13,GERMANY. UNIV HEIDELBERG,INST PHYS,W-6900 HEIDELBERG,GERMANY. UNIV HEIDELBERG,INST HOCHENERGIEPHYS,W-6900 HEIDELBERG,GERMANY. SLOVAK ACAD SCI,INST EXPTL PHYS,CS-80936 BRATISLAVA,SLOVAKIA. UNIV LANCASTER,SCH PHYS & MAT,LANCASTER LA1 4YL,ENGLAND. UNIV LIVERPOOL,DEPT PHYS,LIVERPOOL L69 3BX,ENGLAND. QUEEN MARY & WESTFIELD COLL,LONDON,ENGLAND. LUND UNIV,DEPT PHYS,S-22101 LUND,SWEDEN. UNIV MANCHESTER,DEPT PHYS,MANCHESTER M13 9PL,LANCS,ENGLAND. MOSCOW THEORET & EXPTL PHYS INST,MOSCOW,RUSSIA. PN LEBEDEV PHYS INST,MOSCOW,RUSSIA. MAX PLANCK INST PHYS & ASTROPHYS,MUNICH,GERMANY. UNIV PARIS 11,LAL,CNRS,IN2P3,F-91405 ORSAY,FRANCE. ECOLE POLYTECH,LPNHE,CNRS,IN2P3,F-91128 PALAISEAU,FRANCE. UNIV PARIS 06,LPNHE,PARIS,FRANCE. UNIV PARIS 07,CNRS,IN2P3,F-75221 PARIS 05,FRANCE. CZECHOSLOVAK ACAD SCI,INST PHYS,CS-11142 PRAGUE 1,CZECH REPUBLIC. CHARLES UNIV,CTR NUCL,CS-11636 PRAGUE 1,CZECH REPUBLIC. INFN,ROME,ITALY. UNIV ROMA LA SAPIENZA,DIPARTIMENTO FIS,I-00185 ROME,ITALY. PAUL SCHERRER INST,VILLIGEN,SWITZERLAND. BERG UNIV GESAMTHSCH WUPPERTAL,FACHBEREICH PHYS,WUPPERTAL,GERMANY. DESY,INST HOCHENERGIEPHYS,ZEUTHEN,GERMANY. SWISS FED INST TECHNOL,INST TEILCHENPHYS,CH-8092 ZURICH,SWITZERLAND. UNIV ZURICH,INST PHYS,CH-8006 ZURICH,SWITZERLAND. STANFORD UNIV,STANFORD LINEAR ACCELERATOR CTR,STANFORD,CA 94305. RI Meyer, Curtis/L-3488-2014; Soloviev, Yury/M-8788-2015; Levonian, Sergey/M-8693-2015; Andreev, Vladimir/M-8665-2015; Fomenko, Alexander/I-7900-2014; Malinovski, Evgenii/N-1034-2015; Gogitidze, Nelli/N-1224-2015; Belousov, Anatoli/N-2102-2015; Vazdik, Iakov/N-2624-2015; Gorelov, Igor/J-9010-2015; Sheviakov, Igor/N-2735-2015; Danilov, Mikhail/C-5380-2014; Kotelnikov, Sergey/A-9711-2014; Cvach, Jaroslav/G-6269-2014; OI Meyer, Curtis/0000-0001-7599-3973; Soloviev, Yury/0000-0003-1136-2827; Gorelov, Igor/0000-0001-5570-0133; Sheviakov, Igor/0000-0002-1659-3483; Danilov, Mikhail/0000-0001-9227-5164; Kotelnikov, Sergey/0000-0002-8027-4612; Erdmann, Martin/0000-0002-1653-1303; Beck, Hans Peter/0000-0001-7212-1096; Bassler, Ursula/0000-0002-9041-3057 NR 33 TC 13 Z9 13 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 DEC 8 PY 1994 VL 340 IS 3 BP 205 EP 216 DI 10.1016/0370-2693(94)01301-2 PG 12 WC Astronomy & Astrophysics; Physics, Nuclear; Physics, Particles & Fields SC Astronomy & Astrophysics; Physics GA PW163 UT WOS:A1994PW16300012 ER PT J AU ZHAO, JT CORBETT, JD AF ZHAO, JT CORBETT, JD TI ZINTL PHASES IN ALKALI-METAL-TIN SYSTEMS - K8SN25 WITH CONDENSED PENTAGONAL DODECAHEDRA OF TIN - 2 A(8)SN(44) PHASES WITH A DEFECT CLATHRATE STRUCTURE SO INORGANIC CHEMISTRY LA English DT Article ID HOMOPOLYATOMIC ANIONS; CLUSTERS; NETWORK AB Single-phase K8Sn25 is synthesized from the elements on annealing below 400 degrees C. The phase is somewhat nonstoichiometric, and the lattice constant also depends on thermal history. The structure was solved for K-7.4(1-)Sn-25 (s.g. P4(1)32, Z = 4, a = 16.294(5) Angstrom, R/R(w) = 4.0/3.6% for 833 observed reflections and 55 parameters). The new structure type contains pentagonal dodecahedra of tin that share three pentagonal faces with like members and are also interconnected to another cage through a single exo bond. Tin-tin distances are very similar to those in gray tin and in Rb8Sn44. The three types of potassium ions are (1) encapsulated in each Sn-20 cage, (2) bonded in tin octahedra between clusters, and (3) somewhat disordered in channels through the tin network. Eight tin atoms per formula unit are three-bonded, the remainder four-bonded, and the ideal compositon K8.0Sn25 is, appropriately, a diamagnetic semiconductor. An analogous compound does not form in the binary rubidium or cesium-systems. The crystal structures of the isostructural Rb8Sn44.6(1) and K-1.6(2)Cs-6.4(2)Sn-44.0(1) were also refined (Pm3n, Z = 1, a = 12.054(1), 12.084(1) Angstrom, R/R(w) = 7.6/6.7, 6.6/5.7, respectively). These are defect members of the clathrate-I A(8)(H2O)(46) type structure with one-third random vacancies at the 6c positions and classical Zintl phases. K8Sn44 was shown to be a diamagnetic semiconductor. C1 IOWA STATE UNIV SCI & TECHNOL,AMES LAB,AMES,IA 50011. IOWA STATE UNIV SCI & TECHNOL,DEPT CHEM,AMES,IA 50011. NR 36 TC 117 Z9 117 U1 1 U2 17 PU AMER CHEMICAL SOC PI WASHINGTON PA PO BOX 57136, WASHINGTON, DC 20037-0136 SN 0020-1669 J9 INORG CHEM JI Inorg. Chem. PD DEC 7 PY 1994 VL 33 IS 25 BP 5721 EP 5726 DI 10.1021/ic00103a019 PG 6 WC Chemistry, Inorganic & Nuclear SC Chemistry GA PW092 UT WOS:A1994PW09200019 ER PT J AU SZALDA, DJ FUJITA, E SANZENBACHER, R PAULUS, H ELIAS, H AF SZALDA, DJ FUJITA, E SANZENBACHER, R PAULUS, H ELIAS, H TI SYNTHESES AND PROPERTIES OF NICKEL(I) AND NICKEL(II) COMPLEXES OF A SERIES OF MACROCYCLIC N-4 LIGANDS - CRYSTAL-STRUCTURES OF C-RSSR-[NI(I)HTIM](CLO4), C-RSSR-[NI(II)HTIM](CLO4)2, C-RRSS-[NI(II)HTIM](CLO4)(2), AND [NI(II)TIM](CLO4)(2) (HTIM=2,3,9,10-TETRAMETHYL-1,4,8,11-TETRAAZACYCLOTETRADECANE, TIM=2,3,9,10-TETRAMETHYL-1,4,8,11-TETRAAZACYCLOTETRADECA-1,3,8,10-TETRAE NE) SO INORGANIC CHEMISTRY LA English DT Article ID MONO-VALENT NICKEL; METHANOGENIC BACTERIA; CARBON-DIOXIDE; ELECTROCATALYTIC REDUCTION; AQUEOUS-SOLUTIONS; METHANOBACTERIUM-THERMOAUTOTROPHICUM; ELECTROCHEMICAL REDUCTION; PHOTOCHEMICAL REDUCTION; CONFIGURATIONAL ISOMERS; MACROTRICYCLIC LIGANDS AB Two isomers of the square-planar nickel(II) complex of 2,3,9,10-tetramethyl-1,4,8,11-tetraazacyclotetradecane (HTIM) were prepared from the nickel(II) complex of 2,3,9,10-tetramethyl-1,4,8,11-tetraazacyclotetradeca-1,3,8,-10-tetraene (TIM) by NaBH4 reduction in aqueous solution. The properties of Ni(II) complexes, Ni(I) complexes, and Ni(I)-CO complexes with a series of 14-membered macrocyclic N-4 ligands were studied by means of UV-vis, NMR, and IR spectroscopy. The CO binding constants range from 1.3 x 10(2) to 2.8 x 10(5) M(-1) at 25 degrees C in acetonitrile. The crystal structures of C-RSSR-[Ni(I)HTIM]ClO4 (1), C-RSSR-[Ni(II)HTIM](ClO4)(2) (2), C-RRSS-[Ni(II)HTIM](ClO4)(2) (3) and [Ni(II)TIM](ClO4)(2) (4) have been determined from single-crystal X-ray diffraction data collected by using Mo Ka radiation. Crystallographic data are as follows: (1) trigonal space group R ($) over bar 3 with a 11.971(3) Angstrom, alpha = 107.46(2)degrees, V = 1410.3(5) Angstrom(3), Z = 3; (2) triclinic space group P ($) over bar 1 with a = 8.503(2) Angstrom, b = 8.438(2) Angstrom, c = 8.028(2) Angstrom, alpha = 102.63(1)degrees, beta = 104.81(1)degrees, gamma = 101.76(1)0, V= 522.4(4) Angstrom(3), Z = 1; (3) monoclinic space group P2(1)/c with a = 8.307(4) Angstrom, b = 12.521(6) Angstrom, c = 10.587(6) Angstrom, beta = 103.66(2)degrees, V = 1070(2) Angstrom(3), Z = 2; (4) orthorhombic space group Pnma with a = 13.189(2) Angstrom, b = 11.672(2) Angstrom, c = 13.757(3) Angstrom, V = 2118(1) Angstrom(3), Z = 4. All complexes have square-planar'geometry and the stereochemistry of the four coordinating N atoms in complexes (1), (2), and (3) is Trans III. Although the two sets of Ni-N distances of 2.083(3) and 2.053(3) Angstrom for the Ni(I) complex, (I), are much longer than those of 1.969(1) and 1.948(2) Angstrom for the corresponding Ni(II) complex, (2), distortion of the macrocycle core was not observed upon the reduction of the metal center. The structural changes associated with the reduction of Ni(II) to Ni(I) in square-planar complexes can be classified in three ways: (1) expansion of Ni-N distances; (2) distortion of nickel core; (3) both expansion and distortion. C1 BROOKHAVEN NATL LAB,DEPT CHEM,UPTON,NY 11973. TH DARMSTADT,EDUARD ZINTL INST ANORGAN CHEM,D-64289 DARMSTADT,GERMANY. BARUCH COLL,DEPT NAT SCI,NEW YORK,NY. BROOKHAVEN NATL LAB,UPTON,NY 11973. FACHBEREICH MAT WISSENSCH,DARMSTADT,GERMANY. RI Fujita, Etsuko/D-8814-2013 NR 79 TC 58 Z9 58 U1 1 U2 23 PU AMER CHEMICAL SOC PI WASHINGTON PA PO BOX 57136, WASHINGTON, DC 20037-0136 SN 0020-1669 J9 INORG CHEM JI Inorg. Chem. PD DEC 7 PY 1994 VL 33 IS 25 BP 5855 EP 5863 DI 10.1021/ic00103a038 PG 9 WC Chemistry, Inorganic & Nuclear SC Chemistry GA PW092 UT WOS:A1994PW09200038 ER PT J AU CLARK, DL GORDON, JC HUFFMAN, JC VINCENTHOLLIS, RL WATKIN, JG ZWICK, BD AF CLARK, DL GORDON, JC HUFFMAN, JC VINCENTHOLLIS, RL WATKIN, JG ZWICK, BD TI PREPARATION AND X-RAY STRUCTURES OF K[LN(O-2,6-I-PR2C6H3)4] (LN=LA, ND, ER) - EXTENDED-CHAIN STRUCTURES OF LANTHANIDE TETRAKIS(ARYLOXIDE) ANIONS BRIDGED BY POTASSIUM-ETA-ARENE INTERACTIONS SO INORGANIC CHEMISTRY LA English DT Article ID THF = TETRAHYDROFURAN; LEWIS BASE ADDUCTS; CRYSTAL-STRUCTURE; ALKALI-METAL; MOLECULAR-STRUCTURE; ALKOXIDE CHEMISTRY; COMPLEXES; YTTRIUM; DERIVATIVES; REACTIVITY AB Reaction of several lanthanide trichlorides LnCl(3) (Ln = La, Nd, Er, Lu) with 3 or 4 equiv of potassium 2,6-diisopropylphenoxide in THF solution leads to the formation of potassium salts of formula K[Ln(O-2,6-i-Pr2C6H3)(4)] [Ln = Nd (5), Er (6), Lu (7), La(8)]. These salts exhibit unusual solid-state structures involving multihapto potassium-pi-arene interactions. Not all lanthanide trichlorides produce the potassium salt directly from this reaction, and the nature of the product appears to be related to the solubility of the LnCl(3) starting material in THF solution. Compounds 5 and 6 exist in the solid state as pseudo-one-dimensional infinite-chain structures featuring multihapto K-C interactions with phenyl rings from two adjacent [Ln(OAr)(4)](-) units. Compound 8 forms a pseudo-two-dimensional sheet structure, with multihapto K-C interactions linking three neighboring [Ln(OAr)(4)](-) units. Ln-O distances within the tetrahedral [Ln(OAr)(4)](-) units average 2.211(12) (5), 2.084(14) (6) and 2.253(6) Angstrom (8). Potassium-carbon distances of the arene rings are in the ranges 3.097(8)-3.772(11) Angstrom (5), 3.018(8)-3.484(10) Angstrom (6) and 3.089(3)-3.519(4) Angstrom (8). Crystal data for 5 (at -171 degrees C): monoclinic space group P2(1)/n, a = 12.990(4) Angstrom, b = 18.977(6) Angstrom, c = 18.594(5) Angstrom, beta = 93.94(1)degrees, V = 4572.66 Angstrom(3), d(calc) = 1.296 g cm(-3), Z = 4, R = 0.0538, R(W) = 0.0530. Crystal data for 6 (at -161 degrees C): monoclinic space group P2(1)/n, a = 10.567(3) Angstrom, b = 20.856(6) Angstrom, c = 20.938(6) Angstrom, beta = 102.72(1)degrees V = 4500.93 Angstrom(3), d(calc) = 1.351 g cm(-3), Z = 4, R = 0.0362, R(W) = 0.0368. Crystal data for 8 (at -171 degrees C): orthorhombic space group Pcab, a = 19.153(2) Angstrom, b = 20.898(3) Angstrom, c = 22.673(3) Angstrom, V = 9074.66 Angstrom(3), d(calc) = 1.299 g cm(-3), Z = 8, R = 0.0272, R(W) = 0.0281. C1 LOS ALAMOS NATL LAB,DIV NUCL MAT TECHNOL,LOS ALAMOS,NM 87545. INDIANA UNIV,CTR MOLEC STRUCT,DEPT CHEM,BLOOMINGTON,IN 47405. RP CLARK, DL (reprint author), LOS ALAMOS NATL LAB,DIV CHEM SCI & TECHNOL,LOS ALAMOS,NM 87545, USA. RI Clark, David/A-9729-2011 NR 73 TC 83 Z9 84 U1 0 U2 2 PU AMER CHEMICAL SOC PI WASHINGTON PA PO BOX 57136, WASHINGTON, DC 20037-0136 SN 0020-1669 J9 INORG CHEM JI Inorg. Chem. PD DEC 7 PY 1994 VL 33 IS 25 BP 5903 EP 5911 DI 10.1021/ic00103a044 PG 9 WC Chemistry, Inorganic & Nuclear SC Chemistry GA PW092 UT WOS:A1994PW09200044 ER PT J AU BATZER, MA STONEKING, M ALEGRIAHARTMAN, M BAZAN, H KASS, DH SHAIKH, TH NOVICK, GE IOANNOU, PA SCHEER, WD HERRERA, RJ DEININGER, PL AF BATZER, MA STONEKING, M ALEGRIAHARTMAN, M BAZAN, H KASS, DH SHAIKH, TH NOVICK, GE IOANNOU, PA SCHEER, WD HERRERA, RJ DEININGER, PL TI AFRICAN ORIGIN OF HUMAN-SPECIFIC POLYMORPHIC ALU INSERTIONS SO PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF THE UNITED STATES OF AMERICA LA English DT Article ID HUMAN MITOCHONDRIAL-DNA; HUMAN-EVOLUTION; HUMAN-POPULATIONS; GENETIC-DISTANCE; FAMILY MEMBERS; SUBFAMILY; REPEATS; TREES AB Alu elements are a family of interspersed repeats that have mobilized throughout primate genomes by retroposition from a few ''master'' genes. Among the 500,000 Alu elements in the human genome are members of the human-specific subfamily that are not feued in the human species; that is, not all chromosomes carry an Alu element at a particular locus. Four such polymorphic human-specific Alu insertions were analyzed by a rapid, PCR-based assay that uses primers that flank the insertion point to determine genotypes based on the presence or absence of the Alu element. These four polymorphic Alu insertions were shown to be absent from the genomes of a number of nonhuman primates, consistent with their arising as human genetic polymorphisms sometime after the human/African ape divergence. Analysis of 664 unrelated individuals from 16 population groups from around the world revealed substantial levels of variation within population groups and significant genetic differentiation among groups. No significant associations were found among the four loci, consistent with their location on different chromosomes. A maximum-likelihood tree of population relationships showed four major groupings consisting of Africa, Europe, Asia/Americas, and Australia/New Guinea, which is concordant with similar trees based on other loci. A particularly useful feature of the polymorphic Alu insertions is that the ancestral state is known to be the absence of the Alu element, and the presence of the Alu element at a particular chromosomal site reflects a single, unique event in human evolution. A hypothetical ancestral group can then be included in the tree analysis, with the frequency of each insertion set to zero. The ancestral group connected to the maximum-likelihood tree within the African branch, which suggests an African origin of these polymorphic Alu insertions. These data are concordant with other diverse data sets, which lends further support to the recent African origin hypothesis for modern humans. Polymorphic Alu insertions represent a source of genetic variation for studying human population structure and evolution. C1 PENN STATE UNIV,DEPT ANTHROPOL,UNIVERSITY PK,PA 16802. LOUISIANA STATE UNIV,MED CTR,DEPT BIOCHEM & MOLEC BIOL,NEW ORLEANS,LA 70112. LOUISIANA STATE UNIV,MED CTR,DEPT PATHOL,NEW ORLEANS,LA 70112. FLORIDA INT UNIV,DEPT BIOL SCI,MIAMI,FL 33199. CYPRUS INST NEUROL & GENET,NICOSIA,CYPRUS. ALTON OCHSNER MED FDN & OCHSNER CLIN,MOLEC GENET LAB,NEW ORLEANS,LA 70121. RP BATZER, MA (reprint author), LAWRENCE LIVERMORE NATL LAB,CTR HUMAN GENOME,BIOL & BIOTECHNOL RES PROGRAM,L-452,LIVERMORE,CA 94551, USA. OI Deininger, Prescott/0000-0002-1067-3028 FU NCRR NIH HHS [RR08205]; NHGRI NIH HHS [R01 HG 00770]; NHLBI NIH HHS [HL-42082] NR 45 TC 239 Z9 246 U1 1 U2 30 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 DEC 6 PY 1994 VL 91 IS 25 BP 12288 EP 12292 DI 10.1073/pnas.91.25.12288 PG 5 WC Multidisciplinary Sciences SC Science & Technology - Other Topics GA PW708 UT WOS:A1994PW70800107 PM 7991620 ER PT J AU CAO, SQ PEDRAZA, AJ LOWNDES, DH ALLARD, LF AF CAO, SQ PEDRAZA, AJ LOWNDES, DH ALLARD, LF TI GAMMA-AL2O3 FORMATION FROM PULSED-LASER IRRADIATED SAPPHIRE SO APPLIED PHYSICS LETTERS LA English DT Article ID ALUMINA C1 OAK RIDGE NATL LAB,DIV SOLID STATE,OAK RIDGE,TN 37831. OAK RIDGE NATL LAB,DEPT MET & CERAM,OAK RIDGE,TN 37831. RP CAO, SQ (reprint author), UNIV TENNESSEE,DEPT MAT SCI & ENGN,KNOXVILLE,TN 37996, USA. NR 13 TC 22 Z9 22 U1 1 U2 8 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 DEC 5 PY 1994 VL 65 IS 23 BP 2940 EP 2942 DI 10.1063/1.112960 PG 3 WC Physics, Applied SC Physics GA PV093 UT WOS:A1994PV09300014 ER PT J AU FRANCESCHETTI, A ZUNGER, A AF FRANCESCHETTI, A ZUNGER, A TI PRESSURE-DEPENDENCE OF OPTICAL-TRANSITIONS IN ORDERED GAP INP SUPERLATTICES SO APPLIED PHYSICS LETTERS LA English DT Article ID ABSORPTION; (GA,IN)P RP FRANCESCHETTI, A (reprint author), NATL RENEWABLE ENERGY LAB,GOLDEN,CO 80401, USA. RI Zunger, Alex/A-6733-2013 NR 15 TC 10 Z9 10 U1 0 U2 0 PU AMER INST PHYSICS PI WOODBURY PA CIRCULATION FULFILLMENT DIV, 500 SUNNYSIDE BLVD, WOODBURY, NY 11797-2999 SN 0003-6951 J9 APPL PHYS LETT JI Appl. Phys. Lett. PD DEC 5 PY 1994 VL 65 IS 23 BP 2990 EP 2992 DI 10.1063/1.112486 PG 3 WC Physics, Applied SC Physics GA PV093 UT WOS:A1994PV09300031 ER PT J AU KIM, MW RUSSELL, TP MOSES, T CHEN, W SHEN, YR AF KIM, MW RUSSELL, TP MOSES, T CHEN, W SHEN, YR TI DIBLOCK COPOLYMER ADSORPTION ONTO A SOLID-SURFACE AS REVEALED BY EVANESCENT-WAVE ELLIPSOMETRY SO MACROMOLECULES LA English DT Note ID BLOCK COPOLYMERS; MICA; INTERFACE; SOLVENT; TOLUENE; OXIDE) C1 IBM CORP,ALMADEN RES CTR,DIV RES,SAN JOSE,CA 95120. UNIV CALIF BERKELEY,DEPT PHYS,BERKELEY,CA 94720. UNIV CALIF BERKELEY,LAWRENCE BERKELEY LAB,CTR ADV MAT,BERKELEY,CA 94720. RP KIM, MW (reprint author), EXXON RES & ENGN CO,ROUTE 22 E,ANNANDALE,NJ 08801, USA. RI Kim, Mahn Won/C-1541-2011 NR 12 TC 0 Z9 0 U1 0 U2 1 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 SN 0024-9297 J9 MACROMOLECULES JI Macromolecules PD DEC 5 PY 1994 VL 27 IS 25 BP 7490 EP 7491 DI 10.1021/ma00103a037 PG 2 WC Polymer Science SC Polymer Science GA PW059 UT WOS:A1994PW05900037 ER PT J AU BARDAKCI, K AF BARDAKCI, K TI THE CONFORMAL POINTS OF THE GENERALIZED THIRRING MODEL SO NUCLEAR PHYSICS B LA English DT Article ID 2 DIMENSIONS; INVARIANCE; FIELDS AB The conformal fixed points of the generalized Thirring model are investigated with the help of bosonization, the large-hr limit and the operator product expansion. Necessary conditions on the coupling constants for conformal invariance are derived. RP BARDAKCI, K (reprint author), UNIV CALIF BERKELEY,LAWRENCE BERKELEY LAB,THEORET PHYS GRP,BERKELEY,CA 94720, USA. NR 23 TC 6 Z9 6 U1 0 U2 1 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0550-3213 J9 NUCL PHYS B JI Nucl. Phys. B PD DEC 5 PY 1994 VL 431 IS 1-2 BP 191 EP 205 DI 10.1016/0550-3213(94)90103-1 PG 15 WC Physics, Particles & Fields SC Physics GA PV291 UT WOS:A1994PV29100007 ER PT J AU MONTOYA, CP LYNCH, WG BOWMAN, DR PEASLEE, GF CARIN, N DESOUZA, RT GELBKE, CK GONG, WG KIM, YD LISA, MA PHAIR, L TSANG, MB WEBSTER, JB WILLIAMS, C COLONNA, N HANOLD, K MCMAHAN, MA WOZNIAK, GJ MORETTO, LG AF MONTOYA, CP LYNCH, WG BOWMAN, DR PEASLEE, GF CARIN, N DESOUZA, RT GELBKE, CK GONG, WG KIM, YD LISA, MA PHAIR, L TSANG, MB WEBSTER, JB WILLIAMS, C COLONNA, N HANOLD, K MCMAHAN, MA WOZNIAK, GJ MORETTO, LG TI FRAGMENTATION OF NECKLIKE STRUCTURES SO PHYSICAL REVIEW LETTERS LA English DT Article ID NUCLEAR LATTICE MODEL; GAS PHASE-TRANSITION; EMISSION; MULTIFRAGMENTATION; FISSION; ARRAY C1 MICHIGAN STATE UNIV,DEPT PHYS & ASTRON,E LANSING,MI 48824. UNIV CALIF BERKELEY,LAWRENCE BERKELEY LAB,DIV NUCL SCI,BERKELEY,CA 94720. UNIV CALIF BERKELEY,LAWRENCE BERKELEY LAB,DIV ACCELERATOR & FUS RES,BERKELEY,CA 94720. RP MONTOYA, CP (reprint author), MICHIGAN STATE UNIV,NATL SUPERCONDUCTING CYCLOTRON LAB,E LANSING,MI 48824, USA. RI Lynch, William/I-1447-2013; deSouza, Romualdo/P-5862-2015 OI Lynch, William/0000-0003-4503-176X; deSouza, Romualdo/0000-0001-5835-677X NR 22 TC 119 Z9 120 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 DEC 5 PY 1994 VL 73 IS 23 BP 3070 EP 3073 DI 10.1103/PhysRevLett.73.3070 PG 4 WC Physics, Multidisciplinary SC Physics GA PV018 UT WOS:A1994PV01800007 ER PT J AU WEI, J LI, XP SESSLER, AM AF WEI, J LI, XP SESSLER, AM TI LOW-ENERGY STATES OF CIRCULATING STORED ION-BEAMS - CRYSTALLINE BEAMS SO PHYSICAL REVIEW LETTERS LA English DT Article ID STORAGE-RING C1 RUTGERS STATE UNIV,PISCATAWAY,NJ 08855. UNIV CALIF BERKELEY,LAWRENCE BERKELEY LAB,BERKELEY,CA 94720. RP WEI, J (reprint author), BROOKHAVEN NATL LAB,UPTON,NY 11973, USA. NR 12 TC 54 Z9 54 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 DEC 5 PY 1994 VL 73 IS 23 BP 3089 EP 3092 DI 10.1103/PhysRevLett.73.3089 PG 4 WC Physics, Multidisciplinary SC Physics GA PV018 UT WOS:A1994PV01800012 ER PT J AU MIKAELIAN, KO AF MIKAELIAN, KO TI QUANTITATIVE THEORY OF RICHTMYER-MESHKOV INSTABILITY - COMMENT SO PHYSICAL REVIEW LETTERS LA English DT Note RP MIKAELIAN, KO (reprint author), LAWRENCE LIVERMORE NATL LAB,LIVERMORE,CA 94550, USA. NR 6 TC 3 Z9 3 U1 2 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 DEC 5 PY 1994 VL 73 IS 23 BP 3177 EP 3177 DI 10.1103/PhysRevLett.73.3177 PG 1 WC Physics, Multidisciplinary SC Physics GA PV018 UT WOS:A1994PV01800034 ER PT J AU GROVE, JW HOLMES, R SHARP, DH YANG, YM ZHANG, Q AF GROVE, JW HOLMES, R SHARP, DH YANG, YM ZHANG, Q TI QUANTITATIVE THEORY OF RICHTMYER-MESHKOV INSTABILITY - REPLY SO PHYSICAL REVIEW LETTERS LA English DT Note C1 LOS ALAMOS NATL LAB,DIV THEORET,COMPLEX SYST GRP,LOS ALAMOS,NM 87545. RP GROVE, JW (reprint author), SUNY STONY BROOK,DEPT APPL MATH & STAT,STONY BROOK,NY 11794, USA. NR 3 TC 2 Z9 2 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 DEC 5 PY 1994 VL 73 IS 23 BP 3178 EP 3178 DI 10.1103/PhysRevLett.73.3178 PG 1 WC Physics, Multidisciplinary SC Physics GA PV018 UT WOS:A1994PV01800035 ER PT J AU MA, YJ AF MA, YJ TI STRUCTURE DETERMINATION USING X-RAY-FLUORESCENCE INTERFEROMETRY SO CHEMICAL PHYSICS LETTERS LA English DT Article ID SCATTERING AB The possibility of structure determination using the interference of fluorescence X-rays excited with monochromatic X-rays is investigated. The principle of this technique is the resonant inelastic scattering approach to the X-ray absorption-emission problem. Using a model calculation, we found that it is possible to determine the interatomic distances between two interacting identical atoms to a few percent of the wavelength of the X-ray. This technique can be applied to randomly oriented samples due to alignment by the polarization of the photons. C1 UNIV WASHINGTON, DEPT PHYS, SEATTLE, WA 98195 USA. PACIFIC NW LAB, RICHLAND, WA 99351 USA. NR 17 TC 7 Z9 7 U1 0 U2 1 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0009-2614 J9 CHEM PHYS LETT JI Chem. Phys. Lett. PD DEC 2 PY 1994 VL 230 IS 4-5 BP 451 EP 455 DI 10.1016/0009-2614(94)01176-1 PG 5 WC Chemistry, Physical; Physics, Atomic, Molecular & Chemical SC Chemistry; Physics GA PV065 UT WOS:A1994PV06500020 ER PT J AU FERNANDEZPINAS, F WOLK, CP AF FERNANDEZPINAS, F WOLK, CP TI EXPRESSION OF LUXCD-E IN ANABAENA SP CAN REPLACE THE USE OF EXOGENOUS ALDEHYDE FOR IN-VIVO LOCALIZATION OF TRANSCRIPTION BY LUXAB SO GENE LA English DT Note DE LUCIFERASE OPERON; ALDEHYDE BIOSYNTHETIC GENES; CYANOBACTERIUM; HETR ID NUCLEOTIDE-SEQUENCE; VIBRIO-HARVEYI; PHOTOBACTERIUM-LEIOGNATHI; BACTERIAL BIOLUMINESCENCE; FILAMENTOUS CYANOBACTERIA; HETEROCYST DEVELOPMENT; STRUCTURAL GENES; ESCHERICHIA-COLI; CLONING; VECTORS AB The genes luxCDABE from four luminescent bacteria suffice for light production in Escherichia coli [Meighen, Microbiol, Rev, 55 (1991) 123-142]. We have inserted these gene clusters between inverted polylinkers, and placed the resulting cassettes as reporters within derivatives of transposon Tn5. Anabaena sp. strain PCC 7120 was mutagenized with these transposons. The luminescence of al but the most highly self-luminescent resulting derivatives of Anabaena sp. was strongly dependent on exogenously added aldehyde. Thus, luminescence based on luxCDABE is multiplicatively limited by production of luciferase and aldehyde. No toxicity was observed over protracted periods of luminescence. By deletion, new cassettes were derived in which only the aldehyde biosynthetic genes, luxCD-E, remained intact. Transcription was localized at the single-cell level in strains of cyanobacteria bearing constitutively expressed Xenorhabdus luminescens luxCD-E on a plasmid and relatively weakly expressed, developmentally regulated luxAB from Vibrio spp. in the chromosome. The developmentally critical gene, hetR, was thereby shown to remain active in mature heterocysts. C1 MICHIGAN STATE UNIV,US DOE,PLANT RES LAB,E LANSING,MI 48824. OI Fernandez-Pinas, Francisca/0000-0002-7444-7601 NR 29 TC 34 Z9 34 U1 0 U2 3 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0378-1119 J9 GENE JI Gene PD DEC 2 PY 1994 VL 150 IS 1 BP 169 EP 174 DI 10.1016/0378-1119(94)90879-6 PG 6 WC Genetics & Heredity SC Genetics & Heredity GA PV421 UT WOS:A1994PV42100030 PM 7959046 ER PT J AU GOLDHABER, M AF GOLDHABER, M TI FIGHTING ANTIBIOTIC-RESISTANCE SO SCIENCE LA English DT Letter RP GOLDHABER, M (reprint author), BROOKHAVEN NATL LAB,DEPT PHYS,UPTON,NY 11973, USA. NR 4 TC 3 Z9 3 U1 0 U2 1 PU AMER ASSOC ADVANCEMENT SCIENCE PI WASHINGTON PA 1200 NEW YORK AVE, NW, WASHINGTON, DC 20005 USA SN 0036-8075 J9 SCIENCE JI Science PD DEC 2 PY 1994 VL 266 IS 5190 BP 1462 EP 1462 DI 10.1126/science.7985006 PG 1 WC Multidisciplinary Sciences SC Science & Technology - Other Topics GA PV015 UT WOS:A1994PV01500004 PM 7985006 ER PT J AU YEUNG, ES AF YEUNG, ES TI CHEMICAL-ANALYSIS OF SINGLE HUMAN ERYTHROCYTES SO ACCOUNTS OF CHEMICAL RESEARCH LA English DT Review ID CAPILLARY ZONE ELECTROPHORESIS; LASER-INDUCED FLUORESCENCE; LIQUID-CHROMATOGRAPHY; QUANTITATIVE-DETERMINATION; GEL-ELECTROPHORESIS; NATIVE PROTEINS; SENSITIVITY; RHODAMINE-6G; OPTIMIZATION; SEPARATIONS C1 US DOE,AMES LAB,AMES,IA 50011. RP YEUNG, ES (reprint author), IOWA STATE UNIV SCI & TECHNOL,FAC CHEM,DEPT CHEM,AMES,IA 50011, USA. NR 51 TC 41 Z9 42 U1 0 U2 2 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 SN 0001-4842 J9 ACCOUNTS CHEM RES JI Accounts Chem. Res. PD DEC PY 1994 VL 27 IS 12 BP 409 EP 414 DI 10.1021/ar00048a004 PG 6 WC Chemistry, Multidisciplinary SC Chemistry GA PW719 UT WOS:A1994PW71900004 ER PT J AU GAO, Q WEBER, HP CRAVEN, BM MCMULLAN, RK AF GAO, Q WEBER, HP CRAVEN, BM MCMULLAN, RK TI STRUCTURE OF SUBERIC ACID AT 18.4, 75 AND 123 K FROM NEUTRON-DIFFRACTION DATA SO ACTA CRYSTALLOGRAPHICA SECTION B-STRUCTURAL SCIENCE LA English DT Article ID THERMAL-MOTION; VIBRATIONS; BOND AB Neutron diffraction data for suberic acid [HOOC(CH2)(6)COOH] were collected at 18.4, 75 and 123 K using a twinned crystal. The neutron data reduction included derivation of a complete set of corrected intensities, as if from a single crystal. This was followed by full-matrix structure refinement in the usual way. The molecule has an almost fully extended conformation with the hydrocarbon chains packed in an orthorhombic mode. Molecules form infinite hydrogen-bonded chains with crystallographic inversion centers occuring at the center and at the ends of each molecule. We suggest that at the twin boundary the hydrogen bonding is different, involving only the hydroxyl groups as both donors and accepters. Accurate bond lengths have been obtained with corrections for thermal vibration (harmonic for C-C, C-O; harmonic and anharmonic for C-H). Values at the three temperatures agree well in terms of their e.s.d.'s (0.001 Angstrom for C-C and C-O and 0.005 Angstrom for C-H). Similar agreement is obtained for the corrected bond angles (e.s.d.'s 0.1 degrees for C-C-C, 0.2 degrees for H-C-H). For the methylene groups, the observed m.s, displacement parameters at each temperature are significantly greater at the middle of the molecule than at the ends. This indicates that the molecular backbone is vibrating internally. The thermal vibrations of the molecule have been analysed in terms of a simple segmented body model. C1 UNIV PITTSBURGH,DEPT CRYSTALLOG,PITTSBURGH,PA 15260. BROOKHAVEN NATL LAB,DEPT CHEM,UPTON,NY 11973. FU NHLBI NIH HHS [HL-20350] NR 30 TC 27 Z9 27 U1 0 U2 0 PU MUNKSGAARD INT PUBL LTD PI COPENHAGEN PA 35 NORRE SOGADE, PO BOX 2148, DK-1016 COPENHAGEN, DENMARK SN 0108-7681 J9 ACTA CRYSTALLOGR B JI Acta Crystallogr. Sect. B-Struct. Commun. PD DEC 1 PY 1994 VL 50 BP 695 EP 703 DI 10.1107/S0108768194003599 PN 6 PG 9 WC Chemistry, Multidisciplinary; Crystallography SC Chemistry; Crystallography GA PW461 UT WOS:A1994PW46100010 PM 7840917 ER PT J AU SELITSER, SI MORRIS, JW AF SELITSER, SI MORRIS, JW TI SUBSTRUCTURE FORMATION DURING PLASTIC-DEFORMATION SO ACTA METALLURGICA ET MATERIALIA LA English DT Article ID DISLOCATION PATTERN-FORMATION; DEFORMED METAL CRYSTALS; MECHANISM AB This work addresses cell formation from an initially homogeneous distribution of parallel edge dislocations. We consider an array of interacting, nearly parallel edge dislocations that glide on a single plane, but may also climb. We obtain a set of nonlinear differential equations that describe the evolution of the dislocation distribution, and find the instability conditions that lead toward cells. Three particularly interesting results emerge. First, the distribution of edge dislocations is always at least mathematically unstable with respect to cell formation when dislocations can be created or destroyed. Second, the locus of that instability is very sensitive to the efficiency of the dislocation creation mechanisms. Third, both relatively equiaxed and highly elongated cells may form, depending on the temperature and the ratio of the stresses that drive glide and climb. C1 LAWRENCE BERKELEY LAB, CTR ADV MAT, BERKELEY, CA 94720 USA. RP SELITSER, SI (reprint author), UNIV CALIF BERKELEY, DEPT MAT SCI, BERKELEY, CA 94720 USA. NR 20 TC 5 Z9 5 U1 0 U2 0 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 DEC PY 1994 VL 42 IS 12 BP 3985 EP 3991 DI 10.1016/0956-7151(94)90175-9 PG 7 WC Materials Science, Multidisciplinary; Metallurgy & Metallurgical Engineering SC Materials Science; Metallurgy & Metallurgical Engineering GA PQ619 UT WOS:A1994PQ61900006 ER PT J AU MCHUGH, PR KNOLL, DA AF MCHUGH, PR KNOLL, DA TI COMPARISON OF STANDARD AND MATRIX-FREE IMPLEMENTATIONS OF SEVERAL NEWTON-KRYLOV SOLVERS SO AIAA JOURNAL LA English DT Article ID NONSYMMETRIC LINEAR-SYSTEMS; NAVIER-STOKES EQUATIONS; MINIMAL RESIDUAL ALGORITHM; CONJUGATE-GRADIENT METHODS; ITERATIVE SOLUTION; CONVECTION AB Fully coupled Newton's method is combined with conjugate gradient-like iterative algorithms to form inexact Newton-Krylov algorithms for solving the steady, incompressible, Navier-Stokes and energy equations in primitive variables. Finite volume differencing is employed using the power law convection-diffusion scheme on a uniform but staggered mesh. The well-known model problem of natural convection in an enclosed cavity is solved. Three conjugate gradient-like algorithms are selected from a class of algorithms based upon the Lanczos biorthogonalization procedure; namely, the conjugate gradients squared algorithm, the transpose-free quasi-minimal-residual algorithm, and a more smoothly convergent version of the biconjugate gradients algorithm. A fourth algorithm is based upon the Arnoldi process, namely the popular generalized minimal residual algorithm (GMRES). The performance of a standard inexact Newton's method implementation is compared with a matrix-free implementation. Results indicate that the performance of the matrix-free implementation is strongly dependent upon grid size (number of unknowns) and the selection of the conjugate gradient-like method. GMRES appeared to be superior to the Lanczos based algorithms within the context of a matrix-free implementation. C1 LOCKHEED IDAHO TECHNOL CO,IDAHO NATL ENGN UB,DEPT ENGN ANAL,IDAHO FALLS,ID 83415. NR 29 TC 31 Z9 32 U1 0 U2 0 PU AMER INST AERONAUT ASTRONAUT PI RESTON PA 1801 ALEXANDER BELL DRIVE, STE 500, RESTON, VA 22091 SN 0001-1452 J9 AIAA J JI AIAA J. PD DEC PY 1994 VL 32 IS 12 BP 2394 EP 2400 DI 10.2514/3.12305 PG 7 WC Engineering, Aerospace SC Engineering GA QB301 UT WOS:A1994QB30100009 ER PT J AU ROBINSON, SM ARNOLD, WD BYERS, CH AF ROBINSON, SM ARNOLD, WD BYERS, CH TI MASS-TRANSFER MECHANISMS FOR ZEOLITE ION-EXCHANGE IN WASTE-WATER TREATMENT SO AICHE JOURNAL LA English DT Article ID ACTIVATED CARBON; FIXED-BEDS; MULTICOMPONENT ADSORPTION; NUMERICAL-SIMULATION; ORGANIC-COMPOUNDS; DIFFUSION CONTROL; MOLECULAR-SIEVES; MODEL; TRANSPORT; SYSTEMS AB In spite of the increasing commercial use of zeolites for binary and multicomponent ion exchange, understanding of the basic mass-transfer processes associated with multicomponent zeolite systems is quite limited. This study evaluates Na-Ca-Mg-Cs-Sr ion exchange from an aqueous solution using a chabazite zeolite. Mass-transfer coefficients are determined from experimental batch-reactor data for binary and multicomponent systems. The experimental data indicate that diffusion through the microporous zeolite crystals is the primary diffusional resistance. Macropore diffusion also significantly contributes to the mass-transfer resistance. Various mass-transfer models are compared with the experimental data to determine values for intraparticle diffusivities. Effective diffusivities obtained accurately predict experimental data using a variety of models. Only the model accounting for micropore and macropore diffusion occurring in series accurately predict multicomponent data using diffusivities from the binary system. Liquid and surface diffusion both contribute to macropore diffusion. Surface and micropore diffusivities are concentration-dependent for the system of interest. RP ROBINSON, SM (reprint author), OAK RIDGE NATL LAB,OAK RIDGE,TN 37831, USA. NR 62 TC 56 Z9 56 U1 1 U2 3 PU AMER INST CHEMICAL ENGINEERS PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 SN 0001-1541 J9 AICHE J JI AICHE J. PD DEC PY 1994 VL 40 IS 12 BP 2045 EP 2054 DI 10.1002/aic.690401214 PG 10 WC Engineering, Chemical SC Engineering GA PX271 UT WOS:A1994PX27100013 ER PT J AU CHEN, PC AF CHEN, PC TI HEURISTIC SAMPLING ON DAGS SO ALGORITHMICA LA English DT Article DE HEURISTICS; SAMPLING; COST PREDICTION; MONTE-CARLO METHOD; ANALYSIS OF ALGORITHMS ID PROGRAMS AB In theory, many problems in computer applications can be solved by searching through a directed-acyclic graph (DAG). In practice, however, this approach has been hampered by our analytical inability to predict the search cost accurately without actually implementing and executing the program. To overcome this inability, a simple and quick heuristic procedure based on a stratified sampling approach is presented. It generalizes a tree sampling technique already shown to be useful in predicting the performance of tree-searching programs. With the addition of this DAG sampling procedure, we should be able to forecast the complexity and feasibility of alternative tree or DAG searching algorithms so that we may utilize our computational resources more effectively. RP CHEN, PC (reprint author), SANDIA NATL LABS,POB 5800,ALBUQUERQUE,NM 87185, USA. NR 8 TC 0 Z9 0 U1 0 U2 0 PU SPRINGER VERLAG PI NEW YORK PA 175 FIFTH AVE, NEW YORK, NY 10010 SN 0178-4617 J9 ALGORITHMICA JI Algorithmica PD DEC PY 1994 VL 12 IS 6 BP 458 EP 475 DI 10.1007/BF01188715 PG 18 WC Computer Science, Software Engineering; Mathematics, Applied SC Computer Science; Mathematics GA PJ031 UT WOS:A1994PJ03100003 ER PT J AU SHAPOURI, H AF SHAPOURI, H TI NET ENERGY VALUE OF ETHANOL SO AMERICAN JOURNAL OF AGRICULTURAL ECONOMICS LA English DT Meeting Abstract C1 US DOE,WASHINGTON,DC 20545. NR 0 TC 0 Z9 0 U1 0 U2 0 PU AMER AGR ECON ASSN PI AMES PA IOWA STATE UNIV 80 HEADY HALL, AMES, IA 50011-1070 SN 0002-9092 J9 AM J AGR ECON JI Am. J. Agr. Econ. PD DEC PY 1994 VL 76 IS 5 BP 1274 EP 1275 PG 2 WC Agricultural Economics & Policy; Economics SC Agriculture; Business & Economics GA QG032 UT WOS:A1994QG03200410 ER PT J AU FURMAN, MA AF FURMAN, MA TI COMPACT COMPLEX EXPRESSIONS FOR THE ELECTRIC-FIELD OF 2-DIMENSIONAL ELLIPTIC CHARGE-DISTRIBUTIONS SO AMERICAN JOURNAL OF PHYSICS LA English DT Article AB We present a formula for the analytic calculation of the electric field in complex form for two-dimensional charge distributions with elliptical contours, in the absence of boundary conditions except at infinity. The formula yields compact and practical expressions for a significant class of distributions. The fact that the electric field vanishes inside an elliptical shell follows as a straightforward consequence of Cauchy's theorem. The known expressions for the field inside and outside a uniformly charged ellipse are recovered in simple, concise form. Similarly, the expression for the field of a Gaussian distribution is found in a straightforward way as a special case of the more general formula. We also present a brief discussion of more complicated distributions. RP FURMAN, MA (reprint author), UNIV CALIF BERKELEY,LAWRENCE BERKELEY LAB,CTR BEAM PHYS,DIV ACCELERATOR & FUS RES,MS 71-259,BERKELEY,CA 94720, USA. NR 16 TC 10 Z9 10 U1 0 U2 0 PU AMER INST PHYSICS PI WOODBURY PA CIRCULATION FULFILLMENT DIV, 500 SUNNYSIDE BLVD, WOODBURY, NY 11797-2999 SN 0002-9505 J9 AM J PHYS JI Am. J. Phys. PD DEC PY 1994 VL 62 IS 12 BP 1134 EP 1140 DI 10.1119/1.17674 PG 7 WC Education, Scientific Disciplines; Physics, Multidisciplinary SC Education & Educational Research; Physics GA PU622 UT WOS:A1994PU62200018 ER PT J AU HUSTON, MA DEANGELIS, DL AF HUSTON, MA DEANGELIS, DL TI COMPETITION AND COEXISTENCE - THE EFFECTS OF RESOURCE TRANSPORT AND SUPPLY RATES SO AMERICAN NATURALIST LA English DT Review ID DIFFERENT IRRADIANCE LEVELS; PINUS-TAEDA SEEDLINGS; VARIABLE ENVIRONMENT; LIQUIDAMBAR-STYRACIFLUA; HERBACEOUS VEGETATION; REGIONAL COEXISTENCE; POPULATION-DYNAMICS; SPECIES-DIVERSITY; PLANT-COMMUNITIES; ECOLOGICAL MODELS AB Classical resource competition theory can be generalized to apply to a variety of specific resource types and specific supply media (e.g., soil, water, or air). We develop a general model that relaxes the assumptions that (1) resources and organisms are sufficiently mixed that all organisms experience the same resource concentration and (2) the organisms themselves regulate the resource concentration of their shared environment. These assumptions are shown to apply to a limited subset of conditions in which the resource input rate is low and the resource transport rate in the environment is high. Under such conditions, the coexistence criteria of our general model converge with those of classical resource competition models. Such conditions may be met in some aquatic environments, but under other conditions, in which resource transport rates may be low or input fluxes high, the general model makes predictions that differ radically from those of the classical models. Specifically, our model predicts that, instead of a 1:1 ratio between limiting resources and locally coexisting species, a large number of species can coexist on a single limiting resource under steady-state conditions. Shifts from limitation by one type of resource to limitation by another type can dramatically alter the nature and intensity of competitive interactions. This phenomenon is proposed as the explanation for the ubiquitous unimodel curve of autotroph diversity along productivity gradients. RP OAK RIDGE NATL LAB, DIV ENVIRONM SCI, POB 2008, OAK RIDGE, TN 37831 USA. RI Huston, Michael/B-1434-2009; Carneiro, Fernanda/E-9513-2013 OI Huston, Michael/0000-0001-9513-1166; Carneiro, Fernanda/0000-0001-6389-4564 NR 120 TC 251 Z9 266 U1 8 U2 82 PU UNIV CHICAGO PRESS PI CHICAGO PA 1427 E 60TH ST, CHICAGO, IL 60637-2954 USA SN 0003-0147 EI 1537-5323 J9 AM NAT JI Am. Nat. PD DEC PY 1994 VL 144 IS 6 BP 954 EP 977 DI 10.1086/285720 PG 24 WC Ecology; Evolutionary Biology SC Environmental Sciences & Ecology; Evolutionary Biology GA PW450 UT WOS:A1994PW45000005 ER PT J AU JACOBSON, SC HERGENRODER, R MOORE, AW RAMSEY, JM AF JACOBSON, SC HERGENRODER, R MOORE, AW RAMSEY, JM TI PRECOLUMN REACTIONS WITH ELECTROPHORETIC ANALYSIS INTEGRATED ON A MICROCHIP SO ANALYTICAL CHEMISTRY LA English DT Article ID CAPILLARY ZONE ELECTROPHORESIS; ORTHO-PHTHALDIALDEHYDE; AMINO-ACIDS; FLUORESCENCE DETECTION; SAMPLE INJECTION; CHIP; DERIVATIZATION; SYSTEMS AB A glass microchip was constructed to perform chemical reactions and capillary electrophoresis sequentially. The channel manifold on the glass substrate was fabricated using standard photolithographic, etching, and deposition techniques. The microchip has a reaction chamber with a 1 nL reaction volume and a separation column with a 15.4 mm separation length. Electrical control of the buffer, analyte, and reagent streams made possible the precise manipulation of the fluids within the channel manifold. The microchip was operated under a continuous reaction mode with gated injections to introduce the reaction product onto the separation column with high reproducibility (<1.8% rsd in peak area). The reaction and separation performances were evaluated by reacting amino acids with o-phthaldialdehyde to generate a fluorescent product which was detected by laser-induced fluorescence. Control of the reaction and separation conditions was sufficient to measure reaction kinetics and variation of detection limits with reaction time. Half-times of reaction of 5.1 and 6.2 s and detection limits of 0.55 and 0.83 fmol were measured for arginine and glycine, respectively. C1 OAK RIDGE NATL LAB,DIV CHEM & ANALYT SCI,OAK RIDGE,TN 37831. RI Kipke, Daryl/A-2167-2009 NR 20 TC 286 Z9 287 U1 1 U2 32 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 SN 0003-2700 J9 ANAL CHEM JI Anal. Chem. PD DEC 1 PY 1994 VL 66 IS 23 BP 4127 EP 4132 DI 10.1021/ac00095a003 PG 6 WC Chemistry, Analytical SC Chemistry GA PU984 UT WOS:A1994PU98400006 ER PT J AU BARSHICK, CM SHAW, RW YOUNG, JP RAMSEY, JM AF BARSHICK, CM SHAW, RW YOUNG, JP RAMSEY, JM TI ISOTOPIC ANALYSIS OF URANIUM USING GLOW-DISCHARGE OPTOGALVANIC SPECTROSCOPY AND DIODE-LASERS SO ANALYTICAL CHEMISTRY LA English DT Article ID MASS-SPECTROMETRY; SAMPLES; UI AB A hollow cathode glow discharge has been coupled with tunable lasers for isotopically selective excitation of gaseous uranium atoms produced by cathodic sputtering. A CW argon ion laser-pumped titanium:sapphire ring laser and a semiconductor diode laser were employed. Optogalvanic detection of the discharge atom population allowed identification of U-235 at depleted, natural, and enriched abundances in uranium metal and uranium oxide samples based on the spectral signatures of two transitions. Isotope ratio measurements were precise from run to run (internal precision) to better than +/-1% relative standard deviation at 1 sigma; external precision (sample to sample) was on the order of +/-3% relative standard deviation at 1 sigma. As in mass spectrometry, the most accurate analysis will be obtained when a bias correction is employed to correct for day to day variations in the laser and discharge conditions. RP BARSHICK, CM (reprint author), OAK RIDGE NATL LAB, DIV CHEM & ANALYT SCI, OAK RIDGE, TN 37831 USA. NR 27 TC 23 Z9 23 U1 1 U2 7 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 SN 0003-2700 J9 ANAL CHEM JI Anal. Chem. PD DEC 1 PY 1994 VL 66 IS 23 BP 4154 EP 4158 DI 10.1021/ac00095a007 PG 5 WC Chemistry, Analytical SC Chemistry GA PU984 UT WOS:A1994PU98400010 ER PT J AU DADACHOVA, E MIRZADEH, S LAMBRECHT, RM HETHERINGTON, EL KNAPP, FF AF DADACHOVA, E MIRZADEH, S LAMBRECHT, RM HETHERINGTON, EL KNAPP, FF TI SEPARATION OF CARRIER-FREE HO-166 FROM NEUTRON-IRRADIATED DYSPROSIUM TARGETS SO ANALYTICAL CHEMISTRY LA English DT Article ID RARE-EARTH ELEMENTS; CHROMATOGRAPHY; COMPLEXES; ACID AB Holmium-166 (Ho-166, t(1/2) = 26.4 h) is utilized in radiotherapeutic applications such as radioimmunospecific pharmaceuticals, bone marrow ablation, and radiation synovectomy. High specific activity Ho-166 can be obtained from the decay of dysprosium-166 (Dy-166, t(1/2) = 81.5 h). Dysprosium-166 is produced by the Dy-164[n,gamma]Dy-165[n,gamma]Dy-166 reaction in a nuclear reactor. The applicability of reversed phase ion-exchange chromatographic methods was demonstrated for the separation of carrier-free Ho-166 from milligram quantities of (Dy2O3)-Dy-164 irradiated targets. An efficient and quantitative separation was achieved utilizing a metal-free HPLC system with Dowex AG 50WX12 or Aminex-A5 cation exchangers and alpha-hydroxyisobutyric acid (alpha-MIBA) as the eluent (0.085 M, pH 4.3 adjusted with NH4OH). The Aminex-A5 column gave a separation factor of similar to 10(3) between Ho and Dy. Subsequent to the acidic destruction of the Ho-HIBA complex, Ho3+ was further purified on a small cation-exchange column from acidic chloride solutions. The separation was achieved within 2 h, with a 95% overall radiochemical yield for carrier-free Ho-166 with a DY breakthrough of <0.1%. C1 OAK RIDGE NATL LAB,NUCL MED GRP,OAK RIDGE,TN 37831. AUSTRALIAN NUCL SCI & TECHNOL ORG,BIOMED & HLTH PROGRAM,MENAI,NSW 2234,AUSTRALIA. RI Dadachova, Ekaterina/I-7838-2013 NR 30 TC 23 Z9 23 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 DEC 1 PY 1994 VL 66 IS 23 BP 4272 EP 4277 DI 10.1021/ac00095a024 PG 6 WC Chemistry, Analytical SC Chemistry GA PU984 UT WOS:A1994PU98400027 ER PT J AU HOFFMANNBENNING, S KLOMPARENS, KL KENDE, H AF HOFFMANNBENNING, S KLOMPARENS, KL KENDE, H TI CHARACTERIZATION OF GROWTH-RELATED OSMIOPHILIC PARTICLES IN CORN COLEOPTILES AND DEEP-WATER RICE INTERNODES SO ANNALS OF BOTANY LA English DT Article DE EPIDERMAL CELL WALL; GIBBERELLIN; INDOLEACETIC ACID; OSMIOPHILIC PARTICLES; ORYZA SATIVA; ZEA MAYS ID DEEP-WATER RICE; LIPID TRANSFER PROTEIN; PLANTS; WALL; GIBBERELLIN; EXPRESSION; GENE AB Osmiophilic particles are secreted from the epidermal cells into the outer epidermal cell wall of deepwater rice internodes and corn coleoptiles that have been induced to elongate rapidly by treatment with gibberellin or auxin, respectively. The diameter of the osmiophilic particles is 80 to 100 nm in deepwater rice and up to 300 nm in corn coleoptiles. Because these particles are secreted to the outer epidermal wall only, they may contain either cell wall components that are specific for the outer epidermal wall or components of the cuticle that coats the outer epidermal wall. Monensin inhibited the appearance of these particles, indicating that they are derived from the Golgi apparatus. An attempt was made to identify the contents of the osmiophilic particles by enzyme-gold or antibody-gold labelling. Cutinase-gold accumulated mostly in the region of the cell wall just below the cuticle. The osmiophilic particles became densely labelled after incubation with proteinase K-gold, indicating that they are, at least in part, proteinaceous. In excised tissue and ultrathin sections treated with proteinase K, the number of osmiophilic particles was reduced, while glucanase and cutinase treatments were without effect. Antibodies against lipid transfer protein, an extensin-like protein, an arabinogalactan protein, a peroxidase, and expansin bound to the cell wall or plasma membrane but not to the osmiophilic particles. C1 MICHIGAN STATE UNIV,US DOE,PLANT RES LAB,E LANSING,MI 48824. MICHIGAN STATE UNIV,DEPT BOT & PLANT PATHOL,E LANSING,MI 48824. NR 26 TC 37 Z9 38 U1 1 U2 5 PU ACADEMIC PRESS (LONDON) LTD PI LONDON PA 24-28 OVAL RD, LONDON, ENGLAND NW1 7DX SN 0305-7364 J9 ANN BOT-LONDON JI Ann. Bot. PD DEC PY 1994 VL 74 IS 6 BP 563 EP 572 DI 10.1006/anbo.1994.1156 PG 10 WC Plant Sciences SC Plant Sciences GA PY531 UT WOS:A1994PY53100001 ER PT J AU MYERS, G AF MYERS, G TI MOLECULAR INVESTIGATION OF HIV TRANSMISSION SO ANNALS OF INTERNAL MEDICINE LA English DT Editorial Material ID DENTAL PRACTICE RP MYERS, G (reprint author), LOS ALAMOS NATL LAB,HIV SEQUENCE DATABASE & ANAL PROJECT,POB 1663,LOS ALAMOS,NM 87545, USA. NR 11 TC 7 Z9 7 U1 0 U2 0 PU AMER COLL PHYSICIANS PI PHILADELPHIA PA INDEPENDENCE MALL WEST 6TH AND RACE ST, PHILADELPHIA, PA 19106-1572 SN 0003-4819 J9 ANN INTERN MED JI Ann. Intern. Med. PD DEC 1 PY 1994 VL 121 IS 11 BP 889 EP 890 PG 2 WC Medicine, General & Internal SC General & Internal Medicine GA PT628 UT WOS:A1994PT62800012 PM 7978704 ER PT J AU WILBANKS, TJ AF WILBANKS, TJ TI SUSTAINABLE DEVELOPMENT IN GEOGRAPHIC PERSPECTIVE SO ANNALS OF THE ASSOCIATION OF AMERICAN GEOGRAPHERS LA English DT Editorial Material DE GEOGRAPHY; GLOBAL CHANGE; INTEGRATED ASSESSMENT; SCALE; SUSTAINABLE DEVELOPMENT ID CLIMATE AB For geographers, both the seriousness of the sustainable development issue and the power of the term are challenges that are very welcome. The intellectual value and practical utility of such distinctive concepts as diversity, flow (nature-society, spatial, and temporal), scale, and visualization represent opportunities to contribute profoundly to questions of significance to both general learning and social decisionmaking. Moreover, geography's perspective can help to address the pressing need for a stronger theoretical basis for understanding sustainable development. In the end, however, our contributions will depend on a demonstration in our roles as teachers and citizens, as well as scholars, that we recognize the importance of an ethical revolution as well as increased scientific understanding. RP WILBANKS, TJ (reprint author), OAK RIDGE NATL LAB,OAK RIDGE,TN 37831, USA. NR 81 TC 57 Z9 61 U1 2 U2 4 PU BLACKWELL PUBLISHERS PI CAMBRIDGE PA 238 MAIN STREET, CAMBRIDGE, MA 02142 SN 0004-5608 J9 ANN ASSOC AM GEOGR JI Ann. Assoc. Am. Geogr. PD DEC PY 1994 VL 84 IS 4 BP 541 EP 556 DI 10.1111/j.1467-8306.1994.tb01876.x PG 16 WC Geography SC Geography GA QA066 UT WOS:A1994QA06600001 ER PT J AU RAYNER, S AF RAYNER, S TI SOCIAL SOLIDARITIES AND ENVIRONMENTAL SEPARATIONS SO ANNALS OF THE ASSOCIATION OF AMERICAN GEOGRAPHERS LA English DT Editorial Material RP RAYNER, S (reprint author), PACIFIC NW LAB, RICHLAND, WA 99352 USA. NR 10 TC 0 Z9 1 U1 0 U2 0 PU BLACKWELL PUBLISHERS PI CAMBRIDGE PA 238 MAIN STREET, CAMBRIDGE, MA 02142 SN 0004-5608 J9 ANN ASSOC AM GEOGR JI Ann. Assoc. Am. Geogr. PD DEC PY 1994 VL 84 IS 4 BP 715 EP 721 DI 10.1111/j.1467-8306.1994.tb01888.x PG 7 WC Geography SC Geography GA QA066 UT WOS:A1994QA06600013 ER PT J AU KITTS, CL CUNNINGHAM, DP UNKEFER, PJ AF KITTS, CL CUNNINGHAM, DP UNKEFER, PJ TI ISOLATION OF 3 HEXAHYDRO-1,3,5-TRINITRO-1,3,5-TRIAZINE-DEGRADING SPECIES OF THE FAMILY ENTEROBACTERIACEAE FROM NITRAMINE EXPLOSIVE-CONTAMINATED SOIL SO APPLIED AND ENVIRONMENTAL MICROBIOLOGY LA English DT Note ID ESCHERICHIA-COLI; NITROREDUCTASE; METABOLISM AB Three species of the family Enterobacteriaceae that biochemically reduced hexahydro- 1,3,5-trinitro-1,3,5-triazine (RDX) and octahydro-1,3,5,7-tetranitro-1,3,5,7-tetrazocine (HMX) were isolated from nitramine explosive-contaminated soil. Two isolates, identified as Morganella morganii and Providencin rettgeri, completely transformed both RDX and the nitroso-RDX reduction intermediates. The third isolate, identified as Citrobacter freundii, partially transformed RDX and generated high concentrations of nitroso-RDX intermediates. All three isolates produced (CO2)-C-14 from labeled RDX under O-2-depleted culture conditions. While all three isolates transformed HMX, only M. morganii transformed HMX in the presence of RDX. C1 LOS ALAMOS NATL LAB,LOS ALAMOS,NM 87545. NR 20 TC 107 Z9 109 U1 0 U2 8 PU AMER SOC MICROBIOLOGY PI WASHINGTON PA 1325 MASSACHUSETTS AVENUE, NW, WASHINGTON, DC 20005-4171 SN 0099-2240 J9 APPL ENVIRON MICROB JI Appl. Environ. Microbiol. PD DEC PY 1994 VL 60 IS 12 BP 4608 EP 4611 PG 4 WC Biotechnology & Applied Microbiology; Microbiology SC Biotechnology & Applied Microbiology; Microbiology GA PU399 UT WOS:A1994PU39900058 PM 7811097 ER PT J AU ENZIEN, MV PICARDAL, F HAZEN, TC ARNOLD, RG FLIERMANS, CB AF ENZIEN, MV PICARDAL, F HAZEN, TC ARNOLD, RG FLIERMANS, CB TI REDUCTIVE DECHLORINATION OF TRICHLOROETHYLENE AND TETRACHLOROETHYLENE UNDER AEROBIC CONDITIONS IN A SEDIMENT COLUMN (VOL 60, PG 2202, 1994) SO APPLIED AND ENVIRONMENTAL MICROBIOLOGY LA English DT Correction, Addition C1 UNIV ARIZONA,DEPT CIVIL ENGN,TUCSON,AZ 85721. RP ENZIEN, MV (reprint author), WESTINGHOUSE SAVANNAH RIVER CO,SAVANNAH RIVER TECHNOL CTR,AIKEN,SC 29802, USA. RI Hazen, Terry/C-1076-2012 OI Hazen, Terry/0000-0002-2536-9993 NR 1 TC 1 Z9 1 U1 1 U2 1 PU AMER SOC MICROBIOLOGY PI WASHINGTON PA 1325 MASSACHUSETTS AVENUE, NW, WASHINGTON, DC 20005-4171 SN 0099-2240 J9 APPL ENVIRON MICROB JI Appl. Environ. Microbiol. PD DEC PY 1994 VL 60 IS 12 BP 4646 EP 4646 PG 1 WC Biotechnology & Applied Microbiology; Microbiology SC Biotechnology & Applied Microbiology; Microbiology GA PU399 UT WOS:A1994PU39900069 ER PT J AU MARLEY, NA GAFFNEY, JS CUNNINGHAM, MM AF MARLEY, NA GAFFNEY, JS CUNNINGHAM, MM TI LAMBERT ABSORPTION-COEFFICIENTS OF WATER IN THE FREQUENCY-RANGE OF 3000-934-CM(-1) SO APPLIED OPTICS LA English DT Article DE LAMBERT ABSORPTION COEFFICIENTS; WATER; INFRARED; CYLINDRICAL INTERNAL REFLECTANCE ID OPTICAL-CONSTANTS; AEROSOLS; CLIMATE; CLOUDS AB Accurate values for the Lambert absorption coefficients of water have been determined in the atmospherically important frequency region of 3000-934 cm(-1) (3.333-10.707 mu m). These values were calculated at every 2 wave numbers from linear regression of 13 spectra obtained by using both transmission and internal reflection techniques with varying sample thicknesses. Correlation coefficients (R(2)) varied from 0.998 to 0.826 and estimated errors in the measured values ranged from 1% to 10%. Results are compared with those reported earlier from single measurements. RP MARLEY, NA (reprint author), ARGONNE NATL LAB,DIV ENVIRONM RES,ARGONNE,IL 60439, USA. NR 14 TC 5 Z9 6 U1 1 U2 4 PU OPTICAL SOC AMER PI WASHINGTON PA 2010 MASSACHUSETTS AVE NW, WASHINGTON, DC 20036 SN 0003-6935 J9 APPL OPTICS JI Appl. Optics PD DEC 1 PY 1994 VL 33 IS 34 BP 8041 EP 8054 PG 14 WC Optics SC Optics GA PZ823 UT WOS:A1994PZ82300028 PM 20963022 ER PT J AU PROCHNOW, E EDWARDS, DF SHUKLA, RP CHOI, J AGGARWAL, MD AF PROCHNOW, E EDWARDS, DF SHUKLA, RP CHOI, J AGGARWAL, MD TI THE PRECISION RELISHING OR BISMUTH SILICATE AND BISMUTH-GERMANATE SO APPLIED OPTICS LA English DT Note AB A recipe is given for the polishing of precise surfaces on crystals of bismuth silicate (BSO) and bismuth germanate (EGO). Using this recipe, crystals having surface figure better than 2/10 wave, roughness of 20-50 Angstrom rms, and laser quality parallelism (10 arcsec or better) were obtained with about 1-2 hours effort. C1 ALABAMA A&M UNIV,DEPT PHYS,NORMAL,AL 35762. RP PROCHNOW, E (reprint author), LAWRENCE LIVERMORE NATL LAB,OPT SCI & ENGN GRP,LIVERMORE,CA 94550, USA. NR 0 TC 1 Z9 1 U1 0 U2 1 PU OPTICAL SOC AMER PI WASHINGTON PA 2010 MASSACHUSETTS AVE NW, WASHINGTON, DC 20036 SN 0003-6935 J9 APPL OPTICS JI Appl. Optics PD DEC 1 PY 1994 VL 33 IS 34 BP 8101 EP 8102 PG 2 WC Optics SC Optics GA PZ823 UT WOS:A1994PZ82300037 PM 20963031 ER PT J AU KNAPP, FF CALLAHAN, AP BEETS, AL MIRZADEH, S HSIEH, BT AF KNAPP, FF CALLAHAN, AP BEETS, AL MIRZADEH, S HSIEH, BT TI PROCESSING OF REACTOR-PRODUCED W-188 FOR FABRICATION OF CLINICAL-SCALE ALUMINA-BASED W-188/RE-188 GENERATORS SO APPLIED RADIATION AND ISOTOPES LA English DT Article ID RE-188 AB The traditional technique for processing of reactor-irradiated W-186-enriched tungsten oxide (WO3) targets involves formation of W-188-sodium tungstate solutions by target dissolution in 0.1 M NaOH. Following long irradiations (>21 days) in the ORNL High Flux Isotope Reactor (HFIR) the (WO3)-W-186 targets contain a NaOH-insoluble W-188-labeled black solid (approx. 30-50% of total activity) which decreases the yield and specific activity of the processed W-188 (e.g. 5-6 mCi/mg W-186 for a 79-day irradiation). The black material is postulated to represent a ''tungsten blue'' insoluble polymeric form of tungsten oxide, which we have now found to dissolve in 0.1 M NaOH containing 5% sodium hypochlorite solution. Complete dissolution results in a significant increase in the yield and specific activity of sodium W-188-tungstate. As an alternative approach, irradiated W-186-enriched metal targets dissolve in sodium hydroxide solution by cautious addition of <30% hydrogen peroxide. Sodium W-188-tungstate solutions prepared from processing of such metal targets show no evidence of residual black insoluble material. Specific activity values for completely dissolved HFIR-irradiated W-186 targets have increased to 10 mCi/mg (43.5 days) and 12.9 mCi/mg (49.2 days). Large clinical scale (>1 Ci) generators prepared from hypochlorite-processed W-186 oxide or peroxide-processed W-186 metal targets exhibit the expected Re-188 high yield and low W-188 breakthrough. RP KNAPP, FF (reprint author), OAK RIDGE NATL LAB,DIV HLTH SCI RES,NUCL MED GRP,POB 2008,OAK RIDGE,TN 37830, USA. NR 24 TC 92 Z9 92 U1 1 U2 2 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD, ENGLAND OX5 1GB SN 0969-8043 J9 APPL RADIAT ISOTOPES JI Appl. Radiat. Isot. PD DEC PY 1994 VL 45 IS 12 BP 1123 EP 1128 DI 10.1016/0969-8043(94)90026-4 PG 6 WC Chemistry, Inorganic & Nuclear; Nuclear Science & Technology; Radiology, Nuclear Medicine & Medical Imaging SC Chemistry; Nuclear Science & Technology; Radiology, Nuclear Medicine & Medical Imaging GA QE683 UT WOS:A1994QE68300001 ER PT J AU FERRIERI, RA ALEXOFF, DL SCHLYER, DJ WOLF, AP AF FERRIERI, RA ALEXOFF, DL SCHLYER, DJ WOLF, AP TI REMOTE PROCESSING, DELIVERY AND INJECTION OF H-2[O-15] PRODUCED FROM A N-2/H-2 GAS-TARGET USING A SIMPLE AND COMPACT APPARATUS SO APPLIED RADIATION AND ISOTOPES LA English DT Article ID CEREBRAL BLOOD-FLOW; POSITRON EMISSION TOMOGRAPHY; QUANTITATIVE MEASUREMENT; OXYGEN-15-LABELED WATER; O-15; INFUSION; OXYGEN; SYSTEM AB We report here a simple apparatus for remote trapping and processing of H-2[O-15] produced from the N-2/H-2 target. The system performs a three step operation for H-2[O-15] delivery at the PET imaging facility which includes the following: (i) collecting the radiotracer in sterile water; (ii) adjusting preparation pH through removal of radiolytically produced ammonia, while at the same time adjusting solution isotonicity; and (iii) delivery of the radiotracer preparation to the injection syringe in a sterile and pyrogen-free form suitable for human studies. The processing apparatus is simple, can be remotely operated and fits inside a Capintec Dose Monitoring Chamber for direct measurement of accumulated radioactivity. Using this system, 300 mCi of H-2[O-15] (15 mu A of 8 MeV D+ on target) is transferred from target through 120 m x 3.18 mm o.d. Impolene tubing to yield 100 mCi of H-2[O-15] which is isotonic, neutral and suitable for human studies. A remote hydraulically driven system for i.v. injection of the H-2[O-15] is also described. The device allows for direct measurement of syringe dose while filling, and for easy, as well as safe transport of the injection syringe assembly to the patient's bedside via a shielded delivery cart. This cart houses a hydraulic piston that allows the physician to ''manually'' inject the radiotracer without directly handling the syringe. RP FERRIERI, RA (reprint author), BROOKHAVEN NATL LAB,DEPT CHEM,UPTON,NY 11973, USA. FU NINDS NIH HHS [NS-15380] NR 14 TC 3 Z9 3 U1 0 U2 2 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD, ENGLAND OX5 1GB SN 0969-8043 J9 APPL RADIAT ISOTOPES JI Appl. Radiat. Isot. PD DEC PY 1994 VL 45 IS 12 BP 1149 EP 1154 DI 10.1016/0969-8043(94)90030-2 PG 6 WC Chemistry, Inorganic & Nuclear; Nuclear Science & Technology; Radiology, Nuclear Medicine & Medical Imaging SC Chemistry; Nuclear Science & Technology; Radiology, Nuclear Medicine & Medical Imaging GA QE683 UT WOS:A1994QE68300005 PM 7894394 ER PT J AU BARAN, DT AF BARAN, DT TI MEASUREMENT OF PU-GAMMA-RAY INTENSITIES BETWEEN 148-KEV AND 161-KEV SO APPLIED RADIATION AND ISOTOPES LA English DT Article AB Utilizing Pu isotopic standards characterized by the Institute for Nuclear Materials and Measurement (IRMM), New Brunswick Laboratory (NBL) measured the gamma-ray branching ratios of the 148.567-keV Pu-241, the 152.72-keV Pu-238, the 159.995-keV Pu-241 and the 160.28-keV Pu-240 gamma-rays. The study reported here includes the measurement of four IRMM standards, utilizing three different detectors for a total of 16 spectra, finding branching ratios of(1.863 +/- 0.008) x 10(-6), (9.230 +/- 0.068) x 10(-6), (6.321 +/- 0.040) x 10(-8) and (4.065 +/- 0.017)x 10-6, gamma/disintegration, respectively. RP BARAN, DT (reprint author), US DOE,NEW BRUNSWICK LAB,9800 S CASS AVE,BLD 350,ARGONNE,IL 60439, USA. NR 18 TC 3 Z9 3 U1 0 U2 0 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD, ENGLAND OX5 1GB SN 0969-8043 J9 APPL RADIAT ISOTOPES JI Appl. Radiat. Isot. PD DEC PY 1994 VL 45 IS 12 BP 1177 EP 1180 DI 10.1016/0969-8043(94)90033-7 PG 4 WC Chemistry, Inorganic & Nuclear; Nuclear Science & Technology; Radiology, Nuclear Medicine & Medical Imaging SC Chemistry; Nuclear Science & Technology; Radiology, Nuclear Medicine & Medical Imaging GA QE683 UT WOS:A1994QE68300008 ER PT J AU CREIGHTON, JR AF CREIGHTON, JR TI SURFACE STOICHIOMETRY AND THE ROLE OF ADSORBATES DURING GAAS ATOMIC LAYER EPITAXY SO APPLIED SURFACE SCIENCE LA English DT Article; Proceedings Paper CT 3rd International Symposium on Atomic Layer Epitaxy and Related Surface Processes (ALE-3) CY MAY 25-27, 1994 CL SENDAI, JAPAN SP JAPAN SOC APPL PHYS, JAPAN SOC PROMOT SCI, COMM NANO METER STRUCT & ELECTR ID REFLECTANCE-DIFFERENCE SPECTROSCOPY; III-V COMPOUNDS; BEAM EPITAXY; TRIMETHYLGALLIUM; GAAS(100); DECOMPOSITION; CHEMISTRY; EXPOSURE AB Several questions regarding the stoichiometry of atomic layer epitaxy (ALE) arise because most polar compound semiconductor surfaces reconstruct into structures terminated with less than monolayer coverage at the outermost layer. In this paper we briefly discuss how to self-consistently account for stoichiometry changes on surfaces that are not ideally terminated. The key aspect of the methodology is that surface steps are allowed to act as a reservoir where atoms may be added or removed. The methodology shows that ideal ALE of GaAs(100) cannot occur by cycling between the known adsorbate-free Ga-rich and As-rich surface reconstructions, because no such transition would yield the observed 1 monolayer (ML) per cycle growth rate. In fact, ideal ALE (1 ML/cycle) must involve at least one adsorbate induced surface reconstruction. Adsorbates may stabilize ideally terminated (i.e. vacancy free) III-V surfaces because of their ability to passivate dangling bond states. For example, methyl groups adsorbed on GaAs(100) exhibit a (1 x 2) LEED pattern, which is not seen for the clean GaAs(100) surface reconstructions. By using the electron counting model we interpret this structure as 1/2 ML CH3 adsorbed on a complete layer (1 ML) of dimerized Ga atoms. The GaAs(100)-(1 x 2)-CH3 surface was also examined using surface infrared spectroscopy (SIRS) using a multiple internal reflection geometry. This surface exhibits relatively sharp infrared linewidths suggestive of a well ordered structure. The polarization dependence of the symmetric stretching and bending CH3 modes also supports our proposed structure of the GaAs(100)-(1 x 2)-CH3 surface. The ideal termination of the Ga-rich GaAs(100)-(1 x 2)-CH3 surface allows for a plausible ALE mechanism which yields 1 ML deposition per cycle. RP CREIGHTON, JR (reprint author), SANDIA NATL LABS,DEPT 1126,MS 0601,POB 5800,ALBUQUERQUE,NM 87185, USA. NR 39 TC 16 Z9 16 U1 1 U2 2 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0169-4332 J9 APPL SURF SCI JI Appl. Surf. Sci. PD DEC PY 1994 VL 82-3 BP 171 EP 179 DI 10.1016/0169-4332(94)90214-3 PG 9 WC Chemistry, Physical; Materials Science, Coatings & Films; Physics, Applied; Physics, Condensed Matter SC Chemistry; Materials Science; Physics GA QA336 UT WOS:A1994QA33600030 ER PT J AU BOILEAU, MG TAYLOR, BE AF BOILEAU, MG TAYLOR, BE TI CHANCE EVENTS, HABITAT AGE, AND THE GENETIC-STRUCTURE OF POND POPULATIONS SO ARCHIV FUR HYDROBIOLOGIE LA English DT Article ID DAPHNIA-PULEX; NATURAL-POPULATIONS; F-STATISTICS; PATTERNS; DIFFERENTIATION; COPEPODS; CONSEQUENCES; ZOOPLANKTON; SELECTION; DIVERSITY AB We surveyed the genetic structure of zooplankton populations in small natural ponds to measure geographic patterns of differentiation and to evaluate the rates of genetic exchange. Populations of eight taxa (the calanoid copepods Aglaodiaptomus clavipoides, A. conipedatus, A. stagnalis, Aglaodiaptomus sp., Onychodiaptomus sanguineus, and Osphranticum labronectum, the cladoceran Daphnia laevis, and the conchostracan Lynceus gracilicornis) were sampled from 26 ponds in the uplands and alluvial terraces of the Savannah River Site near Aiken, South Carolina, USA. Genetic divergence THETA was high, with values of 0.053-0.297 for three calanoid copepods and one cladoceran. Dispersal, estimated from THETA by assuming equilibrium with genetic drift, yielded dispersal rates of 0.6-4.5 animals per generation. However, because the populations are large, founder effects in divergence should decay very slowly. Dispersal may thus be underestimated, but would still represent only miniscule proportions of the populations. For the two species sampled in both regions, insignificant differences in divergence between populations on the upland and populations on the alluvial terrace, which is younger, suggested persistent founder effects. Weak or insignificant correlations between genetic and geographic distances indicated that dispersal was poor over even very short distances or that local selection was strong. Comparisons of spatial patterns lead us to speculate that founder effects may persist longer in genetic composition than in taxonomic composition. C1 SAVANNAH RIVER ECOL LAB,AIKEN,SC 29802. RP BOILEAU, MG (reprint author), BROCK UNIV,DEPT BIOL SCI,ST CATHARINES,ON L2S 3A1,CANADA. NR 39 TC 26 Z9 26 U1 0 U2 3 PU E SCHWEIZERBART'SCHE VERLAGS PI STUTTGART PA NAEGELE U OBERMILLER JOHANNESSTRASSE 3A, D 70176 STUTTGART, GERMANY SN 0003-9136 J9 ARCH HYDROBIOL JI Arch. Hydrobiol. PD DEC PY 1994 VL 132 IS 2 BP 191 EP 202 PG 12 WC Limnology; Marine & Freshwater Biology SC Marine & Freshwater Biology GA QA259 UT WOS:A1994QA25900004 ER PT J AU BALL, DY AF BALL, DY TI ETHNIC-CONFLICT, UNIT PERFORMANCE, AND THE SOVIET ARMED-FORCES SO ARMED FORCES & SOCIETY LA English DT Article AB The Commonwealth of Independent States is struggling to create a central military command at the same time that individual members of the Commonwealth are forging their own national armies. Although the former task appears to be more daunting, the difficulties in creating stable, functional territorial armies should not be underestimated. Difficulties will arise because the states themselves are multinational in makeup and will have to contend with ethnic problems among their servicemen. Utilizing data from a survey of former Soviet citizens, the author tested two competing hypotheses about the impact of the Soviet military on ethnic relations in the now defunct Soviet empire in order to increase understanding of some of the difficulties that the newly independent states will confront as they establish their own militaries. The impact of ethnic tensions on military performance was also examined. The results provide no basis for claims that the Soviet military either exacerbated or mitigated ethnic conflict. However, ethnic relations had a profound impact on military performance. This article discusses the implications of these findings for the successor states to the Soviet Union. RP BALL, DY (reprint author), LAWRENCE LIVERMORE NATL LAB,LIVERMORE,CA 94550, USA. NR 37 TC 2 Z9 2 U1 0 U2 1 PU TRANSACTION PERIOD CONSORTIUM PI NEW BRUNSWICK PA DEPT 3091 RUTGERS-THE STATE UNIV OF NJ, NEW BRUNSWICK, NJ 08903 SN 0095-327X J9 ARMED FORCES SOC JI Armed Forces Soc. PD WIN PY 1994 VL 20 IS 2 BP 239 EP 258 DI 10.1177/0095327X9402000205 PG 20 WC Political Science; Sociology SC Government & Law; Sociology GA NA939 UT WOS:A1994NA93900004 ER PT J AU EDWARDS, KL AUSTIN, MA NEWMAN, B MAYER, E KRAUSS, RM SELBY, JV AF EDWARDS, KL AUSTIN, MA NEWMAN, B MAYER, E KRAUSS, RM SELBY, JV TI MULTIVARIATE-ANALYSIS OF THE INSULIN-RESISTANCE SYNDROME IN WOMEN SO ARTERIOSCLEROSIS AND THROMBOSIS LA English DT Article DE INSULIN RESISTANCE SYNDROME; MULTIVARIATE ANALYSIS; LIPOPROTEINS; OBESITY; WOMEN ID CORONARY HEART-DISEASE; BODY-FAT DISTRIBUTION; RISK-FACTORS; ESSENTIAL-HYPERTENSION; GLUCOSE-INTOLERANCE; PLASMA TRIGLYCERIDE; HYPERINSULINEMIA; OBESITY; MORTALITY; PREVALENCE AB The insulin resistance syndrome (IRS) is characterized by a constellation of interrelated coronary heart disease (CHD) risk factors, including dyslipidemia, obesity, central obesity, elevated systolic blood pressure, and hyperinsulinemia. Factor analysis was used to investigate the clustering of these risk factors in individuals by examining the correlational structure among these variables. Data from 281 genetically unrelated nondiabetic women who participated in exam 2 (1979 to 1980) of the Kaiser Permanente Women Twins Study were used. Factor analysis reduced 10 correlated risk factors to 3 uncorrelated factors, each reflecting a different aspect of the IRS: factor 1 (increased body weight, waist circumference, fasting insulin, and glucose), factor 2 (increased postload and fasting glucose and insulin and systolic blood pressure), and factor 3 (larger low-density lipoprotein particles, decreased plasma triglycerides, and increased high-density lipoprotein). Together, the factors explained nearly 66% of the total variance in the data. Thus, factor analysis defined three distinct aspects of the IRS in this sample of nondiabetic women. These factors may reflect separate underlying mechanisms of the syndrome, each of which may also be involved in CHD risk. C1 UNIV N CAROLINA,SCH PUBL HLTH,DEPT EPIDEMIOL,CHAPEL HILL,NC. WAKE FOREST UNIV,BOWMAN GRAY SCH MED,DEPT PUBL HLTH SCI,WINSTON SALEM,NC 27103. UNIV CALIF BERKELEY,LAWRENCE BERKELEY LAB,DIV LIFE SCI,BERKELEY,CA 94720. KAISER PERMANENTE MED CARE PROGRAM,DIV RES,OAKLAND,CA 94611. RP EDWARDS, KL (reprint author), UNIV WASHINGTON,SCH PUBL HLTH,DEPT EPIDEMIOL,SC-36,SEATTLE,WA 98195, USA. FU NHLBI NIH HHS [HL-18574, R01 HL-4830] NR 56 TC 144 Z9 150 U1 0 U2 2 PU AMER HEART ASSOC PI DALLAS PA 7272 GREENVILLE AVENUE, DALLAS, TX 75231-4596 SN 1049-8834 J9 ARTERIOSCLER THROMB JI Arterioscler. Thromb. PD DEC PY 1994 VL 14 IS 12 BP 1940 EP 1945 PG 6 WC Cardiac & Cardiovascular Systems; Peripheral Vascular Disease SC Cardiovascular System & Cardiology GA PX015 UT WOS:A1994PX01500009 PM 7981183 ER PT J AU GREGG, MD AF GREGG, MD TI SPECTROPHOTOMETRY OF EARLY-TYPE SYSTEMS .1. A METALLICITY SEQUENCE OF GLOBULAR-CLUSTERS SO ASTRONOMICAL JOURNAL LA English DT Article ID DIFFERENTIAL POPULATION SYNTHESIS; STELLAR POPULATIONS; ELLIPTICAL GALAXIES; INTEGRATED SPECTRA; STAR-CLUSTERS; 47-TUCANAE; SPECTROSCOPY; ABUNDANCES; EVOLUTION; GIANTS RP GREGG, MD (reprint author), LAWRENCE LIVERMORE NATL LAB,INST GEOPHYS & PLANETARY PHYS,7000 E AVE,LIVERMORE,CA 94550, USA. NR 50 TC 17 Z9 17 U1 0 U2 0 PU AMER INST PHYSICS PI WOODBURY PA CIRCULATION FULFILLMENT DIV, 500 SUNNYSIDE BLVD, WOODBURY, NY 11797-2999 SN 0004-6256 J9 ASTRON J JI Astron. J. PD DEC PY 1994 VL 108 IS 6 BP 2164 EP 2182 DI 10.1086/117228 PG 19 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA PU983 UT WOS:A1994PU98300018 ER PT J AU REVELLE, DO CEPLECHA, Z AF REVELLE, DO CEPLECHA, Z TI ANALYSIS OF IDENTIFIED IRON METEOROIDS - POSSIBLE RELATION WITH M-TYPE EARTH-CROSSING ASTEROIDS SO ASTRONOMY & ASTROPHYSICS LA English DT Article DE METEROIDS; ASTEROIDS ID METEORITES; ABLATION; ENTRY AB We have used two different techniques to analyze the U. S. Prairie Network (PN) fireballs in order to search for possible nickel-iron meteoroids. The first approach used is that of ReVelle and Rajan which is similar to the analysis carried out earlier by Wetherill and ReVelle in a series of papers relating first to the chondrites and later to fireballs of cometary origin. The second approach is a new technique developed by Ceplecha and co-workers that can simultaneously determine the presence and location of gross fragmentation events and also determine an effective ablation parameter during the fireball entry. Using this combined approach we have determined that seven fireballs among the 287 that were analyzed are likely to be iron in composition. Using the method of Ceplecha we have determined that none of these objects experienced any gross fragmentation events during their entry to the atmosphere and most of the meteoroids also exhibited rather large ablation coefficients during entry as well, a feature that is also characteristic of the ReVelle and Rajan approach. Six of these objects have orbits with their aphelia in the main part of the asteroid belt similar to those of the three photographed and recovered meteorites. One of these iron meteoroids has an orbit of the Aten type as does one of the detected Earth-crossing asteroids, 3554 Amun. Two additional meteoroids of the Aten type also passed two of the three possible tests of ReVelle and Rajan. For all of these objects for which we currently have available data, we have determined that gross fragmentation events did not occur during the entry. Further studies are needed to locate more of these objects so that the association between M-Type Earth-crossing asteroids and iron meteoroids observed in the atmosphere can be strengthened. C1 ACAD SCI CZECH REPUBL, INST ASTRON, CR-25165 ONDREJOV OBSERV, CZECH REPUBLIC. LOS ALAMOS NATL LAB, LOS ALAMOS, NM USA. NR 33 TC 14 Z9 14 U1 0 U2 0 PU EDP SCIENCES S A PI LES ULIS CEDEX A PA 17, AVE DU HOGGAR, PA COURTABOEUF, BP 112, F-91944 LES ULIS CEDEX A, FRANCE SN 0004-6361 J9 ASTRON ASTROPHYS JI Astron. Astrophys. PD DEC PY 1994 VL 292 IS 1 BP 330 EP 336 PG 7 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA PV400 UT WOS:A1994PV40000035 ER PT J AU AUER, L BENDICHO, PF BUENO, JT AF AUER, L BENDICHO, PF BUENO, JT TI MULTIDIMENSIONAL RADIATIVE-TRANSFER WITH MULTILEVEL ATOMS .1. ALI METHOD WITH PRECONDITIONING OF THE RATE-EQUATIONS SO ASTRONOMY & ASTROPHYSICS LA English DT Article DE RADIATIVE TRANSFER; LINE, FORMATION; METHODS, NUMERICAL; SUN, CHROMOSPHERE; STARS, ATMOSPHERES ID APPROXIMATE LAMBDA-OPERATORS; STRATIFIED ATMOSPHERES; SOLAR CHROMOSPHERE; ITERATION METHOD; LINE; CONTINUUM; MODELS AB We combine a number of powerful mathematical techniques to produce an effective method for treating multidimensional radiative transfer problems in complex atomic models without assuming LTE. The approach is so efficient that multilevel two-dimensional (2D) modeling can now be performed with no more than a workstation. We employ Accelerated Lambda Iteration (ALI) methods: accurate short characteristics for the formal solution of the transfer equation with an efficient new strategy for horizontal periodic boundary conditions, local approximate h-operators given by the diagonal of the exact operator, methods to accelerate the convergence, and preconditioning of the rate equations. Of particular interest is a simple grid-doubling strategy which both rapidly finds the converged solution in very fine meshes and also estimates the true error of that solution. The properties of the method are described in detail with the help of 2D line-transfer calculations with multilevel model atoms for Ca II and H. These illustrative multilevel calculations in schematic inhomogeneous atmospheres demonstrate the importance of properly including the effects of horizontal radiative transfer and realistic atomic models. C1 INST ASTROFIS CANARIAS, E-38200 LA LAGUNA, SPAIN. LOS ALAMOS NATL LAB, LOS ALAMOS, NM 87545 USA. UNIV FLORENCE, DEPT ASTRON & SPACE SCI, I-50125 FLORENCE, ITALY. RI Fabiani Bendiccho, Maria de la Pena/C-5684-2017 NR 50 TC 81 Z9 81 U1 1 U2 1 PU EDP SCIENCES S A PI LES ULIS CEDEX A PA 17, AVE DU HOGGAR, PA COURTABOEUF, BP 112, F-91944 LES ULIS CEDEX A, FRANCE SN 1432-0746 J9 ASTRON ASTROPHYS JI Astron. Astrophys. PD DEC PY 1994 VL 292 IS 2 BP 599 EP 615 PG 17 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA PW489 UT WOS:A1994PW48900028 ER PT J AU BENNETT, CL KOGUT, A HINSHAW, G BANDAY, AJ WRIGHT, EL GORSKI, KM WILKINSON, DT WEISS, R SMOOT, GF MEYER, SS MATHER, JC LUBIN, P LOEWENSTEIN, K LINEWEAVER, C KEEGSTRA, P KAITA, E JACKSON, PD CHENG, ES AF BENNETT, CL KOGUT, A HINSHAW, G BANDAY, AJ WRIGHT, EL GORSKI, KM WILKINSON, DT WEISS, R SMOOT, GF MEYER, SS MATHER, JC LUBIN, P LOEWENSTEIN, K LINEWEAVER, C KEEGSTRA, P KAITA, E JACKSON, PD CHENG, ES TI COSMIC TEMPERATURE-FLUCTUATIONS FROM 2 YEARS OF COBE DIFFERENTIAL MICROWAVE RADIOMETERS OBSERVATIONS SO ASTROPHYSICAL JOURNAL LA English DT Article DE COSMIC MICROWAVE BACKGROUND; COSMOLOGY, OBSERVATIONS; LARGE-SCALE STRUCTURE OF UNIVERSE ID COLD DARK-MATTER; LARGE-SCALE STRUCTURE; ANGULAR-CORRELATION FUNCTION; COSMOLOGICAL SCENARIO; EXTRAGALACTIC OBJECTS; STATISTICAL-ANALYSIS; UNIVERSE; ANISOTROPY; MAPS; HOT AB The first two years of COBE Differential Microwave Radiometers (DMR) observations of the cosmic microwave background (CMB) anisotropy are analyzed and compared with our previously published first year results. The results are consistent, but the addition of the second year of data increases the precision and accuracy of the detected CMB temperature fluctuations. The 2 yr 53 GHz data are characterized by rms temperature fluctuations of (Delta T)(rms)(7 degrees) = 44 +/- 7 mu K and (Delta T)(rms)(10 degrees) = 30.5 +/- 2.7 mu K at 7 degrees and 10 degrees angular resolution, respectively. The 53 x 90 GHz cross-correlation amplitude at zero lag is C(0)(1/2) = 36 +/- 5 mu K (68% CL) for the unsmoothed (7 degrees resolution) DMR data. We perform a likelihood analysis of the cross-correlation function, with Monte Carlo simulations to infer biases of the method, for a power-law model of initial density fluctuations, P(k) proportional to k(n). The Monte Carlo simulations indicate that derived estimates of n are biased by +0.11 +/- 0.0l, while the subset of simulations with a low quadrupole (as observed) indicate a bias of +0.31 +/- 0.04. Derived values for 68% confidence intervals are given corrected (and not corrected) for our estimated biases. Including the quadrupole anisotropy, the most likely quadrupole-normalized amplitude is Q(rms-PS) = 14.3(-3.3)(+5.2) mu K (12.8(-3.3)(+5.2) mu K) with a spectral index n = 1.42(0.55)(+0.49) (n = 1.53(-0.55)(+0.49)). With n fixed to 1.0 the most likely amplitude is 18.2 +/- 1.5 mu K (17.4 +/- 1.5 mu K). The marginal likelihood of n is 1.42 +/- 0.37 (1.53 +/- 0.37). Excluding the quadrupole anisotropy, the most likely quadrupole-normalized amplitude is Q(rms-PS) = 17.4(-5.2)(+7.5) mu K (15.8(-5.2)(+7.5) mu K) with a spectral index n = 1.11(-0.55)(+0.60) (n = 1.22(-0.55)(+0.60)) With n fixed to 1.0 the most likely amplitude is 18.6 +/- 1.6 mu K (18.2 +/- 1.6 mu K). The marginal likelihood of n is 1.11 +/- 0.40 (1.22 +/- 0.40). Our best estimate of the dipole from the 2 yr DMR data is 3.363 +/- 0.024 mK toward Galactic coordinates (l, b) = (264 degrees.4 +/- 0 degrees.2, +48 degrees.1 +/- 0 degrees.4), and our best estimate of the rms quadrupole amplitude in our sky is 6 +/- 3 mu K (68% CL). C1 NASA, GODDARD SPACE FLIGHT CTR, UNIV SPACE RES ASSOC, GREENBELT, MD 20771 USA. UNIV CALIF LOS ANGELES, DEPT ASTRON, LOS ANGELES, CA 90024 USA. PRINCETON UNIV, DEPT PHYS, PRINCETON, NJ 08540 USA. MIT, DEPT PHYS, CAMBRIDGE, MA 02139 USA. UNIV CALIF BERKELEY, LAWRENCE BERKELEY LAB, BERKELEY, CA 94720 USA. UNIV CHICAGO, ENRICO FERMI INST, DEPT ASTRON & ASTROPHYS, CHICAGO, IL 60637 USA. UNIV CALIF SANTA BARBARA, DEPT PHYS, SANTA BARBARA, CA 93106 USA. RP BENNETT, CL (reprint author), NASA, GODDARD SPACE FLIGHT CTR, CODE 685, GREENBELT, MD 20771 USA. RI Kogut, Alan/D-6293-2012 NR 77 TC 244 Z9 246 U1 0 U2 7 PU IOP PUBLISHING LTD PI BRISTOL PA TEMPLE CIRCUS, TEMPLE WAY, BRISTOL BS1 6BE, ENGLAND SN 0004-637X J9 ASTROPHYS J JI Astrophys. J. PD DEC 1 PY 1994 VL 436 IS 2 BP 423 EP 442 DI 10.1086/174918 PN 1 PG 20 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA PV552 UT WOS:A1994PV55200001 ER PT J AU WRIGHT, EL SMOOT, GF BENNETT, CL LUBIN, PM AF WRIGHT, EL SMOOT, GF BENNETT, CL LUBIN, PM TI ANGULAR POWER SPECTRUM OF THE MICROWAVE BACKGROUND ANISOTROPY SEEN BY THE COBE DIFFERENTIAL MICROWAVE RADIOMETER SO ASTROPHYSICAL JOURNAL LA English DT Article DE COSMIC MICROWAVE BACKGROUND; COSMOLOGY, OBSERVATIONS; LARGE-SCALE STRUCTURE OF UNIVERSE ID INFLATIONARY UNIVERSE; EXTRAGALACTIC OBJECTS; STATISTICAL-ANALYSIS; SCALE ANISOTROPY; RADIATION; FLUCTUATIONS; CATALOGS; SEARCH; MAPS AB The angular power spectrum estimator developed by Peebles (1973) and Hauser and Peebles (1973) has been modified and applied to the 2 yr maps produced by the COBE DMR. The power spectrum of the real sky has been compared to the power spectra of a large number of simulated random skies produced with noise equal to the observed noise and primordial density fluctuation power spectra of power-law form, with P(k) proportional to k(n). Within the limited range of spatial scales covered by the COBE DMR, corresponding to spherical harmonic indices 3 less than or equal to l less than or similar to 30, the best-fitting value of the spectral index is n = 1.25(-0.45)(+0.4) with the Harrison-Zel'dovich value n = 1 approximately 0.5 sigma below the best fit. For 3 less than or equal to l less than or similar to 19, the best fit is n = 1.46(-0.44)(+0.39). Comparing the COBE DMR Delta T/T at small l to the Delta T/T at 1 approximate to 50 from degree scale anisotropy experiments gives a smaller range of acceptable spectral indices which includes n = 1. C1 UNIV CALIF BERKELEY,LAWRENCE BERKELEY LAB,BERKELEY,CA 94720. UNIV CALIF BERKELEY,SPACE SCI LAB,BERKELEY,CA 94720. NASA,GODDARD SPACE FLIGHT CTR,GREENBELT,MD 20771. UNIV CALIF SANTA BARBARA,DEPT PHYS,SANTA BARBARA,CA 93106. RP WRIGHT, EL (reprint author), UNIV CALIF LOS ANGELES,DEPT ASTRON,LOS ANGELES,CA 90024, USA. NR 44 TC 66 Z9 66 U1 0 U2 1 PU UNIV CHICAGO PRESS PI CHICAGO PA 5720 S WOODLAWN AVE, CHICAGO, IL 60637 SN 0004-637X J9 ASTROPHYS J JI Astrophys. J. PD DEC 1 PY 1994 VL 436 IS 2 BP 443 EP 451 DI 10.1086/174919 PN 1 PG 9 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA PV552 UT WOS:A1994PV55200002 ER PT J AU LINEWEAVER, CH SMOOT, GF BENNETT, CL WRIGHT, EL TENORIO, L KOGUT, A KEEGSTRA, PB HINSHAW, G BANDAY, AJ AF LINEWEAVER, CH SMOOT, GF BENNETT, CL WRIGHT, EL TENORIO, L KOGUT, A KEEGSTRA, PB HINSHAW, G BANDAY, AJ TI CORRELATED NOISE IN THE COBE DMR SKY MAPS SO ASTROPHYSICAL JOURNAL LA English DT Article DE COSMIC MICROWAVE BACKGROUND; COSMOLOGY, OBSERVATIONS; METHODS, STATISTICAL ID DIFFERENTIAL MICROWAVE RADIOMETERS AB The COBE DMR sky maps contain low-level correlated noise. We obtain estimates of the amplitude and pattern of the correlated noise from three techniques: angular averages of the covariance matrix, Monte Carlo simulations of two-point correlation functions, and direct analysis of the DMR maps. The results from the three methods are mutually consistent. The noise covariance matrix of a DMR sky map is diagonal to an accuracy of better than 1%. For a given sky pixel, the dominant noise covariance occurs with the ring of pixels at an angular separation of 60 degrees due to the 60 degrees separation of the DMR horns. The mean covariance at 60 degrees is 0.45%(+0.18)(-0.14) of the mean variance. Additionally, the variance in a given pixel is 0.7% greater than would be expected from a single beam experiment with the same noise properties. Autocorrelation functions suffer from a similar to 1.5 sigma positive bias at 60 degrees while cross-correlations have no bias. Published COBE DMR results are not significantly affected by correlated noise. C1 NASA, GODDARD SPACE FLIGHT CTR, GREENBELT, MD 20771 USA. UNIV CALIF LOS ANGELES, DEPT ASTRON, LOS ANGELES, CA 90024 USA. NASA, GODDARD SPACE FLIGHT CTR, HUGHES STX CORP, GREENBELT, MD 20771 USA. NASA, GODDARD SPACE FLIGHT CTR, UNIV SPACE RES ASSOC, GREENBELT, MD 20771 USA. RP LINEWEAVER, CH (reprint author), UNIV CALIF BERKELEY, CTR PARTICLE ASTROPHYS, LAWRENCE BERKELEY LAB, SPACE SCI LAB, BLDG 50-205, BERKELEY, CA 94720 USA. RI Kogut, Alan/D-6293-2012 NR 15 TC 41 Z9 41 U1 0 U2 0 PU IOP PUBLISHING LTD PI BRISTOL PA TEMPLE CIRCUS, TEMPLE WAY, BRISTOL BS1 6BE, ENGLAND SN 0004-637X J9 ASTROPHYS J JI Astrophys. J. PD DEC 1 PY 1994 VL 436 IS 2 BP 452 EP 455 DI 10.1086/174920 PN 1 PG 4 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA PV552 UT WOS:A1994PV55200003 ER PT J AU AUER, LH KOENIGSBERGER, G AF AUER, LH KOENIGSBERGER, G TI LINE-PROFILE VARIATIONS FROM ATMOSPHERIC ECLIPSES - CONSTRAINTS ON THE WIND STRUCTURE IN WOLF-RAYET STARS SO ASTROPHYSICAL JOURNAL LA English DT Article DE BINARIES, ECLIPSING; LINE, PROFILES; STARS, INDIVIDUAL (V444 CYGNI); STARS, MASS LOSS; STARS, WOLF-RAYET ID RADIATION-DRIVEN WINDS; HOT LUMINOUS STARS; HE-II SPECTRA; BINARY V444-CYGNI; HD-50896; SYSTEMS AB Binary systems in which one of the components has a stellar wind may present a phenomenon known as ''wind'' or ''atmospheric eclipse,'' in which that wind occults the luminous disk of the companion. The enhanced absorption profile, relative to the spectrum at uneclipsed orbital phases, can be modeled to yield constraints on the spatial structure of the eclipsing wind. A new, very efficient approach to the radiative transfer problem, which makes no requirements with respect to monotonicity of the velocity gradient or the size of that gradient, is presented. The technique recovers both the comoving frame calculation and the Sobolev approximation in the appropriate limits. Sample computer simulations of the line profile variations induced by wind eclipses are presented. It is shown that the location of the wind absorption features in frequency is a diagnostic tool for identifying the size of the wind acceleration region. Comparison of the model profile variations with the observed variations in the W-R+6 binary system V444 Cyg illustrate how the method can be used to derive information on the structure of the wind of the W-R star and constrain the size of the W-R core radius. C1 Univ Nacl Autonoma Mexico, INST ASTRON, MEXICO CITY 04510, DF, MEXICO. RP AUER, LH (reprint author), LOS ALAMOS NATL LAB, ESS-5, MS F665, LOS ALAMOS, NM 87545 USA. NR 39 TC 25 Z9 25 U1 0 U2 0 PU IOP PUBLISHING LTD PI BRISTOL PA DIRAC HOUSE, TEMPLE BACK, BRISTOL BS1 6BE, ENGLAND SN 0004-637X J9 ASTROPHYS J JI Astrophys. J. PD DEC 1 PY 1994 VL 436 IS 2 BP 859 EP 870 DI 10.1086/174963 PN 1 PG 12 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA PV552 UT WOS:A1994PV55200046 ER PT J AU BANDAY, AJ GORSKI, KM TENORIO, L WRIGHT, EL SMOOT, GF LINEWEAVER, CH KOGUT, A HINSHAW, G BENNETT, CL AF BANDAY, AJ GORSKI, KM TENORIO, L WRIGHT, EL SMOOT, GF LINEWEAVER, CH KOGUT, A HINSHAW, G BENNETT, CL TI ON THE RMS ANISOTROPY AT 7-DEGREES AND 10-DEGREES OBSERVED IN THE COBE(1)-DMR 2-YEAR SKY MAPS SO ASTROPHYSICAL JOURNAL LA English DT Article DE COSMIC MICROWAVE BACKGROUND; COSMOLOGY, OBSERVATIONS AB The frequency-independent rms temperature fluctuations determined from the COBE-DMR two-year sky maps are used to infer the parameter Q(rms-PS), which characterizes the normalization of power-law models of primordial cosmological temperature anisotropy, for a forced fit to a scale-invariant Harrison-Zel'dovich (n = 1) spectral model. Using a joint analysis of the 7 degrees and 10 degrees ''cross''-rms derived from both the 53 and 90 GHz sky maps, we find Q(rms-PS) = 17.0-(+2.5)(2.1) mu K when the low quadrupole is included, and Q(rms-PS) = 19.4(+2.1)(+2.3) mu K excluding the quadrupole. These results are consistent with the n = 1 fits from more sensitive methods. The effect of the low quadrupole derived from the COBE-DMR data on the inferred Q(rms-PS) normalization is investigated. A bias to lower Q(rms-PS) is found when the quadrupole is included. The higher normalization for a forced n = 1 fit is then favored by the cross-rms technique. C1 UNIV CALIF BERKELEY,LAWRENCE BERKELEY LAB,SSL,BERKELEY,CA 94720. UNIV CALIF BERKELEY,CFPA,BERKELEY,CA 94720. UNIV CALIF LOS ANGELES,DEPT ASTRON,LOS ANGELES,CA 90024. HUGHES STX CORP,LANHAM,MD 20706. RP BANDAY, AJ (reprint author), NASA,GODDARD SPACE FLIGHT CTR,UNIV SPACE RES ASSOC,CODE 6853,GREENBELT,MD 20771, USA. RI Kogut, Alan/D-6293-2012 NR 11 TC 25 Z9 25 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 DEC 1 PY 1994 VL 436 IS 2 BP L99 EP L102 DI 10.1086/187642 PN 2 PG 4 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA PV554 UT WOS:A1994PV55400001 ER PT J AU DAISEY, JM HODGSON, AT FISK, WJ MENDELL, MJ TENBRINKE, J AF DAISEY, JM HODGSON, AT FISK, WJ MENDELL, MJ TENBRINKE, J TI VOLATILE ORGANIC-COMPOUNDS IN 12 CALIFORNIA OFFICE BUILDINGS - CLASSES, CONCENTRATIONS AND SOURCES SO ATMOSPHERIC ENVIRONMENT LA English DT Article; Proceedings Paper CT Indoor Air 93 Congress CY JUL, 1993 CL HELSINKI, FINLAND DE VOLATILE ORGANIC COMPOUNDS (VOC); TOTAL VOLATILE ORGANIC COMPOUNDS (TVOC); OFFICE BUILDINGS; INDOOR SOURCES; OUTDOOR AIR AB Concentrations of total volatile organic compounds (TVOC) and of 39 individual volatile organic compounds (VOCs) were measured in 12 northern California office buildings of three different ventilation types. The objectives were to characterize indoor air exposures to VOCs, to investigate variations in chemical composition and concentrations among the buildings, and to identify potential sources of the VOCs. Indoor TVOC concentrations ranged from 230 to 7000 mu g m(-3) with a geometric mean of 510 mu g m(-3). The highest TVOC concentrations were measured in two buildings with wet-process photocopiers. Geometric mean concentrations of individual VOCs were, with one exception, less than 5 ppb. There was considerable variation in the chemical composition of the VOC mixtures among the buildings. For most buildings, the oxidized hydrocarbons were the dominant class. Factor analysis identified motor vehicle emissions from outdoor air as a major source of seven aromatic and five alkane hydrocarbons. There was evidence of freon leaking from air conditioning or refrigeration systems in several of the buildings. RP DAISEY, JM (reprint author), UNIV CALIF BERKELEY,LAWRENCE BERKELEY LAB,DIV ENERGY & ENVIRONM,INDOOR ENVIRONM PROGRAM,BERKELEY,CA 94720, USA. NR 11 TC 77 Z9 82 U1 5 U2 17 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD, ENGLAND OX5 1GB SN 1352-2310 J9 ATMOS ENVIRON JI Atmos. Environ. PD DEC PY 1994 VL 28 IS 22 BP 3557 EP 3562 DI 10.1016/1352-2310(94)00200-5 PG 6 WC Environmental Sciences; Meteorology & Atmospheric Sciences SC Environmental Sciences & Ecology; Meteorology & Atmospheric Sciences GA QB503 UT WOS:A1994QB50300002 ER PT J AU ANDREWS, JC NOLAN, JP HAMMERSTEDT, RH BAVISTER, BD AF ANDREWS, JC NOLAN, JP HAMMERSTEDT, RH BAVISTER, BD TI ROLE OF ZINC DURING HAMSTER SPERM CAPACITATION SO BIOLOGY OF REPRODUCTION LA English DT Article ID SALT-STORED HAMSTER; MOUSE OVA INVITRO; HUMAN-SPERMATOZOA; ACROSOME REACTION; ZONA-PELLUCIDA; GOLDEN-HAMSTER; FERTILIZATION; PROTEIN; MAGNESIUM; EGGS AB Zinc stabilizes somatic cell membranes and DNA, inhibits respiration, is present in high concentrations in the male reproductive tract, and may stabilize sperm during storage and ejaculation. Zinc removal from sperm may be necessary to prepare sperm for fertilization (capacitation). Incubation with Zn2+ chelators, e.g., D-penicillamine, can capacitate hamster sperm (Andrews and Bavister, Gamete Res 1989; 23:153-70). In the present study, the Zn2+-specific fluorochrome N-(6-methoxy-8-quinolyl)-p-toluenesulfonamide (TSQ) and the vital stain propidium iodide were used to assess the zinc content of live hamster sperm with how cytometry before and after capacitation. Capacitation was monitored with a salt-stored zona pellucida penetration assay or the occurrence of spontaneous or induced (with lysophosphatidylcholine) acrosome reactions. The effect of added zinc on sperm capacitation was also evaluated. Image Analysis was used to determine the subcellular location of zinc (TSQ fluorescence) and atomic absorption to determine whether the total zinc content of sperm changes during capacitation. Sperm incubated under non-capacitating conditions had high TSQ fluorescence and could not penetrate zonae pellucidae. Sperm incubated under capacitating conditions (plus BSA or D-penicillamine) were zinc-depleted (low fluorescence) and penetrated 90% or 78% of zonae, respectively. Image analysis showed a significant reduction in zinc in the acrosomal region during capacitation with BSA, but this did not correlate with the occurrence of spontaneous acrosome reactions. The atomic absorption data showed that the total zinc content of sperm was reduced by 44% or 40% when sperm were incubated under capacitating conditions (BSA or D-penicillamine, respectively). Zona pellucida penetration was completely inhibited when zinc was present throughout the capacitation period but not when it was added at the end of incubation. These data indicate that removal of zinc from hamster sperm is correlated with capacitation and may play a key regulatory role in this process. C1 LOS ALAMOS NATL LAB,DIV LIFE SCI LS-1,LOS ALAMOS,NM 87545. UNIV WISCONSIN,DEPT ANIM HLTH & BIOMED SCI,MADISON,WI 53706. RP ANDREWS, JC (reprint author), PENN STATE UNIV,DEPT BIOCHEM & MOLEC BIOL,BIOCHEM PROGRAM,406 ALTHOUSE LAB,UNIVERSITY PK,PA 16802, USA. FU NICHD NIH HHS [HD14235, HD13099] NR 51 TC 44 Z9 48 U1 0 U2 1 PU SOC STUDY REPRODUCTION PI MADISON PA 1603 MONROE ST, MADISON, WI 53711-2021 SN 0006-3363 J9 BIOL REPROD JI Biol. Reprod. PD DEC PY 1994 VL 51 IS 6 BP 1238 EP 1247 DI 10.1095/biolreprod51.6.1238 PG 10 WC Reproductive Biology SC Reproductive Biology GA PR430 UT WOS:A1994PR43000021 PM 7888501 ER PT J AU BRADLEY, KF CHEN, SH BELLISSENTFUNEL, MC CRESPI, HL AF BRADLEY, KF CHEN, SH BELLISSENTFUNEL, MC CRESPI, HL TI THE OBSERVATION OF STRUCTURAL TRANSITIONS OF A SINGLE PROTEIN MOLECULE SO BIOPHYSICAL CHEMISTRY LA English DT Article DE C-PHYCOCYANIN PROTEIN; NEUTRON SCATTERING; STRUCTURE FACTOR; TRANSITION ID CYANOBACTERIUM MASTIGOCLADUS-LAMINOSUS; AMINO-ACID-SEQUENCE; C-PHYCOCYANIN; SUBUNITS AB Coherent neutron scattering measurements of an amorphous, in vivo deuterated C-phycocyanin are compared with a calculation of the individual protein molecule's coherent static structure factor. Both show the significant features associated with known structure factors of several amorphous materials, most notably, an unusually sharp first diffraction peak occurring near 1.4 Angstrom(-1). We show that in the protein, such a peak results from the product of a form factor associated with correlations of atoms within individual amino acids and a structural term expressing inter-amino-acid correlations. The measurement, interpreted through behavior of the first diffraction peak, indicates that inter-amino-acid correlations - a measure of the protein's medium-range structure - undergo transitions which are primarily related to hydration rather than to temperature. C1 CENS,CEA,LAB LEON BRILLOUIN,CNRS,F-91191 GIF SUR YVETTE,FRANCE. ARGONNE NATL LAB,ARGONNE,IL 60439. RP BRADLEY, KF (reprint author), MIT,24-211,CAMBRIDGE,MA 02139, USA. NR 10 TC 3 Z9 3 U1 0 U2 2 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0301-4622 J9 BIOPHYS CHEM JI Biophys. Chem. PD DEC PY 1994 VL 53 IS 1-2 BP 37 EP 43 DI 10.1016/0301-4622(94)00074-3 PG 7 WC Biochemistry & Molecular Biology; Biophysics; Chemistry, Physical SC Biochemistry & Molecular Biology; Biophysics; Chemistry GA QA837 UT WOS:A1994QA83700005 PM 17020838 ER PT J AU HENDERSON, SJ SERPERSU, EH GERHARDT, BS BUNICK, GJ AF HENDERSON, SJ SERPERSU, EH GERHARDT, BS BUNICK, GJ TI CONFORMATIONAL-CHANGES IN YEAST PHOSPHOGLYCERATE KINASE UPON SUBSTRATE-BINDING SO BIOPHYSICAL CHEMISTRY LA English DT Article DE YEAST PHOSPHOGLYCERATE KINASE; SMALL-ANGLE NEUTRON SCATTERING; 2ND VIRIAL COEFFICIENT; CONFORMATIONAL CHANGE; RADIUS OF GYRATION ID SITE-DIRECTED MUTAGENESIS; CHROMIUM(III) ADENOSINE 5'-TRIPHOSPHATE; 3-PHOSPHOGLYCERATE KINASE; ACTIVE-SITE; SULFATE ION; INTERDOMAIN REGION; CATALYTIC ACTIVITY; ANION BINDING; HINGE REGION; NMR ANALYSIS AB Small-angle neutron scattering (SANS) was used to measure the radius of gyration (R(g)) of solutions of phosphoglycerate kinase (PGK) in a variety of substrate environments in D2O. The R(g) of 24.0 Angstrom was measured for native PGK. A decrease in R(g) was observed for the following: 23.7 Angstrom for PGK + sulphate; 23.5 Angstrom for PGK + beta,gamma-bidentate Cr(H2O)(4)ATP (CrATP); 23.3 Angstrom for PGK+ 3-phospho-D-glycerate (PGA) + CrATP; 22.9 Angstrom for PGK+ CrATP+ sulphate; 22.6 Angstrom for PGK + PGA + CrATP + sulphate. The statistical error was about +/- 0.3 Angstrom, which is less than systematic effects in this system. These results are consistent with catalysis by a hinge-bending motion of the enzyme. Since CrATP is not hydrolyzed, these results represent the conformational states of the bound substrates in the catalytically relevant ternary complex in the absence of product formation. The second virial coefficient is also measured for this system and this is consistent with that calculated from the protein volume only. C1 UNIV TENNESSEE,DEPT BIOCHEM,KNOXVILLE,TN 37996. RP HENDERSON, SJ (reprint author), OAK RIDGE NATL LAB,DIV BIOL,POB 2009,OAK RIDGE,TN 37831, USA. FU NIGMS NIH HHS [GM29818, GM42661] NR 42 TC 13 Z9 13 U1 1 U2 3 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0301-4622 J9 BIOPHYS CHEM JI Biophys. Chem. PD DEC PY 1994 VL 53 IS 1-2 BP 95 EP 104 DI 10.1016/0301-4622(94)00080-8 PG 10 WC Biochemistry & Molecular Biology; Biophysics; Chemistry, Physical SC Biochemistry & Molecular Biology; Biophysics; Chemistry GA QA837 UT WOS:A1994QA83700011 PM 7841334 ER PT J AU WARD, MD DEMBO, M HAMMER, DA AF WARD, MD DEMBO, M HAMMER, DA TI KINETICS OF CELL DETACHMENT - PEELING OF DISCRETE RECEPTOR CLUSTERS SO BIOPHYSICAL JOURNAL LA English DT Article ID MEMBRANE-MEMBRANE ADHESION; MOLECULAR CROSS-BRIDGES; EXTRACELLULAR-MATRIX; DETAILED MECHANICS; CYTOPLASMIC DOMAIN; FOCAL CONTACTS; FIBRONECTIN; GROWTH; DIFFERENTIATION; FIBROBLASTS AB Clustering of cell surface adhesion receptors is an essential step in the development of focal contacts, specialized cell-substrate attachment sites where receptors are simultaneously linked to extracellular ligand and cytoskeletal proteins. Previously, we examined the effect of receptor clustering on attachment strength. Here, we employ the numerical methodology developed by Dembo and colleagues (Dembo, M., D. C. Torney, K. Saxman, and D. Hammer, 1988. Proc. R. Sec. Lend. B. 234:55-83) to investigate the kinetics of cell detachment when receptors are clustered into discrete patches. We show that the membrane peeling velocity decreases if receptors are clustered within a patch located inside the contact region. Peeling of clusters is influenced by the chemistry and mechanics of receptor-ligand bonds within the patch. Detachment is also prohibited if the applied tension equals the critical tension of the patch, unless the patch length is small compared with the boundary length over which membrane bending occurs, in which case the patch will peel. Peeling of these short patches only occurs when the mechanical stiffness of clustered bonds is within an optimal range. We compare our model predictions with experimental measurements of T lymphocyte detachment from ICAM-1 substrates. We demonstrate that if discrete patches of receptors are present, detachment occurs through intervals of slow and fast peeling, similar to the dynamics of T lymphocyte peeling, indicating that clustering of LFA-1 receptors is one possible explanation for the observed detachment kinetics in this system. C1 CORNELL UNIV, SCH CHEM ENGN, ITHACA, NY 14853 USA. LOS ALAMOS NATL LAB, MS K710, LOS ALAMOS, NM 87545 USA. RI Dembo, Micah/C-2755-2013 NR 41 TC 65 Z9 66 U1 0 U2 8 PU CELL PRESS PI CAMBRIDGE PA 600 TECHNOLOGY SQUARE, 5TH FLOOR, CAMBRIDGE, MA 02139 USA SN 0006-3495 EI 1542-0086 J9 BIOPHYS J JI Biophys. J. PD DEC PY 1994 VL 67 IS 6 BP 2522 EP 2534 PG 13 WC Biophysics SC Biophysics GA PV061 UT WOS:A1994PV06100043 PM 7696491 ER PT J AU LONGMIRE, JL RATLIFF, RL AF LONGMIRE, JL RATLIFF, RL TI ENZYMATIC ELONGATION OF MICROSATELLITE OLIGOMERS FOR USE IN DIRECT-LABEL CHEMILUMINESCENT HYBRIDIZATIONS SO BIOTECHNIQUES LA English DT Note ID HUMAN DNA; SEQUENCE AB Short, synthetic oligonucleotide sequences representing microsarellites and other short tandem repents can be elongated (concatamerized) using a simple method in which complementary strands are annealed, phosphorylated, primer extended and ligated. When used in direct-label chemiluminescent hybridizations, the elongated microsatellite sequences provide an approximately 30-fold increase in signal strength compared with microsatellite oligomers that have not been concatamerized. Concatamerization of simple repeat oligomers further enables the use of relatively short oligonucleotide sequences in direct-label chemiluminescent hybridization experiments, thereby reducing the overall need for radioisotopes in certain commonly performed laboratory procedures such as DNA fingerprinting and selection of clones containing microsatellite sequences. RP LONGMIRE, JL (reprint author), LOS ALAMOS NATL LAB, GENOME & STRUCT BIOL GRP, MS-M880, LOS ALAMOS, NM 87545 USA. NR 11 TC 3 Z9 3 U1 0 U2 0 PU BIOTECHNIQUES OFFICE PI NEW YORK PA 52 VANDERBILT AVE, NEW YORK, NY 10017 USA SN 0736-6205 J9 BIOTECHNIQUES JI Biotechniques PD DEC PY 1994 VL 17 IS 6 BP 1090 EP + PG 0 WC Biochemical Research Methods; Biochemistry & Molecular Biology SC Biochemistry & Molecular Biology GA PW017 UT WOS:A1994PW01700014 PM 7873178 ER PT J AU MCNAUGHTON, DJ BOWNE, NE DENNIS, RL DRAXLER, RR HANNA, SR PALMA, T MARSH, SL PENNELL, WT PETERSON, RL RAMSDELL, JV RAO, ST YAMARTINO, RJ AF MCNAUGHTON, DJ BOWNE, NE DENNIS, RL DRAXLER, RR HANNA, SR PALMA, T MARSH, SL PENNELL, WT PETERSON, RL RAMSDELL, JV RAO, ST YAMARTINO, RJ TI SUMMARY OF THE EIGHTH JOINT CONFERENCE ON APPLICATIONS OF AIR-POLLUTION METEOROLOGY SO BULLETIN OF THE AMERICAN METEOROLOGICAL SOCIETY LA English DT Editorial Material AB The Eighth Joint Conference on Applications of Air Pollution Meteorology with the Air and Waste Management Association was held in conjunction with the AMS 74th Annual Meeting in Nashville, Tennessee, on 23-28 January 1994. Sessions at the meeting covered a broad range of topics including the dispersion environment, meteorology in emissions determination, long-range and mesoscale pollutant transport and fate, meteorology and photochemistry, advanced dispersion models and modeling systems, model evaluation, complex flows affecting dispersion neat structures, and coastal and complex terrain issues. Papers followed some recurrent themes but many reported applications of new technology that provide new opportunities to see atmospheric characteristics and complexities for the first time. Innovative techniques were described in data analysis and presentation and modeling. C1 AREAL EPA, NOAA, AIR RESOURCES LAB, RES TRIANGLE PK, NC USA. NOAA, AIR RESOURCES LAB, SILVER SPRING, MD 20910 USA. EARTH TECH, CONCORD, MA USA. TRC ENVIRONM CONSULTANTS, CHAPEL HILL, NC USA. SO CALIF EDISON CO, ROSEMEAD, CA USA. PACIFIC NW LAB, RICHLAND, WA USA. CERMAK PETERKA & PETERSON INC, FT COLLINS, CO USA. NEW YORK STATE DEPT ENVIRONM CONSERVAT, ALBANY, NY USA. RP MCNAUGHTON, DJ (reprint author), EARTH TECH, 19 PROCTOR DR, W HARTFORD, CT 06117 USA. NR 2 TC 0 Z9 0 U1 0 U2 0 PU AMER METEOROLOGICAL SOC PI BOSTON PA 45 BEACON ST, BOSTON, MA 02108-3693 SN 0003-0007 J9 B AM METEOROL SOC JI Bull. Amer. Meteorol. Soc. PD DEC PY 1994 VL 75 IS 12 BP 2303 EP 2311 PG 9 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA QB544 UT WOS:A1994QB54400005 ER PT J AU PENNER, JE CHARLSON, RJ HALES, JM LAULAINEN, NS LEIFER, R NOVAKOV, T OGREN, J RADKE, LF SCHWARTZ, SE TRAVIS, L AF PENNER, JE CHARLSON, RJ HALES, JM LAULAINEN, NS LEIFER, R NOVAKOV, T OGREN, J RADKE, LF SCHWARTZ, SE TRAVIS, L TI QUANTIFYING AND MINIMIZING UNCERTAINTY OF CLIMATE FORCING BY ANTHROPOGENIC AEROSOLS - COMMENT - REPLY SO BULLETIN OF THE AMERICAN METEOROLOGICAL SOCIETY LA English DT Letter ID NITRATE CONCENTRATIONS; SULFATE C1 UNIV WASHINGTON, SEATTLE, WA 98195 USA. PACIFIC NW LAB, RICHLAND, WA USA. ENVIRONM MEASUREMENTS LAB, NEW YORK, NY USA. UNIV CALIF BERKELEY, LAWRENCE BERKELEY LAB, BERKELEY, CA USA. NOAA, CLIMATE MONITORING & DIAGNOST LAB, BOULDER, CO 80303 USA. NATL CTR ATMOSPHER RES, BOULDER, CO 80307 USA. BROOKHAVEN NATL LAB, UPTON, NY 11973 USA. NASA, GODDARD INST SPACE STUDIES, NEW YORK, NY 10025 USA. ENVAIR, RICHLAND, WA USA. RP PENNER, JE (reprint author), LAWRENCE LIVERMORE NATL LAB, LIVERMORE, CA USA. RI Schwartz, Stephen/C-2729-2008; Penner, Joyce/J-1719-2012 OI Schwartz, Stephen/0000-0001-6288-310X; NR 11 TC 1 Z9 1 U1 0 U2 5 PU AMER METEOROLOGICAL SOC PI BOSTON PA 45 BEACON ST, BOSTON, MA 02108-3693 SN 0003-0007 J9 B AM METEOROL SOC JI Bull. Amer. Meteorol. Soc. PD DEC PY 1994 VL 75 IS 12 BP 2315 EP 2316 PG 2 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA QB544 UT WOS:A1994QB54400007 ER PT J AU WESTRICH, HR EICHELBERGER, JC AF WESTRICH, HR EICHELBERGER, JC TI GAS-TRANSPORT AND BUBBLE COLLAPSE IN RHYOLITIC MAGMA - AN EXPERIMENTAL APPROACH SO BULLETIN OF VOLCANOLOGY LA English DT Article DE RHYOLYTES; DEGASSING; VESICULATION; MAGMATIC PROCESSES; WELDING; LAVAS; OBSIDIAN AB A series of experiments was conducted to test concepts of porous flow degassing of rhyolitic magma during ascent and of the subsequent collapse of vesicles in degassed magma to form obsidian. Dense, syn thetically hydrated, natural glasses were pressurized under water-saturated conditions and then decompressed to achieve a range of porosities in the presence of a tracer vapor, D2O. Rapid isotopic exchange indicative of vapor transport rather than of simple diffusion occurred at a porosity >60 vol.%, in accord with earlier gas permeability measurements on cold natural samples. In another series of experiments, natural and synthetic pumices, vesiculated by degassing to atmospheric pressure, rapidly collapsed to dense glass on repressurization to the modest pressures prevailing in lava flows. No relict bubble textures remained. These results support the hypothesis that effusive eruptions result from the syneruptive escape of gas from permeable magmatic foam, and that a process analogous to welding yields dense lavas when such foams are extruded. RP WESTRICH, HR (reprint author), SANDIA NATL LABS,DEPT GEOCHEM,ALBUQUERQUE,NM 87185, USA. RI Eichelberger, John/H-6199-2016 NR 0 TC 67 Z9 67 U1 0 U2 3 PU SPRINGER VERLAG PI NEW YORK PA 175 FIFTH AVE, NEW YORK, NY 10010 SN 0258-8900 J9 B VOLCANOL JI Bull. Volcanol. PD DEC PY 1994 VL 56 IS 6-7 BP 447 EP 458 DI 10.1007/BF00302826 PG 12 WC Geosciences, Multidisciplinary SC Geology GA QA829 UT WOS:A1994QA82900004 ER PT J AU MEZYK, SP BARTELS, DM AF MEZYK, SP BARTELS, DM TI ABSOLUTE RATE-CONSTANT MEASUREMENTS FOR THE REACTION OF ATOMIC-HYDROGEN WITH ACETONE, 2-BUTANONE, PROPIONALDEHYDE, AND BUTYRALDEHYDE IN AQUEOUS-SOLUTION SO CANADIAN JOURNAL OF CHEMISTRY-REVUE CANADIENNE DE CHIMIE LA English DT Article ID HYDRATED ELECTRONS; WATER RADIOLYSIS AB Arrhenius parameters for the reaction of hydrogen atoms with acetone, 2-butanone, propionaldehyde, and butyraldehyde in aqueous solution have been directly measured by electron paramagnetic resonance free induction decay (FID) attenuation measurements. For these compounds, absolute scavenging rate constants at 25 degrees C of (1.97 +/- 0.10) x 10(6), (3.82 +/- 0.32) x 10(7) (8.11 +/- 0.47) x 10(7), and (1.14 +/- 0.07) x 10(8) dm(3) mol(-1) s(-1), with corresponding activation energies of 30.7 +/- 1.3 (7.5-52.8 degrees C), 40.1 +/- 0.7 (8.1-74.5 degrees C), 22.2 +/- 0.9 (8.0-39.0 degrees C) and 23.8 +/- 0.8 (5.4-67.7 degrees C) kJ mol(-1) were measured, respectively. Competition kinetic measurements have established that greater than 95% of .H atom reaction with 2-butanone is by abstraction. C1 ARGONNE NATL LAB,DIV CHEM,ARGONNE,IL 60439. RP MEZYK, SP (reprint author), ATOM ENERGY CANADA LTD,WHITESHELL LABS,RES CHEM BRANCH,PINAWA,MB R0E 1L0,CANADA. NR 29 TC 16 Z9 16 U1 0 U2 2 PU NATL RESEARCH COUNCIL CANADA PI OTTAWA PA RESEARCH JOURNALS, MONTREAL RD, OTTAWA ON K1A 0R6, CANADA SN 0008-4042 J9 CAN J CHEM JI Can. J. Chem.-Rev. Can. Chim. PD DEC PY 1994 VL 72 IS 12 BP 2516 EP 2520 DI 10.1139/v94-318 PG 5 WC Chemistry, Multidisciplinary SC Chemistry GA QC582 UT WOS:A1994QC58200018 ER PT J AU SINHA, R ROTHMAN, N BROWN, ED MARK, SD HOOVER, RN CAPORASO, NE LEVANDER, OA KNIZE, MG LANG, NP KADLUBAR, FF AF SINHA, R ROTHMAN, N BROWN, ED MARK, SD HOOVER, RN CAPORASO, NE LEVANDER, OA KNIZE, MG LANG, NP KADLUBAR, FF TI PAN-FRIED MEAT CONTAINING HIGH-LEVELS OF HETEROCYCLIC AROMATIC-AMINES BUT LOW-LEVELS OF POLYCYCLIC AROMATIC-HYDROCARBONS INDUCES CYTOCHROME P4501A2 ACTIVITY IN HUMANS SO CANCER RESEARCH LA English DT Article ID HUMAN HEPATIC MICROSOMES; CHARCOAL-BROILED BEEF; COOKED FOOD; METABOLIC POLYMORPHISMS; CARCINOGENIC ARYLAMINES; COLORECTAL-CANCER; HUMAN-LIVER; RAT-LIVER; ACTIVATION; INDUCTION AB Heterocyclic aromatic amines (HAAs) are formed when meat juices are pyrolyzed. In humans HAAs are activated in vivo by cytochrome P4501A2 (CYP1A2) and N-acetyltransferase (NAT2) to mutagens or carcinogens. While activity of NAT2 is noninducible, exposure to cigarettes, polycyclic aromatic hydrocarbons, and cruciferous vegetables has been shown to induce CYP1A2 activity in humans. To date, it is unknown if pan-fried meat, which is consumed at high levels in the United States, is capable of inducing CYP1A2. In order to address this issue, we measured CYP1A2 and NAT2 activities in 66 healthy nonsmokers (33 males and 33 females) in a controlled metabolic feeding study. The study was designed to minimize the influence of known inducers of CYP1A2. Subjects consumed meat pan-fried at a low temperature (100 degrees C) for 7 days followed by 7 days of meat pan-fried at a high temperature (250 degrees C) The low temperature-cooked meat had undetectable levels of HAAs while the high temperature-cooked meat contained high amounts of HAAs [9.0 ng/g of 2-amino-3,8-dimethylimidazo[4,5-f]quinoxaline (MeIQx), 2.1 ng/g of 2-amino-3,7,8-trimethylimidazo[4,5-f]quinoxaline (DiMeIQx), and 32.8 ng/g of 2-amino-1-methyl-6-phenylimidazo[4,5-b]pyridine (PhIP)]. In contrast, total polycyclic aromatic hydrocarbon content was similar in both meat samples (10.7 ng/g in low temperature-cooked meat and 10.1 ng/g in high temperature-cooked meat). At the end of each period, subjects were tested for CYP1A2 and NAT2 enzyme activity by caffeine metabolism phenotyping. NAT2 activity remained unchanged throughout the study while CYP1A2 activity increased in 47 of 65 (72%) of the subjects after consuming high temperature-cooked meat (P < 0.0002), suggesting induction by some compound(s) formed during high temperature cooking. If HAAs are shown to be human carcinogens in epidemiological studies, then meat cooked at high temperatures may pose an increased cancer risk because it contains both inducers of CYP1A2 and procarcinogens MeIQx, DiMeIQx, and PhIP known to be activated by this enzyme. C1 USDA ARS, BELTSVILLE AGR RES CTR, NUTR REQUIREMENTS & FUNCT LAB, BELTSVILLE, MD 20705 USA. LAWRENCE LIVERMORE NATL LAB, DIV BIOMED SCI, LIVERMORE, CA 94550 USA. UNIV ARKANSAS MED SCI HOSP, ARKANSAS CANC RES CTR, LITTLE ROCK, AR 72205 USA. NATL CTR TOXICOL RES, JEFFERSON, AR 72079 USA. RP SINHA, R (reprint author), NCI, ENVIRONM EPIDEMIOL BRANCH, EPIDEMIOL & BIOSTAT PROGRAM, EXECUTIVE PLAZA N, ROOM 443, ROCKVILLE, MD 20892 USA. RI Sinha, Rashmi/G-7446-2015 OI Sinha, Rashmi/0000-0002-2466-7462 FU NCI NIH HHS [Y01-CP2-0521, Y01-CP2-0523-01, Y01-CP3-0553] NR 49 TC 160 Z9 161 U1 0 U2 7 PU AMER ASSOC CANCER RESEARCH PI PHILADELPHIA PA 615 CHESTNUT ST, 17TH FLOOR, PHILADELPHIA, PA 19106-4404 USA SN 0008-5472 J9 CANCER RES JI Cancer Res. PD DEC 1 PY 1994 VL 54 IS 23 BP 6154 EP 6159 PG 6 WC Oncology SC Oncology GA PU942 UT WOS:A1994PU94200030 PM 7954461 ER PT J AU THRAVES, PJ VARGHESE, S JUNG, M GRDINA, DJ RHIM, JS DRITSCHILO, A AF THRAVES, PJ VARGHESE, S JUNG, M GRDINA, DJ RHIM, JS DRITSCHILO, A TI TRANSFORMATION OF HUMAN EPIDERMAL-KERATINOCYTES WITH FISSION NEUTRONS SO CARCINOGENESIS LA English DT Article ID RAT EMBRYO CELLS; LOW-DOSE RATE; NEOPLASTIC TRANSFORMATION; SPECTRUM NEUTRONS; K-RAS; P53 MUTATIONS; ONCOGENIC TRANSFORMATION; MALIGNANT TRANSFORMATION; IONIZING-RADIATION; GAMMA-RADIATION AB The biological effects of exposures to high LET radiations have particular relevance to radiation protection and risk assessment. Since most cancers are of epithelial origin, it is important to obtain a better understanding of radiation-induced oncogenic transformation in this cell type. Accordingly we have initiated studies to determine whether immortalized human epidermal keratinocytes (RHEK) can be transformed with high LET radiations. Exponentially growing RHEK cells were treated with single doses (1, 10, 25, 50 and 100 cGy) of 0.85 MeV fission neutrons from the Janus reactor. Neutron exposure led to the development of morphologically altered cells and foci formation after 6 weeks at confluence. These transformed cultures grew with an increased saturation density, exhibited anchorage-independent growth and formed tumors in athymic mice. Single-strand conformational polymorphism analysis and DNA sequencing demonstrated the absence of point mutations in codons 12/13 and 61 in the Ha-ras, Ki-ras, or N-ras genes and exons 4-9 of the p53 tumor suppressor gene. These studies demonstrate that high LET radiations (fission neutrons) can transform immortalized human epithelial cells to a malignant phenotype that does not appear to involve mutations in either the cellular p53 or ras genes. C1 ARGONNE NATL LAB,DIV BIOL & MED RES,ARGONNE,IL 60438. NCI,CELLULAR & MOLEC BIOL LAB,BETHESDA,MD 20892. RP THRAVES, PJ (reprint author), GEORGETOWN UNIV,MED CTR,VINCENT T LOMBARDI CANC RES CTR,DEPT RADIAT MED,WASHINGTON,DC 20007, USA. FU NCI NIH HHS [CA5295, CA 52945] NR 56 TC 5 Z9 5 U1 0 U2 0 PU OXFORD UNIV PRESS UNITED KINGDOM PI OXFORD PA WALTON ST JOURNALS DEPT, OXFORD, ENGLAND OX2 6DP SN 0143-3334 J9 CARCINOGENESIS JI Carcinogenesis PD DEC PY 1994 VL 15 IS 12 BP 2867 EP 2873 DI 10.1093/carcin/15.12.2867 PG 7 WC Oncology SC Oncology GA PZ539 UT WOS:A1994PZ53900029 PM 8001248 ER PT J AU SUH, M JANKOWIAK, R ARIESE, F MAO, B GEACINTOV, NE SMALL, GJ AF SUH, M JANKOWIAK, R ARIESE, F MAO, B GEACINTOV, NE SMALL, GJ TI FLANKING BASE EFFECTS ON THE STRUCTURAL CONFORMATION OF THE (+)-TRANS-ANTI-BENZO[A]PYRENE DIOLEPOXIDE ADDUCT TO N-2-DG IN SEQUENCE-DEFINED OLIGONUCLEOTIDES SO CARCINOGENESIS LA English DT Article ID DIASTEREOMERIC BENZOPYRENE 7,8-DIOL-9,10-EPOXIDES; ESCHERICHIA-COLI PLASMID; INDUCED DNA-STRUCTURE; DIOL-EPOXIDE; MUTAGENIC SPECIFICITY; OPTICAL ENANTIOMERS; (+)-ANTI-DIOL EPOXIDE; MARKED DIFFERENCES; MAMMALIAN-CELLS; BINDING-SITES AB Conformations of the trans adduct of (+)-anti-benzo[a]pyrene -7,8-dihydrodiol-9,10-epoxide (BPDE) to N-2-guanine, the major stable DNA adduct of the environmental carcinogen benzo[a]pyrene, were studied as a function of flanking bases in single-stranded and in double-stranded oligonucleotides. Three 11mer oligonucleotides d(CTAT-G(1)G(2)G(3)TATC) were synthesized containing the (+)-trans-anti-BPDE adduct at one specific guanine of the GGG sequence (a known mutational hot spot). Polyacrylamide gel electrophoresis of the three single-stranded oligonucleotides showed that the adduct bound to G(2) or G(3) (5'-flanking base guanine) caused significantly stronger retardation than the same adduct bound to G(1) (5'-flanking base thymine). The strength of the carcinogen-base interaction was reflected in the spectroscopic properties of the pyrenyl moiety. Low temperature fluorescence measurements under line-narrowing (FLN) or non-line-narrowing (NLN) conditions showed that in single-stranded form the adduct at G(2) or G(3) (5'-flanking base guanine) adopts a conformation with strong interaction with the bases. This was also observed for the same adduct at the sequence AGA. In contrast, the (+)-trans-anti-BPDE adduct with a 5'-flanking thymine exists in a primarily helix-external conformation. Similar differences were observed in the double-stranded oligonucleotides: the adducts at G(2) and G(3) were found to exist in similar conformational equilibria, again with significant carcinogen-base interactions, while the adduct at G(1) showed a predominantly external conformation. The nature of the 3'-flanking base appeared to have little influence on the conformational equilibrium of the (+)-trans-anti-BPDE-guanine adduct. The results could provide insight into the mutational specificity and flanking base effects observed for (+)-anti-BPDE. C1 IOWA STATE UNIV SCI & TECHNOL,US DOE,AMES LAB,AMES,IA 50011. IOWA STATE UNIV SCI & TECHNOL,DEPT CHEM,AMES,IA 50011. NYU,DEPT CHEM,NEW YORK,NY 10003. NR 43 TC 35 Z9 35 U1 0 U2 0 PU OXFORD UNIV PRESS UNITED KINGDOM PI OXFORD PA WALTON ST JOURNALS DEPT, OXFORD, ENGLAND OX2 6DP SN 0143-3334 J9 CARCINOGENESIS JI Carcinogenesis PD DEC PY 1994 VL 15 IS 12 BP 2891 EP 2898 DI 10.1093/carcin/15.12.2891 PG 8 WC Oncology SC Oncology GA PZ539 UT WOS:A1994PZ53900033 PM 8001252 ER PT J AU MCDONALD, MA ZAROCHAK, MF GRAHAM, WJ AF MCDONALD, MA ZAROCHAK, MF GRAHAM, WJ TI EFFECTS OF PRESSURE ON THE OXYHYDROCHLORINATION OF METHANE SO CHEMICAL ENGINEERING SCIENCE LA English DT Article; Proceedings Paper CT 13th International Symposium on Chemical Reaction Engineering - Science and Technology (ISCRE 13) CY SEP 25-28, 1994 CL BALTIMORE, MD SP AMOCO, ARCO, CHEVRON, DU PONT, FORD, MERCK, MOBIL Q, NATL SCI FDN, US DOE, W R GRACE ID FUMED SILICA; LA CATALYSTS; CONVERSION AB Methane was oxyhydrochlorinated over a promoted copper catalyst at total pressures of up to 930 kPa. The catalyst yield increased three-fold as pressure increased from 130 to 930 kPa for relative inlet concentrations of CH4:HCl:O-2 of 5:2:1. Selectivity to CH3Cl decreased as temperature and pressure increased; a higher percentage of polychlorinated methanes and carbon oxides were produced at higher temperature and pressure. The pressure effect on CH3Cl selectivity remained even when corrected for the higher CH4 conversions at higher pressures. Decreasing O-2 concentration in the inlet stream had no major effect on CH3Cl yield, although less CO and CO2 were produced at higher temperatures. Decreasing HCL concentration increased CO2 selectivity at the expense of chloromethane products. C1 GILBERT COMMONWEALTH INC, PHILADELPHIA, PA 15129 USA. RP MCDONALD, MA (reprint author), US DOE, PITTSBURGH ENERGY TECHNOL CTR, POB 10940, PITTSBURGH, PA 15236 USA. NR 15 TC 4 Z9 5 U1 0 U2 1 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLAND SN 0009-2509 EI 1873-4405 J9 CHEM ENG SCI JI Chem. Eng. Sci. PD DEC PY 1994 VL 49 IS 24A BP 4627 EP 4637 PG 11 WC Engineering, Chemical SC Engineering GA QQ520 UT WOS:A1994QQ52000047 ER PT J AU SCHEWEMILLER, IM KOO, KF COLUMBIA, M LI, F SCHRADER, GL AF SCHEWEMILLER, IM KOO, KF COLUMBIA, M LI, F SCHRADER, GL TI SYNTHESIS AND CHARACTERIZATION OF LEAD CHEVREL-PHASE THIN-FILMS FOR HYDRODESULFURIZATION CATALYSIS SO CHEMISTRY OF MATERIALS LA English DT Article ID ELECTRON-SPIN-RESONANCE; X-RAY PHOTOELECTRON; MOLYBDENUM SULFIDE; CO-MO; CONVERSION; PROMOTER; COBALT; NI AB Reactive sputtering has been used to prepare the lead Chevrel phase PbMo6S8 on several substrates. The effect of processing parameters such as H2S flow rate, Pb sputtering current, substrate temperature, and annealing temperature were found to be very important in determining sample purity. Formation of PbMo6S8 from an as-deposited material apparently occurred at significantly lower annealing temperatures (400-800-degrees-C), compared to conventional solid-state preparations (1000-degrees-C). The thin films of PbMo6S8 were active thiophene hydrodesulfurization catalysts: the absence of impurities including MoS2 could be confirmed for these materials, before and after reaction. Because the characteristic catalytic properties of the lead Chevrel phases were observed, reactive sputtering may be applicable for the preparation of other Chevrel phases on catalyst supports. C1 IOWA STATE UNIV SCI & TECHNOL,CTR INTERFACIAL MAT & CRYSTALLIZAT,DEPT CHEM ENGN,AMES,IA 50011. IOWA STATE UNIV SCI & TECHNOL,US DOE,AMES LAB,AMES,IA 50011. NR 54 TC 8 Z9 8 U1 1 U2 2 PU AMER CHEMICAL SOC PI WASHINGTON PA PO BOX 57136, WASHINGTON, DC 20037-0136 SN 0897-4756 J9 CHEM MATER JI Chem. Mat. PD DEC PY 1994 VL 6 IS 12 BP 2327 EP 2335 DI 10.1021/cm00048a019 PG 9 WC Chemistry, Physical; Materials Science, Multidisciplinary SC Chemistry; Materials Science GA PY663 UT WOS:A1994PY66300019 ER PT J AU RUSSO, RE MAO, XL PERRY, DL AF RUSSO, RE MAO, XL PERRY, DL TI MAKE CATALYTIC COATINGS BY PULSED-LASER DEPOSITION - THE TECHNIQUE PRODUCES MULTICOMPONENT INORGANIC FILMS WITH DEFINED COMPOSITION AND STRUCTURE - IT IS ILLUSTRATED BY THE PREPARATION OF A SUPPORTED CANIKO CATALYST SO CHEMTECH LA English DT Article ID O THIN-FILMS; LOW-TEMPERATURE OXYDEHYDROGENATION; METHANE; EVAPORATION; SELECTIVITY; CONVERSION; LAYERS; ALLOYS RP RUSSO, RE (reprint author), UNIV CALIF BERKELEY,LAWRENCE BERKELEY LAB,BERKELEY,CA 94720, USA. NR 17 TC 1 Z9 1 U1 0 U2 0 PU AMER CHEMICAL SOC PI WASHINGTON PA PO BOX 57136, WASHINGTON, DC 20037-0136 SN 0009-2703 J9 CHEMTECH JI Chemtech PD DEC PY 1994 VL 24 IS 12 BP 14 EP 17 PG 4 WC Chemistry, Applied SC Chemistry GA PZ191 UT WOS:A1994PZ19100007 ER PT J AU BOWMAN, JD FRANKLE, CM GREEN, AA KNUDSON, JN PENTTILA, SI SEESTROM, SJ YEN, YF YUAN, VW CRAWFORD, BE ROBERSON, NR GOULD, CR HAASE, DG LOWIE, LY MITCHELL, GE STEPHENSON, SI DELHEIJ, PPJ SHARAPOV, EI POSTMA, H MASUDA, Y SHIMIZU, HM IINUMA, M MASAIKE, A MATSUDA, Y FUKUDA, K AF BOWMAN, JD FRANKLE, CM GREEN, AA KNUDSON, JN PENTTILA, SI SEESTROM, SJ YEN, YF YUAN, VW CRAWFORD, BE ROBERSON, NR GOULD, CR HAASE, DG LOWIE, LY MITCHELL, GE STEPHENSON, SI DELHEIJ, PPJ SHARAPOV, EI POSTMA, H MASUDA, Y SHIMIZU, HM IINUMA, M MASAIKE, A MATSUDA, Y FUKUDA, K TI PARITY VIOLATION IN THE COMPOUND NUCLEUS SO CHINESE JOURNAL OF PHYSICS LA English DT Article; Proceedings Paper CT 1st International Symposium on Symmetries in Subatomic Physics CY MAY 16-18, 1994 CL TAIPEI, TAIWAN ID NEUTRON RESONANCES; FUNDAMENTAL SYMMETRIES; SIGN CORRELATIONS; NONCONSERVATION; STATES; LA-139; TESTS AB The status of parity violation in the compound nucleus is reviewed. The results of previous experimental results obtained by scattering polarized epithermal neutrons from heavy nuclei in the 3-p and 4-p p-wave strength function peaks are presented. Experimental techniques are presented. The extraction of the mean squared matrix element of the parity-violating interaction, M(2), between compound-nuclear level and the relationship of M(2) to the coupling strengths in the meson exchange weak nucleon-nucleon potential are discussed. The tendency of measured asymmetries to have a common sign and theoretical implications are discussed. New experimental results are presented that show that the common sign phenomenon is not universal, as theoretical models developed up to now would predict. This talk is dedicated to our friend and colleague Professor Ernest M. Henley, who has done so much to inspire the understanding and study of fundamental symmetries in the nucleus. C1 DUKE UNIV,DURHAM,NC 27706. N CAROLINA STATE UNIV,RALEIGH,NC 27695. TRIUMF,VANCOUVER,BC VT6 2A3,CANADA. JOINT INST NUCL RES,DUBNA 141980,RUSSIA. DELFT UNIV TECHNOL,2600 GA DELFT,NETHERLANDS. NATL LAB HIGH ENERGY PHYS,TSUKUBA,IBARAKI 305,JAPAN. TUNL,DURHAM,NC. KYOTO UNIV,DEPT PHYS,KYOTO 606,JAPAN. MEIJI COLL ORIENTAL MED,DEPT PHYSIOL,HIYOSHI,KYOTO 629,JAPAN. RP BOWMAN, JD (reprint author), LOS ALAMOS NATL LAB,POB 1663,LOS ALAMOS,NM 87545, USA. RI Gould, Christopher/M-7676-2013; Matsuda, Yasuyuki/C-3007-2008 OI Matsuda, Yasuyuki/0000-0002-9847-3791 NR 23 TC 0 Z9 0 U1 0 U2 1 PU PHYSICAL SOC REPUBLIC CHINA PI TAIPEI PA CHINESE JOURNAL PHYSICS PO BOX 23-30, TAIPEI 10764, TAIWAN SN 0577-9073 J9 CHINESE J PHYS JI Chin. J. Phys. PD DEC PY 1994 VL 32 IS 6 BP 989 EP 1002 PN 2 PG 14 WC Physics, Multidisciplinary SC Physics GA QV524 UT WOS:A1994QV52400008 ER PT J AU FRAUENFELDER, H AF FRAUENFELDER, H TI FROM SYMMETRY TO COMPLEXITY SO CHINESE JOURNAL OF PHYSICS LA English DT Article; Proceedings Paper CT 1st International Symposium on Symmetries in Subatomic Physics CY MAY 16-18, 1994 CL TAIPEI, TAIWAN ID ENERGY LANDSCAPES; PROTEINS; MODEL AB Physics progresses in many directions. Two stand out at the present time, unification and complexity. Here I will try to contrast the two and discuss, using some examples mainly from the work of my own group, the very different role symmetries (and symmetry breaking) have played in advances in both of these directions. I have spent many years on experiments devised to explore symmetries and symmetry breaking. In this endeavor Ernie Henley has been a constant source of inspiration. RP FRAUENFELDER, H (reprint author), LOS ALAMOS NATL LAB,POB 1663,LOS ALAMOS,NM 87545, USA. NR 23 TC 0 Z9 0 U1 0 U2 0 PU PHYSICAL SOC REPUBLIC CHINA PI TAIPEI PA CHINESE JOURNAL PHYSICS PO BOX 23-30, TAIPEI 10764, TAIWAN SN 0577-9073 J9 CHINESE J PHYS JI Chin. J. Phys. PD DEC PY 1994 VL 32 IS 6 BP 1045 EP 1050 PN 2 PG 6 WC Physics, Multidisciplinary SC Physics GA QV524 UT WOS:A1994QV52400012 ER PT J AU KREWALD, S GARVEY, G KOLBE, E LANGANKE, K JESCHONNEK, S AF KREWALD, S GARVEY, G KOLBE, E LANGANKE, K JESCHONNEK, S TI NEUTRINO SCATTERING OFF NUCLEI SO CHINESE JOURNAL OF PHYSICS LA English DT Article; Proceedings Paper CT 1st International Symposium on Symmetries in Subatomic Physics CY MAY 16-18, 1994 CL TAIPEI, TAIWAN AB The ratio of proton-to-neutron neutrino-induced quasielastic yield is a sensitive way to determine the strange quark axial form factor of the nucleon. Final state interactions do not significantly affect the ratio. C1 LOS ALAMOS NATL LAB,LOS ALAMOS,NM 87545. CALTECH,WK KELLOGG RADIAT LAB,PASADENA,CA 91125. RP KREWALD, S (reprint author), KFA JULICH,INST KERNPHYS,JULICH,GERMANY. NR 12 TC 0 Z9 0 U1 0 U2 0 PU PHYSICAL SOC REPUBLIC CHINA PI TAIPEI PA CHINESE JOURNAL PHYSICS PO BOX 23-30, TAIPEI 10764, TAIWAN SN 0577-9073 J9 CHINESE J PHYS JI Chin. J. Phys. PD DEC PY 1994 VL 32 IS 6 BP 1281 EP 1289 PN 2 PG 9 WC Physics, Multidisciplinary SC Physics GA QV524 UT WOS:A1994QV52400032 ER PT J AU SNYDER, F AF SNYDER, F TI METABOLIC PROCESSING OF PAF SO CLINICAL REVIEWS IN ALLERGY LA English DT Review ID PLATELET-ACTIVATING-FACTOR; ACETYL-COA ACETYLTRANSFERASE; HUMAN POLYMORPHONUCLEAR LEUKOCYTES; FACTOR ACETYLHYDROLASE ACTIVITY; ARACHIDONOYL-HYDROLYZING PHOSPHOLIPASE-A2; LOW-DENSITY LIPOPROTEIN; MACROPHAGE CELL-LINE; VASCULAR ENDOTHELIAL-CELLS; PROTEIN-CATALYZED TRANSFER; RAT SPLEEN MICROSOMES RP SNYDER, F (reprint author), OAK RIDGE ASSOCIATED UNIV,OAK RIDGE INST SCI & EDUC,DIV MED SCI,POB 117,OAK RIDGE,TN 37831, USA. FU NHLBI NIH HHS [HL27109-13A1, HL35495-07A1]; NIDDK NIH HHS [R01 DK42804-3A1] NR 169 TC 13 Z9 13 U1 0 U2 1 PU HUMANA PRESS INC PI TOTOWA PA 999 RIVERVIEW DRIVE SUITE 208, TOTOWA, NJ 07012 SN 0731-8235 J9 CLIN REV ALLERG JI Clin. Rev. Allergy PD WIN PY 1994 VL 12 IS 4 BP 309 EP 327 PG 19 WC Allergy SC Allergy GA QG635 UT WOS:A1994QG63500002 PM 7743460 ER PT J AU KELLER, JO BRAMLETTE, TT BARR, PK ALVAREZ, JR AF KELLER, JO BRAMLETTE, TT BARR, PK ALVAREZ, JR TI NOX AND CO EMISSIONS FROM A PULSE COMBUSTOR OPERATING IN A LEAN PREMIXED MODE SO COMBUSTION AND FLAME LA English DT Article; Proceedings Paper CT 25th International Symposium on Combustion CY JUL 31-AUG 05, 1994 CL IRVINE, CA AB Control over the combustion fluid dynamics was used to minimize the emission of NOx and CO. The combustion kinetics were controlled by operating the combustor premixed and were varied by modifying the equivalence ratio over the lean stability envelope. A wide dynamic range in fluid dynamic mixing characteristics was also investigated by modifying the degree of macroscopic mixing and microscopic mixing. The residence time at high temperature was controlled by modifying the frequency of the periodic reacting flow in a pulse combustor. It was found that controlling the flame temperature, chemical kinetics, and residence time at high temperature was best accomplished by controlling the equivalence ratio and the degree of macroscopic mixing rather than controlling the microscopic mixing over the dynamic range obtainable by the techniques used in this study. Emission levels below 5.0 ppm NOx, with corresponding levels of 5.0 ppm CO (corrected to 3% O-2), were achieved in a pulse combustor operating in a lean premixed mode, without the use of any postcombustion cleanup technologies. Both NOx and CO emissions were invariant to changes in the power input. RP KELLER, JO (reprint author), SANDIA NATL LABS,COMBUST RES FACIL,LIVERMORE,CA 94551, USA. NR 18 TC 36 Z9 38 U1 0 U2 3 PU ELSEVIER SCIENCE PUBL CO INC PI NEW YORK PA 655 AVENUE OF THE AMERICAS, NEW YORK, NY 10010 SN 0010-2180 J9 COMBUST FLAME JI Combust. Flame PD DEC PY 1994 VL 99 IS 3-4 BP 460 EP 466 DI 10.1016/0010-2180(94)90037-X PG 7 WC Thermodynamics; Energy & Fuels; Engineering, Multidisciplinary; Engineering, Chemical; Engineering, Mechanical SC Thermodynamics; Energy & Fuels; Engineering GA PX970 UT WOS:A1994PX97000002 ER PT J AU GLARBORG, P MILLER, JA AF GLARBORG, P MILLER, JA TI MECHANISM AND MODELING OF HYDROGEN-CYANIDE OXIDATION IN A FLOW REACTOR SO COMBUSTION AND FLAME LA English DT Article; Proceedings Paper CT 25th International Symposium on Combustion CY JUL 31-AUG 05, 1994 CL IRVINE, CA ID KINETIC DATA-BASE; OXIDE FORMATION; NCO+NO REACTION; NITRIC-OXIDE; PROPELLANT COMBUSTION; ISOCYANIC ACID; NITROUS-OXIDE; CHEMISTRY; N2O; HCN AB The oxidation of hydrogen cyanide under flow reactor conditions (atmospheric pressure, 900-1400 K) has been examined. The study is based mainly on experimental data from the literature on the effect of NO and CO on HCN oxidation, emphasizing N2O formation. However, additional experiments were conducted during the present work in order to investigate the importance of HNCO as an intermediate. The experimental data are compared with model predictions, using a revised reaction mechanism for HCN oxidation. Recent advances in our knowledge of thermodynamic properties for CN, NCO, and HNCO, as well as of the mechanism and rate constants for a number of key reactions have reduced the uncertainty in the model considerably: now model predictions are in good agreement with the experimental data. Compared with the previous HCN oxidation models, particularly the prediction of N2O is significantly improved, aided by better knowledge about the NCO + NO reaction. Under the conditions investigated, the main oxidation route for HCN proceeds through NCO, formed by the reaction the sequence HCN + OH --> CN + H2O, CN + O-2 --> NCO + O. The subsequent reactions of NCO determine the fate of the nitrogen atom. Depending on the gas composition and temperature, NCO is converted to HNCO (by reaction With H2O or HCN), N2O/N-2 (by reaction with NO) or NO (by reaction with O). Both HNCO and N2O are important intermediates in HCN oxidation under these conditions. The present results are significant for understanding the fate of reactive nitrogen in fluidized bed combustion and staged combustion, particularly the formation and destruction of N2O. C1 SANDIA NATL LABS,COMBUST RES FACIL,LIVERMORE,CA 94551. RP GLARBORG, P (reprint author), TECH UNIV DENMARK,DEPT CHEM ENGN,DK-2800 LYNGBY,DENMARK. NR 46 TC 68 Z9 69 U1 1 U2 11 PU ELSEVIER SCIENCE PUBL CO INC PI NEW YORK PA 655 AVENUE OF THE AMERICAS, NEW YORK, NY 10010 SN 0010-2180 J9 COMBUST FLAME JI Combust. Flame PD DEC PY 1994 VL 99 IS 3-4 BP 475 EP 483 DI 10.1016/0010-2180(94)90039-6 PG 9 WC Thermodynamics; Energy & Fuels; Engineering, Multidisciplinary; Engineering, Chemical; Engineering, Mechanical SC Thermodynamics; Energy & Fuels; Engineering GA PX970 UT WOS:A1994PX97000004 ER PT J AU MONAZAM, ER MALONEY, DJ AF MONAZAM, ER MALONEY, DJ TI CHARACTERIZATION OF MASS AND DENSITY DISTRIBUTIONS OF SIZED COAL FRACTIONS SO COMBUSTION AND FLAME LA English DT Article; Proceedings Paper CT 25th International Symposium on Combustion CY JUL 31-AUG 05, 1994 CL IRVINE, CA ID DEVOLATILIZATION; TEMPERATURE; PARTICLES AB Novel measurement systems are applied to characterize external surface area, volume, and drag coefficient/mass (C-d/m) ratios of two sized coal fractions and a sample of carbon spheres. Measurements are made on individual particles with nominal diameters ranging from 75 to 150 mu m. The measurement system incorporates an electrodynamic balance, to isolate particles, with video-based and high-speed diode array imaging systems for particle characterization. Accurate estimates of the Stoke's drag are obtained for the coal particles by applying a general solution method developed for slightly deformed spheres. Analysis methods are developed using shape and drag information to calculate mass and density distributions for the two coals studied. Results of these measurements and analyses' are validated by independent mass measurements using a particle weighing and counting technique. For the coals studied surface area equivalent particle diameters range from 4% to 20% higher than the corresponding volume equivalent particle diameters. Particle densities ranged from 1.01 to 1.34 g/cm(3) for a 23 particle sample set of Pittsburgh seam hva bituminous coal and from 0.81 to 1.38 g/cm(3) for a 30-particle sample set of New Mexico subbituminous coal. From a combustion perspective, the results presented indicate that particle sphere assumptions employed in most combustion models can lead to significant errors (20%-25% on average for the samples studied) in calculated particle volume and associated thermal mass. particle-to-particle density variations indicate that even if surface area and volume differences are adequately handled in a heat transfer analysis, large uncertainties result in particle temperature response due to particle property variations. The measurement and analysis techniques presented are capable of providing the detailed particle property data required for developing improved combustion models. C1 US DOE,MORGANTOWN ENERGY TECHNOL CTR,MORGANTOWN,WV 26507. W VIRGINIA UNIV,DEPT MECH & AEROSP ENGN,MORGANTOWN,WV 26505. NR 20 TC 8 Z9 8 U1 0 U2 3 PU ELSEVIER SCIENCE PUBL CO INC PI NEW YORK PA 655 AVENUE OF THE AMERICAS, NEW YORK, NY 10010 SN 0010-2180 J9 COMBUST FLAME JI Combust. Flame PD DEC PY 1994 VL 99 IS 3-4 BP 733 EP 741 DI 10.1016/0010-2180(94)90068-X PG 9 WC Thermodynamics; Energy & Fuels; Engineering, Multidisciplinary; Engineering, Chemical; Engineering, Mechanical SC Thermodynamics; Energy & Fuels; Engineering GA PX970 UT WOS:A1994PX97000033 ER PT J AU KUHFUSS, TC PHILLIPS, PT AF KUHFUSS, TC PHILLIPS, PT TI ARGONNE-LABS DELIVERS GIGABITS TO THE DESK-TOP SO COMMUNICATIONS NEWS LA English DT Article RP KUHFUSS, TC (reprint author), ARGONNE NATL LAB,ARGONNE,IL 60439, USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU NELSON PUBLISHING PI NOKOMIS PA 2504 NORTH TAMIAMI TRAIL, NOKOMIS, FL 34275-3482 SN 0010-3632 J9 COMMUN NEWS JI Commun. News PD DEC PY 1994 VL 31 IS 12 BP 20 EP 21 PG 2 WC Telecommunications SC Telecommunications GA QA555 UT WOS:A1994QA55500005 ER PT J AU ANDERSON, CE COX, PA JOHNSON, GR MAUDLIN, PJ AF ANDERSON, CE COX, PA JOHNSON, GR MAUDLIN, PJ TI A CONSTITUTIVE FORMULATION FOR ANISOTROPIC MATERIALS SUITABLE FOR WAVE-PROPAGATION COMPUTER-PROGRAMS .2. SO COMPUTATIONAL MECHANICS LA English DT Article ID INTEGRATION; ROTATION AB The constitutive relationships for an anisotropic material are established for shock wave propagation and nonlinear, large deformation computer programs, commonly referred to as hydrocodes. Stresses are formulated in terms of strains; the procedure for separating material compressibility effects (equation of state) from strength effects is formulated which permits the consistent calculation of stresses in the elastic regime, and allows the mean pressure to be defined in accordance with their scalar interpretations. Further, this procedure permits the computation of inelastic response by scaling of deviatoric stresses, so the equivalent stress resides on a yield or failure surface, without changing the pressure. The procedure for computing the equivalent plastic strain and non-radial return to the yield surface, which results from a calculated overstress, is developed. Also, the transformation matrices for large deformation (rotation), necessary for transformation between material and geometric coordinates, are presented. C1 ALLIANT TECHSYST INC,HOPKINS,MN 55343. LOS ALAMOS NATL LAB,LOS ALAMOS,NM 87545. RP ANDERSON, CE (reprint author), SW RES INST,DIV STRUCT SYST & TECHNOL,SAN ANTONIO,TX 78228, USA. NR 17 TC 56 Z9 64 U1 0 U2 10 PU SPRINGER VERLAG PI NEW YORK PA 175 FIFTH AVE, NEW YORK, NY 10010 SN 0178-7675 J9 COMPUT MECH JI Comput. Mech. PD DEC PY 1994 VL 15 IS 3 BP 201 EP 223 DI 10.1007/BF00375030 PG 23 WC Mathematics, Interdisciplinary Applications; Mechanics SC Mathematics; Mechanics GA PX665 UT WOS:A1994PX66500002 ER PT J AU XU, Y MURAL, RJ UBERBACHER, EC AF XU, Y MURAL, RJ UBERBACHER, EC TI CONSTRUCTING GENE MODELS FROM ACCURATELY PREDICTED EXONS - AN APPLICATION OF DYNAMIC-PROGRAMMING SO COMPUTER APPLICATIONS IN THE BIOSCIENCES LA English DT Article ID CODING REGIONS; DNA-SEQUENCES AB This paper presents a computationally efficient algorithm, the Gene Assembly Program III (GAP III), for constructing gene models from a set of accurately-predicted 'exons'. The input to the algorithm is a set of clusters of exon candidates, generated by a new version of the GRAIL coding region recognition system. The exon candidates of a cluster differ in their presumed edges and occasionally in their reading frames. Each exon candidate has a numerical score representing its 'probability' of being an actual exon. GAP III uses a dynamic programming algorithm to construct a gene model, complete or partial, by optimizing a predefined objective function. The optimal gene models constructed by GAP III correspond very well with the structures of genes which have been determined experimentally and reported in the Genome Sequence Database (GSDB). On a test set of 137 human and mouse DNA sequences consisting of 954 true exons, GAP III constructed 137 gene models using 892 exons, among which 859 (859/954 = 90%) are true exons and 33 (33/892 = 3%) are false positive. Among the 859 true positives, 635 (74%) match the actual exons exactly, and 838 (98%) have at least one edge correct. GAP III is computationally efficient. If we use E and C to represent the total number of exon candidates in all clusters and the number of clusters, respectively, the running time of GAP III is proportional to (E x C). C1 OAK RIDGE NATL LAB,DIV ENGN PHYS & MATH,INFORMAT GRP,OAK RIDGE,TN 37831. OAK RIDGE NATL LAB,DIV BIOL,OAK RIDGE,TN 37831. NR 10 TC 59 Z9 60 U1 0 U2 0 PU OXFORD UNIV PRESS UNITED KINGDOM PI OXFORD PA WALTON ST JOURNALS DEPT, OXFORD, ENGLAND OX2 6DP SN 0266-7061 J9 COMPUT APPL BIOSCI JI Comput. Appl. Biosci. PD DEC PY 1994 VL 10 IS 6 BP 613 EP 623 PG 11 WC Computer Science, Interdisciplinary Applications SC Computer Science GA PY746 UT WOS:A1994PY74600005 PM 7704660 ER PT J AU SMITH, SW OVERBEEK, R WOESE, CR GILBERT, W GILLEVET, PM AF SMITH, SW OVERBEEK, R WOESE, CR GILBERT, W GILLEVET, PM TI THE GENETIC DATA ENVIRONMENT AN EXPANDABLE GUI FOR MULTIPLE SEQUENCE-ANALYSIS SO COMPUTER APPLICATIONS IN THE BIOSCIENCES LA English DT Article ID PROGRAMS AB An X-Windows-based graphic user interface is presented which allows the seamless integration of numerous existing biomolecular programs into a single analysis environment. This environment is based on a core multiple sequence editor that is linked to external programs by a user-expandable menu system and is supported on Sun and DEC workstations. There is no limitation to the number of external functions that can be linked to the interface. The length and number of sequences that can be handled are limited only by the size of virtual memory present on the workstation, The sequence data itself is used as the reference point from which analysis is done, and scalable graphic views are supported. It is suggested that future software development utilizing this expandable, user-defined menu system and the I/O linkage of external programs will allow biologists to easily integrate expertise from disparate fields into a single environment. C1 NIH,NATL CTR HUMAN GENOME RES,BETHESDA,MD 20892. MILLIPORE BIOIMAGE,ANN ARBOR,MI. ARGONNE NATL LAB,DIV MATH & COMP SCI,ARGONNE,IL 60439. UNIV ILLINOIS,DEPT MICROBIOL,URBANA,IL 61801. HARVARD UNIV,HARVARD GENOME LAB,CAMBRIDGE,MA 02138. FU NHGRI NIH HHS [R01 HG00124] NR 20 TC 427 Z9 431 U1 0 U2 3 PU OXFORD UNIV PRESS UNITED KINGDOM PI OXFORD PA WALTON ST JOURNALS DEPT, OXFORD, ENGLAND OX2 6DP SN 0266-7061 J9 COMPUT APPL BIOSCI JI Comput. Appl. Biosci. PD DEC PY 1994 VL 10 IS 6 BP 671 EP 675 PG 5 WC Computer Science, Interdisciplinary Applications SC Computer Science GA PY746 UT WOS:A1994PY74600011 PM 7704666 ER PT J AU GYULASSY, M WANG, XN AF GYULASSY, M WANG, XN TI HIJING-1.0 - A MONTE-CARLO PROGRAM FOR PARTON AND PARTICLE-PRODUCTION IN HIGH-ENERGY HADRONIC AND NUCLEAR COLLISIONS SO COMPUTER PHYSICS COMMUNICATIONS LA English DT Article DE RELATIVISTIC HEAVY ION COLLISIONS; QUARK-GLUON PLASMA; PARTONS; HADRONS; NUCLEI; JETS; MINIJETS; PARTICLE PRODUCTION; PARTON SHADOWING; JET QUENCHING ID QUARK-GLUON PLASMA; FRAGMENTATION MODEL; JET FRAGMENTATION; CROSS-SECTIONS; SMALL VALUES; E+E-PHYSICS; QCD; SCATTERING; MINIJETS; MATTER AB Based on QCD-inspired models for multiple jets production, we developed a Monte Carlo program to study jet and the associated particle production in high energy pp, pA and AA collisions. The physics behind the program which includes multiple minijet production, soft excitation, nuclear shadowing of parton distribution functions and jet interaction in dense matter is briefly discussed. A detailed description of the program and instructions on how to use it are given. C1 UNIV CALIF BERKELEY,LAWRENCE BERKELEY LAB,DIV NUCL SCI,BERKELEY,CA 94720. RP GYULASSY, M (reprint author), COLUMBIA UNIV,DEPT PHYS,538 W 120TH ST,NEW YORK,NY 10027, USA. OI Wang, Xin-Nian/0000-0002-9734-9967 NR 48 TC 518 Z9 523 U1 0 U2 3 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0010-4655 J9 COMPUT PHYS COMMUN JI Comput. Phys. Commun. PD DEC PY 1994 VL 83 IS 2-3 BP 307 EP 331 DI 10.1016/0010-4655(94)90057-4 PG 25 WC Computer Science, Interdisciplinary Applications; Physics, Mathematical SC Computer Science; Physics GA PV422 UT WOS:A1994PV42200017 ER PT J AU DALE, VH PEARSON, SM OFFERMAN, HL ONEILL, RV AF DALE, VH PEARSON, SM OFFERMAN, HL ONEILL, RV TI RELATING PATTERNS OF LAND-USE CHANGE TO FAUNAL BIODIVERSITY IN THE CENTRAL AMAZON SO CONSERVATION BIOLOGY LA English DT Article AB Large-scale deforestation in threatening the diversity of tropical forests. Given the paucity of data on life-history characteristics of tropical species, methods are needed to identify those species susceptible to extirpation following forest fragmentation. The approach developed in this paper provides a method to examine potential effects of forest fragmentation on biodiversity considering both land-use changes and traits of susceptible species. Based on certain behavioral characteristics, the effects on forest fragmentation in the Brazilian Amazon were projected for nine groups on animals. The taxonomically diverse species were characterized by gap-crossing ability and area requirements. The probability of local extinction due to destruction of habitat over a 40-year period was estimated for these animal groups under three scenarios of land-use practice, projected with a computer model. These scenarios include the typical land use of central Rondonia, Brazil, and two extremes of land-use practice that bracket the range of possible agricultural land-use changes. Animals with gap-crossing ability proportional to area requirements respond similarly to fragmentation, regardless of their taxonomic affiliation. The available habitat for those species in proportional to the amount of remaining forest under all three agricultural management scenarios. In contrast, species that have large area requirements but that will cross only small gaps are more adversely affects by forest fragmentation. The available habitat for such species is reduced at a rate disproportionately greater than the rate of forest clearing. For a tropical frog, the effects of forest fragmentation were evaluated considering not only gap-crossing ability and area requirement but also specialized habitat requirements and edge effects. For the worst-case scenario of land management, gap-crossing ability and area requirements of the tropical frog imply that only 60% of the forest remaining after seven years of management is suitable habitat. Considering breeding habitat requirements and possible edge effects further reduces the suitable habitat to 39% of the remaining forest. These reductions in the proportion of suitable forest area are likely to change with rate and spatial pattern of forest loss. RP DALE, VH (reprint author), OAK RIDGE NATL LAB,DIV ENVIRONM SCI,OAK RIDGE,TN 37831, USA. RI Dale, Virginia/B-6023-2009 NR 0 TC 117 Z9 123 U1 9 U2 80 PU BLACKWELL SCIENCE PUBL INC CAMBRIDGE PI CAMBRIDGE PA 238 MAIN ST, CAMBRIDGE, MA 02142 SN 0888-8892 J9 CONSERV BIOL JI Conserv. Biol. PD DEC PY 1994 VL 8 IS 4 BP 1027 EP 1036 DI 10.1046/j.1523-1739.1994.08041027.x PG 10 WC Biodiversity Conservation; Ecology; Environmental Sciences SC Biodiversity & Conservation; Environmental Sciences & Ecology GA PZ557 UT WOS:A1994PZ55700020 ER PT J AU EDGEMON, GL MAREK, M WILSON, DF BELL, GEC AF EDGEMON, GL MAREK, M WILSON, DF BELL, GEC TI SENSITIZATION BEHAVIOR OF ALLOY 800H AS CHARACTERIZED BY THE ELECTROCHEMICAL POTENTIOKINETIC REACTIVATION (EPR) TECHNIQUE SO CORROSION LA English DT Article DE ALLOY 800H; AUSTENITIC; ELECTROCHEMICAL POTENTIOKINETIC REACTIVATION TEST; PASSIVATION; REACTIVATION; SENSITIZATION; TYPE 304 STAINLESS STEEL; UNS N08810; UNS S30400 ID INTERGRANULAR CORROSION; STAINLESS-STEELS; SUSCEPTIBILITY AB The need for a nondestructive test to evaluate levels of sensitization in alloy 800H (UNS N08810) led to modification of the electrochemical potentiokinetic reactivation (EPR) test technique previously developed for type 304 (UNS S30400) stainless steel (SS). Results of testing on alloy 800H specimens aged at temperatures between 450 degrees C and 700 degrees C for 0 h to 5,000 h indicated that sensitized materials exhibited a peak in measured current density resulting from activation of grain boundaries at -30 mV(SCE) in addition to a general surface activation peak at -150 mV(SCE). Unsensitized material exhibited only the general surface activation peak. It was shown that methods of data analysis previously used for type 304 SS utilizing the integrated area under the reactivation curve cannot be applied to alloy 800H because of the dual peak nature of the EPR curve. instead i(pn) (current density normalized to grain boundary area at a specimen potential of -30 mV(SCE)) must be used. A i(pn) value > similar to 1.6 x 10(4) mu A/cm(2) of grain boundary area corresponded to complete grain encirclement and grain boundary ditching. Using this criterion and the aging conditions investigated, a time-temperature sensitization profile was generated for alloy 800H. C1 GEORGIA INST TECHNOL,ATLANTA,GA 30332. OAK RIDGE NATL LAB,OAK RIDGE,TN 37831. M J SCHIFF & ASSOCIATES,CLAREMONT,CA 91711. NR 9 TC 6 Z9 6 U1 0 U2 0 PU NATL ASSN CORROSION ENG PI HOUSTON PA 1440 SOUTH CREEK DRIVE, HOUSTON, TX 77084-4906 SN 0010-9312 J9 CORROSION JI Corrosion PD DEC PY 1994 VL 50 IS 12 BP 912 EP 918 PG 7 WC Materials Science, Multidisciplinary; Metallurgy & Metallurgical Engineering SC Materials Science; Metallurgy & Metallurgical Engineering GA RL384 UT WOS:A1994RL38400002 ER PT J AU BRUEMMER, SM SIMONEN, EP AF BRUEMMER, SM SIMONEN, EP TI RADIATION HARDENING AND RADIATION-INDUCED CHROMIUM DEPLETION EFFECTS ON INTERGRANULAR STRESS-CORROSION CRACKING IN AUSTENITIC STAINLESS-STEELS SO CORROSION LA English DT Article DE CHROMIUM DEPLETION; CRACKING; HARDENING; INTERGRANULAR STRESS CORROSION CRACKING; IRRADIATION-ASSISTED STRESS CORROSION CRACKING; IRRADIATION EFFECTS; RADIATION-INDUCED SEGREGATION; SEGREGATION; SENSITIZATION; STRESS CORROSION CRACKING ID NEUTRON-IRRADIATION; INDUCED SEGREGATION; ALLOYS AB Radiation hardening and radiation-induced chromium (Cr) depletion were related to intergranular stress corrosion cracking (IGSCC) response among various stainless steels (SS). Available data on neutron-irradiated materials were analyzed and correlations developed between fluence, yield strength, grain-boundary Cr concentration, and cracking susceptibility in high-temperature water environments. Large heat-to-heat differences in the critical fluence (0.2 neutrons/cm(2) to 2.5 x 10(21) neutrons/cm(2)) for IGSCC were documented. Variability often was consistent with yield strength differences among irradiated materials. IGSCC correlated better to yield strength than to fluence for most heats, suggesting a possible role for radiation-induced hardening (and microstructure) on cracking. However, isolated heats revealed a wide range of yield strengths (450 MPa to 800 MPa) necessary to promote IGSCC which could not be explained by strength effects alone. Grain-boundary Cr depletion qualitatively explained differences in IGSCC susceptibility for irradiated SS. Examination of measured Cr content vs SCC showed that all materials showing IG cracking had some grain-boundary depletion (greater than or equal to 2%). Grain-boundary Cr concentrations for cracking (< similar to 16 wt%) were in good agreement with results from similar SCC tests on unirradiated type 304 SS (UNS S30400) with controlled depletion profiles. Heats that prompted variability in the yield strength correlation were accounted for by differences in their interfacial Cr contents. Thus, certain SS apparently were more resistant to cracking, even though they had significant radiation-induced Cr depletion. Cr depletion was believed to be required for SCC of irradiated SS, but susceptibility in this study was modified by other microchemical and microstructural components. RP BRUEMMER, SM (reprint author), PACIFIC NW LAB, POB 999, RICHLAND, WA 99352 USA. NR 33 TC 14 Z9 15 U1 0 U2 1 PU NATL ASSN CORROSION ENG PI HOUSTON PA 1440 SOUTH CREEK DRIVE, HOUSTON, TX 77084-4906 SN 0010-9312 J9 CORROSION JI Corrosion PD DEC PY 1994 VL 50 IS 12 BP 940 EP 946 PG 7 WC Materials Science, Multidisciplinary; Metallurgy & Metallurgical Engineering SC Materials Science; Metallurgy & Metallurgical Engineering GA RL384 UT WOS:A1994RL38400005 ER PT J AU BRISSON, JG SWIFT, GW AF BRISSON, JG SWIFT, GW TI MEASUREMENTS AND MODELING OF RECUPERATOR FOR SUPERFLUID STIRLING REFRIGERATOR SO CRYOGENICS LA English DT Article DE RECUPERATOR; STIRLING REFRIGERATOR; SUPERFLUID; MEASUREMENTS AND MODELING AB Measurements and several methods of modelling of a recuperator for use in a dual superfluid Stirling refrigerator are discussed. The models are also applicable to non-superfluid machines. The heat capacity of the fluid entrained in the recuperator is essential for its efficient operation if the piston motions are sinusoidal. C1 LOS ALAMOS NATL LAB,CONDENSED MATTER & THERMAL PHYS GRP,LOS ALAMOS,NM 87545. NR 13 TC 11 Z9 11 U1 0 U2 0 PU BUTTERWORTH-HEINEMANN LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD, OXON, ENGLAND OX5 1GB SN 0011-2275 J9 CRYOGENICS JI Cryogenics PD DEC PY 1994 VL 34 IS 12 BP 971 EP 982 DI 10.1016/0011-2275(94)90089-2 PG 12 WC Thermodynamics; Physics, Applied SC Thermodynamics; Physics GA PU203 UT WOS:A1994PU20300001 ER PT J AU BRENAN, JM SHAW, HF PHINNEY, DL RYERSON, FJ AF BRENAN, JM SHAW, HF PHINNEY, DL RYERSON, FJ TI RUTILE-AQUEOUS FLUID PARTITIONING OF NB, TA, HF, ZR, U AND TH - IMPLICATIONS FOR HIGH-FIELD STRENGTH ELEMENT DEPLETIONS IN ISLAND-ARC BASALTS SO EARTH AND PLANETARY SCIENCE LETTERS LA English DT Article ID ION-MICROPROBE; MELT EXTRACTION; HIGH-PRESSURE; WATER-LOSS; SUBDUCTION; MAGMAS; CONSTRAINTS; MANTLE; AMPHIBOLITES; SYSTEMATICS AB To assess the possible role of residual rutile in the retention of high field strength elements (HFSEs) during dehydration of a subducting slab we have measured rutile/aqueous fluid partition coefficients (D-rut/fl) for Nb, Ta, Kf, Zr, U and Th at 1-2 GPa and 900-1100 degrees C. Partition coefficients for Nb, Ta, Hf and Zr are all in excess of 100 at 900 degrees C and 1.0 GPa and values become larger with increasing pressure or decreasing temperature. Partition coefficients for U6+ and Th are lower(similar to 2 and 2000 times, respectively) than those for the HFSEs, and trends in D-rut/fl with ionic radius indicate that cations with a large radius (i.e., > 0.8 Angstrom), including U4+, will have partition coefficients < 1. Results indicate that rutile will therefore selectively deplete coexisting fluids in HFSEs relative to large ion lithophile elements (LILEs). Calculations using these partition coefficients show that only small amounts of residual rutile (similar to 0.2wt%) are required to prevent HFSE enrichment of the mantle wedge by fluids derived from either pelagic sediments or the basaltic portion of the subducting slab. In addition, the measured HFSE concentrations of rutiles from eclogite-facies oceanic gabbros from the Rocciavre Massif (Western Alps) indicate that fluids that may have equilibrated with such rocks are strongly depleted in HFSEs and therefore would have no capacity to alter the HFSE content of the subarc mantle. We conclude that fluids derived from slab dehydration can be sufficiently depleted in HFSEs that subsequent enrichment of these elements in the mantle wedge does not occur. Uncertainty still remains, however, with regard to the capacity of such fluids to achieve the necessary enrichments in LILEs inferred for the subarc mantle. C1 LAWRENCE LIVERMORE NATL LAB,DIV NUCL CHEM,LIVERMORE,CA 94551. RP BRENAN, JM (reprint author), LAWRENCE LIVERMORE NATL LAB,DEPT EARTH SCI,POB 808,L-202,LIVERMORE,CA 94551, USA. RI Shaw, Henry/B-6445-2012 OI Shaw, Henry/0000-0003-0681-5430 NR 47 TC 276 Z9 294 U1 2 U2 51 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0012-821X J9 EARTH PLANET SC LETT JI Earth Planet. Sci. Lett. PD DEC PY 1994 VL 128 IS 3-4 BP 327 EP 339 DI 10.1016/0012-821X(94)90154-6 PG 13 WC Geochemistry & Geophysics SC Geochemistry & Geophysics GA QC238 UT WOS:A1994QC23800021 ER PT J AU LUNDSTROM, CC SHAW, HF RYERSON, FJ PHINNEY, DL GILL, JB WILLIAMS, Q AF LUNDSTROM, CC SHAW, HF RYERSON, FJ PHINNEY, DL GILL, JB WILLIAMS, Q TI COMPOSITIONAL CONTROLS ON THE PARTITIONING OF U, TH, BA, PB, SR AND ZR BETWEEN CLINOPYROXENE AND HAPLOBASALTIC MELTS - IMPLICATIONS FOR URANIUM SERIES DISEQUILIBRIA IN BASALTS SO EARTH AND PLANETARY SCIENCE LETTERS LA English DT Article ID MIDOCEAN RIDGE BASALTS; RARE-EARTH ELEMENTS; ION-MICROPROBE; TH-230 DISEQUILIBRIUM; TRACE-ELEMENTS; LIQUID; GARNET; MAGMA; GENERATION; PERIDOTITE AB The partitioning of U, Th, Pb, Sr, Zr and Ba between coexisting chromian diopsides and haplobasaltic liquids at oxygen fugacities between the iron-wustite buffer and air at 1285 degrees C has been characterized using secondary ion mass spectrometry. The partition coefficients for Th, U and Zr show a strong dependence on the Al and Na content of the clinopyroxene. A good correlation between Al-IV and D-Th exists for all recent Th partitioning studies, providing a simple explanation for the two order of magnitude variation in D-Th observed in this and previous studies [1,2]. Because mantle clinopyroxenes generally have greater than 5 wt% Al2O3 we suggest that the relevant partition coefficients for U and Th are between 0.01 and 0.02. While variations in Al and Na in clinopyroxene affect the absolute value of the Th and U partition coefficients, they have no effect on their ratio, D-Th/D-U. Our results reinforce the inference that equilibrium partitioning of U and Th between clinopyroxene and melt cannot explain the observed Th-230 excesses in basalts. Indeed, under the oxygen fugacities relevant to MORE petrogenesis, clinopyroxene has little ability to fractionate U from Th (D-Th/D-U <2), implying that chemical disequilibrium between melt and wall rock during transport is not required to preserve Th-230 excesses generated in the garnet stability field. If the Ba partition coefficient serves as an analog for Ra and the partition coefficient of U5+ serves as an analog for Pasi, then Ra-226 and Pa-231 excesses can be generated by clinopyroxene-melt partitioning. Using compositionally dependent partition coefficients, a melting model is used to show that equilibrium porous flow can explain variations in uranium series activities from the East Pacific Rise by varying the depth of melting. C1 LAWRENCE LIVERMORE NATL LAB,DIV EARTH SCI,LIVERMORE,CA 94550. LAWRENCE LIVERMORE NATL LAB,INST GEOPHYS & PLANETARY PHYS,LIVERMORE,CA 94550. LAWRENCE LIVERMORE NATL LAB,DIV NUCL CHEM,LIVERMORE,CA 94550. UNIV CALIF SANTA CRUZ,INST TECTON,SANTA CRUZ,CA 95064. RP LUNDSTROM, CC (reprint author), UNIV CALIF SANTA CRUZ,EARTH SCI BOARD,SANTA CRUZ,CA 95064, USA. RI Shaw, Henry/B-6445-2012 OI Shaw, Henry/0000-0003-0681-5430 NR 42 TC 114 Z9 114 U1 2 U2 15 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0012-821X J9 EARTH PLANET SC LETT JI Earth Planet. Sci. Lett. PD DEC PY 1994 VL 128 IS 3-4 BP 407 EP 423 DI 10.1016/0012-821X(94)90159-7 PG 17 WC Geochemistry & Geophysics SC Geochemistry & Geophysics GA QC238 UT WOS:A1994QC23800026 ER PT J AU GOFF, F GARDNER, JN AF GOFF, F GARDNER, JN TI EVOLUTION OF A MINERALIZED GEOTHERMAL SYSTEM, VALLES CALDERA, NEW-MEXICO SO ECONOMIC GEOLOGY AND THE BULLETIN OF THE SOCIETY OF ECONOMIC GEOLOGISTS LA English DT Review ID JEMEZ VOLCANIC FIELD; SAN-JUAN MOUNTAINS; HYDROTHERMAL SYSTEMS; CORE HOLE; BANDELIER TUFF; TOLEDO CALDERA; REDONDO DOME; FLUIDS; RESERVOIR; ISOTOPE AB The 20-km-diam Valles caldera formed at 1.13 Ma and had continuous postcaldera rhyolitic eruptions until 0.13 Ma. Hot springs and fumaroles are surface manifestations of a hydrothermal reservoir (210 degrees-300 degrees C; 2-10 X 10(3) mg/kg Cl) that is most extensive in fractured, caldera fill tuffs and associated sedimentary rocks, located in specific structural zones. Fluids are composed of deeply circulating water of (primarily) meteoric origin that have a mean residence time in the reservoir of 3 to 10 k.y. The only component of clearly magmatic origin is anomalous He-3 although it is possible that some magmatic water, carbon, and sulfur is contributed to present hydrothermal fluids. Host rocks show intense isotopic exchange with hydrothermal fluids. Alteration assemblages are controlled by temperature, permeability, fluid composition, host-rock type, and depth. A generalized distribution from top to bottom of the system consists of argillic, phyllic, propylitic, and calc-silicate assemblages. Typical alteration minerals in phyllic and propylitic zones are quartz, calcite, illite, chlorite, epidote, and pyrite, whereas common vein minerals consist of the above minerals plus fluorite, adularia, and wairakite. Argentiferous pyrite, pyrargyrite, molybdenite, sphalerite, galena, chalcopyrite, arsenopyrite, stibnite, barite, and tetradymite (?) have been found at various depths in the Valles system. Fluid inclusion studies show that these mineral assemblages formed from liquid water (0-5.5 wt % NaCl equiv) at temperatures ranging from 175 degrees to 310 degrees C, depending on location in the system. Fluid inclusion studies also show that the top of the liquid-dominated zone has descended, leaving behind a low-pressure vapor cap. Dating of spring deposits, core samples of vein minerals, and altered host rocks by K-Ar, U-Th, U-U, and paleomagnetic methods indicates that the hydrothermal system was created at about 1.0 Ma and has been continuously active to the present. However, these dates in combination with geologic and fluid inclusion evidence suggest that the vapor zone formed at about 0.5 Ma, after a breach of the southwest caldera wall drained widespread intracaldera lakes and lowered the hydraulic head on the hydrothermal reservoir. Although petrologic and geophysical evidence indicates that residual pockets of melt still reside in the pluton beneath the caldera, the size of the hydrothermal system has shrunk since initial formation. Thus, the Valles caldera contains a mature hydrothermal system that remains hot, that contains a classic geothermal configuration, and that displays many analogies to epithermal mineral deposits exposed in older volcanic environments. RP GOFF, F (reprint author), LOS ALAMOS NATL LAB,LOS ALAMOS,NM 87545, USA. NR 103 TC 34 Z9 34 U1 1 U2 12 PU ECONOMIC GEOLOGY PUBL CO PI EL PASO PA UNIV TEXAS AT EL PASO ROOM 202 QUINN HALL, EL PASO, TX 79968 SN 0361-0128 J9 ECON GEOL BULL SOC JI Econ. Geol. Bull. Soc. Econ. Geol. PD DEC PY 1994 VL 89 IS 8 BP 1803 EP 1832 PG 30 WC Geochemistry & Geophysics SC Geochemistry & Geophysics GA QK973 UT WOS:A1994QK97300009 ER PT J AU HIRST, E AF HIRST, E TI HOW COMPETITION MIGHT AFFECT ELECTRIC-UTILITY DSM PROGRAMS SO ENERGY LA English DT Article AB This paper discusses competition in the electricity industry and how it might affect utility DSM programs. The roles that state regulatory commissions could play to affect retail competition and DSM programs are examined. Commissions could set exit or reentry fees for customers who want to buy electricity from an entity other than the local utility. Or they could 'tax' the use of the local distribution system to discourage uneconomic wheeling and to pay for DSM programs. The effects of DSM programs on retail electricity prices and how utilities might redesign their DSM programs for a more competitive environment are considered. In the future, utility DSM programs may (1) focus more on customer service and less on system-resource benefits, (2) emphasize capacity reductions more and energy savings less as utilities seek to minimize the lost revenues associated with DSM, (3) become more cost-effective as utilities identify better ways to deliver DSM services at lower cost, and (4) involve fewer inter- and intraclass transfers as utilities increasingly have individual customers pay for their own DSM services. While DSM programs in the future may be different from what they are today, they will continue to be important to utilities as powerful marketing tools and to society because of their environmental and economic-productivity benefits. RP HIRST, E (reprint author), OAK RIDGE NATL LAB,OAK RIDGE,TN 37831, USA. NR 22 TC 1 Z9 1 U1 0 U2 0 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD, ENGLAND OX5 1GB SN 0360-5442 J9 ENERGY JI Energy PD DEC PY 1994 VL 19 IS 12 BP 1193 EP 1203 DI 10.1016/0360-5442(94)90021-3 PG 11 WC Thermodynamics; Energy & Fuels SC Thermodynamics; Energy & Fuels GA PY021 UT WOS:A1994PY02100001 ER PT J AU Gilbert, RO AF Gilbert, Richard O. TI Statistical evaluation of the attainment of interim cleanup standards at hazardous waste sites Discussion SO ENVIRONMENTAL AND ECOLOGICAL STATISTICS LA English DT Editorial Material C1 Pacific Northwest Lab, Environm Stat Grp, Analyt Sci & Engn Dept, Richland, WA 99354 USA. RP Gilbert, RO (reprint author), Pacific Northwest Lab, Environm Stat Grp, Analyt Sci & Engn Dept, Richland, WA 99354 USA. NR 5 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 DEC PY 1994 VL 1 IS 4 BP 348 EP 349 DI 10.1007/BF00469431 PG 2 WC Environmental Sciences; Mathematics, Interdisciplinary Applications; Statistics & Probability SC Environmental Sciences & Ecology; Mathematics GA V31TN UT WOS:000208906000007 ER PT J AU ANDERSON, S SADINSKI, W SHUGART, L BRUSSARD, P DEPLEDGE, M FORD, T HOSE, J STEGEMAN, J SUK, W WIRGIN, I WOGAN, G AF ANDERSON, S SADINSKI, W SHUGART, L BRUSSARD, P DEPLEDGE, M FORD, T HOSE, J STEGEMAN, J SUK, W WIRGIN, I WOGAN, G TI GENETIC AND MOLECULAR ECOTOXICOLOGY - A RESEARCH FRAMEWORK SO ENVIRONMENTAL HEALTH PERSPECTIVES LA English DT Article DE GENETIC; MOLECULAR; ECOTOXICOLOGY; BIOMARKERS; GENOTYPES; GENOTOXIC; GLOBAL POLLUTION; POPULATIONS; ECOSYSTEMS; BIODIVERSITY; HAZARDOUS SUBSTANCES AB Participants at the Napa Conference on Genetic and Molecular Ecotoxicology assessed the status of this field in light of heightened concerns about the genetic effects of exposure to hazardous substances and recent advancements in our capabilities to measure those effects. We present here a synthesis of the ideas discussed throughout the conference, including definitions of import:ant concepts in the field and critical research needs and opportunities. While there were many opinions expressed on these topics. there was general agreement that there are substantive new opportunities to improve the impact of genetic and molecular ecotoxicology on prediction of sublethal effects of exposure to hazardous substances. Future studies should emphasize integration of genetic ecotoxicology, ecological genetics, and molecular biology and should be directed toward improving our understanding of the ecological implications of genotoxic responses. Ecological implications may be assessed at either the population or ecosystem level; however, a population-level focus may be most pragmatic. Recent technical advancements in measuring genetic and molecular responses to toxicant exposure will spur rapid progress. These new techniques have considerable promise for increasing our understanding of both mechanisms of toxicity on genes or gene products and the relevance of detrimental effects to individual fitness. C1 OAK RIDGE NATL LAB,OAK RIDGE,TN. UNIV NEVADA,RENO,NV 89557. UNIV PLYMOUTH,PLYMOUTH PL4 8AA,DEVON,ENGLAND. HARVARD UNIV,CAMBRIDGE,MA 02138. OCCIDENTAL COLL,LOS ANGELES,CA 90041. WOODS HOLE OCEANOG INST,WOODS HOLE,MA 02543. NIEHS,RES TRIANGLE PK,NC 27709. NYU,MED CTR,TUXEDO PK,NY. MIT,CAMBRIDGE,MA 02139. RP ANDERSON, S (reprint author), UNIV CALIF BERKELEY,LAWRENCE BERKELEY LAB,BLDG 70-193A,1 CYCLOTRON RD,BERKELEY,CA 94708, USA. NR 33 TC 97 Z9 105 U1 0 U2 8 PU NATL INST ENVIRON HEALTH SCI PI RES TRIANGLE PK PA PO BOX 12233, RES TRIANGLE PK, NC 27709 SN 0091-6765 J9 ENVIRON HEALTH PERSP JI Environ. Health Perspect. PD DEC PY 1994 VL 102 SU 12 BP 3 EP 8 PG 6 WC Environmental Sciences; Public, Environmental & Occupational Health; Toxicology SC Environmental Sciences & Ecology; Public, Environmental & Occupational Health; Toxicology GA QE659 UT WOS:A1994QE65900001 PM 7713030 ER PT J AU ANDERSON, SL WILD, GC AF ANDERSON, SL WILD, GC TI LINKING GENOTOXIC RESPONSES AND REPRODUCTIVE SUCCESS IN ECOTOXICOLOGY SO ENVIRONMENTAL HEALTH PERSPECTIVES LA English DT Article; Proceedings Paper CT Napa Conference on Genetic and Molecular Ecotoxicology CY OCT 12-15, 1993 CL YOUNTVILLE, CA DE GENOTOXICITY; MUTAGENESIS; REPRODUCTION; CYTOGENETICS; CAENORHABDITIS ELEGANS; AMPHIBIA; POLYCHAETE; SEA URCHIN; FISH ID CAENORHABDITIS-ELEGANS; ORYZIAS-LATIPES; RADIATION; METAMORPHOSIS; MUTAGENESIS; MUTATION; FISH AB The potential of genotoxicity biomarkers as predictors of detrimental environmental effects, such as altered reproductive success of wild organisms, must be rigorously determined. Recent research to evaluate relationships between genotoxic responses and indicators of reproductive success in model animals is described from an ecotoxicological perspective. Genotoxicity can be correlated with reproductive effects such as gamete loss due to cell death; embryonic mortality; and heritable mutations in a range of model animals including polychaete worms, nematodes, sea urchins, amphibians, and fish. In preliminary studies, the polychaete worm, Neanthes arenaceodentata, and the nematode, Caenorhabditis elegans, have also shown the potential for cumulative DNA damage in gametes. If DNA repair capacity is limited in gametes, then selected life history traits such as long and synchronous periods of gametogenesis may confer vulnerability to genotoxic substances in chronic exposures. Recommendations for future research include strategic development of animal models that can be used to elucidate multiple mechanisms of effect (multiend point) at varying levels of biological organization (multilevel). RP ANDERSON, SL (reprint author), UNIV CALIF BERKELEY,LAWRENCE BERKELEY LAB,1 CYLOTRON RD,BERKELEY,CA 94720, USA. FU NIEHS NIH HHS [P42 ES04705-03] NR 27 TC 84 Z9 84 U1 0 U2 17 PU NATL INST ENVIRON HEALTH SCI PI RES TRIANGLE PK PA PO BOX 12233, RES TRIANGLE PK, NC 27709 SN 0091-6765 J9 ENVIRON HEALTH PERSP JI Environ. Health Perspect. PD DEC PY 1994 VL 102 SU 12 BP 9 EP 12 PG 4 WC Environmental Sciences; Public, Environmental & Occupational Health; Toxicology SC Environmental Sciences & Ecology; Public, Environmental & Occupational Health; Toxicology GA QE659 UT WOS:A1994QE65900002 PM 7713042 ER PT J AU SHUGART, L THEODORAKIS, C AF SHUGART, L THEODORAKIS, C TI ENVIRONMENTAL GENOTOXICITY - PROBING THE UNDERLYING MECHANISMS SO ENVIRONMENTAL HEALTH PERSPECTIVES LA English DT Article; Proceedings Paper CT Napa Conference on Genetic and Molecular Ecotoxicology CY OCT 12-15, 1993 CL YOUNTVILLE, CA DE ENVIRONMENTAL POLLUTION; DNA ADDUCTS; DNA STRAND BREAKS; DNA MARKERS; GENOTOXICITY ID DNA-DAMAGE; CONTAMINATION; DOSIMETRY AB Environmental pollution is a complex issue because of the diversity of anthropogenic agents, both chemical and physical, that have been detected and catalogued. The consequences to biota from exposure to genotoxic agents present an additional problem because of the potential for these agents to produce adverse change at the cellular and organismal levels. Past studies in genetic toxicology at the Oak Ridge National Laboratory have focused on structural damage to the DNA of environmental species that may occur after exposure to genotoxic agents and the use of this information to document exposure and to monitor remediation. In an effort to predict effects at the population, community, and ecosystem levels, current studies in genetic ecotoxicology are attempting to characterize the biologic mechanisms at the gene level that regulate and limit the response of an individual organism to genotoxic factors in their environment. RP SHUGART, L (reprint author), OAK RIDGE NATL LAB,DIV ENVIRONM SCI,POB 2008,OAK RIDGE,TN 37831, USA. NR 20 TC 38 Z9 41 U1 1 U2 3 PU NATL INST ENVIRON HEALTH SCI PI RES TRIANGLE PK PA PO BOX 12233, RES TRIANGLE PK, NC 27709 SN 0091-6765 J9 ENVIRON HEALTH PERSP JI Environ. Health Perspect. PD DEC PY 1994 VL 102 SU 12 BP 13 EP 17 PG 5 WC Environmental Sciences; Public, Environmental & Occupational Health; Toxicology SC Environmental Sciences & Ecology; Public, Environmental & Occupational Health; Toxicology GA QE659 UT WOS:A1994QE65900003 PM 7713026 ER PT J AU EVERAARTS, JM SLEIDERINK, HM DENBESTEN, PJ HALBROOK, RS SHUGART, LR AF EVERAARTS, JM SLEIDERINK, HM DENBESTEN, PJ HALBROOK, RS SHUGART, LR TI MOLECULAR RESPONSES AS INDICATORS OF MARINE POLLUTION - DNA-DAMAGE AND ENZYME-INDUCTION IN LIMANDA-LIMANDA AND ASTERIAS-RUBENS SO ENVIRONMENTAL HEALTH PERSPECTIVES LA English DT Article; Proceedings Paper CT Napa Conference on Genetic and Molecular Ecotoxicology CY OCT 12-15, 1993 CL YOUNTVILLE, CA DE MOLECULAR RESPONSE; BIOMARKERS; DAB; SEASTAR; DNA STRAND BREAKS; CYTOCHROME P450; EROD ACTIVITY; BPH ACTIVITY; MARINE POLLUTION ID POLYCHLORINATED-BIPHENYLS; MONOOXYGENASE SYSTEM; METABOLISM; INVERTEBRATES; ASSAY AB During a survey from 26 August through 13 September 1991, specimens of the flatfish, Limanda limanda (dab), and the asteroid echinoderm, Asterias rubens (seastar), were collected at sampling locations along transects radiating into the North Sea from the coastal zone of The Netherlands. In homogenates of liver tissue from male dab and the digestive gland (pyloric caeca) of female seastar, DNA damage (strand breaks) and induction of the cytochrome P450-dependent monooxygenase system (MO) were determined. Areas could be described with significantly increased percentages of strand breaks (lower integrity) both in dab and seastar. However, enhanced DNA strand breaks did not correspond with contamination gradients, expressed as concentrations of polychlorinated biphenyls (PCBs) or polyaromatic hydrocarbons. MO enzyme induction in the hepatic 13,000g fraction of male dab, measured as 7-ethoxyresorulin-O-deethylase activity, was significantly enhanced in response to low ambient temperatures. Some evidence was found for the facilitation of benzo[a]pyrene hydroxylase activity expressing the enzyme induction in the microsomal fraction of pyloric caeca of seastars, at increasing PCB concentrations. DNA integrity and enzyme induction elucidate the physiologic status and might be indicative for ambient impairment within restricted areas, and not necessarily related to the presence of anthropogenic or xenobiotic substances. C1 UNIV UTRECHT,TOXICOL RES INST,3508 TD UTRECHT,NETHERLANDS. SO ILLINOIS UNIV,COOPERAT WILDLIFE RES LAB,CARBONDALE,IL 62901. OAK RIDGE NATL LAB,OAK RIDGE,TN. RP EVERAARTS, JM (reprint author), NETHERLANDS INST SEA RES,POB 59,1790 AB DENBERG TEXEL,NETHERLANDS. NR 27 TC 23 Z9 25 U1 1 U2 3 PU NATL INST ENVIRON HEALTH SCI PI RES TRIANGLE PK PA PO BOX 12233, RES TRIANGLE PK, NC 27709 SN 0091-6765 J9 ENVIRON HEALTH PERSP JI Environ. Health Perspect. PD DEC PY 1994 VL 102 SU 12 BP 37 EP 43 PG 7 WC Environmental Sciences; Public, Environmental & Occupational Health; Toxicology SC Environmental Sciences & Ecology; Public, Environmental & Occupational Health; Toxicology GA QE659 UT WOS:A1994QE65900008 PM 7713032 ER PT J AU SPEAR, RC BOIS, FY AF SPEAR, RC BOIS, FY TI PARAMETER VARIABILITY AND THE INTERPRETATION OF PHYSIOLOGICALLY-BASED PHARMACOKINETIC MODELING RESULTS SO ENVIRONMENTAL HEALTH PERSPECTIVES LA English DT Article; Proceedings Paper CT Workshop on Pharmacokinetics - Defining the Dose for Risk Assessment CY MAR 04-05, 1992 CL WASHINGTON, DC SP NATL RES COUNCIL, BOARD ENVIRONM STUDIES & TOXICOL, COMM TOXICOL DE MODELING; BENZENE DISTRIBUTION; BENZENE METABOLISM; RATS; HUMAN ID BENZENE PHARMACOKINETICS; METABOLISM; DISPOSITION; RATS; MICE; INHALATION; SIMULATION AB For the past several years we have been working with models of benzene distribution and metabolism principally in the rat, but more recently in humans. Our biologically related objectives have been primarily to assist our laboratory-based colleagues in their quest for understanding of the mechanisms by which benzene exerts its toxic action. A secondary goal has been to develop or adapt models useful in risk assessment applications. We have also had methodological goals that relate to applications oi sensitivity analysis on the one hand, but more fundamentally to the connection between experimental data and model structure and parameterization. This paper presents an overview of our work in these areas C1 UNIV CALIF BERKELEY,LAWRENCE BERKELEY LAB,BERKELEY,CA 94720. RP SPEAR, RC (reprint author), UNIV CALIF BERKELEY,SCH PUBL HLTH,BERKELEY,CA 94720, USA. RI Bois, Frederic/E-9241-2012 OI Bois, Frederic/0000-0002-4154-0391 FU NIEHS NIH HHS [P42 ES04705] NR 11 TC 22 Z9 22 U1 1 U2 2 PU NATL INST ENVIRON HEALTH SCI PI RES TRIANGLE PK PA PO BOX 12233, RES TRIANGLE PK, NC 27709 SN 0091-6765 J9 ENVIRON HEALTH PERSP JI Environ. Health Perspect. PD DEC PY 1994 VL 102 SU 11 BP 61 EP 66 PG 6 WC Environmental Sciences; Public, Environmental & Occupational Health; Toxicology SC Environmental Sciences & Ecology; Public, Environmental & Occupational Health; Toxicology GA QH893 UT WOS:A1994QH89300008 PM 7737043 ER PT J AU BRYCE, AL KORNICKER, WA ELZERMAN, AW CLARK, SB AF BRYCE, AL KORNICKER, WA ELZERMAN, AW CLARK, SB TI NICKEL ADSORPTION TO HYDROUS FERRIC-OXIDE IN THE PRESENCE OF EDTA - EFFECTS OF COMPONENT ADDITION SEQUENCE SO ENVIRONMENTAL SCIENCE & TECHNOLOGY LA English DT Article ID AMORPHOUS ALUMINUM HYDROXIDE; METAL-COMPLEX FORMATION; REACTION-KINETICS; CHELATING-AGENTS; SURFACE; GOETHITE; CADMIUM; LIGANDS; ACIDS; DESORPTION AB Nickel, EDTA, and hydrous ferric oxide were combined in different sequences to study the effect on equilibration. In this system, the fraction of nickel adsorbed to the hydrous ferric oxide depended on the component addition sequence, but the fraction of EDTA adsorbed did not. In one sequence, nickel and EDTA were combined to preform a NiEDTA2- complex. The complex had adsorption characteristics similar to EDTA with high adsorption at pH <7 and suppressed adsorption at pH > 7. Equilibrium adsorption of the complex could be modeled using the diffuse layer model. When nickel or EDTA was individually equilibrated with HFO prior to the addition of EDTA or nickel, respectively, the system did not attain equilibrium. Rapid EDTA adsorption at pH <7 prevented the formation of the ternary Ni-EDTA surface complex. At pH >7, nickel adsorption was faster than the formation of the NiEDTA2- complex, but once adsorbed, nickel was slowly desorbed through the formation of solution NiEDTA2-. C1 CLEMSON UNIV,LG RICH ENVIRONM RES LAB,CLEMSON,SC 29634. RP BRYCE, AL (reprint author), UNIV GEORGIA,SAVANNAH RIVER ECOL LAB,PO DRAWER E,AIKEN,SC 29802, USA. NR 40 TC 62 Z9 63 U1 0 U2 8 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 DEC PY 1994 VL 28 IS 13 BP 2353 EP 2359 DI 10.1021/es00062a020 PG 7 WC Engineering, Environmental; Environmental Sciences SC Engineering; Environmental Sciences & Ecology GA PV171 UT WOS:A1994PV17100023 PM 22176054 ER PT J AU GOVINDARAJU, RS SHRESTHA, PL ORLOB, GT AF GOVINDARAJU, RS SHRESTHA, PL ORLOB, GT TI COMPARISON OF SINGLE MECHANISM AND MULTI MECHANISM-BASED APPROACHES FOR KINETICS OF SEDIMENT REMOVAL SO ENVIRONMENTAL TECHNOLOGY LA English DT Article DE AGGREGATION; KINETICS; COHESIVE SEDIMENTS; SEDIMENTATION; COLLISION MECHANISMS ID PHYSICAL CHARACTERISTICS; COAGULATION; FLOCS AB The process of cohesive particle sedimentation in aquatic environments is perceived as one of continuous formation of aggregates by coagulation and their separation from the water column by accumulation on the deposition bed. Over the temporal scales of practical interest for natural systems, many physical, chemical, and environmental factors govern the rate of sedimentation, hence a purely physics-based description has not yet been developed. A new information-based model that uses experimental information to derive governing parameters, while predicting removal through power law relationships, is proposed and tested. Analytical solutions derived for this model are shown to be applicable over large ranges of concentrations and to various fluid-sediment environments. Comparisons with numerically derived and observed data show that the analytical model is a versatile tool that improves fundamental understanding of the physical processes involved in sedimentation. The inverse problem of identification and quantification of model parameter values from experimental results is discussed. Predictions based on average sediment kinetics are found to be in reasonable agreement with experimental observations in a variety of special cases examined. C1 LAWRENCE LIVERMORE NATL LAB,DEPT CIVIL & ENVIRONM ENGN,DAVIS,CA 95616. VIRGINIA TECH, DEPT CIVIL ENGN,BLACKSBURG,VA. RP GOVINDARAJU, RS (reprint author), KANSAS STATE UNIV AGR & APPL SCI,DEPT CIVIL ENGN,MANHATTAN,KS 66506, USA. OI Govindaraju, Rao/0000-0003-3957-3319 NR 19 TC 2 Z9 2 U1 0 U2 0 PU SELPER LTD, PUBLICATIONS DIV PI LONDON PA 79 RUSTHALL AVENUE, LONDON, ENGLAND W4 1BN SN 0959-3330 J9 ENVIRON TECHNOL JI Environ. Technol. PD DEC PY 1994 VL 15 IS 12 BP 1101 EP 1120 PG 20 WC Environmental Sciences SC Environmental Sciences & Ecology GA PW388 UT WOS:A1994PW38800001 ER PT J AU JASSBY, AD POWELL, TM AF JASSBY, AD POWELL, TM TI HYDRODYNAMIC INFLUENCES ON INTERANNUAL CHLOROPHYLL VARIABILITY IN AN ESTUARY - UPPER SAN-FRANCISCO BAY DELTA (CALIFORNIA, USA) SO ESTUARINE COASTAL AND SHELF SCIENCE LA English DT Article DE CHLOROPHYLL DISTRIBUTION; RIVER FLOW; STATISTICAL MODELS; TURBIDITY MAXIMUM; ESTUARIES; ALGAL BLOOMS; PHYTOPLANKTON; SAN FRANCISCO BAY ID COASTAL-PLAIN ESTUARIES; DUTCH WADDEN SEA; PHYTOPLANKTON PRODUCTIVITY; PRINCIPAL COMPONENTS; TEMPORAL DYNAMICS; DELAWARE ESTUARY; FLUCTUATIONS; BIOMASS; LIGHT; ALGORITHMS AB Diversion of estuarine water for human use, in conjunction with river inflow, is the main underlying cause of interannual chlorophyll variability in the landward portion of the San Francisco Bay-Delta estuary, i.e. Suisun Bay and the Sacramento-San Joaquin Delta, The principal feature of year-to-year change is high chlorophyll variability within the specific conductance range of 2-10 mS cm(-1) (salinity 1-6), the approximate boundaries of an estuarine turbidity maximum (ETM). This variability stems from two separate hydrodynamic forces: (1) the strength of flow into the ETM, which affects primary productivity, losses to benthic macroinvertebrates, washout of phytoplankton cells, and chlorophyll loading; and (2) export of water from the estuary for human use, which independently affects the loading of chlorophyll from upstream sources into the ETM. In addition to the evidence for (1) presented in previous, largely descriptive studies, the simultaneous existence of both pathways is supported here by statistical models and material budgets. The source of phytoplankton organic matter from upstream was investigated further. Estimates were made for primary productivity levels in the Delta. These estimates are consistent with a mass balance for chlorophyll that suggests the Delta usually augments the flow of phytoplankton biomass from the rivers. If water were diverted from upstream of the Delta, rather than from within the Delta, the mass balance implies that both chlorophyll outflow from the Delta into the Bay, as well as primary productivity within the Delta, would increase. The primary productivity estimates also indicate that, on average, most of the phytoplankton emerging from the Delta is actually produced within the Delta, nor upstream in the rivers; furthermore, most of the Delta primary productivity is respired or consumed within the Delta. A second, smaller mode of variability is as a result of phytoplankton blooms in the San Joaquin River, which were quite large and variable prior to 1978 but have been relatively small since that time. The underlying processes have not been identified in detail, but are suspected to be hydrodynamic in nature. RP JASSBY, AD (reprint author), LAWRENCE LIVERMORE NATL LAB,DIV ENVIRONM STUDIES,DAVIS,CA 95616, USA. NR 54 TC 18 Z9 18 U1 0 U2 5 PU ACADEMIC PRESS LTD PI LONDON PA 24-28 OVAL RD, LONDON, ENGLAND NW1 7DX SN 0272-7714 J9 ESTUAR COAST SHELF S JI Estuar. Coast. Shelf Sci. PD DEC PY 1994 VL 39 IS 6 BP 595 EP 618 DI 10.1016/S0272-7714(06)80012-0 PG 24 WC Marine & Freshwater Biology; Oceanography SC Marine & Freshwater Biology; Oceanography GA PW391 UT WOS:A1994PW39100005 ER PT J AU EDMAN, CF GEORGE, SE MEANS, AR SCHULMAN, H YASWEN, P AF EDMAN, CF GEORGE, SE MEANS, AR SCHULMAN, H YASWEN, P TI SELECTIVE ACTIVATION AND INHIBITION OF CALMODULIN-DEPENDENT ENZYMES BY A CALMODULIN-LIKE PROTEIN FOUND IN HUMAN EPITHELIAL-CELLS SO EUROPEAN JOURNAL OF BIOCHEMISTRY LA English DT Article ID TARGET ENZYMES; ALPHA-HELICES; KINASE; EXPRESSION; CALCIUM; BINDING; PEPTIDE; DOMAIN; GENE; MUTAGENESIS AB A calmodulin-like protein, which is identical in size and 85% identical to vertebrate calmodulin, was recently identified by 'subtractive hybridization' comparison of transcripts expressed in normal versus transformed human mammary epithelial cells. Unlike the ubiquitous distribution of calmodulin, calmodulin-like protein expression is restricted to certain epithelial cells, and appears to be modulated during differentiation. In addition, calmodulin-like protein levels are often significantly reduced in malignant tumor cells as compared to corresponding normal epithelial cells. The current studies compare calmodulin-like protein functions with those of calmodulin. We find that calmodulin-like protein activation of multifunctional Ca2+/calmodulin-dependent protein kinase II (calmodulin kinase II) is equivalent to activation by calmodulin, but that four other calmodulin-dependent enzymes, cGMP phosphodiesterase, calcineurin, nitric-oxide synthase, and myosin-light-chain kinase, display much weaker activation by calmodulin-like protein than by calmodulin. In the case of myosin-light-chain kinase, calmodulin-like protein competitively inhibits calmodulin activation of the enzyme with a K-i value of 170 nM. Thus, calmodulin-like protein may have evolved to function as a specific agonist of certain calmodulin-dependent enzymes, and/or as a specific competitive antagonist of other calmodulin-dependent enzymes. C1 UNIV CALIF BERKELEY,LAWRENCE BERKELEY LAB,DIV LIFE SCI,BERKELEY,CA 94720. DUKE UNIV,MED CTR,DEPT CARDIOL,DURHAM,NC. DUKE UNIV,MED CTR,DEPT PHARMACOL,DURHAM,NC. STANFORD UNIV,SCH MED,DEPT NEUROBIOL,STANFORD,CA. FU NCI NIH HHS [R01-CA-54247]; NHLBI NIH HHS [HL-48662]; NIGMS NIH HHS [GM-33976] NR 34 TC 17 Z9 17 U1 0 U2 1 PU SPRINGER VERLAG PI NEW YORK PA 175 FIFTH AVE, NEW YORK, NY 10010 SN 0014-2956 J9 EUR J BIOCHEM JI Eur. J. Biochem. PD DEC 1 PY 1994 VL 226 IS 2 BP 725 EP 730 DI 10.1111/j.1432-1033.1994.tb20101.x PG 6 WC Biochemistry & Molecular Biology SC Biochemistry & Molecular Biology GA QH605 UT WOS:A1994QH60500053 PM 7528142 ER PT J AU MCPHERSON, DW LAMBERT, CR KNAPP, FF AF MCPHERSON, DW LAMBERT, CR KNAPP, FF TI IN-VIVO METABOLIC STUDIES OF THE TRANS-(R,R) ISOMER OF RADIOIODINATED IQNP - A NEW LIGAND WITH HIGH-AFFINITY FOR THE M(1) MUSCARINIC-CHOLINERGIC RECEPTOR SO EUROPEAN JOURNAL OF NUCLEAR MEDICINE LA English DT Article DE MUSCARINIC RECEPTOR LIGANDS; IQNP; IQNB; BRAIN; HEART; SINGLE-PHOTON EMISSION TOMOGRAPHY ID ALZHEIMERS-DISEASE; INVITRO AB E-(R,R)-IQNP is a new ligand analogue of IQNB, which has high affinity for the cholinergic-muscarinic receptor, Earlier studies have demonstrated high cerebral uptake of activity with selective localization in M(1) receptor subtype al eas of the brain. In this paper we describe the results of metabolic studies of E(R,R)-IQNP directed at determining the metabolic fate of this ligand and the identification of the radioactive species observed in the brain and heart tissue. Tissue Folch extracts demonstrated that the lipid-soluble extracts from brain contained 87.0% +/- 1.65% of the activity up to 24 h. In the heart, 61.9% +/- 7.50% of the activity was extracted in the lipid-soluble extract after 30 min, decreasing to 51.4% +/- 0.65% by 4 h, In contrast, data from other tissues studied demonstrated large amounts of either aqueous soluble activity or activity which was not extracted from the tissue pellet material; analysis of lipid organic extracts revealed the following results: liver (4 h), 7.43% +/- 0.96%; serum (4 h), 3.73% +/- 0.87%; urine (24 h), 9.4%; feces (24 h), 16.5%. Thin-layer chromatographic (TLC) and high-performance liquid chromatographic (HPLC) analyses of lipid-soluble brain extracts indicated that only unmetabolized E-(R,R)-IQNP was detected (99.4% +/- 1.25%). Activity which was extracted into the organic phase from heart tissue was also determined by TLC and HPLC analysis to contain large amounts of unmetabolized ligand after 4 h (88.5% +/- 0.57%). In addition, however, low levels of two additional radioactive components were detected which increased with time, TLC analysis of the plasma lipid extracts indicated only a small amount of unmetabolized E-(R,R)-IQNP, In comparison, the liver, feces, and urine lipid extracts contained only metabolites. These initial studies clearly indicate that radioactivity present in the brain after intravenous administration of radioiodinated E-(R,R)-IQNP represents only the unmetabolized ligand and that this new ligand shows promise for single-photon emission tomographic imaging of muscarinic receptors in humans. RP MCPHERSON, DW (reprint author), OAK RIDGE NATL LAB,DIV HLTH SCI RES,NUCL MED GRP,POB 2008,BLDG 4501,OAK RIDGE,TN 37831, USA. NR 13 TC 8 Z9 8 U1 0 U2 1 PU SPRINGER VERLAG PI NEW YORK PA 175 FIFTH AVE, NEW YORK, NY 10010 SN 0340-6997 J9 EUR J NUCL MED JI Eur. J. Nucl. Med. PD DEC PY 1994 VL 21 IS 12 BP 1293 EP 1297 DI 10.1007/BF02426692 PG 5 WC Radiology, Nuclear Medicine & Medical Imaging SC Radiology, Nuclear Medicine & Medical Imaging GA PW557 UT WOS:A1994PW55700005 PM 7875166 ER PT J AU MULVEY, M KELLER, GP MEFFE, GK AF MULVEY, M KELLER, GP MEFFE, GK TI SINGLE-LOCUS AND MULTIPLE-LOCUS GENOTYPES AND LIFE-HISTORY RESPONSES OF GAMBUSIA-HOLBROOKI REARED AT 2 TEMPERATURES SO EVOLUTION LA English DT Article DE ALLOZYMES; GAMBUSIA HOLBROOKI; HETEROZYGOSITY; LIFE HISTORY; POECILIIDAE; STRESS; TEMPERATURE ID DEVELOPMENTAL STABILITY; RAINBOW-TROUT; ENZYME-HETEROZYGOSITY; GROWTH-RATE; MICROPTERUS-SALMOIDES; BIOCHEMICAL GENETICS; POECILIA-LATIPINNA; ALLOZYME GENOTYPE; INORGANIC MERCURY; LARGEMOUTH BASS AB Eastern mosquitofish (Gambusia holbrooki) were reared from birth to 10 wk of age at 25 degrees C and 32 degrees C. Relationships of growth, time to maturity, and developmental stability to isozyme genotype were used to examine the hypothesis that more heterozygous individuals should exhibit superior performances, especially under thermally stressful (32 degrees C) conditions. More heterozygous fish grew faster than homozygous individuals, especially at 32 degrees C. Significant differences in time to maturity were detected among allozyme genotypes but not with heterozygosity. Multiple-locus heterozygosity was negatively related to fluctuating asymmetry. Thus, life-history traits were affected by both multiple-locus heterozygosity and single-locus genotype. RP MULVEY, M (reprint author), UNIV GEORGIA,SAVANNAH RIVER ECOL LAB,DRAWER E,AIKEN,SC 29802, USA. NR 50 TC 23 Z9 24 U1 1 U2 8 PU SOC STUDY EVOLUTION PI LAWRENCE PA 810 E 10TH STREET, LAWRENCE, KS 66044 SN 0014-3820 J9 EVOLUTION JI Evolution PD DEC PY 1994 VL 48 IS 6 BP 1810 EP 1819 DI 10.2307/2410510 PG 10 WC Ecology; Evolutionary Biology; Genetics & Heredity SC Environmental Sciences & Ecology; Evolutionary Biology; Genetics & Heredity GA RA377 UT WOS:A1994RA37700006 ER PT J AU Cedeno, W Vemuri, VR Slezak, T AF Cedeno, Walter Vemuri, V. Rao Slezak, Tom TI Multiniche Crowding in Genetic Algorithms and Its Application to the Assembly of DNA Restriction-Fragments SO EVOLUTIONARY COMPUTATION LA English DT Article DE Genetic algorithms; multimodal functions; DNA restriction-fragment assembly; human genome project AB The determination of the sequence of all nucleotide base-pairs in a DNA molecule, from restriction-fragment data, is a complex task and can be posed as the problem of finding the optima of a multimodal function. A genetic algorithm that uses multiniche crowding permits us to do this. Performance of this algorithm is first tested using a standard suite of test functions. The algorithm is next tested using two data sets obtained from the Human Genome Project at the Lawrence Livermore National Laboratory. The new method holds promise in automating the sequencing computations. C1 [Cedeno, Walter; Vemuri, V. Rao] Univ Calif Davis, Dept Appl Sci, Livermore, CA 94550 USA. [Slezak, Tom] Univ Calif Lawrence Livermore Natl Lab, Ctr Human Genome, Livermore, CA 94550 USA. RP Cedeno, W (reprint author), Univ Calif Davis, Dept Appl Sci, Livermore, CA 94550 USA. EM wcedeno@llnl.gov; vemur1@llnl.gov; slezak1@llnl.gov FU Office of Energy Research (U. S. Department of Energy) [W-7405-Eng-48]; Institute of Scientific Computing Research of the Lawrence Livermore National Laboratory FX The authors thank the three anonymous reviewers for their many valuable comments and Dr. Ken De Jong for encouraging us to make the revisions and for bringing to our attention some relevant unpublished work. This work was supported, in part, by the Applied Mathematics Program of the Office of Energy Research (U.S. Department of Energy) under contract number W-7405-Eng-48 to Lawrence Livermore National Laboratory and, in part, by a grant from the Institute of Scientific Computing Research of the Lawrence Livermore National Laboratory. NR 29 TC 8 Z9 8 U1 0 U2 4 PU MIT PRESS PI CAMBRIDGE PA 55 HAYWARD STREET, CAMBRIDGE, MA 02142 USA SN 1063-6560 J9 EVOL COMPUT JI Evol. Comput. PD WIN PY 1994 VL 2 IS 4 BP 321 EP 345 DI 10.1162/evco.1994.2.4.321 PG 25 WC Computer Science, Artificial Intelligence; Computer Science, Theory & Methods SC Computer Science GA V21YZ UT WOS:000208244200002 ER PT J AU KOSTIUK, LW CHENG, RK AF KOSTIUK, LW CHENG, RK TI IMAGING OF PREMIXED FLAMES IN MICROGRAVITY SO EXPERIMENTS IN FLUIDS LA English DT Article ID BEHAVIOR AB A laser schlieren system which uses video recording and digital images analysis has been developed and applied successfully to microgravity combustion experiments performed in a drop-tower. The optical system and the experiment are installed within a small package which is subjected to free-fall. The images are recorded on video tape and are digitized and analyzed by a computer-controlled image processor. The experimental results include laminar and turbulent premixed conical flames in microgravity, normal positive gravity (upward), and reverse gravity (downward). The procedures to extract frequency information from the digitized images are described. Many gross features of the effects of gravity on premixed conical flames are found. Flames that ignite easily in normal gravity fail to ignite in microgravity. Buoyancy driven instabilities associated with an interface formed between the hot products and the cold surrounding air is the mechanism through which gravity influences premixed laminar and turbulent flames. In normal gravity, this causes the flame to flicker. In reverse gravity, - g, and microgravity, mug, the interface is stable and flame flickering ceases. The flickering frequencies of + g flames vary with changing upstream boundary conditions. The absence of flame flickering in mug suggest that mug flames would be less sensitive to these changes. C1 LAWRENCE BERKELEY LAB,DIV ENERGY & ENVIRONM,COMBUST GRP,BERKELEY,CA 94720. NR 11 TC 15 Z9 16 U1 0 U2 0 PU SPRINGER VERLAG PI NEW YORK PA 175 FIFTH AVE, NEW YORK, NY 10010 SN 0723-4864 J9 EXP FLUIDS JI Exp. Fluids PD DEC PY 1994 VL 18 IS 1-2 BP 59 EP 68 PG 10 WC Engineering, Mechanical; Mechanics SC Engineering; Mechanics GA PX823 UT WOS:A1994PX82300007 ER PT J AU STAPP, HP AF STAPP, HP TI INTERPRETATIONS OF QUANTUM-MECHANICS, JOINT MEASUREMENT OF INCOMPATIBLE OBSERVABLES, AND COUNTERFACTUAL DEFINITENESS - COMMENTS SO FOUNDATIONS OF PHYSICS LA English DT Article AB Some seeming logical deficiencies in a recent paper are described. RP STAPP, HP (reprint author), UNIV CALIF BERKELEY,LAWRENCE BERKELEY LAB,CYCLOTRON RD,BERKELEY,CA 94720, USA. NR 3 TC 0 Z9 0 U1 1 U2 1 PU PLENUM PUBL CORP PI NEW YORK PA 233 SPRING ST, NEW YORK, NY 10013 SN 0015-9018 J9 FOUND PHYS JI Found. Phys. PD DEC PY 1994 VL 24 IS 12 BP 1665 EP 1669 DI 10.1007/BF02054788 PG 5 WC Physics, Multidisciplinary SC Physics GA QB564 UT WOS:A1994QB56400002 ER PT J AU ARUNASALAM, V AF ARUNASALAM, V TI ARE THE INVARIANCE-PRINCIPLES REALLY TRULY LORENTZ-COVARIANT SO FOUNDATIONS OF PHYSICS LETTERS LA English DT Article DE LORENTZ-COVARIANT SYMMETRY OPERATIONS; COVARIANCE PRINCIPLE; LORENTZ COVARIANCE OF INVARIANCE PRINCIPLES; WORLDSPACE SYMMETRY MAPPINGS; LORENTZ-COVARIANT MAPPINGS; LORENTZ NONCOVARIANCE OF PARITY AND TIME-REVERSAL INVARIANCE AB It is shown that some sections of the invariance (or symmetry) principles, such as the space reversal symmetry (or parity P) and time reversal symmetry T (of elementary particle and condensed matter physics, etc.), are not really truly Lorentx covariant and hence are dependent on the chosen inertial frame; while the world parity or the proper parity W (i.e., the spacetime reversal symmetry PT) is a truly Lorentz covariant concept, the same for all inertial observers. The basic reason for this is that in the Minkowskian space-time continuum frames of special relativity (in contrast to the space and time frames) one cannot change either space or time keeping the other one fixed and also maintain the causality requirements that all world space mappings should be timelike. Indeed, I find that the Dirac-Wigner and Lee-Yang, etc. sense of Lorentz invariance is not in full compliance with the Einstein-Minkowski requirements of the Lorentz covariance (in conjunction with the causality requirements) of all physical laws (i.e., the worldspace Mach principle). RP ARUNASALAM, V (reprint author), PRINCETON UNIV,PRINCETON PLASMA PHYS LAB,POB 451,PRINCETON,NJ 08543, USA. NR 0 TC 6 Z9 6 U1 0 U2 0 PU PLENUM PUBL CORP PI NEW YORK PA 233 SPRING ST, NEW YORK, NY 10013 SN 0894-9875 J9 FOUND PHYS LETT JI Found. Phys. Lett. PD DEC PY 1994 VL 7 IS 6 BP 515 EP 530 DI 10.1007/BF02219747 PG 16 WC Physics, Multidisciplinary SC Physics GA QA780 UT WOS:A1994QA78000002 ER PT J AU SAHIN, S MOIR, RW UNALAN, S AF SAHIN, S MOIR, RW UNALAN, S TI NEUTRONIC INVESTIGATION OF A POWER-PLANT USING PEACEFUL NUCLEAR EXPLOSIVES SO FUSION TECHNOLOGY LA English DT Article DE PEACEFUL NUCLEAR EXPLOSIVES; SHALLOW BURIAL; TRITIUM BREEDING ID FUSION-REACTORS AB A neutron physics analysis of the modified PACER concept was conducted to assess the required liquid zone thickness of which the volume fraction is 25% in the form of Li2BeF4 (Flibe) jets and 75% as void. These liquid jets surround a low-yield nuclear fusion explosive and protect the chamber walls. The neutronic calculations assumed a 30-m-radius underground spherical geometry cavity with a 1-cm-thick stainless steel liner attached to the excavated rock wall. Achievement of tritium breeding ratios of 1.05 and 1.15 requires a Flibe thickness of 1.6 and 2.0 m, respectively, which results in average energy densities of 24 900 and 19 085 J/g. Our calculations show that for a Flibe zone thickness >2.5 m, the activation of the steel linear and rock would be low enough after 30 yr of operation that the cavity would satisfy the U.S. Nuclear Regulatory Commission's rules for ''shallow burial'' upon decommissioning, assuming other sources of radioactivity could be removed or qualified as well. This means that upon decommissioning, the site could essentially be abandoned, or the cavity could be used as a shallow burial site for other qualified materials. C1 LAWRENCE LIVERMORE NATL LAB,LAWRENCE LIVERMORE NATL LAB,LIVERMORE,CA 94551. ERCIYES UNIV,FAK MUHENDISLIK,KAYSERI,TURKEY. RP SAHIN, S (reprint author), GAZI UNIV,TEKN EGITIM FAK BESEVLER,ANKARA,TURKEY. RI SAHIN, Sumer/C-6252-2013 OI SAHIN, Sumer/0000-0003-2844-8061 NR 23 TC 24 Z9 25 U1 0 U2 2 PU AMER NUCLEAR SOCIETY PI LA GRANGE PK PA 555 N KENSINGTON AVENUE, LA GRANGE PK, IL 60525 SN 0748-1896 J9 FUSION TECHNOL JI Fusion Technol. PD DEC PY 1994 VL 26 IS 4 BP 1311 EP 1325 PG 15 WC Nuclear Science & Technology SC Nuclear Science & Technology GA PV632 UT WOS:A1994PV63200009 ER PT J AU MASARIK, J REEDY, RC AF MASARIK, J REEDY, RC TI EFFECTS OF BULK COMPOSITION ON NUCLIDE PRODUCTION PROCESSES IN METEORITES SO GEOCHIMICA ET COSMOCHIMICA ACTA LA English DT Article ID PRODUCTION-RATES; CHEMICAL-COMPOSITION; COSMOGENIC NUCLIDES; IRON-METEORITES; RARE-GASES; SOLAR; METEOROIDS; DEPENDENCE; PARTICLES; PROTONS AB The bulk chemical composition of meteorites is a major factor influencing the production of cosmogenic nuclides. Numerical simulations using Monte Carlo particle production and transport codes were used to investigate particle fluxes, Ar-38 elemental production ratios, and Ne-21/Ne-22 ratios in meteorites with a wide range of compositions. The calculations show that enhanced fluxes of low-energy secondary particles in metal-rich phases explain certain experimentally observed differences in nuclide production in various meteorite classes. RP MASARIK, J (reprint author), LOS ALAMOS NATL LAB,ASTROPHYS & RADIAT MEASUREMENT GRP,MS D436,LOS ALAMOS,NM 87545, USA. OI Reedy, Robert/0000-0002-2189-1303 NR 49 TC 134 Z9 134 U1 0 U2 9 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD, ENGLAND OX5 1GB SN 0016-7037 J9 GEOCHIM COSMOCHIM AC JI Geochim. Cosmochim. Acta PD DEC PY 1994 VL 58 IS 23 BP 5307 EP 5317 DI 10.1016/0016-7037(94)90314-X PG 11 WC Geochemistry & Geophysics SC Geochemistry & Geophysics GA PX170 UT WOS:A1994PX17000019 ER PT J AU FOURNIER, RO KENNEDY, BM AOKI, M THOMPSON, JM AF FOURNIER, RO KENNEDY, BM AOKI, M THOMPSON, JM TI CORRELATION OF GOLD IN SILICEOUS SINTERS WITH HE-3/HE-4 IN HOT-SPRING WATERS OF YELLOWSTONE-NATIONAL-PARK SO GEOCHIMICA ET COSMOCHIMICA ACTA LA English DT Article ID HELIUM-ISOTOPES; GEYSER BASIN; TRANSPORT; GEOCHEMISTRY; 25-DEGREES-C; DEPOSITION; EVOLUTION; CHEMISTRY; COMPLEXES; SYSTEMS AB Opaline sinter samples collected at Yellowstone National Park (YNP) were analyzed for gold by neutron activation and for other trace elements by the inductively coupled plasma optical emission spectroscopy (ICP-OES) method. No correlation was found between Au and As, Sb, or total Fe in the sinters, although the sample containing the highest Au also contains the highest Sb. There also was no correlation of Au in the sinter with the H2S concentration in the discharged hot spring water or with the estimated temperature of last equilibration of the water with the surrounding rock. The Au in rhyolitic tuffs and lavas at YNP found within the Yellowstone caldera show the same range in Au as do those outside the caldera, while thermal waters from within this caldera all have been found to contain relatively low dissolved Au and to deposit sinters that contain relatively little Au. Therefore, it is not likely that variations in Au concentrations among these sinters simply reflect differences in leachable Au in the rocks through which the hydrothermal fluids have passed. Rather, variations in [H2S], the concentration of total dissolved sulfide, that result from different physical and chemical processes that occur in different parts of the hydrothermal system appear to exert the main control on the abundance of Au in these sinters. Hydrothermal fluids at YNP convect upward through a series of successively shallower and cooler reservoirs where water-rock chemical and isotopic reactions occur in response to changing temperature and pressure. In some parts of the system the fluids undergo decompressional boiling, and in other parts they cool conductively without boiling. Mixing of ascending water from deep in the system with shallow groundwaters is common. All three processes generally result in a decrease in [H2S] and destabilize dissolved gold bisulfide complexes in reservoir waters in the YNP system. Thus, different reservoirs in rocks of similar composition and at similar temperatures may contain waters with different [H2S] and [AU]. The [H2S] in a subsurface reservoir water is difficult to assess on the basis of analyses of hot spring waters because of uncertainties about steam loss during fluid ascent. However, the same processes that result in low [H2S] in reservoir waters also tend to result in decreases in the ratio of He-3/He-4(R) dissolved in that water. Values of R relative to this ratio in air (Ra) attain values >15 in YNP thermal waters. To date, all of the thermal waters at YNP that have R/Ra values <9 have been found to deposit sinters with relatively low gold concentrations. These include all of the thermal waters that discharge from 180-215 degrees C reservoirs at Upper, Midway, and Lower Geyser Basins within the western part of the Yellowstone caldera. and thermal waters at Norris Geyser Basin, outside the Yellowstone caldera, where some of the waters flow directly to the surface from a reservoir where the temperature is about 300 degrees C. A high He-3/He-4 ratio in thermal water discharged at the surface does not guarantee high gold concentrations in the sinter deposited by this water. Boiling with loss of steam (the gas phase takes a separate route to the surface) during rapid upflow from the shallowest reservoir to the surface decreases the [H2S] and total He dissolved in the residual liquid without appreciably changing the He-3/He-4 ratio. This is because the isotopic composition of the He of the initial bulk fluid is unchanged and there is too little time for much radiogenic He-4 to build back into the liquid during this rapid ascent from the near-surface reservoir. However, if boiling with phase separation and loss of steam occurs deep in the system, the He-3/He-4 ratio in the residual liquid. now depleted in H2S and total He, will be susceptible to dilution with radiogenic He-4 that is acquired during the longer residence time underground. Some or all of the Au that comes out of solution when an initial gold bisulfide complex breaks down as a result of loss of H2S may be swept up to the surface as solid (probably colloidal) particles, depending on the rate of flow of the mixture of water and steam, and the geometry of the channel. Where colloidal silica also forms as a result of this boiling, free Au apparently becomes attached to the colloidal silica and deposits where the silica deposits. C1 UNIV CALIF BERKELEY,LAWRENCE BERKELEY LAB,DIV EARTH SCI,BERKELEY,CA 94720. GEOL SURVEY JAPAN,TSUKUBA,IBARAKI 305,JAPAN. RP FOURNIER, RO (reprint author), US GEOL SURVEY,MS-910,345 MIDDLEFIELD RD,MENLO PK,CA 94025, USA. NR 57 TC 10 Z9 10 U1 0 U2 4 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 DEC PY 1994 VL 58 IS 24 BP 5401 EP 5419 DI 10.1016/0016-7037(94)90238-0 PG 19 WC Geochemistry & Geophysics SC Geochemistry & Geophysics GA PY693 UT WOS:A1994PY69300003 ER PT J AU MACHESKY, ML PALMER, DA WESOLOWSKI, DJ AF MACHESKY, ML PALMER, DA WESOLOWSKI, DJ TI HYDROGEN-ION ADSORPTION AT THE RUTILE-WATER INTERFACE TO 250-DEGREES-C SO GEOCHIMICA ET COSMOCHIMICA ACTA LA English DT Letter ID ELECTROLYTE INTERFACE; DOUBLE-LAYER; OXIDES; SODIUM; CHARGE; TEMPERATURES; MEDIA AB A stirred hydrogen-electrode concentration cell was used to follow hydrogen ion adsorption by the rutile surface in NaCl media (0.01-1.0 m) between 25 and 250 degrees C. The pH of zero net surface charge (pHzpc) decreases to 200 degrees C and then appears to increase. Away from the pHzpc, negative surface charge is screened more efficiently by Na+ ions than positive charge is by Cl- ions and this effect increases with temperature. Thus, Na+ moves closer to the rutile surface with increasing temperature relative to Cl-. Finally, [pHzpc - 1/2pK(w)] is approximately constant (-1.1 +/- 0.2) for this rutile sample to 250 degrees C and is also equivalent to the equilibrium constant for an isocoulombic form of the ''1pKa'' surface ionization model. Thus, the constancy of [pHzpc - 1/2pK(w)] may also be useful for extrapolating rutile pHzpc values to higher temperatures and pressures than those studied here, and may also apply to many other oxide surfaces as well. C1 OAK RIDGE NATL LAB,DIV CHEM & ANALYT SCI,OAK RIDGE,TN 37831. RP MACHESKY, ML (reprint author), ILLINOIS STATE WATER SURVEY,2204 GRIFFITH DR,CHAMPAIGN,IL 61820, USA. NR 36 TC 43 Z9 43 U1 2 U2 6 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 DEC PY 1994 VL 58 IS 24 BP 5627 EP 5632 DI 10.1016/0016-7037(94)90254-2 PG 6 WC Geochemistry & Geophysics SC Geochemistry & Geophysics GA PY693 UT WOS:A1994PY69300019 ER PT J AU CHIARELLO, RP STURCHIO, NC AF CHIARELLO, RP STURCHIO, NC TI EPITAXIAL-GROWTH OF OTAVITE ON CALCITE OBSERVED IN-SITU BY SYNCHROTRON X-RAY-SCATTERING SO GEOCHIMICA ET COSMOCHIMICA ACTA LA English DT Letter ID REFLECTIVITY; INTERFACE; SURFACE AB Synchrotron X-ray reflectivity and X-ray diffraction techniques were used to characterize an otavite (CdCO3) overgrowth during its precipitation from an aqueous solution onto a calcite (1O $$($) over bar 14) cleavage surface. X-ray reflectivity was used to measure the otavite thickness and the roughness of the calcite/otavite and otavite/fluid interfaces. Specular and off-specular X-ray diffraction were used to measure the crystallographic orientation and long-range atomic order of the otavite overgrowth. The otavite grew coherently with a (10 $$($) over bar 14) growth plane oriented parallel to the calcite (10 $$($) over bar 14) cleavage surface. The average growth rate of the otavite for the first 9 hours was 15 Angstrom.h(-1). During the early growth stage (less than or equal to 50 Angstrom), the otavite (10 $$($) over bar 14) lattice spacing (d-value) was compressed by as much 2.2% in the direction perpendicular to the calcite cleavage surface. As the otavite thickness increased, this d-value approached that of bulk otavite. At a thickness of 443 Angstrom, the otavite was determined to be of single-crystal quality (0.4 degrees mosaic) and epitaxial with calcite. This study demonstrates a new and accurate approach for measuring in situ precipitation rates and growth mechanisms in mineral-fluid systems. RP CHIARELLO, RP (reprint author), ARGONNE NATL LAB,GEOSCI CMT-205,ARGONNE,IL 60439, USA. NR 14 TC 24 Z9 24 U1 0 U2 5 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 DEC PY 1994 VL 58 IS 24 BP 5633 EP 5638 DI 10.1016/0016-7037(94)90255-0 PG 6 WC Geochemistry & Geophysics SC Geochemistry & Geophysics GA PY693 UT WOS:A1994PY69300020 ER PT J AU REEDER, RJ LAMBLE, GM LEE, JF STAUDT, WJ AF REEDER, RJ LAMBLE, GM LEE, JF STAUDT, WJ TI MECHANISM OF SEO42- SUBSTITUTION IN CALCITE - AN XAFS STUDY SO GEOCHIMICA ET COSMOCHIMICA ACTA LA English DT Letter ID X-RAY-ABSORPTION; FINE-STRUCTURE; SELENITE; ADSORPTION AB Analysis of Se K-edge XAFS spectra of calcite grown from SeO42--bearing aqueous solutions at 25 degrees C reveals the local environment of Se incorporated in calcite. The position of the Se K-edge is consistent with oxidation state 6+, and the first shell contains four O atoms at a distance of 1.63 Angstrom, confirming that Se is present as the tetrahedral SeO42- complex ion. The second shell is split and is best fitted by approximately 2 Ca atoms at 3.17 Angstrom and approximately 4 Ca atoms at 3.49 Angstrom. The coordination indicated by the split second shell is consistent with substitution of the SeO42- ion in the CO3 site of the calcite, which has six nearest-neighbor Ca atoms. The large size of the SeO42- ion and its tetrahedral geometry cause significant distortion of the site that is consistent with the observed Se-Ca distances. Two possible models for the local coordination of the SeO42- ion are suggested that involve corner sharing of the SeO4 tetrahedron with neighboring Ca octahedra. The results suggest that other complex anions-particularly the geochemically important SO42- ion, which is also tetrahedral but slightly smaller than SeO42--may also substitute in the CO3 site of carbonates. C1 BROOKHAVEN NATL LAB,UPTON,NY 11973. SYNCHROTRON RADIAT RES CTR,HSINCHU 30077,TAIWAN. RP REEDER, RJ (reprint author), SUNY STONY BROOK,DEPT EARTH & SPACE SCI,STONY BROOK,NY 11794, USA. NR 26 TC 35 Z9 36 U1 0 U2 13 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 DEC PY 1994 VL 58 IS 24 BP 5639 EP 5646 DI 10.1016/0016-7037(94)90256-9 PG 8 WC Geochemistry & Geophysics SC Geochemistry & Geophysics GA PY693 UT WOS:A1994PY69300021 ER PT J AU BALDRIDGE, WS FERGUSON, JF BRAILE, LW WANG, B ECKHARDT, K EVANS, D SCHULTZ, C GILPIN, B JIRACEK, GR BIEHLER, S AF BALDRIDGE, WS FERGUSON, JF BRAILE, LW WANG, B ECKHARDT, K EVANS, D SCHULTZ, C GILPIN, B JIRACEK, GR BIEHLER, S TI THE WESTERN MARGIN OF THE RIO-GRANDE RIFT IN NORTHERN NEW-MEXICO - AN ABORTED BOUNDARY SO GEOLOGICAL SOCIETY OF AMERICA BULLETIN LA English DT Article ID TECTONIC DEVELOPMENT; CONTINENTAL RIFTS; ESPANOLA BASIN; EVOLUTION; DENSITY; MODEL AB The northwestern margin of the Espanola basin, part of the Rio Grande rift in northern New Mexico, is characterized by a zone >17 km wide of oblique-slip faults that off-set upper Paleozoic and Mesozoic strata of the eastern Colorado Plateau from Eocene and younger sedimentary rocks of the rift. Along this margin, a reasonably complete section of pre- and synrift Tertiary sediments is exposed. Combined interpretations of seismic reflection, seismic refraction, gravity, and geologic data acquired along a profile perpendicular to this boundary define the geometry of faulting, possible rotation of sedimentary units, and stratigraphy of rift fill. Vertical separation on the westernmost major fault, assumed to be the bounding fault between the rift and the Colorado Plateau, is <500 m; separation on other faults in the zone is <200 m. Thus the northwestern part of the Espanola basin (''Abiquiu embayment'') is a shallow platform rather than a deep rift basin. The embayment is separated from the main Espanola basin by the east-northeast-striking Embudo transfer fault, which appears to act as the northern bounding fault of the main basin. Although Tertiary units are progressively faulted downward toward the axis of the rift, depth to inferred Precambrian crystalline rocks becomes shallower and the stratigraphic thickness of the intervening Paleozoic and Mesozoic units decreases toward the axis. We interpret pinching out of these units toward the east as erosional thinning on the western flanks of the Laramide-age Sangre de Cristo/Brazos geanticline, which underlay much of the present rift basin. Imprecise age constraints suggest that faulting of the rift margin began 10-7 Ma, but was not active after 7 Ma. Extension was apparently transferred to the Embudo fault zone, which remained active until at least 2.5 Ma and possibly into Quaternary time. The Embudo transfer zone effectively decoupled the Abiquiu embayment from the main Espanola basin. Thus the boundary at Abiquiu preserves an early stage in the formation of the rift boundary. The shift in activity may have resulted from a change in regional stress field, or from increasing magnitude of strain, or both. The change in locus of extension reflects a narrowing of rift basins through time and an integration of main bounding structures between adjacent basins. Although we are uncertain whether the Abiquiu region, which uniquely preserves an early stage of deformation, is representative of other areas of continental extension, our results indicate that the initial formation of rift basins may occur as high-angle, planar normal faults distributed over a broad zone. No evidence from seismic data or from rotation of beds exists to indicate that faults become listric with depth, which is compatible with the small amount of extension (3.5%) inferred at this boundary. C1 UNIV TEXAS,GEOSCI PROGRAM,RICHARDSON,TX 75080. PURDUE UNIV,DEPT EARTH & ATMOSPHER SCI,W LAFAYETTE,IN 47907. UNIV CALIF SANTA CRUZ,EARTH SCI BOARD STUDIES,SANTA CRUZ,CA 95064. CALTECH,DIV GEOL & PLANETARY SCI,PASADENA,CA 91125. MIT,EARTH RESOURCES LAB,CAMBRIDGE,MA 02142. GOLDEN WEST COLL,DEPT PHYS,HUNTINGTON BEACH,CA 92647. SAN DIEGO STATE UNIV,DEPT GEOL SCI,SAN DIEGO,CA 92182. UNIV CALIF RIVERSIDE,DEPT EARTH SCI,RIVERSIDE,CA 92521. RP BALDRIDGE, WS (reprint author), LOS ALAMOS NATL LAB,DIV EARTH & ENVIRONM SCI,MS D462,LOS ALAMOS,NM 87545, USA. NR 34 TC 13 Z9 13 U1 1 U2 21 PU GEOLOGICAL SOC AMERICA PI BOULDER PA PO BOX 9140 3300 PENROSE PLACE, BOULDER, CO 80301 SN 0016-7606 J9 GEOL SOC AM BULL JI Geol. Soc. Am. Bull. PD DEC PY 1994 VL 106 IS 12 BP 1538 EP & DI 10.1130/0016-7606(1994)106<1538:TWMOTR>2.3.CO;2 PG 0 WC Geosciences, Multidisciplinary SC Geology GA PU924 UT WOS:A1994PU92400003 ER PT J AU BERRYMAN, JG AF BERRYMAN, JG TI CONSTRAINTS ON MINIMUM VELOCITY VARIANCE FOR SEISMIC-TRAVEL-TIME TOMOGRAPHY SO GEOPHYSICAL JOURNAL INTERNATIONAL LA English DT Article DE SEISMIC TOMOGRAPHY; SEISMIC VELOCITIES ID RECONSTRUCTION AB Traveltime data together with known spacing between sources and receivers for seismic-transmission tomography can be used to determine rigorous constraints on the minimum and maximum wave speeds in the propagating medium. These constraints lead to a new minimum variance criterion on inversion algorithms. These results do not improve the velocity reconstructions directly, but provide rigorous and easily computed figures of merit to help evaluate the difficulty of the reconstruction problem and the performance of tomographic-inversion codes. Specifically, these criteria may be used during preprocessing to decide whether linear or non-linear traveltime-tomography methods are required for analysing a given data set, or during post-processing to determine whether regularization methods used to constrain the maximum model variance were overly restrictive. RP BERRYMAN, JG (reprint author), LAWRENCE LIVERMORE NATL LAB,POB 808 L-202,LIVERMORE,CA 94551, USA. RI Berryman, James/A-9712-2008 NR 9 TC 2 Z9 2 U1 0 U2 0 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 DEC PY 1994 VL 119 IS 3 BP 689 EP 692 DI 10.1111/j.1365-246X.1994.tb04008.x PG 4 WC Geochemistry & Geophysics SC Geochemistry & Geophysics GA PW398 UT WOS:A1994PW39800001 ER PT J AU VASCO, DW AF VASCO, DW TI SINGULARITY AND BRANCHING - A PATH-FOLLOWING FORMALISM FOR GEOPHYSICAL INVERSE PROBLEMS SO GEOPHYSICAL JOURNAL INTERNATIONAL LA English DT Article DE GRAVITY GRADIOMETRY; INVERSE PROBLEM; TRAVEL-TIME TOMOGRAPHY ID SOUTHERN OKLAHOMA AULACOGEN; BIFURCATION AB A path-following technique is presented as an alternative to the direct minimization of a misfit functional. The algorithm is based upon the iterative adjustment of an Earth model to fit a set of generated 'data'. These values vary from a purely artificial set, produced from some prior model, to the observed data. The changes in the model that are required to satisfy the conditions for minimum misfit are calculated at each iteration. Multiple solutions appear when the path-following equations become singular and linear approximations fail. Using techniques from singularity theory in Hilbert space, the number, type and stability of solutions appearing at a singular point can be calculated. It is possible to project beyond a singular point and follow the additional solutions that emerge. Thus the algorithm allows one to track multiple solutions to a given inverse problem. The technique is used to infer velocity variations between two boreholes at the Conoco Borehole Test Facility. From a set of 471 arrival times, three velocity models are deduced. All of the models satisfy the conditions for minimum misfit. One model is very similar to the solution produced by a conjugate gradient algorithm. The three models all contain high velocities overlying low velocities. The path-following algorithm is also applied to a set of airborne gravity gradiometry data gathered in SW Oklahoma. An upthrown block of high-density basement material is found to coincide with a positive vertical gravity gradient anomaly. This conclusion agrees with the depths to basement observed in numerous oil wells in the region. C1 UNIV CALIF BERKELEY,SEISMOG STN,BERKELEY,CA 94720. RP VASCO, DW (reprint author), UNIV CALIF BERKELEY,LAWRENCE BERKELEY LAB,CTR COMPUTAT SEISMOL,BERKELEY,CA 94720, USA. RI Vasco, Donald/I-3167-2016 OI Vasco, Donald/0000-0003-1210-8628 NR 57 TC 16 Z9 18 U1 0 U2 5 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 DEC PY 1994 VL 119 IS 3 BP 809 EP 830 DI 10.1111/j.1365-246X.1994.tb04019.x PG 22 WC Geochemistry & Geophysics SC Geochemistry & Geophysics GA PW398 UT WOS:A1994PW39800012 ER PT J AU LI, YQ JACOBSON, AR CARLOS, RC MASSEY, RS TARANENKO, YN WU, G AF LI, YQ JACOBSON, AR CARLOS, RC MASSEY, RS TARANENKO, YN WU, G TI THE BLAST WAVE OF THE SHUTTLE PLUME AT IONOSPHERIC HEIGHTS SO GEOPHYSICAL RESEARCH LETTERS LA English DT Article AB The main engine burn (MEB) of the Space Shuttle deposits similar to 2x10(12) joules of explosive energy and similar to 3x10(5) kg of exhaust in almost horizontal flight at 105-110 km altitude during the period 300-550 s into the ascent. This extremely robust perturbation provides a potential active-excitation source for a variety of geophysical processes, including (1) the effects of aurora-like localized heating on the generation of gravity waves in the thermosphere, (2) the ducting mechanisms for long-period infrasound in the upper atmosphere, (3) dynamo effects associated with transient charge separation, (4) interactions with ambient midlatitude current systems at E-layer heights, and (5) effects in the Earth-ionosphere waveguide of transient electron-density perturbations in the D-region. The sine qua non of such an agenda is to gain a quantitative understanding of the nearfield behavior of the MEB exhaust-plume's quasi-cylindrical expansion, which generates a blast wave propagating away from the explosion. We report on observed electron-density signatures of this blast wave as manifested on lines-of-sight (LOSs) from a very-long-baseline interferometer (VLBI) illuminated by 137-MHz beacon signals from the MARECS-B satellite. We also compare the observations to a preliminary three-dimensional neutral-ah acoustic model coupled to the ionospheric electron density. RP LI, YQ (reprint author), LOS ALAMOS NATL LAB,SPACE & ATMOSPHER SCI GRP,NIS-1,MS D466,LOS ALAMOS,NM 87545, USA. NR 7 TC 26 Z9 27 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 DEC 1 PY 1994 VL 21 IS 24 BP 2737 EP 2740 DI 10.1029/94GL02548 PG 4 WC Geosciences, Multidisciplinary SC Geology GA PV803 UT WOS:A1994PV80300032 ER PT J AU COVEY, C THOMPSON, SL WEISSMAN, PR MACCRACKEN, MC AF COVEY, C THOMPSON, SL WEISSMAN, PR MACCRACKEN, MC TI GLOBAL CLIMATIC EFFECTS OF ATMOSPHERIC DUST FROM AN ASTEROID OR COMET IMPACT ON EARTH SO GLOBAL AND PLANETARY CHANGE LA English DT Article ID CRETACEOUS-TERTIARY BOUNDARY; GENERAL-CIRCULATION MODEL; SMOKE INJECTIONS; NUCLEAR WINTER; SENSITIVITY; EXTINCTIONS; WAR AB Impacts of comets and small (similar to 10 km) asteroids with Earth-frequent events over geologic time-would generate atmospheric dust in amounts orders of magnitude greater than historically large volcanic explosions. Three-dimensional atmospheric model simulations show that climatic effects of such impacts would include drastic cooling of land surfaces due to interception of sunlight by high-altitude dust. Unlike earlier one-dimensional calculations, the three-dimensional results indicate that large areas of the planet would escape freezing. They also suggest catastrophic changes in the hydrological cycle. C1 NATL CTR ATMOSPHER RES,BOULDER,CO 80307. CALTECH,JET PROP LAB,DIV EARTH & SPACE SCI,PASADENA,CA 91125. RP COVEY, C (reprint author), LAWRENCE LIVERMORE NATL LAB,DIV GLOBAL CLIMATE RES,MAIL CODE L-264,LIVERMORE,CA 94551, USA. NR 35 TC 44 Z9 44 U1 2 U2 9 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0921-8181 J9 GLOBAL PLANET CHANGE JI Glob. Planet. Change PD DEC PY 1994 VL 9 IS 3-4 BP 263 EP 273 DI 10.1016/0921-8181(94)90020-5 PG 11 WC Geography, Physical; Geosciences, Multidisciplinary SC Physical Geography; Geology GA PZ127 UT WOS:A1994PZ12700007 ER PT J AU WIGGS, LD JOHNSON, ER COXDEVORE, CA VOELZ, GL AF WIGGS, LD JOHNSON, ER COXDEVORE, CA VOELZ, GL TI MORTALITY THROUGH 1990 AMONG WHITE MALE WORKERS AT THE LOS-ALAMOS-NATIONAL-LABORATORY - CONSIDERING EXPOSURES TO PLUTONIUM AND EXTERNAL IONIZING-RADIATION SO HEALTH PHYSICS LA English DT Article DE PLUTONIUM; MORTALITY; EPIDEMIOLOGY; CANCER ID HANFORD SITE; BRAIN-TUMORS; NUCLEAR; FACILITY; PLANT AB A cohort mortality study was conducted of 15,727 white men employed by the Los Alamos National Laboratory, a nuclear research and development facility. Some of the workers at this facility have been exposed to various forms of ionizing radiation and other potentially hazardous materials. These analyses focused on whole-body ionizing radiation exposures and internal depositions of plutonium. The results indicated that overall mortality among this cohort is quite low, even after nearly 30 y of follow-up. No cause of death was significantly elevated among plutonium-exposed workers when compared with their unexposed coworkers; however, a rate ratio for lung cancer of 1.78 (95% CI = 0.79-3.99) was observed. A case of osteogenic sarcoma, a type of cancer related to plutonium exposure in animal studies, was also observed. Dose-response relationships for whole-body dose from external ionizing radiation and tritium were observed for cancers of the brain/central nervous system, the esophagus, and Hodgkin's disease. RP WIGGS, LD (reprint author), LOS ALAMOS NATL LAB, POB 1663, LOS ALAMOS, NM 87545 USA. NR 34 TC 55 Z9 59 U1 1 U2 2 PU LIPPINCOTT WILLIAMS & WILKINS PI PHILADELPHIA PA 530 WALNUT ST, PHILADELPHIA, PA 19106-3621 USA SN 0017-9078 EI 1538-5159 J9 HEALTH PHYS JI Health Phys. PD DEC PY 1994 VL 67 IS 6 BP 577 EP 588 DI 10.1097/00004032-199412000-00001 PG 12 WC Environmental Sciences; Public, Environmental & Occupational Health; Nuclear Science & Technology; Radiology, Nuclear Medicine & Medical Imaging SC Environmental Sciences & Ecology; Public, Environmental & Occupational Health; Nuclear Science & Technology; Radiology, Nuclear Medicine & Medical Imaging GA PU922 UT WOS:A1994PU92200002 PM 7960779 ER PT J AU LEGGETT, RW AF LEGGETT, RW TI BASIS FOR THE ICRPS AGE-SPECIFIC BIOKINETIC MODEL FOR URANIUM SO HEALTH PHYSICS LA English DT Article DE URANIUM; BIOKINETICS; CHILDREN; KIDNEYS ID DRINKING-WATER; SOFT-TISSUES; OLD RATS; BONE; RETENTION; HUMANS; METABOLISM; ABSORPTION; RESIDENTS; BLOOD AB In an effort motivated largely by the Chernobyl nuclear accident, the International Commission on Radiological Protection (ICRP) is developing age-specific biokinetic models and dose coefficients for environmentally important radionuclides. This paper describes the ICRP's age-specific biokinetic model for uranium. The model is constructed within a physiologically based framework originally developed for application to the alkaline earth elements but sufficiently general to apply to the larger class of bone-volume-seeking elements. Transfer rates for a reference adult are based mainly on: 1. measurements of uranium in blood and excreta of several human subjects who were intravenously injected with uranium; 2. postmortem measurements of uranium in tissues of some of those subjects; 3. postmortem measurements of uranium in tissues of occupationally and non-occupationally exposed subjects; 4. data on baboons, dogs, and smaller laboratory animals exposed to uranium for experimental purposes; and 5. consideration of the physiological processes thought to control retention and translocation of uranium in the body. Transfer rates for the adult are extended to children by application of a set of generic assumptions applied by the ICRP to calcium-like elements. These assumptions were derived mainly from observations of the age-specific biokinetics of the alkaline earth elements and lead in humans and laboratory animals but are consistent with available age-specific biokinetic data on uranium. RP LEGGETT, RW (reprint author), OAK RIDGE NATL LAB, DIV HLTH SCI RES, DOSIMETRY RES GRP, OAK RIDGE, TN 37831 USA. NR 85 TC 55 Z9 57 U1 0 U2 4 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 DEC PY 1994 VL 67 IS 6 BP 589 EP 610 DI 10.1097/00004032-199412000-00002 PG 22 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 PU922 UT WOS:A1994PU92200003 PM 7960780 ER PT J AU THIESSEN, NP AF THIESSEN, NP TI ALPHA-PARTICLE SPECTROSCOPY IN RADON/THORON PROGENY MEASUREMENTS SO HEALTH PHYSICS LA English DT Article DE RADON; RADON PROGENY; SPECTROSCOPY, ALPHA; THORON ID MONITOR; THORON; RADON; AIR AB A comparison is made between the relative variances and counting time requirements for obtaining radon and thoron progeny air concentrations from total alpha count data and from spectroscopically resolved alpha count data collected from air sampling filters. Spectral resolution is shown to have significant advantages, especially in mixed radon/thoron atmospheres. Systematic biases resulting from imperfect energy peak resolution are shown to be subject to accurate mathematical compensation. RP THIESSEN, NP (reprint author), US DOE, GRAND JUNCT PROJECTS OFF, RUST GEOTECH INC, POB 14000, GRAND JCT, CO 81502 USA. NR 16 TC 3 Z9 4 U1 0 U2 0 PU LIPPINCOTT WILLIAMS & WILKINS PI PHILADELPHIA PA 530 WALNUT ST, PHILADELPHIA, PA 19106-3621 USA SN 0017-9078 EI 1538-5159 J9 HEALTH PHYS JI Health Phys. PD DEC PY 1994 VL 67 IS 6 BP 632 EP 640 DI 10.1097/00004032-199412000-00006 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 PU922 UT WOS:A1994PU92200007 PM 7960784 ER PT J AU LUNDBERG, CD PETERSON, MF AF LUNDBERG, CD PETERSON, MF TI THE MEANING OF WORKING IN US AND JAPANESE LOCAL GOVERNMENTS AT 3 HIERARCHICAL LEVELS SO HUMAN RELATIONS LA English DT Article DE COMPARATIVE MANAGEMENT; LOCAL GOVERNMENT; MEANING OF WORKING; JAPANESE MANAGEMENT ID COMMITMENT AB The research program undertaken by the Meaning of Working (MOW) International Research Team has documented effects of individual characteristics and macrosocioeconomic variables on work-related values and beliefs in different countries. The present study adds another dimension to this work by studying intact organizations-local governments in the United States and Japan-in place of the usual MOW samples of occupational groups. The measures used cover the three core facets of the ''Meaning of Working''-work centrality, work goals, and entitlement/obligation norms. By studying intact organizations, the effects of other contextual variables-organization, region, and hierarchical level-in addition to country become evident. C1 TEXAS TECH UNIV,COLL BUSINESS ADM,LUBBOCK,TX 79409. SANDIA NATL LABS,ALBUQUERQUE,NM 87185. NR 20 TC 22 Z9 23 U1 1 U2 7 PU PLENUM PUBL CORP PI NEW YORK PA 233 SPRING ST, NEW YORK, NY 10013 SN 0018-7267 J9 HUM RELAT JI Hum. Relat. PD DEC PY 1994 VL 47 IS 12 BP 1459 EP 1487 DI 10.1177/001872679404701202 PG 29 WC Management; Social Sciences, Interdisciplinary SC Business & Economics; Social Sciences - Other Topics GA PY050 UT WOS:A1994PY05000002 ER PT J AU BERTNESS, KA FRIEDMAN, DJ KURTZ, SR KIBBLER, AE KRAMER, C OLSON, JM AF BERTNESS, KA FRIEDMAN, DJ KURTZ, SR KIBBLER, AE KRAMER, C OLSON, JM TI HIGH-EFFICIENCY GAINP/GAAS TANDEM SOLAR-CELLS SO IEEE AEROSPACE AND ELECTRONIC SYSTEMS MAGAZINE LA English DT Article ID SINGLE-JUNCTION; 2-JUNCTION; GROWTH AB GaInP/GaAs tandem solar cells have achieved new record efficiencies, specifically 25.7% under air-mass 0 (AM0) illumination, 29.5% under AM 1.5 global (AM1.5G) illumination, and 30.2% at 140-180x concentration under AM 1.5 direct (AM1.5D) illumination. These values are the highest two-terminal efficiencies achieved by any solar cell under these illumination conditions. The monolithic, series-connected design of the tandem cells allows them to be substituted for silicon or gallium arsenide cells in photovoltaic panel systems with minimal design changes. The advantages of using GaInP/GaAs tandem solar cells in space and terrestrial applications are discussed primarily in terms of the reduction in balance-of-system costs that accrues when using a higher efficiency cell. The new efficiency values represent a significant improvement over previous efficiencies for this materials system, and we identify grid design, back interface passivation, and top interface passivation as the three key factors leading to this improvement. In producing the high-efficiency cells, we have addressed nondestructive diagnostics and materials growth reproducibility as well as peak cell performance. RP BERTNESS, KA (reprint author), NATL RENEWABLE ENERGY LAB,GOLDEN,CO 80401, USA. NR 31 TC 2 Z9 2 U1 1 U2 7 PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017-2394 SN 0885-8985 J9 IEEE AERO EL SYS MAG JI IEEE Aerosp. Electron. Syst. Mag. PD DEC PY 1994 VL 9 IS 12 BP 12 EP 17 DI 10.1109/62.334755 PG 6 WC Engineering, Aerospace; Engineering, Electrical & Electronic SC Engineering GA PV190 UT WOS:A1994PV19000005 ER PT J AU ZOLPER, JC SHERWIN, ME BACA, AG SHUL, RJ KLEM, JF HIETALA, VM AF ZOLPER, JC SHERWIN, ME BACA, AG SHUL, RJ KLEM, JF HIETALA, VM TI ENHANCED HIGH-FREQUENCY PERFORMANCE IN A GAAS, SELF-ALIGNED, N-JFET USING A CARBON BURIED P-IMPLANT SO IEEE ELECTRON DEVICE LETTERS LA English DT Article ID MESFETS AB C ion implantation has been employed, for the first time, to form the buried p-layer in GaAs, self-aligned, ion implanted JFETs. Comparable DC performance was seen for JFETs with C or Mg implants; however, C-backside JFETs showed superior high-frequency performance. High dose C-backside devices had a f(t) of 28.3 GHz and a f(max) of 43.2 GHz for a 0.5 mu m gate length that were 28% and 46% higher, respectively, than comparable Mg-implanted JFETs. This enhancement is a result of the lower C-gs in the C-backside device resulting from the inherently low activation of the implanted C below the channel while the C still effectively compensated the tail of the Si-channel implant. This approach relaxes the trade-off between optimizing the DC and the AC performance for the buried p-implant in GaAs JFETs and MESFETs. RP ZOLPER, JC (reprint author), SANDIA NATL LABS,POB 5800,ALBUQUERQUE,NM 87185, USA. NR 9 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 0741-3106 J9 IEEE ELECTR DEVICE L JI IEEE Electron Device Lett. PD DEC PY 1994 VL 15 IS 12 BP 493 EP 495 DI 10.1109/55.338414 PG 3 WC Engineering, Electrical & Electronic SC Engineering GA PY914 UT WOS:A1994PY91400002 ER PT J AU LOTT, JA SCHNEIDER, RP MALLOY, KJ KILCOYNE, SP CHOQUETTE, KD AF LOTT, JA SCHNEIDER, RP MALLOY, KJ KILCOYNE, SP CHOQUETTE, KD TI PARTIAL TOP DIELECTRIC STACK DISTRIBUTED BRAGG REFLECTORS FOR RED VERTICAL-CAVITY SURFACE-EMITTING LASER ARRAYS SO IEEE PHOTONICS TECHNOLOGY LETTERS LA English DT Article ID DIODES AB Room temperature continuous wave operation of red (lambda(0) similar to 660 mm) vertical cavity surface emitting laser arrays is reported, The 1 x 64 arrays have a pitch of 100 mu m with device diameters of 15 mu m. Grown by metalorganic vapor phase epitaxy, the devices consist of an AlGaInP strained quantum well optical cavity active region surrounded by AlGaAs distributed Bragg reflectors (DBR's), The top coupling DBR includes a partial dielectric stack, deposited after implanted device fabrication, All 64 devices operate simultaneously with peak output powers >0.45 mW, threshold currents <1.5 mA, and threshold voltages less than or equal to 2.7 V, The differential quantum efficiencies exceed 10%. C1 SANDIA NATL LABS,CTR MICROELECTR & PHOTON,ALBUQUERQUE,NM 87185. UNIV NEW MEXICO,CTR HIGH TECHNOL MAT,ALBUQUERQUE,NM 87131. RP LOTT, JA (reprint author), USAF,INST TECHNOL,DEPT ELECT & COMP ENGN,WRIGHT PATTERSON AFB,OH 45433, USA. RI Malloy, Kevin/E-5994-2010 NR 16 TC 7 Z9 7 U1 0 U2 2 PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017-2394 SN 1041-1135 J9 IEEE PHOTONIC TECH L JI IEEE Photonics Technol. Lett. PD DEC PY 1994 VL 6 IS 12 BP 1397 EP 1399 DI 10.1109/68.392232 PG 3 WC Engineering, Electrical & Electronic; Optics; Physics, Applied SC Engineering; Optics; Physics GA QB709 UT WOS:A1994QB70900001 ER PT J AU WU, CH ZORY, PS EMANUEL, MA AF WU, CH ZORY, PS EMANUEL, MA TI CONTACT REFLECTIVITY EFFECTS ON THIN P-CLAD INGAAS SINGLE-QUANTUM-WELL LASERS SO IEEE PHOTONICS TECHNOLOGY LETTERS LA English DT Article ID THRESHOLD CURRENT; DIODE-LASERS; GAAS; DEPENDENCE; INDEX AB Thin p-clad InGaAs quantum-well (QW) lasers with either Au or Ni as the p-contact metal have been fabricated, Due to reduced contact reflectivity, the Ni contact lasers have significantly higher threshold currents and lower slope efficiencies than the Au contact lasers. In addition, operating wavelength differences greater than 50 nm are observed for cavity lengths between 250 and 700 microns, with large wavelength jumps occurring at shorter and longer cavity lengths, The measured wavelength effects are explained by incorporating the optical mode loss difference between the two laser types into quantum-well laser theory, C1 LAWRENCE LIVERMORE NATL LAB,LIVERMORE,CA 94550. RP WU, CH (reprint author), UNIV FLORIDA,DEPT ELECT ENGN,GAINESVILLE,FL 32611, USA. NR 18 TC 18 Z9 18 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 1041-1135 J9 IEEE PHOTONIC TECH L JI IEEE Photonics Technol. Lett. PD DEC PY 1994 VL 6 IS 12 BP 1427 EP 1429 DI 10.1109/68.392222 PG 3 WC Engineering, Electrical & Electronic; Optics; Physics, Applied SC Engineering; Optics; Physics GA QB709 UT WOS:A1994QB70900011 ER PT J AU DAVIDSON, BA REDWING, RD NGUYEN, T OCALLAGHAN, J RAISSI, F LEE, JU BURKE, JP HOHENWARTER, GKG NORDMAN, JE BEYER, JB LIOU, SH ECKSTEIN, J SIEGAL, MP HOU, SY PHILLIPS, JM AF DAVIDSON, BA REDWING, RD NGUYEN, T OCALLAGHAN, J RAISSI, F LEE, JU BURKE, JP HOHENWARTER, GKG NORDMAN, JE BEYER, JB LIOU, SH ECKSTEIN, J SIEGAL, MP HOU, SY PHILLIPS, JM TI MAGNETIC-FIELD SENSITIVITY OF VARIABLE THICKNESS MICROBRIDGES IN TBCCO, BSCCO, AND YBCO SO IEEE TRANSACTIONS ON APPLIED SUPERCONDUCTIVITY LA English DT Article ID TRANSPORT-PROPERTIES; THIN-FILMS; SUPERCONDUCTOR AB We describe results of a study comparing the magnetic field sensitivities of variable thickness bridge (VTB) arrays fabricated in TBCCO, BSCCO, and YBCO thin films. Identical structures were patterned in a variety of films, and the bridges were thinned by four different methods. Analysis of the data yields experimental evidence as to the suitability of these types of films for devices such as the superconducting flux flow transistor (SFFT) which is based on this geometry. The volt-ampere characteristics of the arrays were measured in low uniform magnetic fields (less-than-or-equal-to 130 G) and in nonuniform fields (less-than-or-equal-to 5 G) produced by a nearby control line. For these films in this geometry, no measurable effect of the control line magnetic field was observed. Large values of transresistance and current gain could only be attained through a thermal mechanism when the control line was driven normal. Upper bounds for (magnetically generated) transresistance (less-than-or-equal-to mOMEGA) and current gains (less-than-or-equal-to 0.005) have been inferred from the uniform field data assuming a standard best-case device geometry. All volt-ampere curves followed closely a power law relationship (V approximately I(n)), with exponent n approximately 1.2-10. We suggest materials considerations that may yield improved device performance. C1 PARKVIEW R&D,MADISON,WI 53711. VARIAN RES CTR,PALO ALTO,CA 94304. AT&T BELL LABS,MURRAY HILL,NJ 07974. UNIV NEBRASKA,DEPT PHYS,LINCOLN,NE 68588. SANDIA NATL LABS,ALBUQUERQUE,NM 87185. RP DAVIDSON, BA (reprint author), UNIV WISCONSIN,DEPT ECE,MADISON,WI 53706, USA. RI Davidson, Bruce/C-6010-2009; O'Callaghan, Juan /F-6595-2013 OI Davidson, Bruce/0000-0003-1616-9380; O'Callaghan, Juan /0000-0002-2740-0202 NR 25 TC 19 Z9 19 U1 0 U2 2 PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017-2394 SN 1051-8223 J9 IEEE T APPL SUPERCON JI IEEE Trans. Appl. Supercond. PD DEC PY 1994 VL 4 IS 4 BP 228 EP 235 DI 10.1109/77.334964 PG 8 WC Engineering, Electrical & Electronic; Physics, Applied SC Engineering; Physics GA PV183 UT WOS:A1994PV18300008 ER PT J AU DREIKE, PL FLEETWOOD, DM KING, DB SPRAUER, DC ZIPPERIAN, TE AF DREIKE, PL FLEETWOOD, DM KING, DB SPRAUER, DC ZIPPERIAN, TE TI AN OVERVIEW OF HIGH-TEMPERATURE ELECTRONIC DEVICE TECHNOLOGIES AND POTENTIAL APPLICATIONS SO IEEE TRANSACTIONS ON COMPONENTS PACKAGING AND MANUFACTURING TECHNOLOGY PART A LA English DT Article ID SURFACE-EMITTING LASER; SILICON-CARBIDE; DIFFERENTIAL-AMPLIFIER; UV PHOTODIODES; GAAS; OPERATION; 300-DEGREES-C; REQUIREMENTS; SYSTEMS; GROWTH AB High-temperature electronics applications are found in combustion systems, well logging, industrial processes, air stagnation points in supersonic aircraft, vehicle brakes, nuclear reactors, and dense electronic packages. We summarize physical effects and materials issues important for reliable operation of semiconductor device technologies at high temperatures (>(125)degrees C). We review the high-temperature potential of Si, GaAs, other III-V compounds, and SiC. For completeness, we also comment on nitrides, diamond, and vacuum microeleetronics. We conclude that Si on insulator (SOI) technology can be developd readily for small signal operation up to about 300 degrees C. There is some ongoing work in this area. GaAs offers little advantage over Si because of poor device isolation and the lack of reliable contacts above 250 degrees C. Other m-V compounds could be developed for operation to similar to 600 degrees C, using processes similar to those used for optoelectronics. There may be a market niche for III-V power devices above 200 degrees C. There is considerable activity in semiconducting SiC, and device functionality has been demonstrated above 600 degrees C. SiC is promising for operation above 300 degrees C, and for power devices at frequencies from dc to similar to 10 GHz, but it faces numerous challenges to achieve manufacturable status. We attempt to match technologies with application areas. C1 SANDIA NATL LABS,DIV RADIAT TECHNOL & ASSURANCE,ALBUQUERQUE,NM. RP DREIKE, PL (reprint author), SANDIA NATL LABS,DEPT RELIABIL PHYS,DIV TARGET EXPT,TECH STAFF,ALBUQUERQUE,NM 87185, USA. NR 83 TC 63 Z9 64 U1 2 U2 17 PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017-2394 SN 1070-9886 J9 IEEE T COMPON PACK A JI IEEE Trans Compon. Packag. Manuf. Technol. Part A PD DEC PY 1994 VL 17 IS 4 BP 594 EP 609 DI 10.1109/95.335047 PG 16 WC Engineering, Manufacturing; Engineering, Electrical & Electronic; Materials Science, Multidisciplinary SC Engineering; Materials Science GA PW500 UT WOS:A1994PW50000017 ER PT J AU LIU, P BAHADUR, S VERHOEVEN, JD AF LIU, P BAHADUR, S VERHOEVEN, JD TI ELECTRICAL SLIDING FRICTION AND WEAR BEHAVIOR OF CU-NB IN-SITU COMPOSITES SO IEEE TRANSACTIONS ON COMPONENTS PACKAGING AND MANUFACTURING TECHNOLOGY PART A LA English DT Article ID TRIBOLOGICAL BEHAVIOR; ALLOYS AB The sliding friction and wear behavior of Cu-Nb in situ composites was studied in the presence of electrical load. Electrical sliding was performed between a Cu-Nb composite pin and a flat surface of a hardened tool steel disk in ambient atmosphere. The effects of Nb proportion, electrical current density, sliding speed, and Nb-filament orientation on the friction and wear behavior were investigated. It was found that the coefficient of friction decreased with increasing Nb proportion and Cu-20vol.%Nb has the best wear resistance. Both the coefficient of friction and wear rate increased as a small electrical current was applied and then decreased as the current density increased. With increase in sliding speed, the coefficient of friction and wear on the Cu-Nb composite decreased. The composite with Nb-filaments perpendicular to sliding direction was found to have higher wear resistance than that of parallel orientation. The deformation layer and oxide film of the composite are much thicker at electrical sliding than nonelectrical sliding. The surface oxide played a key role in governing the sliding friction and wear behavior of the Cu-Nb composites under electrical current. C1 IOWA STATE UNIV SCI & TECHNOL,DEPT MECH ENGN,AMES,IA 50011. IOWA STATE UNIV SCI & TECHNOL,DEPT MAT SCI & ENGN,US DOE,AMES LAB,AMES,IA 50011. RP LIU, P (reprint author), EASTERN ILLINOIS UNIV,SCH TECHNOL,CHARLESTON,IL 61920, USA. NR 22 TC 8 Z9 11 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 1070-9886 J9 IEEE T COMPON PACK A JI IEEE Trans Compon. Packag. Manuf. Technol. Part A PD DEC PY 1994 VL 17 IS 4 BP 616 EP 624 DI 10.1109/95.335042 PG 9 WC Engineering, Manufacturing; Engineering, Electrical & Electronic; Materials Science, Multidisciplinary SC Engineering; Materials Science GA PW500 UT WOS:A1994PW50000019 ER PT J AU OLDMAN, TR FLEETWOOD, DM CHEEK, T MASSENGILL, L VANVONNO, N SHANEYFELT, MR EISEN, H BOESCH, HE SCHRIMPF, RD CAMPBELL, A BENDEKOVIC, J EMILY, D GRAWET, S MARSHALL, P BUCHNER, S GASIOT, J COSS, J KRULL, W FARREN, J FREDERICKSON, R LELIS, A AMRAM, A LENAHAN, P AF OLDMAN, TR FLEETWOOD, DM CHEEK, T MASSENGILL, L VANVONNO, N SHANEYFELT, MR EISEN, H BOESCH, HE SCHRIMPF, RD CAMPBELL, A BENDEKOVIC, J EMILY, D GRAWET, S MARSHALL, P BUCHNER, S GASIOT, J COSS, J KRULL, W FARREN, J FREDERICKSON, R LELIS, A AMRAM, A LENAHAN, P TI SUMMARY OF THE 1994 IEEE INTERNATIONAL NUCLEAR AND SPACE RADIATION EFFECTS CONFERENCE SO IEEE TRANSACTIONS ON NUCLEAR SCIENCE LA English DT Editorial Material C1 SANDIA NATL LABS,LIVERMORE,CA 94550. TEXAS INSTRUMENTS INC,DALLAS,TX 75265. VANDERBILT UNIV,NASHVILLE,TN 37240. HARRIS SEMICOND INC,MELBOURNE,FL 32901. UNIV ARIZONA,TUCSON,AZ 85721. USN,RES LAB,WASHINGTON,DC 20375. UNIV MONTPELLIER 2,F-34095 MONTPELLIER,FRANCE. JET PROPULS LAB,PASADENA,CA. IBIS TECHNOL CORP,DANVERS,MA. UKAEA,HARWELL INSTRUMENTS,HARWELL,BERKS,ENGLAND. AEROSP CORP,LOS ANGELES,CA 90009. PENN STATE UNIV,UNIVERSITY PK,PA 16802. RP OLDMAN, TR (reprint author), USA,RES LAB,WASHINGTON,DC, USA. RI Schrimpf, Ronald/L-5549-2013 OI Schrimpf, Ronald/0000-0001-7419-2701 NR 0 TC 0 Z9 0 U1 1 U2 1 PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017-2394 SN 0018-9499 J9 IEEE T NUCL SCI JI IEEE Trans. Nucl. Sci. PD DEC PY 1994 VL 41 IS 6 BP 1804 EP 1807 PN 1 PG 4 WC Engineering, Electrical & Electronic; Nuclear Science & Technology SC Engineering; Nuclear Science & Technology GA PZ157 UT WOS:A1994PZ15700001 ER PT J AU WARREN, WL SHANEYFELT, MR FLEETWOOD, DM SCHWANK, JR WINOKUR, PS DEVINE, RAB AF WARREN, WL SHANEYFELT, MR FLEETWOOD, DM SCHWANK, JR WINOKUR, PS DEVINE, RAB TI MICROSCOPIC NATURE OF BORDER TRAPS IN MOS OXIDES SO IEEE TRANSACTIONS ON NUCLEAR SCIENCE LA English DT Article; Proceedings Paper CT 1994 IEEE Annual Conference on Nuclear and Space Radiation Effects (NSREC 94) CY JUL 18-22, 1994 CL TUCSON, AZ SP IEEE ID INTERFACE-STATE GENERATION; SEMICONDUCTOR DEVICES; OXYGEN-VACANCY; SI-SIO2 INTERFACE; SI/SIO2 INTERFACE; POSITIVE CHARGE; SILICON DIOXIDE; BURIED SIO2; HOLE TRAPS; E' CENTERS AB We show that enhanced hole-, electron-, interface-, and border-trap generation in irradiated Si/SiO2/Si systems that have received a high-temperature anneal during device fabrication is related either directly, or indirectly, to the presence of anneal-created oxygen vacancies. The high-temperature anneal results are shown to be relevant to understanding defect creation in zone-melt-recrystallized silicon on insulator materials. We observe the electron paramagnetic resonance (EPR) of trap-assisted hole transfer between two different oxygen vacancy-type defects (E'(delta)-->E'(gamma) precursor) in hole injected thermal SiO2 films. Upon annealing the hole injected Si/SiO2 structures at room temperature, the E'(delta) center transfers its hole to a previously neutral oxygen vacancy (O-3=Si-Si=O-3) site forming an E'(gamma) center. This process, also monitored electrically, shows a concomitant increase in the border-trap density that mimics the growth kinetics of the transfer-activated E'(gamma) centers. This suggests that both effects are correlated and that some of the transfer-created E'(gamma) centers are the entities responsible for the border traps in these devices. One implication of these results is that delayed defect growth processes can occur via slow trap-assisted hole motion in SiO2. C1 FRANCE TELECOM,CTR NATL ETUD TELECOMMUN,F-38243 MEYLAN,FRANCE. RP WARREN, WL (reprint author), SANDIA NATL LABS,POB 5800,ALBUQUERQUE,NM 87185, USA. NR 54 TC 82 Z9 84 U1 1 U2 12 PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017-2394 SN 0018-9499 J9 IEEE T NUCL SCI JI IEEE Trans. Nucl. Sci. PD DEC PY 1994 VL 41 IS 6 BP 1817 EP 1827 DI 10.1109/23.340513 PN 1 PG 11 WC Engineering, Electrical & Electronic; Nuclear Science & Technology SC Engineering; Nuclear Science & Technology GA PZ157 UT WOS:A1994PZ15700003 ER PT J AU SAKS, NS SIMONS, M FLEETWOOD, DM YOUNT, JT LENAHAN, PM KLEIN, RB AF SAKS, NS SIMONS, M FLEETWOOD, DM YOUNT, JT LENAHAN, PM KLEIN, RB TI RADIATION EFFECTS IN OXYNITRIDES GROWN IN N2O SO IEEE TRANSACTIONS ON NUCLEAR SCIENCE LA English DT Article; Proceedings Paper CT 1994 IEEE Annual Conference on Nuclear and Space Radiation Effects (NSREC 94) CY JUL 18-22, 1994 CL TUCSON, AZ SP IEEE ID INTERFACIAL NITROGEN; NITRIDED OXIDES; SIO2; FIELD; BREAKDOWN; MOSFETS; CHARGE; HARD AB Oxynitrides have been grown by oxidation in N2O in a standard thermal oxidation furnace. Two N2O processes have been studied: oxidation in N2O only, and two-step oxidation with initial oxidation in O-2 followed by oxidation/nitridation in N2O. Results are presented for radiation damage at 80 and 295K, hole trapping, interface trap creation, electron spin resonance, and hole de-trapping using thermally-stimulated current analysis. N2O oxynitrides do not appear to have the well-known. drawbacks of NH3-annealed oxynitrides. Creation of interface traps during irradiation is reduced in the N2O oxynitrides, with the degree of improvement depending on the fabrication process. C1 RES TRIANGLE INST,RES TRIANGLE PK,NC 27709. SANDIA NATL LABS,ALBUQUERQUE,NM 87185. PENN STATE UNIV,UNIVERSITY PK,PA 16802. SFA INC,LANDOVER,MD 20785. RP SAKS, NS (reprint author), USN,RES LAB,WASHINGTON,DC 20375, USA. NR 31 TC 20 Z9 20 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 0018-9499 J9 IEEE T NUCL SCI JI IEEE Trans. Nucl. Sci. PD DEC PY 1994 VL 41 IS 6 BP 1854 EP 1863 DI 10.1109/23.340517 PN 1 PG 10 WC Engineering, Electrical & Electronic; Nuclear Science & Technology SC Engineering; Nuclear Science & Technology GA PZ157 UT WOS:A1994PZ15700007 ER PT J AU FLEETWOOD, DM KOSIER, SL NOWLIN, RN SCHRIMPF, RD REBER, RA DELAUS, M WINOKUR, PS WEI, A COMBS, WE PEASE, RL AF FLEETWOOD, DM KOSIER, SL NOWLIN, RN SCHRIMPF, RD REBER, RA DELAUS, M WINOKUR, PS WEI, A COMBS, WE PEASE, RL TI PHYSICAL-MECHANISMS CONTRIBUTING TO ENHANCED BIPOLAR GAIN DEGRADATION AT LOW-DOSE RATES SO IEEE TRANSACTIONS ON NUCLEAR SCIENCE LA English DT Article; Proceedings Paper CT 1994 IEEE Annual Conference on Nuclear and Space Radiation Effects (NSREC 94) CY JUL 18-22, 1994 CL TUCSON, AZ SP IEEE ID OXIDE-SEMICONDUCTOR DEVICES; X-RAY; MOS DEVICES; CO-60 IRRADIATIONS; RADIATION RESPONSE; BORDER TRAPS; CHARGE; SIO2; TRANSISTORS; TEMPERATURE AB We have performed capacitance-voltage (C-V) and thermally-stimulated-current (TSC) measurements on non-radiation-hard MOS capacitors simulating screen oxides of modern bipolar technologies. For 0-V irradiation at similar to 25 degrees C, the net trapped-positive-charge density (N-ox) inferred from midgap C-V shifts is similar to 25-40% greater for low-dose-rate (< 10 rad(SiO2)/s) than for high-dose-rate (> 100 rad(SiO2)/s) exposure. Device modeling shows that such a difference in screen-oxide N-ox is enough to account for the enhanced low-rate gain degradation often observed in bipolar devices, due to the similar to exp (N-ox(2)) dependence of the excess base current. At the higher rates, TSC measurements reveal a similar to 10% decrease in trapped-hole density over low rates. Also, at high rates, up to similar to 2.5-times as many trapped holes are compensated by electrons in border traps than at low rates for these devices and irradiation conditions. Both the reduction in trapped-hole density and increased charge compensation reduce the high-rate midgap shift. A physical model is developed which suggests that both effects are caused by time-dependent space charge in the bulk of these soft oxides associated with slowly transporting and/or metastably trapped holes (e. g., in E(delta)' centers). On the basis of this model, bipolar transistors and screen-oxide capacitors were irradiated at 60 degrees C at 200 rad(SiO2)/s in a successful effort to match low-rate damage. These surprising results provide insight into enhanced low-rate bipolar gain degradation and suggest potentially promising new approaches to bipolar and BICMOS hardness assurance for space applications. C1 UNIV ARIZONA,DEPT ECE,TUCSON,AZ 85721. PHILLIPS LAB,VTE,ALBUQUERQUE,NM 87185. ANALOG DEVICES INC,WILMINGTON,MA 01887. USN,CTR SURFACE WARFARE,CRANE,IN 47522. RLP RES INC,ALBUQUERQUE,NM 87122. RP FLEETWOOD, DM (reprint author), SANDIA NATL LABS,POB 5800,ALBUQUERQUE,NM 87185, USA. RI Schrimpf, Ronald/L-5549-2013 OI Schrimpf, Ronald/0000-0001-7419-2701 NR 54 TC 157 Z9 198 U1 3 U2 11 PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017-2394 SN 0018-9499 J9 IEEE T NUCL SCI JI IEEE Trans. Nucl. Sci. PD DEC PY 1994 VL 41 IS 6 BP 1871 EP 1883 DI 10.1109/23.340519 PN 1 PG 13 WC Engineering, Electrical & Electronic; Nuclear Science & Technology SC Engineering; Nuclear Science & Technology GA PZ157 UT WOS:A1994PZ15700009 ER PT J AU EREMIN, V LI, Z AF EREMIN, V LI, Z TI DETERMINATION OF THE FERMI-LEVEL POSITION FOR NEUTRON-IRRADIATED HIGH-RESISTIVITY SILICON DETECTORS AND MATERIALS USING THE TRANSIENT CHARGE TECHNIQUE (TCHT) SO IEEE TRANSACTIONS ON NUCLEAR SCIENCE LA English DT Article; Proceedings Paper CT 1994 IEEE Annual Conference on Nuclear and Space Radiation Effects (NSREC 94) CY JUL 18-22, 1994 CL TUCSON, AZ SP IEEE ID RADIATION AB The transient charge technique (TChT) has been used in this work to study the electrical properties in both space charge region (SCR) and electrical neutral bulk (ENB) of neutron irradiated high resistivity (4-6 k Omega-cm) silicon particle detectors. Detectors irradiated to various neutron fluences were measured by TChT at various biases and temperatures from 110 K to 300 K. The Fermi level, obtained from the Arrhenius plot of the time constant of the ohmic relaxation component of the charge shape, has been found to stabilize around E(c)-0.47 to 0.50 eV at high fluences (Phi(n)>10(13) n/cm(2)). C1 RUSSIAN ACAD SCI,AF IOFFE PHYSICOTECH INST,ST PETERSBURG 196140,RUSSIA. RP EREMIN, V (reprint author), BROOKHAVEN NATL LAB,UPTON,NY 11973, USA. NR 14 TC 37 Z9 37 U1 0 U2 1 PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017-2394 SN 0018-9499 J9 IEEE T NUCL SCI JI IEEE Trans. Nucl. Sci. PD DEC PY 1994 VL 41 IS 6 BP 1907 EP 1912 DI 10.1109/23.340522 PN 1 PG 6 WC Engineering, Electrical & Electronic; Nuclear Science & Technology SC Engineering; Nuclear Science & Technology GA PZ157 UT WOS:A1994PZ15700013 ER PT J AU DODD, PE SEXTON, FW WINOKUR, PS AF DODD, PE SEXTON, FW WINOKUR, PS TI 3-DIMENSIONAL SIMULATION OF CHARGE COLLECTION AND MULTIPLE-BIT UPSET IN SI DEVICES SO IEEE TRANSACTIONS ON NUCLEAR SCIENCE LA English DT Article; Proceedings Paper CT 1994 IEEE Annual Conference on Nuclear and Space Radiation Effects (NSREC 94) CY JUL 18-22, 1994 CL TUCSON, AZ SP IEEE ID SINGLE-EVENT; NUMERICAL-SIMULATION; ION TRACKS; SILICON; SEU; ERRORS; TRANSPORT; CIRCUIT; MODEL; SRAMS AB In this paper, three-dimensional numerical simulation is used to explore the basic charge-collection mechanisms in silicon n(+)/p diodes. For diodes on lightly-doped substrates (<1x10(15) cm(-3)) struck by a 100-MeV Fe ion, the funneling effect is very strong and essentially all collection is by funnel-assisted drift. This drift collection may occur as late as several nanoseconds after the strike, later than is usually associated with drift collection. For moderately doped substrates (=1x10(16) cm(-3)) and epitaxial structures grown on heavily-doped substrates, the funnel effect is weaker and drift and diffusion are of more equal importance. For 5-MeV He (alpha-particle) strikes with low-density charge tracks, the charge-collection transient exhibits both drift and diffusion regimes regardless of the substrate doping. Simulations of diodes with passive external loads indicate that while the current response is altered considerably by the load, total collected charge is not greatly affected for the simple resistive loads studied. Three-dimensional mixed-mode simulation is performed to investigate charge-collection behavior and upset mechanisms in complete CMOS SRAM cells. Simulations of double SRAM cell structures indicate that only collection by diffusion from ''between-node'' strikes is capable of producing multiple-bit upsets in the simulated technology. Limitations of the simulations, specifically carrier-carrier scattering models and large concentration gradients, are also discussed. RP DODD, PE (reprint author), SANDIA NATL LABS,POB 5800,ALBUQUERQUE,NM 87185, USA. NR 45 TC 78 Z9 88 U1 0 U2 3 PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017-2394 SN 0018-9499 J9 IEEE T NUCL SCI JI IEEE Trans. Nucl. Sci. PD DEC PY 1994 VL 41 IS 6 BP 2005 EP 2017 DI 10.1109/23.340536 PN 1 PG 13 WC Engineering, Electrical & Electronic; Nuclear Science & Technology SC Engineering; Nuclear Science & Technology GA PZ157 UT WOS:A1994PZ15700026 ER PT J AU KELLY, JG SITES, KR SCOTT, WH AF KELLY, JG SITES, KR SCOTT, WH TI FAST SHUTTER FOR LOW-BACKGROUND RADIATION ENVIRONMENTS AT SPR-III SO IEEE TRANSACTIONS ON NUCLEAR SCIENCE LA English DT Article; Proceedings Paper CT 1994 IEEE Annual Conference on Nuclear and Space Radiation Effects (NSREC 94) CY JUL 18-22, 1994 CL TUCSON, AZ SP IEEE AB A fast shutter system has been developed to isolate experiments from the radiation emitted after the main pulse of the Sandia Pulsed Reactor, SPR III. In about 15 ms the system moves a 20 kg shield in front of the beam port aperture in the facility shield wall. A second gravity-driven shutter is dropped into place in about 200 ms. The total attenuation achieved in the delayed beam intensity is about a factor of one hundred. The shutter assembly was used, along with a sensitive detection system, to observe the gamma ray flux emitted by various materials activated by the neutron beam at levels nine orders of magnitude smaller than the gamma dose rate at the target during the reactor pulse. C1 SCI APPLICAT INT CORP,LAS VEGAS,NV 89109. RP KELLY, JG (reprint author), SANDIA NATL LABS,POB 5800,ALBUQUERQUE,NM 87185, USA. NR 2 TC 1 Z9 1 U1 1 U2 1 PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017-2394 SN 0018-9499 J9 IEEE T NUCL SCI JI IEEE Trans. Nucl. Sci. PD DEC PY 1994 VL 41 IS 6 BP 2125 EP 2131 DI 10.1109/23.340552 PN 1 PG 7 WC Engineering, Electrical & Electronic; Nuclear Science & Technology SC Engineering; Nuclear Science & Technology GA PZ157 UT WOS:A1994PZ15700042 ER PT J AU WILLIAMS, JG GRIFFIN, PJ KELLY, JG FIGUEROA, JT AF WILLIAMS, JG GRIFFIN, PJ KELLY, JG FIGUEROA, JT TI ESTIMATION OF 1-MEV EQUIVALENT NEUTRON FLUENCE FROM DOSIMETRY RESPONSES WITHOUT SPECTRUM UNFOLDING SO IEEE TRANSACTIONS ON NUCLEAR SCIENCE LA English DT Article; Proceedings Paper CT 1994 IEEE Annual Conference on Nuclear and Space Radiation Effects (NSREC 94) CY JUL 18-22, 1994 CL TUCSON, AZ SP IEEE AB The paper demonstrates the estimation of 1-MeV equivalent (Si) neutron fluence from radiometric monitor data without prior spectrum knowledge and without estimation of the neutron fluence spectrum. C1 SANDIA NATL LABS,ALBUQUERQUE,NM 87185. RP WILLIAMS, JG (reprint author), UNIV ARIZONA,TUCSON,AZ 85721, USA. NR 8 TC 6 Z9 6 U1 0 U2 0 PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017-2394 SN 0018-9499 J9 IEEE T NUCL SCI JI IEEE Trans. Nucl. Sci. PD DEC PY 1994 VL 41 IS 6 BP 2147 EP 2151 DI 10.1109/23.340555 PN 1 PG 5 WC Engineering, Electrical & Electronic; Nuclear Science & Technology SC Engineering; Nuclear Science & Technology GA PZ157 UT WOS:A1994PZ15700045 ER PT J AU NORMAND, E OBERG, DL WERT, JL NESS, JD MAJEWSKI, PP WENDER, S GAVRON, A AF NORMAND, E OBERG, DL WERT, JL NESS, JD MAJEWSKI, PP WENDER, S GAVRON, A TI SINGLE EVENT UPSET AND CHARGE COLLECTION MEASUREMENTS USING HIGH-ENERGY PROTONS AND NEUTRONS SO IEEE TRANSACTIONS ON NUCLEAR SCIENCE LA English DT Article; Proceedings Paper CT 1994 IEEE Annual Conference on Nuclear and Space Radiation Effects (NSREC 94) CY JUL 18-22, 1994 CL TUCSON, AZ SP IEEE ID UPPER-ATMOSPHERE; ENVIRONMENT AB RAMs, microcontrollers and surface barrier detectors were exposed to beams of high energy protons and neutrons to measure the induced number of upsets as well as energy deposition. The WNR facility at Los Alamos provided a neutron spectrum similar to that of the atmospheric neutrons. Its effect on devices was compared to that of protons with energies of 200, 400, 500 and 800 MeV. Measurements indicate that SEU cross sections for 400 MeV protons are similar to those induced by the atmospheric neutron spectrum. C1 LOS ALAMOS NATL LAB,LOS ALAMOS,NM 87545. RP NORMAND, E (reprint author), BOEING DEF & SPACE GRP,SEATTLE,WA 98124, USA. NR 27 TC 32 Z9 32 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 0018-9499 J9 IEEE T NUCL SCI JI IEEE Trans. Nucl. Sci. PD DEC PY 1994 VL 41 IS 6 BP 2203 EP 2209 DI 10.1109/23.340563 PN 1 PG 7 WC Engineering, Electrical & Electronic; Nuclear Science & Technology SC Engineering; Nuclear Science & Technology GA PZ157 UT WOS:A1994PZ15700053 ER PT J AU HASH, GL SCHWANK, JR SHANEYFELT, MR SANDOVAL, CE CONNORS, MP SHERIDAN, TJ SEXTON, FW SLAYTON, EM HEISE, JA FOSTER, CC AF HASH, GL SCHWANK, JR SHANEYFELT, MR SANDOVAL, CE CONNORS, MP SHERIDAN, TJ SEXTON, FW SLAYTON, EM HEISE, JA FOSTER, CC TI PROTON IRRADIATION EFFECTS ON ADVANCED DIGITAL AND MICROWAVE III-V COMPONENTS SO IEEE TRANSACTIONS ON NUCLEAR SCIENCE LA English DT Article; Proceedings Paper CT 1994 IEEE Annual Conference on Nuclear and Space Radiation Effects (NSREC 94) CY JUL 18-22, 1994 CL TUCSON, AZ SP IEEE ID RADIATION HARDNESS; GAAS; UPSETS AB A wide range of advanced III-V components suitable for use in high-speed satellite communication systems were evaluated for displacement damage and single-event effects in high-energy, high-fluence proton environments. Transistors and integrated circuits (both digital and MMIC) were irradiated with protons at energies from 41 to 197 MeV and at fluences from 10(10) to 2x10(14) protons/cm(2). Large soft-error rate were measured for digital GaAs MESFET (3x10(-5) errors/bit-day) and heterojunction bipolar circuits (10(-5) errors/bit-day). No transient signals were detected from MMIC circuits. The largest degradation in transistor response caused by displacement damage was observed for 1.0-mu m depletion- and enhancement-mode MESFET transistors. Shorter gate length MESFET transistors and HEMT transistors exhibited less displacement-induced damage. These results show that memory-intensive GaAs digital circuits may result in significant system degradation due to single-event upset in natural and man-made space environments. However, displacement damage effects should not be a limiting factor for fluence levels up to 10(14) protons/cm(2) [equivalent to total doses in excess of 10 Mrad(GaAs)]. C1 INDIANA UNIV,CYCLOTRON FACIL,BLOOMINGTON,IN. RP HASH, GL (reprint author), SANDIA NATL LABS,ALBUQUERQUE,NM 87185, USA. NR 9 TC 9 Z9 9 U1 1 U2 4 PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017-2394 SN 0018-9499 J9 IEEE T NUCL SCI JI IEEE Trans. Nucl. Sci. PD DEC PY 1994 VL 41 IS 6 BP 2259 EP 2266 DI 10.1109/23.340573 PN 1 PG 8 WC Engineering, Electrical & Electronic; Nuclear Science & Technology SC Engineering; Nuclear Science & Technology GA PZ157 UT WOS:A1994PZ15700062 ER PT J AU SHANEYFELT, MR WINOKUR, PS MEISENHEIMER, TL SEXTON, FW ROESKE, SB KNOLL, MG AF SHANEYFELT, MR WINOKUR, PS MEISENHEIMER, TL SEXTON, FW ROESKE, SB KNOLL, MG TI HARDNESS VARIABILITY IN COMMERCIAL TECHNOLOGIES SO IEEE TRANSACTIONS ON NUCLEAR SCIENCE LA English DT Article; Proceedings Paper CT 1994 IEEE Annual Conference on Nuclear and Space Radiation Effects (NSREC 94) CY JUL 18-22, 1994 CL TUCSON, AZ SP IEEE ID CMOS; ENVIRONMENTS; ASSURANCE; IRRADIATION; TRANSISTORS; DEPENDENCE; ICS AB The radiation hardness of commercial Floating Gate 256K E(2)PROMs from a single diffusion lot was observed to vary between 5 to 25 krad(Si) when irradiated at a low dose rate of 64 mrad(Si)/s. Additional variations in E(2)PROM hardness were found to depend on bias condition and failure mode (i.e., inability to read or write the memory), as well as the foundry at which the part was manufactured. This variability is related to system requirements, and it is shown that hardness level and variability affect the allowable mode of operation for E(2)PROMs in space applications. The radiation hardness of commercial 1-Mbit CMOS SRAMs from Micron, Hitachi, and Sony irradiated at 147 rad(Si)/s was approximately 12, 13, and 19 krad(Si), respectively. These failure levels appear to be related to increases in leakage current during irradiation. Hardness of SRAMs from each manufacturer varied by less than 20%, but differences between manufacturers are significant. The Qualified Manufacturer's List approach to radiation hardness assurance is suggested as a way to reduce variability and to improve the hardness level of commercial technologies. RP SHANEYFELT, MR (reprint author), SANDIA NATL LABS,POB 5800,ALBUQUERQUE,NM 87185, USA. NR 20 TC 27 Z9 28 U1 0 U2 1 PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017-2394 SN 0018-9499 J9 IEEE T NUCL SCI JI IEEE Trans. Nucl. Sci. PD DEC PY 1994 VL 41 IS 6 BP 2536 EP 2543 DI 10.1109/23.340613 PN 1 PG 8 WC Engineering, Electrical & Electronic; Nuclear Science & Technology SC Engineering; Nuclear Science & Technology GA PZ157 UT WOS:A1994PZ15700102 ER PT J AU SHANEYFELT, MR FLEETWOOD, DM SCHWANK, JR MEISENHEIMER, TL WINOKUR, PS AF SHANEYFELT, MR FLEETWOOD, DM SCHWANK, JR MEISENHEIMER, TL WINOKUR, PS TI EFFECTS OF BURN-IN ON RADIATION HARDNESS SO IEEE TRANSACTIONS ON NUCLEAR SCIENCE LA English DT Article; Proceedings Paper CT 1994 IEEE Annual Conference on Nuclear and Space Radiation Effects (NSREC 94) CY JUL 18-22, 1994 CL TUCSON, AZ SP IEEE ID MOS DEVICES; ASSURANCE; TRANSISTORS; ICS AB Transistors and ICs were irradiated with or without pre-irradiation elevated-temperature biased stresses (i.e., burn-in). These stresses lead to larger radiation-induced transistor threshold-voltage shifts and increases in IC static power supply leakage current (two orders of; magnitude) in stressed ICs than for ICs not subjected to a stress. In addition, these stresses led to reduced degradation in timing parameters. The major cause of the differences is less radiation-induced interface-trap buildup for transistors subjected to an elevated-temperature biased stress. These results were observed for two distinctly different technologies and have significant implications on hardness assurance testing. One could significantly (1) overestimate degradation in timing parameters resulting in the rejection of acceptable ICs and increased system cost, or (2) underestimate the increase in static supply leakage current of ICs leading to system failure. These results suggest that radiation qualification testing must be performed on integrated circuits that have been subjected to all high-temperature biased stresses experienced in normal production flow or system use. RP SHANEYFELT, MR (reprint author), SANDIA NATL LABS,POB 5800,ALBUQUERQUE,NM 87185, USA. NR 24 TC 42 Z9 44 U1 0 U2 1 PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017-2394 SN 0018-9499 J9 IEEE T NUCL SCI JI IEEE Trans. Nucl. Sci. PD DEC PY 1994 VL 41 IS 6 BP 2550 EP 2559 DI 10.1109/23.340615 PN 1 PG 10 WC Engineering, Electrical & Electronic; Nuclear Science & Technology SC Engineering; Nuclear Science & Technology GA PZ157 UT WOS:A1994PZ15700104 ER PT J AU KHOSROPOUR, P FLEETWOOD, DM GALLOWAY, KF SCHRIMPF, RD CALVEL, P AF KHOSROPOUR, P FLEETWOOD, DM GALLOWAY, KF SCHRIMPF, RD CALVEL, P TI EVALUATION OF A METHOD FOR ESTIMATING LOW-DOSE-RATE IRRADIATION RESPONSE OF MOSFETS SO IEEE TRANSACTIONS ON NUCLEAR SCIENCE LA English DT Article; Proceedings Paper CT 1994 IEEE Annual Conference on Nuclear and Space Radiation Effects (NSREC 94) CY JUL 18-22, 1994 CL TUCSON, AZ SP IEEE ID HARDNESS ASSURANCE; SPACE ENVIRONMENTS; INTERFACE TRAPS; BORDER TRAPS; MOS DEVICES; MECHANISMS AB A simple method for estimating the threshold-voltage shift due to low-dose-rate ionizing irradiation was recently proposed for power MOSFETs. In this work, the physical considerations governing the applicability of the method are examined. In addition to the power MOSFETs discussed in the previous paper, the method is applied to integrated MOSFETs from two different technologies and critically evaluated. For this method to work, the oxide trapped charge due to low-dose-rate irradiation should be the same as that following irradiation at the dose rates specified in MIL-STD-883D Method 1019.4, and the interface-trap density following low-dose-rate irradiation should be the same as that following irradiation at 1019.4 rates and subsequent high-temperature annealing. Of the mio integrated technologies evaluated, the method correctly predicts the low-dose-rate threshold-voltage shift for one, but not for the other. In the case where the method yields the correct result, the agreement appears to be coincidental. The results, coupled with the necessity for transistor-level test structures, suggests that the proposed method is applicable primarily to power MOSFETs that exhibit slow annealing of oxide-trapped charge and no rebound during low-dose-rate irradiation. C1 SANDIA NATL LABS,ALBUQUERQUE,NM 87185. ALCATEL ESPACE,TOULOUSE,FRANCE. RP KHOSROPOUR, P (reprint author), UNIV ARIZONA,DEPT ELECT & COMP ENGN,TUCSON,AZ 85721, USA. RI Schrimpf, Ronald/L-5549-2013 OI Schrimpf, Ronald/0000-0001-7419-2701 NR 17 TC 13 Z9 14 U1 0 U2 1 PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017-2394 SN 0018-9499 J9 IEEE T NUCL SCI JI IEEE Trans. Nucl. Sci. PD DEC PY 1994 VL 41 IS 6 BP 2560 EP 2566 DI 10.1109/23.340616 PN 1 PG 7 WC Engineering, Electrical & Electronic; Nuclear Science & Technology SC Engineering; Nuclear Science & Technology GA PZ157 UT WOS:A1994PZ15700105 ER PT J AU PEASE, RL KOSIER, SL SCHRIMPF, RD COMBS, WE DAVEY, M DELAUS, M FLEETWOOD, DM AF PEASE, RL KOSIER, SL SCHRIMPF, RD COMBS, WE DAVEY, M DELAUS, M FLEETWOOD, DM TI COMPARISON OF HOT-CARRIER AND RADIATION-INDUCED INCREASES IN BASE CURRENT IN BIPOLAR-TRANSISTORS SO IEEE TRANSACTIONS ON NUCLEAR SCIENCE LA English DT Article; Proceedings Paper CT 1994 IEEE Annual Conference on Nuclear and Space Radiation Effects (NSREC 94) CY JUL 18-22, 1994 CL TUCSON, AZ SP IEEE ID DEVICES AB A comparison was made between hot-carrier-stress induced and ionizing-radiation induced increases in the base current of bipolar linear microcircuit transistors from two process technologies. The comparison was made on the basis of a failure stress in seconds and a failure dose in rad(SiO2) for a failure criterion of Delta I-B = 2 nA measured at an I-C of 1 mu A and V-CE of 5 V. Comparisons were made for several die on a single wafer, die from different wafers in a process lot, and die from split lots with various base oxide (also called spacer or screen oxide) hardening techniques applied. For each of these cases no correlation was found between stress-induced failure and ionizing-radiation induced failure. This result is consistent with modeling that shows different mechanisms for the degradation from hot-carriers and ionization. Hot-carrier stress induced damage is dominated by interface traps near the emitter-base junction periphery; whereas, ionizing-radiation induced damage is dominated by trapped positive charge in the base oxide over the extrinsic-base region. C1 UNIV ARIZONA,TUCSON,AZ. USN,CTR SURFACE WARFARE,CRANE,IN. SANDIA NATL LABS,ALBUQUERQUE,NM 87185. RP PEASE, RL (reprint author), RLP RES,ALBUQUERQUE,NM, USA. RI Schrimpf, Ronald/L-5549-2013 OI Schrimpf, Ronald/0000-0001-7419-2701 NR 16 TC 3 Z9 3 U1 0 U2 1 PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017-2394 SN 0018-9499 J9 IEEE T NUCL SCI JI IEEE Trans. Nucl. Sci. PD DEC PY 1994 VL 41 IS 6 BP 2567 EP 2573 DI 10.1109/23.340617 PN 1 PG 7 WC Engineering, Electrical & Electronic; Nuclear Science & Technology SC Engineering; Nuclear Science & Technology GA PZ157 UT WOS:A1994PZ15700106 ER PT J AU NOWLIN, RN FLEETWOOD, DM SCHRIMPF, RD AF NOWLIN, RN FLEETWOOD, DM SCHRIMPF, RD TI SATURATION OF THE DOSE-RATE RESPONSE OF BIPOLAR-TRANSISTORS BELOW 10-RAD(SIO2)/S - IMPLICATIONS FOR HARDNESS ASSURANCE SO IEEE TRANSACTIONS ON NUCLEAR SCIENCE LA English DT Article; Proceedings Paper CT 1994 IEEE Annual Conference on Nuclear and Space Radiation Effects (NSREC 94) CY JUL 18-22, 1994 CL TUCSON, AZ SP IEEE ID X-RAY; CO-60 IRRADIATIONS AB The gain degradation of modern bipolar transistors was investigated for dose rates ranging from 0.01 similar to 2000 rad(SiO2)/s; Five different radiation sources were used for the exposures: three Co-60 sources, a 10-keV x-ray source, and a Cs-137, source. The C-137 exposures at 0.01 rad(SiO2)/s are two orders of magnitude lower in dose rate than any previous irradiations for this process and thus facilitate comparison to the device response in space. Low-dose-rate gain degradation exceeds high-dose-rate degradation for total doses less than 1 Mrad(SiO2), consistent with previous reports. For the first time, the gain degradation is demonstrated to be equivalent for dose rates between 0.01 and 10 rad(SiO2)/s, suggesting that the dose-rate response saturates at similar to 10 rad(SiO2)/s for the devices studied in this work. On the basis of a recent model, high-dose-rate irradiations at 60 degrees C were performed and found to be consistent with the room-temperature, low-dose-rate, saturated response. These results suggest several promising new approaches to bipolar space-qualification testing. C1 SANDIA NATL LABS,DEPT 1332,ALBUQUERQUE,NM 87185. UNIV ARIZONA,DEPT ELECT & COMP ENGN,TUCSON,AZ 85721. RP NOWLIN, RN (reprint author), USAF,PHILLIPS LAB,MICROELECTR & PHOTON RES BRANCH,ALBUQUERQUE,NM 87117, USA. RI Schrimpf, Ronald/L-5549-2013 OI Schrimpf, Ronald/0000-0001-7419-2701 NR 14 TC 31 Z9 31 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 0018-9499 J9 IEEE T NUCL SCI JI IEEE Trans. Nucl. Sci. PD DEC PY 1994 VL 41 IS 6 BP 2637 EP 2641 DI 10.1109/23.340625 PN 1 PG 5 WC Engineering, Electrical & Electronic; Nuclear Science & Technology SC Engineering; Nuclear Science & Technology GA PZ157 UT WOS:A1994PZ15700115 ER PT J AU KIMBROUGH, JR COLELLA, NJ DENTON, SM SHAEFFER, DL SHIH, D WILBURN, JW COAKLEY, PG CASTENEDA, C KOGA, R CLARK, DA ULLMANN, JL AF KIMBROUGH, JR COLELLA, NJ DENTON, SM SHAEFFER, DL SHIH, D WILBURN, JW COAKLEY, PG CASTENEDA, C KOGA, R CLARK, DA ULLMANN, JL TI SINGLE EVENT EFFECTS AND PERFORMANCE PREDICTIONS FOR SPACE APPLICATIONS OF RISC PROCESSORS SO IEEE TRANSACTIONS ON NUCLEAR SCIENCE LA English DT Article ID SEU; UPSETS; ORBIT AB Proton and ion Single Event Phenomena (SEP) tests were performed on 32-b processors including R3000A's from all commercial manufacturers along with the Performance PR3400 family, Integrated Device Technology Inc. 79R3081, LSI Logic Corporation LR33000HC, and Intel i80960MX parts. The microprocessors had acceptable upset rates for operation in a low earth orbit or a lunar mission such as CLEMENTINE with a wide range in proton total dose failure. Even though R3000A devices are 60% smaller in physical area than R3000 devices, there was a 340% increase in device Single Event Upset (SEU) cross section. Software tests of varying complexity demonstrate that registers and other functional blocks using register architecture dominate the cross section. The current approach of giving a single upset cross section can lead to erroneous upset rates depending on the application software. C1 JAYCOR,SAN DIEGO,CA 92121. CROCKER NUCL LAB,DAVIS,CA 95616. AEROSP CORP,EL SEGUNDO,CA 90245. LOS ALAMOS NATL LAB,LOS ALAMOS,NM 87545. RP KIMBROUGH, JR (reprint author), LAWRENCE LIVERMORE NATL LAB,LIVERMORE,CA 94550, USA. NR 12 TC 2 Z9 2 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 0018-9499 J9 IEEE T NUCL SCI JI IEEE Trans. Nucl. Sci. PD DEC PY 1994 VL 41 IS 6 BP 2706 EP 2714 DI 10.1109/23.340637 PN 2 PG 9 WC Engineering, Electrical & Electronic; Nuclear Science & Technology SC Engineering; Nuclear Science & Technology GA PZ160 UT WOS:A1994PZ16000005 ER PT J AU SHAH, KS LUND, JC OLSCHNER, F ZHANG, J MOY, LP SQUILLANTE, MR MOSES, WW DERENZO, SE AF SHAH, KS LUND, JC OLSCHNER, F ZHANG, J MOY, LP SQUILLANTE, MR MOSES, WW DERENZO, SE TI TLBRXI1-X PHOTODETECTORS FOR SCINTILLATION SPECTROSCOPY SO IEEE TRANSACTIONS ON NUCLEAR SCIENCE LA English DT Article ID DETECTORS AB This paper reports on the evaluation of photodetectors fabricated from a ternary semiconductor, TlBrxI1-x for application in scintillation spectroscopy. These photodetectors are characterized in terms of their resistivity, charge transport parameters, quantum efficiency as a function of wavelength, and finally their performance as scintillation spectrometers. The details about TlBrxI1-x purification, crystal growth and device fabrication are also addressed. C1 UNIV CALIF BERKELEY,LAWRENCE BERKELEY LAB,BERKELEY,CA 94720. RP SHAH, KS (reprint author), RADIAT MONITORING DEVICES INC,WATERTOWN,MA 02172, USA. NR 13 TC 11 Z9 11 U1 0 U2 1 PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017-2394 SN 0018-9499 J9 IEEE T NUCL SCI JI IEEE Trans. Nucl. Sci. PD DEC PY 1994 VL 41 IS 6 BP 2715 EP 2718 DI 10.1109/23.340638 PN 2 PG 4 WC Engineering, Electrical & Electronic; Nuclear Science & Technology SC Engineering; Nuclear Science & Technology GA PZ160 UT WOS:A1994PZ16000006 ER PT J AU BEUTLER, DE HALBLEIB, JA SANFORD, TWL KNOTT, DP AF BEUTLER, DE HALBLEIB, JA SANFORD, TWL KNOTT, DP TI EXPERIMENTAL-VERIFICATION OF BREMSSTRAHLUNG PRODUCTION AND DOSIMETRY PREDICTIONS AS A FUNCTION OF ENERGY AND ANGLE SO IEEE TRANSACTIONS ON NUCLEAR SCIENCE LA English DT Article ID MEV ELECTRONS AB Measurements of energy deposition from bremsstrahlung production as a function of angle and beam energy (5-25 MeV) are shown to be in excellent agreement with Monte Carlo predictions. Dosimetry measurements are made and predicted in both equilibrated and underequilibrated radiation environments. In the latter ease the quality of the agreement requires an accurate prediction of both the photon and electron spectra produced by the primary electron beam. An improved empirical equation for predicting bremsstrahlung production is also presented. This empirical relation can be used to estimate doses without resorting to expensive calculational efforts, It also gives an analytical relationship for dose as a function of energy and angle for a converter optimized for bremsstrahlung production using 15.5 MeV electrons. C1 TECH SUPPORT CORP,ALBUQUERQUE,NM 87185. RP BEUTLER, DE (reprint author), SANDIA NATL LABS,ALBUQUERQUE,NM 87185, USA. NR 23 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 0018-9499 J9 IEEE T NUCL SCI JI IEEE Trans. Nucl. Sci. PD DEC PY 1994 VL 41 IS 6 BP 2727 EP 2736 DI 10.1109/23.340640 PN 2 PG 10 WC Engineering, Electrical & Electronic; Nuclear Science & Technology SC Engineering; Nuclear Science & Technology GA PZ160 UT WOS:A1994PZ16000008 ER PT J AU SCHEUER, JT SCHOENBERG, KF GERWIN, RA HOYT, RP HENINS, I BLACK, DC MAYO, RM MOSES, RW AF SCHEUER, JT SCHOENBERG, KF GERWIN, RA HOYT, RP HENINS, I BLACK, DC MAYO, RM MOSES, RW TI A MAGNETICALLY-NOZZLED, QUASI-STEADY, MULTIMEGAWATT, COAXIAL PLASMA THRUSTER SO IEEE TRANSACTIONS ON PLASMA SCIENCE LA English DT Article AB The Los Alamos National Laboratory Coaxial Thruster Experiment (CTX) has been upgraded to enable 10 ms quasi-steady-state (QSS) operation of magnetohydrodynamic type thrusters at power levels from 1 to 40 MW, Here we report on experimental observations and associated analysis for QSS discharges using deuterium, helium, and argon propellants, Measurements of thruster current and voltage, magnetic field fluctuations, electron density and temperature, and plasma potential indicate true quasi steady operation over 10 ms with propellant exhaust velocities of 1-2 x 10(5) m/s in helium and deuterium, The application of unique applied magnetic nozzle configurations result in a substantial reduction of the measured anode fall potential, Data analysis and analytical MHD modeling imply an impulsive start in the propellant flow that is limited to the Alfven critical ionization velocity and the presence of an effective constriction or ''nozzling'' in the flow channel, This research indicates that efficiency optimization of MHD class thrusters will most likely occur at megawatt power levels, This implies repetitively pulsed, high-power operation for near term, low-mean-power solar electric propulsion missions. C1 N CAROLINA STATE UNIV,DEPT NUCL ENGN,RALEIGH,NC 27695. RP SCHEUER, JT (reprint author), LOS ALAMOS NATL LAB,POB 1663,LOS ALAMOS,NM 87545, USA. NR 24 TC 16 Z9 16 U1 2 U2 4 PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017-2394 SN 0093-3813 J9 IEEE T PLASMA SCI JI IEEE Trans. Plasma Sci. PD DEC PY 1994 VL 22 IS 6 BP 1015 EP 1033 DI 10.1109/27.370254 PG 19 WC Physics, Fluids & Plasmas SC Physics GA QD343 UT WOS:A1994QD34300004 ER PT J AU GADGIL, AJ BONNEFOUS, YC FISK, WJ AF GADGIL, AJ BONNEFOUS, YC FISK, WJ TI RELATIVE EFFECTIVENESS OF SUB-SLAB PRESSURIZATION AND DEPRESSURIZATION SYSTEMS FOR INDOOR RADON MITIGATION - STUDIES WITH AN EXPERIMENTALLY VERIFIED NUMERICAL-MODEL SO INDOOR AIR LA English DT Article DE INDOOR RADON; SUB-SLAB VENTILATION; RADON MITIGATION; MODELING; ACTIVE SUBSLAB PRESSURIZATION; ACTIVE SUBSLAB DEPRESSURIZATION AB The performance of sub-slab-ventilation (SSV) systems has been parametrically studied with a numerical model that was earlier compared successfully with experiment (Bonnefous et al., 1992). The model distinguishes between the sub-slab gravel and the underlying soil. It is used to examine system performance for the following system parameters: the permeability of the soil and of the sub-slab gravel, the magnitude of pressurization (or depressurization) applied by the SSV system, and the mode of SSV application (i.e. pressurization (SSP) or depressurization (SSD)). The mechanisms contributing to the successful performance of SSP and SSD systems are identified. For SSD systems, the mechanisms are (1) the inversion of the pressure gradient across the basement slab, and (2) the reduction of the radon concentration in the soil. For SSP systems, the mechanisms are (1) the elimination of convective flow of soil-gas from the soil into the sub-slab gravel by pressurization of the sub-slab region, (2) the reduction of the radon concentration in the soil, and (3) the suppression of diffusion of soil-gas from the soil into the sub-slab gravel by advective flow of air from the gravel bed into the subgravel soil. Numerical modeling demonstrates that placement of a sub-slab gravel layer substantially improves the SSV system performance. Except in the case of highly permeable soils, SSD systems are predicted to perform better than SSP systems. This prediction is consistent with reported field experience. The numerical model is used to elucidate the reasons for this difference in performance. C1 GISE, ENPC, F-93167 NOISY LE GRAND, FRANCE. RP GADGIL, AJ (reprint author), LAWRENCE BERKELEY LAB, INDOOR ENVIRONM PROGRAM, 1 CYCLOTRON RD, BERKELEY, CA 94720 USA. NR 27 TC 6 Z9 6 U1 2 U2 9 PU WILEY-BLACKWELL PI HOBOKEN PA 111 RIVER ST, HOBOKEN 07030-5774, NJ USA SN 0905-6947 EI 1600-0668 J9 INDOOR AIR JI Indoor Air PD DEC PY 1994 VL 4 IS 4 BP 265 EP 275 DI 10.1111/j.1600-0668.1994.00007.x PG 11 WC Construction & Building Technology; Engineering, Environmental; Public, Environmental & Occupational Health SC Construction & Building Technology; Engineering; Public, Environmental & Occupational Health GA QC408 UT WOS:A1994QC40800007 ER PT J AU TUNG, LA KING, CJ AF TUNG, LA KING, CJ TI SORPTION AND EXTRACTION OF LACTIC AND SUCCINIC ACIDS AT PH-GREATER-THAN-PK(A1) .1. FACTORS GOVERNING EQUILIBRIA SO INDUSTRIAL & ENGINEERING CHEMISTRY RESEARCH LA English DT Article ID CARBOXYLIC-ACIDS; AMINE EXTRACTANTS; FERMENTATION AB Many fermentations to produce carboxylic acids operate most effectively at pH above pK(a1) of the acid product, under which conditions the acid is largely in the carboxylate form. One approach to acid recovery from such solutions is to use solid sorbents or liquid extractants that are strongly enough basic to provide substantial capacity even at moderately high values of pH. Data are presented for sorption of lactic and succinic acids by several commercially available basic polymeric sorbents. Performance at pH > pK(a1) is a function of sorbent basicity, and apparent pK(a) or monomer pK(a) can be used to predict sorbent performance. Data are also presented for the extraction of the acids by two commercial amine extractants, Alamine 336 and Amberlite LA-2, in various diluents. The extractants sustain capacity to higher pH in diluents that stabilize the acid-amine complex. Secondary amines provide higher capacities than do tertiary amines in diluents that solvate the additional proton. Competitive uptakes of sulfate, phosphate, and carboxylate were also measured. C1 UNIV CALIF BERKELEY,DEPT CHEM ENGN,BERKELEY,CA 94720. UNIV CALIF BERKELEY,LAWRENCE BERKELEY LAB,BERKELEY,CA 94720. NR 29 TC 87 Z9 90 U1 3 U2 13 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 DEC PY 1994 VL 33 IS 12 BP 3217 EP 3223 DI 10.1021/ie00036a041 PG 7 WC Engineering, Chemical SC Engineering GA PW086 UT WOS:A1994PW08600042 ER PT J AU TUNG, LA KING, CJ AF TUNG, LA KING, CJ TI SORPTION AND EXTRACTION OF LACTIC AND SUCCINIC ACIDS AT PH-GREATER-THAN-PK(A1) .2. REGENERATION AND PROCESS CONSIDERATIONS SO INDUSTRIAL & ENGINEERING CHEMISTRY RESEARCH LA English DT Article AB As shown in part 1, carboxylic acids can be recovered from solutions at pH > pK(a1) of the, acid by solid sorbents or liquid extractants that are sufficiently basic to maintain substantial capacities even at moderately high values of pH. Appropriate extractants and sorbents can be regenerated by back-extracting the acid into aqueous trimethylamine (TMA) solution, followed by thermal decomposition of the resulting trimethylammonium (TMAm) carboxylate. Polymeric sorbents and liquid extractants with tertiary amine functionalities are completely regenerable by leaching with aqueous TMA solutions. Fixed-bed breakthrough curves for the sorbent Dowex MWA-1 in both the uptake and regeneration modes are self-sharpening, and the regeneration curve displays a focusing effect. For acids having low-to-moderate solubilities thermal cracking of the resultant TMAm carboxylate yields acid crystals and trimethylamine vapor for recycle. Because lactic acid is more soluble and tends to self-esterify, simple cracking gives only partial regeneration. Another approach is to react TMAm lactate with an alcohol to form the ester and TMA for recycle. The feasibility of this approach was demonstrated through laboratory-scale experiments with n-butanol. C1 UNIV CALIF BERKELEY,DEPT CHEM ENGN,BERKELEY,CA 94720. UNIV CALIF BERKELEY,LAWRENCE BERKELEY LAB,BERKELEY,CA 94720. NR 18 TC 12 Z9 12 U1 2 U2 10 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 DEC PY 1994 VL 33 IS 12 BP 3224 EP 3229 DI 10.1021/ie00036a042 PG 6 WC Engineering, Chemical SC Engineering GA PW086 UT WOS:A1994PW08600043 ER PT J AU BROEKHUIS, RR LYNN, S KING, CJ AF BROEKHUIS, RR LYNN, S KING, CJ TI RECOVERY OF PROPYLENE-GLYCOL FROM DILUTE AQUEOUS-SOLUTIONS VIA REVERSIBLE-REACTION WITH ALDEHYDES SO INDUSTRIAL & ENGINEERING CHEMISTRY RESEARCH LA English DT Article AB The recovery of propylene glycol from dilute aqueous solutions via reaction with formaldehyde to form 4-methyl-1,3-dioxolane or with acetaldehyde to form 2,4-dimethyl-1,3-dioxolane was studied experimentally. The equilibrium and kinetics of the reaction with formaldehyde were studied in systems catalyzed by Amberlite IR-120 ion exchange resin. The equilibrium constant ranged from 5.9 to 8.7 in the temperature range from 25 to 85 degrees C, with no obvious trend with respect to temperature. The kinetics was found to be first-order in the concentrations of propylene glycol, formaldehyde, and Amberlite IR-120, with an activation energy of 102 kJ/mol. In the reaction with acetaldehyde, the equilibrium constant decreased from 18.1 at 40 degrees C to 8.5 at 83 degrees C. The kinetics was faster than with formaldehyde. The volatilities of 4-methyl-1,3-dioxolane and 2,4-dimethyl-1,3-dioxolane relative to water were 100 and 33, respectively. Of several solvents screened, aromatic hydrocarbons exhibited the highest distribution of 2,4-dimethyl-1,3-dioxolane from the aqueous into the organic phase. Recovery of propylene glycol by reactive distillation with formaldehyde or acetaldehyde is hampered by unfavorable chemical and phase equilibria. A process combining reaction and extraction into an organic solvent appears to be more attractive and substantially reduces the energy requirement, in comparison with a triple-effect evaporation process. C1 UNIV CALIF BERKELEY,DEPT CHEM ENGN,BERKELEY,CA 94720. UNIV CALIF BERKELEY,LAWRENCE BERKELEY LAB,BERKELEY,CA 94720. NR 14 TC 30 Z9 35 U1 1 U2 3 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 DEC PY 1994 VL 33 IS 12 BP 3230 EP 3237 DI 10.1021/ie00036a043 PG 8 WC Engineering, Chemical SC Engineering GA PW086 UT WOS:A1994PW08600044 ER PT J AU BEEMAN, JW HALLER, EE AF BEEMAN, JW HALLER, EE TI GE-GA PHOTOCONDUCTOR ARRAYS - DESIGN CONSIDERATIONS AND QUANTITATIVE-ANALYSIS OF PROTOTYPE SINGLE PIXELS SO INFRARED PHYSICS & TECHNOLOGY LA English DT Article ID GERMANIUM AB We have conducted a series of experiments on Ge:Ga photoconductors to quantitatively understand how monolithic two-dimensional arrays of this material will perform. Various single pixel prototypes were built and tested in terms of responsivity and detective quantum efficiency, and the results are plotted and compared with the expected absorption efficiency for these devices. All tests were conducted at 89.9 pm wavelength (bandwidth = 11.9 mu m), using standard transimpedence amplifiers and low background conditions. The best performance was obtained for a 2 mm long ''longitudinally-contacted'' detector that was not mounted inside of an integrating cavity: responsivity = 5.2 A/W, and detective quantum efficiency = 7.7%. The configuration of this device is easily expanded into a two-dimensional format. C1 UNIV CALIF BERKELEY,BERKELEY,CA 94720. RP BEEMAN, JW (reprint author), UNIV CALIF BERKELEY,LAWRENCE BERKELEY LAB,BERKELEY,CA 94720, USA. NR 14 TC 21 Z9 21 U1 1 U2 1 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD, ENGLAND OX5 1GB SN 1350-4495 J9 INFRARED PHYS TECHN JI Infrared Phys. Technol. PD DEC PY 1994 VL 35 IS 7 BP 827 EP 836 DI 10.1016/1350-4495(94)90048-5 PG 10 WC Instruments & Instrumentation; Optics; Physics, Applied SC Instruments & Instrumentation; Optics; Physics GA PW078 UT WOS:A1994PW07800001 ER PT J AU DELMORE, JE APPELHANS, AD OLSON, JE AF DELMORE, JE APPELHANS, AD OLSON, JE TI SELF IMAGING OF SURFACE-IONIZATION ION SOURCES - WHERE DO THE IONS COME FROM SO INTERNATIONAL JOURNAL OF MASS SPECTROMETRY AND ION PROCESSES LA English DT Article DE ION SOURCES; SURFACE IONIZATION; IMAGING; ION OPTICS; PREFORMED IONS ID GUN AB Images of the ion emitting regions of solid state ion sources have been produced using the ions emitted from the sources during operation to help elucidate the chemistry and physics of surface ionization. Examples are presented of a ceramic negative ion source producing perrhenate anions and of a zeolite ion source producing cesium cations, both of which are used as ion emitters in SIMS guns. In both cases it is shown that the ions originate from the surface of the ceramic or zeolite matrix, and not from interfacial regions between the matrix and the metal support structure. It is argued that for these two systems the gas phase ions are formed predominantly by direct sublimation of preformed ions from the hot surface of the matrix, due to the established fact that the ions observed in the gas phase are also known to exist in the solid, while it is improbable that the neutral species exist in the solid in appreciable concentrations. It is further shown that conventional surface ionization filament designs introduce asymmetric voltage gradients in the ion lens, leading to a loss in focusing. This can be corrected by using an indirectly heated ion source that has no voltage gradient across the face of the ion emitting region. RP DELMORE, JE (reprint author), IDAHO NATL ENGN LAB,IDAHO FALLS,ID 83415, USA. RI Garcia-Sanchez, Almudena/B-3303-2009 NR 10 TC 9 Z9 9 U1 0 U2 3 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0168-1176 J9 INT J MASS SPECTROM JI Int. J. Mass Spectom. Ion Process. PD DEC PY 1994 VL 140 BP 111 EP 122 DI 10.1016/0168-1176(94)04089-3 PG 12 WC Physics, Atomic, Molecular & Chemical; Spectroscopy SC Physics; Spectroscopy GA QA315 UT WOS:A1994QA31500002 ER PT J AU BROOKS, AL KHAN, MA DUNCAN, A BUSCHBOM, RL JOSTES, RF CROSS, FT AF BROOKS, AL KHAN, MA DUNCAN, A BUSCHBOM, RL JOSTES, RF CROSS, FT TI EFFECTIVENESS OF RADON RELATIVE TO ACUTE CO-60 GAMMA-RAYS FOR INDUCTION OF MICRONUCLEI IN-VITRO AND IN-VIVO SO INTERNATIONAL JOURNAL OF RADIATION BIOLOGY LA English DT Article ID HUMAN CHROMOSOME ABERRATIONS; HUMAN-LYMPHOCYTES; DOSE-RATE; ONCOGENIC TRANSFORMATION; BIOLOGICAL EFFECTIVENESS; ALPHA-PARTICLES; GENE-MUTATIONS; IN-VITRO; RADIATION; IRRADIATION AB Because radon and its progeny (referred to collectively here as radon) emit alpha particles with a wide range of energies, as well as beta particles and gamma-rays, it is important to quantitate the relationship between initial damage induced by radon and that by acute low-LET radiation. We have evaluated dose-response relationships for induction of micronuclei both in vivo and in vitro following exposure to radon or Co-60. TO determine if isolation procedures altered the cells' responsiveness to Co-60 gamma-ray exposures, animals were exposed before cell isolation, or cells were isolated and then exposed. The data were described by linear dose-response functions and were not significantly different when the radiation exposure was in vivo or in vitro (respectively micronuclei/1000 binucleated cells = 1.6+/-65+62+/-2.7 D; micronuclei/1000 binucleated cells=15.4+/-26.0+54.6+/-11.4 D, where D is in Gy). Primary rat lung fibroblasts (RLF) or Chinese hamster ovary (CHO-Kl) cells were exposed in vitro to either radon or Co-60 gamma-rays. Radon was 10(-9)+/-2.6 and 12.5+/-2.4 times as effective per Gy of radiation dose in producing micronuclei as was Co-60 in RLF and CHO-Kl cells respectively. To determine the relative biological effectiveness of in vivo radon exposure, animals were exposed to either radon or Co-60, and lung fibroblasts were isolated and evaluated for radiation-induced micronuclei. In vivo radon exposure was 10.6+/-1.0 times as effective as acute whole-body Co-60 exposure in producing micronuclei in lung fibroblasts. Different cell lines and exposure conditions resulted in similar effectiveness factors. Such ratios help evaluate the biological damage, hazard and risk associated with radon inhalation. RP BROOKS, AL (reprint author), PACIFIC NW LAB, P7-53, RICHLAND, WA 99352 USA. NR 46 TC 24 Z9 26 U1 0 U2 0 PU TAYLOR & FRANCIS LTD LONDON PI LONDON PA ONE GUNDPOWDER SQUARE, LONDON, ENGLAND EC4A 3DE SN 0955-3002 J9 INT J RADIAT BIOL JI Int. J. Radiat. Biol. PD DEC PY 1994 VL 66 IS 6 BP 801 EP 808 PG 8 WC Biology; Nuclear Science & Technology; Radiology, Nuclear Medicine & Medical Imaging SC Life Sciences & Biomedicine - Other Topics; Nuclear Science & Technology; Radiology, Nuclear Medicine & Medical Imaging GA QB105 UT WOS:A1994QB10500016 PM 7814979 ER PT J AU DOWLEY, LJ SULLIVAN, E AF DOWLEY, LJ SULLIVAN, E TI THE EFFECT OF PHENYLAMIDE MANCOZEB MIXTURES ON THE CONTROL OF LATE BLIGHT OF POTATOES SO IRISH JOURNAL OF AGRICULTURAL AND FOOD RESEARCH LA English DT Article DE FUNGICIDE MIXTURES; LATE BLIGHT; POTATOES AB Field experiments were conducted from 1986 to 1992 to determine the effectiveness of spray programmes using phenylamide/mancozeb mixtures in controlling late blight of potatoes. These mixtures were used as the first three sprays in a 10-spray programme, with the remaining sprays being of mancozeb. Compared with mancozeb alone, phenylamide/mancozeb mixtures resulted in a significant delay in disease onset in 6 of the 7 years of the experiments while the level of foliage blight at the end of the season was significantly lower in 5 years. Total and marketable yields were significantly higher and tuber blight levels after storage were significantly reduced in 3 of the years. The effect on yield was greatest when disease pressure was highest. Phenylamide-resistant inoculum was present in the trial area in all 7 years of the study. RP DOWLEY, LJ (reprint author), TEAGASC,OAK PK RES CTR,CARLOW,IRELAND. NR 0 TC 1 Z9 1 U1 0 U2 0 PU TEAGASC PI DUBLIN PA 19 SANDYMOUNT AVE, DUBLIN 4, IRELAND SN 0791-6833 J9 IRISH J AGR FOOD RES JI Irish J. Agr. Food Res. PD DEC PY 1994 VL 33 IS 2 BP 177 EP 181 PG 5 WC Agriculture, Multidisciplinary; Food Science & Technology SC Agriculture; Food Science & Technology GA QC410 UT WOS:A1994QC41000008 ER PT J AU CRILLY, J AF CRILLY, J TI DRUG LICENSING - AN EXPENSIVE AND UNNECESSARY MANIFESTATION OF SUBSIDIARITY SO IRISH VETERINARY JOURNAL LA English DT Editorial Material RP CRILLY, J (reprint author), TEAGASC,AGR & FOOD DEV AUTHOR,19 SANDYMOUNT AVE,DUBLIN 4,IRELAND. NR 0 TC 0 Z9 0 U1 0 U2 0 PU IRISH VETERINARY ASSN PI DUBLIN PA 53 LANSDOWNE RD, DUBLIN 4, IRELAND SN 0368-0762 J9 IRISH VET J JI Irish Vet. J. PD DEC PY 1994 VL 47 IS 8 BP 384 EP 384 PG 1 WC Veterinary Sciences SC Veterinary Sciences GA QA320 UT WOS:A1994QA32000009 ER PT J AU HECKER, SS AF HECKER, SS TI RETOOLING THE FEDERAL LABS SO ISSUES IN SCIENCE AND TECHNOLOGY LA English DT Letter RP HECKER, SS (reprint author), LOS ALAMOS NATL LAB,LOS ALAMOS,NM 87544, USA. NR 0 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 WIN PY 1994 VL 10 IS 2 BP 7 EP 8 PG 2 WC Engineering, Multidisciplinary; Engineering, Industrial; Multidisciplinary Sciences; Social Issues SC Engineering; Science & Technology - Other Topics; Social Issues GA MQ255 UT WOS:A1994MQ25500005 ER PT J AU SCHRIESHEIM, A AF SCHRIESHEIM, A TI RETOOLING THE FEDERAL LABS SO ISSUES IN SCIENCE AND TECHNOLOGY LA English DT Letter RP SCHRIESHEIM, A (reprint author), ARGONNE NATL LAB,ARGONNE,IL 60439, 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 WIN PY 1994 VL 10 IS 2 BP 7 EP 7 PG 1 WC Engineering, Multidisciplinary; Engineering, Industrial; Multidisciplinary Sciences; Social Issues SC Engineering; Science & Technology - Other Topics; Social Issues GA MQ255 UT WOS:A1994MQ25500004 ER PT J AU GOYAL, A AF GOYAL, A TI ADVANCES IN PROCESSING HIGH-T-C SUPERCONDUCTORS FOR BULK APPLICATIONS SO JOM-JOURNAL OF THE MINERALS METALS & MATERIALS SOCIETY LA English DT Editorial Material RP GOYAL, A (reprint author), OAK RIDGE NATL LAB,POB 2008,OAK RIDGE,TN, USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU MINERALS METALS MATERIALS SOC PI WARRENDALE PA 420 COMMONWEALTH DR, WARRENDALE, PA 15086 SN 1047-4838 J9 JOM-J MIN MET MAT S JI JOM-J. Miner. Met. Mater. Soc. PD DEC PY 1994 VL 46 IS 12 BP 11 EP 11 PG 1 WC Materials Science, Multidisciplinary; Metallurgy & Metallurgical Engineering; Mineralogy; Mining & Mineral Processing SC Materials Science; Metallurgy & Metallurgical Engineering; Mineralogy; Mining & Mineral Processing GA QU356 UT WOS:A1994QU35600002 ER PT J AU KROEGER, DM GOYAL, A AF KROEGER, DM GOYAL, A TI MODELS FOR LONG-RANGE CURRENT FLOW IN BULK OXIDE SUPERCONDUCTORS SO JOM-JOURNAL OF THE MINERALS METALS & MATERIALS SOCIETY LA English DT Article ID GRAIN-BOUNDARY COMPOSITIONS; CRITICAL CURRENT-DENSITY; SILVER-SHEATHED TAPES; TRANSPORT-PROPERTIES; TC PHASE; BEHAVIOR; WIRES; FILMS AB Mitigating the weak-link behavior at grain boundaries, which limits critical current density (J(c)) in polycrystalline high-transition-temperature (high-T-c) superconducting materials, is required for all applications in magnetic fields. Although in general oxide superconductors in polycrystalline form have very poor in-field J(c), conductors containing the bismuth-based compounds Bi2Sr2CaCu2O8 (Bi-2212) and Bi2Sr2Ca2Cu3O10 (Bi-2223) are very important exceptions. Long-range, strongly linked conduction has been demonstrated in just two additional polycrystalline materials: TlBa2Ca2Cu3O10 (Tl-1223) deposits prepared by spray pyrolysis, and YBa2Cu4O8 (Y-124) conductor made by the oxidation of metallic precursor method. Determining the characteristics of these materials that permit strongly linked conduction is of critical importance to the development of better conductors. Models of strongly linked polycrystalline conductors are reviewed. Recent studies reveal that small-angle boundaries are present in much higher numbers than expected from calculations based on macroscopic texture, indicating a strong influence of grain boundary energy. It is proposed that strongly linked current flows through a connected network of low energy grain boundaries. Evidence has been obtained to support this model in Bi-2223, Y-124 and Tl-1223. C1 OAK RIDGE NATL LAB,DIV MET & CERAM,OAK RIDGE,TN 37831. NR 43 TC 4 Z9 4 U1 1 U2 1 PU MINERALS METALS MATERIALS SOC PI WARRENDALE PA 420 COMMONWEALTH DR, WARRENDALE, PA 15086 SN 1047-4838 J9 JOM-J MIN MET MAT S JI JOM-J. Miner. Met. Mater. Soc. PD DEC PY 1994 VL 46 IS 12 BP 14 EP 19 PG 6 WC Materials Science, Multidisciplinary; Metallurgy & Metallurgical Engineering; Mineralogy; Mining & Mineral Processing SC Materials Science; Metallurgy & Metallurgical Engineering; Mineralogy; Mining & Mineral Processing GA QU356 UT WOS:A1994QU35600003 ER PT J AU BALACHANDRAN, U IYER, AN HUANG, JY JAMMY, R HALDAR, P HOEHN, JG GALINSKI, G MOTOWIDLO, LR AF BALACHANDRAN, U IYER, AN HUANG, JY JAMMY, R HALDAR, P HOEHN, JG GALINSKI, G MOTOWIDLO, LR TI RECENT ADVANCES IN BISMUTH-BASED SUPERCONDUCTORS SO JOM-JOURNAL OF THE MINERALS METALS & MATERIALS SOCIETY LA English DT Article ID CA-CU-O; CRITICAL-CURRENT-DENSITY; SINGLE-PHASE; BI; WIRES; TAPES; PB; BI-2223; SYSTEM AB Significant progress has been made in the development of high-critical-temperature (high-T-c) mono- and multifilament bismuth-based superconductors by the powder-in-tube (PIT) technique. High critical current density (J(c)) has been achieved in both short- and long-length monofilament conductors. J(c)s up to 1.2 x 10(4) A/cm(2) were achieved in an 850 m long multifilament conductor. Pancake-shaped coils and test magnets, fabricated from long conductors, were characterized at various temperatures and applied magnetic fields. One such magnet containing 480 m of high-T-c tape generated a record-high field of 2.6 T at 4.2 K. Multifilament conductors appear to possess better mechanical properties and retain a higher percentage of their initial critical current under strain than monocore conductors, which is important for practical considerations. PIT processing of superconducting tapes with AgAl2O3 as the sheath material is perhaps another route to improve mechanical properties. C1 ARGONNE NATL LAB, IIT, ARGONNE, IL 60439 USA. ARGONNE NATL LAB, NORTHWESTERN UNIV, ARGONNE, IL 60439 USA. INTERMAGNET GEN CORP, ADV SUPERCONDUCTORS, GUILDERLAND, NY 12084 USA. RP ARGONNE NATL LAB, CERAM SECT, 9700 S CASS AVE, 212-G242, ARGONNE, IL 60439 USA. NR 40 TC 20 Z9 20 U1 1 U2 6 PU MINERALS METALS MATERIALS SOC PI WARRENDALE PA 184 THORN HILL RD, WARRENDALE, PA 15086 USA SN 1047-4838 J9 JOM-J MIN MET MAT S JI JOM-J. Miner. Met. Mater. Soc. PD DEC PY 1994 VL 46 IS 12 BP 23 EP 25 PG 3 WC Materials Science, Multidisciplinary; Metallurgy & Metallurgical Engineering; Mineralogy; Mining & Mineral Processing SC Materials Science; Metallurgy & Metallurgical Engineering; Mineralogy; Mining & Mineral Processing GA QU356 UT WOS:A1994QU35600005 ER PT J AU MASUR, LJ PODTBURG, ER CRAVEN, CA OTTO, A WANG, ZL KROEGER, DM AF MASUR, LJ PODTBURG, ER CRAVEN, CA OTTO, A WANG, ZL KROEGER, DM TI ADVANCES IN THE PROCESSING AND PROPERTIES OF YBA2CU4O8 SO JOM-JOURNAL OF THE MINERALS METALS & MATERIALS SOCIETY LA English DT Article ID WIRES AB High-filament-count, silver-sheathed composite wires of YBa2Cu4O8 were prepared by a metallic precursor route. The ductility of the metallic precursor enabled the manufacture of tapes containing up to 962,407 filaments, with filament dimensions as fine as 0.25 mu m thick and 1 mu m wide. The combination of thermal-mechanical treatment and fine filament dimensions resulted in significant biaxial crystallographic texture. Transport critical current densities in the oxide filaments rts of 69.5 kA/cm(2) at 4.2 K in self-field with reduced weak-link behavior in an applied field were obtained. Critical current retention during bending was shown to increase as filament count increased, with the highest filament-count mate ria I showing close to one percent critical bending strain. These wires exhibited some of the best properties for a polycrystalline, sintered wire of YBCO in an applied magnetic field. C1 NATL INST STAND & TECHNOL,BOULDER,CO 80303. OAK RIDGE NATL LAB,OAK RIDGE,TN 37831. RP MASUR, LJ (reprint author), AMER SUPERCONDUCTOR CORP,RES & DEV,2 TECHNOL DR,WESTBOROUGH,MA 01581, USA. RI Wang, Zhong Lin/E-2176-2011 OI Wang, Zhong Lin/0000-0002-5530-0380 NR 16 TC 7 Z9 7 U1 0 U2 0 PU MINERALS METALS MATERIALS SOC PI WARRENDALE PA 420 COMMONWEALTH DR, WARRENDALE, PA 15086 SN 1047-4838 J9 JOM-J MIN MET MAT S JI JOM-J. Miner. Met. Mater. Soc. PD DEC PY 1994 VL 46 IS 12 BP 28 EP 30 PG 3 WC Materials Science, Multidisciplinary; Metallurgy & Metallurgical Engineering; Mineralogy; Mining & Mineral Processing SC Materials Science; Metallurgy & Metallurgical Engineering; Mineralogy; Mining & Mineral Processing GA QU356 UT WOS:A1994QU35600007 ER PT J AU GREVE, LC SHACKEL, KA AHMADI, H MCARDLE, RN GOHLKE, JR LABAVITCH, JM AF GREVE, LC SHACKEL, KA AHMADI, H MCARDLE, RN GOHLKE, JR LABAVITCH, JM TI IMPACT OF HEATING ON CARROT FIRMNESS - CONTRIBUTION OF CELLULAR TURGOR SO JOURNAL OF AGRICULTURAL AND FOOD CHEMISTRY LA English DT Article DE TEXTURE; CARROT; TURGOR; PLASMOLYSIS AB The firmness of carrot root disks mas measured after various periods oi heating in boiling water. Tissues lost more than half of their initial firmness within a few minutes. A second, much slower, phase of firmness loss continued for 10-15 min. The early phase of firmness loss could be mimicked by plasmolyzing carrot tissues in mannitol solution, and plasmolyzed disks showed only the second, slower, phase of firmness loss during cooking. Measurements of cellular turgor (turgor pressure probe) and membrane integrity (vital dye) indicate that turgor and membrane function are quickly lost during heating. When disks were incubated in a range of mannitol solutions, tissue firmness and cell turgor were linearly related. C1 LAWRENCE LIVERMORE NATL LAB,DEPT POMOL,DAVIS,CA 95616. NR 10 TC 103 Z9 107 U1 1 U2 7 PU AMER CHEMICAL SOC PI WASHINGTON PA PO BOX 57136, WASHINGTON, DC 20037-0136 SN 0021-8561 J9 J AGR FOOD CHEM JI J. Agric. Food Chem. PD DEC PY 1994 VL 42 IS 12 BP 2896 EP 2899 DI 10.1021/jf00048a047 PG 4 WC Agriculture, Multidisciplinary; Chemistry, Applied; Food Science & Technology SC Agriculture; Chemistry; Food Science & Technology GA PY231 UT WOS:A1994PY23100047 ER PT J AU GREVE, LC MCARDLE, RN GOHLKE, JR LABAVITCH, JM AF GREVE, LC MCARDLE, RN GOHLKE, JR LABAVITCH, JM TI IMPACT OF HEATING ON CARROT FIRMNESS - CHANGES IN CELL-WALL COMPONENTS SO JOURNAL OF AGRICULTURAL AND FOOD CHEMISTRY LA English DT Article DE CARROT; PECTIN; TEXTURE; BETA-ELIMINATION ID PECTIC SUBSTANCES; DEGRADATION; FRACTIONS AB The impact of heating in boiling water on tissue firmness retention of the carrot genotypes Danvers and B9304 was measured. Both genotypes showed a rapid early loss in firmness that was followed by a slower, more prolonged, softening. Softening was greater in Danvers carrots. Cell wall carbohydrate compositions of the two varieties were similar, but wall component dissolution (solubilization and depolymerization) was more extensive in Danvers. The breakdown of soluble and wall-bound pectins involved beta-elimination reactions. A survey of several carrot genotypes indicated that those carrots with chelator-soluble pectins of relatively lower molecular weight tended to soften more extensively during heating. C1 LAWRENCE LIVERMORE NATL LAB,DEPT POMOL,DAVIS,CA 95616. NR 21 TC 91 Z9 94 U1 0 U2 13 PU AMER CHEMICAL SOC PI WASHINGTON PA PO BOX 57136, WASHINGTON, DC 20037-0136 SN 0021-8561 J9 J AGR FOOD CHEM JI J. Agric. Food Chem. PD DEC PY 1994 VL 42 IS 12 BP 2900 EP 2906 DI 10.1021/jf00048a048 PG 7 WC Agriculture, Multidisciplinary; Chemistry, Applied; Food Science & Technology SC Agriculture; Chemistry; Food Science & Technology GA PY231 UT WOS:A1994PY23100048 ER PT J AU SCHEWEMILLER, IM YOUNG, VG AF SCHEWEMILLER, IM YOUNG, VG TI HF2SE3, A NEW STRUCTURE IN THE BINARY HF-SE SYSTEM SO JOURNAL OF ALLOYS AND COMPOUNDS LA English DT Article DE HAFNIUM; SELENIUM AB Hf2Se3 was synthesized and its structure determined using the Rietveld method with X-ray powder diffraction data (Ti5S8 type, space group: P6(3)mc, a = 3.7165(1) Angstrom, c = 12.4304(2) Angstrom, Z = 2 for Hf1.35Se2, Rp = 0.0600, wRp = 0.0811). The Se atoms form a closed packed array of the h.c. type, the Hf atoms occupy octahedral interstices in alternating fully and 35% occupied layers. C1 IOWA STATE UNIV SCI & TECHNOL,DEPT CHEM,AMES,IA 50011. RP SCHEWEMILLER, IM (reprint author), IOWA STATE UNIV SCI & TECHNOL,INST PHYS RES & TECHNOL,AMES,IA 50011, USA. NR 8 TC 11 Z9 11 U1 0 U2 0 PU ELSEVIER SCIENCE SA LAUSANNE PI LAUSANNE 1 PA PO BOX 564, 1001 LAUSANNE 1, SWITZERLAND SN 0925-8388 J9 J ALLOY COMPD JI J. Alloy. Compd. PD DEC PY 1994 VL 216 IS 1 BP 113 EP 115 DI 10.1016/0925-8388(94)91051-0 PG 3 WC Chemistry, Physical; Materials Science, Multidisciplinary; Metallurgy & Metallurgical Engineering SC Chemistry; Materials Science; Metallurgy & Metallurgical Engineering GA QA067 UT WOS:A1994QA06700026 ER PT J AU COOLING, BF AF COOLING, BF TI FROM CAPE-CHARLES TO CAPE-FEAR - THE NORTH-ATLANTIC BLOCKADING SQUADRON DURING THE CIVIL-WAR - BROWNING,RM SO JOURNAL OF AMERICAN HISTORY LA English DT Book Review RP COOLING, BF (reprint author), US DOE,WASHINGTON,DC, USA. NR 1 TC 0 Z9 0 U1 0 U2 0 PU ORGAN AMER HISTORIANS PI BLOOMINGTON PA 112 N BRYAN ST, BLOOMINGTON, IN 47401 SN 0021-8723 J9 J AM HIST JI J. Am. Hist. PD DEC PY 1994 VL 81 IS 3 BP 1318 EP 1318 DI 10.2307/2081532 PG 1 WC History SC History GA PX811 UT WOS:A1994PX81100095 ER PT J AU AGBLEVOR, FA EVANS, RJ JOHNSON, KD AF AGBLEVOR, FA EVANS, RJ JOHNSON, KD TI MOLECULAR-BEAM MASS-SPECTROMETRIC ANALYSIS OF LIGNOCELLULOSIC MATERIALS .1. HERBACEOUS BIOMASS SO JOURNAL OF ANALYTICAL AND APPLIED PYROLYSIS LA English DT Article DE BIOMASS; KLASON LIGNIN ANALYSIS; MOLECULAR-BEAM MASS SPECTROMETRY; PYROLYSIS ID COMPONENT SPECTRA; PYROLYSIS; ENERGY AB A rapid analytical technique has been developed to qualitatively screen and quantitatively analyze biomass feedstocks for conversion into hydrocarbon fuels and chemicals. In this rapid analytical pyrolysis approach, herbaceous biomass feedstocks stored in the open without cover for 6 to 9 months were characterized using the molecular-beam mass spectrometer (MBMS). The biomass materials were pyrolyzed at 600 degrees C and the volatile pyrolysis products were analyzed in real time by the MBMS. The mass spectral data were further analyzed by multivariate statistical techniques (Factor Analysis). The contents of nitrogen compounds, pentosans and hexosans estimated from the pyrolysis mass-spectrometric/multivariate analysis techniques correlated well with the results obtained by conventional wet chemical methods. However, lignin correlation was very weak because of the presence of microbial degradation products of biomass (humic material) that interfered with the Klason lignin analysis. This rapid analytical technique was used to analyze various fractions of the stored biomass feedstocks. A comparison of exposed surface biomass materials and the unexposed materials showed that the exposed fraction lost 30% (wt) of the carbohydrate component of the biomass relative to the fresh material. C1 PURDUE UNIV,DEPT AGRON,W LAFAYETTE,IN 47907. RP AGBLEVOR, FA (reprint author), NATL RENEWABLE ENERGY LAB,1617 COLE BLVD,GOLDEN,CO 80401, USA. NR 23 TC 43 Z9 44 U1 0 U2 13 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0165-2370 J9 J ANAL APPL PYROL JI J. Anal. Appl. Pyrolysis PD DEC PY 1994 VL 30 IS 2 BP 125 EP 144 DI 10.1016/0165-2370(94)00808-6 PG 20 WC Chemistry, Analytical; Spectroscopy SC Chemistry; Spectroscopy GA PY558 UT WOS:A1994PY55800001 ER PT J AU HINDS, MW BROWN, GN STYRIS, DL AF HINDS, MW BROWN, GN STYRIS, DL TI MECHANISMS CONTROLLING THE DIRECT SOLID SAMPLING OF SILICON FROM GOLD SAMPLES BY ATOMIC-ABSORPTION SPECTROMETRY WITH ELECTROTHERMAL ATOMIZATION .1. ANALYTE MIGRATION TO THE SOLID-SURFACE SO JOURNAL OF ANALYTICAL ATOMIC SPECTROMETRY LA English DT Article DE GRAPHITE FURNACE ATOMIZER; ELECTROTHERMAL ATOMIC ABSORPTION SPECTROMETRY; SOLID SAMPLE ANALYSIS; SILICON; ATOMIZATION MECHANISM AB The results of electrothermal atomic absorption spectrometry (ETAAS) investigations of Si vaporization from solid gold samples indicate that Si is released only after melting of the gold matrix, and the migration of Si to the surface is assisted by the formation of convection cells in the melt. This convection is driven by the thermal gradients in the sample. Diffusion alone, in either the solid or the melt, is too slow to account for the relatively short time for total Si release before a significant portion of the gold matrix is depleted. Silicon that is carried by the induced convection to the surface is readily vaporized. It is shown that the liquidus lines of the binary phase diagrams associated with a gold solvent can be used to predict the existence of analyte carryover in the gold, Consequently, these diagrams offer a means of identifying, a priori, candidate elements that may be determined by solid sampling ETAAS in gold, via aqueous solution calibration. C1 PACIFIC NW LAB, RICHLAND, WA 99352 USA. RP HINDS, MW (reprint author), ROYAL CANADIAN MINT, 320 SUSSEX DR, OTTAWA, ON K1A 0G8, CANADA. NR 20 TC 11 Z9 11 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 DEC PY 1994 VL 9 IS 12 BP 1411 EP 1416 DI 10.1039/ja9940901411 PG 6 WC Chemistry, Analytical; Spectroscopy SC Chemistry; Spectroscopy GA PY149 UT WOS:A1994PY14900014 ER PT J AU FINGER, LW COX, DE JEPHCOAT, AP AF FINGER, LW COX, DE JEPHCOAT, AP TI A CORRECTION FOR POWDER DIFFRACTION PEAK ASYMMETRY DUE TO AXIAL DIVERGENCE SO JOURNAL OF APPLIED CRYSTALLOGRAPHY LA English DT Article AB Analysis of a crystal structure using the Rietveld profile technique requires a suitable description of the shape of the peaks. In general, modern refinement codes include accurate formulations for most effects; however, the functions used for peak asymmetry are semi-empirical and take very little account of diffraction optics. The deficiencies in these methods are most obvious for high-resolution instruments. This study describes the implementation of powder diffraction peak profile formulations devised by van Laar and Yelon [J. Appl. Cryst. (1984), 17, 47-54]. This formalism, which describes the asymmetry due to axial divergence in terms of finite sample and detector sizes, does not require any free parameters and contains intrinsic corrections for the angular dependence of the peak shape. The method results in an accurate description of the observed profiles for a variety of geometries, including conventional X-ray diffractometers, synchrotron instruments with or without crystal analyzers and neutron diffractometers. C1 CTR HIGH PRESSURE RES,WASHINGTON,DC 20015. BROOKHAVEN NATL LAB,DEPT PHYS,UPTON,NY 11973. UNIV OXFORD,DEPT EARTH SCI,OXFORD OX1 3PR,ENGLAND. RP FINGER, LW (reprint author), GEOPHYS LAB,WASHINGTON,DC 20015, USA. NR 23 TC 876 Z9 877 U1 3 U2 56 PU MUNKSGAARD INT PUBL LTD PI COPENHAGEN PA 35 NORRE SOGADE, PO BOX 2148, DK-1016 COPENHAGEN, DENMARK SN 0021-8898 J9 J APPL CRYSTALLOGR JI J. Appl. Crystallogr. PD DEC 1 PY 1994 VL 27 BP 892 EP 900 DI 10.1107/S0021889894004218 PN 6 PG 9 WC Chemistry, Multidisciplinary; Crystallography SC Chemistry; Crystallography GA PW307 UT WOS:A1994PW30700004 ER PT J AU BELLAMY, HD PHIZACKERLEY, RP SOLTIS, SM HOPE, H AF BELLAMY, HD PHIZACKERLEY, RP SOLTIS, SM HOPE, H TI AN OPEN-FLOW CRYOGENIC COOLER FOR SINGLE-CRYSTAL DIFFRACTION EXPERIMENTS SO JOURNAL OF APPLIED CRYSTALLOGRAPHY LA English DT Article ID BIOLOGICAL MACROMOLECULES; CRYSTALLOGRAPHY; CRYOCRYSTALLOGRAPHY; PROTEIN AB A simple, low-cost and efficient open-flow cryogenic cooling system has been constructed for crystallographic data collection from flash-cooled protein crystals on the rotation-camera station at the Stanford Synchrotron Radiation Laboratory. A constant temperature of less than 100 K at the crystal position can be maintained for an indefinite period of time. A small heater surrounding the delivery nozzle and another between the sample crystal and the sample support are used to prevent the formation of ice. The system includes an automatic filling capability so that the device can be run unattended for up to approximately one week. C1 UNIV CALIF DAVIS,DEPT CHEM,DAVIS,CA 95616. RP BELLAMY, HD (reprint author), STANFORD UNIV,SLAC,STANFORD SYNCHROTRON RADIAT LAB,POB 4349,BIN 69,STANFORD,CA 94309, USA. NR 9 TC 10 Z9 10 U1 0 U2 0 PU MUNKSGAARD INT PUBL LTD PI COPENHAGEN PA 35 NORRE SOGADE, PO BOX 2148, DK-1016 COPENHAGEN, DENMARK SN 0021-8898 J9 J APPL CRYSTALLOGR JI J. Appl. Crystallogr. PD DEC 1 PY 1994 VL 27 BP 967 EP 970 DI 10.1107/S0021889894006357 PN 6 PG 4 WC Chemistry, Multidisciplinary; Crystallography SC Chemistry; Crystallography GA PW307 UT WOS:A1994PW30700013 ER PT J AU DAROVSKY, A BOLOTOVSKY, R COPPENS, P AF DAROVSKY, A BOLOTOVSKY, R COPPENS, P TI AN ANTISCATTER DEVICE FOR LOW-TEMPERATURE CRYSTALLOGRAPHIC EXPERIMENTS WITH IMAGING PLATES SO JOURNAL OF APPLIED CRYSTALLOGRAPHY LA English DT Note ID DIFFRACTOMETER AB The use of area detectors in low-temperature crystallographic data collection requires new methods for elimination of scattering by cryostat chambers, as diffracted-beam collimators can no longer be employed. The antiscatter device described is mounted inside the vacuum chamber and kept stationary during sample rotation by the use of a magnetic clamp. The device has been tested on both conventional and synchrotron sources. C1 SUNY BUFFALO,DEPT CHEM,BUFFALO,NY 14260. RP DAROVSKY, A (reprint author), SUNY,BROOKHAVEN NATL LAB,X3 BEAMLINE,UPTON,NY 11973, USA. NR 2 TC 21 Z9 21 U1 0 U2 0 PU MUNKSGAARD INT PUBL LTD PI COPENHAGEN PA 35 NORRE SOGADE, PO BOX 2148, DK-1016 COPENHAGEN, DENMARK SN 0021-8898 J9 J APPL CRYSTALLOGR JI J. Appl. Crystallogr. PD DEC 1 PY 1994 VL 27 BP 1039 EP 1040 DI 10.1107/S0021889894006369 PN 6 PG 2 WC Chemistry, Multidisciplinary; Crystallography SC Chemistry; Crystallography GA PW307 UT WOS:A1994PW30700023 ER PT J AU HENDERSON, SJ AF HENDERSON, SJ TI MODIFICATION OF STANDARD X-RAY GLASS-CAPILLARIES TO IMPROVE DATA FOR SMALL-ANGLE SCATTERING SO JOURNAL OF APPLIED CRYSTALLOGRAPHY LA English DT Note AB X-ray capillaries are widely used in diffraction work, in diverse areas from protein crystallography to small angle X-ray scattering (SAXS). The capillary modification described in this work was developed for small-angle X-ray scattering on protein solutions. RP HENDERSON, SJ (reprint author), OAK RIDGE NATL LAB,DIV BIOL,POB 2009,OAK RIDGE,TN 37831, USA. NR 0 TC 2 Z9 2 U1 0 U2 1 PU MUNKSGAARD INT PUBL LTD PI COPENHAGEN PA 35 NORRE SOGADE, PO BOX 2148, DK-1016 COPENHAGEN, DENMARK SN 0021-8898 J9 J APPL CRYSTALLOGR JI J. Appl. Crystallogr. PD DEC 1 PY 1994 VL 27 BP 1067 EP 1067 DI 10.1107/S0021889894008940 PN 6 PG 1 WC Chemistry, Multidisciplinary; Crystallography SC Chemistry; Crystallography GA PW307 UT WOS:A1994PW30700033 ER PT J AU MAJOR, RW WERNER, AE WILSON, CB MODINE, FA AF MAJOR, RW WERNER, AE WILSON, CB MODINE, FA TI POLARIZATION CURRENTS IN ZINC-OXIDE VARISTORS FROM 77-K TO 450-K SO JOURNAL OF APPLIED PHYSICS LA English DT Article ID ZNO VARISTORS; CONDUCTION MECHANISM; GRAIN-BOUNDARIES; ELECTRON TRAPS; CERAMICS C1 OAK RIDGE NATL LAB,DIV SOLID STATE,OAK RIDGE,TN 37831. RP MAJOR, RW (reprint author), UNIV RICHMOND,DEPT PHYS,RICHMOND,VA 23173, USA. NR 33 TC 1 Z9 1 U1 0 U2 3 PU AMER INST PHYSICS PI WOODBURY PA CIRCULATION FULFILLMENT DIV, 500 SUNNYSIDE BLVD, WOODBURY, NY 11797-2999 SN 0021-8979 J9 J APPL PHYS JI J. Appl. Phys. PD DEC 1 PY 1994 VL 76 IS 11 BP 7367 EP 7371 DI 10.1063/1.357960 PG 5 WC Physics, Applied SC Physics GA PU818 UT WOS:A1994PU81800028 ER PT J AU MCMASTER, MC HSU, WL COLTRIN, ME DANDY, DS AF MCMASTER, MC HSU, WL COLTRIN, ME DANDY, DS TI EXPERIMENTAL MEASUREMENTS AND NUMERICAL SIMULATIONS OF THE GAS-COMPOSITION IN A HOT-FILAMENT-ASSISTED DIAMOND CHEMICAL-VAPOR-DEPOSITION REACTOR SO JOURNAL OF APPLIED PHYSICS LA English DT Article ID H-ATOM CONCENTRATIONS; MICROWAVE PLASMA; METHANE-HYDROGEN; GROWTH; KINETICS; FILMS; TEMPERATURE; ENVIRONMENT; CHEMISTRY; MIXTURES C1 SANDIA NATL LABS,LIVERMORE,CA 94551. SANDIA NATL LABS,ALBUQUERQUE,NM 87185. COLORADO STATE UNIV,DEPT CHEM ENGN,FT COLLINS,CO 80523. RI Dandy, David/G-6984-2012 OI Dandy, David/0000-0003-3254-0717 NR 50 TC 49 Z9 52 U1 2 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 DEC 1 PY 1994 VL 76 IS 11 BP 7567 EP 7577 DI 10.1063/1.358525 PG 11 WC Physics, Applied SC Physics GA PU818 UT WOS:A1994PU81800061 ER PT J AU MALDENER, I FIEDLER, G ERNST, A FERNANDEZPINAS, F WOLK, CP AF MALDENER, I FIEDLER, G ERNST, A FERNANDEZPINAS, F WOLK, CP TI CHARACTERIZATION OF DEVA, A GENE REQUIRED FOR THE MATURATION OF PROHETEROCYSTS IN THE CYANOBACTERIUM ANABAENA SP STRAIN PCC-7120 SO JOURNAL OF BACTERIOLOGY LA English DT Article ID ESCHERICHIA-COLI; HETEROCYST DEVELOPMENT; SALMONELLA-TYPHIMURIUM; PERIPLASMIC TRANSPORT; CELL-ENVELOPE; EXPRESSION; SEQUENCE; CLONING; OPERON; DIFFERENTIATION AB Mutant M7, obtained by transposon mutagenesis of the cyanobacterium Anabaena sp. strain PCC 7120, is impaired in the development of mature heterocysts. Under aerobic conditions, the mutant is unable to fix N-2 because of a deficiency of at least mo components of the oxygen-protective mechanisms: a hemoprotein-coupled oxidative reaction and heterocyst specific glycolipids. DNA contiguous with the inserted transposon was recovered from the mutant and sequenced. The transposon had inserted itself within a 732-bp open reading frame designated devA. The wild-type form of devA, obtained from a lambda-EMBL3 library of Anabaena sp. DNA, had the identical sequence. Directed mutagenesis of devA in the wild-type strain showed that the phenotype of the mutant was caused by insertion of the transposon. The wild-type form of devA on a shuttle vector complemented the mutation in M7. Expression of devA by whole filaments, monitored following nitrogen stepdown by using luxAB as the reporter, increased ca. eightfold during differentiation; the increase within differentiating cells was much greater. The deduced sequence of the DevA protein shows strong similarity to the ATP-binding subunit of binding protein-dependent transport systems. The product of devA may, therefore, be a component of a periplasmic permease that is required for the transition from a proheterocyst to a mature, nitrogen-fixing heterocyst. C1 MICHIGAN STATE UNIV,US DOE,PLANT RES LAB,E LANSING,MI 48824. UNIV REGENSBURG,LEHRSTUHL ZELLBIOL & PFLANZENPHYSIOL,D-93040 REGENSBURG,GERMANY. OI Fernandez-Pinas, Francisca/0000-0002-7444-7601 NR 45 TC 32 Z9 33 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 DEC PY 1994 VL 176 IS 24 BP 7543 EP 7549 PG 7 WC Microbiology SC Microbiology GA PX081 UT WOS:A1994PX08100017 PM 8002578 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 EFFECTS OF DISPERSION AND METAL-METAL OXIDE INTERACTIONS ON FISCHER-TROPSCH SYNTHESIS OVER RU/TIO2 AND TIO2-PROMOTED RU/SIO2 SO JOURNAL OF CATALYSIS LA English DT Article ID CARBON-MONOXIDE HYDROGENATION; SUPPORTED RUTHENIUM CATALYSTS; RH FOIL; TITANIA OVERLAYERS; NI/AL2O3 CATALYSTS; CO HYDROGENATION; CHEMISORPTION; ADSORPTION; SPILLOVER; PLATINUM AB The activity of Ru/TiO2 and TiO2-promoted Ru/SiO2 catalysts for Fischer-Tropsch synthesis has been investigated. The Ru dispersion of these catalysts was determined by TEM, and the fraction of the Ru surface available for H-2 adsorption was determined by H-1 NMR. Even after low-temperature reduction, the surface of titania-containing catalysts is covered by titania to a substantial degree. The specific activity and selectivity of these catalysts are dominated by the interactions occurring between the Ru particles and the titania overlayer. As the fraction of the Ru particle surface covered by titania increases, the turnover frequency for CO consumption passes through a maximum, while that for methane formation decreases monotonically. The probability for chain growth and the olefin-to-paraffin ratio of the products increase with increasing titania coverage. These trends are attributed to the effects of the titania overlayer on the catalytic properties of Ru. (C) 1994 Academic Press, Inc. C1 LAWRENCE BERKELEY LAB, DIV MAT SCI, BERKELEY, CA 94720 USA. UNIV CALIF BERKELEY, DEPT CHEM ENGN, 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. RP LAWRENCE BERKELEY LAB, DIV CHEM SCI, BERKELEY, CA 94720 USA. OI Bell, Alexis/0000-0002-5738-4645 NR 32 TC 35 Z9 36 U1 3 U2 27 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 DEC PY 1994 VL 150 IS 2 BP 400 EP 406 DI 10.1006/jcat.1994.1358 PG 7 WC Chemistry, Physical; Engineering, Chemical SC Chemistry; Engineering GA PX198 UT WOS:A1994PX19800019 ER PT J AU RUSCIC, B BERKOWITZ, J AF RUSCIC, B BERKOWITZ, J TI THRESHOLD PHOTOELECTRON-SPECTRUM OF HOBR SO JOURNAL OF CHEMICAL PHYSICS LA English DT Article ID PHOTOIONIZATION RP RUSCIC, B (reprint author), ARGONNE NATL LAB,DIV CHEM,9700 S CASS AVE,ARGONNE,IL 60439, USA. RI Ruscic, Branko/A-8716-2008 OI Ruscic, Branko/0000-0002-4372-6990 NR 12 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 0021-9606 J9 J CHEM PHYS JI J. Chem. Phys. PD DEC 1 PY 1994 VL 101 IS 11 BP 9215 EP 9218 DI 10.1063/1.468012 PG 4 WC Chemistry, Physical; Physics, Atomic, Molecular & Chemical SC Chemistry; Physics GA PV956 UT WOS:A1994PV95600001 ER PT J AU CHANG, BC WU, M HALL, GE SEARS, TJ AF CHANG, BC WU, M HALL, GE SEARS, TJ TI NEAR-INFRARED VIBRONIC SPECTRUM OF THE CH2 (B)OVER-TILDE B-1(1)[-(A)OVER-TILDE (1)A(1) TRANSITION SO JOURNAL OF CHEMICAL PHYSICS LA English DT Article ID MAGNETIC-ROTATION SPECTROSCOPY; PHOTOFRAGMENTATION DYNAMICS; VECTOR CORRELATIONS; VISIBLE ABSORPTION; SINGLET THRESHOLD; KETENE; DISSOCIATION; STATE; METHYLENE; CO RP CHANG, BC (reprint author), BROOKHAVEN NATL LAB,DEPT CHEM,UPTON,NY 11973, USA. RI Sears, Trevor/B-5990-2013; Hall, Gregory/D-4883-2013 OI Sears, Trevor/0000-0002-5559-0154; Hall, Gregory/0000-0002-8534-9783 NR 24 TC 45 Z9 45 U1 0 U2 0 PU AMER INST PHYSICS PI WOODBURY PA CIRCULATION FULFILLMENT DIV, 500 SUNNYSIDE BLVD, WOODBURY, NY 11797-2999 SN 0021-9606 J9 J CHEM PHYS JI J. Chem. Phys. PD DEC 1 PY 1994 VL 101 IS 11 BP 9236 EP 9245 DI 10.1063/1.468015 PG 10 WC Chemistry, Physical; Physics, Atomic, Molecular & Chemical SC Chemistry; Physics GA PV956 UT WOS:A1994PV95600004 ER PT J AU HARRIS, RA TINOCO, I AF HARRIS, RA TINOCO, I TI LASER-PERTURBED NUCLEAR-MAGNETIC-RESONANCE SPECTROSCOPY AND THE CONSERVATION OF PARITY SO JOURNAL OF CHEMICAL PHYSICS LA English DT Article ID ENHANCED NMR-SPECTROSCOPY; THEORETICAL CONSIDERATIONS C1 UNIV CALIF BERKELEY,LAWRENCE BERKELEY LAB,DIV STRUCT BIOL,BERKELEY,CA 94720. RP HARRIS, RA (reprint author), UNIV CALIF BERKELEY,DEPT CHEM,BERKELEY,CA 94720, USA. NR 11 TC 25 Z9 25 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 DEC 1 PY 1994 VL 101 IS 11 BP 9289 EP 9294 DI 10.1063/1.467959 PG 6 WC Chemistry, Physical; Physics, Atomic, Molecular & Chemical SC Chemistry; Physics GA PV956 UT WOS:A1994PV95600011 ER PT J AU KERN, S HAYWARD, J ROBERTS, S RICHARDSON, JW ROTELLA, FJ SODERHOLM, L CORT, B TINKLE, M WEST, M HOISINGTON, D LANDER, GH AF KERN, S HAYWARD, J ROBERTS, S RICHARDSON, JW ROTELLA, FJ SODERHOLM, L CORT, B TINKLE, M WEST, M HOISINGTON, D LANDER, GH TI TEMPERATURE-VARIATION OF THE STRUCTURAL PARAMETERS IN ACTINIDE TETRAFLUORIDES SO JOURNAL OF CHEMICAL PHYSICS LA English DT Article C1 ARGONNE NATL LAB,DIV INTENSE PULSED NEUTRON,ARGONNE,IL 60439. ARGONNE NATL LAB,DIV CHEM,ARGONNE,IL 60439. LOS ALAMOS NATL LAB,DIV NUCL MAT,LOS ALAMOS,NM 87545. INST TRANSURANIUM ELEMENTS,JRC,EUROPEAN COMMISS,D-76125 KARLSRUHE,GERMANY. RP KERN, S (reprint author), COLORADO STATE UNIV,DEPT PHYS,FT COLLINS,CO 80523, USA. NR 4 TC 7 Z9 7 U1 0 U2 2 PU AMER INST PHYSICS PI WOODBURY PA CIRCULATION FULFILLMENT DIV, 500 SUNNYSIDE BLVD, WOODBURY, NY 11797-2999 SN 0021-9606 J9 J CHEM PHYS JI J. Chem. Phys. PD DEC 1 PY 1994 VL 101 IS 11 BP 9333 EP 9337 DI 10.1063/1.467963 PG 5 WC Chemistry, Physical; Physics, Atomic, Molecular & Chemical SC Chemistry; Physics GA PV956 UT WOS:A1994PV95600015 ER PT J AU KERN, S LANDER, GH SODERHOLM, L LOONG, CK TROUW, F WEST, M HOISINGTON, D CORT, B WELP, U AF KERN, S LANDER, GH SODERHOLM, L LOONG, CK TROUW, F WEST, M HOISINGTON, D CORT, B WELP, U TI NEUTRON INELASTIC-SCATTERING STUDIES OF UF4 AND NPF4 SO JOURNAL OF CHEMICAL PHYSICS LA English DT Article ID CRYSTAL-FIELD; SINGLE-CRYSTAL; SPECTROSCOPY; ERBA2CU3OX; SPECTRA; DIOXIDE; MODEL; UCL4 C1 ARGONNE NATL LAB,DIV INTENSE PULSED NEUTRON,ARGONNE,IL 60439. INST TRANSURANIUM ELEMENTS,JRC,EUROPEAN COMMISS,D-76125 KARLSRUHE,GERMANY. ARGONNE NATL LAB,DIV CHEM,ARGONNE,IL 60439. LOS ALAMOS NATL LAB,DIV NUCL MAT,LOS ALAMOS,NM 87545. ARGONNE NATL LAB,DIV MAT SCI,ARGONNE,IL 60439. RP KERN, S (reprint author), COLORADO STATE UNIV,DEPT PHYS,FT COLLINS,CO 80523, USA. RI Lujan Center, LANL/G-4896-2012 NR 30 TC 5 Z9 5 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 DEC 1 PY 1994 VL 101 IS 11 BP 9338 EP 9343 DI 10.1063/1.467964 PG 6 WC Chemistry, Physical; Physics, Atomic, Molecular & Chemical SC Chemistry; Physics GA PV956 UT WOS:A1994PV95600016 ER PT J AU KUMARAN, SS LIM, KP MICHAEL, JV AF KUMARAN, SS LIM, KP MICHAEL, JV TI THERMAL RATE CONSTANTS FOR THE CL+H-2 AND CL+D-2 REACTIONS BETWEEN 296 AND 3000 K SO JOURNAL OF CHEMICAL PHYSICS LA English DT Article ID SHOCK-TUBE TECHNIQUE; TEMPERATURE-RANGE; FLASH-PHOTOLYSIS; LASER PHOTOLYSIS; ABSOLUTE RATE; CL-H2 SYSTEM; 200-500 K; ABSORPTION; HYDROGEN; KINETICS C1 ARGONNE NATL LAB,DIV CHEM,ARGONNE,IL 60439. RI Michael, Joe/E-3907-2010 NR 57 TC 62 Z9 62 U1 1 U2 3 PU AMER INST PHYSICS PI WOODBURY PA CIRCULATION FULFILLMENT DIV, 500 SUNNYSIDE BLVD, WOODBURY, NY 11797-2999 SN 0021-9606 J9 J CHEM PHYS JI J. Chem. Phys. PD DEC 1 PY 1994 VL 101 IS 11 BP 9487 EP 9498 DI 10.1063/1.468486 PG 12 WC Chemistry, Physical; Physics, Atomic, Molecular & Chemical SC Chemistry; Physics GA PV956 UT WOS:A1994PV95600033 ER PT J AU HERNANDEZ, R AF HERNANDEZ, R TI A COMBINED USE OF PERTURBATION-THEORY AND DIAGONALIZATION - APPLICATION OF BOUND-ENERGY LEVELS AND SEMICLASSICAL RATE THEORY SO JOURNAL OF CHEMICAL PHYSICS LA English DT Article ID TRANSITION-STATE THEORY; CUMULATIVE REACTION PROBABILITIES; INVERSION-ROTATION SPECTRA; ANHARMONIC-FORCE FIELD; POLYATOMIC-MOLECULES; ARTIFICIAL-INTELLIGENCE; INTRAMOLECULAR DYNAMICS; CENTRIFUGAL-DISTORTION; EFFECTIVE-HAMILTONIANS; TRIATOMIC MOLECULE C1 UNIV CALIF BERKELEY,DEPT CHEM,BERKELEY,CA 94720. UNIV CALIF BERKELEY,LAWRENCE BERKELEY LAB,DIV CHEM SCI,BERKELEY,CA 94720. RI Hernandez, Rigoberto/A-8793-2008 OI Hernandez, Rigoberto/0000-0001-8526-7414 NR 56 TC 39 Z9 39 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 DEC 1 PY 1994 VL 101 IS 11 BP 9534 EP 9547 DI 10.1063/1.467985 PG 14 WC Chemistry, Physical; Physics, Atomic, Molecular & Chemical SC Chemistry; Physics GA PV956 UT WOS:A1994PV95600039 ER PT J AU ODUTOLA, JA LESTER, WA AF ODUTOLA, JA LESTER, WA TI MOLECULAR-REORIENTATION CROSS-SECTIONS IN COLLISIONS OF HE(S-1)+D-2(B-1-SIGMA-U(+)), HD(B-1-SIGMA(U)(+)) SO JOURNAL OF CHEMICAL PHYSICS LA English DT Article ID POTENTIAL-ENERGY SURFACES; H-2(B1-SIGMA-U+); SCATTERING; MINIMUM C1 UNIV CALIF BERKELEY,LAWRENCE BERKELEY LAB,DIV CHEM SCI,BERKELEY,CA 94720. UNIV CALIF BERKELEY,DEPT CHEM,BERKELEY,CA 94720. NR 21 TC 2 Z9 2 U1 0 U2 0 PU AMER INST PHYSICS PI WOODBURY PA CIRCULATION FULFILLMENT DIV, 500 SUNNYSIDE BLVD, WOODBURY, NY 11797-2999 SN 0021-9606 J9 J CHEM PHYS JI J. Chem. Phys. PD DEC 1 PY 1994 VL 101 IS 11 BP 9619 EP 9623 DI 10.1063/1.468484 PG 5 WC Chemistry, Physical; Physics, Atomic, Molecular & Chemical SC Chemistry; Physics GA PV956 UT WOS:A1994PV95600048 ER PT J AU PESKIN, U REISLER, H MILLER, WH AF PESKIN, U REISLER, H MILLER, WH TI ON THE RELATION BETWEEN UNIMOLECULAR REACTION-RATES AND OVERLAPPING RESONANCES SO JOURNAL OF CHEMICAL PHYSICS LA English DT Article ID CUMULATIVE REACTION PROBABILITY; TRANSITION-STATE THEORY; ABSORBING BOUNDARY-CONDITIONS; RATE CONSTANTS; DISSOCIATION THRESHOLD; DECOMPOSITION; FLUCTUATIONS; FORMALDEHYDE; NO2; SYSTEMS C1 UNIV CALIF BERKELEY,LAWRENCE BERKELEY LAB,DIV CHEM SCI,BERKELEY,CA 94720. UNIV SO CALIF,DEPT CHEM,LOS ANGELES,CA 90089. RP PESKIN, U (reprint author), UNIV CALIF BERKELEY,DEPT CHEM,BERKELEY,CA 94720, USA. NR 38 TC 77 Z9 77 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 DEC 1 PY 1994 VL 101 IS 11 BP 9672 EP 9680 DI 10.1063/1.467932 PG 9 WC Chemistry, Physical; Physics, Atomic, Molecular & Chemical SC Chemistry; Physics GA PV956 UT WOS:A1994PV95600054 ER PT J AU JELLINEK, J BONACICKOUTECKY, V FANTUCCI, P WIECHERT, M AF JELLINEK, J BONACICKOUTECKY, V FANTUCCI, P WIECHERT, M TI AB-INITIO HARTREE-FOCK SELF-CONSISTENT-FIELD MOLECULAR-DYNAMICS STUDY OF STRUCTURE AND DYNAMICS OF LI-8 SO JOURNAL OF CHEMICAL PHYSICS LA English DT Article ID ABINITIO CONFIGURATION-INTERACTION; DENSITY-FUNCTIONAL THEORY; METAL-CLUSTERS; SILICON MICROCLUSTERS; ELECTRONIC-STRUCTURE; LITHIUM CLUSTERS; EQUILIBRIUM; SYSTEMS; SURFACE; STATES C1 HUMBOLDT UNIV BERLIN,WALTHER NERNST INST PHYS & THEORET CHEM,D-10117 BERLIN,GERMANY. CNR,DIPARTIMENTO CHIM INORGAN MET ORGAN & ANALIT,I-20133 MILAN,ITALY. FREE UNIV BERLIN,INST PHYS & THEORET CHEM,D-14195 BERLIN,GERMANY. RP JELLINEK, J (reprint author), ARGONNE NATL LAB,DIV CHEM,9700 S CASS AVE,ARGONNE,IL 60439, USA. NR 47 TC 59 Z9 61 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 DEC 1 PY 1994 VL 101 IS 11 BP 10092 EP 10100 DI 10.1063/1.467997 PG 9 WC Chemistry, Physical; Physics, Atomic, Molecular & Chemical SC Chemistry; Physics GA PV956 UT WOS:A1994PV95600101 ER PT J AU ZHONG, SB GOLDBERG, IJ BRUCE, C RUBIN, E BRESLOW, JL TALL, A AF ZHONG, SB GOLDBERG, IJ BRUCE, C RUBIN, E BRESLOW, JL TALL, A TI HUMAN APOA-II INHIBITS THE HYDROLYSIS OF HDL TRIGLYCERIDE AND THE DECREASE OF HDL SIZE INDUCED BY HYPERTRIGLYCERIDEMIA AND CHOLESTERYL ESTER TRANSFER PROTEIN IN TRANSGENIC MICE SO JOURNAL OF CLINICAL INVESTIGATION LA English DT Article DE TRANSGENIC MICE; CHOLESTERYL ESTER TRANSFER PROTEIN; APOLIPOPROTEIN A-II; HIGH DENSITY LIPOPROTEINS; HEPATIC LIPASE ID HIGH-DENSITY-LIPOPROTEIN; APOLIPOPROTEIN-A-I; GRADIENT GEL-ELECTROPHORESIS; POST-HEPARIN PLASMA; HEPATIC LIPASE; METABOLISM; GENE; ATHEROSCLEROSIS; DEFICIENCY; EXPRESSION AB The plasma cholesteryl ester transfer protein(CETP) mediates the exchange of HDL cholesteryl esters with triglycerides of other lipoproteins. Subsequent lipolysis of the triglyceride-enriched HDL by hepatic lipase leads to reductions of HDL size and apoA-I content. To investigate a possible modulation of the effects of CETP by apoA-II, human CETP transgenic mice were cross-bred with transgenic mice expressing human apoA-II and, in some cases, human apoA-I and apoC-III (with human-like HDL and hypertriglyceridemia). CETP expression resulted in reductions of HDL and increases in VLDL cholesteryl ester in mice expressing human apoA-II, alone or in combination with apoA-I and apoC-III, indicating that apoA-II does not inhibit the cholesteryl ester transfer activity of CETP. However, CETP expression resulted in more prominent increases in HDL triglyceride in mice expressing both apoA-II and CETP, especially in CETP/apoA-II/apoAI-CIII transgenic mice. CETP expression caused dramatic reductions in HDL size and apoA-I content in apoAI-CIII transgenic mice, but not in apoA-II/AI-CIII transgenic mice. HDL prepared from mice of various genotypes showed inhibition of emulsion-based hepatic lipase activity in proportion to the apoA-II/apoA-I ratio of HDL. The presence of human apoA-II also inhibited mouse plasma hepatic lipase activity on HDL triglyceride. Thus, apoA-II does not inhibit the lipid transfer activity of CETP in vivo. However, coexpression of apoA-II with CETP results in HDL particles that are more triglyceride enriched and resistant to reductions in size and apoA-I content, reflecting inhibition of hepatic lipase by apoA-II. The inhibition of HDL remodeling by apoA-II could explain the relatively constant levels of HDL containing both apoA-I and apoA-II in human populations. C1 COLUMBIA UNIV,DEPT MED,DIV MOLEC MED,NEW YORK,NY 10032. COLUMBIA UNIV,DEPT MED,DIV PREVENT MED & NUTR,NEW YORK,NY 10032. UNIV CALIF BERKELEY,LAWRENCE BERKELEY LAB,BERKELEY,CA 94720. ROCKEFELLER UNIV,NEW YORK,NY 10021. RI Breslow, Jan/B-7544-2008; Bruce, Can/A-6949-2015 OI Bruce, Can/0000-0002-3101-1250 FU NHLBI NIH HHS [HL-21006, HL-33714, HL-45095] NR 56 TC 73 Z9 73 U1 0 U2 2 PU ROCKEFELLER UNIV PRESS PI NEW YORK PA 1114 FIRST AVE, 4TH FL, NEW YORK, NY 10021 SN 0021-9738 J9 J CLIN INVEST JI J. Clin. Invest. PD DEC PY 1994 VL 94 IS 6 BP 2457 EP 2467 DI 10.1172/JCI117614 PG 11 WC Medicine, Research & Experimental SC Research & Experimental Medicine GA PV810 UT WOS:A1994PV81000040 PM 7989603 ER PT J AU BYERS, JA DIMITS, AM MATSUDA, Y LANGDON, AB AF BYERS, JA DIMITS, AM MATSUDA, Y LANGDON, AB TI NUMERICAL INSTABILITY IN A 2D GYROKINETIC CODE CAUSED BY DIVERGENT E-X-B FLOW SO JOURNAL OF COMPUTATIONAL PHYSICS LA English DT Article ID PARTICLE SIMULATION; DRIFT INSTABILITIES AB In this paper, a numerical instability first observed in a 2D electrostatic gyrokinetic code is described. The instability should also be present in some form in many versons of particle-in-cell simulation codes that employ guiding center drifts. A perturbation analysis of the instability is given and its results agree quantitatively with the observations from the gyrokinetic code in all respects. The basic mechanism is a false divergence of the E x B flow caused by the interpolation between the grid and the particles as coupled with the specific numerical method for calculating E = del phi. Stability or instability depends in detail on the specific choice of particle interpolation method and field method. One common interpolation method, subtracted dipole, is stable. Other commonly used interpolation methods, linear and quadratic, are unstable when combined with a finite difference for the electric field. Linear and quadratic interpolation can be rendered stable if combined with another method for the electric field, the analytic differential of the interpolated potential. (C) 1994 Academic Press, Inc. RP BYERS, JA (reprint author), LAWRENCE LIVERMORE NATL LAB,LIVERMORE,CA 94550, USA. NR 16 TC 5 Z9 5 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 DEC PY 1994 VL 115 IS 2 BP 352 EP 365 DI 10.1006/jcph.1994.1201 PG 14 WC Computer Science, Interdisciplinary Applications; Physics, Mathematical SC Computer Science; Physics GA PU775 UT WOS:A1994PU77500009 ER PT J AU PAIK, S NGUYEN, HD CHUNG, JN AF PAIK, S NGUYEN, HD CHUNG, JN TI TRANSIENT CONJUGATED HEAT-TRANSFER ANALYSIS FROM A SPHERE WITH NONLINEAR BOUNDARY-CONDITIONS SO JOURNAL OF COMPUTATIONAL PHYSICS LA English DT Article ID LOW REYNOLDS-NUMBERS; FLOW AB The problem of conjugate unsteady convective and radiative heat transfer from a solid spherical particle is numerically investigated for Reynolds numbers up to 100 using a Chebyshev-Legendre spectral method. The treatment of nonlinear boundary condition of the radiation heat transfer from the sphere surface is assessed and successfully implemented. This work is an extension of the previous effort of simulating flow around a sphere using spectral method to include heat transfer. The assumption of quasi-steady flow field for the unsteady heat transfer calculation is compared with the fully transient treatment of both the flow and the temperature fields. It is found that the quasi-steady assumption underestimates the overall heat transfer rate at very early time stages (up to 9% underestimation for the mean Nusselt number). However, the discrepancy becomes smaller as time elapses. The underprediction of the quasi-steady assumption becomes larger as the Reynolds number increases for a fixed Prandtl number. The results for different alternate radiation-conduction number cases are presented. (C) 1994 Academic Press, Inc. C1 WASHINGTON STATE UNIV,DEPT MECH & MAT ENGN,PULLMAN,WA 99164. RP PAIK, S (reprint author), EG&G IDAHO INC,IDAHO NATL ENGN LAB,POB 1625,MS 3880,IDAHO FALLS,ID 83415, USA. NR 10 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 DEC PY 1994 VL 115 IS 2 BP 423 EP 430 DI 10.1006/jcph.1994.1207 PG 8 WC Computer Science, Interdisciplinary Applications; Physics, Mathematical SC Computer Science; Physics GA PU775 UT WOS:A1994PU77500015 ER PT J AU STILLER, L DAEMEN, LL GUBERNATIS, JE AF STILLER, L DAEMEN, LL GUBERNATIS, JE TI N-BODY SIMULATIONS ON MASSIVELY-PARALLEL ARCHITECTURES SO JOURNAL OF COMPUTATIONAL PHYSICS LA English DT Note ID PARTICLE SIMULATIONS; ALGORITHM C1 LOS ALAMOS NATL LAB,DIV THEORET,LOS ALAMOS,NM 87545. RP STILLER, L (reprint author), JOHNS HOPKINS UNIV,DEPT COMP SCI,BALTIMORE,MD 21218, USA. RI Lujan Center, LANL/G-4896-2012 NR 10 TC 3 Z9 3 U1 0 U2 0 PU ACADEMIC PRESS INC JNL-COMP SUBSCRIPTIONS PI SAN DIEGO PA 525 B ST, STE 1900, SAN DIEGO, CA 92101-4495 SN 0021-9991 J9 J COMPUT PHYS JI J. Comput. Phys. PD DEC PY 1994 VL 115 IS 2 BP 550 EP 552 DI 10.1006/jcph.1994.1216 PG 3 WC Computer Science, Interdisciplinary Applications; Physics, Mathematical SC Computer Science; Physics GA PU775 UT WOS:A1994PU77500024 ER PT J AU TOMPA, GS ZAWADZKI, PA MOY, K MCKEE, M THOMPSON, AG GURARY, AI WOLAK, E ESHERICK, P BREILAND, WG EVANS, GH BULITKA, N HENNESSY, J MOORE, CJL AF TOMPA, GS ZAWADZKI, PA MOY, K MCKEE, M THOMPSON, AG GURARY, AI WOLAK, E ESHERICK, P BREILAND, WG EVANS, GH BULITKA, N HENNESSY, J MOORE, CJL TI DESIGN AND OPERATING CHARACTERISTICS OF A METALORGANIC VAPOR-PHASE EPITAXY PRODUCTION SCALE, VERTICAL, HIGH-SPEED, ROTATING-DISK REACTOR SO JOURNAL OF CRYSTAL GROWTH LA English DT Article; Proceedings Paper CT 7th International Conference on Metalorganic Vapor Phase Epitaxy (ICMOVPE-VII) CY MAY 31-JUN 03, 1994 CL YOKOHAMA, JAPAN SP JAPAN SOC APPL PHYS, FDN ADV INT SCI ID QUANTUM-WELL HETEROSTRUCTURES; DEPOSITION REACTOR; HEAT-TRANSFER; GROWTH; UNIFORMITY; FLOW; GAAS AB The optoelectronic and digital compound semiconductor electronics industry is a critical area of development for the 90's and into the next century. Optoelectronic devices are used in all aspects of communications (lasers and detectors) and displays (LEDs). High speed electronic devices find applications in wireless communications, microwave systems, and advanced computers. As production levels of these devices increase, so too does the need for economical and high yield production equipment. Production features must emphasize repeatability, improved safety, environmental compatibility, waste reduction, reliability (maximum MTBF), serviceability (minimum MTTR), flexible manufacturing, integrated manufacturing, and economics. In this paper, we report on the development and characteristics of such a large area MOVPE production Rotating Disk Reactor system (300 mm diameter deposition platform). This new reactor has been used to produce multiple 4 inch GaAs/AlAs Bragg reflectors with < 1.0% variation in peak reflectivity wavelength and to simultaneously demonstrate multiple 2 inch InGaP films with better than +/- 1.5 nm photoluminescence wavelength uniformity. C1 SANDIA NATL LABS,ALBUQUERQUE,NM 87185. WATERLOO SCI,WATERLOO,ON N2L 3X2,CANADA. RP TOMPA, GS (reprint author), EMCORE CORP,EMCORE RES LABS,35 ELIZABETH AVE,SOMERSET,NJ 08873, USA. NR 22 TC 12 Z9 12 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 DEC PY 1994 VL 145 IS 1-4 BP 655 EP 661 DI 10.1016/0022-0248(94)91122-3 PG 7 WC Crystallography; Materials Science, Multidisciplinary; Physics, Applied SC Crystallography; Materials Science; Physics GA QC543 UT WOS:A1994QC54300103 ER PT J AU SCHNEIDER, RP LOTT, JA LEAR, KL CHOQUETTE, KD CRAWFORD, MH KILCOYNE, SP FIGIEL, JJ AF SCHNEIDER, RP LOTT, JA LEAR, KL CHOQUETTE, KD CRAWFORD, MH KILCOYNE, SP FIGIEL, JJ TI METALORGANIC VAPOR-PHASE EPITAXIAL-GROWTH OF RED AND INFRARED VERTICAL-CAVITY SURFACE-EMITTING LASER-DIODES SO JOURNAL OF CRYSTAL GROWTH LA English DT Article; Proceedings Paper CT 7th International Conference on Metalorganic Vapor Phase Epitaxy (ICMOVPE-VII) CY MAY 31-JUN 03, 1994 CL YOKOHAMA, JAPAN SP JAPAN SOC APPL PHYS, FDN ADV INT SCI ID DISTRIBUTED BRAGG REFLECTORS; RESISTANCE; PERFORMANCE; DESIGN; MOCVD AB Metalorganic vapor phase epitaxy (MOVPE) is used for the growth of vertical-cavity surface-emitting laser (VCSEL) diodes. MOVPE exhibits a number of important advantages over the more commonly-used molecular-beam epitaxial (MBE) techniques, including ease of continuous compositional grading and carbon doping for low-resistance p-type distributed Bragg reflectors (DBRs), higher growth rates for rapid throughput and greater versatility in choice of materials and dopants. Planar gain-guided red VCSELs based on AlGaInP/AlGaAs heterostructures lase continuous-wave at room temperature, with voltage thresholds between 2.5 and 3 V and maximum power outputs of over 0.3 mW. Top-emitting infra-red (IR) VCSELs exhibit the highest power-conversion (wall-plug) efficiencies (21%), lowest threshold voltage (1.47 V), and highest single mode power (4.4 mW from an 8 mu m device) yet reported. These results establish MOVPE as a preferred growth technique for this important new family of photonic devices. RP SCHNEIDER, RP (reprint author), SANDIA NATL LABS, POB 5800, ALBUQUERQUE, NM 87185 USA. NR 22 TC 10 Z9 10 U1 0 U2 3 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0022-0248 EI 1873-5002 J9 J CRYST GROWTH JI J. Cryst. Growth PD DEC PY 1994 VL 145 IS 1-4 BP 838 EP 845 DI 10.1016/0022-0248(94)91151-7 PG 8 WC Crystallography; Materials Science, Multidisciplinary; Physics, Applied SC Crystallography; Materials Science; Physics GA QC543 UT WOS:A1994QC54300132 ER PT J AU LEE, JH VERHOEVEN, JD AF LEE, JH VERHOEVEN, JD TI PERITECTIC FORMATION IN THE NI-AL SYSTEM SO JOURNAL OF CRYSTAL GROWTH LA English DT Article AB Directional solidification studies have been carried out on Ni-Al alloys at compositions in the two-phase region of the two phases, gamma and gamma', that form the peritectic in this system. It was found that under certain conditions of G/V, the two phases form with the banded structure found in previous directional solidification studies of peritectic systems. However, under other G/V conditions the two peritectic phases were found to grow into the liquid along an isothermal front lying just below the peritectic temperature. The growth front resembles those of lamellar and rod eutectic alloys because it lies as close to an isotherm as the growth fronts observed in eutectic alloys. However, the two solid phases display a morphology resembling that of classical two phase cellular growth where a second phase forms in-between the primary cells. The structure has been termed cellular coupled growth, and its morphology and the conditions for its formation are characterized and compared to eutectic and cellular growth morphologies. C1 IOWA STATE UNIV SCI & TECHNOL,AMES,IA 50011. US DOE,AMES LAB,AMES,IA 50011. NR 14 TC 96 Z9 103 U1 2 U2 16 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 DEC PY 1994 VL 144 IS 3-4 BP 353 EP 366 DI 10.1016/0022-0248(94)90477-4 PG 14 WC Crystallography; Materials Science, Multidisciplinary; Physics, Applied SC Crystallography; Materials Science; Physics GA PY405 UT WOS:A1994PY40500032 ER PT J AU NOBEL, PS ANDRADE, JL WANG, N NORTH, GB AF NOBEL, PS ANDRADE, JL WANG, N NORTH, GB TI WATER POTENTIALS FOR DEVELOPING CLADODES AND FRUITS OF A SUCCULENT PLANT, INCLUDING XYLEM-VERSUS-PHLOEM IMPLICATIONS FOR WATER-MOVEMENT SO JOURNAL OF EXPERIMENTAL BOTANY LA English DT Article DE OPUNTIA FICUS-INDICA; PHLOEM; RELATIVE WATER CONTENT; WATER CAPACITANCE; WATER POTENTIAL ID OPUNTIA-FICUS-INDICA; TRANSPIRATION FLOWS; ACCUMULATION; METABOLISM; TISSUES; SUCROSE; SUGARS; GROWTH; CACTI; ACID AB Developing cladodes had tower water potentials and developing fruits had higher water potentials than the underlying cladodes of the widely cultivated prickly pear cactus, Opuntia ficus-indica. The 0.06 MPa lower value in 4-week-old daughter cladodes indicated a typical water potential gradient from the underlying cladode along the xylem of -0.2 MPa m(-1); the 0.17 MPa higher value in 4-week-old fruits, which decreased to 0.07 MPa by 10 weeks, implicated the phloem as their supplier of water. The phloem sap of the underlying cladodes had an osmotic pressure of only 0.90 to 0.98 MPa, so the phloem could supply a relatively dilute solution to the photosynthetically dependent fruits (daughter cladodes of O. ficus-indica are photosynthetically independent at 4 weeks). Although the water potentials were similar for adjacent tissues, the osmotic pressures were lower for the water-storage compared with the photosynthetic tissue; the osmotic pressures were higher for xylem sap from fruits, for which xylary flow apparently occurred toward the underlying cladodes, than for daughter cladodes. The relative capacitance (change in relative water content divided by change in tissue water potential) was approximately 0.71 MPa(-1) for the water-storage tissue and the photosynthetic tissue of both daughter cladodes and fruits at 4 weeks of age. When these organs approached maturity at 10 weeks, the relative capacitance increased about 40% for their water-storage tissue, but decreased 30% for their photosynthetic tissue. As the plant water content decreases during drought, about twice as much water will thus be lost per unit volume of the water-storage tissue compared with the photosynthetic tissue of maturing fruits and cladodes. C1 UNIV CALIF LOS ANGELES,DOE LAB,LOS ANGELES,CA 90024. RP NOBEL, PS (reprint author), UNIV CALIF LOS ANGELES,DEPT BIOL,LOS ANGELES,CA 90024, USA. NR 23 TC 30 Z9 30 U1 4 U2 12 PU OXFORD UNIV PRESS UNITED KINGDOM PI OXFORD PA WALTON ST JOURNALS DEPT, OXFORD, ENGLAND OX2 6DP SN 0022-0957 J9 J EXP BOT JI J. Exp. Bot. PD DEC PY 1994 VL 45 IS 281 BP 1801 EP 1807 DI 10.1093/jxb/45.12.1801 PG 7 WC Plant Sciences SC Plant Sciences GA QE954 UT WOS:A1994QE95400002 ER PT J AU PETERSEN, JH GADOMSKI, DM AF PETERSEN, JH GADOMSKI, DM TI LIGHT-MEDIATED PREDATION BY NORTHERN SQUAWFISH ON JUVENILE CHINOOK SALMON SO JOURNAL OF FISH BIOLOGY LA English DT Article; Proceedings Paper CT Fisheries-Society-of-the-British-Isles Annual Symposium on Predator-Prey Relations in Fishes CY JUL 11-15, 1994 CL GLASGOW, SCOTLAND SP FISHERIES SOC BRIT ISLES DE PREDATION; LIGHT INTENSITY; MODELING; NORTHERN SQUAWFISH; PREY SCHOOLING; JUVENILE SALMON ID JOHN-DAY-RESERVOIR; COLUMBIA RIVER; PTYCHOCHEILUS-OREGONENSIS; SMALLMOUTH BASS; SOCKEYE SALMON; MODEL; FISH; BEHAVIOR; WALLEYES; RATES AB Northern squawfish Ptychocheilus oregonensis cause significant mortality of juvenile salmon in the lower Columbia River Basin (U.S.A.). The effects of light intensity on this predator-prey interaction were examined with laboratory experiments and modelling studies. In laboratory experiments, the rate of capture of subyearling chinook salmon Oncorhynchus tshawytscha by northern squawfish was inversely related to light intensity. In a large raceway, about five times more salmon were captured during 4 h periods of relative darkness (0.03 lx) than during periods with high light intensity (160 lx). The rate of predation could be manipulated by increasing or decreasing light intensity. A simulation model was developed for visual predators that encounter, attack, and capture juvenile salmon, whose schooling behaviour was light-sensitive. The model was fitted to laboratory results using a Monte Carlo filtering procedure. Model-predicted predation rate was especially sensitive to the visual range of predators at low light intensity and to predator search speed at high light. Modelling results also suggested that predation by northern squawfish on juvenile salmon may be highest across a narrow window of light intensity. RP PETERSEN, JH (reprint author), NATL BIOL SURVEY, PACIFIC NW NAT SCI CTR, COLUMBIA RIVER RES LAB, COOK, WA 98605 USA. NR 33 TC 24 Z9 29 U1 3 U2 7 PU WILEY-BLACKWELL PI HOBOKEN PA 111 RIVER ST, HOBOKEN 07030-5774, NJ USA SN 0022-1112 EI 1095-8649 J9 J FISH BIOL JI J. Fish Biol. PD DEC PY 1994 VL 45 SU A BP 227 EP 242 DI 10.1111/j.1095-8649.1994.tb01095.x PG 16 WC Fisheries; Marine & Freshwater Biology SC Fisheries; Marine & Freshwater Biology GA PY684 UT WOS:A1994PY68400016 ER PT J AU SNYDER, PB HERRMANN, MC FISCH, NJ AF SNYDER, PB HERRMANN, MC FISCH, NJ TI OPTIMIZATION OF NONTHERMAL FUSION POWER CONSISTENT WITH CHANNELING OF CHARGED FUSION PRODUCT ENERGY SO JOURNAL OF FUSION ENERGY LA English DT Article DE TOKAMAK REACTOR; NON-MAXWELLIAN; ALPHA CHANNELING; D-T REACTOR; D-HE-3 REACTOR AB If the energy of charged fusion products can be diverted directly to fuel ions, non-Maxwellian fuel ion distributions and temperature differences between species will result. To determine the importance of these nonthermal effects, the fusion power density is optimized at constant-beta for nonthermal distributions that are self-consistently maintained by channeling of energy from charged fusion products. For D-T and D-He-3 reactors, with 75% of charged fusion product power diverted to fuel ions, temperature differences between electrons and ions increase the reactivity by 40-70%, while non-Maxwellian fuel ion distributions and temperature differences between ionic species increase the reactivity by an additional 3-15%. RP PRINCETON UNIV, PRINCETON PLASMA PHYS LAB, POB 451, PRINCETON, NJ 08543 USA. NR 15 TC 4 Z9 4 U1 1 U2 3 PU SPRINGER PI NEW YORK PA 233 SPRING ST, NEW YORK, NY 10013 USA SN 0164-0313 EI 1572-9591 J9 J FUSION ENERG JI J. Fusion Energy PD DEC PY 1994 VL 13 IS 4 BP 281 EP 289 DI 10.1007/BF02215848 PG 9 WC Nuclear Science & Technology SC Nuclear Science & Technology GA RU656 UT WOS:A1994RU65600005 ER PT J AU KALMAN, K TSENGCRANK, J DUKES, I CHANDY, G SPENCER, RH HUSTAD, CM COPELAND, NG JENKINS, NA MOHRENWEISER, H BRANDRIFF, B AIYAR, J GUTMAN, GA CHANDY, KG AF KALMAN, K TSENGCRANK, J DUKES, I CHANDY, G SPENCER, RH HUSTAD, CM COPELAND, NG JENKINS, NA MOHRENWEISER, H BRANDRIFF, B AIYAR, J GUTMAN, GA CHANDY, KG TI HEIGHTENED EXPRESSION OF A NOVEL SHAKER-RELATED K+ CHANNEL, KV1.7, IN DIABETIC BETA-CELLS - A CANDIDATE GENE FOR IMPAIRED INSULIN-SECRETION IN DIABETES AND A TARGET FOR NOVEL GLUCOSE-DEPENDENT INSULIN SECRETAGOGUES SO JOURNAL OF GENERAL PHYSIOLOGY LA English DT Meeting Abstract C1 UNIV CALIF IRVINE,DEPT PHYSIOL & BIOPHYS,IRVINE,CA 92717. UNIV CALIF IRVINE,DEPT MICROBIOL & MOLEC GENET,IRVINE,CA 92717. GLAXO RES,DURHAM,NC. MAMMALIAN GEN LABS,ABL BASIC RES PROGRAM,FREDERICK,MD. LAWRENCE LIVERMORE NATL LAB,CTR HUMAN GENOME,LIVERMORE,CA. NR 0 TC 0 Z9 0 U1 0 U2 1 PU ROCKEFELLER UNIV PRESS PI NEW YORK PA 222 E 70TH STREET, NEW YORK, NY 10021 SN 0022-1295 J9 J GEN PHYSIOL JI J. Gen. Physiol. PD DEC PY 1994 VL 104 IS 6 BP A10 EP A10 PG 1 WC Physiology SC Physiology GA PY569 UT WOS:A1994PY56900029 ER PT J AU WINTERHALTER, D NEUGEBAUER, M GOLDSTEIN, BE SMITH, EJ BAME, SJ BALOGH, A AF WINTERHALTER, D NEUGEBAUER, M GOLDSTEIN, BE SMITH, EJ BAME, SJ BALOGH, A TI ULYSSES FIELD AND PLASMA OBSERVATIONS OF MAGNETIC HOLES IN THE SOLAR-WIND AND THEIR RELATION TO MIRROR-MODE STRUCTURES SO JOURNAL OF GEOPHYSICAL RESEARCH-SPACE PHYSICS LA English DT Article ID EARTHS MAGNETOSHEATH; WAVES; INSTABILITY; MAGNETOSPHERE; DEPLETION; SHOCK AB The term ''magnetic hole'' has been used to denote isolated intervals when the magnitude of the interplanetary magnetic field drops to a few tenths, or less, of its ambient value for a time that corresponds to a linear dimension of tens to a few hundreds of proton gyro-radii. Data obtained by the Ulysses magnetometer and solar wind analyzer have been combined to study the properties of such magnetic holes in the solar wind between 1 AU and 5.4 AU and to 23 degrees south latitude. In order to avoid confusion with decreases in field strength at interplanetary discontinuities, the study has focused on linear holes across which the field direction changed by less than 5 degrees. The holes occurred preferentially, but not without exception, in the interaction regions on the leading edges of highspeed solar wind streams. Although the plasma surrounding the holes was generally stable against the mirror instability, there are indications that the holes may have been remnants of mirror-mode structures created upstream of the points of observation. Those indications include the following: (1) For the few holes for which proton or alpha-particle pressure could be measured inside the hole, the ion thermal pressure was always greater than in the plasma adjacent to the holes. (2) The plasma surrounding many of the holes was marginally table for the mirror mode, while the plasma envitonmen?t of all the holes was significantly closer to mirror instability than was the average salar wind. (3) The plasma containing trains of closely spaced holes was closer to mirror instability tl;an was the plasma containing isolated holes. (4) The near-hole plasma had much higher ion beta (ratio of thermal to magnetic pressure) than did the average solar wind. (5) Near the holes, T-perpendicular to/T-II tended tb be either >1 or larger than in the average wind. (6) The proton and alpha-particle distribution function's measured inside the holes occasionally exhibited the flattened phase-space-density contours in nu(perpendicular to)-nu(II) space found in some numerical simulations of the mirror instability. C1 LOS ALAMOS NATL LAB,LOS ALAMOS,NM 87545. UNIV LONDON IMPERIAL COLL SCI & TECHNOL,BLACKETT LAB,LONDON SW7 2BZ,ENGLAND. RP WINTERHALTER, D (reprint author), CALTECH,JET PROP LAB,MS 169-506,4800 OAK GROVE DR,PASADENA,CA, USA. NR 36 TC 131 Z9 133 U1 0 U2 2 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 DEC 1 PY 1994 VL 99 IS A12 BP 23371 EP 23381 DI 10.1029/94JA01977 PG 11 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA PV624 UT WOS:A1994PV62400014 ER PT J AU GARY, SP SCIME, EE PHILLIPS, JL FELDMAN, WC AF GARY, SP SCIME, EE PHILLIPS, JL FELDMAN, WC TI THE WHISTLER HEAT-FLUX INSTABILITY - THRESHOLD CONDITIONS IN THE SOLAR-WIND SO JOURNAL OF GEOPHYSICAL RESEARCH-SPACE PHYSICS LA English DT Article ID THERMAL ELECTRON DISTRIBUTIONS AB Solar wind electrons are observed often to consist of two components: a core and a halo. The anisotropies and relative average speeds of these two components correspond to a heat flux that has the potential to excite several different electromagnetic instabilities; wave-particle scattering by the resulting enhanced fluctuations can limit this heat flux. This manuscript describes theoretical studies using the linear Vlasov dispersion equation for drifting bi-Maxwellian component distributions in a homogeneous plasma to examine the threshold of the whistler heat flux instability. Expressions for this threshold are obtained from two different parametric baselines: a local model that yields scalings as functions of local dimensionless plasma parameters, and a global model based on average electron properties observed during the in-ecliptic phase of the Ulysses mission. The latter model yields an expression for the heat flux at threshold of the whistler instability as a function of heliospheric radius that scales in the same way as the average heat flux observed from Ulysses and that provides an approximate upper bound for that same quantity. This theoretical scaling is combined with the observational results to yield a semiempirical closure relation for the average electron heat flux in the solar wind between 1 and 5 AU. RP GARY, SP (reprint author), LOS ALAMOS NATL LAB,D466,POB 1663,LOS ALAMOS,NM 87545, USA. NR 28 TC 48 Z9 48 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 DEC 1 PY 1994 VL 99 IS A12 BP 23391 EP 23399 DI 10.1029/94JA02067 PG 9 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA PV624 UT WOS:A1994PV62400016 ER PT J AU SCIME, EE BAME, SJ FELDMAN, WC GARY, SP PHILLIPS, JL BALOGH, A AF SCIME, EE BAME, SJ FELDMAN, WC GARY, SP PHILLIPS, JL BALOGH, A TI REGULATION OF THE SOLAR-WIND ELECTRON HEAT-FLUX FROM 1-AU TO 5-AU - ULYSSES OBSERVATIONS SO JOURNAL OF GEOPHYSICAL RESEARCH-SPACE PHYSICS LA English DT Article ID PLASMA-EXPERIMENT; MODELS AB In this study we use observations from the three-dimensional electron spectrometer and magnetometer aboard the Ulysses spacecraft to examine the solar wind electron heat Bur from 1.2 to 5.4 AU in the ecliptic plane. Throughout Ulysses' transit to 5.4 AU, the election heat flux decreases more rapidly (similar to R(-3.0)) than simple collisionless expansion along the local magnetic field and-is smaller than expected for a thermal gradient heat flux, q(lIe)(r)=-K(II)del(II)T(e)(r). The radial gradients and magnitudes expected for a number of electron heat flux regulatory mechanisms are examined and compared to the observations. The best agreement is found for heat flux regulation by the whistler heat flux instability. The upper bound and radial scaling for the electron heat flux predicted for the whistler heat flux instability are consistent with the observations. C1 UNIV LONDON IMPERIAL COLL SCI TECHNOL & MED,BLACKETT LAB,LONDON SW7 2BZ,ENGLAND. RP SCIME, EE (reprint author), LOS ALAMOS NATL LAB,DIV NONPROLIFERAT & INT SECUR,NIS GRP 1,MS D-466,LOS ALAMOS,NM 87545, USA. NR 41 TC 64 Z9 64 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 DEC 1 PY 1994 VL 99 IS A12 BP 23401 EP 23410 DI 10.1029/94JA02068 PG 10 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA PV624 UT WOS:A1994PV62400017 ER PT J AU LIN, NG KELLOGG, PJ THIESSEN, JP LENGYELFREY, D TSURUTANI, BT PHILLIPS, JL AF LIN, NG KELLOGG, PJ THIESSEN, JP LENGYELFREY, D TSURUTANI, BT PHILLIPS, JL TI WHISTLER-MODE WAVES IN THE JOVIAN MAGNETOSHEATH SO JOURNAL OF GEOPHYSICAL RESEARCH-SPACE PHYSICS LA English DT Article ID EARTHS BOW SHOCK; LION ROARS; ULYSSES OBSERVATIONS; IO TORUS; PLASMA; TURBULENCE; JUPITER AB During the Ulysses flyby of Jupiter in February 1992, the spacecraft traversed the Jovian magnetosheath for a few hours during the inbound pass and for a few days during the outbound pass. Burstlike electromagnetic waves at frequencies of similar to 0.1-0.4 of the local electron cyclotron frequency have been observed by the Unified Radio and Plasma Wave (URAP) experiment. The waves were more often observed in the regions which were probably the outer or middle magnetosheath, especially near the bow shock, and rarely seen in the magnetosphere/magnetosheath boundary layer. The propagation angles of the waves are estimated-by comparing the measurements of the wave electric and magnetic fields in the spacecraft spin plane with the corresponding values calculated using the cold plasma dispersion relation under local field and plasma conditions. It is found that the waves propagate obliquely with wave angles between similar to 30 degrees and 50 degrees. These waves are likely to be the whistler mode waves which are excited by suprathermal electrons with a few hundred eV and a slight anisotropy (T-perpendicular to/T-parallel to similar to 1.1-1.5). They are probably similar in nature to the lion roars observed in the Earth's magnetosheath. Signature of coupling between the mirror mode and the whistler mode have also been observed. The plasma conditions which favor the excitation of the whistler mode instability during the wave events exist as observed by the plasma experiment of Ulysses. C1 UNIV MARYLAND,DEPT ASTRON,COLLEGE PK,MD 20742. LOS ALAMOS NATL LAB,LOS ALAMOS,NM 87545. CALTECH,JET PROP LAB,PASADENA,CA 91109. RP LIN, NG (reprint author), UNIV MINNESOTA,SCH PHYS & ASTRON,116 CHURCH ST SE,MINNEAPOLIS,MN 55455, USA. NR 33 TC 5 Z9 5 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 DEC 1 PY 1994 VL 99 IS A12 BP 23527 EP 23539 DI 10.1029/94JA01998 PG 13 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA PV624 UT WOS:A1994PV62400030 ER PT J AU LOPEZ, RE GOODRICH, CC REEVES, GD BELIAN, RD TAKTAKISHVILI, A AF LOPEZ, RE GOODRICH, CC REEVES, GD BELIAN, RD TAKTAKISHVILI, A TI MIDTAIL PLASMA FLOWS AND THE RELATIONSHIP TO NEAR-EARTH SUBSTORM ACTIVITY - A CASE-STUDY SO JOURNAL OF GEOPHYSICAL RESEARCH-SPACE PHYSICS LA English DT Article ID ENERGETIC PARTICLE MEASUREMENTS; MAGNETIC-FIELD; CURRENT WEDGE; CURRENT DISRUPTION; SHEET; MAGNETOTAIL; EXPANSION; ONSET; MAGNETOSPHERE; RECONNECTION AB Recent simulations of magnetotail reconnection have pointed to a link between plasma flows, dipolarization, and the substorm current wedge. In particular, Hesse and Birn (1991) have proposed that earthward jetting of plasma from the reconnection region transports flux into the near-Earth region. At the inner edge of the plasma sheet this flux piles up, producing a dipolarization of the magnetic field. The vorticity produced by the east-west deflection of the flow at the inner edge of the plasma sheet gives rise to field-aligned currents that have region 1 polarity. Thus in this scenario the earthward flow from the reconnection region produces the dipolarization and the current wedge in a self-consistent fashion. In this study we examine observations made on April 8, 1985 by the Active Magnetospheric Particle Tracer Explorers/Ion Release Module (IRM), the geosynchronous satellites 1979-053, 1983-019, and 1984-037, and Syowa station, as well as AE. This event is unique because IRM was located near the neutral sheet in the midnight sector for an extended period of time. Ground data show that there was ongoing activity in the IRM local time sector for several hours, beginning at 1800 UT and reaching a crescendo at 2300 UT. This activity was also accompanied by energetic particle variations, including injections, at geosynchronous orbit in the nighttime sector. Significantly, there were no fast flows at the neutral sheet until the great intensification of activity at 2300 UT. At that time, IRM recorded fast earthward flow simultaneous with a dipolarization of the magnetic field. We conclude that while the aforementioned scenario for the creation of the current wedge encounters serious problems explaining the earlier activity, the observations at 2300 UT are consistent with the scenario of Hesse and Birn (1991). On that basis it is argued that the physics of substorms is not exclusively rooted in the development of a global tearing mode. Processes at the inner edge of cross-tail current that cause a disruption of the current and a consequent dipolarization and current wedge may be unrelated to the formation of a macroscale reconnection region. Thus the global evolution of a substorm is probably a complicated superposition of such processes operating on a very localized scale and a global macroscale process that allows for such things as releasing the energy stored in lobe flux and the creation of plasmoids. C1 LOS ALAMOS NATL LAB, LOS ALAMOS, NM USA. ABASTUMANI ASTROPHYS LAB, TBILISI, REP OF GEORGIA. RP UNIV MARYLAND, DEPT ASTRON, COLLEGE PK, MD 20742 USA. RI Reeves, Geoffrey/E-8101-2011; OI Reeves, Geoffrey/0000-0002-7985-8098; Lopez, Ramon/0000-0001-5881-1365 NR 40 TC 21 Z9 21 U1 0 U2 0 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 2169-9380 EI 2169-9402 J9 J GEOPHYS RES-SPACE JI J. Geophys. Res-Space Phys. PD DEC 1 PY 1994 VL 99 IS A12 BP 23561 EP 23569 DI 10.1029/94JA01771 PG 9 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA PV624 UT WOS:A1994PV62400033 ER PT J AU NAKAMURA, R BAKER, DN FAIRFIELD, DH MITCHELL, DG MCPHERRON, RL HONES, EW AF NAKAMURA, R BAKER, DN FAIRFIELD, DH MITCHELL, DG MCPHERRON, RL HONES, EW TI PLASMA-FLOW AND MAGNETIC-FIELD CHARACTERISTICS NEAR THE MIDTAIL NEUTRAL SHEET SO JOURNAL OF GEOPHYSICAL RESEARCH-SPACE PHYSICS LA English DT Article ID EARTHS MAGNETOTAIL; EQUATORIAL MAGNETOTAIL; ION COMPOSITION; SUBSTORM; RECONNECTION; MAGNETOSPHERE; AMPTE/CCE; MODEL; OVAL; RE AB Using IMP 6, 7, and 8 magnetic field and plasma data, we have determined statistical occurrence properties of bulk flow and magnetic field orientation near the midtail. neutral sheet. Characteristics of bulk plasma flow and magnetic field significantly change according to the radial distance down the tail. High-speed flow events (V > 300 km/s) are essentially restricted to the region tailward of X = -25 R(E) and are predominantly sunward or tailward. The low-speed flows were nearly equally likely to be in any direction, with the occurrence rate of duskward and sunward flow being larger than that of tailward and dawnward flow. Duskward now occurrence is highest in the region Earthward of X = -25 R(E), while sunward flow occurrence is highest in the region tailward of X = -25 R(E). The significance of the dawn-to-dusk flow in the near-Earth region obtained in our study supports the idea that there exists a very effective mechanism to accelerate ions in the dawn-to-dusk direction and hence the relief of pressure buildup in the near-Earth region. During high-speed flow events the relationship between B-Z polarity and plasma flow direction is largely consistent with that expected from the magnetic reconnection processes associated with substorms. There are also significant numbers of negative B-Z events that are not associated with tailward flow. Mechanism other than substorm neutral line should therefore also taken into account to explain general B-Z polarity in the midtail region. C1 NASA,GODDARD SPACE FLIGHT CTR,GREENBELT,MD 20771. JOHNS HOPKINS UNIV,APPL PHYS LAB,LAUREL,MD. UNIV CALIF LOS ANGELES,INST GEOPHYS & PLANETARY PHYS,LOS ANGELES,CA 90024. LOS ALAMOS NATL LAB,LOS ALAMOS,NM. RP NAKAMURA, R (reprint author), NAGOYA UNIV,SOLAR TERR ENVIRONM LAB,3-13 HONOHARA,TOYOKAWA,AICHI 442,JAPAN. RI Nakamura, Rumi/I-7712-2013 OI Nakamura, Rumi/0000-0002-2620-9211 NR 40 TC 33 Z9 33 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 DEC 1 PY 1994 VL 99 IS A12 BP 23591 EP 23601 DI 10.1029/94JA02082 PG 11 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA PV624 UT WOS:A1994PV62400036 ER PT J AU GARY, SP MOLDWIN, MB THOMSEN, MF WINSKE, D MCCOMAS, DJ AF GARY, SP MOLDWIN, MB THOMSEN, MF WINSKE, D MCCOMAS, DJ TI HOT PROTON ANISOTROPIES AND COOL PROTON TEMPERATURES IN THE OUTER MAGNETOSPHERE SO JOURNAL OF GEOPHYSICAL RESEARCH-SPACE PHYSICS LA English DT Article ID ION-CYCLOTRON WAVES; 1-2 MAGNETIC PULSATIONS; EQUATORIAL MAGNETOSPHERE; EARTHS MAGNETOSPHERE; SYNCHRONOUS ORBIT; PLASMA; INSTABILITIES; MAGNETOSHEATH; SIMULATIONS; HE+ AB The hot protons of the outer magnetosphere typically exhibit a temperature anisotropy such that T-perpendicular to/T-parallel to > 1, where perpendicular and parallel symbols denote directions relative to the background-magnetic field. If this anisotropy is sufficiently large, the electromagnetic proton cyclotron anisotropy instability may be excited. This instability is studied using linear Vlasov theory and one-dimensional hybrid simulations for a homogeneous plasma model representative of conditions in the outer magnetosphere with a hot anisotropic proton component (denoted by subscript h) and a cool, initially isotropic proton component (subscript c). Linear theory yields an instability threshold condition on the hot proton temperature anisotropy whereas the simulations imply an upper bound on T-perpendicular to h/T-parallel to h; both the threshold and the upper bound have similar scalings with the maximum growth rate gamma(m), the parallel beta of the hot component, beta(parallel to h), and the relative density of the hot component n(h)/n(e). An analysis of plasma observations from the Los Alamos magnetospheric plasma analyzer (MPA) in geosynchronous orbit finds that the maximum value of the hot proton temperature anisotropy approximately satisfies the predicted scalings with beta(parallel to h) and n(h)/n(e) and yields the proportionality factor that quantifies this upper bound. The simulations are also used to examine the heating of the cool protons by the proton cyclotron instability. The simulations yield a scaling for the dimensionless late-time cool proton average temperature T-c/T-parallel to h as (n(h)/n(e))/beta(parallel to h)(0.5). Analysis of MPA data shows that the observed values of T-c/T-parallel to h have similar scalings and again yield the proportionality factor which quantifies this relationship. RP GARY, SP (reprint author), LOS ALAMOS NATL LAB,MS D466,LOS ALAMOS,NM 87545, USA. RI Moldwin, Mark/F-8785-2011 OI Moldwin, Mark/0000-0003-0954-1770 NR 58 TC 49 Z9 50 U1 0 U2 3 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 SN 0148-0227 J9 J GEOPHYS RES JI J. Geophys. Res-Space Phys. PD DEC 1 PY 1994 VL 99 IS A12 BP 23603 EP 23615 DI 10.1029/94JA02069 PG 13 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA PV624 UT WOS:A1994PV62400037 ER PT J AU WALTHOUR, DW GOSLING, JT SONNERUP, BUO RUSSELL, CT AF WALTHOUR, DW GOSLING, JT SONNERUP, BUO RUSSELL, CT TI OBSERVATION OF ANOMALOUS SLOW-MODE SHOCK AND RECONNECTION LAYER IN THE DAYSIDE MAGNETOPAUSE SO JOURNAL OF GEOPHYSICAL RESEARCH-SPACE PHYSICS LA English DT Article ID NONCOPLANAR MAGNETIC-FIELDS; ANISOTROPIC-PLASMA; EARTHS MAGNETOPAUSE; ROTATIONAL DISCONTINUITIES; INTERMEDIATE SHOCKS; GEOMAGNETIC TAIL; SOLAR-WIND; ISEE 1 AB Plasma and magnetic field data from the ISEE 2 spacecraft recorded during an outbound crossing of the dayside, northern hemisphere magnetopause on October 29, 1979, provide evidence for a slow shock (SS) in the observed reconnection layer. This layer is found to be bounded on the magnetosheath side by the SS; near the magnetospheric side of the layer, a second current sheet is found that may have been a rotational discontinuity (RD). The direction of the accelerated plasma flow, the earthward sense of the normal magnetic field across the SS and RD, and the relative orientation of the SS and the RD all indicate that the reconnection site was located south of the spacecraft. Quantitative tests show that, allowing for experimental uncertainties, data taken upstream and downstream of the SS are consistent with coplanarity and other Rankine-Hugoniot (RH) conditions. Examination of the flow parameters indicates two anomalous properties of the SS: the upstream flow, viewed in the deHoffmann-Teller frame, is superalfvenic and the downstream plasma is firehose unstable. In comparison to the long-wavelength slow-mode phase speed, however, the flow in the upstream region is super slow, while in the downstream region it is subslow, as required for a slow-mode shock. Further properties of the shock include a large decrease in total enthalpy across it, indicating the escape of a sizable heat flux from the shock structure, and the occurrence of a polarization reversal of the tangential magnetic field within the shock layer, a feature that is predicted by linear double-polytropic Hall-MHD and results from a large increase in pressure anisotropy from the upstream region, where p(parallel to) congruent to p(perpendicular to) to the downstream region, where p(parallel to) > p(perpendicular to) . Quantitative tests of the RD-like discontinuity show that it satisfies the necessary RH conditions within experimental uncertainties and indicate that the flow across it is earthward, that is, it is the same as for the SS. Thus the RD is propagating behind the SS in the direction away from the Earth. This reversal in the order of the discontinuities is attributed to the reversal of the slow and intermediate phase speeds produced by the pressure anisotropy in the region between the RD and the SS. The linear dispersion relation and polarization properties of dispersive MHD waves in an anisotropic plasma are examined in the appendix. C1 DARTMOUTH COLL,THAYER SCH ENGN,HANOVER,NH 03755. LOS ALAMOS NATL LAB,LOS ALAMOS,NM. UNIV CALIF LOS ANGELES,INST GEOPHYS & PLANETARY PHYS,LOS ANGELES,CA 90024. NR 37 TC 27 Z9 27 U1 4 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 DEC 1 PY 1994 VL 99 IS A12 BP 23705 EP 23722 DI 10.1029/94JA01767 PG 18 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA PV624 UT WOS:A1994PV62400046 ER PT J AU LE, G RUSSELL, CT GOSLING, JT AF LE, G RUSSELL, CT GOSLING, JT TI STRUCTURE OF THE MAGNETOPAUSE FOR LOW MACH NUMBER AND STRONGLY NORTHWARD INTERPLANETARY MAGNETIC-FIELD SO JOURNAL OF GEOPHYSICAL RESEARCH-SPACE PHYSICS LA English DT Article ID LATITUDE BOUNDARY-LAYER; SUBSOLAR MAGNETOPAUSE; EARTHS MAGNETOPAUSE; PLASMA; RECONNECTION; MAGNETOSPHERE; WAVES; SHEAR; MAGNETOSHEATH; MAGNETOTAIL AB We use ISEE magnetic field and plasma data to examine dayside magnetopause crossings under conditions of low Mach number and strongly northward interplanetary magnetic field (IMF). When the solar wind Mach number is low, the IMF strength and magnetosheath field strength are large, and we expect the effects of magnetic reconnection to be the strongest. When the IMF is strongly northward, we find that the location of the magnetopause boundary layer is very stationary in the space, and we observe many features that are common for both typical and low Mach numbers. However, under low Mach number conditions, we have observed some features that would be expected for cusp reconnection. The boundary layer near the subsolar region contains heated magnetosheath plasma with little hot magnetospheric component that has clearly entered the magnetosphere elsewhere. At least some of the structures present in the boundary layer are impulsive. Inside the boundary layer there is also clear evidence of accelerated flow from the cusp region for strongly northward IMF at low Mach number. Reconnection beyond the cusp can explain the observed field, plasma, and flow signatures. Therefore at low Mach number, reconnection is important in the formation of the boundary layer for northward IMF. C1 LOS ALAMOS NATL LAB,LOS ALAMOS,NM. RP LE, G (reprint author), UNIV CALIF LOS ANGELES,INST GEOPHYS & PLANETARY PHYS,LOS ANGELES,CA 90024, USA. RI Le, Guan/C-9524-2012 OI Le, Guan/0000-0002-9504-5214 NR 35 TC 20 Z9 20 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 DEC 1 PY 1994 VL 99 IS A12 BP 23723 EP 23734 DI 10.1029/94JA02182 PG 12 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA PV624 UT WOS:A1994PV62400047 ER PT J AU FIEGEL, GL KUTTER, BL AF FIEGEL, GL KUTTER, BL TI LIQUEFACTION-INDUCED LATERAL SPREADING OF MILDLY SLOPING GROUND SO JOURNAL OF GEOTECHNICAL ENGINEERING-ASCE LA English DT Note AB Dynamic centrifuge modeling was used to study the behavior of two mildly sloping ground models subjected to earthquake lending and liquefaction. The first model consisted of a uniform layer of saturated sand, and the second consisted of a layer of sand overlain by a relatively impermeable layer of nonplastic silt; both model slopes were constructed at an angle of 2.6 degrees. Time histories of acceleration. excess pore water pressure. and displacement are presented with photographs to illustrate the mechanisms of failure. In both tests approximately 0.8 m of prototype lateral displacement was measured at the surface. In the uniform sand model this lateral displacement was distributed throughout much of the layer: however, in the layered model displacement was concentrated along the interface between soil layers. The concentration of displacement is consistent with a reduction in the sliding resistance between the silt and the sand layers due to the redistribution of voids at the interface, This possibility of redistribution of voids indicates that care must be taken when using undrained strengths in the postliquefaction analysis of layered slopes. RP FIEGEL, GL (reprint author), LAWRENCE LIVERMORE NATL LAB,DEPT CIV & ENVIR ENGRG,DAVIS,CA 95616, USA. RI Kutter, Bruce/A-6215-2011 OI Kutter, Bruce/0000-0002-0628-1275 NR 15 TC 20 Z9 21 U1 0 U2 3 PU ASCE-AMER SOC CIVIL ENGINEERS PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017-2398 SN 0733-9410 J9 J GEOTECH ENG-ASCE JI J. Geotech. Eng.-ASCE PD DEC PY 1994 VL 120 IS 12 BP 2236 EP 2243 DI 10.1061/(ASCE)0733-9410(1994)120:12(2236) PG 8 WC Engineering, Civil; Geosciences, Multidisciplinary SC Engineering; Geology GA PT787 UT WOS:A1994PT78700009 ER PT J AU TUBERVILLE, TD BURKE, VJ AF TUBERVILLE, TD BURKE, VJ TI DO FLAG MARKERS ATTRACT TURTLE NEST PREDATORS SO JOURNAL OF HERPETOLOGY LA English DT Note ID DEPREDATION; EDGE RP TUBERVILLE, TD (reprint author), UNIV GEORGIA,SAVANNAH RIVER ECOL LAB,DRAWER E,AIKEN,SC 29802, USA. NR 7 TC 21 Z9 23 U1 0 U2 2 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 DEC PY 1994 VL 28 IS 4 BP 514 EP 516 DI 10.2307/1564971 PG 3 WC Zoology SC Zoology GA QA125 UT WOS:A1994QA12500022 ER PT J AU TAYFUR, G KAVVAS, ML AF TAYFUR, G KAVVAS, ML TI SPATIALLY AVERAGED CONSERVATION EQUATIONS FOR INTERACTING RILL-INTERRILL AREA OVERLAND FLOWS SO JOURNAL OF HYDRAULIC ENGINEERING-ASCE LA English DT Article ID VENANT EQUATIONS; HILLSLOPES; EROSION; DEPTH AB The modeling of flows at hillslope scale over land surfaces that contain rills and interrill areas is presented. The now in fills is treated as one-dimensional ''channel flow.'' The flow at interrill areas is treated as two-dimensional ''sheet flow.'' Sheet-flow equations are averaged along the interrill area width (local averaging) to account for the interaction between interrill and rill sections. The now depth at the interrill area outlet section is derived by assuming that the flow profile of the interrill area section has the profile of a sine function. To minimize computational efforts and economize on the number of model parameters, locally averaged rill and sheet-now equations are then averaged over the transects of a hillsope (large-scale averaging). The expectations of the terms containing more than one variable are obtained through the Taylor series expansion around their mean values, Only the first two moments of the series expansion are considered. The results of the model are in good agreement with the field observations. The effects of average local slopes and rill occurrence probability on now rates are shown To be quite pronounced. On a rilled surface, most of the flow occurs in rill sections. Comparisons of model results with observed results over experimental hillslopes are satisfactory. RP TAYFUR, G (reprint author), LAWRENCE LIVERMORE NATL LAB, DEPT CIVIL & ENVIRONM ENGN, DAVIS, CA 95616 USA. NR 22 TC 25 Z9 27 U1 1 U2 4 PU ASCE-AMER SOC CIVIL ENGINEERS PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017-2398 SN 0733-9429 J9 J HYDRAUL ENG-ASCE JI J. Hydraul. Eng.-ASCE PD DEC PY 1994 VL 120 IS 12 BP 1426 EP 1448 DI 10.1061/(ASCE)0733-9429(1994)120:12(1426) PG 23 WC Engineering, Civil; Engineering, Mechanical; Water Resources SC Engineering; Water Resources GA PT784 UT WOS:A1994PT78400006 ER PT J AU EPSTEIN, D RAMIREZ, JA AF EPSTEIN, D RAMIREZ, JA TI SPATIAL DISAGGREGATION FOR STUDIES OF CLIMATIC HYDROLOGIC SENSITIVITY SO JOURNAL OF HYDRAULIC ENGINEERING-ASCE LA English DT Article AB The use of deterministic atmospheric general circulation models (GCMs) to understand potential global climate change under doubled CO2 forcing has prompted a need for better understanding of local hydrologic impacts. Incongruities in model resolutions do not allow for GCM output to be directly used as forcing in the smaller-scale hydrologic models. In this work, daily spatial disaggregation techniques are applied to the upper Rio Grande basin in Colorado, simulating local temperature and precipitation regimes, and preserving spatial covariance structures at all spatial scales. Canadian Climate Centre GCM output is disaggregated to site-specific locations within the study basin. The Precipitation Runoff Modeling System is then used to examine hydrologic sensitivity under the disaggregated climate forcing. The results from this sensitivity indicate that under spatially disaggregated, site-specific, climatic forcing, significant snowpack-accumulation decreases occur. This results in total annual runoff decreases of, on average, 17.7%. A seasonal shift toward earlier in the year is observed in peak runoff, soil moisture storage, and evapotranspiration. C1 COLORADO STATE UNIV, DEPT CIVIL ENGN, HYDRO SCI & ENGN PROGRAM, FT COLLINS, CO 80523 USA. RP EPSTEIN, D (reprint author), PACIFIC NW LAB, BOX 999,MAIL STOP K6-77, RICHLAND, WA 99352 USA. NR 27 TC 16 Z9 16 U1 0 U2 3 PU ASCE-AMER SOC CIVIL ENGINEERS PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017-2398 SN 0733-9429 J9 J HYDRAUL ENG-ASCE JI J. Hydraul. Eng.-ASCE PD DEC PY 1994 VL 120 IS 12 BP 1449 EP 1467 DI 10.1061/(ASCE)0733-9429(1994)120:12(1449) PG 19 WC Engineering, Civil; Engineering, Mechanical; Water Resources SC Engineering; Water Resources GA PT784 UT WOS:A1994PT78400007 ER PT J AU ANDRICEVIC, R DANIELS, JI JACOBSON, RL AF ANDRICEVIC, R DANIELS, JI JACOBSON, RL TI RADIONUCLIDE MIGRATION USING A TRAVEL-TIME TRANSPORT APPROACH AND ITS APPLICATION IN RISK ANALYSIS SO JOURNAL OF HYDROLOGY LA English DT Article ID HETEROGENEOUS POROUS-MEDIA; TRANSFER-FUNCTION MODEL; SOLUTE TRANSPORT; AQUIFERS; COEFFICIENTS; GROUNDWATER; DISPERSION; ARRIVAL; SOIL AB The travel time transport approach for radioactive elements undergoing sorption and decay is employed in assessing the potential health risk at possible locations of human receptors. The principal entity in approach presented is a travel time probability density function conditioned on the set of parameters used to describe different transport processes, like advection, dispersion, sorption, and decay. The importance of accounting for parameter uncertainty and possible correlation between them is described and demonstrated in the study of risk analysis at the Nevada Test Site (NTS), which is located in the southwestern part of the state of Nevada. Because of the lack of sorption, the migration of tritium is found to provide the largest health risk to the accessible environment. Inclusion of the sorption process indicates that the parameter uncertainty and especially negative correlation between the mean velocity and the sorption strength are important in evaluating the arrival time of radionuclides at the prespecified accessible environment. The results from the risk-based screening analysis suggest that tritium, which does not sorb and has a short effective half-life (both physical and biological), is responsible for about 90% of the total risk. C1 LAWRENCE LIVERMORE NATL LAB,DIV ENVIRONM SCI,LIVERMORE,CA 94551. RP ANDRICEVIC, R (reprint author), UNIV NEVADA,DESERT RES INST,CTR WATER RESOURCES,LAS VEGAS,NV 89132, USA. NR 32 TC 20 Z9 20 U1 1 U2 3 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0022-1694 J9 J HYDROL JI J. Hydrol. PD DEC 1 PY 1994 VL 163 IS 1-2 BP 125 EP 145 DI 10.1016/0022-1694(94)90026-4 PG 21 WC Engineering, Civil; Geosciences, Multidisciplinary; Water Resources SC Engineering; Geology; Water Resources GA QA087 UT WOS:A1994QA08700008 ER PT J AU LEONG, KH HOLDRIDGE, DJ SABO, KR AF LEONG, KH HOLDRIDGE, DJ SABO, KR TI CHARACTERISTICS OF POWER METERS FOR HIGH-POWER CO2-LASERS SO JOURNAL OF LASER APPLICATIONS LA English DT Article DE CO2 LASER; LASER BEAM MEASUREMENT AB Four different instruments used for measuring CO2 laser beam power in the kilowatt range were evaluated. The techniques used to determine the laser beam power included temperature increase from an absorber of known mass and specific heat, temperature increase from a steady flow of water used to cool the absorber, thermal gradient caused by edge-cooling a circular absorber, and diffuse scattering from a small portion of the water-cooled absorber surface. The parameters evaluated included response time, repeatability, sensitivity to position of the incident laser beam and beam mode, and linearity of response. The accuracies of the instruments were not determined as no NIST standard exists. Response times varied from 1 to 15 s. Each instrument had good reproducibility in indicated power values. Some meters exhibited sensitivity to beam mode, diameter, and position. All meters had very good to excellent linearity in response. Comparison of the indicated power values showed that each instrument tended to give slightly different values. For the range 400-6000 W the indicated power values from all meters differed by <15% from the mean value. RP LEONG, KH (reprint author), UNIV CHICAGO,ARGONNE NATL LAB,LASER APPLICAT LAB,CHICAGO,IL 60439, USA. NR 2 TC 1 Z9 1 U1 0 U2 0 PU LASER INST AMER PI ORLANDO PA 12424 RESEARCH PARKWAY SUITE 125, ORLANDO, FL 32826 SN 1042-346X J9 J LASER APPL JI J. Laser Appl. PD DEC PY 1994 VL 6 IS 4 BP 231 EP 236 PG 6 WC Materials Science, Multidisciplinary; Optics; Physics, Applied SC Materials Science; Optics; Physics GA PY544 UT WOS:A1994PY54400010 ER PT J AU BARAT, K KELLY, SE AF BARAT, K KELLY, SE TI EXPOSURE TO LESSONS LEARNED - A TOOL FOR LASER SAFETY SO JOURNAL OF LASER APPLICATIONS LA English DT Article DE LASER SAFETY; ACCIDENT INVESTIGATION AB This article outlines the value and steps to follow for establishing a ''lessons learned program'', with specific application to a laser safety program. As a communication tool and preventive measure for laser safety issues, the program is an effective means of turning accident investigation into a proactive rather than a reactive exercise by emphasizing corrective rather than disciplinary (looking for someone to blame) actions. RP BARAT, K (reprint author), LAWRENCE BERKELEY LAB,DIV ENVIRONM HLTH & SAFETY,BERKELEY,CA 94720, USA. NR 0 TC 0 Z9 0 U1 1 U2 2 PU LASER INST AMER PI ORLANDO PA 12424 RESEARCH PARKWAY SUITE 125, ORLANDO, FL 32826 SN 1042-346X J9 J LASER APPL JI J. Laser Appl. PD DEC PY 1994 VL 6 IS 4 BP 241 EP 243 PG 3 WC Materials Science, Multidisciplinary; Optics; Physics, Applied SC Materials Science; Optics; Physics GA PY544 UT WOS:A1994PY54400012 ER PT J AU OMEARA, NM CABANA, VG LUKENS, JR LOHARIKAR, B FORTE, TM POLONSKY, KS GETZ, GS AF OMEARA, NM CABANA, VG LUKENS, JR LOHARIKAR, B FORTE, TM POLONSKY, KS GETZ, GS TI HEPARIN-INDUCED LIPOLYSIS IN HYPERTRIGLYCERIDEMIC SUBJECTS RESULTS IN THE FORMATION OF ATYPICAL HDL PARTICLES SO JOURNAL OF LIPID RESEARCH LA English DT Article DE FREE FATTY ACID; POSTHEPARIN LIPASE; SMALL BUT LIGHT HDL PARTICLES ID HIGH-DENSITY-LIPOPROTEIN; APO-A-I; CHOLESTEROL LEVELS; HEART-DISEASE; PLASMA-LIPOPROTEIN; LIPASE ACTIVITY; METABOLISM; APOLIPOPROTEINS; PROTEIN; LIPIDS AB This study reports on the characterization of high density lipoprotein (HDL) in normotriglyceridemic and hypertriglyceridemic (HTG) subjects, after a fat meal and heparin-induced release of lipases. Samples for detailed analysis of HDL by density gradient ultracentrifugation and nondenaturing gradient gel electrophoresis were collected at 0 h and 5 h after the meal and 15 min after the administration of heparin. The normotriglyceridemic subjects were subdivided into two groups: those who remained normotriglyceridemic 5 h after the meal (NTG) or those who were hypertriglyceridemic at this time point (NTG-HTG). At the outset of the study, mean triglyceride levels were significantly higher (P < 0.001) and HDL cholesterol levels lower (P < 0.02) in the HTG group. The HDL particles in this group were enriched with triglyceride (P < 0.001). Serum triglyceride levels rose in all three groups after the fat meal and this was associated with further triglyceride enrichment of the HDL particles. In all groups, rapid lipolysis induced by heparin caused a significant decrease in plasma triglycerides and increase in free fatty acid levels, these changes being greatest in the HTG group. HDL density profiles of the study groups prior to the administration of heparin demonstrated two distinct peaks at density 1.09 g/ml (HDL(2)) and 1.13 g/ml (HDL(3)). However, after the administration of heparin to the HTG group, only a single peak in the HDL profile was evident that was located at the density region corresponding to HDL, (1.09 g/ml). Upon gradient gel electrophoresis of this peak, there was an increased number (P < 0.005 vs. NTG) of small particles (<4.37 nm) whose size was similar to the size range normally associated with HDL(3b) and HDL(3c). Similar changes in HDL density and size after the administration of heparin were observed in the NTG-HTG group who were also hypertriglyceridemic postprandially. By contrast, the density gradient profiles and sizes of the HDL particles did not change after the administration of heparin to NTG subjects. Thus, the activation of lipolysis in HTG subjects leads to the generation of atypical HDL particles that are small but of reduced density. Rapid clearance of such particles could account for the inverse relationship between triglyceride and HDL cholesterol in this population subgroup. C1 UNIV CHICAGO,PRITZKER SCH MED,DEPT PATHOL,CHICAGO,IL 60637. UNIV CHICAGO,PRITZKER SCH MED,DEPT MED,CHICAGO,IL 60637. UNIV CALIF BERKELEY,LAWRENCE BERKELEY LAB,DEPT MOLEC & NUCL MED,DIV LIFE SCI,BERKELEY,CA 94720. FU NHLBI NIH HHS [HL-18574, HL-15062-21]; NIDDK NIH HHS [DK-31842] NR 28 TC 15 Z9 15 U1 0 U2 0 PU LIPID RESEARCH INC PI BETHESDA PA 9650 ROCKVILLE PIKE, BETHESDA, MD 20814-3998 SN 0022-2275 J9 J LIPID RES JI J. Lipid Res. PD DEC PY 1994 VL 35 IS 12 BP 2178 EP 2190 PG 13 WC Biochemistry & Molecular Biology SC Biochemistry & Molecular Biology GA PZ293 UT WOS:A1994PZ29300008 PM 7897316 ER PT J AU LIU, AC LAWN, RM VERSTUYFT, JG RUBIN, EM AF LIU, AC LAWN, RM VERSTUYFT, JG RUBIN, EM TI HUMAN APOLIPOPROTEIN-A-I PREVENTS ATHEROSCLEROSIS ASSOCIATED WITH APOLIPOPROTEIN[A] IN TRANSGENIC MICE SO JOURNAL OF LIPID RESEARCH LA English DT Article DE LIPOPROTEIN[A]; HIGH DENSITY LIPOPROTEIN ID HIGH-DENSITY-LIPOPROTEIN; EXPRESSING HUMAN APOLIPOPROTEIN(A); CHOLESTEROL; ATHEROGENESIS; LESIONS AB Elevated levels of apolipoprotein[a] (apo[a]) and apolipoprotein A-I (apoA-I) are associated, respectively, with increased and decreased atherosclerosis risk, in both humans and transgenic mice. To investigate the interactions of these two important lipid-associated proteins, we assessed the effect of expression of human apoA-I and apo[a] transgenes, both singularly and together, on murine atherogenesis, Mice expressing the apo[a] transgene have a lipoprotein profile similar to nontransgenic controls, yet have significantly increased susceptibility to diet-induced atherosclerosis. Compared to mice expressing only the apo[a] transgene, mice expressing both apo[a] and apoA-I transgenes have twofold greater high density lipoprotein (HDL) concentrations and approximately a 20-fold decrease in development of early atherosclerotic lesions. The finding of decreased atherosclerosis in the setting of elevated apo[a] and apoA-I suggests that elevations of apoA-I and HDL have a dominant effect in reducing atherosclerosis susceptibility in various settings, including those not associated with alterations of plasma lipids. C1 UNIV CALIF BERKELEY,CTR HUMAN GENOME,LAWRENCE BERKELEY LAB,BERKELEY,CA 94720. STANFORD UNIV,SCH MED,DIV CARDIOVASC MED,STANFORD,CA 94305. FU NHLBI NIH HHS [HL08733-02, HL18574]; OAPP OPHS HHS [PPG48638-01] NR 23 TC 89 Z9 96 U1 0 U2 2 PU LIPID RESEARCH INC PI BETHESDA PA 9650 ROCKVILLE PIKE, BETHESDA, MD 20814-3998 SN 0022-2275 J9 J LIPID RES JI J. Lipid Res. PD DEC PY 1994 VL 35 IS 12 BP 2263 EP 2267 PG 5 WC Biochemistry & Molecular Biology SC Biochemistry & Molecular Biology GA PZ293 UT WOS:A1994PZ29300016 PM 7897323 ER PT J AU ZHU, LM REID, BR KENNEDY, M DROBNY, GP AF ZHU, LM REID, BR KENNEDY, M DROBNY, GP TI MODULATION OF J-COUPLINGS BY CROSS-RELAXATION IN DNA SUGARS SO JOURNAL OF MAGNETIC RESONANCE SERIES A LA English DT Article ID NUCLEAR-MAGNETIC-RESONANCE; NMR-SPECTROSCOPY; CONFORMATIONAL-ANALYSIS; CONSTANTS; DODECAMER; DYNAMICS; PUCKER; ACIDS; RING AB The spin dynamics and multiplet structure of three scalar coupled protons have been calculated by solving the complete Liouville master equation. The spin system selected for study was chosen to model the H1'-H2'R-H2'S protons of a deoxyribose ring in a B-form DNA duplex. In the long-correlation-time limit, when two of the three spins are very close to each other (as is the case for the H2'R/H2'S geminal pair), the multiplet splittings of a third spin (e.g., H1') that is scalar coupled to that geminal pair are modulated by transverse cross relaxation; furthermore, theory predicts that the phases of the multiplet components are also affected by transverse cross relaxation. Our results indicate that, in the case of a DNA duplex undergoing rotational diffusion with a correlation time longer than similar to 2 nanoseconds, the measured apparent proton-proton J coupling constants of a spin that is coupled to a geminal proton pair cannot be used to determine the sugar conformation via a simple Karplus-type relationship because these cross-relaxation effects perturb the apparent J splitting. A specific experimental example is presented that illustrates the apparent contradictions and false conclusions that can result from not considering transverse cross relaxation. The cross-relaxation effects are generally ignored, and, because of this, the fact that the measured apparent J couplings cannot be fitted to a single sugar conformer using current calibrations of Karplus coefficients does not necessarily indicate an equilibrium between different conformational states of the furanose ring. (C) 1994 Academic Press,Inc. C1 UNIV WASHINGTON, DEPT BIOCHEM, SEATTLE, WA 98195 USA. PACIFIC NW LAB, RICHLAND, WA 99352 USA. RP ZHU, LM (reprint author), UNIV WASHINGTON, DEPT CHEM, SEATTLE, WA 98195 USA. NR 29 TC 23 Z9 23 U1 0 U2 2 PU ACADEMIC PRESS INC JNL-COMP SUBSCRIPTIONS PI SAN DIEGO PA 525B STREET, SUITE 1900, SAN DIEGO, CA 92101-4495 SN 1064-1858 J9 J MAGN RESON SER A JI J. Magn. Reson. Ser. A PD DEC PY 1994 VL 111 IS 2 BP 195 EP 202 DI 10.1006/jmra.1994.1247 PG 8 WC Physics, Atomic, Molecular & Chemical SC Physics GA QC815 UT WOS:A1994QC81500009 ER PT J AU LUO, JS MERCHANT, N ESCORCIAAPARICIO, EJ MARONI, VA TANI, BS CARTER, WL RILEY, GN AF LUO, JS MERCHANT, N ESCORCIAAPARICIO, EJ MARONI, VA TANI, BS CARTER, WL RILEY, GN TI COMPOSITION AND MICROSTRUCTURAL EVOLUTION OF NONSUPERCONDUCTING PHASES IN SILVER-CLAD (BI,PB)2SR2CA2CU3OX COMPOSITE CONDUCTORS SO JOURNAL OF MATERIALS RESEARCH LA English DT Article ID CA-CU-O; SUPERCONDUCTING CERAMICS; WIRES; TAPES; EQUILIBRIA; MECHANISM; DIAGRAM; GROWTH; FILMS AB The composition and microstructural evolution of nonsuperconducting phases during the course of formation of (Bi,Pb)2Sr2Ca2Cu3Ox (Bi-2223) in a silver sheath have been investigated by x-ray diffraction (XRD) analysis, scanning electron microscopy (SEM), energy dispersive x-ray spectroscopy (EDX), and digital image analysis. Wire samples fabricated by the oxide-powder-in-tube technique were heat-treated under a variety of conditions (time, temperature, and oxygen pressure). Backscattered images taken on polished but unetched transverse cross sections were subjected to computerized image processing, which allowed determination of the stoichiometry and quantification of microstructural characteristics (such as area fraction, size distribution, position, and orientation) of each nonsuperconducting particle. The dominant nonsuperconducting phases observed by SEM/EDX were CuO, (Ca, Sr)2CuO3 (2/1), and (Ca, Sr)14Cu24O41 (14/24) in amounts that varied depending on the annealing temperature, time, and oxygen partial pressure. Time evolution studies performed at 825-degrees-C in 0.075 atm O2 showed that the area fraction of 2/1 decreased with reaction time, while that for 14/24 increased. In all cases, a substantial amount (> 10% area fraction) of nonsuperconducting phases was detected even after all the Bi2Sr2CaCu2Oy (Bi-2212) in the as-rolled composite conductor was fully converted to Bi-2223, as determined by XRD. High aspect ratio nonsuperconducting particles were initially randomly oriented in the composite conductor core but gradually aligned parallel to the silver/(Bi,Pb)-Sr-Ca-Cu-O interface after extended annealing. They tended to segregate and exhibited a much broader size distribution when processing was carried out at temperatures and oxygen partial pressures on the high end of the normal processing range, most likely as a result of the occurrence of partial melting in the system. C1 AMER SUPERCOND CORP,WESTBOROUGH,MA 01581. RP LUO, JS (reprint author), ARGONNE NATL LAB,ARGONNE,IL 60439, USA. NR 28 TC 33 Z9 33 U1 0 U2 2 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 DEC PY 1994 VL 9 IS 12 BP 3059 EP 3067 DI 10.1557/JMR.1994.3059 PG 9 WC Materials Science, Multidisciplinary SC Materials Science GA PW305 UT WOS:A1994PW30500007 ER PT J AU HISHMEH, GA CARTZ, L DESAGE, F TEMPLIER, C DESOYER, JC BIRTCHER, RC AF HISHMEH, GA CARTZ, L DESAGE, F TEMPLIER, C DESOYER, JC BIRTCHER, RC TI RARE-GAS BUBBLES IN MUSCOVITE MICA IMPLANTED WITH XENON AND KRYPTON SO JOURNAL OF MATERIALS RESEARCH LA English DT Article AB Xenon and krypton have been implanted into muscovite mica at room temperature and at liquid nitrogen temperature. The behavior of the implanted Xe and Kr was followed by low-temperature transmission electron microscopy and energy dispersive x-ray analysis. An electron diffraction pattern of diffuse bands is observed at room temperature due to the presence of fluid rare gas and to noncrystalline mica. Visible cavities with diameters 10-300 nm formed in the Xe-implanted mica. Visible cavities in room-temperature Kr-implanted mica ranged from 5-50 nm in diameter. The gas pressures at room temperature in the cavities are estimated, assuming all of the implanted gas precipitated in cavities to be approximately 10 MPa for Xe and approximately 20 MPa for Kr. These pressures are considerably lower than found for rare gases implanted in metals and ceramics, but sufficient to liquefy the rare gases at room temperature. The Xe and Kr were observed by dark-field microscopy to form fcc crystalline solids within the cavities at temperatures below their triple points, with lattice parameters of a(Xe) = 0.630 +/- 0.0015 nm and a(Kr) = 0.565 +/- 0.005 nm. The solid Xe within bubbles was unstable under the electron beam of the transmission electron microscope at temperatures above 80 K, while the solid Kr within bubbles was unstable at temperatures as low as 35 K. The crystalline mica matrix undergoes a transformation from a crystalline structure to an amorphous structure as a result of implantation. C1 MARQUETTE UNIV,DEPT MAT SCI & ENGN,MILWAUKEE,WI 53233. UNIV POITIERS,MET PHYS LAB,F-86022 POITIERS,FRANCE. ARGONNE NATL LAB,DIV MAT SCI,ARGONNE,IL 60439. NR 30 TC 6 Z9 6 U1 0 U2 0 PU MATERIALS RESEARCH SOCIETY PI PITTSBURGH PA 9800 MC KNIGHT ROAD SUITE 327, PITTSBURGH, PA 15237 SN 0884-2914 J9 J MATER RES JI J. Mater. Res. PD DEC PY 1994 VL 9 IS 12 BP 3095 EP 3107 DI 10.1557/JMR.1994.3095 PG 13 WC Materials Science, Multidisciplinary SC Materials Science GA PW305 UT WOS:A1994PW30500011 ER PT J AU CHANG, HLM ZHANG, H SHEN, Z WANG, Q AF CHANG, HLM ZHANG, H SHEN, Z WANG, Q TI EPITAXIAL THIN-FILMS OF PBTIO3/SNO2 HETEROSTRUCTURES ON SAPPHIRE SO JOURNAL OF MATERIALS RESEARCH LA English DT Article ID MICROSTRUCTURE; MOCVD AB Epitaxial films of single-layer SnO2 and PbTiO3/SnO2 heterostructures were obtained on (0001) sapphire (alpha - Al2O3) substrates by metal-organic chemical vapor deposition. X-ray diffraction and transmission electron microscopy were used to characterize the structural properties of these films. The epitaxial relationship for the heterostructure PbTiO3/SnO2/sapphire was found to be (111) [011BAR]PbTiO3 parallel-to (100) [001]SnO2 parallel-to (0001) [11BAR00]alpha - Al2O3. The fact that epitaxial ferroelectric films were obtainable in such a structurally highly heterogeneous system suggests that a wide range of material selection is possible in exploring the kind of applications that need to utilize epitaxial ferroelectric films in a multilayered heterostructure. RP CHANG, HLM (reprint author), ARGONNE NATL LAB,DIV MAT SCI,ARGONNE,IL 60439, USA. NR 13 TC 5 Z9 5 U1 1 U2 2 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 DEC PY 1994 VL 9 IS 12 BP 3108 EP 3112 DI 10.1557/JMR.1994.3108 PG 5 WC Materials Science, Multidisciplinary SC Materials Science GA PW305 UT WOS:A1994PW30500012 ER PT J AU RANKIN, J SHELDON, BW BOATNER, LA AF RANKIN, J SHELDON, BW BOATNER, LA TI THE MEASUREMENT AND ANALYSIS OF EPITAXIAL RECRYSTALLIZATION KINETICS IN ION-BEAM-AMORPHIZED SRTIO3 SO JOURNAL OF MATERIALS RESEARCH LA English DT Article AB The solid-state epitaxial-regrowth kinetics of ion-beam-amorphized SrTiO3 surfaces annealed in water-vapor-rich atmospheres have been studied using time-resolved reflectivity (TRR). For this material, the conversion of the reflectivity-versus-time data obtained from the TRR measurements to recrystallized depth-versus-time data is more complicated than in systems such as silicon, where the reflectivity can be fit by assuming that the refractive index N (N = n + ik) in the amorphous layer is constant. In SrTiO3, agreement between measurements made directly with Rutherford backscattering spectroscopy (RBS) and those made using TRR can be obtained only when N is permitted to vary within the amorphous layer, with nonzero values for both the real and imaginary components. In some cases, the roughness of the amorphous/crystalline interface must also be considered. Additionally, a model for H2O-enhanced epitaxial regrowth is presented, which is in good agreement with the shape of the depth-versus-time profiles that are obtained from the TRR data. C1 OAK RIDGE NATL LAB,DIV SOLID STATE,OAK RIDGE,TN 37831. RP RANKIN, J (reprint author), BROWN UNIV,DIV ENGN,PROVIDENCE,RI 02912, USA. RI Boatner, Lynn/I-6428-2013 OI Boatner, Lynn/0000-0002-0235-7594 NR 12 TC 13 Z9 13 U1 0 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 DEC PY 1994 VL 9 IS 12 BP 3113 EP 3120 DI 10.1557/JMR.1994.3113 PG 8 WC Materials Science, Multidisciplinary SC Materials Science GA PW305 UT WOS:A1994PW30500013 ER PT J AU RAWERS, JC ASAI, G DUNNING, JS AF RAWERS, JC ASAI, G DUNNING, JS TI CHANGE IN MECHANICAL-PROPERTIES AND MICROSTRUCTURE OF 201 STAINLESS-STEEL WITH INCREASED NITROGEN ALLOYING SO JOURNAL OF MATERIALS RESEARCH LA English DT Article AB It is well known that mechanical properties of commercial stainless steel are improved by alloying with nitrogen. In this study a series of nitrogenated commercial 201 stainless steel alloys with nitrogen levels as high as 2.6 wt.% were obtained by melting in a hot-isostatic-pressure furnace using nitrogen as the pressurizing gas. Nitrogen concentrations in excess of 1.25 wt.% formed a series of different chromium nitride precipitates and morphologies depending upon the nitrogen concentration. Five different nitrogen levels were fabricated using the same processing conditions recommended for 201 stainless steel including hot-and cold-working, and heat-treating at two different temperatures. Tensile strength of the nitrogenated materials at each processing step was related to the interstitial nitrogen concentration and the presence or absence of precipitates. The presence of chromium precipitates did reduce the fracture ductility and changed the fracture features. This U.S. Bureau of Mines study shows that increasing the nitrogen concentration in commercial steels above their current level has positive effects on mechanical properties as long as the nitrogen solubility level is not exceeded and chromium nitride precipitates begin to form. RP RAWERS, JC (reprint author), US BUR MINES,ALBANY RES CTR,ALBANY,OR 97321, USA. NR 10 TC 3 Z9 3 U1 0 U2 0 PU MATERIALS RESEARCH SOCIETY PI PITTSBURGH PA 9800 MC KNIGHT ROAD SUITE 327, PITTSBURGH, PA 15237 SN 0884-2914 J9 J MATER RES JI J. Mater. Res. PD DEC PY 1994 VL 9 IS 12 BP 3160 EP 3169 DI 10.1557/JMR.1994.3160 PG 10 WC Materials Science, Multidisciplinary SC Materials Science GA PW305 UT WOS:A1994PW30500019 ER PT J AU HJELM, RP WAMPLER, WA SEEGER, PA GERSPACHER, M AF HJELM, RP WAMPLER, WA SEEGER, PA GERSPACHER, M TI THE MICROSTRUCTURE AND MORPHOLOGY OF CARBON-BLACK - A STUDY USING SMALL-ANGLE NEUTRON-SCATTERING AND CONTRAST VARIATION SO JOURNAL OF MATERIALS RESEARCH LA English DT Article ID X-RAY-SCATTERING AB This is a study of the form and structure of particles and particle aggregates of an experimental high surface area carbon black (HSA) using small-angle neutron scattering, and the method of contrast variation. Contrast variation was effected by studying suspensions of the carbon black in cyclohexane containing different fractions of deuterocyclohexane. We find that the approximately 28 nm diameter HSA particles are arranged as small, linear aggregates with an average aggregation number between 4 and 6. The structure averaged over the particle population is best represented by a prolate ellipsoid of revolution with semiaxes 14.5 and 76.4 nm. The surface of the aggregates appears smooth over length scales larger than 1 nm, which places an upper limit on the surface roughness observed by other methods. The internal structure of the aggregates is described by a shell-core model, with the shell density being consistent with a graphitic structure and the core being of lower density, more like amorphous carbon. Some fraction of the core volume (0.1 to 0.2) is taken up by voids that are not accessible to the solvent. An estimate of the shell thickness gives 1 to 2 nm along the ellipsoid minor axis and 6 to 10 nm along the major axis. The particles of the aggregate appear to be fused so that the less dense amorphous core is continuous through the inner parts of the aggregate. The information that can be obtained on the internal structure using contrast variation is limited by heterogeneity in the chemical composition of carbon black aggregates. C1 SID RICHARDSON CARBON CO,FT WORTH,TX 76106. RP HJELM, RP (reprint author), LOS ALAMOS NATL LAB,LOS ALAMOS NEUTRON SCATTERING CTR,LOS ALAMOS,NM 87545, USA. RI Lujan Center, LANL/G-4896-2012 NR 21 TC 39 Z9 40 U1 0 U2 8 PU MATERIALS RESEARCH SOCIETY PI PITTSBURGH PA 9800 MC KNIGHT ROAD SUITE 327, PITTSBURGH, PA 15237 SN 0884-2914 J9 J MATER RES JI J. Mater. Res. PD DEC PY 1994 VL 9 IS 12 BP 3210 EP 3222 DI 10.1557/JMR.1994.3210 PG 13 WC Materials Science, Multidisciplinary SC Materials Science GA PW305 UT WOS:A1994PW30500025 ER PT J AU LARACURZIO, E FERBER, MK AF LARACURZIO, E FERBER, MK TI METHODOLOGY FOR THE DETERMINATION OF THE INTERFACIAL PROPERTIES OF BRITTLE-MATRIX COMPOSITES SO JOURNAL OF MATERIALS SCIENCE LA English DT Article ID PUSH-OUT TEST; REINFORCED CERAMIC COMPOSITES; FIBER; STRESS; SHEAR AB The interfacial properties of a glass-ceramic matrix composite (SiC/CAS) were determined from single-fibre push-out tests using the interfacial test system. The coefficient of friction, mu, the residual clamping stress, sigma(c), and fibre axial residual stress, sigma(z), were extracted by fitting the experimental stress versus fibre-end displacement curves using the models of Hsueh, and Kerans and Parthasarathy. Using Hsueh's model, the intrinsic interfacial frictional stress (tau = mu sigma(c)) was found to be 11.1 +/- 3.2 MPa, whereas by using Kerans-Parthasarathy's model it was found to be 8.2 +/- 1.5 MPa. Comparisons between these models are included, together with a discussion of data analysis techniques. RP LARACURZIO, E (reprint author), OAK RIDGE NATL LAB,DIV MET & CERAM,POB 2008,OAK RIDGE,TN 37831, USA. NR 28 TC 23 Z9 23 U1 0 U2 6 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 DEC 1 PY 1994 VL 29 IS 23 BP 6152 EP 6158 DI 10.1007/BF00354555 PG 7 WC Materials Science, Multidisciplinary SC Materials Science GA PX086 UT WOS:A1994PX08600014 ER PT J AU THOM, AJ AKINC, M CAVIN, OB HUBBARD, CR AF THOM, AJ AKINC, M CAVIN, OB HUBBARD, CR TI THERMAL-EXPANSION ANISOTROPY OF TI5SI3 SO JOURNAL OF MATERIALS SCIENCE LETTERS LA English DT Article ID POLAR INTERMETALLIC COMPOUNDS; INTERSTITIAL CHEMISTRY; ZR5SB3; PHASES C1 IOWA STATE UNIV SCI & TECHNOL,DEPT MAT SCI & ENGN,AMES,IA 50011. OAK RIDGE NATL LAB,HIGH TEMP MAT LAB,OAK RIDGE,TN 37831. RP THOM, AJ (reprint author), IOWA STATE UNIV SCI & TECHNOL,AMES LAB,AMES,IA 50011, USA. NR 16 TC 22 Z9 22 U1 0 U2 2 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 DEC 1 PY 1994 VL 13 IS 23 BP 1657 EP 1660 DI 10.1007/BF00451730 PG 4 WC Materials Science, Multidisciplinary SC Materials Science GA PX084 UT WOS:A1994PX08400001 ER PT J AU STADLER, PF SCHUSTER, P PERELSON, AS AF STADLER, PF SCHUSTER, P PERELSON, AS TI IMMUNE NETWORKS MODELED BY REPLICATOR EQUATIONS SO JOURNAL OF MATHEMATICAL BIOLOGY LA English DT Article DE B-CELLS; IMMUNE SYSTEM; IDIOTYPIC NETWORKS; MUTATION; REPLICATOR EQUATIONS ID AUTOCATALYTIC REACTION NETWORKS; NATURAL SELF-ORGANIZATION; DIFFERENTIAL-EQUATIONS; IDIOTYPIC NETWORKS; STATIONARY STATES; HYPERCYCLE; PRINCIPLE; DYNAMICS; SYSTEMS; OSCILLATIONS AB In order to evaluate the role of idiotypic networks in the operation of the immune system a number of mathematical models have been formulated. Here we examine a class of B-cell models in which cell proliferation is governed by a non-negative, unimodal, symmetric response function f(h), where the field h summarizes the effect of the network on a single clone. We show that by transforming into relative concentrations, the B-cell network equations can be brought into a form that closely resembles the replicator equation. We then show that when the total number of clones in a network is conserved, the dynamics of the network can be represented by the dynamics of a replicator equation. The number of equilibria and their stability are then characterized using methods developed for the study of second-order replicator equations. Analogies with standard Lotka-Volterra equations are also indicated. A particularly interesting result of our analysis is the fact that even though the immune network equations are not second-order, the number and stability of their equilibria can be obtained by a superposition of second-order replicator systems. As a consequence, the problem of finding all of the equilibrium points of the nonlinear network equations can be reduced to solving linear equations. C1 UNIV VIENNA,INST THEORET CHEM,VIENNA,AUSTRIA. INST MOLEK BIOTECHNOL EV,O-6900 JENA,GERMANY. LOS ALAMOS NATL LAB,DIV THEORET,LOS ALAMOS,NM 87545. RP STADLER, PF (reprint author), SANTA FE INST,1660 OLD PECOS TRAIL,SANTA FE,NM 87501, USA. RI Stadler, Peter F./L-7857-2015 OI Stadler, Peter F./0000-0002-5016-5191 FU NCRR NIH HHS [RR06555] NR 48 TC 10 Z9 10 U1 1 U2 3 PU SPRINGER VERLAG PI NEW YORK PA 175 FIFTH AVE, NEW YORK, NY 10010 SN 0303-6812 J9 J MATH BIOL JI J. Mathemat. Biol. PD DEC PY 1994 VL 33 IS 2 BP 111 EP 137 DI 10.1007/BF00160176 PG 27 WC Biology; Mathematical & Computational Biology SC Life Sciences & Biomedicine - Other Topics; Mathematical & Computational Biology GA PZ739 UT WOS:A1994PZ73900001 PM 7868989 ER PT J AU LLOYD, S AF LLOYD, S TI NECESSARY AND SUFFICIENT CONDITIONS FOR QUANTUM COMPUTATION SO JOURNAL OF MODERN OPTICS LA English DT Article ID CELLULAR AUTOMATA; DYNAMIC-SYSTEMS; TURING-MACHINES; COMPUTERS; UNDECIDABILITY; PHYSICS; UNPREDICTABILITY; REVERSIBILITY; DISSIPATION; PRINCIPLE AB Necessary and sufficient conditions are given for a quantum-mechanical system to possess a coordinate system with respect to which its behaviour at discrete times is that of a universal digital computer. The form of the diagonal representation for the unitary time evolution operator for quantum universal computers is derived; aspects of the transformation between the diagonal representation and the computational representation are shown to be uncomputable. A quantum-mechanical treatment of macroscopic, dissipative computers is given. C1 LOS ALAMOS NATL LAB,CTR NONLINEAR STUDIES,LOS ALAMOS,NM 87545. RP LLOYD, S (reprint author), LOS ALAMOS NATL LAB,COMPLEX SYST GRP T13,POB 1663,LOS ALAMOS,NM 87545, USA. NR 47 TC 10 Z9 10 U1 0 U2 0 PU TAYLOR & FRANCIS LTD LONDON PI LONDON PA ONE GUNDPOWDER SQUARE, LONDON, ENGLAND EC4A 3DE SN 0950-0340 J9 J MOD OPTIC JI J. Mod. Opt. PD DEC PY 1994 VL 41 IS 12 BP 2503 EP 2520 DI 10.1080/09500349414552341 PG 18 WC Optics SC Optics GA QD473 UT WOS:A1994QD47300025 ER PT J AU CHERNIKOV, VN GORODETSKY, AE KANASHENKO, SL ZAKHAROV, AP WAMPLER, WR DOYLE, BL AF CHERNIKOV, VN GORODETSKY, AE KANASHENKO, SL ZAKHAROV, AP WAMPLER, WR DOYLE, BL TI TRAPPING OF DEUTERIUM IN BORON AND TITANIUM-MODIFIED GRAPHITES BEFORE AND AFTER CARBON ION IRRADIATION SO JOURNAL OF NUCLEAR MATERIALS LA English DT Article ID TRITIUM; RETENTION; REACTOR AB Nuclear reaction analysis was used to investigate the retention of deuterium (D) at radiation damage in new graphites USB-15, PGI, RG-Ti-91, RG-Ti-91 with 0.5 wt%B made in Russia and in POCO AXF-5Q graphite. Samples were irradiated with C+ ions to produce damage up to doses of approximately 10 displacements per atom (dpa), and then soaked in deuterium gas at 1473 K. The concentration of D in the damaged region increased with damage and saturated for damage levels above about 1 dpa. At saturation the smallest D concentration was found in USB-15 (approximately 60 appm), and the largest D concentration was found in RG-Ti-91 (approximately 1500 appm). Based on microstructural investigations done by TEM, an attempt was made to relate differences in concentrations of retained D to variations in radiation-induced trap concentration and to kinetic limitations for D atom access to traps available. The effect of boron on D trapping in graphite was also examined. C1 SANDIA NATL LABS, ALBUQUERQUE, NM 87185 USA. RP RUSSIAN ACAD SCI, INST PHYS CHEM, LENINSKY PR 31, MOSCOW 117915, RUSSIA. NR 17 TC 15 Z9 15 U1 0 U2 1 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 DEC PY 1994 VL 217 IS 3 BP 250 EP 257 DI 10.1016/0022-3115(94)90374-3 PG 8 WC Materials Science, Multidisciplinary; Nuclear Science & Technology SC Materials Science; Nuclear Science & Technology GA PX036 UT WOS:A1994PX03600005 ER PT J AU REMEC, I WANG, JA KAM, FBK FARRELL, K AF REMEC, I WANG, JA KAM, FBK FARRELL, K TI EFFECTS OF GAMMA-INDUCED DISPLACEMENTS ON HFIR PRESSURE-VESSEL MATERIALS SO JOURNAL OF NUCLEAR MATERIALS LA English DT Article ID EMBRITTLEMENT; SPECTRUM AB Accelerated radiation-induced embrittlement of the High Flux Isotope Reactor (HFIR) surveillance materials has been investigated since its discovery in 1986. Recent comprehensive dosimetry experiments revealed the presence of an intense gamma field at the HFIR surveillance locations near the pressure vessel. Gamma-induced reactions were found to dominate the response of several dosimeters and were crucial for the explanation of dosimetry results. This finding precipitated an assessment of the gamma-induced displacements-per-atom (dpa) rate, which was found to exceed the neutron-induced dpa rate at all locations analyzed. When the sum of neutron and gamma dpa is used for the interpretation of the HFIR surveillance results, the HFIR data are consistent with data from the Oak Ridge Research Reactor (ORR) and other test reactors. The accelerated embrittlement is therefore explained in terms of hitherto uncounted dpa induced by gamma rays. RP REMEC, I (reprint author), OAK RIDGE NATL LAB,DIV COMP APPLICAT,POB 2008,OAK RIDGE,TN 37831, USA. OI Wang, Jy-An/0000-0003-2402-3832 NR 29 TC 25 Z9 25 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 DEC PY 1994 VL 217 IS 3 BP 258 EP 268 DI 10.1016/0022-3115(94)90375-1 PG 11 WC Materials Science, Multidisciplinary; Nuclear Science & Technology SC Materials Science; Nuclear Science & Technology GA PX036 UT WOS:A1994PX03600006 ER PT J AU MASON, RE ELGENK, MNS AF MASON, RE ELGENK, MNS TI EXPERIMENTAL INVESTIGATION OF THE RUTHENIUM URANIUM AND RHENIUM URANIUM BINARY-SYSTEMS SO JOURNAL OF NUCLEAR MATERIALS LA English DT Article ID NITRIDE; RE; TA AB The solidus and liquidus temperatures of the ruthenium-uranium binary system between 50 and 100 at% ruthenium were identified. The alloy were heated in a nested crucible arrangement, with the test alloy being held in an inner tungsten-lined graphite crucible or a ceramic crucible. An eutectic isotherm of 1861 +/- 20 K for URu3 + Ru with a URu3 melting temperature of 1938 +/- 22 K was measured. The URu3 + Ru eutectic composition was 77.5 +/- 1 at% ruthenium. A U3Ru4 + U3Ru5 peritectic temperature of 1439 +/- 16 K and a U3Ru5 + URu3 peritectic temperature of 1460 +/- 20 K were measured. The solubility of ruthenium, in URu3 was approximately 0.5 +/- 1 at% ruthenium, and the solubility of uranium in ruthenium was less than 0.5 +/- 1 at% ruthenium. The URe2 + Re isotherm was also verified to be 2415 +/- 20 K. C1 UNIV NEW MEXICO,INST SPACE NUCL POWER STUDIES,ALBUQUERQUE,NM 87131. RP MASON, RE (reprint author), LOS ALAMOS NATL LAB,DIV NUCL MAT TECHNOL,LOS ALAMOS,NM 87545, USA. NR 31 TC 8 Z9 8 U1 1 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 DEC PY 1994 VL 217 IS 3 BP 304 EP 321 DI 10.1016/0022-3115(94)90381-6 PG 18 WC Materials Science, Multidisciplinary; Nuclear Science & Technology SC Materials Science; Nuclear Science & Technology GA PX036 UT WOS:A1994PX03600012 ER PT J AU NAPOLITANO, GE AF NAPOLITANO, GE TI THE RELATIONSHIP OF LIPIDS WITH LIGHT AND CHLOROPHYLL MEASUREMENTS IN FRESH-WATER ALGAE AND PERIPHYTON SO JOURNAL OF PHYCOLOGY LA English DT Article DE CHLOROPHYLL; CHLOROPHYTA; CLADOPHORA; FATTY ACIDS; LIPIDS; PERIPHYTON; SPIROGYRA; STEROLS ID FATTY-ACID COMPOSITION; COMMUNITY STRUCTURE; MICROBIAL BIOMASS; IRRADIANCE; PHYTOPLANKTON; MICROALGAE; ERGOSTEROL; EXTRACTION; INTENSITY; MEMBRANES AB Lipid content and lipid class composition were determined in stream periphyton and the filamentous green algae Cladophora sp. and Spirogyra sp. Sterols and phospholipids were compared to chlorophyll a (chi a) as predictors of biomass for stream periphyton and algae. Chlorophyll a, phospholipids, and sterols were each highly correlated with ash-free dry mass (AFDM) (r(2) > 0.98). Stream periphyton exposed naturally to high light (HL) and low light (LL) had chi a concentrations (mu g chl a. mg(-1) AFDM) of 7.9 +/- 0.7 and 12.4 +/- 2.9, respectively, while the sterol concentrations of these HL and LL stream periphyton (1.6 +/- 0.4) were not significantly different (P > 0.05). Periphyton exposed to an irradiance of 300 mu mol photons.m(-2).s(-1) in the laboratory for 60 h had 5.6 +/- 0.55 mu g chl a.mg(-1) AFDM, but the same periphyton exposed to 2% incident light for the same amount of time had 11.0 +/- 0.56 mu g chl a.mg(-1) AFDM. Sterol concentrations in these periphyton communities remained unchanged (1.5 +/- 0.3 mu g.mg(-1) AFDM). Similar results (i.e. changes in chi a but stability of sterol concentrations in response to irradiance changes) were also found for Cladophora and Spirogyra in laboratory experiments. Sterols can be quantified rapidly from a few milligrams of algae and appear to be a useful predictor of eukaryote biomass, whereas cellular levels of chl a vary substantially with light conditions. Phospholipids (or phospholipid fatty acids) are considered to be a reliable measure of viable microbial biomass. Nevertheless, phospholipid content varied substantially and unpredictably among algae and periphyton under different light regimes. Irradiance also had a significant effect on storage lipids: HL Cladophora and HL periphyton had 2 x and 5 x greater concentrations of triacylglycerols, respectively, compared to their LL forms. HL and LL algae also differed in the concentration of several major fatty acids. These light-induced changes in algal lipids and fatty acids have important implications for grazers. RP NAPOLITANO, GE (reprint author), OAK RIDGE NATL LAB,DIV ENVIRONM SCI,POB 2008,OAK RIDGE,TN 37831, USA. NR 50 TC 58 Z9 61 U1 8 U2 26 PU PHYCOLOGICAL SOC AMER INC PI LAWRENCE PA 810 EAST 10TH ST, LAWRENCE, KS 66044 SN 0022-3646 J9 J PHYCOL JI J. Phycol. PD DEC PY 1994 VL 30 IS 6 BP 943 EP 950 DI 10.1111/j.0022-3646.1994.00943.x PG 8 WC Plant Sciences; Marine & Freshwater Biology SC Plant Sciences; Marine & Freshwater Biology GA QD954 UT WOS:A1994QD95400005 ER PT J AU ZHU, W HUANG, YH PARKER, GA KOURI, DJ HOFFMAN, DK AF ZHU, W HUANG, YH PARKER, GA KOURI, DJ HOFFMAN, DK TI APPLICATION OF DISTRIBUTED APPROXIMATING FUNCTIONALS FOR ATOM RIGID ROTOR INELASTIC-SCATTERING - BODY FRAME CLOSE-COUPLING TIME-DEPENDENT AND TIME-INDEPENDENT WAVEPACKET APPROACHES SO JOURNAL OF PHYSICAL CHEMISTRY LA English DT Article ID LIPPMANN-SCHWINGER EQUATIONS; TO-ENERGY TRANSFORM; SCHRODINGER; PROPAGATION; COLLISIONS; DYNAMICS AB We provide the first example of the application of distributed approximating functionals (DAFs) for 3D molecular scattering using non-Cartesian coordinates (atom-rigid rotor inelastic scattering), in both time-dependent and time-independent wavepacket schemes. With the aid of the body frame close-coupling wavepacket technique, the 3D problem is expressed as a set of coupled 1D problems. Since the discretized DAF representations for the kinetic energy operator and the free particle time evolution operator are highly banded Toeplitz matrices, the action of these operators in the wavepacket formalism can tie evaluated either by simple matrix-vector multiplication or by a fast-DAF convolution method. Excellent agreement is obtained with results of earlier calculations by Sun, Judson, and Kouri (J. Chem. Phys. 1989, 90, 241). C1 UNIV HOUSTON,DEPT CHEM,HOUSTON,TX 77204. UNIV HOUSTON,DEPT PHYS,HOUSTON,TX 77204. IOWA STATE UNIV SCI & TECHNOL,DEPT CHEM,AMES,IA 50011. IOWA STATE UNIV SCI & TECHNOL,AMES LAB,AMES,IA 50011. RI Parker, Gregory/A-4327-2009 OI Parker, Gregory/0000-0002-0225-8887 NR 22 TC 7 Z9 7 U1 0 U2 0 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 SN 0022-3654 J9 J PHYS CHEM-US JI J. Phys. Chem. PD DEC 1 PY 1994 VL 98 IS 48 BP 12516 EP 12520 DI 10.1021/j100099a012 PG 5 WC Chemistry, Physical SC Chemistry GA PV321 UT WOS:A1994PV32100012 ER PT J AU DESHMUKH, S MYERS, JD XANTHEAS, SS HESS, WP AF DESHMUKH, S MYERS, JD XANTHEAS, SS HESS, WP TI INVESTIGATION OF ACETYL-CHLORIDE PHOTODISSOCIATION BY PHOTOFRAGMENT IMAGING SO JOURNAL OF PHYSICAL CHEMISTRY LA English DT Article ID ENHANCED MULTIPHOTON IONIZATION; TRANSLATIONAL ENERGY; ALPHA-BOND; BASIS-SETS; STATE; SPECTROSCOPY; EXCITATION; ACETONE; ATOMS; DISTRIBUTIONS AB The photofragment ion imaging technique is used to measure the velocity distributions of atomic chlorine, methyl. and carbon monoxide fragments generated in the photodissociation of acetyl chloride at 236 nm. The fragments are selectively ionized by (2 + 1) multiphoton ionization and projected onto a two-dimensional position-sensitive detector to obtain speed and angular distributions. The Cl images display anisotropic angular distributions, characteristic of a prompt, impulsive dissociation of the C-Cl bond. A fraction of the CH3CO, produced as a primary photoproduct, subsequently decomposes to form CH3 and CO. The CH3 and CO images are isotropic, suggesting that rotation of the acetyl radical intermediate occurs prior to the secondary dissociation. The internal state distribution of CO is probed using (2 + 1) multiphoton ionization via the B-1 Sigma(+) state near 230 nm. The rotational state distribution of CO extends to S' = 30, while no vibrational excitation is observed. The transition state structure of the CH3CO intermediate, leading to dissociation into CH3 and CO, is computed via ab initio quantum mechanical methods. The barrier for CH3CO dissociation is theoretically predicted at 19.1 kcal/mol at the MP2/cc-pVTZ level of theory. The theoretically predicted dissociation mechanism and barrier agree well with the measured internal state distributions and velocities of the CH3 and CO secondary fragments. C1 PACIFIC NW LAB, ENVIRONM MOLEC SCI LAB, RICHLAND, WA 99352 USA. RI Xantheas, Sotiris/L-1239-2015; OI Myers, James/0000-0001-8462-650X; Xantheas, Sotiris/0000-0002-6303-1037 NR 42 TC 68 Z9 68 U1 0 U2 1 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 SN 0022-3654 J9 J PHYS CHEM-US JI J. Phys. Chem. PD DEC 1 PY 1994 VL 98 IS 48 BP 12535 EP 12544 DI 10.1021/j100099a016 PG 10 WC Chemistry, Physical SC Chemistry GA PV321 UT WOS:A1994PV32100016 ER PT J AU MEZYK, SP MACFARLANE, R BARTELS, DM AF MEZYK, SP MACFARLANE, R BARTELS, DM TI EPR MEASUREMENT OF THE REACTION OF ATOMIC-HYDROGEN WITH PERIODATE AND IODATE IN AQUEOUS-SOLUTION SO JOURNAL OF PHYSICAL CHEMISTRY LA English DT Article ID HYDRATED ELECTRONS; WATER RADIOLYSIS AB Electron paramagnetic resonance free induction decay (FID) attenuation measurements have been used to determine Arrhenius parameters for the reaction of hydrogen atoms with IO4- and IO3- in aqueous solution at pH 4.6. At 25 degrees C, scavenging rate constants of(7.31 +/- 0.12) x 10(8) and (1.22 +/- 0.04) x 10(7) dm(3) mol(-1) s(-1) were obtained for IO4- and IO3-, respectively, with corresponding activation energies, measured over the temperature range 6-75 degrees C, of 22.35 and 27.46 kJ mol(-1). From kinetic measurements in 0.10 and 1.00 M HClO4 over the same temperature range, the rate constants for hydrogen atom reaction u with the acid forms of these species, H(5)IO6 and HIO3, were calculated to be 3.5 x 10(8) and 6.0 x 10(6) dm(3) mol(-1) s(-1) (25 degrees C), with activation energies of 53.00 and 36.55 kJ mol(-1), respectively. We suggest that all of these reactions involve oxygen atom transfer to the hydrogen atom, giving .OH and a reduced iodine complex as product. C1 ARGONNE NATL LAB,DIV CHEM,ARGONNE,IL 60439. RP MEZYK, SP (reprint author), ATOM ENERGY CANADA LTD,WHITESHELL LABS,PINAWA R0E 1L0,MB,CANADA. NR 32 TC 9 Z9 9 U1 0 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 DEC 1 PY 1994 VL 98 IS 48 BP 12594 EP 12599 DI 10.1021/j100099a023 PG 6 WC Chemistry, Physical SC Chemistry GA PV321 UT WOS:A1994PV32100023 ER PT J AU FOO, C KWEI, TK OKAMOTO, Y MCBREEN, J LEE, HS AF FOO, C KWEI, TK OKAMOTO, Y MCBREEN, J LEE, HS TI ALKALI-METAL ION CONDUCTORS BASED ON SULFONATED POLY(P-PHENYLENE TEREPHTHALAMIDE) SO JOURNAL OF POLYMER SCIENCE PART A-POLYMER CHEMISTRY LA English DT Article DE NA; LI POLY(PHENYLENE TEREPHTHALAMIDE SULFONATE SALTS) ION CONDUCTIVITY; MODIFIED ETHYLENE CARBONATE; BLEND SYSTEM ID SOLID POLYMER ELECTROLYTES AB To obtain thermally stable and mechanically strong sodium and lithium conducting polymers, we prepared Na+ and Li+ poly(phenylene terephthalamide sulfonate salts) (MW similar to 5500). We also synthesized oligo(ethylene oxide) (3, 5, or 7 units of ethylene oxide) substituted ethylene carbonate and poly[oxymethylene-oligo(oxyethylene)]. These are high boiling point liquids with high dielectric constants as well as metal chelating properties. Polyelectrolyte systems were prepared by mixing Na+ or Li+ poly(phenylene terephthalamide sulfonate) salts with various amounts of modified ethylene carbonate and/or poly[oxymethylene-oligo(oxyethylene)]. Films (0.1-0.5 mm thick) obtained from the blends were found to have considerable mechanical strength; forming free standing films. The ionic conductivities of the Na+ and Li+ polyelectrolyte systems were 10(-6)-10(-5) S/cm at 25 degrees C. Thermal properties of these blend systems were investigated in detail. (C) 1994 John Wiley and Sons, Inc. C1 POLYTECH INST NEW YORK,POLYMER RES INST,BROOKLYN,NY 11201. POLYTECH INST NEW YORK,DEPT CHEM,BROOKLYN,NY 11201. BROOKHAVEN NATL LAB,DEPT APPL SCI,UPTON,NY 11973. NR 24 TC 4 Z9 4 U1 1 U2 8 PU JOHN WILEY & SONS INC PI NEW YORK PA 605 THIRD AVE, NEW YORK, NY 10158-0012 SN 0887-624X J9 J POLYM SCI POL CHEM JI J. Polym. Sci. Pol. Chem. PD DEC PY 1994 VL 32 IS 16 BP 3009 EP 3017 DI 10.1002/pola.1994.080321602 PG 9 WC Polymer Science SC Polymer Science GA PU612 UT WOS:A1994PU61200002 ER PT J AU CHU, B WU, GW SCHNEIDER, DK AF CHU, B WU, GW SCHNEIDER, DK TI A SCATTERING STUDY ON INTERMICELLAR INTERACTIONS AND STRUCTURES OF POLYMERIC MICELLES SO JOURNAL OF POLYMER SCIENCE PART B-POLYMER PHYSICS LA English DT Article DE SCATTERING BEHAVIOR; INTERMICELLAR INTERACTIONS; POLYMERIC MICELLES ID ANGLE NEUTRON-SCATTERING; BLOCK-COPOLY(OXYETHYLENE OXYBUTYLENE OXYETHYLENE); OXIDE) TRIBLOCK COPOLYMER; AQUEOUS-SOLUTION; LIGHT-SCATTERING; O-XYLENE; MICROEMULSIONS; MICELLIZATION; GELATION AB The micellar structure is usually considered to be composed of a hard sphere (liquid) core and a heavily solvated corona. Therefore, the correction for intermicellar interactions at finite concentrations can be relatively complicated. In this article, small-angle neutron scattering of a copolymer, known as Pluronic L64 (PEO(13)PPO(30)PEO(13)), in o-xylene in the presence of D2O is used to demonstrate that, based on the hard sphere approximation, intermicellar interactions can be corrected by representing the micellar size as having an equivalent hard sphere radius. The procedure remains valid even if the micellar shape becomes asymmetric, with axial ratios of 3 similar to 4. For the present system, the equivalent hard sphere radius corresponds to the micellar core radius plus one-half of the micellar shell thickness. With the equivalent hard sphere approach, the scattering behavior of the micelle could be described by using a core-shell structure. (C) 1994 John Wiley and Sons, Inc. C1 SUNY STONY BROOK,DEPT MAT SCI & ENGN,STONY BROOK,NY 11794. BROOKHAVEN NATL LAB,DEPT BIOL,UPTON,NY 11973. RP CHU, B (reprint author), SUNY STONY BROOK,DEPT CHEM,STONY BROOK,NY 11794, USA. NR 32 TC 20 Z9 20 U1 2 U2 2 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 DEC PY 1994 VL 32 IS 16 BP 2605 EP 2614 DI 10.1002/polb.1994.090321606 PG 10 WC Polymer Science SC Polymer Science GA PU610 UT WOS:A1994PU61000006 ER PT J AU WANG, QG ANNIS, B WUNDERLICH, B AF WANG, QG ANNIS, B WUNDERLICH, B TI SURFACE STUDIES OF TETRAALKYLAMMONIUM BROMIDES AND IODIDES USING ATOMIC-FORCE MICROSCOPY SO JOURNAL OF POLYMER SCIENCE PART B-POLYMER PHYSICS LA English DT Article DE TETRAALKYLAMMONIUM HALIDE; ATOMIC FORCE MICROSCOPY; CRYSTAL STRUCTURE; SURFACE STRUCTURE; HEXTRIACONTANE ID STATE C-13 NMR; X = BR; ALKYLAMMONIUM SALTS; CONDIS CRYSTALS; SMALL MOLECULES; MESOPHASES; DISORDER; HOMOLOGS; MOTION; POLYETHYLENE AB The surface structures of two series of tetra-n-alkylammonium halides, N(CxH2x+1)(4)I and N(CxH2x+1)(4)Br have been investigated with atomic force microscopy (AFM) and compared to hexatriacontane (C36H74) The surfaces could be imaged with atomic resolution. The observed primitive, square surface-patterns of tetra-n-butyl chloride and bromide are in good accord with x-ray single-crystal structure. For n > 4, x-ray powder diffraction showed that increasing the alkyl chain-length leads mainly to an appropriate increase of the unit cell along the c-axis, which suggests similar layer structures for all long-chain salts beyond the butyl homologue. Within the centers of the molecular layers of these crystals reside the halide anions and the quaternary nitrogens. The surfaces accessible for AFM consist of methyl end-groups. As the number of carbon atoms increases beyond four, the surface symmetry changes to the face-centered square patterns characteristic of many paraffins. The chains of the tetraalkyl ammonium salts pack, however, less dense than paraffins. (C) 1994 John Wiley and Sons, Inc. C1 OAK RIDGE NATL LAB,DIV CHEM & ANALYT SCI,OAK RIDGE,TN 37831. RP WANG, QG (reprint author), UNIV TENNESSEE,DEPT CHEM,KNOXVILLE,TN 37996, USA. NR 20 TC 4 Z9 4 U1 0 U2 6 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 DEC PY 1994 VL 32 IS 16 BP 2653 EP 2659 DI 10.1002/polb.1994.090321611 PG 7 WC Polymer Science SC Polymer Science GA PU610 UT WOS:A1994PU61000011 ER PT J AU CHEN, W FU, YG WUNDERLICH, B CHENG, JL AF CHEN, W FU, YG WUNDERLICH, B CHENG, JL TI THE MORPHOLOGY OF GEL-SPUN POLYETHYLENE FIBERS, INVESTIGATED BY SOLID-STATE C-13 NMR SO JOURNAL OF POLYMER SCIENCE PART B-POLYMER PHYSICS LA English DT Article DE POLYETHYLENE; CRYSTAL; ORIENTED AMORPHOUS PHASE; INTERMEDIATE PHASE; AMORPHOUS PHASE; CONFORMATION; MOTION; DISORDER; C-13 NMR ID NUCLEAR MAGNETIC-RESONANCE; POLY(ETHYLENE-TEREPHTHALATE) FIBERS AB Gel-spun polyethylene fibers were analyzed at room temperature with C-13 NMR, using both, CP-MAS and BILEV (Bloch-decay with two-level decoupling). The analysis shows the existence of three different components in the fiber sample-a crystal component, an amorphous component and a third component, named the oriented, mobile component. This latter component has a C-13 chemical shift that is similar to the crystalline chemical shift, but with a mobility, expressed by T-1, that is closer to the amorphous component. The chemical shift and T-1 are as follows: 34.06 ppm and 28.1 s for the crystalline part; 31.70 ppm and 0.3 s for the amorphous part; and 34.06 ppm and 1.8 a for the oriented mobile component. The percentages are 63.2% crystalline; 34.0% oriented mobile, and 2.8% amorphous component. Using proton spin-diffusion measurements, it was possible to estimate the domain size of the crystalline and oriented mobile components to be 62.8 and 13.2 nm, respectively, in agreement with the results of a full-pattern x-ray study on the same sample. After melting of the fiber at 450 K and recrystallization on cooling, the oriented, mobile component is dramatically reduced. (C) 1994 John Wiley and Sons, Inc. C1 UNIV TENNESSEE,DEPT CHEM,KNOXVILLE,TN 37996. OAK RIDGE NATL LAB,DIV CHEM & ANALYT SCI,OAK RIDGE,TN 37831. RAYCHEM CORP,MENLO PK,CA 94025. NR 16 TC 35 Z9 35 U1 0 U2 6 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 DEC PY 1994 VL 32 IS 16 BP 2661 EP 2666 DI 10.1002/polb.1994.090321612 PG 6 WC Polymer Science SC Polymer Science GA PU610 UT WOS:A1994PU61000012 ER PT J AU CHENG, JL FONE, M REDDY, VN SCHWARTZ, KB FISHER, HP WUNDERLICH, B AF CHENG, JL FONE, M REDDY, VN SCHWARTZ, KB FISHER, HP WUNDERLICH, B TI IDENTIFICATION AND QUANTITATIVE-ANALYSIS OF THE INTERMEDIATE PHASE IN A LINEAR HIGH-DENSITY POLYETHYLENE SO JOURNAL OF POLYMER SCIENCE PART B-POLYMER PHYSICS LA English DT Article DE POLYETHYLENE; CRYSTALLINE; INTERMEDIATE PHASE; AMORPHOUS; CONFORMATION; MOTION; DISORDER; C-13 NMR; DSC; WAXD ID C-13 NMR; POLY(ETHYLENE-TEREPHTHALATE) FIBERS; MORPHOLOGY; DYNAMICS; CRYSTALS; T1 AB The observation of chain conformation and mobility in polyethylene by solid-state C-13 magic angle spinning (MAS) nuclear magnetic resonance (NMR) permits unambiguous identification and quantitative analysis of an intermediate phase. The carbon-carbon bonds in the intermediate phase adopt, on the average, an all-trans conformation and are more mobile than in the crystalline state (room temperature rate of reorientation approximate to 10(7) Hz). Comparisons of crystallinities by differential scanning calorimetry, wide-angle x-ray diffraction, and NMR support the high orientation of the intermediate phase and suggest a lower heat of fusion than for the crystals. Results from C-13 spin-lattice relaxation and H-1 spin diffusion show that the mass fractions are approximate to 20% and the domain sizes approximate to 36 Angstrom. Both change with crystallization and annealing conditions. (C) 1994 John Wiley and Sons, Inc. C1 UNIV AKRON,INST POLYMER SCI,AKRON,OH 44313. UNIV TENNESSEE,DEPT CHEM,KNOXVILLE,TN 37996. OAK RIDGE NATL LAB,DIV CHEM & ANALYT SCI,OAK RIDGE,TN 37831. RP CHENG, JL (reprint author), RAYCHEM CORP,300 CONSTITUT DR,MENLO PK,CA 94025, USA. NR 33 TC 68 Z9 68 U1 2 U2 12 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 DEC PY 1994 VL 32 IS 16 BP 2683 EP 2693 DI 10.1002/polb.1994.090321614 PG 11 WC Polymer Science SC Polymer Science GA PU610 UT WOS:A1994PU61000014 ER PT J AU DOYLE, M NEWMAN, J REIMERS, J AF DOYLE, M NEWMAN, J REIMERS, J TI A QUICK METHOD OF MEASURING THE CAPACITY VERSUS DISCHARGE RATE FOR A DUAL LITHIUM-ION INSERTION CELL UNDERGOING CYCLING SO JOURNAL OF POWER SOURCES LA English DT Article DE CAPACITY; DISCHARGE RATE; LITHIUM-ION INSERTION CELL; CYCLING AB During extended cycling of an experimental cell, it is common to test periodically the rate behaviour of the cell by performing a series of discharges at various rates and measuring the capacity to a cutoff potential. The fastest way to obtain this information is to carry out successive discharges at decreasing rates with a brief relaxation period between each discharge but no charging step. The capacity obtained at a given rate is assumed to be the cumulative capacity up to that point. We have simulated this testing procedure to determine when the method is valid and have developed criteria for the optimum number of discharges and relaxation times to use. It is found that a series of seven discharges with a 5 min relaxation period gives an accurate prediction of the cell capacity with less than 1% error. The mechanisms which cause erroneous results to arise are described. The system chosen for simulation is the LixC6/propylene carbonate +1 M LiClO4/LiyMn2O4 dual lithium-ion insertion cell. Experimental discharge curves are provided that verify the results of the simulations. C1 UNIV CALIF BERKELEY,DEPT CHEM ENGN,BERKELEY,CA 94720. MOLI ENERGY 1990 LTD,MAPLE RIDGE,BC V2X 9E7,CANADA. RP DOYLE, M (reprint author), UNIV CALIF BERKELEY,LAWRENCE BERKELEY LAB,DIV ENERGY & ENVIRONM,BERKELEY,CA 94720, USA. RI Newman, John/B-8650-2008; Reimers, Jan/K-1947-2014 OI Newman, John/0000-0002-9267-4525; Reimers, Jan/0000-0002-0844-5384 NR 11 TC 58 Z9 58 U1 2 U2 27 PU ELSEVIER SCIENCE SA LAUSANNE PI LAUSANNE 1 PA PO BOX 564, 1001 LAUSANNE 1, SWITZERLAND SN 0378-7753 J9 J POWER SOURCES JI J. Power Sources PD DEC PY 1994 VL 52 IS 2 BP 211 EP 216 DI 10.1016/0378-7753(94)02012-4 PG 6 WC Chemistry, Physical; Electrochemistry; Energy & Fuels; Materials Science, Multidisciplinary SC Chemistry; Electrochemistry; Energy & Fuels; Materials Science GA QD431 UT WOS:A1994QD43100008 ER PT J AU NILSEN, J VAINSHTEIN, LA IVANOV, IA SAFRONOVA, UI DUBAU, J CORNILLE, M AF NILSEN, J VAINSHTEIN, LA IVANOV, IA SAFRONOVA, UI DUBAU, J CORNILLE, M TI COMPARISON OF AUTOIONIZATION RATES FOR 3L3L'-STATES OF 2 ELECTRON-SYSTEMS SO JOURNAL OF QUANTITATIVE SPECTROSCOPY & RADIATIVE TRANSFER LA English DT Article ID DIELECTRONIC SATELLITE SPECTRA; DOUBLY EXCITED-STATES; COLLISION CROSS-SECTIONS; HELIUM-LIKE IONS; HE-LIKE; 2-ELECTRON SYSTEMS; RATE COEFFICIENTS; Z-DEPENDENCES; ENERGY-LEVELS; KEV AMU-1 AB Three different calculational methods (AUTOLSJ, MZ, MCDF) are used to obtain energy levels and autoionization rates for doubly-excited states 3l3l' of two electron systems (6 less than or equal to Z less than or equal to 54). By ordering all the states by energy within each block of a given angular momentum J and parity, it is possible to compare the autoionization rates obtained by the three methods. A comparison of the calculations is presented for Z = 18 and 26 and shows rather good agreement between the different methods. The Z dependences of the autoionizations rates are presented for the 3s3s S-1(0) state to show general trends. Using the AUTOLSJ and MZ methods, the energy levels for Z = 6 and 8 are presented and compared with experimental data and very accurate calculations using the methods of complex-rotation, close-coupling, B-spline, and Feshbach projection. C1 RUSSIAN ACAD SCI,LEBEDEV PHYS INST,MOSCOW 117924,RUSSIA. CENS,SPAM,F-91190 GIF SUR YVETTE,FRANCE. UNIV NEVADA,RENO,NV 89557. OBSERV PARIS,DARC,CNRS,UPR 176,F-92195 MEUDON,FRANCE. RUSSIAN ACAD SCI,INST SPECT,TROITSK 142092,RUSSIA. RP NILSEN, J (reprint author), LAWRENCE LIVERMORE NATL LAB,L-59,LIVERMORE,CA 94550, USA. RI Ivanov, Igor/F-8462-2014; Vainshtein, Leonid/N-5038-2015 NR 49 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 0022-4073 J9 J QUANT SPECTROSC RA JI J. Quant. Spectrosc. Radiat. Transf. PD DEC PY 1994 VL 52 IS 6 BP 729 EP 741 DI 10.1016/0022-4073(94)90038-8 PG 13 WC Optics; Spectroscopy SC Optics; Spectroscopy GA QE660 UT WOS:A1994QE66000003 ER PT J AU SCHIMEK, GL MCCARLEY, RE AF SCHIMEK, GL MCCARLEY, RE TI SYNTHESIS AND CHARACTERIZATION OF K0.19BA3.81MO22O34 - A QUATERNARY REDUCED MOLYBDENUM OXIDE CONTAINING METAL-METAL BONDED OLIGOMERS WITH 5 TRANS EDGE-SHARED MOLYBDENUM OCTAHEDRA SO JOURNAL OF SOLID STATE CHEMISTRY LA English DT Article ID CONDENSED MO6 OCTAHEDRA; CRYSTAL-STRUCTURE; CLUSTERS; CHAINS; OXOMOLYBDATES; COMPOUND; NAMO4O6; TERNARY; UNITS; IONS AB Crystals of K0.19Ba3.81Mo22O34, a metal-metal bonded oligomer in the series Mn-xMo4n+2O6n+4 with n = 5, have been synthesized. The Mo22 clusters consist of five trans edge-shared Mo octahedra. The dominant features of K0.19Ba3.81Mo22O34 include four short and four long apical-apical Mo bond distances within the cluster, relatively long intercluster metal-metal bond distances (> 2.99 angstrom), and cluster interconnections which have a stair-step arrangement from one Mo22 unit to the next. K0.19Ba3.81Mo22O34 crystallizes in the centrosymmetric space group P2(1/a), with lattice parameters of a = 9.908(2) angstrom, b = 9.353(2) angstrom, c = 15.951(3) angstrom, beta = 98.78(2)-degrees, Vol = 1460.8(4) angstrom3, Z = 2, and R = 0.0493 (R(w) = 0.0603) for 2768 reflections with I > 3.5 sigma(I). Five cations per formula unit can be accommodated in the pockets created by the interconnected Mo22O50 clusters. However, this phase has four fully occupied cation sites and one vacancy. The number of electrons available for metal-metal bonding (MCE) was derived from Mo-O bond valence sums around the molybdenum atoms (72(2)) and is in good agreement with the value calculated from formal oxidation states (71.8e). Mo-Mo bond order sums, excluding intercluster metal-metal interactions, although slightly high (MCE = 72.8(5)), indicate maximum utilization of electrons for Mo-Mo bonding. The magnetic susceptibility of this compound indicates that it is spin-paired with a small paramagnetic tail at low temperatures and a large residual chi(TIP) above 50 K. Electron spin resonance results indicate that the paramagnetic tail may be arising from molybdenum containing impurities, or defects, on which electrons are trapped. Structural and electronic comparisons to two known pentameric oligomers are discussed. (C) 1994 Academic Press, Inc. C1 IOWA STATE UNIV SCI & TECHNOL,US DOE,AMES LAB,AMES,IA 50011. IOWA STATE UNIV SCI & TECHNOL,DEPT CHEM,AMES,IA 50011. NR 29 TC 15 Z9 15 U1 0 U2 0 PU ACADEMIC PRESS INC JNL-COMP SUBSCRIPTIONS PI SAN DIEGO PA 525B STREET, SUITE 1900, SAN DIEGO, CA 92101-4495 SN 0022-4596 J9 J SOLID STATE CHEM JI J. Solid State Chem. PD DEC PY 1994 VL 113 IS 2 BP 345 EP 354 DI 10.1006/jssc.1994.1379 PG 10 WC Chemistry, Inorganic & Nuclear; Chemistry, Physical SC Chemistry GA PX186 UT WOS:A1994PX18600017 ER PT J AU HARRISON, WTA LIANG, CS NENOFF, TM STUCKY, GD AF HARRISON, WTA LIANG, CS NENOFF, TM STUCKY, GD TI SYNTHESIS AND CRYSTAL-STRUCTURE OF NANB2ASO8 SO JOURNAL OF SOLID STATE CHEMISTRY LA English DT Article ID NIOBIUM PHOSPHATE BRONZE; TUNNEL STRUCTURE; SERIES (K3NB6P4O26)N.KNB2PO8; KNB3P3O15 STRUCTURE; OPTICAL-PROPERTIES; MEMBER; PYROPHOSPHATE; FAMILY AB The high-temperature/high-pressure hydrothermal synthesis and X-ray single crystal structure of NaNb2AsO8 are reported. The title compound contains a three-dimensional network of NbO6, NbO5, and AsO4 groups, enclosing one-dimensional channels containing seven-coordinate guest sodium cations. UV/visible measurements on NaNb2AsO8 indicate two distinct absorption features at approximately 285 and approximately 360 nm. Crystals data for NaNb2AsO8: M(r) = 410.79, monoclinic, P2(1)/n (No. 14), a = 4.8970(6) angstrom, b = 8.516(2) angstrom, c = 15.075(3) angstrom, beta = 98.971(6)-degrees, V = 620.98 angstrom-3, Z = 4, R = 5.31%, R(W) = 5.15%, 2121 observed reflections (I > 3sigma(I)). (C) 1994 Academic Press, Inc. C1 UNIV CALIF SANTA BARBARA,DEPT CHEM,SANTA BARBARA,CA 93106. SANDIA NATL LABS,ALBUQUERQUE,NM 87185. RP HARRISON, WTA (reprint author), UNIV HOUSTON,DEPT CHEM,HOUSTON,TX 77204, USA. NR 36 TC 8 Z9 8 U1 0 U2 5 PU ACADEMIC PRESS INC JNL-COMP SUBSCRIPTIONS PI SAN DIEGO PA 525B STREET, SUITE 1900, SAN DIEGO, CA 92101-4495 SN 0022-4596 J9 J SOLID STATE CHEM JI J. Solid State Chem. PD DEC PY 1994 VL 113 IS 2 BP 367 EP 372 DI 10.1006/jssc.1994.1382 PG 6 WC Chemistry, Inorganic & Nuclear; Chemistry, Physical SC Chemistry GA PX186 UT WOS:A1994PX18600020 ER PT J AU BAKER, GA AF BAKER, GA TI THE MARKOV PROPERTY METHOD APPLIED TO ISING-MODEL CALCULATIONS SO JOURNAL OF STATISTICAL PHYSICS LA English DT Article DE MARKOV PROPERTY; ISING MODEL; CRITICAL PHENOMENA, PARALLEL COMPUTATIONAL PROCEDURES ID FIELD-THEORY; MONTE-CARLO AB An efficient method of computation for models possessing the Markov property is set out. We apply this method to the two-dimensional Ising model and report exact computations for up to 10 by 10 models with periodic boundary conditions. We find that critical-point, finite-size rounding is quite large in the renormalized coupling constant, which is not divergent at the critical point, in contrast to the energy, which is also not divergent and has no rounding there. The difference is traced to the continuity of the energy and the discontinuity of the renormalized coupling constant at the critical point. RP BAKER, GA (reprint author), LOS ALAMOS NATL LAB,DIV THEORET,LOS ALAMOS,NM 87545, USA. NR 18 TC 12 Z9 12 U1 0 U2 0 PU PLENUM PUBL CORP PI NEW YORK PA 233 SPRING ST, NEW YORK, NY 10013 SN 0022-4715 J9 J STAT PHYS JI J. Stat. Phys. PD DEC PY 1994 VL 77 IS 5-6 BP 955 EP 976 DI 10.1007/BF02183146 PG 22 WC Physics, Mathematical SC Physics GA PU016 UT WOS:A1994PU01600001 ER PT J AU TANG, Y AF TANG, Y TI COMPUTING RESPONSE OF TANKS WITH 2 LIQUIDS SO JOURNAL OF STRUCTURAL ENGINEERING-ASCE LA English DT Note AB A simplified procedure for computing the dynamic response of flexible tanks containing two liquids under a lateral base motion of arbitrary temporal variation is proposed. It requires the input of ground acceleration in the rigid tank solutions to be replaced by the pseudoacceleration function corresponding td the fundamental mode of vibration of the tank-liquid system. The procedure yields results with good accuracy for tanks with height-to-radius ratio ranging from 0.3 to 1.2, a practical range of height-to-radius ratio of most tanks. This simple procedure is an extension of the method used for the evaluation of response quantities for flexible tanks with only one liquid. Response quantities that may be computed by the proposed approach include the hydrodynamic pressure, base shear, base moment, and foundation moment. The effect of the soil-Structure interaction on the response quantities can be taken into account. Only the impulsive components of response quantities are considered in the proposed approach, since the convective components can be computed by considering both the tank and its supporting medium to be rigid. RP TANG, Y (reprint author), ARGONNE NATL LAB,9700 S CASS AVE,ARGONNE,IL 60439, USA. NR 4 TC 1 Z9 1 U1 0 U2 0 PU ASCE-AMER SOC CIVIL ENGINEERS PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017-2398 SN 0733-9445 J9 J STRUCT ENG-ASCE JI J. Struct. Eng.-ASCE PD DEC PY 1994 VL 120 IS 12 BP 3668 EP 3674 DI 10.1061/(ASCE)0733-9445(1994)120:12(3668) PG 7 WC Construction & Building Technology; Engineering, Civil SC Construction & Building Technology; Engineering GA PU382 UT WOS:A1994PU38200016 ER PT J AU HAN, Y VOILES, ET CHUMBLEY, LS AKINC, M NAIINI, AA VERKADE, JG AF HAN, Y VOILES, ET CHUMBLEY, LS AKINC, M NAIINI, AA VERKADE, JG TI SYNTHESIS AND CHARACTERIZATION OF ZINC-SULFIDE GALLIUM-PHOSPHIDE NANOCOMPOSITE POWDERS SO JOURNAL OF THE AMERICAN CERAMIC SOCIETY LA English DT Article ID MONOMERIC ARSINOGALLANE; SULFIDE POWDERS; PARTICLES; GOLD AB Nanocomposite powders between zinc sulfide and gallium phosphide were synthesized. Monodisperse, submicrometer, spherical, and porous clusters of ZnS nanocrystallites were used as a host material, into which a solution containing a phosphinogallane, [(t-Bu)(2)GaPR(2)](x) wherein R = i-Pr, x = 2 or R = t-Bu, x = 1, was impregnated. The pure ZnS powders and the composite powders obtained after flash pyrolysis at 600 degrees C were subsequently heat-treated at various temperatures ranging from 500 degrees to 900 degrees C and characterized using a variety of techniques. While pure ZnS powders undergo significant grain growth and morphology change at temperatures as low as 600 degrees C, the composite powders maintain their integrity up to 800 degrees C. C1 IOWA STATE UNIV SCI & TECHNOL, DEPT MAT SCI & ENGN, AMES, IA 50011 USA. IOWA STATE UNIV SCI & TECHNOL, AMES LAB, AMES, IA 50011 USA. IOWA STATE UNIV SCI & TECHNOL, DEPT CHEM, AMES, IA 50011 USA. NR 29 TC 3 Z9 6 U1 0 U2 4 PU WILEY-BLACKWELL PI HOBOKEN PA 111 RIVER ST, HOBOKEN 07030-5774, NJ USA SN 0002-7820 EI 1551-2916 J9 J AM CERAM SOC JI J. Am. Ceram. Soc. PD DEC PY 1994 VL 77 IS 12 BP 3153 EP 3160 DI 10.1111/j.1151-2916.1994.tb04564.x PG 8 WC Materials Science, Ceramics SC Materials Science GA QC570 UT WOS:A1994QC57000016 ER PT J AU VOILES, ET CHUMBLEY, LS HAN, Y AKINC, M AF VOILES, ET CHUMBLEY, LS HAN, Y AKINC, M TI TEM EXAMINATION OF HEAT-TREATED NANOCRYSTALLINE ZNS SO JOURNAL OF THE AMERICAN CERAMIC SOCIETY LA English DT Note ID SULFIDE POWDERS; ZINC-SULFIDE AB Monodisperse, spherical, submicrometer-size ZnS particles with nanocrystalline substructure were heated and examined in situ using a Gatan hot stage and a transmission electron microscope (TEM) at temperatures ranging from 500 degrees to 900 degrees C. The goal of this study was to observe the microstructural changes that occur in these particles during heat treatment. The particles, whose morphology consists of an agglomeration of nanocrystals, showed significant grain growth and sintering at temperatures as low as 600 degrees C, much lower than expected for bulk ZnS crystals. In addition, the particles were seen to develop hollow cores during heat treatment. This hollowing effect appears to be related to the nanocrystalline/nanoporous nature of the particles. C1 IOWA STATE UNIV SCI & TECHNOL,AMES LAB,AMES,IA 50011. RP VOILES, ET (reprint author), IOWA STATE UNIV SCI & TECHNOL,DEPT MAT SCI & ENGN,AMES,IA 50011, USA. NR 6 TC 3 Z9 3 U1 1 U2 4 PU AMER CERAMIC SOC 735 CERAMIC PLACE PI WESTERVILLE PA PO BOX 6136, WESTERVILLE, OH 43081-6136 SN 0002-7820 J9 J AM CERAM SOC JI J. Am. Ceram. Soc. PD DEC PY 1994 VL 77 IS 12 BP 3273 EP 3276 DI 10.1111/j.1151-2916.1994.tb04584.x PG 4 WC Materials Science, Ceramics SC Materials Science GA QC570 UT WOS:A1994QC57000036 ER PT J AU CHARLES, MJ MCLUCKEY, SA GLISH, GL AF CHARLES, MJ MCLUCKEY, SA GLISH, GL TI COMPETITION BETWEEN RESONANCE EJECTION AND ION DISSOCIATION DURING RESONANT EXCITATION IN A QUADRUPOLE ION-TRAP SO JOURNAL OF THE AMERICAN SOCIETY FOR MASS SPECTROMETRY LA English DT Article ID COLLISION-INDUCED DISSOCIATION; MASS-SPECTROMETRY; SIMULATION AB The competition between ion dissociation and ion ejection during resonant excitation in a quadrupole ion trap is investigated. Ions of similar mass but with a range of critical energies for the onset of dissociation have been examined. The effects of the amplitude and duration of the resonant excitation, the well depth in which the ions are trapped, and the pressure and nature of the collision gas are explored. Once the onset of ion ejection is reached, the rate of ion ejection increases with increased amplitude of the resonant excitation signal. The rate of ejection decreases or stays constant as a function of the duration of the resonant excitation, depending upon the ion species being excited. Increasing the trapping well depth increases the relative amount of dissociation versus ejection as does increasing the pressure of the bath gas. Adding heavier bath gases lowers the onset of ion dissociation and raises the onset of ion ejection. C1 OAK RIDGE NATL LAB,DIV ANALYT CHEM,OAK RIDGE,TN. RP CHARLES, MJ (reprint author), UNIV N CAROLINA,DEPT ENVIRONM SCI & ENGN,CHAPEL HILL,NC 27599, USA. RI McLuckey, Scott/B-2203-2009 OI McLuckey, Scott/0000-0002-1648-5570 NR 16 TC 56 Z9 56 U1 1 U2 12 PU ELSEVIER SCIENCE PUBL CO INC PI NEW YORK PA 655 AVENUE OF THE AMERICAS, NEW YORK, NY 10010 SN 1044-0305 J9 J AM SOC MASS SPECTR JI J. Am. Soc. Mass Spectrom. PD DEC PY 1994 VL 5 IS 12 BP 1031 EP 1041 DI 10.1016/1044-0305(94)85065-8 PG 11 WC Chemistry, Analytical; Chemistry, Physical; Spectroscopy SC Chemistry; Spectroscopy GA PY005 UT WOS:A1994PY00500001 PM 24226510 ER PT J AU LOO, RRO WINGER, BE SMITH, RD AF LOO, RRO WINGER, BE SMITH, RD TI PROTON-TRANSFER REACTION STUDIES OF MULTIPLY-CHARGED PROTEINS IN A HIGH MASS-TO-CHARGE RATIO QUADRUPOLE MASS-SPECTROMETER SO JOURNAL OF THE AMERICAN SOCIETY FOR MASS SPECTROMETRY LA English DT Article ID ION MOLECULE REACTIONS; INDUCED CONFORMATIONAL-CHANGES; ELECTROSPRAY-IONIZATION; INDUCED DISSOCIATION; AFFINITIES; MYOGLOBIN; EXCHANGE; WEIGHT; ACIDS AB Proton transfer reactions of multiply charged ions at high mass-to-charge ratios were explored with a low frequency quadrupole mass spectrometer. This instrument enabled a qualitative comparison of proton transfer reaction rates at low charge states for ions generated by electrospray ionization (ESI) from different solution conformations and for disulfide-linked versus disulfide-reduced protein ions. Proton transfer reactions that efficiently reduced the number of charges for ESI-generated ions to approximately the number of arginines in the polypeptide sequence were observed. No significant differences in gas-phase reaction rates were noted between different solution conformers. Differences in reaction rates between ''native'' and disulfide-reduced proteins were much smaller than those observed below m/z 2000 with lower proton affinity reagents or by using lower ; reagent concentrations. These smaller differences in reaction rates are thought to reflect the reduced electrostatic contributions from widely spaced charge sites and thus, the reduced sensitivity to an ion's three-dimensional structure or ''compactness.'' C1 PACIFIC NW LAB, DEPT CHEM SCI, CHEM METHODS & SEPARAT GRP, RICHLAND, WA 99352 USA. RI Smith, Richard/J-3664-2012 OI Smith, Richard/0000-0002-2381-2349 NR 36 TC 42 Z9 42 U1 0 U2 5 PU ELSEVIER SCIENCE PUBL CO INC PI NEW YORK PA 655 AVENUE OF THE AMERICAS, NEW YORK, NY 10010 SN 1044-0305 J9 J AM SOC MASS SPECTR JI J. Am. Soc. Mass Spectrom. PD DEC PY 1994 VL 5 IS 12 BP 1064 EP 1071 PG 8 WC Chemistry, Analytical; Chemistry, Physical; Spectroscopy SC Chemistry; Spectroscopy GA PY005 UT WOS:A1994PY00500003 ER PT J AU SCHMOYER, RL AF SCHMOYER, RL TI PERMUTATION TESTS FOR CORRELATION IN REGRESSION ERRORS SO JOURNAL OF THE AMERICAN STATISTICAL ASSOCIATION LA English DT Article DE DURBIN-WATSON TEST; LINEAR MODEL; REGRESSION; TRIANGULATION; VON NEUMANNS TEST ID INTERPOLATION AB This article is about tests for serial, spatial, or other correlation in e, the error vector in the linear model Y = X beta + e. The errors need not come from a particular parametric distribution such as the normal. P values are computed using permutations of the regression residuals. In the special cases that Y = e or X is a vector of 1s, the tests are valid and consistent. In general, regression residuals are not exchangeable, so the tests are only approximate. It is shown, however, that under mild conditions, the permutation tests are asymptotically valid and consistent. The test statistics are asymptotically normal. In the serial case, the tests are closely related to the Durbin-Watson (DW) test. The spatial case is illustrated with a test based on a triangulation of observation locations. In addition to providing a spatial analog to the DW test, the permutation tests circumvent two of the DW test's difficulties: dependency on the normality of errors and the need to accommodate ''indifference zones.'' RP SCHMOYER, RL (reprint author), OAK RIDGE NATL LAB,TECH STAFF,OAK RIDGE,TN 37831, USA. NR 33 TC 15 Z9 15 U1 1 U2 2 PU AMER STATISTICAL ASSOC PI ALEXANDRIA PA 1429 DUKE ST, ALEXANDRIA, VA 22314 SN 0162-1459 J9 J AM STAT ASSOC JI J. Am. Stat. Assoc. PD DEC PY 1994 VL 89 IS 428 BP 1507 EP 1516 DI 10.2307/2291013 PG 10 WC Statistics & Probability SC Mathematics GA PU330 UT WOS:A1994PU33000036 ER PT J AU OBLONSKY, LJ DEVINE, TM AGER, JW PERRY, SS MAO, XL RUSSO, RE AF OBLONSKY, LJ DEVINE, TM AGER, JW PERRY, SS MAO, XL RUSSO, RE TI SURFACE-ENHANCED RAMAN-SCATTERING FROM PYRIDINE ADSORBED ON THIN-LAYERS OF STAINLESS-STEEL SO JOURNAL OF THE ELECTROCHEMICAL SOCIETY LA English DT Article ID SEMICONDUCTOR ELECTRODE SURFACES; PASSIVE FILM; SILVER ELECTRODE; IRON SURFACE; SPECTROSCOPY; SPECTRA; INSITU; NICKEL; SPECTROELECTROCHEMISTRY; OVERLAYERS AB Surface-enhanced Raman scattering (SERS) has been detected for pyridine adsorbed onto the surface of thin (average thickness = 2.0 to 8.8 nm), continuous layers of stainless steel that were laser ablated onto roughened electrodes of silver. The experiments were performed on samples immersed in 0.1M KCl + 0.05M pyridine. The SER spectra changed with applied potential, and the intensities of the spectra decreased with increasing thickness of stainless steel. This procedure opens up SERS to the study of electrochemical phenomena at interfaces between alloys and a wide range of aqueous/gaseous environments. C1 UNIV CALIF BERKELEY,LAWRENCE BERKELEY LAB,BERKELEY,CA 94720. RP OBLONSKY, LJ (reprint author), UNIV CALIF BERKELEY,DEPT MAT SCI & MINERAL ENGN,BERKELEY,CA 94720, USA. OI Ager, Joel/0000-0001-9334-9751 NR 35 TC 20 Z9 22 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 DEC PY 1994 VL 141 IS 12 BP 3312 EP 3317 DI 10.1149/1.2059332 PG 6 WC Electrochemistry; Materials Science, Coatings & Films SC Electrochemistry; Materials Science GA PW605 UT WOS:A1994PW60500011 ER PT J AU WU, X ASOKAKUMAR, P LYNN, KG HEBERT, KR AF WU, X ASOKAKUMAR, P LYNN, KG HEBERT, KR TI DETECTION OF CORROSION-RELATED DEFECTS IN ALUMINUM USING POSITRON-ANNIHILATION SPECTROSCOPY SO JOURNAL OF THE ELECTROCHEMICAL SOCIETY LA English DT Article ID VARIABLE-ENERGY POSITRONS; SURFACE; ALLOYS; DISSOLUTION; INTERFACE; OXYGEN AB Near-surface atomic-scale defects in aluminum foils of at least 99.98% purity were characterized with positron annihilation spectroscopy measurements of the Doppler-broadening parameter S. Profiles of S vs. positron beam energy (i.e., vs. depth into the sample) were analyzed with a model for positron diffusion and trapping in order to characterize the defect layer structure. As-received foils were shown to possess a defect layer within 10 to 100 nm of the oxide film/metal interface. Both dissolution in aqueous sodium hydroxide solution and anodic pitting corrosion in HCl caused significant changes in the position spectra which were interpreted as increases in the defect population. On the basis of isochronal annealing, the defects were impurity-complexed voids or vacancy clusters, or else interfacial voids at the metal/film boundary located at surface roughness features. Either case suggests a possible role for the defects as pit sites, since both near-surface impurities and surface roughness are known to influence the number of pits on a surface. Defects found after pitting may be present in layers surrounding individual pits, and might have been produced in the process of pit initiation. C1 BROOKHAVEN NATL LAB,DEPT PHYS,UPTON,NY 11973. RP WU, X (reprint author), IOWA STATE UNIV SCI & TECHNOL,DEPT CHEM ENGN,AMES,IA 50011, USA. NR 39 TC 22 Z9 28 U1 0 U2 5 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 DEC PY 1994 VL 141 IS 12 BP 3361 EP 3368 DI 10.1149/1.2059340 PG 8 WC Electrochemistry; Materials Science, Coatings & Films SC Electrochemistry; Materials Science GA PW605 UT WOS:A1994PW60500019 ER PT J AU KAWAGOE, KT JOHNSON, DC AF KAWAGOE, KT JOHNSON, DC TI ELECTROCATALYSIS OF ANODIC OXYGEN-TRANSFER REACTIONS - OXIDATION OF PHENOL AND BENZENE AT BISMUTH-DOPED LEAD DIOXIDE ELECTRODES IN ACIDIC SOLUTIONS SO JOURNAL OF THE ELECTROCHEMICAL SOCIETY LA English DT Article ID ELECTROCHEMICAL OXIDATION; AQUEOUS PHENOL; FILMS; SURFACES; PURE AB The electrocatalytic activities are compared for pure beta-lead dioxide electrodes (PbO2) and bismuth-doped lead dioxide electrodes (Bi-PbO2) for oxidation of dimethylsulfoxide (DMSO), phenol, and benzene in acidic media. A correlation is observed between the bismuth content of Bi-PbO2 films on Au disk electrodes and the apparent heterogeneous rate constant for conversion of DMSO to DMSO(2). The oxidation of phenol occurs at a transport-limited rate for both the PbO2 and Bi-PbO2 film electrodes; however, the Bi-PbO2 electrodes exhibit significantly greater stability against surface fouling by polymeric films. This is a direct benefit of the greater electrocatalytic activity of Bi-PbO2 electrodes for oxidation of phenol beyond the phenolic radical. A ring-disk experiment for benzene oxidation at a Bi-PbO2 disk demonstrates that o-benzoquinone and p-benzoquinone (n(aff)=6 eq mol(-1)) are produced at the disk in the ratio ca. 0.25. However, the total ring current for reduction of these products from the disk reaction is significantly below that predicted from the disk current, and it must be concluded that a significant amount of electroinactive species is produced at the disk. This production is speculated to occur with n(aff)>6 eq mol(-1) and probably corresponds to a ring-opening reaction with production of one or more organic acids. The product solution from exhaustive electrolysis of benzene contains p-benzoquinone as the only electroactive product; hence, the o-benzoquinone is concluded to undergo further oxidation at the Bi-PbO2 electrode to one or more electroinactive products. C1 IOWA STATE UNIV SCI & TECHNOL,DEPT CHEM,AMES,IA 50011. IOWA STATE UNIV SCI & TECHNOL,AMES LAB,AMES,IA 50011. NR 26 TC 100 Z9 102 U1 0 U2 7 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 DEC PY 1994 VL 141 IS 12 BP 3404 EP 3409 DI 10.1149/1.2059345 PG 6 WC Electrochemistry; Materials Science, Coatings & Films SC Electrochemistry; Materials Science GA PW605 UT WOS:A1994PW60500024 ER PT J AU HOWARD, AJ RYE, RR RICCO, AJ RIEGER, DJ LOVEJOY, ML SLOAN, LR MITCHELL, MA AF HOWARD, AJ RYE, RR RICCO, AJ RIEGER, DJ LOVEJOY, ML SLOAN, LR MITCHELL, MA TI NEW METHODS FOR CIRCUIT FABRICATION ON POLY(TETRAFLUOROETHYLENE) SUBSTRATES SO JOURNAL OF THE ELECTROCHEMICAL SOCIETY LA English DT Article ID CU-TEFLON ADHESION; RADIATION; POLYTETRAFLUOROETHYLENE; DEPOSITION; COPPER AB By combining conventional integrated-circuit processing techniques with chemical etching for strong Cu film adhesion, three processes for the fabrication of the fine (<20 mu m, a factor of five smaller than existing technology), adherent, conducting features on poly(tetrafluoroethylene) (PTFE) substrates have been developed. Metal features are defined using a lift-off technology, electroless plating, or a combination of electroless and electroplating. The third process requires additional processing steps but is also the most versatile technique enabling 4 mu m thick metal features with high lateral resolution. These three processes result in a less expensive process for patterning metal features on an etched PFTE substrate with resolution of at least a factor of five better than existing processes. Adhesion of the metal features depends upon successful substrate preparation by etching the PTFE in a sodium naphalenide solution. Using the three processes discussed above, coupled-line quadrature (Lange) couplers that demonstrate equal power splitting between 5 and 14 GHz have been fabricated on a PTFE substrate. Lange couplers have extensive applications as passive hybrid device components in microwave and radio-frequency (RF) systems. RP HOWARD, AJ (reprint author), SANDIA NATL LABS,POB 5800,ALBUQUERQUE,NM 87185, USA. RI Ricco, Antonio/A-5273-2010; OI Ricco, Antonio/0000-0002-2355-4984 NR 18 TC 6 Z9 6 U1 0 U2 1 PU ELECTROCHEMICAL SOC INC PI PENNINGTON PA 10 SOUTH MAIN STREET, PENNINGTON, NJ 08534 SN 0013-4651 J9 J ELECTROCHEM SOC JI J. Electrochem. Soc. PD DEC PY 1994 VL 141 IS 12 BP 3556 EP 3561 DI 10.1149/1.2059369 PG 6 WC Electrochemistry; Materials Science, Coatings & Films SC Electrochemistry; Materials Science GA PW605 UT WOS:A1994PW60500048 ER PT J AU JOSOWICZ, M LI, J EXARHOS, GJ AF JOSOWICZ, M LI, J EXARHOS, GJ TI NOVEL ELECTROSYNTHESIS OF POLY(CYCLO-ORGANOPHASPHAZENES) SO JOURNAL OF THE ELECTROCHEMICAL SOCIETY LA English DT Letter AB A new polymerization process for the synthesis of cyclomatrix polymers directly from the hexachlorocyclophosphazene trimer, (NPCl2)(3), at an electrode surface is described. This electrochemical process is governed by the reductive coupling of an electrochemically generated reactive species from p-benzoquinone to the (NPCl2)(3) through a nucleophilic replacement of chlorine. Based on the results of elemental analysis, infrared spectroscopy, and Auger electron spectroscopy the molecular structure of the synthesized polymer has been inferred. The unique polymerization route makes this process viable for in situ synthesis of materials having a wide range of important physical and chemical properties. RP JOSOWICZ, M (reprint author), PACIFIC NW LAB, CTR MAT & CHEM SCI, RICHLAND, WA 99352 USA. NR 10 TC 3 Z9 3 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 DEC PY 1994 VL 141 IS 12 BP L162 EP L164 DI 10.1149/1.2059379 PG 3 WC Electrochemistry; Materials Science, Coatings & Films SC Electrochemistry; Materials Science GA PW605 UT WOS:A1994PW60500002 ER PT J AU BENICEWICZ, PK ROBERTS, JP TAYLOR, AJ AF BENICEWICZ, PK ROBERTS, JP TAYLOR, AJ TI SCALING OF TERAHERTZ RADIATION FROM LARGE-APERTURE BIASED PHOTOCONDUCTORS SO JOURNAL OF THE OPTICAL SOCIETY OF AMERICA B-OPTICAL PHYSICS LA English DT Article ID TIME-DOMAIN SPECTROSCOPY; FEMTOSECOND ELECTROMAGNETIC PULSES; MICROWAVE TRANSIENT RADIATION; AU-GE FILMS; SEMICONDUCTOR SURFACES; ANTENNA-ARRAY; OPTOELECTRONIC ANTENNAS; OPTICAL RECTIFICATION; ION-IMPLANTATION; DOPED SILICON AB We present a theoretical and experimental investigation into the generation of subpicosecond pulses of terahertz radiation from large-aperture biased photoconductors with 1.5-eV photon excitation. A model that describes the far-field radiation from the optically excited, biased photoconductor is developed. The peak of the radiated electric field as well as waveforms are presented as a function of optical excitation fluence and pulse width. The dependence of the terahertz radiation from biased InP and GaAs emitters on the applied bias field and on incident optical fluence for bias fields as high as 12 kV/cm and for optical fluences of 0.01-1.0 mJ/cm(2) is presented. For a given level of optical excitation the radiated electric field is predicted by theory to scale linearly with the applied bias field. This prediction is verified experimentally, with radiated-field strengths as high as 1.23 +/- 0.13 kV/cm being demonstrated. The radiated electric field also exhibits the monotonic saturation behavior predicted by theory, and saturation fluences of 0.058 +/- 0.015 and 0.018 +/- 0.008 mJ/cm(2) are obtained for InP and GaAs emitters, respectively. C1 LOS ALAMOS NATL LAB,DIV CHEM SCI TECHNOL,LOS ALAMOS,NM 87545. NR 76 TC 95 Z9 97 U1 1 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 DEC PY 1994 VL 11 IS 12 BP 2533 EP 2546 DI 10.1364/JOSAB.11.002533 PG 14 WC Optics SC Optics GA PX510 UT WOS:A1994PX51000026 ER PT J AU BOSTAK, JS VANDERWEIDE, DW BLOOM, DM AULD, BA OZBAY, E AF BOSTAK, JS VANDERWEIDE, DW BLOOM, DM AULD, BA OZBAY, E TI ALL-ELECTRONIC TERAHERTZ SPECTROSCOPY SYSTEM WITH TERAHERTZ FREE-SPACE PULSES SO JOURNAL OF THE OPTICAL SOCIETY OF AMERICA B-OPTICAL PHYSICS LA English DT Article ID TIME-DOMAIN SPECTROSCOPY; BAND-GAP; THZ; GENERATION; CONDUCTIVITY; RADIATION; ANTENNAS; BEAMS; FS AB We have developed all-electronic integrated circuits that generate and detect picosecond pulses. We have used these circuits with integrated antennas in a system capable of free-space spectroscopy in the terahertz regime. With this system we have measured magnitude- and phase-transmission characteristics for a variety of samples in the frequency range of 200 GHz-1 THz. C1 STANFORD UNIV,EL GINZTON LAB,STANFORD,CA 94305. IOWA STATE UNIV SCI & TECHNOL,AMES LAB,AMES,IA 50011. IOWA STATE UNIV SCI & TECHNOL,MICROELECTR RES CTR,AMES,IA 50011. RI Ozbay, Ekmel/B-9495-2008 NR 22 TC 9 Z9 9 U1 0 U2 0 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 DEC PY 1994 VL 11 IS 12 BP 2561 EP 2565 DI 10.1364/JOSAB.11.002561 PG 5 WC Optics SC Optics GA PX510 UT WOS:A1994PX51000029 ER PT J AU KARADI, C JAUHAR, S KOUWENHOVEN, LP WALD, K ORENSTEIN, J MCEUEN, PL AF KARADI, C JAUHAR, S KOUWENHOVEN, LP WALD, K ORENSTEIN, J MCEUEN, PL TI DYNAMIC-RESPONSE OF A QUANTUM POINT-CONTACT SO JOURNAL OF THE OPTICAL SOCIETY OF AMERICA B-OPTICAL PHYSICS LA English DT Article ID TRANSPORT; CONDUCTANCE; FIELDS AB We report measurements of the de current Delta I-dc generated across a nanometer-scale constriction, or a quantum point contact (QPC), in the two-dimensional electron gas in the GaAs-GaAlAs system. Delta I-dc Was induced by photoexcitation of the QPC in the terahertz regime. To our knowledge, these are the first measurements in which the induced current has been measured as a function of the excitation frequency omega. Spectra of Delta I-dc versus omega were obtained with a time-domain interferometer based on photoconductive (Auston) switch sources of pulsed terahertz radiation. The pulses were coupled to the gate that defines the QPC by a combination of quasi-optical techniques and a novel antenna-transmission-Line structure. The spectra are a strong function of the height of the barrier that creates the constriction, which suggests that photon-assisted transport is a possible mechanism for the induced de current. Measurements of the QPC response demonstrate the applicability of this technique to a variety of other mesoscopic structures, such as single and multiple quantum dots. C1 UNIV CALIF BERKELEY,LAWRENCE BERKELEY LAB,DIV MAT SCI,BERKELEY,CA 94720. UNIV TOKYO,ADV SCI & TECHNOL RES CTR,MEGURO KU,TOKYO 153,JAPAN. RP KARADI, C (reprint author), UNIV CALIF BERKELEY,DEPT PHYS,BERKELEY,CA 94720, USA. RI Orenstein, Joseph/I-3451-2015 NR 25 TC 17 Z9 17 U1 0 U2 3 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 DEC PY 1994 VL 11 IS 12 BP 2566 EP 2571 DI 10.1364/JOSAB.11.002566 PG 6 WC Optics SC Optics GA PX510 UT WOS:A1994PX51000030 ER PT J AU DYKHUIZEN, RC AF DYKHUIZEN, RC TI REVIEW OF IMPACT AND SOLIDIFICATION OF MOLTEN THERMAL SPRAY DROPLETS SO JOURNAL OF THERMAL SPRAY TECHNOLOGY LA English DT Review DE DROPLET SOLIDIFICATION; IMPACT MODELING; MADEJSKI MODEL; REVIEW; SPLASHING ID ATOMIZATION; SUBSTRATE; SURFACES AB The unique properties of coatings created by thermal spray deposition depend on the rapid solidification of individual splats created by impinging molten droplets. However, the impact process has been little studied because of the difficulty of measuring or numerically simulating the process, which occurs very quickly over a small area. Other scientific fields have investigated the impact of liquid droplets on solid surfaces, This paper reviews these studies, along with those conducted specifically on the thermal spray process, Modelers have almost universally ignored droplet solidification during impact; however, some experimental evidence suggests that the solidification process plays a significant role in splat formation, Splashing of impacting liquid droplets, another topic that has been largely ignored, affects deposition efficiency, porosity, and bond strength, and may also affect the amount of oxides incorporated in the coating, The scaling of data from impacting millimeter-size droplets traveling at low velocities to thermal spray conditions is questioned. C1 SANDIA NATL LABS,DEPT THERMAL & FLUID ENGN,ALBUQUERQUE,NM 87185. NR 55 TC 64 Z9 64 U1 0 U2 19 PU ASM INTERNATIONAL PI MATERIALS PARK PA SUBSCRIPTIONS SPECIALIST CUSTOMER SERVICE, MATERIALS PARK, OH 44073-0002 SN 1059-9630 J9 J THERM SPRAY TECHN JI J. Therm. Spray Technol. PD DEC PY 1994 VL 3 IS 4 BP 351 EP 361 DI 10.1007/BF02658980 PG 11 WC Materials Science, Coatings & Films SC Materials Science GA RB440 UT WOS:A1994RB44000005 ER PT J AU KIM, CH WINTON, JR LEONG, JC AF KIM, CH WINTON, JR LEONG, JC TI NEUTRALIZATION-RESISTANT VARIANTS OF INFECTIOUS HEMATOPOIETIC NECROSIS VIRUS HAVE ALTERED VIRULENCE AND TISSUE TROPISM SO JOURNAL OF VIROLOGY LA English DT Note ID RABIES VIRUS; MACROPHAGE TROPISM; CELL TROPISM; GLYCOPROTEIN; DETERMINANTS; GENE; PATHOGENICITY; PREDICTION; PROTEINS; SEQUENCE AB Infectious hematopoietic necrosis virus (IHNV) is a rhabdovirus that causes an acute disease in salmon and trout. In this study, a correlation between changes in tissue tropism and specific changes in the virus genome appeared to be made by examining four IHNV neutralization-resistant variants (RB-1, RB-2, RB-3, and RB-4) that had been selected with the glycoprotein (G)-specific monoclonal antibody RB/B5. These variants were compared with the parental strain (RB-76) for their virulence and pathogenicity in rainbow trout after waterborne challenge. Variants RB-2, RB-3, and RB-4 were only slightly attenuated and showed distributions of viral antigen in the livers and hematopoietic tissues of infected fish similar to those of the parental strain. Variant RB-1, however, was highly attenuated and the tissue distribution of viral antigen in RB-l-infected fish was markedly different, with more viral antigen in brain tissue. The sequences of the G genes of all four variants and RB-76 were determined. No significant changes were found for the slightly attenuated variants, but RB-1 G had two changes at amino acids 78 and 218 that dramatically altered its predicted secondary structure. These changes are thought to be responsible for the altered tissue tropism of the virus. Thus, IHNV G, like that of rabies virus and vesicular stomatitis virus, plays an integral part in the pathogenesis of viral infection. C1 OREGON STATE UNIV,DEPT MICROBIOL,CORVALLIS,OR 97331. OREGON STATE UNIV,SALMON DIS LAB,CORVALLIS,OR 97331. NATL BIOL SURVEY,PACIFIC NW NAT SCI CTR,SANDPOINT NAVAL STN,SEATTLE,WA. NR 31 TC 35 Z9 39 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 DEC PY 1994 VL 68 IS 12 BP 8447 EP 8453 PG 7 WC Virology SC Virology GA PR432 UT WOS:A1994PR43200096 PM 7525991 ER PT J AU LEHMAN, RF AF LEHMAN, RF TI SOME CONSIDERATIONS ON RESOLVING THE NORTH-KOREAN NUCLEAR QUESTION SO KOREAN JOURNAL OF DEFENSE ANALYSIS LA English DT Article AB Bringing Pyongyang into compliance with the NPT and its other nuclear obligations and keeping it there will require a persistent display of resolve by the international community, including strong leadership by the United States and the Republic of Korea. Both a sound legal architecture and major political change in the North must be achieved and sustained. The bilateral October 1994 US-North Korean agreement was intended to support both of these goals, but it contains within its structure and history elements which may work at cross purposes. Even if ultimately it helps resolve the Korean conflict satisfactorily, the impact of the October 1994 agreement elsewhere around the globe may complicate nuclear nonproliferation more than it helps. These negative effects can be reduced, however, and positive aspects of the agreement enhanced if the international community takes steps to strengthen the content of the anti-proliferation efforts now centered around the NPT and the dialogue between North and South Korea. That the necessary resolve will be displayed is not obvious. Given the political divisions within the world's democracies over the specifics of nonproliferation policies, the resurgence of the North-South dispute in the context of the NPT extension, and the spread of nuclear capability to nations less onerous or isolated than the DPRK, the international community's commitment to strong nonproliferation policies is not certain. Furthermore, success in dealing with North Korea's nuclear program is only a necessary, but not sufficient component of a successful global nonproliferation effort. The ultimate impact of the October 1994 US-DPRK agreement, like the final resolution of the Korean nuclear question, will not be seen for some time. Much will depend on how this agreement and that process are perceived and how they are implemented. Most importantly, success will be driven by attention to larger security, legal, political and economic considerations. One can imagine a very negative outcome if the consequences of the new agreement are to subsidize a totalitarian DPRK while failing to bring about significant political change, to undercut Seoul and/or the IAEA on inspections while failing to bring commensurate openness to the North, to call into question UN Security Council resolve on nonproliferation matters while encouraging other nations to pursue nuclear programs in order to extract concessions, to elevate Pyongyang's saber rattling to a rationale for concluding an agreement while leaving unresolved during a dangerous period of transition the question of North Korea's nuclear capability, etc. At the same time, if we do not forget these fundamental considerations, a positive outcome remains within reach. If a subsidized North Korean nuclear program does facilitate the end of dictatorship or the beginning of peaceful reunification it will enhance democracy and human rights to distant parts of the globe. If this disconcerting effort to ease Pyongyang out of its nuclear arms quest can be translated into a stronger nonproliferation regime worldwide, the risk from weapons of mass destruction may be greatly reduced. If the lession for the UN Security Council is that it must act sooner and with greater decisiveness toward threats to international security, and if it does peace will spread. Throughout all of this, the United States and the Republic of Korea, along with other friendly nations, must maintain the closest consultations to insure that this dangerous period of transition is navigated safely. RP LEHMAN, RF (reprint author), LAWRENCE LIVERMORE NATL LAB,LIVERMORE,CA 94550, USA. NR 5 TC 0 Z9 0 U1 0 U2 0 PU KOREAN INST DEFENSE ANALYSES PI SEOUL PA OFFICE RESEARCH COOPERATION, PO BOX 250, SEOUL 130-650, SOUTH KOREA SN 1016-3271 J9 KOREAN J DEF ANAL JI Korean J. Def. Anal. PD WIN PY 1994 VL 6 IS 2 BP 11 EP 33 PG 23 WC International Relations SC International Relations GA QG425 UT WOS:A1994QG42500001 ER PT J AU YEAKLEY, JA MOEN, RA BRESHEARS, DD NUNGESSER, MK AF YEAKLEY, JA MOEN, RA BRESHEARS, DD NUNGESSER, MK TI RESPONSE OF NORTH-AMERICAN ECOSYSTEM MODELS TO MULTIANNUAL PERIODICITIES IN TEMPERATURE AND PRECIPITATION SO LANDSCAPE ECOLOGY LA English DT Article DE CLIMATE CYCLES; FOREST ECOLOGY; GRASSLAND ECOLOGY; GAP MODELS; STEPPE; LINKAGES; TIME SERIES ANALYSIS; FREQUENCY ANALYSIS AB Ecosystem models typically use input temperature and precipitation data generated stochastically from weather station means and variances. Although the weather station data are based on measurements taken over a few decades, model simulations are usually on the order of centuries. Consequently, observed periodicities in temperature and precipitation at the continental scale that have been correlated with large-scale forcings, such as ocean-atmosphere dynamics and lunar and sunspot cycles, are ignored. We investigated how these natural climatic fluctuations affect aboveground biomass in ecosystem models by incorporating some of the more pronounced continental-scale cycles in temperature (4, 11, 80, 180 year periods) and precipitation (11 and 19 year periods) into models of three North American forests (using LINKAGES) and one North American grassland (using STEPPE). Even without inclusion of periodicities in climate, long-term dynamics of these models were characterized by internal frequencies resulting from vegetation birth, growth and death processes. Our results indicate that long-term temperature cycles result in significantly lower predictions of forest biomass than observed in the control case for a forest on a biome transition (northern hardwoods/boreal forest). Lower-frequency, higher-amplitude temprature oscillation caused amplification of forest biomass response in forests containing hardwood species. Shortgrass prairie and boreal ecosystems, dominated by species with broad stress tolerance ranges, were relatively insensitive to climatic oscillations. Our results suggest periodicities in climate should be incorporated within long-term simulations of ecosystems with strong internal frequencies, particularly for systems on biome transitions. C1 LOS ALAMOS NATL LAB,ENVIRONM SCI GRP,MAIL STOP J495,LOS ALAMOS,NM 87545. RI Moen, Ron/M-3177-2014; Breshears, David/B-9318-2009 OI Breshears, David/0000-0001-6601-0058 NR 0 TC 4 Z9 6 U1 1 U2 2 PU SPB ACADEMIC PUBLISHING BV PI AMSTERDAM PA PO BOX 11188, 1001 GD AMSTERDAM, NETHERLANDS SN 0921-2973 J9 LANDSCAPE ECOL JI Landsc. Ecol. PD DEC PY 1994 VL 9 IS 4 BP 249 EP 260 DI 10.1007/BF00129236 PG 12 WC Ecology; Geography, Physical; Geosciences, Multidisciplinary SC Environmental Sciences & Ecology; Physical Geography; Geology GA PX895 UT WOS:A1994PX89500002 ER PT J AU CHRYSSOMALAKOS, C ENGELDINGER, RA JURCO, B SCHLIEKER, M ZUMINO, B AF CHRYSSOMALAKOS, C ENGELDINGER, RA JURCO, B SCHLIEKER, M ZUMINO, B TI COMPLEX QUANTUM ENVELOPING-ALGEBRAS AS TWISTED TENSOR-PRODUCTS SO LETTERS IN MATHEMATICAL PHYSICS LA English DT Article AB We introduce a *-structure on the quantum double and its dual in order to make contact with various approaches to the enveloping algebras of complex quantum groups. Furthermore, we introduce a canonical basis in the quantum double, its universal R-matrices and give its relation to subgroups in the dual Hopf algebra. C1 CERN,DIV THEORY,CH-1211 GENEVA 23,SWITZERLAND. UNIV CALIF BERKELEY,DEPT PHYS,BERKELEY,CA 94720. LAWRENCE BERKELEY LAB,THEORET PHYS GRP,BERKELEY,CA 94720. RP CHRYSSOMALAKOS, C (reprint author), UNIV MUNICH,SEKT PHYS,LEHRSTUHL PROF WESS,THERESIENSTR 37,D-80333 MUNICH 2,GERMANY. NR 14 TC 1 Z9 1 U1 0 U2 0 PU KLUWER ACADEMIC PUBL PI DORDRECHT PA SPUIBOULEVARD 50, PO BOX 17, 3300 AA DORDRECHT, NETHERLANDS SN 0377-9017 J9 LETT MATH PHYS JI Lett. Math. Phys. PD DEC PY 1994 VL 32 IS 4 BP 275 EP 281 DI 10.1007/BF00761138 PG 7 WC Physics, Mathematical SC Physics GA PZ658 UT WOS:A1994PZ65800002 ER PT J AU WONG, STS ROOS, MS AF WONG, STS ROOS, MS TI A STRATEGY FOR SAMPLING ON A SPHERE APPLIED TO 3D SELECTIVE RF PULSE DESIGN SO MAGNETIC RESONANCE IN MEDICINE LA English DT Note DE MRI; 3D PULSE DESIGN; K-SPACE; INVERSION; SPIN-ECHO ID EXCITATION AB Conventional constant angular velocity sampling of the surface of a sphere results in a higher sampling density near the two poles relative to the equatorial region. More samples, and hence longer sampling time, are required to achieve a given sampling density in the equatorial region when compared with uniform sampling. This paper presents a simple expression for a continuous sample path through a nearly uniform distribution of points on the surface of a sphere. Sampling of concentric spherical shells in k-space with the new strategy is used to design 3D selective inversion and spin-echo purses. These new 3D selective pulses have been implemented and verified experimentally. C1 UNIV CALIF BERKELEY,DEPT RADIOL,BERKELEY,CA 94720. RP WONG, STS (reprint author), UNIV CALIF BERKELEY,LAWRENCE BERKELEY LAB,1 CYCLOTRON RD,MS 55-121,BERKELEY,CA 94720, USA. FU NHLBI NIH HHS [HL 25840] NR 11 TC 94 Z9 94 U1 0 U2 4 PU WILLIAMS & WILKINS PI BALTIMORE PA 351 WEST CAMDEN ST, BALTIMORE, MD 21201-2436 SN 0740-3194 J9 MAGNET RESON MED JI Magn.Reson.Med. PD DEC PY 1994 VL 32 IS 6 BP 778 EP 784 DI 10.1002/mrm.1910320614 PG 7 WC Radiology, Nuclear Medicine & Medical Imaging SC Radiology, Nuclear Medicine & Medical Imaging GA PV329 UT WOS:A1994PV32900013 PM 7869901 ER PT J AU WILLS, K JOHNSON, KM AF WILLS, K JOHNSON, KM TI HIGH-ACCURACY MEASUREMENTS OF TOTAL DISSOLVED INORGANIC CARBON IN THE OCEAN - COMPARISON OF ALTERNATE DETECTION METHODS - A COMMENT SO MARINE CHEMISTRY LA English DT Discussion RP WILLS, K (reprint author), BROOKHAVEN NATL LAB,DIV OCEANOG & ATMOSPHER SCI,UPTON,NY 11973, USA. NR 1 TC 1 Z9 3 U1 3 U2 5 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0304-4203 J9 MAR CHEM JI Mar. Chem. PD DEC PY 1994 VL 48 IS 1 BP 87 EP 88 DI 10.1016/0304-4203(94)90065-5 PG 2 WC Chemistry, Multidisciplinary; Oceanography SC Chemistry; Oceanography GA QB634 UT WOS:A1994QB63400008 ER PT J AU GOLDSTEIN, JLF MORRIS, JW AF GOLDSTEIN, JLF MORRIS, JW TI THE EFFECT OF SUBSTRATE ON THE MICROSTRUCTURE AND CREEP OF EUTECTIC IN-SN SO METALLURGICAL AND MATERIALS TRANSACTIONS A-PHYSICAL METALLURGY AND MATERIALS SCIENCE LA English DT Article ID INDIUM; TIN AB This study was conducted in order to determine and understand the effect of substrate on the behavior of eutectic In-Sn. Samples for mechanical testing were produced with either bare Cu or Ni on Cu substrates. Both the microstructure and the mechanical behavior are strongly dependent on substrate. When eutectic In-Sn is joined to bare Cu, Cu diffusion into the joint causes the alloy to become off-eutectic, giving a nonuniform and irregular microstructure. The addition of a layer of Ni acts as a diffusion barrier, preventing Cu diffusion sufficiently such that a uniform, normal colony-based eutectic forms. Deformation is more uniform in the In-Sn on Ni, while it is concentrated along the length of the joint in the In-Sn on Cu. This distinction is reflected in the different shapes of shear stress-strain curves between In-Sn on Cu and In-Sn on Ni. The stress exponents and activation energies for creep also vary with substrate. Creep deformation is governed by the In-rich beta phase for In-Sn on Cu and by the Sn-rich gamma phase for In-Sn on Ni. If In-Sn on Ni samples are aged, the microstructure coarsens and the mechanical behavior changes to resemble that of the as-cast In-Sn on Cu. C1 UNIV CALIF BERKELEY,DEPT MAT SCI & MINERAL ENGN,BERKELEY,CA 94720. UNIV CALIF BERKELEY,LAWRENCE BERKELEY LAB,BERKELEY,CA 94720. RP GOLDSTEIN, JLF (reprint author), NCHIP INC,SAN JOSE,CA 95132, USA. NR 15 TC 11 Z9 11 U1 1 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 DEC PY 1994 VL 25 IS 12 BP 2715 EP 2722 DI 10.1007/BF02649224 PG 8 WC Materials Science, Multidisciplinary; Metallurgy & Metallurgical Engineering SC Materials Science; Metallurgy & Metallurgical Engineering GA QB881 UT WOS:A1994QB88100018 ER PT J AU EIDEN, GC ANDERSON, JE NOGAR, NS AF EIDEN, GC ANDERSON, JE NOGAR, NS TI RESONANT LASER-ABLATION - SEMIQUANTITATIVE ASPECTS AND THRESHOLD EFFECTS SO MICROCHEMICAL JOURNAL LA English DT Article ID IONIZATION MASS-SPECTROMETRY; SPECTROSCOPY; DESORPTION; SENSITIVITY; EXCITATION; MICROPROBE; SOLIDS; GAAS C1 LOS ALAMOS NATL LAB,DIV CHEM SCI & TECHNOL,LOS ALAMOS,NM 87545. NR 36 TC 28 Z9 29 U1 1 U2 2 PU ACADEMIC PRESS INC JNL-COMP SUBSCRIPTIONS PI SAN DIEGO PA 525 B ST, STE 1900, SAN DIEGO, CA 92101-4495 SN 0026-265X J9 MICROCHEM J JI Microchem J. PD DEC PY 1994 VL 50 IS 3 BP 289 EP 300 DI 10.1006/mchj.1994.1095 PG 12 WC Chemistry, Analytical SC Chemistry GA PW819 UT WOS:A1994PW81900007 ER PT J AU POSNER, RG DEMBO, M AF POSNER, RG DEMBO, M TI BINDING OF BIVALENT LIGAND TO CELL-SURFACE IGE - CAN ONE DETECT RING FORMATION SO MOLECULAR IMMUNOLOGY LA English DT Article DE MONTE CARLO ANALYSIS; RING FORMATION ID BASOPHILIC LEUKEMIA-CELLS; HISTAMINE-RELEASE; DIVALENT HAPTENS; IMMUNOGLOBULIN-E; CLASS ANTIBODIES; DISSOCIATION KINETICS; DIMERIZATION KINETICS; RECEPTOR COMPLEXES; CROSS-LINKING; MEMBRANE AB It is well established that aggregation of cell surface immunoglobulin is involved in signal transduction by cells of the immune system. It is less well understood what special properties of these cell surface aggregates are important in initiating the signal cascade. Several authors have proposed that cells respond to the size (Fewtrell and Metzger (1980) J. Immun. 125, 701-710) as well as the stereochemistry (Ortega ct al. (1989) Eur. J. Immun. 19, 2251-2256) of receptor aggregates. One approach to arriving at data relevant to this question has been to construct simple bivalent ligands that can bind to surface immunoglobulin. Several authors have suggested that when these bivalent ligands interact with surface immunoglobulin the formation of small stable cyclic complexes is highly favored. In this paper we consider whether it is possible to completely determine the parameters that describe the binding of a bivalent ligand to a bivalent receptor with the available experimental technology. We show that with the appropriate analysis procedure, using a modified equivalent site model, these parameters can be reliably determined from only three experiments even when there is a large amount of ring formation. C1 LOS ALAMOS NATL LAB,THEORET BIOL & BIOPHYS GRP,DIV THEORET T10,LOS ALAMOS,NM 87545. RP POSNER, RG (reprint author), NO ARIZONA UNIV,DEPT CHEM,FLAGSTAFF,AZ 86011, USA. RI Dembo, Micah/C-2755-2013 FU NIAID NIH HHS [AI21002, AI35997] NR 22 TC 2 Z9 2 U1 0 U2 1 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD, ENGLAND OX5 1GB SN 0161-5890 J9 MOL IMMUNOL JI Mol. Immunol. PD DEC PY 1994 VL 31 IS 18 BP 1439 EP 1445 DI 10.1016/0161-5890(94)90160-0 PG 7 WC Biochemistry & Molecular Biology; Immunology SC Biochemistry & Molecular Biology; Immunology GA QC120 UT WOS:A1994QC12000007 PM 7823970 ER PT J AU LAMB, T LYDEARD, C AF LAMB, T LYDEARD, C TI A MOLECULAR PHYLOGENY OF THE GOPHER TORTOISES, WITH COMMENTS ON FAMILIAL RELATIONSHIPS WITHIN THE TESTUDINOIDEA SO MOLECULAR PHYLOGENETICS AND EVOLUTION LA English DT Article ID MITOCHONDRIAL-DNA; POPULATION BIOLOGY; SYSTEMATICS; EVOLUTION; RELEVANCE; SEQUENCES; TURTLES AB Sequences from the mitochondrial cytochrome b gene were obtained to examine molecular phylogenetic relationships among the North American gopher tortoises. Data from 352 aligned positions generated a single most-parsimonious tree for each of three analytical approaches: (1) equal weighting, all substitutions; (2) equal weighting, third position changes limited to transversions; and (3) transversions weighted 10 times transitions. Identical topologies for the resulting trees depict the gopher tortoises as a monophyletic group comprising two well-defined clades. Observed sequence divergence (7.0%) between the agassizii (Gopherus agassizii; G. berlandieri) and the polyphemus (G. flavomarginatus; G. polyphemus) clades suggests an Early Miocene separation of these lineages. The cytochrome b phylogeny complements some previous systematic interpretations, including formal taxonomic recognition of the two distinct groups, but is at odds with the most recent morphological analysis. Additional sequence comparisons of selected testudinoid (batagurid, emydid, and testudinid) taxa yielded a phylogeny consistent with a morphologically based hypothesis demonstrating close phylogenetic affinities between the Testudinidae and the ''Bataguridae.'' (C) 1994 Academic Press, Inc. C1 E CAROLINA UNIV, DEPT BIOL, GREENVILLE, NC 27858 USA. SAVANNAH RIVER ECOL LAB, AIKEN, SC 29802 USA. NR 30 TC 30 Z9 30 U1 4 U2 14 PU ACADEMIC PRESS INC ELSEVIER SCIENCE PI SAN DIEGO PA 525 B ST, STE 1900, SAN DIEGO, CA 92101-4495 USA SN 1055-7903 EI 1095-9513 J9 MOL PHYLOGENET EVOL JI Mol. Phylogenet. Evol. PD DEC PY 1994 VL 3 IS 4 BP 283 EP 291 DI 10.1006/mpev.1994.1036 PG 9 WC Biochemistry & Molecular Biology; Evolutionary Biology; Genetics & Heredity SC Biochemistry & Molecular Biology; Evolutionary Biology; Genetics & Heredity GA PX727 UT WOS:A1994PX72700001 PM 7697187 ER PT J AU MELENDREZ, CS MEIZEL, S BERGER, T AF MELENDREZ, CS MEIZEL, S BERGER, T TI COMPARISON OF THE ABILITY OF PROGESTERONE AND HEAT SOLUBILIZED PORCINE ZONA-PELLUCIDA TO INITIATE THE PORCINE SPERM ACROSOME REACTION IN-VITRO SO MOLECULAR REPRODUCTION AND DEVELOPMENT LA English DT Article DE PROGESTERONE; PORCINE; ZONA PELLUCIDA; SPERM; ACROSOME REACTION ID BOAR SPERM; EXOCYTOSIS; RECEPTOR; SURFACE; PLASMA; PIG AB It has been previously shown that progesterone can initiate the acrosome reaction (AR) of capacitated human and hamster sperm in vivo. We report here that progesterone can initiate a morphologically normal AR in porcine sperm that have undergone capacitation in a Hepes-buffered medium in vitro. In addition, we have compared the abilities of progesterone and heat-solubilized porcine zona pellucida (zona) to initiate the porcine sperm AR. Capacitated porcine sperm were treated with 1 mu g/ml progesterone, 150 mu g/ml porcine zona, or solvent control for 10 min. After treatment, sperm were incubated with the supravital dye Hoechst 33258, fixed and the acrosomal status determined in the previously viable sperm by fluorescence microscopy with fluorescein isothiocyanate-labeled Pisum sativum agglutinin (FITC-PSA). There was no significant difference between the percentage of AR initiated by zona compared to that initiated by progesterone. In order to determine whether there was a synergistic interaction between the two AR initiators, both were added simultaneously to capacitated porcine sperm at optimal (1 mu g/ml progesterone, 150 mu g/ml zona) and suboptimal (75 ng/ml progesterone and 75 mu g/ml zona) concentrations. Simultaneous addition of the two AR-initiators at the two concentrations stimulated an additive AR-initiating response, rather than a synergistic one. Several possible explanations for the additive results are discussed. (C) 1994 Wiley-Liss, Inc. C1 LAWRENCE LIVERMORE NATL LAB,SCH MED,DEPT CELL BIOL & HUMAN ANAT,DAVIS,CA 95616. LAWRENCE LIVERMORE NATL LAB,DEPT ANIM SCI,DAVIS,CA 95616. FU PHS HHS [23098] NR 23 TC 79 Z9 81 U1 0 U2 8 PU WILEY-LISS PI NEW YORK PA DIV JOHN WILEY & SONS INC 605 THIRD AVE, NEW YORK, NY 10158-0012 SN 1040-452X J9 MOL REPROD DEV JI Mol. Reprod. Dev. PD DEC PY 1994 VL 39 IS 4 BP 433 EP 438 PG 6 WC Biochemistry & Molecular Biology; Cell Biology; Developmental Biology; Reproductive Biology SC Biochemistry & Molecular Biology; Cell Biology; Developmental Biology; Reproductive Biology GA QH671 UT WOS:A1994QH67100011 PM 7893492 ER PT J AU MCCRIGHT, RD AF MCCRIGHT, RD TI METAL CONTAINER MATERIALS FOR NUCLEAR WASTE SO MRS BULLETIN LA English DT Article RP MCCRIGHT, RD (reprint author), LAWRENCE LIVERMORE NATL LAB,LIVERMORE,CA 94550, USA. NR 11 TC 0 Z9 0 U1 0 U2 0 PU MATERIALS RESEARCH SOCIETY PI PITTSBURGH PA 9800 MC KNIGHT ROAD SUITE 327, PITTSBURGH, PA 15237 SN 0883-7694 J9 MRS BULL JI MRS Bull. PD DEC PY 1994 VL 19 IS 12 BP 39 EP 42 PG 4 WC Materials Science, Multidisciplinary; Physics, Applied SC Materials Science; Physics GA PX405 UT WOS:A1994PX40500008 ER PT J AU SWIGER, RR MYHR, B TUCKER, JD AF SWIGER, RR MYHR, B TUCKER, JD TI THE LACZ TRANSGENE IN MUTA(TM)MOUSE MAPS TO CHROMOSOME-3 SO MUTATION RESEARCH LETTERS LA English DT Article DE MAPPING; FLUORESCENCE IN SITU HYBRIDIZATION; TRANSGENICS; LACZ; MUTA(TM)MOUSE ID MOUSE; DNA AB Transgenic mouse models are being used with increasing frequency for mutational and toxicological studies. One such system, MutaMouse, contains a stably integrated lambda-gt10LacZ shuttle vector in the mouse genome. We describe the use of dual color fluorescence in situ hybridization (FISH) with Mus musculus whole chromosome paints and lambda DNA to map the integration site of the lambda transgene to banc C on mouse chromosome 3. C1 LAWRENCE LIVERMORE NATL LAB,BIOL & BIOTECHNOL RES PROGRAM,LIVERMORE,CA 94551. HAZLETON WASHINGTON INC,VIENNA,VA 22182. NR 10 TC 17 Z9 18 U1 0 U2 0 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0165-7992 J9 MUTAT RES LETT JI Mutat. Res. Lett. PD DEC PY 1994 VL 325 IS 4 BP 145 EP 148 DI 10.1016/0165-7992(94)90077-9 PG 4 WC Genetics & Heredity; Toxicology SC Genetics & Heredity; Toxicology GA PX361 UT WOS:A1994PX36100005 PM 7527906 ER PT J AU PERETZ, F BOOTH, R AF PERETZ, F BOOTH, R TI ADVANCED NEUTRON SOURCE - US PLANS 330-MW RESEARCH REACTOR CENTER FOR 21ST-CENTURY SO NUCLEAR ENGINEERING INTERNATIONAL LA English DT Article RP PERETZ, F (reprint author), OAK RIDGE NATL LAB,POB 2009,OAK RIDGE,TN 37831, USA. NR 0 TC 0 Z9 0 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 DEC PY 1994 VL 39 IS 485 BP 30 EP 33 PG 4 WC Nuclear Science & Technology SC Nuclear Science & Technology GA PX060 UT WOS:A1994PX06000008 ER PT J AU FISCH, NJ HERRMANN, MC AF FISCH, NJ HERRMANN, MC TI UTILITY OF EXTRACTING ALPHA-PARTICLE ENERGY BY WAVES SO NUCLEAR FUSION LA English DT Article ID TOKAMAK; PLASMAS; ITER AB The utility of extracting a particle power, and then diverting this power to fast fuel ions, is investigated. As power is diverted to fast ions and then to ions, a number of effects come into play, as the relative amounts of pressure taken up by electrons, fuel ions and fast alpha particles shift. In addition, if the alpha particle power is diverted to fast fuel ions, there is an enhanced fusion reactivity because of the non-thermal component of the ion distribution. Some useful expressions for describing these effects are derived, and it is shown that fusion reactors with power density about twice what otherwise might be obtained can be contemplated, so long as a substantial amount of the alpha particle power can be diverted. Interestingly, in this mode of operation, once the electron heat is sufficiently confined, further improvement in confinement is actually not desirable. A similar improvement in fusion power density can be obtained for advanced fuel mixtures such as D-He-3, where the power of both the energetic alpha particles and the energetic protons might be diverted advantageously. RP FISCH, NJ (reprint author), PRINCETON UNIV,PRINCETON PLASMA PHYS LAB,POB 451,PRINCETON,NJ 08543, USA. NR 26 TC 49 Z9 49 U1 1 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 DEC PY 1994 VL 34 IS 12 BP 1541 EP 1556 DI 10.1088/0029-5515/34/12/I01 PG 16 WC Physics, Fluids & Plasmas SC Physics GA QC191 UT WOS:A1994QC19100001 ER PT J AU VAANDERING, EW SPINKA, HM HOFMANN, JS AF VAANDERING, EW SPINKA, HM HOFMANN, JS TI A POSSIBLE METHOD TO PRODUCE A POLARIZED ANTIPROTON BEAM AT INTERMEDIATE ENERGIES SO NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH SECTION A-ACCELERATORS SPECTROMETERS DETECTORS AND ASSOCIATED EQUIPMENT LA English DT Article ID PBARP ELASTIC-SCATTERING; TOTAL CROSS-SECTION; TO-IMAGINARY RATIO; C ANALYZING POWER; = 1.8 TEV; NUCLEON-ANTINUCLEON SCATTERING; INTERSECTING STORAGE-RINGS; CHARGE-EXCHANGE REACTION; MESON-BARYON DYNAMICS; NN PHASE-SHIFTS AB A possible technique to produce a polarized antiproton beam in the momentum range up to a few GeV/c is discussed. A high intensity separated beam of unpolarized antiprotons, such as the beams planned for a kaon factory, is required to produce the polarized antiproton beam. The types of spin observables that can be measured and the rates are described. A comparison is made with spin observables from an unpolarized antiproton beam incident on a polarized target. C1 ARGONNE NATL LAB, DIV HIGH ENERGY PHYS, ARGONNE, IL 60439 USA. VALPARAISO UNIV, DEPT PHYS, VALPARAISO, IN 46383 USA. NR 170 TC 2 Z9 2 U1 0 U2 0 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0168-9002 EI 1872-9576 J9 NUCL INSTRUM METH A JI Nucl. Instrum. Methods Phys. Res. Sect. A-Accel. Spectrom. Dect. Assoc. Equip. PD DEC 1 PY 1994 VL 351 IS 2-3 BP 266 EP 278 DI 10.1016/0168-9002(94)91353-6 PG 13 WC Instruments & Instrumentation; Nuclear Science & Technology; Physics, Nuclear; Physics, Particles & Fields SC Instruments & Instrumentation; Nuclear Science & Technology; Physics GA PU865 UT WOS:A1994PU86500004 ER PT J AU ACCIARRI, M ADAM, A ADRIANI, O AHLEN, S ALCARAZ, J AMBROSI, G BABUCCI, E BAKSAY, L BASCHIROTTO, A BATTISTON, R BAUR, W BAY, A BENCZE, GL BERTUCCI, B BIASINI, M BILEI, GM BOBBINK, GJ BOISSEVAIN, JG BOSETTI, M BROOKS, ML BURGER, WJ BUSENITZ, J CAMPS, C CARIA, M CASTELLINI, G CASTELLO, R CHECCUCCL, B CHEN, A COAN, TE COMMICHAU, V DIBITONTO, D DING, J DUINKER, P DJAMBAZOV, L EASO, S EXTERMANN, P FIANDRINI, E GABBANINI, A GOLDSTEIN, J GOUGAS, A HANGARTER, K HAUVILLER, C HERVE, A HOFER, M HOFER, T HOU, S JOSA, MI KAPUSTINSKY, JS KIM, D KINNISON, WW KIRST, H KORNIS, J KRASTEV, VR LADRON, P LANDI, G LEBEAU, M LECOMTE, P LEE, DM LEISTE, R LEJEUNE, E LIN, WT LOHMANN, W MARIN, A MASSETTI, R MILLS, GB NOWAK, H OKLE, M PASSALEVA, G PAUL, T PAULUZZI, M PENSOTTI, S PERRIN, E PRODUIT, N RANCOITA, PG RATTAGGI, M RICHEUX, JP SANTOCCHIA, A SIEDLING, R SACHWITZ, M SCHMITZ, P SCHONEICH, B SERVOLI, L SUBHAM, K SUSINNO, GF TERZA, G TESI, M THOMPSON, T TONISCH, F TOTH, J TROWITZSCH, G VIERTEL, G TUCHSCHERER, H VOGT, H WANG, S WALDMEIER, S WEILL, R XU, J YEH, SC ZHOU, B ZILIZI, G AF ACCIARRI, M ADAM, A ADRIANI, O AHLEN, S ALCARAZ, J AMBROSI, G BABUCCI, E BAKSAY, L BASCHIROTTO, A BATTISTON, R BAUR, W BAY, A BENCZE, GL BERTUCCI, B BIASINI, M BILEI, GM BOBBINK, GJ BOISSEVAIN, JG BOSETTI, M BROOKS, ML BURGER, WJ BUSENITZ, J CAMPS, C CARIA, M CASTELLINI, G CASTELLO, R CHECCUCCL, B CHEN, A COAN, TE COMMICHAU, V DIBITONTO, D DING, J DUINKER, P DJAMBAZOV, L EASO, S EXTERMANN, P FIANDRINI, E GABBANINI, A GOLDSTEIN, J GOUGAS, A HANGARTER, K HAUVILLER, C HERVE, A HOFER, M HOFER, T HOU, S JOSA, MI KAPUSTINSKY, JS KIM, D KINNISON, WW KIRST, H KORNIS, J KRASTEV, VR LADRON, P LANDI, G LEBEAU, M LECOMTE, P LEE, DM LEISTE, R LEJEUNE, E LIN, WT LOHMANN, W MARIN, A MASSETTI, R MILLS, GB NOWAK, H OKLE, M PASSALEVA, G PAUL, T PAULUZZI, M PENSOTTI, S PERRIN, E PRODUIT, N RANCOITA, PG RATTAGGI, M RICHEUX, JP SANTOCCHIA, A SIEDLING, R SACHWITZ, M SCHMITZ, P SCHONEICH, B SERVOLI, L SUBHAM, K SUSINNO, GF TERZA, G TESI, M THOMPSON, T TONISCH, F TOTH, J TROWITZSCH, G VIERTEL, G TUCHSCHERER, H VOGT, H WANG, S WALDMEIER, S WEILL, R XU, J YEH, SC ZHOU, B ZILIZI, G TI THE L3 SILICON MICROVERTEX DETECTOR SO NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH SECTION A-ACCELERATORS SPECTROMETERS DETECTORS AND ASSOCIATED EQUIPMENT LA English DT Article ID PERFORMANCE; SYSTEM AB The design and construction of the silicon strip microvertex detector (SMD) of the L3 experiment at LEP are described. We present the sensors, readout electronics, data acquisition system, mechanical assembly and support, displacement monitoring systems and radiation monitoring system of the recently installed double-sided, double-layered SMD. This detector utilizes novel and sophisticated techniques for its readout. C1 LOS ALAMOS NATL LAB, LOS ALAMOS, NM 87545 USA. RHEIN WESTFAL TH AACHEN, INST PHYS 1, D-52056 AACHEN, GERMANY. RHEIN WESTFAL TH AACHEN, INST PHYS 3, D-52056 AACHEN, GERMANY. NIKHEF H, NATL INST HIGH ENERGY PHYS, 1009 DB AMSTERDAM, NETHERLANDS. JOHNS HOPKINS UNIV, BALTIMORE, MD 21218 USA. BOSTON UNIV, BOSTON, MA 02215 USA. HUNGARIAN ACAD SCI, CENT RES INST PHYS, H-1525 BUDAPEST 114, HUNGARY. IST NAZL FIS NUCL, FIRENZE SEZ, I-50125 FLORENCE, ITALY. IST NAZL FIS NUCL, INST RIC ONDE ELETTROMAGNET, I-50125 FLORENCE, ITALY. CERN, EUROPEAN LAB PARTICLE PHYS, CH-1211 GENEVA 23, SWITZERLAND. UNIV GENEVA, DPNC, CH-1211 GENEVA 4, SWITZERLAND. UNIV LAUSANNE, CH-1015 LAUSANNE, SWITZERLAND. IST NAZL FIS NUCL, MILAN SEZ, I-20133 MILAN, ITALY. UNIV PERUGIA, I-06100 PERUGIA, ITALY. NATL CENT UNIV, CHUNGLI 32054, TAIWAN. NATL TSING HUA UNIV, HSINCHU 30043, TAIWAN. UNIV ALABAMA, TUSCALOOSA, AL 35486 USA. DESY, INST HOCHENERGIEPHYS, D-15738 ZEUTHEN, GERMANY. ETH ZURICH, CH-8093 ZURICH, SWITZERLAND. LAB ANNECY LE VIEUX PHYS PARTICULES, LAPP, IN2P3, CNRS, BP 110, F-74941 ANNECY LE VIEUX, FRANCE. KOSSUTH EGYETEM, KISERETI FIZIKA, DEBRECEN, HUNGARY. RI Fiandrini, Emanuele/C-4549-2008; Servoli, Leonello/E-6766-2012; bertucci, bruna/J-5237-2012; Josa, Isabel/K-5184-2014; Rancoita, Pier Giorgio/J-9896-2015; OI 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; Goldstein, Joel/0000-0003-1591-6014 NR 14 TC 226 Z9 227 U1 0 U2 5 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 DEC 1 PY 1994 VL 351 IS 2-3 BP 300 EP 312 DI 10.1016/0168-9002(94)91357-9 PG 13 WC Instruments & Instrumentation; Nuclear Science & Technology; Physics, Nuclear; Physics, Particles & Fields SC Instruments & Instrumentation; Nuclear Science & Technology; Physics GA PU865 UT WOS:A1994PU86500008 ER PT J AU BAGDASAROV, SL COX, PT DEMORTIER, L GIOKARIS, ND KHAZINS, DM ALBROW, MG ANDERSON, DF CIHANGIR, S ZIMMERMAN, J FANOURAKIS, G LOBKOWICZ, F GUSTAFSON, HR BUDAGOV, JA TOKAR, S MORGAN, M AF BAGDASAROV, SL COX, PT DEMORTIER, L GIOKARIS, ND KHAZINS, DM ALBROW, MG ANDERSON, DF CIHANGIR, S ZIMMERMAN, J FANOURAKIS, G LOBKOWICZ, F GUSTAFSON, HR BUDAGOV, JA TOKAR, S MORGAN, M TI BEAM TEST OF A HADRON CALORIMETER MADE OF HIGH-PRESSURE GAS-IONIZATION TUBES SO NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH SECTION A-ACCELERATORS SPECTROMETERS DETECTORS AND ASSOCIATED EQUIPMENT LA English DT Article AB A hadron calorimeter based on high-pressure gas-ionization tubes arranged nearly parallel to the incident particle direction was built and tested in pion and electron beams at the CERN SPS. Data were taken in the energy range of 10 to 100 GeV with the calorimeter tilted to the beam axis at angles varying from 0.9 degrees to 9.1 degrees. Results of the calorimeter response to pions and electrons and its energy resolution as a function of electric field, gas pressure, beam energy, and tilt angle are presented. The calorimeter was developed for the forward region of high energy and high luminosity hadron colliders. It proved to be simple and easy to operate. Its parameters meet the needs of forward calorimetry for LHC collider experiments. C1 ROCKEFELLER UNIV,DEPT EXPTL PHYS,NEW YORK,NY 10021. FERMILAB NATL ACCELERATOR LAB,BATAVIA,IL 60510. UNIV ROCHESTER,DEPT PHYS & ASTRON,ROCHESTER,NY 14627. UNIV MICHIGAN,ANN ARBOR,MI 48109. JOINT INST NUCL RES,DUBNA 101000,RUSSIA. ABIL ENGN TECHNOL INC,S HOLLAND,IL 60473. FERMILAB NATL ACCELERATOR LAB,BATAVIA,IL 60510. NR 14 TC 1 Z9 1 U1 0 U2 0 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0168-9002 J9 NUCL INSTRUM METH A JI Nucl. Instrum. Methods Phys. Res. Sect. A-Accel. Spectrom. Dect. Assoc. Equip. PD DEC 1 PY 1994 VL 351 IS 2-3 BP 336 EP 344 DI 10.1016/0168-9002(94)91361-7 PG 9 WC Instruments & Instrumentation; Nuclear Science & Technology; Physics, Nuclear; Physics, Particles & Fields SC Instruments & Instrumentation; Nuclear Science & Technology; Physics GA PU865 UT WOS:A1994PU86500012 ER PT J AU HELMER, RG PUTNAM, MH GREENWOOD, RC WILLMES, H AF HELMER, RG PUTNAM, MH GREENWOOD, RC WILLMES, H TI METHODOLOGY FOR THE MEASUREMENT OF BETA-DECAY INTENSITY DISTRIBUTIONS FROM THE ANALYSIS OF TOTAL ABSORPTION GAMMA-RAY SPECTRA SO NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH SECTION A-ACCELERATORS SPECTROMETERS DETECTORS AND ASSOCIATED EQUIPMENT LA English DT Article ID SPECTROMETER AB A total absorption gamma-ray spectrometer (TAGS), based on a 25.4-cm diameter X 30.5-cm long NaI(Tl) well detector, has been developed at the INEL on-line isotope separator facility. A Si detector in the well of the NaI(Tl) detector allows one to collect beta-particle-gated coincidence gamma spectra in addition to singles gamma spectra. From the analysis of these total absorption gamma-ray spectra, beta(-)-decay intensity distributions are obtained. The analysis methodology is based on response functions that simulate the response of the NaI(Tl) detector to the gamma-rays and electrons (including external bremsstrahlung) from a radioactive source in the detector well. These response functions are computed with a Monte Carlo photon and electron transport code. This methodology has been completely upgraded since it was first developed and now provides very good simulations of both singles and coincidence spectra. As an example of the application of this methodology, the I-beta distribution for the decay of Cs-141 is determined from the TAGS spectra. C1 UNIV IDAHO,DEPT PHYS,MOSCOW,ID 83844. RP HELMER, RG (reprint author), EG&G IDAHO INC,IDAHO NATL ENGN LAB,POB 1625,IDAHO FALLS,ID 83415, USA. NR 18 TC 10 Z9 10 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 DEC 1 PY 1994 VL 351 IS 2-3 BP 406 EP 422 DI 10.1016/0168-9002(94)91370-6 PG 17 WC Instruments & Instrumentation; Nuclear Science & Technology; Physics, Nuclear; Physics, Particles & Fields SC Instruments & Instrumentation; Nuclear Science & Technology; Physics GA PU865 UT WOS:A1994PU86500021 ER PT J AU YU, Z SEGEL, RE CHEN, FJ HEIMBERG, P BENT, RD BLOMGREN, J NANN, H SUN, C REHM, KE HARDIE, G BROWN, JD JACOBSEN, E HOMOLKA, J SCHNEIDER, R AF YU, Z SEGEL, RE CHEN, FJ HEIMBERG, P BENT, RD BLOMGREN, J NANN, H SUN, C REHM, KE HARDIE, G BROWN, JD JACOBSEN, E HOMOLKA, J SCHNEIDER, R TI A READOUT SYSTEM FOR MICROSTRIP SILICON DETECTORS SO NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH SECTION A-ACCELERATORS SPECTROMETERS DETECTORS AND ASSOCIATED EQUIPMENT LA English DT Article AB A readout system for Si microstrip detectors has been developed in which inductors are placed between each strip thus forming an LC delay line with the detector's intrinsic capacitance. Each strip in a 50-strip detector is resolved and a time resolution of 800 ps is obtained with 5.49 MeV alpha particles. Only two fast signals and an energy signal are needed from an entire detector in order to determine a particle's time of arrival, position and energy. The system requires little power and is made of components that are available commercially. C1 NORTHWESTERN UNIV,DEPT PHYS & ASTRON,EVANSTON,IL 60201. INDIANA UNIV,CYCLOTRON FACIL,BLOOMINGTON,IN 47408. INDIANA UNIV,DEPT PHYS,BLOOMINGTON,IN 47408. ARGONNE NATL LAB,DIV PHYS,ARGONNE,IL 60439. WESTERN MICHIGAN UNIV,DEPT PHYS,KALAMAZOO,MI 49008. PRINCETON UNIV,DEPT PHYS,PRINCETON,NJ 08540. TECH UNIV MUNICH,DEPT PHYS,W-8000 MUNICH,GERMANY. RI Homolka, Josef/D-1843-2009; OI Homolka, Josef/0000-0001-8565-0907 NR 3 TC 2 Z9 2 U1 0 U2 0 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0168-9002 J9 NUCL INSTRUM METH A JI Nucl. Instrum. Methods Phys. Res. Sect. A-Accel. Spectrom. Dect. Assoc. Equip. PD DEC 1 PY 1994 VL 351 IS 2-3 BP 460 EP 462 DI 10.1016/0168-9002(94)91374-9 PG 3 WC Instruments & Instrumentation; Nuclear Science & Technology; Physics, Nuclear; Physics, Particles & Fields SC Instruments & Instrumentation; Nuclear Science & Technology; Physics GA PU865 UT WOS:A1994PU86500025 ER PT J AU IPE, NE FASSO, A AF IPE, NE FASSO, A TI GAS BREMSSTRAHLUNG CONSIDERATIONS IN THE SHIELDING DESIGN OF THE ADVANCED PHOTON SOURCE SYNCHROTRON-RADIATION BEAM LINES SO NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH SECTION A-ACCELERATORS SPECTROMETERS DETECTORS AND ASSOCIATED EQUIPMENT LA English DT Article AB The Advanced Photon Source (APS) currently under construction at Argonne National Laboratory will be one of the world's brightest synchrotron radiation (SR) facilities. The storage ring, capable of storing currents up to 300 mA at 7.0 GeV, or 200 mA at 7.5 GeV, will produce very intense and energetic synchrotron radiation (E(c) = 24 keV for bending magnets, and E(c) = 37.4 keV for wigglers, where E(c) is the critical energy). The synchrotron radiation beam lines, consisting of experimental enclosures and transport lines, will have to be shielded against synchrotron radiation and gas bremsstrahlung scattered from beam line components. For insertion devices placed in the straight sections (length = 15 m), the gas bremsstrahlung produced by the interaction of the primary stored beam with residual gas molecules or ions in the storage ring vacuum chamber dominates the SR beam line shielding. Gas bremsstrahlung in the forward direction will be stopped by a tungsten beam stop, 18 cm thick, located at the back of the experimental enclosure and placed in the median plane of the storage ring. The forward-directed gas bremsstrahlung is characterized, and the effectiveness of the tungsten beam stop is assessed. The Monte Carlo code FLUKA was used to determine the dose equivalent rates from gas bremsstrahlung in a cylindrical tissue phantom with and without the tungsten beam stop. Simulations were performed using an air target of length 15 m at a pressure of 1 atm and 1/10 atm (1 atm = 101.325 kPa = 760 torr) both with and without suppressing positron multiple scattering (M.S.) and Bhabha and Mailer scattering in the air target. At a given pressure the dose equivalent rates are higher without positron multiple scattering in the air target than with multiple scattering. For simulations at P-s = 1 atm, the minimization of Bhabha/Moller scattering is important for areas with scoring radii less than 0.4 cm. The maximum dose equivalent rate (for E(0) = 7 Gev, I = 300 mA, and P = 0.133 mu Pa or 10(-9) torr) in the phantom (at a depth of 29.5 cm) for a scoring area of 0.0013 cm(2) (radius = 0.02 cm) is 2.1 Sv/h, whereas for a scoring area of 0.5 cm(2) (radius = 0.4 cm) it is 0.57 Sv/h. Scoring photon fluence and converting it to dose equivalent using Rogers' fluence-to-dose equivalent conversion factors results in an overestimation of dose equivalent. The maximum dose equivalent rate behind the tungsten beam stop, at a depth of 2.5 cm in the tissue, is 0.1 + 0.04 mu Sv/h for a scoring radius of 1 cm. The corresponding dose equivalent rates without the stop are 32 mSv/h (depth = 2.5 cm) and 0.17 Sv/h (depth = 29.5 cm). A simple expression has been derived for the upper limit on the dose equivalent that an individual can receive due to loss of vacuum in the straight section. C1 CERN,RP,TIS,CH-1211 GENEVA 23,SWITZERLAND. RP IPE, NE (reprint author), STANFORD UNIV,STANFORD LINEAR ACCELERATOR CTR,DEPT RADIAT PHYS,STANFORD,CA 94309, USA. NR 16 TC 15 Z9 15 U1 0 U2 4 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0168-9002 J9 NUCL INSTRUM METH A JI Nucl. Instrum. Methods Phys. Res. Sect. A-Accel. Spectrom. Dect. Assoc. Equip. PD DEC 1 PY 1994 VL 351 IS 2-3 BP 534 EP 544 DI 10.1016/0168-9002(94)91383-8 PG 11 WC Instruments & Instrumentation; Nuclear Science & Technology; Physics, Nuclear; Physics, Particles & Fields SC Instruments & Instrumentation; Nuclear Science & Technology; Physics GA PU865 UT WOS:A1994PU86500034 ER PT J AU POLKINGHORNE, ST AF POLKINGHORNE, ST TI VALIDATION OF THE ATR-SINDA FUEL PLATE MODEL USING ADVANCED TEST REACTOR STARTUP DATA SO NUCLEAR TECHNOLOGY LA English DT Article AB The ability of the ATR-SINDA fuel plate model to predict the thermal behavior of Advanced Test Reactor (ATR) fuel plates under steady-state and transient conditions is demonstrated. Computer-generated results from ten steady-state calculations and two transient calculations are compared with experimental data obtained during ATR startup tests. The calculations simulate natural convection, forced convection, flow reversal, and flow instability in specially instrumented fuel elements. Calculated temperatures are generally within 10 K of measured temperatures, confirming that ATR-SINDA is suitable for analyzing plate-type fuel. RP POLKINGHORNE, ST (reprint author), EG&G IDAHO INC,IDAHO NATL ENGN LAB,NUCL RES & ENGN GRP,POB 1625,IDAHO FALLS,ID 83415, USA. NR 13 TC 5 Z9 5 U1 0 U2 0 PU AMER NUCLEAR SOCIETY PI LA GRANGE PK PA 555 N KENSINGTON AVENUE, LA GRANGE PK, IL 60525 SN 0029-5450 J9 NUCL TECHNOL JI Nucl. Technol. PD DEC PY 1994 VL 108 IS 3 BP 395 EP 412 PG 18 WC Nuclear Science & Technology SC Nuclear Science & Technology GA PU419 UT WOS:A1994PU41900009 ER PT J AU NGUYEN, HD PAIK, SH DOUGLASS, RW AF NGUYEN, HD PAIK, SH DOUGLASS, RW TI STUDY OF DOUBLE-DIFFUSIVE CONVECTION IN LAYERED ANISOTROPIC POROUS-MEDIA SO NUMERICAL HEAT TRANSFER PART B-FUNDAMENTALS LA English DT Article ID NATURAL-CONVECTION; HEAT-TRANSFER; MASS AB Natural convection induced by combined heat and mass transfer in an enclosure filled with two layers of anisotropic porous media saturated with a two-component fluid is investigated by means of numerical experiments. Darcy's law together with the energy and specie equations are solved by a domain decomposition and a pseudo-spectral method using Chebyshev polynomials as the basis function. The interactions between the subdomains along the interface are decoupled by a superposition of elementary solutions. Four cases including aiding, opposing, cross diffusion with stabilizing, and destabilizing concentration fields are considered. The results show remarkable differences among the flow, temperature, and concentration fields. Depending on the orientation of the boundary conditions of the temperature and concentration fields, the overall heat transfer rates may or may not be sensitive to the Rayleigh numbers. RP NGUYEN, HD (reprint author), EG&G IDAHO INC,IDAHO NATL ENGN LAB,POB 1625,MS 3808,IDAHO FALLS,ID 83415, USA. NR 23 TC 15 Z9 15 U1 0 U2 1 PU HEMISPHERE PUBL CORP PI BRISTOL PA 1900 FROST ROAD, SUITE 101, BRISTOL, PA 19007-1598 SN 1040-7790 J9 NUMER HEAT TR B-FUND JI Numer Heat Tranf. B-Fundam. PD DEC PY 1994 VL 26 IS 4 BP 489 EP 505 DI 10.1080/10407799408914942 PG 17 WC Thermodynamics; Mechanics SC Thermodynamics; Mechanics GA PX138 UT WOS:A1994PX13800008 ER PT J AU RODRIGUEZ, G CACERES, SR TAYLOR, AJ AF RODRIGUEZ, G CACERES, SR TAYLOR, AJ TI MODELING OF TERAHERTZ RADIATION FROM BIASED PHOTOCONDUCTORS - TRANSIENT VELOCITY EFFECTS SO OPTICS LETTERS LA English DT Article ID ELECTROMAGNETIC PULSES; GENERATION AB We include transient carrier velocity dynamics in a model describing the terahertz radiation from a large-aperture, by an ultrashort optical pulse. Waveforms of the radiated electric field are calculated as a function of optical excitation fluence and bias field. The model is applied to terahertz generation in biased GaAs photoconductors. RP RODRIGUEZ, G (reprint author), LOS ALAMOS NATL LAB,MS E543,LOS ALAMOS,NM 87545, USA. RI Rodriguez, George/G-7571-2012 OI Rodriguez, George/0000-0002-6044-9462 NR 7 TC 22 Z9 22 U1 0 U2 5 PU OPTICAL SOC AMER PI WASHINGTON PA 2010 MASSACHUSETTS AVE NW, WASHINGTON, DC 20036 SN 0146-9592 J9 OPT LETT JI Opt. Lett. PD DEC 1 PY 1994 VL 19 IS 23 BP 1994 EP 1996 DI 10.1364/OL.19.001994 PG 3 WC Optics SC Optics GA PU974 UT WOS:A1994PU97400026 PM 19855720 ER PT J AU GOLD, DM AF GOLD, DM TI DIRECT MEASUREMENT OF PREPULSE SUPPRESSION BY USE OF A PLASMA SHUTTER SO OPTICS LETTERS LA English DT Article ID CHIRPED-PULSE AMPLIFICATION; ND-GLASS LASER; ULTRASHORT; EXPANSION AB A direct measurement is presented that quantifies prepulse reduction in an intense, ultrashort pulse on reflection from a high-density plasma created from a SiO2 target at Brewster's angle. The contrast between the intense ultrashort pulse and prepulse energy was improved by a factor of >625. Pulse-width reduction, spectral broadening, and spatial filtering are also observed in the reflected pulse. RP GOLD, DM (reprint author), LAWRENCE LIVERMORE NATL LAB,L-251,7000 EAST AVE,LIVERMORE,CA 94550, USA. NR 17 TC 35 Z9 37 U1 1 U2 6 PU OPTICAL SOC AMER PI WASHINGTON PA 2010 MASSACHUSETTS AVE NW, WASHINGTON, DC 20036 SN 0146-9592 J9 OPT LETT JI Opt. Lett. PD DEC 1 PY 1994 VL 19 IS 23 BP 2006 EP 2008 DI 10.1364/OL.19.002006 PG 3 WC Optics SC Optics GA PU974 UT WOS:A1994PU97400030 PM 19855724 ER PT J AU HERWIG, LO WITT, CE TAYLOR, RW AF HERWIG, LO WITT, CE TAYLOR, RW TI UNITED-STATES PHOTOVOLTAIC PROGRAM INITIATIVES - PVMAT AND PV-BONUS SO OPTOELECTRONICS-DEVICES AND TECHNOLOGIES LA English DT Article DE PHOTOVOLTAIC TECHNOLOGY; PHOTOVOLTAICS (PV); SEMICONDUCTORS; SOLAR ELECTRIC; PV MANUFACTURING COST REDUCTION; PV MARKET DEVELOPMENT AB A review is given of two important recent initiatives in the United States photovoltaic program-the Photovoltaic Manufacturing Technology (PVMaT) Project and the Building Opportunities in the U.S. for Photovoltaics (PV: BONUS) Project. The PVMaT project has been established to improve manufacturing processes and reduce manufacturing costs. The PV: BONUS Project is being directed to developing and testing new photovoltaic building products and systems. These two projects along with others to be briefly mentioned are part of a substantive adjustment in the balance of the United States photovoltaic energy technology program from a predominant research and development orientation in the mid-1970's through the late 1980's to a present major cooperative involvement with U.S. industry in manufacturing and market development. C1 NATL RENEWABLE ENERGY LAB,GOLDEN,CO 80401. RP HERWIG, LO (reprint author), US DOE,1000 INDEPENDENCE AVE SW,WASHINGTON,DC 20585, USA. NR 6 TC 0 Z9 0 U1 0 U2 1 PU MITA PRESS PI TOKYO PA OCHANOMIZU CENTER BLDG 2-12 HONGO-3 BUNKYO-KU, TOKYO 113, JAPAN SN 0912-5434 J9 OPTOELECTRON-DEVICES JI Optoelectron.-Devices Technol. PD DEC PY 1994 VL 9 IS 4 BP 459 EP 472 PG 14 WC Engineering, Electrical & Electronic; Optics SC Engineering; Optics GA QD449 UT WOS:A1994QD44900004 ER PT J AU SHEN, CC CHANG, PT EMERY, K AF SHEN, CC CHANG, PT EMERY, K TI 2-TERMINAL MONOLITHIC INP/INGAASP TANDEM SOLAR-CELLS WITH TUNNELING INTERCELL OHMIC CONNECTIONS SO OPTOELECTRONICS-DEVICES AND TECHNOLOGIES LA English DT Article DE TANDEM SOLAR CELLS; INP BASED SOLAR CELLS; INGAASP TUNNEL JUNCTIONS; INGAASP SOLAR CELL; LIQUID PHASE EPITAXY ID FABRICATION; DAMAGE AB In order to explore the potential of InP based material for multijunction tandem solar cell applications, a two-terminal monolithic InP/InGaAsP tandem solar cell was prepared by two-step liquid phase epitaxial (LPE) growth and their photovoltaic properties were characterized. The series-connected tandem solar cell consists of a 1.35 eV p/n homojunction InP top subcell and a lattice matched 0.95 eV p/n homojunction InGaAsP bottom subcell. A patterned 0.95 eV n(+)/p(+) InGaAsP tunnel diode was employed as intercell ohmic connections (IOCs). The open-circuit voltage, short-circuit current and fill factor exhibited by the most efficient InP/InGaAsP tandem solar cell under one sun, AM1.5 global illuminations were 1.363 V, 13.85 mA/cm(2) and 0.786, respectively; with a total-area conversion efficiency of 14.8%. Further improvements in conversion efficiencies may be obtained by depositing a wide bandgap GaInP top subcell to the existing InP/InGaAsP tandem structure to form a two terminal monolithic GaInP/InP/InGaAsP tandem solar cell. Some of the technical issues concerning three-junction InP-based tandem solar cells are discussed. C1 NATL RENEWABLE ENERGY LAB,GOLDEN,CO 80401. RP SHEN, CC (reprint author), ARIZONA STATE UNIV,CTR SOLID STATE ELECTR RES,TEMPE,AZ 85287, USA. NR 14 TC 0 Z9 0 U1 0 U2 2 PU MITA PRESS PI TOKYO PA OCHANOMIZU CENTER BLDG 2-12 HONGO-3 BUNKYO-KU, TOKYO 113, JAPAN SN 0912-5434 J9 OPTOELECTRON-DEVICES JI Optoelectron.-Devices Technol. PD DEC PY 1994 VL 9 IS 4 BP 551 EP 560 PG 10 WC Engineering, Electrical & Electronic; Optics SC Engineering; Optics GA QD449 UT WOS:A1994QD44900011 ER PT J AU STONE, JL AF STONE, JL TI PV IN THE DEVELOPING-WORLD SO OPTOELECTRONICS-DEVICES AND TECHNOLOGIES LA English DT Editorial Material RP STONE, JL (reprint author), NATL RENEWABLE ENERGY LAB,1617 COLE BLVD,GOLDEN,CO 80401, USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU MITA PRESS PI TOKYO PA OCHANOMIZU CENTER BLDG 2-12 HONGO-3 BUNKYO-KU, TOKYO 113, JAPAN SN 0912-5434 J9 OPTOELECTRON-DEVICES JI Optoelectron.-Devices Technol. PD DEC PY 1994 VL 9 IS 4 BP 607 EP 608 PG 2 WC Engineering, Electrical & Electronic; Optics SC Engineering; Optics GA QD449 UT WOS:A1994QD44900018 ER PT J AU EGLINTON, TI IRVINE, JE VAIRAVAMURTHY, A ZHOU, WQ MANOWITZ, B AF EGLINTON, TI IRVINE, JE VAIRAVAMURTHY, A ZHOU, WQ MANOWITZ, B TI FORMATION AND DIAGENESIS OF MACROMOLECULAR ORGANIC SULFUR IN PERU MARGIN SEDIMENTS SO ORGANIC GEOCHEMISTRY LA English DT Article; Proceedings Paper CT 16th International Meeting on Organic Geochemistry - Advances in Organic Geochemistry 1993 CY SEP 20-24, 1993 CL STAVANGER, NORWAY SP European Assoc Organic Geochemists DE PERU MARGIN; MONTEREY FM; ORGANIC SULFUR; MACROMOLECULES; KEROGEN; X-RAY ABSORPTION SPECTROSCOPY; ANALYTICAL PYROLYSIS; ORGANIC CARBON PRESERVATION ID PYROLYSIS-GAS CHROMATOGRAPHY; CARBON-RICH SEDIMENTS; RAY ABSORPTION-SPECTROSCOPY; UPWELLING REGION SEDIMENTS; HIGH-MOLECULAR-WEIGHT; FLASH PYROLYSIS; PETROLEUM ASPHALTENES; STRUCTURAL SIMILARITIES; HYDROUS PYROLYSIS; MODEL COMPOUNDS AB The geochemistry of organic sulfur in a suite of samples covering the upper 100 m of sediment from the Peruvian margin has been characterized by elemental analysis, X-ray absorption (XANES) spectroscopy and analytical pyrolysis. These data are compared with those obtained from a thermally immature, but consolidated, sulfur-rich sediment (Miocene Monterey Fm, CA). Results indicate that sulfur incorporation into organic matter takes place primarily within the upper few meters of sediment, but sulfur ''in-growth'' continues at greater depths. The major initial products are organic sulfides, with subordinate amounts of thiophenes. Sulfonic acids also comprise a significant portion of the organically-bound sulfur in the shallowest sediments. Analysis of chemically defined organic matter sub-fractions isolated from a surficial (< 1 m) sample revealed no consistent relationship between molecular size and the proportion of sulfide bridges. In contrast, a strong correlation between these two parameters was observed for the Monterey Fm sample, implying that the degree of sulfur cross-linking may, in part, control molecular size and/or solubility. These findings have implications concerning the proposed role of sulfur in organic matter preservation through quenching selected labile biochemicals. The lack of any link between the formation of intermolecular sulfide bridges and the principal zone for remineralization of organic matter in sediments (i.e. the upper 1 m) suggests this process has only minor influence on the efficiency of organic carbon burial. Thus, if sulfur plays a role in the preservation of labile molecules, a different process must be responsible in Peru sediments. The relative proportion of kerogen-derived thiophenic pyrolysis products increases significantly over the 100 m depth interval and in the deepest samples approaches those of the Monterey sample. The distribution of thiophenic pyrolysis products in the deepest Peru sample also closely resembles that of the Monterey kerogen suggesting the presence of similar sulfur-bound (lipid) building blocks. Subtle differences include a higher proportion of products held to derive from steroid carbon skeletons in the Peru kerogens and a more significant contribution of products originating from isoprenoid carbon skeletons in the Monterey sample. The close similarity in organic sulfur composition for these samples lends support for the premise that the Peru margin is a modern analogue of the Monterey Fm. C1 BROOKHAVEN NATL LAB, DEPT APPL SCI, UPTON, NY 11973 USA. RP EGLINTON, TI (reprint author), WOODS HOLE OCEANOG INST, DEPT MARINE CHEM & GEOCHEM, WOODS HOLE, MA 02543 USA. NR 62 TC 72 Z9 73 U1 0 U2 5 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLAND SN 0146-6380 J9 ORG GEOCHEM JI Org. Geochem. PD DEC PY 1994 VL 22 IS 3-5 BP 781 EP 799 DI 10.1016/0146-6380(94)90139-2 PG 19 WC Geochemistry & Geophysics SC Geochemistry & Geophysics GA QG384 UT WOS:A1994QG38400030 ER PT J AU FAULON, JL CARLSON, GA HATCHER, PG AF FAULON, JL CARLSON, GA HATCHER, PG TI A 3-DIMENSIONAL MODEL FOR LIGNOCELLULOSE FROM GYMNOSPERMOUS WOOD SO ORGANIC GEOCHEMISTRY LA English DT Article DE LIGNIN; LIGNOCELLULOSE; MOLECULAR MECHANICS; DYNAMICS SIMULATIONS ID VOLATILE BITUMINOUS COAL; COMPUTER-SIMULATION; CHEMICAL-STRUCTURE; COALIFIED WOOD; LIGNIN; VITRINITE AB The three-dimensional characteristics of lignocellulose complexes are examined by the use of molecular mechanics and dynamics. The model created is composed of cellulose, hemicellulose, and lignin as would be present in gymnospermous wood tracheids. Molecular mechanics and dynamics show that the hemicellulose is hydrogen bonded and oriented parallel to the cellulose microfibrils. Energy minimization of lignin unite linked by the major lignin type bond reveals a helical structure. On the basis of these findings we propose a model for three-dimensional organization of lignocellulose. C1 PENN STATE UNIV,FUEL SCI PROGRAM,UNIVERSITY PK,PA 16802. RP FAULON, JL (reprint author), SANDIA NATL LABS,DEPT FUEL SCI,POB 5800,ALBUQUERQUE,NM 87185, USA. NR 36 TC 35 Z9 36 U1 2 U2 13 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD, ENGLAND OX5 1GB SN 0146-6380 J9 ORG GEOCHEM JI Org. Geochem. PD DEC PY 1994 VL 21 IS 12 BP 1169 EP 1179 DI 10.1016/0146-6380(94)90161-9 PG 11 WC Geochemistry & Geophysics SC Geochemistry & Geophysics GA PL576 UT WOS:A1994PL57600002 ER PT J AU BERNATIS, PR MIEDANER, A HALTIWANGER, RC DUBOIS, DL AF BERNATIS, PR MIEDANER, A HALTIWANGER, RC DUBOIS, DL TI EXCLUSION OF 6-COORDINATE INTERMEDIATES IN THE ELECTROCHEMICAL REDUCTION OF CO2 CATALYZED BY [PD(TRIPHOSPHINE)(CH3CN)](BF4)(2) COMPLEXES SO ORGANOMETALLICS LA English DT Article ID CARBON-DIOXIDE CHEMISTRY; ELECTROCATALYTIC REDUCTION; CATIONS; NICKEL; SERIES; NI AB [Pd(triphosphine)(CH3CN)](BF4)(2) complexes have been prepared with mesityl or tri-methoxybenzene substituents on the central phosphorus atom of the triphosphine ligand. An X-ray diffraction study of [Pd(MesetpE)(CH3CN)](BF4)(2) (where MesetpE is bis((diethylphosphino)ethyl)mesitylphosphine) has been completed. [Pd(MesetpE)(CH3CN)](BF4)(2) crystallizes in the space group P $($) over bar$$ 1 with a 10.370(2) Angstrom, b = 11.009(2) Angstrom, c = 14.483(2) Angstrom, alpha = 103.203(13)degrees, beta = 92.748(16)degrees, gamma = 92.556(15)degrees, V = 1605.2(5) Angstrom(3), and Z = 2. The structure was refined to R = 0.0659 and R(w) = 0.0771 for 4467 independent reflections with F > 4 sigma(F). The cation has a square-planar structure with one methyl group of the central mesityl substituent blocking one potential coordination site. Kinetic studies of this complex in dimethylformamide indicate that the rate-determining step is the reaction of the [Pd(MesetpE)(DMF)](+) cation with CO2. Comparison of the rate constants for this and other mesityl- substituted complexes with those of other [Pd(triphosphine)(CH3CN)](BF4)(2) complexes suggests that all proceed through a five-coordinate transition state. RP BERNATIS, PR (reprint author), NATL RENEWABLE ENERGY LAB,GOLDEN,CO 80401, USA. NR 44 TC 35 Z9 35 U1 0 U2 11 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 SN 0276-7333 J9 ORGANOMETALLICS JI Organometallics PD DEC PY 1994 VL 13 IS 12 BP 4835 EP 4843 DI 10.1021/om00024a029 PG 9 WC Chemistry, Inorganic & Nuclear; Chemistry, Organic SC Chemistry GA PW700 UT WOS:A1994PW70000029 ER PT J AU STEFFEY, BD MIEDANER, A MACIEJEWSKIFARMER, ML BERNATIS, PR HERRING, AM ALLURED, VS CARPEROS, V DUBOIS, DL AF STEFFEY, BD MIEDANER, A MACIEJEWSKIFARMER, ML BERNATIS, PR HERRING, AM ALLURED, VS CARPEROS, V DUBOIS, DL TI SYNTHESIS AND CHARACTERIZATION OF PALLADIUM COMPLEXES CONTAINING TRIDENTATE LIGANDS WITH PXP (X=C, N, O, S, AS) DONOR SETS AND THEIR EVALUATION AS ELECTROCHEMICAL CO2 REDUCTION CATALYSTS SO ORGANOMETALLICS LA English DT Article ID HOMOGENEOUS ELECTRON-TRANSFER; CARBON-DIOXIDE; NICKEL(II) COMPLEXES; REDOX CATALYSIS; ACTIVATION; COBALT(I); CRYSTAL; THERMODYNAMICS; STABILIZATION; COMPETITION AB Square-planar palladium complexes containing tridentate ligands with PXP (X = C, N, O, S, and As) donor sets have been prepared. For [Pd(POP-R)(CH3CN)(2)](BF4)(2) complexes (where POP-R is bis((diethylphosphino)ethyl) ether, bis((diphenylphosphino)ethyl) ether, or bis((dicyclohexylphosphino)ethyl)ether), the POP-R ligands function as bidentate ligands. For all other complexes, the PXP ligands function as tridentate ligands. The complex [Pd(PCP)(PEt(3))](BF4) (where PCP is 2,6-bis(( diphenylphosphino)methyl)phenyl) crystalliz es in the triclinic space group P $($) over bar$$ 1 with a = 10.276(2) Angstrom, b = 10.978(2) Angstrom, c = 18.807(3) Angstrom, alpha 84.820(10)degrees, beta = 76.910(10)degrees, gamma = 63.870(10)degrees, V = 1855.2(6) Angstrom(3), and Z = 2. The structure was refined to R = 0.0335 and R(w) = 0.0442 for 7570 independent reflections with F > 4.0 sigma(F). [Pd(PNP)(PEt(3))](BF4)(2) (where PNP is 2,6-bis((diphenylphosphino)methyl)pyridine crystallizes in the monoclinic space group C2/c with a = 13.246(2) Angstrom, b = 14.299(2) Angstrom, c = 20.847(4) $ beta = 100.96(2)degrees, V = 3876.5(11) Angstrom(3), and Z = 4. The structure was refined to R = 0.0436;and Rw = 0.0556 for 3106 independent reflections with F > 6.0 sigma(F). Both cations adopt square-planar structures with small C-Pd-P (79.0 and 79.1 degrees) and N-Pd-P (80.3 degrees) chelate angles. The Pd-P bond distances of the triethylphosphine ligands differ by 0.079 a for these two complexes. The acetonitrile complexes undergo one-electron reductions, while the corresponding triethylphosphine complexes undergo two-electron reductions. [Pd(PCP)-(CH3CN)](BF4) exhibits significant catalytic currents in the presence of acid and CO2. The dependence of the catalytic current on CO2 and acid concentrations is consistent with the formation of a hydroxycarbonyl intermediate which decomposes in the presence of acid to form Hz as the catalytic product. Structure-activity relationships for CO2 reduction for this class of compounds are discussed. RP STEFFEY, BD (reprint author), NATL RENEWABLE ENERGY LAB,GOLDEN,CO 80401, USA. RI Herring, Andy/E-7088-2010; OI Herring, Andrew/0000-0001-7318-5999 NR 55 TC 75 Z9 75 U1 1 U2 10 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 SN 0276-7333 J9 ORGANOMETALLICS JI Organometallics PD DEC PY 1994 VL 13 IS 12 BP 4844 EP 4855 DI 10.1021/om00024a030 PG 12 WC Chemistry, Inorganic & Nuclear; Chemistry, Organic SC Chemistry GA PW700 UT WOS:A1994PW70000030 ER PT J AU CHEN, MJ RATHKE, JW AF CHEN, MJ RATHKE, JW TI REVERSIBLE HYDROCARBON ACTIVATION BY RHODIUM PHTHALOCYANINE DIMER [(R(8)PC)RH](2) (R(8)PC(2-)=DIANION OF 1,4,8,11,15,18,22,25-OCTA-N-PENTYLPHTHALOCYANINE) SO ORGANOMETALLICS LA English DT Article ID C-H BONDS; CARBON HYDROGEN-BONDS; OXIDATIVE ADDITION; COMPLEXES; METAL; IRIDIUM(I); INSERTION; ALKANES AB We have synthesized four rhodium-phthalocyanine complexes: (R(8)Pc)(C6H5CN)ClRh, [(R(8)-Pc)(MeOH)(2)Rh]Cl, [(R(8)Pc)Rh](2) (1), and (R(8)PcH)RhRh(R(8)Pc)H (2). In this notation R(8)Pc(2-) is the dianion of 1,4,8,11,15,18,22,25-octa-n-pentylphthalocyanine. The Rh-Rh bonded dimer 1 reacts with H-2 to give 2, and it activates the C-H bonds of toluene and the R(8)Pc(2-) ligand at temperatures of 150 degrees C. It also catalyzes the H-D exchange between the R(8)Pc(2-) ligand and D2O and between the ligand and toluene-d(8). Although all of the H's of the R(8)Pc(2-) ligand are activated, only the benzylic H's of toluene are activated. A radical mechanism, initiated by homolysis of 1, is proposed for these reactions. RP CHEN, MJ (reprint author), ARGONNE NATL LAB,DIV CHEM TECHNOL,9700 S CASS AVE,ARGONNE,IL 60439, USA. NR 22 TC 8 Z9 8 U1 2 U2 11 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 SN 0276-7333 J9 ORGANOMETALLICS JI Organometallics PD DEC PY 1994 VL 13 IS 12 BP 4875 EP 4880 DI 10.1021/om00024a033 PG 6 WC Chemistry, Inorganic & Nuclear; Chemistry, Organic SC Chemistry GA PW700 UT WOS:A1994PW70000033 ER PT J AU WHITE, CJ ANGELICI, RJ AF WHITE, CJ ANGELICI, RJ TI SYNTHESIS, STRUCTURE, AND REACTIVITY OF THIENYLCARBENE, BENZOTHIENYLCARBENE, AND SELENYLCARBENE COMPLEXES OF RHENIUM - A NEW MECHANISM FOR H/D EXCHANGE DURING HYDRODESULFURIZATION SO ORGANOMETALLICS LA English DT Article ID DEUTERIUM-EXCHANGE; METAL-COMPLEXES; CONTAINING LIGANDS; THIOPHENE; CATALYSTS; ADSORPTION; MODEL; COORDINATION; CHEMISTRY; CP(CO)(PPH3)RU(ETA-1(S)-TH)+ AB A series of eta(1)(E)-coordinated (E = S or Se) thiophene, benzo[b]thiophene and selenophene complexes [Cp(NO)(PPh(3))Re(yl(E)-L)](+), Cp = C5H5, L = thiophene (T), 2-methylthiophene (2-MeT), 2,5-dimethylthiophene (2,5-Me(2)T), benzo[b]thiophene (BT), 3-methylbenzo[b]-thiophene (3-MeBT), selenophene (Sell, 2-methylselenophene (2-MeSel), and 2,5-dimethylselenophene (2,5-Me(2)Sel) are prepared by the reaction of [Cp(NO)(PPh(3))Re(ClC6H5)](+) with the appropriate ligand. The T, 2-MeT, BT, 3-MeBT, Sel, 2-MeSel complexes are deprotonated at C(2) by strong, non-nucleophilic bases to give the neutral Cp(NO)(PPh(3))Re(2-L-yl) complexes, where 2-L-yl = 2-thienyl (2-Tyl), 2-(5-methylthienyl) (2-(5-MeTyl)), 2-benzothienyl (2-BTyl), 2-(3-methylbenzothienyl) (2-(3-MeBTyl)), 2-selenyl (2-Selyl), and 2-(5-methylselenyl) (2-(5-MeSelyl)). The pK(a), of the base required to effect this deprotonation increases with the L ligand in the complex in the following order: Sel < T < BT. The 2-Tyl, 2-BTyl and 2-Selyl complexes react with either HBF4.Et(2)O or HO3SCF3 at -42 degrees C to give the corresponding carbene complexes [Cp(NO)(PPh(3))Re(2-L-ylcarbene)](+) re suiting from proto nation at C(3). The molecular structure of [Cp(NO)(PPh(3))Re(2-BTylcarbene)]O3SCF3, as determined by an X-ray diffraction study, exhibits a Re=C bond distance of 1.992(7) Angstrom. The carbene complexes do not react with nucleophiles; however, those nucleophiles that are sufficiently basic deprotonate C(3) to give back the L-yl compound. The pK(a) values of bases that are strong enough to cause deprotonation increase with the L-ylcarbene ligand in the order: Selylcarbene similar to Tylcarbene similar to BTylcarbene. The carbene complexes [Cp(NO)(PPh(3))Re(2-(5-MeTylcarbene)](+) and [Cp(NO)(PPh(3))Re(2-(5-MeSelylcarbene)](+) are unstable and rearrange to their more stable isomers [Cp(NO)(PPh(3))Re(eta(1)(S)-2-MeT)](+) and [Cp(NO)(PPh(3))Re(eta(1)(Se)-2-MeSel)]+. A new mechanism for H/D exchange of thiophene on hydrodesulfurization catalysts is proposed based on deuterium labeling studies of these thiophene complexes. C1 IOWA STATE UNIV SCI & TECHNOL,DEPT CHEM,AMES,IA 50011. IOWA STATE UNIV SCI & TECHNOL,AMES LAB,AMES,IA 50011. NR 45 TC 18 Z9 18 U1 0 U2 0 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 SN 0276-7333 J9 ORGANOMETALLICS JI Organometallics PD DEC PY 1994 VL 13 IS 12 BP 5132 EP 5140 DI 10.1021/om00024a064 PG 9 WC Chemistry, Inorganic & Nuclear; Chemistry, Organic SC Chemistry GA PW700 UT WOS:A1994PW70000064 ER PT J AU ZHU, YM ZUO, JM MOODENBAUGH, AR SUENAGA, M AF ZHU, YM ZUO, JM MOODENBAUGH, AR SUENAGA, M TI GRAIN-BOUNDARY CONSTRAINT AND OXYGEN DEFICIENCY IN YBA2CU3O7-DELTA - APPLICATION OF THE COINCIDENCE SITE LATTICE MODEL TO A NONCUBIC SYSTEM SO PHILOSOPHICAL MAGAZINE A-PHYSICS OF CONDENSED MATTER STRUCTURE DEFECTS AND MECHANICAL PROPERTIES LA English DT Article ID HIGH-TC SUPERCONDUCTORS; CLOSE-PACKED METALS; SPECTROSCOPY; BEHAVIOR; CRYSTALS; HOLES; EDGE AB Local lattice parameters and oxygen (hole) densities in the vicinity of large-angle grain boundaries in bulk YBa2Cu3O7-delta were measured simultaneously using convergent-beam electron diffraction and electron-energy-loss spectroscopy with a less than 20 angstrom field emission probe respectively. The oxygen (hole) contents were quantified by Gaussian fitting to the observed oxygen K-edge absorption spectra and comparing them with results for a set of standard samples with different oxygen contents. The local lattice parameters were determined by matching the simulated high-order Laue zone patterns with experimental patterns by a least-squares algorithm. We found that large-angle grain boundaries in YBa2Cu3O7-delta often exhibit volume expansion. The increase of the c-lattice parameter near the boundary core can be attributed to lattice distortion and/or to an oxygen deficiency. The lattice distortion extends less than 20 angstrom, while the deficiency can extend more than 100 angstrom. Comparison of the c/a ratio of the lattice parameters in the boundary regions with those in the interior of the adjacent grains suggests that, to reduce boundary lattice mismatch or to form a coincidence boundary in YBa2Cu3O7-delta, the required grain-boundary constraint can be realized by adjusting the oxygen content at the boundary. Our observations convincingly demonstrate the validity of the constrained coincidence site lattice model for studying grain boundaries in non-cubic YBa2Cu3O7-delta. C1 ARIZONA STATE UNIV,DEPT PHYS,TEMPE,AZ 85287. RP ZHU, YM (reprint author), BROOKHAVEN NATL LAB,DIV MAT SCI,UPTON,NY 11973, USA. OI Moodenbaugh, Arnold/0000-0002-3415-6762 NR 36 TC 37 Z9 38 U1 3 U2 8 PU TAYLOR & FRANCIS LTD PI LONDON PA ONE GUNDPOWDER SQUARE, LONDON, ENGLAND EC4A 3DE SN 0141-8610 J9 PHILOS MAG A JI Philos. Mag. A-Phys. Condens. Matter Struct. Defect Mech. Prop. PD DEC PY 1994 VL 70 IS 6 BP 969 EP 984 PG 16 WC Materials Science, Multidisciplinary; Metallurgy & Metallurgical Engineering; Physics, Applied; Physics, Condensed Matter SC Materials Science; Metallurgy & Metallurgical Engineering; Physics GA PW421 UT WOS:A1994PW42100004 ER PT J AU ZHANG, W SCHNEIBEL, JH HSUEH, CH AF ZHANG, W SCHNEIBEL, JH HSUEH, CH TI SINTERING OF REGULAR 2-DIMENSIONAL ARRAYS OF PARTICLES BY SURFACE AND GRAIN-BOUNDARY DIFFUSION SO PHILOSOPHICAL MAGAZINE A-PHYSICS OF CONDENSED MATTER STRUCTURE DEFECTS AND MECHANICAL PROPERTIES LA English DT Article AB The times required for sintering of regular arrangements of circular (cylindrical) particles by surface and grain boundary diffusion have been evaluated using a precise two-dimensional numerical model. The influence of the dihedral angle and the grain boundary-to-surface diffusivity ratio have been examined. The sintering kinetics show the typical three stages, namely, fast sintering, followed by a stage of slow sintering and, finally, fast sintering near the point of final pore collapse. Following W. W. Mullins (1993, Scripta Metall. Mater. 29, 491), a simplified analysis assuming quasi-equilibrium pore shapes is carried out and discussed in terms of the full numerical model. By modelling different regularly packed particle arrays, the influence of initial density on the sintering kinetics is also evaluated. Not surprisingly, the densification time increases dramatically as the initial packing density decreases. C1 OAK RIDGE NATL LAB,DIV MET & CERAM,OAK RIDGE,TN 37831. RI Hsueh, Chun-Hway/G-1345-2011 NR 12 TC 11 Z9 11 U1 0 U2 4 PU TAYLOR & FRANCIS LTD PI LONDON PA ONE GUNDPOWDER SQUARE, LONDON, ENGLAND EC4A 3DE SN 0141-8610 J9 PHILOS MAG A JI Philos. Mag. A-Phys. Condens. Matter Struct. Defect Mech. Prop. PD DEC PY 1994 VL 70 IS 6 BP 1107 EP 1118 PG 12 WC Materials Science, Multidisciplinary; Metallurgy & Metallurgical Engineering; Physics, Applied; Physics, Condensed Matter SC Materials Science; Metallurgy & Metallurgical Engineering; Physics GA PW421 UT WOS:A1994PW42100013 ER PT J AU BUTT, DP WALTER, KC NASTASI, M CAMPUZANO, AL MARTIN, PS WOOD, BP REJ, DJ MILLER, GG AF BUTT, DP WALTER, KC NASTASI, M CAMPUZANO, AL MARTIN, PS WOOD, BP REJ, DJ MILLER, GG TI CORROSION OF DIAMOND-LIKE CARBON-COATED NICKEL IN 0.25-M SODIUM-CHLORIDE SO PHILOSOPHICAL MAGAZINE LETTERS LA English DT Article AB Diamond-like carbon (DLC) was deposited on to high-purity nickel using an acetylene plasma. The corrosion resistance of coated and uncoated nickel was electrochemically measured in 0.25M NaCl at 22-degrees-C. This work presents the first report of the deposition of DLC on to nickel and the first potentiodynamic electrochemical testing of DLC. The DLC-coated nickel had a corrosion rate more than two orders of magnitude less and a corrosion potential 0.22 V greater than those of the uncoated nickel. C1 LOS ALAMOS NATL LAB,DIV PHYS,LOS ALAMOS,NM 87545. LOS ALAMOS NATL LAB,DIV CHEM SCI & TECHNOL,LOS ALAMOS,NM 87545. RP BUTT, DP (reprint author), LOS ALAMOS NATL LAB,DIV MAT SCI & TECHNOL,LOS ALAMOS,NM 87545, USA. RI Butt, Darryl/B-7480-2008 OI Butt, Darryl/0000-0003-4501-8864 NR 6 TC 9 Z9 9 U1 0 U2 1 PU TAYLOR & FRANCIS LTD PI LONDON PA ONE GUNDPOWDER SQUARE, LONDON, ENGLAND EC4A 3DE SN 0950-0839 J9 PHIL MAG LETT JI Philos. Mag. Lett. PD DEC PY 1994 VL 70 IS 6 BP 385 EP 387 DI 10.1080/09500839408240505 PG 3 WC Materials Science, Multidisciplinary; Metallurgy & Metallurgical Engineering; Physics, Applied; Physics, Condensed Matter SC Materials Science; Metallurgy & Metallurgical Engineering; Physics GA PW418 UT WOS:A1994PW41800005 ER PT J AU OROSKAR, A OLACK, G PEAK, MJ GASPARRO, FP AF OROSKAR, A OLACK, G PEAK, MJ GASPARRO, FP TI 4'-AMINOMETHYL-4,5',8-TRIMETHYLPSORALEN PHOTOCHEMISTRY - THE EFFECT OF CONCENTRATION AND UVA FLUENCE ON PHOTOADDUCT FORMATION IN POLY(DA-DT) AND CALF THYMUS DNA SO PHOTOCHEMISTRY AND PHOTOBIOLOGY LA English DT Article ID CROSS-LINKS; 8-METHOXYPSORALEN MONOADDUCTS; PSORALEN; LIGHT; PHOTOCHEMOTHERAPY; VIRUS; HELIX AB The photochemistry of 4'-aminomethyl-4,5',8-trimethylpsoralen (AMT) with poly(dA-dT) and calf thymus DNA was studied. The extent of photoadduct formation and the distribution of photoadducts (3,4- and 4',5'-monoadducts and crosslinks) were determined by liquid scintillation analysis and HPLC, respectively. The adducts were characterized on the basis of their UV absorption spectra and mass spectral analysis. The high DNA binding constant for AMT (1.5 x 10(5) M(-1)) led to a high fraction of intercalated molecules, which contributed to the high level of AMT photoadduct formation, as many as 102 adducts per kilobase pair. In addition, there is a distinct difference in the adduct distribution compared to the previously studied 8-methoxypsoralen (8-MOP). Under the conditions employed for the photochemical studies, virtually all of the AMT molecules in solution are intercalated, occupying 25% of the base pair sites. Under similar conditions, 8-MOP molecules occupied 10 times fewer sites. Thus, for AMT, DNA base pair sites other than 5'TA, the well-characterized strong binding for psoralens in general, are an additional target for photomodification, which results in the formation of a higher percentage of monoadducts. The proportion of photoadducts formed was virtually independent of AMT concentration and UVA (320-400 nm radiation) fluence. C1 YALE UNIV,DEPT DERMATOL,PHOTOBIOL LAB,NEW HAVEN,CT 06510. ARGONNE NATL LAB,CTR MECH BIOL & BIOTECHNOL,ARGONNE,IL 60439. NR 25 TC 10 Z9 10 U1 0 U2 2 PU AMER SOC PHOTOBIOLOGY PI AUGUSTA PA BIOTECH PARK, 1021 15TH ST, SUITE 9, AUGUSTA, GA 30901-3158 SN 0031-8655 J9 PHOTOCHEM PHOTOBIOL JI Photochem. Photobiol. PD DEC PY 1994 VL 60 IS 6 BP 567 EP 573 DI 10.1111/j.1751-1097.1994.tb05149.x PG 7 WC Biochemistry & Molecular Biology; Biophysics SC Biochemistry & Molecular Biology; Biophysics GA PY874 UT WOS:A1994PY87400006 PM 7870761 ER PT J AU RODDAY, SM SCHULZ, R MCINTOSH, L BIGGINS, J AF RODDAY, SM SCHULZ, R MCINTOSH, L BIGGINS, J TI STRUCTURE-FUNCTION STUDIES ON THE INTERACTION OF PSAC WITH THE PHOTOSYSTEM-1 HETERODIMER - THE SITE-DIRECTED CHANGE R561E IN PSAB DESTABILIZES THE SUBUNIT INTERACTION IN SYNECHOCYSTIS SP PCC-6803 SO PHOTOSYNTHESIS RESEARCH LA English DT Article DE ELECTRON TRANSFER; IRON-SULFUR CENTERS; FLASH ABSORPTION SPECTROPHOTOMETRY; SITE-DIRECTED MUTAGENESIS; SUBUNIT INTERACTIONS ID I REACTION CENTER; CORE PROTEIN; P700 CHLOROPHYLL; FX; RECONSTITUTION; SEQUENCE; COMPLEX; RESOLUTION; BINDING; SPECTRA AB The interaction of PsaC with the core heterodimer of Photosystem 1 was studied in wild type Synechocystis sp. PCC 6803 and the site-directed mutant R561E of PsaB. The mutant reaction center was much less stable in urea and the functional reconstitution of the mutant core using PsaC was impaired. However, the extent of reconstitution increased in the presence of divalent cations whereas that of the wild type was inhibited. We conclude that the reaction center in the mutant is unstable, most likely due to the introduction of an unfavorable electrostatic interaction between surface-exposed residues on PsaC and the binding site for the subunit on the core heterodimer in support of the model proposed previously (Rodday et al. (1993) Photosynth Res 36: 1-9). C1 BROWN UNIV,BIOCHEM SECT,PROVIDENCE,RI 02912. MICHIGAN STATE UNIV,US DOE,PLANT RES LAB,E LANSING,MI 48824. MICHIGAN STATE UNIV,DEPT BIOCHEM,E LANSING,MI 48824. NR 24 TC 13 Z9 13 U1 0 U2 1 PU KLUWER ACADEMIC PUBL PI DORDRECHT PA SPUIBOULEVARD 50, PO BOX 17, 3300 AA DORDRECHT, NETHERLANDS SN 0166-8595 J9 PHOTOSYNTH RES JI Photosynth. Res. PD DEC PY 1994 VL 42 IS 3 BP 185 EP 190 DI 10.1007/BF00018261 PG 6 WC Plant Sciences SC Plant Sciences GA QJ056 UT WOS:A1994QJ05600004 PM 24306560 ER PT J AU BLATTER, G IVLEV, B KAGAN, Y VINOKUR, V AF BLATTER, G IVLEV, B KAGAN, Y VINOKUR, V TI QUANTUM-STATISTICAL AND DYNAMICAL EFFECTS IN VORTEX SYSTEMS SO PHYSICA C LA English DT Article ID HIGH-TC SUPERCONDUCTORS; VORTICES; LATTICE; CREEP AB We review some recent developments in the quantum statistical mechanics and in the quantum dynamics of the vortex system in high temperature- and in conventional high-resistivity thin-film superconductors. C1 LD LANDAU THEORET PHYS INST,MOSCOW 117940,RUSSIA. IV KURCHATOV ATOM ENERGY INST,MOSCOW 123182,RUSSIA. ARGONNE NATL LAB,ARGONNE,IL 60439. RP BLATTER, G (reprint author), ETH HONGGERBERG,CH-8093 ZURICH,SWITZERLAND. NR 12 TC 2 Z9 2 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 DEC PY 1994 VL 235 BP 41 EP 44 DI 10.1016/0921-4534(94)91309-9 PN 1 PG 4 WC Physics, Applied SC Physics GA QA390 UT WOS:A1994QA39000015 ER PT J AU SCHLESINGER, Z COLLINS, RT ROTTER, LD HOLTZBERG, F FEILD, C WELP, U CRABTREE, GW LIU, JZ FANG, Y VANDERVOORT, KG FLESHLER, S AF SCHLESINGER, Z COLLINS, RT ROTTER, LD HOLTZBERG, F FEILD, C WELP, U CRABTREE, GW LIU, JZ FANG, Y VANDERVOORT, KG FLESHLER, S TI FUNDAMENTAL PROPERTIES OF CUPRATE SUPERCONDUCTORS AS PROBED BY INFRARED-SPECTROSCOPY SO PHYSICA C LA English DT Article ID YBA2CU3O7-DELTA THIN-FILM; SINGLE-DOMAIN YBA2CU3O7; HIGH-TC SUPERCONDUCTORS; ENERGY-GAP; OPTICAL CONDUCTIVITY; TEMPERATURE AB A brief, selective review shows the unconventional nature of the normal state, the loss of spectral weight and appearance of a 500 cm(-1) psuedo-gap in the low temperature infrared conductivity, and the evidence for pair formation above T-c in YBa2Cu3O7-x. C1 STCS,ARGONNE,IL 60439. ARGONNE NATL LAB,DIV MAT SCI,ARGONNE,IL 60439. RP SCHLESINGER, Z (reprint author), IBM CORP,THOMAS J WATSON RES CTR,YORKTOWN HTS,NY 10598, USA. RI Collins, Reuben/O-2545-2014 OI Collins, Reuben/0000-0001-7910-3819 NR 23 TC 14 Z9 14 U1 1 U2 1 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0921-4534 J9 PHYSICA C JI Physica C PD DEC PY 1994 VL 235 BP 49 EP 52 DI 10.1016/0921-4534(94)91311-0 PN 1 PG 4 WC Physics, Applied SC Physics GA QA390 UT WOS:A1994QA39000017 ER PT J AU BULAEVSKII, LN MALEY, MP CHO, JH AF BULAEVSKII, LN MALEY, MP CHO, JH TI FLUCTUATIONS OF VORTICES IN JOSEPHSON-COUPLED SUPERCONDUCTORS SO PHYSICA C LA English DT Article ID HIGH-TC SUPERCONDUCTORS; VORTEX LATTICE; II SUPERCONDUCTORS; REVERSIBLE MAGNETIZATION; LOW-TEMPERATURE; FIELD; LINES; MODEL AB The effect of thermal and quantum fluctuations of vortices on the reversible magnetization in the mixed state in highly anisotropic layered superconductors is discussed. For a magnetization, M, a change of slope in the M vs In B curves below 70 K, observed in Bi-2:2:1:2 and Tl-2:2:0:1 single crystals, is explained by quantum fluctuations of vortices within the Lawrence-Doniach model which incorporates viscous dynamics of pancake vortices. RP BULAEVSKII, LN (reprint author), LOS ALAMOS NATL LAB,POB 1663,LOS ALAMOS,NM 87545, USA. NR 24 TC 5 Z9 5 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 DEC PY 1994 VL 235 BP 87 EP 90 DI 10.1016/0921-4534(94)91321-8 PN 1 PG 4 WC Physics, Applied SC Physics GA QA390 UT WOS:A1994QA39000027 ER PT J AU CRAWFORD, MK HARLOW, RL MCCARRON, EM COX, DE HUANG, Q AF CRAWFORD, MK HARLOW, RL MCCARRON, EM COX, DE HUANG, Q TI EFFECTS OF STRUCTURAL PHASE-TRANSITIONS ON SUPERCONDUCTIVITY AND MAGNETISM IN SUBSTITUTED DERIVATIVES OF LA2CUO4 SO PHYSICA C LA English DT Article ID DOPED LA2CUO4; (LA AB Structural (neutron and x-ray diffraction) and magnetic (neutron diffraction and magnetic susceptibility) measurements of materials derived from La2CuO4 by isovalent and aliovalent substitution in the La3+ site have been performed. Such substitutions permit the tilts of the CuO6 octahedra (about the (110) and (110) axes of the undistorted 14/mmm structure), and the hole concentration in the Cu-O layers, to be independently varied. The results of these measurements, in combination with those from other research groups, demonstrate that all four tilt structures, HTT (high temperature tetragonal, 14/mmm), LTO1 (low temperature orthorhombic 1, Bmab), LTO2 (low temperature orthorhombic 2, Peen) and LTT (low temperature tetragonal, P4(2)/ncm), support bulk superconductivity, with T-c(HTT) > T-c(LTO1) > T-c(LTO2) > T-c(LTT) at the same hole concentration. Furthermore, there is a strong suppression of superconductivity when the doped carrier concentration is 1/8 hole per Cu2+ in the LTT and LTO2 phases of these materials. The reason for this T, suppression is not established. Finally, the magnetic structures adopted by the Cu2+ spins in the insulating phases, determined by neutron diffraction, are also influenced by the tilts of the octahedra. This may reflect a structural dependence of interlayer and intralayer magnetic anisotropies. C1 BROOKHAVEN NATL LAB,UPTON,NY 11973. NATL INST STAND & TECHNOL,GAITHERSBURG,MD 20899. RP CRAWFORD, MK (reprint author), DUPONT CO INC,WILMINGTON,DE 19880, USA. NR 17 TC 2 Z9 2 U1 2 U2 4 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0921-4534 J9 PHYSICA C JI Physica C PD DEC PY 1994 VL 235 BP 170 EP 173 DI 10.1016/0921-4534(94)91340-4 PN 1 PG 4 WC Physics, Applied SC Physics GA QA390 UT WOS:A1994QA39000046 ER PT J AU EMERY, VJ KIVELSON, SA AF EMERY, VJ KIVELSON, SA TI COLLECTIVE CHARGE-TRANSPORT IN HIGH-TEMPERATURE SUPERCONDUCTORS SO PHYSICA C LA English DT Article ID PHASE-SEPARATION; MODEL AB It is argued that the low energy physics of high temperature superconductors is governed by the scattering of mobile holes from local collective modes consisting of charge stripes and antiphase spin domains, as suggested by the competition between phase separation and the long range Coulomb force. Normal state charge transport is given by a paraconductivity associated with a non standard composite Frohlich-BCS pairing. In the ordered state, the order parameter is s-wave for tetragonal materials but, in other materials, there is a substantial mixing of d-wave via an unusual amplification of local or global asymmetry. C1 UNIV CALIF LOS ANGELES,DEPT PHYS,LOS ANGELES,CA 90024. RP EMERY, VJ (reprint author), BROOKHAVEN NATL LAB,DEPT PHYS,UPTON,NY 11973, USA. NR 32 TC 85 Z9 85 U1 1 U2 2 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0921-4534 J9 PHYSICA C JI Physica C PD DEC PY 1994 VL 235 BP 189 EP 192 DI 10.1016/0921-4534(94)91345-5 PN 1 PG 4 WC Physics, Applied SC Physics GA QA390 UT WOS:A1994QA39000051 ER PT J AU WELP, U GARDINER, T GUNTER, D FENDRICH, J CRABTREE, GW VLASKOVLASOV, VK NIKITENKO, VI AF WELP, U GARDINER, T GUNTER, D FENDRICH, J CRABTREE, GW VLASKOVLASOV, VK NIKITENKO, VI TI MAGNETOOPTICAL STUDY OF TWIN BOUNDARY PINNING IN YBA2CU3O7-DELTA SO PHYSICA C LA English DT Article ID FLUX DISTRIBUTION; SUPERCONDUCTORS; ANISOTROPY; SINGLE; LATTICE; FILMS AB Using a high-resolution magneto-optical technique we studied the flux penetration and pinning in YBa2Cu3O7-delta crystals in the presence of isolated twin boundaries. The most important factor determining the behavior of the twin boundaries is the direction of flux motion with respect to the boundary. Up to temperatures close to T-c twin boundaries are effective barriers for flux motion transverse to the boundaries. For flux motion parallel to the boundary the characteristic ''flame''-shaped flux patterns indicative of weak link behavior (i.e. low J(c)) of the boundary are observed. C1 SCI & TECHNOL CTR SUPERCONDUCT,ARGONNE,IL 60439. PHASE METR,SAN DIEGO,CA 92121. INST SOLID STATE PHYS,CHERNOGOLOVKA 142432,RUSSIA. RP WELP, U (reprint author), ARGONNE NATL LAB,DIV MAT SCI,9700 S CASS AVE,ARGONNE,IL 60439, USA. NR 19 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 J9 PHYSICA C JI Physica C PD DEC PY 1994 VL 235 BP 241 EP 244 DI 10.1016/0921-4534(94)91358-7 PN 1 PG 4 WC Physics, Applied SC Physics GA QA390 UT WOS:A1994QA39000064 ER PT J AU JOHNSTON, DC BAYLESS, WR BORSA, F CANFIELD, PC CHEONG, SW CHO, JH CHOU, FC FISK, Z JORGENSEN, JD LASCIALFARI, A MILLER, LL RADAELLI, PG SCHIRBER, JE SCHULTZ, AJ TORGESON, DR VAKNIN, D WAGNER, JL ZARESTKY, J ZIOLO, J AF JOHNSTON, DC BAYLESS, WR BORSA, F CANFIELD, PC CHEONG, SW CHO, JH CHOU, FC FISK, Z JORGENSEN, JD LASCIALFARI, A MILLER, LL RADAELLI, PG SCHIRBER, JE SCHULTZ, AJ TORGESON, DR VAKNIN, D WAGNER, JL ZARESTKY, J ZIOLO, J TI PHASE-SEPARATION AND DOPED-HOLE SEGREGATION IN LA2CUO4+DELTA AND LA2-XSRXCUO4+DELTA SO PHYSICA C LA English DT Article ID ELECTROCHEMICALLY OXIDIZED LA2CUO4+DELTA; SUPERCONDUCTORS; TEMPERATURE; DEPENDENCE; OXIDATION; DIAGRAM AB Herein, we review the magnetic, superconducting and structural phase diagrams of the title systems, with an emphasis on our recent results from magnetic and structural neutron diffraction, magnetic susceptibility and La-139 nuclear quadrupole resonance measurements. The results clarify the miscibility gap in the La2CuO4+delta system, and indicate the occurrence of frustrated phase separation on a nanoscopic length scale in the La2-xSrxCuO4 system with 0 < x less than or similar to 0.05. C1 IOWA STATE UNIV SCI & TECHNOL,DEPT PHYS & ASTRON,AMES,IA 50011. SANDIA NATL LABS,ALBUQUERQUE,NM 87185. UNIV PAVIA,DIPARTIMENTO FIS A VOLTA,I-27100 PAVIA,ITALY. AT&T BELL LABS,MURRAY HILL,NJ 07974. LOS ALAMOS NATL LAB,LOS ALAMOS,NM 87545. MIT,CTR MAT SCI & ENGN,CAMBRIDGE,MA 02139. ARGONNE NATL LAB,ARGONNE,IL 60439. SILESIAN UNIV,DEPT PHYS,PL-40007 KATOWICE,POLAND. RP JOHNSTON, DC (reprint author), IOWA STATE UNIV SCI & TECHNOL,AMES LAB,AMES,IA 50011, USA. RI Radaelli, Paolo/C-2952-2011; Canfield, Paul/H-2698-2014; Vaknin, David/B-3302-2009 OI Radaelli, Paolo/0000-0002-6717-035X; Vaknin, David/0000-0002-0899-9248 NR 19 TC 9 Z9 9 U1 1 U2 3 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0921-4534 J9 PHYSICA C JI Physica C PD DEC PY 1994 VL 235 BP 257 EP 260 DI 10.1016/0921-4534(94)91362-5 PN 1 PG 4 WC Physics, Applied SC Physics GA QA390 UT WOS:A1994QA39000068 ER PT J AU TETENBAUM, M HASH, M TANI, BS LUO, JS MARONI, VA AF TETENBAUM, M HASH, M TANI, BS LUO, JS MARONI, VA TI THERMODYNAMIC AND NONSTOICHIOMETRIC BEHAVIOR OF THE LEAD-DOPED BI-2223 SYSTEM SO PHYSICA C LA English DT Article AB Electromotive force (EMF) measurements of oxygen fugacities as a function of stoichiometry have been made in the lead-doped Bi-2223 superconducting system in the temperature range 700-815 degrees C, by means of an oxygen titration technique. The results of our studies indicate that processing or annealing lead-doped Bi-2223 at temperatures ranging from 700 to 815 degrees C and atm oxygen partial pressures ranging from similar to 0.02 to 0.2 atm should tend to preserve Bi-2223 as essentially single-phase material. Thermodynamic assessments of partial molar quantities indicate that the plateau regions can be represented by the diphasic CuO-Cu2O system. In accord with the EMF measurements, it was found that lead-doped Bi-2223 in a silver sheath is stable at 815 degrees C for oxygen partial pressures between 0.02 and 0.13 atm. Long-duration post anneals of silver-clad Bi-2223 filaments at 825 degrees C and an oxygen partial pressure of 0.075 atm eliminated Bi-2212 intergrowths with a concomitant increase in the superconducting transition sharpness. RP TETENBAUM, M (reprint author), ARGONNE NATL LAB,DIV CHEM TECHNOL,9700 S CASS AVE,ARGONNE,IL 60439, USA. NR 0 TC 5 Z9 5 U1 0 U2 0 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0921-4534 J9 PHYSICA C JI Physica C PD DEC PY 1994 VL 235 BP 321 EP 322 DI 10.1016/0921-4534(94)91384-6 PN 1 PG 2 WC Physics, Applied SC Physics GA QA390 UT WOS:A1994QA39000090 ER PT J AU DABROWSKI, B JORGENSEN, JD HITTERMAN, RL WAGNER, JL WANG, Z HUNTER, BA RADAELLI, PG HINKS, DG AF DABROWSKI, B JORGENSEN, JD HITTERMAN, RL WAGNER, JL WANG, Z HUNTER, BA RADAELLI, PG HINKS, DG TI SUPPRESSION OF SUPERCONDUCTIVITY IN ORTHORHOMBIC LA(2-X)M(X)CUO(4) (M=CA,SR) SO PHYSICA C LA English DT Article ID DISAPPEARANCE; LA2-XSRXCUO4 AB We have extended the calcium sold-solubility limit in La2-xCaxCuO4 to x = 0.2 using synthesis at high oxygen pressure. The superconducting transition temperature increases with doping to 34 K at x = 0.15 and is suppressed for x > 0.15, similar to the Sr-substituted material. At a fixed doping level, the optimum superconducting properties (the highest T-c) ate found for flat and square CuO2 planes. C1 ARGONNE NATL LAB,DIV MAT SCI,ARGONNE,IL 60439. RP DABROWSKI, B (reprint author), NO ILLINOIS UNIV,DEPT PHYS,DE KALB,IL 60115, USA. RI Radaelli, Paolo/C-2952-2011 OI Radaelli, Paolo/0000-0002-6717-035X NR 5 TC 2 Z9 2 U1 1 U2 2 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0921-4534 J9 PHYSICA C JI Physica C PD DEC PY 1994 VL 235 BP 339 EP 340 DI 10.1016/0921-4534(94)91393-5 PN 1 PG 2 WC Physics, Applied SC Physics GA QA390 UT WOS:A1994QA39000099 ER PT J AU GREENWOOD, KB ANDERSON, MT POEPPELMEIER, KR NOVIKOV, DL FREEMAN, AJ DABROWSKI, B GRAMSCH, SA BURDETT, JK AF GREENWOOD, KB ANDERSON, MT POEPPELMEIER, KR NOVIKOV, DL FREEMAN, AJ DABROWSKI, B GRAMSCH, SA BURDETT, JK TI STRUCTURE-PROPERTY RELATIONSHIPS IN LAYERED TIN-TITANIUM CUPRATES SO PHYSICA C LA English DT Article ID PEROVSKITE AB The synthesis of layered cuprates with single and double octahedral Sn-O and Ti-O layers has been achieved. C1 NORTHWESTERN UNIV,DEPT PHYS,EVANSTON,IL 60208. NO ILLINOIS UNIV,DEPT PHYS,DE KALB,IL 60115. ARGONNE NATL LAB,DIV MAT SCI,ARGONNE,IL 60439. UNIV CHICAGO,DEPT CHEM,CHICAGO,IL 60637. UNIV CHICAGO,JAMES FRANCK INST,CHICAGO,IL 60637. RP GREENWOOD, KB (reprint author), NORTHWESTERN UNIV,DEPT CHEM,2145 SHERIDAN RD,EVANSTON,IL 60208, USA. RI Gramsch, Stephen /K-1460-2015 OI Gramsch, Stephen /0000-0003-1031-1155 NR 6 TC 7 Z9 7 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 DEC PY 1994 VL 235 BP 349 EP 350 DI 10.1016/0921-4534(94)91398-6 PN 1 PG 2 WC Physics, Applied SC Physics GA QA390 UT WOS:A1994QA39000104 ER PT J AU JIANG, QD HUANG, KG RAO, M ZEGENHAGEN, J AF JIANG, QD HUANG, KG RAO, M ZEGENHAGEN, J TI THE INITIAL-STAGE OF THE EPITAXIAL-GROWTH OF RBA(2)CU(3)O(7-X) THIN-FILMS SO PHYSICA C LA English DT Article AB The structure of the (001) surface of Nb-doped SrTiO3 (STO), annealed at high temperature in UHV and in O-2, is investigated by LEED and STM. STM images of ultra-thin SmBCO films on STO suggest suppression of spiral growth. The lattice relaxation of epitaxial YBCO overlayer on STO is studied by grazing incidence x-ray diffraction (GIXRD). C1 ARGONNE NATL LAB,DIV MAT SCI,ARGONNE,IL 60439. RP JIANG, QD (reprint author), MAX PLANCK INST FESTKORPERFORSCH,POSTFACH 800665,D-70506 STUTTGART,GERMANY. NR 4 TC 10 Z9 10 U1 0 U2 3 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0921-4534 J9 PHYSICA C JI Physica C PD DEC PY 1994 VL 235 BP 677 EP 678 DI 10.1016/0921-4534(94)91562-8 PN 1 PG 2 WC Physics, Applied SC Physics GA QA390 UT WOS:A1994QA39000268 ER PT J AU SUBRAMANIAN, MA CRAWFORD, MK HARLOW, RL AMI, T FERNANDEZBACA, JA WANG, ZR JOHNSON, DC AF SUBRAMANIAN, MA CRAWFORD, MK HARLOW, RL AMI, T FERNANDEZBACA, JA WANG, ZR JOHNSON, DC TI SR2RHO4 AND SR2IRO4 - STRUCTURAL AND MAGNETIC STUDIES OF 4D AND 5D TRANSITION-METAL ANALOGS OF LA2CUO4 SO PHYSICA C LA English DT Article; Proceedings Paper CT International Conference on Materials and Mechanisms of Superconductivity - High Temperature Superconductors IV (M2S-HTSC IV) CY JUL 05-09, 1994 CL GRENOBLE, FRANCE SP EUROPEAN COMMUNITY, MINIST EDUC & SCI, FRANCE, CNRS, FRENCH NATL CTR SCI RES, RHONE ALPES REG, CITY GRENOBLE AB X-ray and neutron diffraction studies of Sr2IrO4 and Sr2RhO4 reveal structural distortions from the ideal K2NiF4 structure, in which the IrO6 and RhO6 octahedra are rotated about the crystallographic c-axes by 11 degrees or 9.7 degrees, respectively. These rotations reduce the symmetry from I4/mmm to I4(1)/acd. We find that Sr2IrO4 is an electrical insulator which exhibits weak ferromagnetism at 250 K, attributable to canted antiferromagnetism associated with long-range three-dimensional ordering of the Ir4+ moments. Although no ferromagnetic ordering is found in Sr2RhO4, susceptibility data shows a peak possibly associated with two-dimensional short-range antiferromagnetic order. Doping of electrons in Sr2RhO4 results in compositions which show weak ferromagnetism, perhaps arising from double-exchange-type magnetic interactions due to the presence of rhodium in 4(+) and 3(+) oxidation states. C1 OAK RIDGE NATL LAB,OAK RIDGE,TN 37831. IOWA STATE UNIV SCI & TECHNOL,AMES LAB,AMES,IA 50011. RP SUBRAMANIAN, MA (reprint author), DUPONT CO INC,EXPTL STN,WILMINGTON,DE 19880, USA. RI Fernandez-Baca, Jaime/C-3984-2014 OI Fernandez-Baca, Jaime/0000-0001-9080-5096 NR 6 TC 38 Z9 38 U1 6 U2 38 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0921-4534 J9 PHYSICA C JI Physica C PD DEC PY 1994 VL 235 BP 743 EP 744 DI 10.1016/0921-4534(94)91596-2 PN 2 PG 2 WC Physics, Applied SC Physics GA QC694 UT WOS:A1994QC69400012 ER PT J AU KATANO, S MORI, N UEDA, Y FERNANDEZBACA, JA FUNAHASHI, S AF KATANO, S MORI, N UEDA, Y FERNANDEZBACA, JA FUNAHASHI, S TI STRUCTURAL PHASE-TRANSITIONS AND SUPERCONDUCTIVITY OF LA2-XBAXCUO4 WITH X=0.125 - EFFECTS OF PRESSURE AND SR SUBSTITUTION SO PHYSICA C LA English DT Article; Proceedings Paper CT International Conference on Materials and Mechanisms of Superconductivity - High Temperature Superconductors IV (M2S-HTSC IV) CY JUL 05-09, 1994 CL GRENOBLE, FRANCE SP EUROPEAN COMMUNITY, MINIST EDUC & SCI, FRANCE, CNRS, FRENCH NATL CTR SCI RES, RHONE ALPES REG, CITY GRENOBLE AB Neutron diffraction and magnetic susceptibility under high pressure show clear correlations between structural phase transitions and superconductivity in La2-xBaxCuO4 with x=0.125. The bulk superconducting transition temperature T-c changes drastically at the pressures where the structural phase transitions take place. Characteristics of structure changes in the Sr-substituted system as well as under high pressure are presented. C1 UNIV TOKYO,INST SOLID STATE PHYS,MINATO KU,TOKYO 106,JAPAN. OAK RIDGE NATL LAB,DIV SOLID STATE,OAK RIDGE,TN 37831. RP KATANO, S (reprint author), JAPAN ATOM ENERGY RES INST,DEPT MAT SCI & ENGN,TOKAI,IBARAKI 31911,JAPAN. RI Fernandez-Baca, Jaime/C-3984-2014 OI Fernandez-Baca, Jaime/0000-0001-9080-5096 NR 4 TC 0 Z9 0 U1 0 U2 0 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0921-4534 J9 PHYSICA C JI Physica C PD DEC PY 1994 VL 235 BP 837 EP 838 DI 10.1016/0921-4534(94)91643-8 PN 2 PG 2 WC Physics, Applied SC Physics GA QC694 UT WOS:A1994QC69400058 ER PT J AU OXX, S WILLEMSEN, BA LI, QA SHIBUTANI, K SHIGAKI, I OGAWA, R SRIDHAR, S AF OXX, S WILLEMSEN, BA LI, QA SHIBUTANI, K SHIGAKI, I OGAWA, R SRIDHAR, S TI PENETRATION DEPTH AND MICROWAVE SURFACE-RESISTANCE OF BI2SR2CACU2O8 SINGLE-CRYSTALS SO PHYSICA C LA English DT Article; Proceedings Paper CT International Conference on Materials and Mechanisms of Superconductivity - High Temperature Superconductors IV (M2S-HTSC IV) CY JUL 05-09, 1994 CL GRENOBLE, FRANCE SP EUROPEAN COMMUNITY, MINIST EDUC & SCI, FRANCE, CNRS, FRENCH NATL CTR SCI RES, RHONE ALPES REG, CITY GRENOBLE ID TEMPERATURE-DEPENDENCE; SUPERCONDUCTORS AB The penetration depth lambda and the surface resistance R(s) of BSCCO single crystals were measured at 10 GHz using a special Nb cavity. At low temperatures, Delta lambda proportional to T-2, inconsistent with pure s- or d- wave symmetry, but suggestive of strong impurity scattering. Near T-c the data are inconsistent with a two-fluid or BCS s-wave model. An unusual peak is observed in R(s) near T-c and is attributed to fluctuations. C1 BROOKHAVEN NATL LAB,DEPT APPL SCI,DIV MAT SCI,UPTON,NY 11973. KOBE STEEL LTD,CTR SUPERCONDUCTING & CRYOGEN TECHNOL,NISHI KU,KOBE 65122,JAPAN. RP OXX, S (reprint author), NORTHEASTERN UNIV,DEPT PHYS,360 HUNTINGTON AVE,BOSTON,MA 02115, USA. RI Sridhar, Srinivas/A-3688-2012 NR 9 TC 7 Z9 7 U1 0 U2 1 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0921-4534 J9 PHYSICA C JI Physica C PD DEC PY 1994 VL 235 BP 889 EP 890 DI 10.1016/0921-4534(94)91669-1 PN 2 PG 2 WC Physics, Applied SC Physics GA QC694 UT WOS:A1994QC69400084 ER PT J AU AMI, T CRAWFORD, MK HARLOW, RL LI, ZG VOGT, T ZHU, Q COX, DE AF AMI, T CRAWFORD, MK HARLOW, RL LI, ZG VOGT, T ZHU, Q COX, DE TI A NEUTRON AND SYNCHROTRON X-RAY-SCATTERING STUDY OF SR2CUO3+DELTA SYNTHESIZED UNDER MODERATE PRESSURE - A NEW COMPOUND RELATED TO SUPERCONDUCTING SR2CUO3.1 SO PHYSICA C LA English DT Article; Proceedings Paper CT International Conference on Materials and Mechanisms of Superconductivity - High Temperature Superconductors IV (M2S-HTSC IV) CY JUL 05-09, 1994 CL GRENOBLE, FRANCE SP EUROPEAN COMMUNITY, MINIST EDUC & SCI, FRANCE, CNRS, FRENCH NATL CTR SCI RES, RHONE ALPES REG, CITY GRENOBLE ID COPPER AB Recently, a new family of cuprate superconductors, Sr2CuO3+delta was stabilized at a pressure of 60 kbar(1). Here we report the synthesis at moderate pressures of 50 similar to 3000 bar of a non-superconducting material with a closely related structure. The x-ray diffraction pattern of this lower-pressure phase, also described as Sr2CuO3+delta, is neatly identical with that of the superconducting phase, and TEM measurements demonstrate the presence of a 4 root 2a x 4 root 2a x c superstructure. The results of a high resolution synchrotron x-ray diffraction study indicate a slight orthorhombic distortion in this phase compared to the tetragonal superconducting phase. Rietveld refinement of neutron diffraction data, assuming a K2NiF4-type structure, reveals the presence of oxygen vacancies in the Cu-O-2 planes. C1 DUPONT CO INC,EXPTL STN,CR&D,WILMINGTON,DE 19880. BROOKHAVEN NATL LAB,DEPT PHYS,UPTON,NY 11973. RP AMI, T (reprint author), SONY CORP,RES CTR,HODOGAYA KU,174 FUJITSUKA CHO,YOKOHAMA,KANAGAWA 240,JAPAN. RI Vogt, Thomas /A-1562-2011 OI Vogt, Thomas /0000-0002-4731-2787 NR 6 TC 9 Z9 9 U1 0 U2 2 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0921-4534 J9 PHYSICA C JI Physica C PD DEC PY 1994 VL 235 BP 1003 EP 1004 DI 10.1016/0921-4534(94)91726-4 PN 2 PG 2 WC Physics, Applied SC Physics GA QC694 UT WOS:A1994QC69400141 ER PT J AU KIRCHER, J MILLER, D RICHARDS, PL KALDIS, E KARPINSKI, J AF KIRCHER, J MILLER, D RICHARDS, PL KALDIS, E KARPINSKI, J TI DIRECT MEASUREMENT OF THE OPTICAL-ABSORPTION IN YBA2CU4O8 SO PHYSICA C LA English DT Article; Proceedings Paper CT International Conference on Materials and Mechanisms of Superconductivity - High Temperature Superconductors IV (M2S-HTSC IV) CY JUL 05-09, 1994 CL GRENOBLE, FRANCE SP EUROPEAN COMMUNITY, MINIST EDUC & SCI, FRANCE, CNRS, FRENCH NATL CTR SCI RES, RHONE ALPES REG, CITY GRENOBLE AB In this work we present direct measurements of the anisotropic optical absorption of YBa2Cu4O8. By measuring the photon energy dependent response of a composite bolometer with the sample as absorber and its comparison with the characteristics of a known bolometer we are able to deduce the absorptivity (and thus also the reflectance) of the investigated sample extremely accurately. C1 UNIV CALIF BERKELEY,LAWRENCE BERKELEY LAB,DIV SCI MAT,BERKELEY,CA 94720. ETH ZURICH,FESTKORPERPHYS LAB,CH-8093 ZURICH,SWITZERLAND. RP KIRCHER, J (reprint author), UNIV CALIF BERKELEY,DEPT PHYS,BERKELEY,CA 94720, USA. NR 8 TC 0 Z9 0 U1 0 U2 0 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0921-4534 J9 PHYSICA C JI Physica C PD DEC PY 1994 VL 235 BP 1119 EP 1120 DI 10.1016/0921-4534(94)91784-1 PN 2 PG 2 WC Physics, Applied SC Physics GA QC694 UT WOS:A1994QC69400199 ER PT J AU BILLINGE, SJL KWEI, GH TAKAGI, H AF BILLINGE, SJL KWEI, GH TAKAGI, H TI STRUCTURAL GROUND-STATE OF LA2CUO4 IN THE LTO PHASE - EVIDENCE OF LOCAL DISORDER SO PHYSICA C LA English DT Article; Proceedings Paper CT International Conference on Materials and Mechanisms of Superconductivity - High Temperature Superconductors IV (M2S-HTSC IV) CY JUL 05-09, 1994 CL GRENOBLE, FRANCE SP EUROPEAN COMMUNITY, MINIST EDUC & SCI, FRANCE, CNRS, FRENCH NATL CTR SCI RES, RHONE ALPES REG, CITY GRENOBLE AB We present neutron scattering data which indicate that the local structure of La2CuO4 in the LTO phase is disordered. Data from two different diffractometers are compared and systematic differences between the pair distribution functions (PDF) of the LTO model and the data are reproduced in both cases. C1 UNIV TOKYO,BUNKYO KU,TOKYO 113,JAPAN. RP BILLINGE, SJL (reprint author), LOS ALAMOS NATL LAB,MS K764,LOS ALAMOS,NM 87545, USA. RI Takagi, Hidenori/B-2935-2010 NR 8 TC 0 Z9 0 U1 1 U2 2 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0921-4534 J9 PHYSICA C JI Physica C PD DEC PY 1994 VL 235 BP 1281 EP 1282 DI 10.1016/0921-4534(94)91865-1 PN 2 PG 2 WC Physics, Applied SC Physics GA QC694 UT WOS:A1994QC69400280 ER PT J AU LACERDA, A GRAF, T CHO, JH THOMPSON, JD MALEY, MP AF LACERDA, A GRAF, T CHO, JH THOMPSON, JD MALEY, MP TI HIGH-FIELD MAGNETORESISTANCE OF LA1.99SR0.01CUO4+DELTA SO PHYSICA C LA English DT Article; Proceedings Paper CT International Conference on Materials and Mechanisms of Superconductivity - High Temperature Superconductors IV (M2S-HTSC IV) CY JUL 05-09, 1994 CL GRENOBLE, FRANCE SP EUROPEAN COMMUNITY, MINIST EDUC & SCI, FRANCE, CNRS, FRENCH NATL CTR SCI RES, RHONE ALPES REG, CITY GRENOBLE AB The in-plane resistance of a La1.99Sr0.01CuO4 single crystal has been measured as a function of temperature (4K 200K) La-139 NMR relaxation rates in single crystals of La2CuO4+delta at two measuring frequencies are compared with zero field NQR measurements in order to study the diffusion of the interstitial oxygen. C1 IOWA STATE UNIV SCI & TECHNOL, US DOE, AMES LAB, AMES, IA 50011 USA. IOWA STATE UNIV SCI & TECHNOL, DEPT PHYS & ASTRON, AMES, IA 50011 USA. RP RUBINI, S (reprint author), UNIV PAVIA, DIPARTIMENTO FIS A VOLTA, I-27100 PAVIA, ITALY. RI Rubini, Silvia/C-8369-2012; Canfield, Paul/H-2698-2014 OI Rubini, Silvia/0000-0001-5215-2223; NR 4 TC 12 Z9 12 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 DEC PY 1994 VL 235 BP 1717 EP 1718 DI 10.1016/0921-4534(94)92080-X PN 3 PG 2 WC Physics, Applied SC Physics GA QC695 UT WOS:A1994QC69500088 ER PT J AU PHILLIPS, NE EMERSON, JP FISHER, RA GORDON, JE WOODFIELD, BF WRIGHT, DA AF PHILLIPS, NE EMERSON, JP FISHER, RA GORDON, JE WOODFIELD, BF WRIGHT, DA TI IS THERE AN INTRINSIC LINEAR TERM IN THE SPECIFIC-HEAT OF YB2CU3O7 SO PHYSICA C LA English DT Article ID SUPERCONDUCTORS AB A reanalysis of specific-heat data suggests the existence of an intrinsic contribution to the linear term of the order of 2 mJ/mole.K-2 in YBCO. On the basis of comparison with other high-T-c oxide superconductors it appears that the intrinsic contribution may be unique to YBCO, and therefore probably associated with the CuO chains. C1 AMHERST COLL,DEPT PHYS,AMHERST,MA 01002. RP PHILLIPS, NE (reprint author), UNIV CALIF BERKELEY,LAWRENCE BERKELEY LAB,BERKELEY,CA 94720, USA. NR 9 TC 3 Z9 3 U1 0 U2 2 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0921-4534 J9 PHYSICA C JI Physica C PD DEC PY 1994 VL 235 BP 1737 EP 1738 DI 10.1016/0921-4534(94)92090-7 PN 3 PG 2 WC Physics, Applied SC Physics GA QC695 UT WOS:A1994QC69500098 ER PT J AU WOODFIELD, BF CHU, CW FISHER, RA GORDON, JE LONG, SB PHILLIPS, NE XIONG, Q AF WOODFIELD, BF CHU, CW FISHER, RA GORDON, JE LONG, SB PHILLIPS, NE XIONG, Q TI THE SPECIFIC-HEAT OF HGBA2CUO4+DELTA SO PHYSICA C LA English DT Article ID HIGH-TC; SUPERCONDUCTIVITY AB The specific heat of a polycrystalline sample of HgBa2CuO4+delta has been measured between 0.6 and 240K in zero field and in magnetic fields to 9T between 0.6 and 120K. The anomaly near T-c is small and appears to arise largely from fluctuation effects. C1 UNIV HOUSTON,TCSUH,HOUSTON,TX 77204. AMHERST COLL,DEPT PHYS,AMHERST,MA 01002. RP WOODFIELD, BF (reprint author), UNIV CALIF BERKELEY,LAWRENCE BERKELEY LAB,BERKELEY,CA 94720, USA. NR 6 TC 7 Z9 7 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 DEC PY 1994 VL 235 BP 1741 EP 1742 DI 10.1016/0921-4534(94)92092-3 PN 3 PG 2 WC Physics, Applied SC Physics GA QC695 UT WOS:A1994QC69500100 ER PT J AU FISHER, RA PHILLIPS, NE WRIGHT, DA RADOUSKY, HB GOODWIN, TJ PENG, JL SHELTON, RN ZHANG, L AF FISHER, RA PHILLIPS, NE WRIGHT, DA RADOUSKY, HB GOODWIN, TJ PENG, JL SHELTON, RN ZHANG, L TI THE SPECIFIC-HEAT OF (Y1-XPRX)BA2CU3O7 - EFFECTS OF PR3+ SINGLET-GROUND STATE ORDERING AND PR-O HYBRIDIZATION SO PHYSICA C LA English DT Article ID TEMPERATURE SPECIFIC-HEAT; LINEAR CONTRIBUTIONS; SUPERCONDUCTIVITY; HYPERFINE AB Specific-heat measurements suggest that the Pr valence in (Y1-xPrx)Ba2Cu3O7 is +3, and that Pr hybridization with the CuO2 planes results in an entropy excess over that expected from the Pr3+ crystal-field states. C1 LAWRENCE LIVERMORE NATL LAB,LIVERMORE,CA 94550. UNIV CALIF DAVIS,DEPT PHYS,DAVIS,CA 95616. RP FISHER, RA (reprint author), UNIV CALIF BERKELEY,LAWRENCE BERKELEY LAB,BERKELEY,CA 94720, USA. NR 8 TC 4 Z9 4 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 DEC PY 1994 VL 235 BP 1749 EP 1750 DI 10.1016/0921-4534(94)92096-6 PN 3 PG 2 WC Physics, Applied SC Physics GA QC695 UT WOS:A1994QC69500104 ER PT J AU ROMANO, P DILEO, R CUCOLO, AM NIGRO, A DABROWSKI, B RADAELLI, PG AF ROMANO, P DILEO, R CUCOLO, AM NIGRO, A DABROWSKI, B RADAELLI, PG TI TUNNEL-JUNCTIONS ON 1/2/4-Y-BA-CU-O SINGLE-CRYSTALS SO PHYSICA C LA English DT Article ID SUPERCONDUCTORS; STATE AB We have studied the 1:2:4 phase of the Y-Ba-Cu-O compound by means of tunneling spectroscopy on single crystal based junctions. The crystals, with T-c approximate to 80 K, have been chemically etched before the deposition of the counterelectrode in form of a thin film through a metallic mask. We have compared the tunneling spectra to those obtained on the Y123 system. The features at +/-20 mV of the 1:2:3 phase are still observed in the 1:2:4 phase, while the low bias features at +/-5 mV are not present in the tunneling characteristics of the Y124 compound. The experimental results are discussed in terms of the different CuO chain role in the Y123 and Y124 systems. C1 ARGONNE NATL LAB,DIV MAT SCI,ARGONNE,IL 60439. NO ILLINOIS UNIV,DEPT PHYS,DE KALB,IL 60115. RP ROMANO, P (reprint author), UNIV SALERNO,DIPARTIMENTO FIS,I-84081 BARONISSI,ITALY. RI Radaelli, Paolo/C-2952-2011 OI Radaelli, Paolo/0000-0002-6717-035X NR 7 TC 1 Z9 1 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 DEC PY 1994 VL 235 BP 1913 EP 1914 DI 10.1016/0921-4534(94)92178-4 PN 3 PG 2 WC Physics, Applied SC Physics GA QC695 UT WOS:A1994QC69500186 ER PT J AU PATAPIS, SK JONES, EC PHILLIPS, JM LOWNDES, DH SOMEKH, RE AF PATAPIS, SK JONES, EC PHILLIPS, JM LOWNDES, DH SOMEKH, RE TI FLUCTUATIONS AND THE MAKI-THOMPSON MODEL IN YBA2CU3O7 THIN-FILMS SO PHYSICA C LA English DT Article ID SUPERCONDUCTORS; CONDUCTIVITY AB The fluctuation conductivity is analysed for different epitaxial thin films of YBaCuO grown on various substrates such as LaAlO3 KTO3 and MgO. The findings, without fitting parameters, are explicitly consistent with the paraconductivity model proposed by Maki and Thompson for thin films. C1 OAK RIDGE NATL LAB,DIV SOLID STATE,OAK RIDGE,TN 37831. UNIV TENNESSEE,DEPT PHYS,KNOXVILLE,TN 37996. AT&T BELL LABS,MURRAY HILL,NJ 07974. UNIV CAMBRIDGE,DEPT MAT SCI & MET,CAMBRIDGE CB2 3QZ,ENGLAND. RP PATAPIS, SK (reprint author), UNIV ATHENS,DEPT PHYS,DIV SOLID STATE,ATHENS,GREECE. NR 7 TC 2 Z9 2 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 DEC PY 1994 VL 235 BP 1965 EP 1966 DI 10.1016/0921-4534(94)92204-7 PN 3 PG 2 WC Physics, Applied SC Physics GA QC695 UT WOS:A1994QC69500212 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 QUASI-PARTICLE HALL-EFFECT IN SUPERCONDUCTING YBA2CU3O7-DELTA SO PHYSICA C LA English DT Article ID MICROWAVE AB Coherent time-domain spectroscopy was used to measure the complex transmission tenser of three YBa2Cu3O7-delta thin films in magnetic fields up to 6 T at temperatures from 10 to 200 K. The complex conductivity tenser was determined from transmission measurements in the frequency range 100-800 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 ten. This behavior rs 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), UNIV CALIF BERKELEY,LAWRENCE BERKELEY LAB,DIV MAT SCI,BERKELEY,CA 94720, USA. RI Orenstein, Joseph/I-3451-2015 NR 6 TC 1 Z9 1 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 DEC PY 1994 VL 235 BP 2021 EP 2022 DI 10.1016/0921-4534(94)92232-2 PN 3 PG 2 WC Physics, Applied SC Physics GA QC695 UT WOS:A1994QC69500240 ER PT J AU GOETTEE, JD KUDASOV, YB ZERWEKH, WD BYKOV, AI DOLOTENKO, MI FOWLER, CM FEEMAN, BL KING, JC KOLOKOLCHIKOV, NP LEWIS, W MARSHALL, BR PAPATHEOFANIS, BJ PLATONOV, VV RODRIGUEZ, PJ SHEPPARD, MG TATSENKO, OM VEESER, LR AF GOETTEE, JD KUDASOV, YB ZERWEKH, WD BYKOV, AI DOLOTENKO, MI FOWLER, CM FEEMAN, BL KING, JC KOLOKOLCHIKOV, NP LEWIS, W MARSHALL, BR PAPATHEOFANIS, BJ PLATONOV, VV RODRIGUEZ, PJ SHEPPARD, MG TATSENKO, OM VEESER, LR TI COMPLEX MICROWAVE CONDUCTIVITY OF YBA2CU3O7 IN MAGNETIC-FIELDS UP TO 500T SO PHYSICA C LA English DT Article AB We have measured the complex conductivity of thin films of YBa2Cu3O7 (YBCO) superconductor down to temperatures of 4K and magnetic fields up to 500T. The highly oriented films were probed by 94 GHz radiation, with the external magnetic field applied perpendicular to the c-axis. As discussed below, these measurements allowed us to assign a value of 340+/-40 T for the upper critical field at T=0. The measurements were recently carried out at the pulsed field facility of the National High Magnetic Field Laboratory at Los Alamos using both Russian and American magnetic flux compression generators. C1 ALL RUSSIAN SCI EXPTL PHYS RES INST,ARZAMAS 607200,RUSSIA. EG&G ENERGY MEASUREMENTS INC,GOLETA,CA 93117. RP GOETTEE, JD (reprint author), LOS ALAMOS NATL LAB,POB 1663,LOS ALAMOS,NM 87545, USA. RI Goettee, Jeffrey/L-4926-2015 NR 4 TC 15 Z9 15 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 DEC PY 1994 VL 235 BP 2090 EP 2091 DI 10.1016/0921-4534(94)92266-7 PN 3 PG 2 WC Physics, Applied SC Physics GA QC695 UT WOS:A1994QC69500274 ER PT J AU JIA, YX LEE, CS ZETTL, A AF JIA, YX LEE, CS ZETTL, A TI STABILIZATION OF THE TL2BA2CA2CU3O10 SUPERCONDUCTOR BY HG DOPING SO PHYSICA C LA English DT Article ID CU-O SYSTEM AB Hg doping of the triple-CuO2 layer oxide superconductor T2-xHgxBa2Ca2Cu3O10 (Tl-2223) is investigated. Modest substitution of Hg2+ ions for Tl3+ ions leads to the stabilization of the Tl-2223 structure and an apparently optimized superconducting onset temperature T-c=130 K. The situation is reminiscent of partial Bi ions replacement by Pb ions in the lower-T-c Bi based oxide superconductors. Overdoping with Hg in Tl-2223 leads again to a decrease in T-c. C1 UNIV CALIF BERKELEY,LAWRENCE BERKELEY LAB,DIV MAT SCI,BERKELEY,CA 94720. RP JIA, YX (reprint author), UNIV CALIF BERKELEY,DEPT PHYS,BERKELEY,CA 94720, USA. RI Zettl, Alex/O-4925-2016 OI Zettl, Alex/0000-0001-6330-136X NR 8 TC 8 Z9 8 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 DEC 1 PY 1994 VL 234 IS 1-2 BP 24 EP 28 DI 10.1016/0921-4534(94)90049-3 PG 5 WC Physics, Applied SC Physics GA PV779 UT WOS:A1994PV77900004 ER PT J AU FEHRENBACHER, R NORMAN, MR AF FEHRENBACHER, R NORMAN, MR TI CAN IMPURITY EFFECTS HELP TO IDENTIFY THE SYMMETRY OF THE ORDER-PARAMETER OF THE CUPRATES SO PHYSICA C-SUPERCONDUCTIVITY AND ITS APPLICATIONS LA English DT Article; Proceedings Paper CT International Conference on Materials and Mechanisms of Superconductivity - High Temperature Superconductors IV (M2S-HTSC IV) CY JUL 05-09, 1994 CL GRENOBLE, FRANCE SP EUROPEAN COMMUNITY, MINIST EDUC & SCI, FRANCE, CNRS, FRENCH NATL CTR SCI RES, RHONE ALPES REG, CITY GRENOBLE ID SUPERCONDUCTORS AB The effects of non-magnetic impurities on the properties of superconductors with order parameters (OF) of different symmetry are discussed. In particular, we contrast the case of a d(x2-y2) with various forms of an anisotropic s-wave (ASW) gap. The biggest qualitative difference occurs if the phase of the s-wave OP does not change sign. RP FEHRENBACHER, R (reprint author), ARGONNE NATL LAB,DIV MAT SCI,SCI & TECHNOL CTR SUPERCONDUCT,9700 S CASS AVE,ARGONNE,IL 60439, USA. RI Norman, Michael/C-3644-2013 NR 5 TC 11 Z9 11 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 DEC PY 1994 VL 235 BP 2407 EP 2408 DI 10.1016/0921-4534(94)92424-4 PN 4 PG 2 WC Physics, Applied SC Physics GA QC696 UT WOS:A1994QC69600129 ER PT J AU WOLF, SA KRESIN, VZ AF WOLF, SA KRESIN, VZ TI SYMMETRY OF THE PAIRING, ISOTOPE EFFECT AND MECHANISM OF SUPERCONDUCTIVITY IN THE CUPRATES SO PHYSICA C-SUPERCONDUCTIVITY AND ITS APPLICATIONS LA English DT Article; Proceedings Paper CT International Conference on Materials and Mechanisms of Superconductivity - High Temperature Superconductors IV (M2S-HTSC IV) CY JUL 05-09, 1994 CL GRENOBLE, FRANCE SP EUROPEAN COMMUNITY, MINIST EDUC & SCI, FRANCE, CNRS, FRENCH NATL CTR SCI RES, RHONE ALPES REG, CITY GRENOBLE ID TEMPERATURE-DEPENDENCE; YBA2CU3O7-DELTA; STATE AB This article will briefly discuss the symmetry of the pairing, the isotope effect and the strong coupling of the carriers to the optical phonon modes which is strong enough to provide high T-C. C1 ADV RES PROJECT AGCY,DEF SCI OFF,ARLINGTON,VA 22203. UNIV CALIF BERKELEY,LAWRENCE BERKELEY LAB,BERKELEY,CA 94720. RP WOLF, SA (reprint author), USN,RES LAB,MAT PHYS BRANCH,WASHINGTON,DC 20375, USA. RI Wolf, Stuart/A-7513-2009 NR 15 TC 0 Z9 0 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 DEC PY 1994 VL 235 BP 2413 EP 2414 DI 10.1016/0921-4534(94)92427-9 PN 4 PG 2 WC Physics, Applied SC Physics GA QC696 UT WOS:A1994QC69600132 ER PT J AU AMANN, A VISANI, P AUPKE, K MOTA, AC MAPLE, MB DALICHAOUCH, Y ARMSTRONG, PE FISK, Z MITIN, AV AF AMANN, A VISANI, P AUPKE, K MOTA, AC MAPLE, MB DALICHAOUCH, Y ARMSTRONG, PE FISK, Z MITIN, AV TI UNCONVENTIONAL FLUX DYNAMICS IN THE HEAVY-FERMION SUPERCONDUCTORS UPT3 AND UBE13 SO PHYSICA C-SUPERCONDUCTIVITY AND ITS APPLICATIONS LA English DT Article; Proceedings Paper CT International Conference on Materials and Mechanisms of Superconductivity - High Temperature Superconductors IV (M2S-HTSC IV) CY JUL 05-09, 1994 CL GRENOBLE, FRANCE SP EUROPEAN COMMUNITY, MINIST EDUC & SCI, FRANCE, CNRS, FRENCH NATL CTR SCI RES, RHONE ALPES REG, CITY GRENOBLE AB We have investigated flux creep in single crystals of UPt3 (H//c) and UBe13 (H//c(4)) in the temperature range 5 mK < T < T-c and for magnetic fields H < 0.2 T. The relaxation curves for both of these heavy fermion superconductors show novel behaviours, with decay laws which depend strongly on the applied field. At all temperatures, we observe contributions to the decays which seem to arise from different processes with different time dependences, namely logarithmic and stretched exponential. C1 UNIV CALIF SAN DIEGO, DEPT PHYS, LA JOLLA, CA 92093 USA. UNIV CALIF SAN DIEGO, IPAP, LA JOLLA, CA 92093 USA. LOS ALAMOS NATL LAB, LOS ALAMOS, NM 87545 USA. PL KAPITZA PHYS PROBLEMS INST, MOSCOW 117334, RUSSIA. RP ETH HONGGERBERG, FESTKORPERPHYS LAB, CH-8093 ZURICH, SWITZERLAND. NR 5 TC 2 Z9 2 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 DEC PY 1994 VL 235 BP 2443 EP 2444 DI 10.1016/0921-4534(94)92442-2 PN 4 PG 2 WC Physics, Applied SC Physics GA QC696 UT WOS:A1994QC69600147 ER PT J AU GONZALEZ, MA VELEZ, M VICENT, JL SCHLEUTER, J WILLIAMS, JM CRABTREE, GW AF GONZALEZ, MA VELEZ, M VICENT, JL SCHLEUTER, J WILLIAMS, JM CRABTREE, GW TI AC SUSCEPTIBILITY AND CRITICAL-CURRENT IN THE ORGANIC SUPERCONDUCTOR KAPPA-(ET)(2)CU(NCS)(2) SO PHYSICA C-SUPERCONDUCTIVITY AND ITS APPLICATIONS LA English DT Article; Proceedings Paper CT International Conference on Materials and Mechanisms of Superconductivity - High Temperature Superconductors IV (M2S-HTSC IV) CY JUL 05-09, 1994 CL GRENOBLE, FRANCE SP EUROPEAN COMMUNITY, MINIST EDUC & SCI, FRANCE, CNRS, FRENCH NATL CTR SCI RES, RHONE ALPES REG, CITY GRENOBLE AB The AC susceptibility (chi', chi'') has been measured in a single crystal of the organic superconductor kappa-(ET)(2)Cu(NCS)(2) (T-c=9.5 K) as a function of the DC magnetic field, for several frequencies (10(2) Hz j(t). j(t) exceeds essentially the critical current j(c) for strongly disordered systems and approaches j(c) with the decrease of the degree of disorder. We find that it diverges as temperature approaches the melting temperature of the undisturbed lattice. C1 CHERNOGOLOVKA SOLID STATE PHYS INST,CHERNOGOLOVKA 142432,RUSSIA. RP KOSHELEV, AE (reprint author), ARGONNE NATL LAB,9700 S CASS AVE,ARGONNE,IL 60439, USA. RI Koshelev, Alexei/K-3971-2013 OI Koshelev, Alexei/0000-0002-1167-5906 NR 4 TC 0 Z9 0 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 DEC PY 1994 VL 235 BP 2655 EP 2656 DI 10.1016/0921-4534(94)92548-8 PN 4 PG 2 WC Physics, Applied SC Physics GA QC696 UT WOS:A1994QC69600253 ER PT J AU KHAYKOVICH, B ZELDOV, E KONCZYKOWSKI, M MAJER, D LARKIN, AI CLEM, JR AF KHAYKOVICH, B ZELDOV, E KONCZYKOWSKI, M MAJER, D LARKIN, AI CLEM, JR TI VORTEX DYNAMICS IN A RING-LIKE IRRADIATED BI2SR2CACU2O8 CRYSTAL SO PHYSICA C-SUPERCONDUCTIVITY AND ITS APPLICATIONS LA English DT Article; Proceedings Paper CT International Conference on Materials and Mechanisms of Superconductivity - High Temperature Superconductors IV (M2S-HTSC IV) CY JUL 05-09, 1994 CL GRENOBLE, FRANCE SP EUROPEAN COMMUNITY, MINIST EDUC & SCI, FRANCE, CNRS, FRENCH NATL CTR SCI RES, RHONE ALPES REG, CITY GRENOBLE AB A Bi2Sr2CaCu2O8 crystal selectively irradiated near the edges is studied using a Hall-sensor array. Vortices penetrating into the central J(c) = 0 region are ''focused'' in the center of the sample on increasing the applied field. In decreasing field, vortices leave the center and a large vortex accumulation is observed on the inner rim of the irradiated region. Spatially resolved magnetization measurements confirm the developed theoretical model. C1 ECOLE POLYTECH,SOLIDES IRRADIES LAB,F-91128 PALAISEAU,FRANCE. LD LANDAU THEORET PHYS INST,MOSCOW 117940,RUSSIA. US DOE,AMES LAB,AMES,IA 50011. IOWA STATE UNIV SCI & TECHNOL,AMES,IA 50011. RP KHAYKOVICH, B (reprint author), WEIZMANN INST SCI,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 4 TC 13 Z9 13 U1 0 U2 2 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0921-4534 J9 PHYSICA C JI Physica C PD DEC PY 1994 VL 235 BP 2757 EP 2758 DI 10.1016/0921-4534(94)92599-2 PN 4 PG 2 WC Physics, Applied SC Physics GA QC696 UT WOS:A1994QC69600304 ER PT J AU ZELDOV, E LARKIN, AI KONCZYKOWSKI, M KHAYKOVICH, B MAJER, D GESHKENBEIN, VB VINOKUR, VM AF ZELDOV, E LARKIN, AI KONCZYKOWSKI, M KHAYKOVICH, B MAJER, D GESHKENBEIN, VB VINOKUR, VM TI GEOMETRICAL BARRIERS IN TYPE-II SUPERCONDUCTORS SO PHYSICA C-SUPERCONDUCTIVITY AND ITS APPLICATIONS LA English DT Article; Proceedings Paper CT International Conference on Materials and Mechanisms of Superconductivity - High Temperature Superconductors IV (M2S-HTSC IV) CY JUL 05-09, 1994 CL GRENOBLE, FRANCE SP EUROPEAN COMMUNITY, MINIST EDUC & SCI, FRANCE, CNRS, FRENCH NATL CTR SCI RES, RHONE ALPES REG, CITY GRENOBLE AB Vortex penetration in thin flat samples in perpendicular fields is governed by geometrical barrier effect. The main features of this novel barrier is vortex accumulation in the center of the sample and irreversible magnetization in the absence of bulk pinning. The developed theoretical model is confirmed by experimental results. 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,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 5 TC 30 Z9 30 U1 0 U2 3 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0921-4534 J9 PHYSICA C JI Physica C PD DEC PY 1994 VL 235 BP 2761 EP 2762 DI 10.1016/0921-4534(94)92601-8 PN 4 PG 2 WC Physics, Applied SC Physics GA QC696 UT WOS:A1994QC69600306 ER PT J AU MAJER, D ZELDOV, E KONCZYKOWSKI, M GESHKENBEIN, VB LARKIN, AI BURLACHKOV, L VINOKUR, VM CHIKUMOTO, N AF MAJER, D ZELDOV, E KONCZYKOWSKI, M GESHKENBEIN, VB LARKIN, AI BURLACHKOV, L VINOKUR, VM CHIKUMOTO, N TI SURFACE CURRENTS AND BULK PINNING IN BI2CR2CACU2O8 SO PHYSICA C-SUPERCONDUCTIVITY AND ITS APPLICATIONS LA English DT Article; Proceedings Paper CT International Conference on Materials and Mechanisms of Superconductivity - High Temperature Superconductors IV (M2S-HTSC IV) CY JUL 05-09, 1994 CL GRENOBLE, FRANCE SP EUROPEAN COMMUNITY, MINIST EDUC & SCI, FRANCE, CNRS, FRENCH NATL CTR SCI RES, RHONE ALPES REG, CITY GRENOBLE AB The mechanisms giving rise to the irreversibility line (IL) in the phase diagram of Bi2Sr2CaCu2O8 and the mechanism behind the second maximum in the magnetization loops were determined using a novel Hall-sensor array. The IL is caused by bulk pinning at lower temperatures and by irreversible shielding currents above 22K. The second maximum is caused by vortex lattice melting, taking place at the same local magnetic induction B-m throughout the sample. C1 ECOLE POLYTECH,SOLIDES IRRADIES LAB,F-91128 PALAISEAU,FRANCE. LD LANDAU THEORET PHYS INST,MOSCOW 117940,RUSSIA. BAR ILAN UNIV,DEPT PHYS,IL-52900 RAMAT GAN,ISRAEL. ARGONNE NATL LAB,ARGONNE,IL 60439. UNIV TOKYO,BUNKYO KU,TOKYO 113,JAPAN. RP MAJER, D (reprint author), WEIZMANN INST SCI,IL-76100 REHOVOT,ISRAEL. RI Zeldov, Eli/K-1546-2012 OI Zeldov, Eli/0000-0002-8200-4974 NR 7 TC 17 Z9 18 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 DEC PY 1994 VL 235 BP 2765 EP 2766 DI 10.1016/0921-4534(94)92603-4 PN 4 PG 2 WC Physics, Applied SC Physics GA QC696 UT WOS:A1994QC69600308 ER PT J AU KISHIO, K SHIMOYAMA, J KIMURA, T KOTAKA, Y KITAZAWA, K YAMAFUJI, K LI, Q SUENAGA, M AF KISHIO, K SHIMOYAMA, J KIMURA, T KOTAKA, Y KITAZAWA, K YAMAFUJI, K LI, Q SUENAGA, M TI CARRIER DOPING AND INTERLAYER COUPLING IN HTSC SINGLE-CRYSTALS SO PHYSICA C-SUPERCONDUCTIVITY AND ITS APPLICATIONS LA English DT Article; Proceedings Paper CT International Conference on Materials and Mechanisms of Superconductivity - High Temperature Superconductors IV (M2S-HTSC IV) CY JUL 05-09, 1994 CL GRENOBLE, FRANCE SP EUROPEAN COMMUNITY, MINIST EDUC & SCI, FRANCE, CNRS, FRENCH NATL CTR SCI RES, RHONE ALPES REG, CITY GRENOBLE AB Experimental results of the effect of carrier doping on the irreversibility lines in (La,Sr)(2)CuO4-delta and Bi2Sr2CaCu2O8+delta Single crystals are summarized. As a function of Sr or oxygen contents, systematic and dramatic widening of the irreversible regions in the B - T phase diagram was observed in both systems. The present study suggests the critical importance of carrier concentration which directly affects the interlayer coupling strength and dimensionality of the flux line lattice in all the layered HTSC compounds as a universal feature. C1 KYUSHU UNIV,DEPT ELECTR,FUKUOKA 812,JAPAN. BROOKHAVEN NATL LAB,DIV MAT SCI,UPTON,NY 11973. RP KISHIO, K (reprint author), UNIV TOKYO,DEPT APPL CHEM,TOKYO 113,JAPAN. NR 6 TC 66 Z9 66 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 DEC PY 1994 VL 235 BP 2775 EP 2776 DI 10.1016/0921-4534(94)92608-5 PN 4 PG 2 WC Physics, Applied SC Physics GA QC696 UT WOS:A1994QC69600313 ER PT J AU BURLACHKOV, L GESHKENBEIN, VB KOSHELEV, AE LARKIN, AI VINOKUR, VM AF BURLACHKOV, L GESHKENBEIN, VB KOSHELEV, AE LARKIN, AI VINOKUR, VM TI GIANT FLUX-CREEP THROUGH THE SURFACE BARRIERS AND THE IRREVERSIBILITY LINE IN HIGH-T-C SUPERCONDUCTORS SO PHYSICA C-SUPERCONDUCTIVITY AND ITS APPLICATIONS LA English DT Article; Proceedings Paper CT International Conference on Materials and Mechanisms of Superconductivity - High Temperature Superconductors IV (M2S-HTSC IV) CY JUL 05-09, 1994 CL GRENOBLE, FRANCE SP EUROPEAN COMMUNITY, MINIST EDUC & SCI, FRANCE, CNRS, FRENCH NATL CTR SCI RES, RHONE ALPES REG, CITY GRENOBLE AB Magnetic flux relaxation over the surface barrier in high temperature superconductors ale investigated. Vortex dynamics controlled by the penetration both of pancake vortices and vortex lines are discussed. The penetration field H-p for pancakes decays exponentially with temperature. The size of the magnetization loop is determined by the decay of H-p during the process of relaxation, but its shape remains unchanged. The irreversibility line associated with the pancake penetration is given by H-irr proportional to exp(-2T/T-o), and may lie both above and below the melting line. C1 LD LANDAU THEORET PHYS INST,MOSCOW,RUSSIA. WEIZMANN INST SCI,IL-76100 REHOVOT,ISRAEL. ETH HONGGERBERG,ZURICH,SWITZERLAND. ARGONNE NATL LAB,ARGONNE,IL 60439. ISSP,CHERNOGOLOVKA,RUSSIA. RP BURLACHKOV, L (reprint author), BAR ILAN UNIV,RAMAT GAN,ISRAEL. RI Koshelev, Alexei/K-3971-2013 OI Koshelev, Alexei/0000-0002-1167-5906 NR 12 TC 0 Z9 0 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 DEC PY 1994 VL 235 BP 2783 EP 2784 DI 10.1016/0921-4534(94)92612-3 PN 4 PG 2 WC Physics, Applied SC Physics GA QC696 UT WOS:A1994QC69600317 ER PT J AU VANDERBEEK, CJ SCHMIDT, B KONCZYKOWSKI, M VINOKUR, VM CRABTREE, GW AF VANDERBEEK, CJ SCHMIDT, B KONCZYKOWSKI, M VINOKUR, VM CRABTREE, GW TI BOSE-GLASS VERSUS SURFACE-BARRIER CROSSOVER IN THE IRREVERSIBILITY LINE OF BI2SR2CACU2O8 SINGLE-CRYSTALS SO PHYSICA C-SUPERCONDUCTIVITY AND ITS APPLICATIONS LA English DT Article; Proceedings Paper CT International Conference on Materials and Mechanisms of Superconductivity - High Temperature Superconductors IV (M2S-HTSC IV) CY JUL 05-09, 1994 CL GRENOBLE, FRANCE SP EUROPEAN COMMUNITY, MINIST EDUC & SCI, FRANCE, CNRS, FRENCH NATL CTR SCI RES, RHONE ALPES REG, CITY GRENOBLE AB Frequency-dependent ac shielding measurements are used to elucidate the origin of magnetic irreversibility in heavy-ion irradiated Bi2Sr2CaCu2O8 single crystals. Whereas at intermediate static fields B < B-Phi, ac response is well described by Bose-glass dynamics, low field response is probably governed by a surface barrier. C1 ECOLE POLYTECH,SOLIDES IRRADIES LAB,F-91128 PALAISEAU,FRANCE. RP VANDERBEEK, CJ (reprint author), ARGONNE NATL LAB,DIV MAT SCI,9700 S CASS AVE,ARGONNE,IL 60489, USA. NR 3 TC 3 Z9 3 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 DEC PY 1994 VL 235 BP 2813 EP 2814 DI 10.1016/0921-4534(94)92627-1 PN 4 PG 2 WC Physics, Applied SC Physics GA QC696 UT WOS:A1994QC69600332 ER PT J AU VANDERBEEK, CJ SCHMIDT, B KONCZYKOWSKI, M VINOKUR, VM CRABTREE, GW AF VANDERBEEK, CJ SCHMIDT, B KONCZYKOWSKI, M VINOKUR, VM CRABTREE, GW TI VORTEX LINE PINNING IN BI2SR2CACU2O8 SINGLE-CRYSTALS WITH COLUMNAR DEFECTS SO PHYSICA C-SUPERCONDUCTIVITY AND ITS APPLICATIONS LA English DT Article; Proceedings Paper CT International Conference on Materials and Mechanisms of Superconductivity - High Temperature Superconductors IV (M2S-HTSC IV) CY JUL 05-09, 1994 CL GRENOBLE, FRANCE SP EUROPEAN COMMUNITY, MINIST EDUC & SCI, FRANCE, CNRS, FRENCH NATL CTR SCI RES, RHONE ALPES REG, CITY GRENOBLE AB The ac transmittivity of heavy-ion irradiated Bi2Sr2CaCu2O8 single crystals shows a sharp cusp as function of the de field orientation with respect to the columnar defects. This unambiguously demonstrates the connected nature of vortices in these samples. In contrast, the irreversibility line does not reveal a cusp. C1 ECOLE POLYTECH,SOLIDES IRRADIES LAB,F-91128 PALAISEAU,FRANCE. RP VANDERBEEK, CJ (reprint author), ARGONNE NATL LAB,DIV MAT SCI,9700 S CASS AVE,ARGONNE,IL 60489, USA. NR 5 TC 0 Z9 0 U1 0 U2 0 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0921-4534 J9 PHYSICA C JI Physica C PD DEC PY 1994 VL 235 BP 2815 EP 2816 DI 10.1016/0921-4534(94)92628-X PN 4 PG 2 WC Physics, Applied SC Physics GA QC696 UT WOS:A1994QC69600333 ER PT J AU Werner, M Sauerzopf, FM Weber, HW Veal, BD Licci, F Winzer, K Koblischka, MR AF Werner, M. Sauerzopf, F. M. Weber, H. W. Veal, B. D. Licci, F. Winzer, K. Koblischka, M. R. TI "Fishtails" in 123-superconductors SO PHYSICA C-SUPERCONDUCTIVITY AND ITS APPLICATIONS LA English DT Article AB Several high quality (RE)Ba2Cu3O7-x single crystals with RE = Y, Yb and Dy, with varying amounts of Au- and Al-impurities have been investigated by SQUID magnetometry. All samples show fishtail behavior. Differences in the sample preparation only influence the position of the maximum in J(c). We conclude from our results, that the fishtail phenomenon is not a material specific property, but a generally occurring property of the flux line lattice. C1 [Werner, M.; Sauerzopf, F. M.; Weber, H. W.] Osterreich Univ, Atominst, A-1020 Vienna, Austria. [Veal, B. D.] Argonne Natl Lab, Div Mat Sci, Argonne, IL 60439 USA. [Licci, F.] Maspec, I-43100 Parma, Italy. [Winzer, K.] Univ Gottingen, Inst Phys, D-37073 Gottingen, Germany. [Koblischka, M. R.] Free Univ Amsterdam, Dept Phys, NL-1081 HV Amsterdam, Netherlands. RP Werner, M (reprint author), Osterreich Univ, Atominst, A-1020 Vienna, Austria. RI Koblischka, Michael/C-3738-2011 FU Fonds zur Forderung der Wissenschaftlichen Forschung, Wien [9194] FX This work was supported in part by Fonds zur Forderung der Wissenschaftlichen Forschung, Wien, under contract No. 9194. NR 6 TC 23 Z9 23 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 DEC PY 1994 VL 235-40 BP 2833 EP 2834 DI 10.1016/0921-4534(94)90943-1 PN 5 PG 2 WC Physics, Applied SC Physics GA V23ZX UT WOS:000208381800009 ER PT J AU Konczykowski, M Chikumoto, N Vinokur, V Feigelman, M AF Konczykowski, M. Chikumoto, N. Vinokur, V. Feigelman, M. TI Relaxing magnetic hysteresis loop: the measurement of the critical current or of the divergence of flux creep barrier? SO PHYSICA C-SUPERCONDUCTIVITY AND ITS APPLICATIONS LA English DT Article AB The new type of measurement: time resolved magnetic hysteresis loop performed on Bi2Sr2CaCu2O8 crystals containing columnar defects indicates that the change in the relaxation dynamics is the origin of anomalous double-peak magnetization loops. C1 [Konczykowski, M.; Chikumoto, N.] Ecole Polytech, Solides Irradies Lab, CEA, F-91128 Palaiseau, France. [Chikumoto, N.] Univ Tokyo, Bunkyo Ku, Tokyo 113, Japan. [Vinokur, V.] Argonne Natl Lab, Argonne, IL 60439 USA. [Feigelman, M.] LD Landau Theoret Phys Inst, Moscow 117940, Russia. RP Konczykowski, M (reprint author), Ecole Polytech, Solides Irradies Lab, CEA, F-91128 Palaiseau, France. RI Feigelman, Mikhail/M-4113-2013 FU U.S. Department of Energy, BES-Materials Sciences [W-31-109-ENG-38] FX VMV acknowledges the support through U.S. Department of Energy, BES-Materials Sciences, under contract #W-31-109-ENG-38. NR 5 TC 2 Z9 2 U1 1 U2 1 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0921-4534 J9 PHYSICA C JI Physica C PD DEC PY 1994 VL 235-40 BP 2845 EP 2846 DI 10.1016/0921-4534(94)90949-0 PN 5 PG 2 WC Physics, Applied SC Physics GA V23ZX UT WOS:000208381800015 ER PT J AU Gilchrist, J van der Beek, CJ AF Gilchrist, J. van der Beek, C. J. TI Power-law resistivity, magnetic relaxation and ac susceptibility SO PHYSICA C-SUPERCONDUCTIVITY AND ITS APPLICATIONS LA English DT Article AB The nonlinear diffusion of magnetic flux into a superconducting sample can be studied by measuring the relaxation of the magnetisation after application of a step field or by measuring the ac susceptibility, chi(1) and its third harmonic, chi(3), or preferably both methods covering different time scales. Each has been analysed recently for a field-cooled sample of a material whose creep activation energy depends logarithmically on current density, J corresponding to a power-law relation between electric field, E and J. Here, results are compared, using a universal scaling depth. Maximum chi(1)" and vertical bar chi(3)vertical bar values occur, and also the magnetisation has relaxed to half its initial value when the scaling depth is comparable to the sample half-thickness. C1 [Gilchrist, J.] Univ Grenoble 1, CNRS, Ctr Rech Tres Basses Temp, Lab Associe, F-38042 Grenoble 9, France. [van der Beek, C. J.] Argonne Natl Lab, Div Mat Sci, Argonne, IL 60439 USA. RP Gilchrist, J (reprint author), Univ Grenoble 1, CNRS, Ctr Rech Tres Basses Temp, Lab Associe, BP 166, F-38042 Grenoble 9, France. NR 6 TC 0 Z9 0 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 DEC PY 1994 VL 235-40 BP 2847 EP 2848 DI 10.1016/0921-4534(94)90950-4 PN 5 PG 2 WC Physics, Applied SC Physics GA V23ZX UT WOS:000208381800016 ER PT J AU Vlasko-Vlasov, VK Nikitenko, VI Polyanskii, AA Crabtree, GW Welp, U Veal, BW AF Vlasko-Vlasov, V. K. Nikitenko, V. I. Polyanskii, A. A. Crabtree, G. W. Welp, U. Veal, B. W. TI Macroturbulence in Superconductors SO PHYSICA C-SUPERCONDUCTIVITY AND ITS APPLICATIONS LA English DT Article AB Direct magneto-optic observation of coupling of the Abrikosov vortices into macroscopic drops of increased flux density at remagnetization of the YBCO single crystals is presented. Appearance of these flux structures correspond to strong perturbations of the current trajectories and transition from laminar to turbulent current flow. C1 [Vlasko-Vlasov, V. K.; Nikitenko, V. I.; Polyanskii, A. A.] Russian Acad Sci, Inst Solid State Phys, Chernogolovka 142432, Moscow Distr, Russia. [Crabtree, G. W.; Welp, U.; Veal, B. W.] Argonne Natl Lab, Argonne, IL 60439 USA. RP Vlasko-Vlasov, VK (reprint author), Russian Acad Sci, Inst Solid State Phys, Chernogolovka 142432, Moscow Distr, Russia. FU Soros Foundation; NSF Office of Science and Technology Center [DMR 91-20000]; US DOE, Basic Energy Sciences-Material Sciences [W-31-10-ENG-38] FX The work was supported by the Soros Foundation, NSF Office of Science and Technology Center (contract No. DMR 91-20000), and US DOE, Basic Energy Sciences-Material Sciences (contract No. W-31-10-ENG-38). NR 6 TC 0 Z9 0 U1 0 U2 2 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0921-4534 J9 PHYSICA C JI Physica C PD DEC PY 1994 VL 235-40 BP 2857 EP 2858 DI 10.1016/0921-4534(94)90955-5 PN 5 PG 2 WC Physics, Applied SC Physics GA V23ZX UT WOS:000208381800021 ER PT J AU Konczykowski, M Majer, D Zeldov, E Chikumoto, N Vinokur, VM AF Konczykowski, M. Majer, D. Zeldov, E. Chikumoto, N. Vinokur, V. M. TI Flux profiles in Bi2Sr2CaCu2O8 crystals containing columnar defects SO PHYSICA C-SUPERCONDUCTIVITY AND ITS APPLICATIONS LA English DT Article AB The magnetic flux profiles in Bi2Sr2CaCu2O8 crystals containing columnar defects were measured using a Hall-sensor array placed on the sample surface. Double slope profiles with abrupt drop of persistent current J approximate to dB/dx above the matching field B-Phi were observed, in agreement with the predictions of the Bose-glass model (B-Phi is the field of complete filling of columnar defects by flux lines). Disapearence of this feature at 50-60K can be identified as crossing the depinning temperature T-dp. C1 [Konczykowski, M.; Chikumoto, N.] Ecole Polytech, Solides Irradies Lab, CEA, F-91128 Palaiseau, France. [Majer, D.; Zeldov, E.] Weizmann Inst Sci, IL-76100 Rehovot, Israel. [Chikumoto, N.] Univ Tokyo, Bunkyo Ku, Tokyo 113, Japan. [Vinokur, V. M.] Argonne Natl Lab, Argonne, IL 60439 USA. RP Konczykowski, M (reprint author), Ecole Polytech, Solides Irradies Lab, CEA, F-91128 Palaiseau, France. RI Zeldov, Eli/K-1546-2012 OI Zeldov, Eli/0000-0002-8200-4974 FU Israeli Ministery of Sciences; France-Israel cooperation fund [PICS-112]; U.S. Department of Energy, BES-Materials Sciences [W-31-109-ENG-38] FX This work was supported by the Israeli Ministery of Sciences and by France-Israel cooperation fund PICS-112. VMV acknowledges the support through U.S. Department of Energy, BES-Materials Sciences, under contract #W-31-109-ENG-38 NR 3 TC 4 Z9 4 U1 0 U2 2 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0921-4534 J9 PHYSICA C JI Physica C PD DEC PY 1994 VL 235-40 BP 2965 EP 2966 DI 10.1016/0921-4534(94)91009-X PN 5 PG 2 WC Physics, Applied SC Physics GA V23ZX UT WOS:000208381800075 ER PT J AU Hwa, T Le Doussal, P Nelson, DR Vinokur, V AF Hwa, T. Le Doussal, P. Nelson, D. R. Vinokur, V. TI Flux Pinning and Forced Entanglement by Splayed Columnar Defects SO PHYSICA C-SUPERCONDUCTIVITY AND ITS APPLICATIONS LA English DT Article AB We propose controlled splay of artificial columnar defects in cuprate superconductors as a strategy to enhance transport properties in a field compared to parallel columns. The theory predicts a new "splayed glass" phase with a greatly reduced flux creep, an entangled ground state, and very slow response to a transverse field. C1 [Hwa, T.] Inst Adv Study, Princeton, NJ 08540 USA. [Le Doussal, P.] Rutgers State Univ, Serin Phys Lab, Piscataway, NJ 08855 USA. [Nelson, D. R.] Harvard Univ, Lyman Lab Phys, Cambridge, MA 02138 USA. [Vinokur, V.] Argonne Natl Lab, Div Mat Sci, Argonne, IL 60439 USA. RP Hwa, T (reprint author), Inst Adv Study, Olden Lane, Princeton, NJ 08540 USA. RI Hwa, Terence/J-4012-2013 OI Hwa, Terence/0000-0003-1837-6842 FU Argonne National Laboratory U.S. DOE, BES-Material Sciences [W-31-109-ENG-38]; NSF [DMR-91-15491, DMR-91-06237, DMR-91-07752] FX Supported by Argonne National Laboratory U.S. DOE, BES-Material Sciences, contract No. W-31-109-ENG-38.; Research supported in part by NSF Grants No. DMR-91-15491,06237,07752. NR 5 TC 2 Z9 2 U1 1 U2 4 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0921-4534 J9 PHYSICA C JI Physica C PD DEC PY 1994 VL 235-40 BP 2967 EP 2968 DI 10.1016/0921-4534(94)91010-3 PN 5 PG 2 WC Physics, Applied SC Physics GA V23ZX UT WOS:000208381800076 ER PT J AU Civale, L Krusin-Elbaum, L Thompson, JR Wheeler, R Kirk, MA Feild, C AF Civale, L. Krusin-Elbaum, L. Thompson, J. R. Wheeler, R. Kirk, M. A. Feild, C. TI Arresting of vortex motion in YBaCuO crystals with splay in columnar defects SO PHYSICA C-SUPERCONDUCTIVITY AND ITS APPLICATIONS LA English DT Article AB We show that at high temperatures, the columnar defects generated in YBaCuO crystals by 0.58 GeV Sn-116(30+) have a natural splay of similar to 10 degrees and produce a 10 times larger persistent current density end a 10 times smaller creep rate, than well aligned tracks created by 1.08 GeV Sn-197(23+), with splay of only similar to 2 degrees. C1 [Civale, L.] Ctr Atom Bariloche, RA-8400 San Carlos De Bariloche, Rio Negro, Argentina. [Krusin-Elbaum, L.; Feild, C.] IBM Corp, Thomas J Watson Res Ctr, Yorktown Hts, NY 10598 USA. [Thompson, J. R.] Oak Ridge Natl Lab, Oak Ridge, TN 37831 USA. [Wheeler, R.; Kirk, M. A.] Argonne Natl Lab, Argonne, IL 60439 USA. RP Civale, L (reprint author), Ctr Atom Bariloche, RA-8400 San Carlos De Bariloche, Rio Negro, Argentina. NR 5 TC 5 Z9 5 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 DEC PY 1994 VL 235-40 BP 2969 EP 2970 DI 10.1016/0921-4534(94)91011-1 PN 5 PG 2 WC Physics, Applied SC Physics GA V23ZX UT WOS:000208381800077 ER PT J AU Burlachkov, L Vinokur, VM AF Burlachkov, L. Vinokur, V. M. TI Surface Critical Currents and Activation Energies in high-temperature superconductors SO PHYSICA C-SUPERCONDUCTIVITY AND ITS APPLICATIONS LA English DT Article AB The critical currents and activation energies related to the surface (Bean-Livingston) barrier are found for high-temperature superconductors. It is shown that the surface barrier does not undergo a temperature (exponential) suppression which is typical of the bulk pinning. Therefore the surface irreversibility dominates over the bulk one at high temperatures T similar or equal to T-c, where the bulk pinning is suppressed by thermal fluctuations. The dependencies of the surface activation energies U-surf on the external field (U-surf proportional to H-1/2) and transport current (U-surf proportional to J(-1/2) for moderate currents) prove to be different from those for U-bulk. This helps to distinguish between the surface and bulk effects on the transport and magnetization properties of HTSC. The interplay between the surface and the bulk contributions is discussed. C1 [Burlachkov, L.] Bar Ilan Univ, Jack & Peal Resnick Inst Adv Technol, IL-52900 Ramat Gan, Israel. [Burlachkov, L.] Bar Ilan Univ, Dept Phys, IL-52900 Ramat Gan, Israel. [Vinokur, V. M.] Argonne Natl Lab, Div Mat Sci, Argonne, IL 60439 USA. RP Burlachkov, L (reprint author), Bar Ilan Univ, Jack & Peal Resnick Inst Adv Technol, IL-52900 Ramat Gan, Israel. FU Raschi Foundation; Israel Academy of Science; Argonne National Laboratory through U.S. Department of Energy, BES-Materials Sciences [W-31-109-ENG-38] FX L.B. is grateful to the support from the Raschi Foundation and the Israel Academy of Science. V. M. V. acknowledges the support from the Argonne National Laboratory through U.S. Department of Energy, BES-Materials Sciences, under contract No. W-31-109-ENG-38. NR 8 TC 2 Z9 2 U1 0 U2 2 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0921-4534 J9 PHYSICA C JI Physica C PD DEC PY 1994 VL 235-40 BP 2993 EP 2994 DI 10.1016/0921-4534(94)91023-5 PN 5 PG 2 WC Physics, Applied SC Physics GA V23ZX UT WOS:000208381800089 ER PT J AU Almasan, CC Han, SH Yoshiara, K Buchgeister, M Gajewski, DA Herrmann, J Paulikas, AP Gu, C Veal, BW Maple, MB AF Almasan, C. C. Han, S. H. Yoshiara, K. Buchgeister, M. Gajewski, D. A. Herrmann, J. Paulikas, A. P. Gu, Chun Veal, B. W. Maple, M. B. TI Hall effect studies of the mixed and normal states of Y1-xPrxBa2Cu3O7-delta (0 <= x <= 1) and YBa2Cu3Oy (6.35 <= y <= 7) single crystals SO PHYSICA C-SUPERCONDUCTIVITY AND ITS APPLICATIONS LA English DT Article AB Hall effect measurements on single crystal specimens of Y1-xPrxBa2Cu3O7-delta (0 <= x <= 1) and YBa2Cu3Oy (6.35 <= y <= 7) revealed a "negative Hall anomaly" below T-c, in the mixed state. For both systems, the depth Delta of the negative Hall signal scales with T/T-c, while the maximum value of Delta decreases monotonically with decreasing T-c and vanishes at T-c approximate to 68 K. These results show that the sign anomaly is not consistent with models that invoke pinning to explain this effect, and suggest that the negative anomaly could have an intrinsic origin. Hall effect measurements in the normal state of both systems show that the cotangent of the Hall angle can be described by cot Theta(H) = AT(2) + B, where A increases linearly with decreasing T-c for both systems, while B increases linearly with decreasing T-c for Y1-xPrxBa2Cu3O7-delta and is constant within experimental error for YBa2Cu3Oy. C1 [Almasan, C. C.; Han, S. H.; Yoshiara, K.; Buchgeister, M.; Gajewski, D. A.; Herrmann, J.; Maple, M. B.] Univ Calif San Diego, Dept Phys, La Jolla, CA 92093 USA. [Almasan, C. C.; Han, S. H.; Yoshiara, K.; Buchgeister, M.; Gajewski, D. A.; Herrmann, J.; Maple, M. B.] Univ Calif San Diego, Inst Pure & Appl Phys Sci, La Jolla, CA 92093 USA. [Yoshiara, K.] Mitsubishi Elect Corp, Mat & Elect Devices Lab, Sagamihara, Kanagawa, Japan. [Paulikas, A. P.; Gu, Chun; Veal, B. W.] Argonne Natl Lab, Argonne, IL 60439 USA. RP Almasan, CC (reprint author), Univ Calif San Diego, Dept Phys, La Jolla, CA 92093 USA. FU U. S. Department of Energy [DE-FG03-86ER-45230]; Alexander-von Humboldt Foundation; German Academic Exchange Service FX This research was supported by the U. S. Department of Energy under Grant No. DE-FG03-86ER-45230. MB acknowledges partial support from the Alexander-von Humboldt Foundation; JH acknowledges support from the German Academic Exchange Service. NR 8 TC 0 Z9 0 U1 0 U2 0 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0921-4534 J9 PHYSICA C JI Physica C PD DEC PY 1994 VL 235-40 BP 3119 EP 3120 DI 10.1016/0921-4534(94)91086-3 PN 5 PG 2 WC Physics, Applied SC Physics GA V23ZX UT WOS:000208381800152 ER PT J AU Feigel'man, MV Geshkenbein, VB Larkin, AI Vinokur, VM AF Feigel'man, M. V. Geshkenbein, V. B. Larkin, A. I. Vinokur, V. M. TI Sign Change of the Flux Flow Hall Effect in HTSC SO PHYSICA C-SUPERCONDUCTIVITY AND ITS APPLICATIONS LA English DT Article AB A novel mechanism for the sign change of the Hall effect in flux flow region is proposed. The difference delta n between the electron density at the center of the vortex core and that far outside the vortex causes the additional contribution to the Hall conductivity delta sigma(xy) = -delta nec/B. This contribution can be bigger than the conventional one in the dirty case Delta(T)tau < 1. If the electron density inside the core exceeds the electron density outside the core the double sign change may occur as a function of temperature and magnetic field. C1 [Feigel'man, M. V.; Geshkenbein, V. B.; Larkin, A. I.] LD Landau Theoret Phys Inst, Moscow 117940, Russia. [Geshkenbein, V. B.; Larkin, A. I.] Weizmann Inst Sci, IL-76100 Rehovot, Israel. [Geshkenbein, V. B.; Larkin, A. I.] ETH Honggerberg, CH-8093 Zurich, Switzerland. [Vinokur, V. M.] Argonne Natl Lab, Argonne, IL 60439 USA. RP Feigel'man, MV (reprint author), LD Landau Theoret Phys Inst, Kosygina 2, Moscow 117940, Russia. RI Feigelman, Mikhail/M-4113-2013 FU Swiss National Foundation; Landau Weizmann program for Theoretical Physics; US Department of Energy BES-Materials Sciences [W-31-109-ENG-38] FX MVF, VBG and AIL acknowledge support from the Swiss National Foundation and the Landau Weizmann program for Theoretical Physics. VMV acknowledges the support through US Department of Energy BES-Materials Sciences, under contract No. W-31-109-ENG-38. NR 11 TC 25 Z9 25 U1 0 U2 2 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 DEC PY 1994 VL 235-40 BP 3127 EP 3128 DI 10.1016/0921-4534(94)91090-1 PN 5 PG 2 WC Physics, Applied SC Physics GA V23ZX UT WOS:000208381800156 ER PT J AU Dominguez, D Jagla, EA Balseiro, CA AF Dominguez, D. Jagla, E. A. Balseiro, C. A. TI Wohlleben Effect in a model granular High TC Superconductor SO PHYSICA C-SUPERCONDUCTIVITY AND ITS APPLICATIONS LA English DT Article AB We discuss a phenomenological model for granular Bi-2212 superconductors which consists of a network of Josephson junctions with a random distribution of pi-junctions. We calculate the field cooling and zero field cooling susceptibility using dinamical Langevin simulations. We obtain a paramagnetic response for the field cooling susceptibility and an anomalous microwave absorption in agreement with recent experimental results C1 [Dominguez, D.] Univ Calif Los Alamos Natl Lab, Los Alamos, NM 87545 USA. [Jagla, E. A.; Balseiro, C. A.] Ctr Atom Bariloche, RA-8400 San Carlos De Bariloche, Rio Negro, Argentina. [Jagla, E. A.; Balseiro, C. A.] Inst Balseiro, RA-8400 San Carlos De Bariloche, Rio Negro, Argentina. RP Dominguez, D (reprint author), Univ Calif Los Alamos Natl Lab, MS B262, Los Alamos, NM 87545 USA. RI Dominguez, Daniel/E-9304-2016 OI Dominguez, Daniel/0000-0002-6204-0150 FU CONICET FX EAJ and CAB acknowledge finantial support by CONICET. NR 5 TC 6 Z9 6 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 DEC PY 1994 VL 235-40 BP 3283 EP 3284 DI 10.1016/0921-4534(94)91168-1 PN 5 PG 2 WC Physics, Applied SC Physics GA V23ZX UT WOS:000208381800234 ER EF