FN Thomson Reuters Web of Science™ VR 1.0 PT J AU ZIEGLER, CL MACGORMAN, DR DYE, JE RAY, PS AF ZIEGLER, CL MACGORMAN, DR DYE, JE RAY, PS TI A MODEL EVALUATION OF NONINDUCTIVE GRAUPEL-ICE CHARGING IN THE EARLY ELECTRIFICATION OF A MOUNTAIN THUNDERSTORM SO JOURNAL OF GEOPHYSICAL RESEARCH-ATMOSPHERES LA English DT Article ID OBSERVED CONVECTIVE STORMS; ELECTRIC-FIELD GROWTH; PRECIPITATION DEVELOPMENT; MICROPHYSICAL VARIABLES; MEXICO THUNDERSTORMS; CRYSTAL INTERACTIONS; SEPARATION; PARTICLES; RETRIEVAL; HAIL AB The role of noninductive graupel-ice charge separation in the early electrification of the July 31, 1984, New Mexico mountain thunderstorm is assessed with a three-dimensional kinematic cloud model along with multiple Doppler radar and in situ measurements. Observations of the early electrification rate and the electric field distribution are consistent with modeled values that result when the noninductive mechanism works under the influence of convective motions and precipitation growth. An increase in ice particle concentrations and sizes, arising from vigorous precipitation growth, accelerates graupel-ice collision rates and hence the noninductive charging rate. Growing graupel particles experience increasing fall speed as they rise toward the top of the updraft. The resulting vertical flux convergence of graupel containing charge from previous noninductive collisions is a significant factor in the growth of the main negative charge density. This implies that a combination of air motion, precipitation interaction, and sedimentation contributes to the rapid intensification of storm electric fields. The linear electrification phase, which begins with the cessation of convective growth, is caused by a roughly constant noninductive charging rate and by the separation of negatively charged graupel and positively charged smaller ice particles by differential sedimentation, downdrafts, and horizontal advection in vertically sheared flow. When the sign reversal temperature for noninductive charging is assumed to be -10-degrees-C, the model results are characterized by a main negative charge in middle levels and provide the best overall agreement with the in situ field measurements in the July 31 storm. For a sign reversal temperature of -21-degrees-C the model results are characterized by a main positive charge center in middle levels, and the electric field polarity is opposite to the polarity measured at low and middle levels of the storm. The model and observational data, combined with findings of some laboratory studies, support the hypothesis that the actual reversal temperature in the July 31 storm is around -10-degrees-C. When the model includes the inductive graupel-droplet charging mechanism in addition to the noninductive mechanism, the effect of inductive charging is secondary to that of noninductive charging. The net effect of adding induction is dissipative. For example, the maximum field strength at the location of the aircraft measurements is slightly less than in the case where the noninductive mechanism acts alone. Weak charge screening layers were found to develop on the boundary of the modeled cloud. C1 FLORIDA STATE UNIV, SUPERCOMP COMPUTAT RES INST, TALLAHASSEE, FL 32306 USA. NATL CTR ATMOSPHER RES, BOULDER, CO 80307 USA. FLORIDA STATE UNIV, DEPT METEOROL, TALLAHASSEE, FL 32306 USA. RP ZIEGLER, CL (reprint author), NATL SEVERE STORMS LAB, 1313 HALLEY CIRCLE, NORMAN, OK 73069 USA. OI MacGorman, Donald/0000-0002-2395-8196 NR 39 TC 72 Z9 94 U1 2 U2 8 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 JUL 20 PY 1991 VL 96 IS D7 BP 12833 EP 12855 DI 10.1029/91JD01246 PG 23 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA FY191 UT WOS:A1991FY19100001 ER PT J AU BRAUN, W FAHR, A KLEIN, R KURYLO, MJ HUIE, RE AF BRAUN, W FAHR, A KLEIN, R KURYLO, MJ HUIE, RE TI UV GAS AND LIQUID-PHASE ABSORPTION CROSS-SECTION MEASUREMENTS OF HYDROCHLOROFLUOROCARBONS HCFC-225CA AND HCFC-225CB SO JOURNAL OF GEOPHYSICAL RESEARCH-ATMOSPHERES LA English DT Article ID ULTRAVIOLET-ABSORPTION; METHANES AB The environmental effect of chlorofluorocarbon (CFC) replacement compounds such as the hydrochlorofluorocarbons (HCFCs) requires accurate data for gas phase absorption cross sections. Such data are particularly important in the near uv wavelength region where the cross sections are often very low. Measurements of such low cross-sections are difficult and unreliable. In the present work we have found that absorption cross sections derived from measurements in the liquid phase for two HCFCs, 1,1,1,2,2- pentafluoro-3,3-dichloropropane (HCFC-225ca) and 1,1,2,2,3- pentafluoro-1,3-dichloropropane (HCFC-225cb) can, with appropriate correction factors, be converted into accurate gas phase values. The method itself has a basis in theoretical treatments which relate liquid to gas phase absorption cross section conversions. Thus a reliable experimental technique is available for determining gas phase absorption cross sections of diffuse absorbers in regions of very low absorptions. The method minimizes some of the systematic errors that accompany the measurement of extremely low gas phase absorbitivity in the ultraviolet and can potentially cover a wide range of temperature. RP BRAUN, W (reprint author), NATL INST STAND & TECHNOL, DIV CHEM KINET, GAITHERSBURG, MD 20899 USA. RI Huie, Robert/A-5645-2010; Kurylo, Michael/H-2201-2012 NR 19 TC 11 Z9 11 U1 0 U2 1 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 2169-897X J9 J GEOPHYS RES-ATMOS JI J. Geophys. Res.-Atmos. PD JUL 20 PY 1991 VL 96 IS D7 BP 13009 EP 13015 DI 10.1029/91JD01026 PG 7 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA FY191 UT WOS:A1991FY19100013 ER PT J AU NOVELLI, PC ELKINS, JW STEELE, LP AF NOVELLI, PC ELKINS, JW STEELE, LP TI THE DEVELOPMENT AND EVALUATION OF A GRAVIMETRIC REFERENCE SCALE FOR MEASUREMENTS OF ATMOSPHERIC CARBON-MONOXIDE SO JOURNAL OF GEOPHYSICAL RESEARCH-ATMOSPHERES LA English DT Article ID SOUTHERN-HEMISPHERE; EARTHS ATMOSPHERE; CO; METHANE; TRENDS; CH4; ABUNDANCE; INCREASE AB We have prepared a set of 17 carbon monoxide (CO) reference mixtures for use in the calibration of measurements of atmospheric concentrations of this gas. The mixing ratios of these standards range from 25 to 1003 ppb (parts per billion by mole fraction) in zero natural air and are contained in 5.9-L, high-pressure aluminum cylinders. Carbon monoxide was measured using gas chromatography with a mercuric oxide detector. The concentration range of the standards is sufficient to cover that of the background troposphere and also that found in remote locations affected by anthropogenic activities. The low concentration standards were prepared by gravimetric methods using one of three high concentration standards as the parent. Two of the parents were prepared by gravimetric methods starting from high-purity (99.97%) CO to have concentrations of about 250 ppm (parts per million) CO. A total of 14 atmospheric level primary standards were prepared from these two parents. The third parent was a NIST SRM (National Institute of Standards and Technology, Standard Reference Material) having 9.7 ppm CO, from which three standards were prepared. Monitoring of CO levels in the primary standards, relative to natural air contained in 29.5-L high-pressure aluminum cylinders, suggests that the CO content of some primaries may be increasing at rates of between 1 and 2 ppb yr-1. The CO concentration scale defined by the gravimetric standards was used to calibrate a set of 10 secondary standards. The secondary standards are all contained in 29.5-L high-pressure aluminum cylinders and range in concentration from 35 to 200 ppb. Examination of the CO content in several of the oldest secondary standards indicates their CO concentrations have not changed relative to each other over the 2 years they have been studied. Comparison of the low concentration standards derived from the gravimetric parents to those prepared from the NIST SRM show no difference to within 1% between the two scales. We also compared our standards to commercially available, NIST-traceable, CO standards (approximately 0.5 and 1 ppm of CO in air). The concentrations assigned these standards by the manufacturer agreed to within 3% of concentrations we calculated referenced to our standard scale. In addition, we compared our concentration scale to a CO standard used at the Commonwealth Scientific and Industrial Research Organization (CSIRO), Australia. Intercomparison of a cylinder of natural air between our laboratory and CSIRO (which used a CO reference gas traceable to the standards of the Oregon Graduate Institute for Science and Technology, formerly the Oregon Graduate Center) indicated that the CO concentration determined for this air based upon our reference scale was approximately 25% greater than the concentration determined by CSIRO. Carbon monoxide concentrations determined in flask samples collected at Mauna Loa, Hawaii, referenced to this concentration scale, are compared to the earlier reports of CO levels at this location by Seiler et al. C1 NOAA, CLIMATE MONITORING & DIAGNOST LAB, BOULDER, CO 80303 USA. RP NOVELLI, PC (reprint author), UNIV COLORADO, NOAA, COOPERAT INST RES ENVIRONM SCI, CAMPUS BOX 449, BOULDER, CO 80309 USA. RI Steele, Paul/B-3185-2009 OI Steele, Paul/0000-0002-8234-3730 NR 35 TC 71 Z9 73 U1 0 U2 13 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 JUL 20 PY 1991 VL 96 IS D7 BP 13109 EP 13121 DI 10.1029/91JD01108 PG 13 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA FY191 UT WOS:A1991FY19100019 ER PT J AU SNAY, RA MATSIKARI, T AF SNAY, RA MATSIKARI, T TI HORIZONTAL DEFORMATION IN THE CASCADIA SUBDUCTION ZONE AS DERIVED FROM SERENDIPITOUS GEODETIC DATA SO TECTONOPHYSICS LA English DT Article ID WASHINGTON AB Data from recent Global Positioning System (GPS) surveys are combined with triangulation/trilateration data to estimate horizontal shear-strain rates for two regions in the Cascadia subduction zone. Near Bellingham, Washington, we estimate that the maximum horizontal shear rate (gamma) equals 0.116 +/- 0.089-mu-rad/yr and the direction of maximum horizontal contraction (theta) orients N71-degrees-E +/- 21-degrees for data spanning the 1905-1985 interval. The corresponding estimates for a region near Portland, Oregon, are 0.057 +/- 0.027-mu-rad/yr and N95-degrees-E +/- 14-degrees for data spanning the 1881-1988 interval. These estimates are consistent with estimates from independent geodetic data in the area. Moreover, the estimates for theta are consistent with the N68-degrees-E direction of ongoing convergence between the Juan de Fuca plate and the North American plate as predicted by the NUVEL-1 plate motion model. This consistency between theta-estimates and the direction of plate convergence supports the argument for the possibility of a great subduction earthquake occurring in the Cascadia subduction zone. The low shear rates, however, imply that the recurrence interval between such earthquakes would be several centuries long. C1 NATL TECH UNIV ATHENS,ZOGRAFOS,GREECE. RP SNAY, RA (reprint author), NOAA,NATL OCEAN SERV,CHARING & GEODET SERV,NATL GEODET SURVEY,ROCKVILLE,MD 20852, USA. NR 17 TC 9 Z9 9 U1 0 U2 2 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0040-1951 J9 TECTONOPHYSICS JI Tectonophysics PD JUL 20 PY 1991 VL 194 IS 1-2 BP 59 EP 67 DI 10.1016/0040-1951(91)90272-T PG 9 WC Geochemistry & Geophysics SC Geochemistry & Geophysics GA FY746 UT WOS:A1991FY74600005 ER PT J AU TAATJES, CA LOVEJOY, CM OPANSKY, BJ LEONE, SR AF TAATJES, CA LOVEJOY, CM OPANSKY, BJ LEONE, SR TI LASER DOUBLE-RESONANCE MEASUREMENTS OF THE QUENCHING RATES OF BR(2P1/2) WITH H2O, D2O, HDO, AND O2 SO CHEMICAL PHYSICS LETTERS LA English DT Article ID VIBRATIONAL ENERGY-TRANSFER; DEACTIVATION; BR(42P1/2); ATOMS; KINETICS; BR2 AB Quenching rate constants for spin-orbit excited Br* atoms (2P1/2) with H2O, D2O, HDO. and O2 are measured at 300 K using a two-laser pump-probe technique. The rate constants and +/- 1 sigma-error bars for the water species are: H2O, (5.1 +/- 0.3) x 10(-11) cm3 molecule-1 s-1; HDO, (1.9 +/- 0.4) x 10(-11) cm3 molecule-1 s-1; D2O, (2.2 +/- 0.4) x 10(-12) cm3 molecule-1 s-1. The relative rates for the water species are in qualitative agreement with models for electronic-to-vibrational energy transfer based upon dipole-quadrupole coupling. Quenching of Br* by oxygen is found to be extremely inefficient (1.5(-1.5)+0.4) x 10(-15) cm3 molecule-1 s-1. which is in disagreement with previously reported results by four orders of magnitude. C1 UNIV COLORADO,DEPT CHEM & BIOCHEM,BOULDER,CO 80309. UNIV COLORADO,NATL INST STAND & TECHNOL,JOINT INST LAB ASTROPHYS,BOULDER,CO 80309. NR 21 TC 8 Z9 8 U1 0 U2 0 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0009-2614 J9 CHEM PHYS LETT JI Chem. Phys. Lett. PD JUL 19 PY 1991 VL 182 IS 1 BP 39 EP 44 DI 10.1016/0009-2614(91)80100-C PG 6 WC Chemistry, Physical; Physics, Atomic, Molecular & Chemical SC Chemistry; Physics GA FX956 UT WOS:A1991FX95600008 ER PT J AU BROWNTHOMAS, JM CHRISTENSEN, RG RIEGER, R MALONE, W MAY, WE AF BROWNTHOMAS, JM CHRISTENSEN, RG RIEGER, R MALONE, W MAY, WE TI DETERMINATION OF GLYCYRRHETINIC ACID IN HUMAN PLASMA BY HIGH-PERFORMANCE LIQUID-CHROMATOGRAPHY SO JOURNAL OF CHROMATOGRAPHY-BIOMEDICAL APPLICATIONS LA English DT Note ID GLYCYRRHIZIN AB A high-performance liquid chromatographic (HPLC) method has been developed for measuring 18-beta-glycyrrhetinic acid (GRA) in human plasma in the range of 0.1-3-mu-g/ml. The acetate ester of GRA is added to the plasma as an internal standard, plasma proteins are denatured with urea to release GRA, and the GRA and the internal standard are extracted in an ion-pairing solid-phase extraction process. An isocratic, reversed-phase HPLC separation is used, followed by ultraviolet absorbance detection at 248 nm. The results from the analysis of five GRA-fortified plasma pools show a mean relative standard deviation of 7% and are accurate to within 10%. With evaporative concentration of the extract, the limit of detection for GRA in plasma is approximately 10 ng/ml. RP BROWNTHOMAS, JM (reprint author), NATL INST STAND & TECHNOL,CTR ANALYT CHEM,DIV ORGAN ANALYT RES,GAITHERSBURG,MD 20899, USA. FU NCI NIH HHS [Y01-CN-80655] NR 15 TC 15 Z9 15 U1 0 U2 0 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0378-4347 J9 J CHROMATOGR-BIOMED JI J. Chromatogr.-Biomed. Appl. PD JUL 17 PY 1991 VL 568 IS 1 BP 232 EP 238 DI 10.1016/0378-4347(91)80358-J PG 7 WC Chemistry, Analytical SC Chemistry GA FZ164 UT WOS:A1991FZ16400024 PM 1770101 ER PT J AU EKIN, JW SALAMA, K SELVAMANICKAM, V AF EKIN, JW SALAMA, K SELVAMANICKAM, V TI HIGH-TRANSPORT CURRENT-DENSITY UP TO 30-T IN BULK YBA2CU3O7 AND THE CRITICAL ANGLE EFFECT SO APPLIED PHYSICS LETTERS LA English DT Article ID BA-CU-O; TC OXIDE SUPERCONDUCTORS; FLUX CREEP; CRYSTAL AB Measurements of the dc transport critical current of oriented-grained YBa2Cu3O7 have been made using high quality Ag contacts and a high-current sample mount. The critical-current density J(c) at 77 K for mutually perpendicular current and magnetic field B in the a,b plane is 8 kA/cm 2 at 8 T, decreasing gradually to 3.7 kA/cm2 at 20 T, and remaining over 1 kA/cm2 out to 30 T. High magnetic field measurements of J(c) as a function of the angle-theta of B with respect to the c axis are also reported. In contrast to earlier results at lower fields (less-than-or-equal-to 3 T) the measurements reported here in high fields reveal a J(c) vs theta-curve with a head-and-shoulders shape, consisting of a sharp peak ("head") < 5-degrees wide for B parallel to the CuO2 planes, and a wide (30-degrees at 9 T, for example) shoulder region on either side of B perpendicular-to c axis, where the transport J(c) remains high and constant. Beyond the shoulder region, however, the transport J(c) decreases sharply, giving rise to the concept of a critical field angle for application design, defined by the minima in d2J(c)/d-theta-2 at the edge of the shoulders. C1 UNIV HOUSTON,TEXAS CTR SUPERCONDUCTIV,HOUSTON,TX 77004. RP EKIN, JW (reprint author), NATL INST STAND & TECHNOL,DIV ELECTROMAGNET TECHNOL,BOULDER,CO 80303, USA. NR 20 TC 70 Z9 72 U1 0 U2 4 PU AMER INST PHYSICS PI WOODBURY PA CIRCULATION FULFILLMENT DIV, 500 SUNNYSIDE BLVD, WOODBURY, NY 11797-2999 SN 0003-6951 J9 APPL PHYS LETT JI Appl. Phys. Lett. PD JUL 15 PY 1991 VL 59 IS 3 BP 360 EP 362 DI 10.1063/1.105595 PG 3 WC Physics, Applied SC Physics GA FW744 UT WOS:A1991FW74400037 ER PT J AU THOMPSON, WE JACOX, ME AF THOMPSON, WE JACOX, ME TI THE VIBRATIONAL-SPECTRA OF MOLECULAR-IONS ISOLATED IN SOLID NEON .7. CO+, C2O2+, AND C2O2- SO JOURNAL OF CHEMICAL PHYSICS LA English DT Article ID ELECTRON-SPIN-RESONANCE; CARBON-MONOXIDE; CATION RADICALS; METASTABLE ATOMS; IONIZATION; MATRICES; (CO)2+; ARGON; NO; PHOTODISSOCIATION AB When a Ne:CO = 100 mixture is codeposited at approximately 5 K with a beam of neon atoms that have been excited in a microwave discharge, several new infrared absorptions appear in the resulting sample deposit. Detailed isotopic substitution experiments support the assignment of these absorptions to CO+, trans-OCCO+, and trans-OCCO-. Analysis of the infrared data has permitted determination of the CO-stretching force constants of the dimer cation and anion and has yielded a preliminary estimate of the valence angles for trans-OCCO-. The role of electron capture in the "photobleaching" of trans-OCCO+ by visible radiation is considered. C1 NATL INST STAND & TECHNOL,DIV MOLEC PHYS,GAITHERSBURG,MD 20899. NR 43 TC 52 Z9 52 U1 2 U2 8 PU AMER INST PHYSICS PI WOODBURY PA CIRCULATION FULFILLMENT DIV, 500 SUNNYSIDE BLVD, WOODBURY, NY 11797-2999 SN 0021-9606 J9 J CHEM PHYS JI J. Chem. Phys. PD JUL 15 PY 1991 VL 95 IS 2 BP 735 EP 745 DI 10.1063/1.461079 PG 11 WC Chemistry, Physical; Physics, Atomic, Molecular & Chemical SC Chemistry; Physics GA FV976 UT WOS:A1991FV97600002 ER PT J AU ZWART, E LINNARTZ, H MEERTS, WL FRASER, GT NELSON, DD KLEMPERER, W AF ZWART, E LINNARTZ, H MEERTS, WL FRASER, GT NELSON, DD KLEMPERER, W TI MICROWAVE AND SUBMILLIMETER SPECTROSCOPY OF AR-NH3 STATES CORRELATING WITH AR+NH3 (J=1,KAPPA=1) SO JOURNAL OF CHEMICAL PHYSICS LA English DT Article ID INFRARED-LASER SPECTROSCOPY; VANDERWAALS BONDS; SPECTRUM; VIBRATION; ROTATION; AR-H2O; COMPLEXES; (H2O)2; BATH; AR AB Microwave and submillimeter transitions for Ar-NH3 have been observed and assigned for the SIGMA and PI-states correlating asymptotically with Ar + NH3 (j = 1,\k\= 1). The SIGMA-states are found to lie below the PI-states and are separated by approximately the inversion splitting of free NH3. For the PI-states the NH3 inversion tunneling is nearly quenched, being only weakly allowed through Coriolis interactions with the nearby-SIGMA-states. The observed microwave and submillimeter spectra also allow the determination of N-14 quadrupole coupling constants and relative submillimeter absorption intensities. All the above results are interpreted using a model internal-rotation inversion Hamiltonian, leading to detailed information about the anisotropy of the intermolecular potential. C1 NATL INST STAND & TECHNOL,DIV MOLEC PHYS,GAITHERSBURG,MD 20899. HARVARD UNIV,DEPT CHEM,CAMBRIDGE,MA 02138. RP ZWART, E (reprint author), CATHOLIC UNIV NIJMEGEN,FYS LAB,6525 ED NIJMEGEN,NETHERLANDS. RI Meerts, W. Leo/B-6172-2008 OI Meerts, W. Leo/0000-0001-6457-3797 NR 31 TC 44 Z9 44 U1 0 U2 1 PU AMER INST PHYSICS PI WOODBURY PA CIRCULATION FULFILLMENT DIV, 500 SUNNYSIDE BLVD, WOODBURY, NY 11797-2999 SN 0021-9606 J9 J CHEM PHYS JI J. Chem. Phys. PD JUL 15 PY 1991 VL 95 IS 2 BP 793 EP 803 DI 10.1063/1.461086 PG 11 WC Chemistry, Physical; Physics, Atomic, Molecular & Chemical SC Chemistry; Physics GA FV976 UT WOS:A1991FV97600009 ER PT J AU DIMARZIO, EA GUTTMAN, CM AF DIMARZIO, EA GUTTMAN, CM TI PEELING A POLYMER FROM A SURFACE OR FROM A LINE SO JOURNAL OF CHEMICAL PHYSICS LA English DT Article ID RUBBER ELASTICITY AB We calculate the force on a long linear polymer molecule whose one end is zippered down onto a surface or onto a line and whose other end is at a perpendicular distance R from the surface or line. Random coil statistics are used for the unattached portion of the chain. The method is extended to the case when the bonds within the zippered portion are breaking and reforming. We also consider the case where the attached portion is in the form of loops and trains. Although the energy equations of state for these various systems are different from each other, the force equation of state is always given by f = (square-root 6/l) square-root kT-DELTA-g, where l is the bond length between monomers and DELTA-g is the free energy change in pulling one monomer off of the surface. The force is independent of R except for small R. Applications are discussed briefly. They include (1) self-healing systems of gels and rubbers where the cross links may be hydrogen bonds; (2) adhesion; (3) the degree of crystallinity in crystal-amorphous lamellar systems; (4) the packing of DNA into the head of a bacteriophage virus and pulling apart of double stranded DNA; (5) an insight into the theory of rubber elasticity; (6) understanding the critical force for flow in thixotropic systems. RP DIMARZIO, EA (reprint author), NATL INST STAND & TECHNOL,GAITHERSBURG,MD 20899, USA. NR 15 TC 11 Z9 11 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 JUL 15 PY 1991 VL 95 IS 2 BP 1189 EP 1197 DI 10.1063/1.461149 PG 9 WC Chemistry, Physical; Physics, Atomic, Molecular & Chemical SC Chemistry; Physics GA FV976 UT WOS:A1991FV97600056 ER PT J AU TAFT, BA KESSLER, WS AF TAFT, BA KESSLER, WS TI VARIATIONS OF ZONAL CURRENTS IN THE CENTRAL TROPICAL PACIFIC DURING 1970 TO 1987 - SEA-LEVEL AND DYNAMIC HEIGHT MEASUREMENTS SO JOURNAL OF GEOPHYSICAL RESEARCH-OCEANS LA English DT Article ID TAHITI SHUTTLE EXPERIMENT; NORTH EQUATORIAL CURRENT; EL NINO; OCEAN; VARIABILITY; FLUCTUATIONS; TOPOGRAPHY; HAWAII; MODEL; WAVES AB The annual and interannual variations of the major zonal currents of the central tropical Pacific for the period 1970-1987 are described by analyzing two data sets: sea level data from a few selected island stations and ship-of-opportunity expendable bathythermograph (XBT) observations. The annual cycles of geostrophic surface current indices (dynamic height or sea level difference between the ridge and the trough defining the current) in the North Equatorial Current (NEC) and North Equatorial Countercurrent (NECC) are found to be in phase (maxima in November), to be strong, and to explain about 50% of the total variance. The annual cycle of volume transport relative to 400 dbar in the NECC is also strong, but NEC volume transport has a weak annual cycle. The discrepancy between the NEC surface current and the transport is due to the variation of the surface current being larger than that of the deep currents. The annual cycle of the transport of the South Equatorial Current (SEC) is 6 months out of phase with that of the NEC and NECC. Phases of the annual cycles of the sea level and dynamic height indices of flow agree well in general, but there are significant differences between the annual amplitudes of the two types of measurements. These differences arise from a variety of sources: dynamic height reference level assumptions, longitudinal spacing of sea level gauges, meridional resolution of sea level array, and different signal to noise ratios for the two sets of indices. The NECC shows marked flow maxima during the peaks of the strong Ninos of 1972 and 1982, which were followed by near disappearance of the current the following year; these fluctuations are clearly present in both the surface current indices and the volume transport. In 1976 and 1986-1987 (moderate Ninos) the same pattern is not marked. The El Nino signal in NEC transport is weak. There was a strong rise of equatorial sea level during the early phases of the 1972 and 1982 Ninos followed by a fall the next year. This resulted in a decrease of the transport of the SEC in the first year followed by an increase to a maximum during the second year; the maximum coincides with a minimum in NECC transport. C1 NOAA,PACIFIC MARINE ENVIRONM LAB,SEATTLE,WA 98115. UNIV WASHINGTON,JOINT INST STUDY ATMOSPHERE & OCEAN,SEATTLE,WA 98195. NR 48 TC 41 Z9 44 U1 0 U2 5 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 SN 0148-0227 J9 J GEOPHYS RES-OCEANS JI J. Geophys. Res.-Oceans PD JUL 15 PY 1991 VL 96 IS C7 BP 12599 EP 12618 DI 10.1029/91JC00781 PG 20 WC Oceanography SC Oceanography GA FX746 UT WOS:A1991FX74600010 ER PT J AU CANNON, GA PASHINSKI, DJ LEMON, MR AF CANNON, GA PASHINSKI, DJ LEMON, MR TI MIDDEPTH FLOW NEAR HYDROTHERMAL VENTING SITES ON THE SOUTHERN JUAN DE FUCA RIDGE SO JOURNAL OF GEOPHYSICAL RESEARCH-OCEANS LA English DT Article ID PACIFIC-OCEAN; PLUMES; TOPOGRAPHY; FIELDS; CIRCULATION; SEAMOUNT; CURRENTS; BALANCE AB Long-term moored current measurements around the southern end of the Juan de Fuca Ridge show that flow parallels the ridge and may be intensified by its presence. The mean flow is northward on the west side and southward on the east. Thus plumes emanating from the ridge probably are advected along the ridge before flowing away from the ridge. Other topographic features may be responsible for westward or eastward turning. Along the west side of the ridge, we hypothesize a regional flow pattern with southward flow north of Axial Seamount, northward flow south of Axial, and a convergence somewhere south of Axial resulting in westward flow. Along the east side, the flow may be southward everywhere. Above the ridge crest the long-term mean flow is weaker and more variable, and it includes tidal, inertial, and a dominant broadband 4-day oscillation. This 4-day energy is maximum in the rift valley (where the inertial is least), decreases upward and away from the ridge, and is more energetic in winter. This oscillation is predominately a clockwise rotating feature which, along with the presence of inertial oscillations, suggests that it may be storm-induced from the sea surface. These observations along with those by Cannon and Pashinski (1990) suggest northward propagation. Flow variations across the ridge lasting one to a few months have mean speeds of 1-3 cm/s and are capable of transporting plumes off axis to the west or east into the northerly or southerly flows, respectively. RP CANNON, GA (reprint author), NOAA,PACIF MARINE ENVIRONM LAB,DIV OCEAN ENVIRONM RES,SEATTLE,WA 98115, USA. NR 27 TC 42 Z9 42 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-OCEANS JI J. Geophys. Res.-Oceans PD JUL 15 PY 1991 VL 96 IS C7 BP 12815 EP 12831 DI 10.1029/91JC01023 PG 17 WC Oceanography SC Oceanography GA FX746 UT WOS:A1991FX74600024 ER PT J AU HOCKEY, BJ WIEDERHORN, SM LIU, W BALDONI, JG BULJAN, ST AF HOCKEY, BJ WIEDERHORN, SM LIU, W BALDONI, JG BULJAN, ST TI TENSILE CREEP OF WHISKER-REINFORCED SILICON-NITRIDE SO JOURNAL OF MATERIALS SCIENCE LA English DT Article ID HOT-PRESSED SI3N4; HIGH-TEMPERATURE CREEP; TOUGHENING BEHAVIOR; GLASS-CERAMICS; ALUMINA AB This paper presents a study of the creep and creep rupture behaviour of hot-pressed silicon nitride reinforced with 30 vol% SiC whiskers. The material was tested in both tension and compression at temperatures ranging from 1100 to 1250-degrees-C for periods as long as 1000 h. A comparison was made between the creep behaviour of whisker-reinforced and whisker-free silicon nitride. Principal findings were: (i) transient creep due to devitrification of the intergranular phase dominates high-temperature creep behaviour; (ii) at high temperatures and stresses, cavitation at the whisker-silicon nitride interface enhances the creep rate and reduces the life-time of the silicon nitride composite; (iii) resistance to creep deformation is greater in compression than in tension; (iv) the time to rupture is a power function of the creep rate, so that the temperature and stress dependence of the failure time is determined solely by the temperature and stress dependence of the creep rate; (v) as a consequence of differences in grain morphology and glass composition between whisker-free and whisker-reinforced material, little effect of whisker additions on the creep rate was observed. C1 GTE LABS INC,WALTHAM,MA 02254. RP HOCKEY, BJ (reprint author), NATL INST STAND & TECHNOL,GAITHERSBURG,MD 20899, USA. NR 26 TC 67 Z9 68 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 JUL 15 PY 1991 VL 26 IS 14 BP 3931 EP 3939 DI 10.1007/BF01184994 PG 9 WC Materials Science, Multidisciplinary SC Materials Science GA FY705 UT WOS:A1991FY70500037 ER PT J AU SANFORD, NA MALONE, KJ LARSON, DR AF SANFORD, NA MALONE, KJ LARSON, DR TI EXTENDED-CAVITY OPERATION OF RARE-EARTH-DOPED GLASS WAVE-GUIDE LASERS SO OPTICS LETTERS LA English DT Article ID WAVE-GUIDE LASER AB Channel waveguides fabricated in Nd-doped glass were used as gain elements for extended-cavity lasers. End-fire pumping was performed with a Ti:sapphire laser operating at 807 nm. The 4-nm FWHM output spectrum was centered near 1057 nm. Slope efficiencies were typically 4-11%, with thresholds near 20 mW. Active mode locking and Q switching were separately performed; mode-locked pulse widths were roughly 80 ps FWHM. Q-switched peak power was 1.2 W. The cw output narrowed to 7 GHz and tuned over a range of 24 nm when a grating provided feedback; single-frequency operation resulted when a high-reflectivity etalon was added. RP SANFORD, NA (reprint author), NATL INST STAND & TECHNOL,OPT ELECTR METROL GRP,MS 81402,325 BROADWAY,BOULDER,CO 80303, USA. NR 8 TC 10 Z9 10 U1 0 U2 0 PU OPTICAL SOC AMER PI WASHINGTON PA 2010 MASSACHUSETTS AVE NW, WASHINGTON, DC 20036 SN 0146-9592 J9 OPT LETT JI Opt. Lett. PD JUL 15 PY 1991 VL 16 IS 14 BP 1095 EP 1097 DI 10.1364/OL.16.001095 PG 3 WC Optics SC Optics GA FX982 UT WOS:A1991FX98200014 PM 19776887 ER PT J AU WOLTZ, LA JACOBS, VL HOOPER, CF MANCINI, RC AF WOLTZ, LA JACOBS, VL HOOPER, CF MANCINI, RC TI EFFECTS OF ELECTRIC MICROFIELDS ON ARGON DIELECTRONIC SATELLITE SPECTRA IN LASER-PRODUCED PLASMAS SO PHYSICAL REVIEW A LA English DT Article ID LINE-PROFILES AB Theoretical spectral-line profiles have been obtained for dielectronic satellite transitions in heliumlike and lithiumlike argon ions. Particular emphasis has been given to the systematic and self-consistent incorporation of the non-local-thermodynamic-equilibrium autoionizing-level populations, together with the line-broadening effects, which are due to autoionization processes, radiative transitions, electron collisions, and the action of the plasma ion-produced electric microfields. An investigation has been carried out of the effects of the plasma electric microfields on predicted dielectronic satellite line-intensity ratios, and a discussion is presented on the consequences of the electric-microfield effects for the spectroscopic determination of basic physical properties in laser-produced plasmas. C1 NATL INST STAND & TECHNOL,DIV ATOM & PLASMA RADIAT,GAITHERSBURG,MD 20899. USN,RES LAB,DIV CONDENSED MATTER & RADIAT SCI,WASHINGTON,DC 20375. UNIV FLORIDA,DEPT PHYS,GAINESVILLE,FL 32611. NR 13 TC 29 Z9 29 U1 0 U2 2 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 1050-2947 J9 PHYS REV A JI Phys. Rev. A PD JUL 15 PY 1991 VL 44 IS 2 BP 1281 EP 1286 DI 10.1103/PhysRevA.44.1281 PG 6 WC Optics; Physics, Atomic, Molecular & Chemical SC Optics; Physics GA FY463 UT WOS:A1991FY46300057 ER PT J AU OBRIEN, WL JIA, J DONG, QY CALLCOTT, TA RUBENSSON, JE MUELLER, DL EDERER, DL AF OBRIEN, WL JIA, J DONG, QY CALLCOTT, TA RUBENSSON, JE MUELLER, DL EDERER, DL TI INTERMEDIATE COUPLING IN L2-L3 CORE EXCITONS OF MGO, AL2O3, AND SIO2 SO PHYSICAL REVIEW B LA English DT Article ID X-RAY-ABSORPTION; CORUNDUM; SPECTRA AB The L23 reflection spectra for single-crystal MgO, alpha-Al2O3, and alpha-SiO2 are measured. These reflection spectra are used to generate absorption spectra that agree well with electron-total-yield and electron-energy-loss measurements. Exciton features are shown to exist in the band gap by comparing the valence-band maximum plus optical band gap to the observed transition energies. The energy splitting of the L2-L3 excitons, as seen in reflection, is clearly resolved for Al2O3 and SiO2, while in electron-total-yield measurements the doublets are not resolved for Al2O3. This resolution allows the calculation of the exchange energy using intermediate-coupling theory. C1 NATL INST STAND & TECHNOL,GAITHERSBURG,MD 20899. RP OBRIEN, WL (reprint author), UNIV TENNESSEE,KNOXVILLE,TN 37996, USA. NR 25 TC 40 Z9 40 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 JUL 15 PY 1991 VL 44 IS 3 BP 1013 EP 1018 DI 10.1103/PhysRevB.44.1013 PG 6 WC Physics, Condensed Matter SC Physics GA FW105 UT WOS:A1991FW10500008 ER PT J AU KISSLINGER, C JONES, LM AF KISSLINGER, C JONES, LM TI PROPERTIES OF AFTERSHOCK SEQUENCES IN SOUTHERN CALIFORNIA SO JOURNAL OF GEOPHYSICAL RESEARCH-SOLID EARTH AND PLANETS LA English DT Article ID IMPERIAL-VALLEY; HEAT-FLOW; EARTHQUAKE SEQUENCE; OCTOBER 15; JULY 1986; FAULT; SEISMICITY; SWARM AB The temporal behavior of 39 aftershock sequences in southern California, 1933-1988, was modeled by the modified Omori relation. Minimum magnitudes for completeness of each sequence catalog were determined, and the maximum likelihood estimates of the parameters K, p, and c, with the standard errors on each, were determined by the Ogata algorithm. The b value of each sequence was also calculated. Many of the active faults in the region, both strike slip and thrust, were sampled. The p values were graded in terms of the size of the standard error relative to the p value itself. Most of the sequences were modeled well by the Omori relation. Many of the sequences had p values close to the mean of the whole data set, 1.11 +/- 0.25, but values significantly different from the mean, as low as 0.7 and as high as 1.8, exist. No correlation of p with either the b value of the sequence or the mainshock magnitude was found. The results suggest a direct correlation of p values is with surface heat flow, with high values in the Salton Trough (high heat flow) and one low value in the San Bernardino Mountains and on the edge of the Ventura Basin (both low heat flow). The large fraction of the sequences with p values near the mean are at locations where the heat flow is near the regional mean, 74 mW/m2. If the hypothesis that aftershock decay rate is controlled by temperature at depth is valid, the effects of other factors such as heterogeneity of the fault zone properties are superimposed on the background rate determined by temperature. Surface heat flow is taken as an indicator of crustal temperature at hypocentral depths, but the effects on heat flow of convective heat transport and variations in near-surface thermal conductivity invalidate any simple association of local variations in heat flow with details of the subsurface temperature distribution. The interpretation is that higher temperatures in the aftershock source volume caused shortened stress relaxation times in the fault zone materials, leading to a faster decay rate (higher p value). In 1967, Mogi proposed such a relation on the basis of Japanese data. Seismic velocity distributions published for southern California generally support the hypothesis, with low velocities (higher temperatures) corresponding to high p values, and vice-versa. C1 US GEOL SURVEY,PASADENA,CA 91106. RP KISSLINGER, C (reprint author), UNIV COLORADO,NOAA,COOPERAT INST RES ENVIRONM SCI,CAMPUS BOX 216,BOULDER,CO 80309, USA. NR 48 TC 137 Z9 147 U1 4 U2 11 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 SN 0148-0227 J9 J GEOPHYS RES-SOLID PD JUL 10 PY 1991 VL 96 IS B7 BP 11947 EP 11958 DI 10.1029/91JB01200 PG 12 WC Geosciences, Multidisciplinary SC Geology GA FW819 UT WOS:A1991FW81900022 ER PT J AU HABERMANN, RE AF HABERMANN, RE TI SEISMICITY RATE VARIATIONS AND SYSTEMATIC CHANGES IN MAGNITUDES IN TELESEISMIC CATALOGS SO TECTONOPHYSICS LA English DT Article; Proceedings Paper CT SYMP ON EARTHQUAKE PREDICTION CY AUG 28-29, 1989 CL ISTANBUL, TURKEY ID EARTHQUAKES; CALIFORNIA; QUIESCENCE AB Seismicity rate variations are commonplace in teleseismic catalogs. These changes have two possible causes: they could be real, or they could be related to changes in the networks used to detect the events. It is clearly important to differentiate between these two possibilities. We demonstrate a technique for making this differentiation using uniform data generated with known rates and magnitude shifts. We then apply this technique to data from large regions of the world. All of these regions show significant variations in seismicity rates for sets with magnitude cutoffs of 5.0 and 5.5. We show that most of these changes have distributions in the magnitude domain which are consistent with systematic changes in magnitudes of between 0.1 and 0.2 units. These results suggest that most observed rate variations in teleseismic sets with high magnitude cutoffs are related to systematic changes in magnitudes and are, therefore, not real. This result has important implications for earthquake prediction and tectonic studies which interpret these variations. RP HABERMANN, RE (reprint author), UNIV COLORADO,US DEPT COMMERCE,CIRES,NATL GEOPHYS DATA CTR,NOAA,BOULDER,CO 80303, USA. NR 10 TC 58 Z9 60 U1 0 U2 0 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0040-1951 J9 TECTONOPHYSICS JI Tectonophysics PD JUL 10 PY 1991 VL 193 IS 4 BP 277 EP 289 DI 10.1016/0040-1951(91)90337-R PG 13 WC Geochemistry & Geophysics SC Geochemistry & Geophysics GA GA297 UT WOS:A1991GA29700004 ER PT J AU BOLSENGA, SJ HERDENDORF, CE NORTON, DC AF BOLSENGA, SJ HERDENDORF, CE NORTON, DC TI SPECTRAL TRANSMITTANCE OF LAKE ICE FROM 400-850 NM SO HYDROBIOLOGIA LA English DT Article DE ICE PAR TRANSMITTANCE; WATER PAR TRANSMITTANCE; WINTER ECOLOGY ID SEA ICE; IRRADIANCE AB Spectral transmittance signatures for a variety of freshwater ice types were collected in the 400-850 nm range. Clear ice showed the highest transmittances, snow-covered ice the lowest and other ice types intermediate transmittances. All of the ice spectral transmittance curves showed the same general shape with no mutually-exclusive characteristics exhibited by any ice type. The magnitude of the transmittance values was the primary distinguishing factor. The range of transmittance values directly under the ice was remarkably narrow (excluding snow-covered ice) and markedly different from values lower in the water column. C1 OHIO STATE UNIV,COLUMBUS,OH 43210. RP BOLSENGA, SJ (reprint author), GREAT LAKES ENVIRONM RES LAB,ANN ARBOR,MI 48105, USA. NR 27 TC 8 Z9 8 U1 1 U2 4 PU KLUWER ACADEMIC PUBL PI DORDRECHT PA SPUIBOULEVARD 50, PO BOX 17, 3300 AA DORDRECHT, NETHERLANDS SN 0018-8158 J9 HYDROBIOLOGIA JI Hydrobiologia PD JUL 5 PY 1991 VL 218 IS 1 BP 15 EP 25 DI 10.1007/BF00006414 PG 11 WC Marine & Freshwater Biology SC Marine & Freshwater Biology GA GE264 UT WOS:A1991GE26400002 ER PT J AU RUHL, JC EVANS, DH HAPIOT, P NETA, P AF RUHL, JC EVANS, DH HAPIOT, P NETA, P TI FAST CLEAVAGE REACTIONS FOLLOWING ELECTRON-TRANSFER - REDUCTION OF 1,1-DINITROCYCLOHEXANE SO JOURNAL OF THE AMERICAN CHEMICAL SOCIETY LA English DT Article ID HOMOGENEOUS REDOX CATALYSIS; ELECTROCHEMICAL TRANSFER-COEFFICIENT; VICINAL DINITRO COMPOUNDS; TRANSFER RATE CONSTANTS; SUBSTITUTION-REACTIONS; OXIDATION POTENTIALS; CYCLIC VOLTAMMETRY; SWEEP VOLTAMMETRY; TRANSFER KINETICS; ANION RADICALS AB One-electron reduction of 1,1-dinitrocyclohexane is followed by rapid cleavage of a C-N bond, giving nitrite and 1-nitrocyclohexyl radical. The rate constant has been determined in dimethylformamide by homogeneous redox catalysis (1.6 x 10(6) s-1) and in aqueous solution by pulse radiolysis (1.1 x 10(6) s-1). These values are of the order of 10(6) larger than the rate constant for cleavage of mononitroalkane radical anions. In the case of electrochemical reduction, the electron transfer and bond cleavage are followed by further reduction of the nitroalkyl radical to give the nitronate anion of nitrocyclohexane. For scan rates exceeding about 0.1 V/s in cyclic voltammetry, the 1-nitrocyclohexyl radical is reduced by the anion radical of 1,1-dinitrocyclobexane rather than at the electrode. Controlled potential electrolysis and product analysis showed that about 1.2 electrons were required per molecule of 1,1-dinitrocyclohexane; essentially no nitronate was found, but instead some nitrocyclohexane and substantial amounts of 1,1'-dinitrobicyclohexyl (5) were produced. This latter product arises from the radical chain reaction of nitronate with starting material. A key chain-carrying step in this reaction scheme is the reaction of l-nitrocyclohexyl radical with the nitronate to give the anion radical of 5. The rate constant for this step was found to be 2.6 x 10(6) L mol-1 s-1 in water by pulse radiolysis. Fitting of fast-scan cyclic voltammograms by digital simulation showed that this rate constant must be about 5 x 10(8) L mol-1 s-1 in dimethylformamide with a termination reaction (k(t) = 2 x 10(4) s-1) of hydrogen atom abstraction by 1-nitrocyclohexyl to produce the nitrocyclohexane found in the electrolyzed solutions. C1 UNIV DELAWARE,DEPT CHEM & BIOCHEM,NEWARK,DE 19716. NATL INST STAND & TECHNOL,DIV CHEM KINET,GAITHERSBURG,MD 20899. NR 47 TC 19 Z9 19 U1 1 U2 5 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 SN 0002-7863 J9 J AM CHEM SOC JI J. Am. Chem. Soc. PD JUL 3 PY 1991 VL 113 IS 14 BP 5188 EP 5194 DI 10.1021/ja00014a007 PG 7 WC Chemistry, Multidisciplinary SC Chemistry GA FU900 UT WOS:A1991FU90000007 ER PT J AU ONDOV, JM KELLY, WR AF ONDOV, JM KELLY, WR TI TRACING AEROSOL POLLUTANTS WITH RARE-EARTH ISOTOPES SO ANALYTICAL CHEMISTRY LA English DT Article ID ATMOSPHERIC TRACERS C1 NBS,CTR ANALYT CHEM,GAITHERSBURG,MD 20899. RP ONDOV, JM (reprint author), UNIV MARYLAND,DEPT CHEM & BIOCHEM,COLLEGE PK,MD 20742, USA. NR 15 TC 10 Z9 10 U1 1 U2 2 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 SN 0003-2700 J9 ANAL CHEM JI Anal. Chem. PD JUL 1 PY 1991 VL 63 IS 13 BP A691 EP A697 DI 10.1021/ac00013a001 PG 7 WC Chemistry, Analytical SC Chemistry GA FV113 UT WOS:A1991FV11300003 PM 1897723 ER PT J AU PLANT, AL LOCASCIOBROWN, L HALLER, W DURST, RA AF PLANT, AL LOCASCIOBROWN, L HALLER, W DURST, RA TI IMMOBILIZATION OF BINDING-PROTEINS ON NONPOROUS SUPPORTS - COMPARISON OF PROTEIN LOADING, ACTIVITY, AND STABILITY SO APPLIED BIOCHEMISTRY AND BIOTECHNOLOGY LA English DT Article DE ANTIBODY IMMOBILIZATION; PROTEIN IMMOBILIZATION; BINDING ACTIVITY; PROTEIN DETERMINATION; GLASS; NYLON; POLYSTYRENE ID AFFINITY-CHROMATOGRAPHY; SOLID-SURFACES; ADSORPTION; ANTIBODIES; IMMUNOASSAY; ALBUMIN; NYLON; ACID AB Four different nonporous particulate materials, nylon, polystyrene, soda-lime silicate glass, and fused silica glass, have been evaluated for their appropriateness as immobilization supports for immunoglobulins. A method of protein quantitation that is usually applied to solutions, the bicinchoninic acid (BCA) assay, was used successfully to directly measure ng amounts of protein immobilized on the supports. Two proteins, a monoclonal antibody to theophylline and the biotin binding protein avidin, were studied. Radioactive theophylline and radioactive biotin were used to measure the activity of the immobolized protein. Ligand binding capacity per mm2 of support was measured as a function of amount of protein immobilized. By measuring both the amount of protein immobilized and its ligand binding capacity, we have determined that antitheophylline antibody adsorbed on polystyrene balls loses almost 90% of its binding activity after 65 h, although little protein is lost from the balls over this time. Avidin retains nearly full activity for biotin on polystyrene. The binding activity of biotinyl-antibody conjugate immobilized on avidin-adsorbed polystyrene is stable, even when stored for over 22 wk. Antibody covalently immobilized on soda-lime silicate glass beads retains its binding activity over long-term storage, although only 0.1 mol of H-3-theophylline bind per mol of immobilized antibody. Using fused silica glass particles as the solid support, the same antibody binds approx 0.6 mol of ligand per mol of immobilized antibody protein. The structural "softness" of the immunoglobulin requires that interaction with the surface be prevented in order to maintain activity. C1 NATL INST STAND & TECHNOL,CTR MAT SCI,DIV CERAM,GAITHERSBURG,MD 20899. RP PLANT, AL (reprint author), NATL INST STAND & TECHNOL,CTR ANALYT CHEM,ORGAN ANALYT RES DIV,GAITHERSBURG,MD 20899, USA. NR 27 TC 57 Z9 57 U1 1 U2 14 PU HUMANA PRESS INC PI TOTOWA PA 999 RIVERVIEW DRIVE SUITE 208, TOTOWA, NJ 07512 SN 0273-2289 J9 APPL BIOCHEM BIOTECH JI Appl. Biochem. Biotechnol. PD JUL PY 1991 VL 30 IS 1 BP 83 EP 98 PG 16 WC Biochemistry & Molecular Biology; Biotechnology & Applied Microbiology SC Biochemistry & Molecular Biology; Biotechnology & Applied Microbiology GA FX089 UT WOS:A1991FX08900007 PM 1952925 ER PT J AU HILLIER, DJ AF HILLIER, DJ TI THE EFFECTS OF ELECTRON-SCATTERING AND WIND CLUMPING FOR EARLY EMISSION-LINE STARS SO ASTRONOMY & ASTROPHYSICS LA English DT Article DE RADIATIVE TRANSFER; STARS, ATMOSPHERES OF; STARS, WOLF-RAYET; STARS, EMISSION-LINE; LINES, FORMATION; LINES, PROFILES ID WOLF-RAYET STARS; MASS-LOSS RATES; HOT STARS; INFRARED OBSERVATIONS; SPECTRAL-ANALYSIS; COMOVING-FRAME; HD-50896; EVOLUTION; MODELS; ATMOSPHERES AB Using two independent codes we have made a detailed study of the influence of electron scattering on line profiles arising from stellar winds around early emission line stars. These calculations indicate that the assumption of isotropic scattering gives acceptable answers when compared with more accurate calculations using a dipole phase function. On the other hand the use of angle-averaged redistribution functions can noticeably affect the strength of the predicted electron scattering wings. In addition we show that the velocity (arising from thermal and turbulent motions) adopted for the Doppler line absorption profile can dramatically influence the strength of electron scattering wings for a line that is optically thick throughout most of its formation region. We have examined a crude Wolf-Rayet (W-R) stellar wind model with a density structure stratified in spherical shells in order to investigate the influence of density inhomogeneities on predicted line profiles, and hence on the inferred properties of W-R stars. As expected, line profiles and line strengths in reasonable accord with observation can be reproduced, but for a lower mean mass loss rate. As a consequence profiles can be produced that have the correct line strength but with a significant reduction in the strength of the electron scattering wing. This may help to explain evidence that theoretical electron scattering wings are stronger than those observed. If correct, mass loss rates for W-R stars may have been overestimated, with important implications for our understanding of massive star evolution. The shell model has an ionization and temperature structure qualitatively similar to smooth models - the decrease in ionization with radius is still an intrinsic property of these models. C1 NATL INST STAND & TECHNOL, BOULDER, CO 80309 USA. RP HILLIER, DJ (reprint author), UNIV COLORADO, JOINT INST LAB ASTROPHYS, DEPT PUBLICAT, BOULDER, CO 80309 USA. NR 61 TC 192 Z9 192 U1 0 U2 2 PU EDP SCIENCES S A PI LES ULIS CEDEX A PA 17, AVE DU HOGGAR, PA COURTABOEUF, BP 112, F-91944 LES ULIS CEDEX A, FRANCE SN 0004-6361 J9 ASTRON ASTROPHYS JI Astron. Astrophys. PD JUL PY 1991 VL 247 IS 2 BP 455 EP 468 PG 14 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA FZ707 UT WOS:A1991FZ70700027 ER PT J AU FERRIERE, KM MACLOW, MM ZWEIBEL, EG AF FERRIERE, KM MACLOW, MM ZWEIBEL, EG TI EXPANSION OF A SUPERBUBBLE IN A UNIFORM MAGNETIC-FIELD SO ASTROPHYSICAL JOURNAL LA English DT Article DE HYDROMAGNETICS; INTERSTELLAR, MATTER; SHOCK WAVES; STARS, SUPERNOVAE ID H-I SHELLS; SUPERNOVA-REMNANTS; THEORETICAL-MODELS; MASSIVE STARS; O-STARS; SUPERSHELLS; SHOCKS; ASSOCIATION; EXPLOSIONS; GALAXIES AB We investigate the effects of interstellar magnetic fields on the evolution and structure of superbubbles. We first derive the governing equations for propagation of a radiative shock, and solve them analytically in the limit of high expansion velocity. We then present a numerical code able to solve them in the general case and discuss the numerical results. We find that magnetic fields of the strength present in the Galactic disk do not significantly modify the overall shape and dimensions of a superbubble. They reduce the volume of the interior cavity by one-third on average during the expansion phase. The shell elongates slightly in the direction of the external field. Magnetic pressure dominates over gas pressure in most of the shell and forces it to thicken substantially. Finally, because of the transverse mass motions which take place from the magnetic poles to the equator, the column density at the poles is reduced by typically a factor of 10. C1 NASA,AMES RES CTR,THEORET STUDIES BRANCH,MOFFETT FIELD,CA 94035. UNIV COLORADO,NATL INST STAND & TECHNOL,JOINT INST LAB ASTROPHYS,BOULDER,CO 80302. RP FERRIERE, KM (reprint author), UNIV COLORADO,DEPT ASTROPHYS PLANETARY & ATMOSPHER SCI,CAMPUS BOX 391,BOULDER,CO 80309, USA. OI Mac Low, Mordecai-Mark/0000-0003-0064-4060 NR 47 TC 94 Z9 94 U1 1 U2 3 PU UNIV CHICAGO PRESS PI CHICAGO PA 5720 S WOODLAWN AVE, CHICAGO, IL 60637 SN 0004-637X J9 ASTROPHYS J JI Astrophys. J. PD JUL 1 PY 1991 VL 375 IS 1 BP 239 EP 253 DI 10.1086/170185 PN 1 PG 15 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA FT836 UT WOS:A1991FT83600022 ER PT J AU WINGLEE, RM KIPLINGER, AL ZARRO, DM DULK, GA LEMEN, JR AF WINGLEE, RM KIPLINGER, AL ZARRO, DM DULK, GA LEMEN, JR TI INTERRELATION OF SOFT AND HARD X-RAY EMISSIONS DURING SOLAR-FLARES .1. OBSERVATIONS SO ASTROPHYSICAL JOURNAL LA English DT Article DE PARTICLE ACCELERATION; RADIATION MECHANISMS; SUN, FLARES; SUN, X-RAYS ID LOOP RADIATIVE HYDRODYNAMICS; RETURN CURRENT SYSTEMS; CHROMOSPHERIC EVAPORATION; IMPULSIVE PHASE; RADIO SPIKES; PLASMA; ELECTRONS; MOTIONS; SPECTRA; BURSTS AB Simultaneous observations of hard X-rays and of soft X-ray line emissions at high time resolution (congruent-to 6 s) from the Solar Maximum Mission (SMM) are used to determine the interrelation between the acceleration and heating of electrons and ions during impulsive solar flares. The study involves five flares (three disk and two limb flares). It is shown that for all the flares, the hard X-rays have a power-law spectrum which breaks down during the rise phase and beginning of the decay phase, after which the spectrum changes to either a single power law or a power law which breaks up at high energies. The characteristics of the soft X-rays depend on the flare position. For the three disk flares, the line emissions show a blueshifted component (arising from upward acceleration of ions into the corona) with the maximum inferred velocity reaching its peak value during the decay phase in association with the disappearance of the (downward) break in the hard X-ray spectrum. For limb flares the soft X-ray line emissions show only a nonthermally broadened stationary component (arising from acceleration and heating perpendicular to the magnetic field); this broadening reaches a maximum at the hard (greater-than-or-similar-to 50 keV) X-ray peak rather than during the decay phase. These observations are not consistent with models where the chromospheric outflow is driven by explosive heating since both the blueshifts and broadening are predicted to have the same dependence on the hard X-ray flux. It is argued instead that small-scale quasi-static electric fields are important for determining the acceleration of the X-ray-producing electrons and the outflowing chromospheric ions. These electric fields provide bulk acceleration of energetic electrons into the chromosphere (with the electric potential being of the order of the break energy). At the same time, they accelerate ions across the field lines and out into the corona. The different behavior of the blueshifts and broadening relative to the hard X-ray emissions is attributed to differences in scale lengths parallel and perpendicular to the magnetic field. C1 UNIV COLORADO,DEPT ASTROPHYS PLANETARY & ATMOSPHER SCI,BOULDER,CO 80309. NASA,GODDARD SPACE FLIGHT CTR,GREENBELT,MD 20771. NOAA,SPACE ENVIRONM LAB,BOULDER,CO 80303. LOCKHEED PALO ALTO RES LABS,DEPT 9130,PALO ALTO,CA 94304. APPL RES CORP,PALO ALTO,CA. NR 43 TC 23 Z9 23 U1 0 U2 0 PU UNIV CHICAGO PRESS PI CHICAGO PA 5720 S WOODLAWN AVE, CHICAGO, IL 60637 SN 0004-637X J9 ASTROPHYS J JI Astrophys. J. PD JUL 1 PY 1991 VL 375 IS 1 BP 366 EP 381 DI 10.1086/170196 PN 1 PG 16 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA FT836 UT WOS:A1991FT83600033 ER PT J AU WINGLEE, RM DULK, GA BORNMANN, PL BROWN, JC AF WINGLEE, RM DULK, GA BORNMANN, PL BROWN, JC TI INTERRELATION OF SOFT AND HARD X-RAY EMISSIONS DURING SOLAR-FLARES .2. SIMULATION-MODEL SO ASTROPHYSICAL JOURNAL LA English DT Article DE PARTICLE ACCELERATION; RADIATION MECHANISMS; SUN, FLARES; SUN, X-RAYS ID LOOP RADIATIVE HYDRODYNAMICS; CHROMOSPHERIC EVAPORATION; CONDUCTION FRONTS; HEAVY-IONS; ACCELERATION; PLASMAS; RESOLUTION; BURSTS; EVENTS; PHASE AB Recent observations indicated that quasi-static electric fields may be important in the acceleration of the electrons responsible for hard X-ray emissions during impulsive solar flares. Quasi-static fields are also required to drive and to close the currents carried by the accelerated electrons. Two-dimensional (three velocity) electrostatic particle simulations are presented which incorporate the effects of these fields on the particle dynamics as well as those arising from wave-particle interactions induced by the accelerated particles. In the model, the particle acceleration is initiated by a cross-field current in the corona. Because of the limited cross-field mobility of particles in a collisionless plasma, this current can only be closed in the chromosphere where cross-field transport is aided by collisions. As a result, strong quasi-static electric fields are set up which produce strong downward acceleration of electrons in the primary current region. On adjacent field lines, electrons are accelerated up into the corona to provide a return current, but because of the relatively large cross-section of the return current region, the electrons in this region remain relatively low in energy. The induced perpendicular currents are initially provided by the ions, but, as the chromosphere becomes heated by precipitation of energetic electrons, perpendicular electron currents become important, and these currents in turn modify the particle acceleration in the latter part of the flare. The calculated properties of the soft and hard X-ray and microwave emissions from such a system have the following properties: (1) acceleration by quasi-static electric fields and heating via wave-particle interactions produces electron distributions with a broken-power law, similar to those inferred from hard X-ray spectra; (2) heating of the ambient plasma gives rise to a region of hot plasma which propagates down to the chromosphere at about the ion sound speed; (3) the arrival of this hot plasma region in the chromosphere causes the hard X-ray flux to peak due to modification of the cross-field conductivity so that the passage of soft X-ray fronts and the hard X-ray peak are expected to be correlated; (4) the perpendicular heating of coronal electrons is relatively slow, and this can give rise to the observed delay of the microwave peak relative to the hard X-ray peak; (5) heavy ions are preferentially accelerated across the fields as the cross-field currents form, leading to enhancements of heavy ion abundances in the primary current region; this enhanced heavy ion abundance may account for those inferred from soft X-ray line emissions; (6) the ions in the primary current region are then accelerated upward by the same electric fields accelerating the hard X-ray electrons downward; and (7) this parallel and perpendicular acceleration can give rise to Doppler shifts in soft X-ray line emissions similar to those seen during disk and limb flares. C1 UNIV COLORADO,DEPT ASTROPHYS PLANETARY & ATMOSPHER SCI,BOULDER,CO 80309. NOAA,SPACE ENVIRONM LAB,BOULDER,CO 80303. UNIV COLORADO,COOPERAT INST RES ENVIRONM SCI,BOULDER,CO 80309. UNIV GLASGOW,DEPT PHYS & ASTRON,GLASGOW G12 8QQ,SCOTLAND. NR 52 TC 20 Z9 20 U1 0 U2 0 PU UNIV CHICAGO PRESS PI CHICAGO PA 5720 S WOODLAWN AVE, CHICAGO, IL 60637 SN 0004-637X J9 ASTROPHYS J JI Astrophys. J. PD JUL 1 PY 1991 VL 375 IS 1 BP 382 EP 403 DI 10.1086/170197 PN 1 PG 22 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA FT836 UT WOS:A1991FT83600034 ER PT J AU STOCKE, JT MORRIS, SL GIOIA, IM MACCACARO, T SCHILD, R WOLTER, A FLEMING, TA HENRY, JP AF STOCKE, JT MORRIS, SL GIOIA, IM MACCACARO, T SCHILD, R WOLTER, A FLEMING, TA HENRY, JP TI THE EINSTEIN-OBSERVATORY EXTENDED MEDIUM-SENSITIVITY SURVEY .2. THE OPTICAL IDENTIFICATIONS SO ASTROPHYSICAL JOURNAL SUPPLEMENT SERIES LA English DT Article DE BL LACERTAE OBJECTS; GALAXIES, NUCLEI; GALAXIES, X-RAYS; QUASARS; STARS, X-RAYS; X-RAYS, SOURCES ID X-RAY SOURCES; ACTIVE GALACTIC NUCLEI; BL-LACERTAE OBJECTS; N-LOG-S; QUASI-STELLAR OBJECTS; T-TAURI STARS; LUMINOSITY FUNCTION; ELLIPTICAL GALAXY; SEYFERT-GALAXIES; COMPLETE SAMPLE AB The optical identifications of the Einstein Extended Medium Sensitivity Survey (EMSS) are presented. At present over 96% of the 835 X-ray sources in the survey have been successfully identified in the following proportions: active galactic nuclei (QSOs, quasars, and Seyferts), 51.1%; BL Lacertae objects, 4.3%; clusters of galaxies, 12.2%; normal galaxies, 2.1%; cooling flow galaxies, 0.6%; Galactic stars, 25.8%; and unidentified, 3.9%. All of the EMSS sources are identified with previously known classes of X-ray emitters except for five sources now identified with cooling flow galaxies whose novel attributes are described. The Galactic stars are primarily normal dwarf stars but also include RS CVn and W UMa binary systems, two FK Comae stars, five cataclysmic variables including new examples of AM Herculis stars, one white dwarf, and one X-ray binary candidate. The extragalactic sources are predominantly AGNs, which range from low-z, low-luminosity (z < 0.1; L(x) < 10(43) ergs s-1) Seyfert galaxies to high-z QSOs (z > 2) but also include distant clusters of galaxies (0.05 < z < 0.6), BL Lac objects (0.15 < z < 0.65) and nearby, normal galaxies (z less-than-or-equal-to 0.1). Most of the individual optical counterparts are previously unknown objects and so constitute large statistical samples independent of previous selection methods. Confusion levels due to chance projection onto the X-ray error circles and to spatially unresolved close pairs of X-ray sources are estimated to be quite small (approximately 20 sources), consistent with the numbers of such sources identified within the EMSS already. The small confusion levels within the EMSS validate the identification procedure in which spectra are obtained within and adjacent to each error circle until a plausible counterpart is discovered. The criteria used to determine whether the proposed optical counterpart to the X-ray source is a plausible identification are described in detail. Plausibility is based upon the optical classification of the counterpart (e.g., AGN, cluster, G star) and the X-ray-to-optical flux ratios previously observed for these classes of X-ray emitters. Two independent schemes of optical classification of the counterparts are used to check the plausibility of these identifications; one scheme based upon moderate-resolution optical spectroscopy (7 angstrom resolution in the range 3400-6400 angstrom) and R-band CCD direct imaging, and the other based upon the inferred X-ray luminosity and the overall (radio-optical-X-ray) energy distribution. Counterparts whose optical classification is somewhat ambiguous are a small fraction of the total and include sources which are either (a) low-luminosity AGNs or high-luminosity normal spiral galaxies; (b) low-luminosity clusters of galaxies or high-luminosity elliptical galaxies; (c) AGNs with unusual spectra lacking convincing evidence of broad emission lines; (d) AGNs with extremely weak emission lines (W-lambda less-than-or-equal-to 30 angstrom); and (e) BL Lac objects with modest starlight contributions. C1 CARNEGIE INST WASHINGTON,OBSERV,PASADENA,CA 91101. HARVARD SMITHSONIAN CTR ASTROPHYS,CAMBRIDGE,MA 02138. UNIV COLORADO,NATL INST STAND & TECHNOL,JOINT INST LAB ASTROPHYS,BOULDER,CO 80302. MAX PLANCK INST EXTRATERRESTR PHYS,W-8046 GARCHING,GERMANY. UNIV HAWAII,INST ASTRON,HONOLULU,HI 96822. RP STOCKE, JT (reprint author), UNIV COLORADO,CTR ASTROPHYS & SPACE ASTRON,CAMPUS BOX 391,BOULDER,CO 80309, USA. RI Morris, Simon/G-7981-2011; Gioia, Isabella/B-6982-2012; OI Morris, Simon/0000-0003-4866-110X; Gioia, Isabella/0000-0003-3127-498X; Wolter, Anna/0000-0001-5840-9835 NR 112 TC 739 Z9 742 U1 0 U2 2 PU UNIV CHICAGO PRESS PI CHICAGO PA 5720 S WOODLAWN AVE, CHICAGO, IL 60637 SN 0067-0049 J9 ASTROPHYS J SUPPL S JI Astrophys. J. Suppl. Ser. PD JUL PY 1991 VL 76 IS 3 BP 813 EP 874 DI 10.1086/191582 PG 62 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA FR382 UT WOS:A1991FR38200001 ER PT J AU GOLDBERG, RN TEWARI, YB AF GOLDBERG, RN TEWARI, YB TI THERMODYNAMICS OF THE DISPROPORTIONATION OF ADENOSINE 5'-DIPHOSPHATE TO ADENOSINE 5'-TRIPHOSPHATE AND ADENOSINE 5'-MONOPHOSPHATE .1. EQUILIBRIUM-MODEL SO BIOPHYSICAL CHEMISTRY LA English DT Article DE ACTIVITY COEFFICIENTS; ADENOSINE 5'-DIPHOSPHATE; ADENOSINE 5'-MONOPHOSPHATE; ADENOSINE 5'-TRIPHOSPHATE; ADENYLATE KINASE; ENTHALPY; ENZYME CATALYZED REACTIONS; ENTROPY; EQUILIBRIUM CONSTANTS; GIBBS ENERGY; HEAT CAPACITY; THERMODYNAMICS ID BI-UNIVALENT COMPOUNDS; DIVALENT METAL-IONS; OSMOTIC COEFFICIENTS; EVALUATED ACTIVITY; AQUEOUS-SOLUTIONS; STABILITY-CONSTANTS; NUCLEOSIDE PHOSPHATES; IONIZATION-CONSTANTS; ADENINE-NUCLEOTIDES; ALKALI-METAL AB The thermodynamic treatment of the disproportionation reaction of adenosine 5'-diphosphate to adenosine 5'-triphosphate and adenosine 5'-monophosphate is discussed in terms of an equilibrium model which includes the effects of the multiplicity of ionic and metal bound species and the presence of long range electrostatic and short range repulsive interactions. Calculated quantities include equilibrium constants, enthalpies, heat capacities, entropies, and the stoichiometry of the overall reaction. The matter of how these calculations can be made self-consistent with respect to both calculated values of the ionic strength and the molality of the free magnesium ion is discussed. The thermodynamic data involving proton and magnesium-ion binding data for the nucleotides involved in this reaction have been evaluated. RP GOLDBERG, RN (reprint author), NATL INST STAND & TECHNOL,DIV CHEM THERMODYNAM,GAITHERSBURG,MD 20899, USA. NR 95 TC 88 Z9 88 U1 0 U2 8 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0301-4622 J9 BIOPHYS CHEM JI Biophys. Chem. PD JUL PY 1991 VL 40 IS 3 BP 241 EP 261 DI 10.1016/0301-4622(91)80024-L PG 21 WC Biochemistry & Molecular Biology; Biophysics; Chemistry, Physical SC Biochemistry & Molecular Biology; Biophysics; Chemistry GA FX927 UT WOS:A1991FX92700004 PM 17014781 ER PT J AU TEWARI, YB GOLDBERG, RN ADVANI, JV AF TEWARI, YB GOLDBERG, RN ADVANI, JV TI THERMODYNAMICS OF THE DISPROPORTIONATION OF ADENOSINE 5'-DIPHOSPHATE TO ADENOSINE 5'-TRIPHOSPHATE AND ADENOSINE 5'-MONOPHOSPHATE .2. EXPERIMENTAL-DATA SO BIOPHYSICAL CHEMISTRY LA English DT Article DE ACTIVITY COEFFICIENTS; ADENOSINE 5'-DIPHOSPHATE; ADENOSINE 5'-MONOPHOSPHATE; ADENOSINE 5'-TRIPHOSPHATE; ADENYLATE KINASE; ENTHALPY; ENZYME CATALYZED REACTIONS; ENTROPY; EQUILIBRIUM; GIBBS ENERGY; HEAT CAPACITY; THERMODYNAMICS ID FREE MG2+; MAGNESIUM; EQUILIBRIUM AB High-pressure liquid-chromatography and microcalorimetry have been used to determine equilibrium constants and enthalpies of reaction for the disproportionation reaction of adenosine 5'-diphosphate (ADP) to adenosine 5'-triphosphate (ATP) and adenosine 5'-monophosphate (AMP). Adenylate kinase was used to catalyze this reaction. The measurements were carried out over the temperature range 286 to 311 K, at ionic strengths varying from 0.06 to 0.33 mol kg-1, over the pH range 6.04 to 8.87, and over the pMg range 2.22 to 7.16, where pMg = -log a(Mg2+). The equilibrium model developed by Goldberg and Tewari (see the previous paper in this issue) was used for the analysis of the measurements. Thus, for the reference reaction: 2 ADP3- (ao) reversible AMP2- (ao) + ATP4- (ao), K-degrees = 0.225 +/- 0.010, DELTA-G-degrees = 3.70 +/- 0.11 kJ mol-1, DELTA-H-degrees = -1.5 +/- 1.5 kJ mol-1, DELTA-S-degrees = -17 +/- 5 J mol-1 K-1, and DELTA-C(p)-degrees almost-equal-to -46 J mol-1 K-1 at 298.15 K and 0.1 MPa. These results and the thermodynamic parameters for the auxiliary equilibria in solution have been used to model the thermodynamics of the disproportionation reaction over a wide range of temperature, pH, ionic strength, and magnesium ion molality. Under approximately physiological conditions (311.15 K, pH 6.94, [Mg2+] = 1.35 x 10(-3) mol kg-1, and I = 0.23 mol kg-1) the apparent equilibrium constant (K'(A) = m(SIGMA-AMP)m(SIGMA-ATP)/[m(SIGMA-ADP)]2) for the overall disproportionation reaction is equal to 0.93 +/- 0.02. Thermodynamic data on the disproportionation reaction and literature values for this apparent equilibrium constant in human red blood cells are used to calculate a molality of 1.94 x 10(-4) mol kg-1 for free magnesium ion in human red blood cells. The results are also discussed in relation to thermochemical cycles and compared with data on the hydrolysis of the guanosine phosphates. C1 US FDA,ROCKVILLE,MD 20857. RP TEWARI, YB (reprint author), NATL INST STAND & TECHNOL,DIV CHEM THERMODYNAM,GAITHERSBURG,MD 20899, USA. NR 33 TC 15 Z9 15 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 JUL PY 1991 VL 40 IS 3 BP 263 EP 276 DI 10.1016/0301-4622(91)80025-M PG 14 WC Biochemistry & Molecular Biology; Biophysics; Chemistry, Physical SC Biochemistry & Molecular Biology; Biophysics; Chemistry GA FX927 UT WOS:A1991FX92700005 PM 17014782 ER PT J AU PERRIN, WF AF PERRIN, WF TI WHY ARE THERE SO MANY KINDS OF WHALES AND DOLPHINS SO BIOSCIENCE LA English DT Article RP PERRIN, WF (reprint author), NATL MARINE FISHERIES SERV,SW FISHERIES SCI CTR,LA JOLLA,CA 92038, USA. NR 0 TC 4 Z9 4 U1 1 U2 2 PU AMER INST BIOLOGICAL SCI PI WASHINGTON PA 1444 EYE ST, NW, STE 200, WASHINGTON, DC 20005 SN 0006-3568 J9 BIOSCIENCE JI Bioscience PD JUL-AUG PY 1991 VL 41 IS 7 BP 460 EP 461 DI 10.2307/1311801 PG 2 WC Biology SC Life Sciences & Biomedicine - Other Topics GA FT985 UT WOS:A1991FT98500006 ER PT J AU COLE, KD AF COLE, KD TI PURIFICATION OF PLASMID AND HIGH MOLECULAR MASS DNA USING PEG-SALT 2-PHASE EXTRACTION SO BIOTECHNIQUES LA English DT Note ID PROTEINS AB A method for the rapid preparation of DNA is described. The method utilizes a polymer (polyethylene glycol) and salt solution to form a two-phase system. A crude source of DNA is added to a phase-forming mixture, it is mixed and phase separation occurs. Under the appropriate conditions, the nucleic acids remain in the lower (salt-rich) phase, while the proteins, cellular debris and other constituents are in the upper phase (polymer-rich) or are precipitated at the interphase region. Incorporation of protein denaturants (detergents and chaotropes) stop the action of liberated nucleases in the sample. The nucleic acids are obtained in an intact state and in a form suitable for further manipulation, as shown by gel electrophoresis and DNA restriction digestion. This method describes the conditions of the two-phase systems that are important for the separation of nucleic acids and proteins. The important phase-forming conditions shown in this paper are pH, polymer molecular weight and concentration, salt type and concentration and the addition of detergents and chaotropic agents. With the use of these extraction conditions, proteins can be moved selectively from the lower to the upper phase. The paper describes a method for DNA isolation that is rapid, simple and economical. RP COLE, KD (reprint author), NATL INST STAND & TECHNOL,CTR CHEM TECHNOL,325 BROADWAY,BOULDER,CO 80303, USA. NR 11 TC 27 Z9 27 U1 0 U2 6 PU EATON PUBLISHING CO PI NATICK PA 154 E. CENTRAL ST, NATICK, MA 01760 SN 0736-6205 J9 BIOTECHNIQUES JI Biotechniques PD JUL PY 1991 VL 11 IS 1 BP 18 EP & PG 0 WC Biochemical Research Methods; Biochemistry & Molecular Biology SC Biochemistry & Molecular Biology GA FW821 UT WOS:A1991FW82100002 PM 1954011 ER PT J AU BRILL, RW BUSHNELL, PG AF BRILL, RW BUSHNELL, PG TI EFFECTS OF OPEN-SYSTEM AND CLOSED-SYSTEM TEMPERATURE-CHANGES ON BLOOD-OXYGEN DISSOCIATION CURVES OF SKIPJACK TUNA, KATSUWONUS-PELAMIS, AND YELLOWFIN TUNA, THUNNUS-ALBACARES SO CANADIAN JOURNAL OF ZOOLOGY-REVUE CANADIENNE DE ZOOLOGIE LA English DT Article ID ACID-BASE REGULATION; FISH HEMOGLOBINS; SALMO-GAIRDNERI; AMBIENT OXYGEN; RAINBOW-TROUT; BLUEFIN TUNA; HEAT; THERMOREGULATION; RESPONSES; EXCHANGE AB Tunas often experience rapid temperature changes of 10-degrees-C or more during their daily vertical movements. Their blood is therefore subjected to open-system (i.e., constant O2 and CO2 partial pressure, variable O2 and CO2 content) temperature changes during passage through the gills. In addition, tunas possess vascular countercurrent heat exchangers and can have deep red muscle temperatures as much as 20-degrees-C above ambient. Their blood also experiences closed-system (i.e., constant O2 and CO2 content, variable O2 and CO2 partial pressure) temperature changes during passage through the heat exchangers. Temperature-independent blood O2 binding could be expected. We found blood oxygen dissociation curves of skipjack tuna (Katsuwonus pelamis) and yellowfin tuna (Thunnus albacares) to be temperature independent during open-system temperature changes. Although blood from both species showed unsually large Bohr effects (-0.986 and -0.865 DELTA-log P50 . DELTA-pH-1 for skipjack and yellowfin tuna, respectively) when subjected to CO2 partial pressure alterations in the open system, the oxygen dissociation curves of skipjack tuna blood were nearly temperature independent during closed-system temperature changes. In other words, blood from skipjack tuna showed a reduced Bohr effect when subjected to the inevitable CO2 partial pressure changes that accompany closed-system temperature shifts. Since skipjack tuna blood shows temperature-independent O2 binding during closed-system temperature changes whereas yellowfin tuna blood does not, this unusual feature is not obligatory in thermoconserving fishes. C1 UNIV BRITISH COLUMBIA,DEPT ZOOL,VANCOUVER V6T 2A9,BC,CANADA. RP BRILL, RW (reprint author), NOAA,NATL MARINE FISHERIES SERV,SW FISHERIES SCI CTR,HONOLULU LAB,2570 DOLE ST,HONOLULU,HI 96822, USA. NR 53 TC 26 Z9 26 U1 1 U2 6 PU NATL RESEARCH COUNCIL CANADA PI OTTAWA PA RESEARCH JOURNALS, MONTREAL RD, OTTAWA ON K1A 0R6, CANADA SN 0008-4301 J9 CAN J ZOOL JI Can. J. Zool.-Rev. Can. Zool. PD JUL PY 1991 VL 69 IS 7 BP 1814 EP 1821 DI 10.1139/z91-250 PG 8 WC Zoology SC Zoology GA GP060 UT WOS:A1991GP06000011 ER PT J AU BRILL, RW BUSHNELL, PG AF BRILL, RW BUSHNELL, PG TI METABOLIC AND CARDIAC SCOPE OF HIGH-ENERGY DEMAND TELEOSTS, THE TUNAS SO CANADIAN JOURNAL OF ZOOLOGY-REVUE CANADIENNE DE ZOOLOGIE LA English DT Article; Proceedings Paper CT SYMP ON CARDIAC SCOPE IN LOWER VERTEBRATES CY MAY 03, 1990 CL SIMON FRASER UNIV, BURNABY, CANADA HO SIMON FRASER UNIV ID TROUT SALMO-GAIRDNERI; MYOCARDIAL OXYGEN-CONSUMPTION; PACIFIC BLUE MARLIN; WARM-BODIED FISH; RAINBOW-TROUT; THUNNUS-ALALUNGA; SKIPJACK TUNA; KATSUWONUS-PELAMIS; VENTRICULAR MYOCARDIUM; ALBACORE TUNA AB The maximum aerobic metabolic rates of tunas are far above those of other fishes. In this review we attempt to define features of the cardiovascular system that may account for this extreme performance. Tuna hearts are much larger than those of most other fishes and are half the mass of those of similarly sized mammals; however, the ratio of compact to spongy myocardium is not (except for one tuna species) higher than in other active teleosts. Myocardial aerobic enzyme activity levels are not significantly elevated. The cardiac outputs of spinally blocked skipjack tuna (Katsuwonus pelamis) and yellowfin tuna (Thunnus albacares) are roughly 4 times those of other active teleosts. Ventral aortic blood pressures are the highest among all fishes (more than twice those of rainbow trout (Oncorhynchus mykiss, formerly Salmo gairdneri), and appear to be due to a high resistance to blood flow in the gills, since dorsal aortic blood pressures are not exceptional. Heart rates, cardiac output, and ventilation volume are high, but gill ventilation and perfusion appear to be well matched (i.e., gill ventilation:perfusion conductance ratios of almost-equal-to 1). Blood hemoglobin concentrations of tunas are elevated, essentially identical with those of humans and twice those seen in other fishes. Because their blood oxygen carrying capacity is high and because skipjack and yellowfin tunas appear to be able to increase the minimum observed arterial to venous oxygen content differnces approximately 3 times, we predict that they need to increase cardiac output only about 2 times during maximum rates of oxygen uptake. This ratio is not very different from those of other teleosts. C1 UNIV BRITISH COLUMBIA,DEPT ZOOL,VANCOUVER V6T 2A9,BC,CANADA. RP BRILL, RW (reprint author), NOAA,NATL MARINE FISHERIES SERV,SW FISHERIES SCI CTR,HONOLULU LAB,2570 DOLE ST,HONOLULU,HI 96822, USA. NR 90 TC 54 Z9 54 U1 1 U2 11 PU NATL RESEARCH COUNCIL CANADA PI OTTAWA PA RESEARCH JOURNALS, MONTREAL RD, OTTAWA ON K1A 0R6, CANADA SN 0008-4301 J9 CAN J ZOOL JI Can. J. Zool.-Rev. Can. Zool. PD JUL PY 1991 VL 69 IS 7 BP 2002 EP 2009 DI 10.1139/z91-279 PG 8 WC Zoology SC Zoology GA GP060 UT WOS:A1991GP06000040 ER PT J AU SHERN, RJ MIRTH, DB BARTKIEWICZ, A MONELLTORRENS, E LI, SH CHOW, LC AF SHERN, RJ MIRTH, DB BARTKIEWICZ, A MONELLTORRENS, E LI, SH CHOW, LC TI EFFECTS OF AN ACIDIC CALCIUM-PHOSPHATE SOLUTION AND THE INTRAORAL FLUORIDE-RELEASING DEVICE ON DENTAL-CARIES AND FLUORIDE UPTAKE IN RATS SO CARIES RESEARCH LA English DT Article DE CALCIUM PHOSPHATE SOLUTION; FLUORIDE-RELEASING DEVICE; RAT CARIES; FLUORIDE UPTAKE ID TOOTH ENAMEL; PLAQUE; CAHPO4.2H2O; INHIBITION; RINSES; MOLARS; PH AB This investigation comprised two studies evaluating the effects of an acidic calcium phosphate solution (CPS) on fluoride uptake in the enamel, glycolysis of dental plaque, the incidence of dental caries and urinary fluoride concentrations of rats wearing an intraoral fluoride-releasing device (IFRD). In the first study, CPS-fluoride treatment preceded the cariogenic challenge. In the second study, the cariogenic challenge preceded the treatments. In the first study, CPS treatments increased the ability of enamel to bind fluoride. However, the enamel-bound fluoride exerted a negligible effect on plaque glycolysis as measured by the pH decrease after sucrose challenge. In the second study CPS augmented the caries inhibition for both the sulcal-morsal and buccal-lingual surfaces. In both studies the IFRD significantly restricted the development of carious enamel on the sulcal-morsal surfaces and caused elevated concentrations of fluoride in the urine independent of CPS treatments. C1 NATL INST STAND & TECHNOL,PAFFENBARGER RES CTR,AMER DENT ASSOC HLTH FDN,GAITHERSBURG,MD. RP SHERN, RJ (reprint author), NIDR,CLIN INVEST & PATIENT CARE BRANCH,BLDN 10,ROOM 1N114,BETHESDA,MD 20892, USA. NR 25 TC 3 Z9 3 U1 0 U2 1 PU KARGER PI BASEL PA ALLSCHWILERSTRASSE 10, CH-4009 BASEL, SWITZERLAND SN 0008-6568 J9 CARIES RES JI Caries Res. PD JUL-AUG PY 1991 VL 25 IS 4 BP 268 EP 276 PG 9 WC Dentistry, Oral Surgery & Medicine SC Dentistry, Oral Surgery & Medicine GA GD301 UT WOS:A1991GD30100005 PM 1913764 ER PT J AU RAO, KSMSR SZLAG, DS SIKDAR, SK JOSHI, JB SAWANT, SB AF RAO, KSMSR SZLAG, DS SIKDAR, SK JOSHI, JB SAWANT, SB TI PROTEIN EXTRACTION IN A SPRAY COLUMN USING A POLYETHYLENE-GLYCOL MALTODEXTRIN 2-PHASE POLYMER SYSTEM SO CHEMICAL ENGINEERING JOURNAL AND THE BIOCHEMICAL ENGINEERING JOURNAL LA English DT Article AB Protein recovery, with bovine serum albumin (BSA) as a model, was performed in a laboratory spray column using inexpensive aqueous two-phase systems. A light phase rich in polyethylene glycol (PEG) was steadily dispersed into a heavy continuous phase containing maltodextrin (MDX). The PEG phase holdup and BSA mass transfer coefficients were measured in spray columns with internal diameters of 22 and 33 mm, using several sparger designs. The overall BSA mass transfer coefficients were greater in the PEG-maltodextrin systems than those encountered in PEG-dextran systems with similar BSA partition coefficients. Empirical correlations are proposed for mass transfer coefficients and PEG phase holdup. C1 NATL INST STAND & TECHNOL,CTR CHEM TECHNOL,BOULDER,CO 80303. RI Joshi, Jyeshtharaj /A-4941-2009 NR 10 TC 4 Z9 4 U1 1 U2 2 PU ELSEVIER SCIENCE SA LAUSANNE PI LAUSANNE 1 PA PO BOX 564, 1001 LAUSANNE 1, SWITZERLAND SN 0923-0467 J9 CHEM ENG J BIOCH ENG JI Chem. Eng. J. Biochem. Eng. J. PD JUL PY 1991 VL 46 IS 3 BP B75 EP B81 DI 10.1016/0300-9467(91)87008-X PG 7 WC Engineering, Chemical SC Engineering GA GA685 UT WOS:A1991GA68500007 ER PT J AU STOREY, PJ HUMMER, DG AF STOREY, PJ HUMMER, DG TI FAST COMPUTER EVALUATION OF RADIATIVE PROPERTIES OF HYDROGENIC SYSTEMS SO COMPUTER PHYSICS COMMUNICATIONS LA English DT Article DE HYDROGENIC RADIATIVE TRANSITIONS; EINSTEIN COEFFICIENTS; PHOTOIONIZATION; FREE-FREE; GAUNT FACTORS AB Three subroutines are described for the very fast calculation of bound-bound, bound-free, and free-free cross-sections for nonrelativistic hydrogenic systems of arbitrary nuclear charge and reduced mass. The first two are essentially exact, being based on recursion relations which are known to be stable. The third evaluates the thermally-averaged free-free Gaunt factor by means of a two-dimensional Chebyshev expansion calculated by numerical evaluation of the cross-sections expressed as hypergeometric functions, augmented by other analytical approximations. C1 UNIV COLORADO,JOINT INST LAB ASTROPHYS,BOULDER,CO 80309. NATL INST STAND & TECHNOL,DIV QUANTUM PHYS,BOULDER,CO 80309. RP STOREY, PJ (reprint author), UNIV LONDON UNIV COLL,DEPT PHYS & ASTRON,LONDON WC1E 6BT,ENGLAND. NR 11 TC 58 Z9 58 U1 1 U2 2 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0010-4655 J9 COMPUT PHYS COMMUN JI Comput. Phys. Commun. PD JUL PY 1991 VL 66 IS 1 BP 129 EP 141 DI 10.1016/0010-4655(91)90013-B PG 13 WC Computer Science, Interdisciplinary Applications; Physics, Mathematical SC Computer Science; Physics GA FZ569 UT WOS:A1991FZ56900012 ER PT J AU FULTZ, ML DURST, RA AF FULTZ, ML DURST, RA TI ELECTROCHEMICAL AND SPECTROELECTROCHEMICAL STUDY OF COPPER BLEOMYCIN COMPLEXES SO ELECTROANALYSIS LA English DT Article ID THIN-LAYER ELECTRODE; CHEMISTRY AB The electrochemical behavior of the copper(II) complex of bleomycin, a glycopeptide antibiotic with antitumor activity, was investigated in several buffer systems using cyclic voltammetry, polarography, coulometry, and spectroelectrochemistry. The copper bleomycin complex exhibited irreversible one-electron reduction on glassy carbon and mercury electrodes and was electroinactive on platinum, gold, and silver. After the initial reduction process on mercury, the appearance of the Cu(0)/(II) redox couple indicated dissociation of the complex and subsequent reduction of the Cu(I) to the metal. In the presence of excess bleomycin, the Cu(II) reoxidized from the mercury electrode is rapidly complexed and no copper reduction process is observed. On glassy carbon, however, the Cu(I) bleomycin complex is stable and does not undergo further reduction, as demonstrated by spectroelectrochemistry at a reticulated vitreous carbon optically transparent electrode. Consequently, as with many metallo-organic redox processes, there appear to be several possible electrochemical pathways depending on the pH, the electrode materials, and the experimental time domain. C1 NATL INST STAND & TECHNOL,CTR ANALYT CHEM,GAITHERSBURG,MD 20899. NR 22 TC 2 Z9 2 U1 0 U2 0 PU VCH PUBLISHERS INC PI DEERFIELD BEACH PA 303 NW 12TH AVE, DEERFIELD BEACH, FL 33442-1788 SN 1040-0397 J9 ELECTROANAL JI Electroanalysis PD JUL PY 1991 VL 3 IS 6 BP 519 EP 526 DI 10.1002/elan.1140030612 PG 8 WC Chemistry, Analytical; Electrochemistry SC Chemistry; Electrochemistry GA FZ240 UT WOS:A1991FZ24000010 ER PT J AU BAIRD, TA RYER, CH OLLA, BL AF BAIRD, TA RYER, CH OLLA, BL TI SOCIAL ENHANCEMENT OF FORAGING ON AN EPHEMERAL FOOD SOURCE IN JUVENILE WALLEYE POLLOCK, THERAGRA-CHALCOGRAMMA SO ENVIRONMENTAL BIOLOGY OF FISHES LA English DT Note DE FEEDING; GROUPING; SOCIAL FACILITATION; AREA COPYING; LOCAL ENHANCEMENT; INFORMATION TRANSFER; FISH; GADIDAE ID FEEDING-BEHAVIOR; FISH AB The foraging effectiveness of walleye pollock juveniles, Theragra chalcogramma, was determined experimentally to test the hypothesis that social cues may facilitate the ability of individuals to exploit ephemeral food patches. Fish were tested when isolated, paired with one other fish, and in a group of six fish. Test fish exploited more food patches while in a group of six than when they were isolated. Patch exploitation by paired fish was intermediate to but not statistically different than isolate or grouped treatments. The number of pellets eaten by test fish in a group and a pair was more than 3.5 times that of when they were isolated, although the overall relationship between the amount of food eaten and group size was not statistically significant. Results support the hypothesis that juvenile walleye pollock exploit ephemeral food patches more effectively in the presence of conspecifics. In planktivores such as walleye pollock, social cues may enhance foraging on transient food sources either by facilitating detection of food patches (local enhancement) or by stimulating foraging activity when a food patch is located (social facilitation). C1 OREGON STATE UNIV,HATFIELD MARINE SCI CTR,NEWPORT,OR 97365. NOAA,ALASKA FISHERIES SCI CTR,COOPERAT INST MARINE RESOURCES STUDIS,HATFIELD MARINE SCI CTR,NEWPORT,OR 97365. NR 16 TC 43 Z9 43 U1 2 U2 13 PU KLUWER ACADEMIC PUBL PI DORDRECHT PA SPUIBOULEVARD 50, PO BOX 17, 3300 AA DORDRECHT, NETHERLANDS SN 0378-1909 J9 ENVIRON BIOL FISH JI Environ. Biol. Fishes PD JUL PY 1991 VL 31 IS 3 BP 307 EP 311 DI 10.1007/BF00000697 PG 5 WC Ecology; Marine & Freshwater Biology SC Environmental Sciences & Ecology; Marine & Freshwater Biology GA FV721 UT WOS:A1991FV72100010 ER PT J AU AU, DW AF AU, DW TI POLYSPECIFIC NATURE OF TUNA SCHOOLS - SHARK, DOLPHIN, AND SEABIRD ASSOCIATES SO FISHERY BULLETIN LA English DT Article ID EASTERN TROPICAL PACIFIC; THUNNUS-ALBACARES; STOMACH CONTENTS; FORAGING FLOCKS; YELLOWFIN TUNA; CONSEQUENCES; LIFE AB Yellowfin tuna Thunnus albacares are commonly found associated with other species, especially sharks, birds, and dolphins, in the eastern tropical Pacific. Data from the purse seine fishery there, collected during 1974 and 1975, indicate that sharks occurred with tuna in 40% or more of the purse seine sets made around floating logs. Most other species, including rays, billfish, and small tunas, usually occurred in less than 10% of the sets. The association rate of these bycatch species declined progressively from log- to school- to porpoise-associated sets. This, together with their behavior as understood, suggests that at least some of these species stay with the tuna as much as they can. Such behavior would be like that of polyspecific associations in which two or more species travel together for foraging and protective advantages. RP AU, DW (reprint author), NATL MARINE FISHERIES SERV,SW FISHERIES SCI CTR,LA JOLLA LAB,POB 271,LA JOLLA,CA 92038, USA. NR 30 TC 31 Z9 32 U1 0 U2 3 PU NATL MARINE FISHERIES SERVICE SCIENTIFIC PUBL OFFICE PI SEATTLE PA 7600 SAND POINT WAY NE BIN C15700, SEATTLE, WA 98115 SN 0090-0656 J9 FISH B-NOAA JI Fish. Bull. PD JUL PY 1991 VL 89 IS 3 BP 343 EP 354 PG 12 WC Fisheries SC Fisheries GA GE375 UT WOS:A1991GE37500001 ER PT J AU FORNEY, KA HANAN, DA BARLOW, J AF FORNEY, KA HANAN, DA BARLOW, J TI DETECTING TRENDS IN HARBOR PORPOISE ABUNDANCE FROM AERIAL SURVEYS USING ANALYSIS OF COVARIANCE SO FISHERY BULLETIN LA English DT Article ID STATISTICAL POWER ANALYSIS; COMMUNITY-WIDE PATTERNS; PHOCOENA-PHOCOENA; CALIFORNIA; WASHINGTON; OREGON AB Aerial surveys designed to detect trends in the abundance of harbor porpoise Phocoena phocoena were conducted each autumn, 1986 through 1990. The number of porpoise seen per kilometer of survey effort was used as an index of abundance. Based on these surveys, an analysis of covariance was used to model porpoise abundance. Year was treated as a covariate, and factors which affected sighting rates were included as categorical variables. No significant changes were seen in the abundance of porpoise over the five survey years. Monte Carlo simulations were performed to determine the power of the ANCOVA to detect trends in abundance. We conclude that the ability to detect trends is poor if traditional levels of statistical significance (alpha = 0.05) are used. A larger alpha-error may be appropriate in the management context of this species and increases the power to detect trends. Additional survey years similarly improve the power to detect trends. Based on the results of the simulations, we suggest that power should be defined to include only the detection of the correct trend when two-tailed tests are employed. RP FORNEY, KA (reprint author), NATL MARINE FISHERIES SERV,SW FISHERIES SCI CTR,LA JOLLA LAB,CALIF DEPT FISH & GAME,POB 271,LA JOLLA,CA 92038, USA. NR 25 TC 28 Z9 32 U1 0 U2 1 PU NATL MARINE FISHERIES SERVICE SCIENTIFIC PUBL OFFICE PI SEATTLE PA 7600 SAND POINT WAY NE BIN C15700, SEATTLE, WA 98115 SN 0090-0656 J9 FISH B-NOAA JI Fish. Bull. PD JUL PY 1991 VL 89 IS 3 BP 367 EP 377 PG 11 WC Fisheries SC Fisheries GA GE375 UT WOS:A1991GE37500003 ER PT J AU KLEIBER, P PERRIN, C AF KLEIBER, P PERRIN, C TI CATCH-PER-EFFORT AND STOCK STATUS IN THE UNITED-STATES NORTH PACIFIC ALBACORE FISHERY - REAPPRAISAL OF BOTH SO FISHERY BULLETIN LA English DT Article AB On reexamining a routine procedure for reporting catch-per-effort (CPE) in the North Pacific albacore fishery, we found evidence that CPE as an index of population size has been subject to a changing degree of bias. The increasing, positive bias in the routinely reported CPE has produced an optimistic, upward trend in this population index during the past decade. A time series of CPE, calculated in a different way, trends downwards. We show that both time series are subject to increasing, positive bias under conditions of an increasing ability of fishermen to locate concentrated patches of albacore. We present evidence that this ability has grown over the past decade, possibly as a result of increasing availability of satellite-based fishing advisories. The divergence of the two time series is explained by a model that shows a different rate of increase in bias in the two cases. The fact that the bias is increasing in the new time series implies that the true population has undergone a more severe decline than is shown by that series. RP KLEIBER, P (reprint author), NATL MARINE FISHERIES SERV,SW FISHERIES SCI CTR,LA JOLLA LAB,POB 271,LA JOLLA,CA 92038, USA. NR 14 TC 5 Z9 6 U1 0 U2 0 PU NATL MARINE FISHERIES SERVICE SCIENTIFIC PUBL OFFICE PI SEATTLE PA 7600 SAND POINT WAY NE BIN C15700, SEATTLE, WA 98115 SN 0090-0656 J9 FISH B-NOAA JI Fish. Bull. PD JUL PY 1991 VL 89 IS 3 BP 379 EP 386 PG 8 WC Fisheries SC Fisheries GA GE375 UT WOS:A1991GE37500004 ER PT J AU PEARSON, DE HIGHTOWER, JE CHAN, JTH AF PEARSON, DE HIGHTOWER, JE CHAN, JTH TI AGE, GROWTH, AND POTENTIAL YIELD FOR SHORTBELLY ROCKFISH SEBASTES-JORDANI SO FISHERY BULLETIN LA English DT Article ID YELLOWTAIL ROCKFISH; NATURAL MORTALITY; CALIFORNIA; LONGEVITY; OREGON AB Shortbelly rockfish Sebastes jordani is an abundant species that could support a large commercial fishery off central California. Prior studies of shortbelly rockfish growth were based on age data obtained from scales or whole otoliths. We show that broken and burnt otoliths provide reliable ages that are substantially different than those derived from previous methods. This new information was used to update estimates of the von Bertalanffy growth curve parameters, the natural mortality rate, and potential yield. We found that shortbelly rockfish live for up to 22 years. Males grew more slowly and reached a smaller maximum size than females. Estimates of natural mortality from three predictive models ranged from 0.212 to 0.378 for males and 0.203 to 0.437 for females. Assuming M is 0.20-0.35 and using biomass estimates from hydroacoustic surveys, we estimated that potential yield in the Ascension Canyon-Farallon Islands area ranges from 13,400 to 23,500 metric tons. RP PEARSON, DE (reprint author), NATL MARINE FISHERIES SERV,SW FISHERIES SCI CTR,TIBURON LAB,3150 PARADISE DR,TIBURON,CA 94920, USA. NR 37 TC 17 Z9 18 U1 0 U2 3 PU NATL MARINE FISHERIES SERVICE SCIENTIFIC PUBL OFFICE PI SEATTLE PA 7600 SAND POINT WAY NE BIN C15700, SEATTLE, WA 98115 SN 0090-0656 J9 FISH B-NOAA JI Fish. Bull. PD JUL PY 1991 VL 89 IS 3 BP 403 EP 409 PG 7 WC Fisheries SC Fisheries GA GE375 UT WOS:A1991GE37500006 ER PT J AU PERRIN, WF AKIN, PA KASHIWADA, JV AF PERRIN, WF AKIN, PA KASHIWADA, JV TI GEOGRAPHIC-VARIATION IN EXTERNAL MORPHOLOGY OF THE SPINNER DOLPHIN STENELLA-LONGIROSTRIS IN THE EASTERN PACIFIC AND IMPLICATIONS FOR CONSERVATION SO FISHERY BULLETIN LA English DT Article ID TROPICAL PACIFIC; REPRODUCTION; GROWTH AB Variation in color pattern, dorsal fin shape, and body length exhibit sharp north/south gradients centered at about 5-10-degrees-N latitude and east/west gradients at about 120-125-degrees-W longitude. A conservation zone with boundaries in these regions would provide protection for the morphologically unique eastern spinner dolphin Stenella longirostris orientalis. A radial pattern of geographic variation in the eastern Pacific and a complex pattern of discordant variation outside the core range of S. l. orientalis suggest that the present separate management of "whitebelly" spinner dolphins (which comprise a broad zone of hybridization/intergradation between S. l. orientalis to the east and the pantropical spinner dolphin S. l. longirostris to the west and southwest) north and south of the Equator may not be justified on the grounds of conservation of distinct populations. RP PERRIN, WF (reprint author), NATL MARINE FISHERIES SERV,SW FISHERIES SCI CTR,LA JOLLA LAB,POB 271,LA JOLLA,CA 92038, USA. NR 27 TC 29 Z9 29 U1 1 U2 4 PU NATL MARINE FISHERIES SERVICE SCIENTIFIC PUBL OFFICE PI SEATTLE PA 7600 SAND POINT WAY NE BIN C15700, SEATTLE, WA 98115 SN 0090-0656 J9 FISH B-NOAA JI Fish. Bull. PD JUL PY 1991 VL 89 IS 3 BP 411 EP 428 PG 18 WC Fisheries SC Fisheries GA GE375 UT WOS:A1991GE37500007 ER PT J AU PRINCE, ED LEE, DW ZWEIFEL, JR BROTHERS, EB AF PRINCE, ED LEE, DW ZWEIFEL, JR BROTHERS, EB TI ESTIMATING AGE AND GROWTH OF YOUNG ATLANTIC BLUE MARLIN MAKAIRA-NIGRICANS FROM OTOLITH MICROSTRUCTURE SO FISHERY BULLETIN LA English DT Article ID THUNNUS-THYNNUS; FISH OTOLITHS; VALIDATION; INCREMENTS; MODELS; LARVAL; ZONES; TUNA AB Otolith microstructure analysis was applied to sagittae from 18 larvae (5-10 mm notochord length) and 77 juvenile, young adult, and adult (4.3-212 cm lower jaw fork length, LJFL) Atlantic blue marlin Makaira nigricans for estimation of age and growth rate. Contingency table analyses indicated that a periodicity of one increment per day was most consistent with the seasonal distribution and peaks of back-calculated spawning dates of the aged samples (May to November), and with information on spawning reported in the literature. Microstructural features of larval blue marlin sagittae were indistinguishable from those in the otoliths of other tropical pelagic species where conclusive age validation has verified daily increment deposition rates. Average percent error of the counting method (precision) for the aged samples of juveniles and young adults/adults was 1.6%. Estimated ages of larvae ranged from 9 to 12 days while estimated ages of juveniles, young adults, and adults ranged from 21 to 495 days (1.4 years). Otolith microstructure analysis could not be applied with confidence to blue marlin older than 1.4 years. Allometric equations for the length-weight relationship of immature (less-than-or-equal-to 140 cm LJFL) and mature male and female blue marlin (> 140 cm) are presented. Sexual dimorphic growth (weight only) in Atlantic blue marlin appears to begin at 140 cm LJFL. Both the maximum (approximately 16 mm/day at 50 days) and sustained (approximately 10 mm/day) growth rates in length during the first 100 days indicate that Atlantic blue marlin are one of the fastest growing of all teleosts in the early stages of development. An attempt to determine the periodicity of presumed annual marks on otoliths from adult blue marlin (213-367 cm LJFL) by evaluating microstructural characteristics and increment counts between annuli was unsuccessful. C1 EFS CONSULTANTS,ITHACA,NY 14850. RP PRINCE, ED (reprint author), NATL MARINE FISHERIES SERV,SE FISHERIES SCI CTR,MIAMI LAB,MIAMI,FL 33149, USA. NR 48 TC 47 Z9 48 U1 0 U2 11 PU NATL MARINE FISHERIES SERVICE SCIENTIFIC PUBL OFFICE PI SEATTLE PA 7600 SAND POINT WAY NE BIN C15700, SEATTLE, WA 98115 SN 0090-0656 J9 FISH B-NOAA JI Fish. Bull. PD JUL PY 1991 VL 89 IS 3 BP 441 EP 459 PG 19 WC Fisheries SC Fisheries GA GE375 UT WOS:A1991GE37500009 ER PT J AU SMITH, MK KOSTLAN, E AF SMITH, MK KOSTLAN, E TI ESTIMATES OF AGE AND GROWTH OF EHU ETELIS-CARBUNCULUS IN 4 REGIONS OF THE PACIFIC FROM DENSITY OF DAILY INCREMENTS IN OTOLITHS SO FISHERY BULLETIN LA English DT Article ID PRISTIPOMOIDES-FILAMENTOSUS; HAWAIIAN SNAPPER; LARVAL; STOCKS; WATERS; FISH AB Growth of the deep slope snapper Etelis carbunculus was evaluated from the density of daily increments in sagittal otoliths collected from Hawaii, the Commonwealth of the Northern Marianas Islands (NMI), French Polynesia, and Vanuatu. The rate of otolith growth (mu-m/day) as a function of otolith radius was fit by regression to a modified Gompertz rate curve and the age of fish estimated by integrating the equation. There were slight regional differences between the estimated values of each of the three otolith growth rate parameters, which may be attributable in part to random sampling differences. However, integrated estimates of fish age versus otolith radius varied little between sites because of the compensatory relationship between two of the three estimated parameters which together determine the rate of dampening of the otolith growth function. There were significant regional differences in average otolith radius, and thus in estimated age, as a function of fish length. Fish from Vanuatu and NMI were younger at a given length than those from the other two regions. However, fish as large as those at Vanuatu are not found at NMI, suggesting there may be regional differences in mortality. Regional age-at-length data were fit to a von Bertalanffy growth curve, both unconstrained and held to a value of asymptotic length (L infinity) obtained from the literature. Estimates of natural mortality for each region are discussed, based on the regional values obtained for the von Bertalanffy growth constant (K). These results should be confirmed using data obtained from a wider range of fish sizes. C1 NATL MARINE FISHERIES SERV,SW FISHERIES SCI CTR,HONOLULU LAB,HONOLULU,HI 96822. UNIV HAWAII,DEPT MATH,HONOLULU,HI 96822. NR 47 TC 29 Z9 29 U1 0 U2 1 PU NATL MARINE FISHERIES SERVICE SCIENTIFIC PUBL OFFICE PI SEATTLE PA 7600 SAND POINT WAY NE BIN C15700, SEATTLE, WA 98115 SN 0090-0656 J9 FISH B-NOAA JI Fish. Bull. PD JUL PY 1991 VL 89 IS 3 BP 461 EP 472 PG 12 WC Fisheries SC Fisheries GA GE375 UT WOS:A1991GE37500010 ER PT J AU STEHLIK, LL MACKENZIE, CL MORSE, WW AF STEHLIK, LL MACKENZIE, CL MORSE, WW TI DISTRIBUTION AND ABUNDANCE OF 4 BRACHYURAN CRABS ON THE NORTHWEST ATLANTIC SHELF SO FISHERY BULLETIN LA English DT Article ID CANCER-IRRORATUS-SAY; ROCK CRAB; SEASONAL COMPOSITION; UNITED-STATES; BIOLOGY; BIGHT; REPRODUCTION; DECAPODA AB Seasonal distributions and relative abundances of the Atlantic rock crab Cancer irroratus, Jonah crab C. borealis, northern lady crab Ovalipes ocellatus, and coarsehand lady crab O. stephensoni were determined from fish trawl and clam dredge surveys on the continental shelf from Nova Scotia to Cape Hatteras, North Carolina during 1978-87. Rock crabs have the broadest distribution, which includes coastal waters of the Gulf of Maine and depths of 6-456 m from Georges Bank to Cape Hatteras. Jonah crabs are more widely distributed in the Gulf of Maine and on Georges Bank than rock crabs. They occur most frequently in the northern and offshore zones of the middle Atlantic from south of Georges Bank to off Delaware, at depths to over 400 m. Northern lady crabs occur primarily in the inner strata of the middle-Atlantic shelf in depths < 27 m, and on shallower portions of Georges Bank. Coarsehand lady crabs occur from southern New Jersey to Cape Hatteras, to over 200 m. Cancer spp. occur mainly at 3-18-degrees-C, while Ovalipes spp. occur mainly at 11-24-degrees-C. Sex ratios in rock and Jonah crab catches deviated from 1:1 by season and gear; males dominate in spring trawl surveys, females in summer dredge and fall trawl surveys. Trawl catches of all species were significantly larger at night or twilight than during the day, suggesting more nocturnal activity. Temperature, depth, and their interaction significantly affected the catches of these crabs. RP STEHLIK, LL (reprint author), NATL MARINE FISHERIES SERV,NE FISHERIES SCI CTR,SANDY HOOK LAB,HIGHLANDS,NJ 07732, USA. NR 38 TC 28 Z9 30 U1 1 U2 6 PU NATL MARINE FISHERIES SERVICE SCIENTIFIC PUBL OFFICE PI SEATTLE PA 7600 SAND POINT WAY NE BIN C15700, SEATTLE, WA 98115 SN 0090-0656 J9 FISH B-NOAA JI Fish. Bull. PD JUL PY 1991 VL 89 IS 3 BP 473 EP 492 PG 20 WC Fisheries SC Fisheries GA GE375 UT WOS:A1991GE37500011 ER PT J AU SUDEKUM, AE PARRISH, JD RADTKE, RL RALSTON, S AF SUDEKUM, AE PARRISH, JD RADTKE, RL RALSTON, S TI LIFE-HISTORY AND ECOLOGY OF LARGE JACKS IN UNDISTURBED, SHALLOW, OCEANIC COMMUNITIES SO FISHERY BULLETIN LA English DT Article ID FRENCH FRIGATE SHOALS; CORAL-REEF ECOSYSTEM; PRISTIPOMOIDES-FILAMENTOSUS; HAWAIIAN SNAPPER; FISHES; OTOLITHS; PATTERNS; ISLANDS; MODEL; AGE AB The large jack species Caranx ignobilis and Caranx melampygus were collected from the nearly pristine shallow waters of the atolls, reefs, and shoals of the Northwestern Hawaiian Islands. Both species were aged by counting daily otolith increments and validating frequency of otolith deposition by marking captive fish with tetracycline. Growth for each species was well described by a von Bertalanffy relationship. Measured growth of captive C. melampygus was also in agreement. Gravid fish of both species were found only in April-November; peak spawning season for both was about May-August. Reproduction began at approximately 350 mm SL (approximately 2 years old) in C. melampygus and at approximately 600 mm SL (approximately 3 1/2 years old) in C. ignobilis. Fecundity of female C. melampygus varied approximately as the 1.7 power of body weight. Both species were > 90% piscivorous, as judged from combined volume and number of prey and incidence of predation. Crustaceans and cephalopods comprised several percent of the diet of C. ignobilis; both groups were present but less important in C. melampygus. Both jack species ate gastropods in trace amounts. The overall diet of the two species showed moderate overlap: "Pianka's" index of overlap, A(yz) = 0.42. The rate of food consumption for captive C. melampygus was used to estimate the respiratory metabolic coefficient, which in turn was used to estimate respiratory demands for all size-classes of both species. The von Bertalanffy model predicted growth energy, and reproductive energy was estimated from values of the gonadosomatic index. These energy terms were combined to calculate the food consumption required to sustain all size-classes appearing in local catch data. This distribution can be represented by a composite individual for each species consuming a little less than 50 kg/year (C. melampygus) and about 150 kg/year (C. ignobilis). Rough population estimates indicated that at one well-studied atoll, the two species populations combined may eat over 30,000 metric tons of prey per year. These results suggest a quantitatively important trophic role for these top-level carangid predators. C1 UNIV HAWAII,US FISH & WILDLIFE SERV,HAWAII COOPERAT FISHERY RES UNIT,HONOLULU,HI 96822. UNIV HAWAII,SCH OCEAN & EARTH SCI & TECHNOL,HONOLULU,HI 96822. NATL MARINE FISHERIES SERV,SW FISHERIES SCI CTR,TIBURON LAB,TIBURON,CA 94920. RP SUDEKUM, AE (reprint author), STANFORD UNIV HOSP,DEPT SURG,300 PASTEUR DR,STANFORD,CA 94305, USA. NR 59 TC 64 Z9 69 U1 1 U2 18 PU NATL MARINE FISHERIES SERVICE SCIENTIFIC PUBL OFFICE PI SEATTLE PA 7600 SAND POINT WAY NE BIN C15700, SEATTLE, WA 98115 SN 0090-0656 J9 FISH B-NOAA JI Fish. Bull. PD JUL PY 1991 VL 89 IS 3 BP 493 EP 513 PG 21 WC Fisheries SC Fisheries GA GE375 UT WOS:A1991GE37500012 ER PT J AU VECCHIONE, M AF VECCHIONE, M TI OBSERVATIONS ON THE PARALARVAL ECOLOGY OF A EURYHALINE SQUID LOLLIGUNCULA-BREVIS (CEPHALOPODA, LOLIGINIDAE) SO FISHERY BULLETIN LA English DT Article ID BOTTOM WATER; HYPOXIA; ZOOPLANKTON; ESTUARY; SHELF; BAY AB Cephalopods were examined from more than 3000 zooplankton samples collected over a two-year period from coastal and estuarine waters of southwest Louisiana. In total, 270 cephalopods were taken in 164 of these samples; 267 specimens from 161 samples were Lolliguncula brevis. They were found in coastal waters from April through January, but in estuarine waters only in May, July, and August. Maximum standardized abundance was found in the nearbottom waters of the estuary in May. Overall, paralarval L. brevis were most often collected nearbottom in inshore coastal waters during May-June. This species was not collected in the estuary at salinities below 27 x 10(-3). Although they were found in coastal waters with lower salinities (22 x 10(-3), abundance was generally greatest in waters with salinities of about 26 x 10(-3). Somewhat surprisingly, paralarval L. brevis were collected throughout the range of dissolved oxygen concentrations sampled, including waters considered to be hypoxic, with < 2 mL/L dissolved oxygen. Contents of the digestive tract were examined in 50 paralarvae; 18% of these contained solid food while others were inflated with a semiliquid mush or clear liquid. RP VECCHIONE, M (reprint author), NATL MUSEUM NAT HIST,NATL MARINE FISHERIES SERV,SYSTEMAT LAB,WASHINGTON,DC 20560, USA. NR 28 TC 21 Z9 23 U1 0 U2 1 PU NATL MARINE FISHERIES SERVICE SCIENTIFIC PUBL OFFICE PI SEATTLE PA 7600 SAND POINT WAY NE BIN C15700, SEATTLE, WA 98115 SN 0090-0656 J9 FISH B-NOAA JI Fish. Bull. PD JUL PY 1991 VL 89 IS 3 BP 515 EP 521 PG 7 WC Fisheries SC Fisheries GA GE375 UT WOS:A1991GE37500013 ER PT J AU WOODBURY, D RALSTON, S AF WOODBURY, D RALSTON, S TI INTERANNUAL VARIATION IN GROWTH-RATES AND BACK-CALCULATED BIRTH-DATE DISTRIBUTIONS OF PELAGIC JUVENILE ROCKFISHES (SEBASTES SPP) OFF THE CENTRAL CALIFORNIA COAST SO FISHERY BULLETIN LA English DT Article ID CLUPEA-HARENGUS; LARVAL; FISHES; INCREMENTS; OTOLITHS; BANK; AGE AB Young-of-the-year pelagic juvenile rockfish (genus Sebastes) were collected during annual surveys in the spring and early summer, 1983-88, off the central California coast. Growth rates and back-calculated birthdate distributions of five species (shortbelly rockfish S. jordani, bocaccio S. paucispinis, chilipepper S. goodei, widow rockfish S. entomelas, and yellowtail rockfish S. flavidus) were estimated from daily otolith increments. Interspecific variation in growth rates was evident, with bocaccio exhibiting the fastest growth (0.56-0.97 mm/day) and yellowtail rockfish growing slowest (0.19-0.46 mm/day). Growth rates of all species varied among years. Comparisons of annual growth performance, measured by predicting standard length at a selected standard age, revealed strong positive interannual covariation among the five species studied; in general, growth was relatively good in 1987 and was poor in 1985. Back-calculated birthdate distributions also revealed strong positive interannual covariation among these species; most distributions were unimodal. The years 1985 and 1988 were characterized by distributions that were centered early in the year; whereas in 1986 (and possibly in 1983) these distributions occurred later. RP WOODBURY, D (reprint author), NATL MARINE FISHERIES SERV,SW FISHERIES SCI CTR,TIBURON LAB,3150 PARADISE DR,TIBURON,CA 94920, USA. NR 38 TC 40 Z9 43 U1 1 U2 10 PU NATL MARINE FISHERIES SERVICE SCIENTIFIC PUBL OFFICE PI SEATTLE PA 7600 SAND POINT WAY NE BIN C15700, SEATTLE, WA 98115 SN 0090-0656 J9 FISH B-NOAA JI Fish. Bull. PD JUL PY 1991 VL 89 IS 3 BP 523 EP 533 PG 11 WC Fisheries SC Fisheries GA GE375 UT WOS:A1991GE37500014 ER PT J AU HERBERT, TD SARMIENTO, JL AF HERBERT, TD SARMIENTO, JL TI OCEAN NUTRIENT DISTRIBUTION AND OXYGENATION - LIMITS ON THE FORMATION OF WARM SALINE BOTTOM WATER OVER THE PAST 91 MY SO GEOLOGY LA English DT Article ID TEMPERATURE; HISTORY; MODEL AB It has been proposed that deep-water formation in the oceans would be quite different during geologic intervals with reduced equator to pole temperature gradients. Salinity, rather than temperature, differences might drive the deep-ocean circulation. Saline water would tend to form at subtropical latitudes where evaporation exceeds precipitation. We point out a likely consequence of warm saline bottom-water formation on ocean chemistry-the tendency to drive the ocean toward anoxia. This effect is not due to the previously noted lower oxygen solubility with increasing ocean temperature, but rather to the increased efficiency with which plankton will extract nutrients from convecting waters at low latitudes. The present ocean nutrient content is sufficient to induce deep-water anoxia if circulation were to change, yet anoxia is rare in the paleoceanographic record. A simple ocean chemical model makes explicit the tradeoffs between mean ocean nutrient content and circulation parameters that will satisfy the geologic observations of an oxygenated ocean since the mid-Cretaceous. Barring decreases of ocean phosphate on the order of 30%-50%, deep-water formation at high latitudes was a major source of ocean ventilation in the warmer past. C1 PRINCETON UNIV,PROGRAM ATMOSPHER & OCEAN SCI,PRINCETON,NJ 08544. RP HERBERT, TD (reprint author), UNIV CALIF SAN DIEGO,SCRIPPS INST OCEANOG,DIV GEOL RES,LA JOLLA,CA 92093, USA. NR 33 TC 28 Z9 28 U1 1 U2 1 PU GEOLOGICAL SOC AMERICA PI BOULDER PA PO BOX 9140 3300 PENROSE PLACE, BOULDER, CO 80301 SN 0091-7613 J9 GEOLOGY JI Geology PD JUL PY 1991 VL 19 IS 7 BP 702 EP 705 DI 10.1130/0091-7613(1991)019<0702:ONDAOL>2.3.CO;2 PG 4 WC Geology SC Geology GA FV902 UT WOS:A1991FV90200008 ER PT J AU CUMMINS, P WAHR, JM AGNEW, DC TAMURA, Y AF CUMMINS, P WAHR, JM AGNEW, DC TAMURA, Y TI CONSTRAINING CORE UNDERTONES USING STACKED IDA GRAVITY RECORDS SO GEOPHYSICAL JOURNAL INTERNATIONAL LA English DT Article DE EARTH TIDES; GRAVITY; UNDERTONES ID EARTHS FLUID CORE; SUPERCONDUCTING GRAVIMETER; SOUTH POLE; OSCILLATIONS; SPECTRUM; BRUSSELS; RETRIEVAL; SURFACE; WAVES; TIDES AB A search is made for oscillatory gravity signals, possibly associated with core undertones, in the frequency range between the diurnal and semidiurnal tidal bands. IDA tidal data recorded during 6 month intervals following four large earthquakes were used, and the data from different stations were stacked according to spherical harmonic surface amplitude patterns with angular order l less-than-or-equal-to 4. The detection level of a signal in the diurnal-semidiurnal frequency band was roughly 10-20 ngal, but the only signal detected was a 9 ngal signal of 9.54 hr period whose origin remains unexplained. Two of the earthquakes were chosen because of claims that core undertones were excited following these events, and it is established that signals of the required amplitude, if they exist, can only be associated with a few spherical harmonic patterns for which the Brussels instrument is near an antinode. We also used NCAR barometric data to correct the gravity recordings for the effects of atmospheric pressure variations, which reduces the noise level in the diurnal-semidiurnal frequency band by 2-3 dB. C1 UNIV COLORADO, NOAA, COOPERAT INST RES ENVIRONM SCI, BOULDER, CO 80309 USA. UNIV COLORADO, DEPT PHYS, BOULDER, CO 80309 USA. UNIV CALIF SAN DIEGO, SCRIPPS INST OCEANOG, INST GEOPHYS & PLANETARY PHYS, LA JOLLA, CA 92093 USA. RP AUSTRALIAN NATL UNIV, RES SCH EARTH SCI, GPO BOX 4, CANBERRA, ACT 2601, AUSTRALIA. NR 36 TC 33 Z9 38 U1 0 U2 2 PU OXFORD UNIV PRESS PI OXFORD PA GREAT CLARENDON ST, OXFORD OX2 6DP, ENGLAND SN 0956-540X EI 1365-246X J9 GEOPHYS J INT JI Geophys. J. Int. PD JUL PY 1991 VL 106 IS 1 BP 189 EP 198 PG 10 WC Geochemistry & Geophysics SC Geochemistry & Geophysics GA FV404 UT WOS:A1991FV40400015 ER PT J AU MLYNCZAK, MG SOLOMON, S AF MLYNCZAK, MG SOLOMON, S TI ON THE EFFICIENCY OF SOLAR HEATING IN THE MIDDLE ATMOSPHERE SO GEOPHYSICAL RESEARCH LETTERS LA English DT Article ID MESOSPHERE EXPLORER; LOWER THERMOSPHERE; OZONE; ABSORPTION; O2 AB We calculate the efficiency at which solar ultraviolet radiation absorbed in the Hartley band of ozone is directly converted to heat in the terrestrial mesosphere and lower thermosphere (50-110 km). The ozone molecule undergoes photolysis to yield the excited species O(1D) and O2(1-DELTA) with a quantum yield of about 0.9. Spontaneous emission from O2(1-DELTA) and from O2(1-SIGMA) (excited by energy transfer from O(1D)) significantly decreases the amount of energy available for heat. Similarly, we calculate the efficiency at which solar ultraviolet radiation absorbed by O2 in the Schumann-Runge continuum is directly converted to heat in the lower thermosphere (95-110 km). The O2 undergoes photolysis and the excited product O(1D) is generated. Spontaneous emission from O2(1-SIGMA) (excited by energy transfer from O(1D)) reduces the amount of energy available for heat in the lower thermosphere. The consideration of these energy transfer and loss processes results in significantly reduced heating rates as compared to those conventionally calculated in models of the middle atmosphere. C1 NOAA,AERON LAB,BOULDER,CO 80303. RP MLYNCZAK, MG (reprint author), NASA,LANGLEY RES CTR,MAIL STOP 401B,HAMPTON,VA 23665, USA. RI Mlynczak, Martin/K-3396-2012 NR 16 TC 24 Z9 24 U1 1 U2 5 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 SN 0094-8276 J9 GEOPHYS RES LETT JI Geophys. Res. Lett. PD JUL PY 1991 VL 18 IS 7 BP 1201 EP 1204 DI 10.1029/91GL01525 PG 4 WC Geosciences, Multidisciplinary SC Geology GA FW155 UT WOS:A1991FW15500008 ER PT J AU JACOBOWITZ, H AF JACOBOWITZ, H TI ESTIMATION OF THE EARTHS RADIATION BUDGET FROM NARROW-BAND NOAA SATELLITE-OBSERVATIONS SO GLOBAL AND PLANETARY CHANGE LA English DT Article; Proceedings Paper CT CONF ON OPERATIONAL SATELLITES : SENTINELS FOR THE MONITORING OF CLIMATE AND GLOBAL CHANGE CY OCT 16-19, 1990 CL WASHINGTON, DC SP NATL OCEAN & ATMOSPHER ADMIN, US DEPT COMMERCE AB Operational satellites provide global data from multispectral narrowband radiometric scanners such as the Advanced Very High Resolution Radiometer (AVHRR) and the High Resolution Infrared Radiation Sounder (HIRS) found on the polar-orbiting NOAA series of satellites. For many years, the narrowband channels have been utilized to estimate the components of the Earth's radiation budget (ERB). Broadband instruments specially designed for ERB measurements have been available only on experimental satellites. Unfortunately, these instruments have been very intermittent in their coverage, with large gap's in time occurring between the failure of an instrument and the launch of its successor. AVHRR instruments, on the other hand, have been present on every operational NOAA satellite since 1979, making it possible for continuous coverage. The evolution of the ERB products generated from the AVHRR over this period will be discussed, as well as the expectations and plans for the future. This will include a brief tutorial on the generation of the current products, a discussion on anticipated improvements to the algorithms, the use of the HIRS in estimating the outgoing longwave radiation flux, and the development of new products that will enhance our ability to monitor climate and global change. RP JACOBOWITZ, H (reprint author), NOAA,NATL ENVIRONM SATELLITE DATA & INFORMAT SERV,WASHINGTON,DC 20233, USA. NR 9 TC 2 Z9 2 U1 0 U2 0 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0921-8181 J9 GLOBAL PLANET CHANGE JI Glob. Planet. Change PD JUL PY 1991 VL 90 IS 1-3 BP 11 EP 16 PG 6 WC Geography, Physical; Geosciences, Multidisciplinary SC Physical Geography; Geology GA GD079 UT WOS:A1991GD07900003 ER PT J AU STOWE, LL AF STOWE, LL TI CLOUD AND AEROSOL PRODUCTS AT NOAA NESDIS SO GLOBAL AND PLANETARY CHANGE LA English DT Article; Proceedings Paper CT CONF ON OPERATIONAL SATELLITES : SENTINELS FOR THE MONITORING OF CLIMATE AND GLOBAL CHANGE CY OCT 16-19, 1990 CL WASHINGTON, DC SP NATL OCEAN & ATMOSPHER ADMIN, US DEPT COMMERCE ID CLIMATE AB Global observations of cloud and aerosol properties from satellites are needed to understand the role of these atmospheric constituents in climate change, e.g. their radiative forcing and feedback effects and trends in their optical and physical characteristics. NOAA/NESDIS has developed remote sensing techniques as a means of providing these global measurements. As a by-product of our atmospheric sounding programs, TOVS and VAS infrared window and CO2 absorption band measurements are used to determine an "effective" cloud amount and cloud top pressure. Cloud liquid water content is being derived from DMSP/SSMT data. AVHRR data are used to derive total cloud amount. AVHRR data are also used to estimate aerosol optical thickness over the oceans. A brief description of the retrieval methods and their verification will be given, as well as several examples of these products. RP STOWE, LL (reprint author), US DEPT COMM,NOAA,NATL ENVIRONM SATELLITE DATA & INFORMAT SERV,SATELLITE RES LAB,WASHINGTON,DC 20233, USA. NR 18 TC 15 Z9 15 U1 0 U2 0 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 JUL PY 1991 VL 90 IS 1-3 BP 25 EP 32 PG 8 WC Geography, Physical; Geosciences, Multidisciplinary SC Physical Geography; Geology GA GD079 UT WOS:A1991GD07900005 ER PT J AU WYLIE, D MENZEL, WP AF WYLIE, D MENZEL, WP TI A CIRRUS CLOUD CLIMATOLOGY FROM NOAA HIRS SO GLOBAL AND PLANETARY CHANGE LA English DT Article; Proceedings Paper CT CONF ON OPERATIONAL SATELLITES : SENTINELS FOR THE MONITORING OF CLIMATE AND GLOBAL CHANGE CY OCT 16-19, 1990 CL WASHINGTON, DC SP NATL OCEAN & ATMOSPHER ADMIN, US DEPT COMMERCE AB A climatology of upper tropospheric semi-transparent cirrus clouds is being compiled front multispectral infrared data collected by the HIRS on the NOAA polar orbiting satellites. This is a report on the first year of data analyzed (June 1989-May 1990). Semi-transparent clouds were found in 43% of the observations. Large seasonal changes were found in these clouds in many geographical areas. Previous studies restricted to the continental United States, indicated that semi-transparent clouds occurred in nearly the same frequency in all seasons. However, the global data from the NOAA/HIRS show that large changes occur in areas dominated by three major weather features; the ITCZ, the sub-tropical high pressure systems, and the mid-latitude storm belts. Semi-transparent clouds associated with these features, move latitudinally with the seasons. These clouds also are more frequent in the summer hemisphere than the winter hemisphere. They appear to be linked to convective cloud development and the mid-latitudinal frontal weather systems. C1 NATL ENVIRONM SATELLITE DATA & INFORMAT SERV,NOAA,SATELLITE APPLICAT LAB,MADISON,WI 53706. RP WYLIE, D (reprint author), UNIV WISCONSIN,CTR SPACE SCI & ENGN,1225 W DAYTON ST,MADISON,WI 53706, USA. RI Menzel, W. Paul/B-8306-2011 OI Menzel, W. Paul/0000-0001-5690-1201 NR 4 TC 3 Z9 3 U1 0 U2 0 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0921-8181 J9 GLOBAL PLANET CHANGE JI Glob. Planet. Change PD JUL PY 1991 VL 90 IS 1-3 BP 49 EP 53 PG 5 WC Geography, Physical; Geosciences, Multidisciplinary SC Physical Geography; Geology GA GD079 UT WOS:A1991GD07900008 ER PT J AU CHESTERS, D NEUENDORFFER, A AF CHESTERS, D NEUENDORFFER, A TI COMPARISON BETWEEN TOMS, TOVS AND DOBSON OBSERVATIONS - SATELLITE AND SURFACE VIEWS OF TOTAL COLUMN OZONE SO GLOBAL AND PLANETARY CHANGE LA English DT Article; Proceedings Paper CT CONF ON OPERATIONAL SATELLITES : SENTINELS FOR THE MONITORING OF CLIMATE AND GLOBAL CHANGE CY OCT 16-19, 1990 CL WASHINGTON, DC SP NATL OCEAN & ATMOSPHER ADMIN, US DEPT COMMERCE AB TOVS infrared and microwave observations are now being used to estimate total column ozone over the globe by employing a new physical retrieval algorithm. The TOVS archives from 1979 to the present have been reprocessed, and the results during the great Antarctic "ozone hole" of 1987 are compared with the corresponding TOMS and DOBSON ultraviolet observations of total ozone. The TOVS total ozone patterns appear to be reliable on the synoptic scale and provide a unique opportunity to track ozone variations during polar night. However, there are times and places where each of the three ozone datasets contains errors that are significantly larger than a few percent. C1 NATL ENVIRONM SATELLITE DATA & INFORMAT SERV,NOAA,PHYS BRANCH,HILLCREST HTS,MD 20274. RP CHESTERS, D (reprint author), NASA,GODDARD SPACE FLIGHT CTR,GODDARD LAB ATMOSPHERES,GREENBELT,MD 20771, USA. NR 14 TC 7 Z9 7 U1 0 U2 0 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 JUL PY 1991 VL 90 IS 1-3 BP 61 EP 67 PG 7 WC Geography, Physical; Geosciences, Multidisciplinary SC Physical Geography; Geology GA GD079 UT WOS:A1991GD07900010 ER PT J AU MILLER, AJ AF MILLER, AJ TI MONITORING THE STRATOSPHERE WITH SATELLITES AND THE NETWORK FOR DETECTION OF STRATOSPHERIC CHANGE SO GLOBAL AND PLANETARY CHANGE LA English DT Article; Proceedings Paper CT CONF ON OPERATIONAL SATELLITES : SENTINELS FOR THE MONITORING OF CLIMATE AND GLOBAL CHANGE CY OCT 16-19, 1990 CL WASHINGTON, DC SP NATL OCEAN & ATMOSPHER ADMIN, US DEPT COMMERCE AB The emphasis in the series of papers in this issue is the use of operational satellite information. Within this paper, however, we will examine a slightly different aspect of the problem. We will discuss how the satellite and ground-based observations, from the viewpoint of monitoring the stratosphere are synergistic in that each provides a key part of the total information necessary. Finally, we will look toward the future of the ground-based data program and present information on the ground-based data program and present information on the Network for Detection of Stratospheric Change. RP MILLER, AJ (reprint author), NOAA,NATL WEATHER SERV,NATL METEOROL CTR,CTR CLIMATE ANAL,WWB,ROOM 811,WASHINGTON,DC 20233, 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 0921-8181 J9 GLOBAL PLANET CHANGE JI Glob. Planet. Change PD JUL PY 1991 VL 90 IS 1-3 BP 69 EP 71 PG 3 WC Geography, Physical; Geosciences, Multidisciplinary SC Physical Geography; Geology GA GD079 UT WOS:A1991GD07900011 ER PT J AU CHANDRA, S MCPETERS, RD HUDSON, RD PLANET, W AF CHANDRA, S MCPETERS, RD HUDSON, RD PLANET, W TI OZONE MEASUREMENTS FROM THE NOAA-9 AND THE NIMBUS-7 SATELLITES - IMPLICATIONS OF SHORT AND LONG-TERM VARIABILITIES SO GLOBAL AND PLANETARY CHANGE LA English DT Meeting Abstract C1 NOAA,NATL ENVIRONM SATELLITE DATA & INFORMAT SERV,WASHINGTON,DC 20233. RP CHANDRA, S (reprint author), NASA,GODDARD SPACE FLIGHT CTR,ATMOSPHERES LAB,GREENBELT,MD 20771, USA. RI Hudson, Robert/F-4506-2010; McPeters, Richard/G-4955-2013 OI McPeters, Richard/0000-0002-8926-8462 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 0921-8181 J9 GLOBAL PLANET CHANGE JI Glob. Planet. Change PD JUL PY 1991 VL 90 IS 1-3 BP 73 EP 73 PG 1 WC Geography, Physical; Geosciences, Multidisciplinary SC Physical Geography; Geology GA GD079 UT WOS:A1991GD07900012 ER PT J AU GELMAN, ME AF GELMAN, ME TI STRATOSPHERIC MONITORING WITH TOVS DATA SO GLOBAL AND PLANETARY CHANGE LA English DT Article; Proceedings Paper CT CONF ON OPERATIONAL SATELLITES : SENTINELS FOR THE MONITORING OF CLIMATE AND GLOBAL CHANGE CY OCT 16-19, 1990 CL WASHINGTON, DC SP NATL OCEAN & ATMOSPHER ADMIN, US DEPT COMMERCE AB Stratospheric monitoring is a key element in the Climate and Global Change Program. Temperature data from the TIROS Operational Vertical Sounders have provided global information from which the entire stratosphere has been monitored on a daily basis since 1978. Operational soundings produced by the National Environmental Satellite, Data, and Information Service have been analyzed at the Climate Analysis Center, National Meteorological Center, NOAA to produce daily fields of temperature and geopotential height at eight stratospheric pressure levels, 70-0.4 mb (18-55 km). These analyses support numerous real-time operational and research applications and also form the basis for assessing stratospheric temperature trends associated with stratospheric ozone changes. This paper provides an overview of several applications of TOVS stratospheric analyses, and offers suggestions for improving the TOVS data in the future. RP GELMAN, ME (reprint author), NOAA,NATL WEATHER SERV,NATL METEOROL CTR,CTR CLIMATE ANAL,WASHINGTON,DC 20233, USA. NR 4 TC 6 Z9 6 U1 0 U2 0 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 JUL PY 1991 VL 90 IS 1-3 BP 75 EP 78 PG 4 WC Geography, Physical; Geosciences, Multidisciplinary SC Physical Geography; Geology GA GD079 UT WOS:A1991GD07900013 ER PT J AU SCOFIELD, RA AF SCOFIELD, RA TI OPERATIONAL ESTIMATION OF PRECIPITATION FROM SATELLITE DATA SO GLOBAL AND PLANETARY CHANGE LA English DT Article; Proceedings Paper CT CONF ON OPERATIONAL SATELLITES : SENTINELS FOR THE MONITORING OF CLIMATE AND GLOBAL CHANGE CY OCT 16-19, 1990 CL WASHINGTON, DC SP NATL OCEAN & ATMOSPHER ADMIN, US DEPT COMMERCE AB Since 1978, the National Environmental Satellite, Data, and Information Service (NESDIS) of the National Oceanic and Atmospheric Administration (NOAA) has been operationally producing satellite estimates and outlooks of heavy precipitation to the National Weather Service (NWS) Forecast Offices and River Forecast Centers (RFC). These estimates and outlooks aid the NWS in issuing flash flood watches and warnings. Additionally, NESDIS is providing the following products for monitoring and assessing global precipitation: (1) Infrared (IR) Histograms of the GOES Precipitation Index between 40-degrees-N and 40-degrees-S; (2) Global Cloud Liguid Water from the Special Sensor Microwave/Temperature (SSM/T)-over water only; (3) Global Precipitation from the Special Sensor Microwave/Imager (SSM/I)-over land and water. These products are being collected and verified by NOAA's Climate Analysis Center (CAC). Over the next 3-5 years, product improvements are planned through: (1) integration of the microwave, visible, and IR measurements to produce a tri-spectral precipitation product; and (2) modification of the tri-spectral global precipitation product for seasonal variations, regional differences, and collateral data. RP SCOFIELD, RA (reprint author), NOAA,NATL ENVIRONM SATELLITE DATA & INFORMAT SERV,SATELLITE APPLICAT LAB,WASHINGTON,DC 20233, USA. NR 14 TC 3 Z9 3 U1 0 U2 0 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0921-8181 J9 GLOBAL PLANET CHANGE JI Glob. Planet. Change PD JUL PY 1991 VL 90 IS 1-3 BP 79 EP 86 PG 8 WC Geography, Physical; Geosciences, Multidisciplinary SC Physical Geography; Geology GA GD079 UT WOS:A1991GD07900014 ER PT J AU JANOWIAK, JF AF JANOWIAK, JF TI THE RELIANCE ON OPERATIONAL WEATHER-SATELLITES FOR THE PRODUCTION OF A GLOBAL PRECIPITATION CLIMATOLOGY SO GLOBAL AND PLANETARY CHANGE LA English DT Article; Proceedings Paper CT CONF ON OPERATIONAL SATELLITES : SENTINELS FOR THE MONITORING OF CLIMATE AND GLOBAL CHANGE CY OCT 16-19, 1990 CL WASHINGTON, DC SP NATL OCEAN & ATMOSPHER ADMIN, US DEPT COMMERCE ID RAINFALL; CLOUD AB A program to develop a global precipitation climatology for the period 1986-95 is discussed, with emphasis on the tropics. This program, the Global Precipitation Climatology Project (GPCP), will produce areal averaged precipitation for 5-day (pentad) and monthly time periods for each 2.5-degrees latitude/longitude region on the earth. Due to the paucity of conventional precipitation observations (rainguage, radar) in many parts of the world, precipitation estimates as inferred from infrared and microwave satellite data must be used extensively. The calibration of the precipitation estimation algorithms and the validation of the estimates are integral parts of the GPCP. RP JANOWIAK, JF (reprint author), NOAA,NATL WEATHER SERV,NATL METEOROL CTR,CTR CLIMATE ANAL,WASHINGTON,DC 20233, USA. NR 9 TC 1 Z9 1 U1 0 U2 0 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 JUL PY 1991 VL 90 IS 1-3 BP 93 EP 98 PG 6 WC Geography, Physical; Geosciences, Multidisciplinary SC Physical Geography; Geology GA GD079 UT WOS:A1991GD07900016 ER PT J AU BURDSALL, EL AF BURDSALL, EL TI NESDIS OPERATIONAL SOUNDING PRODUCTS FROM POLAR ORBITING SATELLITES SO GLOBAL AND PLANETARY CHANGE LA English DT Article; Proceedings Paper CT CONF ON OPERATIONAL SATELLITES : SENTINELS FOR THE MONITORING OF CLIMATE AND GLOBAL CHANGE CY OCT 16-19, 1990 CL WASHINGTON, DC SP NATL OCEAN & ATMOSPHER ADMIN, US DEPT COMMERCE AB NOAA has been producing vertical temperature and moisture profiles from the TIROS Operational Vertical Sounder (TOVS) since 1979. In 1985, NOAA also began producing vertical temperature profiles from the Defense Meteorological Satellite Program's (DMSP) SSM/T (Special Sensor Microwave/Temperature) instrument. The National Environmental Satellite, Data, and Information Service (NESDIS) is NOAA's center of expertise for processing these satellite data. NESDIS carefully monitors and performs quality checks on these data throughout the processing stream. Raw radiance data and the derived products are archived for use by non-real-time users. The raw radiance data are archived completely with suspected data flagged. The derived product archive contains only good data. In the past, vertical temperature data were used primarily in numerical weather prediction (NWP) models. Now, as more research scientists turn to climate modeling, NESDIS is enhancing the archive products to satisfy this new demand. Current modifications include enlarging the file and adding more quality control information. RP BURDSALL, EL (reprint author), NOAA,NATL ENVIRONM SATELLITE DATA & INFORMAT SERV,WASHINGTON,DC 20233, 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 0921-8181 J9 GLOBAL PLANET CHANGE JI Glob. Planet. Change PD JUL PY 1991 VL 90 IS 1-3 BP 107 EP 111 PG 5 WC Geography, Physical; Geosciences, Multidisciplinary SC Physical Geography; Geology GA GD079 UT WOS:A1991GD07900018 ER PT J AU SPENCER, RW CHRISTY, JR GRODY, NC AF SPENCER, RW CHRISTY, JR GRODY, NC TI PRECISION TROPOSPHERIC TEMPERATURE MONITORING 1979-1990 SO GLOBAL AND PLANETARY CHANGE LA English DT Article; Proceedings Paper CT CONF ON OPERATIONAL SATELLITES : SENTINELS FOR THE MONITORING OF CLIMATE AND GLOBAL CHANGE CY OCT 16-19, 1990 CL WASHINGTON, DC SP NATL OCEAN & ATMOSPHER ADMIN, US DEPT COMMERCE AB The TIROS-N microwave sounding units (MSU's) have demonstrated an ability to measure globally averaged tropospheric brightness temperature anomalies to a precision of 0.01-degrees-C per month. This has been revealed by five separate overlap periods of concurrently operating morning and afternoon satellites. For MSU channel 2, comparisons to ten years of radiosonde data show that these anomalies are closely related to anomalies in 850-300 mbar thickness, with gridpoint correlations to radiosondes usually ranging between 0.85 and 0.95. The comparisons also suggest that there is no drift or bias in the MSU's (or US-controlled radiosonde system) between 1979-1988 to about 0.01-degrees-C when results are averaged over the Pacific or Caribbean. The non-trivial amount of lower stratospheric influence on MSU channel 2, combined with evidence for cooling in that layer during 1979-1990, suggests the need for removal of this effect from the measurements before interpretation in terms of a "tropospheric" temperature. Because the NOAA-6 MSU channel 3 was not usable for precision climate monitoring due to a sizeable drift, we have performed a retrieval on MSU channel 2 at different view angles to achieve stratospheric cancellation. We present global brightness temperature anomalies of both raw channel 2 and the tropospheric retrieval for the period 1979-1990. It appears that the MSU's (and presumably the advanced microwave sounding units as well) will provide a valuable resource for not only monitoring intraseasonal to interannual climate change, but also for long-term monitoring of potential global warming. C1 NOAA,NATL ENVIRONM SATELLITE DATA & INFORMAT SERV,WASHINGTON,DC 20233. UNIV ALABAMA,JOHNSON RES CTR,HUNTSVILLE,AL 35899. RP SPENCER, RW (reprint author), NASA,GEORGE C MARSHALL SPACE FLIGHT CTR,ES43,HUNTSVILLE,AL 35812, USA. NR 2 TC 2 Z9 2 U1 0 U2 0 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 JUL PY 1991 VL 90 IS 1-3 BP 113 EP 120 PG 8 WC Geography, Physical; Geosciences, Multidisciplinary SC Physical Geography; Geology GA GD079 UT WOS:A1991GD07900019 ER PT J AU MOORE, DA DRAHOS, HF AF MOORE, DA DRAHOS, HF TI COMPARISON OF MICROWAVE TEMPERATURE SOUNDERS FOR ATMOSPHERIC MONITORING SO GLOBAL AND PLANETARY CHANGE LA English DT Article; Proceedings Paper CT CONF ON OPERATIONAL SATELLITES : SENTINELS FOR THE MONITORING OF CLIMATE AND GLOBAL CHANGE CY OCT 16-19, 1990 CL WASHINGTON, DC SP NATL OCEAN & ATMOSPHER ADMIN, US DEPT COMMERCE AB Passive microwave observations from the Microwave Sounding Unit (MSU) on board the National Oceanic and Atmospheric Administration (NOAA) series of spacecraft have been shown to be useful for long-term global atmospheric temperature monitoring. The Special Sensor Microwave/Temperature (SSM/T) sounder, on board the Defense Meterological Satellite Program (DMSP) spacecraft, is equipped with twice as many atmospheric channels as the MSU. First flown in 1979, archived SSM/T data are available since 1987. As an initial effort to assess the utility of this data source for climate monitoring, antenna temperatures from the two operational SSM/T instruments were compared by channel, beam position, and latitude. Results indicate antenna temperatures from one SSM/T (F8) are systematically 1-3 K higher than from the other (F9). Also, asymmetries exist with respect to beam positions. C1 NOAA,NATL ENVIRONM SATELLITE DATA & INFORMAT SERV,WASHINGTON,DC 20233. RP MOORE, DA (reprint author), SM SYST & RES CORP,LANDOVER,MD 20785, 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 0921-8181 J9 GLOBAL PLANET CHANGE JI Glob. Planet. Change PD JUL PY 1991 VL 90 IS 1-3 BP 127 EP 133 PG 7 WC Geography, Physical; Geosciences, Multidisciplinary SC Physical Geography; Geology GA GD079 UT WOS:A1991GD07900021 ER PT J AU REALE, A CHALFANT, M AF REALE, A CHALFANT, M TI A CLIMATIC DATABASE OF ATMOSPHERIC THERMAL MEASUREMENTS FROM OPERATIONAL ENVIRONMENTAL SATELLITES (ATMOES) SO GLOBAL AND PLANETARY CHANGE LA English DT Article; Proceedings Paper CT CONF ON OPERATIONAL SATELLITES : SENTINELS FOR THE MONITORING OF CLIMATE AND GLOBAL CHANGE CY OCT 16-19, 1990 CL WASHINGTON, DC SP NATL OCEAN & ATMOSPHER ADMIN, US DEPT COMMERCE AB Since the onset of TIROS operational Vertical Sounder (TOVS) processing in 1979, a primary objective has been to produce and distribute atmospheric sounding data to support numerical weather prediction forecast models. However, the concern during the 1980's for man-induced atmospheric changes has resulted in a growing public concern. A new goal to provide monitoring of the earth-atmosphere system on a climatic scale has evolved. This has resulted in a new requirement to provide operational atmospheric products conductive to monitoring the earth's climate. This new requirement cannot be satified immediately. A three-part plan is presented to compile and maintain an operational climatic database of Atmospheric Thermal Measurements from operational Environmental Satellites (ATMOES). The plan includes: (1) the development and implementation of operational procedures for the generation of climatic databases during NESDIS operational processing; (2) data collection and the retrospective TOVS processing of climatic databases going back to 1979; and (3) the development of analysis and graphic display capabilities. RP REALE, A (reprint author), NOAA,NATL ENVIRONM SATELLITE DATA & INFORMAT SERV,ORA,WASHINGTON,DC 20233, USA. RI Reale, Tony/F-5621-2010; Chalfant, Mike/F-5579-2010 OI Reale, Tony/0000-0003-2150-5246; Chalfant, Mike/0000-0003-0636-9813 NR 10 TC 0 Z9 0 U1 0 U2 0 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 JUL PY 1991 VL 90 IS 1-3 BP 135 EP 140 PG 6 WC Geography, Physical; Geosciences, Multidisciplinary SC Physical Geography; Geology GA GD079 UT WOS:A1991GD07900022 ER PT J AU RUTLEDGE, G LEGG, E MENZEL, P AF RUTLEDGE, G LEGG, E MENZEL, P TI OPERATIONAL PRODUCTION OF WINDS FROM CLOUD MOTIONS SO GLOBAL AND PLANETARY CHANGE LA English DT Article; Proceedings Paper CT CONF ON OPERATIONAL SATELLITES : SENTINELS FOR THE MONITORING OF CLIMATE AND GLOBAL CHANGE CY OCT 16-19, 1990 CL WASHINGTON, DC SP NATL OCEAN & ATMOSPHER ADMIN, US DEPT COMMERCE AB Operational production of NOAA cloud motion winds is reviewed. A new technique to improve the height assignment of the cloud motion winds is described and statistical verification of satellite wind information is discussed. Higher quality satellite wind data are a valuable tool to improved descriptions of global atmospheric circulation, which is an important constituent in studies of climate and global change. C1 NOAA,NATL ENVIRONM SATELLITE DATA & INFORMAT SERV,SATELLITE APPLIC LAB,MADISON,WI. NOAA,NATL ENVIRONM SATELLITE DATA & INFORMAT SERV,DIV SATELLITE SERV,WASHINGTON,DC 20233. RP RUTLEDGE, G (reprint author), NOAA,NATL ENVIRONM SATELLITE DATA & INFORMAT SERV,INTERACT PROC BRANCH,WASHINGTON,DC 20233, USA. RI Menzel, W. Paul/B-8306-2011 OI Menzel, W. Paul/0000-0001-5690-1201 NR 6 TC 3 Z9 3 U1 0 U2 0 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 JUL PY 1991 VL 90 IS 1-3 BP 141 EP 150 PG 10 WC Geography, Physical; Geosciences, Multidisciplinary SC Physical Geography; Geology GA GD079 UT WOS:A1991GD07900023 ER PT J AU BAKER, WE AF BAKER, WE TI UTILIZATION OF SATELLITE WINDS FOR CLIMATE AND GLOBAL CHANGE STUDIES SO GLOBAL AND PLANETARY CHANGE LA English DT Article; Proceedings Paper CT CONF ON OPERATIONAL SATELLITES : SENTINELS FOR THE MONITORING OF CLIMATE AND GLOBAL CHANGE CY OCT 16-19, 1990 CL WASHINGTON, DC SP NATL OCEAN & ATMOSPHER ADMIN, US DEPT COMMERCE ID ATMOSPHERE AB The importance of wind measurements for climate and global change research is reviewed, particularly with respect to the data anticipated from the Laser Atmospheric Wind Sounder (LAWS). RP BAKER, WE (reprint author), NOAA,NATL WEATHER SERV,NATL METEOROL CTR,WASHINGTON,DC 20233, USA. NR 11 TC 3 Z9 3 U1 0 U2 0 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 JUL PY 1991 VL 90 IS 1-3 BP 157 EP 163 PG 7 WC Geography, Physical; Geosciences, Multidisciplinary SC Physical Geography; Geology GA GD079 UT WOS:A1991GD07900025 ER PT J AU PICHEL, WG AF PICHEL, WG TI OPERATIONAL PRODUCTION OF MULTICHANNEL SEA-SURFACE TEMPERATURES FROM NOAA POLAR SATELLITE AVHRR DATA SO GLOBAL AND PLANETARY CHANGE LA English DT Article; Proceedings Paper CT CONF ON OPERATIONAL SATELLITES : SENTINELS FOR THE MONITORING OF CLIMATE AND GLOBAL CHANGE CY OCT 16-19, 1990 CL WASHINGTON, DC SP NATL OCEAN & ATMOSPHER ADMIN, US DEPT COMMERCE AB Data from the Advanced Very High Resolution Radiometer (AVHRR) flown on the NOAA series of polar-orbiting environmental satellites have been used to produce operational sea surface temperature (SST) products since January 1979. With the implementation of linear Multichannel SST (MCSST) equations and multichannel cloud screening tests in November 1981, accuracy and resolution improved significantly. Recently (March 1990), accuracy has been improved again with the implementation of nonlinear SST equations. When compared with drifting buoy SST observations, daytime and nighttime satellite SST observations produced from these new equations have global biases less than 0.3-degrees-C and standard deviations less than 0.7-degrees-C. From a daily global set of approximately 120,000 SST observations at 8 km resolution, series of operational products are produced routinely, some of which are of interest to the climate community. RP PICHEL, WG (reprint author), US DEPT COMMERCE,NOAA,NATL ENVIRONM SATELLITE DATA & INFORMAT SERV,WASHINGTON,DC 20233, USA. RI Pichel, William/F-5619-2010 OI Pichel, William/0000-0001-6332-0149 NR 9 TC 8 Z9 10 U1 0 U2 0 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 JUL PY 1991 VL 90 IS 1-3 BP 173 EP 177 PG 5 WC Geography, Physical; Geosciences, Multidisciplinary SC Physical Geography; Geology GA GD079 UT WOS:A1991GD07900027 ER PT J AU REYNOLDS, RW AF REYNOLDS, RW TI SEA-SURFACE TEMPERATURES ANALYSES FROM INSITU AND SATELLITE DATA SO GLOBAL AND PLANETARY CHANGE LA English DT Article; Proceedings Paper CT CONF ON OPERATIONAL SATELLITES : SENTINELS FOR THE MONITORING OF CLIMATE AND GLOBAL CHANGE CY OCT 16-19, 1990 CL WASHINGTON, DC SP NATL OCEAN & ATMOSPHER ADMIN, US DEPT COMMERCE AB Two sea surface temperature analyses are presented which use both in situ and satellite data. The data sources and the analysis techniques are discussed and compared. RP REYNOLDS, RW (reprint author), NOAA,NATL WEATHER SERV,NATL METEOROL CTR,CTR CLIMATE ANAL,WASHINGTON,DC 20233, 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 0921-8181 J9 GLOBAL PLANET CHANGE JI Glob. Planet. Change PD JUL PY 1991 VL 90 IS 1-3 BP 183 EP 187 PG 5 WC Geography, Physical; Geosciences, Multidisciplinary SC Physical Geography; Geology GA GD079 UT WOS:A1991GD07900029 ER PT J AU TARPLEY, JD AF TARPLEY, JD TI THE NOAA GLOBAL VEGETATION INDEX PRODUCT - A REVIEW SO GLOBAL AND PLANETARY CHANGE LA English DT Article; Proceedings Paper CT CONF ON OPERATIONAL SATELLITES : SENTINELS FOR THE MONITORING OF CLIMATE AND GLOBAL CHANGE CY OCT 16-19, 1990 CL WASHINGTON, DC SP NATL OCEAN & ATMOSPHER ADMIN, US DEPT COMMERCE ID SATELLITE AB NOAA has produced a Global Vegetation Index (GVI) product on a weekly basis since April, 1982. The GVI product provides a low-resolution real-time global data base of vegetation index Advanced Very High Resolution Radiometer (AVHRR) channel values, and observation geometry. Changes and improvements in the GVI since its beginning are described and a detailed description of current processing is provided. The GVI product will be changed with the launch of NOAA K, and additional satellite data from the Advanced Microwave Sounding Unit that provides information on surface conditions will be added to the mapped data base. A "second generation" GVI product that will provide a more stable, better calibrated product for climate monitoring will be added in the future. RP TARPLEY, JD (reprint author), NOAA,NATL ENVIRONM SATELLITE DATA & INFORMAT SERV,SATELLITE RES LAB,5627 ALLENTOWN RD,CAMP SPRINGS,MD 20746, USA. NR 11 TC 13 Z9 13 U1 0 U2 1 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 JUL PY 1991 VL 90 IS 1-3 BP 189 EP 194 PG 6 WC Geography, Physical; Geosciences, Multidisciplinary SC Physical Geography; Geology GA GD079 UT WOS:A1991GD07900030 ER PT J AU GUTMAN, GG AF GUTMAN, GG TI MONITORING LAND ECOSYSTEMS USING THE NOAA GLOBAL VEGETATION INDEX DATA SET SO GLOBAL AND PLANETARY CHANGE LA English DT Article; Proceedings Paper CT CONF ON OPERATIONAL SATELLITES : SENTINELS FOR THE MONITORING OF CLIMATE AND GLOBAL CHANGE CY OCT 16-19, 1990 CL WASHINGTON, DC SP NATL OCEAN & ATMOSPHER ADMIN, US DEPT COMMERCE ID SURFACES; AVHRR AB The Global Vegetation Index (GVI) data set produced by NOAA from Advanced Very High Resolution Radiometer measurements for 1985-1988 was used to derive the temporal variability of surface characteristics of diverse ecosystems over the globe. The GVI data were screened for residual cloud contamination and haze. The viewing geometry was restricted to within 25-degrees of nadir. The results are demonstrated using monthly means of the satellite derived parameters spatially averaged over 250 km x 250 km. Phenology of land ecosystems as manifested by the surface albedo, greenness and temperature is analyzed. A color-composite technique for mapping global ecosystems is introduced. RP GUTMAN, GG (reprint author), NOAA,NATL ENVIRONM SATELLITE DATA & INFORMAT SERV,SATELLITE RES LAB,WASHINGTON,DC 20233, USA. NR 17 TC 7 Z9 7 U1 0 U2 3 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 JUL PY 1991 VL 90 IS 1-3 BP 195 EP 200 PG 6 WC Geography, Physical; Geosciences, Multidisciplinary SC Physical Geography; Geology GA GD079 UT WOS:A1991GD07900031 ER PT J AU HALPERT, MS AF HALPERT, MS TI CLIMATE MONITORING USING AN AVHRR-BASED VEGETATION INDEX SO GLOBAL AND PLANETARY CHANGE LA English DT Article; Proceedings Paper CT CONF ON OPERATIONAL SATELLITES : SENTINELS FOR THE MONITORING OF CLIMATE AND GLOBAL CHANGE CY OCT 16-19, 1990 CL WASHINGTON, DC SP NATL OCEAN & ATMOSPHER ADMIN, US DEPT COMMERCE AB A normalized difference vegetation index (NDVI) has been produced and archived on a 1-degree latitude by 1-degree longitude grid between 55-degrees-S and 75-degrees-N. There are many sources of data errors in the NDVI including cloud contamination, scan angle biases, changes in solar zenith angle, and sensor degradation. Week-to-week variability is primarily caused by cloud contamination and scan angle biases and can be minimized by temporally filtering the data. Orbital drift and sensor degradation introduces interannual variability into the dataset. These trends make the usefulness of a long-term climatology uncertain and limit the usefulness of the NDVI. Elimination of these problems should produce an index that can be used for climate monitoring. RP HALPERT, MS (reprint author), NOAA,NATL WEATHER SERV,NATL METEOROL CTR,CLIMATE ANAL CTR,WASHINGTON,DC 20233, USA. NR 0 TC 4 Z9 4 U1 0 U2 0 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 JUL PY 1991 VL 90 IS 1-3 BP 201 EP 205 PG 5 WC Geography, Physical; Geosciences, Multidisciplinary SC Physical Geography; Geology GA GD079 UT WOS:A1991GD07900032 ER PT J AU KNISKERN, FE AF KNISKERN, FE TI THE NAVY NOAA JOINT ICE CENTERS ROLE IN THE CLIMATE AND GLOBAL CHANGE PROGRAM SO GLOBAL AND PLANETARY CHANGE LA English DT Article; Proceedings Paper CT CONF ON OPERATIONAL SATELLITES : SENTINELS FOR THE MONITORING OF CLIMATE AND GLOBAL CHANGE CY OCT 16-19, 1990 CL WASHINGTON, DC SP NATL OCEAN & ATMOSPHER ADMIN, US DEPT COMMERCE AB The Navy/NOAA Joint Ice Center (JIC) is responsible for producing global, regional, and local ice analyses and forecasts for the Arctic, Antarctic, and Great Lakes. Presently, satellite image products are the primary source of sea ice data at the JIC and the NOAA polar orbiting series satellites are the primary source of satellite data. In the future when the JIC's Digital Ice Forecasting and Analysis system (DIFAS) becomes operational, digital satellite data from the NOAA polar orbiters will be used. The JIC is the only organization in the free world that produces weekly global sea ice analyses. These analyses will likely become a good source of data for the cryospheric section of the Climate and Global Change program. Many scientists expect that a change in sea ice extent in the polar regions will be one of the first signals for a change in the earth's climate. A very important new source of data for ice operations and the Climate and Global Change program will be the Synthetic Aperture Radar (SAR) data which will be available in limited amounts starting in 1991. This high-resolution, all-weather data source will allow the JIC, in some polar regions, to provide more detailed analyses of ice extent, ice concentration, ice age and certain ice features such as leads and polynyas. Detailed lead and polynya analyses will yield a better estimate of the heat budget in the polar regions which is an important parameter for the Climate and Global Change program. This paper will describe the various products produced at the JIC and how these products and future ice data and products analyzed on DIFAS will contribute to the cryospheric section of the Climate and Global Change program. RP KNISKERN, FE (reprint author), NOAA,JOINT ICE CTR,WASHINGTON,DC 20233, 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 0921-8181 J9 GLOBAL PLANET CHANGE JI Glob. Planet. Change PD JUL PY 1991 VL 90 IS 1-3 BP 207 EP 212 PG 6 WC Geography, Physical; Geosciences, Multidisciplinary SC Physical Geography; Geology GA GD079 UT WOS:A1991GD07900033 ER PT J AU MATSON, M AF MATSON, M TI NOAA SATELLITE SNOW COVER DATA SO GLOBAL AND PLANETARY CHANGE LA English DT Article; Proceedings Paper CT CONF ON OPERATIONAL SATELLITES : SENTINELS FOR THE MONITORING OF CLIMATE AND GLOBAL CHANGE CY OCT 16-19, 1990 CL WASHINGTON, DC SP NATL OCEAN & ATMOSPHER ADMIN, US DEPT COMMERCE AB Since 1966, NOAA satellites have been used to create weekly Northern Hemisphere snow cover maps. This 24-year database is available on digital tape and is annually updated. The digital data can be used to calculate snow cover area and create snow cover frequency and anomaly maps. It is the only known long-term record of hemisphere snow cover. In 1993, the new NOAA-K,L,M series of satellite will have a radiometer with a channel at 1.6-mu-m which will provide a more accurate assessment of global snow cover as it can discriminate snow from clouds. In addition, the NOAA-K,L,M satellites will have microwave sensors capable of detecting snow cover through clouds. During this decade, climatologists will have a global monitoring system for snow cover based on operational NOAA satellite sensors. RP MATSON, M (reprint author), NOAA,NATL ENVIRONM SATELLITE DATA & INFORMAT SERV,WASHINGTON,DC 20233, USA. NR 2 TC 7 Z9 7 U1 0 U2 1 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 JUL PY 1991 VL 90 IS 1-3 BP 213 EP 218 PG 6 WC Geography, Physical; Geosciences, Multidisciplinary SC Physical Geography; Geology GA GD079 UT WOS:A1991GD07900034 ER PT J AU ROPELEWSKI, CF AF ROPELEWSKI, CF TI REAL-TIME CLIMATE MONITORING OF GLOBAL SNOW COVER SO GLOBAL AND PLANETARY CHANGE LA English DT Article; Proceedings Paper CT CONF ON OPERATIONAL SATELLITES : SENTINELS FOR THE MONITORING OF CLIMATE AND GLOBAL CHANGE CY OCT 16-19, 1990 CL WASHINGTON, DC SP NATL OCEAN & ATMOSPHER ADMIN, US DEPT COMMERCE AB Northern Hemisphere snow cover area has been operationally mapped by NOAA/NESDIS since November 1966. Digitized snow cover charts have been available since 1982. Thus snow cover area is, by far, the oldest and most stable satellite-derived parameter useful for climate monitoring. The use of snow cover is discussed both as a climate monitoring tool, in its own right, and as an example of the problems, challenges, and advantages of satellite data for global climate monitoring. RP ROPELEWSKI, CF (reprint author), NOAA,NATL WEATHER SERV,NATL METEOROL CTR,CTR CLIMATE ANAL,WASHINGTON,DC 20233, USA. NR 6 TC 1 Z9 1 U1 0 U2 1 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 JUL PY 1991 VL 90 IS 1-3 BP 225 EP 229 PG 5 WC Geography, Physical; Geosciences, Multidisciplinary SC Physical Geography; Geology GA GD079 UT WOS:A1991GD07900036 ER PT J AU WEINREB, MP AF WEINREB, MP TI OPERATIONAL CALIBRATION PROCESSING IN NESDIS SO GLOBAL AND PLANETARY CHANGE LA English DT Article; Proceedings Paper CT CONF ON OPERATIONAL SATELLITES : SENTINELS FOR THE MONITORING OF CLIMATE AND GLOBAL CHANGE CY OCT 16-19, 1990 CL WASHINGTON, DC SP NATL OCEAN & ATMOSPHER ADMIN, US DEPT COMMERCE AB This paper describes the in-orbit radiometric calibration of instruments that sense conditions of the Earth's atmosphere and surface from NOAA's polar and geostationary satellites. Infrared and microwave channels are calibrated from data taken when the instruments view space and an on-board warm calibration target. The data from those two views are used in ground processing to determine a linear calibration equation. Modifications are made to this basic calibration algorithm to account for certain complicating factors, such as a non-linear calibration relationship or the presence of rapid variations in the emission from internal components of the instruments. Visible and near-infrared channels are not calibrated in orbit, in part because these channels were originally designed to produce images, not quantitative data. RP WEINREB, MP (reprint author), NOAA,NATL ENVIRONM SATELLITE DATA & INFORMAT SERV,WASHINGTON,DC 20233, 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 0921-8181 J9 GLOBAL PLANET CHANGE JI Glob. Planet. Change PD JUL PY 1991 VL 90 IS 1-3 BP 241 EP 245 PG 5 WC Geography, Physical; Geosciences, Multidisciplinary SC Physical Geography; Geology GA GD079 UT WOS:A1991GD07900039 ER PT J AU WESTWATER, ER FEDOR, LS AF WESTWATER, ER FEDOR, LS TI THE VALIDATION OF MICROWAVE SPACEBORNE OBSERVATIONS BY SURFACE-BASED REMOTE SENSORS SO GLOBAL AND PLANETARY CHANGE LA English DT Article; Proceedings Paper CT CONF ON OPERATIONAL SATELLITES : SENTINELS FOR THE MONITORING OF CLIMATE AND GLOBAL CHANGE CY OCT 16-19, 1990 CL WASHINGTON, DC SP NATL OCEAN & ATMOSPHER ADMIN, US DEPT COMMERCE ID TEMPERATURE AB Passive microwave observations from polar-orbiting satellites provide meterologically important information on temperature profiles, water vapor, and cloud liquid water. The variable measured by radiometers is radiance, or brightness temperature, as a function of frequency, viewing angle, and polarization. Meteorological parameters are then extracted from the radiance measurements by retrieval algorithms. The utility of these parameters, both in operational meteorology and in monitoring climate change, depends on the calibration and stability of the instrument, and on the type of retrieval algorithm that is used. Ultimately, the derived parameters must be compared with ground truth. For temperature and water vapor soundings, radiosondes are frequently used for validation and calibration. However, for the climatologically important variable cloud liquid water, conventional measurements are not adequate, and surface- and aircraft-based remote sensor measurements are required. In this paper, calibration of microwave instruments is discussed and comparisons with various sources of ground truth are presented. In addition, a possible role for surface-based remote sounders in the calibration and validation of satellite products is suggested. These remote sounders include microwave radiometers, wind profilers, and Radio Acoustic Sounding Systems (RASS). RP WESTWATER, ER (reprint author), NOAA,ERL,WAVE PROPAGAT LAB,325 BROADWAY,BOULDER,CO 80303, USA. NR 19 TC 0 Z9 0 U1 0 U2 0 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 JUL PY 1991 VL 90 IS 1-3 BP 247 EP 252 PG 6 WC Geography, Physical; Geosciences, Multidisciplinary SC Physical Geography; Geology GA GD079 UT WOS:A1991GD07900040 ER PT J AU ABEL, P AF ABEL, P TI PRE-LAUNCH CALIBRATION OF AVHRR REFLECTED-SOLAR CHANNELS SO GLOBAL AND PLANETARY CHANGE LA English DT Article; Proceedings Paper CT CONF ON OPERATIONAL SATELLITES : SENTINELS FOR THE MONITORING OF CLIMATE AND GLOBAL CHANGE CY OCT 16-19, 1990 CL WASHINGTON, DC SP NATL OCEAN & ATMOSPHER ADMIN, US DEPT COMMERCE ID NOAA-11 AB Demand for quantitative (rather than qualitative) measurements of reflected-solar radiance has grown during the period of availability of AVHRR data, but even today the most important applications involve image products. The principal purpose of pre-launch radiance calibration of Channels 1 and 2 (centered at approximately 630 and 850 nm) has therefore been to ensure that the channel gains are correctly set to make best use of the dynamic range of the instrument rather than to calibrate the radiance response characteristics of the instrument with high accuracy. This emphasis was encouraged by the technical difficulty of accurate calibration in this part of the spectrum, as well as by the absence of in-orbit calibration for Channels 1 and 2. This paper briefly reviews pre-launch calibration methodology for the AVHRR at the manufacturer's facility, and the absolute accuracy of the process, which is adequate only for the purpose of setting the gain of the instrument. A 1989 proposal by the National Institute for Standards and Technology (NIST), formerly known as the National Bureau of Standards (NBS), to improve the accuracy has not yet been funded. The importance of improving the accuracy is expected to increase in the future as new applications for quantitative measurements emerge in support of research into the mechanisms of global change. RP ABEL, P (reprint author), NOAA,NATL ENVIRONM SATELLITE DATA & INFORMAT SERV,WASHINGTON,DC 20233, USA. NR 4 TC 1 Z9 1 U1 0 U2 0 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 JUL PY 1991 VL 90 IS 1-3 BP 259 EP 263 PG 5 WC Geography, Physical; Geosciences, Multidisciplinary SC Physical Geography; Geology GA GD079 UT WOS:A1991GD07900042 ER PT J AU WALKER, JH CROMER, CL AF WALKER, JH CROMER, CL TI IMPROVING THE ACCURACY OF SPHERE-SOURCE CALIBRATIONS SO GLOBAL AND PLANETARY CHANGE LA English DT Article; Proceedings Paper CT CONF ON OPERATIONAL SATELLITES : SENTINELS FOR THE MONITORING OF CLIMATE AND GLOBAL CHANGE CY OCT 16-19, 1990 CL WASHINGTON, DC SP NATL OCEAN & ATMOSPHER ADMIN, US DEPT COMMERCE AB A new technique for improving the accuracy of radiance calibrations for large-area integrating-sphere sources has been investigated. Such sources are used to calibrate numerous aircraft and spacecraft remote sensing instruments. Recent measurements performed at NIST and NASA Goddard Space Flight Center have demonstrated that the uncertainty of sphere-source radiance measurements can be improved from the present 5-10% level to a 1-2% level. Silicon detectors with bandpass filters mounted in front of them and calibrated for absolute spectral responsivity can be used to confirm and to monitor the absolute radiance of a sphere source. RP WALKER, JH (reprint author), NATL INST STAND & TECHNOL,GAITHERSBURG,MD 20899, USA. 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 0921-8181 J9 GLOBAL PLANET CHANGE JI Glob. Planet. Change PD JUL PY 1991 VL 90 IS 1-3 BP 265 EP 269 PG 5 WC Geography, Physical; Geosciences, Multidisciplinary SC Physical Geography; Geology GA GD079 UT WOS:A1991GD07900043 ER PT J AU LAURITSON, L AF LAURITSON, L TI THE ACCESSIBILITY OF SATELLITE DATA AT THE NATIONAL CLIMATIC DATA CENTER (NCDC) SO GLOBAL AND PLANETARY CHANGE LA English DT Meeting Abstract RP LAURITSON, L (reprint author), NOAA,NATL ENVIRONM SATELLITE DATA & INFORMAT SERV,SDSD,5627 ALLENTOWN RD,COMP SPRINGS,MD 20233, 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 0921-8181 J9 GLOBAL PLANET CHANGE JI Glob. Planet. Change PD JUL PY 1991 VL 90 IS 1-3 BP 279 EP 280 PG 2 WC Geography, Physical; Geosciences, Multidisciplinary SC Physical Geography; Geology GA GD079 UT WOS:A1991GD07900045 ER PT J AU DECOTIIS, AG JANDHYALA, V GOODRUM, G AF DECOTIIS, AG JANDHYALA, V GOODRUM, G TI THE IMAGE LIBRARY AND BROWSE SYSTEM (ILABS) SO GLOBAL AND PLANETARY CHANGE LA English DT Article; Proceedings Paper CT CONF ON OPERATIONAL SATELLITES : SENTINELS FOR THE MONITORING OF CLIMATE AND GLOBAL CHANGE CY OCT 16-19, 1990 CL WASHINGTON, DC SP NATL OCEAN & ATMOSPHER ADMIN, US DEPT COMMERCE AB The National Climatic Data Center (NCDC) currently maintains an AVHRR image Browse Library. This facility is used extensively to view and select AVHRR data for retrospective use. Inadequacies in the old browse system motivated the NCDC to develop the Image Library and Browse System (ILABS). The ILABS consists of a mainframe software subsystem that produces display-ready imagery from AVHRR 1b data sets and PC based work stations to catalog, store, retrieve, and display AVHRR browse imagery. RP DECOTIIS, AG (reprint author), NOAA,NATL ENVIRONM SATELLITE DATA & INFORMAT SERV,CTR NATL CLIMAT DATA,DIV SATELLITE DATA SERV,CAMP SPRINGS,MD 20233, 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 0921-8181 J9 GLOBAL PLANET CHANGE JI Glob. Planet. Change PD JUL PY 1991 VL 90 IS 1-3 BP 281 EP 285 PG 5 WC Geography, Physical; Geosciences, Multidisciplinary SC Physical Geography; Geology GA GD079 UT WOS:A1991GD07900046 ER PT J AU METCALF, K AF METCALF, K TI AN ONLINE INVENTORY OF NCDCS POLAR ORBITING SATELLITE DATA SO GLOBAL AND PLANETARY CHANGE LA English DT Meeting Abstract RP METCALF, K (reprint author), NCDC,SDSD,DATA SERV BRANCH,5627 ALLENTOWN RD,CAMP SPRINGS,MD 20233, 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 0921-8181 J9 GLOBAL PLANET CHANGE JI Glob. Planet. Change PD JUL PY 1991 VL 90 IS 1-3 BP 287 EP 287 PG 1 WC Geography, Physical; Geosciences, Multidisciplinary SC Physical Geography; Geology GA GD079 UT WOS:A1991GD07900047 ER PT J AU HUSSEY, WJ SCHNEIDER, SR GIRD, RS NEEDHAM, BH AF HUSSEY, WJ SCHNEIDER, SR GIRD, RS NEEDHAM, BH TI NOAA SATELLITE OBSERVING SYSTEMS - STATUS AND PLANS SO GLOBAL AND PLANETARY CHANGE LA English DT Article; Proceedings Paper CT CONF ON OPERATIONAL SATELLITES : SENTINELS FOR THE MONITORING OF CLIMATE AND GLOBAL CHANGE CY OCT 16-19, 1990 CL WASHINGTON, DC SP NATL OCEAN & ATMOSPHER ADMIN, US DEPT COMMERCE AB NOAA's National Environmental Satellite, Data, and Information Service (NESDIS) operates separate series of environmental monitoring satellites in polar and geostationary orbits. Two geostationary spacecraft are normally in operation: one stationed at 75-degrees-E longitude (GOES-EAST), and one stationed at 135-degrees-W longitude (GOES-WEST). Owing to a combination of premature in-orbit failures and a launch failure there is only one GOES satellite currently operational, GOES-7, which is migrated between 95-degrees and 105-degrees-W longitude depending upon season. GOES-7 was launched in February 1987. Its primary observing instrument is a combined imager/sounder, the VISSR Atmospheric Sounder (VAS). The first in the next series of GOES satellites, (GOES 1-M), is scheduled for launch in 1992. The major upgrade over the current GOES satellites will be the introduction of simultaneous imaging and sounding capability and improvements in imaging IR and sounding resolution. Because of the long lead times necessary in designing and building new systems, NOAA, in cooperation with NASA, has already begun the planning and study process for the GOES-N series of satellites, which will fly early in the next century. NOAA operates a two polar satellite system with equatorial nodal crossing times of 0730 (descending) and 1345 (ascending). The current operational satellites are NOAA-10 (AM) and NOAA-11 (PM). The next in the series (NOAA-D, which will become NOAA-12 once operational) is scheduled for launch in early summer 1991. The instruments onboard are used to make global measurements of numerous parameters such as atmospheric temperature, water vapor, ozone, sea surface temperature, sea ice, and vegetation. The NOAA K-N series of satellites, scheduled for deployment in the mid 1990's, will provide upgraded imaging and sounding capability. The imager will be enhanced to include a sixth channel for cloud/ice descrimination. A 15 channel advanced microwave sounder will be manifested for atmospheric temperature retrievals, and a seperate 5 channel advanced microwave sounder will be used for atmospheric water vapor retrievals. The polar program will undergo major changes beginning in the late 1990's. The morning polar metsat service will become the responsibility of the Europeans with NOAA providing an operational sensor payload. The afternoon metsat service will be continued by NOAA with a new block of satellites and instruments beginning at NOAA-O. NOAA will also be closely cooperating with NASA in this time frame. A number of the instruments on NASA's Earth Observing System (EOS) platforms, scheduled for launch beginning in the late 1990's, have been designated "prototype operational" and may become candidates for eventual flight on NOAA operational spacecraft. RP HUSSEY, WJ (reprint author), NOAA,NATL ENVIRONM SATELLITE DATA & INFORMAT SERV,DEPT COMMERCE,OFF SYST DEV,WASHINGTON,DC 20233, USA. NR 0 TC 0 Z9 0 U1 1 U2 1 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0921-8181 J9 GLOBAL PLANET CHANGE JI Glob. Planet. Change PD JUL PY 1991 VL 90 IS 1-3 BP 289 EP 295 PG 7 WC Geography, Physical; Geosciences, Multidisciplinary SC Physical Geography; Geology GA GD079 UT WOS:A1991GD07900048 ER PT J AU BOND, LJ CLARK, R AF BOND, LJ CLARK, R TI RESPONSE OF HORIZONTAL AXIS EDDY-CURRENT COILS TO LAYERED MEDIA - A THEORETICAL AND EXPERIMENTAL-STUDY SO IEE PROCEEDINGS-A-SCIENCE MEASUREMENT AND TECHNOLOGY LA English DT Letter DE EDDY CURRENTS; ELECTROMAGNETIC THEORY; INSTRUMENTATION AND MEASURING SCIENCE AB Following the publication of our paper, IEE Proc. A, 1990, 137, (3), pp. 141-146, a letter was received from Prof. J.R. Wait giving details of work where he had considered the case of a horizontal magnetic dipole above a layer [1]. We thank him for drawing to our attention to this work in the field of geo-electromagnetism. C1 NATL INST STAND & TECHNOL,BOULDER,CO 80303. ROLLS ROYCE & ASSOCIATES LTD,NDE DEV DEPT,DERBY DE2 8BJ,ENGLAND. RP BOND, LJ (reprint author), UNIV COLORADO,CAMPUS BOX 427,BOULDER,CO 80309, USA. NR 2 TC 0 Z9 0 U1 0 U2 2 PU IEE-INST ELEC ENG PI HERTFORD PA MICHAEL FARADAY HOUSE SIX HILLS WAY STEVENAGE, HERTFORD, ENGLAND SG1 2AY SN 0143-702X J9 IEE PROC-A PD JUL PY 1991 VL 138 IS 4 BP 248 EP 248 PG 1 WC Engineering, Electrical & Electronic SC Engineering GA FU560 UT WOS:A1991FU56000006 ER PT J AU FLEMING, HE GRODY, NC KRATZ, EJ AF FLEMING, HE GRODY, NC KRATZ, EJ TI THE FORWARD PROBLEM AND CORRECTIONS FOR THE SSM/T SATELLITE MICROWAVE TEMPERATURE SOUNDER SO IEEE TRANSACTIONS ON GEOSCIENCE AND REMOTE SENSING LA English DT Article ID MODEL AB Physical algorithms for retrieving temperature profiles explicitly employ the physics of radiative transfer. Consequently, it is necessary to do the forward problem accurately before attempting the retrieval problem. This paper discusses the various problems that arise, and their solutions, in doing forward calculations over oceans. These problems include that of determining: When the measurements are cloud contaminated, the amount of liquid water in the fields of view, the surface emissivity under both clear and cloudy conditions, corrections for liquid water contamination of the measurements, adjustments for deficiencies in the radiative transfer model, and compensation for measurement discrepancies by using shrinkage estimation. These procedures are developed for SSM/T data and their validity is checked by comparing the forward calculations with the corresponding satellite measurements. Application of the procedures to an independent data set confirms their veracity. C1 SM SYST & RES CORP,LANDOVER,MD 20785. RP FLEMING, HE (reprint author), NOAA,NATL ENVIRONM SATELLITE DATA & INFORMAT SERV,SATELLITE RES LAB,WASHINGTON,DC 20233, USA. NR 15 TC 11 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 0196-2892 J9 IEEE T GEOSCI REMOTE JI IEEE Trans. Geosci. Remote Sensing PD JUL PY 1991 VL 29 IS 4 BP 571 EP 583 DI 10.1109/36.135819 PG 13 WC Geochemistry & Geophysics; Engineering, Electrical & Electronic; Remote Sensing; Imaging Science & Photographic Technology SC Geochemistry & Geophysics; Engineering; Remote Sensing; Imaging Science & Photographic Technology GA FX027 UT WOS:A1991FX02700011 ER PT J AU BANJANIN, ZB ZRNIC, DS AF BANJANIN, ZB ZRNIC, DS TI CLUTTER REJECTION FOR DOPPLER WEATHER RADARS WHICH USE STAGGERED PULSES SO IEEE TRANSACTIONS ON GEOSCIENCE AND REMOTE SENSING LA English DT Article ID AMBIGUITY RESOLUTION AB Several methods for canceling ground clutter in Doppler weather radars which operate with staggered PRT's are investigated. A scheme is developed which consists of two filters that operate sequentially, so that the overall filter is time-varying, with periodically changing coefficients. This filter is analyzed theoretically and through simulations for a stagger ratio of 3/2, which extends the unambiguous velocity interval. The amplitude characteristic of the filter over this interval is very good, but the phase characteristic, which is nonlinear in a small part of the interval, requires that a special decision logic be used for velocity estimation. At an SNR of 10 dB, mean velocity estimates at the output have average errors smaller than 3.5% (i.e., 1.75 m s-1 for the extended unambiguous interval of 2-nu-m = 50 m s-1); thus the scheme could be suitable for operation in environments with ground clutter. C1 UNIV OKLAHOMA,NATL SEVERE STORMS LAB,DOPPLER RADAR & REMOTE SENSING RES GRP,NORMAN,OK 73019. UNIV OKLAHOMA,COOPERAT INST MESOSCALE METEOROL STUDIES,NORMAN,OK 73019. NR 12 TC 13 Z9 14 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 0196-2892 J9 IEEE T GEOSCI REMOTE JI IEEE Trans. Geosci. Remote Sensing PD JUL PY 1991 VL 29 IS 4 BP 610 EP 620 DI 10.1109/36.135823 PG 11 WC Geochemistry & Geophysics; Engineering, Electrical & Electronic; Remote Sensing; Imaging Science & Photographic Technology SC Geochemistry & Geophysics; Engineering; Remote Sensing; Imaging Science & Photographic Technology GA FX027 UT WOS:A1991FX02700015 ER PT J AU CHEN, DX BRUG, JA GOLDFARB, RB AF CHEN, DX BRUG, JA GOLDFARB, RB TI DEMAGNETIZING FACTORS FOR CYLINDERS SO IEEE TRANSACTIONS ON MAGNETICS LA English DT Article ID FERROMAGNETIC CYLINDERS; MAGNETOSTATIC ENERGY; FIELDS; MAGNETIZATION AB Fluxmetric (ballistic) and magnetometric demagnetizing factors N(f) and N(m) for cylinders as functions of susceptibility-chi and the ratio-gamma of length to diameter have been evaluated. Using a one-dimensional model when gamma greater-than-or-equal-to 10, N(f) was calculated for -1 less-than-or-equal-to chi < infinity and N(m) was calculated for chi --> infinity. Using a two-dimensional model when 0.01 less-than-or-equal-to gamma less-than-or-equal-to 50, an important range for magnetometer measurements, N(m) and N(f) were calculated for -1 less-than-or-equal-to chi < infinity. Demagnetizing factors for chi < 0 are applicable to superconductors. For chi = 0, suitable for weakly magnetic or saturated ferromagnetic materials, N(f) and N(m) were computed exactly using inductance formulas. C1 NATL INST STAND & TECHNOL,SUPER COND & MAGNET MEASUREMENT GRP,BOULDER,CO 80303. RP CHEN, DX (reprint author), NATL INST STAND & TECHNOL,DIV ELECTROMAGNET TECHNOL,BOULDER,CO 80303, USA. RI Goldfarb, Ronald/A-5493-2011 OI Goldfarb, Ronald/0000-0002-1942-7974 NR 84 TC 277 Z9 280 U1 3 U2 39 PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017-2394 SN 0018-9464 J9 IEEE T MAGN JI IEEE Trans. Magn. PD JUL PY 1991 VL 27 IS 4 BP 3601 EP 3619 DI 10.1109/20.102932 PG 19 WC Engineering, Electrical & Electronic; Physics, Applied SC Engineering; Physics GA GP593 UT WOS:A1991GP59300012 ER PT J AU MARKS, RB AF MARKS, RB TI A MULTILINE METHOD OF NETWORK ANALYZER CALIBRATION SO IEEE TRANSACTIONS ON MICROWAVE THEORY AND TECHNIQUES LA English DT Article ID LEAST-SQUARES; 6-PORT; STANDARDS AB This paper presents a new method for the calibration of network analyzers. The essential feature is the use of multiple, redundant transmission line standards. The additional information provided by the redundant standards is used to minimize the effects of random errors, such as those caused by imperfect connector repeatability. The resulting method exhibits improvements in both accuracy and bandwidth over conventional methods. The basis of the statistical treatment is a linearized error analysis of the TRL (thru-reflect-line) calibration method. This analysis, presented here, is useful in the assessment of calibration accuracy. It also yields new results relevant to the choice of standards. RP NATL INST STAND & TECHNOL, MAIL CODE 81301, 325 BROADWAY, BOULDER, CO 80303 USA. NR 12 TC 504 Z9 513 U1 0 U2 12 PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC PI PISCATAWAY PA 445 HOES LANE, PISCATAWAY, NJ 08855-4141 USA SN 0018-9480 EI 1557-9670 J9 IEEE T MICROW THEORY JI IEEE Trans. Microw. Theory Tech. PD JUL PY 1991 VL 39 IS 7 BP 1205 EP 1215 DI 10.1109/22.85388 PG 11 WC Engineering, Electrical & Electronic SC Engineering GA FP950 UT WOS:A1991FP95000018 ER PT J AU SPARKS, LL AF SPARKS, LL TI PROCEEDINGS OF THE 10TH INTERNATIONAL THERMAL-EXPANSION SYMPOSIUM - FOREWORD SO INTERNATIONAL JOURNAL OF THERMOPHYSICS LA English DT Editorial Material RP SPARKS, LL (reprint author), NATL INST STAND & TECHNOL,BOULDER,CO 80303, USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU PLENUM PUBL CORP PI NEW YORK PA 233 SPRING ST, NEW YORK, NY 10013 SN 0195-928X J9 INT J THERMOPHYS JI Int. J. Thermophys. PD JUL PY 1991 VL 12 IS 4 BP 609 EP 609 DI 10.1007/BF00534215 PG 1 WC Thermodynamics; Chemistry, Physical; Mechanics; Physics, Applied SC Thermodynamics; Chemistry; Mechanics; Physics GA FV873 UT WOS:A1991FV87300001 ER PT J AU LEDBETTER, H AF LEDBETTER, H TI THERMAL-EXPANSION AND ELASTIC-CONSTANTS SO INTERNATIONAL JOURNAL OF THERMOPHYSICS LA English DT Article; Proceedings Paper CT 10TH INTERNATIONAL SYMP ON THERMAL EXPANSION CY JUN 06-07, 1989 CL BOULDER, CO SP NIST DE CRYSTALS; DEBYE TEMPERATURE; EINSTEIN TEMPERATURE; ELASTIC CONSTANTS; GRUNEISEN PARAMETER; LOW TEMPERATURES; THERMAL EXPANSION; THERMAL EXPANSIVITY; ZERO-POINT ENERGY AB We give a simple, useful relationship between thermal expansion, DELTA-V/V, and elastic constants. The relationship permits estimation of thermal expansion from only elastic constants (second order and third order) and atomic volume. Elastic-constant temperature dependence is not required. We test the relationship for a variety of crystalline solids. Considering the 0-293 K region, measurement-calculation disagreement ranges from less than 1 to 15%. The model permits extrapolation of high-temperature (near-linear) thermal expansion to zero temperature. RP LEDBETTER, H (reprint author), NATL INST STAND & TECHNOL,MAT SCI & ENGN LAB,BOULDER,CO 80303, USA. NR 8 TC 12 Z9 12 U1 0 U2 5 PU PLENUM PUBL CORP PI NEW YORK PA 233 SPRING ST, NEW YORK, NY 10013 SN 0195-928X J9 INT J THERMOPHYS JI Int. J. Thermophys. PD JUL PY 1991 VL 12 IS 4 BP 637 EP 642 DI 10.1007/BF00534219 PG 6 WC Thermodynamics; Chemistry, Physical; Mechanics; Physics, Applied SC Thermodynamics; Chemistry; Mechanics; Physics GA FV873 UT WOS:A1991FV87300005 ER PT J AU MIILLER, AP CEZAIRLIYAN, A AF MIILLER, AP CEZAIRLIYAN, A TI INTERFEROMETRIC-TECHNIQUE FOR THE SUBSECOND MEASUREMENT OF THERMAL-EXPANSION AT HIGH-TEMPERATURES - APPLICATIONS TO REFRACTORY-METALS SO INTERNATIONAL JOURNAL OF THERMOPHYSICS LA English DT Article; Proceedings Paper CT 10TH INTERNATIONAL SYMP ON THERMAL EXPANSION CY JUN 06-07, 1989 CL BOULDER, CO SP NIST DE HIGH TEMPERATURE; INTERFEROMETRY; IRON; MOLYBDENUM; NIOBIUM; PULSE HEATING; SOLID-SOLID PHASE TRANSFORMATIONS; TANTALUM; THERMAL EXPANSION; TUNGSTEN AB A high-speed interferometric technique has been developed at the National Institute of Standards and Technology to measure thermal expansion of metals between room temperature and temperatures primarily in the range 1500 K to near their melting points. The basic method involves resistively heating the specimen from room temperature up to and through the temperature range of interest in less than 1 s by passing an electrical current pulse through it and simultaneously measuring, with submillisecond resolution, the specimen temperature by means of a high-speed photoelectric pyrometer and the shift in the fringe pattern produced by a Michelson-type interferometer. The polarized beam from a He-Ne laser in the interferometer is split into two components, one which undergoes successive reflections from highly polished flats on opposite sides of the specimen and one which serves as the reference beam. The linear thermal expansion of the specimen is determined from the cumulative fringe shift corresponding to each measured temperature. The technique is capable of measuring linear thermal expansion with a maximum estimated uncertainty which ranges from about 1 % at 2000 K to approximately 2 % at 3600 K. Measurements have been performed on the refractory metals, niobium, molybdenum, tantalum, and tungsten, yielding thermal expansion data in the temperature range 1500 K up to near their respective melting points. Also, the technique has been used to follow the rapid dimensional changes that occur during solid-solid phase transformations; in particular, the alpha --> gamma transformation in iron has been studied. RP MIILLER, AP (reprint author), NATL INST STAND & TECHNOL,DIV THERMOPHYS,GAITHERSBURG,MD 20890, USA. NR 10 TC 11 Z9 11 U1 0 U2 1 PU PLENUM PUBL CORP PI NEW YORK PA 233 SPRING ST, NEW YORK, NY 10013 SN 0195-928X J9 INT J THERMOPHYS JI Int. J. Thermophys. PD JUL PY 1991 VL 12 IS 4 BP 643 EP 656 DI 10.1007/BF00534220 PG 14 WC Thermodynamics; Chemistry, Physical; Mechanics; Physics, Applied SC Thermodynamics; Chemistry; Mechanics; Physics GA FV873 UT WOS:A1991FV87300006 ER PT J AU EDSINGER, RE SCHOOLEY, JF AF EDSINGER, RE SCHOOLEY, JF TI A HIGH-ACCURACY DILATOMETER FOR THE RANGE-20-DEGREES-C TO 700-DEGREES-C SO INTERNATIONAL JOURNAL OF THERMOPHYSICS LA English DT Article; Proceedings Paper CT 10TH INTERNATIONAL SYMP ON THERMAL EXPANSION CY JUN 06-07, 1989 CL BOULDER, CO SP NIST DE DILATOMETRY; HEAT PIPE; LINEAR THERMAL EXPANSION; THERMOMETRY AB We have constructed a linear-thermal expansion apparatus that employs a potassium-loaded heat pipe to provide a homogeneous temperature environment for the sample and utilizes the Merritt-Saunders (optical interferometric) method of observing its expansion. The apparatus is similar in many respects to one described previously. Temperature regulation and measurement are accomplished through the use of a dedicated laboratory microcomputer operating with a simple program. Two platinum resistance thermometers, read automatically by a digital resistance bridge, provide, on command, both the temperature of the heat pipe and that of the sample chamber. Changes in sample length are determined from measurements of the corresponding changes of optical fringes from a Fizeau interferometer as recorded on film. The coefficients of thermal expansion of two Pt-Rh alloy samples determined using the present apparatus agree at the +/- 2 ppm level with those determined for a similar sample using the previous apparatus. RP EDSINGER, RE (reprint author), NATL INST STAND & TECHNOL,DIV TEMP & PRESSURE,GAITHERSBURG,MD 20899, USA. NR 12 TC 3 Z9 3 U1 0 U2 1 PU PLENUM PUBL CORP PI NEW YORK PA 233 SPRING ST, NEW YORK, NY 10013 SN 0195-928X J9 INT J THERMOPHYS JI Int. J. Thermophys. PD JUL PY 1991 VL 12 IS 4 BP 665 EP 677 DI 10.1007/BF00534222 PG 13 WC Thermodynamics; Chemistry, Physical; Mechanics; Physics, Applied SC Thermodynamics; Chemistry; Mechanics; Physics GA FV873 UT WOS:A1991FV87300008 ER PT J AU KIRBY, RK AF KIRBY, RK TI PLATINUM - A THERMAL-EXPANSION REFERENCE MATERIAL SO INTERNATIONAL JOURNAL OF THERMOPHYSICS LA English DT Article; Proceedings Paper CT 10TH INTERNATIONAL SYMP ON THERMAL EXPANSION CY JUN 06-07, 1989 CL BOULDER, CO SP NIST DE DILATOMETRY; PLATINUM; REFERENCE MATERIAL; THERMAL EXPANSION AB Platinum has a face-centered cubic crystal structure and does not have any phase changes between absolute zero and its melting point at 2045 K. High-purity platinum can be readily obtained in rod and sheet form and thus provides an excellent thermal expansion standard. Five investigations that used accurate and precise experimental techniques were used to establish analytical expressions for the coefficients of thermal expansion from 0 to 1800 K. RP KIRBY, RK (reprint author), NBS,GAITHERSBURG,MD 20899, USA. NR 19 TC 33 Z9 33 U1 0 U2 11 PU PLENUM PUBL CORP PI NEW YORK PA 233 SPRING ST, NEW YORK, NY 10013 SN 0195-928X J9 INT J THERMOPHYS JI Int. J. Thermophys. PD JUL PY 1991 VL 12 IS 4 BP 679 EP 685 DI 10.1007/BF00534223 PG 7 WC Thermodynamics; Chemistry, Physical; Mechanics; Physics, Applied SC Thermodynamics; Chemistry; Mechanics; Physics GA FV873 UT WOS:A1991FV87300009 ER PT J AU LEDBETTER, H AUSTIN, M AF LEDBETTER, H AUSTIN, M TI THERMAL-EXPANSION OF AN SIC PARTICLE-REINFORCED ALUMINUM COMPOSITE SO INTERNATIONAL JOURNAL OF THERMOPHYSICS LA English DT Article; Proceedings Paper CT 10TH INTERNATIONAL SYMP ON THERMAL EXPANSION CY JUN 06-07, 1989 CL BOULDER, CO SP NIST DE ALUMINUM; COMPOSITE; ELASTIC CONSTANTS; LOW TEMPERATURES; SILICON CARBIDE; THERMAL EXPANSION; THERMAL EXPANSIVITY AB Using a push-rod dilatometer, we measured between 76 and 390 K the thermal expansion of a particle-reinforced-composite wrought plate obtained by powder-metallurgy methods. The particles, 30% by volume, consisted of monocrystals of alpha-SiC with sizes near 10-mu-m. The matrix consisted of a 6061 aluminum alloy with original particle sizes near 20-mu-m. We found the perpendicular thermal expansivity, alpha-3, higher by 26% than the in-plane thermal expansivity, alpha-1 congruent-to alpha-2. These values differ from a rule-of-mixture prediction by -3 and -23%, respectively. All three alpha-i components lie outside the Rosen-Hashin bounds. Levin's isotropic model agrees within 10% with the alpha-1-alpha-2-alpha-3 average. Both the anisotropy and the bounds violation result from microstructural non-homogeneity arising from processing. Rosen and Hashin's transverse-isotropic-symmetry relationships account approximately for these effects by introducing the anisotropic elastic constants. Using neutron diffraction, we determined that the SiC particles are textureless. RP LEDBETTER, H (reprint author), NATL INST STAND & TECHNOL,MAT SCI & ENGN LAB,BOULDER,CO 80303, USA. NR 8 TC 4 Z9 4 U1 0 U2 2 PU PLENUM PUBL CORP PI NEW YORK PA 233 SPRING ST, NEW YORK, NY 10013 SN 0195-928X J9 INT J THERMOPHYS JI Int. J. Thermophys. PD JUL PY 1991 VL 12 IS 4 BP 731 EP 739 DI 10.1007/BF00534228 PG 9 WC Thermodynamics; Chemistry, Physical; Mechanics; Physics, Applied SC Thermodynamics; Chemistry; Mechanics; Physics GA FV873 UT WOS:A1991FV87300014 ER PT J AU GEIST, J LOWNEY, JR JAMES, CR ROBINSON, AM AF GEIST, J LOWNEY, JR JAMES, CR ROBINSON, AM TI TESTING THE ACCURACY OF CALCULATED EQUILIBRIUM CARRIER CONCENTRATIONS IN THE PRESENCE OF SURFACE FIELDS SO JOURNAL OF APPLIED PHYSICS LA English DT Article AB Simple analytic expressions for the one-dimensional, majority-carrier concentration in a uniformly doped, semi-infinite semiconductor with a charge-accumulated front surface are derived. These expressions are based on the assumption that the effective intrinsic carrier concentration depends only upon the concentration of the majority dopant. Within the framework of this assumption, the expressions derived here are rigorously accurate for intrinsic material, and are accurate to well within 100 parts per million (ppm) for doping concentrations above 10(12) cm-3. The results of calculations of the majority-carrier concentration carried out using these expressions and using a widely available one-dimensional semiconductor device modeling program are compared to illustrate how these expressions are used for testing the accuracy of iterative solutions of the drift-diffusion equations in the presence of surface fields. C1 UNIV ALBERTA,DEPT ELECT ENGN,EDMONTON T6G 2G7,ALBERTA,CANADA. RP GEIST, J (reprint author), NATL INST STANDARDS & TECHNOL,DIV SEMICOND ELECTR,GAITHERSBURG,MD 20899, USA. RI Geist, Jon/D-5386-2013; OI Geist, Jon/0000-0001-7749-318X NR 7 TC 1 Z9 1 U1 0 U2 2 PU AMER INST PHYSICS PI WOODBURY PA CIRCULATION FULFILLMENT DIV, 500 SUNNYSIDE BLVD, WOODBURY, NY 11797-2999 SN 0021-8979 J9 J APPL PHYS JI J. Appl. Phys. PD JUL 1 PY 1991 VL 70 IS 1 BP 236 EP 242 DI 10.1063/1.350317 PG 7 WC Physics, Applied SC Physics GA FV069 UT WOS:A1991FV06900037 ER PT J AU MORELAND, J RICE, P AF MORELAND, J RICE, P TI TUNNELING STABILIZED, MAGNETIC FORCE MICROSCOPY WITH A GOLD-COATED, NICKEL-FILM TIP SO JOURNAL OF APPLIED PHYSICS LA English DT Note ID LONGITUDINAL RECORDING MEDIA; RESOLUTION AB Tunneling stabilized magnetic force microscopy (TSMFM) is done with a scanning tunneling microscope having a flexible magnetic tip. TSMFM can be used to generate maps of magnetic records with submicrometer resolution. We find that Au-coated, Ni-film tips made from a free-standing 0.5-mu-m-thick Ni film can be used as a noninvasive probe for imaging magnetic bit patterns on the surfaces of computer hard and floppy disks, and computer tape. This variant of scanning tunneling microscopy shows promise as a viable tool for diagnostic use in the magnetic recording industry. RP MORELAND, J (reprint author), NATL INST STANDARDS & TECHNOL,DIV ELECTROMAGNET TECHNOL,BOULDER,CO 80303, USA. NR 15 TC 14 Z9 14 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 JUL 1 PY 1991 VL 70 IS 1 BP 520 EP 522 DI 10.1063/1.350266 PG 3 WC Physics, Applied SC Physics GA FV069 UT WOS:A1991FV06900087 ER PT J AU HARVEY, AH AF HARVEY, AH TI PHASE-EQUILIBRIA AND CRITICAL LINES IN MODEL WATER SALT MIXTURES SO JOURNAL OF CHEMICAL PHYSICS LA English DT Article ID MEAN-SPHERICAL APPROXIMATION; IONIC FLUIDS; CRITICAL-BEHAVIOR; COEXISTENCE CURVE; SYSTEM NACL-H2O; CRITICAL REGION; DILUTE NACL; ELECTROLYTES; THERMODYNAMICS; DIPOLES AB The mean spherical approximation solution for the thermodynamics of a mixture of equal-sized dipolar hard spheres and charged hard spheres is used to calculate phase equilibria and critical lines. The binary system is characterized by the dimensionless ratio of the dipolar strength to the strength of the charges. At high values of this ratio, the critical curve is interrupted by a liquid-liquid equilibrium and the phase diagram (under the usual classification scheme) is type III. As the ratio is lowered, the critical curve becomes continuous; this is type I or II behavior. The continuous critical line is maintained until the critical temperature of the ionic component exceeds that of the dipolar component by a factor of approximately 3.56; such a lengthy unbroken critical line is unusual in ordinary fluid systems but is observed in many mixtures of water with strong electrolytes. At sufficiently low values of the dimensionless ratio, the critical line is interrupted very near the critical point of the dipolar component; these systems exhibit type IV or V behavior. The simple model used here reproduces the qualitative features of the phase diagrams of real water/salt systems. Insights from the model suggest at least partial explanations for the unusually long unbroken critical lines observed in many of these systems. C1 NATL INST STANDARDS & TECHNOL,DIV THERMOPHYS,GAITHERSBURG,MD 20899. NR 42 TC 25 Z9 25 U1 1 U2 7 PU AMER INST PHYSICS PI WOODBURY PA CIRCULATION FULFILLMENT DIV, 500 SUNNYSIDE BLVD, WOODBURY, NY 11797-2999 SN 0021-9606 J9 J CHEM PHYS JI J. Chem. Phys. PD JUL 1 PY 1991 VL 95 IS 1 BP 479 EP 484 DI 10.1063/1.461448 PG 6 WC Chemistry, Physical; Physics, Atomic, Molecular & Chemical SC Chemistry; Physics GA FT847 UT WOS:A1991FT84700047 ER PT J AU DESROSIERS, MF AF DESROSIERS, MF TI ELECTRON-SPIN-RESONANCE FOR MONITORING RADIATION-PROCESSED MEATS CONTAINING BONE SO JOURNAL OF FOOD SCIENCE LA English DT Note ID IRRADIATED FOOD; SPECTROSCOPY; DOSIMETRY AB Electron spin resonance (ESR) spectroscopy assessed the dose absorbed by radiation-processed meats (containing bone). Additive re-irradiation of the bone generated a dose response curve which could then be used to assess the initial dose from irradiation. An exponential fit to the ESR response to absorbed dose provided a good estimate of initial dose and was a reasonable physical description of the response from absorption of ionizing radiation by bone. These data have implications for regulation of the industry. RP DESROSIERS, MF (reprint author), NATL INST STAND & TECHNOL,CTR RADIAT RES,GAITHERSBURG,MD 20899, USA. NR 12 TC 21 Z9 22 U1 1 U2 1 PU INST FOOD TECHNOLOGISTS PI CHICAGO PA SUITE 300 221 N LASALLE ST, CHICAGO, IL 60601-1291 SN 0022-1147 J9 J FOOD SCI JI J. Food Sci. PD JUL-AUG PY 1991 VL 56 IS 4 BP 1104 EP 1105 DI 10.1111/j.1365-2621.1991.tb14653.x PG 2 WC Food Science & Technology SC Food Science & Technology GA GC086 UT WOS:A1991GC08600057 ER PT J AU PENSABENE, JW FIDDLER, W GATES, RA HALE, M JAHNCKE, M GOOCH, J AF PENSABENE, JW FIDDLER, W GATES, RA HALE, M JAHNCKE, M GOOCH, J TI NORMAL-NITROSOTHIAZOLIDINE AND ITS 4-CARBOXYLIC ACID IN FRANKFURTERS CONTAINING ALASKA POLLOCK SO JOURNAL OF FOOD SCIENCE LA English DT Note ID N-NITROSO COMPOUNDS; CURED MEAT-PRODUCTS; N-NITROSOTHIAZOLIDINE-4-CARBOXYLIC ACID; FROZEN STORAGE; FISH; BACON; NITROSAMINES; MUSCLE; PROTEIN; KASHMIR AB In marine fish of the gadoid family trimethylamine oxide can decompose to formaldehyde. It can then react with cysteine and cysteamine, that may in turn react with nitrite, if present, to form N-nitrosothiazolidine-4-carboxylic acid (NTHZC) and N-nitrosothiazolidine (NTHZ). The NTHZC and NTHZ content of Alaska pollock surimi-meat frankfurters were similar to or lower than those found in an all-meat control, even at 50% substitution. No correlation was found between age of the fish protein prior to processing into surimi meat frankfurters and any measured variables. C1 NATL MARINE FISHERIES SERV,CHARLESTON,SC 29412. RP PENSABENE, JW (reprint author), USDA ARS,EASTERN REG RES CTR,600 E MERMAID LANE,PHILADELPHIA,PA 19118, USA. NR 30 TC 6 Z9 6 U1 0 U2 0 PU INST FOOD TECHNOLOGISTS PI CHICAGO PA SUITE 300 221 N LASALLE ST, CHICAGO, IL 60601-1291 SN 0022-1147 J9 J FOOD SCI JI J. Food Sci. PD JUL-AUG PY 1991 VL 56 IS 4 BP 1108 EP 1110 DI 10.1111/j.1365-2621.1991.tb14655.x PG 3 WC Food Science & Technology SC Food Science & Technology GA GC086 UT WOS:A1991GC08600059 ER PT J AU HAMANN, IM HERZFELD, UC AF HAMANN, IM HERZFELD, UC TI ON THE EFFECTS OF PREANALYSIS STANDARDIZATION SO JOURNAL OF GEOLOGY LA English DT Note AB In spatial analysis the data are often assumed to be normally distributed, which may not be a property of the earth science phenomenon studied. Different types of pre-analysis standardization lead to disparate qualitative or quantitative interpretations: The standardization techniques compared are Gaussian normalization and proportion of range transformation. For two case studies: (1) oceanographic data investigated with Q-mode factor analysis, and (2) stratigraphic data analyzed by algebraic map comparison, proportion of range standardization is more appropriate than Gaussian standardization, in view of the scientific interpretation, with the results of factor analysis generally being more sensitive to pre-analysis standardization than the results of map comparison. RP HAMANN, IM (reprint author), NOAA,NATL MARINE FISHERIES,2570 DOLE ST,HONOLULU,HI 96822, USA. NR 13 TC 5 Z9 5 U1 0 U2 0 PU UNIV CHICAGO PRESS PI CHICAGO PA 5720 S WOODLAWN AVE, CHICAGO, IL 60637 SN 0022-1376 J9 J GEOL JI J. Geol. PD JUL PY 1991 VL 99 IS 4 BP 621 EP 631 PG 11 WC Geology SC Geology GA FW415 UT WOS:A1991FW41500009 ER PT J AU COFFEY, HE AF COFFEY, HE TI GEOMAGNETIC AND SOLAR DATA SO JOURNAL OF GEOPHYSICAL RESEARCH-SPACE PHYSICS LA English DT Editorial Material RP COFFEY, HE (reprint author), NOAA,WORLD DATA CTR SOLAR TERR PHYS A,BOULDER,CO 80303, USA. NR 0 TC 1 Z9 1 U1 0 U2 0 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 SN 0148-0227 J9 J GEOPHYS RES JI J. Geophys. Res-Space Phys. PD JUL 1 PY 1991 VL 96 IS A7 BP 11647 EP 11647 DI 10.1029/91JA01549 PG 1 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA FW171 UT WOS:A1991FW17100058 ER PT J AU BAROUCH, E BRADIE, B FOWLER, HA AF BAROUCH, E BRADIE, B FOWLER, HA TI 3-DIMENSIONAL SIMULATIONS OF HIGH-RESOLUTION PHOTORESIST PROCESSING SO JOURNAL OF IMAGING SCIENCE LA English DT Article ID POSITIVE PHOTORESIST AB A computer simulation package for optical microlithography contains modules for the processing of positive photoresists in the three stages of aerial-image transfer, exposure-bleaching, and dissolution. Evolving and final resist profiles are displayed in three dimensions at several dissolution times, thus simulating real systems in their natural form. Results presented for a variety of examples demonstrate the robustness and versatility of the package. C1 CLARKSON UNIV,DEPT MATH & COMP SCI,POTSDAM,NY 13676. NATL INST STAND & TECHNOL,COMP & APPL MATH LAB,GAITHERSBURG,MD 20899. NR 26 TC 0 Z9 0 U1 0 U2 0 PU I S & T - SOC IMAGING SCIENCE TECHNOLOGY PI SPRINGFIELD PA 7003 KILWORTH LANE, SPRINGFIELD, VA 22151 SN 0031-8760 J9 J IMAGING SCI PD JUL-AUG PY 1991 VL 35 IS 4 BP 240 EP 251 PG 12 WC Imaging Science & Photographic Technology SC Imaging Science & Photographic Technology GA GD901 UT WOS:A1991GD90100006 ER PT J AU AVIRAM, I BENNETT, LH SWARTZENDRUBER, LJ SATIJA, II AF AVIRAM, I BENNETT, LH SWARTZENDRUBER, LJ SATIJA, II TI COMPLEX DYNAMICS IN THE BARKHAUSEN EFFECT SO JOURNAL OF MAGNETISM AND MAGNETIC MATERIALS LA English DT Article ID BLOCH WALL; MOTION; NOISE AB We propose and analyze a simple, almost exactly solvable model which simulates the motion of domain walls in a ferromagnet with impurities. The model is found to exhibit rather complex dynamics of the domain wall crossing a single impurity. In the range of parameters investigated here, the dynamics was found to depend sensitively on the parameters, but no chaotic dynamics on strange attractors was found. C1 NUCL RES CTR NEGEV,DEPT PHYS,IL-84190 BEER SHEVA,ISRAEL. GEORGE MASON UNIV,DEPT PHYS,FAIRFAX,VA 22030. RP AVIRAM, I (reprint author), NATL INST STAND & TECHNOL,GAITHERSBURG,MD 20899, USA. NR 17 TC 1 Z9 1 U1 0 U2 0 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0304-8853 J9 J MAGN MAGN MATER JI J. Magn. Magn. Mater. PD JUL PY 1991 VL 98 IS 1-2 BP 92 EP 98 DI 10.1016/0304-8853(91)90433-B PG 7 WC Materials Science, Multidisciplinary; Physics, Condensed Matter SC Materials Science; Physics GA GA324 UT WOS:A1991GA32400018 ER PT J AU BLACK, DR BURDETTE, HE KURIYAMA, M SPAL, RD AF BLACK, DR BURDETTE, HE KURIYAMA, M SPAL, RD TI DIFFRACTION IMAGING OF POLYCRYSTALLINE MATERIALS SO JOURNAL OF MATERIALS RESEARCH LA English DT Article AB A new diffraction imaging technique for the characterization of polycrystalline materials is proposed and applied to obtain direct information about individual grains and their size and shape distribution and, in turn, strains in these materials. Unlike traditional powder diffractometry, where divergent and focusing x-ray optics are essential to collect information from an ensemble of grains, the nearly parallel and monochromatic beam available from a synchrotron x-ray source is employed to observe and measure diffraction images from individual grains and component particles in consolidated materials prepared by various processes. Images can be recorded by traditional methods, such as film and pulse counting detectors, but modern image detectors, such as charge coupled device (CCD) detectors and image analyzers, make the proposed imaging technique more practical. Unlike traditional diffractometry, this new technique provides the ability to measure shape, size, and strain without model based analyses. The spatial distribution of strain within individual grains, displayed as a diffraction image (topograph), indicates the presence of defects, such as dislocations, subgrain boundaries, and precipitates, and sheds new light on the origins of residual strains (stresses) in industrial materials. The resolution of the imaging system used is limited to grains approximately 10-mu-m or larger due to diffraction broadening (approximately 20" from the size effect) and the resolution of the recording medium. RP BLACK, DR (reprint author), NATL INST STAND & TECHNOL,MAT SCI & ENGN LAB,GAITHERSBURG,MD 20899, USA. NR 8 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 JUL PY 1991 VL 6 IS 7 BP 1469 EP 1476 DI 10.1557/JMR.1991.1469 PG 8 WC Materials Science, Multidisciplinary SC Materials Science GA FV269 UT WOS:A1991FV26900011 ER PT J AU MASUDAJINDO, K TEWARY, VK THOMSON, R AF MASUDAJINDO, K TEWARY, VK THOMSON, R TI ATOMIC THEORY OF FRACTURE OF BRITTLE MATERIALS - APPLICATION TO COVALENT SEMICONDUCTORS SO JOURNAL OF MATERIALS RESEARCH LA English DT Article ID GREEN-FUNCTION; ELECTRONIC-PROPERTIES; SURFACE-STATES; SIMULATION; CRYSTALS; CRACKS AB Using the lattice Green's function approach and LCAO (linear combination of atomic orbitals) electron theory, we investigate the atomistic configuration and lattice trapping of cracks in Si. The LCAO electron theory coupled to second order perturbation theory (SOP) has been used to derive explicit expressions for the bond breaking nonlinear forces between Si atoms. We calculate the cracked lattice Green's functions for a crack on the (111) plane and lying in the (110) direction. With the nonlinear forces acting in a cohesive region near the crack tips, the crack structure is then calculated. The calculated structure possesses a crack opening at the Griffith load which should allow penetration of typical external molecules to the crack tip at the Griffith loading. Other consequences for chemical reactions at the crack tip are discussed in the light of these results. The lattice trapping is low, only a few percent of the Griffith load. C1 NATL INST STAND & TECHNOL,DIV MAT RELIABIL,BOULDER,CO 80303. NATL INST STAND & TECHNOL,MAT SCI & ENGN LAB,GAITHERSBURG,MD 20899. RP MASUDAJINDO, K (reprint author), TOKYO INST TECHNOL,DEPT MAT SCI & ENGN,MIDORI KU,YOKOHAMA,KANAGAWA 227,JAPAN. NR 30 TC 17 Z9 17 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 JUL PY 1991 VL 6 IS 7 BP 1553 EP 1566 DI 10.1557/JMR.1991.1553 PG 14 WC Materials Science, Multidisciplinary SC Materials Science GA FV269 UT WOS:A1991FV26900021 ER PT J AU KLEINER, I HOUGEN, JT SUENRAM, RD LOVAS, FJ GODEFROID, M AF KLEINER, I HOUGEN, JT SUENRAM, RD LOVAS, FJ GODEFROID, M TI THE GROUND TORSIONAL STATE OF ACETALDEHYDE SO JOURNAL OF MOLECULAR SPECTROSCOPY LA English DT Article ID MILLIMETER-WAVE SPECTRUM; INTERNAL-ROTATION ANALYSIS; MICROWAVE-SPECTRUM; ADDITIONAL MEASUREMENTS; CENTRIFUGAL-DISTORTION; METHANOL C1 UNIV LIBRE BRUXELLES,CHIM PHYS MOLEC LAB CP160,B-1050 BRUSSELS,BELGIUM. RP KLEINER, I (reprint author), NATL INST STAND & TECHNOL,DIV MOLEC PHYS,GAITHERSBURG,MD 20899, USA. NR 29 TC 46 Z9 46 U1 0 U2 4 PU ACADEMIC PRESS INC JNL-COMP SUBSCRIPTIONS PI SAN DIEGO PA 525 B ST, STE 1900, SAN DIEGO, CA 92101-4495 SN 0022-2852 J9 J MOL SPECTROSC JI J. Mol. Spectrosc. PD JUL PY 1991 VL 148 IS 1 BP 38 EP 49 DI 10.1016/0022-2852(91)90032-6 PG 12 WC Physics, Atomic, Molecular & Chemical; Spectroscopy SC Physics; Spectroscopy GA FR895 UT WOS:A1991FR89500004 ER PT J AU SUENRAM, RD FRASER, GT LOVAS, FJ GILLIES, CW AF SUENRAM, RD FRASER, GT LOVAS, FJ GILLIES, CW TI MICROWAVE-SPECTRA AND ELECTRIC-DIPOLE MOMENTS OF X4-SIGMA-1/2VO AND NBO SO JOURNAL OF MOLECULAR SPECTROSCOPY LA English DT Article ID VAPORIZED METAL-OXIDES; RARE-GAS COMPLEXES; ROTATIONAL SPECTRA; NIOBIUM OXIDE; SPECTROSCOPY; OCS; CLUSTERS; STATE; LAO; ZRO C1 RENSSELAER POLYTECH INST,DEPT CHEM,TROY,NY 12180. RP SUENRAM, RD (reprint author), NATL INST STAND & TECHNOL,DIV MOLEC PHYS,GAITHERSBURG,MD 20899, USA. NR 21 TC 47 Z9 47 U1 1 U2 3 PU ACADEMIC PRESS INC JNL-COMP SUBSCRIPTIONS PI SAN DIEGO PA 525 B ST, STE 1900, SAN DIEGO, CA 92101-4495 SN 0022-2852 J9 J MOL SPECTROSC JI J. Mol. Spectrosc. PD JUL PY 1991 VL 148 IS 1 BP 114 EP 122 DI 10.1016/0022-2852(91)90040-H PG 9 WC Physics, Atomic, Molecular & Chemical; Spectroscopy SC Physics; Spectroscopy GA FR895 UT WOS:A1991FR89500012 ER PT J AU MUTH, LA AF MUTH, LA TI GENERAL ANALYTIC CORRECTION FOR PROBE-POSITION ERRORS IN SPHERICAL NEAR-FIELD MEASUREMENTS SO JOURNAL OF RESEARCH OF THE NATIONAL INSTITUTE OF STANDARDS AND TECHNOLOGY LA English DT Article DE COMPUTER SIMULATIONS; ERROR CORRECTION; SPHERICAL FAR FIELDS; SPHERICAL NEAR FIELDS AB A general theoretical procedure is presented to remove known probe-position errors in spherical near-field data to obtain highly accurate far fields. We represent the measured data as a Taylor series in terms of the displacement errors and the ideal spectrum of the antenna. This representation is then assumed to be an actual near field on a regularly spaced error-free spherical grid. The ideal spectrum is given by an infinite series of an error operator acting on data containing errors of measurement. This error operator is the Taylor series without the zeroth-order term. The n th-order approximation to the ideal near field of the antenna can be explicitly constructed by inspection of the error operator. Computer simulations using periodic error functions show that we are dealing with a convergent series, and the error-correction technique is highly successful. This is demonstrated for a triply periodic function for errors in each of the spherical coordinates. Appropriate graphical representations of the error-contaminated, error-corrected and error-free near fields are presented to enhance understanding of the results. Corresponding error-contaminated and error-free far fields are also obtained. RP MUTH, LA (reprint author), NATL INST STAND & TECHNOL, ELECTR & ELECT ENGN LAB, DIV ELECTROMAGNET FIELDS, ANTENMA METROL GRP, BOULDER, CO 80303 USA. NR 7 TC 2 Z9 2 U1 0 U2 0 PU US GOVERNMENT PRINTING OFFICE PI WASHINGTON PA SUPERINTENDENT DOCUMENTS,, WASHINGTON, DC 20402-9325 USA SN 1044-677X J9 J RES NATL INST STAN JI J. Res. Natl. Inst. Stand. Technol. PD JUL-AUG PY 1991 VL 96 IS 4 BP 391 EP 410 DI 10.6028/jres.096.021 PG 20 WC Instruments & Instrumentation; Physics, Applied SC Instruments & Instrumentation; Physics GA GG759 UT WOS:A1991GG75900001 PM 28184120 ER PT J AU PEACOCK, RD DAVIS, S BABRAUSKAS, V AF PEACOCK, RD DAVIS, S BABRAUSKAS, V TI DATA FOR ROOM FIRE MODEL COMPARISONS SO JOURNAL OF RESEARCH OF THE NATIONAL INSTITUTE OF STANDARDS AND TECHNOLOGY LA English DT Article DE ACCURACY ASSESSMENT; DATA ANALYSIS; EXPERIMENTS; FIRE MODELS; FIRE TESTS; INSTRUMENTS ID HEAT RELEASE RATE; OXYGEN-CONSUMPTION AB With the development of models to predict fire growth and spread in buildings, there has been a concomitant evolution in the measurement and analysis of experimental data in real-scale fires. This report presents the types of analyses that can be used to examine large-scale room fire test data to prepare the data for comparison with zone-based fire models. Five sets of experimental data which can be used to test the limits of a typical two-zone fire model are detailed. A standard set of nomenclature describing the geometry of the building and the quantities measured in each experiment is presented. Availability of ancillary data (such as smaller-scale test results) is included. These descriptions, along with the data (available in computer-readable form) should allow comparisons between the experiment and model predictions. The base of experimental data ranges in complexity from one room tests with individual furniture items to a series of tests conducted in a multiple story hotel equipped with a zoned smoke control system. RP PEACOCK, RD (reprint author), NATL INST STAND & TECHNOL, BLDG & FIRE RES LAB, DIV FIRE MEASUREMENT & RES, GAITHERSBURG, MD 20899 USA. NR 93 TC 11 Z9 12 U1 0 U2 1 PU US GOVERNMENT PRINTING OFFICE PI WASHINGTON PA SUPERINTENDENT DOCUMENTS,, WASHINGTON, DC 20402-9325 USA SN 1044-677X J9 J RES NATL INST STAN JI J. Res. Natl. Inst. Stand. Technol. PD JUL-AUG PY 1991 VL 96 IS 4 BP 411 EP 462 DI 10.6028/jres.096.022 PG 52 WC Instruments & Instrumentation; Physics, Applied SC Instruments & Instrumentation; Physics GA GG759 UT WOS:A1991GG75900002 PM 28184121 ER PT J AU GEIST, J CHANDLERHOROWITZ, D ROBINSON, AM JAMES, CR AF GEIST, J CHANDLERHOROWITZ, D ROBINSON, AM JAMES, CR TI NUMERICAL MODELING OF SILICON PHOTODIODES FOR HIGH-ACCURACY APPLICATIONS .1. SIMULATION PROGRAMS SO JOURNAL OF RESEARCH OF THE NATIONAL INSTITUTE OF STANDARDS AND TECHNOLOGY LA English DT Article DE HIGH ACCURACY; INTERNAL QUANTUM EFFICIENCY; PC-1D; PHOTODIODE MODELING; SILICON PHOTODIODES ID RESPONSE SELF-CALIBRATION; OPTICAL-PROPERTIES; QUANTUM YIELD; PHOTO-DIODES AB The suitability of the semiconductor-device modeling program PC-1D for high-accuracy simulation of silicon photodiodes is discussed. A set of user interface programs optimized to support high-accuracy batch-mode operation of PC-1D for modeling the internal quantum efficiency of photodiodes is also described. The optimization includes correction for the dark current under reverse- and forward-bias conditions before calculating the quantum efficiency, and easy access to the highest numerical accuracy available from PC-1D, neither of which is conveniently available with PC-1D's standard user interface. C1 UNIV ALBERTA, ELECT ENGN, EDMONTON T6G 2G7, ALBERTA, CANADA. RP GEIST, J (reprint author), NATL INST STAND & TECHNOL, DIV SEMICOND ELECTR, GAITHERSBURG, MD 20899 USA. RI Geist, Jon/D-5386-2013 NR 15 TC 9 Z9 9 U1 0 U2 1 PU US GOVERNMENT PRINTING OFFICE PI WASHINGTON PA SUPERINTENDENT DOCUMENTS,, WASHINGTON, DC 20402-9325 USA SN 1044-677X J9 J RES NATL INST STAN JI J. Res. Natl. Inst. Stand. Technol. PD JUL-AUG PY 1991 VL 96 IS 4 BP 463 EP 469 DI 10.6028/jres.096.023 PG 7 WC Instruments & Instrumentation; Physics, Applied SC Instruments & Instrumentation; Physics GA GG759 UT WOS:A1991GG75900003 PM 28184122 ER PT J AU GEIST, J KOHLER, R GOEBEL, R ROBINSON, AM JAMES, CR AF GEIST, J KOHLER, R GOEBEL, R ROBINSON, AM JAMES, CR TI NUMERICAL MODELING OF SILICON PHOTODIODES FOR HIGH-ACCURACY APPLICATIONS .2. INTERPRETING OXIDE-BIAS EXPERIMENTS SO JOURNAL OF RESEARCH OF THE NATIONAL INSTITUTE OF STANDARDS AND TECHNOLOGY LA English DT Article DE INDUCED JUNCTION PHOTODIODE; INVERSION LAYER PHOTODIODE; NUMERICAL MODELING; NUMERICAL SIMULATION; OXIDE-BIAS EXPERIMENT; QUANTUM EFFICIENCY ID RESPONSE SELF-CALIBRATION; QUANTUM EFFICIENCY; OPTICAL-PROPERTIES; NONLINEARITY; COLLECTION; DETECTOR; DIODES; YIELD AB The semiconductor device modeling program PC-1D and the programs that support its use in high-accuracy modeling of photodiodes, all of which were described in Part I of this series of papers, are used to simulate oxide-bias self-calibration experiments on three different types of silicon photodiodes. It is shown that these simulations can be used to determine photodiode characteristics, including the internal quantum efficiency for the different types of photodiodes. In the latter case, the simulations provide more accurate values than can be determined by using the conventional data reduction procedure, and an uncertainty estimate can be derived. Finally, it is shown that 0.9997 +/- 0.0003 is a nominal value for the internal quantum efficiency of one type of photodiode over the 440 to 460 nm spectral region. C1 BUR INT POIDS & MESURES, F-92310 SEVRES, FRANCE. UNIV ALBERTA, ELECT ENGN, EDMONTON T6G 2G7, ALBERTA, CANADA. RP GEIST, J (reprint author), NATL INST STAND & TECHNOL, DIV SEMICOND ELECTR, GAITHERSBURG, MD 20899 USA. RI Geist, Jon/D-5386-2013 NR 21 TC 2 Z9 2 U1 0 U2 2 PU US GOVERNMENT PRINTING OFFICE PI WASHINGTON PA SUPERINTENDENT DOCUMENTS,, WASHINGTON, DC 20402-9325 USA SN 1044-677X J9 J RES NATL INST STAN JI J. Res. Natl. Inst. Stand. Technol. PD JUL-AUG PY 1991 VL 96 IS 4 BP 471 EP 479 DI 10.6028/jres.096.024 PG 9 WC Instruments & Instrumentation; Physics, Applied SC Instruments & Instrumentation; Physics GA GG759 UT WOS:A1991GG75900004 PM 28184123 ER PT J AU GEIST, J ROBINSON, AM JAMES, CR AF GEIST, J ROBINSON, AM JAMES, CR TI NUMERICAL MODELING OF SILICON PHOTODIODES FOR HIGH-ACCURACY APPLICATIONS .3. INTERPOLATING AND EXTRAPOLATING INTERNAL QUANTUM-EFFICIENCY CALIBRATIONS SO JOURNAL OF RESEARCH OF THE NATIONAL INSTITUTE OF STANDARDS AND TECHNOLOGY LA English DT Article DE EXTRAPOLATION; INTERNAL QUANTUM-EFFICIENCY; INTERPOLATION; PHOTODIODE; SILICON; VISIBLE ID OPTICAL-PROPERTIES; TRANSISTORS; TEMPERATURE; LAYERS AB The semiconductor device modeling program PC-1D and the programs that support its use in high-accuracy modeling of photodiodes, all of which were described in Part I of this series of papers, are used to stimulate the interpolation of high-accuracy internal quantum-efficiency calibrations in the spectral region between 450 nm and 850 nm. Convenient interpolation formulae that depend only upon wave-length are derived. Uncertainty spectra for a number of sources of error are also derived. The formulae are normalized to experimental internal-quantum efficiency calibrations in the 440 to 470 nm spectral region and at 860 nm and are used to interpolate the calibration values between these wavelengths. The results of the interpolations are compared with experimental calibration data that are available at a few wave-lengths between 440 and 860 nm. The disagreement between the interpolated and measured internal quantum-efficiency data is never worse than 0.0003. C1 UNIV ALBERTA, ELECT ENGN, EDMONTON T6G 2G7, ALBERTA, CANADA. RP GEIST, J (reprint author), NATL INST STAND & TECHNOL, DIV SEMICOND ELECTR, GAITHERSBURG, MD 20899 USA. RI Geist, Jon/D-5386-2013 NR 20 TC 8 Z9 8 U1 0 U2 2 PU US GOVERNMENT PRINTING OFFICE PI WASHINGTON PA SUPERINTENDENT DOCUMENTS,, WASHINGTON, DC 20402-9325 USA SN 1044-677X J9 J RES NATL INST STAN JI J. Res. Natl. Inst. Stand. Technol. PD JUL-AUG PY 1991 VL 96 IS 4 BP 481 EP 492 DI 10.6028/jres.096.025 PG 12 WC Instruments & Instrumentation; Physics, Applied SC Instruments & Instrumentation; Physics GA GG759 UT WOS:A1991GG75900005 PM 28184124 ER PT J AU CRANMER, DC AF CRANMER, DC TI WORKSHOP ON ASSESSMENT OF TESTING METHODOLOGY FOR GLASS, GLASS-CERAMIC, AND CERAMIC MATRIX COMPOSITES - GAITHERSBURG, MD FEBRUARY 8, 1990 SO JOURNAL OF RESEARCH OF THE NATIONAL INSTITUTE OF STANDARDS AND TECHNOLOGY LA English DT Editorial Material AB A workshop on mechanical testing methodology for glass, glass-ceramic, and ceramic matrix composites was held at NIST on February 8, 1990. The purpose of the workshop was to assess room- and elevated-temperature measurement techniques for whisker- and continuous-fiber reinforced ceramic composites and their constituents. Techniques being used for metal- and polymer-matrix composites as well as those developed exclusively for use with ceramic composites were discussed. Important points included the use of tensile tests, not flexure, for strength and creep measurements; the need for different tests for material development and for system design; the need to precisely control test parameters; and the importance of specimen preparation. Additional conclusions were that the same tests used for monolithic ceramics can be used for whisker-reinforced materials with few or no changes, and that interlaboratory round robin tests were needed to determine both the reproducibility and limitations of the methodologies as well as material behavior. Additional research areas identified included long-term deformation behavior of composites, environmental effects on material behavior, and the relation of constituent properties to composite properties. RP CRANMER, DC (reprint author), NATL INST STAND & TECHNOL, DIV CERAM, GAITHERSBURG, MD 20899 USA. NR 16 TC 2 Z9 2 U1 0 U2 0 PU US GOVERNMENT PRINTING OFFICE PI WASHINGTON PA SUPERINTENDENT DOCUMENTS,, WASHINGTON, DC 20402-9325 USA SN 1044-677X J9 J RES NATL INST STAN JI J. Res. Natl. Inst. Stand. Technol. PD JUL-AUG PY 1991 VL 96 IS 4 BP 493 EP 501 DI 10.6028/jres.096.026 PG 9 WC Instruments & Instrumentation; Physics, Applied SC Instruments & Instrumentation; Physics GA GG759 UT WOS:A1991GG75900006 PM 28184125 ER PT J AU BUR, AJ HANDA, P GRUDZIEN, C AF BUR, AJ HANDA, P GRUDZIEN, C TI WORKSHOP ON NEW MEASUREMENT TECHNOLOGY FOR POLYMER PROCESSING - GAITHERSBURG, MD DECEMBER 3-4, 1990 SO JOURNAL OF RESEARCH OF THE NATIONAL INSTITUTE OF STANDARDS AND TECHNOLOGY LA English DT Editorial Material ID FLUORESCENCE AB This report describes activity at a workshop on New Measurement Technology for Polymer Processing which was held at the National Institute of Standards and Technology on December 3-4, 1990. The workshop was attended by 19 industry scientists and engineers from polymer processing and instrumentation manufacturing companies. The objective was to seek industry responses to the question: what in-line or on-line, real-time measurements do you need to make during polymer processing but are unable to do so because the measurement technology does not exist? Processors identified their measurement problems and needs by describing various processing operations. Tire and rubber manufacturing, thermoplastic compounding, injection molding, film processing, and reactive processing were described with respect to related measurement problems. Workshop discussions yielded a consensus of the following measurement needs: (a) in-line rheological measurements; (b) improved in-line temperature measurements; and, (c) in-line and on-line measurements of polymer morphology. An ongoing NIST measurement development program, which focuses on temperature and rheological measurements, was described. The NIST program is based on optical and fluorescence measurement techniques which have been used both for laboratory experiments and for instrumenting process machinery. The workshop is being used as a basis for developing NIST/industry collaboration on measurement technology development. C1 GOODYEAR TIRE & RUBBER CO, GOODYEAR RES, AKRON, OH 44305 USA. DYNISCO INC, SHARON, MA 02067 USA. RP BUR, AJ (reprint author), NATL INST STAND & TECHNOL, DIV POLYMERS, GAITHERSBURG, MD 20899 USA. NR 5 TC 0 Z9 0 U1 0 U2 1 PU US GOVERNMENT PRINTING OFFICE PI WASHINGTON PA SUPERINTENDENT DOCUMENTS,, WASHINGTON, DC 20402-9325 USA SN 1044-677X J9 J RES NATL INST STAN JI J. Res. Natl. Inst. Stand. Technol. PD JUL-AUG PY 1991 VL 96 IS 4 BP 503 EP 508 DI 10.6028/jres.096.027 PG 6 WC Instruments & Instrumentation; Physics, Applied SC Instruments & Instrumentation; Physics GA GG759 UT WOS:A1991GG75900007 PM 28184126 ER PT J AU TORARDI, CC PARISE, JB SANTORO, A RAWN, CJ ROTH, RS BURTON, BP AF TORARDI, CC PARISE, JB SANTORO, A RAWN, CJ ROTH, RS BURTON, BP TI SR2BI2O5 - A STRUCTURE CONTAINING ONLY 3-COORDINATED BISMUTH SO JOURNAL OF SOLID STATE CHEMISTRY LA English DT Article ID PHASE-EQUILIBRIA; SYSTEMS C1 SUNY STONY BROOK,INST MINERAL PHYS,STONY BROOK,NY 11794. SUNY STONY BROOK,DEPT EARTH & SPACE SCI,STONY BROOK,NY 11794. NATL INST STAND & TECHNOL,GAITHERSBURG,MD 20899. RP TORARDI, CC (reprint author), DUPONT CO,CENT RES,CENT RES & DEV,EXPTL STN,POB 80356,WILMINGTON,DE 19880, USA. NR 16 TC 19 Z9 19 U1 1 U2 6 PU ACADEMIC PRESS INC JNL-COMP SUBSCRIPTIONS PI SAN DIEGO PA 525 B ST, STE 1900, SAN DIEGO, CA 92101-4495 SN 0022-4596 J9 J SOLID STATE CHEM JI J. Solid State Chem. PD JUL PY 1991 VL 93 IS 1 BP 228 EP 235 DI 10.1016/0022-4596(91)90292-P PG 8 WC Chemistry, Inorganic & Nuclear; Chemistry, Physical SC Chemistry GA FV973 UT WOS:A1991FV97300026 ER PT J AU TOBLER, RL SHIMADA, M AF TOBLER, RL SHIMADA, M TI WARM PRECRACKING AT 295-K AND ITS EFFECTS ON THE 4-K TOUGHNESS OF AUSTENITIC STEELS SO JOURNAL OF TESTING AND EVALUATION LA English DT Article DE AUSTENITIC STAINLESS STEEL; CRYOGENIC PROPERTIES OF MATERIALS; FATIGUE; FRACTURE TOUGHNESS; TEST STANDARDS; WARM PRESTRESS ID FRACTURE-TOUGHNESS; FERRITIC STEELS; TEMPERATURE AB Experiments show that some austenitic steels at extreme cryogenic temperatures are toughened by warm prestress. We demonstrate this for Fe-17Cr-3Ni-13Mn-0.33N steel specimens that were warm precracked at 295 K and then fractured in liquid helium at 4 K where failure occurs by slip-plane cracking. On the other hand, Fe-13Cr-5Ni-22Mn-0.21N steel with higher toughness and a ductile fracture mechanism at 4 K was not affected by similar warm precracking. Austenitic and ferritic steel behaviors are compared, and precracking procedures for 4-K fracture tests are discussed. C1 KOBE STEEL LTD,CTR SUPERCOND & CRYOGEN TECHNOL,KOBE 651,JAPAN. RP TOBLER, RL (reprint author), NATL INST STAND & TECHNOL,DIV MAT RELIABIL,BOULDER,CO 80303, USA. NR 32 TC 4 Z9 4 U1 0 U2 0 PU AMER SOC TESTING MATERIALS PI W CONSHOHOCKEN PA 100 BARR HARBOR DR, W CONSHOHOCKEN, PA 19428-2959 SN 0090-3973 J9 J TEST EVAL JI J. Test. Eval. PD JUL PY 1991 VL 19 IS 4 BP 312 EP 320 PG 9 WC Materials Science, Characterization & Testing SC Materials Science GA FV053 UT WOS:A1991FV05300006 ER PT J AU PIERCE, TE WALDRUFF, PS AF PIERCE, TE WALDRUFF, PS TI PC-BEIS - A PERSONAL-COMPUTER VERSION OF THE BIOGENIC EMISSIONS INVENTORY SYSTEM SO JOURNAL OF THE AIR & WASTE MANAGEMENT ASSOCIATION LA English DT Article ID OZONE AB The U.S. Environmental Protection Agency's Biogenic Emissions Inventory System (BEIS) has been adapted for use on IBM-compatible personal computers (PCs). PC-BEIS estimates hourly emissions of isoprene, alpha-pinene, other monoterpenes, and unidentified hydrocarbons for any county in the contiguous United States. To run the program, users must provide hourly data on ambient temperature, relative humidity, wind speed, cloud cover, and a code that identifies the particular county. This paper provides an overview of the method used to calculate biogenic emissions, shows an example application, and gives information on how to obtain a copy of the program. C1 NOAA,RES TRIANGLE PK,NC. COMP SCI CORP,RES TRIANGLE PK,NC 27709. NR 17 TC 59 Z9 62 U1 2 U2 7 PU AIR & WASTE MANAGEMENT ASSOC PI PITTSBURGH PA PO BOX 2861, PITTSBURGH, PA 15230 SN 1047-3289 J9 J AIR WASTE MANAGE JI J. Air Waste Manage. Assoc. PD JUL PY 1991 VL 41 IS 7 BP 937 EP 941 PG 5 WC Engineering, Environmental; Environmental Sciences; Meteorology & Atmospheric Sciences SC Engineering; Environmental Sciences & Ecology; Meteorology & Atmospheric Sciences GA FY406 UT WOS:A1991FY40600013 ER PT J AU LONG, GG KRUEGER, S AF LONG, GG KRUEGER, S TI THE EFFECT OF GREEN DENSITY AND THE ROLE OF MAGNESIUM-OXIDE ADDITIVE ON THE DENSIFICATION OF ALUMINA MEASURED BY SMALL-ANGLE NEUTRON-SCATTERING SO JOURNAL OF THE AMERICAN CERAMIC SOCIETY LA English DT Article DE ALUMINA; MICROSTRUCTURE; SINTERING; CHARACTERIZATION; NEUTRONS ID MULTIPLE AB Small-angle neutron scattering measurements were used to examine the effect of green density and the role of MgO additive on the evolution of the porous microstructure of alumina during intermediate- and final-stage sintering. It was found that the initial connectivity in the green state plays a dominant role in establishing the channel diameters during the intermediate stage of sintering, and contributes also to determining the onset density at which the final stage of sintering begins. The role of MgO as a sintering aid lies, at least in part, in prolonging the stability of intermediate-stage sintering such that the body achieves greater density before the transition to final-stage sintering after which isolated pores are formed. C1 SW RES INST,SAN ANTONIO,TX 78228. RP LONG, GG (reprint author), NATL INST STAND & TECHNOL,GAITHERSBURG,MD 20899, USA. NR 14 TC 15 Z9 15 U1 0 U2 3 PU AMER CERAMIC SOC PI WESTERVILLE PA 735 CERAMIC PLACE, PO BOX 6136, WESTERVILLE, OH 43081-6136 SN 0002-7820 J9 J AM CERAM SOC JI J. Am. Ceram. Soc. PD JUL PY 1991 VL 74 IS 7 BP 1578 EP 1584 DI 10.1111/j.1151-2916.1991.tb07143.x PG 7 WC Materials Science, Ceramics SC Materials Science GA FX399 UT WOS:A1991FX39900012 ER PT J AU CHEN, CF WIEDERHORN, SM CHUANG, TJ AF CHEN, CF WIEDERHORN, SM CHUANG, TJ TI CAVITATION DAMAGE DURING FLEXURAL CREEP OF SIALON-YAG CERAMICS SO JOURNAL OF THE AMERICAN CERAMIC SOCIETY LA English DT Article DE CREEP; CAVITATION; SIALON; FLEXURE; HIGH TEMPERATURE ID SILICONIZED SILICON-CARBIDE; ENHANCED CREEP; DEFORMATION; TENSILE; PHASE AB Cavitation damage in flexure bars crept at 1170-degrees-C was studied by a density measurement technique. The cavity density within the flexure beams could be approximated by a linear function of position from the tensile surface. A threshold stress for cavitation damage is suggested from the results of this study. Below the threshold tensile stress, cavitation ceases, whereas above the threshold, cavitation damage is in the form of wedge-shaped cracks at grain-boundary triple junctions. Cavitation is not observed in compression for the conditions used in this study. From a stress analysis of the flexure bars, a cavitation threshold of 55 MPa is estimated for this material. C1 NATL INST STAND & TECHNOL,GAITHERSBURG,MD 20899. RP CHEN, CF (reprint author), UNIV MICHIGAN,DEPT MAT SCI & ENGN,ANN ARBOR,MI 48109, USA. NR 21 TC 15 Z9 16 U1 0 U2 2 PU AMER CERAMIC SOC PI WESTERVILLE PA 735 CERAMIC PLACE, PO BOX 6136, WESTERVILLE, OH 43081-6136 SN 0002-7820 J9 J AM CERAM SOC JI J. Am. Ceram. Soc. PD JUL PY 1991 VL 74 IS 7 BP 1658 EP 1662 DI 10.1111/j.1151-2916.1991.tb07156.x PG 5 WC Materials Science, Ceramics SC Materials Science GA FX399 UT WOS:A1991FX39900025 ER PT J AU WAGNER, C AF WAGNER, C TI A PROGRADE GEOSAT EXACT REPEAT MISSION SO JOURNAL OF THE ASTRONAUTICAL SCIENCES LA English DT Article AB Prograde/retrograde orbit pairs that yield close ground tracks at low latitudes are cited for Exact Repeat Missions (ERM). In particular, the prograde orbit which most closely matches the Geosat ERM (108-degrees inclination) is found to have an inclination of 65.1-degrees. This orbit can stay within +/- 10 km of the Geosat ERM ground track to +/- 28-degrees latitude. The objective is to duplicate this well-covered retrograde track as much as possible, thereby maximizing its oceanographic use in the event another retrograde mission will not be possible. A prograde Geosat ERM can support a heavier satellite and allow the P1 tide to be determined from collinear altimetry, as compared to the current mission which tracks to somewhat higher latitudes and on which the P1 tide is stationary. RP WAGNER, C (reprint author), NOAA,NATL GEODET SURVEY,CHARTING & GEODET SERV,ROCKVILLE,MD 20852, USA. NR 4 TC 4 Z9 4 U1 0 U2 0 PU AMER ASTRONAUTICAL SOC PI SPRINGFIELD PA 6352 ROLLING MILL PLACE SUITE 102, SPRINGFIELD, VA 22152 SN 0021-9142 J9 J ASTRONAUT SCI JI J. Astronaut. Sci. PD JUL-SEP PY 1991 VL 39 IS 3 BP 313 EP 326 PG 14 WC Engineering, Aerospace SC Engineering GA GB885 UT WOS:A1991GB88500004 ER PT J AU WOICIK, JC BOULDIN, CE CROSS, JO SORENSEN, LB KING, CA AF WOICIK, JC BOULDIN, CE CROSS, JO SORENSEN, LB KING, CA TI EXTENDED X-RAY ABSORPTION FINE-STRUCTURE AND X-RAY-DIFFRACTION STUDY OF STRAIN AND BOND DISTORTIONS IN EPITAXIAL SEMICONDUCTOR LAYERS SO JOURNAL OF VACUUM SCIENCE & TECHNOLOGY B LA English DT Article ID HETEROJUNCTION BIPOLAR-TRANSISTORS; ALLOYS AB Extended x-ray absorption fine structure and x-ray diffraction have determined the strain and bond distortions in epitaxial Ge(x)Si1-x on Si(001). In a 31% Ge, 340 angstrom pseudomorphic Ge(x)Si1-x film, the Ge-Ge and Ge-Si first-neighbor bond lengths have been found to be 2.44 +/- 0.02 and 2.38 +/- 0.02 angstrom, respectively. The lattice parameter perpendicular to the Ge(x)Si1-x/Si(001) interface has been found to be a perpendicular-to = 5.553 +/- 0.002 angstrom. These results show that the bond length strain in epitaxial semiconductor layers appears primarily in the second and higher coordination shells, rather than in the nearest-neighbor bond lengths which remain the same as in the unstrained materials. A microscopic model is presented which accounts for these findings. C1 UNIV WASHINGTON,DEPT PHYS,SEATTLE,WA 98195. AT&T BELL LABS,MURRAY HILL,NJ 07974. RP WOICIK, JC (reprint author), NATL INST STAND & TECHNOL,GAITHERSBURG,MD 20899, USA. NR 11 TC 7 Z9 7 U1 0 U2 1 PU AMER INST PHYSICS PI WOODBURY PA CIRCULATION FULFILLMENT DIV, 500 SUNNYSIDE BLVD, WOODBURY, NY 11797-2999 SN 1071-1023 J9 J VAC SCI TECHNOL B JI J. Vac. Sci. Technol. B PD JUL-AUG PY 1991 VL 9 IS 4 BP 2194 EP 2197 DI 10.1116/1.585763 PG 4 WC Engineering, Electrical & Electronic; Nanoscience & Nanotechnology; Physics, Applied SC Engineering; Science & Technology - Other Topics; Physics GA GB897 UT WOS:A1991GB89700050 ER PT J AU KENDELEWICZ, T WOICIK, JC MIYANO, KE COWAN, PL KARLIN, BA BOULDIN, CE PIANETTA, P SPICER, WE AF KENDELEWICZ, T WOICIK, JC MIYANO, KE COWAN, PL KARLIN, BA BOULDIN, CE PIANETTA, P SPICER, WE TI SYNCHROTRON X-RAY STANDING-WAVE STUDY OF SB ON GAAS(110) AND INP(110) SO JOURNAL OF VACUUM SCIENCE & TECHNOLOGY B LA English DT Article ID ENERGY ELECTRON-DIFFRACTION; SURFACE REGISTRATION PROBLEM; RADIATION BEAMLINE; 110 SURFACES; ANTIMONY; SEMICONDUCTORS; OVERLAYERS; RESOLUTION AB The soft x-ray standing-wave technique has been used to study ordered monolayers of Sb on GaAs(110) and InP(110). Using the back-reflection diffraction geometry from (220) planes, we determine the perpendicular distances of Sb atoms to the substrate and compare these with theoretical calculations and elastic low-energy electron diffraction determinations. The various models of Sb chemisorption are evaluated on the basis of our data. C1 NATL INST STAND & TECHNOL,GAITHERSBURG,MD 20899. BROOKHAVEN NATL LAB,NATL SYNCHROTRON RADIAT LIGHT SOURCE,UPTON,NY 11973. RP KENDELEWICZ, T (reprint author), STANFORD UNIV,STANFORD ELECTR LABS,STANFORD,CA 94305, USA. NR 22 TC 13 Z9 13 U1 1 U2 1 PU AMER INST PHYSICS PI WOODBURY PA CIRCULATION FULFILLMENT DIV, 500 SUNNYSIDE BLVD, WOODBURY, NY 11797-2999 SN 1071-1023 J9 J VAC SCI TECHNOL B JI J. Vac. Sci. Technol. B PD JUL-AUG PY 1991 VL 9 IS 4 BP 2290 EP 2293 DI 10.1116/1.585735 PG 4 WC Engineering, Electrical & Electronic; Nanoscience & Nanotechnology; Physics, Applied SC Engineering; Science & Technology - Other Topics; Physics GA GB897 UT WOS:A1991GB89700066 ER PT J AU STILES, MD HAMANN, DR AF STILES, MD HAMANN, DR TI KINEMATIC THEORY OF BALLISTIC ELECTRON-EMISSION SPECTROSCOPY OF SILICON-SILICIDE INTERFACES SO JOURNAL OF VACUUM SCIENCE & TECHNOLOGY B LA English DT Article ID NISI2-SI(111) INTERFACE; ATOMIC-STRUCTURE; BAND-STRUCTURE; MICROSCOPY AB The electronic structure of the materials being measured has a strong effect on the spectroscopy of the interface between them measured by ballistic electron emission microscopy (BEEM). Specific calculations for CoSi2/Si(111) and NiSi2/Si(111) based on the calculation band structures of the materials illustrate some of the observable effects due to band structures, particularly of the overlayer. The BEEM spectra for CoSi2/Si(111) show a delayed onset due to a mismatch of the states near the conduction band minimum in the Si. The spectra for NiSi2/Si(111) show structure due to a decrease in the density of states in the NiSi2 at approximately 1.8 eV above the Fermi level. C1 AT&T BELL LABS,MURRAY HILL,NJ 07974. RP STILES, MD (reprint author), NATL INST STAND & TECHNOL,GAITHERSBURG,MD 20899, USA. RI Stiles, Mark/K-2426-2012 OI Stiles, Mark/0000-0001-8238-4156 NR 26 TC 43 Z9 43 U1 0 U2 1 PU AMER INST PHYSICS PI WOODBURY PA CIRCULATION FULFILLMENT DIV, 500 SUNNYSIDE BLVD, WOODBURY, NY 11797-2999 SN 1071-1023 J9 J VAC SCI TECHNOL B JI J. Vac. Sci. Technol. B PD JUL-AUG PY 1991 VL 9 IS 4 BP 2394 EP 2398 DI 10.1116/1.585709 PG 5 WC Engineering, Electrical & Electronic; Nanoscience & Nanotechnology; Physics, Applied SC Engineering; Science & Technology - Other Topics; Physics GA GB897 UT WOS:A1991GB89700084 ER PT J AU TESTER, PA STUMPF, RP VUKOVICH, FM FOWLER, PK TURNER, JT AF TESTER, PA STUMPF, RP VUKOVICH, FM FOWLER, PK TURNER, JT TI AN EXPATRIATE RED TIDE BLOOM - TRANSPORT, DISTRIBUTION, AND PERSISTENCE SO LIMNOLOGY AND OCEANOGRAPHY LA English DT Note ID GYMNODINIUM-BREVE; CAROLINA; WINTER AB In November 1987, the toxic dinoflagellate Gymnodinium breve bloomed in North Carolina nearshore waters. This occurrence was the first record of G. breve north of Florida, a range extension of > 800 km. We propose the (Gulf of Mexico) Loop Current-Florida Current-Gulf Stream system as the transport mechanism for G. breve cells from a late summer bloom off the southwest coast of Florida (Charlotte Harbor-Sarasota). The estimated transit time for cells around the peninsula and northward to the continental shelf off North Carolina is 22-54 d. About 30 d after the Charlotte Harbor-Sarasota bloom, satellite images of sea-surface temperature substantiated the shoreward movement of a filament of Gulf Stream water onto the narrow continental shelf between Cape Hatteras and Cape Lookout. This filament, the likely source of G. breve cells, remained in nearshore waters and was identifiable in satellite images for > 19 d. Once the bloom was inshore, both windspeed and direction were important in determining its distribution. C1 NOAA,NATL ENVIRONM SATELLITE DATA & INFORMAT SERV,OFF RES & APPLICAT,SUITLAND,MD 20746. RES TRIANGLE INST,RES TRIANGLE PK,NC 27709. N CAROLINA DEPT ENVIRONM HLTH & NAT RESOURCES,SHELLFISH SANITAT BRANCH,MOREHEAD CITY,NC 28557. SE MASSACHUSETTS UNIV,DEPT BIOL,N DARTMOUTH,MA 02747. RP TESTER, PA (reprint author), NOAA,NATL MARINE FISHERIES SERV,SE FISHERIES CTR,BEAUFORT LAB,BEAUFORT,NC 28516, USA. NR 28 TC 100 Z9 103 U1 0 U2 5 PU AMER SOC LIMNOLOGY OCEANOGRAPH PI LAWRENCE PA 810 EAST 10TH ST, LAWRENCE, KS 66044-8897 SN 0024-3590 J9 LIMNOL OCEANOGR JI Limnol. Oceanogr. PD JUL PY 1991 VL 36 IS 5 BP 1053 EP 1061 PG 9 WC Limnology; Oceanography SC Marine & Freshwater Biology; Oceanography GA GP594 UT WOS:A1991GP59400021 ER PT J AU DOMICH, PD BOGGS, PT ROGERS, JE WITZGALL, C AF DOMICH, PD BOGGS, PT ROGERS, JE WITZGALL, C TI OPTIMIZING OVER 3-DIMENSIONAL SUBSPACES IN AN INTERIOR-POINT METHOD FOR LINEAR-PROGRAMMING SO LINEAR ALGEBRA AND ITS APPLICATIONS LA English DT Article ID POLYNOMIAL-TIME ALGORITHM AB Interior-point algorithms for solving linear programming problems are considered. A three-dimensional method is developed that, at each iteration, solves a subproblem based on minimizing the cost function on low-dimensional cross sections of the feasible region. The generators for the three-dimensional subproblem include the dual affine search direction and two higher-order search directions. One of the higher-order directions is a third-order correction to the Newton recentering direction, and the other is a correction to the dual affine direction that is motivated by the use of rank-one updates of the second-derivative information. Numerical results are presented for this method that indicate a nearly 20% reduction in CPU time compared to our best dual affine implementation. C1 NATL INST STAND & TECHNOL,DIV APPL & COMPUTAT MATH,GAITHERSBURG,MD 20899. RP DOMICH, PD (reprint author), NATL INST STAND & TECHNOL,DIV APPL & COMPUTAT MATH,BOULDER,CO 80303, USA. NR 33 TC 0 Z9 0 U1 0 U2 0 PU ELSEVIER SCIENCE INC PI NEW YORK PA 655 AVENUE OF THE AMERICAS, NEW YORK, NY 10010 SN 0024-3795 J9 LINEAR ALGEBRA APPL JI Linear Alg. Appl. PD JUL PY 1991 VL 152 BP 315 EP 342 DI 10.1016/0024-3795(91)90280-A PG 28 WC Mathematics, Applied; Mathematics SC Mathematics GA FN904 UT WOS:A1991FN90400018 ER PT J AU AU, WWL JONES, L AF AU, WWL JONES, L TI ACOUSTIC REFLECTIVITY OF NETS - IMPLICATIONS CONCERNING INCIDENTAL TAKE OF DOLPHINS SO MARINE MAMMAL SCIENCE LA English DT Article DE ACOUSTIC REFLECTIVITY OF NETS; INCIDENTAL TAKE OF DOLPHINS BY GILLNETS; DOLPHIN SONAR DETECTION OF NETS ID ECHOLOCATION SIGNALS AB Sonar target strength measurements of several types of nets and associated gear were made using simulated dolphin echolocation signals. The different types of nets included (a) standard commercial monofilament gillnet used in the salmon mothership fishery, (b) prototype hollow core monofilament net, (c) Macah tribal cord setnet, and (d) multifilament nets. Target strength measurements were made at four angles of incidence, 0-degrees (normal to net), 15-degrees, 30-degrees, and 45-degrees. The standard gillnet had the smallest target strength which was relatively independent of the angle of incidence. The target strength based on the peak-to-peak values of the echoes varied from -59 to -62 dB. Using echo energy within the integration time of Tursiops truncatus, the target strength was found to be between -54 and -59 dB. Biosonar detection ranges for different sea state conditions were estimated using the noise-limited form of the sonar equation and target detection data obtained for Tursiops truncatus in Kaneohe Bay, Oahu, Hawaii. The results suggest that an echolocating dolphin should be able to detect a gillnet at ranges long enough to avoid entanglement, even in sea state 6 conditions. Several possibilities for the seeming inability of dolphins to detect gillnets are discussed. C1 NATL MARINE MAMMAL LAB,SEATTLE,WA. RP AU, WWL (reprint author), USN,CTR OCEAN SYST,KAILUA,HI 96734, USA. NR 34 TC 22 Z9 22 U1 0 U2 7 PU SOC MARINE MAMMALOGY PI LAWRENCE PA 1041 NEW HAMPSHIRE ST, LAWRENCE, KS 66044 SN 0824-0469 J9 MAR MAMMAL SCI JI Mar. Mamm. Sci. PD JUL PY 1991 VL 7 IS 3 BP 258 EP 273 DI 10.1111/j.1748-7692.1991.tb00101.x PG 16 WC Marine & Freshwater Biology; Zoology SC Marine & Freshwater Biology; Zoology GA GB740 UT WOS:A1991GB74000003 ER PT J AU LAWRENCE, J AF LAWRENCE, J TI POLYTOPE VOLUME COMPUTATION SO MATHEMATICS OF COMPUTATION LA English DT Article ID INTEGRAL PROPERTIES; COMPLEXITY; ALGORITHM; ENUMERATION; POLYHEDRON; SOLIDS AB A combinatorial form of Gram's relation for convex polytopes can be adapted for use in computing polytope volume. We present an algorithm for volume computation based on this observation. This algorithm is useful in finding the volume of a polytope given as the solution set of a system of linear inequalities, P = {x element-of R(n):Ax less-than-or-equal-to b}. As an illustration we compute a formula for the volume of a projective image of the n-cube. From this formula we deduce that, when A and b have rational entries (so that the volume of P is also a rational number), the number of binary digits in the denominator of the volume cannot be bounded by a polynomial in the total number of digits in the numerators and denominators of entries of A and b. This settles a question posed by Dyer and Frieze. C1 NATL INST STAND & TECHNOL,CTR COMP & APPL MATH,GAITHERSBURG,MD 20899. RP LAWRENCE, J (reprint author), GEORGE MASON UNIV,DEPT MATH SCI,FAIRFAX,VA 22030, USA. NR 30 TC 61 Z9 61 U1 0 U2 3 PU AMER MATHEMATICAL SOC PI PROVIDENCE PA 201 CHARLES ST, PROVIDENCE, RI 02940-2213 SN 0025-5718 J9 MATH COMPUT JI Math. Comput. PD JUL PY 1991 VL 57 IS 195 BP 259 EP 271 DI 10.2307/2938672 PG 13 WC Mathematics, Applied SC Mathematics GA FZ449 UT WOS:A1991FZ44900013 ER PT J AU MUENCH, PJ MEIGOONI, AS NATH, R MCLAUGHLIN, WL AF MUENCH, PJ MEIGOONI, AS NATH, R MCLAUGHLIN, WL TI PHOTON ENERGY-DEPENDENCE OF THE SENSITIVITY OF RADIOCHROMIC FILM AND COMPARISON WITH SILVER-HALIDE FILM AND LIF TLDS USED FOR BRACHYTHERAPY DOSIMETRY SO MEDICAL PHYSICS LA English DT Article DE RADIOCHROMIC FILM; BRACHYTHERAPY; DOSE-DISTRIBUTION MAPPING; ENERGY DEPENDENCE; DOSIMETRY AB There is a new radiochromic film, a highly uniform, thin (100-mu-m) detector whose sensitive layer (6-mu-m thick) changes from colorless to blue by dye polymerization without processing, upon exposure to ionizing radiation. Because the dose gradients around brachytherapy sources are steep, the high spatial resolution offered by film dosimetry is an advantage over other detectors such as thermoluminescent dosimeters (TLDs). This compares the photon energy dependence of the sensitivities of GafChromic film, silver halide verification film (Kodak X-Omat V Film), and lithium fluoride TLDs (Harshaw), over the photon energy range 28 keV to 1.7 MeV, which is of interest in brachytherapy. Sensitivity of the radiochromic film is observed to decrease by about 30% as effective photon energy decreases from 1710 keV (4-MV x rays) to 28 keV (60-kV x rays, 2-mm Al filter). In contrast, the sensitivity of verification film increases by 980% and that of LiF TLDs increases by 41%. The variation of the sensitivity of radiochromic film with photon energy is considerably less than that for silver halide film and similar to that for LiF TLDs, but in the opposite direction. Radiochromic film, like LIF TLDs, does not exhibit the drastic sensitivity changes below 127 keV that silver halide film exhibits. Dose distribution in the immediate vicinity of a high activity (370 GBq) brachytherapy Ir-192 source has been mapped using radiochromic film and is presented to illustrate the applicability of this new technology to brachytherapy dosimetry. C1 NATL INST STAND & TECHNOL,CTR RADIAT RES,GAITHERSBURG,MD 20899. RP MUENCH, PJ (reprint author), YALE UNIV,SCH MED,DEPT THERAPEUT RADIOL,333 CEDAR ST,NEW HAVEN,CT 06510, USA. FU NCI NIH HHS [CA-39044, CA-49469] NR 11 TC 148 Z9 148 U1 1 U2 7 PU AMER INST PHYSICS PI WOODBURY PA CIRCULATION FULFILLMENT DIV, 500 SUNNYSIDE BLVD, WOODBURY, NY 11797-2999 SN 0094-2405 J9 MED PHYS JI Med. Phys. PD JUL-AUG PY 1991 VL 18 IS 4 BP 769 EP 775 DI 10.1118/1.596630 PG 7 WC Radiology, Nuclear Medicine & Medical Imaging SC Radiology, Nuclear Medicine & Medical Imaging GA GB235 UT WOS:A1991GB23500015 PM 1921886 ER PT J AU SOARES, CG AF SOARES, CG TI CALIBRATION OF OPHTHALMIC APPLICATORS AT NIST - A REVISED APPROACH SO MEDICAL PHYSICS LA English DT Article AB A revised approach to the problem of measuring a surface-absorbed dose from beta-particle-emitting ophthalmic applicators is presented. The technique chosen employs an extrapolation chamber equipped with a 4-mm-diam collecting electrode to make current measurements at air gaps from 0.08 to 0.20 mm at 0.02-mm intervals. These data yield a linear relationship between current and air gap, the slope of which is used to determine average surface-absorbed-dose rate over the central area of the source. For additional information about the distribution of the activity over the source surface, autoradiographs using calibrated radiochromic dye films are analyzed to map the dose-rate profile across the surface of the applicator. Experiments varying several parameters of the extrapolation chamber measurement, including collecting electrode area, voltage gradient, range of air gaps used, and entrance foil material, are described. Also treated are calibrations of, and a description of the use of, radiochromic dye films for source profiling. Experiments for determining correction factors for the extrapolation chamber measurements are described, and an assessment of the uncertainties associated with these measurements is given. RP SOARES, CG (reprint author), NATL INST STAND & TECHNOL,GAITHERSBURG,MD 20899, USA. RI Grams, Michael/G-5197-2011 NR 18 TC 51 Z9 51 U1 0 U2 2 PU AMER INST PHYSICS PI WOODBURY PA CIRCULATION FULFILLMENT DIV, 500 SUNNYSIDE BLVD, WOODBURY, NY 11797-2999 SN 0094-2405 J9 MED PHYS JI Med. Phys. PD JUL-AUG PY 1991 VL 18 IS 4 BP 787 EP 793 DI 10.1118/1.596632 PG 7 WC Radiology, Nuclear Medicine & Medical Imaging SC Radiology, Nuclear Medicine & Medical Imaging GA GB235 UT WOS:A1991GB23500017 PM 1921888 ER PT J AU MO, KC ZIMMERMAN, JR KALNAY, E KANAMITSU, M AF MO, KC ZIMMERMAN, JR KALNAY, E KANAMITSU, M TI A GCM STUDY OF THE 1988 UNITED-STATES DROUGHT SO MONTHLY WEATHER REVIEW LA English DT Article AB June 1988 has been classified as one of the hottest and driest months on record in the United States. This study used the NMC Medium-Range Forecast (MRF) T40 model to simulate circulation features of June 1988 and to investigate the relationship between sea surface temperature anomalies (SSTA) and circulation patterns in the Northern Hemisphere. Three control experiments have been performed using three different initial conditions, separated by one day (21, 22, and 23 May 1988) and using SSTA fixed at the starting date. The three forecasts, and their average, are remarkably skillful in the Northern Hemisphere. The observed anomaly of June 1988, a wave train with a persistent ridge in the north-central United States and a northward shifting of the jet stream in the Pacific-North America area, is very well simulated in each of the integrations. All three experiments were repeated using the same initial conditions, but with climatological SST. The wave train generated is similar to that in the control experiments, but it is not as robust. The simulated jet streams are also similar to those in the control experiments. Two experiments with the 1988 SSTA, but with initial conditions of 22 May 1987 and 22 May 1989 were also run. The circulation patterns generated by these runs are very different from those of 1988, indicating that the persistence of the anomalous ridge in the north-central United States after late May 1988 was not due to the SSTA of the May 1988 alone. A barotropic analysis was done to obtain the normal modes associated with the 300-mb streamfunction of the June climatology. The analysis indicates the existence of a slowly growing mode with structure similar to the anomalies of 1988. This result, as well as the numerical experiments, suggests that the persistence of the June 1988 wave train may be associated with initial conditions, which were in a rather stable regime. The SSTA may have helped to strengthen the pattern, but the wave train associated with the 1988 drought could not have been generated by SSTA alone. C1 NOAA,NATL WEATHER SERV,NATL METEOROL CTR,DIV DEV,WASHINGTON,DC 20233. RP MO, KC (reprint author), NOAA,NATL WEATHER SERV,NATL METEOROL CTR,W-NMC52,WASHINGTON,DC 20233, USA. RI Kalnay, Eugenia/F-4393-2010 NR 19 TC 39 Z9 39 U1 0 U2 1 PU AMER METEOROLOGICAL SOC PI BOSTON PA 45 BEACON ST, BOSTON, MA 02108-3693 SN 0027-0644 J9 MON WEATHER REV JI Mon. Weather Rev. PD JUL PY 1991 VL 119 IS 7 BP 1512 EP 1532 DI 10.1175/1520-0493(1991)119<1512:AGSOTU>2.0.CO;2 PG 21 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA FX881 UT WOS:A1991FX88100002 ER PT J AU KEIGHTON, SJ BLUESTEIN, HB MACGORMAN, DR AF KEIGHTON, SJ BLUESTEIN, HB MACGORMAN, DR TI THE EVOLUTION OF A SEVERE MESOSCALE CONVECTIVE SYSTEM - CLOUD-TO-GROUND LIGHTNING LOCATION AND STORM STRUCTURE SO MONTHLY WEATHER REVIEW LA English DT Article ID 10-11 JUNE 1985; DOPPLER RADAR; SQUALL LINES; CHARGE SEPARATION; LIFE-CYCLE; PRECIPITATION; THUNDERSTORMS; OKLAHOMA; ELECTRIFICATION; THUNDERCLOUDS AB Cloud-to-ground lightning-location data are correlated with the Doppler-radar-observed structure of the evolution of a severe mesoscale convective system in Oklahoma on 23 May 1981. While many of the results are not new, this study is unique in that the evolution of electrical activity in a severe storm is compared to storm structure for most of the storm's life. The first storm formed ahead of a mesoscale low pressure area located at the intersection of a front and a dryline, and developed into a tornadic supercell in an environment of locally enhanced vertical shear. Ordinary cells subsequently formed both to the southwest and northeast of the supercell along the dryline and the front, respectively, and merged with the supercell to form a squall line having a trailing stratiform precipitation region with midlevel rear inflow. It is shown that the cloud-to-ground flash rate in the convective region is related to the apparent strength of the updraft. Before the storm became a supercell, the lightning strikes, which were relatively infrequent, emanated from the anvil west of the core. When the supercell was producing its first tornado, most lightning strikes occurred around the edge of the most intense core and under the anvil south of the core. As the supercell weakened, ground strikes clustered closer to the core. During the squall-line stage, most cloud-to-ground lightning strikes were found to the rear of the core of the remnants of the supercell, and in the core of the cells to the southwest, which were less mature. The overall ground-strike rate peaked during the middle portion of the squall-line phase. The area of the midlevel radar echo associated with the most intense reflectivity core was well correlated with the ground strike rate. The area of midlevel radar echo representing the weaker portion of the core, however, lagged the ground-strike rate. C1 UNIV OKLAHOMA,SCH METEOROL,NORMAN,OK 73019. NATL SEVERE STORMS LAB,NORMAN,OK 73069. NR 55 TC 31 Z9 36 U1 2 U2 3 PU AMER METEOROLOGICAL SOC PI BOSTON PA 45 BEACON ST, BOSTON, MA 02108-3693 SN 0027-0644 J9 MON WEATHER REV JI Mon. Weather Rev. PD JUL PY 1991 VL 119 IS 7 BP 1533 EP 1556 DI 10.1175/1520-0493(1991)119<1533:TEOASM>2.0.CO;2 PG 24 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA FX881 UT WOS:A1991FX88100003 ER PT J AU MACGORMAN, DR NIELSEN, KE AF MACGORMAN, DR NIELSEN, KE TI CLOUD-TO-GROUND LIGHTNING IN A TORNADIC STORM ON 8 MAY 1986 SO MONTHLY WEATHER REVIEW LA English DT Article ID ELECTRIC-FIELD MEASUREMENTS; DOPPLER RADAR; THUNDERSTORM ANVIL; MESOSCALE STORM; ELECTRIFICATION; PRECIPITATION; SYSTEMS; GENERATION; VORTICITY; SHEAR AB On 8 May 1986, the National Severe Storms Laboratory (NSSL) collected Doppler radar and lightning ground strike data on a supercell storm that produced three tornadoes, including an F3 tornado in Edmond, Oklahoma, approximately 40 km north of NSSL. The Edmond storm formed 30 km ahead of a storm complex and produced its first and most damaging tornado just as the storm complex began to overtake it from the west. In the mesocyclone that spawned the tornado, low-level cyclonic shear peaked as the first tornado dissipated and a second tornado began. As low-level cyclonic shear initially increased, negative cloud-to-ground lightning flash rates also increased, reaching a peak of 11 min-1 a few minutes after the peak in cyclonic shear. During this period lightning strike locations tended to concentrate just north of the mesocyclone, near and inside a 50-dBZ reflectivity core. As cyclonic shear decreased from its peak during and after the second tornado, negative ground flash rates also decreased, and strike locations became more scattered. Positive ground flashes began just before the storm became tornadic, and positive flash rates peaked during the tornadic stage of the storm. The evolution of cloud-to-ground lightning in the Edmond storm differed considerably from the evolution of lightning in the Binger tornadic storm of 22 May 1981 that was studied previously. In the Binger storm, ground flash rates were negatively correlated with cyclonic shear and peaked 15-20 min later than low-level shear and intracloud lightning. It is suggested that the very strong mesocyclone and updraft in the Binger storm enhanced intracloud flash production and delayed ground flashes by causing the initial height of negative charge to be higher than in most storms. It is also suggested that weaker updrafts and a weaker, shallower mesocyclone in the Edmond storm resulted in higher negative ground flash rates when the Edmond mesocyclone was still strong, because negative charge near the mesocyclone was at the lower heights common to most thunderstorms. C1 NOAA,ENVIRONM RES LAB,NATL SEVERE STORMS LAB,COOPERAT INST MESOSCALE METEOROL STUDIES,NORMAN,OK 73069. RP MACGORMAN, DR (reprint author), NOAA,ENVIRONM RES LAB,NATL SEVERE STORMS LAB,1313 HALLEY CIRCLE,NORMAN,OK 73069, USA. OI MacGorman, Donald/0000-0002-2395-8196 NR 68 TC 51 Z9 53 U1 0 U2 3 PU AMER METEOROLOGICAL SOC PI BOSTON PA 45 BEACON ST, BOSTON, MA 02108-3693 SN 0027-0644 J9 MON WEATHER REV JI Mon. Weather Rev. PD JUL PY 1991 VL 119 IS 7 BP 1557 EP 1574 DI 10.1175/1520-0493(1991)119<1557:CTGLIA>2.0.CO;2 PG 18 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA FX881 UT WOS:A1991FX88100004 ER PT J AU AUGUSTINE, JA HOWARD, KW AF AUGUSTINE, JA HOWARD, KW TI MESOSCALE CONVECTIVE COMPLEXES OVER THE UNITED-STATES DURING 1986 AND 1987 SO MONTHLY WEATHER REVIEW LA English DT Article ID WEATHER SYSTEMS; PRECIPITATION; METEOROLOGY; PLATEAU; FLOOD AB Infrared imagery from GOES was used to document mesoscale convective complexes (MCCs) over the United States during 1986 and 1987. A near-record 58 MCCs occurred in 1986, and 44 occurred in 1987. Although these totals were above average relative to MCC numbers of the 7 years prior to 1985, seasonal distributions for both years were atypical. Particularly, each had an extended period (approximately 3 weeks) when no MCCs occurred in late spring and early summer, a time when the mean MCC seasonal distribution peaks. This peculiarity was investigated by comparing mean large-scale surface and upper-air environments of null- and active-MCC periods of both years. Results confirmed the primary importance to MCC development of strong low-level thermal forcing, as well as proper vertical phasing of favorable lower- and midtropospheric environments. A cursory survey of MCCs documented outside of the United States reveals that MCCs, or MCC-type storms, are a warm-season phenomenon of midlatitude, subtropical, and low-latitude regions around the globe. They have been documented in South America, Mexico, Europe, West Africa, and China. These storm systems are similar to United States MCCs in that they are nocturnal, persist for over 10 h, tend to develop within weak synoptic-scale dynamics in response to strong low-level thermal forcing and conditional instability, and occur typically downwind (midlevel) of elevated terrain. It is surmised that MCCs probably occur over other parts of the midlatitudes, subtropics, and low latitudes that have yet to be surveyed. RP AUGUSTINE, JA (reprint author), NOAA,NATL SEVERE STORMS LAB,DIV MESOSCALE RES,R-E-NSI,325 BROADWAY,BOULDER,CO 80303, USA. NR 28 TC 66 Z9 99 U1 0 U2 5 PU AMER METEOROLOGICAL SOC PI BOSTON PA 45 BEACON ST, BOSTON, MA 02108-3693 SN 0027-0644 J9 MON WEATHER REV JI Mon. Weather Rev. PD JUL PY 1991 VL 119 IS 7 BP 1575 EP 1589 DI 10.1175/1520-0493(1991)119<1575:MCCOTU>2.0.CO;2 PG 15 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA FX881 UT WOS:A1991FX88100005 ER PT J AU MURPHY, AH AF MURPHY, AH TI FORECAST VERIFICATION - ITS COMPLEXITY AND DIMENSIONALITY SO MONTHLY WEATHER REVIEW LA English DT Article AB Two fundamental characteristics of forecast verification problems-complexity and dimensionality-are described. To develop quantitative definitions of these characteristics, a general framework for the problem of absolute verification (AV) is extended to the problem of comparative verification (CV). Absolute verification focuses on the performance of individual forecasting systems (or forecasters), and it is based on the bivariate distribution of forecasts and observations and its two possible factorizations into conditional and marginal distributions. Comparative verification compares the performance of two or more forecasting systems, which may produce forecasts under 1) identical conditions or 2) different conditions. The first type of CV is matched comparative verification, and it is based on a 3-variable distribution with 6 possible factorizations. The second and more complicated type of CV is unmatched comparative verification, and it is based on a 4-variable distribution with 24 possible factorizations. Complexity can be defined in terms of the number of factorizations, the number of basic factors (conditional and marginal distributions) in each factorization, or the total number of basic factors associated with the respective frameworks. These definitions provide quantitative insight into basic differences in complexity among AV and CV problems. Verification problems involving probabilistic and nonprobabilistic forecasts are of equal complexity. Dimensionality is defined as the number of probabilities that must be specified to reconstruct the basic distribution of forecasts and observations. It is one less than the total number of distinct combinations of forecasts and observations. Thus, CV problems are of higher dimensionality than AV problems, and problems involving probabilistic forecasts or multivalued nonprobabilistic forecasts exhibit particularly high dimensionality. Issues related to the implications of these concepts for verification procedures and practices are discussed, including the reduction of complexity and/or dimensionality. Comparative verification problems can be reduced in complexity by making forecasts under identical conditions or by assuming conditional or unconditional independence when warranted. Dimensionality can be reduced by parametric statistical modeling of the distributions of forecasts and/or observations. Failure to take account of the complexity and dimensionality of verification problems may lead to an incomplete and inefficient body of verification methodology and, thereby, to erroneous conclusions regarding the absolute and relative quality and/or value of forecasting systems. C1 OREGON STATE UNIV,DEPT ATMOSPHER SCI & STAT,CORVALLIS,OR 97331. NOAA,NATL WEATHER SERV,NATL METEOROL CTR,UNIV CORP ATMOSPHER RES VISITING SCIENTIST PROGRAM,WASHINGTON,DC 20233. NR 12 TC 71 Z9 71 U1 0 U2 5 PU AMER METEOROLOGICAL SOC PI BOSTON PA 45 BEACON ST, BOSTON, MA 02108-3693 SN 0027-0644 J9 MON WEATHER REV JI Mon. Weather Rev. PD JUL PY 1991 VL 119 IS 7 BP 1590 EP 1601 DI 10.1175/1520-0493(1991)119<1590:FVICAD>2.0.CO;2 PG 12 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA FX881 UT WOS:A1991FX88100006 ER PT J AU HERMES, LG AF HERMES, LG TI COMPARISONS OF RAWINSONDE-DEDUCED KINEMATIC AND THERMODYNAMIC QUANTITIES WITH THOSE DEDUCED FROM VHF PROFILER OBSERVATIONS SO MONTHLY WEATHER REVIEW LA English DT Article ID MESOSCALE CONVECTIVE COMPLEXES; WIND; TEMPERATURE; DIAGNOSIS; PRESSURE AB The testing and evaluation of new observing systems (i.e., 50-MHz wind profilers) were listed among the goals of the 1985 Oklahoma-Kansas Preliminary Regional Experiment for STORM-Central (PRE-STORM). Using a PRE-STORM dataset from 12-13 May 1985, kinematic quantities computed from profiler winds are quantitatively compared with those computed from a dense network of rawinsonde wind observations. Both the generalized thermal wind equation and the geostrophic thermal wind equation are used to retrieve horizontal gradients of virtual temperature from the profiler wind observations. The resultant gradients are compared with those computed from rawinsonde temperature and moisture measurements. Comparisons of the kinematic quantities computed from the two data sources show some agreement in temporal trends. Comparisons of the detailed structure reveal significant differences. The temporal trends of the vertical motion fields obtained from the profilers and rawinsondes do not correspond. The virtual temperature gradients retrieved using profiler winds and the generalized thermal wind equation do not agree with those computed from rawinsonde temperature and humidity data. Overall, the use of the thermal wind equation and profiler wind observations to estimate thermal gradients was not successful. An example of detailed thermal structure from rawinsonde temperature and humidity data that was successfully detected using profiler winds and the generalized thermal wind equation is presented. The sampling characteristics and other sources of errors that hinder comprehensive comparisons of the observations from the various PRE-STORM sensors are discussed. RP HERMES, LG (reprint author), NOAA,ENVIRONM RES LAB,NATL SEVERE STORMS LAB,1313 HALLEY CIRCLE,NORMAN,OK 73069, USA. NR 29 TC 7 Z9 7 U1 0 U2 0 PU AMER METEOROLOGICAL SOC PI BOSTON PA 45 BEACON ST, BOSTON, MA 02108-3693 SN 0027-0644 J9 MON WEATHER REV JI Mon. Weather Rev. PD JUL PY 1991 VL 119 IS 7 BP 1693 EP 1712 DI 10.1175/1520-0493(1991)119<1693:CORDKA>2.0.CO;2 PG 20 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA FX881 UT WOS:A1991FX88100013 ER PT J AU KRINSKY, JL NOEL, W DIDION, DA ANDERSEN, SO AF KRINSKY, JL NOEL, W DIDION, DA ANDERSEN, SO TI THE UNITED-STATES NAVY CHLOROFLUOROCARBON (CFC) HALON PROGRAM SO NAVAL ENGINEERS JOURNAL LA English DT Discussion C1 NATL INST STAND & TECHNOL,BLDG & FIRE RES LAB,THERMAL MACHINERY GRP,GAITHERSBURG,MD. NR 0 TC 0 Z9 0 U1 0 U2 1 PU AMER SOC NAVAL ENG INC PI ALEXANDRIA PA 1452 DUKE STREET, ALEXANDRIA, VA 22314-3458 SN 0028-1425 J9 NAV ENG J JI Nav. Eng. J. PD JUL PY 1991 VL 103 IS 4 BP 111 EP 113 PG 3 WC Engineering, Marine; Engineering, Civil; Oceanography SC Engineering; Oceanography GA FY243 UT WOS:A1991FY24300022 ER PT J AU BURKE, JS MILLER, JM HOSS, DE AF BURKE, JS MILLER, JM HOSS, DE TI IMMIGRATION AND SETTLEMENT PATTERN OF PARALICHTHYS-DENTATUS AND P-LETHOSTIGMA IN AN ESTUARINE NURSERY GROUND, NORTH-CAROLINA, USA SO NETHERLANDS JOURNAL OF SEA RESEARCH LA English DT Article; Proceedings Paper CT 1ST INTERNATIONAL SYMP ON FLATFISH ECOLOGY CY NOV 19-23, 1990 CL TEXEL, NETHERLANDS SP NETHERLANDS INST SEA RES, NETHERLANDS INST FISHERY INVESTIGAT, COMMODITY BOARD FISH & FISHERY PROD, ROYAL NETHERLANDS ACAD ARTS & SCI ID PLAICE PLEURONECTES-PLATESSA; WESTERN WADDEN SEA; ENGLISH SOLE; BAY; POPULATION; MORTALITY; LARVAL; RECRUITMENT; CRUSTACEANS; PREDATION AB Immigration and settlement pattern of O-group summer flounder (Paralichthys dentatus) and southern flounder (P lethostigma) in an estuarine nursery are described. Flounders entering the estuary were transforming larvae. Despite their sympatric occurrence during larval immigration, the two species were found concentrated in different habitats. Sampling along transects within the estuary indicated that newly settled southern flounder were concentrated on tidal flats towards the head of the estuary while greatest numbers of summer flounder were captured on tidal flats in the middle reach of the system. Logistic regression analysis of presence/absence data indicated that salinity affected the distribution of southern flounder while substrate type was an important factor affecting the distribution of summer flounder. Numbers of both species on tidal flats declined in the spring, southern flounder appeared to move upstream to oligohaline riverine habitat and summer flounder appeared to move to high salinity salt marsh habitat. The segregated distribution apparent in juveniles is largely established during the immigration period. Differences in settling behaviour and subsequent movement and/or differential mortality occurring during settlement, appear important in determining the observed distribution of juvenile summer and southern flounder. C1 N CAROLINA STATE UNIV,DEPT ZOOL,RALEIGH,NC 27695. RP BURKE, JS (reprint author), NOAA,NATL MARINE FISHERIES SERV,SE FISHERIES CTR,BEAUFORT LAB,BEAUFORT,NC 28516, USA. NR 44 TC 95 Z9 96 U1 0 U2 2 PU NETHERLANDS INST SEA RES PI TEXEL PA PO BOX 59 1790 AB DEN BURG, TEXEL, NETHERLANDS SN 0077-7579 J9 NETH J SEA RES JI Neth. J. Sea Res. PD JUL PY 1991 VL 27 IS 3-4 BP 393 EP 405 PG 13 WC Marine & Freshwater Biology; Oceanography SC Marine & Freshwater Biology; Oceanography GA GB836 UT WOS:A1991GB83600019 ER PT J AU DEBENHAM, PH AYRES, RL CASSATT, WA JOHNSON, BC JOHNSON, RG LINDSTROM, ER LIPOSKY, PJ MARELLA, AB MOHR, DL WHITTAKER, JK WILKIN, ND WILSON, MAD TANG, CM SPRANGLE, P PENNER, S AF DEBENHAM, PH AYRES, RL CASSATT, WA JOHNSON, BC JOHNSON, RG LINDSTROM, ER LIPOSKY, PJ MARELLA, AB MOHR, DL WHITTAKER, JK WILKIN, ND WILSON, MAD TANG, CM SPRANGLE, P PENNER, S TI STATUS-REPORT ON THE NIST-NRL FREE-ELECTRON LASER SO NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH SECTION A-ACCELERATORS SPECTROMETERS DETECTORS AND ASSOCIATED EQUIPMENT LA English DT Article; Proceedings Paper CT 12TH INTERNATIONAL CONF ON FREE ELECTRON LASER ( FEL 90 ) CY SEP 17-21, 1990 CL PARIS, FRANCE SP CEA, CNRS, DIRECT RECH & ETUDES TECH, FREE ELECTRON LASER CONF 88, MINIST RECH & TECHNOL FRANCE, SECRETARIAT GEN DEF NATL FRANCE, USN, OFF NAVAL RES, AEROSPATIALE AB A free electron laser (FEL) user facility is being constructed at the National Institute of Standards and Technology (NIST) in collaboration with the Naval Research Laboratory (NRL). The FEL, which will be operated as an oscillator, will be driven by the 17 to 185 MeV electron beam of the NIST continuous-wave racetrack microtron. Anticipated performance of the FEL includes: wavelength tuneable from 200 nm to 10-mu-m, a continuous train of 3 ps pulses at either 16.5 or 66.1 MHz, and average power of 10 to 200 W. Construction of the RTM will be completed in May, 1991. The 3.64 m long undulator is assembled at the factory and is scheduled to be delivered in February, 1991. The measured rms field error is 0.6%, which is sufficiently small for good gain. Due to the broad tuning range, the use of lasers to align the cavity end mirrors is impractical. With a full-scale model of the 9 m long optical cavity, we have developed a method of aligning the mirrors to the required accuracy using white light and an autocollimator/telescope. We have performed three-dimensional simulations of performance including the effects of the electron beam (emittance, pulse length and shape, and timing jitter), undulator field errors, and cavity losses. These calculations predict adequate gain for lasing across the full wavelength range. Additional calculations are underway to predict the performance at saturation. C1 USN,RES LAB,WASHINGTON,DC 20375. RP DEBENHAM, PH (reprint author), NATL INST STAND & TECHNOL,GAITHERSBURG,MD 20899, USA. NR 10 TC 2 Z9 2 U1 0 U2 1 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0168-9002 J9 NUCL INSTRUM METH A JI Nucl. Instrum. Methods Phys. Res. Sect. A-Accel. Spectrom. Dect. Assoc. Equip. PD JUL 1 PY 1991 VL 304 IS 1-3 BP 208 EP 211 PG 4 WC Instruments & Instrumentation; Nuclear Science & Technology; Physics, Nuclear; Physics, Particles & Fields SC Instruments & Instrumentation; Nuclear Science & Technology; Physics GA FV595 UT WOS:A1991FV59500043 ER PT J AU KIM, YK BAIK, DH INDELICATO, P DESCLAUX, JP AF KIM, YK BAIK, DH INDELICATO, P DESCLAUX, JP TI RESONANCE TRANSITION ENERGIES OF LI-LIKE, NA-LIKE, AND CU-LIKE IONS SO PHYSICAL REVIEW A LA English DT Article ID PERTURBATION-THEORY CALCULATIONS; MULTICONFIGURATIONAL DIRAC-FOCK; COPPER ISOELECTRONIC SEQUENCE; ZN-LIKE IONS; QED CORRECTIONS; RADIATIVE-CORRECTIONS; 3-ELECTRON IONS; SELF-ENERGY; LAMB SHIFT; ATOMS AB Relativistic correlation energies are determined by taking the difference between the energies derived from the relativistic many-body perturbation method and those from the Dirac-Fock method for the resonance transitions of Li-, Na-, and Cu-like ions. These correlation energies are combined with the Dirac-Fock energies and ''screened'' QED corrections based on approximate methods. The resulting theoretical transition energies are compared with available experimental data along isoelectronic sequences to identify irregularities in the data and to predict transition energies of ions whose values are unknown or uncertain. C1 CEN,DEPT RECH FONDAMENTALE,SERV PHYS ATOM,F-38041 GRENOBLE,FRANCE. KOREA ATOM ENERGY RES INST,TAEJON 302353,SOUTH KOREA. RP KIM, YK (reprint author), NATL INST STAND & TECHNOL,GAITHERSBURG,MD 20899, USA. RI Indelicato, Paul/D-7636-2011 OI Indelicato, Paul/0000-0003-4668-8958 NR 51 TC 157 Z9 159 U1 0 U2 3 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 1050-2947 J9 PHYS REV A JI Phys. Rev. A PD JUL 1 PY 1991 VL 44 IS 1 BP 148 EP 166 DI 10.1103/PhysRevA.44.148 PG 19 WC Optics; Physics, Atomic, Molecular & Chemical SC Optics; Physics GA FV184 UT WOS:A1991FV18400025 ER PT J AU KAMITAKAHARA, WA CAPPELLETTI, RL BOOLCHAND, P HALFPAP, B GOMPF, F NEUMANN, DA MUTKA, H AF KAMITAKAHARA, WA CAPPELLETTI, RL BOOLCHAND, P HALFPAP, B GOMPF, F NEUMANN, DA MUTKA, H TI VIBRATIONAL DENSITIES OF STATES AND NETWORK RIGIDITY IN CHALCOGENIDE GLASSES SO PHYSICAL REVIEW B LA English DT Article AB Vibrational spectra have been measured by neutron scattering for a series of Se-Ge and Se-As-Ge glasses, spanning a wide range in composition and, consequently, in network connectivity. Low-frequency "floppy" modes arising from underconstrained atomic configurations have been observed, in qualitative agreement with recent theories of the dynamics of network glasses. The number of floppy modes was found to depend only on the average coordination number . There is some indication of a rigidity percolation threshold at almost-equal-to 2.4, but the effect in the vibrational densities of states is not dramatic. The wave-vector dependence of the scattering at low vibrational energies (almost-equal-to 2 meV) is acoustic-phonon-like. Specific heats C calculated from the measured densities of states show a strongly composition-dependent bump in C/T3 near 4 K, in accord with experiment. C1 UNIV MARYLAND,DEPT PHYS,COLLEGE PK,MD 20742. OHIO UNIV,DEPT PHYS & ASTRON,ATHENS,OH 45701. OHIO UNIV,CONDENSED MATTER & SURFACE SCI PROGRAM,ATHENS,OH 45701. UNIV CINCINNATI,DEPT ELECT & COMP ENGN,CINCINNATI,OH 45221. ARIZONA STATE UNIV,DEPT PHYS,TEMPE,AZ 85287. KERNFORSCHUNGSZENTRUM KARLSRUHE GMBH,INST NUKL FESTKORPERPHYS,W-7500 KARLSRUHE 1,GERMANY. INST MAX VON LAUE PAUL LANGEVIN,F-38042 GRENOBLE,FRANCE. RP KAMITAKAHARA, WA (reprint author), NATL INST STAND & TECHNOL,DIV REACTOR RADIAT,GAITHERSBURG,MD 20899, USA. RI Boolchand, Punit/A-3334-2008 NR 17 TC 120 Z9 120 U1 0 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 JUL 1 PY 1991 VL 44 IS 1 BP 94 EP 100 DI 10.1103/PhysRevB.44.94 PG 7 WC Physics, Condensed Matter SC Physics GA FU902 UT WOS:A1991FU90200012 ER PT J AU ZHU, M OATES, CW HALL, JL AF ZHU, M OATES, CW HALL, JL TI CONTINUOUS HIGH-FLUX MONOVELOCITY ATOMIC-BEAM BASED ON A BROAD-BAND LASER-COOLING TECHNIQUE SO PHYSICAL REVIEW LETTERS LA English DT Article ID RADIATION; VELOCITY AB We report application of Hoffnagle's broadband cooling concept to cool Na atoms in an atomic beam. The rms velocity spread of the cooled atoms is 0.75 +/- 0.05 m/s (1.5 +/- 0.2 mK) with a flux of (9.5 +/- 1.0) x l0(8) atoms/s. 1D broadband optical molasses is also demonstrated. Potential applications of the cooling scheme are discussed. RP ZHU, M (reprint author), UNIV COLORADO,NATL INST STAND & TECHNOL,JOINT INST LAB ASTROPHYS,BOULDER,CO 80302, USA. NR 19 TC 82 Z9 85 U1 1 U2 4 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 0031-9007 J9 PHYS REV LETT JI Phys. Rev. Lett. PD JUL 1 PY 1991 VL 67 IS 1 BP 46 EP 49 DI 10.1103/PhysRevLett.67.46 PG 4 WC Physics, Multidisciplinary SC Physics GA FU343 UT WOS:A1991FU34300013 ER PT J AU UNGURIS, J CELOTTA, RJ PIERCE, DT AF UNGURIS, J CELOTTA, RJ PIERCE, DT TI OBSERVATION OF 2 DIFFERENT OSCILLATION PERIODS IN THE EXCHANGE COUPLING OF FE/CR/FE(100) SO PHYSICAL REVIEW LETTERS LA English DT Article ID LAYERED MAGNETIC-STRUCTURES; GIANT MAGNETORESISTANCE; INTERLAYER EXCHANGE; FE LAYERS; SUPERLATTICES; CR; FE/CR AB Oscillations of ferromagnetic to antiferromagnetic exchange coupling between two Fe layers separated by a Cr spacer of linearly increasing thickness were investigated by imaging the magnetic domains with scanning electron microscopy with polarization analysis. Up to six oscillations in the coupling with a period of 10-12 Cr layers were observed, and, in the case of an extremely well ordered Cr interlayer, additional oscillations with a period of 2 Cr layers were observed. RP UNGURIS, J (reprint author), NATL INST STAND & TECHNOL,GAITHERSBURG,MD 20899, USA. RI Unguris, John/J-3989-2014 NR 20 TC 556 Z9 561 U1 7 U2 26 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 0031-9007 J9 PHYS REV LETT JI Phys. Rev. Lett. PD JUL 1 PY 1991 VL 67 IS 1 BP 140 EP 143 DI 10.1103/PhysRevLett.67.140 PG 4 WC Physics, Multidisciplinary SC Physics GA FU343 UT WOS:A1991FU34300037 ER PT J AU JESPERSEN, J HANSON, DW AF JESPERSEN, J HANSON, DW TI TIME AND FREQUENCY SO PROCEEDINGS OF THE IEEE LA English DT Editorial Material C1 US DEPT COMMERCE,NATL INST STAND & TECHNOL,TIME & FREQUENCY SERV GRP,BOULDER,CO 80303. RP JESPERSEN, J (reprint author), US DEPT COMMERCE,NATL INST STAND & TECHNOL,DIV TIME & FREQUENCY,325 BROADWAY,BOULDER,CO 80303, USA. NR 0 TC 7 Z9 7 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 0018-9219 J9 P IEEE JI Proc. IEEE PD JUL PY 1991 VL 79 IS 7 BP 891 EP 893 PG 3 WC Engineering, Electrical & Electronic SC Engineering GA GF210 UT WOS:A1991GF21000001 ER PT J AU SULLIVAN, DB LEVINE, J AF SULLIVAN, DB LEVINE, J TI TIME GENERATION AND DISTRIBUTION SO PROCEEDINGS OF THE IEEE LA English DT Article ID FREQUENCY STANDARD; COMMON-VIEW; SYNCHRONIZATION; BEAM; NIST AB This paper presents a broad overview of time and frequency technology, particularly those trends relating to the generation and distribution of time and frequency signals. The characterization of components and systems is also addressed. RP SULLIVAN, DB (reprint author), NATL INST STAND & TECHNOL,DIV TIME & FREQUENCY,BOULDER,CO 80303, USA. NR 49 TC 4 Z9 4 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 0018-9219 J9 P IEEE JI Proc. IEEE PD JUL PY 1991 VL 79 IS 7 BP 906 EP 914 DI 10.1109/5.84966 PG 9 WC Engineering, Electrical & Electronic SC Engineering GA GF210 UT WOS:A1991GF21000003 ER PT J AU ITANO, WM AF ITANO, WM TI ATOMIC ION FREQUENCY STANDARDS SO PROCEEDINGS OF THE IEEE LA English DT Article ID RF QUADRUPOLE TRAP; PRECISE DETERMINATION; STORED IONS; LASER; SPECTROSCOPY; MACROMOTION; OSCILLATOR; SINGLE; GAS AB A new class of atomic frequency standard, based on ions trapped by electromagnetic fields, is under development. Such standards have the potential of achieving higher frequency accuracy than currently available standards. They are also capable of very good frequency stability. The history and status of trapped-ion frequency standards are reviewed. Prospects for future standards are discussed. RP ITANO, WM (reprint author), NATL INST STAND & TECHNOL,DIV TIME & FREQUENCY,BOULDER,CO 80303, USA. NR 46 TC 14 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 0018-9219 J9 P IEEE JI Proc. IEEE PD JUL PY 1991 VL 79 IS 7 BP 936 EP 942 DI 10.1109/5.84970 PG 7 WC Engineering, Electrical & Electronic SC Engineering GA GF210 UT WOS:A1991GF21000007 ER PT J AU ROLSTON, SL PHILLIPS, WD AF ROLSTON, SL PHILLIPS, WD TI LASER-COOLED NEUTRAL ATOM FREQUENCY STANDARDS SO PROCEEDINGS OF THE IEEE LA English DT Article ID METASTABLE ATOMS; DOPPLER LIMIT; SODIUM ATOMS; SPECTROSCOPY; RADIATION; TRAP; MOLASSES; FOUNTAIN; DIVISION AB Recent advances in laser cooling, including temperatures as low a few microkelvin, and the demonstration of the ability to launch atoms while maintaining these low temperatures, now allows the realization of atomic fountain frequency standards. An analysis of a Cs microwave fountain predicts potential stability and accuracy improvements of a factor of 100 over present laboratory standards, with an ultimate accuracy near 10(-16). An optical frequency standard based on a two-photon transition in xenon is analyzed and shown to have potential stability 5 orders of magnitude better than current Cs standards, and a possible accuracy of 10(-18). Neutral atom frequency standards will have much better signal-to-noise (S/N) ratios than ion standards, but suffer from larger systematic effects, making the two technologies complementary in many ways. RP ROLSTON, SL (reprint author), NATL INST STAND & TECHNOL,DIV ATOM PHYS,PHYS LAB,GAITHERSBURG,MD 20899, USA. RI rolston, steven/L-5175-2013 OI rolston, steven/0000-0003-1671-4190 NR 43 TC 25 Z9 25 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 0018-9219 J9 P IEEE JI Proc. IEEE PD JUL PY 1991 VL 79 IS 7 BP 943 EP 951 DI 10.1109/5.84971 PG 9 WC Engineering, Electrical & Electronic SC Engineering GA GF210 UT WOS:A1991GF21000008 ER PT J AU RUTMAN, J WALLS, FL AF RUTMAN, J WALLS, FL TI CHARACTERIZATION OF FREQUENCY STABILITY IN PRECISION FREQUENCY SOURCES SO PROCEEDINGS OF THE IEEE LA English DT Article AB This paper presents a short review of the progress that has occurred over the past 25-30 years in both the theoretical and practical characterization of frequency stability of precision frequency sources. The emphasis is on the evolution of ideas and concepts for the characterization of random noise processes in such standards in the time domain and the Fourier frequency domain, rather than a rigorous mathematical treatment of the problem. Numerous references to the mathematical treatments are made. C1 NATL INST STAND & TECHNOL,DIV TIME & FREQUENCY,BOULDER,CO 80303. RP RUTMAN, J (reprint author), FEDERAT IND ELECT & ELECTR,F-75116 PARIS,FRANCE. NR 42 TC 112 Z9 119 U1 1 U2 3 PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017-2394 SN 0018-9219 J9 P IEEE JI Proc. IEEE PD JUL PY 1991 VL 79 IS 7 BP 952 EP 960 DI 10.1109/5.84972 PG 9 WC Engineering, Electrical & Electronic SC Engineering GA GF210 UT WOS:A1991GF21000009 ER PT J AU SENGUPTA, A HANJURA, AK MATHUR, BS AF SENGUPTA, A HANJURA, AK MATHUR, BS TI SATELLITE BROADCASTING OF TIME AND FREQUENCY SIGNALS SO PROCEEDINGS OF THE IEEE LA English DT Article AB This paper discusses the advantages of broadcasting time from a satellite over the more traditional ground based methods such as short wave and low frequency standard time and frequency broadcasts. The paper describes several one way satellite time services currently operational and discusses, in particular, a broadcast service using the Indian domestic satellite INSAT. The signal format, transmitting and receiving setups and the methods for satellite position prediction are described in detail for the INSAT broadcast. Some typical results of time and frequency calibration are also discussed. C1 NATL PHYS LAB,DIV TIME & FREQUENCY,NEW DELHI 110012,INDIA. RP SENGUPTA, A (reprint author), US DEPT COMMERCE,NATL INST STAND & TECHNOL,WASHINGTON,DC 20230, USA. NR 35 TC 5 Z9 5 U1 5 U2 5 PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017-2394 SN 0018-9219 J9 P IEEE JI Proc. IEEE PD JUL PY 1991 VL 79 IS 7 BP 973 EP 982 DI 10.1109/5.84974 PG 10 WC Engineering, Electrical & Electronic SC Engineering GA GF210 UT WOS:A1991GF21000011 ER PT J AU MATROSOV, SY AF MATROSOV, SY TI PROSPECTS FOR THE MEASUREMENT OF ICE-CLOUD PARTICLE-SHAPE AND ORIENTATION WITH ELLIPTICALLY POLARIZED RADAR SIGNALS SO RADIO SCIENCE LA English DT Article AB A method to estimate cloud particle orientation and shape parameters using a polarization diversity radar is presented. The method is demonstrated for low-reflectivity ice clouds containing crystals that are modeled as prolate and oblate spheroids. The parameters to be estimated are the particle mean canting angle and the axis ratio in the incident wave polarization plane. The scattering matrix concept is used to obtain a relationship between two orthogonally polarized received powers and the parameters of interest. It is shown that the use of an elliptically polarized radar signal diminishes the expected difference between received powers in the two receiving polarization channels. This makes polarization studies of ice clouds with relatively low reflectivities possible; these clouds often are "invisible" in one of the receiving channels when conventional linear or circular polarization is used. An estimation of errors in the retrieved mean canting angle value caused by the spread in particle orientation is also given. RP MATROSOV, SY (reprint author), NOAA,WAVE PROPAGAT LAB,325 BROADWAY,BOULDER,CO 80303, USA. NR 15 TC 10 Z9 10 U1 0 U2 0 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 SN 0048-6604 J9 RADIO SCI JI Radio Sci. PD JUL-AUG PY 1991 VL 26 IS 4 BP 847 EP 856 DI 10.1029/91RS00965 PG 10 WC Astronomy & Astrophysics; Geochemistry & Geophysics; Meteorology & Atmospheric Sciences; Remote Sensing; Telecommunications SC Astronomy & Astrophysics; Geochemistry & Geophysics; Meteorology & Atmospheric Sciences; Remote Sensing; Telecommunications GA FZ016 UT WOS:A1991FZ01600004 ER PT J AU DAVIES, K LIU, XM AF DAVIES, K LIU, XM TI IONOSPHERIC SLAB THICKNESS IN MIDDLE AND LOW LATITUDES SO RADIO SCIENCE LA English DT Article AB The equivalent slab thickness of the ionosphere at 15 stations in middle and low latitudes was studied to determine its dependence on solar cycle and location. The data were grouped by season. The following are the major conclusions. There appears to be little or no geographical, or geomagnetic, dependence. The slab thickness varies approximately linearly with the 12-month smoothed values of the 10.7-cm solar radio flux. In middle latitudes the winter midnight thickness is essentially independent of the flux, whereas in summer and equinox the midnight thickness increases with increase of solar flux. The noon thickness increases with increase of solar flux in all seasons. The zero-order Fourier coefficients for the diurnal curves at all 15 stations were expressed as linear functions of the 10.7-cm flux. The higher harmonic coefficients showed no appreciable dependence on solar flux. The pronounced predawn increase in slab thickness is caused by low values of the maximum electron density, not by increase of total electron content. C1 WYCOMBE GEN HOSP,DEPT SPACE PHYS,HIGH WYCOMBE,BUCKS,ENGLAND. RP DAVIES, K (reprint author), NOAA,SPACE ENVIRONM LAB,BOULDER,CO 80303, USA. NR 10 TC 41 Z9 41 U1 2 U2 4 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 SN 0048-6604 J9 RADIO SCI JI Radio Sci. PD JUL-AUG PY 1991 VL 26 IS 4 BP 997 EP 1005 DI 10.1029/91RS00831 PG 9 WC Astronomy & Astrophysics; Geochemistry & Geophysics; Meteorology & Atmospheric Sciences; Remote Sensing; Telecommunications SC Astronomy & Astrophysics; Geochemistry & Geophysics; Meteorology & Atmospheric Sciences; Remote Sensing; Telecommunications GA FZ016 UT WOS:A1991FZ01600019 ER PT J AU SHANG, EC WANG, YY AF SHANG, EC WANG, YY TI ON THE CALCULATION OF MODAL TRAVEL TIME PERTURBATION SO SOVIET PHYSICS ACOUSTICS-USSR LA English DT Article ID GROUP-VELOCITY AB In modal ocean acoustic tomography, the modal travel time is the basic measurement for inverting the ocean structure. 1-3 We recently made substantial calculations of modal travel time perturbation caused by large-scale oceanic structures at the U.S. National Oceanic and Atmospheric Administration (NOAA) Wave propagation Laboratory (WPL) on CYBER 205 for numerical simulations. In this paper we give the results of calculating modal travel time perturbation caused by a mesoscale eddy using three different methods with a sophisticated normal mode code called KRAKEN. 4 RP SHANG, EC (reprint author), UNIV COLORADO,NOAA,COOPERAT INST RES ENVIRONM SCI,NOAA,WAVE PROPAGAT LAB,BOULDER,CO 80309, USA. NR 7 TC 6 Z9 6 U1 0 U2 0 PU AMER INST PHYSICS PI WOODBURY PA CIRCULATION FULFILLMENT DIV, 500 SUNNYSIDE BLVD, WOODBURY, NY 11797-2999 SN 0038-562X J9 SOV PHYS ACOUST+ PD JUL-AUG PY 1991 VL 37 IS 4 BP 411 EP 413 PG 3 WC Acoustics SC Acoustics GA GZ768 UT WOS:A1991GZ76800028 ER PT J AU PETERS, DS SCHAAF, WE AF PETERS, DS SCHAAF, WE TI EMPIRICAL-MODEL OF THE TROPHIC BASIS FOR FISHERY YIELD IN COASTAL WATERS OF THE EASTERN USA SO TRANSACTIONS OF THE AMERICAN FISHERIES SOCIETY LA English DT Article ID LENGTH-WEIGHT RELATIONSHIP; FOOD-HABITS; PSEUDOPLEURONECTES-AMERICANUS; SCIAENOPS-OCELLATA; RED DRUM; LOUISIANA; MENHADEN; BAY AB A synthesis of information describing the trophic basis for production of marine fishery yield along the east coast of the USA from New York through Georgia is presented. It includes a documentation of the species composition and magnitude of fishery harvest, a delineation of the major food chains, and an estimate of the flow rates of organic matter through populations of yield species. In order to place the information on fishery food webs in appropriate context, we related it to primary production within the system and trophic structure of other systems that have been described. We conclude that (1) algal production is inadequate to support the existing system, and vascular plant production is required; (2) detritus, a frequent dietary constituent, retains at least 42% of the organic material from which it was derived, when it is ingested; (3) the system efficiently converts available organic matter to harvested species through direct paths; and (4) evaluations of fish production in this system may be advanced most rapidly by research on detritus production and use, species composition and diets of forage fish, and mortality rates of both forage fish and prerecruits of yield species. RP PETERS, DS (reprint author), NOAA,NATL MARINE FISHERIES SERV,SE FISHERIES CTR,BEAUFORT LAB,BEAUFORT,NC 28516, USA. NR 77 TC 17 Z9 17 U1 0 U2 1 PU AMER FISHERIES SOC PI BETHESDA PA 5410 GROSVENOR LANE SUITE 110, BETHESDA, MD 20814-2199 SN 0002-8487 J9 T AM FISH SOC JI Trans. Am. Fish. Soc. PD JUL PY 1991 VL 120 IS 4 BP 459 EP 473 DI 10.1577/1548-8659(1991)120<0459:EMOTTB>2.3.CO;2 PG 15 WC Fisheries SC Fisheries GA GC662 UT WOS:A1991GC66200005 ER PT J AU GATES, RS HSU, SM AF GATES, RS HSU, SM TI EFFECT OF SELECTED CHEMICAL-COMPOUNDS ON THE LUBRICATION OF SILICON-NITRIDE SO TRIBOLOGY TRANSACTIONS LA English DT Article; Proceedings Paper CT TRIBOLOGY CONF CY OCT 08-10, 1990 CL TORONTO, CANADA SP AMER SOC MECH ENGINEERS, SOC TRIBOLOGISTS & LUBRICAT ENGINEERS ID MOLTEN-SALT CORROSION; WEAR AB Successful use of advanced ceramics in many tribological applications requires an understanding of the physical, chemical, and mechanical properties of the material. Physical and mechanical data are relatively abundant for most ceramics. However, information on the chemical interactions of ceramics is scarce. This is especially true for chemical interactions with regard to lubrication of these materials. This paper investigates the influence of selected chemical compounds on the friction and wear of silicon nitride under boundary lubrication conditions. A ball-on-three-flat modification of the four-ball wear tester was utilized to evaluate the tribological characteristics of a hot pressed silicon nitride lubricated with a paraffinic base oil containing 1 weight percent additives. Friction, wear, and film formation tendencies were observed for a range of oil soluble chemical compounds containing oxygen, sulfur, nitrogen, chlorine, and phosphorous. A wide range of additive response was observed. Friction coefficient varied from increases of 30 percent to decreases of 47 percent below that of the base case of paraffin oil without additive. Wear was measured as the wear scar diameter increase above the Hertz diameter. Relative to the base case, wear additive response ranged from an increase in diameter of 61 percent to a decrease of 96 percent. Successful wear reduction was obtained by all phosphorus containing compounds, several glycol compounds, oleic acid, sulfonates, a salicylate, an imidazoline, and a phenate, and was generally associated with the formation of a film in the contact region. RP GATES, RS (reprint author), NATL INST STAND & TECHNOL,DIV CERAM,GAITHERSBURG,MD 20899, USA. NR 19 TC 45 Z9 45 U1 2 U2 3 PU SOC TRIBOLOGISTS & LUBRICATION ENGINEERS PI PARK RIDGE PA 838 BUSSE HIGHWAY, PARK RIDGE, IL 60068 SN 0569-8197 J9 TRIBOL T JI Tribol. Trans. PD JUL PY 1991 VL 34 IS 3 BP 417 EP 425 DI 10.1080/10402009108982052 PG 9 WC Engineering, Mechanical SC Engineering GA FU915 UT WOS:A1991FU91500013 ER PT J AU SEKI, MP MUNDY, BC AF SEKI, MP MUNDY, BC TI SOME NOTES ON THE EARLY LIFE STAGES OF THE PACIFIC POMFRET, BRAMA-JAPONICA, AND OTHER BRAMIDAE FROM THE CENTRAL NORTH PACIFIC-OCEAN SO JAPANESE JOURNAL OF ICHTHYOLOGY LA English DT Note ID FISHES RP SEKI, MP (reprint author), NOAA,NATL MARINE FISHERIES SERV,SW FISHERIES SCI CTR,HONOLULU LAB,2570 DOLE ST,HONOLULU,HI 96822, USA. NR 19 TC 6 Z9 6 U1 0 U2 0 PU ICHTHYOLOGICAL SOC JAPAN PI TOKYO PA BUSINESS CENTER ACADEMIC SOC JAPAN, 5-16-9 HONKOMAGOME, BUNKYO-KU, TOKYO 113, JAPAN SN 0021-5090 J9 JPN J ICHTHYOL JI Jpn. J. Ichthyol. PD JUN 28 PY 1991 VL 38 IS 1 BP 63 EP 68 PG 6 WC Fisheries; Zoology SC Fisheries; Zoology GA FY967 UT WOS:A1991FY96700011 ER PT J AU SCHNELL, RC LIU, SC OLTMANS, SJ STONE, RS HOFMANN, DJ DUTTON, EG DESHLER, T STURGES, WT HARDER, JW SEWELL, SD TRAINER, M HARRIS, JM AF SCHNELL, RC LIU, SC OLTMANS, SJ STONE, RS HOFMANN, DJ DUTTON, EG DESHLER, T STURGES, WT HARDER, JW SEWELL, SD TRAINER, M HARRIS, JM TI DECREASE OF SUMMER TROPOSPHERIC OZONE CONCENTRATIONS IN ANTARCTICA SO NATURE LA English DT Article ID PROFILE MEASUREMENTS; MCMURDO STATION; DESTRUCTION; PACIFIC; HOLE AB AS an oxidant and a precursor for other highly reactive oxidants, ozone plays an important role in tropospheric photochemistry. In the upper troposphere, ozone absorbs infrared radiation and is thus an effective greenhouse gas 1. Here we show that surface ozone concentrations at the South Pole in the austral summer decreased by 17% over the period 1976-90. Over the same period, solar irradiance at the South Pole in January and February decreased by 7% as a result of a 25% increase in cloudiness. We suggest that the trend in the summer ozone concentrations is caused by enhanced photochemical destruction of ozone in the lower troposphere caused by the increased penetration of ultraviolet radiation associated with stratospheric ozone depletion, coupled with enhanced transport of ozone-poor marine air from lower latitudes to the South Pole. C1 NOAA,AERON LAB,BOULDER,CO 80303. NOAA,CLIMATE MONITORING & DIAGNOST LAB,BOULDER,CO 80303. UNIV WYOMING,DEPT PHYS & ASTRON,LARAMIE,WY 82071. UNIV COLORADO,DEPT GEOG,BOULDER,CO 80303. RP SCHNELL, RC (reprint author), UNIV COLORADO,NOAA,COOPERAT INST RES ENVIRONM SCI,BOULDER,CO 80309, USA. RI Trainer, Michael/H-5168-2013 NR 36 TC 52 Z9 54 U1 0 U2 0 PU MACMILLAN MAGAZINES LTD PI LONDON PA 4 LITTLE ESSEX STREET, LONDON, ENGLAND WC2R 3LF SN 0028-0836 J9 NATURE JI Nature PD JUN 27 PY 1991 VL 351 IS 6329 BP 726 EP 729 DI 10.1038/351726a0 PG 4 WC Multidisciplinary Sciences SC Science & Technology - Other Topics GA FU201 UT WOS:A1991FU20100057 ER PT J AU CAPPELLETTI, RL COPLEY, JRD KAMITAKAHARA, WA LI, F LANNIN, JS RAMAGE, D AF CAPPELLETTI, RL COPLEY, JRD KAMITAKAHARA, WA LI, F LANNIN, JS RAMAGE, D TI NEUTRON MEASUREMENTS OF INTRAMOLECULAR VIBRATIONAL-MODES IN C60 SO PHYSICAL REVIEW LETTERS LA English DT Article ID BUCKMINSTERFULLERENE; C-60 AB Neutron-inelastic-scattering measurements have been made on a sample of highly purified solid C60. New features in the spectrum of intramolecular modes not obtainable by optical spectroscopy have been identified. Available theoretical calculations show trends in accord with the experimental results but disagree in important details, and improved calculations are desirable. C1 OHIO UNIV,CONDENSED MATTER & SURFACE SCI PROGRAM,ATHENS,OH 45701. NATL INST STAND & TECHNOL,MAT SCI & ENGN LAB,GAITHERSBURG,MD 20899. UNIV MARYLAND,DEPT PHYS & ASTRON,COLLEGE PK,MD 20742. PENN STATE UNIV,DEPT PHYS,UNIVERSITY PK,PA 16802. PENN STATE UNIV,DEPT CHEM,UNIVERSITY PK,PA 16802. RP CAPPELLETTI, RL (reprint author), OHIO UNIV,DEPT PHYS & ASTRON,ATHENS,OH 45701, USA. NR 18 TC 122 Z9 122 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 JUN 24 PY 1991 VL 66 IS 25 BP 3261 EP 3264 DI 10.1103/PhysRevLett.66.3261 PG 4 WC Physics, Multidisciplinary SC Physics GA FT113 UT WOS:A1991FT11300009 ER PT J AU HILL, JP THURSTON, TR ERWIN, RW RAMSTAD, MJ BIRGENEAU, RJ AF HILL, JP THURSTON, TR ERWIN, RW RAMSTAD, MJ BIRGENEAU, RJ TI TRANSITION TO LONG-RANGE ORDER IN THE 3-DIMENSIONAL RANDOM-FIELD ISING-MODEL SO PHYSICAL REVIEW LETTERS LA English DT Article ID X-RAY SCATTERING; PHASE-TRANSITIONS; SYSTEMS; BEHAVIOR AB We report both synchrotron-x-ray and neutron-diffraction studies of the magnetic ordering in a crystal of Mn0.75Zn0.25F2 in a magnetic field. The neutron experiments reproduce previous results showing the establishment of a short-range domain state on cooling in a field. Remarkably, the magnetic x-ray scattering shows that within a few microns of the surface there is a second-order transition to true long-range order on field cooling. Implications of these results are discussed. C1 SANDIA NATL LABS,ALBUQUERQUE,NM 87185. NATL INST STAND & TECHNOL,GAITHERSBURG,MD 20899. RP HILL, JP (reprint author), MIT,DEPT PHYS,CAMBRIDGE,MA 02139, USA. RI Hill, John/F-6549-2011 NR 20 TC 48 Z9 48 U1 2 U2 2 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 0031-9007 J9 PHYS REV LETT JI Phys. Rev. Lett. PD JUN 24 PY 1991 VL 66 IS 25 BP 3281 EP 3284 DI 10.1103/PhysRevLett.66.3281 PG 4 WC Physics, Multidisciplinary SC Physics GA FT113 UT WOS:A1991FT11300014 ER PT J AU MILLER, HC YAMASAKI, K SMEDLEY, JE LEONE, SR AF MILLER, HC YAMASAKI, K SMEDLEY, JE LEONE, SR TI AN OPTICALLY PUMPED ULTRAVIOLET-LASER ON SO(B 3-SIGMA--X 3-SIGMA-) SO CHEMICAL PHYSICS LETTERS LA English DT Article ID SUPERSONIC-BEAM LASER; DIMER LASERS; STIMULATED-EMISSION; EXCITED-STATES; 193 NM; SO2; PHOTODISSOCIATION; OSCILLATION; SODIUM; SYSTEM AB Lasing has been demonstrated in sulfur monoxide by pulsed optical pumping of transitions in the (0, 2) band of SO(B 3-SIGMA- - X 3-SIGMA-) at 256 nm. The SO is produced by 193 nm photolysis of sulfur dioxide. Stimulated emission is observed in the (0, 8), (0, 9), (0, 10), and (0, 11) bands between 300 and 350 nm. C1 UNIV COLORADO,DEPT PHYS,BOULDER,CO 80309. RP MILLER, HC (reprint author), UNIV COLORADO,NATL INST STAND & TECHNOL,JOINT INST LAB ASTROPHYS,BOULDER,CO 80302, USA. NR 39 TC 10 Z9 10 U1 0 U2 3 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0009-2614 J9 CHEM PHYS LETT JI Chem. Phys. Lett. PD JUN 21 PY 1991 VL 181 IS 2-3 BP 250 EP 254 DI 10.1016/0009-2614(91)90362-D PG 5 WC Chemistry, Physical; Physics, Atomic, Molecular & Chemical SC Chemistry; Physics GA FU295 UT WOS:A1991FU29500025 ER PT J AU CHENEY, RE DOUGLAS, BC AF CHENEY, RE DOUGLAS, BC TI SATELLITE OCEANOGRAPHY IN THE 1980S SO SCIENCE LA English DT Letter RP CHENEY, RE (reprint author), NOAA,NATL GEODET SURVEY,ROCKVILLE,MD 20852, USA. NR 1 TC 0 Z9 0 U1 0 U2 0 PU AMER ASSOC ADVANCEMENT SCIENCE PI WASHINGTON PA 1200 NEW YORK AVE, NW, WASHINGTON, DC 20005 SN 0036-8075 J9 SCIENCE JI Science PD JUN 21 PY 1991 VL 252 IS 5013 BP 1599 EP 1599 DI 10.1126/science.252.5013.1599-b PG 1 WC Multidisciplinary Sciences SC Science & Technology - Other Topics GA FT114 UT WOS:A1991FT11400004 ER PT J AU BALDWIN, JA FERLAND, GJ MARTIN, PG CORBIN, MR COTA, SA PETERSON, BM SLETTEBAK, A AF BALDWIN, JA FERLAND, GJ MARTIN, PG CORBIN, MR COTA, SA PETERSON, BM SLETTEBAK, A TI PHYSICAL CONDITIONS IN THE ORION NEBULA AND AN ASSESSMENT OF ITS HELIUM ABUNDANCE SO ASTROPHYSICAL JOURNAL LA English DT Article DE NEBULAE, ABUNDANCES; NEBULAE, H-II REGIONS; NEBULAE, ORION NEBULA ID H-II REGIONS; INFRARED LINE OBSERVATIONS; ACTIVE GALACTIC NUCLEI; PHOTODISSOCIATION REGIONS; MODEL ATMOSPHERES; PRIMORDIAL HELIUM; SIZE DISTRIBUTION; GASEOUS NEBULAE; FORBIDDEN LINES; O-III AB The Orion Nebula is pivotal in establishing the "dY/dZ relation," which describes both the enrichment of helium as stars produce heavy elements and, from an extrapolation to a condition of no enrichment, the primordial helium abundance. With the goal of redetermining the helium abundance of the Orion Nebula, we have obtained new long-slit spectrophotometric observations. These observations confirm previously noted trends that the density, level of ionization, and emission measure decrease with the distance from the Trapezium. The reddening, measured from ratios of Paschen to Balmer lines, must arise mostly in a neutral sheet in front of the H II region. Most of the hydrogen line emission originates in the ionized flow from the interface between the H II region and the molecular cloud. The observations show that the level of ionization of the gas does not change dramatically across our sampled region; in particular, the ionic abundance ratio He+/H+ is nearly constant, with He+/H+ = 0.088 +/- 0.006. In the bright innermost region the errors are largely dominated by systematic errors due to uncertainties in the reddening curve for Orion grains and deviations from case B emissivity; statistical errors dominate the error budget in the fainter, outer regions. Photoionization models are computed to determine the correction for the unobserved presence of neutral helium in regions where hydrogen is ionized. We also derive abundances for the heavy elements by comparison with the photoionization model calculations. Emergent continua from newly recomputed Kurucz LTE stellar atmospheres are used as input to the models. The calculations also include a number of important effects of grains on the ionization and thermal structure of the nebula; heating and cooling of the gas by photoemission-recombination from charged grains are found to be substantial. These models reproduce quite well the observed emission-like spectrum, as well as the mid-infrared continuum from the Trapezium region, and show that the correction for neutral helium is small. Our final helium abundance, He/H = 0.088 +/- 0.006, is lower than the commonly quoted value because the correction for neutral helium is much smaller than that used in previous work. By comparing our Orion results with solar, stellar, and nebular measurements of helium and heavy-element enrichments, and with the theoretical Y(p) from primordial nucleosynthesis, we find that all of the data are consistent with a single line in the Y-Z plane. This is a provocative result for studies of galactic and primordial nucleosynthesis. C1 OHIO STATE UNIV,DEPT ASTRON,COLUMBUS,OH 43210. UNIV COLORADO,NATL INST STAND & TECHNOL,JOINT INST LAB ASTROPHYS,BOULDER,CO 80302. UNIV TORONTO,CANADIAN INST THEORET ASTROPHYS,TORONTO M5S 1A1,ONTARIO,CANADA. OI Ferland, Gary/0000-0003-4503-6333 NR 113 TC 352 Z9 352 U1 0 U2 3 PU UNIV CHICAGO PRESS PI CHICAGO PA 5720 S WOODLAWN AVE, CHICAGO, IL 60637 SN 0004-637X J9 ASTROPHYS J JI Astrophys. J. PD JUN 20 PY 1991 VL 374 IS 2 BP 580 EP 609 DI 10.1086/170146 PN 1 PG 30 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA FR742 UT WOS:A1991FR74200016 ER PT J AU WILLIAMS, PA DAY, GW ROSE, AH AF WILLIAMS, PA DAY, GW ROSE, AH TI COMPENSATION FOR TEMPERATURE-DEPENDENCE OF FARADAY-EFFECT IN DIAMAGNETIC MATERIALS - APPLICATION TO OPTICAL FIBER SENSORS SO ELECTRONICS LETTERS LA English DT Article DE FARADAY EFFECT; OPTICAL FIBERS; MAGNETISM AB The temperature dependence of the Faraday effect in a diamagnetic material can be compensated for by varying the polarisation state of the light entering the material as a function of temperature. We demonstrate that this can be done automatically by exploiting the temperature dependence of a linear retarder (waveplate). C1 UNIV COLORADO,DEPT PHYS,CONDENSED MATTER LAB,BOULDER,CO 80309. RP WILLIAMS, PA (reprint author), NATL INST STAND & TECHNOL,BOULDER,CO 80303, USA. NR 3 TC 8 Z9 9 U1 0 U2 2 PU IEE-INST ELEC ENG PI HERTFORD PA MICHAEL FARADAY HOUSE SIX HILLS WAY STEVENAGE, HERTFORD, ENGLAND SG1 2AY SN 0013-5194 J9 ELECTRON LETT JI Electron. Lett. PD JUN 20 PY 1991 VL 27 IS 13 BP 1131 EP 1132 DI 10.1049/el:19910706 PG 2 WC Engineering, Electrical & Electronic SC Engineering GA FU589 UT WOS:A1991FU58900013 ER PT J AU MCKEEN, SA HSIE, EY TRAINER, M TALLAMRAJU, R LIU, SC AF MCKEEN, SA HSIE, EY TRAINER, M TALLAMRAJU, R LIU, SC TI A REGIONAL MODEL STUDY OF THE OZONE BUDGET IN THE EASTERN UNITED-STATES SO JOURNAL OF GEOPHYSICAL RESEARCH-ATMOSPHERES LA English DT Article ID PLANETARY BOUNDARY-LAYER; PEROXYACETYL NITRATE PAN; SMALL IMPLICIT DIFFUSION; ACID DEPOSITION MODEL; TROPOSPHERIC OZONE; NATURAL HYDROCARBONS; NITROGEN-OXIDES; RURAL-AREAS; CHEMICAL MECHANISM; COLORADO MOUNTAINS AB In order to better understand the photochemical and meteorological processes controlling regional scale air quality problems such as ozone formation, we have developed a three-dimensional Eulerian model and applied this model to a high-pressure period (July 4 to July 7, 1986) over the eastern United States. Meteorological and physical variables from a three-dimensional primitive-equation model are used to drive the transport parameters over a grid with 60 x 60 km2 horizontal resolution, and 15 unequally spaced vertical layers extending from the ground to roughly 15 km. The treatment and incorporation of the dynamic model the transport model. surface deposition, emission of anthropogenic and natural O3 precursors, the chemical mechanism for 35 individual species, solar radiation and the numerical methods are discussed in detail. Model performance is tested by comparing model predicted O3 concentrations with observations from the U.S. Environmental Protection Agency ozone-monitoring network. Although a significant correlation between model and observed O3 is found, systematic discrepancies also exist and are discussed in relation to the basic model formulation, and variability in the observed O3. Additionally, a comparison of time-averaged NO(x) and anthropogenic nonmethane hydrocarbon (NMHC) concentrations to relatively long term observations provides a qualitative assessment of the model's ability to simulate certain aspects of these O3 precursors from the few available observations. The model is used as a diagnostic tool to analyze various aspects of regional scale O3 formation and the budgets of the primary O3 precursors. Ozone formation over much of the continental model domain is shown to be NO(x) limited. On the other hand, for midday NO(x) levels greater than about 4 or 5 ppbv, O3 formation is generally suppressed because of the low NMHC to NO(x) ratios (1 to 7) that are characteristic of the emissions inventory. Regional-scale budget analyses show that very little NO(x) or NMHC is transported to the free troposphere for the high-pressure conditions of this study and in the absence of a significant subgrid-scale vertical mixing process (i.e, efficient cumulus transport). We calculate a net turnover time of about 1.5 days for continental O3 below 1800 m with in situ photochemical formation being balanced by photochemical loss and transport off the American continent. The results of this work are intended to serve as a baseline for further model development. C1 UNIV COLORADO, NOAA, COOPERAT INST RES ENVIRONM SCI, BOULDER, CO 80309 USA. RP MCKEEN, SA (reprint author), NOAA, ENVIRONM RES LABS, AERON LAB, 325 BROADWAY, BOULDER, CO 80303 USA. RI Trainer, Michael/H-5168-2013; McKeen, Stuart/H-9516-2013; Hsie, Eirh-Yu/I-4449-2013 OI Hsie, Eirh-Yu/0000-0003-3934-9923 NR 118 TC 111 Z9 117 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 JUN 20 PY 1991 VL 96 IS D6 BP 10809 EP 10845 DI 10.1029/91JD00052 PG 37 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA FV278 UT WOS:A1991FV27800003 ER PT J AU PEIXOTO, JP OORT, AH DEALMEIDA, M TOME, A AF PEIXOTO, JP OORT, AH DEALMEIDA, M TOME, A TI ENTROPY BUDGET OF THE ATMOSPHERE SO JOURNAL OF GEOPHYSICAL RESEARCH-ATMOSPHERES LA English DT Article ID THERMODYNAMICS; CLIMATE; ENERGY AB The balance equations for the entropy in the atmosphere are presented and discussed. Using observed energy fluxes and atmospheric temperatures, we present estimates of the various terms in the global mean entropy budget. The largest boundary fluxes of entropy are associated with the emission of longwave radiation. The fluxes of entropy associated with turbulent and molecular diffusion are found to be much smaller. On the planetary scale the mean outgoing flux of entropy at the top of the atmosphere is found to be about 22 times larger than the mean incoming flux of entropy through solar radiation. The rates of entropy production and destruction by the various irreversible processes that occur in the atmosphere are also computed. The entropy production terms involved in the release of latent heat and the absorption of solar radiation are, by far, the largest sources of entropy for the atmosphere, whereas the production of entropy associated with the absorption of longwave radiation is an order of magnitude smaller. The destruction is mainly accomplished through cooling by outgoing longwave radiation. The contributions of the sensible heat fluxes and friction are relatively small. Regional contributions to the total entropy generation in the atmosphere are studied by considering an equatorial region bounded by two latitudinal walls at 15-degrees-N and 15-degrees-S and a polar region poleward of 70-degrees-N. The rates of entropy generation by the various diabetic processes are highest in the equatorial region; part of the generated entropy is exported to higher latitudes. C1 EUROPEAN CTR MEDIUM RANGE WEATHER FORECASTS, READING RG2 9AX, BERKS, ENGLAND. PRINCETON UNIV, NOAA, GEOPHYS FLUID DYNAM LAB, PRINCETON, NJ 08542 USA. NATL INST GEOPHYS & METEROL, LISBON, PORTUGAL. RP PEIXOTO, JP (reprint author), UNIV LISBON, FAC CIENCIAS, INST GEOFIS, RUA ESCOLA POLITECN 58, P-1200 LISBON, PORTUGAL. RI Tome, Antonio/A-5681-2013 OI Tome, Antonio/0000-0001-9144-7120 NR 23 TC 70 Z9 74 U1 0 U2 8 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 JUN 20 PY 1991 VL 96 IS D6 BP 10981 EP 10988 DI 10.1029/91JD00721 PG 8 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA FV278 UT WOS:A1991FV27800015 ER PT J AU COLLETTE, BB SMITH, DG BOHLKE, EB AF COLLETTE, BB SMITH, DG BOHLKE, EB TI GYMNOTHORAX-PARINI, A NEW SPECIES OF MORAY EEL (TELEOSTEI, MURAENIDAE) FROM WALTERS SHOALS, MADAGASCAR RIDGE SO PROCEEDINGS OF THE BIOLOGICAL SOCIETY OF WASHINGTON LA English DT Article AB Gymnothorax parini is described from 19 specimens collected in shallow water (18 m) at Walters Shoals in the southwestern Indian Ocean. It is distinctive in having a wide bright white margin on the dorsal, caudal, and anal fins; a long anterior nostril tube that reaches or passes the edge of the upper lip when depressed ventrally, and at least half the posterior nostril located anterior to the anterior margin of the eye. It resembles several other species found around islands in the subtropical zone of the southern Indo-Pacific, but differs from all of them in color pattern, number of vertebrae (143-152), and position of the posterior nostril. RP COLLETTE, BB (reprint author), NATL MUSEUM NAT HIST,NATL MARINE FISHERIES SERV,SYSTEMAT LAB,WASHINGTON,DC 20560, USA. NR 0 TC 3 Z9 3 U1 0 U2 1 PU BIOL SOC WASHINGTON PI WASHINGTON PA NAT MUSEUM NAT HIST SMITHSONIAN INST, WASHINGTON, DC 20560 SN 0006-324X J9 P BIOL SOC WASH JI Proc. Biol. Soc. Wash. PD JUN 18 PY 1991 VL 104 IS 2 BP 344 EP 350 PG 7 WC Biology SC Life Sciences & Biomedicine - Other Topics GA FT320 UT WOS:A1991FT32000016 ER PT J AU STILES, MD HAMANN, DR AF STILES, MD HAMANN, DR TI THEORY OF BALLISTIC-ELECTRON-EMISSION SPECTROSCOPY OF NISI2/SI(111) INTERFACES SO PHYSICAL REVIEW LETTERS LA English DT Article ID NISI2-SI(111) INTERFACE; ATOMIC-STRUCTURE; TRANSMISSION; MICROSCOPY AB We discuss theoretical calculations of ballistic-electron-emission-microscopy spectra based in part on a first-principles computation of the transmission across the interfaces. We propose a way of presenting experimental data that highlights the transmission process with respect to contributions from the tunneling distribution. We present a specific application to A- and B-type NiSi2/Si(111) interfaces showing a factor three difference between them at low voltages. C1 AT&T BELL LABS,MURRAY HILL,NJ 07974. RP STILES, MD (reprint author), NATL INST STAND & TECHNOL,GAITHERSBURG,MD 20899, USA. RI Stiles, Mark/K-2426-2012 OI Stiles, Mark/0000-0001-8238-4156 NR 20 TC 45 Z9 45 U1 1 U2 1 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 0031-9007 J9 PHYS REV LETT JI Phys. Rev. Lett. PD JUN 17 PY 1991 VL 66 IS 24 BP 3179 EP 3182 DI 10.1103/PhysRevLett.66.3179 PG 4 WC Physics, Multidisciplinary SC Physics GA FR051 UT WOS:A1991FR05100024 ER PT J AU GARCIAMARIN, JL JORDE, PE RYMAN, N UTTER, F PLA, C AF GARCIAMARIN, JL JORDE, PE RYMAN, N UTTER, F PLA, C TI MANAGEMENT IMPLICATIONS OF GENETIC DIFFERENTIATION BETWEEN NATIVE AND HATCHERY POPULATIONS OF BROWN TROUT (SALMO-TRUTTA) IN SPAIN SO AQUACULTURE LA English DT Article ID SYMPATRIC POPULATIONS; IDENTIFICATION; CONSERVATION; DIVERSITY; STOCKS AB Isozyme electrophoresis was used to assess the amount and distribution of genetic variation among natural populations and hatchery stocks of brown trout (Salmo trutta) in Spain. Genetic variation was found at 19 out of 50 protein coding loci. The hatchery stocks were conspicuously different from the natural populations, and the two groups appeared to represent distinctly divergent evolutionary lineages of brown trout. The hatchery stocks were highly polymorphic but also markedly homogeneous; only 3% of the total genetic variation was explained by stock differences, indicating a common origin for these stocks. In sharp contrast to the hatchery stocks, the natural populations were found to be highly divergent, and more than 60% of their total genetic variability was due to differences between populations. There is evidence indicating impending or actual loss of natural populations by intrusions of fish of hatchery origin or ancestry. In the interest of optimal resource management, we recommend that the indigenous populations of Spain be fully identified and protected, and that the existing hatchery stocks be replaced with local natural populations. C1 UNIV STOCKHOLM,DEPT GENET,S-10691 STOCKHOLM,SWEDEN. NATL MARINE FISHERIES SERV,NW & ALASKA FISHERIES CTR,SEATTLE,WA 98112. RP GARCIAMARIN, JL (reprint author), UNIV AUTONOMA BARCELONA,ESTUDI CIENCIES,EGG,ICTIOL LAB,E-17071 GIRONA,SPAIN. RI Garcia-Marin, Jose-Luis/B-9597-2009; Pla, Carles/L-5765-2014 OI Garcia-Marin, Jose-Luis/0000-0001-9976-5211; Pla, Carles/0000-0002-3749-4740 NR 36 TC 82 Z9 86 U1 0 U2 5 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0044-8486 J9 AQUACULTURE JI Aquaculture PD JUN 15 PY 1991 VL 95 IS 3-4 BP 235 EP 249 DI 10.1016/0044-8486(91)90090-T PG 15 WC Fisheries; Marine & Freshwater Biology SC Fisheries; Marine & Freshwater Biology GA FU449 UT WOS:A1991FU44900005 ER PT J AU HILL, DA AF HILL, DA TI DIFFRACTION BY A HALF-PLANE IN A LOSSY MEDIUM SO JOURNAL OF APPLIED PHYSICS LA English DT Note AB The classical problem of plane-wave diffraction by half-plane is extended to allow for loss in the surrounding medium. The loss causes the arguments of the integral functions to become complex. Numerical results show that the relative importance of the edge-diffracted field decreases as the loss is increased. This effect is important in interpreting the effects of off-path scatterers in remote sensing of lossy media. The results for both electric and magnetic polarizations are in qualitative agreement with previous results based on the Kirchhoff approximation [D. A. Hill, J. Appl. Phys. 69, 1772 (1991)]. RP HILL, DA (reprint author), NATL INST STAND & TECHNOL,DIV ELECTROMAGNET FIELDS,BOULDER,CO 80303, USA. NR 9 TC 0 Z9 0 U1 0 U2 0 PU AMER INST PHYSICS PI WOODBURY PA CIRCULATION FULFILLMENT DIV, 500 SUNNYSIDE BLVD, WOODBURY, NY 11797-2999 SN 0021-8979 J9 J APPL PHYS JI J. Appl. Phys. PD JUN 15 PY 1991 VL 69 IS 12 BP 8405 EP 8407 DI 10.1063/1.347406 PG 3 WC Physics, Applied SC Physics GA FU812 UT WOS:A1991FU81200072 ER PT J AU ROSASCO, GJ BOWERS, WJ HURST, WS LOONEY, JP SMYTH, KC MAY, AD AF ROSASCO, GJ BOWERS, WJ HURST, WS LOONEY, JP SMYTH, KC MAY, AD TI SIMULTANEOUS FORWARD BACKWARD RAMAN-SCATTERING STUDIES OF D2 BROADENED BY D2, HE, AND AR SO JOURNAL OF CHEMICAL PHYSICS LA English DT Article ID SPECTRAL-LINE SHAPES; Q-BRANCH; FUNDAMENTAL-BAND; HIGH-RESOLUTION; IMPACT THEORY; SPECTROSCOPY; DOPPLER; GAIN; H-2; TRANSITION AB Unavoidable beam crossings within a spherical-mirror, multipass stimulated Raman gain cell give rise simultaneously to forward- and backward-scattering Raman signals. In the Doppler-broadened/Dicke-narrowed regime of density, the lineshape is a function of the momentum transfer in the scattering process and thus the observed spectra will have more complex lineshapes than those seen with simple forward or backward scattering geometries. The analyses necessary to quantitatively account for such forward-backward spectra are summarized. These spectra enable unique experimental tests of the lineshape functions used for the description of the Raman Q-branch spectrum under conditions where Doppler contributions and Dicke narrowing are significant. Results for the D2:D2 and D2:He systems support the well-known Galatry, or soft collision, lineshape function. However, in the case of D2:Ar, our results suggest the need to employ the more general, complex soft collision function. In addition, these studies have provided data on linear-with-density line broadening coefficients (previously published) and line shifting coefficients (reported here) for these molecular systems. C1 NATL INST STAND & TECHNOL,DIV THERMOPHYS,GAITHERSBURG,MD 20899. NATL INST STAND & TECHNOL,DIV FIRE MEASUREMENT & RES,GAITHERSBURG,MD 20899. UNIV TORONTO,ONTARIO LASER & LIGHTWAVE RES CTR,DEPT PHYS,TORONTO M5S 1A7,ONTARIO,CANADA. RP ROSASCO, GJ (reprint author), NATL INST STAND & TECHNOL,DIV CHEM PROC METROL,GAITHERSBURG,MD 20899, USA. NR 56 TC 11 Z9 11 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 JUN 15 PY 1991 VL 94 IS 12 BP 7625 EP 7633 DI 10.1063/1.460149 PN 1 PG 9 WC Chemistry, Physical; Physics, Atomic, Molecular & Chemical SC Chemistry; Physics GA FQ584 UT WOS:A1991FQ58400006 ER PT J AU LAUENSTEIN, CP BASTIAN, MJ BIERBAUM, VM PENN, SM LEONE, SR AF LAUENSTEIN, CP BASTIAN, MJ BIERBAUM, VM PENN, SM LEONE, SR TI LASER-INDUCED FLUORESCENCE MEASUREMENTS OF ROTATIONALLY RESOLVED VELOCITY DISTRIBUTIONS FOR CO+ DRIFTED IN HE SO JOURNAL OF CHEMICAL PHYSICS LA English DT Article ID GASEOUS ION-TRANSPORT; MOLECULAR-IONS; ENERGY-DISTRIBUTIONS; 3-TEMPERATURE THEORY; SPEED DISTRIBUTIONS; RARE-GASES; MOBILITY; TUBE; SPECTROSCOPY; DIFFUSION AB Measurements of ion-velocity distributions of CO+ in a He buffer gas are presented as a function of an applied electric field. The distributions are obtained by single frequency, laser-induced fluorescence from various initial rotational states with the laser beam propagating parallel and perpendicular to the drift velocity vector. All distributions are well represented by a Maxwellian for the observed E/N range of 0-13 Td. The reduced mobilities, calculated from the shift of the mean velocity as a function of electric field, increase from 18.7 +/- 1.0 cm2 V-1 s-1 at very low fields to 26.4 +/- 0.7 cm2 V-1 s-1 at 13 Td. From the width of the Doppler profiles, translational "temperatures" are calculated, which are compared to simple attractive and repulsive Maxwell models as a function of the field. The measured values disagree with the predictions, which are well established for atomic ion systems. The differences are discussed in terms of rotationally inelastic energy transfer in the collisions, which is predicted by kinetic theory models. This argument is strengthened by the fact that even though the rotational states rapidly equilibrate, measurements on different lines yield higher temperatures for higher rotational levels. Finally, the small influence of selective quenching of the electronically excited CO+ on the Doppler profiles is demonstrated by measuring effective lifetimes as a function of the applied drift field. C1 UNIV COLORADO,DEPT PHYS,BOULDER,CO 80309. UNIV COLORADO,DEPT CHEM & BIOCHEM,BOULDER,CO 80309. UNIV COLORADO,NATL INST STAND & TECHNOL,BOULDER,CO 80309. RP LAUENSTEIN, CP (reprint author), UNIV COLORADO,JOINT INST LAB ASTROPHYS,BOULDER,CO 80309, USA. NR 37 TC 18 Z9 18 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 JUN 15 PY 1991 VL 94 IS 12 BP 7810 EP 7818 DI 10.1063/1.460167 PN 1 PG 9 WC Chemistry, Physical; Physics, Atomic, Molecular & Chemical SC Chemistry; Physics GA FQ584 UT WOS:A1991FQ58400025 ER PT J AU BUNTIN, SA CAVANAGH, RR RICHTER, LJ KING, DS AF BUNTIN, SA CAVANAGH, RR RICHTER, LJ KING, DS TI PHOTODISSOCIATION DYNAMICS OF MO(CO)6 AT 266-NM AND 355-NM - CO PHOTOFRAGMENT KINETIC-ENERGY AND INTERNAL-STATE DISTRIBUTIONS SO JOURNAL OF CHEMICAL PHYSICS LA English DT Article ID BOND-DISSOCIATION ENERGIES; EXCIMER LASER PHOTOLYSIS; GAS-PHASE; RESOLVED PHOTOFRAGMENTATION; UNIMOLECULAR REACTIONS; INFRARED-SPECTROSCOPY; CHROMIUM HEXACARBONYL; INDUCED FLUORESCENCE; THEORETICAL ASPECTS; METAL-CARBONYLS AB The internal-state and kinetic-energy distributions of the CO photofragments from the 266 and 355 nm photolysis of Mo(CO)6 have been measured under collision-free conditions using vacuum-ultraviolet laser-induced fluorescence. The rotational-state distributions for CO(v" = 0) and (v" = 1) are well represented by Boltzmann distributions with effective rotational "temperatures" of T(r)(v" = 0) = 950 +/- 70 K and T(r)(v" = 1) = 935 +/- 85 K for 266 nm and T(r)(v" = 0) = 750 +/- 70 K and T(r)(v" = 1) = 1150 +/- 250 K for 355 nm photolysis. The CO(v" = 1/v" = 0) vibrational-state ratios for 266 and 355 nm photolysis are 0.19 +/- 0.03 and 0.09 +/- 0.02, respectively. The Doppler-broadened CO photofragment line shapes indicate that the translational energy distributions are isotropic and Maxwellian. There is no photolysis-laser wavelength or internal-state dependence to the extracted translational "temperatures." The observed energy partitioning and kinetic-energy distributions are inconsistent with an impulsive ejection of a single CO ligand. CO photofragment line shapes for 266 nm photolysis are not consistent with a mechanism involving the repulsive ejection of the first CO ligand, followed by the statistical decomposition of the Mo(CO)5 fragment. While phase-space theories do not predict quantitatively the energy disposal, the photodissociation mechanism appears to be dominated by statistical considerations. The results also suggest that the photodissociation of Mo(CO)6 at 266 and 355 nm involves a common initial "state" and that similar exit channel effects are operative. C1 NATL INST STAND & TECHNOL,DIV MOLEC PHYS,GAITHERSBURG,MD 20899. RP BUNTIN, SA (reprint author), NATL INST STAND & TECHNOL,DIV SURFACE SCI,GAITHERSBURG,MD 20899, USA. RI Richter, Lee/N-7730-2016 OI Richter, Lee/0000-0002-9433-3724 NR 57 TC 23 Z9 23 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 JUN 15 PY 1991 VL 94 IS 12 BP 7937 EP 7950 DI 10.1063/1.460128 PN 1 PG 14 WC Chemistry, Physical; Physics, Atomic, Molecular & Chemical SC Chemistry; Physics GA FQ584 UT WOS:A1991FQ58400037 ER PT J AU HAYES, SP CHANG, P MCPHADEN, MJ AF HAYES, SP CHANG, P MCPHADEN, MJ TI VARIABILITY OF THE SEA-SURFACE TEMPERATURE IN THE EASTERN EQUATORIAL PACIFIC DURING 1986-1988 SO JOURNAL OF GEOPHYSICAL RESEARCH-OCEANS LA English DT Article ID TROPICAL PACIFIC; EL-NINO; OCEAN CIRCULATION; HEAT-BUDGET; WIND; SIMULATION; MODELS; FLUXES AB Time series of surface wind and upper ocean temperature and velocity, obtained from equatorial moorings along 110-degrees-W, are used to assess the importance of various oceanic and atmospheric processes in the variation of the mixed layer temperature for the period January 1986 to June 1988. This period coincides with the onset and development of the 1986-1987 El Nino-Southern Oscillation warm event and a subsequent cold event in 1988. Results of the temperature equation analyses indicate that seasonal and interannual variability of sea surface temperature (SST) in the eastern Pacific cannot be accounted for by observed surface heat flux; oceanic processes play an important role in the heating of the surface water. Although no single process dominated SST change, the most important processes in the mean balance were the net incoming surface heat flux, the penetrative solar radiation, and the vertical turbulent flux out the bottom of the mixed layer. The mean vertical entrainment could not be estimated with the available data. On the seasonal time scales, both the vertical turbulent heat flux and the vertical entrainment variations were well correlated with SST change. Zonal advection was a significant contribution to the heat flux variability, but its fluctuations were poorly correlated with the mixed layer heating. In particular, it was found that zonal advective heat flux tended to be out of phase with the spring warming. At higher frequencies, little zonal advective heat was found to be associated with the passage of a Kelvin event in January 1987. Surprisingly, meridional heat advection appeared more important than the zonal heat advection in modifying the local SST as this event passed the mooring location. C1 UNIV WASHINGTON,JOINT INST STUDY ATMOSPHERE & OCEAN,DEPT ATMOSPHER SCI,SEATTLE,WA 98195. TEXAS A&M UNIV SYST,DEPT OCEANOG,COLLEGE STN,TX 77843. RP HAYES, SP (reprint author), NOAA,PACIFIC MARINE ENVIRONM LAB,7600 SAND POINT WAY NE,SEATTLE,WA 98115, USA. RI Chang, Ping /A-1642-2013; McPhaden, Michael/D-9799-2016 OI Chang, Ping /0000-0002-9085-0759; NR 46 TC 79 Z9 81 U1 1 U2 4 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 SN 0148-0227 J9 J GEOPHYS RES-OCEANS JI J. Geophys. Res.-Oceans PD JUN 15 PY 1991 VL 96 IS C6 BP 10553 EP 10566 DI 10.1029/91JC00942 PG 14 WC Oceanography SC Oceanography GA FT343 UT WOS:A1991FT34300010 ER PT J AU EDSON, JB FAIRALL, CW MESTAYER, PG LARSEN, SE AF EDSON, JB FAIRALL, CW MESTAYER, PG LARSEN, SE TI A STUDY OF THE INERTIAL-DISSIPATION METHOD FOR COMPUTING AIR-SEA FLUXES SO JOURNAL OF GEOPHYSICAL RESEARCH-OCEANS LA English DT Article ID ATMOSPHERIC SURFACE-LAYER; CONVECTIVE BOUNDARY-LAYER; INDEX-STRUCTURE PARAMETER; TURBULENT KINETIC-ENERGY; KANSAS MAST INFLUENCE; REFRACTIVE-INDEX; GRADIENT RELATIONSHIPS; HUMIDITY FLUCTUATIONS; PROFILE RELATIONSHIPS; KOLMOGOROV CONSTANTS AB The inertial-dissipation method has long been used to estimate air-sea fluxes from ships because it does not require correction for ship motion. A detailed comparison of the inertial-dissipation fluxes with the direct covariance method is given, using data from the Humidity Exchange Over the Sea (HEXOS) main experiment, HEXMAX. In this experiment, inertial-dissipation packages were deployed at the end of a 17 m boom, in a region relatively free of flow distortion; and on a mast 7 m above the platform (26 m above the sea surface) in a region of considerable flow distortion. An error analysis of the inertial-dissipation method indicates that stress is most accurately measured in near-neutral conditions, whereas scalar fluxes are most accurately measured in near-neutral and unstable conditions. It is also shown that the inertial-dissipation stress estimates are much less affected by the flow distortion caused by the platform as well as by the boom itself. The inertial-dissipation (boom and mast) and boom covariance estimates of stress agree within +/- 20%. The latent heat flux estimates agree within approximately +/- 45%. The sensible heat flux estimates agree within +/- 26% after correction for velocity contamination of the sonic temperature spectra. The larger uncertainty in the latent heat fluxes is due to poor performance of our Lyman-alpha hygrometers in the sea spray environment. Improved parameterizations for the stability dependence of the dimensionless humidity and temperature structure functions are given. These functions are used to find a best fit for effective Kolmogorov constants of 0.55 for velocity (assuming a balance of production and dissipation of turbulent kinetic energy) and 0.79 for temperature and humidity. A Kolmogorov constant of 0.51 implies a production-dissipation imbalance of approximately 12% in unstable conditions. C1 ECOLE NATL SUPER MECAN, MECAN TRANSFERTS TURBULENTS & DISPHAS LAB, F-44072 NANTES, FRANCE. NOAA, ENVIRONM SERV, WAVE PROPAGAT LAB, BOULDER, CO 80303 USA. RISO NATL LAB, DEPT METEOROL & WIND ENERGY, DK-4000 ROSKILDE, DENMARK. RP WOODS HOLE OCEANOG INST, WOODS HOLE, MA 02543 USA. NR 65 TC 87 Z9 88 U1 0 U2 9 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 2169-9275 EI 2169-9291 J9 J GEOPHYS RES-OCEANS JI J. Geophys. Res.-Oceans PD JUN 15 PY 1991 VL 96 IS C6 BP 10689 EP 10711 DI 10.1029/91JC00886 PG 23 WC Oceanography SC Oceanography GA FT343 UT WOS:A1991FT34300020 ER PT J AU WANG, PS HSU, SM MALGHAN, SG WITTBERG, TN AF WANG, PS HSU, SM MALGHAN, SG WITTBERG, TN TI SURFACE OXIDATION-KINETICS OF SI3N4-4-PERCENT-Y2O3 POWDERS STUDIED BY BREMSSTRAHLUNG-EXCITED AUGER-SPECTROSCOPY SO JOURNAL OF MATERIALS SCIENCE LA English DT Article ID SILICON-NITRIDE AB Samples of silicon nitride powder containing 4.0% Y2O3 in weight were heated in air at temperatures between 900 and 1000-degrees-C. The average SiO2 layer thickness on the Si3N4 powder particles, as a function of time at a particular temperature, was measured by Bremsstrahlung-excited Auger electron spectroscopy. Oxidation was found to follow a linear rate law with an activation energy of 56 +/- 1.5 kcal mol-1. The yttrium level measured by X-ray photoelectron spectroscopy was also found to decrease as a function of the oxide layer thickness. This suggests that there is a reaction between the Si3N4 and Y2O3 particles which results in the formation of an yttrium-rich phase at the interface between the surface SiO2 layer and the underlying Si3N4 particle. C1 UNIV DAYTON,RES INST,DAYTON,OH 45469. RP WANG, PS (reprint author), NATL INST STAND & TECHNOL,DIV CERAM,GAITHERSBURG,MD 20899, USA. NR 10 TC 12 Z9 12 U1 0 U2 1 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 JUN 15 PY 1991 VL 26 IS 12 BP 3249 EP 3252 DI 10.1007/BF01124669 PG 4 WC Materials Science, Multidisciplinary SC Materials Science GA FT510 UT WOS:A1991FT51000016 ER PT J AU KURIYAMA, M AF KURIYAMA, M TI MATERIALS SCIENCE WITH SR USING X-RAY-IMAGING SPATIAL-RESOLUTION SOURCE SIZE SO NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH SECTION A-ACCELERATORS SPECTROMETERS DETECTORS AND ASSOCIATED EQUIPMENT LA English DT Article; Proceedings Paper CT INTERNATIONAL SYMP ON X-RAY SYNCHROTRON RADIATION AND ADVANCED SCIENCE AND TECHNOLOGY CY FEB 15-16, 1990 CL KOBE, JAPAN SP INST PHYS & CHEM RES, JAPAN ATOM ENERGY RES INST ID MONOCHROMATIC SYNCHROTRON RADIATION; CRYSTAL-GROWTH; DIFFRACTION; MICRORADIOGRAPHY; TOPOGRAPHY; MAGNIFIER AB Some examples of applications of synchrotron radiation to materials science demonstrate the importance of obtaining microstructure information within structural as well as functional materials in order to control their properties and quality as designed for industrial purposes. To collect such information, X-ray imaging in quasi real time (50-100 s time intervals) is required in either the microradiographic mode or the diffraction (in transmission) mode. New measurement technologies based on imaging are applied to polycrystalline materials, single crystal materials and multilayered device materials to illustrate what kind of synchrotron radiation facility is most desirable for materials science and engineering. C1 NATL INST STAND & TECHNOL,MAT SCI & ENGN LAB,GAITHERSBURG,MD 20899. NR 15 TC 0 Z9 0 U1 1 U2 1 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0168-9002 J9 NUCL INSTRUM METH A JI Nucl. Instrum. Methods Phys. Res. Sect. A-Accel. Spectrom. Dect. Assoc. Equip. PD JUN 15 PY 1991 VL 303 IS 3 BP 503 EP 514 DI 10.1016/0168-9002(91)90287-Z PG 12 WC Instruments & Instrumentation; Nuclear Science & Technology; Physics, Nuclear; Physics, Particles & Fields SC Instruments & Instrumentation; Nuclear Science & Technology; Physics GA FU288 UT WOS:A1991FU28800012 ER PT J AU LEDBETTER, H LEI, M AF LEDBETTER, H LEI, M TI ESTIMATED DTC/DP AND DTC/D-SIGMA-IJ FOR THE Y1BA2CU3O7 SUPERCONDUCTOR SO PHYSICA C LA English DT Article ID HIGH-TC SUPERCONDUCTORS; TRANSITION-TEMPERATURE; OXIDE SUPERCONDUCTORS; STRESS DEPENDENCE; APICAL OXYGEN; PRESSURE; YBA2CU3O7-X; STATE; GPA AB For Y1Ba2Cu3O7, we estimated the critical-temperature pressure derivative dT(c)/dP and the three principal uniaxial compressive-stress derivatives dT(c)/d-sigma-a, dT(c)/d-sigma-b, dT(c)/d-sigma-c. These estimates are useful because the measured values, especially dT(c)/d-sigma-ij, show such strong disagreement. To estimate these thermodynamic quantities, we extended a model of Ohta and coworkers that relates T(c) to DELTA-V(A), the difference in Madelung energy at the two oxygen sites, apical and planar. We found that dT(c)/dP is positive, but small: 0.09 K/GPa. For uniaxial-stress, we found that dT(c)/d-sigma-c equals approximately dT(c)/d-sigma-c: 0.09 K/GPa. Thus, uniaxial compression along the c-axis (bringing together the CuO2 planes) produces no remarkable change in T(c). We found a negative dT(c)/d-sigma-b: -0.06 K/GPa. This negative value agrees with results derived by Millis and Rabe, and it agrees with T(c) increasing with an increasing b unit-cell dimension. Plane compressive stress in the a-c plane produces the largest effect: 0.17 K/GPa, twice that for hydrostatic compression. RP LEDBETTER, H (reprint author), NATL INST STAND & TECHNOL,MAT SCI & ENGN LAB,BOULDER,CO 80303, USA. NR 27 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 JUN 15 PY 1991 VL 177 IS 1-3 BP 86 EP 88 DI 10.1016/0921-4534(91)90301-E PG 3 WC Physics, Applied SC Physics GA FV360 UT WOS:A1991FV36000014 ER PT J AU GARBOCZI, EJ THORPE, MF DEVRIES, MS DAY, AR AF GARBOCZI, EJ THORPE, MF DEVRIES, MS DAY, AR TI UNIVERSAL CONDUCTIVITY CURVE FOR A PLANE CONTAINING RANDOM HOLES SO PHYSICAL REVIEW A LA English DT Article ID CARLO RENORMALIZATION-GROUP; CONTINUUM PERCOLATION; CRITICAL-BEHAVIOR; EXCLUDED-VOLUME; 2 DIMENSIONS; TRANSPORT AB This paper examines the general percolation problem of cutting randomly centered insulating holes in a two-dimensional conducting sheet, and explores how the electrical conductivity-sigma decreases with the remaining area fraction. This problem has been studied in the past for circular, square, and needlelike holes, using both computer simulations and analog experiments. In this paper, we extend these studies by examining cases where the insulating hole is of arbitrary shape, using digital-image-based numerical techniques in conjunction with the Y-del algorithm. We find that, within computational uncertainty, the scaled percolation threshold, x(c) = n(c) = 5.9 +/- 0.4, is a universal quantity for all the cases studied, where n(c) is the critical value at percolation of the number of holes per unit area n, and is a measure of n(I)-1, the initial slope of the sigma(n) curve, calculated in the few-hole limit and averaged over the different shapes and sizes of the holes used. For elliptical holes, L(eff) = 2(a + b), where a and b are the semimajor and semiminor axes, respectively. All results are well described by the universal conductivity curve: sigma/sigma-0 = [(1 - x/5.90)(1 + x/5.90 - x2/24.97)(1 + x/3.31)-1]1.3, where x = nL(eff)2, and sigma-0 is the conductivity of the sheet before any holes are introduced. C1 MICHIGAN STATE UNIV,DEPT PHYS & ASTRON,E LANSING,MI 48824. MARQUETTE UNIV,DEPT NURSING,MILWAUKEE,WI 53233. RP GARBOCZI, EJ (reprint author), NATL INST STAND & TECHNOL,DIV BLDG MAT,226-B348,GAITHERSBURG,MD 20899, USA. NR 26 TC 59 Z9 59 U1 1 U2 2 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 1050-2947 J9 PHYS REV A JI Phys. Rev. A PD JUN 15 PY 1991 VL 43 IS 12 BP 6473 EP 6482 DI 10.1103/PhysRevA.43.6473 PG 10 WC Optics; Physics, Atomic, Molecular & Chemical SC Optics; Physics GA FU846 UT WOS:A1991FU84600001 ER PT J AU VANBRUNT, RJ CERNYAR, EW AF VANBRUNT, RJ CERNYAR, EW TI INFLUENCE OF MEMORY PROPAGATION ON PHASE-RESOLVED STOCHASTIC-BEHAVIOR OF AC-GENERATED PARTIAL DISCHARGES SO APPLIED PHYSICS LETTERS LA English DT Article ID COMPUTER; CORONA AB Using measurements of phase-restricted conditional partial-discharge pulse-amplitude and phase distributions, it is shown for the first time that the stochastic properties of a dielectric-barrier type of partial discharge generated by an ac voltage are significantly influenced by memory associated with charge deposited on the dielectric surface by preceding discharge events. This memory effect must be considered in any attempt to interpret results of phase-resolved partial-discharge measurements. RP VANBRUNT, RJ (reprint author), NATL INST STANDARDS & TECHNOL,GAITHERSBURG,MD 20899, USA. NR 13 TC 17 Z9 18 U1 0 U2 1 PU AMER INST PHYSICS PI WOODBURY PA CIRCULATION FULFILLMENT DIV, 500 SUNNYSIDE BLVD, WOODBURY, NY 11797-2999 SN 0003-6951 J9 APPL PHYS LETT JI Appl. Phys. Lett. PD JUN 10 PY 1991 VL 58 IS 23 BP 2628 EP 2630 DI 10.1063/1.104815 PG 3 WC Physics, Applied SC Physics GA FP869 UT WOS:A1991FP86900016 ER PT J AU STOCKE, JT CASE, J DONAHUE, M SHULL, JM SNOW, TP AF STOCKE, JT CASE, J DONAHUE, M SHULL, JM SNOW, TP TI NEW OBSERVATIONS OF THE GAS CLOUD ASSOCIATED WITH THE QUASAR-GALAXY PAIR 3C-232 NGC-3067 SO ASTROPHYSICAL JOURNAL LA English DT Article DE GALAXIES, INDIVIDUAL (NGC-3067); GALAXIES, INTERACTIONS; INTERSTELLAR, MATTER; QUASARS; ULTRAVIOLET, SPECTRA ID CA-II ABSORPTION; INTERSTELLAR NA-I; NEUTRAL HYDROGEN; INTERGALACTIC RING; CROSS-SECTIONS; M96 GROUP; LINES; SPECTRUM; DEPENDENCE; ORIGIN AB We present new optical Na I and Ca II spectra, new H-alpha images, and archival IUE ultraviolet spectra of the quasar-galaxy pair 3C 232/NGC 3067, to study the H I gas cloud seen in 21 cm emission between the eastern edge of NGC 3067 and 3C 232. High-resolution optical spectra show two, and possibly three, absorption systems in Ca II and Na I, with a large velocity spread (DELTA-upsilon almost-equal-to 160 km s-1); IUE spectra show Fe II and Mg II absorption. The strongest system is coincident with narrow 21 cm absorption at cz = 1420 km s-1 and has Na I/Ca II almost-equal-to 0.7-2, suggesting that the Ca-bearing grains have not been strongly distributed. The H I absorption is most likely produced by cold (T less-than-or-equal-to 300 K) gas comprising 1%-2% of the 3 x 10(21) cm-2 of warm H I (T almost-equal-to 8000 K) seen in 21 cm emission. At a distance of (14.7 Mpc)h-1, this cloud has mass approximately (10(8) M.)h-2, linear extent approximately (2.5 kpc)h-1, and mean hydrogen density n(H) = (0.42 cm-3)h. We detect no H-alpha, to a limit of 27.5 mag arcsec-2, coincident with the H I cloud in broad-band R images or in narrow-band redshifted CCD images. The absence of H-alpha sets a limit of PHI-ion < 8.35 x 10(4) photons s-1 on the ionizing photon flux, corresponding to I0 = I-nu(13.6 eV) < 1.8 x 10(-22) ergs cm-2 s-1 Hz-1 sr-1 on the diffuse extragalactic ionizing flux. The ionization balance of Na I and Ca II can provide even lower limits, I0 almost-equal-to [(1-6) x 10(-23) ergs cm-2 s-1 Hz-1 sr-1]h, assuming depletion factors d(Na) = 0.25 and d(Ca) = 0.1 for Na and Ca. From the flux of ionizing photons inferred from IUE spectra of 3C 232, the H-alpha limit implies that the quasar must lie at least (25 kpc)h-1 behind the H I cloud, and the Na-Ca limits imply a distance of at least (25-66 kpc)h-3/2. While this does not rule out the noncosmological redshift interpretation for the quasar, 3C 232 is unlikely to be the perturber that stripped the H I finger from NGC 3067. The H I is most likely a chance projection at the quasar position and offers no additional support for the association of the pair. C1 UNIV COLORADO,NATL INST STAND & TECHNOL,JOINT INST LAB ASTROPHYS,BOULDER,CO 80302. UNIV COLORADO,CTR ASTROPHYS & SPACE ASTRON,BOULDER,CO 80309. RI Donahue, Megan/B-5361-2012 NR 45 TC 37 Z9 37 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 JUN 10 PY 1991 VL 374 IS 1 BP 72 EP 82 DI 10.1086/170097 PN 1 PG 11 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA FP765 UT WOS:A1991FP76500007 ER PT J AU BUR, AJ LOWRY, RE ROTH, SC THOMAS, CL WANG, FW AF BUR, AJ LOWRY, RE ROTH, SC THOMAS, CL WANG, FW TI OBSERVATIONS OF SHEAR-INDUCED MOLECULAR-ORIENTATION IN A POLYMER MELT USING FLUORESCENCE ANISOTROPY MEASUREMENTS SO MACROMOLECULES LA English DT Note ID UNIAXIAL LIQUID-CRYSTALS; POLARIZED FLUORESCENCE; DYNAMICS; DEPOLARIZATION; POLYSTYRENE; EMISSION; CHAINS; DECAY RP BUR, AJ (reprint author), NATL INST STAND & TECHNOL,DIV POLYMERS,GAITHERSBURG,MD 20899, USA. NR 19 TC 13 Z9 13 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 JUN 10 PY 1991 VL 24 IS 12 BP 3715 EP 3717 DI 10.1021/ma00012a040 PG 3 WC Polymer Science SC Polymer Science GA FQ573 UT WOS:A1991FQ57300040 ER PT J AU ASHFOLD, MNR PRINCE, JD AF ASHFOLD, MNR PRINCE, JD TI 3RD HARMONIC-GENERATION IN MOLECULAR GASES SO MOLECULAR PHYSICS LA English DT Article ID MULTI-PHOTON IONIZATION; EXTREME ULTRAVIOLET-RADIATION; MULTIPHOTON IONIZATION; 3RD-HARMONIC GENERATION; VACUUM ULTRAVIOLET; XUV RADIATION; ELECTRONIC-SPECTRA; CARBON-MONOXIDE; HIGH-RESOLUTION; RYDBERG STATES AB We report excitation profiles for producing vacuum ultraviolet radiation via third harmonic generation in a range of molecular gases, including C2H2, C2D2, CS2, H2S, CO, CH3I, CH3Cl, HCl, and BrCN. We also present the results of model calculations which provide a qualitative rationale for the way in which these excitation functions are observed to vary with sample pressure and with laser focusing conditions, and conclude by pinpointing factors which are likely to encourage third harmonic generation in molecular gases. C1 UNIV COLORADO, NATL INST STAND & TECHNOL, JOINT INST LAB ASTROPHYS, BOULDER, CO 80302 USA. RP UNIV BRISTOL, SCH CHEM, BRISTOL BS8 1TS, AVON, ENGLAND. OI ashfold, michael/0000-0001-5762-7048 NR 54 TC 7 Z9 7 U1 0 U2 4 PU TAYLOR & FRANCIS LTD PI ABINGDON PA 2-4 PARK SQUARE, MILTON PARK, ABINGDON OR14 4RN, OXON, ENGLAND SN 0026-8976 EI 1362-3028 J9 MOL PHYS JI Mol. Phys. PD JUN 10 PY 1991 VL 73 IS 2 BP 297 EP 315 DI 10.1080/00268979100101211 PG 19 WC Chemistry, Physical; Physics, Atomic, Molecular & Chemical SC Chemistry; Physics GA FV776 UT WOS:A1991FV77600004 ER PT J AU MEOTNER, M SIECK, LW AF MEOTNER, M SIECK, LW TI PROTON AFFINITY LADDERS FROM VARIABLE-TEMPERATURE EQUILIBRIUM MEASUREMENTS .1. A REEVALUATION OF THE UPPER PROTON AFFINITY RANGE SO JOURNAL OF THE AMERICAN CHEMICAL SOCIETY LA English DT Article ID GAS-PHASE BASICITIES; IONIC HYDROGEN-BOND; THERMAL-DECOMPOSITION; SUBSTITUTED BENZENES; AMMONIUM ION; SOLVATION; WATER; THERMOCHEMISTRY; STABILITIES; ENERGIES AB An interlocking ladder of relative proton affinities of 47 compounds, over a range of 54 kcal/mol, was obtained from the enthalpies of proton-transfer equilibria, by using variable-temperature pulsed high-pressure mass spectrometry. From C3H6 (PA = 179.5 kcal/mol) to i-C4H8 (PA = 195.9 kcal/mol) the results agree well with tabulated values, but for the upper PA range the present values are increased significantly. For example, the present vs literature PA values are NH3, 208.3 vs 204.0; CH3NH2, 219.6 vs 2l4.1; and t-C4H9NH2, 229.2 vs 220.8 kcal/mol. The new value for t-C4H9NH2 is also confirmed by the association thermochemistry of t-C4H9+ with NH3. The entropies of protonation are in reasonable agreement with expected rotational symmetry changes. Aromatics and olefins show a positive entropy of protonation of 3-6 cal/mol K due to structural effects, but no anomalous effects are observed that would indicate a dynamic proton. RP MEOTNER, M (reprint author), NATL INST STAND & TECHNOL,DIV CHEM KINET,GAITHERSBURG,MD 20899, USA. NR 34 TC 156 Z9 156 U1 1 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 JUN 5 PY 1991 VL 113 IS 12 BP 4448 EP 4460 DI 10.1021/ja00012a012 PG 13 WC Chemistry, Multidisciplinary SC Chemistry GA FP844 UT WOS:A1991FP84400012 ER PT J AU BLACK, DR BURDETTE, HE DOBBYN, RC SPAL, RD KURIYAMA, M AF BLACK, DR BURDETTE, HE DOBBYN, RC SPAL, RD KURIYAMA, M TI ADVANCED X-RAY-IMAGING METHODS FOR CERAMICS SO AMERICAN CERAMIC SOCIETY BULLETIN LA English DT Article ID SYNCHROTRON RADIATION; MICRORADIOGRAPHY; TOPOGRAPHY; MAGNIFIER RP BLACK, DR (reprint author), NATL INST STAND & TECHNOL,MAT SCI & ENGN LAB,GAITHERSBURG,MD 20899, USA. NR 14 TC 0 Z9 0 U1 0 U2 0 PU AMER CERAMIC SOC PI WESTERVILLE PA 735 CERAMIC PLACE, PO BOX 6136, WESTERVILLE, OH 43081-6136 SN 0002-7812 J9 AM CERAM SOC BULL JI Am. Ceram. Soc. Bull. PD JUN PY 1991 VL 70 IS 6 BP 1004 EP 1009 PG 6 WC Materials Science, Ceramics SC Materials Science GA FQ167 UT WOS:A1991FQ16700007 ER PT J AU STEINER, B DOBBYN, RC AF STEINER, B DOBBYN, RC TI CRYSTAL REGULARITY WITH HIGH-RESOLUTION SYNCHROTRON X-RADIATION DIFFRACTION IMAGING SO AMERICAN CERAMIC SOCIETY BULLETIN LA English DT Article ID TOPOGRAPHY; GROWTH RP STEINER, B (reprint author), NATL INST STAND & TECHNOL,GAITHERSBURG,MD 20899, USA. NR 8 TC 2 Z9 2 U1 0 U2 0 PU AMER CERAMIC SOC PI WESTERVILLE PA 735 CERAMIC PLACE, PO BOX 6136, WESTERVILLE, OH 43081-6136 SN 0002-7812 J9 AM CERAM SOC BULL JI Am. Ceram. Soc. Bull. PD JUN PY 1991 VL 70 IS 6 BP 1017 EP 1023 PG 7 WC Materials Science, Ceramics SC Materials Science GA FQ167 UT WOS:A1991FQ16700009 ER PT J AU RUMBLE, J AF RUMBLE, J TI THE STANDARD REFERENCE DATABASE SO AMERICAN LABORATORY LA English DT Database Review RP RUMBLE, J (reprint author), NATL INST STAND & TECHNOL,GAITHERSBURG,MD, USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU INT SCIENTIFIC COMMUN INC PI SHELTON PA PO BOX 870, 30 CONTROLS DRIVE, SHELTON, CT 06484-0870 SN 0044-7749 J9 AM LAB JI Am. Lab. PD JUN PY 1991 VL 23 IS 9 BP 54 EP 54 PG 1 WC Chemistry, Analytical; Instruments & Instrumentation SC Chemistry; Instruments & Instrumentation GA FQ340 UT WOS:A1991FQ34000012 ER PT J AU MECHELS, S YOUNG, M AF MECHELS, S YOUNG, M TI VIDEO MICROSCOPE WITH SUBMICROMETER RESOLUTION SO APPLIED OPTICS LA English DT Article ID OPTICAL MICROSCOPE; METROLOGY AB We have constructed and evaluated a video microscope with a 150- x 150-mu-m field of view for performing measurements of optical fiber geometry. The microscope consists of a frame transfer video camera, condensing and filtering optics, a 40X, 0.65 N.A. microscope objective, and frame digitizing electronics. Using simple digital algorithms, we measure distance with a random uncertainty of approximately 40 nm across the full field of view, but width measurements suffer from a systematic error between 0.1 and 0.2-mu-m. RP MECHELS, S (reprint author), NATL INST STAND & TECHNOL,DIV ELECTROMAGNET TECHNOL,325 BROADWAY,BOULDER,CO 80303, USA. NR 24 TC 7 Z9 7 U1 0 U2 0 PU OPTICAL SOC AMER PI WASHINGTON PA 2010 MASSACHUSETTS AVE NW, WASHINGTON, DC 20036 SN 0003-6935 J9 APPL OPTICS JI Appl. Optics PD JUN 1 PY 1991 VL 30 IS 16 BP 2202 EP 2211 PG 10 WC Optics SC Optics GA FP566 UT WOS:A1991FP56600021 PM 20700196 ER PT J AU LOEWENSTEIN, M MATHEWS, WG AF LOEWENSTEIN, M MATHEWS, WG TI HOT GAS METALLICITY AND THE HISTORY OF SUPERNOVA ACTIVITY IN ELLIPTIC GALAXIES SO ASTROPHYSICAL JOURNAL LA English DT Article DE GALAXIES; ABUNDANCES; GALAXIES; INTERSTELLAR MATTER; STARS; SUPERNOVAE ID GALACTIC FLOWS; EVOLUTION AB In the near future, satellite-born X-ray spectrometers will observe equivalent widths of emission lines produced in the hot (T approximately 10(7) K) interstellar medium in individual elliptical galaxies. Abundances in the hot gas are established by stellar mass loss and supernovae. Emission-line measurements will (1) determine or put useful constraints on the stellar metallicity and its variation with galactic radius and (2) allow an evaluation of the supernova rate in these galaxies and its past variation. The time dependence of the Type Ia supernova rate in ellipticals, currently unknown, determines not only the metallicity of the present day interstellar gas, but strongly influences the interstellar gasdynamical history over the Hubble time. Metallicity and gas dynamics are strongly coupled. We describe calculations of the dynamical evolution of the hot interstellar medium in a massive elliptical galaxy assuming a variety of past variations of the supernova rate. The equivalent widths of the 6.7 keV iron line are calculated as a function of redshift and of galactic projected radius. The present-day interstellar gas in elliptical galaxies contains a fossil record of past supernova activity that can be determined from measurements of iron line equivalent widths at several projected radii in the galaxy. C1 NATL INST STAND & TECHNOL,BOULDER,CO 80309. UNIV CALIF SANTA CRUZ,BOARD STUDIES ASTRON & ASTROPHYS,SANTA CRUZ,CA 95064. UNIV CALIF SANTA CRUZ,LICK OBSERV,MT HAMILTON,CA 95140. RP LOEWENSTEIN, M (reprint author), UNIV COLORADO,JOINT INST LAB ASTROPHYS,BOULDER,CO 80309, USA. NR 25 TC 47 Z9 47 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 JUN 1 PY 1991 VL 373 IS 2 BP 445 EP 451 DI 10.1086/170063 PN 1 PG 7 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA FM779 UT WOS:A1991FM77900010 ER PT J AU BROWN, A DRAKE, SA VANSTEENBERG, ME LINSKY, JL AF BROWN, A DRAKE, SA VANSTEENBERG, ME LINSKY, JL TI X-RAY-EMISSION FROM HYBRID-CHROMOSPHERE STARS SO ASTROPHYSICAL JOURNAL LA English DT Article DE STARS; CHROMOSPHERES; STARS; LATE-TYPE; STARS; X-RAYS ID ABSORPTION-LINES; INTERSTELLAR; ULTRAVIOLET; ATMOSPHERES; ABUNDANCE; MODELS; GIANT; ZINC AB The current evidence for the existence of hot (greater-than-or-equal-to 10(6) K) plasma around hybrid-chromosphere stars is examined. EXOSAT observations of the hybrid star alpha TrA provide the first X-ray detection of such a star. An X-ray differential emission measure locus is derived and used to demonstrate that the temperature of the X-ray-emitting plasma is unlikely to be lower than 10(6) K. Estimates are made of the interstellar hydrogen column densities toward hybrid stars using a variety of methods in order to allow interpretation of X-ray observations. The X-ray luminosity of alpha TrA is calculated to be approximately 5 x 10(29) ergs s-1 over the 1-300 angstrom spectral region and 7 x 10(28) ergs s-1 in the Einstein 0.2-4 keV (3-60 angstrom) energy range for N(H) = 5 x 10(19) cm-2 and a temperature of 10(6) K. X-ray nondetections of other hybrid stars from EXOSAT and Einstein satellite observations are consistent with their interstellar hydrogen column densities, if the ratio of their intrinsic X-ray to transition region emission line surface fluxes are the same as for alpha TrA. It now seems that the conceptual model of Linsky, in which the higher temperature plasma is magnetically confined and separated from the outflowing stellar wind, is most likely to correctly represent the physical structuring of hybrid star outer atmospheres. C1 NATL INST STAND & TECHNOLOGY,BOULDER,CO 80309. ST SYST CORP,LANHAM,MD 20706. NASA,GODDARD SPACE FLIGHT CTR,NATL SPACE SCI DATA CTR,GREENBELT,MD 20771. UNIV COLORADO,DIV QUANTUM PHYS,BOULDER,CO 80309. RP BROWN, A (reprint author), UNIV COLORADO,JOINT INST LAB ASTROPHYS,BOULDER,CO 80309, USA. NR 41 TC 21 Z9 21 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 JUN 1 PY 1991 VL 373 IS 2 BP 614 EP 619 DI 10.1086/170080 PN 1 PG 6 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA FM779 UT WOS:A1991FM77900027 ER PT J AU Kopcewicz, B Nagamoto, C Parungo, F Harris, J Miller, J Sievering, H Rosinski, J AF Kopcewicz, B. Nagamoto, C. Parungo, F. Harris, J. Miller, J. Sievering, H. Rosinski, J. TI Morphological studies of sulfate and nitrate particles on the east coast of North America and over the North Atlantic Ocean SO ATMOSPHERIC RESEARCH LA English DT Article AB Shipborne and airborne aerosol samples were collected during the Coordinated-Air-Sea Experiment (CASE) over the western North Atlantic Ocean. The experiment was accompanied by measurements on shore near Hampton, Virginia. Individual particle morphology, size, and concentration were analyzed with an electron microscope. Particles containing sulfuric acid, sulfate, nitric acid, and nitrate were identified with various morphological tests. Temporal and spatial variations of aerosol physicochemical characteristics were studied in relation to atmospheric parameters. A diurnal solar radiation effect on concentration and chemical composition of small sulfate-containing particles (0.2 mu m < d < 0.7 mu m) was observed, indicating that the particles are the product of photochemical reaction. Sulfuric acid particles were most frequently observed near noon, and ammonium sulfate particles were dominant at night. The concentration of sulfate particles also depends on air trajectories, including sources of air mass, wind direction, and wind speed. Meteorological conditions (humidity and solar radiation) influenced the concentrations of nitrate-containing aerosols including nitric acid particles. High concentrations of nitrate particles were found only near the source; sulfate particles could transport to greater distances. For both sulfate particles and nitrate particles, concentrations were higher at low altitudes (< 150 m) than at high altitudes (2600 m). C1 [Kopcewicz, B.; Nagamoto, C.] NOAA, Environm Res Labs, Air Resources Lab, Boulder, CO 80303 USA. [Kopcewicz, B.; Parungo, F.] Polish Acad Sci, Inst Geophys, Warsaw 42, Poland. [Harris, J.] NOAA, Environm Res Labs, Climate Monitoring & Diagnost Lab, Boulder, CO 80303 USA. [Miller, J.] NOAA, Environm Res Labs, Air Resources Lab, Silver Spring, MD USA. [Sievering, H.] Univ Colorado, Denver, CO 80202 USA. [Rosinski, J.] Natl Ctr Atmospher Res, Boulder, CO 80307 USA. RP Kopcewicz, B (reprint author), NOAA, Environm Res Labs, Air Resources Lab, Boulder, CO 80303 USA. NR 23 TC 4 Z9 4 U1 0 U2 2 PU ELSEVIER SCIENCE INC PI NEW YORK PA 360 PARK AVE SOUTH, NEW YORK, NY 10010-1710 USA SN 0169-8095 J9 ATMOS RES JI Atmos. Res. PD JUN PY 1991 VL 26 IS 3 BP 245 EP 271 DI 10.1016/0169-8095(91)90057-4 PG 27 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA V26CT UT WOS:000208524400005 ER PT J AU ASTUMIAN, D BERG, H AF ASTUMIAN, D BERG, H TI DIRECT ELECTRIC-FIELD EFFECTS AND SEQUENTIAL PROCESSES IN BIOSYSTEMS SO BIOELECTROCHEMISTRY AND BIOENERGETICS LA English DT Note ID ELECTROMAGNETIC-FIELDS; CELL-MEMBRANE; BONE-CELLS; INVITRO; STIMULATION; ELECTROSTIMULATION; METABOLISM; RELEASE; ENERGY C1 ACAD SCI GDR,CENT INST MICROBIOL & EXPTL THERAPY,O-6900 JENA,GERMANY. RP ASTUMIAN, D (reprint author), NATL INST STAND & TECHNOL,DIV CHEM PROC METROL,GAITHERSBURG,MD, USA. NR 42 TC 14 Z9 14 U1 0 U2 0 PU ELSEVIER SCIENCE SA LAUSANNE PI LAUSANNE 1 PA PO BOX 564, 1001 LAUSANNE 1, SWITZERLAND SN 0302-4598 J9 BIOELECTROCH BIOENER JI Bioelectrochem. Bioenerg. PD JUN PY 1991 VL 25 IS 3 BP 455 EP 462 DI 10.1016/0302-4598(91)80010-Z PG 8 WC Biochemistry & Molecular Biology; Biophysics SC Biochemistry & Molecular Biology; Biophysics GA FV927 UT WOS:A1991FV92700010 ER PT J AU ENGEL, DW BROUWER, M AF ENGEL, DW BROUWER, M TI SHORT-TERM METALLOTHIONEIN AND COPPER CHANGES IN BLUE CRABS AT ECDYSIS SO BIOLOGICAL BULLETIN LA English DT Article ID CALLINECTES-SAPIDUS; HOMARUS-AMERICANUS; LOBSTER; MOLT AB We have previously demonstrated that the small metal-binding protein, metallothionein (MT), plays an important role in the metabolism of Cu and Zn during the molt cycle of the blue crab, Callinectes sapidus. To further delineate the role of MT in the regulation of both metals, the distribution of copper and zinc was examined immediately after ecdysis in the blue crab. Hemolymph, digestive gland, and stomach were analyzed, by atomic absorption spectrophotometry (AAS), for total metal concentration in crabs at different molt stages, from premolt (D3) through paper shell (B2), and including intermolt (C4). Cytosolic extracts were prepared from digestive glands of individual crabs and analyzed, by gel filtration chromatography and AAS, for MT, copper, and zinc. The short-term changes in metal concentrations in the tissues, and those in MT and metals in the cytosol were dramatic. Transient changes in the metals bound to MT correlated well with the loss of copper from the hemolymph and the digestive gland. The observed changes occurred over a period of 90 min after ecdysis. The data suggest that copper is stripped from hemocyanin in the digestive gland after ecdysis, displacing zinc from MT in the cytosolic pool. We hypothesize that the copper/zinc-MT complex may then be sequestered in lysosomes and eliminated into the gut and out in the feces. A discriptive flow model showing the involvement of MT in copper and zinc partitioning after ecdysis in the blue crab has been constructed. C1 DUKE UNIV,MARINE LAB,CTR MARINE BIOMED,BEAUFORT,NC 28516. RP ENGEL, DW (reprint author), NOAA,NATL MARINE FISHERIES SERV,SE FISHERIES CTR,BEAUFORT LAB,BEAUFORT,NC 28516, USA. NR 9 TC 57 Z9 58 U1 0 U2 2 PU MARINE BIOL LAB PI WOODS HOLE PA BIOLOGICAL BULL MBL STREET, WOODS HOLE, MA 02543 SN 0006-3185 J9 BIOL BULL JI Biol. Bull. PD JUN PY 1991 VL 180 IS 3 BP 447 EP 452 DI 10.2307/1542345 PG 6 WC Biology; Marine & Freshwater Biology SC Life Sciences & Biomedicine - Other Topics; Marine & Freshwater Biology GA FQ685 UT WOS:A1991FQ68500012 ER PT J AU TURNOCK, BJ QUINN, TJ AF TURNOCK, BJ QUINN, TJ TI THE EFFECT OF RESPONSIVE MOVEMENT ON ABUNDANCE ESTIMATION USING LINE TRANSECT SAMPLING SO BIOMETRICS LA English DT Article DE ANIMAL MOVEMENT; DALL PORPOISE; LINE TRANSECT SURVEYS; WEIGHTED DISTRIBUTIONS ID MODELS; DISTRIBUTIONS; POPULATIONS; BIAS AB Line transect estimators of abundance are biased when responsive movement in relation to the transect line occurs. We present and compare two approaches to correct estimators with auxiliary information on movement: a correction factor approach and a decomposition approach. Movement and detection of animals were simulated by computer. The decomposition approach is preferred over the correction factor approach. The methods are illustrated with survey data of Dall's porpoise in the Gulf of Alaska. C1 UNIV ALASKA,JUNEAU CTR FISHERIES & OCEAN SCI,JUNEAU,AK 99801. RP TURNOCK, BJ (reprint author), ALASKA FISHERIES SCI CTR,RESOURCE ECOL & FISHERIES MANAGEMENT,7600 SANDPOINT WAY NE,BIN C15700,SEATTLE,WA 98115, USA. NR 23 TC 26 Z9 27 U1 0 U2 6 PU INTERNATIONAL BIOMETRIC SOC PI WASHINGTON PA 808 17TH ST NW SUITE 200, WASHINGTON, DC 20006-3910 SN 0006-341X J9 BIOMETRICS JI Biometrics PD JUN PY 1991 VL 47 IS 2 BP 701 EP 715 DI 10.2307/2532156 PG 15 WC Biology; Mathematical & Computational Biology; Statistics & Probability SC Life Sciences & Biomedicine - Other Topics; Mathematical & Computational Biology; Mathematics GA FV774 UT WOS:A1991FV77400026 ER PT J AU PENNINGTON, M VOLSTAD, JH AF PENNINGTON, M VOLSTAD, JH TI OPTIMUM SIZE OF SAMPLING UNIT FOR ESTIMATING THE DENSITY OF MARINE POPULATIONS SO BIOMETRICS LA English DT Article DE MARINE DENSITY ESTIMATES; MINIMIZING SURVEY COSTS; OPTIMUM SAMPLING UNIT SIZE; VARIANCE FUNCTION AB Data from several trawling experiments and from some scallop dredge surveys indicate that, within limits, a smaller sampling unit can be more efficient than a larger unit for marine abundance surveys. Taking into account survey costs and sampling variability, the unit size is found that produces the most precise density estimate given a fixed amount of survey resources or, if a certain level of precision is required, the size of sampling unit that minimizes the total cost of the survey. As an illustration, the optimum sampling unit sizes are derived for surveys of some fish populations and for a scallop stock on Georges Bank. C1 INST MARINE RES,N-5024 BERGEN,NORWAY. RP PENNINGTON, M (reprint author), NATL MARINE FISHERIES SERV,WOODS HOLE LAB,WOODS HOLE,MA 02543, USA. RI Volstad, Jon/B-7451-2014 NR 11 TC 31 Z9 32 U1 0 U2 13 PU INTERNATIONAL BIOMETRIC SOC PI WASHINGTON PA 808 17TH ST NW SUITE 200, WASHINGTON, DC 20006-3910 SN 0006-341X J9 BIOMETRICS JI Biometrics PD JUN PY 1991 VL 47 IS 2 BP 717 EP 723 DI 10.2307/2532157 PG 7 WC Biology; Mathematical & Computational Biology; Statistics & Probability SC Life Sciences & Biomedicine - Other Topics; Mathematical & Computational Biology; Mathematics GA FV774 UT WOS:A1991FV77400027 ER PT J AU RAMAMURTHY, MK RAUBER, RM COLLINS, BP SHIELDS, MT KENNEDY, PC CLARK, WL AF RAMAMURTHY, MK RAUBER, RM COLLINS, BP SHIELDS, MT KENNEDY, PC CLARK, WL TI UNIWIPP - A UNIVERSITY-OF-ILLINOIS FIELD EXPERIMENT TO INVESTIGATE THE STRUCTURE OF MESOSCALE PRECIPITATION IN WINTER STORMS SO BULLETIN OF THE AMERICAN METEOROLOGICAL SOCIETY LA English DT Article ID MID-LATITUDE CYCLONES; CONDITIONAL SYMMETRIC INSTABILITY; MICROSCALE STRUCTURE; COLD-FRONT; UNITED-STATES; GRAVITY-WAVES; DOPPLER RADAR; ORGANIZATION; CLOUDS; RAINBANDS AB To obtain a better understanding of the role of synoptic-scale disturbances in organizing mesoscale precipitation in the midwestern United States during the winter season, and to address scientific issues regarding mesoscale dynamics of winter storms, the University of Illinois Winter Precipitation Program was conducted over a period of three winters between 1988 and 1990. The observing systems included a 10-cm wavelength meteorological Doppler radar operated by the Illinois State Water Survey, the Flatland 6-m wind profiler operated by the NOAA Aeronomy Laboratory, and an NCAR Cross-chain Loran Atmospheric Sounding System. In all, 26 storms were observed during the 3-year period. The associated precipitation ranged from highly convective storms in the warm sector to stratified clouds containing organized banded structure within the occlusion. The principle dynamical mechanisms at work often varied widely from one storm to another and sometimes within a storm. This article describes the goals and objectives of the project, as well as a few selected observations and some preliminary findings from the data gathered. C1 DAMES & MOORE, PK RIDGE, IL USA. NATL WEATHER SERV, SOUTH BEND, IN USA. ILLINOIS STATE WATER SURVEY, CHAMPAIGN, IL 61820 USA. COLORADO STATE UNIV, DEPT ATMOSPHER SCI, FT COLLINS, CO 80523 USA. NOAA, AERON LAB, BOULDER, CO 80303 USA. RP UNIV ILLINOIS, DEPT ATMOSPHER SCI, URBANA, IL 61801 USA. NR 35 TC 12 Z9 12 U1 0 U2 0 PU AMER METEOROLOGICAL SOC PI BOSTON PA 45 BEACON ST, BOSTON, MA 02108-3693 USA SN 0003-0007 EI 1520-0477 J9 B AM METEOROL SOC JI Bull. Amer. Meteorol. Soc. PD JUN PY 1991 VL 72 IS 6 BP 764 EP 776 DI 10.1175/1520-0477(1991)072<0764:UAUOIF>2.0.CO;2 PG 13 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA FT231 UT WOS:A1991FT23100001 ER PT J AU CORMIER, VF MANDAL, B HARVEY, D AF CORMIER, VF MANDAL, B HARVEY, D TI INCORPORATION OF VELOCITY-GRADIENTS IN THE SYNTHESIS OF COMPLETE SEISMOGRAMS BY THE LOCKED MODE METHOD SO BULLETIN OF THE SEISMOLOGICAL SOCIETY OF AMERICA LA English DT Article ID EARTH MODELS; BODY WAVES; MEDIA; PHASES; DISPERSION; AMPLITUDES; POINT; CRUST AB Virtually all regional phases can be strongly affected by vertical velocity gradients. The best known effects are on the Pn and Sn, in which small changes in the vertical velocity gradient beneath the Moho produce large changes in the decay of Pn and Sn with distance. Methods of synthesizing complete regional seismograms often inadvertently ignore the effect of crustal gradients by parameterizing the Earth model with thick, planar homogeneous layers. To address this problem, we have modified the locked mode method of synthesizing complete regional seismograms to include the Langer uniform asymptotic approximation to vertical wavefunctions within layers having linear vertical velocity gradients. Synthesis of complete regional seismograms using the Langer-locked mode confirm that the Pn and Sn phases are strongly affected by the magnitude of the velocity gradients beneath the Moho, but that Lg is only weakly affected by the details of crustal layering. Tests were made to quantify the error in the use of the Langer approximation as the magnitude of the vertical gradient increases and/or frequency decreases. At sufficiently small magnitude of gradient and/or high frequency, good agreement can be obtained between synthetics computed using the Langer locked mode method, the colocation method, and the conventional locked mode method in models parameterized by thin homogeneous layers. Errors introduced by the use of the Langer approximation in calculated pole positions, residues, and eigenfunctions are bounded by 5 per cent for frequencies f greater-than-or-equal-to 5/del V/. An upper bound to the error in the time domain can be estimated from this inequality using either the peak frequency in a narrow pass band or the lowest frequency in a broad pass band. When 10 or more thin homogeneous layers are required to represent accurately the seismic wavefield in a gradient layer, it is usually more efficient to represent the gradient layer by continuously varying functions in the vertical direction and employ the Langer approximation, provided the errors in the Langer approximation remain within acceptable limits. By reducing the number of parameters needed to describe an earth model, the Langer locked mode method simplifies the inverse problem of determining structure using observed and synthetic complete seismograms. It also facilitates the use of known relations for the effects of continuously varying pressure and temperature on elastic moduli and density. C1 UNIV COLORADO,NOAA,COOPERAT INST RES ENVIRONM SCI,DEPT GEOL & GEOPHYS,BOULDER,CO 80309. MIT,DEPT EARTH ATMOSPHERE & PLANETARY SCI,EARTH RESOURCES LAB,CAMBRIDGE,MA 02139. RP CORMIER, VF (reprint author), UNIV CONNECTICUT,DEPT GEOL & GEOPHYS,BOX U-45,STORRS,CT 06269, USA. NR 44 TC 7 Z9 7 U1 0 U2 0 PU SEISMOLOGICAL SOC AMER PI EL CERRITO PA PLAZA PROFESSIONAL BLDG, SUITE 201, EL CERRITO, CA 94530 SN 0037-1106 J9 B SEISMOL SOC AM JI Bull. Seismol. Soc. Amer. PD JUN PY 1991 VL 81 IS 3 BP 897 EP 930 PG 34 WC Geochemistry & Geophysics SC Geochemistry & Geophysics GA FR329 UT WOS:A1991FR32900011 ER PT J AU COHEN, EB MOUNTAIN, DG OBOYLE, R AF COHEN, EB MOUNTAIN, DG OBOYLE, R TI LOCAL-SCALE VERSUS LARGE-SCALE FACTORS AFFECTING RECRUITMENT SO CANADIAN JOURNAL OF FISHERIES AND AQUATIC SCIENCES LA English DT Article ID TIME-SERIES; STOCKS AB Recent analyses of Atlantic cod (Gadus morhua) and haddock (Melanogrammus aeglefinus) stocks in the northwest Atlantic have indicated that large-scale factors (several hundred to thousands of kilometres) dominate over effects operating on more local scales (10 to a few hundred kilometres) in determining recruitment patterns for these stocks. Adding additional years and additional stocks to the data set, the recruitment time series for cod and haddock have been reexamined. A first differencing technique was used to remove trends in the data. The results indicate that while large-scale effects probably do affect recruitment, the dominant factors are operating on more local scales and correlations are strongest for neighboring stocks. C1 FISHERIES & OCEANS CANADA,BEDFORD INST OCEANOG,BIOL SCI BRANCH,DIV MARINE FISH,DARTMOUTH B2Y 4A2,NS,CANADA. RP COHEN, EB (reprint author), NOAA,NATL MARINE FISHERIES SERV,NE FISHERIES CTR,WOODS HOLE,MA 02543, USA. NR 15 TC 25 Z9 26 U1 1 U2 2 PU NATL RESEARCH COUNCIL CANADA PI OTTAWA PA RESEARCH JOURNALS, MONTREAL RD, OTTAWA ON K1A 0R6, CANADA SN 0706-652X J9 CAN J FISH AQUAT SCI JI Can. J. Fish. Aquat. Sci. PD JUN PY 1991 VL 48 IS 6 BP 1003 EP 1006 PG 4 WC Fisheries; Marine & Freshwater Biology SC Fisheries; Marine & Freshwater Biology GA FV226 UT WOS:A1991FV22600006 ER PT J AU ASSEL, RA AF ASSEL, RA TI IMPLICATIONS OF CO2 GLOBAL WARMING ON GREAT-LAKES ICE COVER SO CLIMATIC CHANGE LA English DT Article ID MODEL AB Statistical ice cover models were used to project daily mean basin ice cover and annual ice cover duration for Lakes Superior and Erie. Models were applied to a 1951-80 base period and to three 30-year steady double carbon dioxide (2 x CO2) scenarios produced by the Geophysical Fluid Dynamics Laboratory (GFDL), the Goddard Institute of Space Studies (GISS), and the Oregon State University (OSU) general circulation models. Ice cover estimates were made for the West, Central, and East Basins of Lake Erie and for the West, East, and Whitefish Bay Basins of Lake Superior. Average ice cover duration for the 1951-80 base period ranged from 13 to 16 weeks for individual lake basins. Reductions in average ice cover duration under the three 2 x CO2 scenarios for individual lake basins ranged from 5 to 12 weeks for the OSU scenario, 8 to 13 weeks for the GISS scenario, and 11 to 13 weeks for GFDL scenario. Winters without ice formation become common for Lake Superior under the GFDL scenario and under all three 2 x CO2 scenarios for the Central and East Basins of Lake Erie. During an average 2 x CO2 winter, ice cover would be limited to the shallow areas of Lakes Erie and Superior. Because of uncertainties in the ice cover models, the results given here represent only a first approximation and are likely to represent an upper limit of the extent and duration of ice cover under the climiate change projected by the three 2 x CO2 scenarios. Notwithstanding these limitations, ice cover projected by the 2 x CO2 scenarios provides a preliminary assessment of the potential sensitivity of the Great Lakes ice cover to global warming. Potential environmental and socioeconomic impacts of a 2 x CO2 warming include year-round navigation, change in abundance of some fish species in the Great Lakes, discontinuation or reduction of winter recreational activities, and an increase in winter lake evaporation. RP ASSEL, RA (reprint author), NOAA,US DEPT COMMERCE,GREAT LAKES ENVIRONM RES LAB,2205 COMMONWEALTH BLVD,ANN ARBOR,MI 48105, USA. NR 24 TC 23 Z9 23 U1 0 U2 5 PU KLUWER ACADEMIC PUBL PI DORDRECHT PA SPUIBOULEVARD 50, PO BOX 17, 3300 AA DORDRECHT, NETHERLANDS SN 0165-0009 J9 CLIMATIC CHANGE JI Clim. Change PD JUN PY 1991 VL 18 IS 4 BP 377 EP 395 DI 10.1007/BF00142968 PG 19 WC Environmental Sciences; Meteorology & Atmospheric Sciences SC Environmental Sciences & Ecology; Meteorology & Atmospheric Sciences GA FV753 UT WOS:A1991FV75300003 ER PT J AU FEELY, RA TREFRY, JH MASSOTH, GJ METZ, S AF FEELY, RA TREFRY, JH MASSOTH, GJ METZ, S TI A COMPARISON OF THE SCAVENGING OF PHOSPHORUS AND ARSENIC FROM SEAWATER BY HYDROTHERMAL IRON OXYHYDROXIDES IN THE ATLANTIC AND PACIFIC OCEANS SO DEEP-SEA RESEARCH PART A-OCEANOGRAPHIC RESEARCH PAPERS LA English DT Article ID DE-FUCA-RIDGE; METALLIFEROUS SEDIMENTS; SUSPENDED PARTICLES; NORTHEAST PACIFIC; PLUMES; RISE; CHEMISTRY; VENTS AB Studies of hydrothermal plumes on the Juan de Fuca Ridge and the Mid-Atlantic Ridge indicate that newly-formed Fe oxyhydroxides, formed as a consequence of hydrothermal venting, readily scavenge P and As from seawater in proportion to the dissolved concentrations of these elements. The Fe content of the suspended matter decreases from approximately 40% near the vents to < 5% in ambient seawater, with particulate P and As concentrations correlating well with Fe throughout this range. The P/Fe ratio in the oxyhydroxide phase is about 1.8 times higher in Juan de Fuca Ridge samples relative to samples from the Mid-Atlantic Ridge. In contrast, the As/Fe ratio in the oxyhydroxide phase is about the same for both regions. Calculated distribution coefficients for P and As in the Fe oxyhydroxide phase show remarkable agreement between the Atlantic and Pacific Oceans. Thus, inter-ocean variations in the element/Fe ratios are a function of dissolved concentrations of the chemical species. C1 FLORIDA INST TECHNOL,DEPT OCEANOG & OCEAN ENGN,MELBOURNE,FL 32901. RP FEELY, RA (reprint author), NOAA,PACIFIC MARINE ENVIRONM LAB,7600 SAND POINT WAY NE,SEATTLE,WA 98115, USA. OI Trefry, John/0000-0002-8451-5524 NR 32 TC 64 Z9 66 U1 0 U2 14 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD, ENGLAND OX5 1GB SN 0198-0149 J9 DEEP-SEA RES PD JUN PY 1991 VL 38 IS 6 BP 617 EP 623 DI 10.1016/0198-0149(91)90001-V PG 7 WC Oceanography SC Oceanography GA GC084 UT WOS:A1991GC08400001 ER PT J AU GARDNER, WS SEITZINGER, SP MALCZYK, JM AF GARDNER, WS SEITZINGER, SP MALCZYK, JM TI THE EFFECTS OF SEA SALTS ON THE FORMS OF NITROGEN RELEASED FROM ESTUARINE AND FRESH-WATER SEDIMENTS - DOES ION-PAIRING AFFECT AMMONIUM FLUX SO ESTUARIES LA English DT Article ID NATURAL-WATERS; DENITRIFICATION; COASTAL; MARINE; NUTRIENTS; NITRIFICATION; CHLOROPHYLL; ADSORPTION; ECOSYSTEMS AB In sediments with oxidized surface layers, the percentage of mineralized nitrogen that is nitrified/denitrified, compared with that released directly as ammonium, appears to be affected by the presence of sea salts. In estuarine systems, a significant portion of the nitrogen is released as ammonium, whereas in freshwater systems, most of the mineralized nitrogen is often released from the sediments as nitrogen gas. We hypothesized that this discrepancy is caused by differential competition between physical diffusion and nitrification/denitrification in the two systems. The vertical migration (by Fickian diffusion) of ammonium out of the oxic layer may be hindered by cation exchange (or sorption) interactions with sediment particles to a greater extent in fresh water than in estuarine systems. The resulting relatively long residence time, and potentially high levels of particle-bound ammonium in the freshwater sediments, would favor nitrification as the major ammonium removal process. By contrast, ion pair formation of ammonium with seawater anions and blockage of sediment cation exchange sites with seawater cations may allow a sizable fraction of the ammonium to diffuse out of estuarine sediments before it is nitrified. A salt effect, consistent with this hypothesis, has been demonstrated in experimental systems by changing the ionic composition of water flowing above intact cores of freshwater and estuarine sediments. Steady-state ammonium release from Lake Michigan sediments was substantially enhanced in the presence of 30% seawater over that in the presence of lake water alone. Likewise, steady-state ammonium release, from Ochlockonee River and Bay sediments (Florida) and from Toms River and Barnegat Bay sediments (New Jersey), was usually higher in the presence of diluted synthetic seawater than it was in the presence of fresh water. C1 ACAD NAT SCI PHILADELPHIA,DIV ENVIRONM RES,PHILADELPHIA,PA 19103. RP GARDNER, WS (reprint author), NOAA,GREAT LAKES ENVIRONM RES LAB,2205 COMMONWEALTH BLVD,ANN ARBOR,MI 48105, USA. NR 28 TC 81 Z9 99 U1 1 U2 16 PU ESTUARINE RES FEDERATION PI LAWRENCE PA PO BOX 368, LAWRENCE, KS 66044 SN 0160-8347 J9 ESTUARIES JI Estuaries PD JUN PY 1991 VL 14 IS 2 BP 157 EP 166 DI 10.2307/1351689 PG 10 WC Environmental Sciences; Marine & Freshwater Biology SC Environmental Sciences & Ecology; Marine & Freshwater Biology GA FW846 UT WOS:A1991FW84600006 ER PT J AU SEITZINGER, SP GARDNER, WS SPRATT, AK AF SEITZINGER, SP GARDNER, WS SPRATT, AK TI THE EFFECT OF SALINITY ON AMMONIUM SORPTION IN AQUATIC SEDIMENTS - IMPLICATIONS FOR BENTHIC NUTRIENT RECYCLING SO ESTUARIES LA English DT Article ID MARINE-SEDIMENTS; INORGANIC NITROGEN; LAKE-MICHIGAN; DENITRIFICATION; ADSORPTION; OXYGEN; WATER; ESTUARY; TEMPERATURE; BUDGET AB Ambient exchangeable ammonium concentrations in freshwater sediments are generally considerably greater than those reported for marine sediments. Laboratory measurements indicate that competition for cation exchange sites by ions in seawater is a factor responsible for the lower exchangeable ammonium concentrations in marine sediments. Exchangeable ammonium concentrations were 3- to 6-fold higher when river and estuarine sediments were incubated with fresh water relative to the same sediments incubated with salt water (parts per thousand = 23). A model was developed to explore the implications for benthic nitrogen cycling of this salinity effect on exchangeable ammonium concentrations. Ammonium diffusion, exchangeable and dissolved ammonium concentrations, and nitrification rates were components of the model formulation. The model output suggests that higher exchangeable ammonium concentrations predicted in fresh water relative to marine sediments can markedly increase the fraction of the ammonium produced in sediments that is nitrified (and subsequently denitrified). These results are consistent with field and experimental laboratory data which indicate that a larger percentage of net ammonium production in aerobic freshwater sediments is nitrified and denitrified (80-100%) relative to marine sediments (40-60%). C1 NOAA,GREAT LAKES ENVIRONM RES LAB,ANN ARBOR,MI 48105. RP SEITZINGER, SP (reprint author), ACAD NAT SCI PHILADELPHIA,DIV ENVIRONM RES,19TH & PKWY,PHILADELPHIA,PA 19103, USA. NR 41 TC 99 Z9 103 U1 2 U2 25 PU ESTUARINE RES FEDERATION PI LAWRENCE PA PO BOX 368, LAWRENCE, KS 66044 SN 0160-8347 J9 ESTUARIES JI Estuaries PD JUN PY 1991 VL 14 IS 2 BP 167 EP 174 DI 10.2307/1351690 PG 8 WC Environmental Sciences; Marine & Freshwater Biology SC Environmental Sciences & Ecology; Marine & Freshwater Biology GA FW846 UT WOS:A1991FW84600007 ER PT J AU POWELL, GVN FOURQUREAN, JW KENWORTHY, WJ ZIEMAN, JC AF POWELL, GVN FOURQUREAN, JW KENWORTHY, WJ ZIEMAN, JC TI BIRD COLONIES CAUSE SEAGRASS ENRICHMENT IN A SUBTROPICAL ESTUARY - OBSERVATIONAL AND EXPERIMENTAL-EVIDENCE SO ESTUARINE COASTAL AND SHELF SCIENCE LA English DT Article DE BIRDS; NUTRIENTS; SEAGRASSES; FERTILIZATION; FLORIDA KEYS ID SEABIRD GUANO; REEF COMMUNITIES; FLORIDA BAY; DECLINE; GROWTH; FISHES C1 UNIV VIRGINIA,DEPT ENVIRONM SCI,CHARLOTTESVILLE,VA 22903. NOAA,NATL MARINE FISHERIES SERV,SE FISHERIES CTR,BEAUFORT LAB,BEAUFORT,NC 28516. RP POWELL, GVN (reprint author), NATL AUDUBON SOC,115 INDIAN MOUND TRAIL,TAVERNIER,FL 33070, USA. RI Fourqurean, James/B-4606-2008 OI Fourqurean, James/0000-0002-0811-8500 NR 29 TC 68 Z9 69 U1 1 U2 29 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 JUN PY 1991 VL 32 IS 6 BP 567 EP 579 DI 10.1016/0272-7714(91)90075-M PG 13 WC Marine & Freshwater Biology; Oceanography SC Marine & Freshwater Biology; Oceanography GA FQ180 UT WOS:A1991FQ18000003 ER PT J AU MITCHELL, RA AF MITCHELL, RA TI MISALIGNMENT SENSITIVITY TEST FOR LOAD CELLS SO EXPERIMENTAL MECHANICS LA English DT Article AB A relatively simple test to measure the misalignment sensitivity of load cells is described. Eccentric compression loads are applied by the use of an angular block above the spherical loading button of the load cell. The results of replicate tests on six load cells, of five different types, produced by five different manufacturers, are presented. C1 NATL INST STAND & TECHNOL,GAITHERSBURG,MD. NR 4 TC 1 Z9 1 U1 0 U2 0 PU SOC EXPERIMENTAL MECHANICS PI BETHEL PA 7 SCHOOL STREET, BETHEL, CT 06801 SN 0014-4851 J9 EXP MECH JI Exp. Mech. PD JUN PY 1991 VL 31 IS 2 BP 140 EP 143 DI 10.1007/BF02327566 PG 4 WC Materials Science, Multidisciplinary; Mechanics; Materials Science, Characterization & Testing SC Materials Science; Mechanics GA FX638 UT WOS:A1991FX63800009 ER PT J AU HOFMANN, DJ OLTMANS, SJ DESHLER, T AF HOFMANN, DJ OLTMANS, SJ DESHLER, T TI SIMULTANEOUS BALLOONBORNE MEASUREMENTS OF STRATOSPHERIC WATER-VAPOR AND OZONE IN THE POLAR-REGIONS SO GEOPHYSICAL RESEARCH LETTERS LA English DT Article ID ACID AEROSOL FORMATION; NITRIC-ACID; ARCTIC STRATOSPHERE; TRANSPORT; HOLE AB Vertical profiles of stratospheric water vapor and ozone were measured together at McMurdo and South Pole Stations in Antarctia, and at Kiruna, Sweden, on several occasions during the austral spring of 1990 and the boreal winter of 1991. The Antarctic data indicated that major dehydration had occurred on a continental scale over the winter stratospheric cloud formation period leaving only 2 to 3 ppmv water vapor between 11 and 19 km. Measurements before and after movement of the boundary of the polar vortex across McMurdo detected increases in both water vapor and ozone in the 17 to 20 km region. This injected layer was still observed at South Pole Station a month later suggesting continental proportions. In early November, with the vortex still intact, South Pole measurements indicated a substantial degree of inhomogeneity in both water vapor and ozone in the lower stratosphere. In comparison, stratospheric water vapor measurements in the Arctic gave values of 4 to 5 ppmv indicating the absence of the gross stratospheric dehydration effects obvious in the Antarctic, and they did not reveal significant structure except on one occasion with very cold temperatures (-90-degrees-C) at 25 km and nacreous cloud displays. C1 UNIV WYOMING,DEPT PHYS & ASTRON,LARAMIE,WY 82071. RP HOFMANN, DJ (reprint author), NOAA,CLIMATE MONITORING & DIAGN LAB,325 BROADWAY,BOULDER,CO 80303, USA. NR 15 TC 10 Z9 10 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 JUN PY 1991 VL 18 IS 6 BP 1011 EP 1014 DI 10.1029/91GL01301 PG 4 WC Geosciences, Multidisciplinary SC Geology GA FR190 UT WOS:A1991FR19000007 ER PT J AU REID, GC SOLOMON, S GARCIA, RR AF REID, GC SOLOMON, S GARCIA, RR TI RESPONSE OF THE MIDDLE ATMOSPHERE TO THE SOLAR PROTON EVENTS OF AUGUST DECEMBER, 1989 SO GEOPHYSICAL RESEARCH LETTERS LA English DT Article ID STRATOSPHERIC OZONE; NITRIC-OXIDE; NITROGEN; MESOSPHERE AB Intense solar activity during the period August-December 1989 gave rise to several major energetic-particle events, which were accompanied by greatly enhanced ionization rates and NOy production in the polar regions of both hemispheres. A two-dimensional model of the chemistry and dynamics of the middle atmosphere has been used to calculate the production and subsequent fate of the NOy and its effect on ozone concentrations and temperatures. In the sunlit southern polar cap, NO increases as large as a factor of 20 are estimated near 60 km altitude, with column density enhancements of 55%. Corresponding peak ozone depletions of about 20% are calculated near 40 km in late October 1989, with predicted temperature decreases of about 3-3.5K. Effects in the northern polar regions are considerably smaller, due to the lack of sunlight during the peak phase of the events. C1 NATL CTR ATMOSPHER RES,BOULDER,CO 80307. RP REID, GC (reprint author), NOAA,AERON LAB,325 BROADWAY,BOULDER,CO 80303, USA. NR 17 TC 71 Z9 72 U1 1 U2 2 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 SN 0094-8276 J9 GEOPHYS RES LETT JI Geophys. Res. Lett. PD JUN PY 1991 VL 18 IS 6 BP 1019 EP 1022 DI 10.1029/91GL01049 PG 4 WC Geosciences, Multidisciplinary SC Geology GA FR190 UT WOS:A1991FR19000009 ER PT J AU VANBRUNT, RJ MISAKIAN, M KULKARNI, SV LAKDAWALA, VK AF VANBRUNT, RJ MISAKIAN, M KULKARNI, SV LAKDAWALA, VK TI INFLUENCE OF A DIELECTRIC BARRIER ON THE STOCHASTIC-BEHAVIOR OF TRICHEL-PULSE CORONA SO IEEE TRANSACTIONS ON ELECTRICAL INSULATION LA English DT Article ID PARTIAL DISCHARGES; NEGATIVE CORONA; SF6 AB The stochastic behavior of a negative, point-plane (Trichel-pulse) corona discharge in air has been investigated for the case where the plane electrode is partially covered with solid circular PTFE dielectric samples of varying diameter and position relative to the point electrode. This behavior is revealed from measurements of conditional and unconditional corona pulse-amplitude and pulse-time-separation distributions. The results indicate that the presence of a dielectric surface on the anode effectively reduces the electric field at the point electrode, but does not affect the occurrence of Trichel pulses, provided the point-to-plane gap spacing is greater than a critical value d(c) which depends on the area of the dielectric and the applied voltage. As the gap spacing approaches d(c), the effect of dielectric-surface charging by the corona introduces measurable 'memory effects' indicated by correlations between pulse amplitude and time separation from the previous pulse. For spacings less than d(c), detectable corona-pulse activity is quenched by the presence of a quasi-permanent surface charge on the dielectric. C1 INST PLASMA RES,BHAT GANDHINGAR,INDIA. OLD DOMINION UNIV,DEPT ELECT & COMP ENGN,NORFOLK,VA 23508. RP VANBRUNT, RJ (reprint author), NATL INST STAND & TECHNOL,GAITHERSBURG,MD, USA. NR 28 TC 16 Z9 16 U1 1 U2 6 PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017-2394 SN 0018-9367 J9 IEEE T ELECTR INSUL PD JUN PY 1991 VL 26 IS 3 BP 405 EP 415 DI 10.1109/14.85111 PG 11 WC Engineering, Electrical & Electronic SC Engineering GA FY343 UT WOS:A1991FY34300013 ER PT J AU CHERNIAVSKY, JC SMITH, CH AF CHERNIAVSKY, JC SMITH, CH TI ON WEYUKER AXIOMS FOR SOFTWARE COMPLEXITY-MEASURES SO IEEE TRANSACTIONS ON SOFTWARE ENGINEERING LA English DT Note ID DESIGN AB Properties for software complexity measures are explored. It is shown that a collection of properties suggested by Weyuker are inadequate for determining the quality of a software complexity measure. C1 NBS,COMP SYST LAB,WASHINGTON,DC 20234. UNIV MARYLAND,INST ADV COMP STUDIES,COLLEGE PK,MD 20742. UNIV MARYLAND,DEPT COMP SCI,COLLEGE PK,MD 20742. RP CHERNIAVSKY, JC (reprint author), NATL SCI FDN,COMP & INFORMAT SCI & ENGN DIRECTORATE,WASHINGTON,DC 20550, USA. NR 12 TC 25 Z9 27 U1 0 U2 0 PU IEEE COMPUTER SOC PI LOS ALAMITOS PA 10662 LOS VAQUEROS CIRCLE, PO BOX 3014, LOS ALAMITOS, CA 90720-1264 SN 0098-5589 J9 IEEE T SOFTWARE ENG JI IEEE Trans. Softw. Eng. PD JUN PY 1991 VL 17 IS 6 BP 636 EP 638 DI 10.1109/32.87287 PG 3 WC Computer Science, Software Engineering; Engineering, Electrical & Electronic SC Computer Science; Engineering GA FY323 UT WOS:A1991FY32300011 ER PT J AU TYNDALL, GS RAVISHANKARA, AR AF TYNDALL, GS RAVISHANKARA, AR TI ATMOSPHERIC OXIDATION OF REDUCED SULFUR SPECIES SO INTERNATIONAL JOURNAL OF CHEMICAL KINETICS LA English DT Review ID ABSOLUTE RATE CONSTANTS; GAS-PHASE REACTIONS; NO3 RADICAL REACTIONS; OH + H2S; TEMPERATURE-RANGE; DIMETHYL SULFIDE; HYDROGEN-SULFIDE; ORGANIC-COMPOUNDS; CH3S+NO2 REACTION; ALIPHATIC THIOLS AB The kinetics of elementary gas phase reactions involved in the oxidation of reduced sulfur species, H2S, CS2, OCS, CH3SH, CH3SCH3, and CH3SSCH3, to SO2 (or other products) are reviewed. The reactions with OH and NO3 which are the processes that initiate the degradation of the above compounds have been evaluated. Reactions of key intermediates, HS, HSO, CH3S, and CH3SO, are discussed. Whenever possible, recommendations for the rate coefficients are made and the need for further work indicated. The review has been carried out with the atmospheric chemistry in mind by looking at the laboratory based kinetics data. This review also provides information that will help model the Earth's sulfur cycle. C1 UNIV COLORADO,DEPT CHEM & BIOCHEM,BOULDER,CO 80309. NOAA,BOULDER,CO 80303. RI Ravishankara, Akkihebbal/A-2914-2011 NR 131 TC 232 Z9 236 U1 4 U2 41 PU JOHN WILEY & SONS INC PI NEW YORK PA 605 THIRD AVE, NEW YORK, NY 10158-0012 SN 0538-8066 J9 INT J CHEM KINET JI Int. J. Chem. Kinet. PD JUN PY 1991 VL 23 IS 6 BP 483 EP 527 DI 10.1002/kin.550230604 PG 45 WC Chemistry, Physical SC Chemistry GA FN770 UT WOS:A1991FN77000003 ER PT J AU HUIE, RE SHOUTE, LCT NETA, P AF HUIE, RE SHOUTE, LCT NETA, P TI TEMPERATURE-DEPENDENCE OF THE RATE CONSTANTS FOR REACTIONS OF THE CARBONATE RADICAL WITH ORGANIC AND INORGANIC REDUCTANTS SO INTERNATIONAL JOURNAL OF CHEMICAL KINETICS LA English DT Article ID LEAST-SQUARES METHOD; PULSE-RADIOLYSIS; AQUEOUS-SOLUTION; AMINO-ACIDS; ARRHENIUS PARAMETERS; FLASH-PHOTOLYSIS; WATER; REACTIVITY; COMPLEXES; OXIDATION AB Rate constants have been measured by pulse radiolysis for the reactions of the carbonate radical, CO3.-, with a number of organic and inorganic reactants as a function of temperature, generally over the range 5 to 80-degrees-C. The reactants include the substitution-inert cyano complexes of Fe(II), MO(IV), and W(IV), the simple inorganic anions SO3(2-), ClO2-, NO2-, I-, and SCN-, several phenolates, ascorbate, tryptophan, cysteine, cystine, methionine, triethylamine, and allyl alcohol. The measured rate constants ranged from less than 10(5) to 3 x 10(9) M-1 s-1, the activation energies ranged from -11.4 to 18.8 kJ mol-1, and the pre-exponential factors ranged from log A = 6.4 to 10.7. The activation energies for the metal complexes and inorganic anions generally decrease with increasing driving force for the reaction, as expected for an outer sphere electron transfer. For highly exothermic reactions, however, the activation energy appears to increase, probably reflecting the temperature dependence of diffusion. For many of the organic reactants, the activation energies were low and independent of driving force, suggesting that the oxidation is via an inner sphere mechanism. RP HUIE, RE (reprint author), NATL INST STAND & TECHNOL,DIV CHEM KINET,GAITHERSBURG,MD 20899, USA. RI Huie, Robert/A-5645-2010 NR 30 TC 40 Z9 40 U1 3 U2 12 PU JOHN WILEY & SONS INC PI NEW YORK PA 605 THIRD AVE, NEW YORK, NY 10158-0012 SN 0538-8066 J9 INT J CHEM KINET JI Int. J. Chem. Kinet. PD JUN PY 1991 VL 23 IS 6 BP 541 EP 552 DI 10.1002/kin.550230606 PG 12 WC Chemistry, Physical SC Chemistry GA FN770 UT WOS:A1991FN77000005 ER PT J AU TRAVIS, JC TURK, GC WATTERS, RL YU, LJ BLUE, JL AF TRAVIS, JC TURK, GC WATTERS, RL YU, LJ BLUE, JL TI TRACE DETECTION IN CONDUCTING SOLIDS USING LASER-INDUCED FLUORESCENCE IN A CATHODIC SPUTTERING CELL SO JOURNAL OF ANALYTICAL ATOMIC SPECTROMETRY LA English DT Article DE CATHODIC SPUTTERING; DIFFUSION; GLOW DISCHARGE; LASER-INDUCED FLUORESCENCE; SOLID SAMPLING ID ATOMIC-ABSORPTION SPECTROMETRY; GLOW-DISCHARGE SOURCE; EXCITED FLUORESCENCE; EMISSION SOURCE; SPECTROSCOPY; ATOMIZATION; DENSITIES; SAMPLES; METALS; COPPER AB A cathodic sputtering atom reservoir designed for atomic absorption spectrometry of conducting solid samples is examined as a potential sampling device for trace and ultra-trace detection using laser-induced fluorescence (LIF) spectrometry. The analytical results are promising, with sub-mu-g g-1 sensitivity for the model analyte (Fe) in brass samples, and with reasonable precision and accuracy (+/- 15%) for the pulsed laser system used, but with far less sensitivity than might be predicted. Noise studies clearly indicate that laser-induced background fluorescence is the principal limiting noise source. Fundamental material transport studies indicate that diffusional loss of atomic number density to the walls is of much less importance than the background fluorescence in determining the sensitivity of the system. Extrapolations based on cell-experiment design to maximize number density and minimize background emission and fluorescence promise ng g-1 sensitivities for future implementations. RP TRAVIS, JC (reprint author), NATL INST STAND & TECHNOL,GAITHERSBURG,MD 20899, USA. RI Yu, Lee/N-7263-2015 OI Yu, Lee/0000-0002-8043-6853 NR 47 TC 6 Z9 6 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 JUN PY 1991 VL 6 IS 4 BP 261 EP 271 DI 10.1039/ja9910600261 PG 11 WC Chemistry, Analytical; Spectroscopy SC Chemistry; Spectroscopy GA FN654 UT WOS:A1991FN65400004 ER PT J AU LEE, JW RITTER, W LECCIONES, J KELLY, P PIZZO, PA WALSH, TJ AF LEE, JW RITTER, W LECCIONES, J KELLY, P PIZZO, PA WALSH, TJ TI PLASMA PHARMACOKINETICS AND TISSUE PENETRATION OF A NOVEL ANTIFUNGAL TRIAZOLE, BAY-R-3783, AND ITS LONG-LASTING ACTIVE METABOLITE, BAY-U-3625, IN RABBITS SO JOURNAL OF ANTIMICROBIAL CHEMOTHERAPY LA English DT Article ID FUNGAL-INFECTIONS; MODELS C1 BAYER AG,INST CLIN PHARMACOL,W-5600 WUPPERTAL 1,GERMANY. RP LEE, JW (reprint author), NBS,PEDIAT BRANCH,INFECT DIS SECT,WASHINGTON,DC 20234, USA. NR 13 TC 1 Z9 1 U1 0 U2 0 PU W B SAUNDERS CO LTD PI LONDON PA 24-28 OVAL RD, LONDON, ENGLAND NW1 7DX SN 0305-7453 J9 J ANTIMICROB CHEMOTH JI J. Antimicrob. Chemother. PD JUN PY 1991 VL 27 IS 6 BP 837 EP 844 DI 10.1093/jac/27.6.837 PG 8 WC Infectious Diseases; Microbiology; Pharmacology & Pharmacy SC Infectious Diseases; Microbiology; Pharmacology & Pharmacy GA FT015 UT WOS:A1991FT01500017 PM 1938690 ER PT J AU BIRKENHEUER, D AF BIRKENHEUER, D TI AN ALGORITHM FOR OPERATIONAL WATER-VAPOR ANALYSES INTEGRATING GOES AND DUAL-CHANNEL MICROWAVE RADIOMETER DATA ON THE LOCAL SCALE SO JOURNAL OF APPLIED METEOROLOGY LA English DT Article ID TEMPERATURE; RETRIEVAL; PROFILES; LEVEL AB An algorithm for the operational integration of satellite-derived and ground-based passive microwave precipitable-water measurements is presented. The technique merges the two data types by relying on the more accurate ground-based data to correct the bias and scale the satellite field, thus providing an improved meso-beta-scale analysis. The complete algorithm is described from the preparation of the derived satellite imagery, used here as a data source, to the optimization routine used to integrate the data. The technique is now used for a local-scale analysis of the Denver area. One case is presented illustrating the effectiveness of the technique to track a weak moisture gradient through eastern Colorado. Other cases demonstrate the performance of the analysis in varying topography. RP BIRKENHEUER, D (reprint author), NOAA,ENVIRONM RES LABS,FORECAST SYST LAB,PROGRAM REG OBSERVING & FORECASTING SERV,BOULDER,CO 80303, USA. RI Birkenheuer, Daniel/E-7378-2015 NR 16 TC 14 Z9 14 U1 0 U2 0 PU AMER METEOROLOGICAL SOC PI BOSTON PA 45 BEACON ST, BOSTON, MA 02108-3693 SN 0894-8763 J9 J APPL METEOROL JI J. Appl. Meteorol. PD JUN PY 1991 VL 30 IS 6 BP 834 EP 843 DI 10.1175/1520-0450(1991)030<0834:AAFOWV>2.0.CO;2 PG 10 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA FT384 UT WOS:A1991FT38400006 ER PT J AU NEIMAN, PJ MAY, PT STANKOV, BB SHAPIRO, MA AF NEIMAN, PJ MAY, PT STANKOV, BB SHAPIRO, MA TI RADIO ACOUSTIC SOUNDING SYSTEM OBSERVATIONS OF AN ARCTIC FRONT SO JOURNAL OF APPLIED METEOROLOGY LA English DT Article ID TEMPERATURE-MEASUREMENTS; RASS; PROFILER AB A radio acoustic sounding system (RASS), coupled with the NOAA/Wave Propagation Laboratory 915-MHz wind profiler, observed an arctic front and arctic air mass that passed over Denver, Colorado, between 1 and 5 February 1989. The RASS temperature measurements extended to approximately 1.5 km above ground level and were taken at 15-min intervals during the frontal passage and at 1-h intervals thereafter. During the frontal passage on 1 February, the RASS documented a temperature decrease of > 15-degrees-C. The succeeding cold air (approximately -20-degrees to -40-degrees-C) over Denver never exceeded 1.3 km in depth. The frontal inversion at the top of the cold air mass was 300 m in depth and possessed large static stability [-partial-theta/partial-p approximately 80 K (100 mb)-1] and vertical wind shear [-partial-V/partial-p approximately 30 m s-1 (100 mb)-1]. Temporal fluctuations (approximately 3 h) in the depth of the cold air were observed by the RASS between the operational 12-h rawinsonde observing periods. Simultaneous RASS and rawinsonde measurements showed good agreement with regard to key thermal feature. C1 UNIV COLORADO,NOAA,COOPERAT INST RES ENVIRONM SCI,BOULDER,CO 80309. RP NEIMAN, PJ (reprint author), NOAA,ENVIRONM RES LABS,WAVE PROPAGAT LAB,325 BROADWAY,BOULDER,CO 80303, USA. NR 24 TC 8 Z9 9 U1 0 U2 1 PU AMER METEOROLOGICAL SOC PI BOSTON PA 45 BEACON ST, BOSTON, MA 02108-3693 SN 0894-8763 J9 J APPL METEOROL JI J. Appl. Meteorol. PD JUN PY 1991 VL 30 IS 6 BP 881 EP 892 DI 10.1175/1520-0450(1991)030<0881:RASSOO>2.0.CO;2 PG 12 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA FT384 UT WOS:A1991FT38400009 ER PT J AU SCHEINFEIN, MR BLUE, JL AF SCHEINFEIN, MR BLUE, JL TI MICROMAGNETIC CALCULATIONS OF 180-DEGREES SURFACE DOMAIN-WALLS SO JOURNAL OF APPLIED PHYSICS LA English DT Article ID SCANNING ELECTRON-MICROSCOPY; FILMS; MAGNETIZATION; FERROMAGNET; SPIN AB We compare quantitative results from two methods of solving the micromagnetics equations for 180-degrees domain walls. The first method solves the Landau-Lifshitz-Gilbert equation by time integration of the stiff differential equations. The second method uses a relaxation scheme to determine the equilibrium domain wall magnetization configuration. We compare results from these calculations for various damping parameters and discretization mesh densities, and also compare our results with domain wall measurements made using scanning electron microscopy with polarization analysis. We conclude that equilibrium domain wall microstructure is insensitive to the damping parameter used in the time method of solution for domain walls in magnetically soft iron and Permalloy. For large damping parameters, the approach to equilibrium is the same for the time method and the relaxation method. Further, we can obtain metastable equilibrium states with both methods. C1 NATL INST STAND & TECHNOL, GAITHERSBURG, MD 20899 USA. NR 35 TC 34 Z9 34 U1 0 U2 3 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 JUN 1 PY 1991 VL 69 IS 11 BP 7740 EP 7751 DI 10.1063/1.347499 PG 12 WC Physics, Applied SC Physics GA FP401 UT WOS:A1991FP40100053 ER PT J AU JIA, JJ CALLCOTT, TA OBRIEN, WL DONG, QY MUELLER, DR RUBENSSON, JE EDERER, DL TAN, Z NAMAVAR, F BUDNICK, JI AF JIA, JJ CALLCOTT, TA OBRIEN, WL DONG, QY MUELLER, DR RUBENSSON, JE EDERER, DL TAN, Z NAMAVAR, F BUDNICK, JI TI A SOFT-X-RAY-EMISSION INVESTIGATION OF COBALT IMPLANTED SILICON-CRYSTALS SO JOURNAL OF APPLIED PHYSICS LA English DT Article AB The Si L2,3 emission spectra of silicon crystals implanted with Co at doses of (1-8) X 10(17) Co/cm2 have been examined using soft-x-ray-emission (SXE) spectroscopy. At the lowest dose, the spectra are little modified from that of crystalline Si, indicating that only a small fraction of Si is in the form of silicides within the probe depth of SXE spectroscopy. For higher doses and implant profiles with Co extending to the surface, there is clear evidence for ordered CoSi2 combined with richer Co phases, but little evidence for pure Si or for ordered regions of CoSi. C1 NATL INST STAND & TECHNOL,GAITHERSBURG,MD 20899. UNIV CONNECTICUT,STORRS,CT 06269. RP JIA, JJ (reprint author), UNIV TENNESSEE,KNOXVILLE,TN 37996, USA. NR 5 TC 4 Z9 4 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 JUN 1 PY 1991 VL 69 IS 11 BP 7800 EP 7804 DI 10.1063/1.347508 PG 5 WC Physics, Applied SC Physics GA FP401 UT WOS:A1991FP40100063 ER PT J AU BRANDES, EA RABIN, RM AF BRANDES, EA RABIN, RM TI PROBING A NONPRECIPITATING COLD-FRONT WITH DOPPLER WEATHER RADAR SO JOURNAL OF ATMOSPHERIC AND OCEANIC TECHNOLOGY LA English DT Article AB The utility of Doppler radar to study boundary-layer kinematics of a weak nonprecipitating cold front in Oklahoma on 16 October 1987 was examined with measurements from two radars. Diagnosis was impeded by operation at low antenna elevation angles, short radar ranges, and low signal-to-noise ratios. Further, kinematic parameters computed by single-radar velocity-azimuth-display (VAD) technique for meterological wavelengths < 125 km were significantly smoothed (more than 50% attenuated). Meteorological scales greater-than-or-equal-to 5 km were well resolved (less than 50% attenuated) in wind fields synthesized from parameters were particularly sensitive to the vertical dual-Doppler radar observations, but derived extrapolation of radial velocity measurements in the presence of strong vertical wind shear. Nonetheless, radar-derived wind flows depicted a sequence of events consistent with other instrumentation. In the vicinity of the front, mean-flow divergence, vertical velocity, and deformation, computed from single-radar measurements for an analysis domain of 30-km radius, were -4 x 10(-5) s-1, 3cm s-1, and 16 x 10(-5) s-1, respectively. Agreement between the radars attested to the accuracy of the measurements. Local peak absolute values of divergence, deformation, and vertical vorticity, determined from dual-Doppler analysis, were 200-300(x 10(-5)) s-1. Extrema were concentrated along the frontal zone where signals were strong, and had dimensions of approximately 10 km. RP BRANDES, EA (reprint author), NOAA,NATL SEVERE STORMS LAB,ENVIRONM RES LABS,1313 HALLEY CIRCLE,NORMAN,OK 73069, USA. NR 0 TC 5 Z9 5 U1 0 U2 0 PU AMER METEOROLOGICAL SOC PI BOSTON PA 45 BEACON ST, BOSTON, MA 02108-3693 SN 0739-0572 J9 J ATMOS OCEAN TECH JI J. Atmos. Ocean. Technol. PD JUN PY 1991 VL 8 IS 3 BP 409 EP 421 DI 10.1175/1520-0426(1991)008<0409:PANCFW>2.0.CO;2 PG 13 WC Engineering, Ocean; Meteorology & Atmospheric Sciences SC Engineering; Meteorology & Atmospheric Sciences GA FQ925 UT WOS:A1991FQ92500010 ER PT J AU FRASER, GT PINE, AS KREINER, WA AF FRASER, GT PINE, AS KREINER, WA TI OPTOTHERMAL-DETECTED MICROWAVE-SIDE-BAND CO2-LASER SPECTROSCOPY OF AR-NH3 SO JOURNAL OF CHEMICAL PHYSICS LA English DT Article ID NU-2 BAND; LASER; TRANSITIONS; (NH3)-N-14; NH3 AB A microwave-sideband CO2-laser optothermal spectrometer with a resolution better than 1 MHz has been used to record the infrared spectrum of Ar-NH3 in the vicinity of the aR(0,0) line of the v2 vibration of free NH3. A PI <-- SIGMA type band is observed, giving a positive l-type doubling constant q, of 90.9 MHz for the upper state. The positive q indicates that the j = 1, k = 0, SIGMA state is above the j = 1, k = 0, PI state in the upsilon-2 = 1 excited state, where j and k specify the correlation of the internal-rotor state of the Ar-NH3 complex to the NH3 monomer rotational state j,k. The v2 vibrationally excited complex is found to predissociate in less than the 0.9 ms transit time between the bolometer detector and laser-excitation region. A lower limit to the upper-state lifetime can be obtained from the observed linewidths, which range from 1.5 to 3 MHz (FWHM). The present results agree with and extend the previous free-jet diode-laser absorption measurements on this band. RP FRASER, GT (reprint author), NATL INST STAND & TECHNOL,DIV MOLEC PHYS,GAITHERSBURG,MD 20899, USA. NR 23 TC 34 Z9 34 U1 0 U2 2 PU AMER INST PHYSICS PI WOODBURY PA CIRCULATION FULFILLMENT DIV, 500 SUNNYSIDE BLVD, WOODBURY, NY 11797-2999 SN 0021-9606 J9 J CHEM PHYS JI J. Chem. Phys. PD JUN 1 PY 1991 VL 94 IS 11 BP 7061 EP 7067 DI 10.1063/1.460239 PG 7 WC Chemistry, Physical; Physics, Atomic, Molecular & Chemical SC Chemistry; Physics GA FL837 UT WOS:A1991FL83700012 ER PT J AU PARLANT, G SENEKOWITSCH, J ONEIL, SV YARKONY, DR AF PARLANT, G SENEKOWITSCH, J ONEIL, SV YARKONY, DR TI SPIN-FORBIDDEN DECAY OF THE DICATION HS2+ SO JOURNAL OF CHEMICAL PHYSICS LA English DT Article ID CONFIGURATION-INTERACTION METHOD; SPACE SCF METHOD; POTENTIAL CURVES; PREDISSOCIATION; EXPANSIONS; STATES; CL; PH AB The lifetimes of the low-lying vibrational levels of the X2-PI state of the recently identified dication HS2+ [Miller et al., Int. J. Mass Spectrom. Ion Proc. 100, 505 (1990)] are considered. The stability of this state is attributable to a barrier formed from the avoided crossing of 2-PI states asymptotically characterized as H+ + S+ and H + S2+. As a result of this barrier, the nonrelativistic X2-PI potential energy curve supports several quasibound vibrational levels that are long lived with respect to tunneling. However, this is not the principal decay mechanism. We show that the lifetimes of the low-lying vibrational levels, upsilon = 0 - 4, are controlled entirely by the spin-orbit induced perturbation, 1(4)SIGMA- approximately X2-PI, and the corresponding allowed crossing of the X2-PI potential energy curve by the dissociative 1(4)SIGMA- potential energy curve which correlates with the ground state asymptote H+ + S+ (4S). C1 JOHNS HOPKINS UNIV,DEPT CHEM,BALTIMORE,MD 21218. UNIV COLORADO,NATL INST STAND & TECHNOL,JOINT INST LAB ASTROPHYS,BOULDER,CO 80302. NR 30 TC 12 Z9 12 U1 0 U2 0 PU AMER INST PHYSICS PI WOODBURY PA CIRCULATION FULFILLMENT DIV, 500 SUNNYSIDE BLVD, WOODBURY, NY 11797-2999 SN 0021-9606 J9 J CHEM PHYS JI J. Chem. Phys. PD JUN 1 PY 1991 VL 94 IS 11 BP 7208 EP 7211 DI 10.1063/1.460203 PG 4 WC Chemistry, Physical; Physics, Atomic, Molecular & Chemical SC Chemistry; Physics GA FL837 UT WOS:A1991FL83700027 ER PT J AU ROBERTSON, B ASTUMIAN, RD AF ROBERTSON, B ASTUMIAN, RD TI FREQUENCY-DEPENDENCE OF CATALYZED-REACTIONS IN A WEAK OSCILLATING FIELD SO JOURNAL OF CHEMICAL PHYSICS LA English DT Article ID ELECTRIC-FIELD; ENERGY TRANSDUCTION; ENZYME; (NA,K)-ATPASE; ABSORPTION; ACTIVATION AB The frequency dependence of the average rates of reactions catalyzed by one or more catalysts in a weak oscillating field is derived. The average rates are sums of Lorentzian curves whose characteristic frequencies are the inverse relaxation times of the normal modes of the kinetic system and whose amplitudes are quadratic in the field. The signs of the Lorentz amplitudes can be either positive or negative, so the rates versus frequency can have a variety of shapes, including frequency windows. One can get relaxation times and amplitudes by measuring steady-state rates as a function of the frequency of the field. The theory is applied to determine the Lorentz amplitudes and characteristic frequencies of ion transport rates catalyzed by Na+-K+-ATPase in erythrocytes. RP ROBERTSON, B (reprint author), NATL INST STAND & TECHNOL,GAITHERSBURG,MD 20899, USA. NR 24 TC 79 Z9 79 U1 0 U2 5 PU AMER INST PHYSICS PI WOODBURY PA CIRCULATION FULFILLMENT DIV, 500 SUNNYSIDE BLVD, WOODBURY, NY 11797-2999 SN 0021-9606 J9 J CHEM PHYS JI J. Chem. Phys. PD JUN 1 PY 1991 VL 94 IS 11 BP 7414 EP 7419 DI 10.1063/1.460173 PG 6 WC Chemistry, Physical; Physics, Atomic, Molecular & Chemical SC Chemistry; Physics GA FL837 UT WOS:A1991FL83700049 ER PT J AU RICE, BM TREVINO, SF AF RICE, BM TREVINO, SF TI AN INTERMOLECULAR H-O POTENTIAL FOR METHYL ROTATIONS IN SOLID NITROMETHANE SO JOURNAL OF CHEMICAL PHYSICS LA English DT Article AB A reliable determination of the (H-O) intermolecular potential by which molecules of nitromethane interact with each other is presented. This effort is based upon a very complete body of experimental information which is available on the crystal structure and the rotational properties of the methyl group of the molecule in the solid state. The crystal structure is known in the temperature range of 4-233 K. The rotational properties of the methyl group of the molecule have been studied by inelastic neutron scattering with which the energy levels, including the ground state tunnel splitting, have been measured in both the protonated and deuterated samples. These studies provide a most comprehensive characterization of any such similar molecular crystal. The measured properties are directly related to the intermolecular potential but the inversion of the underlying intermolecular potential from the measured properties has not been straight forward. We describe the application of the principle of maximum entropy in the determination of an intermolecular H-O potential. The resulting potential is of a novel character. At 3.5 GPa x-ray diffraction studies indicate that the equilibrium orientation of the methyl group in crystalline nitromethane is rotated 45-degrees from the position in the low-temperature ambient pressure form. Calculations of the potential energy as a function of methyl group orientation in crystalline nitromethane at a pressure of 3.5 GPa using the intermolecular potential described herein has reproduced this experimental observation. C1 AED,ARDEC,PICATINNY ARSENAL,NJ. NATL INST STAND & TECHNOL,GAITHERSBURG,MD. RP RICE, BM (reprint author), USA,BALLIST RES LABS,SLCBR IB I,ABERDEEN PROVING GROUND,MD 21005, USA. NR 14 TC 16 Z9 16 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 JUN 1 PY 1991 VL 94 IS 11 BP 7478 EP 7485 DI 10.1063/1.460178 PG 8 WC Chemistry, Physical; Physics, Atomic, Molecular & Chemical SC Chemistry; Physics GA FL837 UT WOS:A1991FL83700055 ER PT J AU DETMAN, TR DRYER, M YEH, T HAN, SM WU, ST MCCOMAS, DJ AF DETMAN, TR DRYER, M YEH, T HAN, SM WU, ST MCCOMAS, DJ TI A TIME-DEPENDENT, 3-DIMENSIONAL MHD NUMERICAL STUDY OF INTERPLANETARY MAGNETIC DRAPING AROUND PLASMOIDS IN THE SOLAR-WIND SO JOURNAL OF GEOPHYSICAL RESEARCH-SPACE PHYSICS LA English DT Article ID CORONAL MASS EJECTA; CLOUDS; EVENTS; TRANSIENTS; FIELDS; BURST AB A spherical plasmoid is injected into a representative solar wind at 18 solar radii, which is chosen as the lower computational boundary of a 3-dimensional MHD model. The field line topology of the injected plasmoid resembles the streamline topology of a spherical vortex. Evolution of the plasmoid and its surrounding interplanetary medium is described out to approximately 1 AU for three cases with different velocities imparted to the plasmoid. In the first case a plasmoid enters the lower boundary with a velocity of 250 km s-1 equal to the steady state background solar wind velocity at the lower boundary. In the second and third cases the plasmoid enters with peak velocities of twice and 3 times the background velocity. A number of interesting features are found. For instance, the evolving plasmoid retains its basic magnetic topology although the shape becomes distorted. As might be expected, the shape distortion increases with the injection velocity. Development of a bow shock occurs when the plasmoid is injected with a velocity greater than the sum of the local fast magnetosonic speed and the ambient solar wind velocity. The MHD simulation demonstrates magnetic draping around the plasmoid. C1 TENNESSEE TECHNOL UNIV,DEPT MECH ENGN,COOKEVILLE,TN 38505. UNIV ALABAMA,CTR SPACE PLASMA & AERON RES,HUNTSVILLE,AL 35899. UNIV ALABAMA,DEPT MECH ENGN,HUNTSVILLE,AL 35899. UNIV CALIF LOS ALAMOS SCI LAB,LOS ALAMOS,NM 87545. RP DETMAN, TR (reprint author), NOAA,ENVIRONM RES LABS,SPACE ENVIRONM LAB,R-E-SE,325 BROADWAY,BOULDER,CO 80303, USA. NR 29 TC 70 Z9 70 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 JUN 1 PY 1991 VL 96 IS A6 BP 9531 EP 9540 DI 10.1029/91JA00443 PG 10 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA FV651 UT WOS:A1991FV65100012 ER PT J AU YU, SC LYNN, JW RHYNE, JJ FISH, GE AF YU, SC LYNN, JW RHYNE, JJ FISH, GE TI LOW-TEMPERATURE MAGNETIZATION AND MAGNETIC EXCITATIONS IN AMORPHOUS FE78B13SI9 SO JOURNAL OF MAGNETISM AND MAGNETIC MATERIALS LA English DT Article AB We have carried out a study of the low-temperature magnetization and spin-wave dispersion in the amorphous metallic ferromagnet Fe78B13Si9. The temperature dependence of the magnetization was measured with a vibrating sample magnetometer and the spin-wave measurements were carried out using inelastic neutron scattering techniques. The magnetization is found to obey the usual law M(s)(T) = M(s)(0)(1 - BT3/2 - CT5/2 ...), while the spin waves follow the conventional ferromagnetic dispersion relation E(q) = D(T)q2 + DELTA + .... The spin wave stiffness constant D(T) is found to be substantially larger than the value inferred from the magnetization data, similar to the behavior observed in other Invar-type materials. C1 NATL INST STAND & TECHNOL,GAITHERSBURG,MD 20899. ALLIED SIGNAL INC,MORRISTOWN,NJ 07962. CHUNG BUK NATL UNIV,DEPT PHYS,CHUNGBUK 360763,SOUTH KOREA. RP YU, SC (reprint author), UNIV MARYLAND,DEPT PHYS,COLLEGE PK,MD 20742, USA. NR 9 TC 3 Z9 3 U1 1 U2 1 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0304-8853 J9 J MAGN MAGN MATER JI J. Magn. Magn. Mater. PD JUN PY 1991 VL 97 IS 1-3 BP 286 EP 290 DI 10.1016/0304-8853(91)90193-E PG 5 WC Materials Science, Multidisciplinary; Physics, Condensed Matter SC Materials Science; Physics GA FY520 UT WOS:A1991FY52000041 ER PT J AU VANEK, MD WELLS, JS MAKI, AG AF VANEK, MD WELLS, JS MAKI, AG TI PRESSURE DEPENDENT LINESHIFT MEASUREMENTS ON OCS SO JOURNAL OF MOLECULAR SPECTROSCOPY LA English DT Article ID ABSOLUTE FREQUENCY MEASUREMENTS; HALF-WIDTHS; LINE; SPECTROSCOPY; HETERODYNE; BANDS; TRANSITIONS; MODULATION; PARAMETERS; STRENGTHS C1 UNIV WASHINGTON,DEPT CHEM,SEATTLE,WA 98195. RP VANEK, MD (reprint author), NAT INST STANDARDS & TECHNOL,DIV TIME & FREQUENCY,BOULDER,CO 80303, USA. NR 23 TC 6 Z9 6 U1 0 U2 0 PU ACADEMIC PRESS INC JNL-COMP SUBSCRIPTIONS PI SAN DIEGO PA 525 B ST, STE 1900, SAN DIEGO, CA 92101-4495 SN 0022-2852 J9 J MOL SPECTROSC JI J. Mol. Spectrosc. PD JUN PY 1991 VL 147 IS 2 BP 398 EP 405 DI 10.1016/0022-2852(91)90065-I PG 8 WC Physics, Atomic, Molecular & Chemical; Spectroscopy SC Physics; Spectroscopy GA FL581 UT WOS:A1991FL58100010 ER PT J AU MERDES, DW PLIVA, J PINE, AS AF MERDES, DW PLIVA, J PINE, AS TI PERPENDICULAR BANDS OF CYCLOPROPANE IN THE 3.5-MU-M REGION SO JOURNAL OF MOLECULAR SPECTROSCOPY LA English DT Article ID FOURIER-TRANSFORM; SPECTRA; SPECTROSCOPY; NU-11 C1 NATL INST STANDARDS & TECHNOL,DIV MOLEC PHYS,GAITHERSBURG,MD 20899. RP MERDES, DW (reprint author), PENN STATE UNIV,DEPT PHYS,UNIVERSITY PK,PA 16802, USA. NR 25 TC 8 Z9 8 U1 0 U2 0 PU ACADEMIC PRESS INC JNL-COMP SUBSCRIPTIONS PI SAN DIEGO PA 525 B ST, STE 1900, SAN DIEGO, CA 92101-4495 SN 0022-2852 J9 J MOL SPECTROSC JI J. Mol. Spectrosc. PD JUN PY 1991 VL 147 IS 2 BP 431 EP 447 DI 10.1016/0022-2852(91)90068-L PG 17 WC Physics, Atomic, Molecular & Chemical; Spectroscopy SC Physics; Spectroscopy GA FL581 UT WOS:A1991FL58100013 ER PT J AU JUNTTILA, ML DOMENECH, JL FRASER, GT PINE, AS AF JUNTTILA, ML DOMENECH, JL FRASER, GT PINE, AS TI MOLECULAR-BEAM OPTOTHERMAL SPECTROSCOPY OF THE 9.6-MU-M NU-14-BAND OF BENZENE SO JOURNAL OF MOLECULAR SPECTROSCOPY LA English DT Article ID FUNDAMENTAL-BAND; LASER SPECTROSCOPY; SPECTRUM; TRANSITIONS; C6H6 C1 NATL INST STANDARDS & TECHNOL,DIV MOLEC PHYS,GAITHERSBURG,MD 20874. RI Domenech, Jose/F-5561-2013 OI Domenech, Jose/0000-0001-8629-2566 NR 19 TC 34 Z9 34 U1 1 U2 1 PU ACADEMIC PRESS INC JNL-COMP SUBSCRIPTIONS PI SAN DIEGO PA 525 B ST, STE 1900, SAN DIEGO, CA 92101-4495 SN 0022-2852 J9 J MOL SPECTROSC JI J. Mol. Spectrosc. PD JUN PY 1991 VL 147 IS 2 BP 513 EP 520 DI 10.1016/0022-2852(91)90074-K PG 8 WC Physics, Atomic, Molecular & Chemical; Spectroscopy SC Physics; Spectroscopy GA FL581 UT WOS:A1991FL58100019 ER PT J AU PARK, K CHANCE, KV NOLT, IG RADOSTITZ, JV VANEK, MD JENNINGS, DA EVENSON, KM AF PARK, K CHANCE, KV NOLT, IG RADOSTITZ, JV VANEK, MD JENNINGS, DA EVENSON, KM TI PRESSURE BROADENING OF THE 2.5 THZ (HCL)-CL-35 ROTATIONAL LINE BY N2 AND O2 SO JOURNAL OF MOLECULAR SPECTROSCOPY LA English DT Article ID FAR-INFRARED SPECTROSCOPY; HCL; TEMPERATURE; WIDTHS; BAND C1 HARVARD SMITHSONIAN CTR ASTROPHYS,CAMBRIDGE,MA 02138. NASA,LANGLEY RES CTR,HAMPTON,VA 23665. NATL INST STANDARDS & TECHNOL,GAITHERSBURG,MD. RP PARK, K (reprint author), UNIV OREGON,DEPT PHYS,EUGENE,OR 97403, USA. OI Chance, Kelly/0000-0002-7339-7577 NR 9 TC 11 Z9 11 U1 0 U2 1 PU ACADEMIC PRESS INC JNL-COMP SUBSCRIPTIONS PI SAN DIEGO PA 525 B ST, STE 1900, SAN DIEGO, CA 92101-4495 SN 0022-2852 J9 J MOL SPECTROSC JI J. Mol. Spectrosc. PD JUN PY 1991 VL 147 IS 2 BP 521 EP 525 DI 10.1016/0022-2852(91)90075-L PG 5 WC Physics, Atomic, Molecular & Chemical; Spectroscopy SC Physics; Spectroscopy GA FL581 UT WOS:A1991FL58100020 ER PT J AU JACKSON, CL MCKENNA, GB AF JACKSON, CL MCKENNA, GB TI THE GLASS-TRANSITION OF ORGANIC LIQUIDS CONFINED TO SMALL PORES SO JOURNAL OF NON-CRYSTALLINE SOLIDS LA English DT Article; Proceedings Paper CT INTERNATIONAL DISCUSSION MEETING ON RELAXATION IN COMPLEX SYSTEMS CY JUN 18-29, 1990 CL CRETE, GREECE SP USN, OFF NAVAL RES, US DOE, MAX PLANCK INST POLYM RES, ELLENIC POLYM ASSOC, CHALMERS UNIV TECHNOL, EUROPEAN OFF AEROSP RES & DEV, AIR FORCE SCI RES, USA, R&D & STAND GRP, RHEOMETRICS, SUMITOMO PLAST AMER, HOECHST CELENESE RES DIV ID FORMING MICROEMULSIONS; MOLECULAR LIQUIDS; VOLUME-RECOVERY; PRESSURE; VITRIFICATION AB The glass-transition temperatures, T(g), of organic liquids confined to small pores were studied by differential scanning calorimetry (DSC). The T(g) was measured as a function of pore size in controlled pore glasses (CPG) having pore diameters in the range of 40-730 angstrom. The surface of the glass was treated with hexamethyldisilazane to promote wetting by the organic liquids studied (o-terphenyl and benzyl alcohol). Glasses formed in the pores had a lower T(g) than in the bulk and the reduction in T(g) increased as the pore size decreased. For example, the depression of the glass transition temperature, DELTA-T(g), of benzyl alcohol in 40 angstrom and 85 angstrom pores was 7.2 K and 3.1 K, respectively. The magnitude of DELTA-T(g) also depends on the material; e.g. for o-terphenyl in the 85 angstrom pores, DELTA-T(g) was 8.8 K versus 3.1 K for benzyl alcohol. In general, it was noted that DELTA-T(g) was considerably less than for the depression of the crystalline melting point, DELTA-T(m), studied in related work. For example, for benzyl alcohol in the 85 angstrom pores, DELTA-T(m) was approximately 25 K and DELTA-T(g) was approximately 3 K. RP JACKSON, CL (reprint author), NATL INST STAND & TECHNOL,DIV POLYMERS,GAITHERSBURG,MD 20899, USA. RI McKenna, Gregory/O-1134-2013; OI McKenna, Gregory/0000-0002-5676-9930; Jackson, Catheryn/0000-0003-1611-3926 NR 21 TC 323 Z9 323 U1 3 U2 66 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0022-3093 J9 J NON-CRYST SOLIDS JI J. Non-Cryst. Solids PD JUN PY 1991 VL 131 BP 221 EP 224 DI 10.1016/0022-3093(91)90305-P PN 1 PG 4 WC Materials Science, Ceramics; Materials Science, Multidisciplinary SC Materials Science GA FV574 UT WOS:A1991FV57400043 ER PT J AU MCKENNA, GB SANTORE, MM LEE, A DURAN, RS AF MCKENNA, GB SANTORE, MM LEE, A DURAN, RS TI AGING IN GLASSES SUBJECTED TO LARGE STRESSES AND DEFORMATIONS SO JOURNAL OF NON-CRYSTALLINE SOLIDS LA English DT Article; Proceedings Paper CT INTERNATIONAL DISCUSSION MEETING ON RELAXATION IN COMPLEX SYSTEMS CY JUN 18-29, 1990 CL CRETE, GREECE SP USN, OFF NAVAL RES, US DOE, MAX PLANCK INST POLYM RES, ELLENIC POLYM ASSOC, CHALMERS UNIV TECHNOL, EUROPEAN OFF AEROSP RES & DEV, AIR FORCE SCI RES, USA, R&D & STAND GRP, RHEOMETRICS, SUMITOMO PLAST AMER, HOECHST CELENESE RES DIV AB Physical aging studies near the conventional glass transition temperature T(g) were made using a model epoxy glass. Non-linear viscoelastic responses were measured after quenching the samples from above T(g) to below it. The physical aging response in creep in simple extension was studied as a function of stress magnitude and in stress relaxation in torsion as a function of deformation magnitude. In each test the time, t*, for the aging time shift factor to approach a constant value was determined and found to be independent of the stress or deformation magnitude. The torsional experiments were performed in a torsional dilatometer and the volume recovery response during the physical aging experiment was measured in addition to the torque response. It was found that the underlying volume recovery kinetics were not changed by the mechanical stimuli, i.e. were independent of the applied deformation. These results are interpreted to mean that large mechanical stimuli do not alter the underlying thermodynamic state of the glass and aging is not 'erased' by the large stresses or deformations. C1 LOCKHEED AERONAUT SYST CO,LOS ANGELES,CA 91520. UNIV FLORIDA,GAINESVILLE,FL 32611. RP MCKENNA, GB (reprint author), NATL INST STAND & TECHNOL,DIV POLYMERS,GAITHERSBURG,MD 20899, USA. RI McKenna, Gregory/O-1134-2013 OI McKenna, Gregory/0000-0002-5676-9930 NR 14 TC 21 Z9 21 U1 0 U2 5 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0022-3093 J9 J NON-CRYST SOLIDS JI J. Non-Cryst. Solids PD JUN PY 1991 VL 131 BP 497 EP 504 DI 10.1016/0022-3093(91)90347-9 PN 1 PG 8 WC Materials Science, Ceramics; Materials Science, Multidisciplinary SC Materials Science GA FV574 UT WOS:A1991FV57400085 ER PT J AU MCKENNA, GB ANGELL, CA RENDELL, RW MOYNIHAN, CT KOVACS, AJ MCKENNA, GB HUTCHINSON, JM OGUNI, M OREILLY, J STRUIK, L HODGE, IM BAUWENS, JC OLEYNICK, E REKHSON, S WILLIAMS, G MATSUOKA, S AF MCKENNA, GB ANGELL, CA RENDELL, RW MOYNIHAN, CT KOVACS, AJ MCKENNA, GB HUTCHINSON, JM OGUNI, M OREILLY, J STRUIK, L HODGE, IM BAUWENS, JC OLEYNICK, E REKHSON, S WILLIAMS, G MATSUOKA, S TI THE PHENOMENOLOGY AND MODELS OF THE KINETICS OF VOLUME AND ENTHALPY IN THE GLASS-TRANSITION RANGE SO JOURNAL OF NON-CRYSTALLINE SOLIDS LA English DT Discussion RP MCKENNA, GB (reprint author), NATL INST STAND & TECHNOL,DIV POLYMERS,GAITHERSBURG,MD 20899, USA. RI McKenna, Gregory/O-1134-2013 OI McKenna, Gregory/0000-0002-5676-9930 NR 2 TC 14 Z9 14 U1 0 U2 22 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0022-3093 J9 J NON-CRYST SOLIDS JI J. Non-Cryst. Solids PD JUN PY 1991 VL 131 BP 528 EP 536 DI 10.1016/0022-3093(91)90353-8 PN 1 PG 9 WC Materials Science, Ceramics; Materials Science, Multidisciplinary SC Materials Science GA FV574 UT WOS:A1991FV57400091 ER PT J AU NORTON, SJ AF NORTON, SJ TI RECONSTRUCTING STRATIFIED FLUID-FLOW FROM RECIPROCAL SCATTERING MEASUREMENTS SO JOURNAL OF THE ACOUSTICAL SOCIETY OF AMERICA LA English DT Article ID INVERSION AB This paper shows how an inversion formula can be derived for reconstructing the magnitude and direction of stratified fluid flow from two scattering measurements. The measurements are recorded by transmitting an acoustic pulse from a source below the region of stratified flow and then recording the scattered wave at another point horizontally displaced from the source. A second measurement is performed with the source and receiver interchanged and the result is subtracted from the first scattering measurement. This difference is, within the Born approximation, independent of scattering that arises from stationary inhomogeneities and thus solely sensitive to scattering due to flow. As a by-product, the sum of the two scattering measurements with source and receiver interchanged yields a quantity sensitive only to scattering from stationary inhomogeneities. This allows the stationary inhomogeneities to be recovered independently of flow. RP NORTON, SJ (reprint author), NATL INST STAND & TECHNOL,GAITHERSBURG,MD 20899, USA. NR 8 TC 6 Z9 6 U1 0 U2 0 PU AMER INST PHYSICS PI WOODBURY PA CIRCULATION FULFILLMENT DIV, 500 SUNNYSIDE BLVD, WOODBURY, NY 11797-2999 SN 0001-4966 J9 J ACOUST SOC AM JI J. Acoust. Soc. Am. PD JUN PY 1991 VL 89 IS 6 BP 2567 EP 2572 DI 10.1121/1.400695 PG 6 WC Acoustics; Audiology & Speech-Language Pathology SC Acoustics; Audiology & Speech-Language Pathology GA FP536 UT WOS:A1991FP53600007 ER PT J AU XU, PC DATTA, SK AF XU, PC DATTA, SK TI CHARACTERIZATION OF FIBER MATRIX INTERFACE BY GUIDED-WAVES - AXISYMMETRICAL CASE SO JOURNAL OF THE ACOUSTICAL SOCIETY OF AMERICA LA English DT Article ID OBLIQUELY INCIDENT; CYLINDER; PROPAGATION; SCATTERING; PLATES AB A hybrid method combining the finite-element and eigenfunction expansions is proposed to study the guided waves in composite cylinders. This method is shown to be flexible in modeling generally anisotropic cylinders and computationally efficient. However, most of the analysis is confined to the case of a transversely isotropic cylindrical core surrounded by coaxial isotropic cylinders. The object is to model uniaxial fiber-reinforced materials with interface zones between the fiber (which is anisotropic) and the matrix (which is isotropic). Numerical results are presented for the axisymmetric case for a graphite fiber in magnesium and epoxy matrices. In aprticular, the measurable and analyzable effects of imperfect bonding are investigated. The reduction of bond stiffness is found to have significant effect on the leaky waves. C1 UNIV COLORADO,NOAA,COOPERAT INST RES ENVIRONM SCI,BOULDER,CO 80309. RP XU, PC (reprint author), UNIV COLORADO,DEPT MECH ENGN,BOULDER,CO 80309, USA. NR 31 TC 29 Z9 34 U1 1 U2 1 PU AMER INST PHYSICS PI WOODBURY PA CIRCULATION FULFILLMENT DIV, 500 SUNNYSIDE BLVD, WOODBURY, NY 11797-2999 SN 0001-4966 J9 J ACOUST SOC AM JI J. Acoust. Soc. Am. PD JUN PY 1991 VL 89 IS 6 BP 2573 EP 2583 DI 10.1121/1.400696 PG 11 WC Acoustics; Audiology & Speech-Language Pathology SC Acoustics; Audiology & Speech-Language Pathology GA FP536 UT WOS:A1991FP53600008 ER PT J AU LATHABAI, S RODEL, J LAWN, BR AF LATHABAI, S RODEL, J LAWN, BR TI CYCLIC FATIGUE FROM FRICTIONAL DEGRADATION AT BRIDGING GRAINS IN ALUMINA SO JOURNAL OF THE AMERICAN CERAMIC SOCIETY LA English DT Article DE FATIGUE; FRICTION; DEGRADATION; GRAINS; BRIDGING ID FRACTURE-RESISTANCE MECHANISM; CRACK-PROPAGATION; CERAMICS; BEHAVIOR; TEMPERATURE; COMPOSITES; MODEL AB Tension-tension cyclic loading tests have been conducted on a coarse-grained alumina ceramic that exhibits toughness-curve behavior by grain-interlock bridging. Fatigue effects are observed in the regions of both short cracks, using indentation flaws, and long cracks, using compact-tension specimens. A true mechanical fatigue effect is demonstrated by running the tests below the static fatigue limit. A custommade device for in situ observation of crack propagation in the scanning electron microscope enables us to identify bridge degradation as a cause of the fatigue process. "Wear" debris cumulates at the sliding intergranular frictional contact points, indicating a loss of traction at the junction. The basis of a fracture mechanics model describing the effect of this frictional degradation in reducing crack-tip shielding is outlined and fitted to the data. It is suggested that the bridge degradation fatigue mechanism may be widespread in polycrystalline ceramics with pronounced toughness curves. C1 NBS,DEPT CERAM,GAITHERSBURG,MD 20899. NR 36 TC 131 Z9 131 U1 0 U2 11 PU AMER CERAMIC SOC PI WESTERVILLE PA 735 CERAMIC PLACE, PO BOX 6136, WESTERVILLE, OH 43081-6136 SN 0002-7820 J9 J AM CERAM SOC JI J. Am. Ceram. Soc. PD JUN PY 1991 VL 74 IS 6 BP 1340 EP 1348 DI 10.1111/j.1151-2916.1991.tb04109.x PG 9 WC Materials Science, Ceramics SC Materials Science GA FQ928 UT WOS:A1991FQ92800024 ER PT J AU CROUCH, DD ANDERSON, DZ AF CROUCH, DD ANDERSON, DZ TI DYNAMICS OF AN OPTICAL RING CIRCUIT HAVING PHOTOREFRACTIVE GAIN AND LOSS AND HISTORY-DEPENDENT FEEDBACK SO JOURNAL OF THE OPTICAL SOCIETY OF AMERICA B-OPTICAL PHYSICS LA English DT Article ID BISTABILITY; OSCILLATION; RESONATOR; MEMORY AB An optical ring circuit is considered in which gain, loss, and feedback are provided by refractive-index gratings in photorefractive crystals. The photorefractive feedback coupling element, which replaces an ordinary mirror, is assumed to be much slower than either the gain or the loss. As a result, the state of the photorefractive mirror depends on past states of the circuit; that is, the photorefractive mirror has a memory. The system's behavior is then determined by the relative speeds of the gain and the loss. When their speeds are roughly equal, the system exhibits both ordinary bistability and history-dependent bistability, whose character changes as the system evolves. Graphic techniques aid in the understanding of the nature of both types of bistability. When the gain is significantly faster than the loss, the system exhibits one of three varieties of self-pulsing: pure self-pulsing, interrupted self-pulsing, or delayed self-pulsing. C1 UNIV COLORADO,NATL INST STAND & TECHNOL,JOINT INST LAB ASTROPHYS,BOULDER,CO 80302. RP CROUCH, DD (reprint author), UNIV COLORADO,BOULDER,CO 80309, USA. NR 18 TC 4 Z9 4 U1 0 U2 1 PU OPTICAL SOC AMER PI WASHINGTON PA 2010 MASSACHUSETTS AVE NW, WASHINGTON, DC 20036 SN 0740-3224 J9 J OPT SOC AM B JI J. Opt. Soc. Am. B-Opt. Phys. PD JUN PY 1991 VL 8 IS 6 BP 1315 EP 1325 DI 10.1364/JOSAB.8.001315 PG 11 WC Optics SC Optics GA FP541 UT WOS:A1991FP54100018 ER PT J AU STONE, GS BUSCH, WS AF STONE, GS BUSCH, WS TI DEEP OCEAN SCIENCE AND FACILITY NEEDS SO MARINE TECHNOLOGY SOCIETY JOURNAL LA English DT Article AB Since the 1960s, the United States has lost the ability to send a manned submersible system to the deepest ocean depths (11,000 meters). Today, the deepest diving U.S. submersible is the Navy Sea Cliff (6,000 meter) and the deepest diving civilian scientific submersible is Alvin (4,000 meter). In order to ascertain a first approximation of what the major science needs are in the ocean from 4,000 meters to 11,000 meters, questionnaires were sent to 150 submersible scientists. Sixty-two questionnaires were returned and responses indicate research needs in primarily two depth ranges: from 5,000 to 6,000 meters and from 10,000 to 11,000 meters. Most proposed dive locations are in the Pacific Ocean and topics of investigation include hydrothermal vent geology, chemistry, and biology; deep-sea mineralization; and deep-sea protozoan and metazoan biology. The technology required to go to that depth exists today. In order to bring this technology into use, the scientific community must continue to identify specific scientific projects for these deep regions, their respective national importance and their cost benefits for the United States. C1 NOAA,NATL UNDERSEA RES PROGRAM,SILVER SPRING,MD 20910. EXECUT OFF PRESIDENT US,OFF SCI & TECHNOL POLICY,WASHINGTON,DC. NR 10 TC 3 Z9 3 U1 0 U2 0 PU MARINE TECHNOLOGY SOC INC PI WASHINGTON PA 1828 L ST NW 9TH FLOOR, WASHINGTON, DC 20036 SN 0025-3324 J9 MAR TECHNOL SOC J JI Mar. Technol. Soc. J. PD SUM PY 1991 VL 25 IS 2 BP 14 EP 21 PG 8 WC Engineering, Ocean; Oceanography SC Engineering; Oceanography GA GC686 UT WOS:A1991GC68600002 ER PT J AU MCCORMICK, MJ PICKETT, RL MILLER, GS AF MCCORMICK, MJ PICKETT, RL MILLER, GS TI A FIELD-EVALUATION OF NEW SATELLITE-TRACKED BUOYS - A LORAN-C POSITION RECORDING AND A SONOBUOY TYPE DRIFTER SO MARINE TECHNOLOGY SOCIETY JOURNAL LA English DT Article AB Two types of satellite-tracked, drifting data-buoys were tested in Lake Michigan for twenty days. One type was a sonobuoy-size (0.9 m long, 12 cm diameter) buoy made by Metocean Data Systems and one was a mid-sized (1.8 m long, 20 cm diameter) buoy made by Polar Research Laboratory. The two Metocean buoys came equipped with sensors for barometric pressure, air temperature, and seven levels of water temperature from the surface down to 100 m. The Polar Research buoy was without sensors and was modified to carry a LORAN-C position-recording system. The Metocean buoy sensors compared well with those of the National Oceanic and Atmospheric Administration (NOAA) meterological buoy in the center of Lake Michigan and with the Conductivity, Temperature, Depth (CTD) data taken at the launch site. Shortly after launch, however, the bottom weight broke off one of the subsurface temperature cables on these buoys. This failure allowed the temperature cable to stream along near the surface, so that no subsurface data were obtained. The other buoy, however, provided useful subsurface data for fifteen days until its ballast weight was lost after contact with bottom. The add-on LORAN positioning on the Polar Research buoy provided more frequent and precise positions than were available from satellite tracking alone. The LORAN-C data suggest that infrequent yet large satellite positioning errors may occur and may be difficult for the user to detect. RP MCCORMICK, MJ (reprint author), NOAA,GREAT LAKES ENVIRONM RES LAB,ANN ARBOR,MI, USA. NR 10 TC 2 Z9 2 U1 0 U2 1 PU MARINE TECHNOLOGY SOC INC PI WASHINGTON PA 1828 L ST NW 9TH FLOOR, WASHINGTON, DC 20036 SN 0025-3324 J9 MAR TECHNOL SOC J JI Mar. Technol. Soc. J. PD SUM PY 1991 VL 25 IS 2 BP 29 EP 33 PG 5 WC Engineering, Ocean; Oceanography SC Engineering; Oceanography GA GC686 UT WOS:A1991GC68600004 ER PT J AU BLASKOVIC, M DAVIES, R SNIDER, JB AF BLASKOVIC, M DAVIES, R SNIDER, JB TI DIURNAL-VARIATION OF MARINE STRATOCUMULUS OVER SAN-NICOLAS-ISLAND DURING JULY 1987 SO MONTHLY WEATHER REVIEW LA English DT Article ID MIXED LAYER MODEL; RADIATION; CLOUDS; LIQUID AB Surface measurements made at San Nicolas Island during the intensive field observation marine stratocumulus phase of the First International Statellite Cloud Climatology Program Regional Experiment, July 1987, are analyzed to retrieve the average diurnal variation of marine stratocumulus and related surface variables. Cloud thickness and integrated liquid-water content show a clear decrease during the day from sunrise to sunset, increasing thereafter. The average liquid-water density in the cloud is closely related to the cloud thickness, decreasing as the cloud thickness decreases. The cloud-base height has a diurnal range of 150 +/- 30 m, rising from sunrise till midafternoon. The cloud-top height has a similar diurnal range of 130 +/- 30 m, but the main descent occurs in the late afternoon. Surface air temperature also increases at sunrise, directly in phase with the cloud-base lifting, and has a diurnal range of 2-degrees-C. The diurnal behavior of the cloud base appears to be consistent with model-predicted uncoupling of the cloud layer and the subcloud layer as the turbulent flux of moisture is inhibited by solar heating near the cloud base. Similarly, variation in surface air temperature is consistent with the inhibition of the turbulent flux of heat between the two layers, shielding the surface from the effect of longwave cooling from the cloud top. The variation in cloud-top height, however, does not appear to be readily explainable by present diurnal models. C1 MCGILL UNIV, DEPT METEOROL, 805 SHERBROOKE ST W, MONTREAL H3A 2K6, QUEBEC, CANADA. NOAA, ENVIRONM RES LABS, WAVE PROPAGAT LAB, BOULDER, CO 80303 USA. RI Davies, Roger/D-4296-2009 OI Davies, Roger/0000-0002-2991-0409 NR 19 TC 48 Z9 48 U1 1 U2 3 PU AMER METEOROLOGICAL SOC PI BOSTON PA 45 BEACON ST, BOSTON, MA 02108-3693 USA SN 0027-0644 EI 1520-0493 J9 MON WEATHER REV JI Mon. Weather Rev. PD JUN PY 1991 VL 119 IS 6 BP 1469 EP 1478 DI 10.1175/1520-0493(1991)119<1469:DVOMSO>2.0.CO;2 PG 10 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA FR466 UT WOS:A1991FR46600008 ER PT J AU DOSWELL, CA BARNES, SL AF DOSWELL, CA BARNES, SL TI THE THEORETICAL, DISCRETE, AND ACTUAL RESPONSE OF THE BARNES OBJECTIVE ANALYSIS SCHEME FOR ONE-DIMENSIONAL AND 2-DIMENSIONAL FIELDS - COMMENTS SO MONTHLY WEATHER REVIEW LA English DT Note C1 NOAA,ENVIRONM RES LABS,FORECAST SYST LAB,NORMAN,OK 73069. RP DOSWELL, CA (reprint author), NOAA,ENVIRONM RES LABS,NATL SEVERE STORMS LAB,1313 HALLEY CIRCLE,NORMAN,OK 73069, USA. RI Doswell III, Charles/E-7662-2010 NR 4 TC 1 Z9 1 U1 0 U2 0 PU AMER METEOROLOGICAL SOC PI BOSTON PA 45 BEACON ST, BOSTON, MA 02108-3693 SN 0027-0644 J9 MON WEATHER REV JI Mon. Weather Rev. PD JUN PY 1991 VL 119 IS 6 BP 1490 EP 1492 DI 10.1175/1520-0493(1991)119<1490:COTDAA>2.0.CO;2 PG 3 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA FR466 UT WOS:A1991FR46600010 ER PT J AU COPLEY, JRD AF COPLEY, JRD TI TRANSMISSION PROPERTIES OF A COUNTER-ROTATING PAIR OF DISK CHOPPERS SO NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH SECTION A-ACCELERATORS SPECTROMETERS DETECTORS AND ASSOCIATED EQUIPMENT LA English DT Article AB Counter-rotating pairs of disk choppers are used to provide pulsed neutron beams for thermal neutron scattering experiments. An important advantage of this type of device, compared with the single disk chopper, is that each disk can be equipped with several slots. A choice of slot widths is then made possible, simply by changing the relative phasing of the two disks. The resolution of an instrument with counter-rotating chopper pairs can therefore be altered without having to modify the incident wavelength or the speed of the choppers. A potential problem, when there are several slots in each disk, is that there will be "cross talk", i.e. neutrons will be transmitted by a pair of slots other than the intended combination. We examine the transmission properties of a counter-rotating pair of choppers, and describe methods to determine whether or not cross talk can occur. An important conclusion is that the axial separation between the two choppers must be included in the analysis; this separation, which is generally small (of order several cm), significantly increases the potential for unwanted cross talk. We briefly discuss the implications of cross talk in the design of a high resolution time-of-flight spectrometer. RP COPLEY, JRD (reprint author), NATL INST STAND & TECHNOL,MAT SCI & ENGN LAB,GAITHERSBURG,MD 20899, USA. NR 11 TC 8 Z9 8 U1 0 U2 3 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0168-9002 J9 NUCL INSTRUM METH A JI Nucl. Instrum. Methods Phys. Res. Sect. A-Accel. Spectrom. Dect. Assoc. Equip. PD JUN 1 PY 1991 VL 303 IS 2 BP 332 EP 341 DI 10.1016/0168-9002(91)90799-V PG 10 WC Instruments & Instrumentation; Nuclear Science & Technology; Physics, Nuclear; Physics, Particles & Fields SC Instruments & Instrumentation; Nuclear Science & Technology; Physics GA FR965 UT WOS:A1991FR96500010 ER PT J AU OSTENSO, NA METALNIKOV, AP IMEREKOV, BI AF OSTENSO, NA METALNIKOV, AP IMEREKOV, BI TI A HISTORY OF USSR-US COOPERATION IN OCEAN RESEARCH SO OCEANUS LA English DT Article C1 STATE COMM HYDROL & METEOROL,MOSCOW,USSR. USSR STATE COMM SCI & TECHNOL,DEPT OCEANOG,MOSCOW,USSR. RP OSTENSO, NA (reprint author), NOAA,OCEAN & ATMOSPHER RES,WASHINGTON,DC 20230, USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU WOODS HOLE OCEANOGRAPHIC INST PI WOODS HOLE PA OCEANUS MAGAZINE, WOODS HOLE, MA 02543 SN 0029-8182 J9 OCEANUS JI Oceanus PD SUM PY 1991 VL 34 IS 2 BP 87 EP 91 PG 5 WC Oceanography SC Oceanography GA GE602 UT WOS:A1991GE60200016 ER PT J AU ANDERSON, DZ MIZRAHI, V SIPE, JE AF ANDERSON, DZ MIZRAHI, V SIPE, JE TI MODEL FOR 2ND-HARMONIC GENERATION IN GLASS OPTICAL FIBERS BASED ON ASYMMETRIC PHOTOELECTRON EMISSION FROM DEFECT SITES SO OPTICS LETTERS LA English DT Article ID FIELD AB We present a self-consistent calculation of anomalous second-harmonic generation in glass optical fibers. Quantum interference between multiphoton absorption processes leads to asymmetric photoelectric emission from defects, creating a spatially periodic space-charge electric field. The second harmonic is found to grow exponentially along the fiber, then saturate to a maximum value proportional to the square of the fundamental intensity. The predicted conversion efficiency is in reasonable agreement with experiments. C1 UNIV COLORADO,NATL INST STAND & TECHNOL,JOINT INST LAB ASTROPHYS,BOULDER,CO 80302. UNIV ARIZONA,CTR OPT SCI,TUCSON,AZ 85721. UNIV TORONTO,DEPT PHYS,TORONTO M5S 1A7,ONTARIO,CANADA. RP ANDERSON, DZ (reprint author), UNIV COLORADO,DEPT PHYS,BOULDER,CO 80309, USA. RI Sipe, John/B-4668-2014 NR 20 TC 105 Z9 108 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 JUN 1 PY 1991 VL 16 IS 11 BP 796 EP 798 DI 10.1364/OL.16.000796 PG 3 WC Optics SC Optics GA FP178 UT WOS:A1991FP17800006 PM 19776788 ER PT J AU WEVERKA, RT WAGNER, K SAFFMAN, M AF WEVERKA, RT WAGNER, K SAFFMAN, M TI FULLY INTERCONNECTED, 2-DIMENSIONAL NEURAL ARRAYS USING WAVELENGTH-MULTIPLEXED VOLUME HOLOGRAMS SO OPTICS LETTERS LA English DT Article ID ASSOCIATIVE-MEMORY; MODEL; NETWORKS AB We present a compact method to provide independent weighted interconnections between every pixel in a two-dimensional input array and every pixel in a two-dimensional output array. The two input dimensions and two output dimensions are connected by a four-dimensional weight matrix consisting of wavelength-multiplexed volume holograms that use cryogenic spectral hole burning in a single holographic element. C1 UNIV COLORADO,NATL SCI FDN,ENGN RES CTR OPTOELECTR COMP SYST,BOULDER,CO 80309. UNIV COLORADO,DEPT PHYS,BOULDER,CO 80309. UNIV COLORADO,NATL INST STAND & TECHNOL,JOINT INST LAB ASTROPHYS,BOULDER,CO 80302. RP WEVERKA, RT (reprint author), UNIV COLORADO,DEPT ELECT & COMP ENGN,BOULDER,CO 80309, USA. RI Saffman, Mark/A-8120-2009 OI Saffman, Mark/0000-0001-6398-2097 NR 16 TC 9 Z9 9 U1 0 U2 0 PU OPTICAL SOC AMER PI WASHINGTON PA 2010 MASSACHUSETTS AVE NW, WASHINGTON, DC 20036 SN 0146-9592 J9 OPT LETT JI Opt. Lett. PD JUN 1 PY 1991 VL 16 IS 11 BP 826 EP 828 DI 10.1364/OL.16.000826 PG 3 WC Optics SC Optics GA FP178 UT WOS:A1991FP17800016 PM 19776798 ER PT J AU CALEDONIA, GE KRECH, RH WILKERSON, TD TAYLOR, RL BIRNBAUM, G AF CALEDONIA, GE KRECH, RH WILKERSON, TD TAYLOR, RL BIRNBAUM, G TI COLLISION-INDUCED EMISSION IN THE FUNDAMENTAL VIBRATION-ROTATION BAND OF H2 SO PHYSICAL REVIEW A LA English DT Article ID LINESHAPE ANALYSIS; INDUCED SPECTRA; H-2; TEMPERATURES; H2-HE; GASES AB Measurements of collision-induced emission in the fundamental vibration-rotation band of hydrogen are presented for argon, xenon, and neon collision partners. These absolute, spectrally resolved infrared measurements were performed at high densities behind reflected shock waves over the temperature range of 900-3400 K. The emission was found to be dominated by Q-branch transitions at high temperature due primarily to the dipole moment induced by the overlap between the electron clouds of the collision pair. The strength of this interaction was evaluated from the data and compared with similar evaluations determined from low-temperature absorption studies. C1 UNIV MARYLAND,INST PHYS SCI & TECHNOL,COLLEGE PK,MD 20742. CVD INC,WOBURN,MA 01801. NIST,GAITHERSBURG,MD 20899. RP CALEDONIA, GE (reprint author), PHYS SCI INC,ANDOVER,MA 01810, USA. NR 28 TC 8 Z9 8 U1 2 U2 4 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 1050-2947 J9 PHYS REV A JI Phys. Rev. A PD JUN 1 PY 1991 VL 43 IS 11 BP 6010 EP 6017 DI 10.1103/PhysRevA.43.6010 PG 8 WC Optics; Physics, Atomic, Molecular & Chemical SC Optics; Physics GA FQ056 UT WOS:A1991FQ05600031 ER PT J AU RAHN, LA FARROW, RL ROSASCO, GJ AF RAHN, LA FARROW, RL ROSASCO, GJ TI MEASUREMENT OF THE SELF-BROADENING OF THE H2 Q(0-5) RAMAN TRANSITIONS FROM 295 TO 1000 K SO PHYSICAL REVIEW A LA English DT Article ID ROTATIONAL ENERGY-TRANSFER; DOUBLE-RESONANCE MEASUREMENTS; FIELD-INDUCED SPECTRUM; Q-BRANCH; MOLECULAR-HYDROGEN; LINE-PROFILES; TEMPERATURE-DEPENDENCE; INELASTIC RATES; LAW ANALYSIS; COLLISIONS AB High-resolution inverse Raman spectroscopy has been used to measure the self-broadening coefficients of the Raman Q-branch transitions in pure (natural) hydrogen. Measurements of six lines [Q(0)-Q(5)] were made at pressures from 2 to 50 atm and from 295 to 1000 K. The dependence of the derived broadening coefficients on temperature and rotational quantum number is analyzed using the energy-corrected sudden scaling law [A. E. DePristo, J. Chem. Phys. 73, 2145 (1980)]. We discuss three models for the J dependence of the pure-vibrational dephasing and find that models with little or no J dependence in the pure-vibrational dephasing are preferred. C1 NIST,CTR CHEM TECHNOL,GAITHERSBURG,MD 20899. RP RAHN, LA (reprint author), SANDIA NATL LABS,COMBUST RES FACIL,LIVERMORE,CA 94551, USA. OI Rahn, Larry/0000-0002-4793-1158 NR 62 TC 65 Z9 65 U1 0 U2 9 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 1050-2947 J9 PHYS REV A JI Phys. Rev. A PD JUN 1 PY 1991 VL 43 IS 11 BP 6075 EP 6088 DI 10.1103/PhysRevA.43.6075 PG 14 WC Optics; Physics, Atomic, Molecular & Chemical SC Optics; Physics GA FQ056 UT WOS:A1991FQ05600040 ER PT J AU LYKKE, KR MURRAY, KK LINEBERGER, WC AF LYKKE, KR MURRAY, KK LINEBERGER, WC TI THRESHOLD PHOTODETACHMENT OF H- SO PHYSICAL REVIEW A LA English DT Article ID COLOR-CENTER; RESOLUTION; LASER; NACL AB The electron affinities of atomic hydrogen and deuterium have been determined by tunable-laser threshold-photodetachment spectroscopy: the electron affinities of H (F = 0) and D (F = 1/2) are 6082.99 +/- 0.15 and 6086.2 +/- 0.6 cm-1, respectively. The value for H is a 20-fold improvement over previous experimental determinations. C1 UNIV COLORADO,NIST,JOINT INST LAB ASTROPHYS,BOULDER,CO 80309. UNIV COLORADO,DEPT CHEM & BIOCHEM,BOULDER,CO 80309. OI Murray, Kermit/0000-0002-4976-2263 NR 22 TC 166 Z9 166 U1 2 U2 12 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 1050-2947 J9 PHYS REV A JI Phys. Rev. A PD JUN 1 PY 1991 VL 43 IS 11 BP 6104 EP 6107 DI 10.1103/PhysRevA.43.6104 PG 4 WC Optics; Physics, Atomic, Molecular & Chemical SC Optics; Physics GA FQ056 UT WOS:A1991FQ05600044 ER PT J AU PAN, LW TAYLOR, KT CLARK, CW AF PAN, LW TAYLOR, KT CLARK, CW TI PERTURBATIVE CALCULATION OF THE AC STARK-EFFECT BY THE COMPLEX ROTATION METHOD SO PHYSICAL REVIEW A LA English DT Article ID HIGH-HARMONIC GENERATION; QUANTUM-DEFECT THEORY; MULTIPHOTON IONIZATION; ATOMIC-HYDROGEN; LASER FIELDS; HIGH-ORDER; RESONANCES; THRESHOLD AB We have calculated the high-order ac Stark effect for the ground state of atomic hydrogen by applying Rayleigh-Schrodinger perturbation theory to a complex-rotated Hamiltonian. We present results for the level-shift and multiphoton-ionization rate, which include effects of above-threshold ionization. Our results indicate that the field intensities at which high-order contributions become dominant can be as low as 10(11) W/cm2, much lower than is commonly expected. A systematic treatment of the frequency dependence of the perturbation coefficients in the vicinity of multiphoton resonances and ionization thresholds is provided by reference to the analytical properties of the Coulomb Green's function. C1 UNIV MARYLAND, INST PHYS SCI & TECHNOL, COLLEGE PK, MD 20742 USA. UNIV LONDON, ROYAL HOLLOWAY & BREDFORD NEW COLL, DEPT MATH, EGHAM TW20 0EX, SURREY, ENGLAND. NIST, CTR ATOM MOLEC & OPT PHYS, GAITHERSBURG, MD 20899 USA. RI Pan, Laura/A-9296-2008; Clark, Charles/A-8594-2009 OI Pan, Laura/0000-0001-7377-2114; Clark, Charles/0000-0001-8724-9885 NR 26 TC 3 Z9 3 U1 0 U2 2 PU AMER PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 2469-9926 EI 2469-9934 J9 PHYS REV A JI Phys. Rev. A PD JUN 1 PY 1991 VL 43 IS 11 BP 6272 EP 6283 DI 10.1103/PhysRevA.43.6272 PG 12 WC Optics; Physics, Atomic, Molecular & Chemical SC Optics; Physics GA FQ056 UT WOS:A1991FQ05600062 ER PT J AU ARMSTRONG, DJ WESTLING, LA SMITH, SJ AF ARMSTRONG, DJ WESTLING, LA SMITH, SJ TI RELATIVE MEASUREMENT OF THE PHOTOIONIZATION CROSS-SECTION OF THE 7D5/2 STATE OF CESIUM SO PHYSICAL REVIEW A LA English DT Note ID 7D EXCITED-STATE; PHOTOIONISATION AB We have carried out a relative measurement of the total photoionization cross section of the excited 7D5/2 state of cesium for photoelectron energies in the range 0.103-0.127 Ry above the ionization threshold. Separate measurements were made using two different combinations of laser sources to populate and photoionize the 7D5/2 state. The first measurement was made with a cw diode laser and two pulsed dye lasers, while the second was made with three pulsed dye lasers. The measured cross section was found to vary slowly within experimental uncertainty over this energy range but was otherwise featureless. This result disagrees with the cross section predicted by a Hartree-Slater calculation [J. Lahiri and S. T. Manson, Phys. Rev. A 33, 3151 (1986)], which displayed a deep minimum in this spectral region. RP ARMSTRONG, DJ (reprint author), UNIV COLORADO,NIST,JOINT INST LAB ASTROPHYS,BOULDER,CO 80309, USA. NR 9 TC 2 Z9 2 U1 0 U2 1 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 1050-2947 J9 PHYS REV A JI Phys. Rev. A PD JUN 1 PY 1991 VL 43 IS 11 BP 6398 EP 6400 DI 10.1103/PhysRevA.43.6398 PG 3 WC Optics; Physics, Atomic, Molecular & Chemical SC Optics; Physics GA FQ056 UT WOS:A1991FQ05600077 ER PT J AU CRESPI, VH COHEN, ML PENN, DR AF CRESPI, VH COHEN, ML PENN, DR TI ANHARMONIC PHONONS AND THE ISOTOPE EFFECT IN SUPERCONDUCTIVITY SO PHYSICAL REVIEW B LA English DT Article ID OXYGEN ISOTOPE; YBA2CU3O7 AB Anharmonic interionic potentials are examined in an Einstein model to study the unusual isotope-effect exponents for the high-T(c) oxides. The mass dependences of the electron-phonon coupling constant-lambda and the average phonon frequency square-root are computed from weighted sums over the oscillator levels. The isotope-effect exponent is depressed below 1/2 by either a double-well potential or a potential with positive quadratic and quartic parts. Numerical solutions of Schrodinger's equation for double-well potentials produce lambda's in the range 1.5-4 for a material with a vanishing isotope-effect parameter-alpha. However, low phonon frequencies limit T(c) to roughly 15 K. A negative quartic perturbation to a harmonic well can increase-alpha above 1/2. In the extreme-strong-coupling limit, alpha is 1/2, regardless of anharmonicity. C1 UNIV CALIF BERKELEY LAWRENCE BERKELEY LAB,DIV MAT SCI,BERKELEY,CA 94720. NATL INST STAND & TECHNOL,GAITHERSBURG,MD 20899. RP CRESPI, VH (reprint author), UNIV CALIF BERKELEY,DEPT PHYS,BERKELEY,CA 94720, USA. OI Crespi, Vincent/0000-0003-3846-3193 NR 14 TC 31 Z9 31 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 JUN 1 PY 1991 VL 43 IS 16 BP 12921 EP 12924 DI 10.1103/PhysRevB.43.12921 PN A PG 4 WC Physics, Condensed Matter SC Physics GA FP631 UT WOS:A1991FP63100027 ER PT J AU TSUI, F FLYNN, CP SALAMON, MB ERWIN, RW BORCHERS, JA RHYNE, JJ AF TSUI, F FLYNN, CP SALAMON, MB ERWIN, RW BORCHERS, JA RHYNE, JJ TI ANISOTROPIC MAGNETIC-BEHAVIOR IN DY/Y FILMS AND SUPERLATTICES SO PHYSICAL REVIEW B LA English DT Article ID RARE-EARTH SUPERLATTICES; Y SUPERLATTICES; SURFACE; ORDER AB By neutron diffraction we show that superlattices of Dy and Y grown by molecular-beam epitaxy along the hcp b axis exhibit little magnetic coupling between successive Dy layers, even for Y spacers as thin as 9 atomic planes (26 angstrom). Previous studies of Dy/Y superlattices grown along the hcp c axis established that long-range three-dimensional helimagnetic ordering takes place even through Y spacer layers as thick as 120 angstrom. This highly anisotropic coupling behavior is shown to have its origin in nearly-two-dimensional nesting features of the Y and Dy Fermi surfaces. Nesting along the c axis gives rise to sharp peaks along c in the wave-vector-dependent magnetic susceptibility, and causes the exchange coupling to exhibit long-range oscillations in real space. The lack of nesting features along the b axis leaves a rapid exponential decay of the exchange interaction with spin separation. From magnetic measurements by superconducting-quantum-interference-device magnetometry on b-axis superlattices and films, we deduce that the first-order ferromagnetic transition of Dy is suppressed, and that the critical field required to produce the ferromagnetic alignment is much higher than the c-axis counterpart. This difference arises from anisotropy of the energy balance of the system. The magnetic coherence in b-axis superlattices and films is anisotropic and exhibits an unusual temperature dependence. C1 UNIV ILLINOIS, MAT RES LAB, URBANA, IL 61801 USA. NATL INST STAND & TECHNOL, GAITHERSBURG, MD 20899 USA. RP UNIV ILLINOIS, DEPT PHYS, 1110 W GREEN ST, URBANA, IL 61801 USA. NR 34 TC 11 Z9 11 U1 0 U2 0 PU AMER PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 2469-9950 EI 2469-9969 J9 PHYS REV B JI Phys. Rev. B PD JUN 1 PY 1991 VL 43 IS 16 BP 13320 EP 13330 DI 10.1103/PhysRevB.43.13320 PN B PG 11 WC Physics, Condensed Matter SC Physics GA FP632 UT WOS:A1991FP63200009 ER PT J AU STEPHENSON, GB WARBURTON, WK HALLER, W BIENENSTOCK, A AF STEPHENSON, GB WARBURTON, WK HALLER, W BIENENSTOCK, A TI REAL-TIME SMALL-ANGLE X-RAY-SCATTERING STUDY OF THE EARLY STAGE OF PHASE-SEPARATION IN THE SIO2-BAO-K2O SYSTEM SO PHYSICAL REVIEW B LA English DT Article ID SPINODAL DECOMPOSITION; B2O3-PBO-AL2O3 GLASS; IMMISCIBILITY BOUNDARIES; SYNCHROTRON RADIATION; SIO2-AL2O3 SYSTEM; INTERDIFFUSION; PREDICTION; ALLOYS AB Time-resolved small-angle x-ray scattering was used to study the early stage of phase separation in a silicate system. Scattering patterns were acquired in real time as a sample was quenched in situ from a temperature T1 in the single-phase region directly to a temperature T2 in the two-phase region and held isothermally. This was made possible by using a high-intensity synchrotron x-ray source, a fast position-sensitive detector, a sample heater capable of rapid quenches, and a sample composition chosen to give good scattering contrast and relatively slow kinetics. The composition studied, 90 mol % SiO2, 5 mol % BaO, and 5 mol % K2O, undergoes subliquidus phase separation at temperatures below 1021 K to form alkali-oxide-rich and alkali-oxide-poor amorphous phases. The temperatures used were T1 = 1074 K and T2 = 1014, 995, 970, and 950 K. While the resultant data agree qualitatively with the linearized thermodynamics of the Cahn-Hilliard-Cook (CHC) theory of spinodal decomposition (i.e., the structure factor changes exponentially with time at each wave number), they do not agree with the simple diffusive kinetics used in the CHC theory. The data are in very good agreement with a modified theory incorporating diffusion-induced-flow (DIF) kinetics, in which one considers both the generation of stress arising from unequal mobilities of the diffusing species and the relaxation of this stress through deformation. Values of the material parameters as a function of temperature obtained from fits of the DIF theory to the data are in reasonable agreement with independent measurements and estimates based on a regular-solution model. For amorphous systems in particular, these results provide direct evidence that viscous flow is the rate-limiting step for the interdiffusion of network-forming and network-modifying species over the short length scales involved in the early stage of phase separation. C1 XRAY INSTRUMENTAT ASSOCIATES, MENLO PK, CA 94025 USA. NATL INST STAND & TECHNOL, GAITHERSBURG, MD 20899 USA. STANFORD UNIV, SYNCHROTRON RADIAT LAB, STANFORD, CA 94309 USA. RP IBM CORP, DIV RES, POB 218, YORKTOWN HTS, NY 10598 USA. NR 50 TC 11 Z9 11 U1 0 U2 7 PU AMER PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 2469-9950 EI 2469-9969 J9 PHYS REV B JI Phys. Rev. B PD JUN 1 PY 1991 VL 43 IS 16 BP 13417 EP 13437 DI 10.1103/PhysRevB.43.13417 PN B PG 21 WC Physics, Condensed Matter SC Physics GA FP632 UT WOS:A1991FP63200020 ER PT J AU HILL, RJ AF HILL, RJ TI COMPARISON OF EXPERIMENT WITH A NEW THEORY OF THE TURBULENCE TEMPERATURE STRUCTURE-FUNCTION SO PHYSICS OF FLUIDS A-FLUID DYNAMICS LA English DT Article ID OPTICAL PROPAGATION; SPECTRUM AB The theory for the structure function of an advected scalar quantity in turbulent flow by Effinger and Grossmann [Phys. Fluids A 1, 1021 (1989)], is compared with data. The theoretical structure function is transformed to a spatial power spectrum, which is found to have negative values. The theory does not agree with data for the spectrum. The theory has startling differences with Batchelor's theory [J. Fluid Mech. 5, 113 (1959)] for the viscous-diffusive and viscous-convective ranges. RP HILL, RJ (reprint author), NOAA,ENVIRONM RES LABS,WAVE PROPAGAT LAB,325 BROADWAY,BOULDER,CO 80303, USA. NR 11 TC 6 Z9 6 U1 0 U2 0 PU AMER INST PHYSICS PI WOODBURY PA CIRCULATION FULFILLMENT DIV, 500 SUNNYSIDE BLVD, WOODBURY, NY 11797-2999 SN 0899-8213 J9 PHYS FLUIDS A-FLUID PD JUN PY 1991 VL 3 IS 6 BP 1572 EP 1576 DI 10.1063/1.857936 PG 5 WC Mechanics; Physics, Fluids & Plasmas SC Mechanics; Physics GA FN767 UT WOS:A1991FN76700011 ER PT J AU REISH, DJ OSHIDA, PS MEARNS, AJ GINN, TC AF REISH, DJ OSHIDA, PS MEARNS, AJ GINN, TC TI EFFECTS ON SALTWATER ORGANISMS SO RESEARCH JOURNAL OF THE WATER POLLUTION CONTROL FEDERATION LA English DT Review ID POLYCYCLIC AROMATIC-HYDROCARBONS; WIDESPREAD NEOGASTROPOD IMPOSEX; CENTRAL MEDITERRANEAN COASTS; CHRONIC PESTICIDE EXPOSURE; MYSID MYSIDOPSIS-BAHIA; SAN-FRANCISCO BAY; TRACE-METALS; HEAVY-METALS; OIL-SPILL; ORGANOCHLORINE COMPOUNDS C1 US EPA,SAN FRANCISCO,CA. PTI,BELLEVUE,WA. NOAA,SEATTLE,WA 98115. RP REISH, DJ (reprint author), CALIF STATE UNIV LONG BEACH,DEPT BIOL,LONG BEACH,CA 90840, USA. NR 157 TC 0 Z9 0 U1 1 U2 19 PU WATER ENVIRONMENT FEDERATION PI ALEXANDRIA PA 601 WYTHE ST, ALEXANDRIA, VA 22314-1994 SN 1047-7624 J9 RES J WATER POLLUT C PD JUN PY 1991 VL 63 IS 4 BP 696 EP 709 PG 14 WC Environmental Sciences; Limnology; Water Resources SC Environmental Sciences & Ecology; Marine & Freshwater Biology; Water Resources GA FR368 UT WOS:A1991FR36800045 ER PT J AU ADAIR, D MADIGOSKY, WM MEASE, NE AF ADAIR, D MADIGOSKY, WM MEASE, NE TI AN ELECTROOPTICAL SENSOR FOR SURFACE DISPLACEMENT MEASUREMENTS OF COMPLIANT COATINGS SO REVIEW OF SCIENTIFIC INSTRUMENTS LA English DT Note AB Compliant coatings are now being used in many engineering applications, chiefly in relation to sound absorption and noise shielding. Another, though still controversial, application is their use in the reduction of skin friction drag of moving vessels. The design of a compliant coating to realize the latter goal or to achieve optimum sound absorption is complex and requires the determination of the surface motion characteristics resulting from the hydrodynamic forces [D. M. Bushnell, J. N. Hefner, and R. L. Ash, Phys. Fluids 20, 531 (1977)]. C1 USN,CTR SURFACE WARFARE,SILVER SPRING,MD 20903. NATL INST STAND & TECHNOL,GAITHERSBURG,MD 20899. RP ADAIR, D (reprint author), BMT FLUID MECH LTD,TEDDINGTON TW11 8LZ,MIDDX,ENGLAND. NR 3 TC 1 Z9 1 U1 0 U2 0 PU AMER INST PHYSICS PI WOODBURY PA CIRCULATION FULFILLMENT DIV, 500 SUNNYSIDE BLVD, WOODBURY, NY 11797-2999 SN 0034-6748 J9 REV SCI INSTRUM JI Rev. Sci. Instrum. PD JUN PY 1991 VL 62 IS 6 BP 1652 EP 1653 DI 10.1063/1.1142450 PG 2 WC Instruments & Instrumentation; Physics, Applied SC Instruments & Instrumentation; Physics GA FP312 UT WOS:A1991FP31200049 ER PT J AU POWELL, CJ AF POWELL, CJ TI FORMAL DATABASES FOR SURFACE-ANALYSIS - THE CURRENT SITUATION AND FUTURE-TRENDS SO SURFACE AND INTERFACE ANALYSIS LA English DT Article; Proceedings Paper CT CONF ON QUANTITATIVE SURFACE ANALYSIS ( QSA-6 ) CY NOV 13-16, 1990 CL LONDON, ENGLAND ID AES; XPS AB Evaluated data are needed for surface analysis, just as for other measurements, so that analyses can be made reliably and effectively. Until recently, the principal sources of data were handbooks of spectra (mainly of elements) and review articles with values or equations for the parameters needed. This article describes three efforts to develop formal databases that can be incorporated into computer systems. Information is first given on a recently announced x-ray photoelectron spectroscopy database, which contains over 13 000 line positions, chemical shifts and splittings, together with associated software for searching by element, line type, line energy and other variables. Second, a summary is presented of a recent compilatation of evaluated elemental ion sputtering yields for applications in sputter depth profiling and secondary ion mass spectrometry. Finally, a description is given of a new database that is to contain Auger electron spectra and x-ray photoelectron spectra; the database architecture is being designed also to accommodate depth profiles and the results of measurements by other surface analysis techniques. RP POWELL, CJ (reprint author), NBS,DIV SURFACE SCI,GAITHERSBURG,MD 20899, USA. NR 26 TC 11 Z9 11 U1 4 U2 15 PU JOHN WILEY & SONS LTD PI W SUSSEX PA BAFFINS LANE CHICHESTER, W SUSSEX, ENGLAND PO19 1UD SN 0142-2421 J9 SURF INTERFACE ANAL JI Surf. Interface Anal. PD JUN PY 1991 VL 17 IS 6 BP 308 EP 314 DI 10.1002/sia.740170603 PG 7 WC Chemistry, Physical SC Chemistry GA FT811 UT WOS:A1991FT81100002 ER PT J AU MELMED, AJ CAMUS, PP AF MELMED, AJ CAMUS, PP TI COMPOSITE THIN-FILM CHARACTERIZATION BY ATOM PROBE FIELD-ION MICROSCOPY SO ULTRAMICROSCOPY LA English DT Article ID LAYERS AB A wide range of composite thin films now can be studied routinely by atom probe field ion microscopy (APFIM). Two examples, analyses of Cr-Ni multilayer and co-deposited Fe3O4-Ag thin films, are discussed and illustrate some aspects of the complementarity of APFIM to other analytic techniques. C1 CUSTOM PROBES UNLTD,GAITHERSBURG,MD 20878. NATL INST STAND & TECHNOL,DIV SURFACE SCI,GAITHERSBURG,MD 20899. NR 7 TC 2 Z9 2 U1 0 U2 1 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0304-3991 J9 ULTRAMICROSCOPY JI Ultramicroscopy PD JUN PY 1991 VL 35 IS 3-4 BP 277 EP 287 DI 10.1016/0304-3991(91)90080-P PG 11 WC Microscopy SC Microscopy GA FZ009 UT WOS:A1991FZ00900012 ER PT J AU RABIN, RM MCMURDIE, LA HAYDEN, CM WADE, GS AF RABIN, RM MCMURDIE, LA HAYDEN, CM WADE, GS TI MONITORING PRECIPITABLE WATER AND SURFACE WIND OVER THE GULF OF MEXICO FROM MICROWAVE AND VAS SATELLITE IMAGERY SO WEATHER AND FORECASTING LA English DT Article AB Spatial and temporal changes of atmospheric water vapor and surface wind speeds are investigated for a period following an intrusion of cold continental air over the Gulf of Mexico, during the Gulf of Mexico Experiment (GUFMEX) in March 1988. Microwave and infrared satellite measurements from the Special Sensor Microwave/Imager (SSM/I) instrument aboard the Defense Meteorological Satellite Project (DMSP) F8 satellite and from the GOES VISSR Atmospheric Sounder (VAS) are used to augment the sparse coverage of rawinsonde sites and surface reports in the vicinity of the Gulf of Mexico. Total precipitable water is derived from both instruments and from rawinsonde measurements at coastal locations and auxiliary sites on ships and platforms over the Gulf. Accuracies of the precipitable water derived from SSM/I and GOES are comparable, though microwave data provide more uniform coverage, when they are available, than VAS since they are relatively free from contamination by most clouds. Also, the moisture fields derived from microwave data appear to be less noisy than those derived from the infrared. To illustrate possible use of satellite data in the forecast office, moisture fields from both SSM/I and VAS are blended together into imagery, which are compared to analyses from an operational model. Surface wind speeds are also obtained from the microwave data and are compared to the surface observations. Analyses from satellite data appear to add considerable information to the moisture and wind analysis over the Gulf of Mexico and should help in forecasting moisture changes, particularly moisture return near the surrounding coastal areas. RP RABIN, RM (reprint author), NOAA,NATL ENVIRONM SATELLITE DATA & INFORMAT SERV,CTR SPACE & ENGN,1225 W DAYTON ST,MADISON,WI 53706, USA. RI Wade, Gary S./F-5630-2010 NR 0 TC 13 Z9 13 U1 0 U2 1 PU AMER METEOROLOGICAL SOC PI BOSTON PA 45 BEACON ST, BOSTON, MA 02108-3693 SN 0882-8156 J9 WEATHER FORECAST JI Weather Forecast. PD JUN PY 1991 VL 6 IS 2 BP 227 EP 243 DI 10.1175/1520-0434(1991)006<0227:MPWASW>2.0.CO;2 PG 17 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA FQ949 UT WOS:A1991FQ94900004 ER PT J AU HAGEMEYER, BC AF HAGEMEYER, BC TI A LOWER-TROPOSPHERIC THERMODYNAMIC CLIMATOLOGY FOR MARCH THROUGH SEPTEMBER - SOME IMPLICATIONS FOR THUNDERSTORM FORECASTING SO WEATHER AND FORECASTING LA English DT Article AB A thermodynamic climatology was constructed to investigate source regions of low-level moist airmasses and lower mid-tropospheric dry airmasses that contribute to the production of convective instability, and thunder-storms, over the United States. Mean monthly 1200 UTC values of potential temperature, mixing ratio, and geopotential height were computed at the surface and 750 mb for March through September (1966-1980) for 69 upper-air stations in the continental United States and Mexico. Analyses indicated that the Gulf of Mexico is the most significant source of low-level moisture east of the Continental Divide for all months, but the Atlantic Ocean also becomes a significant source in summer. The Gulf of California was found to be the most important source of low-level moisture west of the Continental Divide in summer. A distinct synoptic scale dryline was found over west Texas from March to June and analyses suggested that the strongest drylines occur in April and May. Northwest Mexico and the desert southwest were confirmed to be the source regions of the dryline. At 750 mb, source regions of dry airmasses were found to be the Baja California region and desert southwest in spring, the tradewind easterly dry layer in summer, and the dry, cool airmasses over the northern Pacific and northern Great Lakes regions in spring and summer. The moist, summer, tropical Pacific airstream was found not only to be deeper than that from the Gulf of Mexico, but also to be the primary source of moisture west of the Continental Divide. In summer, significant mean horizontal advection of warm, moist air from higher terrain into the Missouri Valley was noted. RP HAGEMEYER, BC (reprint author), NATL WEATHER SERV OFF,421 CROTON RD,MELBOURNE,FL 32935, USA. NR 0 TC 20 Z9 22 U1 0 U2 3 PU AMER METEOROLOGICAL SOC PI BOSTON PA 45 BEACON ST, BOSTON, MA 02108-3693 SN 0882-8156 J9 WEATHER FORECAST JI Weather Forecast. PD JUN PY 1991 VL 6 IS 2 BP 254 EP 270 DI 10.1175/1520-0434(1991)006<0254:ALTTCF>2.0.CO;2 PG 17 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA FQ949 UT WOS:A1991FQ94900006 ER PT J AU DOSWELL, CA AF DOSWELL, CA TI A POINT OF CLARIFICATION ABOUT AREA AND ENERGY ON COMMON THERMODYNAMIC DIAGRAMS SO WEATHER AND FORECASTING LA English DT Note RP DOSWELL, CA (reprint author), NOAA,ENVIRONM RES LABS,NATL SEVERE STORMS LAB,NORMAN,OK 73069, USA. RI Doswell III, Charles/E-7662-2010 NR 0 TC 1 Z9 1 U1 0 U2 0 PU AMER METEOROLOGICAL SOC PI BOSTON PA 45 BEACON ST, BOSTON, MA 02108-3693 SN 0882-8156 J9 WEATHER FORECAST JI Weather Forecast. PD JUN PY 1991 VL 6 IS 2 BP 299 EP 301 DI 10.1175/1520-0434(1991)006<0299:APOCAA>2.0.CO;2 PG 3 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA FQ949 UT WOS:A1991FQ94900009 ER PT J AU MURPHY, AH AF MURPHY, AH TI PROBABILITIES, ODDS, AND FORECASTS OF RARE EVENTS SO WEATHER AND FORECASTING LA English DT Editorial Material AB Several issues related to the mode of expression of forecasts of rare and severe events (RSEs) are addressed in this paper. These issues include the correspondence between forecasters' judgments and their forecasts, the problem of overforecasting, and the use of forecasts as a basis for rational decision making. Neither forecasters nor users are well served by current practices, according to which operational forecasts of RSEs are generally expressed in a categorical format. It is argued here that sound scientific and economic reasons exist for expressing forecasts of RSEs in terms of probabilities. Although quantification of uncertainty in forecasts of RSEs-and the communication of such information to users-presents some special problems, evidence accumulated from a multitude of operational and experimental probabilistic weather forecasting programs suggests that these problems involve no insurmountable difficulties. Moreover, when a probabilistic format is employed, forecasts of RSEs can correspond to forecasters' true judgments, the forecasting and decision-making tasks can be disentangled, the rationale for overforecasting RSEs is eliminated, and the needs of all users can be met in an optimal manner. Since the probabilities of RSEs seldom achieve high values, it might be desirable to provide users with information concerning the likelihood of such events relative to their climatological likelihood. Alternatively, the relative odds-that is, the ratio of an event's forecast odds to its climatological odds-could be reported. This supplemental information should help to focus users' attention on those occasions on which the probability of RSEs is relatively high. RP MURPHY, AH (reprint author), NOAA,NATL WEATHER SERV,NATL METEOROL CTR,CTR CLIMATE ANAL,WWB,ROOM 606,WASHINGTON,DC 20233, USA. NR 0 TC 36 Z9 36 U1 0 U2 3 PU AMER METEOROLOGICAL SOC PI BOSTON PA 45 BEACON ST, BOSTON, MA 02108-3693 SN 0882-8156 J9 WEATHER FORECAST JI Weather Forecast. PD JUN PY 1991 VL 6 IS 2 BP 302 EP 307 DI 10.1175/1520-0434(1991)006<0302:POAFOR>2.0.CO;2 PG 6 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA FQ949 UT WOS:A1991FQ94900010 ER PT J AU PELLA, PA FENG, L SMALL, JA AF PELLA, PA FENG, L SMALL, JA TI ADDITION OF M-SERIES AND L-SERIES LINES TO NIST ALGORITHM FOR CALCULATION OF X-RAY TUBE OUTPUT SPECTRAL DISTRIBUTIONS SO X-RAY SPECTROMETRY LA English DT Article AB Addition of M- and some minor L-series characteristic lines to an analytical algorithm for calculation of x-ray tube output spectral distributions is described. Such lines may be important for the analysis of elements of low atomic number (Z) where thin-window, high-Z target tubes are used for excitation. RP PELLA, PA (reprint author), NBS,DIV GAS & PARTICULATE SCI,GAITHERSBURG,MD 20899, USA. NR 5 TC 30 Z9 32 U1 0 U2 4 PU JOHN WILEY & SONS LTD PI W SUSSEX PA BAFFINS LANE CHICHESTER, W SUSSEX, ENGLAND PO19 1UD SN 0049-8246 J9 X-RAY SPECTROM JI X-Ray Spectrom. PD JUN PY 1991 VL 20 IS 3 BP 109 EP 110 DI 10.1002/xrs.1300200303 PG 2 WC Spectroscopy SC Spectroscopy GA FT551 UT WOS:A1991FT55100001 ER PT J AU RICKER, RE AF RICKER, RE TI COST OF CORROSION SO SCIENCE LA English DT Letter RP RICKER, RE (reprint author), NATL INST STAND & TECHNOL,CORROS GRP,GAITHERSBURG,MD 20899, USA. RI Ricker, Richard/H-4880-2011 OI Ricker, Richard/0000-0002-2871-4908 NR 3 TC 3 Z9 3 U1 0 U2 2 PU AMER ASSOC ADVANCEMENT SCIENCE PI WASHINGTON PA 1200 NEW YORK AVE, NW, WASHINGTON, DC 20005 SN 0036-8075 J9 SCIENCE JI Science PD MAY 31 PY 1991 VL 252 IS 5010 BP 1232 EP 1232 PG 1 WC Multidisciplinary Sciences SC Science & Technology - Other Topics GA FN857 UT WOS:A1991FN85700005 ER PT J AU BRUNE, WH ANDERSON, JG TOOHEY, DW FAHEY, DW KAWA, SR JONES, RL MCKENNA, DS POOLE, LR AF BRUNE, WH ANDERSON, JG TOOHEY, DW FAHEY, DW KAWA, SR JONES, RL MCKENNA, DS POOLE, LR TI THE POTENTIAL FOR OZONE DEPLETION IN THE ARCTIC POLAR STRATOSPHERE SO SCIENCE LA English DT Article ID TOTAL REACTIVE NITROGEN; ANTARCTIC STRATOSPHERE; INSITU MEASUREMENTS; AIRBORNE LIDAR; JANUARY 1989; WINTER; DENITRIFICATION; CLOUDS; VORTEX; EXPEDITION AB The nature of the Arctic polar stratosphere is observed to be similar in many respects to that of the Antarctic polar stratosphere, where an ozone hole has been identified. Most of the available chlorine (HCl and ClONO2) was converted by reactions on polar stratospheric clouds to reactive ClO and Cl2O2 throughout the Arctic polar vortex before midwinter. Reactive nitrogen was converted to HNO3, and some, with spatial inhomogeneity, fell out of the stratosphere. These chemical changes ensured characteristic ozone losses of 10 to 15% at altitudes inside the polar vortex where polar stratospheric clouds had occurred. These local losses can translate into 5 to 8% losses in the vertical column abundance of ozone. As the amount of stratospheric chlorine inevitably increases by 50% over the next two decades, ozone losses recognizable as an ozone hole may well appear. C1 HARVARD UNIV,DEPT CHEM,CAMBRIDGE,MA 02138. HARVARD UNIV,DEPT EARTH & PLANETARY SCI,CAMBRIDGE,MA 02138. UK METEOROL OFF,ATMOSPHER CHEM GRP,BRACKNELL RG12 ZSZ,BERKS,ENGLAND. NOAA,AERON LAB,BOULDER,CO 80303. UNIV CAMBRIDGE,DEPT CHEM,CAMBRIDGE CB2 1EW,ENGLAND. NASA,LANGLEY RES CTR,HAMPTON,VA 23665. RP BRUNE, WH (reprint author), PENN STATE UNIV,DEPT METEOROL,UNIVERSITY PK,PA 16802, USA. RI Toohey, Darin/A-4267-2008; Kawa, Stephan/E-9040-2012; McKenna, Daniel/E-7806-2014; Fahey, David/G-4499-2013 OI Toohey, Darin/0000-0003-2853-1068; McKenna, Daniel/0000-0002-4360-4782; Fahey, David/0000-0003-1720-0634 NR 52 TC 99 Z9 100 U1 1 U2 5 PU AMER ASSOC ADVANCEMENT SCIENCE PI WASHINGTON PA 1200 NEW YORK AVE, NW, WASHINGTON, DC 20005 SN 0036-8075 J9 SCIENCE JI Science PD MAY 31 PY 1991 VL 252 IS 5010 BP 1260 EP 1266 DI 10.1126/science.252.5010.1260 PG 7 WC Multidisciplinary Sciences SC Science & Technology - Other Topics GA FN857 UT WOS:A1991FN85700028 PM 17842951 ER PT J AU DEARDEN, DV JOHNSON, RD HUDGENS, JW AF DEARDEN, DV JOHNSON, RD HUDGENS, JW TI NEW RYDBERG STATES OF ALUMINUM MONOFLUORIDE OBSERVED BY RESONANCE-ENHANCED MULTIPHOTON IONIZATION SPECTROSCOPY SO JOURNAL OF PHYSICAL CHEMISTRY LA English DT Article ID AIF; SPECTRA; RADICALS AB AlF was generated in the gas phase with high-temperature reduction of AlF3 by Al. AlF was detected and characterized with 1+2, 2+1, 2+2, 3+1, and 3+2 resonance-enhanced multiphoton ionization spectroscopy. Thirteen new Rydberg states that lie between 70 000 and 77 000 cm-1 were identified for the first time. These new states in combination with previously known states were organized into six Rydberg series. Least-squares fitting of the Rydberg series to the Rydberg equation yields the adiabatic ionization potential of AlF, IP(a) = 9.729 +/- 0.001 eV. Vibrational intervals of the new Rydberg states are about 25% greater than those of AlF(X1-SIGMA+), with most lying between 930 and 980 cm-1. C1 NATL INST STAND & TECHNOL,DIV CHEM KINET,GAITHERSBURG,MD 20899. NR 27 TC 11 Z9 11 U1 0 U2 2 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 SN 0022-3654 J9 J PHYS CHEM-US JI J. Phys. Chem. PD MAY 30 PY 1991 VL 95 IS 11 BP 4291 EP 4296 DI 10.1021/j100164a022 PG 6 WC Chemistry, Physical SC Chemistry GA FP241 UT WOS:A1991FP24100022 ER PT J AU TURNIPSEED, AA BIRKS, JW CALVERT, JG AF TURNIPSEED, AA BIRKS, JW CALVERT, JG TI KINETICS AND TEMPERATURE-DEPENDENCE OF THE BRO + CLO REACTION SO JOURNAL OF PHYSICAL CHEMISTRY LA English DT Article ID ANTARCTIC OZONE; ATMOSPHERIC CHEMISTRY; PHOTOCHEMICAL DATA; RATE-CONSTANT; BROMINE; PRODUCT; STRATOSPHERE; CHLORINE; RADICALS; CIO AB The kinetics of the BrO + ClO reaction was studied over the temperature range 234-406 K by discharge flow/mass spectrometry. The total rate constant for the reaction was found to have a significant negative activation energy and is given by k(l) (T) = (2.59 +/- 0.36) x 10(-12) exp[(445 +/- 84)/T] cm3 molecule-1 s-1. The reaction has three product channels: (a) ClOO + Br, (b) OClO + Br, and (c) BrCl + O2. The branching ratios for the three channels as a function of temperature were measured, and it was found that the channel leading to formation of OClO becomes dominant at lower temperatures (branching ratio of 0.51 at 250 K). Evidence for the direct formation of BrCl was found, yielding a branching ratio of 0.09-0.10 for the BrCl channel over the temperature range 250-406 K. The temperature-dependent rate coefficients for the three channels are given by k1a = (2.1 +/- 0.4) x 10(-12) exp[(258 +/- 56)/T], k1b = (6.7 +/- 1.0) x 10(-13) exp[(622 +/- 94)/T], and k1c = (1.9 +/- 0.6) x 10(-13) exp[(513 +/- 86)/T] cm3 molecule-1 s-1. These results are discussed relative to other recent studies and their importance in understanding the stratospheric chemistry of the Antarctic ozone hole. C1 UNIV COLORADO,DEPT CHEM & BIOCHEM,BOULDER,CO 80309. UNIV COLORADO,NOAA,COOPERAT INST RES ENVIRONM SCI,BOULDER,CO 80309. NATL CTR ATMOSPHER RES,DIV ATMOSPHER CHEM,BOULDER,CO 80307. RI Birks, John/H-7451-2013 OI Birks, John/0000-0003-1691-1354 NR 27 TC 38 Z9 38 U1 0 U2 8 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 SN 0022-3654 J9 J PHYS CHEM-US JI J. Phys. Chem. PD MAY 30 PY 1991 VL 95 IS 11 BP 4356 EP 4364 DI 10.1021/j100164a035 PG 9 WC Chemistry, Physical SC Chemistry GA FP241 UT WOS:A1991FP24100035 ER PT J AU HUDGENS, JW JOHNSON, RD TIMONEN, RS SEETULA, JA GUTMAN, D AF HUDGENS, JW JOHNSON, RD TIMONEN, RS SEETULA, JA GUTMAN, D TI KINETICS OF THE REACTION OF CCL3 + BR-2 AND THERMOCHEMISTRY OF CCL3 RADICAL AND CATION SO JOURNAL OF PHYSICAL CHEMISTRY LA English DT Article ID BOND-DISSOCIATION ENERGIES; FREE-RADICALS; IONIZATION-POTENTIALS; MOLECULAR CHLORINE; THERMOCHEMISTRY; METHYL; HEATS; CH3; STABILITY; I-C3H7 AB The rate constant of the CCl3 + Br2 --> CCl3Br + Br reaction was determined as a function of temperature between 300 and 532 K and fit to an Arrhenius expression: k1 (L mol-1 s-1) = (1.8 +/- 0.4) x 10(8) exp[(-1.43 +/- 0.29) kcal mol-1/RT]. The reaction was studied in a tubular flow reactor by using laser photolysis to produce the CCl3 reactant and photoionization mass spectrometry to monitor CCl3 in time-resolved experiments. Previously published kinetic data were reevaluated to obtain k-1, the rate constant for the reverse reaction, and recent spectroscopic data were used to calculate accurate entropies and heat capacities. The values of k-1, k1, and these calculated thermodynamic properties were used in a third law determination to obtain DELTA-H-degrees-f,298.15(CCl3) = 17.0 +/- 0.6 kcal mol-1 and DELTA-H-degrees-f,0(CCl3) = 16.7 +/- 0.6 kcal mol-1. This information was combined with spectroscopic data on CCl3+ to obtain DELTA-H-degrees-f,298.15(CCl3+) = 205.2 +/- 0.6 kcal mol-1 and DELTA-H-degrees-f,0(CCl3+) = 203.7 +/- 0.6 kcal mol-1. Bond energies of several relevant compounds and tables of thermodynamic functions for CCl3 and CCl3+ are presented. An improved heat of formation for the CCl3O2 radical DELTA-H-degrees-f,298.15(CCl3O2) = 2.7 +/- 1.1 kcal mol-1, is also reported. C1 CATHOLIC UNIV AMER,DEPT CHEM,WASHINGTON,DC 20064. RP HUDGENS, JW (reprint author), NATL INST STAND & TECHNOL,DIV CHEM KINET & THERMODYNAM,GAITHERSBURG,MD 20899, USA. NR 43 TC 73 Z9 73 U1 1 U2 5 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 SN 0022-3654 J9 J PHYS CHEM-US JI J. Phys. Chem. PD MAY 30 PY 1991 VL 95 IS 11 BP 4400 EP 4405 DI 10.1021/j100164a043 PG 6 WC Chemistry, Physical SC Chemistry GA FP241 UT WOS:A1991FP24100043 ER PT J AU SHOUTE, LCT NETA, P AF SHOUTE, LCT NETA, P TI IODINE ATOMS AND IODOMETHANE RADICAL CATIONS - THEIR FORMATION IN THE PULSE-RADIOLYSIS OF IODOMETHANE IN ORGANIC-SOLVENTS, THEIR COMPLEXES, AND THEIR REACTIVITY WITH ORGANIC REDUCTANTS SO JOURNAL OF PHYSICAL CHEMISTRY LA English DT Article ID OXIDIZED SULFUR CENTERS; PEROXYL RADICALS; AQUEOUS-SOLUTION; RATE CONSTANTS; OXIDATION; IONS; STABILIZATION; SULFIDES; BONDS AB Pulse radiolysis of iodomethane in various organic solvents leads to formation of iodine atoms or iodomethane radical cations, which in turn form complexes with iodomethane or with the solvent. Radiolysis in cyclohexane gives CH3I.I, which exhibits an absorption peak at 390 nm, whereas radiolysis in benzene forms the solvent complex, C6H6.I, which exhibits an intense broad absorption centered at 490 nm. Radiolysis of iodomethane in acetone, benzonitrile, and halogenated hydrocarbons results in formation of the radical cation CH3I+. In the former two solvents, this species forms a complex with another molecule of iodomethane to give (CH3I)2+, which absorbs at 420 nm, in agreement with previous results in aqueous solutions, but in halogenated hydrocarbons it forms complexes with the solvents, absorbing at 320-360 nm, i.e., near the absorption of monomeric CH3I.+ in water. Complexes of I atoms oxidize phenol and triphenylamine relatively slowly whereas complexes of CH3I.+ react more rapidly. The reactivity of the CH3I.+.RX complexes increases in the order of RX = CH2Cl2, CHCl3, CH2Br2, CCl4, CH3I, and for each complex the reactivity with phenol increases with increase in electron donating power of substituents. Replacing the methyl group of iodomethane radical cation with ethyl or isopropyl decreases the reactivity, whereas trifluoromethyl increases the reactivity. These oxidation reactions proceed via an intermediate complex between the iodine species and the organic reductant. C1 NATL INST STAND & TECHNOL,DIV CHEM KINET,GAITHERSBURG,MD 20899. NR 38 TC 15 Z9 15 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 MAY 30 PY 1991 VL 95 IS 11 BP 4411 EP 4414 DI 10.1021/j100164a045 PG 4 WC Chemistry, Physical SC Chemistry GA FP241 UT WOS:A1991FP24100045 ER PT J AU NAHOR, GS NETA, P HAMBRIGHT, P ROBINSON, LR AF NAHOR, GS NETA, P HAMBRIGHT, P ROBINSON, LR TI ONE-ELECTRON OXIDATION OF NICKEL PORPHYRINS - EFFECT OF STRUCTURE AND MEDIUM ON FORMATION OF NICKEL(III) PORPHYRIN OR NICKEL(II) PORPHYRIN PI-RADICAL CATION SO JOURNAL OF PHYSICAL CHEMISTRY LA English DT Article ID BROMINE ATOM COMPLEXES; PULSE-RADIOLYSIS; AQUEOUS-SOLUTIONS; PEROXYL RADICALS; RATE CONSTANTS; METALLOPORPHYRINS; REACTIVITY; RESONANCE; REDUCTION AB The oxidation of several nickel(II) porphyrins by various radicals has been studied by pulse radiolysis in different media (Cl2.- and Br2.- in aqueous systems, Br atoms in organic solvents, and peroxyl radicals in organic and aqueous/organic systems). Photochemical oxidation was also examined in some cases. The absorption spectrum of the oxidation product was monitored within several microseconds after the pulse. Two types of differential spectra were observed, a broad absorption at 640-700 nm ascribed to the pi-radical cation, or a sharp absorption at 560-580 nm ascribed to nickel(III) porphyrin. Ni(II)TPP (tetraphenylporphyrin) in several organic solvents, protic and aprotic, was oxidized to Ni(III)TPP. The addition of 10% water as cosolvent or 0.1 M of electrolyte changed the route of oxidation to give the radical cation Ni(II)TPP.+. On the other hand, Ni(II)TSPP (tetrakis(4-sulfonatophenyl)porphyrin), which has four negative charges, was oxidized on the porphyrin ligand by all the radicals examined, in water and in several organic solvents. Ni(II) bis(N-methyl-4-pyridyl)diphenylporphyrin, with a charge of +2, and Ni(II) tris(4-sulfonatophenyl)(N-methyl-4-pyridyl)porphyrin, with an overall charge of -2, were oxidized on the ligand in aqueous solution but on the metal in organic solvents. These and other results led to the conclusion that most radicals react with Ni(II)P by an inner-sphere mechanism to bind onto the metal and give the Ni(III)P form. However, when the porphyrin is sufficiently charged to repel the axially bound anion, and/or when the medium enhances the separation of this anion from the metal, the result is oxidation of the porphyrin pi-system. In all cases, however, the one-electron-oxidation products, whether Ni(II)P.+ or Ni(III)P, decay to yield two-electron ring oxidation products. C1 NATL INST STAND & TECHNOL,DIV CHEM KINET,GAITHERSBURG,MD 20899. HOWARD UNIV,DEPT CHEM,WASHINGTON,DC 20059. NR 20 TC 26 Z9 26 U1 0 U2 5 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 SN 0022-3654 J9 J PHYS CHEM-US JI J. Phys. Chem. PD MAY 30 PY 1991 VL 95 IS 11 BP 4415 EP 4418 DI 10.1021/j100164a046 PG 4 WC Chemistry, Physical SC Chemistry GA FP241 UT WOS:A1991FP24100046 ER PT J AU NAHOR, GS NETA, P ALFASSI, ZB AF NAHOR, GS NETA, P ALFASSI, ZB TI PERFLUOROBUTYLPEROXYL RADICAL AS AN OXIDANT IN VARIOUS SOLVENTS SO JOURNAL OF PHYSICAL CHEMISTRY LA English DT Article ID ELEMENTARY BIMOLECULAR REACTIONS; SOLVATION ENERGY RELATIONSHIPS; ONE-ELECTRON OXIDATION; RATE CONSTANTS; METHYLPEROXYL RADICALS; AQUEOUS-SOLUTIONS; PEROXYL RADICALS; LIQUID SOLUTIONS; PARAMETERS; BETA AB Perfluorobutylperoxyl radicals were produced by pulse radiolysis of aerated solutions of perfluorobutyl iodide. The rate constants for reaction of this radical with several organic reductants, chlorpromazine, trolox, hydroquinone, and several other phenols, were determined in various solvents and were found to be in the range of 10(5)-10(9) M-1 s-1. By comparison with other haloalkylperoxyl radicals, C4F9OO. was found to be a much more powerful oxidant, whose reactions took place more rapidly and were less sensitive to solvent and substituent effects. The rate constants (k) for oxidation of a series of para-substituted phenols by C4F9OO. gave a good linear correlation between log k and the electrophilic substituent constant sigma+, with a slope of rho+ = -2.3, indicating formation of a positively charged transition state. Parallel experiments with CCl3OO. were limited to the most reactive phenols and gave a higher slope, rho+ = -3.3. The rates of reaction of C4F9OO. with trolox and chlorpromazine were found to depend on solvent viscosity, but much less on solvent polarity and acid-base properties, probably because they were closer to the diffusion-controlled limit. The longer chain C10F21OO. was somewhat less reactive than C4F9OO. because of geometric factors. C1 NATL INST STAND & TECHNOL,DIV CHEM KINET,GAITHERSBURG,MD 20899. NR 16 TC 6 Z9 6 U1 0 U2 0 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 SN 0022-3654 J9 J PHYS CHEM-US JI J. Phys. Chem. PD MAY 30 PY 1991 VL 95 IS 11 BP 4419 EP 4422 DI 10.1021/j100164a047 PG 4 WC Chemistry, Physical SC Chemistry GA FP241 UT WOS:A1991FP24100047 ER PT J AU DOUGLAS, JF HUBBARD, JB AF DOUGLAS, JF HUBBARD, JB TI SEMIEMPIRICAL THEORY OF RELAXATION - CONCENTRATED POLYMER-SOLUTION DYNAMICS SO MACROMOLECULES LA English DT Article ID UNIVERSAL DIELECTRIC RESPONSE; LINEAR AMORPHOUS POLYMERS; SPIN-GLASS RELAXATION; ZERO-SHEAR VISCOSITY; SLOW-MODE DIFFUSION; LIGHT-SCATTERING; MOLECULAR-WEIGHT; RANDOM-WALKS; QUANTITATIVE EXPLANATION; TEMPERATURE DEPENDENCES AB Classical models of viscoelasticity neglect memory effects arising from material inhomogeneity and cooperative molecular motion. These memory effects are modeled by using an integral equation approach in which physical arguments are employed to estimate the memory kernel. Our model memory kernel depends on two parameters: beta, which is interpreted as a measure of material inhomogeneity, and phi, which is interpreted as a measure of cooperativity of molecular motion. Here we apply our relaxation model to polymer melt dynamics. An idealized "cluster" model of stress relaxation in glasses is introduced to estimate beta. This model rationalizes well the observed stress relaxation of polymer glasses. A cluster model is also introduced to estimate the molecular weight dependence of the zero-shear rate viscosity and the diffusion coefficient of entangled polymers. For flexible polymers in three dimensions the viscosity molecular weight exponent ranges in the interval 3.3 to 3.7, depending on the strength of the excluded-volume interaction. The diffusion coefficient molecular weight exponent in three dimensions is predicted to lie in the interval -2.3 to -2.5. Results similar to the reptation model are obtained in four dimensions, and the Rouse theory is recovered in the limit of infinite dimensionality. Estimates of the concentration dependence of entangled polymer solution transport properties are also given. RP NATL INST STAND & TECHNOL, GAITHERSBURG, MD 20899 USA. NR 184 TC 132 Z9 132 U1 2 U2 20 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 0024-9297 EI 1520-5835 J9 MACROMOLECULES JI Macromolecules PD MAY 27 PY 1991 VL 24 IS 11 BP 3163 EP 3177 DI 10.1021/ma00011a020 PG 15 WC Polymer Science SC Polymer Science GA FN849 UT WOS:A1991FN84900020 ER PT J AU LAYER, HP GREENE, GL AF LAYER, HP GREENE, GL TI ELASTIC-DEFORMATION OF A MONOLITHIC PERFECT CRYSTAL INTERFEROMETER - IMPLICATIONS FOR GRAVITATIONAL PHASE-SHIFT EXPERIMENTS SO PHYSICS LETTERS A LA English DT Article ID NEUTRON INTERFEROMETRY; DYNAMICAL DIFFRACTION; QUANTUM INTERFERENCE; FIELD AB A calculation of the gravitationally induced distortion of a monolithic silicon interferometer using the finite element method has been used to analyze the data from a gravitational phase shift experiment using neutrons. The observed dependence of the X-ray phase shift on interferometer rotational angle has been reproduced. An additional interferometer distortion has been identified which can explain the discrepancy between the observed neutron phase shift and the theoretical value. RP LAYER, HP (reprint author), NATL INST STANDARDS & TECHNOL,GAITHERSBURG,MD 20899, 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 0375-9601 J9 PHYS LETT A JI Phys. Lett. A PD MAY 27 PY 1991 VL 155 IS 8-9 BP 450 EP 454 DI 10.1016/0375-9601(91)90645-O PG 5 WC Physics, Multidisciplinary SC Physics GA FQ323 UT WOS:A1991FQ32300003 ER PT J AU MARTIRE, DE RIESTER, RL BRUNO, TJ HUSSAM, A POE, DP AF MARTIRE, DE RIESTER, RL BRUNO, TJ HUSSAM, A POE, DP TI GENERALIZED TREATMENT OF SPATIAL AND TEMPORAL COLUMN PARAMETERS, APPLICABLE TO GAS, LIQUID AND SUPERCRITICAL FLUID CHROMATOGRAPHY .2. APPLICATION TO SUPERCRITICAL CO2 SO JOURNAL OF CHROMATOGRAPHY LA English DT Article AB Equations derived in Part I [D. E. Martire, J. Chromatogr., 461 (1989) 165] are used to calculate distribution functions, average densities and column profiles for supercritical fluid chromatography with carbon dioxide as the mobile phase. An approximation for the column-average capacity factor in terms of the local capacity factor is evaluated and conditions are given for its applicability. C1 NATL INST STAND & TECHNOL,DIV THERMOPHYS,BOULDER,CO 80303. RP MARTIRE, DE (reprint author), GEORGETOWN UNIV,DEPT CHEM,WASHINGTON,DC 20057, USA. NR 8 TC 23 Z9 23 U1 0 U2 0 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0021-9673 J9 J CHROMATOGR PD MAY 24 PY 1991 VL 545 IS 1 BP 135 EP 147 DI 10.1016/S0021-9673(01)88702-1 PG 13 WC Chemistry, Analytical SC Chemistry GA FQ109 UT WOS:A1991FQ10900011 ER PT J AU NACKERDIEN, Z RAO, G CACCIUTTOLO, MA GAJEWSKI, E DIZDAROGLU, M AF NACKERDIEN, Z RAO, G CACCIUTTOLO, MA GAJEWSKI, E DIZDAROGLU, M TI CHEMICAL NATURE OF DNA-PROTEIN CROSS-LINKS PRODUCED IN MAMMALIAN CHROMATIN BY HYDROGEN-PEROXIDE IN THE PRESENCE OF IRON OR COPPER IONS SO BIOCHEMISTRY LA English DT Article ID DEOXYRIBONUCLEIC-ACID; DAMAGE; CELLS; NUCLEOHISTONE; SUPEROXIDE; MECHANISM; BASES; RADIATION; TYROSINE; THYMINE AB We report on the elucidation of DNA-protein cross-links formed in isolated mammalian chromatin upon treatment with H2O2 in the presence of iron or copper ions. Analysis of chromatin samples by gas chromatography/mass spectrometry after hydrolysis and derivatization showed the presence of 3-[(1,3-dihydro-2,4-dioxopyrimidin-5-yl) methyl]-L-tyrosine (thymine-tyrosine cross-link) on the basis of the gas chromatographic and mass spectrometric characteristics of the trimethylsilylated authentic compound. Other DNA-protein cross-links involving thymine and the aliphatic amino acids and cytosine and tyrosine, which were known to occur in nucleohistone gamma-irradiated under anoxic conditions, were not observed. This was due to inhibition by oxygen as clearly shown by experiments that were carried out using ionizing radiation under both oxic and anoxic conditions instead of using H2O2 and metal ions. However, oxygen did not inhibit formation of the thymine-tyrosine cross-link in gamma-irradiated chromatin or in chromatin treated with H2O2 and metal ions. The yield of the thymine-tyrosine cross-link was higher upon treatment with H2O2/chelated Fe3+ ions than with H2O2/unchelated Fe3+ ions. By contrast, H2O2/unchelated Cu2+ ions produced a higher yield than H2O2/chelated Cu2+ ions. Almost complete inhibition of cross-link formation was provided by the hydroxyl radical scavengers mannitol and dimethyl sulfoxide when H2O2/chelated metal ions were used. On the other hand, scavengers only partially inhibited formation of cross-links when H2O2/unchelated metal ions were used, possibly indicating the site-specific nature of cross-linking. Superoxide dismutase afforded partial inhibition only when chelated ions were used. The mechanism underlying formation of this DNA-protein cross-link is thought to involve addition of the hydroxyl radical generated allyl radical of thymine to carbon-3 of tyrosine followed by subsequent oxidation of the adduct radical. C1 NATL INST STAND & TECHNOL,CHEM SCI & TECHNOL LAB,GAITHERSBURG,MD 20899. UNIV STELLENBOSCH,DEPT RADIOTHERAPY,TYGERBERG 7505,SOUTH AFRICA. UNIV MARYLAND,CATONSVILLE,MD 21228. MARYLAND BIOTECHNOL INST,CTR MED BIOTECHNOL,BALTIMORE,MD 21228. NR 51 TC 76 Z9 78 U1 1 U2 6 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 SN 0006-2960 J9 BIOCHEMISTRY-US JI Biochemistry PD MAY 21 PY 1991 VL 30 IS 20 BP 4873 EP 4879 DI 10.1021/bi00234a006 PG 7 WC Biochemistry & Molecular Biology SC Biochemistry & Molecular Biology GA FM712 UT WOS:A1991FM71200006 PM 2036356 ER PT J AU CHURNSIDE, JH AF CHURNSIDE, JH TI APERTURE AVERAGING OF OPTICAL SCINTILLATIONS IN THE TURBULENT ATMOSPHERE SO APPLIED OPTICS LA English DT Article ID INNER-SCALE; SPECTRUM; PROPAGATION AB We have developed approximate expressions for the aperture-averaging factor of optical scintillation in the turbulent atmosphere. For large apertures and weak path-integrated turbulence with a small inner scale, the variance of signal fluctuations is proportional to the -7/3 power of the ratio of the aperture diameter to the Fresnel zone size. If the inner scale is large, the variance is proportional to the -7/3 power of the ratio of the aperture diameter to the inner scale. In strong path-integrated turbulence, two scales develop. That portion of the variance associated with the smaller scale is proportional to the -2 power of the ratio of the aperture diameter to the phase coherence length. That portion of the variance associated with the larger scale is proportional to the -7/3 power of the ratio of the aperture diameter to the scattering disk. These simple approximations are within a factor of 2 of the measurements. RP CHURNSIDE, JH (reprint author), NOAA,WAVE PROPAGAT LAB,325 BROADWAY,BOULDER,CO 80303, USA. RI Churnside, James/H-4873-2013 NR 33 TC 95 Z9 100 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 MAY 20 PY 1991 VL 30 IS 15 BP 1982 EP 1994 PG 13 WC Optics SC Optics GA FN982 UT WOS:A1991FN98200016 PM 20700167 ER PT J AU CONTI, PS FITZPATRICK, EL AF CONTI, PS FITZPATRICK, EL TI DD-13 - A VERY YOUNG AND HEAVILY REDDENED EARLY O-STAR IN THE LARGE MAGELLANIC CLOUD SO ASTROPHYSICAL JOURNAL LA English DT Article DE CLUSTERS, OPEN; GALAXIES, MAGELLANIC CLOUDS; STARS, EARLY-TYPE; STARS, INDIVIDUAL (DD-13) ID H-II REGIONS; STELLAR AB In this paper we investigate the Large Magellanic Cloud star DD 13, which is likely the major ionizing source of the nebula N159A. We have obtained new optical spectroscopy and new estimates of the broadband photometric properties of DD 13. We find a spectral type of O3-O6 V, E(B - V) = 0.64, and M(V) = -6.93. The spectral type cannot be more precisely defined due to contamination of the spectral data by nebular emission, obliterating the important He I classification lines. These results, plus a published estimate of the Lyman continuum photon injection rate into N159A, suggest that DD 13 actually consists of approximately 2-4 young, early O stars still enshrouded by their natal dust cloud. The star DD 13 may be a younger example of the type of tight cluster represented by the LMC "star" Sk-66-degrees-41, recently revealed to be composed of six or more components. C1 UNIV COLORADO,NATL INST STANDARDS & TECHNOL,BOULDER,CO 80309. PRINCETON UNIV OBSERV,PRINCETON,NJ 08544. CERRO TOLOLO INTERAMER OBSERV,LA SERENA,CHILE. RP CONTI, PS (reprint author), UNIV COLORADO,JOINT INST LAB ASTROPHYS,BOULDER,CO 80309, USA. NR 22 TC 8 Z9 8 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 MAY 20 PY 1991 VL 373 IS 1 BP 100 EP 104 DI 10.1086/170028 PN 1 PG 5 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA FK917 UT WOS:A1991FK91700011 ER PT J AU RAMASWAMY, V SCHWARZKOPF, MD LIU, SC AF RAMASWAMY, V SCHWARZKOPF, MD LIU, SC TI SPECIAL SECTION - THE INTERCOMPARISON OF RADIATION CODES IN CLIMATE MODELS - PREFACE SO JOURNAL OF GEOPHYSICAL RESEARCH-ATMOSPHERES LA English DT Editorial Material C1 NOAA, ENVIRONM RES LAB, AERON LAB, 325 BROADWAY, BOULDER, CO 80303 USA. NR 2 TC 0 Z9 0 U1 0 U2 1 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 2169-897X J9 J GEOPHYS RES-ATMOS JI J. Geophys. Res.-Atmos. PD MAY 20 PY 1991 VL 96 IS D5 BP 8921 EP 8923 DI 10.1029/91JD00875 PG 3 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA FN179 UT WOS:A1991FN17900001 ER PT J AU FOUQUART, Y BONNEL, B RAMASWAMY, V AF FOUQUART, Y BONNEL, B RAMASWAMY, V TI INTERCOMPARING SHORTWAVE RADIATION CODES FOR CLIMATE STUDIES SO JOURNAL OF GEOPHYSICAL RESEARCH-ATMOSPHERES LA English DT Article ID SOLAR-RADIATION; WATER CLOUDS; PARAMETERIZATION; MODELS; ABSORPTION AB As a second step of the international program of Intercomparison of Radiation Codes Used in Climate Models (ICRCCM), an intercomparison of shortwave radiation models was initiated. Among the 26 codes that participated in the comparison were very detailed (line-by-line), narrow-band (high-spectral resolution), as well as highly parameterized (low-spectral resolution) models. A considerable spread was detected in the response of these models to a set of well-defined atmospheric profiles. Substantial discrepancies exist among models even for the simplest case of pure water vapor absorption with standard deviation ranging from 1% to 3% for the downward fluxes at the surface and from 6% to 11% for the total atmospheric absorption. The divergences in downward surface flux increase to nearly 4% when all absorbers and the molecular scattering are considered. In cloudy conditions the divergences range from 4% to 10%, depending on the cloud optical thickness. Another major uncertainity that has been identified is the spectral averaging of the scattering properties which can result in very significant errors for low spectral resolution codes. Since these errors appear to be systematic, they may induce unrealistic feedback mechanisms in numerical climate models. The amplitude of the differences between models is in many cases larger than the accuracy required for the achievements of several objectives of the World Climate Research Program. While reference solutions for the absorption and scattering in atmospheres can be obtained based on the state-of-the-art spectroscopic knowledge and rigorous computational techniques, the absolute tests of the validity of the radiation algorithms would be comprehensive field experiments in which the radiative and all relevant atmospheric parameters are measured to a high degree of accuracy. C1 PRINCETON UNIV, NOAA, GEOPHYS FLUID DYNAM LAB, PRINCETON, NJ 08542 USA. RP FOUQUART, Y (reprint author), LAB OPT ATMOSPHER, F-59655 VILLENEUVE DASCQ, FRANCE. NR 42 TC 141 Z9 148 U1 1 U2 5 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 MAY 20 PY 1991 VL 96 IS D5 BP 8955 EP 8968 DI 10.1029/90JD00290 PG 14 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA FN179 UT WOS:A1991FN17900004 ER PT J AU FEIGELSON, EM FOMIN, BA GORCHAKOVA, IA ROZANOV, EV TIMOFEYEV, YM TROTSENKO, AN SCHWARZKOPF, MD AF FEIGELSON, EM FOMIN, BA GORCHAKOVA, IA ROZANOV, EV TIMOFEYEV, YM TROTSENKO, AN SCHWARZKOPF, MD TI CALCULATION OF LONGWAVE RADIATION FLUXES IN ATMOSPHERES SO JOURNAL OF GEOPHYSICAL RESEARCH-ATMOSPHERES LA English DT Article ID BAND-MODEL ANALYSIS; INTEGRATED INTENSITY; ABSORPTION AB A technique for the computation of longwave radiative quantities using the line-by-line approach has been developed in the Soviet Union. The method has been applied to obtain fluxes and cooling rates for standard atmospheric profiles used in the Intercomparison of Radiation Codes Used in Climate Models (ICRCCM) sponsored by the World Meteorological Organization. The sensitivity of the result to changes in the vertical quadrature scheme, the angular integration, and the spectral line shape is evaluated. Fluxes and cooling rates in the troposphere are in general agreement with those obtained with different line-by-line models. Results from parameterized models, including a wideband statistical model and one employing the integral transmission function, have been compared to the line-by-line results. Flux errors in the simplified schemes are of the order of 10 W/m2. The sensitivity of these models to changes in atmospheric profiles, or to an increase in CO2 amount, is similar to that of the line-by-line calculations. C1 MAIN GEOPHYS OBSERV, LENINGRAD, USSR. IV KURCHATOV ATOM ENERGY INST, DEPT MOLEC PHYS, MOSCOW 123182, USSR. AA ZHDANOV STATE UNIV, INST PHYS, LENINGRAD B-164, USSR. NOAA, GEOPHYS FLUID DYNAM LAB, PRINCETON, NJ 08542 USA. RP FEIGELSON, EM (reprint author), ACAD SCI USSR, INST ATMOSPHER PHYS, PAZHEVSKY 3, MOSCOW V-71, USSR. RI Timofeev, Yuriy/K-1618-2013; Rozanov, Eugene/A-9857-2012 OI Timofeev, Yuriy/0000-0003-2771-9931; Rozanov, Eugene/0000-0003-0479-4488 NR 45 TC 16 Z9 19 U1 0 U2 2 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 MAY 20 PY 1991 VL 96 IS D5 BP 8985 EP 9001 DI 10.1029/91JD00449 PG 17 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA FN179 UT WOS:A1991FN17900006 ER PT J AU SCHWARZKOPF, MD FELS, SB AF SCHWARZKOPF, MD FELS, SB TI THE SIMPLIFIED EXCHANGE METHOD REVISITED - AN ACCURATE, RAPID METHOD FOR COMPUTATION OF INFRARED COOLING RATES AND FLUXES SO JOURNAL OF GEOPHYSICAL RESEARCH-ATMOSPHERES LA English DT Article ID LINE PARAMETERS COMPILATION; WATER-VAPOR; ABSORPTION; ATMOSPHERE; EDITION AB The performance and construction of a new algorithm for the calculation of infrared cooling rates and fluxes in terrestrial general circulation models are described in detail. The computational method, which is suitable for use in models of both the troposphere and the middle atmosphere, incorporates effects now known to be important, such as an extended water vapor e-type continuum, careful treatment of water vapor lines, of water-carbon dioxide overlap, and of Voigt line shape. The competing requirements of accuracy and speed are both satisfied by extensive use of a generalization of the simplified exchange approximation of Fels and Schwarzkopf (1975). Cooling rates and fluxes are validated by comparison with benchmark line-by-line calculations on standard atmospheric profiles obtained for the Intercomparison of Radiation Codes Used in Climate Models (ICRCCM). Results indicate that the new algorithm is substantially more accurate than any previously used at the Geophysical Fluid Dynamics Laboratory. RP SCHWARZKOPF, MD (reprint author), PRINCETON UNIV, NOAA, GEOPHYS FLUID DYNAM LAB, POB 308, PRINCETON, NJ 08542 USA. NR 33 TC 174 Z9 177 U1 2 U2 6 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 MAY 20 PY 1991 VL 96 IS D5 BP 9075 EP 9096 DI 10.1029/89JD01598 PG 22 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA FN179 UT WOS:A1991FN17900012 ER PT J AU FELS, SB KIEHL, JT LACIS, AA SCHWARZKOPF, MD AF FELS, SB KIEHL, JT LACIS, AA SCHWARZKOPF, MD TI INFRARED COOLING RATE CALCULATIONS IN OPERATIONAL GENERAL-CIRCULATION MODELS - COMPARISONS WITH BENCHMARK COMPUTATIONS SO JOURNAL OF GEOPHYSICAL RESEARCH-ATMOSPHERES LA English DT Article ID LINE PARAMETERS COMPILATION; LAST GLACIAL MAXIMUM; GLOBAL CLIMATE; CARBON-DIOXIDE; CONTINUUM ABSORPTION; CRETACEOUS CLIMATE; DYNAMICAL RESPONSE; RADIATIVE-TRANSFER; MIDDLE ATMOSPHERE; CO2 CONCENTRATION AB As part of the Intercomparison of Radiation Codes in Climate Models (ICRCCM) project, careful comparisons of the performance of a large number of radiation codes were carried out, and the results compared with those of benchmark calculations. In this paper, we document the performance of a number of parameterized models which have been heavily used in climate and numerical prediction research at three institutions: Geophysical Fluid Dynamics Laboratory (GFDL), National Center for Atmospheric Research (NCAR), and Goddard Institute for Space Studies (GISS). C1 NASA, GODDARD INST SPACE STUDIES, NEW YORK, NY 10025 USA. NATL CTR ATMOSPHER RES, CLIMATE MODELING SECT, BOULDER, CO 80307 USA. RP FELS, SB (reprint author), PRINCETON UNIV, NOAA, GEOPHYS FLUID DYNAM LAB, POB 308, PRINCETON, NJ 08542 USA. RI Lacis, Andrew/D-4658-2012 NR 68 TC 14 Z9 14 U1 0 U2 0 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 MAY 20 PY 1991 VL 96 IS D5 BP 9105 EP 9120 DI 10.1029/91JD00516 PG 16 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA FN179 UT WOS:A1991FN17900014 ER PT J AU RAMASWAMY, V FREIDENREICH, SM AF RAMASWAMY, V FREIDENREICH, SM TI SOLAR RADIATIVE LINE-BY-LINE DETERMINATION OF WATER-VAPOR ABSORPTION AND WATER CLOUD EXTINCTION IN INHOMOGENEOUS ATMOSPHERES SO JOURNAL OF GEOPHYSICAL RESEARCH-ATMOSPHERES LA English DT Article ID CLIMATE MODELS; PARAMETERIZATION; APPROXIMATION; COMPUTATIONS; SCATTERING; BUDGET AB The complete available spectral features (line-by-line, or LBL) of the water vapor molecule in the solar spectrum and a precise treatment of particulate scattering are employed to obtain and analyze the solar radiative fluxes and heating rates in plane-parallel, vertically inhomogeneous model atmospheres containing vapor only, water cloud only, and vapor-plus-cloud present simultaneously. These studies are part of the Intercomparison of Radiation Codes in Climate Models (ICRCCM) project and constitute useful benchmark computations against which results from simpler radiation algorithms can be compared. The "exact" solution of the radiative transfer equation for cloudy atmospheres with the cloud in a single model layer consumes an exorbitant amount of computational resources (approximately 100 hours on a Cyber 205). Two other techniques that are considerably more economical are also investigated. These techniques, too, are based on the LBL spectral features of the H2O molecule but consist of an approximation in either the vapor optical depth or in the multiple-scattering process. The technique involving the "binning" of the vapor optical depths yields extremely accurate fluxes and heating rates for both the vapor and vapor-plus-cloud cases; in particular, it is a practical alternative for obtaining benchmark solutions to the solar radiative transfer in overcast atmospheres (3.8 hours). In contrast, the multiple-scattering approximation technique does not yield precise results; however, considering its computational efficiency (0.5 hours), it offers a rapid means to obtain a first-order approximation of the spectrally integrated quantities. The analyses of the alternate techniques suggest their potential use for high spectral resolution sensitivity studies of the radiative effects due to various types of clouds. C1 NOAA, GEOPHYS FLUID DYNAM LAB, PRINCETON, NJ 08542 USA. RP RAMASWAMY, V (reprint author), PRINCETON UNIV, PROGRAM ATMOSPHER & OCEAN SCI, FORRESTAL CAMPUS, POB 308, PRINCETON, NJ 08542 USA. NR 28 TC 43 Z9 43 U1 1 U2 4 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 MAY 20 PY 1991 VL 96 IS D5 BP 9133 EP 9157 DI 10.1029/90JD00083 PG 25 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA FN179 UT WOS:A1991FN17900016 ER PT J AU PARRISH, DD TRAINER, M BUHR, MP WATKINS, BA FEHSENFELD, FC AF PARRISH, DD TRAINER, M BUHR, MP WATKINS, BA FEHSENFELD, FC TI CARBON-MONOXIDE CONCENTRATIONS AND THEIR RELATION TO CONCENTRATIONS OF TOTAL REACTIVE OXIDIZED NITROGEN AT 2 RURAL UNITED-STATES SITES SO JOURNAL OF GEOPHYSICAL RESEARCH-ATMOSPHERES LA English DT Article ID EARTHS ATMOSPHERE; NIWOT-RIDGE; TROPOSPHERE; COLORADO; NOY; REDUCTION; CHEMISTRY; NITRATE; METHANE; OXIDES AB Concentrations of CO and NO(y) (total reactive oxidized nitrogen species) were measured simultaneously with many other atmospheric parameters, including SO2 concentration and wind direction, during three field studies (two rural and one suburban). The CO concentrations at the two rural sites can be described approximately by lognormal distributions, with the Scotia, Pennsylvania, site exhibiting higher levels (geometric mean, 214 parts per billion by volume (ppbv); standard deviation of the logarithms, 0.143) than Niwot Ridge, Colorado (geometric mean, 121 ppbv; standard deviation of the logarithms, 0.175). As expected, measurements made at Niwot Ridge when the wind was from the east, the direction of the principal nearby urban area, exhibited the highest CO levels. At Scotia, power-plant-dominated air parcels could be identified by larger [SO2] to [NO(y)] ratios and were characterized by smaller [CO] to [NO(y)] ratios. Simultaneous measurements of [CO] and [NO(y)] allowed the identification of air parcels that arrived at Niwot Ridge and Boulder (the suburban site) without significant recent anthropogenic input. The CO levels in these parcels were consistent with the tropospheric background concentration of CO at 40-degrees-N latitude: approximately 84 ppbv in late summer and 127 ppbv in early spring. The [CO] to [NO(y)] ratios observed in the Boulder suburban study provide a test for, and are consistent with, available emission inventories for these pollutants. At Niwot Ridge in east winds the observed ratios are consistent with the ratios expected from emission inventories, modified by photochemical transformation on time scales that are reasonable for transport from the location of emission to the measurement site. However, the rural data sets were not able to provide stringent tests of emission inventories. C1 UNIV COLORADO, NOAA, COOPERAT INST RES ENVIRONM SCI, BOULDER, CO 80309 USA. RP PARRISH, DD (reprint author), NOAA, ENVIRONM RES LAB, AERON LAB, R-E-AL7, 325 S BROADWAY, BOULDER, CO 80303 USA. RI Parrish, David/E-8957-2010; Trainer, Michael/H-5168-2013; Fehsenfeld, Frederick/I-4876-2013 OI Parrish, David/0000-0001-6312-2724; NR 39 TC 105 Z9 105 U1 1 U2 4 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 MAY 20 PY 1991 VL 96 IS D5 BP 9309 EP 9320 DI 10.1029/91JD00047 PG 12 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA FN179 UT WOS:A1991FN17900027 ER PT J AU STEIN, DL MELENDEZ, R KONG, I AF STEIN, DL MELENDEZ, R KONG, I TI A REVIEW OF CHILEAN SNAILFISHES (LIPARIDIDAE, SCORPAENIFORMES) WITH DESCRIPTIONS OF A NEW GENUS AND 3 NEW SPECIES SO COPEIA LA English DT Article AB Liparidids constitute a speciose cottoid family that is distributed worldwide. Recent studies show that, contrary to previous belief, many species occur on the west coast of South America and in the Antarctic Ocean. Liparidid material from the coast of Chile between the intertidal and the mid-depths of the continental slope includes four genera and 11 species. Of these, two are new species of Paraliparis: Paraliparis molinai and P. merodontus. One, Eknomoliparis chirichignoae, represents a new genus and species. Four of the seven described species have been reported only once: Careproctus crassus, C. pallidus, Liparis antarctica, and P. debueni. One undescribed species is known from a single damaged specimen. The remaining three species, C. falklandica, P. anarthractae, and P. eltanini, are better known. In this paper we review the known material, describe the new genus and three new species, redescribe and discuss poorly known early material, diagnose the remaining species, and provide an inclusive key. C1 MUSEO NACL HIST NAT,SANTIAGO,CHILE. UNIV ANTOFAGASTA,INST INVEST OCEANOL,ANTOFAGASTA,CHILE. NOAA,NURP R OR-2,SILVER SPRING,MD 20910. RP STEIN, DL (reprint author), OREGON STATE UNIV,COLL OCEANOG,CORVALLIS,OR 97331, USA. NR 28 TC 10 Z9 10 U1 0 U2 0 PU AMER SOC ICHTHYOLOGISTS HERPETOLOGISTS BUSINESS OFFICE PI CARBONDALE PA SOUTHERN ILLINOIS UNIV, DEPT ZOOLOGY, CARBONDALE, IL 62901-6501 SN 0045-8511 J9 COPEIA JI Copeia PD MAY 16 PY 1991 IS 2 BP 358 EP 373 PG 16 WC Zoology SC Zoology GA FM352 UT WOS:A1991FM35200008 ER PT J AU NORTHROP, DM MARTIRE, DE MACCREHAN, WA AF NORTHROP, DM MARTIRE, DE MACCREHAN, WA TI SEPARATION AND IDENTIFICATION OF ORGANIC GUNSHOT AND EXPLOSIVE CONSTITUENTS BY MICELLAR ELECTROKINETIC CAPILLARY ELECTROPHORESIS SO ANALYTICAL CHEMISTRY LA English DT Article ID OPEN-TUBULAR CAPILLARIES; RESIDUE ANALYSIS; CHROMATOGRAPHY AB Micellar electrokinetic capillary electrophoresis (MECE) provides rapid and efficient separation and detection of organic gunshot and explosive consitituents. Twenty-six of these constituents were separated in under 10 min with efficiencies in excess of 200 000 theoretical plates. The effects of the following experimental parameters were studied: sodium dodecyl sulfate (SDS) concentration, pH, addition of a tetraalkylammonium salt, capillary diameter, and injection times. The presence of gunshot residues in spent ammunition casings and the composition of six reloading powders and four plastic explosives were determined by using the MECE method. Multiple-wavelength analysis provided UV spectral profiles of the constituents for use with selective wavelength monitoring. C1 NATL INST STAND & TECHNOL,DIV ORGAN ANALYT RES,GAITHERSBURG,MD 20899. GEORGETOWN UNIV,DEPT CHEM,WASHINGTON,DC 20057. NR 21 TC 84 Z9 86 U1 1 U2 13 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 SN 0003-2700 J9 ANAL CHEM JI Anal. Chem. PD MAY 15 PY 1991 VL 63 IS 10 BP 1038 EP 1042 DI 10.1021/ac00010a021 PG 5 WC Chemistry, Analytical SC Chemistry GA FL305 UT WOS:A1991FL30500023 ER PT J AU LOWNEY, JR BENNETT, HS AF LOWNEY, JR BENNETT, HS TI MAJORITY AND MINORITY ELECTRON AND HOLE MOBILITIES IN HEAVILY DOPED GAAS SO JOURNAL OF APPLIED PHYSICS LA English DT Article ID P-TYPE GAAS; IMPURITY-SCATTERING; SILICON; TRANSPORT; SEMICONDUCTORS; SIMULATION AB The majority electron and minority hole mobilities have been calculated in GaAs for donor densities between 5 x 10(16) and 1 x 10(19) cm-3. Similarly, the majority hole and minority electron mobilities have been calculated for acceptor densities between 5 x 10(16) and 1 x 10(20) cm-3. All the important scattering mechanisms have been included. The ionized impurity and carrier-carrier scattering processes have been treated with a phase-shift analysis. These calculations are the first to use a phase-shift analysis for minority carriers scattering from majority carriers. The results are in good agreement with experiment, but predict that at high dopant densities minority mobilities should increase with increasing dopant density for a short range of densities. This effect occurs because of the reduction of plasmon scattering and the removal of carriers from carrier-carrier scattering because of the Pauli exclusion principle. Some recent experiments support this finding. These calculations do not treat the density-of-states modifications due to heavy doping, which should have only a small effect on the mobility at room temperature. The results are important for device modeling because of the need to have values for minority mobilities. RP LOWNEY, JR (reprint author), NATL INST STAND & TECHNOL,DIV SEMICOND ELECTR,GAITHERSBURG,MD 20899, USA. NR 33 TC 83 Z9 83 U1 2 U2 16 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 MAY 15 PY 1991 VL 69 IS 10 BP 7102 EP 7110 DI 10.1063/1.347650 PG 9 WC Physics, Applied SC Physics GA FM771 UT WOS:A1991FM77100041 ER PT J AU POLAK, ML FIALA, BL ERVIN, KM LINEBERGER, WC AF POLAK, ML FIALA, BL ERVIN, KM LINEBERGER, WC TI THE ULTRAVIOLET PHOTOELECTRON-SPECTRUM OF SO- SO JOURNAL OF CHEMICAL PHYSICS LA English DT Letter ID ELECTRONIC STATES; SPECTROSCOPY C1 UNIV COLORADO,NATL INST STAND & TECHNOL,JOINT INST LAB ASTROPHYS,BOULDER,CO 80309. RP POLAK, ML (reprint author), UNIV COLORADO,DEPT CHEM & BIOCHEM,BOULDER,CO 80309, USA. NR 17 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 MAY 15 PY 1991 VL 94 IS 10 BP 6926 EP 6927 DI 10.1063/1.460223 PG 2 WC Chemistry, Physical; Physics, Atomic, Molecular & Chemical SC Chemistry; Physics GA FL001 UT WOS:A1991FL00100065 ER PT J AU HANSON, HP CORNILLON, P HALLIWELL, GR HALLIWELL, V AF HANSON, HP CORNILLON, P HALLIWELL, GR HALLIWELL, V TI CLIMATOLOGICAL PERSPECTIVES, OCEANOGRAPHIC AND METEOROLOGICAL, ON VARIABILITY IN THE SUBTROPICAL CONVERGENCE ZONE IN THE NORTHWESTERN ATLANTIC SO JOURNAL OF GEOPHYSICAL RESEARCH-OCEANS LA English DT Article ID OCEAN; FRONTOGENESIS AB We discuss the large-scale setting for the Frontal Air-Sea Interaction Experiment (FASINEX). A climatology of the west-central North Atlantic, derived from various data sets, is presented, and the meteorological and oceanographic context for FASINEX is thereby established. While the atmospheric and oceanic processes of interest during the intensive phases of FASINEX are not resolved in this large-scale study, we are able to show how these scales produce an environment favorable to the smaller-scale processes of frontogenesis that are the subject of other contributions in this issue. C1 UNIV RHODE ISL,GRAD SCH OCEANOG,NARRAGANSETT,RI 02882. RP HANSON, HP (reprint author), UNIV COLORADO,NOAA,COOPERAT INST RES ENVIRONM SCI,BOULDER,CO 80309, USA. RI Halliwell, George/B-3046-2011 OI Halliwell, George/0000-0003-4216-070X NR 25 TC 15 Z9 15 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-OCEANS JI J. Geophys. Res.-Oceans PD MAY 15 PY 1991 VL 96 IS C5 BP 8517 EP 8529 DI 10.1029/90JC02487 PG 13 WC Oceanography SC Oceanography GA FM099 UT WOS:A1991FM09900002 ER PT J AU FRIEHE, CA SHAW, WJ ROGERS, DP DAVIDSON, KL LARGE, WG STAGE, SA CRESCENTI, GH KHALSA, SJS GREENHUT, GK LI, F AF FRIEHE, CA SHAW, WJ ROGERS, DP DAVIDSON, KL LARGE, WG STAGE, SA CRESCENTI, GH KHALSA, SJS GREENHUT, GK LI, F TI AIR-SEA FLUXES AND SURFACE-LAYER TURBULENCE AROUND A SEA-SURFACE TEMPERATURE FRONT SO JOURNAL OF GEOPHYSICAL RESEARCH-OCEANS LA English DT Article ID CONVECTIVE BOUNDARY-LAYER; SIMULATIONS; DEPENDENCE; AIRCRAFT; FIELD AB The response of the lower marine atmospheric boundary layer to sharp changes in sea surface temperature was studied in the Frontal Air-Sea Interaction Experiment (FASINEX) with aircraft and ships measuring mean and turbulence quantities, sea surface temperature, and wave state. Changing synoptic weather on 3 successive days provided cases of wind direction both approximately parallel and perpendicular to a surface temperature front. For the wind perpendicular to the front, both wind over cold-to-warm and warm-to-cold surface temperatures occurred. For the cold-to-warm case, the unstable boundary layer was observed to thicken, with increased convective activity on the warm side. For the warm-to-cold case, the surface layer buoyant stability changed from unstable to neutral or slightly stable, and the sea state and turbulence structure in the lower 100 m were immediately altered, with a large decrease in stress and slowing of the wind. Measurements for this case with two aircraft in formation at 30 and 100 m show a slightly increased stress divergence on the cold side. The turbulent velocity variances changed anisotropically across the front: the streamwise variance was practically unchanged, whereas the vertical and cross-stream variances decreased. Model results, consistent with the observations, suggest that an internal boundary layer forms at the sea surface temperature front. The ocean wave, swell, and microwave radar backscatter fields were measured from several aircraft which flew simultaneously with the low-level turbulence aircraft. Significant reductions in backscatter and wave height were observed on the cold side of the front. C1 USN,POSTGRAD SCH,DEPT METEOROL,MONTEREY,CA 93940. UNIV CALIF SAN DIEGO,SCRIPPS INST OCEANOG,LA JOLLA,CA 92093. NATL CTR ATMOSPHER RES,BOULDER,CO 80307. FLORIDA STATE UNIV,DEPT METEOROL,TALLAHASSEE,FL 32306. WOODS HOLE OCEANOG INST,WOODS HOLE,MA 02543. UNIV COLORADO,NOAA,COOPERAT INST RES ENVIRONM SCI,BOULDER,CO 80309. NOAA,ENVIRONM RES LAB,BOULDER,CO 80303. CALTECH,JET PROP LAB,PASADENA,CA 91109. RP FRIEHE, CA (reprint author), UNIV CALIF IRVINE,DEPT MECH ENGN,IRVINE,CA 92717, USA. RI KHalsa, Siri Jodha/A-9338-2009 OI KHalsa, Siri Jodha/0000-0001-9217-5550 NR 33 TC 124 Z9 125 U1 0 U2 5 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 SN 0148-0227 J9 J GEOPHYS RES-OCEANS JI J. Geophys. Res.-Oceans PD MAY 15 PY 1991 VL 96 IS C5 BP 8593 EP 8609 DI 10.1029/90JC02062 PG 17 WC Oceanography SC Oceanography GA FM099 UT WOS:A1991FM09900006 ER PT J AU MELLOR, GL EZER, T AF MELLOR, GL EZER, T TI A GULF-STREAM MODEL AND AN ALTIMETRY ASSIMILATION SCHEME SO JOURNAL OF GEOPHYSICAL RESEARCH-OCEANS LA English DT Article ID OCEAN CIRCULATION MODEL; HUDSON-RARITAN ESTUARY; SEA-LEVEL DIFFERENCES; 3-DIMENSIONAL SIMULATION; PRIMITIVE EQUATION; ATLANTIC BIGHT; DELAWARE BAY; RIVER SYSTEM; GEOSAT; MEANDER AB A continuous data assimilation scheme and a multilayer, primitive equation, numerical model are described. The model is an eddy-resolving, coastal ocean model that has been extended to include the Gulf Stream region. It has complete thermohaline dynamics, a bottom-following, sigma, vertical coordinate system, and a coastal-following, curvilinear orthogonal, horizontal coordinate system. Calculated model fields are used to provide a model climatology and correlations between subsurface temperature and salinity anomalies and surface elevation anomalies. An optimal interpolation method, the surface to subsurface correlations, and estimated model and data errors are the basis of the assimilation technique. Altimetry anomaly data extracted from the model calculations according to the Geosat orbital schedule are used to test the assimilation scheme and to provide nowcasts and forecasts. Sensitivity studies are performed to test the effects of various parameters of the scheme. It is found that the scheme is less efficient in the shallow continental shelf area than in the deeper regions of the model. The results show significant nowcast skill, with area-averaged rms error for surface elevation and subsurface properties of about 40-50% of the corresponding error of the unassimilated case. Good forecast skill, better than persistence, is demonstrated for 10-20 days; there is little skill after 30-40 days. Increasing the density of the satellite altimetry data (especially by decreasing the separation distance between tracks) should decrease the nowcast rms error to about 15% and improve the forecast. RP MELLOR, GL (reprint author), PRINCETON UNIV,PROGRAM ATMOSPHER & OCEAN SCI,PRINCETON,NJ 08544, USA. OI Ezer, Tal/0000-0002-2018-6071 NR 34 TC 142 Z9 151 U1 0 U2 5 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 SN 0148-0227 J9 J GEOPHYS RES-OCEANS JI J. Geophys. Res.-Oceans PD MAY 15 PY 1991 VL 96 IS C5 BP 8779 EP 8795 DI 10.1029/91JC00383 PG 17 WC Oceanography SC Oceanography GA FM099 UT WOS:A1991FM09900019 ER PT J AU TAGZIRIA, H PAUWELS, J VERDONK, J VANGESTEL, J EYKENS, R GILLIAM, DM SCOTT, RD BYRNE, J DAWBER, P AF TAGZIRIA, H PAUWELS, J VERDONK, J VANGESTEL, J EYKENS, R GILLIAM, DM SCOTT, RD BYRNE, J DAWBER, P TI PROBLEMS RELATED TO THE DETERMINATION OF MASS DENSITIES OF EVAPORATED REFERENCE DEPOSITS SO NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH SECTION A-ACCELERATORS SPECTROMETERS DETECTORS AND ASSOCIATED EQUIPMENT LA English DT Article; Proceedings Paper CT 15TH WORLD CONF OF THE INTERNATIONAL NUCLEAR TARGET SAFETY DEVELOPMENT SOC : SPECIAL HIGH PURITY MATERIALS AND TARGETS CY SEP 10-14, 1990 CL SANTA FE, NM SP INT NUCL TARGET SAFETY DEV SOC AB The accurate characterization of the surface density (nuclei/cm2) of thin isotopic deposits is of highest importance in certain experiments. If accuracies better than +/- 0.5% are to be quoted, careful consideration of seemingly minor effects is necessary, as these effects may generate serious errors. The radial surface density distribution in the central region of the target disks, the thickness profile at the edges, and the evaluation of effective deposit diameters are discussed for the case of measurements and observations made during the preparation and characterization of (LiF)-Li-6 and B-10 reference deposits, which were employed in a recent determination of the free neutron lifetime. Theoretical calculations are in excellent agreement with the experimental results. C1 NATL INST STAND & TECHNOL,GAITHERSBURG,MD 20899. SCOTTISH UNIV RES & REACTOR CTR,E KILBRIDE G75 0QU,LANARK,SCOTLAND. UNIV SUSSEX,SCH MATH & PHYS SCI,BRIGHTON BN1 9QH,E SUSSEX,ENGLAND. RP TAGZIRIA, H (reprint author), COMMISS EUROPEAN COMMUNITIES,JOINT RES CTR,CENT BUR NUCL MEASUREMENTS,RES & DEV PROGRAMME,B-2440 GEEL,BELGIUM. NR 8 TC 11 Z9 11 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 MAY 15 PY 1991 VL 303 IS 1 BP 123 EP 132 DI 10.1016/0168-9002(91)90775-L PG 10 WC Instruments & Instrumentation; Nuclear Science & Technology; Physics, Nuclear; Physics, Particles & Fields SC Instruments & Instrumentation; Nuclear Science & Technology; Physics GA FR338 UT WOS:A1991FR33800022 ER PT J AU PAUWELS, J EYKENS, R LAMBERTY, A VANGESTEL, J TAGZIRIA, H SCOTT, RD BYRNE, J DAWBER, PG GILLIAM, DM AF PAUWELS, J EYKENS, R LAMBERTY, A VANGESTEL, J TAGZIRIA, H SCOTT, RD BYRNE, J DAWBER, PG GILLIAM, DM TI THE PREPARATION AND CHARACTERIZATION OF (LIF)-LI-6 AND B-10 REFERENCE DEPOSITS FOR THE MEASUREMENT OF THE NEUTRON LIFETIME SO NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH SECTION A-ACCELERATORS SPECTROMETERS DETECTORS AND ASSOCIATED EQUIPMENT LA English DT Article; Proceedings Paper CT 15TH WORLD CONF OF THE INTERNATIONAL NUCLEAR TARGET SAFETY DEVELOPMENT SOC : SPECIAL HIGH PURITY MATERIALS AND TARGETS CY SEP 10-14, 1990 CL SANTA FE, NM SP INT NUCL TARGET SAFETY DEV SOC AB In beam experiments, the achievement of an accurate neutron lifetime measurements depends heavily on the use of well characterised boron and/or lithium reference deposits to assess the neutron density. Sets of (LiF)-Li-6 and B-10 reference deposits on silicon wafers were prepared by vacuum deposition using planetary rotating substrate holders. The uniformity of deposition was investigated using visible light spectrophotometry and accurate dimensional characterisation was carried out on the basis of travelling microscope and Talistep measurements. The results obtained agreed well with theoretical calculations based on the geometry of the evaporation system. The deposits prepared in successive evaporation runs were then characterised by neutron induced charged particle measurements, calibrated by isotope dilution mass spectrometry. Li-6 and B-10 surface densities are certified with accuracies of 0.35-0.50% and 0.30-0.41%, respectively. An intercomparison of the Li-6 and B-10 calibrations confirms the consistency of the measurements. C1 SCOTTISH UNIV RES & REACTOR CTR,E KILBRIDE G75 0QU,LANARK,SCOTLAND. UNIV SUSSEX,SCH MATH & PHYS SCI,BRIGHTON BN1 9QH,E SUSSEX,ENGLAND. NATL INST STAND & TECHNOL,GAITHERSBURG,MD 20899. RP PAUWELS, J (reprint author), COMMISS EUROPEAN COMMUNITIES,JOINT RES CTR,CENT BUR NUCL MEASUREMENTS,RES & DEV PROGRAMME,B-2440 GEEL,BELGIUM. NR 10 TC 12 Z9 12 U1 0 U2 3 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0168-9002 J9 NUCL INSTRUM METH A JI Nucl. Instrum. Methods Phys. Res. Sect. A-Accel. Spectrom. Dect. Assoc. Equip. PD MAY 15 PY 1991 VL 303 IS 1 BP 133 EP 140 DI 10.1016/0168-9002(91)90776-M PG 8 WC Instruments & Instrumentation; Nuclear Science & Technology; Physics, Nuclear; Physics, Particles & Fields SC Instruments & Instrumentation; Nuclear Science & Technology; Physics GA FR338 UT WOS:A1991FR33800023 ER PT J AU VEASEY, DL HICKERNELL, RK LARSON, DR BATCHMAN, TE AF VEASEY, DL HICKERNELL, RK LARSON, DR BATCHMAN, TE TI WAVE-GUIDE POLARIZERS WITH HYDROGENATED AMORPHOUS-SILICON CLADDINGS SO OPTICS LETTERS LA English DT Article ID WAVE-GUIDES AB We have fabricated TE- and TM-pass waveguide polarizers with polarization isolations of 42 and 35 dB, respectively. The devices were fabricated by the growth of hydrogenated amorphous silicon claddings on K+-Na+ ion-exchanged channel waveguides in glass. Cladding thicknesses were accurately tuned to permit optimum coupling of either a TE or a TM mode to the cladding. We have also demonstrated that a waveguide polarizer attenuation as high as 760 dB/cm can be measured by using a photothermal deflection technique. C1 UNIV OKLAHOMA,SCH ENGN & COMP SCI,NORMAN,OK 73019. RP VEASEY, DL (reprint author), NATL INST STAND & TECHNOL,325 BROADWAY,BOULDER,CO 80303, USA. NR 6 TC 10 Z9 10 U1 0 U2 3 PU OPTICAL SOC AMER PI WASHINGTON PA 2010 MASSACHUSETTS AVE NW, WASHINGTON, DC 20036 SN 0146-9592 J9 OPT LETT JI Opt. Lett. PD MAY 15 PY 1991 VL 16 IS 10 BP 717 EP 719 DI 10.1364/OL.16.000717 PG 3 WC Optics SC Optics GA FK894 UT WOS:A1991FK89400007 PM 19774048 ER PT J AU PERKINS, RA RODER, HM FRIEND, DG DECASTRO, CAN AF PERKINS, RA RODER, HM FRIEND, DG DECASTRO, CAN TI THE THERMAL-CONDUCTIVITY AND HEAT-CAPACITY OF FLUID NITROGEN SO PHYSICA A LA English DT Article ID MODERATELY DENSE GAS; CRITICAL REGION; TRANSPORT-COEFFICIENTS; CARBON-MONOXIDE; TEMPERATURE; PRESSURES; ARGON; MPA; MIXTURES AB This paper presents new absolute measurements of the thermal conductivity and the thermal diffusivity of nitrogen made with a transient hot wire instrument. The instrument measures the thermal conductivity with an uncertainty less than +/- 1% and the thermal diffusivity with an uncertainty of +/- 5% except at the fluid critical point. The data cover the region from 80 to 300 K at pressures to 70 MPa. The data consist of 8 supercritical isotherms, 3 vapor isotherms, and 4 liquid isotherms. A surface fit is developed for our nitrogen thermal conductivity data from 80 to 300 K at pressures to 70 MPa. The data are compared with a recent theory for the first density coefficient of thermal conductivity and a new mode-coupling theory for the thermal conductivity critical enhancement. These data illustrate that it is necessary to study a fluid over a wide range of temperatures and densities in order to characterize the thermal conductivity surface. Isobaric heat capacity results were determined from the simultaneously measured values of thermal conductivity and thermal diffusivity, using the density calculated from an equation of state. The heat capacities obtained by this technique are compared to the heat capacities predicted by a recent equation of state developed specifically for nitrogen. C1 UNIV LISBON,FAC CIENCIAS,DEPT QUIM,P-1700 LISBON,PORTUGAL. CTR QUIM ESTRUTURAL,P-1096 LISBON,PORTUGAL. RP PERKINS, RA (reprint author), NATL INST STAND & TECHNOL,DIV THERMOPHYS,BOULDER,CO 80303, USA. RI Nieto de Castro, Carlos/B-7377-2011; OI Nieto de Castro, Carlos/0000-0001-9011-5132; Perkins, Richard/0000-0002-8526-6742 NR 49 TC 49 Z9 49 U1 2 U2 8 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0378-4371 J9 PHYSICA A JI Physica A PD MAY 15 PY 1991 VL 173 IS 3 BP 332 EP 362 DI 10.1016/0378-4371(91)90368-M PG 31 WC Physics, Multidisciplinary SC Physics GA FR035 UT WOS:A1991FR03500003 ER PT J AU WATSON, RE BENNETT, LH AF WATSON, RE BENNETT, LH TI CRYSTALLINE AND GLASSY PHASES OF TRANSITION-METAL METALLOID SYSTEMS SO PHYSICAL REVIEW B LA English DT Article ID ALLOYS; ND2FE14B AB Glasses formed in the Ni-P and Fe-B systems are known to be polymorphic. The crystalline phases in these systems display markedly different metalloid environments and a one-to-one relationship can be made between those environments and the glassy phases for Ni-P. It is the purpose of the present paper to explore the prospects for polymorphism in other transition-metal-rich metalloid glassy systems in which the metalloids are P, Si, B, C, and N. The known crystal structures of the phosphides, silicides, carbides, nitrides, and borides have been inspected using radical Voronoi (Wigner-Seitz) -cell constructs to deduce metalloid-site nearest-neighbor arrangements. The occurrence of differences, such as those obtained in Ni-P and Fe-B, is taken as indicative of possible polymorphism in the glasses. A list of such glasses has been constructed. It is seen that polymorphism is most likely to occur in the phosphides and silicides, and very unlikely in the nitrides. C1 NATL INST STAND & TECHNOL,GAITHERSBURG,MD 20899. RP WATSON, RE (reprint author), BROOKHAVEN NATL LAB,UPTON,NY 11973, USA. NR 25 TC 17 Z9 17 U1 1 U2 4 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 0163-1829 J9 PHYS REV B JI Phys. Rev. B PD MAY 15 PY 1991 VL 43 IS 14 BP 11642 EP 11652 DI 10.1103/PhysRevB.43.11642 PG 11 WC Physics, Condensed Matter SC Physics GA FM463 UT WOS:A1991FM46300010 ER PT J AU BENZ, SP BURROUGHS, CJ AF BENZ, SP BURROUGHS, CJ TI COHERENT EMISSION FROM 2-DIMENSIONAL JOSEPHSON JUNCTION ARRAYS SO APPLIED PHYSICS LETTERS LA English DT Article ID PHASE-LOCKING AB Coherent emission has been generated by two-dimensional arrays of SIS Josephson junctions and detected in a junction coupled to the array through a dc-blocking capacitor. The detector junction exhibits Shapiro steps at frequencies corresponding to the voltage across single array junctions and ranging from 60 to 210 GHz. The maximum power coupled to the detector junction occurs at 150 GHz and is estimated to be 0.4-mu-W, based on simulations of the detector circuit. Possible mechanisms for coherent emission from two-dimensional arrays are discussed. RP BENZ, SP (reprint author), NATL INST STAND & TECHNOL, BOULDER, CO 80303 USA. NR 15 TC 130 Z9 134 U1 2 U2 6 PU AMER INST PHYSICS PI MELVILLE PA 1305 WALT WHITMAN RD, STE 300, MELVILLE, NY 11747-4501 USA SN 0003-6951 EI 1077-3118 J9 APPL PHYS LETT JI Appl. Phys. Lett. PD MAY 13 PY 1991 VL 58 IS 19 BP 2162 EP 2164 DI 10.1063/1.104993 PG 3 WC Physics, Applied SC Physics GA FL317 UT WOS:A1991FL31700037 ER PT J AU YOO, JN SPERLING, LH GLINKA, CJ KLEIN, A AF YOO, JN SPERLING, LH GLINKA, CJ KLEIN, A TI CHARACTERIZATION OF FILM FORMATION FROM POLYSTYRENE LATEX-PARTICLES VIA SANS .2. HIGH-MOLECULAR-WEIGHT SO MACROMOLECULES LA English DT Article ID ANGLE NEUTRON-SCATTERING; SPINODAL DECOMPOSITION; RECOIL SPECTROMETRY; AMORPHOUS POLYMERS; DIFFUSION; INTERFACE; BULK; INTERDIFFUSION; COALESCENCE; DEPENDENCE AB The interdiffusion of polymer chains during film formation from high molecular weight (M(w) congruent-to 2 000 000) polystyrene latex particles of about 270-angstrom radius was characterized by small-angle neutron scattering (SANS) and correlated with the development of tensile strength of the resulting films. After an apparent induction period, tensile strength increases with annealing time. Full tensile strength was achieved at a penetration depth of 30-35 angstrom, comparable to the radius of gyration of the critical entanglement molecular weight of polystyrene (32 000 g/mol). Two critical parameters in the interdiffusion process of film formation from latex particles are proposed: the location of chain ends and the dimensionless ratio of the polymer chain's radii of gyration to the latex particle's radius. C1 LEHIGH UNIV, CTR POLYMER SCI & ENGN, BETHLEHEM, PA 18015 USA. LEHIGH UNIV, MAT RES CTR, BETHLEHEM, PA 18015 USA. LEHIGH UNIV, DEPT CHEM ENGN, BETHLEHEM, PA 18015 USA. LEHIGH UNIV, DEPT MAT SCI & ENGN, BETHLEHEM, PA 18015 USA. LEHIGH UNIV, INST EMULS POLYMER, WHITAKER LAB 5, BETHLEHEM, PA 18015 USA. NATL INST STAND & TECHNOL, INST MAT SCI & ENGN, GAITHERSBURG, MD 20899 USA. NR 56 TC 84 Z9 84 U1 1 U2 2 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 0024-9297 EI 1520-5835 J9 MACROMOLECULES JI Macromolecules PD MAY 13 PY 1991 VL 24 IS 10 BP 2868 EP 2876 DI 10.1021/ma00010a036 PG 9 WC Polymer Science SC Polymer Science GA FL697 UT WOS:A1991FL69700036 ER PT J AU SCHMUTZ, W LEITHERER, C HUBENY, I VOGEL, M HAMANN, WR WESSOLOWSKI, U AF SCHMUTZ, W LEITHERER, C HUBENY, I VOGEL, M HAMANN, WR WESSOLOWSKI, U TI NON-LTE ANALYSIS OF THE OFPE/WN9 STAR HDE-269227 (R84) SO ASTROPHYSICAL JOURNAL LA English DT Article DE RADIATIVE TRANSFER; STARS, ABUNDANCES; STARS, ATMOSPHERES; STARS, INDIVIDUAL (HDE-269227); STARS, WINDS; STARS, WOLF-RAYET ID WOLF-RAYET STARS; LARGE MAGELLANIC CLOUD; APPROXIMATE LAMBDA-OPERATORS; DRIVEN STELLAR WINDS; LARGE MASS OUTFLOWS; EXPANDING ATMOSPHERES; CIRCUMSTELLAR SHELLS; SPECTRAL-ANALYSIS; LINE FORMATION; B/BE STARS AB A spectral analysis of the Ofpe/WN9 star HD 269227 (R84) is presented. The equations of radiative transfer are solved for a spherically expanding atmosphere. A non-LTE model is used to predict the spectrum of hydrogen and helium. In almost all cases, the calculated and observed line profiles agree within observational error. The stellar parameters determined for R84 are L = 10(5.7) L., T(eff) = 28,500 K, R* = 30 R., M = 10(-4.6) M. yr-1, V infinity = 400 km s-1, and Y = 0.63 by mass. Since the blueshift of the helium line P Cygni absorptions depends upon the line strength, the observed helium lines allow the velocity law to be probed from the terminal velocity of the wind down to approximately 35 km s-1. Thus, we can empirically determine the shape of the velocity law. The above stellar parameters are used in a subsequent hydrodynamic calculation assuming that the stellar wind is driven by radiation pressure. This model reproduces both the observed mass-loss rate and the terminal wind velocity. A comparison of computed velocity law with the law determined by the spectroscopic analysis reveals good agreement, which strongly supports the argument that the stellar wind is radiation-driven. The observational opportunity to investigate the wind's velocity law makes Ofpe/WN9 stars ideally suited objects of testing predictions of radiation-driven wind theory. From its stellar parameters R84 can be identified as a star which has lost about half its initial mass. A comparison of the stellar parameters with those calculated from evolutionary models reveals that R84 is probably a post-red supergiant and that it experienced violet mass loss during its red supergiant phase. R84's close spectroscopic similarity to S Doradus variables at minimum visual brightness suggests that these stars have already experienced a phase of violent mass loss in their past during which they lost a significant fraction of their initial mass. Whether or not this enhanced mass loss occurred during the red supergiant phase cannot be determined. C1 NATL INST STAND & TECHNOL,BOULDER,CO. SPACE TELESCOPE SCI INST,BALTIMORE,MD 21218. NATL CTR ATMOSPHER RES,HIGH ALTITUDE OBSERV,BOULDER,CO 80307. SWISS FED INST TECHNOL,INST ASTRON,CH-8092 ZURICH,SWITZERLAND. UNIV KIEL,INST THEORET PHYS & STERNWARTE,W-2300 KIEL 1,GERMANY. RP SCHMUTZ, W (reprint author), UNIV COLORADO,JOINT INST LAB ASTROPHYS,CAMPUS BOX 440,BOULDER,CO 80309, USA. RI Schmutz, Werner/B-4153-2014 OI Schmutz, Werner/0000-0003-1159-5639 NR 95 TC 45 Z9 45 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 MAY 10 PY 1991 VL 372 IS 2 BP 664 EP 682 DI 10.1086/170009 PN 1 PG 19 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA FK241 UT WOS:A1991FK24100027 ER PT J AU DEVRIES, D WAHR, JM AF DEVRIES, D WAHR, JM TI THE EFFECTS OF THE SOLID INNER CORE AND NONHYDROSTATIC STRUCTURE ON THE EARTHS FORCED NUTATIONS AND EARTH TIDES SO JOURNAL OF GEOPHYSICAL RESEARCH-SOLID EARTH AND PLANETS LA English DT Article ID MANTLE BOUNDARY; OCEANLESS EARTH; TOPOGRAPHY; MODEL; DEFORMATION; CONVECTION; EXCITATION; HARMONICS; RETRIEVAL AB Recent highly accurate nutation results from very long baseline interferometry (VLBI) disagree with the 1980 International Astronomical Union (IAU) nutation model by about 2 milliarcseconds (mas). Most of the discrepancy is at the retrograde annual frequency, and it has been interpreted as being due to a nonhydrostatic core-mantle boundary (CMB) ellipticity [Gwinn et al., 1986]. The ellipticity affects the eigenfrequency of the free core nutation (FCN) normal mode, predominantly a relative rotation about an equatorial axis between the fluid outer core (OC) and the solid mantle. This interpretation in terms of a nonhydrostatic CMB shape is consistent with inferences from diurnal tidal gravity measurements [Levine et al., 1986; Neuberg et al., 1987]. The theory that this interpretation is based on assumes that the inner core (IC) is a fluid. Furthermore, the Earth is presumed to be everywhere hydrostatically prestressed, and so it is inconsistent to use results from this theory to infer information about nonhydrostatic structure. In this paper, we extend the theoretical results to include the effects of a solid IC, and of nonhydrostatic structure. The presence of the IC is responsible for a new, nearly diurnal, prograde normal mode (for a hydrostatically prestressed Earth, the frequency is (1 - 1/471) cycles per day) that involves a relative rotation between the IC and OC about an equatorial axis. We call this newly modeled normal mode the free inner core nutation (FICN). The FICN causes a perturbation in the prograde semiannual nutation amplitude of close to 0.2 mas, but the contribution to the retrograde annual nutation is only 0.003 mas, not enough to explain the VLBI discrepancy. Its effects on the diurnal Earth tide are negligible. Nonhydrostatic structure affects the eigenfrequency of this mode and causes the nutation and Earth tide amplitudes to depend on IC-OC boundary, CMB, and outer surface topography at all spatial scales. The dependence, though, falls off as the (l - 1)th power of the ratio of the IC radius divided by the OC radius, for the simplified case of a homogeneous, rigid IC and mantle, and homogeneous, incompressible OC (l, here, is the angular order in the spherical harmonic expansion of the boundary shape). For small l, nonhydrostatic effects on the FICN are of the same order as hydrostatic effects for this specialized case. Neither the IC nor the nonhydrostatic terms significantly affect the conclusions about the values of the CMB ellipticity. C1 UNIV COLORADO,NOAA,COOPERAT INST RES ENVIRONM SCI,BOULDER,CO 80309. RP DEVRIES, D (reprint author), UNIV COLORADO,DEPT PHYS,BOULDER,CO 80309, USA. NR 42 TC 51 Z9 51 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-SOLID PD MAY 10 PY 1991 VL 96 IS B5 BP 8275 EP 8293 DI 10.1029/90JB01958 PG 19 WC Geosciences, Multidisciplinary SC Geology GA FL388 UT WOS:A1991FL38800020 ER PT J AU KLOPPING, FJ PETER, G ROBERTSON, DS BERSTIS, KA MOOSE, RE CARTER, WE AF KLOPPING, FJ PETER, G ROBERTSON, DS BERSTIS, KA MOOSE, RE CARTER, WE TI IMPROVEMENTS IN ABSOLUTE GRAVITY OBSERVATIONS SO JOURNAL OF GEOPHYSICAL RESEARCH-SOLID EARTH AND PLANETS LA English DT Article ID SEA-LEVEL AB In the absolute gravity instruments developed by the Joint Institute for Laboratory Astrophysics (JILA) (Zumberge et al., 1982; Niebauer et al., 1986), the release of the dropped object induces systematic vibration in the floor-gravimeter system. These vibrations can cause significant errors in the observed time-distance values from which the gravitational acceleration is computed. Detailed study of the vibrations affecting the gravity observations shows them to contain random noise and site dependent systematic components, which can be modeled by decaying sinusoids in the range of 10 to 120 Hz. This paper discusses (1) a mathematical filtering method to correct the observed time-distance array by identifying and removing all non-random signals from each individual drop, (2) upgrades of the gravimeter controller, which allow the collection of the data required to implement the mathematical filtering, and (3) mechanical filtering experiments using shock dampening pads and braces to minimize the vibrations. The maximum correction to observed gravity has been 23-mu-Gal using the mathematical filter, typical corrections are in the 2-7-mu-Gal range. The use of the shock dampening devices alone resulted in a three-fold reduction in the amplitudes and decay times of the systematic vibrations. RP KLOPPING, FJ (reprint author), NOAA,NATL OCEAN SERV,NATL GEODET SURVEY,OFF CHARTING & GEODET SERV,ROCKVILLE,MD 20852, USA. NR 8 TC 27 Z9 27 U1 1 U2 1 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 SN 0148-0227 J9 J GEOPHYS RES-SOLID PD MAY 10 PY 1991 VL 96 IS B5 BP 8295 EP 8303 DI 10.1029/91JB00249 PG 9 WC Geosciences, Multidisciplinary SC Geology GA FL388 UT WOS:A1991FL38800021 ER PT J AU WESTBROOK, CI WATTS, RN TANNER, CE ROLSTON, SL PHILLIPS, WD LETT, PD GOULD, PL AF WESTBROOK, CI WATTS, RN TANNER, CE ROLSTON, SL PHILLIPS, WD LETT, PD GOULD, PL TI LOCALIZATION OF ATOMS IN A 3-DIMENSIONAL STANDING WAVE - REPLY SO PHYSICAL REVIEW LETTERS LA English DT Letter C1 UNIV CONNECTICUT,DEPT PHYS,STORRS,CT 06269. RP WESTBROOK, CI (reprint author), NATL INST STAND & TECHNOL,CTR ATOM MOLEC & OPT PHYS,GAITHERSBURG,MD 20899, USA. RI Westbrook, Christoph/B-6092-2009; rolston, steven/L-5175-2013 OI Westbrook, Christoph/0000-0002-6490-0468; rolston, steven/0000-0003-1671-4190 NR 3 TC 0 Z9 0 U1 0 U2 2 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 0031-9007 J9 PHYS REV LETT JI Phys. Rev. Lett. PD MAY 6 PY 1991 VL 66 IS 18 BP 2413 EP 2413 DI 10.1103/PhysRevLett.66.2413 PG 1 WC Physics, Multidisciplinary SC Physics GA FK183 UT WOS:A1991FK18300035 ER PT J AU ANDERSON, IS BERK, NF RUSH, JJ UDOVIC, TJ BARNES, RG MAGERL, A RICHTER, D AF ANDERSON, IS BERK, NF RUSH, JJ UDOVIC, TJ BARNES, RG MAGERL, A RICHTER, D TI RAPID LOW-TEMPERATURE HOPPING OF HYDROGEN IN A PURE METAL - THE SCHX SYSTEM - REPLY SO PHYSICAL REVIEW LETTERS LA English DT Letter C1 NATL INST STAND & TECHNOL,MAT SCI & ENGN LAB,GAITHERSBURG,MD 20899. IOWA STATE UNIV SCI & TECHNOL,DEPT PHYS,AMES,IA 50011. IOWA STATE UNIV SCI & TECHNOL,AMES LAB,AMES,IA 50011. INST MAX VON LAUE PAUL LANGEVIN,F-38042 GRENOBLE,FRANCE. INST FESTKORPERFORSCH KERNFORSCHUNGSANLAGE,W-6170 JULICH,GERMANY. RP ANDERSON, IS (reprint author), PAUL SCHERRER INST,CH-5232 VILLIGEN,SWITZERLAND. RI Richter, Dieter/H-3701-2013; Magerl, Andreas/E-1797-2013 OI Richter, Dieter/0000-0003-0719-8470; NR 1 TC 0 Z9 0 U1 0 U2 1 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 0031-9007 J9 PHYS REV LETT JI Phys. Rev. Lett. PD MAY 6 PY 1991 VL 66 IS 18 BP 2415 EP 2415 DI 10.1103/PhysRevLett.66.2415 PG 1 WC Physics, Multidisciplinary SC Physics GA FK183 UT WOS:A1991FK18300037 ER PT J AU TALUKDAR, R MELLOUKI, A GIERCZAK, T BURKHOLDER, JB MCKEEN, SA RAVISHANKARA, AR AF TALUKDAR, R MELLOUKI, A GIERCZAK, T BURKHOLDER, JB MCKEEN, SA RAVISHANKARA, AR TI ATMOSPHERIC LIFETIME OF CHF2BR, A PROPOSED SUBSTITUTE FOR HALONS SO SCIENCE LA English DT Article AB The rate coefficients, k1, for the reaction of OH with CHF2Br have been measured using pulsed photolysis and discharge flow techniques at temperatures (T) between 233 and 432 K to be k1 = (7.4 +/- 1.6) x 10(-13) exp[-(1300 +/- 100)/T] cubic centimeters per molecule per second. The ultraviolet absorption cross sections, sigma, of this molecule between 190 and 280 nanometers were measured at 296 K. The k1 and sigma-values were used in a one-dimensional model to obtain an atmospheric lifetime of approximately 7 years for CHF2Br. This lifetime is shorter by approximately factors of 10 and 2 than those for CF3Br and CF2ClBr, respectively. The ozone depletion potentials of the three compounds will reflect these lifetimes. C1 NOAA,AERON LAB,R-E-AL2,325 BROADWAY,BOULDER,CO 80303. UNIV COLORADO,NOAA,COOPERAT INST RES ENVIRONM SCI,BOULDER,CO 80309. UNIV COLORADO,DEPT CHEM & BIOCHEM,BOULDER,CO 80309. RI TALUKDAR, RANAJIT/G-4530-2013; Burkholder, James/H-4914-2013; McKeen, Stuart/H-9516-2013; Ravishankara, Akkihebbal/A-2914-2011; Mellouki, Abdelwahid/H-5219-2011 OI TALUKDAR, RANAJIT/0000-0001-6017-8431; Mellouki, Abdelwahid/0000-0002-6594-5262 NR 12 TC 17 Z9 17 U1 0 U2 2 PU AMER ASSOC ADVANCEMENT SCIENCE PI WASHINGTON PA 1200 NEW YORK AVE, NW, WASHINGTON, DC 20005 SN 0036-8075 J9 SCIENCE JI Science PD MAY 3 PY 1991 VL 252 IS 5006 BP 693 EP 695 DI 10.1126/science.252.5006.693 PG 3 WC Multidisciplinary Sciences SC Science & Technology - Other Topics GA FK185 UT WOS:A1991FK18500044 PM 17746668 ER PT J AU POLAK, ML GILLES, MK HO, J LINEBERGER, WC AF POLAK, ML GILLES, MK HO, J LINEBERGER, WC TI PHOTOELECTRON-SPECTROSCOPY OF CUO- SO JOURNAL OF PHYSICAL CHEMISTRY LA English DT Letter ID ELECTRIC-DIPOLE MOMENT; METAL CLUSTER ANIONS; GAS-PHASE CUO; LABORATORY MEASUREMENT; X2II STATE; PHOTODETACHMENT; AFFINITY; FEO AB Laser photoelectron spectroscopy has been used to study the CuO- anion and neutral CuO molecule. Analysis of the photoelectron spectrum yields an electron affinity of 1.777 (6) eV for CuO. Equilibrium bond lengths and vibrational frequencies are obtained from a Franck-Condon analysis of the relative intensities of the observed transitions, yielding a CuO- bond length of 1.670 (10) angstrom and a CuO- vibrational frequency of 739 (25) cm-1. The analysis also yields a bond length (1.704 (10) angstrom) and a vibrational frequency (682 (25) cm-1) for the Y2-SIGMA+ excited state of CuO. C1 UNIV COLORADO,NATL INST STAND & TECHNOL,JOINT INST LAB ASTROPHYS,BOULDER,CO 80302. UNIV COLORADO,DEPT CHEM & BIOCHEM,BOULDER,CO 80309. NR 25 TC 42 Z9 42 U1 0 U2 8 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 SN 0022-3654 J9 J PHYS CHEM-US JI J. Phys. Chem. PD MAY 2 PY 1991 VL 95 IS 9 BP 3460 EP 3463 DI 10.1021/j100162a005 PG 4 WC Chemistry, Physical SC Chemistry GA FK322 UT WOS:A1991FK32200005 ER PT J AU MEYER, CW MORRISON, G AF MEYER, CW MORRISON, G TI DIPOLE-MOMENTS OF 7 PARTIALLY HALOGENATED ETHANE REFRIGERANTS SO JOURNAL OF PHYSICAL CHEMISTRY LA English DT Article ID 1,1,1,2-TETRAFLUOROETHANE; LIQUID; VAPOR AB Dielectric constant measurements have been performed on seven partially halogenated ethanes, currently being considered as alternative refrigerants, in the gaseous state over the range 305-415 K in order to determine their dipole moments. Argon was also studied to test the apparatus. Five of the refrigerants have temperature-independent moments: R125 (CF3CHF2), mu = 1.563 +/- 0.005 D; R134a (CF3CH2F), mu = 2.058 +/- 0.010 D; R143a (CF3CH3), mu = 2.340 +/- 0.010 D; R152a (CHF2CH3), mu = 2.262 +/- 0.008 D; and R124 (CF3CHClF), mu = 1.469 +/- 0.012 D. Two refrigerants have conformer-dependent moments, making their time-averaged moments temperature dependent: R134 (CHF2CHF2), with a moment ranging from 0.991 +/- 0.004 D at 309 K to 1.250 +/- 0.004 D at 413 K; and R143 (CHF2CH2F), where the moment ranges from 1.680 +/- 0.001 D at 309 K to 1.745 +/- 0.001 D at 410 K. Accurate estimation of a molecule's temperature-dependent dipole moment requires an independent determination of its polarizability; this determination has been made from index of refraction measurements. Where possible, the present results are compared with earlier determinations of dipole moments. In all but one instance, the agreement is good. RP MEYER, CW (reprint author), NATL INST STAND & TECHNOL,DIV THERMOPHYS,GAITHERSBURG,MD 20899, USA. NR 26 TC 59 Z9 59 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 MAY 2 PY 1991 VL 95 IS 9 BP 3860 EP 3866 DI 10.1021/j100162a077 PG 7 WC Chemistry, Physical SC Chemistry GA FK322 UT WOS:A1991FK32200077 ER PT J AU SUNDA, WG SWIFT, DG HUNTSMAN, SA AF SUNDA, WG SWIFT, DG HUNTSMAN, SA TI LOW IRON REQUIREMENT FOR GROWTH IN OCEANIC PHYTOPLANKTON SO NATURE LA English DT Article ID DIATOM THALASSIOSIRA-WEISSFLOGII; MARINE-PHYTOPLANKTON; CELLULAR MANGANESE; ZINC; ESTUARINE; CADMIUM; COPPER AB DESPITE the controversy on the importance of iron in limiting phytoplankton growth and affecting air-sea exchange of CO2 in the ocean 1-4, there is very little information on cellular iron requirements for growth. The few data available 5,6 come from species isolated from coastal sea water where dissolved Fe levels are 10-1,000 times higher than those (less-than-or-equal-to 0.1 nM) in the open ocean 1,7. Species from oceanic waters require much lower external Fe concentrations for growth than do comparable coastal species 8. Here we report that an oceanic diatom was able to grow at a near maximum specific rate of about 1.0 per day at a cellular Fe:C ratio of 2-mu-mol:mol, about 25% of the amount needed for the same rate in a related estuarine species, and 2-20% of values previously used to estimate algal Fe requirements in sea water 1,2. These results have important implications concerning iron limitation of primary productivity in the ocean and cell biology of iron in oceanic algae. C1 NOAA,NATL MARINE FISHERIES SERV,SE FISHERIES CTR,BEAUFORT LAB,BEAUFORT,NC 28516. UNIV RHODE ISL,GRAD SCH OCEANOG,NARRAGANSETT,RI 02882. NR 21 TC 209 Z9 219 U1 0 U2 34 PU MACMILLAN MAGAZINES LTD PI LONDON PA 4 LITTLE ESSEX STREET, LONDON, ENGLAND WC2R 3LF SN 0028-0836 J9 NATURE JI Nature PD MAY 2 PY 1991 VL 351 IS 6321 BP 55 EP 57 DI 10.1038/351055a0 PG 3 WC Multidisciplinary Sciences SC Science & Technology - Other Topics GA FK193 UT WOS:A1991FK19300057 ER PT J AU SJOLIN, L PRINCE, E SVENSSON, LA GILLILAND, GL AF SJOLIN, L PRINCE, E SVENSSON, LA GILLILAND, GL TI ABINITIO PHASE DETERMINATION FOR X-RAY-DIFFRACTION DATA FROM CRYSTALS OF A NATIVE PROTEIN SO ACTA CRYSTALLOGRAPHICA SECTION A LA English DT Article ID MAXIMUM-ENTROPY; ELECTRON-DENSITY; COMBINED MAXIMIZATION; STATISTICAL GEOMETRY; MULTISOLUTION METHOD; LIKELIHOOD; CONSISTENT AB An efficient algorithm for the determination of an everywhere positive electron-density distribution that agrees with observed structure amplitudes has been used to determine the phases of X-ray diffraction data from recombinant bovine chymosin, a protein with 323 amino-acid residues in the molecular chain whose structure was recently determined using molecular replacement methods. A systematic procedure for testing the signs of centric reflections, using the total entropy of the map as a figure of merit, was used to produce a low-resolution map. The phases of acentric and additional centric reflections were then chosen by adding them to the map with various possible phases and computing the total entropy of the resulting map. Of 159 centric reflections whose phases were chosen by this procedure, 141 had the same phase as in the refined structure. The median absolute phase difference for 1811 acentric reflections was 32-degrees. A map produced from these 1970 reflections, out of 12 346 reflections in the data set, showed a remarkable agreement with the refined structure. This molecule is many times larger than any whose structures have previously been determined without the use of isomorphous replacement, molecular replacement or anomalous dispersion, and the map demonstrates the potential of maximum-entropy methods in macro-molecular structure determination. C1 GOTHENBURG UNIV,S-41296 GOTHENBURG,SWEDEN. NATL INST STANDARDS & TECHNOL,MAT SCI & ENGN LAB,GAITHERSBURG,MD 20899. NATL INST STANDARDS & TECHNOL,CTR ADV RES BIOTECHNOL,ROCKVILLE,MD 20850. RP SJOLIN, L (reprint author), CHALMERS UNIV TECHNOL,INST INORGAN CHEM,S-41296 GOTHENBURG,SWEDEN. RI Sjolin, Lennart/B-2619-2010 NR 28 TC 20 Z9 20 U1 0 U2 1 PU MUNKSGAARD INT PUBL LTD PI COPENHAGEN PA 35 NORRE SOGADE, PO BOX 2148, DK-1016 COPENHAGEN, DENMARK SN 0108-7673 J9 ACTA CRYSTALLOGR A JI Acta Crystallogr. Sect. A PD MAY 1 PY 1991 VL 47 BP 216 EP 223 DI 10.1107/S0108767390012077 PN 3 PG 8 WC Chemistry, Multidisciplinary; Crystallography SC Chemistry; Crystallography GA FM628 UT WOS:A1991FM62800012 PM 1854440 ER PT J AU SPAL, RD AF SPAL, RD TI THE REFLECTED AND REFRACTED FUNDAMENTAL MODES OF DYNAMIC X-RAY-DIFFRACTION SO ACTA CRYSTALLOGRAPHICA SECTION A LA English DT Article AB An energy-conservation relation is derived between the power absorption, energy flux and absorption coefficient of an arbitrary fundamental mode in the n-beam dynamical theory of X-ray diffraction. From this relation, it is proven that the 4n fundamental modes selected by arbitrary incidence conditions are evently divided into two types. The types are distinguished by the sign of their absorption coefficient and by the sign of their energy flux through a plane of constant absorption. In a bounded crystal, they represent reflected and refracted beams. It is noteworthy that these results apply for arbitrary n, even though the solution of the n-beam equations only satisfies Maxwell's equations in the limit of infinite n. In this limit, the energy-conservation relation is equivalent to Poynting's theorem. C1 NATL INST STANDARDS & TECHNOL,DIV CERAM,GAITHERSBURG,MD 20899. NR 10 TC 0 Z9 0 U1 0 U2 0 PU MUNKSGAARD INT PUBL LTD PI COPENHAGEN PA 35 NORRE SOGADE, PO BOX 2148, DK-1016 COPENHAGEN, DENMARK SN 0108-7673 J9 ACTA CRYSTALLOGR A JI Acta Crystallogr. Sect. A PD MAY 1 PY 1991 VL 47 BP 223 EP 226 DI 10.1107/S0108767390012673 PN 3 PG 4 WC Chemistry, Multidisciplinary; Crystallography SC Chemistry; Crystallography GA FM628 UT WOS:A1991FM62800013 ER PT J AU KRUEGER, S LONG, GG PAGE, RA AF KRUEGER, S LONG, GG PAGE, RA TI CHARACTERIZATION OF THE DENSIFICATION OF ALUMINA BY MULTIPLE SMALL-ANGLE NEUTRON-SCATTERING SO ACTA CRYSTALLOGRAPHICA SECTION A LA English DT Article AB Multiple small-angle neutron scattering was used to follow the evolution of the pore-size distribution in alpha-Al2O3 through the intermediate and final stages of sintering. This new technique enables the study of microstructure in the 0.08-10 mu-m size regime, which is the size range of importance for many materials systems, without needing to increase the resolution of currently available small-angle scattering instruments. The microstructure evolution results indicate a nearly constant effective pore radius for the alumina throughout the intermediate sintering stage, ranging from 0.19-mu-m at 54% of theoretical density to 0.17-mu-m at 79% dense. As the alumina densifies further, there is a transition region after which the effective pore radius grows rapidly to greater-than-or-equal-to 0.6-mu-m at 97.5% dense. C1 SW RES INST,SAN ANTONIO,TX 78228. RP KRUEGER, S (reprint author), NATL INST STANDARDS & TECHNOL,GAITHERSBURG,MD 20899, USA. NR 21 TC 16 Z9 16 U1 0 U2 3 PU MUNKSGAARD INT PUBL LTD PI COPENHAGEN PA 35 NORRE SOGADE, PO BOX 2148, DK-1016 COPENHAGEN, DENMARK SN 0108-7673 J9 ACTA CRYSTALLOGR A JI Acta Crystallogr. Sect. A PD MAY 1 PY 1991 VL 47 BP 282 EP 290 DI 10.1107/S0108767391000570 PN 3 PG 9 WC Chemistry, Multidisciplinary; Crystallography SC Chemistry; Crystallography GA FM628 UT WOS:A1991FM62800022 ER PT J AU BASU, B SEKHAR, JA SCHAEFER, RJ MEHRABIAN, R AF BASU, B SEKHAR, JA SCHAEFER, RJ MEHRABIAN, R TI ANALYSIS OF THE STEADY-STATE MOLTEN POOL OBTAINED BY HEATING A SUBSTRATE WITH AN ELECTRON-BEAM SO ACTA METALLURGICA ET MATERIALIA LA English DT Article ID CONVECTION; CAVITY; FLOW AB Surface melting and solidification with high powered beams can be used for enhancing surface properties. The dimensions of the molten zone define the extent of the modified properties and are critical parameters which must be predicted during process design. The flow field in the molten pool has been reported to be one of the key factors which controls the dimensions of the surface layer. However, the calculation of this is only possible through complex numerical schemes and there is a need to look for simple analytical expressions which may be adequate. One approach for this search involves the precise determination of the steady state stationary profiles and then developing a method for extending these values to include the effect of beam motion for predicting the pool dimensions during processing. In this paper, a study of the flow field and its effect on the depth and width of the steady state pool is presented, based on numerical and analytical methods. To validate the predictions, an experimental study is carried out using surface melting of Al-4.5 wt%Cu alloy with an electron beam. The pool shapes are presented through optical micrographs and the depth and width of the pool is measured from these micrographs. The experiments are then simulated using a numerical model which includes fluid flow. The flow field is analyzed using streamline plots and the predicted pool shapes are compared with the micrographs. Further, the results are compared to an analytical method based on pure conduction and the pool depth and width are predicted when the liquid thermal conductivity is modified. The numerical and analytical predictions of the pool depth and width are found to be in good agreement with the experimental measurements (obtained from steady state stationary pools and from dimensions inferred on extrapolating moving beam measurements to zero velocity). The reasons for the success of the analytical model is discussed with reference to the two-dimensional flow fields and vortices predicted by the numerical model. C1 UNIV CINCINNATI, DEPT MAT SCI & ENGN, CINCINNATI, OH 45221 USA. NATL INST STANDARDS & TECHNOL, GAITHERSBURG, MD USA. CARNEGIE MELLON UNIV, PITTSBURGH, PA 15213 USA. RP BASU, B (reprint author), TATA RES DESIGN DEV CTR, POONA 411001, INDIA. NR 21 TC 4 Z9 4 U1 1 U2 2 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLAND SN 0956-7151 J9 ACTA METALL MATER JI Acta Metall. Mater. PD MAY PY 1991 VL 39 IS 5 BP 725 EP 733 DI 10.1016/0956-7151(91)90273-4 PG 9 WC Materials Science, Multidisciplinary; Metallurgy & Metallurgical Engineering SC Materials Science; Metallurgy & Metallurgical Engineering GA FH777 UT WOS:A1991FH77700001 ER PT J AU WADLEY, HNG SCHAEFER, RJ KAHN, AH ASHBY, MF CLOUGH, RB GEFFEN, Y WLASSICH, JJ AF WADLEY, HNG SCHAEFER, RJ KAHN, AH ASHBY, MF CLOUGH, RB GEFFEN, Y WLASSICH, JJ TI SENSING AND MODELING OF THE HOT ISOSTATIC PRESSING OF COPPER PRESSING SO ACTA METALLURGICA ET MATERIALIA LA English DT Article ID SINTERING DIAGRAMS AB A detailed experimental evaluation of mathematical models for densification during hot isostatic pressing (HIP) has been conducted using high purity copper powder as a model system. Using a new eddy current sensor, the density of cylindrical compacts has been measured in situ and compared with model predictions for the HIP process. Pressure shielding by the can has been found to influence the densification, and a simple plastic analysis of a thin-walled pressure vessel was used to account for its effects in the models. The existence of a low temperature creep mechanism during consolidation has been found and a formulation to account for its contribution to densification has been developed and implemented in the models. Other effects, believed to be associated with transient creep and the temperature dependence of power law creep parameters, have also been observed in the experiments and suggest the need for further model refinement. C1 NATL INST STAND & TECHNOL, DIV MET, GAITHERSBURG, MD USA. UNIV CAMBRIDGE, DEPT ENGN, CAMBRIDGE CB2 1PZ, ENGLAND. NUCL RES CTR NEGEV, IL-84190 BEER SHEVA, ISRAEL. BDM INT INC, ROSSLYN, VA USA. RP WADLEY, HNG (reprint author), UNIV VIRGINIA, DEPT MAT & SCI, CHARLOTTESVILLE, VA 22903 USA. NR 12 TC 31 Z9 31 U1 2 U2 11 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 MAY PY 1991 VL 39 IS 5 BP 979 EP 986 DI 10.1016/0956-7151(91)90298-F PG 8 WC Materials Science, Multidisciplinary; Metallurgy & Metallurgical Engineering SC Materials Science; Metallurgy & Metallurgical Engineering GA FH777 UT WOS:A1991FH77700026 ER PT J AU TURNER, S STEEL, EB AF TURNER, S STEEL, EB TI ACCURACY OF TRANSMISSION ELECTRON-MICROSCOPY ANALYSIS OF ASBESTOS ON FILTERS - INTERLABORATORY STUDY SO ANALYTICAL CHEMISTRY LA English DT Article ID AMBIENT ENVIRONMENTS AB An interlaboratory study was conducted to determine the accuracy of determinations of the asbestos concentration on filters by use of transmission electron microscopy. Replica sections were prepared from a single polycarbonate filter that had chrysotile and several types of non-asbestos particles deposited on its surface. Twenty-seven analysts from 15 laboratories counted a minimum of 3 grid squares and recorded the physical characteristics of the particles and the methods used for identification of the particles. One of the grid squares counted by each analyst was reanalyzed at the National Institute of Standards and Technology (NIST) by using verified counting methods. The mean value of TP/TNS (true positives/total number of structures) obtained by the laboratories on the verified grid squares is 0.67, and the mean value for FP/TNS (false positives/total number of structures) is 0.04. More than 40% of the fibers shorter than 1-mu-m were missed, whereas less than 20% of the fibers longer than 1 mu-m were missed by the analysts. Incorrect translation of the electron microscope stage is a likely cause of many false negative values. Other possible reasons for false negatives and false positives are discussed. RP TURNER, S (reprint author), NATL INST STAND & TECHNOL,CTR ANALYT CHEM,GAITHERSBURG,MD 20899, USA. NR 7 TC 6 Z9 6 U1 0 U2 3 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 SN 0003-2700 J9 ANAL CHEM JI Anal. Chem. PD MAY 1 PY 1991 VL 63 IS 9 BP 868 EP 872 DI 10.1021/ac00009a005 PG 5 WC Chemistry, Analytical SC Chemistry GA FJ318 UT WOS:A1991FJ31800007 ER PT J AU COLLIER, TK VARANASI, U AF COLLIER, TK VARANASI, U TI HEPATIC ACTIVITIES OF XENOBIOTIC METABOLIZING ENZYMES AND BILIARY LEVELS OF XENOBIOTICS IN ENGLISH SOLE (PAROPHRYS-VETULUS) EXPOSED TO ENVIRONMENTAL CONTAMINANTS SO ARCHIVES OF ENVIRONMENTAL CONTAMINATION AND TOXICOLOGY LA English DT Article ID POLYCYCLIC AROMATIC-HYDROCARBONS; TROUT SALMO-GAIRDNERI; RAINBOW-TROUT; PUGET-SOUND; S-TRANSFERASE; BILE; FISH; BENZO(A)PYRENE; BENZOPYRENE; HYDROXYLASE AB English sole (Parophrys vetulus) are susceptible to the development of hepatic disease, including neoplasia, as a result of environmental exposure to polycyclic aromatic hydrocarbons (PAHs). The metabolism of PAHs, believed to be an essential factor in the development of neoplasia, has received considerable study in English sole, except that xenobiotic metabolizing enzymes (XMEs) have not been well-studied in this species. In the present work, the activities of hepatic aryl hydrocarbon hydroxylase (AHH), glutathione-S-transferase (GST), and epoxide hydrolase (EH) were measured in English sole exposed to several organic xenobiotics. These studies included an examination of the effects of captivity, the short-term responses of hepatic XME activities to several xenobiotic compounds, and detailed studies of the time- and dose-responses of hepatic XME activities to both a representative carcinogenic PAH (benzo[a]pyrene) and to a complex mixture of contaminants extracted from a sediment collected from a polluted area of Puget Sound, WA. Additionally, during the captivity and time- and dose-response studies, the levels of fluorescent aromatic compounds (FACs) were measured in the bile of the fish, both to provide an estimation of contaminant exposure and to evaluate the time- and dose-responses of this measure. The results of the captivity studies showed that the levels of FACs in bile were most affected by captivity, primarily as a result of changes in feeding status. The results of the exposure studies showed that xenobiotic metabolism, as reflected in hepatic activities of XMEs and levels of FACs in the bile, is altered by exposure to environmental contaminants. Whereas hepatic AHH activity could be rapidly and substantially increased by such exposure, activities of GST and EH were not affected, even up to 42 days after exposure. Moreover, because fish were exposed to a wide range of doses of chemicals or mixtures of chemicals which are known to be present in contaminated estuaries, and the responses of the hepatic AHH system and the levels of FACs in bile were measured at several time periods after exposure, the results provided substantial validation for the use of these two measures as bioindicators of exposure to environmental contamination in benthic fish. RP COLLIER, TK (reprint author), NOAA,NATL MARINE FISHERIES SERV,NW FISHERIES CTR,DIV ENVIRONM CONSERVAT,2725 MONTLAKE BLVD E,SEATTLE,WA 98112, USA. NR 56 TC 203 Z9 216 U1 2 U2 19 PU SPRINGER VERLAG PI NEW YORK PA 175 FIFTH AVE, NEW YORK, NY 10010 SN 0090-4341 J9 ARCH ENVIRON CON TOX JI Arch. Environ. Contam. Toxicol. PD MAY PY 1991 VL 20 IS 4 BP 462 EP 473 PG 12 WC Environmental Sciences; Toxicology SC Environmental Sciences & Ecology; Toxicology GA FH939 UT WOS:A1991FH93900003 PM 2069420 ER PT J AU HUGHES, JB HEBERT, AT AF HUGHES, JB HEBERT, AT TI ERYTHROCYTE MICRONUCLEI IN WINTER FLOUNDER (PSEUDOPLEURONECTES-AMERICANUS) - RESULTS OF FIELD SURVEYS DURING 1980-1988 FROM VIRGINIA TO NOVA-SCOTIA AND IN LONG-ISLAND-SOUND SO ARCHIVES OF ENVIRONMENTAL CONTAMINATION AND TOXICOLOGY LA English DT Article ID PERIPHERAL-BLOOD ERYTHROCYTES; ETHYL METHANESULFONATE; EASTERN MUDMINNOW; UMBRA-PYGMAEA; INDUCTION; BENZOPYRENE; ABNORMALITIES; ECOLOGY AB Erythrocyte micronuclei (MN) frequencies of 280 winter flounder (Pseudopleuronectes americanus) from Chesapeake Bay to the southern Scotian Shelf including Long Island Sound were measured. The MN data were combined with data previously reported for 224 flounder and the combined data sets were analyzed. Incidences of MN were elevated sixfold in flounder from the New York Bight Apex as compared to frequencies for fish from the inshore Gulf of Maine and Block Island Sound, and twice those found in Georges Bank and Long Island Sound flounder. Inshore New Jersey fish had higher MN frequencies than those from inshore Gulf of Maine and Block Island Sound. The occurrence of MN in flounder from inshore Virginia was higher than in flounder from inshore Gulf of Maine and Block Island Sound. The large subset of stations from Long Island Sound indicated higher frequencies of MN in flounder from Hempstead and Shoreham as compared to most other sites in the Sound. There was no significant difference in the frequency of MN between males and females, but males had significantly more MN than sexually immature flounder. Flounder over the entire sampling area had increased levels of MN during the fall months of the year. This is probably influenced by the maternal cycle of gonadal maturation. RP HUGHES, JB (reprint author), NOAA,NATL MARINE FISHERIES SERV,NW FISHERIES CTR,MILFORD LAB,MILFORD,CT 06460, USA. NR 28 TC 44 Z9 46 U1 0 U2 1 PU SPRINGER VERLAG PI NEW YORK PA 175 FIFTH AVE, NEW YORK, NY 10010 SN 0090-4341 J9 ARCH ENVIRON CON TOX JI Arch. Environ. Contam. Toxicol. PD MAY PY 1991 VL 20 IS 4 BP 474 EP 479 PG 6 WC Environmental Sciences; Toxicology SC Environmental Sciences & Ecology; Toxicology GA FH939 UT WOS:A1991FH93900004 PM 2069421 ER PT J AU RYBICKI, GB HUMMER, DG AF RYBICKI, GB HUMMER, DG TI AN ACCELERATED LAMBDA ITERATION METHOD FOR MULTILEVEL RADIATIVE-TRANSFER .1. NONOVERLAPPING LINES WITH BACKGROUND CONTINUUM SO ASTRONOMY & ASTROPHYSICS LA English DT Article DE RADIATIVE TRANSFER; NON-LTE; STELLAR ATMOSPHERES ID NEWTON-RAPHSON OPERATOR; EXPANDING ATMOSPHERES; COMOVING FRAME AB A method is presented for solving multilevel transfer problems with non-overlapping lines and with background continuum (but no active continuum transfer). This method is based on the use of an approximate lambda operator, which is either the diagonal or a finite band of the "true" numerical lambda operator. Linear, "preconditioned" equations of statistical equilibrium are derived, the coefficients of which are found efficiently using a new fast method for finding the diagonal elements (or a band) of the "true" numerical lambda operator. The preconditioned equations are used iteratively with the formal solution of the transfer equation, so that the entire iteration scheme involves solving only linear equations based on one previous iteration. Applications of the method are made to several multilevel problems, including a model problem of Avrett & Loeser (1987) and an eleven-level neutral helium atom. Convergence properties of the method are systematically investigated for these problems, using diagonal and tridiagonal approximate lambda operators, with and without the acceleration technique of Ng (1974), and the method has proved to be fast and reliable for line transfer problems of this type. An appendix gives an improved version of the Feautrier scheme that has much better numerical conditioning for small optical depths. C1 UNIV COLORADO, NATL INST STAND & TECHNOL, JOINT INST LAB ASTROPHYS, BOULDER, CO 80302 USA. RP RYBICKI, GB (reprint author), HARVARD SMITHSONIAN CTR ASTROPHYS, 60 GARDEN ST, CAMBRIDGE, MA 02138 USA. NR 34 TC 334 Z9 334 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 MAY PY 1991 VL 245 IS 1 BP 171 EP 181 PG 11 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA FM350 UT WOS:A1991FM35000022 ER PT J AU PAP, JM LONDON, J ROTTMAN, GJ AF PAP, JM LONDON, J ROTTMAN, GJ TI VARIABILITY OF SOLAR LYMAN-ALPHA AND TOTAL SOLAR IRRADIANCE SO ASTRONOMY & ASTROPHYSICS LA English DT Article DE UV RADIATION; ACTIVITY OF THE SUN; FACULAE; SUNSPOTS ID ULTRAVIOLET IRRADIANCE; ACTIVE REGION; RADIO FLUX; LUMINOSITY; EVOLUTION; CONSTANT; MODEL; LINE AB Variation of ultraviolet and total solar irradiance is investigated during the declining portion of solar cycle 21, through solar cycle minimum and into the rising portion of solar cycle 22. Both the Lyman alpha and total irradiance decrease during the declining phase of solar cycle 21 and increase with the growing new activity of solar cycle 22. The same changes are evident in a variety of solar activity indices, such as 10.7 cm radio flux, Ca-K plage index and projected sunspot areas. However, while the total irradiance, 10.7 cm radio flux, Ca-K plage index and projected sunspot areas each reach minimum levels in early 1985 with a flat background during the following two years, the Lyman alpha flux slowly decays to a brief minimum in mid-1986, around the time of magnetic solar minimum. C1 UNIV COLORADO, NOAA, COOPERAT INST RES ENVIRONM SCI, BOULDER, CO 80309 USA. UNIV COLORADO, DEPT ASTROPHYS PLANETARY & ATMOSPHER SCI, BOULDER, CO 80309 USA. UNIV COLORADO, ATMOSPHER & SPACE PHYS LAB, BOULDER, CO 80309 USA. NR 32 TC 13 Z9 13 U1 0 U2 0 PU EDP SCIENCES S A PI LES ULIS CEDEX A PA 17, AVE DU HOGGAR, PA COURTABOEUF, BP 112, F-91944 LES ULIS CEDEX A, FRANCE SN 0004-6361 J9 ASTRON ASTROPHYS JI Astron. Astrophys. PD MAY PY 1991 VL 245 IS 2 BP 648 EP 653 PG 6 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA FQ886 UT WOS:A1991FQ88600035 ER PT J AU LUO, D MCCRAY, R AF LUO, D MCCRAY, R TI SUPERNOVA REMNANT 1987A SO ASTROPHYSICAL JOURNAL LA English DT Article DE HYDRODYNAMICS; NEBULAE, INDIVIDUAL (SN-1987A); NEBULAE, SUPERNOVA REMNANTS; RADIATION MECHANISMS; SHOCK WAVES ID PROGENITOR; EVOLUTION; EMISSION; BUBBLES; GRAINS; PLASMA; GAS; HOT AB A dense circumstellar shell, with radius of about 0.5 lt-yr, surrounds SN 1987A. In less-than-or-equal-to 16 yr after outburst, the expanding debris of SN 1987A will strike this shell. When it does, the hot gas and relativistic electrons resulting from the forward and reverse shocks will radiate X-rays, infrared radiation, and nonthermal radio waves. The remnant of SN 1987A will then become one of the brightest X-ray and radio sources in the LMC. RP LUO, D (reprint author), UNIV COLORADO,NATL INST STAND & TECHNOL,JOINT INST LAB ASTROPHYS,BOULDER,CO 80302, USA. NR 23 TC 22 Z9 22 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 MAY 1 PY 1991 VL 372 IS 1 BP 194 EP 198 DI 10.1086/169964 PN 1 PG 5 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA FH367 UT WOS:A1991FH36700017 ER PT J AU MILLER, GC RICHARDS, WJ AF MILLER, GC RICHARDS, WJ TI REVISION OF THE WESTERN ATLANTIC AND EASTERN PACIFIC GENUS BELLATOR (PISCES, TRIGLIDAE) SO BULLETIN OF MARINE SCIENCE LA English DT Article AB The genus Bellator comprises seven species with four in the western Atlantic (brachychir, egretta, militaris, and ribeiroi) and three in the eastern tropical Pacific (gymnostethus, xenisma, and loxias). A key to their identification is provided along with synonymies, descriptions, type material, and illustrations. The genus Bellator is diagnosed, and preliminary information is provided on the genera of the family Triglidae. C1 NOAA,SE FISHERIES CTR,MIAMI,FL 33149. NR 70 TC 7 Z9 7 U1 2 U2 2 PU ROSENSTIEL SCH MAR ATMOS SCI PI MIAMI PA 4600 RICKENBACKER CAUSEWAY, MIAMI, FL 33149 SN 0007-4977 J9 B MAR SCI JI Bull. Mar. Sci. PD MAY PY 1991 VL 48 IS 3 BP 635 EP 656 PG 22 WC Marine & Freshwater Biology; Oceanography SC Marine & Freshwater Biology; Oceanography GA GC813 UT WOS:A1991GC81300004 ER PT J AU MILLER, GC RICHARDS, WJ AF MILLER, GC RICHARDS, WJ TI NOMENCLATURAL CHANGES IN THE GENUS PRIONOTUS (PISCES, TRIGLIDAE) SO BULLETIN OF MARINE SCIENCE LA English DT Note C1 NOAA,SE FISHERIES CTR,MIAMI,FL 33149. NR 10 TC 5 Z9 5 U1 0 U2 0 PU ROSENSTIEL SCH MAR ATMOS SCI PI MIAMI PA 4600 RICKENBACKER CAUSEWAY, MIAMI, FL 33149 SN 0007-4977 J9 B MAR SCI JI Bull. Mar. Sci. PD MAY PY 1991 VL 48 IS 3 BP 757 EP 762 PG 6 WC Marine & Freshwater Biology; Oceanography SC Marine & Freshwater Biology; Oceanography GA GC813 UT WOS:A1991GC81300014 ER PT J AU MISRA, DN AF MISRA, DN TI ADSORPTION AND ORIENTATION OF TETRACYCLINE ON HYDROXYAPATITE SO CALCIFIED TISSUE INTERNATIONAL LA English DT Article DE ADSORPTION; HYDROGEN BONDING; HYDROXYAPATITE; ORIENTATION; TETRACYCLINE ID DENTAL POLYMER COMPOSITES; COUPLING AGENTS; TEETH; ACID AB Adsorption of tetracycline from separate solutions of ethanol, p-dioxane, and chloroform onto synthetic hydroxyapatite (containing about 1.5 monolayer of physisorbed water) was studied in order to understand its interaction with bone and teeth. The adsorption isotherms of tetracycline are reversible and Langmuirian from ethanol and p-dioxane and are almost identical. The isotherm is irreversible from chloroform, and a constant amount of adsorbate is removed from the solutions above a certain concentration. The irreversibly adsorbed compound is completely desorbed by prolonged repeated washing with ethanol. An analysis of the reversible isotherms showed that at maximum coverage the ring or polycyclic structure of the molecule stands perpendicular to the surface with appropriate hydroxyl groups and keto-oxygens hydrogen bonded to the surface. However, the adsorption from chloroform is irreversible and at maximum adsorption is about one and half times larger than that from either ethanol or p-dioxane. The process of adsorption does not affect the chemical integrity of tetracycline. RP MISRA, DN (reprint author), NATL INST STAND & TECHNOL,AMER DENT ASSOC HLTH FDN,PAFFENBARGER RES CTR,GAITHERSBURG,MD 20899, USA. NR 18 TC 21 Z9 24 U1 0 U2 4 PU SPRINGER VERLAG PI NEW YORK PA 175 FIFTH AVE, NEW YORK, NY 10010 SN 0171-967X J9 CALCIFIED TISSUE INT JI Calcif. Tissue Int. PD MAY PY 1991 VL 48 IS 5 BP 362 EP 367 DI 10.1007/BF02556156 PG 6 WC Endocrinology & Metabolism SC Endocrinology & Metabolism GA FF530 UT WOS:A1991FF53000010 PM 1647263 ER PT J AU BERMINGHAM, E FORBES, SH FRIEDLAND, K PLA, C AF BERMINGHAM, E FORBES, SH FRIEDLAND, K PLA, C TI DISCRIMINATION BETWEEN ATLANTIC SALMON (SALMO-SALAR) OF NORTH-AMERICAN AND EUROPEAN ORIGIN USING RESTRICTION ANALYSES OF MITOCHONDRIAL-DNA SO CANADIAN JOURNAL OF FISHERIES AND AQUATIC SCIENCES LA English DT Article ID DIFFERENTIATION; IDENTIFICATION AB Twenty restriction endonucleases were used to study mitochondrial DNA (mtDNA) polymorphism in 11 hatchery strains of Atlantic salmon (Salmo salar) representing geographically separated populations in Europe and North America. The North American salmon mtDNAs studied were readily distinguished, by a minimum of seven restriction site differences, from fish of European origin. These results suggested that restriction analyses of mtDNA might provide a useful method for determining the proportions of European and North American Atlantic salmon caught in the West Greenland fishery. To test this proposition, we analyzed 328 salmon caught in the 1987 West Greenland fishery including 68 fish with coded wire or Carlin tags which provided the geographic source of the tagged salmon. We correctly identified the continent of origin for 67 of the 68 physically tagged salmon using two informative restriction endonucleases. This study provides a clear indication of the usefulness of mtDNA for discriminating between European and North American Atlantic salmon caught in the West Greenland fishery and for mixed-fishery analysis in general. C1 NATL MARINE FISHERIES SERV,CZES GENET,SEATTLE,WA 98112. UNIV MONTANA,DEPT ZOOL,MISSOULA,MT 59812. NATL MARINE FISHERIES SERV,NE FISHERIES CTR,WOODS HOLE,MA 02543. COLL UNIV GIRONA,DEPT BIOL,E-17071 GIRONA,SPAIN. RI Pla, Carles/L-5765-2014 OI Pla, Carles/0000-0002-3749-4740 NR 32 TC 66 Z9 69 U1 1 U2 2 PU NATL RESEARCH COUNCIL CANADA PI OTTAWA PA RESEARCH JOURNALS, MONTREAL RD, OTTAWA ON K1A 0R6, CANADA SN 0706-652X J9 CAN J FISH AQUAT SCI JI Can. J. Fish. Aquat. Sci. PD MAY PY 1991 VL 48 IS 5 BP 884 EP 893 DI 10.1139/f91-105 PG 10 WC Fisheries; Marine & Freshwater Biology SC Fisheries; Marine & Freshwater Biology GA FP953 UT WOS:A1991FP95300018 ER PT J AU HINDAR, K RYMAN, N UTTER, F AF HINDAR, K RYMAN, N UTTER, F TI GENETIC-EFFECTS OF CULTURED FISH ON NATURAL FISH POPULATIONS SO CANADIAN JOURNAL OF FISHERIES AND AQUATIC SCIENCES LA English DT Article ID ADULT ATLANTIC SALMON; WILD STEELHEAD TROUT; ONCORHYNCHUS-TSHAWYTSCHA; CHINOOK SALMON; RAINBOW-TROUT; BROWN TROUT; GYRODACTYLUS-SALARIS; REPRODUCTIVE SUCCESS; COHO SALMON; HATCHERY AB This paper addresses the genetic consequences of aquaculture on natural fish populations. The study is motivated by rapidly increasing numbers of intentionally and accidentally released fish and is based on empirical observations reported in the literature. A wide variety of outcomes, ranging from no detectable effect to complete introgression or displacement, has been observed following releases of cultured fish into natural settings. Where genetic effects on performance traits have been documented, they always appear to be negative in comparison with the unaffected native populations. These findings are consistent with theoretical considerations of the implications of elevated levels of gene flow between cultured and locally adapted natural populations; they raise concerns over the genetic future of many natural populations in the light of increasing numbers of released fish. Strategies for the genetic protection of native populations from the effects of aquaculture are outlined including more secure containment, the use of sterilized fish, and modifying the points of rearing and release. We recommend strong restrictions on gene flow from cultured to wild populations and effective monitoring of such gene flow. C1 UNIV STOCKHOLM, DEPT GENET, S-10691 STOCKHOLM, SWEDEN. NATL MARINE FISHERIES SERV, NW FISHERIES CTR, SEATTLE, WA 98112 USA. RP HINDAR, K (reprint author), NORWEGIAN INST NAT RES, TUNGASLETTA 2, N-7004 TRONDHEIM, NORWAY. NR 97 TC 431 Z9 447 U1 10 U2 78 PU CANADIAN SCIENCE PUBLISHING, NRC RESEARCH PRESS PI OTTAWA PA 65 AURIGA DR, SUITE 203, OTTAWA, ON K2E 7W6, CANADA SN 0706-652X EI 1205-7533 J9 CAN J FISH AQUAT SCI JI Can. J. Fish. Aquat. Sci. PD MAY PY 1991 VL 48 IS 5 BP 945 EP 957 DI 10.1139/f91-111 PG 13 WC Fisheries; Marine & Freshwater Biology SC Fisheries; Marine & Freshwater Biology GA FP953 UT WOS:A1991FP95300024 ER PT J AU APTE, VB BILGER, RW GREEN, AR QUINTIERE, JG AF APTE, VB BILGER, RW GREEN, AR QUINTIERE, JG TI WIND-AIDED TURBULENT FLAME SPREAD AND BURNING OVER LARGE-SCALE HORIZONTAL PMMA SURFACES SO COMBUSTION AND FLAME LA English DT Article C1 NEW S WALES DEPT IND RELAT & EMPLOYMENT,LONDONDERRY OCCUPAT SAFETY CTR,LONDONDERRY,NSW 2753,AUSTRALIA. US DEPT COMMERCE,NATL INST STAND & TECHNOL,CTR FIRE RES,GAITHERSBURG,MD 20899. RP APTE, VB (reprint author), UNIV SYDNEY,DEPT MECH ENGN,SYDNEY,NSW 2006,AUSTRALIA. NR 18 TC 17 Z9 17 U1 0 U2 2 PU ELSEVIER SCIENCE INC PI NEW YORK PA 655 AVENUE OF THE AMERICAS, NEW YORK, NY 10010 SN 0010-2180 J9 COMBUST FLAME JI Combust. Flame PD MAY PY 1991 VL 85 IS 1-2 BP 169 EP 184 DI 10.1016/0010-2180(91)90185-E PG 16 WC Thermodynamics; Energy & Fuels; Engineering, Multidisciplinary; Engineering, Chemical; Engineering, Mechanical SC Thermodynamics; Energy & Fuels; Engineering GA FN965 UT WOS:A1991FN96500013 ER PT J AU PAYNE, JR HACHMEISTER, LE MCNABB, GD SHARPE, HE SMITH, GS MANEN, CA AF PAYNE, JR HACHMEISTER, LE MCNABB, GD SHARPE, HE SMITH, GS MANEN, CA TI BRINE-INDUCED ADVECTION OF DISSOLVED AROMATIC-HYDROCARBONS TO ARCTIC BOTTOM WATERS SO ENVIRONMENTAL SCIENCE & TECHNOLOGY LA English DT Article ID DISTILLED WATER; GREASE ICE; SEA; SOLUBILITY; PETROLEUM; SEAWATER; ALASKA; MODEL; LAYER; OIL AB Extruded brine, generated during sea ice formation in nearshore arctic waters, will sink to the bottom and can form a stable bottom boundary layer. This layer can persist for periods of up to 4-6 months. Limited quantities of dissolved aromatic hydrocarbons resulting from a spill of crude oil or refined petroleum distillate products during periods of ice growth can be transported as conservative components to the benthos with sinking brine. Once incorporated into the stable bottom boundary layer, these aromatic components are no longer subject to loss by evaporative processes, and they only can be diluted by ultimately mixing with uncontaminated water masses, a process that proceeds slowly throughout the ice-covered period. This mechanism for the transport of dissolved hydrocarbons has been demonstrated through laboratory test-tank simulations and a chemical/physical oceanographic field program conducted in the Chukchi Sea near Pt. Franklin, AK (March 1985). The results are pertinent to shallow nearshore oil and gas exploration, development, production, and transportation activities in high-latitude marine systems. C1 EBASCO ENVIRONM,BELLEVUE,WA 98004. SOUND ENVIRONM SERV INC,ANCHORAGE,AK 99503. SEATTLE EXECUT DEPT,SEATTLE,WA 98104. FLINT ENVIRONM,SAN DIEGO,CA 92126. NOAA,NATL OCEAN SERV,ROCKVILLE,MD 20852. RP PAYNE, JR (reprint author), SCI APPLICAT INT CORP,10240 SORRENTO VALLEY RD,SUITE 204,SAN DIEGO,CA 92121, USA. NR 45 TC 6 Z9 6 U1 3 U2 7 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 MAY PY 1991 VL 25 IS 5 BP 940 EP 951 DI 10.1021/es00017a018 PG 12 WC Engineering, Environmental; Environmental Sciences SC Engineering; Environmental Sciences & Ecology GA FK083 UT WOS:A1991FK08300024 ER PT J AU GOODRICH, DM BLUMBERG, AF AF GOODRICH, DM BLUMBERG, AF TI THE FORTNIGHTLY MEAN CIRCULATION OF CHESAPEAKE BAY SO ESTUARINE COASTAL AND SHELF SCIENCE LA English DT Article DE CURRENT MEASUREMENTS; CIRCULATION; RUNOFF; WIND; DENSITY GRADIENTS; MODELING; CHESAPEAKE BAY ID RIVER C1 HYDROQUAL INC,MAHWAH,NJ 07430. RP GOODRICH, DM (reprint author), NOAA,OFF GLOBAL PROGRAMS R-OGP,1335 E W HIGHWAY,SILVER SPRING,MD 20910, USA. NR 26 TC 19 Z9 19 U1 0 U2 1 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 MAY PY 1991 VL 32 IS 5 BP 451 EP 462 DI 10.1016/0272-7714(91)90034-9 PG 12 WC Marine & Freshwater Biology; Oceanography SC Marine & Freshwater Biology; Oceanography GA FP057 UT WOS:A1991FP05700003 ER PT J AU PEEPLES, TL HIROSUE, S OLSON, GJ KELLY, RM AF PEEPLES, TL HIROSUE, S OLSON, GJ KELLY, RM TI COAL SULFUR TRANSFORMATIONS MONITORED BY HYPERTHERMOPHILIC ARCHAEBACTERIA SO FUEL LA English DT Article; Proceedings Paper CT SYMP ON BIOTECHNOLOGY FOR THE PRODUCTION OF CLEAN FUELS CY AUG 27-28, 1990 CL WASHINGTON, DC DE MICROBIAL ACTIVITY; COAL; SULFUR ID PYROCOCCUS-FURIOSUS; LOW-TEMPERATURE; PYRITE OXIDATION; AIR OXIDATION; SULFUR; BACTERIA; REMOVAL; GENUS; NOV; XPS AB The hyperthermophilic archaebacterium Pyrococcus furiosus can reduce polysulphidic compounds as well as elemental sulphur bound in coal. The presence of elemental sulphur in coals is thought to be a result of low temperature oxidation, or weathering, of coal pyrite. Results of controlled coal weathering experiments, in which the transformation of sulphur moieties was monitored using P. furiosus as well as standard chemical analyses, suggest that there may be changes in the organic sulphur content of coal during treatment. Observed transformations make coal sulphur more amenable to reduction by P. furiosus and, perhaps, other sulphur-reducing bacteria. Along these lines, the potential basis for combined biological and chemical treatment of coal to remove organic sulphur should be given serious consideration in developing coal cleaning technology. C1 NATL INST STAND & TECHNOL,DIV POLYMERS,GAITHERSBURG,MD. RP PEEPLES, TL (reprint author), JOHNS HOPKINS UNIV,DEPT CHEM ENGN,BALTIMORE,MD 21218, USA. NR 40 TC 3 Z9 4 U1 1 U2 3 PU BUTTERWORTH-HEINEMANN LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD, OXON, ENGLAND OX5 1GB SN 0016-2361 J9 FUEL JI Fuel PD MAY PY 1991 VL 70 IS 5 BP 599 EP 604 DI 10.1016/0016-2361(91)90173-8 PG 6 WC Energy & Fuels; Engineering, Chemical SC Energy & Fuels; Engineering GA FL494 UT WOS:A1991FL49400008 ER PT J AU SOLER, T VANGELDER, BHW AF SOLER, T VANGELDER, BHW TI ON COVARIANCES OF EIGENVALUES AND EIGENVECTORS OF 2ND-RANK SYMMETRICAL TENSORS SO GEOPHYSICAL JOURNAL INTERNATIONAL LA English DT Note DE EIGENVALUES; EIGENVECTORS; PRINCIPAL STRAIN; PRINCIPAL STRESS ID MATRIX AB The applications of eigentheory to many branches of mathematical physics (e.g., rotational dynamics, continuum mechanics) is an unquestionable fact. This work expands the conventional methodology by introducing equations to compute the covariance matrices of eigenvalues and eigenvectors of second-rank 3-D symmetric tensors in terms of their six distinct elements error estimates. New analytical expressions derived herein are general and should be of interest to anyone concerned with the accuracy of the computed orientation of principal axes and their associated principal quantities (e.g., moments of inertia, stress, strain). C1 DELFT UNIV TECHNOL,FAC GEODET ENGN,2629 JA DELFT,NETHERLANDS. RP SOLER, T (reprint author), NOAA,NATL OCEAN SERV,CHARTING & GEODET SERV,NATL GEODET SURVEY,ROCKVILLE,MD 20852, USA. RI Soler, Tomas/F-6386-2010 NR 10 TC 20 Z9 20 U1 0 U2 2 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 MAY PY 1991 VL 105 IS 2 BP 537 EP 546 DI 10.1111/j.1365-246X.1991.tb06732.x PG 10 WC Geochemistry & Geophysics SC Geochemistry & Geophysics GA FL165 UT WOS:A1991FL16500020 ER PT J AU PALMER, RD CRUZ, JR ZRNIC, DS AF PALMER, RD CRUZ, JR ZRNIC, DS TI ENHANCED AUTOREGRESSIVE MOVING AVERAGE SPECTRAL ESTIMATION APPLIED TO THE MEASUREMENT OF DOPPLER SPECTRAL WIDTH SO IEEE TRANSACTIONS ON GEOSCIENCE AND REMOTE SENSING LA English DT Article ID WEATHER ECHOES; RADAR; TURBULENCE; ALGORITHM AB This paper investigates the measurement of clearair turbulence with a Doppler radar. Most methods, including ours, of estimating the intensity of turbulence are based on the Doppler spectral width, which is a measure of the variations of radial velocities within the resolution volume of the radar. Classical estimators of the spectral width use either the autocovariance or the periodogram. We propose an autoregressive moving average (ARMA) model to improve the Doppler spectral width estimates. An iterative algorithm that has its origin in system identification is used for the estimation of the ARMA parameters. By taking advantage of a priori knowledge of the correlation matrix, which arises in the derivation of the governing equations of the ARMA parameters, the ARMA spectral estimate can be improved. This improvement is shown in terms of bias and variance of the spectral width estimate. Furthermore, examples of the usefulness of this algorithm on actual experimental Doppler radar data are presented. C1 UNIV OKLAHOMA,SCH ELECT ENGN & COMP SCI,COMMUN & SIGNAL PROC LAB,NORMAN,OK 73019. NOAA,NATL SEVERE STORMS LAB,NORMAN,OK 73069. RP PALMER, RD (reprint author), CLEMSON UNIV,DEPT PHYS & ASTRON,CLEMSON,SC 29634, USA. NR 37 TC 8 Z9 8 U1 0 U2 0 PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017-2394 SN 0196-2892 J9 IEEE T GEOSCI REMOTE JI IEEE Trans. Geosci. Remote Sensing PD MAY PY 1991 VL 29 IS 3 BP 358 EP 368 DI 10.1109/36.79426 PG 11 WC Geochemistry & Geophysics; Engineering, Electrical & Electronic; Remote Sensing; Imaging Science & Photographic Technology SC Geochemistry & Geophysics; Engineering; Remote Sensing; Imaging Science & Photographic Technology GA FK385 UT WOS:A1991FK38500002 ER PT J AU RICE, P MORELAND, J AF RICE, P MORELAND, J TI TUNNELING-STABILIZED MAGNETIC FORCE MICROSCOPY OF BIT TRACKS ON A HARD DISK SO IEEE TRANSACTIONS ON MAGNETICS LA English DT Article ID FILM DISK AB A scanning tunneling microscope (STM) for surface magnetic force measurements on thin-film longitudinal magnetic storage media has been adapted. The usual rigid PtIr tip of the STM was replaced by a flexible Fe film tip. Images of a hard disk showing bit tracks written by a ferrite head in a computer disk drive are presented. The images shown are comparable to images of the bit tracks on textured surfaces using either ferrofluid decoration or other magnetic force microscopy (MFM) imaging techniques. The sensitivity of the Fe film tip was such that the influence on the image due to magnetic forces was larger than the influence due to sample surface topography. RP RICE, P (reprint author), NATL INST STAND & TECHNOL,DIV ELECTROMAGNET TECHNOL,SUPERCOND & MAGNET MEASUREMENTS GRP,BOULDER,CO 80303, USA. NR 12 TC 22 Z9 22 U1 0 U2 8 PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017-2394 SN 0018-9464 J9 IEEE T MAGN JI IEEE Trans. Magn. PD MAY PY 1991 VL 27 IS 3 BP 3452 EP 3454 DI 10.1109/20.79082 PG 3 WC Engineering, Electrical & Electronic; Physics, Applied SC Engineering; Physics GA FK384 UT WOS:A1991FK38400007 ER PT J AU ALBUS, JS AF ALBUS, JS TI OUTLINE FOR A THEORY OF INTELLIGENCE SO IEEE TRANSACTIONS ON SYSTEMS MAN AND CYBERNETICS LA English DT Article ID CORTEX; ARCHITECTURE AB Intelligence is defined as that which produces successful behavior. Intelligence is assumed to result from natural selection. A model is proposed that integrates knowledge from research in both natural and artificial systems. The model consists of a hierarchical system architecture wherein: 1) control bandwidth decreases about an order of magnitude at each higher level, 2) perceptual resolution of spatial and temporal patterns contracts about an order-of-magnitude at each higher level, 3) goals expand in scope and planning horizons expand in space and time about an order-of-magnitude at each higher level, and 4) models of the world and memories of events expand their range in space and time by about an order-of-magnitude at each higher level. At each level, functional modules perform behavior generation (task decomposition planning and execution), world modeling, sensory processing, and value judgment. Sensory feedback control loops are closed at every level. RP ALBUS, JS (reprint author), NATL INST STAND & TECHNOL,CTR MFG ENGN,MFG ENGN LAB,DIV ROBOT SYST,GAITHERSBURG,MD 20899, USA. NR 64 TC 183 Z9 184 U1 0 U2 13 PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017-2394 SN 0018-9472 J9 IEEE T SYST MAN CYB JI IEEE Trans. Syst. Man Cybern. PD MAY-JUN PY 1991 VL 21 IS 3 BP 473 EP 509 DI 10.1109/21.97471 PG 37 WC Computer Science, Cybernetics; Engineering, Electrical & Electronic SC Computer Science; Engineering GA GJ600 UT WOS:A1991GJ60000001 ER PT J AU TANG, S JIN, GX SENGERS, JV AF TANG, S JIN, GX SENGERS, JV TI THERMODYNAMIC PROPERTIES OF 1,1,1,2-TETRAFLUOROETHANE (R134A) IN THE CRITICAL REGION SO INTERNATIONAL JOURNAL OF THERMOPHYSICS LA English DT Article DE CRITICAL PHENOMENA; EQUATION OF STATE; R134A; REFRIGERANTS; SOUND VELOCITY; SPECIFIC HEAT ID NONASYMPTOTIC CRITICAL-BEHAVIOR; RENORMALIZATION-GROUP; INTERFACIAL-TENSION; CROSSOVER FUNCTIONS; VAPOR-PRESSURES; FIELD-THEORY; FLUIDS; CHLOROFLUOROCARBONS; MIXTURES AB A theoretically based simplified crossover model, which is capable of representing the thermodynamic properties of fluids in a large range of temperatures and densities around the critical point, is presented. The model is used to predict the thermodynamic properties of R134a in the critical region from a limited amount of available experimental information. Values for various thermodynamic properties of R134a at densities from 2 to 8 mol.L-1 and at temperatures from 365 to 450 K are presented. C1 NATL INST STAND & TECHNOL,DIV THERMOPHYS,GAITHERSBURG,MD 20899. RP TANG, S (reprint author), UNIV MARYLAND,INST PHYS SCI & TECHNOL,COLLEGE PK,MD 20742, USA. NR 49 TC 21 Z9 21 U1 0 U2 1 PU PLENUM PUBL CORP PI NEW YORK PA 233 SPRING ST, NEW YORK, NY 10013 SN 0195-928X J9 INT J THERMOPHYS JI Int. J. Thermophys. PD MAY PY 1991 VL 12 IS 3 BP 515 EP 540 DI 10.1007/BF00502366 PG 26 WC Thermodynamics; Chemistry, Physical; Mechanics; Physics, Applied SC Thermodynamics; Chemistry; Mechanics; Physics GA FG925 UT WOS:A1991FG92500007 ER PT J AU WILCZAK, JM DABBERDT, WF KROPFLI, RA AF WILCZAK, JM DABBERDT, WF KROPFLI, RA TI OBSERVATIONS AND NUMERICAL-MODEL SIMULATIONS OF THE ATMOSPHERIC BOUNDARY-LAYER IN THE SANTA-BARBARA COASTAL REGION SO JOURNAL OF APPLIED METEOROLOGY LA English DT Article ID CATALINA EDDY; DENVER CYCLONE; MESOSCALE; CALIFORNIA AB Observations of boundary-layer flow within the Santa Barbara region taken on 20 September 1985 reveal the presence of a wide variety of flow features, including mesoscale wind vortices, sea/land breezes, and thermally driven upslope/downslope winds. Details of these features, in particular the mesoscale vortices, are documented with dual-Doppler radar, Doppler sodar, aircraft, surface mesonet, and rawinsonde data. Numerical simulations of flow in the region using a mixed-layer model show good agreement with the observations. Model simulations indicate that sea-/land-roughness differences and planetary vorticity are of minor importance in forming the midchannel eddy (MCE), an eddy that is observed in the channel during the early morning hours. MCE formation is, however, shown to be strongly dependent on the initial stratification of the atmosphere, with more intense eddies forming as the stability increases. A second independent mechanism for MCE formation appears to be the interaction of drainage flows with the large-scale flow. A daytime vortex, known as the Gaviota eddy, occurs as the result of surface heating that generates a sea-breeze flow opposing the large-scale ambient flow. RP WILCZAK, JM (reprint author), NOAA,ENVIRONM RES LAB,WAVE PROPAGAT LAB,REWP7,325 BROADWAY,BOULDER,CO 80303, USA. NR 12 TC 14 Z9 14 U1 0 U2 4 PU AMER METEOROLOGICAL SOC PI BOSTON PA 45 BEACON ST, BOSTON, MA 02108-3693 SN 0894-8763 J9 J APPL METEOROL JI J. Appl. Meteorol. PD MAY PY 1991 VL 30 IS 5 BP 652 EP 673 DI 10.1175/1520-0450(1991)030<0652:OANMSO>2.0.CO;2 PG 22 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA FT300 UT WOS:A1991FT30000009 ER PT J AU SARMA, AD COLE, RS AF SARMA, AD COLE, RS TI EFFECT OF MULTIPATH AND SNOW ON MILLIMETER-WAVE SCINTILLATIONS ON A 4.1-KM LINE-OF-SIGHT LINK SO JOURNAL OF ATMOSPHERIC AND TERRESTRIAL PHYSICS LA English DT Article ID ABSORPTION REGION; AMPLITUDE SCINTILLATIONS; SPECTRAL DENSITY; FLUCTUATIONS; PROPAGATION; FREQUENCY AB Multipath propagation can occur for various reasons. For example, it can be due to sudden changes in the refractive index of the propagation medium or to reflections from melting snow/ice. We find that dry snow, or even 'moist' snow at 0-degrees-C, has no measurable effect on the propagation of radio waves up to at least 54.5 GHz. When multipath propagation occurs, the low frequency part of the scintillation spectrum is distorted. The usual theoretical predictions applicable to line-of-sight millimeter wave propagaton through clear air turbulence must be used with caution when the scintillations of the propagating signals are a result of multipath effects. It is also noted that propagation through vegetation greatly distorts the clear-air scintillation spectrum. Saturation of scintillations, which can also dramatically alter the scintillation spectrum, is not expected to be a problem for millimeter wave propagation over line-of-sight paths. C1 UNIV LONDON UNIV COLL,DEPT ELECTR & ELECT ENGN,LONDON WC1E 7JE,ENGLAND. RP SARMA, AD (reprint author), NOAA,ERL,WAVE PROPAGAT LAB,325 BROADWAY,BOULDER,CO 80303, USA. NR 24 TC 0 Z9 0 U1 0 U2 0 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD, ENGLAND OX5 1GB SN 0021-9169 J9 J ATMOS TERR PHYS JI J. Atmos. Terr. Phys. PD MAY PY 1991 VL 53 IS 5 BP 369 EP 378 DI 10.1016/0021-9169(91)90032-3 PG 10 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA GE765 UT WOS:A1991GE76500002 ER PT J AU MARGOLIS, SA JASSIE, L KINGSTON, HM AF MARGOLIS, SA JASSIE, L KINGSTON, HM TI THE HYDROLYSIS OF PROTEINS BY MICROWAVE-ENERGY SO JOURNAL OF AUTOMATIC CHEMISTRY LA English DT Article ID AMINO-ACID ANALYSIS; SERUM-ALBUMIN; PEPTIDES AB Microwave energy, at manually-adjusted, partial power settings has been used to hydrolyse bovine serum albumin at 125-degrees-C. Hydrolysis was complete within 2 h, except for valine and isoleucine which were completely liberated within 4 h. The amino-acid destruction was less than that observed at similar hydrolysis conditions with other methods and complete hydrolysis was achieved more rapidly. These results provide a basis for automating the process of amino-acid hydrolysis. RP MARGOLIS, SA (reprint author), NATL INST STAND & TECHNOL,CTR ANALYT CHEM,DIV ORGAN ANALYT RES,GAITHERSBURG,MD 20899, USA. NR 13 TC 10 Z9 11 U1 0 U2 3 PU TAYLOR & FRANCIS LTD PI LONDON PA ONE GUNDPOWDER SQUARE, LONDON, ENGLAND EC4A 3DE SN 0142-0453 J9 J AUTOM CHEM JI J. Autom. Chem. PD MAY-JUN PY 1991 VL 13 IS 3 BP 93 EP 95 DI 10.1155/S1463924691000172 PG 3 WC Biochemical Research Methods; Chemistry, Multidisciplinary; Instruments & Instrumentation SC Biochemistry & Molecular Biology; Chemistry; Instruments & Instrumentation GA GB370 UT WOS:A1991GB37000002 PM 18924889 ER PT J AU SCHUDER, MD NELSON, DD NESBITT, DJ AF SCHUDER, MD NELSON, DD NESBITT, DJ TI INVESTIGATION OF INTERNAL ROTOR DYNAMICS OF NEDCL AND ARDCL VIA INFRARED-ABSORPTION SPECTROSCOPY SO JOURNAL OF CHEMICAL PHYSICS LA English DT Article ID HIGH-RESOLUTION SPECTROSCOPY; POTENTIAL-ENERGY SURFACE; ANISOTROPIC INTERMOLECULAR FORCES; AR-HCL; VANDERWAALS COMPLEXES; LASER SPECTROSCOPY; ARHCL; SPECTRUM; VIBRATION; BANDS AB The van der Waals complexes, NeDCl and ArDCl, are produced in a slit jet supersonic expansion and observed via direct absorption of tunable mid-infrared Pb-salt diode laser radiation. For the NeDCl complex, the DCl stretch fundamental [nu-o = 2091.3717(4) cm-1] and the DCl SIGMA and PI-e,f bend combination bands [nu-0 = 2099.5760(4) and 2104.9465(4) cm-1, respectively] are observed. The DCl stretch fundamental and PI-e,f combination band are observed for ArDCl at 2089.4180(2) and 2117.4443(3) cm-1, respectively. The relative fundamental vs bend combination band intensity distributions are very different for the two complexes. The ArDCl fundamental to II bend combination band intensity ratio is 4:1, whereas for NeDCl the corresponding ratio is 1:8. This anomalous intensity pattern for NeDCl and the proximity of the bend combination bands to the DCl R(0) line indicate that the DCl diatomic is exhibiting nearly free rotation within this complex, compared to more restricted librational motion of DCl in ArDCl. Strong Coriolis interactions between Pi-e and SIGMA bend states are observed for both complexes and analyzed quantitatively for NeDCl. The observed NeDCl and ArDCl absorption linewidths are only slightly larger than the instrumental limit determined from nearby OCS monomer absorptions in the slit jet, but the differences are not of high statistical significance. This FWHM of the observed transitions dictates a rigorous lower limit to the vibrational predissociation lifetime of 3 ns. Experimentally determined rotational constants, vibrational frequencies, and relative intensities are compared to predictions based on existing empirical potential surfaces. C1 UNIV COLORADO,DEPT CHEM & BIOCHEM,BOULDER,CO 80309. RP SCHUDER, MD (reprint author), UNIV COLORADO,NATL INST STAND & TECHNOL,JOINT INST LAB ASTROPHYS,BOULDER,CO 80302, USA. NR 47 TC 24 Z9 24 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 MAY 1 PY 1991 VL 94 IS 9 BP 5796 EP 5811 DI 10.1063/1.460464 PG 16 WC Chemistry, Physical; Physics, Atomic, Molecular & Chemical SC Chemistry; Physics GA FH765 UT WOS:A1991FH76500002 ER PT J AU CALLANAN, JE WEIR, RD AF CALLANAN, JE WEIR, RD TI THE THERMODYNAMICS OF THE DIVALENT-METAL FLUORIDES .4. HEAT-CAPACITY OF MSNF4, M = PB, BA, OR SR, AT TEMPERATURES FROM 300-K TO 660-K SO JOURNAL OF CHEMICAL THERMODYNAMICS LA English DT Article ID FAST IONIC-CONDUCTION; PBSNF4; SOLIDS; BASNF4 C1 ROYAL MIL COLL CANADA,DEPT CHEM & CHEM ENGN,KINGSTON K7K 5L0,ONTARIO,CANADA. RP CALLANAN, JE (reprint author), NATL INST STAND & TECHNOL,CTR CHEM ENGN,BOULDER,CO 80303, USA. NR 32 TC 3 Z9 3 U1 0 U2 2 PU ACADEMIC PRESS LTD PI LONDON PA 24-28 OVAL RD, LONDON, ENGLAND NW1 7DX SN 0021-9614 J9 J CHEM THERMODYN JI J. Chem. Thermodyn. PD MAY PY 1991 VL 23 IS 5 BP 411 EP 420 DI 10.1016/S0021-9614(05)80129-6 PG 10 WC Thermodynamics; Chemistry, Physical SC Thermodynamics; Chemistry GA FL213 UT WOS:A1991FL21300003 ER PT J AU HARRISON, DE AF HARRISON, DE TI EQUATORIAL SEA-SURFACE TEMPERATURE SENSITIVITY TO NET SURFACE HEAT-FLUX - SOME OCEAN CIRCULATION MODEL RESULTS SO JOURNAL OF CLIMATE LA English DT Note AB Several primitive-equation ocean general circulation model experiments have been carried out in order to explore the sensitivity of equatorial sea surface temperature (SST) results to uncertainty in the net surface heat flux (Q) imposed at the surface. Both climatological seasonal cycle experiments and hindcasts of the 1982/83 ENSO event are considered. It is found that regions of light winds, which typically reach values of SST in excess of 31-degrees-C using this ocean model and past Q parameterizations, attain more realistic SST values of 29-degrees-30-degrees-C when Q is reduced by as little as 10 W m-2. Sensitivity in this regime is about 0.1-0.2-degrees-C (W m-2)-1 for low-frequency SST changes. In regions of easterly winds with their associated upwelling, horizontal advection, and stronger mixing, changes of Q in excess of 50 W m-2 produce SST changes typically of 0.7-degrees-C, for a sensitivity of about 0.02-degrees-C (W m-2)-1. These results apply equally well to the ENSO hindcasts and the seasonal cycle studies. The reasons for the large variation in sensitivity and the very large sensitivity under light winds are described. To the extent that these results are representative of oceanic conditions, very accurate Q information will be required for studies of the low-frequency variability of SST in light wind regions like the western Pacific; much less accurate fluxes appear needed for studies of comparable variability in upwelling regions. RP HARRISON, DE (reprint author), NOAA,PMEL,7600 SAND POINT WAY NE,SEATTLE,WA 98115, USA. RI Harrison, Don/D-9582-2013 NR 0 TC 24 Z9 25 U1 0 U2 0 PU AMER METEOROLOGICAL SOC PI BOSTON PA 45 BEACON ST, BOSTON, MA 02108-3693 SN 0894-8755 J9 J CLIMATE JI J. Clim. PD MAY PY 1991 VL 4 IS 5 BP 539 EP 549 DI 10.1175/1520-0442(1991)004<0539:ESSTST>2.0.CO;2 PG 11 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA FM995 UT WOS:A1991FM99500005 ER PT J AU YAN, LG SWANSON, P DICKHOFF, WW AF YAN, LG SWANSON, P DICKHOFF, WW TI BINDING OF GONADOTROPINS (GTH-I AND GTH-II) TO COHO SALMON GONADAL MEMBRANE PREPARATIONS SO JOURNAL OF EXPERIMENTAL ZOOLOGY LA English DT Article ID FOLLICLE-STIMULATING HORMONE; PITUITARY GONADOTROPHS; ONCORHYNCHUS-RHODURUS; RECEPTORS; PURIFICATION; SUBUNITS; INVITRO; GLANDS; OVARY; SITES AB This study was designed to optimize binding conditions of salmon gonadotropins (GTH I and GTH II) to membrane preparations of salmon gonadal tissues. Coho salmon (Oncorhynchus kisutch) GTH I and GTH II were radioiodinated by lactoperoxidase method. Binding conditions were characterized using membrane preparations from coho salmon postovulatory ovaries. The optimal conditions for specific binding were the following: pH 7.5, 20-40 mM MgCl2, 15-degrees-C, greater-than-or-equal-to 24 hr incubation time. Specific binding of I-125-GTH I or I-125-GTH II can be displaced by (in order of relative potency from high to low) GTH I, GTH II, GTH I beta-subunit, and GTH II beta-subunit. GTH alpha-subunit did not displace labeled GTHs, but the mixture of alpha- and beta-subunits was more potent than the beta-subunits alone, indicating that recombination of subunits probably occurred. In membranes of postovulatory ovaries, the affinity of the receptor(s) for GTH I was higher, Kd = 0.87 +/- 0.12 nM (mean +/- SEM), than that for GTH II, Kd = 2.76 +/- 0.33 nM; but the receptor density (capacity) was lower for GTH I (31.02 +/- 3.72 fmol/mg protein) than that for GTH II (47.01 +/- 4.77 fmol/mg protein). Specific binding for both GTH I and GTH II was also detected in membranes of ovaries and testes of immature coho salmon. These results suggest the presence of some shared and some separate binding sites for the two gonadotropins. C1 NATL MARINE FISHERIES SERV,NW FISHERIES CTR,DIV COASTAL ZONE & ESTUARINE STUDIES,SEATTLE,WA 98112. RP YAN, LG (reprint author), UNIV WASHINGTON,SCH FISHERIES,HF-15,SEATTLE,WA 98195, USA. NR 35 TC 15 Z9 15 U1 0 U2 2 PU WILEY-LISS PI NEW YORK PA DIV JOHN WILEY & SONS INC 605 THIRD AVE, NEW YORK, NY 10158-0012 SN 0022-104X J9 J EXP ZOOL JI J. Exp. Zool. PD MAY PY 1991 VL 258 IS 2 BP 221 EP 230 DI 10.1002/jez.1402580212 PG 10 WC Zoology SC Zoology GA FL856 UT WOS:A1991FL85600011 ER PT J AU RAVESI, EM KRZYNOWEK, J AF RAVESI, EM KRZYNOWEK, J TI VARIABILITY OF SALT ABSORPTION BY BRINE DIPPED FILLETS OF COD (GADUS-MORHUA), BLACKBACK FLOUNDER (PSEUDOPLEURONECTES-AMERICANUS), AND OCEAN PERCH (SEBASTES-MARINUS) SO JOURNAL OF FOOD SCIENCE LA English DT Article AB Major changes in sodium content of fillets of cod, blackback flounder, and ocean perch resulted from varying concentration of brine solution (5, 10, or 15%), duration of dip (30, 60 or 90 sec), fillet thickness, season of catch, and rinsing or skinning fillets before cooking. Post-mortem age (1-5 days) of fish, temperature of brine solution (6, 12, or 20-degrees-C), and cooking had minor effects on final sodium concentration. RP RAVESI, EM (reprint author), NATL MARINE FISHERIES SERV,NE FISHERIES CTR,30 EMERSON AVE,GLOUCESTER,MA 01930, USA. NR 29 TC 7 Z9 7 U1 0 U2 1 PU INST FOOD TECHNOLOGISTS PI CHICAGO PA SUITE 300 221 N LASALLE ST, CHICAGO, IL 60601-1291 SN 0022-1147 J9 J FOOD SCI JI J. Food Sci. PD MAY-JUN PY 1991 VL 56 IS 3 BP 648 EP 652 DI 10.1111/j.1365-2621.1991.tb05348.x PG 5 WC Food Science & Technology SC Food Science & Technology GA FY154 UT WOS:A1991FY15400014 ER PT J AU MONTZKA, SA HYBERTSON, BM BARKLEY, RM SIEVERS, RE AF MONTZKA, SA HYBERTSON, BM BARKLEY, RM SIEVERS, RE TI LOW-TEMPERATURE OXIDATION OF YBA2CU3O6.0 WITH NITROGEN-DIOXIDE SO JOURNAL OF MATERIALS RESEARCH LA English DT Article ID BA-CU-O; CHEMI-LUMINESCENCE DETECTOR; PLASMA OXIDATION; THIN-FILMS; SUPERCONDUCTIVITY; OXYGEN; OXIDE; YBA2CU3O7-DELTA; CHROMATOGRAPHY; SYSTEM AB Nitrogen dioxide was used to oxidize nonsuperconducting, powered YBa2Cu3O6.0 to form a material that exhibits the Meissner effect at liquid nitrogen temperature. Nitrogen dioxide treatment at 200-degrees-C for 70 h results in a mixed-phase material containing superconducting YBa2Cu3O6.9 that exhibits onset of superconductivity at 91.5 K and a midpoint at 88 K. During a 70-h exposure of YBa2Cu3O6 to NO2 at 200-degrees-C, a mixture of oxidation and degradation products is formed, including YBa2Cu3O6.9 (61% by weight) and Ba(NO3)2 (23% by weight). Heating the NO2-treated product to 900-degrees-C results in the evolution of NO, NO2, and O2; cooling the sample and annealing at 400-degrees-C in an O2 stream generates the superconducting oxide. C1 UNIV COLORADO, DEPT CHEM & BIOCHEM, BOULDER, CO 80309 USA. UNIV COLORADO, NOAA, COOPERAT INST RES ENVIRONM SCI, BOULDER, CO 80309 USA. OI Montzka, Stephen/0000-0002-9396-0400 NR 25 TC 5 Z9 5 U1 0 U2 0 PU CAMBRIDGE UNIV PRESS PI NEW YORK PA 32 AVENUE OF THE AMERICAS, NEW YORK, NY 10013-2473 USA SN 0884-2914 EI 2044-5326 J9 J MATER RES JI J. Mater. Res. PD MAY PY 1991 VL 6 IS 5 BP 891 EP 894 DI 10.1557/JMR.1991.0891 PG 4 WC Materials Science, Multidisciplinary SC Materials Science GA FK039 UT WOS:A1991FK03900003 ER PT J AU LATHABAI, S RODEL, J DABBS, T LAWN, BR AF LATHABAI, S RODEL, J DABBS, T LAWN, BR TI FRACTURE-MECHANICS MODEL FOR SUBTHRESHOLD INDENTATION FLAWS .2. NONEQUILIBRIUM FRACTURE SO JOURNAL OF MATERIALS SCIENCE LA English DT Article ID OPTICAL-GLASS FIBERS; SODA-LIME GLASS; CRACK INITIATION; DYNAMIC FATIGUE; FAILURE; DEFORMATION; STRENGTH; CERAMICS AB In Part II of this two-part study we extend the shear-fault-microcrack model to non-equilibrium fracture, to allow for rate effects in the critical instability configurations in chemically interactive environments. The "calibrated" K-fields of Part I are combined with independently evaluated crack velocity functions to determine kinetic conditions for microcrack extension. The analysis enables evaluation of (i) a time delay in radial crack pop-in from a subthreshold flaw; (ii) a time dependence in the strength characteristics, in both the subthreshold and postthreshold domains. Comparisons with delayed pop-in and strength-stressing-rate literature data for silicate glasses in moist environments indicate that the analysis is capable of quantitative predictions of kinetic characteristics. In the strength data, the model accounts for the relatively high magnitudes, scatter and fatigue susceptibilities in the subthreshold region. RP LATHABAI, S (reprint author), NATL INST STAND & TECHNOL,DIV CERAM,GAITHERSBURG,MD 20899, USA. NR 29 TC 16 Z9 16 U1 0 U2 0 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 MAY 1 PY 1991 VL 26 IS 9 BP 2313 EP 2321 DI 10.1007/BF01130175 PG 9 WC Materials Science, Multidisciplinary SC Materials Science GA FL475 UT WOS:A1991FL47500007 ER PT J AU COUDERT, LH MATSUMURA, K LOVAS, FJ AF COUDERT, LH MATSUMURA, K LOVAS, FJ TI THE ROTATIONAL-TUNNELING SPECTRUM OF THE AR-SO2 VANDERWAALS COMPLEX SO JOURNAL OF MOLECULAR SPECTROSCOPY LA English DT Article ID INFRARED-LASER SPECTROSCOPY; WATER DIMER; MICROWAVE; ARHCL; BONDS; AR C1 UNIV PARIS 06,PHYS MOLEC & ATMOSPHER LAB,F-75252 PARIS 05,FRANCE. CNRS,F-75252 PARIS 05,FRANCE. SEINAN GAKUIN UNIV,SARWARA KU,FUKUOKA 814,JAPAN. RP COUDERT, LH (reprint author), NATL INST STAND & TECHNOL,DIV MOLEC PHYS,GAITHERSBURG,MD 20899, USA. NR 14 TC 15 Z9 15 U1 0 U2 0 PU ACADEMIC PRESS INC JNL-COMP SUBSCRIPTIONS PI SAN DIEGO PA 525 B ST, STE 1900, SAN DIEGO, CA 92101-4495 SN 0022-2852 J9 J MOL SPECTROSC JI J. Mol. Spectrosc. PD MAY PY 1991 VL 147 IS 1 BP 46 EP 60 DI 10.1016/0022-2852(91)90167-9 PG 15 WC Physics, Atomic, Molecular & Chemical; Spectroscopy SC Physics; Spectroscopy GA FH196 UT WOS:A1991FH19600005 ER PT J AU KLEINER, I FRASER, GT HOUGEN, JT PINE, AS AF KLEINER, I FRASER, GT HOUGEN, JT PINE, AS TI MOLECULAR-BEAM OPTOTHERMAL SPECTRUM OF THE OH STRETCHING BAND OF METHANOL SO JOURNAL OF MOLECULAR SPECTROSCOPY LA English DT Article ID MILLIMETER-WAVE SPECTRUM; GASEOUS METHYL-ALCOHOL; DIODE-LASER SPECTRA; HIGH-RESOLUTION; FOURIER SPECTRUM; CH3OH; ROTATION; CM-1; MICROWAVE; STATES RP KLEINER, I (reprint author), NATL INST STAND & TECHNOL,DIV MOLEC PHYS,GAITHERSBURG,MD 20899, USA. NR 42 TC 39 Z9 39 U1 0 U2 6 PU ACADEMIC PRESS INC JNL-COMP SUBSCRIPTIONS PI SAN DIEGO PA 525 B ST, STE 1900, SAN DIEGO, CA 92101-4495 SN 0022-2852 J9 J MOL SPECTROSC JI J. Mol. Spectrosc. PD MAY PY 1991 VL 147 IS 1 BP 155 EP 172 DI 10.1016/0022-2852(91)90176-B PG 18 WC Physics, Atomic, Molecular & Chemical; Spectroscopy SC Physics; Spectroscopy GA FH196 UT WOS:A1991FH19600014 ER PT J AU MAKI, AG WELLS, JS BURKHOLDER, JB AF MAKI, AG WELLS, JS BURKHOLDER, JB TI HIGH-RESOLUTION MEASUREMENTS OF THE BANDS OF CARBONYL SULFIDE BETWEEN 2510 AND 3150 CM-1 SO JOURNAL OF MOLECULAR SPECTROSCOPY LA English DT Article ID GLOBAL ROVIBRATIONAL ANALYSIS; OCS; SPECTROSCOPY; HETERODYNE; FREQUENCY; SPECTRA C1 NATL INST STAND & TECHNOL,DIV MOLEC PHYS,GAITHERSBURG,MD 20899. NATL INST STAND & TECHNOL,DIV TIME & FREQUENCY,BOULDER,CO 80303. NOAA,BOULDER,CO 80303. COOPERAT INST RES ENVIRONM SCI,BOULDER,CO 80303. RI Burkholder, James/H-4914-2013 NR 18 TC 15 Z9 15 U1 0 U2 2 PU ACADEMIC PRESS INC JNL-COMP SUBSCRIPTIONS PI SAN DIEGO PA 525 B ST, STE 1900, SAN DIEGO, CA 92101-4495 SN 0022-2852 J9 J MOL SPECTROSC JI J. Mol. Spectrosc. PD MAY PY 1991 VL 147 IS 1 BP 173 EP 181 DI 10.1016/0022-2852(91)90177-C PG 9 WC Physics, Atomic, Molecular & Chemical; Spectroscopy SC Physics; Spectroscopy GA FH196 UT WOS:A1991FH19600015 ER PT J AU FONG, JT BERNSTEIN, B AF FONG, JT BERNSTEIN, B TI A PC-BASED MODELING TOOL FOR CREEP, FATIGUE, AND CREEP-FATIGUE INTERACTIONS USING A VISCOPLASTICITY THEORY SO JOURNAL OF PRESSURE VESSEL TECHNOLOGY-TRANSACTIONS OF THE ASME LA English DT Article AB Computational results for modeling one-dimensional stress relaxation, creep, fatigue, and creep-fatigue interaction phenomena of metals at elevated temperatures using a unifying thermodynamic theory of viscoplasticity are presented. The theory incorporates in a nonequilibrium formulation the idea of a "concealed" parameter alpha, originally due to Bridgman (1950), where the constitutive equations are governed by 1) a thermodynamic potential such as the Helmholtz free energy function F with an explicit dependence on alpha, and 2) a prescription for alpha, the time rate of change of alpha, such that alpha is proportional to -F(alpha), the negative of the partial derivative of F with respect to alpha. Significance of the results and a comparison with other modeling tools in the literature are discussed. C1 NATL INST STAND & TECHNOL,DIV APPL & COMPUTAT MATH,GAITHERSBURG,MD 20899. IIT,DEPT MATH,CHICAGO,IL 60616. NR 23 TC 0 Z9 0 U1 0 U2 0 PU ASME-AMER SOC MECHANICAL ENG PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 SN 0094-9930 J9 J PRESS VESS-T ASME JI J. Press. Vessel Technol.-Trans. ASME PD MAY PY 1991 VL 113 IS 2 BP 174 EP 179 DI 10.1115/1.2928744 PG 6 WC Engineering, Mechanical SC Engineering GA HP754 UT WOS:A1991HP75400011 ER PT J AU PERKINS, RA RODER, HM DECASTRO, CAN AF PERKINS, RA RODER, HM DECASTRO, CAN TI A HIGH-TEMPERATURE TRANSIENT HOT-WIRE THERMAL-CONDUCTIVITY APPARATUS FOR FLUIDS SO JOURNAL OF RESEARCH OF THE NATIONAL INSTITUTE OF STANDARDS AND TECHNOLOGY LA English DT Article DE ARGON; HEAT CAPACITY; NITROGEN; RADIATION CORRECTION; THERMAL CONDUCTIVITY; THERMAL DIFFUSIVITY; TOLUENE; TRANSIENT HOT-WIRE ID CARBON-MONOXIDE; HEAT-CAPACITY; NITROGEN; ARGON; PRESSURES AB A new apparatus for measuring both the thermal conductivity and thermal diffusivity of fluids at temperatures from 220 to 775 K at pressures to 70 MPa is described. The instrument is based on the step-power-forced transient hot-wire technique. Two hot wires are arranged in different arms of a Wheatstone bridge such that the response of the shorter compensating wire is subtracted from the response of the primary wire. Both hot wires are 12.7-mu-m diameter platinum wire and are simultaneously used as electrical heat sources and as resistance thermometers. A microcomputer controls bridge nulling, applies the power pulse, monitors the bridge response, and stores the results. Performance of the instrument was verified with measurements on liquid toluene as well as argon and nitrogen gas. In particular, new data for the thermal conductivity of liquid toluene near the saturation line, between 298 and 550 K, are presented. These new data can be used to illustrate the importance of radiative heat transfer in transient hot-wire measurements. Thermal conductivity data for liquid toluene, which are corrected for radiation, are reported. The precision of the thermal conductivity data is +/- 0.3% and the accuracy is about +/- 1%. The accuracy of the thermal diffusivity data is about +/- 5%. From the measured thermal conductivity and thermal diffusivity, we can calculate the specific heat, C(p), of the fluid, provided that the density is measured, or available through an equation of state. C1 UNIV LISBON, DEPT QUIM, P-1700 LISBON, PORTUGAL. RP PERKINS, RA (reprint author), NATL INST STAND & TECHNOL, DIV THERMOPHYS, CHEM SCI & TECHNOL LAB, BOULDER, CO 80303 USA. RI Nieto de Castro, Carlos/B-7377-2011; OI Nieto de Castro, Carlos/0000-0001-9011-5132; Perkins, Richard/0000-0002-8526-6742 NR 29 TC 43 Z9 44 U1 0 U2 9 PU US GOVERNMENT PRINTING OFFICE PI WASHINGTON PA SUPERINTENDENT DOCUMENTS,, WASHINGTON, DC 20402-9325 USA SN 1044-677X J9 J RES NATL INST STAN JI J. Res. Natl. Inst. Stand. Technol. PD MAY-JUN PY 1991 VL 96 IS 3 BP 247 EP 269 DI 10.6028/jres.096.014 PG 23 WC Instruments & Instrumentation; Physics, Applied SC Instruments & Instrumentation; Physics GA FV282 UT WOS:A1991FV28200001 PM 28184114 ER PT J AU SONG, JF VORBURGER, TV AF SONG, JF VORBURGER, TV TI STANDARD REFERENCE SPECIMENS IN QUALITY-CONTROL OF ENGINEERING SURFACES SO JOURNAL OF RESEARCH OF THE NATIONAL INSTITUTE OF STANDARDS AND TECHNOLOGY LA English DT Article DE CALIBRATION; ISO; QUALITY CONTROL; ROUGHNESS; ROUGHNESS AVERAGE; SPECIMEN; SRM; STANDARD; STANDARD REFERENCE MATERIAL; STEP HEIGHT; STYLUS; SURFACE ID ATOMIC FORCE MICROSCOPY; SCANNING TUNNELING MICROSCOPY; INSTRUMENT AB In the quality control of engineering surfaces, we aim to understand and maintain a good relationship between the manufacturing process and surface function. This is achieved by controlling the surface texture. The control process involves: 1) learning the functional parameters and their control values through controlled experiments or through a long history of production and use; 2) maintaining high accuracy and reproducibility with measurements not only of roughness calibration specimens but also of real engineering parts. In this paper, the characteristics, utilizations, and limitations of different classes of precision roughness calibration specimens are described. A measuring procedure of engineering surfaces, based on the calibration procedure of roughness specimens at NIST, is proposed. This procedure involves utilization of check specimens with waveform, wavelength, and other roughness parameters similar to functioning engineering surfaces. These check specimens would be certified under standardized reference measuring conditions, or by a reference instrument, and could be used for overall checking of the measuring procedure and for maintaining accuracy and agreement in engineering surface measurement. The concept of "surface texture design" is also suggested, which involves designing the engineering surface texture, the manufacturing process, and the quality control procedure to meet the optimal functional needs. C1 NATL INST STAND & TECHNOL, DIV PRECIS ENGN, SURFACE & PARTICLE METROL GRP, GAITHERSBURG, MD 20899 USA. RP SONG, JF (reprint author), NATL INST STAND & TECHNOL, DIV PRECIS ENGN, MFG ENGN LAB, GAITHERSBURG, MD 20899 USA. NR 47 TC 19 Z9 19 U1 0 U2 0 PU US GOVERNMENT PRINTING OFFICE PI WASHINGTON PA SUPERINTENDENT DOCUMENTS,, WASHINGTON, DC 20402-9325 USA SN 1044-677X J9 J RES NATL INST STAN JI J. Res. Natl. Inst. Stand. Technol. PD MAY-JUN PY 1991 VL 96 IS 3 BP 271 EP 289 DI 10.6028/jres.096.015 PG 19 WC Instruments & Instrumentation; Physics, Applied SC Instruments & Instrumentation; Physics GA FV282 UT WOS:A1991FV28200002 PM 28184115 ER PT J AU BERNING, D AF BERNING, D TI AN AUTOMATED REVERSE-BIAS 2ND-BREAKDOWN TRANSISTOR TESTER SO JOURNAL OF RESEARCH OF THE NATIONAL INSTITUTE OF STANDARDS AND TECHNOLOGY LA English DT Article DE AUTOMATED TESTING; CLAMP OVERSHOOT; CROWBAR; FAST SWITCHING; NONDESTRUCTIVE; PROTECTION CIRCUIT; REVERSE-BIAS; SAFE-OPERATING AREA; 2ND BREAKDOWN; TRANSISTOR AB An automated instrument is described for generating curves for the reverse-bias, safe-operating area of transistors nondestructively. A new technique for detecting second breakdown that makes automation possible is highlighted. Methods to reduce stress to the device under test are discussed, as are several other innovations that enhance automation. Measurements using the tester are described, and limitations on nondestructive testability are discussed. RP BERNING, D (reprint author), NATL INST STAND & TECHNOL, DIV SEMICOND ELECTR, ELECTR & ELECT ENGN LAB, GAITHERSBURG, MD 20899 USA. NR 6 TC 0 Z9 0 U1 0 U2 1 PU US GOVERNMENT PRINTING OFFICE PI WASHINGTON PA SUPERINTENDENT DOCUMENTS,, WASHINGTON, DC 20402-9325 USA SN 1044-677X J9 J RES NATL INST STAN JI J. Res. Natl. Inst. Stand. Technol. PD MAY-JUN PY 1991 VL 96 IS 3 BP 291 EP 304 DI 10.6028/jres.096.016 PG 14 WC Instruments & Instrumentation; Physics, Applied SC Instruments & Instrumentation; Physics GA FV282 UT WOS:A1991FV28200003 PM 28184116 ER PT J AU STEINER, B DOBBYN, RC BLACK, D BURDETTE, H KURIYAMA, M SPAL, R VANDENBERG, L FRIPP, A SIMCHICK, R LAL, RB BATRA, A MATTHIESEN, D DITCHEK, B AF STEINER, B DOBBYN, RC BLACK, D BURDETTE, H KURIYAMA, M SPAL, R VANDENBERG, L FRIPP, A SIMCHICK, R LAL, RB BATRA, A MATTHIESEN, D DITCHEK, B TI HIGH-RESOLUTION SYNCHROTRON X-RADIATION DIFFRACTION IMAGING OF CRYSTALS GROWN IN MICROGRAVITY AND CLOSELY RELATED TERRESTRIAL CRYSTALS SO JOURNAL OF RESEARCH OF THE NATIONAL INSTITUTE OF STANDARDS AND TECHNOLOGY LA English DT Article DE CRYSTAL GROWTH; DIFFRACTION; GALLIUM ARSENIDE; HIGH RESOLUTION; LEAD TIN TELLURIDE; MERCURIC IODIDE; MICROGRAVITY; SYNCHROTRON; TOPOGRAPHY; TRIGLYCINE SULFATE ID TOPOGRAPHY; SPACE AB Irregularities in three crystals grown in space and in four terrestrial crystals grown under otherwise comparable conditions have been observed in high resolution diffraction imaging. The images provide important new clues to the nature and origins of irregularities in each crystal. For two of the materials, mercuric iodide and lead tin telluride, more than one phase (an array of non diffracting inclusions) was observed in terrestrial samples; but the formation of these multiple phases appears to have been suppressed in directly comparable crystals grown in microgravity. The terrestrial seed crystal of triglycine sulfate displayed an unexpected layered structure, which propagated during directly comparable space growth. Terrestrial Bridgman regrowth of gallium arsenide revealed a mesoscopic structure substantially different from that of the original Czochralski material. A directly comparable crystal is to be grown shortly in space. C1 EG&G ENERGY MEASUREMENTS INC, GOLETA, CA 93116 USA. ALABAMA A&M UNIV, HUNTSVILLE, AL 35762 USA. NASA, LANGLEY RES CTR, HAMPTON, VA 23665 USA. GTE LABS INC, WALTHAM, MA 02254 USA. LOCKHEED ENGN & SCI CO, HAMPTON, VA USA. RP STEINER, B (reprint author), NATL INST STAND & TECHNOL, MAT SCI & ENGN & LAB, GAITHERSBURG, MD 20899 USA. NR 12 TC 2 Z9 2 U1 0 U2 1 PU US GOVERNMENT PRINTING OFFICE PI WASHINGTON PA SUPERINTENDENT DOCUMENTS,, WASHINGTON, DC 20402-9325 USA SN 1044-677X J9 J RES NATL INST STAN JI J. Res. Natl. Inst. Stand. Technol. PD MAY-JUN PY 1991 VL 96 IS 3 BP 305 EP 331 DI 10.6028/jres.096.017 PG 27 WC Instruments & Instrumentation; Physics, Applied SC Instruments & Instrumentation; Physics GA FV282 UT WOS:A1991FV28200004 PM 28184117 ER PT J AU SIMMONS, JA AF SIMMONS, JA TI ROOT PROJECTION OF ONE-SIDED TIME-SERIES SO JOURNAL OF RESEARCH OF THE NATIONAL INSTITUTE OF STANDARDS AND TECHNOLOGY LA English DT Article DE CAUSAL BOUNDARY ROOTS; GRAM-SCHMIDT ALGORITHM; PRONYS METHOD; ROOT PROJECTION; SIGNAL PROCESSING; TIME SERIES; Z-TRANSFORMS AB Until recently it has been impossible to accurately determine the roots of polynomials of high degree, even for polynomials derived from the Z transform of time series where the dynamic range of the coefficients is generally less than 100 dB. In a companion paper, two new programs for solving such polynomials were discussed and applied to signature analysis of one-sided time series [1]. We present here another technique, that of root projection (RP), together with a Gram-Schmidt method for implementing it on vectors of large dimension. This technique utilizes the roots of the Z transform of a one-sided time series to construct a weighted least squares modification of the time series whose Z transform has an appropriately modified root distribution. Such a modification can be employed in a manner which is very useful for filtering and deconvolution applications [2]. Examples given here include the use of boundary root projection for front end noise reduction and a generalization of Prony's method. RP SIMMONS, JA (reprint author), NATL INST STAND & TECHNOL,DIV MET,MAT SCI & ENGN LAB,GAITHERSBURG,MD 20899, USA. NR 9 TC 0 Z9 0 U1 0 U2 0 PU US GOVERNMENT PRINTING OFFICE PI WASHINGTON PA SUPT OF DOCUMENTS, WASHINGTON, DC 20402-9325 SN 1044-677X J9 J RES NATL INST STAN JI J. Res. Natl. Inst. Stand. Technol. PD MAY-JUN PY 1991 VL 96 IS 3 BP 333 EP 343 PG 11 WC Instruments & Instrumentation; Physics, Applied SC Instruments & Instrumentation; Physics GA FV282 UT WOS:A1991FV28200005 PM 28184118 ER PT J AU SIMMONS, JA AF SIMMONS, JA TI DECONVOLUTION OF ACOUSTIC-EMISSION AND OTHER CAUSAL TIME-SERIES SO JOURNAL OF RESEARCH OF THE NATIONAL INSTITUTE OF STANDARDS AND TECHNOLOGY LA English DT Article DE ACOUSTIC EMISSION; CAUSAL TIME SERIES; CROSS-CUT ALGORITHM; DECONVOLUTION; FFT DECONVOLUTION; GAUSSIAN DECONVOLUTION; ROOT PROJECTION; SIGNAL PROCESSING; SINGULAR VALUE DECOMPOSITION; TIME SERIES; TRANSDUCER CALIBRATION AB A new technique, root projection (RP), is given for quantitative deconvolution of causal time series in the presence of moderate amounts of noise. Deconvolution is treated as a well-conditioned but underdetermined problem and a priori information is employed to obtain comparable noise reduction to that achieved by singular value decomposition (SVD) techniques while providing more accurate frequency information about the inverse. Two detailed examples are given. The first gives noise analysis for alternate methods for deconvolution with a Gaussian kernel. The second example presents a model acoustic emission transducer calibration problem with typical noisy and incomplete output data. This example is treated by the use of a robust cross-cutting algorithm combining both the RP and SVD methods. RP SIMMONS, JA (reprint author), NATL INST STAND & TECHNOL, DIV MET, MAT SCI & ENGN LAB, GAITHERSBURG, MD 20899 USA. NR 5 TC 2 Z9 2 U1 1 U2 2 PU US GOVERNMENT PRINTING OFFICE PI WASHINGTON PA SUPERINTENDENT DOCUMENTS,, WASHINGTON, DC 20402-9325 USA SN 1044-677X J9 J RES NATL INST STAN JI J. Res. Natl. Inst. Stand. Technol. PD MAY-JUN PY 1991 VL 96 IS 3 BP 345 EP 369 DI 10.6028/jres.096.019 PG 25 WC Instruments & Instrumentation; Physics, Applied SC Instruments & Instrumentation; Physics GA FV282 UT WOS:A1991FV28200006 PM 28184119 ER PT J AU SOLER, T STRANGE, WE FERGUSON, JS AF SOLER, T STRANGE, WE FERGUSON, JS TI GEODETIC COORDINATE SYSTEMS IN FLORIDA - GPS CONTRIBUTION SO JOURNAL OF SURVEYING ENGINEERING-ASCE LA English DT Article AB Measurements and results derived from the three-dimensional Global Positioning System (GPS) are more accurate than classical geodetic observations and methods used until recently to define conventional horizontal (geometric) datums, e.g., the North American Datum of 1983, the final readjustment of which was finished in 1986, thus the notation NAD 83 (1986). The situation may not be strictly the same with respect to vertical (physical) datums such as the National Geodetic Vertical Datum of 1929 (NGVD 29) because an accurate geoid is required. In this paper comparisons of standard datums [NAD 83 (1986), NGVD 29] with recent GPS results in the state of Florida are analyzed. Their relationship with a very long baseline interferometry (VLBI) reference frame is also discussed. The investigation shows that overall the relative accuracy of NAD 83 (1986) in Florida is between 1/200,000 and 1/500,000 or from five to two parts per million (ppm), yet still not as good as the two-dimensional results derived from GPS. C1 NOAA,NATL OCEAN SERV,NATL GEODET SURVEY,CHARTING & GEODET SERV,ROCKVILLE,MD 20852. RP SOLER, T (reprint author), NOAA,NATL OCEAN SERV,NATL GEODET SURVEY,CHARTING & GEODET SERV,ROCKVILLE,MD 20852, USA. RI Soler, Tomas/F-6386-2010 NR 17 TC 1 Z9 1 U1 1 U2 2 PU ASCE-AMER SOC CIVIL ENG PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017-2398 SN 0733-9453 J9 J SURV ENG-ASCE JI J. Surv. Eng.-ASCE PD MAY PY 1991 VL 117 IS 2 BP 77 EP 97 DI 10.1061/(ASCE)0733-9453(1991)117:2(77) PG 21 WC Engineering, Civil SC Engineering GA FJ094 UT WOS:A1991FJ09400003 ER PT J AU MUNRO, RG BEGLEY, EF AF MUNRO, RG BEGLEY, EF TI THE STRUCTURAL CERAMICS DATABASE - DATA ACQUISITION FORMAT FOR MONOLITHIC CERAMICS SO JOURNAL OF TESTING AND EVALUATION LA English DT Article DE CERAMICS; COMPUTERIZATION; MATERIALS PROPERTIES; MECHANICAL PROPERTIES; THERMAL PROPERTIES; DATA FORMAT AB The Structural Ceramics Database (SCD) is being developed to provide a user-friendly, computerized database of materials properties for advanced ceramics. The acquisition and the maintenance of adequate and comprehensive data are two of the critical concerns that must be addressed in establishing a state of the art system. This paper describes the basic SCD format used for data on monolithic ceramics. This format prescribes a comprehensive means for tabulating, annotating, and crediting data. The experience gained in developing this format for the SCD is discussed in the context of the tissues confronting ASTM Committee E-49 on Computerization of Materials Property Data. RP MUNRO, RG (reprint author), NATL INST STAND & TECHNOL,DIV CERAM,GAITHERSBURG,MD 20899, USA. NR 8 TC 0 Z9 0 U1 0 U2 0 PU AMER SOC TESTING MATERIALS PI W CONSHOHOCKEN PA 100 BARR HARBOR DR, W CONSHOHOCKEN, PA 19428-2959 SN 0090-3973 J9 J TEST EVAL JI J. Test. Eval. PD MAY PY 1991 VL 19 IS 3 BP 250 EP 255 PG 6 WC Materials Science, Characterization & Testing SC Materials Science GA FL777 UT WOS:A1991FL77700010 ER PT J AU SHANG, EC WANG, YY AF SHANG, EC WANG, YY TI ENVIRONMENTAL MISMATCHING EFFECTS ON SOURCE LOCALIZATION PROCESSING IN MODE SPACE SO JOURNAL OF THE ACOUSTICAL SOCIETY OF AMERICA LA English DT Article ID MATCHED-FIELD LOCALIZATION; WATER PACIFIC ENVIRONMENT; SHALLOW-WATER; SENSITIVITY AB In this paper the source localization performance degradation of the matched field processing (MFP) caused by environmental mismatch has been discussed for HRMM processor [E. C. Shang, J. Acoust. Soc. Am. 86, 1960-1964 (1989)] in mode space analytically. By using the approximate modal eigenvalue solution, the analytic expressions for describing the impacts of water-depth mismatch in a Pekeris waveguide and sediment-type mismatch have been derived. By using the modal perturbation theory an indicator for assessing the range performance degradation caused by sound-speed profile (SSP) mismatch has been proposed. Analytic results have been verified by numerical simulations. RP SHANG, EC (reprint author), UNIV COLORADO,NOAA,COOPERAT INST RES ENVIRONM SCI,ENVIRONM RES LABS,WAVE PROPAGAT LAB,BOULDER,CO 80303, USA. NR 17 TC 36 Z9 49 U1 1 U2 3 PU AMER INST PHYSICS PI WOODBURY PA CIRCULATION FULFILLMENT DIV, 500 SUNNYSIDE BLVD, WOODBURY, NY 11797-2999 SN 0001-4966 J9 J ACOUST SOC AM JI J. Acoust. Soc. Am. PD MAY PY 1991 VL 89 IS 5 BP 2285 EP 2290 DI 10.1121/1.400919 PG 6 WC Acoustics; Audiology & Speech-Language Pathology SC Acoustics; Audiology & Speech-Language Pathology GA FL775 UT WOS:A1991FL77500026 ER PT J AU DONG, X JAHANMIR, S HSU, SM AF DONG, X JAHANMIR, S HSU, SM TI TRIBOLOGICAL CHARACTERISTICS OF ALPHA-ALUMINA AT ELEVATED-TEMPERATURES SO JOURNAL OF THE AMERICAN CERAMIC SOCIETY LA English DT Article DE TRIBOLOGY; ALUMINA; HIGH TEMPERATURE; LOAD; WEAR ID SILICON-NITRIDE; WEAR; CERAMICS; FRICTION AB The tribological characteristics of a high-purity alpha-alumina sliding on a similar material under unlubricated conditions are divided into four distinct regimes. At low temperatures, T < 200-degrees-C, tribochemical reactions between the alumina surface and water vapor in the environment control the tribological performance. The coefficient of friction in this temperature range is approximately 0.40 and the wear coefficient is less than 10(-6), independent of contact load. At intermediate temperatures, 200-degrees-C < T < 800-degrees-C, the wear behavior depends on the contact load. At low loads, wear occurs by plastic flow and plowing; the coefficient of friction is approximately 0.60 and the wear coefficient is less than 10(-6). At loads larger than a threshold value, severe wear occurs by intergranular fracture. The coefficient of friction increases to 0.85 and the wear coefficient increases to a value greater than 10(-4). At temperatures above 800-degrees-C, formation of a silicon-rich layer on the wear track by diffusion and viscous flow of the grain-boundary phase reduces the coefficient of friction to 0.40, and the wear coefficient is reduced to a value less than 10(-6). The results of the wear tests and observations of the fundamental mechanisms controlling the tribological behavior of this material are consolidated in a simple wear transition diagram. RP DONG, X (reprint author), NATL INST STAND & TECHNOL,DIV CERAM,GAITHERSBURG,MD 20899, USA. NR 28 TC 98 Z9 103 U1 1 U2 10 PU AMER CERAMIC SOC PI WESTERVILLE PA 735 CERAMIC PLACE, PO BOX 6136, WESTERVILLE, OH 43081-6136 SN 0002-7820 J9 J AM CERAM SOC JI J. Am. Ceram. Soc. PD MAY PY 1991 VL 74 IS 5 BP 1036 EP 1044 DI 10.1111/j.1151-2916.1991.tb04340.x PG 9 WC Materials Science, Ceramics SC Materials Science GA FL762 UT WOS:A1991FL76200021 ER PT J AU KOGAN, YL AF KOGAN, YL TI THE SIMULATION OF A CONVECTIVE CLOUD IN A 3-D MODEL WITH EXPLICIT MICROPHYSICS .1. MODEL DESCRIPTION AND SENSITIVITY EXPERIMENTS SO JOURNAL OF THE ATMOSPHERIC SCIENCES LA English DT Article ID SIZE DISTRIBUTION; DROPLET SPECTRA; DIFFUSIVE MODEL; COALESCENCE; CONDENSATION; RAINDROPS; BREAKUP; GROWTH; EVOLUTION; ENTRAINMENT AB A three-dimensional nonhydrostatic anelastic numerical model of a convective cloud with an explicit description of microphysical processes has been developed. Two distribution functions are considered in the model-one for cloud condensation nuclei (19 categories from 0.0076 to 7.6 microns) and another for cloud droplets and raindrops (30 categories on a logarithmic scale from 4 to 3250 microns). The prognostic kinetic equations for these distribution functions enable the calculation of the aerosol and drop spectra starting from activation and culminating in rain formation. The warm rain microphysical processes studied include nucleation, condensation/evaporation, coalescence, breakup and sedimentation. Analysis of supersaturation evolution with time shows that it does not experience growth with the onset of coalescence and correlates well with values derived from quasi-steady assumptions. Sensitivity tests of the accuracy of the supersaturation calculations and the effect of the salt factor in the condensation calculations are also presented. To demonstrate the model's potential the results of a numerical experiment showing the evolution of a multicellular cloud are described briefly. They reveal such interesting features as vortex formation through merger of updrafts from cells of different intensity, interaction of the cloud with a stable environment, and repeated reentrainment into the cloud of the same air masses that circulate along spiral trajectories near cloud boundaries. C1 NATL SEVERE STORMS LAB,NORMAN,OK 73069. RP KOGAN, YL (reprint author), UNIV OKLAHOMA,COOPERAT INST MESOSCALE METEOROL STUDIES,401 E BOYD,NORMAN,OK 73019, USA. NR 63 TC 164 Z9 168 U1 0 U2 8 PU AMER METEOROLOGICAL SOC PI BOSTON PA 45 BEACON ST, BOSTON, MA 02108-3693 SN 0022-4928 J9 J ATMOS SCI JI J. Atmos. Sci. PD MAY 1 PY 1991 VL 48 IS 9 BP 1160 EP 1189 DI 10.1175/1520-0469(1991)048<1160:TSOACC>2.0.CO;2 PG 30 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA FM205 UT WOS:A1991FM20500003 ER PT J AU WILLOUGHBY, HE AF WILLOUGHBY, HE TI GRADIENT BALANCE IN TROPICAL CYCLONES - REPLY SO JOURNAL OF THE ATMOSPHERIC SCIENCES LA English DT Letter ID HURRICANES RP WILLOUGHBY, HE (reprint author), NOAA,AOML,DIV HURRICANE RES,4301 RICKENBACKER CAUSEWAY,MIAMI,FL 33149, USA. NR 7 TC 16 Z9 16 U1 0 U2 3 PU AMER METEOROLOGICAL SOC PI BOSTON PA 45 BEACON ST, BOSTON, MA 02108-3693 SN 0022-4928 J9 J ATMOS SCI JI J. Atmos. Sci. PD MAY 1 PY 1991 VL 48 IS 9 BP 1209 EP 1212 DI 10.1175/1520-0469(1991)048<1209:R>2.0.CO;2 PG 4 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA FM205 UT WOS:A1991FM20500007 ER PT J AU SUGAR, J KAUFMAN, V ROWAN, WL AF SUGAR, J KAUFMAN, V ROWAN, WL TI EXTREME-ULTRAVIOLET SPECTRA OF PD, AG, CD, AND SN IONS OBSERVED IN A 1.3-KEV TOKAMAK PLASMA SO JOURNAL OF THE OPTICAL SOCIETY OF AMERICA B-OPTICAL PHYSICS LA English DT Article ID MAGNETIC DIPOLE LINES; MOLYBDENUM; COPPER; CONFIGURATIONS; TRANSITIONS; WAVELENGTHS; MO; CU AB The elements Pd, Ag, Cd, and Sn were each injected by laser ablation into a tokamak plasma of 1.3-keV electron temperature. Spectra in the range of 50-400 angstrom were observed photographically with a 2.2-m grazing-incidence spectrograph. We identified lines in the isoelectronic sequences of S, Cl, Ar, and K that were not previously classified. They fall in the range of 51-78 angstrom and were measured with an uncertainty of 0.010 angstrom. Graphs of the differences between the measured and the calculated transition energies vary smoothly and confirm the identifications. Least-squares fits to these differences permit accurate predictions for elements Tc, Ru, Rh, and In that have not been investigated. Similar fits to ground-state doublet splittings in the Cl and K sequences provide accurate values of magnetic dipole transition energies for these ions. C1 UNIV TEXAS,FUS RES CTR,AUSTIN,TX 78712. RP SUGAR, J (reprint author), NATL INST STAND & TECHNOL,GAITHERSBURG,MD 20899, USA. NR 14 TC 6 Z9 6 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 MAY PY 1991 VL 8 IS 5 BP 913 EP 917 DI 10.1364/JOSAB.8.000913 PG 5 WC Optics SC Optics GA FL116 UT WOS:A1991FL11600001 ER PT J AU SESKO, DW WALKER, TG WIEMAN, CE AF SESKO, DW WALKER, TG WIEMAN, CE TI BEHAVIOR OF NEUTRAL ATOMS IN A SPONTANEOUS FORCE TRAP SO JOURNAL OF THE OPTICAL SOCIETY OF AMERICA B-OPTICAL PHYSICS LA English DT Article ID RADIATION PRESSURE; RESONANCE; LOSSES AB A classical collective behavior is observed in the spatial distributions of a cloud of optically trapped neutral atoms. They include extended uniform-density ellipsoids, rings of atoms around a small central ball, and clumps of atoms orbiting a central core. The distributions depend sensitively on the number of atoms and the alignment of the laser beams. Abrupt bistable transitions between different distributions are seen. This system is studied in detail, and much of this behavior can be explained by the incorporation of long-range interactions between the atoms in the equation of equilibrium. It is shown how attenuation and multiple scattering of the incident photons lead to these interactions. C1 UNIV COLORADO,DEPT PHYS,BOULDER,CO 80309. RP SESKO, DW (reprint author), UNIV COLORADO,NATL INST STAND & TECHNOL,JOINT INST LAB ASTROPHYS,BOULDER,CO 80309, USA. RI Walker, Thad/N-5590-2014 OI Walker, Thad/0000-0002-0996-3351 NR 16 TC 209 Z9 210 U1 2 U2 14 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 MAY PY 1991 VL 8 IS 5 BP 946 EP 958 DI 10.1364/JOSAB.8.000946 PG 13 WC Optics SC Optics GA FL116 UT WOS:A1991FL11600006 ER PT J AU BENNETT, J SIMONS, D AF BENNETT, J SIMONS, D TI RELATIVE SENSITIVITY FACTORS AND USEFUL YIELDS FOR A MICROFOCUSED GALLIUM ION-BEAM AND TIME-OF-FLIGHT SECONDARY ION MASS-SPECTROMETER SO JOURNAL OF VACUUM SCIENCE & TECHNOLOGY A-VACUUM SURFACES AND FILMS LA English DT Article; Proceedings Paper CT 37TH NATIONAL SYMP OF THE AMERICAN VACUUM SOC CY OCT 08-12, 1990 CL TORONTO, CANADA SP AMER VACUUM SOC AB Relative sensitivity factors for several elements in micrometer size glass particles, bulk glasses and glass thin films have been determined for a Ga+ liquid metal ion gun combined with a time-of-flight secondary ion mass spectrometer. The reproducibility of the values within and among glasses of various compositions is better than 20%. Reproducibility is improved by sputter cleaning the sample prior to data collection. Relative sensitivity factors have been obtained from bulk glasses using pulsed, low-energy electrons to neutralize charge buildup on the sample. Useful yields for Mg and Ca in a thin glass film were calculated to be 3.4 x 10(-4) and 8.0 x 10(-4), respectively. RP BENNETT, J (reprint author), NATL INST STAND & TECHNOL,DIV SURFACE & MICROANAL SCI,GAITHERSBURG,MD 20899, USA. NR 12 TC 4 Z9 4 U1 0 U2 3 PU AMER INST PHYSICS PI WOODBURY PA CIRCULATION FULFILLMENT DIV, 500 SUNNYSIDE BLVD, WOODBURY, NY 11797-2999 SN 0734-2101 J9 J VAC SCI TECHNOL A JI J. Vac. Sci. Technol. A-Vac. Surf. Films PD MAY-JUN PY 1991 VL 9 IS 3 BP 1379 EP 1384 DI 10.1116/1.577631 PN 2 PG 6 WC Materials Science, Coatings & Films; Physics, Applied SC Materials Science; Physics GA FR763 UT WOS:A1991FR76300029 ER PT J AU RICHTER, M WOICIK, JC PIANETTA, P MIYANO, KE KENDELEWICZ, T BOULDIN, CE SPICER, WE LINDAU, I AF RICHTER, M WOICIK, JC PIANETTA, P MIYANO, KE KENDELEWICZ, T BOULDIN, CE SPICER, WE LINDAU, I TI SURFACE EXTENDED X-RAY ADSORPTION FINE-STRUCTURE STUDIES OF THE SI(001) 2X1-SB INTERFACE SO JOURNAL OF VACUUM SCIENCE & TECHNOLOGY A-VACUUM SURFACES AND FILMS LA English DT Article; Proceedings Paper CT 37TH NATIONAL SYMP OF THE AMERICAN VACUUM SOC CY OCT 08-12, 1990 CL TORONTO, CANADA SP AMER VACUUM SOC ID MICROSCOPY; SI(100) AB Surface extended x-ray adsorption fine structure (SEXAFS) has been used to investigate the structure of Sb on the Si(001) 2 x 1 surface. The coverage of Sb which remains after annealing thick layers at 375-degrees-C, previously reported to be one monolayer (ML), is found in this work to form a disordered overlayer with three dimensional Sb clusters. This finding is concluded from the Sb L3 absorption spectra which are similar for this coverage to that of bulk Sb. After a 550-degrees-C anneal, Auger electron spectroscopy, and scanning tunneling microscopy (STM) show that about 1 ML of Sb remains. Phase and amplitude analysis of the Sb L3 edge SEXAFS shows that the remaining Sb atoms occupy a modified bridge site with a Si-Sb bond length of 2.63 +/- 0.04 angstrom. The Sb atoms form dimers with a Sb-Sb bond length of 2.91 +/- 0.04 angstrom, which is almost identical to the bulk Sb-Sb bond length of 2.90 angstrom. The Sb atoms lie 1.74 +/- 0.06 angstrom above the Si(001) surface. STM confirms the dimer structure of the Sb overlayer. C1 NATL INST STAND & TECHNOL,GAITHERSBURG,MD 20899. STANFORD UNIV,ELECTR LAB,STANFORD,CA 94305. RP RICHTER, M (reprint author), STANFORD UNIV,SYNCHROTRON RADIAT LAB,STANFORD,CA 94309, USA. NR 12 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 0734-2101 J9 J VAC SCI TECHNOL A JI J. Vac. Sci. Technol. A-Vac. Surf. Films PD MAY-JUN PY 1991 VL 9 IS 3 BP 1951 EP 1955 DI 10.1116/1.577433 PN 2 PG 5 WC Materials Science, Coatings & Films; Physics, Applied SC Materials Science; Physics GA FR763 UT WOS:A1991FR76300132 ER PT J AU WOICIK, JC KENDELEWICZ, T MIYANO, KE BOULDIN, CE MEISSNER, PL PIANETTA, P SPICER, WE AF WOICIK, JC KENDELEWICZ, T MIYANO, KE BOULDIN, CE MEISSNER, PL PIANETTA, P SPICER, WE TI STRUCTURE OF THE SI(111) SQUARE-ROOT-OF-3 X SQUARE-ROOT-OF-3-SB INTERFACE BY SURFACE X-RAY ABSORPTION FINE-STRUCTURE AND PHOTOEMISSION SO JOURNAL OF VACUUM SCIENCE & TECHNOLOGY A-VACUUM SURFACES AND FILMS LA English DT Article; Proceedings Paper CT 37TH NATIONAL SYMP OF THE AMERICAN VACUUM SOC CY OCT 08-12, 1990 CL TORONTO, CANADA SP AMER VACUUM SOC ID SPECTROSCOPY; AMPLITUDE; SHIFTS; PHASE; SI AB The combined techniques of surface extended x-ray absorption fine structure (SEXAFS) and high resolution core level photoelectron spectroscopy have been used to investigate the local bonding structure of the Sb/Si(111) interface. We find that the adsorption of 1 monolayer (ML) of Sb completely eliminates the surface components of the Si 2p core level spectrum. The Sb induced Si 2p interfacial core level has been found to be shifted 0.20 +/- 0.02 eV toward higher binding energy with an intensity that corresponds to the top 1 ML of surface atoms. The SEXAFS determination of the absolute surface coordination numbers and bond lengths within the first Sb shell is 2.1 +/- 0.3 Sb atoms at 2.86 +/- 0.02 angstrom and 2.0 +/- 0.4 Si atoms at 2.66 +/- 0.03 angstrom. Together, these results indicate that Sb trimers occupy the three fold atop sites of the Si(111) surface where each Sb atom is bonded to two Si atoms in a modified bridge configuration. C1 STANFORD UNIV,STANFORD ELECTR LABS,STANFORD,CA 94305. RP WOICIK, JC (reprint author), NATL INST STANDARDS & TECHNOL,GAITHERSBURG,MD 20899, USA. NR 24 TC 4 Z9 4 U1 0 U2 0 PU AMER INST PHYSICS PI WOODBURY PA CIRCULATION FULFILLMENT DIV, 500 SUNNYSIDE BLVD, WOODBURY, NY 11797-2999 SN 0734-2101 J9 J VAC SCI TECHNOL A JI J. Vac. Sci. Technol. A-Vac. Surf. Films PD MAY-JUN PY 1991 VL 9 IS 3 BP 1956 EP 1961 DI 10.1116/1.577435 PN 2 PG 6 WC Materials Science, Coatings & Films; Physics, Applied SC Materials Science; Physics GA FR763 UT WOS:A1991FR76300133 ER PT J AU DEAN, BE JOHNSON, CJ MCDEVITT, SC NEUGEBAUER, GT SEPICH, JL DOBBYN, RC KURIYAMA, M ELLSWORTH, J VYDYANATH, HR KENNEDY, JJ AF DEAN, BE JOHNSON, CJ MCDEVITT, SC NEUGEBAUER, GT SEPICH, JL DOBBYN, RC KURIYAMA, M ELLSWORTH, J VYDYANATH, HR KENNEDY, JJ TI CORRELATION OF HGCDTE EPILAYER DEFECTS WITH UNDERLYING SUBSTRATE DEFECTS BY SYNCHROTRON X-RAY TOPOGRAPHY SO JOURNAL OF VACUUM SCIENCE & TECHNOLOGY B LA English DT Article; Proceedings Paper CT 1990 US WORKSHOP ON THE PHYSICS AND CHEMISTRY OF MERCURY CADMIUM TELLURIDE AND NOVEL INFRARED DETECTOR MATERIALS CY OCT 02-04, 1990 CL SAN FRANCISCO, CA SP COMMUNICAT ELECTRON COMMAND CTR NIGHT VIS & ELECTRO OPT, USN, OFF NAVAL TECHNOL, ASAF, OFF SCI RES, AMER VACUUM SOC ID DIFFRACTION IMAGING TOPOGRAPHY; GROWTH; RADIATION AB Synchrotron x-ray topography studies have been conducted at the National Synchhrotron Light Source at Brookhaven National Laboratory to correlate defects in HcCdTe epilayers with those in underlying CdTe family substrates. Infrared detectors have been fabricated on these epilayers to investigate the performance impact of specific defects. This paper describes synchrotron x-ray facilities and methods. Images of substrates and epilayer are discussed and mapping of epolayer/substrate defects, such as microtwins, subgrain boundaries and slip lines, is demonstrated. Efforts to map detector array performance to epilayer and substrate topographs are described. C1 NATL INST STAND & TECHNOL,GAITHERSBURG,MD 20899. AEROJET ELECTROSYST CO,AZUSA,CA 91702. USA,CECOM,CNVEO,FT BELVOIR,VA 22060. RP DEAN, BE (reprint author), II-VI INC,SAXONBURG,PA 16056, USA. NR 14 TC 5 Z9 5 U1 0 U2 0 PU AMER INST PHYSICS PI WOODBURY PA CIRCULATION FULFILLMENT DIV, 500 SUNNYSIDE BLVD, WOODBURY, NY 11797-2999 SN 1071-1023 J9 J VAC SCI TECHNOL B JI J. Vac. Sci. Technol. B PD MAY-JUN PY 1991 VL 9 IS 3 BP 1840 EP 1846 DI 10.1116/1.585809 PG 7 WC Engineering, Electrical & Electronic; Nanoscience & Nanotechnology; Physics, Applied SC Engineering; Science & Technology - Other Topics; Physics GA FR866 UT WOS:A1991FR86600072 ER PT J AU SEILER, DG LOWNEY, JR LITTLER, CL YOON, IT LOLOEE, MR AF SEILER, DG LOWNEY, JR LITTLER, CL YOON, IT LOLOEE, MR TI PHOTOEXCITED HOT-ELECTRON RELAXATION PROCESSES IN N-HGCDTE THROUGH IMPACT IONIZATION INTO TRAPS SO JOURNAL OF VACUUM SCIENCE & TECHNOLOGY B LA English DT Article; Proceedings Paper CT 1990 US WORKSHOP ON THE PHYSICS AND CHEMISTRY OF MERCURY CADMIUM TELLURIDE AND NOVEL INFRARED DETECTOR MATERIALS CY OCT 02-04, 1990 CL SAN FRANCISCO, CA SP COMMUNICAT ELECTRON COMMAND CTR NIGHT VIS & ELECTRO OPT, USN, OFF NAVAL TECHNOL, ASAF, OFF SCI RES, AMER VACUUM SOC ID SPECTROSCOPY; IMPURITY AB In this article we report on a new type of spectroscopy for impurity and/or defect levels in the energy gap of narrow-gap semiconductors using the near-band-gap photon energies from a laser. This spectroscopy is done under the conditions of intense laser photoexcitation and is associated with the Auger relaxation processes of hot electrons involving impact ionization of valence electrons into impurity of defect levels. Wavelength-independent structure in the photoconductive response versus magnetic field is observed at high intensities in samples of Hg1-xCd(x)Te with x almost-equal-to 0.22 and 0.24. This structure arises from hot electrons photoexcited high into the conduction band by sequential absorption of CO2 laser radiation. The hot electrons lose their energy by impact ionizing valence electrons into impurity/defect levels in the gap. For the sample with x almost-equal-to 0.22 and an energy gap of 95 meV, three levels are found at 15, 45, and 59 meV above the valence band. A level at 61 meV is found for the sample with x almost-equal-to 0.24 and a gap of 122 meV. C1 N TEXAS STATE UNIV,TEXAS COLL OSTEOPATH MED,DEPT PHYS,DENTON,TX 76203. RP SEILER, DG (reprint author), NATL INST STAND & TECHNOL,DIV SEMICOND ELECTR,GAITHERSBURG,MD 20899, USA. NR 5 TC 5 Z9 5 U1 0 U2 1 PU AMER INST PHYSICS PI WOODBURY PA CIRCULATION FULFILLMENT DIV, 500 SUNNYSIDE BLVD, WOODBURY, NY 11797-2999 SN 1071-1023 J9 J VAC SCI TECHNOL B JI J. Vac. Sci. Technol. B PD MAY-JUN PY 1991 VL 9 IS 3 BP 1847 EP 1851 DI 10.1116/1.585810 PG 5 WC Engineering, Electrical & Electronic; Nanoscience & Nanotechnology; Physics, Applied SC Engineering; Science & Technology - Other Topics; Physics GA FR866 UT WOS:A1991FR86600073 ER PT J AU BARNEA, G NAVON, E GINZBURG, A POLITCH, J ROEHRIG, H DICK, CE PLACIOUS, RC AF BARNEA, G NAVON, E GINZBURG, A POLITCH, J ROEHRIG, H DICK, CE PLACIOUS, RC TI USE OF STORAGE PHOSPHOR IMAGING PLATES IN PORTAL IMAGING AND HIGH-ENERGY RADIOGRAPHY - THE INTENSIFYING EFFECT OF METALLIC SCREENS ON THE SENSITIVITY SO MEDICAL PHYSICS LA English DT Article DE STORAGE PHOSPHOR IMAGING PLATES; SENSITIVITY; METAL SCREENS; MEGAVOLT PHOTON ENERGIES; MONTE-CARLO; ABSORBED DOSE ID LASER STIMULATED LUMINESCENCE; PERFORMANCE; PHOTONS; SYSTEM; FILMS AB The sensitivity of storage phosphor imaging plates (SPIP) at megavolt photon energies (Co-60, 6-, 10-, and 18-MV radiotherapy beams) is studied both experimentally and by Monte Carlo radiation transport calculations. In addition, the same techniques are used to investigate the intensifying effect of metal screens on the sensitivity of the SPIP. The results provide evidence that the sensitivity of the SPIPs is proportional to the absorbed energy in the phosphor layer per cGy. The spectral sensitivity is calculated for photon energies between 10 keV and 20 MeV for various SPIP-screen combinations. C1 UNIV ARIZONA,DEPT RADIOL,TUCSON,AZ 85721. UNIV ARIZONA,CTR OPT SCI,TUCSON,AZ 85721. NATL INST STANDARDS & TECHNOL,CTR RADIAT RES,GAITHERSBURG,MD 20899. RP BARNEA, G (reprint author), RAFAEL,POB 2250,HAIFA,ISRAEL. NR 21 TC 12 Z9 12 U1 1 U2 1 PU AMER INST PHYSICS PI WOODBURY PA CIRCULATION FULFILLMENT DIV, 500 SUNNYSIDE BLVD, WOODBURY, NY 11797-2999 SN 0094-2405 J9 MED PHYS JI Med. Phys. PD MAY-JUN PY 1991 VL 18 IS 3 BP 432 EP 438 DI 10.1118/1.596690 PG 7 WC Radiology, Nuclear Medicine & Medical Imaging SC Radiology, Nuclear Medicine & Medical Imaging GA FR130 UT WOS:A1991FR13000014 PM 1870486 ER PT J AU WEISS, M WEISSERT, T AF WEISS, M WEISSERT, T TI AT2, A NEW TIME SCALE ALGORITHM - AT1 PLUS FREQUENCY VARIANCE SO METROLOGIA LA English DT Article ID CLOCKS AB The existing AT1 algorithm produces a time scale with a fractional frequency variation smaller than that of any clock in the ensemble. We are developing a modification to AT1 that includes the additional desirable features: automatic frequency-step detection, the option to run in an optimal post-processing mode and to run with minimal supervision in non-technical environments. These properties are facilitated by the inclusion of a Kalman-filter estimate of the frequency variance of each clock in the scale. Results are reported from both simulated and real clock data to demonstrate automatic frequency-step detection. C1 NATL INST STAND & TECHNOL,DIV TIME & FREQUENCY,BOULDER,CO 80303. NR 8 TC 24 Z9 26 U1 0 U2 2 PU BUREAU INT POIDS MESURES PI SEVRES CEDEX PA B1 PM PAVILLION DE BRETUEIL, F-92312 SEVRES CEDEX, FRANCE SN 0026-1394 J9 METROLOGIA JI Metrologia PD MAY PY 1991 VL 28 IS 2 BP 65 EP 74 DI 10.1088/0026-1394/28/2/002 PG 10 WC Instruments & Instrumentation; Physics, Applied SC Instruments & Instrumentation; Physics GA JB183 UT WOS:A1991JB18300002 ER PT J AU BIRNBAUM, G BORYSOW, A AF BIRNBAUM, G BORYSOW, A TI ON THE PROBLEM OF DETAILED BALANCE AND MODEL LINESHAPES IN COLLISION-INDUCED ROTOVIBRATIONAL BANDS - H2-H2 AND H2-HE SO MOLECULAR PHYSICS LA English DT Article ID INDUCED ABSORPTION; H-2-HE PAIRS; NONPOLAR GASES; SPECTRA AB When account is taken of the vibrational dependence of the potential function, the usual condition of detailed balance taken with respect to the vibrational-rotational frequencies does not apply, and model spectral functions satisfying this condition are inaccurate. A model correlation function is derived that deals with the case of vibration-dependent potentials. The parameters of the model are computed from relations involving the spectral moments. This model is shown to give spectral shapes, for a number of examples involving the fundamental and first overtone bands of H-2-He and H-2-H-2 at room temperature and 1000 K, in excellent agreement with spectra calculated quantum mechanically from first principles. The model is useful for predicting the collision-induced vibrational spectra for these and other systems for which the vibration-dependent induced dipole and potential are known. C1 MICHIGAN TECHNOL UNIV,DEPT PHYS,HOUGHTON,MI 49931. RP BIRNBAUM, G (reprint author), NATL INST STAND & TECHNOL,MAT SCI & ENGN LAB,GAITHERSBURG,MD 20899, USA. NR 19 TC 9 Z9 9 U1 0 U2 1 PU TAYLOR & FRANCIS LTD PI LONDON PA ONE GUNDPOWDER SQUARE, LONDON, ENGLAND EC4A 3DE SN 0026-8976 J9 MOL PHYS JI Mol. Phys. PD MAY PY 1991 VL 73 IS 1 BP 57 EP 68 DI 10.1080/00268979100101051 PG 12 WC Chemistry, Physical; Physics, Atomic, Molecular & Chemical SC Chemistry; Physics GA FR876 UT WOS:A1991FR87600005 ER PT J AU PARSONS, DB SHAPIRO, MA HARDESTY, RM ZAMORA, RJ INTRIERI, JM AF PARSONS, DB SHAPIRO, MA HARDESTY, RM ZAMORA, RJ INTRIERI, JM TI THE FINESCALE STRUCTURE OF A WEST TEXAS DRYLINE SO MONTHLY WEATHER REVIEW LA English DT Article ID PLANETARY BOUNDARY-LAYER; SEVERE STORM ENVIRONMENT; DOPPLER RADAR DATA; OKLAHOMA DRYLINE; BUOYANCY; MOTION; PRECIPITATION; TROPOSPHERE; TOPOGRAPHY; MICROBURST AB During spring and early summer, a surface confluence zone, often referred to as the dryline, forms in the midwestern United States between continental and maritime air masses. The dewpoint temperature across the dryline can vary in excess of 18-degrees-C in a distance of less than 10 km. The movement of the dryline varies diurnally with boundary layer growth over sloping terrain leading to an eastward apparent propagation of the dryline during the day and a westward advection or retrogression during the evening. In this study, we examine the finescale structure of a retrogressing dryline using data taken by a Doppler lidar, a dual-channel radiometer, and serial rawinsonde ascents. While many previous studies were unable to accurately measure the vertical motions in the vicinity of the dryline, our lidar measurements suggest that the convergence at the dryline is intense with maximum vertical motions of approximately 5 m s-1. The winds obtained from the Doppler lidar measurements were combined with the equations of motion to derive perturbation fields of pressure and virtual potential temperature theta-v. Our observations indicate that the circulations associated with this retrogressing dryline were dominated by hot, dry air riding over a westward moving denser, moist flow in a manner similar to a density current. Gravity waves were observed above the dryline interface. Previous observational and numerical studies have shown that differential heating across the dryline may sometimes enhance regional pressure gradients and thus impact dryline movement. We propose that this regional gradient in surface heating in the presence of a confluent flow results in observed intense wind shifts and large horizontal gradients in theta-v across the dryline. The local gradient in theta-v influences the movement and flow characteristics of the dryline interface. This study is one of the most complete and novel uses of Doppler lidar to date. C1 NOAA,ENVIRONM RES LAB,ZENTRUM WAVE PROPAGAT,BOULDER,CO 80303. UNIV COLORADO,NOAA,COOPERAT INST RES ENVIRONM SCI,BOULDER,CO 80309. RP PARSONS, DB (reprint author), NATL CTR ATMOSPHER RES,MESOSCALE PREDICT SECT,POB 3000,BOULDER,CO 80307, USA. RI Hardesty, Robert/H-9844-2013; Intrieri, Janet/D-5608-2015 NR 42 TC 50 Z9 51 U1 0 U2 3 PU AMER METEOROLOGICAL SOC PI BOSTON PA 45 BEACON ST, BOSTON, MA 02108-3693 SN 0027-0644 J9 MON WEATHER REV JI Mon. Weather Rev. PD MAY PY 1991 VL 119 IS 5 BP 1242 EP 1258 DI 10.1175/1520-0493(1991)119<1242:TFSOAW>2.0.CO;2 PG 17 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA FM548 UT WOS:A1991FM54800008 ER PT J AU SZOKE, EJ AF SZOKE, EJ TI EYE OF THE DENVER CYCLONE SO MONTHLY WEATHER REVIEW LA English DT Article ID PAST 3-DIMENSIONAL OBSTACLES; FLOW; VORTICES AB Observation of an overcast of low cloudiness on a Denver Cyclone day revealed a circular area of clearing or "eye" at the approximate center of the mesoscale circulation. The eye passed close to an automated observing station, providing a time series of data that shows the relationship of the circulation to the cloud-free area. Conditions present in the lower troposphere are examined and compared to conclusions from recent modeling results that suggest the causes of the Denver Cyclone. C1 NOAA,ENVIRONM RES LAB,FORECAST SYST LAB,BOULDER,CO 80303. RI Szoke, Edward/K-1477-2015 OI Szoke, Edward/0000-0001-9524-7193 NR 12 TC 14 Z9 14 U1 0 U2 4 PU AMER METEOROLOGICAL SOC PI BOSTON PA 45 BEACON ST, BOSTON, MA 02108-3693 SN 0027-0644 J9 MON WEATHER REV JI Mon. Weather Rev. PD MAY PY 1991 VL 119 IS 5 BP 1283 EP 1292 DI 10.1175/1520-0493(1991)119<1283:EOTDC>2.0.CO;2 PG 10 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA FM548 UT WOS:A1991FM54800010 ER PT J AU LEVIN, JC BIEDERMANN, C KELLER, N LILJEBY, L SHORT, RT SELLIN, IA LINDLE, DW AF LEVIN, JC BIEDERMANN, C KELLER, N LILJEBY, L SHORT, RT SELLIN, IA LINDLE, DW TI PHOTOION AUGER-ELECTRON COINCIDENCE MEASUREMENTS NEAR THRESHOLD SO NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH SECTION B-BEAM INTERACTIONS WITH MATERIALS AND ATOMS LA English DT Article ID SYNCHROTRON RADIATION BEAMLINE; HIGH-ENERGY-RESOLUTION; PHOTOELECTRON RECAPTURE; ARGON; SATELLITES AB The vacancy cascade which fills an atomic inner-shell hole is a complex process which can proceed by a variety of paths, often resulting in a broad distribution of photoion charge states. We have measured simplified argon photoion charge distributions by requiring a coincidence with a F-LL or K-LM Auger electron, following K excitation with synchrotron radiation, as a function of photon energy, and report here in detail the argon charge distributions coincident with K-L1L23 Auger electrons. The distributions exhibit a much more pronounced photon-energy dependence than do the more complicated non-coincident spectra. Resonant excitation of the K electron to np levels, shakeoff of these np electrons by subsequent decay processes, double-Auger decay, and recapture of the K photoelectron through postcollision interaction occur with significant probability. C1 OAK RIDGE NATL LAB, OAK RIDGE, TN 37831 USA. NATL INST STAND & TECHNOL, GAITHERSBURG, MD 20899 USA. RP UNIV TENNESSEE, DEPT PHYS, KNOXVILLE, TN 37996 USA. NR 17 TC 8 Z9 8 U1 0 U2 0 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0168-583X EI 1872-9584 J9 NUCL INSTRUM METH B JI Nucl. Instrum. Methods Phys. Res. Sect. B-Beam Interact. Mater. Atoms PD MAY PY 1991 VL 56-7 BP 124 EP 128 DI 10.1016/0168-583X(91)95987-O PN 1 PG 5 WC Instruments & Instrumentation; Nuclear Science & Technology; Physics, Atomic, Molecular & Chemical; Physics, Nuclear SC Instruments & Instrumentation; Nuclear Science & Technology; Physics GA FQ888 UT WOS:A1991FQ88800036 ER PT J AU SOUTHWORTH, SH LINDLE, DW MAYER, R COWAN, PL AF SOUTHWORTH, SH LINDLE, DW MAYER, R COWAN, PL TI ANISOTROPY OF POLARIZED X-RAY-EMISSION FROM ATOMS AND MOLECULES SO NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH SECTION B-BEAM INTERACTIONS WITH MATERIALS AND ATOMS LA English DT Article ID SYNCHROTRON RADIATION BEAMLINE; HIGH-ENERGY-RESOLUTION; PERFORMANCE; ALIGNMENT AB Strongly anisotropic, polarized Cl K-beta X-ray emission has been observed from gas-phase CF3Cl following selective resonant excitation with a linearly polarized X-ray beam. Distinctively different polarizations and angular distributions result for emission involving molecular orbitals of different symmetries. A classical model of the X-ray absorption/emission process well describes the observed radiation patterns. A small anisotropy also was measured for Ar K-alpha emission following resonant excitation. The observation of only a small anisotropy in this case is attributed to the averaging out of the individual anisotropies from unresolved final states. We review the experimental methods and results and discuss theoretical models used to describe polarization and anisotropy effects in X-ray absorption and emission from atoms and molecules. RP SOUTHWORTH, SH (reprint author), NATL INST STAND & TECHNOL, GAITHERSBURG, MD 20899 USA. NR 17 TC 7 Z9 7 U1 0 U2 0 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0168-583X J9 NUCL INSTRUM METH B JI Nucl. Instrum. Methods Phys. Res. Sect. B-Beam Interact. Mater. Atoms PD MAY PY 1991 VL 56-7 BP 304 EP 308 DI 10.1016/0168-583X(91)96032-G PN 1 PG 5 WC Instruments & Instrumentation; Nuclear Science & Technology; Physics, Atomic, Molecular & Chemical; Physics, Nuclear SC Instruments & Instrumentation; Nuclear Science & Technology; Physics GA FQ888 UT WOS:A1991FQ88800081 ER PT J AU OBRIEN, WL JIA, J DONG, QY CALLCOTT, TA RUBENSSON, JE MUELLER, DL EDERER, DL AF OBRIEN, WL JIA, J DONG, QY CALLCOTT, TA RUBENSSON, JE MUELLER, DL EDERER, DL TI RESONANT ABSORPTION AND EMISSION FROM LOCALIZED CORE-HOLE STATES IN AL2O3 AND SIO2 SO NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH SECTION B-BEAM INTERACTIONS WITH MATERIALS AND ATOMS LA English DT Article; Proceedings Paper CT 11TH INTERNATIONAL CONF ON THE APPLICATION OF ACCELERATORS IN RESEARCH AND INDUSTRY CY NOV 05-08, 1990 CL DENTON, TX ID ELECTRONIC-STRUCTURE; PHONON RELAXATION; MO CALCULATIONS; ALUMINUM; SPECTRA; SILICON; COORDINATION; ALPHA-AL2O3; OXYGEN; REGION AB We have compared the Al L23 and Si L23 emission and reflection spectra of Al2O3 and SiO2 to obtain information on the nature of the excited states in the presence of the L23 holes. A 5 m Rowland spectrometer, using a 600 1/mm grating mounted in grazing incidence was used to detect both electron excited soft X-ray emission and near normal soft X-ray reflection. We report fine structure in the emission spectra above the L23 edges which coincides with structure in the reflection spectra. These features appear both in the bandgap and in the conduction band. Such features within the bandgap are typically identified as excitons, while those in the conduction band must be localized excited states. Therefore, measurements of epsilon-2, for SiO2 and Al2O3 above the L23 edge should be interpreted in terms of localized excitations in the presence of a core hole, rather than interband transitions. C1 UNIV TENNESSEE,KNOXVILLE,TN 37996. NATL INST STAND & TECHNOL,GAITHERSBURG,MD 20899. NR 25 TC 4 Z9 4 U1 0 U2 2 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0168-583X J9 NUCL INSTRUM METH B JI Nucl. Instrum. Methods Phys. Res. Sect. B-Beam Interact. Mater. Atoms PD MAY PY 1991 VL 56-7 BP 320 EP 323 DI 10.1016/0168-583X(91)96036-K PN 1 PG 4 WC Instruments & Instrumentation; Nuclear Science & Technology; Physics, Atomic, Molecular & Chemical; Physics, Nuclear SC Instruments & Instrumentation; Nuclear Science & Technology; Physics GA FQ888 UT WOS:A1991FQ88800085 ER PT J AU LINDLE, DW CRASEMANN, B AF LINDLE, DW CRASEMANN, B TI ATOMIC, MOLECULAR, AND OPTICAL PHYSICS WITH X-RAYS SO NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH SECTION B-BEAM INTERACTIONS WITH MATERIALS AND ATOMS LA English DT Article; Proceedings Paper CT 11TH INTERNATIONAL CONF ON THE APPLICATION OF ACCELERATORS IN RESEARCH AND INDUSTRY CY NOV 05-08, 1990 CL DENTON, TX ID SYNCHROTRON RADIATION BEAMLINE; HIGH-ENERGY-RESOLUTION; FLUORESCENCE; SPECTROSCOPY; AUGER; CU AB With the advent of third-generation synchrotron-radiation sources now being built, research in the area of atomic, molecular, and optical physics using X-rays from these insertion-device-based facilities is expected to experience a renaissance. Many of the most sought after experimental goals in this area of research will become possible or even routine. To highlight some of the exciting possibilities, some specific examples are discussed, such as the X-ray and Auger resonant-Raman effect and polarized molecular X-ray emission. Plans for implementation of an X-ray synchrotron-radiation beamline dedicated to atomic, molecular, and optical physics at the Advanced Light Source are presented, with emphasis on the enhanced capabilities that will be available at this state-of-the-art facility. C1 UNIV OREGON,DEPT PHYS,EUGENE,OR 97403. RP LINDLE, DW (reprint author), NATL INST STAND & TECHNOL,GAITHERSBURG,MD 20899, USA. NR 23 TC 2 Z9 2 U1 0 U2 1 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0168-583X J9 NUCL INSTRUM METH B JI Nucl. Instrum. Methods Phys. Res. Sect. B-Beam Interact. Mater. Atoms PD MAY PY 1991 VL 56-7 BP 441 EP 445 DI 10.1016/0168-583X(91)96066-T PN 1 PG 5 WC Instruments & Instrumentation; Nuclear Science & Technology; Physics, Atomic, Molecular & Chemical; Physics, Nuclear SC Instruments & Instrumentation; Nuclear Science & Technology; Physics GA FQ888 UT WOS:A1991FQ88800115 ER PT J AU OSTERBERG, U LAWCONNELL, RI LEITCH, JW AF OSTERBERG, U LAWCONNELL, RI LEITCH, JW TI RELATIVE MEASUREMENTS OF TENSOR COMPONENTS FOR INTRINSIC AND INDUCED 2ND-ORDER NONLINEAR SUSCEPTIBILITIES IN GLASS OPTICAL FIBERS SO OPTICS COMMUNICATIONS LA English DT Article ID PHOTOINDUCED 2ND-HARMONIC GENERATION AB We have measured the x and y components of both the intrinsic and induced second-order nonlinear susceptibilities in glass optical fibers. In addition, we have measured the angular dependence of the intrinsic and induced second-harmonic light intensity as a function of input polarization. Our results are discussed in relation to the models put forward to date to explain second-harmonic generation in optical fibers. C1 DARTMOUTH COLL,THAYER SCH ENGN,HANOVER,NH 03755. UNIV COLORADO,NATL INST STAND & TECHNOL,JOINT INST LAB ASTROPHYS,DEPT PHYS,BOULDER,CO 80302. RP OSTERBERG, U (reprint author), USAF ACAD,FJ SEILER RES LAB,COLORADO SPRINGS,CO 80840, USA. NR 18 TC 1 Z9 1 U1 0 U2 0 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0030-4018 J9 OPT COMMUN JI Opt. Commun. PD MAY 1 PY 1991 VL 82 IS 5-6 BP 549 EP 553 DI 10.1016/0030-4018(91)90378-Q PG 5 WC Optics SC Optics GA FM519 UT WOS:A1991FM51900028 ER PT J AU HANLEY, HJM STRATY, GC LINDNER, P AF HANLEY, HJM STRATY, GC LINDNER, P TI ORDER IN A SIMPLE COLLOIDAL MIXTURE SUSPENSION SO PHYSICA A LA English DT Article ID ANGLE NEUTRON-SCATTERING; CALCIUM-CARBONATE; SHEAR-FLOW; DISPERSIONS; SPHERES; SIMULATIONS AB Preliminary SANS (small angle neutron scattering) measurements from a well characterized binary colloidal suspension of 91 nm polystyrene latex and 54 nm silica particles in water are reported for the Q range 0.02 < Q (nm-1) < 0.12, where Q is the scattering wave vector. The polystyrene-to-silica number ratio was 1.7 to 1 and the mixture volume fraction phi = 0.15. Key measurements were the scattered intensity of the mixture, and the partial scattered intensities of the polystyrene and silica in the mixture. The partial scattered intensity of one species was obtained by contrast matching the other species in the appropriate mixture of H2O and D2O. Partial structure factors and pair distribution functions are compared with computer simulation data for a soft sphere mixture and with the hard sphere expressions of Ashcroft and Langreth. C1 NATL INST STAND & TECHNOL,DIV THERMOPHYS,BOULDER,CO 80303. INST MAX VON LAUE PAUL LANGEVIN,F-38042 GRENOBLE,FRANCE. RP HANLEY, HJM (reprint author), WISSENSCHAFTSKOLLEG BERLIN,O-1000 BERLIN 33,GERMANY. NR 30 TC 11 Z9 11 U1 0 U2 1 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0378-4371 J9 PHYSICA A JI Physica A PD MAY 1 PY 1991 VL 174 IS 1 BP 60 EP 73 DI 10.1016/0378-4371(91)90417-B PG 14 WC Physics, Multidisciplinary SC Physics GA FR364 UT WOS:A1991FR36400006 ER PT J AU SUGAR, J TRABERT, E MOLLER, G HECKMANN, PH BLANKE, JH MARTINSON, I AF SUGAR, J TRABERT, E MOLLER, G HECKMANN, PH BLANKE, JH MARTINSON, I TI BEAM-FOIL STUDY OF 2-ELECTRON TRANSITIONS IN CU-LIKE IONS SO PHYSICA SCRIPTA LA English DT Article ID ENERGY-LEVELS; MO-XIV; SPECTRUM; SPECTROMETER; XIII AB The transition 3d104p2P0-3d94s2 2D in Cu-like ions, the XUV laser transition proposed by Morley and Sugar, has now been identified in delayed spectra obtained with foil-excited ion beams of Nb, Mo and Ag. Calculations of the wavelenghts agree closely with the observations, but the observed decay times are significantly larger than the theoretically expected lifetimes. We show that the lifetime is probably obscured by long-lived cascades from the lowest-lying quartet levels. C1 HARVARD COLL OBSERV,CAMBRIDGE,MA 02138. RUHR UNIV BOCHUM,W-4630 BOCHUM 1,GERMANY. UNIV KASSEL,FACHBEREICH PHYS,W-3500 KASSEL,GERMANY. UNIV LUND,INST FYS,S-22362 LUND,SWEDEN. RP SUGAR, J (reprint author), NATL INST STAND & TECHNOL,GAITHERSBURG,MD 20899, USA. NR 26 TC 13 Z9 13 U1 0 U2 0 PU ROYAL SWEDISH ACAD SCIENCES PI STOCKHOLM PA PUBL DEPT BOX 50005, S-104 05 STOCKHOLM, SWEDEN SN 0281-1847 J9 PHYS SCRIPTA JI Phys. Scr. PD MAY PY 1991 VL 43 IS 5 BP 484 EP 489 DI 10.1088/0031-8949/43/5/009 PG 6 WC Physics, Multidisciplinary SC Physics GA FM455 UT WOS:A1991FM45500009 ER PT J AU GELTMAN, S AF GELTMAN, S TI MULTIPHOTON-DETACHMENT CROSS-SECTIONS FOR H- SO PHYSICAL REVIEW A LA English DT Article ID STRONG LASER FIELDS; 2-PHOTON DETACHMENT; ONE-PHOTON; MODEL; ELECTRON; ION AB Perturbation theory is applied to the evaluation of the multiphoton-detachment cross sections of H- in a number of approximations. The zero-range plane-wave approximation is the simplest, as its effective dipole matrix element is reducible to a recursive differentiation, and it is applied to the one-to seven-photon-detachment processes. Improvements on this are made in the bound state by means of a short-range potential model and a dynamic screening representation, and in the continuum wave functions with the use of the best previously calculated e-H(1s) singlet scattering phase shifts. The dynamic screening parameters are adjusted to give a good fit of the resulting one-photon cross section to its correct well-known value, and the accurate phase shifts effectively include all the important correlation effects in the free-free amplitudes. These improved wave functions are used for the evaluation of the two- and three-photon generalized detachment cross sections by explicitly carrying out all intermediate state sums. Our best sigma-2 and sigma-3 are estimated to be accurate to order 5%. The present theoretical results are compared with other calculations and recent measurements, revealing areas of agreement as well as certain discrepancies. RP GELTMAN, S (reprint author), UNIV COLORADO,NATL INST STAND & TECHNOL,JOINT INST LAB ASTROPHYS,BOULDER,CO 80302, USA. NR 40 TC 39 Z9 39 U1 0 U2 0 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 1050-2947 J9 PHYS REV A JI Phys. Rev. A PD MAY 1 PY 1991 VL 43 IS 9 BP 4930 EP 4940 DI 10.1103/PhysRevA.43.4930 PG 11 WC Optics; Physics, Atomic, Molecular & Chemical SC Optics; Physics GA FL111 UT WOS:A1991FL11100040 ER PT J AU ITANO, WM HEINZEN, DJ BOLLINGER, JJ WINELAND, DJ AF ITANO, WM HEINZEN, DJ BOLLINGER, JJ WINELAND, DJ TI QUANTUM ZENO EFFECT - REPLY SO PHYSICAL REVIEW A LA English DT Letter ID FLUORESCENCE; COLLAPSE AB Various interpretations of quantum mechanics are valid insofar as they predict the same experimental results. Some invoke "wave-function collapse" and some do not. An interpretation based on the collapse postulate provides a simple explanation for a recent experimental demonstration of the quantum Zeno effect [Itano et al., Phys. Rev. A 41, 2295 (1990)], but other interpretations are also valid. RP ITANO, WM (reprint author), NATL INST STAND & TECHNOL,DIV TIME & FREQUENCY,BOULDER,CO 80303, USA. NR 7 TC 61 Z9 61 U1 0 U2 5 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 1050-2947 J9 PHYS REV A JI Phys. Rev. A PD MAY 1 PY 1991 VL 43 IS 9 BP 5168 EP 5169 DI 10.1103/PhysRevA.43.5168 PG 2 WC Optics; Physics, Atomic, Molecular & Chemical SC Optics; Physics GA FL111 UT WOS:A1991FL11100073 ER PT J AU WALSH, T MORELAND, J ONO, RH KALKUR, TS AF WALSH, T MORELAND, J ONO, RH KALKUR, TS TI BI-SR-CA-CU-O THIN-FILM ENERGY-GAP AS A FUNCTION OF TEMPERATURE AND FORCE APPLIED TO SQUEEZABLE-ELECTRON-TUNNELING JUNCTIONS SO PHYSICAL REVIEW B LA English DT Note ID SPECTROSCOPY AB Tunneling-spectroscopy measurements have been performed on Bi-Sr-Ca-Cu-O squeezable-electron-tunneling (SET) junctions. Two distinct features have been seen in the current-voltage [I(V)] and conductance-voltage [G(V)] characteristics. One of these features has the appearance of an energy-gap signature, while the other may be due to switching to the voltage state of a grain-boundary junction that is in series with the SET junction. The latter feature can mimic the energy-gap signature in I(V) and G(V) characteristics. These two features respond very differently to changes in temperature and the force applied to the SET junctions. C1 UNIV COLORADO,COLORADO SPRINGS,CO 80933. RP WALSH, T (reprint author), NATL INST STANDARDS & TECHNOL,BOULDER,CO 80303, USA. NR 14 TC 13 Z9 13 U1 0 U2 0 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 0163-1829 J9 PHYS REV B JI Phys. Rev. B PD MAY 1 PY 1991 VL 43 IS 13 BP 11492 EP 11495 DI 10.1103/PhysRevB.43.11492 PN B PG 4 WC Physics, Condensed Matter SC Physics GA FL041 UT WOS:A1991FL04100102 ER PT J AU SCHERBAUM, F GILLARD, D DEICHMANN, N AF SCHERBAUM, F GILLARD, D DEICHMANN, N TI SLOWNESS POWER SPECTRUM ANALYSIS OF THE CODA COMPOSITION OF 2 MICROEARTHQUAKE CLUSTERS IN NORTHERN SWITZERLAND SO PHYSICS OF THE EARTH AND PLANETARY INTERIORS LA English DT Article; Proceedings Paper CT SYMP AT THE 25TH GENERAL ASSEMBLY OF THE INTERNATIONAL ASSOC OF SEISMOLOGY AND PHYSICS OF EARTHS INTERIOR : SCATTERING AND ATTENUATION OF SEISMIC WAVES CY AUG 31-SEP 01, 1989 CL ISTANBUL, TURKEY SP INT ASSOC SEISMOL & PHYS EARTHS INTERIOR ID RANDOMLY INHOMOGENEOUS LITHOSPHERE; LOCAL EARTHQUAKES; WAVES; ATTENUATION; SCATTERING; SEISMOGRAMS AB The S-wave coda composition of two microearthquake clusters in northern Switzerland has been analysed using the slowness power spectrum analysis proposed by Spudich and Bostwick. The purpose of this paper is to estimate the directions in which individual coda wavelets leave the source region for lapse times more than six times the S-wave travel time. The data set consists of 12 and 16 events in the magnitude range of 1.9-2.6 and 1.4-3.4, respectively. The depths range from 7 to 8 km and from 6 to 7 km. Digital data from five vertical-component stations (ENB, RBF, GEF, GIF and TSB) and two three-component stations (ACB and CHE) were available. The hypocentral distances to the recording sites vary between 29 and 63 km for the first cluster (Gunsberg) and 10 and 24 km for the second cluster (Laufelfingen), respectively. All events have been relocated using a master event technique with inter-event arrival times estimated by a cross-correlation method. The slowness power spectra for the Laufelfingen cluster at all stations show essentially two different patterns. In agreement with the results of Spudich and Bostwick, we found that the early coda following the direct S wave immediately was composed of wavelets leaving the source region with the same slowness vector as the direct wave. We interpret this coda part as being very probably produced close to the recording site. However, with increasing lapse times we observe a different coda type which receives its energy from wavelets leaving the source region in a variety of directions. The transition between the two coda 'types' takes place often at 1.5-2 times and always before three times the S-wave arrival time. C1 UNIV COLORADO,NOAA,COOPERAT INST RES ENVIRONM SCI,BOULDER,CO 80309. SWISS FED INST TECHNOL,INST GEOPHYS,CH-8093 ZURICH,SWITZERLAND. RP SCHERBAUM, F (reprint author), UNIV MUNICH,INST ALLGEMEINE & ANGEW GEOPHYS,THERESIENSTR 41-IV,W-8000 MUNICH 2,GERMANY. RI Scherbaum, Frank/F-4144-2011 NR 27 TC 31 Z9 31 U1 0 U2 3 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0031-9201 J9 PHYS EARTH PLANET IN JI Phys. Earth Planet. Inter. PD MAY PY 1991 VL 67 IS 1-2 BP 137 EP 161 DI 10.1016/0031-9201(91)90067-R PG 25 WC Geochemistry & Geophysics SC Geochemistry & Geophysics GA FQ036 UT WOS:A1991FQ03600014 ER PT J AU BUSHNELL, PG BRILL, RW AF BUSHNELL, PG BRILL, RW TI RESPONSES OF SWIMMING SKIPJACK (KATSUWONUS-PELAMIS) AND YELLOWFIN (THUNNUS-ALBACARES) TUNAS TO ACUTE-HYPOXIA, AND A MODEL OF THEIR CARDIORESPIRATORY FUNCTION SO PHYSIOLOGICAL ZOOLOGY LA English DT Article ID VENTILATION; DEVICES; RATES; BLOOD; FISH AB Heart rate and swimming-speed responses to acute hypoxia were measured in skipjack (Katsuwonus pelamis) and yellowfin tunas (Thunnus albacares). Swimming speeds began to increase in both species when O2 tension (Po2) reached approximately 124 mmHg. Bradycardia became significant in both species when Po2 reached approximately 130 mmHg. Heart rate fell with Po2 in yellowfin tuna, but, in skipjack tuna, it increased at the lowest O2 levels reached (89-70 mmHg). Bradycardia occurred in both species despite concomitant increases in swimming speed. A continuous infusion dye dilution system was used to monitor changes in ventilation volume (V(g)) during hypoxia in yellowfin tuna. As Po2 fell, V(g) increased. At the lowest O2 levels (109-90 mmHg), V(g) was 45% higher than during normoxia. Ventilation volume increased despite no concomitant increases in swimming speed. Data from these experiments were used to develop a model capable of predicting O2 demand and delivery, maximum sustainable (i.e., aerobic) swimming speeds, and minimum survivable O2 levels for yellowfin and skipjack tunas. Results from the model indicate that the cardiorespiratory system of tunas is capable of maximum rates of O2 delivery, even at low swimming speeds, that are approximately three times those of other active teleosts. We believe that, because the pelagic environment provides no place to hide and rest following exhaustive activity, the ability of the cardiorespiratory system of tunas to deliver O2 to the tissues at high rates evolved for the rapid repayment of O2 debts rather than to permit exceptionally high sustained swimming speeds. C1 NOAA,NATL MARINE FISHERIES SERV,HONOLULU LAB,SW FISHERIES SCI CTR,2570 DOLE ST,HONOLULU,HI 96822. UNIV HAWAII,JOHN A BURNS SCH MED,DEPT PHYSIOL,HONOLULU,HI 96822. NR 43 TC 62 Z9 62 U1 0 U2 4 PU UNIV CHICAGO PRESS PI CHICAGO PA 5720 S WOODLAWN AVE, CHICAGO, IL 60637 SN 0031-935X J9 PHYSIOL ZOOL JI Physiol. Zool. PD MAY-JUN PY 1991 VL 64 IS 3 BP 787 EP 811 PG 25 WC Physiology; Zoology SC Physiology; Zoology GA FY293 UT WOS:A1991FY29300011 ER PT J AU TEKLE, E ASTUMIAN, RD CHOCK, PB AF TEKLE, E ASTUMIAN, RD CHOCK, PB TI ELECTROPORATION BY USING BIPOLAR OSCILLATING ELECTRIC-FIELD - AN IMPROVED METHOD FOR DNA TRANSFECTION OF NIH 3T3 CELLS SO PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF THE UNITED STATES OF AMERICA LA English DT Article DE GENE TRANSFECTION; ELECTROPERMEABILIZATION ID HIGH-EFFICIENCY TRANSFORMATION; GENE-TRANSFER; MAMMALIAN-CELLS; INTACT YEAST; ELECTROPERMEABILIZATION; PROTOPLASTS; EXPRESSION; MEMBRANES AB Using the plasmid DNA pSV2-neo (which, when integrated into the cellular genome confers resistance to the antibiotic G418 for selection), we examined and compared the transfection efficiency on NIH 3T3 cells electro-permeabilized by applying a sequence of high-frequency unipolar or bipolar square waves or a single square pulse. Results show that a bipolar square wave is, at least, 1.7- and 5.5-fold more efficient than the unipolar square wave and single square pulse, respectively. In the range of electric field strength used for optimum transfection, the survivability of electro-permeabilized cells was comparable between the unipolar and bipolar square waves but fell considerably with the single square pulse. Qualitative comparison of cell permeabilization induced by the three types of wave forms and monitored by ethidium bromide uptake revealed that only the bipolar square wave permeabilizes the cell membrane symmetrically at the two hemispheres facing the electrodes. With unipolar square wave or single square pulse, the membrane is permeabilized either on one side or asymmetrically. Taken together, our results suggests that permeabilization of the membrane at multiple sites without affecting cell survivability may account for the improvements in transfection efficiency observed with bipolar oscillating electric fields. C1 NATL INST STAND & TECHNOL,DIV BIOTECHNOL,GAITHERSBURG,MD 20899. RP TEKLE, E (reprint author), NHLBI,BIOCHEM LAB,METAB REGULAT SECT,BLDG 3,ROOM 203,BETHESDA,MD 20892, USA. NR 28 TC 120 Z9 124 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 MAY PY 1991 VL 88 IS 10 BP 4230 EP 4234 DI 10.1073/pnas.88.10.4230 PG 5 WC Multidisciplinary Sciences SC Science & Technology - Other Topics GA FM042 UT WOS:A1991FM04200036 PM 2034667 ER PT J AU TANS, PP AF TANS, PP TI UNCERTAINTIES IN THE GLOBAL CARBON-CYCLE SO PURE AND APPLIED CHEMISTRY LA English DT Article RP TANS, PP (reprint author), NOAA,CLIMATE MONITORING & DIAGNOST LAB,BOULDER,CO 80303, USA. NR 0 TC 2 Z9 2 U1 0 U2 1 PU BLACKWELL SCIENCE LTD PI OXFORD PA OSNEY MEAD, OXFORD, OXON, ENGLAND OX2 0EL SN 0033-4545 J9 PURE APPL CHEM JI Pure Appl. Chem. PD MAY PY 1991 VL 63 IS 5 BP 766 EP 768 PG 3 WC Chemistry, Multidisciplinary SC Chemistry GA FJ389 UT WOS:A1991FJ38900011 ER PT J AU MARTINEZ, RI AF MARTINEZ, RI TI STANDARD REFERENCE SPECTRA FOR TANDEM MASS-SPECTROMETRY QUALITY ASSURANCE, PERFORMANCE EVALUATION AND PROFICIENCY TESTING - TANDEM MASS SPECTROMETERS WHICH USE RF-ONLY MULTIPOLE COLLISION CELLS SO RAPID COMMUNICATIONS IN MASS SPECTROMETRY LA English DT Review ID KINETIC-ENERGY RELEASE; ACETONE MOLECULAR ION; PHOTOELECTRON-PHOTOION COINCIDENCE; INDUCED DISSOCIATION; TRIPLE QUADRUPOLES; ALIPHATIC-KETONES; POLYATOMIC IONS; ACTIVATED DISSOCIATION; FRAGMENTATION; DYNAMICS AB The collisionally activated dissociation (CAD) of the acetone cation (m/z 58) can be used for quality assurance, performance evaluation, and proficiency testing of CAD measurements in tandem mass spectrometry (MS/MS) instruments which use RF-only multipole collision cells. The absolute branching ratios (product distributions) of the CAD fragment ions, when measured as a function of the center-of-mass collision energy E(cm), can provide an objective basis for quality assurance whenever MS/MS methods are used (viz, to validate how well the target thickness, ion-containment efficiency, and collision energy are being controlled in various instruments). C1 NATL INST STAND & TECHNOL,DIV CHEM KINET & THERMODYNAM,GAITHERSBURG,MD 20899. NR 45 TC 13 Z9 13 U1 0 U2 1 PU JOHN WILEY & SONS LTD PI W SUSSEX PA BAFFINS LANE CHICHESTER, W SUSSEX, ENGLAND PO19 1UD SN 0951-4198 J9 RAPID COMMUN MASS SP JI Rapid Commun. Mass Spectrom. PD MAY PY 1991 VL 5 IS 5 BP 245 EP 248 DI 10.1002/rcm.1290050508 PG 4 WC Chemistry, Analytical; Spectroscopy SC Chemistry; Spectroscopy GA FK629 UT WOS:A1991FK62900007 ER PT J AU ALVAREZ, R AF ALVAREZ, R TI STANDARD REFERENCE MATERIALS FOR DIOXINS AND OTHER ENVIRONMENTAL-POLLUTANTS SO SCIENCE OF THE TOTAL ENVIRONMENT LA English DT Article AB The National Institute of Standards and Technology issues approximately 1100 Standard Reference Materials (SRMs) certified for chemical composition or physical properties. A number of these SRMs has been developed to assist chemists in analyzing environmental samples more reliably for chlorinated dioxins and other organic pollutants. Certification of the pollutant concentration in a natural matrix SRM is based on concordant analyses by the NIST Organic Analytical Research Division using at least two independent methods. For a calibration solution, such as SRM 1614, Dioxin (2,3,7,8-TCDD) in Isooctane, certification is based on agreement of the calculated concentration based on the gravimetric preparation and the concentration as determined experimentally. SRM 1614 also includes a C-13-labeled 2,3,7,8-TCDD for use as an internal standard in methods based on gas chromatography/mass spectrometry. The certified concentrations (ng g-1) are 98.3 +/- 3.3 for the unlabeled dioxin and 95.6 +/- 1.5 for the labeled dioxin. The certificates for SRM 1588, Organics in Cod Liver Oil, and SRM 1589, Polychlorinated Biphenyls (as Aroclor 1260) in Human Serum, provide noncertified concentrations of dioxins. Concentrations of chlorinated dioxins in two urban particulate SRMs have been reported in the literature. RP ALVAREZ, R (reprint author), NATL INST STAND & TECHNOL,STAND REFERENCE MAT PROGRAM,GAITHERSBURG,MD 20899, 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 0048-9697 J9 SCI TOTAL ENVIRON JI Sci. Total Environ. PD MAY 1 PY 1991 VL 104 IS 1-2 BP 1 EP 7 DI 10.1016/0048-9697(91)90003-W PG 7 WC Environmental Sciences SC Environmental Sciences & Ecology GA FP878 UT WOS:A1991FP87800002 PM 1871585 ER PT J AU CASELLA, RC AF CASELLA, RC TI A THEORETICAL-MODEL FOR THE TUNNELING-GAP ANISOTROPY OBSERVED IN LAYERED COPPER-OXIDE HIGH-TEMPERATURE SUPERCONDUCTORS SO SOLID STATE COMMUNICATIONS LA English DT Article ID HIGH-TC SUPERCONDUCTOR; ENERGY-GAP; CU-O; PLANE AB A two-band model, in which the pair constituents in one band are linked via double intermediate boson (IB) exchange with a third fermion in the other band, is invoked to understand the tunneling-gap anisotropy observed in Bi2Sr2CaCu2O8 single crystals. The coordinates of the two IBs and the third fermion are integrated out, leading to effective pair correlations. The theory is presently in agreement with the data and subject to further experimental test via more precise measurements. Within the model, present data imply that the IB cut-off omega > 0.3 eV. The observed broad i.r. excitation centered at almost-equal-to 3000 cm-1 is taken as a candidate for the (possibly composite) IB. Experimental implications are discussed in a general context. RP CASELLA, RC (reprint author), NATL INST STAND & TECHNOL,GAITHERSBURG,MD 20899, USA. NR 13 TC 0 Z9 0 U1 0 U2 0 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD, ENGLAND OX5 1GB SN 0038-1098 J9 SOLID STATE COMMUN JI Solid State Commun. PD MAY PY 1991 VL 78 IS 5 BP 377 EP 379 DI 10.1016/0038-1098(91)90687-Q PG 3 WC Physics, Condensed Matter SC Physics GA FL906 UT WOS:A1991FL90600012 ER PT J AU MAGRINI, KA GEBHARD, SC KOEL, BE FALCONER, JL AF MAGRINI, KA GEBHARD, SC KOEL, BE FALCONER, JL TI METHYL-CHLORIDE AND TRICHLOROSILANE ADSORPTION ON CU(110) SO SURFACE SCIENCE LA English DT Article ID PHOTOELECTRON SPECTRA; INTERFACES; SPECTROSCOPY; HALIDES; PT(111); SILICON; COPPER; MATRIX; CO AB The adsorption of methyl chloride (CH3Cl) and trichlorosilane (HSiCl3) on Cu(110) was studied by temperature-programmed desorption (TPD), high resolution electron energy loss spectroscopy (HREELS), and ultraviolet photoelectron spectroscopy (UPS). Methyl chloride interacts weakly with Cu(110) at 100 K, and we estimate from TPD that the adsorption energy is only 8-10 kcal/mol. It adsorbs nondissociatively and reversibly on Cu(110) under these conditions; no evidence of thermal decomposition was observed. HREELS indicates that chemisorbed CH3Cl adopts a bonding geometry with a symmetry lower than C3v, presumably bonded to the surface through the Cl atom with the methyl group tipped over with respect to the surface normal. In contrast, HSiCl3 interacts strongly with Cu(110) at 100 K. Trichlorosilane is initially dissociatively adsorbed, but most of the HSiCl3 in the chemisorbed monolayer adsorbs molecularly and reversibly due to the strong poisoning of the Cu(110) surface by Cl adatoms. Thermal decomposition, which leaves some Si-Cl and Si-H bonds intact, occurs readily at 140-300 K. Silicon deposited on the Cu(110) surface during HSiCl3 decomposition is in a metallic bonding environment, directly bonded to the Cu. Low coverages of HSiCl3 form an H-2 desorption state near 300 K that is attributed to the decomposition of an SiH surface species with an activation energy for decomposition of 18 kcal/mol. This H2 desorption state is not observed for the thermal decomposition of large coverages of HSiCl3 on Cu(110) nor for pre-chlorinated Cu(110) surfaces. On pre-chlorinated Cu(110), HSiCl3 is only weakly adsorbed with an adsorption energy of 8 kcal/mol and is adsorbed nondissociatively with complete reversibility. The importance of these results for understanding the Cu-catalyzed direct synthesis reaction between CH3Cl and Si to form methylchlorosilanes is discussed. C1 UNIV COLORADO,DEPT CHEM & BIOCHEM,BOULDER,CO 80309. UNIV COLORADO,DEPT CHEM ENGN,BOULDER,CO 80309. UNIV COLORADO,NOAA,COOPERAT INST RES ENVIRONM SCI,BOULDER,CO 80309. RI Koel, Bruce/H-3857-2013 OI Koel, Bruce/0000-0002-0032-4991 NR 29 TC 17 Z9 17 U1 1 U2 8 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0039-6028 J9 SURF SCI JI Surf. Sci. PD MAY PY 1991 VL 248 IS 1-2 BP 93 EP 103 DI 10.1016/0039-6028(91)90064-Y PG 11 WC Chemistry, Physical; Physics, Condensed Matter SC Chemistry; Physics GA FT809 UT WOS:A1991FT80900016 ER PT J AU HUTSON, FL RAMAKER, DE KOEL, BE AF HUTSON, FL RAMAKER, DE KOEL, BE TI SPECTROSCOPIC EVIDENCE FOR CARBON CARBON BONDING IN CARBIDIC LAYERS ON METALS SO SURFACE SCIENCE LA English DT Article ID AUGER LINE-SHAPE; TROPSCH HYDROCARBON SYNTHESIS; ELECTRONIC-STRUCTURE; GRAPHITIC CARBON; THERMAL-DECOMPOSITION; RESONANT EXCITATION; TRANSITION-METALS; NI(111) SURFACES; NICKEL SURFACES; ETHYLENE AB We examine previously reported ultraviolet photoelectron, CK electron energy loss, and CKVV Auger spectroscopic data from "carbidic" layers formed at temperatures between 500 and 650 K on Ni(100) and Ni(111). The "carbidic" layers studied were made from either CO or C2H4 exposure to the metal surface. These data indicate that significant amounts of carbon-carbon bonding exists on the surface in addition to the carbon-metal bonding with the substrate, revealing the presence of chemisorbed species, such as C2, and maybe even C3, etc. Quantitative interpretations of the Auger data indicate that 20 to 30% of the total electron density has carbon-carbon bonding character. Observed changes in the spectra obtained from different surfaces or at different coverages are accounted for by variations in the fraction of carbon-carbon bonding character. C1 USN,RES LAB,DIV CHEM,WASHINGTON,DC 20375. UNIV COLORADO,DEPT CHEM & BIOCHEM,BOULDER,CO 80309. UNIV COLORADO,NOAA,COOPERAT INST RES ENVIRONM SCI,BOULDER,CO 80309. RP HUTSON, FL (reprint author), GEORGE WASHINGTON UNIV,DEPT CHEM,WASHINGTON,DC 20052, USA. RI Koel, Bruce/H-3857-2013 OI Koel, Bruce/0000-0002-0032-4991 NR 71 TC 27 Z9 27 U1 0 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 MAY PY 1991 VL 248 IS 1-2 BP 104 EP 118 DI 10.1016/0039-6028(91)90065-Z PG 15 WC Chemistry, Physical; Physics, Condensed Matter SC Chemistry; Physics GA FT809 UT WOS:A1991FT80900017 ER PT J AU HUTSON, FL RAMAKER, DE KOEL, BE GEBHARD, SC AF HUTSON, FL RAMAKER, DE KOEL, BE GEBHARD, SC TI INTERPRETATION OF THE CARBON AUGER LINE-SHAPES FOR THE ADSORPTION AND DECOMPOSITION OF ETHYLENE ON NI(100) SO SURFACE SCIENCE LA English DT Article ID ENERGY LOSS SPECTROSCOPY; SINGLE-CRYSTAL SURFACES; NARROW-BAND METALS; ELECTRON-SPECTROSCOPY; THERMAL-DECOMPOSITION; RESONANT EXCITATION; GRAPHITIC CARBON; CHEMISORBED CO; NICKEL CARBIDE; FINE-STRUCTURE AB The CKVV Auger line shapes of ethylene chemisorbed on Ni(100) at 100, 250, 300 and 600 K are reported and consistently interpreted. These line shapes are representative of pi-bonded ethylene (C2H4(a)) at 100 K, sigma-bonded vinyl (CHCH2(a)) at 250 K, a mixture of ethynyl (CCH(a)), methylidyne (CH(a)) and di-sigma-bonded acetylene (HCCH(a)) at 300 K, and carbidic carbon (C(a)) at 600 K on the surface. The Auger line shape of graphitic carbon adlayers on Ni is also interpreted. The line shapes are found to consist of adsorbate-adsorbate, adsorbate-substrate, and substrate-substrate components, which are denoted by the final location of the two holes created by the Auger process. The adsorbate-adsorbate component, for the C2 chemisorbed species, reflects primarily the valence density of states of ethylene and shows negligible hole-hole correlation effects due to electron transfer from the metal. This is in contrast to the graphitic adlayer where the adsorbate-adsorbate component has the same tine shape as bulk graphite and exhibits significant correlation effects. The adsorbate-substrate and substrate-substrate components seen in all of the tine shapes directly reflect the adsorbate-substrate pi or sigma-bonding character, and the extent of screening via charge transfer from the metal to the core excited adsorbate. C1 USN,RES LAB,DIV CHEM,WASHINGTON,DC 20375. UNIV COLORADO,DEPT CHEM & BIOCHEM,BOULDER,CO 80309. UNIV COLORADO,NOAA,COOPERAT INST RES ENVIRONM SCI,BOULDER,CO 80309. RP HUTSON, FL (reprint author), GEORGE WASHINGTON UNIV,DEPT CHEM,WASHINGTON,DC 20052, USA. RI Koel, Bruce/H-3857-2013 OI Koel, Bruce/0000-0002-0032-4991 NR 81 TC 17 Z9 17 U1 0 U2 2 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0039-6028 J9 SURF SCI JI Surf. Sci. PD MAY PY 1991 VL 248 IS 1-2 BP 119 EP 133 DI 10.1016/0039-6028(91)90066-2 PG 15 WC Chemistry, Physical; Physics, Condensed Matter SC Chemistry; Physics GA FT809 UT WOS:A1991FT80900018 ER PT J AU MADEY, TE SONG, KJ DONG, CZ DEMMIN, RA AF MADEY, TE SONG, KJ DONG, CZ DEMMIN, RA TI THE STABILITY OF ULTRATHIN METAL-FILMS ON W(110) AND W(111) SO SURFACE SCIENCE LA English DT Article; Proceedings Paper CT 14TH INTERNATIONAL SEMINAR ON SURFACE PHYSICS CY MAY 21-26, 1990 CL PRZESIEKA, POLAND SP UNIV WROCLAW, INST EXPTL PHYS, MINIST NATL EDUC POLAND ID CARBON-MONOXIDE; ADSORBED LAYER; PD LAYERS; SURFACE; ADSORPTION; OVERLAYERS; PLATINUM; NB(110); OXYGEN; CO AB Ultrathin films of platinum on tungsten display a rich variety of phenomena related to epitaxial growth. Pt grows on W(110) in a layer-by-layer mode at 300 K; upon annealing multilayers of Pt to T > 800 K, clusters of three-dimensional crystallites form on top of a pseudo-morphic Pt monolayer. When oxygen is present on the surface, the Pt monolayer is no longer stable. Annealing coadsorbed Pt and O on W(110) causes nearly all the Pt to agglomerate into clusters as the oxygen largely replaces the monolayer on the surface. Annealing Pt on W(111) in the range 800 < T < 1500 K leads to a different behavior: microscopic facets of W having {211} orientation are formed. The faceting appears to be driven by a Pt enhanced anisotropy in the surface free energy. Results based on LEED, Auger, and scanning tunneling microscopy (STM) are presented. C1 NATL INST STAND & TECHNOL,GAITHERSBURG,MD 20899. RUTGERS STATE UNIV,SURFACE MODIFICAT LAB,PISCATAWAY,NJ 08855. RP MADEY, TE (reprint author), RUTGERS STATE UNIV,DEPT PHYS & ASTRON,PISCATAWAY,NJ 08855, USA. RI Song, Ker-Jar/F-7913-2012 NR 33 TC 58 Z9 58 U1 1 U2 13 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0039-6028 J9 SURF SCI JI Surf. Sci. PD MAY PY 1991 VL 247 IS 2-3 BP 175 EP 187 DI 10.1016/0039-6028(91)90124-B PG 13 WC Chemistry, Physical; Physics, Condensed Matter SC Chemistry; Physics GA FN801 UT WOS:A1991FN80100016 ER PT J AU MEE, RW EBERHARDT, KR REEVE, CP AF MEE, RW EBERHARDT, KR REEVE, CP TI CALIBRATION AND SIMULTANEOUS TOLERANCE INTERVALS FOR REGRESSION SO TECHNOMETRICS LA English DT Article DE DISCRIMINATION INTERVAL; MULTIPLE-USE CALIBRATION; SIMULTANEOUS INFERENCE AB Simultaneous calibration (or discrimination) intervals in regression were proposed by Lieberman, Miller, and Hamilton (1967) and by Scheffe (1973). Those procedures enable one to construct confidence intervals for the unobserved values of the independent variable corresponding to an unlimited sequence of observations of the dependent variable in a regression model. These calibration intervals are conservative in that they are obtained from simultaneous tolerance intervals for which the actual confidence level exceeds the nominal level. Furthermore, all other existing simultaneous tolerance intervals in regression are likewise conservative. In this article, we propose simultaneous tolerance intervals that are narrower than previous intervals. Given the tables of factors included in this articles, they are also simple to construct and use in straightline calibration applications. C1 NATL INST STAND & TECHNOL,DIV STAT ENGN,GAITHERSBURG,MD 20899. WESTINGHOUSE SAVANNAH RIVER CO,AIKEN,SC 29808. RP MEE, RW (reprint author), UNIV TENNESSEE,DEPT STAT,KNOXVILLE,TN 37996, USA. NR 12 TC 25 Z9 25 U1 0 U2 0 PU AMER STATIST ASSN PI ALEXANDRIA PA 1429 DUKE ST, ALEXANDRIA, VA 22314 SN 0040-1706 J9 TECHNOMETRICS JI Technometrics PD MAY PY 1991 VL 33 IS 2 BP 211 EP 219 DI 10.2307/1269047 PG 9 WC Statistics & Probability SC Mathematics GA FJ198 UT WOS:A1991FJ19800010 ER PT J AU WELLS, JM AF WELLS, JM TI HYPERTHERMIA IN DIVERS AND DIVER SUPPORT PERSONNEL SO UNDERSEA BIOMEDICAL RESEARCH LA English DT Article; Proceedings Paper CT INTERNATIONAL SYMP ON DIVING IN HAZARDOUS WATER CY DEC, 1988 CL BETHESDA, MD DE DIVING EQUIPMENT; HEAT STRESS; HEAT STROKE RP WELLS, JM (reprint author), NOAA,DIVING PROGRAM,WASHINGTON,DC 20230, USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU UNDERSEA & HYPERBARIC MEDICAL SOC INC PI BETHESDA PA 9650 ROCKVILLE PIKE, BETHESDA, MD 20814 SN 0093-5387 J9 UNDERSEA BIOMED RES PD MAY PY 1991 VL 18 IS 3 BP 225 EP 227 PG 3 WC Oceanography SC Oceanography GA FR301 UT WOS:A1991FR30100012 PM 1853477 ER PT J AU PHOEL, WC WELLS, JM AF PHOEL, WC WELLS, JM TI EVOLUTION OF THE NATIONAL-OCEANIC-AND-ATMOSPHERIC-ADMINISTRATIONS CAPABILITIES FOR POLLUTED WATER DIVING SO UNDERSEA BIOMEDICAL RESEARCH LA English DT Article; Proceedings Paper CT INTERNATIONAL SYMP ON DIVING IN HAZARDOUS WATER CY DEC, 1988 CL BETHESDA, MD DE EQUIPMENT; TESTING; HELMET; MK 12; NOAA; SUIT-UNDER-SUIT; POLLUTION C1 NOAA,DIVING PROGRAM,ROCKVILLE,MD 20852. RP PHOEL, WC (reprint author), NOAA,NATL MARINE FISHERIES SERV,NE FISHERIES CTR,SANDY HOOK LAB,SANDY HOOK,NJ 07732, USA. NR 9 TC 0 Z9 0 U1 0 U2 0 PU UNDERSEA & HYPERBARIC MEDICAL SOC INC PI BETHESDA PA 9650 ROCKVILLE PIKE, BETHESDA, MD 20814 SN 0093-5387 J9 UNDERSEA BIOMED RES PD MAY PY 1991 VL 18 IS 3 BP 247 EP 252 PG 6 WC Oceanography SC Oceanography GA FR301 UT WOS:A1991FR30100015 PM 1853480 ER PT J AU KRANBUEHL, DE EICHINGER, D VERDIER, PH AF KRANBUEHL, DE EICHINGER, D VERDIER, PH TI SIMULATION STUDIES OF EXCLUDED VOLUME EFFECTS ON POLYMER-CHAIN DYNAMICS IN SEVERAL NONLATTICE MODELS SO MACROMOLECULES LA English DT Article ID CUBIC LATTICE MODELS; BEAD MOVEMENT RULES; MONTE-CARLO METHOD; COORDINATION-NUMBER; MULTICHAIN SYSTEMS; RELAXATION; DEPENDENCE; TIME; BEHAVIOR; FLUCTUATIONS AB Computer simulations of off-lattice bead-stick models of polymer chains with a variety of move rules have been carried out to gauge the effect of these move rules on the dynamical behavior of the chains. We report long relaxation times, translational diffusion constants, and mean-square end-to-end length for chains of from 9 to 99 beads, both with and without excluded volume. For several move rules the excluded volume constraints increase the chain-length dependence of the long relaxation times by about the square root of chain length, roughly twice the exponent expected from simple scaling arguments based on the expansion of equilibrium dimensions by excluded volume. Move rules analogous to some of those used in the present study have been employed by others in previous lattice-model studies. Those earlier lattice-model results appeared to suggest that relaxation times scale like mean-square chain dimensions. Our present results suggest, however, that the earlier result is an artifact resulting from the combination of lattice constraints with the use of move rules explicitly dependent upon local chain conformation. C1 NATL INST STAND & TECHNOL, DIV POLYMERS, GAITHERSBURG, MD 20899 USA. COLL WILLIAM & MARY, DEPT CHEM, WILLIAMSBURG, VA 23185 USA. NR 61 TC 14 Z9 14 U1 0 U2 0 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 0024-9297 EI 1520-5835 J9 MACROMOLECULES JI Macromolecules PD APR 29 PY 1991 VL 24 IS 9 BP 2419 EP 2427 DI 10.1021/ma00009a045 PG 9 WC Polymer Science SC Polymer Science GA FJ881 UT WOS:A1991FJ88100045 ER PT J AU HEINZEN, DJ BOLLINGER, JJ MOORE, FL ITANO, WM WINELAND, DJ AF HEINZEN, DJ BOLLINGER, JJ MOORE, FL ITANO, WM WINELAND, DJ TI ROTATIONAL EQUILIBRIA AND LOW-ORDER MODES OF A NONNEUTRAL ION PLASMA SO PHYSICAL REVIEW LETTERS LA English DT Article ID PURE ELECTRON-PLASMA; NONNEUTRAL PLASMA; TRANSPORT; RESONANCES; COLUMN; LENGTH; WAVES AB We study rotational equilibria and low-order electrostatic modes of a magnetically confined, non-neutral ion plasma. The plasma rotation rate is controlled with radiation pressure from a laser beam and is continuously varied over the entire allowed range, including Brillouin flow. Excitation of an asymmetric plasma mode by a static field asymmetry is observed. The symmetric quadrupole mode is also studied; its behavior is characteristic of a strongly magnetized plasma at low density, and of an unmagnetized plasma at Brillouin flow. C1 NATL INST STANDARDS & TECHNOL,DIV TIME & FREQUENCY,BOULDER,CO 80303. NR 22 TC 92 Z9 92 U1 1 U2 2 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 0031-9007 J9 PHYS REV LETT JI Phys. Rev. Lett. PD APR 22 PY 1991 VL 66 IS 16 BP 2080 EP 2083 DI 10.1103/PhysRevLett.66.2080 PG 4 WC Physics, Multidisciplinary SC Physics GA FH366 UT WOS:A1991FH36600008 ER PT J AU JOKLIK, RG HORVATH, JJ SEMERJIAN, HG AF JOKLIK, RG HORVATH, JJ SEMERJIAN, HG TI TEMPERATURE-MEASUREMENTS IN FLAMES USING THERMALLY ASSISTED LASER-INDUCED FLUORESCENCE OF GA SO APPLIED OPTICS LA English DT Article ID REDISTRIBUTION; ATOMS; OH AB The use of thermally assisted fluorescence (THAF) for temperature measurements has been investigated in a laminar, premixed C2H2/O2/Ar flame seeded with Ga atoms. Average temperature measurements were made with an uncertainty of less than +/- 100 K in flames > 2150 K and were found to be in agreement with sodium line reversal temperature measurements and equilibrium calculations. In both fuel rich and lean flames spanning equivalence ratios from 0.75 to 2.0, it was found that composition influenced the measured temperatures, resulting in an accuracy of +/- 100 K over this range of flame conditions. Dilution of the flame with N2 rather than Ar resulted in measured temperatures that were substantially higher than the calculated adiabatic flame temperature, indicating that, in this case, a partial Boltzmann equilibrium is not established among the collisionally populated levels of Ga used for the measurement. These results indicate that THAF with gallium as the thermometric species is limited to cases in which an inefficient quencher, such as a rare gas, is the primary diluent. RP JOKLIK, RG (reprint author), NATL INST STAND & TECHNOL,CTR CHEM TECHNOL,GAITHERSBURG,MD 20899, USA. NR 16 TC 10 Z9 10 U1 0 U2 2 PU OPTICAL SOC AMER PI WASHINGTON PA 2010 MASSACHUSETTS AVE NW, WASHINGTON, DC 20036 SN 0003-6935 J9 APPL OPTICS JI Appl. Optics PD APR 20 PY 1991 VL 30 IS 12 BP 1497 EP 1504 PG 8 WC Optics SC Optics GA FJ906 UT WOS:A1991FJ90600012 PM 20700311 ER PT J AU ZINK, LR EVENSON, KM MATSUSHIMA, F NELIS, T ROBINSON, RL AF ZINK, LR EVENSON, KM MATSUSHIMA, F NELIS, T ROBINSON, RL TI ATOMIC OXYGEN FINE-STRUCTURE SPLITTINGS WITH TUNABLE FAR-INFRARED SPECTROSCOPY SO ASTROPHYSICAL JOURNAL LA English DT Article DE INFRARED, SPECTRA; INTERSTELLAR, MATTER; LABORATORY SPECTRA; PLANETS, ATMOSPHERES ID RADIATION; SPECTRUM; EMISSION AB We have accurately measured fine-structure splittings of atomic oxygen (O-16) in the ground state using a tunable far-infrared spectrometer. The P-3(0)-P-3(1) splitting is 2,060,069.09 (10) MHz, and the P-3(1)-P-3(2) splitting is 4,744,777.49 (16) MHz. These frequencies are important for measuring atomic oxygen concentration in Earth's atmosphere and the interstellar medium. C1 TOYAMA UNIV,DEPT PHYS,TOYAMA 930,JAPAN. MIT,DEPT CHEM,CAMBRIDGE,MA 02139. NOAA,COOPERAT INST RES ENVIRONM SCI,BOULDER,CO 80303. UNIV COLORADO,BOULDER,CO 80303. RP ZINK, LR (reprint author), NATL INST STAND & TECHNOL,325 BROADWAY,BOULDER,CO 80303, USA. RI Nelis, Thomas/D-9581-2015 OI Nelis, Thomas/0000-0002-0061-8850 NR 16 TC 25 Z9 25 U1 0 U2 2 PU UNIV CHICAGO PRESS PI CHICAGO PA 5720 S WOODLAWN AVE, CHICAGO, IL 60637 SN 0004-637X J9 ASTROPHYS J JI Astrophys. J. PD APR 20 PY 1991 VL 371 IS 2 BP L85 EP L86 DI 10.1086/186008 PN 2 PG 2 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA FF984 UT WOS:A1991FF98400010 ER PT J AU BALDOCCHI, DD MEYERS, TP AF BALDOCCHI, DD MEYERS, TP TI TRACE GAS-EXCHANGE ABOVE THE FLOOR OF A DECIDUOUS FOREST .1. EVAPORATION AND CO2 EFFLUX SO JOURNAL OF GEOPHYSICAL RESEARCH-ATMOSPHERES LA English DT Article ID CARBON-DIOXIDE EVOLUTION; OAK-HICKORY FOREST; WATER-VAPOR; PRESSURE-FLUCTUATIONS; LITTER DECOMPOSITION; TURBULENCE SPECTRA; SOIL SURFACE; CANOPY; EVAPOTRANSPIRATION; TEMPERATURE AB The eddy correlation method has great potential for directly measuring trace gas fluxes at the floor of a forest canopy, but a thorough validation study has not been yet conducted. Another appeal of the eddy correlation method is its ability to study processes that regulate and modulate gas exchange between the soil/litter complex and the atmosphere that cannot be probed with chambers. In this paper we report on eddy correlation measurements of water vapor, sensible heat, and carbon dioxide exchange that were made at the floor of a deciduous forest. The validity of the eddy correlation method to measure the emission of water vapor and CO2 from a deciduous forest floor is demonstrated by our ability to close the surface energy budget during periods that meet the requirements of the technique. Water vapor fluxes from a dry forest floor are strongly influenced by large-scale turbulent events that penetrate deep into the canopy. The frequency of these turbulent events prevents equilibrium evaporation rates from being achieved because the dynamic time constant for water vapor exchange is longer. Consequently, maximal evaporation rates are capped to rates defined by the product of the driving potential of the atmosphere and the surface conductance. On the other hand, evaporation from a wet forest floor proceeds at rates reaching or exceeding equilibrium evaporation and are highly correlated with static pressure fluctuations. CO2 efflux rates are governed by litter and soil temperature, as expected. But we also find a significant correlation between static pressure fluctuations and soil/litter CO2 exchange rates. RP BALDOCCHI, DD (reprint author), NOAA, DIV ATMOSPHER TURBULENCE & DIFFUS, POB 2456, OAK RIDGE, TN 37831 USA. RI Baldocchi, Dennis/A-1625-2009; Meyers, Tilden/C-6633-2016 OI Baldocchi, Dennis/0000-0003-3496-4919; NR 74 TC 131 Z9 138 U1 3 U2 17 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 APR 20 PY 1991 VL 96 IS D4 BP 7271 EP 7285 DI 10.1029/91JD00269 PG 15 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA FJ455 UT WOS:A1991FJ45500001 ER PT J AU ROSELLE, SJ PIERCE, TE SCHERE, KL AF ROSELLE, SJ PIERCE, TE SCHERE, KL TI THE SENSITIVITY OF REGIONAL OZONE MODELING TO BIOGENIC HYDROCARBONS SO JOURNAL OF GEOPHYSICAL RESEARCH-ATMOSPHERES LA English DT Article ID NATURAL HYDROCARBONS; EMISSIONS; FOREST; URBAN AB The sensitivity of regional ozone concentrations to biogenic hydrocarbons in the northeastern United States has been examined using an Eulerian grid photochemical model having a horizontal resolution of 18 km. A 6-day period during which observed ozone concentrations exceeded 200 ppb was simulated. Detailed estimates of biogenic nonmethane hydrocarbon (NMHC) emissions were included in the model simulations. Overall, biogenic emissions were of the same order of magnitude as anthropogenic emissions. Approximately 33% of the biogenic inventory was in the form of isoprene, with the remainder of the NMHC in the form of monoterpenes and unidentified NMHC. Three model sensitivity runs were analyzed in which biogenic emissions, and then anthropogenic hydrocarbon emissions, were selectively removed from the emissions data set. Episode maximum predicted ozone concentrations were compared for each simulation, and a detailed chemical analysis was performed on two trajectories within the modeling domain. The analysis showed that the relative impact of biogenic compared to anthropogenic hydrocarbons on ozone generation varied spatially over the model domain. The biogenic influence on ozone was greatest in western and southern sections of the domain, particularly in the Ohio Valley, while the anthropogenic influence was greatest in the urbanized Northeast Corridor and industrial Great Lakes area. C1 NOAA, AIR RESOURCES LAB, DIV ATMOSPHER SCI MODELING, RES TRIANGLE PK, NC USA. NR 28 TC 63 Z9 66 U1 0 U2 2 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 APR 20 PY 1991 VL 96 IS D4 BP 7371 EP 7394 DI 10.1029/91JD00005 PG 24 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA FJ455 UT WOS:A1991FJ45500007 ER PT J AU GRODY, NC AF GRODY, NC TI CLASSIFICATION OF SNOW COVER AND PRECIPITATION USING THE SPECIAL SENSOR MICROWAVE IMAGER SO JOURNAL OF GEOPHYSICAL RESEARCH-ATMOSPHERES LA English DT Article ID RADIOMETER AB The special sensor microwave imager (SSMI) is a seven-channel microwave radiometer which has dual polarized channels at 19, 37, and 85 GHz and a vertically polarized channel at 22 GHz. A detailed evaluation of all SSMI channels is made in arriving at the optimum channel selection for the global identification of precipitation and snow cover without the use of any ancillary information. The resulting algorithm takes the form of a decision tree which uses the dual polarized channels at 19 GHz and the vertically polarized channels at 22 and 85 GHz. These four channels enable the identification of precipitation from all other atmospheric and surface features, including snow cover. RP GRODY, NC (reprint author), NOAA, ATLANTIC OCEANOG & METEOROL, DIV HURRICANE RES, SATELLITE RES LAB, CODE E-RA 14, CORAL GABLES, FL 33146 USA. NR 22 TC 306 Z9 324 U1 1 U2 12 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 APR 20 PY 1991 VL 96 IS D4 BP 7423 EP 7435 DI 10.1029/91JD00045 PG 13 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA FJ455 UT WOS:A1991FJ45500011 ER PT J AU BARNES, RA MCMASTER, LR CHU, WP MCCORMICK, MP GELMAN, ME AF BARNES, RA MCMASTER, LR CHU, WP MCCORMICK, MP GELMAN, ME TI STRATOSPHERIC AEROSOL AND GAS EXPERIMENT-II AND ROCOZ-A OZONE PROFILES AT NATAL, BRAZIL - A BASIS FOR COMPARISON WITH OTHER SATELLITE INSTRUMENTS SO JOURNAL OF GEOPHYSICAL RESEARCH-ATMOSPHERES LA English DT Article ID DATA ASSIMILATION SYSTEM; METEOROLOGICAL ROCKETSONDE; SPECTROMETER; INVERSION; SAGE; CONSTITUENTS; MESOSPHERE; PRECISION; ALGORITHM AB We present the results of comparisons of satellite measurements of ozone from the Stratospheric Aerosol and Gas Experiment II (SAGE II) with in situ measurements from ROCOZ-A and electrochemical concentration cell (ECC) ozonesondes at Natal, Brazil (5.9-degrees-S, 35.2-degrees-W), during the southern hemisphere autumn of 1985. Since data were collected over a region of low ozone variability, comparisons were made of the mean values of 14 SAGE II profiles with the mean values of 7 ROCOZ-A and 7 ECC profiles, rather than of a more limited set of paired comparisons. The basic comparison presented here is ozone number density versus geometric altitude, the fundamental ozone measurement from SAGE II. Over the altitude region from 20 to 52 km SAGE II ozone densities averaged 0.4% lower than ROCOZ-A. The average of the absolute values of the ozone density differences for the two instruments was 2.4% over these altitudes. Owing in large part to the number of profiles in the data sets, the 95% confidence limits for the ozone density differences in these comparisons averaged 3.5% from 20 to 52 km, a significant improvement over previous results. In terms of ozone mixing ratio versus geometric altitude from 20 to 52 km, SAGE II values had a difference of 3.4% from ROCOZ-A (SAGE II higher), an average absolute difference of 3.8%, and an average of 4.7% for the 95% confidence limits. Differences between the ozone density and mixing ratio results are due to the auxiliary temperature and pressure values for the satellite and in situ instruments. The effects of pressure differences on the vertical positioning of the ozone profiles are not important for the altitude-based comparisons of SAGE II and ROCOZ-A. However, they become an important consideration in the comparisons of SAGE II with pressure-based ozone measurements from other satellite instruments. The composite sets of ozone, temperature, and pressure values presented here form an excellent basis for comparisons with other satellite ozone measurements. C1 NASA, LANGLEY RES CTR, DIV ATMOSPHER SCI, HAMPTON, VA 23665 USA. NOAA, NATL WEATHER SERV, NATL METEOROL CTR, CTR CLIMATE ANAL, WASHINGTON, DC 20233 USA. RP BARNES, RA (reprint author), CHEMAL INC, POB 44, WALLOPS ISL, VA 23337 USA. NR 61 TC 12 Z9 12 U1 0 U2 0 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 APR 20 PY 1991 VL 96 IS D4 BP 7515 EP 7530 DI 10.1029/90JD02664 PG 16 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA FJ455 UT WOS:A1991FJ45500017 ER PT J AU FAHR, A LAUFER, A KLEIN, R BRAUN, W AF FAHR, A LAUFER, A KLEIN, R BRAUN, W TI REACTION-RATE DETERMINATIONS OF VINYL RADICAL REACTIONS WITH VINYL, METHYL, AND HYDROGEN-ATOMS SO JOURNAL OF PHYSICAL CHEMISTRY LA English DT Article ID RECOMBINATION REACTION CH3+CH3->C2H6; ABSORPTION CROSS-SECTION; LASER PHOTOLYSIS; RATE-CONSTANT; KINETICS; NM; OXYGEN; C2H3 AB Laser photolysis-kinetic spectroscopy, end-product analysis, and detailed modeling were used to investigate three reaction systems in detail. Included were vinyl-vinyl, vinyl-methyl, and vinyl-methyl-hydrogen atoms. Product ratios, as a function of the rate constants, could be approximated by using simple expressions. This greatly simplified the precise numerical modeling of these complex systems and also permitted a realistic error analysis. Reactions and rate constants (obtained at 25-degrees-C, 100 Torr of He) in units of cm3 (molecule s)-1 are summarized as follows: CH3 + CH3 --> C2H6, (0.52 +/- 0.05) x 10(-10), C2H3 + C2H3 --> C4H6, (1.2 +/- 0.2) x 10(-10); C2H3 + C2H3 --> C2H2 + C2H4, (0.24 +/- 0.05) x 10(-10); CH3 + C2H3 --> C3H6, (1.2 +/- 0.3) x 10(-10); CH3 + C2H3 --> CH4 + C2H2, (0.34 +/- 0.07) x 10(-10); C2H3 + H --> C2H4, (2.0 +/- 0.8) x 10(-10). The cross-combination rate constant obtained for vinyl-methyl is not twice the geometric mean of the vinyl-vinyl and methyl-methyl rate constants. This observation is explained on the basis that the vinyl-vinyl rate constant is faster than predicted by simple correlation arguments. The effect of bound low-lying triplet states of the product on the vinyl combination kinetics is discussed. RP FAHR, A (reprint author), NATL INST STAND & TECHNOL,DIV CHEM KINET,GAITHERSBURG,MD 20899, USA. NR 34 TC 96 Z9 96 U1 0 U2 8 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 SN 0022-3654 J9 J PHYS CHEM-US JI J. Phys. Chem. PD APR 18 PY 1991 VL 95 IS 8 BP 3218 EP 3224 DI 10.1021/j100161a047 PG 7 WC Chemistry, Physical SC Chemistry GA FH098 UT WOS:A1991FH09800047 ER PT J AU SHOUTE, LCT ALFASSI, ZB NETA, P HUIE, RE AF SHOUTE, LCT ALFASSI, ZB NETA, P HUIE, RE TI TEMPERATURE-DEPENDENCE OF THE RATE CONSTANTS FOR REACTION OF DIHALIDE AND AZIDE RADICALS WITH INORGANIC REDUCTANTS SO JOURNAL OF PHYSICAL CHEMISTRY LA English DT Article ID ELECTRON-TRANSFER; CHLORINE DIOXIDE; OXIDATION; CLO2; NO2; BARRIERS; COUPLE AB Rate constants for several reactions of inorganic radicals with inorganic reductants in aqueous solutions have been measured by pulse radiolysis as a function of temperature, generally between 5 and 75-degrees-C. The reactions studied were of the dihalide radicals, Cl2.-, Br2.-, and I2.-, the (SCN)2.- radical, and the neutral radical N3., reacting with the substitution-inert metal complexes, Fe(CN)6(4-), Mo(CN)8(4-), and W(CN)8(4-), and with the anions SO3(2-), HSO3-, NO2-, and ClO2-. The rate constants measured were in the range of 10(6) to 5 x 10(9) M-1 s-1 and the calculated Arrhenius activation energies ranged from 5 to 35 kJ mol-1. The preexponential factors also varied considerably, with log A ranging from 8.9 to 13.1. The temperature dependence of the reaction rate constant is correlated to the reaction exothermicity for the metal complexes, which apparently react by outer-sphere electron transfer. The simple anions, however, have lower activation energies, which do not correlate well with the exothermicities, suggesting that these anions probably react by an inner-sphere mechanism. C1 NATL INST STAND & TECHNOL,DIV CHEM KINET,GAITHERSBURG,MD 20899. RI Huie, Robert/A-5645-2010 NR 31 TC 18 Z9 18 U1 1 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 APR 18 PY 1991 VL 95 IS 8 BP 3238 EP 3242 DI 10.1021/j100161a050 PG 5 WC Chemistry, Physical SC Chemistry GA FH098 UT WOS:A1991FH09800050 ER PT J AU EDGINGTON, DN KLUMP, JV ROBBINS, JA KUSNER, YS PAMPURA, VD SANDIMIROV, IV AF EDGINGTON, DN KLUMP, JV ROBBINS, JA KUSNER, YS PAMPURA, VD SANDIMIROV, IV TI SEDIMENTATION-RATES, RESIDENCE TIMES AND RADIONUCLIDE INVENTORIES IN LAKE BAIKAL FROM CS-137 AND PB-210 IN SEDIMENT CORES SO NATURE LA English DT Article ID GREAT-LAKES; MODEL; MICHIGAN AB RADIONUCLIDES in lake sediments may act as indicators of the sedimentation rate of particles on which they are adsorbed; these rates in turn provide a direct indication of the residence times of particles in the water column. The radionuclide Cs-137 is anthropogenic (an atomic-bomb product), so that its concentration in sediments also reveals the input history of this species and thus a record of atmospheric contamination by this nuclide in the lake's watershed. Here we report measurements of Cs-137 and the natural radionuclide Pb-210 in cores from several stations throughout the three basins of Lake Baikal. The results confirm earlier indirect estimates 1 of the mean sedimentation rate, and show that the effective settling rate of these radionuclides is the same as that in the Great Lakes; the longer residence times for Lake Baikal are therefore simply a consequence of its greater depth. As well as allowing estimates of fluxes at the sediment-water interface 2-4, our results provide information on the timing of palaeolimnological events 5, on the existence of different depositional zones throughout the lake, on the long-term (decadal) diffusion of nuclides in sediments 6 and for the development of mass-balance models for sediments and contaminants 7-9. C1 NOAA,GREAT LAKES ENVIRONM RES LAB,ANN ARBOR,MI. ACAD SCI USSR,INST GEOCHEM,IRKUTSK 664003,USSR. ACAD SCI USSR,INST LIMNOL,IRKUTSK 664003,USSR. RP EDGINGTON, DN (reprint author), UNIV WISCONSIN,CTR GREAT LAKES STUDIES,MILWAUKEE,WI 53201, USA. NR 33 TC 105 Z9 114 U1 0 U2 20 PU MACMILLAN MAGAZINES LTD PI LONDON PA 4 LITTLE ESSEX STREET, LONDON, ENGLAND WC2R 3LF SN 0028-0836 J9 NATURE JI Nature PD APR 18 PY 1991 VL 350 IS 6319 BP 601 EP 604 DI 10.1038/350601a0 PG 4 WC Multidisciplinary Sciences SC Science & Technology - Other Topics GA FH112 UT WOS:A1991FH11200057 ER PT J AU GILLEN, G AF GILLEN, G TI THE USE OF KINETIC-ENERGY DISTRIBUTIONS TO DETERMINE THE RELATIVE CONTRIBUTIONS OF GAS-PHASE AND SURFACE FRAGMENTATION IN KILOELECTRONVOLT ION SPUTTERING OF A QUATERNARY AMMONIUM SALT SO INTERNATIONAL JOURNAL OF MASS SPECTROMETRY AND ION PROCESSES LA English DT Article ID HEAVY PARTICLE BOMBARDMENT; MASS-SPECTROMETRY; FIELD DESORPTION; MOLECULAR SIMS; SPECTRA; MECHANISMS AB Kinetic energy distributions have been used to evaluate the extent to which gas-phase decompositions contribute to the production of fragment ions in organic secondary ion mass spectra of a quaternary ammonium salt. Molecular kinetic energy distributions demonstrate that many fragment ions have a prominent gas-phase component which may account for as much as 50% of the observed fragment ion signal obtained in a double focussing mass spectrometer. RP GILLEN, G (reprint author), NATL INST STAND & TECHNOL,CTR ANALYT CHEM,GAITHERSBURG,MD 20899, USA. NR 17 TC 5 Z9 5 U1 0 U2 1 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0168-1176 J9 INT J MASS SPECTROM JI Int. J. Mass Spectrom. Ion Process. PD APR 15 PY 1991 VL 105 IS 3 BP 215 EP 224 DI 10.1016/0168-1176(91)87013-Q PG 10 WC Physics, Atomic, Molecular & Chemical; Spectroscopy SC Physics; Spectroscopy GA FJ861 UT WOS:A1991FJ86100003 ER PT J AU DOYLE, JR DOUGHTY, DA GALLAGHER, A AF DOYLE, JR DOUGHTY, DA GALLAGHER, A TI GERMANE DISCHARGE CHEMISTRY SO JOURNAL OF APPLIED PHYSICS LA English DT Article ID CHEMICAL VAPOR-DEPOSITION; FILM-PRODUCING RADICALS; AMORPHOUS-SILICON; GLOW-DISCHARGES; ELECTRON-IMPACT; SILANE; SI2H6; SIH4; GEH4; DECOMPOSITION AB The stable gas products of germane dissociation and subsequent radical reactions have been measured in pure germane glow discharges. Characteristics of the initial germane fragmentation are inferred from these data. The spatial distribution of discharge optical emission, and of film deposition on glass fibers, have also been measured. Finally, the surface reaction probability beta of depositing neutral radicals has been measured to be 0.61 +/- 0.09 on the grounded electrode. Major differences between germane and silane discharges occur in all these observables. Possible explanations of these differences are given, but much less chemical data exists for germane, thereby precluding definitive judgments. A probable cause of the normally much poorer semiconductor quality of a-Ge:H films, compared to a-Si:H, is suggested. This is based on the thermodynamics of the H2 release reaction at the growing surface. C1 NATL INST STAND & TECHNOL,JOINT INST LAB ASTROPHYS,BOULDER,CO 80309. UNIV COLORADO,BOULDER,CO 80309. NR 38 TC 26 Z9 26 U1 0 U2 5 PU AMER INST PHYSICS PI WOODBURY PA CIRCULATION FULFILLMENT DIV, 500 SUNNYSIDE BLVD, WOODBURY, NY 11797-2999 SN 0021-8979 J9 J APPL PHYS JI J. Appl. Phys. PD APR 15 PY 1991 VL 69 IS 8 BP 4169 EP 4177 DI 10.1063/1.348384 PN 1 PG 9 WC Physics, Applied SC Physics GA FL728 UT WOS:A1991FL72800001 ER PT J AU GULWADI, SM RAO, MV BERRY, AK SIMONS, DS CHI, PH DIETRICH, HB AF GULWADI, SM RAO, MV BERRY, AK SIMONS, DS CHI, PH DIETRICH, HB TI TRANSITION-METAL IMPLANTS IN IN0.53GA0.47AS SO JOURNAL OF APPLIED PHYSICS LA English DT Article ID SHALLOW P+ LAYER; COMPOUND SEMICONDUCTORS; DUAL IMPLANTS; CO-IMPLANT; GAAS; FE; INP; ACTIVATION; ALXGA1-XAS; ENERGY AB Single- and multiple-energy Fe, Cr, and V ions were implanted into InGaAs. Annealing of the implanted InGaAs samples caused a redistribution of the implanted atoms, as determined by secondary ion mass spectrometry. Coimplantation of Fe with P did not prevent this redistribution. A transport equation calculation of Fe-implantation-induced stoichiometric disturbances in InGaAs was done. The lattice quality of implanted InGaAs was investigated by photoreflectance measurements. Fe-implanted InGaAs has a resistivity close to the intrinsic limit, whereas Cr- and V-implanted InGaAs have a lower resistivity than the unimplanted material. C1 NATL INST STAND & TECHNOL,CTR ANALYT CHEM,GAITHERSBURG,MD 20899. USN,RES LAB,WASHINGTON,DC 20375. RP GULWADI, SM (reprint author), GEORGE MASON UNIV,DEPT ELECT & COMP ENGN,FAIRFAX,VA 22030, USA. NR 23 TC 19 Z9 19 U1 1 U2 6 PU AMER INST PHYSICS PI WOODBURY PA CIRCULATION FULFILLMENT DIV, 500 SUNNYSIDE BLVD, WOODBURY, NY 11797-2999 SN 0021-8979 J9 J APPL PHYS JI J. Appl. Phys. PD APR 15 PY 1991 VL 69 IS 8 BP 4222 EP 4227 DI 10.1063/1.348393 PN 1 PG 6 WC Physics, Applied SC Physics GA FL728 UT WOS:A1991FL72800010 ER PT J AU BENNETT, WR ENGLAND, CD PERSON, DC FALCO, CM AF BENNETT, WR ENGLAND, CD PERSON, DC FALCO, CM TI MAGNETIC-PROPERTIES OF PD/CO MULTILAYERS SO JOURNAL OF APPLIED PHYSICS LA English DT Article ID FILM LAYERED STRUCTURES; PERPENDICULAR ANISOTROPY; PD/FE MULTILAYERS; INTERFACE AB Measurements of the magnetic anisotropy of a series of Pd/Co multilayers grown by magnetically enhanced dc triode sputter deposition revealed an interface contribution of 0.53 erg/cm2 and a net volume anisotropy of -13.2 x 10(8) erg/cm3. A characteristic reduction of perpendicular anisotropy for ultrathin Co layers (< 4 angstrom) is explained by using a pair interaction model to evaluate a thickness dependence of the interface anisotropy. For Pd-Co interfaces with perfectly sharp composition modulation an interface anisotropy of 0.79 erg/cm2 is predicted. By modeling the magnetization behavior a domain-wall energy density of 2 +/- 0.5 erg/cm2 is obtained for Pd/Co (2 angstrom) multilayers with Pd thicknesses in the range of 4-20 angstrom. For perpendicular Pd75Co25 alloy thin films the same model gives domain-wall energy densities in the range of 1-2 erg/cm2. For ultrathin Co layers the interlayer Co-Co coupling range is approximately 20 angstrom. Temperature dependence of saturation magnetization of a Pd(11 angstrom)/Co(7.8 angstrom) multilayer demonstrates complete mixing of Pd and Co by 380-degrees-C. C1 UNIV ARIZONA,DEPT PHYS,TUCSON,AZ 85721. UNIV ARIZONA,CTR OPT SCI,TUCSON,AZ 85721. RP BENNETT, WR (reprint author), NATL INST STAND & TECHNOL,DIV SURFACE SCI,GAITHERSBURG,MD 20899, USA. NR 15 TC 35 Z9 35 U1 1 U2 5 PU AMER INST PHYSICS PI WOODBURY PA CIRCULATION FULFILLMENT DIV, 500 SUNNYSIDE BLVD, WOODBURY, NY 11797-2999 SN 0021-8979 J9 J APPL PHYS JI J. Appl. Phys. PD APR 15 PY 1991 VL 69 IS 8 BP 4384 EP 4390 DI 10.1063/1.348363 PN 1 PG 7 WC Physics, Applied SC Physics GA FL728 UT WOS:A1991FL72800033 ER PT J AU EKIN, JW BRAY, SL BAHN, WL AF EKIN, JW BRAY, SL BAHN, WL TI EFFECT OF TRANSVERSE STRESS ON THE CRITICAL CURRENT OF BRONZE-PROCESS AND INTERNAL-TIN NB3SN SO JOURNAL OF APPLIED PHYSICS LA English DT Note ID WIRES AB The effect of transverse stress on the critical current of two substantially different Nb3Sn superconductors, a bronze-process conductor and an internal-tin conductor, has been measured. Photomicrographs of the two conductors reveal a basic difference in their microstructure. The bronze-process conductor exhibits columnar grains that are radially oriented within the Nb3Sn filaments, while the grains of the internal-tin conductor are more equiaxed and randomly oriented. The radial orientation of the bronze-process grains defines an anisotropy between the axial and transverse directions that might account for the greater sensitivity of the critical current to transverse stress reported previously. The effect of transverse stress measured on the internal-tin conductor, however, is comparable to that of the bronze-process conductor. Thus, these data indicate that the transverse stress effect is not highly dependent on either grain morphology or fabrication process. From an engineering standpoint the similarity of the transverse stress effect for these two types of Nb3Sn superconductors represents an important simplification for setting first-order quantitative limits on the mechanical design of large superconducting magnets. RP EKIN, JW (reprint author), NATL INST STAND & TECHNOL,DIV ELECTROMAGNET TECHNOL,BOULDER,CO 80303, USA. NR 8 TC 18 Z9 18 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 APR 15 PY 1991 VL 69 IS 8 BP 4436 EP 4438 DI 10.1063/1.348372 PN 1 PG 3 WC Physics, Applied SC Physics GA FL728 UT WOS:A1991FL72800042 ER PT J AU VAJDA, F OTI, J PARDAVIHORVATH, M DELLATORRE, E SWARTZENDRUBER, LJ BENNETT, LH AF VAJDA, F OTI, J PARDAVIHORVATH, M DELLATORRE, E SWARTZENDRUBER, LJ BENNETT, LH TI EXPERIMENTAL-VERIFICATION OF A VECTOR PREISACH MODEL SO JOURNAL OF APPLIED PHYSICS LA English DT Article; Proceedings Paper CT 35TH ANNUAL CONF ON MAGNETISM AND MAGNETIC MATERIALS CY OCT 29-NOV 01, 1990 CL SAN DIEGO, CA SP AMER INST PHYS, IEEE, MAGNET SOC, AMER INST MIN MET & PETR ENGINEERS, MET SOC, USN, OFF NAVAL RES, AMER SOC TESTING & MAT, AMER PHYS SOC, AMER CERAM SOC AB A vector moving Preisach model has been developed that describes partially oriented particulate media by pseudoparticles, consisting of a distribution of several basic particles with various orientations of easy axes. The model uses switching modes calculated by a micromagnetic simulation of physical particles. In order to test this model, the angular dependence of the magnetic properties was measured by a vibrating sample magnetometer for several samples of commercial recording media that had different degrees of particle orientation. The experimental results are in good agreement with the orientation dependence of the squareness and coercivity, as predicted by the model. C1 NATL INST STAND & TECHNOL,GAITHERSBURG,MD 20899. RP VAJDA, F (reprint author), GEORGE WASHINGTON UNIV,WASHINGTON,DC 20052, USA. NR 7 TC 6 Z9 6 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 APR 15 PY 1991 VL 69 IS 8 BP 4502 EP 4504 DI 10.1063/1.348338 PN 2A PG 3 WC Physics, Applied SC Physics GA FL732 UT WOS:A1991FL73200013 ER PT J AU BEACH, RS BORCHERS, JA ERWIN, RW RHTNE, JJ MATHENY, A FLYNN, CP SALAMON, MB AF BEACH, RS BORCHERS, JA ERWIN, RW RHTNE, JJ MATHENY, A FLYNN, CP SALAMON, MB TI EFFECTS OF EPITAXIAL STRAIN IN ER/LU THIN-FILMS SO JOURNAL OF APPLIED PHYSICS LA English DT Article; Proceedings Paper CT 35TH ANNUAL CONF ON MAGNETISM AND MAGNETIC MATERIALS CY OCT 29-NOV 01, 1990 CL SAN DIEGO, CA SP AMER INST PHYS, IEEE, MAGNET SOC, AMER INST MIN MET & PETR ENGINEERS, MET SOC, USN, OFF NAVAL RES, AMER SOC TESTING & MAT, AMER PHYS SOC, AMER CERAM SOC ID MAGNETIC-STRUCTURE; ERBIUM AB A series of c-axis Er films ranging in thickness from 400 to 9500 angstrom were grown on lutetium base layers to investigate the effects of epitaxial growth on the magnetic properties of bulk erbium. Neutron diffraction studies show that the basal plane lattice parameter of Er approaches the smaller Lu value as the films are made thinner. Below T(N) the phase angles of the Er spin modulation are diminished from bulk Er values in the thinner films. For all but two 800-angstrom films, there is evidence from bulk magnetization and neutron data of a first-order transition to a conical ferromagnetic state, similar to bulk Er. These phenomena are compared to the properties of Er films grown on yttrium, whose basal plane spacing exceeds that of Er. In these systems the turn angles are greater than bulk and the ferromagnetic phase is suppressed. This contrasting behavior is consistent with predictions from a magnetoelastic energy model of epitaxial constraint developed to describe the Er/Y systems. C1 UNIV ILLINOIS,MAT RES LAB,URBANA,IL 61801. NATL INST STAND & TECHNOL,GAITHERSBURG,MD 20899. RP BEACH, RS (reprint author), UNIV ILLINOIS,DEPT PHYS,URBANA,IL 61801, USA. NR 10 TC 9 Z9 9 U1 0 U2 2 PU AMER INST PHYSICS PI WOODBURY PA CIRCULATION FULFILLMENT DIV, 500 SUNNYSIDE BLVD, WOODBURY, NY 11797-2999 SN 0021-8979 J9 J APPL PHYS JI J. Appl. Phys. PD APR 15 PY 1991 VL 69 IS 8 BP 4535 EP 4537 DI 10.1063/1.348351 PN 2A PG 3 WC Physics, Applied SC Physics GA FL732 UT WOS:A1991FL73200026 ER PT J AU KHAN, MR LEE, SY DUAN, SL PRESSESKY, JL HEIMAN, N SPELIOTIS, DE SCHEINFEIN, MR AF KHAN, MR LEE, SY DUAN, SL PRESSESKY, JL HEIMAN, N SPELIOTIS, DE SCHEINFEIN, MR TI CORRELATIONS OF MODULATION NOISE WITH MAGNETIC MICROSTRUCTURE AND INTERGRANULAR INTERACTIONS FOR COCRTA AND CONI THIN-FILM MEDIA SO JOURNAL OF APPLIED PHYSICS LA English DT Article; Proceedings Paper CT 35TH ANNUAL CONF ON MAGNETISM AND MAGNETIC MATERIALS CY OCT 29-NOV 01, 1990 CL SAN DIEGO, CA SP AMER INST PHYS, IEEE, MAGNET SOC, AMER INST MIN MET & PETR ENGINEERS, MET SOC, USN, OFF NAVAL RES, AMER SOC TESTING & MAT, AMER PHYS SOC, AMER CERAM SOC ID TRANSITION NOISE; RECORDING MEDIA; PERFORMANCE AB This paper reports on two thin-film media alloys Co86Cr12Ta2 and Co75Ni25 which have very different noise characteristics. The magnetic microstructure of these films was observed with scanning electron microscopy with polarization analysis (SEMPA). The variance (sigma-t2) of the magnetization across the transition region was calculated. The origin of anisotropy was determined by measuring the temperature coefficients of H(c) and M(s). The interaction strengths between grains, delta-M(H), were obtained from the measurement of the reverse demagnetization remanence M(d)(H) and the forward magnetization remanence M(r)(H). We found that the CoNi film showed a greater degree of interparticle interaction, which may explain the observed cross-bit linkages in SEMPA image, larger rms transition variation (sigma-t), and higher modulation noise. C1 ADV DEV CORP,BURLINGTON,MA 01803. NATL INST STAND & TECHNOL,GAITHERSBURG,MD 20899. RP KHAN, MR (reprint author), SEAGATE MAGNET,47001 BENICIA ST,FREMONT,CA 94538, USA. NR 12 TC 11 Z9 11 U1 0 U2 2 PU AMER INST PHYSICS PI WOODBURY PA CIRCULATION FULFILLMENT DIV, 500 SUNNYSIDE BLVD, WOODBURY, NY 11797-2999 SN 0021-8979 J9 J APPL PHYS JI J. Appl. Phys. PD APR 15 PY 1991 VL 69 IS 8 BP 4745 EP 4747 DI 10.1063/1.348267 PN 2A PG 3 WC Physics, Applied SC Physics GA FL732 UT WOS:A1991FL73200103 ER PT J AU SKANTHAKUMAR, S LYNN, JW PENG, JL LI, ZY AF SKANTHAKUMAR, S LYNN, JW PENG, JL LI, ZY TI ANTIFERROMAGNETIC ORDER OF CU IN SM2CUO4 SO JOURNAL OF APPLIED PHYSICS LA English DT Article; Proceedings Paper CT 35TH ANNUAL CONF ON MAGNETISM AND MAGNETIC MATERIALS CY OCT 29-NOV 01, 1990 CL SAN DIEGO, CA SP AMER INST PHYS, IEEE, MAGNET SOC, AMER INST MIN MET & PETR ENGINEERS, MET SOC, USN, OFF NAVAL RES, AMER SOC TESTING & MAT, AMER PHYS SOC, AMER CERAM SOC ID MAGNETIC PHASE-TRANSITIONS; SPIN CORRELATIONS; ND2CUO4; PR2CUO4; CRYSTAL AB Neutron diffraction techniques have been used to study the magnetic order of the Cu ions in a single crystal of Sm2CuO4. The measurements revealed the development of long-range magnetic order of the Cu moments at T(N) = 280 +/- 1 K, with a relatively simple antiferromagnetic configuration of spins as found in Nd2CuO4 and Pr2CuO4. However, the spin directions in Sm2CuO4 are rotated by 90-degrees from the spin directions in Nd2CuO4 and Pr2CuO4. The detailed spin structure can be either collinear or noncollinear, and in these tetragonal systems it is not possible to distinguish between them with the present neutron diffraction data on multidomain samples. Our measurements demonstrate that there are no spin reorientations below the Neel temperature, in contrast to the behavior found for Nd2CuO4. C1 NATL INST STANDARDS & TECHNOL,GAITHERSBURG,MD 20899. RP SKANTHAKUMAR, S (reprint author), UNIV MARYLAND,CTR SUPERCONDUCT RES,DEPT PHYS,COLLEGE PK,MD 20742, USA. NR 16 TC 41 Z9 41 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 APR 15 PY 1991 VL 69 IS 8 BP 4866 EP 4868 DI 10.1063/1.348206 PN 2A PG 3 WC Physics, Applied SC Physics GA FL732 UT WOS:A1991FL73200148 ER PT J AU BENNETT, LH SWARTZENDRUBER, LJ KAISER, DL AF BENNETT, LH SWARTZENDRUBER, LJ KAISER, DL TI MEISSNER, SHIELDING, AND FLUX LOSS BEHAVIOR IN SINGLE-CRYSTAL YBA2CU3O6+X SO JOURNAL OF APPLIED PHYSICS LA English DT Article; Proceedings Paper CT 35TH ANNUAL CONF ON MAGNETISM AND MAGNETIC MATERIALS CY OCT 29-NOV 01, 1990 CL SAN DIEGO, CA SP AMER INST PHYS, IEEE, MAGNET SOC, AMER INST MIN MET & PETR ENGINEERS, MET SOC, USN, OFF NAVAL RES, AMER SOC TESTING & MAT, AMER PHYS SOC, AMER CERAM SOC ID GROWTH AB Meissner effect measurements were performed on a nearly cubic single crystal of YBCO, which exhibited a predominant (110) twin habit, by cooling the crystal from above T(c) to 10 K in an applied field H of 10 Oe. A significant difference was observed for H applied parallel and perpendicular to the c axis, but little difference could be seen for H perpendicular and parallel to the twin boundaries. After cooling from above T(c) in 10 Oe to 10 K, the field was reduced to zero. The magnetization changed sign, increasing by approximately 15 G, which is the value expected for complete flux expulsion by a crystal of this geometry. Magnetization measurements were then made as the temperature was raised back to 100 K. Again, there is a significant difference for the results with H parallel and perpendicular to the c axis, especially above 60 K, with only a small (but possibly meaningful) difference for perpendicular and parallel to the twin boundaries. RP BENNETT, LH (reprint author), NATL INST STANDARDS & TECHNOL,GAITHERSBURG,MD 20899, USA. NR 6 TC 0 Z9 0 U1 0 U2 0 PU AMER INST PHYSICS PI WOODBURY PA CIRCULATION FULFILLMENT DIV, 500 SUNNYSIDE BLVD, WOODBURY, NY 11797-2999 SN 0021-8979 J9 J APPL PHYS JI J. Appl. Phys. PD APR 15 PY 1991 VL 69 IS 8 BP 4889 EP 4890 DI 10.1063/1.348214 PN 2A PG 2 WC Physics, Applied SC Physics GA FL732 UT WOS:A1991FL73200156 ER PT J AU MICELI, PF TARASCON, JM HULL, GW REMSCHNIG, K MCKINNON, WR TELPIS, E LEPAGE, Y MCALISTER, SP PLEIZIER, G RHYNE, JJ NEUMANN, DA AF MICELI, PF TARASCON, JM HULL, GW REMSCHNIG, K MCKINNON, WR TELPIS, E LEPAGE, Y MCALISTER, SP PLEIZIER, G RHYNE, JJ NEUMANN, DA TI 2-DIMENSIONAL MODULATED FERRIMAGNETIC SYSTEMS SO JOURNAL OF APPLIED PHYSICS LA English DT Meeting Abstract C1 NATL RES COUNCIL CANADA,OTTAWA K1A 0R9,ONTARIO,CANADA. NATL INST STANDARDS & TECHNOL,GAITHERSBURG,MD 20899. RP MICELI, PF (reprint author), BELLCORE,RED BANK,NJ 07701, USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU AMER INST PHYSICS PI WOODBURY PA CIRCULATION FULFILLMENT DIV, 500 SUNNYSIDE BLVD, WOODBURY, NY 11797-2999 SN 0021-8979 J9 J APPL PHYS JI J. Appl. Phys. PD APR 15 PY 1991 VL 69 IS 8 BP 4903 EP 4903 DI 10.1063/1.348950 PN 2A PG 1 WC Physics, Applied SC Physics GA FL732 UT WOS:A1991FL73200164 ER PT J AU SHULL, RD RITTER, JJ SWARTZENDRUBER, LJ AF SHULL, RD RITTER, JJ SWARTZENDRUBER, LJ TI CHANGE IN MAGNETIC STATE OF FE + SILICA-GEL NANOCOMPOSITES DUE TO LOW-TEMPERATURE TREATMENT IN AMMONIA SO JOURNAL OF APPLIED PHYSICS LA English DT Article; Proceedings Paper CT 35TH ANNUAL CONF ON MAGNETISM AND MAGNETIC MATERIALS CY OCT 29-NOV 01, 1990 CL SAN DIEGO, CA SP AMER INST PHYS, IEEE, MAGNET SOC, AMER INST MIN MET & PETR ENGINEERS, MET SOC, USN, OFF NAVAL RES, AMER SOC TESTING & MAT, AMER PHYS SOC, AMER CERAM SOC ID SILICA AB Homogeneous gelled composites of iron and silica containing 11-40 wt. % Fe were prepared by room temperature polymerization of aqueous solutions of ferric nitrate, tetraethoxysilane, and ethanol (with an HF catalyst). Previous electron microscopy, x-ray diffraction, and Mossbauer effect data showed these bulk materials are comprised of nanometer-sized regions of iron compounds embedded in a silica gel matrix. They were also all paramagnetic below 300 K. Here the effect on the magnetic state of these nanocomposites following a low temperature (T < 400-degrees-C) treatment in 1 atm of ammonia (after a prior anneal in 1 atm of hydrogen) is presented, along with the dependence on the H-2 pretreatment. In all cases the room temperature Mossbauer spectra for the material in the NH3-treated and H-2-pretreated conditions were similar. However, when treated in H-2 at 770-degrees-C (2 h) the Mossbauer spectra also contained a significant component having a large isomer shift (approximately 1.3 mm/s) and quadrupole splitting (approximately 3.2 mm/s). This material was also slightly ferromagnetic at all temperatures below 300 K. For materials pretreated in hydrogen below 400-degrees-C, a threefold enhancement in the magnetic susceptibility was measured following treatment in ammonia. In addition, both the field and temperature dependence of the susceptibility indicated the presence of spin-glass behavior at 10 K for NH3-treated samples containing up to 40% Fe. At room temperature, these latter ammonia-treated nanocomposites were either superparamagnetic (Fe contents, C(Fe), up to 25%) or ferromagnetic (C(Fe) > 25%). RP SHULL, RD (reprint author), NATL INST STAND & TECHNOL,GAITHERSBURG,MD 20899, USA. RI Shull, Robert/F-5971-2013 NR 6 TC 27 Z9 27 U1 0 U2 2 PU AMER INST PHYSICS PI WOODBURY PA CIRCULATION FULFILLMENT DIV, 500 SUNNYSIDE BLVD, WOODBURY, NY 11797-2999 SN 0021-8979 J9 J APPL PHYS JI J. Appl. Phys. PD APR 15 PY 1991 VL 69 IS 8 BP 5144 EP 5146 DI 10.1063/1.348104 PN 2A PG 3 WC Physics, Applied SC Physics GA FL732 UT WOS:A1991FL73200256 ER PT J AU COCHRAN, JF MUIR, WB RUDD, JM HEINRICH, B CELINSKI, Z LETRAN, TT SCHWARZACHER, W BENNETT, W EGELHOFF, WF AF COCHRAN, JF MUIR, WB RUDD, JM HEINRICH, B CELINSKI, Z LETRAN, TT SCHWARZACHER, W BENNETT, W EGELHOFF, WF TI MAGNETIC ANISOTROPIES IN ULTRATHIN FCC FE(001) FILMS GROWN ON CU(001) SUBSTRATES SO JOURNAL OF APPLIED PHYSICS LA English DT Article; Proceedings Paper CT 35TH ANNUAL CONF ON MAGNETISM AND MAGNETIC MATERIALS CY OCT 29-NOV 01, 1990 CL SAN DIEGO, CA SP AMER INST PHYS, IEEE, MAGNET SOC, AMER INST MIN MET & PETR ENGINEERS, MET SOC, USN, OFF NAVAL RES, AMER SOC TESTING & MAT, AMER PHYS SOC, AMER CERAM SOC ID BRILLOUIN LIGHT-SCATTERING; FERROMAGNETIC-FILMS; SUPERLATTICES; SANDWICHES; MAGNONS; BCC AB Brillouin light scattering and ferromagnetic resonance have been used to measure the magnetic-field dependence of the magnon frequency at room temperature for three-monolayer-thick films of fcc Fe(001) grown by means of molecular-beam epitaxy on Cu(001) substrates. These films exhibit a strong uniaxial magnetic anisotropy which causes the magnetization to be oriented perpendicular to the film plane in zero applied field. Four specimens were grown on copper substrates prepared using a chemical polishing technique which avoided the use of abrasives: This treatment greatly reduced the density of etch pits on the copper surface. The uniaxial anisotropies found for these specimens were very consistent and comparable to that previously measured for the best film grown on a mechanically polished copper substrate. There is evidence that substrate smoothness is improved and, hence, that the uniaxial anisotropy is increased when the substrate is covered with a few monolayers of epitaxial copper before the iron films are grown. C1 NATL INST STAND & TECHNOL,DIV SURFACE SCI,GAITHERSBURG,MD 20899. RP COCHRAN, JF (reprint author), SIMON FRASER UNIV,DEPT PHYS,BURNABY V5A 1S6,BC,CANADA. NR 19 TC 11 Z9 11 U1 0 U2 2 PU AMER INST PHYSICS PI WOODBURY PA CIRCULATION FULFILLMENT DIV, 500 SUNNYSIDE BLVD, WOODBURY, NY 11797-2999 SN 0021-8979 J9 J APPL PHYS JI J. Appl. Phys. PD APR 15 PY 1991 VL 69 IS 8 BP 5206 EP 5208 DI 10.1063/1.348076 PN 2A PG 3 WC Physics, Applied SC Physics GA FL732 UT WOS:A1991FL73200282 ER PT J AU BENNETT, LH LASHMORE, DS SWARTZENDRUBER, LJ SOLTANI, E BEAUCHAMP, CE AF BENNETT, LH LASHMORE, DS SWARTZENDRUBER, LJ SOLTANI, E BEAUCHAMP, CE TI MAGNETIC-PROPERTIES OF ELECTROCHEMICALLY PRODUCED CU-X (X=NI, FE, AND CO) ARTIFICIAL SUPERLATTICES SO JOURNAL OF APPLIED PHYSICS LA English DT Meeting Abstract RP BENNETT, LH (reprint author), NATL INST STAND & TECHNOL,GAITHERSBURG,MD 20899, USA. NR 2 TC 0 Z9 0 U1 0 U2 0 PU AMER INST PHYSICS PI WOODBURY PA CIRCULATION FULFILLMENT DIV, 500 SUNNYSIDE BLVD, WOODBURY, NY 11797-2999 SN 0021-8979 J9 J APPL PHYS JI J. Appl. Phys. PD APR 15 PY 1991 VL 69 IS 8 BP 5319 EP 5319 DI 10.1063/1.348063 PN 2A PG 1 WC Physics, Applied SC Physics GA FL732 UT WOS:A1991FL73200323 ER PT J AU UNGURIS, J HART, MW SCHEINFEIN, MR CELOTTA, RJ PIERCE, DT AF UNGURIS, J HART, MW SCHEINFEIN, MR CELOTTA, RJ PIERCE, DT TI SEMPA MEASUREMENTS OF MAGNETIC MICROSTRUCTURE IN ULTRATHIN FILMS SO JOURNAL OF APPLIED PHYSICS LA English DT Meeting Abstract RP UNGURIS, J (reprint author), NATL INST STAND & TECHNOL, GAITHERSBURG, MD 20899 USA. RI Unguris, John/J-3989-2014 NR 2 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 APR 15 PY 1991 VL 69 IS 8 BP 6096 EP 6096 DI 10.1063/1.347778 PN 2B PG 1 WC Physics, Applied SC Physics GA FL735 UT WOS:A1991FL73500284 ER PT J AU KLOSOWSKI, P GIEBULTOWICZ, TM RHYNE, JJ SAMARTH, N LUO, H FURDYNA, JK AF KLOSOWSKI, P GIEBULTOWICZ, TM RHYNE, JJ SAMARTH, N LUO, H FURDYNA, JK TI ANTIFERROMAGNETIC ORDERING IN MNSE/ZNSE MULTILAYERS SO JOURNAL OF APPLIED PHYSICS LA English DT Article; Proceedings Paper CT 35TH ANNUAL CONF ON MAGNETISM AND MAGNETIC MATERIALS CY OCT 29-NOV 01, 1990 CL SAN DIEGO, CA SP AMER INST PHYS, IEEE, MAGNET SOC, AMER INST MIN MET & PETR ENGINEERS, MET SOC, USN, OFF NAVAL RES, AMER SOC TESTING & MAT, AMER PHYS SOC, AMER CERAM SOC ID DILUTED MAGNETIC SEMICONDUCTORS AB We report neutron diffraction studies of zinc-blende strained MnSe/ZnSe superlattices. Such systems are examples of a fcc Heisenberg antiferromagnet of the third kind. The results show clearly long-range order in the MnSe layer plane, and no magnetic coupling across the passive layers. The strain affects the relative domain population. Measurements of the diffracted intensity versus T show that the AF phase transition in the MnSe layers is of second order with T(M) = 107 +/- 5 K. C1 NATL INST STAND & TECHNOL,GAITHERSBURG,MD 20899. RP KLOSOWSKI, P (reprint author), UNIV NOTRE DAME,NOTRE DAME,IN 46556, USA. RI Samarth, Nitin/C-4475-2014 OI Samarth, Nitin/0000-0003-2599-346X NR 12 TC 17 Z9 17 U1 1 U2 5 PU AMER INST PHYSICS PI WOODBURY PA CIRCULATION FULFILLMENT DIV, 500 SUNNYSIDE BLVD, WOODBURY, NY 11797-2999 SN 0021-8979 J9 J APPL PHYS JI J. Appl. Phys. PD APR 15 PY 1991 VL 69 IS 8 BP 6109 EP 6111 PN 2B PG 3 WC Physics, Applied SC Physics GA FL735 UT WOS:A1991FL73500287 ER PT J AU BAND, YB JULIENNE, PS AF BAND, YB JULIENNE, PS TI DENSITY-MATRIX CALCULATION OF POPULATION TRANSFER BETWEEN VIBRATIONAL LEVELS OF NA-2 BY STIMULATED RAMAN-SCATTERING WITH TEMPORALLY SHIFTED LASER-BEAMS SO JOURNAL OF CHEMICAL PHYSICS LA English DT Article ID MULTILEVEL SYSTEMS; SPECTROSCOPY; DISSOCIATION; DYNAMICS; STATE AB We compare the results of full density matrix calculations with recently reported experimental results describing the population transfer in Na2 using Raman scattering with the fundamental laser beam temporally shifted relative to the Stokes laser beam. Our calculations confirm the conclusion that almost total transfer of the population into the terminal level of the Raman transition can be achieved when the laser frequencies are tuned to resonance and the fundamental laser beam is temporally delayed relative to the Stokes shifted laser beam but still partially overlapping it. We analyze our results when the frequencies of the lasers are tuned off-resonance as a function of the Rabi frequencies and the detuning, and compare with experimental and theoretical results. The alignment of the terminal level as a function of time displacement of the Stokes and pump beams is predicted. C1 NATL INST STAND & TECHNOL,DIV MOLEC PHYS,GAITHERSBURG,MD 20899. RP BAND, YB (reprint author), BEN GURION UNIV NEGEV,DEPT CHEM,IL-84105 BEER SHEVA,ISRAEL. RI Julienne, Paul/E-9378-2012 OI Julienne, Paul/0000-0002-5494-1442 NR 19 TC 41 Z9 41 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 APR 15 PY 1991 VL 94 IS 8 BP 5291 EP 5298 DI 10.1063/1.460513 PG 8 WC Chemistry, Physical; Physics, Atomic, Molecular & Chemical SC Chemistry; Physics GA FH076 UT WOS:A1991FH07600005 ER PT J AU FORD, RS SUENRAM, RD FRASER, GT LOVAS, FJ LEOPOLD, KR AF FORD, RS SUENRAM, RD FRASER, GT LOVAS, FJ LEOPOLD, KR TI ROTATIONAL SPECTRUM AND STRUCTURE OF THE COMPLEX AR-CH3CN SO JOURNAL OF CHEMICAL PHYSICS LA English DT Article ID VANDERWAALS COMPLEX; MICROWAVE SPECTROSCOPY; INTERNAL-ROTATION; HCN DIMER; AR-HCN; RADIOFREQUENCY; CYANIDE AB The microwave spectrum of the weakly bound complex Ar-CH3CN has been observed using a pulsed-nozzle Fourier-transform microwave spectrometer. The spectrum is characteristic of an asymmetric rotor with nearly free internal rotation of the methyl group. Spectroscopic constants for the ground internal rotor state, in megaHertz, are A = 9323.7769(22), B + C = 3439.5578(15), B-C = 326.6860(12), DELTA-J = 0.013 361(14), DELTA-JK = 0.226 143(99), DELTA-K = -0.209 86(77), delta-J = 0.002 532(11), eqQ(aa) = 2.0542(59), eqQ(bb) - eqQ(cc) = -6.2856(86). The complex has a T-shaped geometry in which the acetonitrile axis is nearly perpendicular to the line joining the centers of mass of the monomers, and the methyl group undergoes nearly free internal rotation. The center-of-mass separation is 3.6505(7) angstrom and the dipole moment component along the b inertial axis of the complex is 3.802(5) D. The latter is quantitatively accounted for by the sum of the monomer permanent moment and the dipole-induced dipole in the argon. C1 UNIV MINNESOTA,DEPT CHEM,MINNEAPOLIS,MN 55455. NATL INST STAND & TECHNOL,DIV MOLEC PHYS,GAITHERSBURG,MD 20899. NR 21 TC 11 Z9 11 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 APR 15 PY 1991 VL 94 IS 8 BP 5306 EP 5312 DI 10.1063/1.460515 PG 7 WC Chemistry, Physical; Physics, Atomic, Molecular & Chemical SC Chemistry; Physics GA FH076 UT WOS:A1991FH07600007 ER PT J AU JOHNSON, RD HUDGENS, JW AF JOHNSON, RD HUDGENS, JW TI MULTIPHOTON IONIZATION OF SIH3 AND SID3 RADICALS .2. 3 PHOTON RESONANCE-ENHANCED SPECTRA OBSERVED BETWEEN 450 AND 610 NM SO JOURNAL OF CHEMICAL PHYSICS LA English DT Article ID TIME-REVERSAL INVARIANCE; GAS-PHASE; POLARIZATION DEPENDENCE; ELECTRONIC-SPECTRUM; 2-PHOTON ABSORPTION; DIATOMIC-MOLECULES; METHYL RADICALS; RYDBERG STATES; LINE STRENGTHS; TOP MOLECULES AB The electronic spectra of silyl radicals, SiH3 and SiD3, were observed between 450 and 610 nm (49 200-65 200 cm-1) by resonance enhanced multiphoton ionization (REMPI) spectroscopy. The spectra were produced through a 3 + 1 REMPI mechanism. Spectra of four new planar Rydberg states were observed and assigned. In SiH3 the observed states and spectroscopic constants are D approximately 2 A 1' (3d):T0 = 49 787(30), omega-2 = 810(31) cm-1; I approximately' (4d): T0 = 56 253(30), omega-2 = 814(25) cm-1; J approximately' (4d):T0 = 57 726(30), omega-2 = 835(26) cm-1; and L approximately (5d):T0 = 59 615(30) cm-1, omega-2 = 839(26) cm-1. In SiD3 the observed states and spectroscopic constants are D approximately 2 A 1' (3d):T0 = 49 685(30), omega-2 = 600(28) cm-1; I approximately' (4d):T0 = 56 205(30), omega-2 = 600(17) cm-1; and J approximately' (4d):T0 = 57 840(30), omega-2 = 603(20) cm-1. The differences between 2 + 1 and 3 + 1 REMPI spectra are explained by a DELTA-l rule, where l is the electronic orbital angular momentum. The H approximately, K approximately, and N approximately states observed in the 2 + 1 REMPI spectrum of SiD3 spectrum and reported in J. Chem. Phys. 91, 3340 (1989) are reassigned as the H approximately 2 E' (4p), K approximately 2 E' (4f), and N approximately 2 E' (5f). RP JOHNSON, RD (reprint author), NATL INST STAND & TECHNOL,DIV CHEM KINET & THERMODYNAM,GAITHERSBURG,MD 20899, USA. NR 39 TC 17 Z9 17 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 APR 15 PY 1991 VL 94 IS 8 BP 5331 EP 5340 DI 10.1063/1.460518 PG 10 WC Chemistry, Physical; Physics, Atomic, Molecular & Chemical SC Chemistry; Physics GA FH076 UT WOS:A1991FH07600010 ER PT J AU HANSEN, DV MAUL, GA AF HANSEN, DV MAUL, GA TI ANTICYCLONIC CURRENT RINGS IN THE EASTERN TROPICAL PACIFIC-OCEAN SO JOURNAL OF GEOPHYSICAL RESEARCH-OCEANS LA English DT Article ID WARM-CORE RING; GULF-STREAM RING; NORTH-ATLANTIC; MEXICO; EDDIES; TEHUANTEPEC; SATELLITE; EVOLUTION; PAPAGAYO; VORTICES AB Observations from satellite-tracked drifting buoys, expendable bathythermograph and conductivity-temperature-depth data, and Geosat altimeter data are used to describe anticyclonic eddies that occur in small numbers off the Pacific coast of Central America. These eddies are similar in many respects to the well-known warm-core rings that are observed north of the Gulf Stream off the Atlantic coast of North America, except that they occur in an environment that also is warm, and they contain considerably greater kinetic energy. It is hypothesized that they are formed as a result of conservation of potential vorticity when the North Equatorial Countercurrent (NECC) turns northward upon approaching the eastern boundary during its autumnal maximum. The rings so formed have a strongly nonlinear character which causes them to propagate westward between 9-degrees-N and 14-degrees-N with a speed in excess of that of long Rossby waves. Due to a relatively small available potential energy content, these rings have a dissipation time scale of about 6 months and perhaps end by collision with and reabsorbtion into the NECC. The rings account for the observed enhancement of surface kinetic energy, and probably for the seaward transport of waters enriched in copper. C1 UNIV MIAMI, COOPERAT INST MARINE & ATMOSPHER STUDIES, MIAMI, FL 33152 USA. RP NOAA, ATLANTIC OCEANOG & METEOROL LAB, 4301 RICKENBACKER CAUSEWAY, MIAMI, FL 33149 USA. RI Maul, George/M-1629-2015 OI Maul, George/0000-0001-8413-7853 NR 48 TC 48 Z9 48 U1 0 U2 2 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 2169-9275 EI 2169-9291 J9 J GEOPHYS RES-OCEANS JI J. Geophys. Res.-Oceans PD APR 15 PY 1991 VL 96 IS C4 BP 6965 EP 6979 DI 10.1029/91JC00096 PG 15 WC Oceanography SC Oceanography GA FH461 UT WOS:A1991FH46100002 ER PT J AU DOUGLAS, BC AF DOUGLAS, BC TI GLOBAL SEA-LEVEL RISE SO JOURNAL OF GEOPHYSICAL RESEARCH-OCEANS LA English DT Article AB Published values for the long-term, global mean sea level rise determined from tide gauge records exhibit considerable scatter, from about 1 mm to 3 mm/yr. This disparity is not attributable to instrument error; long-term trends computed at adjacent sites often agree to within a few tenths of a millimeter per year. Instead, the differing estimates of global sea level rise appear to be in large part due to authors' using data from gauges located at convergent tectonic plate boundaries, where changes of land elevation give fictitous sea level trands. In addition, virtually all gauges undergo subsidence or uplift due to postglacial rebound (PGR) from the last deglaciation at a rate comparable to or greater than the secular rise of sea level. Modeling PGR by the ICE-3G model of Tushingham and Peltier (1991) and avoiding tide gauge records in areas of converging tectonic plates produces a highly consistent set of long sea level records. The value for mean sea level rise obtained from a global set of 21 such stations in nine oceanic regions with an average record length of 76 years during the period 1880-1980 is 1.8 mm/yr +/- 0.1. This result provides confidence that carefully selected long tide gauge records measure the same underlying trend of sea level and that many old tide gauge records are of very high quality. RP DOUGLAS, BC (reprint author), NOAA,NATL OCEAN SERV,GEODET RES & DEV LAB,OFF CHARTING & GEODET SERV,ROCKVILLE,MD 20852, USA. NR 13 TC 329 Z9 343 U1 3 U2 35 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 SN 0148-0227 J9 J GEOPHYS RES-OCEANS JI J. Geophys. Res.-Oceans PD APR 15 PY 1991 VL 96 IS C4 BP 6981 EP 6992 DI 10.1029/91JC00064 PG 12 WC Oceanography SC Oceanography GA FH461 UT WOS:A1991FH46100003 ER PT J AU HEBERT, D MOUM, JN PAULSON, CA CALDWELL, DR CHERESKIN, TK MCPHADEN, MJ AF HEBERT, D MOUM, JN PAULSON, CA CALDWELL, DR CHERESKIN, TK MCPHADEN, MJ TI THE ROLE OF THE TURBULENT STRESS DIVERGENCE IN THE EQUATORIAL PACIFIC ZONAL MOMENTUM BALANCE SO JOURNAL OF GEOPHYSICAL RESEARCH-OCEANS LA English DT Article ID OCEAN; 110-DEGREES-W; CIRCULATION; GRADIENT; SHEAR AB From a comprehensive set of upper ocean measurements made during a moderate El Nino in boreal spring 1987, we reassess the role of turbulence in transporting momentum vertically at the equator. An examination of the terms in the vertically integrated zonal momentum equations indicates that on short time scales the zonal pressure gradient is not balanced by the surface wind stress despite an apparent balance of these terms on longer (seasonal) time scales. The vertical redistribution of zonal momentum is complex. The strength of the wind determines both the magnitude and, likely, the mechanisms of momentum transport between the surface and the core of the undercurrent. During low wind conditions in April 1987 the turbulent stress divergence was significantly different in magnitude and vertical structure from that found during strong winds in November 1984. In November 1984 the turbulent stress divergence was much too large above 40 m to balance the residual term in the zonal momentum budget of Bryden and Brady (1985, 1989) and decayed exponentially with depth from the wind stress value at the surface. In April 1987 the turbulent stress divergence was smaller than that required by Bryden and Brady and decayed linearly from the surface wind stress. For a proper comparison with Bryden and Brady's zonal momentum balance, it is necessary to determine the annual average turbulent stress divergence. C1 UNIV CALIF SAN DIEGO,SCRIPPS INST OCEANOG,LA JOLLA,CA 92093. NOAA,PACIFIC MARINE ENVIRONM LAB,SEATTLE,WA 98115. RP HEBERT, D (reprint author), OREGON STATE UNIV,COLL OCEANOG,CORVALLIS,OR 97331, USA. RI Moum, James/A-1880-2012; McPhaden, Michael/D-9799-2016 NR 24 TC 31 Z9 31 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-OCEANS JI J. Geophys. Res.-Oceans PD APR 15 PY 1991 VL 96 IS C4 BP 7127 EP 7136 DI 10.1029/91JC00271 PG 10 WC Oceanography SC Oceanography GA FH461 UT WOS:A1991FH46100015 ER PT J AU LATHABAI, S RODEL, J DABBS, T LAWN, BR AF LATHABAI, S RODEL, J DABBS, T LAWN, BR TI FRACTURE-MECHANICS MODEL FOR SUBTHRESHOLD INDENTATION FLAWS .1. EQUILIBRIUM FRACTURE SO JOURNAL OF MATERIALS SCIENCE LA English DT Article ID ELASTIC-PLASTIC INDENTATION; SODA-LIME GLASS; RESIDUAL CONTACT STRESSES; CRACK INITIATION; DYNAMIC FATIGUE; BRITTLE MATERIALS; STRENGTH; FIBERS; DEFORMATION; CERAMICS AB A fracture mechanics model for subthreshold indentation flaws is described. The model describes the initiation and extension of a microcrack from a discrete deformation-induced shear "fault" (shear crack) within the contact zone. A stress-intensity factor analysis for the microcrack extension in residual-contact and applied-stress fields is used in conjunction with appropriate fracture conditions, equilibrium in Part I and non-equilibrium in Part II, to determine critical instability configurations. In Part I, the K-field relations are used in conjunction with the Griffith requirements for crack equilibrium in essentially inert environments to determine: (i) the critical indentation size (or load) for spontaneous radial crack pop-in from a critical shear fault under the action of residual stresses alone; (ii) the inert strengths of surfaces with subthreshold or postthreshold flaws. The theory is fitted to literature data for silicate glasses. These fits are used to "calibrate" dimensionless parameters in the fracture mechanics expressions, for later use in Part II. The universality of the analysis in its facility to predict the main features of crack initiation and propagation in residual and applied fields will be demonstrated. Special emphasis is placed on the capacity to account for the significant increase in strength (and associated scatter) observed on passing from the postthreshold to the subthreshold domain. C1 LEHIGH UNIV,DEPT MAT SCI & ENGN,BETHLEHEM,PA 18015. RP LATHABAI, S (reprint author), NATL INST STAND & TECHNOL,DIV CERAM,GAITHERSBURG,MD 20899, USA. NR 39 TC 37 Z9 38 U1 1 U2 4 PU CHAPMAN HALL LTD PI LONDON PA 2-6 BOUNDARY ROW, LONDON, ENGLAND SE1 8HN SN 0022-2461 J9 J MATER SCI JI J. Mater. Sci. PD APR 15 PY 1991 VL 26 IS 8 BP 2157 EP 2168 DI 10.1007/BF00549183 PG 12 WC Materials Science, Multidisciplinary SC Materials Science GA FH280 UT WOS:A1991FH28000027 ER PT J AU MATROSOV, SY AF MATROSOV, SY TI THEORETICAL-STUDY OF RADAR POLARIZATION PARAMETERS OBTAINED FROM CIRRUS CLOUDS SO JOURNAL OF THE ATMOSPHERIC SCIENCES LA English DT Article ID SCATTERING; RAIN AB A theoretical investigation of radar polarization parameters that characterize cloud ice backscattering is presented. The parameters considered were those commonly used in radar polarimetrics such as differential reflectivity (Z(DR)), linear depolarization ratio (LDR), circular depolarization ratio (CDR), intrinsic degree of orientation (ORTT) as well as conventional reflectivities. Experimental data on the shapes of ice crystals and their orientations are taken into account. Results suggest that prolate-shaped scatterers can be distinguished from those having oblate shapes by analyzing the depolarization ratio dependence on the elevation angle. Calculations suggest that circular polarization parameters provide stronger signals in a cross-polar channel and also show a lesser dependence on scatterer orientation in comparison with linear polarization parameters. Propagation effects do not significantly affect the polarization parameters for equivalent water contents and cloud thicknesses that are typical for cirrus clouds. Differential phase shift that might be observed in cirrus clouds is relatively small. Finally, equivalent reflectivity factors are analyzed for several ice particle types as a function of their major axis. Reflectivity dependence on particle shapes is demonstrated, and comments on the possibility of making approximate estimates of cloud particle sizes are given. RP MATROSOV, SY (reprint author), NOAA,ENVIRONM RES LAB,WAVE PROPAGAT LAB,RADAR METEOROL GRP,325 BROADWAY,BOULDER,CO 80303, USA. NR 15 TC 41 Z9 42 U1 0 U2 1 PU AMER METEOROLOGICAL SOC PI BOSTON PA 45 BEACON ST, BOSTON, MA 02108-3693 SN 0022-4928 J9 J ATMOS SCI JI J. Atmos. Sci. PD APR 15 PY 1991 VL 48 IS 8 BP 1062 EP 1070 DI 10.1175/1520-0469(1991)048<1062:TSORPP>2.0.CO;2 PG 9 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA FL200 UT WOS:A1991FL20000004 ER PT J AU LEE, SY HELD, IM AF LEE, SY HELD, IM TI SUBCRITICAL INSTABILITY AND HYSTERESIS IN A 2-LAYER MODEL SO JOURNAL OF THE ATMOSPHERIC SCIENCES LA English DT Article ID BAROCLINIC WAVES AB A two-layer quasi-geostrophic model forced by surface friction and radiative relaxation to a jetlike wind profile can exist in either a wave-free state or in a finite-amplitude wave state, over a substantial region of the model's parameter space. The friction on the lower layer must be much stronger than the thermal relaxation, and the upper layer must be nearly inviscid, for this behavior to be observed. Consistent with this behavior, weakly unstable waves are found that do not stabilize the flow; instead, their growth rate increases with wave amplitude. We attempt to provide a physical explanation for this behavior in terms of 1) the competition between the stabilizing effect of the lower-layer potential vorticity fluxes and the destabilizing effect of nonlinear critical layer formation associated with the upper-layer fluxes, and 2) the tendency of surface drag to restore the vertical shear at the center of the jet by damping the surface westerlies generated by the baroclinic instability. C1 PRINCETON UNIV,ATMOSPHER & OCEAN SCI PROGRAM,PRINCETON,NJ 08544. RP LEE, SY (reprint author), PRINCETON UNIV,NOAA,GEOPHYS FLUID DYNAM LAB,POB 308,PRINCETON,NJ 08542, USA. NR 12 TC 17 Z9 17 U1 0 U2 1 PU AMER METEOROLOGICAL SOC PI BOSTON PA 45 BEACON ST, BOSTON, MA 02108-3693 SN 0022-4928 J9 J ATMOS SCI JI J. Atmos. Sci. PD APR 15 PY 1991 VL 48 IS 8 BP 1071 EP 1077 DI 10.1175/1520-0469(1991)048<1071:SIAHIA>2.0.CO;2 PG 7 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA FL200 UT WOS:A1991FL20000005 ER PT J AU HASEGAWA, H SAKURAI, S TAKENAKA, M HASHIMOTO, T HAN, CC AF HASEGAWA, H SAKURAI, S TAKENAKA, M HASHIMOTO, T HAN, CC TI SMALL-ANGLE NEUTRON-SCATTERING AND LIGHT-SCATTERING-STUDIES ON THE MISCIBILITY OF PROTONATED POLYISOPRENE DEUTERATED POLYBUTADIENE BLENDS SO MACROMOLECULES LA English DT Article ID INTEGRAL-EQUATION THEORY; STAGE SPINODAL DECOMPOSITION; BINARY POLYMER MIXTURE; POLYVINYL METHYL-ETHER); POLYSTYRENE; MELTS; DYNAMICS; FLUCTUATIONS; EQUILIBRIUM; BEHAVIOR AB Binary mixtures of protonated polyisoprene and deuterated polybutadiene with particular microstructures exhibit an LCST-type phase behavior. Small-angle neutron scattering (SANS) and time-resolved small-angle light scattering (SALS) techniques were employed to study the static and dynamic phase behavior of the mixtures. From the static study by SANS, binary interaction parameters, chi, and the phase diagram were obtained. The spinodal temperature at the critical blend composition obtained by the analysis of SANS profiles from the single-phase state was in good agreement with that obtained by the time-resolved SALS measurements. The component polymers are prepared by living anionic polymerization and hence have well-defined molecular characteristics. Therefore, this system is considered to be an excellent polymer mixture system for the study of the relationships between static and dynamic phase behaviors of the polymer mixture and the molecular parameters such as molecular weight, polydispersity, microstructure, etc. C1 KYOTO UNIV,FAC ENGN,DEPT POLYMER CHEM,KYOTO 606,JAPAN. NATL INST STAND & TECHNOL,DIV POLYMERS,GAITHERSBURG,MD 20899. NR 33 TC 42 Z9 42 U1 1 U2 10 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 SN 0024-9297 J9 MACROMOLECULES JI Macromolecules PD APR 15 PY 1991 VL 24 IS 8 BP 1813 EP 1819 DI 10.1021/ma00008a019 PG 7 WC Polymer Science SC Polymer Science GA FG750 UT WOS:A1991FG75000019 ER PT J AU BRIBER, RM BAUER, BJ AF BRIBER, RM BAUER, BJ TI SMALL-ANGLE NEUTRON-SCATTERING OF BLENDS OF CROSS-LINKED AND LINEAR POLYSTYRENE SO MACROMOLECULES LA English DT Article ID INTERPENETRATING POLYMER NETWORKS; POLYVINYL METHYL-ETHER); DEUTERATED POLYSTYRENE; PHASE-TRANSITIONS; BEHAVIOR; MIXTURES; RUBBER; GELS AB Small-angle neutron scattering (SANS) has been used to study the scattering function and thermodynamics of blends of linear protonated polystyrene (PSH) and cross-linked deuterated polystyrene (PSD). Two series of samples were synthesized. In both cases the samples were made by dissolving the linear PSH in deuterated (d8) styrene monomer containing a small amount of divinylbenzene, which was then polymerized to form the PSD network around the linear PSH chains. The samples were all made at a concentration of 50/50 by weight PSD/PSH. A special effort was made to keep the samples single phase so that SANS could be used to study the thermodynamics of the single-phase system and compare it with theory. This entailed working at relatively low cross-link densities (< 1 mol % cross-link units). Series 1 is a set of samples with the same cross-link density varying the length of the linear chain. Series 2 is a set of samples containing the same length linear chain varying the cross-link density systematically. By extrapolation of S(q) obtained from SANS using an Ornstein-Zernike plot (S(q)-1 versus q2) to q = 0, the zero-angle scattering, S(0), was obtained. S(0) is inversely proportional to the second derivative of the free energy with respect to composition, partial 2 (DELTA-f/kT)/ partial-phi-2. With the assumption of additivity of the free energies of mixing and elasticity, the portion of the zero-angle scattering due to elasticity is calculated from the scattering. The measured zero-angle scattering can be compared to the scattering calculated from the classical free energy of a swollen network. For the series 1 and 2 samples it was found that the samples could be driven to phase separation by increasing either the length of the linear chain or the network density. In the series 1 samples the zero-angle scattering scaled as S(0)-1 approximately 1/N(b). In the series 2 samples the zero-angle scattering scaled as S(0)-1 approximately 1/N(c). In addition, the scattering was found to increase as N(c) decreased for the series 2 samples, a behavior opposite to that predicted by combining classical rubber elasticity and mixing theories. RP BRIBER, RM (reprint author), NATL INST STAND & TECHNOL,DIV POLYMERS,MAT SCI & ENGN LAB,GAITHERSBURG,MD 20899, USA. RI Briber, Robert/A-3588-2012 OI Briber, Robert/0000-0002-8358-5942 NR 38 TC 37 Z9 37 U1 2 U2 7 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 SN 0024-9297 J9 MACROMOLECULES JI Macromolecules PD APR 15 PY 1991 VL 24 IS 8 BP 1899 EP 1904 DI 10.1021/ma00008a030 PG 6 WC Polymer Science SC Polymer Science GA FG750 UT WOS:A1991FG75000030 ER PT J AU STANSBURY, JW AF STANSBURY, JW TI DIFUNCTIONAL AND MULTIFUNCTIONAL MONOMERS CAPABLE OF CYCLOPOLYMERIZATION SO MACROMOLECULES LA English DT Article ID METHACRYLATE AB The reaction of an acrylate ester with paraformaldehyde in the presence of diazabicyclo[2.2.2]octane has been shown to provide access to novel ether-fused dimethacrylate-like monomers that can undergo cyclopolymerization. This study examined the influence of the pendant ester functionality on the synthesis and polymerization of these monomers. While bulky ester groups were generally found to reduce the rate of reaction in monomer synthesis, the more hindered monomers appear to polymerize through the available intramolecular cyclization pathway with greater efficiency than monomers without significant steric constraints. Polymerizations in solution lead to mainly cyclized, soluble polymers up to relatively high monomer concentrations. Bulk polymerizations provided brittle, cross-linked polymers with high degrees of conversion. This work was extended to include the synthesis of a multifunctional oligomer based on the same 1,6-diene substructure. The polymerization of this oligomer produced a tough, highly cross-linked polymer. RP STANSBURY, JW (reprint author), NATL INST STAND & TECHNOL,DIV POLYMERS,DENT & MED MAT GRP,GAITHERSBURG,MD 20899, USA. NR 17 TC 23 Z9 23 U1 1 U2 3 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 SN 0024-9297 J9 MACROMOLECULES JI Macromolecules PD APR 15 PY 1991 VL 24 IS 8 BP 2029 EP 2035 DI 10.1021/ma00008a049 PG 7 WC Polymer Science SC Polymer Science GA FG750 UT WOS:A1991FG75000049 ER PT J AU ROBINS, LH FARABAUGH, EN FELDMAN, A COOK, LP AF ROBINS, LH FARABAUGH, EN FELDMAN, A COOK, LP TI INVERSE CORRELATION BETWEEN THE INTENSITY OF LUMINESCENCE EXCITED BY ELECTRONS AND BY VISIBLE-LIGHT IN CHEMICAL-VAPOR-DEPOSITED DIAMOND FILMS SO PHYSICAL REVIEW B LA English DT Article ID CATHODOLUMINESCENCE; NITROGEN AB Diamond films grown by filament-assisted or microwave-plasma-assisted chemical-vapor deposition (CVD) were characterized by photoluminescence (PL), cathodoluminescence (CL), and Raman spectroscopies. The laser-excited PL spectra of these films in and near the carbon Raman region (1100-1800 cm-1 from the 514.5-nm laser line, or 2.18-2.28 eV) are broad and featureless; CL spectra measured within a wider spectral range (1.5-3.5 eV) show several distinct components. Because of its correlation with the Raman band of sp2-bonded carbon, the visible-laser-excited PL in the carbon Raman region is attributed to sp2-bonded carbon clusters. The spectrally integrated CL intensity is found to vary from specimen to specimen approximately inversely with the intensity of the laser-excited PL. This inverse correlation is especially strong for one component of the CL, a broad band at 2.85 eV. To explain these results, it is proposed that the luminescence centers in these CVD diamond films can be classified into two types with differing excitation and recombination properties. Rate equations are derived for the luminescence kinetics of such a system of two types of recombination centers. RP ROBINS, LH (reprint author), NATL INST STAND & TECHNOL,DIV CERAM,GAITHERSBURG,MD 20899, USA. NR 12 TC 13 Z9 13 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 APR 15 PY 1991 VL 43 IS 11 BP 9102 EP 9107 DI 10.1103/PhysRevB.43.9102 PG 6 WC Physics, Condensed Matter SC Physics GA FH291 UT WOS:A1991FH29100033 ER PT J AU GRISHCHUK, LP SOLOKHIN, M AF GRISHCHUK, LP SOLOKHIN, M TI SPECTRA OF RELIC GRAVITONS AND THE EARLY HISTORY OF THE HUBBLE PARAMETER SO PHYSICAL REVIEW D LA English DT Article ID INFLATIONARY UNIVERSE AB The spectra of relic gravitational waves produced as a result of cosmological expansion of the generalized inflationary models are derived. It is shown how one can reconstruct the time dependence of the very early Hubble parameter and matter energy density from a measured frequency-dependent spectrum of relic gravitational waves. C1 NATL INST STAND & TECHNOL,GAITHERSBURG,MD 20899. PK SHTERNBERG ASTRON INST,MOSCOW 119899,USSR. RP GRISHCHUK, LP (reprint author), UNIV COLORADO,NATL INST STAND & TECHNOL,JOINT INST LAB ASTROPHYS,BOULDER,CO 80302, USA. NR 19 TC 72 Z9 72 U1 0 U2 0 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 0556-2821 J9 PHYS REV D JI Phys. Rev. D PD APR 15 PY 1991 VL 43 IS 8 BP 2566 EP 2571 DI 10.1103/PhysRevD.43.2566 PG 6 WC Astronomy & Astrophysics; Physics, Particles & Fields SC Astronomy & Astrophysics; Physics GA FH288 UT WOS:A1991FH28800015 ER PT J AU HUDGENS, JW JOHNSON, RD AF HUDGENS, JW JOHNSON, RD TI ELECTRONIC STATES OF SILICON CONTAINING FREE-RADICALS OBSERVED BY RESONANCE ENHANCED MULTIPHOTON IONIZATION SPECTROSCOPY SO ABSTRACTS OF PAPERS OF THE AMERICAN CHEMICAL SOCIETY LA English DT Meeting Abstract C1 NATL INST STAND & TECHNOL,DIV CHEM KINET,GAITHERSBURG,MD 20899. NR 0 TC 0 Z9 0 U1 0 U2 0 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 SN 0065-7727 J9 ABSTR PAP AM CHEM S JI Abstr. Pap. Am. Chem. Soc. PD APR 14 PY 1991 VL 201 BP 2 EP PHYS PN 2 PG 0 WC Chemistry, Multidisciplinary SC Chemistry GA FG894 UT WOS:A1991FG89400507 ER PT J AU ERVIN, KM GRONERT, S BARLOW, SE GILLES, MK HARRISON, AG BIERBAUM, VM DEPUY, CH LINEBERGER, WC ELLISON, GB AF ERVIN, KM GRONERT, S BARLOW, SE GILLES, MK HARRISON, AG BIERBAUM, VM DEPUY, CH LINEBERGER, WC ELLISON, GB TI BOND STRENGTHS OF ETHYLENE AND ACETYLENE SO ABSTRACTS OF PAPERS OF THE AMERICAN CHEMICAL SOCIETY LA English DT Meeting Abstract C1 UNIV COLORADO,DEPT CHEM & BIOCHEM,BOULDER,CO 80309. UNIV COLORADO,NATL INST STAND & TECHNOL,JOINT INST LAB ASTROPHYS,BOULDER,CO 80302. NR 0 TC 0 Z9 0 U1 3 U2 4 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 SN 0065-7727 J9 ABSTR PAP AM CHEM S JI Abstr. Pap. Am. Chem. Soc. PD APR 14 PY 1991 VL 201 BP 6 EP PHYS PN 2 PG 0 WC Chemistry, Multidisciplinary SC Chemistry GA FG894 UT WOS:A1991FG89400511 ER PT J AU MEYERS, PA EADIE, BJ AF MEYERS, PA EADIE, BJ TI ORGANIC-MATTER SOURCES, FLUXES, AND DIAGENESIS IN SINKING PARTICLES IN LAKE-MICHIGAN SO ABSTRACTS OF PAPERS OF THE AMERICAN CHEMICAL SOCIETY LA English DT Meeting Abstract C1 UNIV MICHIGAN,DEPT GEOL SCI,ANN ARBOR,MI 48109. NOAA,GREAT LAKES ENVIRONM RES LAB,ANN ARBOR,MI 48105. NR 0 TC 0 Z9 0 U1 0 U2 0 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 SN 0065-7727 J9 ABSTR PAP AM CHEM S JI Abstr. Pap. Am. Chem. Soc. PD APR 14 PY 1991 VL 201 BP 7 EP GEOC PN 1 PG 0 WC Chemistry, Multidisciplinary SC Chemistry GA FG893 UT WOS:A1991FG89301669 ER PT J AU BENNER, R EADIE, BJ AF BENNER, R EADIE, BJ TI ISOLATION BY ULTRAFILTRATION OF A NEW COMPONENT OF DISSOLVED ORGANIC-MATTER SO ABSTRACTS OF PAPERS OF THE AMERICAN CHEMICAL SOCIETY LA English DT Meeting Abstract C1 UNIV TEXAS,DEPT MARINE SCI,PORT ARANSAS,TX 78373. NOAA,GREAT LAKES ENVIRONM RES LAB,ANN ARBOR,MI 48105. PENN STATE UNIV,FUEL SCI PROGRAM,UNIVERSITY PK,PA 16802. NR 0 TC 0 Z9 0 U1 0 U2 3 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 SN 0065-7727 J9 ABSTR PAP AM CHEM S JI Abstr. Pap. Am. Chem. Soc. PD APR 14 PY 1991 VL 201 BP 11 EP GEOC PN 1 PG 0 WC Chemistry, Multidisciplinary SC Chemistry GA FG893 UT WOS:A1991FG89301673 ER PT J AU WEETALL, HH AF WEETALL, HH TI A HOMOGENEOUS PHOTOELECTROCHEMICAL IMMUNOASSAY SO ABSTRACTS OF PAPERS OF THE AMERICAN CHEMICAL SOCIETY LA English DT Meeting Abstract C1 NATL INST STAND & TECHNOL,CTR CHEM TECHNOL,GAITHERSBURG,MD. NR 0 TC 0 Z9 0 U1 0 U2 0 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 SN 0065-7727 J9 ABSTR PAP AM CHEM S JI Abstr. Pap. Am. Chem. Soc. PD APR 14 PY 1991 VL 201 BP 18 EP AGFD PN 1 PG 0 WC Chemistry, Multidisciplinary SC Chemistry GA FG893 UT WOS:A1991FG89300018 ER PT J AU FITZGERALD, SA GARDNER, WS AF FITZGERALD, SA GARDNER, WS TI EARLY DIAGENESIS OF C-14-LABELED DIATOMS IN NEARSHORE SEDIMENTS FROM LAKE-MICHIGAN - THE ROLE OF BENTHIC AMPHIPODS SO ABSTRACTS OF PAPERS OF THE AMERICAN CHEMICAL SOCIETY LA English DT Meeting Abstract C1 NOAA,GREAT LAKES ENVIRONM RES LAB,ANN ARBOR,MI 48105. NR 0 TC 0 Z9 0 U1 0 U2 0 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 SN 0065-7727 J9 ABSTR PAP AM CHEM S JI Abstr. Pap. Am. Chem. Soc. PD APR 14 PY 1991 VL 201 BP 22 EP GEOC PN 1 PG 0 WC Chemistry, Multidisciplinary SC Chemistry GA FG893 UT WOS:A1991FG89301684 ER PT J AU ELKHADEM, H SHALABY, MA COXON, B FATIADI, AJ AF ELKHADEM, H SHALABY, MA COXON, B FATIADI, AJ TI OXIDATION-REDUCTIONS OF SQUARIC ACID DURING PHENYLHYDRAZONE FORMATION SO ABSTRACTS OF PAPERS OF THE AMERICAN CHEMICAL SOCIETY LA English DT Meeting Abstract C1 AMERICAN UNIV,DEPT CHEM,WASHINGTON,DC 20016. NATL INST STAND & TECHNOL,GAITHERSBURG,MD 20899. NR 0 TC 0 Z9 0 U1 0 U2 0 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 SN 0065-7727 J9 ABSTR PAP AM CHEM S JI Abstr. Pap. Am. Chem. Soc. PD APR 14 PY 1991 VL 201 BP 32 EP CARB PN 1 PG 0 WC Chemistry, Multidisciplinary SC Chemistry GA FG893 UT WOS:A1991FG89300555 ER PT J AU ONEIL, S SENEKOWITSCH, J AF ONEIL, S SENEKOWITSCH, J TI ELECTRONIC-STRUCTURE AND METASTABILITY OF DOUBLY CHARGED DIATOMICS SO ABSTRACTS OF PAPERS OF THE AMERICAN CHEMICAL SOCIETY LA English DT Meeting Abstract C1 JOINT INST LAB ASTROPHYS,BOULDER,CO 80309. UNIV COLORADO,BOULDER,CO 80309. NATL INST STAND & TECHNOL,BOULDER,CO 80309. NR 0 TC 0 Z9 0 U1 1 U2 1 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 SN 0065-7727 J9 ABSTR PAP AM CHEM S JI Abstr. Pap. Am. Chem. Soc. PD APR 14 PY 1991 VL 201 BP 36 EP PHYS PN 2 PG 0 WC Chemistry, Multidisciplinary SC Chemistry GA FG894 UT WOS:A1991FG89400541 ER PT J AU SPRINGERYOUNG, M PIOTROWICZ, SR HARVEY, GR AF SPRINGERYOUNG, M PIOTROWICZ, SR HARVEY, GR TI RESPONSE OF TRACE-METALS AND PRODUCTIVITY TO A SUBTLE PERTURBATION OF OLIGOTROPHIC SEA-WATER SO ABSTRACTS OF PAPERS OF THE AMERICAN CHEMICAL SOCIETY LA English DT Meeting Abstract C1 NOAA,ATLANTIC OCEANOG & METEOROL LAB,OCD,MIAMI,FL 33149. NR 2 TC 0 Z9 0 U1 0 U2 0 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 SN 0065-7727 J9 ABSTR PAP AM CHEM S JI Abstr. Pap. Am. Chem. Soc. PD APR 14 PY 1991 VL 201 BP 45 EP GEOC PN 1 PG 0 WC Chemistry, Multidisciplinary SC Chemistry GA FG893 UT WOS:A1991FG89301707 ER PT J AU HSU, SM HU, ZS WANG, PS AF HSU, SM HU, ZS WANG, PS TI TRIBOCHEMICAL REACTIONS OF STEARIC-ACID ON COPPER SURFACE STUDIED BY FT-IR AND SURFACE ENHANCED RAMAN-SCATTERING SO ABSTRACTS OF PAPERS OF THE AMERICAN CHEMICAL SOCIETY LA English DT Meeting Abstract C1 NATL INST STAND & TECHNOL,GAITHERSBURG,MD 20899. NR 0 TC 0 Z9 0 U1 0 U2 1 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 SN 0065-7727 J9 ABSTR PAP AM CHEM S JI Abstr. Pap. Am. Chem. Soc. PD APR 14 PY 1991 VL 201 BP 49 EP COLL PN 1 PG 0 WC Chemistry, Multidisciplinary SC Chemistry GA FG893 UT WOS:A1991FG89301070 ER PT J AU MCCURLEY, MF SEITZ, WR AF MCCURLEY, MF SEITZ, WR TI FIBER OPTIC CHEMICAL SENSORS BASED ON POLYMER SWELLING SO ABSTRACTS OF PAPERS OF THE AMERICAN CHEMICAL SOCIETY LA English DT Meeting Abstract C1 UNIV NEW HAMPSHIRE,DEPT CHEM,DURHAM,NH 03824. NATL INST STAND & TECHNOL,CTR CHEM TECHNOL,GAITHERSBURG,MD 20899. NR 0 TC 0 Z9 0 U1 0 U2 1 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 SN 0065-7727 J9 ABSTR PAP AM CHEM S JI Abstr. Pap. Am. Chem. Soc. PD APR 14 PY 1991 VL 201 BP 61 EP ANYL PN 1 PG 0 WC Chemistry, Multidisciplinary SC Chemistry GA FG893 UT WOS:A1991FG89300259 ER PT J AU HORVATH, JJ GLAZIER, SA SPANGLER, CJ AF HORVATH, JJ GLAZIER, SA SPANGLER, CJ TI INSITU FLUORESCENCE MEASUREMENTS FOR PROCESS-CONTROL IN BIOREACTORS SO ABSTRACTS OF PAPERS OF THE AMERICAN CHEMICAL SOCIETY LA English DT Meeting Abstract C1 NATL INST STAND & TECHNOL,CTR CHEM TECHNOL,GAITHERSBURG,MD 20899. NR 0 TC 0 Z9 0 U1 0 U2 0 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 SN 0065-7727 J9 ABSTR PAP AM CHEM S JI Abstr. Pap. Am. Chem. Soc. PD APR 14 PY 1991 VL 201 BP 72 EP BIOT PN 1 PG 0 WC Chemistry, Multidisciplinary SC Chemistry GA FG893 UT WOS:A1991FG89300485 ER PT J AU RUDGE, SR AF RUDGE, SR TI APPLICATIONS OF POLYMER THERMODYNAMICS AND NEUTRON-SCATTERING TO THE PARTITIONING OF BIOLOGICAL MOLECULES SO ABSTRACTS OF PAPERS OF THE AMERICAN CHEMICAL SOCIETY LA English DT Meeting Abstract C1 NATL INST STAND & TECHNOL,BOULDER,CO 80303. NR 0 TC 0 Z9 0 U1 0 U2 0 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 SN 0065-7727 J9 ABSTR PAP AM CHEM S JI Abstr. Pap. Am. Chem. Soc. PD APR 14 PY 1991 VL 201 BP 104 EP BIOT PN 1 PG 0 WC Chemistry, Multidisciplinary SC Chemistry GA FG893 UT WOS:A1991FG89300517 ER PT J AU GLAZIER, SA ARNOLD, MA DEMEULENAERE, RL AF GLAZIER, SA ARNOLD, MA DEMEULENAERE, RL TI PHOSPHATE ION-SELECTIVE ELECTRODE DEVELOPMENT SO ABSTRACTS OF PAPERS OF THE AMERICAN CHEMICAL SOCIETY LA English DT Meeting Abstract C1 NATL INST STAND & TECHNOL,CTR CHEM TECHNOL,GAITHERSBURG,MD 20899. UNIV IOWA,DEPT CHEM,IOWA CITY,IA 52242. NR 0 TC 0 Z9 0 U1 0 U2 0 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 SN 0065-7727 J9 ABSTR PAP AM CHEM S JI Abstr. Pap. Am. Chem. Soc. PD APR 14 PY 1991 VL 201 BP 117 EP ANYL PN 1 PG 0 WC Chemistry, Multidisciplinary SC Chemistry GA FG893 UT WOS:A1991FG89300315 ER PT J AU GLAZIER, SA AF GLAZIER, SA TI APPLICATION OF A ARTIFICIAL NEURAL NETWORK TO MULTIION ANALYSIS EMPLOYING ION-SELECTIVE ELECTRODE ARRAYS SO ABSTRACTS OF PAPERS OF THE AMERICAN CHEMICAL SOCIETY LA English DT Meeting Abstract C1 NATL INST STAND & TECHNOL,CTR CHEM TECHNOL,GAITHERSBURG,MD 20899. NR 0 TC 0 Z9 0 U1 0 U2 0 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 SN 0065-7727 J9 ABSTR PAP AM CHEM S JI Abstr. Pap. Am. Chem. Soc. PD APR 14 PY 1991 VL 201 BP 118 EP ANYL PN 1 PG 0 WC Chemistry, Multidisciplinary SC Chemistry GA FG893 UT WOS:A1991FG89300316 ER PT J AU GILLES, MK LINEBERGER, WC AF GILLES, MK LINEBERGER, WC TI PHOTOELECTRON-SPECTROSCOPY OF THE HALOGEN OXIDES SO ABSTRACTS OF PAPERS OF THE AMERICAN CHEMICAL SOCIETY LA English DT Meeting Abstract C1 UNIV COLORADO,NATL INST STAND & TECHNOL,JOINT INST LAB ASTROPHYS,DEPT CHEM & BIOCHEM,BOULDER,CO 80302. NR 0 TC 0 Z9 0 U1 0 U2 0 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 SN 0065-7727 J9 ABSTR PAP AM CHEM S JI Abstr. Pap. Am. Chem. Soc. PD APR 14 PY 1991 VL 201 BP 161 EP PHYS PN 2 PG 0 WC Chemistry, Multidisciplinary SC Chemistry GA FG894 UT WOS:A1991FG89400666 ER PT J AU ROSELLE, SJ SCHERE, KL PIERCE, TE AF ROSELLE, SJ SCHERE, KL PIERCE, TE TI REGIONAL OZONE MODELING IN THE SOUTHEAST UNITED-STATES SO ABSTRACTS OF PAPERS OF THE AMERICAN CHEMICAL SOCIETY LA English DT Meeting Abstract C1 NOAA,DIV ATMOSPHER SCI MODELING,AIR RESOURCES LAB,RES TRIANGLE PK,NC 27711. NR 0 TC 0 Z9 0 U1 0 U2 0 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 SN 0065-7727 J9 ABSTR PAP AM CHEM S JI Abstr. Pap. Am. Chem. Soc. PD APR 14 PY 1991 VL 201 BP 163 EP ENVR PN 1 PG 0 WC Chemistry, Multidisciplinary SC Chemistry GA FG893 UT WOS:A1991FG89301545 ER PT J AU RODGERS, MO ANEJA, VP NEWMAN, L ROBERTS, J PARRISH, D FEHSENFELD, F TRAINER, M AF RODGERS, MO ANEJA, VP NEWMAN, L ROBERTS, J PARRISH, D FEHSENFELD, F TRAINER, M TI 1990 SERON PILOT PROGRAM SO ABSTRACTS OF PAPERS OF THE AMERICAN CHEMICAL SOCIETY LA English DT Meeting Abstract C1 N CAROLINA STATE UNIV,DEPT MARINE EARTH & ATMOSPHER SCI,RALEIGH,NC 27695. BROOKHAVEN NATL LAB,UPTON,NY 11973. NOAA,ENVIRONM RES LAB,AERON LAB,BOULDER,CO 80303. RI Trainer, Michael/H-5168-2013; Fehsenfeld, Frederick/I-4876-2013 NR 0 TC 0 Z9 0 U1 0 U2 0 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 SN 0065-7727 J9 ABSTR PAP AM CHEM S JI Abstr. Pap. Am. Chem. Soc. PD APR 14 PY 1991 VL 201 BP 164 EP ENVR PN 1 PG 0 WC Chemistry, Multidisciplinary SC Chemistry GA FG893 UT WOS:A1991FG89301546 ER PT J AU GALLAGHER, A AF GALLAGHER, A TI PLASMA AND SURFACE-REACTIONS IN A-SI-H DEPOSITION DISCHARGES SO ABSTRACTS OF PAPERS OF THE AMERICAN CHEMICAL SOCIETY LA English DT Meeting Abstract C1 UNIV COLORADO,NATL INST STAND & TECHNOL,JOINT INST LAB ASTROPHYS,BOULDER,CO 80302. NR 0 TC 0 Z9 0 U1 0 U2 0 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 SN 0065-7727 J9 ABSTR PAP AM CHEM S JI Abstr. Pap. Am. Chem. Soc. PD APR 14 PY 1991 VL 201 BP 242 EP PHYS PN 2 PG 0 WC Chemistry, Multidisciplinary SC Chemistry GA FG894 UT WOS:A1991FG89400747 ER PT J AU BUNTIN, SA RICHTER, LJ KING, DS CAVANAGH, RR AF BUNTIN, SA RICHTER, LJ KING, DS CAVANAGH, RR TI STATE-RESOLVED STUDIES OF LASER-INDUCED DESORPTION FROM SI(111) SO ABSTRACTS OF PAPERS OF THE AMERICAN CHEMICAL SOCIETY LA English DT Meeting Abstract C1 NATL INST STAND & TECHNOL,CTR ATOM MOLEC & OPT PHYS,GAITHERSBURG,MD 20899. RI Richter, Lee/N-7730-2016 OI Richter, Lee/0000-0002-9433-3724 NR 0 TC 0 Z9 0 U1 0 U2 0 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 SN 0065-7727 J9 ABSTR PAP AM CHEM S JI Abstr. Pap. Am. Chem. Soc. PD APR 14 PY 1991 VL 201 BP 254 EP COLL PN 1 PG 0 WC Chemistry, Multidisciplinary SC Chemistry GA FG893 UT WOS:A1991FG89301272 ER PT J AU RUSH, JJ AF RUSH, JJ TI NEUTRON INELASTIC STUDIES OF HYDROGEN IN AND ON METALS AND CATALYSTS SO ABSTRACTS OF PAPERS OF THE AMERICAN CHEMICAL SOCIETY LA English DT Meeting Abstract C1 NATL INST STAND & TECHNOL,MAT SCI & ENGN LAB,GAITHERSBURG,MD 20899. NR 0 TC 0 Z9 0 U1 0 U2 0 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 SN 0065-7727 J9 ABSTR PAP AM CHEM S JI Abstr. Pap. Am. Chem. Soc. PD APR 14 PY 1991 VL 201 BP 269 EP PHYS PN 2 PG 0 WC Chemistry, Multidisciplinary SC Chemistry GA FG894 UT WOS:A1991FG89400774 ER PT J AU HOWARD, CJ AF HOWARD, CJ TI USE OF STABLE ISOTOPES TO DETERMINE RATES AND MECHANISMS OF GAS-PHASE REACTIONS SO ABSTRACTS OF PAPERS OF THE AMERICAN CHEMICAL SOCIETY LA English DT Meeting Abstract C1 NOAA,AERON LAB,BOULDER,CO 80303. NR 0 TC 0 Z9 0 U1 0 U2 0 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 SN 0065-7727 J9 ABSTR PAP AM CHEM S JI Abstr. Pap. Am. Chem. Soc. PD APR 14 PY 1991 VL 201 BP 272 EP PHYS PN 2 PG 0 WC Chemistry, Multidisciplinary SC Chemistry GA FG894 UT WOS:A1991FG89400777 ER PT J AU NESBITT, DJ AF NESBITT, DJ TI IVR IN SLIT JET COOLED MOLECULES - A SMOKING GUN IN THE FREQUENCY-DOMAIN SO ABSTRACTS OF PAPERS OF THE AMERICAN CHEMICAL SOCIETY LA English DT Meeting Abstract C1 UNIV COLORADO,NATL INST STAND & TECHNOL,JOINT INST LAB ASTROPHYS,BOULDER,CO 80302. NR 0 TC 0 Z9 0 U1 0 U2 0 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 SN 0065-7727 J9 ABSTR PAP AM CHEM S JI Abstr. Pap. Am. Chem. Soc. PD APR 14 PY 1991 VL 201 BP 278 EP PHYS PN 2 PG 0 WC Chemistry, Multidisciplinary SC Chemistry GA FG894 UT WOS:A1991FG89400783 ER PT J AU LEONE, SR AF LEONE, SR TI LASER STUDIES OF ION MOBILITY AND REACTION DYNAMICS SO ABSTRACTS OF PAPERS OF THE AMERICAN CHEMICAL SOCIETY LA English DT Meeting Abstract C1 UNIV COLORADO,NATL INST STAND & TECHNOL,JOINT INST LAB ASTROPHYS,BOULDER,CO 80302. UNIV COLORADO,NATL INST STAND & TECHNOL,DEPT CHEM & BIOCHEM,BOULDER,CO 80309. NR 0 TC 0 Z9 0 U1 0 U2 0 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 SN 0065-7727 J9 ABSTR PAP AM CHEM S JI Abstr. Pap. Am. Chem. Soc. PD APR 14 PY 1991 VL 201 BP 282 EP PHYS PN 2 PG 0 WC Chemistry, Multidisciplinary SC Chemistry GA FG894 UT WOS:A1991FG89400787 ER PT J AU FERGUSON, EE AF FERGUSON, EE TI FLOW TUBE STUDIES OF DIATOMIC ION VIBRATIONAL QUENCHING SO ABSTRACTS OF PAPERS OF THE AMERICAN CHEMICAL SOCIETY LA English DT Meeting Abstract C1 NOAA,CLIMATE MONITORING & DIAGNOST LAB,BOULDER,CO 80303. NR 0 TC 0 Z9 0 U1 0 U2 0 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 SN 0065-7727 J9 ABSTR PAP AM CHEM S JI Abstr. Pap. Am. Chem. Soc. PD APR 14 PY 1991 VL 201 BP 284 EP PHYS PN 2 PG 0 WC Chemistry, Multidisciplinary SC Chemistry GA FG894 UT WOS:A1991FG89400789 ER PT J AU SENEKOWITSCH, J ONEIL, SV WERNER, HJ KNOWLES, PJ AF SENEKOWITSCH, J ONEIL, SV WERNER, HJ KNOWLES, PJ TI ABINITIO CHARACTERIZATION OF NF2+ SO JOURNAL OF PHYSICS B-ATOMIC MOLECULAR AND OPTICAL PHYSICS LA English DT Article ID CONFIGURATION-INTERACTION METHOD; STATE; EXPANSIONS; CI AB Eight electronic states of the NF2+ ion have been calculated by a second-order CI (SOCI) method employing complete active space (CASSCF) reference wavefunctions and large triple zeta plus polarization basis sets. In analogy to O(2)2+, there are two low-lying quasibound electronic states. The calculated position of the 3II state at 5.7 eV above the X 1-sigma+ ground state agrees with the recent experimental observation of Rogers et al. The spectroscopic data of the ground state agree reasonably well with the calculations of Wong et al but are believed to be more accurate. C1 UNIV SUSSEX,SCH CHEM & MOLEC SCI,BRIGHTON BN1 9QJ,E SUSSEX,ENGLAND. UNIV BIELEFELD,FACHBEREICH CHEM,W-4800 BIELEFELD,GERMANY. RP SENEKOWITSCH, J (reprint author), NATL INST STAND & TECHNOL,JOINT INST LAB ASTROPHYS,BOULDER,CO 80309, USA. RI Knowles, Peter/G-2985-2010; Werner, Hans-Joachim/G-9509-2011 OI Knowles, Peter/0000-0003-4657-6331; Werner, Hans-Joachim/0000-0002-0435-539X NR 25 TC 7 Z9 8 U1 0 U2 1 PU IOP PUBLISHING LTD PI BRISTOL PA TECHNO HOUSE, REDCLIFFE WAY, BRISTOL, ENGLAND BS1 6NX SN 0953-4075 J9 J PHYS B-AT MOL OPT JI J. Phys. B-At. Mol. Opt. Phys. PD APR 14 PY 1991 VL 24 IS 7 BP 1529 EP 1538 DI 10.1088/0953-4075/24/7/008 PG 10 WC Optics; Physics, Atomic, Molecular & Chemical SC Optics; Physics GA FJ566 UT WOS:A1991FJ56600008 ER PT J AU CHANG, SS AF CHANG, SS TI TEMPERATURE-GRADIENT IN DIFFERENTIAL SCANNING CALORIMETRY SO THERMOCHIMICA ACTA LA English DT Article ID KINETIC-PARAMETERS; DSC AB A temperature gradient is required for any type of heat flow process. In a dynamic calorimeter, temperature gradients exist in the entire calorimetric system during the measurement of temperature differences or heat flow. Most organic materials are of relatively low thermal conductivity in comparison to metallic and inorganic materials. Therefore large temperature gradients are expected to exist in organic materials during the measurement. The magnitude of the temperature gradient can be estiamted through a simple modeling procedure. The results of experimentally determined temperature gradients during the cure of an epoxy resin in a differential scanning calorimeter are presented to confirm the expected magnitude of temperature non-uniformity. RP CHANG, SS (reprint author), NATL INST STAND & TECHNOL,MAT SCI & ENGN LAB,DIV POLYMERS,GAITHERSBURG,MD 20899, USA. 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 0040-6031 J9 THERMOCHIM ACTA JI Thermochim. Acta PD APR 12 PY 1991 VL 178 BP 195 EP 201 DI 10.1016/0040-6031(91)80310-F PG 7 WC Thermodynamics; Chemistry, Analytical; Chemistry, Physical SC Thermodynamics; Chemistry GA FH842 UT WOS:A1991FH84200019 ER PT J AU JUDGE, PG STENCEL, RE AF JUDGE, PG STENCEL, RE TI EVOLUTION OF THE CHROMOSPHERES AND WINDS OF LOW-MASS AND INTERMEDIATE-MASS GIANT STARS SO ASTROPHYSICAL JOURNAL LA English DT Article DE STARS, CHROMOSPHERES; STARS, LATE-TYPE; STARS, WINDS ID OUTER ATMOSPHERIC STRUCTURE; STATIC MODEL PHOTOSPHERES; CIRCUMSTELLAR DUST SHELLS; CARBON-MONOXIDE EMISSION; LONG-PERIOD VARIABLES; REVISED AFGL CATALOGS; CO J=1-0 OBSERVATIONS; RED GIANTS; LOSS RATES; CHEMICAL-COMPOSITION AB We analyze empirically the global thermodynamical properties of the outer atmospheres of giant stars. The paper differs from earlier work in two ways: (1) we address mass-loss energetics and the heating of the outer layers together, using the theoretical framework of Holzer and MacGregor; (2) our stellar sample represents most phases of giant-branch evolution without restrictions imposed by using individual observational techniques. The sample contains stars of representative variability classes and infrared properties. Ultraviolet radiation losses from giants between spectral types K1 III and M5 III (mostly first giant branch [FGB] stars) follow trends found for earlier spectral types by previous authors. Later spectral types (mostly second ascent or asymptotic giant branch [AGB] stars) show a larger scatter, probably related to the increased variability of these objects. Wind energy fluxes are remarkably similar, for both FGB and AGB stars, and they may be independent of dust-shell optical depths. The wind energy requirements of infrared carbon stars as a group are slightly higher than those of the other stars, and they also have larger wind velocities. We conclude that mass-loss rates are not strongly dependent on the actual physical processes driving the winds, and suggest that nonlinear processes act to regulate wind energy fluxes. As a corollary, correlations of mass, energy, and momentum fluxes with any other observed property cannot be used to examine the actual processes leading to mass loss for most red giants. This brings into question the validity of some earlier studies. We suggest that dust formation is not a primary instigator of mass loss from most cool giants. We discuss possible mechanisms responsible for chromospheric heating and mass loss, pointing to the need for theories to account for the relative invariance of the energy fluxes. We argue that sufficient energy is available in long-period photospheric variations in all cool giants to account for the wind losses, and suggest directions for future studies. C1 UNIV COLORADO, CTR ASTROPHYS & SPACE ASTRON, BOULDER, CO 80309 USA. RP UNIV COLORADO, NATL INST STAND TECHNOL, JOINT INST LAB ASTROPHYS, POB 0440, BOULDER, CO 80309 USA. NR 149 TC 104 Z9 104 U1 0 U2 0 PU IOP PUBLISHING LTD PI BRISTOL PA TEMPLE CIRCUS, TEMPLE WAY, BRISTOL BS1 6BE, ENGLAND SN 0004-637X EI 1538-4357 J9 ASTROPHYS J JI Astrophys. J. PD APR 10 PY 1991 VL 371 IS 1 BP 357 EP 379 DI 10.1086/169897 PN 1 PG 23 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA FE865 UT WOS:A1991FE86500034 ER PT J AU LINGLE, CS SCHILLING, DH FASTOOK, JL PATERSON, WSB BROWN, TJ AF LINGLE, CS SCHILLING, DH FASTOOK, JL PATERSON, WSB BROWN, TJ TI A FLOW BAND MODEL OF THE ROSS ICE SHELF, ANTARCTICA - RESPONSE TO CO2-INDUCED CLIMATIC WARMING SO JOURNAL OF GEOPHYSICAL RESEARCH-SOLID EARTH AND PLANETS LA English DT Article ID STREAM-B; WEST ANTARCTICA; NUMERICAL-MODEL; MASS BALANCE; BENEATH; SHEET; DEFORMATION; VELOCITY AB A time-dependent model is applied to the Ross Ice Shelf flow band discharging ice stream B, West Antarctica. The model includes the effects of temperature, depth-dependent density, and backpressure from the coasts of the Ross embayment and Crary Ice Rise. Data from the Ross Ice Shelf Geophysical and Glaciological Survey and the Siple Coast Project are used as input data. Accuracy and stability are verified by reproducing the flow band for 10,000 model years with equilibrium distributions of accumulation, surface temperature, and basal balance. Sensitivity is tested by forcing the model with increasing accumulation rates, surface temperatures, and basal melt rates, respectively, while other factors are held constant. The response of the ice shelf to three climatic scenarios that may result from increasing carbon dioxide and trace greenhouse gases is simulated. The results range from slight thickening with moderately increased backpressure in the grounding zone to rapid thinning accompanied by rapidly decreasing backpressure during 175- to 600-year simulations, depending primarily upon whether increasing surface temperatures and accumulation rates are accompanied by increased rates of basal melting. The central ice shelf, about 400 km upglacier from the calving front, thins by 22% in 600 years when basal melting is increased linearly to a maximum of 0.5 m/yr after 150 years, then held steady. The ice shelf thins by 40% in 175 years at the same location when basal melting is increased linearly to 2.0 m/yr after 150 years, then held steady. The present calculated equilibrium rate of basal melting, averaged over the bottom surface of the flow band, is 0.17 m/yr. C1 UNIV MAINE,DEPT COMP SCI,ORONO,ME 04469. UNIV ALASKA,INST GEOPHYS,FAIRBANKS,AK 99775. PATERSON GEOPHYS INC,HERIOT BAY V0P 1H0,BC,CANADA. UNIV WISCONSIN,RICE LAKE,WI 54868. RP LINGLE, CS (reprint author), UNIV COLORADO,NOAA,COOPERAT INST RES ENVIRONM SCI,BOULDER,CO 80309, USA. NR 68 TC 13 Z9 13 U1 2 U2 3 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 SN 0148-0227 J9 J GEOPHYS RES-SOLID PD APR 10 PY 1991 VL 96 IS B4 BP 6849 EP 6871 DI 10.1029/91JB00197 PG 23 WC Geosciences, Multidisciplinary SC Geology GA FG773 UT WOS:A1991FG77300063 ER PT J AU SWARTZENDRUBER, LJ KAISER, DL GAYLE, FW BENNETT, LH ROYTBURD, A AF SWARTZENDRUBER, LJ KAISER, DL GAYLE, FW BENNETT, LH ROYTBURD, A TI LOW-FIELD FLUX PINNING IN TWINNED AND DETWINNED SINGLE-CRYSTALS OF YBA2CU3O7-X SO APPLIED PHYSICS LETTERS LA English DT Article ID GROWTH AB Flux trapping in single crystals of YBa2Cu3O7-x before and after twin removal has been measured for vortices parallel and perpendicular to the c axis. The results show clearly that, for low applied magnetic fields, twins contribute significantly to flux pinning over the temperature range 60 to 85 K when the vortices are parallel to the twin boundaries (i.e., parallel to the c axis). RP SWARTZENDRUBER, LJ (reprint author), NATL INST STAND & TECHNOL,MAT SCI & ENGN LAB,GAITHERSBURG,MD 20899, USA. NR 18 TC 28 Z9 28 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 APR 8 PY 1991 VL 58 IS 14 BP 1566 EP 1568 DI 10.1063/1.105180 PG 3 WC Physics, Applied SC Physics GA FF231 UT WOS:A1991FF23100038 ER PT J AU SIMIU, E COOK, GR ALIBE, B AF SIMIU, E COOK, GR ALIBE, B TI ALGEBRAIC-APPROXIMATION OF ATTRACTORS FOR GALLOPING OSCILLATORS SO JOURNAL OF SOUND AND VIBRATION LA English DT Letter RP SIMIU, E (reprint author), US DEPT COMMERCE,NATL INST STANDARDS & TECHNOL,CTR BLDG TECHNOL,GAITHERSBURG,MD 20899, USA. NR 3 TC 2 Z9 2 U1 0 U2 0 PU ACADEMIC PRESS LTD PI LONDON PA 24-28 OVAL RD, LONDON, ENGLAND NW1 7DX SN 0022-460X J9 J SOUND VIB JI J. Sound Vibr. PD APR 8 PY 1991 VL 146 IS 1 BP 170 EP 175 DI 10.1016/0022-460X(91)90530-W PG 6 WC Acoustics; Engineering, Mechanical; Mechanics SC Acoustics; Engineering; Mechanics GA FH965 UT WOS:A1991FH96500012 ER PT J AU SCHIFFMAN, A NELSON, DD ROBINSON, MS NESBITT, DJ AF SCHIFFMAN, A NELSON, DD ROBINSON, MS NESBITT, DJ TI HIGH-RESOLUTION INFRARED FLASH KINETIC SPECTROSCOPY OF OH RADICALS SO JOURNAL OF PHYSICAL CHEMISTRY LA English DT Article ID HYDROGEN-ATOM ABSTRACTION; ABSOLUTE RATE CONSTANTS; EXCIMER LASER PHOTOLYSIS; GAS-PHASE REACTION; HYDROXYL RADICALS; ENERGY-TRANSFER; NORMAL-BUTANE; HOT ATOMS; ETHANE; ALKANES AB A high-resolution infrared flash kinetic spectrometer is used for time- and frequency-resolved studies of the OH radical. OH is produced by 193-nm excimer laser photolysis of HNO3/buffer gas mixtures in a 100-cm flow tube and is probed via weak fractional absorption of light from a widely tunable (2.35 -3.59-mu-m) single-mode (DELTA-nu less-than-or-equal-to 2 MHz) color center laser. The IR absorption technique allows fast (less-than-or-equal-to 10(-6) s), sensitive (< 10(9) radicals/cm3 per quantum state) detection of OH and is designed to permit determination of absolute OH number densities. The spectrometer is used to measure rate constants for the reactions of OH with ethane (k1), propane (k2), n-butane (k3), and isobutane (k4). The reliability of these measurements is tested on a variety of rotational, spin-orbit, and lambda-doublet states, with several buffer gases, and over more than an order of magnitude of alkane concentrations. The resulting rate constants are, in units of 10(-12) cm3 molecule-1 s-1, k1 = 0.243 +/- 0.012, k2 = 1.02 +/- 0.05, k3 = 2.35 +/- 0.08, and k4 = 2.11 +/- 0.09. The rate constants for the ethane, n-butane, and isobutane reactions agree with some previous determinations but are found to be between 10% and 25% lower than values currently used in atmospheric modeling; it is recommended that these values be revised to reflect the lower rates from this study. Current models of atmospheric air flow based on these rate constants, as well as those of previously accepted values, are found to be inconsistent with daily changes in observed atmospheric alkane concentrations. C1 UNIV COLORADO,DEPT CHEM & BIOCHEM,BOULDER,CO 80309. RP SCHIFFMAN, A (reprint author), UNIV COLORADO,NATL INST STAND & TECHNOL,JOINT INST LAB ASTROPHYS,BOULDER,CO 80309, USA. NR 54 TC 25 Z9 25 U1 2 U2 8 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 SN 0022-3654 J9 J PHYS CHEM-US JI J. Phys. Chem. PD APR 4 PY 1991 VL 95 IS 7 BP 2629 EP 2636 DI 10.1021/j100160a004 PG 8 WC Chemistry, Physical SC Chemistry GA FE953 UT WOS:A1991FE95300004 ER PT J AU MCILROY, A LASCOLA, R LOVEJOY, CM NESBITT, DJ AF MCILROY, A LASCOLA, R LOVEJOY, CM NESBITT, DJ TI STRUCTURAL DEPENDENCE OF HF VIBRATIONAL RED SHIFTS IN ARNHF, N = 1-4, VIA HIGH-RESOLUTION SLIT JET INFRARED-SPECTROSCOPY SO JOURNAL OF PHYSICAL CHEMISTRY LA English DT Article ID POTENTIAL-ENERGY SURFACE; IR LASER SPECTROSCOPY; ROTATIONAL SPECTRA; SMALL CLUSTERS; VANDERWAALS MOLECULES; FREQUENCY-SHIFTS; SUPERSONIC JETS; COMPLEXES; ARGON; DYNAMICS AB The rotationally resolved upsilon = 1 <-- 0 HF stretching spectra of Ar(n)HF, n = 1-4, have been observed by using a slit jet, difference frequency infrared laser spectrometer. The red shift of the HF vibrational frequency is seen to be sensitively dependent on the placement of the Ar with respect to the projection of the HF dipole moment; the largest incremental red shift is observed for the ArHF linear geometry. The n = 1-3 red shifts account for almost half (9.65-19.26 cm-1) of the shift observed for HF in an Ar matrix (42.4 cm-1), suggesting that only the nearest neighbors contribute significantly to the perturbation of the HF vibrational frequency. The geometry of the experimentally observed isomer of Ar4HF places the fourth Ar in what would be the second coordination layer from the HF where it has little effect (< 2%) on the observed red shift, supporting the proposed dominance of the nearest neighbors in determining the HF vibrational frequency. In all spectra, no evidence for vibrational predissociation is observed, indicating an extremely long excited state lifetime (greater-than-or-similar-to 16 ns). C1 UNIV COLORADO,NATL INST STAND & TECHNOL,JOINT INST LAB ASTROPHYS,BOULDER,CO 80309. UNIV COLORADO,DEPT CHEM & BIOCHEM,BOULDER,CO 80309. NR 34 TC 96 Z9 96 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 APR 4 PY 1991 VL 95 IS 7 BP 2636 EP 2644 DI 10.1021/j100160a005 PG 9 WC Chemistry, Physical SC Chemistry GA FE953 UT WOS:A1991FE95300005 ER PT J AU JACOX, ME THOMPSON, WE AF JACOX, ME THOMPSON, WE TI VIBRATIONAL-SPECTRA OF MOLECULAR-IONS ISOLATED IN SOLID NEON .6. CO4- SO JOURNAL OF PHYSICAL CHEMISTRY LA English DT Article ID ATMOSPHERIC POSITIVE-IONS; ELECTRON-SPIN-RESONANCE; NEGATIVE-IONS; CLUSTER IONS; PHOTO-DISSOCIATION; ARGON MATRIX; CO2-O2-H2O MIXTURES; CATION RADICALS; RATE CONSTANTS; GAS-PHASE AB When a Ne:CO2:O2 = 200:1:1 mixture is codeposited at approximately 5 K with a beam of neon atoms that have been excited in a microwave discharge, several prominent infrared absorptions appear in the resulting deposit. In addition to the absorptions of unreacted CO2, absorptions previously assigned to O4+ and O4- are present, and new absorptions appear at 697, 1256, 1865, and 1895 cm-1. Detailed isotopic substitution experiments demonstrate that these new absorptions are contributed by a product of formula CO4 in which the CO2 moiety is joined to O2 in such a way that the two O atoms of each of these groups are nonequivalent. Arguments are presented indicating that this product is the CO4- anion. The infrared frequencies of the isotopically substituted species have been used for a least-squares force constant adjustment calculation, assuming a planar O2C..O2-(C(s)) structure in which most of the negative charge remains on the O2 moiety. The photodestruction threshold of CO4- lies near 260 nm. Evidence has been obtained for the formation of CO3- or of CO3 in an excited state with 3-fold symmetry, for which randomization of the oxygen isotopic substitution occurs. C1 NATL SCI FDN,WASHINGTON,DC 20550. RP JACOX, ME (reprint author), NATL INST STAND & TECHN,DIV MOLEC PHYS,GAITHERSBURG,MD 20899, USA. NR 50 TC 31 Z9 31 U1 0 U2 9 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 APR 4 PY 1991 VL 95 IS 7 BP 2781 EP 2787 DI 10.1021/j100160a028 PG 7 WC Chemistry, Physical SC Chemistry GA FE953 UT WOS:A1991FE95300028 ER PT J AU CLINE, JI LEONE, SR AF CLINE, JI LEONE, SR TI TEMPERATURE-DEPENDENCE OF THE QUENCHING OF I-STAR(2P3/2) BY I2 FROM 300-K TO 800-K SO JOURNAL OF PHYSICAL CHEMISTRY LA English DT Article ID EXCITED IODINE ATOMS; LASER; KINETICS; PHOTODISSOCIATION; SPECTROSCOPY; DEACTIVATION; RADICALS; BR2 AB The quenching rate of I*(2P1/2) by I2 is measured over the temperature range 297-800 K by using a time-resolved diode laser absorption/gain method. The room-temperature bimolecular quenching rate constant is determined to be k(q) = (2.89 +/- 0.06) X 10(-11) cm3/(molecule.s), in good agreement with several previous determinations. The rate is found to be independent of temperature over the temperature range 300-800 K within experimental uncertainty; at 800 K the quenching rate is k(q) = (3.02 +/- 0.30) x 10(-11) cm3/(molecule.s) The temperature dependence is consistent with a quenching mechanism involving the formation of an I3 intermediate complex. The quantum yield for I* formation from the 480-nm photolysis of I2 is measured to be 0.304 +/- 0.001 at 297 K and increases slightly with temperature. This quantum yield is significantly larger than that previously determined. C1 NATL INST STAND & TECHNOL,JOINT INST LAB ASTROPHYS,BOULDER,CO 80309. UNIV COLORADO,DEPT CHEM & BIOCHEM,BOULDER,CO 80309. NR 26 TC 26 Z9 26 U1 0 U2 2 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 SN 0022-3654 J9 J PHYS CHEM-US JI J. Phys. Chem. PD APR 4 PY 1991 VL 95 IS 7 BP 2917 EP 2920 DI 10.1021/j100160a049 PG 4 WC Chemistry, Physical SC Chemistry GA FE953 UT WOS:A1991FE95300049 ER PT J AU VAGHJIANI, GL RAVISHANKARA, AR AF VAGHJIANI, GL RAVISHANKARA, AR TI NEW MEASUREMENT OF THE RATE COEFFICIENT FOR THE REACTION OF OH WITH METHANE SO NATURE LA English DT Article ID FLASH-PHOTOLYSIS; CLIMATE CHANGE; KINETICS; CH4; CHEMISTRY AB METHANE is an important greenhouse gas, whose concentration in the troposphere is steadily increasing. To estimate the flux of methane into the atmosphere and its atmospheric lifetime, its rate of removal needs to be accurately determined. The main loss process for atmospheric methane is the reaction with the hydroxyl radical OH. We have measured the rate coefficient for this reaction in carefully controlled experiments and found it to be smaller than currently accepted values. Our results indicate a longer CH4 lifetime (by approximately 25%) and a correspondingly smaller flux (by approximately 100 Tg CH4 yr-1) than previously calculated. C1 NOAA,AERON LAB,325 BROADWAY,BOULDER,CO 80303. UNIV COLORADO,NOAA,COOPERAT INST RES ENVIRONM SCI,BOULDER,CO 80309. UNIV COLORADO,DEPT CHEM & BIOCHEM,BOULDER,CO 80309. RI Ravishankara, Akkihebbal/A-2914-2011 NR 18 TC 168 Z9 172 U1 6 U2 28 PU MACMILLAN MAGAZINES LTD PI LONDON PA 4 LITTLE ESSEX STREET, LONDON, ENGLAND WC2R 3LF SN 0028-0836 J9 NATURE JI Nature PD APR 4 PY 1991 VL 350 IS 6317 BP 406 EP 409 DI 10.1038/350406a0 PG 4 WC Multidisciplinary Sciences SC Science & Technology - Other Topics GA FF042 UT WOS:A1991FF04200043 ER PT J AU CHADWICK, WW EMBLEY, RW FOX, CG AF CHADWICK, WW EMBLEY, RW FOX, CG TI EVIDENCE FOR VOLCANIC-ERUPTION ON THE SOUTHERN JUAN-DE-FUCA RIDGE BETWEEN 1981 AND 1987 SO NATURE LA English DT Article AB THE formation of new ocean crust at mid-ocean ridges is known to be a discontinuous process in both space and time, but little is known about the frequency and duration of eruptions along an active ridge segment. Here we present evidence, from Sea Beam surveys and underwater photography, for the eruption of lavas along a segment of the Juan de Fuca ridge between 1981 and 1987. Although previous studies have inferred volcanic activity on ridges in areas where recent seismicity or young lava flows have been observed 1-4, none has yet had direct evidence to date such a recent submarine eruption. The temporal coincidence between this eruptive episode and the megaplumes (huge, sudden emissions of hot mineral-laden water) observed over this part of the ridge 5,6 in 1986 and 1987 supports previous suggestions 5-10 that megaplumes are caused by sea-floor spreading events. C1 NOAA,HATFIELD MARINE SCI CTR,PACIFIC MARINE ENVIRONM LAB,NEWPORT,OR 97365. RP CHADWICK, WW (reprint author), OREGON STATE UNIV,CIMRS,HATFIELD MARINE SCI CTR,NEWPORT,OR 97365, USA. RI Wright, Dawn/A-4518-2011 OI Wright, Dawn/0000-0002-2997-7611 NR 14 TC 80 Z9 81 U1 1 U2 3 PU MACMILLAN MAGAZINES LTD PI LONDON PA 4 LITTLE ESSEX STREET, LONDON, ENGLAND WC2R 3LF SN 0028-0836 J9 NATURE JI Nature PD APR 4 PY 1991 VL 350 IS 6317 BP 416 EP 418 DI 10.1038/350416a0 PG 3 WC Multidisciplinary Sciences SC Science & Technology - Other Topics GA FF042 UT WOS:A1991FF04200047 ER PT J AU BALDOCCHI, DD LUXMOORE, RJ HATFIELD, JL AF BALDOCCHI, DD LUXMOORE, RJ HATFIELD, JL TI DISCERNING THE FOREST FROM THE TREES - AN ESSAY ON SCALING CANOPY STOMATAL CONDUCTANCE SO AGRICULTURAL AND FOREST METEOROLOGY LA English DT Review ID EDDY-CORRELATION MEASUREMENTS; ENERGY-BALANCE EQUATION; SURFACE-TEMPERATURE; DECIDUOUS FOREST; SENSIBLE HEAT; WATER-VAPOR; CARBON-DIOXIDE; WHEAT CANOPY; LATENT-HEAT; SOIL-WATER AB Stomata are major conduits for the diffusion of many trace gases between leaves and the atmosphere. The role of the stomata in controlling gas exchange between the terrestrial biosphere and the atmosphere at the landscape, meso- and global scales has only recently been appreciated. Further advances in modeling trace gas exchange will depend on our ability to provide realistic information on stomatal mechanics at the sub-grid scale of landscape and meso scale models; in other words, information is needed at the canopy scale. This paper describes two approaches for estimating canopy stomatal conductance. These are the 'bottom-up' and 'top-down' scaling methods. The bottom-up method entails computing canopy stomatal conductance by integrating the response of individual leaves to controling biotic and abiotic factors, which are determined by the micrometeorology of the canopy. The top-down approach entails inverting a descriptive stand-level, trace gas exchange model to estimate canopy stomatal conductance. The model is driven with abiotic variables measured at a reference point above the canopy. The strengths and weaknesses of these two approaches are discussed, and recommendations for future research are presented. C1 OAK RIDGE NATL LAB,DIV ENVIRONM SCI,OAK RIDGE,TN 37831. USDA ARS,NATL SOIL TILTH LAB,AMES,IA 50011. RP BALDOCCHI, DD (reprint author), NOAA,ARL,DIV ATMOSPHER TURBULENCE & DIFFUS,POB 2456,OAK RIDGE,TN 37831, USA. RI Baldocchi, Dennis/A-1625-2009 OI Baldocchi, Dennis/0000-0003-3496-4919 NR 126 TC 115 Z9 116 U1 0 U2 19 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0168-1923 J9 AGR FOREST METEOROL JI Agric. For. Meteorol. PD APR PY 1991 VL 54 IS 2-4 BP 197 EP 226 DI 10.1016/0168-1923(91)90006-C PG 30 WC Agronomy; Forestry; Meteorology & Atmospheric Sciences SC Agriculture; Forestry; Meteorology & Atmospheric Sciences GA FP090 UT WOS:A1991FP09000006 ER PT J AU DUTTA, BK SIKDAR, SK AF DUTTA, BK SIKDAR, SK TI SEPARATION OF AZEOTROPIC ORGANIC LIQUID-MIXTURES BY PERVAPORATION SO AICHE JOURNAL LA English DT Article ID ION-EXCHANGE MEMBRANES; ALCOHOL WATER MIXTURES; DOWNSTREAM PRESSURE; POLYMER MEMBRANES; BINARY-MIXTURES; ETHANOL; PERMSELECTIVITY AB We have shown that ionomeric membranes of perfluorosulfonic acid (PFSA) polymer allow selective pervaporation of polar organic compounds from their azeotropic mixtures with less polar compounds. A composite membrane of a thin PFSA polymer film, cast on a porous Teflon support, provided desirable permeant fluxes with good selectivity. Model binary azeotropes, composed of alcohols and hydrocarbons, were separated with total pervaporation fluxes of up to 9.5 kg/h.m2 using a stirred membrane permeation cell, the product side of which was exposed to vacuum. Fluxes increased with increasing alcohol content of the feed and with temperature. But the selectivity of the more permeating component remained reasonably constant around the azeotropic point and also over the range of temperature used in the study (25-55-degrees-C). Total pervaporation fluxes depended little on downstream pressure up to 6.66 kPa (50 torr). These separation data were explained by a mathematical model based on a solution-diffusion mechanism. RP DUTTA, BK (reprint author), NATL INST STAND & TECHNOL,CTR CHEM TECHNOL,BOULDER,CO 80303, USA. NR 29 TC 57 Z9 59 U1 1 U2 4 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 APR PY 1991 VL 37 IS 4 BP 581 EP 588 DI 10.1002/aic.690370411 PG 8 WC Engineering, Chemical SC Engineering GA FJ416 UT WOS:A1991FJ41600010 ER PT J AU OLTHOFF, JK VANBRUNT, RJ HERRON, JT SAUERS, I AF OLTHOFF, JK VANBRUNT, RJ HERRON, JT SAUERS, I TI DETECTION OF TRACE DISULFUR DECAFLUORIDE IN SULFUR-HEXAFLUORIDE BY GAS-CHROMATOGRAPHY MASS-SPECTROMETRY SO ANALYTICAL CHEMISTRY LA English DT Article ID CYTO-TOXIC ACTIVITY; S2F10; SF6; PHASE; SOF2 AB A new method is described for detection of S2F10 in SF6 in the parts-per-billion (ppb) level. The method utilizes a gas chromatograph/mass spectrometer (GC/MS) equipped with a heated jet separator. S2F10 is converted to SOF2 on the hot surfaces of the low-pressure portions of the jet separator at temperatures above 150-degrees-C by a surface-catalyzed reaction involving H2O. As a consequence of this conversion, peaks corresponding to S2F10 appear on single-ion chromatograms at ion masses characteristic of SOF2 (m/z = 48, 67, and 86) where there is little or no interference from SF6 features. By this method, a direct analysis of SF6 for S2F10 content can be performed with greater sensitivity than conventional gas chromatographic methods and with a higher degree of reliability and in a time much shorter than required for chromatographic methods that use enrichment procedures. Problems associated with the preparation and stability of reliable S2F10 reference samples are discussed. C1 OAK RIDGE NATL LAB,DIV HLTH & SAFETY RES,OAK RIDGE,TN 37831. RP OLTHOFF, JK (reprint author), NATL INST STAND & TECHNOL,GAITHERSBURG,MD 20899, USA. NR 30 TC 16 Z9 17 U1 1 U2 1 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 SN 0003-2700 J9 ANAL CHEM JI Anal. Chem. PD APR 1 PY 1991 VL 63 IS 7 BP 726 EP 732 DI 10.1021/ac00007a015 PG 7 WC Chemistry, Analytical SC Chemistry GA FD917 UT WOS:A1991FD91700019 ER PT J AU BARROW, CH WATERMANN, J EVANS, DS WILHELM, K AF BARROW, CH WATERMANN, J EVANS, DS WILHELM, K TI OBSERVATIONS OF ANTARCTIC AURORAL ELECTRON-PRECIPITATION WITH HIGH-STABILITY IN TIME AND LONGITUDE SO ANNALES GEOPHYSICAE-ATMOSPHERES HYDROSPHERES AND SPACE SCIENCES LA English DT Article ID SATELLITE AB Electron flux measurements were made in the energy range 0.1 to 12.5 keV, by the electron spectrometer 1ES019 on board Spacelab 1, during the period 29 November to 7 December 1983. The spacecraft was in a 57-degrees inclination circular orbit at an altitude of about 250 km with an orbital period of 90 min. Although the experiment was originally designed for artificial electron beam response observations, several periods of natural energetic electron precipitation were also recorded and these have been surveyed and catalogued. The data are interesting because of the high resolution of the electron spectrometer, the relatively low spacecraft altitude for the observations and the path of Spacelab 1 almost along the auroral oval. On 30 November 1983 Spacelab 1 observed electron precipitation during four successive southern hemisphere passes, one of which is of particular interest as the NOAA-7 satellite, which measured electron flux in the energy range 0.3 to 20 keV at an altitude of about 850 km, was then quite close in space and time. As correlative riometer and magnetometer observations suggest that auroral conditions remained stable during the 25-min period between the two sets of observations, the observations are used to infer the gross spatial structure of the auroral precipitation over the midnight sector. Comparison of the electron energy spectra observed by Spacelab 1 and NOAA-7 at different magnetic local times and at different altitudes suggests a high degree of longitudinal homogeneity in the precipitation. C1 NOAA,SPACE ENVIRONM RES LABS,BOULDER,CO 80303. NATL RES COUNCIL CANADA,HERZBERG INST ASTROPHYS,OTTAWA K1A 0R6,ONTARIO,CANADA. RP BARROW, CH (reprint author), MAX PLANCK INST AERON,W-3411 KATLENBURG DUHM,GERMANY. NR 11 TC 1 Z9 1 U1 0 U2 0 PU SPRINGER VERLAG PI NEW YORK PA 175 FIFTH AVE, NEW YORK, NY 10010 SN 0992-7689 J9 ANN GEOPHYS JI Ann. Geophys.-Atmos. Hydrospheres Space Sci. PD APR PY 1991 VL 9 IS 4 BP 259 EP 266 PG 8 WC Astronomy & Astrophysics; Geosciences, Multidisciplinary; Meteorology & Atmospheric Sciences SC Astronomy & Astrophysics; Geology; Meteorology & Atmospheric Sciences GA FL814 UT WOS:A1991FL81400006 ER PT J AU WILLIAMS, PA ROSE, AH DAY, GW MILNER, TE DEETER, MN AF WILLIAMS, PA ROSE, AH DAY, GW MILNER, TE DEETER, MN TI TEMPERATURE-DEPENDENCE OF THE VERDET CONSTANT IN SEVERAL DIAMAGNETIC GLASSES SO APPLIED OPTICS LA English DT Note DE VERDET CONSTANT; FARADAY EFFECT; TEMPERATURE DEPENDENCE; CURRENT SENSOR; MAGNETIC FIELD SENSOR RP WILLIAMS, PA (reprint author), NATL INST STAND & TECHNOL,BOULDER,CO 80303, USA. RI Deeter, Merritt/O-6078-2016 OI Deeter, Merritt/0000-0002-3555-0518 NR 9 TC 70 Z9 82 U1 4 U2 17 PU OPTICAL SOC AMER PI WASHINGTON PA 2010 MASSACHUSETTS AVE NW, WASHINGTON, DC 20036 SN 0003-6935 J9 APPL OPTICS JI Appl. Optics PD APR 1 PY 1991 VL 30 IS 10 BP 1176 EP 1178 PG 3 WC Optics SC Optics GA FG122 UT WOS:A1991FG12200006 PM 20582125 ER PT J AU COSTANTINO, PD FRIEDMAN, CD JONES, K CHOW, LC PELZER, HJ SISSON, GA AF COSTANTINO, PD FRIEDMAN, CD JONES, K CHOW, LC PELZER, HJ SISSON, GA TI HYDROXYAPATITE CEMENT .1. BASIC CHEMISTRY AND HISTOLOGIC PROPERTIES SO ARCHIVES OF OTOLARYNGOLOGY-HEAD & NECK SURGERY LA English DT Article ID CORALLINE HYDROXYAPATITE; BONE-GRAFTS; SURGERY; RECONSTRUCTION; IMPLANTS; TISSUE AB Hydroxyapatite cement is a unique calcium phosphate preparation that can be shaped intraoperatively and sets in vivo to an implant composed of microporous hydroxyapatite. The histologic response to this cement was evaluated by implanting disks made of this material within the heads of nine cats. Three sets of 12 hydroxyapatite cement disks were produced containing 0%, 10%, and 20% macropores by volume, respectively. The disks were implanted subcutaneously, intramuscularly, above the periosteum of the skull, and directly onto the surface of the calvarium. Each macropore percentage was represented in each tissue plane, and animals were lkilled up to 9 months postoperatively. There were no toxic reactions, implants extruded, or wound infections. Histologic examination of the implant-soft-tissue interfaces revealed a transient inflammatory response without foreign body reaction. The disks were resorbed over time in direct proportion to their macropore content (surface areas) in all groups except for those disks placed directly onto the surface of the calvarium below the periosteum. In this group, numerous foci of bone formed at the skull-implant interface, with variable replacement of the deep surface of these implants by bone. Implant replacement by bone is postulated to occur through a combination of implant resorption coupled with osteoconduction. Based on these properties, hydroxyapatite cement may prove useful when applied to the reconstruction of non-stress-bearing skeletal tissue. C1 YALE UNIV,SCH MED,OTOLARYNGOL HEAD & NECK SURG SECT,POB 3333,333 CEDAR ST,NEW HAVEN,CT 06510. NORTHWESTERN UNIV,SCH MED,DEPT OTOLARYNGOL HEAD & NECK SURG,CHICAGO,IL 60611. NATL INST STAND & TECHNOL,AMER DENT ASSOC HLTH FDN,PAFFENBARGER RES INST,GAITHERSBURG,MD. FU NIDCR NIH HHS [DE-05030] NR 32 TC 177 Z9 184 U1 0 U2 7 PU AMER MEDICAL ASSOC PI CHICAGO PA 515 N STATE ST, CHICAGO, IL 60610 SN 0886-4470 J9 ARCH OTOLARYNGOL JI Arch. Otolaryngol. Head Neck Surg. PD APR PY 1991 VL 117 IS 4 BP 379 EP 384 PG 6 WC Otorhinolaryngology; Surgery SC Otorhinolaryngology; Surgery GA FF344 UT WOS:A1991FF34400004 PM 1848766 ER PT J AU FRIEDMAN, CD COSTANTINO, PD JONES, K CHOW, LC PELZER, HJ SISSON, GA AF FRIEDMAN, CD COSTANTINO, PD JONES, K CHOW, LC PELZER, HJ SISSON, GA TI HYDROXYAPATITE CEMENT .2. OBLITERATION AND RECONSTRUCTION OF THE CAT FRONTAL-SINUS SO ARCHIVES OF OTOLARYNGOLOGY-HEAD & NECK SURGERY LA English DT Article ID DEFECTS; IMPLANT; BONE AB Frontal sinus obliteration and reconstruction can be performed with autogenous grafts or synthetic implants, each of which has significant limitations. Hydroxyapatite cement, which can be shaped intraoperatively and sets to a microporous hydroxyapatite implant, was applied to this problem. Nine cats had the anterior table of their frontal sinus unilaterally removed and the sinus cavity stripped of its mucosa. Hydroxyapatite cement was used to obliterate the cavity and reconstruct the overlying anterior table defect. The unoperated side served as the control, and the animals were sacrificed up to 18 months postoperatively. There were no adverse reactions, infections, mucoceles, or implant extrusions. The normal anatomic contour of the forehead region overlying the hydroxyapatite cement implants was maintained in all animals. Histologic examination of undecalcified whole sinus sections revealed progressive replacement of the implants with woven bone without a loss of volume. Replacement of the hydroxyapatite cement by woven bone is postulated to occur through a combination of implant resorption coupled with osteoconduction. The use of hydroxyapatite cement proved successful for the reconstruction and obliteration of cat frontal sinuses, and may be appropriate for the same application in humans. C1 NATL INST STAND & TECHNOL,AMER DENT ASSOC HLTH FDN,PAFFENBARGER RES INST,GAITHERSBURG,MD. NORTHWESTERN UNIV,SCH MED,DEPT OTOLARYNGOL HEAD & NECK SURG,CHICAGO,IL 60611. RP FRIEDMAN, CD (reprint author), YALE UNIV,SCH MED,OTOLARYNGOL HEAD & NECK SURG SECT,POB 3333,333 CEDAR ST,NEW HAVEN,CT 06510, USA. FU NIDCR NIH HHS [DE-05030] NR 30 TC 214 Z9 222 U1 0 U2 2 PU AMER MEDICAL ASSOC PI CHICAGO PA 515 N STATE ST, CHICAGO, IL 60610 SN 0886-4470 J9 ARCH OTOLARYNGOL JI Arch. Otolaryngol. Head Neck Surg. PD APR PY 1991 VL 117 IS 4 BP 385 EP 389 PG 5 WC Otorhinolaryngology; Surgery SC Otorhinolaryngology; Surgery GA FF344 UT WOS:A1991FF34400005 PM 1848767 ER PT J AU BUSHBY, ST NEWMAN, HM AF BUSHBY, ST NEWMAN, HM TI THE BACNET COMMUNICATION PROTOCOL FOR BUILDING AUTOMATION SYSTEMS SO ASHRAE JOURNAL-AMERICAN SOCIETY OF HEATING REFRIGERATING AND AIR-CONDITIONING ENGINEERS LA English DT Article RP BUSHBY, ST (reprint author), NATL INST STAND & TECHNOL,CTR BLDG TECHNOL,DIV BLDG ENVIRONM,MECH SYST & CONTROL GRP,GAITHERSBURG,MD, USA. NR 0 TC 3 Z9 3 U1 0 U2 1 PU AMER SOC HEAT REFRIG AIR- CONDITIONING ENG INC PI ATLANTA PA 1791 TULLIE CIRCLE NE, ATLANTA, GA 30329 SN 0001-2491 J9 ASHRAE J JI ASHRAE J.-Am. Soc. Heat Refrig. Air-Cond. Eng. PD APR PY 1991 VL 33 IS 4 BP 14 EP & PG 0 WC Thermodynamics; Construction & Building Technology; Engineering, Mechanical SC Thermodynamics; Construction & Building Technology; Engineering GA FF090 UT WOS:A1991FF09000003 ER PT J AU TREADO, SJ AF TREADO, SJ TI THE NIST LIGHTING AND HVAC INTERACTION TEST FACILITY SO ASHRAE JOURNAL-AMERICAN SOCIETY OF HEATING REFRIGERATING AND AIR-CONDITIONING ENGINEERS LA English DT Article RP TREADO, SJ (reprint author), NATL INST STAND & TECHNOL,CTR BLDG TECHNOL,GAITHERSBURG,MD, USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU AMER SOC HEAT REFRIG AIR- CONDITIONING ENG INC PI ATLANTA PA 1791 TULLIE CIRCLE NE, ATLANTA, GA 30329 SN 0001-2491 J9 ASHRAE J JI ASHRAE J.-Am. Soc. Heat Refrig. Air-Cond. Eng. PD APR PY 1991 VL 33 IS 4 BP 47 EP & PG 0 WC Thermodynamics; Construction & Building Technology; Engineering, Mechanical SC Thermodynamics; Construction & Building Technology; Engineering GA FF090 UT WOS:A1991FF09000008 ER PT J AU PARR, RM DEMAEYER, EM IYENGAR, VG BYRNE, AR KIRKBRIGHT, GF SCHOCH, G NIINISTO, L PINEDA, O VIS, HL HOFVANDER, Y OMOLOLU, A AF PARR, RM DEMAEYER, EM IYENGAR, VG BYRNE, AR KIRKBRIGHT, GF SCHOCH, G NIINISTO, L PINEDA, O VIS, HL HOFVANDER, Y OMOLOLU, A TI MINOR AND TRACE-ELEMENTS IN HUMAN-MILK FROM GUATEMALA, HUNGARY, NIGERIA, PHILIPPINES, SWEDEN, AND ZAIRE - RESULTS FROM A WHO/IAEA JOINT PROJECT SO BIOLOGICAL TRACE ELEMENT RESEARCH LA English DT Article DE HUMAN MILK; ELEMENTAL COMPOSITION; TRACE ELEMENTS; GEOGRAPHIC COMPARISON; GEOCHEMICAL INFLUENCE; LACTATION; INFANT NUTRITION; PEDIATRIC MINERAL NUTRITION; DEVELOPING COUNTRIES; URBAN; RURAL ID NEUTRON-ACTIVATION ANALYSIS; BIOLOGICAL-MATERIALS; HUMAN LACTATION; MINERAL-CONTENT; CHROMIUM; SAMPLES; WOMEN; ABSORPTION; MOLYBDENUM; INFANTS AB Concentrations of As, Ca, Cd, Cl, Co, Cr, Cu, F, Fe, Hg, I, K, Mg, Mn, Mo, Na, Ni, P, Pb, Sb, Se, Sn, V, and Zn were determined in human whole milk samples from Guatemala, Hungary, Nigeria, Philippines, Sweden, and Zaire; in most of these countries, three groups of subjects representing different socioeconomic conditions were studied. Analytical quality control was a primary consideration throughout. The analytical techniques used were atomic absorption spectrophotometry, atomic emission spectrometry with an inductively coupled plasma, colorimetry, electrochemistry, using an ion-selective electrode and neutron activation analysis. The differences between median concentrations of Ca, Cl, Mg, K, Na, and P (minor elements) were lower than 20% among the six countries. Among trace elements, concentrations observed in Filipino milk for As, Cd, Co, Cr, Cu, F, Fe, Mn, Mo, Ni, Pb, Sb, Se, and V were higher than for milk samples from other countries. The remaining five countries showed a mixed picture of high and low values. In the case of at least some elements, such as, F, I, Hg, Mn, Pb, and Se, the environment appears to play a major role in determining their concentrations in human milk. The nutritional status of the mother, as reflected by her socioeconomic status, does not appear to influence significantly the breast milk concentrations of minor and trace elements. Significant differences exist between the actual daily intakes observed in this study and current dietary recommendations made by, for example, WHO and the US National Academy of Sciences. These differences are particularly large (an order of magnitude or more!) for Cr, F, Fe, Mn, and Mo; for other elements, such as, Ca, Cu, Mg, P, and Zn, they amount to at least a factor 2. In the opinion of the present authors, these findings point to the need for a possible reassessment of the dietary requirements of young infants, with respect to minor and trace elements, particularly for the elements Ca, Cr, Cu, F, Fe, Mg, Mn, Mo, P, and Zn. C1 WHO, CH-1211 GENEVA 27, SWITZERLAND. FORSCHUNGSZENTRUM JULICH, NUCL RES CTR, INST MED, W-5170 JULICH, GERMANY. NATL INST STANDARDS & TECHNOL, CTR ANALYT CHEM, GAITHERSBURG, MD 20899 USA. JOZEF STEFAN INST, DEPT NUCL CHEM, YU-61111 LJUBLJANA, YUGOSLAVIA. UNIV MANCHESTER, DEPT INSTRUMENTAT & ANALYT SCI, MANCHESTER M60 1QD, LANCS, ENGLAND. FORSCH INST KINDERERNAEHR, W-4600 DORTMUND, GERMANY. HELSINKI UNIV TECHNOL, INORGAN & ANALYT CHEM LAB, SF-2150 ESPOO, FINLAND. INST NUTR CENT AMER & PANAMA, GUATEMALA CITY, GUATEMALA. FREE UNIV BRUSSELS, DEPT PEDIAT, B-1050 BRUSSELS, BELGIUM. UNIV HOSP UPPSALA, DEPT PEDIAT, S-75185 UPPSALA, SWEDEN. UNIV IBADAN, COLL MED, IBADAN, NIGERIA. RP PARR, RM (reprint author), INT ATOM ENERGY AGCY, A-1400 VIENNA, AUSTRIA. NR 62 TC 78 Z9 80 U1 1 U2 5 PU HUMANA PRESS INC PI TOTOWA PA 999 RIVERVIEW DRIVE SUITE 208, TOTOWA, NJ 07512 USA SN 0163-4984 J9 BIOL TRACE ELEM RES JI Biol. Trace Elem. Res. PD APR PY 1991 VL 29 IS 1 BP 51 EP 75 PG 25 WC Biochemistry & Molecular Biology; Endocrinology & Metabolism SC Biochemistry & Molecular Biology; Endocrinology & Metabolism GA FH243 UT WOS:A1991FH24300006 PM 1711362 ER PT J AU TEWARI, YB GOLDBERG, RN AF TEWARI, YB GOLDBERG, RN TI THERMODYNAMICS OF HYDROLYSIS OF DISACCHARIDES - LACTULOSE, ALPHA-D-MELIBIOSE, PALATINOSE, D-TREHALOSE, D-TURANOSE AND 3-O-BETA-D-GALACTOPYRANOSYL-D-ARABINOSE SO BIOPHYSICAL CHEMISTRY LA English DT Article DE ENTHALPY; EQUILIBRIUM CONSTANT; LACTULOSE; ALPHA-D-MELIBIOSE; PALATINOSE; D-TREHALOSE; D-TURANOSE; 3-O-BETA-D-GALACTOPYRANOSYL-D-ARABINOSE ID ISOMERIZATION-REACTIONS; CRYSTAL-STRUCTURE; SUGAR PHOSPHATES; AQUEOUS GLUCOSE; CONVERSION; FRUCTOSE AB High-pressure liquid chromatography and microcalorimetry have been used to study the thermodynamics of the hydrolysis reactions of a series of dissaccharides. The enzymes used to bring about the hydrolyses were: beta-galactosidase for lactulose and 3-o-beta-D-galactopyranosyl-D-arabinose; beta-glucosidase for alpha-D-melibiose; beta-amylase for D-trehalose; isomaltase for palatinose; and alpha-glucosidase for D-turanose. The buffer used was sodium acetate (0.02-0.10 M and pH 4.44-5.65). For the following processes at 298.15 K: lactulose(aq) + H2O(liq) = D-galactose(aq) + D-fructose(aq), K-degrees = 128 +/- 10 and DELTA-H-degrees = 2.21 +/- 0.10 kJ mol-1; alpha-D-melibiose(aq) + H2O(liq) = D-galactose(aq) + D-glucose(aq), K-degrees = 123 +/- 42 and DELTA-H-degrees = -0.88 +/- 0.50 kJ mol-1; palatinose(aq) + H2O(liq) = D-glucose(aq) + D-fructose(aq), DELTA-H-degrees = -4.44 +/- 1.1 kJ mol-1; D-trehalose(aq) + H2O(liq) = 2 D-glucose(aq), K-degrees = 119 +/- 10 and DELTA-H-degrees = 4.73 +/- 0.41 kJ mol-1; D-turanose(aq) + H2O(liq) = D-glucose(aq) + D-fructose(aq), DELTA-H-degrees = -2.68 +/- 0.75 kJ mol-1; and 3-o-beta-D-galactopyranosyl-D-arabinose(aq) + H2O(liq) = D-galactose(aq) + D-arabinose(aq), K-degrees = 107 +/- 10 and DELTA-H-degrees = 2.97 +/- 0.10 kJ mol-1. These six processes correspond, respectively, to the hydrolysis of the following linkages: galactose-fructose (1 --> 4), galactose-glucose (1 --> 6), glucose-fructose (1 --> 6), glucose-glucose (1 --> 1'), glucose-fructose (1 --> 3), and galactose-arabinose (1 --> 3). Using available data in the literature, the heat capacity changes for these processes are found to be in the range -36 to -69 mol-1 K-1. The available thermodynamic data on the hydrolysis of disaccharides is summarized. It is found that the entropy changes for the hydrolysis of disaccharides are in the range 31-56 J mol-1 K-1 and are well represented by an average value of 40 +/- 7 J mol-1 K-1. The abnormally high enthalpy of hydrolysis of aqueous sucrose (-14.96 kJ mol-1) can be explained by consideration of the enthalpy of conversion of fructopyranose to fructofuranose. C1 NATL INST STAND & TECHNOL,DIV CHEM THERMODYNAM,GAITHERSBURG,MD 20899. NR 28 TC 37 Z9 38 U1 0 U2 15 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0301-4622 J9 BIOPHYS CHEM JI Biophys. Chem. PD APR PY 1991 VL 40 IS 1 BP 59 EP 67 DI 10.1016/0301-4622(91)85029-P PG 9 WC Biochemistry & Molecular Biology; Biophysics; Chemistry, Physical SC Biochemistry & Molecular Biology; Biophysics; Chemistry GA FJ851 UT WOS:A1991FJ85100005 PM 1873472 ER PT J AU GOLDBERG, RN BELL, D TEWARI, YB MCLAUGHLIN, MA AF GOLDBERG, RN BELL, D TEWARI, YB MCLAUGHLIN, MA TI THERMODYNAMICS OF HYDROLYSIS OF OLIGOSACCHARIDES SO BIOPHYSICAL CHEMISTRY LA English DT Article DE AMYLOSE; ENTHALPY; ISOMALTOTRIOSE; MALTOSE; MALTOHEPTAOSE; MALTOHEXAOSE; MALTOPENTAOSE; MALTOTETRAOSE; MALTOTRIOSE; PANOSE; RAFFINOSE; STACHYOSE AB Microcalorimetry has been used to determine enthalpy changes for the hydrolysis of a series of oligosaccharides. High-pressure liquid chromatography was used to determine the extents of reaction and to check for any possible side reactions. The enzyme glucan 1,4-alpha-glucosidase was used to bring about the following hydrolysis reactions: (A) maltose(aq) + H2O(liq) = 2D-glucose(aq); (B) maltotriose(aq) + 2H2O(liq) = 3D-glucose(aq); (C) maltotetraose(aq) + 3H2O(liq) - 4D-glucose(aq); (D) maltopentaose(aq) + 4H2O(liq) = 5D-glucose(aq); (E) maltohexaose(aq) + 5H2O(liq) = 6D-glucose(aq); (F) maltoheptaose(aq) + 6H2O(liq) = 7D-glucose(aq); (G) amylose(aq) + nH2O(liq) = (n + 1) D-glucose(aq); and (H) panose(aq) + 2H2O(liq) = 3D-glucose(aq); (J) isomaltotriose(aq) + 2H2O(liq) = 3D-glucose(aq). The enzyme beta-fructofuranosidase was used for the reactions: (K) raffinose(aq) + H2O(liq) = alpha-D-melibiose(aq) + D-fructose(aq); and (L) stachyose(aq) + H2O(liq) = o-alpha-D-galactopyranosyl-(1 --> 6)-alpha-o-D-galactopyranosyl-(1 --> 6)-alpha-D-glucopyranose + D-fructose(aq). The results of the calorimetric measurements (298.15 K, 0.1 M sodium acetate buffer, pH 4.44-6.00) are: DELTA-H(A)degrees = -4.55 +/- 0.10, DELTA-H(B)degrees = -9.03 +/- 0.10, DELTA-H(C)degrees = -13.79 +/- 0.15, DELTA-H(D)degrees = -18.12 +/- 0.10, DELTA-H(E)degrees = -22.40 +/- 0.15, DELTA-H(F)degrees = -26.81 +/- 0.20, DELTA-H(H)degrees = 1.46 +/- 0.40, DELTA-H(J)degrees = 11.4 +/- 2.0, DELTA-H(K)degrees = -15.25 +/- 0.20, and DELTA-H(L)degrees = -14.93 +/- 0.20 kJ mol-1. The enthalpies of hydrolysis of two different samples of amylose were 1062 +/- 20 and 2719 +/- 100 kJ mol-1, respectively. These processes correspond to the hydrolysis of the following linkages: glucose-glucose (alpha,1 --> 4) glucose-glucose (alpha,1 --> 6), and glucose-fructose (1 --> 6). The respective enthalpy changes accompanying the hydrolysis of these linkages are -4.53, 5.8 and -15.0 kJ mol-1. Both these results and available thermodynamic data in the literature demonstrate that additivity works well in predicting the thermodynamics of hydrolysis reactions involving oligosaccharides. C1 US FDA,WASHINGTON,DC 20204. RP GOLDBERG, RN (reprint author), NATL INST STAND & TECHNOL,DIV CHEM THERMODYNAM,GAITHERSBURG,MD 20899, USA. NR 15 TC 19 Z9 19 U1 1 U2 10 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0301-4622 J9 BIOPHYS CHEM JI Biophys. Chem. PD APR PY 1991 VL 40 IS 1 BP 69 EP 76 DI 10.1016/0301-4622(91)85030-T PG 8 WC Biochemistry & Molecular Biology; Biophysics; Chemistry, Physical SC Biochemistry & Molecular Biology; Biophysics; Chemistry GA FJ851 UT WOS:A1991FJ85100006 PM 1873473 ER PT J AU TESTA, JW OEHLERT, G AINLEY, DG BENGTSON, JL SINIFF, DB LAWS, RM ROUNSEVELL, D AF TESTA, JW OEHLERT, G AINLEY, DG BENGTSON, JL SINIFF, DB LAWS, RM ROUNSEVELL, D TI TEMPORAL VARIABILITY IN ANTARCTIC MARINE ECOSYSTEMS - PERIODIC FLUCTUATIONS IN THE PHOCID SEALS SO CANADIAN JOURNAL OF FISHERIES AND AQUATIC SCIENCES LA English DT Article ID EL-NINO; SOUTHERN OSCILLATION; LEPTONYCHOTES-WEDDELLI; SURFACE TEMPERATURE; MCMURDO SOUND; PACIFIC-OCEAN; PATTERNS; LEOPARD AB Three species of seals around Antarctica have shown quasi-cyclic patterns in some aspect of their biology: the age structure of crabeater seals (Lobodon carcinophagus) around the Antarctic Peninsula has shown strong cohorts separated by 4- to 5-yr intervals; juvenile leopard seals (Hydruga leptonyx) have appeared in unusually large numbers at Macquarie Island, also at 4- to 5-yr intervals; and Weddell seals (Leptonychotes weddellii) in McMurdo Sound have undergone fluctuations in reproductive rate every 4-6 yr. Complex demodulation was used to compare patterns among these three data sets and with the Southern Oscillation Index (SOI). All of the seal data sets showed evidence of cyclical behavior when demodulated at a period of 5 yr. The Weddell seals were generally in phase with the SOI since the Weddell series began in 1970. The leopard seals and SOI were in phase in the 1960's, but thereafter the SOI series led the leopard seal series by about one quarter of a cycle. The crabeater series was more complicated, but similarities with the other data sets also were seen. If these tentative observations are confirmed, they point to large-scale oceanographic variation, possibly related to the El Nino - Southern Oscillation (ENSO), as an important mechanism in Antarctic marine ecosystems. C1 UNIV MINNESOTA,APPL STAT,ST PAUL,MN 55108. POINT REYES BIRD OBSERV,STINSON BEACH,CA 94970. NATL MARINE MAMMAL LAB,SEATTLE,WA 98115. UNIV MINNESOTA,DEPT ECOL & BEHAV BIOL,MINNEAPOLIS,MN 55455. ST EDMUNDS COLL,CAMBRIDGE CB3 0BN,ENGLAND. LANDS PARKS & WILDLIFE,HOBART,TAS 7001,AUSTRALIA. RP TESTA, JW (reprint author), UNIV ALASKA,INST MARINE SCI,FAIRBANKS,AK 99775, USA. NR 39 TC 67 Z9 68 U1 3 U2 10 PU NATL RESEARCH COUNCIL CANADA PI OTTAWA PA RESEARCH JOURNALS, MONTREAL RD, OTTAWA ON K1A 0R6, CANADA SN 0706-652X J9 CAN J FISH AQUAT SCI JI Can. J. Fish. Aquat. Sci. PD APR PY 1991 VL 48 IS 4 BP 631 EP 639 PG 9 WC Fisheries; Marine & Freshwater Biology SC Fisheries; Marine & Freshwater Biology GA FF520 UT WOS:A1991FF52000015 ER PT J AU DEHAAG, PU MEERTS, WL HOUGEN, JT AF DEHAAG, PU MEERTS, WL HOUGEN, JT TI A STUDY OF THE S1 6(1) (1A2'') VIBRONICALLY EXCITED-STATE OF SYM-TRIAZINE BY HIGH-RESOLUTION UV LASER SPECTROSCOPY SO CHEMICAL PHYSICS LA English DT Article ID FLUORESCENCE EXCITATION SPECTRUM; PYRAZINE; DECONVOLUTION; AZABENZENES; ASSIGNMENTS; LIFETIME; MOLECULE; SYSTEM; VAPOR AB We have measured the laser induced fluorescence spectrum of the S1-6(1)(1A2")<--S0(1A1') vibronic transition in sym-triazine at 317 nm. An instrumental line width of 12 MHz was achieved by the use of a molecular beam in combination with a cw single frequency laser. In this way rotationally resolved spectra were obtained. Furthermore, we have measured the lifetime of some selected ensembles of rovibronic states with a narrow band pulsed laser system. It is shown that the excited S1-6(1)(A2") vibronic state is strongly perturbed by a singlet-triplet interaction. This interaction results in additional lines in the high-resolution spectrum. A nearly complete rotational assignment is given for the transitions to the upper state with rotational quantum number J up to J = 4 and the rotational constants are derived. No evidence is found for a Jahn-Teller distortion of the rotational states in the S1-6(1)(A2") vibronic state. With some assumptions the singlet-triplet coupling matrix elements were deduced as well as the energy separation between the singlet state and the perturbing triplet state. A singlet-triplet gap of 4800 +/- 600 cm-1 is estimated. C1 NATL INST STAND & TECHNOL,DIV MOLEC SPECTR,GAITHERSBURG,MD 20899. RP DEHAAG, PU (reprint author), CATHOLIC UNIV NIJMEGEN,FYS LAB,6525 ED NIJMEGEN,NETHERLANDS. RI Meerts, W. Leo/B-6172-2008 OI Meerts, W. Leo/0000-0001-6457-3797 NR 29 TC 2 Z9 2 U1 0 U2 0 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0301-0104 J9 CHEM PHYS JI Chem. Phys. PD APR 1 PY 1991 VL 151 IS 3 BP 371 EP 383 DI 10.1016/0301-0104(91)80022-A PG 13 WC Chemistry, Physical; Physics, Atomic, Molecular & Chemical SC Chemistry; Physics GA FG857 UT WOS:A1991FG85700008 ER PT J AU SHAO, ZX YI, C BERGQUIST, JC AF SHAO, ZX YI, C BERGQUIST, JC TI AN EFFICIENT CW ND-FAP LASER SO CHINESE PHYSICS LA English DT Article AB An efficient CW Nd:FAP laser pumped by a dye (LD 700) laser, operated at the strong line at 1.0629-mu-m and the weak line at 1.1259-mu-m is presented. The comparison in threshold and efficiency of Nd:FAP with Nd:YAG laser at different spectrum lines is also demonstrated. C1 JILIN INST LASERS,CHANGCHUN,PEOPLES R CHINA. NATL INST STAND & TECHNOL,DIV TIME & FREQUENCY,BOULDER,CO 80303. RP SHAO, ZX (reprint author), CHINESE ACAD SCI,CHANGCHUN INST OPT & FINE MECH,CHANGCHUN,PEOPLES R CHINA. NR 3 TC 4 Z9 4 U1 0 U2 1 PU AMER INST PHYSICS PI WOODBURY PA CIRCULATION FULFILLMENT DIV, 500 SUNNYSIDE BLVD, WOODBURY, NY 11797-2999 SN 0273-429X J9 CHINESE PHYS PD APR-JUN PY 1991 VL 11 IS 2 BP 391 EP 393 PG 3 WC Physics, Multidisciplinary SC Physics GA FP580 UT WOS:A1991FP58000022 ER PT J AU CHASTEEN, TG FALL, R BIRKS, JW MARTIN, HR GLINSKI, RJ AF CHASTEEN, TG FALL, R BIRKS, JW MARTIN, HR GLINSKI, RJ TI FLUORINE-INDUCED CHEMILUMINESCENCE DETECTION OF PHOSPHINE, ALKYL PHOSPHINES AND MONOPHOSPHINATE ESTERS SO CHROMATOGRAPHIA LA English DT Article DE GAS CHROMATOGRAPHY; CHEMILUMINESCENCE DETECTION; PHOSPHINE DERIVATIVES; HEADSPACE ANALYSIS; FLUORINE ID CHEMI-LUMINESCENCE; ORGANOSULFUR COMPOUNDS; LIQUID-CHROMATOGRAPHY; PHOSPHORUS CYCLE; SULFUR-COMPOUNDS AB Phosphine, alkylated phosphines and monophosphinate esters are detected with high sensitivity in capillary gas chromatography (GC) by their chemiluminescent reactions with molecular fluorine. Detection limits are estimated to be 1.3 pg, 0.5 pg, 8 pg, and 17 pg for phosphine, trimethyl phosphine, trimethyl phosphinate ester, and triethyl phosphine, respectively. As found earlier with alkylated sulfur, selenium and tellurium compounds, the detector exhibits a linear response. For triethyl phosphine, a linear range of greater than three orders of magnitude was demonstrated. Emission spectra were obtained for the trimethyl phosphine and triethyl phosphine systems. Chemiluminescence emitters include electronically excited HCF, vibrationally excited HF, and an unknown species in the trimethyl phosphine system. Banded emission from vibrationally excited HF and a broad continuum were observed for both trimethyl phosphine and triethyl phosphine; however, HCF emission was observed only for TMP. Under the conditions employed, the principal emitter is HCF for trimethyl phosphine and HF and the unknown emitter for triethyl phosphine. This detector may have important applications in investigations of the biogeochemical cycling of phosphorus. C1 UNIV COLORADO,DEPT CHEM & BIOCHEM,CAMPUS BOX 216,BOULDER,CO 80309. TENNESSEE TECHNOL UNIV,CTR MANAGEMENT UTILIZAT & PROTECT WATER RESOURCES,COOKEVILLE,TN 38505. TENNESSEE TECHNOL UNIV,DEPT CHEM,COOKEVILLE,TN 38505. UNIV COLORADO,NOAA,COOPERAT INST RES ENVIRONM SCI,BOULDER,CO 80309. RI Chasteen, Thomas/B-6601-2009; Birks, John/H-7451-2013 OI Birks, John/0000-0003-1691-1354 NR 27 TC 15 Z9 16 U1 0 U2 4 PU FRIEDR VIEWEG SOHN VERLAG GMBH PI WIESBADEN 1 PA PO BOX 5829, W-6200 WIESBADEN 1, GERMANY SN 0009-5893 J9 CHROMATOGRAPHIA JI Chromatographia PD APR PY 1991 VL 31 IS 7-8 BP 342 EP 346 DI 10.1007/BF02262189 PG 5 WC Biochemical Research Methods; Chemistry, Analytical SC Biochemistry & Molecular Biology; Chemistry GA FK596 UT WOS:A1991FK59600004 ER PT J AU EDWARDS, SF AF EDWARDS, SF TI THE DEMAND FOR GALAPAGOS VACATIONS - ESTIMATION AND APPLICATION TO WILDERNESS PRESERVATION SO COASTAL MANAGEMENT LA English DT Article DE ECOTOURISM; GALAPAGOS ISLANDS; DEMAND; TAXES; CARRYING CAPACITY AB The demand for Galapagos vacations by ecotourists was estimated using hedonic demand analysis, a technique being developed by environmental economists. In turn, the demand model was used to explore how a fiscal policy of maximizing tax revenues could help to satisfy the alleged incompatible goals of wilderness preservation and economic growth. Constrained to a carrying capacity of 125,000 visitor days, there is potential to raise about $30 million (U.S.) by substantially increasing the entrance fee charged to ecotourists. This tax revenue could be used to finance both conservation of the Galapagos wilderness and investment in Ecuador's economy. RP EDWARDS, SF (reprint author), NOAA,NATL MARINE FISHERIES SERV,NE FISHERIES CTR,WATER ST,WOODS HOLE,MA 02543, USA. NR 0 TC 3 Z9 3 U1 2 U2 5 PU TAYLOR & FRANCIS PI BRISTOL PA 1900 FROST ROAD, SUITE 101, BRISTOL, PA 19007-1598 SN 0892-0753 J9 COAST MANAGE JI Coast. Manage. PD APR-JUN PY 1991 VL 19 IS 2 BP 155 EP 169 DI 10.1080/08920759109362137 PG 15 WC Environmental Sciences; Environmental Studies SC Environmental Sciences & Ecology GA GD178 UT WOS:A1991GD17800001 ER PT J AU GOZANI, J AF GOZANI, J TI 2-SCALE EXPANSION OF WAVE-PROPAGATION IN A RANDOM MEDIUM SO COMPUTER PHYSICS COMMUNICATIONS LA English DT Article AB This paper presents an innovative technique for performing partial inversion of the operator of a wide class of transport-like equations encountered in mathematical physics. This inversion is an alternative to the traditional selective summation technique of the iterated series solution to a corresponding Volterra integral equation. Comparing with the regular iterated series for which the zero-order iterate is the worst approximation, it was computationally found that our zero-order term has an exact high-frequency and acceptable low-frequency content. It is suggested that the first iteration that reflects a single scattering event will compensate for the inaccuracy in the low-frequency region. Thus two terms in the series will be a sufficient approximation for practical purposes, eliminating the need for higher iterations. C1 NOAA,ENVIRONM RES LABS,WAVE PROPAGAT LAB,BOULDER,CO 80303. RP GOZANI, J (reprint author), UNIV COLORADO,NOAA,COOPERAT INST RES ENVIRONM SCI,BOULDER,CO 80309, USA. NR 9 TC 3 Z9 3 U1 0 U2 0 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0010-4655 J9 COMPUT PHYS COMMUN JI Comput. Phys. Commun. PD APR PY 1991 VL 65 IS 1-3 BP 117 EP 120 DI 10.1016/0010-4655(91)90162-E PG 4 WC Computer Science, Interdisciplinary Applications; Physics, Mathematical SC Computer Science; Physics GA FM805 UT WOS:A1991FM80500016 ER PT J AU PALMER, DR GEORGES, TM JONES, RM AF PALMER, DR GEORGES, TM JONES, RM TI CLASSICAL CHAOS AND THE SENSITIVITY OF THE ACOUSTIC FIELD TO SMALL-SCALE OCEAN STRUCTURE SO COMPUTER PHYSICS COMMUNICATIONS LA English DT Article ID FLORIDA; STRAITS AB Ray theory is usually the basis of data inversion schemes for acoustic remote sensing of the ocean. Chaotic ray paths are expected to be present whenever the ocean environment possesses small-scale, range-dependent structure. We are studying the implications of their presence for data inversion schemes. Using numerical simulations we consider ray-path characteristics for acoustic remote sensing of the Florida Current. We find small-scale bathymetric structure results in chaotic ray paths and an exponential proliferation of eigenrays. As a result, for each feature in the time-of-arrival pattern, there is associated not a single eigenray but a group, thereby limiting the spatial resolution of a remote sensing system. C1 NOAA,WAVE PROPAGAT LAB,BOULDER,CO 80303. RP PALMER, DR (reprint author), NOAA,ATLANTIC OCEANOG & METEOROL LAB,4301 RICKENBACKER CSWY,MIAMI,FL 33149, USA. OI JONES, RICHARD MICHAEL/0000-0002-9493-7456 NR 11 TC 20 Z9 20 U1 0 U2 1 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0010-4655 J9 COMPUT PHYS COMMUN JI Comput. Phys. Commun. PD APR PY 1991 VL 65 IS 1-3 BP 219 EP 223 DI 10.1016/0010-4655(91)90174-J PG 5 WC Computer Science, Interdisciplinary Applications; Physics, Mathematical SC Computer Science; Physics GA FM805 UT WOS:A1991FM80500028 ER PT J AU SHANG, EC WANG, YY AF SHANG, EC WANG, YY TI OCEAN ACOUSTIC FIELD SIMULATIONS FOR MONITORING LARGE-SCALE OCEAN STRUCTURES SO COMPUTER PHYSICS COMMUNICATIONS LA English DT Article ID GROUP-VELOCITY; TOMOGRAPHY; SOFAR AB Substantial numerical simulations of low-frequency acoustic field under different ocean models have been carried out on the CYBER-205 at WPL/NOAA. The purpose of these numerical simulations is to investigate our potential ability to monitor large-scale ocean structures by using modal ocean acoustic tomography (MOAT). For example, the possibility of monitoring El Nino by using MOAT has been illustrated. C1 NOAA,WAVE PROPAGAT LAB,BOULDER,CO 80303. RP SHANG, EC (reprint author), UNIV COLORADO,COOPERAT INST RES ENVIRONM SCI,325 BROADWAY,BOULDER,CO 80303, USA. NR 13 TC 1 Z9 2 U1 0 U2 0 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0010-4655 J9 COMPUT PHYS COMMUN JI Comput. Phys. Commun. PD APR PY 1991 VL 65 IS 1-3 BP 238 EP 245 DI 10.1016/0010-4655(91)90177-M PG 8 WC Computer Science, Interdisciplinary Applications; Physics, Mathematical SC Computer Science; Physics GA FM805 UT WOS:A1991FM80500031 ER PT J AU ANTONUCCI, JM FOWLER, BO VENZ, S AF ANTONUCCI, JM FOWLER, BO VENZ, S TI FILLER SYSTEMS BASED ON CALCIUM METAPHOSPHATES SO DENTAL MATERIALS LA English DT Article AB Calcium metaphosphates (CMP's) - a unique class of phosphate minerals possessing polymeric structures, [Ca(PO3)2]n, and having refractive indices of approximately 1.54-1.59 - are optically compatible with resins such as BIS-GMA. In this study, several types of CMP's were prepared and evaluated for their potential as fillers for visible-light-activated (VLA) dental composites. The vitreous (V) and beta-crystalline forms of CMP were prepared by controlled thermolysis of monocalcium phosphate monohydrate, Ca(H2PO4)2 .H2O. Hybrid fillers were also prepared by thermal methods. Fillers, characterized by IR spectroscopy and optical microscopy, were prepared in several size ranges (e.g., 1-100-mu-m). VLA composites were formulated by use of both untreated and surface modified CMP's. V-CMP and its hybrids yielded composites which expanded when stored in water but were of low strength, e.g., diametral tensile strength, (DTS) = 8 MPa. beta-CMP composites were more moisture-resistant, had higher DTS's (from 12 to 33 MPa), and showed a tendency to arrest brittle fracture. These novel fillers have potential uses in resin-based materials such as dental composites, cements, and adhesives. RP ANTONUCCI, JM (reprint author), NATL INST STAND & TECHNOL,GAITHERSBURG,MD 20899, USA. NR 0 TC 20 Z9 20 U1 0 U2 0 PU ACAD DENTAL MATERIALS PI DALLAS PA BAYLOR COLLEGE DENTISTRY, 3302 GASTON AVE, DALLAS, TX 75266-0677 SN 0109-5641 J9 DENT MATER JI Dent. Mater. PD APR PY 1991 VL 7 IS 2 BP 124 EP 129 DI 10.1016/0109-5641(91)90058-7 PG 6 WC Dentistry, Oral Surgery & Medicine; Materials Science, Biomaterials SC Dentistry, Oral Surgery & Medicine; Materials Science GA FF353 UT WOS:A1991FF35300010 PM 1936640 ER PT J AU OCONNOR, TP EHLER, CN AF OCONNOR, TP EHLER, CN TI RESULTS FROM THE NOAA NATIONAL STATUS AND TRENDS PROGRAM ON DISTRIBUTION AND EFFECTS OF CHEMICAL CONTAMINATION IN THE COASTAL AND ESTUARINE UNITED-STATES SO ENVIRONMENTAL MONITORING AND ASSESSMENT LA English DT Article AB The NOAA National Status and Trends (NS&T) Program has been monitoring chemical contamination in fish livers, and surface sediments since 1984 and in molluscan tissue and sediments since 1986. Data from fine-grained sediment at 175 sites are used to describe the spatial distribution of contamination throughout the coastal and estuarine United States. Highest levels are generally found in, and considered representative of, urban areas. It should be noted, however, that these levels are not as high as have been found near discharge pipes or in isolated industrial areas through other monitoring efforts. Dramatic biological responses, such as liver tumors in fish or apparently toxic contaminant levels in sediment, are found infrequently. Subtle biological changes, especially those that affect reproductive ability, are being sought. Data from three annual collections of mollusks have been used to identify early signals of temporal trends in contamination at NS&T sites. RP OCONNOR, TP (reprint author), NOAA,NATL OCEAN SERV,OFF OCEANOG & MARINE ASSESSMENT,ROCKVILLE,MD 20852, USA. NR 0 TC 45 Z9 48 U1 0 U2 2 PU KLUWER ACADEMIC PUBL PI DORDRECHT PA SPUIBOULEVARD 50, PO BOX 17, 3300 AA DORDRECHT, NETHERLANDS SN 0167-6369 J9 ENVIRON MONIT ASSESS JI Environ. Monit. Assess. PD APR PY 1991 VL 17 IS 1 BP 33 EP 49 DI 10.1007/BF00402460 PG 17 WC Environmental Sciences SC Environmental Sciences & Ecology GA FG673 UT WOS:A1991FG67300003 PM 24233372 ER PT J AU HUGHES, EE DAVENPORT, AJ WOODS, PT ZIELINSKI, WL AF HUGHES, EE DAVENPORT, AJ WOODS, PT ZIELINSKI, WL TI INTERCOMPARISON OF A RANGE OF PRIMARY GAS STANDARDS OF CARBON-MONOXIDE IN NITROGEN AND CARBON-DIOXIDE IN NITROGEN PREPARED BY THE NATIONAL-INSTITUTE-OF-STANDARDS-AND-TECHNOLOGY AND THE NATIONAL-PHYSICAL-LABORATORY SO ENVIRONMENTAL SCIENCE & TECHNOLOGY LA English DT Article AB Measurements were carried out by the National Physical Laboratory (NPL) in the United Kingdom and the National Institute of Standards and Technology (NIST) in the United States to intercompare the primary gravimetric gas standards developed by these two laboratories. These intercomparisons involved analyses of a set of CO and CO2 NIST Standard Reference Materials by the NPL, and of a similar set of NPL primary standards by the NIST. In each case, the exact concentrations of the exchanged sets were unknown to the analyzing laboratory. The CO and CO2 standards ranged in nominal concentration from 8% to 10 ppm and from 8% to 0.5%, respectively. The analyses were carried out using primary gravimetric standards, which were independently produced by the two laboratories. The mean difference between the values assigned by the supplying laboratory and the values determined by the analyzing laboratory was less than 0.2% relative for both sets of CO and CO2 standards. The results confirmed that standards produced by NPL and NIST have a high degree of consistency, and that measurements obtained using these standards for measurements of levels of atmospheric CO and CO2 may be directly intercompared. C1 NATL INST STAND & TECHNOL,CTR ANALYT CHEM,DIV GAS & PARTICULATE SCI,GAITHERSBURG,MD 20899. NATL PHYS LAB,DIV QUANTUM METROL,TEDDINGTON TW11 0LW,MIDDX,ENGLAND. NR 2 TC 5 Z9 5 U1 0 U2 0 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 APR PY 1991 VL 25 IS 4 BP 671 EP 676 DI 10.1021/es00016a010 PG 6 WC Engineering, Environmental; Environmental Sciences SC Engineering; Environmental Sciences & Ecology GA FE652 UT WOS:A1991FE65200018 ER PT J AU GOEBEL, ME BENGTSON, JL DELONG, RL GENTRY, RL LOUGHLIN, TR AF GOEBEL, ME BENGTSON, JL DELONG, RL GENTRY, RL LOUGHLIN, TR TI DIVING PATTERNS AND FORAGING LOCATIONS OF FEMALE NORTHERN FUR SEALS SO FISHERY BULLETIN LA English DT Article AB Nine lactating northern fur seals Callorhinus ursinus from St. Paul Island, Alaska, were instrumented with time-depth recorders and head-mounted radio transmitters in July and August 1985. Seven females were subsequently located at least once while at sea. Diving patterns obtained from females' time-depth recorders were then associated with their foraging locations. Generally two diving patterns were found; shallow-diving and deep-diving. The deep-diving pattern appears to be associated with feeding throughout the day over the continental shelf in water less than 200 m deep. The shallow-diving pattern is generally restricted to nighttime hours and probably occurs mostly over deep water. An analysis of the occurrence of food in stomachs of lactating fur seals collected in the eastern Bering Sea from 1958 to 1974 also suggests that seals collected over the continental shelf were more likely to be feeding during the day. We examine differences in the way shallow- and deep-diving females forage and discuss possible prey associated with the two diving patterns. RP GOEBEL, ME (reprint author), NOAA,NATL MARINE FISHERIES SERV,ALASKA FISHERIES SCI CTR,NATL MARINE MAMMAL LAB,SEATTLE,WA 98115, USA. NR 14 TC 69 Z9 71 U1 1 U2 4 PU NATL MARINE FISHERIES SERVICE SCIENTIFIC PUBL OFFICE PI SEATTLE PA 7600 SAND POINT WAY NE BIN C15700, SEATTLE, WA 98115 SN 0090-0656 J9 FISH B-NOAA JI Fish. Bull. PD APR PY 1991 VL 89 IS 2 BP 171 EP 179 PG 9 WC Fisheries SC Fisheries GA FR767 UT WOS:A1991FR76700001 ER PT J AU GOVONI, JJ OLNEY, JE AF GOVONI, JJ OLNEY, JE TI POTENTIAL PREDATION ON FISH EGGS BY THE LOBATE CTENOPHORE MNEMIOPSIS-LEIDYI WITHIN AND OUTSIDE THE CHESAPEAKE BAY PLUME SO FISHERY BULLETIN LA English DT Article ID NARRAGANSETT BAY; ANCHOA-MITCHILLI; BRITISH-COLUMBIA; LARVAL FISH; MCCRADYI; PREY AB In Chesapeake Bay in June, the predatory lobate ctenophore Mnemiopsis leidyi and the eggs of the bay anchovy Anchoa mitchilli typically reach seasonal and localized abundance together. When examined at small vertical (1-3m), horizontal (10-50m), and temporal (6-hour) scales, the co-occurrence of M. leidyi and fish eggs (32.3-74.2% of which were A. mitchilli) was greatest in the northern reaches of the mouth of Chesapeake Bay, where the water column was stratified. Stratification to the south was effected by the Chesapeake Bay plume. With estimates of ctenophore clearance rate reported elsewhere and observed densities of ctenophores and fish eggs, potential predation was judged to be greatest in the northern reaches of the Bay mouth. The observation that co-occurrence and potential predation are greatest in areas where Chesapeake Bay water mixes with coastal shelf water implies that those fishes that spawn in low-salinity surface waters of well-stratified water columns may afford protection of their eggs from ctenophore predation. C1 COLL WILLIAM & MARY,SCH MARINE SCI,VIRGINIA INST MARINE SCI,GLOUCESTER POINT,VA 23062. RP GOVONI, JJ (reprint author), NOAA,NATL MARINE FISHERIES SERV,SE FISHERIES SCI CTR,BEAUFORT LAB,BEAUFORT,NC 28516, USA. NR 26 TC 17 Z9 17 U1 2 U2 3 PU NATL MARINE FISHERIES SERVICE SCIENTIFIC PUBL OFFICE PI SEATTLE PA 7600 SAND POINT WAY NE BIN C15700, SEATTLE, WA 98115 SN 0090-0656 J9 FISH B-NOAA JI Fish. Bull. PD APR PY 1991 VL 89 IS 2 BP 181 EP 186 PG 6 WC Fisheries SC Fisheries GA FR767 UT WOS:A1991FR76700002 ER PT J AU KRAMER, SH AF KRAMER, SH TI GROWTH, MORTALITY, AND MOVEMENTS OF JUVENILE CALIFORNIA HALIBUT PARALICHTHYS-CALIFORNICUS IN SHALLOW COASTAL AND BAY HABITATS OF SAN-DIEGO COUNTY, CALIFORNIA SO FISHERY BULLETIN LA English DT Article ID SOUTHERN-CALIFORNIA; LARVAL FISHES; TRANSPORT; FLOUNDER AB Growth and mortality rates were compared for juvenile California halibut Paralichtys californicus from bay and open coast habitats. Growth was estimated by determination of size-at-age using daily increments in otoliths. No significant difference was observed in size-at-age for juvenile halibut between 6 and 41 mm from the bays and open coast. However, age-specific mortality rates estimated for halibut < 70 days were highest for newly-settled halibut on the open coast. California halibut settled either in bays or on the open coast, but ultimately nearly all of the halibut that settled on the coast entered and used the bays as nursery areas during their first year of life or else they died. The advantages of bays as nursery areas may be a decrease in risk of mortality of newly-settled halibut and an increase in growth of larger juveniles that feed upon the abundant small fishes in the bays. C1 NOAA,NATL MARINE FISHERIES SERV,SW FISHERIES SCI CTR,LA JOLLA,CA 92038. NR 52 TC 46 Z9 46 U1 0 U2 2 PU NATL MARINE FISHERIES SERVICE SCIENTIFIC PUBL OFFICE PI SEATTLE PA 7600 SAND POINT WAY NE BIN C15700, SEATTLE, WA 98115 SN 0090-0656 J9 FISH B-NOAA JI Fish. Bull. PD APR PY 1991 VL 89 IS 2 BP 195 EP 207 PG 13 WC Fisheries SC Fisheries GA FR767 UT WOS:A1991FR76700004 ER PT J AU MUNROE, TA AF MUNROE, TA TI WESTERN ATLANTIC TONGUEFISHES OF THE SYMPHURUS-PLAGUSIA COMPLEX (CYNOGLOSSIDAE, PLEURONECTIFORMES), WITH DESCRIPTIONS OF 2 NEW SPECIES SO FISHERY BULLETIN LA English DT Article AB Western Atlantic tonguefishes of the Symphurus plagusia (Schneider, in Bloch and Schneider 1801) complex are distinguished from other Atlantic Symphurus species by the possession of 12 caudal fin rays, a 1-4-3 pattern of interdigitation of dorsal-fin pterygiophores and neural spines, absence of a pupillary operculum, reduced or absent dentition on ocular-side jaws, and an unpigmented peritoneum. Considerable taxonomic uncertainty has been associated with nominal species of this complex, but the most common practice has been to recognize one widespread species (S. plagusia) with two subspecies ranging from the Caribbean southward to Uruguay, and a second species, S. civitatium Ginsburg 1951, occurring in inshore areas along the southeastern and Gulf of Mexico coasts of the United States and northern Mexico. The validity of S. civitatium is confirmed in this study. Examination of tonguefishes from the Caribbean and southward indicates that specimens previously identified as S. plagusia do not comprise one species with two allopatric subspecies, but rather four largely sympatric, albeit not necessarily syntopic, species. Symphurus plagusia, the first described species in this complex, occurs in inshore habitats ranging from the Caribbean to Rio de Janeiro. Symphurus tessellatus (Quoy and Gaimard 1824), removed from the synonymy of S. plagusia, occurs in nearshore, estuarine, and neritic waters throughout the Caribbean southwards to Uruguay. Two new species, S. oculellus occurring in neritic waters off northern South America (Guyana to northern Brazil), and S. caribbeanus (nearshore habitats throughout the Caribbean), are described and figured. A key to the western Atlantic species of this complex is provided. RP MUNROE, TA (reprint author), NOAA,NATL MARINE FISHERIES SERV,NATL MUSEUM NAT HIST,SYST LAB,WASHINGTON,DC 20560, USA. NR 79 TC 12 Z9 12 U1 0 U2 0 PU NATL MARINE FISHERIES SERVICE SCIENTIFIC PUBL OFFICE PI SEATTLE PA 7600 SAND POINT WAY NE BIN C15700, SEATTLE, WA 98115 SN 0090-0656 J9 FISH B-NOAA JI Fish. Bull. PD APR PY 1991 VL 89 IS 2 BP 247 EP 287 PG 41 WC Fisheries SC Fisheries GA FR767 UT WOS:A1991FR76700008 ER PT J AU SOMERTON, DA KOBAYASHI, DR AF SOMERTON, DA KOBAYASHI, DR TI ROBUSTNESS OF THE WETHERALL LENGTH-BASED METHOD TO POPULATION DISEQUILIBRIA SO FISHERY BULLETIN LA English DT Article ID HAWAIIAN AB For fish populations in equilibrium, estimates of Z/K and L infinity can be obtained solely from length-frequency data by using the Wetherall length-based method. Robustness of this method to departures from equilibrium conditions is examined with a population simulation model. During disequilibrium conditions following either the initiation of a fishery or a 1-year perturbation in recruitment, estimates of both parameters, especially Z/K, are severely biased. Three-year averaging of catch length-frequencies does not substantially reduce this bias. A test, based on the chi-square statistic, is proposed for detecting population disequilibrium. Provided that the sizes of length-frequency samples are sufficiently large, the test is an effective way to detect population disequilibrium and thereby avoid biased parameter estimates. RP SOMERTON, DA (reprint author), NOAA,NATL MARINE FISHERIES SERV,SW FISHERIES SCI CTR,HONOLULU LAB,2570 DOLE ST,HONOLULU,HI 96822, USA. NR 12 TC 3 Z9 3 U1 0 U2 0 PU NATL MARINE FISHERIES SERVICE SCIENTIFIC PUBL OFFICE PI SEATTLE PA 7600 SAND POINT WAY NE BIN C15700, SEATTLE, WA 98115 SN 0090-0656 J9 FISH B-NOAA JI Fish. Bull. PD APR PY 1991 VL 89 IS 2 BP 307 EP 314 PG 8 WC Fisheries SC Fisheries GA FR767 UT WOS:A1991FR76700011 ER PT J AU SUTTER, FC WILLIAMS, RO GODCHARLES, MF AF SUTTER, FC WILLIAMS, RO GODCHARLES, MF TI MOVEMENT PATTERNS AND STOCK AFFINITIES OF KING MACKEREL IN THE SOUTHEASTERN UNITED-STATES SO FISHERY BULLETIN LA English DT Article ID SCOMBEROMORUS-CAVALLA; BIOLOGY AB King mackerel Scomberomorus cavalla were tagged and released from southeastern Florida, the Florida Keys, and South Carolina from 1975 through 1979 to document spatial and temporal movement patterns. Distance traveled by tagged king mackerel was not significantly related to size (fork length), but was correlated with number of days-at-large. King mackerel show a cyclical pattern of movement along the Atlantic seaboard of the southeastern United States and coastal waters of the Gulf of Mexico. A migratory behavior may exist in which fish return to the area of release over a period of up to 5 years. The number of fish moving away from the area of release and their direction of movement depend on whether the fish are associated with Atlantic or Gulf waters. Some king mackerel may be residents in southeastern Florida waters. The seasonal overlap between the two recognized stocks of king mackerel in southeastern Florida is estimated to be as high as 29.4-41.8%. C1 FLORIDA MARINE FISHERIES COMMISS,TALLAHASSEE,FL 32301. NOAA,NATL MARINE FISHERIES SERV,ST PETERSBURG,FL 33702. RP SUTTER, FC (reprint author), FLORIDA MARINE RES INST,DEPT NAT RESOURCES,100 8TH AVE SE,ST PETERSBURG,FL 33701, USA. NR 19 TC 18 Z9 21 U1 1 U2 4 PU NATL MARINE FISHERIES SERVICE SCIENTIFIC PUBL OFFICE PI SEATTLE PA 7600 SAND POINT WAY NE BIN C15700, SEATTLE, WA 98115 SN 0090-0656 J9 FISH B-NOAA JI Fish. Bull. PD APR PY 1991 VL 89 IS 2 BP 315 EP 324 PG 10 WC Fisheries SC Fisheries GA FR767 UT WOS:A1991FR76700012 ER PT J AU LOWRY, MS STEWART, BS HEATH, CB YOCHEM, PK FRANCIS, JM AF LOWRY, MS STEWART, BS HEATH, CB YOCHEM, PK FRANCIS, JM TI SEASONAL AND ANNUAL VARIABILITY IN THE DIET OF CALIFORNIA SEA LIONS ZALOPHUS-CALIFORNIANUS AT SAN-NICOLAS-ISLAND, CALIFORNIA, 1981-86 SO FISHERY BULLETIN LA English DT Article ID ROGUE RIVER; PREY; OREGON; HABITS C1 HUBBS MARINE RES CTR,SEA WORLD RES INST,SAN DIEGO,CA 92109. FULLERTON COLL,FULLERTON,CA 92634. SMITHSONIAN INST,NATL ZOOL PK,WASHINGTON,DC 20008. RP LOWRY, MS (reprint author), NOAA,NATL MARINE FISHERIES SERV,SW FISHERIES SCI CTR,POB 271,LA JOLLA,CA 92038, USA. NR 25 TC 50 Z9 52 U1 1 U2 7 PU NATL MARINE FISHERIES SERVICE SCIENTIFIC PUBL OFFICE PI SEATTLE PA 7600 SAND POINT WAY NE BIN C15700, SEATTLE, WA 98115 SN 0090-0656 J9 FISH B-NOAA JI Fish. Bull. PD APR PY 1991 VL 89 IS 2 BP 331 EP 336 PG 6 WC Fisheries SC Fisheries GA FR767 UT WOS:A1991FR76700014 ER PT J AU WYSS, M AF WYSS, M TI INCREASED MEAN DEPTH OF EARTHQUAKES AT PARKFIELD SO GEOPHYSICAL RESEARCH LETTERS LA English DT Article ID SAN-ANDREAS FAULT; CALIFORNIA; ZONE AB The mean focal depth of earthquakes in the northern and southern parts of the Parkfield segment of the San Andreas fault was greater than long term average by 1 km during the last 4 years approximately. It is proposed that this is a precursor to the next characteristic Parkfield earthquake, because the same phenomenon occurred before at least three other mainshocks along the San Andreas fault. In the northern segment the increase in mean depth is mostly due to reduction of shallow activity, in the southern segment deeper than usual activity seems to have increased. Within about 8 km from the 1966 epicenter no significant increase of mean depth is observed, but seismic quiescence [Wyss et al., 1990a] and a decrease in deformation rate [Wyss et al., 1990b] was documented. These observations are interpreted to suggest that the precursory process at Parkfield varies along strike, and that the next rupture may extend further north than the last one. RP WYSS, M (reprint author), UNIV COLORADO,NOAA,COOPERAT INST RES ENVIRONM SCI,DEPT GEOL SCI,CAMPUS BOX 216,BOULDER,CO 80309, USA. NR 20 TC 5 Z9 5 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 APR PY 1991 VL 18 IS 4 BP 617 EP 620 DI 10.1029/91GL00819 PG 4 WC Geosciences, Multidisciplinary SC Geology GA FG828 UT WOS:A1991FG82800011 ER PT J AU VELINSKY, DJ FOGEL, ML TODD, JF TEBO, BM AF VELINSKY, DJ FOGEL, ML TODD, JF TEBO, BM TI ISOTOPIC FRACTIONATION OF DISSOLVED AMMONIUM AT THE OXYGEN-HYDROGEN SULFIDE INTERFACE IN ANOXIC WATERS SO GEOPHYSICAL RESEARCH LETTERS LA English DT Article ID DELAWARE ESTUARY; BLACK-SEA; NITROGEN AB The delta-N-15 of dissolved ammonium was determined in three anoxic marine basins: Black Sea, Saanich Inlet, B.C., Canada, and Framvaren Fjord, Norway. In each basin, the delta-N-15-NH4+ was greatest near the O2/H2S interface, with delta-N-15 as high as +21 parts-per-thousand. The depth distributions of NH4+ and delta-N-15-NH4+ for Black Sea and Framvaren Fjord were examined with a one-dimensional, steady-state, vertical advection-diffusion model to calculate the isotope fractionation during the consumption of NH4+ by bacteria. Isotope enrichments, epsilon, for Black Sea were between 5 and 15 parts-per-thousand, whereas in Framvaren Fjord epsilon ranged from 20 to 30 parts-per-thousand. These differences are related mainly to the ambient concentration of NH4+. Biosynthetic uptake of NH4+ rather than nitrification was responsible for the fractionation. The delta-N-15-NH4+ in Saanich Inlet appears related to in-situ regeneration of NH4+ with little isotopic fractionation between dissolved and particulate nitrogen (PN). C1 NOAA,OFF GLOBAL PROGRAMS,SILVER SPRING,MD 20910. UNIV CALIF SAN DIEGO,SCRIPPS INST OCEANOG,DIV MARINE BIOL RES,LA JOLLA,CA 92093. RP VELINSKY, DJ (reprint author), CARNEGIE INST WASHINGTON,GEOPHYS LAB,5251 BROAD BRANCH RD NW,WASHINGTON,DC 20015, USA. RI Fogel, Marilyn/M-2395-2015; Tebo, Bradley/A-8432-2017 OI Fogel, Marilyn/0000-0002-1176-3818; Tebo, Bradley/0000-0002-6301-4325 NR 19 TC 30 Z9 30 U1 2 U2 12 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 APR PY 1991 VL 18 IS 4 BP 649 EP 652 DI 10.1029/91GL00344 PG 4 WC Geosciences, Multidisciplinary SC Geology GA FG828 UT WOS:A1991FG82800019 ER PT J AU MAUL, GA HANSON, K AF MAUL, GA HANSON, K TI INTERANNUAL COHERENCE BETWEEN NORTH-ATLANTIC ATMOSPHERIC SURFACE PRESSURE AND COMPOSITE SOUTHERN USA SEA-LEVEL SO GEOPHYSICAL RESEARCH LETTERS LA English DT Article ID WINTER AB Annual mean sea levels along the southern United States have been examined for interannual variability. Fifteen sea level stations from Cape Hatteras to the Rio Grande that best covered the three lunar nodal cycles from 1931-1987 were selected for analysis. Linear trends, ranging from +0.2 cm/yr to +1.4 cm/yr were subtracted from their respective series, leaving remarkably similar residuals. The composite time series of the 15 residuals was compared with time series of surface air pressure over the North Atlantic Ocean during the period 1947-1987. The best correlation is a negative relationship between composite sea level and wintertime air pressure north of 45-degrees-N, and a positive relationship from 20-degrees-45-degrees-N. The most significant correlations (-0.73 and +0.51) were found for 60-degrees-N, 20-degrees-W and for 30-degrees-N, 25-degrees-W respectively. Wintertime meridional air pressure gradient between these two latitudes represents about 50% of the variance in composite annual mean sea level. Both the sea level and air pressure time series had significant spectral peaks at 13.3 and 4.4 years, with about 52% of the covariance coming from these two periods. C1 NOAA,AIR RESOURCES LAB,ROCKVILLE,MD 20852. RP MAUL, GA (reprint author), NOAA,ATLANTIC OCEANOG & METEOROL LAB,4301 RICKENBACKER CAUSEWAY,MIAMI,FL 33149, USA. RI Maul, George/M-1629-2015 OI Maul, George/0000-0001-8413-7853 NR 16 TC 15 Z9 16 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 APR PY 1991 VL 18 IS 4 BP 653 EP 656 DI 10.1029/91GL00141 PG 4 WC Geosciences, Multidisciplinary SC Geology GA FG828 UT WOS:A1991FG82800020 ER PT J AU DESHLER, T HOFMANN, DJ AF DESHLER, T HOFMANN, DJ TI OZONE PROFILES AT MCMURDO STATION, ANTARCTICA, THE AUSTRAL SPRING OF 1990 SO GEOPHYSICAL RESEARCH LETTERS LA English DT Article ID TRANSPORT; HOLE AB Vertical profiles of ozone and temperature were measured on 40 occasions during the austral spring of 1990 at McMurdo Station, Antarctica, and once again near record levels of ozone depletion were observed. Total ozone decreased from 260 DU in late August to its minimum value of 145 DU on 9 October, when the ozonesonde was at it's lower detection limit from 15 to 16.5 km. Ozone reductions were observed almost exclusively between 12 and 20 km, with a half life of 20 days. This is similar to previous years. Although McMurdo was within the polar vortex for most of the period, there were several occasions when the edge of the vortex was over McMurdo. During these periods, ozone above 20 km approximately doubled, but below 20 km remained relatively unchanged. C1 NOAA,CLIMATE MONITORING & DIAGNOST LAB,BOULDER,CO 80303. RP DESHLER, T (reprint author), UNIV WYOMING,LARAMIE,WY 82071, USA. NR 8 TC 10 Z9 10 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 APR PY 1991 VL 18 IS 4 BP 657 EP 660 DI 10.1029/91GL00363 PG 4 WC Geosciences, Multidisciplinary SC Geology GA FG828 UT WOS:A1991FG82800021 ER EF