FN Thomson Reuters Web of Science™ VR 1.0 PT J AU DOSWELL, CA AF DOSWELL, CA TI FORECASTER WORKSTATION DESIGN - CONCEPTS AND ISSUES SO WEATHER AND FORECASTING LA English DT Editorial Material AB Some basic ideas about designing a meteorological workstation for operational weather forecasting are presented, in part as a complement to the recently published discussion of workstation design by R. R. Hoffman. Scientific weather forecasting is defined and used as a basis for developing a set of necessary structural capabilities in a workstation. These capabilities include: built-in excess capacity for flexibility, user-defined product menus, interactivity at the level of being able to change the data as well as analyzed fields, and a software suite of operators by which virtually any product can be custom built through concatenation of mathematically defined operations on any of the data resident within the workstation. The need for user involvement is stressed by showing an example of a real forecaster "workstation" that successfully provided most of these capabilities and, in contrast, by pointing out the flaws in the current National Weather Service operational workstation's development. In order to provide a system of maximum value, the users must be intimately involved in the process of system design, which virtually precludes the standard federal procurement process. A process of hardware and software purchases "off the shelf " is advocated, in combination with the establishment of on-site expertise to craft locally tailored workstations. The implications for the future of operational weather forecasting are discussed. RP DOSWELL, CA (reprint author), NOAA,ERL,NATL SEVERE STORMS LAB,1313 HALLEY CIRCLE,NORMAN,OK 73069, USA. RI Doswell III, Charles/E-7662-2010 NR 0 TC 4 Z9 4 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 1992 VL 7 IS 2 BP 398 EP 407 DI 10.1175/1520-0434(1992)007<0398:FWDCAI>2.0.CO;2 PG 10 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA HZ397 UT WOS:A1992HZ39700015 ER PT J AU TUCK, AF DAVIES, T HOVDE, SJ NOGUERALBA, M FAHEY, DW KAWA, SR KELLY, KK MURPHY, DM PROFFITT, MH MARGITAN, JJ LOEWENSTEIN, M PODOLSKE, JR STRAHAN, SE CHAN, KR AF TUCK, AF DAVIES, T HOVDE, SJ NOGUERALBA, M FAHEY, DW KAWA, SR KELLY, KK MURPHY, DM PROFFITT, MH MARGITAN, JJ LOEWENSTEIN, M PODOLSKE, JR STRAHAN, SE CHAN, KR TI POLAR STRATOSPHERIC CLOUD PROCESSED AIR AND POTENTIAL VORTICITY IN THE NORTHERN-HEMISPHERE LOWER STRATOSPHERE AT MIDLATITUDES DURING WINTER SO JOURNAL OF GEOPHYSICAL RESEARCH-ATMOSPHERES LA English DT Article ID ANTARCTIC OZONE EXPERIMENT; TOTAL REACTIVE NITROGEN; 1988/89 ARCTIC WINTER; ER-2 AIRCRAFT; INSITU OBSERVATIONS; VORTEX; TRACER; MODEL; DEHYDRATION; EXPEDITION AB Small-scale (<1000 km) features in ER-2 measurements of ClO, O3, H2O, N2O, and NOy outside the lower stratospheric Arctic vortex of 1988-1989 are compared with features on potential vorticity maps from the European Centre for Medium-range Weather Forecasts (ECMWF). The potential vorticity maps are obtained from T106 analyses and forecasts. Some of the plots have been truncated to lower resolution (T63 or T42) which smooths out the finer-scale structure. Comparison of these lower resolution plots shows how much detail is lost by excessive smoothing. It is also evident that the forecast plots lose fine-scale structure due to dissipation in the model resulting mainly from horizontal diffusion. We conclude that blobs of air on the maps at latitudes between the vortex edge and 25-degrees-N having potential vorticities characteristic of the vortex, did indeed originate from the vortex, but that the real atmosphere is more sharply differentiated (inhomogeneous) than the meteorological analyses, implying that the potential vorticity maps underestimate the amount of peeled-off material. Areal budgets of thc ex-vortex air are considered for ER-2 flight days, and are performed for 24-hour forecasts at T63, and analyses at T42, T63, and T106 resolution at theta = 475 K. Finally, it is concluded that the lower stratospheric Arctic vortex of 1988-1989 spread considerable amounts of air to mid-latitudes which had been processed by polar stratospheric clouds, and that this mechanism is a realistic explanation for the wintertime loss of ozone observed over northern mid-latitudes during the last decade. C1 UNIV COLORADO, NOAA, COOPERAT INST RES ENVIRONM SCI, COOPERAT INST ENVIRONM SCI, BOULDER, CO 80309 USA. NOAA, GEOPHYS FLUID DYNAM LAB, PRINCETON, NJ USA. JET PROP LAB, PASADENA, CA 91109 USA. NASA, AMES RES CTR, MOFFETT FIELD, CA 94035 USA. EUROPEAN CTR MEDIUM RANGE WEATHER FORECASTS, READING RG2 9AX, ENGLAND. RP TUCK, AF (reprint author), NOAA, AERON LAB, BOULDER, CO 80303 USA. RI Tuck, Adrian/F-6024-2011; Kawa, Stephan/E-9040-2012; Strahan, Susan/H-1965-2012; Murphy, Daniel/J-4357-2012; Fahey, David/G-4499-2013 OI Tuck, Adrian/0000-0002-2074-0538; Murphy, Daniel/0000-0002-8091-7235; Fahey, David/0000-0003-1720-0634 NR 44 TC 95 Z9 96 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 30 PY 1992 VL 97 IS D8 BP 7883 EP 7904 PG 22 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA HY079 UT WOS:A1992HY07900006 ER PT J AU KAWA, SR FAHEY, DW HEIDT, LE POLLOCK, WH SOLOMON, S ANDERSON, DE LOEWENSTEIN, M PROFFITT, MH MARGITAN, JJ CHAN, KR AF KAWA, SR FAHEY, DW HEIDT, LE POLLOCK, WH SOLOMON, S ANDERSON, DE LOEWENSTEIN, M PROFFITT, MH MARGITAN, JJ CHAN, KR TI PHOTOCHEMICAL PARTITIONING OF THE REACTIVE NITROGEN AND CHLORINE RESERVOIRS IN THE HIGH-LATITUDE STRATOSPHERE SO JOURNAL OF GEOPHYSICAL RESEARCH-ATMOSPHERES LA English DT Article ID ANTARCTIC OZONE HOLE; WINTER POLAR STRATOSPHERES; NITRIC-ACID TRIHYDRATE; 1988/89 ARCTIC WINTER; ER-2 AIRCRAFT; HETEROGENEOUS REACTIONS; HYDROGEN-CHLORIDE; CHEMICAL-COMPOSITION; INSITU OBSERVATIONS; SEPTEMBER 1987 AB Partitioning of the major components of the reactive nitrogen and inorganic chlorine reservoirs is derived from aircraft measurements in the lower stratosphere during the winter season in both hemispheres at latitudes of about 60-degrees to 80-degrees. The goal of this work is to exercise the power of the correlated set of measurements from polar missions of the NASA ER-2 to extend what can be learned from looking at the measurements individually. The results provide a consistent method for comparing distributions, and hence the controlling processes, between different areas of the near-polar regions. The analysis provides clear evidence of the effects of heterogeneous processes in the atmosphere. Values for NO2, ClONO2, N2O5, and Cl2O2 are derived in a simplified steady state model based on in situ NO, ClO, O3, temperature, and pressure measurements; laboratory-measured reaction rates; and modeled photodissociation rates. Values for the reservoir totals are independently derived from measurements of N2O, organic chlorine, and total reactive nitrogen. The relative abundances of the measured and derived species within the reservoirs are calculated, and the longer-lived species HCI and HNO3 are estimated as the residuals of their respective reservoirs. The resulting latitude distributions in the Arctic outside the vortex agree reasonably well with predictions of a two-dimensional photochemical model, indicating that partitioning in this region is largely controlled by standard homogeneous gas phase chemistry. Inside the Arctic vortex a large fraction of the HCl has been converted to reactive chlorine species CIO and Cl2O2, consistent with the extensive action of known heterogeneous reactions, presumably occurring on the surfaces of polar stratospheric clouds formed in the cold temperatures of the vortex. The partitioning in the Antarctic suggests that nearly the entire range of latitudes sampled by the ER-2 is affected by heterogeneous processes in situ, including that portion of the "collar" region equatorward of the nominal chemically perturbed region (CPR). Consideration of heterogeneous processing in the region outside the CPR is important in predicting the possible expansion of Antarctic ozone depletion and the transport of chemically perturbed air to lower latitudes. C1 COMPUTAT PHYS INC, ANNANDALE, VA USA. UNIV COLORADO, NOAA, COOPERAT INST RES ENVIRONM SCI, BOULDER, CO 80309 USA. NATL CTR ATMOSPHER RES, BOULDER, CO 80307 USA. NASA, AMES RES CTR, MOFFETT FIELD, CA 94035 USA. JET PROP LAB, PASADENA, CA 91109 USA. RP KAWA, SR (reprint author), NOAA, AERON LAB, 325 BROADWAY, BOULDER, CO 80303 USA. RI Kawa, Stephan/E-9040-2012; Fahey, David/G-4499-2013 OI Fahey, David/0000-0003-1720-0634 NR 79 TC 84 Z9 84 U1 0 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 30 PY 1992 VL 97 IS D8 BP 7905 EP 7923 PG 19 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA HY079 UT WOS:A1992HY07900007 ER PT J AU KAWA, SR FAHEY, DW KELLY, KK DYE, JE BAUMGARDNER, D GANDRUD, BW LOEWENSTEIN, M FERRY, GV CHAN, KR AF KAWA, SR FAHEY, DW KELLY, KK DYE, JE BAUMGARDNER, D GANDRUD, BW LOEWENSTEIN, M FERRY, GV CHAN, KR TI THE ARCTIC POLAR STRATOSPHERIC CLOUD AEROSOL - AIRCRAFT MEASUREMENTS OF REACTIVE NITROGEN, TOTAL WATER, AND PARTICLES SO JOURNAL OF GEOPHYSICAL RESEARCH-ATMOSPHERES LA English DT Article ID ANTARCTIC OZONE EXPERIMENT; NITRIC-ACID; CONDENSATION NUCLEI; LIDAR OBSERVATIONS; AIRBORNE LIDAR; JANUARY 24; WINTER; DEHYDRATION; EXPEDITION; DENITRIFICATION AB The reactive nitrogen (NOy), total water, and particle components of the polar stratospheric cloud (PSC) aerosol in the Arctic am studied using in situ aircraft measurements in the lower stratosphere. The results are compared to findings from the Antarctic derived using similar measurements and interpretive techniques. The Arctic data show that particle volume well above background values is present at temperatures above the frostpoint. confirming the result from the Antarctic that the observed PSC's are not water ice particles. NOy measurements inside a PSC are enhanced above ambient values consistent with anisokinetic sampling of particles containing NOy. Furthermore, relative changes in the measured particle volume along a flight track are well correlated with changes in the amount of NOy estimated to be in the particle phase. With the exception of data from one flight, assuming that the composition of the PSC particles is nitric acid trihydrate (NAT), the HNO3 content of the measured panicle volume is consistent with the amount of HNO3 Predicted to be available for condensation. To this extent, the Arctic observations are consistent with NAT as the composition of PSC panicles, in agreement With the Antarctic findings. In the Arctic data over long segments of several flights, calculations show saturation with respect to NAT without significant PSC particle growth above background. PSCs in the Arctic are not observed in situ until the apparent saturation ratio of HNO3 with respect to NAT is greater than 10, in marked contrast to the Antarctic, where PSCs are observed in conditions of apparent HNO3 saturation of 1 and above. This difference cannot be resolved by known measurement uncertainties. Also, a discrepancy is noted in the comparison of the amount of condensed HNO3 derived from the particle distribution measurements with that derived from the NO, measurements, assuming a NAT composition for the particles. Although thc relative variations in the derived quantities are similar, as in the Antarctic, the mean values consistently disagree by about a factor of 2. The differences suggest that there may be systematic errors in the data and/or physical assumptions used in the analysis. Several possibilities are discussed. C1 NATL CTR ATMOSPHER RES, BOULDER, CO 80307 USA. NASA, AMES RES CTR, MOFFETT FIELD, CA 94035 USA. RP KAWA, SR (reprint author), NOAA, AERON LAB, 325 BROADWAY, BOULDER, CO 80303 USA. RI Kawa, Stephan/E-9040-2012; Fahey, David/G-4499-2013 OI Fahey, David/0000-0003-1720-0634 NR 52 TC 65 Z9 65 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 30 PY 1992 VL 97 IS D8 BP 7925 EP 7938 PG 14 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA HY079 UT WOS:A1992HY07900008 ER PT J AU SOLOMON, S KEYS, JG AF SOLOMON, S KEYS, JG TI SEASONAL-VARIATIONS IN ANTARCTIC NOX CHEMISTRY SO JOURNAL OF GEOPHYSICAL RESEARCH-ATMOSPHERES LA English DT Article ID NEAR-ULTRAVIOLET SPECTROSCOPY; STRATOSPHERIC NO2; MCMURDO STATION; MIDDLE ATMOSPHERE; OZONE DEPLETION; O-3; CHLORINE; VORTEX; MODEL; DESTRUCTION AB Observations of the NO2 column and its diurnal variation provide an important test of aspects of stratospheric chemistry. Measurements of NO2 from two sites in the Antarctic are compared with model calculations that include a detailed treatment of diurnal NOx chemistry for fall, winter, and spring. Observed slant column amounts in spring provide strong evidence for important heterogeneous effects, probably through polar stratospheric cloud chemistry. It is shown that the slow growth of NO2 column observed during September is consitent with release of NO2 from N2O5 formed above the altitudes where polar stratospheric clouds occur. The observed early fall column amounts are in good agreement with model calculations, and the sharp onset of diurnal variation in column NO2 obtained near day 57 is well stimulated. Following this period, gas-phase model calculations suggest that N2O5 will rapidly accumulate during the Antarctic fall as nights become longer. It is suggested that the high latitude fall period during which N2O5 grows rapidly represents an optimum time to search for evidence of possible heterogeneous chemistry on background aerosols. C1 DSIR, LAUDER, NEW ZEALAND. RP SOLOMON, S (reprint author), NOAA, AERON LAB, R-E-AL8, 325 BROADWAY, BOULDER, CO 80303 USA. NR 43 TC 23 Z9 23 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 30 PY 1992 VL 97 IS D8 BP 7971 EP 7978 PG 8 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA HY079 UT WOS:A1992HY07900011 ER PT J AU WILSON, JC STOLZENBURG, MR CLARK, WE LOEWENSTEIN, M FERRY, GV CHAN, KR KELLY, KK AF WILSON, JC STOLZENBURG, MR CLARK, WE LOEWENSTEIN, M FERRY, GV CHAN, KR KELLY, KK TI STRATOSPHERIC SULFATE AEROSOL IN AND NEAR THE NORTHERN-HEMISPHERE POLAR VORTEX - THE MORPHOLOGY OF THE SULFATE LAYER, MULTIMODAL SIZE DISTRIBUTIONS, AND THE EFFECT OF DENITRIFICATION SO JOURNAL OF GEOPHYSICAL RESEARCH-ATMOSPHERES LA English DT Article ID CONDENSATION NUCLEI; EL-CHICHON; ANTARCTIC STRATOSPHERE; PARTICLE FORMATION; ACID CONDENSATION; CLOUD FORMATION; NITRIC-ACID; OZONE; TEMPERATURE; EXPEDITION AB Measurements were made of stratospheric sulfate aerosols using a passive cavity aerosol spectrometer and a condensation nucleus counter on a NASA ER-2 aircraft in the Airborne Arctic Stratospheric Experiment of 1989. The problems of representative and accurate sampling and particle evaporation were explicitly addressed in the design of the inlets and reduction of the data. The measurements suggest that the sulfate aerosol is bimodal in the polar vortex above the mass mixing ratio maximum in the sulfate layer. It appears that a nuclei mode of small, newly formed particles exists in this region. A stronger case is made for a nuclei mode in the upper few kilometers of the troposphere and in the lower few kilometers of the stratosphere. This mode is probably a global phenomenon occurring in all seasons. Comparison of denitrified and nondenitrified air suggests that denitrification removes some of the larger sulfate particles. C1 AEROSOL DYNAM INC, BERKELEY, CA USA. NASA, AMES RES CTR, MOFFETT FIELD, CA 94035 USA. NOAA, AERON LAB, BOULDER, CO 80303 USA. CALIF POLYTECH STATE UNIV SAN LUIS OBISPO, DEPT MECH ENGN, SAN LUIS OBISPO, CA 93407 USA. RP WILSON, JC (reprint author), UNIV DENVER, DEPT ENGN, DENVER, CO 80202 USA. NR 49 TC 33 Z9 33 U1 0 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 30 PY 1992 VL 97 IS D8 BP 7997 EP 8013 PG 17 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA HY079 UT WOS:A1992HY07900013 ER PT J AU HOVINGH, WJ PARSON, R AF HOVINGH, WJ PARSON, R TI WAVE PACKET DYNAMICS OF INTERNAL ROTATIONAL PREDISSOCIATION IN NEHF AND NEDF SO JOURNAL OF PHYSICAL CHEMISTRY LA English DT Article ID VANDERWAALS MOLECULES; SCHRODINGER-EQUATION; QUANTUM DYNAMICS; SCATTERING; SYSTEMS; SPECTROSCOPY; DISSOCIATION; PROPAGATION; MODEL AB We investigate the process of internal rotational predissociation in the NeHF and NeDF van der Waals complexes using time-dependent quantum mechanical calculations. The computations are performed in three degrees of freedom and for arbitrary values of the total angular momentum; they use a combination of the Fourier wave packet propagation method in the dissociative coordinate with a body-fixed basis set expansion in the intramolecular angular coordinates. Calculated values of the predissociation lifetimes of several states of these complexes are found to be in excellent agreement with the results of time-independent quantum calculations. Product distributions are easily extracted from the evolving wave packets. The fragmentation mechanisms of several metastable states are further explored by examination of the time-evolving probability distribution. C1 UNIV COLORADO, DEPT CHEM & BIOCHEM, BOULDER, CO 80309 USA. UNIV COLORADO, NATL INST STAND & TECHNOL, JOINT INST LAB ASTROPHYS, BOULDER, CO 80302 USA. NR 34 TC 6 Z9 6 U1 0 U2 0 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 0022-3654 J9 J PHYS CHEM-US JI J. Phys. Chem. PD MAY 28 PY 1992 VL 96 IS 11 BP 4200 EP 4209 DI 10.1021/j100190a020 PG 10 WC Chemistry, Physical SC Chemistry GA HX268 UT WOS:A1992HX26800020 ER PT J AU FAHR, A LAUFER, AH AF FAHR, A LAUFER, AH TI THE 1,1-ELIMINATION OF HCN AND FORMATION OF TRIPLET VINYLIDENE FROM THE PHOTOLYSIS OF ACRYLONITRILE SO JOURNAL OF PHYSICAL CHEMISTRY LA English DT Article ID PHOTOELECTRON-SPECTROSCOPY; ACETYLENE; H2CC(3B2); RADICALS AB The single-photon photodissociation of acrylonitrile-1-d has been investigated by flash photolysis and kinetic absorption spectroscopy in the vacuum-ultraviolet region. Both electronically excited triplet vinylidene and DCN were observed. The result provides further evidence that a "vinylidene" type structure with an extended lifetime exists. Alternative primary processes were considered, particularly those involving vinyl radical or molecular acetylene formation, but they were not observed. C1 US DOE,OFF BASIC ENERGY SCI,DIV CHEM SCI,WASHINGTON,DC 20585. RP FAHR, A (reprint author), NATL INST STAND & TECHNOL,DIV CHEM KINET,GAITHERSBURG,MD 20899, USA. NR 20 TC 18 Z9 18 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 28 PY 1992 VL 96 IS 11 BP 4217 EP 4219 DI 10.1021/j100190a022 PG 3 WC Chemistry, Physical SC Chemistry GA HX268 UT WOS:A1992HX26800022 ER PT J AU HUTSON, JM AF HUTSON, JM TI VIBRATIONAL DEPENDENCE OF THE ANISOTROPIC INTERMOLECULAR POTENTIAL OF AR-HCL SO JOURNAL OF PHYSICAL CHEMISTRY LA English DT Article ID INFRARED-LASER SPECTROSCOPY; SIGMA-BENDING VIBRATION; DIATOM VANDERWAALS MOLECULES; DIPOLE OSCILLATOR-STRENGTHS; ENERGY SURFACE; SUPERSONIC JET; STARK SPECTROSCOPY; ROTATIONAL SPECTRA; DAMPING FUNCTIONS; CROSS-SECTIONS AB A new intermolecular potential for Ar-HCl is obtained by fitting to results from high-resolution microwave, far-infrared, and infrared spectroscopy. The new potential is substantially more accurate than any previous Ar-HCl potential and is the first to include the dependence of the potential on the HCl monomer vibration: it is a function of the diatom mass-reduced vibrational quantum number-eta = (nu + 1/2)/mu-HX 1/2 as well as the intermolecular distance R and angle-theta. The functional form used has 19 adjustable parameters, which are determined from the spectroscopic data. The resulting potential, designated H6(4,3,0), reproduces all the available spectroscopic data for levels of Ar-HCl and Ar-DCl correlating with HCl-nu = 0 and 1 and DCl-nu = 0 and 1. The H6(4,3,0) potential is qualitatively similar to previous potentials, with a linear Ar-H-Cl equilibrium geometry and a secondary minimum at the linear Ar-Cl-H geometry. Compared to the H6(3) potential of Hutson [J. Chem. Phys. 1988, 89, 4550], obtained from far-infrared spectra of Ar-HCl, the H6(4,3,0) potential has a slightly larger barrier to internal rotation of HCl and is significantly deeper around the Ar-Cl-H geometry. The anisotropy of the repulsive wall is also somewhat stronger for the H6(4,3,0) potential. The absolute well depth increases by 3.0 cm-1 between HCl-nu = 0 and 1. The vibrationally-averaged induction energy is calculated to be 1.1 cm-1 greater for nu = 1 than for nu = 0 and is responsible for a substantial part of the observed red shift in the complex. Predictions of additional spectroscopic properties that would test the new potential are given. The trends in intermolecular potentials for the series Ar-HF, Ar-HCl, and Ar-HBr are discussed. C1 UNIV DURHAM,DEPT CHEM,DURHAM DH1 3LE,ENGLAND. RP HUTSON, JM (reprint author), UNIV COLORADO,NATL INST STAND & TECHNOL,JOINT INST LAB ASTROPHYS,BOULDER,CO 80302, USA. RI Hutson, Jeremy/F-4748-2012 OI Hutson, Jeremy/0000-0002-4344-6622 NR 91 TC 192 Z9 192 U1 5 U2 11 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 28 PY 1992 VL 96 IS 11 BP 4237 EP 4247 DI 10.1021/j100190a026 PG 11 WC Chemistry, Physical SC Chemistry GA HX268 UT WOS:A1992HX26800026 ER PT J AU IRIKURA, KK JOHNSON, RD HUDGENS, JW AF IRIKURA, KK JOHNSON, RD HUDGENS, JW TI ELECTRONIC-SPECTRUM OF THE SICL3 RADICAL SO JOURNAL OF PHYSICAL CHEMISTRY LA English DT Article ID MULTIPHOTON IONIZATION SPECTROSCOPY; RESONANCE; SILICON; THERMOCHEMISTRY; MECHANISM; SIH3 AB Between 330 and 400 nm the 2 + 1 REMPI spectrum of SiCl3 exhibits two overlapping vibrational progressions composed of > 30 members and one vibrational progression composed of five members. These band systems, labeled F approximately, G approximately, and H approximately, are tentatively assigned to three distinct Rydberg states that reside between 50 100 and 59 600 cm-1. The vibrational progressions have an average spacing of omega(2) = 262 cm-1 and are assigned to the nu(2) umbrella modes of the Rydberg states. Electronic origins are not observed. Ab initio calculations on SiCl3 and SiCl3+ yield geometries and harmonic vibrational frequencies consistent with the spectroscopic assignments and provide the adiabatic ionization potential, IP(a) = 7.93 +/- 0.05 eV. In combination with a recent experimental value for DELTA-H(f)(SiCl3+), this leads to DELTA-H(f)(SiCl3) = -353 +/- 12 kJ/mol. C1 NATL INST STAND & TECHNOL, DIV CHEM KINET & THERMODYNAM, GAITHERSBURG, MD 20899 USA. RI Irikura, Karl/A-4266-2009 OI Irikura, Karl/0000-0001-7515-6761 NR 33 TC 9 Z9 9 U1 1 U2 2 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 0022-3654 J9 J PHYS CHEM-US JI J. Phys. Chem. PD MAY 28 PY 1992 VL 96 IS 11 BP 4306 EP 4310 DI 10.1021/j100190a038 PG 5 WC Chemistry, Physical SC Chemistry GA HX268 UT WOS:A1992HX26800038 ER PT J AU GULDI, DM HAMBRIGHT, P LEXA, D NETA, P SAVEANT, JM AF GULDI, DM HAMBRIGHT, P LEXA, D NETA, P SAVEANT, JM TI ONE-ELECTRON REDUCTION OF CHROMIUM(III) PORPHYRINS - FORMATION OF CHROMIUM(II) PORPHYRINS OR CHROMIUM(III) PORPHYRIN PI-RADICAL ANIONS SO JOURNAL OF PHYSICAL CHEMISTRY LA English DT Article ID 2-ELECTRON REDUCTION; AQUEOUS-SOLUTIONS; METALLOPORPHYRINS; ELECTROCHEMISTRY; COMPLEXES; LIGAND; REDOX; METAL; PYRIDYLPORPHYRINS; KINETICS AB One-electron reduction of chromium(III) porphyrins has been studied by radiolytic and electrochemical methods with several porphyrin ligands in various solvents. The absorption spectra of the first reduction products were monitored by pulse radiolysis within microseconds after the pulse. Two types of differential spectra were observed; intense broad absorptions at 600-800 nm ascribed to the pi-radical anions or weaker sharp absorption at various wavelengths due to chromium(II) porphyrins. Cr(III)TSPP(L1L2) [chromium(III) tetrakis(4-sulfonatophenyl)porphyrin with two axial ligands L1 and L2] was reduced to the pi-radical anion in water, alcohols, and N,N-dimethylformamide (DMF), where L1 and L2 are H2O, OH-, ROH, RO-, or DMF. Cr(III)TPP(Cl)L (tetraphenylporphyrin) and Cr(III)TMP(Cl)L (tetramesitylporphyrin), on the other hand, were reduced on the metal in neutral alcohol (L = ROH) but gave the pi-radical anions when either the Cl- was exchanged with OH- (in the presence of KOH) or L was replaced with pyridine, DMF, or dimethyl sulfoxide (DMSO). Cr(III)OEP(Cl)L (octaethylporphyrin) in alcohol and Cr(III)MSP(OH)L (mesoporphyrin-IX) in aqueous alcohol were reduced to Cr(II)P even in the presence of base. With added pyridine, however, reduction took place on the ligand to form the Cr(III)P.- species. Cyclic voltammetry and thin layer spectroelectrochemistry experiments were carried out to determine the redox potential and to confirm the above assignments. In conclusion, all chromium porphyrins studied are reduced on the metal center when this bears axial ligands that are weak electron donors, but stronger axial ligands on the Cr center direct the reduction toward the porphyrin pi-system. C1 NATL INST STAND & TECHNOL,DIV CHEM KINET & THERMODYNAM,GAITHERSBURG,MD 20899. HOWARD UNIV,DEPT CHEM,WASHINGTON,DC 20059. UNIV PARIS 07,ELECTROCHIM LAB,F-75251 PARIS 05,FRANCE. RI Guldi, Dirk/G-1422-2015 NR 34 TC 27 Z9 27 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 28 PY 1992 VL 96 IS 11 BP 4459 EP 4466 DI 10.1021/j100190a062 PG 8 WC Chemistry, Physical SC Chemistry GA HX268 UT WOS:A1992HX26800062 ER PT J AU SEAKINS, PW LEONE, SR AF SEAKINS, PW LEONE, SR TI A LASER FLASH-PHOTOLYSIS TIME-RESOLVED FTIR EMISSION STUDY OF A NEW CHANNEL IN THE REACTION OF CH3 + O - PRODUCTION OF CO(UPSILON) SO JOURNAL OF PHYSICAL CHEMISTRY LA English DT Article ID GAS-PHASE DECOMPOSITION; METHYL RADICALS; FORMALDEHYDE PHOTOCHEMISTRY; ATMOSPHERIC CHEMISTRY; 193 NM; KINETICS; CO; COMBUSTION; ACETONE; PHOTOFRAGMENTATION AB The reaction of CH3 radicals and O atoms is studied using laser flash photolysis/time-resolved Fourier transform infrared emission spectroscopy. In addition to observing formaldehyde vibrational CH emission, molecular CO vibrational emission is also detected. Experiments are performed to confirm that CO is a primary product from the title reaction. The observed CO vibrational distribution (v = 1-8) can be fit with a vibrational temperature of 12 700 +/- 1400 K, and the fraction of the reaction exothermicity released into CO vibration is 0.22. The branching fraction to CO is estimated to be 0.40 +/- 0.10. C1 UNIV COLORADO,NATL INST STAND & TECHNOL,JOINT INST LAB ASTROPHYS,BOULDER,CO 80302. UNIV COLORADO,DEPT CHEM & BIOCHEM,BOULDER,CO 80309. NR 43 TC 58 Z9 58 U1 0 U2 6 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 SN 0022-3654 J9 J PHYS CHEM-US JI J. Phys. Chem. PD MAY 28 PY 1992 VL 96 IS 11 BP 4478 EP 4485 DI 10.1021/j100190a065 PG 8 WC Chemistry, Physical SC Chemistry GA HX268 UT WOS:A1992HX26800065 ER PT J AU ORR, JC AF ORR, JC TI CARBON-DIOXIDE DISPOSAL - THE DEEP-6 FIX AGAIN SO NATURE LA English DT Editorial Material RP ORR, JC (reprint author), PRINCETON UNIV,ATMOSPHER & OCEAN SCI PROGRAM,POB CN710,SAYRE HALL,PRINCETON,NJ 08544, USA. RI Orr, James/C-5221-2009; OI Orr, James/0000-0002-8707-7080 NR 6 TC 1 Z9 1 U1 0 U2 0 PU MACMILLAN MAGAZINES LTD PI LONDON PA PORTERS SOUTH, 4 CRINAN ST, LONDON, ENGLAND N1 9XW SN 0028-0836 J9 NATURE JI Nature PD MAY 28 PY 1992 VL 357 IS 6376 BP 283 EP 284 DI 10.1038/357283a0 PG 2 WC Multidisciplinary Sciences SC Science & Technology - Other Topics GA HW132 UT WOS:A1992HW13200024 ER PT J AU HAMMOUDA, B NAKATANI, AI WALDOW, DA HAN, CC AF HAMMOUDA, B NAKATANI, AI WALDOW, DA HAN, CC TI SMALL-ANGLE NEUTRON-SCATTERING FROM DEUTERATED POLYSTYRENE IN DIOCTYL PHTHALATE SOLUTION UNDER SHEAR SO MACROMOLECULES LA English DT Article ID POLYMER-SOLUTIONS; POLYVINYL METHYL-ETHER); BLENDS; FLUCTUATIONS; MISCIBILITY; APPARATUS; VISCOSITY; DYNAMICS; FLOW AB Small-angle neutron scattering measurements were taken from high molecular weight (1.95 x 10(6)) deuterated polystyrene in dioctyl phthalate solution at low concentration (3% weight fraction) under steady shear with rates ranging from the quiescent condition (0 s-1) to 1100 s-1 at room temperature (22-degrees-C). The scattered intensity increased drastically beyond a characteristic shear rate (gamma(c) = 57 s-1) similar to the increase following a temperature drop from the one-phase region (ambient temperature) to the two-phase region in this upper critical solution temperature system. The cloud point is estimated to be a few degrees lower than 14-degrees-C which is the cloud point for protonated polystyrene in dioctyl phthalate at this molecular weight and concentration. On the basis of this analogy, the random-phase approximation (RPA) approach (the Zimm inverse scattering formula) was used along with a swollen radius of gyration in the Debye function to analyze the data and extract a statistical segment length b and a polymer-solvent interaction parameter chi(ps). The segment length was seen to increase slightly, indicating a slight increase in chain volume beyond gamma(c), while the interaction parameter showed a dramatic increase up to the 'spinodal" value gamma(s) = 280 s-1 where the RPA breaks down, therefore giving nonreliable values. This data treatment method has no justification on physical grounds: it is merely a way to quantify our observations since specific models that could explain our data are not available at this time. C1 NBS,DIV POLYMERS,GAITHERSBURG,MD 20899. RP HAMMOUDA, B (reprint author), NBS,DIV REACTOR RADIAT,MAT SCI & ENGN LAB,BLDG 235,E 151,GAITHERSBURG,MD 20899, USA. OI Waldow, Dean/0000-0002-0588-4760 NR 25 TC 21 Z9 21 U1 0 U2 5 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 SN 0024-9297 J9 MACROMOLECULES JI Macromolecules PD MAY 25 PY 1992 VL 25 IS 11 BP 2903 EP 2906 DI 10.1021/ma00037a018 PG 4 WC Polymer Science SC Polymer Science GA HX033 UT WOS:A1992HX03300018 ER PT J AU BUHR, MP TRAINER, M PARRISH, DD SIEVERS, RE FEHSENFELD, FC AF BUHR, MP TRAINER, M PARRISH, DD SIEVERS, RE FEHSENFELD, FC TI ASSESSMENT OF POLLUTANT EMISSION INVENTORIES BY PRINCIPAL COMPONENT ANALYSIS OF AMBIENT AIR MEASUREMENTS SO GEOPHYSICAL RESEARCH LETTERS LA English DT Article AB The emission ratios of [CO]/[NOX] and [SO2]/[NOX] in point and area type sources in the northeastern United States are estimated through a combination of principal component and bivariate regression analyses of concurrent measurements of [CO], [SO2], [NOX], and [NOY] made at a rural Pennsylvania field site during the summer of 1988. Principal component analysis is used to identify time periods when the covariation of [NOY] with either [CO] or [SO2] indicates that the air mass was dominated by emissions from either area or point type sources, respectively. A regression analysis is used to extrapolate the observed pollutant ratios to the emission ratios. The resulting emission ratios compare reasonably well with emission ratios derived from the 1985 NAPAP (National Acid Precipitation Assessment Program) emissions inventory, although this analysis indicates that the NAPAP inventory may underestimate the [CO]/[NOX] emission ratio for area sources by a factor of 1.0 to 2.2 (95% confidence limits). C1 UNIV COLORADO,INST RES ENVIRONM SCI,BOULDER,CO 80309. RP BUHR, MP (reprint author), NOAA,AERON LAB,R-E-AL7,325 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 14 TC 43 Z9 44 U1 0 U2 3 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 MAY 22 PY 1992 VL 19 IS 10 BP 1009 EP 1012 DI 10.1029/92GL01020 PG 4 WC Geosciences, Multidisciplinary SC Geology GA HW344 UT WOS:A1992HW34400014 ER PT J AU CURRIER, PE AVERY, SK BALSLEY, BB GAGE, KS ECKLUND, WL AF CURRIER, PE AVERY, SK BALSLEY, BB GAGE, KS ECKLUND, WL TI COMBINED USE OF 50 MHZ AND 915 MHZ WIND PROFILERS IN THE ESTIMATION OF RAINDROP SIZE DISTRIBUTIONS SO GEOPHYSICAL RESEARCH LETTERS LA English DT Article ID VELOCITY; RADARS; CLOUD; DROPS AB To estimate raindrop size distributions aloft, we fit a theoretical Doppler spectrum of a model drop size distribution to observed Doppler power spectra measured by a 915 MHz profiler, while using concurrent information supplied by a 50 MHz profiler to correct for vertical winds. While several assumptions have been made in deriving the theoretical Doppler spectrum, model derived rainfall rates compare favorably with locally measured rainfall rates obtained from rain gauge estimates. C1 UNIV COLORADO,NOAA,COOPERAT INST RES ENVIRONM SCI,BOULDER,CO 80309. UNIV COLORADO,DEPT ELECT & COMP ENGN,BOULDER,CO 80309. NOAA,ACRON LAB,BOULDER,CO 80303. RP CURRIER, PE (reprint author), ETS DEGREANE,F-83050 TOULON,FRANCE. NR 23 TC 49 Z9 51 U1 0 U2 3 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 MAY 22 PY 1992 VL 19 IS 10 BP 1017 EP 1020 DI 10.1029/92GL00191 PG 4 WC Geosciences, Multidisciplinary SC Geology GA HW344 UT WOS:A1992HW34400016 ER PT J AU MOUNT, GH EISELE, FL AF MOUNT, GH EISELE, FL TI AN INTERCOMPARISON OF TROPOSPHERIC OH MEASUREMENTS AT FRITZ-PEAK-OBSERVATORY, COLORADO SO SCIENCE LA English DT Article ID LASER-INDUCED FLUORESCENCE; MODEL AB The hydroxyl radical (OH) controls the lifetimes and therefore the concentrations of many important chemical species in Earth's lower atmosphere including several greenhouse and ozone-depleting species. Two completely different measurement techniques were used in an informal intercomparison to determine tropospheric OH concentrations at Fritz Peak Observatory, Colorado, from 15 July to 24 August 1991. One technique determined OH concentrations by chemical analysis; the other used spectroscopic absorption on a long path. The intercomparison showed that ambient OH concentrations can now be measured with sufficient sensitivity to provide a test for photochemical models, with the derived OH concentrations agreeing well under both polluted and clean atmospheric conditions. Concentrations of OH on all days were significantly lower than model predictions, perhaps indicating the presence of an unknown scavenger. The change in OH concentration from early morning to noon on a clear day was found to be only a factor of 2. C1 GEORGIA INST TECHNOL,RES INST,PHYS SCI LAB,ATLANTA,GA 30332. RP MOUNT, GH (reprint author), NOAA,ENVIRONM RES LABS,AERON LAB,325 BROADWAY,BOULDER,CO 80303, USA. NR 15 TC 71 Z9 73 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 22 PY 1992 VL 256 IS 5060 BP 1187 EP 1190 DI 10.1126/science.256.5060.1187 PG 4 WC Multidisciplinary Sciences SC Science & Technology - Other Topics GA HV192 UT WOS:A1992HV19200030 PM 17795214 ER PT J AU DEILAMIAN, K GILLASPY, JD KELLEHER, DE AF DEILAMIAN, K GILLASPY, JD KELLEHER, DE TI STRAY-LIGHT SUPPRESSION WITH HIGH-COLLECTION EFFICIENCY IN LASER LIGHT-SCATTERING EXPERIMENTS SO APPLIED OPTICS LA English DT Article DE STRAY-LIGHT REJECTION; LIGHT COLLECTION; LIGHT SCATTERING; PHOTON-BURST SPECTROSCOPY; FLUORESCENCE ID SPECTROSCOPY; ATOMS AB We describe an optical system that we constructed to collect a large fraction of fluorescent light emitted isotropically from a cylindrical interaction region. While maintaining an overall detection efficiency of 9%, the system rejects, by more than 12 orders of magnitude, incident laser light along a single axis that intersects the interaction region. Such a system is useful for a wide variety of light-scattering experiments in which high-collection efficiency is desirable, but in which light from an incident laser beam must be rejected without resorting to spectral filters. C1 UNIV WISCONSIN,DEPT PHYS,MADISON,WI 53706. NAT INST STAND & TECHNOL,GAITHERSBURG,MD 20899. NR 20 TC 3 Z9 3 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 MAY 20 PY 1992 VL 31 IS 15 BP 2820 EP 2824 PG 5 WC Optics SC Optics GA HU712 UT WOS:A1992HU71200026 PM 20725216 ER PT J AU RYE, BJ FREHLICH, RG AF RYE, BJ FREHLICH, RG TI OPTIMAL TRUNCATION AND OPTICAL-EFFICIENCY OF AN APERTURED COHERENT LIDAR FOCUSED ON AN INCOHERENT BACKSCATTER TARGET SO APPLIED OPTICS LA English DT Article ID SIGNAL-TO-NOISE; HETERODYNE-DETECTION; BEAM; RETURNS AB Two earlier computations of the optimal truncation of Gaussian beams for a simple, focused, coherent lidar that used an incoherent backscatter target with identical circular transmitter and receiver apertures differ because they refer to different receiver geometries. The definitions of heterodyne and system-antenna efficiencies are reviewed in light of the discrepancy and are used to compare the optical performance of systems with apertures illuminated by beam profiles that are not Gaussian. The heterodyne efficiency is less than 0.5 for all cases considered here. RP RYE, BJ (reprint author), UNIV COLORADO,NOAA,COOPERAT INST RES ENVIRONM SCI,BOULDER,CO 80309, USA. NR 22 TC 31 Z9 32 U1 0 U2 1 PU OPTICAL SOC AMER PI WASHINGTON PA 2010 MASSACHUSETTS AVE NW, WASHINGTON, DC 20036 SN 0003-6935 J9 APPL OPTICS JI Appl. Optics PD MAY 20 PY 1992 VL 31 IS 15 BP 2891 EP 2899 PG 9 WC Optics SC Optics GA HU712 UT WOS:A1992HU71200033 PM 20725223 ER PT J AU HERAS, AM SANAHUJA, B SMITH, ZK DETMAN, T DRYER, M AF HERAS, AM SANAHUJA, B SMITH, ZK DETMAN, T DRYER, M TI THE INFLUENCE OF THE LARGE-SCALE INTERPLANETARY SHOCK STRUCTURE ON A LOW-ENERGY PARTICLE EVENT SO ASTROPHYSICAL JOURNAL LA English DT Article DE INTERPLANETARY MEDIUM; MHD; SHOCK WAVES; SUN, PARTICLE EMISSION ID PITCH-ANGLE SCATTERING; ION-ACCELERATION; GENERATED DISTURBANCES; TRAVELING SHOCKS; 1600-KEV PROTONS; COSMIC-RAYS; MHD MODEL; UPSTREAM; WAVES; TRANSPORT AB We have developed a numerical model to study the influence of the large-scale shock topology on the associated low-energy (less than 2 MeV) particle event upstream of the shock. It includes particle injection at the solar corona, two-dimensional MHD simulation of the propagation of the shock, modeling of particle propagation through the interplanetary medium, and particle injection at the shock. The model does not attempt to simulate the physical processes of shock particle acceleration, therefore the injection at the shock is represented by a numerical source function in the equation that describes particle propagation. The MHD simulation provides the time when the shock intersects the interplanetary magnetic field line which connects with the spacecraft, the evolution of this connection point over the shock front, and its plasma characteristics as it propagates out into the heliosphere. Considering these results, and by fitting the observed particle flux and anisotropy profiles, the model allows us to determine the parameters which characterize particle propagation and the rate of particle injection at the shock front. Therefore, it is possible to infer the history of the development of the particle event and to analyze the possible relations with the parameters at the point of the shock that is, at each moment, magnetically connected with the spacecraft. The model can be applied to those low-energy particle events that are associated with strong interplanetary shocks and that are characterized by a steady upstream magnetic field and solar wind velocity. Particularly, we have studied the particle event associated with the interplanetary shock observed on 1979 April 24 by ISEE-3 in the energy range 35-1600 keV. The magnetic connection between the shock and the spacecraft is established about 18 hr after the filament disappearance which generated the event. We then infer from the model that the shock is quasi-perpendicular at the intersection point and becomes quasi-parallel when it approaches the spacecraft. The fit to the observations requires that the injection rate at the shock increases with time. It is also necessary to assume the existence of a region of enhanced scattering upstream of the shock, 0.15 AU wide (the minimum allowed by the numerical model). The mean free path derived in that region is one order of magnitude smaller than farther upstream. C1 UNIV BARCELONA,DEPT ASTRON & METEOROL,E-08028 BARCELONA,SPAIN. INST ESTUD CATALANS,ASTROFIS LAB,BARCELONA,SPAIN. NOAA,SPACE ENVIRONM LAB,BOULDER,CO 80303. RP HERAS, AM (reprint author), EUROPEAN SPACE TECHNOL CTR,SPACE SCI DEPT ESA,POB 299,2200 AG NOORDWIJK,NETHERLANDS. RI xue, yansheng/A-9712-2012 NR 63 TC 48 Z9 49 U1 1 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 MAY 20 PY 1992 VL 391 IS 1 BP 359 EP 369 DI 10.1086/171351 PN 1 PG 11 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA HT591 UT WOS:A1992HT59100031 ER PT J AU WILLIAMS, EJ GUENTHER, A FEHSENFELD, FC AF WILLIAMS, EJ GUENTHER, A FEHSENFELD, FC TI AN INVENTORY OF NITRIC-OXIDE EMISSIONS FROM SOILS IN THE UNITED-STATES SO JOURNAL OF GEOPHYSICAL RESEARCH-ATMOSPHERES LA English DT Article ID FIELD-MEASUREMENTS; NITROUS-OXIDE; OZONE PRODUCTION; FOREST; NO; TROPOSPHERE; SAVANNA; SEASON AB A national inventory of soil nitric oxide (NO) emissions with county spatial resolution and monthly time resolution has been developed from empirical relationships that were derived from soil NO emissions data. The empirical relationships used to develop the inventory relate the emission of NO to soil temperature and a factor which is representative of an ecosystem or type of land use. Most of the ecosystem/land use factors were derived from analyses of NO emission data from seven different sites in the United States that are representative of three ecosystems and two agricultural land use types. Other agricultural (crop) land use factors were estimated from the two calculated factors based on differences in fertilization associated with the crops. This soil emission inventory exhibits three general features. First, croplands, especially where corn is grown, appear to be significant sources of NO. This has important implications because agricultural activities tend to be localized to certain regions in the United States (i.e., the Midwest) and are highest during the summer, when photochemistry is also most active. Second, undisturbed areas, such as grasslands, forests, and wetlands, do not appear to contribute substantially to atmospheric NO. Third, extensive areas in the western United States have not been included because soil NO emission data are lacking. C1 UNIV COLORADO, COOPERAT INST RES ENVIRONM SCI, BOULDER, CO 80309 USA. RP WILLIAMS, EJ (reprint author), NOAA, AERONOMY LAB, 325 BROADWAY, BOULDER, CO 80303 USA. RI Williams, Eric/F-1184-2010; Fehsenfeld, Frederick/I-4876-2013; Guenther, Alex/B-1617-2008 OI Guenther, Alex/0000-0001-6283-8288 NR 26 TC 155 Z9 164 U1 2 U2 16 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 1992 VL 97 IS D7 BP 7511 EP 7519 PG 9 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA HV487 UT WOS:A1992HV48700002 ER PT J AU ZHOU, MY LU, NP MILLER, J PARUNGO, FP NAGAMOTO, C YANG, SJ AF ZHOU, MY LU, NP MILLER, J PARUNGO, FP NAGAMOTO, C YANG, SJ TI CHARACTERIZATION OF ATMOSPHERIC AEROSOLS AND OF SUSPENDED PARTICLES IN SEAWATER IN THE WESTERN PACIFIC-OCEAN SO JOURNAL OF GEOPHYSICAL RESEARCH-ATMOSPHERES LA English DT Article ID TROPICAL MARINE ATMOSPHERE; TRACE-ELEMENTS; TEMPORAL VARIABILITY; EQUATORIAL PACIFIC; ENEWETAK-ATOLL; CHEMISTRY; PRECIPITATION; DEPOSITION; TRANSPORT; HALOGENS AB Aerosol samples were collected to study the variabilities of marine aerosols at different times and in different ocean areas. The samples were collected during the first three cruises (December 12, 1985, to February 21, 1986; November 11, 1986, to March 1, 1987; September 27 to November 4, 1987) operated by the cooperative program between the United States and the People's Republic of China. The concentrations of crustal and pollution elements in aerosols were high over the ocean area close to the China coast and decreased very rapidly with increasing distance from land. For the third cruise, in the ocean area northeast of the Philippines, the concentrations of crustal and pollution elements in aerosols were high, especially Fe, whose values reached 3.15 x 10(-5) g m-3. For all three cruises, the mass size distributions of crustal elements and pollution elements in aerosols showed more large particles. The morphology and elemental composition of aerosol particles showed that sea-salt particles may conglomerate with small crustal and pollution particles from land to form large particles (d > 0.3-mu-m) in surface seawater approximately fitted the Junge size distribution. The concentration of suspended particles in surface seawater decreased with increasing distance from land except at the equator, where particle concentrations were high. In addition, results from rain chemistry show that the relative importance between wet deposition and dry deposition varies with trace elements. C1 NOAA, ENVIRONM RES LABS, AIR RESOURCES LAB, BOULDER, CO 80303 USA. CHINESE ACAD SCI, INST HIGH ENERGY PHYS, BEIJING, PEOPLES R CHINA. RP ZHOU, MY (reprint author), NATL RES CTR MARINE ENVIRONM FORECAST, BEIJING, PEOPLES R CHINA. NR 40 TC 20 Z9 24 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 1992 VL 97 IS D7 BP 7553 EP 7567 PG 15 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA HV487 UT WOS:A1992HV48700006 ER PT J AU LANGE, CW FOLDEAKI, M NEVODCHIKOV, VI CHERKASOV, VK ABAKUMOV, GA PIERPONT, CG AF LANGE, CW FOLDEAKI, M NEVODCHIKOV, VI CHERKASOV, VK ABAKUMOV, GA PIERPONT, CG TI PHOTOMECHANICAL PROPERTIES OF RHODIUM(I) SEMIQUINONE COMPLEXES - THE STRUCTURE, SPECTROSCOPY, AND MAGNETISM OF (3,6-DI-TERT-BUTYL-1,2-SEMIQUINONATO)DICARBONYLRHODIUM(I) SO JOURNAL OF THE AMERICAN CHEMICAL SOCIETY LA English DT Article AB Crystals of Rh(CO)2(3,6-DBSQ) [3,6-DBSQ = 3,6-di-tert-butyl-1,2-semiquinone] have been reported to bend reversibly when exposed to light in thc near-IR. Structural characterization on the complex has confirmed the Rh(I)-DBSQ charge distribution for the complex and shown that molecules are stacked in columns in the solid state with a slightly nonlinear oligomeric rhodium core. Magnetic features show marked temperature dependence with both ferromagnetic and antiferromagnetic interactions apparent over the temperature range between 330 and 5 K. Coupling between radical semiquinone ligands is propagated through Rh-Rh interactions along the column. Solution (pentane) UV-vis-NIR spectra recorded over the temperature range from 300 to 150 K show evidence for oligomer formation with spectral changes resulting in a dramatic color change for the solution, from orange-brown at room temperature to dark green at lower temperatures. Strong transitions that appear in the NIR in solution at the lower temperatures also appear in the solid-state spectrum of the complex at room temperature. These properties reflect the strength of interactions between Rh(CO)2(3,6-DBSQ) molecules in the polymeric chain. The low-energy MLCT transition that is characteristic of the oligomeric structure may contribute to the unique photomechanical property of the complex in the solid state. C1 ACAD SCI USSR,INST ORGANOMET CHEM,GORKI,USSR. UNIV COLORADO,DEPT CHEM & BIOCHEM,BOULDER,CO 80209. NATL INST STAND & TECHNOL,DIV MAT RELIABIL,BOULDER,CO 80303. RI Pierpont, Cortlandt/A-8411-2009; Abakumov, Gleb/S-1765-2016 OI Pierpont, Cortlandt/0000-0002-1431-6079; Abakumov, Gleb/0000-0001-9295-9603 NR 11 TC 85 Z9 85 U1 0 U2 6 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 SN 0002-7863 J9 J AM CHEM SOC JI J. Am. Chem. Soc. PD MAY 20 PY 1992 VL 114 IS 11 BP 4220 EP 4222 DI 10.1021/ja00037a027 PG 3 WC Chemistry, Multidisciplinary SC Chemistry GA HV675 UT WOS:A1992HV67500027 ER PT J AU ANDO, S YAMAUCHI, H HATANO, M HEARD, WR AF ANDO, S YAMAUCHI, H HATANO, M HEARD, WR TI COMPARISON OF MUSCLE COMPOSITIONS BETWEEN RED-FLESHED AND WHITE-FLESHED CHINOOK SALMON (ONCORHYNCHUS-TSHAWYTSCHA) SO AQUACULTURE LA English DT Article ID CHUM SALMON; CAROTENOID DEPOSITION; GENETIC-VARIATION; RAINBOW-TROUT; PIGMENTATION; KETA; MIGRATION; OVARY AB Sexually mature chinook salmon were classified as red- and white-fleshed, based on the carotenoid levels of muscle and integument. Chinook salmon with high levels of total carotenoids in either muscle or integument were regarded as red-fleshed, regardless of their muscle color. The salmon with low carotenoid levels of muscle and integument were considered white-fleshed. There were no significant differences in muscle compositions of moisture, protein, and lipid. The changes in "a" value, which expresses the red color of the muscle, were parallel with those of the carotenoid levels, as indicated by a coefficient of correlation of 0.95, while no close correlation (r=0.09) was found between lipid and carotenoid levels of red- and white-fleshed salmon. These results suggested that changes of muscle composition occurring during spawning migration of chinook salmon are related to their physiological state, but not their muscle color type. C1 HOKKAIDO UNIV,FAC FISHERIES,HAKODATE,HOKKAIDO 041,JAPAN. ALASKA FISHERIES SCI CTR,AUKE BAY LAB,AUKE BAY,AK 99821. RP ANDO, S (reprint author), KAGOSHIMA UNIV,FAC FISHERIES,FOOD CHEM LAB,4-50-20 SHIMOARATA,KAGOSHIMA 890,JAPAN. NR 23 TC 4 Z9 5 U1 4 U2 6 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0044-8486 J9 AQUACULTURE JI Aquaculture PD MAY 15 PY 1992 VL 103 IS 3-4 BP 359 EP 365 DI 10.1016/0044-8486(92)90178-N PG 7 WC Fisheries; Marine & Freshwater Biology SC Fisheries; Marine & Freshwater Biology GA HX726 UT WOS:A1992HX72600013 ER PT J AU FARFANTE, IP ROBERTSON, L AF FARFANTE, IP ROBERTSON, L TI HERMAPHRODITISM IN THE PENAEID SHRIMP PENAEUS-VANNAMEI (CRUSTACEA, DECAPODA, PENAEIDAE) SO AQUACULTURE LA English DT Article AB Two hermaphroditic Penaeus vannamei were found among a group of F4 broodstock cultured at shrimp farm in Venezuela. These shrimp described herein are the first reported penaeoids known to possess a thelycum, petasma, appendix masculina, ovaries, testes, and the genital apertures of both sexes. The male and female gonopores are normal; the thelyca are similar to that of normal females the petasmata and appendices masculinae are smaller than normal and with atypical shape; the ovaries and testes are much reduced, but histological preparations reveal that the tissues are typical of normal shrimp. No evidence of parasitism was found in the specimens, nor is any other factor apparent that may have induced these abnormal sexual features. Since the specimens were found at a commercial shrimp farm, perhaps this occurrence of hermaphroditism is in some way linked to condition(s) encountered during the culture of penaeid shrimp in captivity. C1 TEXAS AGR EXPTL STN,SHRIMP MARICULTURE PROJECT,CORPUS CHRISTI,TX 78418. RP FARFANTE, IP (reprint author), NATL MUSEUM NAT HIST,NATL SYSTEMAT LAB,NATL MARINE FISHERIES SERV,WASHINGTON,DC 20560, USA. NR 16 TC 2 Z9 2 U1 0 U2 1 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0044-8486 J9 AQUACULTURE JI Aquaculture PD MAY 15 PY 1992 VL 103 IS 3-4 BP 367 EP 376 DI 10.1016/0044-8486(92)90179-O PG 10 WC Fisheries; Marine & Freshwater Biology SC Fisheries; Marine & Freshwater Biology GA HX726 UT WOS:A1992HX72600014 ER PT J AU PARSON, R AF PARSON, R TI ON THE CONSTRUCTION AND INTERPRETATION OF CORIOLIS-ADAPTED NORMAL-MODES SO CHEMICAL PHYSICS LA English DT Article ID VIBRATIONAL-ENERGY TRANSFER; TRIPLY-DEGENERATE FUNDAMENTALS; TETRAHEDRAL XY4 MOLECULES; POLYATOMIC-MOLECULES; COORDINATE FORMULATION; D2CO-D2CO COLLISIONS; ROTATION ENERGIES; FORMALDEHYDE; PERSPECTIVE; PARTICLES AB Coriolis-adapted normal modes have proved to be a useful device for unravelling the vibration-rotation interaction between nearly degenerate vibrations in near-symmetric top molecules. In this paper the generalization to more than two modes coupled through rotation about more than one body-fixed axis is developed. It is shown that these generalized Coriolis-adapted normal modes are not truly independent (their Poisson brackets do not vanish, and by analogy the corresponding quantum-mechanical operators do not commute); this appears to be a result of the fundamentally greater complexity of three-dimensional rotation compared to rotation in a plane. The procedure is applied to an exactly solvable model, Teller's Hamiltonian for a triply degenerate harmonic vibration in a spherical top molecule, and it is seen that two vibrational actions are given correctly but a third is not. The analysis helps to clarify the physical significance of this new approach to vibration-rotation interactions. C1 UNIV COLORADO,JOINT INST LAB ASTROPHYS,BOULDER,CO 80309. NATL INST STAND & TECHNOL,BOULDER,CO 80309. RP PARSON, R (reprint author), UNIV COLORADO,DEPT CHEM & BIOCHEM,BOULDER,CO 80309, USA. NR 66 TC 3 Z9 3 U1 2 U2 3 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0301-0104 J9 CHEM PHYS JI Chem. Phys. PD MAY 15 PY 1992 VL 162 IS 2-3 BP 235 EP 247 DI 10.1016/0301-0104(92)85001-B PG 13 WC Chemistry, Physical; Physics, Atomic, Molecular & Chemical SC Chemistry; Physics GA HV161 UT WOS:A1992HV16100001 ER PT J AU DOYLE, JR DOUGHTY, DA GALLAGHER, A AF DOYLE, JR DOUGHTY, DA GALLAGHER, A TI PLASMA CHEMISTRY IN SILANE GERMANE AND DISILANE GERMANE MIXTURES SO JOURNAL OF APPLIED PHYSICS LA English DT Article ID A-SI-H; RF GLOW-DISCHARGES; DEPOSITION RATES; ION-BOMBARDMENT; ALLOYS; FILM; PHOTOIONIZATION; DISSOCIATION; RADICALS; SYSTEMS AB A detailed kinetic study of silane-germane glow discharges is presented. Stable gas decomposition and production rates have been measured using mass spectrometry and a kinetic model for the plasma chemistry is developed. It is found that germane depletes about four times faster than silane, nearly independently of their relative fractions. Germane is found to be much more reactive than silane with silylene, germalyn, and atomic hydrogen, and the silylene-germane reaction leads in large part to film rather than stable gases. The spatial characteristics of the discharge are studied using optical emission and fiber deposition profiles. From these it is deduced that the present, low-power discharge operates in a "hybrid" alpha-gamma regime, and that ion effects are important near the electrodes. C1 NATL INST STANDARDS & TECHNOL,JOINT INST LAB ASTROPHYS,BOULDER,CO 80309. UNIV COLORADO,BOULDER,CO 80309. NR 36 TC 26 Z9 26 U1 0 U2 6 PU AMER INST PHYSICS PI WOODBURY PA CIRCULATION FULFILLMENT DIV, 500 SUNNYSIDE BLVD, WOODBURY, NY 11797-2999 SN 0021-8979 J9 J APPL PHYS JI J. Appl. Phys. PD MAY 15 PY 1992 VL 71 IS 10 BP 4727 EP 4738 DI 10.1063/1.350663 PG 12 WC Physics, Applied SC Physics GA HV471 UT WOS:A1992HV47100010 ER PT J AU DOYLE, JR DOUGHTY, DA GALLAGHER, A AF DOYLE, JR DOUGHTY, DA GALLAGHER, A TI PLASMA CHEMISTRY IN DISILANE DISCHARGES SO JOURNAL OF APPLIED PHYSICS LA English DT Article ID HYDROGENATED AMORPHOUS-SILICON; FILM-PRODUCING RADICALS; ABSOLUTE RATE CONSTANTS; RF GLOW-DISCHARGES; ELECTRON-IMPACT; 147-NM PHOTOLYSIS; CROSS-SECTIONS; DC DISCHARGES; SILANE PLASMA; DEPOSITION AB We have measured the initial silane and polysilane product yields from disilane decomposition in rf and dc discharges, at 25 and 250-degrees-C and 20 Pa (0.15 Torr) pressure as typically used for a-Si:H film deposition. From analyses of these yields we conclude that the initial Si2H6 fragmentation pattern is SiH3 + SiH2 + H (91 +/- 9%) and H3SiSiH + 2H (9 +/- 9%), that the primary product of the H + Si2H6 reaction is SiH4 + SiH3, and that SiH3 is the dominant radical causing film growth. We have measured a radical-surface reaction probability of 0.34 +/- 0.03, very similar to that observed for SiH3 in SiH4 discharges. We report a spatial distribution of emission indicative of a gamma-regime discharge. From deposition on glass fibers strung between the electrodes, we find that highly strained a-Si:H film is produced everywhere except on or near the electrodes, suggesting that energetic ion impact is necessary to yield useful films in disilane discharges. C1 NATL INST STANDARDS & TECHNOL,JOINT INST LAB ASTROPHYS,BOULDER,CO 80309. UNIV COLORADO,BOULDER,CO 80309. NR 32 TC 35 Z9 35 U1 0 U2 4 PU AMER INST PHYSICS PI WOODBURY PA CIRCULATION FULFILLMENT DIV, 500 SUNNYSIDE BLVD, WOODBURY, NY 11797-2999 SN 0021-8979 J9 J APPL PHYS JI J. Appl. Phys. PD MAY 15 PY 1992 VL 71 IS 10 BP 4771 EP 4780 DI 10.1063/1.350669 PG 10 WC Physics, Applied SC Physics GA HV471 UT WOS:A1992HV47100016 ER PT J AU FRASER, GT SUENRAM, RD AF FRASER, GT SUENRAM, RD TI PERTURBATIONS IN THE INFRARED-SPECTRUM OF THE NH3 UMBRELLA MODE OF HOH-NH3 SO JOURNAL OF CHEMICAL PHYSICS LA English DT Article ID RESONANCE OPTOTHERMAL SPECTROSCOPY; TRANSFORM MICROWAVE SPECTROSCOPY; AMMONIA WATER COMPLEX; ROTATIONAL SPECTRUM; FREQUENCIES; VIBRATION; CLUSTERS; VAPOR; BAND AB A tunable microwave-sideband CO2 laser has been used with a molecular-beam electric-resonance optothermal spectrometer to observe the infrared spectrum of the NH3 umbrella fundamental vibration (v5 in C(s)) of HOH-NH3 at a resolution of approximately 3 MHz. Ground- and excited-state assignments were verified and extended using microwave-infrared double-resonance spectroscopy, with microwave transitions observed in both the ground and the excited states. The spectrum exhibits numerous perturbations, as evidenced by the observation of a minimum of 13 subbands originating from the (K,m) = (0,0) ground NH, internal-rotor state and the (K,m) = (+/- 1, +/- 1) first excited NH3 internal-rotor state. For an unperturbed spectrum, only four such subbands are expected, two for the symmetric H2O tunneling state and two for the antisymmetric H2O tunneling state. The rotational progressions within the excited states are poorly fit to polynomial series in J(J + 1), in contrast to the ground-state progressions which are well characterized by such series. The B rotational constants in the excited states are smaller than in the ground state, indicating an extension of the hydrogen-bonding interaction distance upon vibrational excitation. This is consistent with the observed infrared band origin for the (K,m) = (0,0) state of approximately 1021 cm-1, which is blue shifted by 71 cm-1 from the hypothetical inversion-free 950 cm-1 v2 band origin of uncomplexed NH3. The observed v5 band origin is also in good agreement with matrix-isolation results scaled to correct for the matrix shift of the NH3 umbrella frequency found in the recently studied NH3-HCN complex. The complex does not dissociate upon vibrational excitation, implying that the binding energy is greater than the laser frequency of approximately 1021 cm-1. RP FRASER, GT (reprint author), NATL INST STAND & TECHNOL,DIV MOLEC PHYS,GAITHERSBURG,MD 20899, USA. NR 47 TC 24 Z9 24 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 MAY 15 PY 1992 VL 96 IS 10 BP 7287 EP 7297 DI 10.1063/1.462433 PG 11 WC Chemistry, Physical; Physics, Atomic, Molecular & Chemical SC Chemistry; Physics GA HU557 UT WOS:A1992HU55700009 ER PT J AU SIGGEL, MRF HAYES, MA MACDONALD, MA WEST, JB DEHMER, JL PARR, AC HARDIS, JE IGA, I TIIT, V AF SIGGEL, MRF HAYES, MA MACDONALD, MA WEST, JB DEHMER, JL PARR, AC HARDIS, JE IGA, I TIIT, V TI RESONANCE EFFECTS IN THE 5-SIGMA-1 PHOTOIONIZATION CHANNEL OF CO SO JOURNAL OF CHEMICAL PHYSICS LA English DT Article ID VIBRATIONAL INTENSITY DISTRIBUTIONS; MOLECULAR PHOTO-IONIZATION; ANGULAR-DISTRIBUTION; CROSS-SECTIONS; BRANCHING RATIOS; PHOTOELECTRON-SPECTRUM; SYNCHROTRON RADIATION; CARBON-MONOXIDE; N-2; N2 AB Vibrational branching ratios and photoelectron angular distributions are reported for the 5-sigma-1 photoionization channel of CO in the range 16 eV < hv < 45 eV. Striking non-Franck-Condon effects are observed in both the branching ratios and angular distributions as a result of various autoionizing states and a sigma-shape resonance that lie in this spectral range. The goal of the present measurement was to observe definitive evidence for the sigma-shape resonance via its non-Franck-Condon effects on the vibrational ionization channels. Guided by recent calculations [ Smith, Lynch, and McKoy, J. Chem. Phys. 85, 6455 (1986) ], we examined the broad structure in the vibrational branching ratios and angular distributions in the range 25 eV < hv < 40 eV. There, we found clear evidence for the sigma-shape resonance in the quantities beta(upsilon+ = 0 and 1) and sigma(upsilon+ = 2)/sigma(upsilon+ = 0). Substantial differences between theory and experiment for the sigma(upsilon+ = 1)/sigma(upsilon+ = 0) branching ratio, however, serve to define the limitations of the current single-channel picture for this process. C1 ARGONNE NATL LAB,ARGONNE,IL 60439. NATL INST STAND & TECHNOL,GAITHERSBURG,MD 20899. UNIV FED SAO CARLOS,DEPT QUIM,BR-13560 SAO CARLOS,SP,BRAZIL. TARTU PHYS INST,202400 TARTU,ESTONIA,USSR. RP SIGGEL, MRF (reprint author), SERC,DARESBURY LAB,WARRINGTON WA4 4AD,CHESHIRE,ENGLAND. RI Iga, Ione/C-1273-2015 NR 50 TC 19 Z9 19 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 MAY 15 PY 1992 VL 96 IS 10 BP 7433 EP 7439 DI 10.1063/1.462393 PG 7 WC Chemistry, Physical; Physics, Atomic, Molecular & Chemical SC Chemistry; Physics GA HU557 UT WOS:A1992HU55700023 ER PT J AU LAVELLE, JW COWEN, JP MASSOTH, GJ AF LAVELLE, JW COWEN, JP MASSOTH, GJ TI A MODEL FOR THE DEPOSITION OF HYDROTHERMAL MANGANESE NEAR RIDGE CRESTS SO JOURNAL OF GEOPHYSICAL RESEARCH-OCEANS LA English DT Article ID NORTHEAST PACIFIC-OCEAN; DEEP SARGASSO SEA; MARINE SNOW; SURFACE SEDIMENTS; LATERAL TRANSPORT; VERTICAL FLUX; TRACE-METALS; FUCA RIDGE; PLUME; PARTICLES AB A two-stage scavenging model is used to describe the transport of hydrothermal Mn to the sediments adjacent to ridge crests. Dissolved Mn is hypothesized to be scavenged by slowly settling metal-depositing capsuled bacteria which, in turn, are incorporated into rapidly settling macroaggregates. Upon reaching the seafloor, the Mn is subject to resuspension in particulate form and to remobilization within the sediment column and release back into the water column as dissolved Mn. Measured Mn distributions in the vincinity of the southern Juan de Fuca Ridge and estimated values of process rate constants are used to limit the range of possible model outcomes. The results present a picture of water column distributions and fluxes of dissolved, fine particulate, and large-particle associated Mn in a plume advecting off axis. The model and best available parameter values suggest that more than 80% of the hydrothermal Mn is deposited within several hundred kilometers of the ridge crest, though dissolved Mn concentrations beyond that distance exceed background levels by many times. The residence time of hydrothermal Mn in the water column is of the order of several years. An off-axis component of advection of the order of 0.1-0.3 cm/s is needed to make similar the model and measured distributions of Mn depositing in the sediments. C1 UNIV HAWAII,DEPT OCEANOG,HONOLULU,HI 96822. RP LAVELLE, JW (reprint author), NOAA,PACIFIC MARINE ENVIRONM LAB,NOAA BLDG NUMBER 3,7600 SAND POINT WAY,SEATTLE,WA 98115, USA. NR 60 TC 26 Z9 27 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 1992 VL 97 IS C5 BP 7413 EP 7427 DI 10.1029/92JC00406 PG 15 WC Oceanography SC Oceanography GA HU911 UT WOS:A1992HU91100016 ER PT J AU KATTNER, UR BOETTINGER, WJ AF KATTNER, UR BOETTINGER, WJ TI THERMODYNAMIC CALCULATION OF THE TERNARY TI-AL-NB SYSTEM SO MATERIALS SCIENCE AND ENGINEERING A-STRUCTURAL MATERIALS PROPERTIES MICROSTRUCTURE AND PROCESSING LA English DT Article; Proceedings Paper CT 2ND INTERNATIONAL CONF ON HIGH TEMPERATURE ALUMINIDES AND INTERMETALLICS CY SEP 16-19, 1991 CL SAN DIEGO, CA SP AMER SOC MET ID PHASE-DIAGRAMS AB Phase equilibria of the ternary Ti-Al-Nb system are dominated by the large range of homogeneity of (beta-Ti,Nb), the binary intermetallic compounds of the Nb-Al and Ti-Al systems and the formation of two ternary compounds. The available ternary experimental data, together with a thermodynamic extrapolation of the ternary system from the binary systems. have been used to calculate the ternary phase diagram. The model descriptions of the Gibbs energies of most of these compounds are given by the existing calculations of the binary systems. In order to model a phase which is present in only one binary system, but has a ternary homogeneity range, a hypothetical phase with the same structure was analytically described for each binary system. Such a phase would, of course, be metastable in the other binary systems. Constraints on the Gibbs energies of formation were derived from the crystal structures of the corresponding ordered compounds. These same constraints were employed for the corresponding phases in the ternary system. In a final optimization step, ternary parameters were introduced and adjusted to the available experimental data. The as-derived description of the ternary Ti-Al-Nb system can be used to estimate single or multiphase fields and thermodynamic quantities where no experimental data are yet available. It is also useful as an indicator of problem areas for which additional experimental data are required. C1 UNIV WISCONSIN,DEPT MAT SCI & ENGN,MADISON,WI 53706. RP KATTNER, UR (reprint author), NATL INST STAND & TECHNOL,DIV MET,GAITHERSBURG,MD 20899, USA. NR 21 TC 105 Z9 110 U1 2 U2 21 PU ELSEVIER SCIENCE SA LAUSANNE PI LAUSANNE 1 PA PO BOX 564, 1001 LAUSANNE 1, SWITZERLAND SN 0921-5093 J9 MAT SCI ENG A-STRUCT JI Mater. Sci. Eng. A-Struct. Mater. Prop. Microstruct. Process. PD MAY 15 PY 1992 VL 152 IS 1-2 BP 9 EP 17 DI 10.1016/0921-5093(92)90039-4 PG 9 WC Nanoscience & Nanotechnology; Materials Science, Multidisciplinary; Metallurgy & Metallurgical Engineering SC Science & Technology - Other Topics; Materials Science; Metallurgy & Metallurgical Engineering GA JA968 UT WOS:A1992JA96800003 ER PT J AU BENDERSKY, LA BOETTINGER, WJ BIANCANIELLO, FS AF BENDERSKY, LA BOETTINGER, WJ BIANCANIELLO, FS TI INTERMETALLIC TI-AL-NB ALLOYS BASED ON STRENGTHENING OF THE ORTHORHOMBIC PHASE BY OMEGA-TYPE PHASES SO MATERIALS SCIENCE AND ENGINEERING A-STRUCTURAL MATERIALS PROPERTIES MICROSTRUCTURE AND PROCESSING LA English DT Article; Proceedings Paper CT 2ND INTERNATIONAL CONF ON HIGH TEMPERATURE ALUMINIDES AND INTERMETALLICS CY SEP 16-19, 1991 CL SAN DIEGO, CA SP AMER SOC MET ID TI3AL-NB ALLOY AB The microstructure of an alloy, with composition Ti-30Al-20Nb (atomic percent), when annealed at temperatures between 700 and 900-degrees-C for up to 18 days, consists of two intermetallic phases: orthorhombic Ti2AlNb and omega-type B8(2)Ti4Al3Nb. The presence of the two phases in the microstructure is independent of the heat treatment path and, thus, the two phases appear to be in thermodynamic equilibrium. The potential for high strength alloys in this two-phase field, based on the combination of properties of the two different phases, is demonstrated by microhardness measurements. RP BENDERSKY, LA (reprint author), NATL INST STAND & TECHNOL,DIV MET,GAITHERSBURG,MD 20899, USA. NR 15 TC 13 Z9 13 U1 1 U2 4 PU ELSEVIER SCIENCE SA LAUSANNE PI LAUSANNE 1 PA PO BOX 564, 1001 LAUSANNE 1, SWITZERLAND SN 0921-5093 J9 MAT SCI ENG A-STRUCT JI Mater. Sci. Eng. A-Struct. Mater. Prop. Microstruct. Process. PD MAY 15 PY 1992 VL 152 IS 1-2 BP 41 EP 47 DI 10.1016/0921-5093(92)90044-2 PG 7 WC Nanoscience & Nanotechnology; Materials Science, Multidisciplinary; Metallurgy & Metallurgical Engineering SC Science & Technology - Other Topics; Materials Science; Metallurgy & Metallurgical Engineering GA JA968 UT WOS:A1992JA96800008 ER PT J AU WHEELER, AA BOETTINGER, WJ MCFADDEN, GB AF WHEELER, AA BOETTINGER, WJ MCFADDEN, GB TI PHASE-FIELD MODEL FOR ISOTHERMAL PHASE-TRANSITIONS IN BINARY-ALLOYS SO PHYSICAL REVIEW A LA English DT Article ID GROWTH; BOUNDARY; INTERFACE; SELECTION; RATES AB In this paper we present a phase-field model to describe isothermal phase transitions between ideal binary-alloy liquid and solid phases. Governing equations are developed for the temporal and spatial variation of the phase field, which identifies the local state or phase, and for the composition. An asymptotic analysis as the gradient energy coefficient of the phase field becomes small shows that our model recovers classical sharp interface models of alloy solidification when the interfacial layers are thin, and we relate the parameters appearing in the phase-field model to material and growth parameters in real systems. We identify three stages of temporal evolution for the governing equations: the first corresponds to interfacial genesis, which occurs very rapidly; the second to interfacial motion controlled by diffusion and the local energy difference across the interface; the last takes place on a long time scale in which curvature effects are important, and corresponds to Ostwald ripening. We also present results of numerical calculations. C1 UNIV BRISTOL, SCH MATH, BRISTOL BS8 1TW, AVON, ENGLAND. RP NATL INST STAND & TECHNOL, GAITHERSBURG, MD 20899 USA. RI McFadden, Geoffrey/A-7920-2008 OI McFadden, Geoffrey/0000-0001-6723-2103 NR 29 TC 525 Z9 567 U1 10 U2 84 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 MAY 15 PY 1992 VL 45 IS 10 BP 7424 EP 7439 DI 10.1103/PhysRevA.45.7424 PG 16 WC Optics; Physics, Atomic, Molecular & Chemical SC Optics; Physics GA HV267 UT WOS:A1992HV26700056 ER PT J AU CAVANAGH, RR BECKERLE, JD CASASSA, MP HEILWEIL, EJ STEPHENSON, JC AF CAVANAGH, RR BECKERLE, JD CASASSA, MP HEILWEIL, EJ STEPHENSON, JC TI SUBPICOSECOND PROBING OF VIBRATIONAL-ENERGY TRANSFER AT SURFACES SO SURFACE SCIENCE LA English DT Article ID METAL-SURFACE; CO; ADSORPTION; LIFETIME; PT(111); SPECTROSCOPY; RELAXATION; NACL(100) AB Subpicosecond infrared pump-probe techniques are applied to the excited vibrational state dynamics of adsorbed CO on Pt(111). The CO (upsilon = 1) adlayer is probed as a function of IR pump fluence and CO coverage (0.1 less-than-or-equal-to THETA(CO) less-than-or-equal-to 0.5 ML). Spectral shifts in the transient CO vibrational spectrum are observed, indicative of a shift to lower frequency of the CO internal stretch mode as the degree of excitation of the adlayer is increased. The observed transient spectral response is discussed in terms of density matrix models which address the coherence time of the adlayer (upsilon = 1) excitation, and in terms of the excited state spectral characteristics of strongly coupled anharmonic oscillators. The two-to-three picosecond recovery time of the transient response is consistent with relaxation through electron-hole pair creation. C1 CLEMSON UNIV, DEPT CHEM, CLEMSON, SC 29634 USA. RP NATL INST STAND & TECHNOL, GAITHERSBURG, MD 20899 USA. NR 28 TC 21 Z9 21 U1 1 U2 4 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0039-6028 EI 1879-2758 J9 SURF SCI JI Surf. Sci. PD MAY 15 PY 1992 VL 269 BP 113 EP 119 DI 10.1016/0039-6028(92)91235-4 PN A PG 7 WC Chemistry, Physical; Physics, Condensed Matter SC Chemistry; Physics GA HW924 UT WOS:A1992HW92400018 ER PT J AU MICHEL, KH COPLEY, JRD NEUMANN, DA AF MICHEL, KH COPLEY, JRD NEUMANN, DA TI MICROSCOPIC THEORY OF ORIENTATIONAL DISORDER AND THE ORIENTATIONAL PHASE-TRANSITION IN SOLID C-60 SO PHYSICAL REVIEW LETTERS LA English DT Article ID CRYSTALS; C-60 AB We have developed a microscopic theory which describes the orientational dynamics of C60 molecules in the face-centered-cubic phase of C60 fullerite. The molecular interaction potential and the crystal-field potential are formulated in terms of symmetry-adapted rotator functions. The phase transition to the Pa3BAR structure is driven by an active multipolar mode of T2g symmetry belonging to the l = 10 manifold. The Birman criterion is satisfied. The transition is found to be of first order. C1 NATL INST STAND & TECHNOL,MAT SCI & ENGN LAB,GAITHERSBURG,MD 20899. RP MICHEL, KH (reprint author), UNIV INSTELLING ANTWERP,DEPT PHYS,B-2610 WILRIJK,BELGIUM. NR 26 TC 95 Z9 95 U1 0 U2 3 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 0031-9007 J9 PHYS REV LETT JI Phys. Rev. Lett. PD MAY 11 PY 1992 VL 68 IS 19 BP 2929 EP 2932 DI 10.1103/PhysRevLett.68.2929 PG 4 WC Physics, Multidisciplinary SC Physics GA HT648 UT WOS:A1992HT64800019 ER PT J AU GILLARD, D WYSS, M NAKATA, JS AF GILLARD, D WYSS, M NAKATA, JS TI A SEISMOTECTONIC MODEL FOR WESTERN HAWAII BASED ON STRESS TENSOR INVERSION FROM FAULT PLANE SOLUTIONS SO JOURNAL OF GEOPHYSICAL RESEARCH-SOLID EARTH LA English DT Article ID FOCAL MECHANISM DATA; SAN-ANDREAS FAULT; MAUNA-LOA; REGIONAL STRESS; EARTHQUAKE; TECTONICS; SEISMICITY; SEQUENCE; VOLCANOS; BENEATH AB For 57 fault plane solutions of earthquakes with magnitude M(L) greater-than-or-equal-to 3.0 located west of the southwest rift zone of Mauna Loa volcano in Hawaii, which occurred between 1972 and 1988, the dominant focal mechanisms (44 events) are decollement type with one nodal plane nearly horizontal (dip less-than-or-equal-to 30-degrees). The average slip vector of the upper crust on the decollement plane points in an azimuth of 260-degrees toward the ocean, away from Mauna Loa's southwest rift zone at an angle of about 150-degrees with respect to the NE-SW oriented rift. Two other types of focal mechanisms are present: normal faults (four events) and strike-slip faults with normal component (nine events). The orientation of the principal stresses was derived by minimizing the sum of the misfits between the theoretical and observed fault geometry for each focal mechanism. After subdividing the data set into three different regions we found that the stress tensor is not homogeneous in west Hawaii. The orientation for the stress tensor is best resolved in the area located between latitudes 19.27-degrees-N and 19.4-degrees-N and longitudes 155.7-degrees and 155.9-degrees-W where the greatest principal stress directions within the 95% confidence limits are nearly vertical with some spreading to the west. Their plunge varies between 53-degrees and 85-degrees. The intermediate and least principal stresses are mostly horizontal and have similar magnitudes. Their plunge varies between 1-degrees and 36-degrees. The area between latitudes 19.4-degrees and 19.6-degrees-N and longitudes 155.7-degrees and 156-degrees-W is characterized partly by near-vertical and partly by east-west oriented greatest principal stresses. The least principal stresses are approximately horizontal and have magnitudes similar to the intermediate principal stresses. In the two areas where the stress tensor was well resolved, the principal strain directions differed from the principal stress directions by 30-degrees in the plunge, suggesting that the faulting in western Hawaii takes place on a weak plane, but this result could not be established at the 95% confidence level. The tectonic model proposed for west Hawaii is similar to the model for the Kalapana region. The strain is accumulated through magmatic intrusions in the southwest rift zone of Mauna Loa, and the earthquakes occur along a zone of weakness composed of oceanic sediment at about 10 km depth. The west flank of Mauna Loa slips in the direction away from the rift. C1 US GEOL SURVEY,HAWAIIAN VOLCANO OBSERV,HAWAII NATL PK,HI 96718. UNIV COLORADO,NOAA,COOPERAT INST RES ENVIRONM SCI,BOULDER,CO 80309. UNIV COLORADO,DEPT GEOL SCI,BOULDER,CO 80309. NR 46 TC 26 Z9 28 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-SOL EA JI J. Geophys. Res.-Solid Earth PD MAY 10 PY 1992 VL 97 IS B5 BP 6629 EP 6641 DI 10.1029/91JB02709 PG 13 WC Geochemistry & Geophysics SC Geochemistry & Geophysics GA HT848 UT WOS:A1992HT84800006 ER PT J AU FALLON, FW DILLINGER, WH AF FALLON, FW DILLINGER, WH TI CRUSTAL VELOCITIES FROM GEODETIC VERY LONG BASE-LINE INTERFEROMETRY SO JOURNAL OF GEOPHYSICAL RESEARCH-SOLID EARTH LA English DT Article ID PLATE MOTIONS AB We have used very long baseline interferometry observations from the International Radio Interferometric Surveying and Crustal Dynamics Project programs taken over a time span of 5-8 years (through August 1990) to derive relative velocities of 16 sites on the North American, Eurasian, Pacific, and African plates. The data reduction scheme simultaneously estimates Earth orientation parameters and nutation for each session, local atmosphere and clock correction terms, source positions, and initial site positions, as well as the site velocities. No a priori geophysical crustal model whatsoever is imposed to obtain the velocities. Instead we introduce a minimal set of geometric constraints to obtain the solution. Two alterative constraint formulations are considered; they are shown to be equivalent in that they yield equivalent velocity sets with allowance for translation and rotation. These are (1) setting the secular motion of the pole and mean length of day to fixed values and (2) fixing the net rotation of the sites. The resulting velocities have formal standard errors typically < 0.2 cm/yr, and most velocities are significantly different from zero. They agree closely to within 0.5 cm/yr, with velocities predicted by the Minster-Jordan and NUVEL-1 plate motion models, after allowing for the arbitrary rotation and translation between the systems. The velocity of Kashima, Japan, is much more consistent with the North American plate than the Eurasian plate where current plate model boundaries place it. We suggest another possibility: Kashima does lie on the Eurasia plate, but its motion is so modified by interaction with the nearby Pacific plate as to result in the observed velocity. Sites near the active plate boundary in California also show motions intermediate between those of the adjoining plates. RP FALLON, FW (reprint author), NOAA,NATL OCEAN SERV,NATL GEODET SURVEY,CHARTING & GEODET SERV,OFF OCEAN & EARTH SCI,ROCKVILLE,MD 20852, USA. NR 20 TC 11 Z9 11 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-SOL EA JI J. Geophys. Res.-Solid Earth PD MAY 10 PY 1992 VL 97 IS B5 BP 7129 EP 7136 DI 10.1029/92JB00351 PG 8 WC Geochemistry & Geophysics SC Geochemistry & Geophysics GA HT848 UT WOS:A1992HT84800034 ER PT J AU SOLOMON, S ALBRITTON, DL AF SOLOMON, S ALBRITTON, DL TI TIME-DEPENDENT OZONE DEPLETION POTENTIALS FOR SHORT-TERM AND LONG-TERM FORECASTS SO NATURE LA English DT Article ID STRATOSPHERIC OZONE AB Assessments of long-term ozone depletion by CFCs have relied on their relative effects as quantified by ozone depletion potentials (ODPs). These long-term ODPs, based on steady-state atmospheric impacts, are not appropriate for making shorter-term (decade-scale) forecasts. Time-dependent ODPs, derived using an empirical approach, show that some of the hydrochlorofluorocarbons proposed as replacements for CFCs may induce significant ozone destruction in the short term. RP SOLOMON, S (reprint author), NOAA,AERON LAB,BOULDER,CO 80303, USA. NR 14 TC 73 Z9 73 U1 1 U2 7 PU MACMILLAN MAGAZINES LTD PI LONDON PA PORTERS SOUTH, 4 CRINAN ST, LONDON, ENGLAND N1 9XW SN 0028-0836 J9 NATURE JI Nature PD MAY 7 PY 1992 VL 357 IS 6373 BP 33 EP 37 DI 10.1038/357033a0 PG 5 WC Multidisciplinary Sciences SC Science & Technology - Other Topics GA HT229 UT WOS:A1992HT22900050 ER PT J AU KRAUSS, M BASCH, H AF KRAUSS, M BASCH, H TI IS THE VANADATE ANION AN ANALOG OF THE TRANSITION-STATE OF RNASE-A SO JOURNAL OF THE AMERICAN CHEMICAL SOCIETY LA English DT Article ID NEUTRON-DIFFRACTION; URIDINE VANADATE; RIBONUCLEASE-A; ACTIVE-SITE; BASIS-SETS; ABINITIO; CATALYSIS; MECHANISM; COMPLEX; ION AB The electronic structures of models of the monoanion phosphorane transition state in ribonuclease A and its putative vanadate transition-state analogue are compared. The electrostatic potential and gross atomic populations agree well for the vanadium and phosphorus trigonal-bipyramidal transition-state structures for both equatorial and axial bonds to hydroxyl ligands but are different for the V-O and P-O bonds. The P-O bond is semiionic but V-O is a multiple bond that is much less polar. A similar difference in the polarity between P-O and V-O is found for the dianion. Ionic hydrogen bonds to the cationic residues will not be comparable between the V-O and P-O bonds. The vanadium compound is not a transition-state analogue for such H-bonds. The pattern of Lys-41 and His-12 residue bonding observed for the vanadate-inhibited RNase A should not be used to analyze the mechanism. Proton transfer between the five-coordinate transition state and the His-119 residue is a step in both the cyclization and hydrolysis phases of the mechanism. The proton transfer curve from the equatorial hydroxyl ligand to a model of His-119 is calculated to be essentially equivalent for the vanadium and phosphorus five-coordinate models of the active site. Residue binding to the vanadate monoanion would be analogous to stabilization of the transition-state intermediate. Stable vanadium dianion intermediates, which are electronic analogues of the dissociative phosphorus dianion, are calculated with both equatorial-equatorial and equatorial-axial deprotonated oxygen sites. The equatorial-axial dianion is lowest in energy and accounts for the binding of the His-119 residue in the vanadium system although the binding is weaker than for the phosphorus analogue. C1 BAR ILAN UNIV,DEPT CHEM,RAMAT GAN,ISRAEL. RP KRAUSS, M (reprint author), NATL INST STAND & TECHNOL,CTR ADV RES BIOTECHNOL,GAITHERSBURG,MD 20899, USA. NR 25 TC 32 Z9 32 U1 0 U2 2 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 SN 0002-7863 J9 J AM CHEM SOC JI J. Am. Chem. Soc. PD MAY 6 PY 1992 VL 114 IS 10 BP 3630 EP 3634 DI 10.1021/ja00036a008 PG 5 WC Chemistry, Multidisciplinary SC Chemistry GA HT801 UT WOS:A1992HT80100008 ER PT J AU REIZER, J SUTRINA, SL WU, LF DEUTSCHER, J REDDY, P SAIER, MH AF REIZER, J SUTRINA, SL WU, LF DEUTSCHER, J REDDY, P SAIER, MH TI FUNCTIONAL INTERACTIONS BETWEEN PROTEINS OF THE PHOSPHOENOLPYRUVATE-SUGAR PHOSPHOTRANSFERASE SYSTEMS OF BACILLUS-SUBTILIS AND ESCHERICHIA-COLI SO JOURNAL OF BIOLOGICAL CHEMISTRY LA English DT Article ID GRAM-POSITIVE BACTERIA; PHOSPHO-CARRIER PROTEIN; SALMONELLA-TYPHIMURIUM; INDUCER EXCLUSION; ENZYME-I; STAPHYLOCOCCUS-AUREUS; NUCLEOTIDE-SEQUENCE; LACTOSE TRANSPORT; CRR GENES; IIIGLC AB Proteins of the phosphoenolpyruvate:sugar phosphotransferase system (PTS) of Bacillus subtilis were overexpressed, purified to near homogeneity, and characterized. The proteins isolated include Enzyme I, HPr, the glucose-specific IIA domain of the glucose-specific Enzyme II (IIA(glc)), and the mannitol-specific IIA protein, IIA(mtl). Site specific mutant proteins of IIA(glc) and HPr were also overexpressed and purified, and their properties were compared with those of the wild type proteins. These proteins and their phosphorylated derivatives were characterized with respect to their immunological cross-reactivities employing the Western blot technique and in terms of their migratory behavior during sodium dodecyl sulfate-gel electrophoresis, nondenaturing gel electrophoresis, and isoelectric focusing. The interactions between homologous and heterologous Enzymes I and HPrs, between homologous and heterologous HPrs and the IIA(glc) proteins, and between homologous and heterologous IIAg(glc) proteins and IIBC(scr) of B. subtilis as well as IICB(glc) of Escherichia coli were defined and compared kinetically. The mutant HPrs and IIA(glc) proteins were also characterized kinetically as PTS phosphocarrier proteins and/or as inhibitors of the phosphotransferase reactions of the PTS. These studies revealed that complexation of IIA(glc) with the mutant form of HPr in which serine 46 was replaced by aspartate (S46D) did not increase the rate of phosphoryl transfer from phospho Enzyme I to S46D HPr more than when IIA(mtl) was complexed to S46D HPr. These findings do not support a role for HPr(Ser-P) in the preferential utilization of one PTS carbohydrate relative to another. Functional analyses in E. coli established that IIA(glc) of B. subtilis can replace IIA(glc) of E. coli with respect both to sugar transport and to regulation of non-PTS permeases, catabolic enzymes, and adenylate cyclase. Site-specific mutations in histidyl residues 68 and 83 (H68A and H83A) inactivated IIA(glc) of B. subtilis with respect to phosphoryl transfer and its various regulatory roles. C1 NATL INST STANDARDS & TECHNOL,CTR ADV RES BIOTECHNOL,ROCKVILLE,MD 20850. RP REIZER, J (reprint author), UNIV CALIF SAN DIEGO,DEPT BIOL,LA JOLLA,CA 92093, USA. FU NIAID NIH HHS [2R01 AI 14176, 5R01 AI 21702] NR 53 TC 110 Z9 110 U1 0 U2 0 PU AMER SOC BIOCHEMISTRY MOLECULAR BIOLOGY INC PI BETHESDA PA 9650 ROCKVILLE PIKE, BETHESDA, MD 20814 SN 0021-9258 J9 J BIOL CHEM JI J. Biol. Chem. PD MAY 5 PY 1992 VL 267 IS 13 BP 9158 EP 9169 PG 12 WC Biochemistry & Molecular Biology SC Biochemistry & Molecular Biology GA HR854 UT WOS:A1992HR85400071 PM 1577753 ER PT J AU SIGMUNDSSON, F AF SIGMUNDSSON, F TI TECTONIC IMPLICATIONS OF THE 1989 AFAR EARTHQUAKE SEQUENCE SO GEOPHYSICAL RESEARCH LETTERS LA English DT Article ID RIFT; SEISMICITY; VOLCANISM; ICELAND AB In August 1989 a sequence of m(b) 5-6 normal faulting earthquakes occurred in the area between the Ghoubbet Asal-Manda Inakir and Manda Haroro-Abhe Bad rifts in central Afar. Relocation of the events suggest they occurred on major faults in the Dobi graben, located midway between the principal rift zones. The earthquakes are evidence that extensional strain is still occurring in the area. The bookshelf tectonic model for central and southern Afar proposed by Tapponnier et al. [1990] is modified to account for ongoing extension in the area between the principal rifts as well as distributed shear. C1 UNIV COLORADO,NOAA,COOPERAT INST RES ENVIRONM SCI,DEPT GEOL SCI,BOULDER,CO 80309. RP SIGMUNDSSON, F (reprint author), UNIV COLORADO,NOAA,COOPERAT INST RES ENVIRONM SCI,CAMPUS BOX 216,BOULDER,CO 80309, USA. RI Sigmundsson, Freysteinn/F-7160-2015 OI Sigmundsson, Freysteinn/0000-0001-9052-4665 NR 23 TC 32 Z9 32 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 MAY 4 PY 1992 VL 19 IS 9 BP 877 EP 880 DI 10.1029/92GL00686 PG 4 WC Geosciences, Multidisciplinary SC Geology GA HT894 UT WOS:A1992HT89400009 ER PT J AU MILLER, AJ NAGATANI, RM TIAO, GC NIU, XF REINSEL, GC WUEBBLES, D GRANT, K AF MILLER, AJ NAGATANI, RM TIAO, GC NIU, XF REINSEL, GC WUEBBLES, D GRANT, K TI COMPARISONS OF OBSERVED OZONE AND TEMPERATURE TRENDS IN THE LOWER STRATOSPHERE SO GEOPHYSICAL RESEARCH LETTERS LA English DT Article ID APPROXIMATION AB One result of the Ozone Assessment [WMO, 1989] is that there is a significant negative ozone trend in the lower stratosphere and upper troposphere from 1970 through 1986. In this paper we examine the relationship of this trend in ozone to that of temperature in the same altitude region utilizing a 62 station set of rawinsonde data, and compare the results to the changes in temperature determined from a radiative equilibrium model calculation. The calculated and observed trends in lower stratospheric temperature indicate substantive agreement in shape and magnitude of the vertical profiles. C1 UNIV CHICAGO, GRAD SCH BUSINESS, CHICAGO, IL 60637 USA. UNIV WISCONSIN, GRAD SCH BUSINESS, MADISON, WI 53706 USA. UNIV CALIF LAWRENCE LIVERMORE NATL LAB, LIVERMORE, CA 94550 USA. RP MILLER, AJ (reprint author), NATL WEATHER SERV, CTR CLIMATE ANAL, 5200 AUTH RD, WASHINGTON, DC 20233 USA. NR 15 TC 40 Z9 40 U1 0 U2 0 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 0094-8276 J9 GEOPHYS RES LETT JI Geophys. Res. Lett. PD MAY 4 PY 1992 VL 19 IS 9 BP 929 EP 932 DI 10.1029/92GL00778 PG 4 WC Geosciences, Multidisciplinary SC Geology GA HT894 UT WOS:A1992HT89400022 ER PT J AU LIN, CJ NGUYEN, T MCKNIGHT, ME AF LIN, CJ NGUYEN, T MCKNIGHT, ME TI RELATION BETWEEN AC IMPEDANCE DATA AND DEGRADATION OF COATED STEEL .1. EFFECTS OF SURFACE-ROUGHNESS AND CONTAMINATION ON THE CORROSION BEHAVIOR OF EPOXY-COATED STEEL SO PROGRESS IN ORGANIC COATINGS LA English DT Review ID NON-METALLIC COATINGS; ELECTROCHEMICAL IMPEDANCE; PAINTED METALS; SPECTROSCOPY; PERFORMANCE; INTERFACE AB The effects of surface roughness and inorganic chloride contamination on the corrosion behavior of steel coated with thin, amine-cured epoxy films have been investigated using AC impedance spectroscopy. The results were analyzed using the equivalent circuit models to identify the different steps in the corrosion of coated steel. Two types of corrosion were observed depending on the surface treatment: point-attack corrosion for uncontaminated and blistered corrosion for contaminated surfaces. Both types of corrosion can be discerned by AC impedance spectroscopy and modeled by the equivalent circuits. Coating-deficient areas at the peaks of sandblasted substrate have been calculated accurately from the AC impedance data and verified by scanning electron microscopy. C1 NATL INST STAND & TECHNOL,GAITHERSBURG,MD 20899. NR 39 TC 9 Z9 11 U1 2 U2 5 PU ELSEVIER SCIENCE SA LAUSANNE PI LAUSANNE 1 PA PO BOX 564, 1001 LAUSANNE 1, SWITZERLAND SN 0300-9440 J9 PROG ORG COAT JI Prog. Org. Coat. PD MAY 4 PY 1992 VL 20 IS 2 BP 169 EP 186 DI 10.1016/0033-0655(92)80003-F PG 18 WC Chemistry, Applied; Materials Science, Coatings & Films SC Chemistry; Materials Science GA HV417 UT WOS:A1992HV41700003 ER PT J AU AN, M LU, C PRINCE, E TOLIMIERI, R AF AN, M LU, C PRINCE, E TOLIMIERI, R TI FAST FOURIER-TRANSFORMS FOR SPACE-GROUPS CONTAINING ROTATION AXES OF ORDER-3 AND HIGHER SO ACTA CRYSTALLOGRAPHICA SECTION A LA English DT Article ID ORGANIC STRUCTURES; GROUPS RARE AB Methods are described for exploiting the symmetry of uniaxial space groups containing rotation axes of order three and higher to improve the efficiency of computation of Fourier transforms. Mapping a symmetrical two-dimensional section into four dimensions enables the selection of non-contiguous asymmetric units over which fast Fourier transforms can be performed that reduce the computation time by a factor of approximately the order of the rotation axis. The application of the procedure to plane group p3 and its extension to p4 and p6 are described. C1 NATL INST STAND & TECHNOL,MAT SCI & ENGN LAB,GAITHERSBURG,MD 20899. CUNY,CTR LARGE SCALE COMPUTAT,NEW YORK,NY 10036. TOWSON STATE UNIV,DEPT COMP & INFORMAT SCI,BALTIMORE,MD 21204. NR 9 TC 2 Z9 2 U1 0 U2 0 PU MUNKSGAARD INT PUBL LTD PI COPENHAGEN PA 35 NORRE SOGADE, PO BOX 2148, DK-1016 COPENHAGEN, DENMARK SN 0108-7673 J9 ACTA CRYSTALLOGR A JI Acta Crystallogr. Sect. A PD MAY 1 PY 1992 VL 48 BP 346 EP 349 DI 10.1107/S0108767391015027 PN 3 PG 4 WC Chemistry, Multidisciplinary; Crystallography SC Chemistry; Crystallography GA HW037 UT WOS:A1992HW03700015 ER PT J AU LARCHE, FC CAHN, JW AF LARCHE, FC CAHN, JW TI PHASE-CHANGES IN A THIN PLATE WITH NONLOCAL SELF-STRESS EFFECTS SO ACTA METALLURGICA ET MATERIALIA LA English DT Article ID CAHN-HILLIARD EQUATION; SOLIDS; TRANSITIONS; SEPARATION; DIFFUSION; KINETICS AB Because the stress resulting from compositional inhomogeneities are long range, the local stress, diffusional flux and equilibrium conditions at a point depend on the entire composition distribution in a specimen. For a thin plate with a one-dimensional composition profile, this dependence is simple; the local stress depends on the local composition and on both the average composition and the first moment of the composition profile, neither of which are local. A theory of diffusion and equilibrium in a thin plate is developed, based on a free energy that depends on composition, its gradients and strain, and has a term for chemical effects at the plate boundary. Under certain assumptions, a standard diffusion equation is derived, with all of the non-local stress effects in the boundary conditions. Solutions are altered by these new conditions. Spontaneous bending is often a natural result of diffusion. C1 NATL INST STAND & TECHNOL, MAT SCI & ENGN LAB, GAITHERSBURG, MD 20899 USA. RP UNIV MONTPELLIER 2, GDPC, F-34095 MONTPELLIER 5, FRANCE. NR 32 TC 62 Z9 62 U1 0 U2 19 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 1992 VL 40 IS 5 BP 947 EP 955 DI 10.1016/0956-7151(92)90071-L PG 9 WC Materials Science, Multidisciplinary; Metallurgy & Metallurgical Engineering SC Materials Science; Metallurgy & Metallurgical Engineering GA HP055 UT WOS:A1992HP05500007 ER PT J AU ATKINSON, R BAULCH, DL COX, RA HAMPSON, RF KERR, JA TROE, J AF ATKINSON, R BAULCH, DL COX, RA HAMPSON, RF KERR, JA TROE, J TI EVALUATED KINETIC AND PHOTOCHEMICAL DATA FOR ATMOSPHERIC CHEMISTRY - INTRODUCTION SO ATMOSPHERIC ENVIRONMENT PART A-GENERAL TOPICS LA English DT Article C1 UNIV CALIF RIVERSIDE, DEPT SOIL & ENVIRONM SCI, RIVERSIDE, CA 92521 USA. UNIV LEEDS, SCH CHEM, LEEDS LS2 9JT, W YORKSHIRE, ENGLAND. UNIV OXFORD, ROBERT HOOKE INST, OXFORD OX1 3QZ, ENGLAND. NATL INST STAND & TECHNOL, CTR CHEM KINET DATA, GAITHERSBURG, MD 20899 USA. ETH, EAWAG, SWISS FED INST TECHNOL, CH-8600 DUBENDORF, SWITZERLAND. UNIV GOTTINGEN, INST PHYS CHEM, W-3400 GOTTINGEN, GERMANY. RP ATKINSON, R (reprint author), UNIV CALIF RIVERSIDE, STATEWIDE AIR POLLUT RES CTR, RIVERSIDE, CA 92521 USA. NR 0 TC 106 Z9 108 U1 1 U2 16 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD, ENGLAND OX5 1GB SN 0004-6981 J9 ATMOS ENVIRON A-GEN PD MAY PY 1992 VL 26 IS 7 BP 1187 EP 1230 DI 10.1016/0960-1686(92)90383-V PG 44 WC Environmental Sciences; Meteorology & Atmospheric Sciences SC Environmental Sciences & Ecology; Meteorology & Atmospheric Sciences GA HM115 UT WOS:A1992HM11500001 ER PT J AU EANES, ED AF EANES, ED TI MIXED PHOSPHOLIPID LIPOSOME CALCIFICATION SO BONE AND MINERAL LA English DT Article; Proceedings Paper CT 5TH INTERNATIONAL CONF ON CELL MEDIATED CALCIFICATION AND MATRIX VESICLES CY NOV 16-20, 1991 CL HILTON HEAD, SC SP NIH, NIAMSD, CIBA GEIGY, DEPUY, ELECTROBIOLOGY, GLAXO, INST RECH INT SERVIER, LILLY RES LABS, MILES, ABBOTT LABS ID CALCIUM-PHOSPHATE FORMATION; CONTAINING ANIONIC LIPOSOMES; EPIPHYSEAL CARTILAGE; AQUEOUS SUSPENSIONS; MATRIX VESICLES AB Synthetic lipid vesicle (liposome) suspensions have been used to experimentally model many of the calcium phosphate precipitation steps observed in matrix vesicle (MV) calcification. In particular, precipitate development in liposomes can be made to preferentially follow the progression seen in MV, i.e. to occur initially in intraliposomal spaces and then to expand into the surrounding suspending medium. This paper reviews results from studies by us which show that certain phospholipid (PL) constituents of the liposomal membrane can modulate this progression. Of greatest relevance to MV calcification is the observation that phosphatidylserine and sphingomyelin, two lipids selectively enriched in MV, slow the expansion of the precipitation from inside to outside the liposome. RP EANES, ED (reprint author), NATL INST STAND & TECHNOL,NIDR,BONE RES BRANCH,RES ASSOCIATE PROGRAM,GAITHERSBURG,MD 20899, USA. NR 10 TC 15 Z9 15 U1 1 U2 1 PU ELSEVIER SCI IRELAND LTD PI CLARE PA CUSTOMER RELATIONS MANAGER, BAY 15, SHANNON INDUSTRIAL ESTATE CO, CLARE, IRELAND SN 0169-6009 J9 BONE MINER JI Bone Miner. PD MAY PY 1992 VL 17 IS 2 BP 269 EP 272 DI 10.1016/0169-6009(92)90749-4 PG 4 WC Endocrinology & Metabolism SC Endocrinology & Metabolism GA HT304 UT WOS:A1992HT30400031 PM 1611319 ER PT J AU AUBLE, DL MEYERS, TP AF AUBLE, DL MEYERS, TP TI AN OPEN PATH, FAST RESPONSE INFRARED-ABSORPTION GAS ANALYZER FOR H2O AND CO2 SO BOUNDARY-LAYER METEOROLOGY LA English DT Article ID FLUX MEASUREMENTS; WATER-VAPOR; HYGROMETER AB An open path infrared absorption based instrument for fast response measurements of H2O and CO2 fluctuations is described. This instrument performed reliably in several field experiments in both terrestrial and marine environments, on both fixed (tower) and mobile (boat, plane) flux platforms. Noise levels for H2O and CO2 concentrations were less than 10 mg/m3 and 300-mu-g/m3 respectively for frequencies between 0.005 and 10 Hz. Drifts in instrument output, associated with changes in instrument temperature, are compensated for electronically. RP AUBLE, DL (reprint author), NOAA,AIR RESOURCES LAB,DIV ATMOSPHER TURBULENCE & DIFFUS,POB 2456,OAK RIDGE,TN 37831, USA. RI Meyers, Tilden/C-6633-2016 NR 24 TC 106 Z9 107 U1 0 U2 7 PU KLUWER ACADEMIC PUBL PI DORDRECHT PA SPUIBOULEVARD 50, PO BOX 17, 3300 AA DORDRECHT, NETHERLANDS SN 0006-8314 J9 BOUND-LAY METEOROL JI Bound.-Layer Meteor. PD MAY PY 1992 VL 59 IS 3 BP 243 EP 256 DI 10.1007/BF00119815 PG 14 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA HV734 UT WOS:A1992HV73400004 ER PT J AU CRAWFORD, TL DOBOSY, RJ AF CRAWFORD, TL DOBOSY, RJ TI A SENSITIVE FAST-RESPONSE PROBE TO MEASURE TURBULENCE AND HEAT-FLUX FROM ANY AIRPLANE SO BOUNDARY-LAYER METEOROLOGY LA English DT Article AB The theory, configuration, and accuracy of an inexpensive probe to measure turbulence from a small airplane are presented. The probe employs a nine-hole pressure-sphere design along with inprobe high-frequency pressure, temperature, and acceleration sensors. This sensor suite is specifically designed to extend mass, momentum and energy eddy-flux measurement to the higher frequencies characteristic of marine and nocturnal boundary layers. The probe is part of a mobile flux system. independent of the conveyance, which does not require a separate Inertial Navigation System. The new nine-port pressure sphere turbulence probe allows accurate turbulent velocity measurement with proper probe installation and appropriate computation technique for dynamic pressure. A thermistor in the central pressure port provides simultaneous temperature measurement, at a location symmetrical with respect to the flow, for accurate determination of true airspeed and heat flux. The probe-amounted temperature sensor gives heat fluxes with variance 5% of the mean in a weakly-turbulent marine boundary layer. RP CRAWFORD, TL (reprint author), NOAA,AIR RESOURCES LAB,DIV ATMOSPHER TURBULENCE & DIFFUS,OAK RIDGE,TN 37831, USA. RI Dobosy, Ronald/C-3303-2016 OI Dobosy, Ronald/0000-0001-8399-8774 NR 18 TC 72 Z9 73 U1 0 U2 5 PU KLUWER ACADEMIC PUBL PI DORDRECHT PA SPUIBOULEVARD 50, PO BOX 17, 3300 AA DORDRECHT, NETHERLANDS SN 0006-8314 J9 BOUND-LAY METEOROL JI Bound.-Layer Meteor. PD MAY PY 1992 VL 59 IS 3 BP 257 EP 278 DI 10.1007/BF00119816 PG 22 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA HV734 UT WOS:A1992HV73400005 ER PT J AU MUNROE, TA AF MUNROE, TA TI INTERDIGITATION PATTERN OF DORSAL-FIN PTERYGIOPHORES AND NEURAL SPINES, AN IMPORTANT DIAGNOSTIC CHARACTER FOR SYMPHURINE TONGUEFISHES (SYMPHURUS, CYNOGLOSSIDAE, PLEURONECTIFORMES) SO BULLETIN OF MARINE SCIENCE LA English DT Article ID EASTERN PACIFIC; ATLANTIC TONGUEFISHES; FISHES; LARVAE AB Numbers of proximal dorsal-fin pterygiophores in each of the anterior most five interneural spaces (ID patterns) were examined in 69 of 71 nominal species of symphurine (Symphurus) tonguefishes and were found to be of diagnostic value. All species of Symphurus typically have a single pterygiophore inserted into the first interneural space, a unique arrangement among the Cynoglossidae and related taxa that supports the monophyly of the genus. All but seven species in the genus usually have two pterygiophores inserted into interneural spaces four and five. Observed variation among species in ID patterns, therefore, results primarily from different numbers of pterygiophores inserting into interneural spaces two and three. Formulae for individual ID patterns listed below, with a single exception, are abbreviated to represent the pterygiophore arrangements in the first three interneural spaces. Nine different predominant ID patterns were discovered among 69 species examined. These patterns and the numbers of nominal species (in parentheses) possessing each are as follows: 1-2-2-1-2 (7), 1-2-2 (16); 1-2-3 (3); 1-3-2 (15); 1-3-3 (4); 1-3-4 (1); 1-4-2 (4); 1-4-3 (11); and 1-5-3 (8). Overall, average fidelity for the predominant ID pattern was approximately 78% per species, with values ranging from 37 to 100% per species. Forty-eight species had 70% or more of the individuals possessing the predominant ID pattern; seven had 60% or more with the predominant ID pattern; and only four of 69 species had 50% or fewer of the individuals with the predominant ID pattern Less than 5% of the individuals per species had anomalous ID patterns that provided little or no useful information for identification of the specimens. Between 0 and 37% of the individuals for most species had variant ID patterns that were predominant patterns recorded for other species. Twenty of 24 New World species with 1-3-4, 1-4-2, 1-4-3, and 1-5-3 ID patterns had between 0 and 43% of the individuals per species with secondary ID patterns that occurred uniquely in species characterized by these predominant ID patterns. Intraspecific variation in ID patterns was limited and predictable for each species and was found to be largely non-overlapping among species with different predominant patterns. ID patterns are an important diagnostic character for Symphurus, especially when used in combination with caudal- and dorsal-fin ray counts. Geographical ranges of species characterized by each predominant ID pattern were plotted within four major marine faunal regions revealing interesting distributions for species with different predominant patterns. Species with 1-2-2-1-2 and 1-2-2 ID patterns occur predominantly, while those with a 1-2-3 occur exclusively, in deep-sea habitats throughout temperate and tropical regions of the Indo-Pacific. Only one species with a 1-2-2-1-2 ID pattern and two with the 1-2-2 pattern occur in the Atlantic, while no species with these three ID patterns is found in the eastern Pacific. Species characterized by other ID patterns are not found in the Indo-Pacific region. Those with the 1-3-2 and 1-3-3 ID pattern occur only in northern and southern hemispheres of the Atlantic Ocean and in the tropical eastern Pacific from the Gulf of California to northern Peru. Species with 1-3-4, 1-4-2, 1-4-3, and 1-5-3 ID patterns are found only in the New World- Symphurus callopterus, the only species with the 1-3-4 ID pattern, and all species with the 1-5-3 ID pattern occur in temperate and tropical regions of the eastern Pacific. Four species characterized by the 1-4-2 ID pattern occur entirely in the western Atlantic, while those with a 1-4-3 pattern occur in shallow-water environments of the western Atlantic and eastern Pacific Oceans. RP MUNROE, TA (reprint author), NOAA,NATL MARINE FISHERIES SERV,SYSTEMAT LAB,NATL MUSEUM NAT HIST,WASHINGTON,DC 20560, USA. NR 91 TC 30 Z9 31 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 1992 VL 50 IS 3 BP 357 EP 403 PG 47 WC Marine & Freshwater Biology; Oceanography SC Marine & Freshwater Biology; Oceanography GA JK046 UT WOS:A1992JK04600001 ER PT J AU GITTINGS, SR BRIGHT, TJ SCHROEDER, WW SAGER, WW LASWELL, JS REZAK, R AF GITTINGS, SR BRIGHT, TJ SCHROEDER, WW SAGER, WW LASWELL, JS REZAK, R TI INVERTEBRATE ASSEMBLAGES AND ECOLOGICAL CONTROLS ON TOPOGRAPHIC FEATURES IN THE NORTHEAST GULF OF MEXICO SO BULLETIN OF MARINE SCIENCE LA English DT Article ID FLOWER GARDEN BANKS; NORTHWESTERN GULF; REEF CORALS; BRINE SEEP AB Biological assemblages dominated by suspension-feeding, tropical hard-bottom organisms occupy a variety of topographic features between 53 and 110 m in the northeastern Gulf of Mexico between the Mississippi River and DeSoto Canyon. Though some features may have been formed by hermatypic organisms, present-day production of calcium carbonate is limited to an impoverished calcareous algae population on features cresting above 78 m. Deeper features are considered drowned reefs or relict features unable to sustain hermatypic organisms. Faunal assemblages are of low richness and depauperate on features with relief less than 2 meters. Both richness and abundance is higher on features of 2-6 m relief. All features with relief between 6 and 18 m (the highest relief observed) harbor dense assemblages whose composition varies with habitat type. Reefs with horizontal summits harbor large populations of sponges, tall antipatharians and gorgonians, and comatulid crinoids. Vertical or rugged surfaces are dominated by ahermatypic corals. Variation between epibenthic development on features is attributable, in many cases, to differences in the potential for sedimentation. The Mississippi River plume may limit hard-bottom community development up to 70 km east of the river delta, an area much smaller than that affected to the west of the delta. Communities on these features are most like those at similar depths on outer continental shelf banks in the northwestern Gulf of Mexico, at shallower depths on mid-shelf banks in the northwest Gulf, and on south Texas banks. C1 TEXAS A&M UNIV SYST,DEPT OCEANOG,COLL STN,TX 77843. UNIV ALABAMA,MARINE SCI PROGRAM,DAUPHIN ISL,AL 36528. RP GITTINGS, SR (reprint author), FLOWER GARDEN BANKS NATL MARINE SANCTUARY,1716 BRIARCREST,SUITE 702,BRYAN,TX 77802, USA. NR 53 TC 7 Z9 7 U1 1 U2 5 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 1992 VL 50 IS 3 BP 435 EP 455 PG 21 WC Marine & Freshwater Biology; Oceanography SC Marine & Freshwater Biology; Oceanography GA JK046 UT WOS:A1992JK04600005 ER PT J AU HANSON, HP HANSON, CS YOO, BH AF HANSON, HP HANSON, CS YOO, BH TI RECENT GREAT-LAKES ICE TRENDS SO BULLETIN OF THE AMERICAN METEOROLOGICAL SOCIETY LA English DT Article ID CLIMATE CHANGE; COVER; TEMPERATURES; RECORD AB Analysis of ice observations made by cooperative observers from shoreline stations reveals significant changes in the ice season on the North American Great Lakes over the past 35 years. Although the dataset is highly inhomogeneous and year-to-year variability is also quite large, there is a statistically significant indication that the end of the ice season (as defined by the time at which ice departs from the observer stations in spring) has come increasingly early at a number of locations. The earlier ice departure is reflected in a somewhat earlier spring runoff through the St. Lawrence River over the same time period and correlates with increases in springtime temperatures at stations in the region. This example of a trend toward warmer, earlier springs in the upper Midwest is consistent with results from a number of other regional datasets. Because the ice observations began in the mid-1950s, other analyses, including comparisons with modern satellite datasets, could provide a useful tool for monitoring future climate change. RP HANSON, HP (reprint author), UNIV COLORADO,NOAA,COOPERAT INST RES ENVIRONM SCI,BOULDER,CO 80309, USA. NR 27 TC 26 Z9 26 U1 0 U2 4 PU AMER METEOROLOGICAL SOC PI BOSTON PA 45 BEACON ST, BOSTON, MA 02108-3693 SN 0003-0007 J9 B AM METEOROL SOC JI Bull. Amer. Meteorol. Soc. PD MAY PY 1992 VL 73 IS 5 BP 577 EP 584 DI 10.1175/1520-0477(1992)073<0577:RGLIT>2.0.CO;2 PG 8 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA HU545 UT WOS:A1992HU54500001 ER PT J AU KRAYER, WR MARSHALL, RD AF KRAYER, WR MARSHALL, RD TI GUST FACTORS APPLIED TO HURRICANE WINDS SO BULLETIN OF THE AMERICAN METEOROLOGICAL SOCIETY LA English DT Article AB An important consideration in the design of structures is their response to extreme winds. This is especially true in regions affected by hurricanes. In this research, gust factors derived from hurricane wind-speed records are compared with those derived by Durst and others from open-scale records obtained in well-developed, extratropical storms. Based on records obtained from four hurricanes and 11 different recording stations, it is concluded that an upward adjustment of the Durst gust factors for the estimation of hurricane gust speeds may be in order. Anomalously high gust factors observed for hurricane winds in inland areas suggest the need for additional study. Also, it is concluded that a reexamination of the statistics of gust factors obtained from extratropical storm data would be useful in clearly identifying the appropriate probability distribution function. RP KRAYER, WR (reprint author), NATL INST STAND & TECHNOL,DIV STRUCT,BLDG & FIRE RES LAB,GAITHERSBURG,MD, USA. NR 8 TC 69 Z9 76 U1 2 U2 4 PU AMER METEOROLOGICAL SOC PI BOSTON PA 45 BEACON ST, BOSTON, MA 02108-3693 SN 0003-0007 J9 B AM METEOROL SOC JI Bull. Amer. Meteorol. Soc. PD MAY PY 1992 VL 73 IS 5 BP 613 EP 617 DI 10.1175/1520-0477(1992)073<0613:GFATHW>2.0.CO;2 PG 5 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA HU545 UT WOS:A1992HU54500005 ER PT J AU GONSKI, R AF GONSKI, R TI SCHOOL WEATHER NETWORK - A COOPERATIVE EFFORT SO BULLETIN OF THE AMERICAN METEOROLOGICAL SOCIETY LA English DT Editorial Material RP GONSKI, R (reprint author), NOAA,NATL WEATHER SERV,RALEIGH,NC, USA. NR 0 TC 2 Z9 2 U1 0 U2 0 PU AMER METEOROLOGICAL SOC PI BOSTON PA 45 BEACON ST, BOSTON, MA 02108-3693 SN 0003-0007 J9 B AM METEOROL SOC JI Bull. Amer. Meteorol. Soc. PD MAY PY 1992 VL 73 IS 5 BP 628 EP 630 PG 3 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA HU545 UT WOS:A1992HU54500007 ER PT J AU KOPE, RG AF KOPE, RG TI OPTIMAL HARVEST RATES FOR MIXED STOCKS OF NATURAL AND HATCHERY FISH SO CANADIAN JOURNAL OF FISHERIES AND AQUATIC SCIENCES LA English DT Article ID SALMON AB Optimal harvest rates were computed using dynamic programming for mixed-stock fisheries exploiting two stocks of either natural or hatchery origin. Natural stocks were described by a Ricker spawner-recruit relationship and hatchery stocks were described by a rectilinear spawner-recruit relationship. Harvest rates were optimized for both risk-neutral and risk-averse utility functions. For two natural stocks with low productivities, optimal harvest rates generally appeared to favor the stronger stock for a risk-neutral utility function and the weaker stock for a risk-averse utility function. For both utility functions, optimal harvest policy became less sensitive to relative stock strength as the productivity of the stocks increased. When at least one of the stocks was of hatchery origin, optimal harvest policy favored the weaker stock using either utility function. RP KOPE, RG (reprint author), SW FISHERIES SCI CTR,NATL MARINE FISHERIES SERV,TIBURON LAB,3150 PARADISE DR,TIBURON,CA 94920, USA. NR 15 TC 9 Z9 9 U1 0 U2 1 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 1992 VL 49 IS 5 BP 931 EP 938 DI 10.1139/f92-103 PG 8 WC Fisheries; Marine & Freshwater Biology SC Fisheries; Marine & Freshwater Biology GA HT328 UT WOS:A1992HT32800009 ER PT J AU KOVAL, CA HOWARD, JN AF KOVAL, CA HOWARD, JN TI ELECTRON-TRANSFER AT SEMICONDUCTOR ELECTRODE LIQUID ELECTROLYTE INTERFACES SO CHEMICAL REVIEWS LA English DT Review ID SCANNING TUNNELING MICROSCOPY; SOLAR-ENERGY CONVERSION; MODULATED PHOTOCURRENT SPECTROSCOPY; MATCHED SUPERLATTICE ELECTRODES; HOLE VERTICAL TRANSPORT; INDUCED SURFACE-STATES; PARA-INDIUM PHOSPHIDE; BAND POTENTIAL SHIFT; GROUP METAL CATALYST; SPACE-CHARGE FIELDS C1 UNIV COLORADO, NOAA, COOPERAT INST RES ENVIRONM SCI, BOULDER, CO 80309 USA. RP UNIV COLORADO, DEPT CHEM & BIOCHEM, BOULDER, CO 80309 USA. NR 286 TC 140 Z9 144 U1 2 U2 47 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 0009-2665 EI 1520-6890 J9 CHEM REV JI Chem. Rev. PD MAY PY 1992 VL 92 IS 3 BP 411 EP 433 DI 10.1021/cr00011a004 PG 23 WC Chemistry, Multidisciplinary SC Chemistry GA HV169 UT WOS:A1992HV16900005 ER PT J AU MOSSNER, S SPRAKER, TR BECKER, PR BALLSCHMITER, K AF MOSSNER, S SPRAKER, TR BECKER, PR BALLSCHMITER, K TI RATIOS OF ENANTIOMERS OF ALPHA-HCH AND DETERMINATION OF ALPHA-HCH, BETA-HCH, AND GAMMA-HCH ISOMERS IN BRAIN AND OTHER TISSUES OF NEONATAL NORTHERN FUR SEALS (CALLORHINUS-URSINUS) SO CHEMOSPHERE LA English DT Article DE NEONATAL NORTHERN FUR SEALS; BRAIN TISSUE; HCH ISOMERS; ENANTIOMERIC RATIO; ISOMER RATIO; CAPILLARY GAS CHROMATOGRAPHY ID STENELLA-COERULEOALBA; STRIPED DOLPHIN; ORGANOCHLORINE AB The ratios of the two enantiomers of alpha-HCH have been determined by high resolution gas chromatography using different chiral stationary phases of the cyclodextrin-type in brain, blubber, liver, and lung tissues of neonatal Northern fur seals of different health status. The ratio of the two enantiomers (+)-alpha-HCH / (-)-alpha-HCH (tentatively assigned) varied from 1.8 to 28 in blubber and brain, respectively. Northern fur seal milk and cod liver oil were analyzed for comparison. In addition, the concentrations of alpha-, beta-, and gamma-HCH isomers in the fur seal samples were determined. The three isomers (alpha-, beta-, and gamma-HCH) gave a tissue specific distribution with a rather constant alpha-HCH / gamma-HCH ratio of 4 +/- 2. Only the brain tissue gave an alpha-HCH / gamma-HCH ratio of 36 +/- 1. C1 COLORADO STATE UNIV,COLL VET MED & BIOMED SCI,FT COLLINS,CO 80523. NOAA,OFF OCEAN RESOURCES CONSERVAT & ASSESSMENT,ARCTIC ENVIRONM ASSESSMENT CTR,ANCHORAGE,AK 99508. RP MOSSNER, S (reprint author), UNIV ULM,DEPT ANALYT & ENVIRONM CHEM,ALBERT EINSTEIN ALLEE 11,W-7900 ULM,GERMANY. NR 16 TC 52 Z9 54 U1 2 U2 4 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD, ENGLAND OX5 1GB SN 0045-6535 J9 CHEMOSPHERE JI Chemosphere PD MAY PY 1992 VL 24 IS 9 BP 1171 EP 1180 DI 10.1016/0045-6535(92)90044-R PG 10 WC Environmental Sciences SC Environmental Sciences & Ecology GA HX057 UT WOS:A1992HX05700002 ER PT J AU ALBUS, JS AF ALBUS, JS TI RCS - A REFERENCE MODEL ARCHITECTURE FOR INTELLIGENT CONTROL SO COMPUTER LA English DT Article RP ALBUS, JS (reprint author), NATL INST STAND & TECHNOL,GAITHERSBURG,MD 20899, USA. NR 5 TC 12 Z9 12 U1 2 U2 4 PU IEEE COMPUTER SOC PI LOS ALAMITOS PA 10662 LOS VAQUEROS CIRCLE, PO BOX 3014, LOS ALAMITOS, CA 90720-1264 SN 0018-9162 J9 COMPUTER JI Computer PD MAY PY 1992 VL 25 IS 5 BP 56 EP 59 DI 10.1109/2.144396 PG 4 WC Computer Science, Hardware & Architecture; Computer Science, Software Engineering SC Computer Science GA HT317 UT WOS:A1992HT31700006 ER PT J AU DAVIS, W JONES, A SALEH, A AF DAVIS, W JONES, A SALEH, A TI GENERIC ARCHITECTURE FOR INTELLIGENT CONTROL-SYSTEMS SO COMPUTER INTEGRATED MANUFACTURING SYSTEMS LA English DT Article DE INTELLIGENT CONTROLLER; GENERIC ARCHITECTURE; COMPUTER-INTEGRATED MANUFACTURING AB In this paper we describe a generic architecture for an intelligent controller which can be used at any level within a shopfloor control hierarchy for a computer-integrated manufacturing system. For each assigned job, this controller decides which proces plan will be used and the start and finish times for all the tasks in that plan. In addition, the controller monitors its subordinates' execution of those tasks and recovers from reported errors. We describe the functions that each controller performs, with additional discussion on the frequencies at which those functions are performed. C1 NATL INST STANDARDS & TECHNOL,GAITHERSBURG,MD 20899. AT&T BELL LABS,HOLMDEL,NJ 07733. RP DAVIS, W (reprint author), UNIV ILLINOIS,URBANA,IL 61801, USA. NR 16 TC 6 Z9 6 U1 0 U2 2 PU BUTTERWORTH-HEINEMANN LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD, OXON, ENGLAND OX5 1GB SN 0951-5240 J9 COMPUT INTEGR MANUF JI Comput. Integr. Manuf. Syst. PD MAY PY 1992 VL 5 IS 2 BP 105 EP 113 DI 10.1016/0951-5240(92)90005-W PG 9 WC Computer Science, Interdisciplinary Applications; Engineering, Manufacturing; Operations Research & Management Science SC Computer Science; Engineering; Operations Research & Management Science GA JH693 UT WOS:A1992JH69300004 ER PT J AU CHUANG, JC WISE, SA CAO, S MUMFORD, JL AF CHUANG, JC WISE, SA CAO, S MUMFORD, JL TI CHEMICAL CHARACTERIZATION OF MUTAGENIC FRACTIONS OF PARTICLES FROM INDOOR COAL COMBUSTION - A STUDY OF LUNG-CANCER IN XUAN-WEI, CHINA SO ENVIRONMENTAL SCIENCE & TECHNOLOGY LA English DT Article ID POLYCYCLIC AROMATIC-HYDROCARBONS; AIR PARTICULATE MATTER; EMISSIONS AB In the rural Xuan Wei County, Yunnan Province, lung cancer mortality rates for women are among the highest in China. Most of these women are nonsmokers, and studies have shown that lung cancer in Xuan Wei is associated with domestic use of smoky coal under unvented conditions. The objective of this study is to determine the chemical constituents that may be linked to the high lung cancer rates in Xuan Wei using the bioassay-directed fractionation method. Ten high-volume filter samples ( < 10 Am) collected from the home inhabited by a person with lung cancer during cooking periods on four consecutive days were subjected to Soxhlet extraction. This composite sample extract was fractionated on a normal-phase column into seven fractions. The second fraction was the most active in the bioassay, containing mainly polycyclic aromatic hydrocarbon (PAH) and alkylated PAH. The two polar fractions 6 and 7 were the next most active. The most active PAH fraction was further separated into 11 subfractions, based on the number of aromatic carbons. The results indicated that the presence of three to four-ring alkylated PAHs in the sample extract is a significant factor that may be linked to the high incidence of lung cancer in Xuan Wei, China. C1 NATL INST STAND & TECHNOL,DIV ORGAN ANALYT RES,GAITHERSBURG,MD 20899. INST ENVIRONM HLTH & ENGN,BEIJING,PEOPLES R CHINA. US EPA,HLTH EFFECTS RES LAB,RES TRIANGLE PK,NC 27711. RP CHUANG, JC (reprint author), BATTELLE COLUMBUS OPERAT,ATMOSPHER SCI & APPL TECHNOL,COLUMBUS,OH 43201, USA. NR 16 TC 38 Z9 42 U1 0 U2 5 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 SN 0013-936X J9 ENVIRON SCI TECHNOL JI Environ. Sci. Technol. PD MAY PY 1992 VL 26 IS 5 BP 999 EP 1004 DI 10.1021/es00029a020 PG 6 WC Engineering, Environmental; Environmental Sciences SC Engineering; Environmental Sciences & Ecology GA HR623 UT WOS:A1992HR62300030 ER PT J AU LO, NCH HUNTER, JR MOSER, HG SMITH, PE METHOT, RD AF LO, NCH HUNTER, JR MOSER, HG SMITH, PE METHOT, RD TI THE DAILY FECUNDITY REDUCTION METHOD - A NEW PROCEDURE FOR ESTIMATING ADULT FISH BIOMASS SO ICES JOURNAL OF MARINE SCIENCE LA English DT Article DE BIOMASS; EGGS; ICHTHYOPLANKTON; FECUNDITY; MICROSTOMUS-PACIFICUS C1 ALASKA FISHERIES SCI CTR,SEATTLE,WA 98115. RP LO, NCH (reprint author), NATL MARINE FISHERIES SERV,SW FISHERIES SCI CTR,POB 271,LA JOLLA,CA 92038, USA. NR 15 TC 28 Z9 28 U1 0 U2 4 PU ACADEMIC PRESS LTD PI LONDON PA 24-28 OVAL RD, LONDON, ENGLAND NW1 7DX SN 1054-3139 J9 ICES J MAR SCI JI ICES J. Mar. Sci. PD MAY PY 1992 VL 49 IS 2 BP 209 EP 215 DI 10.1093/icesjms/49.2.209 PG 7 WC Fisheries; Marine & Freshwater Biology; Oceanography SC Fisheries; Marine & Freshwater Biology; Oceanography GA HX096 UT WOS:A1992HX09600009 ER PT J AU MATROSOV, SY AF MATROSOV, SY TI RADAR REFLECTIVITY IN SNOWFALL SO IEEE TRANSACTIONS ON GEOSCIENCE AND REMOTE SENSING LA English DT Article ID SIZE SPECTRA; SCATTERING AB Backscattering properties of dry snowflakes at different microwave frequencies are examined. It is shown that the Rayleigh approximation does not often provide the necessary accuracy for snowflake reflectivity calculations for radar wavelengths used in meteorology; however, another simple approximation, the Rayleigh-Gans approximation, can be safely used for such calculations. Reflectivity-snowfall rate relationships are derived for different snow densities and different radar frequencies. It is shown that dual-wavelength radar measurements can be used for estimating the effective sizes of snowflakes. Experimental data obtained during radar snowfall measurements in the WISP project of 1991 with the NOAA X- and Ka-band radars are found to be consistent with the described theoretical results. RP MATROSOV, SY (reprint author), UNIV COLORADO,NOAA,COOPERAT INST RES ENVIRONM SCI,WAVE PROPAGAT LAB,BOULDER,CO 80309, USA. NR 22 TC 65 Z9 65 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 0196-2892 J9 IEEE T GEOSCI REMOTE JI IEEE Trans. Geosci. Remote Sensing PD MAY PY 1992 VL 30 IS 3 BP 454 EP 461 DI 10.1109/36.142923 PG 8 WC Geochemistry & Geophysics; Engineering, Electrical & Electronic; Remote Sensing; Imaging Science & Photographic Technology SC Geochemistry & Geophysics; Engineering; Remote Sensing; Imaging Science & Photographic Technology GA JA318 UT WOS:A1992JA31800004 ER PT J AU WALTER, SJ BENDER, PL AF WALTER, SJ BENDER, PL TI THE SLANT PATH ATMOSPHERIC REFRACTION CALIBRATOR - AN INSTRUMENT TO MEASURE THE MICROWAVE PROPAGATION DELAYS INDUCED BY ATMOSPHERIC WATER-VAPOR SO IEEE TRANSACTIONS ON GEOSCIENCE AND REMOTE SENSING LA English DT Article AB The Slant Path Atmospheric Refraction Calibrator, SPARC, has been developed to measure the water vapor induced propagation delay experienced by a radio signal traversing the atmosphere. SPARC measures the difference in the travel times between an optical and a microwave signal propagating along the same atmospheric path. Since the refractivity of dry air is similar for both the microwave and optical signals, the difference in arrival times is a sensitive measure of the water vapor induced microwave delay. The instrument is capable of measuring the difference in the optical and microwave travel times with an accuracy of 15 ps or better. SPARC was developed to provide an accurate, independent method for evaluating other techniques used to determine the atmospheric water vapor induced delay. The theoretical and experimental issues involved in making measurements of the delay induced by water vapor will be discussed. Measurements along a 13.35-km ground-based path will be presented which will illustrate the instrument's stability, precision, and accuracy. C1 NATL INST STAND & TECHNOL,JOINT INST LAB ASTROPHYS,BOULDER,CO 80309. UNIV COLORADO,BOULDER,CO 80309. NATL INST STAND & TECHNOL,DIV QUANTUM PHYS,BOULDER,CO. RP WALTER, SJ (reprint author), JET PROP LAB,MICROWAVE OBSERVAT SYST SECT,PASADENA,CA 91109, USA. NR 15 TC 1 Z9 1 U1 0 U2 0 PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017-2394 SN 0196-2892 J9 IEEE T GEOSCI REMOTE JI IEEE Trans. Geosci. Remote Sensing PD MAY PY 1992 VL 30 IS 3 BP 462 EP 471 DI 10.1109/36.142924 PG 10 WC Geochemistry & Geophysics; Engineering, Electrical & Electronic; Remote Sensing; Imaging Science & Photographic Technology SC Geochemistry & Geophysics; Engineering; Remote Sensing; Imaging Science & Photographic Technology GA JA318 UT WOS:A1992JA31800005 ER PT J AU DUTTON, EG AF DUTTON, EG TI A COHERENCE BETWEEN THE QBO AND THE AMPLITUDE OF THE MAUNA-LOA ATMOSPHERIC TRANSMISSION ANNUAL CYCLE SO INTERNATIONAL JOURNAL OF CLIMATOLOGY LA English DT Article DE ATMOSPHERIC SOLAR TRANSMISSION; BACKGROUND AEROSOLS; QBO ID QUASI-BIENNIAL OSCILLATION; 11-YEAR SOLAR-CYCLE; STRATOSPHERE; AEROSOLS; WINTER; OZONE; PHASE AB The transmission of direct solar radiation through the atmosphere above Mauna Loa, Hawaii, is shown to have a quasi-biennial cyclic component that is coherent with the well-known tropical stratospheric quasi-biennial oscillation (QBO). The QBO-related signal in the 32-year transmission record is manifested as an oscillation in the amplitude of the annual cycle. The transmission annual cycle is known to be caused by seasonal transport of Asian continental dust to and over the island of Hawaii. Variations in water vapour and ozone are eliminated as possible influences in the transmission-QBO relationship, leaving aerosols as the source of the oscillation. The ultimate cause for the quasi-biennial signal in the transmission record is unknown. Small but cyclic modifications to the tropospheric energy budget occur as a result of the transmission variations. The magnitude of the energy budget variations are less than those typically expected to have a significant climatic impact. RP DUTTON, EG (reprint author), NOAA,CLIMATE MONITORING & DIAGNOST LAB,BOULDER,CO 80303, USA. NR 26 TC 13 Z9 13 U1 0 U2 0 PU JOHN WILEY & SONS LTD PI W SUSSEX PA BAFFINS LANE CHICHESTER, W SUSSEX, ENGLAND PO19 1UD SN 0899-8418 J9 INT J CLIMATOL JI Int. J. Climatol. PD MAY-JUN PY 1992 VL 12 IS 4 BP 383 EP 396 DI 10.1002/joc.3370120406 PG 14 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA JA379 UT WOS:A1992JA37900005 ER PT J AU NELSON, PP GLASER, SD AF NELSON, PP GLASER, SD TI ACOUSTIC EMISSIONS PRODUCED BY DISCRETE FRACTURE IN ROCK .1. SOURCE LOCATION AND ORIENTATION EFFECTS SO INTERNATIONAL JOURNAL OF ROCK MECHANICS AND MINING SCIENCES LA English DT Article AB An experimental programme was undertaken to develop a servo-controlled loading and high-fidelity data acquisition system to investigate acoustic emission (AE) waveforms produced during discrete fracture propagation in rock. Large (0.3 x 0.3 x 1 m) chevron-notched specimens were loaded in controlled conditions, and characteristic acoustic emissions associated with Mode I and Mode II fracture were isolated Two different rocks, granite and dolostone, were tested. Only the initial segment of each AE waveform was used for analysis, ensuring an analysis free from effects of sample size and shape, with propagation effectively through an infinite half-space. High-fidelity, NIST-type, piezoelectric displacement transducers were built and used The entire experimental system was calibrated, and the system inverse filter was applied to recorded signals. The system had little effect on the recorded signals and deconvolution was not necessary for these tests. The effects of AE source position and orientation relative to the transducer were studied. A reproducible step impulse source was used Changes in source orientation were found to result in two types of waveform from a common source-a step-like waveform which changes to a ramp-like waveform when the source was directed with a large angle to the surface being monitored. The effects of source position were small. C1 NATL INST STAND & TECHNOL, BLDG & FIRE RES LAB, GAITHERSBURG, MD 20899 USA. RP UNIV TEXAS, DEPT CIVIL ENGN, AUSTIN, TX 78712 USA. NR 33 TC 6 Z9 7 U1 0 U2 1 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLAND SN 1365-1609 EI 1873-4545 J9 INT J ROCK MECH MIN JI Int. J. Rock Mech. Min. Sci. PD MAY PY 1992 VL 29 IS 3 BP 237 EP 251 DI 10.1016/0148-9062(92)93658-7 PG 15 WC Engineering, Geological; Mining & Mineral Processing SC Engineering; Mining & Mineral Processing GA HZ066 UT WOS:A1992HZ06600004 ER PT J AU GLASER, SD NELSON, PP AF GLASER, SD NELSON, PP TI ACOUSTIC EMISSIONS PRODUCED BY DISCRETE FRACTURE IN ROCK .2. KINEMATICS OF CRACK-GROWTH DURING CONTROLLED MODE-I AND MODE-II LOADING OF ROCK SO INTERNATIONAL JOURNAL OF ROCK MECHANICS AND MINING SCIENCES LA English DT Article AB A well-characterized experimental programme was undertaken to study acoustic emission (AE) waveforms produced during discrete fracture propagation in rock. Large chevron-notched specimens were loaded in controlled conditions, and characteristic AE associated with Mode I and II fracture were isolated. Tested rock included medium-grained granite and micritic dolostone. The AE waveforms belonged to five characteristic classes. The variety of AE event classes was the same in Mode I and II loadings for both rock types. By far the most common three classes are related to basic step impulses. The mechanism for crack propagation in rock is indicated to be due to localized tensile failure for both tensile and shear loadings. Relative roughness of the crack surface corresponded closely with relative distributions of the different characteristic event classes. A ratio of event types was formulated which is a good indicator of the amount of out-of-plane crack growth. Rates of occurrence of AE events varied during loading modes, and between the two materials. Very few events occurred during load increase to peak or during unloading. Event rates increased as the crack propagated through the notch, and AE rates for subsequent constant-length crack propagation were constant. C1 UNIV TEXAS, DEPT CIVIL ENGN, AUSTIN, TX 78712 USA. RP NATL INST STAND & TECHNOL, BLDG & FIRE RES LAB, GAITHERSBURG, MD 20899 USA. NR 8 TC 9 Z9 9 U1 0 U2 1 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLAND SN 1365-1609 EI 1873-4545 J9 INT J ROCK MECH MIN JI Int. J. Rock Mech. Min. Sci. PD MAY PY 1992 VL 29 IS 3 BP 253 EP 265 DI 10.1016/0148-9062(92)93659-8 PG 13 WC Engineering, Geological; Mining & Mineral Processing SC Engineering; Mining & Mineral Processing GA HZ066 UT WOS:A1992HZ06600005 ER PT J AU ELLERBE, P TAI, SSC CHRISTENSEN, RG ESPINOSALENIZ, R PAULE, RC SANDER, LC SNIEGOSKI, LT WELCH, MJ WHITE, E AF ELLERBE, P TAI, SSC CHRISTENSEN, RG ESPINOSALENIZ, R PAULE, RC SANDER, LC SNIEGOSKI, LT WELCH, MJ WHITE, E TI THE CERTIFICATION OF COCAINE AND BENZOYLECGONINE IN A HUMAN URINE STANDARD REFERENCE MATERIAL SO JOURNAL OF ANALYTICAL TOXICOLOGY LA English DT Article C1 NATL INST STAND & TECHNOL,DIV ORGAN ANALYT RES,GAITHERSBURG,MD 20899. RP ELLERBE, P (reprint author), COLL AMER PATHOLOGISTS,NORTHFIELD,IL 60093, USA. NR 5 TC 12 Z9 12 U1 0 U2 0 PU PRESTON PUBLICATIONS INC PI NILES PA 7800 MERRIMAC AVE PO BOX 48312, NILES, IL 60648 SN 0146-4760 J9 J ANAL TOXICOL JI J. Anal. Toxicol. PD MAY-JUN PY 1992 VL 16 IS 3 BP 158 EP 162 PG 5 WC Chemistry, Analytical; Toxicology SC Chemistry; Toxicology GA HW175 UT WOS:A1992HW17500004 PM 1522707 ER PT J AU BYRD, GD PAULE, RC SANDER, LC SNIEGOSKI, LT WHITE, E BAUSUM, HT AF BYRD, GD PAULE, RC SANDER, LC SNIEGOSKI, LT WHITE, E BAUSUM, HT TI DETERMINATION OF 3-QUINUCLIDINYL BENZILATE (QNB) AND ITS MAJOR METABOLITES IN URINE BY ISOTOPE-DILUTION GAS-CHROMATOGRAPHY MASS-SPECTROMETRY SO JOURNAL OF ANALYTICAL TOXICOLOGY LA English DT Article C1 NATL INST STAND & TECHNOL,CTR ANALYT CHEM,GAITHERSBURG,MD 20899. USA,BIOMED RES & DEV LAB,FREDERICK,MD 21702. NR 12 TC 3 Z9 3 U1 4 U2 7 PU PRESTON PUBLICATIONS INC PI NILES PA 7800 MERRIMAC AVE PO BOX 48312, NILES, IL 60648 SN 0146-4760 J9 J ANAL TOXICOL JI J. Anal. Toxicol. PD MAY-JUN PY 1992 VL 16 IS 3 BP 182 EP 187 PG 6 WC Chemistry, Analytical; Toxicology SC Chemistry; Toxicology GA HW175 UT WOS:A1992HW17500011 PM 1522714 ER PT J AU JOSEPH, JD ACKMAN, RG AF JOSEPH, JD ACKMAN, RG TI CAPILLARY COLUMN GAS-CHROMATOGRAPHIC METHOD FOR ANALYSIS OF ENCAPSULATED FISH OILS AND FISH OIL ETHYL-ESTERS - COLLABORATIVE STUDY SO JOURNAL OF AOAC INTERNATIONAL LA English DT Article ID LIPIDS; EICOSAPENTAENOATE; DOCOSAHEXAENOATE; AUTOXIDATION; PRODUCTS AB A gas chromatographic (GC) method using a capillary column for analysis of encapsulated fish oils and ethyl esters was studied collaboratively in 21 laboratories. Each collaborator analyzed 6 soft-gelatin encapsulated samples; 5 were triacylglycerol oils (one was a blind duplicate), and one was an ethyl ester concentrate of omega-3 (n-3) polyunsaturates. Constituent fatty acids of the oils were converted to methyl esters by base-catalyzed transesterification of the oils; any free acids in the oils were esterified by subsequent reaction with BF3/CH3OH. The ethyl ester concentrate required no further derivatization. Results were reported as area percentages of 24 analytes of nutritional or biochemical interest. In addition, weights (mg/g sample) of EPA (all-cis-5,8,11,14,17-eicosapentaenoic acid or 20:5n-3) and DHA (all-cis-4,7,10,13,16,19-docosahexaenoic acid or 22:6n-3) were determined through the use of the internal standards, respectively, methyl tricosanoate (23:0) and ethyl 23:0, for the methyl and ethyl esters. The only instrumentation specifically required was a flexible fused silica capillary GC column coated with a bonded polyglycol such as Carbowax-20M, an oxygen scrubber installed in the carrier gas supply line, and a flame ionization detector (FID). Most of the collaborators experienced little difficulty in applying the method, and, of 2526 values reported, only 4.3% were identified as outlier values. The reproducibility relative standard deviations (RSD(R)) compared favorably in most instances with, or were substantially better than, those of 2 earlier collaborative studies of fish oils. Because the variances were homogeneous, standard deviations and relative standard deviations determined on the area percent analyses of the blind duplicate oils were pooled to give the following mean values: s(r) 0.15, RSD(r) = 4.88%, s(R) = 0.41, and RSD(R) = 12.91%. Analytes that rarely occur at greater than 0.5% in marine oils (22:0, 22:4n-6, 22:5n-6, 24:0, and 24:1) were not included in these calculations. The method was adopted first action by AOAC international as an American Oil Chemists' Society (AOCS)-AOAC method. RP JOSEPH, JD (reprint author), US DEPT COMMERCE,NATL OCEAN & ATMOSPHER ADM,NATL MARINE FISHERIES SERV,CHARLESTON LAB,POB 12607,CHARLESTON,SC 29422, USA. NR 31 TC 185 Z9 197 U1 1 U2 24 PU AOAC INTERNATIONAL PI GAITHERSBURG PA 481 NORTH FREDRICK AVE, STE 500, GAITHERSBURG, MD 20877-2504 SN 1060-3271 J9 J AOAC INT JI J. AOAC Int. PD MAY-JUN PY 1992 VL 75 IS 3 BP 488 EP 506 PG 19 WC Chemistry, Analytical; Food Science & Technology SC Chemistry; Food Science & Technology GA HW428 UT WOS:A1992HW42800015 ER PT J AU MATEER, CL DELUISI, JJ AF MATEER, CL DELUISI, JJ TI A NEW UMKEHR INVERSION ALGORITHM SO JOURNAL OF ATMOSPHERIC AND TERRESTRIAL PHYSICS LA English DT Article AB In this paper, we describe a new Umkehr algorithm for the estimation of the vertical ozone profile from observations of the Umkehr effect of Gotz. The algorithm uses new ozone absorption coefficients. which result in a change in the scale of measurement, and their temperature dependence. Better e priori ozone profiles are possible because of the very large increase in the archive of ozone profile measurements. The characterization of the retrieved ozone profiles and the error analysis follow the recipe of Rodgers. The differences between the new algorithm and the old 1964 algorithm are discussed. For both algorithms, only the retrievals for layers 4-8 (19-43 km) are suitable for use in ozone trend analysis. For these layers, the retrieval resolution is trivially improved over that in the 1964 algorithm. For other layers, the retrievals either respond mainly to real ozone changes in adjacent or distant layers, or are a function of low-amplitude changes over a very broad range of layers. The effect of atmospheric aerosol on the retrieved profiles has been determined, and found to be generally similar to the effect for the old algorithm, but differing in some details. C1 NOAA,WASHINGTON,DC 20230. NR 27 TC 49 Z9 52 U1 0 U2 1 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 1992 VL 54 IS 5 BP 537 EP 556 DI 10.1016/0021-9169(92)90095-3 PG 20 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA HY123 UT WOS:A1992HY12300005 ER PT J AU LONDON, J LIU, SC AF LONDON, J LIU, SC TI LONG-TERM TROPOSPHERIC AND LOWER STRATOSPHERIC OZONE VARIATIONS FROM OZONESONDE OBSERVATIONS SO JOURNAL OF ATMOSPHERIC AND TERRESTRIAL PHYSICS LA English DT Article ID CLIMATE; TRANSPORT; TROPICS; IMPACT; LAYER AB An analysis is presented of the long-term mean pressure-latitude seasonal distribution of tropospheric and lower stratospheric ozone for the four seasons covering, in par-t, over 20 years of ozonesonde data. The observed patterns show minimum ozone mixing ratios in the equatorial and tropical troposphere except in regions where net photochemical production is dominant. In the middle and upper troposphere, and low stratosphere to 50 mb, ozone increases from the tropics to subpolar latitudes of both hemispheres. In mid stratosphere, the ozone mixing ratio is a maximum over the tropics. The observed vertical ozone gradient is small in the troposphere but increases rapidly above the tropopause. The seasonal variation at a typical mid latitude station (Hohenpeissenberg) shows a summer maximum in the low to middle troposphere, shifting to a winter-spring maximum in the upper troposphere and lower stratosphere and spring-summer maximum at 10 mb. The amplitude of the annual variation increases from a minimum in the tropics to a maximum in polar regions. Also, the amplitude increases with height at all latitudes up to about 30 mb where the phase of the annual variation changes abruptly. The phase of the annual variation is during spring in the boundary layer, summer in mid troposphere, and spring in the upper troposphere and lower stratosphere. The annual long-term ozone trends are significantly positive at about + 1.2% yr-1 in mid troposphere (500 mb) and significantly negative at about -0.6% yr-1 in the lower stratosphere (50 mb). C1 NOAA,AERON LAB,BOULDER,CO 80303. RP LONDON, J (reprint author), UNIV COLORADO,DEPT ASTROPHYS PLANETARY & ATMOSPHER SCI,BOULDER,CO 80309, USA. NR 99 TC 35 Z9 35 U1 4 U2 6 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 1992 VL 54 IS 5 BP 599 EP 625 DI 10.1016/0021-9169(92)90100-Y PG 27 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA HY123 UT WOS:A1992HY12300010 ER PT J AU MONACO, ME LOWRY, TA EMMETT, RL AF MONACO, ME LOWRY, TA EMMETT, RL TI ASSEMBLAGES OF UNITED-STATES WEST-COAST ESTUARIES BASED ON THE DISTRIBUTION OF FISHES SO JOURNAL OF BIOGEOGRAPHY LA English DT Article DE ESTUARIES; ESTUARINE FISHES; PRINCIPAL COMPONENT ANALYSIS; STEPWISE MULTIPLE REGRESSION ANALYSIS; UNITED-STATES WEST COAST, ESTUARINE HABITAT AB Principal component analysis (PCA) was conducted on a data matrix representing presence or absence of 360 adult and juvenile fish species in twenty-eight estuaries ranging from Puget Sound, WA to Tijuana, CA. The data matrix included published and unpublished information for each species/estuary combination and consultation with local fishery experts on specific estuaries. The PCA identified six estuarine components that explained 72% of the variation in the data: (1) Northern Riverine Group; (2) Southern California Group; (3) Northern Estuarine Group; (4) Central Marine Group; (5) Fjord Group, and (6) Coastal Northwest Group. Species assemblages for each estuarine group were identified and used as surrogate habitat indicators to compare and contrast groups of estuaries. Stepwise multiple regressions of estuarine physical characteristics identified estuary mouth depth and area of the seawater zone as significant predictors of the number of fish species per estuary. These estuarine physical parameters appear to influence access and diversity of estuarine habitats and ultimately the number of fish species occurring within an estuary. C1 NATL MARINE FISHERIES SERV,NW FISHERIES SCI CTR,DIV COASTAL ZONE & ESTUARINE STUDIES,HAMMOND,OR 97121. RP MONACO, ME (reprint author), NOAA,DIV STATEG ENVIRONM ASSESSMENTS,ROCKVILLE,MD 20852, USA. NR 10 TC 34 Z9 40 U1 2 U2 8 PU BLACKWELL SCIENCE LTD PI OXFORD PA OSNEY MEAD, OXFORD, OXON, ENGLAND OX2 0EL SN 0305-0270 J9 J BIOGEOGR JI J. Biogeogr. PD MAY PY 1992 VL 19 IS 3 BP 251 EP 267 DI 10.2307/2845450 PG 17 WC Ecology; Geography, Physical SC Environmental Sciences & Ecology; Physical Geography GA JJ755 UT WOS:A1992JJ75500003 ER PT J AU ASTUMIAN, RD ROBERTSON, B LI, RS ROSS, J AF ASTUMIAN, RD ROBERTSON, B LI, RS ROSS, J TI QUADRATIC RESPONSE OF A CHEMICAL-REACTION TO EXTERNAL OSCILLATIONS SO JOURNAL OF CHEMICAL PHYSICS LA English DT Article ID ELECTRIC-FIELD; THERMODYNAMIC EFFICIENCY; FREE-ENERGY; CORRELATION SPECTROSCOPY; THERMAL ENGINE; STEADY-STATES; DISSIPATION; FLUCTUATIONS; SYSTEMS; ENZYME AB We develop a second-order response theory to investigate the effects of external periodic perturbations on a chemical reaction at a stable steady state in an open reactor. We apply the theory to the quadratic Schlogl model, a single-variable nonlinear reaction. In the presence of oscillating reactant or product concentrations or oscillating rate coefficients, the average intermediate concentration, the fluxes, and the dissipation are each a Lorentzian function of frequency with midpoint at the inverse relaxation time of the system. Thus even very short relaxation times can be determined by measuring average rates as a function of frequency of the perturbation. The amplitude of the Lorentzian depends on the chemical mechanism of the reaction and is proportional to the square of the amplitude of the applied perturbation. We also show that energy from the perturbation can be used to drive the reaction in a direction opposite of that predicted by the Gibb's free energy difference of reactants and products, even under circumstances where the overall affinity is independent of the perturbation. C1 STANFORD UNIV,DEPT CHEM,STANFORD,CA 94305. RP ASTUMIAN, RD (reprint author), DEPT COMMERCE,TECHNOL ADM,NATL INST STAND & TECHNOL,DIV BIOTECHNOL,GAITHERSBURG,MD 20899, USA. NR 50 TC 15 Z9 15 U1 1 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 MAY 1 PY 1992 VL 96 IS 9 BP 6536 EP 6542 DI 10.1063/1.462592 PG 7 WC Chemistry, Physical; Physics, Atomic, Molecular & Chemical SC Chemistry; Physics GA HR467 UT WOS:A1992HR46700022 ER PT J AU TCHANGBRILLET, WUL JULIENNE, PS ROBBE, JM LETZELTER, C ROSTAS, F AF TCHANGBRILLET, WUL JULIENNE, PS ROBBE, JM LETZELTER, C ROSTAS, F TI A MODEL OF THE B1-SIGMA+-D'1-SIGMA+ RYDBERG-VALENCE PREDISSOCIATING INTERACTION IN THE CO MOLECULE SO JOURNAL OF CHEMICAL PHYSICS LA English DT Article ID INTERSTELLAR CO; CROSS-SECTIONS; DIPOLE-MOMENTS; 115 NM; PHOTODISSOCIATION; STATES; TRANSITION; ABSORPTION AB The strong interaction between the B 3s-sigma (1)SIGMA+ Rydberg state and the D' (1)SIGMA+ valence state of the CO molecule is shown to cause large changes in the vibrational and rotational constants of the B state, as well as predissociation of all rotational levels of B (upsilon' = 2) and a breaking off in the emission of B (upsilon' = 1) levels at J = 36 in C-12 O-16 and J = 37 in C-13 O-16. A two-state diabatic model of the Rydberg-valence interaction is constructed and vibrational term values, widths, and intensities are calculated by close coupling in order to account for the strong mixing. The model separates the differences between the spectroscopic constants of the B state and those of the ground state molecular ion into two components, one due to the R-dependent quantum defect of the B state and another due to the strong Rydberg-valence perturbation. The perturbation is characterized by a constant coupling matrix element of 2900 cm-1 inside the crossing point of the two diabatic potentials, decaying to zero at long internuclear distances. Basically good agreement is found between the model and experiment for shifts in vibrational and rotational terms and for predissociation widths and relative band intensities. The second breaking off in emission in the B (upsilon' = 1) rotational series is used to estimate the height of the long-range barrier maximum in the D' (1)SIGMA+ state to be about 1048 +/- 19 cm-1 above the ground state dissociation limit. Comparison of predicted widths from the two channel close coupled model with those from a single channel adiabatic model shows differences on the order of a factor of 2. C1 OBSERV PARIS,CNRS,URA 812,F-92195 MEUDON,FRANCE. NATL INST STAND & TECHNOL,DIV MOLEC PHYS,GAITHERSBURG,MD 20899. UNIV LILLE FLANDRE ARTOIS,UFR PHYS,SPECT MOLEC LAB,CNRS,UA 770,F-59655 VILLENEUVE DASCQ,FRANCE. RP TCHANGBRILLET, WUL (reprint author), OBSERV PARIS,DEPT ATOMES & MOLEC ASTROPHYS,F-92195 MEUDON,FRANCE. RI Julienne, Paul/E-9378-2012 OI Julienne, Paul/0000-0002-5494-1442 NR 24 TC 55 Z9 55 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 MAY 1 PY 1992 VL 96 IS 9 BP 6735 EP 6745 DI 10.1063/1.462561 PG 11 WC Chemistry, Physical; Physics, Atomic, Molecular & Chemical SC Chemistry; Physics GA HR467 UT WOS:A1992HR46700041 ER PT J AU FAN, YB SOLIN, SA KIM, H PINNAVAIA, TJ NEUMANN, DA AF FAN, YB SOLIN, SA KIM, H PINNAVAIA, TJ NEUMANN, DA TI ELASTIC AND INELASTIC NEUTRON-SCATTERING STUDY OF HYDROGENATED AND DEUTERATED TRIMETHYLAMMONIUM PILLARED VERMICULITE CLAYS SO JOURNAL OF CHEMICAL PHYSICS LA English DT Article ID PHASE-TRANSITIONS; H-1-NMR; MOTIONS AB Neutron scattering has been used to study the basal spacing and vibrational excitations of oriented samples of (CH3)3NH+-vermiculite and its deuterated form (CD3)3ND+-vermiculite. Both forms exhibit a basal spacing of 12.71 angstrom and a rich vibrational spectrum in the energy range 20-140 meV for Q perpendicular and parallel to the c-axis. These results are compared with infrared measurements and inelastic neutron scattering results of trimethylammonium halides over the same energy range. The torsional mode of the methyl group has been found to be split by approximately 8 meV due to the top-top interaction between the methyl groups in the trimethylammonium vermiculite. C1 MICHIGAN STATE UNIV, DEPT PHYS, E LANSING, MI 48824 USA. MICHIGAN STATE UNIV, CTR FUNDAMENTAL MAT RES, E LANSING, MI 48824 USA. NEC CORP LTD, RES INST, PRINCETON, NJ 08540 USA. NATL INST STAND & TECHNOL, MAT SCI & ENGN LAB, GAITHERSBURG, MD 20899 USA. NR 21 TC 7 Z9 7 U1 0 U2 1 PU AMER INST PHYSICS PI MELVILLE PA 1305 WALT WHITMAN RD, STE 300, MELVILLE, NY 11747-4501 USA SN 0021-9606 EI 1089-7690 J9 J CHEM PHYS JI J. Chem. Phys. PD MAY 1 PY 1992 VL 96 IS 9 BP 7064 EP 7071 DI 10.1063/1.462538 PG 8 WC Chemistry, Physical; Physics, Atomic, Molecular & Chemical SC Chemistry; Physics GA HR467 UT WOS:A1992HR46700079 ER PT J AU LOVEJOY, CM GOLDFARB, L LEONE, SR AF LOVEJOY, CM GOLDFARB, L LEONE, SR TI PREFERENTIAL INPLANE ROTATIONAL-EXCITATION OF H2O (001) BY TRANSLATIONAL-TO-VIBRATIONAL TRANSFER FROM 2.2-EV H-ATOMS SO JOURNAL OF CHEMICAL PHYSICS LA English DT Note ID ANGULAR-MOMENTUM; MOLECULAR-BEAM; WATER-VAPOR; ALIGNMENT; ORIENTATION; SCATTERING; RELAXATION; DYNAMICS C1 UNIV COLORADO,DEPT CHEM & BIOCHEM,BOULDER,CO 80309. RP LOVEJOY, CM (reprint author), NATL INST STAND & TECHNOL,JOINT INST LAB ASTROPHYS,BOULDER,CO 80309, USA. NR 27 TC 26 Z9 26 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 MAY 1 PY 1992 VL 96 IS 9 BP 7180 EP 7182 DI 10.1063/1.462531 PG 3 WC Chemistry, Physical; Physics, Atomic, Molecular & Chemical SC Chemistry; Physics GA HR467 UT WOS:A1992HR46700095 ER PT J AU STEVENS, BG DONALDSON, WE HAAGA, JA AF STEVENS, BG DONALDSON, WE HAAGA, JA TI 1ST OBSERVATIONS OF PODDING BEHAVIOR FOR THE PACIFIC LYRE CRAB HYAS-LYRATUS (DECAPODA, MAJIDAE) SO JOURNAL OF CRUSTACEAN BIOLOGY LA English DT Article AB This paper reports the first observations of podding behavior (aggregation) for the Pacific lyre crab Hyas lyratus near Kodiak Island, Alaska. Pods containing approximately 2,000 crabs of both sexes were observed on 2 separate occasions during dives in the 2-person submersible Delta in April 1991. The pods appeared to be mating aggregations. The pods occurred in an average depth of 115 m. C1 ALASKA DEPT FISH & GAME,KODIAK,AK 99615. RP STEVENS, BG (reprint author), NATL MARINE FISHERIES SERV,POB 1638,KODIAK,AK 99615, USA. NR 8 TC 16 Z9 16 U1 0 U2 1 PU CRUSTACEAN SOC PI SAN ANTONIO PA 840 EAST MULBERRY, SAN ANTONIO, TX 78212 SN 0278-0372 J9 J CRUSTACEAN BIOL JI J. Crustac. Biol. PD MAY PY 1992 VL 12 IS 2 BP 193 EP 195 DI 10.2307/1549074 PG 3 WC Marine & Freshwater Biology SC Marine & Freshwater Biology GA HT686 UT WOS:A1992HT68600006 ER PT J AU LIN, AN SHENTON, HW AF LIN, AN SHENTON, HW TI SEISMIC PERFORMANCE OF FIXED-BASE AND BASE-ISOLATED STEEL FRAMES SO JOURNAL OF ENGINEERING MECHANICS-ASCE LA English DT Article AB The seismic performance of fixed-base and base-isolated concentrically braced and special moment-resisting steel frames are determined. The fixed-base frames are designed in accordance with the 1990 Structural Engineers Association of California (SEAOC) Recommended Lateral Force Requirements and Commentary, while the base-isolated frames are designed to 100%, 50%, and 25% of the SEAOC-recommended lateral force levels. Nonlinear time-history analyses, for 54 ground motion records, are then conducted. The number of yielded or collapsed frames, number of yielded elements, total and relative roof displacement, and isolation-bearing displacement are statistically evaluated. Comparable or better performance is achieved for the base-isolated braced frame designed to 50% of the SEAOC-recommended lateral force. Comparable performance is achieved for the base-isolated moment frame at various design force levels, depending on the performance criteria. RP LIN, AN (reprint author), NATL INST STAND & TECH,BLDG & FIRE RES LAB,GAITHERSBURG,MD 20899, USA. NR 18 TC 8 Z9 8 U1 1 U2 3 PU ASCE-AMER SOC CIVIL ENGINEERS PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017-2398 SN 0733-9399 J9 J ENG MECH-ASCE JI J. Eng. Mech.-ASCE PD MAY PY 1992 VL 118 IS 5 BP 921 EP 941 DI 10.1061/(ASCE)0733-9399(1992)118:5(921) PG 21 WC Engineering, Mechanical SC Engineering GA HP998 UT WOS:A1992HP99800005 ER PT J AU LEWIS, EJ MCLAUGHLIN, SM BODAMMER, JE SAWYER, TK AF LEWIS, EJ MCLAUGHLIN, SM BODAMMER, JE SAWYER, TK TI EPITHELIOCYSTIS IN 10 NEW HOST SPECIES OF MARINE FISH SO JOURNAL OF FISH DISEASES LA English DT Note ID BASS MORONE-SAXATILIS; DEVELOPMENTAL CYCLE; DISEASE C1 NATL MARINE FISHERIES SERV,NARRAGANSETT LAB,NARRAGANSETT,RI. RESCON ASSOCIATES INC,ROYAL OAK,MD. RP LEWIS, EJ (reprint author), NATL MARINE FISHERIES SERV,COOPERAT OXFORD LAB,904 S MORRIS ST,OXFORD,MD 21654, USA. NR 13 TC 21 Z9 21 U1 0 U2 1 PU BLACKWELL SCIENCE LTD PI OXFORD PA OSNEY MEAD, OXFORD, OXON, ENGLAND OX2 0EL SN 0140-7775 J9 J FISH DIS JI J. Fish Dis. PD MAY PY 1992 VL 15 IS 3 BP 267 EP 271 DI 10.1111/j.1365-2761.1992.tb00663.x PG 5 WC Fisheries; Marine & Freshwater Biology; Veterinary Sciences SC Fisheries; Marine & Freshwater Biology; Veterinary Sciences GA HY561 UT WOS:A1992HY56100006 ER PT J AU TATARSKII, VI DUBOVIKOV, MM PRASKOVSKY, AA KARYAKIN, MY AF TATARSKII, VI DUBOVIKOV, MM PRASKOVSKY, AA KARYAKIN, MY TI TEMPERATURE-FLUCTUATION SPECTRUM IN THE DISSIPATION RANGE FOR STATISTICALLY ISOTROPIC TURBULENT-FLOW SO JOURNAL OF FLUID MECHANICS LA English DT Article ID OPTICAL PROPAGATION; LAYER AB In the present paper we obtain a theoretical expression for the temperature fluctuation spectrum for a Prandtl number of approximately one and for the region where both viscosity and molecular heat conductivity are important. An asymptotic theory for very large wavenumbers of the temperature spectrum in the turbulent flow is developed. The assumption of smallness of the correlation coefficient between the product of small-scale components of velocities at two points and the corresponding product of small-scale components of temperatures is used. The results of simultaneous measurements of streamwise velocity fluctuations and temperature fluctuations carried out in the plane of symmetry of a two-dimensional wake behind a slightly heated cylinder (R(lambda) = 270) in a wind tunnel is consistent with this assumption. The main result of the theory developed is the appearance of a bump in the temperature spectrum for a Prandtl number of approximately one. C1 MOSCOW CENT AEROHYDRODYNAM INST,MOSCOW 140160,USSR. NOAA,ERL,WPL,BOULDER,CO 80303. RP TATARSKII, VI (reprint author), PN LEBEDEV PHYS INST,MOSCOW,USSR. NR 31 TC 11 Z9 11 U1 0 U2 2 PU CAMBRIDGE UNIV PRESS PI NEW YORK PA 40 WEST 20TH STREET, NEW YORK, NY 10011-4211 SN 0022-1120 J9 J FLUID MECH JI J. Fluid Mech. PD MAY PY 1992 VL 238 BP 683 EP 698 DI 10.1017/S0022112092001861 PG 16 WC Mechanics; Physics, Fluids & Plasmas SC Mechanics; Physics GA HX224 UT WOS:A1992HX22400026 ER PT J AU FIDDLER, W PENSABENE, JW GATES, RA HALE, M JAHNCKE, M AF FIDDLER, W PENSABENE, JW GATES, RA HALE, M JAHNCKE, M TI N-NITROSODIMETHYLAMINE FORMATION IN COOKED FRANKFURTERS CONTAINING ALASKA POLLOCK (THERAGRA-CHALCOGRAMMA) MINCE AND SURIMI SO JOURNAL OF FOOD SCIENCE LA English DT Article DE NITROSAMINES; SURIMI; FRANKFURTERS; NITRITE; FISH ID VOLATILE NITROSAMINES; BACON; FOODS; FISH; DIMETHYLNITROSAMINE; NITROSOPYRROLIDINE; TRIMETHYLAMINE; DIMETHYLAMINE; NITRITE; COOKING AB Studies were conducted to determine the feasibility of using Alaska pollock mince as a partial substitute for red meats in the formulation of frankfurters. Studies included the effects of fish form (unwashed and washed mince and surimi), percentage substitution (15 and 50) and five different methods of cooking the fish-meat franks on their N-nitrosodimethylamine (NDMA) content. The amount of formed NDMA depended on the method of cooking. Broiling and frying generated the highest levels. Microwave and boiling generated the lowest levels of NDMA, which were equivalent to the level in uncooked franks. Broiling was observed to increase the amount of dimethyl- and trimethylamine formed. C1 US DEPT COMMERCE,NOAA,NATL MARINE FISHERIES SERV,SEFC,CHARLESTON,SC 29412. RP FIDDLER, W (reprint author), USDA ARS,EASTERN REG RES CTR,600 E MERMAID LANE,PHILADELPHIA,PA 19118, USA. NR 36 TC 9 Z9 10 U1 1 U2 2 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 1992 VL 57 IS 3 BP 569 EP & DI 10.1111/j.1365-2621.1992.tb08044.x PG 0 WC Food Science & Technology SC Food Science & Technology GA HX829 UT WOS:A1992HX82900008 ER PT J AU OLSON, DA AF OLSON, DA TI HEAT-TRANSFER IN THIN, COMPACT HEAT-EXCHANGERS WITH CIRCULAR, RECTANGULAR, OR PIN-FIN FLOW PASSAGES SO JOURNAL OF HEAT TRANSFER-TRANSACTIONS OF THE ASME LA English DT Article DE AUGMENTATION AND ENHANCEMENT; FORCED CONVECTION; HEAT EXCHANGERS AB We have measured heat transfer and pressure drop of three thin, compact heat exchangers in helium gas at 3.5 MPa and higher, with Reynolds numbers of 450 to 36,000. The flow geometries for the three heat exchanger specimens were: circular tube, rectangular channel, and staggered pin fin with tapered pins. The specimens were heated radiatively at heat fluxes up to 77 W/cm2. Correlations were developed for the isothermal friction factor as a function of Reynolds number, and for the Nusselt number as a function of Reynolds number and the ratio of wall temperature to fluid temperature. The specimen with the pin fin internal geometry had significantly better heat transfer than the other specimens, but it also had higher pressure drop. For certain conditions of helium flow and heating, the temperature more than doubled from the inlet to the outlet of the specimens, producing large changes in gas velocity, density, viscosity, and thermal conductivity. These changes in properties did not affect the correlations for friction factor and Nusselt number in turbulent flow. RP OLSON, DA (reprint author), NATL INST STAND & TECHNOL,DIV CHEM ENGN,BOULDER,CO 80303, USA. NR 14 TC 11 Z9 11 U1 0 U2 1 PU ASME-AMER SOC MECHANICAL ENG PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 SN 0022-1481 J9 J HEAT TRANS-T ASME JI J. Heat Transf.-Trans. ASME PD MAY PY 1992 VL 114 IS 2 BP 373 EP 382 DI 10.1115/1.2911285 PG 10 WC Thermodynamics; Engineering, Mechanical SC Thermodynamics; Engineering GA HW623 UT WOS:A1992HW62300011 ER PT J AU KUSHIDA, G BAUM, HR KASHIWAGI, T DIBLASI, C AF KUSHIDA, G BAUM, HR KASHIWAGI, T DIBLASI, C TI HEAT AND MASS-TRANSPORT FROM THERMALLY DEGRADING THIN CELLULOSIC MATERIALS IN A MICROGRAVITY ENVIRONMENT SO JOURNAL OF HEAT TRANSFER-TRANSACTIONS OF THE ASME LA English DT Article ID IGNITION; MODEL; ABSORPTION; RADIATION; FUEL AB A theoretical model describing the behavior of a thermally thin cellulosic sheet heated by external thermal radiation in a quiescent microgravity environment is developed. This model describes thermal and oxidative degradation of the sheet and the heat and mass transfer of evolved degradation products from the heated cellulosic surface into the gas phase. At present, gas phase oxidation reactions are not included. Without buoyancy, the dominant vorticity creation mechanism in the bulk of the gas is absent except at the material surface by the requirement of the no-slip condition. The no-slip condition is relaxed, permitting the flow to be represented by a velocity potential. This approximation is permissible due to the combination of a microgravity environment and low Reynolds number associated with slow small-area heating by external radiation. Two calculations are carried out: heating without thermal degradation, and heating with thermal degradation of the sheet with endothermic pyrolysis, exothermic thermal oxidative degradation, and highly exothermic char oxidation. The results show that pyrolysis is the main degradation reaction. Moreover, self-sustained propagation of smoldering for cellulosic materials is very difficult due to the lack of sufficient oxygen supply in a quiescent environment. C1 NAPLES UNIV,DEPT CHEM ENGN,I-80138 NAPLES,ITALY. RP KUSHIDA, G (reprint author), NATL INST STAND & TECHNOL,CTR FIRE RES,GAITHERSBURG,MD 20899, USA. NR 13 TC 5 Z9 5 U1 0 U2 0 PU ASME-AMER SOC MECHANICAL ENG PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 SN 0022-1481 J9 J HEAT TRANS-T ASME JI J. Heat Transf.-Trans. ASME PD MAY PY 1992 VL 114 IS 2 BP 494 EP 502 DI 10.1115/1.2911300 PG 9 WC Thermodynamics; Engineering, Mechanical SC Thermodynamics; Engineering GA HW623 UT WOS:A1992HW62300026 ER PT J AU PLIVA, J MERDES, DW PINE, AS AF PLIVA, J MERDES, DW PINE, AS TI PARALLEL BANDS OF CYCLOPROPANE IN THE 3.2-MU-M REGION SO JOURNAL OF MOLECULAR SPECTROSCOPY LA English DT Article ID FOURIER-TRANSFORM; SPECTRA; SPECTROSCOPY; FUNDAMENTALS; NU-11 C1 NATL INST STAND & TECHNOL,DIV MOLEC PHYS,GAITHERSBURG,MD 20899. RP PLIVA, J (reprint author), PENN STATE UNIV,DEPT PHYS,UNIV PK,PA 16802, USA. NR 21 TC 3 Z9 3 U1 0 U2 0 PU ACADEMIC PRESS INC JNL-COMP SUBSCRIPTIONS PI SAN DIEGO PA 525 B ST, STE 1900, SAN DIEGO, CA 92101-4495 SN 0022-2852 J9 J MOL SPECTROSC JI J. Mol. Spectrosc. PD MAY-JUN PY 1992 VL 153 IS 1-2 BP 133 EP 144 DI 10.1016/0022-2852(92)90464-Y PG 12 WC Physics, Atomic, Molecular & Chemical; Spectroscopy SC Physics; Spectroscopy GA HT478 UT WOS:A1992HT47800013 ER PT J AU OHASHI, N HOUGEN, JT AF OHASHI, N HOUGEN, JT TI TUNNELING SPLITTINGS IN A-BX4-TYPE VANDERWAALS MOLECULES SO JOURNAL OF MOLECULAR SPECTROSCOPY LA English DT Article ID WATER DIMER; ROTATIONAL SPECTRUM; COMPLEX C1 NATL INST STAND & TECHNOL,DIV MOLEC PHYS,GAITHERSBURG,MD 20899. RP OHASHI, N (reprint author), KANAZAWA UNIV,FAC SCI,DEPT PHYS,KANAZAWA,ISHIKAWA 920,JAPAN. NR 15 TC 5 Z9 5 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 MAY-JUN PY 1992 VL 153 IS 1-2 BP 429 EP 446 DI 10.1016/0022-2852(92)90487-9 PG 18 WC Physics, Atomic, Molecular & Chemical; Spectroscopy SC Physics; Spectroscopy GA HT478 UT WOS:A1992HT47800036 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 AND 1ST TORSIONAL STATES OF ACETALDEHYDE SO JOURNAL OF MOLECULAR SPECTROSCOPY LA English DT Article ID MILLIMETER-WAVE SPECTRUM; ADDITIONAL MEASUREMENTS; METHANOL; MICROWAVE; ROTATION C1 NATL INST STAND & TECHNOL,DIV MOLEC PHYS,GAITHERSBURG,MD 20899. UNIV LIBRE BRUXELLES,CHIM PHYS MOLEC LAB,B-1050 BRUSSELS,BELGIUM. NR 12 TC 47 Z9 47 U1 0 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 MAY-JUN PY 1992 VL 153 IS 1-2 BP 578 EP 586 DI 10.1016/0022-2852(92)90494-9 PG 9 WC Physics, Atomic, Molecular & Chemical; Spectroscopy SC Physics; Spectroscopy GA HT478 UT WOS:A1992HT47800043 ER PT J AU FORNEY, D JACOX, ME THOMPSON, WE AF FORNEY, D JACOX, ME THOMPSON, WE TI THE VIBRATIONAL-SPECTRA OF MOLECULAR-IONS ISOLATED IN SOLID NEON - HCCH+ AND HCC- .8. SO JOURNAL OF MOLECULAR SPECTROSCOPY LA English DT Article ID ELECTRON-SPIN-RESONANCE; PHOTOELECTRON-SPECTROSCOPY; CATION RADICALS; ACETYLENE; C-2; TRANSITION; VINYLIDENE; ATTACHMENT; THRESHOLD; ENERGIES RP FORNEY, D (reprint author), NATL INST STAND & TECHNOL,DIV MOLEC PHYS,GAITHERSBURG,MD 20899, USA. NR 40 TC 27 Z9 27 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-JUN PY 1992 VL 153 IS 1-2 BP 680 EP 691 DI 10.1016/0022-2852(92)90502-F PG 12 WC Physics, Atomic, Molecular & Chemical; Spectroscopy SC Physics; Spectroscopy GA HT478 UT WOS:A1992HT47800051 ER PT J AU PRESSER, C GUPTA, AK AVEDISIAN, CT SEMERJIAN, HG AF PRESSER, C GUPTA, AK AVEDISIAN, CT SEMERJIAN, HG TI COMBUSTION OF METHANOL AND METHANOL DODECANOL SPRAY FLAMES SO JOURNAL OF PROPULSION AND POWER LA English DT Article; Proceedings Paper CT 26TH JOINT PROPULSION CONF CY JUL 10-18, 1990 CL ORLANDO, FL SP AMER INST AERONAUT & ASTRONAUT, SOC AUTOMOT ENGINEERS, AMER SOC MECH ENGINEERS, AMER SOC ENGN EDUC ID FUEL AB The structure of methanol and methanol/dodecanol mixture spray flames has been examined. The mixture was studied in order to obtain evidence for the occurrence of microexplosions. Droplet size and velocity measurements were carried out under burning conditions using phase/Doppler interferometry. Laser sheet beam photography was used to observe the global features of the spray within the nonluminous portion of the flames. Droplet size and velocity distributions near the nozzle exit were found to be similar and monomodal for both fuels. Further downstream in the mixture flame, the velocity distribution became bimodal near the spray boundary along with a change in size distribution to smaller droplets and an increase in number density. These results suggest that microexplosions occur in 50150 mixtures of methanol/dodecanol spray flames. C1 UNIV MARYLAND,DEPT MECH ENGN,COLLEGE PK,MD 20742. CORNELL UNIV,SIBLEY SCH MECH & AEROSP ENGN,ITHACA,NY 14853. NATL INST STAND & TECHNOL,DIV MEASUREMENTS,CHEM SCI & TECHNOL LAB,GAITHERSBURG,MD 20899. RP PRESSER, C (reprint author), NATL INST STAND & TECHNOL,CHEM SCI & TECHNOL LAB,HIGH TEMP PROC GRP,GAITHERSBURG,MD 20899, USA. NR 8 TC 10 Z9 11 U1 0 U2 1 PU AMER INST AERONAUT ASTRONAUT PI RESTON PA 1801 ALEXANDER BELL DRIVE, STE 500, RESTON, VA 22091 SN 0748-4658 J9 J PROPUL POWER JI J. Propul. Power PD MAY-JUN PY 1992 VL 8 IS 3 BP 553 EP 559 DI 10.2514/3.23513 PG 7 WC Engineering, Aerospace SC Engineering GA HU330 UT WOS:A1992HU33000005 ER PT J AU UKELES, R WIKFORS, GH FERRIS, GE AF UKELES, R WIKFORS, GH FERRIS, GE TI FACTORS AFFECTING THE SALINITY TOLERANCE OF THE FRESH-WATER CRYPTOMONAD CHILOMONAS-PARAMECIUM SO JOURNAL OF PROTOZOOLOGY LA English DT Article DE PH; PHOSPHATE ID CRASSOSTREA-VIRGINICA; CHEMICAL-COMPOSITION; TRANSPORT; GROWTH AB The capacity of the freshwater cryptomonad Chilomonas paramecium to develop a tolerance for seawater in the growth medium was investigated as part of a research program exploring potential microbial food sources for estuarine bivalve mollusks. By gradually increasing the percentage of estuarine seawater included in a freshwater culture medium over the course of 10 years, strains were obtained that tolerate from 16 to 32% seawater (highest salinity 10.5 ppt), achieving equivalent final densities with similar gross biochemical composition. However, after subculture in seawater-containing media for over 20 years, growth rates in more-saline media remained appreciably slower than in low-salinity media. Reduction of C paramecium growth rate by seawater was found to be exacerbated in media with an initial pH of 3.5 as compared with pH 4.0-5.0, suggesting either a specific H+ effect upon metabolism of the medium carbon source (lactic acid) or a general cation effect upon nutrient uptake or cell metabolism. By contrast, depression of growth rates at high salinity was ameliorated by eliminating sodium-phosphate enrichments in growth media. This suggests that cations in the phosphate salt were contributing to cation-mediated growth inhibition. Results indicate a potential for C paramecium, cultured in moderately saline media with no phosphate enrichments, to be used as a carbohydrate supplement for laboratory and hatchery feeding of estuarine bivalve mollusks. C1 NOAA,NATL MARINE FISHERIES SERV,NE FISHERIES CTR,MILFORD LAB,MILFORD,CT 06460. NR 33 TC 2 Z9 2 U1 1 U2 2 PU SOC PROTOZOOLOGISTS PI LAWRENCE PA 810 E 10TH ST, LAWRENCE, KS 66044 SN 0022-3921 J9 J PROTOZOOL PD MAY-JUN PY 1992 VL 39 IS 3 BP 399 EP 405 DI 10.1111/j.1550-7408.1992.tb01470.x PG 7 WC Zoology SC Zoology GA HW631 UT WOS:A1992HW63100007 ER PT J AU THOMAS, DB ZALEWSKI, EF AF THOMAS, DB ZALEWSKI, EF TI A RADIOMETER FOR PRECISION COHERENT RADIATION MEASUREMENTS SO JOURNAL OF RESEARCH OF THE NATIONAL INSTITUTE OF STANDARDS AND TECHNOLOGY LA English DT Article DE COHERENT RADIATION; LASER; PHOTOCURRENT; RADIOMETER; SILICON PHOTODIODE ID RESPONSE SELF-CALIBRATION; QUANTUM EFFICIENCY; SILICON AB A radiometer has been designed for precision coherent radiation measurements and tested for long-term repeatability at wavelengths of 488 and 633 nm. The radiometer consists of a pn silicon photodiode maintained in a nitrogen atmosphere with a quartz window designed to eliminate interference problems. Ratio measurements between the radiometer and an absolute type detector were made over a period of 215 d. At 0.5 mW, the standard deviations were 0.008% and 0.009% at 488 and 633 nm, respectively. The maximum deviations from the mean were 0.016% and 0.015% at the respective wavelengths. Measurements were also made on the radiometer with respect to angular and spatial uniformity and linearity. The high precision, simplicity, and portability of the radiometer suggest it for use as a transfer standard for radiometric measurements. RP THOMAS, DB (reprint author), NATL INST STAND & TECHNOL, CTR RADIAT RES, DIV RADIOMETRIC PHYS, GAITHERSBURG, MD 20899 USA. NR 11 TC 1 Z9 1 U1 1 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 1992 VL 97 IS 3 BP 327 EP 334 DI 10.6028/jres.097.012 PG 8 WC Instruments & Instrumentation; Physics, Applied SC Instruments & Instrumentation; Physics GA JE875 UT WOS:A1992JE87500001 PM 28053435 ER PT J AU JONES, FE HARRIS, GL AF JONES, FE HARRIS, GL TI ITS-90 DENSITY OF WATER FORMULATION FOR VOLUMETRIC STANDARDS CALIBRATION SO JOURNAL OF RESEARCH OF THE NATIONAL INSTITUTE OF STANDARDS AND TECHNOLOGY LA English DT Article DE AIR-SATURATED WATER; CALIBRATION; DENSITY OF WATER; ISOTHERMAL COMPRESSIBILITY; ITS-90; VOLUMETRIC STANDARDS AB A new formulation of the density of air-saturated water as a function of temperature on the 1990 International Temperature Scale (ITS-90) is presented. Also, a new equation for calculating isothermal compressibility as a function of temperature on ITS-90 was developed. The equations are to be used to calculate the density of water, in the temperature range 5 to 40-degrees-C on ITS-90, used in the gravimetric determination of the volume of volumetric standards. C1 NATL INST STAND & TECHNOL, OFF WEIGHTS & MEASURES, GAITHERSBURG, MD 20899 USA. NR 4 TC 16 Z9 16 U1 0 U2 5 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 1992 VL 97 IS 3 BP 335 EP 340 DI 10.6028/jres.097.013 PG 6 WC Instruments & Instrumentation; Physics, Applied SC Instruments & Instrumentation; Physics GA JE875 UT WOS:A1992JE87500002 PM 28053436 ER PT J AU CHANG, SS WEEKS, JJ AF CHANG, SS WEEKS, JJ TI HEAT-CAPACITY AND THERMODYNAMIC PROPERTIES OF POLY(CHLOROTRIFLUOROETHYLENE) FROM 2.5 TO 620-K SO JOURNAL OF RESEARCH OF THE NATIONAL INSTITUTE OF STANDARDS AND TECHNOLOGY LA English DT Article DE AUTOMATED ADIABATIC CALORIMETRY; CRYSTALLITE DISTRIBUTION; DIFFERENTIAL SCANNING CALORIMETRY; GLASS TRANSITION; HEAT CAPACITY; POLY(CHLOROTRIFLUOROETHYLENE); RESIDUAL ENTROPY; THERMODYNAMIC PROPERTIES ID TERPHENYL; CRYSTAL; LIQUID; GLASS AB Heat capacities and thermodynamic properties of a number of poly(chlorotrifluoroethylene) samples subjected to various thermal treatments, to achieve crystallinities ranging from approximately 10 to 90%, have been studied from 2.5 to 370 K by automated adiabatic calorimetry and from 250 to 620 K by differential scanning calorimetry. Small heat capacity discontinuities in the temperature range from 320 to 350 K were observed in all samples with crystallinities greater than 40%. Spontaneous adiabatic temperature drifts associated with these anomalies were positive (exothermic) for quenched samples and negative (endothermic) for annealed samples. Therefore these anomalies were believed to be associated with a relaxation phenomenon similar to that of a glass transition. For highly quenched low crystallinity films, a much larger heat capacity discontinuity of greater than 15% was observed, amidst a crystallization exotherm. In addition to the above phenomena, annealing of the sample at any temperature between 240 to 400 K would produce a shift in the population distribution of crystallites from reorganization or melting and recrystallization. As a result, the apparent heat capacity became somewhat lowered at the annealing temperature and somewhat raised at about 20 K above the annealing temperature. RP CHANG, SS (reprint author), NATL INST STAND & TECHNOL, DIV POLYMERS, GAITHERSBURG, MD 20899 USA. NR 45 TC 3 Z9 3 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 1992 VL 97 IS 3 BP 341 EP 363 DI 10.6028/jres.097.014 PG 23 WC Instruments & Instrumentation; Physics, Applied SC Instruments & Instrumentation; Physics GA JE875 UT WOS:A1992JE87500003 PM 28053437 ER PT J AU BABICIVANCIC, V FUREDIMILHOFER, H BRNICEVIC, N MARKOVIC, M AF BABICIVANCIC, V FUREDIMILHOFER, H BRNICEVIC, N MARKOVIC, M TI PRECIPITATION AND SOLUBILITY OF CALCIUM HYDROGENURATE HEXAHYDRATE SO JOURNAL OF RESEARCH OF THE NATIONAL INSTITUTE OF STANDARDS AND TECHNOLOGY LA English DT Article DE CALCIUM HYDROGENURATE HEXAHYDRATE; IDENTIFICATION; PRECIPITATION; SOLUBILITY; SOLUBILITY PRODUCT; URINARY STONE FORMATION ID URIC-ACID; MONOSODIUM URATE; OXALATE; DIAGRAMS; SYSTEM AB Solid phases formed in the quaternary system: uric acid - calcium hydroxide - hydrochloric acid - water aged for 2 months at 310 K were studied to determine conditions for calcium hydrogenurate hexahydrate, Ca(C5H3N4O3)2.6H2O, precipitation. The precipitates were identified by chemical and thermogravimetric analyses, x-ray powder diffraction, infrared spectroscopy, light microscopy, and scanning electron microscopy. In the precipitation diagram the concentration region in which calcium hydrogenurate hexahydrate precipitated as a single solid phase was established. The solubility of calcium hydrogenurate hexahydrate was investigated in the pH range from 6.2 to 10.1 at different temperatures. The total soluble and ionic concentration of calcium (atomic absorption spectroscopy and Ca-selective electrode), total urate concentration (spectrophotometry), and pH were determined in equilibrated solutions. The data are presented in the form of tables and chemical potential diagrams. By using these data the thermodynamic solubility products of calcium hydrogenurate hexahydrate, K(s) = a(Ca2+).a2(C5H3N4O3-), were determined: pK(s) = 10.12 +/- 0.07 at 288 K, pK(s) = 9.81 +/- 0.09 at 298 K, pK(s) = 9.28 +/- 0.04 at 310 K, and pK(s) = 9.01 +/- 0.03 at 318 K. The formation of calcium hydrogenurate hexahydrate crystals in urinary tract of patients with pathologically high concentrations of calcium and urates (hypercalciuria and hyperuricosiuria) is possible. C1 RUDJER BOSKOVIC INST, DEPT PHYS CHEM, POB 1016, YU-41001 ZAGREB, YUGOSLAVIA. UNIV ZAGREB, FAC SCI, YU-41001 ZAGREB, YUGOSLAVIA. NATL INST STAND & TECHNOL, AMER DENT ASSOC, HLTH FDN, GAITHERSBURG, MD 20899 USA. NR 27 TC 9 Z9 9 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 1992 VL 97 IS 3 BP 365 EP 372 DI 10.6028/jres.097.015 PG 8 WC Instruments & Instrumentation; Physics, Applied SC Instruments & Instrumentation; Physics GA JE875 UT WOS:A1992JE87500004 PM 28053438 ER PT J AU ALBUS, J BOSTELMAN, R DAGALAKIS, N AF ALBUS, J BOSTELMAN, R DAGALAKIS, N TI THE NIST SPIDER, A ROBOT CRANE SO JOURNAL OF RESEARCH OF THE NATIONAL INSTITUTE OF STANDARDS AND TECHNOLOGY LA English DT Article DE CABLES; KINEMATICALLY CONSTRAINED; PARALLEL LINK MANIPULATOR; ROBOT CRANES; 6 DEGREES OF FREEDOM; 6 METER MODEL; STEWART PLATFORM; WORK PLATFORM AB The Robot Systems Division of the National Institute of Standards and Technology has been experimenting for several years with new concepts for robot cranes. These concepts utilize the basic idea of the Stewart Platform parallel link manipulator. The unique feature of the NIST approach is to use cables as the parallel links and to use winches as the actuators. So long as the cables are all in tension, the load is kinematically constrained, and the cables resist perturbing forces and moments with equal stiffness to both positive and negative loads. The result is that the suspended load is constrained with a mechanical stiffness determined by the elasticity of the cables, the suspended weight, and the geometry of the mechanism. Based on these concepts, a revolutionary new type of robot crane, the NIST SPIDER (Stewart Platform Instrumented Drive Environmental Robot) has been developed that can control the position, velocity, and force of tools and heavy machinery in all six degrees of freedom (x, y, z, roll, pitch, and yaw). Depending on what is suspended from its work platform, the SPIDER can perform a variety of tasks. Examples are: cutting, excavating and grading, shaping and finishing, lifting and positioning. A 6 m version of the SPIDER has been built and critical performance characteristics analyzed. RP ALBUS, J (reprint author), NATL INST STAND & TECHNOL, DIV ROBOT SYST, MFG ENGN LAB, GAITHERSBURG, MD 20899 USA. NR 6 TC 58 Z9 58 U1 0 U2 7 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 1992 VL 97 IS 3 BP 373 EP 385 DI 10.6028/jres.097.016 PG 13 WC Instruments & Instrumentation; Physics, Applied SC Instruments & Instrumentation; Physics GA JE875 UT WOS:A1992JE87500005 PM 28053439 ER PT J AU FELDMAN, A BEETZ, CP DRORY, M HOLLY, S AF FELDMAN, A BEETZ, CP DRORY, M HOLLY, S TI WORKSHOP ON CHARACTERIZING DIAMOND FILMS - GAITHERSBURG, MD - FEBRUARY 27-28, 1992 SO JOURNAL OF RESEARCH OF THE NATIONAL INSTITUTE OF STANDARDS AND TECHNOLOGY LA English DT Editorial Material C1 ADV TECHNOL MAT, DANBURY, CT 06810 USA. CRYSTALLUME, MENLO PK, CA 94025 USA. ROCKWELL INT CORP, CANOGA PK, CA 91304 USA. RP FELDMAN, A (reprint author), NATL INST STAND & TECHNOL, GAITHERSBURG, MD 20899 USA. NR 2 TC 0 Z9 0 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 1992 VL 97 IS 3 BP 387 EP 391 DI 10.6028/jres.097.017 PG 5 WC Instruments & Instrumentation; Physics, Applied SC Instruments & Instrumentation; Physics GA JE875 UT WOS:A1992JE87500006 PM 28053440 ER PT J AU HAGWOOD, C AF HAGWOOD, C TI THE CALIBRATION-PROBLEM AS AN ILL-POSED INVERSE PROBLEM SO JOURNAL OF STATISTICAL PLANNING AND INFERENCE LA English DT Article DE CALIBRATION PROBLEM; ILL-POSED PROBLEM; INVERSE PROBLEM ID LINEAR CALIBRATION; REGRESSION AB Let (x(i), y(i)), i = 1, 2,..., n, be data used for developing the calibration curve, y = alpha + beta-x. Classically, given a future y' the associated x' is estimated by inverting the calibration line, which gives thc estimate x' = (y' - alpha)/beta. This estimate has the deficiency of having an infinite variance. In this paper we use the techniques for solving an ill-posed inverse problem to develop a family of solutions x'lambda = (beta/(lambda + beta-2)(y' - alpha), lambda > 0 with finite variance. Out of this family we find one that outperforms x'. C1 NATL INST STAND & TECHNOL,DIV STAT ENGN,GAITHERSBURG,MD 20899. NR 21 TC 3 Z9 3 U1 0 U2 0 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0378-3758 J9 J STAT PLAN INFER JI J. Stat. Plan. Infer. PD MAY PY 1992 VL 31 IS 2 BP 179 EP 185 DI 10.1016/0378-3758(92)90028-Q PG 7 WC Statistics & Probability SC Mathematics GA HY061 UT WOS:A1992HY06100004 ER PT J AU JOHNSON, WL NORTON, SJ BENDEC, F PLESS, R AF JOHNSON, WL NORTON, SJ BENDEC, F PLESS, R TI ULTRASONIC SPECTROSCOPY OF METALLIC SPHERES USING ELECTROMAGNETIC-ACOUSTIC TRANSDUCTION SO JOURNAL OF THE ACOUSTICAL SOCIETY OF AMERICA LA English DT Article AB An ultrasonic technique for studying vibrational resonant modes of metallic spheres is presented. The technique employs electromagnetic-acoustic transduction with a configuration consisting of a sample surrounded by a coil in a static magnetic field. Resonance spectra from 0.5 to 4.5 MHz with the coil axis parallel and perpendicular to the magnetic field are measured for a 3.145-mm-diam sphere of polycrystalline 2024 aluminum. Elastic constants calculated from the resonant peak frequencies are consistent with results obtained using an ultrasonic pulse-echo system. This new technique has advantages over pulse-echo and conventional resonance techniques for experiments where high absolute accuracy is necessary or where samples are heated far above room temperature. RP JOHNSON, WL (reprint author), NATL INST STAND & TECHNOL,DIV MET,GAITHERSBURG,MD 20899, USA. RI Pless, Robert/I-4698-2013 NR 13 TC 19 Z9 19 U1 0 U2 1 PU AMER INST PHYSICS PI WOODBURY PA CIRCULATION FULFILLMENT DIV, 500 SUNNYSIDE BLVD, WOODBURY, NY 11797-2999 SN 0001-4966 J9 J ACOUST SOC AM JI J. Acoust. Soc. Am. PD MAY PY 1992 VL 91 IS 5 BP 2637 EP 2642 DI 10.1121/1.402971 PG 6 WC Acoustics; Audiology & Speech-Language Pathology SC Acoustics; Audiology & Speech-Language Pathology GA HT688 UT WOS:A1992HT68800017 ER PT J AU KRAUSE, RF AF KRAUSE, RF TI OBSERVED AND THEORETICAL CREEP RATES FOR AN ALUMINA CERAMIC AND A SILICON-NITRIDE CERAMIC IN FLEXURE SO JOURNAL OF THE AMERICAN CERAMIC SOCIETY LA English DT Article DE CREEP; FLEXURE; COMPRESSION; TENSILE; CALCULATIONS AB Observed creep curvature rates are compared to theoretical rates for both an alumina ceramic at 1000-degrees-C and a silicon nitride ceramic at 1200-degrees-C in four-point flexure. The observed rates have been calculated from published rise-displacement rates, and the theoretical rates have been calculated from published power-law parameters for compressive and tensile creep, which differ appreciably for these ceramics. Although both compressive and tensile creep measurements are easier to analyze than flexural creep measurements, the latter are usually less expensive and easier to conduct. The present work shows the usefulness of flexural creep tests to verify the accuracy of compressive and tensile creep tests. RP KRAUSE, RF (reprint author), NATL INST STAND & TECHNOL,GAITHERSBURG,MD 20899, USA. NR 9 TC 9 Z9 9 U1 0 U2 0 PU AMER CERAMIC SOC PI WESTERVILLE PA 735 CERAMIC PLACE, PO BOX 6136, WESTERVILLE, OH 43081-6136 SN 0002-7820 J9 J AM CERAM SOC JI J. Am. Ceram. Soc. PD MAY PY 1992 VL 75 IS 5 BP 1307 EP 1310 DI 10.1111/j.1151-2916.1992.tb05580.x PG 4 WC Materials Science, Ceramics SC Materials Science GA HU733 UT WOS:A1992HU73300045 ER PT J AU BOWEN, RL EICHMILLER, FC MARJENHOFF, WA AF BOWEN, RL EICHMILLER, FC MARJENHOFF, WA TI GAZING INTO THE FUTURE OF AESTHETIC RESTORATIVE MATERIALS SO JOURNAL OF THE AMERICAN DENTAL ASSOCIATION LA English DT Article ID POSTERIOR COMPOSITE RESIN; GLASS-IONOMER CEMENT; MECHANICAL-PROPERTIES; CLINICAL-EVALUATION; FISSURE SEALANTS; DENTAL PRACTICE; CAD-CAM; MICROLEAKAGE; STRENGTH; ANTERIOR AB This article outlines the authors' perceptions of the future of esthetic dental restorative materials such as composites, glass ionomer cements, pit and fissure sealants and laboratory fabricated resin. C1 NATL INST STAND & TECHNOL,AM DENT ASSOC HLTH FDN,PAFFENBARGER RES CTR,GAITHERSBURG,MD 20899. NR 55 TC 4 Z9 4 U1 0 U2 1 PU AMER DENTAL ASSN PI CHICAGO PA 211 E CHICAGO AVE, CHICAGO, IL 60611 SN 0002-8177 J9 J AM DENT ASSOC JI J. Am. Dent. Assoc. PD MAY PY 1992 VL 123 IS 5 BP 33 EP 39 PG 7 WC Dentistry, Oral Surgery & Medicine SC Dentistry, Oral Surgery & Medicine GA HT845 UT WOS:A1992HT84500012 ER PT J AU MARTINEZ, RI GANGULI, B AF MARTINEZ, RI GANGULI, B TI KINETICS AND MECHANISM OF THE COLLISION-ACTIVATED DISSOCIATION OF THE ACETONE CATION SO JOURNAL OF THE AMERICAN SOCIETY FOR MASS SPECTROMETRY LA English DT Article ID TANDEM MASS-SPECTROMETRY; PHOTOELECTRON-PHOTOION COINCIDENCE; METASTABLE ION CHARACTERISTICS; INTERNAL ENERGY-DISTRIBUTIONS; DISTONIC RADICAL CATIONS; NON-ERGODIC BEHAVIOR; POLYATOMIC IONS; MOLECULAR ION; TRIPLE QUADRUPOLES; ALIPHATIC-KETONES AB For center-of-mass collision energies E(cm) = 1-60 eV, the major fragment ions for the collision-activated dissociation (CAD) of the acetone cation are the acetyl cation (m/z 43; absolute branching ratios of 0.96-0.60) and the methyl cation (m/z 15; absolute branching ratios of 0.02-0.26); the absolute total cross-sections were 24-35 angstrom2. The breakdown curves (viz, plots of the absolute branching ratios versus E(cm)) show complex, complementary energy dependences for production of MeCO+ and Me+, indicating apparent closure of the Me+ channel for E(cm) > 30 eV. Our observations are consistent with a competition between three fast, primary (direct) reactions, each of which opens sequentially at its respective threshold energy (viz, reactions 8, 10, and 8'). [GRAPHICS] That is, the breakdown curves for MeCO+ and Me+ (and other CAD fragments) are consistent with the interpretation by other authors that the collisional activation of the acetone cation involves electronic transitions, so that CAD occurs primarily from isolated electronic states (i.e., non-quasi-equilibrium theory (QET) behavior). For acetone we found a correspondence between the photoelectron-photoion-coincidence and CAD breakdown curves. This may indicate that collisional activation in non-QET systems corresponds to scattering angles that emphasize optically allowed transitions accessed by photoionization. RP MARTINEZ, RI (reprint author), NATL INST STAND & TECHNOL,DIV CHEM KINET & THERMODYNAM,GAITHERSBURG,MD 20899, USA. NR 86 TC 12 Z9 12 U1 0 U2 2 PU ELSEVIER SCIENCE INC PI NEW YORK PA 655 AVENUE OF THE AMERICAS, NEW YORK, NY 10010 SN 1044-0305 J9 J AM SOC MASS SPECTR JI J. Am. Soc. Mass Spectrom. PD MAY PY 1992 VL 3 IS 4 BP 427 EP 444 DI 10.1016/1044-0305(92)87070-F PG 18 WC Chemistry, Analytical; Chemistry, Physical; Spectroscopy SC Chemistry; Spectroscopy GA HV637 UT WOS:A1992HV63700017 PM 24243053 ER PT J AU STRUPP, PG ALSTRIN, AL KORTE, BJ LEONE, SR AF STRUPP, PG ALSTRIN, AL KORTE, BJ LEONE, SR TI PULSED LASER IRRADIATION AT 532 NM OF INDIUM AND GA ADSORBED ON SI(100) - DESORPTION, INCORPORATION, AND DAMAGE SO JOURNAL OF VACUUM SCIENCE & TECHNOLOGY A-VACUUM SURFACES AND FILMS LA English DT Article ID MOLECULAR-BEAM EPITAXY; GALLIUM ATOM INTERACTIONS; SPIN-ORBIT STATES; SILICON(100) SURFACES; DESORPTION-KINETICS; INDUCED DIFFUSION; 2-STATE SYSTEM; GROWTH; SI; SEGREGATION AB Laser-induced desorption (LID) of In and Ga from Si(100) under ultrahigh vacuum conditions is investigated. The frequency-doubled 532 nm, 2-6 ns output of a Nd:YAG laser is focused to 0.14 +/- 0.03 J/cm2 on the Si surface to induce desorption. Desorbed In or Ga atoms are detected by laser-induced fluorescence initiated by a second pulsed laser propagating in front of the surface. LID occurs by thermal desorption with approximate desorption energies and preexponential factors in agreement with the literature values obtained previously by isothermal desorption measurements. Experiments at higher coverages suggest that desorption occurs predominantly from the two-dimensional (2D) adlayer with little desorption occurring from the adsorbate islands directly into the vacuum. The 2D layer is resupplied by either diffusion out of adsorbate islands or by diffusion of incorporated adsorbate out of the bulk. Adsorbate-enhanced laser-induced surface damage is also observed; only 0.2 monolayer of In reduces the number of laser pulses required to observe damage by greater than a factor of 30. C1 UNIV COLORADO,DEPT CHEM & BIOCHEM,BOULDER,CO 80309. RP STRUPP, PG (reprint author), UNIV COLORADO,NATL INST STAND & TECHNOL,JOINT INST LAB ASTROPHYS,BOULDER,CO 80302, USA. NR 30 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 1992 VL 10 IS 3 BP 508 EP 514 DI 10.1116/1.578180 PG 7 WC Materials Science, Coatings & Films; Physics, Applied SC Materials Science; Physics GA HU242 UT WOS:A1992HU24200015 ER PT J AU COLLINSON, M BOWDEN, EF TARLOV, MJ AF COLLINSON, M BOWDEN, EF TARLOV, MJ TI VOLTAMMETRY OF COVALENTLY IMMOBILIZED CYTOCHROME-C ON SELF-ASSEMBLED MONOLAYER ELECTRODES SO LANGMUIR LA English DT Article ID WATER-SOLUBLE CARBODIIMIDE; STRUCTURAL CHARACTERIZATION; ALKANETHIOL MONOLAYERS; GOLD ELECTRODES; CROSS-LINKING; COMPLEX; PEROXIDASE; DEHYDROGENASE; SPECTROSCOPY; PLASTOCYANIN AB Cytochrome c was covalently immobilized on carboxylic acid terminated self-assembled monolayer gold electrodes via electrostatically guided carbodiimide coupling. Covalently immobilized cytochrome c was found to be stable, electroactive, and functional. Cyclic voltammetry revealed an electroactive coverage corresponding to ca. one-third monolayer and a surface formal potential slightly negative of the value obtained for electrostatically adsorbed cytochrome c. Electron transfer kinetic results suggest that covalently immobilized and electrostatically adsorbed cytochrome c are similarly oriented at the electrode surface. C1 N CAROLINA STATE UNIV,DEPT CHEM,RALEIGH,NC 27695. NIST,DIV PROC MEASUREMENTS,GAITHERSBURG,MD 20899. RI Collinson, Maryanne/K-8731-2015 OI Collinson, Maryanne/0000-0001-6839-5334 NR 58 TC 256 Z9 257 U1 3 U2 28 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 SN 0743-7463 J9 LANGMUIR JI Langmuir PD MAY PY 1992 VL 8 IS 5 BP 1247 EP 1250 DI 10.1021/la00041a004 PG 4 WC Chemistry, Multidisciplinary; Chemistry, Physical; Materials Science, Multidisciplinary SC Chemistry; Materials Science GA HV782 UT WOS:A1992HV78200005 ER PT J AU TARLOV, MJ NEWMAN, JG AF TARLOV, MJ NEWMAN, JG TI STATIC SECONDARY ION MASS-SPECTROMETRY OF SELF-ASSEMBLED ALKANETHIOL MONOLAYERS ON GOLD SO LANGMUIR LA English DT Article ID ORGANIZED MOLECULAR ASSEMBLIES; ALKYL THIOL MONOLAYERS; STRUCTURAL CHARACTERIZATION; ELECTROCHEMICAL PROPERTIES; SURFACES; FILMS; DISULFIDES; DIFFRACTION; TEMPERATURE; ADSORPTION AB We report a static secondary ion mass spectrometry (SSIMS) study of self-assembled monolayers (SAMs) of alkanethiols [CH3(CH2)nSH, where n = 7, 9, 11, 15, 17] adsorbed on Au. A rich variety of molecular secondary ions are observed in the negative SSIMS spectra including (M - H)-, (AuM)-, (AuSM)-, and (Au2[M - H])- and a relatively strong (Au[M - H]2)- where M is the complete alkanethiol molecule. Sulfonates and alkanesulfonates are observed in SSIMS spectra of SAMs that have been atmosphere exposed for prolonged periods; however, sulfonate species are not detected from samples that are analyzed immediately after withdrawal from thiol-ethanol solutions. SSIMS results indicate that sulfonates formed by air oxidation can be displaced by reimmersion of samples in thiol adsorbate solution. Molecular secondary ions are not observed for perfluoromercaptan and carboxylic acid-terminated SAMs, although spectra distinct from those of the alkanethiol SAMs were obtained. Damage profiles indicate that the emission of molecular secondary ions is very sensitive to extremely low primary ion beam doses. In addition, the relative intensities of Au substrate and molecular ions are strongly influenced by the energy of the primary ion beam suggesting a beam penetration depth effect. C1 EVANS CENT,MINNETONKA,MN 55345. RP TARLOV, MJ (reprint author), NIST,DIV PROC MEASUREMENTS,GAITHERSBURG,MD 20899, USA. NR 48 TC 213 Z9 213 U1 1 U2 10 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 SN 0743-7463 J9 LANGMUIR JI Langmuir PD MAY PY 1992 VL 8 IS 5 BP 1398 EP 1405 DI 10.1021/la00041a026 PG 8 WC Chemistry, Multidisciplinary; Chemistry, Physical; Materials Science, Multidisciplinary SC Chemistry; Materials Science GA HV782 UT WOS:A1992HV78200027 ER PT J AU RONA, PA MEIS, PJ BEAVERSON, CA EMBLEY, RW FOX, CG AF RONA, PA MEIS, PJ BEAVERSON, CA EMBLEY, RW FOX, CG TI GEOLOGIC SETTING OF HYDROTHERMAL ACTIVITY AT THE NORTHERN GORDA RIDGE SO MARINE GEOLOGY LA English DT Article ID PACIFIC-OCEAN; EVOLUTION; PLATE AB The northern end of the northern segment of the rift valley of the Gorda Ridge was investigated with Sea Beam bathymetry, SeaMARC IA and II side-scan sonar, surface-towed magnetics, and near-bottom camera-temperature tows to determine the geologic setting of large chemical anomalies in the water column indicative of intense hydrothermal discharge. The magnitude of the water column anomalies is comparable to that associated with the high-temperature Sea Cliff hydrothermal field situated on the east wall of the rift valley 25 km to the south. Water column and seafloor hydrothermal indicators and tectonic trends converge at a seamount at 42-degrees-57.3'N, 126-degrees-33.0'W situated 4.5 km east of the rift valley axis on a terrace as the most likely source area for the hydrothermal discharge. Comparison with the geologic setting of the Sea Cliff hydrothermal field confirms the presence of an anomalous axis-oblique (340-degrees-357-degrees) tectonic trend that permeates the structure of the northern Gorda Ridge. Additional sinistral offset along an axis-perpendicular structural trend (292-degrees) at the Sea Cliff field indicates a southward increase in deformation of the northern Gorda Ridge along axis-transverse trends. C1 NOAA,PACIFIC MARINE ENVIRONM LAB,HATFIELD MARINE SCI CTR,NEWPORT,OR 97365. RP RONA, PA (reprint author), NOAA,ATLANTIC OCEANOG & METEOROL LAB,4301 RICKENBACKER CAUSEWAY,MIAMI,FL 33149, USA. NR 30 TC 2 Z9 2 U1 0 U2 0 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0025-3227 J9 MAR GEOL JI Mar. Geol. PD MAY PY 1992 VL 106 IS 3-4 BP 189 EP 201 DI 10.1016/0025-3227(92)90129-6 PG 13 WC Geosciences, Multidisciplinary; Oceanography SC Geology; Oceanography GA HW667 UT WOS:A1992HW66700002 ER PT J AU WANG, SDH ZHAN, BY AF WANG, SDH ZHAN, BY TI MARINE FISHERY RESOURCE-MANAGEMENT IN PEOPLES-REPUBLIC-OF-CHINA SO MARINE POLICY LA English DT Article AB This paper describes the PR Chinese marine fishery resources and China's management system. The marine fishery resources are described and resource utilization and associated problems are explained. The management system for marine fishery resources is analysed, including resource propagation and enhancement, mariculture regulations and marine environment protection. The administration and enforcement of the management system are then described. C1 SHANGHAI FISHERIES UNIV,SHANGHAI,PEOPLES R CHINA. RP WANG, SDH (reprint author), NATL MARINE FISHERIES SERV,1 BLACKBURN DR,GLOUCESTER,MA 01930, USA. NR 6 TC 2 Z9 3 U1 1 U2 2 PU BUTTERWORTH-HEINEMANN LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD, OXON, ENGLAND OX5 1GB SN 0308-597X J9 MAR POLICY JI Mar. Pol. PD MAY PY 1992 VL 16 IS 3 BP 197 EP 209 DI 10.1016/0308-597X(92)90081-Y PG 13 WC Environmental Studies; International Relations SC Environmental Sciences & Ecology; International Relations GA HV866 UT WOS:A1992HV86600004 ER PT J AU ESTIN, AJ JUROSHEK, JR MARKS, RB CLAGUE, FR ALLEN, JW AF ESTIN, AJ JUROSHEK, JR MARKS, RB CLAGUE, FR ALLEN, JW TI BASIC RF AND MICROWAVE MEASUREMENTS - A REVIEW OF SELECTED PROGRAMS SO METROLOGIA LA English DT Article ID NETWORK ANALYZER; 6-PORT REFLECTOMETER; DIODE DETECTORS; CALIBRATION; POWER AB This paper summarizes the principles, historical background and present status of three primary areas of rf and microwave measurements and standards: circuit parameter measurement, power measurement, and noise generation and measurement. Both the reference standards and the techniques of measurement and of transfer to secondary standards are addressed. An extensive bibliography is provided to enable the interested reader to pursue areas to greater depth, and brief discussions to indicate likely directions of current and future work are included. C1 NATL INST STAND & TECHNOL, BOULDER LABS, BOULDER, CO 80303 USA. RP CYBERLINK CORP, 1790 30TH ST, SUITE 300, BOULDER, CO 80301 USA. NR 70 TC 3 Z9 3 U1 1 U2 1 PU IOP PUBLISHING LTD PI BRISTOL PA TEMPLE CIRCUS, TEMPLE WAY, BRISTOL BS1 6BE, ENGLAND SN 0026-1394 EI 1681-7575 J9 METROLOGIA JI Metrologia PD MAY PY 1992 VL 29 IS 2 BP 135 EP 151 DI 10.1088/0026-1394/29/2/004 PG 17 WC Instruments & Instrumentation; Physics, Applied SC Instruments & Instrumentation; Physics GA JH328 UT WOS:A1992JH32800004 ER PT J AU CHEN, WY JUANG, HMH AF CHEN, WY JUANG, HMH TI EFFECTS OF TRANSIENT EDDIES ON BLOCKING FLOWS - GENERAL-CIRCULATION MODEL EXPERIMENTS SO MONTHLY WEATHER REVIEW LA English DT Article ID NATIONAL METEOROLOGICAL CENTER; ATMOSPHERIC BLOCKING; MEAN-FLOW; PROPAGATION; ANOMALIES; MODONS; DERF AB Prediction of blocking flows by a comprehensive general circulation model is still not satisfactory. A large portion of the unskillful forecasts can be traced to the model's inability to predict the evolution of blocking beyond a few days into the forecast. Realizing the fact that blocking is often observed to form following a series of intensive cyclogenesis activities and that the model tends to underestimate the intensity of the synoptic-scale transient eddies, a series of 10-day forecasts were conducted to assess the impact of transient eddies on the establishment of blocking flows. When the fast-propagating synoptic-scale disturbances were suppressed in the initial conditions, the subsequent forecasts completely failed to predict a blocking anticyclone. However, when the transient eddies were enhanced in the initial conditions to compensate for the deficiency of the model, blocking flows were predicted and evolved in remarkable agreement with the observations. The dynamical processes during establishment of blocking flow were then examined by a series of daily isentropic potential vorticity charts. The role played by the transient eddies can be identified through these charts, which help to explain why the transient eddies are crucial in establishing the blocking flows. C1 NOAA,NATL WEATHER SERV,NATL METEOROL CTR,CTR CLIMATE ANAL,WASHINGTON,DC 20233. CENTEL FED SERV CO,RESTON,VA. NR 37 TC 15 Z9 16 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 MAY PY 1992 VL 120 IS 5 BP 787 EP 801 DI 10.1175/1520-0493(1992)120<0787:EOTEOB>2.0.CO;2 PG 15 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA HR104 UT WOS:A1992HR10400008 ER PT J AU COKELET, ED AF COKELET, ED TI AXIAL AND CROSS-AXIAL WINTER WINDS OVER PUGET SOUND SO MONTHLY WEATHER REVIEW LA English DT Article ID KINETIC-ENERGY SPECTRUM; HODOGRAPH; ROTATION; FJORD; SILL AB A local, two-dimensional principal-component analysis has been applied to mesoscale winds in a region strongly influenced by topography. The principal components successfully separate axial winds over Puget Sound from cross-axial winds. Energy spectra of winter axial winds contain significant peaks at synoptic-scale periods of 1.5-5 days but also a strong peak of unknown origin at 17 days. Cross-axial winds are dominated by the land-sea breeze. Day-night asymmetries in the land-sea temperature contrast lead to diurnal modulation and energy at the semidiurnal period. The land breeze persists in winter over Puget Sound, but the sea breeze dominates a weakened land breeze in summer. RP COKELET, ED (reprint author), NOAA,PACIFIC MARINE ENVIRONM LAB,R-E-PM,BIN C15700 BLDG 3,SEATTLE,WA 98115, USA. NR 37 TC 3 Z9 3 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 MAY PY 1992 VL 120 IS 5 BP 826 EP 834 DI 10.1175/1520-0493(1992)120<0826:AACAWW>2.0.CO;2 PG 9 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA HR104 UT WOS:A1992HR10400011 ER PT J AU FLAMBAUM, VV AF FLAMBAUM, VV TI LONG-RANGE PARITY-NONCONSERVING INTERACTION SO PHYSICAL REVIEW A LA English DT Article ID ELECTRIC-DIPOLE MOMENT; WEAK NEUTRAL CURRENTS; DIATOMIC-MOLECULES; ATOMIC PHYSICS; ENHANCEMENT; NUCLEON; SEARCH; LIMIT AB There is a long-range parity-nonconserving (PNC) interaction between a charged particle and a composite system (atom, nucleus) induced by the usual contact weak interaction inside this system: U = (H X E).J-beta(v), approximately 1/R4 or 1/R5, where R is distance, E and H are electric and magnetic fields of the particle, and J and beta(v) are the angular momentum and PNC vector polarizability of the system. The mechanisms of enhancement of PNC vector polarizability are considered. PNC effects in atoms, molecules, and solids are discussed (P-odd and T-even electric dipole moment, P-odd electric field, etc.). C1 NATL INST STAND & TECHNOL, BOULDER, CO 80309 USA. NOVOSIBIRSK NUCL PHYS INST, NOVOSIBIRSK 630090, USSR. RP UNIV COLORADO, JOINT INST LAB ASTROPHYS, BOULDER, CO 80309 USA. NR 47 TC 3 Z9 3 U1 0 U2 4 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 MAY 1 PY 1992 VL 45 IS 9 BP 6174 EP 6179 DI 10.1103/PhysRevA.45.6174 PG 6 WC Optics; Physics, Atomic, Molecular & Chemical SC Optics; Physics GA HT733 UT WOS:A1992HT73300006 ER PT J AU THUMM, U NORCROSS, DW AF THUMM, U NORCROSS, DW TI RELATIVISTIC R-MATRIX CALCULATIONS FOR ELECTRON ALKALI-METAL-ATOM SCATTERING - CS AS A TEST CASE SO PHYSICAL REVIEW A LA English DT Article ID NEGATIVE-IONS; CESIUM; EQUATIONS; ENERGIES; SODIUM; ASYPCK AB We have reformulated the Dirac R-matrix method for low-energy electron scattering by (effectively) one-electron, alkali-metal-like systems and developed an independent computer program for this special purpose. A highly accurate and relativistic representation of the target was used to perform a multichannel close-coupling calculation of cross sections for electron scattering. Our results include the negative-ion affinity and elastic, inelastic, and total cross sections for incident electrons with 0 to 2.8 eV kinetic energy. We find that core-polarization and relativistic effects lead to multiplets of very narrow P-3(J), J = 0, 1, 2 shape resonances: the effect of the induced core polarization on the electron-electron correlation leads to 6s6p P-3(J)o resonances in contrast to previously predicted bound states of Cs-, and relativistic interactions are responsible for the autoionizing decay of 6p2 P-3(J) states below the first excitation threshold. C1 NATL INST STAND & TECHNOL,BOULDER,CO 80309. RP THUMM, U (reprint author), UNIV COLORADO,JOINT INST LAB ASTROPHYS,BOULDER,CO 80309, USA. OI Thumm, Uwe/0000-0001-9378-6601 NR 53 TC 45 Z9 45 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 MAY 1 PY 1992 VL 45 IS 9 BP 6349 EP 6370 DI 10.1103/PhysRevA.45.6349 PG 22 WC Optics; Physics, Atomic, Molecular & Chemical SC Optics; Physics GA HT733 UT WOS:A1992HT73300028 ER PT J AU BUFFA, G TARRINI, O DENATALE, P INGUSCIO, M PAVONE, FS PREVEDELLI, M EVENSON, KM ZINK, LR SCHWAAB, GW AF BUFFA, G TARRINI, O DENATALE, P INGUSCIO, M PAVONE, FS PREVEDELLI, M EVENSON, KM ZINK, LR SCHWAAB, GW TI FAR-INFRARED SELF-BROADENING IN METHYLCYANIDE - ABSORBER-PERTURBER RESONANCE SO PHYSICAL REVIEW A LA English DT Article ID ROTATIONAL LINES; SPECTRUM; SHIFT AB Using tunable far-infrared spectrometers with high-frequency stability and accuracy, we have measured the self-pressure broadening and shift of CH3CN. We obtained clear evidence of absorber-perturber resonance effects on the collisional line shape. This tests the theoretical model and its possible improvements and also allows us to make broadening and shift predictions for a large class of molecules. Moreover, the resonance effect produces a theoretical temperature dependence of self-broadening that is very different from what is commonly assumed. C1 EUROPEAN LAB NONLINEAR SPECT, I-50125 FLORENCE, ITALY. UNIV FLORENCE, DIPARTIMENTO FIS, I-50125 FLORENCE, ITALY. NATL INST STAND & TECHNOL, BOULDER, CO 80303 USA. MAX PLANCK INST RADIOASTRON, W-5300 BONN, GERMANY. RP BUFFA, G (reprint author), UNIV PISA, DIPARTIMENTO FIS, PIAZZA TORRICELLI 2, I-56100 PISA, ITALY. RI pavone, francesco/F-4945-2015; OI pavone, francesco saverio/0000-0002-0675-3981; De Natale, Paolo/0000-0002-3308-8569; Prevedelli, Marco/0000-0002-3136-2392 NR 21 TC 20 Z9 21 U1 0 U2 3 PU AMER 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 1992 VL 45 IS 9 BP 6443 EP 6450 DI 10.1103/PhysRevA.45.6443 PG 8 WC Optics; Physics, Atomic, Molecular & Chemical SC Optics; Physics GA HT733 UT WOS:A1992HT73300039 ER PT J AU RAIZEN, MG GILLIGAN, JM BERGQUIST, JC ITANO, WM WINELAND, DJ AF RAIZEN, MG GILLIGAN, JM BERGQUIST, JC ITANO, WM WINELAND, DJ TI IONIC-CRYSTALS IN A LINEAR PAUL TRAP SO PHYSICAL REVIEW A LA English DT Article ID QUANTUM JUMPS; SINGLE-ION; LASER; SPECTROSCOPY; FLUORESCENCE AB We describe a configuration for a linear Paul rf ion trap. This trap can store a long string of ions with a small second-order Doppler shift, comparable to that achieved with a single ion in a quadrupole Paul trap. Crystallized strings of trapped ions, as well as more complicated structures, have been observed in the trap. We report an observation of the 40.5-GHz ground-state hyperfine interval of Hg-199(+) by microwave-optical double-resonance spectroscopy and discuss prospects for a microwave frequency standard based on a trapped string of ions. C1 NATL INST STAND & TECHNOL,DIV TIME & FREQUENCY,BOULDER,CO 80303. RI Gilligan, Jonathan/I-8938-2014 OI Gilligan, Jonathan/0000-0003-1375-6686 NR 34 TC 205 Z9 209 U1 5 U2 21 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 1050-2947 J9 PHYS REV A JI Phys. Rev. A PD MAY 1 PY 1992 VL 45 IS 9 BP 6493 EP 6501 DI 10.1103/PhysRevA.45.6493 PG 9 WC Optics; Physics, Atomic, Molecular & Chemical SC Optics; Physics GA HT733 UT WOS:A1992HT73300044 ER PT J AU TRIPPENBACH, M GAO, B COOPER, J BURNETT, K AF TRIPPENBACH, M GAO, B COOPER, J BURNETT, K TI SLOW COLLISIONS BETWEEN IDENTICAL ATOMS IN A LASER FIELD - APPLICATION OF THE BORN AND MARKOV APPROXIMATIONS TO THE SYSTEM OF MOVING ATOMS SO PHYSICAL REVIEW A LA English DT Article ID DENSITY-MATRIX; RADIATION; REDISTRIBUTION; MOTION; FLUORESCENCE AB We have derived reduced-density-matrix equations of motion for a pair of two identical atoms moving in the radiation field as the first step in establishing a theory of collisional redistribution of light from neutral-atom traps. We use the Zwanzig projection-operator technique to average over spontaneous field modes and establish the conditions under which Born and Markov approximations can be applied to the system of moving atoms. It follows from these considerations that when these conditions hold, the reduced-density-matrix equation for moving atoms has the same form as that for the stationary case: time dependence is introduced into the decay rates and interaction potentials by making the substitution R = R(t). C1 NATL INST STAND & TECHNOL,BOULDER,CO 80309. UNIV OXFORD,CLARENDON LAB,OXFORD OX1 3PU,ENGLAND. RP TRIPPENBACH, M (reprint author), UNIV COLORADO,JOINT INST LAB ASTROPHYS,BOULDER,CO 80309, USA. RI Gao, Bo/B-8774-2008 OI Gao, Bo/0000-0002-6680-3725 NR 33 TC 14 Z9 14 U1 1 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 MAY 1 PY 1992 VL 45 IS 9 BP 6539 EP 6554 DI 10.1103/PhysRevA.45.6539 PG 16 WC Optics; Physics, Atomic, Molecular & Chemical SC Optics; Physics GA HT733 UT WOS:A1992HT73300048 ER PT J AU TRIPPENBACH, M GAO, B COOPER, J BURNETT, K AF TRIPPENBACH, M GAO, B COOPER, J BURNETT, K TI SLOW COLLISIONS BETWEEN IDENTICAL ATOMS IN A LASER FIELD - THE SPECTRUM OF REDISTRIBUTED LIGHT SO PHYSICAL REVIEW A LA English DT Article ID RADIATION; EQUATION; MOTION AB The resonance fluorescence from a system of interacting, identical, and cold (trapped) atoms driven by a laser field is derived. The effects of dressing by the laser field and radiative decay are all included. We examine in detail the applicability of the binary-collision approximation for this problem, which is a special case of resonance broadening. The final result allows a clear physical interpretation and shows interesting features due to the resonant exchange of coherences and excitations. Correspondence with previous work is also discussed. C1 UNIV COLORADO,JOINT INST LAB ASTROPHYS,BOULDER,CO 80309. NATL INST STAND & TECHNOL,BOULDER,CO 80309. UNIV OXFORD,CLARENDON LAB,OXFORD OX1 3PU,ENGLAND. RI Gao, Bo/B-8774-2008 OI Gao, Bo/0000-0002-6680-3725 NR 26 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 1050-2947 J9 PHYS REV A JI Phys. Rev. A PD MAY 1 PY 1992 VL 45 IS 9 BP 6555 EP 6569 DI 10.1103/PhysRevA.45.6555 PG 15 WC Optics; Physics, Atomic, Molecular & Chemical SC Optics; Physics GA HT733 UT WOS:A1992HT73300049 ER PT J AU CATICHA, A AF CATICHA, A TI QUANTUM-THEORY OF THE DYNAMIC CERENKOV EMISSION OF X-RAYS SO PHYSICAL REVIEW B LA English DT Article ID BRAGG ANGLES; ULTRARELATIVISTIC ELECTRONS; RELATIVISTIC ELECTRONS; DIFFRACTION; RADIATION; CRYSTAL; PI/2 AB X-ray photons propagating in a crystal close to the Bragg-diffraction directions have an effective index of refraction that may be larger than 1. Electrons moving rapidly in crystals may therefore emit x rays. This process, the dynamical Cerenkov radiation (DCR) of x rays, is studied with use of a theory that is closely analogous to the quantum theory of the Cerenkov effect in homogeneous media. Features of the DCR process that are calculated include the spectral width due to x-ray absorption, the systematic deviations of the photon energy from Bragg's law, the influence of the orientation of the crystal surface, etc. Extensions of the theory to cover many-beam diffraction cases or more detailed calculations of the small recoil effects are straightforward to carry out. The photons are emitted at the far tails of the diffraction region, they are overwhelmingly in the "diffracted" plane-wave component, and, in the two-beam case there is no anomalous Borrmann absorption. DCR is a particularly efficient emission process for hard x rays (several tens of keV) with extremely high spectral density (within small angular regions). The emission rate is highest at the energy HBAR-omega = gamma-HBAR-omega(p) (omega(p) is the plasma frequency), but, because of absorption, the number of photons that actually emerge from the crystal will peak at appreciably higher energies. The production of photons of a given energy is optimized by using lattice planes with the lowest possible Miller indices and by asymmetrically cutting the crystal surface. The use of DCR for a tunable source of hard x rays should therefore be seriously considered. C1 UNIV MARYLAND,INST PHYS SCI & TECHNOL,COLLEGE PK,MD 20742. RP CATICHA, A (reprint author), NATL INST STAND & TECHNOL,GAITHERSBURG,MD 20899, USA. NR 32 TC 44 Z9 44 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 1992 VL 45 IS 17 BP 9541 EP 9550 DI 10.1103/PhysRevB.45.9541 PG 10 WC Physics, Condensed Matter SC Physics GA HR543 UT WOS:A1992HR54300001 ER PT J AU HUANG, Q KAREN, P KAREN, VL KJEKSHUS, A LYNN, JW MIGHELL, AD ROSOV, N SANTORO, A AF HUANG, Q KAREN, P KAREN, VL KJEKSHUS, A LYNN, JW MIGHELL, AD ROSOV, N SANTORO, A TI NEUTRON-POWDER-DIFFRACTION STUDY OF THE NUCLEAR AND MAGNETIC-STRUCTURES OF YBA2FE3O8 AT ROOM-TEMPERATURE SO PHYSICAL REVIEW B LA English DT Article ID CRYSTAL-STRUCTURE; SUPERCONDUCTORS; YBA2CU3O7; COBALT; ORDER; CU AB The nuclear and magnetic structures of YBa2Fe3O8 have been investigated by powder neutron diffraction at room temperature. The nuclear structure of the compound has the symmetry of space group P4/mmm and lattice parameters a = 3.9170(1) and c = 11.8252(4) angstrom. The configuration of the atoms in the unit cell is very similar to that of the superconductor YBa2Cu3O7, with the exception that the iron ions corresponding to the Cu-chain ions have octahedral coordination, rather than square planar; the octahedra thus are arranged in layers rather than in chains. This significant difference is a consequence of the fact that all possible oxygen sites in these layers are fully occupied, resulting in an oxygen content of eight rather than seven atoms per formula unit. A second consequence of the full occupancy of the oxygen sites is that the Ba ions have a twelvefold cuboctahedral coordination in the iron compound, rather than tenfold. The magnetic structure is based on a unit cell related to that of the nuclear structure by an axis transformation of matrix (110BAR/110/002). The magnetic origin of the extra intensities and the basic spin configuration were determined by polarized-neutron-diffraction measurements. The iron moments are coupled antiferromagnetically within each FeO2 layer, as well as along the c axis. The magnetic moments of all the iron ions are the same with a value of 3.49(2)mu(B). This configuration results in the magnetic symmetry I(c)mm'm. C1 UNIV OSLO,DEPT CHEM,N-0315 OSLO 3,NORWAY. UNIV MARYLAND,CTR SUPERCONDUCT RES,DEPT PHYS,COLLEGE PK,MD 20742. RP HUANG, Q (reprint author), NATL INST STAND & TECHNOL,DIV REACTOR RADIAT,GAITHERSBURG,MD 20899, USA. RI Karen, Pavel/A-9062-2008 OI Karen, Pavel/0000-0003-2937-6477 NR 25 TC 70 Z9 73 U1 2 U2 14 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 0163-1829 J9 PHYS REV B JI Phys. Rev. B PD MAY 1 PY 1992 VL 45 IS 17 BP 9611 EP 9619 DI 10.1103/PhysRevB.45.9611 PG 9 WC Physics, Condensed Matter SC Physics GA HR543 UT WOS:A1992HR54300008 ER PT J AU ZHANG, H LYNN, JW MORRIS, DE AF ZHANG, H LYNN, JW MORRIS, DE TI COUPLED-BILAYER 2-DIMENSIONAL MAGNETIC ORDER OF THE DY IONS IN DY2BA4CU7O15 SO PHYSICAL REVIEW B LA English DT Article ID HOLMIUM-RICH (ER1-XHOX)RH4B4; DIMENSIONAL MAGNETISM; HEAT; DYBA2CU3O7-DELTA; ERBA2CU3O7; ER AB Neutron scattering has been used to investigate the magnetic ordering of the Dy ions in the superconducting (T(c) almost-equal-to 60 K) Dy2Ba4Cu7O15 (2:4:7) material. A modulated saw-tooth scattering profile is observed, indicative of a coupled-bilayer two-dimensional (2D) system in which the nearest-neighbor Dy spins within the a-b plane are coupled antiferromagnetically, with the moment direction along the c axis. The a-b-plane spin configuration is identical to the one which has been observed for the related DyBa2Cu3O7 (1:2:3) and Dy2Ba4Cu8O16 (2:4:8) materials. The Neel temperature in the present system is found to be approximately 1.3 K, while no three-dimensional (3D) long-range order is seen to the lowest temperature measured (approximately 90 mK). The 2D behavior of this system originates from two sources. First, the c-axis spacing of the magnetic ions is approximately 3 times the a-b spacing, and this structural anisotropy renders the c-axis interaction much weaker than the interactions within the a-b plane. Indeed we find that the calculated dipolar interaction between layers varies exponentially with distance, and is reduced by a factor of 7000 compared with the intralayer interactions. Second, every other a-b layer is shifted along the b axis by b/2, which causes a cancellation of the magnetic interplane interactions between the shifted and unshifted layers. Hence the magnetic system consists of sets of isolated bilayers. We anticipate that a similar coupled-bilayer 2D behavior should occur in other R2Ba4Cu7O15 systems (R = rare-earth element, except Er) which exhibit the same a-b-plane spin configuration as the Dy. C1 NATL INST STAND & TECHNOL,GAITHERSBURG,MD 20899. MORRIS RES,BERKELEY,CA 94704. RP ZHANG, H (reprint author), UNIV MARYLAND,CTR SUPERCONDUCT RES,DEPT PHYS,COLLEGE PK,MD 20742, USA. NR 22 TC 25 Z9 25 U1 0 U2 1 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 0163-1829 J9 PHYS REV B JI Phys. Rev. B PD MAY 1 PY 1992 VL 45 IS 17 BP 10022 EP 10031 DI 10.1103/PhysRevB.45.10022 PG 10 WC Physics, Condensed Matter SC Physics GA HR543 UT WOS:A1992HR54300056 ER PT J AU GOLDMAN, AI STASSIS, C DEBOISSIEU, M CURRAT, R JANOT, C BELLISSENT, R MOUDDEN, H GAYLE, FW AF GOLDMAN, AI STASSIS, C DEBOISSIEU, M CURRAT, R JANOT, C BELLISSENT, R MOUDDEN, H GAYLE, FW TI PHONONS IN ICOSAHEDRAL AND CUBIC AL-LI-CU SO PHYSICAL REVIEW B LA English DT Article ID ONE-DIMENSIONAL QUASICRYSTALS; INELASTIC NEUTRON-SCATTERING; QUASI-CRYSTALS; INCOMMENSURATE CRYSTALS; MOMENTS METHOD; SPECIAL POINTS; DIFFRACTION; MODES; MN; QUASILATTICES AB We describe the results of inelastic-neutron-scattering measurements on single grains of icosahedral Al-Li-Cu and the related cubic R phase. Measurements along the high-symmetry twofold, threefold, and fivefold axes of the icosahedral phase clearly show the existence of well-defined propagating modes, with isotropic dispersion, near strong Bragg peaks. The spectral weight of the acoustic phonons scale linearly with the integrated intensity of the associated zone centers. In several cases we are able to identify "quasi"-Brillouin-zones, with stationary points at the "special" high-symmetry points of a simple icosahedral lattice. While the phonon dispersion for transverse and longitudinal acoustic modes along the twofold axis of the cubic R phase is quite similar to that found for the icosahedral phase, differences are found in the higher-energy modes; the behavior of the higher-energy modes of the icosahedral phase is consistent with an enhanced degree of spatial localization for these excitations. C1 IOWA STATE UNIV SCI & TECHNOL,DEPT PHYS & ASTRON,AMES,IA 50011. INST MAX VON LAUE PAUL LANGEVIN,F-38042 GRENOBLE,FRANCE. CENS,LAB LEON BRILLOUIN,F-91191 GIF SUR YVETTE,FRANCE. NATL INST STAND & TECHNOL,DIV MET,GAITHERSBURG,MD 20899. RP GOLDMAN, AI (reprint author), IOWA STATE UNIV SCI & TECHNOL,AMES LAB,AMES,IA 50011, USA. NR 56 TC 44 Z9 44 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 MAY 1 PY 1992 VL 45 IS 18 BP 10280 EP 10291 DI 10.1103/PhysRevB.45.10280 PG 12 WC Physics, Condensed Matter SC Physics GA HT386 UT WOS:A1992HT38600010 ER PT J AU LATAITIS, RJ AF LATAITIS, RJ TI SIGNAL POWER FOR RADIO ACOUSTIC SOUNDING OF TEMPERATURE - THE EFFECTS OF HORIZONTAL WINDS, TURBULENCE, AND VERTICAL TEMPERATURE-GRADIENTS SO RADIO SCIENCE LA English DT Article ID BOUNDARY-LAYER; SYSTEM RASS; RADAR; PROFILE AB A simple expression for the expected average signal power of a radio acoustic sounding system (RASS) comprising a monostatic pulsed Doppler radar and a continuous-wave broadbeam acoustic source is developed. The effects of horizontal winds, atmospheric turbulence, and vertical temperature gradients are included. Under ideal conditions (i.e., in the absence of winds, turbulence, and gradients) the received signal power is a maximum and, for a broadband acoustic source, is predicted to be proportional to the radar range resolution and inversely proportional to the acoustic bandwidth and square of the range R. Turbulence-induced distortion of the acoustic wave fronts yields the expected R-26/5 range dependence, provided winds are light. This result is based on the assumption that the turbulence strength does not vary with range. For the more realistic case of turbulence concentrated primarily within the boundary layer (R less-than-or-equal-to 1 km) a much weaker range dependence at longer ranges is predicted. A flattening of the acoustic wave fronts by temperature gradients typical of unstable midday conditions results in an R-6 range dependence, provided winds are light. Turbulence effects are predicted to dominate at shorter ranges (R less-than-or-equal-to 8 km) and gradient effects at longer ranges. The expected compensation of power loss associated with the wind-induced lateral displacement of the acoustic wave fronts by the turbulence- and gradient-induced broadening of the displaced RASS focal spot is also predicted. RP LATAITIS, RJ (reprint author), NOAA,ENVIRONM RES LAB,WAVE PROPAGAT LAB,325 BROADWAY,BOULDER,CO 80303, USA. NR 66 TC 18 Z9 18 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 MAY-JUN PY 1992 VL 27 IS 3 BP 369 EP 385 DI 10.1029/92RS00004 PG 17 WC Astronomy & Astrophysics; Geochemistry & Geophysics; Meteorology & Atmospheric Sciences; Remote Sensing; Telecommunications SC Astronomy & Astrophysics; Geochemistry & Geophysics; Meteorology & Atmospheric Sciences; Remote Sensing; Telecommunications GA HX850 UT WOS:A1992HX85000001 ER PT J AU JAIN, K EHRLICH, C HOUCK, J AF JAIN, K EHRLICH, C HOUCK, J TI INTERCOMPARISON OF HYDRAULIC PRESSURE MEASUREMENTS TO 28-MPA USING A SINGLE-PISTON GAUGE IN THE CONTROLLED-CLEARANCE, REENTRANT, AND SIMPLE CONFIGURATIONS SO REVIEW OF SCIENTIFIC INSTRUMENTS LA English DT Article AB The use of controlled-clearance piston gauges as highly accurate primary pressure standards is well established. However, the operation of a controlled-clearance gauge is more complicated than that of the familiar simple or reentrant designs. An investigation has been performed on a modified design of a piston gauge for which the same piston/cylinder can be operated in either the controlled-clearance, simple, or reentrant modes, to determine the degree of degradation in accuracy of measured pressure using the gauge in either the simple or reentrant modes as a standard. How the particular characterization of the standard gauge affects the calibration parameters of a test gauge is also explored. The effective areas of the test gauge are within 4.5 parts per million (ppm) when the standard is used in the simple mode instead of the controlled-clearance mode, up to a pressure of 28 MPa, whereas in the case of the reentrant mode this deviation increases from 2.5 ppm at 7 MPa to 14 ppm at 26 MPa. C1 NATL INST STAND & TECHNOL,DIV THERMOPHYS,GAITHERSBURG,MD 20899. RP JAIN, K (reprint author), NATL PHYS LAB,DIV PRESSURE & VACUUM,NEW DELHI 110012,INDIA. NR 5 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 0034-6748 J9 REV SCI INSTRUM JI Rev. Sci. Instrum. PD MAY PY 1992 VL 63 IS 5 BP 3127 EP 3135 DI 10.1063/1.1142565 PG 9 WC Instruments & Instrumentation; Physics, Applied SC Instruments & Instrumentation; Physics GA HR942 UT WOS:A1992HR94200035 ER PT J AU RIPPLE, D AF RIPPLE, D TI A COMPACT, HIGH-PRESSURE CAPILLARY VISCOMETER SO REVIEW OF SCIENTIFIC INSTRUMENTS LA English DT Article AB A high-pressure capillary viscometer is described. Similar to an Ubbelhode viscometer, the instrument is compact, requires a sample of only 1 ml of saturated liquid, and is simple to make and use. The viscometer can readily measure kinematic viscosities as small as 2 X 10(-7) m2/s and can sustain vapor pressures over 1 MPa. The sample contacts only sapphire, stainless steel, and gold, allowing measurement of corrosive liquids. The overall accuracy is approximately 3%. RP RIPPLE, D (reprint author), US DEPT COMMERCE,TECHNOL ADM,NATL INST STAND & TECHNOL,DIV THERMOPHYS,GAITHERSBURG,MD 20899, USA. NR 10 TC 9 Z9 11 U1 0 U2 4 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 MAY PY 1992 VL 63 IS 5 BP 3153 EP 3155 DI 10.1063/1.1143816 PG 3 WC Instruments & Instrumentation; Physics, Applied SC Instruments & Instrumentation; Physics GA HR942 UT WOS:A1992HR94200039 ER PT J AU CHARLSON, RJ SCHWARTZ, SE HALES, JM CESS, RD COAKLEY, JA HANSEN, JE HOFMANN, DJ AF CHARLSON, RJ SCHWARTZ, SE HALES, JM CESS, RD COAKLEY, JA HANSEN, JE HOFMANN, DJ TI AEROSOLS AND GLOBAL WARMING - RESPONSE SO SCIENCE LA English DT Letter C1 UNIV WASHINGTON, INST ENVIRONM STUDIES, SEATTLE, WA 98195 USA. BROOKHAVEN NATL LAB, DIV ENVIRONM CHEM, UPTON, NY 11973 USA. PACIFIC NW LAB, DEPT ATMOSPHER SCI, RICHLAND, WA 99352 USA. SUNY STONY BROOK, INST TERR & PLANETARY ATMOSPHERES, STONY BROOK, NY 11794 USA. OREGON STATE UNIV, DEPT ATMOSPHER SCI, CORVALLIS, OR 97331 USA. NASA, GODDARD INST SPACE STUDIES, NEW YORK, NY 10025 USA. NOAA, CLIMATE MONITORING & DIAGNOST LAB, BOULDER, CO 80303 USA. RP CHARLSON, RJ (reprint author), UNIV WASHINGTON, DEPT ATMOSPHER SCI, SEATTLE, WA 98195 USA. RI Schwartz, Stephen/C-2729-2008 OI Schwartz, Stephen/0000-0001-6288-310X NR 6 TC 12 Z9 12 U1 3 U2 8 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 1 PY 1992 VL 256 IS 5057 BP 598 EP 599 DI 10.1126/science.256.5057.598-a PG 2 WC Multidisciplinary Sciences SC Science & Technology - Other Topics GA HR185 UT WOS:A1992HR18500003 PM 17843469 ER PT J AU GENTRY, RL AF GENTRY, RL TI DOLPHIN SOCIETIES - DISCOVERIES AND PUZZLES - PRYOR,K, NORRIS,KS SO SCIENCE LA English DT Book Review RP GENTRY, RL (reprint author), NOAA,NATL MARINE MAMMAL LAB,SEATTLE,WA 98115, USA. NR 1 TC 1 Z9 1 U1 0 U2 3 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 1 PY 1992 VL 256 IS 5057 BP 681 EP 682 DI 10.1126/science.256.5057.681 PG 2 WC Multidisciplinary Sciences SC Science & Technology - Other Topics GA HR185 UT WOS:A1992HR18500039 PM 17843490 ER PT J AU COLLIER, TK STEIN, JE SANBORN, HR HOM, T MYERS, MS VARANASI, U AF COLLIER, TK STEIN, JE SANBORN, HR HOM, T MYERS, MS VARANASI, U TI FIELD STUDIES OF REPRODUCTIVE SUCCESS AND BIOINDICATORS OF MATERNAL CONTAMINANT EXPOSURE IN ENGLISH SOLE (PAROPHRYS-VETULUS) SO SCIENCE OF THE TOTAL ENVIRONMENT LA English DT Article DE REPRODUCTION; FISH; CONTAMINANTS; POLYCHLORINATED BIPHENYLS; AROMATIC HYDROCARBONS ID PUGET-SOUND; WASHINGTON; FISH; HYDROCARBONS; METABOLITES; SEDIMENTS; FLOUNDER; ENZYMES; LESIONS AB Our studies have shown that early stages of the reproductive process in female English sole (Parophrys vetulus) are disrupted by contaminant exposure. To determine the potential for contaminants to affect later stages of the reproductive cycle, we examined the effects of maternal contaminant exposure on egg and larval viability in this species, in a field study conducted on running ripe fish collected for two consecutive years from spawning grounds. Maternal contaminant exposure was assessed by measuring levels of polychlorinated biphenyls (PCBs) in ovarian and hepatic tissue, biliary levels of fluorescent aromatic compounds (FACs), and hepatic aryl hydrocarbon hydroxylase (AHH) activities. Additionally, the presence of significant liver disease or ovarian atresia was documented, and levels of plasma estradiol were measured. Stepwise multiple regression of the data showed that contaminant exposure was only a minor factor in determining both egg and larval viability. Hepatic AHH activity showed a slight negative correlation with fertilization success, explaining only 4% of the variability. Increased levels of PCBs in ovaries of spawning female English sole were not associated with reduced reproductive success. However, because the range of contaminant exposure in the spawning fish did not encompass the high levels seen in non-spawning fish captured from contaminated areas, it can be hypothesized that female English sole exposed to substantial levels of contaminants might be at least partially excluded from the spawning population. 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 29 TC 24 Z9 26 U1 1 U2 9 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 1992 VL 116 IS 1-2 BP 169 EP 185 DI 10.1016/0048-9697(92)90372-Y PG 17 WC Environmental Sciences SC Environmental Sciences & Ecology GA HV279 UT WOS:A1992HV27900012 ER PT J AU NAIR, VN ABRAHAM, B MACKAY, J BOX, G KACKER, RN LORENZEN, TJ LUCAS, JM MYERS, RH VINING, GG NELDER, JA PHADKE, MS SACKS, J WELCH, WJ SHOEMAKER, AC TSUI, KL TAGUCHI, S WU, CFJ AF NAIR, VN ABRAHAM, B MACKAY, J BOX, G KACKER, RN LORENZEN, TJ LUCAS, JM MYERS, RH VINING, GG NELDER, JA PHADKE, MS SACKS, J WELCH, WJ SHOEMAKER, AC TSUI, KL TAGUCHI, S WU, CFJ TI TAGUCHI PARAMETER DESIGN - A PANEL DISCUSSION SO TECHNOMETRICS LA English DT Discussion DE DESIGN OF EXPERIMENTS; DISPERSION OF EFFECTS; LOCATION EFFECTS; ROBUST DESIGN; SN RATIOS; VARIATION REDUCTION ID LINE QUALITY-CONTROL; ORDERED CATEGORICAL-DATA; TO-NOISE RATIOS; INDUSTRIAL EXPERIMENTS; FACTORIAL-EXPERIMENTS; COMPUTER EXPERIMENTS AB It is more than a decade since Genichi Taguchi's ideas on quality improvement were introduced in the United States. His parameter-design approach for reducing variation in products and processes has generated a great deal of interest among both quality practitioners and statisticians. The statistical techniques used by Taguchi to implement parameter design have been the subject of much debate, however, and there has been considerable research aimed at integrating the parameter-design principles with well-established statistical techniques. On the other hand, Taguchi and his colleagues feel that these research efforts by statisticians are misguided and reflect a lack of understanding of the engineering principles underlying Taguchi's methodology. This panel discussion provides a forum for a technical discussion of these diverse views. A group of practitioners and researchers discuss the role of parameter design and Taguchi's methodology for implementing it. The topics covered include the importance of variation reduction, the use of noise factors, the role of interactions, selection of quality characteristics, signal-to-noise ratios, experimental strategy, dynamic systems, and applications. The discussion also provides an up-to-date overview of recent research on alternative methods of design and analysis. C1 UNIV WATERLOO,WATERLOO N2L 3G1,ONTARIO,CANADA. UNIV WISCONSIN,MADISON,WI 53706. NATL INST STAND & TECHNOL,BOULDER,CO. GM CORP,RES LABS,DETROIT,MI 48202. DUPONT CO,CTR QUAL MANAGEMENT & TECHNOL,WILMINGTON,DE 19898. UNIV FLORIDA,GAINESVILLE,FL 32611. VIRGINIA POLYTECH INST & STATE UNIV,BLACKSBURG,VA 24061. UNIV LONDON IMPERIAL COLL SCI TECHNOL & MED,LONDON SW7 2AZ,ENGLAND. GEORGIA INST TECHNOL,ATLANTA,GA 30332. RP NAIR, VN (reprint author), AT&T BELL LABS,MURRAY HILL,NJ 07974, USA. NR 106 TC 332 Z9 343 U1 2 U2 31 PU AMER STATISTICAL ASSOC PI ALEXANDRIA PA 1429 DUKE ST, ALEXANDRIA, VA 22314 SN 0040-1706 J9 TECHNOMETRICS JI Technometrics PD MAY PY 1992 VL 34 IS 2 BP 127 EP 161 DI 10.2307/1269231 PG 35 WC Statistics & Probability SC Mathematics GA HQ464 UT WOS:A1992HQ46400001 ER PT J AU THIEBAUX, HJ MORONE, LL AF THIEBAUX, HJ MORONE, LL TI SHORT-TERM SYSTEMATIC-ERRORS IN GLOBAL FORECASTS - THEIR ESTIMATION AND REMOVAL - REPLY SO TELLUS SERIES A-DYNAMIC METEOROLOGY AND OCEANOGRAPHY LA English DT Letter RP THIEBAUX, HJ (reprint author), NOAA,NATL METEOROL CTR,NWS,WASHINGTON,DC 20230, USA. NR 0 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 0280-6495 J9 TELLUS A JI Tellus Ser. A-Dyn. Meteorol. Oceanol. PD MAY PY 1992 VL 44A IS 3 BP 272 EP 272 DI 10.1034/j.1600-0870.1992.t01-2-00007.x PG 1 WC Meteorology & Atmospheric Sciences; Oceanography SC Meteorology & Atmospheric Sciences; Oceanography GA HY251 UT WOS:A1992HY25100007 ER PT J AU KOTECKI, DJ SIEWERT, TA AF KOTECKI, DJ SIEWERT, TA TI WRC-1992 CONSTITUTION DIAGRAM FOR STAINLESS-STEEL WELD METALS - A MODIFICATION OF THE WRC-1988 DIAGRAM SO WELDING JOURNAL LA English DT Article AB To increase the scope and accuracy of Ferrite Number (FN) prediction in stainless steel weld metal and related dissimilar metal joints, a modification of the Welding Research Council 1988 diagram (WRC-1988 diagram) is proposed. The proposed WRC-1992 diagram includes a coefficient for Cu in the Ni equivalent, thereby removing a tendency for the WRC-1988 diagram to overestimate the FN of weld metals when the Cu content is high. Also, the axes of the WRC-1992 diagram can be extended (as in the Schaeffler diagram) to predict dilution effects in dissimilar metal joints. C1 NAT INST STAND & TECHNOL,DIV MAT RELIABIL,BOULDER,CO. RP KOTECKI, DJ (reprint author), LINCOLN ELECT CO,STAINLESS & HIGH ALLOY PROD DEV,CLEVELAND,OH, USA. NR 13 TC 101 Z9 101 U1 0 U2 7 PU AMER WELDING SOC PI MIAMI PA PO BOX 351040, MIAMI, FL 33135 SN 0043-2296 J9 WELD J JI Weld. J. PD MAY PY 1992 VL 71 IS 5 BP S171 EP S178 PG 8 WC Metallurgy & Metallurgical Engineering SC Metallurgy & Metallurgical Engineering GA HR966 UT WOS:A1992HR96600017 ER PT J AU ANDREEVA, N DILL, J GILLILAND, GL AF ANDREEVA, N DILL, J GILLILAND, GL TI CAN ENZYMES ADOPT A SELF-INHIBITED FORM - RESULTS OF X-RAY CRYSTALLOGRAPHIC STUDIES OF CHYMOSIN SO BIOCHEMICAL AND BIOPHYSICAL RESEARCH COMMUNICATIONS LA English DT Article ID ASPARTIC PROTEINASE; RHIZOPUS-CHINENSIS; 1.8-A RESOLUTION; 3-DIMENSIONAL STRUCTURE; ACTIVE-SITE; PENICILLOPEPSIN; BINDING; DIFFRACTION; REFINEMENT; PEPSTATIN C1 MARYLAND BIOTECHNOL INST,CTR ADV RES BIOTECHNOL,9600 GUDELSKY DR,ROCKVILLE,MD 20899. VA ENGELHARDT INST MOLEC BIOL,MOSCOW 117984,USSR. NATL INST STAND & TECHNOL,ROCKVILLE,MD 20899. NR 27 TC 24 Z9 24 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 0006-291X J9 BIOCHEM BIOPH RES CO JI Biochem. Biophys. Res. Commun. PD APR 30 PY 1992 VL 184 IS 2 BP 1074 EP 1081 DI 10.1016/0006-291X(92)90701-L PG 8 WC Biochemistry & Molecular Biology; Biophysics SC Biochemistry & Molecular Biology; Biophysics GA HR526 UT WOS:A1992HR52600077 PM 1575726 ER PT J AU GERASIMOWICZ, WV GARROWAY, AN MILLER, JB SANDER, LC AF GERASIMOWICZ, WV GARROWAY, AN MILLER, JB SANDER, LC TI MULTIPLE-QUANTUM NMR-STUDIES OF MONOMERIC BONDED SILICA PHASES SO JOURNAL OF PHYSICAL CHEMISTRY LA English DT Article ID LIQUID-CHROMATOGRAPHY; ORGANIZATION; SOLIDS AB Covalently modified, bonded silica phases have been characterized by proton multiple-quantum (MQ) nuclear magnetic resonance (NMR) spectrometry. In the case of trimethylsilyl bonded phases, the loading has been shown to be homogeneous in that MQ coherence development plateaus at a value of approximately 10 correlated protons. Thus, at room temperature the MQ-NMR spin "counting" result is consistent with the fact that trimethylsilyl groups have 9 protons. The groups are dispersed such that intermolecular dipolar interactions are minimal, and the protons of individual trimethyl groups are behaving collectively as isolated clusters. Similar results are presented for a C8 monomeric phase (at -101-degrees-C) where isolated clusters of approximately 25 protons have been detected, and 23 are seen on the individual groups of the C8 monomeric phase. The mobility of the alkyl chain has been shown to vary depending upon the structure of the immobilized ligand. At room temperature the mobility of the C8 alkyl chain groups reduces the dipolar interaction among its protons. Therefore, MQ-NMR was run at the lower temperature to limit molecular motion while enhancing proton dipolar coupling. C1 NATL INST STANDARDS & TECHNOL,DIV ORGAN ANALYT RES,GAITHERSBURG,MD 20899. USDA ARS,EASTERN REG RES CTR,PHILADELPHIA,PA 19118. RP GERASIMOWICZ, WV (reprint author), USN,RES LAB,DIV CHEM,CODE 6122,WASHINGTON,DC 20375, USA. NR 17 TC 7 Z9 7 U1 0 U2 0 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 SN 0022-3654 J9 J PHYS CHEM-US JI J. Phys. Chem. PD APR 30 PY 1992 VL 96 IS 9 BP 3658 EP 3661 DI 10.1021/j100188a020 PG 4 WC Chemistry, Physical SC Chemistry GA HR490 UT WOS:A1992HR49000020 ER PT J AU WOLFE, R GYORGY, EM LIEBERMAN, RA FRATELLO, VJ LICHT, SJ DEETER, MN DAY, GW AF WOLFE, R GYORGY, EM LIEBERMAN, RA FRATELLO, VJ LICHT, SJ DEETER, MN DAY, GW TI HIGH-FREQUENCY MAGNETIC-FIELD SENSORS BASED ON THE FARADAY-EFFECT IN GARNET THICK-FILMS SO APPLIED PHYSICS LETTERS LA English DT Article AB The Faraday effect in the thick epitaxial films of magnetic garnets of the type used in magneto-optic isolators can be used as the basis for a fiber-optic magnetic field sensor. These films have uniaxial anisotropy perpendicular to the surface and they contain bismuth to enhance the Faraday rotation. The typical magnetic domain pattern of meandering stripes changes in response to an applied field perpendicular to the film and this changes the polarization of infrared light propagating perpendicular to the film. Theory and experiment show that the speed of operation is limited by relaxation or resonance effects to upper frequencies between 10(6) and 10(9) Hz. Maximum sensitivity requires low magnetic moment and large thickness, in conflict with the requirements for high speed. C1 NATL INST STAND & TECHNOL,BOULDER,CO 80303. RP WOLFE, R (reprint author), AT&T BELL LABS,MURRAY HILL,NJ 07974, USA. RI Deeter, Merritt/O-6078-2016 OI Deeter, Merritt/0000-0002-3555-0518 NR 9 TC 20 Z9 20 U1 0 U2 8 PU AMER INST PHYSICS PI WOODBURY PA CIRCULATION FULFILLMENT DIV, 500 SUNNYSIDE BLVD, WOODBURY, NY 11797-2999 SN 0003-6951 J9 APPL PHYS LETT JI Appl. Phys. Lett. PD APR 27 PY 1992 VL 60 IS 17 BP 2048 EP 2050 DI 10.1063/1.107110 PG 3 WC Physics, Applied SC Physics GA HQ500 UT WOS:A1992HQ50000002 ER PT J AU KRANBUEHL, DE VERDIER, PH AF KRANBUEHL, DE VERDIER, PH TI DIMENSIONS OF MODEL POLYMER-CHAINS WITH VARIABLE EXCLUDED VOLUME SO MACROMOLECULES LA English DT Note ID RENORMALIZATION C1 NATL INST STAND & TECHNOL,DIV POLYMERS,GAITHERSBURG,MD 20899. COLL WILLIAM & MARY,DEPT CHEM,WILLIAMSBURG,VA 23187. NR 14 TC 3 Z9 3 U1 0 U2 0 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 SN 0024-9297 J9 MACROMOLECULES JI Macromolecules PD APR 27 PY 1992 VL 25 IS 9 BP 2557 EP 2558 DI 10.1021/ma00035a040 PG 2 WC Polymer Science SC Polymer Science GA HR586 UT WOS:A1992HR58600040 ER PT J AU TOGGWEILER, JR AF TOGGWEILER, JR TI CARBON-CYCLE - CATALYTIC CONVERSIONS SO NATURE LA English DT Editorial Material ID OXIDATION METHOD; SEAWATER RP TOGGWEILER, JR (reprint author), PRINCETON UNIV,NOAA,GEOPHYS FLUID DYNAM LAB,POB 308,PRINCETON,NJ 08542, USA. NR 11 TC 22 Z9 23 U1 0 U2 0 PU MACMILLAN MAGAZINES LTD PI LONDON PA PORTERS SOUTH, 4 CRINAN ST, LONDON, ENGLAND N1 9XW SN 0028-0836 J9 NATURE JI Nature PD APR 23 PY 1992 VL 356 IS 6371 BP 665 EP 666 DI 10.1038/356665a0 PG 2 WC Multidisciplinary Sciences SC Science & Technology - Other Topics GA HQ146 UT WOS:A1992HQ14600035 ER PT J AU OVERPECK, JT AF OVERPECK, JT TI GLOBAL BIOMASS BURNING - ATMOSPHERIC, CLIMATIC, AND BIOSPHERIC IMPLICATIONS - LEVINE,JS SO NATURE LA English DT Book Review RP OVERPECK, JT (reprint author), NOAA,PALEOCLIMATOL PROGRAM,CTR GEOPHYS DATA,325 BROADWAY,BOULDER,CO 80303, USA. NR 1 TC 0 Z9 0 U1 2 U2 9 PU MACMILLAN MAGAZINES LTD PI LONDON PA PORTERS SOUTH, 4 CRINAN ST, LONDON, ENGLAND N1 9XW SN 0028-0836 J9 NATURE JI Nature PD APR 23 PY 1992 VL 356 IS 6371 BP 670 EP 670 DI 10.1038/356670a0 PG 1 WC Multidisciplinary Sciences SC Science & Technology - Other Topics GA HQ146 UT WOS:A1992HQ14600043 ER PT J AU MEOTNER, M AF MEOTNER, M TI INTERMOLECULAR FORCES IN ORGANIC CLUSTERS SO JOURNAL OF THE AMERICAN CHEMICAL SOCIETY LA English DT Article ID PHASE ION EQUILIBRIA; PRESSURE MASS-SPECTROMETRY; GAS-PHASE; HYDROGEN-BOND; THERMOCHEMICAL PROPERTIES; ISOMERIC CLUSTERS; PROTON AFFINITIES; CONDENSED-PHASE; DIMETHYL ETHER; SOLVENT SHELLS AB The effects of alkyl groups on the binding energies of cluster ions were investigated. The data were obtained by variable-temperature pulsed high-pressure mass spectrometric equilibrium measurements on protonated clusters A(n)H+ (A = MeOH, n-PrOH, n-AmOH, MeCOOH, MeNH2, n-PrNH2, and Me2NH). Inner shell binding energies are not affected by alkylation, suggesting pure hydrogen-bonding interactions with the core ions. Shell-filling effects are also not affected. Thus, going to the second shell causes an equal drop of 17 +/- 4 kJ/mol (4 +/- 1 kcal/mol) in all the observed clusters, despite the variation in the number of hydrogen-bonding sites and charge densities at the core ions. This suggests opposing effects of intramolecular and intermolecular solvation at the shell-filling step. However, the alkyl groups do affect the outer shells. The bonding energies in the outer shells of the alcohol clusters approach the respective bulk condensation energies within +/- 6 kJ/mol (+/- 1.5 kcal/mol). This suggests liquidlike hydrophobic alkyl-alkyl interactions in the outer shells which may contribute 12-25 kJ/mol (3-6 kcal/mol) to the bonding energies. RP NATL INST STAND & TECHNOL, DIV CHEM KINET & THERMODYNAM, GAITHERSBURG, MD 20899 USA. NR 67 TC 44 Z9 44 U1 0 U2 7 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 0002-7863 J9 J AM CHEM SOC JI J. Am. Chem. Soc. PD APR 22 PY 1992 VL 114 IS 9 BP 3312 EP 3322 DI 10.1021/ja00035a024 PG 11 WC Chemistry, Multidisciplinary SC Chemistry GA HQ814 UT WOS:A1992HQ81400024 ER PT J AU DULK, GA KIPLINGER, AL WINGLEE, RM AF DULK, GA KIPLINGER, AL WINGLEE, RM TI CHARACTERISTICS OF HARD X-RAY-SPECTRA OF IMPULSIVE SOLAR-FLARES SO ASTROPHYSICAL JOURNAL LA English DT Article DE SUN FLARES; SUN X-RAYS, GAMMA-RAYS; X-RAYS BURSTS ID ACCELERATION; ELECTRONS; EMISSION; PLASMA; PHASE AB We study the spectral characteristics of 93 impulsive, hard X-ray flares that were observed by the hard X-ray burst spectrometer (HXRBS) on the Solar Maximum Mission (SMM) spacecraft. Our major findings are as follows (1) During the initial few seconds after onset of rapidly rising bursts (i.e., rise times less-than-or-similar-to 5 s), there is a "high-energy delay," where the rise in flux at energies greater-than-or-similar-to 150 keV is delayed by a few seconds relative to that at energies less-than-or-similar-to 100 keV. (2) At the times of peak flux, the power-law spectra almost always "break downward" at an energy of approximately 100 keV, i.e., the spectra at higher energies are steeper than those at lower energies. There is little or no dependence of break energy upon the hard X-ray flux. (3) During the decay phase of bursts, the slopes of the power-law distributions at high and low energies change or cross over in such a way that the overall spectrum assumes the form of either a single power law or a broken power law that breaks up. The break energies of the spectra are usually lower after the crossover, but in approximately 30% of the cases they are higher. We relate our observational results to models of solar flares that invoke electric fields as a particle acceleration mechanism. In this context, our results imply that (a) the electric fields commonly have a potential drop of 150-200 keV, (b) another process (possibly stochastic acceleration by waves generated in association with the particle dynamics) produces the electrons of greater-than-or-similar-to 200 keV, and this process requires a few seconds to operate, and (c) as bursts decay the electric field disappears and the electron distribution evolves to a simple power law, or one that breaks up because of the preferential loss of electrons of E less-than-or-similar-to 100 keV, caused by collisions or by cyclotron maser radiation. C1 OBSERV PARIS,DASOP,F-92190 MEUDON,FRANCE. NOAA,SPACE ENVIRONM LAB,BOULDER,CO 80303. RP DULK, GA (reprint author), UNIV COLORADO,DEPT ASTROPHYS PLANETARY & ATMOSPHER SCI,BOULDER,CO 80309, USA. NR 27 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 APR 20 PY 1992 VL 389 IS 2 BP 756 EP 763 DI 10.1086/171248 PN 1 PG 8 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA HP119 UT WOS:A1992HP11900027 ER PT J AU FRIEDMAN, I SMITH, GI GLEASON, JD WARDEN, A HARRIS, JM AF FRIEDMAN, I SMITH, GI GLEASON, JD WARDEN, A HARRIS, JM TI STABLE ISOTOPE COMPOSITION OF WATERS IN SOUTHEASTERN CALIFORNIA .1. MODERN PRECIPITATION SO JOURNAL OF GEOPHYSICAL RESEARCH-ATMOSPHERES LA English DT Article ID SIERRA-NEVADA AREA; METEOROLOGICAL DATA; DEUTERIUM CONTENT; RESOLUTION; LAKES; SNOW AB Over a 7-year period from April 1982 to April 1989, integrated samples of rain and snow were collected at 32 sites by oil-sealed storage gage stations in (and adjoining) the southeast California desert; station elevations ranged from -65 m to 2280 m, and the collection network covered an area measuring about 400 km in each dimension. Deuterium (delta-D) analysis of 406 samples shows that the average delta-D of summer precipitation was -56 per mil (parts per thousand), whereas winter values averaged -78 parts per thousand; averaged annual values were close to -69 parts per thousand because most of the area is in a winter-dominated precipitation regime. We found no correlation between wetness or dryness of a season and the delta-D of its precipitation. The delta-O-18 versus delta-D plots show that rain samples define a tine of slope 6.5, less than the 8 of the Meteoric Water Line, whereas snow samples define a tine of slope 9.2. These differences in slope are the result of isotopic fractionation which occurred during evaporation of raindrops but not during sublimation of snow. Trajectory plots of 68 of the major storm events show that all of the winter storms originated in the Pacific, and passed over high mountains before reaching our collection stations. However, 21 of the 30 summer storms had trajectories that originated either over the Gulf of Mexico or the subtropical Pacific and traveled either west or north to reach our stations, without traversing high mountains. The difference in delta-D between winter and summer precipitation is due to different air flow patterns during those seasons. C1 US GEOL SURVEY, MENLO PK, CA 94025 USA. NOAA, CLIMATE MONITORING & DIAGNOST LAB, BOULDER, CO 80303 USA. RP FRIEDMAN, I (reprint author), US GEOL SURVEY, DENVER FED CTR, MS 963, DENVER, CO 80225 USA. NR 21 TC 110 Z9 115 U1 3 U2 21 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 1992 VL 97 IS D5 BP 5795 EP 5812 PG 18 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA HQ644 UT WOS:A1992HQ64400001 ER PT J AU KEY, J HAEFLIGER, M AF KEY, J HAEFLIGER, M TI ARCTIC ICE SURFACE-TEMPERATURE RETRIEVAL FROM AVHRR THERMAL CHANNELS SO JOURNAL OF GEOPHYSICAL RESEARCH-ATMOSPHERES LA English DT Article ID INFRARED MEASUREMENTS; SPACE AB The relationship between AVHRR thermal radiances and the surface (skin) temperature of Arctic snow-covered sea ice is examined through forward calculations of the radiative transfer equation, providing an ice/snow surface temperature retrieval algorithm for the central Arctic Basin. Temperature and humidity profiles with cloud observations collected on an ice island during 1986-1987 are used. Coefficients that correct for atmospheric attenuation are given for three Arctic clear sky "seasons", as defined through statistical analysis of the daily profiles, for the NOAA 7, 9, and 11 satellites. Modeled directional snow emissivities, different in the two split-window (11 and 12-mu-m) channels, are used. While the sensor scan angle is included explicitly in the correction equation, its effect in the dry Arctic atmosphere is small, generally less than 0.1 K. Using the split-window channels and scan angle, the rms error in the estimated ice surface temperature (IST) is less than 0.1 K in all seasons. Inclusion of channel 3 (3.7-mu-m) during the winter decreases the rms error by less than 0.003 K. The seasonal dependence of the coefficients is important, with errors in the range of 0.1 - 0.6 K when coefficients from one season are used with data from another. Similarly, mixing coefficients and data from different satellites results in average errors from 0.1 to 1.0 K. Overall, employing the IST coefficients results in increased accuracy of up to 0.6 K over SST coefficients developed for the North Atlantic and the Greenland Sea areas. RP KEY, J (reprint author), UNIV COLORADO, NOAA, COOPERAT INST RES ENVIRONM SCI, DIV CRYOSPHR & POLAR PROCESSES, BOULDER, CO 80309 USA. RI Key, Jeffrey/F-5597-2010 OI Key, Jeffrey/0000-0001-6109-3050 NR 24 TC 83 Z9 87 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 APR 20 PY 1992 VL 97 IS D5 BP 5885 EP 5893 PG 9 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA HQ644 UT WOS:A1992HQ64400007 ER PT J AU FIOCCO, G CACCIANI, M DIGIROLAMO, P FUA, D AF FIOCCO, G CACCIANI, M DIGIROLAMO, P FUA, D TI STRATOSPHERIC CLOUDS AT SOUTH-POLE DURING 1988 .1. RESULTS OF LIDAR OBSERVATIONS AND THEIR RELATIONSHIP TO TEMPERATURE SO JOURNAL OF GEOPHYSICAL RESEARCH-ATMOSPHERES LA English DT Article ID ANTARCTIC OZONE HOLE; AIRBORNE LIDAR; AEROSOL; WINTER; CONDENSATION; PARTICLES; BALLOON; GROWTH AB An optical radar-lidar-has been operational at the Amundsen-Scott South Pole Station since summer 1987-1988. The observations were specially directed to the detection of aerosol layers and polar stratospheric clouds (PSCs). The lidar utilized a Nd-YAG laser followed by a second harmonic generator, and a 0.5-m diameter Cassegrain receiving telescope. Results obtained during the period May-October 1988 are summarized. Some 10,000 profiles of the lidar echoes, each the result of 1-min averaging. were obtained. Data sets consisting of profiles of the scattering ratio and of the backscattering cross section B(a), based on half-hour averaging, are presented. The data can be related to profiles of the atmospheric temperature T, usually obtained on a daily basis at South Pole. Stratifications appear to have two distinct types of structures: one structure shows only a modest variation with height; the other is characterized by sharp features, with large changes of the cross section with height. The basic results, the relationship between B(a) and T, and their statistical relevance are considered in this paper. The microphysical interpretation, the attribution of these structures to PSC Type I and Type II, respectively involving the condensation of nitric acid trihydrate and of water ice. and the seasonal evolution of the phenomena are treated in a companion paper. C1 NOAA, ENVIRONM RES LAB, CLIMATE DIAGNOST & MONITORING LAB, BOULDER, CO 80303 USA. CNR, IST FIS ATMOSFERA, ROME, ITALY. RP FIOCCO, G (reprint author), UNIV ROME LA SAPIENZA, DEPT PHYS, PIAZZALE ALDO MORO 2, I-00185 ROME, ITALY. NR 21 TC 8 Z9 8 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 1992 VL 97 IS D5 BP 5939 EP 5946 PG 8 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA HQ644 UT WOS:A1992HQ64400011 ER PT J AU HARRIS, JM TANS, PP DLUGOKENCKY, EJ MASARIE, KA LANG, PM WHITTLESTONE, S STEELE, LP AF HARRIS, JM TANS, PP DLUGOKENCKY, EJ MASARIE, KA LANG, PM WHITTLESTONE, S STEELE, LP TI VARIATIONS IN ATMOSPHERIC METHANE AT MAUNA-LOA-OBSERVATORY RELATED TO LONG-RANGE TRANSPORT SO JOURNAL OF GEOPHYSICAL RESEARCH-ATMOSPHERES LA English DT Article ID CARBON-DIOXIDE CONCENTRATION; METEOROLOGICAL DATA; VARIABILITY; AEROSOLS; TRAJECTORIES; SENSITIVITY; CLIMATOLOGY; UNCERTAINTY; RESOLUTION; BARROW AB Methane measurements, radon measurements, and air mass trajectories calculated for Mauna Loa Observatory (MLO) are examined to determine relationships among methane source/sink regions, flow patterns for MLO, and methane variations on the synoptic-to-seasonal scale. We present evidence that the methane seasonal cycle observed at MLO is in large part driven by seasonal variations in transport. Furthermore, the variability in methane mixing ratio at MLO is higher in winter than in summer because of greater variability in flow patterns. Ten-day back trajectories are classified according to wind speed and direction using cluster analysis to determine six typical transport regimes. The methane data are then grouped according to transport cluster. The median methane mixing ratio corresponding to tradewind flow was 17.2 ppbv (parts per billion by volume) lower than that corresponding to strong westerly flow. This difference is attributed to transport from source/sink regions, flow across the methane latitudinal gradient, and seasonality of flow patterns. Case studies utilizing individual trajectories and radon measurements to determine probable air parcel origins illustrate the effects of long-range transport on the methane mixing ratio at MLO. Changes in flow pattern from sink to source origins can result in a 50 ppbv rise in methane mixing ratio over a period of a few days. During winter, alternation of westerly winds, tradewinds and anticyclonically curving flows contributes to the large variability in the methane mixing ratio. During summer this variability is reduced with the cessation of strong westerly flows from methane source regions. In July and August, air parcels originate far from methane source regions and in the area of highest modeled OH concentration. At the same time, methane mixing ratios decrease to the lowest values for the year. In this way, the seasonality of flow patterns exerts a major influence on the observed seasonal cycle of methane at MLO. C1 UNIV COLORADO, NOAA, COOPERAT INST RES ENVIRONM SCI, BOULDER, CO 80309 USA. AUSTRALIAN NUCL SCI & TECHNOL ORG, MENAI, NSW 2234, AUSTRALIA. CSIRO, DIV ATMOSPHER RES, MORDIALLOC, VIC 31951, AUSTRALIA. RP HARRIS, JM (reprint author), NOAA, CLIMATE MONITORING & DIAGNOST LAB, 325 BROADWAY, BOULDER, CO 80303 USA. RI Steele, Paul/B-3185-2009 OI Steele, Paul/0000-0002-8234-3730 NR 37 TC 53 Z9 53 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 1992 VL 97 IS D5 BP 6003 EP 6010 PG 8 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA HQ644 UT WOS:A1992HQ64400018 ER PT J AU LURIA, M BOATMAN, JF HARRIS, J RAY, J STRAUBE, T CHIN, J GUNTER, RL HERBERT, G GERLACH, TM VANVALIN, CC AF LURIA, M BOATMAN, JF HARRIS, J RAY, J STRAUBE, T CHIN, J GUNTER, RL HERBERT, G GERLACH, TM VANVALIN, CC TI ATMOSPHERIC SULFUR-DIOXIDE AT MAUNA-LOA, HAWAII SO JOURNAL OF GEOPHYSICAL RESEARCH-ATMOSPHERES LA English DT Article ID ATLANTIC-OCEAN; TRANSPORT AB Measurements of sulfur dioxide (SO2) were made at the National Oceanic and Atmospheric Administration's Mauna Loa Observatory in Hawaii, during a 12-month period beginning in December 1988. SO2 concentrations varied from background levels of less than 0.05 ppbv to a maximum of 50 ppbv, during episodes that lasted from 2 to 24 hours. Emissions from the Kilauea crater, approximately 35 km southeast of the observatory at an elevation of about 1000 m above sea level (asl), and the current eruption at Puu O'o 50 km east-southeast, are the most likely sources for the higher concentrations. These episodes occurred 10-25 times each month, mostly during the day; peak concentrations were usually recorded at mid-day. The SO2 concentrations can be grouped into three periods; low (June-September), high (October-January) and intermediate (February-May). A clear diurnal cycle of SO2 concentration exists throughout the year, although day-night changes were greatest during October-January and were barely detectable during the June-September period. The highest SO2 concentrations were recorded when the predominant wind direction was northerly to northwesterly, even though the apparent sources are in the southeastern sector. Nighttime concentrations were usually at background levels; however, many exceptions were observed. A few cases of higher than background SO2 were observed when free tropospheric (FT) conditions were identified. The possibility that long-range transport was the cause for elevated SO2 concentrations under FT conditions was examined using air mass back trajectories analyses. The highest nighttime SO2 concentrations, under FT conditions, were observed during periods with slow easterly trajectories, and the lowest concentrations were found during westerly flows. Twenty-four nighttime free tropospheric events were recorded when the SO2 concentration exceeded 0.2 ppbv. During 18 of these episodes, unusually high CO2 concentrations were observed. C1 NOAA, ENVIRONM RES LAB, AIR RESOURCES LAB, AEROSOL RES SECT, BOULDER, CO 80303 USA. HEBREW UNIV JERUSALEM, DEPT ENVIRONM SCI, JERUSALEM, ISRAEL. NOAA, ENVIRONM RES LAB, CLIMATE MONITORING & DIAGNOST LAB, BOULDER, CO 80303 USA. NOAA, ENVIRONM RES LAB, CLIMATE MONITORING & DIAGNOST LAB, MAUNA LOA OBSERV, HILO, HI USA. US GEOL SURVEY, DENVER FED CTR, DENVER, CO 80225 USA. NR 26 TC 14 Z9 15 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 1992 VL 97 IS D5 BP 6011 EP 6022 PG 12 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA HQ644 UT WOS:A1992HQ64400019 ER PT J AU CHAMEIDES, WL FEHSENFELD, F RODGERS, MO CARDELINO, C MARTINEZ, J PARRISH, D LONNEMAN, W LAWSON, DR RASMUSSEN, RA ZIMMERMAN, P GREENBERG, J MIDDLETON, P WANG, T AF CHAMEIDES, WL FEHSENFELD, F RODGERS, MO CARDELINO, C MARTINEZ, J PARRISH, D LONNEMAN, W LAWSON, DR RASMUSSEN, RA ZIMMERMAN, P GREENBERG, J MIDDLETON, P WANG, T TI OZONE PRECURSOR RELATIONSHIPS IN THE AMBIENT ATMOSPHERE SO JOURNAL OF GEOPHYSICAL RESEARCH-ATMOSPHERES LA English DT Article ID INCREMENTAL HYDROCARBON REACTIVITY; BOUNDARY-LAYER; UNITED-STATES; NITROGEN-OXIDES; SURFACE OZONE; AMAZON BASIN; PEROXYACETYL NITRATE; NORTH PACIFIC; NITRIC-OXIDE; NIWOT RIDGE AB The concentrations of ozone, nitrogen oxides, and nonmethane hydrocarbons measured near the surface in a variety of urban, suburban, rural, and remote locations are analyzed and compared in order to elucidate the relationships between ozone, its photochemical precursors, and the sources of these precursors. While a large gradient is found among remote, rural, and urban/suburban nitrogen oxide concentrations, the total hydrocarbon reactivity in all continental locations is found to be comparable. Apportionment of the observed hydrocarbon species to mobile and stationary anthropogenic sources and biogenic sources suggests that present-day emission inventories for the United States underestimate the size of mobile emissions. The analysis also suggests a significant role for biogenic hydrocarbon emissions in many urban/suburban locations and a dominant role for these sources in rural areas of the eastern United States. As one moves from remote locations to rural locations and then from rural to urban/suburban locations, ozone and nitrogen oxide concentrations tend to increase in a consistent manner while total hydrocarbon reactivity does not. C1 NOAA, ENVIRONM RES LAB, BOULDER, CO 80303 USA. NATL CTR ATMOSPHER RES, BOULDER, CO 80307 USA. CALIF AIR RESOURCES BOARD, DIV RES, SACRAMENTO, CA 95812 USA. US EPA, AREAL, RES TRIANGLE PK, NC 27711 USA. SUNY ALBANY, ATMOSPHER SCI RES CTR, ALBANY, NY 12222 USA. OREGON GRAD CTR, BEAVERTON, OR USA. RP CHAMEIDES, WL (reprint author), GEORGIA INST TECHNOL, DEPT EARTH & ATMOSPHER SCI, ATLANTA, GA 30332 USA. RI Parrish, David/E-8957-2010; Fehsenfeld, Frederick/I-4876-2013; WANG, Tao/B-9919-2014 OI Parrish, David/0000-0001-6312-2724; WANG, Tao/0000-0002-4765-9377 NR 71 TC 441 Z9 466 U1 9 U2 82 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 1992 VL 97 IS D5 BP 6037 EP 6055 PG 19 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA HQ644 UT WOS:A1992HQ64400021 ER PT J AU HAIR, DW HOBBIE, EK DOUGLAS, J HAN, CC AF HAIR, DW HOBBIE, EK DOUGLAS, J HAN, CC TI CRITICAL-DYNAMICS OF AN ASYMMETRIC BINARY POLYMER MIXTURE SO PHYSICAL REVIEW LETTERS LA English DT Article ID CRITICAL-POINT; DECAY-RATE; FLUCTUATIONS; LIQUID; FLUIDS AB The critical dynamics near the consolute point of a relatively low molecular weight asymmetric critical binary polymer mixture is studied with dynamic light scattering. In contrast to a single exponential decay showing a critical slowing down, as has been reported for another low molecular weight polymer blend, we observe both a "fast" and a "slow" relaxation rate. The critical slowing down of the concentration fluctuations is seen to be contained in these two modes. RP HAIR, DW (reprint author), NATL INST STAND & TECHNOL,DIV POLYMERS,MAT SCI & ENGN LAB,GAITHERSBURG,MD 20899, USA. RI Hobbie, Erik/C-8269-2013 NR 16 TC 33 Z9 33 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 APR 20 PY 1992 VL 68 IS 16 BP 2476 EP 2479 DI 10.1103/PhysRevLett.68.2476 PG 4 WC Physics, Multidisciplinary SC Physics GA HP801 UT WOS:A1992HP80100018 ER PT J AU HORN, RG SMITH, DT AF HORN, RG SMITH, DT TI CONTACT ELECTRIFICATION AND ADHESION BETWEEN DISSIMILAR MATERIALS SO SCIENCE LA English DT Article ID DISCHARGES; SURFACES; FORCES; MICA AB Simultaneous measurements of surface force and surface charge demonstrate strong attraction due to the spontaneous transfer of electrical charge from one smooth insulator (mica) to another (silica) as a result of simple, nonsliding contact in dry nitrogen. The measured surface charge densities are 5 to 20 millicoulombs per square meter after contact. The work required to separate the charged surfaces is typically 6 to 9 joules per square meter, comparable to the fracture energies of ionic-covalent materials. Observation of partial gas discharges when the surfaces are approximately 1 micrometer apart gives valuable insight into the charge separation processes underlying static electrical phenomena in general. RP HORN, RG (reprint author), NATL INST STAND & TECHNOL,DIV CERAM,GAITHERSBURG,MD 20899, USA. RI Horn, Roger/L-2782-2013; Smith, Douglas/I-4403-2016 OI Smith, Douglas/0000-0002-9358-3449 NR 19 TC 153 Z9 154 U1 8 U2 63 PU AMER ASSOC ADVANCEMENT SCIENCE PI WASHINGTON PA 1200 NEW YORK AVE, NW, WASHINGTON, DC 20005 SN 0036-8075 J9 SCIENCE JI Science PD APR 17 PY 1992 VL 256 IS 5055 BP 362 EP 364 DI 10.1126/science.256.5055.362 PG 3 WC Multidisciplinary Sciences SC Science & Technology - Other Topics GA HP032 UT WOS:A1992HP03200031 PM 17743112 ER PT J AU KUMAR, M NETA, P AF KUMAR, M NETA, P TI RADIOLYTIC REDUCTIONS AND OXIDATIONS IN DIMETHYL-SULFOXIDE SOLUTIONS - SOLVENT EFFECTS ON REACTIVITY OF HALOGEN ATOM COMPLEXES SO JOURNAL OF PHYSICAL CHEMISTRY LA English DT Article ID ONE-ELECTRON OXIDATION; PULSE-RADIOLYSIS; RATE CONSTANTS; HYDROGEN ABSTRACTION; FORMATION MECHANISM; PEROXYL RADICALS; AQUEOUS-SOLUTION; AROMATIC-AMINES; OH-RADICALS; YIELD AB Radiolysis of dimethyl sulfoxide (DMSO) solutions containing various additives was used to achieve clean one-electron reduction of oxidation of solutes. Pulse radiolysis of benzoquinone in DMSO solutions containing acetone and triethylamine permitted conversion of all primary radicals into reducing species. The total yield of reduction in the gamma-radiolysis of methyl viologen solutions was found to be 0.37-mu-mol/J. In the pulse radiolysis of TMPD and triphenylamine in aerated DMSO containing LiCl and/or CCl4, all the primary radicals were converted into oxidizing species and gave a maximum yield of 0.39-mu-mol/J. In the latter systems, oxidation was partly by halogen atom complexes. The reactivity of complexes of DMSO (DMSO.Cl, DMSO.Br) and of halide ions (Br2.-,I2.-) was examined for several organic compounds. DMSO.Cl oxidizes chlorpromazine, triphenylamine, and zinc porphyrin with rate constants of the order of 10(7)-10(8) M-1 s-1, and the rates increase upon addition of CH2Cl2 as well as upon addition of water and formamide. DMSO.Cl also reacts with olefins by addition of Cl to the double bond; the rate constants increase upon increasing the electron-donating properties of the substituents on the double bond. The rate constants for oxidation of chlorpromazine by Br2.- and I2.- increase by more than 2 orders of magnitude upon changing the solvent from DMSO gradually to water. The change was less with acetonitrile/water mixtures, and the difference is probably due to differences in ion solvation. C1 NATL INST STAND & TECHNOL,DIV CHEM KINET & THERMODYNAM,GAITHERSBURG,MD 20899. NR 35 TC 9 Z9 9 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 APR 16 PY 1992 VL 96 IS 8 BP 3350 EP 3354 DI 10.1021/j100187a032 PG 5 WC Chemistry, Physical SC Chemistry GA HQ013 UT WOS:A1992HQ01300032 ER PT J AU PADMAJA, S NETA, P HUIE, RE AF PADMAJA, S NETA, P HUIE, RE TI RATE CONSTANTS AND TEMPERATURE EFFECTS FOR REACTIONS OF CL2- WITH UNSATURATED ALCOHOLS AND HYDROCARBONS IN AQUEOUS AND ACETONITRILE WATER SOLUTIONS SO JOURNAL OF PHYSICAL CHEMISTRY LA English DT Article ID INORGANIC RADICALS; SULFATE; SO4; DEPENDENCE AB Absolute rate constants for reactions of the dichlorine radical anion, Cl2.-, with unsaturated alcohols and hydrocarbons have been measured at various temperatures. The alcohol reactions were measured in aqueous solutions and the hydrocarbon reactions in 1:1 aqueous acetonitrile (ACN) solutions. The rate constants for two alcohols and one hydrocarbon were also examined as a function of solvent composition. The room temperature rate constants varied between 10(6) and 10(9) M-1 s-1. The pre-exponential factors, A, were about (1-5) x 10(9) M-1 s-1 for the alcohols in aqueous solutions and about (0 1-1) x 10(9) M-1 s-1 for the hydrocarbons in aqueous ACN solutions. The activation energies, E(a), varied considerably, between 4 and 12 kJ mol-1 for the alcohols and between 2 and 8 kJ mol-1 for the hydrocarbons. The rate constants, k298, decrease with increasing ionization potential (IP) of the unsaturated compound, in agreement with an electrophilic addition mechanism. The activation energies for the unsaturated alcohols decrease when the IP decreases from 9.7 to 9.1 eV but appear to level off at lower IP. Most alkenes studied had IP < 9.1 eV and showed little change in E(a). Upon addition of ACN to the aqueous solution, the values of log k298 decreased linearly by more than 1 order of magnitude with increasing ACN mole fraction. This decrease appears to result from a combination of changes in the activation energy and in the pre-exponential factor. The reason for these changes may lie in changes in the solvation shell of the Cl2.- radical, which will affect the A factor, in combination with changes in solvation of Cl-, which will affect the energetics of the reactions as well. C1 NATL INST STAND & TECHNOL,DIV CHEM KINET & THERMODYNAM,GAITHERSBURG,MD 20899. RI Huie, Robert/A-5645-2010 NR 19 TC 12 Z9 14 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 APR 16 PY 1992 VL 96 IS 8 BP 3354 EP 3359 DI 10.1021/j100187a033 PG 6 WC Chemistry, Physical SC Chemistry GA HQ013 UT WOS:A1992HQ01300033 ER PT J AU RAVISHANKARA, AR TALUKDAR, R MELLOUKI, A AF RAVISHANKARA, AR TALUKDAR, R MELLOUKI, A TI REPORTED ERRORS IN THE RATE-CONSTANT FOR THE REACTION OH+CF3CF2H - REPLY SO JOURNAL OF PHYSICAL CHEMISTRY LA English DT Letter C1 UNIV COLORADO,NOAA,COOPERAT INST RES ENVIRONM SCI,BOULDER,CO 80309. RP RAVISHANKARA, AR (reprint author), NOAA,AERON LAB,325 BROADWAY,BOULDER,CO 80303, USA. RI TALUKDAR, RANAJIT/G-4530-2013; Ravishankara, Akkihebbal/A-2914-2011; Mellouki, Abdelwahid/H-5219-2011 OI TALUKDAR, RANAJIT/0000-0001-6017-8431; Mellouki, Abdelwahid/0000-0002-6594-5262 NR 3 TC 2 Z9 2 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 APR 16 PY 1992 VL 96 IS 8 BP 3561 EP 3562 DI 10.1021/j100187a070 PG 2 WC Chemistry, Physical SC Chemistry GA HQ013 UT WOS:A1992HQ01300070 ER PT J AU SARMIENTO, JL SUNDQUIST, ET AF SARMIENTO, JL SUNDQUIST, ET TI REVISED BUDGET FOR THE OCEANIC UPTAKE OF ANTHROPOGENIC CARBON-DIOXIDE SO NATURE LA English DT Article ID ORGANIC-CARBON; RIVER; MODEL AB TRACER-CALIBRATED models of the total uptake of anthropogenic CO2 by the world's oceans give estimates of about 2 gigatonnes carbon per year 1, significantly larger than a recent estimate 2 of 0.3-0.8 Gt C yr-1 for the synoptic air-to-sea CO2 influx. Although both estimates require that the global CO2 budget must be balanced by a large unknown terrestrial sink, the latter estimate implies a much larger terrestrial sink, and challenges the ocean model calculations on which previous CO2 budgets were based. The discrepancy is due in part to the net flux of carbon to the ocean by rivers and rain, which must be added to the synoptic air-to-sea CO2 flux to obtain the total oceanic uptake of anthropogenic CO2. Here we estimate the magnitude of this correction and of several other recently proposed adjustments to the synoptic air-sea CO2 exchange. These combined adjustments minimize the apparent inconsistency, and restore estimates of the terrestrial sink to values implied by the modelled oceanic uptake. C1 US GEOL SURVEY,WOODS HOLE,MA 02543. RP SARMIENTO, JL (reprint author), PRINCETON UNIV,ATMOSPHER & OCEAN SCI PROGRAM,PRINCETON,NJ 08544, USA. NR 33 TC 243 Z9 250 U1 4 U2 26 PU MACMILLAN MAGAZINES LTD PI LONDON PA PORTERS SOUTH, 4 CRINAN ST, LONDON, ENGLAND N1 9XW SN 0028-0836 J9 NATURE JI Nature PD APR 16 PY 1992 VL 356 IS 6370 BP 589 EP 593 DI 10.1038/356589a0 PG 5 WC Multidisciplinary Sciences SC Science & Technology - Other Topics GA HP031 UT WOS:A1992HP03100044 ER PT J AU TAHERI, B MUNOZ, A STJOHN, WD WICKSTED, JP POWELL, RC BLACKBURN, DH CRANMER, DC AF TAHERI, B MUNOZ, A STJOHN, WD WICKSTED, JP POWELL, RC BLACKBURN, DH CRANMER, DC TI EFFECTS OF THE STRUCTURE AND COMPOSITION OF LEAD GLASSES ON THE THERMAL LENSING OF PULSED LASER-RADIATION SO JOURNAL OF APPLIED PHYSICS LA English DT Article AB The thermal lensing characteristics of several silicate, germanate, phosphate, and borate glasses were studied using a laser with a 7 ns pulse at 457 nm in a tight focus geometry. A geometric model was developed to describe the quadratic radial profile of the refractive index resulting from the laser-induced temperature profile. This model was utilized to interpret the effects of some of the relevant experimental parameters on the fluence transmission experiments. The influence of material properties such as different types of network former and modifier ions on the nonlinear optical properties of these materials were also studied. It was found that: (i) the greatest influence of the network modifier ions was due to their effect on the absorption coefficient of the glasses; (ii) in lead glasses, the thermo-optic coeffients dn/dT of the germanates and silicates with random network structures were greater than those of the borate and phosphate glasses with ring and chain structures; and (iii) the main contribution to the thermo-optic coefficient comes from the thermally induced changes in the electronic polarizability of the glass components. In these glasses, the oxygen polarizability provides the dominant contribution and is affected by the variations in the polarizing power (charge to radius-squared ratio) of the network former ions. C1 NIST,GAITHERSBURG,MD 20890. RP TAHERI, B (reprint author), OKLAHOMA STATE UNIV,CTR LASER RES,STILLWATER,OK 74078, USA. NR 22 TC 16 Z9 16 U1 2 U2 4 PU AMER INST PHYSICS PI WOODBURY PA CIRCULATION FULFILLMENT DIV, 500 SUNNYSIDE BLVD, WOODBURY, NY 11797-2999 SN 0021-8979 J9 J APPL PHYS JI J. Appl. Phys. PD APR 15 PY 1992 VL 71 IS 8 BP 3693 EP 3700 DI 10.1063/1.350879 PG 8 WC Physics, Applied SC Physics GA HP366 UT WOS:A1992HP36600006 ER PT J AU NESBITT, DJ LOVEJOY, CM AF NESBITT, DJ LOVEJOY, CM TI RIGID BENDER ANALYSIS OF VANDERWAALS COMPLEXES - THE INTERMOLECULAR BENDING POTENTIAL OF A HYDROGEN-BOND SO JOURNAL OF CHEMICAL PHYSICS LA English DT Article ID MAGNETIC-RESONANCE SPECTROSCOPY; MICROWAVE ROTATIONAL SPECTRUM; FREQUENCY LASER SPECTROSCOPY; CONSISTENT FORCE FIELD; OXIDE-HF ISOMERS; INFRARED-SPECTRUM; VIBRATIONAL PREDISSOCIATION; ABSORPTION SPECTROSCOPY; HYPERFINE-STRUCTURE; MOLECULAR-SYSTEMS AB High resolution ir data on weakly bound OCOHF complexes formed in a slit supersonic expansion reveal a progression of extremely low frequency vibrational levels associated with the bending of the OCO-HF hydrogen bond. In a previous paper [J. Chem. Phys. 93, 7716 (1990)], we presented a spectroscopic analysis of the fundamental, combination and hot bands observed, corresponding to transitions between upsilon(bend)l = 0(0), 1(1), 2(0), 2(2), and 3(1), where upsilon(bend)l denotes quanta of OCOHF skeletal bend excitation with l units of vibrational angular momentum. In this paper, we analyze the rotationally resolved data in terms of the rigid bender formalism of Hougen, Bunker and Johns to determine an explicit angular potential, V(theta), for the OCOHF complex in both the HF ground (upsilon(HF) = 0) and vibrationally excited (upsilon(HF) = 1) state. The OCOHF ground state (upsilon(HF) = 0) potential is dominated by quartic and sextic angular terms, and thus is surprisingly shallow with respect to the bending angle. This quasilinear vibrational behavior is characterized by wide amplitude bending wave functions with zero point motion extending from -38-degrees to +38-degrees. In contrast, the OCOHF excited state (upsilon(HF) = 1) exhibits a significantly bent equilibrium geometry with a hydrogen bond bend angle of 31-degrees +/- 5-degrees, corresponding to a cylindrically symmetric, noncolinear minimum in the potential. This shift in equilibrium geometry upon upsilon(HF) excitation is quantitatively responsible for promoting DELTA-upsilon(bend) = 0,2,... combination band vibrational modes, in analogy with Franck-Condon progressions in a bent <-- linear electronic transition. The predissociation lifetimes for upsilon(HF) = 1 excited OCOHF vary systematically with upsilon(bend)l, and can be analyzed in terms of a geometry dependent predissociation rate which increases with bending of the hydrogen bond angle. These empirical bending potentials are in qualitative agreement with, but quantitatively much shallower than predicted by previous electrostatic and ab initio calculations, and differ fundamentally from the traditional notions of a relatively stiff, linear hydrogen bond. The present results on the hydrogen bond potential surface for O = C = O---HF are consistent with statistical analyses of -C = O---H-N hydrogen bond angles obtained from x-ray crystallographic studies of proteins. C1 NATL INST STAND & TECHNOL,BOULDER,CO. RP NESBITT, DJ (reprint author), UNIV COLORADO,JOINT INST LAB ASTROPHYS,BOULDER,CO 80309, USA. NR 67 TC 23 Z9 23 U1 1 U2 5 PU AMER INST PHYSICS PI WOODBURY PA CIRCULATION FULFILLMENT DIV, 500 SUNNYSIDE BLVD, WOODBURY, NY 11797-2999 SN 0021-9606 J9 J CHEM PHYS JI J. Chem. Phys. PD APR 15 PY 1992 VL 96 IS 8 BP 5712 EP 5725 DI 10.1063/1.462670 PG 14 WC Chemistry, Physical; Physics, Atomic, Molecular & Chemical SC Chemistry; Physics GA HN268 UT WOS:A1992HN26800018 ER PT J AU VAGHJIANI, GL TURNIPSEED, AA WARREN, RF RAVISHANKARA, AR AF VAGHJIANI, GL TURNIPSEED, AA WARREN, RF RAVISHANKARA, AR TI PHOTODISSOCIATION OF H2O2 AT 193 AND 222 NM - PRODUCTS AND QUANTUM YIELDS SO JOURNAL OF CHEMICAL PHYSICS LA English DT Article ID ABSORPTION CROSS-SECTIONS; VIBRATIONAL-RELAXATION; OH RADICALS; 248 NM; PHOTOLYSIS; CH3OOH; CH3SH; D2O2; PHOTOCHEMISTRY; TROPOSPHERE AB The primary quantum yields of OH(X(2)PI),H(2S), and oxygen atoms [O(1D) + O(3P)] produced in the photodissociation of H2O2 at 193 and 222 nm have been measured at 298 K. At 193 nm, the primary quantum yields were observed to be 1.51 +/- 0.18, 0.16 +/- 0.04, and < 0.02, for PHI(OH), PHI(H), and the sum of PHI(O) and PHI(O 1S), respectively. At 222 nm, the OH yield was PHI(OH) = 2.02 +/- 0.35, the H atom yield was PHI(H) = 0.024 +/- 0.012, and PHI(O) was < 0.002. The errors quoted above are 2-sigma, precision plus estimated systematic errors. The OH product was directly monitored by pulsed laser-induced fluorescence, and the atomic species were detected via cw resonance fluorescence. The OH quantum yields reported here were measured relative to known product quantum yields in the dissociation of H2O2 at 248 nm. H(2S) yields were measured relative to those in photolysis of HBr and HCl, (at 193 nm) or CH3SH (at 222 nm), whereas O atoms yields were measured relative to O3 photolysis at both wavelengths. The present results indicate unit dissociation of H2O2 at both 222 and 193 nm with only two major products OH (approximately 80% at 193 nm, 98% at 222 nm) and H(2S) (approximately 20% at 193 nm, 2% at 222 nm). Up to 15% of the OH produced in the 193 nm photolysis may be vibrationally excited; however, no evidence for vibrationally excited OH was observed at 222 nm. C1 NOAA, AERON LAB, BOULDER, CO 80303 USA. UNIV COLORADO, DEPT CHEM & BIOCHEM, BOULDER, CO 80309 USA. UNIV COLORADO, NOAA, COOPERAT INST RES ENVIRONM SCI, BOULDER, CO 80309 USA. RI Ravishankara, Akkihebbal/A-2914-2011 NR 44 TC 37 Z9 38 U1 0 U2 8 PU AMER INST PHYSICS PI MELVILLE PA CIRCULATION & FULFILLMENT DIV, 2 HUNTINGTON QUADRANGLE, STE 1 N O 1, MELVILLE, NY 11747-4501 USA SN 0021-9606 J9 J CHEM PHYS JI J. Chem. Phys. PD APR 15 PY 1992 VL 96 IS 8 BP 5878 EP 5886 DI 10.1063/1.462684 PG 9 WC Chemistry, Physical; Physics, Atomic, Molecular & Chemical SC Chemistry; Physics GA HN268 UT WOS:A1992HN26800033 ER PT J AU TURNIPSEED, AA VAGHJIANI, GL THOMPSON, JE RAVISHANKARA, AR AF TURNIPSEED, AA VAGHJIANI, GL THOMPSON, JE RAVISHANKARA, AR TI PHOTODISSOCIATION OF HNO3 AT 193, 222, AND 248 NM - PRODUCTS AND QUANTUM YIELDS SO JOURNAL OF CHEMICAL PHYSICS LA English DT Article ID NITRIC-ACID VAPOR; LASER PHOTOLYSIS; N2O5 PHOTOLYSIS; OH; ABSORPTION; KINETICS; FLUORESCENCE; MECHANISM; PRESSURE; SPECTRUM AB The quantum yields for OH, O(3P), O(1D), and H(2S) from the photolysis of HNO3 have been determined at 248, 222, and 193 nm at 298 K. The quantum yield for OH was observed to be near unity at 248 [PHI(OH) = 0.95 +/- 0.09] and 222 nm [PHI(OH) = 0.90 +/- 0.11]. However, at 193 nm the quantum yield for OH was found to be 0.33 +/- 0.06. The quantum yield for O atoms [O(3P) + O(1D)], PHI(O), was observed to be 0.031 +/- 0.010, 0.20 +/- 0.03, 0.81 +/- 0.13, at 248, 222, and 193 nm, respectively. Both O(3P) and O(1D) were observed at 222 and 193 nm, but only O(3P) was detected at 248 nm. It was observed that 40% of the O atoms formed at both 193 and 222 nm were O(1D) atoms. The upper limits for H(2S) quantum yields: PHI(H) less-than-or-equal-to 0.002 at 248 nm, less-than-or-equal-to 0.01 at 222 nm, and less-than-or-equal-to 0.012 at 193 nm were also determined. This present work quantifies the photolysis channel producing HONO + O and show that it accounts for a large fraction at HNO3 photolysis at 193 nm. C1 NOAA,AERON LAB,BOULDER,CO 80303. UNIV COLORADO,DEPT CHEM & BIOCHEM,BOULDER,CO 80309. UNIV COLORADO,NOAA,COOPERAT INST RES ENVIRONM SCI,BOULDER,CO 80309. RI Ravishankara, Akkihebbal/A-2914-2011 NR 31 TC 66 Z9 66 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 APR 15 PY 1992 VL 96 IS 8 BP 5887 EP 5895 DI 10.1063/1.462685 PG 9 WC Chemistry, Physical; Physics, Atomic, Molecular & Chemical SC Chemistry; Physics GA HN268 UT WOS:A1992HN26800034 ER PT J AU HAKKINEN, S MELLOR, GL KANTHA, LH AF HAKKINEN, S MELLOR, GL KANTHA, LH TI MODELING DEEP CONVECTION IN THE GREENLAND SEA SO JOURNAL OF GEOPHYSICAL RESEARCH-OCEANS LA English DT Article ID MARGINAL ICE-ZONE; OCEAN MODEL; BERING SEA; WATER; NORTH AB The development of deep convective events in the high-latitude ocean is studied using a three-dimensional, coupled ice-ocean model. Oceanic mixing is described according to the level 2.5 turbulence closure scheme in which convection occurs in a continuous way, i.e., convective adjustment is not invoked. The model is forced by strong winds and surface cooling. Strong upwelling at the multiyear ice edge and consequent entrainment of warm Atlantic waters into the mixed layer is produced by winds parallel to the ice edge. Concomitant cooling drives deep convection and produces chimneylike structures. Inclusion of a barotropic mean flow over topography to the model provides important preconditioning and selects the location of deep convection. The most efficient preconditioning occurs at locations where the flow ascends a slope. In a stratified environment similar to the Greenland Sea with a 12 m s-1 wind the model simulations show that localized deep convection takes place after about 10 days to depths of 1000 m. C1 PRINCETON UNIV,ATMOSPHER & OCEAN SCI PROGRAM,PRINCETON,NJ 08544. RI Hakkinen, Sirpa/E-1461-2012 NR 35 TC 19 Z9 19 U1 0 U2 2 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 SN 0148-0227 J9 J GEOPHYS RES-OCEANS JI J. Geophys. Res.-Oceans PD APR 15 PY 1992 VL 97 IS C4 BP 5389 EP 5408 DI 10.1029/92JC00061 PG 20 WC Oceanography SC Oceanography GA HQ256 UT WOS:A1992HQ25600018 ER PT J AU GARBOCZI, EJ BENTZ, DP AF GARBOCZI, EJ BENTZ, DP TI COMPUTER-SIMULATION OF THE DIFFUSIVITY OF CEMENT-BASED MATERIALS SO JOURNAL OF MATERIALS SCIENCE LA English DT Article ID TRANSPORT-PROPERTIES; TRICALCIUM SILICATE; CONTINUUM; HYDRATION AB A digital image-based model of the microstructure of cement paste, coupled with exact transport algorithms, is used to study the diffusivity of Portland cement paste. The principal variables considered are water:cement ratio, degree of cement hydration and capillary porosity. Computational methods are described and diffusivity results are presented, which are found to agree with the available experimental measurements within experimental error. Model cement pastes prepared with different water:cement ratios, and having different degrees of hydration, are found to have diffusivities that lie on a single master curve when plotted as a function of capillary porosity. Concepts from percolation theory are used to explain quantitatively the dependence of diffusivity on capillary porosity. The effect of silica fume addition on diffusivity is also examined. RP GARBOCZI, EJ (reprint author), NATL INST STAND & TECHNOL,DIV BLDG MAT 226-B348,GAITHERSBURG,MD 20899, USA. NR 34 TC 156 Z9 162 U1 2 U2 16 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 1992 VL 27 IS 8 BP 2083 EP 2092 DI 10.1007/BF01117921 PG 10 WC Materials Science, Multidisciplinary SC Materials Science GA HQ667 UT WOS:A1992HQ66700013 ER PT J AU XU, Q AF XU, Q TI FORMATION AND EVOLUTION OF FRONTAL RAINBANDS AND GEOSTROPHIC POTENTIAL VORTICITY ANOMALIES SO JOURNAL OF THE ATMOSPHERIC SCIENCES LA English DT Article ID MOIST SYMMETRIC STABILITY; CIRCULATIONS; INSTABILITY; FRONTOGENESIS; EQUATION; MODELS AB A viscous semigeostrophic model is developed and used to study the formation and evolution of frontal rainbands in association with the dry and moist geostrophic potential vorticity (GPV) anomalies. The numerical results show that when moist GPV (MGPV) becomes negative in the saturated region (but the flow is still stable to viscous symmetric perturbations), banded substructures can be generated internally by a positive feedback between the moist circulation bands and geostrophic forcing anomalies in association with the generation of mesoscale GPV anomalies. In addition to the previous diagnostic results for idealized forcings, the new aspect here is that the large-scale moist ascent evolves into much finer multiple moist bands as soon as the positive feedback begins to generate banded substructures in the forcing and GPV fields. When MGPV is positive, multiple rainbands can only be generated externally by preexisting GPV or MGPV anomalies. These rainbands can be self-maintained by a weak feedback between the vertical motion and warming anomalies that operates in a partially saturated layer between the maximum and minimum levels of the undulated cloud-base boundary in association with the preexisting GPV or MGPV anomalies. The bands are seen as weak cores of upward motion surrounded by the large-scale moist ascent, rather than separated by mesoscale dry subsidences as in the case of negative MGPV. As the negative MGPV area diminishes (mainly due to the boundary MGPV flux) and the GPV anomalies are lifted into the saturated region, the later evolution of the bands is largely controlled by the Lagrangian advection and eddy dissipation. As the geostrophic confluence flow squeezes (stretches) the bands toward (along) the front, the fine structures of GPV anomalies are smoothed by eddy viscosity, and multibands gradually "merge" into a larger single band of moist ascent. Rainbands produce not only horizontal-mean positive (negative) GPV anomalies in the lower (upper) levels but also significant mesoscale GPV anomalies in the horizontal. Boundary-layer processes can produce either positive or negative GPV flux, depending on the boundary conditions. In general, positive (negative) GPV flux is produced when warm (cold) air moves over a cold (warm) surface. The complex and yet somewhat subtle feature of GPV flux near the surface front is discussed in detail. C1 NOAA, ENVIRONM RES LAB, NATL SEVERE STORMS LAB, NORMAN, OK 73069 USA. RP UNIV OKLAHOMA, NOAA, COOPERAT INST MESOSCALE METEOROL STUDIES, 100 E BOYD, ROOM 110, NORMAN, OK 73019 USA. NR 27 TC 48 Z9 54 U1 0 U2 6 PU AMER METEOROLOGICAL SOC PI BOSTON PA 45 BEACON ST, BOSTON, MA 02108-3693 USA SN 0022-4928 EI 1520-0469 J9 J ATMOS SCI JI J. Atmos. Sci. PD APR 15 PY 1992 VL 49 IS 8 BP 629 EP 648 DI 10.1175/1520-0469(1992)049<0629:FAEOFR>2.0.CO;2 PG 20 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA HQ273 UT WOS:A1992HQ27300001 ER PT J AU GOZANI, J AF GOZANI, J TI WAVE-PROPAGATION IN AN INTERMITTENT QUASI-HOMOGENEOUS TURBULENT MEDIUM SO OPTICS LETTERS LA English DT Article AB A path integral solution for the statistical moments of a wave propagating in an intermittent random medium is proposed. The formulation suggests a tractable analytical model, useful for studying intermittent effects on wave propagation. Light is shed on related research problems such as the need for adequate models of intermittency and the lack of consistent measurements and conventions. RP GOZANI, J (reprint author), UNIV COLORADO,NOAA,COOPERAT INST RES ENVIRONM SCI,BOULDER,CO 80309, USA. NR 6 TC 9 Z9 10 U1 3 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 APR 15 PY 1992 VL 17 IS 8 BP 559 EP 561 DI 10.1364/OL.17.000559 PG 3 WC Optics SC Optics GA HM730 UT WOS:A1992HM73000003 PM 19794557 ER PT J AU CAMPBELL, GC VANDERHART, DL FENG, Y HAN, CC AF CAMPBELL, GC VANDERHART, DL FENG, Y HAN, CC TI PROTON NMR-STUDY OF THE INTIMACY OF MIXING IN A HYDROGEN-BONDED BLEND OF POLYSTYRENE AND POLY(BUTYL METHACRYLATE) SO MACROMOLECULES LA English DT Article ID MULTIPLE PULSE NMR; POLYMER BLENDS; SPIN DIFFUSION; MISCIBILITY; MORPHOLOGY; SOLIDS AB High-resolution solid-state proton NMR techniques were used to examine the mixing of polystyrene (PS) and poly(butyl methacrylate) (PBMA) chains in a blend where the PS was chemically modified by copolymerization with 1.5 mol % of a modified styrene monomer containing a hydroxyl group. Substitution of this modified PS(OH) polymer "compatibilizes" the otherwise incompatible PS/PBMA blend. Proton spin diffusion techniques were used to examine the level of mixing. Data indicated that there is compositional heterogeneity remaining in this 60/40 PS(OH)/PBMA blend on the 6-12-nm scale, a scale which is comparable to the mean separation between "decorations" on the unperturbed Gaussian PS chain. The compositional heterogeneity is such that the mean PS(OH)-proton fraction in the PS(OH)-rich regions is about 75% and likewise for the PBMA-proton fraction in the PMBA-rich regions. The level of mixing is deemed sufficiently intimate for imparting intermediate material properties to this blend. There is also evidence of some molecular-level mixing in the differential line broadening/line narrowing of PBMA/PS(OH) resonances in the blend spectrum. C1 NATL INST STAND & TECHNOL,DIV POLYMERS,GAITHERSBURG,MD 20899. NR 22 TC 10 Z9 10 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 13 PY 1992 VL 25 IS 8 BP 2107 EP 2111 DI 10.1021/ma00034a008 PG 5 WC Polymer Science SC Polymer Science GA HN935 UT WOS:A1992HN93500008 ER PT J AU GAN, Z BINTZ, L ANDERSON, DZ AF GAN, Z BINTZ, L ANDERSON, DZ TI FIBEROPTIC ACOUSTIC FOURIER TRANSDUCER FOR AUDIO SOUND PROCESSING SO APPLIED OPTICS LA English DT Article AB We demonstrate a fiber-optic acoustic transducer operating in the audio-frequency regime. The device is made of an array of 120 multimode optical fibers and a photorefractive novelty filter. Each fiber in the array acts as a cantilevered mechanical resonator. The resonant frequencies of the fibers logarithmically sample the acoustic spectrum from approximately 100 Hz to 5 kHz. Laser light is injected into all fibers simultaneously and is reflected from the end of each fiber. An optical novelty filter extracts the acoustic information from the reflected light. The output of the novelty filter is essentially a Fourier transform of the acoustic signal. The background intensity in the transducer output corresponds to a driving amplitude of approximately 50 angstrom. We describe holographic storage of complex sound patterns that use a LiNbO3 crystal and an acoustic transducer. C1 NATL INST STAND & TECHNOL,BOULDER,CO 80309. UNIV COLORADO,JOINT INST LAB ASTROPHYS,BOULDER,CO 80309. RP GAN, Z (reprint author), UNIV COLORADO,DEPT PHYS,BOULDER,CO 80309, USA. NR 13 TC 0 Z9 0 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 APR 10 PY 1992 VL 31 IS 11 BP 1740 EP 1744 PG 5 WC Optics SC Optics GA HM675 UT WOS:A1992HM67500011 ER PT J AU WYSS, M GILLARD, D LIANG, B AF WYSS, M GILLARD, D LIANG, B TI AN ESTIMATE OF THE ABSOLUTE STRESS TENSOR IN KAOIKI, HAWAII SO JOURNAL OF GEOPHYSICAL RESEARCH-SOLID EARTH LA English DT Article ID SAN-ANDREAS FAULT; KILAUEA VOLCANO; FLUID-PRESSURE; NOVEMBER 29; SOUTH FLANK; EARTHQUAKE; MECHANISM; DEFORMATION; FRICTION; KALAPANA AB The stress tensor orientation was calculated by inversion of 81 fault plane solutions of M = 3.5 +/- 0.6 earthquakes located in an area 6 by 16 km at depths of 7 +/- 2 km. This crustal volume is situated on a straight line between the summits of the active volcanoes Kilauea and Mauna Loa. The orientation of the greatest principal stress was found to be near horizontal and in the line connecting the two volcanoes. This is further evidence supporting the model that magmatic expansion within the feeding conduits of these volcanoes is the source of stress that causes earthquakes in southern Hawaii. These earthquakes are tectonic earthquakes in the sense that they occur in a brittle elastic crust at distances of a few to several tens of kilometers from the volcanoes, and that they are not directly associated with the opening of cracks by intrusions. We propose that this model leads to the corollary that the shear stresses (tau) responsible for earthquake failure in the shallow Hawaiian crust are approximately 3 +/- 2 MPa, and that the pore pressure of ground-water (p) in the hypocentral volume must be under near lithostatic pressure. This result is obtained by arguing that the greatest principal stress (sigma(1)) is equal to the magma pressure in the volcanic feeder pipe, but cannot exceed the least principal stress (sigma(3)) by more than the tensile strength of the crust, because otherwise hydrofracture would occur, opening a crack against the least principal stress. Given the difference between the greatest and least principal stress, the fact that the overburden at the 7 km hypocentral depth equals the intermediate principal stress and the ratio R = (sigma(1) - sigma(2))/(sigma(1) - sigma(3)) = 0.4, which is obtained in the inversion of fault plane solutions, we estimate that sigma(1) = 202 MPa, sigma(2) = 200 MPa, sigma(3) = 196 MPa, tau = 3 MPa, and sigma(n) = 199 MPa, with uncertainties on the order of several MPa. It follows that for any coefficients of friction larger than 0.15, the pore fluid pressure necessary for faulting on the observed fault planes has to be larger than 90% of the lithostatic pressure. These considerations suggest that many earthquakes represent fault ruptures under low ambient shear stresses in the order of the average observed stress drop of 3 MPa. C1 UNIV COLORADO,NOAA,COOPERAT INST RES ENVIRONM SCI,BOULDER,CO 80309. NR 55 TC 19 Z9 23 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-SOL EA JI J. Geophys. Res.-Solid Earth PD APR 10 PY 1992 VL 97 IS B4 BP 4763 EP 4768 DI 10.1029/91JB01455 PG 6 WC Geochemistry & Geophysics SC Geochemistry & Geophysics GA HQ336 UT WOS:A1992HQ33600028 ER PT J AU WYSS, M LIANG, BY TANIGAWA, WR WU, XP AF WYSS, M LIANG, BY TANIGAWA, WR WU, XP TI COMPARISON OF ORIENTATIONS OF STRESS AND STRAIN TENSORS BASED ON FAULT PLANE SOLUTIONS IN KAOIKI, HAWAII SO JOURNAL OF GEOPHYSICAL RESEARCH-SOLID EARTH LA English DT Article ID FOCAL MECHANISM DATA; SAN-ANDREAS FAULT; MS = 6.6; REGIONAL STRESS; KILAUEA VOLCANO; EARTHQUAKE; DEFORMATION; RATES; SEISMICITY; TECTONICS AB The stress tensor orientation was estimated based on inversion from 238 first motion fault plan solutions of earthquakes with mostly M = 3.5 +/- 0.6 located in the 10-km radius Kaoiki crustal volume. Separate inversions for subvolumes containing 20-50 events yielded the same results in several adjacent volumes, suggesting that the stress tensor is homogeneous in those parts of the Kaoiki area and that the inversion results are stable and meaningful. Five spatial subsets of the data were found for which the orientation of at least one of the principal axes was different from that in the other sets by 20-degrees-80-degrees and at confidence levels exceeding 95%. The volcano summits of Kilauea and Mauna Loa, and their rift systems, are identified as the source of stress in the Kaoiki crust, because the greatest principal stress points to Kilauea and Mauna Loa. In addition, the strain tensor due to energy released by these 238 earthquakes was computed for the Kaoiki area, and several subvolumes of it, by summing the moment tensors. The moment tensor of each earthquake was constructed from the individual fault plane solutions and from an estimate of the scalar moment derived from the moment-magnitude relationship. A comparison of the directions of strain and stress tensors showed close agreement for subvolumes with predominantly strike-slip faulting. In these volumes the inversion process for stress directions led to misfits of approximately equal size for the conjugate near vertical nodal planes. These observations are interpreted to show that in the strike-slip regime of the upper part of the crust, neither of the nodal planes is preferred for faulting. Rupture probably occurs along the NW and along the NE striking nodal planes in separate earthquakes. Subvolumes with more decollement faulting showed significant differences of 30-degrees-40-degrees between the principal strain and stress directions. In these volumes the near-horizontal nodal planes showed noticeably smaller misfits in the inversion for the stress directions. These facts are interpreted to indicate that the decollement plane is weak, allowing slip on it even if the principal stresses are inclined at a large angle to it. It is proposed that comparison of strain and stress tensor calculations may be able to differentiate between tectonic regimes uniform in strength (no well developed fault plane) and regimes in which a fault with low frictional strength dominates. As a function of time, significant rotations of the strain tensor by approximately 45-degrees can be observed, which seem to be related to the occurrences of Kaoiki mainshocks. During three background periods of about 7 years each, the average strain tensor showed an orientation typical for predominant decollement faulting, while two premainshock periods of 2.5 years each showed an orientation closer to strike-slip faulting. It is proposed that this pattern may be repeated before the next Kaoiki mainshock. The strain released seismically is less than the geodetically observed strain by approximately an order of magnitude. C1 UNIV COLORADO,NOAA,COOPERAT INST RES ENVIRONM SCI,BOULDER,CO 80309. UNIV COLORADO,DEPT GEOL SCI,BOULDER,CO 80309. US GEOL SURVEY,HAWAIIAN VOLCANO OBSERV,HAWAII NATL PK,HI 96718. UNIV COLORADO,JOINT INST LAB ASTROPHYS,BOULDER,CO 80309. NR 48 TC 95 Z9 97 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-SOL EA JI J. Geophys. Res.-Solid Earth PD APR 10 PY 1992 VL 97 IS B4 BP 4769 EP 4790 DI 10.1029/91JB02968 PG 22 WC Geochemistry & Geophysics SC Geochemistry & Geophysics GA HQ336 UT WOS:A1992HQ33600029 ER PT J AU LARSEN, S REILINGER, R NEUGEBAUER, H STRANGE, W AF LARSEN, S REILINGER, R NEUGEBAUER, H STRANGE, W TI GLOBAL POSITIONING SYSTEM MEASUREMENTS OF DEFORMATIONS ASSOCIATED WITH THE 1987 SUPERSTITION HILLS EARTHQUAKE - EVIDENCE FOR CONJUGATE FAULTING SO JOURNAL OF GEOPHYSICAL RESEARCH-SOLID EARTH LA English DT Article ID 24 NOVEMBER 1987; MOMENT-TENSOR SOLUTIONS; SAN-ANDREAS FAULT; CRUSTAL DEFORMATION; SOUTHERN-CALIFORNIA; DISPLACEMENT-FIELDS; RUPTURE PROCESS; PLATE MOTIONS; GEODETIC DATA; SLIP AB Large station displacements observed from Imperial Valley global positioning system (GPS) campaigns are attributed to the November 24, 1987, Superstition Hills earthquake sequence. Thirty sites from a 42-station GPS network established in 1986 have been reoccupied during 1988 and/or 1990. Displacements at three sites within 3 km of the surface rupture approach 0.5 m. Eight additional stations within 20 km of the seismic zone are displaced at least 10 cm. This is the first occurrence of a large earthquake (M(S) 6.6) within a preexisting GPS network. Best-fitting uniform slip models of rectangular dislocations in an elastic half-space indicate 130 +/- 8 cm right-lateral displacement along the northwest-trending Superstition Hills fault and 30 +/- 10 cm left-lateral displacement along the conjugate northeast-trending Elmore Ranch fault. The geodetic moments are 9.4 x 10(25) dyn cm and 2.3 x 10(25) dyn cm for the Superstition Hills and Elmore Ranch faults, respectively, consistent with teleseismic source parameters. The data also suggest that posteseismic slip along the Superstition Hills fault is concentrated at shallow depths. Distributed slip solutions using singular value decomposition indicate near uniform displacement along the Elmore Ranch fault and concentrated slip to the northwest and southeast along the Superstition Hills fault. A significant component of nonseismic secular displacement is observed across the Imperial Valley, which is attributed to interseismic plate-boundary deformation. C1 NOAA,NATL GEODET SURVEY,ROCKVILLE,MD 20852. MIT,EARTH RESOURCES LAB,CAMBRIDGE,MA 02139. CALTECH,SEISMOL LAB,PASADENA,CA 91125. NR 72 TC 35 Z9 36 U1 1 U2 2 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 SN 0148-0227 J9 J GEOPHYS RES-SOL EA JI J. Geophys. Res.-Solid Earth PD APR 10 PY 1992 VL 97 IS B4 BP 4885 EP 4902 DI 10.1029/92JB00128 PG 18 WC Geochemistry & Geophysics SC Geochemistry & Geophysics GA HQ336 UT WOS:A1992HQ33600036 ER PT J AU MACDONALD, RA AF MACDONALD, RA TI MODELING MACROMOLECULAR DIFFUSION THROUGH A POROUS-MEDIUM SO JOURNAL OF MEMBRANE SCIENCE LA English DT Article DE CERAMIC MEMBRANES; DIFFUSION; MICROPOROUS AND POROUS MEMBRANES; THEORY ID TRANSPORT; FLOW; DISPERSION AB The diffusion of large spherical molecules through a porous medium is studied by means of a two-dimensional computer model developed previously [Int. J. Thermophys., 9 (1988) 1061]. For two well-characterized, bimodal, pore size distributions, a random walk procedure is used to determine the diffusivity under several conditions of wall-molecule interaction, represented by a residence time, and pore connectivity, or tortuosity. To simulate a driving force on the molecules, a constant bias in one direction is imposed on the random walk. The unbiased case is also studied. Pore sizes are chosen either at random from each distribution or from one distribution at a time to form a layered structure. The selectivity of the diffusion with respect to molecular size is monitored. The wall-molecule interaction and the molecule size both have an important effect on diffusion, as expected. The arrangement of the pore size distributions, whether in layers or at random, has only a small effect. RP MACDONALD, RA (reprint author), NATL INST STAND & TECHNOL,DIV THERMOPHYS,GAITHERSBURG,MD 20899, USA. NR 14 TC 5 Z9 5 U1 0 U2 0 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0376-7388 J9 J MEMBRANE SCI JI J. Membr. Sci. PD APR 10 PY 1992 VL 68 IS 1-2 BP 93 EP 106 DI 10.1016/0376-7388(92)80152-A PG 14 WC Engineering, Chemical; Polymer Science SC Engineering; Polymer Science GA HR263 UT WOS:A1992HR26300008 ER PT J AU ROPELEWSKI, CF AF ROPELEWSKI, CF TI CLIMATE - PREDICTING EL-NINO EVENTS SO NATURE LA English DT Editorial Material ID SOUTHERN OSCILLATION RP ROPELEWSKI, CF (reprint author), NOAA,CTR CLIMAT ANAL,WORLD WEATHER BLDG,WASHINGTON,DC 20233, USA. NR 9 TC 13 Z9 13 U1 0 U2 4 PU MACMILLAN MAGAZINES LTD PI LONDON PA PORTERS SOUTH, 4 CRINAN ST, LONDON, ENGLAND N1 9XW SN 0028-0836 J9 NATURE JI Nature PD APR 9 PY 1992 VL 356 IS 6369 BP 476 EP 477 DI 10.1038/356476a0 PG 2 WC Multidisciplinary Sciences SC Science & Technology - Other Topics GA HN231 UT WOS:A1992HN23100029 ER PT J AU SIMIU, E COOK, GR AF SIMIU, E COOK, GR TI EMPIRICAL FLUID-ELASTIC MODELS AND CHAOTIC GALLOPING - A CASE-STUDY SO JOURNAL OF SOUND AND VIBRATION LA English DT Article ID AUTONOMOUS SYSTEM RP SIMIU, E (reprint author), NATL INST STAND & TECHNOL,BLDG & FIRE RES LAB,GAITHERSBURG,MD 20899, USA. NR 36 TC 6 Z9 6 U1 1 U2 1 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 1992 VL 154 IS 1 BP 45 EP 66 DI 10.1016/0022-460X(92)90403-K PG 22 WC Acoustics; Engineering, Mechanical; Mechanics SC Acoustics; Engineering; Mechanics GA HP393 UT WOS:A1992HP39300003 ER PT J AU AKMAN, SA DOROSHOW, JH BURKE, TG DIZDAROGLU, M AF AKMAN, SA DOROSHOW, JH BURKE, TG DIZDAROGLU, M TI DNA-BASE MODIFICATIONS INDUCED IN ISOLATED HUMAN CHROMATIN BY NADH DEHYDROGENASE-CATALYZED REDUCTION OF DOXORUBICIN SO BIOCHEMISTRY LA English DT Article ID ANTI-CANCER AGENTS; FREE-RADICALS; HYDROGEN-PEROXIDE; IONIZING-RADIATION; LIPID-PEROXIDATION; ADRIAMYCIN; DAMAGE; SITE; GENERATION; MECHANISM AB The antineoplastic benzanthroquinone drug doxorubicin can undergo flavoenzyme-catalyzed one-electron reduction which, in an aerobic environment, leads to the generation of oxygen-derived species. We therefore sought to determine whether doxorubicin in the presence of NADH dehydrogenase and the transition metal ions Fe(III) or Cu(II) induces DNA base modifications in isolated human chromatin. NADH dehydrogenase-catalyzed reduction of doxorubicin (25-100-mu-M) caused hydroxyl radical production detected as methane generated from dimethyl sulfoxide; addition of isolated human chromatin to the system produced a concentration-dependent quenching of detectable hydroxyl radical formation. Doxorubicin (5-50-mu-M)-stimulated enzyme-catalyzed oxidation of NADH was also diminished, but still detectable, in the presence of chromatin. Doxorubicin-induced DNA base modifications in chromatin were measured by gas chromatography/mass spectrometry with selected-ion monitoring. Production of modified bases required the addition of transition metal ion and was enhanced by the addition of active flavoenzyme. The non-redox cycling analogue 5-iminodaunorubicin induced significantly less base modification than did doxorubicin. In the presence of Fe(III), NADH dehydrogenase-catalyzed reduction of doxorubicin caused enhancement in the content of all modified bases over control levels. Substitution of Cu(II) for Fe(III) altered both the degree and the pattern of doxorubicin/NADH dehydrogenase-induced base modifications. The scavengers of hydroxyl radical mannitol and dimethyl sulfoxide or catalase did not significantly affect doxorubicin/NADH/NADH dehydrogenase/transition metal ion-induced base modifications. Superoxide dismutase further enhanced production of all base modifications. The data demonstrate that flavoenzyme-catalyzed redox cycling of doxorubicin generates typical hydroxyl radical-induced base modifications in the DNA of isolated human chromatin, suggesting a possible mechanism for the mutagenicity of doxorubicin in vivo. C1 NATL INST STAND & TECHNOL,CHEM SCI & TECHNOL LAB,GAITHERSBURG,MD 20899. RP AKMAN, SA (reprint author), CITY HOPE NATL MED CTR,DEPT MED ONCOL & THERAPEUT RES,1500 E DUARTE RD,DUARTE,CA 91010, USA. NR 46 TC 37 Z9 37 U1 0 U2 2 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 SN 0006-2960 J9 BIOCHEMISTRY-US JI Biochemistry PD APR 7 PY 1992 VL 31 IS 13 BP 3500 EP 3506 DI 10.1021/bi00128a026 PG 7 WC Biochemistry & Molecular Biology SC Biochemistry & Molecular Biology GA HM442 UT WOS:A1992HM44200026 PM 1313297 ER PT J AU SUMARLIN, IW SKANTHAKUMAR, S LYNN, JW PENG, JL LI, ZY JIANG, W GREENE, RL AF SUMARLIN, IW SKANTHAKUMAR, S LYNN, JW PENG, JL LI, ZY JIANG, W GREENE, RL TI MAGNETIC-ORDERING OF SM IN SM2CUO4 SO PHYSICAL REVIEW LETTERS LA English DT Article ID PHASE-TRANSITIONS; SUPERCONDUCTING PROPERTIES; SPIN CORRELATIONS; ND2CUO4; PR2CUO4; CRYSTALS; ND AB Long-range antiferromagnetic order of the Sm ions in Sm2CuO4 is observed via neutron diffraction at T(N) = 5.95 K. The magnetic structure consists of ferromagnetic sheets within the a-b planes, with the spins in alternate sheets aligned antiparallel. This spin structure and spin direction are completely different from those observed in any other copper-oxide superconductor system. The temperature dependence of the upper critical field H(c2) for the superconductor Sm1.85Ce0.15CuO4 (T(c) = 23.5 K) shows a sudden increase in H(c2) at T/T(c) is similar to 0.7, but this anomaly cannot be attributed to the Sm magnetic ordering. No anomaly in H(c2) is observed at the T(N) for Sm. C1 NATL INST STAND & TECHNOL,GAITHERSBURG,MD 20899. RP SUMARLIN, IW (reprint author), UNIV MARYLAND,DEPT PHYS,CTR SUPERCONDUCT RES,COLLEGE PK,MD 20742, USA. NR 22 TC 71 Z9 71 U1 0 U2 3 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 0031-9007 J9 PHYS REV LETT JI Phys. Rev. Lett. PD APR 6 PY 1992 VL 68 IS 14 BP 2228 EP 2231 DI 10.1103/PhysRevLett.68.2228 PG 4 WC Physics, Multidisciplinary SC Physics GA HM440 UT WOS:A1992HM44000031 ER PT J AU RUMBLE, J AF RUMBLE, J TI ADVANCES IN EVALUATION OF NUMERIC DATA 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 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 5 PY 1992 VL 203 BP 4 EP CINF PN 1 PG 0 WC Chemistry, Multidisciplinary SC Chemistry GA HK161 UT WOS:A1992HK16101413 ER PT J AU POWELL, LJ AF POWELL, LJ TI NIST SERVICES FOR MEASUREMENT QUALITY ASSURANCE - AN OVERVIEW AND THE OUTLOOK FOR BIOTECHNOLOGY SO ABSTRACTS OF PAPERS OF THE AMERICAN CHEMICAL SOCIETY LA English DT Meeting Abstract C1 NATL INST STAND & TECHNOL,DIV BIOTECHNOL,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 5 PY 1992 VL 203 BP 6 EP SCHB PN 3 PG 0 WC Chemistry, Multidisciplinary SC Chemistry GA HK163 UT WOS:A1992HK16300910 ER PT J AU LEONE, SR AF LEONE, SR TI THE COMPETITION BETWEEN REACTION AND ENERGY-TRANSFER IN FAST ATOM COLLISIONS SO ABSTRACTS OF PAPERS OF THE AMERICAN CHEMICAL SOCIETY LA English DT Meeting Abstract C1 NATL INST STAND & TECHNOL,DEPT CHEM & BIOCHEM,BOULDER,CO 80309. JILA,BOULDER,CO 80309. UNIV COLORADO,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 5 PY 1992 VL 203 BP 16 EP PHYS PN 2 PG 0 WC Chemistry, Multidisciplinary SC Chemistry GA HK162 UT WOS:A1992HK16202112 ER PT J AU NICOL, JM UDOVIC, TJ ELSENHANS, O BUHRER, W FELSCHE, J SEIGER, P AF NICOL, JM UDOVIC, TJ ELSENHANS, O BUHRER, W FELSCHE, J SEIGER, P TI CHARACTERIZATION OF OH-, H2O AND H3O2- SPECIES IN HYDROXY-SODALITES BY INELASTIC NEUTRON-SCATTERING SPECTROSCOPY SO ABSTRACTS OF PAPERS OF THE AMERICAN CHEMICAL SOCIETY LA English DT Meeting Abstract C1 NATL INST STANDARDS & TECHNOL,GAITHERSBURG,MD 20899. PSI,CH-5232 VILLIGEN,SWITZERLAND. UNIV CONSTANCE,W-7750 CONSTANCE,GERMANY. 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 5 PY 1992 VL 203 BP 41 EP INOR PN 2 PG 0 WC Chemistry, Multidisciplinary SC Chemistry GA HK162 UT WOS:A1992HK16200451 ER PT J AU WING, T AF WING, T TI KINETIC STABILITY OF UNSATURATED ORGANICS AT HIGH-TEMPERATURES SO ABSTRACTS OF PAPERS OF THE AMERICAN CHEMICAL SOCIETY LA English DT Meeting Abstract C1 NATL INST STAND & TECHNOL,DIV CHEM KINET & THERMODYNAM,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 5 PY 1992 VL 203 BP 42 EP FUEL PN 1 PG 0 WC Chemistry, Multidisciplinary SC Chemistry GA HK161 UT WOS:A1992HK16102385 ER PT J AU STEIN, SE AF STEIN, SE TI FROM ONE EXTREME TO THE OTHER - USING FUNDAMENTAL CHEMISTRY TO UNDERSTAND COAL BEHAVIOR OVER WIDE RANGES OF CONDITIONS SO ABSTRACTS OF PAPERS OF THE AMERICAN CHEMICAL SOCIETY LA English DT Meeting Abstract C1 NATL INST STAND & TECHNOL,DIV CHEM KINET & THERMODYNAM,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 5 PY 1992 VL 203 BP 45 EP FUEL PN 1 PG 0 WC Chemistry, Multidisciplinary SC Chemistry GA HK161 UT WOS:A1992HK16102388 ER PT J AU WU, YC BEREZANSKY, PA FENG, D KOCH, WF AF WU, YC BEREZANSKY, PA FENG, D KOCH, WF TI MOPSO, A RECOMMENDED ALTERNATIVE TO PHOSPHATE-BASED PH-STANDARDS SO ABSTRACTS OF PAPERS OF THE AMERICAN CHEMICAL SOCIETY LA English DT Meeting Abstract C1 NATL INST STAND & TECHNOL,DIV INORGAN ANALYT RES,ELECTROANALYT RES GRP,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 5 PY 1992 VL 203 BP 58 EP ANYL PN 1 PG 0 WC Chemistry, Multidisciplinary SC Chemistry GA HK161 UT WOS:A1992HK16100405 ER PT J AU RUFAEL, T GLAND, JL FISCHER, DA AF RUFAEL, T GLAND, JL FISCHER, DA TI HYDROGEN INDUCED C-S BOND ACTIVATION ON METAL SINGLE-CRYSTAL SURFACES SO ABSTRACTS OF PAPERS OF THE AMERICAN CHEMICAL SOCIETY LA English DT Meeting Abstract C1 NATL INST STAND & TECHNOL,GAITHERSBURG,MD 20899. UNIV MICHIGAN,DEPT CHEM,ANN ARBOR,MI 48109. 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 5 PY 1992 VL 203 BP 64 EP COLL PN 1 PG 0 WC Chemistry, Multidisciplinary SC Chemistry GA HK161 UT WOS:A1992HK16101579 ER PT J AU BROWN, KK DEAKYNE, CA MEOTNER, M AF BROWN, KK DEAKYNE, CA MEOTNER, M TI THE PROTON POSITION IN [H2O]N[(CH3)3N]MH+ CLUSTER IONS SO ABSTRACTS OF PAPERS OF THE AMERICAN CHEMICAL SOCIETY LA English DT Meeting Abstract C1 NATL INST STAND & TECHNOL,GAITHERSBURG,MD 20899. EASTERN ILLINOIS UNIV,DEPT CHEM,CHARLESTON,IL 61920. 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 5 PY 1992 VL 203 BP 79 EP CHED PN 1 PG 0 WC Chemistry, Multidisciplinary SC Chemistry GA HK161 UT WOS:A1992HK16101082 ER PT J AU CHANG, SS AF CHANG, SS TI EFFECT OF CURING HISTORY ON ULTIMATE GLASS-TRANSITION TEMPERATURE OF CROSS-LINKING POLYMERS SO ABSTRACTS OF PAPERS OF THE AMERICAN CHEMICAL SOCIETY LA English DT Meeting Abstract C1 NATL INST STAND & TECHNOL,DIV POLYMERS,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 5 PY 1992 VL 203 BP 88 EP POLY PN 3 PG 0 WC Chemistry, Multidisciplinary SC Chemistry GA HK163 UT WOS:A1992HK16300088 ER PT J AU HOWARD, CJ AF HOWARD, CJ TI LABORATORY STUDIES OF SOME ATMOSPHERIC RADICAL-RADICAL 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 5 PY 1992 VL 203 BP 101 EP PHYS PN 2 PG 0 WC Chemistry, Multidisciplinary SC Chemistry GA HK162 UT WOS:A1992HK16202197 ER PT J AU BUNTIN, SA KING, DS CAVANAGH, RR RICHTER, LJ AF BUNTIN, SA KING, DS CAVANAGH, RR RICHTER, LJ TI STATE-RESOLVED STUDIES OF SUBSTRATE-MEDIATED DESORPTION SO ABSTRACTS OF PAPERS OF THE AMERICAN CHEMICAL SOCIETY LA English DT Meeting Abstract C1 NATL INST STANDARDS & TECHNOL,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 5 PY 1992 VL 203 BP 104 EP PHYS PN 2 PG 0 WC Chemistry, Multidisciplinary SC Chemistry GA HK162 UT WOS:A1992HK16202200 ER PT J AU KING, DS HETZLER, JR CASASSA, MP AF KING, DS HETZLER, JR CASASSA, MP TI NONADIABATIC EFFECTS IN THE OVERTONE INITIATED DISSOCIATION OF NO-DIMER SO ABSTRACTS OF PAPERS OF THE AMERICAN CHEMICAL SOCIETY LA English DT Meeting Abstract C1 NATL INST STANDARDS & TECHNOL,PHYS LAB,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 5 PY 1992 VL 203 BP 106 EP PHYS PN 2 PG 0 WC Chemistry, Multidisciplinary SC Chemistry GA HK162 UT WOS:A1992HK16202202 ER PT J AU MCKENNA, GB AF MCKENNA, GB TI AGING OF POLYMERIC RESINS - IMPLICATIONS FOR COMPOSITE PERFORMANCE SO ABSTRACTS OF PAPERS OF THE AMERICAN CHEMICAL SOCIETY LA English DT Meeting Abstract C1 NATL INST STAND & TECHNOL,DIV POLYMERS,GAITHERSBURG,MD 20899. RI McKenna, Gregory/O-1134-2013 OI McKenna, Gregory/0000-0002-5676-9930 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 5 PY 1992 VL 203 BP 138 EP POLY PN 3 PG 0 WC Chemistry, Multidisciplinary SC Chemistry GA HK163 UT WOS:A1992HK16300138 ER PT J AU KRAMER, GW AF KRAMER, GW TI STANDARD MODULES AS BUILDING-BLOCKS FOR LABORATORY AUTOMATION 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 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 5 PY 1992 VL 203 BP 156 EP IEC PN 2 PG 0 WC Chemistry, Multidisciplinary SC Chemistry GA HK162 UT WOS:A1992HK16200183 ER PT J AU ROGERS, SA LEONE, SR AF ROGERS, SA LEONE, SR TI CHARGE-TRANSFER REACTIONS OF CO++ WITH THE RARE-GASES SO ABSTRACTS OF PAPERS OF THE AMERICAN CHEMICAL SOCIETY LA English DT Meeting Abstract C1 NATL INST STANDARDS & TECHNOL,JOINT INST LAB ASTROPHYS,DENVER,CO. UNIV COLORADO,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 5 PY 1992 VL 203 BP 175 EP PHYS PN 2 PG 0 WC Chemistry, Multidisciplinary SC Chemistry GA HK162 UT WOS:A1992HK16202271 ER PT J AU VORSA, V PAPANIKOLAS, JM GORD, JR NADAL, ME LINEBERGER, WC AF VORSA, V PAPANIKOLAS, JM GORD, JR NADAL, ME LINEBERGER, WC TI TIME-RESOLVED CAGING DYNAMICS OF I2-EMBEDDED IN CO2 CLUSTERS SO ABSTRACTS OF PAPERS OF THE AMERICAN CHEMICAL SOCIETY LA English DT Meeting Abstract C1 NATL INST STANDARDS & TECHNOL,BOULDER,CO 80309. UNIV COLORADO,JOINT INST LAB ASTROPHYS,BOULDER,CO 80309. UNIV COLORADO,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 5 PY 1992 VL 203 BP 200 EP PHYS PN 2 PG 0 WC Chemistry, Multidisciplinary SC Chemistry GA HK162 UT WOS:A1992HK16202296 ER PT J AU POLAK, ML ROBINSON, MS BIERBAUM, VM DEPUY, CH LINEBERGER, WC AF POLAK, ML ROBINSON, MS BIERBAUM, VM DEPUY, CH LINEBERGER, WC TI HEATS OF FORMATION OF C3HN RADICALS SO ABSTRACTS OF PAPERS OF THE AMERICAN CHEMICAL SOCIETY LA English DT Meeting Abstract C1 UNIV COLORADO,JOINT INST LAB ASTROPHYS,BOULDER,CO 80302. NATL INST STANDARDS & TECHNOL,BOULDER,CO 80302. UNIV COLORADO,DEPT CHEM,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 5 PY 1992 VL 203 BP 201 EP PHYS PN 2 PG 0 WC Chemistry, Multidisciplinary SC Chemistry GA HK162 UT WOS:A1992HK16202297 ER PT J AU NGUYEN, T BYRD, WE BENTZ, DP AF NGUYEN, T BYRD, WE BENTZ, DP TI QUANTIFYING WATER AT THE COATING SUBSTRATE INTERFACE 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 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 5 PY 1992 VL 203 BP 208 EP PMSE PN 3 PG 0 WC Chemistry, Multidisciplinary SC Chemistry GA HK163 UT WOS:A1992HK16300830 ER PT J AU GLAND, JL RUFAEL, T HUANG, XA FISCHER, DA AF GLAND, JL RUFAEL, T HUANG, XA FISCHER, DA TI ULTRA-SOFT X-RAY ABSORPTION DETECTED BY FLUORESCENCE YIELD - AN INSITU METHOD FOR CHARACTERIZING SURFACE-REACTIONS SO ABSTRACTS OF PAPERS OF THE AMERICAN CHEMICAL SOCIETY LA English DT Meeting Abstract C1 UNIV MICHIGAN,DEPT CHEM,ANN ARBOR,MI 48109. NATL INST STAND & 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 5 PY 1992 VL 203 BP 230 EP COLL PN 1 PG 0 WC Chemistry, Multidisciplinary SC Chemistry GA HK161 UT WOS:A1992HK16101745 ER PT J AU WILLIAMS, CJ JULIENNE, PS AF WILLIAMS, CJ JULIENNE, PS TI NONADIABATIC COLLISIONS OF GROUND-STATE H(S-2) ATOMS AT SUB-MILLIKELVIN TEMPERATURES SO ABSTRACTS OF PAPERS OF THE AMERICAN CHEMICAL SOCIETY LA English DT Meeting Abstract C1 NATL INST STAND & TECHNOL,GAITHERSBURG,MD 20899. UNIV CHICAGO,JAMES FRANCK INST,CHICAGO,IL 60637. RI Julienne, Paul/E-9378-2012 OI Julienne, Paul/0000-0002-5494-1442 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 5 PY 1992 VL 203 BP 286 EP PHYS PN 2 PG 0 WC Chemistry, Multidisciplinary SC Chemistry GA HK162 UT WOS:A1992HK16202382 ER PT J AU SOLOMON, S AF SOLOMON, S TI GLOBAL OZONE DEPLETION - A REVIEW SO ABSTRACTS OF PAPERS OF THE AMERICAN CHEMICAL SOCIETY LA English DT Meeting Abstract C1 NOAA,AERON LAB,BOULDER,CO 80309. 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 5 PY 1992 VL 203 BP 308 EP PHYS PN 2 PG 0 WC Chemistry, Multidisciplinary SC Chemistry GA HK162 UT WOS:A1992HK16202404 ER PT J AU GADZUK, JW AF GADZUK, JW TI HOT-ELECTRONS - THE KEY TO SURFACE PHOTOCHEMISTRY 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 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 5 PY 1992 VL 203 BP 310 EP PHYS PN 2 PG 0 WC Chemistry, Multidisciplinary SC Chemistry GA HK162 UT WOS:A1992HK16202406 ER PT J AU SMITH, DT HORN, RG AF SMITH, DT HORN, RG TI STUDYING TRIBOCHARGING AND ADHESION WITH THE SURFACE FORCE APPARATUS SO ABSTRACTS OF PAPERS OF THE AMERICAN CHEMICAL SOCIETY LA English DT Meeting Abstract C1 NIST,DIV CERAM,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 5 PY 1992 VL 203 BP 327 EP COLL PN 1 PG 0 WC Chemistry, Multidisciplinary SC Chemistry GA HK161 UT WOS:A1992HK16101842 ER PT J AU HAIR, DW HOBBIE, EK DOUGLAS, J HAN, CC AF HAIR, DW HOBBIE, EK DOUGLAS, J HAN, CC TI STATIC AND DYNAMIC CRITICAL-BEHAVIOR OF AN ASYMMETRIC BINARY POLYMER BLEND SO ABSTRACTS OF PAPERS OF THE AMERICAN CHEMICAL SOCIETY LA English DT Meeting Abstract C1 NATL INST STAND & TECHNOL,DIV POLYMERS,GAITHERSBURG,MD 20899. RI Hobbie, Erik/C-8269-2013 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 5 PY 1992 VL 203 BP 332 EP POLY PN 3 PG 0 WC Chemistry, Multidisciplinary SC Chemistry GA HK163 UT WOS:A1992HK16300324 ER PT J AU NESBITT, DJ AF NESBITT, DJ TI INTERMOLECULAR FORCES THROUGH HIGH-RESOLUTION IR SPECTROSCOPY OF CLUSTERS SO ABSTRACTS OF PAPERS OF THE AMERICAN CHEMICAL SOCIETY LA English DT Meeting Abstract C1 NATL INST STAND & TECHNOL,JOINT INST LAB ASTROPHYS,BOULDER,CO 80309. UNIV CHICAGO,CHICAGO,IL 60637. 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 5 PY 1992 VL 203 BP 337 EP PHYS PN 2 PG 0 WC Chemistry, Multidisciplinary SC Chemistry GA HK162 UT WOS:A1992HK16202433 ER PT J AU KRANBUEHL, DE VERDIER, PH AF KRANBUEHL, DE VERDIER, PH TI EFFECTS OF BEAD SIZE ON THE DIMENSIONS OF MODEL POLYMER-CHAINS SO ABSTRACTS OF PAPERS OF THE AMERICAN CHEMICAL SOCIETY LA English DT Meeting Abstract C1 COLL WILLIAM & MARY,DEPT CHEM,WILLIAMSBURG,VA 23187. NATL INST STAND & TECHNOL,DIV POLYMERS,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 5 PY 1992 VL 203 BP 344 EP POLY PN 3 PG 0 WC Chemistry, Multidisciplinary SC Chemistry GA HK163 UT WOS:A1992HK16300336 ER PT J AU VERDIER, PH KRANBUEHL, DE AF VERDIER, PH KRANBUEHL, DE TI EXCLUDED VOLUME AND ENTANGLEMENT EFFECTS IN POLYMER-CHAIN DYNAMICS SO ABSTRACTS OF PAPERS OF THE AMERICAN CHEMICAL SOCIETY LA English DT Meeting Abstract C1 NATL INST STAND & TECHNOL,DIV POLYMERS,GAITHERSBURG,MD 20899. COLL WILLIAM & MARY,DEPT CHEM,WILLIAMSBURG,VA 23187. 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 5 PY 1992 VL 203 BP 345 EP POLY PN 3 PG 0 WC Chemistry, Multidisciplinary SC Chemistry GA HK163 UT WOS:A1992HK16300337 ER PT J AU BUNTIN, SA KING, DS CAVANAGH, RR RICHTER, LJ AF BUNTIN, SA KING, DS CAVANAGH, RR RICHTER, LJ TI STATE-RESOLVED STUDIES OF LASER-INDUCED DESORPTION FROM SILICON SUBSTRATES SO ABSTRACTS OF PAPERS OF THE AMERICAN CHEMICAL SOCIETY LA English DT Meeting Abstract C1 NATL INST STAND & TECHNOL,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 5 PY 1992 VL 203 BP 354 EP PHYS PN 2 PG 0 WC Chemistry, Multidisciplinary SC Chemistry GA HK162 UT WOS:A1992HK16202450 ER PT J AU ANTONUCCI, JM STANSBURY, JW REED, BB AF ANTONUCCI, JM STANSBURY, JW REED, BB TI RADICAL RING-OPENING EFFICIENCY OF 2 ARYL SUBSTITUTED CYCLIC KETENE ACETALS - COMPOSITE APPLICATIONS 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 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 5 PY 1992 VL 203 BP 390 EP POLY PN 3 PG 0 WC Chemistry, Multidisciplinary SC Chemistry GA HK163 UT WOS:A1992HK16300382 ER PT J AU BRIBER, RM BAUER, BJ AF BRIBER, RM BAUER, BJ TI THERMODYNAMICS AND SMALL-ANGLE NEUTRON-SCATTERING OF CROSS-LINKED POLYMER MIXTURES SO ABSTRACTS OF PAPERS OF THE AMERICAN CHEMICAL SOCIETY LA English DT Meeting Abstract C1 NATL INST STAND & TECHNOL,DIV POLYMERS,GAITHERSBURG,MD 20899. RI Briber, Robert/A-3588-2012 OI Briber, Robert/0000-0002-8358-5942 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 5 PY 1992 VL 203 BP 429 EP POLY PN 3 PG 0 WC Chemistry, Multidisciplinary SC Chemistry GA HK163 UT WOS:A1992HK16300420 ER PT J AU BRIBER, RM GHOLZ, E WU, SM AF BRIBER, RM GHOLZ, E WU, SM TI IMAGE-ANALYSIS OF THE LATE STAGES OF PHASE-SEPARATION IN POLYMER BLENDS SO ABSTRACTS OF PAPERS OF THE AMERICAN CHEMICAL SOCIETY LA English DT Meeting Abstract C1 NATL INST STAND & TECHNOL,GAITHERSBURG,MD 20899. RI Briber, Robert/A-3588-2012 OI Briber, Robert/0000-0002-8358-5942 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 5 PY 1992 VL 203 BP 582 EP POLY PN 3 PG 0 WC Chemistry, Multidisciplinary SC Chemistry GA HK163 UT WOS:A1992HK16300568 ER PT J AU SIEVERS, RE HYBERTSON, BM HANSEN, BN BARKLEY, RM AF SIEVERS, RE HYBERTSON, BM HANSEN, BN BARKLEY, RM TI CHEMICAL-DEPOSITION FROM CHELATES DISSOLVED IN SUPERCRITICAL FLUIDS 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,NOAA,COOPERAT INST RES ENVIRONM SCI,BOULDER,CO 80309. NR 0 TC 1 Z9 1 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 5 PY 1992 VL 203 BP 667 EP INOR PN 2 PG 0 WC Chemistry, Multidisciplinary SC Chemistry GA HK162 UT WOS:A1992HK16201075 ER PT J AU NENOFF, TM HARRISON, WTA GIER, TE NICOL, JM HRILJAC, JA STUCKY, GD AF NENOFF, TM HARRISON, WTA GIER, TE NICOL, JM HRILJAC, JA STUCKY, GD TI STRUCTURES AND PROPERTIES OF NEW NON-ALUMINOSILICATE FRAMEWORKS SO ABSTRACTS OF PAPERS OF THE AMERICAN CHEMICAL SOCIETY LA English DT Meeting Abstract C1 UNIV CALIF SANTA CRUZ,DEPT CHEM,SANTA CRUZ,CA 95064. NATL INST STAND & TECHNOL,DIV REACTOR RADIAT,GAITHERSBURG,MD 20899. BROOKHAVEN NATL LAB,DEPT PHYS,UPTON,NY 11973. 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 5 PY 1992 VL 203 BP 779 EP INOR PN 2 PG 0 WC Chemistry, Multidisciplinary SC Chemistry GA HK162 UT WOS:A1992HK16201187 ER PT J AU LYNN, JW AF LYNN, JW TI 2-DIMENSIONAL BEHAVIOR OF THE RARE-EARTH ORDERING IN OXIDE SUPERCONDUCTORS SO JOURNAL OF ALLOYS AND COMPOUNDS LA English DT Article ID DIMENSIONAL MAGNETISM; NEUTRON-SCATTERING; ERBA2CU3O7; GDBA2CU3O7-DELTA; HEAT; ND AB Neutron scattering has been used to reveal the nature of the magnetic ordering of the rare earth ions in 1-2-3, 2-4-8, 2-4-7 and 2-1-4 oxide superconductors. The interactions are found to be antiferromagnetic in nature and quite weak, leading to ordering temperatures which are a few degrees Kelvin or less. In the first three systems the separation of the rare earth ions is much larger along the c axis than along the a-b directions, which renders these materials prototypical two-dimensional (2D) magnets. In the ErBa2Cu3O7 and DyBa2Cu3O7 systems, for example, a rod of scattering characteristic of 2D behavior is readily observed, while the order parameter obeys the exact solution of the S = 1/2, 2D Ising model. An extreme case of 2D behavior is found for the DyBa2Cu4O8 material, where a geometric cancellation of the already weak interactions occurs along the c axis, effectively decoupling the rare earth a-b layers. The system thus exhibits no crossover to the 3D behavior usually found well below the ordering temperature, making it the best example of a 2D magnet known to date. C1 UNIV MARYLAND,CTR SUPERCONDUCT RES,DEPT PHYS,COLLEGE PK,MD 20742. RP LYNN, JW (reprint author), NATL INST STAND & TECHNOL,DIV REACTOR RADIAT,GAITHERSBURG,MD 20899, USA. NR 32 TC 40 Z9 40 U1 1 U2 8 PU ELSEVIER SCIENCE SA LAUSANNE PI LAUSANNE 1 PA PO BOX 564, 1001 LAUSANNE 1, SWITZERLAND SN 0925-8388 J9 J ALLOY COMPD JI J. Alloy. Compd. PD APR 3 PY 1992 VL 181 BP 419 EP 429 DI 10.1016/0925-8388(92)90337-9 PG 11 WC Chemistry, Physical; Materials Science, Multidisciplinary; Metallurgy & Metallurgical Engineering SC Chemistry; Materials Science; Metallurgy & Metallurgical Engineering GA HP963 UT WOS:A1992HP96300046 ER PT J AU SONI, KK WILLIAMS, DB CHABALA, JM LEVISETTI, R NEWBURY, DE AF SONI, KK WILLIAMS, DB CHABALA, JM LEVISETTI, R NEWBURY, DE TI ELECTRON AND ION MICROSCOPY STUDIES OF FE-RICH 2ND-PHASE PARTICLES IN AL-LI ALLOYS SO ACTA METALLURGICA ET MATERIALIA LA English DT Article ID ALUMINUM-LITHIUM ALLOYS; PRECIPITATE FREE ZONES; MICROANALYSIS; SPECTROMETRY; MICROPROBE; ENERGY AB Second-phase particles associated with trace amounts of impurities in binary Al-Li alloys were characterized by analytical electron microscopy (AEM) and secondary ion mass spectrometry (SIMS). These particles were analyzed by X-ray microanalysis to be Fe-rich and identified by electron diffraction to be Al3Fe. The Al3Fe precipitates were seen to be faulted along a preferred crystallographic direction. Also, they were surrounded by a delta' precipitate free zone (PFZ) with coarser delta' at the edge of the PFZ than in the rest of the matrix. SIMS analysis revealed detectable, but negligible, Li in these Al3Fe particles; based on this observation, the above mentioned PFZs are suggested to be a result of vacancy loss to the incoherent interface. C1 NATL INST STAND & TECHNOL, CTR ANALYT CHEM, GAITHERSBURG, MD 20899 USA. UNIV CHICAGO, ENRICO FERMI INST, CHICAGO, IL 60637 USA. UNIV CHICAGO, ENRICO FERMI INST, DEPT PHYS, CHICAGO, IL 60637 USA. RP SONI, KK (reprint author), LEHIGH UNIV, DEPT MAT SCI & ENGN, BETHLEHEM, PA 18015 USA. NR 29 TC 4 Z9 4 U1 1 U2 3 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLAND SN 0956-7151 J9 ACTA METALL MATER JI Acta Metall. Mater. PD APR PY 1992 VL 40 IS 4 BP 663 EP 671 DI 10.1016/0956-7151(92)90007-2 PG 9 WC Materials Science, Multidisciplinary; Metallurgy & Metallurgical Engineering SC Materials Science; Metallurgy & Metallurgical Engineering GA HJ890 UT WOS:A1992HJ89000007 ER PT J AU CLEARY, TG MULHOLLAND, GW IVES, LK FLETCHER, RA GENTRY, JW AF CLEARY, TG MULHOLLAND, GW IVES, LK FLETCHER, RA GENTRY, JW TI ULTRAFINE COMBUSTION AEROSOL GENERATOR SO AEROSOL SCIENCE AND TECHNOLOGY LA English DT Article ID STRUCTURAL-ANALYSIS; MASS-SPECTROMETRY; LASER C1 UNIV MARYLAND,DEPT CHEM & NUCL ENGN,COLLEGE PK,MD 20742. RP CLEARY, TG (reprint author), NATL INST STAND & TECHNOL,GAITHERSBURG,MD 20899, USA. NR 9 TC 7 Z9 7 U1 0 U2 0 PU ELSEVIER SCIENCE INC PI NEW YORK PA 655 AVENUE OF THE AMERICAS, NEW YORK, NY 10010 SN 0278-6826 J9 AEROSOL SCI TECH JI Aerosol Sci. Technol. PD APR PY 1992 VL 16 IS 3 BP 166 EP 170 DI 10.1080/02786829208959546 PG 5 WC Engineering, Chemical; Environmental Sciences; Meteorology & Atmospheric Sciences SC Engineering; Environmental Sciences & Ecology; Meteorology & Atmospheric Sciences GA HT671 UT WOS:A1992HT67100003 ER PT J AU COPLEY, SD CROOKS, GP AF COPLEY, SD CROOKS, GP TI ENZYMATIC DEHALOGENATION OF 4-CHLOROBENZOYL COENZYME-A IN ACINETOBACTER SP STRAIN 4-CB1 SO APPLIED AND ENVIRONMENTAL MICROBIOLOGY LA English DT Note ID ARTHROBACTER SP; HYDROXYBENZOYL ESTERS; DEGRADATION; ACID; METABOLISM; BENZOYL AB 4-Chlorobenzoate degradation in cell extracts of Acinetobacter sp. strain 4-CB1 occurs by initial synthesis of 4-chlorobenzoyl coenzyme A (4-chlorobenzoyl CoA) from 4-chlorobenzoate, CoA, and ATP. 4-Chlorobenzoyl CoA is dehalogenated to 4-hydroxybenzoyl CoA. Following the dehalogenation reaction, 4-hydroxybenzoyl CoA is hydrolyzed to 4-hydroxybenzoate and CoA. Possible roles for the CoA moiety in the dehalogenation reaction are discussed. C1 UNIV COLORADO,NOAA,COOPERAT INST RES ENVIRONM SCI,BOULDER,CO 80309. RP COPLEY, SD (reprint author), UNIV COLORADO,DEPT CHEM & BIOCHEM,BOULDER,CO 80309, USA. NR 19 TC 22 Z9 24 U1 0 U2 3 PU AMER SOC MICROBIOLOGY PI WASHINGTON PA 1325 MASSACHUSETTS AVENUE, NW, WASHINGTON, DC 20005-4171 SN 0099-2240 J9 APPL ENVIRON MICROB JI Appl. Environ. Microbiol. PD APR PY 1992 VL 58 IS 4 BP 1385 EP 1387 PG 3 WC Biotechnology & Applied Microbiology; Microbiology SC Biotechnology & Applied Microbiology; Microbiology GA HM121 UT WOS:A1992HM12100050 PM 16348702 ER PT J AU SHIMSHOCK, N SENNEFELDER, G DUEKER, M THURBERG, F YARISH, C AF SHIMSHOCK, N SENNEFELDER, G DUEKER, M THURBERG, F YARISH, C TI PATTERNS OF METAL ACCUMULATION IN LAMINARIA-LONGICRURIS FROM LONG-ISLAND SOUND (CONNECTICUT) SO ARCHIVES OF ENVIRONMENTAL CONTAMINATION AND TOXICOLOGY LA English DT Article ID FUCUS-VESICULOSUS; BROWN SEAWEED; INDICATORS; ESTUARIES; POLLUTION AB Laminaria longicruris de la Pyl. samples were harvested from Long Island Sound (Connecticut) from January 1985 to January 1986. Cadmium and copper content was determined by atomic absorption spectrophotometry from four tissue types; young blade, old blade, young stipe and old stipe. The results were statistically analyzed for differences in both type and age of tissue. Concentrations of cadmium were consistently lower than copper concentrations for all months and all tissue types. Statistically significant differences (p > 0.05) were found between the four tissue types for copper in the months of March, June, July, October and December, and for cadmium in the months of February, March, June, July, October and November. Young blade tissue and young stipe tissue were the tissues which most frequently found to be statistically different from the other tissues. Young stipe tissue had the lowest trace metal concentrations (1.3 mean ppm, dry wt. Cu, 0.22 mean ppm, dry wt. Cd). Young blade tissue had significantly higher metal values in comparison to the other tissues for the months of June and October. Old tissue of L. longicruris is the most suitable for use in biomonitoring of trace metals due to the relatively little variation in metal content that was found throughout the study period. C1 NOAA,NATL MARINE FISHERIES,MILFORD,CT 06460. UNIV CONNECTICUT,DEPT STAT,STAMFORD,CT 06903. NR 40 TC 7 Z9 7 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 APR PY 1992 VL 22 IS 3 BP 305 EP 312 PG 8 WC Environmental Sciences; Toxicology SC Environmental Sciences & Ecology; Toxicology GA HJ284 UT WOS:A1992HJ28400010 PM 1616316 ER PT J AU KUDRITZKI, RP HUMMER, DG PAULDRACH, AWA PULS, J NAJARRO, F IMHOFF, J AF KUDRITZKI, RP HUMMER, DG PAULDRACH, AWA PULS, J NAJARRO, F IMHOFF, J TI RADIATION-DRIVEN WINDS OF HOT LUMINOUS STARS .10. THE DETERMINATION OF STELLAR MASSES, RADII AND DISTANCES FROM TERMINAL VELOCITIES AND MASS-LOSS RATES SO ASTRONOMY & ASTROPHYSICS LA English DT Article DE ATMOSPHERES OF HOT STARS; STELLAR WINDS; STELLAR MASSES; STELLAR RADII; STELLAR DISTANCES ID NON-LTE ANALYSIS; O-STARS; QUANTITATIVE SPECTROSCOPY; MAGELLANIC CLOUDS; MODELS; CONTINUUM; EVOLUTION; SPECTRUM AB A new, purely spectroscopic method to determine masses, radii and distances of massive, luminous hot stars is presented. This method is based on the theory of radiation-driven winds and uses terminal velocity, mass-loss rate and effective temperature as observational quantities determined from the spectrum. It is demonstrated that in situations where the distance is already known from other methods, masses can be determined from v(infinity) and T(eff) with an accuracy of +/- 25%, which is a factor of two better than the classical method using the information obtainable from the quantitative analysis of photospheric absorption lines. These masses, which agree with those obtained from the spectroscopic values of log g, are systematically somewhat smaller than masses found from evolutionary calculations. An independent determination of radii and distances is possible, if good measurements of mass-loss rates can be carried out. For two examples, zeta-Puppis and P Cygni, it is shown that in such cases radii can be determined to an accuracy of +/- 25%. This would transform into an uncertainty in distance modulus of DELTA-m(v) = +/- 0.5 mag for an individual object. The potential of this method is discussed. C1 JOINT INST LAB ASTROPHYS, BOULDER, CO 80309 USA. NATL INST STAND & TECHNOL, BOULDER, CO 80309 USA. MAX PLANCK INST ASTROPHYS, W-8046 GARCHING, GERMANY. RP KUDRITZKI, RP (reprint author), UNIV MUNICH, INST ASTRON & ASTROPHYS, SCHEINERSTR 1, W-8000 MUNICH 80, GERMANY. RI Najarro, Francisco/G-7288-2015 OI Najarro, Francisco/0000-0002-9124-0039 NR 33 TC 59 Z9 59 U1 0 U2 1 PU EDP SCIENCES S A PI LES ULIS CEDEX A PA 17, AVE DU HOGGAR, PA COURTABOEUF, BP 112, F-91944 LES ULIS CEDEX A, FRANCE SN 0004-6361 J9 ASTRON ASTROPHYS JI Astron. Astrophys. PD APR PY 1992 VL 257 IS 2 BP 655 EP 662 PG 8 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA HQ506 UT WOS:A1992HQ50600036 ER PT J AU LUTTERMOSER, DG JOHNSON, HR AF LUTTERMOSER, DG JOHNSON, HR TI IONIZATION AND EXCITATION IN COOL GIANT STARS .1. HYDROGEN AND HELIUM SO ASTROPHYSICAL JOURNAL LA English DT Article DE RADIATIVE TRANSFER; STARS ATMOSPHERES; STARS LATE-TYPE ID OUTER ATMOSPHERIC STRUCTURE; SOLAR CHROMOSPHERE; MODEL ATMOSPHERES; NEUTRAL HELIUM; CARBON STARS; CONSTRAINTS; STRENGTHS; IUE AB We demonstrate the influence that non-LTE radiative transfer has on the electron density, ionization equilibrium, and excitation equilibrium, in model atmospheres representative of both oxygen-rich and carbon-rich red giant stars. The radiative transfer and statistical equilibrium equations are solved self-consistently for H, H-, H-2, He I, C I, C II, Na I, Mg I, Mg II, Ca I, and Ca II in a plane-parallel static medium. Calculations are made for both (a) radiative-equilibrium model photospheres alone and (b) model photospheres with attached chromospheric models as determined semiempirically with IUE spectra of g Her (M6 III) and TX Psc (C6, 2). This paper reports on the excitation and ionization results for hydrogen and helium. The second paper in this series will concern itself with results obtained for the neutral metals and their importance to the electron density and H- opacity. Although hydrogen is strongly overionized with respect to LTE throughout much of the atmosphere of the photospheric models, almost all the hydrogen is still in the ground state or associated in H-2, and the hydrogen contribution to the electron density is small. Thus this overionization has little impact on the atmospheric structure or the emergent spectrum. Similar, even stronger, results are found for helium. Radiative equilibrium models converged with polyatomic molecular opacities have hydrogen ionization and excitation equilibria that are fundamentally different than those models converged with diatomic molecular opacities alone. The Lyman lines control the ionization and excitation in these model atmospheres. Carbon abundance influences the ionization and excitation of hydrogen through the strong C I bound-free opacity under the Lyman lines-carbon stars are overionized and overexcited in hydrogen with respect to oxygen-rich stars of similar temperatures and surface gravities. Attaching a chromospheric temperature rise to the outer layers further increases the ionization in the upper photosphere from "chromospheric backwarming." Partial redistribution effects in Ly-alpha have significant consequences in the ionization and excitation of hydrogen in the temperature minimum region of the g Her chromospheric-photospheric model and the lower chromosphere of the TX Psc model. Although the Lyman lines are very optically thick throughout much of these models, detailed balance does not hold for these lines, and detailed radiative transfer plays a fundamental role in the ionization and excitation of hydrogen throughout the entire atmospheres. Helium is ionized only slightly in these chromospheric models, and its ionization essentially plays no role. C1 NATL INST STAND & TECHNOL, BOULDER, CO 80309 USA. UNIV COLORADO, JOINT INST LAB ASTROPHYS, BOULDER, CO 80309 USA. INDIANA UNIV, DEPT ASTRON, BLOOMINGTON, IN 47405 USA. NR 38 TC 18 Z9 18 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 1 PY 1992 VL 388 IS 2 BP 579 EP 594 DI 10.1086/171175 PN 1 PG 16 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA HM051 UT WOS:A1992HM05100030 ER PT J AU PLEIM, JE CHANG, JS AF PLEIM, JE CHANG, JS TI A NONLOCAL CLOSURE-MODEL FOR VERTICAL MIXING IN THE CONVECTIVE BOUNDARY-LAYER SO ATMOSPHERIC ENVIRONMENT PART A-GENERAL TOPICS LA English DT Article DE CONVECTIVE BOUNDARY LAYER; NONLOCAL CLOSURE MODEL; VERTICAL MIXING; REGIONAL ATMOSPHERIC CHEMISTRY MODEL; ASYMMETRICAL MIXING ID TRANSPORT; AIR; SENSITIVITY; DIFFUSION; SCALAR AB A simple non-local closure model for vertical mixing in Convective Boundary Layers (CBL) has been developed specifically for application in regional or mesoscale atmospheric chemistry models. The model, named the Asymmetrical Convective Model (ACM), is based on the concept that vertical transport within the CBL is inherently asymmetrical. Upward transport by buoyant plumes originating in the surface layer is simulated by mixing from the lowest model layer directly to all other layers in the CBL. Downward transport, however, proceeds only to the next lower layer in order to emulate gradual compensatory subsidence. The ACM is similar to the model developed by Blackadar (1978, 4th Symp. on Atmospheric Turbulence. Diffusion and Air Quality, pp. 443-447, Reno, Am. Meteorol. Soc.) but differs in its treatment of downward transport. The realism of the ACM is tested through comparisons to large-eddy simulations of several idealized test cases. These tests show that while the ACM shares the Blackadar model's ability to simulate rapid transport upward from the surface layer to all levels in the CBL, it is clearly superior in its treatment of material emitted from elevated sources either within or above the CBL. The ACM is also tested in the context of the Regional Acid Deposition Model (RADM) both to determine sensitivity to different CBL mixing schemes and to compare to vertically resolved aircraft measurements. These tests demonstrate quicker upward transport of ground-level emissions by the ACM as compared to the eddy diffusion scheme currently used in RADM. The ACM also affects ozone photochemistry in the boundary layer resulting in lower ozone concentrations in areas of high NOx emissions. C1 NOAA,DIV ATMOSPHER SCI MODELING,AIR RESOURCES LAB,RES TRIANGLE PK,NC 27711. SUNY ALBANY,ATMOSPHER SCI RES CTR,ALBANY,NY 12205. RI Pleim, Jonathan Pleim/C-1331-2017 OI Pleim, Jonathan Pleim/0000-0001-6190-6082 NR 30 TC 154 Z9 164 U1 0 U2 10 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD, ENGLAND OX5 1GB SN 0004-6981 J9 ATMOS ENVIRON A-GEN PD APR PY 1992 VL 26 IS 6 BP 965 EP 981 DI 10.1016/0960-1686(92)90028-J PG 17 WC Environmental Sciences; Meteorology & Atmospheric Sciences SC Environmental Sciences & Ecology; Meteorology & Atmospheric Sciences GA HJ437 UT WOS:A1992HJ43700002 ER PT J AU SMITH, MK AF SMITH, MK TI REGIONAL DIFFERENCES IN OTOLITH MORPHOLOGY OF THE DEEP SLOPE RED SNAPPER ETELIS-CARBUNCULUS SO CANADIAN JOURNAL OF FISHERIES AND AQUATIC SCIENCES LA English DT Article ID FISH OTOLITHS; SHAPE-ANALYSIS; GROWTH; ULTRASTRUCTURE AB Sagittal otoliths from four populations of the Pacific deep slope red snapper Etelis carbunculus Cuvier were compared using Fourier descriptors and other shape indices, linear proportions, and dry weight. Otoliths from Hawaii, Vanuatu, Fiji and French Polynesia and a small number from the Commonwealth of the Northern Marianas Islands (NMI) were examined. Regional shape and weight characteristics were distinguishable, despite the wide range of individual variation and limited available size range from some regions. Size-specific differences in otolith shape were found for the four regions for which a sufficient sample was available. Otoliths from Hawaii, French Polynesia, and NMI showed a significant shape affinity. Otoliths from Fiji and Vanuatu were similarly shaped and were distinct from those from the other three regions. Interregional otolith shape affinities for the stocks examined parallel similarities in maximum size and growth rate from the literature, suggesting that growth rate may influence otolith shape. Observed trends in otolith weight as a function of fish length support growth-related regional differences in otolith shape. C1 NOAA,NATL MARINE FISHERIES SERV,SW FISHERIES SCI CTR,HONOLULU LAB,HONOLULU,HI 96822. NR 43 TC 55 Z9 65 U1 1 U2 7 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 1992 VL 49 IS 4 BP 795 EP 804 DI 10.1139/f92-090 PG 10 WC Fisheries; Marine & Freshwater Biology SC Fisheries; Marine & Freshwater Biology GA HL305 UT WOS:A1992HL30500019 ER PT J AU BRILL, RW BUSHNELL, PG JONES, DR SHIMIZU, M AF BRILL, RW BUSHNELL, PG JONES, DR SHIMIZU, M TI EFFECTS OF ACUTE TEMPERATURE-CHANGE, INVIVO AND INVITRO, ON THE ACID-BASE STATUS OF BLOOD FROM YELLOWFIN TUNA (THUNNUS-ALBACARES) SO CANADIAN JOURNAL OF ZOOLOGY-REVUE CANADIENNE DE ZOOLOGIE LA English DT Article ID TROUT SALMO-GAIRDNERI; KATSUWONUS-PELAMIS BLOOD; SKIPJACK TUNA; CHANNEL CATFISH; CARBON-DIOXIDE; FISH; PH; THERMOREGULATION; EXERCISE AB In most fishes, blood acid - base regulation following a temperature change involves active adjustments of gill ion-exchange rates which take hours or days to complete. Previous studies have shown that isolated blood from skipjack tuna, Katsuwonus pelamis, and albacore, Thunnus alalunga, had rates of pH change with temperature (in the open system) equivalent to those necessary to retain net protein charge in vivo (almost-equal-to -0.016-DELTA-pH . degrees-C-1). It was postulated that this is due to protons leaving the hemoglobin combining with plasma bicarbonate (HCO3-), which is removed as gaseous CO2, and that this ability evolved so that tunas need not adjust gill ion-exchange rates to regulate blood pH appropriately following ambient temperature changes. We reexamined this phenomenon using blood and separated plasma from yellowfin tuna, Thunnus albacares. Unlike previous studies, our CO2 levels (0.5 and 1.5 % CO2) span those seen in yellowfin tuna arterial and venous blood. Various bicarbonate concentrations ([HCO3-]) were obtained by collecting blood from fully rested as well as vigorously exercised fish. We use our in vitro data to calculate basic physiochemical parameters for yellowfin tuna blood: nonbicarbonate buffering (beta), the apparent first dissociation constant of carbonic acid (pK(app)), and CO2 Solubility (alpha-CO2). We also determined the effects of acute temperature change on arterial pH, [HCO3-], and partial pressures of O2 and CO2 in vivo. The pH shift of yellowfin tuna blood subjected to a closed-system temperature change did not differ from previous studies of other teleosts (almost-equal-to -0.016-DELTA-pH . degrees-C-1). The pH shift in blood subjected to open-system temperature change was Pco2 dependent and lower than that in skipjack tuna or albacore blood in vitro, but identical with that seen in yellowfin tuna blood in vivo. However, pH adjustments in vivo were caused by changes in both [HCO3-] and Pco2. The exact mechanisms responsible for these changes remain to be elucidated. C1 UNIV BRITISH COLUMBIA,DEPT ZOOL,VANCOUVER V6T 2A9,BC,CANADA. UNIV CALIF IRVINE,DEPT ECOL & EVOLUT BIOL,IRVINE,CA 92717. RP BRILL, RW (reprint author), NOAA,NATL MARINE FISHERIES SERV,SW FISHERIES SCI CTR HONOLULU LAB,2570 DOLE ST,HONOLULU,HI 96822, USA. NR 43 TC 7 Z9 7 U1 2 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 APR PY 1992 VL 70 IS 4 BP 654 EP 662 DI 10.1139/z92-098 PG 9 WC Zoology SC Zoology GA JB043 UT WOS:A1992JB04300004 ER PT J AU ZIEGLER, RG SUBAR, AF CRAFT, NE URSIN, G PATTERSON, BH GRAUBARD, BI AF ZIEGLER, RG SUBAR, AF CRAFT, NE URSIN, G PATTERSON, BH GRAUBARD, BI TI DOES BETA-CAROTENE EXPLAIN WHY REDUCED CANCER RISK IS ASSOCIATED WITH VEGETABLE AND FRUIT INTAKE SO CANCER RESEARCH LA English DT Article; Proceedings Paper CT CONF ON NUTRITION AND CANCER CY APR 17-19, 1991 CL ATLANTA, GA SP AMER CANC SOC, CTR DIS CONTROL, EMORY UNIV, NCI ID DIETARY VITAMIN-A; LUNG-CANCER; SUBSEQUENT RISK; SEROLOGIC PRECURSORS; FOLLOW-UP; SERUM RETINOL; COLON CANCER; NEW-JERSEY; WHITE MEN; GREEN AB Increased intake of vegetables, fruits, and carotenoids and elevated blood levels of beta-carotene are consistently associated with reduced risk of lung cancer in epidemiologic studies. Epidemiologic research also suggests that carotenoids may reduce the risk of other cancers, although the evidence is less extensive and consistent. The simplest explanation is that beta-carotene is protective. However, the possible roles of other carotenoids, other constituents of vegetables and fruits, and associated dietary patterns have not been adequately explored. To evaluate these alternative hypotheses, we are undertaking three lines of research. (a) With dietary data from the 1987 National Health Interview Survey and the 1982-1984 Epidemiologic Follow-up of the first National Health and Nutrition Examination Study, we have determined which food groups and nutrients are highly correlated with vegetable and fruit intake. (b) We have developed and characterized a liquid chromatography method for optimal recovery and resolution of the common carotenoids in blood, specifically lutein, zeaxanthin, beta-cryptoxanthin, lycopene, alpha-carotene, and beta-carotene. (c) In a population-based case-control study of lung cancer in white men in New Jersey, we are assessing whether estimates of the intake of the individual carotenoids might produce stronger inverse associations than estimates of provitamin A carotenoids based on current food composition tables. C1 NCI,DIV CANC PREVENT & CONTROL,SURVEILLANCE PROGRAM,APPL RES BRANCH,BETHESDA,MD 20892. NATL INST STAND & TECHNOL,CHEM SCI & TECHNOL LAB,ORGAN ANALYT RES DIV,GAITHERSBURG,MD 20899. UNIV CALIF LOS ANGELES,SCH PUBL HLTH,DEPT EPIDEMIOL,LOS ANGELES,CA 90024. NCI,DIV CANC PREVENT & CONTROL,BIOMETRY BRANCH,BETHESDA,MD 20892. RP ZIEGLER, RG (reprint author), NCI,DIV CANC ETIOL,EPIDEMIOL & BIOSTAT PROGRAM,BETHESDA,MD 20892, USA. NR 51 TC 88 Z9 88 U1 0 U2 2 PU AMER ASSOC CANCER RESEARCH PI PHILADELPHIA PA PUBLIC LEDGER BLDG, SUITE 816, 150 S. INDEPENDENCE MALL W., PHILADELPHIA, PA 19106 SN 0008-5472 J9 CANCER RES JI Cancer Res. PD APR 1 PY 1992 VL 52 IS 7 SU S BP S2060 EP S2066 PG 7 WC Oncology SC Oncology GA HL808 UT WOS:A1992HL80800009 ER PT J AU ROWE, GT PHOEL, WC AF ROWE, GT PHOEL, WC TI NUTRIENT REGENERATION AND OXYGEN-DEMAND IN BERING SEA CONTINENTAL-SHELF SEDIMENTS SO CONTINENTAL SHELF RESEARCH LA English DT Article ID MIDDLE ATLANTIC BIGHT; MARINE-SEDIMENTS; ORGANIC-MATTER; PHYTOPLANKTON GROWTH; CHUKCHI SEAS; AMINO-ACIDS; CARBON; COASTAL; NITROGEN; CONSUMPTION AB Measurements of seabed oxygen demand and nutrient regeneration were made on continental shelf sediments in the southeast Bering Sea from 1 to 15 June 1981. The mean seabed oxygen demand was relatively modest (267-mu-M O2 m-2 h-1), equivalent to a utilization of 60 mg organic carbon m-2 day-1. The seasonal build up of ammonium over the mid-shelf domain was generated at least in part by the bottom biota, as previously suggested (WHITLEDGE et al., 1986, Continental Shelf Research, 5, 109-132), but on the outer shelf nitrate replaced ammonium as the dominant inorganic nitrogen compound that was regenerated from the sediments. Comparison of oxygen consumption with the organic matter in sedimenting particulate matter (sampled with sediment traps) could imply that benthic processes were not accounting for the fate of considerable quantities of organic matter. Benthic oxygen demand rates, however, probably lag behind the input of the spring bloom to the bottom, thus extending the remineralization process out over time. Consumption by small microheterotrophs in the water column was also a likely sink, although shelf export and advective transport north were possible as well. Estimated nitrification rates in surface sediments could account for only a small fraction of the abrupt increase in nitrate observed in the water column over the shelf just prior to the spring bloom. C1 NOAA,NATL MARINE FISHERIES SERV,SANDY HOOK LAB,HIGHLANDS,NJ 07732. RP ROWE, GT (reprint author), TEXAS A&M UNIV SYST,COLLEGE STN,TX 77843, USA. NR 47 TC 20 Z9 21 U1 1 U2 8 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD, ENGLAND OX5 1GB SN 0278-4343 J9 CONT SHELF RES JI Cont. Shelf Res. PD APR PY 1992 VL 12 IS 4 BP 439 EP 449 DI 10.1016/0278-4343(92)90085-X PG 11 WC Oceanography SC Oceanography GA HM301 UT WOS:A1992HM30100001 ER PT J AU TZIPERMAN, E THACKER, WC BRYAN, K AF TZIPERMAN, E THACKER, WC BRYAN, K TI COMPUTING THE STEADY OCEANIC CIRCULATION USING AN OPTIMIZATION APPROACH SO DYNAMICS OF ATMOSPHERES AND OCEANS LA English DT Article ID MODEL AB The traditional method for computing the steady oceanic circulation has been by stepping an oceanic model forward in time until transients are damped by friction. An alternative method, which has the potential for being more economical is to minimize the sum of the squares of the residuals of the steady model equations. A variety of algorithms might be considered for computing the minimum; attention here is focused on preconditioned conjugate-gradient descent with the gradient computed using an adjoint model. The choice of variables, i.e. the preconditioning transformation used in the optimization process, is found to be critical to the efficiency of the method. An appropriate preconditioning transformation can be suggested by a heuristic analysis similar to that commonly used to test the stability of numerical models. The method is demonstrated within the context of the barotropic vorticity equation. C1 ATLANTIC OCEANOG & METEOROL LAB, MIAMI, FL 33149 USA. GEOPHYS FLUID DYNAM LAB, PRINCETON, NJ 08542 USA. RP TZIPERMAN, E (reprint author), WEIZMANN INST SCI, IL-76100 REHOVOT, ISRAEL. RI Thacker, Carlisle/I-3813-2013 OI Thacker, Carlisle/0000-0002-9285-8826 NR 16 TC 10 Z9 10 U1 0 U2 1 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0377-0265 EI 1872-6879 J9 DYNAM ATMOS OCEANS JI Dyn. Atmos. Oceans PD APR PY 1992 VL 16 IS 5 BP 379 EP 403 DI 10.1016/0377-0265(92)90016-M PG 25 WC Geochemistry & Geophysics; Meteorology & Atmospheric Sciences; Oceanography SC Geochemistry & Geophysics; Meteorology & Atmospheric Sciences; Oceanography GA HP061 UT WOS:A1992HP06100003 ER PT J AU MCCAIN, BB CHAN, SL KRAHN, MM BROWN, DW MYERS, MS LANDAHL, JT PIERCE, S CLARK, RC VARANASI, U AF MCCAIN, BB CHAN, SL KRAHN, MM BROWN, DW MYERS, MS LANDAHL, JT PIERCE, S CLARK, RC VARANASI, U TI CHEMICAL CONTAMINATION AND ASSOCIATED FISH DISEASES IN SAN-DIEGO BAY SO ENVIRONMENTAL SCIENCE & TECHNOLOGY LA English DT Article ID SOLE PAROPHRYS-VETULUS; ENGLISH SOLE; PUGET-SOUND; SOUTHERN-CALIFORNIA; AROMATIC-HYDROCARBONS; ORGANIC CONTAMINANTS; GENYONEMUS-LINEATUS; COASTAL WATERS; WHITE CROAKER; FIN EROSION AB Chemical pollution at sites in or near San Diego Bay was investigated between 1984 and 1988. The mean concentrations of selected polychlorinated biphenyls (PCBs), metals (e.g., copper and lead), and aromatic hydrocarbons in sediments from sites in the southern and central portions of the bay were significantly higher (p less-than-or-equal-to 0.05) than those in sediment samples from nearby nonurban sites. Mean concentrations of PCBs in liver tissue and of selected aromatic compounds (e.g., aromatic hydrocarbons) and their metabolites in bile were also significantly higher in white croaker (Genyonemus lineatus), barred sand bass (Paralabrax nebulifer), and black croaker (Cheilotrema saturnum) from one or more sites within the bay compared to those from the nonurban sites. In addition, prevalences of fin erosion in white croaker, barred sand bass, and black croaker and of liver neoplasms in black croaker from sites in the bay were significantly higher than in individuals of the same species from nonurban sites. RP MCCAIN, BB (reprint author), NOAA,NATL MARINE FISHERIES SERV,NW FISHERIES CTR,DIV ENVIRONM CONSERVAT,2725 MONTLAKE BLVD E,SEATTLE,WA 98112, USA. NR 48 TC 52 Z9 53 U1 0 U2 8 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 SN 0013-936X J9 ENVIRON SCI TECHNOL JI Environ. Sci. Technol. PD APR PY 1992 VL 26 IS 4 BP 725 EP 733 DI 10.1021/es00028a009 PG 9 WC Engineering, Environmental; Environmental Sciences SC Engineering; Environmental Sciences & Ecology GA HL936 UT WOS:A1992HL93600016 ER PT J AU BOWERS, MJ AF BOWERS, MJ TI ANNUAL REPRODUCTIVE-CYCLE OF OOCYTES AND EMBRYOS OF YELLOWTAIL ROCKFISH SEBASTES-FLAVIDUS (FAMILY SCORPAENIDAE) SO FISHERY BULLETIN LA English DT Article AB Female yellowtail rockfish Sebastes flavidus, a viviparous species employing intralumenal gestation following fertilization of ovulated eggs, were caught from Cordell Bank (seamount 20 miles west of Pt. Reyes, central California) on a monthly basis from May 1985 through April 1986 to determine their annual reproductive cycle. Since histological methods provide precise and detailed information, this method was employed to (1) examine oocytes and embryos to describe developmental stages, and (2) provide temporal assessment of the annual reproductive cycle. The description and staging scheme developed provide a basis to compare reproductive developmental patterns between cycles and populations. Oogonia (Stage I) and early perinucleolus (Stage II) oocytes were present in samples from all months. Progressive growth of oocytes from early- to late perinucleolus (Stage III) was evident in spent and recovering ovaries, indicating the end of a reproductive year and the beginning of a new reproductive cycle. Initial yolk accumulation (Stage IV) occurred in July, and final yolk accumulation (Stage V) was predominant from September through January. In February, the majority of samples displayed fertilized ova in early-celled stages of embryonic development. Gestation continued for about 30 days with parturition occurring between January and March. Mature oocytes were also collected in March, suggesting the Cordell Bank yellowtail population has a prolonged reproductive season extending into April. RP BOWERS, MJ (reprint author), NOAA,NATL MARINE FISHERIES SERV,SW FISHERIES SCI CTR,TIBURON LAB,3150 PARADISE DR,TIBURON,CA 94920, USA. NR 22 TC 22 Z9 24 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 1992 VL 90 IS 2 BP 231 EP 242 PG 12 WC Fisheries SC Fisheries GA JF227 UT WOS:A1992JF22700002 ER PT J AU BULLOCK, LH MURPHY, MD GODCHARLES, MF MITCHELL, ME AF BULLOCK, LH MURPHY, MD GODCHARLES, MF MITCHELL, ME TI AGE, GROWTH, AND REPRODUCTION OF JEWFISH EPINEPHELUS-ITAJARA IN THE EASTERN GULF OF MEXICO SO FISHERY BULLETIN LA English DT Article ID SOUTH-ATLANTIC BIGHT; SNOWY GROUPER; PARAMETERS; MORTALITY AB We sampled jewfish from recreational and commercial catches in the eastern Gulf of Mexico from November 1977 to January 1990 to obtain life history information. A single annual minimum in mean marginal increment ratios during May-August supported the hypothesis that jewfish up to at least age 10 can be aged by counting the opaque marks observed on otolith sections. Annual opaque mark formation was observed for a 3- and a 4-year-old jewfish using oxytetracycline (OTC) reference marks on otoliths (sagittae). Male jewfish (N 41) ranged 3-26 years old; females, 0-37 years (N 85). Growth was similar for males and females, averaging > 100 mm/year through age 6, then slowing to about 30 mm/year by age 15, and finally declining to < 10 mm/year after age 25. Observed total length and age data were described well by the following von Bertalanffy growth model: total length (mm) = 2006 (1 - e (-0.126(age(yrs)+0.49))). Jewfish spawned from June through December, with peak activity from July through September. Male jewfish matured at about 1100-1150 mm when 4-6 years old; females matured at 1200-1350 mm when 6 or 7 years old. The extensive overlap of length and age distributions of males and females, and the slight differences between their sizes and ages at maturity, prevent us from designating jewfish as a protogynous hermaphrodite. No transitional individuals were found. Their relatively slow growth, longevity, and behavioral characteristics, such as the tendency to form spawning aggregations, make jewfish populations highly susceptible to overfishing. C1 NOAA,NATL MARINE FISHERIES SERV,SE REG,ST PETERSBURG,FL 33702. FLORIDA DEPT NAT RESOURCES,FLORIDA MARINE RES INST,PORT CHARLOTTE,FL 33953. RP BULLOCK, LH (reprint author), FLORIDA DEPT NAT RESOURCES,FLORIDA MARINE RES INST,100 8TH AVE SE,ST PETERSBURG,FL 33701, USA. NR 35 TC 82 Z9 101 U1 1 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 APR PY 1992 VL 90 IS 2 BP 243 EP 249 PG 7 WC Fisheries SC Fisheries GA JF227 UT WOS:A1992JF22700003 ER PT J AU DORN, MW AF DORN, MW TI DETECTING ENVIRONMENTAL COVARIATES OF PACIFIC WHITING MERLUCCIUS-PRODUCTUS GROWTH USING A GROWTH-INCREMENT REGRESSION-MODEL SO FISHERY BULLETIN LA English DT Article ID DENSITY-DEPENDENT GROWTH; VANCOUVER ISLAND; GENUS SEBASTES; FOOD-HABITS; POPULATION; DYNAMICS; AGE; LENGTH; SHELF; HAKE AB The growth patterns of Pacific whiting Merluccius productus, also known as Pacific hake, were examined for the period 1978-88 using fishery-based estimates of length-at-age. Mean length-at-age and a delta method variance estimate of mean length-at-age were computed for geographic and temporal strata in the U.S. fishery. These calculations took into account the two-phase sampling design used to sample the catch. A factorial analysis of variance of length found significant differences due to age, year, region, sex, and time-period during the fishery. Length increases with age and season. Pacific whiting found in the north are larger, and females are larger than males. The mean length-at-age began declining in 1978, and reached a minimum in 1984. From 1984 to 1986, there was a slight rebound in length-at-age, but after 1986 length-at-age again declined. To investigate the influence of population density and environmental covariates on annual growth, a generalized form of the von Bertalanffy growth model was developed. Deviations from a baseline model for sex-specific asymptotic growth were significantly correlated with changes in sea-surface temperature and adult biomass. Regression results indicate that a 0.5-degrees-C increase in mean summer sea-surface temperature would reduce annual growth by 24% at age 1 and 12% at age 4. In contrast, the effect of adult biomass on annual growth becomes greater with age. An increase of 200,000 metric tons (approximately 10% of the mean population biomass) would reduce annual growth by 5% at age 4 and by 10% at age 7. It is proposed that the effect of population density is greater for the older Pacific whiting because their diet has shifted from euphausiids, whose abundance is closely coupled with environmental processes, towards fish species with multiyear life cycles that can be affected by intense Pacific whiting predation. RP DORN, MW (reprint author), NOAA,NATL MARINE FISHERIES SERV,ALASKA FISHERIES SCI CTR,SEATTLE,WA 98115, USA. NR 40 TC 21 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 1992 VL 90 IS 2 BP 260 EP 275 PG 16 WC Fisheries SC Fisheries GA JF227 UT WOS:A1992JF22700005 ER PT J AU PARRACK, ML AF PARRACK, ML TI ESTIMATING STOCK ABUNDANCE FROM SIZE DATA SO FISHERY BULLETIN LA English DT Article ID AT-AGE DATA; FREQUENCY DATA; GROWTH-MODEL; LENGTH; PARAMETERS; ALGORITHM; MIXTURES AB The projection of resource production and the effect of removals on fisheries populations are based on abundance estimates, particularly estimates of the most current abundance. Monte Carlo methods were used to investigate a size-based method of estimating abundance for instances where the age of caught fish cannot be established, but where size samples and a growth schedule exist. Neither process variability (recruitment dates, growth rates, and unobserved change rates) nor sampling error (catch estimation, growth rate estimation, and relative abundance sampling) adversely affected estimation, although low sampling intensities often decreased precision. Abundances of recently recruited fish too small to occur in relative abundance samples more than once were estimated with large uncertainty. Inappropriately wide size-class widths caused uncertain abundance estimates of larger size-classes. However, if size-classes were of suitable width, the abundance of fish large enough to occur in abundance samples more than once were accurately and precisely estimated even in cases of high process variability and small sample sizes. Sampling gear efficiency (catchability) coefficients were often estimated without large bias but imprecisely. The exponent of the unobserved change rate (including natural mortality) was estimated precisely, but estimates were often biased. High correlations between estimates of the unobserved change rate and sampling gear efficiencies were not often observed. Estimation characteristics were unlike those based on virtual population analysis calculations. Maximum-likelihood estimates of the most recent abundances were accurate and precise, yet calculations of historical abundances were biased and extremely imprecise. RP PARRACK, ML (reprint author), NOAA,NATL MARINE FISHERIES SERV,SE FISHERIES SCI CTR,MIAMI LAB,MIAMI,FL 33149, USA. NR 83 TC 0 Z9 0 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 APR PY 1992 VL 90 IS 2 BP 302 EP 325 PG 24 WC Fisheries SC Fisheries GA JF227 UT WOS:A1992JF22700008 ER PT J AU RAJAGURU, A AF RAJAGURU, A TI BIOLOGY OF 2 COOCCURRING TONGUEFISHES, CYNOGLOSSUS-AREL AND C-LIDA (PLEURONECTIFORMES, CYNOGLOSSIDAE), FROM INDIAN WATERS SO FISHERY BULLETIN LA English DT Article ID CONTINENTAL-SLOPE; GROWTH; FOOD; AGE; AMPHIPODS; ATLANTIC; PISCES; RISE; SOLE AB Feeding ecology, age and growth, length-weight relationships, and reproductive biology of two species of tonguefishes, Cynoglossus arel and C. lida, from Porto Novo, southeast coast of India, were studied during October 1981-September 1982. These tonguefishes are benthophagus; adults feed primarily on polychaetes, while juveniles more often consume smaller prey such as hyperiid amphipods and copepods. A negative correlation between spawning activity and gastrosomatic index/hepatosomatic index was noted for C. arel. In C. lida, a higher percentage of empty stomachs was observed in males than in females. Age and growth of these tonguefishes were determined by three methods, viz, (1) Petersen method, (2) probability plot, and (3) von Bertalanffy's equation. Rate of growth from the time of hatching through the first year is higher than that of older year-classes. Both species reach commercial size during their 2d and 3d year, and have a life-span of 3-4 years. Value of L infinity (theoretical maximum attainable length) is 570 mm for male and 615 mm for female C. arel, and 335 mm for male and 340 mm for female C. lida. Analyses of the length-weight relationship showed a significant difference in length-weight slopes of male and female C. arel. Due to gonad development, mature female C. lida deviated significantly from the 'cube law.' Cynoglossus arel and C. lida have prolonged spawning periods of 10 months, with a spawning peak in January and September, respectively. Individuals spawn only once during each season. Both sexes of both species attain first sexual maturity during the 2d year. In male C. lida, higher values of the gonadosomatic index (GSI) in September indicate the occurrence of fully-mature specimens during this period. A rise in Kn values (relative condition factor) corresponds with a rise in gonadal activity in female C. arel. The correlation coefficient shows that fecundity in C. arel is correlated with total length, total weight, ovary length, and ovary weight, whereas in C. lida it is correlated only with ovary length and ovary weight. RP RAJAGURU, A (reprint author), NOAA,NATL MUSEUM NAT HIST,NATL MARINE FISHERIES SERV,SYSTEMAT LAB,WASHINGTON,DC 20560, USA. NR 80 TC 17 Z9 17 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 1992 VL 90 IS 2 BP 328 EP 367 PG 40 WC Fisheries SC Fisheries GA JF227 UT WOS:A1992JF22700009 ER PT J AU SOMERTON, DA KOBAYASHI, DR AF SOMERTON, DA KOBAYASHI, DR TI INVERSE METHOD FOR MORTALITY AND GROWTH ESTIMATION - A NEW METHOD FOR LARVAL FISHES SO FISHERY BULLETIN LA English DT Article ID EARLY LIFE-HISTORY; NORTHERN ANCHOVY; ENGRAULIS-MORDAX; AGE; GULF; INCREMENTS; SURVIVAL; MEXICO; RATES; SIZE AB The inverse method for mortality and growth estimation (IMMAGE) is a new approach to obtain unbiased estimates of mortality and growth parameters for larval fishes from length-frequency data biased by the size selectivity of plankton nets. The performance of IMMAGE is compared with methods which attempt to eliminate selection bias from sampled length-frequencies. Using Monte Carlo simulations, IMMAGE estimates growth and mortality parameters that are more accurate and precise than those produced by other methods. C1 NOAA,NATL MARINE FISHERIES SERV,SW FISHERIES SCI CTR,HONOLULU LAB,HONOLULU,HI 96822. RP SOMERTON, DA (reprint author), NOAA,NATL MARINE FISHERIES SERV,ALASKA FISHERIES SCI CTR,SEATTLE,WA 98115, USA. NR 25 TC 7 Z9 7 U1 1 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 1992 VL 90 IS 2 BP 368 EP 375 PG 8 WC Fisheries SC Fisheries GA JF227 UT WOS:A1992JF22700010 ER PT J AU HETTLER, WF AF HETTLER, WF TI CORRELATION OF WINTER TEMPERATURE AND LANDINGS OF PINK SHRIMP PENAEUS-DUORARUM IN NORTH-CAROLINA SO FISHERY BULLETIN LA English DT Note RP HETTLER, WF (reprint author), NOAA,NATL MARINE FISHERIES SERV,SE FISHERIES SCI CTR,BEAUFORT LAB,BEAUFORT,NC 28516, USA. NR 3 TC 13 Z9 13 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 1992 VL 90 IS 2 BP 405 EP 406 PG 2 WC Fisheries SC Fisheries GA JF227 UT WOS:A1992JF22700014 ER PT J AU SALVADO, CAM KLEIBER, P DIZON, AE AF SALVADO, CAM KLEIBER, P DIZON, AE TI OPTIMAL COURSE BY DOLPHINS FOR DETECTION AVOIDANCE SO FISHERY BULLETIN LA English DT Note RP SALVADO, CAM (reprint author), NOAA,NATL MARINE FISHERIES SERV,SW FISHERIES SCI CTR,POB 271,LA JOLLA,CA 92038, USA. NR 7 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 1992 VL 90 IS 2 BP 417 EP 420 PG 4 WC Fisheries SC Fisheries GA JF227 UT WOS:A1992JF22700017 ER PT J AU ENEVA, M HAMBURGER, MW POPANDOPULO, GA AF ENEVA, M HAMBURGER, MW POPANDOPULO, GA TI SPATIAL-DISTRIBUTION OF EARTHQUAKES IN AFTERSHOCK ZONES OF THE GARM REGION, SOVIET CENTRAL-ASIA SO GEOPHYSICAL JOURNAL INTERNATIONAL LA English DT Article DE AFTERSHOCKS; GARM REGION; PAIR ANALYSIS; SOVIET CENTRAL ASIA; SPATIAL DISTRIBUTION ID PAIR ANALYSIS STATISTICS; LINK CLUSTER-ANALYSIS; SAN-ANDREAS FAULT; B-VALUE; SEISMICITY; CALIFORNIA AB We examined the spatial distribution of earthquakes in aftershock zones of eight M4.5 to M6.3 earthquakes that occurred during the period January 1969-February 1987 in the Garm region of Soviet Central Asia. This seismically active region is a part of the collisional plate boundary between the Indian and Eurasian plates. Spatial patterns in earthquake distribution were studied using the technique of pair analysis, which is based on a quantitative comparison between observed and randomly simulated distributions of interevent distances. Similar to our previous findings from other seismically active areas of various scales and tectonic settings, we show that the spatial distribution of earthquakes in all of the aftershock zones studied is characterized by significant non-random features. Most prominent of the spatial patterns observed is spatial clustering at short interevent distances. The degree of non-randomness is usually higher for the aftershocks than for the background seismicity (i.e., the remainder of the catalogue, after space-time clusters have been removed). In some of the study areas the spatial distribution of aftershocks appears to be self-similar in magnitude, but in most cases is not self-similar with respect to the size of the study areas. More specifically, the seismic activity in the smallest subareas (of only few kilometres in size) exhibits a higher degree of spatial clustering than the activity in larger subareas. Furthermore, some of the spatial patterns observed change systematically in time. One such change is the gradual increase of the degree of pre-shock clustering as the main event approaches. Other temporal features are observed during the aftershock sequences themselves, when the degree of spatial non-randomness often increases to a peak value and then gradually decreases reaching a reduced 'background level' at some time after the sequences are over. Some of the temporal changes observed are similar to patterns previously identified in central California aftershock areas. C1 ACAD SCI USSR, INST PHYS EARTH, MOSCOW 123810, USSR. NOAA, NATL GEOPHYS DATA CTR, BOULDER, CO 80303 USA. INDIANA UNIV, DEPT GEOL SCI, BLOOMINGTON, IN 47405 USA. NR 29 TC 16 Z9 16 U1 0 U2 0 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 APR PY 1992 VL 109 IS 1 BP 38 EP 53 DI 10.1111/j.1365-246X.1992.tb00077.x PG 16 WC Geochemistry & Geophysics SC Geochemistry & Geophysics GA HK680 UT WOS:A1992HK68000003 ER PT J AU KELLY, WR MURPHY, KE AF KELLY, WR MURPHY, KE TI DETERMINATION OF SULFUR IN SRM BAUXITE AND SEDIMENT SAMPLES BY ISOTOPE-DILUTION THERMAL IONIZATION MASS-SPECTROMETRY SO GEOSTANDARDS NEWSLETTER LA English DT Article AB The sulfur concentration has been determined in five bauxite and two sediment NIST Standard Reference Materials (SRM) by isotope dilution thermal ionization mass spectrometry (ID-TIMS). Two outside laboratories had indicated that the original certified values in the bauxites SRMs were too high by as much as 93 percent. The ID-TIMS determinations reported here confirm that the certified values on all bauxites contained a positive bias. The sulfur concentrations obtained in this study are the following (in mu-gS/g, dry weight basis): SRM 69b - 2208 +/- 25, SRM 696 - 601 +/- 8, SRM 697 - 308 +/- 7, SRM 698 - 575 +/- 16 and SRM 600 - 622 +/- 24. The values for the sediment samples are the following (in weight percent sulfur dry weight basis): SRM 2704 - 0.3970 +/- 0.0039 and SRM 1941 - 1.717 +/- 0.016. RP KELLY, WR (reprint author), NATL INST STAND & TECHNOL,CHEM SCI & TECHNOL LAB,GAITHERSBURG,MD 20899, USA. NR 10 TC 13 Z9 13 U1 1 U2 3 PU GEOSTANDARDS PI VANDOEUVRE NANCY PA 15 RUE NOTRE-DAME-DES-PAUVRES BP 20, 54501 VANDOEUVRE NANCY, FRANCE SN 0150-5505 J9 GEOSTANDARD NEWSLETT JI Geostand. Newsl. PD APR PY 1992 VL 16 IS 1 BP 3 EP 8 DI 10.1111/j.1751-908X.1992.tb00479.x PG 6 WC Geosciences, Multidisciplinary SC Geology GA HT024 UT WOS:A1992HT02400002 ER PT J AU PAL, BP GALLAWA, RL GOYAL, IC AF PAL, BP GALLAWA, RL GOYAL, IC TI LP11-MODE LEAKAGE LOSS IN COATED DEPRESSED CLAD FIBERS SO IEEE PHOTONICS TECHNOLOGY LETTERS LA English DT Article ID EFFECTIVE CUTOFF WAVELENGTH; SINGLE-MODE FIBER AB A quantitative investigation of the leakage loss spectrum of the LP11-mode in coated depressed index clad fibers is made using the matrix method. The study reveals oscillations similar to those seen in the measurement of cutoff wavelength. Our results do not agree with recently published results and a plausible explanation of the discrepancies is given. RP PAL, BP (reprint author), NATL INST STAND & TECHNOL,DIV ELECTROMAGNET TECHNOL,BOULDER,CO 80303, USA. NR 17 TC 2 Z9 2 U1 1 U2 1 PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017-2394 SN 1041-1135 J9 IEEE PHOTONIC TECH L JI IEEE Photonics Technol. Lett. PD APR PY 1992 VL 4 IS 4 BP 376 EP 378 DI 10.1109/68.127219 PG 3 WC Engineering, Electrical & Electronic; Optics; Physics, Applied SC Engineering; Optics; Physics GA HL339 UT WOS:A1992HL33900029 ER PT J AU WARD, BH BARTNIKAS, R VANBRUNT, RJ CHANGRONG, Q AF WARD, BH BARTNIKAS, R VANBRUNT, RJ CHANGRONG, Q TI DIGITAL-TECHNIQUES FOR PARTIAL DISCHARGE MEASUREMENTS SO IEEE TRANSACTIONS ON POWER DELIVERY LA English DT Article DE DIGITAL ANALYSIS; PARTIAL DISCHARGE; COMPUTER AIDED MEASUREMENT; POWERAPPARATUS ID STOCHASTIC PROPERTIES; POWER TRANSFORMERS; CORONA; LOCATION; COMPUTER AB The working group is addressing the subject of digital analysis of partial discharges (PD) in power apparatus. Included in its activities is a worldwide survey of ongoing research and a review of previous work in this area. Several papers are being prepared with emphasis on the post-measurement processing, analysis, and meaningful presentation of the PD signals, and the significance of the presentation as it relates to insulation degradation in various types of power apparatus. The papers describe currently accepted techniques using analog type instrumentation for detection and display, present critical reviews of these techniques for assessment of the qualification of power apparatus, and show the inadequacies of these methods in light of the new techniques using digital technology. This report is an excerpt, dealing with the general concepts of digital techniques in PD measurements, taken from that paper. The complete Bibliography used to date is presented at the end of this paper for further reading. C1 NATL INST STAND & TECHNOL, GAITHERSBURG, MD USA. XIAN JIAO TONG UNIV, XIAN, PEOPLES R CHINA. INST RECH HYDRO QUEBEC VARENNES, VARENNES, QUEBEC, CANADA. NR 105 TC 27 Z9 27 U1 0 U2 1 PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC PI PISCATAWAY PA 445 HOES LANE, PISCATAWAY, NJ 08855-4141 USA SN 0885-8977 EI 1937-4208 J9 IEEE T POWER DELIVER JI IEEE Trans. Power Deliv. PD APR PY 1992 VL 7 IS 2 BP 469 EP 479 DI 10.1109/61.127039 PG 11 WC Engineering, Electrical & Electronic SC Engineering GA HK197 UT WOS:A1992HK19700003 ER PT J AU PEREIRA, D SCALABRIN, A GALVAO, GP EVENSON, KM AF PEREIRA, D SCALABRIN, A GALVAO, GP EVENSON, KM TI (CD30H)-C-13 AND (CD30H)-C-12 OPTICALLY PUMPED BY A (CO2)-C-13 LASER - OBSERVATIONS AND ASSIGNMENTS OF FIR LASER LINES SO INTERNATIONAL JOURNAL OF INFRARED AND MILLIMETER WAVES LA English DT Article ID CD3OH; SPECTRA AB In this work we report the first observation of FIR laser lines from (CD3OH)-C-13 pumped by the (CO2)-C-13 isotope laser. Using the same pump we have also found 3 new lines from (CD3OH)-C-12. Tentative assignments for the absorption and emission transitions of the observed lines are also proposed. C1 NATL INST STAND & TECHNOL,BOULDER,CO 80303. RP PEREIRA, D (reprint author), UNICAMP,INST FIS,BR-13081 CAMPINAS,BRAZIL. RI Inst. of Physics, Gleb Wataghin/A-9780-2017 NR 22 TC 17 Z9 17 U1 0 U2 0 PU PLENUM PUBL CORP PI NEW YORK PA 233 SPRING ST, NEW YORK, NY 10013 SN 0195-9271 J9 INT J INFRARED MILLI JI Int. J. Infrared Millimeter Waves PD APR PY 1992 VL 13 IS 4 BP 497 EP 506 DI 10.1007/BF01010708 PG 10 WC Engineering, Electrical & Electronic; Optics; Physics, Applied SC Engineering; Optics; Physics GA HM054 UT WOS:A1992HM05400009 ER PT J AU RIDDER, SD OSELLA, SA ESPINA, PI BIANCANIELLO, FS AF RIDDER, SD OSELLA, SA ESPINA, PI BIANCANIELLO, FS TI INTELLIGENT CONTROL OF PARTICLE-SIZE DISTRIBUTION DURING GAS ATOMIZATION SO INTERNATIONAL JOURNAL OF POWDER METALLURGY LA English DT Article ID POWDER AB The National Institute of Standards and Technology's (NIST, formerly NBS) program on Intelligent Processing of Metal Powders is a multidisciplinary research initiative investigating the application of expert system control techniques to improve the state-of-the-art of metal powder manufacturing. This research initiative has focused on those aspects of the gas atomization process that relate to process control including fluid dynamics, process parameterization and particle size sensing. The process controller incorporates the results of these studies into a multiple level I/O command interface. The modular nature of both the hardware and software design is adaptable to other particulate producing equipment. C1 NATL INST STAND & TECHNOL,DIV FACTORY AUTOMAT SYST,GAITHERSBURG,MD 20899. NATL INST STAND & TECHNOL,DIV PROC MEASUREMENT,GAITHERSBURG,MD 20899. RP RIDDER, SD (reprint author), NATL INST STAND & TECHNOL,DIV MET,GAITHERSBURG,MD 20899, USA. NR 17 TC 12 Z9 12 U1 0 U2 0 PU AMER POWDER METALLURGY INST PI PRINCETON PA 105 COLLEGE ROAD EAST, PRINCETON, NJ 08540 SN 0888-7462 J9 INT J POWDER METALL JI Int. J. Powder Metall. PD APR PY 1992 VL 28 IS 2 BP 133 EP & PG 0 WC Metallurgy & Metallurgical Engineering SC Metallurgy & Metallurgical Engineering GA HQ870 UT WOS:A1992HQ87000003 ER PT J AU SCHAEFER, RJ AF SCHAEFER, RJ TI INTELLIGENT PROCESSING IN HOT ISOSTATIC PRESSING SO INTERNATIONAL JOURNAL OF POWDER METALLURGY LA English DT Article ID DIAGRAMS AB Consolidation of metal powders by hot isostatic pressing can be made more economical and reliable by combining recent advances in process models, advances sensors, and intelligent control systems. Depending upon the specific problems to be overcome, the primary benefits may derive from refinement of the process model, optimization of the workplace design and process schedule, or feedback control based on sample characteristics. RP SCHAEFER, RJ (reprint author), NATL INST STAND & TECHNOL,DIV MET,GAITHERSBURG,MD 20899, USA. NR 15 TC 3 Z9 3 U1 0 U2 1 PU AMER POWDER METALLURGY INST PI PRINCETON PA 105 COLLEGE ROAD EAST, PRINCETON, NJ 08540 SN 0888-7462 J9 INT J POWDER METALL JI Int. J. Powder Metall. PD APR PY 1992 VL 28 IS 2 BP 161 EP & PG 0 WC Metallurgy & Metallurgical Engineering SC Metallurgy & Metallurgical Engineering GA HQ870 UT WOS:A1992HQ87000005 ER PT J AU MINNIS, P HECK, PW YOUNG, DF FAIRALL, CW SNIDER, JB AF MINNIS, P HECK, PW YOUNG, DF FAIRALL, CW SNIDER, JB TI STRATOCUMULUS CLOUD PROPERTIES DERIVED FROM SIMULTANEOUS SATELLITE AND ISLAND-BASED INSTRUMENTATION DURING FIRE SO JOURNAL OF APPLIED METEOROLOGY LA English DT Article ID LIQUID WATER; PARAMETERIZATION; VARIABILITY; RADIOMETER; PROJECT; MODEL AB Cloud parameters derived from visible and infrared window data from the Geostationary Operational Environmental Satellite (GOES) are compared to corresponding properties determined from instrumentation on San Nicolas Island off the coast of California during the First ISCCP Regional Experiment (FIRE) marine stratocumulus intensive field observations period in July 1987. Mean cloud amounts derived by applying the hybrid bispectral threshold method to the GOES data were 5% less than the island ceilometer measurements. Examination of the satellite imagery revealed that the apparent bias can be explained by the persistence of the clouds over the northwest part of the island during periods of clearing around the island. Diurnal variations in the cloud cover were very significant; minimum cloudiness occurred during the late afternoon and maximum cloudiness early in the morning. The satellite retrievals track this variation quite well. Satellite-derived mean cloud-top height is 53 m lower than that observed from the surface. Relationships were established between the satellite-derived cloud optical depth and two surface-observed quantities: cloud liquid water path and cloud thickness. Simultaneous observations of liquid water path and satellite-derived cloud optical depth were used to infer effective cloud-droplet radius, resulting in good agreement with correlative data. The diurnal variations in cloud amount are accompanied by changes in cloud thickness, cloud-top height, cloud liquid water path, and effective droplet size. These observations provide the most complete picture, to date, of the diurnal cycle of marine stratocumulus clouds, confirming previous satellite-based inferences of the diurnal behavior of marine stratocumulus at larger scales. Because of the limited area of the observations, further comparisons should be performed over other regions containing climatologically significant marine stratocumulus clouds. C1 LOCKHEED ENG & SCI CO,HAMPTON,VA. NOAA,WAVE PROPAGAT LAB,BOULDER,CO 80303. RP MINNIS, P (reprint author), NASA,LANGLEY RES CTR,DIV ATMOSPHER SCI,MAIL STOP 420,21 AMES RD,HAMPTON,VA 23665, USA. RI Minnis, Patrick/G-1902-2010 OI Minnis, Patrick/0000-0002-4733-6148 NR 22 TC 160 Z9 167 U1 0 U2 10 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 APR PY 1992 VL 31 IS 4 BP 317 EP 339 DI 10.1175/1520-0450(1992)031<0317:SCPDFS>2.0.CO;2 PG 23 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA HM313 UT WOS:A1992HM31300001 ER PT J AU MENZEL, WP WYLIE, DP STRABALA, KI AF MENZEL, WP WYLIE, DP STRABALA, KI TI SEASONAL AND DIURNAL CHANGES IN CIRRUS CLOUDS AS SEEN IN 4 YEARS OF OBSERVATIONS WITH THE VAS SO JOURNAL OF APPLIED METEOROLOGY LA English DT Article ID SOUNDER DATA; RETRIEVAL; RADIATION AB GOES VAS multispectral observations in the carbon dioxide absorption band at 15-mu-m have been used to compile cloud-cover statistics over the continential United States for the past 4 years. The CO2 technique calculates both cloud-top pressures and effective emissitivities and reliably distinguishes semitransparent cirrus from opaque clouds. The frequency of semitransparent cirrus clouds exhibits small seasonal variation; they are generally present 25%-30% of the time in all seasons. Diurnal variations of semitransparent cirrus are found only in the summer months and correspond to diurnal variations in convection in the Rocky Mountains and southeastern United States; increases of 20% in cirrus are noted subsequent to the convective cloud activity. In the winter months, no diurnal change in semitransparent cirrus is detected. Attempts to correlate cirrus with some common atmospheric features reveal that a majority of cirrus occurred where dynamic parameters indicate rising vertical motion but that considerable cirrus were also found where the dynamics was weak. Intercomparison with ground reports of cloud cover reveals that the satellite observations are corroborating or complementary 80% of the time; many of the diagreements come from the satellite identifying cold ground as low cloud or ground observations missing high thin clouds. C1 NOAA,NATL ENVIRONM SATELLITE DATA & INFORMAT SERV,ADV SATELLITE PROD PROJECT,MADISON,WI. RP MENZEL, WP (reprint author), UNIV WISCONSIN,CTR SPACE SCI & ENGN,COOPERAT INST METEOROL SATELLITE STUDIES,MADISON,WI 53706, USA. RI Menzel, W. Paul/B-8306-2011 OI Menzel, W. Paul/0000-0001-5690-1201 NR 21 TC 76 Z9 78 U1 0 U2 5 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 APR PY 1992 VL 31 IS 4 BP 370 EP 385 DI 10.1175/1520-0450(1992)031<0370:SADCIC>2.0.CO;2 PG 16 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA HM313 UT WOS:A1992HM31300004 ER PT J AU QUINN, PK ASHER, WE CHARLSON, RJ AF QUINN, PK ASHER, WE CHARLSON, RJ TI EQUILIBRIA OF THE MARINE MULTIPHASE AMMONIA SYSTEM SO JOURNAL OF ATMOSPHERIC CHEMISTRY LA English DT Article; Proceedings Paper CT 7TH INTERNATIONAL SYMP OF THE COMMISSION FOR ATMOSPHERIC CHEMISTRY AND GLOBAL POLLUTION : THE CHEMISTRY OF THE GLOBAL ATMOSPHERE CY SEP 05-11, 1990 CL CHAMROUSSE, FRANCE SP COMMISS ATMOSPHER CHEM & GLOBAL POLLUT, CNRS, INST NATL SCI UNIV, CNRS, PROGRAMME ENVIRONM, MINIST ENVIRONM, MINIST RECH & TECHNOL, UNIV JOSEPH FOURIER, MINIST AFFAIRES ETRANGERES, NOAA, NATL SCI FDN, NASA ID ATMOSPHERIC AEROSOLS; STRONG ELECTROLYTES; PACIFIC-OCEAN; SULFUR; SULFATE; MODEL AB A lack of empirical data has made it difficult to ascertain whether ammonia is in equilibrium between the oceanic, atmospheric gas and atmospheric particle phases in the remote marine environment. Reported here are simultaneous measurements of the saturation concentration of ammonia relative to ammonia concentrations in ocean surface waters, total seawater ammonia; atmospheric gas phase ammonia; and atmospheric particulate-phase ammonium, non-seasalt sulfate, methanesulfonate, and nitrate. Sampling was performed in May of 1987 in the northeast Pacific Ocean environment and in April and May of 1988 in the central Pacific Ocean environment. These measurements were used to determine the degree to which ammonia approached equilibrium between the oceanic and atmospheric gas and aerosol particle phases. The experimental atmospheric gas phase ammonia concentrations were compared with calculated equilibrium concentrations assuming a Henry's law type of partitioning between the gas and condensed phases. Characteristic times of the processes controlling the fate of ammonia in the marine environment also were compared. The measured atmospheric gas phase and oceanic concentrations of ammonia indicate that ammonia is not in a Henry's law equilibrium across the air/sea interface. This disequilibrium is a result of the long air/sea exchange equilibration time relative to the lifetime of ammonia in the atmosphere. Comparison of the calculated equilibrium gas phase ammonia concentrations with the measured gas phase ammonia concentrations shows that attainment of equilibrium between the atmospheric gas and particle phases is a strong function of the chemical composition of the aerosol particles. The data suggest that fully neutralized aerosol particles are not in Henry's law equilibrium with the gas phase while equilibrium is observed for particles with an average ammonium to non-seasalt sulfate molar ratio less than 1.8. C1 UNIV WASHINGTON,JOINT INST STUDY ATMOSPHERE & OCEAN,SEATTLE,WA 98195. UNIV WASHINGTON,DEPT ATMOSPHER SCI,SEATTLE,WA 98195. BATTELLE MEM INST,MARINE SCI LAB,SEQUIM,WA 98382. RP QUINN, PK (reprint author), NOAA,PACIFIC MARINE ENVIRONM LAB,SEATTLE,WA 98115, USA. RI Quinn, Patricia/R-1493-2016 OI Quinn, Patricia/0000-0003-0337-4895 NR 35 TC 43 Z9 44 U1 0 U2 4 PU KLUWER ACADEMIC PUBL PI DORDRECHT PA SPUIBOULEVARD 50, PO BOX 17, 3300 AA DORDRECHT, NETHERLANDS SN 0167-7764 J9 J ATMOS CHEM JI J. Atmos. Chem. PD APR PY 1992 VL 14 IS 1-4 BP 11 EP 30 DI 10.1007/BF00115219 PG 20 WC Environmental Sciences; Meteorology & Atmospheric Sciences SC Environmental Sciences & Ecology; Meteorology & Atmospheric Sciences GA HV102 UT WOS:A1992HV10200003 ER PT J AU CHAUMERLIAC, N ROSSET, R RENARD, M NICKERSON, EC AF CHAUMERLIAC, N ROSSET, R RENARD, M NICKERSON, EC TI THE TRANSPORT AND REDISTRIBUTION OF ATMOSPHERIC GASES IN REGIONS OF FRONTAL RAIN SO JOURNAL OF ATMOSPHERIC CHEMISTRY LA English DT Article; Proceedings Paper CT 7TH INTERNATIONAL SYMP OF THE COMMISSION FOR ATMOSPHERIC CHEMISTRY AND GLOBAL POLLUTION : THE CHEMISTRY OF THE GLOBAL ATMOSPHERE CY SEP 05-11, 1990 CL CHAMROUSSE, FRANCE SP COMMISS ATMOSPHER CHEM & GLOBAL POLLUT, CNRS, INST NATL SCI UNIV, CNRS, PROGRAMME ENVIRONM, MINIST ENVIRONM, MINIST RECH & TECHNOL, UNIV JOSEPH FOURIER, MINIST AFFAIRES ETRANGERES, NOAA, NATL SCI FDN, NASA DE TRACER VERTICAL EXCHANGES; CLOUD SCAVENGING; MESOSCALE MODELING ID NUMERICAL-SIMULATION; MODEL; CLOUDS AB Gases emitted in the planetary boundary layer can be transported very efficiently to the free troposphere through vertical motion along a frontal surface. A mesoscale numerical model was used to simulate the vertical transport of a tracer by clouds during frontogenesis in a moist atmosphere (an evolving Eady wave) in order to illustrate such vertical transport conditions. It is shown that the efficient vertical transport of a tracer occurs only when clouds are present, either when a surface or an in-situ source is considered. Insoluble, partially soluble, and soluble tracers are studied in order to determine the relative importance of vertical transport and scavenging on their redistribution. C1 NOAA,FORECAST SYST LAB,BOULDER,CO 80303. RP CHAUMERLIAC, N (reprint author), OBSERV PHYS GLOBE CLERMONT,LAMP,F-63000 CLERMONT FERRAND,FRANCE. NR 9 TC 12 Z9 12 U1 0 U2 0 PU KLUWER ACADEMIC PUBL PI DORDRECHT PA SPUIBOULEVARD 50, PO BOX 17, 3300 AA DORDRECHT, NETHERLANDS SN 0167-7764 J9 J ATMOS CHEM JI J. Atmos. Chem. PD APR PY 1992 VL 14 IS 1-4 BP 43 EP 51 DI 10.1007/BF00115221 PG 9 WC Environmental Sciences; Meteorology & Atmospheric Sciences SC Environmental Sciences & Ecology; Meteorology & Atmospheric Sciences GA HV102 UT WOS:A1992HV10200005 ER PT J AU PSZENNY, AAP AF PSZENNY, AAP TI PARTICLE-SIZE DISTRIBUTIONS OF METHANESULFONATE IN THE TROPICAL PACIFIC MARINE BOUNDARY-LAYER SO JOURNAL OF ATMOSPHERIC CHEMISTRY LA English DT Article; Proceedings Paper CT 7TH INTERNATIONAL SYMP OF THE COMMISSION FOR ATMOSPHERIC CHEMISTRY AND GLOBAL POLLUTION : THE CHEMISTRY OF THE GLOBAL ATMOSPHERE CY SEP 05-11, 1990 CL CHAMROUSSE, FRANCE SP COMMISS ATMOSPHER CHEM & GLOBAL POLLUT, CNRS, INST NATL SCI UNIV, CNRS, PROGRAMME ENVIRONM, MINIST ENVIRONM, MINIST RECH & TECHNOL, UNIV JOSEPH FOURIER, MINIST AFFAIRES ETRANGERES, NOAA, NATL SCI FDN, NASA DE METHANESULFONATE; PARTICLE SIZE DISTRIBUTION; FIELD MEASUREMENT ID SEA-SALT SULFATE; SULFUR CYCLE; ATMOSPHERIC SULFUR; AMERICAN SAMOA; FILTER PAPERS; CAPE GRIM; AEROSOL; ACID; DEPOSITION; MECHANISMS AB Fourteen high-volume cascade impactor samples were collected during a January-February. 1990, research cruise in the tropical Pacific from Panama to 180-degrees. Aqueous extracts of the samples were analyzed for methanesulfonate (MSA), sulfate, and the seasalt tracer ion magnesium. The majority of MSA size distributions showed no pronounced maximum on submicrometer particles, as has been observed elsewhere. Analysis of the data indicated that MSA was distributed essentially uniformly with the effective surface area of particles > 0.5-mu-m in radius, which were primarily seasalt. Relatively less MSA was found in smaller particles which were primarily sulfate. These results are consistent with those from theoretical and laboratory experimental studies reported in the literature which suggest that MSA produced from photochemical oxidation of dimethylsulfide condenses on pre-existing particles in strong preference to nucleating into new particles. This implies that MSA may not contribute appreciably to enhancing cloud condensation nucleus populations in the remote tropical marine atmosphere. RP PSZENNY, AAP (reprint author), NOAA,ATLANTIC OCEANOG & METEOROL LAB,DIV OCEAN CHEM,4301 RICKENBACKER CAUSEWAY,MIAMI,FL 33149, USA. NR 49 TC 40 Z9 40 U1 0 U2 3 PU KLUWER ACADEMIC PUBL PI DORDRECHT PA SPUIBOULEVARD 50, PO BOX 17, 3300 AA DORDRECHT, NETHERLANDS SN 0167-7764 J9 J ATMOS CHEM JI J. Atmos. Chem. PD APR PY 1992 VL 14 IS 1-4 BP 273 EP 284 DI 10.1007/BF00115239 PG 12 WC Environmental Sciences; Meteorology & Atmospheric Sciences SC Environmental Sciences & Ecology; Meteorology & Atmospheric Sciences GA HV102 UT WOS:A1992HV10200023 ER PT J AU BATES, TS LAMB, BK GUENTHER, A DIGNON, J STOIBER, RE AF BATES, TS LAMB, BK GUENTHER, A DIGNON, J STOIBER, RE TI SULFUR EMISSIONS TO THE ATMOSPHERE FROM NATURAL SOURCES SO JOURNAL OF ATMOSPHERIC CHEMISTRY LA English DT Article; Proceedings Paper CT 7TH INTERNATIONAL SYMP OF THE COMMISSION FOR ATMOSPHERIC CHEMISTRY AND GLOBAL POLLUTION : THE CHEMISTRY OF THE GLOBAL ATMOSPHERE CY SEP 05-11, 1990 CL CHAMROUSSE, FRANCE SP COMMISS ATMOSPHER CHEM & GLOBAL POLLUT, CNRS, INST NATL SCI UNIV, CNRS, PROGRAMME ENVIRONM, MINIST ENVIRONM, MINIST RECH & TECHNOL, UNIV JOSEPH FOURIER, MINIST AFFAIRES ETRANGERES, NOAA, NATL SCI FDN, NASA ID CARBONYL SULFIDE OCS; DYNAMIC ENCLOSURE METHODS; BIOGENIC SULFUR; DIMETHYL SULFIDE; PACIFIC-OCEAN; SEA-SALT; SURFACE WATERS; MARINE ATMOSPHERE; GLOBAL EMISSIONS; HYDROGEN-SULFIDE AB Emissions of sulfur gases from both natural and anthropogenic sources strongly influence the chemistry of the atmosphere. To assess the relative importance of these sources we have combined the measurements of sulfur gases and fluxes during the past decade to create a global emission inventory. The inventory, which is divided into 12 latitude belts, takes into account the seasonal dependence of sulfur emissions from biogenic sources. The total emissions of sulfur gases from natural sources are approximately 0.79 Tmol S/a. These emissions are 16% of the total sulfur emissions in the Northern Hemisphere and 58% in the Southern Hemisphere. The inventory clearly shows the impact of anthropogenic sulfur emissions in the region between 35-degrees and 50-degrees-N. C1 WASHINGTON STATE UNIV,ATMOSPHER RES LAB,PULLMAN,WA 99164. UNIV COLORADO,COOPERAT INST RES ENVIRONM,BOULDER,CO 80303. LAWRENCE LIVERMORE NATL LAB,LIVERMORE,CA 94550. DARTMOUTH COLL,DEPT EARTH SCI,HANOVER,NH 03755. RP BATES, TS (reprint author), NOAA,PACIFIC MARINE ENVIRONM LAB,SEATTLE,WA 98115, USA. RI Guenther, Alex/B-1617-2008; Bates, Timothy/L-6080-2016 OI Guenther, Alex/0000-0001-6283-8288; NR 135 TC 481 Z9 499 U1 3 U2 60 PU KLUWER ACADEMIC PUBL PI DORDRECHT PA SPUIBOULEVARD 50, PO BOX 17, 3300 AA DORDRECHT, NETHERLANDS SN 0167-7764 J9 J ATMOS CHEM JI J. Atmos. Chem. PD APR PY 1992 VL 14 IS 1-4 BP 315 EP 337 DI 10.1007/BF00115242 PG 23 WC Environmental Sciences; Meteorology & Atmospheric Sciences SC Environmental Sciences & Ecology; Meteorology & Atmospheric Sciences GA HV102 UT WOS:A1992HV10200026 ER PT J AU SNYDER, SM COLE, KD SZLAG, DC AF SNYDER, SM COLE, KD SZLAG, DC TI PHASE COMPOSITIONS, VISCOSITIES, AND DENSITIES FOR AQUEOUS 2-PHASE SYSTEMS COMPOSED OF POLYETHYLENE-GLYCOL AND VARIOUS SALTS AT 25-DEGREES-C SO JOURNAL OF CHEMICAL AND ENGINEERING DATA LA English DT Article AB Phase diagrams of aqueous two-phase systems composed of polyethylene glycol and various salt solutions were measured. The densities and viscosities of these phase systems were also measured. Polyethylene glycol was used with three average molecular masses of 1000, 3350, and 8000. The salts used were magnesium sulfate, sodium sulfate, sodium carbonate, ammonium sulfate, and potassium phosphate. Phase diagram data, as well as the densities and viscosities of the phases, were measured at 25-degrees-C. C1 NATL INST STAND & TECHNOL,325 BROADWAY,BOULDER,CO 80303. NR 9 TC 105 Z9 107 U1 4 U2 18 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 SN 0021-9568 J9 J CHEM ENG DATA JI J. Chem. Eng. Data PD APR PY 1992 VL 37 IS 2 BP 268 EP 274 DI 10.1021/je00006a036 PG 7 WC Thermodynamics; Chemistry, Multidisciplinary; Engineering, Chemical SC Thermodynamics; Chemistry; Engineering GA HP085 UT WOS:A1992HP08500036 ER PT J AU CLEMENT, SG ASHFOLD, MNR WESTERN, CM JOHNSON, RD HUDGENS, JW AF CLEMENT, SG ASHFOLD, MNR WESTERN, CM JOHNSON, RD HUDGENS, JW TI TRIPLET EXCITED-STATES OF THE NH(ND) RADICAL REVEALED VIA 2 PHOTON RESONANT MULTIPHOTON IONIZATION SPECTROSCOPY SO JOURNAL OF CHEMICAL PHYSICS LA English DT Note ID FOURIER-TRANSFORM SPECTROSCOPY; NH; ND; TRANSITION; 3-PI C1 NATL INST STAND & TECHNOL,CHEM SCI & TECHNOL LAB,DIV CHEM KINET & THERMODYNAM,GAITHERSBURG,MD 20899. RP CLEMENT, SG (reprint author), UNIV BRISTOL,SCH CHEM,BRISTOL BS8 1TS,AVON,ENGLAND. OI Western, Colin/0000-0002-8336-1690; ashfold, michael/0000-0001-5762-7048 NR 19 TC 10 Z9 10 U1 1 U2 4 PU AMER INST PHYSICS PI WOODBURY PA CIRCULATION FULFILLMENT DIV, 500 SUNNYSIDE BLVD, WOODBURY, NY 11797-2999 SN 0021-9606 J9 J CHEM PHYS JI J. Chem. Phys. PD APR 1 PY 1992 VL 96 IS 7 BP 5538 EP 5540 DI 10.1063/1.462691 PG 3 WC Chemistry, Physical; Physics, Atomic, Molecular & Chemical SC Chemistry; Physics GA HL099 UT WOS:A1992HL09900074 ER PT J AU KUSHNIR, Y LAU, NC AF KUSHNIR, Y LAU, NC TI THE GENERAL-CIRCULATION MODEL RESPONSE TO A NORTH PACIFIC SST ANOMALY - DEPENDENCE ON TIME SCALE AND PATTERN POLARITY SO JOURNAL OF CLIMATE LA English DT Article ID SEA-SURFACE TEMPERATURE; STEADY LINEAR RESPONSE; FLUCTUATIONS; ATLANTIC; CLIMATE; WAVES AB A general circulation model was integrated with perpetual January conditions and prescribed sea surface temperature (SST) anomalies in the North Pacific. A characteristic pattern with a warm region centered northeast of Hawaii and a cold region along the western seaboard of North America was alternately added to and subtracted from the climatological SST field. Long 1350-day runs, as well as short 180-day runs, each starting from different initial conditions, were performed. The results were compared to a control integration with climatological SSTs. The model's quasi-stationary response does not exhibit a simple linear relationship with the polarity of the prescribed SST anomaly. In the short runs with a negative SST anomaly over the central ocean, a large negative height anomaly, with an equivalent barotropic vertical structure, occurs over the Gulf of Alaska. For the same SST forcing, the long run yields a different response pattern in which an anomalous high prevails over northern Canada and the Alaskan Peninsula. A significant reduction in the northward heat flux associated with baroclinic eddies and a concomitant reduction in convective heating occur along the model's Pacific storm track. In the runs with a positive SST anomaly over the central ocean, the average height response during the first 90-day period of the short runs is too weak to be significant. In the subsequent 90-day period and in the long run an equivalent barotropic low occurs downstream from the warm SST anomaly. All positive anomaly runs exhibit little change in baroclinic eddy activity or in the patterns of latent heat release. Horizontal momentum transports by baroclinic eddies appear to help sustain the quasi-stationary response in the height field regardless of the polarity of the SST anomaly. These results emphasize the important role played by baroclinic eddies in determining the quasi-stationary response to midlatitude SST anomalies. Differences between the response patterns of the short and long integrations may be relevant to future experimental design for studying air-sea interactions in the extratropics. C1 PRINCETON UNIV,ATMOSPHER & OCEAN SCI PROGRAM,PRINCETON,NJ 08544. PRINCETON UNIV,NOAA,GEOPHYS FLUID DYNAM LAB,PRINCETON,NJ 08544. RI Kushnir, Yochanan/B-4472-2013 NR 30 TC 90 Z9 97 U1 2 U2 5 PU AMER METEOROLOGICAL SOC PI BOSTON PA 45 BEACON ST, BOSTON, MA 02108-3693 SN 0894-8755 J9 J CLIMATE JI J. Clim. PD APR PY 1992 VL 5 IS 4 BP 271 EP 283 DI 10.1175/1520-0442(1992)005<0271:TGCMRT>2.0.CO;2 PG 13 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA HQ341 UT WOS:A1992HQ34100001 ER PT J AU LAU, NC PHILANDER, SGH NATH, MJ AF LAU, NC PHILANDER, SGH NATH, MJ TI SIMULATION OF ENSO-LIKE PHENOMENA WITH A LOW-RESOLUTION COUPLED GCM OF THE GLOBAL OCEAN AND ATMOSPHERE SO JOURNAL OF CLIMATE LA English DT Article ID NINO SOUTHERN OSCILLATION; GENERAL-CIRCULATION MODEL; EL-NINO; PACIFIC-OCEAN; WORLD OCEAN; PRECIPITATION; 30-DEGREES-S; VARIABILITY AB A 140-year simulation of the ocean-atmosphere climate system has been performed by the GFDL Climate Dynamics Project using a low-resolution coupled general circulation model (GCM). The model was subjected to annually averaged insolation throughout the integration. This coupled system exhibits well-defined fluctuations in the tropical Pacific, with a preferred time scale of 3-4 years. The characteristics of these recurrent anomalies were examined by applying an extended empirical orthogonal function (EEOF) analysis to selected model variables. These results indicate that the simulated oscillations are accompanied by coherent changes in the atmospheric and oceanic circulation. The spatial patterns associated with the leading EEOF mode indicate that SST anomalies make their first appearance off the Peru-Ecuador coast and then migrate steadily westward, with an average transit time of 12-15 months. The arrival and eventual decay of SST fluctuations in the western Pacific is typically followed by the initiation of anomalies of the opposite polarity along the American coasts. The space-time evolution of various meteorological and oceanographic signals exhibits well-defined phase relationships with the SST perturbations. Some aspects of the model behavior during these warm and cold episodes are reminiscent of observed phenomena associated with the El Nino-Southern Oscillation (ENSO). Analysis of the climatological heat budget for the top ocean layer indicates a near balance between horizontal and vertical temperature advection by the time-mean flow, vertical diffusion, and heat input from the overlying atmosphere. Contributions of transient effects to this balance are negligible. The principal mechanisms associated with the simulated ENSO-like cycles were then studied by examining the local heat budget for the SST perturbations. It is shown that the relative importance of various linear advective processes in the heat budget exhibits a notable dependence on geographical location and on the specific phase of the ENSO-like cycle. RP LAU, NC (reprint author), PRINCETON UNIV,NOAA,GEOPHYS FLUID DYNAM LAB,FORRESTAL CAMPUS,US ROUTE 1,POB 308,PRINCETON,NJ 08542, USA. NR 39 TC 96 Z9 96 U1 0 U2 2 PU AMER METEOROLOGICAL SOC PI BOSTON PA 45 BEACON ST, BOSTON, MA 02108-3693 SN 0894-8755 J9 J CLIMATE JI J. Clim. PD APR PY 1992 VL 5 IS 4 BP 284 EP 307 DI 10.1175/1520-0442(1992)005<0284:SOELPW>2.0.CO;2 PG 24 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA HQ341 UT WOS:A1992HQ34100002 ER PT J AU PHILANDER, SGH PACANOWSKI, RC LAU, NC NATH, MJ AF PHILANDER, SGH PACANOWSKI, RC LAU, NC NATH, MJ TI SIMULATION OF ENSO WITH A GLOBAL ATMOSPHERIC GCM COUPLED TO A HIGH-RESOLUTION, TROPICAL PACIFIC-OCEAN GCM SO JOURNAL OF CLIMATE LA English DT Article ID SOUTHERN OSCILLATION; SEASONAL CYCLE; EL-NINO; MODEL AB A global atmospheric general circulation model (GCM) coupled to an oceanic GCM that is dynamically active only in the tropical Pacific simulates variability over a broad spectrum of frequencies even though the forcing, the annual mean incoming solar radiation, is steady. Of special interest is the simulation of a realistically irregular Southern Oscillation between warm El Nino and cold La Nina states. Its time scale is on the order of 5 years. The spatial structure is strikingly different in the eastern and western halves of the ocean basin. Sea surface temperature changes have their largest amplitude in the central and eastern tropical Pacific, but the low-frequency zonal wind fluctuations are displaced westward and are large over the western half of the basin. These zonal wind anomalies are essentially confined to the band of latitudes 10-degrees-N to 10-degrees-S so that they form a jet and have considerable latitudinal shear. During El Nino the associated curl contributes to a pair of pronounced minima in thermocline depth, symmetrically about the equator in the west, near 8-degrees-N and 8-degrees-S. In the east, where the low-frequency wind forcing is at a minimum, the deepening of the thermocline in response to the winds in the west has a very different shape-an approximate Gaussian shape centered on the equator. The low-frequency sea surface temperature and zonal wind anomalies wax and wane practically in place and in phase without significant zonal phase propagation. Thermocline depth variations have phase propagation; it is eastward at a speed near 15 cm s-1 along the equator in the western half of the basin and is westward off the equator. This phase propagation, a property of the oceanic response to the quasi-periodic winds that force currents and excite a host of waves with periods near 5 years, indicates that the ocean is not in equilibrium with the forcing. In other words, the ocean-atmosphere interactions that cause El Nino to develop at a certain time are countered and, in due course, reversed by the delayed response of the ocean to earlier winds. This "delayed oscillator" mechanism that sustains interannual oscillations in the model differs in its details from that previously discussed by Schopf and Suarez and others. The latter investigators invoke an explicit role for Kelvin and Rossby waves. These waves cannot be identified in the low-frequency fluctuations of this model, but they are energetic at relatively short periods and are of vital importance to a quasi-resonant oceanic mode with a period near 7 months that is excited in the model. The similarities and differences between the results of this simulation and those with other models, especially the one described in a companion paper, are discussed. C1 PRINCETON UNIV,NOAA,GEOPHYS FLUID DYNAM LAB,FORRESTAL CAMPUS,US ROUTE 1,POB 308,PRINCETON,NJ 08542. NR 24 TC 115 Z9 117 U1 0 U2 2 PU AMER METEOROLOGICAL SOC PI BOSTON PA 45 BEACON ST, BOSTON, MA 02108-3693 SN 0894-8755 J9 J CLIMATE JI J. Clim. PD APR PY 1992 VL 5 IS 4 BP 308 EP 329 DI 10.1175/1520-0442(1992)005<0308:SOEWAG>2.0.CO;2 PG 22 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA HQ341 UT WOS:A1992HQ34100003 ER PT J AU PORTMAN, DA WANG, WC KARL, TR AF PORTMAN, DA WANG, WC KARL, TR TI COMPARISON OF GENERAL-CIRCULATION MODEL AND OBSERVED REGIONAL CLIMATES - DAILY AND SEASONAL VARIABILITY SO JOURNAL OF CLIMATE LA English DT Article ID MONTHLY PRECIPITATION; SIMULATED CLIMATE; UNITED-STATES; SPECIFICATION; CO2; TEMPERATURE; EUROPE AB Validation of general circulation model (GCM) current climate simulations is important for further GCM development and application to climate change studies. So far, studies that compare GCM output with observations have focused primarily on large-scale spatial averages of the surface climate variables. Here we discuss two approaches to compare output of individual GCM grid boxes with local station observations near the surface and in the free troposphere. The first approach, proposed by Chervin, involves the application of standard parametric statistical analysis and hypothesis testing procedures. The second approach is nonparametric in the sense that no ideal distributions are postulated a priori to ascertain significance of the difference of mean temperature or the ratio of the temperature variance between model grid boxes and local stations. Instead, station observations are first subjected to a bootstrap technique and then used to define a unique set of distributions and confidence limits for each GCM grid box. To demonstrate the usefulness of the two approaches, we compare daily and seasonal gridbox temperatures simulated by the National Center for Atmospheric Research (NCAR) Community Climate Model (CCM1) with station temperatures at the surface, 850-mb, 500-mb, and 300-mb levels for three different areas in the United States. We find that although CCM1 gridbox temperatures are mostly cooler than station temperatures, they are equally variable. For all grid boxes, gridbox-to-station differences decrease with height and vary with time of year. We conclude that the techniques presented here can provide useful comparisons of GCM regional and local observed temperatures. Application to other variables and GCMs is also discussed. C1 SUNY ALBANY,ATMOSPHER SCI RES CTR,ALBANY,NY 12222. NATL CLIMAT CTR,NOAA,NATL ENVIRONM SATELLITE DATA & INFORMAT SERV,ASHEVILLE,NC. RP PORTMAN, DA (reprint author), ATMOSPHER & ENVIRONM RES INC,840 MEM DR,CAMBRIDGE,MA 02139, USA. NR 34 TC 25 Z9 25 U1 0 U2 3 PU AMER METEOROLOGICAL SOC PI BOSTON PA 45 BEACON ST, BOSTON, MA 02108-3693 SN 0894-8755 J9 J CLIMATE JI J. Clim. PD APR PY 1992 VL 5 IS 4 BP 343 EP 353 DI 10.1175/1520-0442(1992)005<0343:COGCMA>2.0.CO;2 PG 11 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA HQ341 UT WOS:A1992HQ34100005 ER PT J AU CHELLIAH, M ARKIN, P AF CHELLIAH, M ARKIN, P TI LARGE-SCALE INTERANNUAL VARIABILITY OF MONTHLY OUTGOING LONGWAVE RADIATION ANOMALIES OVER THE GLOBAL TROPICS SO JOURNAL OF CLIMATE LA English DT Article ID SEA-SURFACE-TEMPERATURE; EL-NINO; SOUTHERN OSCILLATION; CIRCULATION; PATTERNS; RADIANCE; SUMMER; TRENDS AB The objective of this study is to examine the broad aspects of large-scale interannual and long-term variability in the monthly mean outgoing longwave radiation (OLR) data over the global tropics. These data, derived from NOAA's polar-orbiting satellites, cover a period of more than 15 years. Rotated principal component analysis (RPCA) has been performed on monthly OLR anomalies over the global tropics (30-degrees-N-30-degrees-S) on a 10-degrees longitude by 5-degrees latitude grid for the period from June 1974 through March 1989, excluding calendar year 1978. The leading rotated principal components to be discussed below have been tested for robustness and reproducibility. The spatial-loading pattern and the time series for the first principal component (termed the "cononical ENSO" mode) represent the major large-scale features in the tropics during the typical phase of the major warm and cold events in the tropical Pacific during the analysis period. The characteristics of the dramatic 1982/83 warm event that were different from the canonical ENSO mode completely dominate the second RPC (termed the 1982/83 mode). The third and fourth leading RPCs appear to describe the changes in the satellite-observing system. Specifically, the third RPC is clearly associated with the different equator crossing times of the various NOAA satellites, while the fourth eigenmode may be related to the three major changes in the spectral windows of the different NOAA satellites. Of the six leading modes considered, the "nonphysical" modes (3 and 4) accounted for more than 40% of the explained variance over North Africa and northeastern South America. The physical modes (1, 2, 5, and 6) explained more than 70% of the variance in the central equatorial and eastern Pacific Ocean. It is demonstrated that while the eigenmodes that resul from unrotated principal component analysis are sensitive to small changes in analysis domain and period, those of the rotated analysis are fairly stable. However, note that the "1982/83 mode," as the name implies, is unique to the analysis period (1974-89). The results of the sensitivity analysis do not provide strong support of the claim by other authors that the decade of the 1980s, as compared to the 1970s, experienced enhanced levels of convective activity in the tropical Pacific and Indian oceans. C1 RES & DATA SYST CORP,GREENBELT,MD. NOAA,OFF CLIMATE & ATMOSPHER RES,ROCKVILLE,MD 20852. RP CHELLIAH, M (reprint author), NOAA,NATL WEATHER SERV,NATL METEOROL CTR,CTR CLIMATE ANAL,5200 AUTH RD,WASHINGTON,DC 20233, USA. RI Arkin, Phillip/F-5808-2010 NR 37 TC 84 Z9 86 U1 0 U2 4 PU AMER METEOROLOGICAL SOC PI BOSTON PA 45 BEACON ST, BOSTON, MA 02108-3693 SN 0894-8755 J9 J CLIMATE JI J. Clim. PD APR PY 1992 VL 5 IS 4 BP 371 EP 389 DI 10.1175/1520-0442(1992)005<0371:LSIVOM>2.0.CO;2 PG 19 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA HQ341 UT WOS:A1992HQ34100007 ER PT J AU ANDREWS, JB SCHMALE, AL SANDLIN, AC AF ANDREWS, JB SCHMALE, AL SANDLIN, AC TI THE INFLUENCE OF GRAVITY LEVEL DURING DIRECTIONAL SOLIDIFICATION OF IMMISCIBLE ALLOYS SO JOURNAL OF CRYSTAL GROWTH LA English DT Article; Proceedings Paper CT 1ST INTERNATIONAL WORKSHOP ON MATERIAL PROCESSING IN HIGH GRAVITY CY MAY 20-25, 1991 CL DUBNA, USSR SP USSR ACAD SCI, USSR SPACE RES INST, USSR JOINT INT RES CTR, FRENCH MINIST RES TECHNOL, FRENCH CTR NATL RECH SCI MEUDON, USA, RES OFF, EUROPEAN MAT RES SOC ID MONOTECTIC ALLOYS; SOLUTAL CONVECTION; BINARY ALLOY AB During directional solidification of immiscible (hypermonotectic) alloys it is theoretically possible to establish a stable macroscopically-planar solidification front, and thus avoid sedimentation. Unfortunately, convective instabilities often occur which interfere with the directional solidification process. In this paper, stability conditions are discussed and results presented from directional solidification studies carried out aboard NASA's KC-135 zero-g aircraft. Samples were directionally solidified while the effective gravity level was varied from approximately 0.01 g for 25 s to 1.8 g for 45 s. Dramatic variations in microstructure were observed with gravity level during solidification. C1 NATL INST STAND & TECHNOL,DIV MET,GAITHERSBURG,MD 20899. RP ANDREWS, JB (reprint author), UNIV ALABAMA,BIRMINGHAM,AL 35294, USA. NR 32 TC 9 Z9 9 U1 0 U2 5 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0022-0248 J9 J CRYST GROWTH JI J. Cryst. Growth PD APR PY 1992 VL 119 IS 1-2 BP 152 EP 159 DI 10.1016/0022-0248(92)90214-4 PG 8 WC Crystallography; Materials Science, Multidisciplinary; Physics, Applied SC Crystallography; Materials Science; Physics GA HQ520 UT WOS:A1992HQ52000017 ER PT J AU KLEBANOFF, PS CLEVELAND, WG TIDSTROM, KD AF KLEBANOFF, PS CLEVELAND, WG TIDSTROM, KD TI ON THE EVOLUTION OF A TURBULENT BOUNDARY-LAYER INDUCED BY A 3-DIMENSIONAL ROUGHNESS ELEMENT SO JOURNAL OF FLUID MECHANICS LA English DT Review ID VORTEX RINGS; REYNOLDS-NUMBER; ENTRAINMENT; TRANSITION; STABILITY; FLOW; VELOCITY; MOTION; PLANE; WAVES AB An experimental investigation is described which has as its objectives the extension of the technical data base pertaining to roughness-induced transition and the advancement of the understanding of the physical processes by which three-dimensional roughness elements induce transition from laminar to turbulent flow in boundary layers. The investigation was carried out primarily with single hemispherical roughness elements surface mounted in a well-characterized zero-pressure-gradient laminar boundary layer on a flat plate. The critical roughness Reynolds number at which turbulence is regarded as originating at the roughness was determined for the roughness elements herein considered and evaluated in the context of data existing in the literature. The effect of a steady and oscillatory free-stream velocity on eddy shedding was also investigated. The Strouhal behaviour of the 'hairpin' eddies shed by the roughness and role they play in the evolution of a fully developed turbulent boundary layer, as well as whether their generation is governed by an inflexional instability, are examined. Distributions of mean velocity and intensity of the u-fluctuation demonstrating the evolution toward such distributions for a fully developed turbulent boundary layer were measured on the centreline at Reynolds numbers below and above the critical Reynolds number of transition, A two-region model is postulated for the evolutionary change toward a fully developed turbulent boundary layer: an inner region where the turbulence is generated by the complex interaction of the hairpin eddies with the pre-existing stationary vortices that lie near the surface and are inherent to a flow about a three-dimensional obstacle in a laminar boundary layer; and an outer region where the hairpin eddies deform and generate turbulent vortex rings. The structure of the resulting fully developed turbulent boundary layer is discussed in the light of the proposed model for the evolutionary RP KLEBANOFF, PS (reprint author), NATL INST STAND & TECHNOL,GAITHERSBURG,MD 20899, USA. NR 109 TC 54 Z9 54 U1 2 U2 6 PU CAMBRIDGE UNIV PRESS PI NEW YORK PA 40 WEST 20TH STREET, NEW YORK, NY 10011-4211 SN 0022-1120 J9 J FLUID MECH JI J. Fluid Mech. PD APR PY 1992 VL 237 BP 101 EP 187 DI 10.1017/S0022112092003379 PG 87 WC Mechanics; Physics, Fluids & Plasmas SC Mechanics; Physics GA HT262 UT WOS:A1992HT26200007 ER PT J AU FOLDEAKI, M LEDBETTER, H UGGOWITZER, P AF FOLDEAKI, M LEDBETTER, H UGGOWITZER, P TI MAGNETIC-PROPERTIES OF CR-MN AUSTENITIC STAINLESS-STEELS SO JOURNAL OF MAGNETISM AND MAGNETIC MATERIALS LA English DT Article AB The magnetic susceptibility chi of three Cr-Mn austenitic stainless steels was measured as a function of temperature in the range 5-400 K. All specimens showed a characteristic susceptibility maximum. The temperature of the maximum and especially the curve shape depend strongly on specimen composition and metallurgical conditions (as-quenched, deformed). Because no significant field dependence appeared, the susceptibility maximum was identified as the antiferromagnetic Neel temperature. Chi(T) measurements above T(N) were fitted to a modified Curie-Weiss equation. Comparison between measurements and generalized-molecular-field-theory predictions allowed us to identify the magnetic structure as that of a first-type antiferromagnet with fcc crystal structure. The atomic magnetic moment and the molecular-field coefficients depend strongly not only on composition, but also on metallurgical prehistory, that is, on the degree of the applied mechanical deformation and heat treatment. Mainly, manganese affected the antiferromagnetic interactions, while chromium affected the ferromagnetic. Mn and Fe contributed the most to the effective atomic moment. Measurements on mechanically deformed specimens show a structure sensitivity of the molecular-field constants. This could be interpreted consistently in terms of lattice-parameter changes. The apparent structure sensitivity of the effective atomic moment can be attributed to changes in matrix composition caused by precipitation. C1 SWISS FED INST TECHNOL,CH-8092 ZURICH,SWITZERLAND. RP FOLDEAKI, M (reprint author), NIST,MAT SCI & ENGN LAB,BOULDER,CO 80303, USA. RI Uggowitzer, Peter/H-3581-2012 OI Uggowitzer, Peter/0000-0002-9504-5652 NR 6 TC 3 Z9 3 U1 0 U2 5 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 APR PY 1992 VL 110 IS 1-2 BP 185 EP 196 DI 10.1016/0304-8853(92)90031-I PG 12 WC Materials Science, Multidisciplinary; Physics, Condensed Matter SC Materials Science; Physics GA HW832 UT WOS:A1992HW83200029 ER PT J AU TEWARY, VK THOMSON, R AF TEWARY, VK THOMSON, R TI LATTICE STATICS OF INTERFACES AND INTERFACIAL CRACKS IN BIMATERIAL SOLIDS SO JOURNAL OF MATERIALS RESEARCH LA English DT Article ID GREEN-FUNCTION METHOD; GRAIN-BOUNDARY INTERFACES; ATOMISTIC STRUCTURE AB A method for calculating lattice statics Green's function is described for a bimaterial lattice or a bicrystal containing a plane interface. The method involves creation of two half space lattices containing free surfaces and then joining them to form a bicrystal. The two half space lattices may have different structures as in a two-phase bicrystal or may be of the same type but joined at different orientations to form a grain boundary interface. The method is quite general but, in this paper, has been applied only to a simple model bicrystal formed by two simple cubic lattices with nearest neighbor interactions. The bimaterial Green's function is modified to account for an interfacial crack that is used to calculate the displacement field due to an applied external force. It is found that the displacement field, as calculated by using the lattice theory, does not have the unphysical oscillations predicted by the continuum theory. C1 NATL INST STAND & TECHNOL,MAT SCI & ENGN LAB,GAITHERSBURG,MD 20899. RP TEWARY, VK (reprint author), NATL INST STAND & TECHNOL,DIV MAT RELIABIL,BOULDER,CO 80303, USA. NR 17 TC 10 Z9 10 U1 0 U2 1 PU MATERIALS RESEARCH SOCIETY PI PITTSBURGH PA 9800 MC KNIGHT ROAD SUITE 327, PITTSBURGH, PA 15237 SN 0884-2914 J9 J MATER RES JI J. Mater. Res. PD APR PY 1992 VL 7 IS 4 BP 1018 EP 1028 DI 10.1557/JMR.1992.1018 PG 11 WC Materials Science, Multidisciplinary SC Materials Science GA HP370 UT WOS:A1992HP37000035 ER PT J AU FRASER, GT DOMENECH, J JUNTTILA, ML PINE, AS AF FRASER, GT DOMENECH, J JUNTTILA, ML PINE, AS TI MOLECULAR-BEAM OPTOTHERMAL SPECTRUM OF THE NU-1 C-H STRETCHING FUNDAMENTAL-BAND OF CHF2CL SO JOURNAL OF MOLECULAR SPECTROSCOPY LA English DT Article ID VIBRATIONAL-SPECTRUM; CF2HCL; CHCLF2; CHLORODIFLUOROMETHANE; DISSOCIATION; RESONANCES; DEPENDENCE; PHOTOLYSIS; SEPARATION; INTENSITY C1 HELSINKI UNIV TECHNOL,METROL RES INST,SF-02150 ESPOO 15,FINLAND. RP FRASER, GT (reprint author), NATL INST STAND & TECHNOL,DIV MOLEC PHYS,GAITHERSBURG,MD 20899, USA. RI Domenech, Jose/F-5561-2013 OI Domenech, Jose/0000-0001-8629-2566 NR 35 TC 15 Z9 15 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 APR PY 1992 VL 152 IS 2 BP 307 EP 316 DI 10.1016/0022-2852(92)90071-U PG 10 WC Physics, Atomic, Molecular & Chemical; Spectroscopy SC Physics; Spectroscopy GA HK082 UT WOS:A1992HK08200005 ER PT J AU DUNCAN, MW MARINI, AM WATTERS, R KOPIN, IJ MARKEY, SP AF DUNCAN, MW MARINI, AM WATTERS, R KOPIN, IJ MARKEY, SP TI ZINC, A NEUROTOXIN TO CULTURED NEURONS, CONTAMINATES CYCAD FLOUR PREPARED BY TRADITIONAL GUAMANIAN METHODS SO JOURNAL OF NEUROSCIENCE LA English DT Article ID AMYOTROPHIC LATERAL SCLEROSIS; MESENCEPHALIC DOPAMINERGIC-NEURONS; PARKINSONISM-DEMENTIA; UNLIKELY CAUSE; ACID BMAA; DISEASE; GUAM; CELLS; GLUTAMATE; RECEPTOR AB We have used cultured ventral mesencephalic and cerebellar granule cells to test the toxicity of extracts of cycad seeds (genus Cycas) and cycad-derived flours traditionally prepared in Guam. There was no significant difference in the toxicity of extracts prepared from the female gametophyte tissue of C. circinalis, C. revoluta, and C. media, common wheat flour, and 13 of 17 cycad flour samples. However, extracts prepared from 4 of 17 Guamanian flour samples exhibited marked dose-dependent neurotoxicity to mesencephalic and granule cell cultures. There was no correlation between toxicity and 2-amino-3-(methylamino)-propanoic acid (BMAA) content, and the concentration of BMAA in the medium arising from these extracts was far below that required to be neurotoxic. Toxicity of extracts was not blocked by the NMDA receptor antagonist MK-801 or the non-NMDA receptor antagonist 6-cyano-7-dinitroquinoxaline-2,3-dione, indicating that toxicity was not mediated by excitatory amino acid receptors. Analysis of the four toxic processed flour samples indicated high zinc content. Zinc produced a concentration-dependent neurotoxic response in mesencephalic and granule cell cultures that paralleled the calculated concentrations of zinc in the cultures derived from the four toxic flour samples. When sliced C. circinalis gametophyte tissue was "processed" in our laboratory by soaking in a galvanized container, there was a time-dependent increase in zinc content. C1 NINCDS,INTRAMURAL RES PROGRAM,BETHESDA,MD 20892. NATL INST STANDARDS & TECHNOL,GAITHERSBURG,MD 20899. NIMH,ANALYT BIOCHEM SECT,BETHESDA,MD 20892. NR 36 TC 59 Z9 59 U1 0 U2 3 PU SOC NEUROSCIENCE PI WASHINGTON PA 11 DUPONT CIRCLE, NW, STE 500, WASHINGTON, DC 20036 SN 0270-6474 J9 J NEUROSCI JI J. Neurosci. PD APR PY 1992 VL 12 IS 4 BP 1523 EP 1537 PG 15 WC Neurosciences SC Neurosciences & Neurology GA HM363 UT WOS:A1992HM36300030 PM 1556606 ER PT J AU FENG, DM KOCH, WF WU, YC AF FENG, DM KOCH, WF WU, YC TI INVESTIGATION OF THE INTERACTION OF HCL AND 3 AMINO-ACIDS, HEPES, MOPSO AND GLYCINE, BY EMF-MEASUREMENTS SO JOURNAL OF SOLUTION CHEMISTRY LA English DT Article DE ACTIVITY COEFFICIENT; AMINO ACID; EMF; 1ST DISSOCIATION CONSTANT; HEPES; GLYCINE; MOPSO; IONIC INTERACTION; HYDROCHLORIC ACID AB Ionic interaction in the three systems HCl-HEPES (N-2-hydroxyethyl-piperazine-N'-2-ethanesulfonic acid), HCl-MOPSO (3-(N-Morpholino)-2-hydroxypropanesulfonic acid), and HCl-glycine have been studied in terms of their mutual influence on the respective activity coefficients of each component. Activity coefficients for each component of the three systems are calculated from emf measurements of solutions containing HCl and the amino acid in a H-2/solution/AgCl,Ag cell at 25-degrees-C. The first dissociation constant of HEPES at 25-degrees-C has also been determined using emf and pH titration measurements. C1 NATL INST STAND & TECHNOL,DIV INORGAN ANALYT RES,GAITHERSBURG,MD 20899. NR 12 TC 1 Z9 1 U1 0 U2 1 PU PLENUM PUBL CORP PI NEW YORK PA 233 SPRING ST, NEW YORK, NY 10013 SN 0095-9782 J9 J SOLUTION CHEM JI J. Solut. Chem. PD APR PY 1992 VL 21 IS 4 BP 311 EP 321 DI 10.1007/BF00647854 PG 11 WC Chemistry, Physical SC Chemistry GA HM942 UT WOS:A1992HM94200001 ER PT J AU WU, YC KOCH, WF BEREZANSKY, PA HOLLAND, LA AF WU, YC KOCH, WF BEREZANSKY, PA HOLLAND, LA TI CONDUCTIVITY OF ELECTROLYTES AND THEIR MIXTURES - THE AQUEOUS HCL-MGCL2 SYSTEM AT LOW CONCENTRATIONS SO JOURNAL OF SOLUTION CHEMISTRY LA English DT Article DE ELECTROLYTIC CONDUCTANCE; HYDROCHLORIC ACID; IONIC MOBILITY; MAGNESIUM CHLORIDE; AND MIXTURE EFFECT ID CONDUCTANCE AB The Onsager-Fuoss-Chen theory of conductance for mixtures has been explored and compared with experimental results for the system HCl-MgCl2-H2O from 5 x 10(-5) to 0.02 mol-kg-1 of water. In the theory, the higher order term O(kappa-a) which involves the ion size parameter has been replaced by a linear term with an empirical constant. The theory including the additional linear term agrees well with the experimental results. The mixture effect on the equivalent conductance is small, but on the individual ionic mobilities is substantial. RP WU, YC (reprint author), NATL INST STAND & TECHNOL,DIV INORGAN ANALYT RES,GAITHERSBURG,MD 20899, USA. RI Holland, Lisa/C-2208-2011 NR 23 TC 3 Z9 3 U1 0 U2 4 PU PLENUM PUBL CORP PI NEW YORK PA 233 SPRING ST, NEW YORK, NY 10013 SN 0095-9782 J9 J SOLUTION CHEM JI J. Solut. Chem. PD APR PY 1992 VL 21 IS 4 BP 383 EP 396 DI 10.1007/BF00647861 PG 14 WC Chemistry, Physical SC Chemistry GA HM942 UT WOS:A1992HM94200008 ER PT J AU TEWARY, VK FORTUNKO, CM AF TEWARY, VK FORTUNKO, CM TI A COMPUTATIONALLY EFFICIENT REPRESENTATION FOR PROPAGATION OF ELASTIC-WAVES IN ANISOTROPIC SOLIDS SO JOURNAL OF THE ACOUSTICAL SOCIETY OF AMERICA LA English DT Article AB A new closed-form representation is developed for the exact solution of the Christoffel equation for wave propagation in solids. The new representation is numerically more efficient than the traditional representations based on the use of Fourier and Laplace transforms. Using the new representation, the retarded Green's functions are derived for an infinite anisotropic solid and an anisotropic half-space. The method is applied to calculate the elastic-wave response of an anisotropic cubic solid to highly localized delta function and step function type impulses. Both surface and bulk wave responses have been calculated. The effect of anisotropy is discussed by considering cubic solids with different anisotropy parameters. Interestingly, it is found that, for certain values of the anisotropy parameter, two distinct longitudinally polarized components can be observed to propagate along an axis of cubic symmetry. One of the signals is the normal longitudinal wave signal while the other results from the concave shape of the transverse slowness surface. RP TEWARY, VK (reprint author), NATL INST STAND & TECHNOL,DIV MAT RELIABIL,BOULDER,CO 80303, USA. NR 16 TC 28 Z9 28 U1 0 U2 6 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 APR PY 1992 VL 91 IS 4 BP 1888 EP 1896 DI 10.1121/1.403699 PN 1 PG 9 WC Acoustics; Audiology & Speech-Language Pathology SC Acoustics; Audiology & Speech-Language Pathology GA HP367 UT WOS:A1992HP36700009 ER PT J AU NILSSON, WB SEABORN, GT HUDSON, JK AF NILSSON, WB SEABORN, GT HUDSON, JK TI PARTITION-COEFFICIENTS FOR FATTY-ACID ESTERS IN SUPERCRITICAL FLUID CO2 WITH AND WITHOUT ETHANOL SO JOURNAL OF THE AMERICAN OIL CHEMISTS SOCIETY LA English DT Article DE COSOLVENT; ETHANOL; FATTY ACID ESTERS; FISH OIL; PARTITION COEFFICIENTS; SUPERCRITICAL FLUID CARBON DIOXIDE ID CARBON-DIOXIDE; METHYL-ESTERS; FRACTIONATION AB The complex nature of fish oils was exploited to study the dependence of structural factors upon fatty acid ester solubility in supercritical fluid carbon dioxide (SCF-CO2). Partition coefficients were determined for a number of components present in two mixtures of fatty acid ethyl esters derived from menhaden oil in SCF-CO2 at 60-degrees-C and 125 bar. Analogous data also were obtained for SCF-CO2 with 5% (w/w) ethanol added. The addition of ethanol was found to increase partition coefficients for all species, but resulted in a decrease of fluid selectivity. Aside from the chain length of a component, both the degree and position of unsaturation were found to be structural factors that affect the value of the partition coefficient. C1 NOAA,NATL MARINE FISHERIES SERV,DEPT COMMERCE,SE FISHERIES CTR,CHARLESTON LAB,CHARLESTON,SC 29422. RP NILSSON, WB (reprint author), NOAA,NATL MARINE FISHERIES SERV,DEPT COMMERCE,NW FISHERIES CTR,DIV UTILIZAT RES,SEATTLE,WA 98112, USA. NR 23 TC 30 Z9 35 U1 1 U2 2 PU AMER OIL CHEMISTS SOC PI CHAMPAIGN PA 1608 BROADMOOR DRIVE, CHAMPAIGN, IL 61821-0489 SN 0003-021X J9 J AM OIL CHEM SOC JI J. Am. Oil Chem. Soc. PD APR PY 1992 VL 69 IS 4 BP 305 EP 308 DI 10.1007/BF02636055 PG 4 WC Chemistry, Applied; Food Science & Technology SC Chemistry; Food Science & Technology GA HM913 UT WOS:A1992HM91300003 ER PT J AU KLINKER, E SARDESHMUKH, PD AF KLINKER, E SARDESHMUKH, PD TI THE DIAGNOSIS OF MECHANICAL DISSIPATION IN THE ATMOSPHERE FROM LARGE-SCALE BALANCE REQUIREMENTS SO JOURNAL OF THE ATMOSPHERIC SCIENCES LA English DT Article ID GRAVITY-WAVE DRAG; WEATHER PREDICTION MODELS; GENERAL-CIRCULATION; ENVELOPE OROGRAPHY; PARAMETRIZATION; ECMWF; DIVERGENCE; FORECASTS; SYSTEMS; IMPACT AB The momentum budget for January 1987 is evaluated with global observations analyzed at the European Centre for Medium-Range Weather Forecasts (ECMWF). The dissipation term is diagnosed from the budget as a balance requirement, that is, as that required to balance the sum of the advection, Coriolis, pressure gradient, and local tendency terms. This is then compared with the parameterized subgrid-scale effects in the ECMWF model's momentum equation, with a view of identifying possible errors in those parameterizations. The balance requirement does not support the high parameterized values of orographically induced gravity-wave drag in the lower stratosphere. A deeper analysis also does not suggest a major role for turbulent vertical transports above the boundary layer. On the other hand, our budget does indicate that more effort be spent on a better representation of the potential enstrophy cascade associated with Rossby wave breaking in the upper troposphere. These statements are qualified by the errors in the balance requirement itself. The extent to which this is a problem is discussed. A distinctive feature of these calculations is their internal consistency; that is, all the terms in the budget are evaluated as in the version of the ECMWF model used for assimilating the observations. This offers several advantages, not the least of which is that it makes our budget residuals identical to the systematic initial tendency errors of the operational weather forecasts, thus facilitating their computation and routine monitoring. As such, our calculations explain a large fraction of the systematic short-range forecast errors and, because of their local character, provide clues as to the possible sources of those errors. Experiments with and without gravity-wave drag are described to illustrate its large contribution during this period to the southerly wind error of the operational weather forecasts at 70 mb over western North America. C1 UNIV COLORADO,NOAA,COOPERAT INST RES ENVIRONM SCI,CAMPUS BOX 449,BOULDER,CO 80309. EUROPEAN CTR MEDIUM RANGE WEATHER FORECASTS,READING,BERKS,ENGLAND. NR 29 TC 101 Z9 105 U1 1 U2 6 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 1 PY 1992 VL 49 IS 7 BP 608 EP 627 DI 10.1175/1520-0469(1992)049<0608:TDOMDI>2.0.CO;2 PG 20 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA HQ272 UT WOS:A1992HQ27200004 ER PT J AU TSENG, W PELLEGRINO, J KIM, J THURBER, R COMAS, J PAPANICOLOU, N PROKES, S AF TSENG, W PELLEGRINO, J KIM, J THURBER, R COMAS, J PAPANICOLOU, N PROKES, S TI REDUCTION OF DX CENTERS IN SUPERLATTICE ALLOY-LIKE MATERIAL HIGH ELECTRON-MOBILITY TRANSISTORS SO JOURNAL OF THE ELECTROCHEMICAL SOCIETY LA English DT Article ID QUANTIZED HALL RESISTANCE; PERSISTENT PHOTOCONDUCTIVITY; DOPED ALXGA1-XAS; GAAS; SI; SILICON; LAYERS; MODEL; MBE AB The substitution of selectively Si-doped short-period (4 by 2 and 2 by 1 monolayer(s)) GaAs/AlAs superlattice alloy-like material (SLAM) for Si-doped AlGaAs layers in conventional high electron mobility transistor (HEMT) structures has been demonstrated. Such a short period SLAM HEMT still preserves its field effect transistor characteristics as compared with the conventional HEMT. The shifts of threshold voltages and amounts of DX centers were found to depend on the layer thickness of the superlattices and the positions of Si-dopants within the GaAs layers. C1 USN,RES LAB,WASHINGTON,DC 20375. RP TSENG, W (reprint author), NATL INST STAND & TECHNOL,GAITHERSBURG,MD 20899, USA. NR 16 TC 2 Z9 2 U1 0 U2 0 PU ELECTROCHEMICAL SOC INC PI PENNINGTON PA 10 SOUTH MAIN STREET, PENNINGTON, NJ 08534 SN 0013-4651 J9 J ELECTROCHEM SOC JI J. Electrochem. Soc. PD APR PY 1992 VL 139 IS 4 BP 1219 EP 1222 DI 10.1149/1.2069371 PG 4 WC Electrochemistry; Materials Science, Coatings & Films SC Electrochemistry; Materials Science GA HN522 UT WOS:A1992HN52200054 ER PT J AU WINTERS, MP OATES, CW HALL, JL DINSE, KP AF WINTERS, MP OATES, CW HALL, JL DINSE, KP TI HIGH-RESOLUTION OPTICAL MULTIPLEX SPECTROSCOPY SO JOURNAL OF THE OPTICAL SOCIETY OF AMERICA B-OPTICAL PHYSICS LA English DT Article ID FREQUENCY-MODULATION SPECTROSCOPY; FOURIER-TRANSFORM SPECTRA; DYE-LASER; LINEAR PREDICTION; SATURATION SPECTROSCOPY; STOCHASTIC EXCITATION; 2-PHOTON ABSORPTION; EXACT INTERPOLATION; RAMSEY FRINGES; NOISE AB We report on recent refinements in the development of high-resolution optical multiplex spectroscopy using stochastic excitation. We discuss the attainment of higher excitation bandwidths through the use of faster digital noise sources and digital filtering techniques, the active suppression of residual amplitude modulation noise, laser-frequency stabilization using an external stabilizer, and the performance of various data-analysis methods. C1 UNIV COLORADO,JOINT INST LAB ASTROPHYS,BOULDER,CO 80309. NATL INST STAND & TECHNOL,BOULDER,CO 80309. UNIV DORTMUND,W-4600 DORTMUND 50,GERMANY. NR 56 TC 1 Z9 1 U1 0 U2 3 PU OPTICAL SOC AMER PI WASHINGTON PA 2010 MASSACHUSETTS AVE NW, WASHINGTON, DC 20036 SN 0740-3224 J9 J OPT SOC AM B JI J. Opt. Soc. Am. B-Opt. Phys. PD APR PY 1992 VL 9 IS 4 BP 498 EP 506 DI 10.1364/JOSAB.9.000498 PG 9 WC Optics SC Optics GA HM686 UT WOS:A1992HM68600005 ER PT J AU STJOHN, WD TAHERI, B WICKSTED, JP POWELL, RC BLACKBURN, DH CRANMER, DC AF STJOHN, WD TAHERI, B WICKSTED, JP POWELL, RC BLACKBURN, DH CRANMER, DC TI TIME-DEPENDENT THERMAL LENSING IN LEAD-OXIDE MODIFIED SILICATE GLASS SO JOURNAL OF THE OPTICAL SOCIETY OF AMERICA B-OPTICAL PHYSICS LA English DT Article ID LASER; BEAMS AB The detection and characterization of the thermal-lensing effect is measured for a lead oxide-modified silicate glass material. The self-modulation of the exciting beam is measured with a simple experimental setup on both millisecond and nanosecond time scales. The results of our analysis indicate that to first order the operative mechanism of self-focusing is the same on both time scales, namely, the time-dependent modulation of the refractive index that is due to thermal heating. On a millisecond time scale we recognize the occurrence of multiple focal points within the sample. Although these undulations in the beam waist have been reported previously by others, our experimental methods allow these undulations to manifest themselves in new ways, namely, in Z scans and transmittance versus power profiles. These are indicative of a strong thermo-optic effect and are consequences of Maxwell's equations. With our model a dn/dT value of 1 x 10(-5) K-1 is extracted. C1 NATL INST STAND & TECHNOL,GAITHERSBURG,MD 20890. RP STJOHN, WD (reprint author), OKLAHOMA STATE UNIV,DEPT PHYS,CTR LASER RES,STILLWATER,OK 74078, USA. NR 27 TC 12 Z9 12 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 APR PY 1992 VL 9 IS 4 BP 610 EP 616 PG 7 WC Optics SC Optics GA HM686 UT WOS:A1992HM68600017 ER PT J AU DELONG, RL AF DELONG, RL TI DOCUMENTING MIGRATIONS OF NORTHERN ELEPHANT SEALS USING DAY LENGTH SO MARINE MAMMAL SCIENCE LA English DT Note C1 WORLD RES INST,HUBBS MARINE RES CTR,SAN DIEGO,CA 92109. WILDLIFE COMP,WOODINVILLE,WA 98072. RP DELONG, RL (reprint author), NOAA,NATL MARINE FISHERIES SERV,NATL MARINE MAMMAL LAB,7600 SAND PT WAY,SEATTLE,WA 98115, USA. NR 9 TC 76 Z9 78 U1 4 U2 16 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 APR PY 1992 VL 8 IS 2 BP 155 EP 159 DI 10.1111/j.1748-7692.1992.tb00375.x PG 5 WC Marine & Freshwater Biology; Zoology SC Marine & Freshwater Biology; Zoology GA HR283 UT WOS:A1992HR28300007 ER PT J AU MAJLUF, P GOEBEL, ME AF MAJLUF, P GOEBEL, ME TI THE CAPTURE AND HANDLING OF FEMALE SOUTH-AMERICAN FUR SEALS AND THEIR PUPS SO MARINE MAMMAL SCIENCE LA English DT Note C1 UNIV CAMBRIDGE,DEPT ZOOL,LARGE ANIM RES GRP,CAMBRIDGE CB3 0DT,ENGLAND. ALASKA FISHERIES SCI CTR,NATL MARINE MAMMAL LAB,SEATTLE,WA 98115. NR 3 TC 20 Z9 20 U1 0 U2 2 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 APR PY 1992 VL 8 IS 2 BP 187 EP 190 DI 10.1111/j.1748-7692.1992.tb00382.x PG 4 WC Marine & Freshwater Biology; Zoology SC Marine & Freshwater Biology; Zoology GA HR283 UT WOS:A1992HR28300014 ER PT J AU WILCZAK, JM CHRISTIAN, TW WOLFE, DE ZAMORA, RJ STANKOV, B AF WILCZAK, JM CHRISTIAN, TW WOLFE, DE ZAMORA, RJ STANKOV, B TI OBSERVATIONS OF A COLORADO TORNADO .1. MESOSCALE ENVIRONMENT AND TORNADOGENESIS SO MONTHLY WEATHER REVIEW LA English DT Article ID SEVERE STORM ENVIRONMENT; LIFE-CYCLE; BOUNDARY-LAYER; DENVER CYCLONE; THUNDERSTORM; WIND; WATERSPOUTS; INITIATION; DIAGNOSIS; ROTATION AB On 2 July 1987 a nonmesocyclone tornado was observed in northeastern Colorado during the Convection Initiation and Downburst Experiment (CINDE). This tornado, reaching F1-F2 intensity, developed under a rapidly growing convective cell, without a preceding supercell or midlevel mesocyclone being present. The pretornado environment on 2 July is described, including observations from a triangle of wind profilers, a dense surface mesonet array, and a special balloon sounding network. Important features contributing to tornado generation include the passage of a 700-mb short-wave trough; the formation of an approximately 70-km diameter, terrain-induced mesoscale vortex (the Denver Cyclone) and its associated baroclinic zone; the presence of a stationary low-level convergence boundary; and the presence of low-level azimuthal shear maxima (misovortices) along the boundary. Vorticity budget terms are calculated in the lowest 2 km AGL using a multiple-Doppler radar analysis. These terms and their spatial distributions are compared with observations of mesocyclone-associated supercell tornadoes. Results show that vorticity associated with the 2 July nonsupercell tornado was generated in a more complicated manner than that proposed by previous nonsupercell tornadogenesis theory. In particular, tilting of baroclinically generated streamwise horizontal vorticity into the vertical was important for the formation of low-level rotation, in a manner similar to that previously proposed for supercell tornadic storms. C1 UNIV COLORADO,NOAA,COOPERAT INST RES ENVIRONM SCI,BOULDER,CO 80309. RP WILCZAK, JM (reprint author), NOAA,ENVIRONM RESOURCES LAB,WAVE PROPAGAT LAB,325 BROADWAY,BOULDER,CO 80303, USA. NR 52 TC 13 Z9 13 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 APR PY 1992 VL 120 IS 4 BP 497 EP 521 DI 10.1175/1520-0493(1992)120<0497:OOACTP>2.0.CO;2 PG 25 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA HK879 UT WOS:A1992HK87900001 ER PT J AU WAKIMOTO, RM MARTNER, BE AF WAKIMOTO, RM MARTNER, BE TI OBSERVATIONS OF A COLORADO TORNADO .2. COMBINED PHOTOGRAMMETRIC AND DOPPLER RADAR ANALYSIS SO MONTHLY WEATHER REVIEW LA English DT Article ID SUPERCELL THUNDERSTORM; NUMERICAL-SIMULATION; VORTEX DYNAMICS; LIFE-CYCLE; VORTICES; OUTFLOW; FIELD; CORE AB An integrated analysis of photographic and Doppler radar observations of a tornadic storm during the Convection Initiation and Downburst Experiment (CINDE) is presented. High-resolution single-Doppler radar measurements are combined with cloud photogrammetry to reveal the detailed structural relationship of the hook echo and the misocyclone with visual features of the tornado. Vertical cross sections of dual-Doppler winds in the plane of the photographs were also examined to determine the complex motions within and surrounding the vortex. The tornado was found to be within a weak-echo hole of the hook echo. The hole progressed upward above cloud base as the tornado matured. An annulus of higher reflectivity that formed a hook echo is hypothesized to have been composed of sparse but large raindrops. The airflow fields suggest that vortex breakdown and axial downdrafts were present near the ground at early stages shortly after the tornado became visible. Later, axial upward flow dominated at all levels until the collapse of the vortex. C1 NOAA,ENVIRONM RESOURCES LAB,BOULDER,CO 80303. RP WAKIMOTO, RM (reprint author), UNIV CALIF LOS ANGELES,DEPT ATMOSPHER SCI,7127 MATH SCI BLDG,LOS ANGELES,CA 90024, USA. NR 63 TC 43 Z9 43 U1 1 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 APR PY 1992 VL 120 IS 4 BP 522 EP 543 DI 10.1175/1520-0493(1992)120<0522:OOACTP>2.0.CO;2 PG 22 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA HK879 UT WOS:A1992HK87900002 ER PT J AU CURRAN, EB RUST, WD AF CURRAN, EB RUST, WD TI POSITIVE GROUND FLASHES PRODUCED BY LOW-PRECIPITATION THUNDERSTORMS IN OKLAHOMA ON 26 APRIL 1984 SO MONTHLY WEATHER REVIEW LA English DT Article ID WINTER THUNDERSTORMS; STORMS; MODEL; EVOLUTION; DYNAMICS AB A group of thunderstorms developed in western Oklahoma during the afternoon of 26 April 1984. Two of these storms initially exhibited characteristics of low-precipitation (LP) thunderstorms. Lightning ground flashes produced by these storms were mostly positive. These storms split, with one right-moving component evolving into a tornadic supercell. Ground flashes produced by the supercell, however, were predominantly negative. The highest rate of positive ground flashes (1.5 min-1) occurred during LP storm splitting and merging, when about 84% of ground flashes were positive. The maximum total ground-strike rate was 3.4 min-1 and occurred during the tornadic supercell phase and when all but one of 136 ground flashes were negative. Analysis of lightning ground-strike and radar reflectivity data reveals a concentration of positive ground flashes in areas of maximum reflectivity within the LP storms; furthermore, the concentration of positive flashes appeared during storm split. After storm splitting and merging, the number of positive ground flashes in all cells decreased. Recent studies suggested a relationship between high values of wind-shear magnitude within the cloud-bearing layer and the production of positive ground flashes. Analyses of soundings in the environments of the LP and supercell thunderstorms on this day show that the magnitude of the vector-averaged shear vector within the cloud-bearing layer was 4.8 x 10(-3) and 3.8 x 10(-3) s-1, respectively. Both are above the previously published thresholds hypothesized for positive flash production. Thus, our analysis suggests that strong shear may be a necessary, but not sufficient, condition for the production of positive ground flashes. Contrary to earlier reports in the literature, our data indicate the height of the -10-degrees-C isotherm is not a key parameter for positive flash production in warm-season convection. Finally, a link between positive ground flashes and hail is again suggested. C1 NOAA,ENVIRONM RESOURCES LAB,NORMAN,OK 73069. NR 30 TC 51 Z9 53 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 APR PY 1992 VL 120 IS 4 BP 544 EP 553 DI 10.1175/1520-0493(1992)120<0544:PGFPBL>2.0.CO;2 PG 10 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA HK879 UT WOS:A1992HK87900003 ER PT J AU SCOTT, RD PAUWELS, J EYKENS, R BYRNE, J DAWBER, PG GILLIAM, DM AF SCOTT, RD PAUWELS, J EYKENS, R BYRNE, J DAWBER, PG GILLIAM, DM TI THE CHARACTERIZATION OF B-10 AND (LIF)-LI-6 REFERENCE DEPOSITS BY THE MEASUREMENT OF NEUTRON-INDUCED CHARGED-PARTICLE REACTIONS SO NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH SECTION A-ACCELERATORS SPECTROMETERS DETECTORS AND ASSOCIATED EQUIPMENT LA English DT Article AB This paper describes part of a project whose overall aim was the fabrication of a set of B-10 and (LiF)-Li-6 deposits of known area density for use in a measurement of the free neutron lifetime. (n, alpha) rates were measured in a neutron beam in a reproducible geometry and were related to the masses of several of the deposits (determined by isotope dilution mass spectrometry) so that the masses of the remaining deposits, and hence their area densities, could be established. Details are given here of the detection arrangement and of the corrections which have to be made to the charged particle counting rates in order that the masses and counting rates be properly correlated. C1 COMMISS EUROPEAN COMMUNITIES,JOINT RES CTR,CENT BUR NUCL MEASUREMENTS,B-2440 GEEL,BELGIUM. UNIV SUSSEX,SCH MATH & PHYS SCI,BRIGHTON BN1 9QH,E SUSSEX,ENGLAND. NATL INST STAND & TECHNOL,GAITHERSBURG,MD 20899. RP SCOTT, RD (reprint author), SCOTTISH UNIV RES & REACTOR CTR,E KILBRIDE G75 0QU,LANARK,SCOTLAND. NR 4 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 APR 1 PY 1992 VL 314 IS 1 BP 163 EP 170 DI 10.1016/0168-9002(92)90509-3 PG 8 WC Instruments & Instrumentation; Nuclear Science & Technology; Physics, Nuclear; Physics, Particles & Fields SC Instruments & Instrumentation; Nuclear Science & Technology; Physics GA HQ297 UT WOS:A1992HQ29700018 ER PT J AU GRUNING, U MAGERL, A MILDNER, DFR AF GRUNING, U MAGERL, A MILDNER, DFR TI NEUTRON GUIDANCE BY INTERNAL REFLECTIONS IN THIN SILICON-WAFERS SO NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH SECTION A-ACCELERATORS SPECTROMETERS DETECTORS AND ASSOCIATED EQUIPMENT LA English DT Article AB We have performed cold neutron longitudinal transmission measurements through single crystal silicon wafers of 200-mu-m thickness and 50 mm length which have been coated on both sides with nickel to form microguides. Rocking curve measurements with neutrons of a wavelength of 7 angstrom have been conducted on assemblies of straight wafers placed end-to-end for neutron pathways in silicon from 50 to 200 mm, and on curved wafers. In addition. transmission measurements have been carried out on a straight wafer as a function of wavelength. We find that the reflectivity for the internal silicon-nickel interface is 0.988 +/- 0.005. C1 NATL INST STAND & TECHNOL,GAITHERSBURG,MD 20899. RP GRUNING, U (reprint author), INST MAX VON LAUE PAUL LANGEVIN,F-38042 GRENOBLE,FRANCE. RI Magerl, Andreas/E-1797-2013 NR 14 TC 5 Z9 5 U1 0 U2 0 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0168-9002 J9 NUCL INSTRUM METH A JI Nucl. Instrum. Methods Phys. Res. Sect. A-Accel. Spectrom. Dect. Assoc. Equip. PD APR 1 PY 1992 VL 314 IS 1 BP 171 EP 177 DI 10.1016/0168-9002(92)90510-B PG 7 WC Instruments & Instrumentation; Nuclear Science & Technology; Physics, Nuclear; Physics, Particles & Fields SC Instruments & Instrumentation; Nuclear Science & Technology; Physics GA HQ297 UT WOS:A1992HQ29700019 ER PT J AU TANOVIC, N TANOVIC, L FINE, J AF TANOVIC, N TANOVIC, L FINE, J TI INTERFACE WIDTH DEPENDENCE ON SAMPLE TEMPERATURE DURING AUGER SPUTTER DEPTH PROFILING OF CR/NI MULTILAYERED THIN-FILMS SO NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH SECTION B-BEAM INTERACTIONS WITH MATERIALS AND ATOMS LA English DT Article; Proceedings Paper CT 14TH INTERNATIONAL CONF ON ATOMIC COLLISIONS IN SOLIDS ( ICACIS-14 ) CY JUL 28-AUG 02, 1991 CL UNIV SALFORD, SALFORD, ENGLAND SP UNIV SALFORD, CITY SALFORD, BRIT AEROSP, B & P ENGN, ELSEVIER PUBL, FARMER NORTON INT, MANCHESTER INT AIRPORT, MARKEM SYST, VACUUM 91 CONF EXHIBIT, VERTEC HO UNIV SALFORD ID ELECTRON SPECTROSCOPY; METAL-FILMS; RESOLUTION; AES AB A NIST standard reference material (SRM 2135) composed of nine alternating Cr and Ni thin-film layers has been sputter profiled using 1 keV argon ions both at room temperature and at elevated temperature. Interface widths of the Cr-to-Ni and Ni-to-Cr interfaces were monitored using Auger electron spectroscopy. At temperatures ranging from 400 to 700 K, a very pronounced broadening was observed at each of the Cr-to-Ni interfaces. At these elevated temperatures, changes in the widths of the Ni-to-Cr interfaces, however, were slightly less. When previously heated specimens were again profiled at room temperature, the interface widths obtained were virtually unchanged from those measured before heating. We conclude that temperature-assisted radiation enhanced diffusion is occurring during the sputter profiling process at elevated temperatures. RP TANOVIC, N (reprint author), NATL INST STAND & TECHNOL,DIV SURFACE & MICROANAL SCI,GAITHERSBURG,MD 20899, USA. NR 18 TC 10 Z9 10 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 APR PY 1992 VL 67 IS 1-4 BP 491 EP 494 DI 10.1016/0168-583X(92)95858-O PG 4 WC Instruments & Instrumentation; Nuclear Science & Technology; Physics, Atomic, Molecular & Chemical; Physics, Nuclear SC Instruments & Instrumentation; Nuclear Science & Technology; Physics GA HR308 UT WOS:A1992HR30800101 ER PT J AU TANOVIC, N TANOVIC, L FINE, J GAKOVIC, B PANJAN, P POPOVIC, N AF TANOVIC, N TANOVIC, L FINE, J GAKOVIC, B PANJAN, P POPOVIC, N TI MICROTOPOGRAPHY AND INTERFACE WIDTH OF SPUTTER PROFILED CR/NI MULTILAYERED THIN-FILM MATERIALS SO NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH SECTION B-BEAM INTERACTIONS WITH MATERIALS AND ATOMS LA English DT Article; Proceedings Paper CT 14TH INTERNATIONAL CONF ON ATOMIC COLLISIONS IN SOLIDS ( ICACIS-14 ) CY JUL 28-AUG 02, 1991 CL UNIV SALFORD, SALFORD, ENGLAND SP UNIV SALFORD, CITY SALFORD, BRIT AEROSP, B & P ENGN, ELSEVIER PUBL, FARMER NORTON INT, MANCHESTER INT AIRPORT, MARKEM SYST, VACUUM 91 CONF EXHIBIT, VERTEC HO UNIV SALFORD ID AUGER-ELECTRON SPECTROSCOPY; SURFACE-ROUGHNESS; DEPTH RESOLUTION; DEPENDENCE AB Interface widths of sputter profiled Cr/Ni multilayers have been found to depend on the specific sputter deposition technique used in specimen fabrication. Scanning electron microscopy and a sensitive stylus instrument were used to show that these interface widths are related to the microtopography of the profiled surface. We have found that differences in sputter induced microtopography can be attributed to differences in crystallite orientation in the thin-film layers and that these differences in crystallite structure result from the sputter technique employed. C1 UNIV SARAJEVO,FAC ELECT ENGN,YU-71000 SARAJEVO,YUGOSLAVIA. NATL INST STAND & TECHNOL,DIV SURFACE & MICROANAL SCI,GAITHERSBURG,MD 20899. JOZEF STEFAN INST,YU-61000 LJUBLJANA,YUGOSLAVIA. BORIS KIDRIC INST CHEM,YU-11000 BELGRADE,YUGOSLAVIA. RP TANOVIC, N (reprint author), UNIV SARAJEVO,DEPT PHYS,YU-71000 SARAJEVO,YUGOSLAVIA. OI Panjan, Peter/0000-0001-6419-9205 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 0168-583X J9 NUCL INSTRUM METH B JI Nucl. Instrum. Methods Phys. Res. Sect. B-Beam Interact. Mater. Atoms PD APR PY 1992 VL 67 IS 1-4 BP 590 EP 594 DI 10.1016/0168-583X(92)95879-V PG 5 WC Instruments & Instrumentation; Nuclear Science & Technology; Physics, Atomic, Molecular & Chemical; Physics, Nuclear SC Instruments & Instrumentation; Nuclear Science & Technology; Physics GA HR308 UT WOS:A1992HR30800122 ER PT J AU HUANG, Q CAVA, RJ SANTORO, A KRAJEWSKI, JJ PECK, WF AF HUANG, Q CAVA, RJ SANTORO, A KRAJEWSKI, JJ PECK, WF TI NEUTRON POWDER DIFFRACTION STUDY OF THE CRYSTAL-STRUCTURE OF YSR2COCU2O7 AND Y1-XCAXSR2COCU2O7 SO PHYSICA C LA English DT Article ID SUPERCONDUCTIVITY; YBA2CU3O7; COBALT AB The structures of YSr2CoCu2O7 and Y1-xCaxSr2CoCu2O7 have been analyzed by neutron powder diffraction techniques. Both materials crystallize with the symmetry of space group Ima2. The lattice parameters are a = 22.7900(5), b = 5.4516(1), c = 5.4097(1) angstrom for YSr2CoCu2O7, and a = 22.8266(7), b = 5.4312(2), c = 5.4048(2) angstrom for Y1-xCaxSr2CoCu2O7. In the undoped compound, the Co ions exclusively substitute for the copper ions located on the chain sites of the 123 parent structure (YBa2Cu3O6+x). The coordination of Co is tetrahedral. The CoO4 tetrahedra form chains running with a zig-zag configuration along the c-axis of the structure. The oxygen atoms of the CoO layers were found to be disordered over two positions. A re-analysis of the compound YSr2GaCu2O7 showed that this type of disordering is much less pronounced in this material. The disorder of the CoO4 tetrahedra results in the coexistence of two types of chains. In the structure of the doped compound Y1-xCaxSr2CoCu2O7, calcium substitutes for yttrium, but cobalt replaces copper both on the chain sites and in the CuO2 planar sites, thus explaining the lack of superconductivity in this material. The oxygen atoms on the Co layers are more disordered than in the undoped material. C1 AT&T BELL LABS,MURRAY HILL,NJ 07974. RP HUANG, Q (reprint author), NATL INST STAND & TECHNOL,MAT SCI & ENGN LAB,GAITHERSBURG,MD 20899, USA. NR 19 TC 69 Z9 69 U1 0 U2 3 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0921-4534 J9 PHYSICA C JI Physica C PD APR 1 PY 1992 VL 193 IS 1-2 BP 196 EP 206 DI 10.1016/0921-4534(92)90887-I PG 11 WC Physics, Applied SC Physics GA HP252 UT WOS:A1992HP25200028 ER PT J AU GELTMAN, S AF GELTMAN, S TI CALCULATIONS ON LASER-INDUCED COLLISIONAL ENERGY-TRANSFER SO PHYSICAL REVIEW A LA English DT Article ID INDUCED INELASTIC-COLLISIONS; HIGH-RESOLUTION; WING BEHAVIOR; PROFILES AB We examine theoretically the behavior of cross sections for laser-induced collisional energy transfer (LICET) over a wide range of detunings and laser intensities for the two-atom pairs Li-Sr and Eu-Sr which have been previously studied experimentally. These two cases are complementary in that the laser and collisional interactions enter in opposite orders, and their level structures are such as to give weakfield line shapes of opposite asymmetry and intensity shift. A three-state model is used and the Bambini-Berman formula for the weak-field quasistatic wing is verified. At high intensities the peak cross section is found to go through a maximum and the LICET profile is found to become symmetric about a shifted center with notable departures from a uniform falloff in the far quasistatic wing, apparently arising from radiative collisional interference effects. RP GELTMAN, S (reprint author), UNIV COLORADO,NATL INST STAND & TECHNOL,JOINT INST LAB ASTROPHYS,BOULDER,CO 80309, USA. NR 16 TC 21 Z9 22 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 APR 1 PY 1992 VL 45 IS 7 BP 4792 EP 4798 DI 10.1103/PhysRevA.45.4792 PN A PG 7 WC Optics; Physics, Atomic, Molecular & Chemical SC Optics; Physics GA HN474 UT WOS:A1992HN47400074 ER PT J AU GELTMAN, S AF GELTMAN, S TI VOLKOV LIMIT FOR ATOMIC IONIZATION BY ULTRAINTENSE LASER FIELDS SO PHYSICAL REVIEW A LA English DT Note ID MODEL ATOM; MULTIPHOTON IONIZATION AB We examine the Volkov limit in the interaction of an atom with an ultrastrong laser field, where the atom-laser coupling energy becomes larger than the atomic binding energy. The full time-dependent wave function is expressible as an expansion in the atomic potential. Numerical results are obtained for the ionization probability of a one-dimensional delta-potential model atom, for which full dynamical solutions are also found. We find uniform convergence toward full ionization with increasing field strength, with no sign of ground-state stabilization. C1 NATL INST STAND & TECHNOL,BOULDER,CO 80309. RP GELTMAN, S (reprint author), UNIV COLORADO,JOINT INST LAB ASTROPHYS,BOULDER,CO 80309, USA. NR 15 TC 25 Z9 25 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 APR 1 PY 1992 VL 45 IS 7 BP 5293 EP 5296 DI 10.1103/PhysRevA.45.5293 PN B PG 4 WC Optics; Physics, Atomic, Molecular & Chemical SC Optics; Physics GA HN476 UT WOS:A1992HN47600063 ER PT J AU GILLASPY, JD MARTIN, WC AF GILLASPY, JD MARTIN, WC TI MEASUREMENT OF THE LAMB SHIFTS IN SINGLET LEVELS OF ATOMIC HELIUM - COMMENT SO PHYSICAL REVIEW A LA English DT Letter ID RYDBERG STATES; RETARDATION AB Lichten, Shiner, and Zhou [Phys. Rev. A 43, 1663 (1991)] have stated that their precision measurements of Rydberg states of helium confirm the existence of intra-atomic Casimir forces. This interpretation misidentifies the Casimir-force shift, which in fact is too small to be detected with their present level of accuracy. RP GILLASPY, JD (reprint author), NATL INST STAND & TECHNOL, GAITHERSBURG, MD 20899 USA. NR 18 TC 0 Z9 0 U1 0 U2 1 PU AMER PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 1050-2947 EI 1094-1622 J9 PHYS REV A JI Phys. Rev. A PD APR 1 PY 1992 VL 45 IS 7 BP 5315 EP 5316 DI 10.1103/PhysRevA.45.5315 PN B PG 2 WC Optics; Physics, Atomic, Molecular & Chemical SC Optics; Physics GA HN476 UT WOS:A1992HN47600069 ER PT J AU KEIMER, B AHARONY, A AUERBACH, A BIRGENEAU, RJ CASSANHO, A ENDOH, Y ERWIN, RW KASTNER, MA SHIRANE, G AF KEIMER, B AHARONY, A AUERBACH, A BIRGENEAU, RJ CASSANHO, A ENDOH, Y ERWIN, RW KASTNER, MA SHIRANE, G TI NEEL TRANSITION AND SUBLATTICE MAGNETIZATION OF PURE AND DOPED LA2CUO4 SO PHYSICAL REVIEW B LA English DT Article ID HEISENBERG-ANTIFERROMAGNET; PHASE-TRANSITIONS; SPIN CORRELATIONS; LOW-TEMPERATURES; DYNAMICS; CONDUCTIVITY; EXCITATIONS; YBA2CU3O6+X AB We have measured the sublattice magnetization of stoichiometric La2CuO4 (T(N) = 325 K) and La2Cu0.95Zn0.05O4 (T(N) = 157 K). We discuss the data for La2CuO4 and other lamellar copper oxides in terms of the quantum Heisenberg model including weak XY anisotropy and interlayer coupling. Spin-wave theory and a generalized Schwinger-boson mean-field theory are used to predict the ordered moment as a function of temperature without adjustable parameters. We also discuss the influence of different dopants on the Neel temperature and sublattice magnetization. C1 TEL AVIV UNIV, SCH PHYS & ASTRON, IL-69978 TEL AVIV, ISRAEL. BOSTON UNIV, DEPT PHYS, BOSTON, MA 02215 USA. TOHOKU UNIV, DEPT PHYS, SENDAI, MIYAGI 980, JAPAN. NATL INST STAND & TECHNOL, GAITHERSBURG, MD 20899 USA. BROOKHAVEN NATL LAB, UPTON, NY 11973 USA. RP MIT, CTR MAT SCI & ENGN, CAMBRIDGE, MA 02139 USA. NR 33 TC 131 Z9 131 U1 1 U2 9 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 APR 1 PY 1992 VL 45 IS 13 BP 7430 EP 7435 DI 10.1103/PhysRevB.45.7430 PG 6 WC Physics, Condensed Matter SC Physics GA HL993 UT WOS:A1992HL99300056 ER PT J AU BURTON, BP OSBURN, JE PASTUREL, A AF BURTON, BP OSBURN, JE PASTUREL, A TI THEORETICAL CALCULATIONS OF THE NIAL-NITI PHASE-DIAGRAM BASED ON 1ST-PRINCIPLES LINEAR-MUFFIN-TIN-ORBITAL AND FULL-POTENTIAL LINEARLY-AUGMENTED PLANE-WAVE COHESIVE-ENERGY CALCULATIONS SO PHYSICAL REVIEW B LA English DT Article ID ALLOYS AB Linear-muffin-tin-orbital and full-potential linearly-augmented plane-wave calculations of cohesive energies were performed for observed and hypothetical ordered structures in the system NiAl-NiTi. Differences in cohesive energies were parametrized in both the Connolly and Williams and epsilon-G approximations, and the resulting effective-cluster interactions were used to calculate theoretical phase diagrams. Long-range "elastic" interactions and short-range effective-cluster interactions are predicted to be causes of the observed immiscibility between B2 and L2(1) phases. C1 USN, RES LAB, COMPLEX SYST THEORY BRANCH, WASHINGTON, DC 20375 USA. ECOLE NATL ELECTROCHIM & ELECTROMET GRENOBLE, THERMODYNAM & PHYSICOCHIM MET LAB, F-38402 ST MARTIN DHERES, FRANCE. RP NATL INST STAND & TECHNOL, MAT SCI & ENGN LAB, GAITHERSBURG, MD 20899 USA. NR 24 TC 24 Z9 24 U1 0 U2 2 PU AMER PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 1098-0121 EI 1550-235X J9 PHYS REV B JI Phys. Rev. B PD APR 1 PY 1992 VL 45 IS 14 BP 7677 EP 7683 DI 10.1103/PhysRevB.45.7677 PG 7 WC Physics, Condensed Matter SC Physics GA HN477 UT WOS:A1992HN47700007 ER PT J AU EGELHOFF, WF KIEF, MT AF EGELHOFF, WF KIEF, MT TI ANTIFERROMAGNETIC COUPLING IN FE/CU/FE AND CO/CU/CO MULTILAYERS ON CU(111) SO PHYSICAL REVIEW B LA English DT Article ID LAYERED MAGNETIC-STRUCTURES; X-RAY PHOTOELECTRON; ENHANCED MAGNETORESISTANCE; GIANT MAGNETORESISTANCE; EPITAXIAL-GROWTH; AUGER-ELECTRON; FE LAYERS; SUPERLATTICES; EXCHANGE; CR AB The magneto-optical Kerr effect has been used to investigate the exchange coupling between Fe and Co bilayers through Cu spacer layers. The films were grown on a Cu(111) substrate by molecular-beam-epitaxy (MBE) techniques under a variety of conditions, including both high vacuum and ultrahigh vacuum, substrate temperatures of 80, 300, and 500 K, and in the presence of as well as in the absence of electron bombardment. None of these films showed consistent evidence of antiferromagnetic (AFM) coupling, and there was no evidence of any consistent trends attributable to oscillatory AFM coupling. These results stand in marked contrast to results recently reported on similar multilayers that were grown by magnetron sputtering methods and that exhibit the giant magnetoresistance effect. These magnetron-grown multilayers, which are reported to be (111) textured, exhibit pronounced oscillatory AFM coupling. One possible resolution of these conflicting observations lies in the fact that oscillatory AFM coupling does occur in MBE-grown multilayers on Cu(100). Preliminary x-ray-diffraction polefigure measurements on three of the magnetron-grown multilayers indicate that the tendency to (111) texture is not very strong, and that the multilayers contain crystalline grains other than (111). Thus, the AFM coupling that these multilayers exhibit could be at least partly a result of a minority constituent of crystalline grains oriented at or near (100). However, it cannot be proven that the near-(100) grains are entirely responsible for the AFM coupling in the magnetron-grown multilayers. Grains of other orientation may also contribute, but surprisingly, the present work implies that the (111)-oriented grains do not contribute. RP EGELHOFF, WF (reprint author), NATL INST STAND & TECHNOL,DIV SURFACE & MICROANAL SCI,GAITHERSBURG,MD 20899, USA. NR 70 TC 125 Z9 125 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 APR 1 PY 1992 VL 45 IS 14 BP 7795 EP 7804 DI 10.1103/PhysRevB.45.7795 PG 10 WC Physics, Condensed Matter SC Physics GA HN477 UT WOS:A1992HN47700021 ER PT J AU SOARES, CG AF SOARES, CG TI A METHOD FOR THE CALIBRATION OF CONCAVE SR-90+Y-90 OPHTHALMIC APPLICATORS SO PHYSICS IN MEDICINE AND BIOLOGY LA English DT Note RP SOARES, CG (reprint author), NATL INST STAND & TECHNOL,DIV IONIZING RADIAT,GAITHERSBURG,MD 20899, USA. RI Grams, Michael/G-5197-2011 NR 10 TC 6 Z9 6 U1 0 U2 0 PU IOP PUBLISHING LTD PI BRISTOL PA TECHNO HOUSE, REDCLIFFE WAY, BRISTOL, ENGLAND BS1 6NX SN 0031-9155 J9 PHYS MED BIOL JI Phys. Med. Biol. PD APR PY 1992 VL 37 IS 4 BP 1005 EP 1007 PG 3 WC Engineering, Biomedical; Radiology, Nuclear Medicine & Medical Imaging SC Engineering; Radiology, Nuclear Medicine & Medical Imaging GA HP768 UT WOS:A1992HP76800014 ER PT J AU SONG, JF VORBURGER, TV RUBERT, P AF SONG, JF VORBURGER, TV RUBERT, P TI COMPARISON BETWEEN PRECISION ROUGHNESS MASTER SPECIMENS AND THEIR ELECTROFORMED REPLICAS SO PRECISION ENGINEERING-JOURNAL OF THE AMERICAN SOCIETY FOR PRECISION ENGINEERING LA English DT Article DE CALIBRATION; COMPARISON; ELECTROFORMING; FLATNESS; HARDNESS; MASTER; PROFILE; REPLICA; ROUGHNESS; SPECIMEN; SURFACE AB Two random profile precision roughness calibration specimens with R(a) = 0.028 and 0.043-mu-m are compared with their electroformed replicas. Measurements of surface texture and roughness parameter values show very good agreement. Fluctuations in the R(a) values across the replicas track those across the masters to within 1.8 nm. However, the form errors of the replicas, approximately 0.6-mu-m over a 3.2 x 2.6 mm2 area, are much bigger than those of the masters, and their hardness (HV = 243) is not as good as the master specimens' (HV = 852). RP SONG, JF (reprint author), NATL INST STAND & TECHNOL,GAITHERSBURG,MD 20899, USA. NR 0 TC 9 Z9 9 U1 0 U2 0 PU BUTTERWORTH-HEINEMANN PI WOBURN PA 225 WILDWOOD AVE #UNITB PO BOX 4500, WOBURN, MA 01801-2084 SN 0141-6359 J9 PRECIS ENG JI Precis. Eng.-J. Am. Soc. Precis. Eng. PD APR PY 1992 VL 14 IS 2 BP 84 EP 90 DI 10.1016/0141-6359(92)90053-Y PG 7 WC Engineering, Multidisciplinary; Engineering, Manufacturing; Nanoscience & Nanotechnology; Instruments & Instrumentation SC Engineering; Science & Technology - Other Topics; Instruments & Instrumentation GA HQ387 UT WOS:A1992HQ38700003 ER PT J AU HEINTZ, R JOYCE, J AF HEINTZ, R JOYCE, J TI SMALL VERTICAL RACEWAYS FOR REARING JUVENILE SALMON SO PROGRESSIVE FISH-CULTURIST LA English DT Note AB We describe a micro-vertical raceway, a small floating container, for rearing small populations of fish. The container is a 170.6-L polyethylene drum fitted to a controlled water supply. An array of these containers was used to rear juvenile salmon simultaneously in 60 groups (200 fish each) to 6.0-g size. We compared growth rates of juvenile chinook salmon (Oncorhynchus tshawytscha) reared in these containers with those reared in large (70.8-m3) vertical raceways and conclude that micro-vertical raceways do not adversely affect fish growth. RP HEINTZ, R (reprint author), ALASKA FISHERIES SCI CTR,NATL MARINE FISHERIES SERV,AUKE BAY LAB,11305 GLACIER HIGHWAY,JUNEAU,AK 99801, USA. NR 5 TC 7 Z9 7 U1 0 U2 0 PU AMER FISHERIES SOC PI BETHESDA PA 5410 GROSVENOR LANE SUITE 110, BETHESDA, MD 20814-2199 SN 0033-0779 J9 PROG FISH CULT JI Progress. Fish-Cult. PD APR PY 1992 VL 54 IS 2 BP 105 EP 108 DI 10.1577/1548-8640(1992)054<0105:SVRFRJ>2.3.CO;2 PG 4 WC Fisheries SC Fisheries GA JD752 UT WOS:A1992JD75200008 ER PT J AU CURRIE, LA AF CURRIE, LA TI IN PURSUIT OF ACCURACY - NOMENCLATURE, ASSUMPTIONS, AND STANDARDS SO PURE AND APPLIED CHEMISTRY LA English DT Article; Proceedings Paper CT INTERNATIONAL CONGRESS OF ANALYTICAL SCIENCES CY AUG 25-31, 1991 CL CHIBA, JAPAN ID MODELS AB Accuracy is the central measure of quality in Analytical Science. Three topics, essential in the pursuit of accuracy, especially in the exposure and reduction of the "big" errors in analytical measurements, are reviewed in this article. The first topic, Analytical Nomenclature, lies at the heart of any effort to realize and communicate the nature and level of accuracy of the Chemical Measurement Process (CMP). The discussion centers about the historic role of IUPAC in this endeavor, together with some outstanding problems in Analytical Nomenclature, particularly as related to detection and identification. The second topic comprises assumptions and standards (materials and data) that are crucial in the search for major errors and in the control of accuracy, both within and between laboratories. Standard (Certified) Reference Materials have long been central to this effort, but more recently they have been joined by Standard Test Data. The latter, data sets having known characteristics, designed to simulate the structure of complex analytical signals, show great promise for the control of quality in the computational phase of the CMP. The final topic relates to Revolutions in Analytical Measurement Science that can make the most profound impact on accuracy: revolutions in sampling, measurement, and computation. Two illustrations are presented: (1) Accelerator Mass Spectrometry, a fundamentally new approach to atomic and isotopic mass spectrometry that makes possible the direct measurement of element and isotope ratios as small as 10(-16); and (2) Exploratory Statistical Graphics, a data visualization tool that permits analytical scientists to directly apply their intuitive "vision" to the assessment of multivariate data quality, and to search for unsuspected relationships in complex chemical datasets. RP CURRIE, LA (reprint author), NATL INST STAND & TECHNOL,GAITHERSBURG,MD 20899, USA. NR 64 TC 14 Z9 14 U1 0 U2 0 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 APR PY 1992 VL 64 IS 4 BP 455 EP 472 DI 10.1351/pac199264040455 PG 18 WC Chemistry, Multidisciplinary SC Chemistry GA HM383 UT WOS:A1992HM38300001 ER PT J AU FU, J YOUNG, RD VORBURGER, TV AF FU, J YOUNG, RD VORBURGER, TV TI LONG-RANGE SCANNING FOR SCANNING TUNNELING MICROSCOPY SO REVIEW OF SCIENTIFIC INSTRUMENTS LA English DT Article ID NANOMETER RESOLUTION AB We report a scanning tunneling microscope (STM) with 500-mu-m x 500-mu-m field of view. It departs from past designs in that a long-range X-Y stage carries the specimen and scans while the STM head is held stationary. The STM head is capable of scanning with a range of 8-mu-m. Combining the capability of tip scanning and X-Y stage scanning yields a wide dynamic range and has useful applications for measuring optical surfaces. RP FU, J (reprint author), NATL INST STAND & TECHNOL,GAITHERSBURG,MD 20899, USA. NR 22 TC 22 Z9 32 U1 0 U2 3 PU AMER INST PHYSICS PI WOODBURY PA CIRCULATION FULFILLMENT DIV, 500 SUNNYSIDE BLVD, WOODBURY, NY 11797-2999 SN 0034-6748 J9 REV SCI INSTRUM JI Rev. Sci. Instrum. PD APR PY 1992 VL 63 IS 4 BP 2200 EP 2205 DI 10.1063/1.1143139 PN 1 PG 6 WC Instruments & Instrumentation; Physics, Applied SC Instruments & Instrumentation; Physics GA HL552 UT WOS:A1992HL55200016 ER PT J AU RUDD, ME KIM, YK MADISON, DH GAY, TJ AF RUDD, ME KIM, YK MADISON, DH GAY, TJ TI ELECTRON PRODUCTION IN PROTON COLLISIONS WITH ATOMS AND MOLECULES - ENERGY-DISTRIBUTIONS SO REVIEWS OF MODERN PHYSICS LA English DT Review ID DIFFERENTIAL CROSS-SECTIONS; PROJECTILE-CHARGE DEPENDENCE; COUPLED-STATE CALCULATIONS; 200-500 KEV PROTONS; K-SHELL IONIZATION; SECONDARY ELECTRONS; ANGULAR-DISTRIBUTION; WATER-VAPOR; INTERMEDIATE ENERGIES; GLAUBER APPROXIMATION AB All known data on the energy distribution of secondary electrons from collisions of protons with atoms and molecules have been reviewed and differential cross sections have been collected. The two experimental methods used to obtain the data are discussed and possible sources of error pointed out. Theoretical treatments are reviewed and several methods of checking the consistency of the data are discussed. Two semiempirical models have been chosen to represent the differential cross sections, and parameters for these models are given which fit the average of the experimental data, subject to known constraints. Recommended values of differential cross sections are given for ten target gases by means of these models. C1 NATL INST STAND & TECHNOL,GAITHERSBURG,MD 20899. UNIV MISSOURI,DEPT PHYS,ROLLA,MO 65401. UNIV MISSOURI,ATOM & MOLEC RES LAB,ROLLA,MO 65401. RP RUDD, ME (reprint author), UNIV NEBRASKA,DEPT PHYS & ASTRON,BEHLEN LAB,LINCOLN,NE 68588, USA. NR 170 TC 250 Z9 250 U1 0 U2 10 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 0034-6861 J9 REV MOD PHYS JI Rev. Mod. Phys. PD APR PY 1992 VL 64 IS 2 BP 441 EP 490 DI 10.1103/RevModPhys.64.441 PG 50 WC Physics, Multidisciplinary SC Physics GA HN233 UT WOS:A1992HN23300003 ER PT J AU RICKER, RE FINK, JL HARRIS, JS SHAPIRO, AJ AF RICKER, RE FINK, JL HARRIS, JS SHAPIRO, AJ TI EVIDENCE FOR FILM-INDUCED CLEAVAGE IN RHODIUM PLATED NICKEL SO SCRIPTA METALLURGICA ET MATERIALIA LA English DT Article ID STRESS-CORROSION CRACKING; BRITTLE-FRACTURE; SINGLE-CRYSTALS; ALPHA-BRASS; SURFACES; METALS RP RICKER, RE (reprint author), US DEPT COMMERCE TECHNOL ADM,NATL INST STAND & TECHNOL,DIV MET,GAITHERSBURG,MD 20899, USA. RI Ricker, Richard/H-4880-2011 OI Ricker, Richard/0000-0002-2871-4908 NR 38 TC 6 Z9 6 U1 0 U2 2 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD, ENGLAND OX5 1GB SN 0956-716X J9 SCRIPTA METALL MATER JI Scr. Metall. Materialia PD APR 1 PY 1992 VL 26 IS 7 BP 1019 EP 1023 DI 10.1016/0956-716X(92)90223-2 PG 5 WC Materials Science, Multidisciplinary; Metallurgy & Metallurgical Engineering SC Materials Science; Metallurgy & Metallurgical Engineering GA HK521 UT WOS:A1992HK52100003 ER PT J AU SALOMAN, EB AF SALOMAN, EB TI A RESONANCE IONIZATION SPECTROSCOPY RESONANCE IONIZATION MASS-SPECTROMETRY DATA SERVICE .3. DATA SHEETS FOR SB, BI, P, NA AND SN SO SPECTROCHIMICA ACTA PART B-ATOMIC SPECTROSCOPY LA English DT Article ID MULTIPHOTON IONIZATION; HYPERFINE-STRUCTURE; NUCLEAR MOMENTS; TRACE-ELEMENTS; ENERGY-LEVELS; SODIUM; SPECTRUM; BISMUTH; ATOMS; WATER AB A data service has been established at the National Institute of Standards and Technology to provide the necessary information to apply the techniques of resonance ionization spectroscopy (RIS) and resonance ionization mass spectrometry (RIMS) to routine use in analytical chemistry. This service collects and calculates the relevant atomic data, chooses appropriate resonance ionization schemes, and indicates pertinent operating details of successful RIMS studies. The first group of data sheets was published previously covering the elements As, B, Cd, C, Ge, Au, Fe, Pb. Si, and Zn. The second group published covered the elements Al, Ca, Cs, Cr, Co, Cu, Kr, Mg, Hg, and Ni. The third group of data sheets is presented here. It covers the elements Sb, Bi, P, Na and Sn. Others will be published periodically. Reprints of RIS/RIMS work are solicited so that those efforts may be included in future data sheets. RP NATL INST STAND & TECHNOL, DIV ELECTR & OPT PHYS, GAITHERSBURG, MD 20899 USA. NR 68 TC 25 Z9 28 U1 0 U2 3 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLAND SN 0584-8547 J9 SPECTROCHIM ACTA B JI Spectroc. Acta Pt. B-Atom. Spectr. PD APR PY 1992 VL 47 IS 4 BP 517 EP 543 DI 10.1016/0584-8547(92)80044-H PG 27 WC Spectroscopy SC Spectroscopy GA HP179 UT WOS:A1992HP17900004 ER PT J AU COLLIER, TK SINGH, SV AWASTHI, YC VARANASI, U AF COLLIER, TK SINGH, SV AWASTHI, YC VARANASI, U TI HEPATIC XENOBIOTIC METABOLIZING ENZYMES IN 2 SPECIES OF BENTHIC FISH SHOWING DIFFERENT PREVALENCES OF CONTAMINANT-ASSOCIATED LIVER NEOPLASMS SO TOXICOLOGY AND APPLIED PHARMACOLOGY LA English DT Note ID SOLE PAROPHRYS-VETULUS; GLUTATHIONE-S-TRANSFERASE; ENGLISH SOLE; PUGET-SOUND; DETOXICATION; WASHINGTON; SEDIMENTS; RAT C1 UNIV TEXAS,MED BRANCH,DEPT HUMAN BIOL CHEM & GENET,GALVESTON,TX 77550. 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 29 TC 85 Z9 88 U1 1 U2 4 PU ACADEMIC PRESS INC JNL-COMP SUBSCRIPTIONS PI SAN DIEGO PA 525 B ST, STE 1900, SAN DIEGO, CA 92101-4495 SN 0041-008X J9 TOXICOL APPL PHARM JI Toxicol. Appl. Pharmacol. PD APR PY 1992 VL 113 IS 2 BP 319 EP 324 DI 10.1016/0041-008X(92)90131-B PG 6 WC Pharmacology & Pharmacy; Toxicology SC Pharmacology & Pharmacy; Toxicology GA HP304 UT WOS:A1992HP30400020 PM 1561641 ER PT J AU FOGARTY, MJ AF FOGARTY, MJ TI MARINE RECRUITMENT - REPLY SO TRENDS IN ECOLOGY & EVOLUTION LA English DT Letter ID LIFE RP FOGARTY, MJ (reprint author), NOAA,NATL MARINE FISHERIES SERV,WOODS HOLE,MA 02543, USA. NR 11 TC 3 Z9 3 U1 0 U2 0 PU ELSEVIER SCI LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD, OXON, ENGLAND OX5 1GB SN 0169-5347 J9 TRENDS ECOL EVOL JI Trends Ecol. Evol. PD APR PY 1992 VL 7 IS 4 BP 135 EP 136 DI 10.1016/0169-5347(92)90154-4 PG 2 WC Ecology; Evolutionary Biology; Genetics & Heredity SC Environmental Sciences & Ecology; Evolutionary Biology; Genetics & Heredity GA HL429 UT WOS:A1992HL42900015 PM 21235984 ER PT J AU KLAUS, EE DUDA, JL WANG, JC AF KLAUS, EE DUDA, JL WANG, JC TI STUDY OF COPPER-SALTS AS HIGH-TEMPERATURE OXIDATION INHIBITORS SO TRIBOLOGY TRANSACTIONS LA English DT Article AB Oil-soluble copper salts such as copper naphthenate have been evaluated as additives to mineral oil, synthetic hydrocarbon, and polyol ester base stocks in the Penn State microoxidation test. These tests were carried out at 225-degrees-C under test conditions which show good agreement with the behavior of automotive crankcase oils in the III-series hot engine test. At concentrations of 200 ppm of copper in a mineral oil, the primary oxidation rate of the mineral oil is increased with the conversion of these primary oxidation products, but further reaction to condensation polymers is substantially decreased. These effects can be seen in both low-carbon steel systems and glass systems. At concentration levels of 2000 ppm copper in the mineral oil, copper is a very effective oxidation inhibitor, and also inhibits condensation polymerization reactions of the primary oxidation products. At these high concentrations, copper also is an effective metal deactivator. Iron corrosion products from a low-carbon steel catalyst surface are essentially stopped by the action of the copper additive. Soluble copper salts are equally effective in the synthetic hydrocarbon and polyol ester studied. The use of 2000 ppm soluble copper in these base stocks produces a lubricant that compares favorably in oxidative stability with the best commercial SAE-grade automotive crankcase oils. In the prevention or delay of deposit formation, 2000 ppm of soluble copper in a mineral oil appears to be superior to typical state-of-the-art SAE crankcase oils. C1 NATL INST STAND & TECHNOL,GAITHERSBURG,MD 20899. RP KLAUS, EE (reprint author), PENN STATE UNIV,DEPT CHEM ENGN,UNIV PK,PA 16802, USA. NR 2 TC 13 Z9 13 U1 0 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 APR PY 1992 VL 35 IS 2 BP 316 EP 324 DI 10.1080/10402009208982123 PG 9 WC Engineering, Mechanical SC Engineering GA HP626 UT WOS:A1992HP62600013 ER PT J AU BIRGENEAU, RJ ERWIN, RW GEHRING, PM KASTNER, MA KEIMER, B SATO, M SHAMOTO, S SHIRANE, G TRANQUADA, J AF BIRGENEAU, RJ ERWIN, RW GEHRING, PM KASTNER, MA KEIMER, B SATO, M SHAMOTO, S SHIRANE, G TRANQUADA, J TI TEMPERATURE SCALING OF THE INTEGRATED DYNAMIC SUSCEPTIBILITY IN YBA2CU3O6.5 (T(C) = 50-K) SO ZEITSCHRIFT FUR PHYSIK B-CONDENSED MATTER LA English DT Article ID MAGNETIC EXCITATIONS; NEUTRON-SCATTERING; NORMAL STATE; SUPERCONDUCTIVITY; OXIDES AB The magnetic neutron scattering cross section in a crystal YBa2Cu3O6.5 (T(c) = 50 K) has been measured for energies between 4.5 meV and 15 meV and temperatures between 10 K and 275 K. From these data we extract the generalized susceptibility integrated around the (pi, pi) position [GRAPHICS] with those at 8.3 and 33.1 meV from a previous study. It is found that I(omega, T) exhibits the simple temperature scaling form found previously in La2-xSrxCuO4. Specifically, in YBa2Cu3O6.5, I(omega, T) = I(omega, 0) 2/pi tan-1 (omega/0.9 T). Implications of this behavior for the d.c. and infrared conductivity are discussed. C1 NATL INST STAND & TECHNOL, GAITHERSBURG, MD 20899 USA. NAGOYA UNIV, NAGOYA 46401, JAPAN. BROOKHAVEN NATL LAB, DEPT PHYS, UPTON, NY 11973 USA. RP BIRGENEAU, RJ (reprint author), MIT, DEPT PHYS, CAMBRIDGE, MA 02139 USA. RI Tranquada, John/A-9832-2009; OI Tranquada, John/0000-0003-4984-8857; Gehring, Peter/0000-0002-9236-2046 NR 27 TC 45 Z9 45 U1 0 U2 1 PU SPRINGER PI NEW YORK PA 233 SPRING ST, NEW YORK, NY 10013 USA SN 0722-3277 J9 Z PHYS B CON MAT JI Z. Phys. B-Condens. Mat. PD APR PY 1992 VL 87 IS 1 BP 15 EP 19 DI 10.1007/BF01308252 PG 5 WC Physics, Condensed Matter SC Physics GA HM032 UT WOS:A1992HM03200002 ER PT J AU PARK, GS CUNNINGHAM, CE CABRERA, B HUBER, ME AF PARK, GS CUNNINGHAM, CE CABRERA, B HUBER, ME TI VORTEX PINNING FORCE IN A SUPERCONDUCTING NIOBIUM STRIP SO PHYSICAL REVIEW LETTERS LA English DT Article ID THIN-FILMS; ELEMENTARY AB Using a SQUID-based technique, we measure the Lorentz force needed to depin a single trapped vortex in a superconducting Nb strip. The vortex is trapped by heating a portion of the strip above its critical temperature T(c) with a laser pulse. Between 3.0 and 5.5 K, the pinning force obeys a power law f(p) = f(p)(0)(1-T/T(c))n, where f(p)(0) = (4.1 +/- 0.4) x 10(-4) N/m and n = 1.9 +/- 0.1. We have determined at a confidence level of 99.2% that we trap single vortices, rather than multiple vortices or vortex-antivortex pairs. C1 NATL INST STAND & TECHNOL,DIV ELECTROMAGNET TECHNOL,BOULDER,CO 80303. RP PARK, GS (reprint author), STANFORD UNIV,DEPT PHYS,STANFORD,CA 94305, USA. RI Huber, Martin/B-3354-2011 NR 7 TC 18 Z9 18 U1 0 U2 2 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 0031-9007 J9 PHYS REV LETT JI Phys. Rev. Lett. PD MAR 23 PY 1992 VL 68 IS 12 BP 1920 EP 1922 DI 10.1103/PhysRevLett.68.1920 PG 3 WC Physics, Multidisciplinary SC Physics GA HK319 UT WOS:A1992HK31900035 ER PT J AU STAVN, RH WEIDEMANN, AD AF STAVN, RH WEIDEMANN, AD TI RAMAN-SCATTERING IN OCEAN OPTICS - QUANTITATIVE ASSESSMENT OF INTERNAL RADIANT EMISSION SO APPLIED OPTICS LA English DT Article DE RAMAN SCATTERING; OCEAN OPTICS; ANOMALOUS OCEAN OPTICAL PROPERTIES; PHOTON BUDGETS ID DISSOLVED ORGANIC-MATTER; NATURAL-WATERS; LIGHT; FLUORESCENCE; ATTENUATION; CHLOROPHYLL; ABSORPTION; IRRADIANCE; SEA; REFLECTANCE AB Raman-scattering activity in clear ocean waters is further documented from Monte Carlo simulations and optical data that are collected in the Sargasso Sea. A method is proposed, based on the anomalous absorption coefficient for a nonconservative irradiance field, to assess the percentile composition of internal radiant emission for the irradiance field at any depth. C1 NATL OCEANOG & ATMOSPHER RES LAB,BAY ST LOUIS,MS 39529. RP STAVN, RH (reprint author), UNIV N CAROLINA,DEPT BIOL,GREENSBORO,NC 27412, USA. NR 53 TC 11 Z9 11 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 MAR 20 PY 1992 VL 31 IS 9 BP 1294 EP 1303 PG 10 WC Optics SC Optics GA HJ278 UT WOS:A1992HJ27800026 PM 20720758 ER PT J AU WANG, ZR QU, QY LUO, D MCCRAY, R MACLOW, MM AF WANG, ZR QU, QY LUO, D MCCRAY, R MACLOW, MM TI THE SEMICIRCULAR SHELL OF CTB-109 SO ASTROPHYSICAL JOURNAL LA English DT Article DE INTERSTELLAR, MATTER; NEBULAE, INDIVIDUAL (CTB-109); NEBULAE, SUPERNOVA REMNANTS; X-RAYS, SOURCES ID X-RAY PULSAR; SUPERNOVA REMNANT G109.1-1.0; RADIO OBSERVATIONS; 1E 2259+586; EXTRAORDINARY; SUPERBUBBLES; PLASMA; CLOUD AB The radio and X-ray images of the supernova remnant CTB 109 have the morphology of a semicircular shell. We show that such a structure is a natural result of a supernova explosion (with energy E = 3.6 x 10(50) ergs) that occurred 1.3 x 10(4) yr ago near an interface between the diffuse (density n0 = 0.13 cm-3) interstellar medium and a dense (n(c),0 = 36 cm-3) molecular cloud. The calculated X-ray, infrared, and radio fluxes agree fairly well with the observed values. C1 NANJING UNIV,DEPT ASTRON,NANJING,PEOPLES R CHINA. UNIV COLORADO,NATL INST STAND & TECHNOL,JOINT INST LAB ASTROPHYS,BOULDER,CO 80302. NASA,AMES RES CTR,MOFFETT FIELD,CA 94035. RP WANG, ZR (reprint author), CHINA CTR ADV SCI & TECHNOL,CTR ASTRON & ASTROPHYS,NANJING,PEOPLES R CHINA. OI Mac Low, Mordecai-Mark/0000-0003-0064-4060 NR 34 TC 19 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 MAR 20 PY 1992 VL 388 IS 1 BP 127 EP 130 DI 10.1086/171134 PN 1 PG 4 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA HK566 UT WOS:A1992HK56600012 ER PT J AU SOLER, T STRANGE, WE HOTHEM, LD AF SOLER, T STRANGE, WE HOTHEM, LD TI ACCURATE DETERMINATION OF CARTESIAN COORDINATES AT GEODETIC STATIONS USING THE GLOBAL POSITIONING SYSTEM SO GEOPHYSICAL RESEARCH LETTERS LA English DT Article AB Comparison of Cartesian coordinates determined at collocated sites using two independent space techniques, very long baseline interferometry (VLBI) and Global Positioning System (GPS), shows remarkable agreement even when the points in question span transcontinental distances. The results corroborate the capabilities of commercial dual-frequency GPS receivers to perform geodetic work at the highest available accuracy. Adjusted geocentric coordinates of a configuration of GPS stations well distributed along the eastern half of the United States were accurately determined (better than 10(-8)) in the rigorously defined International Earth Rotation Service (IERS) terrestrial reference frame ITRF 89. C1 US GEOL SURVEY,RESTON,VA 22092. RP SOLER, T (reprint author), NOAA,NATL OCEAN SERV,C & GS,NATL GEODET SURVEY,ROCKVILLE,MD 20852, USA. RI Soler, Tomas/F-6386-2010 NR 8 TC 4 Z9 4 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 MAR 20 PY 1992 VL 19 IS 6 BP 533 EP 536 DI 10.1029/92GL00262 PG 4 WC Geosciences, Multidisciplinary SC Geology GA HK981 UT WOS:A1992HK98100003 ER PT J AU BODHAINE, BA HARRIS, JM OGREN, JA HOFMANN, DJ AF BODHAINE, BA HARRIS, JM OGREN, JA HOFMANN, DJ TI AEROSOL OPTICAL-PROPERTIES AT MAUNA-LOA OBSERVATORY - LONG-RANGE TRANSPORT FROM KUWAIT SO GEOPHYSICAL RESEARCH LETTERS LA English DT Article ID ABSORPTION-COEFFICIENT; TRANSMISSION; TRAJECTORIES; CLIMATOLOGY; COMPONENT; HAWAII AB Aerosol light absorption has been measured continuously at Mauna Loa Observatory, Hawaii (MLO), since April 1990. During the spring of 1991, after oil wells were fired in Kuwait, there was speculation among scientists concerning long-range transport of smoke particles and its possible effect on global climate. The MLO light absorption record from April 1990 to June 1991 shows low values in the 0.1-1 x 10(-7) m-1 range in the summer of 1990, and an increased baseline level of about 2-4 x 10(-7) m-1 with numerous superimposed events in the 5-10 x 10(-7) m-1 range in the spring of 1991. These levels correspond to black carbon (BC) concentrations of 1-10, 20-40, and 50-100 ng m-3, respectively, under the assumption that BC is the dominant light absorbing species and has a specific absorption of 10 m2 g-1. Large-scale 500-hPa trajectories calculated backwards from MLO sometimes show direct transport paths from China and Kuwait to Hawaii that coincide with the black carbon events. These measurements set an upper limit on the possible contribution of Kuwaiti black carbon to the background troposphere near MLO during periods of rapid transport. The aerosol observed at MLO is expected to cause a net cooling of the atmosphere. RP BODHAINE, BA (reprint author), NOAA,CLIMATE MONITORING & DIAGNOST LAB,RECG1,325 BROADWAY,BOULDER,CO 80303, USA. RI Ogren, John/M-8255-2015 OI Ogren, John/0000-0002-7895-9583 NR 21 TC 29 Z9 29 U1 0 U2 3 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 MAR 20 PY 1992 VL 19 IS 6 BP 581 EP 584 DI 10.1029/92GL00524 PG 4 WC Geosciences, Multidisciplinary SC Geology GA HK981 UT WOS:A1992HK98100015 ER PT J AU EPLER, KS SANDER, LC ZIEGLER, RG WISE, SA CRAFT, NE AF EPLER, KS SANDER, LC ZIEGLER, RG WISE, SA CRAFT, NE TI EVALUATION OF REVERSED-PHASE LIQUID-CHROMATOGRAPHIC COLUMNS FOR RECOVERY AND SELECTIVITY OF SELECTED CAROTENOIDS SO JOURNAL OF CHROMATOGRAPHY LA English DT Article ID GRADIENT ELUTION TECHNIQUE; FATTY-ACID ESTERS; BETA-CAROTENE; ALPHA-TOCOPHEROL; HPLC DETERMINATION; SERUM RETINOL; HUMAN-PLASMA; VITAMIN-A; INTERNAL STANDARD; PAPRIKA PIGMENTS AB Sixty commercially available and five experimental liquid chromatography columns were evaluated for the separation and recovery of seven carotenoid compounds. Methanol- and acetonitrile-based solvents (either straight or modified with ethyl acetate or tetrahydrofuran) were compared to determine which solvent systems and which columns provided better selectivity and recovery. Methanol-based solvents typically provided higher recoveries than did acetonitrile-based solvents. Polymeric C-18 phases generally provided better selectivity for the difficult separation of lutein and zeaxanthin than did monomeric C-18 phases. C1 NATL INST STAND & TECHNOL,DIV ORGAN ANALYT RES,CHEM SCI & TECHNOL LAB,GAITHERSBURG,MD 20899. NCI,ENVIRONM EPIDEMIOL BRANCH,DIV CANC ETIOL,EPIDEMIOL & BIOSTAT PROGRAM,BETHESDA,MD 20892. FU NCI NIH HHS [Y01-CP9-0513] NR 58 TC 102 Z9 106 U1 1 U2 6 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0021-9673 J9 J CHROMATOGR PD MAR 20 PY 1992 VL 595 IS 1-2 BP 89 EP 101 DI 10.1016/0021-9673(92)85149-N PG 13 WC Chemistry, Analytical SC Chemistry GA HM930 UT WOS:A1992HM93000006 PM 1577914 ER PT J AU RANDALL, DA CESS, RD BLANCHET, JP BOER, GJ DAZLICH, DA DELGENIO, AD DEQUE, M DYMNIKOV, V GALIN, V GHAN, SJ LACIS, AA LETREUT, H LI, ZX LIANG, XZ MCAVANEY, BJ MELESHKO, VP MITCHELL, JFB MORCRETTE, JJ POTTER, GL RIKUS, L ROECKNER, E ROYER, JF SCHLESE, U SHEININ, DA SLINGO, J SOKOLOV, AP TAYLOR, KE WASHINGTON, WM WETHERALD, RT YAGAI, I ZHANG, MH AF RANDALL, DA CESS, RD BLANCHET, JP BOER, GJ DAZLICH, DA DELGENIO, AD DEQUE, M DYMNIKOV, V GALIN, V GHAN, SJ LACIS, AA LETREUT, H LI, ZX LIANG, XZ MCAVANEY, BJ MELESHKO, VP MITCHELL, JFB MORCRETTE, JJ POTTER, GL RIKUS, L ROECKNER, E ROYER, JF SCHLESE, U SHEININ, DA SLINGO, J SOKOLOV, AP TAYLOR, KE WASHINGTON, WM WETHERALD, RT YAGAI, I ZHANG, MH TI INTERCOMPARISON AND INTERPRETATION OF SURFACE-ENERGY FLUXES IN ATMOSPHERIC GENERAL-CIRCULATION MODELS SO JOURNAL OF GEOPHYSICAL RESEARCH-ATMOSPHERES LA English DT Article ID CLIMATE FEEDBACK; CLOUD AB We have analyzed responses of the surface energy budgets and hydrologic cycles of 19 atmospheric general circulation models to an imposed, globally uniform sea surface temperature perturbation of 4 K. The responses of the simulated surface energy budgets are extremely diverse and are closely linked to the responses of the simulated hydrologic cycles. The response of the net surface energy flux is not controlled by cloud effects; instead, it is determined primarily by the response of the latent heat flux. The prescribed warming of the oceans leads to major increases in the atmospheric water vapor content and the rates of evaporation and precipitation. The increased water vapor amount drastically increases the downwelling infrared radiation at the Earth's surface, but the amount of the change varies dramatically from one model to another. C1 DEPT ENVIRONM, CANADIAN CLIMATE CTR, ATMOSPHER ENVIRONM SERV, 4905 DUFFERIN ST, TORONTO M3H 5T4, ONTARIO, CANADA. COLORADO STATE UNIV, DEPT ATMOSPHER SCI, FT COLLINS, CO 80523 USA. SUNY STONY BROOK, INST TERR & PLANETARY ATMOSPHERES, STONY BROOK, NY 11794 USA. NASA, GODDARD INST SPACE STUDIES, NEW YORK, NY 10025 USA. CTR NATL RECH METEOROL, DIRECT METEOROL, TOULOUSE, FRANCE. ACAD SCI USSR, DEPT NUMER MATH, MOSCOW V-71, USSR. UNIV CALIF LAWRENCE LIVERMORE NATL LAB, PROGRAM CLIMATE MODEL DIAG & INTERCOMPARISON, LIVERMORE, CA 94550 USA. LAB METEOROL DYNAM, PARIS, FRANCE. SUNY STONY BROOK, DEPT MECH ENGN, STONY BROOK, NY 11794 USA. BUR METEOROL RES CTR, MELBOURNE, VIC, AUSTRALIA. VOEIKOV MAIN GEOPHYS OBSERV, ST PETERSBURG, USSR. METEOROL OFF, BRACKNELL, BERKS, ENGLAND. EUROPEAN CTR MEDIUM RANGE WEATHER FORECASTS, READING, BERKS, ENGLAND. PRINCETON UNIV, NOAA, GEOPHYS FLUID DYNAM LAB, PRINCETON, NJ 08544 USA. METEOROL RES INST, IBARAKI, JAPAN. UNIV HAMBURG, INST METEOROL, W-2000 HAMBURG 13, GERMANY. UNIV READING, DEPT METEOROL, READING RG6 2AH, BERKS, ENGLAND. NATL CTR ATMOSPHER RES, DIV CLIMATE & GLOBAL DYNAM, BOULDER, CO 80307 USA. RI Taylor, Karl/F-7290-2011; Del Genio, Anthony/D-4663-2012; Lacis, Andrew/D-4658-2012; Randall, David/E-6113-2011; Meleshko, Valentin/D-2157-2016; Ghan, Steven/H-4301-2011; OI Taylor, Karl/0000-0002-6491-2135; Del Genio, Anthony/0000-0001-7450-1359; Randall, David/0000-0001-6935-4112; Ghan, Steven/0000-0001-8355-8699; Li, Laurent/0000-0002-3855-3976 NR 23 TC 79 Z9 79 U1 0 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 MAR 20 PY 1992 VL 97 IS D4 BP 3711 EP 3724 PG 14 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA HK021 UT WOS:A1992HK02100002 ER PT J AU MAULDIN, RL BURKHOLDER, JB RAVISHANKARA, AR AF MAULDIN, RL BURKHOLDER, JB RAVISHANKARA, AR TI A PHOTOCHEMICAL, THERMODYNAMIC, AND KINETIC-STUDY OF CLOO SO JOURNAL OF PHYSICAL CHEMISTRY LA English DT Article ID SELF-REACTION; CHLORINE; OZONE; PHOTOLYSIS; ANTARCTICA; RADICALS; OXYGEN AB The relative absorption cross sections for the ClOO radical were measured in the region 220-280 nm. The absolute UV absorption cross section at 246.0 nm, the peak of the absorption, was determined to be (2.98 +/- 0.23) x 10(-17) cm2 molecule-1. Using this value, the cross sections in the 220-280-nm range were calculated. The equilibrium constant for the Cl + O2 reversible ClOO reaction was measured at six temperatures between 191 and 250 K. A third law analysis of these measured equilibrium constants yields a value of -5.1 kcal mol-1 for DELTA-degrees-H(r233) or -4.6 kcal mol-1 for DELTA-degrees-H(r0) The removal of ClOO in the above temperature range was found to occur via the reaction Cl + ClOO --> products. The rate coefficient for this reaction was measured to be (2.15 +/- 0.13) x 10(-10) cm3 molecule-1 s-1, independent of temperature. C1 NOAA,AERON LAB,BOULDER,CO 80303. UNIV COLORADO,DEPT CHEM & BIOCHEM,BOULDER,CO 80309. UNIV COLORADO,NOAA,COOPERAT INST RES ENVIRONM SCI,BOULDER,CO 80309. RI Ravishankara, Akkihebbal/A-2914-2011 NR 27 TC 51 Z9 51 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 MAR 19 PY 1992 VL 96 IS 6 BP 2582 EP 2588 DI 10.1021/j100185a035 PG 7 WC Chemistry, Physical SC Chemistry GA HK717 UT WOS:A1992HK71700035 ER PT J AU HANSON, DR RAVISHANKARA, AR AF HANSON, DR RAVISHANKARA, AR TI INVESTIGATION OF THE REACTIVE AND NONREACTIVE PROCESSES INVOLVING CLONO2 AND HCL ON WATER AND NITRIC-ACID DOPED ICE SO JOURNAL OF PHYSICAL CHEMISTRY LA English DT Article ID ANTARCTIC OZONE DEPLETION; POLAR STRATOSPHERIC CLOUD; HETEROGENEOUS REACTIONS; HYDROGEN-CHLORIDE; TRIHYDRATE; CHEMISTRY; SURFACES; N2O5; KINETICS; NITRATE AB A flow tube reactor attached to a chemical ionization mass spectrometer was used to investigate the reactions of ClONO2 with H2O and HCl on pure water ice and nitric acid doped ice (referred to as NAT). The uptake coefficients, gamma, for the above reactions were found to be nearly independent of the ice substrate thickness, suggesting that the geometrical surface areas of our ices are close to the true surface areas for such reactions. At low concentrations of HCl, close to those found in the atmosphere, its uptake due to physical adsorption was found to be very rapid, i.e., gamma > 0.3; however it slowed considerably when a monolayer of HCl had been deposited on the surface. The surface of both water and NAT ice are shown to be saturated with HCl after the formation of a monolayer, suggesting that reactions involving HCl are confined to the surface. At high HCl concentrations the surface was altered by the formation of a hydrate or melting. The reaction of ClONO2 with H2O on pure ice was found to generate HOCl, which has an appreciable adsorptivity on the surface. The direct uptake of HOCl on water ice was observed and its adsorptivity was found to decrease at warmer temperatures. A direct reaction between HOCl and HCl to produce Cl2 on both pure ice and a NAT surface was observed. It is proposed that the reaction of ClONO2 with HCl on water ice can proceed through the formation of HOCl and its subsequent reaction with HCl to give Cl2, while the reaction is direct on HNO3-doped ice. The implication of these findings to the surface reactions in the atmosphere are discussed. C1 UNIV COLORADO,NOAA,COOPERAT INST RES ENVIRONM SCI,BOULDER,CO 80309. UNIV COLORADO,DEPT CHEM & BIOCHEM,BOULDER,CO 80309. RP HANSON, DR (reprint author), NOAA,AERON LAB,325 BROADWAY,BOULDER,CO 80303, USA. RI Ravishankara, Akkihebbal/A-2914-2011 NR 29 TC 254 Z9 254 U1 1 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 MAR 19 PY 1992 VL 96 IS 6 BP 2682 EP 2691 DI 10.1021/j100185a052 PG 10 WC Chemistry, Physical SC Chemistry GA HK717 UT WOS:A1992HK71700052 ER PT J AU SIKORA, M BEGELMAN, MC AF SIKORA, M BEGELMAN, MC TI DOES AN ORBITING STAR CAUSE PERIODIC MODULATION OF X-RAYS FROM NGC6814 SO NATURE LA English DT Article ID BLACK-HOLES AB USING data from the Ginga satellite, Done et al. 1 have confirmed an Exosat observation 2 of high-amplitude periodic modulation in the X-ray emission from the Seyfert galaxy NGC6814. To within observational errors of approximately 1%, the period seems to have remained constant at approximately 12,100 seconds between 1985 and 1989. An obvious candidate for the phenomenon underlying the periodicity is the orbital motion of a star or low-mass compact object around the central black hole 3. As we show here, the presence of an orbiting star could be verified easily by looking for the effects of Lense-Thirring precession of the orbital plane, caused by the dragging of inertial frames around a rotating black hole. Precession-induced variations in the waveform and in the phase of the observed periodicity should have a period of between a month and a year. Such variations could account for the different waveforms present in the Ginga and Exosat data sets 4, and may be detectable in existing Ginga and future Rosat, OSSE/GRO, and Astro-D data. C1 UNIV COLORADO,DEPT ASTROPHYS PLANETARY & ATMOSPHER SCI,BOULDER,CO 80309. RP SIKORA, M (reprint author), UNIV COLORADO,NATL INST STAND & TECHNOL,JOINT INST LAB ASTROPHYS,BOULDER,CO 80309, USA. NR 13 TC 12 Z9 12 U1 0 U2 0 PU MACMILLAN MAGAZINES LTD PI LONDON PA PORTERS SOUTH, 4 CRINAN ST, LONDON, ENGLAND N1 9XW SN 0028-0836 J9 NATURE JI Nature PD MAR 19 PY 1992 VL 356 IS 6366 BP 224 EP 225 DI 10.1038/356224a0 PG 2 WC Multidisciplinary Sciences SC Science & Technology - Other Topics GA HJ944 UT WOS:A1992HJ94400050 ER PT J AU NYDEN, MR FORNEY, GP BROWN, JE AF NYDEN, MR FORNEY, GP BROWN, JE TI MOLECULAR MODELING OF POLYMER FLAMMABILITY - APPLICATION TO THE DESIGN OF FLAME-RESISTANT POLYETHYLENE SO MACROMOLECULES LA English DT Article ID DYNAMICS; SIMULATION AB Molecular dynamic simulations of the thermal degradation of polyethylene were used to identify factors which might be effective in reducing polymer flammability by promoting the formation of a residual char. Computer movies of the calculated trajectories indicate that cross-linked polymers, such as those obtained from exposure of polyethylene to ionizing radiation, will undergo further cross-linking when burned, eventually forming a high molecular weight, thermally stable char. This prediction was confirmed in flammability tests of gamma-ray-irradiated polyethylene. RP NYDEN, MR (reprint author), NATL INST STAND & TECHNOL,BLDG & FIRE RES LAB,GAITHERSBURG,MD 20899, USA. NR 25 TC 44 Z9 44 U1 0 U2 7 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 0024-9297 J9 MACROMOLECULES JI Macromolecules PD MAR 16 PY 1992 VL 25 IS 6 BP 1658 EP 1666 DI 10.1021/ma00032a007 PG 9 WC Polymer Science SC Polymer Science GA HJ861 UT WOS:A1992HJ86100007 ER PT J AU BECKERLE, JD CASASSA, MP CAVANAGH, RR HEILWEIL, EJ STEPHENSON, JC AF BECKERLE, JD CASASSA, MP CAVANAGH, RR HEILWEIL, EJ STEPHENSON, JC TI SUBPICOSECOND TIME-RESOLVED IR SPECTROSCOPY OF THE VIBRATIONAL DYNAMICS OF RH(CO)2(ACAC) SO CHEMICAL PHYSICS LA English DT Article ID POPULATION LIFETIMES AB Sub-picosecond pulses are used to measure the transient IR spectra of vibrationally excited Rh(CO)2(acac) in dilute solutions of n-hexane and CCl3H. Ground-state bleach and excited-state absorption features are observed at t(D) > 0, while interference-like spectra characteristic of the perturbed free induction decay (FID) of the probe polarization are seen at t(D) < 0. At t(D) > 0, the bleach signal exhibits an initial decay (n-hexane, 3-6 ps; CCl3H, 2.2-4 ps) attributed to rapid v-v coupling between the symmetric and asymmetric stretch modes of the dicarbonyl, followed by much slower (n-hexane, 61 ps; CCl3H, 101 ps) population relaxation. Calculated transient spectra and bleach decay curves obtained from a 5-level density matrix model of the coupled CO oscillators account for the data, including the effects due to perturbed FID and the rapid v-v coupling. C1 NATL INST STAND & TECHNOL, GAITHERSBURG, MD 20899 USA. NR 19 TC 54 Z9 55 U1 0 U2 15 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0301-0104 EI 1873-4421 J9 CHEM PHYS JI Chem. Phys. PD MAR 15 PY 1992 VL 160 IS 3 BP 487 EP 497 DI 10.1016/0301-0104(92)80015-N PG 11 WC Chemistry, Physical; Physics, Atomic, Molecular & Chemical SC Chemistry; Physics GA HH324 UT WOS:A1992HH32400015 ER PT J AU JOHNSON, RD AF JOHNSON, RD TI CCL RYDBERG STATES SO JOURNAL OF CHEMICAL PHYSICS LA English DT Article ID ELECTRONIC-SPECTRUM; SPECTROSCOPY; DISCHARGE; RADICALS AB CCl radical has been observed from 280 to 410 nm by resonance enhanced multiphoton ionization (REMPI) spectroscopy. Transitions from the ground state to Rydberg states are observed in the range of 40 000-70 000 cm-1, and to the previously known A (2)DELTA state at 36 000 cm-1. The states display short vibrational progressions with spacings of 1100 cm-1, which is similar to the ion vibrational frequency. Vibrational progressions are observed in a number of Rydberg states and the origins are assigned by isotope shifts and hot band analysis. From two of these Rydberg states an ionization potential is estimated to be 8.83 +/- 0.01 eV. RP JOHNSON, RD (reprint author), NATL INST STAND & TECHNOL,DIV CHEM KINET & THERMODYNAM,GAITHERSBURG,MD 20899, USA. NR 25 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 0021-9606 J9 J CHEM PHYS JI J. Chem. Phys. PD MAR 15 PY 1992 VL 96 IS 6 BP 4073 EP 4078 DI 10.1063/1.461862 PG 6 WC Chemistry, Physical; Physics, Atomic, Molecular & Chemical SC Chemistry; Physics GA HK019 UT WOS:A1992HK01900003 ER PT J AU TSANG, W HERRON, JT AF TSANG, W HERRON, JT TI KINETICS AND THERMODYNAMICS OF THE REACTION SF6-REVERSIBLE-SF5+F SO JOURNAL OF CHEMICAL PHYSICS LA English DT Article ID SULFUR-HEXAFLUORIDE; GAS-PHASE; CHEMISTRY; SF6; DECOMPOSITION; MOLECULES; D(SF5-F); RADICALS; S2F10; TUBE AB A reanalysis of most of the existing data bearing on the strength of the S-F bond in SF6 does not support the generally accepted value of BDE(SF5-F) = 390.8 +/- 15.1 kJ mol-1 at 298 K. Instead, a new value of BDE(SF5-F) = 420 +/- 10 kJ mol-1 at 298 K is shown to be compatible with all the existing data. This conclusion is based on a critical examination of earlier shock-tube data on the thermal decomposition of SF6, recent measurements of the rate constant for the reverse reaction, F + SF5, various experiments on ion thermodynamics and photoionization energetics, and studies of the chemiluminescent reactions of Ca and Sr atoms. As a consequence of the present analysis, we find that the rate expressions for SF6 decomposition and the reverse combination rate expressions (at the high pressure limit) are k(SF6 --> SF5 + F) = 1.7 x 10(22)(1/T)1.9 exp( - 50 800/T)s-1, k(SF5 + F --> SF6) = 1 x 10(-11)(T/300)-1 cm3 molecule-1 s-1 and the step-size down for collisions of argon with SF6, in the temperature range 1700-2000 K, is about 400 cm-1. We are also able to derive a new value for the appearance energy of SF5+ from SF6 of 14.0 eV, and a new value for DELTA(f)H(SF4) = - 746 +/- 12 kJ mol-1. RP TSANG, W (reprint author), NATL INST STAND & TECHNOL,DIV CHEM KINET & THERMODYNAM,GAITHERSBURG,MD 20899, USA. NR 35 TC 42 Z9 43 U1 0 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 MAR 15 PY 1992 VL 96 IS 6 BP 4272 EP 4282 DI 10.1063/1.462821 PG 11 WC Chemistry, Physical; Physics, Atomic, Molecular & Chemical SC Chemistry; Physics GA HK019 UT WOS:A1992HK01900025 ER PT J AU ROWLEY, RL ELY, JF AF ROWLEY, RL ELY, JF TI NOTE ON THE NUMBER DEPENDENCE OF NONEQUILIBRIUM MOLECULAR-DYNAMICS SIMULATIONS OF THE VISCOSITY OF STRUCTURED MOLECULES SO JOURNAL OF CHEMICAL PHYSICS LA English DT Note ID ALKANES C1 NATL INST STAND & TECHNOL,BOULDER,CO 80303. RP ROWLEY, RL (reprint author), BRIGHAM YOUNG UNIV,DEPT CHEM ENGN,PROVO,UT 84602, USA. NR 4 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 0021-9606 J9 J CHEM PHYS JI J. Chem. Phys. PD MAR 15 PY 1992 VL 96 IS 6 BP 4814 EP 4815 DI 10.1063/1.462770 PG 2 WC Chemistry, Physical; Physics, Atomic, Molecular & Chemical SC Chemistry; Physics GA HK019 UT WOS:A1992HK01900086 ER PT J AU MUSMAN, S AF MUSMAN, S TI GEOSAT ALTIMETER OBSERVATIONS OF LONG WAVES IN THE EQUATORIAL ATLANTIC SO JOURNAL OF GEOPHYSICAL RESEARCH-OCEANS LA English DT Article ID INSTABILITY WAVES; PACIFIC-OCEAN; CURRENTS; COUNTERCURRENT AB Geosat altimeter observations covering most of the equatorial Atlantic between March and November 1987 were examined. Six ground tracks were selected with equator crossings between 15-degrees-W and 23-degrees-W longitude. At these locations there is evidence of westward propagating long waves during four repeat passes between July and October. Best fit parameters are phase velocity of 45 +/- 6 cm s-1 and period of 25 +/- 2 days. Waves are likely present over a wider range in longitude, but the observations are restricted by scan lines intersecting Africa to the east and noise associated with geoid undulations near the mid-Atlantic ridge to the west. A composite mean wave pattern was constructed between 8-degrees-N and 8-degrees-S latitude. The pattern resembles a somewhat distorted free mode. There are two off-equatorial maxima of 3.3 +/- 1.0 cm near 4-degrees-N and 2.6 +/- 0.7 cm near 4-degrees-S latitude. The northern maxima has a distinct NW-SE tilt of about 30-degrees. This is direct evidence of the transport of energy from the mean zonal flow into the wave. The kinetic energy replacement time is about 17 days. For comparison, an example of a shear instability wave in a simple rotating system is shown with the same sort of tilt as well as a free mode without a tilt. RP MUSMAN, S (reprint author), NOAA,NATL OCEAN SERV,GEOSCI LAB,ROCKVILLE,MD 20852, USA. NR 22 TC 9 Z9 9 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 MAR 15 PY 1992 VL 97 IS C3 BP 3573 EP 3579 DI 10.1029/91JC02887 PG 7 WC Oceanography SC Oceanography GA HJ488 UT WOS:A1992HJ48800007 ER PT J AU MAY, DA STOWE, LL HAWKINS, JD MCCLAIN, EP AF MAY, DA STOWE, LL HAWKINS, JD MCCLAIN, EP TI A CORRECTION FOR SAHARAN DUST EFFECTS ON SATELLITE SEA-SURFACE TEMPERATURE-MEASUREMENTS SO JOURNAL OF GEOPHYSICAL RESEARCH-OCEANS LA English DT Article ID AVHRR DATA; AEROSOLS; CLOUD; OCEAN AB Sea surface temperature (SST) retrievals obtained from NOAA advanced very high resolution radiometer (AVHRR) data can determine SST within 0.7-degrees-C on a global basis. However, retrievals have been severely limited in the presence of tropospheric aerosol particles because no adequate aerosol correction algorithm exists. High tropospheric aerosol concentrations in the atmosphere significantly increase infrared signal attenuation and prevent the retrieval of accurate satellite SSTs. This paper presents tropospheric aerosol correction algorithms derived from NOAA AVHRR SST and optical depth measurements and from drifting buoy in situ SSTs. We show that the correction algorithms perform better than the current global algorithm in an atmosphere that contains high Saharan dust concentrations and generate statistical accuracy comparable to satellite SST performance globally. These corrections would significantly increase the quantity and quality of satellite retrievals under such atmospheric conditions, and the observations would greatly benefit both global climate research and maritime operations conducted in such regions. C1 NOAA,NATL ENVIRONM SATELLITE,SATELLITE RES LAB,CAMP SPRINGS,MD 20233. RP MAY, DA (reprint author), USN,OCEANOG & ATMOSPHER RES LAB,REMOTE SENSING BRANCH,BAY ST LOUIS,MS 39529, USA. NR 28 TC 38 Z9 38 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 MAR 15 PY 1992 VL 97 IS C3 BP 3611 EP 3619 DI 10.1029/91JC02987 PG 9 WC Oceanography SC Oceanography GA HJ488 UT WOS:A1992HJ48800010 ER PT J AU SARMIENTO, JL ORR, JC SIEGENTHALER, U AF SARMIENTO, JL ORR, JC SIEGENTHALER, U TI A PERTURBATION SIMULATION OF CO2 UPTAKE IN AN OCEAN GENERAL-CIRCULATION MODEL SO JOURNAL OF GEOPHYSICAL RESEARCH-OCEANS LA English DT Article ID CARBON-DIOXIDE EXCHANGE; APPARENT DISSOCIATION-CONSTANTS; PAST 2 CENTURIES; ATMOSPHERIC CO2; DIFFUSION-MODEL; WORLD OCEAN; ATLANTIC-OCEAN; INCREASE; SEAWATER; CLIMATE AB The uptake of anthropogenic CO2 by the ocean is simulated using a perturbation approach in a three-dimensional global general circulation model. Atmospheric pCO2 is prescribed for the period 1750-1990 using the combined Siple ice core and Mauna Loa records. For the period 1980 to 1989, the average flux of CO2 into the ocean is 1.9 GtC/yr. However the bomb radiocarbon simulation of Toggweiler et al. (1989b) shows that the surface to deep ocean exchange in this model is too sluggish. Hence the CO2 uptake calculated by the model is probably below the actual value. The observed atmospheric increase in 1980 to 1989 is 3.2 GtC/yr, for a combined atmosphere-ocean total of 5.1 GtC/yr. This is comparable to the estimated fossil CO2 production of 5.4 GtC/yr, implying that other sources and sinks (such as from deforestation, enhanced growth of land biota, and changes in the ocean carbon cycle) must be approximately in balance. The sensitivity of the uptake to the gas exchange rate is small: a 100% increase in gas exchange rate gives only a 9.2% increase in cumulative oceanic uptake. Details of the penetration into different oceanic regions are discussed. C1 UNIV BERN, INST PHYS, CH-3000 BERN, SWITZERLAND. RP SARMIENTO, JL (reprint author), PRINCETON UNIV, PROGRAM ATMOSPHER & OCEAN SCI, PRINCETON, NJ 08544 USA. RI Orr, James/C-5221-2009; OI Orr, James/0000-0002-8707-7080 NR 93 TC 249 Z9 258 U1 3 U2 24 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 MAR 15 PY 1992 VL 97 IS C3 BP 3621 EP 3645 DI 10.1029/91JC02849 PG 25 WC Oceanography SC Oceanography GA HJ488 UT WOS:A1992HJ48800011 ER PT J AU XU, Q AF XU, Q TI DENSITY CURRENTS IN SHEAR FLOWS - A 2-FLUID MODEL SO JOURNAL OF THE ATMOSPHERIC SCIENCES LA English DT Article ID GRAVITY CURRENT; HORIZONTAL SURFACE; SQUALL LINES; CONVECTION; HEAD; DYNAMICS; BOUNDARY AB This paper develops a two-fluid steady-state model of a density current and its front propagating into a uniformly sheared environmental flow. This model is used to examine the kinematic and dynamic factors that control the depth and propagation speed of the density current and the geometric shape of the density current front. For an idealized inviscid flow, the results show that the density current becomes deeper and propagates faster relative to the environmental flow as the shear increases toward positive (i.e., the system-relative inflow speed decreases with height). When the effects of energy loss and negative vorticity generation are taken into account for the entire or physically constrained fractional depth of the upper-layer outflow, multiple solutions are found for two possible flow states: supercritical and subcritical. similar to that of Benjamin. The supercritical (or subcritical) state is characterized by a large (small) Froude number for the downstream upper-layer outflow, in which case the density current is shallower (or much shallower) and propagates slightly faster (or significantly slower) than the idealized inviscid one. The depth and propagation speed of a density current of supercritical (or subcritical) state increase rapidly (or decrease very slowly) as the shear increases toward positive, but change very slightly (or significantly) with the energy loss and/or negative vorticity generation. Applications of the model results to real atmospheric density currents are also discussed. C1 NOAA,ENVIRONM RES LAB,NATL SEVERE STORMS LAB,NORMAN,OK 73069. RP XU, Q (reprint author), UNIV OKLAHOMA,COOPERAT INST MESOSCALE METEOROL,100 E BOYD,NORMAN,OK 73019, USA. NR 20 TC 53 Z9 53 U1 1 U2 4 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 MAR 15 PY 1992 VL 49 IS 6 BP 511 EP 524 DI 10.1175/1520-0469(1992)049<0511:DCISFA>2.0.CO;2 PG 14 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA HL081 UT WOS:A1992HL08100005 ER PT J AU COOK, KH HELD, IM AF COOK, KH HELD, IM TI THE STATIONARY RESPONSE TO LARGE-SCALE OROGRAPHY IN A GENERAL-CIRCULATION MODEL AND A LINEAR-MODEL SO JOURNAL OF THE ATMOSPHERIC SCIENCES LA English DT Article ID FORCED PLANETARY-WAVES; ATMOSPHERE; FLOW; GCM AB Stationary waves generated over orography in a linear model and a general circulation model (GCM) are compared to examine how the atmosphere's response is established for small mountains and how linear theory breaks down over large orographic features. Both models have nine vertical levels and are low-resolution (R15) spectral models. The linear model solves the stationary linear primitive equations. The GCM's control integration uses zonally uniform and hemispherically symmetric boundary conditions, with a global swamp surface. Five experiments are performed by perturbing the GCM with Gaussian mountains of various heights introduced in midlatitudes. The stationary wave model is linearized about zonal mean fields from the GCM climatology. The linear model's response to a Gaussian mountain at 45-degrees-N latitude is dominated by a single wave train radiating toward the southeast. For mountain heights between 0.7 and 2 km, the GCM's stationary waves are similar to the linear model response to orography, although amplitudes increase less rapidly than linearly with mountain height. For larger mountains, closed isentropes and distinctly nonlinear flow occur along the surface of the mountain and a large poleward-radiating wave train develops. The development of closed isentropes, and the breakdown of linear theory, can be predicted whenever the slope of the surface exceeds the slope of the isentropes in the unperturbed (no mountain) basic state. C1 NOAA,GEOPHYS FLUID DYNAM LAB,PRINCETON,NJ. RI Cook, Kerry/B-4998-2011 NR 18 TC 43 Z9 43 U1 1 U2 6 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 MAR 15 PY 1992 VL 49 IS 6 BP 525 EP 539 DI 10.1175/1520-0469(1992)049<0525:TSRTLS>2.0.CO;2 PG 15 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA HL081 UT WOS:A1992HL08100006 ER PT J AU MOUNTAIN, RD THIRUMALAI, D AF MOUNTAIN, RD THIRUMALAI, D TI ERGODICITY AND ACTIVATED DYNAMICS IN SUPERCOOLED LIQUIDS SO PHYSICAL REVIEW A LA English DT Note ID ANISOTROPIC CORRELATIONS; MOLECULAR-DYNAMICS; SOFT SPHERES; GLASSY; CONVERGENCE; RELAXATION; STATES AB We show, using constant-pressure molecular-dynamics calculations, that the deviation from Arrhenius behavior in transport properties in the supercooled states of Lennard-Jones (LJ) fluids and soft-sphere (SS) systems starts to occur when the time scale for obtaining ergodicity starts to increase dramatically. The temperature dependence of the ergodicity diffusion parameter for both the SS mixtures and the two-component LJ system follows the Vogel-Fulcher (VF) equation. The self-diffusion constants for the SS mixtures follows the Arrhenius law, whereas for the LJ system a VF behavior is found. Our results also demonstrate that relaxation processes in supercooled liquids are dominated by fluctuations in domains of finite length. C1 UNIV MARYLAND,INST PHYS SCI & TECHNOL,COLLEGE PK,MD 20742. RP MOUNTAIN, RD (reprint author), NATL INST STAND & TECHNOL,DIV THERMOPHYS,GAITHERSBURG,MD 20899, USA. NR 22 TC 18 Z9 18 U1 2 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 MAR 15 PY 1992 VL 45 IS 6 BP R3380 EP R3383 PG 4 WC Optics; Physics, Atomic, Molecular & Chemical SC Optics; Physics GA HK384 UT WOS:A1992HK38400004 ER PT J AU APELL, SP PENN, DR AF APELL, SP PENN, DR TI PHOTOINDUCED RESONANT TUNNELING TREATED BY AN EXTENDED TRANSFER HAMILTONIAN METHOD SO PHYSICAL REVIEW B LA English DT Article ID DOUBLE-BARRIER DIODES; QUANTUM WELL; FREQUENCY LIMIT; TIME; OSCILLATORS; MICROSCOPY; TRANSISTOR; RESISTANCE; SCATTERING; VOLTAGE AB A method, originally due to Heitler, is utilized to extend the transfer Hamiltonian description to resonant tunneling for the purpose of calculating transition probabilities and general frequency response characteristics of coupled systems. The scanning tunneling microscope (STM) is treated as an example of a single barrier and an irradiated quantum well as an example of a double barrier. The saturation of the contact resistance in the STM is easily derived and a simple physical explanation for the high-frequency response of an irradiated double junction is presented. In the latter case, it is found that the cutoff in the frequency response for high frequencies is limited by the optical properties of the outer electrodes of the double barrier. C1 NATL INST STAND & TECHNOL,ELECTRON PHYS GRP,GAITHERSBURG,MD 20899. RP APELL, SP (reprint author), CHALMERS UNIV TECHNOL,INST THEORET PHYS,S-41296 GOTHENBURG,SWEDEN. NR 43 TC 17 Z9 17 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 MAR 15 PY 1992 VL 45 IS 12 BP 6757 EP 6768 DI 10.1103/PhysRevB.45.6757 PG 12 WC Physics, Condensed Matter SC Physics GA HL049 UT WOS:A1992HL04900039 ER PT J AU HERZBERG, O REDDY, P SUTRINA, S SAIER, MH REIZER, J KAPADIA, G AF HERZBERG, O REDDY, P SUTRINA, S SAIER, MH REIZER, J KAPADIA, G TI STRUCTURE OF THE HISTIDINE-CONTAINING PHOSPHOCARRIER PROTEIN HPR FROM BACILLUS-SUBTILIS AT 2.0-A RESOLUTION SO PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF THE UNITED STATES OF AMERICA LA English DT Article ID SUGAR PHOSPHOTRANSFERASE SYSTEM; GRAM-POSITIVE BACTERIA; MACROMOLECULAR CRYSTALLOGRAPHY; TERTIARY STRUCTURE; ESCHERICHIA-COLI; PHOSPHOENOLPYRUVATE; PHOSPHORYLATION; REFINEMENT; RESONANCE; SECONDARY AB The crystal structure of the histidine-containing phosphocarrier protein (HPr) of the phosphoenolpyruvate:sugar phosphotransferase system (PTS) from Bacillus subtilis has been determined at 2.0-angstrom resolution and refined to a crystallographic residual error R-factor of 0.150. The secondary-structure folding topology of the molecule is that of an open-face beta-sandwich formed by four antiparallel beta-strands packed against three alpha-helices. The active-site histidine, His-15, caps the N terminus of the first helix, suggesting that the helix dipole plays a role in stabilizing the phosphorylated state of the histidine. A sulfate anion located between His-15 and the neighboring Arg-17 has been identified in the electron-density map. Association of this negatively charged species with the two key catalytic residues implies that the crystal structure resembles the phosphorylated state of the protein. A model of the phosphorylated form of the molecule is proposed, in which the negatively charged phosphoryl group interacts with two main-chain nitrogen atoms of the following helix and with the guanidinium group of Arg-17. It is also proposed that the phosphoryl transfer from HPr to the IIA domain of the glucose permease involves Arg-17 switching between two salt bridges: one with the phosphorylated histidyl of HPr and the other with two aspartyl residues associated with the active site of the IIA domain of glucose permease, which are accessible upon complex formation. C1 NATL INST STAND & TECHNOL,CTR ADV RES BIOTECHNOL,ROCKVILLE,MD 20850. UNIV CALIF SAN DIEGO,DEPT BIOL,LA JOLLA,CA 92093. RP HERZBERG, O (reprint author), UNIV MARYLAND,MARYLAND BIOTECHNOL INST,9600 GUDELSKY DR,ROCKVILLE,MD 20850, USA. FU NIAID NIH HHS [R01-AI14176, R01-AI21702] NR 34 TC 127 Z9 129 U1 2 U2 2 PU NATL ACAD PRESS 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 MAR 15 PY 1992 VL 89 IS 6 BP 2499 EP 2503 DI 10.1073/pnas.89.6.2499 PG 5 WC Multidisciplinary Sciences SC Science & Technology - Other Topics GA HJ053 UT WOS:A1992HJ05300104 PM 1549615 ER PT J AU MORASSUTTI, MP AF MORASSUTTI, MP TI COMPONENT REFLECTANCE SCHEME FOR DMSP-DERIVED SEA ICE REFLECTANCES IN THE ARCTIC BASIN SO INTERNATIONAL JOURNAL OF REMOTE SENSING LA English DT Article ID SURFACE ALBEDO; THERMODYNAMIC MODEL; SPECTRAL ALBEDO; SEASONAL CYCLE; CLIMATE; SNOW; GROWTH AB A scheme is introduced which in effect 'splits' Defence Meteorological Satellite Program (DMSP) single broadband sea ice reflectances into weighted visible and near-infrared (NIR) component reflectances. The method is rooted in (1) the fitting of polynomials to observed spectral reflectance curves of sea ice, (2) a weighting scheme and (3) the identification of general sea ice types and their corresponding areal coverage per imaged cell. Previously derived DMSP broadband sea ice reflectances in the Arctic Basin have been spectrally sequestered into visible and NIR component reflectances for May to August for the years 1977, 1979, 1984 and 1985. Comparison of spectrally modified DMSP visible reflectances (0.4-0.9-mu-m) are in closer agreement with NOAA-5 derived visible sea ice reflectances (0.52-0.72-mu-m) than unmodified DMSP visible/NIR reflectances (0.4-1.1-mu-m) for July 1977 in the Arctic Basin. It was also found that melt pond and flooding effects were more apparent for spectrally-modified NIR reflectances as compared to spectrally-modified visible reflectances. Possible uses of the scheme and newly created data sets are discussed. C1 UNIV COLORADO,NOAA,COOPERAT INST RES ENVIRONM SCI,BOULDER,CO 80309. NR 37 TC 3 Z9 3 U1 0 U2 0 PU TAYLOR & FRANCIS LTD PI LONDON PA ONE GUNDPOWDER SQUARE, LONDON, ENGLAND EC4A 3DE SN 0143-1161 J9 INT J REMOTE SENS JI Int. J. Remote Sens. PD MAR 10 PY 1992 VL 13 IS 4 BP 647 EP 662 PG 16 WC Remote Sensing; Imaging Science & Photographic Technology SC Remote Sensing; Imaging Science & Photographic Technology GA HG845 UT WOS:A1992HG84500006 ER PT J AU MCADOO, DC MARKS, KM AF MCADOO, DC MARKS, KM TI GRAVITY FIELDS OF THE SOUTHERN-OCEAN FROM GEOSAT DATA SO JOURNAL OF GEOPHYSICAL RESEARCH-SOLID EARTH LA English DT Article ID EXACT REPEAT MISSION; SEASAT ALTIMETER DATA; MANTLE CONVECTION; PACIFIC AB In August 1990, the U.S. Navy declassified all Geodetic Mission (GM) radar altimeter data acquired by the Geosat satellite over oceanic regions south of 60-degrees-S. We have used these GM data in conjunction with the unclassified, lower-resolution Geosat Exact Repeat Mission (ERM) altimeter data to construct high-resolution gravity fields on a 5-km grid covering the annular region of the southern ocean, which lies between 60-degrees-S and 72-degrees-S and encircles Antarctica. During the GM a complete mapping of the marine geoid (between 72-degrees-S and 72-degrees-N) was accomplished. The GM produced more densely spaced ground tracks (typically 2 or 3 km at 60-degrees-S) than those of either the ERM or Seasat. Consequently, we were able to use the GM data to map the marine gravity field at a higher resolution than was previously possible using satellite altimeter data. This paper describes the techniques we used to derive these gravity fields and image them. These techniques involve (1) computing along-track sea surface height slopes, (2) gridding of these ascending and descending slopes, (3) converting the slopes to conventional deflections of the vertical, (4) transforming the deflections to gravity anomalies in the frequency domain, and (5) imaging. The resulting images of the marine gravity field reveal much that is new about the seafloor and the tectonic fabric of the southern ocean: a region which includes large expanses of seafloor that have never been surveyed by ships. RP MCADOO, DC (reprint author), NOAA,NATL OCEAN SERV,GEOSCI LAB,ROCKVILLE,MD 20852, USA. RI Marks, Karen/F-5610-2010; McAdoo, Dave/F-5612-2010 OI Marks, Karen/0000-0001-6524-1495; McAdoo, Dave/0000-0002-7533-5564 NR 32 TC 67 Z9 68 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-SOL EA JI J. Geophys. Res.-Solid Earth PD MAR 10 PY 1992 VL 97 IS B3 BP 3247 EP 3260 DI 10.1029/91JB02797 PG 14 WC Geochemistry & Geophysics SC Geochemistry & Geophysics GA HG748 UT WOS:A1992HG74800002 ER PT J AU MADER, GL AF MADER, GL TI RAPID STATIC AND KINEMATIC GLOBAL POSITIONING SYSTEM SOLUTIONS USING THE AMBIGUITY FUNCTION TECHNIQUE SO JOURNAL OF GEOPHYSICAL RESEARCH-SOLID EARTH LA English DT Article AB This paper describes an ambiguity function technique by which phase data from the Global Positioning System (GPS) may be used to obtain survey positions for monuments occupied using a suitable GPS receiver. The principal benefit of the technique is the speed with which it may be used and its immunity to cycle slips or other discontinuities in the phase data that commonly occur. The technique uses phase measurements from satellites at both L1 and L2 frequencies from various directions in the sky. When sufficient measurements are available, the signals will destructively interfere at all but the correct location. Depending on the satellite geometry, the number of satellites in view, and the a priori knowledge of the station's position, a sufficient number of measurements may be obtained from a single monument occupation. The data collected over an occupation lasting only a few minutes may be averaged to a single value at a particular epoch. Equivalently, the data collected at only a single epoch may also be used. The ability of the technique to work with data from a single epoch allows the integer ambiguities on moving platforms to also be determined. This will greatly enhance the practical operation of kinematic GPS for a variety of remote sensing applications. A computer program employing this ambiguity function technique has been written and used to process static as well as kinematic data. The results indicate horizontal precisions and accuracies of 1 cm or better and vertical precisions and accuracies of 1 to 3 cm. The data processing requires no data editing, is easy to use, and can be operated without any specialized knowledge of kinematic GPS techniques. The correction for the effects of the ionosphere are also demonstrated at distances up to 250 km. The use of the ambiguity function for geophysical monitoring and kinematic remote sensing applications appears limited in distance only by the accuracy of the GPS orbits. The utility of the ambiguity function for rapid static surveying and on-the-fly bias fixing out to distances of several hundred kilometers appears practical. RP MADER, GL (reprint author), NOAA,NATL OCEAN SERV,OFF OCEAN & EARTH SCI,GEOSCI LAB,11400 ROCKVILLE PIKE,ROCKVILLE,MD 20852, USA. NR 12 TC 40 Z9 48 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-SOL EA JI J. Geophys. Res.-Solid Earth PD MAR 10 PY 1992 VL 97 IS B3 BP 3271 EP 3283 DI 10.1029/91JB02845 PG 13 WC Geochemistry & Geophysics SC Geochemistry & Geophysics GA HG748 UT WOS:A1992HG74800004 ER PT J AU BAKER, ET HAMMOND, SR AF BAKER, ET HAMMOND, SR TI HYDROTHERMAL VENTING AND THE APPARENT MAGMATIC BUDGET OF THE JUAN DE FUCA RIDGE SO JOURNAL OF GEOPHYSICAL RESEARCH-SOLID EARTH LA English DT Article ID EAST PACIFIC RISE; MID-ATLANTIC RIDGE; SEA MARC-I; AXIAL VOLCANO; NORTHEAST PACIFIC; SPREADING CENTERS; OCEAN RIDGE; GEOTHERMAL FIELDS; PROPAGATING RIFT; ENDEAVOR SEGMENT AB The fact that vigorous hydrothermal discharge occurs on ridge segments with a variety of spreading rates and morphological characteristics makes it difficult to discern the large-scale geological controls on the distribution of hydrothermal venting along the mid-ocean ridge. We undertook to simplify this problem by mapping the distribution of hydrothermally produced thermal and light attenuation anomalies along the crest of the Juan de Fuca Ridge, a medium-rate spreading center with segments of markedly differing morphology. Hydrothermal anomalies were detected by towing a high-precision conductivity-temperature-depth-transmissometer (CTDT) package in a sawtooth pattern through the lowermost 1000 m of the water column above each segment. These surveys, conducted between 1985 and 1989, have produced the first quantitative and continuous visualizations of hydrothermal plumes along a multisegment portion of the mid-ocean ridge. Hydrothermal discharge is strongest on those segments, or portions of segments, where the apparent magmatic budget is highest, as indicated by the degree of along-axis inflation and other morpbological characteristics. This correspondence implies that magma is episodically delivered in small and spatially discontinuous bodies of melt rather than by the constant resupply of a steady state magma chamber. We propose that the probability of discharge occurring at any point on the mid-ocean ridge is proportional to the spreading rate. This probability, scaled by the observation that significant plumes presently emanate from approximately 20% of the Juan de Fuca Ridge, is expected to range from approximately 5% on the slowest-spreading ridge to approximately 50% on the fastest-spreading ridge. C1 NOAA,PACIFIC MARINE ENVIRONM LAB,HATFIELD MARINE SCI CTR,NEWPORT,OR 97365. RP BAKER, ET (reprint author), NOAA,PACIFIC MARINE ENVIRONM LAB,7600 SAND POINT WAY NE,SEATTLE,WA 98115, USA. RI Wright, Dawn/A-4518-2011 OI Wright, Dawn/0000-0002-2997-7611 NR 62 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-SOL EA JI J. Geophys. Res.-Solid Earth PD MAR 10 PY 1992 VL 97 IS B3 BP 3443 EP 3456 DI 10.1029/91JB02671 PG 14 WC Geochemistry & Geophysics SC Geochemistry & Geophysics GA HG748 UT WOS:A1992HG74800016 ER PT J AU FEELY, RA MASSOTH, GJ BAKER, ET LEBON, GT GEISELMAN, TL AF FEELY, RA MASSOTH, GJ BAKER, ET LEBON, GT GEISELMAN, TL TI TRACKING THE DISPERSAL OF HYDROTHERMAL PLUMES FROM THE JUAN DE FUCA RIDGE USING SUSPENDED MATER COMPOSITION SO JOURNAL OF GEOPHYSICAL RESEARCH-SOLID EARTH LA English DT Article ID X-RAY-FLUORESCENCE; PARTICULATE MATTER; NORTHEAST PACIFIC; SULFIDE DEPOSITS; AXIAL VOLCANO; WATER-COLUMN; VENT FIELD; OCEAN; MANGANESE; PARTICLES AB In 1988 and 1989, particles from on- and off-axis neutrally buoyant plumes over the Juan de Fuca Ridge were sampled to study their changing composition with distance from the ridge crest. Plume depth and particle composition in off-axis hydrothermal plumes were used to identify plume sources and trajectories. Iron and phosphorus concentrations and, in particular, P/Fe molar ratios were found to be sensitive indicators of hydrothermal phases in the suspended matter. Phosphorus, vanadium, and arsenic are scavenged from solution where dissolved iron from hydrothermal vents oxidizes in seawater and forms submicrometer-sized particles of Fe oxyhydroxide. The P/Fe molar ratio (approximately 0.23) is essentially the same for vent fields along Cleft and Endeavour segments, indicating that the scavenging processes are the same for both regions. High P/Fe ratios are observed over the South and North Cleft Segment vent fields and to the west along the Vance Seamount Chain. The seamounts evidently function as a barrier, bathymetrically steering the hydrothermal plumes to the west away from the ridge crest. Since particles from the Endeavour vent field are greatly enriched in copper relative to hydrothermal plumes from other vent fields along the Juan de Fuca Rigde, copper concentrations in the plumes can be used to distinguish plume sources. Based on water column depth and elemental composition, hydrothermal plume particles from specific vent fields on the Juan de Fuca Ridge may be tracked as much as several tens of kilometers from their source using particle compositions. RP FEELY, RA (reprint author), NOAA,PACIFIC MARINE ENVIRONM LAB,7600 SAND POINT WAY NE,SEATTLE,WA 98115, USA. RI Wright, Dawn/A-4518-2011 OI Wright, Dawn/0000-0002-2997-7611 NR 53 TC 44 Z9 44 U1 0 U2 11 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 SN 0148-0227 J9 J GEOPHYS RES-SOL EA JI J. Geophys. Res.-Solid Earth PD MAR 10 PY 1992 VL 97 IS B3 BP 3457 EP 3468 DI 10.1029/91JB03062 PG 12 WC Geochemistry & Geophysics SC Geochemistry & Geophysics GA HG748 UT WOS:A1992HG74800017 ER PT J AU LIU, SX ZHANG, PH JI, XH JOHNSON, WW GILLILAND, GL ARMSTRONG, RN AF LIU, SX ZHANG, PH JI, XH JOHNSON, WW GILLILAND, GL ARMSTRONG, RN TI CONTRIBUTION OF TYROSINE-6 TO THE CATALYTIC MECHANISM OF ISOENZYME-3-3 OF GLUTATHIONE-S-TRANSFERASE SO JOURNAL OF BIOLOGICAL CHEMISTRY LA English DT Note ID ACTIVE-SITE; RAT-LIVER; ANION AB The role of the hydroxyl group of tyrosine 6 in the catalytic mechanism of isoenzyme 3-3 of rat glutathione S-transferase has been examined by x-ray crystallography and site-specific replacement of the residue with phenylalanine and evaluation of the catalytic properties of the mutant enzyme. This particular tyrosine residue is conserved in the sequences of all of the cytosolic enzymes and is found, in crystal structures of both isoenzyme 3-3 from the mu-gene class and an isoenzyme from the pi-gene class, to be proximal to the sulfur of glutathione (GSH) or glutathione sulfonate bound at the active site. The 2.2-angstrom structure of the binary complex of isoenzyme 3-3 and GSH indicates that the hydroxyl group of Tyr6 is located 3.2-3.5 angstrom from the sulfur of GSH, well within hydrogen bonding distance. Removal of the hydroxyl group of Tyr6 has essentially no effect on the dissociation constant (22 +/- 3-mu-M) for GSH. Nevertheless the Y6F mutant exhibits a turnover number which is only about 1% that of the native enzyme when assayed at pH 6.5 with either 1-chloro-2,4-dinitrobenzene (CDNB) or 4-phenyl-3-buten-2-one. UV difference spectra of the binary enzyme-GSH complexes suggest that the predominant ionization state of GSH in the active site of the Y6F mutant is the neutral thiol (eg. E(Y6F).GSH) which is in contrast to the native enzyme in which the thiol is substantially deprotonated (e.g. E.GS-). Spectrophotometric titration suggests that the pK(a) of the thiol is 6.9 +/- 0.3 in the E.GSH complex and greater-than-or-equal-to 8 in the E(Y6F).GSH binary complex. In addition, the pH dependence of k(cat)/K(m)CDNB reveals that the reactions catalyzed by the native enzyme and the Y6F mutant are dependent on a single ionization in the E.GSH and E(Y6F).GSH complexes with pK(a) = 6.2 +/- 0.1 and 7.8 +/- 0.3, respectively. The results suggest that the hydrogen bond between Tyr6 and the enzyme-bound nucleophile helps to lower the pK(a) of GSH in the binary enzyme-substrate complex. C1 UNIV MARYLAND,DEPT CHEM & BIOCHEM,COLLEGE PK,MD 20742. UNIV MARYLAND,MARYLAND BIOTECHNOL INST,CTR ADV RES BIOTECHNOL,SHADY GROVE,MD. NATL INST STAND & TECHNOL,ROCKVILLE,MD 20852. RI Ji, Xinhua/C-9664-2012 OI Ji, Xinhua/0000-0001-6942-1514 FU NIGMS NIH HHS [GM 30910] NR 28 TC 185 Z9 186 U1 0 U2 4 PU AMER SOC BIOCHEMISTRY MOLECULAR BIOLOGY INC PI BETHESDA PA 9650 ROCKVILLE PIKE, BETHESDA, MD 20814 SN 0021-9258 J9 J BIOL CHEM JI J. Biol. Chem. PD MAR 5 PY 1992 VL 267 IS 7 BP 4296 EP 4299 PG 4 WC Biochemistry & Molecular Biology SC Biochemistry & Molecular Biology GA HF642 UT WOS:A1992HF64200006 PM 1537822 ER PT J AU ELSHALL, MS MARKS, C SIECK, LW MEOTNER, M AF ELSHALL, MS MARKS, C SIECK, LW MEOTNER, M TI REACTIONS AND THERMOCHEMISTRY OF PROTONATED METHANOL CLUSTERS PRODUCED BY ELECTRON-IMPACT IONIZATION SO JOURNAL OF PHYSICAL CHEMISTRY LA English DT Article ID CYCLOTRON RESONANCE SPECTROSCOPY; AMMONIA BINARY CLUSTERS; ION-MOLECULE REACTIONS; GAS-PHASE BASICITIES; MULTIPHOTON IONIZATION; MIXED CLUSTERS; HYDROGEN-IONS; WATER; SOLVATION; ALCOHOLS AB Protonated methanol clusters H+(CH3OH)n for n in the range 1-17 have been formed by electron impact ionization of neutral methanol clusters. The formation of H+(H2O)(CH3OH)n clusters is observed to occur only for n greater-than-or-equal-to 6. In CD3OH clusters, both H+(CD3OH)n and D+(CD3OH)n were formed. The D+/H+ ratio showed a strong dependence on cluster size, which is apparently related to neutral boiloff sequences. Reduced data for production of H+(H2O)(CH3OH)n reveals two distinct size-specific manifolds. The results also suggest that the ion H+(CH3OH)3 is particularly stable and corresponds to the filling of the first solvent shell around a protonated methanol molecule. New thermochemical data are presented for the H+(CH3OH)n series. These data show that the limiting attachment energy of CH3OH molecules to the large clusters (9 kcal/mol) is similar to the condensation energy of liquid methanol, and therefore the complex intermolecular forces in the liquid are also present in the clusters. C1 NATL INST STAND & TECHNOL,DIV CHEM KINET & THERMODYNAM,GAITHERSBURG,MD 20899. RP ELSHALL, MS (reprint author), VIRGINIA COMMONWEALTH UNIV,DEPT CHEM,RICHMOND,VA 23284, USA. RI El-Shall, M. Samy/K-8954-2012 OI El-Shall, M. Samy/0000-0002-1013-4948 NR 39 TC 63 Z9 63 U1 2 U2 7 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 SN 0022-3654 J9 J PHYS CHEM-US JI J. Phys. Chem. PD MAR 5 PY 1992 VL 96 IS 5 BP 2045 EP 2051 DI 10.1021/j100184a007 PG 7 WC Chemistry, Physical SC Chemistry GA HG753 UT WOS:A1992HG75300007 ER PT J AU DOMINE, F RAVISHANKARA, AR HOWARD, CJ AF DOMINE, F RAVISHANKARA, AR HOWARD, CJ TI KINETICS AND MECHANISMS OF THE REACTIONS OF CH3S, CH3SO, AND CH3SS WITH O3 AT 300-K AND LOW-PRESSURES SO JOURNAL OF PHYSICAL CHEMISTRY LA English DT Article ID NO2; RADICALS; O-2; THERMOCHEMISTRY; METHANETHIOL; SULFIDE; 298-K; OZONE; HSO; S-2 AB The reactions of CH3S + O3 --> products (1), CH3SO + O3 --> products (2), and CH3SS + O3 --> products (3) were investigated at 300 K in a discharge flow tube reactor coupled to a photoionization mass spectrometer. The measured value of k1 is (5.7 +/- 1.4) x 10(-12) cm3 molecule-1 s-1 in 1 Torr He. We observed that OH was produced in this reaction or in subsequent steps and that complex branched chain reactions, which generate CH3S from its precursor molecule, took place in our flow tube reactor. We found that CH3SO was a product of reaction 1 and the branching ratio for this channel was 15 +/- 4%, between 0.7 and 2.2 Torr He, independent of pressure. A preliminary value of k2 = (6 +/- 3) x 10(-13) cm3 molecule-1 s-1 was measured. CH3S was not a major product of reaction 2. These results suggest that the reaction with O3 is a major CH3S removal process in the atmosphere. The rate coefficient for the reaction of CH3SS with O3 (3) was measured to be k3 = (4.6 +/- 1.1) x 10(-13) cm3 molecule-1 s-1. C1 NOAA,ERL,R E AL2,325 BROADWAY,BOULDER,CO 80303. UNIV COLORADO,NOAA,COOPERAT INST RES ENVIRONM SCI,BOULDER,CO 80309. RI Domine, Florent/E-8699-2011; Ravishankara, Akkihebbal/A-2914-2011 NR 26 TC 42 Z9 44 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 MAR 5 PY 1992 VL 96 IS 5 BP 2171 EP 2178 DI 10.1021/j100184a027 PG 8 WC Chemistry, Physical SC Chemistry GA HG753 UT WOS:A1992HG75300027 ER PT J AU GAIGALAS, AK HUBBARD, JB MCCURLEY, M WOO, S AF GAIGALAS, AK HUBBARD, JB MCCURLEY, M WOO, S TI DIFFUSION OF BOVINE SERUM-ALBUMIN IN AQUEOUS-SOLUTIONS SO JOURNAL OF PHYSICAL CHEMISTRY LA English DT Article ID ELASTIC LIGHT-SCATTERING; PANCREATIC TRYPSIN-INHIBITOR; CONCENTRATION-DEPENDENCE; PROTEIN SOLUTIONS; CORRELATION SPECTROSCOPY; COEFFICIENTS; MACROMOLECULES; CHARGE AB The diffusion coefficient of bovine serum albumin (BSA) was measured in aqueous solutions of varying temperature, pH, BSA concentration, and ionic strength. The measurements were carried out using dynamic light scattering with the photon detector set at a 90-degrees angle. The measured diffusion coefficients were compared to calculated values using phenomenological models which account for the screened Coulomb interaction between the charged proteins, as well as hydrodynamic corrections to the friction factor. The dimensions of BSA were obtained from structural data, and the charge on the protein was estimated using titration data. Although the measured and calculated values of the diffusion coefficient are in general agreement, significant discrepancies are observed. No single theoretical model seems capable of accurate predictions for all ranges of ionic strength and protein concentration. C1 NATL INST STAND & TECHNOL,CTR CHEM TECHNOL,GAITHERSBURG,MD 20899. NR 33 TC 71 Z9 71 U1 1 U2 15 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 SN 0022-3654 J9 J PHYS CHEM-US JI J. Phys. Chem. PD MAR 5 PY 1992 VL 96 IS 5 BP 2355 EP 2359 DI 10.1021/j100184a063 PG 5 WC Chemistry, Physical SC Chemistry GA HG753 UT WOS:A1992HG75300063 ER PT J AU DOUGLAS, JF AF DOUGLAS, JF TI SHIFT IN POLYMER BLEND PHASE-SEPARATION TEMPERATURE IN SHEAR-FLOW SO MACROMOLECULES LA English DT Article ID ANGLE NEUTRON-SCATTERING; LIGHT-SCATTERING; CRITICAL FLUIDS; POLYVINYL METHYL-ETHER); INDUCED HOMOGENIZATION; CRITICAL FLUCTUATIONS; SEMIDILUTE SOLUTION; BINARY-MIXTURES; SCALING LAWS; POLYSTYRENE AB Recent experimental studies of polymer blends in simple shear flow have indicated large "shifts" of the apparent phase-separation temperature. These shifts are examined within the context of a nonequilibrium hydrodynamic theory of phase separation developed by Onuki and Kawasaki. A mean-field version of the hydrodynamic theory indicates that no true shift of the critical temperature T(c) should be observed in high molecular weight polymer blend melts. However, the hydrodynamic theory indicates a large "apparent shift" DELTA parallel-to T(c)(gamma) parallel to the flow direction, DELTA parallel-to T(c)(gamma) approximately gamma(8/15), if the scattering data naively fit to the Ornstein-Zernike function. This spurious "shift" should not be observed in scattering data along the normal to flow direction. These predictions accord qualitatively with experiments on sheared melt blends by Nakatani et al. The apparent shift of T(c) in high molecular weight polymer melt blends is coincidentally similar to the true shift of T(c) observed in small-molecule binary mixtures where DELTA-T(c)(gamma) approximately (gamma)1/3-nu, nu(Ising) = 0.63, is obtained from mode-coupling renormalization group theory. It is argued that a true shift of T(c) should be observed in sufficiently diluted polymer blends in low molecular weight solvents because of a crossover from mean-field to Ising critical behavior upon dilution. RP DOUGLAS, JF (reprint author), NATL INST STAND & TECHNOL,DIV POLYMERS,GAITHERSBURG,MD 20899, USA. NR 67 TC 40 Z9 40 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 MAR 2 PY 1992 VL 25 IS 5 BP 1468 EP 1474 DI 10.1021/ma00031a017 PG 7 WC Polymer Science SC Polymer Science GA HG439 UT WOS:A1992HG43900017 ER PT J AU NEMIROVSKY, AM FREED, KF ISHINABE, T DOUGLAS, JF AF NEMIROVSKY, AM FREED, KF ISHINABE, T DOUGLAS, JF TI END-TO-END DISTANCE OF A SINGLE SELF-INTERACTING SELF-AVOIDING POLYMER-CHAIN - D-1 EXPANSION SO PHYSICS LETTERS A LA English DT Article ID HYPERCUBIC LATTICES; EXACT ENUMERATION; THETA-POINT; WALKS; MODEL AB Exact enumeration data in dimensions d = 2-6 is used to evaluate the exact d-dimensional mean-square end-to-end distance R(n)2 of a short (n less-than-or-equal-to 11) n-bond self-interacting self-avoiding random walk on hypercubic lattices as function of the neighbor contact energy. This exact form is transformed into a large n expansion of R(n)2 through fifth order in d-1 but to all orders in the contact energy. C1 YAMAGATA UNIV,FAC ENGN,YONEZAWA,YAMAGATA 992,JAPAN. NATL INST STAND & TECHNOL,DIV POLYMERS,GAITHERSBURG,MD 20899. RP NEMIROVSKY, AM (reprint author), UNIV CHICAGO,JAMES FRANCK INST,CHICAGO,IL 60637, USA. NR 31 TC 22 Z9 22 U1 0 U2 1 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0375-9601 J9 PHYS LETT A JI Phys. Lett. A PD MAR 2 PY 1992 VL 162 IS 6 BP 469 EP 474 DI 10.1016/0375-9601(92)90008-A PG 6 WC Physics, Multidisciplinary SC Physics GA HJ106 UT WOS:A1992HJ10600008 ER PT J AU CARINO, NJ TANK, RC AF CARINO, NJ TANK, RC TI MATURITY FUNCTIONS FOR CONCRETES MADE WITH VARIOUS CEMENTS AND ADMIXTURES SO ACI MATERIALS JOURNAL LA English DT Article DE ADMIXTURES; CEMENTS; CONCRETES; MATHEMATICAL MODELS; MATURITY; MODELS; MORTARS (MATERIAL); STRENGTH; TEMPERATURE AB The "rate constant model" is proposed for estimating relative strength gain of concrete under different isothermal curing conditions. The key feature of the model is the relationship between curing temperature and the rate constant for relative strength development. The strength-versus-age relationships of seven concrete and mortar mixtures under three curing temperatures were studied. The rate constants were determined by using a hyperbolic strength-age function. A simple exponential function was found to describe the observed variations of the rate constant with curing temperature. It is shown that the relative strength development of concrete can be estimated from its temperature history using parameters determined experimentally from tests of isothermally cured mortar specimens. C1 NARMADA HYDRO POWER PROJECT,GUJARAT,INDIA. RP CARINO, NJ (reprint author), NATL INST STAND & TECHNOL,WASHINGTON,DC 20234, USA. NR 12 TC 49 Z9 51 U1 0 U2 5 PU AMER CONCRETE INST PI FARMINGTON HILLS PA 38800 INTERNATIONAL WAY, COUNTRY CLUB DRIVE, PO BOX 9094, FARMINGTON HILLS, MI 48333-9094 SN 0889-325X J9 ACI MATER J JI ACI Mater. J. PD MAR-APR PY 1992 VL 89 IS 2 BP 188 EP 196 PG 9 WC Construction & Building Technology; Materials Science, Multidisciplinary SC Construction & Building Technology; Materials Science GA HM990 UT WOS:A1992HM99000009 ER PT J AU DEB, KK HILL, MD ROTH, RS KELLY, JF AF DEB, KK HILL, MD ROTH, RS KELLY, JF TI DIELECTRIC AND PYROELECTRIC PROPERTIES OF DOPED LEAD ZINC NIOBATE (PZN) CERAMIC MATERIALS SO AMERICAN CERAMIC SOCIETY BULLETIN LA English DT Article ID SYSTEM; PHASE AB Relaxor ferroelectric materials based on lead zinc niobate (PZN) are candidate materials for IR sensors in night vision equipment. Pyroelectric measurements, as well as measurements of the dielectric constant versus temperature and frequency, were performed. Crystallographic and grain size data are also presented. The peak temperature for the dielectric constant differs from that of the pyroelectric coefficient contributing to a high figure of merit for a pyroelectric IR detector material. C1 NATL INST STAND & TECHNOL,DIV CERAM,ELECTR MAT GRP,GAITHERSBURG,MD 20899. USA,ELECTROOPT DIRECTORATE,FT BELVOIR,VA 22060. RP DEB, KK (reprint author), USA,CECOM,CTR NIGHT VIS,FT BELVOIR,VA 22060, USA. NR 14 TC 4 Z9 4 U1 0 U2 1 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 MAR PY 1992 VL 71 IS 3 BP 349 EP 354 PG 6 WC Materials Science, Ceramics SC Materials Science GA HH557 UT WOS:A1992HH55700014 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 MAR PY 1992 VL 24 IS 5 BP 74 EP 75 PG 2 WC Chemistry, Analytical; Instruments & Instrumentation SC Chemistry; Instruments & Instrumentation GA HH835 UT WOS:A1992HH83500014 ER PT J AU PESKIN, AP RUDGE, SR AF PESKIN, AP RUDGE, SR TI OPTIMIZATION OF LARGE-SCALE CHROMATOGRAPHY FOR BIOTECHNOLOGICAL APPLICATIONS SO APPLIED BIOCHEMISTRY AND BIOTECHNOLOGY LA English DT Article; Proceedings Paper CT 13TH SYMP ON BIOTECHNOLOGY FOR FUELS AND CHEMICALS CY MAY 06-10, 1991 CL COLORADO SPRINGS, CO SP US DOE, NATL RENEWABLE ENERGY LAB, OAK RIDGE NATL LAB, GAS RES INST, BADGER ENGINEERS, COLORADO INST RES BIOTECHNOL, AMER CHEM SOC DE CHROMATOGRAPHY; PARTICLE SIZE; OPTIMIZATION ID PROTEINS; MODEL AB An economic evaluation of a chromatographic separation is discussed. The effects of particle size, cycle time, solvent, and column costs are analyzed. With small particles (< 20-mu-m), the cost of the packing can be as much as 99% of the total cost of the process, whereas with large particles (> 60-mu-m), resin costs are less than half of the total. A strong optimum is found between 20-40-mu-m for maximum productivity, using both Gaussian models and the mass transfer model of Lapidus and Amundson to generate peaks. A new compilation of resin costs, column costs, and pump costs is given. RP PESKIN, AP (reprint author), NATL INST STAND & TECHNOL,DIV CHEM ENGN SCI,83201,325 BROADWAY,BOULDER,CO 80303, USA. NR 14 TC 4 Z9 4 U1 0 U2 0 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 SPR PY 1992 VL 34-5 BP 49 EP 59 DI 10.1007/BF02920533 PG 11 WC Biochemistry & Molecular Biology; Biotechnology & Applied Microbiology SC Biochemistry & Molecular Biology; Biotechnology & Applied Microbiology GA HU375 UT WOS:A1992HU37500006 ER PT J AU MOUNT, GH SANDERS, RW BRAULT, JW AF MOUNT, GH SANDERS, RW BRAULT, JW TI INTERFERENCE EFFECTS IN RETICON PHOTODIODE ARRAY DETECTORS SO APPLIED OPTICS LA English DT Article DE PHOTODIODE ARRAY DETECTORS; INTERFERENCE; ETALONING CHANNELING AB A detector system incorporating the Reticon RL1024S photodiode array has been constructed at the National Oceanic and Atmospheric Administration Aeronomy Laboratory as part of a double spectrograph to be used to study the Earth's atmosphere from ground-based and aircraft-based platforms. To determine accurately the abundances of atmospheric trace gases, this new system must be able to measure spectral absorptions as small as 0.02%. The detector, manufactured by EG&G Reticon, exhibits superior signal-to-noise characteristics at the light levels characteristic of scattered skylights, but interference in the passivating layer (a thin layer of SiO2 that is deposited during the manufacture to protect the silicon active area from water vapor) causes major problems in achieving the required precision. The mechanism of the problems and the solution we have implemented are described in detail. RP MOUNT, GH (reprint author), NOAA,ENVIRONM RES LABS,AERON LAB,325 BROADWAY,BOULDER,CO 80303, USA. NR 3 TC 18 Z9 18 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 MAR 1 PY 1992 VL 31 IS 7 BP 851 EP 858 PG 8 WC Optics SC Optics GA HE657 UT WOS:A1992HE65700001 PM 20720692 ER PT J AU WATANABE, WO SMITH, SJ WICKLUND, RI OLLA, BL AF WATANABE, WO SMITH, SJ WICKLUND, RI OLLA, BL TI HATCHERY PRODUCTION OF FLORIDA RED TILAPIA SEED IN BRACKISHWATER TANKS UNDER NATURAL-MOUTHBROODING AND CLUTCH-REMOVAL METHODS SO AQUACULTURE LA English DT Article ID OREOCHROMIS-NILOTICUS; FRY AB Hatchery production of Florida red tilapia seed (eggs, sacfry and fry) in brackishwater (12 ppt) tanks was studied on Lee Stocking Island (Exuma Cays, Bahamas) under two methods of broodstock management. Six above-ground tanks (34.2 m2) were each stocked with 240 year-class 1 breeders (avg. wt. = 143 g) at a ratio of 3 females to 1 male. Seed production was monitored either under the natural-mouthbrooding method by collecting free-swimming (i.e., post-yolksac stage) fry from tanks every 8-16 days, or under the clutch-removal method by removing free-swimming fry from tanks, and eggs and sacfry from the mouths of brooding females every 15-16 days, and assessing the numbers of each. Seed production over a 3-month period under the natural-mouthbrooding method (3.3 seed m-2 day-1) was significantly lower (P < 0.001) than that obtained under the clutch-removal method (91.7 seed m-2 day-1) which is among the highest reported for tilapia hatcheries. Poor seed production under the natural-mouthbrooding method was attributable to cannibalism of eggs and fry by adults. Hatching success of eggs in upwelling incubators averaged 64.8% with effects of densities of 462, 923, 1385 and 1846/l not differing significantly (P > 0.05). Fry obtained from artificial incubation were significantly (P < 0.05) larger (9.9 mg vs. 7.5 mg) and more viable than those obtained through natural mouthbrooding as evidenced by higher survival (73.9% vs. 49.7%) during a 29-day sex-reversal period. The results suggest that the clutch-removal method, while more labor intensive, yields markedly higher numbers of viable fry for growout. C1 HATFIELD MARINE SCI CTR,NATL MARINE FISHERIES SERV,NW & ALASKA FISHERIES CTR,NEWPORT,OR 97365. RP WATANABE, WO (reprint author), CARIBBEAN MARINE RES CTR,805 E 46TH PL,VERO BEACH,FL 32963, USA. NR 34 TC 9 Z9 10 U1 0 U2 1 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0044-8486 J9 AQUACULTURE JI Aquaculture PD MAR 1 PY 1992 VL 102 IS 1-2 BP 77 EP 88 DI 10.1016/0044-8486(92)90290-2 PG 12 WC Fisheries; Marine & Freshwater Biology SC Fisheries; Marine & Freshwater Biology GA HH272 UT WOS:A1992HH27200008 ER PT J AU VREUX, JM GOSSET, E BOHANNAN, B CONTI, P AF VREUX, JM GOSSET, E BOHANNAN, B CONTI, P TI WR-134 LINE-PROFILE VARIABILITY REVISITED SO ASTRONOMY & ASTROPHYSICS LA English DT Article DE WOLF-RAYET; SPECTROSCOPY; VARIABLE ID WOLF-RAYET STARS; MODEL; HD-191765; HYDROGEN; SPECTRA; BINARY; HELIUM AB Line profile variations of WR 134 are analyzed on more than two hundred spectra collected at Haute Provence Observatory and at Kitt Peak National Observatory. No conclusive evidence is found for a periodic behaviour. However for some frequencies [for example the ones close to v = (n x 0.5) day-1] the data are ill-distributed, and the existence of a related periodic phenomenon cannot be completely ruled out. This does not mean that the variability presents a purely random behaviour. Several new characteristics of the observed deformations are extracted from the analysis of the spectra and it is tentatively suggested that these could be the signature of a bipolar flow. C1 KITT PEAK NATL OBSERV, NOAO, TUCSON, AZ 85726 USA. UNIV COLORADO, NATL INST STAND & TECHNOL, JOINT INST LAB ASTROPHYS, BOULDER, CO 80302 USA. RP VREUX, JM (reprint author), INST ASTROPHYS, 5 AVE COINTE, B-4000 LIEGE, BELGIUM. NR 30 TC 23 Z9 23 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 MAR PY 1992 VL 256 IS 1 BP 148 EP 158 PG 11 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA HH020 UT WOS:A1992HH02000022 ER PT J AU LI, HW MCCRAY, R AF LI, HW MCCRAY, R TI THE (O-I) LAMBDA-LAMBDA-6300, 6364 DOUBLET OF SN-1987A SO ASTROPHYSICAL JOURNAL LA English DT Article DE LINE FORMATION; STARS INDIVIDUAL (SN-1987A); SUPERNOVA REMNANTS; SUPERNOVAE INDIVIDUAL (SN-1987A) ID PHOTOMETRIC-OBSERVATIONS; SUPERNOVA 1987A AB We present model calculations to fit the evolution of the intensity and profile of the [O I] lambda-lambda-6300, 6364 emission doublet observed in the spectrum of SN 1987A. The fact that the doublet ratio R = F(6300)/F(6364) < 3 is evidence that these lines are optically thick for t less-than-or-similar-to 1 yr after outburst. From this, we infer that the oxygen is distributed in a clumpy fashion throughout the supernova envelope. We can fit the data with a three-zone model having 1.3 M. of oxygen distributed within a freely expanding sphere with a volume filling factor f approximately 0.1. The temperature of the oxygen changed from T almost-equal-to 4100 K at day 200 to T almost-equal-to 2900 K at day 500. C1 NBS,BOULDER,CO 80309. RP LI, HW (reprint author), UNIV COLORADO,JOINT INST LAB ASTROPHYS,BOULDER,CO 80309, USA. NR 21 TC 50 Z9 50 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 MAR 1 PY 1992 VL 387 IS 1 BP 309 EP 313 DI 10.1086/171082 PN 1 PG 5 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA HF369 UT WOS:A1992HF36900028 ER PT J AU HILL, RJ OCHS, GR WILSON, JJ AF HILL, RJ OCHS, GR WILSON, JJ TI MEASURING SURFACE-LAYER FLUXES OF HEAT AND MOMENTUM USING OPTICAL SCINTILLATION SO BOUNDARY-LAYER METEOROLOGY LA English DT Article ID INNER SCALE; REFRACTIVE-INDEX; TURBULENCE; TEMPERATURE; FLUCTUATIONS; SPECTRUM; PARAMETERS; HUMIDITY; MOISTURE AB An experiment is described showing that an optical scintillation instrument gives reliable values of heat and momentum fluxes in the surface layer, subject to the usual restrictions of homogeneity and steady state. This instrument measures the turbulence inner scale and refractive-index structure parameter, which are used to obtain the fluxes from Monin-Obukhov similarity relationships. The instrument gives space-averaged values over a propagation path that can range in length from tens to hundreds of meters. The history of the use of optical propagation to estimate fluxes is reviewed. RP HILL, RJ (reprint author), NOAA,ENVIRONM RES LABS,WAVE PROPAGAT LAB,325 BROADWAY,BOULDER,CO 80303, USA. NR 42 TC 63 Z9 66 U1 0 U2 4 PU KLUWER ACADEMIC PUBL PI DORDRECHT PA SPUIBOULEVARD 50, PO BOX 17, 3300 AA DORDRECHT, NETHERLANDS SN 0006-8314 J9 BOUND-LAY METEOROL JI Bound.-Layer Meteor. PD MAR PY 1992 VL 58 IS 4 BP 391 EP 408 DI 10.1007/BF00120239 PG 18 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA HF113 UT WOS:A1992HF11300005 ER PT J AU ELSBERRY, RL HOLLAND, GJ GERRISH, H DEMARIA, M GUARD, CP EMANUEL, K AF ELSBERRY, RL HOLLAND, GJ GERRISH, H DEMARIA, M GUARD, CP EMANUEL, K TI IS THERE ANY HOPE FOR TROPICAL CYCLONE INTENSITY PREDICTION - A PANEL DISCUSSION SO BULLETIN OF THE AMERICAN METEOROLOGICAL SOCIETY LA English DT Discussion AB The outlook tor tropical cyclone intensity forecasts from operational and from research perspectives was discussed during a panel discussion at the 19th Conference on Hurricanes and Tropical Meteorology. Whereas the operational requirement at the National Hurricane Center is to predict maximum 1-min sustained wind speeds at specific locations, the research community is addressing the prediction of the maximum wind or minimum sea level pressure in the storm. Commonality was found in the forecast strategies for subjectively predicting storm intensity. The panelists suggested improvements may be gained from additional observations, better conceptual and theoretical models of storm structure and behavior, and enhancements in statistical and numerical models. The discussion period brought out opposing viewpoints on a number of topics. Both new observations and better use of the existing observations were believed to be necessary. The limitations and advantages of remotely sensed data for this problem were raised. The most vigorous debates were on the physical processes, such as existence or nonexistence of coupling between outer and inner core structure, and whether convection is simply a response to forcing or is an essential contributor to uncertainty in intensity forecasting. Several participants suggested that uncertainties related to the sea surface temperature and its evolution also contribute to the intensity forecast problem. Some specific suggestions for improving intensity forecasts are given in terms of new observations, new basic understandings, and new applied developments. C1 BUR METEOROL,RES CTR,MELBOURNE,AUSTRALIA. NATL HURRICANE CTR,CORAL GABLES,FL. HURRICANE RES DIV,MIAMI,FL. MIT,CAMBRIDGE,MA 02139. RP ELSBERRY, RL (reprint author), USN,POSTGRAD SCH,DEPT METEOROL,CODE MR-ES,MONTEREY,CA 93943, USA. RI DeMaria, Mark/F-5583-2010 NR 10 TC 34 Z9 37 U1 0 U2 5 PU AMER METEOROLOGICAL SOC PI BOSTON PA 45 BEACON ST, BOSTON, MA 02108-3693 SN 0003-0007 J9 B AM METEOROL SOC JI Bull. Amer. Meteorol. Soc. PD MAR PY 1992 VL 73 IS 3 BP 264 EP 275 PG 12 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA HK902 UT WOS:A1992HK90200001 ER PT J AU SKRTIC, D EANES, ED AF SKRTIC, D EANES, ED TI EFFECT OF DIFFERENT PHOSPHOLIPID-CHOLESTEROL MEMBRANE COMPOSITIONS ON LIPOSOME-MEDIATED FORMATION OF CALCIUM PHOSPHATES SO CALCIFIED TISSUE INTERNATIONAL LA English DT Article DE CALCIUM PHOSPHATES; LIPOSOMES; ANIONIC, NEUTRAL PHOSPHOLIPDS; CHOLESTEROL; MATRIX VESICLES ID CONTAINING ANIONIC LIPOSOMES; AQUEOUS SUSPENSIONS; PRECIPITATION; TISSUES; LIPIDS; BONE AB The present report compares the effects of different membrane phospholipid (PL)-cholesterol compositions on the kinetics of liposome-mediated formation of calcium phosphates from metastable solutions (2.25 mM CaCl2; 1.5 mM KH2PO4) at 22-degrees-C, pH 7.4 and 240 mOsm. In most experiments, the liposomes were composed of 7:2:X mixtures of phosphatidylcholine (PC), neutral or acidic phospholipids, and cholesterol (Chol, X = 0, 10, 35, or 50 mol%). The neutral phospholipids (NPL) examined, in addition to PC, were phosphatidylethanolamine (PE) and sphingomyelin (Sph), and the acidic phospholipids (APL) examined were dicetylphosphate (DCP), dioleolylphosphatidylglycerol (DOPG), dioleolylphosphatidic acid (DOPA), phosphatidylserine (PS) and phosphatidylinositol (PI). The 7:2:X liposomes did not initiate mineralization in metastable external solutions per se or, with the exception of DOPA, show extensive Ca-PL binding. However, solution Ca2+ losses due to precipitation occurred when the liposomes were encapsulated with 50 mM KH2PO4 and made permeable to external Ca2+ with X-537A. The extent of these Ca2+ losses was sensitive to both the phospholipid and Chol makeup of the membrane. Moderate-to-extensive intraliposomal precipitation occurred in all 7PC:2APL and 7PC:2NPL liposomes containing 0 or 10 mol% Chol. In contrast, at 50 mol% Chol, mineralization inside all liposomes was negligible. The only significant discriminating effect on internal mineralization among the different phospholipids was observed at 35 mol% Chol, where mineral accumulations ranged from negligible to moderate. At 0 or 10 mol% Chol, extraliposomal precipitation was extensive in all but DOPA- and PS-containing liposomes. However, once intraliposomal yields declined at the higher Chol levels, external mineralization was either delayed or totally blocked in all liposome preparations. Other experiments showed that Sph substituted for PC in 7NPL:2DCP:1Chol liposomes totally blocked both intra- and extraliposomal precipitation. PE substituted in this manner, however, blocked only extraliposomal precipitation. The results of this study suggest that interference of the membrane transport processes controlling intraliposomal precipitation [15] by high (50 mol%) Chol levels is not significantly compromised by the specific APL or NPL incorporated in the membrane. Similarly, the data suggest that Chol does not directly affect the specific interactions of the different membrane APLs with the mineral phase. On the other hand, the substitution of other NPLs for PC can affect the role of APLs such as DCP in liposome-mediated mineralization. C1 NATL INST STAND & TECHNOL,NIDR,BONE RES BRANCH,RES ASSOCIATE PROGRAM,BLDG 224,ROOM A143,GAITHERSBURG,MD 20899. NR 24 TC 13 Z9 13 U1 1 U2 11 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 MAR PY 1992 VL 50 IS 3 BP 253 EP 260 DI 10.1007/BF00296290 PG 8 WC Endocrinology & Metabolism SC Endocrinology & Metabolism GA HD540 UT WOS:A1992HD54000009 PM 1617500 ER PT J AU MARSHALL, WH ECHEVERRIA, TW AF MARSHALL, WH ECHEVERRIA, TW TI AGE, LENGTH, WEIGHT, REPRODUCTIVE-CYCLE AND FECUNDITY OF THE MONKEYFACE PRICKLEBACK (CEBIDICHTHYS-VIOLACEUS) SO CALIFORNIA FISH AND GAME LA English DT Article AB Life history characteristics of age, length, weight, reproductive season and fecundity of the monkeyface prickleback (Cebidichthys violaceus) were investigated. Most specimens were obtained from poke pole anglers during low tides at Dillon Beach, California. Males and females were aged to 18 years old, with males attaining a larger size. Sexual dimorphic growth occurred after age eight, coincident with maturity in females. A complete length-weight curve was constructed. The age-weight curves for males and females were similar. Females mature as early as four years of age with 100% mature by age eight. Spawning occurs from February through April. Two adult females had an estimated 17,000 and 40,000 mature eggs each. C1 NATL MARINE FISHERIES SERV,SW FISHERIES CTR,TIBURON LAB,TIBURON,CA 94920. NR 0 TC 6 Z9 7 U1 0 U2 1 PU CALIF FISH AND GAME EDITOR PI SACRAMENTO PA 1416 NINTH ST, SACRAMENTO, CA 95814 SN 0008-1078 J9 CALIF FISH GAME JI Calif. Fish Game PD SPR PY 1992 VL 78 IS 2 BP 57 EP 64 PG 8 WC Fisheries; Zoology SC Fisheries; Zoology GA JX390 UT WOS:A1992JX39000002 ER PT J AU POLACHECK, T MOUNTAIN, D MCMILLAN, D SMITH, W BERRIEN, P AF POLACHECK, T MOUNTAIN, D MCMILLAN, D SMITH, W BERRIEN, P TI RECRUITMENT OF THE 1987 YEAR CLASS OF GEORGES BANK HADDOCK (MELANOGRAMMUS-AEGLEFINUS) - THE INFLUENCE OF UNUSUAL LARVAL TRANSPORT SO CANADIAN JOURNAL OF FISHERIES AND AQUATIC SCIENCES LA English DT Article ID COD AB Unusually strong along-shelf surface flow in the spring of 1987 transported haddock (Melanogrammus aeglefinus) larvae westward from spawning grounds on Georges Bank into the Middle Atlantic Bight, some as far as 400 km beyond the limits of their normal distribution. 0-Group haddock survived in the Bight in record numbers. Their center of abundance occurred along the outer half of the shelf from Delaware Bay to Martha's Vineyard where more than 97% of the 0-group fish resided in the fall of 1987. Juveniles remained more abundant in the Bight than on the bank through the spring of 1988. Collective evidence suggests that survivors returned to Georges Bank during the late spring/early summer of 1988. The estimated number of 0-group fish in the 1987 year class exceeded all previous estimates from a 27-yr time series which included the 1963 year class, the largest recruited to the fishery since record keeping began in 1931. C1 NOAA,NATL MARINE FISHERIES SERV,SANDY HOOK LAB,HIGHLANDS,NJ 07732. RP POLACHECK, T (reprint author), NOAA,NATL MARINE FISHERIES SERV,WOODS HOLE LAB,WOODS HOLE,MA 02543, USA. NR 39 TC 36 Z9 36 U1 0 U2 0 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 MAR PY 1992 VL 49 IS 3 BP 484 EP 496 DI 10.1139/f92-057 PG 13 WC Fisheries; Marine & Freshwater Biology SC Fisheries; Marine & Freshwater Biology GA HJ150 UT WOS:A1992HJ15000008 ER PT J AU RUGH, DJ BRAHAM, HW MILLER, GW AF RUGH, DJ BRAHAM, HW MILLER, GW TI METHODS FOR PHOTOGRAPHIC IDENTIFICATION OF BOWHEAD WHALES, BALAENA-MYSTICETUS SO CANADIAN JOURNAL OF ZOOLOGY-REVUE CANADIENNE DE ZOOLOGIE LA English DT Article ID BEAUFORT SEA; POPULATION; ALASKA AB Bowhead whales, Balaena mysticetus, have black skin except for patterns of white along their ventral surface and visible dorsally on their lower jaws, caudal peduncles, and flukes. White scar marks may also be present. These contrasting black and white dorsal patterns were examined in 4871 aerial photographs of bowheads taken from 1976 to 1987 to determine if individual animals could be reidentified when subsequently photographed. The objective of making such reidentifications was to provide important life-history information, such as calving intervals, length-specific growth rates, survival rates, and population abundance. This paper describes procedures developed to categorize whales into 20 file types based on the relative extent of visible white markings. Preliminary analysis of the photographic identification system suggests that it has a high potential for use in population studies but only if whale images are of sufficient quality and quantity to allow for multiple reidentifications. High-quality images are best obtained from aerial photographs taken directly above whales in clear water during good to excellent sea-state conditions without glare. This ensures that sufficient characteristic features, if present, are photographed to permit recognition in subsequent photographs. C1 LGL LTD ENVIRONM RES ASSOCIATES,KING CITY L0G 1K0,ONTARIO,CANADA. RP RUGH, DJ (reprint author), NOAA,NATL MARINE FISHERIES SERV,ALASKA FISHERIES SCI CTR,NATL MARINE MAMMAL LAB,SEATTLE,WA 98115, USA. NR 36 TC 10 Z9 13 U1 1 U2 4 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 MAR PY 1992 VL 70 IS 3 BP 617 EP 624 DI 10.1139/z92-090 PG 8 WC Zoology SC Zoology GA JA428 UT WOS:A1992JA42800029 ER PT J AU Ferrer, S Miller, BR AF Ferrer, Sebastian Miller, Bruce R. TI COORDINATES FOR PERTURBED KEPLERIAN SYSTEMS WITH AXIAL SYMMETRY SO CELESTIAL MECHANICS & DYNAMICAL ASTRONOMY LA English DT Article DE axial symmetry; coordinates; Keplerian; normalization; reduction AB A coordinate system is defined on the phase space of a perturbed Keplerian system after the mean anomaly has been averaged out, for the purpose of explaining how eliminating the longitude of the ascending node reduces the orbital space to a two-dimensional sphere in case the system admits an axial symmetry. Concomitantly, on the submanifold of direct osculating ellipses, the CDM variables are replaced by functions which form the basis of a Poisson algebra isomorphic to the Lie algebra so(3) of the rotation group SO( 3); furthermore, in these variables, the doubly reduced phase flow appears like a rotation of the reduced phase space. C1 [Ferrer, Sebastian] Univ Zaragoza, Grp Mecan Espacial, E-50009 Zaragoza, Spain. [Miller, Bruce R.] Natl Inst Stand & Technol, Gaithersburg, MD 20899 USA. RP Ferrer, S (reprint author), Univ Zaragoza, Grp Mecan Espacial, E-50009 Zaragoza, Spain. EM ferrer@cc.unizar.es; miller@cam.nist.gov NR 2 TC 0 Z9 0 U1 0 U2 0 PU SPRINGER PI DORDRECHT PA VAN GODEWIJCKSTRAAT 30, 3311 GZ DORDRECHT, NETHERLANDS SN 0923-2958 J9 CELEST MECH DYN ASTR JI Celest. Mech. Dyn. Astron. PD MAR PY 1992 VL 53 IS 1 BP 3 EP 10 PG 8 WC Astronomy & Astrophysics; Mathematics, Interdisciplinary Applications SC Astronomy & Astrophysics; Mathematics GA V05MX UT WOS:000207131200002 ER PT J AU REIS, KP PRINCE, E WHITTINGHAM, MS AF REIS, KP PRINCE, E WHITTINGHAM, MS TI RIETVELD ANALYSIS OF NAXWO3+X/2.YH2O, WHICH HAS THE HEXAGONAL TUNGSTEN BRONZE STRUCTURE SO CHEMISTRY OF MATERIALS LA English DT Article ID NEUTRON-DIFFRACTION; WO3 AB Powder neutron diffraction and Rietveld analysis were used to investigate the crystal structures of hydrated and deuterated samples of NaxWO3+x/2.yH2O (x approximately 0.17, y approximately 0.23). The compound, which crystallizes with the symmetry of space group P6/mmm, is related to the hexagonal tungsten bronze structure but differs from it due to the presence of sodium and oxygen along the hexagonal tunnel. Some of the oxygens appear in the structure as water molecules. The oxygen is disordered along the z axis in the hexagonal cavity with sodium in the hexagonal window. C1 SUNY BINGHAMTON,DEPT CHEM,BINGHAMTON,NY 13902. NATL INST STAND & TECHNOL,MAT SCI & ENGN LAB,GAITHERSBURG,MD 20899. SUNY BINGHAMTON,MAT RES CTR,BINGHAMTON,NY 13902. NR 18 TC 35 Z9 35 U1 0 U2 3 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 SN 0897-4756 J9 CHEM MATER JI Chem. Mat. PD MAR-APR PY 1992 VL 4 IS 2 BP 307 EP 312 DI 10.1021/cm00020a016 PG 6 WC Chemistry, Physical; Materials Science, Multidisciplinary SC Chemistry; Materials Science GA HL702 UT WOS:A1992HL70200016 ER PT J AU NEELIN, JD LATIF, M ALLAART, MAF CANE, MA CUBASCH, U GATES, WL GENT, PR GHIL, M GORDON, C LAU, NC MECHOSO, CR MEEHL, GA OBERHUBER, JM PHILANDER, SGH SCHOPF, PS SPERBER, KR STERL, A TOKIOKA, T TRIBBIA, J ZEBIAK, SE AF NEELIN, JD LATIF, M ALLAART, MAF CANE, MA CUBASCH, U GATES, WL GENT, PR GHIL, M GORDON, C LAU, NC MECHOSO, CR MEEHL, GA OBERHUBER, JM PHILANDER, SGH SCHOPF, PS SPERBER, KR STERL, A TOKIOKA, T TRIBBIA, J ZEBIAK, SE TI TROPICAL AIR-SEA INTERACTION IN GENERAL-CIRCULATION MODELS SO CLIMATE DYNAMICS LA English DT Review ID EASTERN EQUATORIAL PACIFIC; NINO SOUTHERN OSCILLATION; PLANETARY BOUNDARY-LAYER; WIND STRESS PATTERNS; EL-NINO; SURFACE TEMPERATURE; OCEAN MODEL; WORLD OCEAN; SEASONAL CYCLE; ATMOSPHERIC CIRCULATION AB An intercomparison is undertaken of the tropical behavior of 17 coupled ocean-atmosphere models in which at least one component may be termed a general circulation model (GCM). The aim is to provide a taxonomy-a description and rough classification-of behavior across the ensemble of models, focusing on interannual variability. The temporal behavior of the sea surface temperature (SST) field along the equator is presented for each model, SST being chosen as the primary variable for intercomparison due to its crucial role in mediating the coupling and because it is a sensitive indicator of climate drift. A wide variety of possible types of behavior are noted among the models. Models with substantial interannual tropical variability may be roughly classified into cases with propagating SST anomalies and cases in which the SST anomalies develop in place. A number of the models also exhibit significant drift with respect to SST climatology. However, there is not a clear relationship between climate drift and the presence or absence of interannual oscillations. In several cases, the mode of climate drift within the tropical Pacific appears to involve coupled feedback mechanisms similar to those responsible for El Nino variability. Implications for coupled-model development and for climate prediction on seasonal to interannual time scales are discussed. Overall, the results indicate considerable sensitivity of the tropical coupled ocean-atmosphere system and suggest that the simulation of the warm-pool/cold-tongue configuration in the equatorial Pacific represents a challenging test for climate model parameterizations. C1 MAX PLANCK INST METEOROL, W-2000 HAMBURG, GERMANY. KONINKLIJK NEDERLANDS METEOROL INST, DE BILDT, NETHERLANDS. GEOPHYS FLUID DYNAM LAB, PRINCETON, NJ 08542 USA. PRINCETON UNIV, ATMOSPHER & OCEAN SCI PROGRAM, PRINCETON, NJ 08542 USA. METEOROL RES INST, TSUKUBA, IBARAKI 305, JAPAN. COLUMBIA UNIV, LAMONT DOHERTY GEOL OBSERV, PALISADES, NY 10964 USA. UNIV CALIF LAWRENCE LIVERMORE NATL LAB, LIVERMORE, CA 94550 USA. NATL CTR ATMOSPHER RES, BOULDER, CO 80307 USA. UNIV CALIF LOS ANGELES, INST GEOPHYS & PLANETARY PHYS, LOS ANGELES, CA 90024 USA. NASA, GODDARD SPACE FLIGHT CTR, HYDROSPHER PROC LAB, GREENBELT, MD 20771 USA. UNIV OXFORD, CLARENDON LAB, HOOKE INST ATMOSPHERE RES, METEOROL UNIT, OXFORD OX1 3PU, ENGLAND. RP NEELIN, JD (reprint author), UNIV CALIF LOS ANGELES, DEPT ATMOSPHER SCI, LOS ANGELES, CA 90024 USA. RI Neelin, J. David/H-4337-2011; Cane, Mark/I-8086-2012; Sperber, Kenneth/H-2333-2012; Latif, Mojib/C-2428-2016 OI Latif, Mojib/0000-0003-1079-5604 NR 136 TC 157 Z9 165 U1 1 U2 12 PU SPRINGER PI NEW YORK PA 233 SPRING ST, NEW YORK, NY 10013 USA SN 0930-7575 J9 CLIM DYNAM JI Clim. Dyn. PD MAR PY 1992 VL 7 IS 2 BP 73 EP 104 PG 32 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA HL450 UT WOS:A1992HL45000002 ER PT J AU KASHIWAGI, T NAMBU, H AF KASHIWAGI, T NAMBU, H TI GLOBAL KINETIC CONSTANTS FOR THERMAL OXIDATIVE-DEGRADATION OF A CELLULOSIC PAPER SO COMBUSTION AND FLAME LA English DT Article ID PYROLYSIS; NITROGEN; AIR AB Values of global kinetic constants for pyrolysis, thermal oxidative degradation, and char oxidation of a cellulosic paper were determined by a derivative thermal gravimetric study. The study was conducted at heating rates of 0.5, 1, 1.5, 3, and 5-degrees-C/min in ambient atmospheres of nitrogen, 0.28%, 1.08%, 5.2% oxygen concentrations, and air. Sample weight loss rate, concentrations of CO, CO2, and H2O in the degradation products, and oxygen consumption were continuously measured during the experiment. Values of activation energy, pre-exponential factor, orders of reaction, and yields of CO, CO2, H2O, total hydrocarbons, and char for each degradation reaction were derived from the results. Heat of reaction for each reaction was determined by differential scanning calorimetry. A comparison of the calculated CO, CO2, H2O, total hydrocarbons, sample weight loss rate, and oxygen consumption was made with the measured results using the derived kinetic constants and accuracy of the values of kinetic constants was discussed. RP KASHIWAGI, T (reprint author), NATL INST STAND & TECHNOL,BLDG & FIRE RES LAB,GAITHERSBURG,MD 20899, USA. NR 22 TC 111 Z9 117 U1 0 U2 11 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 MAR PY 1992 VL 88 IS 3-4 BP 345 EP 368 DI 10.1016/0010-2180(92)90039-R PG 24 WC Thermodynamics; Energy & Fuels; Engineering, Multidisciplinary; Engineering, Chemical; Engineering, Mechanical SC Thermodynamics; Energy & Fuels; Engineering GA HJ453 UT WOS:A1992HJ45300006 ER PT J AU DIZON, AE LOCKYER, C PERRIN, WF DEMASTER, DP SISSON, J AF DIZON, AE LOCKYER, C PERRIN, WF DEMASTER, DP SISSON, J TI RETHINKING THE STOCK CONCEPT - A PHYLOGEOGRAPHIC APPROACH SO CONSERVATION BIOLOGY LA English DT Article AB The "stock" is the fundamental population unit of legally mandated conservation efforts, yet its formal definition in the scientific literature and in two U.S. conservation acts is varied and so general that attempts to apply it in practice are arbitrary. Because choice of stocks deserving management protection is sometimes politically contentious, improvement of the working definition is important. A key element should be the degree to which a population can be considered an evolutionarily significant unit. We propose that a hierarchial classification scheme be applied to stock designations. Category I populations, having the highest probability of being evolutionarily significant units, are characterized by a discontinuous genetic divergence pattern where locally adapted and closely related genome assemblages are separated from others geographically and by significant genetic distances. Category II populations are similarly characterized by significant genetic diversity, but with weak geographic partitioning. Category III populations are the converse of II, having little genetic differentiation between assemblages that are clearly separate and likely to be reproductively isolated. Category IV assemblages have the lowest probability of being evolutionarily significant units and are characterized by extensive gene flow and no subdivision by extrinsic barriers. In addition to phylogeographic designation, the following information is used in the classification, as indicated by single-letter abbreviations: distribution (a), population response (b), phenotypic (c), and genotypic (d) information. Included are evidence both for and against designating population as a separate stock. In the designation "Type II a/bc," for example, information to the right of the solidus would be evidence for "lumping," to the left would be for "splitting." Missing letter abbreviations would signify lack of reliable data. Note that phylogeographic designation depends on the results of selection operating to produce a locally adapted genome (indicated by differences in demographic, phenotypic, and genotypic measures) and on gene flow (indicated by differences in distribution or by movement data). Hierarchial stock categorization allows resource managers to direct limited resources to the populations most deserving of protection, that is, the populations that are most likely to be evolutionarily significant units. Using this comprehensive classification of stock allows preliminary, conservative splitting of assemblages where data are lacking without the danger that these divisions will become entrenched as biological dogma. RP DIZON, AE (reprint author), NATL MARINE FISHERIES SERV,SW FISHERIES SCI CTR,LA JOLLA,CA 92038, USA. NR 0 TC 157 Z9 164 U1 0 U2 12 PU BLACKWELL SCIENCE INC PI MALDEN PA 350 MAIN ST, MALDEN, MA 02148 SN 0888-8892 J9 CONSERV BIOL JI Conserv. Biol. PD MAR PY 1992 VL 6 IS 1 BP 24 EP 36 DI 10.1046/j.1523-1739.1992.610024.x PG 13 WC Biodiversity Conservation; Ecology; Environmental Sciences SC Biodiversity & Conservation; Environmental Sciences & Ecology GA HM029 UT WOS:A1992HM02900010 ER PT J AU BOEHLERT, GW WATSON, W SUN, LC AF BOEHLERT, GW WATSON, W SUN, LC TI HORIZONTAL AND VERTICAL DISTRIBUTIONS OF LARVAL FISHES AROUND AN ISOLATED OCEANIC ISLAND IN THE TROPICAL PACIFIC SO DEEP-SEA RESEARCH PART A-OCEANOGRAPHIC RESEARCH PAPERS LA English DT Article ID GREAT BARRIER-REEF; CORAL-REEF; SARGASSO SEA; LIZARD ISLAND; RECRUITMENT; PATTERNS; MASS; ICHTHYOPLANKTON; MESOZOOPLANKTON; LEPTOCEPHALI AB Ichthyoplankton and oceanographic sampling was conducted in November 1984 in waters surrounding Johnston Atoll (16-degrees-44'N, 169-degrees-32'W). a small, isolated atoll in the central Pacific Ocean. The typical flow pattern in this region is westward; the nearest island is in the Hawaiian Archipelago, 760 km away. Most collections were dominated by oceanic taxa. In the 0-50 m stratum, larval densities were relatively uniform horizontally. but densities down-current of the island tended to be higher, and fish eggs were concentrated there. In the 50-100 m stratum. larval abundance on the down-current side of the island was markedly higher than either up-current or farther down-current. Oceanic taxa did not display this pattern, while marked areas of very high abundance characterized the island-related taxa, the most abundant including the gobiid Eviota epiphanes and the apogonid Pseudamiops sp. Estimates of geostrophic flow indicate that the region down-current of the atoll was one of return flow associated with apparent mesoscale eddies or meanders north and west of the island. This region may serve as a down-current retention area for the pelagic larvae of island-related taxa and may facilitate recruitment back to the source populations. C1 NOAA, NATL MARINE FISHERIES SERV, SW FISHERIES SCI CTR, LA JOLLA, CA 92038 USA. UNIV HAWAII, JOINT INST MARINE & ATMOSPHER RES, HONOLULU, HI 96822 USA. UNIV HAWAII, HAWAII INST GEOPHYS, HONOLULU, HI 96822 USA. RP NOAA, NATL MARINE FISHERIES SERV, SW FISHERIES SCI CTR, HONOLULU LAB, 2570 DOLE ST, HONOLULU, HI 96822 USA. NR 71 TC 87 Z9 92 U1 0 U2 7 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLAND SN 0198-0149 J9 DEEP-SEA RES PD MAR-APR PY 1992 VL 39 IS 3-4A BP 439 EP 466 DI 10.1016/0198-0149(92)90082-5 PG 28 WC Oceanography SC Oceanography GA HR309 UT WOS:A1992HR30900004 ER PT J AU RONA, PA TRIVETT, DA AF RONA, PA TRIVETT, DA TI DISCRETE AND DIFFUSE HEAT-TRANSFER AT ASHES VENT FIELD, AXIAL VOLCANO, JUAN-DE-FUCA-RIDGE SO EARTH AND PLANETARY SCIENCE LETTERS LA English DT Article ID EAST-PACIFIC-RISE; HYDROTHERMAL FLUIDS; SEAMOUNT; PLUME; FLOW; TEMPERATURE; SUMMIT AB Heat fluxes of discrete and diffuse components of hydrothermal discharge are estimated from submersible measurement in the ASHES vent field located in the caldera of Axial Volcano on the central Juan de Fuca Ridge. The discrete component comprises discharge from individual vents and the diffuse component comprises seepage from large areas of the seafloor. The investigation centered on the high-temperature portion of the field, a 100 x 100 m area of fractured lobate and sheet lava flows encompassing discrete discharge (less-than-or-equal-to 326-degrees-C) from seven individual vents and diffuse flow from intervening areas. A total of 4.4 +/- 2 x 10(6)W was estimated for the discrete heat flux based on measurements of effluent temperature, flow rate and orifice diameter at all the known individual vents by D.S.V. Alvin in September 1987. A total of 15-75 x 10(6)W was calculated with a standard plume model for the diffuse flux based on a grid of temperature measurements at altitudes of 1 m and 20 m above the study area using a 1 m long vertical array of temperature sensors mounted at the front of Alvin's instrument platform. The study indicates that (1) the diffuse component rises separately from the discrete component of hydrothermal discharge and is laterally advected by a prevailing current below the discrete component, and that (2) the diffuse component of convective heat flux is approximately an order of magnitude greater than the discrete component in the high-temperature portion of the ASHES vent field. C1 WOODS HOLE OCEANOG INST,DEPT APPL OCEAN PHYS & ENGN,WOODS HOLE,MA 02543. RP RONA, PA (reprint author), NOAA,ATLANTIC OCEANOG & ATMOSPHER LAB,4301 RICKENBACKER CAUSEWAY,MIAMI,FL 33149, USA. NR 30 TC 74 Z9 77 U1 1 U2 3 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0012-821X J9 EARTH PLANET SC LETT JI Earth Planet. Sci. Lett. PD MAR PY 1992 VL 109 IS 1-2 BP 57 EP 71 DI 10.1016/0012-821X(92)90074-6 PG 15 WC Geochemistry & Geophysics SC Geochemistry & Geophysics GA HN989 UT WOS:A1992HN98900006 ER PT J AU FONTAINE, TD STEWART, DJ AF FONTAINE, TD STEWART, DJ TI EXPLORING THE EFFECTS OF MULTIPLE MANAGEMENT-OBJECTIVES AND EXOTIC SPECIES ON GREAT-LAKES FOOD WEBS AND CONTAMINANT DYNAMICS SO ENVIRONMENTAL MANAGEMENT LA English DT Article DE FISHERIES; PHOSPHORUS; CONTAMINANTS; ECOSYSTEM; MANAGEMENT; SIMULATION MODEL; GREAT LAKES ID WATER-QUALITY TRENDS; SALMONINE PREDATION; MICHIGAN; ALEWIVES; WEATHER; MODEL AB A simulation model was developed to describe linkages among fish food web, nutrient cycling, and contaminant processes in the southern basin of Lake Michigan. The model was used to examine possible effects of management actions and an exotic zooplankter (Bythotrephes) on Lake Michigan food web and contaminant dynamics. The model predicts that contaminant concentrations in salmonines will decrease by nearly 20% if Bythotrephes successfully establishes itself in the lake. The model suggests that this decrease will result from lowered transfer efficiencies within the food web and increased flux of contaminants to the hypolimnion. The model also indicates that phosphorus management will have little effect on contaminant concentrations in salmonines. The modeling exercise helped identify weaknesses in the data base (e.g., incomplete information on contaminant loadings and on the biomass, production, and ecological efficiencies of dominant organisms) that should be corrected in order to make reliable management decisions. C1 NOAA,GREAT LAKES ENVIRONM RES LAB,ANN ARBOR,MI 48105. SUNY COLL OSWEGO,OSWEGO,NY 13126. SUNY COLL ENVIRONM SCI & FORESTRY,SYRACUSE,NY 13210. NR 16 TC 4 Z9 4 U1 2 U2 11 PU SPRINGER VERLAG PI NEW YORK PA 175 FIFTH AVE, NEW YORK, NY 10010 SN 0364-152X J9 ENVIRON MANAGE JI Environ. Manage. PD MAR-APR PY 1992 VL 16 IS 2 BP 225 EP 229 DI 10.1007/BF02393827 PG 5 WC Environmental Sciences SC Environmental Sciences & Ecology GA HF767 UT WOS:A1992HF76700009 ER PT J AU FOGARTY, MJ ROSENBERG, AA SISSENWINE, MP AF FOGARTY, MJ ROSENBERG, AA SISSENWINE, MP TI FISHERIES RISK ASSESSMENT SOURCES OF UNCERTAINTY SO ENVIRONMENTAL SCIENCE & TECHNOLOGY LA English DT Article ID MEASUREMENT ERRORS; RECRUITMENT; STOCK; POPULATIONS; MANAGEMENT C1 UNIV RHODE ISL,OCEANOG,KINGSTON,RI 02881. RP FOGARTY, MJ (reprint author), NOAA,NATL MARINE FISHERIES SERV,NE FISHERIES CTR,WOODS HOLE,MA 02543, USA. NR 27 TC 24 Z9 25 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 MAR PY 1992 VL 26 IS 3 BP 440 EP 447 DI 10.1021/es00027a600 PG 8 WC Engineering, Environmental; Environmental Sciences SC Engineering; Environmental Sciences & Ecology GA HG158 UT WOS:A1992HG15800007 ER PT J AU YANG, J BOND, LJ AF YANG, J BOND, LJ TI ULTRASONIC TECHNIQUE FOR SIZING VOIDS BY USING AREA FUNCTIONS SO IEE PROCEEDINGS-A-SCIENCE MEASUREMENT AND TECHNOLOGY LA English DT Article DE NONDESTRUCTIVE EVALUATION; ULTRASONICS; AREA FUNCTION INVERSION ID NONDESTRUCTIVE EVALUATION; SCATTERING; FLAWS AB A technique is reported for determining the sizes of voids in structural materials by the inversion of backscattered ultrasonic signals using the area function formula. The formulation of this method is based on the Born approximation which is a weak scattering approximation, but it is shown to work well for voids. Results for extracting the radii of spherical voids, or the tangent plane distances of spheroical voids are presented, using theoretical and experimental scattering data. C1 UNIV COLORADO,DEPT MECH ENGN,BOULDER,CO 80309. NATL INST STAND & TECHNOL,BOULDER,CO. RP YANG, J (reprint author), UNIV LONDON UNIV COLL,DEPT MECH ENGN,TORRINGTON PL,LONDON WC1E 7JE,ENGLAND. NR 15 TC 1 Z9 1 U1 0 U2 1 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 MAR PY 1992 VL 139 IS 2 BP 45 EP 50 PG 6 WC Engineering, Electrical & Electronic SC Engineering GA HJ799 UT WOS:A1992HJ79900001 ER PT J AU HERMANNS, A BENKERT, C LININGER, DM ANDERSON, DZ AF HERMANNS, A BENKERT, C LININGER, DM ANDERSON, DZ TI THE TRANSFER-FUNCTION AND IMPULSE-RESPONSE OF PHOTOREFRACTIVE 2-BEAM COUPLING SO IEEE JOURNAL OF QUANTUM ELECTRONICS LA English DT Article ID TRANSIENT ENERGY-TRANSFER; HOLOGRAM FORMATION; PHASE CONJUGATION; GRATING FORMATION; MEDIA; CRYSTALS; BATIO3 AB We derive the transfer function and impulse response of photorefractive two-beam coupling in the undepleted pump approximation. For sufficiently strong coupling GAMMA-L, the impulse response features a broad delayed output pulse. In the two interesting limits of negligible and strong absorption alpha-L, this coupling threshold reads GAMMA-L(thr) = 4 and GAMMA(thr) = 2-alpha, respectively. The time delay and pulse height are functions of the coupling GAMMA-L, the photorefractive time constant tau and the effective absorption alpha-L. Experiments on a BaTiO3 crystal measuring the absolute square of its transfer function and the impulse response are used to determine the coupling and time constant. The experimental impulse response is found to differ from the inverse Laplace transform of the transfer function. We speculate that the discrepancy is due to beam fanning. C1 UNIV COLORADO,NIST,JOINT INST LAB ASTROPHYS,BOULDER,CO 80309. RP HERMANNS, A (reprint author), UNIV COLORADO,DEPT PHYS,BOULDER,CO 80309, USA. NR 21 TC 17 Z9 17 U1 0 U2 1 PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017-2394 SN 0018-9197 J9 IEEE J QUANTUM ELECT JI IEEE J. Quantum Electron. PD MAR PY 1992 VL 28 IS 3 BP 750 EP 756 DI 10.1109/3.125000 PG 7 WC Engineering, Electrical & Electronic; Optics; Physics, Applied SC Engineering; Optics; Physics GA HG906 UT WOS:A1992HG90600023 ER PT J AU FREY, MR AF FREY, MR TI CAPACITY OF THE LP NORM-CONSTRAINED POISSON CHANNEL SO IEEE TRANSACTIONS ON INFORMATION THEORY LA English DT Note DE POISSON CHANNEL; DIRECT-DETECTION PHOTON CHANNEL; CAPACITY; LP NORM; CAUSAL FEEDBACK; ON OFF KEYING AB The capacity of the Poisson channel is derived with a constraint imposed on the L(p) norm parallel-to chi(t)parallel-to (p) of the encoder intensity-chi; that is, 1 less-than-or-equal-to p less-than-or-equal-to infinity is fixed and it is supposed that parallel-to chi(t)parallel-to(p) less-than-or-equal-to Q for all t is-an-element-of [0, T] and some Q greater-than-or-equal-to 0. Formulae are given for the capacity which establish previously known results for p = 1, p = 2, and p = infinity to be part of a system of capacity problems with common form and solution. These formulae apply with or without causal feedback and whether or not the encoder intensity is OOK-constrained. RP FREY, MR (reprint author), NATL INST STAND & TECHNOL, CTR COMP & APPL MATH, DIV STAT ENGN, ADM BLDG A334, GAITHERSBURG, MD 20899 USA. NR 10 TC 6 Z9 6 U1 0 U2 0 PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC PI PISCATAWAY PA 445 HOES LANE, PISCATAWAY, NJ 08855-4141 USA SN 0018-9448 EI 1557-9654 J9 IEEE T INFORM THEORY JI IEEE Trans. Inf. Theory PD MAR PY 1992 VL 38 IS 2 BP 445 EP 450 DI 10.1109/18.119702 PN 1 PG 6 WC Computer Science, Information Systems; Engineering, Electrical & Electronic SC Computer Science; Engineering GA HG006 UT WOS:A1992HG00600020 ER PT J AU RAVIV, D ALBUS, JS AF RAVIV, D ALBUS, JS TI A CLOSED-FORM MASSIVELY-PARALLEL RANGE-FROM-IMAGE-FLOW ALGORITHM SO IEEE TRANSACTIONS ON SYSTEMS MAN AND CYBERNETICS LA English DT Note ID MOTION PARAMETERS; 3-DIMENSIONAL MOTION; OPTICAL-FLOW; OBJECTS AB A closed-form solution for obtaining three-dimensional (3-D) structure of a scene for a given six degree of freedom motion of camera is provided. The solution is massively parallel, i.e., the range that corresponds to each pixel is dependent on the spatial and temporal changes in intensities of that pixel, and on the motion parameters of the camera. The measurements of the intensities are done in a priori known directions. The solution is for the general case of camera motion. The derivation is based upon representing the image in the spherical coordinate system, although a similar approach could be taken for other image domains, e.g., the planar coordinate system. Comments are made on the amount of computations, error and singular points of the solutions. A practical way to significantly reduce and implement them is suggested. C1 NATL INST STAND & TECHNOL,DIV ROBOT SYST,GAITHERSBURG,MD 20899. FLORIDA ATLANTIC UNIV,DEPT ELECT ENGN,BOCA RATON,FL 33431. RP RAVIV, D (reprint author), FLORIDA ATLANTIC UNIV,CTR ROBOT,BOCA RATON,FL 33431, USA. NR 24 TC 1 Z9 1 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 0018-9472 J9 IEEE T SYST MAN CYB JI IEEE Trans. Syst. Man Cybern. PD MAR-APR PY 1992 VL 22 IS 2 BP 322 EP 327 DI 10.1109/21.148405 PG 6 WC Computer Science, Cybernetics; Engineering, Electrical & Electronic SC Computer Science; Engineering GA JF034 UT WOS:A1992JF03400011 ER PT J AU GIESEY, JJ CARSON, PL FITTING, DW MEYER, CR AF GIESEY, JJ CARSON, PL FITTING, DW MEYER, CR TI SPECKLE REDUCTION IN PULSE ECHO ULTRASONIC-IMAGING USING A 2-DIMENSIONAL RECEIVING ARRAY SO IEEE TRANSACTIONS ON ULTRASONICS FERROELECTRICS AND FREQUENCY CONTROL LA English DT Article ID IMAGES; IMPROVEMENT; TOMOGRAPHY; ERROR AB An experimental pulse-echo imager was developed for the purpose of reducing speckle in ultrasonic images. The system utilized a 64 element spherically focused segmented annuli array receiver with a common transmitter. Compounded images were formed using subapertures of varying size, shape and overlap, and the speckle and resolution characteristics of the final images observed. A point-like scatterer was imaged to determine the resolution, point spread function and sensitivity of the system along with a new measure called the resolution cell size. The response of the system was also simulated for comparisons. Images were made of a uniformly scattering material to determine the speckle signal-to-noise ratio, the speckle spot size and a measure of image quality, the normalized contrast-to-speckle ratio. Lateral resolution and resolution cell sizes only gradually increased with a decrease in subaperture size and system sensitivity was not greatly diminished. Incoherent summation of signals from small groups of elements, as compared to coherent summation, decreased the speckle noise by a factor of four while maintaining enough resolution to improve the image quality as measured by the CSR/d by a factor of almost two. The subaperture shape and orientation of overlap were also found to be significant. C1 UNIV MICHIGAN HOSP,DEPT RADIOL,ANN ARBOR,MI 48109. NATL INST STAND & TECHNOL,DIV MAT RELIABIL,BOULDER,CO 80303. RP GIESEY, JJ (reprint author), OHIO UNIV,DEPT ELECT & COMP ENGN,ATHENS,OH 45701, USA. NR 19 TC 6 Z9 6 U1 0 U2 2 PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017-2394 SN 0885-3010 J9 IEEE T ULTRASON FERR JI IEEE Trans. Ultrason. Ferroelectr. Freq. Control PD MAR PY 1992 VL 39 IS 2 BP 167 EP 173 DI 10.1109/58.139111 PG 7 WC Acoustics; Engineering, Electrical & Electronic SC Acoustics; Engineering GA HV423 UT WOS:A1992HV42300002 PM 18263133 ER PT J AU WALLS, FL GAGNEPAIN, JJ AF WALLS, FL GAGNEPAIN, JJ TI ENVIRONMENTAL SENSITIVITIES OF QUARTZ OSCILLATORS SO IEEE TRANSACTIONS ON ULTRASONICS FERROELECTRICS AND FREQUENCY CONTROL LA English DT Article AB The frequency, amplitude, and noise of the output signal of a quartz oscillator are affected by a large number of environmental effects. The paper examines the physical basis for the sensitivity of precision oscillators to temperature, humidity, pressure, acceleration and vibration, magnetic field, electric field, load, and radiation. The sensitivity of quartz oscillators to radiation is a very complex topic and poorly understood. Therefore only a few general results are mentioned. The sensitivity to most external influences often varies significantly both from one oscillator type to another and from one unit of a given type to another. For a given unit, the sensitivity to one parameter often depends on the value of other parameters and on history. Representative sensitivity to the above parameters will be given. C1 UNIV FRANCHE COMTE BESANCON,CNRS,PHYS & METROL OSCILLATEURS LAB,F-25000 BESANCON,FRANCE. RP WALLS, FL (reprint author), NATL INST STAND & TECHNOL,DIV TIME & FREQUENCY,325 BROADWAY,BOULDER,CO 80303, USA. NR 67 TC 32 Z9 33 U1 1 U2 2 PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017-2394 SN 0885-3010 J9 IEEE T ULTRASON FERR JI IEEE Trans. Ultrason. Ferroelectr. Freq. Control PD MAR PY 1992 VL 39 IS 2 BP 241 EP 249 DI 10.1109/58.139120 PG 9 WC Acoustics; Engineering, Electrical & Electronic SC Acoustics; Engineering GA HV423 UT WOS:A1992HV42300011 PM 18263142 ER PT J AU CRAFT, NE SOARES, JH AF CRAFT, NE SOARES, JH TI RELATIVE SOLUBILITY, STABILITY, AND ABSORPTIVITY OF LUTEIN AND BETA-CAROTENE IN ORGANIC-SOLVENTS SO JOURNAL OF AGRICULTURAL AND FOOD CHEMISTRY LA English DT Article ID LIQUID-CHROMATOGRAPHY; PLASMA; GREEN AB The relative solubility, stability, and absorptivity of lutein and beta-carotene were determined in 18 organic solvents. The solubility of both carotenoids was greatest in tetrahydrofuran, while hexane exhibited the least solubility for lutein; methanol and acetonitrile exhibited the least solubility for beta-carotene. Stability was monitored for 10 days at room temperature by measuring absorbance changes at the wavelength maximum. In the majority of the solvents, initial absorbance decreased by less than 10% during the 10-day period. Degradation was greatest for both carotenoids in cyclohexanone. The relative absorptivities were determined by calculating the carotenoid concentration in a reference solvent using a reference absorptivity, and then Beer's Law was applied to the measured absorbance of the same carotenoid concentration in other organic solvents. Absorbance maxima and relative absorptivities were in good agreement with available literature values. C1 UNIV MARYLAND,NUTR SCI PROGRAM,COLLEGE PK,MD 20742. RP CRAFT, NE (reprint author), NATL INST STAND & TECHNOL,CHEM SCI & TECHNOL LAB,DIV ORGAN ANALYT RES,GAITHERSBURG,MD 20899, USA. NR 15 TC 153 Z9 166 U1 3 U2 62 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 SN 0021-8561 J9 J AGR FOOD CHEM JI J. Agric. Food Chem. PD MAR PY 1992 VL 40 IS 3 BP 431 EP 434 DI 10.1021/jf00015a013 PG 4 WC Agriculture, Multidisciplinary; Chemistry, Applied; Food Science & Technology SC Agriculture; Chemistry; Food Science & Technology GA HK054 UT WOS:A1992HK05400013 ER PT J AU BENNETT, HS LOWNEY, JR AF BENNETT, HS LOWNEY, JR TI CALCULATED MAJORITY-CARRIER AND MINORITY-CARRIER MOBILITIES IN HEAVILY DOPED SILICON AND COMPARISONS WITH EXPERIMENT SO JOURNAL OF APPLIED PHYSICS LA English DT Article ID ELECTRON-ELECTRON SCATTERING; GAAS; SEMICONDUCTORS; TRANSPORT; HOLE AB As silicon devices approach 0.1-mu-m in size, it will be essential to have accurate values of the majority and minority mobilities of electrons and holes. These mobilities have been calculated in silicon for donor and acceptor densities between 10(17) and 10(20) cm-3. All the important scattering mechanisms have been included. The ionized impurity scattering has been treated with a quantum-mechanical phase-shift analysis. The results are in good agreement with experiment, but predict that the change of minority electron mobility with increasing dopant density should decrease slightly at high dopant densities for a small range of densities. This effect occurs mainly because of the reduction of plasmon scattering. Some recent experiments support these findings. In addition, the ionized impurity scattering rates calculated from the quantum-mechanical phase shifts and those rates calculated from the Born approximation are shown to differ by more than factors of 3. The Born approximation is not valid for low-energy carriers near band extrema. Carrier scattering rates are key input quantities for Monte Carlo calculations of carrier-velocity versus electric-field relations and of simulations of device behavior. Our 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. RP BENNETT, HS (reprint author), NATL INST STAND & TECHNOL,GAITHERSBURG,MD 20899, USA. NR 28 TC 18 Z9 18 U1 2 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 MAR 1 PY 1992 VL 71 IS 5 BP 2285 EP 2296 DI 10.1063/1.351128 PG 12 WC Physics, Applied SC Physics GA HF690 UT WOS:A1992HF69000030 ER PT J AU MULLIN, AS SZAFLARSKI, DM YOKOYAMA, K GERBER, G LINEBERGER, WC AF MULLIN, AS SZAFLARSKI, DM YOKOYAMA, K GERBER, G LINEBERGER, WC TI TRIPLET-STATE SPECTROSCOPY AND PHOTOFRAGMENT DYNAMICS OF N-2(2+) SO JOURNAL OF CHEMICAL PHYSICS LA English DT Article ID TRANSLATIONAL-ENERGY SPECTROSCOPY; CHARGED MOLECULAR-IONS; DIATOMIC-MOLECULES; EMISSION-SPECTRUM; DOUBLE IONIZATION; CARBON-MONOXIDE; ELECTRON-IMPACT; NO2+ DICATION; BOND LENGTH; N+ IONS AB The photofragment spectrum of N2(2+) --> N+ (3P(g)) + N+ (3P(g)) has been studied using a coaxial laser-ion beam spectrometer. Transitions from the excited (3)SIGMA(u)+ (upsilon = 0,1) state of N2(2+) to the predissociative (3)PI(g) (upsilon = 0) state result in two bands with dense rotational structure at 15 300 and 13 100 cm-1. A complete analysis of the 27 rotational branches associated with the (3)PI(g) (upsilon = 0) <-- (3)SIGMA(u)+ (upsilon = 0) transition provides bond lengths and spectroscopic constants for both states. A perturbation is observed in the (0,0) band, caused by the interaction of (3)SIGMA(u)+ (upsilon = 0) with (3)PI(u) (upsilon almost-equal-to 10). From a deperturbation analysis, the coupling constants and the energy difference between the (3)PI(u) (upsilon almost-equal-to 10) and (3)SIGMA(u)+ (upsilon = 0) states are determined-xi = 1.5 +/- 0.1 cm-1, eta = 0.220 +/- 0.003 cm-1, and T(pert) = 365 +/- 25 cm-1. A broad unstructured band at 16 400 cm-1 arises from a transition out of upsilon = 0 in the (3)SIGMA(u)+ state into a very short-lived upsilon = 1 level of the (3)PI(g) state. Vibrational spacings between upsilon = 0 and upsilon = 1 in both electronic states are determined-(3)SIGMA(u)+ omega(0) = 2210 +/- 20 cm-1 and (3)PI(g) omega(0) almost-equal-to 1100 cm-1. The fragmentation of N2(2+) is explored by measuring the dependence of predissociation lifetimes on the rotational quantum number of the (3)PI(g) (upsilon = 0) state. Experimentally determined lifetimes of 50-70 ps for N' = 2-17 are almost independent of N' and indicate that the predissociation occurs by the interaction of (3)PI(g) (upsilon = 0) with the (3)SIGMA(g)- continuum rather than by tunneling through the (3)PI(g) barrier. C1 NATL INST STAND & TECHNOL,BOULDER,CO 80309. UNIV COLORADO,JOINT INST LAB ASTROPHYS,BOULDER,CO 80309. RP MULLIN, AS (reprint author), UNIV COLORADO,DEPT CHEM & BIOCHEM,BOULDER,CO 80309, USA. RI Mullin, Amy/C-4099-2009 NR 67 TC 44 Z9 44 U1 1 U2 4 PU AMER INST PHYSICS PI WOODBURY PA CIRCULATION FULFILLMENT DIV, 500 SUNNYSIDE BLVD, WOODBURY, NY 11797-2999 SN 0021-9606 J9 J CHEM PHYS JI J. Chem. Phys. PD MAR 1 PY 1992 VL 96 IS 5 BP 3636 EP 3648 DI 10.1063/1.461917 PG 13 WC Chemistry, Physical; Physics, Atomic, Molecular & Chemical SC Chemistry; Physics GA HG953 UT WOS:A1992HG95300033 ER PT J AU CALLANAN, JE MCDERMOTT, KM WEIR, RD WESTRUM, EF AF CALLANAN, JE MCDERMOTT, KM WEIR, RD WESTRUM, EF TI COMPARISON OF HEAT-CAPACITIES MEASURED BY ADIABATIC CALORIMETRY AND BY SCANNING CALORIMETRY - THERMODYNAMIC PROPERTIES OF 9-METHYLCARBAZOLE AT TEMPERATURES BETWEEN 4-K AND 345-K SO JOURNAL OF CHEMICAL THERMODYNAMICS LA English DT Article ID STANDARD; FUSION; 100-K C1 ROYAL MIL COLL CANADA,DEPT CHEM & CHEM ENGN,KINGSTON K7K 5L0,ONTARIO,CANADA. UNIV MICHIGAN,DEPT CHEM,ANN ARBOR,MI 48109. RP CALLANAN, JE (reprint author), NATL INST STAND & TECHNOL,CTR CHEM TECHNOL,BOULDER,CO 80303, USA. NR 32 TC 8 Z9 8 U1 0 U2 0 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 MAR PY 1992 VL 24 IS 3 BP 233 EP 243 DI 10.1016/S0021-9614(05)80065-5 PG 11 WC Thermodynamics; Chemistry, Physical SC Thermodynamics; Chemistry GA HG538 UT WOS:A1992HG53800002 ER PT J AU MILLY, PCD AF MILLY, PCD TI POTENTIAL EVAPORATION AND SOIL-MOISTURE IN GENERAL-CIRCULATION MODELS SO JOURNAL OF CLIMATE LA English DT Article ID ATMOSPHERIC VARIABILITY; CLIMATE SENSITIVITY; SUMMER DRYNESS; CO2; INCREASE; WETNESS; LAYER AB The parameterization of continental evaporation in many atmospheric general circulation models (GCMs) used for simulation of climate is demonstrably inconsistent with the empirical work upon which the parameterization is based. In the turbulent transfer relation for potential evaporation, the climate models employ the modeled actual temperature to evaluate the saturated surface humidity, whereas the consistent temperature is the one reflecting cooling by the hypothetical potential evaporation. A simple theoretical analysis and some direct computations, all ignoring atmospheric feedbacks, indicate that whenever the soil moisture is limited, GCM-based climate models produce rates of potential evaporation that exceed, by a factor of two or more, the rates that would be yielded by use of the consistent temperature. Further approximate analyses and supporting numerical simulations indicate that the expected value of dry-season soil moisture has a short memory relative to the annual cycle and that dry-season evaporation is therefore nearly equal to dry-season precipitation. When potential evaporation is overestimated, it follows that the soil moisture is artificially reduced by a similar factor, and actual evaporation may or may not be overestimated, depending on other details of the hydrologic parameterization. These arguments, advanced on theoretical grounds, explain the substantial, systematic differences between GCM-generated and observation-based estimates of potential evaporation rates and call into question the direct use of currently available GCM-generated values of potential evaporation in the assessment of the effects of climatic change on continental hydrology and water resources. They also provide a partial explanation of the excessively low values of summer soil moisture in GCMs and raise questions concerning the results of studies of soil-moisture changes induced by an increase of greenhouse gases. Nevertheless, an approximate analytical result suggests that the basic dependence of changes in soil moisture on changes in the atmospheric state was qualitatively preserved in those studies. RP MILLY, PCD (reprint author), PRINCETON UNIV, NOAA, US GEOL SURVEY, GEOPHYS FLUID DYNAM LAB, POB 308, PRINCETON, NJ 08542 USA. NR 43 TC 72 Z9 86 U1 0 U2 5 PU AMER METEOROLOGICAL SOC PI BOSTON PA 45 BEACON ST, BOSTON, MA 02108-3693 USA SN 0894-8755 J9 J CLIMATE JI J. Clim. PD MAR PY 1992 VL 5 IS 3 BP 209 EP 226 DI 10.1175/1520-0442(1992)005<0209:PEASMI>2.0.CO;2 PG 18 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA HP486 UT WOS:A1992HP48600002 ER PT J AU BUSHNELL, PG BRILL, RW AF BUSHNELL, PG BRILL, RW TI OXYGEN-TRANSPORT AND CARDIOVASCULAR-RESPONSES IN SKIPJACK TUNA (KATSUWONUS-PELAMIS) AND YELLOWFIN TUNA (THUNNUS-ALBACARES) EXPOSED TO ACUTE-HYPOXIA SO JOURNAL OF COMPARATIVE PHYSIOLOGY B-BIOCHEMICAL SYSTEMIC AND ENVIRONMENTAL PHYSIOLOGY LA English DT Article DE HYPOXIA; CARDIOVASCULAR; OXYGEN TRANSPORT; SKIPJACK TUNA KATSUWONUS-PELAMIS; YELLOWFIN TUNA, THUNNUS-ALBACARES ID TROUT SALMO-GAIRDNERI; DOGFISH SCYLIORHINUS-CANICULA; RAINBOW-TROUT; GAS-EXCHANGE; BLOOD-FLOW; FISH GILLS; HEART-RATE; CARDIAC-OUTPUT; GADUS-MORHUA; OPHIODON-ELONGATUS AB Responses to acute hypoxia were measured in skipjack tuna (Katsuwonus pelamis) and yellowfin tuna (Thunnus albacures) (almost-equal-to 1-3 kg body weight). Fish were prevented from making swimming movements by a spinal injection of lidocaine and were placed in front of a seawater delivery pipe to provide ram ventilation of the gills. Fish could set their own ventilation volumes by adjusting mouth gape. Heart rate, dorsal and ventral aortic blood pressures, and cardiac output were continuously monitored during normoxia (inhalant water (PO2 > 150 mmHg) and three levels of hypoxia (inhalant water PO2 almost-equal-to 130, 90, and 50 mmHg). Water and blood samples were taken for oxygen measurements in fluids afferent and efferent to the gills. From these data, various measures of the effectiveness of oxygen transfer, and branchial and systemic vascular resistance were calculated. Despite high ventilation volumes (4-71.min-1.kg-1), tunas extract approximately 50% of the oxygen from the inhalant water, in part because high cardiac outputs (115-132 ml.min-1.kg-1) result in ventilation/perfusion conductance ratios (0.75-1.1) close to the theoretically ideal value of 1.0. Therefore, tunas have oxygen transfer factors (ml O2.min-1.mmHg-1.kg-1) that are 10-50 times greater than those of other fishes. The efficiency of oxygen transfer from water in tunas (almost-equal-to 65%) matches that measured in teleosts with ventilation volumes an order of magnitude lower. The high oxygen transfer factors of tunas are made possible, in part, by a large gill surface area; however, this appears to carry a considerable osmoregulatory cost as the metabolic rate of gills may account for up 70% of the total metabolism in spinally blocked (i.e., non-swimming) fish. During hypoxia, skipjack and yellowfin tunas show a decrease in heart rate and increase in ventilation volume, as do other teleosts. However, in tunas hypoxic bradycardia is not accompanied by equivalent increases in stroke volume, and cardiac output falls as RR decreases. In both tuna species, oxygen consumption eventually must be maintained by drawing on substantial venous oxygen reserves. This occurs at a higher inhalant water PO2 (between 130 and 90 mmHg) in skipjack tuna than in yellowfin tuna (between 90 and 50 mmHg). The need to draw on venous oxygen reserves would make it difficult to meet the oxygen demand of increasing swimming speed, which is a common response to hypoxia in both species. Because yellowfin tuna can maintain oxygen consumption at a seawater oxygen tension of 90 mmHg without drawing on venous oxygen reserves, they could probably survive for extended periods at this level of hypoxia. C1 NOAA,NATL MARINE FISHERIES SERV,SW FISHERIES SCI CTR,HONOLULU LAB,2570 DOLE ST,HONOLULU,HI 96822. UNIV HAWAII,JOHN A BURNS SCH MED,DEPT PHYSIOL,HONOLULU,HI 96822. NR 84 TC 74 Z9 74 U1 3 U2 15 PU SPRINGER VERLAG PI NEW YORK PA 175 FIFTH AVE, NEW YORK, NY 10010 SN 0174-1578 J9 J COMP PHYSIOL B JI J. Comp. Physiol. B-Biochem. Syst. Environ. Physiol. PD MAR PY 1992 VL 162 IS 2 BP 131 EP 143 DI 10.1007/BF00398338 PG 13 WC Physiology; Zoology SC Physiology; Zoology GA HJ081 UT WOS:A1992HJ08100005 PM 1592908 ER PT J AU STANSBURY, JW AF STANSBURY, JW TI SYNTHESIS AND EVALUATION OF NOVEL MULTIFUNCTIONAL OLIGOMERS FOR DENTISTRY SO JOURNAL OF DENTAL RESEARCH LA English DT Article ID COMPOSITES AB A new type of multifunctional oligomer was synthesized, and its potential as a base monomer in dental composite formulations was evaluated. The oligomer of ethoxylated bis-phenol A diacrylate (OEBPA) was prepared in good yield by a formaldehyde insertion/condensation reaction. Although double bonds along the oligomer backbone are arranged in pairs such that cyclopolymerization is possible, it is not presently known whether this process plays a significant role in the polymerization. Indirect evidence supporting efficient cyclopolymerization involves the reduced polymerization shrinkage observed for polymerized OEBPA relative to polymers of other monomers used as base resins. Photo-cured composites containing either OEBPA, BIS-GMA, or ethoxylated bis-phenol A dimethacrylate (EBPADM) as base resin and TEGDMA as diluent were compared. While the resulting diametral tensile and transverse strengths did not differ significantly, the values for the energy absorbed to failure indicated that the OEBPA- and EBPADM-based formulations yielded composites with somewhat greater toughness than that of the BIS-GMA material. This multifunctional oligomer offers mechanical strength and conversion values that are comparable with those of existing base resin monomers while providing an approximate 30% reduction in polymerization shrinkage. RP STANSBURY, JW (reprint author), NATL INST STAND & TECHNOL,DIV POLYMERS,DENT & MED MAT GRP,GAITHERSBURG,MD 20899, USA. FU NIDCR NIH HHS [Y01-DE 30001] NR 15 TC 41 Z9 43 U1 1 U2 7 PU AMER ASSOC DENTAL RESEARCH PI ALEXANDRIA PA 1619 DUKE ST, ALEXANDRIA, VA 22314 SN 0022-0345 J9 J DENT RES JI J. Dent. Res. PD MAR PY 1992 VL 71 IS 3 BP 434 EP 437 DI 10.1177/00220345920710030201 PG 4 WC Dentistry, Oral Surgery & Medicine SC Dentistry, Oral Surgery & Medicine GA HT695 UT WOS:A1992HT69500002 PM 1533403 ER PT J AU CHOW, LC TAKAGI, S SHIH, S AF CHOW, LC TAKAGI, S SHIH, S TI EFFECT OF A 2-SOLUTION FLUORIDE MOUTHRINSE ON REMINERALIZATION OF ENAMEL LESIONS INVITRO SO JOURNAL OF DENTAL RESEARCH LA English DT Article ID PLAQUE; CARIES; DENTIFRICE; INVIVO; PROGRESSION AB A previous study showed that a two-solution fluoride (F) rinse deposited significantly more loosely-bound F on the tooth surface than did a sodium fluoride (NaF) rinse with the same F concentration (12 mmol/L). In the present study, this experimental rinse was evaluated for its ability to cause remineralization of enamel lesions in an in vitro pH-cycling model. Caries-like lesions were formed in the enamel of extracted human molars by means of a pH 4 demineralizing solution. Fifty-one almost-equal-to 120-mu-m-thick sections containing lesions were randomly divided into (1) control, (2) NaF rinse, and (3) two-solution F rinse groups. With the cut surfaces protected, the control samples were immersed in a pH 7 remineralizing solution for 12 days, and twice daily the sections were also exposed to a pH 4 demineralizing solution for 30 min. Samples in the NaF group received an additional one-minute rinse with a NaF (12 mmol/L) solution twice daily. Samples in the two-solution rinse group received the rinse treatment with a 12 mmol/L F solution prepared by combination of a Na2SiF6 and phosphate-containing solution with a calcium solution just before use. The mineral contents of the lesions were assessed by quantitative microradiography. The results showed that (1) no significant de- or remineralization was detected in the controls; (2) a 46% decrease in mineral loss (DELTA-Z) of the lesion was produced by the NaF rinses; and (3) a 94% decrease in DELTA-Z and a 20-mu-m-thick, mineral-dense surface-coating were produced by the two-solution F rinse treatment. RP CHOW, LC (reprint author), NATL INST STAND & TECHNOL,AMER DENT ASSOC HLTH FDN,PAFFENBARGER RES CTR,DIV POLYMERS,GAITHERSBURG,MD 20899, USA. FU NIDCR NIH HHS [DE05354] NR 26 TC 29 Z9 29 U1 0 U2 1 PU AMER ASSOC DENTAL RESEARCH PI ALEXANDRIA PA 1619 DUKE ST, ALEXANDRIA, VA 22314 SN 0022-0345 J9 J DENT RES JI J. Dent. Res. PD MAR PY 1992 VL 71 IS 3 BP 443 EP 447 DI 10.1177/00220345920710030401 PG 5 WC Dentistry, Oral Surgery & Medicine SC Dentistry, Oral Surgery & Medicine GA HT695 UT WOS:A1992HT69500004 PM 1315346 ER PT J AU VOGEL, GL MAO, Y CAREY, CM CHOW, LC TAKAGI, S AF VOGEL, GL MAO, Y CAREY, CM CHOW, LC TAKAGI, S TI INVIVO FLUORIDE CONCENTRATIONS MEASURED FOR 2 HOURS AFTER A NAF OR A NOVEL 2-SOLUTION RINSE SO JOURNAL OF DENTAL RESEARCH LA English DT Article ID HUMAN DENTAL PLAQUE; ENAMEL; CARIES AB The concentrations of fluoride in various samples from the oral environment were measured at timed intervals after a novel rinse or a NaF rinse, both containing a total of 12 mmol/L (228 ppm) fluoride. The novel rinse consisted of two solutions mixed just before application: Part A contained calcium chloride and sodium acetate; part B contained a hydrolyzable source of fluoride (sodium hexafluorosilicate) and sodium phosphate. Samples were obtained as follows: Single-site plaque-fluid samples were obtained by centrifugation of first-molar plaque; pooled whole-plaque samples were collected from second molars; centrifuged, pooled whole-saliva was collected by vacuum. All samples were analyzed by micro-analytical methods. Results showed that, compared with NaF, the two-solution rinse produced significantly higher salivary fluoride concentrations, plaque-fluid fluoride concentrations, and acid-extractable fluoride in the whole plaque by factors of about 4, 2, and 6, respectively, at 120 min. The results of this study suggest that the new rinse may provide a greater cariostatic effect at the same fluoride dosage than does a NaF rinse. RP VOGEL, GL (reprint author), NATL INST STAND & TECHNOL,AMER DENT ASSOC HLTH FDN,PAFFENBARGER RES CTR,DIV POLYMERS,GAITHERSBURG,MD 20899, USA. FU NIDCR NIH HHS [DE04385, DE05354] NR 26 TC 35 Z9 37 U1 0 U2 2 PU AMER ASSOC DENTAL RESEARCH PI ALEXANDRIA PA 1619 DUKE ST, ALEXANDRIA, VA 22314 SN 0022-0345 J9 J DENT RES JI J. Dent. Res. PD MAR PY 1992 VL 71 IS 3 BP 448 EP 452 DI 10.1177/00220345920710030501 PG 5 WC Dentistry, Oral Surgery & Medicine SC Dentistry, Oral Surgery & Medicine GA HT695 UT WOS:A1992HT69500005 PM 1573075 ER PT J AU COFFEY, HE AF COFFEY, HE TI GEOMAGNETIC AND SOLAR DATA SO JOURNAL OF GEOPHYSICAL RESEARCH-SPACE PHYSICS LA English DT Article RP COFFEY, HE (reprint author), NOAA,WORLD DATA CTR A SOLAR TERR PHYS,BOULDER,CO 80303, USA. NR 0 TC 0 Z9 0 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 MAR 1 PY 1992 VL 97 IS A3 BP 3229 EP 3230 DI 10.1029/92JA00203 PG 2 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA HG749 UT WOS:A1992HG74900038 ER PT J AU KELLY, JF RITTER, JJ AF KELLY, JF RITTER, JJ TI COMPOSITIONAL HOMOGENEITY IN PROCESSING PRECURSOR POWDERS TO THE BA2YCU3O7-X HIGH-TC SUPERCONDUCTOR SO JOURNAL OF MATERIALS RESEARCH LA English DT Article ID OXIDE SUPERCONDUCTORS AB We have used scanning electron microscopy (SEM) and energy dispersive x-ray spectroscopy (EDS) to study compositional homogeneity at several stages in the processing of powders to the Ba2yCu3Ox high T(c) superconductor. We investigated the effects of solution pH and ionic concentration in the precipitation preparation of mixed hydroxycarbonates of Ba, Y, and Cu as precursor to the Ba2yCu3O7-x high T(c) superconductor. Our results show that both powder homogeneity and particle morphology are strongly dependent on these parameters. Additionally, studies of the compacted powders by EDS mapping at successive stages of processing show the development of phase inhomogeneities even in homogeneous starting powders. RP KELLY, JF (reprint author), NATL INST STAND & TECHNOL,DIV CERAM,GAITHERSBURG,MD 20899, USA. NR 13 TC 1 Z9 1 U1 0 U2 1 PU MATERIALS RESEARCH SOCIETY PI PITTSBURGH PA 9800 MC KNIGHT ROAD SUITE 327, PITTSBURGH, PA 15237 SN 0884-2914 J9 J MATER RES JI J. Mater. Res. PD MAR PY 1992 VL 7 IS 3 BP 580 EP 584 DI 10.1557/JMR.1992.0580 PG 5 WC Materials Science, Multidisciplinary SC Materials Science GA HH520 UT WOS:A1992HH52000010 ER PT J AU MAKI, AG WELLS, JS AF MAKI, AG WELLS, JS TI MEASUREMENT AND ANALYSIS OF THE FERMI RESONANCE BETWEEN NU-5 AND 2-NU-9 OF NITRIC-ACID SO JOURNAL OF MOLECULAR SPECTROSCOPY LA English DT Article ID HETERODYNE FREQUENCY MEASUREMENTS; ROTATIONAL STRUCTURE; MOLECULAR-CONSTANTS; INFRARED-SPECTRUM; 898 CM-1; HNO3; BAND; SPECTROSCOPY; OCS C1 NATL INST STAND & TECHNOL,DIV MOLEC SPECT,GAITHERSBURG,MD 20899. NATL INST STAND & TECHNOL,DIV TIME & FREQUENCY,BOULDER,CO 80303. NR 22 TC 36 Z9 36 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 MAR PY 1992 VL 152 IS 1 BP 69 EP 79 DI 10.1016/0022-2852(92)90117-7 PG 11 WC Physics, Atomic, Molecular & Chemical; Spectroscopy SC Physics; Spectroscopy GA HE082 UT WOS:A1992HE08200007 ER PT J AU BLOM, CE HEDDERICH, HG LOVAS, FJ SUENRAM, RD MAKI, AG AF BLOM, CE HEDDERICH, HG LOVAS, FJ SUENRAM, RD MAKI, AG TI INFRARED AND MICROWAVE-SPECTRA OF SRO AND BAO SO JOURNAL OF MOLECULAR SPECTROSCOPY LA English DT Article ID ELECTRIC-DIPOLE MOMENT; DUNHAM COEFFICIENTS; METAL-OXIDES; GAS-PHASE; DEPENDENCE; CAO C1 UNIV WASHINGTON,DEPT CHEM,SEATTLE,WA 98195. UNIV GIESSEN,INST PHYS CHEM,W-6300 GIESSEN,GERMANY. NATL INST STAND & TECHNOL,DIV MOLEC PHYS,GAITHERSBURG,MD 20899. NR 33 TC 18 Z9 18 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 MAR PY 1992 VL 152 IS 1 BP 109 EP 118 DI 10.1016/0022-2852(92)90121-4 PG 10 WC Physics, Atomic, Molecular & Chemical; Spectroscopy SC Physics; Spectroscopy GA HE082 UT WOS:A1992HE08200011 ER PT J AU LOVAS, FJ AF LOVAS, FJ TI RECOMMENDED REST FREQUENCIES FOR OBSERVED INTERSTELLAR MOLECULAR MICROWAVE TRANSITIONS - 1991 REVISION SO JOURNAL OF PHYSICAL AND CHEMICAL REFERENCE DATA LA English DT Article DE HYPERFINE STRUCTURE; INTERSTELLAR MOLECULES; MICROWAVE SPECTRA; MOLECULAR; RADIO ASTRONOMY; ROTATIONAL SPECTRA; SPECTRA AB Critically evaluated transition frequencies for the molecular transitions detected in interstellar and circumstellar clouds are presented. The tabulated transitions are recommended for reference in future astronomical observations in the microwave and millimeter wavelength regions. The transition frequencies have been selected through a critical examination and analysis of the laboratory spectral data obtained from the literature. The information tabulated includes the species identity, transition frequency, uncertainty, and quantum state labels. In addition, representative line antenna temperatures are listed for a typical astronomical source for each transition as a convenience to users, and the references are cited for the laboratory and astronomical literature which have been employed. RP LOVAS, FJ (reprint author), NATL INST STAND & TECHNOL,DIV MOLEC PHYS,GAITHERSBURG,MD 20899, USA. NR 0 TC 169 Z9 170 U1 0 U2 2 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 SN 0047-2689 J9 J PHYS CHEM REF DATA JI J. Phys. Chem. Ref. Data PD MAR-APR PY 1992 VL 21 IS 2 BP 181 EP 272 PG 92 WC Chemistry, Multidisciplinary; Chemistry, Physical; Physics, Multidisciplinary SC Chemistry; Physics GA HK718 UT WOS:A1992HK71800001 ER PT J AU WIESE, WL KONJEVIC, N AF WIESE, WL KONJEVIC, N TI REGULARITIES IN EXPERIMENTAL STARK SHIFTS SO JOURNAL OF QUANTITATIVE SPECTROSCOPY & RADIATIVE TRANSFER LA English DT Article ID SINGLY IONIZED SILICON; SPECTRAL-LINES; ANALOGOUS TRANSITIONS; SYSTEMATIC TRENDS; PERIOD 1976; WIDTHS; PLASMA; PARAMETERS; ATOMS AB We have examined regularities in plasma-produced line shifts (Stark shifts) by a comprehensive analysis of literature data. Since the shifts are the result of atomic collision processes, regularities are expected from general atomic structure considerations. Specifically, systematic behavior should occur for spectral series and for corresponding transitions in homologous atoms and isoelectronic ions. Also, Stark shifts should be similar for lines within multiplets and, to a lesser degree, within supermultiplets and transition arrays. Numerous examples show conclusively that the measured data exhibit these predicted regularities. When pronounced irregularities occur, they are readily explainable in terms of special circumstances in the atomic structure. C1 INST PHYS,YU-11001 BELGRADE,YUGOSLAVIA. UNIV BELGRADE,FAC PHYS,YU-11001 BELGRADE,YUGOSLAVIA. RP WIESE, WL (reprint author), NATL INST STAND & TECHNOL,GAITHERSBURG,MD 20899, USA. NR 42 TC 53 Z9 53 U1 0 U2 1 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD, ENGLAND OX5 1GB SN 0022-4073 J9 J QUANT SPECTROSC RA JI J. Quant. Spectrosc. Radiat. Transf. PD MAR PY 1992 VL 47 IS 3 BP 185 EP 200 DI 10.1016/0022-4073(92)90028-3 PG 16 WC Optics; Spectroscopy SC Optics; Spectroscopy GA HJ005 UT WOS:A1992HJ00500004 ER PT J AU LEVIN, BC ALARIE, Y STOCK, MF SCHILLER, SB AF LEVIN, BC ALARIE, Y STOCK, MF SCHILLER, SB TI THE DEVELOPMENT OF A STANDARD REFERENCE MATERIAL FOR CALIBRATION OF THE UNIVERSITY-OF-PITTSBURGH SMOKE TOXICITY METHOD FOR ASSESSING THE ACUTE INHALATION TOXICITY OF COMBUSTION PRODUCTS SO JOURNAL OF RESEARCH OF THE NATIONAL INSTITUTE OF STANDARDS AND TECHNOLOGY LA English DT Article DE COMBUSTION; COMBUSTION PRODUCTS; INHALATION; NYLON; NYLON 6/6; SRM; STANDARD REFERENCE MATERIAL; TOXICITY TESTS; UNIVERSITY-OF-PITTSBURGH ID THERMAL-DECOMPOSITION PRODUCTS; POTENTIAL TOXICITY; NATURAL POLYMERS; BURNING POLYMERS; DOUGLAS-FIR AB A standard reference material (SRM 1049) has been developed for the University of Pittsburgh smoke toxicity method. SRM 1049 is a nylon 6/6 and has the molecular structure of [-NH(CH2)6NHCO(CH2)4CO-]n. This SRM is for calibrating the apparatus and providing confidence that the method is being conducted in a correct manner and that the equipment is functioning properly. The certified figure of merit is a LC50 value plus its 95% prediction interval which were calculated and found to be 4.4 + 3.4 g. The 95% prediction interval indicates the range in which the next determined LC50 value would be expected to fall. Thus, if an investigator were to test this SRM under their laboratory conditions according to the specifications of the University of Pittsburgh test procedure and found the LC50 value fell within the certified 95% prediction interval, the probability is good that the test is being conducted correctly. C1 UNIV MARYLAND, DEPT FIRE PROTECT ENGN, COLLEGE PK, MD 20742 USA. UNIV PITTSBURGH, GRAD SCH PUBL HLTH, DEPT ENVIRONM & OCCUPAT HLTH, PITTSBURGH, PA 15261 USA. NBS, COMP & APPL MATH LAB, GAITHERSBURG, MD 20899 USA. RP LEVIN, BC (reprint author), NBS, BLDG & FIRE RES LAB, FIRE HAZARD ANAL GRP, GAITHERSBURG, MD 20899 USA. NR 18 TC 0 Z9 0 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 MAR-APR PY 1992 VL 97 IS 2 BP 245 EP 252 DI 10.6028/jres.097.006 PG 8 WC Instruments & Instrumentation; Physics, Applied SC Instruments & Instrumentation; Physics GA HX645 UT WOS:A1992HX64500001 PM 28053430 ER PT J AU HARTMAN, AW DOIRON, TD FU, J AF HARTMAN, AW DOIRON, TD FU, J TI CERTIFICATION OF NIST SRM 1962 - 3 MU-M DIAMETER POLYSTYRENE SPHERES SO JOURNAL OF RESEARCH OF THE NATIONAL INSTITUTE OF STANDARDS AND TECHNOLOGY LA English DT Article DE ELECTRON MICROSCOPY; MICROSPHERES; OPTICAL MICROSCOPY; PARTICLE SIZING; POLYSTYRENE; STANDARD REFERENCE MATERIALS ID ARRAY AB This report describes the certification of SRM 1962, a NIST Standard Reference Material for particle diameter. It consists of an aqueous suspension of monosize 3-mu-m polystyrene spheres. Two calibration techniques were used: optical microscopy and electron microscopy. The first one gave a mean diameter of DBAR = 2.977 +/- 0.011-mu-m and a standard deviation of the size distribution sigma(D) = 0.020-mu-m, based on measurement of 4600 spheres. The second technique gave DBAR = 2.990 +/- 0.009-mu-m, based on measurement of 120 spheres. The reported value covering the two results is DBAR = 2.983-mu-m with a maximum uncertainty of 0.016-mu-m, with sigma(D) = 0.020-mu-m. RP HARTMAN, AW (reprint author), NBS, DIV PRECIS ENGN, GAITHERSBURG, MD 20899 USA. NR 8 TC 10 Z9 12 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 MAR-APR PY 1992 VL 97 IS 2 BP 253 EP 265 DI 10.6028/jres.097.007 PG 13 WC Instruments & Instrumentation; Physics, Applied SC Instruments & Instrumentation; Physics GA HX645 UT WOS:A1992HX64500002 PM 28053431 ER PT J AU GEIST, J BELZER, B MILLER, ML ROITMAN, P AF GEIST, J BELZER, B MILLER, ML ROITMAN, P TI OPTICAL CALIBRATION OF A SUBMICROMETER MAGNIFICATION STANDARD SO JOURNAL OF RESEARCH OF THE NATIONAL INSTITUTE OF STANDARDS AND TECHNOLOGY LA English DT Article DE CALIBRATION; ELECTRON MICROSCOPE; MAGNIFICATION STANDARD; SCANNING ELECTRON MICROSCOPE; TRANSMISSION ELECTRON MICROSCOPE ID SILICON AB The calibration of a new submicrometer magnification standard for electron microscopes is described. The new standard is based on the width of a thin thermal-oxide film sandwiched between a silicon single-crystal substrate and a polysilicon capping layer. The calibration is based on an ellipsometric measurement of the oxide thickness before the polysilicon layer is deposited on the oxide. The uncertainty in the derivation of a thickness for the layer from the ellipsometric parameters is also derived. RP GEIST, J (reprint author), NBS, DIV SEMICOND ELECTR, ELECTR & ELECT ENGN LAB, GAITHERSBURG, MD 20899 USA. NR 13 TC 4 Z9 5 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 MAR-APR PY 1992 VL 97 IS 2 BP 267 EP 272 DI 10.6028/jres.097.008 PG 6 WC Instruments & Instrumentation; Physics, Applied SC Instruments & Instrumentation; Physics GA HX645 UT WOS:A1992HX64500003 PM 28053432 ER PT J AU MUTH, LA AF MUTH, LA TI PROBE-POSITION ERROR CORRECTION IN PLANAR NEAR-FIELD MEASUREMENTS AT 60 GHZ - EXPERIMENTAL-VERIFICATION SO JOURNAL OF RESEARCH OF THE NATIONAL INSTITUTE OF STANDARDS AND TECHNOLOGY LA English DT Article DE ERROR CORRECTION; EXPERIMENTAL VERIFICATION; PLANAR NEAR FIELDS; PROBE-POSITION ERRORS AB This study was conducted to verify that the probe-position error correction can be successfully applied to real data obtained on a planar near-field range where probe position errors are known. Since probe position-error correction is most important at high frequencies, measurements were made at 60 GHz. Six planar scans at z positions separated by 0.03-lambda were obtained. The correction technique was applied to an error-contaminated near field constructed out of the six scans according to a discretized periodic error function. The results indicate that probe position errors can be removed from real near-field data as successfully as from simulated data; some residual errors, which are thought to be due to multiple reflections, residual drift in the measurement system, and residual probe position errors in all three coordinates, are observed. RP MUTH, LA (reprint author), NBS, ELECTR & ELECT ENGN LAB, DIV ELECTROMAGNET FIELDS, BOULDER, CO 80303 USA. NR 7 TC 1 Z9 1 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 MAR-APR PY 1992 VL 97 IS 2 BP 273 EP 297 DI 10.6028/jres.097.009 PG 25 WC Instruments & Instrumentation; Physics, Applied SC Instruments & Instrumentation; Physics GA HX645 UT WOS:A1992HX64500004 PM 28053433 ER PT J AU WILLIAMS, ER GHOSH, RN MARTINIS, JM AF WILLIAMS, ER GHOSH, RN MARTINIS, JM TI MEASURING THE ELECTRONS CHARGE AND THE FINE-STRUCTURE CONSTANT BY COUNTING ELECTRONS ON A CAPACITOR SO JOURNAL OF RESEARCH OF THE NATIONAL INSTITUTE OF STANDARDS AND TECHNOLOGY LA English DT Article DE CALCULABLE CAPACITOR; COULOMB BLOCKADE; ELECTRON CHARGE; ELECTRON COUNTING; FINE-STRUCTURE CONSTANT; SINGLE ELECTRON TUNNELING ID SMALL TUNNEL-JUNCTIONS; SINGLE; TIME AB The charge of the electron can be determined by simply placing a known number of electrons on one electrode of a capacitor and measuring the voltage, V(s), across the capacitor. If V(s) is measured in terms of the Josephson volt and the capacitor is measured in SI units then the fine-structure constant is the quantity determined. Recent developments involving single electron tunneling, SET, have shown how to count the electrons as well as how to make an electrometer with sufficient sensitivity to measure the charge. C1 NBS, DIV ELECTROMAGNET TECHNOL, BOULDER, CO 80303 USA. RP WILLIAMS, ER (reprint author), NBS, DIV ELECT, GAITHERSBURG, MD 20899 USA. NR 14 TC 44 Z9 44 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 MAR-APR PY 1992 VL 97 IS 2 BP 299 EP 304 DI 10.6028/jres.097.010 PG 6 WC Instruments & Instrumentation; Physics, Applied SC Instruments & Instrumentation; Physics GA HX645 UT WOS:A1992HX64500005 PM 28053434 ER PT J AU CHUANG, TJ FULLER, ER AF CHUANG, TJ FULLER, ER TI EXTENDED CHARLES-HILLIG THEORY FOR STRESS-CORROSION CRACKING OF GLASS SO JOURNAL OF THE AMERICAN CERAMIC SOCIETY LA English DT Article AB The work originally performed by Charles and Hillig (C & H) on the chemical stress corrosion cracking of glass is based on the chemical reaction rate theory and restricts the analysis to only the kinetic change at the exact location of the crack tip. As a result, crack sharpening/blunting is predicted when the applied stress lies above/below the static fatigue limit. The present paper extends the investigation within the same physical framework to the geometric change of the entire cavity surface, particularly in the vicinity of the cavity apex region. It has been found that a physical-property-dependent parameter (m) exists which exerts a strong influence on the crack-tip morphology. In the case of m = m(th), where m(th) is a threshold m which assumes a value of almost-equal-to 45 for an elliptical cavity having a minor to major axes ratio of 0.01, the current predictions reduce to the C & H results. In general, however, m not-equal m(th), and the single-valued fatigue limit degenerates into a range of applied stresses under which either enhanced blunting (m > m(th)) or necking (m < m(th)) is predicted to take place. Evaluation of m for soda-lime glass reveals that m > 45, suggesting that enhanced blunting takes place at the crack tip when external loads are applied at a moderate level for a typical crack having an initial major to minor axes ratio > 100 in a soda-lime glass specimen. RP CHUANG, TJ (reprint author), NATL INST STAND & TECHNOL,DIV CERAM,GAITHERSBURG,MD 20899, USA. NR 13 TC 33 Z9 33 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 MAR PY 1992 VL 75 IS 3 BP 540 EP 545 DI 10.1111/j.1151-2916.1992.tb07839.x PG 6 WC Materials Science, Ceramics SC Materials Science GA HJ063 UT WOS:A1992HJ06300010 ER PT J AU WAN, KT SMITH, DT LAWN, BR AF WAN, KT SMITH, DT LAWN, BR TI FRACTURE AND CONTACT ADHESION ENERGIES OF MICA MICA, SILICA SILICA, AND MICA SILICA INTERFACES IN DRY AND MOIST ATMOSPHERES SO JOURNAL OF THE AMERICAN CERAMIC SOCIETY LA English DT Article ID SURFACE FORCE MODEL; HYDROPHOBIC INTERACTIONS; CAPILLARY CONDENSATION; INTERMOLECULAR FORCES; MONOMOLECULAR FILMS; MACROSCOPIC BODIES; NONAQUEOUS MEDIA; BRITTLE CRACKS; EXPOSED CRACKS; ELASTIC SOLIDS AB A study is made of the factors that contribute to the energy of mica-mica, silica-silica, and mica-silica interfaces in the presence of moist atmospheres. Energies are measured using brittle fracture and contact adhesion techniques. Both "virgin" and "healed" interfaces are investigated, with special attention on the latter. The fracture and adhesion data overlap, reflecting a common underlying separation process by "sharp-crack propagation." The study identifies several contributors to the interface adhesion energies. At virgin mica-mica and silica-silica interfaces the energy is determined by primary ionic-covalent attraction, and by the screening of this attraction by condensed moisture from the atmosphere. At healed interfaces the energy depends on both environmental interaction and "lattice" coherence. At retracted cracks in mica-mica most of the virgin ionic attraction is retained. On misorienting separated cleavage halves prior to recontact the interaction energy drops substantially: in "dry" atmospheres (relative humidity < 5%) a portion of the Coulombic interaction persists in the form of "macroscopic domains" of electrostatic charge, attributable to long-range order in the cation sublattice; in "wet" atmospheres (relative humidity > 50%) capillary forces dominate. The dissimilar mica-silica system exhibits the same dominance by capillary forces in wet atmospheres. However, in dry atmospheres the adhesion energy becomes inordinately high, from spontaneous transfer of electronic charge from one surface to the other. The implications of these observations concerning mechanical properties of brittle ceramics are discussed. C1 NATL INST STAND & TECHNOL,MAT SCI & ENGN LAB,GAITHERSBURG,MD 20899. NATL INST STAND & TECHNOL,DIV CERAM,GAITHERSBURG,MD 20899. RP WAN, KT (reprint author), UNIV MARYLAND,DEPT PHYS & ASTRON,COLLEGE PK,MD 20742, USA. RI Smith, Douglas/I-4403-2016 OI Smith, Douglas/0000-0002-9358-3449 NR 47 TC 57 Z9 59 U1 1 U2 17 PU AMER CERAMIC SOC PI WESTERVILLE PA 735 CERAMIC PLACE, PO BOX 6136, WESTERVILLE, OH 43081-6136 SN 0002-7820 J9 J AM CERAM SOC JI J. Am. Ceram. Soc. PD MAR PY 1992 VL 75 IS 3 BP 667 EP 676 DI 10.1111/j.1151-2916.1992.tb07857.x PG 10 WC Materials Science, Ceramics SC Materials Science GA HJ063 UT WOS:A1992HJ06300028 ER PT J AU LUNIN, LF HARMAN, D AF LUNIN, LF HARMAN, D TI PERSPECTIVES ON ... HUMAN-COMPUTER INTERFACE - INTRODUCTION AND OVERVIEW SO JOURNAL OF THE AMERICAN SOCIETY FOR INFORMATION SCIENCE LA English DT Editorial Material C1 CORNELL UNIV,MED CTR,COLL MED,DEPT RADIOL,NEW YORK,NY 10021. NIST,GAITHERSBURG,MD 20899. NR 5 TC 0 Z9 0 U1 0 U2 0 PU JOHN WILEY & SONS INC PI NEW YORK PA 605 THIRD AVE, NEW YORK, NY 10158-0012 SN 0002-8231 J9 J AM SOC INFORM SCI JI J. Am. Soc. Inf. Sci. PD MAR PY 1992 VL 43 IS 2 BP 152 EP 154 DI 10.1002/(SICI)1097-4571(199203)43:2<152::AID-ASI7>3.0.CO;2-8 PG 3 WC Computer Science, Information Systems; Information Science & Library Science SC Computer Science; Information Science & Library Science GA HE951 UT WOS:A1992HE95100007 ER PT J AU HARMAN, D AF HARMAN, D TI USER-FRIENDLY SYSTEMS INSTEAD OF USER-FRIENDLY FRONT-ENDS SO JOURNAL OF THE AMERICAN SOCIETY FOR INFORMATION SCIENCE LA English DT Article ID ONLINE CATALOG; SEARCH; RETRIEVAL; TEXT AB Most commercial online retrieval systems are not designed to service end users and, therefore, have often built "front-ends" to their systems specifically to serve the end-user market. These front-ends have not been well accepted, mostly because the underlying systems are still difficult for end users to use successfully in searching. New techniques, based on statistical methods, that allow natural language input and return lists of records in order of likely relevance, have long been available from research laboratories. This article presents four prototype implementations of these statistical retrieval systems that demonstrate their potential as powerful and easily used retrieval systems able to service all users. RP NIST, GAITHERSBURG, MD 20899 USA. NR 26 TC 12 Z9 12 U1 0 U2 0 PU JOHN WILEY & SONS INC PI HOBOKEN PA 111 RIVER ST, HOBOKEN, NJ 07030 USA SN 0002-8231 J9 J AM SOC INFORM SCI JI J. Am. Soc. Inf. Sci. PD MAR PY 1992 VL 43 IS 2 BP 164 EP 174 DI 10.1002/(SICI)1097-4571(199203)43:2<164::AID-ASI9>3.0.CO;2-W PG 11 WC Computer Science, Information Systems; Information Science & Library Science SC Computer Science; Information Science & Library Science GA HE951 UT WOS:A1992HE95100009 ER PT J AU DESALVO, GC TSENG, WF COMAS, J AF DESALVO, GC TSENG, WF COMAS, J TI ETCH RATES AND SELECTIVITIES OF CITRIC ACID/HYDROGEN PEROXIDE ON GAAS, AL0.3GA0.7AS, IN0.2GA0.8AS, IN0.53GA0.47AS, IN0.52AL0.48AS, AND INP SO JOURNAL OF THE ELECTROCHEMICAL SOCIETY LA English DT Article AB Etching studies involving citric acid/hydrogen peroxide (C6H8O7:H2O2) at volume ratios from 0.5:1 to 50:1 were found to provide good selective etching of various III-V semiconductor materials grown on GaAs and InP substrates using molecular beam epitaxy. Both selective and uniform (nonselective) etching regions were found between these material systems by choosing different concentration volume ratios of citric acid/hydrogen peroxide ((chi)C6H8O7:1H2O2). Etchant selectivities, defined as a ratio of the etch rates, for the GaAs-based materials were measured to be as high as 116 for GaAs/As0.3Ga0.7As and 120 for In0.2Ga0.8As/Al0.3Ga0.7As. In addition, the InP system had selectivities of approximately 60 and 100 for In0.53Ga0.47As/In0.52Al0.48As and In0.52Al0.48As/InP, with the highest selectivity of 473 found for In0.53Ga0.47As/InP. The citric acid/hydrogen peroxide system can be used as a stop etch for InP-based devices, as InP is virtually unaffected by this etchant. Finally, citric acid/hydrogen peroxide can be used to preferentially etch these materials through a photoresist mask, since it does not erode photoresist at any volume ratio. RP DESALVO, GC (reprint author), NATL INST STAND & TECHNOL,GAITHERSBURG,MD 20899, USA. RI Schaff, William/B-5839-2009 NR 7 TC 141 Z9 146 U1 2 U2 15 PU ELECTROCHEMICAL SOC INC PI PENNINGTON PA 10 SOUTH MAIN STREET, PENNINGTON, NJ 08534 SN 0013-4651 J9 J ELECTROCHEM SOC JI J. Electrochem. Soc. PD MAR PY 1992 VL 139 IS 3 BP 831 EP 835 DI 10.1149/1.2069311 PG 5 WC Electrochemistry; Materials Science, Coatings & Films SC Electrochemistry; Materials Science GA HH077 UT WOS:A1992HH07700036 ER PT J AU SUGAR, J KAUFMAN, V ROWAN, WL AF SUGAR, J KAUFMAN, V ROWAN, WL TI IMPROVED WAVELENGTHS FOR PROMINENT LINES OF NI-X TO NI-XXVI SO JOURNAL OF THE OPTICAL SOCIETY OF AMERICA B-OPTICAL PHYSICS LA English DT Article ID EXPERIMENTAL LEVEL VALUES; SOLAR SPECTRUM; TRANSITIONS; NICKEL; IONS; IDENTIFICATIONS; CLASSIFICATION; ANGSTROMS AB New measurements of 62 spectral lines of highly ionized Ni ions in the range of 83-320 angstrom have been made with an uncertainty of +/- 0.005 angstrom. The light source was the TEXT tokamak at the University of Texas in Austin. Lines of Li-like to K-like ions are included, along with visually estimated relative intensities, previous measurements, and classifications. The uncertainty of more than half of the previous best measurements is +/- (0.02-0.03) angstrom. 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 25 Z9 26 U1 1 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 MAR PY 1992 VL 9 IS 3 BP 344 EP 346 DI 10.1364/JOSAB.9.000344 PG 3 WC Optics SC Optics GA HG733 UT WOS:A1992HG73300005 ER PT J AU READER, J ACQUISTA, N AF READER, J ACQUISTA, N TI LASER-PRODUCED SPECTRA OF COPPER-LIKE ANTIMONY AND TELLURIUM, SB22+ AND TE23+ SO JOURNAL OF THE OPTICAL SOCIETY OF AMERICA B-OPTICAL PHYSICS LA English DT Article ID CU-LIKE IONS; ENERGY-LEVELS; ISOELECTRONIC SEQUENCE; WAVELENGTHS; RU-15+ AB Spectra of the copperlike ions Sb22+ and Te23+ were observed with a laser-produced plasma and a 10.7-m grazing-incidence spectrograph. Wavelengths, energy levels for all n = 4 and n = 5 configurations, and ionization energies were determined for each ion. For Sb22+ the 6g levels were also determined. Wavelengths for the 4s-4p resonance lines are compared with recent measurements [J. Opt. Soc. Am. B 8, 1799 (1991)] obtained with a tokamak plasma and with semiempirical values [Phys. Rev. A 44, 148 (1991)] obtained from smoothed corrections to relativistic calculations. RP READER, J (reprint author), NATL INST STAND & TECHNOL,GAITHERSBURG,MD 20899, USA. NR 10 TC 3 Z9 3 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 MAR PY 1992 VL 9 IS 3 BP 347 EP 349 DI 10.1364/JOSAB.9.000347 PG 3 WC Optics SC Optics GA HG733 UT WOS:A1992HG73300006 ER PT J AU VANDERPLOEG, HA GARDNER, WS PARRISH, CC LIEBIG, JR CAVALETTO, JF AF VANDERPLOEG, HA GARDNER, WS PARRISH, CC LIEBIG, JR CAVALETTO, JF TI LIPIDS AND LIFE-CYCLE STRATEGY OF A HYPOLIMNETIC COPEPOD IN LAKE-MICHIGAN SO LIMNOLOGY AND OCEANOGRAPHY LA English DT Note ID DIAPTOMUS-SICILIS; ENERGY RESERVES; ZOOPLANKTON; FOOD; TEMPERATURE; LIMITATION AB Concentration and composition of lipids varied seasonally in adult female Diaptomus sicilis, a hypolimnetic suspension-feeding calanoid copepod, in Lake Michigan. Triacyl-glycerol (TG) was the predominant storage lipid; its level remained high (33-40% of dry wt) from June through January. During the period of reproduction from February through May, TG dropped steeply to a low of 9%. The abrupt increase in TG concentration from May to June was probably caused by the recruitment of non-reproducing adult females. Throughout summer and fall ovaries remained unripe. Feeding experiments at satiating food concentrations at 6-degrees and 20-degrees-C suggest that low temperature and the hypolimnion was a major reason that ovaries did not ripen. Stored TG served as a potential buffer to starvation, although starvation conditions did not occur. By remaining in the hypolimnion rather than in the epilimnion, D. sicilis is assured a relatively stable supply of algae, low metabolic rate, and escape from predation. These advantages may have to be weighed against a reproductive bottleneck of low temperature. RP VANDERPLOEG, HA (reprint author), NOAA,GREAT LAKES ENVIRONM RES LAB,2205 COMMONWEALTH BLVD,ANN ARBOR,MI 48105, USA. OI Liebig, James/0000-0002-0433-9066; Vanderploeg, Henry/0000-0003-1358-8475 NR 28 TC 39 Z9 41 U1 0 U2 4 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 MAR PY 1992 VL 37 IS 2 BP 413 EP 424 PG 12 WC Limnology; Oceanography SC Marine & Freshwater Biology; Oceanography GA JD023 UT WOS:A1992JD02300017 ER PT J AU ZHANG, Y PEI, P PEREZ, JM HSU, SM AF ZHANG, Y PEI, P PEREZ, JM HSU, SM TI A NEW METHOD TO EVALUATE DEPOSIT-FORMING TENDENCY OF LIQUID LUBRICANTS BY DIFFERENTIAL SCANNING CALORIMETRY SO LUBRICATION ENGINEERING LA English DT Article ID OXIDATION AB A new laboratory bench test using the technique of pressurized differential scanning calorimetry (PDSC), has been developed to evaluate the deposit-forming tendency of liquid lubricants. This method, called the Two-Peak Method, attempts to simulate the deposit formation mechanism in an engine by heating thin films of oil on steel discs in an oxidative atmosphere. In this paper, the development and optimization of the two-peak test procedure are described. The test was evaluated by characterizing the deposit forming tendencies of five liquid lubricants. The deposit performance ranking for the five oils obtained from this new test method was consistent with engine test ranking. C1 NATL INST STAND & TECHNOL,DIV CERAM,TRIBOL GRP,GAITHERSBURG,MD 20899. NR 10 TC 18 Z9 23 U1 0 U2 0 PU SOC TRIBOLOGISTS & LUBRICATION ENGINEERS PI PARK RIDGE PA 838 BUSSE HIGHWAY, PARK RIDGE, IL 60068 SN 0024-7154 J9 LUBR ENG JI Lubric. Eng. PD MAR PY 1992 VL 48 IS 3 BP 189 EP 195 PG 7 WC Engineering, Mechanical SC Engineering GA HH287 UT WOS:A1992HH28700002 ER PT J AU ZHANG, Y PEREZ, JM PEI, P HSU, SM AF ZHANG, Y PEREZ, JM PEI, P HSU, SM TI THE DEPOSIT FORMING TENDENCIES OF DIESEL-ENGINE OILS CORRELATION BETWEEN THE 2-PEAK METHOD AND ENGINE TESTS SO LUBRICATION ENGINEERING LA English DT Article DE ENGINE DEPOSIT TEST; 2-PEAK METHOD; PRESSURIZED DSC; OIL OXIDATION; LABORATORY BENCH TEST-DEPOSITS; DIESEL ENGINE OILS AB The ability to determine the deposit-forming tendencies of lubricants utilizing a newly developed laboratory bench test method was established using three individual sets of lubricants. The "Two-Peak Method" was developed using a pressurized differential scanning calorimeter (PDSC) and a unique sample pan. The method is described and the repeatability between operators is demonstrated. The oils used in the study were evaluated in either engine oil performance tests or field tests, by the cooperating laboratories. For each set of oils, highly correlatable results between the Two-Peak Method and the engine performance data were obtained. Although engine performance is often a combination of many factors, such as oil consumption, bore-polishing and top-land carbon, a specific correlation was obtained between the Two-Peak Method results and the formation of top-land hard carbon deposits in diesel engines. C1 NATL INST STAND & TECHNOL,DIV CERAM,TRIBOL GRP,GAITHERSBURG,MD 20899. NR 17 TC 8 Z9 8 U1 0 U2 1 PU SOC TRIBOLOGISTS & LUBRICATION ENGINEERS PI PARK RIDGE PA 838 BUSSE HIGHWAY, PARK RIDGE, IL 60068 SN 0024-7154 J9 LUBR ENG JI Lubric. Eng. PD MAR PY 1992 VL 48 IS 3 BP 221 EP 226 PG 6 WC Engineering, Mechanical SC Engineering GA HH287 UT WOS:A1992HH28700005 ER PT J AU GLASER, SD NELSON, PP AF GLASER, SD NELSON, PP TI HIGH-FIDELITY WAVE-FORM DETECTION OF ACOUSTIC EMISSIONS FROM ROCK FRACTURE SO MATERIALS EVALUATION LA English DT Article DE ACOUSTIC EMISSION; FRACTURE; NONDESTRUCTIVE EVALUATION; PATTERN RECOGNITION; ROCK; SIGNAL PROCESSING; SOURCE CHARACTERIZATION; SYSTEM CALIBRATION; WAVE-FORM ANALYSIS AB This paper gives details of an experimental setup, developed at the University of Texas at Austin, which permits quantitative investigation of acoustic emission waveforms produced by controlled rock-fracture processes. Most equipment was designed and fabricated on campus, and details of component selection and assembly are presented. The load frame accommodates very large rock specimens, and displacement control during fracture propagation is sufficiently precise to prevent catastrophic failure during post-peak strength loading. NIST-type piezoelectric displacement transducers were built and used to ensure high signal fidelity. The developed equipment has been used successfully to study Mode I and Mode II fracture in rock. The approach used for complete system calibration, data acquisition, and reduction is explained. The methodology of waveform classification is described, and the difficulty in using commercial pattern recognition software is discussed. Results of the experiment show that new fracture surface is created by tensile crack growth in both Mode I and Mode II loading. C1 UNIV TEXAS, DEPT CIVIL ENGN ECJ 9227, AUSTIN, TX 78712 USA. RP NATL INST STAND & TECHNOL, GAITHERSBURG, MD 20899 USA. NR 22 TC 3 Z9 3 U1 0 U2 0 PU AMER SOC NONDESTRUCTIVE TEST PI COLUMBUS PA 1711 ARLINGATE LANE PO BOX 28518, COLUMBUS, OH 43228-0518 USA SN 0025-5327 J9 MATER EVAL JI Mater. Eval. PD MAR PY 1992 VL 50 IS 3 BP 354 EP + PG 1 WC Materials Science, Characterization & Testing SC Materials Science GA HJ142 UT WOS:A1992HJ14200009 ER PT J AU SIEWERT, TA FITTING, DW AUSTIN, MW AF SIEWERT, TA FITTING, DW AUSTIN, MW TI ROTATIONALLY SYMMETRICAL IMAGE QUALITY INDICATOR FOR DIGITAL X-RAY-IMAGING SYSTEMS SO MATERIALS EVALUATION LA English DT Article DE IMAGE QUALITY INDICATION; INSPECTION; NONDESTRUCTIVE EVALUATION; QUALITY CONTROL; RADIOSCOPY; TOMOGRAPHY; X-RADIOGRAPHY AB A new image quality indicator (IQI) is proposed. The design consists of a thin, high-density shell around a void or a low-density core, forming an object such as a thin-walled sphere. This design has advantages over plaque-type IQIs in that it is easier to locate when near the lower detection limit and provides image-quality information even when rotated through large angles around any axes of symmetry. These attributes allow more latitude in the scan plans of digital x-ray imaging systems and permit further automation of the image-evaluation process. A statistically based methodology is introduced for evaluating a radiographic or radioscopic image containing an IQI. This technique is useful for quantitatively determining whether the desired thickness sensitivity has been achieved. The method is operator-independent and yields the same results on repeated evaluations of the image data. Images made with IQIs of new design and also of the plaque design are amenable to evaluation with this method. RP SIEWERT, TA (reprint author), NAT INST STAND & TECHNOL,DIV MAT RELIABIL,STRUCT MAT GRP,MAIL CODE 853,325 BROADWAY,BOULDER,CO 80303, USA. NR 4 TC 2 Z9 2 U1 1 U2 1 PU AMER SOC NON-DESTRUCTIVE TEST PI COLUMBUS PA 1711 ARLINGATE LANE PO BOX 28518, COLUMBUS, OH 43228-0518 SN 0025-5327 J9 MATER EVAL JI Mater. Eval. PD MAR PY 1992 VL 50 IS 3 BP 360 EP 366 PG 7 WC Materials Science, Characterization & Testing SC Materials Science GA HJ142 UT WOS:A1992HJ14200010 ER PT J AU SIEWERT, TA AF SIEWERT, TA TI REPORT ON 1991 ACTIONS BY INTERNATIONAL-INSTITUTE-OF-WELDING SO MATERIALS EVALUATION LA English DT Article RP SIEWERT, TA (reprint author), NATL INST STAND & TECHNOL,DIV MAT RELIABIL,MAIL CODE 853 325 BROADWAY,BOULDER,CO 80303, USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU AMER SOC NON-DESTRUCTIVE TEST PI COLUMBUS PA 1711 ARLINGATE LANE PO BOX 28518, COLUMBUS, OH 43228-0518 SN 0025-5327 J9 MATER EVAL JI Mater. Eval. PD MAR PY 1992 VL 50 IS 3 BP 422 EP 423 PG 2 WC Materials Science, Characterization & Testing SC Materials Science GA HJ142 UT WOS:A1992HJ14200015 ER PT J AU FRANKLIN, JL DEMARIA, M AF FRANKLIN, JL DEMARIA, M TI THE IMPACT OF OMEGA DROPWINDSONDE OBSERVATIONS ON BAROTROPIC HURRICANE TRACK FORECASTS SO MONTHLY WEATHER REVIEW LA English DT Article ID TROPICAL CYCLONE MOTION; MODELS; PREDICTION AB A scarcity of observations in the hurricane environment is one factor believed to be limiting the improvement in hurricane track forecast accuracy. Since 1982, the Hurricane Research Division (HRD) of the NOAA Atlantic Oceanographic and Meteorological Laboratory has conducted 14 experiments to determine the wind and thermodynamic fields within about 1000 km of tropical cyclones in the Atlantic basin. During these synoptic-flow experiments, Omega dropwindsondes (ODWs) are released from the two NOAA WP-3D research aircraft over a 9-10-h period in the hurricane environment. The ODWs measure pressure, temperature, humidity, and wind as they descend from flight level (about 400 mb) to the surface. These data are then transmitted in real time to the National Hurricane Center (NHC) and the National Meteorological Center (NMC). Recently, a barotropic, nested, spectral hurricane track forecasting model, VICBAR, has been developed at HRD and tested quasi-operationally during the 1989 and 1990 hurricane seasons. Forecasts from this model have compared favorably with other models run at NHC and NMC. In this study, the VICBAR model is used to evaluate the impact of ODW data on track forecast error for the 14 HRD synoptic-flow experiments. The ODW data produced highly consistent reductions in track forecast errors in this sample of cases. Forecast improvements due to single-level-midtropospheric (aircraft) data were significantly smaller than those due to the ODWs. At the important verification times of 24-36 h (prior to landfall), when the decision to issue a hurricane warning is being made, the ODWs reduced the model mean forecast error by 12%-16%. These improvements, statistically significant at the 99% level, are comparable to the total improvement in normalized NHC official 24-h forecast error occurring over the past 20-25 years. RP FRANKLIN, JL (reprint author), NOAA,DIV HURRICAINE RES,ERL,AOML,4301 RICKENBACKER CAUSEWAY,MIAMI,FL 33149, USA. RI DeMaria, Mark/F-5583-2010 NR 22 TC 37 Z9 37 U1 1 U2 2 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 MAR PY 1992 VL 120 IS 3 BP 381 EP 391 DI 10.1175/1520-0493(1992)120<0381:TIOODO>2.0.CO;2 PG 11 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA HG832 UT WOS:A1992HG83200001 ER PT J AU JANOWIAK, JE AF JANOWIAK, JE TI TROPICAL RAINFALL - A COMPARISON OF SATELLITE-DERIVED RAINFALL ESTIMATES WITH MODEL PRECIPITATION FORECASTS, CLIMATOLOGIES, AND OBSERVATIONS SO MONTHLY WEATHER REVIEW LA English DT Article ID OUTGOING LONGWAVE RADIATION; DATA ASSIMILATION; VARIABILITY; HEMISPHERE; WINTER; OCEAN AB Quantitative estimates of rainfall, as derived from satellite observations of cloud-top temperature, have been produced for each 2.5-degrees lat-long location from 30-degrees-N to 30-degrees-S for the period 1986-89. These remotely sensed estimates are a preliminary product of the Global Precipitation Climatology Project (GPCP), which is charged with the development of a global rainfall dataset during the period 1986-95, using all available in situ data supplemented with satellite-derived estimates of precipitation. Four-year means (1986-89) of monthly satellite-derived rainfall estimates were compared to the climatological rainfall datasets compiled by Jaeger and Legates and Willmott in the tropics, to assess the performance of the satellite estimates in the context of existing state-of-the-art global precipitation datasets. It is shown that the satellite estimates and the climatologies are in reasonable agreement both in temporal and spatial variation, although some large regional differences were found. A more quantitative assessment of these estimates is also presented by comparing them with ground-based observations from a high-density radar-raingage network over Japan. Short-range forecasts of precipitation from the National Meteorological Center (NMC) Medium-Range Forecast (MRF) and the European Centre for Medium Range Weather Forecasts (ECMWF) models are also compared with the satellite estimates in the tropics. The motivation for this comparison is to assess the utility of the model precipitation forecasts as a "first guess" of the global tropical precipitation field for use in an objective analysis scheme to integrate the satellite-derived estimates and in situ data for the GPCP. The results show that the distribution and magnitude of mean tropical rainfall agree reasonably well among the estimates and model forecasts during the 9-month study period (March-November 1989). However, temporal correlations between the satellite estimates and the model precipitation predictions reveal that the models currently do not represent the time variations of rainfall in much of the tropics, particularly 30-60-day oscillations, that are apparent in the satellite estimates. RP JANOWIAK, JE (reprint author), NOAA,NWS,NATL METEOROL CTR,CTR CLIMATE ANAL,WASHINGTON,DC 20233, USA. NR 29 TC 57 Z9 59 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 MAR PY 1992 VL 120 IS 3 BP 448 EP 462 DI 10.1175/1520-0493(1992)120<0448:TRACOS>2.0.CO;2 PG 15 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA HG832 UT WOS:A1992HG83200005 ER PT J AU KOLODZIEJ, J CZUBA, P PIATKOWSKI, P PORADZISZ, A POSTAWA, Z SZYMONSKI, M FINE, J AF KOLODZIEJ, J CZUBA, P PIATKOWSKI, P PORADZISZ, A POSTAWA, Z SZYMONSKI, M FINE, J TI TEMPERATURE-DEPENDENT DYNAMIC ESD PROCESSES IN ALKALI-HALIDES SO NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH SECTION B-BEAM INTERACTIONS WITH MATERIALS AND ATOMS LA English DT Article; Proceedings Paper CT 6TH INTERNATIONAL CONF ON RADIATION EFFECTS IN INSULATORS CY JUN 24-28, 1991 CL WEIMER, GERMANY ID X-RAY PHOTOELECTRON; DIRECTIONAL EMISSION; DEFECT FORMATION; AUGER-ELECTRON; HALOGEN ATOMS; SURFACE; ENERGY; SPECTROSCOPY; SCATTERING; CRYSTALS AB The effect of the sample temperature on angular-resolved kinetic-energy distributions of alkali and halogen atoms, electronically desorbed from single crystal alkali halides, has been measured. It was found that while the emission of particles with thermal energies increased by about a factor of 40 in the temperature range 90-300-degrees-C, the nonthermal halogen atom intensity decreased by about a factor of 3. From these temperature dependent measurements the activation energies for thermally assisted defect migration processes have been estimated. The results will be compared with the data available in the literature and the predictions of a recently proposed model for electron-stimulated desorption (ESD) of alkali halides. C1 MCMASTER UNIV,INST MAT RES,HAMILTON L8S 4M1,ONTARIO,CANADA. NATL INST STAND & TECHNOL,DIV SURFACE & MICROANAL,GAITHERSBURG,MD 20899. RP KOLODZIEJ, J (reprint author), JAGIELLONIAN UNIV,INST PHYS,UL REYMONTA 4,PL-30059 KRAKOW,POLAND. NR 31 TC 13 Z9 13 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 MAR PY 1992 VL 65 IS 1-4 BP 507 EP 511 DI 10.1016/0168-583X(92)95095-9 PG 5 WC Instruments & Instrumentation; Nuclear Science & Technology; Physics, Atomic, Molecular & Chemical; Physics, Nuclear SC Instruments & Instrumentation; Nuclear Science & Technology; Physics GA HN332 UT WOS:A1992HN33200091 ER PT J AU TAKAHASHI, T TANS, PP FUNG, I AF TAKAHASHI, T TANS, PP FUNG, I TI BALANCING THE BUDGET - CARBON-DIOXIDE SOURCES AND SINKS, AND THE EFFECTS OF INDUSTRY SO OCEANUS LA English DT Article C1 NOAA,CLIMATE MONITORING & DIAGNOST LAB,BOULDER,CO 80303. NASA,GODDARD INST SPACE STUDIES,NEW YORK,NY 10025. RP TAKAHASHI, T (reprint author), COLUMBIA UNIV,LAMONT DOHERTY GEOL OBSERV,PALISADES,NY 10964, USA. NR 0 TC 6 Z9 6 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 SPR PY 1992 VL 35 IS 1 BP 18 EP 28 PG 11 WC Oceanography SC Oceanography GA HT663 UT WOS:A1992HT66300005 ER PT J AU HAMILTON, SK LEWIS, WM SIPPEL, SJ AF HAMILTON, SK LEWIS, WM SIPPEL, SJ TI ENERGY-SOURCES FOR AQUATIC ANIMALS IN THE ORINOCO RIVER FLOODPLAIN - EVIDENCE FROM STABLE ISOTOPES SO OECOLOGIA LA English DT Article DE ORINOCO RIVER; FLOODPLAIN; STABLE ISOTOPES; FOOD WEBS; ALGAE ID CARBON ISOTOPE; NITROGEN ISOTOPES; FRESH-WATER; FOOD-WEBS; AMAZON; ECOSYSTEMS; MARINE; LAKES; ALGAE; FLOW AB Stable carbon and nitrogen isotope ratios in autotrophs, aquatic invertebrates and fishes from the Orinoco River floodplain of Venezuela reveal that microalgae, including both phytoplankton and epiphytic (attached) forms, are predominant energy sources for many aquatic animals, even though aquatic vascular plants are much more abundant. Floating mats of the grass Paspalum repens and the water hyacinth Eichhornia spp. harbor particularly high densities of aquatic animals, but isotopic evidence indicates that few species are dependent on organic carbon originating from these plants. The stable isotopic evidence for the trophic importance of algae contradicts traditional interpretations of food webs in freshwater wetlands, which are generally thought to be based largely on detritus originating from vascular plants. C1 UNIV COLORADO,CTR LIMNOL,DEPT ENVIRONM POP & ORGANISM BIOL,CAMPUS BOX 334,BOULDER,CO 80309. UNIV COLORADO,NOAA,COOPERAT INST RES ENVIRONM SCI,BOULDER,CO 80309. RI Hamilton, Stephen/N-2979-2014 OI Hamilton, Stephen/0000-0002-4702-9017 NR 41 TC 186 Z9 193 U1 5 U2 33 PU SPRINGER VERLAG PI NEW YORK PA 175 FIFTH AVE, NEW YORK, NY 10010 SN 0029-8549 J9 OECOLOGIA JI Oecologia PD MAR PY 1992 VL 89 IS 3 BP 324 EP 330 PG 7 WC Ecology SC Environmental Sciences & Ecology GA HJ153 UT WOS:A1992HJ15300004 PM 28313080 ER PT J AU LAUER, RM BARNESS, LA CLARK, R DECKELBAUM, RJ FINBERG, L KWITEROVICH, PO MCBRIDE, PE SCHIEKEN, RM SCOTT, LW STRONG, JP WEIDMAN, WH ZIEGLER, EE CLEEMAN, JI ERNST, N HARLAN, WR RIFKIND, B ROSSOUW, JE QUINTADLER, L MCNEIL, CT AF LAUER, RM BARNESS, LA CLARK, R DECKELBAUM, RJ FINBERG, L KWITEROVICH, PO MCBRIDE, PE SCHIEKEN, RM SCOTT, LW STRONG, JP WEIDMAN, WH ZIEGLER, EE CLEEMAN, JI ERNST, N HARLAN, WR RIFKIND, B ROSSOUW, JE QUINTADLER, L MCNEIL, CT TI NATIONAL CHOLESTEROL EDUCATION-PROGRAM (NCEP) - HIGHLIGHTS OF THE REPORT OF THE EXPERT PANEL ON BLOOD CHOLESTEROL LEVELS IN CHILDREN AND ADOLESCENTS SO PEDIATRICS LA English DT Editorial Material C1 NHLBI,NCEP,BLDG 31,ROOM 4A05,BETHESDA,MD 20892. NR 0 TC 289 Z9 305 U1 0 U2 4 PU AMER ACAD PEDIATRICS PI ELK GROVE VILLAGE PA 141 NORTH-WEST POINT BLVD, ELK GROVE VILLAGE, IL 60007-1098 SN 0031-4005 J9 PEDIATRICS JI Pediatrics PD MAR PY 1992 VL 89 IS 3 BP 495 EP 501 PG 7 WC Pediatrics SC Pediatrics GA HG529 UT WOS:A1992HG52900026 ER PT J AU PARANTHAMAN, M FOLDEAKI, M HERMANN, AM AF PARANTHAMAN, M FOLDEAKI, M HERMANN, AM TI HOLE CONCENTRATION AND CRITICAL-TEMPERATURE IN THE TL2-X-ZBA2CA2+XCU3O10-Y SYSTEM SO PHYSICA C LA English DT Article ID CU-O SYSTEM; THALLIUM CUPRATE SUPERCONDUCTORS; BULK SUPERCONDUCTIVITY; TL2BA2CA2CU3O10; 125-K; TL2BA2CACU2O8; PHOTOEMISSION AB Single Phase bulk Tl-2223 samples were prepared in the Tl2-x-zBa2Ca2+xCu3O10-y system with x between 0 and 0.4. A small impurity phase was found at x = 0.6. All samples were found to be tetragonal. The lattice parameters a and c were nearly constant with the value of 3.858 +/- 0.002 angstrom and 35.71 +/- 0.01 angstrom, respectively. The T(c) varied between 112 and 118 K for the "as-synthesized" samples. Wet chemical analysis showed that all samples were both Tl and oxygen deficient. The T(c) was found to increase with increasing hole concentration. The origin of the holes for all these samples is due to Ca2+ substitution on the Tl3+ sites and overlap of Tl-6s band with the conduction band of the CuO2 sheets. Furthermore, the Tl-6s band overlap was found to be constant for all the samples studied. C1 NATL INST STAND & TECHNOL,BOULDER,CO 80303. RP PARANTHAMAN, M (reprint author), UNIV COLORADO,DEPT PHYS,CAMPUS BOX 390,BOULDER,CO 80309, USA. RI Paranthaman, Mariappan/N-3866-2015 OI Paranthaman, Mariappan/0000-0003-3009-8531 NR 27 TC 11 Z9 11 U1 0 U2 2 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0921-4534 J9 PHYSICA C JI Physica C PD MAR 1 PY 1992 VL 192 IS 1-2 BP 161 EP 165 DI 10.1016/0921-4534(92)90756-3 PG 5 WC Physics, Applied SC Physics GA HJ844 UT WOS:A1992HJ84400023 ER PT J AU KUCERA, JT RUBIN, LM UWAI, K PERKINS, JD GRAYBEAL, JM ORLANDO, TP VANDERSANDE, JB ROSHKO, A MORELAND, J AF KUCERA, JT RUBIN, LM UWAI, K PERKINS, JD GRAYBEAL, JM ORLANDO, TP VANDERSANDE, JB ROSHKO, A MORELAND, J TI FABRICATION OF NANOMETER SMOOTH BI2SR2CACU2O8+ DELTA FILMS BY REACTIVE COSPUTTERING FROM ELEMENTAL TARGETS WITH PURE OZONE SO PHYSICA C-SUPERCONDUCTIVITY AND ITS APPLICATIONS LA English DT Article ID SUPERCONDUCTING THIN-FILMS; GROWTH; DEPOSITION; TC AB We describe the fabrication of superconducting Bi2Sr2CaCu2O8+delta thin films having root-mean-square surface roughnesses of less than 5 nm as determined by scanning tunneling microscopy. Films are deposited in-situ by RF and DC triode magnetron sputtering from elemental metallic targets in the presence of pure ozone. As deposited, these films have transition temperatures as high as 68 K and zero-field critical current densities exceeding 10(6) A/cm2 at 4.2 K. The transition temperatures can be increased to 80 K by post-deposition annealing with only a slight increase in surface roughness. C1 MIT, DEPT MAT SCI & ENGN, CAMBRIDGE, MA 02139 USA. MIT, DEPT ELECT ENGN & COMP SCI, CAMBRIDGE, MA 02139 USA. NATL INST STAND & TECHNOL, BOULDER, CO 80303 USA. NIPPON TELEGRAPH & TEL PUBL CORP, MUSASHINO ELECT COMMUN LAB, BASIC RES LABS, MUSASHINO, TOKYO 180, JAPAN. RP KUCERA, JT (reprint author), MIT, DEPT PHYS, CAMBRIDGE, MA 02139 USA. NR 25 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 EI 1873-2143 J9 PHYSICA C JI Physica C PD MAR 1 PY 1992 VL 192 IS 1-2 BP 23 EP 30 DI 10.1016/0921-4534(92)90738-X PG 8 WC Physics, Applied SC Physics GA HJ844 UT WOS:A1992HJ84400005 ER PT J AU MOHR, PJ KIM, YK AF MOHR, PJ KIM, YK TI SELF-ENERGY OF EXCITED-STATES IN A STRONG COULOMB FIELD SO PHYSICAL REVIEW A LA English DT Article ID HYDROGEN-LIKE SYSTEMS; RADIATIVE-CORRECTIONS; ATOMS; SHIFT AB Results are given of a calculation of the self-energy radiative correction for electrons bound in a strong Coulomb field. The calculation has been done for the states with principal quantum number n = 3, 4, and 5, with angular momentum j = 1/2 and 3/2, and for nuclear charge Z in the range 10-110. RP MOHR, PJ (reprint author), NATL INST STAND & TECHNOL,GAITHERSBURG,MD 20899, USA. NR 11 TC 131 Z9 131 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 MAR 1 PY 1992 VL 45 IS 5 BP 2727 EP 2735 DI 10.1103/PhysRevA.45.2727 PG 9 WC Optics; Physics, Atomic, Molecular & Chemical SC Optics; Physics GA HH617 UT WOS:A1992HH61700015 ER PT J AU YOU, L MOSTOWSKI, J COOPER, J AF YOU, L MOSTOWSKI, J COOPER, J TI SUPPRESSION OF IONIZATION IN ONE-DIMENSIONAL AND 2-DIMENSIONAL-MODEL CALCULATIONS SO PHYSICAL REVIEW A LA English DT Article ID MULTIPHOTON IONIZATION; LINEAR-POLARIZATION; DISTORTION; HYDROGEN; INTENSE; PULSES; FIELD; ATOM AB We study numerically ionization from a model atom induced by a strong high-frequency field. Both one- and two-dimensional models are considered. We discuss the physics of ionization suppression in strong fields and point out the differences between one- and higher-dimensional models. We also discuss the applicability of classical modeling. C1 UNIV COLORADO,DEPT PHYS,BOULDER,CO 80309. NATL INST STAND & TECHNOL,BOULDER,CO 80309. RP YOU, L (reprint author), UNIV COLORADO,JOINT INST LAB ASTROPHYS,BOULDER,CO 80309, USA. NR 16 TC 18 Z9 18 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 MAR 1 PY 1992 VL 45 IS 5 BP 3203 EP 3209 DI 10.1103/PhysRevA.45.3203 PG 7 WC Optics; Physics, Atomic, Molecular & Chemical SC Optics; Physics GA HH617 UT WOS:A1992HH61700070 ER PT J AU BURNETT, K REED, VC COOPER, J KNIGHT, PL AF BURNETT, K REED, VC COOPER, J KNIGHT, PL TI CALCULATION OF THE BACKGROUND EMITTED DURING HIGH-HARMONIC GENERATION SO PHYSICAL REVIEW A LA English DT Note ID MULTIPHOTON IONIZATION; ATOM; PULSES AB We present a method for calculating the spectrum emitted by an atom in an intense laser field. This method is based on the direct use of the acceleration of the atomic electron rather than the dipole moment of the atom. We show, usign a numerical calculation in one dimension, that this method produces a more exact numerical evaluation of the spectrum. This technique is particularly important in determining the background to the high harmonics emitted by the atom. C1 NATL INST STAND & TECHNOL,BOULDER,CO 80309. UNIV LONDON IMPERIAL COLL SCI & TECHNOL,BLACKETT LAB,LONDON SW7 2BZ,ENGLAND. UNIV COLORADO,JOINT INST LAB ASTROPHYS,BOULDER,CO 80309. RP BURNETT, K (reprint author), UNIV OXFORD,CLARENDON LAB,PARKS RD,OXFORD,ENGLAND. NR 8 TC 334 Z9 356 U1 3 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 MAR 1 PY 1992 VL 45 IS 5 BP 3347 EP 3349 DI 10.1103/PhysRevA.45.3347 PG 3 WC Optics; Physics, Atomic, Molecular & Chemical SC Optics; Physics GA HH617 UT WOS:A1992HH61700089 ER PT J AU COCHRAN, JF RUDD, JM FROM, M HEINRICH, B BENNETT, W SCHWARZACHER, W EGELHOFF, WF AF COCHRAN, JF RUDD, JM FROM, M HEINRICH, B BENNETT, W SCHWARZACHER, W EGELHOFF, WF TI MAGNETIC ANISOTROPIES IN ULTRATHIN FCC FE(001) FILMS GROWN ON CU(001) SUBSTRATES SO PHYSICAL REVIEW B LA English DT Article ID BRILLOUIN LIGHT-SCATTERING; FERROMAGNETIC-RESONANCE; FE FILMS; SUPERLATTICES; SANDWICHES; CRYSTALS; CU(100) AB Ferromagnetic resonance absorption measurements at 36.3 GHz and at room temperature have been used to determine the g factor and anisotropy parameters for a series of bilayers composed of two 3-ML-thick fcc Fe (001) films separated by a variable thickness of fcc Cu(001). The resonance field and linewidth were measured versus the out-of-plane magnetic-field angle, theta(H). The magnetic properties of these ten coupled bilayer films were found to be remarkably similar from specimen to specimen, despite the fact that each member of the bilayer was only 3 ML thick. The average g factor was found to be = 2.08 +/- 0.02, and the average effective magnetization was found to be -5.5 +/- 0.5 kOe; i.e., the specimens were magnetized normal to the specimen plane in zero applied magnetic field. If the effective field along the specimen normal can be attributed to a second-order surface anisotropy energy of the form F(s) = -K(U1) sin(2)theta(M), then = 1.25 +/- 0.06 erg/cm2, assuming a value 4-pi-M(s) = 21.6 kOe for the saturation magnetization and using d = 5.4 angstrom for each film thickness. (This energy includes both sides of the film; the energy corresponding to a single Fe-Cu interface is 0.63 erg/cm2.) These specimens exhibited no measurable in-plane anisotropy. The linewidth was found to exhibit a sharp decrease for theta(H) near 20-degrees. This decrease could be explained in terms of the angular dependence of inhomogeneous line broadening due to a 1% variation in the perpendicular effective field from place to place in the sample plane. 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 35 TC 33 Z9 33 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 MAR 1 PY 1992 VL 45 IS 9 BP 4676 EP 4685 DI 10.1103/PhysRevB.45.4676 PG 10 WC Physics, Condensed Matter SC Physics GA HH418 UT WOS:A1992HH41800018 ER PT J AU SASLOW, WM ERWIN, R AF SASLOW, WM ERWIN, R TI NORMAL-MODES AND STRUCTURE FACTOR FOR A CANTED SPIN SYSTEM - THE GENERALIZED VILLAIN MODEL SO PHYSICAL REVIEW B LA English DT Article ID MAGNETIC EXCITATIONS; GLASS BEHAVIOR; COMPUTER-MODEL; MN ALLOY; WAVES; DYNAMICS; FERROMAGNETS; TRANSITION; DOMAIN; EVOLUTION AB The generalized Villain model has a rich variety of possible structures, ranging from a pure ferromagnet to a pure antiferromagnet. In between these extremes, the system is canted. Using a Heisenberg exchange Hamiltonian and linearized spin-wave theory, we have studied the normal modes and structure factors for this model. The exchange ratio J'/J and the external field have both been varied. The effect of canted spin structures on the modes and structure factors is readily seen. We believe that it is now a practical matter to study the normal modes and structure factors for more complicated systems described by this type of model. C1 TEXAS A&M UNIV SYST,CTR THEORET CHEM,COLLEGE STN,TX 77843. NATL INST STAND & TECHNOL,GAITHERSBURG,MD 20892. RP SASLOW, WM (reprint author), TEXAS A&M UNIV SYST,DEPT PHYS,COLLEGE STN,TX 77843, USA. NR 48 TC 6 Z9 6 U1 1 U2 1 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 0163-1829 J9 PHYS REV B JI Phys. Rev. B PD MAR 1 PY 1992 VL 45 IS 9 BP 4759 EP 4768 DI 10.1103/PhysRevB.45.4759 PG 10 WC Physics, Condensed Matter SC Physics GA HH418 UT WOS:A1992HH41800029 ER PT J AU MONSON, RK JAEGER, CH ADAMS, WW DRIGGERS, EM SILVER, GM FALL, R AF MONSON, RK JAEGER, CH ADAMS, WW DRIGGERS, EM SILVER, GM FALL, R TI RELATIONSHIPS AMONG ISOPRENE EMISSION RATE, PHOTOSYNTHESIS, AND ISOPRENE SYNTHASE ACTIVITY AS INFLUENCED BY TEMPERATURE SO PLANT PHYSIOLOGY LA English DT Article ID CHLOROPHYLL FLUORESCENCE; ELECTRON-TRANSPORT; GAS-EXCHANGE; HYDROCARBONS; DEPENDENCE; PLANTS; LIGHT AB Isoprene emissions from the leaves of velvet bean (Mucuna pruriens L. var utilis) plants exhibited temperature response patterns that were dependent on the plant's growth temperature. Plants grown in a warm regimen (34/28-degrees-C, day/night) exhibited a temperature optimum for emissions of 45-degrees-C, whereas those grown in a cooler regimen (26/20-degrees-C, day/night) exhibited an optimum of 40-degrees-C. Several previous studies have provided evidence of a linkage between isoprene emissions and photosynthesis, and more recent studies have demonstrated that isoprene emissions are linked to the activity of isoprene synthase in plant leaves. To further explore this linkage within the context of the temperature dependence of isoprene emissions, we determined the relative temperature dependencies of photosynthetic electron transport, CO2 assimilation, and isoprene synthase activity. When measured over a broad range of temperatures, the temperature dependence of isoprene emission rate was not closely correlated with either the electron transport rate or the CO2 assimilation rate. The temperature optima for electron transport rate and CO2 assimilation rate were 5 to 10-degrees-C lower than that for the isoprene emission rate. The dependence of isoprene emissions on photon flux density was also affected by measurement temperature in a pattern independent of those exhibited for electron transport rate and CO2 assimilation rate. Thus, despite no change in the electron transport rate or CO2 assimilation rate at 26 and 34-degrees-C, the isoprene emission rate changed markedly. The quantum yield of isoprene emissions was stimulated by a temperature increase from 26 to 34-degrees-C, whereas the quantum yield for CO2 assimilation was inhibited. In greenhouse-grown aspen leaves (Populus tremuloides Michaux.), the high temperature threshold for inhibition of isoprene emissions was closely correlated with the high temperature-induced decrease in the in vitro activity of isoprene synthase. When taken together, the results indicate that although there may be a linkage between isoprene emission rate and photosynthesis, the temperature dependence of isoprene emission is not determined solely by the rates of CO2 assimilation or electron transport. Rather, we propose that regulation is accomplished primarily through the enzyme isoprene synthase. C1 UNIV COLORADO,DEPT CHEM & BIOCHEM,BOULDER,CO 80309. UNIV COLORADO,NOAA,COOPERAT INST RES ENVIRONM SCI,BOULDER,CO 80309. RP MONSON, RK (reprint author), UNIV COLORADO,DEPT ENVIRONM POPULAT & ORGANISM BIOL,BOULDER,CO 80309, USA. NR 22 TC 160 Z9 161 U1 3 U2 29 PU AMER SOC PLANT PHYSIOLOGISTS PI ROCKVILLE PA 15501 MONONA DRIVE, ROCKVILLE, MD 20855 SN 0032-0889 J9 PLANT PHYSIOL JI Plant Physiol. PD MAR PY 1992 VL 98 IS 3 BP 1175 EP 1180 DI 10.1104/pp.98.3.1175 PG 6 WC Plant Sciences SC Plant Sciences GA HL042 UT WOS:A1992HL04200053 PM 16668743 ER PT J AU PERSILY, A AF PERSILY, A TI ENVELOPE DESIGN GUIDELINES FOR FEDERAL OFFICE BUILDINGS SO PROGRESSIVE ARCHITECTURE LA English DT Article RP PERSILY, A (reprint author), NATL INST STANDARDS & TECHNOL,BLDG & FIRE RES LAB,GAITHERSBURG,MD, USA. NR 10 TC 0 Z9 0 U1 0 U2 0 PU PENTON PUBL INC PI CLEVELAND PA 1100 SUPERIOR AVE, CLEVELAND, OH 44114 SN 0033-0752 J9 PROG ARCHIT JI Progress. Archit. PD MAR PY 1992 VL 73 IS 3 BP 39 EP 45 PG 7 WC Architecture SC Architecture GA HH851 UT WOS:A1992HH85100008 ER PT J AU KHAN, HM MCLAUGHLIN, WL AF KHAN, HM MCLAUGHLIN, WL TI GAMMA-RAY DOSIMETRY BY SPECTROFLUOROMETRY OF PHENYLACETIC ACID-SOLUTION SO RADIATION PHYSICS AND CHEMISTRY LA English DT Article AB Aqueous solutions of phenylacetic acid have been evaluated for possible use in gamma-ray dosimetry. When aerated aqueous phenylacetic acid solutions are irradiated, photofluorescent species are formed and identified as hydroxyphenylacetic acid. When excited by ultraviolet light at 280 nm, the radiation-induced product shows an emission spectrum with a maximum at 307 nm. The intensity of the emission peak at 307 nm (as well as the area under the peak from 290 to 350 nm) is a linear function of absorbed dose from 0.5 to 25 Gy. This aqueous dosimeter is about ten times more sensitive than that of the conventional ferrous sulfate solution (Fricke) dosimeter. The differences in response at dose rates in the range 0.0055-67 Gy/min are negligible. Conversely, at higher dose rates (170 Gy/min), although the response is linear with dose up to 135 Gy and with proper calibration can be used up to 350 Gy, the photofluorescence signal is somewhat greater than in the lower dose rate range. The estimated random uncertainty limits (1-sigma) of readings of absorbed dose by the dosimeter are approximately +/- 2% at a dose of 10 Gy. The fluorescence signal is very much affected by the hydrogen ion concentration of the solution and the intensity of the signal is greatest in the pH range 5 - 9.5. The radiation chemical yield of the fluorescing species is little influenced by moderate changes in the concentration of phenylacetic acid or by deaeration of the solution. The signal is stable up to at least four weeks, if the solution after irradiation is stored at low temperature (ca. 5-degrees-C). However, when stored at room temperature, and in room light, the signal is stable only up to about four days. RP KHAN, HM (reprint author), NATL INST STAND & TECHNOL,GAITHERSBURG,MD 20899, USA. RI Khan, Hasan/A-3132-2009 NR 21 TC 5 Z9 5 U1 0 U2 1 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD, ENGLAND OX5 1GB SN 0146-5724 J9 RADIAT PHYS CHEM JI Radiat. Phys. Chem. PD MAR PY 1992 VL 39 IS 3 BP 243 EP 249 PG 7 WC Chemistry, Physical; Nuclear Science & Technology; Physics, Atomic, Molecular & Chemical SC Chemistry; Nuclear Science & Technology; Physics GA HN331 UT WOS:A1992HN33100002 ER PT J AU JOHNSON, PD BROOKES, NB HULBERT, SL KLAFFKY, R CLARKE, A SINKOVIC, B SMITH, NV CELOTTA, R KELLY, MH PIERCE, DT SCHEINFEIN, MR WACLAWSKI, BJ HOWELLS, MR AF JOHNSON, PD BROOKES, NB HULBERT, SL KLAFFKY, R CLARKE, A SINKOVIC, B SMITH, NV CELOTTA, R KELLY, MH PIERCE, DT SCHEINFEIN, MR WACLAWSKI, BJ HOWELLS, MR TI SPIN-POLARIZED PHOTOEMISSION SPECTROSCOPY OF MAGNETIC-SURFACES USING UNDULATOR RADIATION SO REVIEW OF SCIENTIFIC INSTRUMENTS LA English DT Article ID ANGLE-RESOLVED PHOTOEMISSION; SYNCHROTRON RADIATION; ANALYZER; DIFFRACTION; FE(001) AB A beamline has been established at the National Synchrotron Light Source to perform angle-resolved photoemission experiments on magnetic surfaces with spin sensitivity. The system has two novel features: it uses a miniature electron-spin polarization analyzer and it also uses synchrotron radiation from an undulator rather than a bending magnet. C1 BROOKHAVEN NATL LAB,NATL SYNCHROTRON LIGHT SOURCE,UPTON,NY 11973. AT&T BELL LABS,MURRAY HILL,NJ 07974. NATL INST STAND & TECHNOL,GAITHERSBURG,MD 20899. UNIV CALIF BERKELEY,LAWRENCE BERKELEY LAB,BERKELEY,CA 94720. RP JOHNSON, PD (reprint author), BROOKHAVEN NATL LAB,DEPT PHYS,UPTON,NY 11973, USA. NR 25 TC 53 Z9 53 U1 0 U2 7 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 MAR PY 1992 VL 63 IS 3 BP 1902 EP 1908 DI 10.1063/1.1143301 PG 7 WC Instruments & Instrumentation; Physics, Applied SC Instruments & Instrumentation; Physics GA HG449 UT WOS:A1992HG44900007 ER PT J AU VENKATAKRISHNAN, P JAIN, SK SINGH, J RECELY, F LIVINGSTON, WC AF VENKATAKRISHNAN, P JAIN, SK SINGH, J RECELY, F LIVINGSTON, WC TI SPATIOTEMPORAL FLUCTUATIONS IN HE-I 10830-A LINE PARAMETERS - EVIDENCE FOR SPICULE FORMATION SO SOLAR PHYSICS LA English DT Article ID CHROMOSPHERE AB The equivalent width, line depth, line width, and Doppler shift of the He I 10830 angstrom line were extracted from two time series of spectra. Scatter plots of time-averaged line depth, line width, and Doppler shifts, as well as the root mean square temporal fluctuation of these quantities against the time-averaged equivalent width at a few hundred spatial locations were obtained. The statistical behaviour of these line parameters and their fluctuations was used to infer plausible reasons for the fluctuations. Examination of these results showed that the line parameter fluctuations could be caused by fluctuations in the coronal UV radiation (which could drive the spicules) or by the appearance of density inhomogeneities such as spicules within the line forming domain. In either case, the data can be interpreted as representing the initial phases of spicules. C1 NOAA,SPACE ENVIRONM LAB,BOULDER,CO 80303. NATL SOLAR OBSERV,TUCSON,AZ. RP VENKATAKRISHNAN, P (reprint author), INDIAN INST ASTROPHYS,BANGALORE 560034,INDIA. NR 14 TC 16 Z9 16 U1 0 U2 0 PU KLUWER ACADEMIC PUBL PI DORDRECHT PA SPUIBOULEVARD 50, PO BOX 17, 3300 AA DORDRECHT, NETHERLANDS SN 0038-0938 J9 SOL PHYS JI Sol. Phys. PD MAR PY 1992 VL 138 IS 1 BP 107 EP 121 DI 10.1007/BF00146199 PG 15 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA HH478 UT WOS:A1992HH47800009 ER PT J AU WITCZAK, SC SUEHLE, JS GAITAN, M AF WITCZAK, SC SUEHLE, JS GAITAN, M TI AN EXPERIMENTAL COMPARISON OF MEASUREMENT TECHNIQUES TO EXTRACT SI-SIO2 INTERFACE TRAP DENSITY SO SOLID-STATE ELECTRONICS LA English DT Article ID MOS CAPACITORS AB For the first time, five methods of measuring Si-SiO2 interface trap densities were compared experimentally on three otherwise identical MOSFETs which were radiation-stressed so as to induce different levels of interface trap densities. The results show that when sources of error and limitations are taken into account, these methods are capable of yielding interface trap density estimates which are in good quantitative agreement. Furthermore, the change in measured interface trap densities with radiation is independent of the method used. A comprehensive review of the methods is presented. RP WITCZAK, SC (reprint author), NATL INST STAND & TECHNOL,DIV SEMICOND ELECTR,GAITHERSBURG,MD 20899, USA. NR 22 TC 77 Z9 77 U1 0 U2 7 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD, ENGLAND OX5 1GB SN 0038-1101 J9 SOLID STATE ELECTRON JI Solid-State Electron. PD MAR PY 1992 VL 35 IS 3 BP 345 EP 355 DI 10.1016/0038-1101(92)90238-8 PG 11 WC Engineering, Electrical & Electronic; Physics, Applied; Physics, Condensed Matter SC Engineering; Physics GA HM268 UT WOS:A1992HM26800013 ER PT J AU SCHAFFT, HA SUEHLE, JS AF SCHAFFT, HA SUEHLE, JS TI THE MEASUREMENT, USE AND INTERPRETATION OF THE TEMPERATURE-COEFFICIENT OF RESISTANCE OF METALLIZATIONS SO SOLID-STATE ELECTRONICS LA English DT Article AB A review is given of the measurement and use of the temperature coefficient of resistance (TCR) of Al-based metallizations used as electrical interconnects in microelectronic circuits. The TCR has various reliability-related applications in the measurement of temperature and the characterization of a metallization for its susceptibility to electromigration failure and for the magnitude of its residual resistivity. Applications reviewed include the characterization of wafer-level test stations. RP SCHAFFT, HA (reprint author), NATL INST STAND & TECHNOL,GAITHERSBURG,MD 20899, USA. NR 11 TC 33 Z9 33 U1 1 U2 2 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD, ENGLAND OX5 1GB SN 0038-1101 J9 SOLID STATE ELECTRON JI Solid-State Electron. PD MAR PY 1992 VL 35 IS 3 BP 403 EP 410 DI 10.1016/0038-1101(92)90244-7 PG 8 WC Engineering, Electrical & Electronic; Physics, Applied; Physics, Condensed Matter SC Engineering; Physics GA HM268 UT WOS:A1992HM26800019 ER PT J AU KOPANSKI, JJ LOWNEY, JR MILES, DS NOVOTNY, DB CARVER, GP AF KOPANSKI, JJ LOWNEY, JR MILES, DS NOVOTNY, DB CARVER, GP TI HIGH SPATIAL-RESOLUTION MAPPING OF RESISTIVITY VARIATIONS IN SEMICONDUCTORS SO SOLID-STATE ELECTRONICS LA English DT Article ID RESISTANCE MEASUREMENTS; SPREADING RESISTANCE; 4-PROBE RESISTANCES; SILICON; CRYSTALS; CONTACTS; GAAS AB A new approach to the mapping of resistivity variations in semiconductors uses probe sites provided by an array of lithographically defined contacts with a density of 60,000 sites cm-2. One- or two-probe spreading resistance or four-point-probe resistance measurements can be made. Solutions of the Laplace equation and measurements on Si that had been ion-implanted to form abrupt boundaries in resistivity are used to show that the spatial resolution of the technique is determined primarily by the spacing of the measurement sites, not by the spreading of the current from the contacts. The technique has been implemented with resolution of lateral variations in resistivity of 45-mu-m in extent and +/- 5% in magnitude from the background resistivity. As an example application, a study of the resistivity variations of a Si boule with pronounced growth striations is presented. C1 NATL INST STAND & TECHNOL,DIV FACTORY AUTOMAT SYST,GAITHERSBURG,MD 20899. RP KOPANSKI, JJ (reprint author), NATL INST STAND & TECHNOL,DIV SEMICOND ELECTR,GAITHERSBURG,MD 20899, USA. NR 25 TC 5 Z9 5 U1 0 U2 1 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD, ENGLAND OX5 1GB SN 0038-1101 J9 SOLID STATE ELECTRON JI Solid-State Electron. PD MAR PY 1992 VL 35 IS 3 BP 423 EP 433 DI 10.1016/0038-1101(92)90246-9 PG 11 WC Engineering, Electrical & Electronic; Physics, Applied; Physics, Condensed Matter SC Engineering; Physics GA HM268 UT WOS:A1992HM26800021 ER PT J AU ALLEN, RA CRESSWELL, MW AF ALLEN, RA CRESSWELL, MW TI ELIMINATION OF EFFECTS DUE TO PATTERNING IMPERFECTIONS IN ELECTRICAL TEST STRUCTURES FOR SUBMICROMETER FEATURE METROLOGY SO SOLID-STATE ELECTRONICS LA English DT Article AB This paper describes the elimination of a substrate-dependent systematic error that was experienced in prior work on measuring the separation of parallel features with an electrical test structure with total errors less than 10 nm. The test structure was an enhancement of a sliding-wire voltage-dividing potentiometer which scaled the overall test structure geometry to obtain greater sensitivity. It also incorporated features to eliminate adverse effects of voltage tap- and bridge-linewidth scaling. The measurement algorithm that was developed provided the relative separations of sets of features of the 10 nm level. However, absolute measurements were offset by a quantity characteristic of the substrate for which they were extracted. The evidence suggested that these systematic errors were not caused by the primary pattern generation tool. As a result of observations, measurements and simulations, this paper attributes the substrate-characteristic systematic error to an orientation dependence of the quality of replication of certain features of the test structure. An alternative design and measurement algorithm is shown to be able to practically eliminate these errors. RP ALLEN, RA (reprint author), NATL INST STAND & TECHNOL,DIV SEMICOND ELECTR,GAITHERSBURG,MD 20899, USA. NR 6 TC 5 Z9 5 U1 0 U2 0 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD, ENGLAND OX5 1GB SN 0038-1101 J9 SOLID STATE ELECTRON JI Solid-State Electron. PD MAR PY 1992 VL 35 IS 3 BP 435 EP 442 DI 10.1016/0038-1101(92)90247-A PG 8 WC Engineering, Electrical & Electronic; Physics, Applied; Physics, Condensed Matter SC Engineering; Physics GA HM268 UT WOS:A1992HM26800022 ER PT J AU NICOL, JM AF NICOL, JM TI CHEMISORBED HYDROGEN AND HYDROGENOUS MOLECULES SO SPECTROCHIMICA ACTA PART A-MOLECULAR AND BIOMOLECULAR SPECTROSCOPY LA English DT Article ID INELASTIC NEUTRON-SCATTERING; MOLYBDENUM SULFIDE CATALYSTS; ORDER-DISORDER TRANSITIONS; VIBRATIONAL-MODES; PALLADIUM BLACK; RANEY-NICKEL; SUBSURFACE OCCUPATION; COVERED PT(111); PLATINUM BLACK; ADSORPTION AB Recent incoherent inelastic neutron scattering studies of hydrogen and hydrogenous molecules adsorbed on high-surface-area catalytic materials such as palladium and platinum black, Raney nickel and metal sulphides, are reviewed. Deuterium isotope dilution neutron spectroscopy of adsorbed hydrogen is exemplified as a probe of H-H interactions on surfaces. These studies illustrate the utility of inelastic neutron scattering for studying the vibrational spectroscopy and chemical interactions of surface species. C1 UNIV MARYLAND,COLLEGE PK,MD 20742. RP NICOL, JM (reprint author), NATL INST STAND & TECHNOL,DIV REACTOR RADIAT,GAITHERSBURG,MD 20899, USA. NR 64 TC 6 Z9 6 U1 2 U2 3 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD, ENGLAND OX5 1GB SN 0584-8539 J9 SPECTROCHIM ACTA A JI Spectroc. Acta Pt. A-Molec. Biomolec. Spectr. PD MAR PY 1992 VL 48 IS 3 BP 313 EP 327 DI 10.1016/0584-8539(92)80061-Z PG 15 WC Spectroscopy SC Spectroscopy GA HH793 UT WOS:A1992HH79300005 ER PT J AU PRIVALSKY, V CROLEY, TE AF PRIVALSKY, V CROLEY, TE TI STATISTICAL VALIDATION OF GCM-SIMULATED CLIMATES FOR THE UNITED-STATES GREAT-LAKES AND THE CIS EMBA AND URAL RIVER BASINS SO STOCHASTIC HYDROLOGY AND HYDRAULICS LA English DT Article DE HYDROLOGY; GLOBAL CIRCULATION MODELS; STATISTICS; CLIMATE CHANGE ID IMPACTS AB Many researchers use outputs from large-scale global circulation models of the atmosphere to assess hydrological and other impacts associated with climate change. However, these models cannot capture all climate variations since the physical processes are imperfectly understood and are poorly represented at smaller regional scales. This paper statistically compares model outputs from the global circulation model of the Geophysical Fluid Dynamics Laboratory to historical data for the United States' Laurentian Great Lakes and for the Emba and Ural River basins in the Commonwealth of Independent States (C.I.S.). We use maximum entropy spectral analysis to compare model and data time series, allowing us to both assess statistical predictabilities and to describe the time series in both time and frequency domains. This comparison initiates assessments of the model's representation of the real world and suggests areas of model improvement. C1 NOAA,GREAT LAKES ENVIRONM RES LAB,ANN ARBOR,MI 48105. RP PRIVALSKY, V (reprint author), ACAD SCI USSR,INST APPL ASTRON,ZHEANOVSKAYA 8,ST PETERSBURG 197042,USSR. NR 20 TC 2 Z9 2 U1 0 U2 2 PU SPRINGER VERLAG PI NEW YORK PA 175 FIFTH AVE, NEW YORK, NY 10010 SN 0931-1955 J9 STOCH HYDROL HYDRAUL JI Stoch. Hydrol. Hydraul. PD MAR PY 1992 VL 6 IS 1 BP 69 EP 80 DI 10.1007/BF01581676 PG 12 WC Engineering, Environmental; Engineering, Civil; Statistics & Probability; Water Resources SC Engineering; Mathematics; Water Resources GA HL124 UT WOS:A1992HL12400006 ER PT J AU MAHONEY, JB MCNULTY, JK AF MAHONEY, JB MCNULTY, JK TI DISEASE-ASSOCIATED BLOOD CHANGES AND NORMAL SEASONAL HEMATOLOGICAL VARIATION IN WINTER FLOUNDER IN THE HUDSON-RARITAN ESTUARY SO TRANSACTIONS OF THE AMERICAN FISHERIES SOCIETY LA English DT Note ID STRESS; TROUT; FISH AB Hematological variables of diseased and apparently healthy winter flounder Pleuronectes americanus were evaluated during fin rot epizootics in the Hudson-Raritan estuary, New York-New Jersey. Most diseased fish had significantly lower (average, 43% lower; P < 0.05) levels of hemoglobin, erythrocytes, hematocrit, and plasma protein than healthy fish; blood deficiencies were more frequent among juveniles (ages 1 and 2) than adults. The results indicate that the disease had severe consequences for this species. Normal seasonal variation in winter flounder hematology was determined by assessment of healthy fish through an annual cycle. Hemoglobin, erythrocyte, and hematocrit values were high between October and April-May and low between June and September. Plasma protein levels were high in June-December (January data were not obtained), and low in February-May. Juveniles and adults differed significantly in levels of plasma protein through the annual cycle. Temporary (1-7-month) differences in hemoglobin and erythrocyte levels between juveniles and adults also were evident. RP NATL MARINE FISHERIES SERV, NE FISHERIES SCI CTR, SANDY HOOK LAB, HIGHLANDS, NJ 07732 USA. NR 34 TC 8 Z9 9 U1 1 U2 2 PU TAYLOR & FRANCIS INC PI PHILADELPHIA PA 530 WALNUT STREET, STE 850, PHILADELPHIA, PA 19106 USA SN 0002-8487 EI 1548-8659 J9 T AM FISH SOC JI Trans. Am. Fish. Soc. PD MAR PY 1992 VL 121 IS 2 BP 261 EP 268 DI 10.1577/1548-8659(1992)121<0261:NDBCAN>2.3.CO;2 PG 8 WC Fisheries SC Fisheries GA JH778 UT WOS:A1992JH77800011 ER PT J AU COLMAN, BR DIERKING, CF AF COLMAN, BR DIERKING, CF TI THE TAKU WIND OF SOUTHEAST ALASKA - ITS IDENTIFICATION AND PREDICTION SO WEATHER AND FORECASTING LA English DT Article AB The purpose of this study is to investigate the occurrence of severe winds in southeast Alaska (locally known as Taku winds) based on recent theoretical advances in the understanding of severe downslope windstorms. We found that the Taku wind is a manifestation of an amplified mountain wave. A complicating factor in understanding the Taku is the coincident occurrence of gap flow. Analysis of a number of historical events, in addition to a unique set of wind records from a nearby ridge, shows the separate identity of these concurrent phenomena. A set of criteria is identified that must be fulfilled in order for the downslope winds to occur, which is much more restrictive than the conditions necessary for gap flow. The three necessary criteria are 1) an inversion at or just above ridgetop, somewhere between 1500 and 2000 m MSL, 2) strong cross-barrier flow near ridgetop, typically 15-20 m s-1 in geostrophic wind speed, and 3) cross-barrier flow decreasing with height to a critical level somewhere between 3000 and 5500 m MSL. The similarities to other local downslope windstorms are also discussed. RP COLMAN, BR (reprint author), NATL WEATHER SERV FORECAST OFF,7600 SAND POINT WAY NE,SEATTLE,WA 98115, USA. NR 0 TC 34 Z9 34 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 MAR PY 1992 VL 7 IS 1 BP 49 EP 64 DI 10.1175/1520-0434(1992)007<0049:TTWOSA>2.0.CO;2 PG 16 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA HK589 UT WOS:A1992HK58900003 ER PT J AU BROOKS, HE DOSWELL, CA MADDOX, RA AF BROOKS, HE DOSWELL, CA MADDOX, RA TI ON THE USE OF MESOSCALE AND CLOUD-SCALE MODELS IN OPERATIONAL FORECASTING SO WEATHER AND FORECASTING LA English DT Article AB In the near future, the technological capability will be available to use mesoscale and cloud-scale numerical models for forecasting convective weather in operational meteorology. We address some of the issues concerning effective utilization of this capability. The challenges that must be overcome are formidable. We argue that explicit prediction on the cloud scale, even if these challenges can be met, does not obviate the need for human interpretation of the forecasts. In the case that humans remain directly involved in the forecasting process, another set of issues is concerned with the constraints imposed by human involvement. As an alternative to direct explicit prediction of convective events by computers, we propose that mesoscale models be used to produce initial conditions for cloud-scale models. Cloud-scale models then can be run in a Monte Carlo-like mode, in order to provide an estimate of the probable types of convective weather for a forecast period. In our proposal, human forecasters fill the critical role as an interface between various stages of the forecasting and warning process. In particular, they are essential in providing input to the numerical models from the observational data and in interpreting the model output. This interpretative step is important both in helping the forecaster anticipate and interpret new observations and in providing information to the public. RP BROOKS, HE (reprint author), NOAA,NATL SEVERE STORMS LAB,1313 HALLEY CIRCLE,NORMAN,OK 73069, USA. RI Doswell III, Charles/E-7662-2010 NR 0 TC 47 Z9 49 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 MAR PY 1992 VL 7 IS 1 BP 120 EP 132 DI 10.1175/1520-0434(1992)007<0120:OTUOMA>2.0.CO;2 PG 13 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA HK589 UT WOS:A1992HK58900007 ER PT J AU BRANICK, ML DOSWELL, CA AF BRANICK, ML DOSWELL, CA TI AN OBSERVATION OF THE RELATIONSHIP BETWEEN SUPERCELL STRUCTURE AND LIGHTNING GROUND-STRIKE POLARITY SO WEATHER AND FORECASTING LA English DT Note AB Cloud-to-ground lightning data are presented from tornadic thunderstorms in Oklahoma, Kansas, and Nebraska on 13 March 1990. The tornadic storms from northern Oklahoma northward into Kansas and Nebraska produced an unusually high percentage of positive cloud-to-ground (+CG) flashes, whereas those in central and southern Oklahoma produced mostly negative flashes. Visual evidence indicates a distinct difference in structure between the northern storms, which produced high +CG rates, and the southern storms, which did not. The storms with high +CG rates possessed characteristics of storms in the low-precipitation (LP) portion of the supercell spectrum. In contrast, visual and radar characteristics indicate that the southern storms with lower +CG frequencies were in the high-precipitation (HP) portion of the supercell spectrum. These findings are consistent with another recent study linking high +CG rates with LP storms. Based on these observations, potential benefits of realtime lightning-strike data to forecast and warning operations are considered. RP BRANICK, ML (reprint author), NOAA,NATL WEATHER SERV,FORECAST OFF,1200 WESTHEIMER DR,NORMAN,OK 73069, USA. RI Doswell III, Charles/E-7662-2010 NR 0 TC 64 Z9 66 U1 0 U2 5 PU AMER METEOROLOGICAL SOC PI BOSTON PA 45 BEACON ST, BOSTON, MA 02108-3693 SN 0882-8156 J9 WEATHER FORECAST JI Weather Forecast. PD MAR PY 1992 VL 7 IS 1 BP 143 EP 149 DI 10.1175/1520-0434(1992)007<0143:AOOTRB>2.0.CO;2 PG 7 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA HK589 UT WOS:A1992HK58900009 ER PT J AU LEDBETTER, H DATTA, S AF LEDBETTER, H DATTA, S TI CAST-IRON ELASTIC-CONSTANTS - EFFECT OF GRAPHITE ASPECT RATIO SO ZEITSCHRIFT FUR METALLKUNDE LA English DT Article ID COMPOSITE AB Using a scattered-plane-wave ensemble-average model developed for composite materials, we calculated the effective elastic constants of cast iron. We focused on the effect of graphite-particle aspect ratio on the Young modulus. Between model and observation, we found good agreement. Oblatespheroidal graphite flakes lower the elastic stiffness much more than do spheres. To obtain good model-measurement agreement, one must use graphite's lower third-order-bound (Kroner-bound) elastic constants. Besides the Young modulus, we give calculated results for all the other usual quasi-isotropic elastic constants: shear modulus, Poisson ratio, and bulk modulus. C1 UNIV COLORADO,NOAA,COOPERAT INST RES ENVIRONM SCI,BOULDER,CO 80309. UNIV COLORADO,DEPT MECH ENGN,BOULDER,CO 80309. RP LEDBETTER, H (reprint author), NATL INST STAND & TECHNOL,MAT SCI & ENGN LAB,BOULDER,CO 80303, USA. NR 20 TC 13 Z9 14 U1 0 U2 0 PU CARL HANSER VERLAG PI MUNICH PA KOLBERGERSTRASSE 22, POSTFACH 860420, W-8163 MUNICH, GERMANY SN 0044-3093 J9 Z METALLKD JI Z. Metallk. PD MAR PY 1992 VL 83 IS 3 BP 195 EP 198 PG 4 WC Metallurgy & Metallurgical Engineering SC Metallurgy & Metallurgical Engineering GA HN816 UT WOS:A1992HN81600009 ER PT J AU CRAFT, NE WISE, SA SOARES, JH AF CRAFT, NE WISE, SA SOARES, JH TI INFLUENCE OF STORAGE-TEMPERATURE, LYOPHILIZATION, AND GAMMA-IRRADIATION ON DIETARY CAROTENOIDS SO FASEB JOURNAL LA English DT Meeting Abstract C1 NIST,CHEM SCI & TECHNOL LAB,GAITHERSBURG,MD 20899. UNIV MARYLAND,NUTR SCI PROGRAM,COLLEGE PK,MD 20874. NR 0 TC 0 Z9 0 U1 0 U2 0 PU FEDERATION AMER SOC EXP BIOL PI BETHESDA PA 9650 ROCKVILLE PIKE, BETHESDA, MD 20814-3998 USA SN 0892-6638 J9 FASEB J JI Faseb J. PD FEB 28 PY 1992 VL 6 IS 5 BP A1657 EP A1657 PN 2 PG 1 WC Biochemistry & Molecular Biology; Biology; Cell Biology SC Biochemistry & Molecular Biology; Life Sciences & Biomedicine - Other Topics; Cell Biology GA HH271 UT WOS:A1992HH27100337 ER PT J AU DAWSON, MA RENFRO, JL AF DAWSON, MA RENFRO, JL TI EFFECTS OF CHLOROPHENOXY HERBICIDES ON TRANSEPITHELIAL TRANSPORT OF ORGANIC-ANIONS BY PRIMARY CULTURES OF WINTER FLOUNDER RENAL PROXIMAL TUBULES SO FASEB JOURNAL LA English DT Meeting Abstract C1 UNIV CONNECTICUT,DEPT PHYSIOL & NEUROBIOL,STORRS,CT 06269. NOAA,NATL MARINE FISHERIES SERV,MILFORD,CT 06460. NR 0 TC 0 Z9 0 U1 0 U2 0 PU FEDERATION AMER SOC EXP BIOL PI BETHESDA PA 9650 ROCKVILLE PIKE, BETHESDA, MD 20814-3998 USA SN 0892-6638 J9 FASEB J JI Faseb J. PD FEB 28 PY 1992 VL 6 IS 5 BP A1809 EP A1809 PN 2 PG 1 WC Biochemistry & Molecular Biology; Biology; Cell Biology SC Biochemistry & Molecular Biology; Life Sciences & Biomedicine - Other Topics; Cell Biology GA HH271 UT WOS:A1992HH27101211 ER PT J AU GAFFEN, DJ BARNETT, TP AF GAFFEN, DJ BARNETT, TP TI A COMPARISON OF OBSERVATIONS AND MODEL SIMULATIONS OF TROPOSPHERIC WATER-VAPOR SO JOURNAL OF GEOPHYSICAL RESEARCH-ATMOSPHERES LA English DT Article ID SEA-SURFACE TEMPERATURE AB Observations of tropospheric specific humidity from radiosondes for the period 1973-1986 are compared with simulated specific humidity fields from a University of Hamburg version of the European Center for Medium-Range Weather Forecasting General Circulation Model (GCM), forced by observed sea surface temperatures. The mean January and July fields are shown to be in good agreement, despite the much poorer resolution of the radiosonde network used. Temporal and spatial variations of specific humidity are examined through empirical orthogonal function analysis of tropical data. The first mode of variability of the data was similar to that of the model simulations and shows evidence of a coherent, decadal-scale variation in tropospheric moisture content. The overall agreement between the model and the data, while not complete, suggests that long-term mean patterns and decadal variations in moisture, as delineated by a sparse data network, are reasonably well simulated. More comprehensive comparisons of tropospheric moisture data with GCM simulations from different models are suggested. C1 UNIV CALIF SAN DIEGO, SCRIPPS INST OCEANOG, DIV CLIMATE RES, LA JOLLA, CA 92093 USA. RP GAFFEN, DJ (reprint author), NOAA, AIR RESOURCES LAB, R-E AR, 1325 E W HIGHWAY, SILVER SPRING, MD 20910 USA. NR 16 TC 10 Z9 10 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 FEB 28 PY 1992 VL 97 IS D3 BP 2775 EP 2780 PG 6 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA HG561 UT WOS:A1992HG56100010 ER PT J AU RAMASWAMY, V SCHWARZKOPF, MD SHINE, KP AF RAMASWAMY, V SCHWARZKOPF, MD SHINE, KP TI RADIATIVE FORCING OF CLIMATE FROM HALOCARBON-INDUCED GLOBAL STRATOSPHERIC OZONE LOSS SO NATURE LA English DT Article ID GENERAL-CIRCULATION MODEL; DYNAMICAL RESPONSE; ANTARCTIC OZONE; CARBON-DIOXIDE; DEPLETION; BALANCE AB OBSERVATIONS from satellite and ground-based instruments 1-3 indicate that between 1979 and 1990 there have been statistically significant losses of ozone in the lower stratosphere of the middle to high latitudes in both hemispheres. Here we determine the radiative forcing of the surface-troposphere system 4-6 due to the observed decadal ozone losses, and compare it with that due to the increased concentrations of the other main radiatively active gases (CO2, CH4, N2O and chlorofluorocarbons) over the same time period. Our results indicate that a significant negative radiative forcing results from ozone losses in middle to high latitudes, in contrast to the positive forcing at all latitudes caused by the CFCs and other gases. As the anthropogenic emissions of CFCs and other halocarbons are thought to be largely responsible for the observed ozone depletions 1, our results suggest that the net decadal contribution of CFCs to the greenhouse climate forcing is substantially less than previously estimated. C1 NOAA,GEOPHYS FLUID DYNAM LAB,PRINCETON,NJ 08542. UNIV READING,DEPT METEOROL,READING RG6 2AU,ENGLAND. RP RAMASWAMY, V (reprint author), PRINCETON UNIV,ATMOSPHER & OCEAN SCI PROGRAM,PRINCETON,NJ 08542, USA. RI Shine, Keith/D-9093-2012 OI Shine, Keith/0000-0003-2672-9978 NR 27 TC 116 Z9 117 U1 2 U2 13 PU MACMILLAN MAGAZINES LTD PI LONDON PA PORTERS SOUTH, 4 CRINAN ST, LONDON, ENGLAND N1 9XW SN 0028-0836 J9 NATURE JI Nature PD FEB 27 PY 1992 VL 355 IS 6363 BP 810 EP 812 DI 10.1038/355810a0 PG 3 WC Multidisciplinary Sciences SC Science & Technology - Other Topics GA HF636 UT WOS:A1992HF63600050 ER PT J AU WEST, TG ARTHUR, PG BRILL, RW SCHULTE, PM HOCHACHKA, PW AF WEST, TG ARTHUR, PG BRILL, RW SCHULTE, PM HOCHACHKA, PW TI RAPID AND SYNCHRONOUS CHANGES IN LACTATE AND PCR IN VERTEBRATE WHITE MUSCLE DURING RECOVERY FROM EXERCISE SO FASEB JOURNAL LA English DT Meeting Abstract C1 UNIV BRITISH COLUMBIA,VANCOUVER V6T 1W5,BC,CANADA. NATL MARINE FISHERIES SERV,SW FISHERIES CTR,HONOLULU,HI. NR 0 TC 0 Z9 0 U1 0 U2 1 PU FEDERATION AMER SOC EXP BIOL PI BETHESDA PA 9650 ROCKVILLE PIKE, BETHESDA, MD 20814-3998 SN 0892-6638 J9 FASEB J JI Faseb J. PD FEB 26 PY 1992 VL 6 IS 4 BP A1197 EP A1197 PN 1 PG 1 WC Biochemistry & Molecular Biology; Biology; Cell Biology SC Biochemistry & Molecular Biology; Life Sciences & Biomedicine - Other Topics; Cell Biology GA HG719 UT WOS:A1992HG71901505 ER PT J AU DESHLER, T HOFMANN, DJ AF DESHLER, T HOFMANN, DJ TI MEASUREMENTS OF UNUSUAL AEROSOL LAYERS IN THE UPPER TROPOSPHERE OVER LARAMIE, WYOMING IN THE SPRING OF 1991 - EVIDENCE FOR LONG-RANGE TRANSPORT FROM THE OIL FIRES IN KUWAIT SO GEOPHYSICAL RESEARCH LETTERS LA English DT Article AB Unusual aerosol layers in the upper troposphere were observed on seven consecutive balloon soundings between 7 March and 17 June 1991, at Laramie, Wyoming (41-degrees-N, 106-degrees-W). The layers varied in thickness from 1 to 4 km and the top of the layer was always at or near the tropopause. Aerosol concentrations for the size range 0.15 to 1.0-mu-m radius were increased by factors of 5 to 10 over what is usual at those altitudes. Compared with the previous four year record, these seven soundings represent the highest sustained concentrations observed between 8 and 11 km, with the sounding on March 25 representing the highest concentrations observed. Although the origin of these unusual aerosol layers is not definite, trajectory calculations and impactor measurements indicate that, in the absence of an alternate explanation, the oil fires in Kuwait are the likely source. C1 NOAA,CLIMATE MONITORING & DIAGNOST LAB,BOULDER,CO 80303. RP DESHLER, T (reprint author), UNIV WYOMING,DEPT PHYS & ASTRON,LARAMIE,WY 82071, USA. NR 9 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 FEB 21 PY 1992 VL 19 IS 4 BP 385 EP 388 DI 10.1029/92GL00284 PG 4 WC Geosciences, Multidisciplinary SC Geology GA HF221 UT WOS:A1992HF22100014 ER PT J AU SHERIDAN, PJ SCHNELL, RC HOFMANN, DJ HARRIS, JM DESHLER, T AF SHERIDAN, PJ SCHNELL, RC HOFMANN, DJ HARRIS, JM DESHLER, T TI ELECTRON-MICROSCOPE STUDIES OF AEROSOL LAYERS WITH LIKELY KUWAITI ORIGINS OVER LARAMIE, WYOMING DURING SPRING 1991 SO GEOPHYSICAL RESEARCH LETTERS LA English DT Article AB Upper tropospheric aerosols observed in spring 1991 over Laramie, Wyoming, were sampled using balloon-borne cascade impactors. Three impactor samples were collected; two were in upper tropospheric aerosol layers and one was collected at the same altitude in cleaner, "background" upper tropospheric air. Optical particle counters measured concentrations of particles with radii greater-than-or-equal-to 0.15-mu-m in the layers which were increased 5-10 times over what is normally observed at these altitudes. Electron microscope analyses showed acidic and neutralized sulfate particles to be the dominant aerosol constituents in these layers, although carbonaceous soot aggregates and crustal dust particles were also found. The morphology and elemental composition of these particles closely resembled particles collected in the large mixed smoke plume of the Kuwaiti oil fires. Meteorological analyses showed favorable transport conditions from the Middle East to the continental U.S. when layers were present over Wyoming, and less than ideal conditions when the layers were absent. Based on these microanalytical results and the corroborating meteorological and air trajectory analyses, the most likely source of these aerosol layers is the oil fires in Kuwait. C1 NOAA,ENVIRONM RES LAB,CLIMATE MONITORING & DIAGNOST LAB,BOULDER,CO 80303. UNIV WYOMING,DEPT PHYS & ASTRON,LARAMIE,WY 82071. RP SHERIDAN, PJ (reprint author), UNIV COLORADO,NOAA,COOPERAT INST RES ENVIRONM SCI,BOULDER,CO 80309, USA. NR 8 TC 22 Z9 22 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 FEB 21 PY 1992 VL 19 IS 4 BP 389 EP 392 DI 10.1029/92GL00049 PG 4 WC Geosciences, Multidisciplinary SC Geology GA HF221 UT WOS:A1992HF22100015 ER PT J AU WATERSTRAT, RM AF WATERSTRAT, RM TI NEW TERNARY LAVES PHASES SO JOURNAL OF ALLOYS AND COMPOUNDS LA English DT Letter RP WATERSTRAT, RM (reprint author), NATL INST STAND & TECHNOL,DIV POLYMERS,PAFFENBARGER RES CTR,AMER DENT ASSOC HLTH FDN,GAITHERSBURG,MD 20899, USA. NR 0 TC 5 Z9 5 U1 0 U2 0 PU ELSEVIER SCIENCE SA LAUSANNE PI LAUSANNE 1 PA PO BOX 564, 1001 LAUSANNE 1, SWITZERLAND SN 0925-8388 J9 J ALLOY COMPD JI J. Alloy. Compd. PD FEB 21 PY 1992 VL 179 BP L33 EP L33 DI 10.1016/0925-8388(92)90199-J PG 1 WC Chemistry, Physical; Materials Science, Multidisciplinary; Metallurgy & Metallurgical Engineering SC Chemistry; Materials Science; Metallurgy & Metallurgical Engineering GA HG643 UT WOS:A1992HG64300007 ER PT J AU MOUNT, GH AF MOUNT, GH TI THE MEASUREMENT OF TROPOSPHERIC OH BY LONG PATH ABSORPTION .1. INSTRUMENTATION SO JOURNAL OF GEOPHYSICAL RESEARCH-ATMOSPHERES LA English DT Article ID LASER-INDUCED FLUORESCENCE; O3-H2O INTERFERENCE PROBLEM; RESONANCE FLUORESCENCE; OPTICAL-ABSORPTION; INSITU DETECTION; NATURAL LEVELS; AMBIENT AIR; STRATOSPHERE; ATMOSPHERE; CHEMISTRY AB The determination of the concentration of OH in the Earth's troposphere is of fundamental importance to an understanding of the chemistry of the lower atmosphere. Many experiments to measure OH concentration have been performed in recent years; very few of these experiments have produced significant results. In particular, because of the extremely low amount of OH in the clean troposphere (several tenths parts per trillion by volume at summertime local noon), none of the experiments performed have attained the sensitivity limit necessary to test the photochemical theories of OH and its temporal behavior. Described here is an experiment utilizing a laser source and very high resolution ultraviolet absorption spectroscopy to measure the concentration of OH in a clean environment at a measured sensitivity limit of approximately 5 x 10(5) cm-3 (0.01 pptv) with an integration time of several minutes. This limit is substantially below predicted noontime OH concentrations and should be low enough to provide a rigorous test of photochemical theories of hydroxyl formation. This paper describes the instrumentation developed to make the measurements. RP MOUNT, GH (reprint author), NOAA, ENVIRONM RES LABS, AERON LAB, BOULDER, CO 80303 USA. NR 49 TC 63 Z9 64 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 FEB 20 PY 1992 VL 97 IS D2 BP 2427 EP 2444 PG 18 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA HE957 UT WOS:A1992HE95700001 ER PT J AU RAY, JD VANVALIN, CC BOATMAN, JF AF RAY, JD VANVALIN, CC BOATMAN, JF TI THE VERTICAL-DISTRIBUTION OF ATMOSPHERIC H2O2 - A CASE-STUDY SO JOURNAL OF GEOPHYSICAL RESEARCH-ATMOSPHERES LA English DT Article ID NORTHEASTERN UNITED-STATES; HYDROGEN-PEROXIDE; ACID GENERATION; TROPOSPHERE; CHEMISTRY; SUMMER AB Vertical profiles of H2O2 mixing ratios were obtained for each season from a site in central Arkansas during 1988. Aircraft-based measurements indicated that H2O2 mixing ratios followed an annual cycle, peaking during the summer at > 6 parts per billion by volume (ppbv). The minimum occurred in winter when mixing ratios for H2O2 averaged about 0.2 ppbv. The H2O2 mixing ratio generally peaked at an altitude of about 800 mbar (2 km), although there may have been some seasonal dependence. The annual cycle followed variations in solar intensity, water mixing ratio, and temperature. Within a season, strong variations could be related to meteorological events. A daily cycle was inferred in which the H2O2 mixing ratio varied by a factor of 2 to 3; the peak observed values were at night. H2O2 mixing ratios at altitudes higher than 0.7 km were generally greater than local SO2 values above 0.7 km during all but the winter season. C1 UNIV COLORADO, NOAA, COOPERAT INST RES ENVIRONM SCI, BOULDER, CO 80309 USA. NOAA, AIR RESOURCES LAB, AEROSOL RES STN, BOULDER, CO 80303 USA. NR 24 TC 16 Z9 17 U1 1 U2 3 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 FEB 20 PY 1992 VL 97 IS D2 BP 2507 EP 2517 PG 11 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA HE957 UT WOS:A1992HE95700006 ER PT J AU ZHANG, ZY HUIE, RE KURYLO, MJ AF ZHANG, ZY HUIE, RE KURYLO, MJ TI RATE CONSTANTS FOR THE REACTIONS OF OH WITH CH3CFCL2 (HCFC-141B), CH3CF2CL (HCFC-142B), AND CH2FCF3 (HFC-134A) SO JOURNAL OF PHYSICAL CHEMISTRY LA English DT Letter ID HYDROXYL RADICALS AB The rate constants for the reaction of OH with CH3CFCl2(HCFC-141b) over the temperature range 250-297 K were remeasured with improved detection sensitivity as a function of flash energy and concentration of OH radical precursor (H2O). The rate constants were reduced at the lower OH concentrations employed, suggesting complications due to secondary reactions. The new values disagree with the low-temperature values reported earlier but agree with the values extrapolated from the higher temperature results (T > 298 K). In contrast, rate constants for CH3CF2Cl(HCFC-142b) and CH2FCF3(HFC-134a), remeasured at the lower flash energy at 270 K, were found to agree with those reported earlier at higher flash energy. C1 NATL INST STAND & TECHNOL,DIV CHEM KINET & THERMODYNAM,GAITHERSBURG,MD 20899. RI Huie, Robert/A-5645-2010; Kurylo, Michael/H-2201-2012 NR 7 TC 24 Z9 24 U1 1 U2 1 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 SN 0022-3654 J9 J PHYS CHEM-US JI J. Phys. Chem. PD FEB 20 PY 1992 VL 96 IS 4 BP 1533 EP 1535 DI 10.1021/j100183a008 PG 3 WC Chemistry, Physical SC Chemistry GA HF283 UT WOS:A1992HF28300008 ER PT J AU CRAIG, NC BRANDON, DW STONE, SC LAFFERTY, WJ AF CRAIG, NC BRANDON, DW STONE, SC LAFFERTY, WJ TI PARTIAL STRUCTURE FOR TRANS-1,2-DIFLUOROETHYLENE FROM HIGH-RESOLUTION INFRARED-SPECTROSCOPY SO JOURNAL OF PHYSICAL CHEMISTRY LA English DT Article ID CIS; 1,2-DIFLUOROETHYLENES; MOLECULES AB Three bands in the high-resolution infrared spectrum of trans-1,2-difluoroethylene have been examined. An A-type band at 1274 cm-1 due to in-plane CH bending, nu(10)(b(u)), and a C-type band at 874 cm-1 due to out-of-plane CH bending, nu(6)(a(u)), have been fully analyzed. The B-type component of a hybrid A/B-band at 1657 cm-1 due to the nu(6)(a(u)) + nu(8)(b(g)) combination tone has been partly analyzed. Ground-state rotational constants of A = 1.893 409 7 (24) cm-1, B = 0.134 537 56 (64) cm-1, and C = 0.125 543 44 (59) cm-1 in a Watson-type Hamiltonian have been fit to 1670 ground-state combination differences derived from the three bands. When CH and CC geometric parameters are held at the cis isomer values, a CCF bond angle of 119.6-degrees and a CF bond length of 1.345 angstrom are fit to the principal moments of inertia of the trans isomer. The CCF bond angle is 2.5-degrees smaller and the CF bond length is 0.010 angstrom longer in the trans isomer. A complete structure for the trans isomer awaits analysis of the spectra of the d2 and d1 isotopomers. C1 NATL INST STAND & TECHNOL,DIV MOLEC PHYS,GAITHERSBURG,MD 20899. RP CRAIG, NC (reprint author), OBERLIN COLL,DEPT CHEM,OBERLIN,OH 44074, USA. NR 24 TC 14 Z9 14 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 FEB 20 PY 1992 VL 96 IS 4 BP 1598 EP 1605 DI 10.1021/j100183a022 PG 8 WC Chemistry, Physical SC Chemistry GA HF283 UT WOS:A1992HF28300022 ER PT J AU ROWLEY, RL ELY, JF AF ROWLEY, RL ELY, JF TI NONEQUILIBRIUM MOLECULAR-DYNAMICS SIMULATIONS OF STRUCTURED MOLECULES .2. ISOMERIC EFFECTS ON THE VISCOSITY OF MODELS FOR NORMAL-HEXANE, CYCLOHEXANE AND BENZENE SO MOLECULAR PHYSICS LA English DT Article ID TRANSPORT-PROPERTIES; LIQUID BENZENE; COMPUTER-SIMULATION; SOLID BENZENE; N-ALKANES AB The failure of extended corresponding-states techniques to predict the viscosity of low molecular weight branched and cyclic hydrocarbons suggests that molecular structure greatly affects the viscosities of these species. To investigate the inter-relationship of structure and viscosity, non-equilibrium molecular dynamics simulation's of Lennard-Jones site-site models representing selected simple molecules were performed. The simulation conditions nearly span the liquid density range over which experimental data are currently available. In this study, models representing n-hexane, cyclohexane and benzene were constructed using six equivalent sites, each characterized by the same Lennard-Jones parameters used in a previous study of n-butane and isobutane viscosities. The focus was, therefore, entirely on structural effects. Simulated viscosities agreed well with experimental values of n-hexane and cyclohexane indicating that structural differences primarily account for the differences in viscosity between these two fluids. Simulated benzene viscosities were substantially higher than experimental values, indicating important non-structural effects. The relationship between fluid structure and the applied shear field are discussed. C1 NATL INST STAND & TECHNOL, BOULDER, CO 80303 USA. RP BRIGHAM YOUNG UNIV, PROVO, UT 84602 USA. NR 31 TC 22 Z9 23 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 FEB 20 PY 1992 VL 75 IS 3 BP 713 EP 730 DI 10.1080/00268979200100521 PG 18 WC Chemistry, Physical; Physics, Atomic, Molecular & Chemical SC Chemistry; Physics GA HG118 UT WOS:A1992HG11800015 ER PT J AU VANDEGRIFT, CT YOSHIHIRO, K CAGE, ME YU, DY SEGAWA, K KINOSHITA, J ENDO, T AF VANDEGRIFT, CT YOSHIHIRO, K CAGE, ME YU, DY SEGAWA, K KINOSHITA, J ENDO, T TI ANOMALOUSLY OFFSET QUANTIZED HALL PLATEAUS IN HIGH-MOBILITY SI-MOSFETS SO SURFACE SCIENCE LA English DT Article; Proceedings Paper CT 9TH INTERNATIONAL CONF ON THE ELECTRONIC PROPERTIES OF TWO-DIMENSIONAL SYSTEMS ( EP2DS-9 ) / 5TH INTERNATIONAL CONF ON MODULATED SEMICONDUCTOR STRUCTURES ( MSS-5 ) CY JUL 08-12, 1991 CL NARA, JAPAN SP YAMADA SCI FDN ID RESISTANCE; PRECISION AB Measurements made using two independent, high-precision systems on different samples of high mobility Si-MOSFETs have revealed unexpected irregularities in their i = 4 quantized Hall plateaus in spite of exceedingly low diagonal resistivities, 0.002 ppm of the plateau value. Relatively flat, metastable plateaus were observed which were offset by up to 0.4 ppm above the corresponding GaAs/AlGaAs value under the measurements at 14-14.5 T, 0.34-0.5 K with about 10-mu-A sample current. Possible connection of these phenomena with the offset plateaus observed by Kawaji et al. is discussed. At present no satisfactory explanation has been provided for these phenomena. C1 ELECTROTECH LAB,TSUKUBA,IBARAKI 305,JAPAN. RP VANDEGRIFT, CT (reprint author), NATL INST STAND & TECHNOL,GAITHERSBURG,MD 20899, 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 0039-6028 J9 SURF SCI JI Surf. Sci. PD FEB 19 PY 1992 VL 263 IS 1-3 BP 116 EP 119 DI 10.1016/0039-6028(92)90318-Z PG 4 WC Chemistry, Physical; Physics, Condensed Matter SC Chemistry; Physics GA HF186 UT WOS:A1992HF18600022 ER PT J AU BROWN, GN BIRKS, JW KOVAL, CA AF BROWN, GN BIRKS, JW KOVAL, CA TI DEVELOPMENT AND CHARACTERIZATION OF A TITANIUM DIOXIDE-BASED SEMICONDUCTOR PHOTOELECTROCHEMICAL DETECTOR SO ANALYTICAL CHEMISTRY LA English DT Article ID PERFORMANCE LIQUID-CHROMATOGRAPHY; SOLAR-ENERGY CONVERSION; NUCLEAR MAGNETIC-RESONANCE; WHOLE COLUMN DETECTION; ELECTROCHEMICAL DETECTION; CROSS-POLARIZATION; ELECTRODES; WATER; SYSTEMS; FILMS AB The development and characterization of a flow-through semiconductor-based titanium dioxide photoelectrochemical detector for flow injection analysis and liquid chromatography is described. The detector is nonselective, responding to a variety of organic analytes including amines, aromatic alcohols, hydroquinones, aldehydes, and furans with redox potentials less positive than the valence band edge of the titanium dioxide semiconductor. An investigation of the illuminated photoelectrochemistry and dark semiconductor electrochemical properties of the detector was carried out as a function of solvent system, electrochemical potential, and TiO2 production variables. Illumination intensity, titanium oxidation temperature, and electrode potential controlled the magnitude of the photoelectrochemical currents. Duration of thermal oxidation and the amount of hydrogen doping determined the ratio of the light to dark current for the analyte. Linearity over 2 orders of magnitude and detection limits in acetonitrile of 40 and 140 pmol, for p-aminoacetanillide and diethylamine, respectively, were demonstrated. Illumination of the semiconducting TiO2 wire electrode along a cylindrical electrochemical cell indicated the possible application of this spatially-resolved detection technique to whole column detection chromatography. C1 UNIV COLORADO, DEPT CHEM & BIOCHEM, CAMPUS BOX 216, BOULDER, CO 80309 USA. UNIV COLORADO, NOAA, COOPERAT INST RES ENVIRONM SCI, BOULDER, CO 80309 USA. RI Birks, John/H-7451-2013 OI Birks, John/0000-0003-1691-1354 NR 51 TC 25 Z9 26 U1 0 U2 10 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 0003-2700 EI 1520-6882 J9 ANAL CHEM JI Anal. Chem. PD FEB 15 PY 1992 VL 64 IS 4 BP 427 EP 434 DI 10.1021/ac00028a018 PG 8 WC Chemistry, Analytical SC Chemistry GA HE081 UT WOS:A1992HE08100018 ER PT J AU HUBBARD, JB NGUYEN, T BENTZ, D AF HUBBARD, JB NGUYEN, T BENTZ, D TI A MODEL OF DEFECT-MEDIATED TRANSPORT THROUGH AMORPHOUS MEMBRANES SO JOURNAL OF CHEMICAL PHYSICS LA English DT Article ID RELAXATION AB We introduce a class of membrane diffusion models which consists of an impermeable slab punctured by transmembrane pores which are constructed by continuous random-walk algorithms. These formally infinite tortuosity models closely resemble low tortuosity models in their steady-state flux and total transient uptake. The sharpest contrast between random and homogeneous membranes is in the stretched exponential (subdiffusive) decay [exp( -t(alpha)), alpha = 1/2] of the transient diffusive flux for the random-pore models vs simple exponential decay [exp( -t)] for homogeneous membranes. RP HUBBARD, JB (reprint author), NATL INST STAND & TECHNOL,GAITHERSBURG,MD 20899, USA. NR 31 TC 5 Z9 6 U1 0 U2 1 PU AMER INST PHYSICS PI WOODBURY PA CIRCULATION FULFILLMENT DIV, 500 SUNNYSIDE BLVD, WOODBURY, NY 11797-2999 SN 0021-9606 J9 J CHEM PHYS JI J. Chem. Phys. PD FEB 15 PY 1992 VL 96 IS 4 BP 3177 EP 3182 DI 10.1063/1.461961 PG 6 WC Chemistry, Physical; Physics, Atomic, Molecular & Chemical SC Chemistry; Physics GA HE743 UT WOS:A1992HE74300078 ER PT J AU BAND, YB JULIENNE, PS AF BAND, YB JULIENNE, PS TI COMPLETE ALIGNMENT AND ORIENTATION OF ATOMS AND MOLECULES BY STIMULATED RAMAN-SCATTERING WITH TEMPORALLY SHIFTED LASERS SO JOURNAL OF CHEMICAL PHYSICS LA English DT Note ID VIBRATIONAL LEVELS C1 HARVARD SMITHSONIAN CTR ASTROPHYS,INST THEORET ATOM & MOLEC PHYS,CAMBRIDGE,MA 02138. NATL INST STAND & TECHNOL,DIV MOLEC SPECT,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 11 TC 32 Z9 32 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 FEB 15 PY 1992 VL 96 IS 4 BP 3339 EP 3341 DI 10.1063/1.461929 PG 3 WC Chemistry, Physical; Physics, Atomic, Molecular & Chemical SC Chemistry; Physics GA HE743 UT WOS:A1992HE74300097 ER PT J AU LARSEN, JC AF LARSEN, JC TI TRANSPORT AND HEAT-FLUX OF THE FLORIDA CURRENT AT 27-DEGREES-N DERIVED FROM CROSS-STREAM VOLTAGES AND PROFILING DATA - THEORY AND OBSERVATIONS SO PHILOSOPHICAL TRANSACTIONS OF THE ROYAL SOCIETY A-MATHEMATICAL PHYSICAL AND ENGINEERING SCIENCES LA English DT Article ID ELECTROMAGNETIC INDUCTION; INVERSE PROBLEM; ANNUAL CYCLE; FIELDS; OCEAN; SEA; 26.5-DEGREES-N; VARIABILITY; STRAITS; CABLE AB The variability in the volume transport of the Florida Current at 27-degrees N has been observed from the voltage measured between a point 16 km east of Jupiter Inlet, Florida and Settlement Point, Grand Bahama Island by the use of an abandoned communications cable. The voltage is caused by the separation of electric charges in the ocean that are caused by the Florida Current crossing the Earth's magnetic field (motional induction), by the electric currents induced in the ocean caused by time varying ionospheric and magnetospheric electric currents (geomagnetic induction), and by the voltage bias between the cable-ocean contacts caused by differences in the temperature, salinity and electrochemical state of the contacts. The geomagnetic-induced voltage was removed by the use of shore-based magnetic data and transfer functions. Changes in the voltage bias of the cable-ocean contact at Settlement Point were minimized by the use of a silver-silver-chloride electrode. The comparison of the daily mean motion-induced voltages with 137 daily profiling-derived transports, yields a voltage calibration factor of 24.42 +/- 0.56 Sv V-1, a correlation squared of 0.94, and a root mean square misfit of 0.77 Sv (1 Sv = 10(6) m3 s-1). The misfit is consistent with an error of 0.9 Sv in the voltage-derived transport estimated from the velocity and temperature profiling data, the electric current effects, and the profiling derived transport error. Hence the voltages accurately monitor the transport variations. The mean voltage-derived transports for the Florida Current at 27-degrees N is 32.3 +/- 3.2 Sv based on 4862 daily mean values from 1969 to 1990. The annual variation has a range of 4.4 Sv. There is no evidence since 1969 for any long-term trend in the transport but there are numerous shorter term variations as large as 15 Sv lasting from days to months. The mean northward heat flux is 1.30 +/- 0.13 PW derived from 130 days of profiling the velocity and temperature of the Florida Current and assuming the North Atlantic has a southward, velocity-weighted temperature of 9.4-degrees-C. The variations in heat flux are, essentially, due to the variations in transport because the velocity weighted temperature estimated by the profiling data has a nearly constant value of 19.1 +/- 0.6-degrees-C. RP NOAA, PACIFIC MARINE ENVIRONM LAB, SEATTLE, WA 98115 USA. NR 64 TC 139 Z9 140 U1 2 U2 8 PU ROYAL SOC PI LONDON PA 6-9 CARLTON HOUSE TERRACE, LONDON SW1Y 5AG, ENGLAND SN 1364-503X EI 1471-2962 J9 PHILOS T R SOC A JI Philos. Trans. R. Soc. A-Math. Phys. Eng. Sci. PD FEB 15 PY 1992 VL 338 IS 1650 BP 169 EP 236 DI 10.1098/rsta.1992.0007 PG 68 WC Multidisciplinary Sciences SC Science & Technology - Other Topics GA HE581 UT WOS:A1992HE58100001 ER PT J AU PIEPER, JB PRICE, JC MARTINIS, JM AF PIEPER, JB PRICE, JC MARTINIS, JM TI MEASUREMENT OF THE WEAK-LOCALIZATION COMPLEX CONDUCTIVITY AT 1 GHZ IN DISORDERED AG WIRES SO PHYSICAL REVIEW B LA English DT Note ID AC ELECTRIC-FIELD; PHASE COHERENCE; THIN-FILMS AB We have measured the complex magnetoconductivity of disordered quasi-one-dimensional Ag wires at 1 GHz and at 200 Hz. Because 1 GHz is of the same order as the dephasing rate, we have been able to observe the frequency dependence of weak localization. Both the real and imaginary parts of the conductivity at 1 GHz are in good agreement with theory. The data yield an accurate value for the electron diffusion constant, which is not well determined by dc measurements, and support the theory of weak localization at finite frequency, due originally to Gor'kov, Larkin, and Khmel'nitskii. C1 NIST,BOULDER,CO 80303. RP PIEPER, JB (reprint author), UNIV COLORADO,DEPT PHYS,CAMPUS BOX 390,BOULDER,CO 80309, USA. NR 20 TC 15 Z9 15 U1 0 U2 1 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 0163-1829 J9 PHYS REV B JI Phys. Rev. B PD FEB 15 PY 1992 VL 45 IS 7 BP 3857 EP 3860 DI 10.1103/PhysRevB.45.3857 PG 4 WC Physics, Condensed Matter SC Physics GA HE854 UT WOS:A1992HE85400098 ER PT J AU OBRIEN, WL JIA, J DONG, QY CALLCOTT, TA MUELLER, DR EDERER, DL AF OBRIEN, WL JIA, J DONG, QY CALLCOTT, TA MUELLER, DR EDERER, DL TI TEMPERATURE-DEPENDENCE OF ELECTRONIC-TRANSITIONS IN MGO, ALPHA-AL2O3, AND ALPHA-SIO2 - FINAL-STATE EFFECTS ON PHONON COUPLING SO PHYSICAL REVIEW B LA English DT Note ID PHOTOEMISSION AB We present temperature-dependent soft-x-ray emission and soft-x-ray absorption measurements on MgO, alpha-Al2O3, and alpha-SiO2. The measurements show in detail the final-state effect on phonon broadening for transitions involving the Mg 2P core state in MgO. In addition, we report the temperature dependence of emission and absorption features for MgO, alpha-Al2O3, and alpha-SiO2. The temperature dependence of the transitions involving the valence- and conduction-band states should be an important check on band-structure calculations. These results are compared to published temperature-dependent optical-reflectivity measurements. C1 NIST,GAITHERSBURG,MD 20899. RP OBRIEN, WL (reprint author), UNIV TENNESSEE,KNOXVILLE,TN 37996, USA. NR 16 TC 17 Z9 17 U1 0 U2 1 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 0163-1829 J9 PHYS REV B JI Phys. Rev. B PD FEB 15 PY 1992 VL 45 IS 7 BP 3882 EP 3885 DI 10.1103/PhysRevB.45.3882 PG 4 WC Physics, Condensed Matter SC Physics GA HE854 UT WOS:A1992HE85400105 ER PT J AU BLAISTENBAROJAS, E ZACHARIAH, MR AF BLAISTENBAROJAS, E ZACHARIAH, MR TI MOLECULAR-DYNAMICS STUDY OF CLUSTER GROWTH BY CLUSTER-CLUSTER COLLISIONS SO PHYSICAL REVIEW B LA English DT Article ID LENNARD-JONES CLUSTERS; SILICON CLUSTERS; SIMULATION; COAGULATION; PARTICLES; MODEL; IONS AB The formation of silicon clusters from cluster-cluster collisions at 2400 K is followed in time using molecular dynamics. It is found that during the first picosecond after collision, the clusters tend to agglomerate forming an intermediate complex in which the individuality of the original clusters is kept. However, during the following few picoseconds, atoms in the newly united cluster are highly mobile and agglomeration is lost. New clusters are hotter and with time they evaporate single atoms. This irreversible process by which the cluster accommodates the collision energy was studied as a function of the energy and the impact parameter. On average, the sticking coefficient is 1. C1 NATL INST STAND & TECHNOL,DIV PROC MEASUREMENTS,GAITHERSBURG,MD 20899. RP BLAISTENBAROJAS, E (reprint author), JOHNS HOPKINS UNIV,DEPT CHEM,BALTIMORE,MD 21218, USA. NR 34 TC 21 Z9 22 U1 0 U2 3 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 0163-1829 J9 PHYS REV B JI Phys. Rev. B PD FEB 15 PY 1992 VL 45 IS 8 BP 4403 EP 4408 DI 10.1103/PhysRevB.45.4403 PG 6 WC Physics, Condensed Matter SC Physics GA HF828 UT WOS:A1992HF82800053 ER PT J AU HEINEY, PA VAUGHAN, GBM FISCHER, JE COUSTEL, N COX, DE COPLEY, JRD NEUMANN, DA KAMITAKAHARA, WA CREEGAN, KM COX, DM MCCAULEY, JP SMITH, AB AF HEINEY, PA VAUGHAN, GBM FISCHER, JE COUSTEL, N COX, DE COPLEY, JRD NEUMANN, DA KAMITAKAHARA, WA CREEGAN, KM COX, DM MCCAULEY, JP SMITH, AB TI DISCONTINUOUS VOLUME CHANGE AT THE ORIENTATIONAL-ORDERING TRANSITION IN SOLID C-60 SO PHYSICAL REVIEW B LA English DT Note ID C-60 AB X-ray and neutron-diffraction measurements have been used to study the evolution of the lattice parameter of solid C60 through the orientational-ordering transition. The lattice parameter jumps by +0.044 +/- 0.004 angstrom on heating, indicating a strongly first-order transition. The average isobaric volume thermal-expansion coefficient both above and below the transition is 6.2 +/- 0.2 x 10(-5) K-1. We observe phase coexistence over a 5-K range, but little if any hysteresis. C1 UNIV PENN,RES STRUCT MATTER LAB,PHILADELPHIA,PA 19104. UNIV PENN,DEPT MAT SCI & ENGN,PHILADELPHIA,PA 19104. BROOKHAVEN NATL LAB,DEPT PHYS,UPTON,NY 11973. NATL INST STAND & TECHNOL,GAITHERSBURG,MD 20899. EXXON RES & ENGN CO,ANNANDALE,NJ 08801. UNIV PENN,DEPT CHEM,PHILADELPHIA,PA 19104. RP HEINEY, PA (reprint author), UNIV PENN,DEPT PHYS,PHILADELPHIA,PA 19104, USA. RI Vaughan, Gavin/B-1479-2010 NR 23 TC 163 Z9 163 U1 1 U2 6 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 0163-1829 J9 PHYS REV B JI Phys. Rev. B PD FEB 15 PY 1992 VL 45 IS 8 BP 4544 EP 4547 DI 10.1103/PhysRevB.45.4544 PG 4 WC Physics, Condensed Matter SC Physics GA HF828 UT WOS:A1992HF82800079 ER PT J AU ISAACS, WA MORRISON, MA AF ISAACS, WA MORRISON, MA TI MODIFIED EFFECTIVE RANGE THEORY AS AN ALTERNATIVE TO LOW-ENERGY CLOSE-COUPLING CALCULATIONS SO JOURNAL OF PHYSICS B-ATOMIC MOLECULAR AND OPTICAL PHYSICS LA English DT Article ID ELECTRON-MOLECULE COLLISIONS; SCATTERING CROSS-SECTIONS; ROTATIONAL-EXCITATION; POLAR-MOLECULES; POTENTIALS; H-2 AB We investigate the feasibility of using modified effective range theory to 'project' results of theoretical scattering calculations to energies so low that such calculations are numerically intractable. In particular, this theory as developed by Fabrikant in the body-frame fixed-nuclei formulation of electron scattering from non-polar molecules provides expansions of the reactance matrix that enable determination of the scattering length (and other parameters as needed) and total cross sections with greater accuracy and over a larger range of energies than do conventional implementations of such expansions for the total cross section. We have explored the viability, accuracy and potential problems of this stratagem for the e-H-2 and e-N2 systems; in both cases, careful use of these expansions enables calculation of highly accurate cross sections at very low energies without recourse to numerically problematic, CPU-intensive close-coupling calculations. C1 NATL INST STAND & TECHNOL, BOULDER, CO 80309 USA. UNIV OKLAHOMA, DEPT PHYS & ASTRON, NORMAN, OK 73019 USA. RP UNIV COLORADO, JOINT INST LAB ASTROPHYS, BOULDER, CO 80309 USA. NR 53 TC 13 Z9 13 U1 0 U2 0 PU IOP PUBLISHING LTD PI BRISTOL PA TEMPLE CIRCUS, TEMPLE WAY, BRISTOL BS1 6BE, ENGLAND SN 0953-4075 EI 1361-6455 J9 J PHYS B-AT MOL OPT JI J. Phys. B-At. Mol. Opt. Phys. PD FEB 14 PY 1992 VL 25 IS 3 BP 703 EP 725 DI 10.1088/0953-4075/25/3/018 PG 23 WC Optics; Physics, Atomic, Molecular & Chemical SC Optics; Physics GA HE526 UT WOS:A1992HE52600018 ER PT J AU ANGELL, JK AF ANGELL, JK TI EVIDENCE OF A RELATION BETWEEN EL-NINO AND QBO, AND FOR AN EL-NINO IN 1991-92 SO GEOPHYSICAL RESEARCH LETTERS LA English DT Article AB The possibility of a relation between El Nino and the quasi-biennial oscillation (QBO) in equatorial low stratosphere is investigated. Based on the 9 El Ninos and 16 quasi-biennial variations in 50 mb zonal wind at Singapore between 1954 and 1991, the sea-surface temperature (SST) in eastern equatorial Pacific has averaged nearly 0.5-degrees-C warmer one season after QBO east-wind maximum than 4-5 seasons before and after this maximum, but this difference in temperature is not statistically significant. Because of the difference in period of these oscillations (2 1/4 years on average in the case of the QBO, about 4 1/2 years on average in the case of El Nino), there can not be an El Nino associated with every QBO east-wind maximum, i.e., any relation between El Nino and QBO east-wind maximum has to "skip a beat" on occasion. This paper presents evidence for a pattern in this "skip", such that an El Nino is associated with a QBO east-wind maximum except when the El Nino associated with the previous east-wind maximum was a major one and/or the SST maximum followed the previous east-wind maximum by a few seasons. On the basis of this pattern an El Nino would not have been expected in 1989 or 1990 (because the El Nino of 1987 was a major one) but would be expected in 1991 or 1992 in association with the QBO east-wind maximum projected to occur in the northern summer of 1992. Comparison with earlier "skips" shows that an El Nino would be most likely before the next east-wind maximum, or at the end of 1991. Because it would follow the aborted warm event of 1990, it probably would not be a major El Nino. RP ANGELL, JK (reprint author), NOAA,ENVIRONM RES LAB,AIR RESOURCES LAB,1325 EW HIGHWAY,SILVER SPRING,MD 20910, USA. NR 13 TC 23 Z9 23 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 FEB 7 PY 1992 VL 19 IS 3 BP 285 EP 288 DI 10.1029/91GL02731 PG 4 WC Geosciences, Multidisciplinary SC Geology GA HC979 UT WOS:A1992HC97900017 ER PT J AU SERREZE, MC MASLANIK, JA BARRY, RG DEMARIA, TL AF SERREZE, MC MASLANIK, JA BARRY, RG DEMARIA, TL TI WINTER ATMOSPHERIC CIRCULATION IN THE ARCTIC BASIN AND POSSIBLE RELATIONSHIPS TO THE GREAT SALINITY ANOMALY IN THE NORTHERN NORTH-ATLANTIC SO GEOPHYSICAL RESEARCH LETTERS LA English DT Article ID SEA-ICE; FLUCTUATIONS; OCEAN AB Variations in synoptic activity are assessed in terms of potential influences on ice transport and indicators of shifts in the Arctic atmospheric circulation related to the "Great Salinity Anomaly" of the northern North Atlantic. Winter pressure anomalies suggest an increased contribution to the Fram Strait sea ice flux by multiyear ice from along the northern coasts of Greenland and Ellesmere Island. This may be related to a teleconnection involving changes in anticyclonicity over the central Arctic Ocean and Canadian Arctic Archipelago. RP SERREZE, MC (reprint author), UNIV COLORADO,NOAA,COOPERAT INST RES ENVIRONM SCI,DIV CRYOSPHER & POLAR PROC,BOULDER,CO 80309, USA. OI Barry, Roger/0000-0001-9239-0859 NR 17 TC 25 Z9 25 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 FEB 7 PY 1992 VL 19 IS 3 BP 293 EP 296 DI 10.1029/91GL02946 PG 4 WC Geosciences, Multidisciplinary SC Geology GA HC979 UT WOS:A1992HC97900019 ER PT J AU GILLES, MK ERVIN, KM HO, J LINEBERGER, WC AF GILLES, MK ERVIN, KM HO, J LINEBERGER, WC TI NEGATIVE-ION PHOTOELECTRON-SPECTROSCOPY OF HCF-, HCCL-, HCBR-, AND HCI- - PHOTOELECTRON ANGULAR-DISTRIBUTIONS AND NEUTRAL TRIPLET EXCITATION-ENERGIES SO JOURNAL OF PHYSICAL CHEMISTRY LA English DT Article ID LASER-INDUCED FLUORESCENCE; ELECTRIC-DIPOLE MOMENT; SUBSTITUTED CARBENES; RADICAL-ANIONS; ATOMIC OXYGEN; SINGLET; STATES; GAPS; PHOTODETACHMENT; CHF AB Photoelectron spectra and angular distributions are reported for the HCX(1A') + e <-- HCX-(XBAR 2A") and HCX(3A") + e- <-- HCX-(XBAR 2A") transitions of the halocarbenes (X = F, Cl, Br, and I). Taking photoelectron spectra at parallel and perpendicular laser polarizations with respect to the direction of the photoelectron detection allows us to distinguish the triplet transition from the overlapping singlet transition. Ab initio calculations used to simulate the Franck-Condon envelope for the triplet states combined with the experimental data predict that HCl has a triplet ground state. Best estimates for the triplet excitation energy based on these simulations are 14.9 +/- 0.4 kcal/mol (HCF), 4.2 +/- 2.5 kcal/mol (HCCl), 2.6 +/- 2.2 kcal/mol (HCBr), and -2 to -10 kcal/mol (HCI). Vibrational intervals of 850 +/- 60 cm-1 (HCCl), 725 +/- 70 cm-1 (HCBr), and 637 +/- 80 cm-1 (HCI) in the HCX(3A") + e- <-- HCX-(XBAR 2A") transitions are attributed to the C-X stretch of the neutral. Adiabatic electron affinities for the singlet states are found to be 0.542 +/- 0.005 (HCF), 0.535 +/- 0.005 (DCF), 1.210 +/- 0.005 (HCCl), 1.454 +/- 0.005 (HCBr), and 1.680 +/- 0.005 eV (HCI). The electron affinity of 3HCI is expected to lie between 1.25 and 1.59 eV. Asymmetry parameters are also reported for photoelectrons from F-, Br-, and I- (hv = 351.1 nm). C1 UNIV COLORADO,JOINT INST LAB ASTROPHYS,BOULDER,CO 80309. UNIV COLORADO,DEPT CHEM & BIOCHEM,BOULDER,CO 80309. NATL INST STAND & TECHNOL,BOULDER,CO 80309. NR 78 TC 118 Z9 118 U1 3 U2 12 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 FEB 6 PY 1992 VL 96 IS 3 BP 1130 EP 1141 DI 10.1021/j100182a021 PG 12 WC Chemistry, Physical SC Chemistry GA HC686 UT WOS:A1992HC68600021 ER PT J AU LEONE, SR AF LEONE, SR TI ORBITAL STEREOCHEMISTRY - DISCOVERING THE SYMMETRIES OF COLLISION PROCESSES SO ACCOUNTS OF CHEMICAL RESEARCH LA English DT Article ID ANGULAR-MOMENTUM; ALIGNMENT C1 UNIV COLORADO,JOINT INST LAB ASTROPHYS,BOULDER,CO 80309. UNIV COLORADO,DEPT CHEM & BIOCHEM,BOULDER,CO 80309. RP LEONE, SR (reprint author), NATL INST STANDARDS & TECHNOL,JOINT INST LAB ASTROPHYS,BOULDER,CO 80309, USA. NR 16 TC 24 Z9 24 U1 0 U2 2 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 SN 0001-4842 J9 ACCOUNTS CHEM RES JI Accounts Chem. Res. PD FEB PY 1992 VL 25 IS 2 BP 71 EP 76 DI 10.1021/ar00014a003 PG 6 WC Chemistry, Multidisciplinary SC Chemistry GA HD752 UT WOS:A1992HD75200003 ER PT J AU TANUMA, S POWELL, CJ PENN, DR AF TANUMA, S POWELL, CJ PENN, DR TI INELASTIC MEAN FREE PATHS OF LOW-ENERGY ELECTRONS IN SOLIDS SO ACTA PHYSICA POLONICA A LA English DT Article; Proceedings Paper CT 15TH INTERNATIONAL SEMINAR ON SURFACE PHYSICS CY MAY 20-25, 1991 CL PRZESIEKA, POLAND SP MINIST NATL EDUC POLAND, UNIV WROCLAW, RUTGERS STATE UNIV ID ATTENUATION LENGTHS; OPTICAL-DATA; DEPENDENCE; PHOTOELECTRONS; MODEL AB We present a summary of recent calculations of the electron inelastic mean free paths (IMFPs) of 50-2000 eV electrons in 27 elements and 15 inorganic compounds. These calculations are based in part on experimental optical data to represent the dependence of the inelastic scattering probability on energy loss and the theoretical Lindhard dielectric function to represent the dependence of the scattering probability on momentum transfer. The calculated IMFPs for the elements were fitted to a modified form of the Bethe equation for inelastic electron scattering in matter and the four parameters in this equation were empirically related to other material parameters. The resulting formula, designated TPP-2, provides a convenient means for predicting IMFPs in other materials. We have used two powerful integral equations or sum rules to evaluate the optical data on which our IMFP calculations are based. While the optical data for the elements satisfied these sum rules to an acceptable degree, there were significant deviations in the data for the compounds. In addition, differences in IMFPs calculated from the optical data for the compounds and the values predicted by TPP-2 correlated with the average errors of the optical data as determined by the sum rules. IMFPs calculated from TPP-2 for these compounds are therefore believed to be more reliable than IMFPs obtained from the imperfect optical data. C1 NBS,GAITHERSBURG,MD 20899. RP TANUMA, S (reprint author), NIPPON MIN CO LTD,ANAL RES CTR,3-17-35 NIIZO MINAMI,TODA,SAITAMA 335,JAPAN. RI Tanuma, Shigeo/H-2681-2011 NR 34 TC 13 Z9 13 U1 2 U2 6 PU POLISH ACAD SCIENCES INST PHYSICS PI WARSAW PA AL LOTNIKOW 32-46, 02-668 WARSAW, POLAND SN 0587-4246 J9 ACTA PHYS POL A JI Acta Phys. Pol. A PD FEB PY 1992 VL 81 IS 2 BP 169 EP 186 PG 18 WC Physics, Multidisciplinary SC Physics GA HQ934 UT WOS:A1992HQ93400001 ER PT J AU FREIMAN, SW AF FREIMAN, SW TI ADVANCED CERAMICS - A KEY TO FUTURE TECHNOLOGIES SO AMERICAN CERAMIC SOCIETY BULLETIN LA English DT Article RP FREIMAN, SW (reprint author), NATL INST STAND & TECHNOL,DIV CERAM,A256 MAT BLDG,GAITHERSBURG,MD 20899, USA. NR 0 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 FEB PY 1992 VL 71 IS 2 BP 180 EP 181 PG 2 WC Materials Science, Ceramics SC Materials Science GA HD328 UT WOS:A1992HD32800004 ER PT J AU MARCHIANDO, JF GEIST, J AF MARCHIANDO, JF GEIST, J TI SEPARATION BY ION-IMPLANTATION OF OXYGEN (SIMOX) STRUCTURES - ESTIMATING THICKNESSES SO APPLIED OPTICS LA English DT Article DE ELLIPSOMETRY; REFLECTOMETRY; MODELING; SIMOX AB The propagation of errors in the model parameters is compared for cases that analyze a simple separation by ion implantation of oxygen structure by using reflectometry and ellipsometry. Both methods give comparable values for the layer thicknesses. Both the radius of convergence and the values of uncertainly tend to be larger with reflectometry than with ellipsometry. RP MARCHIANDO, JF (reprint author), NATL INST STAND & TECHNOL,DIV SEMICOND ELECTR,GAITHERSBURG,MD 20899, USA. OI Geist, Jon/0000-0001-7749-318X NR 4 TC 0 Z9 0 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 FEB 1 PY 1992 VL 31 IS 4 BP 485 EP 487 PG 3 WC Optics SC Optics GA HB566 UT WOS:A1992HB56600021 PM 20720640 ER PT J AU SAYRE, EV YENER, KA JOEL, EC BARNES, IL AF SAYRE, EV YENER, KA JOEL, EC BARNES, IL TI STATISTICAL EVALUATION OF THE PRESENTLY ACCUMULATED LEAD ISOTOPE DATA FROM ANATOLIA AND SURROUNDING REGIONS SO ARCHAEOMETRY LA English DT Article DE AEGEAN; ANATOLIA; CHALCOLITHIC; BRONZE AGE; IRON AGE; LEAD ISOTOPE ANALYSIS; MULTIVARIATE STATISTICS; COPPER; LEAD; ORES; PROVENANCE ID BRONZE-AGE AB Several hundred new stable lead isotope ratio determinations of ore and slag specimens from ancient mining sites throughout Anatolia and of samples of artefacts of the Chalcolithic, Bronze Age and Early Iron Age from museum collections in Turkey and the United States have been combined with the accumulated published isotope determinations of such specimens from throughout the eastern Mediterranean and Aegean regions to form a data base of nearly 1000 analyses. It is the purpose of this paper to evaluate the practical effectiveness of using this now extensive data base to discriminate between the many sources of metals throughout this region and to propose methods to enhance this discrimination. By using the full three-dimensional isotopic data in multivariate statistical treatments and by separating isotopically resolvable source groups within some of the source areas and isolating statistically outlying specimens from them, it has been possible to characterize some ore sources more precisely and compactly and thereby achieve better resolution between ore sources. It has also been possible to isolate isotopically compatible artefact groups which possibly relate to ore sources that, as yet, have not been well defined by isotopic analysis. C1 NATL INST STAND & TECHNOL,GAITHERSBURG,MD. RP SAYRE, EV (reprint author), SMITHSONIAN INST,CTR MUSEUM SUPPORT,CONSERVAT ANALYT LAB,WASHINGTON,DC 20560, USA. NR 62 TC 45 Z9 45 U1 1 U2 2 PU OXFORD UNIV PI OXFORD PA RES LAB ARCHAEOL HIST ART 6 KEBLE RD, OXFORD, ENGLAND OX1 3QJ SN 0003-813X J9 ARCHAEOMETRY JI Archaeometry PD FEB PY 1992 VL 34 BP 73 EP 105 DI 10.1111/j.1475-4754.1992.tb00479.x PN 1 PG 33 WC Archaeology; Chemistry, Analytical; Chemistry, Inorganic & Nuclear; Geosciences, Multidisciplinary SC Archaeology; Chemistry; Geology GA KE658 UT WOS:A1992KE65800009 ER PT J AU HILL, JE AF HILL, JE TI CONSULTANTS OPTIONS ON CFCS AND ALTERNATIVE REFRIGERANTS - INTRODUCTION SO ASHRAE JOURNAL-AMERICAN SOCIETY OF HEATING REFRIGERATING AND AIR-CONDITIONING ENGINEERS LA English DT Editorial Material RP HILL, JE (reprint author), NATL INST STAND & TECHNOL,DIV BLDG ENVIRONM,BLDG & FIRE RES LAB,GAITHERSBURG,MD 20878, USA. NR 0 TC 0 Z9 0 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 FEB PY 1992 VL 34 IS 2 BP 34 EP 34 PG 1 WC Thermodynamics; Construction & Building Technology; Engineering, Mechanical SC Thermodynamics; Construction & Building Technology; Engineering GA HF141 UT WOS:A1992HF14100008 ER PT J AU HILL, JE AF HILL, JE TI TECHNICAL INNOVATIONS OF THE FUTURE SO ASHRAE JOURNAL-AMERICAN SOCIETY OF HEATING REFRIGERATING AND AIR-CONDITIONING ENGINEERS LA English DT Editorial Material RP HILL, JE (reprint author), NATL INST STAND & TECHNOL,GAITHERSBURG,MD 20878, 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 FEB PY 1992 VL 34 IS 2 BP 52 EP 52 PG 1 WC Thermodynamics; Construction & Building Technology; Engineering, Mechanical SC Thermodynamics; Construction & Building Technology; Engineering GA HF141 UT WOS:A1992HF14100033 ER PT J AU VARBERG, TD EVENSON, KM AF VARBERG, TD EVENSON, KM TI ACCURATE FAR-INFRARED ROTATIONAL FREQUENCIES OF CARBON-MONOXIDE SO ASTROPHYSICAL JOURNAL LA English DT Article DE LINE, IDENTIFICATION; MOLECULAR DATA; MOLECULAR PROCESSES ID HETERODYNE SPECTROSCOPY; ORION NEBULA; CO LINE; EMISSION; CONSTANTS AB High-resolution measurements of the pure rotational absorption spectrum of CO in its ground state are reported for the range J" = 5-37. A least-squares fit to this data set, augmented by previous microwave measurements of the J" = 0.4 rotational transitions by other workers, determined the following accurate values for the molecular constants (1 sigma errors of the last digits in parentheses): B0 = 57635.96826(12) MHz, D0 = 0.18350552(46) MHz, H0 = 1.7249(59) x 10(7) MHz, and L0 = -3.1(23) x 10(-13) MHz. A table of calculated CO rotational frequencies is given for the range J" = 0-45; these frequencies are accurate to less-than-or-equal-to 10 kHz (2-sigma) for J" less-than-or-equal-to 28. RP VARBERG, TD (reprint author), NATL INST STAND & TECHNOL,DIV TIME & FREQUENCY,325 BROADWAY,BOULDER,CO 80303, USA. NR 17 TC 78 Z9 78 U1 0 U2 8 PU UNIV CHICAGO PRESS PI CHICAGO PA 5720 S WOODLAWN AVE, CHICAGO, IL 60637 SN 0004-637X J9 ASTROPHYS J JI Astrophys. J. PD FEB 1 PY 1992 VL 385 IS 2 BP 763 EP 765 DI 10.1086/170983 PN 1 PG 3 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA HB576 UT WOS:A1992HB57600035 ER PT J AU GAYLEY, KG AF GAYLEY, KG TI PARTIALLY COHERENT SCATTERING IN STELLAR CHROMOSPHERES .1. EFFECTS ON RESONANCE LINE THERMALIZATION SO ASTROPHYSICAL JOURNAL SUPPLEMENT SERIES LA English DT Article DE LINE, FORMATION; RADIATIVE TRANSFER; STARS, CHROMOSPHERES ID PARTIAL REDISTRIBUTION; RADIATIVE-TRANSFER; LYMAN-ALPHA; MODELS; STARS; FORMULATION; EQUATIONS; BETA; SUN AB Photon scattering in the extended wings of many strong resonance lines is nearly coherent under typical stellar chromospheric conditions, with free-electron densities of about 10(12) cm-3 or less. When photon transport in these partially coherent wings dominates escape from the chromosphere, the depth of line thermalization will be strongly affected. Such effects of partial redistribution (PRD) are not accounted for in standard two-level thermalization models involving complete redistribution (CRD). We investigate the conditions necessary for partially coherent scattering to influence the thermalization depth, and approximate these effects in homogeneous slab atmospheres, using several common resonance lines as examples. For electron densities above 10(10) cm-3, we conclude that even when coherent scattering dominates the escape process, the thermalization depths of the strongest resonance lines of H, Ca II, and Mg II agree roughly with the standard result for complete redistribution over a Doppler profile. This occurs because of the importance of Doppler diffusion in frequency. However, at lower densities, such as for giant star chromospheres and QSO models, the results deviate strongly from the Doppler CRD case. C1 UNIV COLORADO,BOULDER,CO 80309. RP GAYLEY, KG (reprint author), NATL INST STAND & TECHNOL,JOINT INST LAB ASTROPHYS,BOULDER,CO 80309, USA. NR 45 TC 7 Z9 7 U1 0 U2 0 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 FEB PY 1992 VL 78 IS 2 BP 549 EP 564 DI 10.1086/191639 PG 16 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA HB067 UT WOS:A1992HB06700010 ER PT J AU MARKIN, VS TSONG, TY ROBERTSON, B ASTUMIAN, RD AF MARKIN, VS TSONG, TY ROBERTSON, B ASTUMIAN, RD TI MEMBRANE TRANSPORTERS AS FREE-ENERGY TRANSDUCERS - OPTIMIZATION OF ENERGY-TRANSFER SO BIOLOGICHESKIE MEMBRANY LA Russian DT Article ID OSCILLATING ELECTRIC-FIELD; (NA,K)-ATPASE; ACTIVATION; PROTEINS; PATTERNS; ENZYME AB A simple facilitated membrane transport system may be transformed into an active transport system if the transporter can effectively interact with an oscillating field and if it has different affinities for the transported ligand on the two sides of the membrane. By this mechanism, energy may be transmitted from an oscillating field and converted into other forms such as chemical potential or chemical bond energy. This extraordinary property of electroconformational coupling can be optimized to achieve an efficiency approaching that of the theoretical maximum 100%. The conditions necessary for high efficiency are that the field is of large amplitude, that the electrically induced conformational change of the transporter occurs at rates much great than those of the ligand association/dissociation reactions, that the rate of the membrane potential change lies between the two foregoing rates, and that the concentration gradient approaches the static head value. Beyond static head, energy is transduced oppositely, turning the transporter into a kind of electric field generator. All these results pertain to membrane transporters as well as enzymes which are commonly described by the Michaelis - Menten mechanism. C1 NATL INST STAND & TECHNOL,GAITHERSBURG,MD 20899. UNIV MINNESOTA,DEPT BIOCHEM,ST PAUL,MN 55108. RP MARKIN, VS (reprint author), AN FRUMKIN ELECTROCHEM INST,MOSCOW,USSR. NR 22 TC 0 Z9 0 U1 0 U2 0 PU MEZHDUNARODNAYA KNIGA PI MOSCOW PA 39 DIMITROVA UL., 113095 MOSCOW, RUSSIA SN 0233-4755 J9 BIOL MEMBRANY JI Biol. Membr. PD FEB PY 1992 VL 9 IS 2 BP 214 EP 222 PG 9 WC Cell Biology SC Cell Biology GA HW740 UT WOS:A1992HW74000010 ER PT J AU SKRTIC, D EANES, ED AF SKRTIC, D EANES, ED TI MEMBRANE-MEDIATED PRECIPITATION OF CALCIUM-PHOSPHATE IN MODEL LIPOSOMES WITH MATRIX VESICLE-LIKE LIPID-COMPOSITION SO BONE AND MINERAL LA English DT Article DE CALCIUM PHOSPHATES; LIPOSOMES; MATRIX VESICLES; MINERALIZATION ID CONTAINING ANIONIC LIPOSOMES; EPIPHYSEAL CARTILAGE; AQUEOUS SUSPENSIONS; PYROPHOSPHATASE; ATPASE AB The present study examined calcium phosphate precipitation in aqueous suspensions of artificial liposomes which closely resembled matrix vesicles (MV) in membrane lipid composition. At 22-degrees-C, the liposomes per se did not initiate precipitation in the suspending medium for up to 120 h when the latter was made supersaturated with respect to hydroxyapatite (2.25 mM Ca2+, 1.5 mM PO4, 240 mosmol, pH 7.4). Likewise, the suspending medium remained stable for up to 72 h when precipitation was induced within the aqueous interiors of the liposomes by encapsulating pH 7.4-buffered 50 mM PO4 solutions in the interior spaces and making the enclosing membranes permeable to external solution Ca2+ ions with the ionophore X-537A. However, extraliposomal precipitation readily occurred under these latter conditions when phosphatidylserine (PS) and sphingomyelin (Sph) were deleted from the MV-like lipid formulation used to prepare the liposomes. These results suggest that lipidic membrane constituents such as PS and Sph may have a controlling influence on MV-mediated calcification in vivo by affecting the release of intravesicularly formed mineral crystals into the extracellular matrix space where they can subsequently grow and proliferate. C1 NATL INST STAND & TECHNOL,NIDR,RES ASSOCIATE PROGRAM,BONE RES BRANCH,BLDG 224,ROOM A143,GAITHERSBURG,MD 20899. NR 24 TC 23 Z9 23 U1 0 U2 4 PU ELSEVIER SCI IRELAND LTD PI CLARE PA CUSTOMER RELATIONS MANAGER, BAY 15, SHANNON INDUSTRIAL ESTATE CO, CLARE, IRELAND SN 0169-6009 J9 BONE MINER JI Bone Miner. PD FEB PY 1992 VL 16 IS 2 BP 109 EP 119 DI 10.1016/0169-6009(92)90881-D PG 11 WC Endocrinology & Metabolism SC Endocrinology & Metabolism GA HF847 UT WOS:A1992HF84700003 PM 1576486 ER PT J AU BOE, BA STITH, JL SMITH, PL HIRSCH, JH HELSDON, JH DETWILER, AG ORVILLE, HD MARTNER, BE REINKING, RF MEITIN, RJ BROWN, RA AF BOE, BA STITH, JL SMITH, PL HIRSCH, JH HELSDON, JH DETWILER, AG ORVILLE, HD MARTNER, BE REINKING, RF MEITIN, RJ BROWN, RA TI THE NORTH-DAKOTA THUNDERSTORM PROJECT - A COOPERATIVE STUDY OF HIGH-PLAINS THUNDERSTORMS SO BULLETIN OF THE AMERICAN METEOROLOGICAL SOCIETY LA English DT Article ID SILVER-IODIDE; CUMULUS; CLOUDS; CCOPE AB The North Dakota Thunderstorm Project was conducted in the Bismarck, North Dakota, area from 12 June through 22 July 1989. The project deployed Doppler radars, cloud physics aircraft, and supporting instrumentation to study a variety of aspects of convective clouds. These included transport and dispersion; entrainment; cloud-ice initiation and evolution; storm structure, dynamics, and kinematics; atmospheric chemistry; and electrification. Of primary interest were tracer experiments that identified and tracked specific regions within evolving clouds as a means of investigating the transport, dispersion, and activation of ice-nucleating agents as well as studying basic transport and entrainment processes. Tracers included sulfur hexafluoride (SF6), carbon monoxide, ozone, radar chaff, and silver iodide. Doppler radars were used to perform studies of all scales of convection, from first-echo cases to a mesoscale convective system. An especially interesting dual-Doppler study of two splitting thunderstorms has resulted. The objectives of the various project experiments and the specific facilities employed are described. Project highlights and some preliminary results are also presented. C1 UNIV N DAKOTA,CTR AEROSP SCI,GRAND FORKS,ND 58201. S DAKOTA SCH MINES & TECHNOL,INST ATMOSPHER SCI,RAPID CITY,SD 57701. NOAA,ENVIRONM RES LAB,NATL SEVERE STORMS LAB,NORMAN,OK 73069. UNIV COLORADO,NOAA,COOPERAT INST RES ENVIRONM SCI,BOULDER,CO 80309. NOAA,ENVIRONM RES LAB,WAVE PROPAGAT LAB,BOULDER,CO 80303. RP BOE, BA (reprint author), N DAKOTA STATE WATER COMMISS,ATMOSPHER RESOURCE BOARD,BISMARCK,ND, USA. NR 33 TC 23 Z9 25 U1 0 U2 2 PU AMER METEOROLOGICAL SOC PI BOSTON PA 45 BEACON ST, BOSTON, MA 02108-3693 SN 0003-0007 J9 B AM METEOROL SOC JI Bull. Amer. Meteorol. Soc. PD FEB PY 1992 VL 73 IS 2 BP 145 EP 160 DI 10.1175/1520-0477(1992)073<0145:TNDTPA>2.0.CO;2 PG 16 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA HE464 UT WOS:A1992HE46400001 ER PT J AU MARTNER, BE RAUBER, RM RASMUSSEN, RM PRATER, ET RAMAMURTHY, MK AF MARTNER, BE RAUBER, RM RASMUSSEN, RM PRATER, ET RAMAMURTHY, MK TI IMPACTS OF A DESTRUCTIVE AND WELL-OBSERVED CROSS-COUNTRY WINTER STORM SO BULLETIN OF THE AMERICAN METEOROLOGICAL SOCIETY LA English DT Article AB A winter storm that crossed the continental United States in mid-February 1990 produced hazardous weather across a vast area of the nation. A wide range of severe weather was reported, including heavy snowfall; freezing rain and drizzle; thunderstorms with destructive winds, lightning, large hail, and tornadoes; prolonged heavy rain with subsequent flooding; frost damage to citrus orchards; and sustained destructive winds not associated with thunderstorms. Low-end preliminary estimates of impacts included 9 deaths, 27 injuries, and $120 million of property damage. At least 35 states and southeastern Canada were adversely affected. The storm occurred during the field operations of four independent atmospheric research projects that obtained special, detailed observations of it from the Rocky Mountains to the eastern Great Lakes. C1 NATL CTR ATMOSPHER RES,BOULDER,CO 80307. UNIV N DAKOTA,DEPT ATMOSPHER SCI,GRAND FORKS,ND 58202. UNIV ILLINOIS,DEPT ATMOSPHER SCI,URBANA,IL 61801. RP MARTNER, BE (reprint author), NOAA,ENVIRONM RES LAB,WAVE PROPAGAT LAB,BOULDER,CO 80303, USA. NR 13 TC 18 Z9 18 U1 0 U2 3 PU AMER METEOROLOGICAL SOC PI BOSTON PA 45 BEACON ST, BOSTON, MA 02108-3693 SN 0003-0007 J9 B AM METEOROL SOC JI Bull. Amer. Meteorol. Soc. PD FEB PY 1992 VL 73 IS 2 BP 169 EP 172 DI 10.1175/1520-0477(1992)073<0169:IOADAW>2.0.CO;2 PG 4 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA HE464 UT WOS:A1992HE46400003 ER PT J AU HEDDINGHAUS, TR LECOMTE, DM AF HEDDINGHAUS, TR LECOMTE, DM TI A CENTURY OF MONITORING WEATHER AND CROPS - THE-WEEKLY-WEATHER-AND-CROP-BULLETIN SO BULLETIN OF THE AMERICAN METEOROLOGICAL SOCIETY LA English DT Article ID DROUGHT AB Publication of a national weekly weather summary called the Weekly Weather Chronicle began in 1872. This summary was the precursor of today's Weekly Weather and Crop Bulletin (WWCB), a publication that reports global weather and climate conditions relevant to agricultural interests, as well as current national activities and assessments of crop and livestock conditions. The WWCB is produced by the Joint Agricultural Weather Facility (JAWF), a world agricultural weather information center located in the U.S. Department of Agriculture (USDA) headquarters in Washington, D.C., and jointly staffed by units of the National Oceanic and Atmospheric Administration's Climate Analysis Center and USDA's World Agricultural Outlook Board and National Agricultural Statistics Service. Besides featuring charts and tables (e.g., temperature and precipitation maps and crop progress and condition tables), the WWCB contains summaries and special stories highlighting significant weather events affecting agriculture, such as droughts, torrential rains, floods, unusual warmth, heat waves, severe freezes, heavy snowfall, blizzards, damaging storms, and hurricanes. RP HEDDINGHAUS, TR (reprint author), NOAA,NATL WEATHER SERV,NATL METEOROL CTR,CTR CLIMATE ANAL,WASHINGTON,DC 20233, USA. NR 7 TC 1 Z9 1 U1 1 U2 2 PU AMER METEOROLOGICAL SOC PI BOSTON PA 45 BEACON ST, BOSTON, MA 02108-3693 SN 0003-0007 J9 B AM METEOROL SOC JI Bull. Amer. Meteorol. Soc. PD FEB PY 1992 VL 73 IS 2 BP 180 EP 186 DI 10.1175/1520-0477(1992)073<0180:ACOMWA>2.0.CO;2 PG 7 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA HE464 UT WOS:A1992HE46400005 ER PT J AU SIEW, C GRUNINGER, SE CHOW, LC BROWN, WE AF SIEW, C GRUNINGER, SE CHOW, LC BROWN, WE TI PROCEDURE FOR THE STUDY OF ACIDIC CALCIUM-PHOSPHATE PRECURSOR PHASES IN ENAMEL MINERAL FORMATION SO CALCIFIED TISSUE INTERNATIONAL LA English DT Article DE ENAMEL; FLUORIDE; HYDROXYAPATITE; MAGNESIUM; OCTACALCIUM PHOSPHATE; 32PHOSPHATE ID HYDROLYSIS; FLUORIDE; SERUM AB Considerable evidence suggests that an acidic calcium phosphate, such as octacalcium phosphate (OCP) or brushite, is involved as a precursor in enamel and other hard tissue formation. Additionally, there is in vitro evidence suggesting that fluoride accelerates and magnesium inhibits the hydrolysis of OCP to hydroxyapatite (OHAp). As the amount of OCP or brushite in enamel cannot be measured directly in the presence of an excess of hydroxyapatite, a procedure was developed that allows for their indirect in vivo quantification as pyrophosphate. This permits study of the effects of fluoride and magnesium ions on enamel mineral synthesis. Rat incisor calcium phosphate was labeled by intraperitoneal injection of (NaH232PO4)-P-32. The rats were then subjected to various fluoride and magnesium treatments with subcutaneous implanted osmotic pumps. They were then killed at predetermined intervals; the nascent sections of the incisors were collected, cleaned, and pyrolyzed at 500-degrees-C for 48 hours to convert acidic calcium phosphates to calcium pyrophosphate; the pyrophosphate was separated from orthophosphate by anion-exchange chromatography; and the resulting fractions were counted by liquid scintillation spectrometry. The activities of the pyro- and orthophosphate fractions were used to calculate the amount of acidic calcium phosphate present in the nascent mineral. The results demonstrated that the percentage of radioactive pyrophosphate in nascent incisors decreased with time, with increasing serum F- concentration, and with decreasing serum magnesium content. The technique described here should prove to be a powerful new tool for studying the effects of various agents on biological mineral formation. C1 NATL INST STAND & TECHNOL,AMER DENT ASSOC HLTH FDN,PAFFENBARGER RES CTR,GAITHERSBURG,MD 20899. RP SIEW, C (reprint author), AMER DENT ASSOC,HLTH FDN RES INST,211 E CHICAGO AVE,CHICAGO,IL 60611, USA. FU NIDCR NIH HHS [DE 05030] NR 28 TC 26 Z9 26 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 FEB PY 1992 VL 50 IS 2 BP 144 EP 148 DI 10.1007/BF00298792 PG 5 WC Endocrinology & Metabolism SC Endocrinology & Metabolism GA HA139 UT WOS:A1992HA13900012 PM 1315187 ER PT J AU WEISS, AW AF WEISS, AW TI THE CALCULATION OF ATOMIC OSCILLATOR-STRENGTHS - THE LITHIUM ATOM REVISITED SO CANADIAN JOURNAL OF CHEMISTRY LA English DT Article DE CONFIGURATION INTERACTION; CORRELATION; OSCILLATOR STRENGTH ID HELIUM ISOELECTRONIC SEQUENCE; VARIATIONAL CALCULATIONS; STATES; TRANSITIONS; LI AB Extensive configuration interaction calculations have been done for the ground and first excited states of neutral lithium and singly ionized beryllium. While the calculations reproduce the ionization and excitation energies to within 3 cm-1 for Li and 10 cm-1 for Be+, the main purpose of this work is the accurate evaluation of the 2s-2p resonance line oscillator strength. The calculated value of 0.7478 agrees to within less than 1% with the very accurate laser excitation lifetime measurement of 0.7416 +/- 0.0012. However, internal consistency checks of the accuracy of these calculations suggest that more precise calculations are unlikely to reduce this discrepancy significantly. Furthermore, when placed together with other independent calculations that should be of comparable, if not better, accuracy, all theoretical predictions strongly indicate an f-value of 0.7475 +/- 0.0010, which differs from the experiment by 4 experimental standard deviations. RP NATL INST STAND & TECHNOL, GAITHERSBURG, MD 20899 USA. NR 26 TC 35 Z9 35 U1 0 U2 0 PU CANADIAN SCIENCE PUBLISHING, NRC RESEARCH PRESS PI OTTAWA PA 65 AURIGA DR, SUITE 203, OTTAWA, ON K2E 7W6, CANADA SN 0008-4042 EI 1480-3291 J9 CAN J CHEM JI Can. J. Chem. PD FEB PY 1992 VL 70 IS 2 BP 456 EP 463 DI 10.1139/v92-066 PG 8 WC Chemistry, Multidisciplinary SC Chemistry GA JD653 UT WOS:A1992JD65300028 ER PT J AU STEVENS, WJ KRAUSS, M BASCH, H JASIEN, PG AF STEVENS, WJ KRAUSS, M BASCH, H JASIEN, PG TI RELATIVISTIC COMPACT EFFECTIVE POTENTIALS AND EFFICIENT, SHARED-EXPONENT BASIS-SETS FOR THE 3RD-ROW, 4TH-ROW, AND 5TH-ROW ATOMS SO CANADIAN JOURNAL OF CHEMISTRY-REVUE CANADIENNE DE CHIMIE LA English DT Article DE MODEL POTENTIALS; EFFECTIVE CORE POTENTIALS; TRANSITION METALS; RELATIVISTIC CALCULATIONS ID EFFECTIVE CORE POTENTIALS; SPIN-ORBIT OPERATORS; MAIN GROUP ELEMENTS; ADJUSTED ABINITIO PSEUDOPOTENTIALS; MOLECULAR-STRUCTURE CALCULATIONS; RARE-EARTH ELEMENTS; MODEL POTENTIALS; POLARIZATION POTENTIALS; ELECTRONIC-STRUCTURE; VALENCE CORRELATION AB Relativistic compact effective potentials (RCEP), which replace the atomic core electrons in molecular calculations, have been derived from numerical Dirac-Fock atomic wavefunctions using shape-consistent valence pseudo-orbitals and an optimizing procedure based on an energy-overlap functional. Potentials are presented for the third-, fourth-, and fifth-row atoms of the Periodic Table (excluding the lanthanide series). The efficiency of molecular calculations is enhanced by using compact Gaussian expansions (no more than three terms) to represent the radial components of the potentials, and energy-optimized, shared-exponent, contracted-Gaussian atomic orbital basis sets. Transferability of the potentials has been tested by comparing calculated atomic excitation energies and ionization potentials with values obtained from numerical relativistic Hartree-Fock calculations. For the alkali and alkaline earth atoms, core polarization potentials (CPP) have been derived which may be added to the RCEP to make possible accurate molecular calculations without explicitly including core-valence correlating configurations in the wave function. C1 BAR ILAN UNIV,DEPT CHEM,IL-52100 RAMAT GAN,ISRAEL. NATL INST STAND & TECHNOL,DIV MOLEC SPECT,GAITHERSBURG,MD 20899. RP STEVENS, WJ (reprint author), NATL INST STAND & TECHNOL,CTR ADV RES BIOTECHNOL,9600 GUDELSKY DR,ROCKVILLE,MD 20850, USA. NR 97 TC 1841 Z9 1868 U1 7 U2 62 PU NATL RESEARCH COUNCIL CANADA PI OTTAWA PA RESEARCH JOURNALS, MONTREAL RD, OTTAWA ON K1A 0R6, CANADA SN 0008-4042 J9 CAN J CHEM JI Can. J. Chem.-Rev. Can. Chim. PD FEB PY 1992 VL 70 IS 2 BP 612 EP 630 DI 10.1139/v92-085 PG 19 WC Chemistry, Multidisciplinary SC Chemistry GA JD653 UT WOS:A1992JD65300047 ER PT J AU FAHNENSTIEL, GL CARRICK, HJ AF FAHNENSTIEL, GL CARRICK, HJ TI PHOTOTROPHIC PICOPLANKTON IN LAKES HURON AND MICHIGAN - ABUNDANCE, DISTRIBUTION, COMPOSITION, AND CONTRIBUTION TO BIOMASS AND PRODUCTION SO CANADIAN JOURNAL OF FISHERIES AND AQUATIC SCIENCES LA English DT Article ID FRESH-WATER ECOSYSTEMS; CHROOCOCCOID CYANOBACTERIA; AUTOTROPHIC PICOPLANKTON; VERTICAL-DISTRIBUTION; SEASONAL ABUNDANCE; PHYTOPLANKTON CELL; ALGAL PICOPLANKTON; NORTH-ATLANTIC; SIZE FRACTIONS; MARINE AB The phototropic picoplankton communities of Lakes Huron and Michigan were studied from 1986 through 1988. Abundances in the surface-mixed layer ranged from 10 000 to 220 000 cells.mL-1 with a seasonal maximum during the period of thermal stratification. During thermal stratification, maximum abundances were generally found within the metalimnion/hypolimnion at depths corresponding to the 0.6-6.0% isolumes. The picoplankton community was dominated by single phycoerythrin-containing (PE) Synechococcus (59%) with lesser amounts of chlorophyll fluorescing cells (21%), PE colonial Synechococcus-like cells (11%), other PE colonial Chroococcales (6%), and other cells (3%). Single PE Synechococcus was abundant throughout the year whereas chlorophyll-fluorescing and colonial cyanobacteria were more abundant during the periods of spring isothermal mixing and summer stratification, respectively. Picoplankton accounted for an average of 10% (range 0.5-50%) of phototrophic biomass. Phototrophic organisms that passed 1-, 3-, and 10-mu-m screens were responsible for an average of 17% (range 6-43%), 40% (21-65%), and 70% (52-90%) of primary production. Maximum contributions of < 1, < 3, and < 10-mu-m size fractions occurred during the period of thermal stratification. Primary production by phototrophic picoplankton was found to equal production in the < 1-mu-m size fraction. RP FAHNENSTIEL, GL (reprint author), NOAA,GREAT LAKES ENVIRONM RES LAB,2205 COMMONWEALTH BLVD,ANN ARBOR,MI 48105, USA. NR 65 TC 75 Z9 78 U1 0 U2 4 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 FEB PY 1992 VL 49 IS 2 BP 379 EP 388 DI 10.1139/f92-043 PG 10 WC Fisheries; Marine & Freshwater Biology SC Fisheries; Marine & Freshwater Biology GA HE016 UT WOS:A1992HE01600020 ER PT J AU KRONE, CA STEIN, JE VARANASI, U AF KRONE, CA STEIN, JE VARANASI, U TI ESTIMATION OF LEVELS OF METABOLITES OF AROMATIC-HYDROCARBONS IN FISH-TISSUES BY HPLC/FLUORESCENCE ANALYSIS SO CHEMOSPHERE LA English DT Article ID SOLE PAROPHRYS-VETULUS; SEDIMENT-ASSOCIATED XENOBIOTICS; C-14 POLYCHLORINATED-BIPHENYLS; PUGET-SOUND; SIMULTANEOUS EXPOSURE; H-3 BENZOPYRENE; HEPATIC-LESIONS; WASHINGTON; BILE; DISPOSITION AB Aromatic hydrocarbons (AHs) are extensively metabolized into oxidized products by fish and mammals. Some metabolites are more toxic than the parent AHs; however, currently there are no methods to screen tissues of fish or other marine species for the presence of AH metabolites. In the present study, a relatively rapid, semiquantitative method that combines enzymatic hydrolysis, methylene chloride extraction and hexane/potassium hydroxide partitioning with HPLC/fluorescence analysis, was developed for the estimation of the concentrations of polar fluorescent aromatic compounds (polar FACs; e.g., AH metabolites) in fish tissues. Liver and muscle from rock sole (Lepidopsetta bilineata) exposed to Prudhoe Bay crude oil in the laboratory were analyzed. Tissues from English sole (Parophrys vetulus) sampled at two sites (one nonurban reference and one AH-contaminated) in Puget Sound, WA were also analyzed. The concentrations of polar FACs in liver and muscle of PBCO-exposed rock sole were linearly proportional to dose. Also, in both species exposed to contaminants, the concentrations of polar FACs in liver were approximately 15 times as great as those in muscle. Polar FACs, however, were not detected in muscle of English sole collected at either the contaminated or reference site, suggesting that polar FACs in naturally exposed animals may be present only at low concentrations unless exposed to high levels of contaminants such as AHs. Thus, the present method can detect, estimate and rank the relative concentrations of polar FACs (e.g., AH metabolites) in tissues, such as liver and muscle of fish. The method augments our ability to assess environmental exposure to potentially toxic contaminants such as AHs. RP KRONE, CA (reprint author), NOAA,NATL MARINE FISHERIES SERV,NORTHWEST FISHERIES SCI CTR,DIV ENVIRONM CONSERVAT,SEATTLE,WA 98112, USA. NR 22 TC 10 Z9 11 U1 0 U2 2 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD, ENGLAND OX5 1GB SN 0045-6535 J9 CHEMOSPHERE JI Chemosphere PD FEB PY 1992 VL 24 IS 4 BP 497 EP 510 DI 10.1016/0045-6535(92)90424-P PG 14 WC Environmental Sciences SC Environmental Sciences & Ecology GA HM030 UT WOS:A1992HM03000014 ER PT J AU SIJELMASSI, R LINN, RJ AF SIJELMASSI, R LINN, RJ TI GUIDELINES FOR USING ESTELLE TO SPECIFY OSI SERVICES AND PROTOCOLS SO COMPUTER NETWORKS AND ISDN SYSTEMS LA English DT Article DE BASIC REFERENCE MODEL (BRM); COMPUTER COMMUNICATION PROTOCOLS; ESTELLE; FORMAL DESCRIPTION TECHNIQUES (FDT); OPEN SYSTEMS INTERCONNECTION (OSI) AB The Open Systems Interconnection Basic Reference Model describes basic structures and mechanisms which are a framework for the specification of computer communication protocols and services. Estelle is a formal description technique for specifying such protocols and services. A general design method is presented to specify protocol concepts using Estelle. Emphasis is put on a modular approach to the specification of protocols and services based on reusable descriptions of general service facilities and protocol functions in Estelle. Also stressed is the idea that protocols are implementations of services. A service description may be refined into a protocol specification, if a precise description of the service provided by lower layers is available. This approach is illustrated by example. C1 US DEPT COMMERCE,NATL INST STAND & TECHNOL,NATL COMP SYST LAB,GAITHERSBURG,MD 20899. NR 19 TC 1 Z9 1 U1 0 U2 0 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0169-7552 J9 COMPUT NETWORKS ISDN JI Comput. Netw. ISDN Syst. PD FEB PY 1992 VL 23 IS 5 BP 343 EP 362 DI 10.1016/0169-7552(92)90012-F PG 20 WC Computer Science, Information Systems; Engineering, Electrical & Electronic; Telecommunications SC Computer Science; Engineering; Telecommunications GA HJ451 UT WOS:A1992HJ45100003 ER PT J AU BISAGNI, JJ AF BISAGNI, JJ TI DIFFERENCES IN THE ANNUAL STRATIFICATION CYCLE OVER SHORT SPATIAL SCALES ON SOUTHERN GEORGES BANK SO CONTINENTAL SHELF RESEARCH LA English DT Article ID ATLANTIC BIGHT; FRONTS; WATER; TEMPERATURE; CIRCULATION; CURRENTS; SEAWATER; SIDES; RING; SEA AB Analysis of hydrographic data collected during 1977-1978 at six locations on southern Georges Bank revealed differences in the sinusoidally-modeled mean seasonal hydrographic cycles over short cross-bank spatial scales. In depths of less than 60 m, vertical stratification remained weak year-round, with no seasonal cycle. At greater depths, a transition to a stratified water column occurred from late spring to early autumn. However, statistically-significant differences exist between the mean hydrographic cycles derived from data collected in two contiguous seasonally-stratified zones located within the deeper region. In 60-80 m depths: (1) the mean cycle of the maximum density gradient in the seasonal pycnocline was dominated by a one cycle-per-year model; (2) the maximum density gradient varied by almost two orders of magnitude, from a January minimum to a late July maximum; and (3) the mean depth of the maximum density gradient remained near 20 m year-round. In 80-100 m depths: (1) the mean cycles of both the maximum density gradient and pycnocline depth were dominated by a one cycle-per-year model; (2) the maximum density gradient varied by only one order of magnitude; and (3) the mean depth of the maximum density gradient varied from 20 m in early June to 60 m in late December when the water column is well mixed. The cross-bank transition from well-mixed to seasonally-stratified waters agrees with the Simpson-Hunter stratification parameter computed by other workers for the study domain and, thus, to first order is consistent with existing one-dimensional models for tidally-mixed seas. Variations between hydrographic cycles noted within the seasonally-stratified waters may be due to the presence of the "cold-band" and on-bank advection of slope waters, thus modifying the one-dimensional assumptions. RP BISAGNI, JJ (reprint author), NOAA,NATL MARINE FISHERIES SERV,NARRAGANSETT,RI 02882, USA. NR 40 TC 16 Z9 16 U1 0 U2 0 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD, ENGLAND OX5 1GB SN 0278-4343 J9 CONT SHELF RES JI Cont. Shelf Res. PD FEB-MAR PY 1992 VL 12 IS 2-3 BP 415 EP 435 DI 10.1016/0278-4343(92)90039-M PG 21 WC Oceanography SC Oceanography GA HH775 UT WOS:A1992HH77500010 ER PT J AU FIEDLER, PC CHAVEZ, FP BEHRINGER, DW REILLY, SB AF FIEDLER, PC CHAVEZ, FP BEHRINGER, DW REILLY, SB TI PHYSICAL AND BIOLOGICAL EFFECTS OF LOS-NINOS IN THE EASTERN TROPICAL PACIFIC, 1986-1989 SO DEEP-SEA RESEARCH PART A-OCEANOGRAPHIC RESEARCH PAPERS LA English DT Article ID EL-NINO; OCEAN; TEMPERATURE; ATMOSPHERE; WATERS; CYCLE; WINDS AB The eastern tropical Pacific Ocean was surveyed in August-November 1986, 1987, 1988 and 1989 as part of a long-term program to monitor dolphin stocks. Temperature, salinity, chlorophyll and nutrients were monitored to help interpret variability in dolphin stock estimates. The four surveys reveal major environmental changes during the moderate 1987 El Nino and the cold La Nina episode that followed in 1988. During the "onset" phase of El Nino in fall 1986, surface temperatures were up to 1.5-degrees-C above normal in equatorial water, but near normal in tropical water north of the equator. The equatorial thermocline ridge was deepened by 10-30 m. During the "mature" phase of Et Nino in fall 1987, surface temperatures anomalies were up to +2.5-degrees-C in equatorial water and about +1-degrees-C in tropical water. Thermocline topography was anomalously flat. Surface chlorophyll and nutrient concentrations declined by 11-48% compared to 1986, with the greatest declines occurring in coastal and equatorial upwelling systems and along the countercurrent thermocline ridge. During La Nina 1988. equatorial surface temperatures were up to 2.5-degrees-C below normal and the equatorial thermocline ridge was 10-50 m more shallow than normal. Chlorophyll and nitrate concentrations increased by 58-65% compared to 1987. In 1989. surface temperature was within +/- 1-degrees-C of normal throughout the study area and chlorophyll concentrations were similar to those observed in 1986. Changes in nutrient availability and biological productivity during the El Nino/La Nina cycle were caused by variations in both the rate of wind-driven upwelling and in the nutrient content of subsurface water entrained by upwelling. C1 NOAA,ENVIRONM RES LABS,ATLANTIC OCEANOGR & METEOROL LAB,MIAMI,FL 33149. MONTEREY BAY AQUARIUM RES INST,PACIFIC GROVE,CA 93950. RP FIEDLER, PC (reprint author), NOAA,NATL MARINE FISHERIES SERV,SW FISHERIES SCI CTR,POB 271,LA JOLLA,CA 92038, USA. NR 42 TC 52 Z9 53 U1 1 U2 5 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 FEB PY 1992 VL 39 IS 2A BP 199 EP 219 DI 10.1016/0198-0149(92)90105-3 PG 21 WC Oceanography SC Oceanography GA HH586 UT WOS:A1992HH58600007 ER PT J AU SHEARER, KD ASGARD, T AF SHEARER, KD ASGARD, T TI THE EFFECT OF WATER-BORNE MAGNESIUM ON THE DIETARY MAGNESIUM REQUIREMENT OF THE RAINBOW-TROUT (ONCORHYNCHUS-MYKISS) SO FISH PHYSIOLOGY AND BIOCHEMISTRY LA English DT Article DE MAGNESIUM REQUIREMENT; WATER-BORNE MAGNESIUM; DIETARY MAGNESIUM REQUIREMENT; RAINBOW TROUT ID TILAPIA OREOCHROMIS-NILOTICUS; SALMO-GAIRDNERI; GROWTH; AVAILABILITY AB Rainbow trout (Oncorhynchus mykiss) (mean initial weight 0.84 g) were fed diets containing graded levels of magnesium (Mg) (78 to 725-mu-g/g) while being exposed to one of several levels in the rearing water (1.4 to 1000 mg/l). Uptake of Mg from the water, in Mg-deficient fish, was linearly related to the water Mg concentrated. It appears that the fish's Mg requirement can be met from either or both the diet or water. Under the experimental conditions, a water-borne concentration of 46 mg/l was calculated to be sufficient to meet the Mg requirement of the fish fed a Mg-free diet. C1 AKVAFORSK,AGR RES COUNCIL NORWAY,INST AQUACULTURE RES,N-6600 SUNNDALSORA,NORWAY. RP SHEARER, KD (reprint author), US DEPT COMMERCE,NOAA,NATL MARINE FISHERIES SERV,UTILIZAT RES DIV,NWFC,SEATTLE,WA 98112, USA. NR 17 TC 40 Z9 42 U1 0 U2 6 PU KUGLER PUBLICATIONS BV PI LELYSTAD PA PLATINASTRAAT 33, 8211 AR LELYSTAD, NETHERLANDS SN 0920-1742 J9 FISH PHYSIOL BIOCHEM JI Fish Physiol. Biochem. PD FEB PY 1992 VL 9 IS 5-6 BP 387 EP 392 DI 10.1007/BF02274219 PG 6 WC Biochemistry & Molecular Biology; Fisheries; Physiology SC Biochemistry & Molecular Biology; Fisheries; Physiology GA HP966 UT WOS:A1992HP96600002 PM 24213815 ER PT J AU STENBAKKEN, GN STARZYK, JA AF STENBAKKEN, GN STARZYK, JA TI DIAKOPTIC AND LARGE CHANGE SENSITIVITY ANALYSIS SO IEE PROCEEDINGS-G CIRCUITS DEVICES AND SYSTEMS LA English DT Article DE NETWORKS; SENSITIVITY ID ALGORITHMS; SYSTEMS AB An approach to the analysis of large circuits based on the use of the large change sensitivity technique applied to decomposed networks is presented. As a result of this approach a simple, compact notation for the solution vector is derived. The method is applicable to nonlinear analogue networks with hierarchical decomposition simulated by inserted ideal switches. A simple illustrative example is given. C1 OHIO UNIV,DEPT ELECT & COMP ENGN,ATHENS,OH 45701. RP STENBAKKEN, GN (reprint author), NATL INST STAND & TECHNOL,DIV ELECT,GAITHERSBURG,MD 20899, USA. NR 13 TC 13 Z9 13 U1 0 U2 0 PU IEE-INST ELEC ENG PI HERTFORD PA MICHAEL FARADAY HOUSE SIX HILLS WAY STEVENAGE, HERTFORD, ENGLAND SG1 2AY SN 0956-3768 J9 IEE PROC-G PD FEB PY 1992 VL 139 IS 1 BP 114 EP 118 PG 5 WC Engineering, Electrical & Electronic SC Engineering GA HD515 UT WOS:A1992HD51500019 ER PT J AU GHATAK, AK GALLAWA, RL GOYAL, IC AF GHATAK, AK GALLAWA, RL GOYAL, IC TI ACCURATE SOLUTIONS TO SCHRODINGER-EQUATION USING MODIFIED AIRY FUNCTIONS SO IEEE JOURNAL OF QUANTUM ELECTRONICS LA English DT Letter AB A formalism that utilizes the Airy functions is applied to Schrodinger's equation for a spherically symmetric potential. We show that the computational procedure is very simple and allows us to have a very accurate description of bound-state wave functions and the corresponding eigenvalues. C1 NATL INST STAND TECHNOL,DIV ELECTROMAGNET TECHNOL,BOULDER,CO 80303. RP GHATAK, AK (reprint author), INDIAN INST TECHNOL,DEPT PHYS,NEW DELHI 110016,INDIA. NR 7 TC 18 Z9 21 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 0018-9197 J9 IEEE J QUANTUM ELECT JI IEEE J. Quantum Electron. PD FEB PY 1992 VL 28 IS 2 BP 400 EP 404 DI 10.1109/3.123265 PG 5 WC Engineering, Electrical & Electronic; Optics; Physics, Applied SC Engineering; Optics; Physics GA HC694 UT WOS:A1992HC69400002 ER PT J AU VANBRUNT, RJ STRICKLETT, KL STEINER, JP KULKARNI, SV AF VANBRUNT, RJ STRICKLETT, KL STEINER, JP KULKARNI, SV TI RECENT ADVANCES IN PARTIAL DISCHARGE MEASUREMENT CAPABILITIES AT NIST SO IEEE TRANSACTIONS ON ELECTRICAL INSULATION LA English DT Article; Proceedings Paper CT VOLTA COLLOQUIUM ON PARTIAL DISCHARGE MEASUREMENT CY SEP 04-06, 1990 CL COMO, ITALY SP POLTITECN MILANO, ASSOC ECOLES INT, MILAN SECT ID POINT-PLANE CORONA; STOCHASTIC PROPERTIES; NEGATIVE CORONA; PULSES; VOLTAGE; OXYGEN; SF6; DC AB This report describes three techniques under development at the National Institute of Standards and Technology (NIST) to measure the properties of partial discharges (PD). These measurements are useful in providing new insight into the mechanisms that influence or control PD behavior and in affording a means of locating PD activity in cables. The first is concerned with an advanced, real-time PD measurement system that allows a 'complete' characterization of the stochastic properties of PD. With this system it is possible to measure a set of conditional PD pulse amplitude and pulse-time separation distributions from which memory effects characteristic of the discharge phenomena can be quantified and interpreted. Examples of results obtained for pulsating negative corona discharges in gases are shown. The second technique allows PD location in cables using time-domain reflectometry with appropriate statistical analysis. With the third technique discussed here, simultaneous measurements are made of the optical and electrical characteristics of PD in liquid dielectrics using fast photography combined with broad-band, low-noise pulse current measurements. This method provides a detailed description of the temporal and spatial development of PD in highly nonuniform field configurations. Examples of results are shown for the case of PD in hexanes when a dc voltage is applied to a point-rod electrode gap. C1 BIDDLE INSTRUMENTS,BLUE BELL,PA. INST PLASMA RES,GANDHI SAGAR,INDIA. RP VANBRUNT, RJ (reprint author), NATL INST STAND & TECHNOL,GAITHERSBURG,MD, USA. NR 40 TC 12 Z9 12 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 0018-9367 J9 IEEE T ELECTR INSUL PD FEB PY 1992 VL 27 IS 1 BP 114 EP 129 DI 10.1109/14.123447 PG 16 WC Engineering, Electrical & Electronic SC Engineering GA HF199 UT WOS:A1992HF19900014 ER PT J AU KANDA, M HILL, DA AF KANDA, M HILL, DA TI A 3-LOOP METHOD FOR DETERMINING THE RADIATION CHARACTERISTICS OF AN ELECTRICALLY SMALL SOURCE SO IEEE TRANSACTIONS ON ELECTROMAGNETIC COMPATIBILITY LA English DT Article AB This paper proposes a method for determining the radiation characteristics of an electrically small source. The source is located at the center of three orthogonal loop antennas, each terminated with identical loads at diametrically opposite points. The electrically small source is represented by equivalent electric and magnetic dipole moments, and these dipole moments can be determined from the appropriate combinations of the loop responses. C1 UNIV COLORADO,DEPT ELECT & COMP ENGN,BOULDER,CO 80309. RP KANDA, M (reprint author), NATL INST STAND & TECHNOL,DIV ELECTROMAGNET FIELDS,FIELDS & INTERFERENCE METROL GRP,BOULDER,CO 80303, USA. NR 5 TC 23 Z9 23 U1 0 U2 0 PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017-2394 SN 0018-9375 J9 IEEE T ELECTROMAGN C JI IEEE Trans. Electromagn. Compat. PD FEB PY 1992 VL 34 IS 1 BP 1 EP 3 DI 10.1109/15.121659 PG 3 WC Engineering, Electrical & Electronic; Telecommunications SC Engineering; Telecommunications GA HC696 UT WOS:A1992HC69600001 ER PT J AU WITTMANN, RC AF WITTMANN, RC TI PROBE-CORRECTED SPHERICAL NEAR-FIELD SCANNING THEORY IN ACOUSTICS SO IEEE TRANSACTIONS ON INSTRUMENTATION AND MEASUREMENT LA English DT Article; Proceedings Paper CT 8TH ANNUAL CONF ON THE INSTRUMENTATION AND MEASUREMENT TECHNOLOGY ( IMTC/91 ) CY MAY 14-16, 1991 CL ATLANTA, GA SP IEEE, INSTRUMENTAT MEASUREMENT SOC, IEEE, ATLANTA SECTION ID ANTENNA AB Spherical near-field scanning is well known in electromagnetics. The acoustical analog is outlined here. Data are taken, with an arbitrary probe, on a sperical surface surrounding an unknown transducer. The algorithm uses these data to characterize the fields of the transducer everywhere outside the measurement sphere. The results can be corrected for probe effects if the probe's receiving pattern is known. RP WITTMANN, RC (reprint author), NATL INST STAND & TECHNOL,BOULDER,CO 80303, USA. NR 17 TC 9 Z9 9 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 0018-9456 J9 IEEE T INSTRUM MEAS JI IEEE Trans. Instrum. Meas. PD FEB PY 1992 VL 41 IS 1 BP 17 EP 21 DI 10.1109/19.126623 PG 5 WC Engineering, Electrical & Electronic; Instruments & Instrumentation SC Engineering; Instruments & Instrumentation GA HK154 UT WOS:A1992HK15400004 ER PT J AU BENNETT, HS LOWNEY, JR TOMIZAWA, M ISHIBASHI, T AF BENNETT, HS LOWNEY, JR TOMIZAWA, M ISHIBASHI, T TI EXPERIMENTALLY VERIFIED MAJORITY AND MINORITY MOBILITIES IN HEAVILY DOPED GAAS FOR DEVICE SIMULATIONS SO IEICE TRANSACTIONS ON ELECTRONICS LA English DT Article DE BORN APPROXIMATION; QUANTUM MECHANICAL PHASE SHIFTS; SCATTERING RATES; CARRIER MOBILITIES AB Low-field mobilities and velocity versus electric field relations are among the key input parameters for drift-diffusion simulations of field-effect and bipolar transistors. For example, most device simulations that treat scattering from ionized impurities contain mobilities or velocity versus field relations based on the Born approximation (BA). The BA is insensitive to the sign of the charged impurity and is especially poor for ionized impurity scattering because of the relatively strong scattering of long-wavelength carriers, which have low energies, and therefore violate the validity condition for the BA. Such carriers occur at high symmetry points in the Brillouin zone and are critical for device behavior. There has been a tendency in the past to assume that majority and minority mobilities are equal. This assumption can lead to incorrect interpretations of device data and thereby misleading design strategies based on such simulations. We have calculated the majority electron and minority hole mobilities in GaAs at 300 K for donor densities between 5 X 10(16) and 1 X 10(19) cm-3 and the majority hole and minority electron mobilities for acceptor densities between 5 X 10(16) and 1 X 10(20) cm-3. We have included all the important scattering mechanisms for GaAs: acoustic phonon, polar optic phonon, nonpolar optic phonon (holes only), piezoelectric, ionized impurity, carrier-carrier, and plasmon scattering. The ionized impurity and carrier-carrier scattering processes have been calculated with a quantum mechanical phase-shift analysis to obtain more accurate matrix elements for these two scattering mechanisms. We compare the total scattering rate for majority electrons due to ionized impurities based on exact phase shifts and on the BA used by Brooks-Herring. We also present additional data that show the differences between the exact phase-shift analyses and the BA for majority electron scattering rates as functions of carrier energy and scattering angle. These results show that the calculated low-field mobilities are in good agreement with experiment, but they 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 results are important for device modeling because of the need to have reliable values for the minority mobilities and velocity-field relations. RP BENNETT, HS (reprint author), NATL INST STAND & TECHNOL, DIV SEMICOND ELECTR, GAITHERSBURG, MD 20899 USA. NR 0 TC 0 Z9 0 U1 0 U2 1 PU IEICE-INST ELECTRONICS INFORMATION COMMUNICATIONS ENG PI TOKYO PA KIKAI-SHINKO-KAIKAN BLDG, 3-5-8, SHIBA-KOEN, MINATO-KU, TOKYO, 105-0011, JAPAN SN 0916-8524 EI 1745-1353 J9 IEICE T ELECTRON JI IEICE Trans. Electron. PD FEB PY 1992 VL E75C IS 2 BP 161 EP 171 PG 11 WC Engineering, Electrical & Electronic SC Engineering GA HG968 UT WOS:A1992HG96800007 ER PT J AU KIELY, AB LETTIERI, TR VORBURGER, TV AF KIELY, AB LETTIERI, TR VORBURGER, TV TI A MODEL OF AN OPTICAL ROUGHNESS-MEASURING INSTRUMENT SO INTERNATIONAL JOURNAL OF MACHINE TOOLS & MANUFACTURE LA English DT Article; Proceedings Paper CT 5TH INTERNATIONAL CONF ON METROLOGY AND PROPERTIES OF ENGINEERING SURFACES CY APR 10-12, 1991 CL LEICESTER, ENGLAND SP RANK TAYLOR HOBSON AB We have developed a nonlinear model of a commercial optical instrument for measuring the root-mean-square slopes of rough surfaces. The model improves upon previous ones in that it accounts for certain instrumental factors which affect the optical roughness measurements. RP KIELY, AB (reprint author), NATL INST STAND & TECHNOL,GAITHERSBURG,MD, USA. NR 0 TC 2 Z9 2 U1 0 U2 0 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD, ENGLAND OX5 1GB SN 0890-6955 J9 INT J MACH TOOL MANU JI Int. J. Mach. Tools Manuf. PD FEB-APR PY 1992 VL 32 IS 1-2 BP 33 EP 35 DI 10.1016/0890-6955(92)90057-N PG 3 WC Engineering, Manufacturing; Engineering, Mechanical SC Engineering GA GY618 UT WOS:A1992GY61800006 ER PT J AU DIZDAROGLU, M AF DIZDAROGLU, M TI MEASUREMENT OF RADIATION-INDUCED DAMAGE TO DNA AT THE MOLECULAR-LEVEL SO INTERNATIONAL JOURNAL OF RADIATION BIOLOGY LA English DT Article ID CHROMATOGRAPHY-MASS-SPECTROMETRY; RADICAL-INDUCED FORMATION; CULTURED MAMMALIAN-CELLS; LINK INVOLVING THYMINE; INDUCED BASE PRODUCTS; GAMMA-IRRADIATED DNA; ALKALI-LABILE SITE; DEOXYRIBONUCLEIC-ACID; AQUEOUS-SOLUTION; IONIZING-RADIATION RP DIZDAROGLU, M (reprint author), NATL INST STAND & TECHNOL,CHEM SCI & TECHNOL LAB,GAITHERSBURG,MD 20899, USA. NR 81 TC 51 Z9 52 U1 2 U2 2 PU TAYLOR & FRANCIS LTD PI LONDON PA ONE GUNDPOWDER SQUARE, LONDON, ENGLAND EC4A 3DE SN 0955-3002 J9 INT J RADIAT BIOL JI Int. J. Radiat. Biol. PD FEB PY 1992 VL 61 IS 2 BP 175 EP 183 DI 10.1080/09553009214550791 PG 9 WC Biology; Nuclear Science & Technology; Radiology, Nuclear Medicine & Medical Imaging SC Life Sciences & Biomedicine - Other Topics; Nuclear Science & Technology; Radiology, Nuclear Medicine & Medical Imaging GA HD276 UT WOS:A1992HD27600004 PM 1351904 ER PT J AU CARASSO, AS AF CARASSO, AS TI SPACE MARCHING DIFFERENCE-SCHEMES IN THE NONLINEAR INVERSE HEAT-CONDUCTION PROBLEM SO INVERSE PROBLEMS LA English DT Article AB For ill-posed initial value problems, step by step marching computations are unconditionally unstable, and necessarily blow-up numerically as the mesh is refined. However, for the 1D nonlinear inverse heat conduction problem, we show how to construct consistent marching schemes that blow-up much more slowly than the counterpart analytical problem. Several new space marching finite difference schemes are formulated and compared with existing schemes relative to their error amplification properties. Using the Lax-Richtmyer theory, we evaluate the L2 norms of the linearized discrete solution operators mapping the sensor data into the desired temperature and gradient histories at the inaccessible active surface. Various combinations of space and time differencing are examined, leading to 18 different algorithms. A non-dimensional parameter-OMEGA, involving the time step DELTA-t, the effective thermal diffusivity-alpha, and the distance-iota from the sensor to the active surface, is shown to provide a measure of the numerical difficulty of the inverse calculation. All 18 schemes blow-up like 10-lambda-OMEGA, where the constant-lambda depends on the particular numerical method. There are substantial differences in the lambda's however, and some new algorithms, employing forward time differences at non-adjacent mesh points, are shown to produce relatively low values of lambda. Next, using synthetic noisy data, a nonlinear reconstruction problem is considered for which OMEGA = 25. This problem simulates heat transfer in gun barrels when a shell is fired. It is shown that while most of the 18 schemes cannot recover the thermal pulses at the gun tube wall, two of the new methods provide reasonably accurate results. A tendency to underestimate peak values in fast, narrow thermal pulses, is also noted. RP CARASSO, AS (reprint author), NIST,COMP & APPL MATH LAB,GAITHERSBURG,MD 20899, USA. NR 20 TC 18 Z9 18 U1 2 U2 5 PU IOP PUBLISHING LTD PI BRISTOL PA TECHNO HOUSE, REDCLIFFE WAY, BRISTOL, ENGLAND BS1 6NX SN 0266-5611 J9 INVERSE PROBL JI Inverse Probl. PD FEB PY 1992 VL 8 IS 1 BP 25 EP 43 DI 10.1088/0266-5611/8/1/002 PG 19 WC Mathematics, Applied; Physics, Mathematical SC Mathematics; Physics GA HG674 UT WOS:A1992HG67400002 ER PT J AU BRAVERMAN, DS AF BRAVERMAN, DS TI DETERMINATION OF RARE-EARTH ELEMENTS BY LIQUID-CHROMATOGRAPHIC SEPARATION USING INDUCTIVELY COUPLED PLASMA MASS-SPECTROMETRIC DETECTION SO JOURNAL OF ANALYTICAL ATOMIC SPECTROMETRY LA English DT Article DE INDUCTIVELY COUPLED PLASMA MASS SPECTROMETRY; LIQUID CHROMATOGRAPHY; RARE EARTH ELEMENTS; COAL FLY ASH; ISOTOPE DILUTION ID GEOLOGICAL SAMPLES; LANTHANIDES; TRACERS AB High-performance liquid chromatography (HPLC) is used to separate the rare earth elements (REEs) prior to detection by inductively coupled plasma mass spectrometry (ICP-MS). The use of HPLC-ICP-MS in series combines the separation power and speed of HPLC with the sensitivity, isotopic selectivity and speed of ICP-MS. The detection limits for the REEs are in the sub-ng ml-1 range and the response is linear over four orders of magnitude. A preliminary comparison of isotope dilution and external standard results for the determination of REEs in National Institute of Standards and Technology (NIST) Standard Reference Material (SRM 1633a) Fly Ash is presented. RP BRAVERMAN, DS (reprint author), NATL INST STAND & TECHNOL,CHEM SCI & TECHNOL LAB,GAITHERSBURG,MD 20899, USA. NR 17 TC 51 Z9 52 U1 0 U2 5 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 FEB PY 1992 VL 7 IS 1 BP 43 EP 46 DI 10.1039/ja9920700043 PG 4 WC Chemistry, Analytical; Spectroscopy SC Chemistry; Spectroscopy GA HB516 UT WOS:A1992HB51600012 ER PT J AU MILDNER, DFR HAMMOUDA, B AF MILDNER, DFR HAMMOUDA, B TI THE TRANSMISSION OF CURVED NEUTRON GUIDES WITH NONPERFECT REFLECTIVITY SO JOURNAL OF APPLIED CRYSTALLOGRAPHY LA English DT Article ID MIRROR SYSTEM AB Approximate analytic expressions for determining the transmission of neutron benders which take into account reflectivity losses using the mean number of reflections agree well with computer simulation results which track the neutron trajectories directly, provided that the reflectivity is high. The exact calculation which can be performed using exponential integral functions for any value of the reflectivity is presented. Ray-tracing techniques for determining the transmission and number of reflections for non-perfect reflectivity can therefore be replaced by direct calculation. RP MILDNER, DFR (reprint author), NIST,GAITHERSBURG,MD 20899, USA. NR 12 TC 4 Z9 4 U1 0 U2 1 PU MUNKSGAARD INT PUBL LTD PI COPENHAGEN PA 35 NORRE SOGADE, PO BOX 2148, DK-1016 COPENHAGEN, DENMARK SN 0021-8898 J9 J APPL CRYSTALLOGR JI J. Appl. Crystallogr. PD FEB 1 PY 1992 VL 25 BP 39 EP 45 DI 10.1107/S0021889891009615 PN 1 PG 7 WC Chemistry, Multidisciplinary; Crystallography SC Chemistry; Crystallography GA HD733 UT WOS:A1992HD73300007 ER PT J AU LOWNEY, JR SEILER, DG LITTLER, CL YOON, IT AF LOWNEY, JR SEILER, DG LITTLER, CL YOON, IT TI INTRINSIC CARRIER CONCENTRATION OF NARROW-GAP MERCURY CADMIUM TELLURIDE BASED ON THE NONLINEAR TEMPERATURE-DEPENDENCE OF THE BAND-GAP SO JOURNAL OF APPLIED PHYSICS LA English DT Article ID ENERGY-GAP; HG1-XCDXTE AB The intrinsic carrier concentrations of narrow-gap Hg1-xCdxTe alloys have been calculated as a function of temperature between 0 and 300 K for x values between 0.17 and 0.30. The new and more accurate relation for the temperature dependence of the energy gap, which is based on two-photon magnetoabsorption data, is used. This relation is further supported here by additional one-photon magnetoabsorption measurements for x = 0.20 and 0.23, which were made with a CO2 laser. In this range of composition and temperature, the energy gap of mercury cadmium telluride is small, and very accurate values for the gap are needed to obtain reliable values for the intrinsic carrier density. Kane's k'p theory is used to account for the conduction-band nonparabolicity. Large percentage differences occur between our new calculations and previously calculated values for n(i) at low temperatures. A nonlinear least-squares fit was made to the results of our calculations for ease of use. The implications of these results for Hg1-xCdxTe materials characterization and device operations are discussed. C1 UNIV N TEXAS,DEPT PHYS,DENTON,TX 76203. RP LOWNEY, JR (reprint author), NATL INST STAND & TECHNOL,DIV SEMICOND ELECTR,GAITHERSBURG,MD 20899, USA. NR 13 TC 41 Z9 42 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 FEB 1 PY 1992 VL 71 IS 3 BP 1253 EP 1258 DI 10.1063/1.351371 PG 6 WC Physics, Applied SC Physics GA HC908 UT WOS:A1992HC90800027 ER PT J AU KIM, YJ BOATMAN, JF AF KIM, YJ BOATMAN, JF TI THE COLLECTION EFFICIENCY OF A MODIFIED MOHNEN SLOTTED-ROD CLOUD-WATER COLLECTOR IN SUMMER CLOUDS SO JOURNAL OF ATMOSPHERIC AND OCEANIC TECHNOLOGY LA English DT Article AB A modified Mohnen slotted-rod collector was used to collect cloud-water samples in summer clouds over the northeastern United States. Cloud-droplet-size distributions were measured with a forward-scattering spectrometer probe (FSSP) mounted on the National Oceanic and Atmospheric Administration (NOAA) King Air research aircraft. Cloud-droplet-volume distributions and liquid water content were determined for each cloud-water sample through analyses of the FSSP data. The theoretical collection efficiency of the slotted-rod collector was calculated as a function of droplet size for flight conditions encountered during each cloud-water sampling. The mass ratio was then calculated for each cloud sample by ratioing the actual collected water mass to the maximum possible collectable water mass. Mass-ratio values higher than unity were obtained having an average of 1.40 +/- 0.27. This could be due to an underestimation of the liquid water content by the FSSP or to the collection of large hydrometeors by the slotted rod. The modified Mohnen slotted rod collected fast representative cloud-water samples in sufficient quantities for chemical analysis of the sampled cloud water. RP KIM, YJ (reprint author), NOAA,ENVIRONM RES LABS,AIR RESOURCES LAB,AEROSOL RES SECT,325 BROADWAY,BOULDER,CO 80303, USA. NR 0 TC 9 Z9 9 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 FEB PY 1992 VL 9 IS 1 BP 35 EP 41 DI 10.1175/1520-0426(1992)009<0035:TCEOAM>2.0.CO;2 PG 7 WC Engineering, Ocean; Meteorology & Atmospheric Sciences SC Engineering; Meteorology & Atmospheric Sciences GA HD466 UT WOS:A1992HD46600004 ER PT J AU PINE, AS LOONEY, JP AF PINE, AS LOONEY, JP TI SELF-BROADENING AND LINE MIXING IN HCN Q-BRANCHES SO JOURNAL OF CHEMICAL PHYSICS LA English DT Article ID ROTATIONALLY INELASTIC RATES; RAMAN-Q-BRANCH; SCALING THEORETICAL-ANALYSIS; FOURIER-TRANSFORM SPECTRA; TUNABLE-DIODE-LASER; DOUBLE-RESONANCE; ENERGY-TRANSFER; DIPOLE-MOMENT; GROUND-STATE; FAR WINGS AB Q-branch spectra of the nu(1) + nu(2) (4004 cm-1) and nu(2) + nu(3) (2806 cm-1) combination bands and the nu(1) - nu(2) (2599 cm-1) difference hot band of HCN have been recorded at pressures from 0.13 to 53.3 kPa (1 to 400 Torr) using a tunable difference-frequency laser. The self-broadening coefficients are the same for all three bands involving the nu(2) PI-bending mode and are within experimental error of those reported previously for other SIGMA and PI-vibrational bands. The J dependence of the self-broadening coefficients exhibits a maximum near the peak of the Boltzmann population distribution, and is well described by semiclassical line-broadening theory incorporating known measured or ab initio dipole and quadrupole moments and polarizabilities, and classical trajectories using an isotropic Lennard-Jones short-range potential. Line mixing is evident in the strongly overlapped, higher pressure Q-branch profiles from the nonadditive Lorentzian superposition of the component transitions. However, line coupling is moderated by the f --> e collisional cross relaxation in the l-doubled PI-bending vibration. The inelastic rotational collision rates required to fit the spectral line-mixing profiles are poorly represented by empirical energy-gap fitting laws for both R --> T and R --> R energy transfer. An effective R --> T energy-corrected-sudden (ECS) scaling law yields a satisfactory and consistent fit to the Q-branch profiles of all three bands for the pressure range studied. C1 NATL INST STAND & TECHNOL,DIV THERMOPHYS,GAITHERSBURG,MD 20899. RP PINE, AS (reprint author), NATL INST STAND & TECHNOL,DIV MOLEC PHYS,GAITHERSBURG,MD 20899, USA. NR 84 TC 34 Z9 34 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 FEB 1 PY 1992 VL 96 IS 3 BP 1704 EP 1714 DI 10.1063/1.462125 PG 11 WC Chemistry, Physical; Physics, Atomic, Molecular & Chemical SC Chemistry; Physics GA HC610 UT WOS:A1992HC61000005 ER PT J AU LYNCH, JJ RAINWATER, JC VANPOOLEN, LJ SMITH, DH AF LYNCH, JJ RAINWATER, JC VANPOOLEN, LJ SMITH, DH TI PREDICTION OF FLUID PHASE-EQUILIBRIUM OF TERNARY MIXTURES IN THE CRITICAL REGION AND THE MODIFIED LEUNG-GRIFFITHS THEORY SO JOURNAL OF CHEMICAL PHYSICS LA English DT Article ID VAPOR-LIQUID-EQUILIBRIUM; CRITICAL-POINTS; SYSTEMS AB The modified Leung-Griffiths theory of vapor-liquid equilibrium (VLE) is generalized to the case of three components. The principle of "corresponding states" is reconsidered along with certain functions of "field variables" within the model. The mathematical form of the coexistence boundary in terms of the field variables remains practically unchanged and conforms to modern scaling theory. The new model essentially predicts ternary fluid mixture phase boundaries in the critical region from previous vapor-liquid equilibrium data correlations of the three binary fluid mixture limits. Predicted saturation isotherms of the ethane + n-butane + n-pentane and ethane + n-butane + n-heptane mixtures are compared with experimental ternary VLE data in the literature. C1 NATL INST STANDARDS & TECHNOL,DIV THERMOPHYS,BOULDER,CO 80303. RP LYNCH, JJ (reprint author), US DOE,MORGANTOWN ENERGY TECHNOL CTR,MORGANTOWN,WV 26507, USA. NR 29 TC 4 Z9 4 U1 0 U2 0 PU AMER INST PHYSICS PI WOODBURY PA CIRCULATION FULFILLMENT DIV, 500 SUNNYSIDE BLVD, WOODBURY, NY 11797-2999 SN 0021-9606 J9 J CHEM PHYS JI J. Chem. Phys. PD FEB 1 PY 1992 VL 96 IS 3 BP 2253 EP 2260 DI 10.1063/1.462075 PG 8 WC Chemistry, Physical; Physics, Atomic, Molecular & Chemical SC Chemistry; Physics GA HC610 UT WOS:A1992HC61000064 ER PT J AU RICHTER, LJ BUNTIN, SA KING, DS CAVANAGH, RR AF RICHTER, LJ BUNTIN, SA KING, DS CAVANAGH, RR TI STATE-RESOLVED STUDIES OF THE LASER-INDUCED DESORPTION OF NO FROM SI(111) 7X7 - LOW COVERAGE RESULTS SO JOURNAL OF CHEMICAL PHYSICS LA English DT Article ID INDUCED THERMAL-DESORPTION; DRIVEN SURFACE-REACTIONS; ELECTRONIC-TRANSITIONS; SEMICONDUCTOR SURFACES; PHOTOINDUCED REACTIONS; NITRIC-OXIDE; RECOMBINATION; SILICON; PHOTODESORPTION; PHOTOEMISSION AB The results of a quantum-state-resolved study of the laser-induced desorption (LID) of NO from Si(111) 7 x 7 at a surface temperature of 100 K are reported. All aspects of the LID are found to be sensitive to the initial coverage. The coverage dependence indicates that there are two desorption mechanisms, one operative at low coverages that is quenched with increasing NO exposure, and one operative at high coverage. This report characterizes the low coverage channel. Most of the energy in the desorbed NO occurs as vibration and translation, with the rotations substantially cooler. The desorption is selective for production of the ground spin-orbit state. The energy partitioning shows strikingly little change as the desorption-laser wavelength was varied from 1907 to 355 nm. This, coupled with a quantitative study of the yield over the same photon energy range and selective coadsorption experiments, establishes that the desorption is specifically due to an interaction involving photogenerated holes in the rest-atom localized, intrinsic surface state of the 7 x 7 reconstructed surface. It is suggested that the surface state hole drives the desorption by neutralization of a NO-delta adsorbate. RP RICHTER, LJ (reprint author), NATL INST STAND & TECHNOL,GAITHERSBURG,MD 20899, USA. RI Richter, Lee/N-7730-2016 OI Richter, Lee/0000-0002-9433-3724 NR 85 TC 38 Z9 38 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 FEB 1 PY 1992 VL 96 IS 3 BP 2324 EP 2338 DI 10.1063/1.462029 PG 15 WC Chemistry, Physical; Physics, Atomic, Molecular & Chemical SC Chemistry; Physics GA HC610 UT WOS:A1992HC61000072 ER PT J AU MANABE, S SPELMAN, MJ STOUFFER, RJ AF MANABE, S SPELMAN, MJ STOUFFER, RJ TI TRANSIENT RESPONSES OF A COUPLED OCEAN ATMOSPHERE MODEL TO GRADUAL CHANGES OF ATMOSPHERIC CO2 .2. SEASONAL RESPONSE SO JOURNAL OF CLIMATE LA English DT Article ID GLOBAL CLIMATE MODEL; CARBON-DIOXIDE; SUMMER DRYNESS; SOIL WETNESS; SENSITIVITY; INCREASE AB This study investigates the seasonal variation of the transient response of a coupled ocean-atmosphere model to a gradual increase (or decrease) of atmospheric carbon dioxide. The model is a general circulation model of the coupled atmosphere-ocean-land surface system with a global computational domain, smoothed geography, and seasonal variation of insolation. It was found that the increase of surface air temperature in response to a gradual increase of atmospheric carbon dioxide is at a maximum over the Arctic Ocean and its surroundings in the late fall and winter. On the other hand, the Arctic warming is at a minimum in summer. In sharp contrast to the situation in the Arctic Ocean, the increase of surface air temperature and its seasonal variation in the circumpolar ocean of the Southern Hemisphere are very small because of the vertical mixing of heat over a deep water column. In response to the gradual increase of atmospheric carbon dioxide, soil moisture is reduced during the June-July-August period over most of the continents in the Northern Hemisphere with the notable exception of the Indian subcontinent, where it increases. The summer reduction of soil moisture in the Northern Hemisphere is relatively large over the region stretching from the northern United States to western Canada, eastern China, southern Europe, Scandinavia, and most of the Russian Republic. During the December-January-February period, soil moisture increases in middle and high latitudes of the Northern Hemisphere. The increase is relatively large over the western portion of the Russian Republic and the central portion of Canada. On the other hand, it is reduced in the subtropics, particularly over Southeast Asia and Mexico. Because of the reduction (or delay) in the warming of the oceanic surface due to the thermal inertia of the oceans, the increase of the moisture supply from the oceans to continents is reduced, thereby contributing to the reduction of both soil moisture and runoff over the continents in middle and high latitudes of the Northern Hemisphere. This mechanism enhances the summer reduction of soil moisture and lessens its increase during winter in these latitudes. The changes in surface air temperature and soil moisture in response to the gradual reduction of atmospheric CO2 are opposite in sign but have seasonal and geographical distributions that are broadly similar to the response to the gradual CO2 increase described above. RP MANABE, S (reprint author), PRINCETON UNIV,NOAA,GEOPHYS FLUID DYNAM LAB,FORRESTAL CAMPUS,US ROUTE 1,POB 308,PRINCETON,NJ 08542, USA. NR 31 TC 258 Z9 263 U1 0 U2 16 PU AMER METEOROLOGICAL SOC PI BOSTON PA 45 BEACON ST, BOSTON, MA 02108-3693 SN 0894-8755 J9 J CLIMATE JI J. Clim. PD FEB PY 1992 VL 5 IS 2 BP 105 EP 126 DI 10.1175/1520-0442(1992)005<0105:TROACO>2.0.CO;2 PG 22 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA HP485 UT WOS:A1992HP48500001 ER PT J AU AHN, BH KAMIDE, Y KROEHL, HW GORNEY, DJ AF AHN, BH KAMIDE, Y KROEHL, HW GORNEY, DJ TI CROSS-POLAR CAP POTENTIAL DIFFERENCE, AURORAL ELECTROJET INDEXES, AND SOLAR-WIND PARAMETERS SO JOURNAL OF GEOPHYSICAL RESEARCH-SPACE PHYSICS LA English DT Article; Proceedings Paper CT WORKSHOP ON PLASMASPHERE REFILLING CY OCT 15-16, 1990 CL UNIV ALABAMA, HUNTSVILLE, AL HO UNIV ALABAMA ID INTERPLANETARY MAGNETIC-FIELD; INCOHERENT-SCATTER FACILITY; ENERGY COUPLING FUNCTION; BIRKELAND CURRENTS; CONVECTION; IONOSPHERE; DEPENDENCE; MAGNETOPAUSE; RECONNECTION; INDEXES AB The cross-polar cap potential difference PHI (KRM) is estimated from ground magnetic perturbation data through the magnetometer inversion method of Kamide, Richmond, and Matsushita (KRM), combined with an "empirical" ionospheric conductance distribution estimated from the DMSP X ray image data. A significant correlation is found between PHI (KRM) and the AE(12) index; PHI (KRM, in kilovolts) = 36 + 0.082 AE(12, in nanoteslas) with the correlation coefficient being 0.80, PHI (KRM) is then compared with the potential difference estimated from a more direct method of the satellite electric field measurements [Weimer et al., 1990] and also with PHI (IMF) based on solar wind parameters [Reiff and Luhmann, 1986]. PHI(IMF) is found to be linearly correlated with PHI (KRM), as PHI (IMF) = 29.8 + 0.999 PHI (KRM), with the highest correlation obtained for a 40-min lag in the interplanetary magnetic field (IMF). Note that PHI (IMF) is systematically larger than PHI (KRM) by 30 kV, suggesting the possibility that the theoretical method overestimates the cross-polar cap potential difference. During steady southward IMF periods where steady PHI (IMF) variations are expected, significant fluctuations in calculated PHI (KRM) values are obtained. Since the decrease in PHI (KRM) is closely associated with enhancements in auroral particle precipitation during these periods, a highly correlative relation between PHI (IMF) and PHI (KRM) cannot be deduced unless the phases of substoms are taken into account. The overall high correlation between them, however, supports the view expressed by Wolf et al. [1986] that directly driven processes are more important than unloading processes during disturbed periods. C1 AEROSPACE CORP,SPACE SCI LAB,LOS ANGELES,CA 90009. KYOTO SANGYO UNIV,FAC SCI,KYOTO 603,JAPAN. NOAA,NATL GEOPHYS DATA CTR,BOULDER,CO 80303. UNIV COLORADO,NOAA,COOPERAT INST RES ENVIRONM SCI,BOULDER,CO 80309. RP AHN, BH (reprint author), KYUNGPOOK NATL UNIV,DEPT EARTH SCI,TAEGU,SOUTH KOREA. NR 41 TC 37 Z9 37 U1 0 U2 2 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 SN 0148-0227 J9 J GEOPHYS RES JI J. Geophys. Res-Space Phys. PD FEB 1 PY 1992 VL 97 IS A2 BP 1345 EP 1352 DI 10.1029/91JA02432 PG 8 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA HB870 UT WOS:A1992HB87000024 ER PT J AU KAHLER, SW HUNDHAUSEN, AJ AF KAHLER, SW HUNDHAUSEN, AJ TI THE MAGNETIC TOPOLOGY OF SOLAR CORONAL STRUCTURES FOLLOWING MASS EJECTIONS SO JOURNAL OF GEOPHYSICAL RESEARCH-SPACE PHYSICS LA English DT Article ID TRANSIENT; PROMINENCE; RECONNECTION; DISTURBANCES; GEOMETRY; STREAMER; SKYLAB; EVENTS; CLOUDS; RADIO AB The bright radial structures observed in the solar corona for 1-2 days following a coronal mass ejection (CME) have traditionally been interpreted as unidirectional magnetic fields, commonly known as "legs," at the sides of the ejections. We examine in detail the bright structures following 16 CMEs observed with the coronagraph on the Solar Maximum Mission (SMM) spacecraft and find that these structures can form anywhere within the lateral span of a CME, not only at the sides. We suggest that a more plausible interpretation is that the bright radial structures are the tops of coronal streamers containing magnetic neutral sheets across which the magnetic fields reverse direction. The observational support for this view is that: (1) the bright features left behind at CME sides, when a CME has left the field of view of this instrument, last < 10 hours; (2) some bright radial structures form at the sites of preexisting streamers; (3) some such structures have the broad bascs characteristic of helmet streamers; and (4) in several cases, narrow radial structures form over H a prominences. A reexamination of the structures observed in the Skylab era, including the well-studied CME of August 10, 1973, reveals that they are also consistent with the streamer interpretation. This interpretation avoids several difficulties encountered with the "leg" interpretation: (1) the systematic brightening of legs-1 day after the CME; (2) the origin of the energetic electrons characteristic of stationary type IV bursts if they are associated with high-density, unidirectional-field structures unfavorable for particle acceleration; and (3) the lack of strong evidence of magnetic reconnection in the coronograph data following CMEs. C1 NATL CTR ATMOSPHER RES,HIGH ALTITUDE OBSERV,BOULDER,CO 80307. NOAA,SPACE ENVIRONM LAB,BOULDER,CO 80303. NR 42 TC 55 Z9 55 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 FEB 1 PY 1992 VL 97 IS A2 BP 1619 EP 1631 DI 10.1029/91JA02402 PG 13 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA HB870 UT WOS:A1992HB87000048 ER PT J AU SEO, DJ SMITH, JA AF SEO, DJ SMITH, JA TI RADAR-BASED SHORT-TERM RAINFALL PREDICTION SO JOURNAL OF HYDROLOGY LA English DT Article ID STATION PRECIPITATION MODEL AB A radar-based short-term rainfall prediction model is formulated and evaluated. The prediction lead time of interest is approximately 1 h. The model is composed of a physically based component and a statistical component. The physically based part performs mass balancing of mean vertically integrated liquid water content (VIL) under convective warm rainfall situations, using full-volume scan radar data, surface meteorological observations and upper air data. The statistical part performs prediction of residual VIL. Conversion of predicted VIL to rainfall is made using empirical relationships among VIL, rainwater content at cloud bottom, and echo-top height, which is assumed to remain constant over the prediction lead time. To evaluate the model, a comparison is made against advection-based nowcasting using radar data from the National Weather Service Radar Data Processor, version II (RADAP II) system at Oklahoma City. Results from parameter estimation runs show that inclusion of the simple physical and statistical dynamics has potential in improving advection-based nowcasting under convective situations. An apparent bias in mean rainfall prediction, however, suggests room for improvement. Issues concerning possible improvements are described, and future research directions are discussed. C1 PRINCETON UNIV,DEPT CIVIL ENGN & OPERAT RES,PRINCETON,NJ 08544. NOAA,NATL WEATHER SERV,HYDROL RES LAB,SILVER SPRING,MD 20910. NR 30 TC 28 Z9 28 U1 0 U2 0 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0022-1694 J9 J HYDROL JI J. Hydrol. PD FEB PY 1992 VL 131 IS 1-4 BP 341 EP 367 DI 10.1016/0022-1694(92)90225-K PG 27 WC Engineering, Civil; Geosciences, Multidisciplinary; Water Resources SC Engineering; Geology; Water Resources GA HJ047 UT WOS:A1992HJ04700015 ER PT J AU LUMIA, R JAMSHIDI, MO AF LUMIA, R JAMSHIDI, MO TI ROBOTICS AND INTELLIGENT SYSTEMS RESEARCH AT NIST SO JOURNAL OF INTELLIGENT & ROBOTIC SYSTEMS LA English DT Editorial Material C1 UNIV NEW MEXICO,DEPT ELECT & COMP ENGN,CAD LAB SYST & ROBOT,ALBUQUERQUE,NM 87131. RP LUMIA, R (reprint author), NATL INST STAND & TECHNOL,METROL BLDG,ROOM B-124,GAITHERSBURG,MD 20899, USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU KLUWER ACADEMIC PUBL PI DORDRECHT PA SPUIBOULEVARD 50, PO BOX 17, 3300 AA DORDRECHT, NETHERLANDS SN 0921-0296 J9 J INTELL ROBOT SYST JI J. Intell. Robot. Syst. PD FEB PY 1992 VL 5 IS 1 BP 3 EP 4 DI 10.1007/BF00357126 PG 2 WC Computer Science, Artificial Intelligence; Robotics SC Computer Science; Robotics GA HE741 UT WOS:A1992HE74100001 ER PT J AU FIALA, J WAVERING, AJ AF FIALA, J WAVERING, AJ TI EXPERIMENTAL EVALUATION OF CARTESIAN STIFFNESS CONTROL ON A 7 DEGREE-OF-FREEDOM ROBOT ARM SO JOURNAL OF INTELLIGENT & ROBOTIC SYSTEMS LA English DT Article DE STIFFNESS CONTROL; CARTESIAN CONTROL; ROBOT CONTROL ALGORITHMS; CONTROL SYSTEM ARCHITECTURES ID MANIPULATORS AB The programmability of Cartesian stiffness in Cartesian servo control algorithms that do not use explicit force feedback is examined. A number of Cartesian algorithms are implemented and evaluated on a commercial seven degree-of-freedom robot arm, using the NASREM robot control system testbed. It is found that Cartesian servo algorithms which use the transpose of the Jacobian and model-based gravity compensation, provide easy programmability and accurate reproduction of stiffnesses over a wide range. When dynamic behavior is a consideration, dynamic damping control, augmented to include a parameterization of the manipulator self-motion, provides superior performance and programmability. RP FIALA, J (reprint author), NATL INST STAND & TECHNOL,DIV ROBOT SYST,GAITHERSBURG,MD 20899, USA. NR 25 TC 1 Z9 2 U1 0 U2 0 PU KLUWER ACADEMIC PUBL PI DORDRECHT PA SPUIBOULEVARD 50, PO BOX 17, 3300 AA DORDRECHT, NETHERLANDS SN 0921-0296 J9 J INTELL ROBOT SYST JI J. Intell. Robot. Syst. PD FEB PY 1992 VL 5 IS 1 BP 5 EP 24 DI 10.1007/BF00357127 PG 20 WC Computer Science, Artificial Intelligence; Robotics SC Computer Science; Robotics GA HE741 UT WOS:A1992HE74100002 ER PT J AU ROBERTS, K NASHMAN, M AF ROBERTS, K NASHMAN, M TI REAL-TIME MODEL-BASED TRACKING COMBINING SPATIAL AND TEMPORAL FEATURES SO JOURNAL OF INTELLIGENT & ROBOTIC SYSTEMS LA English DT Article DE FEATURE TRACKING; MODEL-BASED TRACKING; MODEL-BASED VISION; REAL-TIME VISION ID MOTION AB This paper describes a method for tracking moving image features by combining spatial and temporal edge information with model-based feature information. The algorithm updates the two-dimensional position of object features by correlating predicted model features with current image data. The results of the correlation process are used to compute an updated model. The algorithm makes use of a high temporal sampling rate with respect to spatial changes of the image features and operates in a real-time multi-processing environment. Preliminary results demonstrate successful tracking for image feature velocities between 1.1 and 4.5 pixels every image frame. RP ROBERTS, K (reprint author), NATL INST STAND & TECHNOL,DIV ROBOT SYST,GAITHERSBURG,MD 20899, USA. NR 23 TC 1 Z9 1 U1 9 U2 10 PU KLUWER ACADEMIC PUBL PI DORDRECHT PA SPUIBOULEVARD 50, PO BOX 17, 3300 AA DORDRECHT, NETHERLANDS SN 0921-0296 J9 J INTELL ROBOT SYST JI J. Intell. Robot. Syst. PD FEB PY 1992 VL 5 IS 1 BP 25 EP 38 DI 10.1007/BF00357128 PG 14 WC Computer Science, Artificial Intelligence; Robotics SC Computer Science; Robotics GA HE741 UT WOS:A1992HE74100003 ER PT J AU KELMAR, L LUMIA, R AF KELMAR, L LUMIA, R TI SENSORY INTERACTIVE ROBOT TRAJECTORY CONTROL USING A REAL-TIME WORLD MODEL SO JOURNAL OF INTELLIGENT & ROBOTIC SYSTEMS LA English DT Article DE ROBOTICS; IMAGE PROCESSING; REAL-TIME CONTROL; SPACE APPLICATIONS; CONTROL SYSTEMS; HIERARCHICAL CONTROL; TELEROBOTICS AB A major consideration in the design of sensory interactive trajectory generation software for a Flight Telerobotic Servicer (FTS) is the availability and maintenance of a current model of the manipulator's world. The NASA/NBS Standard Reference Model for Telerobot Control System Architecture (NASREM), which has been adopted by NASA for control of the FTS, provides a logical computing architecture for telerobotics. It defines a hierarchical control system in which complex tasks are decomposed into progressively simpler subtasks, or objectives. It contains a hierarchy of world modeling modules which maintain the system's internal model of the manipulator and its world by continuosly updating the model based upon sensory data. Each world modeling module contains support processes or funtions which simultaneously and asynchronously support sensory processing and task decomposition. This paper discusses the role of world modeling in support of trajectory generation and execution. For sensory interactive robot motion control, the world modeling modules must operate rapidly so that the model of the world remains in registration with the real world. This paper discusses the world modeling modules of a hierarchical control system which facilitate sensory interactive trajectories by decoupling and supporting the sensory and manipulator planning processes. We define the types of information which should be included in the interfaces to the modules, as well as the modules' structure and function. Finally, we discuss the real-time implementation and experimental results of a particular sensory interactive algorithm performed in our laboratory. C1 NATL INST STAND & TECHNOL,DIV ROBOT SYST,GAITHERSBURG,MD 20899. RP KELMAR, L (reprint author), UNITED PARCEL SERV,DANBURY,CT, USA. NR 7 TC 0 Z9 0 U1 0 U2 1 PU KLUWER ACADEMIC PUBL PI DORDRECHT PA SPUIBOULEVARD 50, PO BOX 17, 3300 AA DORDRECHT, NETHERLANDS SN 0921-0296 J9 J INTELL ROBOT SYST JI J. Intell. Robot. Syst. PD FEB PY 1992 VL 5 IS 1 BP 39 EP 47 DI 10.1007/BF00357129 PG 9 WC Computer Science, Artificial Intelligence; Robotics SC Computer Science; Robotics GA HE741 UT WOS:A1992HE74100004 ER PT J AU TARNOFF, N JACOFF, A LUMIA, R AF TARNOFF, N JACOFF, A LUMIA, R TI GRAPHICAL SIMULATION FOR SENSOR BASED ROBOT PROGRAMMING SO JOURNAL OF INTELLIGENT & ROBOTIC SYSTEMS LA English DT Article DE OFF-LINE PROGRAMMING; ROBOT PROGRAMMING; SIMULATION; COMPUTER GRAPHICS; SENSOR PROGRAMMING; SENSOR MODELING; ROBOTICS; WORLD MODELING; CALIBRATION AB The programming of robots is slowly evolving from traditional teach pendant method to graphical Off-Line Programming (OLP) methods. Graphical simulation tools, such as OLP, are very useful for developing and testing robot programs before they are run on real industrial equipment. OLP systems are also used to develop task level programs. Traditional OLP systems, however, suffer from the limitations of using only position control which does not account for inherent robot inaccuracies and dynamic environments. This paper describes our work on improving and supplementing traditional position control programming methods. A baseline OLP system was implemented at NIST's Automated Manufacturing Research Facility (AMRF). Experience gained in implementing this system showed that an effective OLP system must accurately simulate the real world and must support sensor programming to compensate for real-world changes that cannot be simulated. The developed OLP geometric world model is calibrated using robot mounted ultrasound ranging sensor. The measurement capability produces a baseline geometric model of relatively good static accuracy for off-line programming. The graphical environment must also provide representations of sensor features. For this specific application, force is simulated in order to include force based commands in our robot programs. These sensor based programs are able to run reliably and safely in an unpredictable industrial environment. The last portion of this paper extends OLP and describes the functionality of a complete system for programming complex robot tasks. RP TARNOFF, N (reprint author), NATL INST STAND & TECHNOL,DIV ROBOT SYST,GAITHERSBURG,MD 20899, USA. NR 18 TC 2 Z9 2 U1 1 U2 3 PU KLUWER ACADEMIC PUBL PI DORDRECHT PA SPUIBOULEVARD 50, PO BOX 17, 3300 AA DORDRECHT, NETHERLANDS SN 0921-0296 J9 J INTELL ROBOT SYST JI J. Intell. Robot. Syst. PD FEB PY 1992 VL 5 IS 1 BP 49 EP 62 DI 10.1007/BF00357130 PG 14 WC Computer Science, Artificial Intelligence; Robotics SC Computer Science; Robotics GA HE741 UT WOS:A1992HE74100005 ER PT J AU SZABO, S SCOTT, HA MURPHY, KN LEGOWIK, SA BOSTELMAN, RV AF SZABO, S SCOTT, HA MURPHY, KN LEGOWIK, SA BOSTELMAN, RV TI HIGH-LEVEL MOBILITY CONTROLLER FOR A REMOTELY OPERATED UNMANNED LAND VEHICLE SO JOURNAL OF INTELLIGENT & ROBOTIC SYSTEMS LA English DT Article DE CONTROL SYSTEMS; HIERARCHICAL CONTROL; MOBILE ROBOTS; ROBOTIC VEHICLES; SYSTEMS ARCHITECTURES; UNMANNED LAND VEHICLES AB The U.S. Army Laboratory Command, as part of the Department of Defense Robotics Testbed Program, is developing a testbed for cooperative, real-time control of unmanned land vehicles. The program entails the development and integration of many elements which allow the vehicles to perform both autonomous and teleoperated functions. The National Institute of Standards and Technology (NIST) is supporting this program by developing the vehicle control system using the Real-time Control System (RCS) architecture. RCS is a hierarchical, sensory-based control system, initially developed for the control of industrial robots and automated manufacturing systems. NIST is developing the portions of RCS that control all vehicle mobility functions, coordinate the operations of the other subsystems on the vehicle, and communicate between the vehicle and the remote operator control station. This paper reviews the overall control system architecture, the design and implementation of the mobility and communication functions, and results from recent testing. RP SZABO, S (reprint author), NATL INST STAND & TECHNOL,DIV ROBOT SYST,SYST INTEGRAT GRP,GAITHERSBURG,MD 20899, USA. NR 9 TC 5 Z9 5 U1 1 U2 2 PU KLUWER ACADEMIC PUBL PI DORDRECHT PA SPUIBOULEVARD 50, PO BOX 17, 3300 AA DORDRECHT, NETHERLANDS SN 0921-0296 J9 J INTELL ROBOT SYST JI J. Intell. Robot. Syst. PD FEB PY 1992 VL 5 IS 1 BP 63 EP 77 DI 10.1007/BF00357131 PG 15 WC Computer Science, Artificial Intelligence; Robotics SC Computer Science; Robotics GA HE741 UT WOS:A1992HE74100006 ER PT J AU HUANG, HM HORST, J QUINTERO, R AF HUANG, HM HORST, J QUINTERO, R TI A MOTION CONTROL ALGORITHM FOR A CONTINUOUS MINING MACHINE BASED ON A HIERARCHICAL REAL-TIME CONTROL-SYSTEM DESIGN METHODOLOGY SO JOURNAL OF INTELLIGENT & ROBOTIC SYSTEMS LA English DT Article DE CONTINUOUS MINING MACHINE; CONTROL; ERROR ANALYSIS; HIERARCHY; PLAN; REAL-TIME; TASK; TASK DECOMPOSITION AB The drive toward increased safety for coal miners has led to the development of computer-assisted methods of underground coal mining. The development of control architectures for the control of the movement of continuous mining machines (tramming control) is an important part of this overall effort. The tramming control algorithm design described is in concert with hierarchical architecture design principles developed at National Institute of Standards and Technology (NIST), referred to as the Real-time Control Systems (RCS) methodology. The algorithm design allow for the control of both cutting and free-space movement by a continuous mining machine and allows for a high degree of human operator interaction. RP HUANG, HM (reprint author), NATL INST STAND & TECHNOL,DIV ROBOT SYST,GAITHERSBURG,MD 20899, USA. NR 16 TC 0 Z9 0 U1 0 U2 0 PU KLUWER ACADEMIC PUBL PI DORDRECHT PA SPUIBOULEVARD 50, PO BOX 17, 3300 AA DORDRECHT, NETHERLANDS SN 0921-0296 J9 J INTELL ROBOT SYST JI J. Intell. Robot. Syst. PD FEB PY 1992 VL 5 IS 1 BP 79 EP 99 DI 10.1007/BF00357132 PG 21 WC Computer Science, Artificial Intelligence; Robotics SC Computer Science; Robotics GA HE741 UT WOS:A1992HE74100007 ER PT J AU PARDAVIHORVATH, M OTI, J VERTESY, G BENNETT, LH SWARTZENDRUBER, LJ AF PARDAVIHORVATH, M OTI, J VERTESY, G BENNETT, LH SWARTZENDRUBER, LJ TI A PREISACH MODEL STUDY OF DEMAGNETIZED STATES SO JOURNAL OF MAGNETISM AND MAGNETIC MATERIALS LA English DT Article ID VECTOR MOVING MODEL AB The question of the existence of a unique demagnetized state arose when several M = 0 magnetic states at H = 0 have been observed for epitaxial garnet films having simple stripe domain structures. The Preisach model of the magnetic hysteresis is capable of describing different demagnetizing processes. A recent vector moving model of the hysteresis properties of particulate magnetic materials predicts that, depending on the demagnetizing process, the demagnetized states are different. Measurements of the initial magnetization process after ac and dc demagnetization of particulate recording media have been performed and compared to the predictions of the vector moving model. C1 HUNGARIAN ACAD SCI, CENT RES INST PHYS, H-1525 BUDAPEST, HUNGARY. NBS, GAITHERSBURG, MD 20899 USA. NATL INST STANDARDS & TECHNOL, BOULDER, CO USA. RP PARDAVIHORVATH, M (reprint author), GEORGE WASHINGTON UNIV, WASHINGTON, DC 20052 USA. RI Vertesy, Gabor/A-5863-2011 NR 5 TC 11 Z9 12 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 FEB PY 1992 VL 104 BP 313 EP 314 DI 10.1016/0304-8853(92)90812-3 PN 1 PG 2 WC Materials Science, Multidisciplinary; Physics, Condensed Matter SC Materials Science; Physics GA HH326 UT WOS:A1992HH32600138 ER PT J AU SKANTHAKUMAR, S LYNN, JW PENG, JL LI, ZY AF SKANTHAKUMAR, S LYNN, JW PENG, JL LI, ZY TI MAGNETIC ORDER OF CU IN ND2-XCEXCUO4 SO JOURNAL OF MAGNETISM AND MAGNETIC MATERIALS LA English DT Article ID PHASE-TRANSITIONS; ND2CUO4 AB The magnetic ordering in single crystals of Nd2-xCexCuO4 with x = 0.0 to 0.22 has been studied by neutron diffraction measurements. Long-range antiferromagnetic order for Cu is observed for crystals with small Ce concentrations. Both the ordered moment for Cu and the Neel temperature decrease with increasing Ce concentration x. Two Cu spin reorientation transitions are also observed for crystals with small Ce concentrations. The temperature dependence of the (1/2 1/2 0) magnetic Bragg peak shows that these spin reorientation transitions are sharp for the pure sample, while they are not as sharp for the doped samples due to the randomness of the Ce. The fraction of the Cu spins which participate in the spin reorientations also decreases with increasing x. In Nd2CuO4, both spin reorientation transition temperatures increase with magnetic field at the rate of about 1.2 and 0.8 K/T, respectively. C1 NATL INST STAND & TECHNOL, DIV REACTOR, GAITHERSBURG, MD 20899 USA. RP SKANTHAKUMAR, S (reprint author), UNIV MARYLAND, CTR SUPERCONDUCT RES, DEPT PHYS, COLLEGE PK, MD 20742 USA. NR 10 TC 22 Z9 22 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 FEB PY 1992 VL 104 BP 519 EP 520 DI 10.1016/0304-8853(92)90905-4 PN 1 PG 2 WC Materials Science, Multidisciplinary; Physics, Condensed Matter SC Materials Science; Physics GA HH326 UT WOS:A1992HH32600231 ER PT J AU BENNETT, LH SWARTZENDRUBER, LJ KAISER, DL GAYLE, FW BLENDELL, J HABIB, JM SEYOUM, HM AF BENNETT, LH SWARTZENDRUBER, LJ KAISER, DL GAYLE, FW BLENDELL, J HABIB, JM SEYOUM, HM TI THERMOREMANENCE AND MEISSNER EFFECT IN QMG AND SINGLE-CRYSTAL YBCO SO JOURNAL OF MAGNETISM AND MAGNETIC MATERIALS LA English DT Article ID GROWTH; MICROSTRUCTURE AB We compare flux pinning in a single crystal (twinned and detwinned) of YBa2Cu3O7-x (YBCO) with that in a quench-melt-growth (QMG) bulk YBCO sample using measurements of the thermoremanent magnetization and Meissner effect. For temperatures up to 50 K, there is practically no difference in the thermoremanent magnetization of the crystal in the twinned and detwinned states, while above 50 K the remanent flux in the twinned state is larger. The rate of decrease of thermoremanent magnetization with temperature is much lower for the QMG material. The QMG material has practically no Meissner effect over a wide range of applied fields, whereas a considerable difference in Meissner effect is seen between the twinned and detwinned states of the single crystal. C1 UNIV DIST COLUMBIA, WASHINGTON, DC USA. RP BENNETT, LH (reprint author), NATL INST STAND & TECHNOL, GAITHERSBURG, MD USA. NR 7 TC 0 Z9 0 U1 0 U2 0 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0304-8853 J9 J MAGN MAGN MATER JI J. Magn. Magn. Mater. PD FEB PY 1992 VL 104 BP 539 EP 540 DI 10.1016/0304-8853(92)90914-A PN 1 PG 2 WC Materials Science, Multidisciplinary; Physics, Condensed Matter SC Materials Science; Physics GA HH326 UT WOS:A1992HH32600240 ER PT J AU CLINTON, TW LYNN, JW LIU, JZ JIA, YX SHELTON, RN AF CLINTON, TW LYNN, JW LIU, JZ JIA, YX SHELTON, RN TI 2-DIMENSIONAL MAGNETIC CORRELATIONS AND MAGNETIC-ORDERING OF DY AND ER IN DYBA2CU3O7 AND ERBA2CU3O7 SO JOURNAL OF MAGNETISM AND MAGNETIC MATERIALS LA English DT Article AB We have observed two-dimensional magnetic behavior associated with the magnetic ordering of Dy in DyBa2Cu3O7, and have studied the 2D magnetic correlations of Dy in DyBa2Cu3O7 as well as Er in ErBa2Cu3O7. The temperature dependence of the rod of scattering, characteristic of 2D behavior, has been measured above and below the Neel temperature (T(N) congruent-to 0.9 K for Dy, T(N) congruent-to 0.62 K for Er). For both systems the rod intensity, which is proportional to the magnetic susceptibility, is observed to increase as the temperature is decreased until T(N) is reached. Below T(N) the intensity decreases rapidly. The 2D magnetic correlation length is seen to grow continuously with decreasing temperature and then peak at the respective Neel temperatures when long range magnetic order sets in. C1 NATL INST STAND & TECHNOL, GAITHERSBURG, MD 20899 USA. UNIV CALIF DAVIS, DEPT PHYS, DAVIS, CA 95616 USA. RP CLINTON, TW (reprint author), UNIV MARYLAND, DEPT PHYS, CTR SUPERCONDUCT RES, COLLEGE PK, MD 20742 USA. NR 8 TC 4 Z9 4 U1 0 U2 0 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0304-8853 J9 J MAGN MAGN MATER JI J. Magn. Magn. Mater. PD FEB PY 1992 VL 104 BP 625 EP 626 DI 10.1016/0304-8853(92)90955-N PN 1 PG 2 WC Materials Science, Multidisciplinary; Physics, Condensed Matter SC Materials Science; Physics GA HH326 UT WOS:A1992HH32600281 ER PT J AU ZHANG, H LYNN, JW MORRIS, DE AF ZHANG, H LYNN, JW MORRIS, DE TI 2-DIMENSIONAL BILAYER MAGNETIC ORDER OF DY-IONS IN DY2BA4CU7O15 SO JOURNAL OF MAGNETISM AND MAGNETIC MATERIALS LA English DT Article; Proceedings Paper CT INTERNATIONAL CONF ON MAGNETISM CY SEP 02-06, 1991 CL EDINBURGH, SCOTLAND ID ER AB Neutron scattering has been used to investigate the magnetic ordering of Dy ions in the Dy2Ba4Cu7O15 material. A modulated saw-tooth scattering profile is observed, indicative of a coupled-bilayer two-dimensional (2D) system in which the Dy spins within the a-b planes are coupled antiferromagnetically, with T(N) = 1.25 K. The 2D order originates from the crystal structure, as the c-axis spacing of the magnetic ions is approximately 3 times the a-b spacing. In addition, every other a-b plane is shifted along the b-axis by b/2, causing a cancellation of magnetic interactions which completely isolates the bilayers. We anticipate that a similar coupled-bilayer 2D behavior should occur in other R2Ba4Cu7O15 (R = rare earth element, except Er) in which nearest-neighbor spins within the a-b plane are coupled antiferromagnetically. C1 NATL INST STAND & TECHNOL,GAITHERSBURG,MD 20899. MORRIS RES INC,BERKELEY,CA 94704. RP ZHANG, H (reprint author), UNIV MARYLAND,CTR SUPERCONDUCT RES,DEPT PHYS,COLLEGE PK,MD 20742, USA. 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 0304-8853 J9 J MAGN MAGN MATER JI J. Magn. Magn. Mater. PD FEB PY 1992 VL 104 BP 821 EP 822 DI 10.1016/0304-8853(92)90376-Y PN 2 PG 2 WC Materials Science, Multidisciplinary; Physics, Condensed Matter SC Materials Science; Physics GA HH327 UT WOS:A1992HH32700028 ER PT J AU NAGLER, SE TENNANT, DA COWLEY, RA SATIJA, SK PERRING, TG TAYLOR, AD ARAI, M AF NAGLER, SE TENNANT, DA COWLEY, RA SATIJA, SK PERRING, TG TAYLOR, AD ARAI, M TI NEUTRON-SCATTERING STUDY OF QUANTUM EXCITATIONS IN A S=1/2 HEISENBERG ANTIFERROMAGNETIC CHAIN SO JOURNAL OF MAGNETISM AND MAGNETIC MATERIALS LA English DT Article; Proceedings Paper CT INTERNATIONAL CONF ON MAGNETISM CY SEP 02-06, 1991 CL EDINBURGH, SCOTLAND ID FIELD AB Inelastic neutron scattering has been used to study the magnetic excitations of a nearly ideal realisation of a one-dimensional S = 1/2 Heisenberg antiferromagnet, KCuF3. The experiments were performed using the pulsed neutron source ISIS and it is seen that time of flight methods are particularly well suited to the study of low dimensional systems. The excitation spectrum consists of a quantum continuum of excited states extending up to energies double that of the usual antiferromagnetic zone boundary spin-wave mode. The scattering can be described very well by a theoretical ansatz for the dynamical correlation function. C1 NATL INST STAND & TECHNOL,GAITHERSBURG,MD. RUTHERFORD APPLETON LAB,DIDCOT OX11 0QX,OXON,ENGLAND. UNIV FLORIDA,DEPT PHYS,GAINESVILLE,FL 32611. RP NAGLER, SE (reprint author), UNIV OXFORD,DEPT PHYS,CLARENDON LAB,OXFORD,ENGLAND. RI Nagler, Stephen/B-9403-2010; Nagler, Stephen/E-4908-2010; Tennant, David/Q-2497-2015 OI Nagler, Stephen/0000-0002-7234-2339; Tennant, David/0000-0002-9575-3368 NR 5 TC 2 Z9 2 U1 1 U2 3 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 FEB PY 1992 VL 104 BP 847 EP 848 DI 10.1016/0304-8853(92)90389-6 PN 2 PG 2 WC Materials Science, Multidisciplinary; Physics, Condensed Matter SC Materials Science; Physics GA HH327 UT WOS:A1992HH32700041 ER PT J AU BENNETT, LH MCMICHAEL, RD SWARTZENDRUBER, LJ SHULL, RD WATSON, RE AF BENNETT, LH MCMICHAEL, RD SWARTZENDRUBER, LJ SHULL, RD WATSON, RE TI MONTE-CARLO AND MEAN-FIELD CALCULATIONS OF THE MAGNETOCALORIC EFFECT OF FERROMAGNETICALLY INTERACTING CLUSTERS SO JOURNAL OF MAGNETISM AND MAGNETIC MATERIALS LA English DT Article; Proceedings Paper CT INTERNATIONAL CONF ON MAGNETISM CY SEP 02-06, 1991 CL EDINBURGH, SCOTLAND ID MAGNETIC REFRIGERATION; ROOM-TEMPERATURE AB The magnetic entropy change of a ferromagnet induced by an application of a magnetic field is greatest in the temperature region near the Curie point, and the magnitude of the effect is expected to rise monotonically with the size of the individual moments which make up the material. We explore the case of nanocomposite materials with ferromagnetically interacting clusters having large cluster magnetic moments as a function of cluster size. As cluster size increases, both Monte Carlo and mean-field calculations show a decrease in the entropy change at T(c) for a given applied field and constant total magnetic moment, and an increase in the entropy change well above T(c). In addition, for the first time, we present a comparison of the results of mean-field and Monte Carlo calculations of the magnetocaloric effect in classical Heisenberg ferromagnets. Previous calculations of the magnetocaloric effect have taken the mean-field approach, which is known to underestimate the spontaneous magnetization below T(c). These issues are relevant to devices employing magnetic refrigeration. C1 BROOKHAVEN NATL LAB,UPTON,NY 11973. RP BENNETT, LH (reprint author), NATL INST STAND & TECHNOL,GAITHERSBURG,MD 20899, USA. RI C, Y/G-5456-2010; McMichael, Robert/J-8688-2012; Shull, Robert/F-5971-2013; OI McMichael, Robert/0000-0002-1372-664X NR 11 TC 41 Z9 42 U1 1 U2 7 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 FEB PY 1992 VL 104 BP 1094 EP 1095 DI 10.1016/0304-8853(92)90504-H PN 2 PG 2 WC Materials Science, Multidisciplinary; Physics, Condensed Matter SC Materials Science; Physics GA HH327 UT WOS:A1992HH32700156 ER PT J AU CHILDRESS, JR CHIEN, CL RHYNE, JJ ERWIN, RW AF CHILDRESS, JR CHIEN, CL RHYNE, JJ ERWIN, RW TI SMALL-ANGLE NEUTRON-SCATTERING OF NANOMETER-SIZE MAGNETIC PARTICLES SO JOURNAL OF MAGNETISM AND MAGNETIC MATERIALS LA English DT Article; Proceedings Paper CT INTERNATIONAL CONF ON MAGNETISM CY SEP 02-06, 1991 CL EDINBURGH, SCOTLAND AB Nanoscale Fe particles in an Al2O3 matrix have been investigated by Small-Angle Neutron Scattering (SANS), in addition to SQUID magnetometry and Mossbauer spectroscopy. SANS data analysis indicates an increase of the ferromagnetic correlation length as the temperature decreases, with saturation at roughly the particle size. The amplitude of this scattering decreases with temperature, indicating that it is likely dynamic in origin. There is a second component of the SANS at the smallest wavevector transfers, which we believe arises from inter-particle correlations. The amplitude of this component increases with decreasing temperature, as expected for order parameter scattering. C1 NIST,DIV REACTOR,GAITHERSBURG,MD 20899. UNIV MISSOURI,RES REACTOR,COLUMBIA,MO 65211. RP CHILDRESS, JR (reprint author), JOHNS HOPKINS UNIV,DEPT PHYS & ASTRON,BALTIMORE,MD 21218, USA. NR 4 TC 17 Z9 17 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 FEB PY 1992 VL 104 BP 1585 EP 1586 DI 10.1016/0304-8853(92)91464-5 PN 3 PG 2 WC Materials Science, Multidisciplinary; Physics, Condensed Matter SC Materials Science; Physics GA HH328 UT WOS:A1992HH32800044 ER PT J AU SALAMON, MB BEACH, RS BORCHERS, JA ERWIN, RW FLYNN, CP MATHENY, A RHYNE, JJ TSUI, F AF SALAMON, MB BEACH, RS BORCHERS, JA ERWIN, RW FLYNN, CP MATHENY, A RHYNE, JJ TSUI, F TI MAGNETISM OF RARE-EARTH/Y AND RARE-EARTH/LU SUPERLATTICES AND FILMS SO JOURNAL OF MAGNETISM AND MAGNETIC MATERIALS LA English DT Article; Proceedings Paper CT INTERNATIONAL CONF ON MAGNETISM CY SEP 02-06, 1991 CL EDINBURGH, SCOTLAND ID METAL SUPER-LATTICES; DY-Y SUPERLATTICES; GROWTH; ORDER AB The ability to tailor-make crystalline metallic superlattices with selected orientations has opened a new field of magnetism. We review work on rare-earth/yttrium and /lutetium superlattices and films, with emphasis on the effect of epitaxy on the phase diagram and on the propagation of magnetic order through the nonmagnetic component. C1 NIST,GAITHERSBURG,MD 20899. RP SALAMON, MB (reprint author), UNIV ILLINOIS,DEPT PHYS,URBANA,IL 61801, USA. NR 20 TC 4 Z9 4 U1 1 U2 3 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 FEB PY 1992 VL 104 BP 1729 EP 1733 DI 10.1016/0304-8853(92)91525-X PN 3 PG 5 WC Materials Science, Multidisciplinary; Physics, Condensed Matter SC Materials Science; Physics GA HH328 UT WOS:A1992HH32800105 ER PT J AU KLOSOWSKI, P GIEBULTOWICZ, TM SAMARTH, N LUO, H FURDYNA, JK RHYNE, JJ AF KLOSOWSKI, P GIEBULTOWICZ, TM SAMARTH, N LUO, H FURDYNA, JK RHYNE, JJ TI MAGNETIC CRITICAL PHENOMENA IN FCC ANTIFERROMAGNETS - ROLE OF STRAIN AND DIMENSIONALITY SO JOURNAL OF MAGNETISM AND MAGNETIC MATERIALS LA English DT Article; Proceedings Paper CT INTERNATIONAL CONF ON MAGNETISM CY SEP 02-06, 1991 CL EDINBURGH, SCOTLAND ID SYMMETRY-BREAKING FIELDS; 1ST-ORDER TRANSITIONS; PHASE-TRANSITION AB We report neutron diffraction studies of MnTe epitaxial layers and MnTe/ZnTe strained superlattices prepared on (100) GaAs substrates by molecular beam epitaxy. In these systems MnTe grows in the Zinc-Blende (ZB) phase, in contrast to bulk MnTe, found in the NiAs form. The magnetic interactions are short range and antiferromagnetic, and result in a fcc type-III antiferromagnetic ordering (AFM-III). The renormalization group theories predict a fluctuation-induced first order phase transition for such system in the absence of strain. Such transition is indeed reported in previous work on bulk beta-MnS, and is observed in our MnTe epilayers. The epilayers seem to be virtually strain-free, with all three AFM-III domains present. This picture is complicated, however, by our discovery of a substantial magnetostriction in MnTe. This magnetostriction, observed by precise measurement of the lattice constant, seems to result in the relative population shifts between the domains. The superlattices with the MnTe layer thickness of 30 and 60 angstrom exhibit a single AFM-III domain that has the lowest strain-determined energy, consistent with observed small tetragonal distortion of the MnTe lattice, resulting from the ZnTe and MnTe lattice mismatch. In the presence of strain the dimensionality of the order parameter is reduced from 6 to 2, in which case the theory predicts the continuous phase transition. This is indeed observed experimentally. C1 NIST,GAITHERSBURG,MD 20899. UNIV MISSOURI,RES REACTOR,COLUMBIA,MO 65211. 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 15 TC 6 Z9 6 U1 0 U2 3 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 FEB PY 1992 VL 104 BP 1795 EP 1797 PN 3 PG 3 WC Materials Science, Multidisciplinary; Physics, Condensed Matter SC Materials Science; Physics GA HH328 UT WOS:A1992HH32800133 ER PT J AU TSUI, F FLYNN, CP SALAMON, MB BORCHERS, JA ERWIN, RW RHYNE, JJ AF TSUI, F FLYNN, CP SALAMON, MB BORCHERS, JA ERWIN, RW RHYNE, JJ TI LAYER THICKNESS DEPENDENCE OF ANISOTROPIC COUPLING IN GD/Y SUPERLATTICES SO JOURNAL OF MAGNETISM AND MAGNETIC MATERIALS LA English DT Article; Proceedings Paper CT INTERNATIONAL CONF ON MAGNETISM CY SEP 02-06, 1991 CL EDINBURGH, SCOTLAND ID DY-Y SUPERLATTICES; EXCHANGE; FE/CR AB The asymmetry of spin-coupling through nonmagnetic yttrium interlayers in b-axis Gd/Y MBE superlattices grown on [1010BAR] Y substrates has been examined using SQUID magnetometry and neutron scattering. For c-axis Gd/Y superlattices, the Gd layers align ferromagnetically or antiferromagnetically across the intervening layers depending in an oscillatory manner on the Y thickness with interlayer coupling strengths of approximately 1 kOe. Neutron scans for b-[Gd43 angstrom\Y52 angstrom]85 demonstrate that the Gd moments anti-align across the Y in zero field. The Gd layers in samples b-[Gd47 angstrom\Y42 angstrom]50 and b-[Gd60 angstrom\Y26 angstrom]80 with thinner Y interlayers are aligned at temperatures less than 90 K. The saturation fields obtained for these samples are 80, 35 and 20 Oe at 150 K, respectively. This result suggests that the antiferromagnetic coupling mechanism is much weaker than that for the c-axis superlattices. We will compare models for the coupling based on RKKY and dipolar interactions. C1 NIST,GAITHERSBURG,MD 20899. UNIV ILLINOIS,MAT RES LAB,URBANA,IL 61801. RP TSUI, F (reprint author), UNIV ILLINOIS,DEPT PHYS,1110 W GREEN ST,URBANA,IL 61801, 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 0304-8853 J9 J MAGN MAGN MATER JI J. Magn. Magn. Mater. PD FEB PY 1992 VL 104 BP 1901 EP 1902 DI 10.1016/0304-8853(92)91596-L PN 3 PG 2 WC Materials Science, Multidisciplinary; Physics, Condensed Matter SC Materials Science; Physics GA HH328 UT WOS:A1992HH32800176 ER PT J AU BEACH, RS BORCHERS, JA ERWIN, RW FLYNN, CP MATHENY, A RHYNE, JJ SALAMON, MB AF BEACH, RS BORCHERS, JA ERWIN, RW FLYNN, CP MATHENY, A RHYNE, JJ SALAMON, MB TI MAGNETIC ORDER IN DY/LU SUPERLATTICES SO JOURNAL OF MAGNETISM AND MAGNETIC MATERIALS LA English DT Article ID Y SUPERLATTICES AB Several superlattices containing alternate layers of the rare earth elements dysprosium and lutetium were grown by molecular beam epitaxy. Neutron diffraction shows that these samples develop a helical phase in the (approximately 40 angstrom) Dy layers at T(N) = 178 K which propagates coherently across the nonmagnetic Lu (20-55 angstrom thick). The Dy layers order ferromagnetically at temperatures which vary from 140 to 160 K (the ferromagnetic phase in the bulk material appears at 85 K). Below T(C) the ferromagnetic Dy layers may be either aligned or anti-aligned. The transition is accompanied by a distortion of the superlattice basal plane comparable to that which occurs in bulk Dy. We also observe an approximately 80 K increase in T(C) in thin Lu/Dy (< 150 angstrom)/Lu films. We discuss how the observed high T(C) may be related to the elastic coupling of the Dy to Lu. C1 NIST, GAITHERSBURG, MD 20899 USA. RP UNIV ILLINOIS, DEPT PHYS, URBANA, IL 61801 USA. NR 7 TC 12 Z9 12 U1 0 U2 2 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0304-8853 EI 1873-4766 J9 J MAGN MAGN MATER JI J. Magn. Magn. Mater. PD FEB PY 1992 VL 104 BP 1915 EP 1917 DI 10.1016/0304-8853(92)91602-P PN 3 PG 3 WC Materials Science, Multidisciplinary; Physics, Condensed Matter SC Materials Science; Physics GA HH328 UT WOS:A1992HH32800182 ER PT J AU ROBINS, LH FARABAUGH, EN FELDMAN, A AF ROBINS, LH FARABAUGH, EN FELDMAN, A TI SPATIALLY AND SPECTRALLY RESOLVED CATHODOLUMINESCENCE OF HOT-FILAMENT CHEMICAL-VAPOR-DEPOSITED DIAMOND PARTICLES SO JOURNAL OF MATERIALS RESEARCH LA English DT Article ID FILMS; NITROGEN AB Spectrally resolved cathodoluminescence (CL) images and spatially resolved CL spectra were obtained from two specimens grown by hot-filament chemical vapor deposition. Each specimen consisted of a large number of unconnected diamond particles with cubo-octahedral and pseudo-fivefold twinned growth habits. The growth temperature was nominally 600-degrees-C for one specimen and 750-degrees-C for the other. In the 1.5-3.5 eV range, the spectra are composed of four defect and impurity related bands: there are three bands with zero-phonon lines at 1.68 eV, 2.156 eV, and 2.325 eV. and one broad band centered at 2.85 eV. A weak peak at 5.27 eV, due to exciton recombination, was also observed. Spectrally resolved images of the two most intense CL bands, at 2.156 eV and 2.85 eV, were obtained for several particles. In the low-temperature specimen, bright regions in images of the 2.156 eV band are correlated with {111} facets; bright regions in images of the 2.85 eV band are correlated in some cases with the central regions of {100} facets and in other cases with {111} facets. In the intermediate-temperature specimen, bright regions in the images of both bands are correlated with {100} facets. A model of competing recombination at different types of CL centers and nonradiative centers is proposed to facilitate the interpretation of the experimental results. For the low-temperature specimen, the model suggests that the 2.156 eV CL centers are located primarily in {111} growth sectors and the 2.85 eV CL centers are distributed relatively uniformly; images of the two dominant CL bands are predicted to have a complementary relationship in particles where there are few competing nonradiative centers. For the intermediate-temperature specimens, the model suggests that nonradiative recombination is dominant, and that the CL image contrast arises primarily from a nonuniform distribution of nonradiative centers. RP ROBINS, LH (reprint author), NATL INST STAND & TECHNOL,GAITHERSBURG,MD 20899, USA. NR 21 TC 8 Z9 8 U1 0 U2 1 PU MATERIALS RESEARCH SOCIETY PI PITTSBURGH PA 9800 MC KNIGHT ROAD SUITE 327, PITTSBURGH, PA 15237 SN 0884-2914 J9 J MATER RES JI J. Mater. Res. PD FEB PY 1992 VL 7 IS 2 BP 394 EP 403 DI 10.1557/JMR.1992.0394 PG 10 WC Materials Science, Multidisciplinary SC Materials Science GA HC899 UT WOS:A1992HC89900022 ER PT J AU RAIZEN, MG GILLIGAN, JM BERGQUIST, JC ITANO, WM WINELAND, DJ AF RAIZEN, MG GILLIGAN, JM BERGQUIST, JC ITANO, WM WINELAND, DJ TI LINEAR TRAP FOR HIGH-ACCURACY SPECTROSCOPY OF STORED IONS SO JOURNAL OF MODERN OPTICS LA English DT Article ID QUANTUM JUMPS; SINGLE-ION; LASER; FLUORESCENCE AB In a linear r.f. Paul trap, 'crystallized' structures of laser-cooled Hg-199+ ions are observed. The ground-state hyperfine transition at 40.5 GHz is observed in microwave-optical double-resonance spectroscopy. Future prospects are also discussed. C1 NATL INST STAND & TECHNOL,DIV TIME & FREQUENCY,BOULDER,CO 80303. RI Gilligan, Jonathan/I-8938-2014 OI Gilligan, Jonathan/0000-0003-1375-6686 NR 31 TC 76 Z9 76 U1 2 U2 9 PU TAYLOR & FRANCIS LTD PI LONDON PA ONE GUNDPOWDER SQUARE, LONDON, ENGLAND EC4A 3DE SN 0950-0340 J9 J MOD OPTIC JI J. Mod. Opt. PD FEB PY 1992 VL 39 IS 2 BP 233 EP 242 DI 10.1080/09500349214550241 PG 10 WC Optics SC Optics GA HJ044 UT WOS:A1992HJ04400003 ER PT J AU BURKHOLDER, JB HAMMER, PD HOWARD, CJ TOWLE, JP BROWN, JM AF BURKHOLDER, JB HAMMER, PD HOWARD, CJ TOWLE, JP BROWN, JM TI FOURIER-TRANSFORM SPECTROSCOPY OF THE NU-2 AND NU-3 BANDS OF HO2 SO JOURNAL OF MOLECULAR SPECTROSCOPY LA English DT Article ID LASER MAGNETIC-RESONANCE; ASYMMETRIC-TOP MOLECULES; 9.1 MU-M; FUNDAMENTAL-BAND; MICROWAVE-SPECTRUM; RATE CONSTANTS; LOW-PRESSURES; GAS-PHASE; RADICALS; KINETICS C1 UNIV COLORADO,COOPERAT INST RES ENVIRONM SCI,BOULDER,CO 80302. PHYS CHEM LAB,OXFORD OX1 3QZ,ENGLAND. RP BURKHOLDER, JB (reprint author), NOAA,AERON LAB,RE AL2,325 BROADWAY,BOULDER,CO 80303, USA. RI Burkholder, James/H-4914-2013 NR 32 TC 42 Z9 43 U1 1 U2 5 PU ACADEMIC PRESS INC JNL-COMP SUBSCRIPTIONS PI SAN DIEGO PA 525 B ST, STE 1900, SAN DIEGO, CA 92101-4495 SN 0022-2852 J9 J MOL SPECTROSC JI J. Mol. Spectrosc. PD FEB PY 1992 VL 151 IS 2 BP 493 EP 512 DI 10.1016/0022-2852(92)90582-9 PG 20 WC Physics, Atomic, Molecular & Chemical; Spectroscopy SC Physics; Spectroscopy GA HA543 UT WOS:A1992HA54300020 ER EF