FN Thomson Reuters Web of Science™ VR 1.0 PT J AU Marks, KM AF Marks, KM TI Resolution of the Scripps/NOAA marine gravity field from satellite altimetry SO GEOPHYSICAL RESEARCH LETTERS LA English DT Article ID GEOSAT AB The July 1995 declassification of the entire Geosat GM satellite altimeter data set enabled a joint Scripps/NOAA effort to compute a new (version 7.2) marine gravity field on a 2-minute grid. This gravity field covers the world's oceans between 72 degrees N and 72 degrees S, and is derived from a combination of ERS-1 and Geosat GM and ERM data. An earlier NOAA Geosat-only gravity field solution was confined to the southern latitudes because the 1992 declassification was limited to GM data south of 30 degrees S. A simple coherence analysis between accurately-navigated ship gravity profiles and comparable gravity profiles obtained from the gravity grids reveals that the Scripps/NOAA gravity field is coherent with ship gravity down to similar to greater than or equal to 23-30 km. This slight increase in resolution over the previous NOAA Geosat-only gravity field (short-wavelength resolution of similar to 26-30 km) implies that the increased spatial coverage provided by the ERS-1 altimeter, when combined with Geosat, improves the solution. Coherence analyses between satellite gravity and ship topography, and ship gravity and ship topography, show that even shorter wavelength gravity anomalies (similar to 13 km) are present in sea-surface measurements made by ship. Even so, the Scripps/NOAA marine gravity field does an excellent job of resolving most of the short-wavelength gravity anomalies covering the world's oceans. RP Marks, KM (reprint author), NOAA,GEOSCI LAB,NATL OCEAN SERV,N-OES12,1305 E WEST HIGHWAY,SILVER SPRING,MD 20910, USA. RI Marks, Karen/F-5610-2010; Wright, Dawn/A-4518-2011 OI Marks, Karen/0000-0001-6524-1495; Wright, Dawn/0000-0002-2997-7611 NR 9 TC 28 Z9 28 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 AUG 1 PY 1996 VL 23 IS 16 BP 2069 EP 2072 DI 10.1029/96GL02059 PG 4 WC Geosciences, Multidisciplinary SC Geology GA VA620 UT WOS:A1996VA62000018 ER PT J AU Conway, RR Stevens, MH Cardon, JG Zasadil, SE Brown, CM Morrill, JS Mount, GH AF Conway, RR Stevens, MH Cardon, JG Zasadil, SE Brown, CM Morrill, JS Mount, GH TI Satellite measurements of hydroxyl in the mesosphere SO GEOPHYSICAL RESEARCH LETTERS LA English DT Article ID OH; OD AB The global distribution of hydroxyl (OH) in the middle atmosphere was recently measured by the Middle Atmosphere High Resolution Spectrograph Investigation (MAHRSI) on a satellite deployed and retrieved by the space shuttle. During 75 orbits, MAHRSI acquired 1800 daytime limb scans of the OH ultraviolet solar resonance fluorescence intensity. Each limb scan extends over the altitude region from 30 to 90 km and across 10 degrees of latitude between 53 degrees S and 63 degrees N. OH number densities were retrieved using a Twomey regularization scheme constrained by the smoothness of the retrieved profile. Results provide a detailed description of the diurnal variation of mesospheric OH. Midmorning OH densities had a well defined peak of about 6 x 10(6) cm(-3) near 70 km, a broad minimum centered near 64 km, and rose to about 1 x 10(7) cm(-3) at 50 km. This profile is in substantial disagreement with photochemical model predictions [Summers et al., this issue]. The observations are compared with the two previous measurements. C1 COMPUTAT PHYS INC,FAIRFAX,VA 22031. NOAA,AERON LAB,BOULDER,CO 80303. RP Conway, RR (reprint author), USN,RES LAB,EO HULBURT CTR SPACE RES,WASHINGTON,DC 20375, USA. OI Stevens, Michael/0000-0003-1082-8955 NR 17 TC 27 Z9 27 U1 0 U2 1 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 SN 0094-8276 J9 GEOPHYS RES LETT JI Geophys. Res. Lett. PD AUG 1 PY 1996 VL 23 IS 16 BP 2093 EP 2096 DI 10.1029/96GL01401 PG 4 WC Geosciences, Multidisciplinary SC Geology GA VA620 UT WOS:A1996VA62000024 ER PT J AU Bodhaine, BA McKenzie, RL Johnston, PV Hofmann, DJ Dutton, EG Schnell, RC Barnes, JE Ryan, SC Kotkamp, M AF Bodhaine, BA McKenzie, RL Johnston, PV Hofmann, DJ Dutton, EG Schnell, RC Barnes, JE Ryan, SC Kotkamp, M TI New ultraviolet spectroradiometer measurements at Mauna Loa observatory SO GEOPHYSICAL RESEARCH LETTERS LA English DT Article ID SPECTRAL IRRADIANCE MEASUREMENTS; OZONE; UV AB A research-grade scanning UV spectroradiometer was installed at Mauna Loa Observatory (MLO), Hawaii, in July 1995. This instrument, built around a commercially available double monochromator, is interfaced with a PC to provide automatic control and data acquisition. The spectral range sampled by the instrument is 290-450 nn, and the bandpass is about 1 nm. A complete scan requires about 200 seconds and is performed every 5 degrees of solar zenith angle (SZA) during daylight hours. Calibration is performed on site at g-month intervals using a 1000-W standard quartz-halogen FEL lamp with calibration traceable to NIST. The UV irradiances measured at MLO are much more intense than at low altitude midlatitude locations. For observations at a SZA of 45 degrees, the erythemally weighted UV can exceed 18 mu W cm(-2), which is approximately 15-20% greater than the maxima seen at Lauder, New Zealand, for similar ozone amounts. The difference is primarily due to the higher altitude at MLO. For overhead sun conditions at MLO, erythemal UV can exceed 45 mu W cm(-2) which to our knowledge is the highest recorded anywhere at the Earth's surface. UV irradiance is strongly correlated (inversely) with Dobson spectrophotometer total ozone measurements at MLO, with higher correlations at shorter wavelengths. The radiative amplification factor (RAF) for erythema at MLO is about 1.44 +/- 0.46 at SZA 45 degrees. Using ozone retrievals from the UV spectra themselves, the deduced RAF for erythema is 1.26 +/- 0.38. The RAFs for erythema at SZA 60 degrees are similar, and in agreement with other determinations within the limits of experimental uncertainty. C1 NIWA LAUDER,CENTAL OTAGO 9182,NEW ZEALAND. NOAA,MAUNA LOA OBSERV,HILO,HI 96720. RP Bodhaine, BA (reprint author), NOAA,CLIMATE MONITORING & DIAGNOST LAB,R E CG1,325 BROADWAY,BOULDER,CO 80303, USA. NR 13 TC 18 Z9 18 U1 0 U2 2 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 SN 0094-8276 J9 GEOPHYS RES LETT JI Geophys. Res. Lett. PD AUG 1 PY 1996 VL 23 IS 16 BP 2121 EP 2124 DI 10.1029/96GL01954 PG 4 WC Geosciences, Multidisciplinary SC Geology GA VA620 UT WOS:A1996VA62000031 ER PT J AU Borrmann, S Solomon, S Dye, JE Luo, BP AF Borrmann, S Solomon, S Dye, JE Luo, BP TI The potential of cirrus clouds for heterogeneous chlorine activation SO GEOPHYSICAL RESEARCH LETTERS LA English DT Article ID ARCTIC STRATOSPHERIC EXPEDITION; SULFURIC-ACID; SCATTERING; CLONO2 AB The ER-2 data from ascents and descents through layers of cirrus clouds are utilized to study the heterogeneous reactions of ClONO2 with H2O, of HOCl and ClONO2 with HCl, and their potential role for the activation of chlorine in the tropopause region, which could affect ozone there. Lacking measured data for the three chlorine containing molecules their abundances as a function of altitude have been calculated fr om a 2D model. The aerosol surface data measured by a Forward Scattering Spectrometer Probe (FSSP-300) on the ER-2 were corrected for the expected asphericity of cirrus cloud particles by means of a T-matrix method. The results indicate considerable potential of cirrus clouds for chlorine activation. If ClONO2 and HCl are present in the tropopause region they are likely to be quickly converted to active chlorine by cirrus clouds. C1 NOAA, AERON LAB, BOULDER, CO 80303 USA. NATL CTR ATMOSPHER RES, BOULDER, CO 80307 USA. MAX PLANCK INST CHEM, D-55128 MAINZ, GERMANY. RP Borrmann, S (reprint author), UNIV MAINZ, INST ATMOSPHER PHYS, BECHERWEG 21, D-55099 MAINZ, GERMANY. RI Borrmann, Stephan/E-3868-2010 NR 15 TC 103 Z9 103 U1 0 U2 3 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 AUG 1 PY 1996 VL 23 IS 16 BP 2133 EP 2136 DI 10.1029/96GL01957 PG 4 WC Geosciences, Multidisciplinary SC Geology GA VA620 UT WOS:A1996VA62000034 ER PT J AU Gage, KS McAfee, JR Williams, CR AF Gage, KS McAfee, JR Williams, CR TI Recent changes in tropospheric circulation over the central equatorial Pacific SO GEOPHYSICAL RESEARCH LETTERS LA English DT Article ID SOUTHERN OSCILLATION; RADAR AB During the past five years an unusually prolonged warm event has occurred in the equatorial Pacific ocean. As recently discussed by Trenberth and Hear [1996], this prolonged warm event represents a major climate perturbation in the historical record of the Southern Oscillation. The region most affected by the warm event is the central equatorial Pacific. Upper air observations from this region are sparse. However, since 1986 observations of tropospheric winds have been nearly continuously using the made Christmas Island VHF wind profiler, These profiler observations are examined for evidence of a deep tropospheric change in circulation during the past five years by comparing observations for 1990-1995 with those taken before 1990. It is shown that there has been a substantial decrease in the magnitude of tropospheric zonal winds observed at Christmas Island. At the same time, the magnitude of the pressure difference between Tahiti and Darwin has also been substantially reduced. These observations are consistent with a warm event in which the centers of active over the western Pacific have moved eastward toward the dateline. We conclude that there has been a reduction in the tropospheric zonal winds over the central equatorial Pacific that are normally associated with the gradients of surface pressure and SST across this region. C1 UNIV COLORADO,CIRES,BOULDER,CO 80309. RP Gage, KS (reprint author), NOAA,AERON LAB,CIRES,R-E-AL3,325 BROADWAY,BOULDER,CO 80303, USA. RI Williams, Christopher/A-2723-2015 OI Williams, Christopher/0000-0001-9394-8850 NR 13 TC 5 Z9 5 U1 0 U2 0 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 SN 0094-8276 J9 GEOPHYS RES LETT JI Geophys. Res. Lett. PD AUG 1 PY 1996 VL 23 IS 16 BP 2149 EP 2152 DI 10.1029/96GL01961 PG 4 WC Geosciences, Multidisciplinary SC Geology GA VA620 UT WOS:A1996VA62000038 ER PT J AU Dill, K Bearden, DW AF Dill, K Bearden, DW TI Detection of human asialo-alpha(1)-acid glycoprotein using a heterosandwich immunoassay in conjunction with the light addressable potentiometric sensor SO GLYCOCONJUGATE JOURNAL LA English DT Article DE alpha(1)-acid glycoprotein; asialo-alpha(1)-acid glycoprotein; heterosandwich immunoassay; light addressable potentiometric sensor ID ALPHA-1-ACID GLYCOPROTEIN; CARBOHYDRATE MOIETIES; MONOCLONAL-ANTIBODY; BLOOD CLEARANCE; CHAINS; MOUSE; GLYCOSYLATION; EXPRESSION AB Highly specific detection of human alpha(1)-acid glycoprotein (AGP) and asialo-cui-acid glycoprotein (asialo-AGP) was made possible by use of a sandwich immunoassay. The glycoproteins were sandwiched between biotinylated and fluoresceinated polyclonal rabbit anti-human AGP antibodies. Additionally, asialo-AGP could be distinctly detected, apart from AGP, via the formation of a heterosandwich immunoassay using biotinylated polyclonal rabbit antihuman AGP and the lectin, fluoresceinated ricin toxin. Streptavidin was added to the formed immunocomplexes and the immunocomplexes captured on a biotinylated nitrocellulose membrane. The signal generator, urease conjugate of an anti-fluorescein antibody, was then bound to the complex on the membrane. The rate of pH change under microvolume conditions (0.6 mu l) was monitored using a silicon chip-based, light addressable potentiometer sensor. Results indicated that AGP and asialo-AGP can be detected to the 2 pg level when two antibodies are used to form the immunocomplex. Asialo-AGP can be detected down to 250 pg when the heterosandwich immunoassay is used; this assay exhibited no response up to 10 ng for native AGP or asialofetuin. Both immunoassays can be used to quantify the level of AGP and asialo-AGP in solution. Although the assay presented is very specific for AGP, asialo-AGP and terminal galactose, it is readily adaptable for the detection of any glycoprotein and terminal carbohydrate (or branched structure) by use of a protein-specific antibody and various lectins. C1 NATL MARINE FISHERIES SERV LAB,CHARLESTON,SC 29422. RP Dill, K (reprint author), MOL DEVICES CORP,1311 ORLEANS DR,SUNNYVALE,CA 94089, USA. NR 21 TC 4 Z9 4 U1 2 U2 3 PU CHAPMAN HALL LTD PI LONDON PA 2-6 BOUNDARY ROW, LONDON, ENGLAND SE1 8HN SN 0282-0080 J9 GLYCOCONJUGATE J JI Glycoconjugate J. PD AUG PY 1996 VL 13 IS 4 BP 637 EP 641 DI 10.1007/BF00731452 PG 5 WC Biochemistry & Molecular Biology SC Biochemistry & Molecular Biology GA VC809 UT WOS:A1996VC80900020 PM 8872121 ER PT J AU Tofani, S Ossola, P dAmore, G Anglesio, L Kanda, M Novotny, DR AF Tofani, S Ossola, P dAmore, G Anglesio, L Kanda, M Novotny, DR TI A three-loop antenna system for performing near-field measurements of electric and magnetic fields from video display terminals SO IEEE TRANSACTIONS ON ELECTROMAGNETIC COMPATIBILITY LA English DT Article AB This paper discusses the use of a three-loop antenna system (TLAS) for near-field measurement of electric and magnetic fields from video display terminals (VDT's). We calculated the electric and magnetic dipole moments to derive the electric and magnetic field patterns in the near field region, Electric and magnetic fields, emitted by several different models of VDT's, were evaluated with the TLAS and were compared with those measured by conventional electric and magnetic field probes at different distances and directions from VDT's. A good correlation (+/-1.6 dB) between the two measurement techniques. was found, This agreement is within the accuracy (+/-2 dB) of the conventional field probe measurements. C1 NIST,DIV ELECTROMAGNET FIELDS,BOULDER,CO 80303. RP Tofani, S (reprint author), SERV FIS SANITARIA,I-10015 IVREA,ITALY. NR 7 TC 8 Z9 8 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 0018-9375 J9 IEEE T ELECTROMAGN C JI IEEE Trans. Electromagn. Compat. PD AUG PY 1996 VL 38 IS 3 BP 341 EP 347 DI 10.1109/15.536064 PG 7 WC Engineering, Electrical & Electronic; Telecommunications SC Engineering; Telecommunications GA VF250 UT WOS:A1996VF25000017 ER PT J AU Mo, T AF Mo, T TI Prelaunch calibration of the advanced microwave sounding unit-A for NOAA-K SO IEEE TRANSACTIONS ON MICROWAVE THEORY AND TECHNIQUES LA English DT Article AB The thermal-vacuum chamber calibration data from the advanced microwave sounding unit-A (AMSU-A) for NOAA-K, which will be launched in 1997, were analyzed to evaluate the instrument performance, including calibration accuracy, nonlinearity, and temperature sensitivity, Particularly, the nonlinearity parameters which will be used for correcting the nonlinear contributions from an imperfect square-law detector were determined from this data analysis, It was found that the calibration accuracies (differences between the measured scene radiances and those calculated from a linear two-point calibration formula) are polarization-dependent. Channels with vertical polarizations show little cold biases at the lowest scene target temperature 84 K, while those with horizontal polarizations all have appreciable cold biases, which can be up to 0.6 K, It is unknown where these polarization-dependent cold biases originate, but the instrument's manufacturer suggests that the source of the observed biases is probably due to some low-level coherent radiation leakage from the instrument itself, The existence and magnitude of nonlinearities in each channel were established and a quadratic formula for modeling these nonlinear contributions was developed, The model was characterized by a single parameter u, values of which were obtained for each channel via least-squares fit to the data, Using the best-fit u values, we performed a series of simulations of the quadratic corrections which would be expected from the space data after the launch of AMSU-A on NOAA-K, In these simulations, the cosmic background temperature of 2.73 K (instead of 84 K that was used in the thermal-vacuum chamber test) was adopted as one of the two reference points of calibration, The largest simulated nonlinear correction is about 0.3 K, which occurs at channel 15 when the instrument temperature is at 38 degrees C, Others are less than 0.2 K in the remaining channels. RP Mo, T (reprint author), NOAA,NATL ENVIRONM SATELLITE DATA & INFORMAT SERV,OFF RES & APPLICAT,SATELLITE RES LAB,WASHINGTON,DC 20233, USA. RI Mo, Tsan/F-5614-2010 NR 8 TC 58 Z9 63 U1 2 U2 6 PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017-2394 SN 0018-9480 J9 IEEE T MICROW THEORY JI IEEE Trans. Microw. Theory Tech. PD AUG PY 1996 VL 44 IS 8 BP 1460 EP 1469 DI 10.1109/22.536029 PG 10 WC Engineering, Electrical & Electronic SC Engineering GA VC774 UT WOS:A1996VC77400009 ER PT J AU Dunne, KA Willmott, CJ AF Dunne, KA Willmott, CJ TI Global distribution of plant-extractable water capacity of soil SO INTERNATIONAL JOURNAL OF CLIMATOLOGY LA English DT Article DE plant-extractable water capacity of soil; soil moisture; available water capacity; global soil moisture; global water budget ID GENERAL-CIRCULATION MODELS; SPATIAL VARIABILITY; MOISTURE; CLIMATE; LAND; RETENTION; CARBON; CYCLE AB Plant-extractable water capacity of soil is the amount of water that can be extracted from the soil to fulfill evapotranspiration demands. It is often assumed to be spatially invariant in large-scale computations of the soil-water balance. Empirical evidence, however, suggests that this assumption is incorrect. In this paper, we estimate the global distribution of the plant-extractable water capacity of soil. A representative soil profile, characterized by horizon (layer) particle size data and thickness, was created for each soil unit mapped by FAO (Food and Agriculture Organization of the United Nations)/Unesco. Soil organic matter was estimated empirically from climate data. plant rooting depths and ground coverages were obtained from a vegetation characteristic data set. At each 0.5 degrees x 0.5 degrees grid cell where vegetation is present, unit available water capacity (cm water per cm soil) was estimated from the sand, clay, and organic content of each profile horizon, and integrated over horizon thickness. Summation of the integrated values over the lesser of profile depth and root depth produced an estimate of the plant-extractable water capacity of soil. The global average of the estimated plant-extractable water capacities of soil is 8 . 6 cm (Greenland, Antarctica and bare soil areas excluded). Estimates are less than 5, 10 and 15 cm-over approximately 30, 60, and 89 per cent of the area, respectively. Estimates reflect the combined effects of soil texture, soil organic content, and plant root depth or profile depth. The most influential and uncertain parameter is the depth over which the plant-extractable water capacity of soil is computed, which is usually limited by root depth. Soil texture exerts a lesser, but still substantial, influence. Organic content, except where concentrations are very high, has relatively little effect. C1 UNIV DELAWARE,DEPT GEOG,CTR CLIMAT RES,NEWARK,DE 19716. RP Dunne, KA (reprint author), US GEOL SURVEY,GEOPHYS FLUID DYNAM LAB,POB 308,RT 1 FORRESTAL CAMPUS,PRINCETON,NJ 08542, USA. NR 55 TC 75 Z9 78 U1 3 U2 22 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 AUG PY 1996 VL 16 IS 8 BP 841 EP 859 DI 10.1002/(SICI)1097-0088(199608)16:8<841::AID-JOC60>3.0.CO;2-8 PG 21 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA VF591 UT WOS:A1996VF59100001 ER PT J AU Schlangen, E Garboczi, EJ AF Schlangen, E Garboczi, EJ TI New method for simulating fracture using an elastically uniform random geometry lattice SO INTERNATIONAL JOURNAL OF ENGINEERING SCIENCE LA English DT Article ID CRACK-PROPAGATION; PARTICLE MODEL; COMPOSITES; AGGREGATE; BEHAVIOR; FRAMES AB This paper discusses 2D lattice models of beams for simulating the fracture of brittle materials. A simulation of an experiment on a concrete plate subjected to shear, in which two overlapping cracks occur, is used to study the effect of individual beam characteristics and different arrangements of the beams in the overall lattice. It was found that any regular orientation of the beams influences the resulting crack patterns. A method is developed to construct a lattice with a random geometry, but which can represent a homogeneous medium, that eliminates the influence of the beam orientation on a simulated crack pattern. Methods to implement a wide range of Poisson's ratios are also developed, and the use of the random lattice to study arbitrary microstructures is outlined. The crack patterns that are obtained with this lattice are in good agreement with the experimental results. Published by Elsevier Science Ltd C1 NIST,BLDG MAT DIV,GAITHERSBURG,MD 20899. DELFT UNIV TECHNOL,STEVIN LAB,NL-2600 GA DELFT,NETHERLANDS. RI Schlangen, Erik/A-3287-2009 NR 29 TC 91 Z9 94 U1 1 U2 10 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD, ENGLAND OX5 1GB SN 0020-7225 J9 INT J ENG SCI JI Int. J. Eng. Sci. PD AUG PY 1996 VL 34 IS 10 BP 1131 EP 1144 DI 10.1016/0020-7225(96)00019-5 PG 14 WC Engineering, Multidisciplinary SC Engineering GA VC769 UT WOS:A1996VC76900003 ER PT J AU Stunder, BJB AF Stunder, BJB TI An assessment of the quality of forecast trajectories SO JOURNAL OF APPLIED METEOROLOGY LA English DT Article ID PRECIPITATION CHEMISTRY; ATMOSPHERIC TRANSPORT; VOLCANIC ASH; MODEL; ACCURACY; SENSITIVITY AB Forecast and ''analysis'' (reference) trajectories were computed from six sites over North America at three altitudes (500, 1000, and 1500 m above ground) twice a day for a one-year period using Nested Grid Model wind fields. The reference meteorology was a series of short-term forecasts. Absolute error (distance between reference and forecast trajectory), relative error (absolute error divided by forecast trajectory travel distance), and the angle between the reference and forecast trajectory were also computed. The mean relative error for all the forecast trajectories for a travel time of 36 h is about 35%; the 90th percentile of the relative error is about 65%. The forecast is slightly biased to the left of the reference early in the forecast period. Absolute error and travel distance both are larger in winter than summer, so that the relative error is generally constant throughout the year. Differences in mean error among the three starting altitudes, among the six origin sites, and between the two origin times are insignificant when compared to the variation in errors for a collection of trajectories at a given origin. The forecast trajectories were objectively classified through a cluster analysis, which groups trajectories by direction and travel distance. For all clusters, by season, origin site, and altitude, differences between the minimum and maximum cluster-mean relative errors were about a factor of 2-3. Individual forecast trajectories composing clusters with the minimum relative error (about 20%) tended to originate within stronger, steady flow either ahead of or behind a cold front. Maximum relative error (about 45%) was associated with forecast trajectories originating in regions of generally slow wind fields such as under a high pressure system or near stationary or slowly moving fronts. RP Stunder, BJB (reprint author), NOAA,AIR RESOURCES LAB REAR,SSMC3,ROOM 3151,1315 E W HIGHWAY,SILVER SPRING,MD 20910, USA. RI Stunder, Barbara/C-3106-2016 NR 25 TC 63 Z9 69 U1 2 U2 8 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 AUG PY 1996 VL 35 IS 8 BP 1319 EP 1331 DI 10.1175/1520-0450(1996)035<1319:AAOTQO>2.0.CO;2 PG 13 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA VE128 UT WOS:A1996VE12800013 ER PT J AU Holle, RL Lopez, RE Arnold, LJ Endres, J AF Holle, RL Lopez, RE Arnold, LJ Endres, J TI Insured lightning-caused property damage in three western states SO JOURNAL OF APPLIED METEOROLOGY LA English DT Article ID UNITED-STATES; COLORADO; SUMMER AB Insurance claims resulting from lightning damage in Colorado, Utah, and Wyoming were analyzed during the period from 1987 to 1993. Most claims were from personal accounts, while some were commercial. Lightning damage in the three states resulted in an annual average of 6755 claims being filed. Most claims were from Colorado, and more than half were from the Denver metropolitan area. Over $7 million a year in lightning losses occurred in the three states for these types of insurance policies when a $150 deductible was included; most losses were in Colorado. The average value paid per claim was $916 for all three states and types of claims; commercial claims averaged $1369, and personal claims averaged $873. One lightning insurance claim was estimated to occur in the three-stare region for every 55 cloud-to-ground lightning flashes recorded by detection networks. Nearly all lightning claims were from May through September. The largest number of claims were from counties with the largest populations. However, the claim rate per population and the dollar loss per claim were not well related to county population. A rate of 4.7 claims per 10 000 people applied for Colorado, 1.4 for Utah, and 3.9 for Wyoming. Annual U.S. totals of 307 000 claims and $332 million in losses were extrapolated on the basis of population in the three stales. The dataset for Colorado, Utah, and Wyoming had 367 times as many claims as similarly insurable damage reports in the National Oceanic and Atmospheric Administration's Storm Data during the same years. This publication is widely used as the basis for lightning and other storm-related casualty and damage information. The results suggest that Storm Data greatly underestimates lightning damage. C1 STATE FARM FIRE & CASUALTY CO,DENVER,CO. STATE FARM FIRE & CASUALTY CO,GREELEY,CO. RP Holle, RL (reprint author), NOAA,NATL SEVERE STORMS LAB,1313 HALLEY CIRCLE,NORMAN,OK 73069, USA. NR 10 TC 14 Z9 14 U1 0 U2 0 PU AMER METEOROLOGICAL SOC PI BOSTON PA 45 BEACON ST, BOSTON, MA 02108-3693 SN 0894-8763 J9 J APPL METEOROL JI J. Appl. Meteorol. PD AUG PY 1996 VL 35 IS 8 BP 1344 EP 1351 DI 10.1175/1520-0450(1996)035<1344:ILCPDI>2.0.CO;2 PG 8 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA VE128 UT WOS:A1996VE12800015 ER PT J AU Chernykh, IV Eskridge, RE AF Chernykh, IV Eskridge, RE TI Determination of cloud amount and level from radiosonde soundings SO JOURNAL OF APPLIED METEOROLOGY LA English DT Article AB A method developed in the former Soviet Union for predicting cloud amounts is supplemented with a new method of determining the base and tops of clouds. Criteria for predicting a cloud layer are 0 less than or equal to T ''(z) and R ''(z) less than or equal to 0, where T '' is the second derivative of the vertical profile of temperature and R '' is the second derivative of the relative humidity. This test was found from an analyses of United States radiosonde data. Cloud amount (sky cover) is predicted from a relationship between cloud amount and dewpoint depression within the predicted cloud layer and the temperature at that level. This relationship is based on data from the former Soviet Union and data from the Indian Ocean and divides cloud amount into four categories: 0%-20%, 20%-60%, 60%-80%, and 80%-100% coverage. The new composite method is evaluated using data from several United States radiosonde stations within different climates. Evaluation data was selected to include only situations in which the observer (providing the ''truth'') could see only one cloud layer. Consequently, the evaluation is biased toward stratified cloud conditions. The method will provide cloud information that can be used in models of radiosonde sensors to adjusted temperature data. C1 NOAA,NATL ENVIRONM SATELLITE DATA & INFORMAT SERV,NATL CLIMAT DATA CTR,ASHEVILLE,NC 28801. RUSSIAN RES INST HYDROMETEOROL INFORMAT,OBNINSK,KALUGA,RUSSIA. NR 20 TC 44 Z9 52 U1 0 U2 3 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 AUG PY 1996 VL 35 IS 8 BP 1362 EP 1369 DI 10.1175/1520-0450(1996)035<1362:DOCAAL>2.0.CO;2 PG 8 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA VE128 UT WOS:A1996VE12800017 ER PT J AU King, MD Menzel, WP Grant, PS Myers, JS Arnold, GT Platnick, SE Gumley, LE Tsay, SC Moeller, CC Fitzgerald, M Brown, KS Osterwisch, FG AF King, MD Menzel, WP Grant, PS Myers, JS Arnold, GT Platnick, SE Gumley, LE Tsay, SC Moeller, CC Fitzgerald, M Brown, KS Osterwisch, FG TI Airborne scanning spectrometer for remote sensing of cloud, aerosol, water vapor, and surface properties SO JOURNAL OF ATMOSPHERIC AND OCEANIC TECHNOLOGY LA English DT Article ID MODIS; SCIENCE AB An airborne scanning spectrometer was developed for measuring reflected solar and emitted thermal radiation in 50 narrowband channels between 0.55 and 14.2 mu m. The instrument provides multispectral images of outgoing radiation for purposes of developing and validating algorithms for the remote sensing of cloud, aerosol, water vapor, and surface properties from space. The spectrometer scans a swath width of 37 km, perpendicular to the aircraft flight track, with a 2.5-mrad instantaneous field of view. Images are thereby produced with a spatial resolution of 50 m at nadir from a nominal aircraft altitude of 20 km. Nineteen of the spectral bands correspond closely to comparable bands on the Moderate Resolution Imaging Spectroradiometer (MODIS), a facility instrument being developed for the Earth Observing System to be launched in the late 1990s. This paper describes the optical, mechanical, electrical, and data acquisition system design of the MODIS Airborne Simulator and presents some early results obtained from measurements acquired aboard the National Aeronautics and Space Administration ER-2 aircraft that illustrate the performance and quality of the data produced by this instrument. C1 UNIV WISCONSIN,NOAA,NESDIS,MADISON,WI. NASA,AMES RES CTR,ATAC,MOFFETT FIELD,CA 94035. APPL RES CORP,GODDARD SPACE FLIGHT CTR,GREENBELT,MD. RES & DATA SYST CORP,GODDARD SPACE FLIGHT CTR,GREENBELT,MD. UNIV WISCONSIN,COOPERAT INST METEOROL SATELLITE STUDIES,MADISON,WI. DAEDALUS ENTERPRISES INC,ANN ARBOR,MI. RP King, MD (reprint author), NASA,GODDARD SPACE FLIGHT CTR,CODE 900,GREENBELT,MD 20771, USA. RI Menzel, W. Paul/B-8306-2011; King, Michael/C-7153-2011; Tsay, Si-Chee/J-1147-2014; Platnick, Steven/J-9982-2014 OI Menzel, W. Paul/0000-0001-5690-1201; King, Michael/0000-0003-2645-7298; Platnick, Steven/0000-0003-3964-3567 NR 23 TC 153 Z9 154 U1 0 U2 6 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 AUG PY 1996 VL 13 IS 4 BP 777 EP 794 DI 10.1175/1520-0426(1996)013<0777:ASSFRS>2.0.CO;2 PG 18 WC Engineering, Ocean; Meteorology & Atmospheric Sciences SC Engineering; Meteorology & Atmospheric Sciences GA UY962 UT WOS:A1996UY96200001 ER PT J AU Post, MJ AF Post, MJ TI A graphical technique for retrieving size distribution parameters from multiple measurements: Visualization and error analysis SO JOURNAL OF ATMOSPHERIC AND OCEANIC TECHNOLOGY LA English DT Article ID INFORMATION-CONTENT; LIDAR MEASUREMENTS; RESPECT AB A graphical method is presented for using a set of multiple measurements to retrieve size distribution parameters for multisized scatterers/absorbers suspended in a propagation medium. It permits one to visualize fundamental limitations of the measurement set and to quantify the effects of measurement errors on the accuracy of the retrievals. Multiple wavelength optical measurements of stratospheric aerosols illustrate that wide wavelength spacing and low measurement errors are required to retrieve lognormal size distribution parameters using either backscatter or extinction and that retrieval accuracy likely will not be high in practice. RP Post, MJ (reprint author), NOAA,ERL,ENVIRONM TECHNOL LAB,R-E-ET4,325 BROADWAY,BOULDER,CO 80303, USA. NR 11 TC 17 Z9 17 U1 0 U2 2 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 AUG PY 1996 VL 13 IS 4 BP 863 EP 873 DI 10.1175/1520-0426(1996)013<0863:AGTFRS>2.0.CO;2 PG 11 WC Engineering, Ocean; Meteorology & Atmospheric Sciences SC Engineering; Meteorology & Atmospheric Sciences GA UY962 UT WOS:A1996UY96200006 ER PT J AU Roux, F Marks, FD AF Roux, F Marks, FD TI Extended velocity track display (EVTD): An improved processing method for Doppler radar observations of tropical cyclones SO JOURNAL OF ATMOSPHERIC AND OCEANIC TECHNOLOGY LA English DT Article ID INNER CORE; HURRICANE; KINEMATICS; EVOLUTION AB The authors present an improved version of the velocity track display (VTD) method, proposed by Lee et al., to deduce the primary vortex circulation in hurricanes from airborne Doppler radar data obtained during straight-line legs through the storm center. VTD allows the derivation of one projection of the mean horizontal wind, the wavenumber 0, 1, and 2 components of the tangential wind and one projection of the radial wind, in a series of concentric rings centered on the storm circulation center. The extended VTD (EVTD) algorithm determines additional information through a combination of data collected during successive legs: the Cartesian components of the mean horizontal wind; the wavenumber 0, 1, and 2 components of the tangential wind; and the wavenumber 0 and 1 components of the radial wind. Application of EVTD to airborne Doppler data collected on 17 September 1989 in Hurricane Hugo is discussed. Comparisons between the EVTD-derived winds, the flight-level measurements, and winds deduced from ''pseudo-dual-Doppler'' analyses show qualitatively good agreement. These results reveal the asymmetric structure of the storm and show that it was in a deepening stage, with increasing tangential wind, inflow, and upward velocity. Further applications are finally discussed. C1 UNIV TOULOUSE 3,CNRS,UMR 5560,LAB AEROL,F-31062 TOULOUSE,FRANCE. NOAA,HURRICANE RES DIV,AOML,MIAMI,FL. RI Marks, Frank/A-5733-2011 OI Marks, Frank/0000-0003-0371-5514 NR 27 TC 30 Z9 34 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 AUG PY 1996 VL 13 IS 4 BP 875 EP 899 DI 10.1175/1520-0426(1996)013<0875:EVTDAI>2.0.CO;2 PG 25 WC Engineering, Ocean; Meteorology & Atmospheric Sciences SC Engineering; Meteorology & Atmospheric Sciences GA UY962 UT WOS:A1996UY96200007 ER PT J AU Hansen, DV Poulain, PM AF Hansen, DV Poulain, PM TI Quality control and interpolations of WOCE-TOGA drifter data SO JOURNAL OF ATMOSPHERIC AND OCEANIC TECHNOLOGY LA English DT Article ID EQUATORIAL PACIFIC; TROPICAL PACIFIC; VARIABILITY AB Satellite-tracked drifting buoy data are being collected by numerous investigators and agencies in several countries for the World Ocean Circulation Experiment-Tropical Oceans Global Atmosphere (WOCE-TOGA) Surface Velocity Program. By the end of the century, and thereafter, this global dataset will provide the best available climatology and chronology of the surface currents of the World Ocean. To expedite completion of research quality datasets for archival and dissemination, a data acquisition activity is being conducted at NOAA Atlantic Oceanographic and Meteorological Laboratory (AOML), Miami, Florida. At AOML, data from drifting buoys of cooperating operators are quality controlled and optimally interpolated to uniform 6-h interval trajectories for archival at the Marine Environmental Data Service (Canada). This report describes in detail the procedures used in preparing these data for the benefit of second- or third-party users, or future buoy operators who may wish to process data in a consistent way. Particular attention is given to provide quantitative estimates for uncertainty of interpolation. C1 UNIV MIAMI,COOPERAT INST MARINE & ATMOSPHER STUDIES,MIAMI,FL 33152. SACLANT UNDERSEA RES CTR,LA SPEZIA,ITALY. RP Hansen, DV (reprint author), NOAA,ENVIRONM RES LAB,AOML,4301 RICKENBACKER CAUSEWAY,MIAMI,FL 33149, USA. OI Poulain, Pierre-Marie/0000-0003-1342-8463 NR 16 TC 248 Z9 259 U1 0 U2 8 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 AUG PY 1996 VL 13 IS 4 BP 900 EP 909 DI 10.1175/1520-0426(1996)013<0900:QCAIOW>2.0.CO;2 PG 10 WC Engineering, Ocean; Meteorology & Atmospheric Sciences SC Engineering; Meteorology & Atmospheric Sciences GA UY962 UT WOS:A1996UY96200008 ER PT J AU Day, PN Jensen, JH Gordon, MS Webb, SP Stevens, WJ Krauss, M Garmer, D Basch, H Cohen, D AF Day, PN Jensen, JH Gordon, MS Webb, SP Stevens, WJ Krauss, M Garmer, D Basch, H Cohen, D TI An effective fragment method for modeling solvent effects in quantum mechanical calculations SO JOURNAL OF CHEMICAL PHYSICS LA English DT Article ID DISTRIBUTED MULTIPOLE ANALYSIS; MOLECULAR CHARGE-DISTRIBUTION; HYDROGEN-BONDING INTERACTIONS; COMPACT EFFECTIVE POTENTIALS; REACTION FIELD-THEORY; EXPONENT BASIS-SETS; GAUSSIAN-TYPE BASIS; AQUEOUS-SOLUTIONS; INTERMOLECULAR INTERACTIONS; ELECTROSTATIC POTENTIALS AB An effective fragment model is developed to treat solvent effects on chemical properties and reactions. The solvent, which might consist of discrete water molecules, protein, or other material, is treated explicitly using a model potential that incorporates electrostatics, polarization, and exchange repulsion effects. The solute, which one can most generally envision as including some number of solvent molecules as well, is treated in a fully ab initio manner, using an appropriate level of electronic structure theory. Ln addition to the fragment model itself, formulae are presented that permit the determination of analytic energy gradients and, therefore, numerically determined energy second derivatives (hessians) for the complete system. Initial tests of the model for the water dimer and water-formamide are in good agreement with fully ab initio calculations. (C) 1996 American Institute of Physics. C1 IOWA STATE UNIV SCI & TECHNOL,DEPT CHEM,AMES,IA 50011. NIST,CTR ADV RES BIOTECHNOL,ROCKVILLE,MD 20850. UNIV MARYLAND,INST BIOTECHNOL,ROCKVILLE,MD 20850. CUNY,MT SINAI MED CTR,DEPT PHYSIOL & BIOPHYS,NEW YORK,NY 10029. BAR ILAN UNIV,DEPT CHEM,IL-52100 RAMAT GAN,ISRAEL. RI Jensen, Jan/G-4338-2010 OI Jensen, Jan/0000-0002-1465-1010 NR 67 TC 437 Z9 440 U1 1 U2 25 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 AUG 1 PY 1996 VL 105 IS 5 BP 1968 EP 1986 DI 10.1063/1.472045 PG 19 WC Chemistry, Physical; Physics, Atomic, Molecular & Chemical SC Chemistry; Physics GA UZ525 UT WOS:A1996UZ52500023 ER PT J AU Buntin, SA AF Buntin, SA TI Hyperthermal H atom interactions with D/Si(100): Effects of incident H atom kinetic energy on the removal of adsorbed D SO JOURNAL OF CHEMICAL PHYSICS LA English DT Article ID SI(100) SURFACE; HYDROGEN DESORPTION; EXCHANGE-REACTIONS; SI(111) SURFACES; ABSTRACTION; ADSORPTION; DYNAMICS; SILICON; PHOTOLYSIS; HCL AB The interactions of H atoms having hyperthermal energies with a monodeuteride-terminated Si(100) surface are investigated. H atoms having mean kinetic energies of 1.0 and 2.9 eV are generated by 248 and 193 nm laser photolysis, respectively, of a pulsed, free-jet expansion of HI. Full characterization of the laser photolysis conditions allows the determination of the relative, as well as absolute, H atom exposures for these two kinetic energies. The depletion probability of adsorbed D per incident H atom is identical for species having incident kinetic energies of 1.0 and 2.9 eV and has an absolute value of 0.3 +/- 0.2. RP Buntin, SA (reprint author), NIST,SURFACE & MICROANAL SCI DIV,GAITHERSBURG,MD 20899, USA. NR 45 TC 39 Z9 39 U1 0 U2 1 PU AMER INST PHYSICS PI WOODBURY PA CIRCULATION FULFILLMENT DIV, 500 SUNNYSIDE BLVD, WOODBURY, NY 11797-2999 SN 0021-9606 J9 J CHEM PHYS JI J. Chem. Phys. PD AUG 1 PY 1996 VL 105 IS 5 BP 2066 EP 2075 DI 10.1063/1.472077 PG 10 WC Chemistry, Physical; Physics, Atomic, Molecular & Chemical SC Chemistry; Physics GA UZ525 UT WOS:A1996UZ52500033 ER PT J AU Poirier, GE Pylant, ED White, JM AF Poirier, GE Pylant, ED White, JM TI Crystalline structures of pristine and hydrated mercaptohexanol self-assembled monolayers an Au(111) SO JOURNAL OF CHEMICAL PHYSICS LA English DT Article ID SCANNING-TUNNELING-MICROSCOPY; ORGANIC-SURFACES; GOLD; THIOLS; SUPERLATTICE; ALKANETHIOLS; DISULFIDES; ADSORPTION; LIQUID; FILMS AB The crystalline structures of hydroxy-functionalized hexanethiol self-assembled monolayers on Au(111) were characterized using gas-phase transport of molecular precursors and an ultrahigh vacuum scanning tunneling microscope. In the pristine state the monolayer exhibits a commensurate lattice with an oblique primitive unit-cell of dimensions a = 3, b = root 13, alpha = a tan(2 root 3); a structure that is fundamentally different than the hexagonal lattice observed for methyl-terminated monolayers. Hydration of the monolayer results in conversion to a polymorphic phase. These results demonstrate the importance of end-group chemical bonding in the molecular packing of this widely studied class of materials. RP Poirier, GE (reprint author), NIST,GAITHERSBURG,MD 20899, USA. NR 21 TC 44 Z9 44 U1 2 U2 14 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 AUG 1 PY 1996 VL 105 IS 5 BP 2089 EP 2092 DI 10.1063/1.472078 PG 4 WC Chemistry, Physical; Physics, Atomic, Molecular & Chemical SC Chemistry; Physics GA UZ525 UT WOS:A1996UZ52500035 ER PT J AU Stensrud, DJ AF Stensrud, DJ TI Importance of low-level jets to climate: A review SO JOURNAL OF CLIMATE LA English DT Article ID MESOSCALE CONVECTIVE COMPLEXES; BOUNDARY-LAYER; UNITED-STATES; DIURNAL-VARIATIONS; GREAT-PLAINS; EAST ANTARCTICA; CIRCULATION; PRECIPITATION; SENSITIVITY; RADIATION AB Low-level jets (LLJs) occur frequently in many parts of the world. These low-level wind speed maxima are important for both the horizontal and vertical fluxes of temperature and moisture and have been found to be associated with the development and evolution of deep convection. Since deep convective activity produces a significant amount of upper-level cloudiness and is responsible for a large fraction of the warm season rainfall in the United States, the relationship between LLJs and deep convection suggests that LLJs are important contributors to regional climate. Results from a number of past studies are reviewed, and the potential for data from the Atmospheric Radiation Measurement program to augment our understanding of low-level jets is discussed. RP Stensrud, DJ (reprint author), NOAA,ENVIRONM RES LAB,NATL SEVERE STORMS LAB,1313 HALLEY CIRCLE,NORMAN,OK 73069, USA. NR 108 TC 159 Z9 167 U1 1 U2 19 PU AMER METEOROLOGICAL SOC PI BOSTON PA 45 BEACON ST, BOSTON, MA 02108-3693 SN 0894-8755 J9 J CLIMATE JI J. Clim. PD AUG PY 1996 VL 9 IS 8 BP 1698 EP 1711 DI 10.1175/1520-0442(1996)009<1698:IOLLJT>2.0.CO;2 PG 14 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA VG921 UT WOS:A1996VG92100003 ER PT J AU Thacker, WC Lewandowicz, R AF Thacker, WC Lewandowicz, R TI Climatic indices, principal components, and the Gauss-Markov theorem SO JOURNAL OF CLIMATE LA English DT Article ID CANONICAL CORRELATION-ANALYSIS; PREDICTION; PATTERNS; OCEAN AB If indices are to be used as the variables predicted by linear statistical models, it is important to be able to recover as much local information as possible from the values forecast for the indices. Here it is shown that the indices that encapsulate the most information about the local climatic state are determined by a generalized (two-matrix) eigenvalue problem that is equivalent to the usual (one-matrix) eigenvalue problem involving the sample correlation matrix. Thus, the best indices in the sense of providing the most location-specific information are familiar principal-component indices. Regarding the indices as predictors in linear statistical models similar to those routinely used for estimating meteorological fields from observations reveals the role of the Gauss-Markov theorem in EOF analyses. From this perspective each index can be characterized by two EOF-like maps: the first illustrating the linear combinations of the data used to define the index, and the second displaying the Gauss-Markov weights for the index to predict local variables, both of which are related to the eigenvectors of the sample correlation matrix. Other maps can be used to display information about sampling errors: one to characterize the uncertainty of the weights; another to display the skill with which the index accounts for the training data; and a third to show how well it explains independent data. Such maps are illustrated within the context of 43 years of North Atlantic seasonal sea surface temperature anomalies. The analysis presented here underlines two additional points. First, any linear combination of the indices would result in an equivalent model yielding exactly the same forecast. Consequently, it may be desirable to use indices that are easier to interpret physically. Second, when indices are regarded as being variables of a linear statistical model, the analysis of sampling error can be formulated in terms of the uncertainty of the Gauss-Markov weights inferred from a Limited training set rather than in terms of the sample-to-sample variability of eigenvalues and eigenvectors. C1 UNIV MIAMI,COOPERAT INST MARINE & ATMOSPHER STUDIES,MIAMI,FL 33152. RP Thacker, WC (reprint author), NOAA,ATLANTIC OCEANOG & METEOROL LAB,USDC,4301 RICKENBACKER CAUSEWAY,MIAMI,FL 33149, USA. RI Thacker, Carlisle/I-3813-2013 OI Thacker, Carlisle/0000-0002-9285-8826 NR 50 TC 15 Z9 15 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 AUG PY 1996 VL 9 IS 8 BP 1942 EP 1958 DI 10.1175/1520-0442(1996)009<1942:CIPCAT>2.0.CO;2 PG 17 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA VG921 UT WOS:A1996VG92100017 ER PT J AU Kim, JS Seiler, DG Lancaster, RA Reine, MB AF Kim, JS Seiler, DG Lancaster, RA Reine, MB TI Electrical characterization of very-narrow-gap bulk HgCdTe single crystals by variable magnetic field hall measurements SO JOURNAL OF ELECTRONIC MATERIALS LA English DT Article; Proceedings Paper CT 1995 US Workshop on the Physics and Chemistry of Mercury Cadmium Telluride and Other IR Materials CY OCT 10-12, 1995 CL BALTIMORE, MD DE bandgap-crossing; electron transport; hall measurements; HgCdTe; high electron mobility; very-narrow-gap semiconductors ID INTRINSIC CARRIER CONCENTRATION; MERCURY CADMIUM TELLURIDE; ENERGY-GAP; BAND-GAP; HG1-XCDXTE; TEMPERATURE; FILMS; SEMICONDUCTORS; DEPENDENCE AB Variable-magnetic-field Hall measurements (0 to 1.5 T) are performed on very narrow-gap bulk-grown Hg1-xCdxTe single crystals (0.165 less than or equal to x less than or equal to 0.2) at various temperatures (10 to 300K). The electron densities and mobilities are obtained within the one-carrier (electrons) approximation of the reduced-conductivity-tensor scheme. The present data together with the selected data set reported by other workers exhibit a pronounced peak when the electron mobility is plotted against the alloy composition x-value which has been predicted to be due to the effective-mass minimum at the bandgap-crossing (E(g) approximate to 0). The observed position (x approximate to 0.165), height (approximate to 4 x 10(2) m(2)/Vs), and width (approximate to 0.01 in x) of the mobility-peak can be explained by a simple simulation involving only ionized-impurity scattering. A lower bound of the effective mass is introduced as a fitting parameter to be consistent with the finiteness of the observed electron mobility and is found to be of the order of 10(-4) of the mass of a free electron. C1 LORAL INFRARED & IMAGING SYST,LEXINGTON,MA 02173. RP Kim, JS (reprint author), NIST,DIV SEMICOND ELECT,GAITHERSBURG,MD 20899, USA. NR 25 TC 3 Z9 3 U1 0 U2 3 PU MINERALS METALS MATERIALS SOC PI WARRENDALE PA 420 COMMONWEALTH DR, WARRENDALE, PA 15086 SN 0361-5235 J9 J ELECTRON MATER JI J. Electron. Mater. PD AUG PY 1996 VL 25 IS 8 BP 1215 EP 1220 DI 10.1007/BF02655011 PG 6 WC Engineering, Electrical & Electronic; Materials Science, Multidisciplinary; Physics, Applied SC Engineering; Materials Science; Physics GA VC702 UT WOS:A1996VC70200015 ER PT J AU Jones, RK AF Jones, RK TI Method for estimating boiling temperatures of crude oils SO JOURNAL OF ENVIRONMENTAL ENGINEERING-ASCE LA English DT Article AB Evaporation is often the dominant mechanism for mass loss during the first few days following an oil spill. The initial boiling point of the oil and the rate at which the boiling point changes as the oil evaporates are needed to initialize some computer models used in spill response. The lack of available boiling point data often limits the usefulness of these models in actual emergency situations. A new computational method was developed to estimate the temperature at which a crude oil boils as a function of the fraction evaporated using only standard distillation data, which are commonly available. This method employs established thermodynamic rules and approximations, and was designed to be used with automated spill-response models. Comparisons with measurements show a strong correlation between results obtained with this method and measured values. RP Jones, RK (reprint author), NOAA,7600 SAND POINT WAY NE,SEATTLE,WA 98115, USA. NR 8 TC 1 Z9 1 U1 0 U2 1 PU ASCE-AMER SOC CIVIL ENG PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017-2398 SN 0733-9372 J9 J ENVIRON ENG-ASCE JI J. Environ. Eng.-ASCE PD AUG PY 1996 VL 122 IS 8 BP 761 EP 763 DI 10.1061/(ASCE)0733-9372(1996)122:8(761) PG 3 WC Engineering, Environmental; Engineering, Civil; Environmental Sciences SC Engineering; Environmental Sciences & Ecology GA UX941 UT WOS:A1996UX94100013 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 SOLAR TERR PHYS A,BOULDER,CO 80302, 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 AUG 1 PY 1996 VL 101 IS A8 BP 17423 EP 17424 DI 10.1029/96JA02054 PG 2 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA VB700 UT WOS:A1996VB70000033 ER PT J AU Stoudt, MR Fink, JL Ricker, RE AF Stoudt, MR Fink, JL Ricker, RE TI Evaluation of the propensity of replacements for halon 1301 to induce stress-corrosion cracking in alloys used in aircraft fire-suppressant storage and distribution systems SO JOURNAL OF MATERIALS ENGINEERING AND PERFORMANCE LA English DT Article DE bicarbonate cracking; environmentally assisted fracture; halon alternatives; slow strain rate (SSR); stress corrosion cracking (SCC) AB The fire-suppressant agents halon 1301 and halon 1211 have both been determined to possess sufficient ozone layer depletion potential to warrant strict limitations on their production and use, The service conditions aboard jet aircraft subject engine fire-suppressant storage vessels to the agents for long durations at elevated temperatures and pressures. Stress-corrosion cracking (SCC) of the materials of the vessel wall and/or rupture disk assembly (agent release valve) could prevent proper operation, Therefore, the compatibility of potential replacements with the materials used in the fire-suppressant storage and distribution systems is a serious concern. An evaluation of the relative SCC propensity of 12 halon replacement candidates was conducted to enable the selection of three of these compounds for further study, The slow-strain-rate (SSR) tensile test was selected, and a statistical method was developed for ranking the relative susceptibility of each alloy in each agent from the SSR test results, The results revealed that most agents had little tendency to cause SCC, but that some agent/alloy combinations were undesirable. The statistical technique allowed relative comparison, ranking, and combination of these results with other types of tests for the identification of three agents suitable for development and evaluation as aircraft fire suppressants. RP Stoudt, MR (reprint author), NIST,MAT SCI & ENGN LAB,GAITHERSBURG,MD 20899, USA. RI Ricker, Richard/H-4880-2011 OI Ricker, Richard/0000-0002-2871-4908 NR 17 TC 1 Z9 2 U1 0 U2 0 PU ASM INTERNATIONAL PI MATERIALS PARK PA SUBSCRIPTIONS SPECIALIST CUSTOMER SERVICE, MATERIALS PARK, OH 44073-0002 SN 1059-9495 J9 J MATER ENG PERFORM JI J. Mater. Eng. Perform. PD AUG PY 1996 VL 5 IS 4 BP 507 EP 515 DI 10.1007/BF02648848 PG 9 WC Materials Science, Multidisciplinary SC Materials Science GA UZ730 UT WOS:A1996UZ73000010 ER PT J AU Edgar, JH Carosella, CA Eddy, CR Smith, DT AF Edgar, JH Carosella, CA Eddy, CR Smith, DT TI Effect of beam voltage on the properties of aluminium nitride prepared by ion beam assisted deposition SO JOURNAL OF MATERIALS SCIENCE-MATERIALS IN ELECTRONICS LA English DT Article ID ALN THIN-FILMS; THERMAL-CONDUCTIVITY; EPITAXIAL-GROWTH; PRESSURE; AIN; SI(111); STRESS AB The effects of nitrogen-beam voltage on the structure, stress, energy band gap and hard ness of AIN thin films deposited on Si (111), Si (100) and sapphire (0001) by ion beam assisted deposition (IBAD) are reported. As the nitrogen-beam voltage was increased from 50 to 200 V, the stress and disorder in the AIN films increased as determined by X-ray diffraction, FTIR and Raman spectroscopy. The preferred orientation of the film's c-axis changed from completely normal to the film at 100 V, to a mixture of normal and in the plane of the film at 200 V. For AIN films deposited under the same conditions, the films were more highly oriented on sapphire (0001) than in Si (111). The hardness of the films increased from 18.2 to 23.7 GPa with the nitrogen-beam voltage, and possible reasons for this change in hardness are considered. C1 NIST,DIV CERAM,GAITHERSBURG,MD 20899. RP Edgar, JH (reprint author), USN,RES LAB,CODE 6671,WASHINGTON,DC 20375, USA. RI Smith, Douglas/I-4403-2016 OI Smith, Douglas/0000-0002-9358-3449 NR 30 TC 37 Z9 37 U1 0 U2 2 PU CHAPMAN HALL LTD PI LONDON PA 2-6 BOUNDARY ROW, LONDON, ENGLAND SE1 8HN SN 0957-4522 J9 J MATER SCI-MATER EL JI J. Mater. Sci.-Mater. Electron. PD AUG PY 1996 VL 7 IS 4 BP 247 EP 253 PG 7 WC Engineering, Electrical & Electronic; Materials Science, Multidisciplinary; Physics, Applied; Physics, Condensed Matter SC Engineering; Materials Science; Physics GA VB329 UT WOS:A1996VB32900001 ER PT J AU Kelton, KF Narayan, KL Levine, LE Cull, TC Ray, CS AF Kelton, KF Narayan, KL Levine, LE Cull, TC Ray, CS TI Computer modeling of non-isothermal crystallization SO JOURNAL OF NON-CRYSTALLINE SOLIDS LA English DT Article ID GLASS-FORMING LIQUIDS; TRANSFORMATION KINETICS; NONISOTHERMAL CRYSTALLIZATION; TRANSIENT NUCLEATION; CRYSTAL NUCLEATION; LITHIUM DISILICATE; THERMAL-ANALYSIS; SILICA GLASSES; SYSTEMS; GROWTH AB A realistic computer model for simulating isothermal and non-isothermal phase transformations proceeding by homogeneous and heterogeneous nucleation and interface-limited growth is presented. A new treatment for particle size effects on the crystallization kinetics is developed and is incorporated into the numerical model. Time-dependent nucleation rates, size-dependent growth rates and surface crystallization are also included. Model predictions are compared with experimental measurements of DSC/DTA peak parameters for the crystallization of lithium disilicate glass as a function of particle size, Pt doping levels, and water content. The quantitative agreement that is demonstrated indicates that the numerical model can be used to extract key kinetic data from easily obtained calorimetric data. The model can also be used to probe nucleation and growth behavior in regimes that are otherwise inaccessible. Based on a fit to data, an earlier prediction that the time-dependent nucleation rare in a DSC/DTA scan can rise above the steady-state value at a temperature higher than the peak in the steady-state rate is demonstrated. C1 NIST,GAITHERSBURG,MD 20899. UNIV MISSOURI,GRAD CTR MAT RES,ROLLA,MO 65401. RP Kelton, KF (reprint author), WASHINGTON UNIV,DEPT PHYS,ST LOUIS,MO 63130, USA. NR 32 TC 41 Z9 41 U1 2 U2 15 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0022-3093 J9 J NON-CRYST SOLIDS JI J. Non-Cryst. Solids PD AUG PY 1996 VL 204 IS 1 BP 13 EP 31 DI 10.1016/0022-3093(96)00402-4 PG 19 WC Materials Science, Ceramics; Materials Science, Multidisciplinary SC Materials Science GA VQ727 UT WOS:A1996VQ72700005 ER PT J AU Nesbitt, DJ Field, RW AF Nesbitt, DJ Field, RW TI Vibrational energy flow in highly excited molecules: Role of intramolecular vibrational redistribution SO JOURNAL OF PHYSICAL CHEMISTRY LA English DT Review ID RESOLUTION INFRARED-SPECTROSCOPY; CH STRETCH OVERTONE; QUANTUM BEAT SPECTROSCOPY; JET-COOLED ALKYLBENZENES; METHYL INTERNAL-ROTATION; N-H STRETCH; DOUBLE-RESONANCE; DISPERSED FLUORESCENCE; POLYATOMIC-MOLECULES; P-FLUOROTOLUENE AB A pedagogical overview of intramolecular vibrational redistribution (IVR) phenomena in vibrationally excited molecules is presented. In the interest of focus and simplicity, the topics covered deal primarily with IVR in the ground electronic state, relying on examples from the literature to illustrate key points. The experimental topics discussed attempt to sample systematically three different energy regimes on the full potential surface corresponding to (i) ''low'', e.g., moderate- to high-resolution vibrational spectroscopies, (ii) ''intermediate'', e.g., stimulated emission pumping and high overtone spectroscopies, and (iii) ''high'', e.g., photofragment/ predissociation dynamical spectroscopies. The interplay between experiment and theory is highlighted here because it has facilitated enormous advances in the field over the past decade. C1 NATL INST STAND & TECHNOL, JILA, QUANTUM PHYS DIV, BOULDER, CO 80309 USA. MIT, DEPT CHEM, CAMBRIDGE, MA 02139 USA. RP UNIV COLORADO, DEPT CHEM & BIOCHEM, BOULDER, CO 80309 USA. NR 196 TC 500 Z9 500 U1 16 U2 100 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 AUG 1 PY 1996 VL 100 IS 31 BP 12735 EP 12756 DI 10.1021/jp960698w PG 22 WC Chemistry, Physical SC Chemistry GA VA595 UT WOS:A1996VA59500006 ER PT J AU Mehta, VR Kumar, S Polk, MB Vanderhart, DL Arnold, FE Dang, TD AF Mehta, VR Kumar, S Polk, MB Vanderhart, DL Arnold, FE Dang, TD TI On the evidence of crosslinking in methyl pendent PBZT fiber SO JOURNAL OF POLYMER SCIENCE PART B-POLYMER PHYSICS LA English DT Article DE crosslinking; poly(p-phenylene benzobis thiazole); PBZT; methyl pendant PBZT; C-13 solid state NMR ID NUCLEAR MAGNETIC-RESONANCE; GLASSY-POLYMERS; C-13 NMR; RESOLUTION AB In order to influence the compressive strength of the rigid rod polymeric fibers, methyl pendent poly (p-phenylene benzobisthiazole) fibers have been heat treated in the 400 to 550 degrees C temperature range in air and in nitrogen for varying times to achieve intermolecular crosslinking. These fibers have been examined using Fourier transform infrared (FTIR) spectroscopy, C-13 solid-state nuclear magnetic resonance (NMR) swelling behavior, and scanning electron microscopy. C-13 NMR has also been carried out on solutions of as-spun fibers. Fibers heat-treated at 400 degrees C, both in nitrogen and in air, up to heat-treatment times of 60 min are insoluble in 99% chlorosulfonic acid, however no direct evidence of crosslinking has been obtained for these fibers using spectroscopic techniques, suggesting that in these fibers the degree of crosslinking must be very low. Evidence that methyl groups are precursors to certain crosslinks was first seen via a weak methylene resonance in C-13 solid-state NMR, corresponding to about 2% of the original methyl intensity, in a sample heat-treated at 450 degrees C in air. Fibers heat-treated in nitrogen at 550 degrees C for 10 minutes do not exhibit any swelling in chlorosulfonic acid, are brittle, have lost most methyl groups; however, some CH2 groups form. In this fiber, the carbon intensity for the CH2 group in the C-13 solid-state NMR is 18% of the intensity for the CH3 group in the as-spun fiber. The fibers heat-treated at 400 and 450 degrees C show a fibrillar morphology, while the fibrillar morphology is not observed in the fibers heat-treated at 550 degrees C in nitrogen for 10 min. Based on this work, it is our judgment that if heat treatment of this material is to improve compressive strength, the heat treatment protocol of time and temperature will probably be critical and the highest temperatures of exposure will probably lie in the 450 to 550 degrees C range. (C) 1996 John Wiley & Sons, Inc. C1 GEORGIA INST TECHNOL,SCH TEXT & FIBER ENGN,ATLANTA,GA 30332. NATL INST STAND & TECHNOL,DIV POLYMERS,GAITHERSBURG,MD 20899. UNIV DAYTON,RES INST,DAYTON,OH 45469. MLBP,WL,WRIGHT PATTERSON AFB,OH 45433. RI Kumar, Satish/F-7308-2011 NR 24 TC 14 Z9 14 U1 0 U2 1 PU JOHN WILEY & SONS INC PI NEW YORK PA 605 THIRD AVE, NEW YORK, NY 10158-0012 SN 0887-6266 J9 J POLYM SCI POL PHYS JI J. Polym. Sci. Pt. B-Polym. Phys. PD AUG PY 1996 VL 34 IS 11 BP 1881 EP 1891 PG 11 WC Polymer Science SC Polymer Science GA UX702 UT WOS:A1996UX70200009 ER PT J AU Park, K Nolt, IG Steele, TC Zink, LR Evenson, KM Chance, KV Murray, AG AF Park, K Nolt, IG Steele, TC Zink, LR Evenson, KM Chance, KV Murray, AG TI Pressure broadening of the 50.873 and 83.469 cm(-1) molecular oxygen lines SO JOURNAL OF QUANTITATIVE SPECTROSCOPY & RADIATIVE TRANSFER LA English DT Article ID N2; O2 AB We report pressure broadening measurements of the 50.873 and 83.469 cm(-1) molecular oxygen lines at 293 K. Air broadening coefficients are determined with 13% accuracy. Published by Elsevier Science Ltd. C1 NASA,LANGLEY RES CTR,HAMPTON,VA 23681. NATL INST STAND & TECHNOL,BOULDER,CO 80303. HARVARD SMITHSONIAN CTR ASTROPHYS,CAMBRIDGE,MA 02138. UNIV LONDON QUEEN MARY & WESTFIELD COLL,LONDON E1 4NS,ENGLAND. RP Park, K (reprint author), UNIV OREGON,DEPT PHYS,EUGENE,OR 97403, USA. OI Chance, Kelly/0000-0002-7339-7577 NR 8 TC 10 Z9 10 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 AUG PY 1996 VL 56 IS 2 BP 315 EP 316 DI 10.1016/0022-4073(96)00026-X PG 2 WC Optics; Spectroscopy SC Optics; Spectroscopy GA VD019 UT WOS:A1996VD01900013 ER PT J AU Tepesch, PD Kohan, AE Garbulsky, GD Ceder, G Coley, C Stokes, HT Boyer, LL Mehl, MJ Burton, BP Cho, KJ Joannopoulos, J AF Tepesch, PD Kohan, AE Garbulsky, GD Ceder, G Coley, C Stokes, HT Boyer, LL Mehl, MJ Burton, BP Cho, KJ Joannopoulos, J TI A model to compute phase diagrams in oxides with empirical or first-principles energy methods and application to the solubility limits in the CaO-MgO system SO JOURNAL OF THE AMERICAN CERAMIC SOCIETY LA English DT Article ID ELECTRONIC-STRUCTURE; MOLECULAR-DYNAMICS; IONIC SYSTEMS; SIMULATIONS; BINARY; STATES AB The CaO-MgO system is used as a prototype system to evaluate the accuracy of several energy and entropy approximations for predicting solid-state phase diagrams in ionic materials. Configurational disorder between the cations is parameterized with the cluster expansion technique. The vibrational contribution to the free energy is incorporated with a harmonic model that accounts for the dependence of the vibrational density of states on the cation configuration. The CaO-MgO phase diagram can be predicted very accurately with quantum mechanical energy methods, without the use of any adjustable parameters. Published empirical potential parameters for the CaO-MgO system reproduce the qualitative features of the phase diagram but significantly underestimate the solubility limits. Parameters that reasonably reproduce the quantum mechanical results are presented. C1 USN,RES LAB,COMPLEX SYST THEORY BRANCH,WASHINGTON,DC 20375. NATL INST STAND & TECHNOL,GAITHERSBURG,MD 20899. MIT,DEPT PHYS,CAMBRIDGE,MA 02139. RP Tepesch, PD (reprint author), MIT,DEPT MAT SCI & ENGN,CAMBRIDGE,MA 02139, USA. RI Mehl, Michael/H-8814-2016 NR 31 TC 53 Z9 53 U1 2 U2 13 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 AUG PY 1996 VL 79 IS 8 BP 2033 EP 2040 DI 10.1111/j.1151-2916.1996.tb08934.x PG 8 WC Materials Science, Ceramics SC Materials Science GA VC613 UT WOS:A1996VC61300006 ER PT J AU Lee, SY Anderson, JL AF Lee, SY Anderson, JL TI A simulation of atmospheric storm tracks with a forced barotropic model SO JOURNAL OF THE ATMOSPHERIC SCIENCES LA English DT Article ID ROSSBY-WAVE PROPAGATION; VARYING FLOW; CIRCULATION; INSTABILITY; ORGANIZATION; ANOMALIES AB A forced, nonlinear barotropic model on the sphere is shown to simulate some of the structure of the observed Northern Hemisphere midlatitude storm tracks with reasonable accuracy. For the parameter range chosen, the model has no unstable modes with significant amplitude in the storm track regions; however, several decaying modes with structures similar to the storm track are discovered. The model's midlatitude storm tracks also coincide with the location of a waveguide that is obtained by assuming that the horizontal variation of the time-mean flow is small compared with the scale of the transient eddies. Since the model is able to mimic the behavior of the observed storm tracks without any baroclinic dynamics, it is argued that the barotropic waveguide effects of the rime-mean background flow acting on individual eddies are partially responsible for the observed storm track structure. C1 PRINCETON UNIV,NOAA,GEOPHYS FLUID DYNAM LAB,PRINCETON,NJ. RP Lee, SY (reprint author), PENN STATE UNIV,DEPT METEOROL,503 WALKER BLDG,UNIVERSITY PK,PA 16802, USA. NR 23 TC 3 Z9 3 U1 0 U2 1 PU AMER METEOROLOGICAL SOC PI BOSTON PA 45 BEACON ST, BOSTON, MA 02108-3693 SN 0022-4928 J9 J ATMOS SCI JI J. Atmos. Sci. PD AUG 1 PY 1996 VL 53 IS 15 BP 2113 EP 2128 DI 10.1175/1520-0469(1996)053<2113:ASOAST>2.0.CO;2 PG 16 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA VD217 UT WOS:A1996VD21700001 ER PT J AU Wu, CC Kurihara, Y AF Wu, CC Kurihara, Y TI A numerical study of the feedback mechanisms of hurricane-environment interaction on hurricane movement from the potential vorticity perspective SO JOURNAL OF THE ATMOSPHERIC SCIENCES LA English DT Article ID TROPICAL CYCLONE MOTION; FLOW ASYMMETRIES; GLORIA 1985; MESH MODEL; VORTEX; SCHEME; BOUNDARY; IMPROVEMENTS; DIAGNOSTICS; INTENSITY AB The interaction between a hurricane and its environment is studied by analyzing the generation and influence of potential vorticity (PV) from the Geophysical Fluid Dynamics Laboratory hurricane model analysis system. Two sets of numerical experiments are performed: one with and the other without a bogused hurricane vortex in the initial time, for cases of Hurricanes Bob (1991), Gilbert (1988), and Andrew (1992). The PV budget analysis of Bob shows that the condensational heating within the vortex redistributes the PV, causing a PV sink in the upper part of the vortex and a PV source in the lower part. This tendency is compensated for largely, but nor entirely, by the upward transport of high-PV air from the lower levels to the upper levels. The net effect contributes to the increase of the negative upper-level PV anomaly during the vortex intensification period. This result indicates that the diabatic heating effect plays a crucial role in the evolution of the PV field in hurricanes. It also suggests the importance of accurate representation of the heating profile in hurricane models. It is shown that the negative upper-level PV anomaly is spread out by the upper-level outflow and the large-scale background flow. The impact of the spread of the negative upper PV anomaly to the storm is quantitatively evaluated by computing the nonlinear balanced flow associated with the PV perturbation. Notable contribution to the steering of the storm from the upper-level PV anomaly is found. The result supports the theory advanced by Wu and Emanuel concerning the effect of the upper negative PV anomaly on hurricane motion. This study also indicates the need of enhanced observation and accurate analysis and prediction in the upper troposphere in order to improve hurricane track forecasting. C1 PRINCETON UNIV,NOAA,GEOPHYS FLUID DYNAM LAB,PRINCETON,NJ 08542. RP Wu, CC (reprint author), NATL TAIWAN UNIV,DEPT ATMOSPHER SCI,LN 144,SEC 4,KEELUNG RD,TAIPEI 10772,TAIWAN. OI Wu, Chun-Chieh/0000-0002-3612-4537 NR 32 TC 43 Z9 49 U1 0 U2 5 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 AUG 1 PY 1996 VL 53 IS 15 BP 2264 EP 2282 DI 10.1175/1520-0469(1996)053<2264:ANSOTF>2.0.CO;2 PG 19 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA VD217 UT WOS:A1996VD21700009 ER PT J AU Vasilev, VV Velichansky, VL Gorodetsky, ML Ilchenko, VS Hollberg, L Yarovitsky, AV AF Vasilev, VV Velichansky, VL Gorodetsky, ML Ilchenko, VS Hollberg, L Yarovitsky, AV TI High-coherence diode laser with optical feedback via a microcavity with 'whispering gallery' modes SO KVANTOVAYA ELEKTRONIKA LA Russian DT Article ID LINE AB Narrowing of the linewidth of a diode laser was achieved by an external high-Q microcavity, which was a fused silica sphere 370 mu m in diameter. Coupling of the radiation in and out, and matching to a 'whispering gallery' mode of this sphere, were ensured by the method of frustrated total internal reflection. Optical feedback was provided by the Rayleigh scattering. The width of the beat-note spectra of the investigated and reference lasers did not exceed 100 kHz. C1 MOSCOW MV LOMONOSOV STATE UNIV,MOSCOW,RUSSIA. NATL INST STAND & TECHNOL,BOULDER,CO. RP Vasilev, VV (reprint author), PN LEBEDEV PHYS INST,LENINSKY PROSPECT 53,MOSCOW 117924,RUSSIA. RI Gorodetsky, Michael/C-5938-2008; Velichansky, Vladimir/M-4861-2015 OI Gorodetsky, Michael/0000-0002-5159-2742; NR 7 TC 4 Z9 4 U1 0 U2 1 PU LEBEDEV PHYSICAL INST KVANTOVAYA ELEKTRONIKA JOURNAL PI MOSCOW GSP-1 PA LENINSKII PROSPEKT 53, 117924 MOSCOW GSP-1, RUSSIA SN 0368-7147 J9 KVANTOVAYA ELEKTRON+ JI Kvantovaya Elektron. PD AUG PY 1996 VL 23 IS 8 BP 675 EP 676 PG 2 WC Engineering, Electrical & Electronic; Physics, Applied SC Engineering; Physics GA VH928 UT WOS:A1996VH92800001 ER PT J AU Hinckley, S Hermann, AJ Megrey, BA AF Hinckley, S Hermann, AJ Megrey, BA TI Development of a spatially explicit, individual-based model of marine fish early life history SO MARINE ECOLOGY PROGRESS SERIES LA English DT Article DE biophysical model; recruitment; walleye pollock; fisheries oceanography ID POLLOCK THERAGRA-CHALCOGRAMMA; CAPELIN MALLOTUS-VILLOSUS; LARVAL WALLEYE POLLOCK; HERRING CLUPEA-HARENGUS; GULF-OF-ALASKA; SHELIKOF STRAIT; VERTICAL-DISTRIBUTION; EMBRYONIC-DEVELOPMENT; INGESTION RATES; GROWTH AB A growing body of evidence suggests that survival of the planktonic early life stages of marine fish varies spatially, often in concordance with mesoscale and larger circulation patterns and with spatial variation in biotic and abiotic factors. Environmental variation experienced by individuals may contribute to variance within the population. Detailed spatial information about life histories cannot be obtained however, by simply subjecting individuals to identical time series of environmental variates, or adding random noise to the mean values of those variates. In this paper, we present a numerical biophysical model to address this problem. The model combines a 3-dimensional hydrodynamic model with a probabilistic, life-stage model of young fish. The oceanographic model is an eddy resolving, semi-spectral primitive equation model (SPEM) adapted for Shelikof Strait and the western Gulf of Alaska, USA. The biological component is an individual-based model (IBM) which follows each fish through its first 3 mo of life. The 2 models are coupled via a float-tracking algorithm, which advects each fish through the model grid based on the time-varying velocity field derived from the SPEM model, and returns information to the IBM on any physical variables of interest (e.g. temperature and salinity) at the individual's new location. These variables are used to drive biological processes in the IBM. Simulation 1 demonstrates how a probabilistic IBM using Lagrangian temperature information derived from float tracking can yield significantly different biological results than the same model with constant temperature, or a model where all individuals are subjected to identically increasing time series of temperature. In Simulation 2 we compare the float tracks and growth of individuals using a scenario of constant depth for each life stage versus algorithms that include mechanisms producing variable depth. These mechanisms differ for each life stage (e.g. changes in depth due to development of eggs, or diel migration of feeding larvae). This simulation shows that inclusion of specific mechanisms which determine depth of individual eggs or larvae at particular periods of their development are important in determining the direction of horizontal advection, and the history of exposure to environmental variables for each individual. Simulation 3 compares modeled distributions of the early life stages with distributions derived from field surveys. C1 UNIV WASHINGTON, JOINT INST STUDY ATMOSPHERE & OCEANS, SEATTLE, WA 98195 USA. RP Hinckley, S (reprint author), NOAA, NATL MARINE FISHERIES SERV, ALASKA FISHERIES SCI CTR, 7600 SAND POINT WAY NE, SEATTLE, WA 98115 USA. NR 69 TC 91 Z9 95 U1 0 U2 10 PU INTER-RESEARCH PI OLDENDORF LUHE PA NORDBUNTE 23, D-21385 OLDENDORF LUHE, GERMANY SN 0171-8630 J9 MAR ECOL PROG SER JI Mar. Ecol.-Prog. Ser. PD AUG PY 1996 VL 139 IS 1-3 BP 47 EP 68 DI 10.3354/meps139047 PG 22 WC Ecology; Marine & Freshwater Biology; Oceanography SC Environmental Sciences & Ecology; Marine & Freshwater Biology; Oceanography GA VG034 UT WOS:A1996VG03400005 ER PT J AU Schramm, RE Szelazek, J VanClark, A AF Schramm, RE Szelazek, J VanClark, A TI Ultrasonic measurement of residual stress in the rims of inductively heated railroad wheels SO MATERIALS EVALUATION LA English DT Article AB Residual stresses in railroad wheels may change from compressive to tensile during use, a potentially hazardous condition that could cause wheel failure. Until recently, LIS regulation called for the measurement of a discoloration, revealing past heating that sometimes lends to unsafe stress. Quantitative measurement by ultrasonic methods is an attractive alternative. Stress causes small changes in sound velocity. This report covers an extensive series of ultrasonic tests on ten cast steel wheels; two were as manufactured, while the others received induction heating to generate stresses similar to in service wheels. Measurements with two different ultrasonic instruments gave comparable results. Furthermore, ultrasonic measurements correlated well with a simple destructive evaluation. This suggests a useful method for inspection and maintenance. RP Schramm, RE (reprint author), NATL INST STAND & TECHNOL,DIV MAT RELIABIL,325 BROADWAY,BOULDER,CO 80303, USA. NR 20 TC 1 Z9 1 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 AUG PY 1996 VL 54 IS 8 BP 929 EP 934 PG 6 WC Materials Science, Characterization & Testing SC Materials Science GA VB994 UT WOS:A1996VB99400006 ER PT J AU Miller, LJ LeMone, MA Blumen, W Grossman, RL Gamage, N Zamora, RJ AF Miller, LJ LeMone, MA Blumen, W Grossman, RL Gamage, N Zamora, RJ TI The low-level structure and evolution of a dry arctic front over the central United States .1. Mesoscale observations SO MONTHLY WEATHER REVIEW LA English DT Article ID PLANETARY BOUNDARY-LAYER; DIFFERENTIAL CLOUD COVER; DUAL-DOPPLER ANALYSIS; COLD-FRONT; CONVECTIVE SYSTEMS; RADAR ECHOES; PRECIPITATION; TEMPERATURE; DYNAMICS; MODEL AB Observations taken over the period 8-10 March 1992 during the Storm-scale Operational and Research Meteorology Fronts Experiment Systems Test in the central United States are used to document the detailed low-level structure and evolution of a shallow, dry arctic front. The front was characterized by cloudy skies to it north side and clear skies to its south side. It was essentially two-dimensional in the zone of intense observations. There was a significant diurnal cycle in the magnitude of the potential temperature gradient across both the subsynoptic and mesoscale frontal zones, but imposed upon an underlying, more gradual, increase over the three days. On the warm (cloudless) side, the temperature increased and decreased in response to the diurnal heating cycle, while on the cold (cloudy) side the shape of the temperature decrease from its warm-side value (first dropping rapidly and then slowly in an exponential-like manner) remained fairly steady. The authors attribute the strong diurnal variation in potential temperature gradient mostly to the effects of differential diabatic heating across the front due to differential cloud cover. The front is described in terms of three scales: 1) a broad, subsynoptic frontal zone (similar to 250-300 km wide) of modest temperature and wind gradients; 2) a narrower mesoscale zone (similar to 15-20 km wide) with much larger gradients; and 3) a microscale zone of near-zero-order discontinuity (less than or equal to 1-2 km wide). There was some narrowing (less than or similar to 50 km) of the subsynoptic frontal zone, but the authors found no evidence for any significant contraction of this zone down to much smaller mesoscale sizes. In response to the differential diabatic heating, the strongest evolution occurred in the micro-mesoscale zone, where dual-Doppler radar and aircraft measurements revealed the development of a density-current-like structure in and behind the leading edge of cold air. Here the steepest gradients developed shortly after sunrise and then increased by an order of magnitude during the day, with leading-edge vorticity, divergence,and temperature gradients reaching maximum values of 10(-2) s(-1) and 8 K km(-1). A narrow updraft, marked by cumulus clouds, grew in intensity above the leading edge through the day to a maximum of 5-8 m s(-1). Stratus clouds lay in the cold air, their leading edge receding by noon to 10-20 km behind the cumulus line. C1 UNIV COLORADO,DEPT ASTROPHYS PLANETARY & ATMOSPHER SCI,BOULDER,CO. UNIV COLORADO,PROGRAM ATMOSPHER & OCEAN SCI,BOULDER,CO 80307. UNIV CORP ATMOSPHER RES,OFF FIELD PROJECT SUPPORT,BOULDER,CO. NOAA,ERL,BOULDER,CO 80303. RP Miller, LJ (reprint author), NATL CTR ATMOSPHER RES,POB 3000,BOULDER,CO 80307, USA. NR 59 TC 19 Z9 19 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 AUG PY 1996 VL 124 IS 8 BP 1648 EP 1675 DI 10.1175/1520-0493(1996)124<1648:TLLSAE>2.0.CO;2 PG 28 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA VB338 UT WOS:A1996VB33800003 ER PT J AU Swart, PK Dodge, RE Hudson, HJ AF Swart, PK Dodge, RE Hudson, HJ TI A 240-year stable oxygen and carbon isotopic record in a coral from South Florida: Implications for the prediction of precipitation in Southern Florida SO PALAIOS LA English DT Article ID MONTASTREA-ANNULARIS; REEF CORAL; SCLERACTINIAN CORALS; SKELETAL CARBONATE; GROWTH; FRACTIONATION; TEMPERATURE; WATERS; BANDS; RATIO AB This study reports on the delta(18)O and delta(13)C composition of the skeleton from a 240-year-old specimen of Montastraea faveolata growing in Biscayne National Park, South Florida. Annual variations in. the delta(18)O of the skeleton deposited during the summer months show a bimodal correlation with summer rainfall. During wetter years, the delta(18)O of the coral skeleton and the amount of precipitation during the summer months are inversely correlated (r = -0.7) reflecting dilution of the seawater by meteoric water lower in delta(18)O. During years in which summer rainfall is less than normal, increases in precipitation are positively correlated with skeletal delta(18)O (r = +0.6) reflecting the input of freshwater from the Everglades higher in delta(18)O. Based on this correlation the delta(18)O record of the coral skeleton suggests that the 19th and 18th centuries have been relatively dry compared to the 20th century. Carbon isotopic compositions of the skeleton are positively correlated with delta(18)O, with the minimum in delta(13)C occurring several months after the minimum in delta(18)O. Since the mid 1930s there has been a decrease in delta(13)C of the skeleton. Explanations for this trend may be (1) it reflects the increased input of carbon derived from the destruction of terrestrial ecosystems, (2) its part of a long-term decrease in delta(13)C associated with increased addition of fossil fuel-derived CO2. C1 SE NOVA UNIV, OCEANOG CTR, DANIA, FL 33004 USA. NOAA, FLORIDA KEYS NATL MARINE SANCTUARY, KEY LARGO, FL 33149 USA. RP UNIV MIAMI, ROSENSTIEL SCH MARINE & ATMOSPHER SCI, 4600 RICKENBACKER CAUSEWAY, MIAMI, FL 33149 USA. RI Swart, Peter/K-7041-2016 NR 41 TC 50 Z9 52 U1 1 U2 7 PU SEPM-SOC SEDIMENTARY GEOLOGY PI TULSA PA 6128 EAST 38TH ST, STE 308, TULSA, OK 74135-5814 USA SN 0883-1351 EI 1938-5323 J9 PALAIOS JI Palaios PD AUG PY 1996 VL 11 IS 4 BP 362 EP 375 DI 10.2307/3515246 PG 14 WC Geology; Paleontology SC Geology; Paleontology GA VK376 UT WOS:A1996VK37600008 ER PT J AU Mortyn, PG Thunell, RC Anderson, DM Stott, LD Le, JN AF Mortyn, PG Thunell, RC Anderson, DM Stott, LD Le, JN TI Sea surface temperature changes in the Southern California borderlands during the last glacial-interglacial cycle SO PALEOCEANOGRAPHY LA English DT Article ID SAN-PEDRO-BASIN; PLANKTONIC-FORAMINIFERA; NORTHEAST PACIFIC; BIOGENIC SILICA; GREENLAND ICE; CLIMATE; OCEAN; RECORD; INSTABILITY; CIRCULATION AB A variety of evidence suggests that average sea surface temperatures (SSTs) during the last glacial maximum in the California Borderlands region were significantly colder than during the Holocene. Planktonic foraminiferal delta(18)O evidence and average SST estimates derived by the modern analog technique indicate that temperatures were 6 degrees-10 degrees C cooler during the last glacial relative to the present. The glacial plankton assemblage is dominated by the planktonic foraminifer Neogloboquadrina pachyderma (sinistral coiling) and the coccolith Coccolithus pelagicus, both of which are currently restricted to subpolar regions of the North Pacific. The glacial-interglacial average SST change determined in this study is considerably larger than the 2 degrees C change estimated by Climate: Long-Range Investigation, Mapping, and Prediction (CLIMAP) [1981]. We propose that a strengthened California Current flow was associated with the advance of subpolar surface waters into the Borderlands region during the last glacial. C1 NOAA,PALEOCLIMATOL PROGRAM,BOULDER,CO 80303. UNIV SO CALIF,DEPT EARTH SCI,LOS ANGELES,CA 90089. UNIV S CAROLINA,DEPT GEOL SCI,COLUMBIA,SC 29208. RI anderson, david/E-6416-2011; Mortyn, P. Graham/I-3860-2015 OI Mortyn, P. Graham/0000-0002-9473-4309 NR 53 TC 34 Z9 35 U1 0 U2 5 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 SN 0883-8305 J9 PALEOCEANOGRAPHY JI Paleoceanography PD AUG PY 1996 VL 11 IS 4 BP 415 EP 429 DI 10.1029/96PA01236 PG 15 WC Geosciences, Multidisciplinary; Oceanography; Paleontology SC Geology; Oceanography; Paleontology GA VM330 UT WOS:A1996VM33000005 ER PT J AU Churnside, JH Wilson, JJ Smolka, GL AF Churnside, JH Wilson, JJ Smolka, GL TI Airborne lidar keeps tabs on underwater population SO PHOTONICS SPECTRA LA English DT Article C1 BIG SKY LASER TECHNOL,BOZEMAN,MT. RP Churnside, JH (reprint author), NOAA,ENVIRONM TECHNOL LAB,OCEAN REMOTE SENSING UNIT,WASHINGTON,DC, USA. RI Churnside, James/H-4873-2013 NR 0 TC 0 Z9 0 U1 0 U2 0 PU LAURIN PUBL CO INC PI PITTSFIELD PA BERKSHIRE COMMON PO BOX 1146, PITTSFIELD, MA 01202 SN 0731-1230 J9 PHOTON SPECTRA JI Photon. Spect. PD AUG PY 1996 VL 30 IS 8 BP 109 EP 110 PG 2 WC Optics SC Optics GA VB784 UT WOS:A1996VB78400038 ER PT J AU Hauer, B Hempelmann, R Richter, D Udovic, TJ Rush, JJ Bennington, SM Dianoux, AJ AF Hauer, B Hempelmann, R Richter, D Udovic, TJ Rush, JJ Bennington, SM Dianoux, AJ TI Ground state and excited state hydrogen tunnelling in Nb1-xTxHy SO PHYSICA B-CONDENSED MATTER LA English DT Article; Proceedings Paper CT International Workshop on Quantum Tunnelling of Atoms and Molecules in Solids (QTAMS 95) CY OCT 04-07, 1995 CL CHATEAU BAUME, SEYSSINS, FRANCE SP ILL, CNRS HO CHATEAU BAUME ID NIOBIUM; DIFFUSION; METALS AB Ti represents a substitutional dopant in Nb and at low temperatures acts as hydrogen trap. For Nb0.999Ti0.001H0.001 at 1.5 K we observe a pronounced (ground state) tunnelling peak al 0.2 meV and a second weak peak at 0.4 meV in high resolution neutron spectra. The vibrationally excited state has been studied by neutron energy loss spectroscopy on Nb0.99Ti0.001H0.0094; the (fundamental) vibrational peak around 110 meV exhibits a splitting into three tunnelling lines seperated by about 4 meV. Both tunnelling phenomena indicate hydrogen delocalization over four (or perhaps six) sites. This conclusion is supported by muon spin relaxation measurements between 10 and 200 K and a QENS study at 150 K, where in both cases a localized motion (jump rotation) of the light interstitials over four sites was found. C1 FORSCHUNGSZENTRUM JULICH, INST FESTKORPERFORSCH, D-52425 JULICH, GERMANY. NIST, MAT SCI & ENGN LAB, GAITHERSBURG, MD 20899 USA. RUTHERFORD APPLETON LAB, DIDCOT OX11 0QX, OXON, ENGLAND. INST MAX VON LAUE PAUL LANGEVIN, F-38042 GRENOBLE 9, FRANCE. UNIV SAARBRUCKEN, D-66123 SAARBRUCKEN, GERMANY. RI Richter, Dieter/H-3701-2013 OI Richter, Dieter/0000-0003-0719-8470 NR 7 TC 4 Z9 4 U1 0 U2 2 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0921-4526 J9 PHYSICA B JI Physica B PD AUG PY 1996 VL 226 IS 1-3 BP 210 EP 212 DI 10.1016/0921-4526(96)00305-5 PG 3 WC Physics, Condensed Matter SC Physics GA VH548 UT WOS:A1996VH54800037 ER PT J AU Takacs, E Meyer, ES Gillaspy, JD Roberts, JR Chantler, CT Hudson, LT Deslattes, RD Brown, CM Laming, JM Dubau, J Inal, MK AF Takacs, E Meyer, ES Gillaspy, JD Roberts, JR Chantler, CT Hudson, LT Deslattes, RD Brown, CM Laming, JM Dubau, J Inal, MK TI Polarization measurements on a magnetic quadrupole line in Ne-like barium SO PHYSICAL REVIEW A LA English DT Article ID EXCITATION CROSS-SECTIONS; HIGHLY CHARGED IONS; X-RAY-DIFFRACTION; ELECTRON-BEAM; DIELECTRONIC RECOMBINATION; BRAGG GEOMETRY; BENT CRYSTALS; HE-LIKE; IONIZATION; SUBLEVELS AB We have measured the absolute polarization of the 2p(6) S-1(0)- 2p(5)((20)(3/2))3s[3/2](0)(2) magnetic quadrupole transition in Ne-like barium, excited in an electron-beam ion trap at a variety of energies. We find strong evidence for the existence of resonant excitation processes that are not explained by our collisional-radiative calculations even when the polarization arising from impact excitation is included. At energies well away from where the resonances occur, the agreement between experiment and theory is good. C1 NATL INST STAND & TECHNOL,ATOM PHYS DIV,GAITHERSBURG,MD 20899. NATL INST STAND & TECHNOL,QUANTUM METROL DIV,GAITHERSBURG,MD 20899. USN,RES LAB,EO HULBURT CTR SPACE RES,WASHINGTON,DC 20375. OBSERV PARIS,CNRS,UPR 176,F-92195 MEUDON,FRANCE. INST SCI EXACTES,DEPT PHYS,TILIMSEN 13000,ALGERIA. LAJOS KOSSUTH UNIV,EXPT PHYS DEPT,DEBRECEN,HUNGARY. SFA INC,LANDOVER,MD 20785. RI Chantler, Christopher/D-4744-2013 OI Chantler, Christopher/0000-0001-6608-0048 NR 36 TC 79 Z9 82 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 AUG PY 1996 VL 54 IS 2 BP 1342 EP 1350 DI 10.1103/PhysRevA.54.1342 PG 9 WC Optics; Physics, Atomic, Molecular & Chemical SC Optics; Physics GA VD676 UT WOS:A1996VD67600037 ER PT J AU Shaw, PS Arp, U Southworth, SH AF Shaw, PS Arp, U Southworth, SH TI Measuring nondipolar asymmetries of photoelectron angular distributions SO PHYSICAL REVIEW A LA English DT Article ID SYNCHROTRON RADIATION; CROSS-SECTIONS; PHOTOIONIZATION; SPECTROMETER; RETARDATION; PARAMETERS; MULTIPOLE AB In theories of photoelectron angular distributions at soft-x-ray energies from 1 to 10 keV, first-order corrections to the dipole approximation give rise to two nondipolar asymmetry parameters in addition to the well-known dipolar asymmetry parameter beta. The nondipolar parameters characterize the forward-backward asymmetry with respect to the propagation vector of the photon beam. Experimentally, the measurement of the nondipolar effect has been hampered because of the complications resulting from the three-parameter angular distribution. In this paper, we suggest various experimental approaches to the measurement of the three asymmetry parameters using partially linearly polarized x rays, corresponding to measurements on synchrotron radiation; beamlines. We describe methods to extract the asymmetry parameters using such approaches. C1 NATL INST STAND & TECHNOL,QUANTUM METROL DIV,GAITHERSBURG,MD 20899. ARGONNE NATL LAB,DIV PHYS,ARGONNE,IL 60439. RP Shaw, PS (reprint author), NATL INST STAND & TECHNOL,OPT TECHNOL DIV,GAITHERSBURG,MD 20899, USA. RI Arp, Uwe/C-2854-2009 NR 23 TC 26 Z9 26 U1 0 U2 0 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 1050-2947 J9 PHYS REV A JI Phys. Rev. A PD AUG PY 1996 VL 54 IS 2 BP 1463 EP 1472 DI 10.1103/PhysRevA.54.1463 PG 10 WC Optics; Physics, Atomic, Molecular & Chemical SC Optics; Physics GA VD676 UT WOS:A1996VD67600052 ER PT J AU Lorensen, HQ Parks, HV Spain, EM Smedley, JE Greene, CH Leone, SR AF Lorensen, HQ Parks, HV Spain, EM Smedley, JE Greene, CH Leone, SR TI Resonant formation of Ca+ from the Ca*(4s25d(1)D(2)) level explained by autoionization through the 3d(3/2)9f(5/2),J(pi)=2(-) resonance SO PHYSICAL REVIEW A LA English DT Article ID EARTH-METAL ATOMS; NEGATIVE-ION; ELECTRON-AFFINITIES; BINDING-ENERGIES; RYDBERG; STATES; PHOTODETACHMENT; COLLISIONS; SC AB The formation of Ca+ ions is measured in an effusive Ca beam by exciting through either the 4s4p(1)P(1) or the 4s5p(1)P(1) state to highly excited Ca*(4snd(1)D(2)) Rydberg states. In agreement with previous work by McLaughlin and Duquette [Phys. Rev. Lett. 72, 1176 (1994)], when the Rydberg states are accessed through the 4s5p(1)P(1) state, we detect a large increase in Ca+ ions for n = 25; compared to other high-n Rydberg states. It had been reported (Fabrikant [Phys. Rev. A 48, R3411 (1993)]; McLaughlin and Duquette) that ''ground-state-Rydberg-state'' collisions cause this large increase in ion production and that the result provides a precise value of the electron affinity of Ca through the binding energy of the Rydberg electron. However, a variation of the original experiment in which the same Rydberg states are accessed through the 4s4p(1)P(1) level instead of the 4s5p(1)P(1) level shows no enhancement of ions for any particular Rydberg level. With a three-laser experiment we show that the enhanced ionization effect for the 25d state is due to the 3d(3/2)9f(5/2), J(pi)=2(-) autoionizing resonance, which is coincidentally accessed from the Ca(4s25d(1)D(2)) state by the 808-nm photon involved in the original experiment by McLaughlin and Duquette. The existence of this resonance close to the experimentally observed energy is also established by R-matrix calculations. C1 UNIV COLORADO,DEPT PHYS,BOULDER,CO 80309. NATL INST STAND & TECHNOL,JOINT INST LAB ASTROPHYS,BOULDER,CO 80309. UNIV COLORADO,DEPT CHEM & BIOCHEM,BOULDER,CO 80309. NATL INST STAND & TECHNOL,DIV QUANTUM PHYS,BOULDER,CO 80303. RI Greene, Chris/C-3821-2011 OI Greene, Chris/0000-0002-2096-6385 NR 30 TC 5 Z9 5 U1 0 U2 0 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 1050-2947 J9 PHYS REV A JI Phys. Rev. A PD AUG PY 1996 VL 54 IS 2 BP 1577 EP 1585 DI 10.1103/PhysRevA.54.1577 PG 9 WC Optics; Physics, Atomic, Molecular & Chemical SC Optics; Physics GA VD676 UT WOS:A1996VD67600066 ER PT J AU Jones, KM Maleki, S Bize, S Lett, PD Williams, CJ Richling, H Knockel, H Tiemann, E Wang, H Gould, PL Stwalley, WC AF Jones, KM Maleki, S Bize, S Lett, PD Williams, CJ Richling, H Knockel, H Tiemann, E Wang, H Gould, PL Stwalley, WC TI Direct measurement of the ground-state dissociation energy of Na-2 SO PHYSICAL REVIEW A LA English DT Article ID BOSE-EINSTEIN CONDENSATION; LONG-RANGE DISPERSION; PHOTOASSOCIATIVE SPECTROSCOPY; EXCHANGE INTERACTIONS; SODIUM ATOMS; COOLED ATOMS; NA2; LITHIUM; GAS AB We report a direct measurement of the Na-2 X(1) Sigma(g)(+) ground-state dissociation energy. Three spectroscopic measurements are combined to directly yield the energy of the lowest (upsilon=O) vibrational level relative to the free-atom limit. The X(1) Sigma(g)(+) (upsilon=0-->31) splitting is measured by double-resonance spectroscopy; X(1) Sigma(g)(+)(upsilon=31)-->A(1) Sigma(u)(+)(upsilon'=165) by laser-induced fluorescence; and free atoms-->A1 Sigma(u)(+)(upsilon'=165) by photoassociation of ultracold atoms. The result is D-0=5942.6880(49) cm(-1). The uncertainty is a factor of 6 improvement over a previous (indirect) determination. C1 UNIV HANNOVER,INST ATOM & MOL PHYS,D-30167 HANNOVER,GERMANY. UNIV CONNECTICUT,DEPT PHYS,STORRS,CT 06269. WILLIAMS COLL,DEPT PHYS,WILLIAMSTOWN,MA 01267. ECOLE NORMALE SUPER,F-75231 PARIS 05,FRANCE. UNIV CHICAGO,JAMES FRANCK INST,CHICAGO,IL 60637. RP Jones, KM (reprint author), NIST,ATOM PHYS DIV,GAITHERSBURG,MD 20899, USA. RI Williams, Carl/B-5877-2009 NR 26 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 1050-2947 J9 PHYS REV A JI Phys. Rev. A PD AUG PY 1996 VL 54 IS 2 BP R1006 EP R1009 PG 4 WC Optics; Physics, Atomic, Molecular & Chemical SC Optics; Physics GA VD676 UT WOS:A1996VD67600006 ER PT J AU Bao, W Broholm, C Honig, JM Metcalf, P Trevino, SF AF Bao, W Broholm, C Honig, JM Metcalf, P Trevino, SF TI Itinerant antiferromagnetism in the Mott compound V1.973O3 SO PHYSICAL REVIEW B LA English DT Article ID SPIN-DENSITY-WAVE; ELECTRON FERROMAGNETISM; MAGNETIC FLUCTUATIONS; QUANTITATIVE ASPECTS; NEUTRON-SCATTERING; TEMPERATURE; NICKEL; SUPERCONDUCTIVITY; EXCITATIONS; DEPENDENCE AB The doping-induced metallic state of the Mott system V2-yO3 has spin-density-wave order for T centered at each antiferromagnetic Bragg point. The q, omega. and T dependence of magnetic fluctuations can be described by the self-consistent renormalization theory for weak itinerant antiferromagnets developed by Moriya, Hasegawa, and Nakayama. Thermodynamic properties below similar to 10T(N) are quantitatively accounted for by this theory in its simplest form with only four parameters, which are determined by our neutron-scattering experiment. C1 JOHNS HOPKINS UNIV,BALTIMORE,MD 21218. NATL INST STAND & TECHNOL,GAITHERSBURG,MD 20899. PURDUE UNIV,W LAFAYETTE,IN 47907. USA,RES LAB,ADELPHI,MD 20783. RP Bao, W (reprint author), BROOKHAVEN NATL LAB,UPTON,NY 11973, USA. RI Broholm, Collin/E-8228-2011; Bao, Wei/E-9988-2011 OI Broholm, Collin/0000-0002-1569-9892; Bao, Wei/0000-0002-2105-461X NR 38 TC 25 Z9 25 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 AUG 1 PY 1996 VL 54 IS 6 BP R3726 EP R3729 PG 4 WC Physics, Condensed Matter SC Physics GA VD677 UT WOS:A1996VD67700015 ER PT J AU Petit, P Robert, J Yildirim, T Fischer, JE AF Petit, P Robert, J Yildirim, T Fischer, JE TI ESR evidence for phonon-mediated resistivity in alkali-metal-doped fullerides SO PHYSICAL REVIEW B LA English DT Article ID RB3C60; K3C60; C-60 AB The temperature dependence of ESR linewidths and g values for the fulleride superconductors K3C60, Rb3C60 and Na2CsC60 are reported. Following the Elliott-Yafet theory of electronic relaxation in metals, we compare the temperature dependence of the linewidth divided by the square of the difference of g from the free-electron value with the temperature dependence of the resistivity. We show that the Elliott relation applies for all three compounds, implying a normal-state resistivity dominated by electron-phonon interactions. C1 UNIV MARYLAND,COLLEGE PK,MD 20742. NATL INST STAND & TECHNOL,GAITHERSBURG,MD 20899. UNIV PENN,DEPT MAT SCI,PHILADELPHIA,PA 19104. UNIV PENN,RES STRUCT MATTER LAB,PHILADELPHIA,PA 19104. RP Petit, P (reprint author), INST CHARLES SADRON,6 RUE BOUSSINGAULT,F-67000 STRASBOURG,FRANCE. RI yildirim, taner/A-1290-2009 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 0163-1829 J9 PHYS REV B JI Phys. Rev. B PD AUG 1 PY 1996 VL 54 IS 6 BP R3764 EP R3767 PG 4 WC Physics, Condensed Matter SC Physics GA VD677 UT WOS:A1996VD67700025 ER PT J AU Franaszek, M Simiu, E AF Franaszek, M Simiu, E TI Stochastic resonance: A chaotic dynamics approach SO PHYSICAL REVIEW E LA English DT Article ID NOISE; CRAYFISH; SYSTEMS AB For a class of multistable systems it follows from qualitative results of Melnikov theory that deterministic and stochastic excitations play equivalent roles in the promotion of chaos. We use such results to suggest (1) a method for assessing the role of the noise spectrum in enhancing the signal-to-noise ratio (SNR), the most effective spectral shape being that for which the power is distributed closest to the frequency of the Melnikov scale factor's peak; (2) a method for more effective SNR enhancement than can be achieved by increasing the noise, wherein the noise is left unchanged and a harmonic excitation with frequency based on the system's Melnikov scale factor is added to the system. The effectiveness of our Melnikov-based methods is confirmed by numerical simulations. The principle of a practical and effective nonlinear transduction device for enhancing SNR is proposed and demonstrated numerically. C1 CRACOW PEDAG UNIV,INST PHYS,KRAKOW,POLAND. RP Franaszek, M (reprint author), NIST,BLDG & FIRE RES LAB,BLDG 226,GAITHERSBURG,MD 20899, USA. NR 21 TC 18 Z9 18 U1 1 U2 1 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 1063-651X J9 PHYS REV E JI Phys. Rev. E PD AUG PY 1996 VL 54 IS 2 BP 1298 EP 1304 DI 10.1103/PhysRevE.54.1298 PG 7 WC Physics, Fluids & Plasmas; Physics, Mathematical SC Physics GA VD674 UT WOS:A1996VD67400043 ER PT J AU Foest, R Olthoff, JK VanBrunt, RJ Benck, EC Roberts, JR AF Foest, R Olthoff, JK VanBrunt, RJ Benck, EC Roberts, JR TI Optical and mass spectrometric investigations of ions and neutral species in SF6 radio-frequency discharges SO PHYSICAL REVIEW E LA English DT Article ID RF-GLOW-DISCHARGES; RADIOFREQUENCY REFERENCE CELL; KINETIC-ENERGY DISTRIBUTIONS; EMISSION SPECTROSCOPY; PARALLEL-PLATE; BY-PRODUCTS; PLASMA; ELECTRON; SILICON; GAS AB Radio-frequency (rf) discharges at 13.56 MHz were generated in pure SF6 using a capacitively coupled, parallel-plate GEC reference cell for gas pressures in the range of 4-33.3 Pa (30-250 mTorr) and for peak-to-peak applied rf voltages in the range of 100-300 V. The following measurements were made during operation of the discharge: (1) electrical characteristics which included power dissipation, voltage-current phase angle, and the de self-bias; (2) time-averaged vertical and horizontal profiles of the optical emissions from neutral atomic fluorine for the 2p(4)3p' F-2(7/2)0-->2p(4)3s' D-2(5/2) and 2p(4)3p (2)p(3/2)(0)-->2p(4)3s P-2(3/2) transitions; (3) spatially resolved, laser-induced fluorescence (LIF) utilizing the 2p(4)3s P-4(5/2) metastable level of atomic fluorine; (4) mass spectra of neutral species in the plasma; and (5) kinetic-energy distributions and relative fluxes of mass-selected positive ions extracted from the plasma through a 0.1 mm diameter orifice ill the grounded electrode. The dependence of the electrical characteristics on gas pressure confirms previous observations and model predictions which indicate, for example, that the plasma becomes more resistive as pressure increases. The optical-emission and LIF results are also consistent with previously reported pronounced peaks in emission intensity in front of the powered electrode and a complex double-layer formation at the plasma-sheath boundary, which can be attributed to the strong electron-attaching properties of the gas. Front the mass-spectrometric observations of the neutral gas constituents, it can be inferred that a significant fraction (as much as 80% in some cases) of the SF6 in the cell can be dissociated or decomposed when the discharge is on for an input gas flow rate of 1.5x10(-6) mol s(-1) (2.0 cubic centimeters per minute at standard temperature and pressure). The measured ion-energy distributions exhibit deviations from the simple ''rf-saddle structure'' that become more pronounced with decreasing ion mass. The ion-energy distributions also exhibit pronounced dependences on pressure and applied voltage that appear to be consistent with corresponding changes in the electrical characteristics and LIF. Changes in electrode-surface conditions produced by the discharge were found to dramatically affect the ion-energy distributions, LIF, and electrical characteristics. C1 NIST,DIV ELECT,ELECT & ELECT ENGN LAB,GAITHERSBURG,MD 20899. NIST,PHYS LAB,ATOM PHYS DIV,GAITHERSBURG,MD 20899. RP Foest, R (reprint author), INST NIEDERTEMPERATUR PLASMAPHYS,D-17489 GREIFSWALD,GERMANY. NR 55 TC 33 Z9 34 U1 0 U2 2 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 1063-651X J9 PHYS REV E JI Phys. Rev. E PD AUG PY 1996 VL 54 IS 2 BP 1876 EP 1887 DI 10.1103/PhysRevE.54.1876 PG 12 WC Physics, Fluids & Plasmas; Physics, Mathematical SC Physics GA VD674 UT WOS:A1996VD67400115 ER PT J AU AlSheikhly, M McLaughlin, WL AF AlSheikhly, M McLaughlin, WL TI On the mechanisms of radiation-induced curing of epoxy-fiber composites SO RADIATION PHYSICS AND CHEMISTRY LA English DT Article AB Depending on the monomer molecular structure, the mechanisms of radiation-induced polymerization proceed via either C-centered radical mechanisms or cationic polymerization. While polymerization via C-centered radicals can be impeded by the presence of oxygen and high dose-rate, polymerization through cationic polymerization is inhibited even by the presence of trace amounts of water. Synergy by the combination of radiation and thermal curing can help to achieve various desired properties of polymer-fiber composite materials. Copyright (C) 1996 Elsevier Science Ltd. C1 US DEPT COMMERCE,TECHNOL ADMIN,NIST,PHYS LAB,IONIZING RADIAT DIV,GAITHERSBURG,MD 20899. RP AlSheikhly, M (reprint author), UNIV MARYLAND,DEPT MAT & NUCL ENGN,COLLEGE PK,MD 20742, USA. NR 19 TC 5 Z9 5 U1 0 U2 3 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD, ENGLAND OX5 1GB J9 RADIAT PHYS CHEM JI Radiat. Phys. Chem. PD AUG PY 1996 VL 48 IS 2 BP 201 EP 206 DI 10.1016/0969-806X(95)00415-T PG 6 WC Chemistry, Physical; Nuclear Science & Technology; Physics, Atomic, Molecular & Chemical SC Chemistry; Nuclear Science & Technology; Physics GA VA385 UT WOS:A1996VA38500006 ER PT J AU Dobrow, RP Smythe, RT AF Dobrow, RP Smythe, RT TI Poisson approximations for functionals of random trees SO RANDOM STRUCTURES & ALGORITHMS LA English DT Article; Proceedings Paper CT 17th International Conference on Random Structures and Algorithms CY MAY 16-20, 1995 CL EMORY UNIV, ATLANTA, GA HO EMORY UNIV DE Poisson approximation; binary search trees; increasing trees; recursive trees ID RECURSIVE TREES AB We use Poisson approximation techniques for sums of indicator random variables to derive explicit error bounds and central limit theorems for several functionals of random trees. In particular, we consider (i) the number of comparisons for successful and unsuccessful search in a binary search tree and (ii) internode distances in increasing trees. The Poisson approximation setting is shown to be a natural and fairly simple framework for deriving asymptotic results. (C) 1996 John Wiley & Sons, Inc. C1 GEORGE WASHINGTON UNIV,WASHINGTON,DC 20052. NATL INST STAND & TECHNOL,STAT ENGN DIV,BOULDER,CO 80303. RP Dobrow, RP (reprint author), NE MISSOURI STATE UNIV,DIV MATH & COMP SCI,KIRKSVILLE,MO 63501, USA. NR 19 TC 14 Z9 14 U1 0 U2 2 PU JOHN WILEY & SONS LTD PI W SUSSEX PA BAFFINS LANE CHICHESTER, W SUSSEX, ENGLAND PO19 1UD SN 1042-9832 J9 RANDOM STRUCT ALGOR JI Random Struct. Algorithms PD AUG-SEP PY 1996 VL 9 IS 1-2 BP 79 EP 92 DI 10.1002/(SICI)1098-2418(199608/09)9:1/2<79::AID-RSA5>3.0.CO;2-8 PG 14 WC Computer Science, Software Engineering; Mathematics, Applied; Mathematics SC Computer Science; Mathematics GA VE483 UT WOS:A1996VE48300005 ER PT J AU Kautz, RL AF Kautz, RL TI Noise, chaos, and the Josephson voltage standard SO REPORTS ON PROGRESS IN PHYSICS LA English DT Review ID DRIVEN DAMPED-PENDULUM; NON-LINEAR TRANSFORMATIONS; THERMALLY INDUCED ESCAPE; LOW-FREQUENCY NOISE; RF-INDUCED STEPS; TUNNEL-JUNCTIONS; INTERMITTENT CHAOS; SERIES-ARRAY; DYNAMICAL-SYSTEMS; DEVILS STAIRCASE AB The design of zero-bias Josephson voltage standards is presented as a case study in nonlinear dynamics. Based on superconducting tunnel junctions, such standards rely on nonlinearity to create a phase lock between an internal junction variable and an applied rf bias. In the terminology of nonlinear dynamics, phase lock corresponds to motion on a periodic attractor. Not all attractors of the rf-biased junction are periodic, however, and both quasiperiodic and chaotic attractors must be avoided in voltage standards. Surprisingly, the optimum operating point for zero-bias standards is near a region of chaos. Thus, the Josephson coupling energy E(J), a measure of the junction's nonlinearity, must be chosen much larger than the thermal energy k(B)T to avoid disruption by intrinsic noise but not so large that chaos is evoked. The optimum E(J) maximizes the activation energy E(A) required for thermally induced escape from the phase-locked attractor. For nonequilibrium systems like the rf-biased junction, E(A) is a difference in quasipotential that can be calculated by finding the most probable path for escape from a basin of attraction in the limit of low temperature. RP Kautz, RL (reprint author), NATL INST STAND & TECHNOL,BOULDER,CO 80303, USA. NR 176 TC 116 Z9 116 U1 4 U2 13 PU IOP PUBLISHING LTD PI BRISTOL PA TECHNO HOUSE, REDCLIFFE WAY, BRISTOL, ENGLAND BS1 6NX SN 0034-4885 J9 REP PROG PHYS JI Rep. Prog. Phys. PD AUG PY 1996 VL 59 IS 8 BP 935 EP 992 DI 10.1088/0034-4885/59/8/001 PG 58 WC Physics, Multidisciplinary SC Physics GA VD894 UT WOS:A1996VD89400001 ER PT J AU Benenson, RE ChenMayer, HH Sharov, V AF Benenson, RE ChenMayer, HH Sharov, V TI Portable time of flight system for thermal and cold neutron applications SO REVIEW OF SCIENTIFIC INSTRUMENTS LA English DT Article ID POLYCAPILLARY AB A very small Fermi-type neutron chopper fashioned by cutting slots in a boron nitride cylinder was developed for use with a source of thermal and cold (subthermal velocity) neutrons. The original goal was to characterize spectra emerging from glass capillary fibers of less than 1 mm diameter, but other applications became apparent. For approximately 1 m flight paths, conventional nuclear electronics had to be adapted to the millisecond flight times. Both time-to-amplitude converter and multiscaling time-data storage methods were used. Data corrections for the particular geometry are reviewed and applied to the present geometry. Among examples of its potential use, the spectrum of a newly installed cold source was measured. (C) 1996 American Institute of Physics. C1 XRAY OPT SYST,ALBANY,NY 12305. RP Benenson, RE (reprint author), NIST,GAITHERSBURG,MD 20899, USA. NR 6 TC 0 Z9 0 U1 0 U2 0 PU AMER INST PHYSICS PI WOODBURY PA CIRCULATION FULFILLMENT DIV, 500 SUNNYSIDE BLVD, WOODBURY, NY 11797-2999 SN 0034-6748 J9 REV SCI INSTRUM JI Rev. Sci. Instrum. PD AUG PY 1996 VL 67 IS 8 BP 2770 EP 2774 DI 10.1063/1.1147106 PG 5 WC Instruments & Instrumentation; Physics, Applied SC Instruments & Instrumentation; Physics GA VC773 UT WOS:A1996VC77300017 ER PT J AU Maruyama, B Gundel, DB AF Maruyama, B Gundel, DB TI Spatially varied interfaces SO SCRIPTA MATERIALIA LA English DT Article C1 SYSTRAN CO,DAYTON,OH 45432. RP Maruyama, B (reprint author), NATL INST STAND & TECHNOL,WRIGHT LAB,MLLM,2230 10TH ST STE 1,WRIGHT PATTERSON AFB,OH 45433, USA. NR 11 TC 7 Z9 7 U1 0 U2 0 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD, ENGLAND OX5 1GB SN 1359-6462 J9 SCRIPTA MATER JI Scr. Mater. PD AUG 1 PY 1996 VL 35 IS 3 BP 391 EP 395 DI 10.1016/1359-6462(96)00127-3 PG 5 WC Nanoscience & Nanotechnology; Materials Science, Multidisciplinary; Metallurgy & Metallurgical Engineering SC Science & Technology - Other Topics; Materials Science; Metallurgy & Metallurgical Engineering GA UU397 UT WOS:A1996UU39700017 ER PT J AU Wiebe, PH Beardsley, RC Mountain, DG Bucklin, A AF Wiebe, PH Beardsley, RC Mountain, DG Bucklin, A TI Global ocean ecosystem dynamics - Initial program in northwest Atlantic SO SEA TECHNOLOGY LA English DT Article C1 WOODS HOLE OCEANOG INST,DEPT PHYS OCEANOG,WOODS HOLE,MA 02543. NOAA,NATL MARINE FISHERIES SERV,ENVIRONM PROC DIV,WOODS HOLE,MA 02543. UNIV NEW HAMPSHIRE,INST STUDY EARTH OCEANS & SPACE,DURHAM,NH 03824. RP Wiebe, PH (reprint author), WOODS HOLE OCEANOG INST,DEPT BIOL,WOODS HOLE,MA 02543, USA. NR 0 TC 13 Z9 14 U1 0 U2 0 PU COMPASS PUBL INC PI ARLINGTON PA SUITE 1000 1117 N 19 ST, ARLINGTON, VA 22209 SN 0093-3651 J9 SEA TECHNOL JI Sea Technol. PD AUG PY 1996 VL 37 IS 8 BP 67 EP 76 PG 10 WC Engineering, Ocean SC Engineering GA VD277 UT WOS:A1996VD27700009 ER PT J AU Semancik, S Cavicchi, RE Kreider, KG Suehle, JS Chaparala, P AF Semancik, S Cavicchi, RE Kreider, KG Suehle, JS Chaparala, P TI Selected-area deposition of multiple active films for conductometric microsensor arrays SO SENSORS AND ACTUATORS B-CHEMICAL LA English DT Article; Proceedings Paper CT 8th International Conference on Solid-State Sensors and Actuators (Eurosensors IX) CY JUN 25-29, 1995 CL STOCKHOLM, SWEDEN DE arrays; chemical vapor deposition; conductance; micromachining; microsensors; tin oxide ID GROWTH AB A new generation of planar conductometric gas sensors is being developed which combines active semiconducting oxide films with Si-micromachined 'micro-hotplate' array structures. These devices are tailored for a variety of applications by tuning both the composition of multiple types of active films and the temperature cycles programmed for individual elements within an array. In this paper we describe and demonstrate the approach, and present results for, a chemical vapor deposition (CVD)-based self-lithographic microfabrication method. This method is being examined as a highly efficient and compatible means of depositing oxide films and low-coverage catalytic metal overlayers on the microsensor elements of micro-hotplate arrays. Real-time monitoring of the film growth processes is provided by conductance measurements, and surveys of processing/property relationships can be performed in a very effective manner to determine optimal fabrication methods for multiple-active material arrays. C1 NATL INST STAND & TECHNOL,ELECT & ELECT ENGN LAB,GAITHERSBURG,MD 20899. RP Semancik, S (reprint author), NATL INST STAND & TECHNOL,CHEM SCI & TECHNOL LAB,GAITHERSBURG,MD 20899, USA. NR 6 TC 38 Z9 38 U1 1 U2 2 PU ELSEVIER SCIENCE SA LAUSANNE PI LAUSANNE PA PO BOX 564, 1001 LAUSANNE, SWITZERLAND SN 0925-4005 J9 SENSOR ACTUAT B-CHEM JI Sens. Actuator B-Chem. PD AUG PY 1996 VL 34 IS 1-3 BP 209 EP 212 DI 10.1016/S0925-4005(96)01823-0 PG 4 WC Chemistry, Analytical; Electrochemistry; Instruments & Instrumentation SC Chemistry; Electrochemistry; Instruments & Instrumentation GA WC209 UT WOS:A1996WC20900001 ER PT J AU Watari, S Smith, Z Garcia, HA Detman, T Dryer, M AF Watari, S Smith, Z Garcia, HA Detman, T Dryer, M TI Coronal change at the south-west limb observed by Yohkoh on 9 November 1991, and the subsequent interplanetary shock at Pioneer Venus Orbiter SO SOLAR PHYSICS LA English DT Article ID MASS EJECTION; DISTURBANCES; EVOLUTION; STREAMER; FILAMENT; FLARES AB A spectacular change in the lower corona on the south-west limb has been found in solar images taken by the Yohkoh soft X-ray telescope. The event is characterized by a large topological change in magnetic field and a large intensity decrease observed after the X1.1/1B hare on 9 November, 1991. A coronal mass ejection (CME) was observed by the Mark III K-coronameter (MK3) at the HAO/Mauna Loa Observatory. Both the MK3 (white-light) and soft X-ray observations showed that one leg of this CME was located above the flare site. An interplanetary shock associated with this event was observed by Pioneer Venus Orbiter, and, possibly, by IMP-8. C1 NOAA,SPACE ENVIRONM CTR,BOULDER,CO 80303. UNIV COLORADO,COOPERAT INST RES ENVIRONM SCI,BOULDER,CO 80309. RP Watari, S (reprint author), COMMUN RES LABS,KOGANEI,TOKYO 184,JAPAN. RI xue, yansheng/A-9712-2012 NR 29 TC 2 Z9 2 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 AUG PY 1996 VL 167 IS 1-2 BP 357 EP 369 DI 10.1007/BF00146345 PG 13 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA VB303 UT WOS:A1996VB30300023 ER PT J AU VanderHart, DL McFadden, GB AF VanderHart, DL McFadden, GB TI Some perspectives on the interpretation of proton NMR spin diffusion data in terms of polymer morphologies SO SOLID STATE NUCLEAR MAGNETIC RESONANCE LA English DT Article DE morphology; polymer; proton spin diffusion ID NUCLEAR-MAGNETIC-RESONANCE; MULTIPLE PULSE NMR; MODEST MONOMER SIZE; LATTICE RELAXATION; SEMICRYSTALLINE POLYMERS; BLENDS; SOLIDS; RESOLUTION; SEPARATION; H-1-NMR AB Proton spin diffusion data yield morphological information over dimensions covering approximately the 2-50 nm range. In this article, the interpretation of such data for polymers is emphasized, recognizing that the mathematical framework for much of this interpretation already exists in the literature. Practical issues are considered, for example, a useful scaling of plotted data is suggested, key attributes of the data are identified and ambiguities in the mapping of data into morphological models are spelled out. Discussion is limited to two-phase systems, where it is assumed that, by employing multiple-pulse methods, polarization gradients can be generated, whose spatial sharpness is limited solely by the morphological definition of the interfaces, Interpretation of data in terms of morphology and stoichiometry is emphasized, where stoichiometric issues pertain only to chemically heterogeneous systems. Extraction of stoichiometric information from spin diffusion data is not commonly attempted; the discussion included herein allows for the possibility that the composition of phases may be chemically mixed. Methods for generating gradients are discussed only briefly. A standardized spin diffusion plot is proposed and the initial slope of this plot is focussed on for providing information about morphology and stoichiometry. Ambiguities of interpretation considered include the dimensionality of the deduced morphology and, for systems with chemical heterogeneity, the uniqueness of the compositional characterization of each phase. In addition, finite difference methods are used to simulate entire spin diffusion curves for idealized lamellar and hexagonal rod/matrix morphologies. Comparisons of these curves show that distinguishing 1-D and 2-D morphologies on the basis of experimental data is unlikely to be successful over the range of stoichiometries where such morphologies are expected. Several examples of spin diffusion data are presented. Brief treatments of the following topics are included: finite interface width, estimation of spin diffusion constants, and incorporation of longitudinal relaxation effects. Finally, a short experimental discussion on the preparation of polarization gradients is given, including those preparations which make use of differences in the multiple-pulse relaxation time, T-1xz. It is noted that T-1xz decays may be strongly perturbed in the presence of magic angle spinning; therefore, strategies are also outlined for minimizing these effects. C1 NATL INST STAND & TECHNOL,APPL & COMPUTAT MATH DIV,GAITHERSBURG,MD 20899. RP VanderHart, DL (reprint author), NATL INST STAND & TECHNOL,DIV POLYMERS,GAITHERSBURG,MD 20899, USA. RI McFadden, Geoffrey/A-7920-2008 OI McFadden, Geoffrey/0000-0001-6723-2103 NR 49 TC 123 Z9 123 U1 2 U2 13 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0926-2040 J9 SOLID STATE NUCL MAG JI Solid State Nucl. Magn. Reson. PD AUG PY 1996 VL 7 IS 1 BP 45 EP 66 DI 10.1016/0926-2040(96)01233-7 PG 22 WC Chemistry, Physical; Physics, Atomic, Molecular & Chemical; Physics, Condensed Matter; Spectroscopy SC Chemistry; Physics; Spectroscopy GA VQ184 UT WOS:A1996VQ18400005 PM 8906414 ER PT J AU Mee, RW Eberhardt, KR AF Mee, RW Eberhardt, KR TI A comparison of uncertainty criteria for calibration SO TECHNOMETRICS LA English DT Article DE inverse regression; simulation; simultaneous prediction intervals; simultaneous tolerance intervals ID SIMULTANEOUS CONFIDENCE-REGIONS; TOLERANCE LIMITS; REGRESSION; PREDICTIONS; INTERVALS AB Calibration consists of using a fitted regression line to estimate the value of an unobserved independent variable x corresponding to an observed dependent variable y. To construct a confidence interval for a single x, Eisenhart introduced a procedure that consists of inverting prediction intervals around the regression line. Numerous other inference procedures have been proposed for multiple-use calibration, in which a single fitted regression line is used repeatedly to estimate many x's. We provide a synthesis of this literature and offer some numerical comparisons. We also attempt to motivate the use of various criteria based on the particular points of view of the various parties involved in determining the calibration or using the results. In addition, we derive probability expressions for computing exact simultaneous prediction intervals that enable the construction of tighter limits than are currently available based on that criterion. C1 NIST,STAT ENGN DIV,GAITHERSBURG,MD 20899. RP Mee, RW (reprint author), UNIV TENNESSEE,DEPT STAT,KNOXVILLE,TN 37996, USA. NR 20 TC 7 Z9 7 U1 0 U2 1 PU AMER STATIST ASSN PI ALEXANDRIA PA 1429 DUKE ST, ALEXANDRIA, VA 22314 SN 0040-1706 J9 TECHNOMETRICS JI Technometrics PD AUG PY 1996 VL 38 IS 3 BP 221 EP 229 DI 10.2307/1270605 PG 9 WC Statistics & Probability SC Mathematics GA UY709 UT WOS:A1996UY70900005 ER PT J AU Thacker, WC AF Thacker, WC TI Metric-based principal components: Data uncertainties SO TELLUS SERIES A-DYNAMIC METEOROLOGY AND OCEANOGRAPHY LA English DT Article ID CLIMATE; SYSTEM AB Seeking an index characterizing the best-determined mode of variability leads to a natural generalization of principal-component analysis with an explicit metric characterizing the uncertainties of the data. This formalism, which distinguishes between stale-space patterns ms and patterns of coefficients defining principal components, allows the more accurate data to exert a greater influence on the definition oi-the indices than they do in conventional principal-component analysis; in all other aspects, the new formalism is the same as the old. Within the context of the simple example of Bretherton and collaborators, metric-based principal-component analysis is shown to be capable of finding correlated patterns of variability in two different data sets. RP Thacker, WC (reprint author), NOAA,ATLANTIC OCEANOG & METEOROL LAB,4301 RICKENBACKER CAUSEWAY,MIAMI,FL 33149, USA. RI Thacker, Carlisle/I-3813-2013 OI Thacker, Carlisle/0000-0002-9285-8826 NR 12 TC 10 Z9 11 U1 0 U2 1 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 AUG PY 1996 VL 48 IS 4 BP 584 EP 592 DI 10.1034/j.1600-0870.1996.t01-3-00007.x PG 9 WC Meteorology & Atmospheric Sciences; Oceanography SC Meteorology & Atmospheric Sciences; Oceanography GA VD107 UT WOS:A1996VD10700007 ER PT J AU Xiang, D Hsu, NN Blessing, GV AF Xiang, D Hsu, NN Blessing, GV TI The design, construction and application of a large aperture lens-less line-focus PVDF transducer SO ULTRASONICS LA English DT Article DE transducers; materials characterization; Green's function ID BEAM ACOUSTIC MICROSCOPE; V(Z) AB A large aperture lens-less line-focus transducer for materials characterization is described. The transducer design is based on a time-domain Green's function formalism, which also yields good theoretical corroboration of the experimental results. The transducer construction is readily achieved by conforming commercial polyvinylidene fluoride (PVDF) him to a cylindrical (convex) surface, followed by casting a tungsten-powder-loaded epoxy resin backing material into an attached housing. This transducer can be used to characterize sample material properties by simultaneously measuring surface wave speeds and bulk wave transit times, from which the thickness and anisotropy may be deduced. C1 NIST, AUTOMATED PROD TECHNOL DIV, GAITHERSBURG, MD 20899 USA. NR 29 TC 65 Z9 71 U1 3 U2 9 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0041-624X J9 ULTRASONICS JI Ultrasonics PD AUG PY 1996 VL 34 IS 6 BP 641 EP 647 DI 10.1016/0041-624X(96)00058-3 PG 7 WC Acoustics; Radiology, Nuclear Medicine & Medical Imaging SC Acoustics; Radiology, Nuclear Medicine & Medical Imaging GA VJ131 UT WOS:A1996VJ13100004 ER PT J AU Wang, YL Fernandez, JE Cuervo, DG AF Wang, YL Fernandez, JE Cuervo, DG TI Rolling-contact fatigue lives of steel AISI 52100 balls with eight mineral and synthetic lubricants SO WEAR LA English DT Article DE rolling fatigue; synthetic oil; mineral oil; pressure-viscosity coefficient; 52100 steel ball; fatigue life; S-N curve AB This work has evaluated the rolling-contact fatigue lives of AISI 52100 steel balls with several mineral and synthetic oils with and without additive using a four-ball tester. The studied lubricants include S.N.-350 (mineral oil), S,N.-600 (mineral oil), TMP-05 (synthetic polyol ester), TMP-05 + 2%ZnDDP, P.A.G.-9 (synthetic polyalkyl glycol), P.A.G.-12 (synthetic polyalkyl glycol) and Breox-B-135X (synthetic polyalkyl glycol). Weibull plots and S-N (stress-number of cycles) of L(10) and L(50) are given to all the tested oils. Pressure-viscosity coefficients for different tested oils are estimated experimentally for understanding the fatigue test results, The results indicate: (1) synthetic polybutene HYVIS-07 gives the longest rolling-contact fatigue life to AISI 52100 steel balls among all the mineral and synthetic oils studied in the present work, which may be attributed to its highest pressure-viscosity coefficient among the tested oils; (2) the rolling fatigue performance of a synthetic oil can be better or worse than that of a mineral oil, depending on the nature of the synthetic oil family. The capability of improving the rolling fatigue lives of tested mineral and synthetic oils increases in the order synthetic polyol ester, synthetic polyalkyl glycol, mineral oil, and synthetic polybutene; (3) a higher viscosity in synthetic oil will lead to a longer rolling life, but the influence of viscosity in synthetic oil on the rolling fatigue life of steel balls will be less than that of changing synthetic oil family; (4) synthetic oil with E.P. antiwear additive has a longer rolling fatigue life compared with the case without additive. C1 UNIV OVIEDO,DEPT CIVIL ENGN & MECH,GIJON 33204,ASTURIAS,SPAIN. RP Wang, YL (reprint author), NIST,DIV CERAM,GAITHERSBURG,MD 20899, USA. NR 12 TC 17 Z9 17 U1 0 U2 3 PU ELSEVIER SCIENCE SA LAUSANNE PI LAUSANNE 1 PA PO BOX 564, 1001 LAUSANNE 1, SWITZERLAND SN 0043-1648 J9 WEAR JI Wear PD AUG PY 1996 VL 196 IS 1-2 BP 110 EP 119 DI 10.1016/0043-1648(95)06857-0 PG 10 WC Engineering, Mechanical; Materials Science, Multidisciplinary SC Engineering; Materials Science GA VB353 UT WOS:A1996VB35300015 ER PT J AU Defibaugh, DR Gillis, KA Moldover, MR Schmidt, JW Weber, LA AF Defibaugh, DR Gillis, KA Moldover, MR Schmidt, JW Weber, LA TI Thermodynamic properties of CF3-CHF-CHF2, 1,1,1,2,3,3-hexafluoropropane SO FLUID PHASE EQUILIBRIA LA English DT Article DE critical point; thermodynamic properties; equation of state; 1,1,1,2,3,3-hexafluoropropane; thermal machinery; vapor pressure ID VAPOR-PRESSURE; EBULLIOMETRIC MEASUREMENT; EQUATION; STATE; R123 AB We report the thermodynamic properties of 1,1,1,2,3,3-hexafluoropropane (known in the refrigeration industry as R236ea or HFC-236ea) in the temperature and pressure region commonly encountered in thermal machinery. The properties are based on measurements of the vapor pressure, the density of the compressed liquid (PVT), the refractive index of the saturated liquid and vapor, the critical temperature, and the speed of sound in the vapor phase. The surface tension was determined from the capillary rise. From these data we deduce the ideal-gas heat-capacity, the saturated liquid and vapor densities, the equation of state of the vapor phase, the surface tension, and estimates of the critical pressure and density. The data determine the coefficients for a Carnahan-Starlings-DeSantis (CSD) equation of state. The CSD coefficients found in REFPROP 4.0 database are based on these present measurements. RP Defibaugh, DR (reprint author), NIST,DIV THERMOPHYS,CHEM SCI & TECHNOL LAB,GAITHERSBURG,MD 20899, USA. RI Moldover, Michael/E-6384-2013 NR 15 TC 25 Z9 25 U1 2 U2 2 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0378-3812 J9 FLUID PHASE EQUILIBR JI Fluid Phase Equilib. PD JUL 31 PY 1996 VL 122 IS 1-2 BP 131 EP 155 DI 10.1016/0378-3812(96)03003-8 PG 25 WC Thermodynamics; Chemistry, Physical; Engineering, Chemical SC Thermodynamics; Chemistry; Engineering GA VF368 UT WOS:A1996VF36800010 ER PT J AU Schmidt, JW CarrilloNava, E Moldover, MR AF Schmidt, JW CarrilloNava, E Moldover, MR TI Partially halogenated hydrocarbons CHFCl-CF3, CF3-CH3, CF3-CHF-CHF2, CF3-CH2-CF3, CHF2-CF2-CH2F, CF3-CH2-CHF2, CF3-O-CHF2: Critical temperature, refractive indices, surface tension and estimates of liquid, vapor and critical densities SO FLUID PHASE EQUILIBRIA LA English DT Article DE experimental; critical temperature; density; surface tension; refrigerants; chloro-tetrafluoroethane; trifluoroethane; hexafluoropropane; pentafluoropropane; pentafluoro-dimethyl ether ID MIXTURES AB For seven partially halogenated hydrocarbons, designated by the refrigeration industry as the refrigerants R124, R143a, R236ea, R236fa, R245ca, R245fa, and E125, we determined the critical temperatures T-c (ITS-90), the capillary rise, and the refractive indices of the liquid and vapor phases in the temperature range from 20 degrees C to their critical points. Independently measured liquid densities at lower temperatures, when combined with our refractive indices, produce estimates of the vapor and liquid densities at higher temperatures up to the critical point. The densities combined with the capillary rise data give the surface tensions, sigma, up to the critical points. The surface tensions of the seven refrigerants in this study together with nine others measured previously can be represented by the scaled equation sigma = 2.51(1 + 0.609 omega)k(b)T(c)(N-a/V-c)(2/3)t(1.26)(1 + 0.948t(1/2) - 0.487t) where t = (T-c - T)/T-c is the reduced temperature, and k(b), N-a, V-c, and omega are the Boltzmann and Avagadro constants, the critical volume, and the acentric factor, respectively. This equation yields values for a within 5% of the measured values for all 16 candidate replacement refrigerants. RP Schmidt, JW (reprint author), NIST,DIV THERMOPHYS,GAITHERSBURG,MD 20899, USA. RI Moldover, Michael/E-6384-2013 NR 20 TC 55 Z9 55 U1 1 U2 4 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0378-3812 J9 FLUID PHASE EQUILIBR JI Fluid Phase Equilib. PD JUL 31 PY 1996 VL 122 IS 1-2 BP 187 EP 206 DI 10.1016/0378-3812(96)03044-0 PG 20 WC Thermodynamics; Chemistry, Physical; Engineering, Chemical SC Thermodynamics; Chemistry; Engineering GA VF368 UT WOS:A1996VF36800013 ER PT J AU Deeter, MN Bon, SM AF Deeter, MN Bon, SM TI Molecular field theory analysis of magneto-optic sensitivity of gallium-substituted yttrium iron garnets SO APPLIED PHYSICS LETTERS LA English DT Article ID SENSORS AB The temperature dependence of the magneto-optic sensitivity of gallium-substituted yttrium iron garnets was measured at 1.3 mu m and compared with a model based on molecular field theory. The model incorporates results of measurements of both the saturation magnetization and saturation Faraday rotation versus temperature. These measurements were analyzed in the context of molecular field theory to extract the fundamental molecular field coefficients and the magneto-optical coefficients as functions of gallium content. The model and direct sensitivity measurements both indicate that the magneto-optic sensitivity of garnet compositions with gallium substitution levels near 0.8 should exhibit a vanishing first-order temperature sensitivity. RP Deeter, MN (reprint author), NATL INST STAND & TECHNOL,DIV OPTOELECTR,325 BROADWAY,BOULDER,CO 80303, USA. RI Deeter, Merritt/O-6078-2016 OI Deeter, Merritt/0000-0002-3555-0518 NR 8 TC 3 Z9 3 U1 2 U2 6 PU AMER INST PHYSICS PI WOODBURY PA CIRCULATION FULFILLMENT DIV, 500 SUNNYSIDE BLVD, WOODBURY, NY 11797-2999 SN 0003-6951 J9 APPL PHYS LETT JI Appl. Phys. Lett. PD JUL 29 PY 1996 VL 69 IS 5 BP 702 EP 704 DI 10.1063/1.117812 PG 3 WC Physics, Applied SC Physics GA UZ024 UT WOS:A1996UZ02400038 ER PT J AU Losert, W Shi, BQ Cummins, HZ Warren, JA AF Losert, W Shi, BQ Cummins, HZ Warren, JA TI Spatial period-doubling instability of dendritic arrays in directional solidification SO PHYSICAL REVIEW LETTERS LA English DT Article ID PRIMARY SPACING SELECTION; GROWTH; ALLOYS AB A directional solidification study of succinonitrile doped with coumarin 152 was performed in which the pulling speed V-P was gradually reduced in small steps. A spatial period-doubling instability was observed when V-P reached 17.4 mu m/s, in good quantitative agreement with the prediction of Warren and Langer [Phys. Rev. A 42, 3518 (1990)]. This experiment, in conjunction with two previous studies, conclusively demonstrates the absence of a dynamical selection mechanism for the interdendritic spacing lambda(1). C1 NIST,MAT SCI & ENGN LAB,DIV MET,GAITHERSBURG,MD 20899. RP Losert, W (reprint author), CUNY CITY COLL,DEPT PHYS,NEW YORK,NY 10031, USA. NR 16 TC 27 Z9 27 U1 2 U2 7 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 0031-9007 J9 PHYS REV LETT JI Phys. Rev. Lett. PD JUL 29 PY 1996 VL 77 IS 5 BP 889 EP 891 DI 10.1103/PhysRevLett.77.889 PG 3 WC Physics, Multidisciplinary SC Physics GA UY952 UT WOS:A1996UY95200025 ER PT J AU Hartten, LM AF Hartten, LM TI Synoptic settings of westerly wind bursts SO JOURNAL OF GEOPHYSICAL RESEARCH-ATMOSPHERES LA English DT Article ID 40-50 DAY OSCILLATION; 1986-87 EL-NINO; TROPICAL PACIFIC; SOUTHERN OSCILLATION; EQUATORIAL PACIFIC; GLOBAL CLIMATE; TOGA COARE; SURFACE; CLOUD; DISTURBANCES AB The morphology of westerly wind bursts (WWBs) during the 1980s is investigated using 1000-mbar winds analyzed by the European Center for Medium-Range Weather Forecasts (ECMWF). The variety of synoptic situations in which WWBs occur are explored so that the dynamics of WWB generation and maintenance can be studied and so that those interested in short- and long-term forecasts of conditions over the equatorial Pacific will have an increased knowledge of those elements associated with WWBs. WWBs are identified by searching for episodes in which the zonal wind was at least 5 m s(-1) over at least 10 degrees longitude for two or more days. This definition, based on surface winds rather than elevated winds or wind anomalies, reflects the impact WWBs have on air/sea interaction processes. The spatial and temporal criteria provide a synoptic-scale envelope for such interactions and mitigate against erroneous analyses. According to these criteria, 131 distinct WWBs occurred during the 1980s. A new two-dimensional classification scheme has been developed; the nine patterns in it describe the nearsurface flow during 90% of these WWBs. A single cyclone or a series of cyclones in one or both hemispheres and several different types of cross-equatorial flow are the major components of the patterns. Only 8% of the bursts were associated with concurrent cyclones in both the northern and southern hemispheres. Four bursts involving cross-equatorial flow are subjected to further study. The flow is decomposed into barotropic and baroclinic parts and into rotational and divergent baroclinic components. One of the bursts was predominantly barotropic and another predominantly baroclinic; the cross-equatorial flow in all four cases was predominantly divergent in nature. The information from these cases, coupled with the typical vertical structures and small meridional length scales associated with the various synoptic patterns, suggests that simple baroclinic models of circulations driven by near-equatorial heating are not adequate to describe the dynamics during WWBs. RP UNIV COLORADO, CIRES, BOULDER NOAA AERON LAB, CAMPUS BOX 216, BOULDER, CO 80309 USA. RI Hartten, Leslie/F-1970-2010 OI Hartten, Leslie/0000-0002-5620-6302 NR 63 TC 35 Z9 35 U1 0 U2 1 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 2169-897X EI 2169-8996 J9 J GEOPHYS RES-ATMOS JI J. Geophys. Res.-Atmos. PD JUL 27 PY 1996 VL 101 IS D12 BP 16997 EP 17019 DI 10.1029/96JD00030 PG 23 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA UZ750 UT WOS:A1996UZ75000009 ER PT J AU Surolia, A Sharon, N Schwarz, FP AF Surolia, A Sharon, N Schwarz, FP TI Thermodynamics of monosaccharide and disaccharide binding to Erythrina corallodendron lectin SO JOURNAL OF BIOLOGICAL CHEMISTRY LA English DT Article ID BEAN PSOPHOCARPUS-TETRAGONOLOBUS; FLUORESCENT-INDICATOR LIGAND; CONCANAVALIN-A; CARBOHYDRATE COMPLEXES; THERMAL-DENATURATION; RIBONUCLEASE-A; PROTEIN; AGGLUTININ; OLIGOSACCHARIDES; ENERGETICS AB Isothermal titration calorimetry measurements of the binding of 2'-fucosyllactose, lactose, N-acetyllactosamine, galactopyranose, 2-acetamido-2-deoxygalactopyranoside, methyl alpha-N-dansylgalactosaminide (Me-alpha-DNS-GalN), methyl alpha-D-galactopyranoside, methyl beta-D-galactopyranoside, and fucose to Erythrina corallodendron lectin (ECorL), a dimer with one binding site per subunit, were performed at 283-286 and 297-299 K. The site binding enthalpies, Delta H-b, with the exception of Me-alpha-DNS-GalN, are the same at both temperatures and range from -47.1 +/- 1.0 kJ mol(-1) for N-acetyllactosamine to -4.4 +/- 0.3 kJ mol(-1) for fucose, and the site binding constants range from 3.82 +/- 0.9 x 10(5) M(-1) for Me-alpha-DNS-GalN at 283.2 K to 0.46 +/- 0.05 x 10(3) M(-1) for fucose at 297.2 K, The binding reactions are mainly enthalpically driven except for fucose and exhibit enthalpy-entropy compensation, The binding enthalpies of the disaccharides are about twice the binding enthalpies of the monosaccharides in contrast to concanavalin A where the binding enthalpies do not double for the disaccharides, Differential scanning calorimetry measurements show that denaturation of the ECorL dimer results in dissociation into its monomer subunits, The binding constants from the increase in denaturation temperature of ECorL in the presence of saccharides are in agreement with values from isothermal titration calorimetry results, The thermal denaturation of ECorL occurs around 333 K, well below the 344-360 K denaturation temperature of other legume lectins of similar size and tertiary structure, undoubtedly due to the difference in its quaternary structure relative to other legume lectins, This is also apparent from the independent unfolding of its two domains. C1 WEIZMANN INST SCI,DEPT MEMBRANE RES & BIOPHYS,IL-76100 REHOVOT,ISRAEL. CTR ADV RES BIOTECHNOL,ROCKVILLE,MD 20850. NIST,ROCKVILLE,MD 20850. RP Surolia, A (reprint author), INDIAN INST SCI,MOLEC BIOPHYS UNIT,BANGALORE 560012,KARNATAKA,INDIA. RI SUROLIA, AVADESHA/C-5442-2009 NR 34 TC 66 Z9 67 U1 0 U2 7 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 JUL 26 PY 1996 VL 271 IS 30 BP 17697 EP 17703 PG 7 WC Biochemistry & Molecular Biology SC Biochemistry & Molecular Biology GA UY935 UT WOS:A1996UY93500019 PM 8663419 ER PT J AU Nashold, R Remington, P Peterson, P Jentzen, J Kapella, R AF Nashold, R Remington, P Peterson, P Jentzen, J Kapella, R TI Heat-wave-related mortality Milwaukee, Wisconsin, July 1995 (Reprinted from MMWR, vol 45, page 505-507, 1996) SO JAMA-JOURNAL OF THE AMERICAN MEDICAL ASSOCIATION LA English DT Reprint C1 WISCONSIN DEPT HLTH & SOCIAL SERV,REGISTRAR VITAL STAT,DIV HLTH,MADISON,WI 53707. MILWAUKEE CTY MED EXAMINERS OFF,MILWAUKEE,WI. NATL WEATHER SERV,CHAMPAIGN,IL. CTR DIS CONTROL,HLTH STUDIES BRANCH,DIV ENVIRONM HAZARDS & HLTH EFFECTS,NATL CTR ENVIRONM HLTH,ATLANTA,GA 30333. CTR DIS CONTROL,SURVEILLANCE & PROGRAMS BRANCH,DIV ENVIRONM HAZARDS & HLTH EFFECTS,ATLANTA,GA 30333. RP Nashold, R (reprint author), WISCONSIN DEPT HLTH & SOCIAL SERV,CTR HLTH STAT,MADISON,WI 53707, USA. NR 7 TC 3 Z9 3 U1 0 U2 0 PU AMER MEDICAL ASSOC PI CHICAGO PA 515 N STATE ST, CHICAGO, IL 60610 SN 0098-7484 J9 JAMA-J AM MED ASSOC JI JAMA-J. Am. Med. Assoc. PD JUL 24 PY 1996 VL 276 IS 4 BP 275 EP 275 PG 1 WC Medicine, General & Internal SC General & Internal Medicine GA UX583 UT WOS:A1996UX58300014 ER PT J AU Hodges, JT Looney, JP vanZee, RD AF Hodges, JT Looney, JP vanZee, RD TI Laser bandwidth effects in quantitative cavity ring-down spectroscopy SO APPLIED OPTICS LA English DT Article; Proceedings Paper CT OSA 1995 Annual Meeting CY 1995 CL PORTLAND, OR SP Opt Soc Amer ID ABSORPTION-MEASUREMENTS; OXYGEN AB We have investigated the effects of laser bandwidth on quantitative cavity ring-down spectroscopy using the 'R transitions of the b(v = 0) <-- X(v = 0) band of molecular oxygen. It is found that failure to account properly for the laser bandwidth leads to systematic errors in the number densities determined from measured ring-down signals. when the frequency-integrated expression for the ring-down signal is fitted and measured laser line shapes are used, excellent agreement between measured and predicted number densities is found. RP Hodges, JT (reprint author), NIST,CHEM SCI & TECHNOL LAB,GAITHERSBURG,MD 20899, USA. RI Hodges, Joseph/B-4578-2009 NR 12 TC 102 Z9 102 U1 1 U2 15 PU OPTICAL SOC AMER PI WASHINGTON PA 2010 MASSACHUSETTS AVE NW, WASHINGTON, DC 20036 SN 0003-6935 J9 APPL OPTICS JI Appl. Optics PD JUL 20 PY 1996 VL 35 IS 21 BP 4112 EP 4116 DI 10.1364/AO.35.004112 PG 5 WC Optics SC Optics GA VA608 UT WOS:A1996VA60800017 PM 21102816 ER PT J AU Lock, JA Hodges, JT AF Lock, JA Hodges, JT TI Far-field scattering of an axisymmetric laser beam of arbitrary profile by an on-axis spherical particle SO APPLIED OPTICS LA English DT Article; Proceedings Paper CT OSA 1995 Annual Meeting CY 1995 CL PORTLAND, OR SP Opt Soc Amer ID LORENZ-MIE THEORY; GAUSSIAN-BEAM; LIGHT; APPROXIMATION; ORDER AB Experimental laser beam profiles often deviate somewhat from the ideal Gaussian shape of the TEM(00) laser mode. In order to take these deviations into account when calculating light scattering, we propose a method for approximating the beam shape coefficients in the partial wave expansion of an experimental laser beam. We then compute scattering by a single dielectric spherical particle placed on the beam's axis using this method and compare our results to laboratory data. Our model calculations fit the laboratory data well. (C) 1996 Optical Society of America C1 NIST,CHEM SCI & TECHNOL LAB,GAITHERSBURG,MD 20899. RP Lock, JA (reprint author), CLEVELAND STATE UNIV,DEPT PHYS,CLEVELAND,OH 44115, USA. RI Hodges, Joseph/B-4578-2009 NR 17 TC 19 Z9 22 U1 0 U2 3 PU OPTICAL SOC AMER PI WASHINGTON PA 2010 MASSACHUSETTS AVE NW, WASHINGTON, DC 20036 SN 0003-6935 J9 APPL OPTICS JI Appl. Optics PD JUL 20 PY 1996 VL 35 IS 21 BP 4283 EP 4290 DI 10.1364/AO.35.004283 PG 8 WC Optics SC Optics GA VA608 UT WOS:A1996VA60800038 PM 21102837 ER PT J AU Maloney, PR Hollenbach, DJ Tielens, AGGM AF Maloney, PR Hollenbach, DJ Tielens, AGGM TI X-ray-irradiated molecular gas .1. Physical processes and general results SO ASTROPHYSICAL JOURNAL LA English DT Article DE atomic processes; infrared, ISM, lines and bands; molecular processes; radiative transfer; X-rays, ISM ID HYDROGEN GAS; PHOTODISSOCIATION REGIONS; INTERSTELLAR GRAINS; INFRARED-EMISSION; SEYFERT-GALAXIES; TIME VARIABILITY; CHARGE-TRANSFER; CROSS-SECTIONS; LINE EMISSION; DENSE CLOUDS AB We have modeled the physical and chemical state of dense (n = 10(3)-10(5) cm(-3)) neutral gas exposed to intense X-ray fluxes and the resultant infrared and submillimeter emission from the irradiated gas. The dominant parameter controlling the state of the gas in these X-ray dissociation regions (XDRs) is the ratio of local X-ray energy deposition rate to gas density; this can be expressed in terms of an effective ionization parameter. The parameter space we model ranges over 5 orders of magnitude in this ionization parameter; the gas physical conditions vary from warm, atomic, and partially ionized (T similar to 10(4) K, molecular hydrogen abundance x(H2) less than or similar to 10(-4), electron abundance x(e) similar to 0.1) to cold, molecular, and neutral (T similar to 20 K, x(H2) approximate to 0.5, x(e) similar to 10(-6)). We thus cover the entire range of parameter space in which X-ray ionization and heating is important and the gas is largely neutral. Although we assume a power law for the incident X-ray flux, most of our results are independent of this assumption and are of general applicability. A wide range of diagnostic atomic and molecular line emission is produced by XDRs, which are luminous sources of infrared and submillimeter lines. This is a consequence of the large column densities (N > 10(22) Cm-2) that hard (E > 1 keV photons are capable of penetrating before being absorbed. Strong emission lines include [Fe II] 1.26 and 1.64 mu m, [O I] 63 mu m, [C II] 158 mu m, [Si II] 35 mu m, and the 2 mu m vibration-rotation lines of H-2, such as the v = 1-0 S(1) line at 2.12 mu m. We discuss diagnostic line ratios for discriminating XDRs from shocks and photodissociation regions. One strong signature of emission from XDRs is the large flux ratio (similar to 0.1) of the major coolant line fluxes (e.g., [O I] 63 mu m) to the bolometric continuum flux. XDRs are likely to be the dominant sources of emission in a range of astrophysical environments, such as molecular clouds within roughly 1 kpc of typical active galactic nuclei. C1 UNIV COLORADO,JOINT INST LAB ASTROPHYS,BOULDER,CO 80309. NATL INST STAND & TECHNOL,BOULDER,CO 80309. NASA,AMES RES CTR,MOFFETT FIELD,CA 94035. RP Maloney, PR (reprint author), UNIV COLORADO,CTR ASTROPHYS & SPACE ASTRON,BOULDER,CO 80309, USA. NR 70 TC 426 Z9 428 U1 0 U2 3 PU UNIV CHICAGO PRESS PI CHICAGO PA 5720 S WOODLAWN AVE, CHICAGO, IL 60637 SN 0004-637X J9 ASTROPHYS J JI Astrophys. J. PD JUL 20 PY 1996 VL 466 IS 1 BP 561 EP 584 DI 10.1086/177532 PN 1 PG 24 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA UW721 UT WOS:A1996UW72100045 ER PT J AU Daniel, JS Schauffler, SM Pollock, WH Solomon, S Weaver, A Heidt, LE Garcia, RR Atlas, EL Vedder, JF AF Daniel, JS Schauffler, SM Pollock, WH Solomon, S Weaver, A Heidt, LE Garcia, RR Atlas, EL Vedder, JF TI On the age of stratospheric air and inorganic chlorine and bromine release SO JOURNAL OF GEOPHYSICAL RESEARCH-ATMOSPHERES LA English DT Article ID NORTHERN-HEMISPHERE; CARBON-DIOXIDE; OZONE; MIDLATITUDES; ATMOSPHERE; WINTER AB We estimate the average transport time from the tropical tropopause to various regions of the northern hemisphere lower stratosphere (stratospheric age) using simultaneous mixing ratio measurements of CFC-115 and CO2 measured by the Whole Air Sampler (WAS) during Airborne Arctic Stratospheric Expedition II (AASE II). Our inferred ages are consistent with those presented in previous studies. We discuss sources of uncertainties that affect age estimates in general, as well as specific uncertainties arising from inferring ages using CO2 and CFC-115 abundances. We infer inorganic chlorine (Cl-y) and bromine (Br-y) at various lower stratospheric locations using the WAS organic chlorine and bromine measurements in combination with modeled tropospheric halocarbon trends and with our estimated ages. Inferred Cl-y and Br-y abundances generally increase with increasing latitude and altitude. For our analyzed locations inside the polar vortex, we estimate a maximum Cl-y abundance of about 2.7 parts per billion by volume (ppbv) and a maximum Br-y abundance of about 13.7 parts per trillion by volume (pptv). The locations of these maxima correspond to an average N2O mixing ratio of about 100 ppbv, and to a fractional dissociation of organic chlorine and bromine of 0.85 and 0.90, respectively. Finally, we discuss the expected future limitations of using CFC-115 to estimate stratospheric age due to the production limitations prescribed by the amendments and adjustments to the Montreal Protocol. C1 NOAA, AERON LAB, BOULDER, CO 80303 USA. NATL CTR ATMOSPHER RES, DIV ATMOSPHER CHEM, BOULDER, CO 80307 USA. RP Daniel, JS (reprint author), UNIV COLORADO, COOPERAT INST RES ENVIRONM SCI, BOULDER, CO 80309 USA. RI Daniel, John/D-9324-2011; Atlas, Elliot/J-8171-2015 NR 29 TC 30 Z9 30 U1 0 U2 1 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 2169-897X J9 J GEOPHYS RES-ATMOS JI J. Geophys. Res.-Atmos. PD JUL 20 PY 1996 VL 101 IS D11 BP 16757 EP 16770 DI 10.1029/96JD01167 PG 14 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA UY275 UT WOS:A1996UY27500006 ER PT J AU Mateer, CL Dutsch, HU Staehelin, J AF Mateer, CL Dutsch, HU Staehelin, J TI Influence of a priori profiles on trend calculations from Umkehr data SO JOURNAL OF GEOPHYSICAL RESEARCH-ATMOSPHERES LA English DT Article ID OZONE; ALGORITHM; SOUNDINGS AB Although the new (1992) ozone profile retrieval algorithm for Umkehr measurements provides much better agreement with ozone sounding results than the old (1964) algorithm, considerable discrepancies remain with respect to ozone trends at different levels in the atmosphere. These discrepancies have been found by the comparison of long-term trends obtained from the Umkehr measurements at Arosa and the ozone balloon soundings at Payerne (Switzerland). It is investigated here whether these obvious discrepancies can be removed by using time-dependent a priori profiles. This procedure is successful only in the lowest part of the atmosphere, below about 19 km. To further explore this problem, synthetic Umkehr observations are calculated from the ozonesonde profiles. Trends are calculated for both the synthetic and actual Umkehr observations. The difference pattern between these Umkehr observation trends is compared with the difference in ozone profile retrieval trends from the synthetic and actual observations. The distinctive difference patterns strongly indicate an inherent disagreement between the Umkehr observations and the ozonesonde profiles. The application of corrections for stratospheric aerosol effects to the Umkehr profiles reduces, but does not eliminate, a discrepancy above 32 km. It is concluded that the discrepancies are due to the constant mixing ratio assumption used in computing the residual ozone above balloon burst level and to the fair-weather bias of Umkehr observations (there are Umkehr observations at Arosa on fewer than 20% of the sonde observation days at Payerne). This sampling difference influences the results for the lower stratosphere. The study furthermore indicates that the ozone trends derived from Umkehr measurements for altitudes above about 32 km are robust for time-dependent changes in the a priori profiles at lower altitudes. Based on the results of this study, we conclude with revised recommendations as to which atmospheric layers should be used for Umkehr trend studies. C1 NOAA, ENVIRONM RES LAB, BOULDER, CO 80803 USA. ETH HONGGERBERG, LAB ATMOSPHER PHYS, CH-8093 ZURICH, SWITZERLAND. NR 17 TC 11 Z9 11 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 JUL 20 PY 1996 VL 101 IS D11 BP 16779 EP 16787 DI 10.1029/95JD03794 PG 9 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA UY275 UT WOS:A1996UY27500008 ER PT J AU Estupinan, JG Raman, S Crescenti, GH Streicher, JJ Barnard, WF AF Estupinan, JG Raman, S Crescenti, GH Streicher, JJ Barnard, WF TI Effects of clouds and haze on UV-B radiation SO JOURNAL OF GEOPHYSICAL RESEARCH-ATMOSPHERES LA English DT Article ID ULTRAVIOLET; OZONE; WAVELENGTHS; SURFACE AB An experiment was conducted over a B-month period in Research Triangle Park, North Carolina, to investigate the effects of clouds and haze on ultraviolet (UV) radiation. Data were collected using a Yankee Environmental Systems UVB-1 pyranometer, an Eppley Laboratory Precision Spectral Pyranometer, and a SCI-TEC Brewer spectrophotometer. Hourly reports of total cloud cover and surface observations of air temperature, dew point temperature, barometric pressure, and visibility from the National Weather Service located at the nearby Raleigh-Durham International Airport were also used in this study. An empirical relationship has been formulated for UV-B attenuation as a function of total solar transmissivity and cloud cover. Cumulus-type clouds were found to attenuate up to 99% of the incoming UV-B radiation during overcast conditions. However, these same clouds were found to produce localized increases of UV-B radiation of up to 27% over timescales less than 1 hour under partly cloudy skies when the direct solar beam was unobstructed. Summer haze was found to attenuate UV-B radiation in the range of 5% to 23% when compared to a clear day in the autumn. In general, total radiation was attenuated more than UV-B radiation under cloudy conditions. C1 N CAROLINA STATE UNIV, DEPT MARINE EARTH & ATMOSPHER SCI, RALEIGH, NC 27695 USA. NOAA, AIR RESOURCES LAB, ATMOSPHER SCI MODELLING DIV, RES TRIANGLE PK, NC 27111 USA. US EPA, NATL EXPOSURE RES LAB, ATMOSPHER PROC RES DIV, RES TRIANGLE PK, NC 27111 USA. NR 28 TC 82 Z9 87 U1 1 U2 9 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 2169-897X J9 J GEOPHYS RES-ATMOS JI J. Geophys. Res.-Atmos. PD JUL 20 PY 1996 VL 101 IS D11 BP 16807 EP 16816 DI 10.1029/96JD01170 PG 10 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA UY275 UT WOS:A1996UY27500011 ER PT J AU Arrivo, SM Heilweil, EJ AF Arrivo, SM Heilweil, EJ TI Conservation of vibrational excitation during hydrogen-bonding reactions SO JOURNAL OF PHYSICAL CHEMISTRY LA English DT Article ID SOLVENT; PREDISSOCIATION; SPECTROSCOPY; COMPLEXES; DYNAMICS; RELAXATION; LIFETIMES; LIQUIDS AB We report novel transient infrared ''tag and probe'' investigations of the equilibrium kinetics and vibrational energy transfer between the free acid Et(3)SiOH and its 1:1 hydrogen-bonded complex with acetonitrile, Et(3)SiOH ... N=CCH3, in dilute (0.1 mol/dm(3) acid) CCl4 solutions at 293 K. Picosecond time-resolved infrared double-resonance spectroscopy measures the vibrational population of the OH-stretching mode (via upsilon = 1 --> 2 absorption) after IR excitation of either the free acid or the homogeneously broadened OH(upsilon = 0 --> 1) absorption of the complex. The free acid and 1:1 complex OH(upsilon = 1) population lifetimes (TI) and equilibrium reaction rate constants affecting hydrogen-bond formation and dissociation are unambiguously determined for this system. Tagged free acid OH(upsilon = 1) leads to complex formation with OH(upsilon = 1) excitation, indicating OH(upsilon = 1) population is maintained during collision and formation of hydrogen bonds. This is the only known example where OH(upsilon = 1) vibrational population of a polyatomic reactant is prepared and that excitation is followed during a condensed-phase bimolecular reaction which leads to an excited hydrogen-bonded product. C1 NATL INST STAND & TECHNOL,OPT TECHNOL DIV,GAITHERSBURG,MD 20899. NR 29 TC 46 Z9 46 U1 0 U2 9 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 SN 0022-3654 J9 J PHYS CHEM-US JI J. Phys. Chem. PD JUL 18 PY 1996 VL 100 IS 29 BP 11975 EP 11983 DI 10.1021/jp960483m PG 9 WC Chemistry, Physical SC Chemistry GA UX961 UT WOS:A1996UX96100022 ER PT J AU Dye, JE Baumgardner, D Gandrud, BW Drdla, K Barr, K Fahey, DW Delnegro, LA Tabazadeh, A Jonsson, HH Wilson, JC Loewenstein, M Podolske, JR Chan, KR AF Dye, JE Baumgardner, D Gandrud, BW Drdla, K Barr, K Fahey, DW Delnegro, LA Tabazadeh, A Jonsson, HH Wilson, JC Loewenstein, M Podolske, JR Chan, KR TI In-situ observations of an Antarctic polar stratospheric cloud: Similarities with Arctic observations SO GEOPHYSICAL RESEARCH LETTERS LA English DT Article ID AEROSOL; GROWTH; WATER AB Measured particle volumes in a type I polar stratospheric cloud near the Antarctic polar vortex during ASHOE/MAESA show that the onset of the cloud occurred near 193 K, 3 degrees colder than nitric acid trihydrate (NAT) saturation. The onset temperature, the smooth increase of volume with decreasing temperature, the inverse correlation of particle volume and enhanced NOy (HNO3 in the particles) with temperature, and comparisons of observations with an equilibrium model of ternary droplet growth all support the notion that much of this type I PSC was ternary solution droplets. This provides confirmation of previous findings in the northern hemisphere. However, the ternary model does not fit the observations in all regions. This may be due to the presence of some solid phase growth in agreement with impactor observations. C1 NOAA,AERON LAB,BOULDER,CO 80303. NASA,AMES RES CTR,MOFFETT FIELD,CA 94035. UNIV DENVER,DENVER,CO 80210. UNIV CALIF LOS ANGELES,DEPT ATMOSPHER SCI,LOS ANGELES,CA 90024. RP Dye, JE (reprint author), NATL CTR ATMOSPHER RES,POB 3000,BOULDER,CO 80307, USA. RI Fahey, David/G-4499-2013 OI Fahey, David/0000-0003-1720-0634 NR 15 TC 33 Z9 33 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 JUL 15 PY 1996 VL 23 IS 15 BP 1913 EP 1916 DI 10.1029/96GL01812 PG 4 WC Geosciences, Multidisciplinary SC Geology GA UY592 UT WOS:A1996UY59200006 ER PT J AU Burnett, CR Burnett, EB AF Burnett, CR Burnett, EB TI The regime of decreased OH vertical column abundances at Fritz Peak Observatory, CO: 1991-1995 SO GEOPHYSICAL RESEARCH LETTERS LA English DT Article ID HYDROXYL AB The 18-year data base for vertical column abundance measurements of atmospheric OH at Fritz Peak Observatory, Colorado (40 degrees N, 105 degrees W), exhibits a relatively abrupt change in seasonal behavior during 1991 through 1995. Late summer through early fall abundances, especially, for each year of the 1991-1995 period are significantly below the comparable seasonal average for 1980-1990. Early morning abundances for August through October at solar zenith angles greater than 45 degrees exibit an average reduction of about 0.8x10(15)/cm(2), which at a solar zenith angle of 60 degrees is a 15% column decrease. C1 NOAA,FRITZ PEAK OBSERV,ROLLINSVILLE,CO 80474. RP Burnett, CR (reprint author), NEW MEXICO INST MIN & TECHNOL,SOCORRO,NM 87801, USA. NR 12 TC 7 Z9 7 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 JUL 15 PY 1996 VL 23 IS 15 BP 1925 EP 1927 DI 10.1029/96GL01811 PG 3 WC Geosciences, Multidisciplinary SC Geology GA UY592 UT WOS:A1996UY59200009 ER PT J AU Dixon, KW Bullister, JL Gammon, RH Stouffer, RJ AF Dixon, KW Bullister, JL Gammon, RH Stouffer, RJ TI Examining a coupled climate model using CFC-11 as an ocean tracer SO GEOPHYSICAL RESEARCH LETTERS LA English DT Article ID ATMOSPHERE MODEL; CHLOROFLUOROMETHANES; WATER AB Anthropogenic CFC-11 dissolved in seawater is used to analyze ocean ventilation simulated in a global coupled air-sea model. Modeled CFC-11 distributions are compared to observations gathered on three Southern Hemisphere research cruises. The total amount of CFC-11 absorbed by the model's Southern Ocean is realistic, though some notable differences in the vertical structure exist. Observed and simulated CFC-11 distributions are qualitatively consistent with the coupled model's predictions that the ocean may delay greenhouse gas-induced warming of surface air temperatures at high southern latitudes. The sensitivity of model-predicted CFC-11 levels in the deep Southern Ocean to the choice of gas exchange parameterization suggests that quantitative assessments of model performance based upon simulated CFC-11 distributions can be limited by air-sea gas flux uncertainties in areas of rapid ocean ventilation. Such sensitivities can complicate the quantitative aspects of CFC-11 comparisons between models and observations, and between different models. C1 NOAA,PACIFIC MARINE ENVIRONM LAB,SEATTLE,WA 98115. UNIV WASHINGTON,DEPT CHEM,SEATTLE,WA 98195. RP Dixon, KW (reprint author), PRINCETON UNIV,NOAA,GEOPHYS FLUID DYNAM LAB,POB 308,PRINCETON,NJ 08542, USA. RI Dixon, Keith/L-7120-2015 OI Dixon, Keith/0000-0003-3044-326X NR 16 TC 23 Z9 24 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 JUL 15 PY 1996 VL 23 IS 15 BP 1957 EP 1960 DI 10.1029/96GL01470 PG 4 WC Geosciences, Multidisciplinary SC Geology GA UY592 UT WOS:A1996UY59200017 ER PT J AU Misra, DN AF Misra, DN TI Adsorption of polyacrylic acids and their sodium salts on hydroxyapatite: Effect of relative molar mass SO JOURNAL OF COLLOID AND INTERFACE SCIENCE LA English DT Article DE adsorption; charge effect Langmuir plot; molecular association; molecular conformation; polyacrylic acids and salts; role of calcium and phosphate ions ID DENTAL POLYMER COMPOSITES; POLY(ACRYLIC ACID); AQUEOUS-SOLUTION; INTERFACIAL PROPERTIES; SURFACE; CALCIUM; FLUORAPATITE; DISSOLUTION; FLUORIDE; ADHESION AB The effect of molar mass on the adsorptive properties of polyacrylic acids and their sodium salts (polymers) has an important bearing on the adhesive mechanisms of restorative resins based on these or similar polymers, The adsorption isotherms of the aqueous solution of polymers were determined on synthetic hydroxyapatite at room temperature to elucidate the role of physico-chemical factors involved in the process. The adsorption of lower molar mass (<90,000) polyacrylic acids shows that the isotherms first rise, reach a maximum, then decrease. In contrast, a higher molar mass (250,000) polyacrylic acids shows no maximum and follows a regular isotherm. The adsorption isotherms of sodium polyacrylates are regular, do not exhibit any maxima, and merge into each other for higher molar mass salts (>60,000), The adsorption is irreversible for the acids as well as for the salts. The concentrations of calcium and phosphate ions were also determined in the filtrates in order to establish any possible correlation with the adsorbed amounts of polymers. The self-association of the polyacrylic molecules by intermolecular hydrogen bonding that may be responsible for the decrease in adsorption at higher concentrations may not play a significant role for higher molar mass acids where individual molecules can fold on themselves as intramolecular hydrogen bonding becomes more dominant. Inter- or intramolecular hydrogen bonding may not play any role in the case of salts because of Coulombic repulsion between the highly charged carboxylate groups. RP Misra, DN (reprint author), NIST,AMER DENT ASSOC HLTH FDN,PAFFENBURGER RES CTR,DIV POLYMERS,GAITHERSBURG,MD 20899, USA. NR 32 TC 36 Z9 37 U1 0 U2 15 PU ACADEMIC PRESS INC JNL-COMP SUBSCRIPTIONS PI SAN DIEGO PA 525 B ST, STE 1900, SAN DIEGO, CA 92101-4495 SN 0021-9797 J9 J COLLOID INTERF SCI JI J. Colloid Interface Sci. PD JUL 15 PY 1996 VL 181 IS 1 BP 289 EP 296 DI 10.1006/jcis.1996.0380 PG 8 WC Chemistry, Physical SC Chemistry GA UV439 UT WOS:A1996UV43900031 ER PT J AU Wanninkhof, R Feely, RA Chen, H Cosca, C Murphy, PP AF Wanninkhof, R Feely, RA Chen, H Cosca, C Murphy, PP TI Surface water fCO(2) in the eastern equatorial Pacific during the 1992-1993 El Nino SO JOURNAL OF GEOPHYSICAL RESEARCH-OCEANS LA English DT Article ID JANUARY-MARCH 1991; SOUTHERN OSCILLATION; CARBON-DIOXIDE; CO2; EVENT; DISTRIBUTIONS; PERIOD; MARINE; OCEAN AB The fugacity of CO2 in surface water (fCO(2W)) was measured in the eastern equatorial Pacific (EEP) during the boreal spring and fall of 1992 and in the spring of 1993. A prolonged El Nino occurred during this period with anomalously warm sea surface temperatures (SST) during the spring of 1992 and 1993. Correspondingly, the fCO(2W) values were lower than historical non-El Nino values at the equator. However, the fCO(2W) in the spring of 1993 was up to 50 mu atm higher than in the spring of 1992, despite similar SSTs. The trend is attributed to the slower response times of factors causing fCO(2W) decrease compared to rapid increase of fCO(2W) by upwelling of cold water with high carbon content and subsequent heating. During the fall of 1992, SSTs south of the equator were 5 degrees C cooler than in the spring, which is indicative of vigorous upwelling of water with high CO, content from below the thermocline. Decreases in fCO(2W) due to net biological productivity and gas exchange take of the order of months, causing the fCO(2W) levels during the spring of 1993 to be elevated compared to the spring of the previous year. Our data and data obtained in 1986 and 1989 along 110 degrees W suggest that fCO(2W) maxima in the equatorial Pacific can be either associated with temperature minima or temperature maxima. Despite the multitude of factors which influence fCO(2W), most of the variance can be accounted for with changes in nitrate and SST. A multilinear regression of fCO(2W) with SST and nitrate for the 1992 data has a standard error in predicted fCO(2W) of 10 mu atm. Air-sea fluxes of CO2 in the EEP were estimated to be 30% higher in the spring of 1993 and 10% higher in the fall of 1992 than in the spring of 1992. C1 NOAA,PACIFIC MARINE ENVIRONM LAB,OCEAN CLIMATE RES DIV,SEATTLE,WA 98115. RP Wanninkhof, R (reprint author), NOAA,ATLANTIC OCEANOG & METEOROL LAB,OCEAN CHEM DIV,COOPERAT INST MARINE ATMOSPHER STUDIES,MIAMI,FL 33149, USA. RI Chen, Hua/B-7664-2014 OI Chen, Hua/0000-0002-9493-6939 NR 38 TC 24 Z9 24 U1 0 U2 1 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 SN 0148-0227 J9 J GEOPHYS RES-OCEANS JI J. Geophys. Res.-Oceans PD JUL 15 PY 1996 VL 101 IS C7 BP 16333 EP 16343 DI 10.1029/96JC01348 PG 11 WC Oceanography SC Oceanography GA UX792 UT WOS:A1996UX79200005 ER PT J AU Mofjeld, HO Gonzalez, FI Eble, MC AF Mofjeld, HO Gonzalez, FI Eble, MC TI Subtidal bottom pressure observed at Axial Seamount in the northeastern continental margin of the Pacific Ocean SO JOURNAL OF GEOPHYSICAL RESEARCH-OCEANS LA English DT Article ID EASTERN NORTH PACIFIC; DE-FUCA RIDGE; SUBINERTIAL MOTIONS; GROUND DEFORMATION; SEA-LEVEL; VARIABILITY; CURRENTS; JUAN; FLUCTUATIONS AB Since September 1987, bottom pressure (BP) has been observed at Axial Seamount (45 degrees 57.5'N, 130 degrees 00.3'W; 1540-m depth), located 450 km off the Oregon Coast on the Juan de Fuca Ridge. Observations from 1987 to 1992 show that subtidal Axial BP is dominated by barotropic 2- to 5-mbar fluctuations with frequencies less than or equal to 1/9 cycles per day (cpd). They are slightly smaller than subtidal BP observed 720 km to the west during the Ocean Storms Experiment and a factor of 2-4 smaller than the subtidal fluctuations of adjusted sea level (ASL) at the coast. For the period September 1987 to July 1988, Axial BP and Ocean Storms BP are significantly coherent(coh(2) greater than or equal to 0.5), except at intraseasonal frequencies (1/100-1/20 cpd) and in a band (1/8-1/6 cpd) of low Axial BP variance. In the coherent frequency bands, the phase relationships between the two BP series suggest independent atmospheric forcing. On the other hand, Axial BP and coastal ASL are not coherent except at the fortnightly tidal frequency. Looking for possible forcing of Axial BP by the curl of the wind stress (curl) over the NE Pacific, data analyses show that Axial BP and curl (derived from European Centre for Medium-Range Weather Forecasts winds) are significantly coherent in only two frequency bands: one band narrowly peaked near 1/9.1 cpd for curl in regions south of Axial Seamount and a 1/5-1/3.5 cpd band for curl in a large region NW of the seamount. In the 1/5-1/3.5 band, Axial BP also has a small-amplitude spectral peak associated with bottom-trapped (baroclinic) currents near Axial Seamount. Remote Axial BP/curl coherence at some frequencies is qualitatively consistent with the local-forcing theory of Lippert and Muller [1995] that attributes the coherence to stable phase relationships and the spatial characteristics of the BP/curl transfer function. However, the Axial BP/curl comparison is inhibited by the lack of accurate estimates of curl within 400 km of the coast. Fully understanding the origins and dynamics of subtidal BP at Axial Seamount will require a knowledge of how the complex topography in the region affects the barotropic and baroclinic responses to atmospheric forcing, as well as the propagation of Rossby and other waves. RP Mofjeld, HO (reprint author), NOAA,PACIFIC MARINE ENVIRONM LAB,7600 SAND POINT WAY NE,BLDG 3,SEATTLE,WA 98115, USA. NR 36 TC 5 Z9 5 U1 0 U2 1 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 SN 0148-0227 J9 J GEOPHYS RES-OCEANS JI J. Geophys. Res.-Oceans PD JUL 15 PY 1996 VL 101 IS C7 BP 16381 EP 16390 DI 10.1029/96JC01451 PG 10 WC Oceanography SC Oceanography GA UX792 UT WOS:A1996UX79200009 ER PT J AU Oey, LY AF Oey, LY TI Flow around a coastal bend: A model of the Santa Barbara Channel eddy SO JOURNAL OF GEOPHYSICAL RESEARCH-OCEANS LA English DT Article AB A steady, equatorward wind stress is applied over a two-layer ocean (infinitely deep lower layer) west of an otherwise straight meridional coast with a right-angle bend. Initial (t approximate to 10 days) response consists of an equatorward current (Kelvin wave) that triggers a cyclone around the bend through viscous production and advection of vorticity, a process akin to eddy shedding in flows without rotation. The response at large times is governed by a Kelvin wave forced by the equatorward weakening of the (assumed positive) wind stress curl, which produces a poleward current near the coast. Application to the Santa Barbara Channel cyclone is discussed, and the cyclone-formation process is further demonstrated with a three-dimensional model with topography and stratification. RP Oey, LY (reprint author), PRINCETON UNIV,PROGRAM ATMOSPHER & OCEAN SCI,SAYRE HALL,FORRESTAL CAMPUS,PRINCETON,NJ 08544, USA. NR 13 TC 20 Z9 20 U1 0 U2 0 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 SN 0148-0227 J9 J GEOPHYS RES-OCEANS JI J. Geophys. Res.-Oceans PD JUL 15 PY 1996 VL 101 IS C7 BP 16667 EP 16682 DI 10.1029/96JC01232 PG 16 WC Oceanography SC Oceanography GA UX792 UT WOS:A1996UX79200029 ER PT J AU DeMaria, M AF DeMaria, M TI The effect of vertical shear on tropical cyclone intensity change SO JOURNAL OF THE ATMOSPHERIC SCIENCES LA English DT Article ID POTENTIAL VORTICITY; HURRICANE; MODEL; INTENSIFICATION; EVOLUTION; ATLANTIC; BALANCE; MOTION; VORTEX AB The effect of vertical shear on tropical cyclone intensity change is usually explained in terms of ''ventilation'' where heat and moisture at upper levels are advected away from the low-level circulation, which inhibits development. A simple two-layer diagnostic balance model is used to provide an alternate explanation of the effect of shear. When the upper-layer wind in the vortex environment differs from that in the lower layer, the potential vorticity(PV) pattern associated with the vortex circulation becomes tilted in the vertical. The balanced mass field associated with the tilted PV pattern requires an increased midlevel temperature perturbation near the vortex center. It is hypothesized that this midlevel warming reduces the convective activity and inhibits the storm development. Previous studies have shown that diabatic heating near the storm center acts to reduce the vertical tilt of the vortex circulation. These studies have also shown that there is an adiabatic process that acts to reduce the vertical tilt of a vortex. The effectiveness of the adiabatic process depends on the Rossby penetration depth, which increases with latitude, horizontal scale, and vortex amplitude. Large-scale analyses from the 1989-1994 Atlantic hurricane seasons are used to show that high-latitude, large, and intense tropical cyclones tend to be less sensitive to the effect of vertical shear than low-latitude, small, and weak storms. C1 NOAA,ATLANTIC OCEANOG & METEOROL LAB,HURRICANE RES DIV,MIAMI,FL 33149. RP DeMaria, M (reprint author), NOAA,TROP PREDICT CTR,11691 SW 17TH ST,MIAMI,FL 33165, USA. RI DeMaria, Mark/F-5583-2010 NR 35 TC 252 Z9 285 U1 2 U2 26 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 JUL 15 PY 1996 VL 53 IS 14 BP 2076 EP 2087 DI 10.1175/1520-0469(1996)053<2076:TEOVSO>2.0.CO;2 PG 12 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA UZ736 UT WOS:A1996UZ73600009 ER PT J AU Li, XD Yin, ZD Wang, Y Zheng, MZ AF Li, XD Yin, ZD Wang, Y Zheng, MZ TI Mossbauer study of the composition fluctuation during spinodal decomposition in a 3.5 GPa Fe-10%Ni-14%Mo-19%Co(wt.%) maraging steel SO MATERIALS SCIENCE AND ENGINEERING A-STRUCTURAL MATERIALS PROPERTIES MICROSTRUCTURE AND PROCESSING LA English DT Letter DE composition fluctuation; Mossbauer spectroscopy; maraging steel ID ALLOYS AB The composition fluctuation during spinodal decomposition in a 3.5 GPa Fe-10%Ni-14%Mo-19%Co (wt.%) maraging steel was studied by Mossbauer spectroscopy. The aging reactions start with the redistribution of atoms, which results in the formation of Fe-Co-rich zones and Ni-Mo-Ti-rich zones at ?he early stages of aging. The redistribution of atoms is fast at the initial stages of aging and then becomes slow. Intermetallic compounds precipitate on the Ni-Mo-Ti-rich zones. C1 HARBIN INST TECHNOL,DEPT MET & TECHNOL,HARBIN 150001,PEOPLES R CHINA. NIST,GAITHERSBURG,MD 20899. RI Li, Xiaodong/B-6530-2008; Zheng, Mingyi/F-9470-2012; OI Zheng, Mingyi/0000-0002-7016-0785; wang, you/0000-0003-0266-0224 NR 15 TC 1 Z9 1 U1 0 U2 1 PU ELSEVIER SCIENCE SA LAUSANNE PI LAUSANNE 1 PA PO BOX 564, 1001 LAUSANNE 1, SWITZERLAND SN 0921-5093 J9 MAT SCI ENG A-STRUCT JI Mater. Sci. Eng. A-Struct. Mater. Prop. Microstruct. Process. PD JUL 15 PY 1996 VL 212 IS 1 BP 182 EP 185 DI 10.1016/0921-5093(96)10210-0 PG 4 WC Nanoscience & Nanotechnology; Materials Science, Multidisciplinary; Metallurgy & Metallurgical Engineering SC Science & Technology - Other Topics; Materials Science; Metallurgy & Metallurgical Engineering GA UY796 UT WOS:A1996UY79600024 ER PT J AU Schneider, M Evenson, KM Johns, JWC AF Schneider, M Evenson, KM Johns, JWC TI Far-infrared continuous-wave laser emission from H2O and from NH3 optically pumped by a CO laser SO OPTICS LETTERS LA English DT Article AB We report what we believe is the first observation of continuous-wave far-infrared laser emission from water vapor and from ammonia optically pumped by a CO laser. (C) 1996 Optical Society of America C1 NATL INST STAND & TECHNOL,BOULDER,CO 80303. NATL RES COUNCIL CANADA,STEACIE INST MOLEC SCI,OTTAWA,ON K1A 0R6,CANADA. NR 8 TC 0 Z9 0 U1 0 U2 0 PU OPTICAL SOC AMER PI WASHINGTON PA 2010 MASSACHUSETTS AVE NW, WASHINGTON, DC 20036 SN 0146-9592 J9 OPT LETT JI Opt. Lett. PD JUL 15 PY 1996 VL 21 IS 14 BP 1038 EP 1039 DI 10.1364/OL.21.001038 PG 2 WC Optics SC Optics GA UW232 UT WOS:A1996UW23200010 PM 19876244 ER PT J AU Butorin, SM Mancini, DC Guo, JH Wassdahl, N Nordgren, J Nakazawa, M Tanaka, S Uozumi, T Kotani, A Ma, Y Myano, KE Karlin, BA Shuh, DK AF Butorin, SM Mancini, DC Guo, JH Wassdahl, N Nordgren, J Nakazawa, M Tanaka, S Uozumi, T Kotani, A Ma, Y Myano, KE Karlin, BA Shuh, DK TI Resonant X-ray fluorescence spectroscopy of correlated systems: A probe of charge-transfer excitations SO PHYSICAL REVIEW LETTERS LA English DT Article ID HOPPING-MATRIX-ELEMENTS; ELECTRONIC-STRUCTURE; CONFIGURATION DEPENDENCE; PHOTOEMISSION SPECTRA; SYNCHROTRON RADIATION; CE COMPOUNDS; ABSORPTION; MODEL; OXIDES; STATES AB X-ray fluorescence spectroscopy with monochromatic photon excitation is presented as a tool for studies of charge-transfer excitations in correlated systems, using CeO2 and UO3 as examples. Ce 4f --> 3d and U 5f --> 3d x-ray fluorescence, with excitation near the 3d thresholds, probes states as eigenvalues for the groundstate Hamiltonian from the Anderson impurity model. Sweeping the excitation energy across 3d absorption edges enhances contributions of different electronic configurations to fluorescence so that observed resonances indicate the charge-transfer origin of the absorption satellites. C1 UNIV UPPSALA, DEPT PHYS, S-75121 UPPSALA, SWEDEN. UNIV TOKYO, INST SOLID STATE PHYS, MINATO KU, TOKYO 106, JAPAN. UNIV OSAKA PREFECTURE, COLL ENGN, SAKAI, OSAKA 593, JAPAN. UNIV WASHINGTON, DEPT PHYS, SEATTLE, WA 98195 USA. PACIFIC NW LAB, MOLEC SCI RES CTR, RICHLAND, WA 99352 USA. CUNY BROOKLYN COLL, DEPT PHYS, BROOKLYN, NY 11210 USA. NATL INST STAND & TECHNOL, GAITHERSBURG, MD 20899 USA. UNIV CALIF BERKELEY, LAWRENCE BERKELEY LAB, DIV CHEM SCI, BERKELEY, CA 94720 USA. NR 31 TC 108 Z9 109 U1 5 U2 31 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 0031-9007 J9 PHYS REV LETT JI Phys. Rev. Lett. PD JUL 15 PY 1996 VL 77 IS 3 BP 574 EP 577 DI 10.1103/PhysRevLett.77.574 PG 4 WC Physics, Multidisciplinary SC Physics GA UW791 UT WOS:A1996UW79100041 ER PT J AU Guelachvili, G Birk, M Borde, CJ Brault, JW Brown, LR Carli, B Cole, ARH Evenson, KM Fayt, A Hausamann, D Johns, JWC Kauppinen, J Kou, Q Maki, AG Rao, KN Toth, RA Urban, W Valentin, A Verges, J Wagner, G Wappelhorst, MH Wells, JS Winnewisser, BP Winnewisser, M AF Guelachvili, G Birk, M Borde, CJ Brault, JW Brown, LR Carli, B Cole, ARH Evenson, KM Fayt, A Hausamann, D Johns, JWC Kauppinen, J Kou, Q Maki, AG Rao, KN Toth, RA Urban, W Valentin, A Verges, J Wagner, G Wappelhorst, MH Wells, JS Winnewisser, BP Winnewisser, M TI High resolution wavenumber standards for the infrared (Reprinted from Pure Appl Chem, Vol 68, pg 193-208, 1996) SO SPECTROCHIMICA ACTA PART A-MOLECULAR AND BIOMOLECULAR SPECTROSCOPY LA English DT Reprint ID HETERODYNE FREQUENCY MEASUREMENTS; (CO)-C-12-O-16 LASER TRANSITIONS; ACCURATE ROTATIONAL-CONSTANTS; CARBONYL SULFIDE; LINE POSITIONS; MOLECULAR-CONSTANTS; MU-M; CALIBRATION TABLES; FUNDAMENTAL-BAND; DIODE-LASER AB The calibration of high resolution infrared spectra is generally more precise than accurate. This is the case even when they are recorded with Fourier transform interferometers. The present document aims at improving the accuracy of wavenumber measurements in the infrared by recommending a selection of spectral lines as wavenumber standards for absolute calibration in the range from about 4 to about 7000 cm(-1). The uncertainties of these wavenumber standards range from +/-1 x 10(-3) to +/-1 x 10(-6) cm(-1). Sources of frequency standards, on which the wavenumber determinations are based, are also given. C1 DLR,INST OPTOELECTR,D-82234 WESSELING,GERMANY. UNIV PARIS 13,PHYS LASERS LAB,F-93430 VILLETANEUSE,FRANCE. NOAA,AERON LAB,BOULDER,CO 80303. CALTECH,JET PROP LAB,PASADENA,CA 91109. CNR,IST RIC ONDE ELETTROMAGNET,I-50127 FLORENCE,ITALY. UNIV WESTERN AUSTRALIA,SCH CHEM,NEDLANDS,WA 6009,AUSTRALIA. NATL INST STAND & TECHNOL,DIV TIME & FREQUENCY,BOULDER,CO 80303. UNIV CATHOLIQUE LOUVAIN,MOL SPECT LAB,B-1348 LOUVAIN,BELGIUM. NATL RES COUNCIL CANADA,STEACIE INST MOLEC SCI,OTTAWA,ON K1A 0R6,CANADA. TURKU UNIV,DEPT APPL PHYS,FIN-20500 TURKU,FINLAND. UNIV WASHINGTON,DEPT CHEM,SEATTLE,WA 98195. OHIO STATE UNIV,DEPT PHYS,COLUMBUS,OH 43210. UNIV BONN,INST ANGEW PHYS,D-53115 BONN,GERMANY. UNIV PARIS 06,CNRS,UPR 136,PHYS MOLEC LAB,F-75252 PARIS,FRANCE. LAB AIMEE COTTON,F-91405 ORSAY,FRANCE. UNIV GIESSEN,PHYS CHEM INST,D-35392 GIESSEN,GERMANY. RP Guelachvili, G (reprint author), UNIV PARIS 11,CNRS,PHYS MOLEC LAB,UPR 136,BATIMENT 350,F-91405 ORSAY,FRANCE. NR 96 TC 10 Z9 10 U1 0 U2 4 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD, ENGLAND OX5 1GB SN 0584-8539 J9 SPECTROCHIM ACTA A JI Spectroc. Acta Pt. A-Molec. Biomolec. Spectr. PD JUL 15 PY 1996 VL 52 IS 7 BP 717 EP 732 DI 10.1016/0584-8539(96)01717-5 PG 16 WC Spectroscopy SC Spectroscopy GA UV249 UT WOS:A1996UV24900001 ER PT J AU Wiese, WL AF Wiese, WL TI A new reference data table for carbon, nitrogen and oxygen spectra SO SPECTROCHIMICA ACTA PART B-ATOMIC SPECTROSCOPY LA English DT Article ID OSCILLATOR STRENGTH MEASUREMENTS; FOIL-LASER METHOD; NEUTRAL NITROGEN; LIFETIME MEASUREMENTS; VACUUM-ULTRAVIOLET; N-II; LINES RP Wiese, WL (reprint author), NIST, GAITHERSBURG, MD 20899 USA. NR 11 TC 1 Z9 1 U1 0 U2 0 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 JUL 15 PY 1996 VL 51 IS 8 BP 775 EP 777 DI 10.1016/0584-8547(96)01490-5 PG 3 WC Spectroscopy SC Spectroscopy GA UX672 UT WOS:A1996UX67200001 ER PT J AU Winchester, MR Marcus, RK AF Winchester, MR Marcus, RK TI Investigations of self-absorption in a radio-frequency glow discharge device SO SPECTROCHIMICA ACTA PART B-ATOMIC SPECTROSCOPY LA English DT Article DE Fourier transform spectrometry; radio-frequency glow discharge; self-absorption ID EMISSION CHARACTERISTICS; SPECTROMETRY AB The self-absorption behavior of a radio-frequency glow discharge atomic emission device has been studied with Fourier transform spectrometry. Using a resonant transition of a major element, it has been shown that for this device the potential for self-absorption is severe, and no analytically useful discharge conditions that significantly reduce that potential were found. In fact, it is unlikely that such conditions can be found, even with a more exhaustive study. Therefore, there is no compelling reason to alter the discharge conditions that would typically be employed for analyses with the device. Based on the potential for self-absorption, it is advisable to use non-resonant, rather than resonant, transitions of major elements for analytical purposes. On the other hand, the use of resonant transitions of minor or trace elements appears to be free from any significant danger of analytical error induced by self-absorption. However, further studies are needed to validate this conclusion over a wider range of analytes, transitions, sample types, and discharge conditions. Owing to the fact that self-absorption is influenced by the subtleties of the design of a glow discharge device, such as the placement of a vacuum port, these results should not be assumed to be wholly applicable to other glow discharge devices. C1 CLEMSON UNIV,HOWARD L HUNTER CHEM LAB,DEPT CHEM,CLEMSON,SC 29634. RP Winchester, MR (reprint author), NIST,CHEM SCI & TECHNOL LAB,DIV ANALYT CHEM,GAITHERSBURG,MD 20899, USA. NR 21 TC 8 Z9 8 U1 0 U2 1 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD, ENGLAND OX5 1GB SN 0584-8547 J9 SPECTROCHIM ACTA B JI Spectroc. Acta Pt. B-Atom. Spectr. PD JUL 15 PY 1996 VL 51 IS 8 BP 839 EP 850 DI 10.1016/0584-8547(96)01473-5 PG 12 WC Spectroscopy SC Spectroscopy GA UX672 UT WOS:A1996UX67200005 ER PT J AU Keeling, CD Chin, JFS Whorf, TP AF Keeling, CD Chin, JFS Whorf, TP TI Increased activity of northern vegetation inferred from atmospheric CO2 measurements SO NATURE LA English DT Article ID CARBON-DIOXIDE; RECORD; CLIMATE; ICE AB THROUGHOUT the Northern Hemisphere the concentration of atmospheric carbon dioxide rises in winter and declines in summer, mainly in response to the seasonal growth in land vegetation(1-4). In the far north the amplitude of the seasonal cycle, peak to trough, is between 15 and 20 parts per million by volume(5). The annual amplitude diminishes southwards to about 3 p.p.m. near the Equator, owing to the diminishing seasonality of plant activity towards the tropics. In spite of atmospheric mixing processes, enough spatial variability is retained in the seasonal cycle of CO2 to reveal considerable regional detail in seasonal plant activity(6). Here we report that the annual amplitude of the seasonal CO2 cycle has increased by 20%, as measured in Hawaii, and by 40% in the Arctic, since the early 1960s. These increases are accompanied by phase advances of about 7 days during the declining phase of the cycle, suggesting a lengthening of the growing season. In addition, the annual amplitudes show maxima which appear to reflect a sensitivity to global warming episodes that peaked in 1981 and 1990. We propose that the amplitude increases reflect increasing assimilation of CO2 by land plants in response to climate changes accompanying recent rapid increases in temperature. C1 NOAA,CMDL,MAUNA LOA OBSERV,HILO,HI 96721. RP Keeling, CD (reprint author), UNIV CALIF SAN DIEGO,SCRIPPS INST OCEANOG,LA JOLLA,CA 92093, USA. NR 21 TC 667 Z9 750 U1 14 U2 137 PU MACMILLAN MAGAZINES LTD PI LONDON PA 4 LITTLE ESSEX STREET, LONDON, ENGLAND WC2R 3LF SN 0028-0836 J9 NATURE JI Nature PD JUL 11 PY 1996 VL 382 IS 6587 BP 146 EP 149 DI 10.1038/382146a0 PG 4 WC Multidisciplinary Sciences SC Science & Technology - Other Topics GA UW672 UT WOS:A1996UW67200043 ER PT J AU Jones, KM Julienne, PS Lett, PD Phillips, WD Tiesinga, E Williams, CJ AF Jones, KM Julienne, PS Lett, PD Phillips, WD Tiesinga, E Williams, CJ TI Measurement of the atomic Na(3P) lifetime and of retardation in the interaction between two atoms bound in a molecule SO EUROPHYSICS LETTERS LA English DT Article ID POTENTIAL CURVES; RESONANCE LINES; STATES; SPECTROSCOPY AB From molecular spectroscopy of the Na-2 purely long range O-g(-), state we determine the Na(3P) lifetime and measure the predicted but previously unobserved effect of retardation in the interaction between two atoms. Our lifetime tau(P-3/2) = 16.230(16) ns helps to remove a longstanding discrepancy between experiment and theory. Electron cloud overlap is unimportant in the 0(g)(-) state (R > 55 alpha(0)) and the spectrum is calculated, ab initio, from atomic properties. By measuring the binding energies the 120 MHz correction due to retardation of the resonant-dipole R(-3) interaction is confirmed. C1 WILLIAMS COLL,WILLIAMSTOWN,MA 01267. UNIV CHICAGO,JAMES FRANCK INST,CHICAGO,IL 60637. RP Jones, KM (reprint author), NIST,PHYS A 167,ATOM PHYS DIV,GAITHERSBURG,MD 20899, USA. RI Williams, Carl/B-5877-2009; Julienne, Paul/E-9378-2012 OI Julienne, Paul/0000-0002-5494-1442 NR 33 TC 115 Z9 115 U1 0 U2 3 PU EDITIONS PHYSIQUE PI LES ULIS CEDEX PA Z I DE COURTABOEUF AVE 7 AV DU HOGGAR, BP 112, 91944 LES ULIS CEDEX, FRANCE SN 0295-5075 J9 EUROPHYS LETT JI Europhys. Lett. PD JUL 10 PY 1996 VL 35 IS 2 BP 85 EP 90 DI 10.1209/epl/i1996-00536-9 PG 6 WC Physics, Multidisciplinary SC Physics GA UY406 UT WOS:A1996UY40600002 ER PT J AU Lee, SH Broholm, C Aeppli, G Ramirez, AP Perring, TG Carlile, CJ Adams, M Jones, TJL Hessen, B AF Lee, SH Broholm, C Aeppli, G Ramirez, AP Perring, TG Carlile, CJ Adams, M Jones, TJL Hessen, B TI Spin-glass and non-spin-glass features of a geometrically frustrated magnet SO EUROPHYSICS LETTERS LA English DT Article ID KAGOME ANTIFERROMAGNET; TRIANGULAR-LATTICE; ORDER; FLUCTUATIONS; SRCR8GA4O19; DISORDER; DILUTION; SYSTEM AB We use neutron scattering to show that the low-temperature, short-range ordered spin configuration in the geometrically frustrated magnet SrCr(9p)Ga(12-9)pO(19) (p = 0.92(5)) is composed of small groups of spins whose dipole moments cancel. The local magnetic fluctuation spectrum, chi ''(omega), vanishes approximately in proportion to omega for HBAR omega < 0.5 meV, distinguishing this magnet from conventional spin glasses which display a featureless continuum of excited states. We argue that this behavior results from the absence of local, low-energy excitations in the zero-spin clusters from which the frozen spin configuration is composed. C1 NEC CORP LTD,PRINCETON,NJ 08540. NIST,GAITHERSBURG,MD 20899. AT&T BELL LABS,MURRAY HILL,NJ 07974. RUTHERFORD APPLETON LAB,ISIS FACIL,DIDCOT OX11 0QX,OXON,ENGLAND. ROYAL DUTCH SHELL LABS,NL-1003 AA AMSTERDAM,NETHERLANDS. RP Lee, SH (reprint author), JOHNS HOPKINS UNIV,DEPT PHYS & ASTRON,BALTIMORE,MD 21218, USA. RI Broholm, Collin/E-8228-2011 OI Broholm, Collin/0000-0002-1569-9892 NR 30 TC 58 Z9 58 U1 1 U2 10 PU EDITIONS PHYSIQUE PI LES ULIS CEDEX PA Z I DE COURTABOEUF AVE 7 AV DU HOGGAR, BP 112, 91944 LES ULIS CEDEX, FRANCE SN 0295-5075 J9 EUROPHYS LETT JI Europhys. Lett. PD JUL 10 PY 1996 VL 35 IS 2 BP 127 EP 132 DI 10.1209/epl/i1996-00543-x PG 6 WC Physics, Multidisciplinary SC Physics GA UY406 UT WOS:A1996UY40600009 ER PT J AU Nadal, ME Kleiber, PD Lineberger, WC AF Nadal, ME Kleiber, PD Lineberger, WC TI Photofragmentation of mass-selected ICI-(CO2)(n) cluster ions: Solvation effects on the structure and dynamics of the ionic chromophore SO JOURNAL OF CHEMICAL PHYSICS LA English DT Article ID ELECTRON-TRANSFER REACTIONS; PROTON-TRANSFER; INFRARED-SPECTROSCOPY; CHARGE-TRANSFER; PHOTOELECTRON-SPECTROSCOPY; RECOMBINATION DYNAMICS; AMMONIA CLUSTERS; WATER CLUSTERS; POLAR-SOLVENT; PHOTODISSOCIATION AB Photofragmentation studies at 644 nm and 740 nm of ICI-(CO2)(n) cluster ions (n=0-8) have been carried out in a tandem time-of-flight mass spectrometer. Photodissociation of these cluster ions at a wavelength at which bare ICl- produces only I- results in the formation of three classes of fragment ions: I-, Cl-, and ICl- based clusters. The I- based clusters correspond to the direct photoproduct in which a Cl atom has escaped the cluster ion. The ICl- and Cl- based clusters are a result of a nonadiabatic electronic transition to the ground state mediated by the solvent. The relative importance of these photofragment channels strongly depends on the cluster ion size. An ICl- caged product is first observed for ICl-(CO2)(2), increasing rapidly to a maximum at n approximate to 6 and then decreasing. This caging efficiency is dramatically different from the I-2(-)(CO2)(n) cluster ions where complete caging was observed for 16 solvent molecules. The Cl- photofragment channel increases smoothly for the cluster size range studied and becomes the dominant channel for n=8. The relative yields of the ICl- and Cl- based products reflect the extent to which solvation influences the photodissociation pathways of ICl-. (C) 1996 American Institute of Physics. C1 UNIV COLORADO, JILA, BOULDER, CO 80309 USA. NATL INST STAND & TECHNOL, BOULDER, CO 80309 USA. UNIV IOWA, DEPT PHYS & ASTRON, IOWA CITY, IA 52242 USA. RP UNIV COLORADO, DEPT CHEM & BIOCHEM, BOULDER, CO 80309 USA. NR 65 TC 67 Z9 67 U1 0 U2 5 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 JUL 8 PY 1996 VL 105 IS 2 BP 504 EP 514 DI 10.1063/1.471904 PG 11 WC Chemistry, Physical; Physics, Atomic, Molecular & Chemical SC Chemistry; Physics GA UV310 UT WOS:A1996UV31000016 ER PT J AU Hobbie, EK Han, CC AF Hobbie, EK Han, CC TI Lattice model of a hydrogen-bonded polymer blend SO JOURNAL OF CHEMICAL PHYSICS LA English DT Article ID THERMODYNAMICS; SYSTEMS; BEHAVIOR; KINETICS AB A mean-field lattice model is used to investigate some possible aspects of the low-temperature behavior of a lower critical solution temperature (LCST) polymer blend made miscible by a dilute distribution of a hydrogen-bonding comonomer. The nature of the binding interaction is examined for both a random comonomer distribution and for the case of identically end-modified chains. For the latter case, competition between the interaction responsible for the immiscibility of the homopolymer components and the attraction due to hydrogen bonding leads to a stable intermediate phase. For random distributions, polydispersity in the binding interaction restricts this intermediate phase to an extremely narrow window in reduced temperature, consistent with a ''smeared'' transition. The free-energy landscape contains local minima separated by energy barriers. (C) 1996 American Institute of Physics. C1 NIST,GAITHERSBURG,MD 20899. RI Hobbie, Erik/C-8269-2013 NR 26 TC 15 Z9 15 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 JUL 8 PY 1996 VL 105 IS 2 BP 738 EP 748 DI 10.1063/1.471929 PG 11 WC Chemistry, Physical; Physics, Atomic, Molecular & Chemical SC Chemistry; Physics GA UV310 UT WOS:A1996UV31000039 ER PT J AU Weida, MJ Sperhac, JM Nesbitt, DJ AF Weida, MJ Sperhac, JM Nesbitt, DJ TI Sublimation dynamics of CO2 thin films: A high resolution diode laser study of quantum state resolved sticking coefficients. SO JOURNAL OF CHEMICAL PHYSICS LA English DT Article ID GAS-PHASE COLLISIONS; SOLID CARBON-DIOXIDE; RAPID DESORPTION; ABSORPTION-SPECTROSCOPY; SURFACE INTERACTIONS; DESORBING MOLECULES; INFRARED-SPECTRA; MU-M; DISTRIBUTIONS; NO AB Nascent quantum states of CO2 subliming from CO2 thin films at rates of 1 to 10(3) monolayers (ML) per second are probed via direct infrared absorption of the nu(3) asymmetric stretch with a frequency ramped diode laser. The high spectral resolution (Delta nu approximate to 15 MHz) of the diode laser and the use of polarization modulation techniques permit individual rotational, vibrational, translational, and even M(J) degrees of freedom of the subliming flux to be studied with quantum state resolution. Measured rotational and nu(2) bend vibrational distributions indicate that the molecules sublime from the surface in a Boltzmann distribution characterized by the thin him temperature T-s. Similarly, the velocity distributions parallel to the;surface are well described by a Maxwell velocity distribution at T-s, as determined by high resolution Doppler analysis of the individual rovibrational line shapes. The M(J) distribution of subliming rotational states is probed via polarization modulation methods; no alignment is detected within experimental sensitivity. This places an upper limit on the anisotropy in the rotational distribution of \n(perpendicular to)/n(parallel to)--1\<0.02, where n(perpendicular to)/n(parallel to) is the ratio of molecules with J perpendicular vs parallel to the surface normal. By virtue of the direct absorption technique, the. absolute sublimation rates from the surface can be obtained from the measured column integrated densities. Via detailed balance, these fluxes are compared with equilibrium vapor pressure measurements to retrieve the absolute sticking coefficients'S for gas phase CO2 impinging on a solid phase CO2 thin film. For sublimation rates <10(3) ML/s, the data indicate S=1.0+/-0.2, irrespective of quantum state, rotational alignment, and tangential velocity component. For sublimation rates >10(3) ML/s; the onset of a mild supersonic expansion is observed, with post-desorption collisions cooling the rotational temperature by as much as 15 K below T-s. Modeling of the gas-surface interaction using realistic CO2-CO2 pair potentials demonstrates that the gas-surface potential is relatively ''soft'' and highly corrugated, which promotes efficient translational and rotational energy transfer to the surface. The scattering analysis also suggests that nonequilibrium quantum state distributions in the subliming flux are not expected for translational and rotational energies less than or comparable to the binding energy of CO2 to the surface. (C) 1996 American Institute of Physics. C1 UNIV COLORADO, NATL INST STAND & TECHNOL, QUANTUM PHYS DIV, BOULDER, CO 80309 USA. UNIV COLORADO, DEPT CHEM & BIOCHEM, BOULDER, CO 80309 USA. RP Weida, MJ (reprint author), UNIV COLORADO, JILA, BOULDER, CO 80309 USA. NR 75 TC 20 Z9 20 U1 1 U2 10 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 JUL 8 PY 1996 VL 105 IS 2 BP 749 EP 766 DI 10.1063/1.472814 PG 18 WC Chemistry, Physical; Physics, Atomic, Molecular & Chemical SC Chemistry; Physics GA UV310 UT WOS:A1996UV31000040 ER PT J AU Fine, J Szymonski, M Kolodziej, J Yoshitake, M Franzreb, K AF Fine, J Szymonski, M Kolodziej, J Yoshitake, M Franzreb, K TI Collisional deexcitation at ion-bombarded surfaces - Reply SO PHYSICAL REVIEW LETTERS LA English DT Letter RP Fine, J (reprint author), NIST,SURFACE & MICROANAL SCI DIV,GAITHERSBURG,MD 20899, USA. NR 7 TC 4 Z9 4 U1 0 U2 0 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 0031-9007 J9 PHYS REV LETT JI Phys. Rev. Lett. PD JUL 8 PY 1996 VL 77 IS 2 BP 409 EP 409 DI 10.1103/PhysRevLett.77.409 PG 1 WC Physics, Multidisciplinary SC Physics GA UV480 UT WOS:A1996UV48000057 ER PT J AU Subramanian, MA Toby, BH Ramirez, AP Marshall, WJ Sleight, AW Kwei, GH AF Subramanian, MA Toby, BH Ramirez, AP Marshall, WJ Sleight, AW Kwei, GH TI Colossal magnetoresistance without Mn3+/Mn4+ double exchange in the stoichiometric pyrochlore Tl2Mn2O7 SO SCIENCE LA English DT Article ID DIFFRACTION AB Structural analysis from powder neutron and single-crystal x-ray diffraction data for a sample of the Tl2Mn2O7 pyrochlore, which exhibits colossal magnetoresistance (CMR), shows no deviations from ideal stoichiometry. This analysis gives an Mn-O distance of 1.90 angstroms, which is significantly shorter than the Mn-O distances (1.94 to 2.00 angstroms) observed in phases based on LaMnO3 perovskites that exhibit CMR, Both results in Tl2Mn2O7 indicate oxidation states very close to Tl-2 + Mn24+O7. Thus, Tl2Mn2O7 has neither mixed valence for a double-exchange magnetic interaction nor a Jahn-Teller cation such as Mn3+, both of which were thought to have an important function in CMR materials. An alternate mechanism for CMR in Tl2Mn2O7 based on magnetic ordering driven by superexchange and strong spin-fluctuation scattering above the Curie temperature is proposed here. C1 NATL INST STAND & TECHNOL,DIV REACTOR RADIAT,GAITHERSBURG,MD 20899. AT&T BELL LABS,LUCENT TECHNOL,MURRAY HILL,NJ 07974. OREGON STATE UNIV,DEPT CHEM,CORVALLIS,OR 97331. LAWRENCE LIVERMORE NATL LAB,DEPT CHEM & MAT SCI,LIVERMORE,CA 94550. RP Subramanian, MA (reprint author), DUPONT CO INC,CENT RES & DEV,EXPTL STN,WILMINGTON,DE 19880, USA. RI Toby, Brian/F-3176-2013 OI Toby, Brian/0000-0001-8793-8285 NR 30 TC 252 Z9 254 U1 0 U2 21 PU AMER ASSOC ADVANCEMENT SCIENCE PI WASHINGTON PA 1200 NEW YORK AVE, NW, WASHINGTON, DC 20005 SN 0036-8075 J9 SCIENCE JI Science PD JUL 5 PY 1996 VL 273 IS 5271 BP 81 EP 84 DI 10.1126/science.273.5271.81 PG 4 WC Multidisciplinary Sciences SC Science & Technology - Other Topics GA UV478 UT WOS:A1996UV47800041 ER PT J AU Shoute, LCT Mittal, JP Neta, P AF Shoute, LCT Mittal, JP Neta, P TI Fluoride elimination upon reaction of pentafluoroaniline with e(aq)(-), H, and OH radicals in aqueous solution SO JOURNAL OF PHYSICAL CHEMISTRY LA English DT Article ID INTRAMOLECULAR ELECTRON-TRANSFER; ABSOLUTE RATE CONSTANTS; LASER FLASH-PHOTOLYSIS; ANION RADICALS; GAMMA-RADIOLYSIS; MATRIX-ISOLATION; DEHALOGENATION; PERFLUOROBENZENE; RESONANCE; DECAFLUOROBENZOPHENONE AB Reduction of pentafluoroaniline (PFA) leads to rapid fluoride elimination to form the aminotetrafluorophenyl radical. This radical undergoes rapid intramolecular electron transfer from the amino group to the phenyl radical site and protonates at the latter site to form the tetrafluoroaniline radical cation or its deprotonated form (pK(a) = 2.3). Oxidizing radicals such as SO4.-, N-3(.), and Cl-2(.-) oxidize PFA to the pentafluoroaniline radical cation. The pK(a) = 1.9 of the pentafluoroaniline radical cation is 3.6 units lower than that expected from the substituent effects of fluorine atoms. Addition of OH to PFA is followed by rapid HF elimination to yield the aminotetrafluorophenoxyl radical. In acidic solution, however, the reaction of OH leads to formation of the pentafluoroaniline radical cation. Fluoride elimination upon reduction and upon OH addition to PFA was confirmed by determination of fluoride ion yield. C1 INDIAN INST SCI,JAWAHARLAL NEHRU CTR ADV SCI RES,BANGALORE 560012,KARNATAKA,INDIA. NATL INST STAND & TECHNOL,PHYS & CHEM PROPERTIES DIV,GAITHERSBURG,MD 20899. RP Shoute, LCT (reprint author), BHABHA ATOM RES CTR,DIV CHEM,BOMBAY 400085,MAHARASHTRA,INDIA. NR 61 TC 10 Z9 10 U1 0 U2 4 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 SN 0022-3654 J9 J PHYS CHEM-US JI J. Phys. Chem. PD JUL 4 PY 1996 VL 100 IS 27 BP 11355 EP 11359 DI 10.1021/jp960876l PG 5 WC Chemistry, Physical SC Chemistry GA UV312 UT WOS:A1996UV31200024 ER PT J AU Santer, BD Taylor, KE Wigley, TML Johns, TC Jones, PD Karoly, DJ Mitchell, JFB Oort, AH Penner, JE Ramaswamy, V Schwarzkopf, MD Stouffer, RJ Tett, S AF Santer, BD Taylor, KE Wigley, TML Johns, TC Jones, PD Karoly, DJ Mitchell, JFB Oort, AH Penner, JE Ramaswamy, V Schwarzkopf, MD Stouffer, RJ Tett, S TI A search for human influences on the thermal structure of the atmosphere SO NATURE LA English DT Article ID HEMISPHERE TEMPERATURE TRENDS; CARBON-DIOXIDE; CLIMATE CHANGE; GREENHOUSE; MODEL; GASES; CO2 AB The observed spatial patterns of temperature change in the free atmosphere from 1963 to 1987 are similar to those predicted by state-of-the-art climate models incorporating various combinations of changes in carbon dioxide, anthropogenic sulphate aerosol and stratospheric ozone concentrations. The degree of pattern similarity between models and observations increases through this period. It is likely that this trend is partially due to human activities, although many uncertainties remain, particularly relating to estimates of natural variability. C1 LAWRENCE LIVERMORE NATL LAB, DIV ATMOSPHER SCI, LIVERMORE, CA 94550 USA. NATL CTR ATMOSPHER RES, BOULDER, CO 80307 USA. METEOROL OFF, HADLEY CTR CLIMATE PREDICT & RES, BRACKNELL RG12 2SY, BERKS, ENGLAND. UNIV E ANGLIA, CLIMAT RES UNIT, NORWICH NR4 7TJ, NORFOLK, ENGLAND. MONASH UNIV, COOPERAT RES CTR SO HEMISPHERE METEOROL, CLAYTON, VIC 3168, AUSTRALIA. PRINCETON UNIV, NOAA, GEOPHYS FLUID DYNAM LAB, PRINCETON, NJ 08542 USA. RP Santer, BD (reprint author), LAWRENCE LIVERMORE NATL LAB, PROGRAM CLIMATE MODEL DIAG & INTERCOMPARISON, LIVERMORE, CA 94550 USA. RI Wigley, Tom/B-4705-2008; Jones, Philip/C-8718-2009; Taylor, Karl/F-7290-2011; Karoly, David/C-8262-2011; Santer, Benjamin/F-9781-2011; Tett, Simon/B-1504-2013; Penner, Joyce/J-1719-2012 OI Jones, Philip/0000-0001-5032-5493; Taylor, Karl/0000-0002-6491-2135; Karoly, David/0000-0002-8671-2994; Tett, Simon/0000-0001-7526-560X; NR 59 TC 304 Z9 317 U1 6 U2 62 PU NATURE PUBLISHING GROUP PI LONDON PA MACMILLAN BUILDING, 4 CRINAN ST, LONDON N1 9XW, ENGLAND SN 0028-0836 J9 NATURE JI Nature PD JUL 4 PY 1996 VL 382 IS 6586 BP 39 EP 46 DI 10.1038/382039a0 PG 8 WC Multidisciplinary Sciences SC Science & Technology - Other Topics GA UV473 UT WOS:A1996UV47300046 ER PT J AU Neubauer, CM Jennings, HM Garboczi, EJ AF Neubauer, CM Jennings, HM Garboczi, EJ TI A three-phase model of the elastic and shrinkage properties of mortar SO ADVANCED CEMENT BASED MATERIALS LA English DT Article DE cement; concrete; drying shrinkage; elastic properties; finite element; interfacial transition zone; mortars ID INTERFACIAL ZONE; CEMENT PASTE; COMPOSITE-MATERIALS; SIMULATION; CONCRETE; MODULI AB Mortar and concrete are composite materials with overall properties that are influenced by the arrangement and characteristics of each constituent in the microstructure. Elastic shrinkage, like other properties of mortar and concrete, must be described by a three-phase model: aggregate, bulk cement paste, and interfacial transition zone (ITZ) cement paste. A simple two-dimensional digital-image-based model of a mortar is developed based on the hard core/soft shell percolation model. Specific attention is given to the properties of the ITZ between cement past and aggregate. The elastic shrinkage properties of this model are computed numerically, using a specialized finite-element technique. The effects of varying the elastic moduli and shrinkage properties of the ITZ and bulk cement paste are examined in parameter studies, both analytically, for low aggregate content, and numerically, for arbitrary aggregate content. Special attention is given to the effect that the topology of the ITZ has on overall shrinkage. A comparison is made between model predictions and the limited available experimental results (0.35 w/c, 65% hydration), assuming an ITZ width of 20 mu m. Based on this comparison, this paper introduces the prediction that the Young's modulus of the ITZ is one third to one half of the modulus for bulk cement paste and that the unrestrained shrinkage of the ITZ material is close to the shrinkage of bulk cement paste when both are averaged over a 20-mu m ITZ. This finding is supported by further analysis of a three-dimensional microstructural model of cement paste. C1 NORTHWESTERN UNIV,DEPT CIVIL ENGN,EVANSTON,IL 60208. NORTHWESTERN UNIV,DEPT MAT SCI & ENGN,EVANSTON,IL 60208. NIST,GAITHERSBURG,MD 20899. RI Jennings, Hamlin/B-7006-2009 NR 46 TC 36 Z9 44 U1 1 U2 8 PU ELSEVIER SCIENCE INC PI NEW YORK PA 655 AVENUE OF THE AMERICAS, NEW YORK, NY 10010 SN 1065-7355 J9 ADV CEM BASED MATER JI Adv. Cem. Based Mater. PD JUL PY 1996 VL 4 IS 1 BP 6 EP 20 DI 10.1016/1065-7355(96)00024-7 PG 15 WC Construction & Building Technology; Materials Science, Multidisciplinary SC Construction & Building Technology; Materials Science GA UR150 UT WOS:A1996UR15000002 ER PT J AU Siewert, TA Dube, WR Fitting, DW AF Siewert, TA Dube, WR Fitting, DW TI Solidification sensing using high-energy X-ray diffraction SO ADVANCED MATERIALS & PROCESSES LA English DT Article C1 Natl Inst Stand & Technol, Div Mat Reliabil, Boulder, CO 80303 USA. RP Siewert, TA (reprint author), Natl Inst Stand & Technol, Div Mat Reliabil, 325 Broadway, Boulder, CO 80303 USA. RI Dube, William/I-1658-2013 OI Dube, William/0000-0003-1286-4087 NR 0 TC 0 Z9 0 U1 0 U2 1 PU ASM INTERNATIONAL PI MATERIALS PARK PA SUBSCRIPTIONS SPECIALIST CUSTOMER SERVICE, MATERIALS PARK, OH 44073-0002 USA SN 0882-7958 J9 ADV MATER PROCESS JI Adv. Mater. Process. PD JUL PY 1996 VL 150 IS 1 BP 23 EP 25 PG 3 WC Materials Science, Multidisciplinary SC Materials Science GA V2907 UT WOS:000168855000003 ER PT J AU Allor, RL Jahanmir, S AF Allor, RL Jahanmir, S TI Current problems and future directions for ceramic machining SO AMERICAN CERAMIC SOCIETY BULLETIN LA English DT Article AB Ceramic machining must be elevated from an art to a science if ceramic components are to be used in high-volume applications. C1 NATL INST STAND & TECHNOL,GAITHERSBURG,MD 20899. RP Allor, RL (reprint author), FORD MOTOR CO,SCI RES,DEARBORN,MI 48121, USA. NR 10 TC 32 Z9 33 U1 0 U2 3 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 JUL PY 1996 VL 75 IS 7 BP 40 EP 43 PG 4 WC Materials Science, Ceramics SC Materials Science GA UW954 UT WOS:A1996UW95400008 ER PT J AU Williams, PA Rose, AH Lee, KS Conrad, DC Day, GW Hale, PD AF Williams, PA Rose, AH Lee, KS Conrad, DC Day, GW Hale, PD TI Optical, thermo-optic, electro-optic, and photoelastic properties of bismuth germanate (Bi4Ge3O12) SO APPLIED OPTICS LA English DT Article DE bismuth germanate; electro-optic; refractive index; strain optic; stress optic; temperature dependence; thermal expansion ID CRYSTALS; VOLTAGE; SENSORS AB To assess the suitability of bismuth germanate as an electro-optic material for high precision applications, we have confirmed and extended previous data on its refractive index, electro-optic tensor element r(41), and thermal expansion coefficient. In addition, we have measured the thermo-optic coefficient dn/dT, the temperature dependence of the electro-optic coefficient, and the stress-optic tensor elements. From the stress-optic tensor elements and previously published data, we have computed the strain-optic tensor elements. The index of refraction is given, to a good approximation, by the single-term Sellmeier equation, n(2) - 1 = s(0) lambda(02)/[1 - (lambda(0)/lambda)(2)], with s(0) = 95.608 mu m(-2) and lambda(0) = 0.1807 mu m. The thermo-optic coefficient is 3.9 x 10(-5)/degrees C at 632.8 nm and 3.5 x 10(-5)/degrees C at 1152.3 nm. The electro-optic tensor element varies between approximately 1.05 and 1.11 pm/V over the spectral range of 550-1000 nm; its normalized effective change with temperature is approximately 1.54 x 10(-4)/degrees C. The thermal expansion coefficient is 6.3 x 10(-6)/degrees C over the range 15-125 degrees C. Values of the stress-optic tensor elements are q(11) - q(12) = -2.995 x 10(-13) m(2)/N and q(44) = -0.1365 x 10(-12) m(2)/N. The strain-optic tensor elements are p(11) - p(12) = -0.0266 and p(44) = -0.0595. (C) 1996 Optical Society of America. RP Williams, PA (reprint author), NATL INST STAND & TECHNOL,DIV OPTOELECTR,815,BOULDER,CO 80303, USA. RI Hale, Paul/B-1737-2013 NR 24 TC 61 Z9 66 U1 0 U2 15 PU OPTICAL SOC AMER PI WASHINGTON PA 2010 MASSACHUSETTS AVE NW, WASHINGTON, DC 20036 SN 0003-6935 J9 APPL OPTICS JI Appl. Optics PD JUL 1 PY 1996 VL 35 IS 19 BP 3562 EP 3569 DI 10.1364/AO.35.003562 PG 8 WC Optics SC Optics GA UW460 UT WOS:A1996UW46000034 PM 21102749 ER PT J AU Hanssen, LM AF Hanssen, LM TI Effects of non-Lambertian surfaces on integrating sphere measurements SO APPLIED OPTICS LA English DT Article ID MONTE-CARLO METHOD; EMISSIVITIES; CAVITIES; FIELD AB The effects of non-Lambertian scattering of the interior wall of an integrating sphere are examined through a sphere simulation model. The model employs Monte Carlo techniques. A sphere used for measurement of directional-hemispherical reflectance is modeled. The simulation allows sphere wall scattering to vary from perfectly Lambertian to perfectly specular in steps. The results demonstrate that significant measurement error can result as the scattering deviates from the Lambertian ideal. The error is found to be a strong function of the wall reflectance value as well: it is minimized for reflectances approaching 1.0 and increases as the reflectance value decreases to the minimum value examined of 0.5. The magnitudes of the errors associated with non-Lambertian scattering are also shown to be relatively independent of the specific field of view of the detector used in the measurement. RP Hanssen, LM (reprint author), NATL INST STAND & TECHNOL,OPT TECHNOL DIV,GAITHERSBURG,MD 20899, USA. NR 14 TC 14 Z9 16 U1 0 U2 3 PU OPTICAL SOC AMER PI WASHINGTON PA 2010 MASSACHUSETTS AVE NW, WASHINGTON, DC 20036 SN 0003-6935 J9 APPL OPTICS JI Appl. Optics PD JUL 1 PY 1996 VL 35 IS 19 BP 3597 EP 3606 DI 10.1364/AO.35.003597 PG 10 WC Optics SC Optics GA UW460 UT WOS:A1996UW46000038 PM 21102753 ER PT J AU Colle, R Zimmerman, BE AF Colle, R Zimmerman, BE TI Ni-63 half-life: A new experimental determination and critical review SO APPLIED RADIATION AND ISOTOPES LA English DT Article ID COUNTING EFFICIENCY; STANDARDIZATION; DECAY AB The Ni-63 half-life has been determined to be 101.06 +/- 1.97 a based on three independent measurements, conducted over the past 27 years, of the massic activity of gravimetrically-related Ni-63 sources. The Ni-63 assays were performed initially (in 1968) by microcalorimetry using an assumed mean beta(-) energy per decay, and subsequently (in 1984 and 1995) by 4 pi beta liquid scintillation spectrometry with H-3-standard efficiency tracing. The present result is the first and only determination of the Ni-63 half-life which is based on actually following the radioactive decay of Ni-63. All previously reported determinations were derived from specific activity evaluations. These earlier determinations have been scrutinizingly reviewed as part of this work. Some of these previous values can be revised in lieu of more recent nuclear data and on consideration of the experimental details. Based on a critical evaluation of the extant data set, a Ni-63 half-life value of T = 101.1 +/- 1.4 a is recommended. Copyright (C) 1996 Elsevier Science Ltd RP Colle, R (reprint author), NIST,PHYS LAB,GAITHERSBURG,MD 20899, USA. NR 60 TC 14 Z9 14 U1 1 U2 1 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD, ENGLAND OX5 1GB SN 0969-8043 J9 APPL RADIAT ISOTOPES JI Appl. Radiat. Isot. PD JUL PY 1996 VL 47 IS 7 BP 677 EP 691 DI 10.1016/0969-8043(96)00021-8 PG 15 WC Chemistry, Inorganic & Nuclear; Nuclear Science & Technology; Radiology, Nuclear Medicine & Medical Imaging SC Chemistry; Nuclear Science & Technology; Radiology, Nuclear Medicine & Medical Imaging GA UZ297 UT WOS:A1996UZ29700011 ER PT J AU Sievering, H Rusch, D Marquez, L AF Sievering, H Rusch, D Marquez, L TI Nitric acid, particulate nitrate and ammonium in the continental free troposphere: Nitrogen deposition to an alpine tundra ecosystem SO ATMOSPHERIC ENVIRONMENT LA English DT Article DE deposition; ecosystem; nitrogen; nitric acid; tundra; tropospheric ID NIWOT-RIDGE; FRONT RANGE; FOREST; COLORADO; NO2; USA AB Atmospheric sampling of nitric acid vapor, particulate nitrate and ammonium has been ongoing at a 3540 m a.s.l. alpine tundra site on Niwot Ridge, Colorado, since January, 1993. These nitrogen (N) species data, in conjunction with meteorological data, N data at a 3020 m a.s.l. subalpine site, and back-trajectory information, show that over 90% of the sampling was obtained under free tropospheric but, apparently, N-enriched conditions. Seasonal concentration and estimated N dry deposition trends are presented. Dry plus wet atmospheric N loading is found to provide 2.5-3 kg N ha(-1) of new, available N to tundra plants during the growing season (mid-May to mid-September), of which 50%, or more, is dry deposited. During the eight-month, nongrowing season about 5 kg N ha(-1) is wet plus dry deposited to the aggrading snowpack or dormant tundra plants. Up to half of this nongrowing season N loading is made available to growing tundra plants during snowmelt. Thus, a total of 3-5 kg N ha(-1) is annually made available to tundra plants by atmospheric deposition of, primarily, anthropogenically derived N. This annual input of new, available N to nutrient N-limited tundra plants may be compared with the dominant pathway for plant N availability at Niwot Ridge-net mineralization of 10-12 kg N ha(-1) yr(-1) recycled through the soil. The ratio of atmospheric N deposition to net N mineralization, presently approaching 0.5, is higher at the Niwot Ridge alpine tundra ecosystem than at most other ecosystems in the continental U.S. C1 UNIV COLORADO,INST ARCTIC & ALPINE RES,BOULDER,CO 80309. NOAA,CLIMATE MODELING & DIAGNOST LAB,BOULDER,CO. RP Sievering, H (reprint author), UNIV COLORADO,CTR ENVIRONM SCI,CAMPUS BOX 136,POB 173364,DENVER,CO 80217, USA. NR 41 TC 54 Z9 54 U1 0 U2 6 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD, ENGLAND OX5 1GB SN 1352-2310 J9 ATMOS ENVIRON JI Atmos. Environ. PD JUL PY 1996 VL 30 IS 14 BP 2527 EP 2537 DI 10.1016/1352-2310(95)00463-7 PG 11 WC Environmental Sciences; Meteorology & Atmospheric Sciences SC Environmental Sciences & Ecology; Meteorology & Atmospheric Sciences GA UK363 UT WOS:A1996UK36300007 ER PT J AU Crawford, TL Dobosy, RJ Dumas, EJ AF Crawford, TL Dobosy, RJ Dumas, EJ TI Aircraft wind measurement considering lift-induced upwash SO BOUNDARY-LAYER METEOROLOGY LA English DT Article ID ATMOSPHERIC-TURBULENCE MEASUREMENTS; INDUCED FLOW DISTORTION; PROBE; FLUX AB Flow distortion is a universal consideration in the measurement of wind. Usually the distortion results from deflection of the flow by the support. Instruments mounted on airplanes, however, experience an additional deflection associated with lift, which changes rapidly and continuously during flight. In front of the airplane, this deflection appears as upwash. Characteristic upwash contamination ranges from 0.5 to 2.5 ms(-1), depending on wing loading, flight speed, and forward distance from the wing to the measurement location. On pressure-radome installations the distance from the wing is usually small and the potential for upwash contamination large. Sensors mounted at the end of long probes attached to smaller airplanes with light wing loading are less susceptible to upwash contamination. Since wing loading also depends on the local vertical wind velocity the upwash velocity is directly correlated with vertical wind velocity. Generally, empirical corrections are derived from flight tests. We develop a simple method from principles of aerodynamics which explains these corrections in terms of upwash. The applicability of our approach to moderate upwash is demonstrated with data collected from the NOAA Long-EZ research airplane. More severe upwash conditions require a more sophisticated correction beyond the scope of this paper, but basically derived from the same principles. RP Crawford, TL (reprint author), NOAA,AIR RESOURCES LAB,ATMOSPHER TURBULENCE & DIFFUS DIV,POB 2456,OAK RIDGE,TN 37831, USA. RI Dobosy, Ronald/C-3303-2016; Dumas, Edward/C-6669-2016 OI Dobosy, Ronald/0000-0001-8399-8774; Dumas, Edward/0000-0002-9154-9052 NR 15 TC 26 Z9 26 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 JUL PY 1996 VL 80 IS 1-2 BP 79 EP 94 DI 10.1007/BF00119012 PG 16 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA VR824 UT WOS:A1996VR82400004 ER PT J AU Chantler, CT Deslattes, RD Henins, A Hudson, LT AF Chantler, CT Deslattes, RD Henins, A Hudson, LT TI Flat and curved crystal spectrography for mammographic X-ray sources SO BRITISH JOURNAL OF RADIOLOGY LA English DT Article ID BRAGG GEOMETRY; BENT CRYSTALS; DIFFRACTION AB The demand for improved spectral understanding of mammographic X-ray sources and non-invasive voltage calibration of such sources has led to research into applications using curved crystal spectroscopy. Recent developments and the promise of improved precision and control are described. Analytical equations are presented to indicate effects of errors and alignment problems in the flat and curved crystal systems. These are appropriate for all detection systems. Application to and testing of spectrographic detection (using standard X-ray film) is presented. Suitable arrangements exist which can be used to measure X-ray tube voltages well below 1 kV precision in the operating range of 20-35. kV. C1 NATL INST STAND & TECHNOL,GAITHERSBURG,MD 20899. RP Chantler, CT (reprint author), UNIV MELBOURNE,SCH PHYS,PARKVILLE,VIC 3052,AUSTRALIA. RI Chantler, Christopher/D-4744-2013 OI Chantler, Christopher/0000-0001-6608-0048 NR 12 TC 23 Z9 23 U1 1 U2 1 PU BRITISH INST RADIOLOGY PI LONDON PA 36 PORTLAND PLACE, LONDON, ENGLAND W1N 4AT SN 0007-1285 J9 BRIT J RADIOL JI Br. J. Radiol. PD JUL PY 1996 VL 69 IS 823 BP 636 EP 649 PG 14 WC Radiology, Nuclear Medicine & Medical Imaging SC Radiology, Nuclear Medicine & Medical Imaging GA UX074 UT WOS:A1996UX07400009 PM 8696701 ER PT J AU Bullock, LH Godcharles, MF Crabtree, RE AF Bullock, LH Godcharles, MF Crabtree, RE TI Reproduction of yellowedge grouper, Epinephelus flavolimbatus, from the eastern Gulf of Mexico SO BULLETIN OF MARINE SCIENCE LA English DT Article ID LIFE-HISTORY; SERRANIDAE; GROWTH; AGE; GAG C1 NOAA, NATL MARINE FISHERIES SERV, ST PETERSBURG, FL 33702 USA. RP Bullock, LH (reprint author), FLORIDA MARINE RES INST, DEPT ENVIRONM PROTECT, 100 8TH AVE SE, ST PETERSBURG, FL 33701 USA. NR 18 TC 14 Z9 15 U1 1 U2 2 PU ROSENSTIEL SCH MAR ATMOS SCI PI MIAMI PA 4600 RICKENBACKER CAUSEWAY, MIAMI, FL 33149 USA SN 0007-4977 J9 B MAR SCI JI Bull. Mar. Sci. PD JUL PY 1996 VL 59 IS 1 BP 216 EP 224 PG 9 WC Marine & Freshwater Biology; Oceanography SC Marine & Freshwater Biology; Oceanography GA VB343 UT WOS:A1996VB34300015 ER PT J AU Zrnic, DS AF Zrnic, DS TI Weather radar polarimetry-trends toward operational applications SO BULLETIN OF THE AMERICAN METEOROLOGICAL SOCIETY LA English DT Article AB This is a version of a speech presented at the 27th Conference on Radar Meteorology. Relative advantages of polarimetry are contrasted with the advantages accrued by the introduction of radar into meteorology and by the addition of Doppler measurements. A description of present interests as perceived by the author follows, and possible future trends are suggested. RP Zrnic, DS (reprint author), NOAA,NATL SEVERE STORMS LAB,1313 HALLEY CIRCLE,NORMAN,OK 73069, USA. NR 7 TC 16 Z9 16 U1 0 U2 1 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 JUL PY 1996 VL 77 IS 7 BP 1529 EP 1534 DI 10.1175/1520-0477(1996)077<1529:WRPTTO>2.0.CO;2 PG 6 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA UZ042 UT WOS:A1996UZ04200006 ER PT J AU Rotunno, R Pietrafesa, LJ Allen, JS Colman, BR Dorman, CM Kreitzberg, CW Lord, SJ McPhee, MG Mellor, GL Mooers, CNK Niiler, PP Pielke, RA Powell, MD Rogers, DP Smith, JD Xie, LA AF Rotunno, R Pietrafesa, LJ Allen, JS Colman, BR Dorman, CM Kreitzberg, CW Lord, SJ McPhee, MG Mellor, GL Mooers, CNK Niiler, PP Pielke, RA Powell, MD Rogers, DP Smith, JD Xie, LA TI Coastal meteorology and oceanography: Report of the third prospectus development team of the US weather research program to NOAA and NSF SO BULLETIN OF THE AMERICAN METEOROLOGICAL SOCIETY LA English DT Editorial Material AB U.S. Weather Research Program (USWRP) prospectus development teams (PDTs) are small groups of scientists that are convened by the USWRP lead scientist on a one-time basis to discuss critical issues and to provide advice related to future directions of the program. PDTs are a principal source of information for the Science Advisory Committee, which is a standing committee charged with the duty of making recommendations to the Program Office based upon overall program objectives. PDT-1 focused on theoretical issues, and PDT-2, on observational issues; PDT-3 is the first of several to focus on more specialized topics. PDT-3 was convened to identify forecasting problems related to U.S. coastal weather and oceanic conditions, and to suggest likely solution strategies. There were several overriding themes that emerged from the discussion. First, the lock of data in and over critical regions of the ocean, particularly in the atmospheric boundary layer, acid the upper-ocean mixed layer were identified as major impediments to coastal weather prediction. Strategies for data collection acid dissemination, as well as new instrument implementation, were discussed. Second, fundamental knowledge of air-sea fluxes and boundary layer structure in situations where there is significant mesoscale variability in the atmosphere and ocean is needed. Companion field studies and numerical prediction experiments were discussed. Third, research prognostic models suggest that future operational forecast models pertaining to coastal weather will be high resolution and site specific, and will properly treat effects of local coastal geography, orography, and ocean state. The view was expressed that the exploration of coupled air-sea models of the coastal zone would be a particularly fruitful area of research. PDT-3 felt that forecasts of land-impacting tropical cyclones, Great Lakes-affected weather, and coastal cyclogenesis, in particular, would benefit from such coordinated modeling and field efforts. Fourth, forecasting for Arctic coastal zones is limited by our understanding of how sea ice forms. The importance of understanding air-sea fluxes and boundary layers in the presence of ice formation was discussed. Finally, coastal flash flood forecasting via hydrologic models is limited by the present accuracy of measured and predicted precipitation and storm surge events. Strategies for better ways to improve the latter were discussed. C1 NATL CTR ATMOSPHER RES,BOULDER,CO 80307. N CAROLINA STATE UNIV,RALEIGH,NC 27695. OREGON STATE UNIV,CORVALLIS,OR 97331. NATL WEATHER SERV,SEATTLE,WA. NOAA,SEATTLE,WA. SAN DIEGO STATE UNIV,SAN DIEGO,CA 92182. DREXEL UNIV,PHILADELPHIA,PA 19104. NATL CTR ENVIRONM PREDICT,WASHINGTON,DC. MCPHEE RES CO,NACHES,WA. PRINCETON UNIV,PRINCETON,NJ 08544. UNIV MIAMI,ROSENSTIEL SCH MARINE & ATMOSPHER SCI,MIAMI,FL 33149. UNIV CALIF SAN DIEGO,SCRIPPS INST OCEANOG,LA JOLLA,CA 92093. COLORADO STATE UNIV,FT COLLINS,CO 80523. NOAA,HURRICANE RES DIV,MIAMI,FL. US GEOL SURVEY,BOULDER,CO. RI Pielke, Roger/A-5015-2009; Powell, Mark/I-4963-2013 OI Powell, Mark/0000-0002-4890-8945 NR 8 TC 9 Z9 9 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 JUL PY 1996 VL 77 IS 7 BP 1578 EP 1585 PG 8 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA UZ042 UT WOS:A1996UZ04200010 ER PT J AU WongNg, W White, GS Freiman, SW Lindsay, CG AF WongNg, W White, GS Freiman, SW Lindsay, CG TI Calculated potential for water enhanced crack growth in silicon SO COMPUTATIONAL MATERIALS SCIENCE LA English DT Article ID SURFACES; CHEMISORPTION; CORROSION; SILICATES; HYDROGEN; SOLIDS AB Ab initio molecular orbital calculations have been performed on the model molecules Si8H17OH (taking into consideration of the crack wall species -OH and -H) for the crack-tip strain simulation study of silicon and its reaction with water. The calculated equilibrium structure of silicon using a 6-31G** basis set agreed well with experimental data. It was found that, regardless of the manner strain was applied, the values of net charge on the two crack-tip Si atoms are similar and that both become slightly more positive as strain increases. In addition to this absence of polarization of the crack-tip Si-Si bond under strain, steric hindrance also inhibited the approach of the water molecule to the Si-Si crack tip region. These calculations explain why moisture does not enhance crack-growth via chemical reaction in Si, which is different from that observed in silica. C1 NIST,DIV CERAM,GAITHERSBURG,MD 20899. NR 34 TC 8 Z9 8 U1 0 U2 0 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0927-0256 J9 COMP MATER SCI JI Comput. Mater. Sci. PD JUL PY 1996 VL 6 IS 1 BP 63 EP 70 DI 10.1016/0927-0256(96)00022-5 PG 8 WC Materials Science, Multidisciplinary SC Materials Science GA VF389 UT WOS:A1996VF38900005 ER PT J AU Chang, Y Golmie, N Su, D AF Chang, Y Golmie, N Su, D TI Interoperability between EFCI and ER switch mechanisms for ABR traffic in an ATM network SO COMPUTER COMMUNICATIONS LA English DT Article DE interoperability; ATM networks; traffic management; flow control AB The rate-based flow control mechanism in Asynchronous Transfer Mode (ATM) networks controls the transmission rate of Available Bit Rate (ABR) traffic sources, based on feedback information contained in the Resource Management (RM) cells coming from the destination and/or the network switching nodes. While the source and destination end systems behavior is fully described in the ATM Forum Traffic Management Specification, the network switch mechanism is implementation dependent. Since there is a variety of algorithms an ATM switch vendor can choose from, different performance characteristics are expected. This paper investigates the interoperability issues in terms of network performance and fairness of bandwidth allocation when an ATM network consists of switches using different rate control mechanisms, namely, the Explicit Forward Congestion Indication (EFCI) mode and the Explicit Rate (ER) mechanism. Simulation results show that these algorithms will interoperate as long as the switch implementation conforms to the end system behavior for congestion notification and usage of Rh? cells. Moreover, the location of an ER switch in a given topology might be critical to solving the ''beat-down'' phenomenon, where traffic passing through a larger number of switches might get less bandwidth than single hop traffic. C1 NATL INST STAND & TECHNOL,HIGH SPEED NETWORKS GRP,GAITHERSBURG,MD 20899. NR 8 TC 2 Z9 3 U1 0 U2 0 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0140-3664 J9 COMPUT COMMUN JI Comput. Commun. PD JUL PY 1996 VL 19 IS 8 BP 653 EP 658 DI 10.1016/S0140-3664(96)01098-5 PG 6 WC Computer Science, Information Systems; Engineering, Electrical & Electronic; Telecommunications SC Computer Science; Engineering; Telecommunications GA VJ633 UT WOS:A1996VJ63300005 ER PT J AU Olsson, F Petersson, NA AF Olsson, F Petersson, NA TI Stability of interpolation on overlapping grids SO COMPUTERS & FLUIDS LA English DT Article ID DIFFERENTIAL-EQUATIONS AB The stability of interpolation for one-dimensional overlapping grids is considered. The Cauchy-problem for a second-order accurate centered finite difference approximation of u(t) = u(x) is analyzed on the semi-discrete level. The existence of generalized eigenvalues is demonstrated for some rare overlap parameters, in which cases the discretization of the corresponding strip problem is found to be unstable. It is demonstrated that the stability can be recovered by adding artificial dissipation to the equation. Numerical experiments on the strip problem show that when a second-order dissipation is used, the amount of dissipation necessary to cancel the spurious growth is O(h(2)) in the absence of generalized eigenvalues and O(h) in their presence, where h is the grid size. It is also demonstrated that the accuracy is improved by using a fourth-order dissipation. Copyright (C) 1996 Elsevier Science Ltd. C1 CHALMERS UNIV TECHNOL,HYDROMECH DEPT,S-41296 GOTHENBURG,SWEDEN. RP Olsson, F (reprint author), NOAA,ENVIRONM RES LABS,FSL,COOPERAT INST RES ATMOSPHERE,325 BROADWAY,BOULDER,CO 80303, USA. NR 16 TC 15 Z9 15 U1 0 U2 0 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD, ENGLAND OX5 1GB SN 0045-7930 J9 COMPUT FLUIDS JI Comput. Fluids PD JUL PY 1996 VL 25 IS 6 BP 583 EP 605 DI 10.1016/0045-7930(96)00020-5 PG 23 WC Computer Science, Interdisciplinary Applications; Mechanics SC Computer Science; Mechanics GA VE447 UT WOS:A1996VE44700004 ER PT J AU PenaMora, F Hussein, K Sriram, RD AF PenaMora, F Hussein, K Sriram, RD TI CAIRO: A system for facilitating communication in a distributed collaborative engineering environment SO COMPUTERS IN INDUSTRY LA English DT Article; Proceedings Paper CT 4th IEEE Workshop on Enabling Technologies - Infrastructure for Collaborative Enterprises (WETICE 95) CY APR 20-22, 1995 CL BERKELEY SPRINGS, WV SP IEEE DE conference management; collaboration; multimedia synchronization; conference control; floor control ID SUPPORT AB Conference management is a critical component of a collaborative engineering effort. This paper describes CAIRO (Collaborative Agent Interaction control and synchROnization system), a system for managing participants in a distributed conference. We have drawn from various models of group interaction and social communications theory in order to develop CAIRO. The CAIRO system provides both media synchronization, i.e. insuring that all information conveyed from one participant to another is synchronized, and agent synchronization, i.e. insuring effective structuring and control of a distributed conference. C1 MIT,DEPT CIVIL & ENVIRONM ENGN,INTELLIGENT ENGN SYST LAB,CAMBRIDGE,MA 02139. NIST,MFG SYST INTEGRAT DIV,GAITHERSBURG,MD 20899. NR 17 TC 4 Z9 4 U1 1 U2 1 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0166-3615 J9 COMPUT IND JI Comput. Ind. PD JUL PY 1996 VL 29 IS 1-2 BP 37 EP 50 DI 10.1016/0166-3615(95)00053-4 PG 14 WC Computer Science, Interdisciplinary Applications SC Computer Science GA UW002 UT WOS:A1996UW00200005 ER PT J AU Garboczi, EJ Bentz, DP AF Garboczi, EJ Bentz, DP TI Modelling of the microstructure and transport properties of concrete SO CONSTRUCTION AND BUILDING MATERIALS LA English DT Article DE microstructure; multi-scale; percolation ID CEMENT-BASED MATERIALS; PORTLAND-CEMENT; PERCOLATION; COMPOSITES; POROSITY; MORTARS AB Theoretical understanding of how the properties and performance of cement-based materials relate to microstructure is complicated by the large range of relevant size scales. Processes occurring in the nanometre-sized gel pores ultimately affect the performance of these materials at the structural level of metres and larger. One approach to alleviating this complication is the development of a suite of models, consisting of individual digital-image-based structural models for the calcium silicate hydrate gel at the nanometre level, the hydrated cement paste at the micrometre level, and a mortar or concrete at the millimetre to metre level. Computations performed at one level provide input properties to be used in simulations of performance at the next higher level. This methodology is demonstrated for the property of ionic diffusivity in saturated concrete. in addition, the ideas of percolation theory are shown to unify microstructure and many physical phenomena at various length scales in concrete. C1 NIST,BLDG & FIRE RES LAB,GAITHERSBURG,MD 20899. NR 33 TC 81 Z9 85 U1 2 U2 17 PU BUTTERWORTH-HEINEMANN LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD, OXON, ENGLAND OX5 1GB SN 0950-0618 J9 CONSTR BUILD MATER JI Constr. Build. Mater. PD JUL PY 1996 VL 10 IS 5 BP 293 EP 300 DI 10.1016/0950-0618(94)00019-0 PG 8 WC Construction & Building Technology; Engineering, Civil; Materials Science, Multidisciplinary SC Construction & Building Technology; Engineering; Materials Science GA VA056 UT WOS:A1996VA05600002 ER PT J AU Delcroix, T Henin, C Porte, V Arkin, P AF Delcroix, T Henin, C Porte, V Arkin, P TI Precipitation and sea-surface salinity in the tropical Pacific Ocean SO DEEP-SEA RESEARCH PART I-OCEANOGRAPHIC RESEARCH PAPERS LA English DT Article ID OUTGOING LONGWAVE RADIATION; WESTERN EQUATORIAL PACIFIC; SCALE PRECIPITATION; SATELLITE DATA; MIXED LAYER; RAINFALL; VARIABILITY; MODEL; CLIMATOLOGIES; MOISTURE AB Monthly sea-surface salinity (SSS) and precipitation (P) in the tropical Pacific region are examined for the 1974-1989 period. The SSS data are derived mainly from water sample measurements obtained from a ship-of-opportunity program, and the rainfall data are derived from satellite observations of outgoing longwave radiation. The mean and standard deviation patterns of SSS and P exhibit good correspondence in the heavy-rainfall regions characterising the Intertropical Convergence Zone-(ITCZ), the South Pacific Convergence Zone (SPCZ) and part of the western Pacific warm pool. An Empirical Orthogonal Function (EOF) analysis indicates two dominant modes of variation linking P and SSS changes, one mode at the seasonal timescale in both convergence zones, and the other at the ENSO timescale in the central-western equatorial Pacific (165 degrees E-160 degrees W) and in the SPCZ. The inferences derived from the EOF analysis are used in a simple linear regression model in order to try to specify P changes from known SSS changes. A comparison between hindcast and observed P changes suggests that, at seasonal and ENSO timescales, SSS changes could be used to infer the timing, but not the magnitude, of P in the central-western equatorial Pacific (165 degrees E-160 degrees W) and in the SPCZ mean area. The effects of evaporation, salt advection and mixed-layer depth on the results are discussed. Copyright (C) 1996 Elsevier Science Ltd. C1 METEO FRANCE,TOULOUSE,FRANCE. NOAA,WASHINGTON,DC. RP Delcroix, T (reprint author), ORSTOM,GRP SURTROPAC,NOUMEA,NEW CALEDONIA. RI Arkin, Phillip/F-5808-2010; Delcroix, Thierry/I-6103-2016 OI Delcroix, Thierry/0000-0002-8850-4865 NR 42 TC 82 Z9 84 U1 1 U2 14 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD, ENGLAND OX5 1GB SN 0967-0637 J9 DEEP-SEA RES PT I JI Deep-Sea Res. Part I-Oceanogr. Res. Pap. PD JUL PY 1996 VL 43 IS 7 BP 1123 EP 1141 DI 10.1016/0967-0637(96)00048-9 PG 19 WC Oceanography SC Oceanography GA VV033 UT WOS:A1996VV03300010 ER PT J AU Edgington, DN Robbins, JA Colman, SM Orlandini, KA Gustin, MP AF Edgington, DN Robbins, JA Colman, SM Orlandini, KA Gustin, MP TI Uranium-series disequilibrium, sedimentation, diatom frustules, and paleoclimate change in Lake Baikal SO EARTH AND PLANETARY SCIENCE LETTERS LA English DT Article DE Lake Baikal; paleoclimatology; diatoms; frustules; U-234/Th-230; fluviolacustrine sedimentation ID BIOGENIC SILICA; CORES AB The large volume of water, approximately one-fifth of the total surface fresh water on the planet, contained in Lake Baikal in southeastern Siberia is distinguished by having a relatively high concentration of uranium (ca. 2 nM), and, together with the surface sediments, an unusually high U-234/U-238 alpha activity ratio of 1.95. About 80% of the input of 234 uranium to the lake, with a U-234/U-238 ratio of 2.0, comes from the Selenga River, Profiles of uranium, as well as the extent of isotopic disequilibrium in a 9 m sediment core collected on Academic Ridge, generally show high values during interglacial periods corresponding to high diatom frustule numbers (DiFr) and biogenic silica (BSi) data that have been reported elsewhere. During glacial periods (low DiFr and BSi), uranium progeny (U-234 and Th-230) were in secular equilibrium with low concentrations of their parent U-238. Radionuclide distributions were interpreted in terms of a quantitative model allowing for adsorption of riverine inputs of uranium onto two classes of sedimenting particles with differing U-238/Th-232 ratios and uranium progeny in secular equilibrium. If the U-234/U-238 activity ratio of adsorbed uranium has remained constant, mean sedimentation rates can be independently estimated as 3.6 +/- 0.6 and 3.7 +/- 0.9 cm . kyr(-1) for the decay of U-234 and in-growth of Th-230, respectively. These rates are consistent with a mean rate of 3.76 cm . kyr(-1), calculated by optimization of the correspondence between adsorbed U-238 and delta(18)O in dated oceanic sediments, The adsorbed uranium apparently tracks variable river flow during interglacials and is drastically reduced during periods of glaciation. Evidently, uranium has not been significantly redistributed within Baikal sediments over at least the past 250 kyr and is a unique, biologically non-essential, tracer for climate-sensitive processes, which provide their own internal geochronometers, potentially useful for ages up to 1 Myr BP. C1 NOAA,GREAT LAKES ENVIRONM RES LAB,ANN ARBOR,MI 48105. US GEOL SURVEY,WOODS HOLE,MA 02543. ARGONNE NATL LAB,DIV ENVIRONM RES,ARGONNE,IL 60439. RP Edgington, DN (reprint author), UNIV WISCONSIN,CTR GREAT LAKES STUDIES,MILWAUKEE,WI 53204, USA. NR 29 TC 62 Z9 67 U1 0 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 JUL PY 1996 VL 142 IS 1-2 BP 29 EP 42 DI 10.1016/0012-821X(96)00085-4 PG 14 WC Geochemistry & Geophysics SC Geochemistry & Geophysics GA UZ230 UT WOS:A1996UZ23000004 ER PT J AU Baker, ET Chen, YJ Morgan, JP AF Baker, ET Chen, YJ Morgan, JP TI The relationship between near-axis hydrothermal cooling and the spreading rate of mid-ocean ridges SO EARTH AND PLANETARY SCIENCE LETTERS LA English DT Article DE mid-ocean ridges; sea-floor spreading; hydrothermal vents; heat flux ID EAST PACIFIC RISE; DE-FUCA-RIDGE; APPARENT MAGMATIC BUDGET; CURRENT PLATE MOTIONS; HOT-SPRINGS; VENT-FIELD; SEISMIC STRUCTURE; MIDOCEAN RIDGES; HEAT-FLOW; JUAN AB Recent seismic observations and new crustal thermal models suggest that near-axis (+/-1 km from the spreading axis) hydrothermal cooling increases linearly with increasing spreading rate. We present here the first corroborating evidence from near-axis hydrothermal plume observations. Comprehensive surveys of plume distributions have now been conducted on multi-segment portions of ridge crest with full-spreading rates from 20 to 150 km/Myr. These surveys find that p(h), the fraction of ridge crest length overlain by hydrothermal plumes, and full-spreading rate, u(s), are related by p(h) = alpha u(s), where alpha = 0.004 Myr/km. We recast this large-scale spatial variability into long-term temporal variability by postulating that any vent field site is hydrothermally active for an au, fraction of geologic time. We then use this relationship and the mean of eight studies that have determined instantaneous heat flux, H-a, at vent field scales, 75 +/- 45 MW/km, to estimate the time-averaged heat flux, (H-a) over bar as H-a alpha u(s). Applying these scaled values of (H-a) over bar to the distribution of mid-ocean ridge spreading rates yields a global near-axis heat flux, , of 8.8 x 10(11) W, This value is similar to 10% of the total oceanic hydrothermal heat flux, and agrees with a crustal cooling model-derived value of of 9 x 10(11) W. Our estimate of , implies a mean global He-3/heat ratio of 2.4-8.3 X 10(-13) cm(3)/J (STP), and a high-temperature hydrothermal fluid flow of 1.8 x 10(13) kg/yr. C1 OREGON STATE UNIV,COLL OCEANOG,CORVALLIS,OR 97331. UNIV CALIF SAN DIEGO,INST GEOPHYS & PLANETARY PHYS,LA JOLLA,CA 92093. 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; Chen, YanJing/B-1392-2013 OI Wright, Dawn/0000-0002-2997-7611; NR 56 TC 78 Z9 82 U1 3 U2 15 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0012-821X J9 EARTH PLANET SC LETT JI Earth Planet. Sci. Lett. PD JUL PY 1996 VL 142 IS 1-2 BP 137 EP 145 DI 10.1016/0012-821X(96)00097-0 PG 9 WC Geochemistry & Geophysics SC Geochemistry & Geophysics GA UZ230 UT WOS:A1996UZ23000011 ER PT J AU Cahill, TA Gill, TE Reid, JS Gearhart, EA Gillette, DA AF Cahill, TA Gill, TE Reid, JS Gearhart, EA Gillette, DA TI Saltating particles, playa crusts and dust aerosols at Owens (dry) Lake, California SO EARTH SURFACE PROCESSES AND LANDFORMS LA English DT Article; Proceedings Paper CT Workshop on the Response of Aeolian Processes to Global Climate Change CY MAR 24-29, 1994 CL DESERT STUDIES CTR, ZZYZX, CA HO DESERT STUDIES CTR DE playa; dust; PM(10); Owens (dry) Lake; crust; saltation; sand run ID VEGETATION; TRANSPORT; SAMPLER AB As part of the multinational Lake Owens Dust Experiment (LODE), we have studied the generation of dust storms on the south sand sheet of Owens (dry) Lake, California, an anthropogenically desiccated playa reported to be the single greatest source of particulate matter in North America. During March 1993, we performed an intensive field study including eight significant dust storms, building on our prior work (1978-1984) and preliminary studies (1991-1992). We studied sources and magnitude of coarse saltating particles, the meteorological conditions that allow them to become mobile across the flat playa of Owens (dry) Lake, and how the motion of saltating particles across different types of playa surfaces results in the generation of PM(10) dusts (aerosol particles smaller than 10 mu m aerodynamic diameter). Saltating grains of lacustrine sand and broken crust abrade and disaggregate the playa surface into fine aerosols, and the resulting PM(10) concentrations recorded during major dust storms are among the highest ever recorded in North America. On 23 March 1993, we measured a 2 h concentration on the playa of 40620 mu g m(-3), as far as we can determine the highest ambient PM(10) value ever recorded in the U.S.A. Abrasion of salt-silt-clay crusts by saltation is shown to be responsible for all but a small part of one dust storm. The quantity 'sand run', saltating particle transport multiplied by wind run, is shown to be very closely correlated with dust aerosol concentration. Finally, we have established that on-lake bed studies are essential for quantitative prediction of dust events on the Owens (dry) Lake bed, despite the difficult conditions encountered. C1 UNIV CALIF DAVIS,AIR QUAL GRP,CROCKER NUCL LAB,DAVIS,CA 95616. UNIV CALIF DAVIS,DEPT LAND AIR & WATER RESOURCES,DAVIS,CA 95616. NOAA,ATMOSPHER SCI MODELING DIV,AIR RESOURCES LAB,RES TRIANGLE PK,NC 27711. RI Reid, Jeffrey/B-7633-2014; OI Reid, Jeffrey/0000-0002-5147-7955; Gill, Thomas E/0000-0001-9011-4105 NR 33 TC 77 Z9 78 U1 3 U2 19 PU JOHN WILEY & SONS LTD PI W SUSSEX PA BAFFINS LANE CHICHESTER, W SUSSEX, ENGLAND PO19 1UD SN 0197-9337 J9 EARTH SURF PROCESSES JI Earth Surf. Process. Landf. PD JUL PY 1996 VL 21 IS 7 BP 621 EP 639 PG 19 WC Geography, Physical; Geosciences, Multidisciplinary SC Physical Geography; Geology GA UX591 UT WOS:A1996UX59100004 ER PT J AU Gillette, DA Herbert, G Stockton, PH Owen, PR AF Gillette, DA Herbert, G Stockton, PH Owen, PR TI Causes of the fetch effect in wind erosion SO EARTH SURFACE PROCESSES AND LANDFORMS LA English DT Article; Proceedings Paper CT Workshop on the Response of Aeolian Processes to Global Climate Change CY MAR 24-29, 1994 CL DESERT STUDIES CTR, ZZYZX, CA HO DESERT STUDIES CTR DE wind erosion; threshold velocity; fetch effect; mass transport ID FIELD; SURFACES AB The increase of soil mass flux with distance downwind, the fetch effect for wind erosion, has been observed and reported on since 1939. This model incorporates the following three mechanisms. (1) The 'avalanching' mechanism in which one particle moving downwind would dislodge one or more particles upon impact with the surface. The result of a chain of such events is an increase of mass flux with distance. (2) The 'aerodynamic feedback' effect, suggested by P. R. Owen, in which the aerodynamic roughness height is increased by saltation of particles; the resulting increased momentum flux increases saltation. These increases define a positive feedback loop with respect to distance downwind. (3) The 'soil resistance' mechanism, which is largely an expression of the change with distance of threshold velocity. Change of threshold velocities may be caused by inhomogeneities of the soil or progressive destruction of aggregates and crust in the direction of saltation fetch. An experiment was run in March 1993 at Owens Lake to test this model. Detailed measurements of wind profiles and mass fluxes were taken on a line parallel to the wind direction. These data support the proposed three-mechanism model. C1 NOAA,CLIMATE MONITORING & DIAGNOST LAB,BOULDER,CO 80303. SENSIT LABS INC,MAYVILLE,ND 58257. UNIV LONDON IMPERIAL COLL SCI TECHNOL & MED,LONDON,ENGLAND. RP Gillette, DA (reprint author), NOAA,AIR RESOURCES LAB,ATMOSPHER SCI MODELING DIV,MD-81,RES TRIANGLE PK,NC 27711, USA. NR 19 TC 96 Z9 104 U1 2 U2 11 PU JOHN WILEY & SONS LTD PI W SUSSEX PA BAFFINS LANE CHICHESTER, W SUSSEX, ENGLAND PO19 1UD SN 0197-9337 J9 EARTH SURF PROCESSES JI Earth Surf. Process. Landf. PD JUL PY 1996 VL 21 IS 7 BP 641 EP 659 DI 10.1002/(SICI)1096-9837(199607)21:7<641::AID-ESP662>3.0.CO;2-9 PG 19 WC Geography, Physical; Geosciences, Multidisciplinary SC Physical Geography; Geology GA UX591 UT WOS:A1996UX59100005 ER PT J AU Pratt, GC Orr, EJ Bock, DC Strassman, RL Fundine, DW Twaroski, CJ Thornton, JD Meyers, TP AF Pratt, GC Orr, EJ Bock, DC Strassman, RL Fundine, DW Twaroski, CJ Thornton, JD Meyers, TP TI Estimation of dry deposition of inorganics using filter pack data and inferred deposition velocity SO ENVIRONMENTAL SCIENCE & TECHNOLOGY LA English DT Article ID ATMOSPHERIC DEPOSITION; CANOPY INTERACTIONS; SULFUR-DIOXIDE; FOREST CANOPY; NITRIC-ACID; SO2; PARTICLES; GASES; MODEL AB Low-volume filter packs were used at several sites in Minnesota to measure weekly averaged concentrations of sulfur dioxide, nitric acid vapor, and selected inorganic components of the small particles (SO42-, NO3-, NH4+, Ca, Mg, Na, K, and Cl). Hourly dry deposition velocities (V-d) were inferred using a multiple-layer canopy resistance model developed by the NOAA Air Resources Laboratory. Annual mean deposition velocities in centimeters per second (cm/ s) for the years 1991-1993 ranged from 0.83 to 1.46 for HNO3, from 0.28 to 0.42 for SO2, and from 0.09 to 0.15 for small particles. Deposition velocities were distinctly cyclical, both annually and diurnally, with maximum values in the summertime and at midday for all species. Weekly averaged deposition velocities were multiplied with the low-volume filter pack measurements of air concentrations to obtain dry deposition fluxes. Dry deposition of all substances was generally highest in and near the Minneapolis - St. Paul metropolitan area and decreased with increasing distance from the metro area. Dry deposition of total sulfur and total nitrogen, respectively, ranged from 0.98 and 0.53 kg ha(-1) yr(-1) at a remote site to 9.24 and 2.36 kg ha(-1) yr(-1) in the metro area. Dry deposition of Ca, K, Mg, and Na constituted a small fraction, typically less than 10%, of total (wet + dry) deposition of these substances; however, the low-volume filter pack sampling method does not capture the largest of the coarse particles and may miss significant amounts of these elements. Dry deposition of sulfur and nitrogen, summed for all species containing these elements, averaged 22 and 14%, respectively, of the total (wet + dry) deposition of these elements. C1 NOAA, AIR RESOURCES LAB, ATMOSPHER TURBULENCE & DIFFUS DIV, OAK RIDGE, TN 37831 USA. RP Pratt, GC (reprint author), MINNESOTA POLLUT CONTROL AGCY, AIR QUAL DIV, 520 LAFAYETTE RD, ST PAUL, MN 55155 USA. RI Meyers, Tilden/C-6633-2016 NR 35 TC 26 Z9 26 U1 0 U2 1 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 0013-936X J9 ENVIRON SCI TECHNOL JI Environ. Sci. Technol. PD JUL PY 1996 VL 30 IS 7 BP 2168 EP 2177 DI 10.1021/es9505558 PG 10 WC Engineering, Environmental; Environmental Sciences SC Engineering; Environmental Sciences & Ecology GA UU548 UT WOS:A1996UU54800034 ER PT J AU Arkoosh, MR Clemons, E Huffman, P Sanborn, HR Casillas, E Stein, JE AF Arkoosh, MR Clemons, E Huffman, P Sanborn, HR Casillas, E Stein, JE TI Leukoproliferative response of splenocytes from English sole (Pleuronectes vetulus) exposed to chemical contaminants SO ENVIRONMENTAL TOXICOLOGY AND CHEMISTRY LA English DT Article DE immune dysfunction; biomarker; mitogen; leukoproliferative response; PAH ID POLYCYCLIC AROMATIC HYDROCARBON; PUGET-SOUND; PAROPHRYS-VETULUS; HEPATIC-LESIONS; LEIOSTOMUS-XANTHURUS; TOXIC-CHEMICALS; POLLUTED HARBOR; SEDIMENTS; FISH; LYMPHOCYTES AB The leukoproliferative (LP) response of splenic leukocytes from the marine benthic fish English sole (Pleuronectes vetulus) stimulated with the mitogens lipopolysaccharide (LPS), concanavalin A (Con A), and pokeweed mitogen (PWM) was examined as a biomarker of immunotoxic effects. English sole were exposed to contaminants, either by injection of an organic-solvent extract of a sediment containing polycyclic aromatic compounds (PACs) or placed for up to 5 weeks on a reference sediment containing 0.15 to 1.5% (v/v) of the PAC-contaminated sediment. English sole either injected with the contaminated extract or held on PAC-contaminated sediment had an augmented response to Con A. The LP response to LPS showed no relationship to PAC exposure in laboratory-exposed exposed fish, while PWM showed no consistent relationship to exposure to PACs. In a field study, English sole captured from an urban area in Puget Sound, Washington, USA, contaminated with PACs and other chemical contaminants had a significantly augmented LP response to Con A and PWM in comparison to the LP response in fish from a nonurban reference site. Fish from another nonurban site also had an augmented LP response to Con A, indicating that the elevation of the Con A LP response can also result from factors other than chemical contaminant exposure. In addition, English sole from this site also had an augmented LP response to LPS, whereas fish from urban sites did not exhibit an augmented LP response to LPS. Overall, the results demonstrated that although the LP response in splenic leukocytes of English sole to Con A was linked to contaminant exposure, the LP response to Con A did not exhibit high specificity as an indicator of chemical contaminant exposure. However, the concerted use of Con A, LPS, and PWM allowed fdr identification of apparent chemical contaminant-induced alterations of the LP response in English sole from an urban area of Puget Sound. RP Arkoosh, MR (reprint author), NOAA,HATFIELD MARINE SCI CTR,ENVIRONM CONSERVAT DIV,2030 MARINE SCI DR,NEWPORT,OR 97365, USA. NR 44 TC 13 Z9 14 U1 0 U2 0 PU SETAC PRESS PI PENSACOLA PA 1010 NORTH 12TH AVE, PENSACOLA, FL 32501-3370 SN 0730-7268 J9 ENVIRON TOXICOL CHEM JI Environ. Toxicol. Chem. PD JUL PY 1996 VL 15 IS 7 BP 1154 EP 1162 DI 10.1897/1551-5028(1996)015<1154:LROSFE>2.3.CO;2 PG 9 WC Environmental Sciences; Toxicology SC Environmental Sciences & Ecology; Toxicology GA VF370 UT WOS:A1996VF37000020 ER PT J AU Carr, RS Long, ER Windom, HL Chapman, DC Thursby, G Sloane, GM Wolfe, DA AF Carr, RS Long, ER Windom, HL Chapman, DC Thursby, G Sloane, GM Wolfe, DA TI Sediment quality assessment studies of Tampa Bay, Florida SO ENVIRONMENTAL TOXICOLOGY AND CHEMISTRY LA English DT Article DE pore water; sediment toxicity testing; sea urchin fertilization; amphipod; Microtox(R) ID TOXICITY; MARINE AB A survey of the toxicity of sediments throughout the Tampa Bay estuary was performed as part of the National Oceanic and Atmospheric Administration's National Status and Trends Program. The objectives of the survey were to determine the spatial extent and severity of toxicity and to identify relationships between chemical contamination and toxicity. Three independent toxicity tests were performed: a 10-d amphipod survival test of the whole sediments with Ampelisca abdita, a sea urchin fertilization test df sediment pore water with Arbacia punctulata, and a 5-min Microtox(R) bioluminescence test with solvent extracts of the sediments. Seventy-three percent of the 165 undiluted sediment pore-water samples were significantly toxic relative to reference samples with the sea urchin fertilization test. In contrast, only 2% of the 165 samples were significantly toxic in the amphipod tests. The causes of toxicity were not determined. However, concentrations of numerous trace metals, pesticides, poly-chlorinated biphenyl (PCB) congeners, polycyclic aromatic hydrocarbons (PAHs), and ammonia were highly correlated with pore-water toxicity. Concentrations of many substances, especially total dichlorodiphenyltrichloroethanes (DDTs), endrin, total PCBs, certain PAHs, lead, and zinc, occurred at concentrations in the toxic samples that equaled or exceeded concentrations that have been previously associated with sediment toxicity. C1 NOAA,ORCA,COASTAL MONITORING & BIOEFFECTS ASSESSEMENT DIV,SEATTLE,WA 98112. SKIDAWAY INST OCEANOG,SAVANNAH,GA 31411. SCI APPLICAT INT CORP,NARRAGANSETT,RI 02882. FLORIDA DEPT ENVIRONM PROTECT,TALLAHASSEE,FL 32399. NOAA,ORCA,COASTAL MONITORING & BIOEFFECTS ASSESSMENT DIV,SILVER SPRING,MD 20910. RP Carr, RS (reprint author), TEXAS A&M UNIV,TEXAS GULF COAST FIELD STN,NATL BIOL SERV,BOX 315,6300 OCEAN DR,CORPUS CHRISTI,TX 78412, USA. NR 38 TC 112 Z9 118 U1 1 U2 11 PU SETAC PRESS PI PENSACOLA PA 1010 NORTH 12TH AVE, PENSACOLA, FL 32501-3370 SN 0730-7268 J9 ENVIRON TOXICOL CHEM JI Environ. Toxicol. Chem. PD JUL PY 1996 VL 15 IS 7 BP 1218 EP 1231 DI 10.1897/1551-5028(1996)015<1218:SQASOT>2.3.CO;2 PG 14 WC Environmental Sciences; Toxicology SC Environmental Sciences & Ecology; Toxicology GA VF370 UT WOS:A1996VF37000030 ER PT J AU Balthis, WL Voit, EO Meaburn, GM AF Balthis, WL Voit, EO Meaburn, GM TI Setting prediction limits for mercury concentrations in fish having high bioaccumulation potential SO ENVIRONMETRICS LA English DT Article DE mercury; fish; S-distribution; log-normal distribution ID S-DISTRIBUTION; APPROXIMATION AB The potential health risks associated with the consumption of contaminated fish have long been recognized by public health officials as cause for concern, and in the USA many states have developed strategies for issuing fish consumption advisories. The methods and criteria for establishing such advisories vary widely among the states, however, and the advice given to anglers may not be consistent between neighbouring states, even regarding the same body of water. Fish contaminant monitoring data are often used as the basis for adivsories, but few methods are available for the quantification and distributional characterization of contaminant levels in fish, Log-normality of pollutant concentrations (i.e. normality of the logarithm of pollutant concentrations) is a common assumption, yet statistical tests of normality do not always confirm this assumption. An alternative to the log-normal distribution is the S-distribution, which has been shown to approximate many statistical distributions with high accuracy, and often results in improved fit over the log-normal. In this paper we evaluate the performance of the S-distribution in characterizing contaminant concentrations, and compare the results to those obtained using the log-normal distribution, A method based on trends in mercury distribution parameters across length classes is presented and used to obtain 95 per-cent prediction limits for mercury concentrations in king mackerel (Scomberomorus cavalla). It is shown that this method gives narrower prediction limits compared to those obtained using standard regression techniques. C1 NATL MARINE FISHERIES SERV,SE FISHERIES SCI CTR,CHARLESTON LAB,CHARLESTON,SC 29422. RP Balthis, WL (reprint author), MED UNIV S CAROLINA,DEPT BIOMETRY & EPIDEMIOL,171 ASHLEY AVE,CHARLESTON,SC 29425, USA. NR 27 TC 17 Z9 17 U1 0 U2 2 PU JOHN WILEY & SONS LTD PI W SUSSEX PA BAFFINS LANE CHICHESTER, W SUSSEX, ENGLAND PO19 1UD SN 1180-4009 J9 ENVIRONMETRICS JI Environmetrics PD JUL-AUG PY 1996 VL 7 IS 4 BP 429 EP 439 DI 10.1002/(SICI)1099-095X(199607)7:4<429::AID-ENV225>3.0.CO;2-C PG 11 WC Environmental Sciences; Mathematics, Interdisciplinary Applications; Statistics & Probability SC Environmental Sciences & Ecology; Mathematics GA VB649 UT WOS:A1996VB64900007 ER PT J AU Cooper, LY AF Cooper, LY TI Calculating combined buoyancy- and pressure-driven flow through a shallow, horizontal, circular vent: Application to a problem of steady burning in a ceiling-vented enclosure SO FIRE SAFETY JOURNAL LA English DT Article AB A model was developed previously for calculating combined buoyancy- and pressure-driven (i.e. forced) flow through a shallow, circular, horizontal vent where the vent-connected spaces are filled with fluids of different density in an unstable configuration (density of the top fluid is larger than that of the bottom). In this paper the model is summarized and then applied to the problem of steady burning in a ceiling-vented enclosure where normal atmospheric conditions characterize the upper-space environment. Such fire scenarios are seen to involve a zero to relatively moderate cross-vent pressure difference and bidirectional exchange flow between the enclosure and the upper space. A solution to the problem leads to a general result that relates the rate of energy release of the fire to the area of the vent and the temperature and oxygen concentration of the upper portion of the enclosure environment. This result is seen to be consistent with previously published data from experiments involving ceiling-vented fire scenarios. RP Cooper, LY (reprint author), NIST,BLDG & FIRE RES LAB,GAITHERSBURG,MD 20899, USA. NR 12 TC 11 Z9 14 U1 1 U2 2 PU ELSEVIER SCI LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD, OXON, ENGLAND OX5 1GB SN 0379-7112 J9 FIRE SAFETY J JI Fire Saf. J. PD JUL PY 1996 VL 27 IS 1 BP 23 EP 35 DI 10.1016/S0379-7112(96)00041-0 PG 13 WC Engineering, Civil; Materials Science, Multidisciplinary SC Engineering; Materials Science GA WE159 UT WOS:A1996WE15900002 ER PT J AU Bolz, GR Burns, BR AF Bolz, GR Burns, BR TI Age and growth of larval Atlantic herring, Clupea harengus: A comparative study SO FISHERY BULLETIN LA English DT Article ID GEORGES BANK; OTOLITH MICROSTRUCTURE; NORTHERN ANCHOVY; ENGRAULIS-MORDAX; INCREMENTS; MORTALITY; FISHES; RATES; MAINE; AREA AB Age and growth of 1,746 Atlantic herring, Clupea harengus, larvae collected in the Nantucket Shoals-Georges Bank region during the autumn-winter seasons of 1976-77, 1988-89, 1989-90, 1990-91, 1991-92, 1992-93, and 1993-94 were determined by enumerating the daily growth increments of their sagittal otoliths. Growth with respect to length for each of the years was best described by a Gompertz curve. Owing to severe weather events in November, January, and February of the 1976-77 season which disrupted the fishes' feeding regimen, growth was much slower (0.16 mm/d) than in more recent years. Lower daily food consumption was reflected in the rapid and continual decrease in otolith diameter during the autumn and winter of 1976. Growth for the other six years was strong, showed only minor interseasonal fluctuations (0.22-0.24 mm/d), and ranged intraseasonally from a high of just over 0.40 mm/d in October to a low of 0.04 mm/d in February. A general model of larval herring growth was constructed with data from six recent field seasons. Inverse regressive methods were employed to generate a composite growth curve with confidence Limits for predicting age (days) for a given standard length (mm) from hatching until the onset of metamorphosis. Analysis of otolith growth revealed a dramatic increase in the growth rate of the lapillus at about 2.5 months (29.0 mm). It is suggested that this increase may coincide with, or immediately follow, the filling of the otic bullae with gas and may provide an easily obtainable marker for estimating the timing of this critical event. The importance of this phase in the life of larval herring is discussed, particularly with reference to the 1976-77 season. C1 NOAA,NATL MARINE FISHERIES SERV,NE FISHERIES SCI CTR,NARRAGANSETT LAB,NARRAGANSETT,RI 02882. RP Bolz, GR (reprint author), NOAA,NATL MARINE FISHERIES SERV,NE FISHERIES SCI CTR,WOODS HOLE LAB,WOODS HOLE,MA 02543, USA. NR 35 TC 14 Z9 14 U1 0 U2 6 PU NATL MARINE FISHERIES SERVICE SCIENTIFIC PUBL OFFICE PI SEATTLE PA 7600 SAND POINT WAY NE BIN C15700, SEATTLE, WA 98115 SN 0090-0656 J9 FISH B-NOAA JI Fish. Bull. PD JUL PY 1996 VL 94 IS 3 BP 387 EP 397 PG 11 WC Fisheries SC Fisheries GA UU710 UT WOS:A1996UU71000001 ER PT J AU Collette, BB Aadland, CR AF Collette, BB Aadland, CR TI Revision of the frigate tunas (Scombridae, Auxis), with descriptions of two new subspecies from the eastern Pacific SO FISHERY BULLETIN LA English DT Article AB Two cosmopolitan species of frigate tunas, Auxis thazard (Lacepede) and A. rochei (Risso), are differentiated primarily by the width of the corselet under the origin of the second dorsal fin and by the anterior extent of the dorsal scaleless area above the pectoral fin. Auxis thazard has five or fewer scales in the corselet under the second dorsal fin, and the dorsal scaleless area extends anterior to the tip of the pectoral fin; A. rochei has six or more scales and the dorsal scaleless area does not reach the tip of the pectoral fin. Of nine morphometric characters examined with ANCOVA, four body depth measurements were significantly different between the species. Auxis rochei is a slender species with each of the four body depth measurements approximately equal, whereas A. thazard is more tuna-shaped, with a deeper, more robust body and with more unequal body depth measurements. For both species, eastern Pacific populations differ from Atlantic and Indo-West Pacific populations at what we consider the subspecific level. The eastern Pacific A. thazard brachydorax new subspecies has more gill rakers, usually 43-48 vs. usually 38-42 in A. t. thazard. Body depth at anal-fin origin, pectoral-fin length, and corselet width were also significantly different between A. thazard brachydorax and A. t. thazard. The eastern Pacific A. rochei eudorax new subspecies has an even wider corselet than that of A. rochei rochei, usually more than 20 scales wide compared with 6-19 scales. RP Collette, BB (reprint author), NATL MUSEUM NAT HIST,NATL MARINE FISHERIES SERV,SYSTEMAT LAB,WASHINGTON,DC 20560, USA. NR 71 TC 24 Z9 30 U1 1 U2 1 PU NATL MARINE FISHERIES SERVICE SCIENTIFIC PUBL OFFICE PI SEATTLE PA 7600 SAND POINT WAY NE BIN C15700, SEATTLE, WA 98115 SN 0090-0656 J9 FISH B-NOAA JI Fish. Bull. PD JUL PY 1996 VL 94 IS 3 BP 423 EP 441 PG 19 WC Fisheries SC Fisheries GA UU710 UT WOS:A1996UU71000004 ER PT J AU Orsi, JA Jaenicke, HW AF Orsi, JA Jaenicke, HW TI Marine distribution and origin of prerecruit chinook salmon, Oncorhynchus tshawytscha, in southeastern Alaska SO FISHERY BULLETIN LA English DT Article ID OREGON AB Chinook salmon, Oncorhynchus tshawytscha, <71 cm total length, are typically not retained in directed marine fisheries of southeastern Alaska because of size restrictions; consequently, little is known of the origin or temporal and spatial distribution of these prerecruits. To obtain such data, commercial power trollers were chartered to fish for small chinook salmon with small hooks and lures within the Alexander Archipelago (inside waters) and the adjacent, coastal region (outside waters). During the 135-d study in February, May, and September 1986-87, a total of 5,838 prerecruit chinook salmon were caught, of which 539 contained coded-wire tags with information on stock origin. Age -.O chinook. salmon were caught in September during their first year at sea; they originated predominately from stream-type stocks of southeastern Alaska. Age -.1 chinook salmon in February and May were primarily from stream-type stocks of southeastern Alaska; however, by September most were from ocean-type stocks from British Columbia, Washington, and Oregon streams. Most age -.2 chinook salmon were from ocean-type stocks of southern origin. Average net marine migration rates of different chinook salmon age groups ranged from 0.1 to 6.9 km/d; the highest rates were for age 1.0 fish from Washington and Oregon. For coded-wire-tagged chinook salmon of the same ocean age group, growth rates of ocean-type fish were significantly (P<0.05) higher than growth rates of stream-type fish during most periods. Spatial distribution also differed by race: stream-type fish predominated in inside waters and ocean-type fish in outside waters. This study identifies the importance of marine waters of southeastern Alaska as a nursery area for an amalgam of prerecruit chinook salmon stocks originating between Oregon and southeastern Alaska, a range of 1,800 km. RP Orsi, JA (reprint author), NOAA,NATL MARINE FISHERIES SERV,ALASKA FISHERIES SCI CTR,AUKE BAY LAB,11305 GLACIER HIGHWAY,JUNEAU,AK 99801, USA. NR 41 TC 15 Z9 17 U1 0 U2 5 PU NATL MARINE FISHERIES SERVICE SCIENTIFIC PUBL OFFICE PI SEATTLE PA 7600 SAND POINT WAY NE BIN C15700, SEATTLE, WA 98115 SN 0090-0656 J9 FISH B-NOAA JI Fish. Bull. PD JUL PY 1996 VL 94 IS 3 BP 482 EP 497 PG 16 WC Fisheries SC Fisheries GA UU710 UT WOS:A1996UU71000008 ER PT J AU Pennington, M AF Pennington, M TI Estimating the mean and variance from highly skewed marine data SO FISHERY BULLETIN LA English DT Article ID LOGNORMAL-BASED ESTIMATORS; TRAWL SURVEY DATA; ABUNDANCE; FISH; MODELS; ROBUSTNESS; INDEXES AB The spatial distribution of marine organisms is highly patchy. Because of this patchy distribution, data from marine abundance surveys are highly skewed and have a large variance. Compounding the problem of estimating the mean abundance from such data, is that occasionally a relatively huge catch will occur. These large catches are not ''outliers'' but do dominate the estimates of the mean and variance. A lognormal model of the nonzero survey values (a Delta-distribution) is used to model survey data. The estimators, based on the lognormal model, appear to be much more efficient for marine data than the usual sample estimators. In particular, the lognormal-based estimators provide reasonable estimates for data sets that contain a very large catch. The properties and efficiency of the Delta-distribution estimators are examined and the techniques are applied to various marine data sets. RP Pennington, M (reprint author), NOAA,NATL MARINE FISHERIES SERV,WOODS HOLE LAB,WOODS HOLE,MA 02543, USA. NR 32 TC 73 Z9 83 U1 0 U2 6 PU NATL MARINE FISHERIES SERVICE SCIENTIFIC PUBL OFFICE PI SEATTLE PA 7600 SAND POINT WAY NE BIN C15700, SEATTLE, WA 98115 SN 0090-0656 J9 FISH B-NOAA JI Fish. Bull. PD JUL PY 1996 VL 94 IS 3 BP 498 EP 505 PG 8 WC Fisheries SC Fisheries GA UU710 UT WOS:A1996UU71000009 ER PT J AU Quinn, TP Nielsen, JL Gan, C Unwin, MJ Wilmot, R Guthrie, C Utter, FM AF Quinn, TP Nielsen, JL Gan, C Unwin, MJ Wilmot, R Guthrie, C Utter, FM TI Origin and genetic structure of chinook salmon, Oncorhynchus tshawytscha, transplanted from California to New Zealand: Allozyme and mtDNA evidence SO FISHERY BULLETIN LA English DT Article ID RAINBOW-TROUT; ATLANTIC SALMON; POPULATIONS; PATTERNS; PACIFIC; MANAGEMENT; MIGRATION; EVOLUTION; DISTANCE; STOCKS AB Chinook salmon, Oncorhynchus tshawytscha, transplanted from the Sacramento River, California, to the Waitaki River catchment of New Zealand at the turn of the century rapidly colonized many South Island rivers. Allozyme genotype and mtDNA haplotype frequencies were obtained from tissue samples from chinook salmon in Waitaki, Rakaia, Waimakariri, and Clutha rivers in New Zealand and compared with data from populations in the Sacramento River to provide further information on the origin of the NZ populations and to ascertain the genetic changes that have taken place since the transplant. Neither allozyme nor mtDNA unequivocally identified an ancestral ''seasonal'' run (fall, winter, or spring) for the NZ chinook salmon. Sacramento River samples collectively diverged from the NZ samples at allozyme loci, and mtDNA indicated greater similarity between NZ samples and fall-run rather than winter and spring runs from the Sacramento River. Significant variation was detected by mtDNA analysis between only two of the four populations within NZ, one of which has been landlocked by an impassable dam since 1956. The allozyme data identified significant variation within NZ, although less than has been documented among Sacramento River populations. The NZ populations also showed less genetic diversity (mean number of alleles per locus, proportion of loci that were polymorphic, and mean heterozygosity) than the Sacramento River populations. These lower values are consistent with a population bottleneck in the first generations after transplantation into the Waitaki River catchment and with founder effects during the formation of populations in the other NZ rivers. The combination of genetic differences and phenotypic variation among the NZ populations indicates that Pacific salmon populations can develop rapidly after colonizing suitable habitat. C1 US FOREST SERV,USDA,PACIFIC SW RES STN,ALBANY,CA 94710. STANFORD UNIV,HOPKINS MARINE STN,PACIFIC GROVE,CA 93950. NATL INST WATER & ATMOSPHERE,CHRISTCHURCH,NEW ZEALAND. NATL MARINE FISHERIES SERV,AUKE BAY LAB,JUNEAU,AK 99801. RP Quinn, TP (reprint author), UNIV WASHINGTON,SCH FISHERIES,POB 357980,SEATTLE,WA 98195, USA. NR 60 TC 49 Z9 49 U1 1 U2 7 PU NATL MARINE FISHERIES SERVICE SCIENTIFIC PUBL OFFICE PI SEATTLE PA 7600 SAND POINT WAY NE BIN C15700, SEATTLE, WA 98115 SN 0090-0656 J9 FISH B-NOAA JI Fish. Bull. PD JUL PY 1996 VL 94 IS 3 BP 506 EP 521 PG 16 WC Fisheries SC Fisheries GA UU710 UT WOS:A1996UU71000010 ER PT J AU Sanchez, G Perry, HM Trigg, CB Vecchione, M Roper, C Biesiot, PM AF Sanchez, G Perry, HM Trigg, CB Vecchione, M Roper, C Biesiot, PM TI Morphometry of juvenile and subadult Loligo pealei and L-plei from the northern Gulf of Mexico SO FISHERY BULLETIN LA English DT Article ID SQUID AB Two species of Loligo are abundant in northern Gulf waters: the long-finned squid, Loligo pealei, and the arrow squid, Loligo plei. Variability within species and similarities between the species often hamper accurate identification. The two species more closely resemble each other in areas of sympatry, and there is overlap in almost all of the diagnostic characters. Small specimens of Loligo are not easily identified, and there are few studies detailing their morphometry. Because of the taxonomic uncertainties associated with the identification of juveniles and subadults of L. pealei and L. plei, the species were differentiated by isoelectric focusing, and morphometric characters and indices of potential use in species separation were evaluated. Emphasis was placed on those taxonomic characters suitable for use in the field. Best discrimination between the two species was achieved with combinations of measurements of characters and calculated indices associated with cartilaginous structures (funnel cartilage length, gladius width [GW], nuchal cartilage length, and rachis width [RW]) and the shape of the gladius. An arbitrary cutoff in GW/RW ratio of 2.7 (ratio of the greatest width of the gladius to the width of the free rachis at the junction of the vane) correctly classified 100% of the L. plei and 91% of the L. pealei. The overall shape of the gladius (broader and more rounded in L. pealei), presence or absence of marginal ribs in the vane of the gladius, and the nature of the junction of the vane and free rachis (junction gradual and not distinct in L. pealei) were also useful in distinguishing the two species. C1 SMITHSONIAN INST,NATL MUSEUM NAT HIST,NOAA,NMFS SYSTEMAT LAB,WASHINGTON,DC 20560. SMITHSONIAN INST,NATL MUSEUM NAT HIST,DEPT INVERTEBRATE ZOOL,WASHINGTON,DC 20560. UNIV SO MISSISSIPPI,DEPT BIOL SCI,HATTIESBURG,MS 39406. RP Sanchez, G (reprint author), GULF COAST RES LAB,POB 7000,OCEAN SPRINGS,MS 39566, USA. NR 12 TC 6 Z9 6 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 JUL PY 1996 VL 94 IS 3 BP 535 EP 550 PG 16 WC Fisheries SC Fisheries GA UU710 UT WOS:A1996UU71000012 ER PT J AU VanDoornik, DM Milner, GB Winans, GA AF VanDoornik, DM Milner, GB Winans, GA TI Transferrin polymorphism in coho salmon, Oncorhynchus kisutch, and application to genetic stock identification SO FISHERY BULLETIN LA English DT Article ID PACIFIC SALMON; BRITISH-COLUMBIA; ALLELE FREQUENCY; TEMPORAL CHANGES; POPULATIONS; CALIFORNIA AB The blood protein transferrin is an important source for identifying genetic variation in coho salmon, Oncorhynchus kisutch, with starch gel electrophoresis. We present new data for transferrin allele frequencies for 48 samples of coho salmon collected at 34 different locations from Oregon to southern British Columbia. To analyze transferrin allele frequencies from a larger geographic area, data from various sources were compiled for 135 samples from sites from California to southern British Columbia. In a statistical analysis of temporal variation within locations, 26 of 65 pairwise comparisons (41%) showed significant differences between samples (P<0.05). An analysis of variance revealed significant between-locale variability and no significant within-locale variability due to whether or not, the brood gears of the samples were three years apart. Relative gene diversity values were 22.3% between geographic regions, 2.1% between stocks within geographic regions, 3.1% between temporal comparisons, and 72.5% for within-sample variation. Total genetic diversity (H-T) was 0.5867 and the average genetic diversity within populations (H-s) equaled 0.425. The samples showed genetic variation that was related to geographic location. Applications of transferrin data to genetic stock identification are discussed in relation to these results. C1 NOAA,NATL MARINE FISHERIES SERV,NW FISHERIES SCI CTR,SEATTLE,WA 98112. RP VanDoornik, DM (reprint author), NOAA,NATL MARINE FISHERIES SERV,NW FISHERIES SCI CTR,MANCHESTER FIELD STN,POB 130,MANCHESTER,WA 98353, USA. NR 31 TC 5 Z9 5 U1 0 U2 0 PU NATL MARINE FISHERIES SERVICE SCIENTIFIC PUBL OFFICE PI SEATTLE PA 7600 SAND POINT WAY NE BIN C15700, SEATTLE, WA 98115 SN 0090-0656 J9 FISH B-NOAA JI Fish. Bull. PD JUL PY 1996 VL 94 IS 3 BP 566 EP 575 PG 10 WC Fisheries SC Fisheries GA UU710 UT WOS:A1996UU71000014 ER PT J AU Feely, RA Baker, ET Marumo, K Urabe, T Ishibashi, J Gendron, J Lebon, GT Okamura, K AF Feely, RA Baker, ET Marumo, K Urabe, T Ishibashi, J Gendron, J Lebon, GT Okamura, K TI Hydrothermal plume particles and dissolved phosphate over the superfast-spreading southern East Pacific Rise SO GEOCHIMICA ET COSMOCHIMICA ACTA LA English DT Article ID MID-ATLANTIC RIDGE; NORTHWEST NAZCA PLATE; DE-FUCA RIDGE; METALLIFEROUS SEDIMENTS; PHOSPHORUS; WATER; DISTRIBUTIONS; 21-DEGREES-N; 26-DEGREES-N; GENESIS AB The distribution and elemental composition of hydrothermal plume particles were mapped along the superfast spreading southern East Pacific Rise from the Garret Transform Fault to similar to 19 degrees S. Hydrographic and optical data were obtained using a series of seven tow-yes and thirty vertical casts employing a rosette sampler with 19-L, PVC bottles for collecting discrete samples of various dissolved and particulate hydrothermal species. The extent of hydrothermal plume coverage over the southern East Pacific Rise between 13 degrees 33' and 18 degrees 40'S is significantly greater than in other ridgecrest systems. The region south of 17 degrees 20'S is characterized by significant enrichments of volatile gases resulting from magmatic input of fresh lava at the seafloor. Between 17 degrees 20' and 18 degrees 40'S, the ratio of S/Fe in the plume particles is highly correlated with the dissolved gases in the neutrally-buoyant hydrothermal plumes. Plume inventories of Fe and S over this portion of the southern East Pacific Rise are 6-150 times higher than what has been observed over other vent fields because the total abundance of plumes is much greater. In addition, significant depletions (>100 nmol/L) of dissolved phosphate over the ridge axis were observed at the depth of the hydrothermal plumes. These results provide clear evidence that this section of the southern East Pacific Rise maintains the most extensive complex of hydrothermal plumes observed thus far on the global ridgecrest system. C1 GEOL SURVEY JAPAN,TSUKUBA,IBARAKI 305,JAPAN. UNIV TOKYO,FAC SCI,EARTHQUAKE CHEM LAB,BUNKYO KU,TOKYO 113,JAPAN. KYOTO UNIV,FAC SCI,INSTRUMENTAL ANAL RES CTR,SAKYO KU,KYOTO 60601,JAPAN. RP Feely, RA (reprint author), NOAA,PACIFIC MARINE ENVIRONM LAB,7600 SAND POINT WAY NE,SEATTLE,WA 98115, USA. RI OKAMURA, Kei/C-7817-2011 OI OKAMURA, Kei/0000-0002-7796-4284 NR 61 TC 58 Z9 59 U1 1 U2 11 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD, ENGLAND OX5 1GB SN 0016-7037 J9 GEOCHIM COSMOCHIM AC JI Geochim. Cosmochim. Acta PD JUL PY 1996 VL 60 IS 13 BP 2297 EP 2323 DI 10.1016/0016-7037(96)00099-3 PG 27 WC Geochemistry & Geophysics SC Geochemistry & Geophysics GA UV614 UT WOS:A1996UV61400003 ER PT J AU Wu, CC Dryer, M AF Wu, CC Dryer, M TI Predicting the initial IMF B-z polarity's change at 1 AU caused by shocks that precede coronal mass ejections SO GEOPHYSICAL RESEARCH LETTERS LA English DT Article ID INTERPLANETARY MAGNETIC-FIELD; STORMS AB There are important geomagnetic implications whenever the interplanetary magnetic field (IMF) turns northward or southward. This paper addresses only the initial turning when the solar events' shock signals first reach 1 AU. A three-dimensional (3D), time-dependent, MHD model [Han et al., 1988] of disturbances' propagation through the solar wind and interplanetary magnetic field (IMF) has been used by Wu (1993) to develop a ''recipe'' for the initial north- or south-turning of the IMF's polarity. Its temporal behavior thereafter is not addressed in this paper. Four independent data sets have been used [Wu et al., 1996a, b, c] in a study currently underway to test this idea. A fifth data set [Gosling et al., 1990] is used in this paper to examine, via this idea, the initial B-z polarity's change at 1 AU caused by shocks associated with interplanetary/coronal mass ejection events and large geomagnetic storms during the period of August 1978 to October 1982. Twenty-five events from this fifth data set are studied; the prediction model is in agreement with twenty-one of them. Our results suggest that the initial IMF B-z polarity's change at 1 AU may be associated with a simple relationship between the location of the solar disturbance, the relative position of the heliospheric current sheet, and the initial toward or away; polarity of the IMF at Earth. C1 NOAA, SPACE ENVIRONM CTR, RESE, BOULDER, CO 80303 USA. UNIV COLORADO, COOPERAT INST RES ENVIRONM SCI, BOULDER, CO 80309 USA. RP Wu, CC (reprint author), NATL CENT UNIV, INST SPACE SCI, CHUNGLI 32054, TAIWAN. 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 0094-8276 J9 GEOPHYS RES LETT JI Geophys. Res. Lett. PD JUL 1 PY 1996 VL 23 IS 14 BP 1709 EP 1712 DI 10.1029/96GL01721 PG 4 WC Geosciences, Multidisciplinary SC Geology GA UV847 UT WOS:A1996UV84700002 ER PT J AU Villalta, PW Lovejoy, ER Hanson, DR AF Villalta, PW Lovejoy, ER Hanson, DR TI Reaction probability of peroxyacetyl radical on aqueous surfaces SO GEOPHYSICAL RESEARCH LETTERS LA English DT Article ID ATMOSPHERIC CHEMISTRY; PHOTOCHEMISTRY; OZONE; HO2 AB The uptake coefficient for the loss of peroxyacetyl radical, CH3C(O)O-2 (PA), on H2O is measured to be 0.0043 (+0.0024/-0.0015) at 274 +/- 3 K. Uptake measurements onto aqueous solutions of sodium ascorbate yield limits for the PA Henry's law coefficient in H2O (less than or equal to 0.1 M atm(-1)) and the CH3C(O)O-2 hydrolysis rate coefficient (greater than or equal to 7 x 10(5) M(-1) s(-1)) at similar to 275 K. These measurements support the hypothesis that PA heterogeneous reaction can mediate the loss of PAN in fog (Roberts et al., submitted manuscript, J. Geophys. Res., 1995). The most likely products of PA hydrolysis are HO2 and acetic acid. PA hydrolysis may be a significant sourer of odd hydrogen at night as well as an important source of acetic acid in the atmosphere. C1 NOAA,AERON LAB,ENVIRONM RES LABS,BOULDER,CO 80303. UNIV COLORADO,COOPERAT INST RES ENVIRONM SCI,BOULDER,CO 80309. OI Villalta, Peter/0000-0002-0067-3083 NR 29 TC 16 Z9 16 U1 0 U2 6 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 SN 0094-8276 J9 GEOPHYS RES LETT JI Geophys. Res. Lett. PD JUL 1 PY 1996 VL 23 IS 14 BP 1765 EP 1768 DI 10.1029/96GL01286 PG 4 WC Geosciences, Multidisciplinary SC Geology GA UV847 UT WOS:A1996UV84700016 ER PT J AU Vinnikov, KY Robock, A Stouffer, RJ Manabe, S AF Vinnikov, KY Robock, A Stouffer, RJ Manabe, S TI Vertical patterns of free and forced climate variations SO GEOPHYSICAL RESEARCH LETTERS LA English DT Article AB Observations of the vertical structure of atmospheric temperature changes over the past three decades show that while the global-average lower atmosphere has warmed, the upper troposphere and lower stratosphere have cooled. While these changes may be due to observed anthropogenic increases of greenhouse,eases, decreases of lower stratospheric ozone, and increases of tropospheric aerosols, the changes may also have been caused by natural unforced internal fluctuations of the climate system. Here we use the results of a 1000-year simulation from a mathematical model of the coupled ocean-atmosphere-land system performed without any changes in external forcing, so that we may consider its variations as a surrogate for free, internally-generated, natural fluctuations of the climate system. When the global mean surface air temperature is warm in the model, the lower troposphere, upper troposphere and lower stratosphere are also warm over most of the Earth, in contrast to the observations of the last three decades and to model simulations of the forced climate response due to increased greenhouse gases. The observed temperature change of the past three decades is therefore unlikely to have been caused solely by natural internal variations of the climate system, thereby strengthening the argument that these changes can at least partly be attributed to anthropogenic activities. C1 UNIV MARYLAND,DEPT METEOROL,COLLEGE PK,MD 20742. RP Vinnikov, KY (reprint author), PRINCETON UNIV,NOAA,GEOPHYS FLUID DYNAM LAB,PRINCETON,NJ 08542, USA. RI Vinnikov, Konstantin/F-9348-2010; Robock, Alan/B-6385-2016; OI Robock, Alan/0000-0002-6319-5656 NR 20 TC 16 Z9 16 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 JUL 1 PY 1996 VL 23 IS 14 BP 1801 EP 1804 DI 10.1029/96GL01736 PG 4 WC Geosciences, Multidisciplinary SC Geology GA UV847 UT WOS:A1996UV84700025 ER PT J AU Williams, DF AF Williams, Dylan F. TI Thermal Noise in Lossy Waveguides SO IEEE TRANSACTIONS ON MICROWAVE THEORY AND TECHNIQUES LA English DT Article AB This work rigorously treats thermal electromagnetic noise in lossy waveguides and develops explicit modal equivalent-circuit representations for the noise generated by arbitrary passive networks embedded in them. The results show that the formulations in common use are limited tal lossless transmission media. C1 NIST, Boulder, CO 80303 USA. RP Williams, DF (reprint author), NIST, Boulder, CO 80303 USA. NR 14 TC 4 Z9 4 U1 0 U2 0 PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC PI PISCATAWAY PA 445 HOES LANE, PISCATAWAY, NJ 08855-4141 USA SN 0018-9480 J9 IEEE T MICROW THEORY JI IEEE Trans. Microw. Theory Tech. PD JUL PY 1996 VL 44 IS 7 BP 1067 EP 1073 AR PII S0018-9480(96)04707-2 DI 10.1109/22.508639 PN 1 PG 7 WC Engineering, Electrical & Electronic SC Engineering GA V28AX UT WOS:000208654800010 ER PT J AU Krupka, J Blondy, P Cros, D Guillon, P Geyer, RG AF Krupka, Jerzy Blondy, Pierre Cros, Dominique Guillon, Pierre Geyer, Richard G. TI Whispering-Gallery Modes and Permeability Tensor Measurements in Magnetized Ferrite Resonators SO IEEE TRANSACTIONS ON MICROWAVE THEORY AND TECHNIQUES LA English DT Article AB Whispering-gallery modes in axially magnetized ferrite disk samples have been studied using rigorous Rayleigh-Ritz and finite-element analyses. The influence of radial magnetization on the resonant frequencies of both WGE and WGH modes was investigated, both theoretically and experimentally. Permeability tensor components of biased ferrites were determined from measurements of the resonant frequencies of the WGH(n00) and the WGE(n00) mode families. C1 [Krupka, Jerzy] Politech Warszawska, Inst Mikroelekt & Optoelekt, Warsaw, Poland. [Blondy, Pierre; Cros, Dominique; Guillon, Pierre] Univ Limoges, Fac Sci, IRCOM, URA CNRS 356, F-87060 Limoges, France. [Geyer, Richard G.] NIST, Electromagnet Fields Div, Boulder, CO 80303 USA. RP Krupka, J (reprint author), Politech Warszawska, Inst Mikroelekt & Optoelekt, Koszykowa 7-5, Warsaw, Poland. NR 16 TC 8 Z9 8 U1 0 U2 1 PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC PI PISCATAWAY PA 445 HOES LANE, PISCATAWAY, NJ 08855-4141 USA SN 0018-9480 J9 IEEE T MICROW THEORY JI IEEE Trans. Microw. Theory Tech. PD JUL PY 1996 VL 44 IS 7 BP 1097 EP 1102 AR PII S0018-9480(96)04712-6 DI 10.1109/22.508643 PN 1 PG 6 WC Engineering, Electrical & Electronic SC Engineering GA V28AX UT WOS:000208654800014 ER PT J AU Parker, TE AF Parker, TE TI IEEE Ultrasonics, Ferroelectrics, and Frequency Control Society Distinguished Lecturer Award - The search for the perfect oscillator SO IEEE TRANSACTIONS ON ULTRASONICS FERROELECTRICS AND FREQUENCY CONTROL LA English DT Editorial Material RP Parker, TE (reprint author), NATL INST STAND & TECHNOL,DIV TIME & FREQUENCY,BOULDER,CO 80303, USA. NR 0 TC 0 Z9 0 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 0885-3010 J9 IEEE T ULTRASON FERR JI IEEE Trans. Ultrason. Ferroelectr. Freq. Control PD JUL PY 1996 VL 43 IS 4 BP 506 EP 506 DI 10.1109/TUFFC.1996.503706 PG 1 WC Acoustics; Engineering, Electrical & Electronic SC Acoustics; Engineering GA UW854 UT WOS:A1996UW85400002 ER PT J AU Magee, JW AF Magee, JW TI Isochoric p-rho-T measurements on difluoromethane (R32) from 142 to 396 K and pentafluoroethane (R125) from 178 to 398 K at pressures to 35 MPa SO INTERNATIONAL JOURNAL OF THERMOPHYSICS LA English DT Article DE difluoromethane; pentafluoroethane; p-rho-T data; saturated liquid; vapor pressure ID VAPOR-PRESSURES; DENSITIES AB The p-rho-T relationships were measured for difluoromethane (R32) and pentafluoroethane (R125) by an isochoric method with gravimetric determinations of the amount of substance. Temperatures ranged From 142 to 396 K For R32 and from 178 to 398 K for R125, while pressures were up to 35 MPa. Measurements were conducted on compressed liquid samples. Determinations of vapor pressures were made for each substance. I have used vapor pressure data and the p-rho-T data to estimate saturated liquid densities by extrapolating each isochore to the vapor pressure, and determining the temperature and density at the intersection. Published p-rho-T data are in good agreement with this study. For the p-rho-T apparatus, the uncertainty of the temperature is +/-0.03 K, and for pressure it is +/-0.01 % at p > 3 MPa and +/-0.05 % at p < 3 MPa. The principal sourer of uncertainty is the cell volume (28.5193 cm(3) at 0 K and 0 MPa), which has a standard uncertainty of +/- 0.003 cm(3). When all components of experimental uncertainty are considered, the expanded uncertainty (at the two-sigma level) of the density measurements is estimated to be 0.05 %. RP Magee, JW (reprint author), NATL INST STAND & TECHNOL,DIV THERMOPHYS,CHEM SCI & TECHNOL LAB,325 BROASWAY,BOULDER,CO 80303, USA. RI Magee, Joseph/A-8496-2009 OI Magee, Joseph/0000-0002-9312-8593 NR 19 TC 41 Z9 41 U1 0 U2 3 PU PLENUM PUBL CORP PI NEW YORK PA 233 SPRING ST, NEW YORK, NY 10013 SN 0195-928X J9 INT J THERMOPHYS JI Int. J. Thermophys. PD JUL PY 1996 VL 17 IS 4 BP 803 EP 822 DI 10.1007/BF01439191 PG 20 WC Thermodynamics; Chemistry, Physical; Mechanics; Physics, Applied SC Thermodynamics; Chemistry; Mechanics; Physics GA UY211 UT WOS:A1996UY21100005 ER PT J AU Luddecke, TO Magee, JW AF Luddecke, TO Magee, JW TI Molar heat capacity at constant volume of difluoromethane (R32) and pentafluoroethane (R125) from the triple-point temperature to 345 K at pressures to 35 MPa SO INTERNATIONAL JOURNAL OF THERMOPHYSICS LA English DT Article DE difluoromethane; enthalpy of fusion; heat capacity; pentafluoroethane; triple point; vapor pressure ID COMPRESSED LIQUID; DIPOLE-MOMENTS; REFRIGERANTS AB Molar heat capacities at constant volume (C-v) of difluoromethane (R32) and pentafluoroethane (R125) were measured with an adiabatic calorimeter. Temperatures ranged from their triple points to 345 K, and pressures up to 35 MPa. Measurements were conducted on the liquid in equilibrium with its vapor and on compressed liquid samples. The samples were of a high purity, verified by chemical analysis of each fluid. For the samples, calorimetric results were obtained for two-phase (C-v((2))), saturated liquid (C-sigma or C-x'), and single phase (C-v) molar heat capacities. The C-sigma data were used to estimate vapor pressures for values less than 0.3 MPa by applying a thermodynamic relationship between the saturated liquid heat capacity and the temperature derivatives of the vapor pressure. The triple-point temperature (T-tr) and the enthalpy of fusion (Delta(fus)H) were also measured for each substance. The principal sources of uncertainty are the temperature rise measurement and the change-of-volume work adjustment. The expanded uncertainty (at the two-sigma level) for C-v is estimated to be 0.7%, for C-v((2)) it is 0.5 %, and for C-sigma it is 0.7 %. C1 NATL INST STAND & TECHNOL,DIV THERMOPHYS,CHEM SCI & TECHNOL LAB,BOULDER,CO 80303. UNIV HANNOVER,INST THERMODYNAM,D-3000 HANNOVER,GERMANY. RI Magee, Joseph/A-8496-2009 OI Magee, Joseph/0000-0002-9312-8593 NR 15 TC 34 Z9 34 U1 0 U2 1 PU PLENUM PUBL CORP PI NEW YORK PA 233 SPRING ST, NEW YORK, NY 10013 SN 0195-928X J9 INT J THERMOPHYS JI Int. J. Thermophys. PD JUL PY 1996 VL 17 IS 4 BP 823 EP 849 DI 10.1007/BF01439192 PG 27 WC Thermodynamics; Chemistry, Physical; Mechanics; Physics, Applied SC Thermodynamics; Chemistry; Mechanics; Physics GA UY211 UT WOS:A1996UY21100006 ER PT J AU Weber, LA Silva, AM AF Weber, LA Silva, AM TI Design of a high-pressure ebulliometer, with vapor-liquid equilibrium results for the systems CHF2Cl+CF3-CH3 and CF3-CH2F+CH2F2 SO INTERNATIONAL JOURNAL OF THERMOPHYSICS LA English DT Article DE activity coefficients; chlorodifluoromethane (R22); difluoromethane (R32); ebulliometry; phase equilibrium; refrigerant mixtures; 1,1,1-trifluoroethane (R143a); 1,1,1,2-tetrafluoroethane (R134a) ID 1-CHLORO-1,2,2,2-TETRAFLUOROETHANE; COEFFICIENTS AB We describe the design and operation of a new high-pressure metal ebulliometer which can operate at pressures to at least 3 MPa in the range 220-400 K. Infinite-dilution activity coefficients are presented for the system CHF2Cl+CF3-CH3 at 275 K and for the system CF3-CH2F+CH2F2 at 260, 280, and 300 K. The Wilson activity coefficient model and a virial coefficient model are applied to these systems, and the phase equilibrium conditions are calculated. The results are shown to agree well with predicted and with published measured values. The excess enthalpy is calculated and compared with results from a Peng-Robinson equation of state. Vapor densities on the dew curves are given. RP Weber, LA (reprint author), NIST,CHEM SCI & TECHNOL LAB,DIV THERMOPHYS,GAITHERSBURG,MD 20899, USA. NR 22 TC 18 Z9 19 U1 1 U2 2 PU PLENUM PUBL CORP PI NEW YORK PA 233 SPRING ST, NEW YORK, NY 10013 SN 0195-928X J9 INT J THERMOPHYS JI Int. J. Thermophys. PD JUL PY 1996 VL 17 IS 4 BP 873 EP 888 DI 10.1007/BF01439194 PG 16 WC Thermodynamics; Chemistry, Physical; Mechanics; Physics, Applied SC Thermodynamics; Chemistry; Mechanics; Physics GA UY211 UT WOS:A1996UY21100008 ER PT J AU Sniegoski, LT Welch, MJ AF Sniegoski, LT Welch, MJ TI Interlaboratory studies on the analysis of hair for drugs of abuse: Results from the fourth exercise SO JOURNAL OF ANALYTICAL TOXICOLOGY LA English DT Article RP Sniegoski, LT (reprint author), NIST,CHEM SCI & TECHNOL LAB,DIV ANALYT CHEM,GAITHERSBURG,MD 20899, USA. NR 5 TC 13 Z9 14 U1 0 U2 1 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 JUL-AUG PY 1996 VL 20 IS 4 BP 242 EP 247 PG 6 WC Chemistry, Analytical; Toxicology SC Chemistry; Toxicology GA UX944 UT WOS:A1996UX94400006 PM 8835662 ER PT J AU Fukumoto, Y Moodenbaugh, AR Suenaga, M Fischer, DA Shibutani, K Hase, T Hayashi, S AF Fukumoto, Y Moodenbaugh, AR Suenaga, M Fischer, DA Shibutani, K Hase, T Hayashi, S TI Effect of oxygen partial pressure during postheat treatment on Bi2Sr2CaCu2Oy/Ag tapes SO JOURNAL OF APPLIED PHYSICS LA English DT Article AB Effects of oxygen partial pressure P-O2 during low temperature postheat treatments on the superconducting properties of silver-sheathed Bi2Sr2CaCu2Oy tapes were investigated. The critical temperature T-c of the resulting tapes changes systematically with P-O2. This variation of T-c is attributed to the change of electronic carrier (hole) concentration by the observation of oxygen K-edge absorption spectra. The intragranular critical current density J(c) is essentially unaffected by the heat treatment, while deterioration in grain connectivity is observed in the specimens treated in reduced-oxygen atmospheres. The change of anisotropy in J(c) with respect to crystallographic orientations is also quite small for the variation of P-O2. (C) 1996 American Institute of Physics. C1 NATL INST STAND & TECHNOL,MAT SCI & ENGN LAB,GAITHERSBURG,MD 20899. KOBE STEEL LTD,ELECTR RES LAB,NISHI KU,KOBE 65122,JAPAN. RP Fukumoto, Y (reprint author), BROOKHAVEN NATL LAB,DEPT APPL SCI,UPTON,NY 11973, USA. OI Moodenbaugh, Arnold/0000-0002-3415-6762 NR 12 TC 4 Z9 4 U1 0 U2 0 PU AMER INST PHYSICS PI WOODBURY PA CIRCULATION FULFILLMENT DIV, 500 SUNNYSIDE BLVD, WOODBURY, NY 11797-2999 SN 0021-8979 J9 J APPL PHYS JI J. Appl. Phys. PD JUL 1 PY 1996 VL 80 IS 1 BP 331 EP 335 DI 10.1063/1.362824 PG 5 WC Physics, Applied SC Physics GA UU532 UT WOS:A1996UU53200050 ER PT J AU Weber, LA Defibaugh, DE AF Weber, LA Defibaugh, DE TI Vapor pressure of 1,1,1,2,2-pentafluoropropane SO JOURNAL OF CHEMICAL AND ENGINEERING DATA LA English DT Article AB We have used a comparative ebulliometer to measure the vapor pressure of 1,1,1,2,2-pentafluoropropane (HFC245cb) in the temperature range (248 to 326) K. Pressures ranged from (74 to 995) kPa. The data were adjusted for impurities in the sample. The temperature of the normal boiling point was found to be (255.11 +/- 0.10) K, and the Fitter acentric factor was calculated to be 0.297. An estimate for the critical pressure is given, P-c = (3148 +/- 15) kPa. RP Weber, LA (reprint author), NATL INST STAND & TECHNOL,CHEM SCI & TECHNOL LAB,DIV THERMOPHYS,GAITHERSBURG,MD 20899, USA. NR 10 TC 6 Z9 6 U1 0 U2 2 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 JUL-AUG PY 1996 VL 41 IS 4 BP 762 EP 764 DI 10.1021/je950312v PG 3 WC Thermodynamics; Chemistry, Multidisciplinary; Engineering, Chemical SC Thermodynamics; Chemistry; Engineering GA UX159 UT WOS:A1996UX15900023 ER PT J AU Archer, DG AF Archer, DG TI Thermodynamic properties of synthetic otavite, CdCO3(cr): Enthalpy increment measurements from 4.5 K to 350 K SO JOURNAL OF CHEMICAL AND ENGINEERING DATA LA English DT Article ID NACL+H2O SYSTEM AB Enthalpy increments for cadmium carbonate were measured for temperatures from 4.5 K to 350 K with an adiabatic calorimeter. These measurements were used to compute the entropy, enthalpy relative to 0 K, and the heat capacity of cadmium carbonate. A small anomaly was observed for the sample in the temperature region from approximately 175 K to 265 K. Comparison of the calculated entropy for 298.15 K, 103.88 J . K-1. mol(-1), is made with other previously published reference values to arrive at a more precise and consistent set of thermodynamic properties for otavite. RP Archer, DG (reprint author), NIST,CHEM SCI & TECHNOL LAB,DIV CHEM KINET & THERMODYNAM,GAITHERSBURG,MD 20899, USA. NR 15 TC 5 Z9 5 U1 1 U2 1 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 JUL-AUG PY 1996 VL 41 IS 4 BP 852 EP 858 DI 10.1021/je960068n PG 7 WC Thermodynamics; Chemistry, Multidisciplinary; Engineering, Chemical SC Thermodynamics; Chemistry; Engineering GA UX159 UT WOS:A1996UX15900042 ER PT J AU Magee, JW Bruno, TJ AF Magee, JW Bruno, TJ TI Isochoric (p,rho,T) measurements for liquid toluene from 180 K to 400 K at pressures to 35 MPa SO JOURNAL OF CHEMICAL AND ENGINEERING DATA LA English DT Article ID DENSITIES; MIXTURES; HEPTANE AB The (p,rho,T) relationships were measured for a specially purified sample of toluene by applying an isochoric method with gravimetric determinations of the amount of substance. Temperatures ranged from 180 K to 400 K, while pressures were up to 35 MPa. Measurements were carried out on 20 compressed liquid isochores at a total of 311 state conditions. Saturated liquid densities were estimated by extrapolating each isochore to the vapor pressure, and determining the temperature and density at the intersection. Published (p,rho,T) data are in good agreement with this study. For the (p,rho,T) apparatus, the expanded uncertainty (at the 2 sigma level) of the temperature is +/-0.03 K, and for pressure it is +/-0.01% at p > 3 MPa and +/-0.05% at p < 3 MPa. The principal source of uncertainty is the cell volume (28.5193 cm(3) at 0 K and 0 MPa) which has an estimated statistical uncertainty (at the 1 sigma level) of +/-0.003 cm(3). When the sources of uncertainty are combined, the expanded uncertainty (at the 2 sigma level) of the density values is estimated to be +/-0.05%. RP Magee, JW (reprint author), NATL INST STAND & TECHNOL,CHEM SCI & TECHNOL LAB,PHYS & CHEM PROPERTIES DIV,325 BROADWAY,BOULDER,CO 80303, USA. RI Magee, Joseph/A-8496-2009 OI Magee, Joseph/0000-0002-9312-8593 NR 18 TC 23 Z9 23 U1 0 U2 4 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 JUL-AUG PY 1996 VL 41 IS 4 BP 900 EP 905 DI 10.1021/je960062y PG 6 WC Thermodynamics; Chemistry, Multidisciplinary; Engineering, Chemical SC Thermodynamics; Chemistry; Engineering GA UX159 UT WOS:A1996UX15900053 ER PT J AU Anderson, JL AF Anderson, JL TI A method for producing and evaluating probabilistic forecasts from ensemble model integrations SO JOURNAL OF CLIMATE LA English DT Article ID RANGE; PREDICTABILITY; VARIABILITY; ANALOGS; PREDICTION; FIELD; LONG AB The binned probability ensemble (BPE) technique is presented as a method for producing forecasts of the probability distribution of a variable using an ensemble of numerical model integrations. The ensemble forecasts Lire used to partition the real line into a number of bins, each of which has an equal probability of containing the ''true'' forecast. The method is tested for both a simple low-order dynamical system and a general circulation model (GCM) forced with observed sea surface temperatures (an ensemble of Atmospheric Model Intercomparison Project integrations). The BPE method can also be used to calculate the probability that probabilistic ensemble forecasts are consistent with the verifying observations. The method is not sensitive to the fact that the characteristics of the forecast probability distribution may change drastically for different initial condition (or boundary condition) probability distributions. For example, the method is capable of evaluating whether the variance of a set of ensemble forecasts is consistent with the verifying observed variance. Applying the method to the ensemble of boundary-forced GCM integrations demonstrates that the GCM produces probabilistic forecasts with too little variability for upper-level dynamical fields. Operational weather prediction centers including the U.K. Meteorological Office, the European Centre for Medium-Range Forecasts, and the National Centers for Environmental Prediction have been applying this method, referred to by them as Talagrand diagrams, to the verification of operational ensemble predictions. The BPE method only evaluates the consistency of ensemble predictions and observations and should be used in conjunction with additional verification tools to provide a complete assessment of a set of probabilistic forecasts. RP Anderson, JL (reprint author), PRINCETON UNIV,GEOPHYS FLUID DYNAM LAB,POB 308,PRINCETON,NJ 08542, USA. NR 36 TC 212 Z9 214 U1 1 U2 14 PU AMER METEOROLOGICAL SOC PI BOSTON PA 45 BEACON ST, BOSTON, MA 02108-3693 SN 0894-8755 J9 J CLIMATE JI J. Clim. PD JUL PY 1996 VL 9 IS 7 BP 1518 EP 1530 DI 10.1175/1520-0442(1996)009<1518:AMFPAE>2.0.CO;2 PG 13 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA VC209 UT WOS:A1996VC20900005 ER PT J AU Mo, KC Higgins, RW AF Mo, KC Higgins, RW TI Large-scale atmospheric moisture transport as evaluated in the NCEP/NCAR and the NASA/DAO reanalyses SO JOURNAL OF CLIMATE LA English DT Article ID HYDROLOGIC-CYCLE; EL-NINO; CIRCULATION; INTERPOLATION; RAINFALL; PACIFIC AB Large-scale aspects of the atmospheric moisture transport and the overall moisture budget are studied using data from the National Centers for Environmental Prediction (NCEP) reanalysis. Our objective is to critically evaluate the usefulness of the reanalysis products for studies of the global hydrologic cycle. The study period is from January 1985 to December 1993. Monthly mean water vapor transport, evaporation, and precipitation are compared to the NASA Data Assimilation Office (DAO) reanalysis for roughly the same period and with satellite estimates and station observations. Comparisons of the moisture flux fields form the NCEP and the DAO reanalyses show general agreement in most aspects, bur there are regional differences. Discrepancies in tropical moisture transport are largely due to uncertainties in the divergent winds. The DAO reanalysis shows a weaker Hadley circulation and weaker cross-equatorial flow, particularly during the Northern Hemisphere winter. Global patterns of evaporation from the two reanalyses are similar, but the NCEP values are higher over the oceans and lower over the landmasses. In the eastern Pacific, the DAO has less total precipitable water and less rainfall. While the large-scale features of precipitation from the reanalyses agree with each other and are within the envelope of the satellite rainfall estimates, regional differences are large. Both analyses show questionable features in the moisture flux divergence fields over North and South America that are to a large extent terrain related. Interannual variability related to the 1087-1989 ENSO cycle is well captured by both reanalyses, On intraseasonal timescales, the NCEP reanalysis has difficulty capturing the precipitation signal associated with the 30-60 day oscillation, but the moisture flux divergence from both reanalyses produces a more reasonable signal. An examination of the overall moisture budget for rectangular regions over North and South America in both reanalyses reveals large differences in the moisture flux divergence. Both reanalyses overestimate rainfall in the southeastern United States. The largest uncertainties during the spring and summer months are directly related to differences in the topographically bound low-level jets. RP Mo, KC (reprint author), NOAA,NATL WEATHER SERV,NCEP,ANAL BRANCH,CLIMATE PREDICT CTR,WASHINGTON,DC 20233, USA. NR 41 TC 115 Z9 119 U1 0 U2 7 PU AMER METEOROLOGICAL SOC PI BOSTON PA 45 BEACON ST, BOSTON, MA 02108-3693 SN 0894-8755 J9 J CLIMATE JI J. Clim. PD JUL PY 1996 VL 9 IS 7 BP 1531 EP 1545 DI 10.1175/1520-0442(1996)009<1531:LSAMTA>2.0.CO;2 PG 15 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA VC209 UT WOS:A1996VC20900006 ER PT J AU Chen, CT Roeckner, E Soden, BJ AF Chen, CT Roeckner, E Soden, BJ TI A comparison of satellite observations and model simulations of column-integrated moisture and upper-tropospheric humidity SO JOURNAL OF CLIMATE LA English DT Article ID GENERAL-CIRCULATION MODEL; SEA-SURFACE TEMPERATURE; RANGE WEATHER FORECASTS; WATER-VAPOR; PRECIPITABLE WATER; RELATIVE-HUMIDITY; RADIATION BUDGET; EUROPEAN CENTER; ECMWF MODEL; SENSITIVITY AB Water vapor distributions obtained from the fourth generation ECHAM general circulation model are compared with satellite observations of total precipitable water (TPW) from the: Special Sensor Microwave/Imager (SSM/I) and upper-tropospheric relative humidity (UTH) from TIROS-N Operational Vertical Sounder (TOVS). In general, the model simulations agree well with satellite observations of the climatological mean, seasonal variation, and interannual variation of moisture. There are, however, biases in the details. Underestimates in TPW and UTH are found off the west coast of continents, especially in the boreal summer over the eastern subtropical Pacific. These biases are related to both enhanced dry advection due to an excessively strong subtropical high and greater large-scale subsidence. A more intense tropical circulation in ECHAM4 is evidenced by the broadening of the high TPW and UTH zone that coincides with the equatorial convective regions. Additionally, interannual anomalies in equatorial UTH and TPW simulated by the model are found to be more sensitive to tropical SST anomalies than are the satellite data. The impact of changes in physical parameterizations upon the moisture distribution is also examined by comparing the simulations from the previous ECHAM3 and the current ECHAM4 models. The dry bias at the equator in ECHAM3 is related to the closure assumption used for deep convection, while the dry bias in UTH over the high-latitude winter hemisphere in ECHAM3 is a result of negative specific humidities produced by the spectral vapor advection scheme. With the new semi-Lagrangian advection scheme in ECHAM4, the simulated UTH over the same region becomes moister than TOVS observations suggest. The impact of discrepancies in the simulated water vapor distributions upon the radiation budget and cloud distribution in the model are also described. C1 MAX PLANCK INST METEOROL,HAMBURG,GERMANY. NOAA,GEOPHYS FLUID DYNAM LAB,PRINCETON,NJ. NR 58 TC 23 Z9 24 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 JUL PY 1996 VL 9 IS 7 BP 1561 EP 1585 DI 10.1175/1520-0442(1996)009<1561:ACOSOA>2.0.CO;2 PG 25 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA VC209 UT WOS:A1996VC20900008 ER PT J AU Strakna, TJ Jahanmir, S Allor, RL Kumar, KV AF Strakna, TJ Jahanmir, S Allor, RL Kumar, KV TI Influence of grinding direction on fracture strength of silicon nitride SO JOURNAL OF ENGINEERING MATERIALS AND TECHNOLOGY-TRANSACTIONS OF THE ASME LA English DT Article ID BRITTLE MATERIALS; CERAMICS; DAMAGE AB It is generally found that grinding transverse to the tensile stress direction in flexure bars subjected to four-point bending results in a lower strength compared to grinding in the longitudinal direction. In the present study standard flexure specimens made from a reaction-bonded and a sintered reaction-bonded silicon nitride (RBSN and SRBSN) were surface ground under three different conditions in both longitudinal and transverse directions to assess the effect of grinding direction on strength. Four point flexure tests were performed on the specimens mid Weibull parameters were calculated. The results showed that while the strength was not affected by the grinding condition when grinding was performed in the longitudinal direction, the strength of the samples ground in the transverse direction was reduced as the material removal rate was increased by a factor of 30. This result was confirmed by fractography, which showed that almost all the fracture initiation sires in the longitudinally ground samples were associated with near-surface microstructural features, whereas in the transverse ground samples fracture initiated from damage introduced bq grinding. The strength reduction by grinding in the transverse direction was found to be material dependent, and was larger for SRBSN than for RBSN. C1 FORD MOTOR CO,DEARBORN,MI 48152. GE CO,SUPERABRAS,WORTHINGTON,OH 43085. RP Strakna, TJ (reprint author), NIST,GAITHERSBURG,MD 20899, USA. NR 52 TC 17 Z9 17 U1 0 U2 1 PU ASME-AMER SOC MECHANICAL ENG PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 SN 0094-4289 J9 J ENG MATER-T ASME JI J. Eng. Mater. Technol.-Trans. ASME PD JUL PY 1996 VL 118 IS 3 BP 335 EP 342 DI 10.1115/1.2806815 PG 8 WC Engineering, Mechanical; Materials Science, Multidisciplinary SC Engineering; Materials Science GA UZ900 UT WOS:A1996UZ90000011 ER PT J AU Ahn, HS Wei, LH Jahanmir, S AF Ahn, HS Wei, LH Jahanmir, S TI Nondestructive detection of damage produced by a sharp indenter in ceramics SO JOURNAL OF ENGINEERING MATERIALS AND TECHNOLOGY-TRANSACTIONS OF THE ASME LA English DT Article ID ACOUSTIC MICROSCOPE; BRITTLE MATERIALS; SILICON-NITRIDE; CRACKS; MICROFRACTURE; SOLIDS AB The feasibility of an ultrasonic technique using normal-incident compressional waves and a thermal wave measurement technique was evaluated for their sensitivity to surface and subsurface damage in ceramics. Well-defined damage in the form of surface and subsurface cracks was introduced by Vickers indentation in soda-lime glass and silicon nitride. The indentation impressions were first examined by optical microscopy to identify the types of cracks and to measure the size of the indents and cracks. As expected, indentation produced median/radial cracks emanating from the ident corners and subsurface lateral cracks. The ultrasonic technique was successful in detecting the subsurface lateral cracks in both materials. The signals obtained by focusing the trandsucer into the material (i.e., defocusing) was used to estimate the depth of subsurface cracks. The lateral cracks and the median/radial cracks were detected by the thermal wave measurement technique using the optical beam deflection method. The lateral cracks and the median/radial cracks were identified separately by using two deflection components of the probe beam. The transverse deflection component of the probe beam was used for the detection of the median/radial cracks, whereas the normal deflection component was used for the detection of the lateral cracks. The results are discussed in terms of the applicability of these two techniques as nondestructive methods for the detection of machining-induced damage in ceramics. RP Ahn, HS (reprint author), NATL INST STAND & TECHNOL,DIV CERAM,GAITHERSBURG,MD 20899, USA. NR 31 TC 12 Z9 14 U1 0 U2 1 PU ASME-AMER SOC MECHANICAL ENG PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 SN 0094-4289 J9 J ENG MATER-T ASME JI J. Eng. Mater. Technol.-Trans. ASME PD JUL PY 1996 VL 118 IS 3 BP 402 EP 409 DI 10.1115/1.2806827 PG 8 WC Engineering, Mechanical; Materials Science, Multidisciplinary SC Engineering; Materials Science GA UZ900 UT WOS:A1996UZ90000022 ER PT J AU Ketcham, SA Niemiec, JM McKenna, GB AF Ketcham, SA Niemiec, JM McKenna, GB TI Extension and compression of elastomeric butt joint seals SO JOURNAL OF ENGINEERING MECHANICS-ASCE LA English DT Article ID RUBBER; BEHAVIOR; NETWORKS; STRAIN AB The conventional practice for the design of elastomeric butt joint seals in pavement and building expansion joints is based primarily on standard tests of model seals. The practice does not incorporate structural analysis and does not utilize mechanical properties of the sealant. This study concerns the applicability of a particular load versus deflection equation for the extension and compression design of these seals, i.e., the elementary large compression equation suggested by Payne in 1956 and Gent and Lindley in 1959 for bonded rubber blocks. The study demonstrates, using experiments to measure strain energy density functions for two sealants, by application of these functions in finite-element analyses and by comparison of the finite-element and elementary analysis results, the capabilities and limitations of the load versus deflection equation. In the process, the study introduces an efficient experimental technique for evaluating coefficients of the Rivlin strain energy density polynomial for general application to the analysis of elastomeric structures, and demonstrates the utility of the finite-element-based approach for extension and compression analysis of buff joint seals. C1 NATL INST STAND & TECHNOL,DIV POLYMERS,STRUCT & MECH GRP,GAITHERSBURG,MD 20899. RP Ketcham, SA (reprint author), USA,COLD REG RES & ENGN LAB,72 LYME RD,HANOVER,NH 03755, USA. RI McKenna, Gregory/O-1134-2013 OI McKenna, Gregory/0000-0002-5676-9930 NR 21 TC 6 Z9 6 U1 0 U2 3 PU ASCE-AMER SOC CIVIL ENG 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 JUL PY 1996 VL 122 IS 7 BP 669 EP 677 DI 10.1061/(ASCE)0733-9399(1996)122:7(669) PG 9 WC Engineering, Mechanical SC Engineering GA UR831 UT WOS:A1996UR83100009 ER PT J AU Forward, RB Burke, JS Rittschof, D Welch, JM AF Forward, RB Burke, JS Rittschof, D Welch, JM TI Photoresponses of larval Atlantic menhaden (Brevoortia tyrannus Latrobe) in offshore and estuarine waters: Implications for transport SO JOURNAL OF EXPERIMENTAL MARINE BIOLOGY AND ECOLOGY LA English DT Article DE Atlantic menhaden; Brevoortia tyrannus; chemical cues; larvae; photoresponses; shadow response ID NORTH-CAROLINA ESTUARY; GLASS-EELS; FISHES; MIGRATION; CRUSTACEAN; ANGUILLA; STREAM AB This study tested the hypothesis that Atlantic menhaden (Brevoortia tyrannus Latrobe) larvae have separate behaviors in offshore and estuarine waters that are evoked by chemical cues in these waters. Atlantic menhaden spawn offshore, and larvae are transported shoreward where they metamorphose after entering estuaries. Field studies suggest that during the day larvae are at moderate depths offshore and less abundant in the water column than at night in estuaries. Since photoresponse may contribute to these depth distributions, they were tested in the laboratory in a light field that mimicked the underwater angular light distribution. Responses were quantified as the proportion of larvae swimming in the upper portion of a water column containing either offshore or estuarine water at the same salinity and temperature. Swimming varied significantly with water type. Young larvae (<8 mm total length (TL)) swam near the surface in estuarine water and lower in offshore water. Older larvae (14-16 mm TL) showed the opposite responses. Since the test waters only differed in chemical composition, the results supported the hypothesis. In addition, the study characterized the predator avoidance shadow response, in which larvae descend in response to a decrease in light intensity. The shadow response did not change with larval age and was very similar in offshore and estuarine water. The minimum percent decrease in light intensity to evoke the descent response ranged from 37-50%. Young larvae descended primarily by passive sinking. Older larvae sank upon small decreases in intensity, but actively swam down in response to large intensity decreases. Thus, water type induced positional changes in a water column which may reflect the vertical position necessary for horizontal transport in offshore and estuarine areas by different age larvae. In contrast, the shadow response remained consistent, which suggests the predator threat is the same in offshore and estuarine areas and does not change with larval age. C1 NOAA,NATL MARINE FISHERIES SERV,SE FISHERIES CTR,BEAUFORT LAB,BEAUFORT,NC 28516. RP Forward, RB (reprint author), DUKE UNIV,MARINE LAB,SCH ENVIRONM,135 DUKE MARINE LAB RD,BEAUFORT,NC 28516, USA. NR 39 TC 21 Z9 22 U1 1 U2 6 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0022-0981 J9 J EXP MAR BIOL ECOL JI J. Exp. Mar. Biol. Ecol. PD JUL PY 1996 VL 199 IS 1 BP 123 EP 135 DI 10.1016/0022-0981(95)00180-8 PG 13 WC Ecology; Marine & Freshwater Biology SC Environmental Sciences & Ecology; Marine & Freshwater Biology GA VB479 UT WOS:A1996VB47900009 ER PT J AU Fraser, BJ Singer, HJ Hughes, WJ Wygant, JR Anderson, RR Hu, YD AF Fraser, BJ Singer, HJ Hughes, WJ Wygant, JR Anderson, RR Hu, YD TI CRRES Poynting vector observations of electromagnetic ion cyclotron waves near the plasmapause SO JOURNAL OF GEOPHYSICAL RESEARCH-SPACE PHYSICS LA English DT Article ID ELECTRIC-FIELD OBSERVATIONS; 1-2 MAGNETIC PULSATIONS; EQUATORIAL MAGNETOSPHERE; PARTICLE INTERACTIONS; SYNCHRONOUS ORBIT; GROUND-SATELLITE; HIGH-LATITUDES; PC-1 WAVES; AMPLIFICATION; GEOS-1 AB Electromagnetic ion cyclotron waves have been observed by the Air Force Geophysics Laboratory triaxial fluxgate magnetometer on the CRRES satellite in the vicinity of the plasmapause. Specific wave events in the 1300-0100 MLT local time sector and over L = 4.8 - 6.7 at magnetic latitudes between +/- 20 degrees have been studied with respect to energy propagation. Using the wave magnetic field data and the orthogonal two-component Berkeley electric field experiment data allows the computation of the Poynting vector. Nine events with frequencies below 0.6 Hz have been analyzed. General wave properties showed intensities in the range 4 - 18 mu W m(-2). In most events, energy propagation was predominantly away from the equator, supporting the existence of an equatorial source region. There are exceptions and one event, observed 3 degrees from the equator, also showed some propagation back to the equator with equal energy. Four periodic wave packets were seen in another event. This event showed unidirectional propagation away from the equator over all packets with periodicity approximately one-half of the calculated time for a typical bouncing wave packet. Consequently, the periodicity is not the signature of a classical periodic structured Pc 1-2 pulsation event of the type seen on the ground. Generally, the results for these waves with f < f(He)+ may be interpreted by assuming an ion cyclotron instability source located near the equator and irregularly emitting wave trains of energy into one or both hemispheres, with minimal reflection at the ionosphere. C1 UNIV IOWA,DEPT PHYS & ASTRON,IOWA CITY,IA 52242. BOSTON UNIV,CTR SPACE PHYS,BOSTON,MA 02215. NOAA,SPACE ENVIRONM LAB,BOULDER,CO 80303. UNIV CALIF BERKELEY,SPACE SCI LAB,BERKELEY,CA 94720. PHILIPS LABS,GEOPHYS DIRECTORATE GPSG,BEDFORD,MA. BOSTON UNIV,CTR SPACE RES,BOSTON,MA 02215. UNIV NEWCASTLE,DEPT PHYS,CALLAGHAN,NSW 2308,AUSTRALIA. NR 40 TC 75 Z9 76 U1 0 U2 1 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 SN 0148-0227 J9 J GEOPHYS RES JI J. Geophys. Res-Space Phys. PD JUL 1 PY 1996 VL 101 IS A7 BP 15331 EP 15343 DI 10.1029/95JA03480 PG 13 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA UV415 UT WOS:A1996UV41500011 ER PT J AU Vandas, M Fischer, S Dryer, M Smith, Z Detman, T AF Vandas, M Fischer, S Dryer, M Smith, Z Detman, T TI Parametric study of loop-like magnetic cloud propagation SO JOURNAL OF GEOPHYSICAL RESEARCH-SPACE PHYSICS LA English DT Article ID SOLAR ENERGETIC PARTICLES; MAGNETOSPHERE; DYNAMICS AB Propagation and evolution of loop-like magnetic clouds in the ambient 1 solar wind flow are studied self-consistently using ideal MHD equations in the 2 1/2-dimensional approximation. Magnetic clouds, as ideal for ce-free objects (cylinders lying in the ecliptic plane), are ejected near the Sun and followed beyond the Earth's orbit. We investigate the influence of various initial parameters, like the injection velocity or different steady states of the solar wind, on their propagation and evolution, Simulation results are compared with an analytical theory of magnetic cloud evolution (expansion) published by Osherovich et al, [1993a, b]; good agreement is found, although no need to use a polytropic index less than 1 (as in the analytical approach) is required. C1 NOAA,SPACE ENVIRONM LAB,SPACE ENVIRONM CTR,R E SE,BOULDER,CO 80303. RP Vandas, M (reprint author), ACAD SCI CZECH REPUBL,INST ASTRON,BOCNI II 1401,CR-14131 PRAGUE 4,CZECH REPUBLIC. RI Vandas, Marek/G-9054-2014; xue, yansheng/A-9712-2012 NR 26 TC 23 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 JI J. Geophys. Res-Space Phys. PD JUL 1 PY 1996 VL 101 IS A7 BP 15645 EP 15652 DI 10.1029/96JA00511 PG 8 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA UV415 UT WOS:A1996UV41500039 ER PT J AU Aruliah, AL Farmer, AD FullerRowell, TJ Wild, MN Hapgood, M Rees, D AF Aruliah, AL Farmer, AD FullerRowell, TJ Wild, MN Hapgood, M Rees, D TI An equinoctial asymmetry in the high-latitude thermosphere and ionosphere SO JOURNAL OF GEOPHYSICAL RESEARCH-SPACE PHYSICS LA English DT Article ID INTERPLANETARY MAGNETIC-FIELD; SOLAR-CYCLE VARIATIONS; ELECTRIC-FIELD; Y-COMPONENT; GLOBAL-MODEL; IMF; POLAR; DEPENDENCE; CONVECTION; WINDS AB A large equinoctial asymmetry has been observed in thermospheric winds and ion velocities at high latitude sites in northern Scandinavia. Throughout the solar cycle, average nighttime thermospheric meridional winds are larger in spring than autumn despite similar levels of solar insolation. The average ion velocities are also larger in spring than autumn at solar maximum, but at solar minimum this position is reversed. Numerical simulations of the thermosphere and ionosphere have not predicted such asymmetries because they generally assume forcing functions that are symmetric about the solstices. The proposed explanation lies in the annual and diurnal variation in solar wind-magnetosphere coupling caused by changes in the orientation of the geomagnetic pole, and hence the magnetosphere, with respect to the average orientation of the IMF (the Russell-McPherron effect). This causes a 12-hour phase difference between the times of maximum solar wind-magnetosphere coupling at the two equinoxes. In addition, the orientation of the geomagnetic axis with respect to the average IMF is such that >0 for the March equinox and <0 for September. This results in a further source of asymmetry of forcing of the high-latitude ionosphere as the result of electric fields associated with the four sign combinations of B-y and B-z. Several predictions arise from the explanation given: for example, a high-latitude station measuring thermospheric neutral winds in Alaska, 180 degrees in longitude from Kiruna, might be expected to see nighttime thermospheric winds that are larger in the autumn than in the spring. C1 NOAA, SPACE ENVIRONM LAB, BOULDER, CO 80303 USA. RUTHERFORD APPLETON LAB, CHILTON OX11 0QX, OXON, ENGLAND. RP Aruliah, AL (reprint author), UCL, DEPT PHYS & ASTRON, ATMOSPHER PHYS LAB, 67-73 RIDING HOUSE ST, LONDON W1P 7PP, ENGLAND. RI Hapgood, Mike/D-6269-2014 OI Hapgood, Mike/0000-0002-0211-0241 NR 50 TC 19 Z9 19 U1 0 U2 4 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 0148-0227 J9 J GEOPHYS RES-SPACE JI J. Geophys. Res-Space Phys. PD JUL 1 PY 1996 VL 101 IS A7 BP 15713 EP 15722 DI 10.1029/95JA01102 PG 10 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA UV415 UT WOS:A1996UV41500045 ER PT J AU Croley, TE AF Croley, Thomas E., II TI USING NOAA's NEW CLIMATE OUTLOOKS IN OPERATIONAL HYDROLOGY SO JOURNAL OF HYDROLOGIC ENGINEERING LA English DT Article ID FORECASTS; ENSO AB The National Oceanic and Atmospheric Administration (NOAA) Climate Prediction Center recently began issuing new multiple long-lead outlooks of meteorological probabilities. Operational hydrology approaches for generating probabilistic hydrological outlooks must be compatible with these meteorological outlooks yet preserve spatial and temporal relationships observed in past meteorology. Many approaches, however, either limit the use of historical data to be compatible with meteorological outlooks or limit compatibility with the outlooks to allow fuller use of historical data. An operational hydrology approach that uses all historical data while remaining compatible with many of the new long-lead outlooks, in order of user priority, is described here. The approach builds a hypothetical very large structured set of possible future scenarios, to be treated as a "sample" from which to estimate outlook probabilities and other parameters. The use of this hypothetical set corresponds to the weighted use of a scenario set based on historical data. The determination of weights becomes an optimization problem for the general case. An example illustrates the concepts and method. C1 NOAA, Great Lakes Environm Res Lab, Ann Arbor, MI 48105 USA. RP Croley, TE (reprint author), NOAA, Great Lakes Environm Res Lab, 2205 Commonwealth Blvd, Ann Arbor, MI 48105 USA. NR 19 TC 18 Z9 18 U1 0 U2 4 PU ASCE-AMER SOC CIVIL ENGINEERS PI RESTON PA 1801 ALEXANDER BELL DR, RESTON, VA 20191-4400 USA SN 1084-0699 J9 J HYDROL ENG JI J. Hydrol. Eng. PD JUL PY 1996 VL 1 IS 3 BP 93 EP 102 DI 10.1061/(ASCE)1084-0699(1996)1:3(93) PG 10 WC Engineering, Civil; Environmental Sciences; Water Resources SC Engineering; Environmental Sciences & Ecology; Water Resources GA V15AE UT WOS:000207774100001 ER PT J AU Turchinskaya, M Kaiser, DL Shapiro, AJ Riley, GN Christopherson, C AF Turchinskaya, M Kaiser, DL Shapiro, AJ Riley, GN Christopherson, C TI Nondestructive magneto-optical imaging analysis of superconducting (Bi,Pb)(2)Sr2Ca2Cu3Ox composites SO JOURNAL OF MATERIALS RESEARCH LA English DT Article ID MAGNETIZATION; BOUNDARIES AB The superconducting filaments in (Bi, Pb)(2)Sr2Ca2Cu3Ox/Ag composite tapes have been imaged directly through the outer silver sheath of an unpolished tape by means of a magneto-optical imaging technique. The images reveal the morphology and alignment of the uppermost layer of filaments located as much as 112 mu m below the unpolished tape surface, the depths of these filaments, and the homogeneity of the magnetic flux distribution within these filaments. These results demonstrate that the magneto-optical technique is a valuable nondestructive tool for analyzing (Bi, Pb)(2)Sr2Ca2CU3Ox composite tapes. C1 AMER SUPERCONDUCTOR CORP,WESTBOROUGH,MA 01581. RP Turchinskaya, M (reprint author), NIST,MAT SCI & ENGN LAB,GAITHERSBURG,MD 20899, USA. NR 12 TC 3 Z9 3 U1 0 U2 0 PU MATERIALS RESEARCH SOCIETY PI PITTSBURGH PA 9800 MC KNIGHT ROAD SUITE 327, PITTSBURGH, PA 15237 SN 0884-2914 J9 J MATER RES JI J. Mater. Res. PD JUL PY 1996 VL 11 IS 7 BP 1597 EP 1600 DI 10.1557/JMR.1996.0199 PG 4 WC Materials Science, Multidisciplinary SC Materials Science GA UX157 UT WOS:A1996UX15700001 ER PT J AU Xu, HHK Jahanmir, S Ives, LK AF Xu, HHK Jahanmir, S Ives, LK TI Material removal and damage formation mechanisms in grinding silicon nitride SO JOURNAL OF MATERIALS RESEARCH LA English DT Article AB Surface grinding was performed on two silicon nitrides with different microstructures. The ground surfaces of both materials were observed with scanning electron microscopy (SEM) to consist of areas of microfracture, smeared areas, and areas covered with fine debris particles. It was determined that microfracture is the primary mechanism for material removal. Subsurface grinding damage was revealed by a bonded-interface technique to take the form of median-type cracks extending from the plastic zones. Distributed intergranular microcracks and intragrain twin/slip bands were observed within the plastic zones. The strengths of transverse-ground specimens were measured in four-point flexure. For the silicon nitride with a fine grain size and a mildly rising toughness-curve, grinding damage resulted in a drastic strength degradation compared to polished specimens. In contrast, the silicon nitride with large and elongated grains and a steeply rising toughness curve showed relatively little strength loss. The relationship between the ceramic microstructure and the damage tolerance in abrasive machining is discussed in light of these results. RP Xu, HHK (reprint author), NIST,DIV CERAM,GAITHERSBURG,MD 20899, USA. NR 24 TC 65 Z9 69 U1 1 U2 5 PU MATERIALS RESEARCH SOCIETY PI PITTSBURGH PA 9800 MC KNIGHT ROAD SUITE 327, PITTSBURGH, PA 15237 SN 0884-2914 J9 J MATER RES JI J. Mater. Res. PD JUL PY 1996 VL 11 IS 7 BP 1717 EP 1724 DI 10.1557/JMR.1996.0215 PG 8 WC Materials Science, Multidisciplinary SC Materials Science GA UX157 UT WOS:A1996UX15700017 ER PT J AU Choi, CS Staker, M AF Choi, CS Staker, M TI Neutron diffraction texture study of deformed uranium plates SO JOURNAL OF MATERIALS SCIENCE LA English DT Article AB The texture of two depleted uranium (DU) samples, labelled DUWR and DUWR2, were studied by neutron diffraction. DUWR was prepared by warm rolling of a cast ingot, and DUWR2 was prepared by adding 20% tensile strain to the warm-rolled DUWR. Complete three-dimensional orientation distribution functions were determined using four neutron pole figures for the DUWR, and using six neutron pole figures for the DUWR2 sample, by the WIMV method of the program popLA. The textures of the two samples were essentially identical to each other. They could be described by a twisted helical density tube spiralling continuously along the psi-axis of the Euler space. The projection of the backbone of the density tube along the theta-axis cast a linear shadow running parallel to the diagonal of the phi-psi plane, which could be defined by a phi = psi + 90 degrees (and phi = psi + 270 degrees) relation. The helical tube was confined with in narrow theta-angle limits, from 14 degrees to 30 degrees with the peak orientation at (103) [010]. The diffraction patterns of the DUWR2 sample were measured from the normal direction to the rolling surface of the sample, up to the scattering angle of 108 degrees using a 0.15 nm neutron beam. The Rietveld profile refinement using the textured diffraction pattern was quite satisfactory when the texture effect to the entire diffraction profile was corrected for by the corresponding pole density from the inverse pole figure. C1 NIST,DIV REACTOR RADIAT,GAITHERSBURG,MD 20899. USA,RES LAB,ABERDEEN PROVING GROUND,MD. RP Choi, CS (reprint author), ARDEC,ENERGET & WARHEADS DIV,PICATINNY ARSENAL,NJ 07806, USA. NR 8 TC 9 Z9 9 U1 0 U2 4 PU CHAPMAN HALL LTD PI LONDON PA 2-6 BOUNDARY ROW, LONDON, ENGLAND SE1 8HN SN 0022-2461 J9 J MATER SCI JI J. Mater. Sci. PD JUL 1 PY 1996 VL 31 IS 13 BP 3397 EP 3402 PG 6 WC Materials Science, Multidisciplinary SC Materials Science GA UX695 UT WOS:A1996UX69500008 ER PT J AU Yokoyama, K Lineberger, WC Yamada, KMT AF Yokoyama, K Lineberger, WC Yamada, KMT TI A breakdown of the Watson-Type Hamiltonian for some asymmetric-top molecules: The case of the spin-multiplet state SO JOURNAL OF MOLECULAR SPECTROSCOPY LA English DT Article AB A breakdown of the standard Watson-type rotational Hamiltonian was suggested for a molecule with H(2)XYZ structure [S. Urban and K. M. T. Yamada, J. Mel. Spectrosc. 160, 279-288 (1993)]. This breakdown is due to a near-resonant interaction between the ground state rotational levels and rotational levels in an excited vibrational state. This interaction has been observed in the excited electronic state of H2CCC- ((2)A(1) state) by high-resolution autodetachment spectroscopy. The centrifugal distortion coupling term and nonvanishing matrix elements for electronic spin doublet and tripler states are described using Hund's case (b) basis sets. The results are used to interpret the centrifugal distortion couplings between the nu(6) and nu(9) modes and the vibrational ground states in H2CCC-. Centrifugal distortion coupling constants C-6(ac) = 1.0723(2) x 10(-4) and C-9(ab) = -1.5397(5) x 10(-5) were obtained for this system. (C) 1996 Academic Press, Inc. C1 UNIV COLORADO,DEPT CHEM & BIOCHEM,BOULDER,CO 80309. NATL INST STAND & TECHNOL,BOULDER,CO 80309. NATL INST ADV INTERDISCIPLINARY RES,TSUKUBA,IBARAKI 305,JAPAN. RP Yokoyama, K (reprint author), UNIV COLORADO,JOINT INST LAB ASTROPHYS,BOULDER,CO 80309, USA. NR 10 TC 2 Z9 2 U1 0 U2 2 PU ACADEMIC PRESS INC JNL-COMP SUBSCRIPTIONS PI SAN DIEGO PA 525 B ST, STE 1900, SAN DIEGO, CA 92101-4495 SN 0022-2852 J9 J MOL SPECTROSC JI J. Mol. Spectrosc. PD JUL PY 1996 VL 178 IS 1 BP 93 EP 98 DI 10.1006/jmsp.1996.0161 PG 6 WC Physics, Atomic, Molecular & Chemical; Spectroscopy SC Physics; Spectroscopy GA UX808 UT WOS:A1996UX80800013 ER PT J AU Chase, MW AF Chase, MW TI NIST-JANAF thermochemical tables for the bromine oxides SO JOURNAL OF PHYSICAL AND CHEMICAL REFERENCE DATA LA English DT Review DE bromine oxides; evaluated recommended data; literature survey; spectroscopic properties; thermodynamic properties ID POLYATOMIC TRANSIENT MOLECULES; NEAR-ULTRAVIOLET SPECTROSCOPY; ELECTRON RESONANCE SPECTRA; ABSORPTION FINE-STRUCTURE; LOWER ARCTIC ATMOSPHERE; FREE-RADICAL REACTIONS; CODATA TASK GROUP; K-EDGE EXAFS; ANTARCTIC OZONE; PHOTOCHEMICAL DATA AB The thermodynamic and spectroscopic properties of the bromine oxide species have been reviewed. Recommended NIST-JANAF Thermochemical Tables are given for six gaseous bromine oxides: BrO, BBrO, BrOO, BrOBr, BrBrO, and BrO3. Sufficient information is not available to generate thermochemical tables for any condensed phase species. Annotated bibliographies (over 280 references) are provided for all neutral bromine oxides which have been reported in the literature. There are needs for additional experimental and theoretical data to reduce the uncertainties in the recommended values for these six species. Of all the species mentioned in the literature, many have not been isolated and characterized. In fact some do not exist. Throughout this paper, uncertainties attached to recommended values correspond to the uncertainty interval, equal to twice the standard deviation of the mean. (C) 1996 American Institute of Physics and American Chemical Society. RP Chase, MW (reprint author), NATL INST STAND & TECHNOL, STANDARD REFERENCE DATA PROGRAM, GAITHERSBURG, MD 20899 USA. NR 356 TC 50 Z9 50 U1 2 U2 10 PU AMER INST PHYSICS PI MELVILLE PA CIRCULATION & FULFILLMENT DIV, 2 HUNTINGTON QUADRANGLE, STE 1 N O 1, MELVILLE, NY 11747-4501 USA SN 0047-2689 J9 J PHYS CHEM REF DATA JI J. Phys. Chem. Ref. Data PD JUL-AUG PY 1996 VL 25 IS 4 BP 1069 EP 1111 PG 43 WC Chemistry, Multidisciplinary; Chemistry, Physical; Physics, Multidisciplinary SC Chemistry; Physics GA VJ029 UT WOS:A1996VJ02900001 ER PT J AU Kleiner, I Lovas, FJ Godefroid, M AF Kleiner, I Lovas, FJ Godefroid, M TI Microwave spectra of molecules of astrophysical interest .23. Acetaldehyde SO JOURNAL OF PHYSICAL AND CHEMICAL REFERENCE DATA LA English DT Article DE acetaldehyde; internal rotation; interstellar molecule; microwave spectrum; radio astronomy; rotational transitions ID MILLIMETER-WAVE SPECTRUM; CENTRIFUGAL-DISTORTION; INTERNAL-ROTATION; TORSIONAL STATES; DIPOLE-MOMENT AB The microwave spectrum of acetaldehyde is critically reviewed and supplemented with spectral frequency calculations derived from the rotation-internal rotation analysis. A simultaneous analysis of the torsional ground state, upsilon(t) = 0, and first and second torsionally excited states, upsilon(t) = 1 and 2, was carried out. The primary objective of this review is to provide radio astronomers with complete spectral coverage over the range of 900 MHz to 500 GHz for the ground state and covering rotational quantum number, J, from 0 to 26. (C) 1996 American Institute of Physics and American Chemical Society. C1 UNIV PARIS 11,LAB PHYS MOL & APPLICAT,PARIS,FRANCE. NATL INST STAND & TECHNOL,DIV MOL PHYS,GAITHERSBURG,MD 20899. FREE UNIV BRUSSELS,LAB CHIM PHYS MOL,B-1050 BRUSSELS,BELGIUM. RP Kleiner, I (reprint author), UNIV PARIS 06,LAB PHYS MOL & APPLICAT,CNRS,UNITE PROPRE,TOUR 13,BTE 76,4 PL JUSSIEU,F-75252 PARIS 05,FRANCE. NR 26 TC 36 Z9 36 U1 3 U2 11 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 JUL-AUG PY 1996 VL 25 IS 4 BP 1113 EP 1210 PG 98 WC Chemistry, Multidisciplinary; Chemistry, Physical; Physics, Multidisciplinary SC Chemistry; Physics GA VJ029 UT WOS:A1996VJ02900002 ER PT J AU Cokelet, ED Schall, ML Dougherty, DM AF Cokelet, ED Schall, ML Dougherty, DM TI ADCP-referenced geostrophic circulation in the Bering Sea basin SO JOURNAL OF PHYSICAL OCEANOGRAPHY LA English DT Article ID ALASKAN STREAM; CURRENT SYSTEM; NORTH PACIFIC; VARIABILITY; OCEAN; EXCHANGE; STRAIT; SLOPE; FLOW AB A month-long circumnavigation of the Bering Sea basin in August 1991 was designed to study the basin-scale circulation. For the first time in this region vessel-mounted acoustic Doppler current profiler (ADCP) measurements provided an absolute reference for geostrophic currents. Transport in the Alaskan Stream (0/1500 db) was 24 Sv (Sv = 10(6) m(3) s(-1)) westward, considerably higher than the 10-15 Sv usually inferred from geostrophic calculations referred to 1500 db, but in good agreement with previous work relative to moored current meters. As previously reported, the stream separated from the Aleutian Ridge, forming an anticyclonic eddy that restricted inflow to the Bering Sea. Flow through the Aleutians varied substantially across the passes. The Kamchatka Current was traceable for 800 km until it left the Bering Sea carrying 14 Sv (0/3000 db). Eddies were detected from the clustering of centers of curvature of sequential ADCP vectors. Incompletely spanned eddies can bias transports. Counterrotating eddy pairs deflected and entrained Kamchatka Current water and transported it to the basin interior. C1 UNIV WASHINGTON,JISAO,SEATTLE,WA 98195. RP Cokelet, ED (reprint author), NOAA,PACIFIC MARINE ENVIRONM LAB,7600 SAND POINT WAY NE,SEATTLE,WA 98115, USA. NR 47 TC 34 Z9 38 U1 1 U2 6 PU AMER METEOROLOGICAL SOC PI BOSTON PA 45 BEACON ST, BOSTON, MA 02108-3693 SN 0022-3670 J9 J PHYS OCEANOGR JI J. Phys. Oceanogr. PD JUL PY 1996 VL 26 IS 7 BP 1113 EP 1128 DI 10.1175/1520-0485(1996)026<1113:ARGCIT>2.0.CO;2 PG 16 WC Oceanography SC Oceanography GA VB317 UT WOS:A1996VB31700001 ER PT J AU Forbes, C Brown, O AF Forbes, C Brown, O TI Assimilation of sea surface height data into an isopycnic ocean model SO JOURNAL OF PHYSICAL OCEANOGRAPHY LA English DT Article ID SATELLITE ALTIMETER-DATA; BRAZIL-MALVINAS CONFLUENCE; FLUX-CORRECTED TRANSPORT; PRIMITIVE EQUATION MODEL; WARM-CORE RING; GULF-STREAM; GENERAL-CIRCULATION; VARIATIONAL ASSIMILATION; ATLANTIC-OCEAN; KALMAN FILTER AB Two different methods for assimilating sea surface height data into an isopycnic primitive equation model were developed and tested for the idealized case of an analytical Gaussian warm core (anticyclonic) eddy; then implemented using remotely sensed data from the Brazil-Malvinas confluence region. The first method makes a geostrophic assumption about the flow to relate sea surface height field gradients to the model velocities. The second method nudges the model sea surface height itself toward the observed values using a linear vertical influence function in the upper layers. The relationship between the surface height observations and the layer interface displacements is derived from observations of eddies in different regions of the Atlantic Ocean. Both assimilation methods were successful in transferring the dynamical influence of the sea surface height measurements deep into the water column, but a combination of both gave the best results. The application of both methods reproduced the detailed mesoscale features of the real oceanic circulation when assimilating Geosat sea surface height measurements from the Brazil-Malvinas confluence region into an isopycnic ''box'' ocean model. The velocity fields show deep anticyclonic (cyclonic) circulations of 66 cm s(-1) (52 cm s(-1)), which are present in observations of eddies and meanders. When compared to the no assimilation run, the assimilated sea surface height held exhibits a richer spectrum, with energy in all spectral bands strongly correlated with the observed values. The resulting band of energy higher than 150 cm(2) between 300 and 600 km is in agreement with previous studies of this region. The rms error between the model sea surface height and the Geosat data was reduced from similar to 13 cm in the no assimilation run to 2 cm rms after the assimilation. These experiments demonstrate the flexibility and effectiveness of the Newtonian relaxation (nudging) method for assimilating real data into a complex, multilayer primitive equation ocean model. C1 UNIV MIAMI, ROSENSTIEL SCH MARINE & ATMOSPHER SCI, MIAMI, FL 33149 USA. RP NOAA, ATLANTIC OCEANOG & METEOROL LAB, ENVIRONM RES LABS, PHOD, 4301 RICKENBACKER CAUSEWAY, MIAMI, FL 33149 USA. RI Brown, Otis/C-7188-2015 OI Brown, Otis/0000-0003-3111-1507 NR 67 TC 3 Z9 3 U1 0 U2 1 PU AMER METEOROLOGICAL SOC PI BOSTON PA 45 BEACON ST, BOSTON, MA 02108-3693 USA SN 0022-3670 EI 1520-0485 J9 J PHYS OCEANOGR JI J. Phys. Oceanogr. PD JUL PY 1996 VL 26 IS 7 BP 1189 EP 1213 DI 10.1175/1520-0485(1996)026<1189:AOSSHD>2.0.CO;2 PG 25 WC Oceanography SC Oceanography GA VB317 UT WOS:A1996VB31700006 ER PT J AU PolkowskaMotrenko, H Dybczynski, R Danko, B Becker, DA AF PolkowskaMotrenko, H Dybczynski, R Danko, B Becker, DA TI Very accurate, simultaneous determination of trace amounts of Co and Ni in biological materials by radiochemical neutron activation analysis SO JOURNAL OF RADIOANALYTICAL AND NUCLEAR CHEMISTRY-ARTICLES LA English DT Article ID DEFINITIVE METHOD; ELEMENT ANALYSIS; CERTIFICATION; DISSOLUTION; COBALT; NICKEL; RNAA; NAA; SPECTROMETRY; POSITION AB A very accurate and sensitive method for the simultaneous determination of trace amounts of Co and Ni in biological materials has been elaborated. The method is based on radiochemical neutron activation. Irradiation of samples in Cd-shielded channel of a nuclear reactor assures balanced activity ratio of Co-58 and Co-60 isotopes and favourable detection limits for both nickel and cobalt. Column chromatography (ion exchange and extraction) has been used for the quantitative and selective isolation of the determined radionuclides. High accuracy of the method has been demonstrated by the analysis of several certified reference materials. C1 NIST,GAITHERSBURG,MD 20899. RP PolkowskaMotrenko, H (reprint author), INST NUCL CHEM & TECHNOL,UL DORODNA 16,PL-03195 WARSAW,POLAND. NR 45 TC 13 Z9 13 U1 0 U2 1 PU AKADEMIAI KIADO PI BUDAPEST PA PO BOX 245, H-1519 BUDAPEST, HUNGARY SN 0236-5731 J9 J RADIOAN NUCL CH AR JI J. Radioanal. Nucl. Chem.-Artic. PD JUL PY 1996 VL 207 IS 2 BP 401 EP 412 DI 10.1007/BF02071245 PG 12 WC Chemistry, Analytical; Chemistry, Inorganic & Nuclear; Nuclear Science & Technology SC Chemistry; Nuclear Science & Technology GA VM494 UT WOS:A1996VM49400017 ER PT J AU Cornell, E AF Cornell, E TI Very cold indeed: The nanokelvin physics of Bose-Einstein condensation SO JOURNAL OF RESEARCH OF THE NATIONAL INSTITUTE OF STANDARDS AND TECHNOLOGY LA English DT Article DE atom laser; atom traps; Bose-Einstein condensation; evaporative cooling; superfluids and supergasses AB As atoms get colder, they start to behave more like waves and less like particles. Cool a cloud of identical atoms so cold that the wave of each atom starts to overlap with the wave of its neighbor atom, and all of a sudden you wind up with a sort of quantum identity crisis known as Bose-Einstein condensation. How do we get some thing that cold? And what is the nature of the strange goop that results? These questions were addressed in a colloquium at the National Institute of Standards and Technology in Gaithersburg, Maryland, on February 23, 1996. This paper is an edited transcript of that presentation. C1 UNIV COLORADO, DEPT PHYS, BOULDER, CO 80309 USA. RP Cornell, E (reprint author), NATL INST STAND & TECHNOL, QUANTUM PHYS DIV, PHYS LAB, BOULDER, CO 80309 USA. NR 0 TC 22 Z9 22 U1 0 U2 2 PU US GOVERNMENT PRINTING OFFICE PI WASHINGTON PA SUPERINTENDENT DOCUMENTS,, WASHINGTON, DC 20402-9325 USA SN 1044-677X J9 J RES NATL INST STAN JI J. Res. Natl. Inst. Stand. Technol. PD JUL-AUG PY 1996 VL 101 IS 4 BP 419 EP 434 DI 10.6028/jres.101.045 PG 16 WC Instruments & Instrumentation; Physics, Applied SC Instruments & Instrumentation; Physics GA VX636 UT WOS:A1996VX63600002 PM 27805098 ER PT J AU Proukakis, NP Burnett, K AF Proukakis, NP Burnett, K TI Generalized mean fields for trapped atomic Bose-Einstein condensates SO JOURNAL OF RESEARCH OF THE NATIONAL INSTITUTE OF STANDARDS AND TECHNOLOGY LA English DT Article DE evaporative cooling; Hartree-Fock-Bogoliubov approximation; kinetics of Bose-Einstein condensation; mean-field theory; nonlinear Schrodinger equation ID NONLINEAR SCHRODINGER-EQUATION; NEUTRAL ATOMS; SODIUM ATOMS; GAS; DILUTE AB We describe generalized time-dependent mean-field equations for partially condensed samples of trapped and evaporatively cooled atoms. These equations give a way of investigating the various order parameters that may be present as well as the existence of a mean value of the field due to condensed atoms. Our approach provides us with a closed system of self-consistent equations for the order parameters present. The equations we derive are shown to reduce to other treatments in the literature in various limits. We also show how the equation of motion method allows us to construct a formalism that can handle the evolution of these mean fields due to two-loop kinetics. C1 NIST, GAITHERSBURG, MD 20899 USA. RP Proukakis, NP (reprint author), UNIV OXFORD, DEPT PHYS, CLARENDON LAB, PARKS RD, OXFORD OX1 3PU, ENGLAND. NR 41 TC 64 Z9 64 U1 0 U2 8 PU US GOVERNMENT PRINTING OFFICE PI WASHINGTON PA SUPERINTENDENT DOCUMENTS,, WASHINGTON, DC 20402-9325 USA SN 1044-677X J9 J RES NATL INST STAN JI J. Res. Natl. Inst. Stand. Technol. PD JUL-AUG PY 1996 VL 101 IS 4 BP 457 EP 469 DI 10.6028/jres.101.048 PG 13 WC Instruments & Instrumentation; Physics, Applied SC Instruments & Instrumentation; Physics GA VX636 UT WOS:A1996VX63600005 PM 27805101 ER PT J AU Julienne, PS AF Julienne, PS TI Cold binary atomic collisions in a light field SO JOURNAL OF RESEARCH OF THE NATIONAL INSTITUTE OF STANDARDS AND TECHNOLOGY LA English DT Article DE binary atomic collision; Bose-Einstein Condensation; cold trapped atoms; Franck-Condon factor; photoassociation spectrum; spectral line shape ID BOSE-EINSTEIN CONDENSATION; TEMPERATURE H-DOWN; PHOTOASSOCIATIVE SPECTROSCOPY; SODIUM ATOMS; INTENSITY DEPENDENCE; ULTRACOLD COLLISIONS; OPTICAL SUPPRESSION; NONADIABATIC THEORY; RESONANCE OPTICS; COOLED ATOMS AB The rate coefficients are calculated for trap loss due to excited state formation during s-wave collisions of two atoms in a light field in a cold atomic gas near conditions for formation of a Bose-Einstein condensate. Blue detuning from the allowed atomic resonance transition causes excitation of a replusive molecular potential, whereas red detuning causes excitation when the light is tuned near a bound vibrational energy level of an attractive molecular potential. In either case, when the light intensity is low and the detuning is large compared to the natural linewidth of the atomic transition, the rate coefficient for the collisional loss rate is proportional to a molecular Franck-Condon factor. A simple reflection approximation formula is derived which permits the rate coefficient to be given analytically in either case. The Franck-Condon factor is equal to \Psi(g)(R(C))\(2)/D-C, where Psi(g)(R(C)) is the ground state scattering wavefunction at the Condon point R(C), where the quasimolecule is in resonance with the exciting light, and D-C is the slope difference between ground and excited potentials at R(C). The analytic reflection approximation formula, as well as a simple phase-amplitude formula for the intermediate range wavefunction, give excellent agreement with the results of numerical quantum mechanical calculations. The trap loss rates due to binary collisions are comparable to or exceed those due to atomic recoil heating for a wide range of detunings to the blue of atomic resonance and near the peaks of photoassociation resonances for the case of red detuning. RP Julienne, PS (reprint author), NIST, QUANTUM PROC GRP, ATOM PHYS DIV, PHYS LAB, GAITHERSBURG, MD 20899 USA. RI Julienne, Paul/E-9378-2012 OI Julienne, Paul/0000-0002-5494-1442 NR 50 TC 77 Z9 76 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 JUL-AUG PY 1996 VL 101 IS 4 BP 487 EP 503 DI 10.6028/jres.101.050 PG 17 WC Instruments & Instrumentation; Physics, Applied SC Instruments & Instrumentation; Physics GA VX636 UT WOS:A1996VX63600007 PM 27805103 ER PT J AU Tiesinga, E Williams, CJ Julienne, PS Jones, KM Lett, PD Phillips, WD AF Tiesinga, E Williams, CJ Julienne, PS Jones, KM Lett, PD Phillips, WD TI A spectroscopic determination of scattering lengths for sodium atom collisions SO JOURNAL OF RESEARCH OF THE NATIONAL INSTITUTE OF STANDARDS AND TECHNOLOGY LA English DT Article DE laser cooling; photoassociation spectroscopy; scattering length; spectral line shapes; ultracold sodium atom collisions ID BOSE-EINSTEIN CONDENSATION; ALKALI RESONANCE LINES; PHOTOASSOCIATIVE SPECTROSCOPY; COOLED ATOMS; DISPERSION; EXCHANGE; STATES; GAS AB We report a preliminary value for the zero magnetic field Na S-2(f = 1, m = - 1) + Na S-2(f = 1, m = - 1) scattering length, a(1, - 1). This parameter describes the low-energy elastic two-body processes in a dilute gas of composite bosons and determines, to a large extent, the macroscopic wavefunction of a Bose condensate in a trap. Our scattering length is obtained from photoassociative spectroscopy with samples of uncondensed atoms. The temperature of the atoms is sufficiently low that contributions from the three lowest partial waves dominate the spectrum. The observed lineshapes for the purely long-range O-g(-) molecular state enable us to establish key features of the ground state scattering wavefunction. The fortuitous occurrence of a p-wave node near the deepest point (R(e) = 72 a(0)) of the O-g(-) potential curve is instrumental in determining a(1, - 1) = (52 +/- 5) a(0) and a(2,2) = (85 +/- 3) a(0), where the latter is for a collision of two Na S-2(f = 2, m = 2) atoms. C1 UNIV CHICAGO, JAMES FRANCK INST, CHICAGO, IL 60637 USA. WILLIAMS COLL, WILLIAMSTOWN, MA 01267 USA. RP Tiesinga, E (reprint author), NIST, ATOM PHYS DIV, PHYS LAB, GAITHERSBURG, MD 20899 USA. RI Williams, Carl/B-5877-2009; Julienne, Paul/E-9378-2012 OI Julienne, Paul/0000-0002-5494-1442 NR 32 TC 168 Z9 168 U1 1 U2 6 PU US GOVERNMENT PRINTING OFFICE PI WASHINGTON PA SUPERINTENDENT DOCUMENTS,, WASHINGTON, DC 20402-9325 USA SN 1044-677X J9 J RES NATL INST STAN JI J. Res. Natl. Inst. Stand. Technol. PD JUL-AUG PY 1996 VL 101 IS 4 BP 505 EP 520 DI 10.6028/jres.101.051 PG 16 WC Instruments & Instrumentation; Physics, Applied SC Instruments & Instrumentation; Physics GA VX636 UT WOS:A1996VX63600008 PM 27805104 ER PT J AU Mies, FH Williams, CJ Julienne, PS Krauss, M AF Mies, FH Williams, CJ Julienne, PS Krauss, M TI Estimating bounds on collisional relaxation rates of spin-polarized Rb-87 atoms at ultracold temperatures SO JOURNAL OF RESEARCH OF THE NATIONAL INSTITUTE OF STANDARDS AND TECHNOLOGY LA English DT Article DE ab initio calculations; cold trapped atoms; rubidium atom collisions; second-order spin-orbit; spin-relaxation rate; spin-spin interactions ID BOSE-EINSTEIN CONDENSATION; SCATTERING; HYDROGEN; PREDISSOCIATION; MOLECULES; ENERGY; STATES; HALF; GAS AB We present quantum scattering calculations for the collisional relaxation rate coefficient of spin-polarized Rb-87(f = 2, m = 2) atoms, which determines the loss rate of cold Rb atoms from a magnetic trap. Unlike the lighter alkali atoms, spin-polarized Rb-87 atoms can undergo dipolar relaxation due to both the normal spin-spin dipole interaction and a second-order spinorbit interaction with distant electronic states of the dimer. We present ab initio calculations for the second-order spin-orbit terms for both Rb-2 and Cs-2. The corrections lead to a reduction in the relaxation rate for Rb-87. Our primary concern is to analyze the sensitivity of the Rb-87 trap loss to the uncertainties in the ground state molecular potentials. Since the scattering length for the a(3) Sigma(u)(+), state is already known, the major uncertainties are associated with the X(1) Sigma(g)(+), potential. After testing the effect of systematically modifying the short-range form of the molecular potentials over a reasonable range, and introducing our best estimate of the second-order spin-orbit interaction, we estimate that in the low temperature limit the rare coefficient for loss of Rb atoms from the f = 2,m = 2 state is between 0.4 x 10(-15) cm(3)/s and 2.4 x 10(-15) cm(3)/s (where this number counts two atoms lost per collision). In a pure condensate the rate coefficient would be reduced by 1/2. RP Mies, FH (reprint author), NIST, GAITHERSBURG, MD 20899 USA. RI Williams, Carl/B-5877-2009; Julienne, Paul/E-9378-2012 OI Julienne, Paul/0000-0002-5494-1442 NR 31 TC 88 Z9 88 U1 1 U2 9 PU US GOVERNMENT PRINTING OFFICE PI WASHINGTON PA SUPERINTENDENT DOCUMENTS,, WASHINGTON, DC 20402-9325 USA SN 1044-677X J9 J RES NATL INST STAN JI J. Res. Natl. Inst. Stand. Technol. PD JUL-AUG PY 1996 VL 101 IS 4 BP 521 EP 535 DI 10.6028/jres.101.052 PG 15 WC Instruments & Instrumentation; Physics, Applied SC Instruments & Instrumentation; Physics GA VX636 UT WOS:A1996VX63600009 PM 27805105 ER PT J AU Dodd, RJ AF Dodd, RJ TI Approximate solutions of the nonlinear Schrodinger equation for ground and excited states of Bose-Einstein condensates SO JOURNAL OF RESEARCH OF THE NATIONAL INSTITUTE OF STANDARDS AND TECHNOLOGY LA English DT Article DE Bose-Einstein condensation; Ginzburg-Pitaevskii-Gross energy functional; Gross-Pitaevskii equation; mean-field theory; superfluidity; Thomas-Fermi functional model; time-independent nonlinear Schrodinger equation; variational wave function; vortex formation ID TRAPPED NEUTRAL ATOMS; GAS AB I present simple analytical methods for computing the properties of ground and excited states of Bose-Einstein condensates, and compare their results to extensive numerical simulations. I consider the effect of vortices in the condensate for both positive and negative scattering lengths, a, and find an analytical expression for the large-N-0 limit of the vortex critical frequency for a > 0, by approximate solution of the time-independent nonlinear Schrodinger equation. C1 UNIV MARYLAND, INST PHYS SCI & TECHNOL, COLLEGE PK, MD 20742 USA. RP Dodd, RJ (reprint author), NIST, ELECTRON & OPT PHYS DIV, PHYS LAB, GAITHERSBURG, MD 20899 USA. NR 28 TC 50 Z9 51 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 JUL-AUG PY 1996 VL 101 IS 4 BP 545 EP 552 DI 10.6028/jres.101.054 PG 8 WC Instruments & Instrumentation; Physics, Applied SC Instruments & Instrumentation; Physics GA VX636 UT WOS:A1996VX63600011 PM 27805107 ER PT J AU Edwards, M Dodd, RJ Clark, CW Burnett, K AF Edwards, M Dodd, RJ Clark, CW Burnett, K TI Zero-temperature, mean-field theory of atomic Bose-Einstein condensates SO JOURNAL OF RESEARCH OF THE NATIONAL INSTITUTE OF STANDARDS AND TECHNOLOGY LA English DT Article DE Bogoliubov equations; Bose-Einstein condensation; Gross-Pitaevskii equation; linear excitations; mean-field theory; nonlinear Schrodinger equation; superfluidity; vortex formation ID NONLINEAR SCHRODINGER-EQUATION; TRAPPED NEUTRAL ATOMS; GAS AB We review the application of zero-temperature, mean-field theory to current experimental atomic Bose-Einstein condensates. We assess the validity of the approximations made by comparing the mean-field results with a variety of experimental data. C1 NATL INST STAND & TECHNOL, GAITHERSBURG, MD 20899 USA. UNIV OXFORD, DEPT PHYS, CLARENDON LAB, OXFORD OX1 3PU, ENGLAND. RP Edwards, M (reprint author), GEORGIA SO COLL, DEPT PHYS, STATESBORO, GA 30460 USA. RI Clark, Charles/A-8594-2009 OI Clark, Charles/0000-0001-8724-9885 NR 38 TC 58 Z9 58 U1 0 U2 4 PU US GOVERNMENT PRINTING OFFICE PI WASHINGTON PA SUPERINTENDENT DOCUMENTS,, WASHINGTON, DC 20402-9325 USA SN 1044-677X J9 J RES NATL INST STAN JI J. Res. Natl. Inst. Stand. Technol. PD JUL-AUG PY 1996 VL 101 IS 4 BP 553 EP 565 DI 10.6028/jres.101.055 PG 13 WC Instruments & Instrumentation; Physics, Applied SC Instruments & Instrumentation; Physics GA VX636 UT WOS:A1996VX63600012 PM 27805108 ER PT J AU Barnett, SM Burnett, K Vaccaro, JA AF Barnett, SM Burnett, K Vaccaro, JA TI Why a condensate can be thought of as having a definite phase SO JOURNAL OF RESEARCH OF THE NATIONAL INSTITUTE OF STANDARDS AND TECHNOLOGY LA English DT Article DE Bose-Einstein condensate; broken symmetry; coherent state; open quantum system; phase ID QUANTUM; MECHANICS; SYMMETRY AB We present an argument for assigning a definite phase to an assembly of Bose-Einstein Condensed atoms. This relies on the demonstration that a coherent state of the condensed system is a robust state in the presence of interactions between the condensate and its environment. C1 UNIV OXFORD, DEPT PHYS, CLARENDON LAB, OXFORD OX1 3PU, ENGLAND. NIST, GAITHERSBURG, MD 20899 USA. OPEN UNIV, DEPT PHYS, MILTON KEYNES MK7 6AA, BUCKS, ENGLAND. RP Barnett, SM (reprint author), UNIV STRATHCLYDE, DEPT PHYS & APPL PHYS, GLASGOW G4 0NG, LANARK, SCOTLAND. RI Vaccaro, Joan/B-9634-2008 OI Vaccaro, Joan/0000-0003-4576-9545 NR 23 TC 55 Z9 55 U1 0 U2 3 PU US GOVERNMENT PRINTING OFFICE PI WASHINGTON PA SUPERINTENDENT DOCUMENTS,, WASHINGTON, DC 20402-9325 USA SN 1044-677X J9 J RES NATL INST STAN JI J. Res. Natl. Inst. Stand. Technol. PD JUL-AUG PY 1996 VL 101 IS 4 BP 593 EP 600 DI 10.6028/jres.101.059 PG 8 WC Instruments & Instrumentation; Physics, Applied SC Instruments & Instrumentation; Physics GA VX636 UT WOS:A1996VX63600016 PM 27805112 ER PT J AU Tewary, VK Fortunko, CM AF Tewary, VK Fortunko, CM TI Surface waves in three-dimensional half-space tetragonal solids SO JOURNAL OF THE ACOUSTICAL SOCIETY OF AMERICA LA English DT Article AB The delta-function representation of the elastodynamic Green's function is applied to calculate the three-dimensional waveforms for elastic-pulse propagation at the free surface in a half-space tetragonal solid. RP Tewary, VK (reprint author), NATL INST STAND & TECHNOL,DIV MAT RELIABIL,325 BROADWAY,BOULDER,CO 80303, USA. NR 10 TC 9 Z9 9 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 JUL PY 1996 VL 100 IS 1 BP 86 EP 88 DI 10.1121/1.415945 PG 3 WC Acoustics; Audiology & Speech-Language Pathology SC Acoustics; Audiology & Speech-Language Pathology GA UW514 UT WOS:A1996UW51400008 ER PT J AU Tewary, VK Fortunko, CM AF Tewary, VK Fortunko, CM TI Lattice correction to mechanical admittance of solids SO JOURNAL OF THE ACOUSTICAL SOCIETY OF AMERICA LA English DT Article AB The singularity in the imaginary part of the point mechanical admittance of a solid, as predicted by the continuum model, can be removed by taking into account the discrete structure of the lattice. As an example, a new nonsingular expression for the point mechanical admittance of a solid is derived for scalar waves by using the Debye model Green's function, which incorporates the lattice effects by restricting the wave vector to the first Brillouin zone of the solid. RP Tewary, VK (reprint author), NATL INST STAND & TECHNOL,325 BROADWAY,BOULDER,CO 80303, USA. NR 6 TC 2 Z9 2 U1 0 U2 2 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 JUL PY 1996 VL 100 IS 1 BP 89 EP 91 DI 10.1121/1.415946 PG 3 WC Acoustics; Audiology & Speech-Language Pathology SC Acoustics; Audiology & Speech-Language Pathology GA UW514 UT WOS:A1996UW51400009 ER PT J AU Johnson, W Auld, BA Segal, E Passarelli, F AF Johnson, W Auld, BA Segal, E Passarelli, F TI Trapped torsional modes in solid cylinders SO JOURNAL OF THE ACOUSTICAL SOCIETY OF AMERICA LA English DT Article AB An approximate theory is presented for torsional modes in a solid cylinder having a larger-diameter central section. Modes in a narrow frequency range just above the cutoff of each branch are ''trapped'' such that, in long samples, the amplitudes decay exponentially with distance from the central section. To confirm the theory, measurements were performed on aluminum alloy cylinders using noncontacting electromagnetic-acoustic transduction. Vibrational amplitudes of a trapped mode measured as a function of position along the length of a sample are in good agreement with theoretical calculations. The resonant frequencies of three samples with different dimensions also closely match the theory for trapped modes. Additional generally weak resonances that are observed may be associated with torsional modes that vary sinusoidally along the entire length of the samples. C1 SONIMETRIX,COVINA,CA 91722. RP Johnson, W (reprint author), NATL INST STAND & TECHNOL,DIV MAT RELIABIL,325 BROADWAY,BOULDER,CO 80303, USA. NR 21 TC 20 Z9 20 U1 0 U2 3 PU AMER INST PHYSICS PI WOODBURY PA CIRCULATION FULFILLMENT DIV, 500 SUNNYSIDE BLVD, WOODBURY, NY 11797-2999 SN 0001-4966 J9 J ACOUST SOC AM JI J. Acoust. Soc. Am. PD JUL PY 1996 VL 100 IS 1 BP 285 EP 293 DI 10.1121/1.415955 PG 9 WC Acoustics; Audiology & Speech-Language Pathology SC Acoustics; Audiology & Speech-Language Pathology GA UW514 UT WOS:A1996UW51400030 ER PT J AU Pajares, A Wei, LH Lawn, BR Berndt, CC AF Pajares, A Wei, LH Lawn, BR Berndt, CC TI Contact damage in plasma-sprayed alumina-based coatings SO JOURNAL OF THE AMERICAN CERAMIC SOCIETY LA English DT Article ID HETEROGENEOUS GRAIN-STRUCTURE; HERTZIAN CONTACTS; POLYCRYSTALLINE CERAMICS; INDENTATION FRACTURE; SILICON-CARBIDE; CYCLIC FATIGUE; ACCUMULATION AB A study of Hertzian contact damage in plasma-sprayed alumina-based ceramic coatings on steel substrates has been made. Presectioned specimens are used to identify subsurface micromechanical damage processes within the coating and substrate layers as a function of increasing contact load, from both postcontact and in situ observations, Damage occurs principally by cracking in the ceramic coating and plastic deformation in the metal substrate, along with delamination at the coating/substrate interface. Coating thickness, cycling loading (fatigue), and processing history (coating microstructure) are shown to be important factors in the damage patterns and ensuing modes of failure, Indentation stress-strain curves are used to measure macroscopic mechanical responses, to quantify the maximum sustainable contact stresses and to determine the relative roles of coating and substrate in the net deformation. C1 SUNY STONY BROOK, DEPT MAT SCI & ENGN, STONY BROOK, NY 11794 USA. RP NIST, MAT SCI & ENGN LAB, GAITHERSBURG, MD 20899 USA. RI Pajares, Antonia/I-3881-2015 OI Pajares, Antonia/0000-0002-1086-7586 NR 29 TC 50 Z9 50 U1 0 U2 6 PU WILEY-BLACKWELL PI HOBOKEN PA 111 RIVER ST, HOBOKEN 07030-5774, NJ USA SN 0002-7820 EI 1551-2916 J9 J AM CERAM SOC JI J. Am. Ceram. Soc. PD JUL PY 1996 VL 79 IS 7 BP 1907 EP 1914 DI 10.1111/j.1151-2916.1996.tb08012.x PG 8 WC Materials Science, Ceramics SC Materials Science GA UY841 UT WOS:A1996UY84100023 ER PT J AU Hill, MD White, GS Hwang, CS Lloyd, IK AF Hill, MD White, GS Hwang, CS Lloyd, IK TI Cyclic damage in lead zirconate titanate SO JOURNAL OF THE AMERICAN CERAMIC SOCIETY LA English DT Article ID CERAMICS AB The effect of mechanical cycling (four-point bending),and electrical cycling (ac excitation at the longitudinal resonance frequency) on the degradation of the mechanical properties of PZT-8 bars was examined, Transmission electron microscopy (TEM) revealed microcracks which originated from second-phase material located at triple junctions, Energy-dispersive spectroscopy (EDS) showed that this second-phase material contained Pb, Ti, and Fe, but no detectable Zr. High intergranular microcrack densities were observed for mechanically cycled samples and samples electrically cycled at temperatures less than or equal to 80 degrees C. Electrically cycled samples allowed to heat to a steady-state temperature of 180 degrees C showed much lower crack densities. Piezoelectric coefficient (d(33)) measurements revealed that depolarization occurs in the 180 degrees C electrically cycled samples, but not in mechanically cycled materials nor in the 80 degrees C electrically cycled material, Also, samples heated in a furnace to 180 degrees C in the absence of external stress showed no evidence of depolarization. It appears that elevated temperatures (approximate to 180 degrees C) are necessary to cause depolarization in PZT-8 at the resonance-induced stresses used in this work. C1 UNIV MARYLAND,COLLEGE PK,MD 20742. RP Hill, MD (reprint author), NIST,DIV CERAM,GAITHERSBURG,MD 20899, USA. RI Lloyd, Isabel/B-1513-2012; Hwang, Cheol Seong/C-8568-2009 NR 15 TC 65 Z9 70 U1 0 U2 9 PU AMER CERAMIC SOC PI WESTERVILLE PA 735 CERAMIC PLACE, PO BOX 6136, WESTERVILLE, OH 43081-6136 SN 0002-7820 J9 J AM CERAM SOC JI J. Am. Ceram. Soc. PD JUL PY 1996 VL 79 IS 7 BP 1915 EP 1920 DI 10.1111/j.1151-2916.1996.tb08013.x PG 6 WC Materials Science, Ceramics SC Materials Science GA UY841 UT WOS:A1996UY84100024 ER PT J AU Black, ML Burpee, RW Marks, FD AF Black, ML Burpee, RW Marks, FD TI Vertical motion characteristics of tropical cyclones determined with airborne Doppler radial velocities SO JOURNAL OF THE ATMOSPHERIC SCIENCES LA English DT Article ID CONVECTIVE-SCALE CHARACTERISTICS; HURRICANE ALLEN 1980; INNER CORE STRUCTURE; OCEANIC CONVECTION; RADAR OBSERVATIONS; MATURE HURRICANES; AIR MOTIONS; SQUALL LINE; MESOSCALE; EVOLUTION AB Vertical motions in seven Atlantic hurricanes are determined from data recorded by Doppler radars on research aircraft. The database consists of Doppler velocities and reflectivities from vertically pointing radar rays collected along radial flight legs through the hurricane centers. The vertical motions are estimated throughout the depth of the troposphere from the Doppler velocities and bulk estimates of particle fallspeeds. Portions of the flight tracks are subjectively divided into eyewall, rainband, stratiform, and ''other'' regions. Characteristics of the vertical velocity and radar structure are described as a function of altitude for the entire dataset and each of the four regions. Tn all of the regions, more than 70% of the vertical velocities range from -2 to 2 m s(-1). The broadest distribution of vertical motion is in the eyewall region where similar to 5% of the vertical motions are >5 m s(-1). Averaged over the entire dataset, the mean vertical velocity is upward at altitudes. Mean downward motion occurs only in the lower troposphere of the stratiform region. Significant vertical variations in the mean profiles of vertical velocity and reflectivity are discussed and related to microphysical processes. In the lower and middle troposphere, the characteristics of the Doppler-derived vertical motions are similar to those described in an earlier study using flight-level vertical velocities, even though the horizontal resolution of the Doppler data is similar to 750 m compared to similar to 125 m from the in situ flight-level measurements. The Doppler data are available at higher altitudes than those reached by turboprop aircraft and provide information oil vertical as well as horizontal variations. In a vertical plane along the radial flight tracks, Doppler up- and downdrafts are defined at each 300-m altitude interval as vertical Velocities whose absolute Values continuously exceed 1.5 m s(-1), with at least one speed having an absolute value greater than 3.0 m s(-1). The properties of the Doppler drafts are lognormally distributed. In each of the regions, updrafts outnumber downdrafts by at least a factor of 2 and updrafts are wider and stronger than downdrafts. Updrafts in the eyewall slope radially outward with height and are significantly correlated over larger radial and vertical extents than in the other three regions. If the downwind (tangential) slope with height of updrafts varies little among the regions, updrafts capable of transporting air with relatively large moist static energy from the boundary layer to the upper troposphere are primarily in the eyewall region. Downdrafts affect a smaller vertical and horizontal area than updrafts and have no apparent radial slope. The total upward or downward mass flux is defined as the flux produced by all of the upward or downward Doppler vertical velocities. The maximum upward mass flux in all but the ''other'' region is near 1-km altitude, an indication that boundary-layer convergence is efficient in producing upward motion. Above the sea surface, the downward mass flux decreases with altitude. At every altitude, the total net mass flux is upward, except for the lower troposphere in the stratiform region where it is downward. Doppler-derived up- and downdrafts are a subset of the vertical velocity field that occupy small fractions of the total area, yet they contribute a substantial fraction to the total mass flux, In the eyewall and rainband regions, for example, the Doppler updrafts cover less than 30% of the area but are responsible for >75% and >50% to the total upward mass flux, respectively. The Doppler downdrafts typically encompass less than 10% of the area yet provide similar to 50% of the total downward mass flux in the eyewall and similar to 20% of the total downward Aux in the rainband, stratiform, and ''other'' regions. RP Black, ML (reprint author), NOAA,ATLANTIC OCEANOG & METEOROL LAB,HURRICANE RES DIV,4301 RICKENBACKER CAUSEWAY,MIAMI,FL 33149, USA. RI Marks, Frank/A-5733-2011; Black, Michael/C-3250-2014 OI Marks, Frank/0000-0003-0371-5514; Black, Michael/0000-0001-9528-2888 NR 44 TC 106 Z9 110 U1 0 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 JUL 1 PY 1996 VL 53 IS 13 BP 1887 EP 1909 DI 10.1175/1520-0469(1996)053<1887:VMCOTC>2.0.CO;2 PG 23 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA UZ829 UT WOS:A1996UZ82900008 ER PT J AU Waytena, GL Hoff, HA Ma, DI Isaacson, IP Rebbert, ML Marrian, C Suehle, JS AF Waytena, GL Hoff, HA Ma, DI Isaacson, IP Rebbert, ML Marrian, C Suehle, JS TI The use of a double mask system to prevent Ti diffusion from a Ti/Pt/Au ohmic contact on diamond SO JOURNAL OF THE ELECTROCHEMICAL SOCIETY LA English DT Article ID SCHOTTKY AB Ohmic contacts on diamond were fabricated using a Ti/Pt/Au metallization scheme and two transmission line model masks. The double mask system is used to isolate the Ti by surrounding it with Pt. Pt is expected to prevent Ti diffusion either to the contact surface or along the diamond surface during annealing. In this study we found that this system of masks was successful in preventing the Ti diffusion as revealed by Auger analysis on the diamond and contact surfaces. An Auger depth profile revealed that the Ti was confined to the diamond/contact interfacial region, and was most likely combined with Pt. C1 USN, RES LAB, NANOELECT PROC FACIL, WASHINGTON, DC 20375 USA. NIST, GAITHERSBURG, MD 20899 USA. RP Waytena, GL (reprint author), USN, RES LAB, WASHINGTON, DC 20375 USA. NR 9 TC 12 Z9 12 U1 0 U2 0 PU ELECTROCHEMICAL SOC INC PI PENNINGTON PA 65 SOUTH MAIN STREET, PENNINGTON, NJ 08534 USA SN 0013-4651 J9 J ELECTROCHEM SOC JI J. Electrochem. Soc. PD JUL PY 1996 VL 143 IS 7 BP 2392 EP 2395 DI 10.1149/1.1837013 PG 4 WC Electrochemistry; Materials Science, Coatings & Films SC Electrochemistry; Materials Science GA UY445 UT WOS:A1996UY44500062 ER PT J AU Marquardt, JH Robinson, HG Hollberg, L AF Marquardt, JH Robinson, HG Hollberg, L TI Line shapes of cascade two-photon transitions in a cesium magneto-optic trap SO JOURNAL OF THE OPTICAL SOCIETY OF AMERICA B-OPTICAL PHYSICS LA English DT Article ID QUANTIZED MOTION; ATOMS; RESONANCE; MOLASSES AB We present a study of a two-photon double-resonance transition in cold cesium atoms in a magneto-optic trap. A closed five-level density matrix model of the system is developed to characterize the double-resonance Autler-Townes-split absorption line shape. Comparing this model with experimental spectra, we gain insight into the dominant process involved in trapping atoms, in particular, the importance of the interference of the six trapping laser beams. This system is used to probe transient effects in the trap as well as collective effects of the trapped atom cloud resulting from the intentional misalignment of the trapping beams. RP Marquardt, JH (reprint author), NATL INST STAND & TECHNOL,BOULDER,CO 80303, USA. NR 20 TC 13 Z9 13 U1 0 U2 2 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 JUL PY 1996 VL 13 IS 7 BP 1384 EP 1393 DI 10.1364/JOSAB.13.001384 PG 10 WC Optics SC Optics GA UY475 UT WOS:A1996UY47500007 ER PT J AU Childs, KD Narum, D LaVanier, LA Lindley, PM Schueler, BW Mulholland, G Diebold, AC AF Childs, KD Narum, D LaVanier, LA Lindley, PM Schueler, BW Mulholland, G Diebold, AC TI Comparison of submicron particle analysis by Auger electron spectroscopy, time-of-flight secondary ion mass spectrometry, and secondary electron microscopy with energy dispersive x-ray spectroscopy SO JOURNAL OF VACUUM SCIENCE & TECHNOLOGY A-VACUUM SURFACES AND FILMS LA English DT Article ID SPATIAL-RESOLUTION AB Particulate contamination can result in a significant yield loss during semiconductor device fabrication. As device design rule dimensions decrease the critical defect size also decreases, resulting in the need to analyze smaller defects. Current manufacturing requirements include analysis of sub-0.5-mu m defects, with analysis of sub-0.1-mu m defects expected in the near future. This article investigates the particle analysis capabilities of Auger electron spectroscopy, time-of-flight secondary ion mass spectrometry, and energy dispersive x-ray spectroscopy during scanning electron microscopy (SEM/EDS). In order to evaluate each method carefully, a standard set of samples was prepared and analyzed. These samples consist of 0.5-, 0.3-, and 0.1-mu m Al and Al2O3 deposited on 1-in. Si wafers. Although all the methods observed an Al signal, a semiquantitative gauge of capability based on the relative strengths of particle versus substrate signal is provided. The dependence of the sample-to-substrate signal on primary electron energy is examined for both EDS and Auger analyses. The ability to distinguish metallic Al particles from Al oxide particles for the three techniques is also discussed. (C) 1996 American Vacuum Society. C1 CHARLES EVANS & ASSOCIATES,REDWOOD CITY,CA 94063. PHYS ELECTR INC,REDWOOD CITY,CA 94063. NIST,GAITHERSBURG,MD 20899. SEMATECH,AUSTIN,TX 78741. RP Childs, KD (reprint author), PHYS ELECTR INC,6509 FLYING CLOUD DR,EDEN PRAIRIE,MN 55344, USA. NR 9 TC 21 Z9 21 U1 0 U2 2 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 JUL-AUG PY 1996 VL 14 IS 4 BP 2392 EP 2404 DI 10.1116/1.580027 PG 13 WC Materials Science, Coatings & Films; Physics, Applied SC Materials Science; Physics GA VA964 UT WOS:A1996VA96400061 ER PT J AU Tison, SA AF Tison, SA TI A critical evaluation of thermal mass flow meters SO JOURNAL OF VACUUM SCIENCE & TECHNOLOGY A-VACUUM SURFACES AND FILMS LA English DT Article AB Many semiconductor processes require that stable and known flows of gas be delivered to the processing chamber. The thermal mass flow meter (TMFM) is used almost exclusively in the semiconductor industry for the admission of process gases. While TMFM's have been used in the semiconductor industry for over twenty years, much still remains to be understood about their behavior. The abundance of TMFM manufacturers that make instruments which are supposedly interchangeable complicates the use of TMFM's because the instruments generally have different designs and performance. While some attempt has been made via written standards to address the specifications of the instruments, these standards do not address all performance issues and cannot eliminate the systematic errors in the original manufacturers calibration of the TMFM's. Further, the TMFM's used to measure the process gases are generally calibrated with nitrogen and ''corrected'' for other gases, but the correction factors are not well understood and are of questionable reliability. It is also important to understand how the TMFM's perform under conditions that differ from the laboratory conditions where they were calibrated and the measurement errors that are introduced as a result of these different operating conditions. This article presents data on the performance of five low-flow TMFM's, from different manufacturers, with full scale ranges of 1.5 x 10(-6) -3.7 x 10(-6) mol/s (2-5 seem). The manufacturers' calibration of the TMFM's with nitrogen as compared to the National Institute of Standards and Technology (NIST) measured values differed by up to 17%. Three of the five tested TMFM's were within the manufacturers' stated tolerance of +/-1% of full scale. While some of the instruments' initial calibration was poor, all of the TMFM's were stable to within +/-1% of full scale over the test interval of nine months. The gas correction factors for five gases (argon, helium, hydrogen, sulfur hexafluoride, and hexafluoroethane) were measured and compared to manufacturers' recommended values along with the temperature and flow dependence of the gas correction factors. Some of the gas correction factors agreed with the manufacturers' recommended values to within +/-1% while others differed by as much as 13%. RP Tison, SA (reprint author), NIST,GAITHERSBURG,MD 20899, USA. NR 7 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 0734-2101 J9 J VAC SCI TECHNOL A JI J. Vac. Sci. Technol. A-Vac. Surf. Films PD JUL-AUG PY 1996 VL 14 IS 4 BP 2582 EP 2591 DI 10.1116/1.579985 PG 10 WC Materials Science, Coatings & Films; Physics, Applied SC Materials Science; Physics GA VA964 UT WOS:A1996VA96400092 ER PT J AU Lorincik, J Marton, D King, RL Fine, J AF Lorincik, J Marton, D King, RL Fine, J TI Scanning scattering microscope for surface microtopography and defect imaging SO JOURNAL OF VACUUM SCIENCE & TECHNOLOGY B LA English DT Article AB A recently developed optical-scatter instrument, the scanning scattering microscope (SSM) produces two-dimensional images of very small surface features and of variations in surface topography. In its present configuration, the lateral resolution is better than 10 mu m and its sensitivity to surface roughness is in the angstrom (rms) range. The performance of the SSM has been demonstrated using calibration gratings, Si(100) surfaces, and Ge thin films grown on silicon; intercomparison also was made with atomic force microscope measurements. These results indicate that this scanned optical technique is a very useful noncontact method for evaluating surface microtopography. C1 ACAD SCI CZECH REPUBL,J HEYROVSKY INST PHYS CHEM,PRAGUE,CZECH REPUBLIC. UNIV HOUSTON,DEPT CHEM,HOUSTON,TX. RP Lorincik, J (reprint author), NATL INST STAND & TECHNOL,SURFACE & MICROANAL SCI DIV,GAITHERSBURG,MD 20899, USA. RI Marton, Denes/E-7759-2010; Lorincik, Jan/F-9054-2014 OI Lorincik, Jan/0000-0003-4227-1514 NR 14 TC 9 Z9 9 U1 0 U2 1 PU AMER INST PHYSICS PI WOODBURY PA CIRCULATION FULFILLMENT DIV, 500 SUNNYSIDE BLVD, WOODBURY, NY 11797-2999 SN 1071-1023 J9 J VAC SCI TECHNOL B JI J. Vac. Sci. Technol. B PD JUL-AUG PY 1996 VL 14 IS 4 BP 2417 EP 2423 DI 10.1116/1.588871 PG 7 WC Engineering, Electrical & Electronic; Nanoscience & Nanotechnology; Physics, Applied SC Engineering; Science & Technology - Other Topics; Physics GA VD931 UT WOS:A1996VD93100004 ER PT J AU Ott, AK Casey, SM Alstrin, AL Leone, SR AF Ott, AK Casey, SM Alstrin, AL Leone, SR TI Chemistry of arsenic incorporation during GaAs/GaAs(100) molecular beam epitaxy probed by simultaneous laser flux monitoring and reflection high-energy electron diffraction SO JOURNAL OF VACUUM SCIENCE & TECHNOLOGY B LA English DT Article ID SCANNING-TUNNELING-MICROSCOPY; 100 GAAS SURFACES; INTERACTION KINETICS; MASS-SPECTROMETRY; MBE GROWTH; INTENSITY OSCILLATIONS; RHEED INTENSITY; MONTE-CARLO; GAAS(001); AS2 AB Arsenic incorporation during GaAs/GaAs(100) molecular beam epitaxy is studied in situ with laser single-photon ionization time-of-flight mass spectrometry and reflection high-energy electron diffraction (RHEED). Incident and scattered fluxes of Ga and As, species in front of the growing GaAs wafer are ionized repetitively by a pulsed laser beam of 118 nm (10.5 eV) photons. The methods to obtain and interpret time-of-flight mass spectra and the simultaneous RHEED measurements are described. The real time behaviors of incident Ga and desorbing As-2 and As-4, obtained without mass spectral cracking, are studied during growth of GaAs layers with AS(4) and when growth is arrested as a function of substrate temperature and Ga/As-4 flux ratio. During growth only with AS(4), both As-2 and As-4 are desorbed or scattered in varying amounts depending on flux and substrate temperature conditions. Without an incident gallium flux, desorbing AS(4) decreases while desorbing AS(2) increases with increasing surface temperature. During gallium deposition and GaAs growth, the amounts of desorbing arsenic fluxes decrease linearly with increasing Ga/As-4 flux ratio, but the arsenic incorporation rate saturates at a Ga/As-4 flux ratio greater than or equal to 2, i.e. (Ga/As greater than or equal to 1/2). The total integrated incorporation of arsenic increases linearly with increasing Ga/AS(4) flux ratio when the surface is allowed to recover with an incident arsenic flux after the gallium flux is terminated. In the range of substrate temperatures optimum for layer-by-layer GaAs growth with As-4, As-4 incorporation dominates at low temperatures, while As-4 and As-2 incorporations contribute equally at high temperatures. Surface reaction sequences and mechanisms of arsenic incorporation are discussed and compared with measured RHEED results and previous experimental and theoretical results. (C) 1996 American Vacuum Society. C1 UNIV COLORADO,DEPT CHEM & BIOCHEM,BOULDER,CO 80309. RP Ott, AK (reprint author), NATL INST STAND & TECHNOL,JOINT INST LAB ASTROPHYS,BOULDER,CO 80309, USA. NR 42 TC 14 Z9 14 U1 2 U2 3 PU AMER INST PHYSICS PI WOODBURY PA CIRCULATION FULFILLMENT DIV, 500 SUNNYSIDE BLVD, WOODBURY, NY 11797-2999 SN 1071-1023 J9 J VAC SCI TECHNOL B JI J. Vac. Sci. Technol. B PD JUL-AUG PY 1996 VL 14 IS 4 BP 2742 EP 2752 DI 10.1116/1.589013 PG 11 WC Engineering, Electrical & Electronic; Nanoscience & Nanotechnology; Physics, Applied SC Engineering; Science & Technology - Other Topics; Physics GA VD931 UT WOS:A1996VD93100051 ER PT J AU Hankin, S Harrison, DE Osborne, J Davison, J OBrien, K AF Hankin, S Harrison, DE Osborne, J Davison, J OBrien, K TI A strategy and a tool, ferret, for closely integrated visualization and analysis SO JOURNAL OF VISUALIZATION AND COMPUTER ANIMATION LA English DT Article; Proceedings Paper CT Workshop on Computer Graphics Technology for the Exploration of the Sea (CES 95) CY MAY, 1995 CL ROSTOCK, GERMANY SP Fraunhofer Inst Comp Graph, German Comp Soc DE oceanography; meteorology; climate; gridded; scientific visualization; mathematical analysis AB Ferret is a workstation-based visualization and analysis environment designed to meet the needs of physical scientists studying global ocean/climate interactions. The scientist working with Ferret is provided with a highly-automated, flexible, end-to-end environment in which he/she can probe large and complex gridded data sets, such as model outputs and observational data products, with little or no assistance from computer professionals. The design of Ferret has emphasized close integration of graphics, analysis, and data management. Ferret provides well-proven scientific graphics styles, such as contours, scatter plots, and vector diagrams, and the ability to define new variables as mathematical expressions involving database variables. Analysis is augmented by regridding capabilities and Boolean operators to perform calculations over arbitrary regions. Ferret's data management is based on a simple, adaptable data model integrated with standardized, self-describing, direct-access files. C1 NOAA,PACIFIC MARINE ENVIRONM LAB,SEATTLE,WA 98115. WASHINGTON UNIV,JOINT INST STUDY ATMOSPHERE & OCEANS,SEATTLE,WA. RI Harrison, Don/D-9582-2013 NR 8 TC 10 Z9 10 U1 0 U2 1 PU JOHN WILEY & SONS LTD PI W SUSSEX PA BAFFINS LANE CHICHESTER, W SUSSEX, ENGLAND PO19 1UD SN 1049-8907 J9 J VISUAL COMP ANIMAT JI J. Vis. Comput. Animat. PD JUL-SEP PY 1996 VL 7 IS 3 BP 149 EP 157 DI 10.1002/(SICI)1099-1778(199607)7:3<149::AID-VIS148>3.0.CO;2-X PG 13 WC Computer Science, Software Engineering SC Computer Science GA VB904 UT WOS:A1996VB90400004 ER PT J AU Poet, SE Skilling, DE Megyesi, JL Gilmartin, WG Smith, AW AF Poet, SE Skilling, DE Megyesi, JL Gilmartin, WG Smith, AW TI Detection of a non-cultivatable calicivirus from the white tern (Gygis alba rothschildi) SO JOURNAL OF WILDLIFE DISEASES LA English DT Article DE calicivirus; white tern; Gygis alba; cDNA hybridization ID VIRUS; STORY; SEALS; WHALE; OCEAN AB In April 1992, on Tern Island, French Frigate Shoals, Hawaii (USA), researchers observed a hand-reared white tern hatchling (Gygis alba rothschildi) develop vesicular lesions on the webbing between its toes, 6 days after falling out of its nest. Vesicular fluid collected from the foot lesions contained virus-like particles having typical calicivirus morphology. Calicivirus RNA was detected in the vesicular fluid by dot hybridization with a group-specific calicivirus copy DNA probe. Attempts to cultivate the virus in African green monkey kidney cells and porcine kidney cells were unsuccessful. This is the first report of a calicivirus infection associated with vesicular disease in a wild avian species. C1 OREGON STATE UNIV,COLL VET MED,CORVALLIS,OR 97331. NATL MARINE FISHERIES SERV,HONOLULU,HI 96822. FISH & WILDLIFE SERV,HONOLULU,HI 96850. NR 35 TC 10 Z9 10 U1 0 U2 1 PU WILDLIFE DISEASE ASSN, INC PI LAWRENCE PA 810 EAST 10TH ST, LAWRENCE, KS 66044-8897 SN 0090-3558 J9 J WILDLIFE DIS JI J. Wildl. Dis. PD JUL PY 1996 VL 32 IS 3 BP 461 EP 467 PG 7 WC Veterinary Sciences SC Veterinary Sciences GA UX347 UT WOS:A1996UX34700007 PM 8827672 ER PT J AU Mortsch, LD Quinn, FH AF Mortsch, LD Quinn, FH TI Climate change scenarios for Great Lakes Basin ecosystem studies SO LIMNOLOGY AND OCEANOGRAPHY LA English DT Article; Proceedings Paper CT Symposium on Regional Assessment of Freshwater Ecosystems and Climate Change in North America CY OCT 24-26, 1994 CL LEESBURG, VA SP Amer Soc Limnol & Oceanog, N Amer Benthol Soc, US EPA, US Geol Survey ID GENERAL-CIRCULATION MODEL; IMPACTS AB Significant change in global climate could occur due to human-induced changes in the chemistry of the atmosphere. We provide a basis for the continuing assessment of potential impacts of climate change on aquatic ecosystems. A series of climate change scenarios have been developed for the Great Lakes Basin using general circulation models (GCMs), climate spatial transpositions, and historical climate analogs. The direct impacts of climate change on the Great Lakes ecosystem would occur through higher air and water temperatures. Indirect climate change impacts include both positive and negative changes in precipitation, decreases riverine runoff, less snowfall and snowpack accumulation, higher evapotranspiration, and a reduction in lake levels and connecting channel flows. These climate and hydrologic changes affect the quantity and quality of wetland and aquatic habitats, alter the frequency and timing of lake turnover, and change dissolved oxygen, and alter fish community composition and dynamics. We provide an integration of Great Lakes climate scenarios. We also illustrate, for the first time, the spatial variability of the climate change scenarios on a tributary river-basin scale. C1 NOAA,GREAT LAKES ENVIRONM RES LAB,ANN ARBOR,MI 48105. RP Mortsch, LD (reprint author), CCIW,ATMOSPHER ENVIRONM SERV,ENVIRONM ADAPTAT RES GRP,867 LAKESHORE RD,BURLINGTON,ON L7R 4A6,CANADA. NR 24 TC 111 Z9 114 U1 1 U2 30 PU AMER SOC LIMNOLOGY OCEANOGRAPH PI LAWRENCE PA 810 EAST 10TH ST, LAWRENCE, KS 66044-8897 SN 0024-3590 J9 LIMNOL OCEANOGR JI Limnol. Oceanogr. PD JUL PY 1996 VL 41 IS 5 BP 903 EP 911 PG 9 WC Limnology; Oceanography SC Marine & Freshwater Biology; Oceanography GA VN458 UT WOS:A1996VN45800012 ER PT J AU Pellegrino, J Radebaugh, R Mattes, BR AF Pellegrino, J Radebaugh, R Mattes, BR TI Gas sorption in polyaniline .1. Emeraldine base SO MACROMOLECULES LA English DT Article ID TRANSPORT; POLYMERS; MEMBRANES; FILMS AB Measurements of the sorption isotherms (at 298 K) for Ar, O-2, and N-2 in several polyaniline emeraldine base (PANi-EB) forms were made (as-cast film, powder, and fully undoped film) over the pressure range 100-1300 kPa. Model fits of the sorption isotherms were made using a modified Flory-Huggins equation (MFHE) and a dual mode sorption equation. In general, the variation of parameters for the MFHE was consistent with morphological interpretations from prior X-ray scattering studies. The ordering of gas sorption with respect to a particular PANi-EB form correlates with the relative sizes and condensabilities of the gas molecules. We see evidence that the morphological variations between different PANi-EB forms, as indicated by their He densities and X-ray scattering data, affects the ratio of O-2/N-2 solubilities primarily through restricted access to available free volume. From our current measurements of solubilities and prior results for the O-2 and N-2 permeabilities, we conclude that the O-2/N-2 ideal separation factor is due to diffusivity selectivity in an as-cast PANi-EB him and solubility selectivity in a fully undoped one. C1 LOS ALAMOS NATL LAB,LOS ALAMOS,NM 87575. RP Pellegrino, J (reprint author), NATL INST STAND & TECHNOL,PHYS & CHEM PROPERTIES DIV,325 BROADWAY,83801 & 83809,BOULDER,CO 80303, USA. OI PELLEGRINO, JOHN/0000-0001-7749-5003 NR 23 TC 43 Z9 45 U1 0 U2 2 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 SN 0024-9297 J9 MACROMOLECULES JI Macromolecules PD JUL 1 PY 1996 VL 29 IS 14 BP 4985 EP 4991 DI 10.1021/ma951333x PG 7 WC Polymer Science SC Polymer Science GA UY489 UT WOS:A1996UY48900025 ER PT J AU Lamont, MM Vida, JT Harvey, JT Jeffries, S Brown, R Huber, HH DeLong, R Thomas, WK AF Lamont, MM Vida, JT Harvey, JT Jeffries, S Brown, R Huber, HH DeLong, R Thomas, WK TI Genetic substructure of the Pacific harbor seal (Phoca vittulina richardsi) off Washington, Oregon, and California SO MARINE MAMMAL SCIENCE LA English DT Article DE harbor seal; Phoca vitulina richardsi; polymerase chain reaction; mitochondrial DNA haplotypes; Puget Sound; genetic structure ID LIONS ZALOPHUS-CALIFORNIANUS; MITOCHONDRIAL-DNA SEQUENCE; VITULINA AB Genetic substructure among groups of Pacific harbor seals, Phaca vitulina richardsi, along the western coast of the United States was investigated using mitochondrial DNA sequences. Blood and tissue samples were removed from 86 seals inhabiting Puget Sound and the Pacific coasts of Washington, Oregon, and California. A 320 base-pair segment of the control region was amplified using the polymerase chain reaction and directly sequenced. These data indicated a high level of diversity. Thirty variable sites were found that: define 47 mitochondrial haplotypes. Among groups of P. v. richardsi sampled, 5 haplotypes were shared, but most (42) were unique to a locality. Haplotypic frequency and an Analysis of Molecular Variance (AMOVA) revealed significant differences (P = 0.001) among regions. Phylogenetic analysis indicated Puget Sound seals possess unique divergent lineages not found in seals from the coasts of Washington, Oregon, and California. These lineages may represent haplotypes from north of Washington, which is consistent: with late reproductive timing of harbor seals from Puget Sound. C1 UNIV MISSOURI,DEPT BIOL SCI,KANSAS CITY,MO 64110. WASHINGTON DEPT WILDLIFE,TACOMA,WA 98498. OREGON DEPT FISH & WILDLIFE,NEWPORT,OR 97365. NOAA,NATL MARINE FISHERIES SERV,NATL MARINE MAMMAL LAB,SEATTLE,WA 98115. RP Lamont, MM (reprint author), MOSS LANDING MARINE LABS,POB 450,MOSS LANDING,CA 95039, USA. NR 30 TC 28 Z9 29 U1 0 U2 6 PU SOC MARINE MAMMALOGY PI LAWRENCE PA 1041 NEW HAMPSHIRE ST, LAWRENCE, KS 66044 SN 0824-0469 J9 MAR MAMMAL SCI JI Mar. Mamm. Sci. PD JUL PY 1996 VL 12 IS 3 BP 402 EP 413 DI 10.1111/j.1748-7692.1996.tb00592.x PG 12 WC Marine & Freshwater Biology; Zoology SC Marine & Freshwater Biology; Zoology GA UZ741 UT WOS:A1996UZ74100005 ER PT J AU Miller, EH deLeon, AP DeLong, RL AF Miller, EH deLeon, AP DeLong, RL TI Violent interspecific sexual behavior by male sea lions (Otariidae): Evolutionary and phylogenetic implications SO MARINE MAMMAL SCIENCE LA English DT Article ID ZEALAND FUR SEALS; ARCTOCEPHALUS-FORSTERI; MONACHUS-SCHAUINSLANDI; SOCIAL-BEHAVIOR; PREDATION; BYRONIA; ISLANDS; MODEL; CYCLE; PERU C1 INST NACL PESCA,DIV MAMIFEROS MARINOS,MONTEVIDEO,URUGUAY. NATL MARINE MAMMAL LAB,SEATTLE,WA 98115. RP Miller, EH (reprint author), MEM UNIV NEWFOUNDLAND,DEPT BIOL,ST JOHNS,NF A1B 3X9,CANADA. NR 51 TC 23 Z9 23 U1 1 U2 4 PU SOC MARINE MAMMALOGY PI LAWRENCE PA 1041 NEW HAMPSHIRE ST, LAWRENCE, KS 66044 SN 0824-0469 J9 MAR MAMMAL SCI JI Mar. Mamm. Sci. PD JUL PY 1996 VL 12 IS 3 BP 468 EP 476 DI 10.1111/j.1748-7692.1996.tb00601.x PG 9 WC Marine & Freshwater Biology; Zoology SC Marine & Freshwater Biology; Zoology GA UZ741 UT WOS:A1996UZ74100014 ER PT J AU Lee, JS Tanabe, S Umino, H Tatsukawa, R Loughlin, TR Calkins, DC AF Lee, JS Tanabe, S Umino, H Tatsukawa, R Loughlin, TR Calkins, DC TI Persistent organochlorines in Steller sea lion (Eumetopias jubatus) from the bulk of Alaska and the Bering Sea, 1976-1981 SO MARINE POLLUTION BULLETIN LA English DT Article ID POLYCHLORINATED-BIPHENYLS; CHLORINATED HYDROCARBONS; HALICHOERUS-GRYPUS; COASTAL WATERS; ST-LAWRENCE; RESIDUES; CHLORDANE; DOLPHINS; GULF; FISH AB Organochlorine pesticides and polychlorinated biphenyls (PCBs) were determined in the blubber and liver of Steller sea lion collected from the bulk of Alaska and the Russian :Bering Sea, PCBs were the predominant organochlorines in the blubber, ranging in concentration from 5.7 to 41 mu g g(-1) (lipid weight) in males and from 0.57 to 16 mu g g(-1) in females. Concentrations of DDTs (DDT and its metabolites) in the blubber ranged from 2.8 to 17 mu g g(-1) in males and from 0.19 to 6.5 mu g g(-1) in females, The levels of chlordane compounds (CHLs) and hexachlorocyclohexanes (HCHs) were one to three orders of magnitude lower than those of PCBs and DDTs. The residue levels of PCBs, DDTs and CHLs in males increased with age, whereas in females they decreased sharply after maturity, suggesting the transfer of organochlorines in large quantities during lactation. Transfer rate of organochlorines through lactation was estimated to be 80% for PCBs and 79% for DDTs of the total body of adult female. Concentrations of organochlorines in the liver of the Steller sea lion from Alaska, on a lipid weight basis, were similar to those in the Blubber, In addition, liver showed age-dependent accumulation of PCBs, DDTs and CHLs, similar to that in the Blubber. The concentrations of all the organochlorines detected in the liver were clearly correlated with those in the blubber, indicating the lipophilic nature of organochlorines in accumulation and movement in the animal body, Residue levels of PCBs and DDTs in the liver of male Steller sea lions from the Bering Sea were significantly lower than those from Alaska, suggesting that Bering Sea animals have different foraging areas from the animals of the bulk of Alaska. Copyright (C) 1996 Elsevier Science Ltd C1 EHIME UNIV, DEPT ENVIRONM CONSERVAT, MATSUYAMA, EHIME 790, JAPAN. NATL MARINE FISHERIES SERV, NATL MARINE MAMMAL LAB, ALASKA FISHERIES SCI CTR, SEATTLE, WA 98115 USA. ALASKA DEPT FISH & GAME, ANCHORAGE, AK 99502 USA. RI Tanabe, Shinsuke/G-6950-2013 NR 46 TC 35 Z9 36 U1 0 U2 4 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLAND SN 0025-326X EI 1879-3363 J9 MAR POLLUT BULL JI Mar. Pollut. Bull. PD JUL PY 1996 VL 32 IS 7 BP 535 EP 544 DI 10.1016/0025-326X(96)84572-3 PG 10 WC Environmental Sciences; Marine & Freshwater Biology SC Environmental Sciences & Ecology; Marine & Freshwater Biology GA VK872 UT WOS:A1996VK87200012 ER PT J AU Betts, AK Hong, SY Pan, HL AF Betts, AK Hong, SY Pan, HL TI Comparison of NCEP-NCAR reanalysis with 1987 FIFE data SO MONTHLY WEATHER REVIEW LA English DT Article ID GENERAL-CIRCULATION MODELS; BOUNDARY-LAYER; SOIL HYDROLOGY; BUDGET; LAND; FLUXES; PARAMETERIZATION; CLIMATOLOGY; GRASSLAND; PRAIRIE AB Data from the FIFE experiment of the summer of 1987 are used to assess the diurnal and seasonal cycles of the surface energy budget and boundary layer in the NCEP-NCAR reanalysis, which used the summer 1995 version of the Medium-Range Forecast model. The seasonal agreement is quite good, reflecting the improvements in land-surface parameterizations in recent years. Detailed studies, however, identify several places where still further improvements in model parameterizations are possible. Clear-sky shortwave absorption and cloudiness may be underestimated in this model as has been noticed in other global models. More frequent updates of the model cloud cover (currently every 3 h) would improve the land-surface interaction after the initial onset of precipitation. The model produces a realistic well-mixed boundary layer, but underestimates boundary layer deepening by entrainment. For much of the summer, precipitation is close to that observed; however, for a period in June and early July, the reanalysis model has excess precipitation, which comes from daytime interactions between the surface evaporation, boundary layer, and convection schemes. The model, which has a deep 2-m soil reservoir, has adequate soil moisture storage for several weeks without rain, although surface evaporative fraction fluctuates more strongly after rain than is observed. Surface evaporation is generally too high at night, especially in high winds. This analysis suggests several improvements to the model parameterizations, some of which have already been implemented in the operational MRF model. C1 NCEP ENVIRONM MODELING CTR,WASHINGTON,DC. RI Betts, Alan/H-5282-2011; Hong, Song-You/I-3824-2012 NR 39 TC 60 Z9 61 U1 0 U2 7 PU AMER METEOROLOGICAL SOC PI BOSTON PA 45 BEACON ST, BOSTON, MA 02108-3693 SN 0027-0644 J9 MON WEATHER REV JI Mon. Weather Rev. PD JUL PY 1996 VL 124 IS 7 BP 1480 EP 1498 DI 10.1175/1520-0493(1996)124<1480:CONNRW>2.0.CO;2 PG 19 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA UX914 UT WOS:A1996UX91400009 ER PT J AU Avila, LA Rappaport, EN AF Avila, LA Rappaport, EN TI Atlantic hurricane season of 1994 SO MONTHLY WEATHER REVIEW LA English DT Article AB The 1994 Atlantic hurricane season had only three hurricanes forming from just seven tropical storms. Several of these tropical cyclones, however, caused loss of life and great damage. Gordon, as a tropical storm, produced floods that killed more than 1100 people in Haiti. Alberto, Beryl, and Gordon hit the United States, causing 38 deaths and nearly $1 billion in damage over the southeastern states. RP Avila, LA (reprint author), NOAA,NWS,NATL HURRICANE CTR,11691 SW 17TH ST,MIAMI,FL 33165, USA. NR 7 TC 15 Z9 15 U1 0 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 JUL PY 1996 VL 124 IS 7 BP 1558 EP 1578 DI 10.1175/1520-0493(1996)124<1558:AHSO>2.0.CO;2 PG 21 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA UX914 UT WOS:A1996UX91400014 ER PT J AU Pasch, RJ Mayfield, M AF Pasch, RJ Mayfield, M TI Eastern north Pacific hurricane season of 1994 SO MONTHLY WEATHER REVIEW LA English DT Article AB An account of the 1994 hurricane season in the eastern North Pacific Ocean is given. The numbers of hurricanes and tropical storms were near normal, but the activity tended to occur farther to the west in the basin than usual. Hurricane Rosa was the only system of the season to make landfall. RP Pasch, RJ (reprint author), NOAA,NWS,NATL HURRICANE CTR,11691 SW 17TH ST,MIAMI,FL 33165, USA. NR 5 TC 13 Z9 13 U1 0 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 JUL PY 1996 VL 124 IS 7 BP 1579 EP 1590 DI 10.1175/1520-0493(1996)124<1579:ENPHSO>2.0.CO;2 PG 12 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA UX914 UT WOS:A1996UX91400015 ER PT J AU Jentschel, M Heinig, KH Borner, HG Jolie, J Kessler, EG AF Jentschel, M Heinig, KH Borner, HG Jolie, J Kessler, EG TI Atomic collision cascades studied with the crystal-GRID method SO NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH SECTION B-BEAM INTERACTIONS WITH MATERIALS AND ATOMS LA English DT Article; Proceedings Paper CT 16th International Conference on Atomic Collisions in Solids (ICACS-16) CY JUL 17-21, 1995 CL LINZ, AUSTRIA SP Oberosterreich Landesregierung, Bundesminist Wissensch Forsch & Kunst, Wissensch Oberosterreich Wirtschaftskammer, Bank Oberosterreich & Salzburg, Osterreich Brau AG, Creditanstalt, Linzer Hochschulfonds, Jubilaumsfonds Osterreich Nationalbank, Rector Johannes Kepler Univ Linz, Magistrat Linz, Elsevier Sci B V, Edwards High Vacuum Int, Tectra Physikal Instrumente, EG & G Ortec, Vacuum Generators, Fisons ID GAMMA-SPECTROSCOPY; SIMULATION AB Atomic collision cascades within crystals can be produced by recoils induced by gamma-emission after thermal neutron capture, Subsequently emitted secondary gamma-quanta are Doppler shifted due to the motion of the recoiling atom. We report on the first observation of structure lineshape observed by Gamma-Ray Induced Doppler broadening (GRID) experiments using oriented single crystals. These allow a detailed study of the dynamics of atomic collision cascades and of interatomic potentials in the bulk of materials. C1 INST MAX VON LAUE PAUL LANGEVIN,F-38042 GRENOBLE,FRANCE. UNIV FRIBOURG,DEPT PHYS,CH-1700 FRIBOURG,SWITZERLAND. NIST,DEPT PHYS,GAITHERSBURG,MD 20899. RP Jentschel, M (reprint author), RES CTR ROSSENDORF,D-01314 DRESDEN,GERMANY. NR 16 TC 17 Z9 17 U1 0 U2 2 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0168-583X J9 NUCL INSTRUM METH B JI Nucl. Instrum. Methods Phys. Res. Sect. B-Beam Interact. Mater. Atoms PD JUL PY 1996 VL 115 IS 1-4 BP 446 EP 451 DI 10.1016/0168-583X(96)00166-8 PG 6 WC Instruments & Instrumentation; Nuclear Science & Technology; Physics, Atomic, Molecular & Chemical; Physics, Nuclear SC Instruments & Instrumentation; Nuclear Science & Technology; Physics GA VC425 UT WOS:A1996VC42500098 ER PT J AU Ye, J Ma, LS Hall, JL AF Ye, J Ma, LS Hall, JL TI Sub-Doppler optical frequency reference at 1.064 mu m by means of ultrasensitive cavity-enhanced frequency modulation spectroscopy of a C2HD overtone transition SO OPTICS LETTERS LA English DT Article ID SATURATED ABSORPTION; LINE AB Using our cavity-enhanced frequency modulation technique, we obtained the saturated signal of the weakly absorbing gas C2HD for the P(5) line of the (v(2) + 3v(3)) overtone band at 1.064 mu m. An absorption sensitivity of 1.2 X 10(-10) (1.8 X 10(-12)/cm) has been obtained. The absolute frequency of the line center is established (within +/-2.6 kHz) with respect to a doubled Nd:YAG laser/I-2 frequency reference. The short-term stability, limited by the available signal-to-noise ratio, currently is 1 X 10(-11) at 1 s, improving to 5 X 10(-13) at 1000 s. The measured pressure-broadening rate is 34.7(0.8) kHz/mTorr (260 + 6.1 kHz/Pa). gave a linewidth four times narrower than the room-temperature transit-time limit. (C) 1996 Optical Society of America C1 NATL INST STAND & TECHNOL,BOULDER,CO 80309. RP Ye, J (reprint author), UNIV COLORADO,JOINT INST LAB ASTROPHYS,BOULDER,CO 80309, USA. RI Ye, Jun/C-3312-2011 NR 14 TC 74 Z9 76 U1 2 U2 10 PU OPTICAL SOC AMER PI WASHINGTON PA 2010 MASSACHUSETTS AVE NW, WASHINGTON, DC 20036 SN 0146-9592 J9 OPT LETT JI Opt. Lett. PD JUL 1 PY 1996 VL 21 IS 13 BP 1000 EP 1002 DI 10.1364/OL.21.001000 PG 3 WC Optics SC Optics GA UU284 UT WOS:A1996UU28400030 PM 19876231 ER PT J AU Swart, PK Healy, GF Dodge, RE Kramer, P Hudson, JH Halley, RB Robblee, MB AF Swart, PK Healy, GF Dodge, RE Kramer, P Hudson, JH Halley, RB Robblee, MB TI The stable oxygen and carbon isotopic record from a coral growing in Florida Bay: A 160 year record of climatic and anthropogenic influence SO PALAEOGEOGRAPHY PALAEOCLIMATOLOGY PALAEOECOLOGY LA English DT Article ID REEF CORAL; TEMPERATURE; ANNULARIS; C-13 AB A 160 year record of skeletal delta(13)C and delta(18)O was examined in a specimen of the coral Solenastrea bournoni growing in Florida Bay. Variations in the delta(18)O of the skeleton can be correlated to changes in salinity while changes in the delta(13)C reflect cycling of organic material within the Bay. Based on the correlation between salinity and skeletal delta(18)O, we have concluded that there has been no long term increase in salinity in this area of Florida Bay over the past 160 years. Using salinity correlations between the various basins obtained from instrumental data, we have been able to extend our interpretations to other parts of Florida Bay reaching similar conclusions. In contrast to current ideas which have focused on changes in Florida Bay water quality over the past 20-yr history of the Bay as causative in its decline, we have determined that changes in water quality in this basin were already set in motion between 1905 and 1912 by the construction of the Florida East Coast Railway from Miami to Key West. The construction of the railway resulted in the restriction of the exchange of water between the Florida reef tract and the Gulf of Mexico causing Florida Bay to become more eutrophic. Evidence of this process is observed in the sudden shift to relatively lower delta(13)C values coincident with railway construction. Natural events also appear to have influenced the water in the Bay. Between 1912 and 1948 frequent hurricanes had the effect of increasing exchange of water between the Bay and reef tract and removing large quantities of organic rich sediments. However, since 1948 the number of hurricanes affecting the area has decreased and the products of the oxidation of organic material have been increasingly retained within the basin promoting the initiation of eutrophic conditions. C1 NOVA SE UNIV, OCEANOG CTR, DANIA, FL 33004 USA. NOAA, FKNMS, KEY LARGO, FL 33149 USA. USGS, ST PETERSBURG, FL 33705 USA. FLORIDA INT UNIV, NATL BIOL SURVEY, MIAMI, FL 33199 USA. RP UNIV MIAMI, ROSENSTIEL SCH MARINE & ATMOSPHER SCI, MGG, 4600 RICKENBACKER CAUSEWAY, MIAMI, FL 33149 USA. RI Swart, Peter/K-7041-2016 NR 26 TC 58 Z9 59 U1 2 U2 14 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0031-0182 EI 1872-616X J9 PALAEOGEOGR PALAEOCL JI Paleogeogr. Paleoclimatol. Paleoecol. PD JUL PY 1996 VL 123 IS 1-4 BP 219 EP 237 DI 10.1016/0031-0182(95)00078-X PG 19 WC Geography, Physical; Geosciences, Multidisciplinary; Paleontology SC Physical Geography; Geology; Paleontology GA UX647 UT WOS:A1996UX64700011 ER PT J AU Maier, HJ Keller, RR Renner, H Mughrabi, H Preston, A AF Maier, HJ Keller, RR Renner, H Mughrabi, H Preston, A TI On the unique evaluation of local lattice parameters by convergent-beam electron diffraction SO PHILOSOPHICAL MAGAZINE A-PHYSICS OF CONDENSED MATTER STRUCTURE DEFECTS AND MECHANICAL PROPERTIES LA English DT Article ID COPPER SINGLE-CRYSTALS; RANGE INTERNAL-STRESSES; ELASTIC RELAXATION; PHASE-TRANSFORMATIONS; EPITAXIAL LAYERS; DEFORMED COPPER; LINE POSITIONS; FOIL THICKNESS; SUPER-ALLOYS; STRAIN AB We summarize some practical aspects of using convergent-beam electron diffraction (CBED) patterns for determination of three-dimensional lattice parameters in crystalline materials. Owing to the insensitivities of certain lattice spacings to changes in lattice parameters, and to measurement errors imposed by finite higher-order Laue zone (HOLZ) linewidths, most CBED patterns can be simulated by a number of different lattice parameter combinations. Unique combinations are found by fitting several patterns obtained from the same area. In cases where a unique set of all six parameters cannot be found, semiquantitative information about elastic stress and strain states can still be extracted. The number of obtainable lattice parameters is affected by the symmetry of the pattern and by the specific HOLZ reflections which are present, for a given accelerating voltage. Symmetry-breaking distortions in patterns from nominally orthorhombic systems can often be attributed to deviations in lattice angles as small as 0.01-0.02 degrees away from 90 degrees, even if such angular distortions are not expected from knowledge of the material's bulk behaviour. The correct simulation of CBED patterns further requires consideration of foil thinning artefacts on HOLZ line positions. We show that an intelligent choice of zone axis can provide useful information even from difficult sample geometries. C1 NATL INST STAND & TECHNOL,DIV MAT RELIABIL,BOULDER,CO 80303. UNIV ERLANGEN NURNBERG,INST WERKSTOFFWISSENSCH,LEHRSTUHL 1,D-91058 ERLANGEN,GERMANY. UNIV CAMBRIDGE,DEPT MAT SCI & MET,CAMBRIDGE CB2 3QZ,ENGLAND. RP Maier, HJ (reprint author), UNIV GESAMTHSCH SIEGEN,INST WERKSTOFFTECH,FB 11,D-57068 SIEGEN,GERMANY. RI Keller, Robert/I-9014-2012 NR 44 TC 27 Z9 28 U1 1 U2 7 PU TAYLOR & FRANCIS LTD PI LONDON PA ONE GUNDPOWDER SQUARE, LONDON, ENGLAND EC4A 3DE SN 0141-8610 J9 PHILOS MAG A JI Philos. Mag. A-Phys. Condens. Matter Struct. Defect Mech. Prop. PD JUL PY 1996 VL 74 IS 1 BP 23 EP 43 PG 21 WC Materials Science, Multidisciplinary; Metallurgy & Metallurgical Engineering; Physics, Applied; Physics, Condensed Matter SC Materials Science; Metallurgy & Metallurgical Engineering; Physics GA VB011 UT WOS:A1996VB01100004 ER PT J AU Dodd, RJ Edwards, M Williams, CJ Clark, CW Holland, MJ Ruprecht, PA Burnett, K AF Dodd, RJ Edwards, M Williams, CJ Clark, CW Holland, MJ Ruprecht, PA Burnett, K TI Role of attractive interactions on Bose-Einstein condensation SO PHYSICAL REVIEW A LA English DT Article ID ATOMIC-HYDROGEN; RELAXATION RATES; SCATTERING AB The properties and stability of a trapped Bose-Einstein condensate are strongly influenced by attractive interactions between the particles. We describe the spatial distribution, stability, and collisional loss rates for a weakly interacting gas in the mean-field limit. We show how the condensate contracts and becomes unstable as the number of condensate atoms increases. We further show how the number of atoms is limited by the collisional loss rates associated with the contraction of the condensate; this loss is in addition to the particle ejection decay indentified by Kagan et al. C1 UNIV COLORADO,JILA,BOULDER,CO 80309. UNIV COLORADO,DEPT PHYS,BOULDER,CO 80309. UNIV OXFORD,DEPT PHYS,CLARENDON LAB,OXFORD OX1 3PU,ENGLAND. UNIV MARYLAND,INST PHYS SCI & TECHNOL,COLLEGE PK,MD 20742. GEORGIA SO COLL,DEPT PHYS,STATESBORO,GA 30460. UNIV CHICAGO,JAMES FRANCK INST,CHICAGO,IL 60637. RP Dodd, RJ (reprint author), NATL INST STAND & TECHNOL,PHYS LAB,TECHNOL ADM,US DEPT COMMERCE,GAITHERSBURG,MD 20899, USA. RI Clark, Charles/A-8594-2009; Williams, Carl/B-5877-2009 OI Clark, Charles/0000-0001-8724-9885; NR 22 TC 141 Z9 142 U1 0 U2 5 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 1050-2947 J9 PHYS REV A JI Phys. Rev. A PD JUL PY 1996 VL 54 IS 1 BP 661 EP 664 DI 10.1103/PhysRevA.54.661 PG 4 WC Optics; Physics, Atomic, Molecular & Chemical SC Optics; Physics GA UX034 UT WOS:A1996UX03400077 ER PT J AU Yildirim, T Barbedette, L Fischer, JE Lin, CL Robert, J Petit, P Palstra, TTM AF Yildirim, T Barbedette, L Fischer, JE Lin, CL Robert, J Petit, P Palstra, TTM TI T-c vs carrier concentration in cubic fulleride superconductors SO PHYSICAL REVIEW LETTERS LA English DT Article ID C-60; TRANSITION AB The effect of carrier concentration on fulleride superconductivity is studied by x ray, Raman, magnetization, and ESR of two new cubic families: Na2CsxC60 (0 < x < 1) and M(3-y)Ba(y)C(60) (0.2 < y < 2, M = K, Rb, or Cs). These are isostructural with known Pa(3) over bar and trivalent superconductors, respectively, but with variable valence 2 < n < 5. T-c is peaked at or very near n = 3, decreasing rapidly in either direction to < 0.5 K for n = 2.5 and 5. These results underscore the failure of both one-electron and strong correlation models to explain the dependence of T-c on band filling. C1 NATL INST STAND & TECHNOL,GAITHERSBURG,MD 20899. UNIV PENN,DEPT MAT SCI,PHILADELPHIA,PA 19104. UNIV PENN,RES STRUCT MATTER LAB,PHILADELPHIA,PA 19104. TEMPLE UNIV,DEPT PHYS,PHILADELPHIA,PA 19122. UNIV STRASBOURG 1,CNRS,INST CHARLES SADRON,F-67000 STRASBOURG,FRANCE. AT&T BELL LABS,MURRAY HILL,NJ 07974. RP Yildirim, T (reprint author), UNIV MARYLAND,COLLEGE PK,MD 20742, USA. RI yildirim, taner/A-1290-2009; Palstra, Thomas/K-1961-2013 OI Palstra, Thomas/0000-0001-5239-3115 NR 25 TC 94 Z9 96 U1 0 U2 5 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 0031-9007 J9 PHYS REV LETT JI Phys. Rev. Lett. PD JUL 1 PY 1996 VL 77 IS 1 BP 167 EP 170 DI 10.1103/PhysRevLett.77.167 PG 4 WC Physics, Multidisciplinary SC Physics GA UU475 UT WOS:A1996UU47500043 ER PT J AU Maynard, DJ McDowell, GC Tezak, EP Flagg, TA AF Maynard, DJ McDowell, GC Tezak, EP Flagg, TA TI Effect of diets supplemented with live food on the foraging behavior of cultured fall chinook salmon SO PROGRESSIVE FISH-CULTURIST LA English DT Article ID TROUT AB The use of diets supplemented with live food to increase the postrelease foraging ability of hatchery-reared fall chinook salmon Oncorhynchus tshawytscha was investigated. Replicate groups of fry were reared in six 2.4-m-diameter circular tanks and fed one of two diets. Fish in three tanks received a commercially available pelletized diet; fish in the other three tanks were given the opportunity to forage on natural live prey (mysids, mosquito larvae, chironomid larvae, and daphnia) prior to their daily ration of pellets. Foraging by individual fish was observed in special 200-L tanks, and fish conditioned to live food fed on twice as many familiar prey (chironomids) and novel prey (mayfly larvae) as unconditioned fish fed on. This suggests that diets supplemented with live food can be used to increase the postrelease foraging effectiveness of hatchery-reared chinook salmon. RP Maynard, DJ (reprint author), NOAA,NATL MARINE FISHERIES SERV,NW FISHERIES SCI CTR,COASTAL ZONE & ESTUARINE STUDIES DIV,SEATTLE,WA 98112, USA. NR 20 TC 24 Z9 24 U1 0 U2 3 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 JUL PY 1996 VL 58 IS 3 BP 187 EP 191 DI 10.1577/1548-8640(1996)058<0187:EODSWL>2.3.CO;2 PG 5 WC Fisheries SC Fisheries GA UX365 UT WOS:A1996UX36500006 ER PT J AU Pikin, AI Morgan, CA Bell, EW Ratliff, LP Church, DA Gillaspy, JD AF Pikin, AI Morgan, CA Bell, EW Ratliff, LP Church, DA Gillaspy, JD TI A beam line for highly charged ions SO REVIEW OF SCIENTIFIC INSTRUMENTS LA English DT Article ID RECOMBINATION CROSS-SECTIONS; HYDROGENLIKE; TRAP AB The design and operation of a beam line for transporting and charge-to-mass selecting highly charged ions extracted from the National Institute of Standards and Technology electron beam ion trap (EBIT) are described. This beam line greatly extends the range of experiments possible at this facility. Using the transport system, pure beams of low-energy, highly charged ions up to Xe44+ have been produced with substantially higher fluxes than previously reported from an EBIT source. Design choices and computer modeling for the various components of the beam line are explained in detail. (C) 1996 American Institute of Physics. C1 UNIV MARYLAND,COLLEGE PK,MD 20742. TEXAS A&M UNIV,DEPT PHYS,COLLEGE STN,TX 77843. NATL INST STAND & TECHNOL,BOULDER,CO 80309. UNIV COLORADO,JILA,BOULDER,CO 80309. RP Pikin, AI (reprint author), NIST,ATOM PHYS DIV,GAITHERSBURG,MD 20899, USA. NR 22 TC 23 Z9 23 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 JUL PY 1996 VL 67 IS 7 BP 2528 EP 2533 DI 10.1063/1.1147192 PG 6 WC Instruments & Instrumentation; Physics, Applied SC Instruments & Instrumentation; Physics GA UW834 UT WOS:A1996UW83400015 ER PT J AU Cavicchi, RE Suehle, JS Kreider, KG Gaitan, M Chaparala, P AF Cavicchi, RE Suehle, JS Kreider, KG Gaitan, M Chaparala, P TI Optimized temperature-pulse sequences for the enhancement of chemically specific response patterns from micro-hotplate gas sensors SO SENSORS AND ACTUATORS B-CHEMICAL LA English DT Article; Proceedings Paper CT 8th International Conference on Solid-State Sensors and Actuators (Eurosensors IX) CY JUN 25-29, 1995 CL STOCKHOLM, SWEDEN DE micromachining; micro-hotplates; gas sensors; temperature programming; tin oxide ID CARBON-MONOXIDE AB Microfabricated solid-state gas sensors have been of continuing interest because of the potential for arrays of devices with low power consumption. Devices based on a micromachined 'hotplate' offer the additional advantage of a wide operating temperature range with a rapid thermal time constant of order 1 ms. By operating the device in a temperature-programmed mode, reaction kinetics on the sensing film surface are altered, producing a time-varying response signature that is characteristic of the gas being sensed. Approaches to optimizing such temperature programs to maximize the differences in response signatures for gases of interest or to enhance the sensitivity of the device are discussed. C1 UNIV MARYLAND,COLLEGE PK,MD 20742. RP Cavicchi, RE (reprint author), NIST,CHEM SCI & TECHNOL LAB,GAITHERSBURG,MD 20899, USA. NR 10 TC 68 Z9 71 U1 1 U2 2 PU ELSEVIER SCIENCE SA LAUSANNE PI LAUSANNE 1 PA PO BOX 564, 1001 LAUSANNE 1, SWITZERLAND SN 0925-4005 J9 SENSOR ACTUAT B-CHEM JI Sens. Actuator B-Chem. PD JUL PY 1996 VL 33 IS 1-3 BP 142 EP 146 DI 10.1016/0925-4005(96)01821-7 PG 5 WC Chemistry, Analytical; Electrochemistry; Instruments & Instrumentation SC Chemistry; Electrochemistry; Instruments & Instrumentation GA VK201 UT WOS:A1996VK20100026 ER PT J AU Passi, RM Goodrich, RK Limber, M Derber, JC AF Passi, RM Goodrich, RK Limber, M Derber, JC TI A convolution algorithm with application to data assimilation SO SIAM JOURNAL ON SCIENTIFIC COMPUTING LA English DT Article DE operator polynomials; Gaussian function; separable functions; data assimilation; product polynomial algorithm AB A computationally efficient algorithm to approximate a convolution w * f is derived when the real-valued weighting functions w are dimensionally separable, i.e., w(x(1),x(2)) = w(1)(x(1))w(2)(x(2)) and w(x(k)) = w(-x(k)), and the function f(i, j) is defined on a discrete integer lattice in R2, The algorithm consists of a product of operator polynomials P-k(D-k), k = 1, 2, which are composed of simple averaging operators D-k operating on f. It generalizes the smoothing algorithm of Goodrich, Passi, and Limber [Pror. 24th Symposium on the Interface: Computing Science and Statistics, 1992] for data constrained to a uniformly spaced, large-dimensioned orthogonal grid lying in a two-dimensional space, using a Gaussian weighting function w(r) = exp(-r(2)/b(2)). The new algorithm has a direct application to data assimilation problems in meteorology and oceanography. Data assimilation optimally combines output of a numerical model with observational data to derive more accurate initial conditions needed for numerical integration of the model equations. Computer simulations with the algorithm were found to be about ten times faster than a comparable algorithm of Derber and Rosati [J. Phys. Ocean, (1989), pp.1333-1347]. C1 UNIV COLORADO,DEPT MATH,BOULDER,CO 80309. NOAA,NATL WEATHER SERV,WASHINGTON,DC 20233. RP Passi, RM (reprint author), CTR OCEAN & ATMOSPHER MODELING,BAY ST LOUIS,MS 39529, USA. NR 14 TC 0 Z9 0 U1 0 U2 0 PU SIAM PUBLICATIONS PI PHILADELPHIA PA 3600 UNIV CITY SCIENCE CENTER PH#382-9800, PHILADELPHIA, PA 19104-2688 SN 1064-8275 J9 SIAM J SCI COMPUT JI SIAM J. Sci. Comput. PD JUL PY 1996 VL 17 IS 4 BP 942 EP 955 DI 10.1137/0917061 PG 14 WC Mathematics, Applied SC Mathematics GA UV643 UT WOS:A1996UV64300010 ER PT J AU Janardhan, P Balasubramanian, V Ananthakrishnan, S Dryer, M Bhatnagar, A McIntosh, PS AF Janardhan, P Balasubramanian, V Ananthakrishnan, S Dryer, M Bhatnagar, A McIntosh, PS TI Travelling interplanetary disturbances detected using interplanetary scintillation at 327 MHz SO SOLAR PHYSICS LA English DT Article ID SOLAR-WIND; SHOCKS; SUN AB Based on the advance predictions of two flare-generated shock fronts, obtained from the Space Environment Centre (SEC, NOAA, Boulder), observations of interplanetary scintillation (IPS) were carried out with the Ooty Radio Telescope (ORT) on a grid of appropriately located sources during the period 31 October to 5 November, 1992. Solar wind velocities were derived by fitting model spectra to the observed spectra and two travelling interplanetary disturbances were detected. Both disturbances were traced back to an active region on the Sun which was located close to a large coronal hole. The roles of flares and coronal holes in producing such disturbances are examined and it is shown that in the present case both the coronal hole and the active region probably played key roles in generating the two IFS disturbances. C1 PHYS RES LAB,AHMEDABAD 380009,GUJARAT,INDIA. TIFR,RADIO ASTRON CTR,UDHAGAMANDALAM OOT 643001,INDIA. TIFR,NATL CTR RADIO ASTROPHYS,PUNE 411007,MAHARASHTRA,INDIA. UNIV COLORADO,SPACE ENVIRONM CTR,COOPERAT INST RES ENVIRONM SCI,NOAA,BOULDER,CO 80303. UDAIPUR SOLAR OBSERV,UDAIPUR 313001,INDIA. NR 37 TC 33 Z9 34 U1 0 U2 1 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 JUL PY 1996 VL 166 IS 2 BP 379 EP 401 DI 10.1007/BF00149405 PG 23 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA UX481 UT WOS:A1996UX48100010 ER PT J AU Joos, F Bruno, M Fink, R Siegenthaler, U Stocker, TF LeQuere, C AF Joos, F Bruno, M Fink, R Siegenthaler, U Stocker, TF LeQuere, C TI An efficient and accurate representation of complex oceanic and biospheric models of anthropogenic carbon uptake SO TELLUS SERIES B-CHEMICAL AND PHYSICAL METEOROLOGY LA English DT Article ID ATMOSPHERIC CO2 CONCENTRATIONS; DISSOCIATION-CONSTANTS; CIRCULATION MODEL; DISTRIBUTIONS; RADIOCARBON; SIMULATIONS; SEAWATER; CYCLE; ACID AB Establishing the link between atmospheric CO2 concentration and anthropogenic carbon emissions requires the development of complex carbon cycle models of the primary sinks, the ocean and terrestrial biosphere. Once such models have been developed, the potential exists to use pulse response functions to characterize their behaviour. However, the application of response functions based on a pulse increase in atmospheric CO2 to characterize oceanic uptake, the conventional technique, does not yield a very accurate result due to nonlinearities in the aquatic carbon chemistry. Here, we propose the use of an ocean mixed-layer pulse response function that characterizes the surface to deep ocean mixing in combination with a separate equation describing air-sea exchange. The use of a mixed-layer pulse response function avoids the problem arising from the nonlinearities of the carbon chemistry and gives therefore more accurate results. The response function is also valid for tracers other than carbon. We found that tracer uptake of the HILDA and Box-Diffusion model can be represented exactly by the new method. For the Princeton 3-D model, we find that the agreement between the complete model and its pulse substitute is better than 4% for the cumulative uptake of anthropogenic carbon for the period 1765 to 2300 applying the IPCC stabilisation scenarios S450 and S750 and better than 2% for the simulated inventory and surface concentration of bomb-produced radiocarbon. By contrast, the use of atmospheric response functions gives deviations up to 73% for the cumulative CO2 uptake as calculated with the Princeton 3-D model. We introduce the use of a decay response function for calculating the potential carbon storage on land as a substitute for terrestrial biosphere models that describe the overturning of assimilated carbon. This, in combination with an equation describing the net primary productivity permits us to exactly characterize simple biosphere models. As the time scales of biospheric overturning are one key aspect to determine the amount of anthropogenic carbon which might be sequestered by the biosphere, we suggest that decay response functions should be used as a simple and standardized measure to compare different models and to improve understanding of their behaviour. We provide analytical formulations for mixed-layer and terrestrial biosphere decay pulse response functions which permit us to easily build a substitute for the ''Bern'' carbon cycle model (HILDA). Furthermore, mixed-layer response functions for the Box-Diffusion, a 2-D model, and the Princeton 3-D model are given. C1 PRINCETON UNIV,ATMOSPHER & OCEAN SCI PROGRAM,PRINCETON,NJ 08544. RP Joos, F (reprint author), UNIV BERN,INST PHYS,CH-3012 BERN,SWITZERLAND. RI Stocker, Thomas/B-1273-2013; Le Quere, Corinne/C-2631-2017; OI Le Quere, Corinne/0000-0003-2319-0452; Joos, Fortunat/0000-0002-9483-6030 NR 32 TC 203 Z9 205 U1 2 U2 26 PU MUNKSGAARD INT PUBL LTD PI COPENHAGEN PA 35 NORRE SOGADE, PO BOX 2148, DK-1016 COPENHAGEN, DENMARK SN 0280-6509 J9 TELLUS B JI Tellus Ser. B-Chem. Phys. Meteorol. PD JUL PY 1996 VL 48 IS 3 BP 397 EP 417 DI 10.1034/j.1600-0889.1996.t01-2-00006.x PG 21 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA UY591 UT WOS:A1996UY59100006 ER PT J AU Wallace, WE Wu, WL Carpio, RA AF Wallace, WE Wu, WL Carpio, RA TI Chemical-mechanical polishing of SiO2 thin films studied by X-ray reflectivity SO THIN SOLID FILMS LA English DT Article DE silicon oxide; surface roughness; chemical vapour deposition; depth profiling ID OFF-SPECULAR REFLECTION; FLAT INTERFACES; PLANARIZATION AB Specular X-ray reflectivity from SiO2 thin films prepared on silicon substrates by plasma-enhanced chemical vapor deposition showed the films to have a characteristic width of the decay in density at the free surface of 17 Angstrom, to be about three-quarters the density of alpha-quartz, and to have an interfacial layer at the silicon interface that was of the order of 100 Angstrom wide and less dense than the bulk of the film. After chemical-mechanical polishing the characteristic width of the decay in density at the free surface was reduced to 10 Angstrom; furthermore, the near-surface region to a depth of 30 Angstrom had a greater density than the as-deposited film. Off-specular reflectivity confirmed that the decrease in characteristic width at the free surface was due to reduced roughness upon polishing and also revealed that the lateral correlation length in the limit of long wavelengths was the same for both polished and unpolished samples. The compression of the near-surface region during polishing is believed to enhance the dissolution of SiO2 into the slurry which is necessary to achieve smooth surfaces. C1 SEMATECH,AUSTIN,TX 78741. RP Wallace, WE (reprint author), NIST,BLDG 224,RM B320,GAITHERSBURG,MD 20899, USA. NR 21 TC 11 Z9 11 U1 0 U2 7 PU ELSEVIER SCIENCE SA LAUSANNE PI LAUSANNE 1 PA PO BOX 564, 1001 LAUSANNE 1, SWITZERLAND SN 0040-6090 J9 THIN SOLID FILMS JI Thin Solid Films PD JUL PY 1996 VL 280 IS 1-2 BP 37 EP 42 DI 10.1016/0040-6090(95)08178-X PG 6 WC Materials Science, Multidisciplinary; Materials Science, Coatings & Films; Physics, Applied; Physics, Condensed Matter SC Materials Science; Physics GA VD940 UT WOS:A1996VD94000006 ER PT J AU Smith, JA Seo, DJ Baeck, ML Hudlow, MD AF Smith, JA Seo, DJ Baeck, ML Hudlow, MD TI An intercomparison study of NEXRAD precipitation estimates SO WATER RESOURCES RESEARCH LA English DT Article ID LONG-RANGE; RAINFALL; RADAR; REFLECTIVITY AB Systematic biases in WSR-88D (Weather Surveillance Radar-1988 Doppler) hourly precipitation accumulation estimates are characterized from analyses of more than 1 year of WSR-88D data and rain gage data from the southern plains. Biases are examined in three contexts: (1) biases that arise from the range-dependent sampling of the WSR-88D, (2) systematic differences in radar rainfall estimates from two radars observing the same area, and (3) systematic differences between radar and rain gage estimates of rainfall. Range-dependent biases affect hourly rainfall accumulations products over much of the area covered by the WSR-88D. Significant underestimation of rainfall occurs within 40 km range of the radar due to bias in reflectivity observations at the higher elevation angles used for rainfall estimation close to the radar. Bright band and anomalous propagation (AP) lead to systematic overestimation of rainfall at intermediate range. Beyond 150 km in spring-summer and beyond 100 km in winter-fall, underestimation of precipitation is pronounced due to incomplete beam filling and overshooting of precipitation. Radar-radar intercomparison studies suggest that radar calibration is a significant problem at some sites. Anomalous propagation during clear-air conditions, a major problem with previous National Weather Service network radars, has been largely eliminated by the WSP-88D processing. AP remains a problem for cases in which AP returns are embedded in rain. Radar-rain gage intercomparison analyses indicate systematic underestimation by the WSR-88D relative to rain gages for paired gage-radar rainfall estimates. Analyses of spatial coverage of heavy rainfall, however, illustrate fundamental advantages of radar over rain gage networks for rainfall estimation. C1 NOAA,NATL WEATHER SERV,OFF HYDROL,SILVER SPRING,MD 20910. NOAA,NATL WEATHER SERV,HYDROL RES LAB,SILVER SPRING,MD 20910. RP Smith, JA (reprint author), PRINCETON UNIV,DEPT CIVIL ENGN & OPERAT RES,PRINCETON,NJ 08544, USA. NR 30 TC 220 Z9 224 U1 0 U2 8 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 SN 0043-1397 J9 WATER RESOUR RES JI Water Resour. Res. PD JUL PY 1996 VL 32 IS 7 BP 2035 EP 2045 DI 10.1029/96WR00270 PG 11 WC Environmental Sciences; Limnology; Water Resources SC Environmental Sciences & Ecology; Marine & Freshwater Biology; Water Resources GA UV613 UT WOS:A1996UV61300012 ER PT J AU Seo, DJ Smith, JA AF Seo, DJ Smith, JA TI Characterization of the climatological variability of mean areal rainfall through fractional coverage SO WATER RESOURCES RESEARCH LA English DT Article AB The role of fractional coverage in climatological variability of mean areal rainfall is investigated. Under second-order homogeneity assumptions, climatological variability of mean areal rainfall, as measured by its coefficient of variation, is shown to be a function of mean fractional coverage, conditional coefficient of variation of point rainfall, and two correlation scales associated with inner variability and intermittency of point rainfall. To verify the analytical results, empirical analyses are performed using hourly rainfall data from nine Weather Surveillance Radar-1988 Doppler (WSR-88D) radars in the southern plains, United States. The results indicate that given the local rainfall climatology there exists a catchment scale at which the climatological variability of mean areal rainfall is at its maximum. Existence of such a scale has been hypothesized and demonstrated via an analytical treatment of an idealized situation by Eagleson and Wang [1985], but only in climatological variability of fractional coverage (i.e., variability due only to intermittency). Sensitivity analyses for the correlation-scale parameters indicate that intermittency plays as important a role as inner variability in shaping the catchment scale-climatological variability relationship of mean areal rainfall. Decomposition of total variability indicates that over the range of catchment scales that fall within a single WSR-88D radar umbrella (effective radius of 230 km) the integrated contribution from intermittency is almost as large as that from inner variability. C1 PRINCETON UNIV,DEPT CIVIL ENGN & OPERAT RES,PRINCETON,NJ 08544. RP Seo, DJ (reprint author), NOAA,NATL WEATHER SERV,HYDROL RES LAB,1325 EW HIGHWAY,W-073,SILVER SPRING,MD 20910, USA. NR 15 TC 16 Z9 16 U1 0 U2 1 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 SN 0043-1397 J9 WATER RESOUR RES JI Water Resour. Res. PD JUL PY 1996 VL 32 IS 7 BP 2087 EP 2095 DI 10.1029/96WR00486 PG 9 WC Environmental Sciences; Limnology; Water Resources SC Environmental Sciences & Ecology; Marine & Freshwater Biology; Water Resources GA UV613 UT WOS:A1996UV61300017 ER PT J AU Wang, YS Hsu, SM AF Wang, YS Hsu, SM TI Wear and wear transition modeling of ceramics SO WEAR LA English DT Article DE ceramics; critical damage stress; maximum tensile stress; wear mechanism; wear model; wear transition model ID CONTACT; ALUMINA AB Wear and wear transitions are the major concerns regarding the tribological application of ceramic materials. The objective of this study is to understand wear and wear transition mechanisms of ceramics with emphasis on wear and wear transition prediction. There are four new findings from this research. First, the critical external damage stress (sigma(D)) from a fracture mechanics model was modified to predict wear transitions for ceramics and was able to account for the effects of grain size and internal residual stresses on wear transitions. Then, the tensile stress at the rear edge of the contact was found as the predominant stress which causes the ceramics to crack and leads to the subsequent wear transitions. The ratio of the maximum tensile stress (sigma(max)) and the critical external damage stress (sigma(D)) was found to be the critical parameter controlling wear transitions. Thirdly, a technique of ball sliding on inclined plane was developed for the approximation of the critical external damage stress for ceramics. Finally, a predictive wear model was developed. The correlation of the model with the experimental data of alumina and silicon nitride shows encouraging agreement. The distinctive features of this simplistic model are its ability to predict the wear transitions as well as estimate the wear of the brittle materials. C1 NATL INST STAND & TECHNOL, DIV CERAM, GAITHERSBURG, MD 20899 USA. RP Wang, YS (reprint author), EATON CORP, ENGINE COMPONENTS DIV, CTR TECH, 19218 B DR S, MARSHALL, MI 49068 USA. NR 33 TC 21 Z9 23 U1 0 U2 3 PU ELSEVIER SCIENCE SA PI LAUSANNE PA PO BOX 564, 1001 LAUSANNE, SWITZERLAND SN 0043-1648 EI 1873-2577 J9 WEAR JI Wear PD JUL PY 1996 VL 195 IS 1-2 BP 35 EP 46 DI 10.1016/0043-1648(95)06750-7 PG 12 WC Engineering, Mechanical; Materials Science, Multidisciplinary SC Engineering; Materials Science GA UT530 UT WOS:A1996UT53000004 ER PT J AU Wang, YS Hsu, SM AF Wang, YS Hsu, SM TI The effects of operating parameters and environment on the wear and wear transition of alumina SO WEAR LA English DT Article DE alumina; ceramics; wear; wear transition ID ABRASIVE WEAR; ALPHA-ALUMINA; GRAIN-SIZE; CERAMICS; MECHANISM; MILD; MAPS AB Systematic wear tests were conducted with varying speeds, loads, temperatures and conditions of lubrication to investigate the influence of the operating parameters and environment on the wear and wear transitions of alumina. Time-dependent wear transition was observed in alumina without any lubrication. Water and paraffin oil significantly reduce wear and increase the wear transition load of alumina. For comparison, tests were also conducted in paraffin oil with other advanced ceramics, e.g. silicon nitride, silicon carbide and zirconia. It was found that alumina is comparable with other ceramics as far as the pre-transition wear resistance is concerned, however, the wear transition load for alumina is the lowest among the materials tested. The effects of grain size and surface roughness on wear and wear transitions were also investigated with specially processed aluminas. Surface roughness has a significant effect on the wear-in of alumina, however, the influence is diminished at the steady state wear stage. Different grain sizes change the wear transition load and smaller grain size alumina has higher wear transition resistance than larger grain size ones. C1 NATL INST STAND & TECHNOL,DIV CERAM,GAITHERSBURG,MD 20899. RP Wang, YS (reprint author), EATON CORP,ENGINE COMPONENTS DIV,CTR TECH,19218 B DR S,MARSHALL,MI 49068, USA. NR 24 TC 23 Z9 24 U1 0 U2 3 PU ELSEVIER SCIENCE SA LAUSANNE PI LAUSANNE 1 PA PO BOX 564, 1001 LAUSANNE 1, SWITZERLAND SN 0043-1648 J9 WEAR JI Wear PD JUL PY 1996 VL 195 IS 1-2 BP 90 EP 99 DI 10.1016/0043-1648(95)06794-9 PG 10 WC Engineering, Mechanical; Materials Science, Multidisciplinary SC Engineering; Materials Science GA UT530 UT WOS:A1996UT53000010 ER PT J AU Wang, YS Hsu, SM AF Wang, YS Hsu, SM TI Wear and wear transition mechanisms of ceramics SO WEAR LA English DT Article DE alumina; ceramics; inclined-plane sliding; indentation; silicon carbide; silicon nitride; wear; wear mechanism; wear transition ID SILICON-NITRIDE; ALUMINA CERAMICS; MATERIAL REMOVAL; ABRASIVE WEAR; FRICTION; DEFORMATION; WATER; LUBRICATION; INDENTATION; FRACTURE AB The combination of indentation, inclined-plane sliding, and wear tests provides useful and unique way to investigate ceramic wear and wear transition mechanisms. The experimental results show that wear mechanisms of ceramics are predominantly dependent on the tribological contact stresses. At low contact stress, the removal of material is controlled by plastic deformation induced microfracture on the asperity contact scale. Wear debris are produced when the plastic deformation exceeds the plasticity limit of the material, which is very limited for ceramics. As the tribological stress increases and reaches a critical point, various kinds of cracks (such as partial cone cracks, lateral/shallow cracks, and radial cracks etc.) are initiated. These cracks can propagate owing to subsequential contact or at higher contact stress. When these cracks intersect each other, chunks of material are detached from the bulk material and crushed by the subsequential tribological contact into fine particles and carried away from the contact region as wear debris. Wear transitions from deformation- to crack/fracture-controlled wear in ceramics can be attributed to the change of wear mechanisms during the sliding contact due to the tribological stress exceeding the critical microcrack stress or the fracture stress. With the inclined plane sliding test, a wide range of stresses can be applied progressively under one single sliding and the critical stress of the transition can be estimated. By using the results of repeated sliding test on an inclined plane, the wear and wear transition mechanisms have been demonstrated. Although ceramic wear mechanisms are dominated by fracture processes, tribochemical reaction products may be present to moderate the stress distribution by providing a reaction layer for wear protection. C1 NATL INST STAND & TECHNOL,DIV CERAM,GAITHERSBURG,MD 20899. RP Wang, YS (reprint author), EATON CORP,ENGINE COMPONENTS DIV,CTR TECH,19218 B DR S,MARSHALL,MI 49068, USA. NR 41 TC 76 Z9 80 U1 3 U2 11 PU ELSEVIER SCIENCE SA LAUSANNE PI LAUSANNE 1 PA PO BOX 564, 1001 LAUSANNE 1, SWITZERLAND SN 0043-1648 J9 WEAR JI Wear PD JUL PY 1996 VL 195 IS 1-2 BP 112 EP 122 DI 10.1016/0043-1648(95)06800-7 PG 11 WC Engineering, Mechanical; Materials Science, Multidisciplinary SC Engineering; Materials Science GA UT530 UT WOS:A1996UT53000013 ER PT J AU Liu, HY Hsu, SM AF Liu, HY Hsu, SM TI Modeling of microfracture-induced wear and wear transition in sliding of polycrystalline alumina ceramics SO WEAR LA English DT Article DE ceramics; alumina; wear transition; microfracture; sliding wear; contact area ID GRAIN-SIZE; STRESS AB An equation has been proposed to describe sliding wear caused by microfracture in polycrystalline alumina ceramics. The wear equation has been simplified, and grain size dependence for dry sliding wear data by Wu et al. has been shown to agree with this equation. For lubricated sliding in a ball-on-flat configuration, modification of the equation is necessary. A concept of equivalent ''real'' contact area for lubricated contacts is introduced to account for the different stresses at the interface as the contact conditions change before and after a wear transition. Microfracture occurs when superimposed stress exceeds a critical threshold. The decrease in surface conformity due to surface roughening and trapping of pulled-out grains can significantly increase the magnitude of the contact stresses, which leads to high wear rates. We incorporate the contact geometry effects into the microfracture wear equation. This new wear equation provides a self-consistent data fitting of load dependent wear transition in lubricated sliding of alumina observed by Cho et al. The implications of this model are discussed. RP Liu, HY (reprint author), NATL INST STAND & TECHNOL,DIV CERAM,GAITHERSBURG,MD 20899, USA. NR 16 TC 10 Z9 11 U1 0 U2 1 PU ELSEVIER SCIENCE SA LAUSANNE PI LAUSANNE 1 PA PO BOX 564, 1001 LAUSANNE 1, SWITZERLAND SN 0043-1648 J9 WEAR JI Wear PD JUL PY 1996 VL 195 IS 1-2 BP 169 EP 177 DI 10.1016/0043-1648(95)06827-9 PG 9 WC Engineering, Mechanical; Materials Science, Multidisciplinary SC Engineering; Materials Science GA UT530 UT WOS:A1996UT53000020 ER PT J AU Kattner, UR Boettinger, WJ Coriell, SR AF Kattner, UR Boettinger, WJ Coriell, SR TI Application of Lukas' phase diagram programs to solidification calculations of multicomponent alloys SO ZEITSCHRIFT FUR METALLKUNDE LA English DT Article ID MODEL; MICROSEGREGATION; SYSTEM; GROWTH; PATHS AB A multicomponent thermodynamic calculation of the phase boundaries between liquid and various solid phases has been applied to the analysis of solidification problems for commercial alloys. The thermodynamic calculation was directly linked to micromodel codes which analyze the transport of solute in the phases using various diffusion models, This approach treats the temperature and/or concentration dependence of partition coefficients and liquidus slopes and of the formation of secondary solid phases, factors that are often neglected in solidification analysis, With an accurate set of thermodynamic parameters, analysis can be performed for alloys of the same base metal but with different levels of alloying agents. Calculations are presented for a Scheil model and for models that include solid diffusion and diffusion in the liquid at the dendrite tip. RP Kattner, UR (reprint author), NIST,DIV MET,BLDG 223,A153,GAITHERSBURG,MD 20899, USA. NR 38 TC 40 Z9 40 U1 0 U2 3 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 JUL PY 1996 VL 87 IS 7 BP 522 EP 528 PG 7 WC Metallurgy & Metallurgical Engineering SC Metallurgy & Metallurgical Engineering GA UY626 UT WOS:A1996UY62600002 ER PT J AU Kato, S deGouw, JA Lin, CD Bierbaum, VM Leone, SR AF Kato, S deGouw, JA Lin, CD Bierbaum, VM Leone, SR TI Charge-transfer rate constants for N-2(+)(v=O-4) with Ar at thermal energies SO CHEMICAL PHYSICS LETTERS LA English DT Article ID ION-MOLECULE REACTIONS; LASER-INDUCED FLUORESCENCE; STATE-TO-STATE AB Rate constants for the charge-transfer reaction N-2(+)(upsilon) + Ar --> N-2 + Ar+ are measured at thermal energies as a function of initial vibrational excitation by laser-induced fluorescence. The reaction is slow for upsilon = 0, whereas the rate constants for upsilon = 1-4 are large (approximate to 0.5 Langevin rate) and show little dependence on the vibrational level. The rate constants are quantitatively described by a simple model based on energy resonance and a set of modified Franck-Condon factors, which take into account the change in vibrational wave functions of N-2(+) and N-2 at short (N-2-Ar)(+) distances. C1 NATL INST STAND & TECHNOL,JOINT INST LAB ASTROPHYS,BOULDER,CO 80309. UNIV COLORADO,DEPT CHEM & BIOCHEM,BOULDER,CO 80309. UNIV COLORADO,DEPT PHYS,BOULDER,CO 80309. RI de Gouw, Joost/A-9675-2008 OI de Gouw, Joost/0000-0002-0385-1826 NR 18 TC 26 Z9 26 U1 2 U2 5 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0009-2614 J9 CHEM PHYS LETT JI Chem. Phys. Lett. PD JUN 28 PY 1996 VL 256 IS 3 BP 305 EP 311 DI 10.1016/0009-2614(96)00452-6 PG 7 WC Chemistry, Physical; Physics, Atomic, Molecular & Chemical SC Chemistry; Physics GA UU718 UT WOS:A1996UU71800011 ER PT J AU Meehl, GA Kiladis, GN Weickmann, KM Wheeler, M Gutzler, DS Compo, GP AF Meehl, GA Kiladis, GN Weickmann, KM Wheeler, M Gutzler, DS Compo, GP TI Modulation of equatorial subseasonal convective episodes by tropical-extratropical interaction in the Indian and Pacific Ocean regions SO JOURNAL OF GEOPHYSICAL RESEARCH-ATMOSPHERES LA English DT Article ID 30-60 DAY OSCILLATION; WESTERN PACIFIC; NORTHERN WINTER; MONSOON; MONEX AB Composite relationships among outgoing longwave radiation, sea level pressure, surface winds, and upper tropospheric circulation are examined for northern winter during subseasonal episodes of eastward progression of convection from the Indian Ocean to the western Pacific. This evolution often culminates with westerly wind burst events and strong air-sea interaction associated with regional-scale convective blowups in the western equatorial Pacific, We first document some of these interactions in the composites for two timescales, the submonthly (6-30 days) and that of the Madden-Julian Oscillation (MJO) timescale (30-70 days). We then analyze the December 1992 period during the Tropical Ocean Global Atmosphere Coupled Ocean-Atmosphere Response Experiment (TOGA COARE) to illustrate how these composite relationships are manifested in a case study, Convection in the Indian Ocean for the composites is shown to be associated with a northern hemisphere wave train at 200 mbar, arcing through the midlatitudes, that can contribute to convective blowups farther east on the submonthly (6-30 days) timescale in the Intertropical Convergence Zone (ITCZ) in the eastern Pacific. The eastern Asian trough that is part of this wave train is associated with pressure surges from the northern hemisphere and subsequent convection over Southeast Asia. As the MJO convective envelope moves east to Australasia, midlatitude wave trains in either hemisphere include upper level troughs east of Asia and Australia and pressure surges from either hemisphere that contribute to pressure rises over the Indonesian region and a subsequent shift of the convective envelope to the western Pacific, The vertical wind structure for the December 1992 case study is consistent with the composite surface and upper level winds and also shows strong vertical wind shear in the boundary layer, a sharply defined westerly maximum near 700 mbar and an intensification of the upper level easterlies near 100 mbar, Very deep westerlies (to 200 mbar) are confined to shorter timescales, The case study illustrates the various time and space scale interactions noted in the composites, Reciprocal interactions between the tropics and the midlatitudes on the submonthly and MJO timescales in both the composites and the case study involve pressure surges and wave interaction that influence subsequent convection as the convective envelope migrates eastward from the tropical Indian to Pacific Ocean region. C1 UNIV NEW MEXICO, ALBUQUERQUE, NM 87106 USA. NOAA, AERON LAB, BOULDER, CO 80303 USA. CLIMATE DIAGNOST CTR, BOULDER, CO 80303 USA. UNIV COLORADO, PROGRAM ATMOSPHER & OCEAN SCI, BOULDER, CO 80302 USA. RP Meehl, GA (reprint author), NATL CTR ATMOSPHER RES, POB 3000, 1850 TABLE MESA DR, BOULDER, CO 80307 USA. RI Wheeler, Matthew/C-9038-2011; OI Wheeler, Matthew/0000-0002-9769-1973; COMPO, GILBERT/0000-0001-5199-9633 NR 49 TC 50 Z9 50 U1 1 U2 10 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 2169-897X J9 J GEOPHYS RES-ATMOS JI J. Geophys. Res.-Atmos. PD JUN 27 PY 1996 VL 101 IS D10 BP 15033 EP 15049 DI 10.1029/96JD01014 PG 17 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA UV948 UT WOS:A1996UV94800006 ER PT J AU Williams, CR Avery, SK AF Williams, CR Avery, SK TI Diurnal winds observed in the tropical troposphere using 50 MHz wind profilers SO JOURNAL OF GEOPHYSICAL RESEARCH-ATMOSPHERES LA English DT Article ID MIDDLE ATMOSPHERE; CHRISTMAS-ISLAND; GRAVITY-WAVE; TURBULENCE; PACIFIC; RADAR AB The seasonal diurnal zonal and meridional winds observed from 2 to 18 km in the tropical Pacific using five SP-R?Hz wind profilers are presented. The hourly data sets ranged in length from 686 days to 2934 days of observations. The observed diurnal winds are compared with tidal model winds forced by solar absorption of water vapor that are primarily the (1,1,1) tidal mode. Similarities between observed and modeled diurnal winds off the equator (12 degrees S) suggest these off-equator observations are forced by solar absorption of water vapor and are global oscillations. Differences between observed and modeled winds near the equator (2 degrees N and 1 degrees S) suggest these observations are forced by local or mesoscale processes. The vertical structure of meridional wind near the equator supports the diurnal forcing by the radiation of cloud tops and/or cirrus clouds above 12 km or the latent heat release of precipitating clouds extending throughout the troposphere. While near-equator observations appear to be locally forced, the global distribution of these ''local'' forcing mechanisms may generate global oscillations that cannot be resolved with these wind profiler data from the Pacific basin. The observed winds below 4 km appear to be affected by boundary layer processes and have different characteristics than winds above 4 km. C1 UNIV COLORADO, COOPERAT INST RES ENVIRONM SCI, BOULDER, CO 80309 USA. NOAA, AERON LAB, CIRES, BOULDER, CO 80303 USA. RI Williams, Christopher/A-2723-2015 OI Williams, Christopher/0000-0001-9394-8850 NR 20 TC 14 Z9 14 U1 2 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 JUN 27 PY 1996 VL 101 IS D10 BP 15051 EP 15060 DI 10.1029/96JD01013 PG 10 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA UV948 UT WOS:A1996UV94800007 ER PT J AU Gage, KS McAfee, JR Williams, CR AF Gage, KS McAfee, JR Williams, CR TI On the annual variation of tropospheric zonal winds observed above Christmas Island in the central equatorial Pacific SO JOURNAL OF GEOPHYSICAL RESEARCH-ATMOSPHERES LA English DT Article ID SOUTHERN OSCILLATION; INTERANNUAL VARIABILITY; TROPICAL PACIFIC; ANNUAL CYCLE; CLOUD CLUSTERS; CIRCULATION; TROPOPAUSE; ATMOSPHERE; PROFILER; HEIGHT AB Observations of tropospheric winds have been made nearly continuously since early 1986 in the altitude range 2-18 km using a 50 MHz VHF wind profiler at Christmas Island (2 degrees N, 157 degrees W). Tropospheric zonal winds observed at Christmas Island show a pronounced annual variation in the middle to upper troposphere with westerly winds typically observed during northern winter. The annual variation is strongest during La Nina and weakest during El Nino. The amplitude of the cycle has a broad peak in the upper troposphere. Empirical orthogonal function (EOF) analysis of the vertical structure of the annual variation shows that the principal mode explains nearly 90% of the variance in the 90- to 365-day frequency band. We attribute the annual variation in zonal winds to the annual variation in deep tropical heating associated with deep convection. The annual variation in tropical convection gives rise to annual variations in the surface pressure and pressure difference between Darwin and Tahiti. The pressure difference is greatest during northern hemisphere winter months. Other measures of the annual variation in tropical convection are provided by the tropical tropopause height and by highly reflective clouds (HRC). The tropical tropopause is highest during the northern hemisphere winter months when convection is most active over the maritime continent/western Pacific warm pool region and lowest in northern summer when convection is most active over the land masses of the northern hemisphere. The HRC show an annual migration in the centers of active convection. The annual latitudinal migration of the active centers of convection over the western Pacific with respect to the equatorial waveguide appears to be an important factor in determining the annual variation evident in the remote response of the zonal winds observed over Christmas Island. C1 UNIV COLORADO, COOPERAT INST RES ENVIRONM SCI, BOULDER, CO 80309 USA. NOAA, AERON LAB, ERL, CIRES, BOULDER, CO 80303 USA. RI Williams, Christopher/A-2723-2015 OI Williams, Christopher/0000-0001-9394-8850 NR 39 TC 20 Z9 20 U1 1 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 JUN 27 PY 1996 VL 101 IS D10 BP 15061 EP 15070 DI 10.1029/96JD00029 PG 10 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA UV948 UT WOS:A1996UV94800008 ER PT J AU Appenzeller, C Holton, JR Rosenlof, KH AF Appenzeller, C Holton, JR Rosenlof, KH TI Seasonal variation of mass transport across the tropopause SO JOURNAL OF GEOPHYSICAL RESEARCH-ATMOSPHERES LA English DT Article ID DIABATIC CIRCULATION; STRATOSPHERE AB The annual cycle of the net mass transport across the extratropical tropopause is examined. Contributions from both the global-scale meridional circulation and the mass variation of the lowermost stratosphere are included. For the northern hemisphere the mass of the lowermost stratosphere has a distinct annual cycle, whereas for the southern hemisphere, the corresponding variation is weak. The net mass transport across the tropopause in the northern hemisphere has a maximum in late spring and a distinct minimum in autumn. This variation and its magnitude compare well with older estimates based on representative Sr-90 mixing ratios. For the southern hemisphere the seasonal cycle of the net mass transport is weaker and follows roughly the annual variation of the net mass flux across a nearby isentropic surface. C1 UNIV COLORADO, NOAA, BOULDER, CO 80302 USA. RP Appenzeller, C (reprint author), UNIV WASHINGTON, DEPT ATMOSPHER SCI, BOX 351640, SEATTLE, WA 98195 USA. RI Appenzeller, Christof/B-3015-2013; Rosenlof, Karen/B-5652-2008 OI Appenzeller, Christof/0000-0002-9939-9845; Rosenlof, Karen/0000-0002-0903-8270 NR 28 TC 229 Z9 235 U1 2 U2 15 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 2169-897X J9 J GEOPHYS RES-ATMOS JI J. Geophys. Res.-Atmos. PD JUN 27 PY 1996 VL 101 IS D10 BP 15071 EP 15078 DI 10.1029/96JD00821 PG 8 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA UV948 UT WOS:A1996UV94800009 ER PT J AU Erickson, DJ Rasch, PJ Tans, PP Friedlingstein, P Ciais, P MaierReimer, E Six, K Fischer, CA Walters, S AF Erickson, DJ Rasch, PJ Tans, PP Friedlingstein, P Ciais, P MaierReimer, E Six, K Fischer, CA Walters, S TI The seasonal cycle of atmospheric CO2: A study based on the NCAR community climate model (CCM2) SO JOURNAL OF GEOPHYSICAL RESEARCH-ATMOSPHERES LA English DT Article ID SHAPE-PRESERVING INTERPOLATION; SEMI-LAGRANGIAN TRANSPORT; CARBON-DIOXIDE; GENERAL-CIRCULATION; MOISTURE TRANSPORT; OCEANIC UPTAKE; PACIFIC-OCEAN; EXCHANGE; BIOSPHERE; BUDGET AB A global three-dimensional atmospheric model, the NCAR CCM2 general circulation model, has been adapted to study the hourly to yearly variability of CO2 in the atmosphere. Features of this CCM2-based model include high spatial resolution (2.8 degrees x 2.8 degrees latitude/longitude), 18 vertical levels, a 15-min time step, and an explicit, nonlocal atmospheric boundary layer parameterization. The surface source/sink relationships used include exchange with the ocean, the terrestrial biosphere, biomass burning, and fossil fuel release of CO2. The timing and magnitude of the model seasonal cycle are compared to observational data for 28 sites. The seasonal cycle of atmospheric CO2 is generally well predicted by the model for most of the northern hemisphere, but estimates of the amplitude of the seasonal cycle in the southern hemisphere are overpredicted. To address this aspect more rigorously, we have used the monthly surface ocean pCO(2) maps created by the Max-Planck-Hamburg ocean general circulation model to asses the ocean seasonality on the atmospheric surface CO2 seasonality. The globally averaged interhemispheric gradient in atmospheric CO2 concentrations, as computed with the chosen source/sink distributions, is a factor of two too high compared to data, and selected longitudinal bands may be up to 50% higher than the zonal mean. The high temporal resolution of this model allows the infrequent yet real extrema in atmospheric CO2 concentrations to be captured. The vertical attenuation of the seasonal cycle of atmospheric CO2 is well simulated by the boundary layer/free troposphere interaction in the model in the northern hemisphere. Conversely, an increasing amplitude of the seasonal cycle aloft is found in the midlatitude southern hemisphere indicating interhemispheric transport effects from north to south. We use two different models of the terrestrial biosphere to examine the influence on the computed seasonal cycle and find appreciable differences, especially in continental sites. A global three-dimensional chemical transport model is used to assess the production of CO2 from the oxidation of CO throughout the volume of the atmosphere. We discuss these CO + OH --> CO2 + H results within the context of inverse model approaches to ascertaining the global and regional source/sink patterns of CO2. Deficiencies in the model output as compared to observational data are discussed within the context of guiding future research. C1 LMCE, GIF SUR YVETTE, FRANCE. BELGIAN INST SPACE AERON, BRUSSELS, BELGIUM. MAX PLANCK INST METEOROL, HAMBURG, GERMANY. NATL CTR ATMOSPHER RES, CLIMATE & GLOBAL DYNAM DIV, BOULDER, CO 80307 USA. NOAA, CLIMATE MONITORING & DIAGNOST LAB, BOULDER, CO 80303 USA. RP Erickson, DJ (reprint author), NATL CTR ATMOSPHER RES, DIV ATMOSPHER CHEM, POB 3000, BOULDER, CO 80307 USA. RI Friedlingstein, Pierre/H-2700-2014 NR 56 TC 28 Z9 28 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 JUN 27 PY 1996 VL 101 IS D10 BP 15079 EP 15097 DI 10.1029/95JD03680 PG 19 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA UV948 UT WOS:A1996UV94800010 ER PT J AU Booi, PAA Benz, SP AF Booi, PAA Benz, SP TI High power generation with distributed Josephson-junction arrays SO APPLIED PHYSICS LETTERS LA English DT Article AB We have experimentally coupled emission from a distributed series array of 1968 wide Josephson junctions to an on-chip 10.8 Ohm load and detected 0.16 mW at 240 GHz. This result is achieved by reducing the parasitic inductance associated with shunt resistors so that junctions with critical currents of 23 mA are effectively shunted at the operating frequency. This power is less than the 1.3 mW expected from theory due to the presence of a large impedance mismatch. Optimization of the load design will allow the detection of mW power. C1 NATL INST STAND & TECHNOL, BOULDER, CO 80303 USA. NR 17 TC 49 Z9 49 U1 0 U2 5 PU AMER INST PHYSICS PI MELVILLE PA CIRCULATION & FULFILLMENT DIV, 2 HUNTINGTON QUADRANGLE, STE 1 N O 1, MELVILLE, NY 11747-4501 USA SN 0003-6951 J9 APPL PHYS LETT JI Appl. Phys. Lett. PD JUN 24 PY 1996 VL 68 IS 26 BP 3799 EP 3801 DI 10.1063/1.116621 PG 3 WC Physics, Applied SC Physics GA UT481 UT WOS:A1996UT48100042 ER PT J AU Green, MA Prassides, K Day, P Stalick, JK AF Green, MA Prassides, K Day, P Stalick, JK TI Structural properties of A(2)SnO(4) (A=Ba,Sr) - A neutron diffraction study SO JOURNAL OF THE CHEMICAL SOCIETY-FARADAY TRANSACTIONS LA English DT Article ID SUPERCONDUCTIVITY; BA2PBO4; OXIDE AB The structural properties of the layered oxides Ba2SnO4 and Sr2SnO4 have been studied as a function of temperature by high resolution. powder neutron diffraction. As a result of excellent size matching between the SnO2 and Ba2O2 layers, Ba2SnO4 adopts the tetragonal K2NiF4 structure (space group I4/mmm) and undergoes no structural phase transition on cooling. Sr2SnO4, on the other hand, is orthorhombically distorted, (b - a)/(b + a) = 7.2(7) x 10(-4) at ambient temperature (space group Bmab) as a result of the co-operative rigid tilt of the corner-sharing SnO6 octahedra, which relieves the compressive stress of the SnO2 layers. Upon cooling, it undergoes a phase transition to a primitive tetragonal phase (space group P4(2)/ncm) which is characterised by a different rotational mode of distortion. C1 UCL ROYAL INST GREAT BRITAIN, LONDON W1X 4BS, ENGLAND. UNIV SUSSEX, SCH CHEM & MOLEC SCI, BRIGHTON BN1 9QJ, E SUSSEX, ENGLAND. NIST, MAT SCI & ENGN LAB, GAITHERSBURG, MD 20899 USA. RI Prassides, Kosmas/C-9804-2009 NR 20 TC 11 Z9 11 U1 2 U2 18 PU ROYAL SOC CHEMISTRY PI CAMBRIDGE PA THOMAS GRAHAM HOUSE, SCIENCE PARK, MILTON RD, CAMBRIDGE CB4 0WF, CAMBS, ENGLAND SN 0956-5000 J9 J CHEM SOC FARADAY T JI J. Chem. Soc.-Faraday Trans. PD JUN 21 PY 1996 VL 92 IS 12 BP 2155 EP 2159 DI 10.1039/ft9969202155 PG 5 WC Chemistry, Physical; Physics, Atomic, Molecular & Chemical SC Chemistry; Physics GA UU877 UT WOS:A1996UU87700016 ER PT J AU Volk, CM Elkins, JW Fahey, DW Salawitch, RJ Dutton, GS Gilligan, JM Proffitt, MH Loewenstein, M Podolske, JR Minschwaner, K Margitan, JJ Chan, KR AF Volk, CM Elkins, JW Fahey, DW Salawitch, RJ Dutton, GS Gilligan, JM Proffitt, MH Loewenstein, M Podolske, JR Minschwaner, K Margitan, JJ Chan, KR TI Quantifying transport between the tropical and mid-latitude lower stratosphere SO SCIENCE LA English DT Article ID MOUNT-PINATUBO; INSITU MEASUREMENTS; OZONE DEPLETION; AEROSOL; N2O; CONSTITUENTS; SIMULATIONS; ABSORPTION; CF2CL2; CFCL3 AB Airborne in situ observations of molecules with a wide range of lifetimes (methane, nitrous oxide, reactive nitrogen, ozone, chlorinated halocarbons, and halon-1211), used in a tropical tracer model, show that mid-latitude air is entrained into the tropical lower stratosphere within about 13.5 months; transport is faster in the reverse direction, Because exchange with the tropics is slower than global photochemical models generally assume, ozone at mid-latitudes appears to be more sensitive to elevated levels of industrial chlorine than is currently predicted, Nevertheless, about 45 percent of air in the tropical ascent region at 21 kilometers is of mid-latitude origin, implying that emissions from supersonic aircraft could reach the middle stratosphere. C1 UNIV COLORADO,COOPERAT INST RES ENVIRONM SCI,BOULDER,CO 80309. NOAA,AERON LAB,BOULDER,CO 80303. CALTECH,JET PROP LAB,PASADENA,CA 91109. NASA,AMES RES CTR,MOFFETT FIELD,CA 94035. NEW MEXICO INST MIN & TECHNOL,DEPT PHYS,SOCORRO,NM 87801. RP Volk, CM (reprint author), NOAA,CLIMATE MONITORING & DIAGNOST LAB,BOULDER,CO 80303, USA. RI Salawitch, Ross/B-4605-2009; Gilligan, Jonathan/I-8938-2014; Fahey, David/G-4499-2013 OI Salawitch, Ross/0000-0001-8597-5832; Gilligan, Jonathan/0000-0003-1375-6686; Fahey, David/0000-0003-1720-0634 NR 50 TC 129 Z9 129 U1 0 U2 11 PU AMER ASSOC ADVANCEMENT SCIENCE PI WASHINGTON PA 1200 NEW YORK AVE, NW, WASHINGTON, DC 20005 SN 0036-8075 J9 SCIENCE JI Science PD JUN 21 PY 1996 VL 272 IS 5269 BP 1763 EP 1768 DI 10.1126/science.272.5269.1763 PG 6 WC Multidisciplinary Sciences SC Science & Technology - Other Topics GA UT110 UT WOS:A1996UT11000035 ER PT J AU Wurman, J Straka, JM Rasmussen, EN AF Wurman, J Straka, JM Rasmussen, EN TI Fine-scale Doppler radar observations of tornadoes SO SCIENCE LA English DT Article AB Observations obtained with a mobile pencil-beam Doppler radar revealed many previously unresolved structures within tornadic storms and tornadoes and helped verify various aspects of conceptual models. Radar data from the parent circulations indicate the existence of spiral reflectivity bands, intense radial wind shear zones, and multiple larger-scale velocity maxima. Tornado structures observed include debris shields, clear axial (eye) regions, multiple reflectivity bands surrounding the center of the eye, and occasional reflectivity protrusions into the eye. Velocity and reflectivity data from tornado-scale circulations show evidence of axial downdrafts. C1 UNIV OKLAHOMA,COOPERAT INST MESOSCALE METEOROL STUDIES,NORMAN,OK 73019. NATL SEVERE STORMS LAB,NORMAN,OK 73069. RP Wurman, J (reprint author), UNIV OKLAHOMA,SCH METEOROL,CTR ANAL & PREDICT STORMS,100 E BOYD ST,NORMAN,OK 73019, USA. NR 12 TC 75 Z9 76 U1 0 U2 1 PU AMER ASSOC ADVANCEMENT SCIENCE PI WASHINGTON PA 1200 NEW YORK AVE, NW, WASHINGTON, DC 20005 SN 0036-8075 J9 SCIENCE JI Science PD JUN 21 PY 1996 VL 272 IS 5269 BP 1774 EP 1777 DI 10.1126/science.272.5269.1774 PG 4 WC Multidisciplinary Sciences SC Science & Technology - Other Topics GA UT110 UT WOS:A1996UT11000038 ER PT J AU Brown, JM Evenson, KM Zink, LR Vasconcellos, ECC AF Brown, JM Evenson, KM Zink, LR Vasconcellos, ECC TI Laser magnetic resonance measurement of the P-3(1)-P-3(0) fine-structure separation of P+ SO ASTROPHYSICAL JOURNAL LA English DT Article DE atomic data ID INTERSTELLAR PN; PHOSPHORUS AB The far-infrared laser magnetic resonance spectrum associated with the J = 1 <-- 0 fine-structure transition of P-31(+) in its ground P-3 State has been recorded. This is the first laboratory observation of this magnetic dipole transition, and its frequency has been measured 2 orders of magnitude more accurately than the previous, indirect determination from optical spectroscopy. The frequency is Delta E(10) = 4944433.0 +/- 1.7 MHz. A small nuclear hyperfine splitting was also observed for the J = 1 level. C1 NATL INST STAND & TECHNOL,DIV TIME & FREQUENCY,BOULDER,CO 80303. UNIV ESTADUAL CAMPINAS,INST FIS GLEB WATAGHIN,DEPT ELECT QUANT,BR-13083970 CAMPINAS,SP,BRAZIL. RP Brown, JM (reprint author), UNIV OXFORD,PHYS & THEORET CHEM LAB,S PARKS RD,OXFORD OX1 3QZ,ENGLAND. RI Inst. of Physics, Gleb Wataghin/A-9780-2017 NR 18 TC 2 Z9 2 U1 0 U2 1 PU UNIV CHICAGO PRESS PI CHICAGO PA 5720 S WOODLAWN AVE, CHICAGO, IL 60637 SN 0004-637X J9 ASTROPHYS J JI Astrophys. J. PD JUN 20 PY 1996 VL 464 IS 2 BP L203 EP L206 DI 10.1086/310101 PN 2 PG 4 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA UQ195 UT WOS:A1996UQ19500026 ER PT J AU Gemery, PA Trolier, M White, JWC AF Gemery, PA Trolier, M White, JWC TI Oxygen isotope exchange between carbon dioxide and water following atmospheric sampling using glass flasks SO JOURNAL OF GEOPHYSICAL RESEARCH-ATMOSPHERES LA English DT Article ID SECULAR VARIATIONS; CO2; FRACTIONATION; ABUNDANCE; RATIOS AB Measurements of the O-18/O-16 isotopic ratio of atmospheric carbon dioxide made by the University of Colorado, Boulder on flask samples provided by the Climate Monitoring and Diagnostics Laboratory of the National Oceanic and Atmospheric Administration appear to have been contaminated by oxygen isotope exchange between CO2 and water inside the glass flasks. The O-18/O-16 ratios measured for samples from high-humidity sites collected during 1990-1993 show considerable scatter and are believed not to represent the true oxygen isotopic composition of atmospheric CO2. Laboratory experiments have demonstrated that oxygen isotope exchange occurs between CO2 and water condensed on the flask walls. Complete isotopic equilibrium is not observed, even for storage times greater than 1 month; the extent of exchange differs for individual flasks. The experiments show that air samples to be stored in glass flasks must be dried to a dew point of 2 degrees C or lower before storage to eliminate artifacts associated with oxygen exchange. C1 NOAA, CLIMATE MONITORING & DIAGNOST LAB, BOULDER, CO 80303 USA. UNIV COLORADO, DEPT GEOL SCI, BOULDER, CO 80309 USA. UNIV COLORADO, INST ARCTIC & ALPINE RES, BOULDER, CO 80309 USA. RI White, James/A-7845-2009 OI White, James/0000-0001-6041-4684 NR 17 TC 33 Z9 33 U1 0 U2 11 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 2169-897X J9 J GEOPHYS RES-ATMOS JI J. Geophys. Res.-Atmos. PD JUN 20 PY 1996 VL 101 IS D9 BP 14415 EP 14420 DI 10.1029/96JD00053 PG 6 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA UT467 UT WOS:A1996UT46700005 ER PT J AU Beyer, KD Ravishankara, AR Lovejoy, ER AF Beyer, KD Ravishankara, AR Lovejoy, ER TI Measurements of UV refractive indices and densities of H2SO4/H2O and H2SO4/HNO3/H2O solutions SO JOURNAL OF GEOPHYSICAL RESEARCH-ATMOSPHERES LA English DT Article ID SULFURIC-ACID; SULFATE AEROSOLS; CLOUDS AB Refractive indices of aqueous solutions of sulfuric acid and sulfuric acid/nitric acid were measured at 365, 313, 308, 254, and 214 nm at 298 K. The solution concentrations were H2SO4/H2O: 88.6, 78.7, 63.0, 52.3, 39.8 wt % SA (sulfuric acid); H2SO4/HNO3/H2O: 50.3 SA 2.5 NA (nitric acid), 45.4 SA 5.1 NA, 41.9 SA 7.4 NA, 37.9 SA 10.4 NA wt %. Densities of the solutions were also measured at low temperatures in order to calculate the refractive indices of these solutions at stratospheric temperatures. C1 NOAA, AERON LAB, BOULDER, CO 80303 USA. RI Ravishankara, Akkihebbal/A-2914-2011 NR 36 TC 23 Z9 23 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 JUN 20 PY 1996 VL 101 IS D9 BP 14519 EP 14524 DI 10.1029/96JD00937 PG 6 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA UT467 UT WOS:A1996UT46700015 ER PT J AU Oltmans, SJ Hofmann, DJ Lathrop, JA Harris, JM Komhyr, WD Kuniyuki, D AF Oltmans, SJ Hofmann, DJ Lathrop, JA Harris, JM Komhyr, WD Kuniyuki, D TI Tropospheric ozone during Mauna Loa observatory photochemistry experiment 2 compared to long-term measurements from surface and ozonesonde observations SO JOURNAL OF GEOPHYSICAL RESEARCH-ATMOSPHERES LA English DT Article AB Continuous surface ozone measurements have been made at Mama Loa Observatory (MLO) for 20 years. In addition, weekly ozone profile measurements using balloonborne ozonesondes have been carried out from Hilo, Hawaii, since 1985. These long-term records are compared with data obtained during the MLOPEX 2 period from September 1991 to August 1992. Ozone behavior at the observatory level (similar to 3.4 km) during autumn and winter of 1991-1992 was similar to that found during the period 1980-1990. In spring and summer 1992, however, there were several significant differences from the long-term behavior. During March and April 1992, there was about 10% more ozone than the long-term average, and the variability was less than half of what is seen normally. These characteristics are associated with strong flow from the north and west. Both June and July 1992 saw periods of elevated ozone with the June average 20% higher than normal. During the more limited sampling (weekly profiles) when ozonesonde measurements were made, the 1992 spring enhancement was particularly pronounced at 500 mbar (similar to 6 km), while during the summer the larger than normal concentrations were at 700 mbar (similar to 3.5 km). In the upper troposphere, on the other hand, spring ozone amounts in 1992 were much below normal with only about half the ozone usually seen in the 12- to 15-km region. The ozone profiles are discussed in terms of the representativeness of the MLO surface measurements in characterizing the free troposphere ozone behavior at both the altitude of the observatory as well as other heights in the atmosphere. During the winter and spring, the MLO measurements are often representative of behavior over a broad depth of the troposphere (3-10 km). In the summer and autumn the MLO observations are more characteristic of free tropospheric conditions at or near the observatory level. C1 UNIV COLORADO, COOPERAT INST RES ENVIRONM SCI, BOULDER, CO 80309 USA. NOAA, CMDL, US DEPT COMMERCE, MAUNA LOA OBSERV, HILO, HI 96720 USA. RP Oltmans, SJ (reprint author), NOAA, CLIMATE MONITORING & DIAGNOST LAB, US DEPT COMMERCE, RECGI, 325 BROADWAY, BOULDER, CO 80303 USA. NR 14 TC 30 Z9 30 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 JUN 20 PY 1996 VL 101 IS D9 BP 14569 EP 14580 DI 10.1029/95JD03004 PG 12 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA UT467 UT WOS:A1996UT46700019 ER PT J AU Atlas, E Ridley, B Walega, J Greenberg, J Kok, G Staffelbach, T Schauffler, S Lind, J Hubler, G Norton, R Liu, S Davis, D Bandy, A Blake, D Bradshaw, J Browell, E Collins, JE Gregory, G Heikes, B Kondo, Y Sachse, G Sandholm, S Singh, H Talbot, B Dlugokencky, E Elkins, J Oltmans, S Mackay, G Karecki, D AF Atlas, E Ridley, B Walega, J Greenberg, J Kok, G Staffelbach, T Schauffler, S Lind, J Hubler, G Norton, R Liu, S Davis, D Bandy, A Blake, D Bradshaw, J Browell, E Collins, JE Gregory, G Heikes, B Kondo, Y Sachse, G Sandholm, S Singh, H Talbot, B Dlugokencky, E Elkins, J Oltmans, S Mackay, G Karecki, D TI A comparison of aircraft and ground-based measurements at Mauna Loa observatory, Hawaii, during GTE PEM-west and MLOPEX 2 SO JOURNAL OF GEOPHYSICAL RESEARCH-ATMOSPHERES LA English DT Article ID PHOTOCHEMISTRY EXPERIMENT; AIRBORNE MEASUREMENTS; HYDROGEN-PEROXIDE; NITROGEN-DIOXIDE; NITRIC-OXIDE; NITRATE; OZONE; NOY; INSTRUMENT; BUDGET AB During October 19-20, 1991, one flight of the NASA Global Tropospheric Experiment (GTE) Pacific Exploratory Mission (PEM-West A) mission was conducted near Hawaii as an intercomparison with ground-based measurements of the Mauna Loa Observatory Photochemistry Experiment (MLOPEX 2) and the NOAA Climate Modeling and Diagnostics Laboratory (CMDL). Ozone, reactive nitrogen species, peroxides, hydrocarbons, and halogenated hydrocarbons were measured by investigators aboard the DC-8 aircraft and at the ground site. Lidar cross sections of ozone revealed a complex air mass structure near the island of Hawaii which was evidenced by large variation in some trace gas mixing ratios. This variation limited the time and spatial scales for direct measurement intercomparisons. Where differences occurred between measurements in the same air masses, the intercomparison suggested that biases for some trace gases was due to different calibration scales or, in some cases, instrumental or sampling biases. Relatively large uncertainties were associated with those trace gases present in the low parts per trillion by volume range. Trace gas correlations were used to expand the scope of the intercomparison to identify consistent trends between the different data sets. C1 DREXEL UNIV, DEPT CHEM, PHILADELPHIA, PA 19104 USA. UNIV CALIF IRVINE, DEPT CHEM, IRVINE, CA 92717 USA. GEORGIA INST TECHNOL, ATLANTA, GA 30332 USA. NASA, LANGLEY RES CTR, HAMPTON, VA 23681 USA. NOAA, CLIMATE MONITORING & DIAGNOST LAB, BOULDER, CO 80303 USA. UNIV RHODE ISL, GRAD SCH OCEANOG, NARRAGANSETT, RI 02882 USA. NOAA, AERON LAB, BOULDER, CO 80303 USA. UNISEARCH ASSOCIATES, CONCORD, ON L4K 1B5, CANADA. NAGOYA UNIV, SOLAR TERR ENVIRONM LAB, TOYOKAWA, AICHI 442, JAPAN. NASA, AMES RES CTR, MOFFETT FIELD, CA 94035 USA. UNIV NEW HAMPSHIRE, COMPLEX SYST RES CTR, INST EARTH OCEANS & SPACE, DURHAM, NH 03824 USA. RP Atlas, E (reprint author), NATL CTR ATMOSPHER RES, POB 3000, BOULDER, CO 80307 USA. RI Hubler, Gerhard/E-9780-2010; Kondo, Yutaka/D-1459-2012; Atlas, Elliot/J-8171-2015 NR 41 TC 7 Z9 7 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 JUN 20 PY 1996 VL 101 IS D9 BP 14599 EP 14612 DI 10.1029/96JD00213 PG 14 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA UT467 UT WOS:A1996UT46700021 ER PT J AU Hauglustaine, DA Madronich, S Ridley, BA Walega, JG Cantrell, CA Shetter, RE Hubler, G AF Hauglustaine, DA Madronich, S Ridley, BA Walega, JG Cantrell, CA Shetter, RE Hubler, G TI Observed and model-calculated photostationary state at Mauna Loa observatory during MLOPEX 2 SO JOURNAL OF GEOPHYSICAL RESEARCH-ATMOSPHERES LA English DT Article ID PHOTOCHEMISTRY EXPERIMENT; RADIOMETER MEASUREMENTS; PEROXY-RADICALS; OZONE; DEVIATIONS; IODINE; SITE AB During the Mauna Loa Observatory Photochemistry Experiment (MLOPEX 2), simultaneous clear sky measurements of [NO2], [NO], [O-3], and NO2 photodissociation rate were collected during autumn 1991, winter, spring, and summer 1992 intensive measurement periods at Mauna Loa Observatory (MLO), Hawaii. These measurements were used to assess the O-3-NO-NO2 photostationary state, and to infer peroxy radical concentration, ozone photochemical production and destruction rates, as well as the relationship between the deviation of the photostationary state parameter, phi = j(2)[NO2]/k(1)[O-3][NO], from unity and environmental variables. In addition, a photochemical box model was used for the purpose of comparison with observations and interpretation of the results. A systematic deviation of phi from unity was determined from measurements, this parameter reached values of 1.5-2 for high-sun conditions depending on the season. The inferred total peroxy radical concentrations were generally larger (25-70 pptv for high-sun conditions depending on the season) than those directly measured (20-25 pptv during noontime). Model results seem generally to underestimate the value of phi and to overpredict the hydroxyl and total peroxy radical concentrations, suggesting loss processes not accounted for in the model for these species. Analysis of the contributions to the net ozone photochemical production indicates total production and destruction terms reaching 10-15 ppbv/day which tend to nearly cancel on a daily average basis. High-sun values of phi - 1 were shown to be independent of NOx (= NO + NO2) for NOx concentrations above about 50 pptv. However, below this level, observations show that phi - 1 generally decreases with increasing nitrogen oxide concentrations. Furthermore, the measured phi - 1 correlation with root H2O]/[O-3] suggests the existence of NO to NO2 oxidants not accounted for in a simplified HOx chemistry. C1 NOAA, AERON LAB, BOULDER, CO 80303 USA. CNRS, SERV AERON, PARIS, FRANCE. RP Hauglustaine, DA (reprint author), NATL CTR ATMOSPHER RES, DIV ATMOSPHER CHEM, POB 3000, BOULDER, CO 80307 USA. RI Hubler, Gerhard/E-9780-2010; Madronich, Sasha/D-3284-2015 OI Madronich, Sasha/0000-0003-0983-1313 NR 33 TC 45 Z9 46 U1 0 U2 6 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 2169-897X J9 J GEOPHYS RES-ATMOS JI J. Geophys. Res.-Atmos. PD JUN 20 PY 1996 VL 101 IS D9 BP 14681 EP 14696 DI 10.1029/95JD03612 PG 16 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA UT467 UT WOS:A1996UT46700027 ER PT J AU Bodhaine, BA AF Bodhaine, BA TI Aerosol measurements during the Mauna Loa photochemistry experiment 2 SO JOURNAL OF GEOPHYSICAL RESEARCH-ATMOSPHERES LA English DT Article ID LONG-RANGE TRANSPORT; HAWAIIAN-ISLANDS; ASIAN DUST; CLIMATOLOGY; TRAJECTORIES AB Aerosol measurements have been made continuously at Mauna Loa Observatory (MLO) from 1974 to the present. Condensation nucleus (CN) concentration has been measured using automatic CN counters, and aerosol scattering extinction (sigma(sp)) has been measured using a four-wavelength nephelometer. The Mauna Loa Observatory Photochemistry Experiment (MLOPEX) was conducted in 1991-1992 to study intensively many important variables in the field of atmospheric chemistry. Because of a strong diurnal cycle in nearly everything measured at MLO caused by an upslope-downslope wind system, it is important to develop data-editing criteria that can safely identify background conditions as opposed to other conditions when the site may be contaminated by local sources. Ordinarily, background conditions occur during nighttime downslope wind conditions, and contaminated conditions occur during daytime upslope wind conditions. However, occasionally unusual weather conditions or contamination caused by a local source such as the Mauna Loa caldera can confuse the issue. It is recommended that background aerosol data be chosen during 0000-0800 Hawaiian standard time (HST) to generally avoid upslope wind conditions, and that wind direction and speed, CN, and SO2 data be used if available to further eliminate local pollution episodes. In addition, all data should be examined by a human editor, if possible, in order to recognize certain episodes that may not fit automated criteria. RP Bodhaine, BA (reprint author), NOAA, CLIMATE MONITORING & DIAGNOST LAB, R-E-CGI, 325 BROADWAY, BOULDER, CO 80303 USA. NR 27 TC 21 Z9 22 U1 2 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 JUN 20 PY 1996 VL 101 IS D9 BP 14757 EP 14765 DI 10.1029/95JD02045 PG 9 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA UT467 UT WOS:A1996UT46700033 ER PT J AU Eckert, J Nicol, JM Howard, J Trouw, FR AF Eckert, J Nicol, JM Howard, J Trouw, FR TI Adsorption of hydrogen in Ca-exchanged Na-A zeolites probed by inelastic neutron scattering spectroscopy SO JOURNAL OF PHYSICAL CHEMISTRY LA English DT Article ID MOLECULAR-HYDROGEN; CRYSTAL-STRUCTURE; ROTATION; COMPLEXES; GRAPHITE; BARRIER; H2; HD; DIFFUSIVITY; DIHYDROGEN AB The hindered rotations and vibrations of molecular hydrogen, deuterium, and deuterium hydride adsorbed into partially and fully Ca ion exchanged Na-A zeolites have been studied at low temperatures with the use of inelastic neutron scattering (INS) techniques. A loading of one molecule per supercage was used in an attempt to avoid multiple site occupancies. Nonetheless, the INS spectra of the rotational transitions of H-2, HD, and D-2 clearly show that physical adsorption occurs on several different sites. Both the CaNa-A and Ca-A samples have strong rotational bands near 6 meV. On this basis, we conclude that the principal adsorption site in CaNa-A is in the vicinity of the Ca2+ cation where H-2 experiences a rotational barrier of about 4.3 kJ/mol. C1 LOS ALAMOS NATL LAB,LANSCE,LOS ALAMOS,NM 87545. NATL INST STAND & TECHNOL,DIV REACTOR RADIAT,GAITHERSBURG,MD 20899. ICI FILMS,DUMFRIES DG2 8NE,SCOTLAND. ARGONNE NATL LAB,IPNS,ARGONNE,IL 60439. RP Eckert, J (reprint author), LOS ALAMOS NATL LAB,CATALYSIS CTR,MS H805,LOS ALAMOS,NM 87545, USA. RI Lujan Center, LANL/G-4896-2012 NR 31 TC 39 Z9 39 U1 1 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 JUN 20 PY 1996 VL 100 IS 25 BP 10646 EP 10651 DI 10.1021/jp952982d PG 6 WC Chemistry, Physical SC Chemistry GA UT213 UT WOS:A1996UT21300022 ER PT J AU Antosiewicz, J McCammon, JA Gilson, MK AF Antosiewicz, J McCammon, JA Gilson, MK TI The determinants of pK(a)s in proteins SO BIOCHEMISTRY LA English DT Article ID NUCLEAR-MAGNETIC-RESONANCE; PANCREATIC TRYPSIN-INHIBITOR; POISSON-BOLTZMANN EQUATION; SINGLE SALT BRIDGE; RIBONUCLEASE-A; ALPHA-CHYMOTRYPSIN; IONIZABLE GROUPS; ELECTROSTATIC CALCULATIONS; DIELECTRIC-PROPERTIES; NEUTRON-DIFFRACTION AB Although validation studies show that theoretical models for predicting the pK(a)s of ionizable groups in proteins are increasingly accurate, a number of important questions remain: (1) What factors limit the accuracy of current models? (2) How can conformational flexibility of proteins best be accounted for? (3) Will use of solution structures in the calculations, rather than crystal structures, improve the accuracy of the computed pK(a)s? and (4) Why does accurate prediction of protein pK(a)s seem to require that a high dielectric constant be assigned to the protein interior? This paper addresses these and related issues. Among the conclusions are the following: (1) computed pK(a)s averaged over NMR structure sets are more accurate than those based upon single crystal structures; (2) use of atomic parameters optimized to reproduce hydration energies of small molecules improves agreement with experiment when a low protein dielectric constant is assumed; (3) despite use of NMR structures and optimized atomic parameters, pK(a)s computed with a protein dielectric constant of 20 are more accurate than those computed with a low protein dielectric constant; (4) the pK(a) shifts in ribonuclease A that result from phosphate binding are reproduced reasonably well by calculations; (5) the substantial pK(a) shifts observed in turkey ovomucoid third domain result largely from interactions among ionized groups; and (6) both experimental data and calculations indicate that proteins tend to lower the pK(a)s of Asp side chains but have little overall effect upon the pK(a)s of other ionizable groups. C1 NIST, CTR ADV RES BIOTECHNOL, ROCKVILLE, MD 20850 USA. UNIV CALIF SAN DIEGO, DEPT CHEM & BIOCHEM, LA JOLLA, CA 92093 USA. UNIV CALIF SAN DIEGO, DEPT PHARMACOL, LA JOLLA, CA 92093 USA. RI Antosiewicz, Jan/G-1308-2011 NR 86 TC 387 Z9 391 U1 0 U2 29 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 0006-2960 J9 BIOCHEMISTRY-US JI Biochemistry PD JUN 18 PY 1996 VL 35 IS 24 BP 7819 EP 7833 DI 10.1021/bi9601565 PG 15 WC Biochemistry & Molecular Biology SC Biochemistry & Molecular Biology GA UR904 UT WOS:A1996UR90400023 PM 8672483 ER PT J AU Gupta, R McClelland, JJ Marte, P Celotta, RJ AF Gupta, R McClelland, JJ Marte, P Celotta, RJ TI Raman-induced avoided crossings in adiabatic optical potentials: Observation of lambda/8 spatial frequency in the distribution of atoms SO PHYSICAL REVIEW LETTERS LA English DT Article ID RESONANCE FLUORESCENCE; WAVE; SIMULATION; DYNAMICS; SPECTRUM; MOLASSES AB Chromium atoms traverse an optical potential and the resulting spatial distribution is measured by a new method. Atoms are collected on a substrate and an atomic force microscope is used to determine the flux as a function of position. An unexpectedly high spatial frequency (lambda/8) is found in the atomic distribution. This is attributed to avoided crossings arising from Raman coherences induced between magnetic sublevels. These results show that level crossings and nonadiabatic transitions can play an important role in the manipulation of atomic trajectories by near-resonant light fields. C1 HARVARD UNIV,DEPT PHYS,CAMBRIDGE,MA 02138. RP Gupta, R (reprint author), NATL INST STAND & TECHNOL,ELECTRON PHYS GRP,GAITHERSBURG,MD 20899, USA. RI McClelland, Jabez/A-2358-2015 OI McClelland, Jabez/0000-0001-5672-5965 NR 23 TC 59 Z9 61 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 JUN 17 PY 1996 VL 76 IS 25 BP 4689 EP 4692 DI 10.1103/PhysRevLett.76.4689 PG 4 WC Physics, Multidisciplinary SC Physics GA UR095 UT WOS:A1996UR09500010 ER PT J AU Cannon, GA Thomson, RE AF Cannon, GA Thomson, RE TI Characteristics of 4-day oscillations trapped by the Juan de Fuca Ridge SO GEOPHYSICAL RESEARCH LETTERS LA English DT Article ID HYDROTHERMAL PLUMES; MOTIONS AB Current meter observations from different studies along the crest of the juan de Fuca Ridge have been combined to show new features of the relatively large, broad spectral peak centered near a period of about 4 days. The coherence range of the 4-day oscillations has been extended to the extreme ends of the ridge, and the trapped waves appear to propagate northward along the entire length of the ridge at about 1 m/s. Spectral amplitudes are about double on the south end compared to the north end, and a recent model for bottom-trapped subinertial waves over topography shows this may be due to variations in ridge width [Allen and Thomson, 1993]. New observations show coherence between temperatures and currents near the South Cleft vent field and suggest 4-day oscillations can play a major role in the local advection of hydrothermal plumes. These observations combined with earlier results demonstrate that 4-day oscillations are a significant ridge-trapped feature, and they suggest that other ridges may be important in transmitting energy over much longer distances. C1 FISHERIES & OCEANS CANADA INST OCEAN SCI, SIDNEY, BC V8L 4B2, CANADA. RP NOAA, PACIFIC MARINE ENVIRONM LAB, 7600 SAND POINT WAY NE, SEATTLE, WA 98115 USA. NR 12 TC 19 Z9 19 U1 0 U2 0 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 0094-8276 EI 1944-8007 J9 GEOPHYS RES LETT JI Geophys. Res. Lett. PD JUN 15 PY 1996 VL 23 IS 13 BP 1613 EP 1616 DI 10.1029/96GL01370 PG 4 WC Geosciences, Multidisciplinary SC Geology GA UT009 UT WOS:A1996UT00900017 ER PT J AU Fahey, DW Donnelly, SG Keim, ER Gao, RS Wamsley, RC DelNegro, LA Woodbridge, EL Proffitt, MH Rosenlof, KH Ko, MKW Weisenstein, DK Scott, CJ Nevison, C Solomon, S Chan, KR AF Fahey, DW Donnelly, SG Keim, ER Gao, RS Wamsley, RC DelNegro, LA Woodbridge, EL Proffitt, MH Rosenlof, KH Ko, MKW Weisenstein, DK Scott, CJ Nevison, C Solomon, S Chan, KR TI In situ observations of NOy, O-3, and the NOy/O-3 ratio in the lower stratosphere SO GEOPHYSICAL RESEARCH LETTERS LA English DT Article ID MIDDLE ATMOSPHERE; OZONE; MODEL AB Extensive in situ measurements of reactive nitrogen (NOy) and ozone (O-3) were made in the lower stratosphere over a broad latitude range (60 degrees N-70 degrees S) during two different seasons (March and October) in 1994. Both NOy and O-3 mixing ratios show a strong latitude dependence, with values increasing toward the poles. The NOy/O-3 ratio reveals a high-gradient region near the tropics that is not well-represented in standard 2-D photochemical transport models. Improving the representation by changing the horizontal eddy-diffusion coefficients near the tropics has important implications for the predicted impacts of aircraft emissions on stratospheric O-3. C1 UNIV COLORADO,COOPERAT INST RES ENVIRONM SCI,BOULDER,CO 80309. UNIV COLORADO,DEPT CHEM & BIOCHEM,BOULDER,CO 80309. UNIV CALIF SAN DIEGO,SCRIPPS INST OCEANOG,CTR CLOUDS CLIMATE & CHEM,LA JOLLA,CA 92093. ATMOSPHER & ENVIRONM RES INC,CAMBRIDGE,MA 02139. NASA,AMES RES CTR,MOFFETT FIELD,CA 94035. RP Fahey, DW (reprint author), NOAA,AERON LAB,325 BROADWAY,BOULDER,CO 80303, USA. RI Gao, Ru-Shan/H-7455-2013; Rosenlof, Karen/B-5652-2008; Ko, Malcolm/D-5898-2015; Fahey, David/G-4499-2013 OI Rosenlof, Karen/0000-0002-0903-8270; Fahey, David/0000-0003-1720-0634 NR 19 TC 43 Z9 43 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 JUN 15 PY 1996 VL 23 IS 13 BP 1653 EP 1656 DI 10.1029/96GL01476 PG 4 WC Geosciences, Multidisciplinary SC Geology GA UT009 UT WOS:A1996UT00900027 ER PT J AU Hansen, J Ruedy, R Sato, M Reynolds, R AF Hansen, J Ruedy, R Sato, M Reynolds, R TI Global surface air temperature in 1995: Return to pre-Pinatubo level SO GEOPHYSICAL RESEARCH LETTERS LA English DT Article ID CLIMATE AB Global surface air temperature has increased about 0.5 degrees C from the minimum of mid-1992, a year after the Mt. Pinatubo eruption. Both a land-based surface air temperature record and a land-marine temperature index place the meteorological year 1995 at approximately the same level as 1990, previously the warmest year in the period of instrumental data. As El Nino warming was small in 1995, the solar cycle near a minimum, and ozone depletion near record levels, the observed high temperature supports the contention of an underlying global warming trend. The pattern of Northern Hemisphere temperature change in recent decades appears to reflect a change of atmospheric dynamics. C1 NOAA,NATL CTR ENVIRONM PREDICT,CAMP SPRINGS,MD 20746. RP Hansen, J (reprint author), NASA,GODDARD INST SPACE STUDIES,2880 BROADWAY,NEW YORK,NY 10025, USA. NR 28 TC 116 Z9 121 U1 2 U2 7 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 SN 0094-8276 J9 GEOPHYS RES LETT JI Geophys. Res. Lett. PD JUN 15 PY 1996 VL 23 IS 13 BP 1665 EP 1668 DI 10.1029/96GL01040 PG 4 WC Geosciences, Multidisciplinary SC Geology GA UT009 UT WOS:A1996UT00900030 ER PT J AU Landsea, CW Nicholls, N Gray, WM Avila, LA AF Landsea, CW Nicholls, N Gray, WM Avila, LA TI Downward trends in the frequency of intense Atlantic hurricanes during the past five decades SO GEOPHYSICAL RESEARCH LETTERS LA English DT Article ID STRONG ASSOCIATION; RAINFALL; CLIMATE; GCM AB There is concern that the enhanced greenhouse effect may be affecting extreme weather events such as tropical cyclones. The North Atlantic basin offers a reliable, long-term record of tropical cyclone activity, though it may not be representative of tropical cyclones throughout the rest of the tropics. The most recent years of 1991 through 1994 have experienced the quietest tropical cyclone activity on record in terms of frequency of tropical storms, hurricanes, and intense hurricanes. This was followed by the 1995 hurricane season, one of the busiest in the past 50 years. Despite 1995's activity, a long-term (five decade) downward trend continues to be evident primarily in the frequency of intense hurricanes. In addition, the mean maximum intensity (i.e., averaged over all cyclones in a season) has decreased, while the maximum intensity attained by the strongest hurricane each year has not shown a significant change. C1 COLORADO STATE UNIV,DEPT ATMOSPHER SCI,FT COLLINS,CO 80523. NATL HURRICANE CTR,MIAMI,FL 33165. BUR METEOROL RES CTR,MELBOURNE,VIC 3001,AUSTRALIA. RP Landsea, CW (reprint author), NOAA,ATLANTIC OCEANOG & METEOROL LAB,HURRICANE RES DIV,11691 SW 17TH ST,MIAMI,FL 33149, USA. RI Nicholls, Neville/A-1240-2008; Hamrin, Goran/C-3526-2014 OI Hamrin, Goran/0000-0003-4256-2960 NR 22 TC 112 Z9 116 U1 2 U2 16 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 SN 0094-8276 J9 GEOPHYS RES LETT JI Geophys. Res. Lett. PD JUN 15 PY 1996 VL 23 IS 13 BP 1697 EP 1700 DI 10.1029/96GL01029 PG 4 WC Geosciences, Multidisciplinary SC Geology GA UT009 UT WOS:A1996UT00900038 ER PT J AU Farrell, JT Suhm, MA Nesbitt, DJ AF Farrell, JT Suhm, MA Nesbitt, DJ TI Breaking symmetry with hydrogen bonds: Vibrational predissociation and isomerization dynamics in HF-DF and DF-HF isotopomers SO JOURNAL OF CHEMICAL PHYSICS LA English DT Article ID POTENTIAL-ENERGY SURFACES; FLUORIDE DIMER; STRETCHING FUNDAMENTALS; INFRARED-SPECTROSCOPY; HIGH-RESOLUTION; SLIT-JET; SPECTRA; (HF)2; COMPLEXES; ROTATION AB High-resolution near-IR spectra of jet-cooled HF-DF and DF-HF isotopomers are presented and analyzed for fundamental excitation in the HF-stretching region (3870 cm(-1)-3960 cm(-1)) and DF-stretching region (2840 cm(-1)-2880 cm(-1)), based on direct absorption of tunable IR difference frequency radiation in a slit-jet supersonic expansion (10 K). Spectra are obtained for excitation of all four stretching modes, *HF-DF, HF-*DF, *DF-HF, and DF-*HF (* denotes the vibrationally excited subunit), which probe both the hydrogen/deuterium bond donor and acceptor moieties in the complex. Vibrational redshifts and predissociation broadening measurements are compared with full 6D quantum calculations on theoretical HF dimer potential surfaces, which exhibit trends in qualitatively good agreement with experiment. Each of the three DF-stretch-excited bands are fit to spectroscopic precision (Delta v less than or similar to 0.0001 cm(-1)) by conventional high-resolution rotational analyses, cm whereas each of the four corresponding HF-stretch-excited bands appear extensively perturbed (Delta v approximate to 0.01 cm(-1)). This H/D isotope effect is interpreted as vibrational state mixing of the HF-stretch-excited species with a dense manifold of combination band states built on DF-stretch excitation, and therefore reflects intermolecular energy flow in the complex. Such vibrational stale mixing is further corroborated by observation of ''dark'' state transitions that can be tentatively assigned to *HF-DF isomer interacting with the nearly isoenergetic DF-*HF isomer. This state mixing would correspond to a vibrationally promoted ''isomerization'' over the tunneling barrier, and yield a spectroscopic measure of the difference in hydrogen bond dissociation energies [Delta D-0 = 74.7(5) cm(-1)] for the HF-DF and DF-HF isotopomers. (C) 1996 American Institute of Physics. C1 UNIV COLORADO,JOINT INST LAB ASTROPHYS,BOULDER,CO 80309. UNIV COLORADO,NATL INST STAND & TECHNOL,BOULDER,CO 80309. UNIV COLORADO,DEPT CHEM & BIOCHEM,BOULDER,CO 80309. RI Suhm, Martin/B-4740-2009 OI Suhm, Martin/0000-0001-8841-7705 NR 56 TC 27 Z9 27 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 JUN 15 PY 1996 VL 104 IS 23 BP 9313 EP 9331 DI 10.1063/1.471677 PG 19 WC Chemistry, Physical; Physics, Atomic, Molecular & Chemical SC Chemistry; Physics GA UQ672 UT WOS:A1996UQ67200006 ER PT J AU Merkle, G Bauer, BJ Han, CC AF Merkle, G Bauer, BJ Han, CC TI Relaxation after a temperature jump within the one-phase region of a polymer mixture SO JOURNAL OF CHEMICAL PHYSICS LA English DT Article ID ANGLE NEUTRON-SCATTERING; SPINODAL DECOMPOSITION; DYNAMICS; BLENDS; FLUCTUATIONS AB Small-angle neutron scattering was used to observe the relaxation of the structure factor from a smaller to a larger fluctuation state after a temperature jump within the one-phase region of a miscible polymer blend. The blend studied is a 60/40 by weight mixture of a hydrogen bonded polymer blend which consists of hydroxy modified deuterated polystyrene and poly(butylmethacrylate). A peak clearly evolved during the transition from the initial state at Ti to the final state at T-f as predicted by linear as well as nonlinear theories. This relaxation process, which took more than 10 h, could be represented reasonably well by a simple linear approximation of the Cahn-Hilliard-Cook (CHC) theory without involving nonlinear calculations for the evolution of the dynamic structure factor. The measurement offers an alternative method for estimating the order parameter relaxation rate in the one-phase region. Also, this demonstrates experimentally the correct relaxation (to a higher fluctuation state) mechanism predicted by the linear theory of CHC type. (C) 1996 American Institute of Physics. C1 NIST,DIV POLYMERS,GAITHERSBURG,MD 20899. NR 22 TC 5 Z9 5 U1 0 U2 1 PU AMER INST PHYSICS PI WOODBURY PA CIRCULATION FULFILLMENT DIV, 500 SUNNYSIDE BLVD, WOODBURY, NY 11797-2999 SN 0021-9606 J9 J CHEM PHYS JI J. Chem. Phys. PD JUN 15 PY 1996 VL 104 IS 23 BP 9647 EP 9650 DI 10.1063/1.471717 PG 4 WC Chemistry, Physical; Physics, Atomic, Molecular & Chemical SC Chemistry; Physics GA UQ672 UT WOS:A1996UQ67200040 ER PT J AU Carton, JA Giese, BS Cao, XH Miller, L AF Carton, JA Giese, BS Cao, XH Miller, L TI Impact of altimeter, thermistor, and expendable bathythermograph data on retrospective analyses of the tropical Pacific Ocean SO JOURNAL OF GEOPHYSICAL RESEARCH-OCEANS LA English DT Article ID DATA ASSIMILATION SYSTEM; SEA-LEVEL; MODEL; SPACE; TEMPERATURE; CIRCULATION; ATLANTIC; FIELDS AB This study explores the relative impact of three major components of the tropical Pacific Ocean observing system on data assimilation analyses. The extensive observing components that are available during the 2-year period from October 1992 through September 1994 include sea level derived from TOPEX/POSEIDON altimetry, thermistor data from the Tropical Ocean/Global Atmosphere Tropical Atmosphere-Ocean (TOGA TAO) mooring array, and expendable bathythermographs (XBTs) from the Volunteer Observing Ship program. In the first part of this study, methods are introduced to assimilate these data into a primitive equation model using optimal interpolation. The resulting velocity and thermal analyses are then compared with a numerical simulation that has no data assimilation. The most innovative aspect of the assimilation procedure is the development of a statistical model that uses satellite altimetry to update the subsurface thermal field. To determine the impact of individual components of the observing system, three additional experiments are conducted. In each experiment, one component is withheld from the assimilation. The resulting analysis is then compared with the missing data set. Our results show (1) To resolve major features of the seasonal cycle, it is necessary to have either the altimeter or the XBT data. In the absence of XBTs the analysis appears to develop a significant temporal drift in its thermal structure. (2) Intraseasonal variability such as tropical instability waves is best resolved using altimetry because of that data set's superior spatial resolution. (3) Thermistor data from the TOGA TAO mooring array are helpful, but not as crucial, in resolving the seasonal cycle within +/-8 degrees latitude as the XBTs. The mooring array is too coarsely spaced to allow this analysis system to resolve tropical instability waves. C1 TEXAS A&M UNIV,DEPT OCEANOG,COLLEGE STN,TX 77843. NOAA,GEOSCI LAB,SILVER SPRING,MD 20910. RP Carton, JA (reprint author), UNIV MARYLAND,DEPT METEOROL,COLLEGE PK,MD 20742, USA. RI carton, james/C-4807-2009; Miller, Laury/B-8305-2011 OI carton, james/0000-0003-0598-5198; Miller, Laury/0000-0003-3095-5804 NR 30 TC 37 Z9 40 U1 0 U2 1 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 SN 0148-0227 J9 J GEOPHYS RES-OCEANS JI J. Geophys. Res.-Oceans PD JUN 15 PY 1996 VL 101 IS C6 BP 14147 EP 14159 DI 10.1029/96JC00631 PG 13 WC Oceanography SC Oceanography GA UR422 UT WOS:A1996UR42200012 ER PT J AU Mahrt, L Vickers, D Howell, J Hojstrup, J Wilczak, JM Edson, J Hare, J AF Mahrt, L Vickers, D Howell, J Hojstrup, J Wilczak, JM Edson, J Hare, J TI Sea surface drag coefficients in the Riso Air Sea Experiment SO JOURNAL OF GEOPHYSICAL RESEARCH-OCEANS LA English DT Article ID WIND STRESS; GRAVITY-WAVES; HEAT-FLUX; OCEAN; DEPENDENCE; INTERFACE; ROUGHNESS AB This study examines the dependence of the computed drag coefficient on wind speed, stability, fetch, flux sampling problems, and method of calculation of the drag coefficient. The analysis is applied to data collected at a tower 2 km off the coast of Denmark during the Riso Air Sea Experiment (RASEX). Various flux sampling problems are evaluated to eliminate unreliable fluxes. Large drag coefficients are observed with weak large-scale flow. However, the value of the computed drag coefficient at weak wind speeds is sensitive to flux sampling problems and the method of calculation of the drag coefficient which might be a general characteristic of weak winds. The drag coefficient is significantly larger for short fetch conditions, particularly at strong wind speeds. C1 WOODS HOLE OCEANOG INST, WOODS HOLE, MA 02543 USA. RISO NATL LAB, DK-4000 ROSKILDE, DENMARK. NOAA, ENVIRONM RES LAB, ENVIRONM TECHNOL LAB, BOULDER, CO 80303 USA. RP OREGON STATE UNIV, COLL OCEAN & ATMOSPHER SCI, CORVALLIS, OR 97331 USA. NR 38 TC 47 Z9 48 U1 0 U2 6 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 2169-9275 EI 2169-9291 J9 J GEOPHYS RES-OCEANS JI J. Geophys. Res.-Oceans PD JUN 15 PY 1996 VL 101 IS C6 BP 14327 EP 14335 DI 10.1029/96JC00748 PG 9 WC Oceanography SC Oceanography GA UR422 UT WOS:A1996UR42200024 ER PT J AU Matsuya, S Takagi, S Chow, LC AF Matsuya, S Takagi, S Chow, LC TI Hydrolysis of tetracalcium phosphate in H3PO4 and KH2PO4 SO JOURNAL OF MATERIALS SCIENCE LA English DT Article ID HYDROXYAPATITE FORMATION; CERAMIC COMPOSITION; INVITRO BEHAVIOR; LOW-TEMPERATURE; CALCIUM; SOLUBILITY AB The activity product of tetracalcium phosphate (PTCP, Ca-4(PO4)(2)O), was determined at 37 degrees C, and the hydrolysis of TTCP was investigated in 0.01-0.1 mot l(-1) H3PO4 and KH2PO4 solutions by means of calcium and phosphorus analyses, X-ray diffraction and infrared analysis. The activity product, defined as K-sp=(Ca2+)(4) (PO43-)(2) (OH-)(2), was 37.36 as PKsp, which was smaller than that previously reported (42.4). TTCP easily hydrolysed to form calcium-deficient apatite (Ca-def OHAp, Ca-5-x(HPO4)(x)(PO4)(3-x)(OH)(1-x)), or dicalcium phosphate dihydrate (DCPD, CaHPO(4)2H(2)O), depending on the initial phosphate concentration. With 0.1 mol l(-1) H3PO4, TTCP hydrolysed to form DCPD within several minutes. In 0.025 mol l(-1) H3PO4 and 0.1 mol l(-1) KH2PO4, TTCP hydrolysed to form Ca-def OHAp through DCPD. In the latter solution, a small amount of octacalcium phosphate (OCP, Ca-8(H2PO4)(2)(PO4)(4)5H(2)O), was detected as an intermediate product. In 0.025 mol l(-1) KH2PO4, TTCP hydrolysed directly to form Ca-def OHAp. In 0.01 mol l(-1) H3PO4, hydrolysis of TTCP was not completed, although Ca-def OHAp was only a product. Thus the final product and the degree of hydrolysis depended on the pH and the overall Ca/P ratio in the reaction system. The rate of Ca-def OHAp formation seemed to be controlled by the dissolution rate of TTCP rather than the crystallization rate of the OHAp. C1 NIST,AMER DENT ASSOC HLTH FDN,PAFFENBARGER RES CTR,GAITHERSBURG,MD 20899. RP Matsuya, S (reprint author), KYUSHU UNIV,FAC DENT,DEPT DENT MAT ENGN,FUKUOKA 812,JAPAN. NR 22 TC 18 Z9 18 U1 0 U2 7 PU CHAPMAN HALL LTD PI LONDON PA 2-6 BOUNDARY ROW, LONDON, ENGLAND SE1 8HN SN 0022-2461 J9 J MATER SCI JI J. Mater. Sci. PD JUN 15 PY 1996 VL 31 IS 12 BP 3263 EP 3269 DI 10.1007/BF00354678 PG 7 WC Materials Science, Multidisciplinary SC Materials Science GA UV976 UT WOS:A1996UV97600031 ER PT J AU Woicik, JC Kendelewicz, T Yoshikawa, SA Miyano, KE Herman, GS Cowan, PL Pianetta, P Spicer, WE AF Woicik, JC Kendelewicz, T Yoshikawa, SA Miyano, KE Herman, GS Cowan, PL Pianetta, P Spicer, WE TI Surface-sensitive x-ray standing-wave study of Si(111)root 3x root 3-Ag SO PHYSICAL REVIEW B LA English DT Article ID SCANNING TUNNELING MICROSCOPY; SQUARE-ROOT-3-AG SURFACE; AG/SI(111) SURFACE; SI(111); DIFFRACTION; RECONSTRUCTION; AG; GROWTH; AES; NUCLEATION AB By combining the surface sensitivity of low-energy elastic photoelectrons with the position sensitivity of the x-ray standing-wave technique, we have determined both the Ag and Si atomic heights at the Si(lll)root 3x root 3-Ag interface. Our data give evidence that the Si(lll)root 3x root 3-Ag surface consists of a missing Si top-layer reconstruction, with Ag adatoms terminating the structure. The perpendicular height of the Ag layer and the first Si layer supports the honeycomb-chained-trimer model proposed for this interface. C1 STANFORD UNIV, STANFORD, CA 94305 USA. CUNY BROOKLYN COLL, BROOKLYN, NY 11210 USA. PACIFIC NW LAB, RICHLAND, WA 99352 USA. ARGONNE NATL LAB, CHICAGO, IL 60439 USA. RP Woicik, JC (reprint author), NIST, GAITHERSBURG, MD 20899 USA. NR 29 TC 6 Z9 6 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 JUN 15 PY 1996 VL 53 IS 23 BP 15425 EP 15428 DI 10.1103/PhysRevB.53.15425 PG 4 WC Physics, Condensed Matter SC Physics GA UT770 UT WOS:A1996UT77000013 ER PT J AU Mayewski, PA Twickler, MS Whitlow, SI Meeker, LD Yang, Q Thomas, J Kreutz, K Grootes, PM Morse, DL Steig, EJ Waddington, ED Saltzman, ES Whung, PY Taylor, KC AF Mayewski, PA Twickler, MS Whitlow, SI Meeker, LD Yang, Q Thomas, J Kreutz, K Grootes, PM Morse, DL Steig, EJ Waddington, ED Saltzman, ES Whung, PY Taylor, KC TI Climate change during the last deglaciation in Antarctica SO SCIENCE LA English DT Article ID SNOW ACCUMULATION; YOUNGER DRYAS; ATLANTIC; OCEAN; BP AB Greenland ice core records provide clear evidence of rapid changes in climate in a variety of climate indicators. In this work, rapid climate change events in the Northern and Southern hemispheres are compared on the basis of an examination of changes in atmospheric circulation developed from two ice cores. High-resolution glaciochemical series, covering the period 10,000 to 16,000 years ago, from a central Greenland ice core and anew site in east Antarctica display similar variability. These findings suggest that rapid climate change events occur more frequently in Antarctica than previously demonstrated. C1 UNIV NEW HAMPSHIRE, DEPT EARTH SCI, DURHAM, NH 03824 USA. UNIV NEW HAMPSHIRE, DEPT MATH, DURHAM, NH 03824 USA. UNIV WASHINGTON, QUATERNARY RES CTR AK60, SEATTLE, WA 98195 USA. UNIV WASHINGTON, GEOPHYS PROGRAM, SEATTLE, WA 98195 USA. UNIV MIAMI, ROSENSTIEL SCH MARINE & ATMOSPHER SCI, MIAMI, FL 33149 USA. UNIV MIAMI, NOAA, ATLANTIC OCEANOG & METEOROL LAB, OCEAN CHEM DIV, MIAMI, FL 33149 USA. UNIV & COMMUNITY COLL SYST NEVADA, DESERT RES INST, WATER RESOURCES CTR, RENO, NV 89506 USA. RP UNIV NEW HAMPSHIRE, INST STUDY EARTH OCEANS & SPACE, CLIMATE CHANGE RES CTR, DURHAM, NH 03824 USA. RI Grootes, Pieter/F-4952-2011; Steig, Eric/G-9088-2015; Taylor, Kendrick/A-3469-2016 OI Steig, Eric/0000-0002-8191-5549; Taylor, Kendrick/0000-0001-8535-1261 NR 28 TC 78 Z9 83 U1 2 U2 8 PU AMER ASSOC ADVANCEMENT SCIENCE PI WASHINGTON PA 1200 NEW YORK AVE, NW, WASHINGTON, DC 20005 USA SN 0036-8075 EI 1095-9203 J9 SCIENCE JI Science PD JUN 14 PY 1996 VL 272 IS 5268 BP 1636 EP 1638 DI 10.1126/science.272.5268.1636 PG 3 WC Multidisciplinary Sciences SC Science & Technology - Other Topics GA UR093 UT WOS:A1996UR09300041 ER PT J AU Huang, SX Fischer, DA Gland, JL AF Huang, SX Fischer, DA Gland, JL TI Aniline adsorption, hydrogenation, and hydrogenolysis on the Ni(100) surface SO JOURNAL OF PHYSICAL CHEMISTRY LA English DT Article ID AMMONIA ADSORPTION; PT(111) SURFACE; NI(110) SURFACE; DECOMPOSITION; ENERGIES; NICKEL; CATALYSIS; BENZENE; XPS AB The bonding and reactions of adsorbed aniline have been characterized on the Ni(100) surface both in hydrogen and in vacuum with a combination of surface spectroscopies. The structure of adsorbed aniline and derived intermediates has been characterized by near-edge X-ray absorption fine structure (NEXAFS) and X-ray photoemission spectroscopy (XPS). The dominant surface reactions have been studied using temperature-programmed reaction spectroscopy (TPRS) and in-situ temperature-programmed fluorescence yield near-edge spectroscopy (TP FYNES). Competition between hydrogenation, hydrogenolysis, and dehydrogenation of aniline in the 300-400 K temperature range depends markedly on hydrogen pressures in the vacuum to 0.01 Torr range. In the absence of external hydrogen, dehydrogenation dominates with increasing temperature. Both hydrogenation and hydrogenolysis of aniline-derived surface intermediates are enhanced dramatically by hydrogen atmospheres. For aniline coverages up to 1 monolayer, hydrogenolysis to form benzene at 475 K is dominant over a broad hydrogen pressure range (> 10(-6) Torr). Ultrasoft X-ray absorption spectra above the carbon K edge of the aniline-derived surface intermediates reveal that the precursor for hydrogenolysis is a hydrogenated aniline-derived species indistinguishable from cyclohexylamine. In the presence of hydrogen, C-N bond activation appears to be correlated with unexpectedly large tilt angles near 55 degrees observed at the hydrogenolysis temperature. In the absence of hydrogen atmospheres, low-temperature loss of amino hydrogen causes the ring to reorient even further away from the surface and therefore remain aromatic with increasing temperature. Both the resonant stabilization of the C-N bond and reorientation of the C-N bond away from the surface contribute to decreased C-N bond activation in the absence of external hydrogen. C1 UNIV MICHIGAN,DEPT CHEM,ANN ARBOR,MI 48109. NIST,MAT SCI & ENGN LAB,GAITHERSBURG,MD 20889. NR 34 TC 24 Z9 25 U1 4 U2 16 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 JUN 13 PY 1996 VL 100 IS 24 BP 10223 EP 10234 DI 10.1021/jp951868s PG 12 WC Chemistry, Physical SC Chemistry GA UQ844 UT WOS:A1996UQ84400033 ER PT J AU Cuntz, M Deeney, BD Brown, A Stencel, RE AF Cuntz, M Deeney, BD Brown, A Stencel, RE TI Short-term chromospheric variability in alpha Tauri (K5 III): Results from IUE time series observations SO ASTROPHYSICAL JOURNAL LA English DT Article DE stars, activity; stars, chromospheres; stars, individual (alpha Tauri); stars, late-type; ultraviolet, stars ID LATE-TYPE STARS; COOL STARS; EMISSION-LINES; GIANT STARS; MASS-LOSS; MAGNETIC-STRUCTURE; GENERATION; SPECTRA; REGIONS; ENERGY AB We evaluate time series observations of chromospheric lines (Mg II, Mg I, and C II) for the K giant alpha Tau obtained using the IUE LWP camera at high dispersion. These observations cover a time span of about 2 weeks in 1994 February-March and were designed to resolve variations occurring within hours, days, and weeks. We consider the observational results in relation to theoretical acoustic heating models, motivated by the fact that alpha Tau may exhibit a basal (i.e., minimum) level of chromospheric activity. The data reveal flux variations between the extremes of 8% in Mg II h+k and 15% in each emission component. These variations occur on timescales as short as 8 hr but not on timescales longer than similar to 3 days. For the h and k components, flux variations occurring on a timescale as short as 1.5 hr are also found. These changes are often not correlated (and are sometimes even anticorrelated), leading to remarkable differences in the h/k ratios. We argue that these results are consistent with the presence of strong acoustic shocks, which can lead to variable Mg II line emission when only a small number of strong shocks are propagating through the atmosphere. We deduce the electron density in the C II] lambda 2325 line formation region to be log N-e similar or equal to 9.0, in agreement with previous studies. Our data provide evidence that the Mg II basal flux limit for K giants might be a factor of 4 higher than suggested by Rutten et al. C1 UNIV HEIDELBERG,INST THEORET ASTROPHYS,D-69121 HEIDELBERG,GERMANY. UNIV COLORADO,JOINT INST LAB ASTROPHYS,BOULDER,CO 80309. NATL INST STAND & TECHNOL,BOULDER,CO 80309. UNIV COLORADO,CTR ASTROPHYS & SPACE ASTRON,BOULDER,CO 80309. UNIV DENVER,DEPT PHYS & ASTRON,DENVER,CO 80208. NR 48 TC 5 Z9 5 U1 0 U2 0 PU UNIV CHICAGO PRESS PI CHICAGO PA 5720 S WOODLAWN AVE, CHICAGO, IL 60637 SN 0004-637X J9 ASTROPHYS J JI Astrophys. J. PD JUN 10 PY 1996 VL 464 IS 1 BP 426 EP 433 DI 10.1086/177333 PN 1 PG 8 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA UN840 UT WOS:A1996UN84000040 ER PT J AU Jain, R Hindman, BW Zweibel, EG AF Jain, R Hindman, BW Zweibel, EG TI The influence of magnetism on p-mode surface amplitudes SO ASTROPHYSICAL JOURNAL LA English DT Article DE Sun, activity; Sun, magnetic fields; Sun, oscillations ID FREQUENCY-SHIFTS; F-MODES; SOLAR; FIELD AB We propose a mechanism to explain the observed suppression of p-mode surface velocities in solar active regions. We show that a horizontal magnetic field can lower the upper turning point and change the shin depth for a simple plane-parallel adiabatically stratified polytrope. In addition to power suppression, the magnetic field alters the phase of p-modes. Simultaneous measurements of phase as well as amplitude in the active and quiet regions would provide an additional diagnostic for probing the structure of active region magnetic fields. C1 UNIV COLORADO, BOULDER, CO 80309 USA. RP Jain, R (reprint author), NATL INST STAND & TECHNOL, JOINT INST LAB ASTROPHYS, CAMPUS BOX 440, BOULDER, CO 80309 USA. OI HINDMAN, BRADLEY/0000-0001-7612-6628 NR 21 TC 16 Z9 16 U1 0 U2 0 PU UNIV CHICAGO PRESS PI CHICAGO PA 5720 S WOODLAWN AVE, CHICAGO, IL 60637 SN 0004-637X J9 ASTROPHYS J JI Astrophys. J. PD JUN 10 PY 1996 VL 464 IS 1 BP 476 EP 486 DI 10.1086/177337 PN 1 PG 11 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA UN840 UT WOS:A1996UN84000044 ER PT J AU Fernandez, J Yu, TT Rundle, JB AF Fernandez, J Yu, TT Rundle, JB TI Horizontal viscoelastic-gravitational displacement due to a rectangular dipping thrust fault in a layered Earth model SO JOURNAL OF GEOPHYSICAL RESEARCH-SOLID EARTH LA English DT Article ID CRUSTAL DEFORMATION; HALF-SPACE; JAPAN; CYCLE; ASTHENOSPHERE; ARRAYS; ZONES AB Calculations of horizontal displacements due to a rectangular finite thrust fault in a viscoelastic-gravitational layered Earth model are presented The Earth model consists of a single elastic-gravitational layer overlying a viscoelastic-gravitational half-space. A review of the full three-dimensional theoretical solutions is presented along with the explicit solutions for horizontal displacements. Several examples of computations for dipping faults with various angles, and located at different depths, are shown. The results indicate that viscoelasticity introduces a long-wavelength component into the interseismic deformation field which is not present in published elastic techniques and also that a proper consideration of gravity is necessary only for near-field computations at longer periods of time. A pattern is found in the cumulative displacement of cycled earthquakes, which indicates that the viscoelastic displacements are visible for longer recurrence time events and that these may serve as a time index for the various stages between cycles. C1 UNIV COLORADO, NOAA, COOPERAT INST RES ENVIRONM SCI, BOULDER, CO 80309 USA. RP Fernandez, J (reprint author), UCM, CSIC, INST ASTRON & GEODESIA, FAC CIENCIAS MATEMAT, CIUDAD UNIV, E-28040 MADRID, SPAIN. RI Fernandez, Jose/K-1669-2014 OI Fernandez, Jose/0000-0001-5745-3527 NR 36 TC 19 Z9 20 U1 0 U2 0 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 2169-9313 EI 2169-9356 J9 J GEOPHYS RES-SOL EA JI J. Geophys. Res.-Solid Earth PD JUN 10 PY 1996 VL 101 IS B6 BP 13581 EP 13594 DI 10.1029/96JB00525 PG 14 WC Geochemistry & Geophysics SC Geochemistry & Geophysics GA UQ014 UT WOS:A1996UQ01400003 ER PT J AU Baker, ET AF Baker, ET TI Geological indexes of hydrothermal venting SO JOURNAL OF GEOPHYSICAL RESEARCH-SOLID EARTH LA English DT Article ID EAST PACIFIC RISE; DE-FUCA RIDGE; CRUSTAL MAGMA CHAMBER; MID-ATLANTIC RIDGE; DEPTH POINT DATA; MIDOCEAN RIDGES; SEISMIC STRUCTURE; SPREADING CENTER; AXIAL PROCESSES; JUAN AB Hydrothermal venting occurs on mid-ocean ridge axes with a diverse array of morphological, structural, and petrological characteristics. Consequently, it is not clear if certain geological environments are more conducive than others to hydrothermal activity. This paper uses complementary data sets recently collected on multiple-tectonic-segment scales along intermediate to superfast spreading ridge sections to systematically examine this issue. The spatial density of venting is gauged by plume incidence, the fraction of linear ridge crest overlain by hydrothermal plumes. Five geological indexes are compared with plume incidence: ridge-axis elevation, ridge-axis cross-sectional area, the percentage of ridge axis underlain by an axial magma chamber (AMC) reflector, MgO wt% in basaltic glass, and spreading rate. A mean value for plume incidence and each index, where available, is calculated for each of 14 second- to fourth-order tectonic segments from the Juan de Fuca Ridge (44 degrees 30' to 48 degrees 45'N) and the northern (9 degrees to 11 degrees 50'N) and southern (13 degrees 50' to 18 degrees 40'S) East Pacific Rise. Plumes are most common on segments with a cross-sectional area > 3.5 km(2), a net elevation > 0.35 km, AMC coverage > 60%, and MgO > 7 wt%. Spreading rate is not deterministic on the segment scale. The data suggest two classes of ridge segments. Segments with relatively low geological index values have a uniformly low plume incidence indicative of a presently feeble magmatic budget. Those with high index values have a plume incidence ranging from low to complete coverage, apparently a consequence of a magma supply rate sufficient to produce frequent dike intrusions and highly variable hydrothermal activity. The best individual predictors of hydrothermal activity are cross-sectional area and net elevation. Applying these indexes to the East Pacific Rise between 18 degrees N and 33 degrees S suggests that the unexplored segments with the highest probability of activity are those at 15 degrees 30'-16 degrees N, 6 degrees-9 degrees N, 5 degrees-6 degrees S, 27 degrees-28 degrees S, and 30 degrees 30'-33 degrees S. RP Baker, ET (reprint author), NOAA, PACIFIC MARINE ENVIRONM LAB, 7600 SAND POINT WAY NE, SEATTLE, WA 98115 USA. NR 73 TC 13 Z9 14 U1 0 U2 4 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 2169-9313 EI 2169-9356 J9 J GEOPHYS RES-SOL EA JI J. Geophys. Res.-Solid Earth PD JUN 10 PY 1996 VL 101 IS B6 BP 13741 EP 13753 DI 10.1029/96JB00820 PG 13 WC Geochemistry & Geophysics SC Geochemistry & Geophysics GA UQ014 UT WOS:A1996UQ01400013 ER PT J AU Jacox, ME Irikura, KK Thompson, WE AF Jacox, ME Irikura, KK Thompson, WE TI Matrix isolation study of the interaction of excited neon atoms with BCl3: Infrared spectra of BCl3+, BCl2+, and BCL(3)(+) SO JOURNAL OF CHEMICAL PHYSICS LA English DT Article ID VIBRATIONAL-SPECTRA; SOLID NEON; ELECTRON-ATTACHMENT; BORON TRICHLORIDE; IONS; ARGON; EXCITATION; STRENGTHS; HALOGENS; ENERGIES AB When a Ne:BCl3 sample is codeposited at approximately 5 K with a beam of neon atoms that have been excited in a microwave discharge, the infrared spectrum of the resulting solid deposit shows a weak to moderately intense absorption of BCl2 and more prominent absorptions which are assigned to the v(3) fundamentals of BCl3+ (D-3h) and of linear, centrosymmetric BCl2+. The boron- and chlorine-isotopic structure of the spectrum is consistent with both of these assignments. Ab initio calculations support the BCl2+ assignment. An absorption is also tentatively assigned to nu(3)(e) of BCl3-. Ab initio calculations for BCl3- are consistent with that assignment. The processes which occur when the solid deposit is exposed to visible and ultraviolet radiation are considered. C1 NIST,DIV CHEM KINET & THERMODYNAM,GAITHERSBURG,MD 20899. RP Jacox, ME (reprint author), NIST,DIV MOLEC PHYS,GAITHERSBURG,MD 20899, USA. RI Irikura, Karl/A-4266-2009 OI Irikura, Karl/0000-0001-7515-6761 NR 42 TC 13 Z9 13 U1 0 U2 0 PU AMER INST PHYSICS PI WOODBURY PA CIRCULATION FULFILLMENT DIV, 500 SUNNYSIDE BLVD, WOODBURY, NY 11797-2999 SN 0021-9606 J9 J CHEM PHYS JI J. Chem. Phys. PD JUN 8 PY 1996 VL 104 IS 22 BP 8871 EP 8878 DI 10.1063/1.471622 PG 8 WC Chemistry, Physical; Physics, Atomic, Molecular & Chemical SC Chemistry; Physics GA UP202 UT WOS:A1996UP20200005 ER PT J AU Scott, DL Penn, LS Weetall, HH AF Scott, DL Penn, LS Weetall, HH TI Evaluation of the potential usefulness of in situ fiber optic sensors for column monitoring in chromatographic separations and purifications SO JOURNAL OF CHROMATOGRAPHY A LA English DT Article DE fiber optic sensors; detection, LC; optical fibers; fluorescence detection; column monitoring; fluorescein ID FLUORESCENCE; PH AB Fiber optic sensors show promise for real-time monitoring of local conditions inside chromatography columns. Experiments on a Sephadex G-50 column, with blue dextran as the test analyte, showed that insertion of a single fiber or a lattice of fibers did not interfere with column fluidics, provided the fiber diameter was within the same order of magnitude as the diameters of the particles composing the column packing. Experiments on a Sephadex G-50 column, with fluorescein as the test analyte, showed that column packing particles do not interfere with the sensor's ability to accurately reflect differences in fluorescence produced by fluorescein under different conditions (e.g., concentration, pH). Experiments with fluorescein on a G-50 column also showed that fiber optic sensors can be used to monitor local analyte concentrations within a column and to diagnose column problems which lead to reduced column efficiency. C1 UNIV KENTUCKY,DEPT CHEM & MAT ENGN,LEXINGTON,KY 40506. NATL INST STAND & TECHNOL,GAITHERSBURG,MD 20899. NR 20 TC 2 Z9 2 U1 0 U2 1 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0021-9673 J9 J CHROMATOGR A JI J. Chromatogr. A PD JUN 7 PY 1996 VL 736 IS 1-2 BP 51 EP 59 DI 10.1016/0021-9673(95)01364-4 PG 9 WC Biochemical Research Methods; Chemistry, Analytical SC Biochemistry & Molecular Biology; Chemistry GA UV349 UT WOS:A1996UV34900006 ER PT J AU Bruno, TJ Wertz, KH AF Bruno, TJ Wertz, KH TI Retention of halocarbons on a hexafluoropropylene epoxide modified graphitized carbon black .6. Eleven fluoroethers and two iodofluoroalkanes SO JOURNAL OF CHROMATOGRAPHY A LA English DT Article DE relative retention; refrigerants, alternative; fluoroethers; iodofluoroalkanes; halocarbons AB The retention characteristics of 11 ether-based and 2 iodinated halocarbon fluids related to alternative refrigerant research have been studied as a function of temperature on a stationary phase consisting of a 5% (by mass) coating of a low-molecular-mass polymer of hexafluoropropylene epoxide on a graphitized carbon black adsorbent. Measurements were performed at 0, 20, 40, 60, and 80 degrees C for R-E125 and R-E134; at 40, 60, 80, and 100 degrees C for R-E143a, R-CE216, R-E236eal, R-E245fal, R-E263fbl, and R13I-1; at 80, 100, 120, and 140 degrees C for R-E235ca2, R-E235dal, R-E347, and R-217I-1; and at 100, 120, 140, and 160 degrees C for R-E280. Measurements were attempted for several other more chlorinated ether-based compounds, but the chromatographic conditions could not be optimized sufficiently to allow standard retention parameters to be measured reliably. Relative retentions as a function of temperature were calculated with respect to the retentions of tetrafluoromethane (R-14) and hexafluoroethane (R-116). Qualitative features of the data are examined, and trends are identified. In addition, the relative retention data were fitted to linear models for the purpose of predicting retention behavior of these compounds to facilitate chromatographic analysis. RP Bruno, TJ (reprint author), NATL INST STAND & TECHNOL,DIV THERMOPHYS,CHEM SCI & TECHNOL LAB,BOULDER,CO 80303, USA. NR 19 TC 3 Z9 3 U1 0 U2 0 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0021-9673 J9 J CHROMATOGR A JI J. Chromatogr. A PD JUN 7 PY 1996 VL 736 IS 1-2 BP 175 EP 184 DI 10.1016/0021-9673(95)01325-3 PG 10 WC Biochemical Research Methods; Chemistry, Analytical SC Biochemistry & Molecular Biology; Chemistry GA UV349 UT WOS:A1996UV34900020 ER PT J AU Wenthold, PG Hrovat, DA Borden, WT Lineberger, WC AF Wenthold, PG Hrovat, DA Borden, WT Lineberger, WC TI Transition-state spectroscopy of cyclooctatetraene SO SCIENCE LA English DT Article ID SINGLET GROUND-STATE; PHOTOELECTRON-SPECTROSCOPY; BOND ALTERNATION; RING INVERSION; 1,2,4,5-TETRAMETHYLENEBENZENE; ABINITIO; ANIONS; PHOTODETACHMENT; PLANARIZATION; DISTRIBUTIONS AB The 351-nanometer photoelectron spectrum of the planar cyclooctatetraene radical anion (COT-) shows transitions to two electronic states of cyclooctatetraene (COT). These states correspond to the D-4h (1)A(1g) state, which is the transition slate for COT ring inversion, and the D-8h (3)A(2u) state. The electron binding energy of the (1)A(1g) transition state is 1.099 +/- 0.010 electron volts, which is lower by 12.1 +/- 0.3 kilocalories per mole than that of the (3)A(2u) state. The photoelectron spectrum shows that the singlet lies well below the triplet in D-8h COT and confirms ab initio predictions that the molecule violates Hund's rule. Vibrational structure is observed for both features and is readily assigned by use of a simple potential energy surface. C1 UNIV WASHINGTON,DEPT CHEM,SEATTLE,WA 98195. 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 51 TC 174 Z9 174 U1 8 U2 37 PU AMER ASSOC ADVANCEMENT SCIENCE PI WASHINGTON PA 1200 NEW YORK AVE, NW, WASHINGTON, DC 20005 SN 0036-8075 J9 SCIENCE JI Science PD JUN 7 PY 1996 VL 272 IS 5267 BP 1456 EP 1459 DI 10.1126/science.272.5267.1456 PG 4 WC Multidisciplinary Sciences SC Science & Technology - Other Topics GA UP899 UT WOS:A1996UP89900039 ER PT J AU Bodammer, JE Robohm, RA AF Bodammer, JE Robohm, RA TI Ultrastructural observations on the phagocytic behavior of winter flounder Pleuronectes americanus peritoneal neutrophils and macrophages in vivo SO DISEASES OF AQUATIC ORGANISMS LA English DT Article DE winter flounder; ultrastructure; peritoneal phagocytes; in vivo ID CYPRINUS-CARPIO L; PLATESSA L; INFLAMMATORY CELLS; EXUDATE CELLS; RAINBOW-TROUT; LEUKOCYTES; PLAICE; LIGHT; BLOOD AB A qualitative electron microscopical examination of peritoneal phagocytes in winter flounder Pleuronectes americanus after brief (i.e. 30 or 60 min) exposure to formalin-killed Bacillus cereus or Yersinia ruckeri revealed that both neutrophils and macrophages had phagocytozed bacteria. Neutrophils obtained from both the peritoneal cavity and from the head kidney were identified on the basis of their overall cytological appearance and more specifically on the presence of elongated, striated (fibrillar) appearing granules in their cytoplasm which stained positively for peroxidase. Macrophages recovered from the peritoneal cavity were phagocytic like neutrophils; however, they were not observed to contain peroxidase. The surface membrane changes observed for 'activated' neutrophils and macrophages which had engulfed bacteria were consistent with those reported for other fish species and higher vertebrates. Images of aggregated cells suggestive of cellular communication between lymphocytes, macrophages, and/or neutrophils are provided. C1 NOAA, NATL MARINE FISHERIES SERV, NE FISHERIES CTR, MILFORD, CT 06460 USA. RP UNIV RHODE ISL, NOAA, COOPERAT MARINE EDUC & RES PROGRAM, DEPT FISHERIES ANIM & VET SCI, KINGSTON, RI 02881 USA. NR 46 TC 7 Z9 7 U1 0 U2 0 PU INTER-RESEARCH PI OLDENDORF LUHE PA NORDBUNTE 23, D-21385 OLDENDORF LUHE, GERMANY SN 0177-5103 EI 1616-1580 J9 DIS AQUAT ORGAN JI Dis. Aquat. Org. PD JUN 6 PY 1996 VL 25 IS 3 BP 197 EP 208 DI 10.3354/dao025197 PG 12 WC Fisheries; Veterinary Sciences SC Fisheries; Veterinary Sciences GA UW894 UT WOS:A1996UW89400005 ER PT J AU Wijmans, CM Factor, BJ AF Wijmans, CM Factor, BJ TI Self-consistent-field calculations of tethered chains in the presence of mobile homopolymer: Comparison with experiment SO MACROMOLECULES LA English DT Article ID DIBLOCK COPOLYMER MONOLAYERS; ANGLE NEUTRON-SCATTERING; POLYMER BRUSHES; DENSITY PROFILE; INTERFACE; MELT AB Concentration profiles of tethered polymer chains in the presence of mobile homopolymer under good solvent conditions have been calculated using self-consistent field (SCF) methods which incorporated the experimental conditions of a recent neutron reflectivity study by Lee et al. [J. Chem. Sec., Faraday Discuss. 1994, 98, 139]. While there is good qualitative agreement between the experimental results and the SCF calculations, the calculations predict a larger decrease in the tethered layer heights than is observed in the experiments. Furthermore, with increasing mobile polymer molecular weight, the calculations predict concentration profile shapes which become more steplike. The feasibility of discerning this effect using either neutron reflectivity or small angle neutron scattering is discussed. C1 NIST,DIV POLYMERS,MAT SCI & ENGN LAB,GAITHERSBURG,MD 20899. RP Wijmans, CM (reprint author), LUND UNIV,CTR CHEM & CHEM ENGN,POB 124,S-22100 LUND,SWEDEN. NR 30 TC 14 Z9 14 U1 0 U2 1 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 SN 0024-9297 J9 MACROMOLECULES JI Macromolecules PD JUN 3 PY 1996 VL 29 IS 12 BP 4406 EP 4411 DI 10.1021/ma9514028 PG 6 WC Polymer Science SC Polymer Science GA UP860 UT WOS:A1996UP86000033 ER PT J AU Sung, L Karim, A Douglas, JF Han, CC AF Sung, L Karim, A Douglas, JF Han, CC TI Dimensional crossover in the phase separation kinetics of thin polymer blend films SO PHYSICAL REVIEW LETTERS LA English DT Article ID SPINODAL DECOMPOSITION; MIXTURE; TEMPERATURE; SIZE AB The kinetics of phase separation in thin polymer blend films of polystyrene and polybutadiene on a silicon substrate is examined by optical microscopy of the free film boundary. Our observations on 1000 and 200 Angstrom films are consistent with a crossover from three- to two-dimensional spinodal decomposition kinetics in the (off-critical) viscous hydrodynamic regime. In this stage of phase separation the exponent n, characterizing the scale R(t) similar to t(n) of the coarsening pattern, is predicted to change from 1 to a value near 0.46 upon lowering the dimensionality. RP Sung, L (reprint author), NATL INST STAND & TECHNOL,DIV POLYMERS,GAITHERSBURG,MD 20899, USA. NR 34 TC 178 Z9 184 U1 1 U2 26 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 0031-9007 J9 PHYS REV LETT JI Phys. Rev. Lett. PD JUN 3 PY 1996 VL 76 IS 23 BP 4368 EP 4371 DI 10.1103/PhysRevLett.76.4368 PG 4 WC Physics, Multidisciplinary SC Physics GA UN800 UT WOS:A1996UN80000019 ER PT J AU Lee, SH Broholm, C Aeppli, G Perring, TG Hessen, B Taylor, A AF Lee, SH Broholm, C Aeppli, G Perring, TG Hessen, B Taylor, A TI Isolated spin pairs and two-dimensional magnetism in SrCr9pGa12-9pO19 SO PHYSICAL REVIEW LETTERS LA English DT Article ID HEISENBERG KAGOME ANTIFERROMAGNET; LATTICE; ORDER; FRUSTRATION; FLUCTUATIONS; DILUTION; DISORDER; GLASS AB We show by inelastic neutron scattering that the frustrated magnet SrCr9pGa12-9pO19 [p = 0.92(5)] has dispersionless magnetic excitations at energies 18.6(1) and 37.2(5) meV. The wave vector and temperature dependence of the excitations as well as the ratio 1:2 of excitation energies is perfectly accounted for by isolated antiferromagnetically exchange coupled pairs of spins s = 3/2. Consideration of the layered structure of magnetic chromium ions and the ligand environment indicates that these pairs are adjacent spins in neighboring triangular lattice planes which separate two-dimensional sublattices of interacting kagome-triangle-kagome layers. C1 NATL INST STAND & TECHNOL,GAITHERSBURG,MD 20899. NEC CORP LTD,PRINCETON,NJ 08540. RUTHERFORD APPLETON LAB,ISIS FACIL,DIDCOT OX11 0QX,OXON,ENGLAND. ROYAL DUTCH SHELL LABS,1033 AA AMSTERDAM,NETHERLANDS. RP Lee, SH (reprint author), JOHNS HOPKINS UNIV,DEPT PHYS & ASTRON,BALTIMORE,MD 21218, USA. RI Broholm, Collin/E-8228-2011 OI Broholm, Collin/0000-0002-1569-9892 NR 26 TC 82 Z9 82 U1 3 U2 13 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 0031-9007 J9 PHYS REV LETT JI Phys. Rev. Lett. PD JUN 3 PY 1996 VL 76 IS 23 BP 4424 EP 4427 DI 10.1103/PhysRevLett.76.4424 PG 4 WC Physics, Multidisciplinary SC Physics GA UN800 UT WOS:A1996UN80000033 ER PT J AU Thomas, CL Tseng, AA Bur, AJ Rose, JL AF Thomas, CL Tseng, AA Bur, AJ Rose, JL TI Solidification sensing for closed loop control of injection molding hold time SO ADVANCES IN POLYMER TECHNOLOGY LA English DT Article ID SIMULATION; POLYMERS AB Hold time for injection molding is currently controlled open loop, using a fixed time delay set by the machine operator. Insufficient hold time leads to inconsistent moldings, while excessive hold time increases the cost of the part. We have developed new sensors that monitor the solidification of polymer in the mold. A closed loop strategy is demonstrated where the hold time is automatically controlled based on feedback from a solidification sensor. Using this strategy, the hold time is set once in reference to the sensor signal, providing the minimum proper hold time for each part under changing processing conditions. (C) 1996 John Wiley & Sons, Inc. C1 DREXEL UNIV,DEPT MECH ENGN,PHILADELPHIA,PA 19104. NIST,DIV POLYMERS,GAITHERSBURG,MD 20899. PENN STATE UNIV,DEPT ENGN SCI & MECH,UNIVERSITY PK,PA 16802. RP Thomas, CL (reprint author), UNIV UTAH,DEPT MECH ENGN,SALT LAKE CITY,UT 84112, USA. NR 23 TC 4 Z9 4 U1 0 U2 0 PU JOHN WILEY & SONS INC PI NEW YORK PA 605 THIRD AVE, NEW YORK, NY 10158-0012 SN 0730-6679 J9 ADV POLYM TECH JI Adv. Polym. Technol. PD SUM PY 1996 VL 15 IS 2 BP 151 EP 163 PG 13 WC Engineering, Chemical; Polymer Science SC Engineering; Polymer Science GA UH443 UT WOS:A1996UH44300005 ER PT J AU Gardner, WS StJohn, PA Evans, C Cavaletto, JF AF Gardner, WS StJohn, PA Evans, C Cavaletto, JF TI HPLC retention-time-shift determination of nitrogen isotope ratios in enriched water SO AMERICAN LABORATORY LA English DT Article ID RATES AB Stable isotopes are used as tracers to follow the fate of elements in organisms. This article describes a technique to determine nitrogen isotope ratios of ammonium in enriched water for isotope dilution experiments using direct-injection cation-exchange HPLC with post-column derivatization and measurement of retention time shifts. C1 ST JOHN ASSOCIATES INC,BELTSVILLE,MD. UNIV MICHIGAN,DEPT CHEM,ANN ARBOR,MI 48109. RP Gardner, WS (reprint author), NOAA,GREAT LAKES ENVIRONM RES LAB,2205 COMMONWEALTH BLVD,ANN ARBOR,MI 48105, USA. NR 7 TC 0 Z9 0 U1 0 U2 2 PU INT SCIENTIFIC COMMUN INC PI SHELTON PA PO BOX 870, 30 CONTROLS DRIVE, SHELTON, CT 06484-0870 SN 0044-7749 J9 AM LAB JI Am. Lab. PD JUN PY 1996 VL 28 IS 9 BP C17 EP & PG 5 WC Chemistry, Analytical; Instruments & Instrumentation SC Chemistry; Instruments & Instrumentation GA UR677 UT WOS:A1996UR67700003 ER PT J AU Gaggiotti, OE Smouse, PE AF Gaggiotti, OE Smouse, PE TI Stochastic migration and maintenance of genetic variation in sink populations SO AMERICAN NATURALIST LA English DT Article ID NONEQUILIBRIUM MODELS; BOTTLENECKS; EXTINCTION; HETEROZYGOSITY; ENVIRONMENTS; VARIABILITY; GROWTH; NUMBER; SIZE AB We explore the effect that demographic parameters and different patterns of migration have on the maintenance of genetic variability in a single sink population that receives migrants from a source population and whose size changes with time. We use, as a measure of genetic variability, the expected number of nucleotide differences between two genes randomly sampled from the sink. We assume that changes in the environment are translated into changes in the number of individuals arriving at the sink. We show that the pattern of migration from source to sink affects the amount of genetic variation maintained within the sink. The level of heterozygosity maintained within the sink is negatively correlated with the migrational variance, being lowest under stochastic migration patterns that lead to long runs of no migration events. If migration is indeed stochastic, a purely deterministic treatment of this process will be highly misleading in particular cases and will generally result in some loss of useful information. We also show that the relative importance of migration, genetic drift, and mutation, as they affect the amount of genetic variation maintained within the sink, is a function of the rate of population decay. C1 RUTGERS STATE UNIV,COOK COLL,CTR THEORET & APPL GENET,NEW BRUNSWICK,NJ 08903. RP Gaggiotti, OE (reprint author), NOAA,SW FISHERIES SCI CTR,POB 271,LA JOLLA,CA 92038, USA. RI Gaggiotti, Oscar/G-2459-2010 OI Gaggiotti, Oscar/0000-0003-1827-1493 NR 23 TC 25 Z9 25 U1 0 U2 10 PU UNIV CHICAGO PRESS PI CHICAGO PA 5720 S WOODLAWN AVE, CHICAGO, IL 60637 SN 0003-0147 J9 AM NAT JI Am. Nat. PD JUN PY 1996 VL 147 IS 6 BP 919 EP 945 DI 10.1086/285886 PG 27 WC Ecology; Evolutionary Biology SC Environmental Sciences & Ecology; Evolutionary Biology GA UP976 UT WOS:A1996UP97600003 ER PT J AU Schloesser, DW Nalepa, TF Mackie, GL AF Schloesser, DW Nalepa, TF Mackie, GL TI Zebra mussel infestation of unionid bivalves (Unionidae) in North America SO AMERICAN ZOOLOGIST LA English DT Article; Proceedings Paper CT Symposium on the Biology, Ecology, and Physiology of Zebra Mussels, at the American-Society-of-Zoologists Annual Meeting CY JAN 05, 1995 CL ST LOUIS, MO SP Amer Soc Zoologists ID FRESH-WATER MUSSELS; WESTERN LAKE ERIE; DREISSENA-POLYMORPHA; GREAT-LAKES; ST-CLAIR; MISSISSIPPI RIVER; QUAGGA MUSSEL; COLONIZATION; ABUNDANCE; DECLINE AB In 1989, zebra mussels received national attention in North America when they reached densities exceeding 750,000/m(2) in a water withdrawal facility along the share of western Lake Erie of the Laurentian Great Lakes. Although water withdrawal problems caused by zebra mussels have been of immediate concern, ecological impacts attributed to mussels are likely to be the more important long-term issue for surface waters iii North America. To date, the epizoic colonization (i.e., infestation) of unionid bivalve mollusks by zebra mussels has caused the most direct and severe ecological impact. Infestation of and resulting impacts caused by zebra mussels on unionids in the Great Lakes began in 1988. By 1990, mortality of unionids was occurring at some locations; by 1991, extant populations of unionids in western Lake Erie were nearly extirpated; by 1932, unionid populations in the southern half of Lake St. Clair were extirpated; by 1993, unionids in widely separated geographic areas of the Great; Lakes and the Mississippi River showed high mortality due to mussel infestation. All infested unionid species in the Great Lakes (23) have become infested and exhibited mortality within two to four years after heavy infestation began. Data indicate that mean zebra mussel densities >5,000-6,000/m(2) and infestation intensities >100-200/unionid in the presence of heavy zebra mussel recruitment results in near total mortality of unionids. At present, all unionid species in rivers, streams, and lakes that sympatrically occur with zebra mussels have been infested and, in many locations, negatively impacted by zebra mussels. We do not know the potential consequences of infestation on the 297 unionid species found in North America, but believe zebra mussels pose an immediate threat to the abundance and diversity of unionids. C1 NOAA,GREAT LAKES ENVIRONM RES LAB,ANN ARBOR,MI 48105. UNIV GUELPH,DEPT ZOOL,GUELPH,ON N1G 2W1,CANADA. RP Schloesser, DW (reprint author), NATL BIOL SERV,GREAT LAKES SCI CTR,ANN ARBOR,MI 48105, USA. NR 34 TC 118 Z9 122 U1 3 U2 27 PU AMER SOC ZOOLOGISTS PI LAWRENCE PA 1041 NEW HAMPSHIRE ST, LAWRENCE, KS 66044 SN 0003-1569 J9 AM ZOOL JI Am. Zool. PD JUN PY 1996 VL 36 IS 3 BP 300 EP 310 PG 11 WC Zoology SC Zoology GA VC207 UT WOS:A1996VC20700007 ER PT J AU Stolorow, AM Duewer, DL Reeder, DJ Buel, E Herrin, G AF Stolorow, AM Duewer, DL Reeder, DJ Buel, E Herrin, G TI Interlaboratory comparison of autoradiographic DNA profiling measurements .3. Repeatability and reproducibility of restriction fragment length polymorphism band sizing, particularly bands of molecular size >10K base pairs SO ANALYTICAL CHEMISTRY LA English DT Article AB The observed interlaboratory standard deviation (SD) associated with the restriction fragment length polymorphism (RFLP) measurement of DNA fragment size is a predictable function of the observed mean band size (MBS), For DNA fragments of size 1000 base pairs (bp) to the largest resolved component of commonly used ''sizing ladder'' calibration materials (about 20000 bp), the variation in the sizing data from the Technical Working Group on DNA Analysis Methods (TWGDAM)-sponsored ''Large Fragment Study'' is well-described by SD = 7.5 (1 + MBS/19 500)(7.1). This sizing variability arises from a 0.1 - 0.4% SD in the relative positions of sample and calibration bands among electrophoretic gels. Statistically significant sizing differences do exist for bands above 10000 bp among laboratories that use different calibration materials, The Large Fragment Study was efficiently accomplished through the use of a designed set of DNA samples, requiring but one gel in each of 20 participating laboratories. C1 NATL INST STAND & TECHNOL,CHEM SCI & TECHNOL LAB,GAITHERSBURG,MD 20899. STATE VERMONT FORENS LAB,WATERBURY,VT 05676. GEORGIA BUR INVEST,DIV FORENS SCI,DECATUR,GA 30034. RI Duewer, David/B-7410-2008 NR 9 TC 15 Z9 16 U1 0 U2 1 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 SN 0003-2700 J9 ANAL CHEM JI Anal. Chem. PD JUN 1 PY 1996 VL 68 IS 11 BP 1941 EP 1947 DI 10.1021/ac951138g PG 7 WC Chemistry, Analytical SC Chemistry GA UN470 UT WOS:A1996UN47000025 PM 8686915 ER PT J AU Hardy, RW AF Hardy, RW TI Alternate protein sources for salmon and trout diets SO ANIMAL FEED SCIENCE AND TECHNOLOGY LA English DT Article; Proceedings Paper CT 28th Pacific Northwest Animal Nutrition Conference CY OCT 26-28, 1993 CL BOISE, ID SP Univ Idaho, Idaho Feed & Grain Assoc, Oregon State Univ, Oregon Feed & Grain Assoc, Washington State Univ, Pacific NW Grain & Feed Assoc, Univ Brit Columbia, Brit Columbia Feed Ind Assoc, Alltech Inc, Hoffmann LaRoche Inc, J R Simplot Co, Kemin Ind, Pitman Moore Co, Zinpro Corp, Heart Land Lysine, Chicago, Ill DE aquaculture feeds; fish nutrition; fish feeds; alternate protein sources ID RAINBOW-TROUT; ONCORHYNCHUS-MYKISS; FISH-MEAL; ARGININE; REQUIREMENTS; HISTIDINE; EROSION; CHINOOK AB Growth of aquaculture throughout the world requires increased production of fish feeds. Increased production of fish feed will require increased quantities of feed ingredients, mainly protein sources. Most high-value species of fish raised by aquaculture are carnivores requiring feeds containing 400 g kg(-1) or more protein, generally supplied by fish meal. World fish meal production is not expected to increase beyond current levels. This has stimulated research into alternatives to fish meal to supply protein in fish feeds, such as animal and fish processing by-product meals, oilseed proteins and concentrates, and protein concentrates produced from grains. Most alternate protein sources have one or more negative attributes that limit their use in fish feeds. One major concern is how the use of alternate protein sources affect the content of fish farm effluent water. Innovative research on reducing or mitigating the negative qualities of alternate protein sources is increasing the potential for their use in fish feeds and will help alleviate future demands for fish meal by the aquaculture industry. RP Hardy, RW (reprint author), NW FISHERIES SCI CTR, 2725 MONTLAKE BLVD E, SEATTLE, WA 98112 USA. NR 26 TC 121 Z9 127 U1 3 U2 17 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0377-8401 J9 ANIM FEED SCI TECH JI Anim. Feed Sci. Technol. PD JUN 1 PY 1996 VL 59 IS 1-3 BP 71 EP 80 DI 10.1016/0377-8401(95)00888-8 PG 10 WC Agriculture, Dairy & Animal Science SC Agriculture GA UX708 UT WOS:A1996UX70800008 ER PT J AU Wuest, M Young, DT Thomsen, MF Barraclough, BL Singer, HJ Anderson, RR AF Wuest, M Young, DT Thomsen, MF Barraclough, BL Singer, HJ Anderson, RR TI Dispersive O+ conics observed in the plasma-sheet boundary layer with CRRES/LOMICS during a magnetic storm SO ANNALES GEOPHYSICAE-ATMOSPHERES HYDROSPHERES AND SPACE SCIENCES LA English DT Article ID MAGNETOSPHERIC ION COMPOSITION; MASS-SPECTROMETER; IONOSPHERIC IONS; CYCLOTRON WAVES; LOBE BOUNDARY; MAGNETOTAIL; CRRES; BEAMS; DISTRIBUTIONS; ACCELERATION AB We present initial results from the Low-energy magnetospheric ion composition sensor (LOMICS) on the Combined release and radiation effects satellite (CRRES) together with electron, magnetic field, and electric field wave data. LOMICS measures all important magnetospheric ion species (H+, He++, He+, O++, O+) simultaneously in the energy range 60 eV to 45 keV, as well as their pitch-angle distributions, within the time resolution afforded by the spacecraft spin period of 30 s. During the geomagnetic storm of 9 July 1991, over a period of 42 min (0734 UT to 0816 UT) the LOMICS ion mass spectrometer observed an apparent O+ conic flowing away from the southern hemisphere with a bulk velocity that decreased exponentially with time from 300 km/s to 50 km/s, while its temperature also decreased exponentially from 700 to 5 eV. At the onset of the O+ conic, intense low-frequency electromagnetic wave activity and strong pitch-angle scattering were also observed. At the time of the observations the CRRES spacecraft was inbound at L approximate to 7.5 near dusk, magnetic local time (MLT), and at a magnetic latitude of -23 degrees. Our analysis using several CRRES instruments suggests that the spacecraft was skimming along the plasma sheet boundary layer (PSBL) when the upward-flowing ion conic arrived. The conic appears to have evolved in time, both slowing and cooling, due to wave-particle interactions. We are unable to conclude whether the conic was causally associated with spatial structures of the PSBL or the central plasma sheet. C1 UNIV CALIF LOS ALAMOS NATL LAB,GRP SST 7,LOS ALAMOS,NM 87545. NOAA,SPACE ENVIRONM LAB,BOULDER,CO 80303. UNIV IOWA,DEPT PHYS & ASTRON,IOWA CITY,IA 52242. RP Wuest, M (reprint author), SW RES INST,DEPT SPACE SCI,6220 CULEBRA RD,SAN ANTONIO,TX 78228, USA. NR 39 TC 0 Z9 0 U1 0 U2 1 PU SPRINGER VERLAG PI NEW YORK PA 175 FIFTH AVE, NEW YORK, NY 10010 SN 0992-7689 J9 ANN GEOPHYS JI Ann. Geophys.-Atmos. Hydrospheres Space Sci. PD JUN PY 1996 VL 14 IS 6 BP 593 EP 607 PG 15 WC Astronomy & Astrophysics; Geosciences, Multidisciplinary; Meteorology & Atmospheric Sciences SC Astronomy & Astrophysics; Geology; Meteorology & Atmospheric Sciences GA UT714 UT WOS:A1996UT71400003 ER PT J AU Brault, JW AF Brault, JW TI New approach to high-precision Fourier transform spectrometer design SO APPLIED OPTICS LA English DT Article AB Laser fringes have long been used to establish the x axis in interferometric spectrometry, but solutions for the intensity axis have been less satisfactory. Now we are seeing the rapid commercial development of low-cost, medium-speed, sigma-delta analog-to-digital converters developed for stereo audio applications. A single chip provides two channels of 20-bit precision at 50 kHz, a significant improvement over many current systems of much greater cost and complexity. But while the laser works in the spatial domain, this converter operates strictly in the time domain; it cannot be triggered. I have developed a bridge between these two domains, the adaptive digital filter, which not only permits us to use this converter to obtain measurements at arbitrary times but as a bonus shows us how to move much of the complexity of an interferometric-control and data-acquisition system from hardware to software. For example, flexible fringe subdivision (to increase the free spectral range) is easily obtained with a simple and efficient algorithm, completely free of laser ghosts. Compensation for drive velocity variation is also possible, requiring only a modest increase in computer memory. C1 UNIV COLORADO,COOPERAT INST RES ENVIRONM SCI,BOULDER,CO 80303. RP Brault, JW (reprint author), NOAA,325 BROADWAY,BOULDER,CO 80303, USA. NR 2 TC 67 Z9 69 U1 3 U2 20 PU OPTICAL SOC AMER PI WASHINGTON PA 2010 MASSACHUSETTS AVE NW, WASHINGTON, DC 20036 SN 0003-6935 J9 APPL OPTICS JI Appl. Optics PD JUN 1 PY 1996 VL 35 IS 16 BP 2891 EP 2896 DI 10.1364/AO.35.002891 PG 6 WC Optics SC Optics GA UQ482 UT WOS:A1996UQ48200020 PM 21085438 ER PT J AU Salit, ML Travis, JC Winchester, MR AF Salit, ML Travis, JC Winchester, MR TI Practical wavelength calibration considerations for UV-visible Fourier-transform spectroscopy SO APPLIED OPTICS LA English DT Article DE wavelength calibration; Fourier-transform spectroscopy wavelength accuracy; wavelength standards; inductively coupled-plasma spectroscopy; spectral interferences; spectral atlas ID INDUCTIVELY-COUPLED PLASMA; ULTRAVIOLET; LINES AB The intrinsic wavelength scale in a modem reference laser-controlled Michelson interferometer-sometimes referred to as the Connes advantage-offers excellent wavelength accuracy with relative ease. Truly superb wavelength accuracy, with total relative uncertainty in line position of the order of several parts in 10(8), should he within reach with single-point, multiplicative calibration. The need for correction of the wavelength scale arises from two practical effects: the use of a finite aperture, from which off-axis rays propagate through the interferometer, and imperfect geometric alignment of the sample beam with the reference beam and the optical ards of the moving mirror. Although an analytical correction can be made for the finite-aperture effect, calibration with a trusted wavelength standard is typically used to accomplish both corrections. Practical aspects of accurate calibration of an interferometer in the UV-visible region are discussed. Critical issues regarding accurate use of a standard external to the sample source and the evaluation and selection of an appropriate standard are addressed. Anomalous results for two different potential wavelength standards measured by Fabry-Perot interferometry (Ar II and Hg-198 I) are observed. RP Salit, ML (reprint author), NIST,CHEM SCI & TECHNOL LAB,DIV ANALYT CHEM,CHEM BLDG,B154,GAITHERSBURG,MD 20899, USA. NR 34 TC 7 Z9 7 U1 1 U2 5 PU OPTICAL SOC AMER PI WASHINGTON PA 2010 MASSACHUSETTS AVE NW, WASHINGTON, DC 20036 SN 0003-6935 J9 APPL OPTICS JI Appl. Optics PD JUN 1 PY 1996 VL 35 IS 16 BP 2960 EP 2970 DI 10.1364/AO.35.002960 PG 11 WC Optics SC Optics GA UQ482 UT WOS:A1996UQ48200030 PM 21085448 ER PT J AU vandenOord, GHJ Doyle, JG Rodono, M Gary, DE Henry, GW Byrne, PB Linsky, JL Haisch, BM Pagano, I Leto, G AF vandenOord, GHJ Doyle, JG Rodono, M Gary, DE Henry, GW Byrne, PB Linsky, JL Haisch, BM Pagano, I Leto, G TI Flare energetics: Analysis of a large flare on YZ Canis Minoris observed simultaneously in the ultraviolet, optical and radio SO ASTRONOMY & ASTROPHYSICS LA English DT Article DE YZ CMi, activity; atmospheres; late-type; flare; acceleration of particles ID CORONAL MASS EJECTIONS; RS CANUM VENATICORUM; ROTATIONAL MODULATION; X-RAY; IUE OBSERVATIONS; AU MICROSCOPII; DRACONIS STARS; SOLAR-FLARES; DRA SYSTEMS; EQ-PEGASI AB The results of coordinated observations of the dMe star YZ CMI at optical, UV and radio wavelengths during 3 - 7 February 1983 are presented. YZ CMi showed repeated optical flaring with the largest flare having a magnitude of 3.8 in the U-band. This flare coincided with an IUE exposure which permits a comparison of the emission measure curves of YZ CMI in its flaring and quiescent state. During the flare a downward shift of the transition zone is observed while the radiative losses in the range 10(4) - 10(7) K strongly increase. The optical flare is accompanied with a radio flare at 6 cm, while al 20 cm no emission is detected. The flare is interpreted in terms of optically thick synchrotron emission. We present a combined interpretation of the optical/radio flare and show that the flare can be interpreted within the context of solar two-ribbon/white-light flares. Special attention is paid to the bombardment of dMe atmospheres by particle beams. We show that the characteristic temperature of the heated atmosphere is almost independent of the beam flux and lies within the range of solar white-light flare temperatures. We also show that it is unlikely that stellar flares emit black-body spectra. The fraction of accelerated particles, as follows from our combined optical/radio interpretation is in good agreement with the fraction determined by two-ribbon flare reconnection models. C1 ARMAGH OBSERV, ARMAGH BT61 9DG, NORTH IRELAND. UNIV CATANIA, IST ASTRON, I-95125 CATANIA, ITALY. OSSERV ASTROFIS CATANIA, I-95125 CATANIA, ITALY. CALTECH, PASADENA, CA 91125 USA. TENNESSEE STATE UNIV, CTR EXCELLENCE INFORMAT SYST, NASHVILLE, TN 37203 USA. UNIV COLORADO, JOINT INST LAB ASTROPHYS, BOULDER, CO 80309 USA. NATL INST STAND & TECHNOL, BOULDER, CO 80309 USA. LOCKHEED PALO ALTO RES CO, PALO ALTO, CA 94304 USA. CNR, IST RADIOASTRON, I-96017 NOTO, SR, ITALY. RP vandenOord, GHJ (reprint author), STERREKUNDIG INST UTRECHT, POSTBUS 80000, 3508 TA UTRECHT, NETHERLANDS. RI Leto, Giuseppe/N-3355-2015; Pagano, Isabella/I-6934-2015; OI Leto, Giuseppe/0000-0002-0040-5011; Pagano, Isabella/0000-0001-9573-4928; Gary, Dale/0000-0003-2520-8396 NR 65 TC 24 Z9 24 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 JUN PY 1996 VL 310 IS 3 BP 908 EP 922 PG 15 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA UU581 UT WOS:A1996UU58100023 ER PT J AU Dennis, RL Byun, DW Novak, JH Galluppi, KJ Coats, CJ Vouk, MA AF Dennis, RL Byun, DW Novak, JH Galluppi, KJ Coats, CJ Vouk, MA TI The next generation of integrated air quality modeling: EPA's Models-3 SO ATMOSPHERIC ENVIRONMENT LA English DT Article; Proceedings Paper CT International Specialty Conference on Regional Photochemical Measurement and Modeling Studies CY NOV 08-12, 1993 CL SAN DIEGO, CA SP Air & Waste Management Assoc, Amer Meteorol Soc, Amer Geophys Union, Amer Chem Soc, Div Environm Chem, Amer Assoc Aerosol Res DE air quality modeling; high performance computing; Models-3; advanced modeling systems; multipollutant air models ID OZONE PRODUCTION; SYSTEMS AB The U.S. Environmental Protection Agency is developing a third-generation modeling system, termed Models-3. This paper provides an overview of the concepts behind this effort. The modeling challenge is large and is addressed at two main user groups, regulatory analysts and scientists. New technology and tools from the federal High Performance Computing and Communications Program present an opportunity to effectively address computational constraints and the modeling challenge, simultaneously. Two goals of the Advanced Air Quality Modeling Project are (1) provide an effective decision support system and (2) provide a framework to support the evolvement of models and modeling systems. The information needed for a decision support system is described and its elements are defined. The need to be able to significantly evolve the air quality models is discussed next, followed by the presentation of a general software approach for avoiding modeling system obsolescence, In the final section, key modeling considerations and target capabilities are outlined to show the directions being undertaken to initiate Models-3. Copyright (C) 1996 Published by Elsevier Science Ltd C1 MCNC,N CAROLINA SUPERCOMP PROGRAM,ENVIRONM PROGRAMS,RES TRIANGLE PK,NC 27709. N CAROLINA STATE UNIV,DEPT COMP SCI,RALEIGH,NC 27695. RP Dennis, RL (reprint author), NOAA,AIR RESOURCES LAB,ATMOSPHER SCI MODELING DIV,RES TRIANGLE PK,NC, USA. NR 45 TC 76 Z9 96 U1 0 U2 8 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD, ENGLAND OX5 1GB SN 1352-2310 J9 ATMOS ENVIRON JI Atmos. Environ. PD JUN PY 1996 VL 30 IS 12 BP 1925 EP 1938 DI 10.1016/1352-2310(95)00174-3 PG 14 WC Environmental Sciences; Meteorology & Atmospheric Sciences SC Environmental Sciences & Ecology; Meteorology & Atmospheric Sciences GA UH931 UT WOS:A1996UH93100003 ER PT J AU Gillani, NV Pleim, JE AF Gillani, NV Pleim, JE TI Sub-grid-scale features of anthropogenic emissions of NOx and VOC in the context of regional Eulerian models SO ATMOSPHERIC ENVIRONMENT LA English DT Article; Proceedings Paper CT International Specialty Conference on Regional Photochemical Measurement and Modeling Studies CY NOV 08-12, 1993 CL SAN DIEGO, CA SP Air & Waste Management Assoc, Amer Meteorol Soc, Amer Geophys Union, Amer Chem Soc, Div Environm Chem, Amer Assoc Aerosol Res DE anthropogenic emissions of VOC and NOx; grid models; sub-grid-scale features; plume-in-grid ID POWER-PLANT PLUMES; SUBGRID REPRESENTATION; CHEMISTRY; URBAN; OZONE; PHOTOCHEMISTRY AB Model uncertainty is a major issue concerning regional-scale air quality simulation. One major source of uncertainty in regional Eulerian models is due to sub-grid-scale (SGS) effects related to anthropogenic emissions. Regional models typically have horizontal grid resolution (Delta) of 20-80 km. Since NOx chemistry in plumes is nonlinear and often diffusion-limited, the sudden dilution of plumes over regional grid dimensions, as in current models, can lead to a fundamental distortion of their chemistry, resulting in over-production of ozone, peroxides, sulfates and nitrates in the source region, and a related over-depletion of NOx. The corresponding model uncertainty over the whole regional domain remains unquantified. In this paper, we use high-resolution information from urban and regional emission inventories and plume field studies to examine SGS features of the emissions of anthropogenic NOx and VOC (volatile organic compounds), and of their mesoscale dispersion and chemistry. Such examination provides useful insight into some of the main sources of SGS uncertainty, as well as guidance for reducing it. The mesoscale chemistry of power plant plumes is very diffusion-limited, being controlled by VOC entrainment from the background. The crosswind spread of large point-source plumes typically takes 4-6 h to reach 30 km in convective conditions, and at least a full diurnal cycle to reach 80 km. For Delta much larger than 20-30 km, regional models will not be able to capture the essence of the behavior of rural point-source plumes even with plume-in-grid treatment, or to resolve the NOx emissions from many large power plants in urban peripheries from the urban VOC emissions. Within urban areas, there is progressive improvement in the resolution of the important ratio VOC/NOx as Delta is decreased below 20 km. The nature of these emissions-related SGS features suggests that significant gain in regional model accuracy should result by limiting Delta to 20-30 km in the regional domain, by the use of finer nested gridding in metropolitan sub-domains, and by a reactive plume-in-grid treatment of major point-source emissions. Copyright (C) 1996 Elsevier Science Ltd C1 N CAROLINA STATE UNIV,DEPT MARINE EARTH & ATMOSPHER SCI,RALEIGH,NC 27695. NOAA,AIR RESOURCES LAB,ATMOSPHER SCI MODELING DIV,RES TRIANGLE PK,NC 27711. RI Pleim, Jonathan Pleim/C-1331-2017 OI Pleim, Jonathan Pleim/0000-0001-6190-6082 NR 33 TC 33 Z9 33 U1 1 U2 10 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD, ENGLAND OX5 1GB SN 1352-2310 J9 ATMOS ENVIRON JI Atmos. Environ. PD JUN PY 1996 VL 30 IS 12 BP 2043 EP 2059 DI 10.1016/1352-2310(95)00201-4 PG 17 WC Environmental Sciences; Meteorology & Atmospheric Sciences SC Environmental Sciences & Ecology; Meteorology & Atmospheric Sciences GA UH931 UT WOS:A1996UH93100010 ER PT J AU Progar, JJ May, JC Rains, TC Watters, RL Yu, L AF Progar, JJ May, JC Rains, TC Watters, RL Yu, L TI Preparation of an intra-laboratory reference material - Determination of the aluminum content of a pooled 5% albumin (human) solution by ETAAS, MFS and ICP-AES SO BIOLOGICALS LA English DT Article ID DIALYSIS ENCEPHALOPATHY SYNDROME; CONTAMINATION; TOXICITY; PLASMA; BONE AB Human albumin solutions as well as other biological products intended for human use may contain aluminum as a result of intentional addition due to manufacturing protocol or through inadvertent contamination occuring during the manufacturing process. Because of the implication of aluminum in human disease, it is desirable that aluminum levels in these products be monitored. To satisfy the need for a reference material that is representative of albumin products that are intended for therapeutic use, a pooled 5% human albumin solution was prepared in bulk to serve as a reference for aluminum during analytical procedures. Aliquots of the albumin pool were analyzed for their aluminum content by three independent analytical methods, namely, electrothermal atomic absorption, molecular fluorescence and inductively coupled plasma-atomic emission spectrometry. Measured values for aluminum in the albumin solution showed good agreement between the different analytical methods. The concentration of aluminum was determined to be 0.512 mu g Al/ml by the atomic absorption method, 0.502 mu g Al/ml by molecular fluorescence, and 0.498 mu g Al/ml by the inductively coupled plasma-atomic emission method. The overall average concentration was calculated to be 0.507 mu g/ml +/- 0.009 mu g Al/ml. The preparation of the albumin reference and its subsequent aluminum analysis is described. (C) 1996 The International Association of Biological Standardization C1 US DEPT COMMERCE,NATL INST STAND & TECHNOL,GAITHERSBURG,MD 20899. RP Progar, JJ (reprint author), US FDA,CTR BIOL EVALUAT & RES,1401 ROCKVILLE PIKE,ROCKVILLE,MD 20852, USA. RI Yu, Lee/N-7263-2015 OI Yu, Lee/0000-0002-8043-6853 NR 23 TC 6 Z9 9 U1 0 U2 0 PU ACADEMIC PRESS LTD PI LONDON PA 24-28 OVAL RD, LONDON, ENGLAND NW1 7DX SN 1045-1056 J9 BIOLOGICALS JI Biologicals PD JUN PY 1996 VL 24 IS 2 BP 87 EP 93 DI 10.1006/biol.1996.0011 PG 7 WC Biochemical Research Methods; Biotechnology & Applied Microbiology; Pharmacology & Pharmacy SC Biochemistry & Molecular Biology; Biotechnology & Applied Microbiology; Pharmacology & Pharmacy GA VH437 UT WOS:A1996VH43700002 PM 8889054 ER PT J AU Liebmann, B Smith, CA AF Liebmann, B Smith, CA TI Description of a complete (interpolated) outgoing longwave radiation dataset SO BULLETIN OF THE AMERICAN METEOROLOGICAL SOCIETY LA English DT Letter RP Liebmann, B (reprint author), UNIV COLORADO,COOPERAT INST RES ENVIRONM SCI,NOAA,ERL,CDC,BOULDER,CO 80309, USA. RI Smith, Catherine/H-5055-2016 OI Smith, Catherine/0000-0003-2687-6046 NR 2 TC 1245 Z9 1326 U1 4 U2 47 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 JUN PY 1996 VL 77 IS 6 BP 1275 EP 1277 PG 3 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA VC043 UT WOS:A1996VC04300013 ER PT J AU Orr, JW Baker, DC AF Orr, JW Baker, DC TI Southern range extension of the harlequin rockfish, Sebastes variegatus (Scorpaenidae) SO CALIFORNIA FISH AND GAME LA English DT Article RP Orr, JW (reprint author), NOAA,NATL MARINE FISHERIES SERV,ALASKA FISHERIES SCI CTR,SEATTLE,WA 98115, USA. NR 8 TC 0 Z9 0 U1 0 U2 0 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 SUM PY 1996 VL 82 IS 3 BP 133 EP 136 PG 4 WC Fisheries; Zoology SC Fisheries; Zoology GA WQ696 UT WOS:A1996WQ69600003 ER PT J AU Hsieh, WW Bryan, K AF Hsieh, WW Bryan, K TI Redistribution of sea level rise associated with enhanced greenhouse warming: A simple model study SO CLIMATE DYNAMICS LA English DT Article ID BUOYANCY FORCES; KELVIN WAVES; ADJUSTMENT; OCEAN; CHANNEL AB Future sea level rise from thermal expansion of the World Ocean due to global warming has been explored in several recent studies using coupled ocean-atmosphere models. These coupled models show that the heat input by the model atmosphere to the ocean in such an event could be quite non-uniform in different areas of the ocean. One of the most significant effects predicted by some of the models is a weakening of the thermohaline circulation, which normally transports heat poleward. Since the greatest heat input from enhanced greenhouse warming is in the higher latitudes, a weakening of the poleward heat transport effectively redistributes the heat anomaly and the associated sea level rise to lower latitudes. In this study, the mechanism of ocean circulation spindown and heat redistribution was studied in the context of a much simpler, linearized shallow water model. Although the model is much simpler than the three-dimensional ocean circulation models used in the coupled model experiments, and neglects several important physical effects, it has a nearly 10-fold increase in horizontal resolution and clearer dynamical interpretations. The results indicated that advanced signals of sea level rise propagated rapidly through the action of Kelvin and Rossby waves, but the full adjustment toward a more uniform sea level rise took place much more slowly. Long time scales were required to redistribute mass through narrow currents trapped along coasts and the equatorial wave guide. For realistic greenhouse warming, the model showed why the sea level rise due to ocean heating could be far from uniform over the globe and hence difficult to estimate from coastal tide gauge stations. C1 NOAA,GFDL,PRINCETON,NJ 08540. RP Hsieh, WW (reprint author), UNIV BRITISH COLUMBIA,DEPT OCEANOG,VANCOUVER,BC V6T 1Z4,CANADA. RI Hsieh, William/G-8380-2011 OI Hsieh, William/0000-0003-2654-392X NR 17 TC 26 Z9 27 U1 0 U2 3 PU SPRINGER VERLAG PI NEW YORK PA 175 FIFTH AVE, NEW YORK, NY 10010 SN 0930-7575 J9 CLIM DYNAM JI Clim. Dyn. PD JUN PY 1996 VL 12 IS 8 BP 535 EP 544 DI 10.1007/s003820050126 PG 10 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA UV500 UT WOS:A1996UV50000003 ER PT J AU Bryan, K AF Bryan, K TI The steric component of sea level rise associated with enhanced greenhouse warming: A model study SO CLIMATE DYNAMICS LA English DT Article ID OCEAN-ATMOSPHERE MODEL; SIMULATIONS; CO2 AB Climate change due to enhanced greenhouse warming has been calculated using the coupled GFDL general circulation model of the atmosphere and ocean. The results of the model for a sustained increase of atmospheric carbon dioxide of 1% per year over a century indicate a marked warming of the upper ocean. Results of the model are used to study the rise in sea level caused by increase in ocean temperatures and associated changes in ocean circulation. Neglecting possible contributions due to changes in the volume of polar ice sheets and mountain glaciers, the model predicts an average rise in sea level of approximately 15 +/- 5 cm by the time atmospheric carbon dioxide doubles. Heating anomalies are greatest in subpolar latitudes. This effect leads to a weakening of the ocean thermohaline circulation. Changes in thermohaline circulation redistribute heat within the ocean from high latitudes toward the equator, and cause a more uniform sea level rise than would occur otherwise. RP Bryan, K (reprint author), PRINCETON UNIV,PROGRAM ATMOSPHER & OCEAN SCI,SAYRE HALL,PRINCETON,NJ 08544, USA. NR 30 TC 31 Z9 31 U1 0 U2 4 PU SPRINGER VERLAG PI NEW YORK PA 175 FIFTH AVE, NEW YORK, NY 10010 SN 0930-7575 J9 CLIM DYNAM JI Clim. Dyn. PD JUN PY 1996 VL 12 IS 8 BP 545 EP 555 DI 10.1007/BF00207938 PG 11 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA UV500 UT WOS:A1996UV50000004 ER PT J AU Benfield, MC Minello, TJ AF Benfield, MC Minello, TJ TI Relative effects of turbidity and light intensity on reactive distance and feeding of an estuarine fish SO ENVIRONMENTAL BIOLOGY OF FISHES LA English DT Article DE vision; shading; scattering; predation; Fundulus grandis; Palaemonetes pugio ID RAINBOW-TROUT; PREY; PREDATION; BEHAVIOR; MODEL; RATES AB Gulf killifish Fundulus grandis were allowed to prey on daggerblade grass shrimp Palaemonetes pugio in clear water with bright light, turbid water containing bentonite clay, and clear water treatments where the light intensity was adjusted to match that in the bottom of the turbid tanks. Significantly fewer shrimp were consumed in the turbid tanks relative to the clear and shade treatments where predation rates did not differ significantly. The results suggested that the influence of suspended particles on predation rates was a consequence of light scattering and was not related to a decrease in light intensity. Reactive distances were subsequently determined for human observers viewing a small target in elongated tanks containing turbid water (7.3-60.5 NTU) under conditions of both low (8-10 mu E m(-2) s(-1)) and high illumination (153-1249 mu E m(-2) s(-1)).). Reactive distance was primarily governed by turbidity while light intensity had little influence except at low turbidities. The shape of the relationship between reactive distance and turbidity for humans resembled curves reported for a variety of fish species. C1 SE FISHERIES CTR, NATL MARINE FISHERIES SERV, GALVESTON, TX 77551 USA. RP Benfield, MC (reprint author), WOODS HOLE OCEANOG INST, DEPT BIOL, WOODS HOLE, MA 02543 USA. NR 25 TC 77 Z9 80 U1 5 U2 34 PU SPRINGER PI NEW YORK PA 233 SPRING ST, NEW YORK, NY 10013 USA SN 0378-1909 J9 ENVIRON BIOL FISH JI Environ. Biol. Fishes PD JUN PY 1996 VL 46 IS 2 BP 211 EP 216 DI 10.1007/BF00005223 PG 6 WC Ecology; Marine & Freshwater Biology SC Environmental Sciences & Ecology; Marine & Freshwater Biology GA UV974 UT WOS:A1996UV97400011 ER PT J AU Baird, RC AF Baird, RC TI Toward new paradigms in coastal resource management: Linkages and institutional effectiveness SO ESTUARIES LA English DT Article; Proceedings Paper CT 1st Marine and Estuarine Shallow Water Science and Management Conference CY MAR 08-11, 1994 CL ATLANTIC CITY, NJ ID UNITED-STATES; PROGRAM AB Explosive population growth is expected to continue in coastal regions, and growth rates many times the national average are expected in many coastal counties in the next two decades. Most shadow-water marine habitats now exhibit ''stress'' from human activities and linkages between adverse environmental impacts and coastal development are apparent. These linkages are complex, often not well understood, yet are expected to increase in strength as coastal populations expand. Sound science-based management strategies are essential if we are to preclude continued deterioration of coastal environments, Environmental management is a politically mediated activity, however, and a broad array of organizations, both public and private, collectively determine societal response to management decisions. While our current regulatory infrastructure has an exemplary record of achievement in environmental protection, the bet remains that adverse impacts to shallow-water marine habitats continue at significant rates. Both lack of scientific information and structural problems in our current institutional infrastructure are identified as impediments to better management performance for coastal habitats. Seven structural impediments to efficient science-based management in our current institutional infrastructure are identified. The issues are complex and comprehensive reform is politically difficult. Nonetheless, the magnitude, geographic scale, and temporal urgency of anticipated impacts from future growth and development scenarios argues strongly for the implementation of sound practical solutions to environmental protection on a sustained basis. Factors affecting management performance will also be amplified in an environment of limited investment in research and management infrastructure. Among the central themes are that science-based management practices in the future will require holistic approaches in which environment and economic development are inseparable. To work effectively large-scale, regional management schemes must build political consensus and integrate knowledge at unprecedented rates. Processes that increase rates of dissemination of scientific information into the public policy arena can significantly enhance management performance. Serious doubts are raised as to whether the current regulatory infrastructure can adequately respond to the complexity, scale, and urgency future coastal management will demand. White comprehensive institutional reform will be difficult, a number of ideas are advanced in the context of improving institutional performance to a level necessary for large-scale, sustained management of coastal ecosystems. RP Baird, RC (reprint author), NOAA,NATL SEA GRANT COLL PROGRAM,1315 EAST WEST HIGHWAY,ROOM 11716,SILVER SPRING,MD 20910, USA. NR 75 TC 10 Z9 10 U1 2 U2 3 PU ESTUARINE RES FEDERATION PI LAWRENCE PA PO BOX 368, LAWRENCE, KS 66044 SN 0160-8347 J9 ESTUARIES JI Estuaries PD JUN PY 1996 VL 19 IS 2A BP 320 EP 335 DI 10.2307/1352238 PG 16 WC Environmental Sciences; Marine & Freshwater Biology SC Environmental Sciences & Ecology; Marine & Freshwater Biology GA UX176 UT WOS:A1996UX17600017 ER PT J AU Bricker, SB Stevenson, JC AF Bricker, SB Stevenson, JC TI Nutrients in coastal waters: A chronology and synopsis of research SO ESTUARIES LA English DT Article ID SUBMERSED AQUATIC VEGETATION; QUALITY C1 UNIV MARYLAND,HORN POINT ENVIRONM LAB,CTR ENVIRONM & ESTUARINE STUDIES,CAMBRIDGE,MD 21613. RP Bricker, SB (reprint author), NOAA,OFF OCEAN RESOURCES CONSERVAT & ASSESSMENT,STRATEG ENVIRONM ASSESSMENTS DIV,SILVER SPRING,MD 20910, USA. NR 17 TC 17 Z9 17 U1 0 U2 4 PU ESTUARINE RES FEDERATION PI LAWRENCE PA PO BOX 368, LAWRENCE, KS 66044 SN 0160-8347 J9 ESTUARIES JI Estuaries PD JUN PY 1996 VL 19 IS 2B BP 337 EP 341 DI 10.2307/1352454 PG 5 WC Environmental Sciences; Marine & Freshwater Biology SC Environmental Sciences & Ecology; Marine & Freshwater Biology GA UX177 UT WOS:A1996UX17700001 ER PT J AU Polovina, JJ AF Polovina, JJ TI Decadal variation in the trans Pacific migration of northern bluefin tuna (Thunnus thynnus) coherent with climate induced change in prey abundance SO FISHERIES OCEANOGRAPHY LA English DT Article DE bluefin tuna; migration; climate change; prey abundance; North Pacific; Japanese sardine AB Northern bluefin tuna, Thunnus thynnus, apparently spawn only in the western Pacific and a portion of the juveniles migrate to the eastern Pacific. During the past decade, catches of northern bluefin in the eastern Pacific have declined. One possible cause for this decline, proposed by bluefin stock assessment studies, is a decline in the proportion of bluefin that migrate out of the western Pacific. This hypothesis is examined with several indices of the relative abundance of bluefin tuna in the western and eastern Pacific. These indices suggest a decline in the proportion of bluefin migrating to the eastern Pacific since 1977. This period of reduced bluefin migration coincides with a period when a prey of bluefin, Japanese sardine, Sardinops melanosticta, were abundant off Japan. It is hypothesized that in years when sardines are abundant off Japan, a higher proportion of bluefin stay in the western Pacific compared with years when sardines are scarce. Currently, the abundance of sardines off Japan is declining. If this decline continues, this hypothesis predicts an increase in bluefin migrating north of Hawaii and into the eastern Pacific. RP Polovina, JJ (reprint author), NOAA,HONOLULU LAB,SW FISHERIES CTR,NMFS,2570 DOLE ST,HONOLULU,HI 96822, USA. NR 17 TC 58 Z9 62 U1 3 U2 20 PU BLACKWELL SCIENCE LTD PI OXFORD PA OSNEY MEAD, OXFORD, OXON, ENGLAND OX2 0EL SN 1054-6006 J9 FISH OCEANOGR JI Fish Oceanogr. PD JUN PY 1996 VL 5 IS 2 BP 114 EP 119 DI 10.1111/j.1365-2419.1996.tb00110.x PG 6 WC Fisheries; Oceanography SC Fisheries; Oceanography GA UT343 UT WOS:A1996UT34300004 ER PT J AU Peng, YG Ramsdell, JS AF Peng, YG Ramsdell, JS TI Brain Fos induction is a sensitive biomarker for the lowest observed neuroexcitatory effects of domoic acid SO FUNDAMENTAL AND APPLIED TOXICOLOGY LA English DT Article ID KAINIC ACID; RAT-BRAIN; HIGH-AFFINITY; AMINO-ACID; C-FOS; GLUTAMATE; NEUROTOXICITY; EXPRESSION; DOMOATE; RECEPTORS AB Domoic acid induces Fos in several brain regions controlling memory processing and gastrointestinal functions. Pn the present study, we determined serum levels of domoic acid that caused observable effects, and examined whether brain c-Sos was a sensitive marker for the lowest observed neuroexcitatory effects in mice. Five different doses (0.25 to 4.0 mg/kg) of domoic acid were intraperitoneally administered Co mice, and the serum concentration of domoic acid was monitored using a radioreceptor assay. The earliest neuroexcitatory effect of domoic acid on behavior was observed in the form of hyperactivity which occurred at 0.5 mg/kg (0.076 +/- 0.02 mu g/ml serum domoic acid, mean +/- SE, n = 5). However, stereotypic behavior (scratching) was observed only at doses greater than or equal to 1.0 mg/kg (0.25 +/- 0.02 mu g/ml). At 2.0 mg/kg (0.54 +/- 0.04 mu g/ml) and higher, convulsions and seizures occurred. Domoic acid induction of c-fos mRNA was detected in the whole brain at 1.0 mg/kg, whereas increased Fos immunostaining was localized in the dentate granule cells and the pyramidal cells of hippocampal formation at doses as low as 0.5 mg/kg (0.076 +/- 0.02 mu g/ml). Our results indicate that Fos expression in the hippocampus is a sensitive biomarker for the neuroexcitatory effects of domoic acid, being induced at doses of domoic acid lower than those that elicit stereotypic behavior. (C) 1996 Society of Toxicology. RP Peng, YG (reprint author), MED UNIV S CAROLINA,US NATL MARINE FISHERIES SERV & MARINE BIOMED & E,MAINE BIOTOXINS PROGRAM,CHARLESTON,SC 29412, USA. FU NIDDK NIH HHS [DK43107] NR 30 TC 42 Z9 49 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 0272-0590 J9 FUND APPL TOXICOL JI Fundam. Appl. Toxicol. PD JUN PY 1996 VL 31 IS 2 BP 162 EP 168 DI 10.1006/faat.1996.0087 PG 7 WC Toxicology SC Toxicology GA UQ840 UT WOS:A1996UQ84000003 PM 8789781 ER PT J AU Heffter, JL AF Heffter, JL TI Volcanic ash model verification using a Klyuchevskoi eruption SO GEOPHYSICAL RESEARCH LETTERS LA English DT Article AB Satellite imagery of volcanic ash is used to verify the Air Resources Laboratory (ARL) time dependent three dimensional Volcanic Ash Forecast Transport And Dispersion (VAFTAD) model. VAFTAD forecasts are included in volcano hazards alert messages issued as an aid to aircraft operations for ash clouds that reach flight levels of 6 Irm or higher and may drift hundreds to thousands of kilometers from an explosive volcanic eruption. VAFTAD is run by users connected through Internet to a workstation at ART, using screen-prompted input, and is applicable globally. Model output gives charts of the forecast ash cloud which are phone-faxed back to the user and made available for public distribution over various weather information distribution systems and Internet. Volcanic ash model verification is essential for interpreting ash cloud forecasts and applying them for decision-making. The VAFTAD model verification is detailed using a September 1994 eruption of the Klyuchevskoi Volcano on Kamchatka Peninsula in eastern Russia. Both the downwind extent of the ash cloud along the main flow axis and the ash cloud width perpendicular to the main flow axis, seen on satellite imagery, compared remarkably well with the VAFTAD calculations that used eruption source information and archived meteorological analyses as model input. RP Heffter, JL (reprint author), NOAA,AIR RESOURCES LAB,1315 EAST WEST HWY,SSM3,RM 3357,SILVER SPRING,MD 20910, USA. NR 14 TC 9 Z9 9 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 JUN 1 PY 1996 VL 23 IS 12 BP 1489 EP 1492 DI 10.1029/96GL01270 PG 4 WC Geosciences, Multidisciplinary SC Geology GA UP857 UT WOS:A1996UP85700010 ER PT J AU Hofmann, DJ Oltmans, SJ Koenig, GL Bodhaine, BA Harris, JM Lathrop, JA Schnell, RC Barnes, J Chin, J Kuniyuki, D Ryan, S Uchida, R Yoshinaga, A Neale, PJ Hayes, DR Goodrich, VR Komhyr, WD Evans, RD Johnson, BJ Quincy, DM Clark, M AF Hofmann, DJ Oltmans, SJ Koenig, GL Bodhaine, BA Harris, JM Lathrop, JA Schnell, RC Barnes, J Chin, J Kuniyuki, D Ryan, S Uchida, R Yoshinaga, A Neale, PJ Hayes, DR Goodrich, VR Komhyr, WD Evans, RD Johnson, BJ Quincy, DM Clark, M TI Record low ozone at Mauna Loa observatory during winter 1994-1995: A consequence of chemical and dynamical synergism? SO GEOPHYSICAL RESEARCH LETTERS LA English DT Article ID STRATOSPHERIC CIRCULATION; ERUPTION; PINATUBO AB During two days in late December 1994, total ozone measured at the Mauna Loa Observatory on the island of Hawaii, dropped below 200 Dobson Units (DU) for the first time since ozone measurements began at this site over 30 years ago. Total ozone values this low have not previously occurred over populated areas except on rare occasions when the edges of the springtime Antarctic ozone hole temporarily pass over the southern tip of Argentina. The monthly total ozone average for January 1995 was 216 DU, about 14 % below the 1964-1981 baseline value. Ultraviolet radiation measured at Mauna Loa on clear days during this period increased inversely with ozone as expected, more than tripling in relative intensity at 295 MI. The normal annual minimum in total ozone occurs in winter at Mauna Loa; however, some winters experience considerably lower values than others. This was the case during the winter of 1994-1995. Although the general decline in global ozone, which began about 1980 and also appears in the Mauna Loa record, may he related to chemical ozone depletion, the unusually low values during some winters at Mauna Loa appear to be related to ozone transport from the tropics, and the timing of phase transitions of the QBO. This analysis provides an accurate method of forecasting low-ozone, high-UV winters in Hawaii. C1 SMITHSONIAN ENVIRONM RES CTR,EDGEWATER,MD 21037. NOAA,CMDL,MAUNA LOA OBSERV,HILO,HI 96721. UNIV COLORADO,COOPERAT INST RES ENVIRONM SCI,BOULDER,CO 80309. RP Hofmann, DJ (reprint author), NOAA,CLIMATE MONITORING & DIAGNOST LAB,325 BROADWAY,BOULDER,CO 80303, USA. RI Neale, Patrick/A-3683-2012; Evans, Robert/D-4731-2016 OI Evans, Robert/0000-0002-8693-9769 NR 11 TC 9 Z9 9 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 JUN 1 PY 1996 VL 23 IS 12 BP 1533 EP 1536 DI 10.1029/96GL00150 PG 4 WC Geosciences, Multidisciplinary SC Geology GA UP857 UT WOS:A1996UP85700021 ER PT J AU Xue, YK Zeng, FJ Schlosser, CA AF Xue, YK Zeng, FJ Schlosser, CA TI SSiB and its sensitivity to soil properties - A case study using HAPEX-Mobilhy data SO GLOBAL AND PLANETARY CHANGE LA English DT Article; Proceedings Paper CT RICE and PILPS Moisture Workshop - Soil Moisture Simulation CY NOV, 1994 CL MACQUARIE UNIV, SYDNEY, AUSTRALIA SP Reg Interact Climate & Ecosyst, Proj Intercomparison Landsurface Parameterizat Schemes HO MACQUARIE UNIV ID SIMPLE BIOSPHERE MODEL; HYDRAULIC-PROPERTIES; MOISTURE AB In this paper, SSiB's development and some of its major parameterizations in the model are briefly reviewed. The soil moisture parameterizations, which are a key element in the model, are comprehensively described. The sensitivity study shows that hydraulic conductivity at saturation, B parameter, and wilting point have a profound impact on the simulation of soil moisture, but with different features. Both hydraulic conductivity at saturation and B parameter influence the soil moisture simulation by changing the soil hydraulic conductivity and the field capacity. The changes in equilibrium soil water content in this study are consistent with the changes in field capacity. The wilting point affects the soil moisture through vegetation transpiration. Through these sensitivity studies, improvements in modeling the soil moisture content of HAPEX-Mobilhy data are made. The soil moisture simulations at six Russian sites are also re-examined. After applying the results from the sensitivity studies of the HAPEX-Mobilhy data, the soil moisture simulation of the Russian data is significantly improved. C1 PRINCETON UNIV,NOAA,GEOPHYS FLUID DYNAM LAB,PRINCETON,NJ 08645. RP Xue, YK (reprint author), CTR OCEAN LAND ATMOSPHERE STUDIES,4041 POWDER MILL RD,SUITE 302,CALVERTON,MD 20705, USA. NR 31 TC 92 Z9 102 U1 1 U2 6 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0921-8181 J9 GLOBAL PLANET CHANGE JI Glob. Planet. Change PD JUN PY 1996 VL 13 IS 1-4 BP 183 EP 194 DI 10.1016/0921-8181(95)00045-3 PG 12 WC Geography, Physical; Geosciences, Multidisciplinary SC Physical Geography; Geology GA UT685 UT WOS:A1996UT68500013 ER PT J AU Johnson, JE Bates, TS AF Johnson, JE Bates, TS TI Sources and sinks of carbon monoxide in the mixed layer of the tropical South Pacific Ocean SO GLOBAL BIOGEOCHEMICAL CYCLES LA English DT Article ID DISSOLVED ORGANIC-CARBON; NATURAL-WATERS; SEA; CONSUMPTION; METHANE AB The magnitude of the oceanic source of carbon monoxide (CO) to the atmosphere depends on the concentration of CO in ocean surface waters. To ascertain the relative importance of the processes controlling this concentration, depth profiles of CO concentrations in the oceanic mixed layer and upper thermocline were made at two time series stations in the tropical Pacific Ocean during 1993. The two stations were chosen to contrast an oligotrophic region of low CO water concentrations (RITS93) with a biologically productive region of high seawater CO concentrations (RITS94). The column burden of CO in the upper 75 m of the water column averaged 53 mu mole m(-2) at the RITS93 station and 240 mu mole m(-2) at the RITS94 station. From the observed diurnal cycle of the CO column burden, production and loss rates at each site were estimated. The factor of 4.5 difference in the column burden is primarily due to a smaller in situ oxidation rate constant at the RITS94 site. C1 UNIV WASHINGTON,JOINT INST STUDY ATMOSPHERE & OCEANS,SEATTLE,WA 98195. RP Johnson, JE (reprint author), NOAA,PACIFIC MARINE ENVIRONM LAB,7600 SAND POINT WAY NE,BLDG 3,SEATTLE,WA 98115, USA. RI Bates, Timothy/L-6080-2016 NR 24 TC 45 Z9 48 U1 0 U2 8 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 SN 0886-6236 J9 GLOBAL BIOGEOCHEM CY JI Glob. Biogeochem. Cycle PD JUN PY 1996 VL 10 IS 2 BP 347 EP 359 DI 10.1029/96GB00366 PG 13 WC Environmental Sciences; Geosciences, Multidisciplinary; Meteorology & Atmospheric Sciences SC Environmental Sciences & Ecology; Geology; Meteorology & Atmospheric Sciences GA UP378 UT WOS:A1996UP37800012 ER PT J AU Baldocchi, D Valentini, R Running, S Oechel, W Dahlman, R AF Baldocchi, D Valentini, R Running, S Oechel, W Dahlman, R TI Strategies for measuring and modelling carbon dioxide and water vapour fluxes over terrestrial ecosystems SO GLOBAL CHANGE BIOLOGY LA English DT Article DE biogeochemistry; carbon balance; carbon dioxide; CO2 flux monitoring network; eddy covariance ID OPEN-PATH; CO2; FORESTS; HEAT; PHOTOSYNTHESIS; TRANSPIRATION; BIOSPHERE; SATELLITE; ANALYZER; INCREASE AB Continuous and direct measurements of ecosystem carbon dioxide and water vapour fluxes can improve our ability to close regional and global carbon and hydrological budgets. On this behalf, an international and multidisciplinary group of scientists (micrometeorologists, ecophysiologists and biogeochemists) assembled at La Thuile, Italy to convene a workshop on 'Strategies for Monitoring and Modelling CO2 and Water Vapour Fluxes over Terrestrial Ecosystems'. Over the course of the week talks and discussions focused on: (i) the results from recent field studies on the annual cycle of carbon dioxide and water vapour fluxes over terrestrial ecosystems; (ii) the problems and pitfalls associated with making long-term flux measurements; (iii) alternative methods for assessing ecosystem carbon dioxide and water vapour fluxes; (iv) how direct and continuous carbon dioxide and water vapour flux measurements could be used by the ecological and biogeochemical modelling communities; and (v) if,how and where to proceed with establishing a network of long-term flux measurement sites. This report discusses the purpose of the meeting and summarizes the conclusions drawn from the discussions by the attending scientists. There was a consensus that recent advances in instrumentation and software make possible long-term measurements of carbon dioxide and water vapour fluxes over terrestrial ecosystems. At this writing, eight research teams have conducted long-term carbon dioxide and water vapour flux experiments and more long-term studies are anticipated. The participants advocated an experimental design that would make longterm flux measurement valuable to a wider community of modelers, biogeochemists and ecologists. A network of carbon dioxide and water vapour flux measurement stations should include ancillary measurements of meteorological, ecological and biological variables. To assess spatial representativeness of the long term and tower-based flux measurements, periodic aircraft-based flux experiments and satellite-based assessments of land cover were recommended. Occasional cuvette-based measurements of leaf-level carbon dioxide and water vapour fluxes were endorsed to provide information on the biological control of surface fluxes. They can also provide data to parameterize ecophysiological models. Flask sampling of stable carbon isotopes was advocated to extend the flux measurements to the global scale. C1 UNIV TUSCIA,DEPT FOREST SCI & ENVIRONM DISAFRI,I-01100 VITERBO,ITALY. UNIV MONTANA,SCH FORESTRY,MISSOULA,MT 59812. SAN DIEGO STATE UNIV,DEPT BIOL,GLOBAL CHANGE RES GRP,SAN DIEGO,CA 92182. US DOE,DIV ENVIRONM SCI,WASHINGTON,DC 20545. RP Baldocchi, D (reprint author), NOAA,ATMOSPHER TURBULENCE & DIFFUS DIV,POB 2456,OAK RIDGE,TN 37831, USA. RI Baldocchi, Dennis/A-1625-2009; Oechel, Walter/F-9361-2010; Valentini, Riccardo/D-1226-2010 OI Baldocchi, Dennis/0000-0003-3496-4919; Oechel, Walter/0000-0002-3504-026X; Valentini, Riccardo/0000-0002-6756-5634 NR 32 TC 242 Z9 275 U1 4 U2 52 PU BLACKWELL SCIENCE LTD PI OXFORD PA OSNEY MEAD, OXFORD, OXON, ENGLAND OX2 0EL SN 1354-1013 J9 GLOB CHANGE BIOL JI Glob. Change Biol. PD JUN PY 1996 VL 2 IS 3 BP 159 EP 168 DI 10.1111/j.1365-2486.1996.tb00069.x PG 10 WC Biodiversity Conservation; Ecology; Environmental Sciences SC Biodiversity & Conservation; Environmental Sciences & Ecology GA UT344 UT WOS:A1996UT34400001 ER PT J AU Greco, S Baldocchi, DD AF Greco, S Baldocchi, DD TI Seasonal variations of CO2 and water vapour exchange rates over a temperate deciduous forest SO GLOBAL CHANGE BIOLOGY LA English DT Article DE biosphere-atmosphere interactions; carbon dioxide; CO2 fluxes; ecophysiology; eddy covariance; micrometeorology; temperate broadleaved forest ID NET PRIMARY PRODUCTIVITY; OAK-HICKORY FOREST; CARBON-DIOXIDE; TERRESTRIAL BIOSPHERE; LEAF CONDUCTANCE; ATMOSPHERIC CO2; GLOBAL-MODEL; PHOTOSYNTHESIS; PATTERNS; CANOPY AB Long-term and direct measurements of CO2 and water vapour exchange are needed over forested ecosystems to determine their net annual fluxes of carbon dioxide and water. Such measurements are also needed to parameterize and test biogeochemical, ecological and hydrological assessment models. Responding to this need, eddy covariance measurements of CO2 and water vapour were made over a deciduous forest growing near Oak Ridge, TN, between April 1993 and April 1994. Periodic measurements were made of leaf area index, stomal resistance, soil moisture and pre-dawn leaf water potential to characterize the gas exchange capacity of the canopy. Four factors had a disproportionate influence on the seasonal variation of CO2 flux densities. These factors were photon flux densities (during the growing season), temperature (during the dormant season), leaf area index and the occurrence of drought. The drought period occurred during the peak of the growing season and caused a significant decline in daily and hourly CO2 flux densities, relative to observations over the stand when soil moisture was plentiful. The annual net uptake of carbon was calculated by integrating flux measurements and filling missing and spurious data with the relations obtained between measured CO2 fluxes and environmental forcing variables. The net flux of carbon for the period between April 1993 and April 1994 was -525 g C m(-2) y(-1). This value represents a net flux of carbon from the atmosphere and into the forest. The net annual carbon exchange of this southern temperate broadleaved forest exceeded values measured over a northern temperate forest (which experiences a shorter growing season and has less leaf area) by 200 g C m(-2) y(-1) (cf. Wofsy et al. 1993). The seasonal variation of canopy evaporation (latent heat flux) was controlled mostly by changes in leaf area and net radiation. A strong depression in evaporation rates was not observed during the drought. Over a broadleaved forest, large vapour pressure deficits promote evaporation and trees in a mixed stand are able to tap a variety of deep and shallow water sources. C1 NOAA,ATMOSPHERIC TURBULENCE & DIFFUSION DIV,OAK RIDGE,TN 37831. UNIV TUSCIA,DEPT FOREST SCI & ENVIRONM,I-01100 VITERBO,ITALY. RI Baldocchi, Dennis/A-1625-2009 OI Baldocchi, Dennis/0000-0003-3496-4919 NR 47 TC 203 Z9 231 U1 4 U2 44 PU BLACKWELL SCIENCE LTD PI OXFORD PA OSNEY MEAD, OXFORD, OXON, ENGLAND OX2 0EL SN 1354-1013 J9 GLOB CHANGE BIOL JI Glob. Change Biol. PD JUN PY 1996 VL 2 IS 3 BP 183 EP 197 DI 10.1111/j.1365-2486.1996.tb00071.x PG 15 WC Biodiversity Conservation; Ecology; Environmental Sciences SC Biodiversity & Conservation; Environmental Sciences & Ecology GA UT344 UT WOS:A1996UT34400003 ER PT J AU Crawford, TL Dobosy, RJ McMillen, RT Vogel, CA Hicks, BB AF Crawford, TL Dobosy, RJ McMillen, RT Vogel, CA Hicks, BB TI Air-surface exchange measurement in heterogeneous regions: Extending tower observations with spatial structure observed from small aircraft SO GLOBAL CHANGE BIOLOGY LA English DT Article DE air-surface exchange; aircraft; atmosphere; flux; inhomogeneous; measurement ID FLUX MEASUREMENTS; BOUNDARY-LAYER; CARBON-DIOXIDE; SENSIBLE HEAT; WATER-VAPOR; TURBULENCE; PROBE; OZONE; SEA AB Strategies to assess long-term atmosphere-ecosystem exchange of CO2 and H2O must deal not only with time trends but also with spatial variability. Flux towers efficiently measure time trends, but only at discrete sites, always limited in number. Representativeness of these sites and the causes of spatial variation between sites are difficult to investigate from tower data alone. Such issues are better addressed with flux measurements from moving vehicles, particularly aircraft. Recent technological advancements in aircraft and instrumentation now allow mobile flux measurement with enhanced precision, greater ease, and lower cost. Results are presented which illustrate the importance of spatial variability, and some suggestions are given for assessment of flux-tower representativeness. Unfortunately, airborne observations of the kind presented here are practical only during a part of the daylight hours in brief intensive field campaigns. Extrapolation of spatial-structure information derived from these measurements to night-time or to long-term averages thus remains problematic. For the foreseeable future this extrapolation will require models that faithfully simulate both space and time characteristics of H2O and CO2 exchange. The development and validation of such models will be greatly enhanced by the increased availability of measurements from moving vehicles, which record spatial as well as temporal structure. C1 OAK RIDGE ASSOCIATED UNIV,OAK RIDGE,TN 37830. NOAA,AIR RESOURCES LAB,ATMOSPHER TURBULENCE & DIFFUS DIV,OAK RIDGE,TN 37831. NOAA,AIR RESOURCES LAB,SILVER SPRING,MD 20910. RI Dobosy, Ronald/C-3303-2016 OI Dobosy, Ronald/0000-0001-8399-8774 NR 41 TC 28 Z9 29 U1 3 U2 9 PU BLACKWELL SCIENCE LTD PI OXFORD PA OSNEY MEAD, OXFORD, OXON, ENGLAND OX2 0EL SN 1354-1013 J9 GLOB CHANGE BIOL JI Glob. Change Biol. PD JUN PY 1996 VL 2 IS 3 BP 275 EP 285 DI 10.1111/j.1365-2486.1996.tb00079.x PG 11 WC Biodiversity Conservation; Ecology; Environmental Sciences SC Biodiversity & Conservation; Environmental Sciences & Ecology GA UT344 UT WOS:A1996UT34400011 ER PT J AU Tans, PP Bakwin, PS Guenther, DW AF Tans, PP Bakwin, PS Guenther, DW TI A feasible global carbon cycle observing system: A plan to decipher today's carbon cycle based on observations SO GLOBAL CHANGE BIOLOGY LA English DT Article DE carbon cycle; carbon dioxide; global change; methane; trace gas exchange; trace gas monitoring ID ATMOSPHERIC METHANE; AMAZON BASIN; GROWTH-RATE; MONOXIDE; FOREST AB A design is presented to continuously monitor the transfers of carbon between the atmosphere and the terrestrial biosphere and oceans on large spatial scales. A consideration of the expected signal-to-noise suggests that a very cost effective method is to perform repeated measurements of the mixing ratios of trace gases in the atmospheric column at an increased number of sites compared to the present geographical coverage, This can be accomplished with existing technology, provided that more automation is applied to the sampling process as well as to the analytical procedures. The resulting data will be crucial to test extrapolations based on direct flux measurements to regional and global scales. C1 NOAA,ERL,R E CG1,BOULDER,CO 80303. NOAA,CLIMATE MONITORING & DIAGNOST LAB,CARBON CYCLE GRP,BOULDER,CO 80303. UNIV COLORADO,COOPERAT INST RES ENVIRONM SCI,BOULDER,CO 80309. NR 27 TC 63 Z9 69 U1 0 U2 9 PU BLACKWELL SCIENCE LTD PI OXFORD PA OSNEY MEAD, OXFORD, OXON, ENGLAND OX2 0EL SN 1354-1013 J9 GLOB CHANGE BIOL JI Glob. Change Biol. PD JUN PY 1996 VL 2 IS 3 BP 309 EP 318 DI 10.1111/j.1365-2486.1996.tb00082.x PG 10 WC Biodiversity Conservation; Ecology; Environmental Sciences SC Biodiversity & Conservation; Environmental Sciences & Ecology GA UT344 UT WOS:A1996UT34400014 ER PT J AU Engel, DW Vaughan, DS AF Engel, DW Vaughan, DS TI Biomarkers, natural variability, and risk assessment: Can they coexist? SO HUMAN AND ECOLOGICAL RISK ASSESSMENT LA English DT Article DE biomarkers; ecological risk assessment; variability; population; ecosystem ID CALLINECTES-SAPIDUS; METAL REGULATION; BLUE-CRAB; METALLOTHIONEIN; COPPER AB This paper is a discussion of the utility of biomarkers as a component of the ecological risk assessment process. Both the pros and the cons of biomarkers are discussed, as well as consideration of some of the sources of variability. In the end, biomarkers are considered useful as long as we are aware of their limitations and sources of uncontrolled variability. C1 NOAA,NATL MARINE FISHERIES SERV,BEAUFORT LAB,BEAUFORT,NC. NR 14 TC 7 Z9 7 U1 0 U2 0 PU CRC PRESS INC PI BOCA RATON PA 2000 CORPORATE BLVD NW, JOURNALS CUSTOMER SERVICE, BOCA RATON, FL 33431 SN 1080-7039 J9 HUM ECOL RISK ASSESS JI Hum. Ecol. Risk Assess. PD JUN PY 1996 VL 2 IS 2 BP 257 EP 262 PG 6 WC Biodiversity Conservation; Environmental Sciences SC Biodiversity & Conservation; Environmental Sciences & Ecology GA WC991 UT WOS:A1996WC99100007 ER PT J AU Menzie, C Henning, MH Cura, J Finkelstein, K Gentile, J Maughan, J Mitchell, D Petron, S Potocki, B Svirsky, S Tyler, P AF Menzie, C Henning, MH Cura, J Finkelstein, K Gentile, J Maughan, J Mitchell, D Petron, S Potocki, B Svirsky, S Tyler, P TI Report of the Massachusetts weight-of-evidence workgroup: A weight-of-evidence approach for evaluating ecological risks SO HUMAN AND ECOLOGICAL RISK ASSESSMENT LA English DT Article DE weight-of-evidence; ecological risk assessment; assessment endpoints; measurement endpoints AB Weight-of-evidence is the process by which multiple measurement endpoints are related to an assessment endpoint to evaluate whether significant risk of harm is posed to the environment. In this paper, a methodology is offered for reconciling or balancing multiple lines of evidence pertaining to an assessment endpoint. Weight-of-evidence is reflected in three characteristics of measurement endpoints: (a) the weight assigned to each measurement endpoint; (b) the magnitude of response observed in the measurement endpoint; and (c) the concurrence among outcomes of multiple measurement endpoints. First, weights are assigned to measurement endpoints based on attributes related to: (a) strength of association between assessment and measurement endpoints; (b) data quality; and (c) study design and execution. Second, the magnitude of response in the measurement endpoint is evaluated with respect to whether the measurement endpoint indicates the presence or absence of harm; as well as the magnitude. Third, concurrence among measurement endpoints is evaluated by plotting the findings of the two preceding steps on a matrix for each measurement endpoint evaluated. The matrix allows easy visual examination of agreements or divergences among measurement endpoints, facilitating interpretation of the collection of measurement endpoints with respect to the assessment endpoint. A qualitative adaptation of the weight-of-evidence approach is also presented. C1 MCLAREN HART,CHEMRISK,PORTLAND,ME. NOAA,BOSTON,MA. UNIV MIAMI,MIAMI,FL 33152. CH2M HILL INC,BOSTON,MA. ENSR CONSULTING & ENGN,ACTON,MA. PTI,WALTHAM,MA. US EPA,BOSTON,MA. US EPA,LEXINGTON,MA. RP Menzie, C (reprint author), MENZIE CURA & ASSOCIATES,1 COURTHOUSE LANE,CHELMSFORD,MA 01824, USA. NR 3 TC 61 Z9 68 U1 2 U2 7 PU CRC PRESS INC PI BOCA RATON PA 2000 CORPORATE BLVD NW, JOURNALS CUSTOMER SERVICE, BOCA RATON, FL 33431 SN 1080-7039 J9 HUM ECOL RISK ASSESS JI Hum. Ecol. Risk Assess. PD JUN PY 1996 VL 2 IS 2 BP 277 EP 304 PG 28 WC Biodiversity Conservation; Environmental Sciences SC Biodiversity & Conservation; Environmental Sciences & Ecology GA WC991 UT WOS:A1996WC99100011 ER PT J AU Beichl, I Sullivan, F AF Beichl, I Sullivan, F TI A heap of data SO IEEE COMPUTATIONAL SCIENCE & ENGINEERING LA English DT Article C1 IDA CTR COMP SCI,BOWIE,MD. RP Beichl, I (reprint author), NIST,COMP & APPL MATH LAB,GAITHERSBURG,MD 20899, USA. NR 1 TC 1 Z9 1 U1 0 U2 0 PU IEEE COMPUTER SOC PI LOS ALAMITOS PA 10662 LOS VAQUEROS CIRCLE, PO BOX 3014, LOS ALAMITOS, CA 90720-1264 SN 1070-9924 J9 IEEE COMPUT SCI ENG JI IEEE Comput. Sci. Eng. PD SUM PY 1996 VL 3 IS 2 BP 11 EP 14 DI 10.1109/99.503322 PG 4 WC Computer Science, Theory & Methods; Engineering, Electrical & Electronic; Mathematics, Applied SC Computer Science; Engineering; Mathematics GA UR190 UT WOS:A1996UR19000010 ER PT J AU Garris, MD Dimmick, DL AF Garris, MD Dimmick, DL TI Form design for high accuracy optical character recognition SO IEEE TRANSACTIONS ON PATTERN ANALYSIS AND MACHINE INTELLIGENCE LA English DT Article DE form design; forms processing; handwriting recognition; idiosyncratic responses; neural networks; optical character recognition; tax AB To successfully apply character recognition technology most of the forms currently hand-keyed will need to be redesigned. This paper presents results from a comprehensive study of three versions of a redesigned tax form. Analyses show that using separately spaced character boxes provides superior machine readability over fields containing combs and adjoining character boxes. It is shown that character boxes containing two vertically stacked ovals cause writers much more difficulty. Analyses provide proof that writer idiosyncratic responses on forms are the major source of errors, and proper form design can reduce these errors. RP Garris, MD (reprint author), NATL INST STAND & TECHNOL,GAITHERSBURG,MD 20899, USA. NR 10 TC 5 Z9 5 U1 0 U2 0 PU IEEE COMPUTER SOC PI LOS ALAMITOS PA 10662 LOS VAQUEROS CIRCLE, PO BOX 3014, LOS ALAMITOS, CA 90720-1264 SN 0162-8828 J9 IEEE T PATTERN ANAL JI IEEE Trans. Pattern Anal. Mach. Intell. PD JUN PY 1996 VL 18 IS 6 BP 653 EP 656 DI 10.1109/34.506417 PG 4 WC Computer Science, Artificial Intelligence; Engineering, Electrical & Electronic SC Computer Science; Engineering GA UR254 UT WOS:A1996UR25400010 ER PT J AU Lansari, A Streicher, JJ Huber, AH Crescenti, GH Zweidinger, RB Duncan, JW Weisel, CP Burton, RM AF Lansari, A Streicher, JJ Huber, AH Crescenti, GH Zweidinger, RB Duncan, JW Weisel, CP Burton, RM TI Dispersion of automotive alternative fuel vapors within a residence and its attached garage SO INDOOR AIR-INTERNATIONAL JOURNAL OF INDOOR AIR QUALITY AND CLIMATE LA English DT Article DE indoor air; multizonal models; mass balance models; methanol; air pollution; attached garage ID EMISSIONS AB A study was undertaken to investigate the use of mass balance modeling techniques to predict air pollution concentrations in residential settings where the source is evaporative emissions of alternative fuels emitted in the attached garage. Field study measurements of the spatial and temporal distribution of evaporative emissions in an attached garage were used to conduct this investigation, In this field study, known quantities of methanol were allowed to evaporate in the garage. Methanol concentrations were then measured and simulated in the garage. Because chemical and physical properties of this contaminant are clearly understood, if was possible to simulate the concentrations inside the remainder oi the house. A multi-zonal mass balance model (CONTAM88) was used to predict the across-residence spatial and temporal distribution of concentrations of evaporative emissions from a methanol source inside the attached garage. The model's input data include physical characteristics of the house; parameters characterizing the leakiness of the house; heat, ventilation and air-conditioning system characteristics; fixed airflow data from vent registers; on-site meteorological measurements; and information on the contaminant source. Before using the model to simulate methanol dispersions, the model's performance was tested. Sulfur hexafluoride (SF6) measurements were taken throughout the residence and garage. The model tvas used to predict interzonal airflow rates and SF6 concentration distributions within the garage and the house, as well as to investigate the well-mixed zone assumption for the garage. Modeling results show that predicted garage SF6 concentrations agreed reasonably well with the measured concentrations under mixed conditions, but the model underpredicted the SF6 concentrations within rooms of the house ih hare mixing was probably incomplete. Methanol simulation results showed that the model underpredicted by approximately 15 percent the garage methanol concentration after methanal emissions stopped. This study found that evaporative emissions in an attached garage have a tendency to infiltrate the house, with rooms adjacent to the garage showing the highest levels of methanol concentrations. Thus automotive evaporative Emissions may represent a source of indoor pollution and human exposure in a residential attached garage and also in other critical locations of the residence. C1 NOAA,DIV ATMOSPHER SCI MODELING,AIR RESOURCES LAB,RES TRIANGLE PK,NC 27711. US EPA,NATL EXPOSURE RES LAB,MOBILE SOURCE EMISS RES BRANCH,RES TRIANGLE PK,NC 27711. ENVIRONM & OCCUPAT HLTH SCI INST,PISCATAWAY,NJ 08855. US EPA,NATL EXPOSURE RES LAB,EXPOSURE ASSESSMENT BRANCH,RES TRIANGLE PK,NC 27711. RP Lansari, A (reprint author), MANTECH ENVIRONM TECHNOL INC,POB 12313,RES TRIANGLE PK,NC 27709, USA. NR 14 TC 15 Z9 15 U1 0 U2 3 PU MUNKSGAARD INT PUBL LTD PI COPENHAGEN PA 35 NORRE SOGADE, PO BOX 2148, DK-1016 COPENHAGEN, DENMARK SN 0905-6947 J9 INDOOR AIR JI Indoor Air-Int. J. Indoor Air Qual. Clim. PD JUN PY 1996 VL 6 IS 2 BP 118 EP 126 DI 10.1111/j.1600-0668.1996.t01-1-00008.x PG 9 WC Construction & Building Technology; Engineering, Environmental; Public, Environmental & Occupational Health SC Construction & Building Technology; Engineering; Public, Environmental & Occupational Health GA VN945 UT WOS:A1996VN94500008 ER PT J AU Zhang, ZM Hanssen, LM Datla, RU AF Zhang, ZM Hanssen, LM Datla, RU TI Polarization-dependent angular reflectance of silicon and germanium in the infrared SO INFRARED PHYSICS & TECHNOLOGY LA English DT Article DE infrared; oblique incidence; optical properties; polarization; reflectance ID YBA2CU3O7 SUPERCONDUCTING FILMS; SPECULAR REFLECTANCE; REGION AB We have investigated the reflectance of crystalline silicon and germanium samples for infrared radiation polarized parallel and perpendicular to the plane of incidence. A Fourier transform infrared (FT-IR) spectrometer was employed to measure the specular reflectance at angles of incidence from 20 degrees to 60 degrees in the wavelength range between 2 mu m and 25 mu m The measurements agree with the theoretical analysis to within the experimental uncertainty. At large angles of incidence, the reflectance depends strongly on polarization. Since the beam in a spectrometer generally exhibits partial polarization, the measured reflectance without a polarizer may differ from the average reflectance for the two polarization states. This work demonstrates that silicon and germanium can be used as standard reference materials for specular reflectance in the mid-infrared region. RP Zhang, ZM (reprint author), NIST,RADIOMETR PHYS DIV,GAITHERSBURG,MD 20899, USA. NR 26 TC 4 Z9 4 U1 0 U2 1 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD, ENGLAND OX5 1GB SN 1350-4495 J9 INFRARED PHYS TECHN JI Infrared Phys. Technol. PD JUN PY 1996 VL 37 IS 4 BP 539 EP 546 DI 10.1016/S1350-4495(95)00118-2 PG 8 WC Instruments & Instrumentation; Optics; Physics, Applied SC Instruments & Instrumentation; Optics; Physics GA UR651 UT WOS:A1996UR65100018 ER PT J AU Zerbetto, SC Zink, LR Evenson, KM Vasconcellos, ECC AF Zerbetto, SC Zink, LR Evenson, KM Vasconcellos, ECC TI New NH2H4 far-infrared laser lines and their frequencies SO INTERNATIONAL JOURNAL OF INFRARED AND MILLIMETER WAVES LA English DT Article DE N2H4 new laser lines; far-infrared; frequency measurements AB We report 25 new far-infrared laser lines and 26 heterodyne frequency measurements in hydrazine. The frequencies range from 1.0 to 5.5 THz with most of the frequencies between 2.5 and 4.0 THz. The lines were generated in a high frequency, far-infrared Fabry-Perot laser cavity pumped by a CO2 laser. The cavity has a high Q for wavelengths below 150 mu m and uses variable coupling to optimize the power for each line. C1 UNIV COLORADO,COOPERAT INST RES ENVIRONM SCI,BOULDER,CO 80309. UNICAMP,DEPT ELETRON QUANT,INST FIS GLEB WATAGHIN,BR-13083970 CAMPINAS,SP,BRAZIL. RP Zerbetto, SC (reprint author), NATL INST STAND & TECHNOL,DIV TIME & FREQUENCY,325 BROADWAY,BOULDER,CO 80303, USA. RI Inst. of Physics, Gleb Wataghin/A-9780-2017 NR 4 TC 8 Z9 8 U1 0 U2 1 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 JUN PY 1996 VL 17 IS 6 BP 1041 EP 1047 DI 10.1007/BF02101435 PG 7 WC Engineering, Electrical & Electronic; Optics; Physics, Applied SC Engineering; Optics; Physics GA UP241 UT WOS:A1996UP24100007 ER PT J AU Zerbetto, SC Zink, LR Evenson, KM Vasconcellos, ECC AF Zerbetto, SC Zink, LR Evenson, KM Vasconcellos, ECC TI Frequency measurements of 3 to 11 THZ laser lines of CH3OH SO INTERNATIONAL JOURNAL OF INFRARED AND MILLIMETER WAVES LA English DT Article DE frequency measurements; high frequency; CH3OH; far-infrared laser AB We measured the frequencies of 12 far-infrared laser lines generated in a high-frequency Fabry-Perot laser cavity containing methanol, pumped by a CO2 laser. The frequencies are in the range 2.8 to 11.4 THz (105.4 to 26.2 mu m). Ten of the measured frequencies are higher than 7 THz, and help to fill the laser frequency gaps in this region, Five of the measured lines are new. The 11.4 THz line has the highest frequency of an optically pumped laser ever measured with the CO2 laser heterodyne technique. C1 UNIV COLORADO,COOPERAT INST RES ENVIRONM SCI,BOULDER,CO 80309. UNICAMP,DEPT ELETRON QUANT,INST FIS GLEB WATAGHIN,BR-13083970 CAMPINAS,SP,BRAZIL. RP Zerbetto, SC (reprint author), NATL INST STAND & TECHNOL,DIV TIME & FREQUENCY,325 BROADWAY,BOULDER,CO 80303, USA. RI Inst. of Physics, Gleb Wataghin/A-9780-2017 NR 7 TC 6 Z9 6 U1 0 U2 2 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 JUN PY 1996 VL 17 IS 6 BP 1049 EP 1054 DI 10.1007/BF02101436 PG 6 WC Engineering, Electrical & Electronic; Optics; Physics, Applied SC Engineering; Optics; Physics GA UP241 UT WOS:A1996UP24100008 ER PT J AU Simiu, E AF Simiu, E TI Melnikov process for stochastically perturbed, slowly varying oscillators: Application to a model of wind-driven coastal currents SO JOURNAL OF APPLIED MECHANICS-TRANSACTIONS OF THE ASME LA English DT Article ID CHAOS AB The stochastic Melnikov approach is extended to a class of slowly varying dynamical systems. It is found that (1) necessary conditions for chaos induced by stochastic perturbations depend on the excitation spectrum and the transfer function in the expression for the Melnikov transform; (2) the Melnikov approach allows the estimation of lower bounds for (a) the mean time of exit from preferred regions of phase space, and (b) the probability that exits from those regions cannot occur during a specified time interval. For a system modeling wind-induced currents, the deterministic Melnikov approach would indicate that chaotic transport cannot occur for certain parameter ranges. However, the more realistic stochastic Melnikov approach shows that, for those same parameter ranges, the necessary conditions for exits during a specified time interval are satisfied with probabilities that increase as the rime interval increases. RP Simiu, E (reprint author), NATL INST STAND & TECHNOL,BLDG & FIRE RES LAB,GAITHERSBURG,MD 20899, USA. NR 19 TC 7 Z9 7 U1 0 U2 0 PU ASME-AMER SOC MECHANICAL ENG PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 SN 0021-8936 J9 J APPL MECH-T ASME JI J. Appl. Mech.-Trans. ASME PD JUN PY 1996 VL 63 IS 2 BP 429 EP 435 DI 10.1115/1.2788884 PG 7 WC Mechanics SC Mechanics GA UU357 UT WOS:A1996UU35700029 ER PT J AU Egelhoff, WF Chen, PJ Powell, CJ Stiles, MD McMichael, RD Lin, CL Sivertsen, JM Judy, JH Takano, K Berkowitz, AE AF Egelhoff, WF Chen, PJ Powell, CJ Stiles, MD McMichael, RD Lin, CL Sivertsen, JM Judy, JH Takano, K Berkowitz, AE TI The trade-off between large magnetoresistance and small coercivity in symmetric spin valves SO JOURNAL OF APPLIED PHYSICS LA English DT Article ID EXCHANGE-ANISOTROPY; NIO; MULTILAYERS; NI81FE19; FILMS; COO AB We have investigated the use of various alloys as substitutes for pure Co in the center film of symmetric spin valves of the type NiO/Co/Cu/Co/Cu/Co/NiO. The aim of this work is to identify magnetic materials that exhibit smaller coercivities than pure Co for the center or ''valve'' film but which retain much of the giant magnetoresistance associated with a pure Co film. The materials investigated include Co95Fe5, Co90Fe10, Ni80Fe20, Co86Fe10.5Ni3.5, and Co85B15. It appears that each of these alloys scatters electrons more strongly than does pure Co as they cross the center film. This scattering degrades the dual spin-valve effect, which is the primary advantage of the symmetric spin valve. As a result, a tradeoff exists between large GMR and small coercivity when using these materials. (C) 1996 American Institute of Physics. C1 UNIV MINNESOTA,CTR MICROMAGNET & INFORMAT TECHNOL,MINNEAPOLIS,MN 55455. UNIV MINNESOTA,DEPT CHEM ENGN & MAT SCI,MINNEAPOLIS,MN 55455. UNIV MINNESOTA,DEPT ELECT ENGN,MINNEAPOLIS,MN 55455. UNIV CALIF SAN DIEGO,DEPT PHYS,LA JOLLA,CA 92093. RP Egelhoff, WF (reprint author), NATL INST STAND & TECHNOL,GAITHERSBURG,MD 20899, USA. RI McMichael, Robert/J-8688-2012; Stiles, Mark/K-2426-2012; OI Stiles, Mark/0000-0001-8238-4156; McMichael, Robert/0000-0002-1372-664X NR 12 TC 13 Z9 13 U1 0 U2 0 PU AMER INST PHYSICS PI WOODBURY PA CIRCULATION FULFILLMENT DIV, 500 SUNNYSIDE BLVD, WOODBURY, NY 11797-2999 SN 0021-8979 J9 J APPL PHYS JI J. Appl. Phys. PD JUN 1 PY 1996 VL 79 IS 11 BP 8603 EP 8606 DI 10.1063/1.362457 PG 4 WC Physics, Applied SC Physics GA UN852 UT WOS:A1996UN85200072 ER PT J AU Ralph, FM Neiman, PJ Ruffieux, D AF Ralph, FM Neiman, PJ Ruffieux, D TI Precipitation identification from radar wind profiler spectral moment data: Vertical velocity histograms, velocity variance, and signal power vertical velocity correlations SO JOURNAL OF ATMOSPHERIC AND OCEANIC TECHNOLOGY LA English DT Article ID RAINDROP SIZE DISTRIBUTIONS; DOPPLER RADAR; FREQUENCY AB Correlations between range-corrected signal power S-rc and radial vertical velocity V-r from the vertical beam of a UHF wind profiler can be used to distinguish between air- and precipitation-dominated echoes using an S-rc-V-r correlation diagram. While there is no clear correlation between vertical air motions and S-rc there is a strong correlation between the precipitation fall velocity and S-rc, in snow, and to a lesser extent, in rain. This is illustrated through intercomparison of three types of precipitation events. and two types of clear-air events. Using a histogram of V-r from an event where there is evidence of precipitation in its S-rc-V-r correlation diagram, and from other information, it is possible to objectively determine a threshold value of V-r, referred to as V-r, that approximately identifies which measurements are dominated by Rayleigh scattering from precipitation in that event. A method is introduced that uses the histogram of observed V-r from that event to provide an estimate of how many measurements are incorrectly attributed to Bragg scattering or Rayleigh scattering as a function of V-T. The error estimates can be used to select V-T on a case-by-case basis and according to the needs of the particular application. An objective dual-optimization technique results in an estimated overall error of less than 6%, averaged over three case studies. In addition, it is shown that inclusion of velocity variance from the vertical beam in the S-rc-V-r correlation diagrams can help distinguish between rain and snow, and between convective and stratiform precipitation. C1 UNIV COLORADO,COOPERAT INST RES ENVIRONM SCI,BOULDER,CO 80309. RP Ralph, FM (reprint author), NOAA,ERL,ENVIRONM TECHNOL LAB,R-E-ET7,325 BROADWAY,BOULDER,CO 80303, USA. NR 28 TC 20 Z9 20 U1 0 U2 0 PU AMER METEOROLOGICAL SOC PI BOSTON PA 45 BEACON ST, BOSTON, MA 02108-3693 SN 0739-0572 J9 J ATMOS OCEAN TECH JI J. Atmos. Ocean. Technol. PD JUN PY 1996 VL 13 IS 3 BP 545 EP 559 DI 10.1175/1520-0426(1996)013<0545:PIFRWP>2.0.CO;2 PG 15 WC Engineering, Ocean; Meteorology & Atmospheric Sciences SC Engineering; Meteorology & Atmospheric Sciences GA UL668 UT WOS:A1996UL66800001 ER PT J AU Orr, BW Martner, BE AF Orr, BW Martner, BE TI Detection of weakly precipitating winter clouds by a NOAA 404-MHz wind profiler SO JOURNAL OF ATMOSPHERIC AND OCEANIC TECHNOLOGY LA English DT Article AB Recent studies have demonstrated that the 404-MHz wind profilers of the National Oceanic and Atmospheric Administration WPDN (Wind Profiler Demonstration Network) can detect precipitation under most circumstances. Their ability to detect nonprecipitating and weakly precipitating clouds, however, has remained the subject of debate. To address this question, a 35-GHz K-a-band cloud-sensing radar was operated side by side with a WPDN profiler in Colorado during the winter of 1993. The short wavelength (0.87 cm), finescale resolution, and excellent sensitivity of the K-a-band system to small hydrometeors make it very well suited for detailed measurements of clouds and weak precipitation. Comparisons of data from the two instruments show that in addition to detecting precipitation, the profiler did indeed detect nonprecipitating ice clouds under some circumstances that can be approximately delineated by profiler reflectivity and vertical velocity thresholds. These thresholds are a function of height for the case examined. A weak cloud of given intensity is easier for the profiler to detect if it is located high in the troposphere rather than close to the ground, because it contrasts more strongly against the background of clear-air reflectivity, which generally decreases sharply with height. The apparent mechanism of cloud detection by the profiler is Rayleigh backscattering from ice crystals that are larger than typical cloud droplets but have minimal fall speeds. RP Orr, BW (reprint author), NOAA,ETL,325 BROADWAY,BOULDER,CO 80303, USA. NR 20 TC 10 Z9 10 U1 0 U2 0 PU AMER METEOROLOGICAL SOC PI BOSTON PA 45 BEACON ST, BOSTON, MA 02108-3693 SN 0739-0572 J9 J ATMOS OCEAN TECH JI J. Atmos. Ocean. Technol. PD JUN PY 1996 VL 13 IS 3 BP 570 EP 580 DI 10.1175/1520-0426(1996)013<0570:DOWPWC>2.0.CO;2 PG 11 WC Engineering, Ocean; Meteorology & Atmospheric Sciences SC Engineering; Meteorology & Atmospheric Sciences GA UL668 UT WOS:A1996UL66800003 ER PT J AU Porter, DL Shih, HH AF Porter, DL Shih, HH TI Investigations of temperature effects on NOAA's next generation water level measurement system SO JOURNAL OF ATMOSPHERIC AND OCEANIC TECHNOLOGY LA English DT Article ID SEA-LEVEL AB The National Oceanic and Atmospheric Administration collects tide and water-level data by using an air acoustic tide gauge in its Next Generation Water Level Measurement System (NGWLMS). The elevation of the water is calculated from the round-trip travel time of an acoustic wave generated from a source mounted above the water. At some sites, solar radiation on the tide well can set up a nonuniform temperature structure in the well. This temperature effect can modify the travel time of the sound pulse, thereby introducing an offset into the estimate of the water level and hence into the computation of datums, such as mean sea level, which is a significant global change index. This diurnal temperature effect was quantified by computing day and night datums for tide stations located at La Jolla, California, and Baltimore, Maryland. By employing the difference in these datums, a method of delineating and removing this temperature effect was developed. This analysis resulted in 1) a quantifiable method for determining the need fur maintaining temperature sensors at NGWLMS locations, 2) an optimized temperature correction formula, and 3) an important finding that in most cases the temperature effect will have little impact on significant global change indices such as the yearly mean sea level. C1 NOAA,NATL OCEAN SERV,SILVER SPRING,MD. RP Porter, DL (reprint author), JOHNS HOPKINS UNIV,APPL PHYS LAB,JOHNS HOPKINS RD,LAUREL,MD 20723, USA. NR 27 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 JUN PY 1996 VL 13 IS 3 BP 714 EP 725 DI 10.1175/1520-0426(1996)013<0714:IOTEON>2.0.CO;2 PG 12 WC Engineering, Ocean; Meteorology & Atmospheric Sciences SC Engineering; Meteorology & Atmospheric Sciences GA UL668 UT WOS:A1996UL66800015 ER PT J AU Davis, S Anderson, DT Farrell, JT Nesbitt, DJ AF Davis, S Anderson, DT Farrell, JT Nesbitt, DJ TI Isotopic substitution of a hydrogen bond: A near infrared study of intramolecular vibrations in (DF)(2) SO JOURNAL OF CHEMICAL PHYSICS LA English DT Article ID POTENTIAL-ENERGY SURFACES; QUASI-ADIABATIC CHANNELS; HF DIMER; FLUORIDE DIMER; STRETCHING FUNDAMENTALS; MOLECULAR SPECTROSCOPY; TUNNELING DYNAMICS; HIGH-RESOLUTION; SLIT-JET; PREDISSOCIATION AB High resolution near infrared spectra of the two high frequency intramolecular modes in (DF)(2) have been characterized using a slit-jet infrared spectrometer. In total, four pairs of vibration-rotation-tunneling (VRT) bands are observed, corresponding to K=0 and K=1 excitation of both the nu(2) (''bound'') and nu(1) (''free'') intramolecular DF stretching modes. Analysis of the rotationally resolved spectra provides vibrational origins, rotational constants, tunneling splittings and upper state predissociation lifetimes for all four states. The rotational constants indicate that the deuterated hydrogen bond contracts and bends upon intramolecular excitation, analogous to what has been observed for (HF)(2). The isotope and K dependence of tunneling splittings for (HF)(2) and (DF)(2) in both intramolecular modes is interpreted in terms of a semiclassical 1-D tunneling model. High resolution line shape measurements reveal vibrational predissociation broadening in (DF)(2): 56(2) and 3(2) MHz for the nu(2) (bound) and nu(1) (free) intramolecular stretching modes, respectively. This 20-fold mode specific enhancement parallels the greater than or equal to 30-fold enhancement observed between analogous intramolecular modes of (HF)(2), further elucidating the role of nonstatistical predissociation dynamics in such hydrogen bonded clusters. (C) 1996 American Institute of Physics. C1 UNIV COLORADO, NATL INST STAND & TECHNOL, BOULDER, CO 80309 USA. UNIV COLORADO, DEPT CHEM & BIOCHEM, BOULDER, CO 80309 USA. RP Davis, S (reprint author), UNIV COLORADO, JOINT INST LAB ASTROPHYS, BOULDER, CO 80309 USA. NR 69 TC 23 Z9 23 U1 0 U2 5 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 JUN 1 PY 1996 VL 104 IS 21 BP 8197 EP 8209 DI 10.1063/1.471604 PG 13 WC Chemistry, Physical; Physics, Atomic, Molecular & Chemical SC Chemistry; Physics GA UM909 UT WOS:A1996UM90900002 ER PT J AU Goldenberg, SB Shapiro, LJ AF Goldenberg, SB Shapiro, LJ TI Physical mechanisms for the association of El Nino and west African rainfall with Atlantic major hurricane activity SO JOURNAL OF CLIMATE LA English DT Article ID SAHELIAN MONSOON RAINFALL; SOUTHERN OSCILLATION; TROPICAL STORM; INTENSE; VARIABILITY; CIRCULATION; FREQUENCY; PACIFIC; SEASON AB Physical mechanisms responsible for the contemporaneous association, shown in earlier studies, of North Atlantic basin major hurricane (MH) activity with western Sahelian monsoon rainfall and an equatorial eastern Pacific sea surface temperature index of El Nino are examined, using correlations with 200- and 700-mb level wind data for the period 1968-92. The use of partial correlations isolates some of the relationships associated with the various parameters. The results support previous suggestions that the upper- and lower-level winds over the region in the basin between similar to 10 degrees and 20 degrees N where most MHs begin developing are critical determinants of the MH activity in each hurricane season. In particular, interannual fluctuations in the winds that produce changes in the magnitude of vertical shear are one of the most important factors, with reduced shear being associated with increased activity and stronger shear with decreased activity. The results show that most of these critical wind fluctuations are explained by their relationship to the SST and rainfall fluctuations. Results confirm previous findings that positive (warm) eastern Pacific SST and negative (drought) Sahelian rainfall anomalies are associated with suppressed Atlantic basin tropical cyclone activity through an equatorially confined near-zonal circulation with upper-level westerlies and lower-level easterlies that act to increase the climatological westerly vertical shear in the main development region. SST and rainfall anomalies of the opposite sense are related to MH activity through a zonal circulation with upper-level easterly and lower-level westerly wind anomalies that act to cancel out some of the climatological westerly vertical shear. The results also show that changes in vertical shear to the north of the main development region are unrelated to, or possibly even out of phase with, changes in the development region, providing a possible physical explanation for the observations from recent studies of the out-of-phase relationship of interannual fluctuations in MH activity in the region poleward of similar to 25 degrees N with fluctuations in activity to the south. The interannual variability of MH activity explained by Sahel rainfall is almost three times that explained by the eastern Pacific SSTs. It is demonstrated that a likely reason for this result is that the SST-associated vertical shears are more equatorially confined, so that the changes in shear in the main development region have a stronger association with the rainfall than with the SSTs. C1 AOML,HURRICANE RES DIV,MIAMI,FL. RI Goldenberg, Stanley/C-5965-2014 OI Goldenberg, Stanley/0000-0001-6730-5819 NR 46 TC 251 Z9 256 U1 1 U2 17 PU AMER METEOROLOGICAL SOC PI BOSTON PA 45 BEACON ST, BOSTON, MA 02108-3693 SN 0894-8755 J9 J CLIMATE JI J. Clim. PD JUN PY 1996 VL 9 IS 6 BP 1169 EP 1187 DI 10.1175/1520-0442(1996)009<1169:PMFTAO>2.0.CO;2 PG 19 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA UY340 UT WOS:A1996UY34000001 ER PT J AU Kushnir, Y Held, IM AF Kushnir, Y Held, IM TI Equilibrium atmospheric response to North Atlantic SST anomalies SO JOURNAL OF CLIMATE LA English DT Article ID SEA-SURFACE TEMPERATURE; GENERAL-CIRCULATION MODEL; HEAT-FLUX ANOMALIES; INTERDECADAL VARIATIONS; OCEAN; PACIFIC; GCM; VARIABILITY; DEPENDENCE; SIMULATION AB The equilibrium general circulation model (GCM) response to sea surface temperature (SST) anomalies in tile western North Atlantic region is studied. A coarse resolution GCM, with realistic lower boundary conditions including topography and climatological SST distribution, is integrated in perpetual January and perpetual October modes, distinguished from one another by the strength of the midlatitude westerlies. An SST anomaly with a maximum of 4 degrees C is added to the climatological SST distribution of the model with both positive and negative polarity, These anomaly runs are compared to one another, and to a control integration, to determine the atmospheric response. In al cases warming (cooling) of the midlatitude ocean surface yields a warming (cooling) of the atmosphere over and to the east of the SST anomaly center. The atmospheric temperature change is largest near tile surface and decreases upward. Consistent with this simple thermal response, the geopotential height field displays a baroclinic response with a shallow anomalous low somewhat downstream from the warm SST anomaly. The equivalent barotropic, downstream response is weak and not robust: To help interpret the results, the realistic GCM integrations are compared with parallel idealized model runs. The idealized model has full physics and a similar horizontal and vertical resolution, bur an all-ocean surface with a single, permanent zonal asymmetry. The idealized and realistic versions of the GCM display compatible response patterns that are qualitatively consistent with stationary. linear, quasigeostrophic theory. However, the idealized model response is stronger and more coherent. The differences between the two model response patterns can be reconciled based on the size of the anomaly, the model treatment of cloud-radiation interaction,and the static stability of the model atmosphere in the vicinity of the ST anomaly. Modal results are contrasted with other GCM studies and observations. C1 NOAA,GEOPHYS FLUID DYNAM LAB,PRINCETON,NJ. RP Kushnir, Y (reprint author), COLUMBIA UNIV,LAMONT DOHERTY EARTH OBSERV,POB 1000,PALISADES,NY 10964, USA. RI Kushnir, Yochanan/B-4472-2013 NR 43 TC 130 Z9 132 U1 0 U2 8 PU AMER METEOROLOGICAL SOC PI BOSTON PA 45 BEACON ST, BOSTON, MA 02108-3693 SN 0894-8755 J9 J CLIMATE JI J. Clim. PD JUN PY 1996 VL 9 IS 6 BP 1208 EP 1220 DI 10.1175/1520-0442(1996)009<1208:EARTNA>2.0.CO;2 PG 13 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA UY340 UT WOS:A1996UY34000003 ER PT J AU Soden, BJ Lanzante, JR AF Soden, BJ Lanzante, JR TI An assessment of satellite and radiosonde climatologies of upper-tropospheric water vapor SO JOURNAL OF CLIMATE LA English DT Article ID RELATIVE-HUMIDITY; RADIANCES; CLEAR AB This study compares radiosonde and satellite climatologies of upper-tropospheric water vapor for the period 1979-1991. Comparison of the two climatologies reveals significant differences in the regional distribution of upper-tropospheric relative humidity. These discrepancies exhibit a distinct geopolitical dependence that is demonstrated to result from international differences in radiosonde instrumentation. Specifically, radiosondes equipped with goldbeater's skin humidity sensors (found primarily in the former Soviet Union, China, and eastern Europe) report a systematically moister upper troposphere relative to the satellite observations, whereas radiosondes equipped with capacitive or carbon hygristor sensors (found at most other locations) report a systematically drier upper troposphere. The bias between humidity sensors is roughly 15%-20% in terms of the relative humidity, bring slightly greater during summer than during winter and greater in the upper troposphere than in the midtroposphere. However, once the instrumentation bias is accounted for, regional variations of satellite and radiosonde upper-tropospheric relative humidity are shown to be in good agreement. Additionally, temporal variations in radiosonde upper-tropospheric humidity agree reasonably well with the satellite observations and exhibit much less dependence upon instrumentation. The impact that the limited spatial coverage of the radiosonde network has upon the moisture climatology is also examined and found to introduce systematic errors of 10%-20% relative humidity over data-sparse regions of the Tropics. It is further suggested that the present radiosonde network lacks sufficient coverage in the eastern tropical Pacific to adequately capture ENSO-related variations in upper-tropospheric moisture. Finally, we investigate the impact of the clear-sky sampling restriction upon the satellite moisture climatology. Comparison of clear-sky and total-sky radiosonde observations suggests the clear-sky sampling limitation introduces a modest dry bias (<10% relative humidity) in the satellite climatology. RP Soden, BJ (reprint author), NOAA,GEOPHYS FLUID DYNAM LAB,POB 308,PRINCETON,NJ 08542, USA. NR 28 TC 133 Z9 135 U1 0 U2 6 PU AMER METEOROLOGICAL SOC PI BOSTON PA 45 BEACON ST, BOSTON, MA 02108-3693 SN 0894-8755 J9 J CLIMATE JI J. Clim. PD JUN PY 1996 VL 9 IS 6 BP 1235 EP 1250 DI 10.1175/1520-0442(1996)009<1235:AAOSAR>2.0.CO;2 PG 16 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA UY340 UT WOS:A1996UY34000005 ER PT J AU Huang, J vandenDool, HM Georgakakos, KP AF Huang, J vandenDool, HM Georgakakos, KP TI Analysis of model-calculated soil moisture over the United States (1931-1993) and applications to long-range temperature forecasts SO JOURNAL OF CLIMATE LA English DT Article ID AIR-TEMPERATURE; PRECIPITATION; VARIABILITY AB A long time series of monthly soil moisture data during the period of 1931-1993 over the entire U.S. continent has been created with a one-layer soil moisture model. The model is based on the water budget in the soil and uses monthly temperature and monthly precipitation as input. The data are for 344 U.S. climate divisions during the period of 1931-1933. The main goals of this paper are 1) to improve our understanding of soil moisture aad its effects on the atmosphere and 2) to apply the calculated soil moisture toward long-range temperature forecasts. In this study, the model parameters are estimated using observed precipitation, temperature, and runoff in Oklahloma (1960-1989) and applied to the entire United Slates. The comparison with the 8-yr (1984-1991) observed soil moisture in Illinois indicates that the model gives a reasonable simulation of soil moisture with both climatology and interannual variability. The analyses of the calculated soil moisture show that the climatological soil moisture is high in the east and low in the west (except the West Coast), which is determined by the climatological precipitation amounts. The annual cycle of soil moisture, however, is determined largely by evaporation. Anomalies in soil moisture are driven by precipitation anomalies, but their timescales are to first order determined by both climatological temperature (through evaporation) and climatological precipitation. The soil moisture anomaly persistence is higher where normal temperature and precipitation are low, which is the case in the west in summer. The spatial scale of soil moisture anomalies has been analyzed and found to be larger than that of precipitation but smaller than that of temperature. Authors found that generally in the U.S. evaporation anomalies are much smaller in magnitude than precipitation anomalies. Furthermore, observed and calculated soil moisture anomalies have a broad frequency distribution but not the strongly bimodal distribution indicative of water recycling. Compared to antecedent precipitation, soil moisture is a better predictor for future monthly temperature. Soil moisture can provide extra skill in predicting temperature in large areas of interior continent in summer, particularly al longer leads. The predictive skill Isi soil moisture is even higher when the predictand is daily maximum temperature instead of daily mean temperature. C1 NATL CTR ENVIRONM PREDICT,CLIMATE PREDICT CTR,WASHINGTON,DC. HYDROL RES CTR,SAN DIEGO,CA. UNIV CALIF SAN DIEGO,SCRIPPS INST OCEANOG,SAN DIEGO,CA 92103. NR 31 TC 246 Z9 257 U1 3 U2 38 PU AMER METEOROLOGICAL SOC PI BOSTON PA 45 BEACON ST, BOSTON, MA 02108-3693 SN 0894-8755 J9 J CLIMATE JI J. Clim. PD JUN PY 1996 VL 9 IS 6 BP 1350 EP 1362 DI 10.1175/1520-0442(1996)009<1350:AOMCSM>2.0.CO;2 PG 13 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA UY340 UT WOS:A1996UY34000013 ER PT J AU Chen, CT Ramaswamy, V AF Chen, CT Ramaswamy, V TI Sensitivity of simulated global climate to perturbations in low-cloud microphysical properties .1. Globally uniform perturbations SO JOURNAL OF CLIMATE LA English DT Article ID GENERAL-CIRCULATION MODEL; SOLAR-RADIATION MEASUREMENTS; EFFECTIVE PARTICLE RADIUS; OPTICAL-THICKNESS; LIQUID WATER; FEEDBACK PROCESSES; CO2 CONCENTRATION; PARAMETERIZATION; ATMOSPHERE; ALBEDO AB The sensitivity of the global climate to perturbations in the microphysical properties of low clouds is investigated using a general circulation model coupled to a static mixed layer ocean with fixed cloud distributions and incorporating a new broadband parameterization for cloud radiative properties. A series of GCM experiments involving globally uniform perturbations in cloud liquid water path or effective radius (albedo perturbations), along with one for a doubling of carbon dioxide (greenhouse perturbation), lead to the following results: 1) The model's climate sensitivity (ratio of global-mean surface temperature response to the global-mean radiative forcing) is virtually independent (to similar to 10%) of the sign, magnitude, and the spatial pattern of the forcings considered, thus revealing a linear and invariant nature of the model's global-mean response. 2) Although the total climate feedback is very similar in all the experiments, the strengths of the individual feedback mechanisms (e.g., water vapor, albedo) are different for positive and negative forcings. 3) Changes in moisture, tropospheric static stability, and sea ice extent govern the vertical and zonal patterns of the temperature response, with the spatial distribution of the response being quite different from that of the radiative forcing. 4) The zonal surface temperature response pattern, normalized with respect to the global mean, is different for experiments with positive and negative forcings, particularly in the polar regions of both hemispheres, due to differing changes in sea ice. 5) The change in the surface radiative fluxes is different for the carbon dioxide doubling and cloud liquid water path decrease experiments, even though both cases have the same radiative forcing and a similar global-mean surface temperature response; this leads to differences in the vigor of the hydrologic cycle (evaporation and precipitation rates) in these two experiments. C1 PRINCETON UNIV,NOAA,GEOPHYS FLUID DYNAM LAB,ATMOSPHER & OCEAN SCI PROGRAM,PRINCETON,NJ 08542. NR 47 TC 15 Z9 15 U1 0 U2 0 PU AMER METEOROLOGICAL SOC PI BOSTON PA 45 BEACON ST, BOSTON, MA 02108-3693 SN 0894-8755 J9 J CLIMATE JI J. Clim. PD JUN PY 1996 VL 9 IS 6 BP 1385 EP 1402 DI 10.1175/1520-0442(1996)009<1385:SOSGCT>2.0.CO;2 PG 18 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA UY340 UT WOS:A1996UY34000016 ER PT J AU Smith, TM Reynolds, RW Livezey, RE Stokes, DC AF Smith, TM Reynolds, RW Livezey, RE Stokes, DC TI Reconstruction of historical sea surface temperatures using empirical orthogonal functions SO JOURNAL OF CLIMATE LA English DT Article ID PACIFIC; OCEAN AB Studies of climate variability often rely on high quality sea surface temperature (SST) anomalies. Although the high-resolution National Centers for Environmental Prediction (formerly the National Meteorological Center) optimum interpolation (OI) SST analysis is satisfactory for these studies, the OI resolution cannot be maintained before November 1981 due to the lack of satellite data. Longer periods of SSTs have come from traditional analyses of in situ (ship and buoy) SST observations alone. A new interpolation method is developed using spatial patterns from empirical orthogonal functions (EOFs)-that is, a principal component analysis-to improve analyses of SST anomalies from 1950 to 1981. The method uses the more accurate OI analyses from 1982 to 1993 to produce the spatial EOFs. The dominant EOF modes (which correspond to the largest variance) are used as basis functions and are fit, in a least squares sense, to the in situ data to determine the time dependence of each mode. A complete field of SST anomalies is then reconstructed from these spatial and temporal modes. The use of EOF basis functions produces an improved in situ SST analysis that more realistically represents sparsely sampled, large scale structures than traditional analyses. The EOF reconstruction method is developed for the tropical Pacific for the period 1982-92 and compared to the OI. The method is then expanded to the globe and applied to a much longer period, 1950-92. The results show that the reconstructed fields generally have lower rms differences than the traditional in-situ-only analyses relative to the OI. In addition, the reconstructed fields were found to be smoother than the traditional analyses but with enhanced large-scale signals (e.g., ENSO). Regions where traditional analyses are adequate include some parts of the North Atlantic and the North Pacific, where in situ sampling is most dense. Although the shape of SST anomaly patterns can differ greatly between the reconstruction and traditional in situ analysis, area-averaged results from both analyses show similar anomalies. RP Smith, TM (reprint author), NOAA,NWS,NATL CTR ENVIRONM PREDICT,5200 AUTH RD,CAMP SPRINGS,MD 20746, USA. RI Smith, Thomas M./F-5626-2010 OI Smith, Thomas M./0000-0001-7469-7849 NR 25 TC 482 Z9 500 U1 1 U2 26 PU AMER METEOROLOGICAL SOC PI BOSTON PA 45 BEACON ST, BOSTON, MA 02108-3693 SN 0894-8755 J9 J CLIMATE JI J. Clim. PD JUN PY 1996 VL 9 IS 6 BP 1403 EP 1420 DI 10.1175/1520-0442(1996)009<1403:ROHSST>2.0.CO;2 PG 18 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA UY340 UT WOS:A1996UY34000017 ER PT J AU Easterling, DR Peterson, TC Karl, TR AF Easterling, DR Peterson, TC Karl, TR TI On the development and use of homogenized climate datasets SO JOURNAL OF CLIMATE LA English DT Article ID UNITED-STATES; PRECIPITATION; MAXIMUM; SERIES AB At the National Climatic Data Center, two basic approaches to making homogeneity adjustments to climate data have been developed. The first is based on the use of metadata (station history files) and is used in the adjustments made to the U.S. Historical Climatology Network monthly dataset. The second approach is non-metadata based and was developed for use with the Global Historical Climatology Network dataset, since there are not extensive station history files for most stations in the dataset. In this paper the two methodologies are reviewed and the adjustments made using each are compared, then the results are discussed. Last, some brief guidelines on the limitations and uses of these data are provided. RP Easterling, DR (reprint author), NOAA,NESDIS,NATL CLIMAT DATA CTR,FED BLDG,ASHEVILLE,NC 28801, USA. NR 21 TC 87 Z9 99 U1 0 U2 6 PU AMER METEOROLOGICAL SOC PI BOSTON PA 45 BEACON ST, BOSTON, MA 02108-3693 SN 0894-8755 J9 J CLIMATE JI J. Clim. PD JUN PY 1996 VL 9 IS 6 BP 1429 EP 1434 DI 10.1175/1520-0442(1996)009<1429:OTDAUO>2.0.CO;2 PG 6 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA UY340 UT WOS:A1996UY34000019 ER PT J AU Misra, DN AF Misra, DN TI Interaction of citric acid with hydroxyapatite: Surface exchange of ions and precipitation of calcium citrate SO JOURNAL OF DENTAL RESEARCH LA English DT Article DE formation of calcium citrate; hydroxyapatite; interaction with citric acid; periodontal regeneration; restorative bonding; surface exchange ID INTERFACIAL PROPERTIES; DENTIN; DEMINERALIZATION; ENAMEL AB The use of citric acid is efficacious and distinctive in the demineralization of dentinal root surfaces for periodontal regeneration and in the etching and conditioning of enamel or dentin for bonding restorative resins. To decipher the role of citric acid in these applications, it is important that one have a basic understanding of its interaction with synthetic hydroxyapatite. The uptake or removal of citrate ions from aqueous solutions of citric acid (4 to 100 mmol/L, 10 mL) by hydroxyapatite (1 g) was studied at 22 degrees C after a given reaction period (from 3 hr to 11 days) by immediate spectrophotometric monitoring of the concentrations of the filtrates (214 nm). The concentrations of calcium, phosphate, and hydrogen ions were also determined in the same solutions. The interaction: (i) is a time-independent ionic-exchange process with the substrate when the initial acid concentrations are dilute (4 to 12.5 mmol/L), and (ii) is a reactive process that is time-dependent for higher acid concentrations. The exchange process shows an adsorption of about one citrate ion per (100) face of the unit cell of hydroxyapatite for a maximally exchanged surface. The curves representing the reactive process may be quantitatively or qualitatively explained on the basis of the supersaturation of the solutions with respect to calcium citrate and its slow precipitation. The physico-chemical analysis of the needle-shaped birefringent crystals of the precipitate from the supersaturated solutions confirms the precipitate to be Ca-3(citrate)(2) . 4H(2)O. RP Misra, DN (reprint author), NIST,AMER DENT ASSOC HLTH FDN,PAFFENBERGER RES CTR,GAITHERSBURG,MD 20899, USA. NR 27 TC 53 Z9 56 U1 2 U2 18 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 JUN PY 1996 VL 75 IS 6 BP 1418 EP 1425 PG 8 WC Dentistry, Oral Surgery & Medicine SC Dentistry, Oral Surgery & Medicine GA VK230 UT WOS:A1996VK23000014 PM 8831638 ER PT J AU Helser, TE AF Helser, TE TI Growth of silver hake within the US continental shelf ecosystem of the northwest Atlantic Ocean SO JOURNAL OF FISH BIOLOGY LA English DT Article DE von Bertalanffy parameters; randomisation tests; Monte Carlo simulation; power of test; growth curve comparison; Merluccius bilinearis ID PARAMETERS; EQUATION; TESTS AB Von Bertalanffy growth parameters were estimated for silver bake Merluccius bilinearis within four regions of the United States continental shelf ecosystem of the northwest Atlantic Ocean during 1975-1980, 1982-1987 and 1988-1992. Differences in silver hake growth were found between the Middle Atlantic and southern Georges Bank regions (P<0.01) over all three time periods. Growth also differed between northern Georges Bank and the Gulf of Maine (P<0.01) during 1975-1980 and 1982-1987, and significant differences between southern Georges Bank and northern Georges Bank were found only during 1982-1987. Silver hake in the Gulf of Maine exhibited larger asymptotic sizes, but attained their asymptotic size at slower rates (L(infinity)=47 cm and K=0.33) in comparison to silver bake in the Middle Atlantic (L(infinity)=43 cm and K=0.51), while growth parameter estimates for silver bake on Georges Bank were intermediate between these. Although significant differences in growth of silver hake between the various regions are consistent with separate stocks in the U.S. continental shelf ecosystem, the growth characteristics from the different regions are inconsistent with the presently assigned stock boundaries. (C) 1996 The Fisheries Society of the British Isles C1 NATL MARINE FISHERIES SERV,NE FISHERIES SCI CTR,WOODS HOLE,MA 02543. NR 44 TC 14 Z9 15 U1 0 U2 1 PU ACADEMIC PRESS LTD PI LONDON PA 24-28 OVAL RD, LONDON, ENGLAND NW1 7DX SN 0022-1112 J9 J FISH BIOL JI J. Fish Biol. PD JUN PY 1996 VL 48 IS 6 BP 1059 EP 1073 DI 10.1111/j.1095-8649.1996.tb01804.x PG 15 WC Fisheries; Marine & Freshwater Biology SC Fisheries; Marine & Freshwater Biology GA UV396 UT WOS:A1996UV39600003 ER PT J AU Wing, S Newell, PT Onsager, TG AF Wing, S Newell, PT Onsager, TG TI Modeling the entry of magnetosheath electrons into the dayside ionosphere SO JOURNAL OF GEOPHYSICAL RESEARCH-SPACE PHYSICS LA English DT Article ID SOLAR-WIND ELECTRONS; POLAR RAIN; PLASMA MANTLE; CUSP; MAGNETOSPHERE; MAGNETOPAUSE; RECONNECTION; ALTITUDES AB It has recently been shown that it is possible to quantitatively model the entry of magnetosheath ions and their access to the dayside ionosphere with surprisingly good results. In the same model, electrons had access to the region poleward of the cusp at unrealistically high intensities. We improve the previous model by imposing the constraints of charge quasineutrality and introducing more realistic electron magnetosheath populations. It turns out that no potential drop within the cusp proper is either needed or observed in order to enforce charge neutrality, since ions, as well as electrons, can enter freely, and they originally have the same density in the magnetosheath. Poleward of the magnetic cusp, ion entry is sharply curtailed because of the tailward magnetosheath flow, and the potential required and observed rises rapidly. This potential eliminates access of the ''core'' population of the magnetosheath electrons to the ionosphere. The typical polar rain signature observed at low altitudes fits best with the suprathermal solar wind electron population (either halo or both halo and strahl components). The model clearly shows that ions previously identified at low altitude as ''mantle'' do indeed cross the magnetopause tailward of the magnetic cusp, that is, the ionospheric mantle signature consists of ions originating in the high-altitude mantle. A single ion spectrum within the low-altitude cusp proves to consist of magnetosheath ions which have crossed the frontside magnetopause from a range of positions which commences with the merging site and extends to the magnetic cusp, but which is typically only 1-3 R(E) wide along the direction of the field line convection. C1 NOAA,SPACE ENVIRONM CTR,BOULDER,CO 80303. RP Wing, S (reprint author), JOHNS HOPKINS UNIV,APPL PHYS LAB,JOHNS HOPKINS RD,LAUREL,MD 20723, USA. NR 28 TC 37 Z9 38 U1 0 U2 1 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 SN 0148-0227 J9 J GEOPHYS RES JI J. Geophys. Res-Space Phys. PD JUN 1 PY 1996 VL 101 IS A6 BP 13155 EP 13167 DI 10.1029/96JA00395 PG 13 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA UP353 UT WOS:A1996UP35300012 ER PT J AU Chi, PJ Russell, CT Le, G Hughes, WJ Singer, HJ AF Chi, PJ Russell, CT Le, G Hughes, WJ Singer, HJ TI A synoptic study of Pc 3, 4 waves using the Air Force Geophysics Laboratory magnetometer array SO JOURNAL OF GEOPHYSICAL RESEARCH-SPACE PHYSICS LA English DT Article ID GEOMAGNETIC PULSATION SIGNALS; SOLAR-WIND VELOCITY; MAGNETIC PULSATIONS; IMF ORIENTATION; MAGNETOSPHERE; IONOSPHERE; DEPENDENCE AB We have studied the Pc 3, 4 wave amplitude recorded at the Air Force Geophysics Laboratory (AFGL) magnetometer network on August 19-20, 1978. During this period of time the wave amplitude was modulated coherently across the magnetometer network. From observations, three important factors affecting the wave amplitude measured on the ground have been determined as follows: (1) the intrinsic or magnetospheric magnitude of the wave events, (2) their local time dependence, and (3) the subsurface conductivity. We present a statistical method to calculate these three factors from the simultaneous observations of a longitudinal array of magnetometers. The intrinsic wave amplitude is found to be bursty. On short timescales the wave amplitudes do not follow our expectations based on long-term statistical studies. Amplitudes vary rapidly without concomitant changes in the solar wind. We also find that the amplification of the wave amplitude due to the subsurface conductivity is different from station to station. For the northern five AFGL stations it is found that the ratio between the largest amplification and the smallest amplification is close to 2. The local time dependence maximizes approximately at local noon. A possible reason due to the reflection of Alfven waves in the ionosphere is discussed. C1 BOSTON UNIV,CTR SPACE PHYS,BOSTON,MA 02215. NOAA,SPACE ENVIRONM LAB,BOULDER,CO 80303. RP Chi, PJ (reprint author), UNIV CALIF LOS ANGELES,INST GEOPHYS & PLANETARY PHYS,405 HILGARD AVE,LOS ANGELES,CA 90024, USA. RI Le, Guan/C-9524-2012 OI Le, Guan/0000-0002-9504-5214 NR 30 TC 12 Z9 12 U1 0 U2 1 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 SN 0148-0227 J9 J GEOPHYS RES JI J. Geophys. Res-Space Phys. PD JUN 1 PY 1996 VL 101 IS A6 BP 13215 EP 13224 DI 10.1029/96JA00139 PG 10 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA UP353 UT WOS:A1996UP35300016 ER PT J AU McAllister, AH Dryer, M McIntosh, P Singer, H Weiss, L AF McAllister, AH Dryer, M McIntosh, P Singer, H Weiss, L TI A large polar crown coronal mass ejection and a ''problem'' geomagnetic storm: April 14-23, 1994 SO JOURNAL OF GEOPHYSICAL RESEARCH-SPACE PHYSICS LA English DT Article ID DISAPPEARING SOLAR FILAMENTS; MAGNETIC STORMS; INTERPLANETARY SHOCKS; EVENTS; WIND; DEPENDENCE; PROMINENCE; STREAMER; FLARES; EARTH AB In the 1960s and 1970s, systematic programs to associate geomagnetic storms with solar flares gave rise to a category of ''problem storms'' for which there were no clear associations or for which the associations were with solar activity that seemed too insignificant to properly account for the magnitude of the geomagnetic events. In the last 2 decades the role of filament eruptions and coronal mass ejections (CMEs) in driving geomagnetic activity has received increasing attention, and an answer to the problem storm question has been pieced together. Until recently the inability to view CMEs on the solar disk has impeded a precise demonstration of the inferred relationships. The data from the Yohkoh Soft X ray Telescope (SXT), however, allow the association of soft X ray coronal structures with the aftermath of CMEs. Since CMEs are now believed to be the main cause of aperiodic severe disturbances of Earth's magnetosphere, the ability to distinguish the aftermath of a CME on the disk improves our ability to predict geomagnetic storms. On April 14, 1994, a large scale coronal arcade formation was observed by SXT after the eruption of a long section of the southern polar crown neutral line. Data from the Mauna Loa coronagraph are consistent with this event being the result of a CME that formed in the helmet streamer underlying the heliospheric current sheet. The CME was followed by a severe geomagnetic storm, starting 68 hr later, and was also observed at 3.2 AU and high heliographic latitude by the Ulysses satellite. Since there was no significant flare associated with the eruption, and no significant filament disappearance, the subsequent geomagnetic events are an extreme example of a problem storm and of the great utility of soft X ray imagers for the prediction of space weather. In this paper we have assembled a wide range of data relating to the solar event, the evolution of the region that generated it, and the various observed consequences at Earth and in the interplanetary medium. The global magnetic field changes leading to the CME are outlined, a brief description of the coronal arcade formation is given, and the arcade's association with subsequent events at Earth and the interplanetary disturbance observed at Ulysses is described. We present this case as an example of the advantages to be derived from a comprehensive multidisciplinary approach to studying these potentially disruptive phenomena. C1 SPACE ENVIRONM CTR, BOULDER, CO 80303 USA. LOS ALAMOS NATL LAB, LOS ALAMOS, NM 87545 USA. UNIV COLORADO, COOPERAT INST RES ENVIRONM SCI, BOULDER, CO 80309 USA. NR 82 TC 75 Z9 76 U1 0 U2 1 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 0148-0227 J9 J GEOPHYS RES-SPACE JI J. Geophys. Res-Space Phys. PD JUN 1 PY 1996 VL 101 IS A6 BP 13497 EP 13515 DI 10.1029/96JA00510 PG 19 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA UP353 UT WOS:A1996UP35300043 ER PT J AU Wei, LH Pajares, A Lawn, BR AF Wei, LH Pajares, A Lawn, BR TI Effect of mechanical damage on thermal conduction of plasma-sprayed coatings SO JOURNAL OF MATERIALS RESEARCH LA English DT Article AB A thermal wave methodology for monitoring the thermal conduction of ceramic coatings with accumulating mechanical damage is described. Tests are conducted on a model alumina coating containing laminar defect intralayers, Controlled subsurface damage introduced with a spherical indenter is observed using a presectioned specimen. Microcrack damage accumulates progressively with increasing contact load and number of cycles, Associated changes in thermal diffusivity, specifically in the through-thickness direction, are imaged and quantified point-by-point using laser-generated thermal waves. The effective thermal resistance of the coating increases with crack density, up to the point of failure. RP NIST, MAT SCI & ENGN LAB, GAITHERSBURG, MD 20899 USA. RI Pajares, Antonia/I-3881-2015 OI Pajares, Antonia/0000-0002-1086-7586 NR 11 TC 9 Z9 9 U1 0 U2 1 PU CAMBRIDGE UNIV PRESS PI NEW YORK PA 32 AVENUE OF THE AMERICAS, NEW YORK, NY 10013-2473 USA SN 0884-2914 EI 2044-5326 J9 J MATER RES JI J. Mater. Res. PD JUN PY 1996 VL 11 IS 6 BP 1329 EP 1332 DI 10.1557/JMR.1996.0168 PG 4 WC Materials Science, Multidisciplinary SC Materials Science GA UQ664 UT WOS:A1996UQ66400003 ER PT J AU Tsu, IF Babcock, SE Kaiser, DL AF Tsu, IF Babcock, SE Kaiser, DL TI Faceting, dislocation network structure, and various scales of heterogeneity in a YBa2Cu3O7-gamma low-angle [001] tilt boundary SO JOURNAL OF MATERIALS RESEARCH LA English DT Article ID GRAIN-BOUNDARIES; THIN-FILMS; WEAK-LINK; MICROSTRUCTURE; BICRYSTALS; TRANSPORT; JUNCTIONS; BEHAVIOR; GROWTH AB The grain boundary topography and grain boundary dislocation network structure of a 6 degrees [001] bicrystal of YBa2Cu3O7-delta were studied using diffraction-contrast transmission electron microscopy (TEM). Saw-tooth-shaped arrays of facets composed of facets with lengths of a few tens of nanometers were observed in each of two widely separated sections of the boundary. The facet planes were {110}, {310}, and {22(1) over bar}. Further subfaceting of the (130) facets into a smaller-scale (a few nanometers) saw-tooth configuration of (010) and (110) facets produced a hierarchy of facets in at least one boundary section. The dislocation content observed in each type of facet agreed well with Frank's formula. However, the dislocations within individual facets frequently were inhomogeneously distributed, contrasting the picture of evenly spaced dislocations that is derived for boundaries of infinite extent, Certain types of dislocations repeatedly were grouped near the facet centers and ends. Well-separated partial dislocations frequently were observed near the facet midsections, but not near the facet junctions. Extended (similar to 30 nm) strain contrast was observed at all of the facet junctions formed by facets with dimensions on the order of tens of nanometers. This long-range strain may be due to the finite extent of the individual facets. These results all suggest that structural inhomogeneities occur on various length scales ranging from macroscopic to just a few nanometers. Such structural heterogeneity is consistent with the electrical heterogeneity that is indicated for many YBa2Cu3O7-delta grain boundaries. C1 NIST, DIV CERAM, GAITHERSBURG, MD 20899 USA. RP UNIV WISCONSIN, MAT SCI & ENGN & APPL SUPERCONDUCT CTR, MADISON, WI 53706 USA. NR 56 TC 36 Z9 36 U1 1 U2 4 PU CAMBRIDGE UNIV PRESS PI NEW YORK PA 32 AVENUE OF THE AMERICAS, NEW YORK, NY 10013-2473 USA SN 0884-2914 EI 2044-5326 J9 J MATER RES JI J. Mater. Res. PD JUN PY 1996 VL 11 IS 6 BP 1383 EP 1397 DI 10.1557/JMR.1996.0174 PG 15 WC Materials Science, Multidisciplinary SC Materials Science GA UQ664 UT WOS:A1996UQ66400009 ER PT J AU McMillin, BK Biswas, P Zachariah, MR AF McMillin, BK Biswas, P Zachariah, MR TI In situ characterization of vapor phase growth of iron oxide-silica nanocomposites .1. 2-D planar laser-induced fluorescence and Mie imaging SO JOURNAL OF MATERIALS RESEARCH LA English DT Article ID PARTICLE SYNTHESIS; LIGHT-SCATTERING; FLAME REACTOR; AEROSOL; POWDERS; SPECTROSCOPY; FABRICATION; DISSYMMETRY; SIZE AB Planar laser-based imaging measurements of fluorescence and particle scattering have been obtained during flame synthesis of iron-oxide/silica superparamagnetic nanocomposites. The theory and application of laser-induced fluorescence, the spectroscopy of FeO(g), and the experimental approach for measurement of gas phase precursors to particle formation are discussed, The results show that the vapor phase FeO concentration rabidly rises at the primary reaction front of the flame and is very sensitive to the amount of precursor added, suggesting nucleation-controlled particle growth. The FeO vapor concentration in the main nucleation zone was found to be insensitive to the amount of silicon precursor injected, indicating th:ir nucleation occurred independently for the iron and silicon components, Light scattering measurements: indicate that nanocomposite particles sinter faster than single component silica, in agreement with TEM measurements. C1 NIST,CHEM SCI & TECHNOL LAB,GAITHERSBURG,MD 20899. UNIV CINCINNATI,DEPT ENVIRONM ENGN,AEROSOL & AIR QUAL RES LAB,CINCINNATI,OH 45221. NR 37 TC 65 Z9 65 U1 1 U2 23 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 JUN PY 1996 VL 11 IS 6 BP 1552 EP 1561 DI 10.1557/JMR.1996.0194 PG 10 WC Materials Science, Multidisciplinary SC Materials Science GA UQ664 UT WOS:A1996UQ66400029 ER PT J AU Lavelle, JW Smith, DC AF Lavelle, JW Smith, DC TI Effects of rotation on convective plumes from line segment sources SO JOURNAL OF PHYSICAL OCEANOGRAPHY LA English DT Article ID TURBULENCE; COMPUTATION; OCEAN; MODEL AB Effects of rotation on finite-length line plumes are studied with a three-dimensional nonhydrostatic numerical model. Geophysical convection with this source geometry occurs, for example, as the result of fissure releases of hot hydrothermal fluids at the seafloor from terrestrial release of hot gases and ash during volcanic activity along fissures and in the descent from the sea surface of brines formed during freezing of ice leads at high latitudes. Here the model treats the case of a starring plume of dense fluid descending into a rotating environment. Results are compared with laboratory experiments so that the validity of the model, particularly the nonlinear subgrid-scale mixing formulation, might first be established. Differences in plumes caused by varying rotation rate, Omega, and buoyancy flux, B-0, are the primary focus, with experiments in fluid of depth h spanning a convective Rossby number [B-0(1/3)/(2 Omega h)] of 0.01-1.0. Rotation initiates spiraling of the descending plumes but it has little effect on the speed of plume descent; the latter depends on the strength of turbulent mixing. Low rotation rates allow the descending plume cap to be broad and the stem to be narrow. Higher rotation rates retard the lateral spread of the plume cap and widen the plume stem. Updraft at the stem edge is very much larger at higher rotation rates, and that appears to be instrumental in determining stem and cap width. Values of turbulent mixing coefficients within the plume are dependent on B-0 but not on Omega. Thus rotational effects on turbulence are not needed to account for differences in plume structure arising solely from Omega variation. Agreement between model and laboratory results did not occur without a nonlinear time- and space-dependent subgrid-scale mixing parameterization, suggesting that model applications to convective geophysical problems identified above require the same. C1 UNIV CALIF SANTA CRUZ,INST MARINE SCI,SANTA CRUZ,CA 95064. RP Lavelle, JW (reprint author), NOAA,PACIFIC MARINE ENVIRONM LAB,7600 SAND POINT WAY NE,SEATTLE,WA 98115, USA. NR 32 TC 12 Z9 12 U1 0 U2 0 PU AMER METEOROLOGICAL SOC PI BOSTON PA 45 BEACON ST, BOSTON, MA 02108-3693 SN 0022-3670 J9 J PHYS OCEANOGR JI J. Phys. Oceanogr. PD JUN PY 1996 VL 26 IS 6 BP 863 EP 872 DI 10.1175/1520-0485(1996)026<0863:EOROCP>2.0.CO;2 PG 10 WC Oceanography SC Oceanography GA UU486 UT WOS:A1996UU48600003 ER PT J AU Toggweiler, JR Tziperman, E Feliks, Y Bryan, K Griffies, SM Samuels, B AF Toggweiler, JR Tziperman, E Feliks, Y Bryan, K Griffies, SM Samuels, B TI Instability of the thermohaline circulation with respect to mixed boundary conditions: Is it really a problem for realistic models? Reply SO JOURNAL OF PHYSICAL OCEANOGRAPHY LA English DT Article AB The comment by Rahmstorf suggests that a numerical problem in Tziperman et al. (1994, TTFB) leads to a noisy E - P field that invalidates TTFB's conclusions. The authors eliminate the noise, caused by the Fourier filtering used in the model, and show that TTFB's conclusions are still valid. Rahmstorf questions whether a critical value in the freshwater forcing separates TTFB's stable and unstable runs. By TTFB's original definition, the unstable runs in both TTFB and in Rahmstorf's comment have most definitely crossed a stability transition point upon switching to mixed boundary conditions. Rahmstorf finally suggests that the instability mechanism active in TTFB is a fast convective mechanism, not the slow advective mechanism proposed in TTFB. The authors show that the timescale of the instability is, in fact, consistent with the advective mechanism. C1 WEIZMANN INST SCI,DEPT ENVIRONM SCI,IL-76100 REHOVOT,ISRAEL. PRINCETON UNIV,NOAA,GEOPHYS FLUID DYNAM LAB,PRINCETON,NJ 08542. ISRAEL INST BIOL RES,DEPT MATH,IL-70450 NESS ZIONA,ISRAEL. PRINCETON UNIV,ATMOSPHER & OCEAN SCI PROGRAM,PRINCETON,NJ 08544. NR 7 TC 5 Z9 5 U1 1 U2 2 PU AMER METEOROLOGICAL SOC PI BOSTON PA 45 BEACON ST, BOSTON, MA 02108-3693 SN 0022-3670 J9 J PHYS OCEANOGR JI J. Phys. Oceanogr. PD JUN PY 1996 VL 26 IS 6 BP 1106 EP 1110 DI 10.1175/1520-0485(1996)026<1106:R>2.0.CO;2 PG 5 WC Oceanography SC Oceanography GA UU486 UT WOS:A1996UU48600018 ER PT J AU Kamitakahara, WA AF Kamitakahara, WA TI Dynamics of Li-carbon and carbon solids SO JOURNAL OF PHYSICS AND CHEMISTRY OF SOLIDS LA English DT Article; Proceedings Paper CT 8th International Symposium on Intercalation Compounds CY MAY 28-JUN 01, 1995 CL VANCOUVER, CANADA SP Simon Fraser Univ, Conf Serv Dept DE amorphous materials; fullerenes; neutron scattering; elastic properties; microstructure ID AMORPHOUS-CARBON; GRAPHITE; SCATTERING; TRANSITION; SPECTRUM; PHONONS; C60 AB Neutron scattering methods have been used to measure vibrational densities of states (VDOS) for a variety of carbon solids, including diamond, graphite, glassy carbon, C-60 and a sputtered amorphous carbon sample. While glassy carbon has a VDOS very similar to that of graphite, a very different, almost featureless, spectrum was obtained in the case of sputtered a-C. Li-graphite intercalation compounds have also been studied in an experiment to investigate the dependence of shear properties on the concentration and degree of order in the Li substructure. RP Kamitakahara, WA (reprint author), NATL INST STAND & TECHNOL,DIV REACTOR RADIAT,GAITHERSBURG,MD 20899, USA. NR 25 TC 8 Z9 8 U1 0 U2 3 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD, ENGLAND OX5 1GB SN 0022-3697 J9 J PHYS CHEM SOLIDS JI J. Phys. Chem. Solids PD JUN-AUG PY 1996 VL 57 IS 6-8 BP 671 EP 676 DI 10.1016/0022-3697(95)00330-4 PG 6 WC Chemistry, Multidisciplinary; Physics, Condensed Matter SC Chemistry; Physics GA UU365 UT WOS:A1996UU36500004 ER PT J AU Suzuki, M Suzuki, IS Wiesler, DG Rosov, N AF Suzuki, M Suzuki, IS Wiesler, DG Rosov, N TI In-plane spin structure studies on MnCl2 graphite intercalation compounds SO JOURNAL OF PHYSICS AND CHEMISTRY OF SOLIDS LA English DT Article; Proceedings Paper CT 8th International Symposium on Intercalation Compounds CY MAY 28-JUN 01, 1995 CL VANCOUVER, CANADA SP Simon Fraser Univ, Conf Serv Dept DE neutron scattering; magnetic structure; phase transitions ID MNCL2-GRAPHITE AB The in-plane spin order of MnCl2 GIC with a mixture of stage-1 and stage-2 has been studied in the temperature range between 63 mK and 30 K by means of elastic neutron scattering. The magnetic Bragg reflections are observed below 7.5 K at the in-plane wavevector Q(parallel to) = {k(i)} and {a* +/- k(i)}, where a* is the in-plane reciprocal lattice vector of MnCl2 layers and k(i) (i = 1, 2) is the reciprocal lattice vector of the in-plane spin structure: \a*\=1.965 Angstrom(-1). This incommensurate in-plane spin structure occurs as a result of competition between ferromagnetic nearest neighbor (NN) intraplanar exchange interaction, and antiferromagnetic second and third NN interactions. C1 GEORGE WASHINGTON UNIV,DEPT PHYS,WASHINGTON,DC 20052. NATL INST STAND & TECHNOL,DIV REACTOR,GAITHERSBURG,MD 20899. RP Suzuki, M (reprint author), SUNY BINGHAMTON,DEPT PHYS,BINGHAMTON,NY 13902, USA. NR 5 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 0022-3697 J9 J PHYS CHEM SOLIDS JI J. Phys. Chem. Solids PD JUN-AUG PY 1996 VL 57 IS 6-8 BP 729 EP 732 DI 10.1016/0022-3697(95)00340-1 PG 4 WC Chemistry, Multidisciplinary; Physics, Condensed Matter SC Chemistry; Physics GA UU365 UT WOS:A1996UU36500013 ER PT J AU Glinka, CJ Nicol, JM Stucky, GD Ramli, E Margolese, D Huo, Q Higgins, JB Leonowicz, ME AF Glinka, C. J. Nicol, J. M. Stucky, G. D. Ramli, E. Margolese, D. Huo, Q. Higgins, J. B. Leonowicz, M. E. TI Small Angle Neutron Scattering Study of the Structure and Formation of MCM-41 Mesoporous Molecular Sieves SO JOURNAL OF POROUS MATERIALS LA English DT Article DE small angle neutron scattering; mesopores; molecular self-assembly; molecular sieves; MCM-41; liquid crystal templating AB The nanoscale structure and synthesis mechanisms of the MCM-41 class of inorganic mesoporous materials have been investigated by small angle neutron scattering (SANS). SANS measurements with solvents imbibed in the pores to vary the scattering contrast demonstrate that the low angle diffraction peaks from these materials are entirely due to the pore structure and that the pores are fully accessible to both aqueous and organic solvents. Static and shear flow SANS measurements on the concentrated cationic surfactant and silicate precursor solutions typically used in the synthesis of the mesopore materials indicate that the existence of preassembled supramolecular arrays that mimic the final pore structure is not essential for the synthesis of these materials. C1 [Glinka, C. J.; Nicol, J. M.] NIST, Gaithersburg, MD 20899 USA. [Stucky, G. D.; Ramli, E.; Margolese, D.; Huo, Q.] Univ Calif Santa Barbara, Dept Chem, Santa Barbara, CA 93106 USA. [Higgins, J. B.] Mobil Res & Dev Corp, Princeton, NJ 08543 USA. [Leonowicz, M. E.] Mobil Res & Dev Corp, Paulsboro, NJ 08066 USA. RP Glinka, CJ (reprint author), NIST, Gaithersburg, MD 20899 USA. FU National Science Foundation [DMR-9122444, DMR-9208511] FX We wish to acknowledge fruitful discussions with E. W. Kaler and J.J. Rush. The work at NIST utilized facilities partially supported by the National Science Foundation under Agreement No. DMR-9122444. The names of commercial products which appear in the text are for information only and do not constitute or imply endorsement by NIST for any purpose. GDS acknowledges support for this work from NSF Grant DMR-9208511. NR 15 TC 25 Z9 25 U1 0 U2 10 PU SPRINGER PI DORDRECHT PA VAN GODEWIJCKSTRAAT 30, 3311 GZ DORDRECHT, NETHERLANDS SN 1380-2224 J9 J POROUS MAT JI J. Porous Mat. PD JUN PY 1996 VL 3 IS 2 BP 93 EP 98 DI 10.1007/BF01186038 PG 6 WC Chemistry, Applied; Chemistry, Physical; Materials Science, Multidisciplinary SC Chemistry; Materials Science GA V20GQ UT WOS:000208128900004 ER PT J AU Wekell, JC Lorenzana, RM Hogan, M Barnett, H AF Wekell, JC Lorenzana, RM Hogan, M Barnett, H TI Survey of paralytic shellfish poison and domoic acid in Puget Sound predatory gastropods SO JOURNAL OF SHELLFISH RESEARCH LA English DT Article DE paralytic shellfish poison; gastropods; domoic acid AB Two predatory gastropods, moonsnails (Polinices lewissi) and frilled dogwinkles (Nucella lamellosa), were collected in the Puget Sound basin in the summer and fall of 1994 and in the spring of 1995. Analyses indicated the presence of paralytic shellfish poison (PSP) toxins in these gastropods in all sampling periods; however, no domoic acid was detected in any of the samples. Other species of molluscan shellfish and a species of crustacea, considered possible prey and/or indicators of PSP in the area, were also collected. In September 1994, levels of PSP in moonsnails collected from Agate Passage averaged 145 mu g of saxitoxin (STX) equivalents (equiv.)/100 g; butter clams taken from the same area at the same time averaged 73 mu g of STX equiv./100 g. In October 1994, when a local monitoring station indicated the presence of PSP in Mystery Bay, a collection and PSP analyses of molluscan shellfish yielded the following average values: dogwinkle (N. lamellosa) averaged 72) mu g of STX equiv./100 g; blue mussels (Mytilus edulis), 652 mu g of STX equiv./100 g; Pacific oyster (Crassostrea gigas), 45 mu g of STX equiv./100 g; northern horse mussel (Modiolus modiolus, 48 mu g Of STX equiv./100 g; and snails (Searlesia dira), 50 mu g of STX equiv./100 g. In April 1995, another collection and analyses of shellfish from Agate Passage showed that moonsnails averaged 48 mu g of STX equiv./100 g, and butter clams (Saxidomus giganteus) averaged 35 mu g of STX equiv./100 g (range, 0-77 mu g of STX equiv./100 g); Pacific littleneck clams (Protothaca staminea) and red rock crab (Cancer productus) did not contain PSP toxin. Modifications of the sample preparation methods required for the analyses of samples are described. C1 US EPA, SEATTLE, WA 98101 USA. SOUTHAMPTON COLL, LIU, DIV NAT SCI, SOUTHAMPTON, NY 11968 USA. RP Wekell, JC (reprint author), NOAA, NATL MARINE FISHERIES SERV, NW FISHERIES SCI CTR, UTILIZAT RES DIV, 2725 MONTLAKE BLVD E, SEATTLE, WA 98112 USA. NR 18 TC 7 Z9 7 U1 0 U2 7 PU NATL SHELLFISHERIES ASSOC PI GROTON PA C/O DR. SANDRA E. SHUMWAY, UNIV CONNECTICUT, 1080 SHENNECOSSETT RD, GROTON, CT 06340 USA SN 0730-8000 J9 J SHELLFISH RES JI J. Shellfish Res. PD JUN PY 1996 VL 15 IS 2 BP 231 EP 236 PG 6 WC Fisheries; Marine & Freshwater Biology SC Fisheries; Marine & Freshwater Biology GA UX154 UT WOS:A1996UX15400004 ER PT J AU Luecke, WE French, JD AF Luecke, WE French, JD TI Sources of strain-measurement error in flag-based extensometry SO JOURNAL OF THE AMERICAN CERAMIC SOCIETY LA English DT Article ID TENSILE CREEP; SILICON-NITRIDE; COMPOSITES; CERAMICS AB This paper examines the sources of error in strain measurement using flag-based extensometry that uses either scanning laser or electrooptical extensometers, These errors fall into two groups: errors in measuring the true gauge length of the specimen, which arise from the method of attachment of the flags, and errors arising from unanticipated distortions of the specimen during testing. The sources of errors of the first type include gauge-length errors from nonparallel flags and uncertainties in the true attachment point of the flag, During the test, strain-measurement errors of the second type can arise from horizontal translation of nonparallel flags, flag rotation that is induced by slippage, and flag motion from bending of the gauge length, Proper care can minimize the effect of these potential errors, so that flag-based extensometry can give accurate strain measurement, if appropriate precautions are taken, Measurements on silicon nitride indicate that the strain measurements are accurate to better than 10%. RP Luecke, WE (reprint author), NIST,MAT SCI & ENGN LAB,GAITHERSBURG,MD 20899, USA. OI Luecke, William/0000-0003-0587-4500 NR 33 TC 19 Z9 19 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 JUN PY 1996 VL 79 IS 6 BP 1617 EP 1626 DI 10.1111/j.1151-2916.1996.tb08773.x PG 10 WC Materials Science, Ceramics SC Materials Science GA UT219 UT WOS:A1996UT21900028 ER PT J AU Murray, A Mecklenburg, MF Fortunko, CM Green, RE AF Murray, A Mecklenburg, MF Fortunko, CM Green, RE TI Air-coupled ultrasonic system: A new technology for detecting flaws in paintings on wooden panels SO JOURNAL OF THE AMERICAN INSTITUTE FOR CONSERVATION LA English DT Article AB Air-coupled ultrasound, a noncontact, nondestructive testing technique, has detected splits, checks, delaminations, cleavage, and voids in various materials. The system has inspected highly anisotropic and inhomogeneous materials such as wood and wood products, with surfaces layers of gesso, gesso and linen, paper, and wood veneer. Two paintings were tested; one was an oak-cradled panel painting and the other was illustration board mounted on hardboard. The air-coupled ultrasound technique yielded information additional to that provided by visual examination, xeroradiography, and infrared thermography. C1 SMITHSONIAN INST,CONSERVAT ANALYT LAB,WASHINGTON,DC 20560. NATL INST STAND & TECHNOL,DIV MAT RELIABIL,MAT SCI & ENGN LAB,COMPOSITE MAT CHARACTERIZAT GRP,BOULDER,CO 80303. JOHNS HOPKINS UNIV,DEPT MAT SCI & ENGN,BALTIMORE,MD 21218. JOHNS HOPKINS UNIV,CTR NONDESTRUCT EVALUAT,BALTIMORE,MD 21218. RP Murray, A (reprint author), QUEENS UNIV,ART CONSERVAT PROGRAM,CTR EXTENS,KINGSTON,ON K7L 3N6,CANADA. NR 13 TC 8 Z9 8 U1 0 U2 3 PU AMER INST CONSERVATION HISTORIC ARTISTIC WORKS PI WASHINGTON PA 1717 K ST, NW, STE 301, WASHINGTON, DC 20006 SN 0197-1360 J9 J AM INST CONSERV JI J. Am. Inst. Conserv. PD SUM PY 1996 VL 35 IS 2 BP 145 EP 162 DI 10.2307/3179993 PG 18 WC Humanities, Multidisciplinary SC Arts & Humanities - Other Topics GA VF436 UT WOS:A1996VF43600005 ER PT J AU Collins, BL AF Collins, BL TI The development of a reliable, valid, and simple office lighting survey SO JOURNAL OF THE ILLUMINATING ENGINEERING SOCIETY LA English DT Editorial Material RP Collins, BL (reprint author), UNIV COLORADO,NIST,BOULDER,CO 80309, USA. NR 0 TC 0 Z9 0 U1 0 U2 1 PU ILLUMINAT ENG SOC NORTH AMER PI NEW YORK PA 120 WALL ST, 17TH FL, NEW YORK, NY 10005-4001 SN 0099-4480 J9 J ILLUM ENG SOC JI J. Illum. Eng. Soc. PD SUM PY 1996 VL 25 IS 2 BP 33 EP 33 PG 1 WC Optics SC Optics GA VB269 UT WOS:A1996VB26900012 ER PT J AU Collins, B AF Collins, B TI Illuminance selection based on visual performance - And other fairy stories SO JOURNAL OF THE ILLUMINATING ENGINEERING SOCIETY LA English DT Editorial Material RP Collins, B (reprint author), UNIV COLORADO,NIST,BOULDER,CO 80309, USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU ILLUMINAT ENG SOC NORTH AMER PI NEW YORK PA 120 WALL ST, 17TH FL, NEW YORK, NY 10005-4001 SN 0099-4480 J9 J ILLUM ENG SOC JI J. Illum. Eng. Soc. PD SUM PY 1996 VL 25 IS 2 BP 48 EP 48 PG 1 WC Optics SC Optics GA VB269 UT WOS:A1996VB26900018 ER PT J AU Sanders, PA Collins, BL AF Sanders, PA Collins, BL TI Post-occupancy evaluation of the Forrestal building SO JOURNAL OF THE ILLUMINATING ENGINEERING SOCIETY LA English DT Article AB A post-occupancy evaluation was performed on the Department of Energy Headquarters Building (the Forrestal Building) in Washington, DC. The lighting in the building was retrofited with new more energy-efficient components to meet energy guidelines. Occupant responses to the indoor environmental conditions, particularly the lighting, were studied to determine the impact of the relighting on the building inhabitants. In addition, physical measures of the lighting and other environmental conditions before and after the relighting were compared. The post-occupancy evaluation employed a questionnaire about the environmental conditions and physical measures of the space (lighting, space, noise, temperature, etc.). A total of 244/220 people participated (before and after the relighting, respectively). Physical measures were taken at 100 work stations before the relighting and 75 after. Analysis of the physical measure ment data indicated generally higher lighting levels with more even distribution of luminances in the offices. Occupant response to the changes in the lighting was generally quite positive. The relighting was perceived to have improved the appearance of the building substantially, as well as the lighting within individual work stations. C1 NATL INST STAND & TECHNOL,GAITHERSBURG,MD 20899. RP Sanders, PA (reprint author), GE LIGHTING,1975 NOBLE RD,CLEVELAND,OH 44112, USA. NR 28 TC 3 Z9 3 U1 1 U2 3 PU ILLUMINAT ENG SOC NORTH AMER PI NEW YORK PA 120 WALL ST, 17TH FL, NEW YORK, NY 10005-4001 SN 0099-4480 J9 J ILLUM ENG SOC JI J. Illum. Eng. Soc. PD SUM PY 1996 VL 25 IS 2 BP 89 EP & PG 14 WC Optics SC Optics GA VB269 UT WOS:A1996VB26900038 ER PT J AU Hohn, AA Read, AJ Fernandez, S Vidal, O Findley, LT AF Hohn, AA Read, AJ Fernandez, S Vidal, O Findley, LT TI Life history of the vaquita, Phocoena sinus (Phocoenidae, Cetacea) SO JOURNAL OF ZOOLOGY LA English DT Article ID HARBOR PORPOISES; MATURITY; DOLPHINS; GROWTH; RATES; FUNDY; BAY AB The vaquita, Phocoena sinus, is the most endangered marine cetacean primarily due to incidental mortality in fishing nets. We examined a sample of 56 vaquitas to study the life history of this poorly known species. The age structure was bimodal, with 62% of the specimens from 0-2 years and 31% from 11-16 years; the sample contained no specimens from ages 3-6 years. The oldest individual was estimated to be 21 years old. All specimens less than three years old were sexually immature and all greater than six years old were mature. The asymptotic length of females (140.6 cm) was significantly greater than that of males (134.9 cm), although no difference was detected in asymptotic girth or body mass. Reproduction is synchronous: births occurred from late February to early April and maximum testes activity occurred from mid-March through to at least mid-April. Our observations from this small sample suggest that the calving interval is greater than one year. The sample was too small for many quantitative analyses, although it appears that lifespan, patterns of growth, age at sexual maturation. seasonal reproduction, and large testis size are similar to the harbour porpoise, P. phocoena, in a highly exploited and well-studied population from the Bay of Fundy. A significant difference, however, is that harbour porpoise females give birth annually, indicating that the rate of increase in the vaquita population is likely to be lower than that in the harbour porpoise. Without immediate cessation of fishing pressure, this fragile population will collapse, resulting in extinction of the vaquita. C1 NATL MARINE FISHERIES SERV,OFF PROTECTED RESOURCES,SILVER SPRING,MD 20910. WOODS HOLE OCEANOG INST,WOODS HOLE,MA 02543. INST TECNOL ESTUDIOS SUPER MONTERREY,GUAYMAS 85400,SONORA,MEXICO. RI Hohn, Aleta/G-2888-2011 OI Hohn, Aleta/0000-0002-9992-7062 NR 35 TC 34 Z9 37 U1 4 U2 21 PU OXFORD UNIV PRESS UNITED KINGDOM PI OXFORD PA WALTON ST JOURNALS DEPT, OXFORD, ENGLAND OX2 6DP SN 0952-8369 J9 J ZOOL JI J. Zool. PD JUN PY 1996 VL 239 BP 235 EP 251 PN 2 PG 17 WC Zoology SC Zoology GA VB043 UT WOS:A1996VB04300003 ER PT J AU Wanninkhof, R Knox, M AF Wanninkhof, R Knox, M TI Chemical enhancement of CO2 exchange in natural waters SO LIMNOLOGY AND OCEANOGRAPHY LA English DT Article ID CARBON-DIOXIDE EXCHANGE; AIR-SEA INTERFACE; GAS-EXCHANGE; FLUX; SEAWATER AB Exchange of CO2 under low turbulence conditions and high pH can be enhanced by hydration reactions of CO2 with hydroxide ions and water molecules in the boundary layer. A series of held experiments was performed on several lakes, including alkaline closed-basin lakes, using enclosures (helmets) to study the enhancement process in nature. In addition, the enhancement of CO2 exchange was studied in laboratory experiments with freshwater and seawater. The results of the experiments are compared with published theoretical calculations. Within the experimental uncertainties and shortcomings of the chemical enhancement models, reasonable agreement was observed between experimental and theoretical results for seawater. The experiments indicate, in accordance with theory, that chemical enhancement has a minor effect on air-sea gas exchange of CO2 under average oceanic turbulence conditions. However, for the equatorial CO2 source regions, with high temperatures and low winds, the calculated CO2 enhancement amounts to 4-8% of the total exchange. The observations on lakes show poorer agreement with models, which is attributed to experimental uncertainty and poor characterization of the chemistry of the lake waters. The experiments show that chemical enhancement of CO2 is ubiquitous for the alkaline closed-basin lakes with enhancements of up to a factor of three. RP Wanninkhof, R (reprint author), NOAA,AOML,OCEAN CHEM DIV,4301 RICKENBACKER CAUSEWAY,MIAMI,FL 33149, USA. NR 36 TC 96 Z9 102 U1 2 U2 29 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 JUN PY 1996 VL 41 IS 4 BP 689 EP 697 PG 9 WC Limnology; Oceanography SC Marine & Freshwater Biology; Oceanography GA VD306 UT WOS:A1996VD30600010 ER PT J AU Arkoosh, MR Clemons, E Huffman, P Sanborn, HR Casillas, E Stein, JE AF Arkoosh, MR Clemons, E Huffman, P Sanborn, HR Casillas, E Stein, JE TI Evaluation of the leukoproliferative response of English sole (Pleuronectes vetulus) as a biomarker for immune dysfunction SO MARINE ENVIRONMENTAL RESEARCH LA English DT Article; Proceedings Paper CT 8th International Symposium on Pollutant Responses in Marine Organisms (PRIMO 9) CY APR 02-05, 1995 CL PACIFIC GROVE, CA SP Univ Calif Davis, US EPA, Ctr Ecol Hlth Res, Univ Calif Davis, Superfund Basic Sci Res Program, NOAA, Natl Marine Fisheries Serv, NW Fisheries Sci Ctr, State Calif Fish & Gam Off Oil Spill Prevent & Response, Vet Serv, US Natl Inst Environm Hlth Sci, Monterey Bay Aquarium, Calif Sea Grant Program ID INVITRO AB The leukoproliferative (LP) response of splenic leukocytes from the marine benthic fish, English sole (Pleuronectes vetulus), stimulated with the mitogens lipopolysaccharide (LPS), concanavalin A (Con A), and pokeweed mitogen (PWM) was examined as a biomarker of immunotoxic effects, English sole were exposed to an organic-solvent extract of a sediment contaminated with polycyclic aromatic compounds (PACs) or placed on a reference sediment modified with the PAC contaminated sediment. For both treatments, English sole had an augmented LP response to Con A, no significant change in the response to LPS, and the LP response to PWM showed no consistent relationship to exposure to PACs. In a field study, English sole from a contaminated site had a significantly augmented LP response to Con A and PWM. Fish from a non-urban site also had an augmented LP response to Con A and to LPS relative to fish from another non-urban reference site. Overall, the results demonstrated that although the LP response in splenic leukocytes of English sole to Con A was linked to contaminant exposure, the LP response to Con A did not exhibit high specificity as an indicator of chemical contaminant exposure. However, the concerted use of Con A, LPS, and PWM allowed for identification of apparent chemical-contaminant induced alterations of the LP response in English sole from an urban area of Puget Sound. Published by Elsevier Science Ltd. RP Arkoosh, MR (reprint author), NATL MARINE FISHERIES SERV,ENVIRONM CONSERVAT DIV,NW FISHERIES SCI CTR,NOAA,2725 MONTLAKE BLVD E,SEATTLE,WA 98112, USA. NR 9 TC 2 Z9 2 U1 0 U2 0 PU ELSEVIER SCI LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD, OXON, ENGLAND OX5 1GB SN 0141-1136 J9 MAR ENVIRON RES JI Mar. Environ. Res. PD JUN-OCT PY 1996 VL 42 IS 1-4 BP 181 EP 186 DI 10.1016/0141-1136(95)00065-8 PG 6 WC Environmental Sciences; Marine & Freshwater Biology; Toxicology SC Environmental Sciences & Ecology; Marine & Freshwater Biology; Toxicology GA UU369 UT WOS:A1996UU36900029 ER PT J AU Ostrom, CL Gittings, SR AF Ostrom, CL Gittings, SR TI Flower Garden Banks National Marine Sanctuary: Platforms, partnerships, and resource protection SO MARINE TECHNOLOGY SOCIETY JOURNAL LA English DT Article AB Innovative cooperative efforts between the Flower Garden Banks National Marine Sanctuary, other Federal and State government programs, academic institutions, non-governmental organisations, and the sport diving and petroleum industries have been essential for the successful protection and management of this unique marine environment. An example of one partnership between the Sanctuary, scientists, and Mobil Exploration and Producing U.S. involves the use of a natural gas production platform located within the Sanctuary for research and training programs. But the future is gloomy for this productive alliance, as the platform's production life is nearing an end. The facility's imminent removal poses challenges for agencies and operators charged with protecting the fragile resources of the Flower Gardens. C1 NATL MARINE SANCTUARY,FLOWER GARDEN BANKS,BRYAN,TX. RP Ostrom, CL (reprint author), NOAA,NATL OCEAN SERV,SANCTUARIES & RESERVES DIV,SILVER SPRING,MD, USA. NR 8 TC 0 Z9 0 U1 0 U2 1 PU MARINE TECHNOLOGY SOC INC PI WASHINGTON PA C/O I CLAYION MATTHEWS, 1828 L ST, NW, 9TH FL, WASHINGTON, DC 20036 SN 0025-3324 J9 MAR TECHNOL SOC J JI Mar. Technol. Soc. J. PD SUM PY 1996 VL 30 IS 2 BP 3 EP 7 PG 5 WC Engineering, Ocean; Oceanography SC Engineering; Oceanography GA VG427 UT WOS:A1996VG42700001 ER PT J AU Timko, RE Woody, CE Ladner, RD Riley, RE AF Timko, RE Woody, CE Ladner, RD Riley, RE TI Near-real-time ocean color measurements from fixed platforms - A design SO MARINE TECHNOLOGY SOCIETY JOURNAL LA English DT Article ID BIGHT AB The Ambrose Light Tower was selected as a technology development site for the National Aeronautics and Space Administration (NASA) Sea-viewing Wide Field-of-view Sensor (Sea-WiFS) program for ocean color. Optical sensors and other supporting oceanographic instrumentation will be mounted on the tower leg to develop an operational capability for validation, of SeaWiFS data for coastal oceans. The Ambrose Tower, an established weather station, is part of the National Data Buoy Center's (NDBC) Coastal-Marine Automated Network (C-MAN). Simultaneous sampling of meteorological data and in-water optical observations will provide an important component to understanding ocean physics as it relates to variability in productivity. C1 COMP SCI CORP,BAY ST LOUIS,MS. RP Timko, RE (reprint author), NATL DATA BUOY CTR,BAY ST LOUIS,MS, USA. NR 15 TC 2 Z9 2 U1 0 U2 0 PU MARINE TECHNOLOGY SOC INC PI WASHINGTON PA C/O I CLAYION MATTHEWS, 1828 L ST, NW, 9TH FL, WASHINGTON, DC 20036 SN 0025-3324 J9 MAR TECHNOL SOC J JI Mar. Technol. Soc. J. PD SUM PY 1996 VL 30 IS 2 BP 33 EP 38 PG 6 WC Engineering, Ocean; Oceanography SC Engineering; Oceanography GA VG427 UT WOS:A1996VG42700005 ER PT J AU Morris, DS AF Morris, DS TI Seal predation at salmon farms in Maine, an overview of the problem and potential solutions SO MARINE TECHNOLOGY SOCIETY JOURNAL LA English DT Article AB Salmon aquaculture facilities in Downeast Maine are occasionally attacked by harbor seals and gray seals. The predators kill and injure valuable fish and may damage net-pens allowing farm-fish to escape. Industry proponents claim up to 10% of the industry's farmgate value is lost to seal predation. In addition to financial impacts, the escapement of cultured fish may pose a threat to indigenous Atlantic salmon stocks. Salmon growers in Maine employ a variety of predator control measures-netting systems, underwater acoustic devices and pyrotechnics-but no battery of protections seems to be 100% effective. In the past, those seals who could defeat deterrence strategies would be targeted for lethal, removal. Recent amendments to the Marine Mammal protection Act (MMPA), however now prohibit the killing of depredating seals. This paper provides an overview of the problem, surveys technological and non-technological solutions and mitigating measures, and describes the work of a stakeholder task force convened by the National Marine Fisheries Service to investigate the matter. RP Morris, DS (reprint author), NATL MARINE FISHERIES SERV,GLOUCESTER,MA 01930, USA. NR 18 TC 16 Z9 17 U1 0 U2 12 PU MARINE TECHNOLOGY SOC INC PI WASHINGTON PA C/O I CLAYION MATTHEWS, 1828 L ST, NW, 9TH FL, WASHINGTON, DC 20036 SN 0025-3324 J9 MAR TECHNOL SOC J JI Mar. Technol. Soc. J. PD SUM PY 1996 VL 30 IS 2 BP 39 EP 43 PG 5 WC Engineering, Ocean; Oceanography SC Engineering; Oceanography GA VG427 UT WOS:A1996VG42700006 ER PT J AU Crawford, JE Cruickshank, MJ Smolowitz, R Wiltshire, JC Bash, JF Parker, B AF Crawford, JE Cruickshank, MJ Smolowitz, R Wiltshire, JC Bash, JF Parker, B TI State of technology report - Marine Resources Division SO MARINE TECHNOLOGY SOCIETY JOURNAL LA English DT Article C1 MARINE MINERALS TECHNOL CTR,HONOLULU,HI. COONAMESSETT FARM,FALMOUTH,MA. UNIV HAWAII,HONOLULU,HI 96822. UNIV RHODE ISL,NATL OCEANOG LAB SYST,NARRAGANSETT,RI. NOAA,NATL OCEAN SERV,SILVER SPRING,MD. RP Crawford, JE (reprint author), MARINE RESOURCES DIV,CARSON CITY,NV, USA. NR 0 TC 0 Z9 0 U1 0 U2 1 PU MARINE TECHNOLOGY SOC INC PI WASHINGTON PA C/O I CLAYION MATTHEWS, 1828 L ST, NW, 9TH FL, WASHINGTON, DC 20036 SN 0025-3324 J9 MAR TECHNOL SOC J JI Mar. Technol. Soc. J. PD SUM PY 1996 VL 30 IS 2 BP 50 EP 57 PG 8 WC Engineering, Ocean; Oceanography SC Engineering; Oceanography GA VG427 UT WOS:A1996VG42700008 ER PT J AU Busch, WS AF Busch, WS TI Use of offshore production platforms for atmospheric, oceanographic, and environmental research SO MARINE TECHNOLOGY SOCIETY JOURNAL LA English DT Editorial Material RP Busch, WS (reprint author), NOAA,OFF GLOBAL PROGRAMS,SILVER SPRING,MD 20910, USA. NR 0 TC 0 Z9 0 U1 0 U2 2 PU MARINE TECHNOLOGY SOC INC PI WASHINGTON PA C/O I CLAYION MATTHEWS, 1828 L ST, NW, 9TH FL, WASHINGTON, DC 20036 SN 0025-3324 J9 MAR TECHNOL SOC J JI Mar. Technol. Soc. J. PD SUM PY 1996 VL 30 IS 2 BP 58 EP 59 PG 2 WC Engineering, Ocean; Oceanography SC Engineering; Oceanography GA VG427 UT WOS:A1996VG42700009 ER PT J AU Chopra, HD Roytburd, AL Wuttig, M AF Chopra, HD Roytburd, AL Wuttig, M TI Temperature-dependent deformation of polydomain phases in an In-22.5 at pct Tl shape memory alloy SO METALLURGICAL AND MATERIALS TRANSACTIONS A-PHYSICAL METALLURGY AND MATERIALS SCIENCE LA English DT Article AB Mechanically synthesized, reproducible polytwins of an In-22.5 at. pct Tl shape memory alloy were studied quantitatively for their deformation behavior due to bending stresses, in the ferroelastic and rubberlike temperature regime, with in situ video recordings of the evolving mesostructure. The experimental ratios of the twin modulus, E(T), to the elastic modulus, E(el), were two orders of magnitude higher than the theoretically calculated values. Further investigations to reconcile this discrepancy revealed a fine substructure within each domain of the polytwin. The response coefficient of this substructure, rather than the elastic modulus, was found to be the controlling deformation parameter for the polytwin. Theoretically predicted results were modified, which established a close agreement with the experimental results. C1 UNIV MARYLAND,DEPT MAT & NUCL ENGN,COLLEGE PK,MD 20742. RP Chopra, HD (reprint author), NATL INST STAND & TECHNOL,GAITHERSBURG,MD 20877, USA. NR 21 TC 9 Z9 9 U1 1 U2 1 PU MINERALS METALS MATERIALS SOC PI WARRENDALE PA 420 COMMONWEALTH DR, WARRENDALE, PA 15086 SN 1073-5623 J9 METALL MATER TRANS A JI Metall. Mater. Trans. A-Phys. Metall. Mater. Sci. PD JUN PY 1996 VL 27 IS 6 BP 1695 EP 1700 DI 10.1007/BF02649827 PG 6 WC Materials Science, Multidisciplinary; Metallurgy & Metallurgical Engineering SC Materials Science; Metallurgy & Metallurgical Engineering GA UR669 UT WOS:A1996UR66900027 ER PT J AU Sikora, M Sol, H Begelman, MC Madejski, GM AF Sikora, M Sol, H Begelman, MC Madejski, GM TI Radiation drag in relativistic active galactic nucleus jets SO MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY LA English DT Article DE plasmas; radiation mechanisms, nonthermal; methods, analytical galaxies, active; galaxies, jets; galaxies, nuclei ID DOUBLE RADIO-SOURCES; ACCRETION DISKS; MODEL; COLLIMATION; INJECTION; BLAZARS; ENERGY; PLASMA AB We present the first comprehensive study of radiation drag imposed on both cold and relativistic plasma components in a jet propagating at relativistic speeds through a dense radiation field, Earlier work showed that radiation drag acting on the cold plasma alone drops very fast with distance from the central source and can affect the jet dynamics only very close to the central source (up to 10-30 gravitational radii), and only if the jet plasma is strongly dominated by electron-positron pairs. In the case of radiation drag acting on a jet through relativistic electrons/positrons, the distance dependence can be much flatter, actually being determined by the distance dependence of the injection rate of relativistic particles. However, we show that such radiation drag can be dynamically important only for magnetically dominated jets in which the injection luminosity of relativistic electrons/positrons exceeds the kinetic luminosity of the jet, Our studies are performed using a radiation tensor formalism, which is the most suitable and elegant method for calculating both forces and cooling rates resulting from Compton scattering of an ambient radiation field by relativistic plasma in a jet. Simple analytic formulae, derived using this method, allow one to make quick estimates of dynamical and radiative effects resulting from the interaction of relativistic jets with different external radiation held distributions. C1 DEPT ASTROPHYS RELATIVISTE & COSMOL,MEUDON,FRANCE. UNIV COLORADO,JOINT INST LAB ASTROPHYS,BOULDER,CO 80309. NIST,BOULDER,CO 80309. UNIV COLORADO,DEPT ASTROPHYS PLANETARY & ATMOSPHER SCI,BOULDER,CO 80309. NASA,GODDARD SPACE FLIGHT CTR,GREENBELT,MD 20771. RP Sikora, M (reprint author), NICHOLAS COPERNICUS ASTRON CTR,BARTYCKA 18,PL-00716 WARSAW,POLAND. NR 32 TC 67 Z9 68 U1 0 U2 1 PU BLACKWELL SCIENCE LTD PI OXFORD PA OSNEY MEAD, OXFORD, OXON, ENGLAND OX2 0EL SN 0035-8711 J9 MON NOT R ASTRON SOC JI Mon. Not. Roy. Astron. Soc. PD JUN 1 PY 1996 VL 280 IS 3 BP 781 EP 796 PG 16 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA UP516 UT WOS:A1996UP51600014 ER PT J AU Rotunno, R Bao, JW AF Rotunno, R Bao, JW TI A case study of cyclogenesis using a model hierarchy SO MONTHLY WEATHER REVIEW LA English DT Article ID ZONALLY VARYING FLOW; BAROCLINIC WAVES; UPSTREAM DEVELOPMENT; B CYCLOGENESIS; INSTABILITY; BEHAVIOR; DISSIPATION; DOWNSTREAM; EVOLUTION; CYCLONES AB It is universally agreed that cyclogenesis in midlatitudes occurs through baroclinic conversion of the potential energy available from an initial state. The mechanical process by which that conversion takes place is a perennial subject of discussion. At least as far back as the 1950s, it was recognized that in any practical forecast problem, the initial condition is influential. Observational research continues to confirm the prevalence of tropopause-level perturbations preceding surface cyclogenesis. The observations also suggest that the growing disturbances have time-varying vertical structures. Relating these observations to the classical linear theory of baroclinic instability is not immediately obvious since, in the latter, the precise form of the initial condition is not important, and the theory predicts cyclogenesis with a fixed-in-time vertical structure. These differences between theory and observations are but a few of the many that have been recognized and treated in modified theories of baroclinic instability. We attempt herein to draw a closer connection between the modified theories and observations by performing a case study using a hierarchy of models of decreasing complexity. C1 NOAA,CIRES,BOULDER,CO. RP Rotunno, R (reprint author), NATL CTR ATMOSPHER RES,MMM DIV,POB 3000,BOULDER,CO 80307, USA. NR 44 TC 49 Z9 49 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 JUN PY 1996 VL 124 IS 6 BP 1051 EP 1066 DI 10.1175/1520-0493(1996)124<1051:ACSOCU>2.0.CO;2 PG 16 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA UP593 UT WOS:A1996UP59300002 ER PT J AU Kanamitsu, M Saha, S AF Kanamitsu, M Saha, S TI Systematic tendency error in budget calculations SO MONTHLY WEATHER REVIEW LA English DT Article ID DATA ASSIMILATION SYSTEM; DIAGNOSIS; HEAT AB Atmospheric budget calculations suffer from various observational and numerical errors. This paper demonstrates that all budget calculations applied to a large number of samples suffer from additional errors originating from systematic tendency errors of the budget equation used. Quantitative evaluation of this systematic tendency error for various types of budget computations showed that the systematic tendency errors are generally comparable in magnitude to the leading terms in the budget equations. Because of this error, the calculated budget does not satisfy conservation properties under steady conditions. C1 NATL CTR ENVIRONM PREDICT,ENVIRONM MODELING CTR,WASHINGTON,DC 20233. RP Kanamitsu, M (reprint author), NATL CTR ENVIRONM PREDICT,CLIMATE PREDICT CTR,W-NP51,WWB ROOM 606,WASHINGTON,DC 20233, USA. NR 31 TC 21 Z9 25 U1 0 U2 0 PU AMER METEOROLOGICAL SOC PI BOSTON PA 45 BEACON ST, BOSTON, MA 02108-3693 SN 0027-0644 J9 MON WEATHER REV JI Mon. Weather Rev. PD JUN PY 1996 VL 124 IS 6 BP 1145 EP 1160 DI 10.1175/1520-0493(1996)124<1145:STEIBC>2.0.CO;2 PG 16 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA UP593 UT WOS:A1996UP59300008 ER PT J AU Ralph, FM AF Ralph, FM TI Observations of 250-km-wavelength clear-air eddies and 750-km-wavelength mesocyclones associated with a synoptic-scale midlatitude cyclone SO MONTHLY WEATHER REVIEW LA English DT Article ID MESOSCALE; TROPOSPHERE; INSTABILITY AB Satellite images of a decaying synoptic-scale cyclone over the North Pacific reveal two distinct types of multiple mesoscale cyclonic disturbances. The approximate positions of these disturbances within the synoptic scale cyclone are determined using analyses from an operational global-scale numerical model. One type, a set of four 250-km-wavelength eddies, occurred in dear air and represent perturbations within the cyclonic shear side of a 40-45 m s(-1) upper-level jet-front system. Their propagation at 28.5 +/- 3.5 m s(-1) roughly matched the wind speed and direction within the jet at their position and provided evidence of stretching deformation along their axis. Their growth is documented over 18 h, and is measured in terms of horizontal displacements of a preexisting moisture boundary in water vapor imagery. Their e-folding time increased from 6 to 9 h as horizontal displacements exceeded 100 km and horizontal billows indicative of wave breaking formed. The billow-like structures most likely represent areas of enhanced mixing of stratospheric acid tropospheric air by means of a quasi-horizontal process acting in the vicinity of a tropopause fold. Because they developed in a region of significant horizontal shear and because the absence of clouds suggests vertical motions were small or absent, the behavior of these eddies is consistent with barotropic instability on a 50-km-wide shear zone or potential vorticity strip. The other type, a set of five 750-km-wavelength cyclonic disturbances (mesocyclones), is also evident in the satellite images, but because they modulated the cloud field they appear in both the WV and infrared images. They wrapped fully around the synoptic-scale cyclone, forming a wavenumber 5 perturbation that later became a wavenumber 4 perturbation propagating cyclonically about its center at 19 +/- 1 m s(-1) and likely formed on an occluded front. Two of these waves are distinguished by the development of their own comma clouds, indicating they had deep vertical circulations and suggesting that moist baroclinic instability or CISK was active. These 750-km-wavelength mesocyclones most likely affected the deformation and shear along the upper front, which could have modified the barotropic stability of the region, and thus influenced where the 250-km-wavelength eddies formed. RP Ralph, FM (reprint author), NOAA,ERL,ENVIRONM TECHNOL LAB,OAR,R-E-ET7,325 BROADWAY,BOULDER,CO 80303, USA. NR 22 TC 9 Z9 9 U1 1 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 JUN PY 1996 VL 124 IS 6 BP 1199 EP 1210 PG 12 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA UP593 UT WOS:A1996UP59300011 ER PT J AU Douglas, MW Li, SH AF Douglas, MW Li, SH TI Diurnal variation of the lower-tropospheric flow over the Arizona low desert from SWAMP-1993 observations SO MONTHLY WEATHER REVIEW LA English DT Article ID ARABIAN HEAT LOW; UNITED-STATES; NORTH-AMERICA; PRECIPITATION; MONSOON; BUDGET AB This paper describes the tropospheric circulation over the lower deserts of Arizona, California, and northwestern Mexico using observations from a special rawinsonde network operated during July and August as part of the 1993 Southwest Area Monsoon Project. The observations show that the flow over the low desert is diffluent, divergent, and upslope during the afternoon and confluent, weakly convergent, and downslope or slope parallel in the early morning hours. This diurnal cycle may help to explain the observed tendency for summer thunderstorms to occur most frequently over the low desert during the nighttime. Despite the relatively short observation interval (18 days), the authors show that this period is similar to multiyear mean conditions during July and August. A heat budget indicates that radiative heating in the lower troposphere over the desert is approximately balanced by the influx of cooler air from over the Gulf of California but uncertainties in the estimates of vertical motion and horizontal temperature advection make the budget uncertain in the middle troposphere. C1 CHINESE ACAD METEOROL SCI,BEIJING,PEOPLES R CHINA. RP Douglas, MW (reprint author), NOAA,ENVIRONM RES LAB,NATL SEVERE STORMS LAB,1313 HALLEY CIRCLE,NORMAN,OK 73069, USA. NR 21 TC 28 Z9 28 U1 0 U2 0 PU AMER METEOROLOGICAL SOC PI BOSTON PA 45 BEACON ST, BOSTON, MA 02108-3693 SN 0027-0644 J9 MON WEATHER REV JI Mon. Weather Rev. PD JUN PY 1996 VL 124 IS 6 BP 1211 EP 1224 DI 10.1175/1520-0493(1996)124<1211:DVOTLT>2.0.CO;2 PG 14 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA UP593 UT WOS:A1996UP59300012 ER PT J AU Elder, KL Jones, GA Bolz, G AF Elder, KL Jones, GA Bolz, G TI Distribution of otoliths in surficial sediments of the US Atlantic continental shelf and slope and potential for reconstructing Holocene fish stocks SO PALEOCEANOGRAPHY LA English DT Article ID NORTHWEST ATLANTIC; MARINE; CLIMATOLOGY; RADIOCARBON; BOMB AB We examined more than 1100 surface sediment samples from the Atlantic continental margin of the United States to determine the feasibility of using fossil fish otoliths as diagnostic tools in reconstructing paleoenvironments and latitudinal distribution of fish stocks during the Holocene. Although 63% of the 1107 samples collected were from shelf areas (<140 m), the total number of shelf-derived otoliths represents only 0.3% of the entire sampled assemblage. The majority of of otoliths occurred on the continental slope (400-2000 m), with a maximum concentration in sediments at 500 to 600-m water depth. Otoliths of the most commonly occurring species, Ceratoscopelus maderensis, exhibit a marked distributional boundary just south of Cape Hatteras, North Carolina (33 degrees N), which mimics the distribution of their living counterparts. North of this boundary, C. maderensis constitutes greater than 70% of the preserved otolith assemblage, whereas more southerly regions contain no otoliths of this species. Although C. maderensis typically migrates diurnally over a depth of 300-600 m, otoliths taken from live-captured C. maderensis exhibit Delta(14)C values comparable to that of the dissolved inorganic carbon (DIC) of surface seawater in the study area. Accelerator mass spectrometry radiocarbon analyses of cooccurring otoliths and planktonic foraminifera from a sediment core collected south of Martha's Vineyard (40 degrees 15'N 70 degrees 51'W, 265 m) demonstrate temporal concordance throughout the Holocene. Otoliths appear to be viable, underutilized paleoceanographic tools. Specimens are found in sufficient abundance to permit temporal reconstructions of the distribution of C. maderensis and potentially several other icthyospecies along the U.S. Atlantic continental margin. C1 NATL MARINE FISHERIES SERV, WOODS HOLE, MA 02543 USA. TEXAS A&M UNIV, TEXAS INST OCEANOG, GALVESTON, TX 77553 USA. RP Elder, KL (reprint author), WOODS HOLE OCEANOG INST, WOODS HOLE, MA 02543 USA. NR 46 TC 4 Z9 4 U1 1 U2 2 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 0883-8305 EI 1944-9186 J9 PALEOCEANOGRAPHY JI Paleoceanography PD JUN PY 1996 VL 11 IS 3 BP 359 EP 367 DI 10.1029/96PA00042 PG 9 WC Geosciences, Multidisciplinary; Oceanography; Paleontology SC Geology; Oceanography; Paleontology GA VM328 UT WOS:A1996VM32800009 ER PT J AU Lynn, JW Huang, Q Sinha, SK Hossain, Z Gupta, LC Nagarajan, R Godard, C AF Lynn, JW Huang, Q Sinha, SK Hossain, Z Gupta, LC Nagarajan, R Godard, C TI Neutron scattering study of antiferromagnetic order in the magnetic superconductors RNi(2)B(2)C SO PHYSICA B-CONDENSED MATTER LA English DT Article; Proceedings Paper CT International Conference on Strongly Correlated Electron Systems (SCES 95) CY SEP 27-30, 1995 CL GOA, INDIA SP Tata Inst Fundamental Res, Bombay ID HONI2B2C AB Neutron diffraction has been used to investigate the magnetic order and crystallography of RNi(2)B(2)C. For R=Dy the magnetic order that develops at 10 K consists of ferromagnetic sheets of spins in the tetragonal a-b plane which are stacked antiferromagnetically along the c-axis. An identical magnetic order is observed for R = Ho at low T, while from similar to 5 K to T(N) approximate to 8 K each layer along the c-axis is rotated by 163 degrees to form a spiral state, which strongly couples the magnetic order to the superconductivity. Small a-axis peaks are also observed in a narrow temperature range, but the c-axis peaks are dominant. In ErNi(2)B(2)C (T(c)=11 K) an antiferromagnetic a-axis spin density wave state develops below T(N)=6.8 K, which readily coexists with the superconductivity indicating that weak coupling occurs between this type of magnetic state and the superconducting state. There is no evidence of magnetic order for either R=Ce or R=Y. C1 ARGONNE NATL LAB, ADV PHOTON SOURCE, ARGONNE, IL 60439 USA. TATA INST FUNDAMENTAL RES, BOMBAY 400005, MAHARASHTRA, INDIA. CNRS, UPR 209, F-92195 MEUDON, FRANCE. RP Lynn, JW (reprint author), NATL INST STAND & TECHNOL, DIV REACTOR RADIAT, GAITHERSBURG, MD 20899 USA. NR 17 TC 18 Z9 19 U1 0 U2 0 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0921-4526 J9 PHYSICA B JI Physica B PD JUN PY 1996 VL 223-24 IS 1-4 BP 66 EP 68 DI 10.1016/0921-4526(96)00040-3 PG 3 WC Physics, Condensed Matter SC Physics GA UX822 UT WOS:A1996UX82200016 ER PT J AU Orlandini, E Stella, AL Einstein, TL Tesi, MC Beichl, I Sullivan, F AF Orlandini, E Stella, AL Einstein, TL Tesi, MC Beichl, I Sullivan, F TI Bending-rigidity-driven transition and crumpling-point scaling of lattice vesicles SO PHYSICAL REVIEW E LA English DT Article ID SELF-AVOIDING SURFACES; PLANAR RANDOM SURFACES; STATISTICAL-MECHANICS; MONTE-CARLO; CRITICAL-BEHAVIOR; SQUARE LATTICE; MEMBRANES; CONFORMATION; POLYGONS AB The crumpling transition of three-dimensional (3D) lattice vesicles subject to a bending fugacity rho = exp(- kappa/k(B)T) is investigated by Monte Carlo methods in a grand canonical framework. By also exploiting conjectures suggested by previous rigorous results, a critical regime with scaling behavior in the universality class of branched polymers is found to exist for rho > rho(c). For rho < rho(c) the vesicles undergo a first-order transition that has remarkable similarities to the line of droplet singularities of inflated 2D vesicles. At the crumpling point (rho = rho(c)), which has a tricritical character, the average radius and the canonical partition function of vesicles with n plaquettes scale as n(nu c) and n-(theta c), respectively, with nu(c) = 0.4825 +/- 0.0015 and theta(c) = 1.78 +/- 0.03. These exponents indicate a new class, distinct from that of branched polymers, for scaling at the crumpling point. C1 IST NAZL FIS NUCL,DIPARTIMENTO FIS,I-35131 PADUA,ITALY. UNIV PADUA,SEZ INFN,I-35131 PADUA,ITALY. UNIV MARYLAND,DEPT PHYS,COLLEGE PK,MD 20742. UNIV OXFORD,INST MATH,OXFORD OX1 3LB,ENGLAND. NIST,COMP & APPL MATH LAB,GAITHERSBURG,MD 20899. CTR COMP SCI,BOWIE,MD 20715. RP Orlandini, E (reprint author), UNIV OXFORD,DEPT PHYS,OXFORD OX1 3NP,ENGLAND. OI Einstein, Theodore L./0000-0001-6031-4923 NR 37 TC 5 Z9 5 U1 0 U2 1 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 1063-651X J9 PHYS REV E JI Phys. Rev. E PD JUN PY 1996 VL 53 IS 6 BP 5800 EP 5807 DI 10.1103/PhysRevE.53.5800 PN A PG 8 WC Physics, Fluids & Plasmas; Physics, Mathematical SC Physics GA UR606 UT WOS:A1996UR60600038 ER PT J AU Garboczi, EJ Douglas, JF AF Garboczi, EJ Douglas, JF TI Intrinsic conductivity of objects having arbitrary shape and conductivity SO PHYSICAL REVIEW E LA English DT Article ID EFFECTIVE THERMAL-CONDUCTIVITY; INCLUSIONS; DIFFUSION; SPHERES; SHEET AB We study the electrical conductivity sigma of a dispersion of randomly oriented and positioned particle inclusions having common shape and conductivity sigma(p), suspended in an isotropic homogeneous matrix of conductivity sigma(0). For this problem, the mixture conductivity is a scalar and we concentrate on the leading order concentration virial coefficient, the ''intrinsic conductivity'' [sigma]. Results for [sigma] are summarized for limiting cases where there is a large mismatch between the conductivities of the inclusions and the suspending matrix. For a general particle shape, we then treat the more difficult case of arbitrary relative conductivity Delta=sigma(p)/sigma(0) through the introduction of a Pade approximant that incorporates (exact or numerical) information for [sigma(Delta)] in the Delta-->infinity,Delta-->0(+), and Delta approximate to 1 limits. Comparison of this approximation for [sigma(Delta)] to exact and finite element calculations for a variety of particle shapes in two and three dimensions shows excellent agreement over the entire range of Delta. This relation should be useful for inferring particle shape and property information from conductivity measurements on dilute particle dispersions. The leading order concentration virial coefficient for other mixture properties (thermal conductivity, dielectric constant, refractive index, shear modulus, bulk modulus, viscosity, etc.) are equally well described by a similar Pade approximant. RP Garboczi, EJ (reprint author), NATL INST STAND & TECHNOL,DIV POLYMERS,GAITHERSBURG,MD 20899, USA. NR 79 TC 74 Z9 76 U1 1 U2 9 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 1063-651X J9 PHYS REV E JI Phys. Rev. E PD JUN PY 1996 VL 53 IS 6 BP 6169 EP 6180 DI 10.1103/PhysRevE.53.6169 PN B PG 12 WC Physics, Fluids & Plasmas; Physics, Mathematical SC Physics GA UR607 UT WOS:A1996UR60700015 ER PT J AU Marx, E AF Marx, E TI Relativistic covariance and the interpretation of quantum mechanics SO PHYSICS ESSAYS LA English DT Article DE bound states; causality; conservation laws; Einstein-Podolsky-Rosen paradox; elementary particle physics; measurements; probability amplitudes; relativistic quantum mechanics; spinors; SWEEP model; wave function ID EQUATION-OF-MOTION; WAVE-EQUATION; BELL INEQUALITIES; CHARGED-PARTICLE; VIOLATION; POSITION; MOMENTUM; MODES AB The standard interpretation of quantum mechanics is raised to conform to the relativistic theory based on the many-amplitudes formalism for the many-particle system. The wave function has a character close to that of the electromagnetic field, with a secondary role for operators, the uncertainty principle, and the observer. There is no particle separate from the wave. The measurement process is interpreted as the quantum mechanical interaction between the system and the measuring apparatus. This approach leads to a different view of the double-slit experiment, the Einstein-Podolsky-Rosen paradox, and the thought experiment with Schrodinger's cat. Difficulties with spinor wavefunctions representing spin-1/2 particles are also addressed. It remains to be shown that many-amplitude nonrelativistic quantum mechanics agrees with experiment at least as well as the standard theory. The SWEEP model of strong, weak, and electromagnetic interactions of elementary particles is included here, because it allows for the use of relativistic quantum mechanics in all of elementary particle physics, thus extending the interpretation of wave functions. RP NATL INST STAND & TECHNOL, GAITHERSBURG, MD 20899 USA. NR 90 TC 1 Z9 1 U1 0 U2 2 PU PHYSICS ESSAYS PUBLICATION PI OTTAWA PA PO BOX 8141 STATION T, OTTAWA, ONTARIO K1G 3H6, CANADA SN 0836-1398 J9 PHYS ESSAYS JI Phys. Essays PD JUN PY 1996 VL 9 IS 2 BP 282 EP 301 PG 20 WC Physics, Multidisciplinary SC Physics GA VE037 UT WOS:A1996VE03700011 ER PT J AU Berg, RF Lyell, MJ McFadden, GB Rehm, RG AF Berg, RF Lyell, MJ McFadden, GB Rehm, RG TI Internal waves in xenon near the critical point SO PHYSICS OF FLUIDS LA English DT Article ID LIQUID CRITICAL-POINT; FLUIDS AB Just above the liquid-vapor critical point, a fluid's large compressibility causes a stable stratification in which the density varies by as much as 10% in 1 cm. This stratification supports internal gravity waves which we observed with an oscillator immersed in a near-critical xenon sample. We found the number and frequencies of the observable modes depended on the sample cell's orientation, with only two modes seen in the horizontal cell. The frequencies of the two modes had different temperature dependences: with decreasing temperature, the higher frequency increased monotonically from 0.7 to 2.8 Hz, but the lower frequency varied nonmonotonically, with a maximum of 1.0 Hz at 20 mK above the critical temperature. These temperature dependences continued to 20 mK below the critical temperature, where the xenon was separated into liquid and vapor phases. We calculated these two frequencies by solving the eigenvalue problem of internal waves in a box containing a stratified fluid. The fluid's density profile was obtained from xenon's equation of state. The calculated and measured frequencies agree to within 15%. Analytical calculations based on simple approximations of the density profile provide insight into the observed temperature dependences. (C) 1996 American Institute of Physics. C1 NIST,APPL & COMPUTAT MATH DIV,GAITHERSBURG,MD 20899. NIST,COMP & APPL MATH LAB,GAITHERSBURG,MD 20899. W VIRGINIA UNIV,DEPT MECH & AEROSP ENGN,MORGANTOWN,WV 26506. RP Berg, RF (reprint author), NIST,DIV THERMOPHYS,CHEM SCI & TECHNOL LAB,GAITHERSBURG,MD 20899, USA. RI McFadden, Geoffrey/A-7920-2008 OI McFadden, Geoffrey/0000-0001-6723-2103 NR 26 TC 12 Z9 12 U1 0 U2 1 PU AMER INST PHYSICS PI WOODBURY PA CIRCULATION FULFILLMENT DIV, 500 SUNNYSIDE BLVD, WOODBURY, NY 11797-2999 SN 1070-6631 J9 PHYS FLUIDS JI Phys. Fluids PD JUN PY 1996 VL 8 IS 6 BP 1464 EP 1475 DI 10.1063/1.868923 PG 12 WC Mechanics; Physics, Fluids & Plasmas SC Mechanics; Physics GA UM418 UT WOS:A1996UM41800017 ER PT J AU Goldsmith, JG Lazof, DB Linton, RW Gillen, G AF Goldsmith, JG Lazof, DB Linton, RW Gillen, G TI Imaging trace metals and mineral nutrient tracers in plant tissue by mass spectrometry SO PLANT PHYSIOLOGY LA English DT Meeting Abstract C1 UNIV S CAROLINA,DEPT CHEM,AIKEN,SC 29801. UNIV N CAROLINA,DEPT CHEM,CHAPEL HILL,NC 27599. NATL INST STAND & TECHNOL,GAITHERSBURG,MD 20899. NR 0 TC 0 Z9 0 U1 0 U2 1 PU AMER SOC PLANT PHYSIOLOGISTS PI ROCKVILLE PA 15501 MONONA DRIVE, ROCKVILLE, MD 20855 SN 0032-0889 J9 PLANT PHYSIOL JI Plant Physiol. PD JUN PY 1996 VL 111 IS 2 SU S BP 490 EP 490 PG 1 WC Plant Sciences SC Plant Sciences GA UR534 UT WOS:A1996UR53400530 ER PT J AU Lum, LSH Malghan, SG Schiller, SB AF Lum, LSH Malghan, SG Schiller, SB TI Standard reference materials for particle size analysis of ceramic powders by gravity sedimentation SO POWDER TECHNOLOGY LA English DT Article DE standard reference materials; fine size powders; particle size distribution; gravitational sedimentation method ID SILICON-NITRIDE AB Two standard reference materials (SRM), one a nitride powder and the other of an oxide powder, of mean size in the range of 1.0 mu m, were developed to assist in the measurement and analysis of fine size powders. SRM 659, a silicon nitride powder and SRM 1978, a zirconium oxide powder, are intended for calibration and evaluation of instruments used to measure particle size distribution using Sedigraph(R), a gravitational sedimentation method. In the development of these SRMs, the parameters of the powder deagglomeration procedures were studied to determine their effects on the measured particle size distribution of powders. The parameters studied included power output and time of sonication, initial pH of the suspension, and dispersant concentration. The morphology, density, surface area, and surface chemistry of these powders were also measured. C1 NIST,STAT ENGN DIV,TECHNOL ADM,DEPT COMMERCE,GAITHERSBURG,MD 20899. RP Lum, LSH (reprint author), NIST,DIV CERAM,TECHNOL ADM,DEPT COMMERCE,GAITHERSBURG,MD 20899, USA. NR 12 TC 7 Z9 7 U1 0 U2 1 PU ELSEVIER SCIENCE SA LAUSANNE PI LAUSANNE 1 PA PO BOX 564, 1001 LAUSANNE 1, SWITZERLAND SN 0032-5910 J9 POWDER TECHNOL JI Powder Technol. PD JUN PY 1996 VL 87 IS 3 BP 233 EP 238 DI 10.1016/0032-5910(96)03086-0 PG 6 WC Engineering, Chemical SC Engineering GA UT979 UT WOS:A1996UT97900005 ER PT J AU Band, A Stroscio, JA AF Band, A Stroscio, JA TI A closed loop controller for electron-beam evaporators SO REVIEW OF SCIENTIFIC INSTRUMENTS LA English DT Article AB A simple instrument for automatically controlling the deposition rate of an electron-beam evaporator is described. The design incorporates a commercially available, microprocessor based, proportional-integral-differential process controller that provides loop control and automatic determination of optimal proportional, integral, and differential loop constants. A logarithmic amplifier is used to linearize the overall loop response. The controller is used in conjunction with a compact electron-beam heated evaporator. C1 NIST,ELECTRON PHYS GRP,GAITHERSBURG,MD 20899. NR 5 TC 7 Z9 8 U1 2 U2 6 PU AMER INST PHYSICS PI WOODBURY PA CIRCULATION FULFILLMENT DIV, 500 SUNNYSIDE BLVD, WOODBURY, NY 11797-2999 SN 0034-6748 J9 REV SCI INSTRUM JI Rev. Sci. Instrum. PD JUN PY 1996 VL 67 IS 6 BP 2366 EP 2369 DI 10.1063/1.1147049 PG 4 WC Instruments & Instrumentation; Physics, Applied SC Instruments & Instrumentation; Physics GA UR222 UT WOS:A1996UR22200051 ER PT J AU Postek, MT AF Postek, MT TI An approach to the reduction of hydrocarbon contamination in the scanning electron microscope SO SCANNING LA English DT Article DE scanning electron microscope; transmission electron microscope; contamination; hydrocarbon; vacuum; pump; residual gas analysis ID STEEP; TIPS AB The deposition of electron beam-induced specimen contamination in both the transmission (TEM) and scanning electron microscopes (SEM) has remained a problem since the beginning of these forms of microscopy. Generally, sources of SEM contamination can be attributed to one or a combination of three major contributors: (1) the pumping system; (2) outgassing of other internal SEM component parts (i.e., specimen stage, stage lubricants, O-rings, etc.), or (3) the sample (including its preparation and handling). Generally, because of the nature of SEM, specimen contamination can be minimized but is difficult to avoid fully. This work outlines three approaches taken with instruments at NIST to reduce the deposition of contamination in high-resolution cold-field emission SEMs. With some modification these techniques could be applied to any SEM. These approaches have been in successful operation for several years, resulting in a reduction in electron beam-induced hydrocarbon contamination. RP Postek, MT (reprint author), NIST,TECHNOL A-347,GAITHERSBURG,MD 20899, USA. NR 15 TC 25 Z9 27 U1 3 U2 14 PU FAMS INC PI MAHWAH PA BOX 832, MAHWAH, NJ 07430 SN 0161-0457 J9 SCANNING JI Scanning PD JUN PY 1996 VL 18 IS 4 BP 269 EP 274 PG 6 WC Instruments & Instrumentation; Microscopy SC Instruments & Instrumentation; Microscopy GA UQ575 UT WOS:A1996UQ57500002 ER PT J AU Lowney, JR AF Lowney, JR TI Monte Carlo simulation of scanning electron microscope signals for lithographic metrology SO SCANNING LA English DT Article DE linewidth; lithography; metrology; Monte Carlo; scanning electron microscope AB Two computer codes for simulating the backscattered, transmitted, and secondary-electron signals from targets in a scanning electron microscope are described. The first code, MONSEL-II, has a model target consisting of three parallel lines on a three-layer substrate, while the second, MONSEL-III, has a model target consisting of a two-by-two array of finite lines on a three-layer substrate. Elastic electron scattering is determined by published fits to the Mott cross section. Both plasmon-generated electrons and ionized valence electrons are included in the secondary production. An adjustable quantity, called the residual energy loss rate, is added to the formula of Joy and Luo to obtain the measured secondary yield. The codes show the effects of signal enhancement due to edge transmission, known as blooming, as well as signal reduction due to neighboring lines, known as the ''black-hole'' effect. RP Lowney, JR (reprint author), NIST,DIV SEMICOND ELECTR,GAITHERSBURG,MD 20899, USA. NR 12 TC 27 Z9 27 U1 0 U2 2 PU FAMS INC PI MAHWAH PA BOX 832, MAHWAH, NJ 07430 SN 0161-0457 J9 SCANNING JI Scanning PD JUN PY 1996 VL 18 IS 4 BP 301 EP 306 PG 6 WC Instruments & Instrumentation; Microscopy SC Instruments & Instrumentation; Microscopy GA UQ575 UT WOS:A1996UQ57500006 ER PT J AU Zachariah, MR McMillin, BK AF Zachariah, MR McMillin, BK TI 2-D concentration maps by planar laser-induced fluorescent imaging SO SOLID STATE TECHNOLOGY LA English DT Article AB Model-based design is a particularly attractive tool, even for systems as physically and chemically complex as plasma reactors. In general, plasma models are limited by a lack of fundamental input data and accurate experimental benchmarks for assessing the quality of simulations, especially spatial distributions within the plasma. We demonstrate the application of an optical technique called planar laser-induced fluorescence for obtaining 2-D resolved-species concentration maps suitable for testing plasma models. Imaging has allowed the 2-D assessment of argon metastable and CF2 plasma densities under varied pressure, voltage, and radio-frequency (rf) power conditions. RP Zachariah, MR (reprint author), NATL INST STAND & TECHNOL,GAITHERSBURG,MD 20899, USA. NR 9 TC 0 Z9 0 U1 0 U2 0 PU PENNWELL PUBL CO SOLID STATE TECHNOLOGY OFFICE PI NASHUA PA TEN TARA BLVD 5TH FLOOR, NASHUA, NH 03062-2801 SN 0038-111X J9 SOLID STATE TECHNOL JI Solid State Technol. PD JUN PY 1996 VL 39 IS 6 BP 147 EP & PG 5 WC Engineering, Electrical & Electronic; Physics, Applied; Physics, Condensed Matter SC Engineering; Physics GA UQ578 UT WOS:A1996UQ57800028 ER PT J AU Walther, MM Eanes, ED Delaney, TF Travis, WD AF Walther, MM Eanes, ED Delaney, TF Travis, WD TI Bladder calcifications after photodynamic therapy: Analysis of a rare complication SO UROLOGY LA English DT Article ID TRANSITIONAL-CELL CARCINOMA; PHOTORADIATION THERAPY; CALCIUM-OXALATE; TUMORS; MICROCALCIFICATIONS; EXPERIENCE; DIAGNOSIS; CANCER; INSITU; BENIGN AB Objectives. We analyzed bladder calcifications occurring after photodynamic therapy administered for the treatment of superficial bladder cancer, a finding not previously reported after this treatment. Methods. Bladder biopsies from 20 patients undergoing photodynamic therapy were evaluated. Bladder calcifications were identified in 2 patients and analyzed for composition. Results. One patient had diffuse microcrystalline deposition in two biopsies composed of calcium oxalate monohydrate A. A second patient had a focal stone at a healing biopsy site composed of monoclinic calcium hydrogen phosphate dihydrate (brushite) (66%), calcium oxalate (25%), hydroxyapatite (6%), and protein (3%). Conclusions. Rare calcium oxalate and brushite calcifications were identified after photodynamic therapy and presumed to occur because of tissue injury associated with treatment. C1 NCI,NIH,RADIAT ONCOL BRANCH,PATHOL LAB,BETHESDA,MD 20898. NATL INST STAND & TECHNOL,GAITHERSBURG,MD 20899. RP Walther, MM (reprint author), NCI,NIH,SB,DCS,UROL ONCOL SECT,9000 ROCKVILLE PIKE,BLDG 10,ROOM 2B-43,10 CTR DR,BETHESDA,MD 20898, USA. NR 39 TC 6 Z9 7 U1 0 U2 0 PU CAHNERS PUBL CO PI NEW YORK PA 249 WEST 17 STREET, NEW YORK, NY 10011 SN 0090-4295 J9 UROLOGY JI UROLOGY PD JUN PY 1996 VL 47 IS 6 BP 831 EP 835 DI 10.1016/S0090-4295(96)00047-7 PG 5 WC Urology & Nephrology SC Urology & Nephrology GA UT256 UT WOS:A1996UT25600011 PM 8677572 ER PT J AU Montzka, SA Butler, JH Myers, RC Thompson, TM Swanson, TH Clarke, AD Lock, LT Elkins, JW AF Montzka, SA Butler, JH Myers, RC Thompson, TM Swanson, TH Clarke, AD Lock, LT Elkins, JW TI Decline in the tropospheric abundance of halogen from halocarbons: Implications for stratospheric ozone depletion SO SCIENCE LA English DT Article ID HYDROGEN-CHLORIDE; ANTARCTIC OZONE; GROWTH-RATES; ATMOSPHERE; AIR; DESTRUCTION; RADICALS; LATITUDE; DECREASE; HCFC-22 AB Analyses of air sampled from remote locations across the globe reveal that tropospheric chlorine attributable to anthropogenic halocarbons peaked near the beginning of 1994 and was decreasing at a rate of 25 +/- 5 parts per trillion per year by mid-1995. Although bromine from halons was still increasing in mid-1995, the summed abundance of these halogens in the troposphere is decreasing. To assess the effect of this trend on stratospheric ozone, estimates of the future stratospheric abundance of ozone-depleting gases were made for mid-latitude and polar regions on the basis of these tropospheric measurements. These results suggest that the amount of reactive chlorine and bromine will reach a maximum in the stratosphere between 1997 and 1999 and will decline thereafter if limits outlined in the adjusted and amended Montreal Protocol on Substances That Deplete the Ozone Layer are not exceeded in future years. C1 UNIV COLORADO,COOPERAT INST RES ENVIRONM SCI,BOULDER,CO 80309. RP Montzka, SA (reprint author), NOAA,CLIMATE MONITORING & DIAGNOST LAB,BOULDER,CO 80303, USA. OI Montzka, Stephen/0000-0002-9396-0400 NR 61 TC 239 Z9 244 U1 3 U2 29 PU AMER ASSOC ADVANCEMENT SCIENCE PI WASHINGTON PA 1200 NEW YORK AVE, NW, WASHINGTON, DC 20005 SN 0036-8075 J9 SCIENCE JI Science PD MAY 31 PY 1996 VL 272 IS 5266 BP 1318 EP 1322 DI 10.1126/science.272.5266.1318 PG 5 WC Multidisciplinary Sciences SC Science & Technology - Other Topics GA UN472 UT WOS:A1996UN47200040 ER PT J AU Kirschenbaum, LS Rogers, CT Beale, PD Russek, SE Sanders, SC AF Kirschenbaum, LS Rogers, CT Beale, PD Russek, SE Sanders, SC TI Bias current dependent resistance peaks in NiFe/Ag giant magnetoresistance multilayers SO APPLIED PHYSICS LETTERS LA English DT Article AB We show that thin-film Ni82Fe18/Ag multilayer structures display multiple peaks in their magnetoresistance curves when biased at current densities above 10(6) A/cm(2). These peaks appear for annealed and unannealed structures, and their number is correlated with the number of NiFe layers. At high bias currents, the peak positions shift linearly with the internal magnetic field created by the bias current. The peak positions extrapolate to nonzero fields at zero bias currents, providing an upper bound on the magnetic layer-layer coupling strength of J(0) approximate to 10(-20) J (k(B)x700 K). The peak positions do not shift with temperature over the range 200-375 K; their widths narrow with increasing temperature. The single-domain magnetic moment mu is estimated as 10(-17) J/T (10(6) mu(B)) from the peak widths of similar to 0.8 kA/m. (C) 1996 American Institute of Physics. C1 NATL INST STAND & TECHNOL,BOULDER,CO 80303. RP Kirschenbaum, LS (reprint author), UNIV COLORADO,DEPT PHYS,CONDENSED MATTER LAB,BOULDER,CO 80309, USA. NR 9 TC 2 Z9 2 U1 2 U2 2 PU AMER INST PHYSICS PI WOODBURY PA CIRCULATION FULFILLMENT DIV, 500 SUNNYSIDE BLVD, WOODBURY, NY 11797-2999 SN 0003-6951 J9 APPL PHYS LETT JI Appl. Phys. Lett. PD MAY 27 PY 1996 VL 68 IS 22 BP 3099 EP 3101 DI 10.1063/1.116435 PG 3 WC Physics, Applied SC Physics GA UM643 UT WOS:A1996UM64300013 ER PT J AU Benz, SP Hamilton, CA AF Benz, SP Hamilton, CA TI A pulse-driven programmable Josephson voltage standard SO APPLIED PHYSICS LETTERS LA English DT Article ID JUNCTIONS AB A voltage standard based on a series array of pulse-biased, nonhysteretic Josephson junctions is proposed. The output voltage can be rapidly and continuously programmed over a wide range by changing the pulse repetition frequency. Simulations relate the circuit margins to pulse height, width, and frequency. Experimental results on a prototype circuit confirm the expected behavior. RP Benz, SP (reprint author), NATL INST STAND & TECHNOL,325 BROADWAY,BOULDER,CO 80303, USA. NR 10 TC 160 Z9 162 U1 1 U2 10 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 MAY 27 PY 1996 VL 68 IS 22 BP 3171 EP 3173 DI 10.1063/1.115814 PG 3 WC Physics, Applied SC Physics GA UM643 UT WOS:A1996UM64300037 ER PT J AU Cess, RD Zhang, MH Ingram, WJ Potter, GL Alskseev, V Barker, HW Cohen-Solal, E Colman, RA Dazlich, DA Del Genio, AD Dix, MR Dymnikov, V Esch, M Fowler, LD Fraser, JR Galin, V Gates, WL Hack, JJ Kiehl, JT Le Treut, H Lo, KKW McAvaney, BJ Meleshko, VP Morcrette, JJ Randall, DA Roeckner, E Royer, JF Schlesinger, ME Sporyshev, PV Timbal, B Volodin, EM Taylor, KE Wang, W Wetherald, RT AF Cess, RD Zhang, MH Ingram, WJ Potter, GL Alskseev, V Barker, HW Cohen-Solal, E Colman, RA Dazlich, DA Del Genio, AD Dix, MR Dymnikov, V Esch, M Fowler, LD Fraser, JR Galin, V Gates, WL Hack, JJ Kiehl, JT Le Treut, H Lo, KKW McAvaney, BJ Meleshko, VP Morcrette, JJ Randall, DA Roeckner, E Royer, JF Schlesinger, ME Sporyshev, PV Timbal, B Volodin, EM Taylor, KE Wang, W Wetherald, RT TI Cloud feedback in atmospheric general circulation models: An update SO JOURNAL OF GEOPHYSICAL RESEARCH-ATMOSPHERES LA English DT Article ID RADIATION BUDGET EXPERIMENT; CLIMATE FEEDBACK AB Six years ago, we compared the climate sensitivity of 19 atmospheric general circulation models and found a roughly threefold variation among the models; most of this variation was attributed to differences in the models' depictions of cloud feedback. In an update of this comparison, current models showed considerably smaller differences in net cloud feedback, with most producing modest values. There are, however, substantial differences in the feedback components, indicating that the models still have physical disagreements. C1 SUNY STONY BROOK, MARINE SCI RES CTR, INST TERR & PLANETARY ATMOSPHERES, STONY BROOK, NY 11794 USA. RUSSIAN ACAD SCI, DEPT NUMER MATH, MOSCOW 117334, RUSSIA. CANADIAN CLIMATE CTR, DOWNSVIEW, ON M3H 5T4, CANADA. METEOROL DYNAM LAB, F-75231 PARIS 05, FRANCE. BUR METEOROL, RES CTR, MELBOURNE, VIC 3001, AUSTRALIA. COLORADO STATE UNIV, FT COLLINS, CO 80523 USA. NASA, GODDARD INST SPACE STUDIES, NEW YORK, NY 10025 USA. CSIRO, DIV ATMOSPHER RES, MORDIALLOC, VIC 3195, AUSTRALIA. MAX PLANCK INST METEOROL, D-20146 HAMBURG, GERMANY. LAWRENCE LIVERMORE NATL LAB, PROGRAM CLIMATE MODEL DIAGNOSIS & INTERCOMPARISON, LIVERMORE, CA 94550 USA. NATL CTR ATMOSPHER RES, BOULDER, CO 80307 USA. METEOROL OFF, HADLEY CTR CLIMATE PREDICT & RES, BRACKNELL RG12 2SY, BERKS, ENGLAND. METEO FRANCE, CTR NATL RECH METEOROL, F-31057 TOULOUSE, FRANCE. VOEIKOV MAIN GEOPHYS OBSERV, ST PETERSBURG 194018, RUSSIA. EUROPEAN CTR MEDIUM RANGE WEATHER FORECASTS, READING RG2 9AX, BERKS, ENGLAND. UNIV ILLINOIS, DEPT ATMOSPHER SCI, URBANA, IL 61801 USA. PRINCETON UNIV, NOAA, GEOPHYS FLUID DYNAM LAB, PRINCETON, NJ 08540 USA. RI alexeev, vladimir/B-2234-2010; Taylor, Karl/F-7290-2011; Del Genio, Anthony/D-4663-2012; Dix, Martin/A-2334-2012; Meleshko, Valentin/D-2157-2016; Randall, David/E-6113-2011; Sporyshev, Petr/P-7323-2015 OI alexeev, vladimir/0000-0003-3519-2797; Taylor, Karl/0000-0002-6491-2135; Del Genio, Anthony/0000-0001-7450-1359; Dix, Martin/0000-0002-7534-0654; Randall, David/0000-0001-6935-4112; Sporyshev, Petr/0000-0002-4047-8178 NR 8 TC 216 Z9 223 U1 3 U2 24 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 27 PY 1996 VL 101 IS D8 BP 12791 EP 12794 DI 10.1029/96JD00822 PG 4 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA UN379 UT WOS:A1996UN37900001 ER PT J AU Newman, PA Lait, LR Schoeberl, MR Seablom, M Coy, L Rood, R Swinbank, R Proffitt, M Loewenstien, M Podolske, JR Elkins, JW Webster, CR May, RD Fahey, DW Dutton, GS Chan, KR AF Newman, PA Lait, LR Schoeberl, MR Seablom, M Coy, L Rood, R Swinbank, R Proffitt, M Loewenstien, M Podolske, JR Elkins, JW Webster, CR May, RD Fahey, DW Dutton, GS Chan, KR TI Measurements of polar vortex air in the midlatitudes SO JOURNAL OF GEOPHYSICAL RESEARCH-ATMOSPHERES LA English DT Article ID STRATOSPHERE; MODEL; WAVES; TEMPERATURES; BREAKING AB The Stratospheric Photochemistry, Aerosols, and Dynamics Expedition (SPADE) was conducted in the spring of 1993 from Moffett Field, California (NASA Ames Research Center), utilizing the NASA high-altitude ER-2 aircraft. These northern midlatitude aircraft flights showed laminae containing high ozone concentrations, traceable to the April 1993 polar vortex breakup and corroborated by laminae of other trace gases such as CFCs, CH4, N2O, and CO2. These laminae are clearly traceable as polar vortex breakup fragments using Rossby-Ertel's potential vorticity and isentropic trajectory calculations. Laminae in stratospheric ozone pro-files are commonly observed in the northern hemisphere from fall to spring, and are hypothesized to originate from very low frequency transverse waves, and/or via Rossby wave breaking. On the basis of these results, the ozone laminae observed during SPADE were a result of Rossby wave breaking during the breakdown of the polar vortex. In addition, it is shown that conventional once-per-day meteorological analyses were adequate for representing the transport of this material into the lower stratosphere midlatitudes over the course of the spring vortex breakup. C1 NASA, AMES RES CTR, MOFFETT FIELD, CA 94035 USA. NOAA, CLIMATE MONITORING & DIAGNOST LAB, BOULDER, CO 80303 USA. NOAA, AERON LAB, BOULDER, CO 80303 USA. CALTECH, JET PROP LAB, PASADENA, CA 91109 USA. TASC INC, RESTON, VA 22090 USA. METEOROL OFF, BRACKNELL RG12 2SZ, BERKS, ENGLAND. RP Newman, PA (reprint author), NASA, GODDARD SPACE FLIGHT CTR, CODE 916, GREENBELT, MD 20771 USA. RI Newman, Paul/D-6208-2012; Rood, Richard/C-5611-2008; Fahey, David/G-4499-2013 OI Newman, Paul/0000-0003-1139-2508; Rood, Richard/0000-0002-2310-4262; Fahey, David/0000-0003-1720-0634 NR 65 TC 46 Z9 46 U1 0 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 27 PY 1996 VL 101 IS D8 BP 12879 EP 12891 DI 10.1029/95JD03387 PG 13 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA UN379 UT WOS:A1996UN37900010 ER PT J AU Gierczak, T Talukdar, RK Burkholder, JB Portmann, RW Daniel, JS Solomon, S Ravishankara, AR AF Gierczak, T Talukdar, RK Burkholder, JB Portmann, RW Daniel, JS Solomon, S Ravishankara, AR TI Atmospheric fate and greenhouse warming potentials of HFC 236fa and HFC 236ea SO JOURNAL OF GEOPHYSICAL RESEARCH-ATMOSPHERES LA English DT Article ID UNIMOLECULAR ELIMINATION; HYDROFLUOROCARBONS; LIFETIMES; OH AB The rate coefficient for the reaction OH + CF3CH2CF3 (1,1,1,3,3,3-hexafluoropropane, HFC236fa) was measured between 269 and 413 K using the pulsed photolysis-laser: induced fluorescence technique to be k(1) = (1.60 +/- 0.40) x 10(-12) exp (-(2450 +/- 150)/T) cm(3) molecule(-1) s(-1). The rate Coefficient, k(2b), for the destruction of CF3CH2CF3 via reaction with O(D-1) was measured to be (4.5 +/- 1.9) x 10(-12) cm(3) molecule(-1) s(-1) using the laser photolysis-resonance fluorescence technique. From these data, along with previously published rate coefficients for OH reaction with HFC236ea, the atmospheric lifetimes of HFC238fa and HFC236ea were calculated to be 210 and 8.1 years, respectively. The room temperature infrared absorption cross sections for these two compounds were measured over the range 650 to 1350 cm(-1) The global warming potentials (GWPs) of HFC236fa and HFC236ea, respectively, were calculated to be 5610 and 2200 for a 20-year horizon and 5160 and 220 for a 500-year horizon. C1 NOAA, ERL, AERON LAB, BOULDER, CO 80303 USA. UNIV COLORADO, COOPERAT INST RES ENVIRONM SCI, BOULDER, CO 80309 USA. UNIV COLORADO, DEPT CHEM & BIOCHEM, BOULDER, CO 80309 USA. RI Portmann, Robert/C-4903-2009; Daniel, John/D-9324-2011; TALUKDAR, RANAJIT/G-4530-2013; Burkholder, James/H-4914-2013; Ravishankara, Akkihebbal/A-2914-2011 OI Portmann, Robert/0000-0002-0279-6087; TALUKDAR, RANAJIT/0000-0001-6017-8431; NR 27 TC 5 Z9 5 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 27 PY 1996 VL 101 IS D8 BP 12905 EP 12911 DI 10.1029/96JD00059 PG 7 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA UN379 UT WOS:A1996UN37900012 ER PT J AU Davies, A Stroscio, JA Pierce, DT Celotta, RJ AF Davies, A Stroscio, JA Pierce, DT Celotta, RJ TI Atomic-scale observations of alloying at the Cr-Fe(001) interface SO PHYSICAL REVIEW LETTERS LA English DT Article ID CR THIN-FILMS; FE(100); MOMENTS; GROWTH; IRON AB While much progress has been made using epitaxial growth of Fe/Cr/Fe structures to study magnetic exchange coupling, a number of anomalies have arisen in studies of this model system. Using scanning tunneling microscopy and spectroscopy to investigate Cr growth on Fe(001), we have identified a potential structural cause of these anomalies. We show that Cr growth under layer-by-layer conditions on Fe(001) leads to the formation of a Cr-Fe alloy. We exploit a Cr and Fe surface state to identify single Cr impurities in Fe and evaluate the alloy concentrations with increasing Cr coverage. RP Davies, A (reprint author), NATL INST STAND & TECHNOL, ELECTRON PHYS GRP, GAITHERSBURG, MD 20899 USA. NR 22 TC 195 Z9 196 U1 1 U2 10 PU AMER PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 0031-9007 J9 PHYS REV LETT JI Phys. Rev. Lett. PD MAY 27 PY 1996 VL 76 IS 22 BP 4175 EP 4178 DI 10.1103/PhysRevLett.76.4175 PG 4 WC Physics, Multidisciplinary SC Physics GA UM245 UT WOS:A1996UM24500019 ER PT J AU Gadzuk, JW AF Gadzuk, JW TI Resonance-assisted hot electron femtochemistry at surfaces SO PHYSICAL REVIEW LETTERS LA English DT Article ID INELASTIC-SCATTERING; DESORPTION; SPECTROSCOPY; MOLECULES; EMISSION AB A theory of resonance-assisted, hot-electron-induced femtochemical processing at surfaces (HEFATS) has been developed in terms of inelastic electron scattering via negative-molecular-ion shape resonances associated with molecules adsorbed on solid surfaces. Two examples, one involving a broad band of laser-excited hot electrons and the other a tunable narrow band produced by a solid state tunnel junction, are used to illustrate the potential of HEFATS in chemical bond breaking as, for instance, in desorption. RP Gadzuk, JW (reprint author), NATL INST STAND & TECHNOL,GAITHERSBURG,MD 20899, USA. NR 31 TC 64 Z9 64 U1 0 U2 8 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 27 PY 1996 VL 76 IS 22 BP 4234 EP 4237 DI 10.1103/PhysRevLett.76.4234 PG 4 WC Physics, Multidisciplinary SC Physics GA UM245 UT WOS:A1996UM24500034 ER PT J AU Monroe, C Meekhof, DM King, BE Wineland, DJ AF Monroe, C Meekhof, DM King, BE Wineland, DJ TI A ''Schrodinger cat'' superposition state of an atom SO SCIENCE LA English DT Article ID JAYNES-CUMMINGS MODEL; QUANTUM COHERENCE; INTERFEROMETER; DISPERSION; GENERATION; COLLAPSE; REVIVAL AB A ''Schrodinger cat''-like state of matter was generated at the single atom level. A trapped Be-9(+) ion was laser-cooled to the zero-point energy and then prepared ina superposition of spatially separated coherent harmonic oscillator states. This state was created by application of a sequence of laser pulses, which entangles internal (electronic) and external (motional) states of the ion. The Schrodinger cat superposition was verified by detection of the quantum mechanical interference between the localized wave packets. This mesoscopic system may provide insight into the fuzzy boundary between the classical and quantum worlds by allowing controlled studies of quantum measurement and quantum decoherence. RP Monroe, C (reprint author), NATL INST STAND & TECHNOL,DIV TIME & FREQUENCY,MS 847,BOULDER,CO 80303, USA. RI Monroe, Christopher/G-8105-2011 NR 51 TC 914 Z9 927 U1 16 U2 83 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 24 PY 1996 VL 272 IS 5265 BP 1131 EP 1136 DI 10.1126/science.272.5265.1131 PG 8 WC Multidisciplinary Sciences SC Science & Technology - Other Topics GA UM889 UT WOS:A1996UM88900039 ER PT J AU Poirier, GE Pylant, ED AF Poirier, GE Pylant, ED TI The self-assembly mechanism of alkanethiols on Au(111) SO SCIENCE LA English DT Article ID SCANNING TUNNELING MICROSCOPY; N-ALKANETHIOLS; MONOLAYERS; GOLD; SURFACE; SPECTROSCOPY; ADSORPTION; THIOLS AB The self-assembly mechanism of alkanethiol monolayers on the (111) surface of gold was discovered with the use of an ultrahigh-vacuum scanning tunneling microscope. Monolayer formation follows a two-step process that begins with condensation of low-density crystalline islands, characterized by surface-aligned molecular axes, from a lower density lattice-gas phase. At saturation coverage of this phase, the monolayer undergoes a phase transition to a denser phase by realignment of the molecular axes with the surface normal. These studies reveal the important role of molecule-substrate and molecule-molecule interactions in the self-assembly of these technologically important material systems. C1 UNIV TEXAS,DEPT CHEM & BIOCHEM,AUSTIN,TX 78712. NATL INST STAND & TECHNOL,GAITHERSBURG,MD 20899. NR 28 TC 665 Z9 670 U1 9 U2 132 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 24 PY 1996 VL 272 IS 5265 BP 1145 EP 1148 DI 10.1126/science.272.5265.1145 PG 4 WC Multidisciplinary Sciences SC Science & Technology - Other Topics GA UM889 UT WOS:A1996UM88900041 ER PT J AU Zachariah, MR Westmoreland, PR Burgess, DR Tsang, W AF Zachariah, MR Westmoreland, PR Burgess, DR Tsang, W TI BAC-MP4 predictions of thermochemical data for C-1 and C-2 stable and radical hydrofluorocarbons and oxidized hydrofluorocarbons SO JOURNAL OF PHYSICAL CHEMISTRY LA English DT Article ID BOND-DISSOCIATION ENERGIES; VIBRATIONAL FREQUENCIES; THERMODYNAMIC FUNCTIONS; ATMOSPHERIC CHEMISTRY; ABINITIO; COMBUSTION; BARRIERS; ROTATION; HEAT AB An ab initio bond additivity corrected quantum chemistry procedure has been applied to the development of a data base for thermochemistry of C/H/F/O species. This information has been used to construct a chemical kinetic mechanism for the prediction of the behavior of fluorocarbons as flame suppressants, with clear applications to plasma and atmospheric chemistry as well. Bond additivity corrected (BAC) Moller-Plesset fourth-order perturbation theory (MP4) calculations have been performed to obtain a large body of thermochemical data on about 100 closed and open shelled fluorocarbon species, For about 70 of these species, literature values for enthalpies of formation were available for comparison to the calculated values. The average difference between the calculated and literature values was about 9 kJ/mol. The results indicate that the BAC-MP4 procedure can provide energies that are comparable in accuracy to most experimentally derived values, at lower computational costs relative to other more computationally expensive nb Initio molecular orbital methods, This work provides a substantial data base of thermochemical data for fluorinated hydrocarbons constructed in a self-consistent manner. C1 UNIV MASSACHUSETTS,AMHERST,MA 01003. SANDIA NATL LABS,LIVERMORE,CA. RP Zachariah, MR (reprint author), NATL INST STAND & TECHNOL,GAITHERSBURG,MD 20899, USA. NR 45 TC 119 Z9 123 U1 1 U2 7 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 SN 0022-3654 J9 J PHYS CHEM-US JI J. Phys. Chem. PD MAY 23 PY 1996 VL 100 IS 21 BP 8737 EP 8747 DI 10.1021/jp952467f PG 11 WC Chemistry, Physical SC Chemistry GA UM677 UT WOS:A1996UM67700018 ER PT J AU Orkin, VL Huie, RE Kurylo, MJ AF Orkin, VL Huie, RE Kurylo, MJ TI Atmospheric lifetimes of HFC-143a and HFC-245fa: Flash photolysis resonance fluorescence measurements of the OH reaction rate constants SO JOURNAL OF PHYSICAL CHEMISTRY LA English DT Article ID HYDROXYL RADICALS; KINETICS; HYDROCHLOROFLUOROCARBONS AB Rate constants for the reactions of hydroxyl radicals with CH3CF3 (HFC-143a) and CHF2CH2CF3 (HFC-245fa) have been measured using the flash photolysis resonance fluorescence technique over the temperature range 273-370 K. A data analysis procedure is presented which should minimize rate constant errors introduced by the possible effects of radical diffusion. The following Arrhenius expressions have been derived for the reactions of OH with CH3CF3 and CHF2CH2CF3, respectively (in units of cm(3) molecule(-1) s(-1)): (0.95(-0.17)(+0.21)) x 10(-12) exp{-1979 +/- 65)/T} and (0.632(-0.078)(+0.089)) x 10(-12) exp{-1331 +/- 43)/T}. With these values, the atmospheric lifetimes for the two HFCs have been estimated to be 51 and 7.4 years, respectively. An error analysis is presented from which the rate constant uncertainty at any temperature can be calculated. RP Orkin, VL (reprint author), NIST,DIV CHEM KINET & THERMODYNAM,CHEM SCI & TECHNOL LAB,GAITHERSBURG,MD 20899, USA. RI Huie, Robert/A-5645-2010; Kurylo, Michael/H-2201-2012 NR 23 TC 39 Z9 39 U1 1 U2 2 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 SN 0022-3654 J9 J PHYS CHEM-US JI J. Phys. Chem. PD MAY 23 PY 1996 VL 100 IS 21 BP 8907 EP 8912 DI 10.1021/jp9601882 PG 6 WC Chemistry, Physical SC Chemistry GA UM677 UT WOS:A1996UM67700043 ER PT J AU Woicik, JC Miyano, KE Pellegrino, JG Shaw, PS Southworth, SH Karlin, BA AF Woicik, JC Miyano, KE Pellegrino, JG Shaw, PS Southworth, SH Karlin, BA TI Strain and relaxation in InAs and InGaAs films grown on GaAs(001) SO APPLIED PHYSICS LETTERS LA English DT Article ID ABSORPTION FINE-STRUCTURE; EPITAXIAL LAYERS AB The strain and relaxation of InAs and InGaAs films grown on GaAs(001) have been examined by the x-ray standing wave and extended x-ray absorption fine-structure techniques. While 1 monolayer (ML) films of both InAs and InGaAs are found to be tetragonally distorted in accordance with the prediction of macroscopic-elastic theory, thicker InAs films are found to collapse to their natural-lattice constant past a critical thickness T-c, of similar to 2 ML's. By 8 ML's, bond-length strain is no longer evident, and a large degree of structural disorder is observed. (C) 1996 American Institute of Physics. C1 CUNY BROOKLYN COLL,DEPT PHYS,BROOKLYN,NY 11210. RP Woicik, JC (reprint author), NATL INST STAND & TECHNOL,GAINESVILLE,MD 20899, USA. NR 17 TC 20 Z9 20 U1 1 U2 7 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 MAY 20 PY 1996 VL 68 IS 21 BP 3010 EP 3012 DI 10.1063/1.116680 PG 3 WC Physics, Applied SC Physics GA UL632 UT WOS:A1996UL63200032 ER PT J AU Muller, R Crutzen, PJ Grooss, JU Bruhl, C Russell, JM Tuck, AF AF Muller, R Crutzen, PJ Grooss, JU Bruhl, C Russell, JM Tuck, AF TI Chlorine activation and ozone depletion in the Arctic vortex: Observations by the Halogen Occultation Experiment on the Upper Atmosphere Research Satellite SO JOURNAL OF GEOPHYSICAL RESEARCH-ATMOSPHERES LA English DT Article ID ANTARCTIC OZONE; POLAR VORTEX; AIRCRAFT MEASUREMENTS; LOWER STRATOSPHERE; WINTER; CHEMISTRY; SPECTROSCOPY; AEROSOL; TRENDS; ICE AB Chlorine-catalyzed ozone destruction is clearly observed during austral spring in the Antarctic lower stratosphere. While high concentrations of ozone-destroying ClO radicals have likewise been measured during winter in the Arctic stratosphere, the chemical ozone depletion there is more difficult to quantify. Here we present observations of the Halogen Occultation Experiment on the Upper Atmosphere Research Satellite in the vortex region of the Arctic lower stratosphere during the winter and spring months of 1991/1992, 1992/1993, 1993/1994, and 1994/1995. All February measurements indicate an almost complete conversion of the otherwise main chlorine reservoir species HCl to chemically more reactive forms. Using CH4 as a chemically conserved tracer, we show that significant chemical ozone loss occurred in the Arctic vortex region during all four winters. The deficit in column ozone was about 60 and 50 Dobson units (DU) in the winters 1991/1992 and 1993/1994, respectively. During the two winters of 1992/1993 and 1994/1995 a severe chemical loss in lower-stratospheric ozone took place, with local reductions of the mixing ratios by over 50% and a loss in the column ozone of the order of 100 DU. C1 NASA, LANGLEY RES CTR, HAMPTON, VA 23665 USA. NOAA, AERON LAB, BOULDER, CO 80303 USA. MAX PLANCK INST CHEM, DEPT ATMOSPHER CHEM, D-55020 MAINZ, GERMANY. RI GrooSS, Jens-Uwe/A-7315-2013; Tuck, Adrian/F-6024-2011; Crutzen, Paul/F-6044-2012; Muller, Rolf/A-6669-2013 OI GrooSS, Jens-Uwe/0000-0002-9485-866X; Tuck, Adrian/0000-0002-2074-0538; Muller, Rolf/0000-0002-5024-9977 NR 79 TC 86 Z9 87 U1 0 U2 7 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 2169-897X J9 J GEOPHYS RES-ATMOS JI J. Geophys. Res.-Atmos. PD MAY 20 PY 1996 VL 101 IS D7 BP 12531 EP 12554 PG 24 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA UN558 UT WOS:A1996UN55800005 ER PT J AU Beine, HJ Jaffe, DA Blake, DR Atlas, E Harris, J AF Beine, HJ Jaffe, DA Blake, DR Atlas, E Harris, J TI Measurements of PAN, alkyl nitrates, ozone, and hydrocarbons during spring in interior Alaska SO JOURNAL OF GEOPHYSICAL RESEARCH-ATMOSPHERES LA English DT Article ID ORGANIC NITRATES; NITROGEN-OXIDES; ARCTIC TROPOSPHERE; REACTIVE NITROGEN; POLLUTION; CHEMISTRY; AEROSOLS; BARROW; GASES; SITE AB Measurements of the atmospheric mixing ratios of ozone, peroxyacetylniltrate (PAN), hydrocarbons, and alkyl nitrates were made in a boreal forest ecosystem in the interior of Alaska from March 15 to May 14, 1993. During this period the mixing ratios of PAN, alkyl nitrates, and nonmethane hydrocarbons (NMHCs) generally decreased due to the influence of both meteorology and OH removal. Mean mixing ratios of ozone, PAN, C-2-C-6 alkyl nitrates, and total C-2-C-5 NMHC during southerly flow periods were 24.4 parts per billion (ppbv), 132.1 parts per trillion (pptv), 34 pptv, and 8.2 ppbCv, respectively. During a short period of northerly flow, mixing ratios of PAN and total NMHC were approxinately 2 times the southerly flow mixing ratios. PAN is correlated with ozone, and alkyl nitrates are correlated with alkanes. PAN and ozone mixing ratios exhibit similar diurnal variations on a number of days with an early morning minimum and afternoon maximum. This is likely due to a diurnal cycle in the boundary layer-free troposphere exchange and loss processes in the boundary layer for both O-3 and PAN. Higher molecular weight (mw) hydrocarbons and alkyl nitrates are observed to decrease more quickly than the lower mw hydrocarbons consistent with removal by OH as the primary loss process. C1 UNIV ALASKA, DEPT CHEM, FAIRBANKS, AK 99775 USA. NCAR, BOULDER, CO 80303 USA. UNIV CALIF IRVINE, DEPT CHEM, IRVINE, CA 92717 USA. NOAA, CLIMATE MONITORING & DIAGNOST LAB, BOULDER, CO 80303 USA. RP Beine, HJ (reprint author), UNIV ALASKA, INST GEOPHYS, 903 N KOYUKUK DR, FAIRBANKS, AK 99775 USA. RI Atlas, Elliot/J-8171-2015 NR 32 TC 32 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 20 PY 1996 VL 101 IS D7 BP 12613 EP 12619 DI 10.1029/96JD00342 PG 7 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA UN558 UT WOS:A1996UN55800011 ER PT J AU Moxim, WJ Levy, H Kasibhatla, PS AF Moxim, WJ Levy, H Kasibhatla, PS TI Simulated global tropospheric PAN: Its transport and impact on NOx SO JOURNAL OF GEOPHYSICAL RESEARCH-ATMOSPHERES LA English DT Article ID OBSERVATORY PHOTOCHEMISTRY EXPERIMENT; PEROXYACETYL NITRATE; OZONE PRODUCTION; NITROGEN-OXIDES; SEASONAL-VARIATION; MODEL; ATMOSPHERE; PACIFIC; CIRCULATION; EMISSIONS AB Using the 11-level Geophysical Fluid Dynamics Laboratory (GFDL) global chemical transport model (GCTM) with all known sources of tropospheric NOx, we simulate the global tropospheric distribution of peroxyacetyl nitrate (PAN) and quantify its impact on tropospheric NOx. The model's global distribution of PAN is in reasonable agreement with most available observations. In the atmospheric boundary layer, PAN is concentrated over the continental sites of NOx emissions, primarily the midlatitudes in the northern hemisphere and the subtropics in the southern hemisphere. PAN is distributed relatively zonally throughout the free troposphere of the northern hemisphere, with the maximum levels found in the coldest regions, while in the southern hemisphere the maximum PAN levels are found in an equator to 30 degrees S belt stretching from South America to Australia. Overall, the simulated three-dimensional fields of seasonal PAN are a result of the interaction: of the type of transport meteorology (convective or synoptic scale storms) occurring in the PAN formation regions and PAN's temperature-dependent lifetime. We find the impact of PAN chemistry on NOx to be rather subtle. The magnitude and the seasonal cycle of the global tropospheric integral of NOx, which has its maximum in January and the formation of HNO3 as its dominant loss path, are barely affected by the inclusion of PAN chemistry, however PAN, as a result of its temperature sensitivity and transport, regionally provides an efficient mechanism for redistributing NOx far from its source areas. With the inclusion of PAN chemistry, monthly mean NOx concentrations increase by up to a factor of 5 in the remote lower troposphere and show a spring maximum over areas of the North Atlantic and North Pacific Oceans. In contrast, PAN has only a minor impact in the upper half of the troposphere (+/- 10%). Examining local time series of NOx and PAN, the monthly mean mixing ratios in remote regions are shown to be composed of numerous shortterm (1-2 days) large magnitude events. These episodes are large enough to potentially result in ozone production even when the monthly mean NOx values are in the ozone destruction range. While both the direct transport of NOx and its indirect transport as PAN contribute to the elevated NOx episodes over the remote extratropical oceans, events over the remote subtropical oceans are dominated by midtropospheric PAN that sinks anticyclonically equatorward and decomposes to NOx in the warmer air. C1 GEORGIA INST TECHNOL, SCH EARTH & ATMOSPHER SCI, ATLANTA, GA 30332 USA. RP Moxim, WJ (reprint author), PRINCETON UNIV, NOAA, GEOPHYS FLUID DYNAM LAB, POB 308, PRINCETON, NJ 08542 USA. RI Kasibhatla, Prasad/A-2574-2010 NR 47 TC 137 Z9 139 U1 0 U2 12 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 2169-897X J9 J GEOPHYS RES-ATMOS JI J. Geophys. Res.-Atmos. PD MAY 20 PY 1996 VL 101 IS D7 BP 12621 EP 12638 DI 10.1029/96JD00338 PG 18 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA UN558 UT WOS:A1996UN55800012 ER PT J AU Munger, JW Wofsy, SC Bakwin, PS Fan, SM Goulden, ML Daube, BC Goldstein, AH Moore, KE Fitzjarrald, DR AF Munger, JW Wofsy, SC Bakwin, PS Fan, SM Goulden, ML Daube, BC Goldstein, AH Moore, KE Fitzjarrald, DR TI Atmospheric deposition of reactive nitrogen oxides and ozone in a temperate deciduous forest and a subarctic woodland .1. Measurements and mechanisms SO JOURNAL OF GEOPHYSICAL RESEARCH-ATMOSPHERES LA English DT Article ID DRY DEPOSITION; EDDY-CORRELATION; RURAL SITE; FLUXES; NO2; TROPOSPHERE; VELOCITIES; SURFACE; O-3; FLUCTUATIONS AB We present 5 years of NOy and O-3 eddy flux and concentration measurements and NOx concentration measurements at Harvard Forest (1990-1994), a mixed deciduous forest in central Massachusetts, and 2 months of data for a spruce woodland near Schefferville, Quebec, during the NASA ABLE3B/Northern Wetlands Study (1990). Mean midday values of net dry NOy flux from atmosphere to canopy were 3.4 and 3.2 mu mole m(-2)hr(-1) at Schefferville during summer. Nighttime values were 1.3, 2.0 and 0.15 mu mole m(-2)yr(-1) (2.49 kgN ha(-1)y(-1)). Oxidized species such as HNO3 dominated N deposition, with minor contributions from direct deposition of NO2. Emissions of NO from the forest soil were negligible compared to deposition. Comparision of NOy deposition at Harvard Forest and Schefferville and analysis of the dependence on meteorological parameters show that anthropogenic sources dominate the nitrogen oxide inputs over much of North America. Heterogeneous reactions account for >90% of the conversion of NO2 to HNO3 in winter, leading to rates for dry deposition of NOy similar to fluxes in summer despite 10-fold decrease in OH concentrations. In summer, formation of HNO3 by heterogeneous reactions (mainly at night) could provide 25-45% of the NO2 oxidation. C1 HARVARD UNIV, DEPT EARTH & PLANETARY SCI, CAMBRIDGE, MA 02138 USA. SUNY ALBANY, ATMOSPHER SCI RES CTR, ALBANY, NY 12205 USA. NOAA, CLIMATE MONITORING & DIAGNOST LAB, BOULDER, CO 80303 USA. PRINCETON UNIV, ATMOSPHER & OCEAN SCI PROGRAM, PRINCETON, NJ 08540 USA. UNIV CALIF BERKELEY, DEPT ENVIRONM SCI POLICY & MANAGEMENT, BERKELEY, CA 94720 USA. RP Munger, JW (reprint author), HARVARD UNIV, DIV APPL SCI, 401 ESL, 40 OXFORD ST, CAMBRIDGE, MA 02138 USA. RI Goulden, Michael/B-9934-2008; Goldstein, Allen/A-6857-2011; Munger, J/H-4502-2013 OI Goldstein, Allen/0000-0003-4014-4896; Munger, J/0000-0002-1042-8452 NR 77 TC 101 Z9 102 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 MAY 20 PY 1996 VL 101 IS D7 BP 12639 EP 12657 DI 10.1029/96JD00230 PG 19 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA UN558 UT WOS:A1996UN55800013 ER PT J AU Feng, Y Weiss, RA Karim, A Han, CC Ankner, JF Kaiser, H Peiffer, DG AF Feng, Y Weiss, RA Karim, A Han, CC Ankner, JF Kaiser, H Peiffer, DG TI Compatibilization of polymer blends by complexation .2. Kinetics of interfacial mixing SO MACROMOLECULES LA English DT Article ID POLYSTYRENE IONOMER; MUTUAL DIFFUSION; INTERDIFFUSION; MISCIBILITY; SIZE; METHYL-ETHER); SORPTION; SYSTEMS; OXIDE); MODEL AB The interfacial composition and kinetics of interfacial mixing of two polymers that exhibit strong exothermic interactions, poly(N,N'-dimethylethylenesebacamide) (mPA) and the lithium salt of a lightly sulfonated polystyrene ionomer containing 7.4 mol % sulfonate groups (Li-SPS), were characterized by neutron reflectivity measurements. Blends of Li-SPS and mPA are miscible below ca. 150 degrees C as a result of the formation of an ion-dipole complex between the Li+-sulfonate and amide groups. Neutron reflectivity measurements were carried out on spun-coated bilayer films of the polyamide and a deuterated sample of the ionomer. The films were annealed at 96 degrees C, which is above the melting temperature of the mPA (T-m = 75 degrees C) but below the glass transition temperature of the ionomer (T-g = 120 degrees C). The interface between the two films exhibited an asymmetric concentration profile due to the large viscosity mismatch between the two polymer, and the interfacial mixing followed neither Fickian nor Case II diffusion. A kinetic model that combined Fickian diffusion with a suppression of mobility due to intermolecular crosslinking adequately represented the experimental data. C1 UNIV CONNECTICUT,INST MAT SCI,STORRS,CT 06269. NIST,DIV POLYMERS,GAITHERSBURG,MD 20899. UNIV MISSOURI,RES REACTOR FACIL,COLUMBIA,MO 65211. EXXON RES & ENGN CO,CORP RES LAB,ANNANDALE,NJ 08801. OI Ankner, John/0000-0002-6737-5718 NR 50 TC 19 Z9 19 U1 1 U2 9 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 SN 0024-9297 J9 MACROMOLECULES JI Macromolecules PD MAY 20 PY 1996 VL 29 IS 11 BP 3918 EP 3924 DI 10.1021/ma951723j PG 7 WC Polymer Science SC Polymer Science GA UM264 UT WOS:A1996UM26400033 ER PT J AU Feng, Y Weiss, RA Han, CC AF Feng, Y Weiss, RA Han, CC TI Compatibilization of polymer blends by complexation .3. Structure pinning during phase separation of ionomer/polyamide blends SO MACROMOLECULES LA English DT Article ID STAGE SPINODAL DECOMPOSITION; POLY(2,6-DIMETHYL-1,4-PHENYLENE OXIDE); MISCIBLE BLENDS; POLYSTYRENE; MIXTURES; BEHAVIOR; POLYAMIDE-6; MISCIBILITY; FLUCTUATION; SCATTERING AB The effects of strong intermolecular interactions on the phase behavior and phase separation kinetics of an ionomer/polyamide blend were investigated by light scattering and optical microscopy. The lithium salt of lightly sulfonated polystyrene (Li-SPS) ionomers (4.0-9.5 mol % sulfonation) and poly(N,N'-dimethylethylene sebacamide) (mPA) are miscible as a result of the formation of an ion-amide complex. The blends exhibit LCST-type phase behavior. Phase separation can be thermally induced and is thermodynamically reversible. The phase separation process stalls after a couple of hours due to structure pinning, which may be due to concentration of the ion-amide complexes in a ionomer-rich phase and/or the formation of microphase-separated ionic aggregates in the ionomer-rich phase. C1 UNIV CONNECTICUT,INST MAT SCI,STORRS,CT 06269. NIST,DIV POLYMERS,GAITHERSBURG,MD 20899. NR 40 TC 21 Z9 21 U1 0 U2 2 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 SN 0024-9297 J9 MACROMOLECULES JI Macromolecules PD MAY 20 PY 1996 VL 29 IS 11 BP 3925 EP 3930 DI 10.1021/ma960074o PG 6 WC Polymer Science SC Polymer Science GA UM264 UT WOS:A1996UM26400034 ER PT J AU Zibrov, AS Lukin, MD Hollberg, L Nikonov, DE Scully, MO Robinson, HG Velichansky, VL AF Zibrov, AS Lukin, MD Hollberg, L Nikonov, DE Scully, MO Robinson, HG Velichansky, VL TI Experimental demonstration of enhanced index of refraction via quantum coherence in Rb SO PHYSICAL REVIEW LETTERS LA English DT Article ID ELECTROMAGNETICALLY INDUCED TRANSPARENCY; POPULATION-INVERSION; ATOMIC COHERENCE; INTERFERENCE; AMPLIFICATION; RESONANCES; LASERS AB We present a proof-of-principle experiment demonstrating a resonant enhancement of the index of refraction accompanied by vanishing absorption in a cell containing a coherently prepared Rb vapor. The results are in good agreement with detailed theoretical predictions. C1 HOUSTON ADV RES CTR, TEXAS LASER LAB, THE WOODLANDS, TX 77381 USA. MAX PLANCK INST QUANTUM OPT, D-85748 GARCHING, GERMANY. NATL INST STAND & TECHNOL, BOULDER, CO 80303 USA. PN LEBEDEV PHYS INST, MOSCOW 117924, RUSSIA. RP TEXAS A&M UNIV, DEPT PHYS, COLLEGE STN, TX 77843 USA. RI Nikonov, Dmitri/B-6502-2011; Velichansky, Vladimir/M-4861-2015; Zibrov, Alexander/G-7419-2014 OI Nikonov, Dmitri/0000-0002-1436-1267; NR 29 TC 277 Z9 283 U1 1 U2 13 PU AMER PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 0031-9007 EI 1079-7114 J9 PHYS REV LETT JI Phys. Rev. Lett. PD MAY 20 PY 1996 VL 76 IS 21 BP 3935 EP 3938 DI 10.1103/PhysRevLett.76.3935 PG 4 WC Physics, Multidisciplinary SC Physics GA UL247 UT WOS:A1996UL24700014 ER PT J AU Lynn, JW Erwin, RW Borchers, JA Huang, Q Santoro, A Peng, JL Li, ZY AF Lynn, JW Erwin, RW Borchers, JA Huang, Q Santoro, A Peng, JL Li, ZY TI Unconventional ferromagnetic transition in La1-xCaxMnO3 SO PHYSICAL REVIEW LETTERS LA English DT Article AB Neutron scattering has been used to study the magnetic correlations and long wavelength spin dynamics of La1-xCaxMnO3 in the ferromagnetic regime (0 less than or equal to x < 1/2). For x = 1/3 (T-c = 250 K) where the magnetoresistance effects are largest the system behaves as an ideal isotropic ferromagnet at low T, with a gapless (<0.04 meV) dispersion relation E = D-q(2) and D-T=0 approximate to 170 meV Angstrom(2). However, an anomalous strongly field-dependent diffusive component develops above similar to 200 K and dominates the fluctuation spectrum as T --> T-c. This component is not present at lower x. C1 UNIV MARYLAND,CTR SUPERCONDUCT RES,COLLEGE PK,MD 20742. RP Lynn, JW (reprint author), NATL INST STAND & TECHNOL,DIV REACTOR RADIAT,GAITHERSBURG,MD 20899, USA. NR 22 TC 416 Z9 418 U1 1 U2 14 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 20 PY 1996 VL 76 IS 21 BP 4046 EP 4049 DI 10.1103/PhysRevLett.76.4046 PG 4 WC Physics, Multidisciplinary SC Physics GA UL247 UT WOS:A1996UL24700042 ER PT J AU Jia, JJ Callcott, TA Shirley, EL Carlisle, JA Terminello, LJ Asfaw, A Ederer, DL Himpsel, FJ Perera, RCC AF Jia, JJ Callcott, TA Shirley, EL Carlisle, JA Terminello, LJ Asfaw, A Ederer, DL Himpsel, FJ Perera, RCC TI Resonant inelastic x-ray scattering in hexagonal boron nitride observed by soft-x-ray fluorescence spectroscopy SO PHYSICAL REVIEW LETTERS LA English DT Article ID EXCITATION-ENERGY DEPENDENCE; RAMAN-SCATTERING; EMISSION-SPECTRA; BAND-STRUCTURE; RADIATION; ELECTRON; SI AB Photon-excited B K fluorescence spectra were measured for hexagonal boron nitride using tunable synchrotron radiation below and above the B K edge. We report Raman-like resonant inelastic scattering of soft x rays involving excitation of delocalized valence-band electrons. The inelastic scattering features track with the excitation energy below threshold, go through a resonance as the excitation is tuned to the B(1s) core-exciton energy, and evolve into incoherent fluorescence as the excitation is raised further. The energy loss is identified as equivalent to an electronic transition of valence sigma electrons to pi* conduction-band states. C1 NATL INST STAND & TECHNOL,GAITHERSBURG,MD 20899. LAWRENCE LIVERMORE NATL LAB,LIVERMORE,CA 94551. TULANE UNIV,NEW ORLEANS,LA 70118. UNIV WISCONSIN,MADISON,WI 53706. LAWRENCE BERKELEY LAB,BERKELEY,CA 94720. RP Jia, JJ (reprint author), UNIV TENNESSEE,KNOXVILLE,TN 37996, USA. NR 22 TC 66 Z9 66 U1 1 U2 3 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 0031-9007 J9 PHYS REV LETT JI Phys. Rev. Lett. PD MAY 20 PY 1996 VL 76 IS 21 BP 4054 EP 4057 DI 10.1103/PhysRevLett.76.4054 PG 4 WC Physics, Multidisciplinary SC Physics GA UL247 UT WOS:A1996UL24700044 ER PT J AU Cabezas, H AF Cabezas, H TI Theory of phase formation in aqueous two-phase systems SO JOURNAL OF CHROMATOGRAPHY B-BIOMEDICAL APPLICATIONS LA English DT Article; Proceedings Paper CT 9th International Conference on Partitioning in Aqueous 2-Phase Systems - Advances in the Use of Polymers in Cell Biology, Biotechnology and Environmental Sciences CY JUN 04-09, 1995 CL ZARAGOZA, SPAIN DE reviews; aqueous two-phase systems; phase formation ID MEAN SPHERICAL MODEL; 2-PHASE POLYMER SYSTEMS; THERMODYNAMIC PROPERTIES; POLY(ETHYLENE GLYCOL); 2-POLYMER SYSTEMS; INTEGRAL-EQUATION; STATISTICAL THERMODYNAMICS; POLYELECTROLYTE SOLUTIONS; ASYMMETRIC ELECTROLYTES; SURFACTANT MICELLES AB Currently there are a number of different mathematical models for phase equilibria in aqueous two-phase systems available. This diversity can create some confusion for model users, since most models seem to perform reasonably well. Choosing a model, thus, becomes rather a difficult task. In trying to address this problem, the principal models and the relevant theory available are reviewed. A discussion of osmotic viral expansions, lattice theory, group contribution, scaling ideas, excluded volume, electrostatics and other modeling approaches is presented. The strengths of the different approaches are critically evaluated and suggestions offered. Choosing a model, however, requires sophistication because each model is typically best at representing only a few particular aspects of system behavior, and the intended use of the model must be considered. Some suggestions for future work are also given. C1 NATL INST STAND & TECHNOL,DIV BIOTECHNOL,GAITHERSBURG,MD 20899. RP Cabezas, H (reprint author), US EPA,26 W MARTIN LUTHER KING DR,CINCINNATI,OH 45268, USA. NR 98 TC 62 Z9 63 U1 5 U2 25 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0378-4347 J9 J CHROMATOGR B JI J. Chromatogr. B-Biomed. Appl. PD MAY 17 PY 1996 VL 680 IS 1-2 BP 3 EP 30 DI 10.1016/0378-4347(96)00042-4 PG 28 WC Biochemical Research Methods; Chemistry, Analytical SC Biochemistry & Molecular Biology; Chemistry GA UQ821 UT WOS:A1996UQ82100002 PM 8798878 ER PT J AU Lupton, JE AF Lupton, JE TI A far-field hydrothermal plume from Loihi Seamount SO SCIENCE LA English DT Article ID HAWAII; XENOLITHS; BASALTS; ISLAND; MANTLE; SUMMIT; GASES AB An extensive helium plume in the north central Pacific emanates from Loihi Seamount on the flanks of Hawaii. The maximum helium signal is found at a depth of about 1100 meters, the same depth as the near-field plume directly above Loihi Seamount. Although this helium plume is strongest near Hawaii, where the He-3/He-4 ratio at a depth of about 1100 meters reaches values 28 percent above the atmospheric ratio, it can be detected quite clearly at latitude 24 degrees N, over 400 kilometers to the north. Excess He-3 is also present on the same isopycnal between 15 degrees N and 20 degrees N at 135 degrees W, some 2000 kilometers east of the Hawaiian Islands. RP Lupton, JE (reprint author), NOAA,PACIFIC MARINE ENVIRONM LAB,NEWPORT,OR 97365, USA. NR 34 TC 25 Z9 27 U1 0 U2 5 PU AMER ASSOC ADVANCEMENT SCIENCE PI WASHINGTON PA 1200 NEW YORK AVE, NW, WASHINGTON, DC 20005 SN 0036-8075 J9 SCIENCE JI Science PD MAY 17 PY 1996 VL 272 IS 5264 BP 976 EP 979 DI 10.1126/science.272.5264.976 PG 4 WC Multidisciplinary Sciences SC Science & Technology - Other Topics GA UL619 UT WOS:A1996UL61900034 ER PT J AU DeMartini, EE Donaldson, TJ AF DeMartini, EE Donaldson, TJ TI Color morph-habitat relations in the arc-eye hawkfish Paracirrhites arcatus (Pisces: Cirrhitidae) SO COPEIA LA English DT Article ID CORAL REEFS; FISHES; COMPETITION; COMMUNITY; SELECTION; HAWAII AB The arc-eye hawkfish Paracirrhites arcatus, like other congeners, has multiple color morphs whose relative abundances vary greatly among geographic locations, To gain insight into the environmental factors that potentially influence the morph distributions of this species, we conducted two series of surveys at different spatial scales. One extensive, broad-scale survey of 165 central, south, and western Pacific sites was conducted over a 9-yr period (1986-1993), Another series of sites, located along an exposure gradient on the leeward coast of the Island of Hawaii, was surveyed intensively during 1990-1994. Both surveys revealed that relative abundances of the species' two most common (white-striped, WS; melanistic, MEL) color morphs were independent of microhabitat, body size, or adult sex. Morph frequencies were, however, generally related to bottom depth. Across Oceania, the WS morph was more common at depths > 10 m over a depth range of 1-27 m. At Hawaii, the WS morph increased in abundance at depths > 8 m over a range of 1-12 m and was relatively common at 1-4 m depths wherever frequently used branching corals (Pocillopora meandrina) were scarce. Patterns of color morph frequencies in P. arcatus may represent trade-offs between intraspecific communication and predation risk that exist at differing coral and fish densities. We also discuss morph distributions more generally relative to patterns observed for other, perhaps analogous polychromatisms in reef fishes. C1 KYUSHU UNIV,DEPT FISHERIES,HIGASHI KU,FUKUOKA 812,JAPAN. RP DeMartini, EE (reprint author), NATL MARINE FISHERIES SERV,SW FISHERIES SCI CTR,HONOLULU LAB,2570 DOLE ST,HONOLULU,HI 96822, USA. NR 25 TC 17 Z9 18 U1 0 U2 6 PU AMER SOC ICHTHYOLOGISTS HERPETOLOGISTS BUSINESS OFFICE PI CARBONDALE PA SOUTHERN ILLINOIS UNIV, DEPT ZOOLOGY, CARBONDALE, IL 62901-6501 SN 0045-8511 J9 COPEIA JI Copeia PD MAY 16 PY 1996 IS 2 BP 362 EP 371 DI 10.2307/1446852 PG 10 WC Zoology SC Zoology GA UM949 UT WOS:A1996UM94900011 ER PT J AU Schwarz, FP Misquith, S Surolia, A AF Schwarz, FP Misquith, S Surolia, A TI Effect of substituent on the thermodynamics of D-glucopyranoside binding to concanavalin A, pea (Pisum sativum) lectin and lentil (Lens culinaris) lectin SO BIOCHEMICAL JOURNAL LA English DT Article ID CARBOHYDRATE BINDING; SPECIFICITY; COMPLEX; RESOLUTION AB Titration calorimetry measurements of the binding of phenyl-alpha (alpha PhOGlu), 3-methoxy (3MeOGlu), fluorodeoxy and deoxy derivatives of alpha-D-glucopyranose (Glu) to concanavalin A (conA), pea lectin and lentil lectin were performed at approx. 10 and 25 degrees C in 0.01 M dimethylglutaric acid/NaOH buffer, pH 6.9, containing 0.15 M NaCl and Mn2+ and Ca2+ ions. Apparently the 3-deoxy, 4-deoxy and 6-deoxy as well as the 4-fluorodeoxy and 6-fluorodeoxy derivatives of Glu do not bind to the lectins because no heat release was observed on the addition of aliquots of solutions of these derivatives to the lectin solutions. The binding enthalpies, Delta H degrees(b), and entropies, Delta S degrees(b), determined from the measurements were compared with the same thermodynamic binding parameters for Glu, D-mannopyranoside and methyl-alpha-D-glucopyranoside (alpha MeOGlu). The binding reactions are enthalpically driven with little change in the heat capacity on binding, and exhibit enthalpy-entropy compensation. Differences between the thermodynamic binding parameters can be rationalized in terms of the interactions apparent in the known crystal structures of the methyl-alpha-D-mannopyranoside-conA [Derewenda, Yariv, Helliwell, Kalb (Gilboa), Dodson, Papiz, Wan and Campbell (1989) EMBO J. 8, 2189-2193] and pea lectin-trimanno-pyranoside [Rini, Hardman, Einspahr, Suddath and Carber (1993) J. Biol. Chem. 268, 10126-10132] complexes. Increases in the entropy change on binding are observed for alpha MeOGlu binding to pea and lentil lectin, for alpha PhOGlu binding to conA and pea lectin, and for 3MeOGlu binding to pea lectin relative to the entropy change for Glu binding, and imply that the phenoxy and methoxy substituents provide additional hydrophobic interactions in the complex. Increases in the binding enthalpy relative to that of Glu are observed for deoxy and fluoro derivatives in the C-1 and C-2 positions and imply that these substituents weaken the interaction with the surrounding water, thereby strengthening the interaction with the binding site. C1 INDIAN INST SCI,MOLEC BIOPHYS UNIT,BANGALORE 560012,KARNATAKA,INDIA. RP Schwarz, FP (reprint author), NIST,CTR ADV RES BIOTECHNOL,9600 GUDELSKY DR,ROCKVILLE,MD 20850, USA. RI SUROLIA, AVADESHA/C-5442-2009 NR 31 TC 22 Z9 23 U1 0 U2 2 PU PORTLAND PRESS PI LONDON PA 59 PORTLAND PLACE, LONDON, ENGLAND W1N 3AJ SN 0264-6021 J9 BIOCHEM J JI Biochem. J. PD MAY 15 PY 1996 VL 316 BP 123 EP 129 PN 1 PG 7 WC Biochemistry & Molecular Biology SC Biochemistry & Molecular Biology GA UM293 UT WOS:A1996UM29300018 PM 8645193 ER PT J AU Tung, MS OFarrell, TJ AF Tung, MS OFarrell, TJ TI Effect of ethanol on the formation of calcium phosphates SO COLLOIDS AND SURFACES A-PHYSICOCHEMICAL AND ENGINEERING ASPECTS LA English DT Article DE calcium phosphate; ethanol; hydroxyapatite; precipitate; supersaturation ID APATITE; PRECIPITATION AB In both aqueous and ethanol-water solutions, the first precipitate from a highly supersaturated calcium phosphate solution was amorphous calcium phosphate (ACP) at pH 7.4 and higher. The Ca/P ratio of ACP increased with the increasing pH from 1.28 at pH 7.4 to 1.50 at pH 10.2. In aqueous solutions, ACP rapidly transformed to poorly crystallized hydroxyapatite (PCHA) at pH 7.4. In the ethanol-water solutions, this transformation was slowed down at pH 7.4, but it was accelerated with the addition of 8.9 ppm fluoride or at lower pH of 7.1. The ethanol favors the formation of ACP by the increase in the degree of supersaturation and precipitation rate, and more rapid drying of the precipitated solids. The fluoride and lower pH promote the formation of apatite by shortening the life-time of the ACP. RP Tung, MS (reprint author), NIST,AMER DENT ASSOC HLTH FDN,PAFFENBARGER RES CTR,GAITHERSBURG,MD 20899, USA. NR 18 TC 30 Z9 36 U1 0 U2 4 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0927-7757 J9 COLLOID SURFACE A JI Colloid Surf. A-Physicochem. Eng. Asp. PD MAY 15 PY 1996 VL 110 IS 2 BP 191 EP 198 DI 10.1016/0927-7757(95)03450-1 PG 8 WC Chemistry, Physical SC Chemistry GA UM084 UT WOS:A1996UM08400008 ER PT J AU Hacker, P Firing, E Wilson, WD Molinari, R AF Hacker, P Firing, E Wilson, WD Molinari, R TI Direct observations of the current structure east of the Bahamas SO GEOPHYSICAL RESEARCH LETTERS LA English DT Article ID DEEP WESTERN BOUNDARY; NORTH-ATLANTIC; ABACO-ISLAND; 26.5-DEGREES-N; TRANSPORT AB Quasisynoptic absolute velocity sections were obtained in the western North Atlantic to the east of the Bahamas on five cruises from 1992 to 1994, showing complex spatial and temporal variability of the currents throughout the water column. Lowered acoustic Doppler current profilers were used on all cruises; for comparison, an acoustically-tracked free-fall profiler was used on the August 1992 and June 1993 cruises. Where simultaneous profiles from both methods are available, depth-averaged differences are less than 0.01 m s(-1) in the ensemble mean and standard deviation. Though small, the mean difference appears to be statistically non-zero for one of the two Doppler profilers used; no cause has been found. The individual velocity sections show a banded structure of currents in the offshore direction with strong baroclinic and depth-averaged components extending over the full sampling domain. Two sections show a picture of the southward-flowing Deep Western Boundary Current (DWBC) differing from previous observations. During August 1992 and June 1993 the mean DWBC core was located more than 100 km offshore; in observations prior to 1990 it was usually near 50 km offshore. Net southward transport below 800 m integrated from the coast to 400 km offshore varied from 15 to 50 Sv with a mean of about 40 Sv (1 Sv = 1 x 10(6) m(3) s(-1)). Our mean is consistent with previous estimates; our sections add new evidence that the transport is highly variable to at least 400 km offshore. C1 NOAA,ATLANTIC OCEANOG & METEOROL LAB,MIAMI,FL 33149. RP Hacker, P (reprint author), UNIV HAWAII,JIMAR,SCH OCEAN & EARTH SCI & TECHNOL,1000 POPE RD,MSB 312,HONOLULU,HI 96822, USA. NR 14 TC 27 Z9 27 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 15 PY 1996 VL 23 IS 10 BP 1127 EP 1130 DI 10.1029/96GL01031 PG 4 WC Geosciences, Multidisciplinary SC Geology GA UM113 UT WOS:A1996UM11300017 ER PT J AU Crooker, NU Lazarus, AJ Lepping, RP Ogilvie, KW Steinberg, JT Szabo, A Onsager, TG AF Crooker, NU Lazarus, AJ Lepping, RP Ogilvie, KW Steinberg, JT Szabo, A Onsager, TG TI A two-stream, four-sector, recurrence pattern: Implications from WIND for the 22-year geomagnetic activity cycle SO GEOPHYSICAL RESEARCH LETTERS LA English DT Article ID CURRENT SHEET; EVOLUTION AB Continuous solar wind data from WIND reveals a new recurrence pattern which implies that speed variations contribute to the 22-year cycle of geomagnetic activity. Near December 1994 solstice, in keeping with expectation, a four-sector interplanetary magnetic field pattern was accompanied by four streams. As the season advanced toward March equinox, however, the streams in the two sectors with away polarity diminished, leaving a strikingly unusual two-stream, four-sector pattern until late April. Since the magnetic field pointed toward the sun in both streams, the polarity effect of Russell and McPherron [1973] combined with the high-speed flow resulted in a recurrent pattern of sustained geomagnetic activity during these sector passages. The solar wind pattern is consistent with Earth's excursion to southern heliographic latitudes at March equinox enabling WIND to sample high-speed flow from only the southern coronal hole. The WIND data imply that the 22-year variation in geomagnetic activity results not only from longer immersion in toward sectors in March and away sectors in September during even solar cycles, as proposed by Russell and McPherron [1973], but also from higher flow speeds in those sectors. C1 MIT,CTR SPACE RES,CAMBRIDGE,MA 02139. NASA,GODDARD SPACE FLIGHT CTR,EXTRATERR PHYS LAB,GREENBELT,MD 20771. NOAA,SPACE ENVIRONM CTR,BOULDER,CO 80303. RP Crooker, NU (reprint author), BOSTON UNIV,CTR SPACE PHYS,725 COMMONWEALTH AVE,BOSTON,MA 02215, USA. NR 15 TC 19 Z9 20 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 15 PY 1996 VL 23 IS 10 BP 1275 EP 1278 DI 10.1029/96GL00031 PG 4 WC Geosciences, Multidisciplinary SC Geology GA UM113 UT WOS:A1996UM11300054 ER PT J AU Klaassen, JJ Lindner, J Leone, SR AF Klaassen, JJ Lindner, J Leone, SR TI Observation of the nu(1) OH(OD) stretch of HOI and DOI by Fourier transform infrared emission spectroscopy SO JOURNAL OF CHEMICAL PHYSICS LA English DT Article ID CENTRIFUGAL-DISTORTION ANALYSIS; VIBRATION-ROTATION SPECTRA; ANHARMONIC-FORCE FIELD; HYPOCHLOROUS ACID; HYPOFLUOROUS ACID; EQUILIBRIUM STRUCTURE; MOLECULAR-STRUCTURE; NU-3 BANDS; HOCL; OZONE AB The spectra of vibrationally hot HOI formed in the reaction of alkyl iodides with oxygen atoms are observed by Fourier transform infrared emission spectroscopy. The upsilon = 1-3 levels of the OH stretch are observed via the Delta upsilon = -1 and Delta upsilon = -2 sequence bands. The spectrum of DOI is observed by using 2,2,2-d(3)-iodoethane as the precursor in the oxygen atom reaction. The upsilon = 1-4 levels of the OD stretch are observed in the Delta upsilon = -1 sequence band, and the upsilon = 1-5 levels of the OD stretch are observed in Delta upsilon = -2. Medium resolution spectra (0.031 cm(-1) apodized) are recorded and rotationally analyzed for the nu(1) fundamental and 2 nu(1)-nu(1) hot band of HOI. An estimate of the HOI ground state structure is made by constraining the OH bond length to its value for HOCl and HOBr and calculating the HOI bond angle and the OI bond length by least squares fit to the ground state rotational constants. (C) 1996 American Institute of Physics. C1 UNIV COLORADO, DEPT CHEM & BIOCHEM, BOULDER, CO 80309 USA. RP Klaassen, JJ (reprint author), NATL INST STAND & TECHNOL, JOINT INST LAB ASTROPHYS, BOULDER, CO 80309 USA. NR 67 TC 37 Z9 37 U1 0 U2 2 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 15 PY 1996 VL 104 IS 19 BP 7403 EP 7411 DI 10.1063/1.471456 PG 9 WC Chemistry, Physical; Physics, Atomic, Molecular & Chemical SC Chemistry; Physics GA UK935 UT WOS:A1996UK93500004 ER PT J AU Richter, CA Seiler, DG Pellegrino, JG AF Richter, CA Seiler, DG Pellegrino, JG TI Quantum conductance fluctuations in the large-size-scale regime SO PHYSICAL REVIEW B LA English DT Article ID METALS AB We report the results of experimental studies of ''universal'' conductance fluctuations in a variety of millimeter-sized GaAs/AlxGa1-xAs heterostructures. The ability to observe these mesoscopic fluctuations in traditionally macroscopic semiconductor devices is due to the enhanced sensitivity of our magnetic field modulation measurement technique, which allows a coherent interference effect to be observed and studied in the large-size-scale regime where both the sample length and width are much greater than the quantum scattering lengths. RP NIST, DIV SEMICOND ELECTR, GAITHERSBURG, MD 20899 USA. NR 15 TC 0 Z9 0 U1 0 U2 0 PU AMER PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 2469-9950 EI 2469-9969 J9 PHYS REV B JI Phys. Rev. B PD MAY 15 PY 1996 VL 53 IS 19 BP 13086 EP 13090 DI 10.1103/PhysRevB.53.13086 PG 5 WC Physics, Condensed Matter SC Physics GA UM478 UT WOS:A1996UM47800084 ER PT J AU Kim, YK Silva, TJ AF Kim, YK Silva, TJ TI Magnetostriction characteristics of ultrathin permalloy films SO APPLIED PHYSICS LETTERS LA English DT Article ID THIN AB An abrupt and large increase in the absolute magnitude of lambda(s) in sputtered polycrystalline permalloy (Ni81Fe19) films for thicknesses below 7 nm was observed. Permalloy films maintain near-zero magnetostriction with film thicknesses above 7 nm. Film surface studies and microstructural characterizations suggest that the magnetostriction observed in this study is possibly due to an altered surface morphology of microstructural origin. This observation appears to be critical from the viewpoint of permalloy-based giant magnetoresistive or spin-valve sensor fabrication where typical permalloy film thicknesses are 3-10 nm. Because thin films with nonzero magnetostriction can induce an undesirable magnetoelastic anisotropy during sensor operation, the control and adjustment of the film composition seems necessary to minimize magnetostriction. (C) 1996 American Institute of Physics. C1 NATL INST STAND & TECHNOL,BOULDER,CO 80303. RP Kim, YK (reprint author), QUANTUM PERIPHERALS COLORADO INC,LOUISVILLE,CO 80028, USA. RI Silva, Thomas/C-7605-2013 OI Silva, Thomas/0000-0001-8164-9642 NR 10 TC 40 Z9 40 U1 0 U2 13 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 MAY 13 PY 1996 VL 68 IS 20 BP 2885 EP 2886 DI 10.1063/1.116320 PG 2 WC Physics, Applied SC Physics GA UK569 UT WOS:A1996UK56900038 ER PT J AU Steinbach, AH Martinis, JM Devoret, MH AF Steinbach, AH Martinis, JM Devoret, MH TI Observation of hot-electron shot noise in a metallic resistor SO PHYSICAL REVIEW LETTERS LA English DT Article ID CONDUCTORS; TRANSPORT; CONTACTS AB We have measured the current noise of silver thin-film resistors as a function of current and temperature and for resistor lengths of 7000, 100, 30, and 1 mu m. As the resistor becomes shorter than the electron-phonon interaction length, the current noise for large current increases from a nearly current independent value to the interacting hot-electron value (root 3/4)2eI. However, further reduction in length below the electron-electron interaction length decreases the noise to a value approaching the independent hot-electron value (1/3)2eI first predicted for mesoscopic resistors. C1 CEA SACLAY,SERV PHYS ETAT CONDENSE,F-91191 GIF SUR YVETTE,FRANCE. RP Steinbach, AH (reprint author), NATL INST STAND & TECHNOL,325 BROADWAY,BOULDER,CO 80303, USA. NR 24 TC 180 Z9 181 U1 3 U2 12 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 13 PY 1996 VL 76 IS 20 BP 3806 EP 3809 DI 10.1103/PhysRevLett.76.3806 PG 4 WC Physics, Multidisciplinary SC Physics GA UK560 UT WOS:A1996UK56000037 ER PT J AU Delene, DJ Rose, WI Grody, NC AF Delene, DJ Rose, WI Grody, NC TI Remote sensing of volcanic ash clouds using special sensor microwave imager data SO JOURNAL OF GEOPHYSICAL RESEARCH-SOLID EARTH LA English DT Article ID SNOW COVER; CLASSIFICATION; ERUPTIONS; PARTICLE AB Measurements from the satellite-based special sensor microwave imager (SSM/I) were used to collect passive microwave radiation (19-85 GHz) for the August 19, 1992 (UT date), Crater Peak/Spurr volcanic cloud. This eruption was also imaged by a ground-based C-band radar system at Kenai, Alaska, 80 km away, and by the thermal infrared channels of the polar-orbiting advanced very high resolution radiometer(AVHRR). The SSM/I sensor detects scattering of Earth-emitted radiation by millimeter size volcanic ash particles. The size of ash particles in a volcanic ash cloud can be estimated by comparing the scattering at different microwave frequencies. The mass of particles in the volcanic ash cloud can be estimated by using a theoretical method based on Mie theory or by adapting the empirical methods used for estimating rainfall rates and accounting for the different dielectric constants of volcanic ash and raindrops. For the August 19, 1992, Crater Peak/Spurr eruption, the SSM/I-based estimate of ash fallout mass (1.3 x 10(9) - 3 x 10(10) kg) was 4%-85% of the mass fallout measured in the field. Like weather radar systems, the SSM/I offers the ability to sense young volcanic ash clouds during and immediately following (within 30 min) actual eruptions. Because most volcanoes are out of range of weather radar systems, the SSM/I may be an important tool for determining the magnitude, initial trajectory, and potential fallout mass of eruptions. The SSM/I may therefore play a role in mitigating volcanic cloud hazards for aircraft, determining masses where ground sampling is not possible, and in issuing fallout warnings for communities downwind of volcanic eruptions. C1 MICHIGAN TECHNOL UNIV, DEPT GEOL ENGN & SCI, HOUGHTON, MI 49931 USA. NOAA, SATTELITE RES LAB, MICROWAVE SENSING GRP, CAMP SPRINGS, MD USA. RI Rose, William/A-7923-2009 NR 36 TC 13 Z9 13 U1 0 U2 4 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 2169-9313 EI 2169-9356 J9 J GEOPHYS RES-SOL EA JI J. Geophys. Res.-Solid Earth PD MAY 10 PY 1996 VL 101 IS B5 BP 11579 EP 11588 DI 10.1029/96JB00643 PG 10 WC Geochemistry & Geophysics SC Geochemistry & Geophysics GA UL090 UT WOS:A1996UL09000033 ER PT J AU Mujica, V Kemp, M Roitberg, A Ratner, M AF Mujica, V Kemp, M Roitberg, A Ratner, M TI Current-voltage characteristics of molecular wires: Eigenvalue staircase, Coulomb blockade, and rectification SO JOURNAL OF CHEMICAL PHYSICS LA English DT Article ID SCANNING TUNNELING MICROSCOPE; SUPRAMOLECULAR CHEMISTRY; ELECTRON-TRANSFER; QUANTUM DOTS; PERSPECTIVES; RESISTANCE; SCATTERING; DEVICES; SYSTEMS; MODEL AB We have studied the current vs voltage curves (I-V characteristics) of a mesoscopic device consisting of two electrodes and a molecular wire. The wire Hamiltonian includes both electronic funneling and Coulomb repulsion within a Hubbard model that is treated at the Hartree-Fock level. The inclusion of electron repulsion is an extension of-our previous work that only considered the case of noninteracting electrons. We have found several important features in the calculated characteristics of the wire. These include (1) a staircaselike structure that strongly resembles that associated with Coulomb blockade in heterostructures and quantum dots, but that in the ease of the wire is associated with the discrete nature of the molecular resonances; (2) regions of negative differential resistance associated with increased localization of the molecular resonances. Our theoretical model includes a consistent treatment of the conduction in the linear and nonlinear regimes which remains valid even when the device is operated close to resonance. These results can be particularly relevant for a comparison with recent experiments on molecular wires. (C) 1996 American Institute of Physics. C1 CENT UNIV VENEZUELA, FAC CIENCIAS, ESCUELA QUIM, CARACAS 1020A, VENEZUELA. ECOLE POLYTECH, DEPT GENIE PHYS, MONTREAL, PQ H3C 3A7, CANADA. NATL INST STAND & TECHNOL, GAITHERSBURG, MD 20899 USA. NORTHWESTERN UNIV, DEPT CHEM, EVANSTON, IL 60208 USA. RI Roitberg, Adrian/A-2378-2009 NR 85 TC 271 Z9 272 U1 3 U2 20 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 8 PY 1996 VL 104 IS 18 BP 7296 EP 7305 DI 10.1063/1.471396 PG 10 WC Chemistry, Physical; Physics, Atomic, Molecular & Chemical SC Chemistry; Physics GA UJ114 UT WOS:A1996UJ11400040 ER PT J AU Poirier, GE Pylant, ED White, JM AF Poirier, GE Pylant, ED White, JM TI Crystalline structures of pristine and hydrated mercaptohexanol self-assembled monolayers an Au(111) SO JOURNAL OF CHEMICAL PHYSICS LA English DT Article ID ORGANIC-SURFACES; GOLD; THIOLS AB The crystalline structure of hydroxy-functionalized hexanethiol self-assembled monolayers on Au(111) were characterized using gas-phase transport of molecular precursors and an ultrahigh vacuum scanning tunneling microscope. In the pristine state the monolayer exhibits a commensurate lattice with an oblique primitive unit-cell of dimensions a=3, b=root 13, alpha=a tan(2 root 3); a structure that is fundamentally different than the hexagonal lattice observed for methyl-terminated monolayers. Hydration of the monolayer results in conversion to a polymorphic phase. These results demonstrate the importance of end-group chemical bonding in the molecular packing of this widely studied class of materials. RP Poirier, GE (reprint author), NATL INST STAND & TECHNOL,GAITHERSBURG,MD 20899, USA. NR 21 TC 21 Z9 21 U1 0 U2 8 PU AMER INST PHYSICS PI WOODBURY PA CIRCULATION FULFILLMENT DIV, 500 SUNNYSIDE BLVD, WOODBURY, NY 11797-2999 SN 0021-9606 J9 J CHEM PHYS JI J. Chem. Phys. PD MAY 8 PY 1996 VL 104 IS 18 BP 7325 EP 7328 DI 10.1063/1.471399 PG 4 WC Chemistry, Physical; Physics, Atomic, Molecular & Chemical SC Chemistry; Physics GA UJ114 UT WOS:A1996UJ11400043 ER PT J AU OConnor, WP AF OConnor, WP TI The complex wavenumber eigenvalues of Laplace's tidal equations for oceans bounded by meridians (vol 449, pg 51, 1995) SO PROCEEDINGS OF THE ROYAL SOCIETY A-MATHEMATICAL PHYSICAL AND ENGINEERING SCIENCES LA English DT Correction C1 NOAA, GREAT LAKES ENVIRONM RES LAB, ANN ARBOR, MI 48105 USA. NR 3 TC 3 Z9 3 U1 0 U2 1 PU ROYAL SOC PI LONDON PA 6-9 CARLTON HOUSE TERRACE, LONDON SW1Y 5AG, ENGLAND SN 1364-5021 EI 1471-2946 J9 P ROY SOC A-MATH PHY JI Proc. R. Soc. A-Math. Phys. Eng. Sci. PD MAY 8 PY 1996 VL 452 IS 1948 BP 1185 EP 1187 DI 10.1098/rspa.1996.0060 PG 3 WC Multidisciplinary Sciences SC Science & Technology - Other Topics GA UM391 UT WOS:A1996UM39100011 ER PT J AU Jones, KS Zhang, LH Krishnamoorthy, V Law, M Simmons, DS Chi, P Rubin, L Elliman, RG AF Jones, KS Zhang, LH Krishnamoorthy, V Law, M Simmons, DS Chi, P Rubin, L Elliman, RG TI Diffusion of ion implanted boron in preamorphized silicon SO APPLIED PHYSICS LETTERS LA English DT Article ID AMORPHOUS-SILICON; INTERSTITIALS; VACANCIES; LAYERS; BF2+ AB Transient enhanced diffusion of boron in preamorphized and subsequently regrown Si was studied by secondary ion mass spectrometry (SIMS) and transmission electron microscopy (TEM). A comparison of 4 keV, 1X10(14)/cm(2) baron implants into crystalline and Ge+ preamorphized silicon was undertaken. Upon annealing the B+ implant into crystalline material exhibited the well-known transient enhanced diffusion (TED). In this case the peak of the baron distribution was relatively immobile and only B in the tail showed TED. In the second set of samples, the surface was first preamorphized by a 180 keV, 1x10(15)/cm(2) Ge+ implant which produced an amorphous layer 2300 Angstrom deep, which then was implanted with boron. After implantation the tail of the B distribution extended to only 700 Angstrom. Upon annealing, TED of the boron in the regrown Si was also observed, but the diffusion profile was very different. In this case the peak showed no clustering, so the entire profile diffused. The time for the TED to decay was around 15 min at 800 degrees C. TEM results indicate that the (311) defects in the end of range damage finish dissolving between 10 and 60 min at 800 degrees C. These results indicate that for these Ge preamorphization conditions, not only do the end of range defects not block the flow of interstitials into the regrown silicon, the (311) defects in the end of range damage act as the source of interstitials. In addition, boron does not appear to cluster in regrown silicon. (C) 1996 American Institute of Physics. C1 UNIV FLORIDA, DEPT MAT SCI & ENGN, GAINESVILLE, FL 32611 USA. UNIV FLORIDA, DEPT ELECT ENGN, GAINESVILLE, FL 32611 USA. NATL INST STAND & TECHNOL, CHEM SCI & TECHNOL LAB, GAITHERSBURG, MD 20899 USA. EATON CORP, BEVERLY, MA 01915 USA. AUSTRALIAN NATL UNIV, RES SCH PHYS SCI & ENGN, ELECT MAT PROC DEPT, CANBERRA, ACT 0200, AUSTRALIA. RI Elliman, Robert/B-8542-2009 OI Elliman, Robert/0000-0002-1304-4219 NR 16 TC 49 Z9 50 U1 0 U2 7 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 MAY 6 PY 1996 VL 68 IS 19 BP 2672 EP 2674 DI 10.1063/1.116277 PG 3 WC Physics, Applied SC Physics GA UJ089 UT WOS:A1996UJ08900024 ER PT J AU Irikura, KK MeotNer, M Sieck, LW Fant, AD Liebman, JF AF Irikura, KK MeotNer, M Sieck, LW Fant, AD Liebman, JF TI Protonated p-benzoquinone SO JOURNAL OF ORGANIC CHEMISTRY LA English DT Article ID AFFINITIES AB The structure and energetics of protonated p-benzoquinone (pBQ) have been investigated using high-pressure mass spectrometry and ab initio calculations. The experimental proton affinity of pBQ is 801.4 +/- 8.9 kJ/mol (191.5 +/- 2.1 kcal/mol) (1 sigma) from bracketing measurements and hydration thermochemistry. This value is supported by theory and by analogies with related compounds. In its protonation chemistry, pBQ behaves as an aliphatic ketone, both structurally and energetically. The dissociation of the hydrate (pBQH(+)).(H2O) is characterized by Delta H degrees(D) = 90.0 +/- 2.3 kJ/mol and Delta S degrees D = 123.4 +/- 4.9 J/mol . K (95% confidence). C1 UNIV MARYLAND, DEPT CHEM & BIOCHEM, BALTIMORE, MD 21228 USA. RP 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 35 TC 6 Z9 6 U1 0 U2 6 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 0022-3263 J9 J ORG CHEM JI J. Org. Chem. PD MAY 3 PY 1996 VL 61 IS 9 BP 3167 EP 3171 DI 10.1021/jo951580z PG 5 WC Chemistry, Organic SC Chemistry GA UJ094 UT WOS:A1996UJ09400041 ER PT J AU Berry, RJ Burgess, DRF Nyden, MR Zachariah, MR Melius, CF Schwartz, M AF Berry, RJ Burgess, DRF Nyden, MR Zachariah, MR Melius, CF Schwartz, M TI Halon thermochemistry: Calculated enthalpies of formation of chlorofluoromethanes SO JOURNAL OF PHYSICAL CHEMISTRY LA English DT Article ID SET CORRELATION ENERGIES; VALENCE BOND MODEL; ELECTRONIC-STRUCTURE; GAUSSIAN-2 THEORY; CHEMISTRY; 1ST-ROW; ATOM AB The ab initio G2, G2(MP2), CBS-4, CBS-Q, and BAC-MP4 methods have been used to calculate the enthalpies of formation of the series of four chloromethanes and six chlorofluoromethanes [CHxFyCl4-x-y, x = 0-3, y = 0-3]. Calculated values of Delta(f)H degrees using the first four ab initio methods exhibit comparatively large systematic negative errors compared with experimental values, up to -50 kJ/mol, which are nearly linearly dependent upon the number of C-F and C-Cl bonds in the molecule. It is found for the chlorofluoromethanes that the application of bond additivity corrections (BAC's) to the ab initio enthalpies effectively removes systematic errors in the calculations and yields values that are in close agreement with experimentally derived heats. The rms deviations of the corrected calculated enthalpies from the experimental values are 2.4, 2.6, 3.4, 4.7, and 3.8 kJ/mol for the G2(MP2), G2, CBS-Q, CBS-4, and BAC MP4 methods, respectively. These deviations are lower than the rms errors (6.9 kJ/mol) in the experimental enthalpies. Therefore, it is concluded that any of these calculational procedures, together with bond additivity corrections to remove systematic error, may profitably be used to obtain accurate enthalpies of formation in chlorofluorocarbon species. C1 NATL INST STAND & TECHNOL,GAITHERSBURG,MD 20899. SANDIA NATL LABS,LIVERMORE,CA 94551. UNIV N TEXAS,DEPT CHEM,DENTON,TX 76203. USAF,WRIGHT LAB,MAT DIRECTORATE,WRIGHT PATTERSON AFB,OH 45433. NR 41 TC 43 Z9 43 U1 2 U2 4 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 SN 0022-3654 J9 J PHYS CHEM-US JI J. Phys. Chem. PD MAY 2 PY 1996 VL 100 IS 18 BP 7405 EP 7410 DI 10.1021/jp953427e PG 6 WC Chemistry, Physical SC Chemistry GA UJ117 UT WOS:A1996UJ11700015 ER PT J AU Harvey, AH AF Harvey, AH TI Semiempirical correlation for Henry's constants over large temperature ranges SO AICHE JOURNAL LA English DT Article ID CRITICAL-POINT; SOLUBILITY; BEHAVIOR; WATER RP Harvey, AH (reprint author), NATL INST STAND & TECHNOL,DIV THERMOPHYS,CHEM SCI & TECHNOL LAB,BOULDER,CO 80303, USA. NR 23 TC 95 Z9 96 U1 0 U2 8 PU AMER INST CHEMICAL ENGINEERS PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 SN 0001-1541 J9 AICHE J JI AICHE J. PD MAY PY 1996 VL 42 IS 5 BP 1491 EP 1494 DI 10.1002/aic.690420531 PG 4 WC Engineering, Chemical SC Engineering GA UK322 UT WOS:A1996UK32200030 ER PT J AU LocascioBrown, L Martynova, L Christensen, RG Horvai, G AF LocascioBrown, L Martynova, L Christensen, RG Horvai, G TI Flow immunoassay using solid-phase entrapment SO ANALYTICAL CHEMISTRY LA English DT Article ID ELECTROCHEMICAL ENZYME-IMMUNOASSAY; LIQUID-CHROMATOGRAPHY; AFFINITY-CHROMATOGRAPHY; INJECTION IMMUNOASSAY; ASSAY; MODEL AB A flow injection immunoassay was performed using a column packed with reversed-phase sorbents to effect separation of the immunoreacted species by entrapping free analyte and allowing antibody-conjugated analyte to pass unretained. Fluorescein-labeled analyte was measured in a competitive assay for the anticonvulsant drug phenytoin. The simplicity of the assay was the greatest advantage of the technique, which allowed for measurement of phenytoin in a 2-min assay time. The reliable detection limit for the assay was 5 nmol L(-1) of phenytoin in serum. The columns were regenerated with periodic injections of ethanol solutions to remove the entrapped analyte and prepare the column for subsequent analyses. RP LocascioBrown, L (reprint author), NATL INST STAND & TECHNOL,GAITHERSBURG,MD 20899, USA. RI Horvai, George/F-7274-2010 NR 23 TC 9 Z9 9 U1 0 U2 1 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 SN 0003-2700 J9 ANAL CHEM JI Anal. Chem. PD MAY 1 PY 1996 VL 68 IS 9 BP 1665 EP 1670 DI 10.1021/ac951173n PG 6 WC Chemistry, Analytical SC Chemistry GA UJ085 UT WOS:A1996UJ08500039 PM 21619134 ER PT J AU Richards, GP Zintz, C Chao, J Chao, L AF Richards, GP Zintz, C Chao, J Chao, L TI Purification and characterization of salivary kallikrein from an insectivore (Scalopus aquaticus): Substrate specificities, immunoreactivity, and kinetic analyses SO ARCHIVES OF BIOCHEMISTRY AND BIOPHYSICS LA English DT Article DE characterization; evolution; insectivore; mole; purification; salivary or tissue kallikrein; serine proteinase; kinetics ID TISSUE-SPECIFIC EXPRESSION; HUMAN URINARY KALLIKREIN; GENE FAMILY; RAT; PHYLOGENY; ACTIVATOR; PROTEINS AB We report the successful one-step separation of tissue kallikrein from the salivary glands of an insectivore, the Eastern Atlantic mole (Scalopus aquaticus) by perfusion chromatography. Purified mole salivary kallikrein was characterized as a 50-kDa serine proteinase with a pi of 5.3 and a pH optimum of 9.0. It was readily recognized by human tissue kallikrein antibody in immunoblot analyses. It preferentially hydrolyzes fluorogenic peptidyl substrates with arginyl residues, rather than lysyl residues at the P1 substrate recognition site, indicating that it is like other mammalian kallikreins. Mole kallikrein efficiently releases kinin from low molecular weight human, dog, and bovine kininogen substrates with specific activities similar to that of human tissue kallikrein. Steady state kinetics performed with the synthetic tripeptidyl substrates, Phe-Phe-Arg-, Pro-Phe-Arg-, and Val-Leu-Arg-7-amino-4-methylcoumarin, gave K-m values for mole kallikrein of 3.3, 46.1, and 2.8 mu M, respectively, and specificity constants, k(cat)/K-m, of 3818, 165, and 8714 s(-1) pM(-1), respectively. Mole kallikrein, when compared with human and rat tissue kallikreins, more closely resembles human kallikrein based on immunoreactivity and kininogenase activity. Mole kallikrein appears to be a member of a single gene or small multigene family. S. aquaticus is recommended for studying the evolution of mammalian proteins and may offer advantages over rodent models for biomedical research. (C) 1996 Academic Press, Inc. C1 MED UNIV S CAROLINA,DEPT BIOCHEM & MOLEC BIOL,CHARLESTON,SC 29425. NATL MARINE FISHERIES SERV,SE FISHERIES SCI CTR,CHARLESTON LAB,CHARLESTON,SC 29422. FU NHLBI NIH HHS [HL 29397]; NIDCR NIH HHS [DE 09731] NR 31 TC 6 Z9 6 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 0003-9861 J9 ARCH BIOCHEM BIOPHYS JI Arch. Biochem. Biophys. PD MAY 1 PY 1996 VL 329 IS 1 BP 104 EP 112 DI 10.1006/abbi.1996.0197 PG 9 WC Biochemistry & Molecular Biology; Biophysics SC Biochemistry & Molecular Biology; Biophysics GA UG917 UT WOS:A1996UG91700014 PM 8619626 ER PT J AU Mackey, EA Becker, PR Demiralp, R Greenberg, RR Koster, BJ Wise, SA AF Mackey, EA Becker, PR Demiralp, R Greenberg, RR Koster, BJ Wise, SA TI Bioaccumulation of vanadium and other trace metals in livers of Alaskan cetaceans and pinnipeds SO ARCHIVES OF ENVIRONMENTAL CONTAMINATION AND TOXICOLOGY LA English DT Article ID PHOCOENA-PHOCOENA; MERCURY; ELEMENTS; WHALES; ACCUMULATION; GREENLAND; TITANIUM; PORPOISE; SELENIUM; VANADATE AB Concentrations for 38 elements are routinely measured in the marine mammal liver tissues archived in the National Biomonitoring Specimen Bank (NBSB). Results show that hepatic concentrations of vanadium, selenium, silver, cadmium, and mercury are positively correlated with age for beluga whales (Delphinapterus leucas) and of vanadium, selenium, cadmium, and mercury with length for ringed seals (Phoca hispada). Many researchers have reported linear correlations of hepatic selenium, cadmium, and mercury with marine mammal age; however, there is only one other report of a linear correlation of hepatic vanadium with marine mammal age. Vanadium levels are at or below detection limits (less than or equal to 0.01 mu g/g) in liver tissues of U.S. east coast marine mammals from the NBSB but are present at levels ranging from 0.02 to 1.2 mu g/g of wet weight in the tissues of Alaskan marine mammals. Although only three bearded seal (Eriganthus barbatus) and three bowhead whale (Balaena mysticetus) liver samples have been analyzed, hepatic vanadium levels also increased with animal size for these species. The presence of relatively high levels of vanadium in the livers of these Alaskan animals may reflect a unique dietary source of vanadium, a unique geochemical source of vanadium, or anthropogenic input to the Alaskan marine environment. C1 NOAA, NATL MARINE FISHERIES SERV, OFF PROTECTED RESOURCES, SILVER SPRING, MD 20910 USA. RP Mackey, EA (reprint author), NATL INST STAND & TECHNOL, CHEM SCI & TECHNOL LAB, BLDG 235, GAITHERSBURG, MD 20899 USA. NR 59 TC 54 Z9 54 U1 3 U2 13 PU SPRINGER PI NEW YORK PA 233 SPRING ST, NEW YORK, NY 10013 USA SN 0090-4341 EI 1432-0703 J9 ARCH ENVIRON CON TOX JI Arch. Environ. Contam. Toxicol. PD MAY PY 1996 VL 30 IS 4 BP 503 EP 512 PG 10 WC Environmental Sciences; Toxicology SC Environmental Sciences & Ecology; Toxicology GA UN120 UT WOS:A1996UN12000011 PM 8661527 ER PT J AU Kirchhoff, VWJH Schuch, NJ Pinheiro, DK Harris, JM AF Kirchhoff, VWJH Schuch, NJ Pinheiro, DK Harris, JM TI Evidence for an ozone hole perturbation at 30 degrees south SO ATMOSPHERIC ENVIRONMENT LA English DT Article DE ozone; stratosphere; Brazil; Antarctic ID IMPACT AB A relatively strong stratospheric column ozone decrease was observed in the south of Brazil (29.5 degrees S) in 1993, at the end of October. This ozone decrease was observed when the normal behavior of the ozone column at low latitudes, in Brazil, reaches its yearly maximum, so that a decrease of ozone during this time period is unexpected. The local observations were made by two different measurement techniques. Two independent ground-based Brewer spectrophotometers documented strong column ozone decreases in the south of Brazil, in 1993. The vertical distribution of ozone was observed with ozone-soundings, showing a uniform ozone decrease at all heights in the stratosphere, and very low ozone in the lower stratosphere, which has been shown to be a characteristic of Antarctic ozone in Spring. TOMS ozone data, representing a third observational technique, averaged over small latitude-longitude bands, correlate very well with the local observations, which leaves no doubt that the observed ozone decreases in the south of Brazil during October 1993 were real. Also, the observed ozone decreases may be considered large, since for comparison, the local seasonal variation is at most of the order of 30 Dobson Units (DU), whereas one of the October decreases measured about 60 DU. There seems to be no physical or chemical mechanism at low latitudes, that could account for such a large and fast perturbation in the stratosphere. On the other hand, inspection of the TOMS total ozone data maps, on the days of the above observations, show a distinct link between the Antarctic ozone hole latitudes, reaching out to the north in a curved path, and touching tropical latitudes over a narrow belt. Trajectory analyses confirm that for days of low ozone in Santa. Maria, Brazil, the air masses at 20 and 25 km height have an Antarctic origin. C1 UNIV FED SANTA MARIA, NEPAE, BR-97119900 SANTA MARIA, RS, BRAZIL. NOAA, ENVIRONM RES LABS, BOULDER, CO 80303 USA. RP Kirchhoff, VWJH (reprint author), INST NACL PESQUISAS ESPACIAIS, 12201-970 S JOSE CAMPOS, SAO PAULO, BRAZIL. RI Schuch, Nelson/K-9730-2015 OI Schuch, Nelson/0000-0002-7720-6491 NR 11 TC 48 Z9 50 U1 0 U2 7 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLAND SN 1352-2310 EI 1873-2844 J9 ATMOS ENVIRON JI Atmos. Environ. PD MAY PY 1996 VL 30 IS 9 BP 1481 EP + DI 10.1016/1352-2310(95)00362-2 PG 1 WC Environmental Sciences; Meteorology & Atmospheric Sciences SC Environmental Sciences & Ecology; Meteorology & Atmospheric Sciences GA UG559 UT WOS:A1996UG55900011 ER PT J AU Hill, RJ AF Hill, RJ TI Corrections to Taylor's frozen turbulence approximation SO ATMOSPHERIC RESEARCH LA English DT Article ID HYPOTHESIS; SPECTRA AB Taylor's frozen turbulence approximation relates spatial statistics to temporal statistics. Lumley's two-term approximation gives corrections for the effect of fluctuating convection velocity. Such corrections are derived for every turbulence statistic. The statistic may be a tensor of any rank, and may be a correlation or structure function or spectrum. The practicality of other approximations, such as assuming the convecting velocity to be a Gaussian random variable, is considered as are the inaccuracies of approximations for the case of the dissipation range of spectra. Extensions to cases of multiple-position and space-averaging sensors are noted. Local homogeneity and stationarity and the statistical independence of large-scale and small-scale turbulence quantities are necessary approximations. Local isotropy is shown to be the simplest case of a requirement for local symmetry. Specific expressions are given for isotropic tensors of rank up to fourth rank. Specific expressions are given for the inertial range, for which the correction is shown to vanish to second order for the triple-velocity correlation and structure function. Previous correction formulas are verified, with the exception of the correction for the stress cospectrum, which is shown to have been erroneous. The incompressibility condition is used to simplify the corrections. Fluctuating convection causes erroneous measured compressibility. RP Hill, RJ (reprint author), NOAA,ENVIRONM RES LABS,ENVIRONM TECHNOL LAB,325 BROADWAY,BOULDER,CO 80303, USA. NR 15 TC 22 Z9 23 U1 3 U2 8 PU ELSEVIER SCIENCE INC PI NEW YORK PA 655 AVENUE OF THE AMERICAS, NEW YORK, NY 10010 SN 0169-8095 J9 ATMOS RES JI Atmos. Res. PD MAY PY 1996 VL 40 IS 2-4 BP 153 EP 175 DI 10.1016/0169-8095(95)00032-1 PG 23 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA UR638 UT WOS:A1996UR63800004 ER PT J AU White, AB Fairall, CW Frisch, AS Orr, BW Snider, JB AF White, AB Fairall, CW Frisch, AS Orr, BW Snider, JB TI Recent radar measurements of turbulence and microphysical parameters in marine boundary layer clouds SO ATMOSPHERIC RESEARCH LA English DT Article ID TOP ENTRAINMENT INSTABILITY; AIRCRAFT OBSERVATIONS; STRATOCUMULUS CLOUDS; LIQUID WATER; MIXED LAYERS; MODEL; STABILITY AB We present a collection of research related to radar measurements of turbulence and microphysical properties in clouds. The radars used in these studies operate at frequencies ranging from 404 MHz to 34.6 GHz, We discuss the relative contributions made by the two primary radar scattering mechanisms to the measured values of radar reflectivity at the different frequencies. The desired turbulence and microphysical information is obtained from the radar reflectivity and other elements of the Doppler velocity spectra. Methods and examples are given with emphasis on liquid water clouds associated with the marine boundary layer. C1 NOAA,ENVIRONM TECHNOL LAB,BOULDER,CO. RP White, AB (reprint author), UNIV COLORADO,NOAA,COOPERAT INST RES ENVIRONM SCI,BOULDER,CO 80309, USA. RI White, Allen/A-7946-2009 NR 78 TC 10 Z9 11 U1 0 U2 2 PU ELSEVIER SCIENCE INC PI NEW YORK PA 655 AVENUE OF THE AMERICAS, NEW YORK, NY 10010 SN 0169-8095 J9 ATMOS RES JI Atmos. Res. PD MAY PY 1996 VL 40 IS 2-4 BP 177 EP 221 DI 10.1016/0169-8095(95)00036-4 PG 45 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA UR638 UT WOS:A1996UR63800005 ER PT J AU Reddy, P McKenney, K AF Reddy, P McKenney, K TI Improved method for the production of M13 phage and single-stranded DNA for DNA sequencing SO BIOTECHNIQUES LA English DT Article AB An improved method is described for the efficient production of M13 phage and M13 single-stranded (ss)DNA in a relatively short time period. Infection of E. coli (F') cells with as few as 5 phage particles can yield 10(12) phage particles/mL in 3 hours if the cells are grown in LB broth or SOB broth supplemented with about 5 mM Mg2+. The method tolerates large variations in the initial multiplicity of infection (5-5000 phage per 5 x 10(7) cells) and still yields about 10(12) phage particles/mL. These amounts are sufficient to purify 10-15 mu g of ssDNA and to carry out at least 10-15 DNA sequencing reactions. RP Reddy, P (reprint author), NIST,DIV BIOTECHNOL,BLDG 222,RM A 359,GAITHERSBURG,MD 20899, USA. NR 0 TC 1 Z9 1 U1 0 U2 3 PU EATON PUBLISHING CO PI NATICK PA 154 E. CENTRAL ST, NATICK, MA 01760 SN 0736-6205 J9 BIOTECHNIQUES JI Biotechniques PD MAY PY 1996 VL 20 IS 5 BP 854 EP & PG 4 WC Biochemical Research Methods; Biochemistry & Molecular Biology SC Biochemistry & Molecular Biology GA UJ638 UT WOS:A1996UJ63800025 PM 8723931 ER PT J AU DeMartini, EE Parrish, FA Parrish, JD AF DeMartini, EE Parrish, FA Parrish, JD TI Interdecadal change in reef fish populations at French Frigate Shoals and Midway Atoll, northwestern Hawaiian Islands: Statistical power in retrospect SO BULLETIN OF MARINE SCIENCE LA English DT Article ID SPATIAL VARIATION; RECRUITMENT; ASSEMBLAGES; ABUNDANCE; PATTERNS AB Reef fish faunas were compared between surveys conducted more than a decade apart at each of two isolated and nearly pristine oceanic atolls (French Frigate Shoals [FFS] and Midway Atoll) in the northwestern Hawaiian Islands. Species composition, assemblage structure (density rankings), and population densities were compared to test the hypothesis that reef fishes had declined during a period of lower oceanic productivity in the central North Pacific. Within each of two principal habitats (barrier and patch reefs) at each atoll, species composition and rank densities differed little between sampling periods. Densities, however, generally declined by about one-third for many numerically dominant species and for tars pooled into functional categories (trophic levels, feeding guilds). Patterns of temporal change were partly confounded by distributional shifts between barrier and patch reef habitats at FFS, perhaps reflecting indirect effects of storm disturbance on benthic algal habitat. Such effects, together with related changes in climate and oceanic productivity on an interdecadal time scale, might have been responsible for the apparent declines in reef fish densities al both atolls. Temporal patterns were clearer at Midway Atoll, where changes in benthic algae were not evident. Our observations indicate that the statistical power necessary to detect changes in the population densities of reef fish species that exhibit large temporal fluctuations in numbers, particularly on oceanic islands, is generally low. Power to detect twofold changes may be adequate, however, if taxa are pooled into functional categories. C1 UNIV HAWAII, HAWAII COOPERAT FISHERY RES UNIT, NATL BIOL SERV, HONOLULU, HI 96822 USA. RP NOAA, NATL MARINE FISHERIES SERV, SW FISHERIES SCI CTR, HONOLULU LAB, 2570 DOLE ST, HONOLULU, HI 96822 USA. NR 49 TC 17 Z9 18 U1 0 U2 5 PU ROSENSTIEL SCH MAR ATMOS SCI PI MIAMI PA 4600 RICKENBACKER CAUSEWAY, MIAMI, FL 33149 USA SN 0007-4977 EI 1553-6955 J9 B MAR SCI JI Bull. Mar. Sci. PD MAY PY 1996 VL 58 IS 3 BP 804 EP 825 PG 22 WC Marine & Freshwater Biology; Oceanography SC Marine & Freshwater Biology; Oceanography GA UP205 UT WOS:A1996UP20500015 ER PT J AU DeMartini, EE AF DeMartini, EE TI Sheltering and foraging substrate uses of the arc-eye hawkfish Paracirrhites arcatus (Pisces: Cirrhitidae) SO BULLETIN OF MARINE SCIENCE LA English DT Article ID HABITAT SELECTION; PREDATION RISK; CORAL REEFS; MINNOWS; PATTERNS; HAWAII; FISHES AB A combination of free-ranging snorkel surveys and focal-animal observations was used to evaluate substrate use by the arc-eye hawkfish Paracirrhites arcatus, a typical cirrhitid recognized for its conspicuous ''perching'' and ambushing behavior, The arc-eye hawkfish used different substrates for sheltering and for foraging. Pocillopora meandrina, the only common species of closely branched coral in the main Hawaiian Islands, was the perch most frequently encountered (>96% of all cases) on snorkel surveys at seven sites on the leeward side of the Island of Hawaii. P. arcatus refuged within Poc, meandrina whenever predators approached closely, but darted out from coral heads to feed. Foraging strikes were directed mainly at targets on benthic substrates surrounding Poc. meandrina refuges; strikes were primarily directed (81-96% of all strikes) at prey on rock/dead coral substrate that dominated cover (43-90%) at the study sites. P. arcatus also fed to a major extent within the near-bottom water column. The dichotomy between preferred foraging and sheltering substrates is discussed relative to the trade-off between foraging benefit and risk of predation hazard when the two substrates differ. RP DeMartini, EE (reprint author), NOAA, NATL MARINE FISHERIES SERV, SW FISHERIES SCI CTR, HONOLULU LAB, 2570 DOLE ST, HONOLULU, HI 96822 USA. NR 30 TC 8 Z9 9 U1 2 U2 7 PU ROSENSTIEL SCH MAR ATMOS SCI PI MIAMI PA 4600 RICKENBACKER CAUSEWAY, MIAMI, FL 33149 USA SN 0007-4977 J9 B MAR SCI JI Bull. Mar. Sci. PD MAY PY 1996 VL 58 IS 3 BP 826 EP 837 PG 12 WC Marine & Freshwater Biology; Oceanography SC Marine & Freshwater Biology; Oceanography GA UP205 UT WOS:A1996UP20500016 ER PT J AU Watson, AI Holle, RL AF Watson, AI Holle, RL TI An eight-year lightning climatology of the southeast United States prepared for the 1996 Summer Olympics SO BULLETIN OF THE AMERICAN METEOROLOGICAL SOCIETY LA English DT Article ID THUNDERSTORM AB The 1996 Summer Olympics will be held in the Atlanta, Georgia, vicinity and several other sites in the southeast United States between 19 July and 4 August 1996. This period coincides with the peak thunderstorm season, so the threat of lightning casualties cannot be taken Lightly since Georgia and surrounding states with Olympic venues rank quite high in the United States in annual lightning casualties and the casualty rate per population. Flash density and thunderstorm day estimates for July and August show that the greatest cloud-to-ground (CG) lightning activity (> 5 flashes per square kilometer) occurs near the seacoasts and over the Florida peninsula. Cloud-to-ground flash activity decreases as distances increase from the coastlines, reaching a minimum (< 1 flash per square kilometer) along the North Carolina-Tennessee border. However, there are also important maxima (> 3 flashes per square kilometer) in and around Atlanta. The frequency of CG lightning reaches a maximum in the late afternoon and early evening hours in the Atlanta area. Lightning reaches a maximum in the midafternoon at Wassau Sound near Savannah Beach. As expected, the lowest chances of lightning are from midnight to noon, while probabilities are slightly greater during these hours along the coasts. Flash densities for July and August may vary as much as 2-3 flashes per square kilometer from year to year in most locations. When lightning begins, the chances are greater than 1 in 3 that lightning will still be occurring 1 h later at most venue sites; the chances are 1 in 5 that lightning will be present after 2 h. RP Watson, AI (reprint author), NOAA,ENVIRONM RES LAB,NATL SEVERE STORMS LAB,1313 HALLEY CIRCLE,NORMAN,OK 73069, USA. NR 11 TC 17 Z9 17 U1 1 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 MAY PY 1996 VL 77 IS 5 BP 883 EP 890 DI 10.1175/1520-0477(1996)077<0883:AEYLCO>2.0.CO;2 PG 8 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA UN464 UT WOS:A1996UN46400003 ER PT J AU Ferraro, RR Weng, FZ Grody, NC Basist, A AF Ferraro, RR Weng, FZ Grody, NC Basist, A TI An eight-year (1987-1994) time series of rainfall, clouds, water vapor, snow cover, and sea ice derived from SSM/I measurements SO BULLETIN OF THE AMERICAN METEOROLOGICAL SOCIETY LA English DT Article ID PRECIPITABLE WATER; OCEANS AB The Special Sensor Microwave/lmager (SSM/I), first placed into operation in July 1987, has been making measurements of earth-emitted radiation for over eight years. These data are used to estimate both atmospheric and surface hydrological parameters and to generate a time series of global monthly mean products averaged to a 1 degrees lat x 1 degrees long grid. Specifically, this includes monthly estimates of rainfall and its frequency, cloud liquid water and cloud frequency, water vapor, snow cover frequency, and sea ice frequency. This study uses seasonal mean values to demonstrate the spatial and temporal distributions of these hydrological variables. Examples of interannual variability such as the 1993 flooding in the Mississippi Valley and the 1992-93 snow cover changes over the United States are used to demonstrate the utility of these data for regional applications. C1 NOAA,CLIMATE PREDICT CTR,CAMP SPRINGS,MD. RP Ferraro, RR (reprint author), NOAA,SATELLITE RES LAB,OFF RES & APPLICAT,MICROWAVE SENSING GRP,E-RA 12,5200 AUTH RD,ROOM 712,CAMP SPRINGS,MD 20746, USA. RI Weng, Fuzhong/F-5633-2010; Ferraro, Ralph/F-5587-2010 OI Weng, Fuzhong/0000-0003-0150-2179; Ferraro, Ralph/0000-0002-8393-7135 NR 27 TC 183 Z9 190 U1 0 U2 1 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 1996 VL 77 IS 5 BP 891 EP 905 DI 10.1175/1520-0477(1996)077<0891:AEYTSO>2.0.CO;2 PG 15 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA UN464 UT WOS:A1996UN46400004 ER PT J AU Douglas, MW Stensrud, DJ AF Douglas, MW Stensrud, DJ TI Upgrading the North American upper-air observing network: What are the possibilities? SO BULLETIN OF THE AMERICAN METEOROLOGICAL SOCIETY LA English DT Article ID 4-DIMENSIONAL DATA ASSIMILATION; NATIONAL-METEOROLOGICAL-CENTER; MESOSCALE CONVECTIVE SYSTEMS; AIRCRAFT; MODELS; INITIALIZATION; FORECASTS; PROFILERS; RASS AB The current modernization and restructuring of the National Weather Service (NWS) to date has not involved the rehabilitation of the upper-air observing network over North America. The authors discuss the need for a thorough evaluation of the current upper-air observing system that examines both the old (current) rawinsonde network and newer remote sensing networks. The key concern is that the meteorological community has given insufficient attention to the scientific questions underlying the choices of observing systems as related to the needs of operational forecasting. The authors argue that the principal basis for a scientific and objective evaluation of observing strategies is the ability of a particular observing system (or component of a system) to improve numerical weather prediction in the modernized NWS. Given this starting point. a number of possible new (and old) observing systems and observing strategies are discussed that offer the possibility for much improved initialization of mesoscale numerical forecast models. Perhaps the key shift in observation strategy suggested is the establishment of many additional radiosonde and pilot balloon sounding stations that rely on contract observers rather than the NWS workforce. However, a comprehensive and satisfactory upgrading of the upper-air observing system will be possible only after more substantial participation of the scientific community in the planning and implementation processes. RP NOAA, NATL SEVERE STORMS LAB, 1313 HALLEY CIRCLE, NORMAN, OK 73069 USA. NR 65 TC 9 Z9 9 U1 0 U2 0 PU AMER METEOROLOGICAL SOC PI BOSTON PA 45 BEACON ST, BOSTON, MA 02108-3693 USA SN 0003-0007 EI 1520-0477 J9 B AM METEOROL SOC JI Bull. Amer. Meteorol. Soc. PD MAY PY 1996 VL 77 IS 5 BP 907 EP 924 DI 10.1175/1520-0477(1996)077<0907:UTNAUA>2.0.CO;2 PG 18 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA UN464 UT WOS:A1996UN46400005 ER PT J AU Burpee, RW Franklin, JL Lord, SJ Tuleya, RE Aberson, SD AF Burpee, RW Franklin, JL Lord, SJ Tuleya, RE Aberson, SD TI The impact of Omega dropwindsondes on operational hurricane track forecast models SO BULLETIN OF THE AMERICAN METEOROLOGICAL SOCIETY LA English DT Article ID PREDICTION; SYSTEM; INITIALIZATION AB Since 1982, the Hurricane Research Division (HRD) has conducted a series of experiments with research aircraft to enhance the number of observations in the environment and the core of hurricanes threatening the United States. During these experiments, the National Oceanic and Atmospheric Administration WP 3D aircraft crews release Omega dropwindsondes (ODWs) at 15-20-min intervals along the flight track to obtain profiles of wind, temperature, and humidity between flight level and the sea surface. Data from the ODWs are transmitted back to the aircraft and then sent via satellite to the Tropical Prediction Center and the National Centers for Environmental Prediction (NCEP), where the observations become part of the operational database. This paper tests the hypothesis that additional observations improve the objective track forecast models that provide operational guidance to the hurricane forecasters. The testing evaluates differences in forecast tracks from models run with and without the ODW data in a research mode at HRD, NCEP, and the Geophysical Fluid Dynamics Laboratory. The middle- and lower-tropospheric ODW data produce statistically significant reductions in 12-60-h mean forecast errors. The error reductions, which range from 16% to 30%, are at least as large as the accumulated improvement in operational forecasts achieved over the last 20-25 years. This breakthrough provides strong experimental evidence that more comprehensive observations in the hurricane environment and core will lead to immediate improvements in operational forecast guidance. C1 NOAA,NATL CTR ENVIRONM PREDICT,CAMP SPRINGS,MD. PRINCETON UNIV,NOAA,GEOPHYS FLUID DYNAM LAB,PRINCETON,NJ 08542. NOAA,ATLANTIC OCEANOG & METEOROL LAB,HURRICANE RES DIV,MIAMI,FL 33149. RI Aberson, Sim/C-4891-2013 OI Aberson, Sim/0000-0002-3670-0100 NR 29 TC 83 Z9 85 U1 0 U2 1 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 1996 VL 77 IS 5 BP 925 EP 933 DI 10.1175/1520-0477(1996)077<0925:TIOODO>2.0.CO;2 PG 9 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA UN464 UT WOS:A1996UN46400006 ER PT J AU Lewis, JM AF Lewis, JM TI Winds over the world sea: Maury and Koppen SO BULLETIN OF THE AMERICAN METEOROLOGICAL SOCIETY LA English DT Article AB In response to the needs of the ocean traders and military shipping during the nineteenth century, Matthew Maury (1806-73) and Wladimir Koppen (1846-1940) worked in tandem to create wind charts for the World Ocean. In the early part of the century, Maury organized and supervised the production of the Wind and Current Charts for all navigable seas. In the latter part of the century, Koppen simplified these charts by use of a synoptically innovative stratification of the data, and these analyses became centerpieces of the Segelhandbucher (Sail Handlbooks) produced by the German Marine Observatory (Seewarte). The charts produced by each of these men are examined in an effort to clarify their separate but unique contributions. Maury and Koppen were complementary in their approach to marine meteorology. Maury possessed organizational skills and an empirical approach to science, while Koppen was more academic and interested in the basic sciences. Koppen's exceptional background in both physics and biology was instrumental to his success in simplifying Maury's charts. These appealing synoptic charts served Bergeron in his quest for a global understanding of air masses and ultimately gave Koppen a viewpoint on climatology that embraced the entire world. RP Lewis, JM (reprint author), NOAA,ENVIRONM RES LAB,NATL SEVERE STORMS LAB,1313 HALLEY CIRCLE,NORMAN,OK 73069, USA. NR 59 TC 6 Z9 6 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 MAY PY 1996 VL 77 IS 5 BP 935 EP 952 DI 10.1175/1520-0477(1996)077<0935:WOTWSM>2.0.CO;2 PG 18 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA UN464 UT WOS:A1996UN46400007 ER PT J AU Willoughby, HE Black, PG AF Willoughby, HE Black, PG TI Hurricane Andrew in Florida: Dynamics of a disaster (vol 77, pg 543, 1996). SO BULLETIN OF THE AMERICAN METEOROLOGICAL SOCIETY LA English DT Correction, Addition RP Willoughby, HE (reprint author), NOAA,ATLANTIC OCEANOG & METEOROL LAB,HURRICANE RES DIV,MIAMI,FL 33149, USA. NR 1 TC 0 Z9 0 U1 1 U2 1 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 1996 VL 77 IS 5 BP 962 EP 962 PG 1 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA UN464 UT WOS:A1996UN46400009 ER PT J AU Halpert, MS Bell, GD Kousky, VE Ropelewski, CF AF Halpert, MS Bell, GD Kousky, VE Ropelewski, CF TI Climate assessment for 1995 SO BULLETIN OF THE AMERICAN METEOROLOGICAL SOCIETY LA English DT Article ID PATTERNS AB The El Nino-Southern Oscillation (ENSO) phenomenon is a major contributor to the observed year-to-year variability in the Pacific Ocean and in the global atmospheric circulation. The short-term climate system witnessed the return to the mature phase of warm ENSO conditions (commonly referred to as the El Nino) during early 1995 for the third time in four years. This frequency of occurrence is unprecedented in the last 50 years and is comparable to that observed during the prolonged 1911-15 ENSO episode. These warm ENSO conditions contributed to a large-scale disruption of the normal patterns of wind, rainfall, and temperature over much of the tropics and middle latitudes, particularly during the December 1994-February 1995 period. This period was followed by a dramatic decrease in sea surface temperatures in the tropical Pacific, resulting in a complete disappearance of all warm episode conditions during June-August and in the development of weak cold-episode conditions during September-November. Changes in the tropical Pacific were accompanied by pronounced, large-scale changes in the atmospheric circulation patterns from those that had prevailed during much of the early 1990s. Particular examples of these changes include 1) a dramatic return to a very active hurricane season over the North Atlantic, following four consecutive years of significantly below-normal hurricane activity; 2) the return to above-normal rainfall throughout Indonesia, northern Australia, and southern Africa, following a prolonged period of below-normal rainfall and periodic drought; and 3) a northward shift of the jet stream and storm track position over the eastern half of the North Pacific during the latter part of the year, following several winter seasons (three in the last four) characterized by a significant strengthening, southward shift, and eastward extension of these features toward the southwestern United States. Other regional climate anomalies during 1995 included extreme warmth throughout western and central Asia during January-May and colder than normal conditions in this region during November-December, severe flooding in the midwestern United States (April-May), abnormally wet conditions in California and the southwestern United States (December-February) combined with near-record warmth over eastern North America, deadly heat waves in the central United States (mid-July) and India (first three weeks of June), drought in the northeastern United States (August), a drier-than-normal rainy season in central Brazil (September-December), and an intensification of drier-than-normal conditions over southern Brazil, Uruguay, and northeastern Argentina at the end of the year. The global annual mean surface temperature for land and marine areas during 1995 averaged 0.40 degrees C above the 1961-90 mean. This value exceeds the previous warmest year in the record (1990) by 0.04 degrees C. The Northern Hemisphere also recorded its warmest year on record during 1995, with a mean departure from normal of 0.55 degrees C. The global annual mean surface temperature for land areas only during 1995 was the second warmest since 1951. The year also witnessed near-record low ozone amounts in the Southern Hemisphere stratosphere, with minimum values only slightly higher than the record low values observed in 1993. The areal extent of very low ozone values during 1995 was as widespread over Antarctica as in the record low year of 1993. C1 NOAA,NATL WEATHER SERV,NCEP,CLIMATE PREDICT CTR,WASHINGTON,DC 20233. NR 22 TC 14 Z9 14 U1 1 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 MAY PY 1996 VL 77 IS 5 BP S1 EP S44 PG 44 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA UN464 UT WOS:A1996UN46400013 ER PT J AU Skrtic, D Eidelman, N Golomb, G Breuer, E Eanes, ED AF Skrtic, D Eidelman, N Golomb, G Breuer, E Eanes, ED TI In vitro inhibition of membrane-mediated calcification by novel phosphonates SO CALCIFIED TISSUE INTERNATIONAL LA English DT Article DE geminal bisphosphonates; bone disorders; hydroxyapatite; calcium metabolism disorders ID AQUEOUS SUSPENSIONS; CALCIUM PHOSPHATES; HYDROXYAPATITE; LIPOSOMES; DIPHOSPHONATES; CRYSTALS; VESICLES; INVITRO; BINDING; INVIVO AB The effects of a series of novel phosphonates on the kinetics of mineral development in an ionophore-primed 7:2:1 phosphatidylcholine (PC): dicetylphosphate (DCP): cholesterol (Chol) liposomal model system are reported. When present at 2.5 mu mol/liter or 25 mu mol/liter concentrations in the solution surrounding the liposomes, the investigated phosphonates did not significantly delay the initial formation of hydroxyapatite-like calcium phosphate salts (HAP) within the liposomes or the penetration of HAP crystals through the enclosing membranes. However, the phosphonates variably retarded the subsequent growth and proliferation of the HAP crystals once they became directly exposed to the phosphonate-containing solution. The effectiveness of phosphonates in inhibiting extraliposomal precipitation strongly depended on their structure. The inhibitory action on active surface growth sites of released intraliposomal crystals was found to be the most effective if the phosphonate molecule contained two phosphonic groups Linked to the same C atom. At a phosphonate concentration of 25 mu mol/liter, the following general order of effectiveness was established: geminal bisphosphonate greater than or equal to geminal tetrakisphosphonate > bisacylphosphonates > monoacylphosphonate > bisalkylphosphonate. Within the bisacylphosphonate family, the highest inhibitory action was observed when four or five -CH2- groups separated the ketophosphonic groups. C1 NATL INST STAND & TECHNOL,NIDR,BONE RES BRANCH,ASSOCIATE PROGRAM,GAITHERSBURG,MD 20899. NATL INST STAND & TECHNOL,AMER DENT ASSOC HLTH FDN,PAFFENBARGER RES CTR,GAITHERSBURG,MD 20899. RUDJER BOSKOVIC INST,DEPT CHEM,ZAGREB 41000,CROATIA. HEBREW UNIV JERUSALEM,SCH PHARM,DEPT PHARM,IL-91120 JERUSALEM,ISRAEL. HEBREW UNIV JERUSALEM,SCH PHARM,DEPT PHARMACEUT CHEM,IL-91120 JERUSALEM,ISRAEL. RI Breuer, Eli/E-8382-2011; OI Golomb, Gershon/0000-0002-7369-9831 FU NHLBI NIH HHS [HL 30035] NR 34 TC 13 Z9 14 U1 0 U2 0 PU SPRINGER VERLAG PI NEW YORK PA 175 FIFTH AVE, NEW YORK, NY 10010 SN 0171-967X J9 CALCIFIED TISSUE INT JI Calcif. Tissue Int. PD MAY PY 1996 VL 58 IS 5 BP 347 EP 354 DI 10.1007/BF02509384 PG 8 WC Endocrinology & Metabolism SC Endocrinology & Metabolism GA UJ247 UT WOS:A1996UJ24700009 PM 8661970 ER PT J AU Liu, D Malghan, SG AF Liu, D Malghan, SG TI Role of polyacrylate in modifying interfacial properties and stability of silicon nitride particles in aqueous suspensions SO COLLOIDS AND SURFACES A-PHYSICOCHEMICAL AND ENGINEERING ASPECTS LA English DT Article DE dispersion; electrostatic interactions; polyacrylate; silicon nitride; steric interactions; surface modifications ID ADSORPTION; ACID AB The role of ammonium polyacrylate in modifying the interfacial properties of silicon nitride powder was examined systematically in order to understand the basic mechanism of dispersion. The adsorption of the polyacrylate on silicon nitride powder was found to be dependent on both the pH and its residual (equilibrium) concentration. The interfacial charge properties of the silicon nitride powder can be modified to a large extent by the adsorbed polyacrylate and equilibrium pH. Well-dispersed silicon nitride suspensions can be obtained in both the neutral and alkaline pH range by the application of ammonium polyacrylate. The enhanced electrostatic repulsion between the dispersant-modified powder surfaces was found to be the primary mechanism governing the dispersion. Also, the steric interactions of the adsorbed polyacrylate with aqueous media were demonstrated in this work to have a positive contribution to the dispersion. The latter is attributed to the hydrophilic nature of the polyacrylate. The dispersing functions of the adsorbed polyacrylate were understood to arise from the two oxygen atoms in the carboxylic group of the polyacrylate. The charged oxygen atom in the carboxylic group was responsible for the measured interfacial charge properties of the dispersant-modified powder. The uncharged oxygen atom had an additional contribution to the hydrophilic nature of the adsorbed dispersant layer. C1 NIST,DIV CERAM,GAITHERSBURG,MD 20899. NR 13 TC 20 Z9 25 U1 1 U2 5 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0927-7757 J9 COLLOID SURFACE A JI Colloid Surf. A-Physicochem. Eng. Asp. PD MAY 1 PY 1996 VL 110 IS 1 BP 37 EP 45 DI 10.1016/0927-7757(95)03441-2 PG 9 WC Chemistry, Physical SC Chemistry GA UL995 UT WOS:A1996UL99500004 ER PT J AU Mangel, M Talbot, LM Meffe, GK Agardy, MT Alverson, DL Barlow, J Botkin, DB Budowski, G Clark, T Cooke, J Crozier, RH Dayton, PK Elder, DL Fowler, CW Funtowicz, S Giske, J Hofman, RJ Holt, SJ Kellert, SR Kimball, LA Ludwig, D Magnusson, K Malayang, BS Mann, C Norse, EA Northridge, SP Perrin, WF Perrings, C Peterman, RM Rabb, GB Regier, HA Reynolds, JE Sherman, K Sissenwine, MP Smith, TD Starfield, A Taylor, RJ Tillman, MF Toft, C Twiss, JR Wilen, J Young, TP AF Mangel, M Talbot, LM Meffe, GK Agardy, MT Alverson, DL Barlow, J Botkin, DB Budowski, G Clark, T Cooke, J Crozier, RH Dayton, PK Elder, DL Fowler, CW Funtowicz, S Giske, J Hofman, RJ Holt, SJ Kellert, SR Kimball, LA Ludwig, D Magnusson, K Malayang, BS Mann, C Norse, EA Northridge, SP Perrin, WF Perrings, C Peterman, RM Rabb, GB Regier, HA Reynolds, JE Sherman, K Sissenwine, MP Smith, TD Starfield, A Taylor, RJ Tillman, MF Toft, C Twiss, JR Wilen, J Young, TP TI Principles for the conservation of wild living resources SO ECOLOGICAL APPLICATIONS LA English DT Article ID STATISTICAL POWER ANALYSIS; RANGE CONDITION; MANAGEMENT; SUSTAINABILITY; EXTINCTION; THRESHOLDS; VIEWPOINT; FISHERIES; SCIENCE; ECOLOGY AB We describe broadly applicable principles for the conservation of wild living resources and mechanisms for their implementation. These principles were engendered from three starting points. First, a set of principles for the conservation of wild living resources (Holt and Talbot 1978) required reexamination and updating. Second, those principles lacked mechanisms for implementation and consequently were not as effective as they might have been. Third, all conservation problems have scientific, economic, and social aspects, and although the mix may vary from problem to problem, all three aspects must be included in problem solving. We illustrate the derivation of, and amplify the meaning of, the principles, and discuss mechanisms for their implementation. The principles are: Principle I. Maintenance of healthy populations of wild living resources in perpetuity is inconsistent with unlimited growth of human consumption of and demand for those resources. Principle II. The goal of conservation should be to secure present and future options by maintaining biological diversity at genetic, species, population, and ecosystem levels; as a general rule neither the resource nor other components of the ecosystem should be perturbed beyond natural boundaries of variation. Principle III. Assessment of the possible ecological and sociological effects of resource use should precede both proposed use and proposed restriction or expansion of ongoing use of a resource. Principle IV. Regulation of the use of living resources must be based on understanding the structure and dynamics of the ecosystem of which the resource is a part and must take into account the ecological and sociological influences that directly and indirectly affect resource use. Principle V. The full range of knowledge and skills from the natural and social sciences must be brought to bear on conservation problems. Principle VI. Effective conservation requires understanding and taking account of the motives, interests, and values of all users and stakeholders, but not by simply averaging their positions. Principle VII. Effective conservation requires communication that is interactive, reciprocal, and continuous. Mechanisms for implementation of the principles are discussed. C1 NATL MARINE FISHERIES SERV,SW FISHERIES SCI CTR,LA JOLLA,CA 92038. GEORGE MASON UNIV,PROGRAM GLOBAL CHANGE,FAIRFAX,VA 22030. UNIV PEACE,SAN JOSE,COSTA RICA. YALE UNIV,SCH FORESTRY & ENVIRONM STUDIES,NEW HAVEN,CT 06520. CTR ECOSYST MANAGEMENT STUDIES,WINDEN,GERMANY. LA TROBE UNIV,DEPT GENET & HUMAN VARIAT,BUNDOORA,VIC 3083,AUSTRALIA. UNIV CALIF SAN DIEGO,SCRIPPS INST OCEANOG,LA JOLLA,CA 92093. INT UNION CONSERVAT NAT & NAT RESOURCES,MARINE & COASTAL AREAS PROGRAMME,GLAND,SWITZERLAND. NOAA,NATL MARINE FISHERIES SERV,SEATTLE,WA 98115. COMMISS EUROPEAN COMMUNITIES,INST SYST ENGN & INFORMAT,ISPRA,ITALY. UNIV BERGEN,DEPT FISHERIES & MARINE BIOL,N-5020 BERGEN,NORWAY. MARINE MAMMAL COMMISS,WASHINGTON,DC. PODERE II FALCO,CITTA DELLA PIEVE,ITALY. UNIV BRITISH COLUMBIA,VANCOUVER,BC V5Z 1M9,CANADA. UNIV ICELAND,INST SCI,IS-107 REYKJAVIK,ICELAND. DEPT ENVIRONM & NAT RESOURCES,QUEZON,PHILIPPINES. UNIV GEORGIA,SAVANNAH RIVER ECOL LAB,ATHENS,GA 30602. CTR MARINE CONSERVAT,REDMOND,WA. UNIV ABERDEEN,ABERDEEN AB9 1FX,SCOTLAND. UNIV YORK,DEPT ENVIRONM ECON & ENVIRONM MANAGEMENT,YORK YO1 5DD,N YORKSHIRE,ENGLAND. SIMON FRASER UNIV,SCH RESOURCE & ENVIRONM MANAGEMENT,BURNABY,BC V5A 1S6,CANADA. CHICAGO ZOOL SOC,BROOKFIELD,IL. UNIV TORONTO,INST ENVIRONM STUDIES,TORONTO,ON M5S 1A1,CANADA. ECKERD COLL,ST PETERSBURG,FL 33733. NOAA,NATL MARINE FISHERIES SERV,NE FISHERIES SCI CTR,NARRAGANSETT,RI 02882. NATL MARINE FISHERIES SERV,SILVER SPRING,MD. NATL MARINE FISHERIES SERV,NE FISHERIES SCI CTR,WOODS HOLE,MA 02543. UNIV MINNESOTA,DEPT ECOL EVOLUT & BEHAV,MINNEAPOLIS,MN 55455. LEE TALBOT ASSOCIATES INT,MCLEAN,VA. CALIF FORESTRY ASSOC,SACRAMENTO,CA. UNIV CALIF DAVIS,SECT EVOLUT & ECOL,DAVIS,CA 95616. UNIV CALIF DAVIS,DEPT AGR ECON,DAVIS,CA 95616. FORDHAM UNIV,CALDER CTR,BRONX,NY 10458. WORLD WILDLIFE FUND,WASHINGTON,DC 20037. NAT RESOURCES CONSULTANTS,SEATTLE,WA. RP Mangel, M (reprint author), UNIV CALIF SANTA CRUZ,ENVIRONM STUDIES BOARD,SANTA CRUZ,CA 95064, USA. RI Crozier, Ross/C-6773-2009; Giske, Jarl/A-2402-2010 OI Giske, Jarl/0000-0001-5034-8177 NR 139 TC 160 Z9 166 U1 6 U2 47 PU ECOLOGICAL SOC AMER PI WASHINGTON PA 2010 MASSACHUSETTS AVE, NW, STE 400, WASHINGTON, DC 20036 SN 1051-0761 J9 ECOL APPL JI Ecol. Appl. PD MAY PY 1996 VL 6 IS 2 BP 338 EP 362 DI 10.2307/2269369 PG 25 WC Ecology; Environmental Sciences SC Environmental Sciences & Ecology GA UH485 UT WOS:A1996UH48500002 ER PT J AU MacCall, AD AF MacCall, AD TI Too little, too late: Treating the problem of inaction SO ECOLOGICAL APPLICATIONS LA English DT Article RP MacCall, AD (reprint author), NATL MARINE FISHERIES SERV,SW FISHERIES SCI CTR,TIBURON LAB,TIBURON,CA 94920, USA. NR 1 TC 1 Z9 1 U1 0 U2 1 PU ECOLOGICAL SOC AMER PI WASHINGTON PA 2010 MASSACHUSETTS AVE, NW, STE 400, WASHINGTON, DC 20036 SN 1051-0761 J9 ECOL APPL JI Ecol. Appl. PD MAY PY 1996 VL 6 IS 2 BP 368 EP 369 DI 10.2307/2269373 PG 2 WC Ecology; Environmental Sciences SC Environmental Sciences & Ecology GA UH485 UT WOS:A1996UH48500006 ER PT J AU Jakway, AL Sterling, AM Cundy, VA Cook, CA AF Jakway, AL Sterling, AM Cundy, VA Cook, CA TI Three-dimensional numerical modeling of a field scale rotary kiln incinerator SO ENVIRONMENTAL SCIENCE & TECHNOLOGY LA English DT Article ID LOADED TOLUENE SORBENT AB A steady-state numerical model for the rotary kiln segment of a hazardous waste incinerator is presented. This model builds on work previously conducted at Louisiana State University by including radiation and soot in the heat transfer analysis, by switching to an adiabatic kiln wall boundary condition, and by including a more accurate geometry and better fitting grid. These changes improve agreement with data taken from a field-scale rotary kiln, operating with a natural gas support flame but no waste processing, by up to 2 orders of magnitude compared to previously developed models at LSU, In most instances, prediction is within repeatability limits of the experiments. Grid dependency is demonstrated, especially at the upper front of the kiln where gradients are very steep. Near the exit of the kiln, however, where the limited experimental data are available, both coarse and refined grids produced very similar results. Parametric and sensitivity studies using the developed model are reported. C1 MONTANA STATE UNIV,DEPT MECH & IND ENGN,BOZEMAN,MT 59717. LOUISIANA STATE UNIV,COLL ENGN,BATON ROUGE,LA 70803. NIST,GAITHERSBURG,MD 20899. NR 28 TC 11 Z9 11 U1 2 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 1996 VL 30 IS 5 BP 1699 EP 1712 DI 10.1021/es950709j PG 14 WC Engineering, Environmental; Environmental Sciences SC Engineering; Environmental Sciences & Ecology GA UG954 UT WOS:A1996UG95400066 ER PT J AU Lauth, JR Scott, GI Cherry, DS Buikema, AL AF Lauth, JR Scott, GI Cherry, DS Buikema, AL TI A modular estuarine mesocosm SO ENVIRONMENTAL TOXICOLOGY AND CHEMISTRY LA English DT Article DE azinphosmethyl; mesocosm; estuary; marine; ecotoxicology AB The need to simulate unique features of estuaries and the modes of entry of pollutants has led the authors to develop a modular approach to toxicity testing within an estuarine system. The approach incorporates replicate test systems that simulate the major aspects that are unique to estuarine systems. Initial validation of the design simulated a reference estuary on Wadmalaw Island, South Carolina. Replicate mesocosms were exposed to target concentrations 0, 2, and 8 mu g/L of azinphosmethyl (AZM), an organophosphate insecticide. Single species toxicity tests were conducted within the systems in conjunction with the ecosystem simulations. High doses of AZM killed all animal life in the simulations, whereas lower concentrations showed a dose-response effect. Twenty-four-hour average AZM levels were used to calculate 24-h and 96-h LC50 values for Atlantic silverside minnows (Menidia menidia), mysid shrimp (Mysidopsis bahia), and grass shrimp (Palaemonetes pugio). Mysid shrimp were most sensitive to AZM (96 h LC50 = 0.811 mu g/L), whereas grass shrimp were least sensitive (96 h LC50 = 1.34 mu g/L). Dissolved oxygen was reduced and ammonia concentrations increased from high doses of AZM. Increases in ammonia levels were not reduced by interstitial microbes, resulting in sustained high (>0.08 mg/L) ammonia concentrations. Lower doses were quickly reduced in the mesocosm. This study demonstrates that ecosystem level responses can be evaluated by the modular approach. This modular approach can be modified to simulate most aquatic ecosystems. C1 NATL MARINE FISHERIES SERV,CHARLESTON LAB,CHARLESTON,SC 29412. RP Lauth, JR (reprint author), VIRGINIA TECH,DEPT BIOL,BLACKSBURG,VA 24061, USA. NR 17 TC 27 Z9 28 U1 4 U2 12 PU SETAC PRESS PI PENSACOLA PA 1010 NORTH 12TH AVE, PENSACOLA, FL 32501-3370 SN 0730-7268 J9 ENVIRON TOXICOL CHEM JI Environ. Toxicol. Chem. PD MAY PY 1996 VL 15 IS 5 BP 630 EP 637 DI 10.1897/1551-5028(1996)015<0630:AMEM>2.3.CO;2 PG 8 WC Environmental Sciences; Toxicology SC Environmental Sciences & Ecology; Toxicology GA UH986 UT WOS:A1996UH98600004 ER PT J AU Currin, CA Joye, SB Paerl, HW AF Currin, CA Joye, SB Paerl, HW TI Diel rates of N-2-fixation and denitrification in a transplanted Spartina alterniflora marsh: Implications for N-flux dynamics SO ESTUARINE COASTAL AND SHELF SCIENCE LA English DT Article DE N-cycling; N-2-fixation; denitrification; cyanobacteria; salt marsh; microphytobenthos; diel; USA east coast ID MARINE CYANOBACTERIAL MAT; SALT-MARSH; NITROGEN-FIXATION; OXYGENIC PHOTOSYNTHESIS; MICROBIAL MATS; UNITED-STATES; FRESH-WATER; ECOSYSTEMS; ESTUARINE; PRODUCTIVITY AB Magnitudes and diel patterns of N-2-fixation (acetylene reduction, AR) and potential denitrification (acetylene block technique, DNF) rates were determined in a transplanted Spartina alterniflora marsh. Rates of AR in transplanted marsh surface sediments exceeded rates in an adjacent natural marsh by 5- to 10-fold. In late May, surface sediments from two sites in the transplanted marsh were inhabited by two distinct cyanobacterial communities, each exhibiting a unique diel pattern of AR. Sediments dominated by filamentous, nonheterocystous cyanobacterial species exhibited a nighttime peak in AR, supplying an estimated N input of 50 mg N m(-2) day(-1). Sediments dominated by heterocystous and coccoid cyanobacterial species exhibited a daytime peak in AR and an estimated N input of 145 mg N m(-2) day(-1). In August, surface sediments from five sites in the transplanted marsh were dominated by non-heterocystous cyanobacteria and diatoms. At this time, all sites exhibited a similar diel pattern in AR rates, with a midday minimum and dawn or dusk maxima. The estimated average daily N input was 37 mg N m(-2) day(-1). There was an inverse relationship between hourly AR and CO, fixation (estimated by (CO2)-C-14 uptake) rates, suggesting an inhibitory effect of oxygenic photosynthesis on AR. Oxygen also appeared to inhibit DNF; in May, low DNF rates were noted during the day with higher rates occurring at night. Overall, DNF rates were three orders of magnitude less than N-2-fixation rates; thus, the balance between these processes results in a significant input of N to the transplanted salt marsh. We hypothesize that the reduced vascular plant canopy and coarser sediment characteristic of transplanted marshes may enhance the development and production of benthic microalgal communities dominated by cyanobacteria. Microbially-mediated N-cycling in young, transplanted salt marshes may differ significantly from values recorded from mature, natural salt marshes. (C) 1996 Academic Press Limited C1 UNIV N CAROLINA,INST MARINE SCI,MOREHEAD CITY,NC 28557. TEXAS A&M UNIV,DEPT OCEANOG,COLLEGE STN,TX 77843. RP Currin, CA (reprint author), NOAA,NMFS,BEAUFORT LAB,101 PIVERS ISL RD,BEAUFORT,NC 28516, USA. OI Joye, Samantha/0000-0003-1610-451X NR 63 TC 38 Z9 41 U1 2 U2 8 PU ACADEMIC PRESS LTD PI LONDON PA 24-28 OVAL RD, LONDON, ENGLAND NW1 7DX SN 0272-7714 J9 ESTUAR COAST SHELF S JI Estuar. Coast. Shelf Sci. PD MAY PY 1996 VL 42 IS 5 BP 597 EP 616 DI 10.1006/ecss.1996.0039 PG 20 WC Marine & Freshwater Biology; Oceanography SC Marine & Freshwater Biology; Oceanography GA UJ153 UT WOS:A1996UJ15300005 ER PT J AU Hill, DA Camell, DG Cavcey, KH Koepke, GH AF Hill, DA Camell, DG Cavcey, KH Koepke, GH TI Radiated emissions and immunity of microstrip transmission lines: Theory and reverberation chamber measurements SO IEEE TRANSACTIONS ON ELECTROMAGNETIC COMPATIBILITY LA English DT Article ID PRINTED-CIRCUIT BOARDS AB We analyze radiation from a microstrip transmission line and calculate total radiated power by numerical integration, Reverberation chamber methods for measuring radiated emissions and immunity are reviewed and applied to three microstrip configurations, Measurements from 200 to 2000 MHz are compared with theory, and excellent agreement is obtained for two configurations that minimize feed cable and finite ground plane effects, Emissions measurements are found to be more accurate than immunity measurements because the impedance mismatch of the receiving antenna cancels when the ratio of the microstrip and reference radiated power measurements is taken, The use of two different receiving antenna locations for emissions measurements illustrates good field uniformity within the chamber. RP Hill, DA (reprint author), NATL INST STAND & TECHNOL,DIV ELECTROMAGNET FIELDS,BOULDER,CO 80303, USA. NR 29 TC 44 Z9 46 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 0018-9375 J9 IEEE T ELECTROMAGN C JI IEEE Trans. Electromagn. Compat. PD MAY PY 1996 VL 38 IS 2 BP 165 EP 172 DI 10.1109/15.494619 PG 8 WC Engineering, Electrical & Electronic; Telecommunications SC Engineering; Telecommunications GA UL094 UT WOS:A1996UL09400006 ER PT J AU Trizna, DB Carlson, DJ AF Trizna, DB Carlson, DJ TI Studies of dual polarized low grazing angle radar sea scatter in nearshore regions SO IEEE TRANSACTIONS ON GEOSCIENCE AND REMOTE SENSING LA English DT Article ID SURFACE; SLICKS AB We report on experiments featuring horizontally (HH) and vertically (VV) polarized X-band marine radar sea scatter imagery in the coastal environments of Bermuda and La Jolla, under light to moderate winds and the absence of long gravity waves. These conditions allowed the study of fundamental scattering mechanisms from small scale roughness and short waves of a few meters wavelength or less, shorter than the radar pulse. While a large fraction of radar data collected revealed the presence of slick bands, we analyze here the radar echo of ambient background outside of the slicks. Sea scatter data were digitally recorded for 360 degrees azimuthal coverage for grazing angles between 1-3.5 degrees, and were converted to normalized radar cross section (NRCS or sigma(o)) images. The HH and VV polarizations show quite different spatial texture, with HH exhibiting a discrete character and VV being more nearly spatially homogeneous. Grazing angle dependencies are different for HH and VV: upwind-downwind differences of mean NRCS show ratios of just 4-6 dB for VV, but are equal or greater than the 16-dB noise-imposed limit for HH for the low wind conditions. HH NRCS grazing angle characteristics are shown tb correlate with biological activity indicators of the coastal waters, with a fourth power dependence in relatively unproductive waters, to a nearly quadratic in productive waters. Arguments are presented that suggest different scattering mechanisms for the two polarizations: evenly distributed Bragg scatter patches for VV and scatter from small asymmetric bore features for HH. A multipath illumination model for small bore features is outlined, and scale sizes for the small scale breakers inferred from the experimental results presented here are between 2 and 4 cm in height, with crest widths between 24 and 48 cm. C1 UCAR,NOAA,BOULDER,CO 80301. RP Trizna, DB (reprint author), USN,RES LAB,REMOTE SENSING DIV,WASHINGTON,DC 20375, USA. NR 15 TC 56 Z9 59 U1 1 U2 4 PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017-2394 SN 0196-2892 J9 IEEE T GEOSCI REMOTE JI IEEE Trans. Geosci. Remote Sensing PD MAY PY 1996 VL 34 IS 3 BP 747 EP 757 DI 10.1109/36.499754 PG 11 WC Geochemistry & Geophysics; Engineering, Electrical & Electronic; Remote Sensing; Imaging Science & Photographic Technology SC Geochemistry & Geophysics; Engineering; Remote Sensing; Imaging Science & Photographic Technology GA UM314 UT WOS:A1996UM31400015 ER PT J AU Richards, GP Chao, J Chao, L AF Richards, GP Chao, J Chao, L TI Tissue kallikreins in evolutionarily diverse vertebrates SO IMMUNOPHARMACOLOGY LA English DT Article; Proceedings Paper CT 14th International Symposium on Bradykinin and Related Kinins (KININ 95) CY SEP 10-15, 1995 CL DENVER, CO DE evolution fish; frog; mole; serine proteinase; tissue kallikrein; trypsin AB A search for tissue kallikreins in lower vertebrates resulted in the discovery of three novel kallikreins. Tissue kallikrein was isolated from the salivary gland of the Eastern Atlantic mole, Scalopus aquaticus, and the pancreas of the Southern frog, Rana berlandieri. A prokallikrein was identified in skeletal muscle of the black sea bass, Centropristis striata. These enzymes range in molecular mass from 27 to 36 kDa and are acidic proteins with pIs between 4.2 and 5.3. Bass prokallikrein was activated by trypsin cleavage. These novel kallikreins were compared with human and rat tissue kallikreins in regard to immunoreactivity, molecular weight, isoelectric point, extinction coefficient, susceptibility to serine proteinase inhibitors and their ability to cleave low molecular weight dog kininogen to release kinin peptides. C1 MED UNIV S CAROLINA,DEPT BIOCHEM & MOLEC BIOL,CHARLESTON,SC 29425. NATL MARINE FISHERIES SERV,SE FISHERIES SCI CTR,CHARLESTON LAB,CHARLESTON,SC 29422. FU NHLBI NIH HHS [HL 29397]; NIDCR NIH HHS [DE 09731] NR 3 TC 2 Z9 2 U1 0 U2 0 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0162-3109 J9 IMMUNOPHARMACOLOGY JI Immunopharmacology PD MAY PY 1996 VL 32 IS 1-3 BP 94 EP 95 DI 10.1016/0162-3109(95)00061-5 PG 2 WC Immunology; Pharmacology & Pharmacy SC Immunology; Pharmacology & Pharmacy GA UR643 UT WOS:A1996UR64300023 PM 8796277 ER PT J AU Barnston, AG AF Barnston, AG TI Time-scales of the variability of the atmosphere SO INTERNATIONAL JOURNAL OF CLIMATOLOGY LA English DT Article DE USA; Northern Hemisphere; fast Fourier transform; autocorrelation; temporal variability scales; empirical modelling of variability; surface temperatures; 700 hPa height ID 500-MB HEIGHT FLUCTUATIONS; NORTHERN HEMISPHERE; LONG; PREDICTABILITY; INTERMEDIATE AB In this study the time-scales of variability of several weather elements are explored by season and location across the globe, emphasizing the Northern Hemisphere and especially the USA. The resulting description is useful because regions that exhibit low frequency variability (i.e. longer periods than the 2-5 days synoptic-scale) are assumed to be related more directly to changes in boundary conditions (e.g. anomalies of ENSO-related sea-surface temperature [SST], snow cover, etc.). Therefore, this low frequency variability may be predictable at greater ranges than those for which numerical weather prediction is helpful. New as well as established measures of persistence and frequency dependence are used and intercompared. In particular, the standard deviation of the differences between adjacent period means, when compared over a range of period lengths, reflects both autocorrelation and (if applicable) cycle time. Frequency dependence is thereby summarized with minimal computation. The geographical distribution of the amplitude (amount of variability depends largely on latitude and the upstream geographical environment (i.e. higher latitude and continentality of upstream environment tend to increase variability). At most locations, variability is greatest (lowest) during the cold (warm) seasons of the year. The geographical distribution of the dominant frequencies of variability are examined by season for Northern Hemisphere sea-level pressure and 700 hPa geopotential height, and USA surface temperature and precipitation. It is demonstrated that the dominant frequencies tend to vary in parallel across all four fields. In general, weather variables are found to vary at relatively low frequency (long periods) at high latitudes and, to a lesser extent, at subtropical latitudes. At mid-latitude, low frequency variability prevails most over the blocking regions in the eastern and central North Pacific and North Atlantic oceans. High frequency variability occurs in the synoptically active jet exit regions over the western oceans and the eastern and central parts of the Northern Hemisphere continents. Data from the Atmospheric Model Intercomparison Project integration of the National Centers for Environmental Prediction (formerly National Meteorological Center) medium-range-forecast general circulation model, which reproduce the Northern Hemisphere frequency dependence well at 700 hPa, indicate roughly analogous behaviour in the Southern Hemisphere. However, the longitudinal variation of mid-latitude frequency dependence is substantially less in the Southern Hemisphere, possibly because of the comparative absence of large, topographically significant land masses with favourable separation distance. RP Barnston, AG (reprint author), NOAA,NATL WEATHER SERV,NCEP,CLIMATE PREDICT CTR,WASHINGTON,DC 20233, USA. NR 23 TC 5 Z9 5 U1 1 U2 1 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 PY 1996 VL 16 IS 5 BP 499 EP 535 DI 10.1002/(SICI)1097-0088(199605)16:5<499::AID-JOC22>3.0.CO;2-# PG 37 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA UR647 UT WOS:A1996UR64700002 ER PT J AU Waldron, WK Wineman, A AF Waldron, WK Wineman, A TI Shear and normal stress effects in finite circular shear of a compressible non-linear viscoelastic solid SO INTERNATIONAL JOURNAL OF NON-LINEAR MECHANICS LA English DT Article ID VOLUME CHANGE; YIELD; POLYMERS; BEHAVIOR AB A non-linear single integral constitutive equation is developed for a compressible isotropic viscoelastic solid. Its initial elastic and equilibrium responses are given by the generalized Blatz-Ko model for compressible isotropic non-linear elasticity. A reduced time is introduced which causes stress relaxation to be accelerated by volume change and/or shear deformation. The constitutive equation is used to study circular shear of a hollow cylinder which is bonded to a rigid support at its inner surface and a rigid shell at its outer surface. Two kinds of loading conditions on the shell are investigated, moment control and rotation control. The circular shear causes interior cylindrical surfaces to rotate about the center line and radially expand or contract. The results show the strong influence on the radial distribution and time variation of important physical quantities of two important features of the constitutive equation, the specific form of dependence on the strain tensors and the volume and/or shear dependence of the reduced time. (C) 1996 Elsevier Science Ltd. C1 UNIV MICHIGAN,DEPT MECH ENGN & APPL MECH,ANN ARBOR,MI 48109. RP Waldron, WK (reprint author), NIST,DIV POLYMER,GAITHERSBURG,MD 20899, USA. NR 24 TC 7 Z9 7 U1 0 U2 1 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD, ENGLAND OX5 1GB SN 0020-7462 J9 INT J NONLINEAR MECH JI Int. J. Non-Linear Mech. PD MAY PY 1996 VL 31 IS 3 BP 345 EP 369 DI 10.1016/0020-7462(95)00059-3 PG 25 WC Mechanics SC Mechanics GA UP249 UT WOS:A1996UP24900009 ER PT J AU Laesecke, A Perkins, RA Howley, JB AF Laesecke, A Perkins, RA Howley, JB TI An improved correlation for the thermal conductivity of HCFC123 (2,2-dichloro-1,1,1-trifluoroethane) SO INTERNATIONAL JOURNAL OF REFRIGERATION-REVUE INTERNATIONALE DU FROID LA English DT Article DE refrigerant; substitute; R123; thermal property; thermal conductivity; calculation; accuracy ID HOT-WIRE METHOD; REFRIGERANTS R123; R134A; APPARATUS; FLUIDS; R152A; RANGE; PRESSURES; GASES AB An updated survey of the existing thermal conductivity data for HCFC123 is presented. In addition, new wide-ranging thermal conductivity measurements, which have been carried out at NIST, are summarized. These results supplement the existing database and are used for an improved correlation of the thermal conductivity of HCFC123. The correlation covers the temperature range from 180 to 480 K with pressures up to 67 MPa or densities up to 1900 kg m(-3). The correlation includes an empirical critical enhancement term of a form suitable for industrial use and represents the NIST dataset within +/- 2.22% at the 95% confidence level. RP Laesecke, A (reprint author), NATL INST STAND & TECHNOL,DIV THERMOPHYS,325 BROADWAY,BOULDER,CO 80303, USA. OI Perkins, Richard/0000-0002-8526-6742 NR 34 TC 3 Z9 3 U1 0 U2 1 PU BUTTERWORTH-HEINEMANN LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD, OXON, ENGLAND OX5 1GB SN 0140-7007 J9 INT J REFRIG JI Int. J. Refrig.-Rev. Int. Froid PD MAY PY 1996 VL 19 IS 4 BP 231 EP 238 DI 10.1016/0140-7007(96)00019-9 PG 8 WC Thermodynamics; Engineering, Mechanical SC Thermodynamics; Engineering GA VJ597 UT WOS:A1996VJ59700003 ER PT J AU Defibaugh, DR Gillis, KA Moldover, MR Schmidt, JW Weber, LA AF Defibaugh, DR Gillis, KA Moldover, MR Schmidt, JW Weber, LA TI Thermodynamic properties of CHF2-CF2-CH2F, 1,1,2,2,3-pentafluoropropane SO INTERNATIONAL JOURNAL OF REFRIGERATION-REVUE INTERNATIONALE DU FROID LA English DT Article DE refrigerant; substitute; thermodynamical property; equation of state; calculation; measurement ID VAPOR-PRESSURE; EBULLIOMETRIC MEASUREMENT; SURFACE-TENSION; LIQUID; TEMPERATURE; DENSITIES; EQUATIONS; R141B; STATE; R123 AB We report the thermodynamic properties of 1,1,2,2,3-pentafluoropropane (known in the refrigeration industry as HFC-245ca) in the temperature and pressure region commonly encountered in thermal machinery. The properties are based on measurements of the vapor pressure, the density of the compressed liquid, the refractive index of the saturated liquid and vapor, the critical temperature, the speed of sound in the vapor phase, and the capillary rise. From these data we deduce the saturated liquid and vapor densities, the equation of state of the vapor phase, the surface tension, and estimates of the critical pressure and density. The data determine the coefficients for a Carnahan-Starlings-DeSantis (CSD) equation of state. The CSD coefficients found in REFPROP 4.0 are based on the measurements reported here. RP Defibaugh, DR (reprint author), NIST,CHEM SCI & TECHNOL LAB,DIV THERMOPHYS,GAITHERSBURG,MD 20899, USA. RI Moldover, Michael/E-6384-2013 NR 21 TC 20 Z9 20 U1 0 U2 1 PU BUTTERWORTH-HEINEMANN LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD, OXON, ENGLAND OX5 1GB SN 0140-7007 J9 INT J REFRIG JI Int. J. Refrig.-Rev. Int. Froid PD MAY PY 1996 VL 19 IS 4 BP 285 EP 294 DI 10.1016/0140-7007(95)00086-0 PG 10 WC Thermodynamics; Engineering, Mechanical SC Thermodynamics; Engineering GA VJ597 UT WOS:A1996VJ59700009 ER PT J AU Jia, TD Kelleher, SD Hultin, HO Petillo, D Maney, R Krzynowek, J AF Jia, TD Kelleher, SD Hultin, HO Petillo, D Maney, R Krzynowek, J TI Comparison of quality loss and changes in the glutathione antioxidant system in stored mackerel and bluefish muscle SO JOURNAL OF AGRICULTURAL AND FOOD CHEMISTRY LA English DT Article DE glutathione; antioxidant; mackerel; bluefish; quality loss and antioxidation ID LIPID-PEROXIDATION; FISH AB Minced mackerel muscle was less stable at -20 degrees C than minced bluefish muscle as judged by odor evaluation but not by production of TEA-reactive substances. Minced mackerel muscle lost total glutathione faster than minced bluefish muscle at both -20 and 2 degrees C. Loss of glutathione was also more rapid in mackerel fillets than in bluefish fillets, but the differences were less. Sensory scores declined in both species after about two-thirds of the glutathione was lost. Neither soluble selenium nor glutathione peroxidase, oxidized glutathione reductase, or glutathione transferase activities appeared likely to account for the differences observed in glutathione losses. In a model system of washed, minced mackerel light muscle, glutathione/glutathione peroxidase was an effective antioxidant against lipid oxidation induced by an exogenous free radical-generating system. It seems possible that glutathione protected the fish muscle against quality loss in the early stages of storage. C1 UNIV MASSACHUSETTS,MASSACHUSETTS AGR EXPT STN,DEPT FOOD SCI,MARINE FOODS LAB,MARINE STN,GLOUCESTER,MA 01930. NATL MARINE FISHERIES SERV,NORTHEAST CTR,GLOUCESTER LAB,GLOUCESTER,MA 01930. NR 23 TC 26 Z9 26 U1 0 U2 1 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 MAY PY 1996 VL 44 IS 5 BP 1195 EP 1201 DI 10.1021/jf950767o PG 7 WC Agriculture, Multidisciplinary; Chemistry, Applied; Food Science & Technology SC Agriculture; Chemistry; Food Science & Technology GA UL585 UT WOS:A1996UL58500005 ER PT J AU Marzban, C Stumpf, GJ AF Marzban, C Stumpf, GJ TI A neural network for tornado prediction based on Doppler radar-derived attributes SO JOURNAL OF APPLIED METEOROLOGY LA English DT Article ID SKILL AB The National Severe Storms Laboratory's (NSSL) mesocyclone detection algorithm (MDA) is designed to search for patterns in Doppler velocity radar data that are associated with rotating updrafts in severe thunderstorms. These storm-scale circulations are typically precursors to tornados and severe weather in thunderstorms, yet not all circulations produce such phenomena. A neural network has been designed to diagnose which circulations detected by the NSSL MDA yield tornados. The data used both for the training and the testing of the network are obtained from the NSSL MDA. In particular, 23 variables characterizing the circulations are selected to be used as the input nodes of a feed-forward neural network. The output of the network is chosen to be the existence/nonexistence of tornados, based on ground observations. It is shown that the network outperforms the rule-based algorithm existing in the MDA, as well as statistical techniques such as discriminant analysis and logistic regression. Additionally, a measure of confidence is provided in terms of probability functions. C1 UNIV OKLAHOMA,COOPERAT INST MESOSCALE & METEOROL STUDIES,NORMAN,OK 73019. UNIV OKLAHOMA,DEPT PHYS,NORMAN,OK 73019. RP Marzban, C (reprint author), NATL SEVERE STORMS LAB,1313 HALLEY CIRCLE,NORMAN,OK 73069, USA. NR 21 TC 91 Z9 94 U1 3 U2 6 PU AMER METEOROLOGICAL SOC PI BOSTON PA 45 BEACON ST, BOSTON, MA 02108-3693 SN 0894-8763 J9 J APPL METEOROL JI J. Appl. Meteorol. PD MAY PY 1996 VL 35 IS 5 BP 617 EP 626 DI 10.1175/1520-0450(1996)035<0617:ANNFTP>2.0.CO;2 PG 10 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA UJ387 UT WOS:A1996UJ38700001 ER PT J AU Molenbroek, EC Mahan, AH Johnson, EJ Gallagher, AC AF Molenbroek, EC Mahan, AH Johnson, EJ Gallagher, AC TI Film quality in relation to deposition conditions of a-Si:H films deposited by the ''hot wire'' method using highly diluted silane SO JOURNAL OF APPLIED PHYSICS LA English DT Article ID CHEMICAL VAPOR-DEPOSITION; ABSOLUTE RATE CONSTANTS; SILICON; HYDROGEN; DECOMPOSITION; DISCHARGES AB The deposition parameter space has been extensively explored using the hot wire technique with 1% SiH4 in He as a source gas. To achieve reasonable deposition rates despite the high dilution, the filament was positioned at 1-2 cm from the substrate. This short distance introduced a large nonuniformity across the substrate in deposition rate as well as in film properties. These spatial variations were used to analyze which factors in the deposition determine film quality. Radiation from the filament as well as deposition rate cannot explain the large variation in film properties, leaving gas-phase reactions of Si and H from the hot filament as the primary cause. It is clear that radicals evaporated from the filament must undergo gas-phase reactions with SiH4 before deposition in order to produce high-quality material. Thus, conditions such as increasing the chamber pressure or going to a heavier carrier gas increase the fraction of radicals that can react before reaching the substrate and, therefore, improve the film quality. However, such conditions also enhance multiple radical reactions before such radicals reach the substrate and this can have a negative effect on film quality: this is attributed to gas-phase nucleation with incorporation of conglomerates. The gas-phase chemistry is quite different from that of plasma-enhanced decomposition in that no disilane or trisilane is formed in significant quantities. This, and the dependence on pressure, indicates that the pathway for formation of these heavier particles is radical-radical reactions. (C) 1996 American Institute of Physics. C1 UNIV COLORADO,JOINT INST LAB ASTROPHYS,BOULDER,CO 80309. NATL INST STAND & TECHNOL,BOULDER,CO 80309. RP Molenbroek, EC (reprint author), NATL RENEWABLE ENERGY LAB,GOLDEN,CO 80401, USA. NR 29 TC 34 Z9 34 U1 0 U2 3 PU AMER INST PHYSICS PI MELVILLE PA CIRCULATION & FULFILLMENT DIV, 2 HUNTINGTON QUADRANGLE, STE 1 N O 1, MELVILLE, NY 11747-4501 USA SN 0021-8979 J9 J APPL PHYS JI J. Appl. Phys. PD MAY 1 PY 1996 VL 79 IS 9 BP 7278 EP 7292 DI 10.1063/1.361445 PG 15 WC Physics, Applied SC Physics GA UJ084 UT WOS:A1996UJ08400091 ER PT J AU Defibaugh, DR Morrison, G AF Defibaugh, DR Morrison, G TI Compressed liquid densities, saturated liquid densities, and vapor pressures of 1,1-difluoroethane SO JOURNAL OF CHEMICAL AND ENGINEERING DATA LA English DT Article ID 1,1,1,2-TETRAFLUOROETHANE R-134A; THERMODYNAMIC PROPERTIES; COEXISTENCE CURVE; R-152A AB The compressed liquid densities and vapor pressures of 1,1-difluoroethane (HFC-152a) have been measured, correlated, and compared with other data. The liquid densities were measured with a combined standard uncertainty of +/-0.05% using a vibrating tube densimeter over a temperature range of 243 K to 371 K and at pressures from near the saturated vapor pressure to 6590 kPa; thus the data extend nearly to the critical point (T-c = 386.41 K and P-c = 4514.7 kPa). The vapor pressures were measured with a combined standard uncertainty of +/-0.02% using a stainless steel ebulliometer in the temperature range from 280 K to 335 K. Saturated liquid densities were calculated by extrapolating the compressed liquid isotherms to the saturation pressure. RP Defibaugh, DR (reprint author), NIST,DIV THERMOPHYS,CHEM SCI & TECHNOL LAB,GAITHERSBURG,MD 20899, USA. NR 10 TC 17 Z9 18 U1 0 U2 1 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 MAY-JUN PY 1996 VL 41 IS 3 BP 376 EP 381 DI 10.1021/je9503158 PG 6 WC Thermodynamics; Chemistry, Multidisciplinary; Engineering, Chemical SC Thermodynamics; Chemistry; Engineering GA UL086 UT WOS:A1996UL08600003 ER PT J AU Weber, LA Defibaugh, DR AF Weber, LA Defibaugh, DR TI Vapor pressure of pentafluorodimethyl ether SO JOURNAL OF CHEMICAL AND ENGINEERING DATA LA English DT Article ID LIQUID MOLAR VOLUMES; FLUORINATED ETHERS; C-CF2CF2CF2O; CF3OCF2CF2H; CF3OCF2OCF3; CF3OCH3 AB Vapor pressures of pentafluorodimethyl ether (E125) have been measured from (228 to 331) K using two ebulliometers. Experimental pressures ranged from (65 to 2024) kPa. Thermodynamic calculations were used to estimate pressures down to 140 K (16.5 Pa), and a vapor pressure curve is given which is valid from 140 K to the critical point (354.49 K). The normal boiling temperature was determned to be 238.06 K. The enthalpy of vaporization has been calculated from (140 to 300) K. RP Weber, LA (reprint author), NIST,DIV THERMOPHYS,CHEM SCI & TECHNOL LAB,GAITHERSBURG,MD 20899, USA. NR 10 TC 15 Z9 15 U1 0 U2 3 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 MAY-JUN PY 1996 VL 41 IS 3 BP 382 EP 385 DI 10.1021/je950217m PG 4 WC Thermodynamics; Chemistry, Multidisciplinary; Engineering, Chemical SC Thermodynamics; Chemistry; Engineering GA UL086 UT WOS:A1996UL08600004 ER PT J AU Archer, DG Filer, D Oakley, E Cotts, EJ AF Archer, DG Filer, D Oakley, E Cotts, EJ TI Enthalpy increment measurements from 4.5 K to 350 K and the thermodynamic properties of the titanium silicide Ti5Si3(Cr) SO JOURNAL OF CHEMICAL AND ENGINEERING DATA LA English DT Article AB Enthalpy increments for Ti5Si3(cr) were measured from 4.5 K to 350 K with an adiabatic calorimeter. From a representation of these measurements the enthalpy relative to 0 K, the entropy, and the heat capacity of Ti5Si3(cr) to 350 K were calculated. Values of the Debye temperature, Theta(D), and the coefficient for the heat capacity of the conduction electrons, gamma(el), were determined from the model. Thermodynamic properties for formation from the elements at 298.15 K were also given. Our previous value of Theta(D) for TiSi2 was revised due to improvement in the method of representation. C1 SUNY BINGHAMTON,DEPT PHYS,BINGHAMTON,NY 13902. RP Archer, DG (reprint author), NIST,DIV CHEM KINET & THERMODYNAM,GAITHERSBURG,MD 20899, USA. NR 13 TC 5 Z9 5 U1 0 U2 0 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 MAY-JUN PY 1996 VL 41 IS 3 BP 571 EP 575 DI 10.1021/je950288l PG 5 WC Thermodynamics; Chemistry, Multidisciplinary; Engineering, Chemical SC Thermodynamics; Chemistry; Engineering GA UL086 UT WOS:A1996UL08600046 ER PT J AU Mathew, M AF Mathew, M TI Crystal structure of a highly hydrated tristrontium phosphate, Sr-9(PO4)(6)center dot 16H(2)O SO JOURNAL OF CHEMICAL CRYSTALLOGRAPHY LA English DT Article DE crystal structure; hydrated phosphate; layer-type structure; strontium phosphate; strontium phosphate hydrate AB The crystal structure of a highly hydrated tristrontium phosphate, nonastrontium hexakis(phosphate) hexadecahydrate, Sr-9(PO4)(6) . 16H(2)O, has been determined by single crystal X-ray diffraction. The crystals are monoclinic, a = 15.203(2), b = 6.488(1), c = 18.984(7) Angstrom, beta = 98.42(2)degrees, space group P2/c (No. 13), Z = 2, V = 1852.3 Angstrom(3), d(c) = 2.951 Mg . m(-3). The structure was refined by full-matrix least-squares techniques to R = 0.038, R(w) = 0.051, for 2329 reflections with I greater than or equal to 3 sigma(I). The structure can be described in terms of a layer-type arrangement parallel to (100). One layer consists of a compact assembly of columns of Sr and PO4 ions in a pseudohexagonal arrangement resembling an apatitic structure. A second layer containing all the water molecules and one PO4 ion that occupies the interstitial space may be referred to as the hydrated layer. The structure has an overall similarity to that of octacalcium phosphate and can be considered as a model for amorphous calcium phosphate. RP Mathew, M (reprint author), NATL INST STAND & TECHNOL,AMER DENT ASSOC HLTH FDN,PAFFENBARGER RES CTR,GAITHERSBURG,MD 20899, USA. RI G, Neela/H-3016-2014 NR 16 TC 1 Z9 1 U1 0 U2 5 PU PLENUM PUBL CORP PI NEW YORK PA 233 SPRING ST, NEW YORK, NY 10013 SN 1074-1542 J9 J CHEM CRYSTALLOGR JI J. Chem. Crystallogr. PD MAY PY 1996 VL 26 IS 5 BP 341 EP 346 DI 10.1007/BF01677098 PG 6 WC Crystallography; Spectroscopy SC Crystallography; Spectroscopy GA VA932 UT WOS:A1996VA93200005 ER PT J AU OHare, PAG Zywocinski, A Curtiss, LA AF OHare, PAG Zywocinski, A Curtiss, LA TI Thermodynamics of (germanium plus selenium): A review and critical assessment SO JOURNAL OF CHEMICAL THERMODYNAMICS LA English DT Review ID STANDARD MOLAR ENTHALPIES; DISSOCIATION ENTHALPIES; KNUDSEN MEASUREMENTS; GESE2; SE; SUBLIMATION; CALORIMETRY; ENERGIES; HEAT; CRYSTALLINE AB This review deals with the critical assessment of the thermodynamic properties of several germanium selenides: GeSe(cr), GeSe(g), GeSe2(cr), GeSe2(g), and Ge2Se2(g). In the absence of experimental information, the structures, internuclear distances, and vibrational wavenumbers were calculated for GeSe2(g) and Ge2Se2(g) by molecular orbital methods. The triatomic GeSue(2)(g) is linear. The tetratomic selenide has a butterfly-shaped structure, with alternating Ge and Se atoms, akin to Ge2S2(g), but the interplanar angle, close to 0.78 .pi, is smaller than in the sulfur-containing analog. Statistical mechanical methods were used to calculate the conventional molar thermodynamic functions {C(pm)degrees(T), Delta(0)(T)S(m) degrees, Delta(T)(T) H-m degrees, and Phi(m) degrees(T)} of GeSe, GeSe2, and Ge2Se2 in the ideal gas state at a pressure p degrees = 101.325 kPa with T' = 298.15 K. Heat capacities of solid GeSe and GeSe2 reported in the literature were re-evaluated from T --> 0 to the melting temperatures. The enthalpy of sublimation Delta(sub)H(m) degrees(GeSe,298.15 K) is selected as (172.7 +/- 1.0) kJ . mol(-1) on the basis of a third-law evaluation of published vapor pressure measurements. A similar treatment yielded Delta(r)H(m) degrees(298.15 K) = (295.8 +/- 1.0) kJ . mol(-1) for the reaction: GeSe2(cr) = GeSe(g) + (1/2)Se-2(g). For dissociation of Ge-Se bonds, enthalpies D-m degrees, and mean enthalpies [D-m degrees], were calculated to be: D-m degrees(GeSe) = (480.6 +/- 1.7) kJ . mol(-1) at T --> 0; [D-m degrees](GeSe2) = (364 +/- 9) kJ . mol(-1), and [D-m degrees](Ge2Se2) = (270 +/- 2) kJ . mol(-1), both at T = 298.15 K. The trend in values of enthalpies of dissociation parallels the nominal bond orders. (C) 1996 Academic Press Limited C1 POLISH ACAD SCI,INST PHYS CHEM,WARSAW,POLAND. ARGONNE NATL LAB,DIV CHEM TECHNOL,ARGONNE,IL 60439. RP OHare, PAG (reprint author), NIST,DIV CHEM KINET & THERMODYNAM,GAITHERSBURG,MD 20899, USA. NR 54 TC 8 Z9 8 U1 2 U2 17 PU ACADEMIC PRESS LTD PI LONDON PA 24-28 OVAL RD, LONDON, ENGLAND NW1 7DX SN 0021-9614 J9 J CHEM THERMODYN JI J. Chem. Thermodyn. PD MAY PY 1996 VL 28 IS 5 BP 459 EP 480 DI 10.1006/jcht.1996.0045 PG 22 WC Thermodynamics; Chemistry, Physical SC Thermodynamics; Chemistry GA UV377 UT WOS:A1996UV37700001 ER PT J AU Ropelewski, CF Halpert, MS AF Ropelewski, CF Halpert, MS TI Quantifying Southern Oscillation - Precipitation relationships SO JOURNAL OF CLIMATE LA English DT Article ID SEASONAL RAINFALL ANOMALIES; SUMMER MONSOON RAINFALL; EQUATORIAL PACIFIC; SURFACE CLIMATE; PATTERNS; INDIA; PREDICTION; VARIABILITY; STREAMFLOW; AMERICA AB A series of earlier studies has identified regions of the world in which precipitation appears to have a consistent relationship with the Southern Oscillation (SO). In this paper, the authors attempt to quantify this relationship based on shifts in the statistical distribution of precipitation amounts with emphasis on shifts in the median, which are associated with the warm (low SO index) and cold (high SQ index) phases of the SO. This paper is partially an attempt to provide long-range forecasters with some guidance in making seasonal and multiseasonal predictions. Observed SO-related shifts in the median precipitation amounts, expressed as percentiles with respect to ''climatological'' conditions, can be used as a simple indication of the ''typical'' SO response for a given region. In general, the authors find that for many of the large areas identified in previous studies, median precipitation amounts shift on the order of 20 percentile points, that is, from the median to either the 30th percentile or the 70th percentile. The authors also find considerable spatial variations in the typical patterns of SO-related precipitation percentiles in some regions. This study also provides empirically based estimates of SO-related precipitation anomalies in terms of precipitation rates for use in numerical model studies. For selected areas in the Tropics, the authors find empirically estimated anomalous precipitation rates ranging from 1 to 3.5 mm/day, that is, from 15% to 83% of the climatological median. RP Ropelewski, CF (reprint author), NOAA,NATL WEATHER SERV,NCEP,CLIMATE PREDICT CTR,WASHINGTON,DC 20233, USA. NR 39 TC 362 Z9 377 U1 1 U2 20 PU AMER METEOROLOGICAL SOC PI BOSTON PA 45 BEACON ST, BOSTON, MA 02108-3693 SN 0894-8755 J9 J CLIMATE JI J. Clim. PD MAY PY 1996 VL 9 IS 5 BP 1043 EP 1059 DI 10.1175/1520-0442(1996)009<1043:QSOPR>2.0.CO;2 PG 17 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA UN856 UT WOS:A1996UN85600010 ER PT J AU Gullikson, EM Korde, R Canfield, LR Vest, RE AF Gullikson, EM Korde, R Canfield, LR Vest, RE TI Stable silicon photodiodes for absolute intensity measurements in the VUV and soft x-ray regions SO JOURNAL OF ELECTRON SPECTROSCOPY AND RELATED PHENOMENA LA English DT Article; Proceedings Paper CT 11th International Conference on Vacuum Ultraviolet Radiation Physics (VUV-11 Conference) CY AUG 27-SEP 01, 1995 CL RIKKYO UNIV, TOKYO, JAPAN SP Phys Soc Japan, Chem Soc Japan, Japanese Soc Appl Phys, Spectroscop Soc Japan, Biophys Soc Japan, Vacuum Soc Japan, Japan Soc Promot Sci, Federat Econ Org, Commemorat Assoc Japan World Exposit 1970, JAERI RIKEN Spring 9 Project Team, Unoue Fdn Sci, Ciba Geigy Fdn Japan Promot Sci, Murata Sci Fdn, Asahi Glass Fdn, Shimadzu Sci Fdn, Watanabe Mem Fdn Adv Technol, Nippon Sheet Glass Fdn Mat Sci & Engn, Osaka Sci & Technol Ctr HO RIKKYO UNIV ID ULTRAVIOLET; SCATTERING; STABILITY AB Stable silicon photodiodes with 100% internal quantum efficiency have been developed for the vacuum ultraviolet and soft x-ray regions. It is demonstrated that the response of these detectors can be reasonably well represented by a simple model for photon energies above 40 eV. The measured efficiency is consistent with a constant electron-hole pair creation energy for Si above 40 eV. Radiation damage is demonstrated to result in loss of carriers to recombination at the front surface. The uniformity of the diodes is shown to be better than 0.1% RMS at 110 eV. C1 INT RADIAT DETECTORS, TORRANCE, CA 90505 USA. NIST, PHYS LAB, GAITHERSBURG, MD 20899 USA. RP Gullikson, EM (reprint author), LAWRENCE BERKELEY LAB, DIV SCI MAT, CTR XRAY OPT, BERKELEY, CA 94720 USA. NR 11 TC 107 Z9 111 U1 0 U2 8 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0368-2048 J9 J ELECTRON SPECTROSC JI J. Electron Spectrosc. Relat. Phenom. PD MAY PY 1996 VL 80 BP 313 EP 316 DI 10.1016/0368-2048(96)02983-0 PG 4 WC Spectroscopy SC Spectroscopy GA VA962 UT WOS:A1996VA96200076 ER PT J AU Morgan, HD Seyoum, HM Fortna, JDE Furst, ML AF Morgan, HD Seyoum, HM Fortna, JDE Furst, ML TI High resolution vuv photo-absorption cross sections of O-2 near 83.4 nm. SO JOURNAL OF ELECTRON SPECTROSCOPY AND RELATED PHENOMENA LA English DT Article; Proceedings Paper CT 11th International Conference on Vacuum Ultraviolet Radiation Physics (VUV-11 Conference) CY AUG 27-SEP 01, 1995 CL RIKKYO UNIV, TOKYO, JAPAN SP Phys Soc Japan, Chem Soc Japan, Japanese Soc Appl Phys, Spectroscop Soc Japan, Biophys Soc Japan, Vacuum Soc Japan, Japan Soc Promot Sci, Federat Econ Org, Commemorat Assoc Japan World Exposit 1970, JAERI RIKEN Spring 9 Project Team, Unoue Fdn Sci, Ciba Geigy Fdn Japan Promot Sci, Murata Sci Fdn, Asahi Glass Fdn, Shimadzu Sci Fdn, Watanabe Mem Fdn Adv Technol, Nippon Sheet Glass Fdn Mat Sci & Engn, Osaka Sci & Technol Ctr HO RIKKYO UNIV AB The O+ (2s2p(4 4)P-->2s(2)2p(3 4)S(o)) 83.4 nm triplet is of great interest in ionosphere physics primarily for its role in remote sensing of the ionosphere. Absolute photoabsorption cross sections of O-2 near 83.4 nm have been made utilizing the Very High Resolution Spectrometer at the National Institute of Standards and Technology's Synchrotron Ultraviolet Radiation Facility (SURF II). The 6.65 m spectrometer has a resolving power of similar to 100,000 near 80 nm (FWHM = 0.8 pm). Cross sections were measured over the range 83.0 - 83.5 nm. The value of the cross sections at the positions of the triplet emission lines located at 83.4465, 83.3329, and 83.2757 nm are 14.4 +/- 0.7, 18.4 +/- 0.8, and 38.2 +/- 1.5 Mb respectively. The cross section at the peak of the absorption band at 83.268 nm is 40.6 +/- 1.6 Mb. The large discrepancies between our values and those of other investigators are probably due to their low instrumental resolution. C1 NATL INST STAND & TECHNOL,DIV ELECTRON & OPT PHYS,GAITHERSBURG,MD 20899. RP Morgan, HD (reprint author), UNIV DIST COLUMBIA,DEPT PHYS,4200 CONNECTICUT AVE NW,WASHINGTON,DC 20008, USA. NR 12 TC 4 Z9 5 U1 1 U2 1 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0368-2048 J9 J ELECTRON SPECTROSC JI J. Electron Spectrosc. Relat. Phenom. PD MAY PY 1996 VL 79 BP 387 EP 390 DI 10.1016/0368-2048(96)02878-2 PG 4 WC Spectroscopy SC Spectroscopy GA UY743 UT WOS:A1996UY74300091 ER PT J AU West, JB Parr, AC Hayes, MA Dehmer, JL Dehmer, PM Ueda, K Siggel, MRF Hardis, JE AF West, JB Parr, AC Hayes, MA Dehmer, JL Dehmer, PM Ueda, K Siggel, MRF Hardis, JE TI A high resolution study of the photelectron angular distributions and branching ratios for the carbon dioxide molecule in the wavelength region 685-795 angstrom SO JOURNAL OF ELECTRON SPECTROSCOPY AND RELATED PHENOMENA LA English DT Article; Proceedings Paper CT 11th International Conference on Vacuum Ultraviolet Radiation Physics (VUV-11 Conference) CY AUG 27-SEP 01, 1995 CL RIKKYO UNIV, TOKYO, JAPAN SP Phys Soc Japan, Chem Soc Japan, Japanese Soc Appl Phys, Spectroscop Soc Japan, Biophys Soc Japan, Vacuum Soc Japan, Japan Soc Promot Sci, Federat Econ Org, Commemorat Assoc Japan World Exposit 1970, JAERI RIKEN Spring 9 Project Team, Unoue Fdn Sci, Ciba Geigy Fdn Japan Promot Sci, Murata Sci Fdn, Asahi Glass Fdn, Shimadzu Sci Fdn, Watanabe Mem Fdn Adv Technol, Nippon Sheet Glass Fdn Mat Sci & Engn, Osaka Sci & Technol Ctr HO RIKKYO UNIV ID PARAMETERS; CO2 AB Measurements of the vibrational branching ratios and photoelectron angular distributions have been made in the regions of the Tanaka-Ogawa, Lindholm and Henning series for the CO2 molecule. The behaviour of these parameters was found to be sensitive to which particular resonance is excited, with considerable intensity going into vibrational modes other than the symmetric st-retch. An initial analysis of some of the data taken is presented. C1 NATL INST STAND & TECHNOL,GAITHERSBURG,MD 20899. ARGONNE NATL LAB,DIV ENVIRONM RES,ARGONNE,IL 60439. TOHOKU UNIV,SCI MEASUREMENTS RES INST,SENDAI,MIYAGI 980,JAPAN. RP West, JB (reprint author), SERC,DARESBURY LAB,WARRINGTON WA4 4AD,CHESHIRE,ENGLAND. NR 11 TC 2 Z9 2 U1 0 U2 1 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0368-2048 J9 J ELECTRON SPECTROSC JI J. Electron Spectrosc. Relat. Phenom. PD MAY PY 1996 VL 79 BP 511 EP 514 DI 10.1016/0368-2048(96)02907-6 PG 4 WC Spectroscopy SC Spectroscopy GA UY743 UT WOS:A1996UY74300120 ER PT J AU Gardner, J Rao, MV Holland, OW Kelner, G Simons, DS Chi, PH Andrews, JM Kretchmer, J Ghezzo, M AF Gardner, J Rao, MV Holland, OW Kelner, G Simons, DS Chi, PH Andrews, JM Kretchmer, J Ghezzo, M TI Elevated temperature nitrogen implants in 6H-SiC SO JOURNAL OF ELECTRONIC MATERIALS LA English DT Article; Proceedings Paper CT Electronic Materials Conference CY JUN 21-23, 1995 CL CHARLOTTESVILLE, VA DE electrical activation; ion implantation; nitrogen; p-n junction diode; secondary ion mass spectrometry; silicon carbide ID BETA SILICON-CARBIDE; ELECTRICAL-PROPERTIES; JUNCTION DIODES AB Elevated temperature (700 degrees C)N ion implantations were performed into 6H-SiC in the energy range of 50 keV-4 MeV. By analyzing the as-implanted depth distributions, the range statistics of the N+ in 6H-SiC have been established over this energy range. Annealing at 1500 and 1600 degrees C for 15 min resulted in Rutherford backscattering spectrometry scattering yields at the virgin crystal level, indicating a good recovery of the crystalline quality of the material without any redistribution of the dopant. A maximum electron concentration of 2 x 10(19) cm(-3), at room temperature, has been measured even for high-dose implants. The p-n junction diodes made by N ion implantation into a p-type substrate have a forward turn-on voltage of 2.2 V, an ideality factor of 1.90, and a reverse breakdown voltage of 125 V with nA range leakage current for -10 V bias at room temperature. By probing many devices on the same substrate we found uniform forward and reverse characteristics across the crystal. C1 OAK RIDGE NATL LAB,OAK RIDGE,TN 37831. USN,RES LAB,WASHINGTON,DC 20375. NIST,GAITHERSBURG,MD 20899. NANTRON ASSOCIATES,ALEXANDRIA,VA 22306. GE CO,CORP RES & DEV,SCHENECTADY,NY 12301. RP Gardner, J (reprint author), GEORGE MASON UNIV,DEPT ELECT & COMP ENGN,FAIRFAX,VA 22030, USA. NR 32 TC 23 Z9 23 U1 0 U2 1 PU MINERALS METALS MATERIALS SOC PI WARRENDALE PA 420 COMMONWEALTH DR, WARRENDALE, PA 15086 SN 0361-5235 J9 J ELECTRON MATER JI J. Electron. Mater. PD MAY PY 1996 VL 25 IS 5 BP 885 EP 892 PG 8 WC Engineering, Electrical & Electronic; Materials Science, Multidisciplinary; Physics, Applied SC Engineering; Materials Science; Physics GA UJ099 UT WOS:A1996UJ09900020 ER PT J AU Huang, H Fergen, RE Proni, JR Tsai, JJ AF Huang, H Fergen, RE Proni, JR Tsai, JJ TI Probabilistic analysis of ocean outfall mixing zones SO JOURNAL OF ENVIRONMENTAL ENGINEERING-ASCE LA English DT Article ID DILUTION; PLUMES; JETS AB A methodology for ocean outfall mixing zone analysis is presented. It is based on a combination of four deterministic models for predicting hydrodynamic mixing behaviors of the discharged effluent, a continuous time domain simulation method, and an exceedance probability field concept. The approach provides a framework for evaluating mixing zones in compliance with receiving water criteria that are set in statistical terms. The approach was applied to the Hollywood outfall located off the east coast of South Florida. An exceedance probability field for effluent at a specified relative concentration of 0.021 was created. This field was applicable for determining the exceedance probability-based concentrations of any conservative pollutant at the regulatory mixing zone edge. A comparison of the probabilistic approach with the worst-case approach was made. The use of the worst-case approach was found to be too conservative for the subject outfall. C1 NOAA,ATLANTIC OCEANOG & METEOROL LAB,OCEAN ACOUST DIV,MIAMI,FL 33149. RP Huang, H (reprint author), HAZEN & SAWYER PC,4011 WESTCHASE BLVD,RALEIGH,NC 27607, USA. NR 26 TC 10 Z9 11 U1 0 U2 0 PU ASCE-AMER SOC CIVIL ENG PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017-2398 SN 0733-9372 J9 J ENVIRON ENG-ASCE JI J. Environ. Eng.-ASCE PD MAY PY 1996 VL 122 IS 5 BP 359 EP 367 DI 10.1061/(ASCE)0733-9372(1996)122:5(359) PG 9 WC Engineering, Environmental; Engineering, Civil; Environmental Sciences SC Engineering; Environmental Sciences & Ecology GA UG902 UT WOS:A1996UG90200005 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 80302, 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 MAY 1 PY 1996 VL 101 IS A5 BP 10835 EP 10837 DI 10.1029/96JA01112 PG 3 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA UJ412 UT WOS:A1996UJ41200030 ER PT J AU Ramirez, JA Finnerty, B AF Ramirez, JA Finnerty, B TI CO2 and temperature effects on evapotranspiration and irrigated agriculture SO JOURNAL OF IRRIGATION AND DRAINAGE ENGINEERING-ASCE LA English DT Article ID CARBON-DIOXIDE; WATER-USE; CLIMATIC CHANGES; ATMOSPHERIC CO2; YIELD; PLANT; RADIATION; GROWTH; MODEL; BASIN AB A sensitivity analysis of potential evapotranspiration (PET) rates under both CO2 and air temperature changes was conducted. PET was modeled with the Penman-Monteith equation so that the effects of atmospheric CO2 concentrations on plant stomatal resistance, and the effects of temperature on land-surface-atmosphere water vapor exchanges were explicitly taken into account. A root-zone soil-water balance was performed using a physically based soil-crop-climate model to analyze the sensitivity of soil moisture to changes in atmospheric temperature and CO2 concentrations, and the effects of CO2 fertilization on plant photosynthesis and crop yield. A wide spectrum of directional climate change scenarios were analyzed, including both a 3 degrees C increase and a 3 degrees C decrease in air temperature, and both a 50 and a 100% increase in atmospheric CO2 concentrations. An additive crop yield model and an optimal irrigation scheduling model were used to maximize agricultural benefits by maximizing crop yield and minimizing irrigation costs. The model was applied to an irrigated potato crop in the San Luis Valley of Colorado. C1 NOAA,NATL WEATHER SERV,OFF HYDRO,SILVER SPRING,MD 20910. RP Ramirez, JA (reprint author), COLORADO STATE UNIV,DEPT CIVIL ENGN,HYDROL SCI & ENGN PROGRAM,FT COLLINS,CO 80523, USA. NR 55 TC 20 Z9 21 U1 1 U2 4 PU ASCE-AMER SOC CIVIL ENG PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017-2398 SN 0733-9437 J9 J IRRIG DRAIN E-ASCE JI J. Irrig. Drainage Eng-ASCE PD MAY-JUN PY 1996 VL 122 IS 3 BP 155 EP 163 PG 9 WC Agricultural Engineering; Engineering, Civil; Water Resources SC Agriculture; Engineering; Water Resources GA UM563 UT WOS:A1996UM56300004 ER PT J AU Ramirez, JA Finnerty, B AF Ramirez, JA Finnerty, B TI Precipitation and water-table effects on agricultural production and economics SO JOURNAL OF IRRIGATION AND DRAINAGE ENGINEERING-ASCE LA English DT Article ID IRRIGATION; CLIMATE AB The sensitivity of irrigated agriculture to water-table fluctuations and agroeconomic parameters was analyzed in the context of long-term climatic variability. Capillary rise was modeled as a function of soil moisture content and depth to the water table. The capillary rise model was used to define the sensitivity of soil moisture depletion, actual evapotranspiration, and agricultural benefits to changes in water-table depth. Water-table fluctuations had a pronounced effect on root-zone soil moisture, irrigation water use requirements, and agricultural benefits. An economic analysis was performed to determine the sensitivity of site-specific irrigated potato production in the San Luis Valley given the potential changes in available irrigation water supply and agroeconomic parameters. Agricultural benefits were found to be highly sensitive to production costs variations, to deviations of crop market prices from their mean values, and to available irrigation water supply. C1 NOAA,NATL WEATHER SERV,SILVER SPRING,MD 20910. RP Ramirez, JA (reprint author), COLORADO STATE UNIV,DEPT CIVIL ENGN,HYDROL SCI & ENGN PROGRAM,FT COLLINS,CO 80523, USA. NR 26 TC 5 Z9 5 U1 0 U2 1 PU ASCE-AMER SOC CIVIL ENG PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017-2398 SN 0733-9437 J9 J IRRIG DRAIN E-ASCE JI J. Irrig. Drainage Eng-ASCE PD MAY-JUN PY 1996 VL 122 IS 3 BP 164 EP 171 PG 8 WC Agricultural Engineering; Engineering, Civil; Water Resources SC Agriculture; Engineering; Water Resources GA UM563 UT WOS:A1996UM56300005 ER PT J AU Song, JF Vorburger, TV AF Song, JF Vorburger, TV TI Stylus flight in surface profiling SO JOURNAL OF MANUFACTURING SCIENCE AND ENGINEERING-TRANSACTIONS OF THE ASME LA English DT Article ID MICROSCOPY; SPECIMENS; FORCE AB In this paper, theoretical and experimental work on stylus flight is described. Experiments on the surfaces of different roughness specimens with sinusoidal, rectangular, triangular and random waveforms support the theoretical model, which predicts stylus flight from the traversing speed, stylus force, stylus radius and parameters of the surface. RP Song, JF (reprint author), NATL INST STAND & TECHNOL,GAITHERSBURG,MD 20899, USA. NR 23 TC 1 Z9 1 U1 0 U2 11 PU ASME-AMER SOC MECHANICAL ENG PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 SN 1087-1357 J9 J MANUF SCI E-T ASME JI J. Manuf. Sci. Eng.-Trans. ASME PD MAY PY 1996 VL 118 IS 2 BP 188 EP 198 DI 10.1115/1.2831011 PG 11 WC Engineering, Manufacturing; Engineering, Mechanical SC Engineering GA VA694 UT WOS:A1996VA69400003 ER PT J AU Li, XJ Chang, P Pacanowski, RC AF Li, XJ Chang, P Pacanowski, RC TI A wave-induced stirring mechanism in the mid-depth equatorial ocean SO JOURNAL OF MARINE RESEARCH LA English DT Article ID RESIDUAL CURRENTS; ATLANTIC; MODEL; PROPAGATION; DISPERSION; PACIFIC; FLOWS AB A wave-induced stirring and transport mechanism for the mid-depth equatorial ocean is proposed and examined using both analytic linear equatorial wave solutions and a fully nonlinear reduced-gravity model. The study of kinematic stirring using the linear solutions suggests that a superimposition of a few simple equatorial waves can lead to strong Lagrangian stirring and transport along the equator. In particular, a combination of an annual long Rossby wave and a high-frequency Yanai wave appears to be most effective in producing strong stirring in the interior equatorial region. Further investigations of stirring properties using an inverted, fully nonlinear reduced gravity shallow-water model support the results of the kinematic stirring study. By evaluating the finite-time estimates of Lyapunov exponents, we identified two regions where chaotic stirring is most active. One is the western boundary region where short Rossby waves likely play a dominant role in producing the strong chaotic stirring. The other is the equatorial waveguide where a low-frequency Rossby wave prescribes the pattern of the stirring geometry, and a high-frequency Yanai wave plays a role of stirring the fluid. The proposed stirring mechanism provides a plausible explanation of the observed chlorofluorocarbon distribution found in the mid-depth equatorial Atlantic Ocean. C1 PRINCETON UNIV,NOAA,GEOPHYS FLUID DYNAM LAB,PRINCETON,NJ 08542. RP Li, XJ (reprint author), TEXAS A&M UNIV,DEPT OCEANOG,COLLEGE STN,TX 77843, USA. RI Chang, Ping /A-1642-2013 OI Chang, Ping /0000-0002-9085-0759 NR 47 TC 13 Z9 13 U1 0 U2 2 PU KLINE GEOLOGY LABORATORY PI NEW HAVEN PA YALE UNIV, NEW HAVEN, CT 06520 SN 0022-2402 J9 J MAR RES JI J. Mar. Res. PD MAY PY 1996 VL 54 IS 3 BP 487 EP 520 DI 10.1357/0022240963213556 PG 34 WC Oceanography SC Oceanography GA UN282 UT WOS:A1996UN28200005 ER PT J AU Guelachvili, G Birk, M Borde, CJ Brault, JW Brown, LR Carli, B Cole, ARH Evenson, KM Fayt, A Hausamann, D Johns, JWC Kauppinen, J Kou, Q Maki, AG Rao, KN Toth, RA Urban, W Valentin, A Verges, J Wagner, G Wappelhorst, MH Wells, JS Winnewisse, BP Winnewisser, M AF Guelachvili, G Birk, M Borde, CJ Brault, JW Brown, LR Carli, B Cole, ARH Evenson, KM Fayt, A Hausamann, D Johns, JWC Kauppinen, J Kou, Q Maki, AG Rao, KN Toth, RA Urban, W Valentin, A Verges, J Wagner, G Wappelhorst, MH Wells, JS Winnewisse, BP Winnewisser, M TI High resolution wavenumber standards for the infrared - Technical report SO JOURNAL OF MOLECULAR SPECTROSCOPY LA English DT Article ID HETERODYNE FREQUENCY MEASUREMENTS; (CO)-C-12-O-16 LASER TRANSITIONS; ACCURATE ROTATIONAL-CONSTANTS; CARBONYL SULFIDE; LINE POSITIONS; MOLECULAR-CONSTANTS; MU-M; CALIBRATION TABLES; FUNDAMENTAL-BAND; DIODE-LASER AB The calibration of high resolution infrared spectra is generally more precise than accurate. This is the case even when they are recorded with Fourier transform interferometers. The present document aims at improving the accuracy of wavenumber measurements in the infrared by recommending a selection of spectral lines as wavenumber standards for absolute calibration in the range from about 4 to about 7000 cm(-1). The uncertainties of these wavenumber standards range from 4+/-1x10(-3) to +/-1x10(-6) cm(-1). Sources of frequency standards, on which the wavenumber determinations are based, are also given. C1 DLR,INST OPTOELECTR,D-82234 WESSELING,GERMANY. UNIV PARIS 13,PHYS LASERS LAB,F-93430 VILLETANEUSE,FRANCE. CALTECH,JET PROP LAB,PASADENA,CA 91109. CNR,IST RIC ONDE ELETTROMAGNET,I-50127 FLORENCE,ITALY. UNIV WESTERN AUSTRALIA,SCH CHEM,NEDLANDS,WA 6009,AUSTRALIA. NATL INST STAND & TECHNOL,DIV TIME & FREQUENCY,BOULDER,CO 80303. UNIV CATHOLIQUE LOUVAIN,MOLEC SPECT LAB,B-1348 LOUVAIN,BELGIUM. NATL RES COUNCIL CANADA,STEACIE INST MOLEC SCI,OTTAWA,ON K1A 0R6,CANADA. UNIV TURKU,DEPT APPL PHYS,FIN-20500 TURKU,FINLAND. UNIV WASHINGTON,DEPT CHEM,SEATTLE,WA 98195. OHIO STATE UNIV,DEPT PHYS,COLUMBUS,OH 43210. UNIV BONN,INST ANGEW PHYS,D-53115 BONN,GERMANY. UNIV PARIS 06,CNRS UPR 136,PHYS MOLEC LAB,F-75252 PARIS 05,FRANCE. LAB AIMEE COTTON,F-91405 ORSAY,FRANCE. UNIV GIESSEN,INST PHYS CHEM,D-35392 GIESSEN,GERMANY. NOAA,AERON LAB REAL5,BOULDER,CO 80303. RP Guelachvili, G (reprint author), UNIV PARIS 11,MOLEC PHYS LAB,CNRS UPR 136,BATIMENT 350,F-91405 ORSAY,FRANCE. NR 96 TC 36 Z9 36 U1 1 U2 10 PU ACADEMIC PRESS INC JNL-COMP SUBSCRIPTIONS PI SAN DIEGO PA 525 B ST, STE 1900, SAN DIEGO, CA 92101-4495 SN 0022-2852 J9 J MOL SPECTROSC JI J. Mol. Spectrosc. PD MAY PY 1996 VL 177 IS 1 BP 164 EP 179 DI 10.1006/jmsp.1996.0131 PG 16 WC Physics, Atomic, Molecular & Chemical; Spectroscopy SC Physics; Spectroscopy GA UP553 UT WOS:A1996UP55300022 ER PT J AU Neta, P Grodkowski, J Ross, AB AF Neta, P Grodkowski, J Ross, AB TI Rate constants for reactions of aliphatic carbon-centered radicals in aqueous solution SO JOURNAL OF PHYSICAL AND CHEMICAL REFERENCE DATA LA English DT Article DE alkyl radicals; aminoalkyl radicals; aqueous solution; benzyl radicals; chemical kinetics; haloalkyl radicals; hydroxyalkyl radicals; photolysis; radiolysis; rate constants ID ELECTRON-SPIN-RESONANCE; PULSE-RADIOLYSIS; REDUCTION POTENTIALS; HYDRATED ELECTRONS; ALKYL RADICALS; COMPLEXES; KINETICS; BOND; NITROBENZENES; ELIMINATION AB Absolute rate constants for reactions of aliphatic carbon-centered radicals in aqueous solutions have been compiled and evaluated from the literature. Rate constants are included for reactions of radicals with inorganic and organic compounds and for decay by radical-radical reactions. The radicals were generated by radiolysis, photolysis, or other techniques, and their rate constants were determined generally by kinetic spectrophotometry. The tables include data for over 2,500 reactions of 373 radicals from 740 literature references. (C) 1996 American Institute of Physics and American Chemical Society. C1 UNIV NOTRE DAME,RADIAT LAB,RADIAT CHEM DATA CTR,NOTRE DAME,IN 46556. RP Neta, P (reprint author), NATL INST STAND & TECHNOL,DIV CHEM KINET & THERMODYNAM,GAITHERSBURG,MD 20899, USA. NR 37 TC 126 Z9 126 U1 4 U2 29 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 MAY-JUN PY 1996 VL 25 IS 3 BP 709 EP 1050 PG 342 WC Chemistry, Multidisciplinary; Chemistry, Physical; Physics, Multidisciplinary SC Chemistry; Physics GA UM902 UT WOS:A1996UM90200001 ER PT J AU HowellKubler, AN Lessard, EJ Napp, JM AF HowellKubler, AN Lessard, EJ Napp, JM TI Springtime microprotozoan abundance and biomass in the southeastern Bering Sea and Shelikof Strait, Alaska SO JOURNAL OF PLANKTON RESEARCH LA English DT Article ID EASTERN ENGLISH-CHANNEL; SOUTHERN NORTH-SEA; WALLEYE POLLOCK; THERAGRA-CHALCOGRAMMA; MICROPLANKTON POPULATION; WATER-COLUMN; ICE EDGE; LARVAE; FOOD; SHELF AB We surveyed springtime biomass and abundance of the >20 mu m microprotozoa in surface waters of the SE Bering Sea and Shelikof Strait. Alaska. This study was part of the Fisheries Oceanography Coordinated Investigations (FOCI) program examining processes which affect the recruitment variability of walleye pollock (Theragra chalcogramma). Microprotozoa are a potential prey resource for larval pollock which has not been previously examined. In both areas, the >20 mu m microprotozoa were predominantly dinoflagellates and ciliates. At the time of sampling (May 1990 in Shelikof Strait and April 1992 in the SE Bering Sea), the spring diatom bloom was under way in Shelikof Strait, but not in the SE Bering Sea. Heterotrophic dinoflagellates dominated the microprotozoan assemblage in Shelikof Strait, but not in the SE Bering Sea. In the SE Bering Sea, total microprotozoan abundances ranged from 300 to 6233 organisms l(-1) and biomass from 0.58 to 9.73 mu g C l(-1). In Shelikof Strait, abundance and biomass were higher, ranging from 850 to 14 960 organisms l(-1) and from 1.29 to 70.73 mu g C l(-1), respectively. These biomass levels are comparable to those reported from other coastal and oceanic regions. Microprotozoan biomass levels were sufficient to support the estimated metabolic needs of first-feeding larval walleye pollock. It remains to be shown whether larval pollock use this resource. C1 NOAA,ALASKA FISHERIES SCI CTR,SEATTLE,WA 98115. RP HowellKubler, AN (reprint author), UNIV WASHINGTON,SCH OCEANOG,BOX 357940,SEATTLE,WA 98195, USA. NR 58 TC 16 Z9 17 U1 0 U2 1 PU OXFORD UNIV PRESS UNITED KINGDOM PI OXFORD PA WALTON ST JOURNALS DEPT, OXFORD, ENGLAND OX2 6DP SN 0142-7873 J9 J PLANKTON RES JI J. Plankton Res. PD MAY PY 1996 VL 18 IS 5 BP 731 EP 745 DI 10.1093/plankt/18.5.731 PG 15 WC Marine & Freshwater Biology; Oceanography SC Marine & Freshwater Biology; Oceanography GA UN945 UT WOS:A1996UN94500006 ER PT J AU Peterson, WT Dam, HG AF Peterson, WT Dam, HG TI Pigment ingestion and egg production rates of the calanoid copepod Temora longicornis: Implications for gut pigment loss and omnivorous feeding SO JOURNAL OF PLANKTON RESEARCH LA English DT Article ID LONG-ISLAND SOUND; CHLOROPHYLL-DERIVED PIGMENTS; ACARTIA-TONSA; DIGESTIVE ACCLIMATION; PLANKTONIC COPEPODS; HERBIVOROUS COPEPOD; ZOOPLANKTON; FOOD; PHYTOPLANKTON; DEGRADATION AB We examined the relationship between egg production rate (E) and pigment ingestion rate (I, from gut content corrected for 33% loss) for adult female Temora longicornis in Long Island Sound on 47 occasions. Linear regression of E on I [both variables expressed in mass of nitrogen (N) female(-1) day(-1)] was: E(N) = 0.0016 + 0.770 x I-N. The slope, 0.77, is the apparent gross efficiency of egg production, equivalent to the gross growth efficiency (GGE) assuming that females partition all nitrogen for growth into egg production. Published work suggests that a GGE of 0.37 would be expected for herbivorous copepods. The discrepancy between the expected value of 0.37 and observed value of 0.77 could result from unquantified losses of gut pigment or because T.longicornis ingested a significant amount of nitrogen by feeding as a carnivore. We suggest that if T.longicornis females derive all of their nitrogen for growth by feeding on phytoplankton, and if no correction for pigment loss is employed, then the gut pigment method underestimates pigment ingestion by no more than a factor of two. C1 UNIV CONNECTICUT, DEPT MARINE SCI, GROTON, CT 06340 USA. RP Peterson, WT (reprint author), NOAA, NMFS, HATFIELD MARINE SCI CTR, 2030 MARINE SCI DR, NEWPORT, OR 97365 USA. RI Dam, Hans/A-9723-2015 OI Dam, Hans/0000-0001-6121-5038 NR 31 TC 34 Z9 35 U1 0 U2 2 PU OXFORD UNIV PRESS PI OXFORD PA GREAT CLARENDON ST, OXFORD OX2 6DP, ENGLAND SN 0142-7873 EI 1464-3774 J9 J PLANKTON RES JI J. Plankton Res. PD MAY PY 1996 VL 18 IS 5 BP 855 EP 861 DI 10.1093/plankt/18.5.855 PG 7 WC Marine & Freshwater Biology; Oceanography SC Marine & Freshwater Biology; Oceanography GA UN945 UT WOS:A1996UN94500014 ER PT J AU Khoury, F AF Khoury, F TI Comments on ''The growth of single crystals of linear polyethylene'' SO JOURNAL OF POLYMER SCIENCE PART B-POLYMER PHYSICS LA English DT Editorial Material ID NUCLEATION RP Khoury, F (reprint author), NATL INST STAND & TECHNOL,DIV POLYMERS,GAITHERSBURG,MD 20899, USA. NR 14 TC 0 Z9 0 U1 1 U2 2 PU JOHN WILEY & SONS INC PI NEW YORK PA 605 THIRD AVE, NEW YORK, NY 10158-0012 SN 0887-6266 J9 J POLYM SCI POL PHYS JI J. Polym. Sci. Pt. B-Polym. Phys. PD MAY PY 1996 VL 34 IS 7 BP 1167 EP 1168 DI 10.1002/polb.1996.908 PG 2 WC Polymer Science SC Polymer Science GA UF502 UT WOS:A1996UF50200003 ER PT J AU Gupta, AK Presser, C Hodges, JT Avedisian, CT AF Gupta, AK Presser, C Hodges, JT Avedisian, CT TI Role of combustion on droplet transport in pressure-atomized spray flames SO JOURNAL OF PROPULSION AND POWER LA English DT Article AB The transport of droplets in a pressure atomized kerosene spray flame was examined using a two component phase Doppler system to measure the droplet size and velocity distributions at several locations within the spray. The effect of combustion on droplet transport was examined by comparing the results to a nonburning spray under similar flow conditions. Directions of motion of droplets are calculated from the measured droplet velocity components to provide information on trajectories and dispersion of drop lets. Results show that combustion reduces the strength of gas recirculation as evidenced by significantly fewer droplets being transported upstream toward the nozzle along the centerline for the burning spray as compared to the nonburning spray. Combustion enhances droplet vaporization and results In reduced number density and larger droplet mean diameters and velocities when compared to the nonburning spray. At the spray centerline, there is a wide range of droplet trajectories that are associated with recirculated droplets and those originating from the nozzle. There is some correlation between droplet velocity and diameter Some larger size droplets are also found to be entrained Into the recirculation pattern. At the spray boundary, few droplets deviate from the mean direction. Also, droplet velocity is well correlated with increasing diameter but appears to approach an asymptotic value in which droplet velocity becomes insensitive to diameter. C1 NATL INST STAND & TECHNOL,HIGH TEMP PROC GRP,CHEM SCI & TECHNOL LAB,GAITHERSBURG,MD 20899. NATL INST STAND & TECHNOL,PROC SENSING GRP,CHEM SCI & TECHNOL LAB,GAITHERSBURG,MD 20899. CORNELL UNIV,DEPT MECH & AEROSP ENGN,ITHACA,NY 14853. RP Gupta, AK (reprint author), UNIV MARYLAND,DEPT ENGN MECH,COLLEGE PK,MD 20742, USA. RI Hodges, Joseph/B-4578-2009 NR 18 TC 9 Z9 9 U1 0 U2 3 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 1996 VL 12 IS 3 BP 543 EP 553 DI 10.2514/3.24068 PG 11 WC Engineering, Aerospace SC Engineering GA UL423 UT WOS:A1996UL42300013 ER PT J AU Mighell, AD Karen, VL AF Mighell, AD Karen, VL TI NIST crystallographic databases for research and analysis SO JOURNAL OF RESEARCH OF THE NATIONAL INSTITUTE OF STANDARDS AND TECHNOLOGY LA English DT Article; Proceedings Paper CT NIST Workshop on Crystallographic Databases CY AUG 29-30, 1995 CL NATL INST STAND & TECHNOL CAMPUS, GAITHERSBURG, MD SP Natl Inst Stand & Technol HO NATL INST STAND & TECHNOL CAMPUS DE crystalline materials; crystallography; database; electron diffraction; lattice; lattice relationships; materials design; NIST Crystal Data; phase identification ID IDENTIFICATION AB The NIST Crystal and Electron Diffraction Data Center builds a comprehensive database with evaluated chemical, physical, and crystallographic information on all types of well-characterized substances. The data are evaluated and standardized by specially designed computer programs as well as by experts in the field. From its master database, the Data Center produces NIST Crystal Data and an Electron Diffraction Database with over 220 000 and 81 000 entries, respectively. These distribution databases are made available to the scientific community via CD-ROM, scientific instruments and online systems. In addition, the Data Center has developed theory and software that can be used for establishing all types of lattice relationships, for the determination of symmetry, for the identification of unknowns using lattice matching techniques, and for data evaluation. C1 NATL INST STAND & TECHNOL, CRYSTAL & ELECTRON DIFFRACT DATA CTR, GAITHERSBURG, MD 20899 USA. RP Mighell, AD (reprint author), NATL INST STAND & TECHNOL, MAT SCI & ENGN LAB, GAITHERSBURG, MD 20899 USA. NR 13 TC 9 Z9 9 U1 0 U2 1 PU US GOVERNMENT PRINTING OFFICE PI WASHINGTON PA SUPERINTENDENT DOCUMENTS,, WASHINGTON, DC 20402-9325 USA SN 1044-677X J9 J RES NATL INST STAN JI J. Res. Natl. Inst. Stand. Technol. PD MAY-JUN PY 1996 VL 101 IS 3 BP 273 EP 280 DI 10.6028/jres.101.028 PG 8 WC Instruments & Instrumentation; Physics, Applied SC Instruments & Instrumentation; Physics GA VD605 UT WOS:A1996VD60500011 PM 27805164 ER PT J AU Gilliland, GL Tung, M Ladner, J AF Gilliland, GL Tung, M Ladner, J TI The biological macromolecule crystallization database and NASA protein crystal growth archive SO JOURNAL OF RESEARCH OF THE NATIONAL INSTITUTE OF STANDARDS AND TECHNOLOGY LA English DT Article; Proceedings Paper CT NIST Workshop on Crystallographic Databases CY AUG 29-30, 1995 CL NATL INST STAND & TECHNOL CAMPUS, GAITHERSBURG, MD SP Natl Inst Stand & Technol HO NATL INST STAND & TECHNOL CAMPUS DE Biological Macromolecule Crystallization Database; crystal; microgravity; NASA PCG Archive; nucleic acid; peptide; protein; protein crystallization; x-ray diffraction ID 3-DIMENSIONAL STRUCTURE; CATHEPSIN-D; PURIFICATION; RESOLUTION AB The NIST/NASA/CARB Biological Macromolecule Crystallization Database (BMCD), NIST Standard Reference Database 21, contains crystal data and crystallization conditions for biological macromolecules. The database entries include data abstracted from published crystallographic reports. Each entry consists of information describing the biological macromolecule crystallized and crystal data and the crystallization conditions for each crystal form. The BMCD serves as the NASA Protein Crystal Growth Archive in that it contains protocols and results of crystallization experiments undertaken in microgravity (space). These database entries report the results, whether successful or not, from NASA-sponsored protein crystal growth experiments in microgravity and from microgravity crystallization studies sponsored by other international organizations. The BMCD was designed as a tool to assist x-ray crystallographers in the development of protocols to crystallize biological macromolecules, those that have previously been crystallized, and those that have not been crystallized. C1 NATL INST STAND & TECHNOL, DIV BIOTECHNOL, CHEM & SCI TECHNOL LAB, STRUCT BIOL GRP, ROCKVILLE, MD 20850 USA. RP Gilliland, GL (reprint author), UNIV MARYLAND, INST BIOTECHNOL, CTR ADV RES BIOTECHNOL, 9600 GUDELSKY DR, ROCKVILLE, MD 20850 USA. NR 33 TC 15 Z9 16 U1 0 U2 8 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 1996 VL 101 IS 3 BP 309 EP 320 DI 10.6028/jres.101.032 PG 12 WC Instruments & Instrumentation; Physics, Applied SC Instruments & Instrumentation; Physics GA VD605 UT WOS:A1996VD60500015 PM 11542472 ER PT J AU Feldman, A Malshe, AP Graebner, JE AF Feldman, A Malshe, AP Graebner, JE TI Workshop on characterizing diamond films IV - Gaithersburg, MD March 4-5, 1996 SO JOURNAL OF RESEARCH OF THE NATIONAL INSTITUTE OF STANDARDS AND TECHNOLOGY LA English DT Editorial Material C1 UNIV ARKANSAS, FAYETTEVILLE, AR 72701 USA. LUCENT TECHNOL, MURRAY HILL, NJ 07974 USA. RP Feldman, A (reprint author), NATL INST STAND & TECHNOL, GAITHERSBURG, MD 20899 USA. NR 1 TC 0 Z9 0 U1 0 U2 1 PU US GOVERNMENT PRINTING OFFICE PI WASHINGTON PA SUPERINTENDENT DOCUMENTS,, WASHINGTON, DC 20402-9325 USA SN 1044-677X J9 J RES NATL INST STAN JI J. Res. Natl. Inst. Stand. Technol. PD MAY-JUN PY 1996 VL 101 IS 3 BP 383 EP 385 DI 10.6028/jres.101.042 PG 3 WC Instruments & Instrumentation; Physics, Applied SC Instruments & Instrumentation; Physics GA VD605 UT WOS:A1996VD60500025 PM 27805177 ER PT J AU Frank, C AF Frank, C TI Quest for Excellence VIII - Washington, DC February 5-7, 1996 SO JOURNAL OF RESEARCH OF THE NATIONAL INSTITUTE OF STANDARDS AND TECHNOLOGY LA English DT Editorial Material RP Frank, C (reprint author), NATL INST STAND & TECHNOL, OFF QUAL PROGRAMS, GAITHERSBURG, MD 20899 USA. NR 0 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 1996 VL 101 IS 3 BP 387 EP 393 DI 10.6028/jres.101.043 PG 7 WC Instruments & Instrumentation; Physics, Applied SC Instruments & Instrumentation; Physics GA VD605 UT WOS:A1996VD60500026 PM 27805178 ER PT J AU Rumble, J AF Rumble, J TI NIST workshop on crystallographic databases - Foreword SO JOURNAL OF RESEARCH OF THE NATIONAL INSTITUTE OF STANDARDS AND TECHNOLOGY LA English DT Editorial Material RP Rumble, J (reprint author), NIST, STAND REFERENCE DATA PROGRAM, GAITHERSBURG, MD 20899 USA. NR 0 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 1996 VL 101 IS 3 BP R5 EP R5 DI 10.6028/jres.101.004 PG 1 WC Instruments & Instrumentation; Physics, Applied SC Instruments & Instrumentation; Physics GA VD605 UT WOS:A1996VD60500002 ER PT J AU Niemiec, JM Pesce, JJ McKenna, GB Skocypec, S Garritano, RF AF Niemiec, JM Pesce, JJ McKenna, GB Skocypec, S Garritano, RF TI Anomalies in the normal force measurement when using a force rebalance transducer SO JOURNAL OF RHEOLOGY LA English DT Article ID SHEAR-FLOW; TORSION; BEHAVIOR AB Torque and normal force measurements in torsional experiments provide a powerful technique for the efficient measurement of material properties. Over the past several decades NIST has been active in pioneering the use of such measurements for the characterization of polymer material behaviors, particularly in transient experiments. In a recent series of tests using a force rebalance transducer, anomalies in normal force measurements were observed. It was determined that the active nature of the transducer, which leads to excellent zero stability, causes thermal heating and consequent expansion of the system. The transducer length changes are shown to be the cause of the normal force anomalies and, in collaboration with the equipment manufacturer, suggestions for working around the problem and potential transducer redesign are discussed. (C) 1996 Society of Rheology. C1 NIST,DIV POLYMERS,GAITHERSBURG,MD 20899. RHEOMETR INC,PISCATAWAY,NJ 08854. RI McKenna, Gregory/O-1134-2013 OI McKenna, Gregory/0000-0002-5676-9930 NR 14 TC 10 Z9 10 U1 0 U2 2 PU AMER INST PHYSICS PI WOODBURY PA CIRCULATION FULFILLMENT DIV, 500 SUNNYSIDE BLVD, WOODBURY, NY 11797-2999 SN 0148-6055 J9 J RHEOL JI J. Rheol. PD MAY-JUN PY 1996 VL 40 IS 3 BP 323 EP 334 DI 10.1122/1.550745 PG 12 WC Mechanics SC Mechanics GA UK370 UT WOS:A1996UK37000001 ER PT J AU Fanney, AH Dougherty, BP AF Fanney, AH Dougherty, BP TI The thermal performance of residential electric water heaters subjected to various off-peak schedules SO JOURNAL OF SOLAR ENERGY ENGINEERING-TRANSACTIONS OF THE ASME LA English DT Article AB An increasing number of utilities control the supply of power to residential water heaters as one means of reducing peak electrical demand. Water heaters operated in this manner are referred to as off-peak water heaters. Several utilities are also considering the use of solar domestic water heaters as an additional means of limiting power demand during times of greatest electrical usage. The research described within this paper quantifies the variation in thermal efficiency attributable to subjecting residential electrical water heaters to various off-peak and water removal schedules and, thus, forms a basis of comparison to which the thermal efficiency of solar water heaters or other water heating technologies may be compared. Laboratory tests, where the off-peak period and hot water draw schedule were varied, were conducted on two residential storage water heaters. A computer model of an electric water heater was developed and validated. The laboratory tests and the model were used to quantify the effect that various off-peak and hot water draw schedules have on water heater thermal efficiency. Thermal efficiency was found to vary up to seven percent for water heaters which meet the present minimum efficiency standards as specified within the National Appliance Energy Conservation Act. The energy factor, as measured using the Department of Energy Test procedure for Water Heaters, is. shown to be independent of the off-peak schedule because of a ''normalizing'' that occurs as part of the calculation procedure. RP Fanney, AH (reprint author), NIST,BLDG & FIRE RES LAB,GAITHERSBURG,MD 20899, USA. NR 16 TC 13 Z9 13 U1 0 U2 4 PU ASME-AMER SOC MECHANICAL ENG PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 SN 0199-6231 J9 J SOL ENERG-T ASME JI J. Sol. Energy Eng. Trans.-ASME PD MAY PY 1996 VL 118 IS 2 BP 73 EP 80 DI 10.1115/1.2848010 PG 8 WC Energy & Fuels; Engineering, Mechanical SC Energy & Fuels; Engineering GA UM407 UT WOS:A1996UM40700001 ER PT J AU Schwarz, FP AF Schwarz, FP TI Enthalpy of solution of carbohydrates using a modified differential scanning calorimeter SO JOURNAL OF SOLUTION CHEMISTRY LA English DT Article DE aqueous solutions; carbohydrates; differential scanning calorimetry; enthalpy of fusion; enthalpy of solution; solution calorimetry ID HEAT-CAPACITIES; WATER; SOLVATION; VOLUMES AB A differential scanning calorimeter (DSC) was modified for the determination of enthalpies of solution. The measurements were performed opt aqueous solutions of the deoxy- and fluoro-deoxy derivatives of D-glucopyranose (Glu) where the OH group on the C1, C2, C3, and C6 is replaced by H (1HGlu, 2HGlu, 3HGlu, and 6HGlu) and by F (1FGlu, 2FGlu, 3FGlu, and 6FGlu), 4-deoxy 4-fluoro-alpha-D-glucopyranoside (4FGlu), 1-methoxy-alpha-D-glucopyranoside (alpha MeOGlu), 1-phenoxy-alpha-D-glucopyranoside (alpha PheOGlu), D-mannopyranose (Man), and 3-methoxy-alpha-D-glucopyranoside (3MeOGlu) at 15.1, 25.0, 35.0, and 45.1 degrees C. The enthalpies of solution Delta(s)H(0)(T) ranged from 1.00 +/- 0.25 kJ-mol(-1) for 6HGlu at 15.1 degrees C to 20.4 +/- 1.4 for alpha PhOGlu at 45.1 degrees C and were in good agreement with literature values for Man, alpha Glu, alpha MeOGlu, and 3MeOGlu at 25.0 and 35.0 degrees C and for alpha MeOMan and 2HGlu at 35.0 degrees C. Delta(s)H(0)(T) for the derivatives were then extrapolated up to the melting temperature T-m and compared with their enthalpies of fusion, Delta(f)H, also determined from DSC measurements. If the agreement between Delta(s)H(0)(T-m) and Delta(f)H was within the 95% confidence level, then it was concluded that intermolecular interactions between the carbohydrate molecules in the liquid phase were the same as between the carbohydrate and water molecules in the solution phase. This agreement was observed for aqueous solutions of Man, alpha Glu, alpha MeOGlu, 3HGlu, 3FGlu, and 6FGlu. RP Schwarz, FP (reprint author), NIST,CTR ADV RES BIOTECHNOL,9600 GUDELSKY DR,ROCKVILLE,MD 20850, USA. NR 21 TC 10 Z9 10 U1 1 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 MAY PY 1996 VL 25 IS 5 BP 471 EP 484 DI 10.1007/BF00972993 PG 14 WC Chemistry, Physical SC Chemistry GA UX333 UT WOS:A1996UX33300004 ER PT J AU Simiu, E Heckert, NA AF Simiu, E Heckert, NA TI Extreme wind distribution tails: A ''peaks over threshold'' approach SO JOURNAL OF STRUCTURAL ENGINEERING-ASCE LA English DT Article AB We seek to ascertain whether the reverse Weibull distribution is an appropriate extreme windspeed model by performing statistical analyses based on the ''peaks over threshold'' approach. We use the de Haan method, which was found in previous studies to perform about as well or better than the Pickands and cumulative mean exceedance methods, and has the advantage of providing estimates of confidence bounds. The data are taken principally from records of the largest daily wind speeds obtained over periods of 15 to 26 years at 44 U.S. weather stations in areas not subjected to mature hurricane winds. From these records we create samples with reduced mutual correlation among the data. In our opinion, the analyses provide persuasive evidence that extreme wind speeds are described predominantly by reverse Weibull distributions, which unlike the Gumbel distribution have a finite upper tail and lead to reasonable estimates of wind load factors. Instructions are provided for accessing the data and attendant programs. C1 NATL INST STAND & TECHNOL,COMP & APPL MATH LAB,GAITHERSBURG,MD 20899. RP Simiu, E (reprint author), NATL INST STAND & TECHNOL,BLDG & FIRE RES LAB,GAITHERSBURG,MD 20899, USA. NR 20 TC 106 Z9 120 U1 1 U2 8 PU ASCE-AMER SOC CIVIL ENG PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017-2398 SN 0733-9445 J9 J STRUCT ENG-ASCE JI J. Struct. Eng.-ASCE PD MAY PY 1996 VL 122 IS 5 BP 539 EP 547 DI 10.1061/(ASCE)0733-9445(1996)122:5(539) PG 9 WC Construction & Building Technology; Engineering, Civil SC Construction & Building Technology; Engineering GA UG894 UT WOS:A1996UG89400010 ER PT J AU Soler, T AlvarezGarcia, G HernandezNavarro, A Foote, RH AF Soler, T AlvarezGarcia, G HernandezNavarro, A Foote, RH TI GPS high accuracy geodetic networks in Mexico SO JOURNAL OF SURVEYING ENGINEERING-ASCE LA English DT Article ID SYSTEM AB Recently, Mexico's Instituto Nacional de Estadistica, Geografia e Informatica (INEGI) adopted a geocentric three-dimensional coordinate system as the basis for all its national geodetic and mapping needs. The selected frame is the International Earth Rotation Service (IERS) Terrestrial Reference Frame of year 1992 (ITRF92), epoch 1988.0. The geometric surface of choice is the ellipsoid of the Geodetic Reference System of 1980 (GRS80). The implementation of this ge ocentric datum permits the integration of all geodesy, engineering surveys, mapping, and land information systems of Mexico into a modern framework consistent with present accuracies obtainable through the global positioning system (GPS). The practical realization of the spatial reference system was done in cooperation with the National Oceanic and Atmospheric Administration's (NOAA) National Geodetic Survey (NGS) through a series of coordinated GPS projects. As a result, Mexico established 14 permanent GPS trackers (A-order stations) from which the less accurate B-order GPS network was propagated. With this implementation, INEGI assures that the requirements of modern geodetic and cartographic operations in Mexico will be met for many years to come. Updated results, procedures, and data analysis are presented here. RP Soler, T (reprint author), NOAA,NOS,NATL GEODET SURVEY,GLOBAL POSITIONING BRANCH,1315 EAST WEST HIGHWAY,SILVER SPRING,MD 20910, USA. RI Soler, Tomas/F-6386-2010; Namikawa, Laercio/C-5559-2013 OI Namikawa, Laercio/0000-0001-7847-1804 NR 19 TC 4 Z9 4 U1 0 U2 0 PU ASCE-AMER SOC CIVIL ENG PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017-2398 SN 0733-9453 J9 J SURV ENG-ASCE JI J. Surv. Eng.-ASCE PD MAY PY 1996 VL 122 IS 2 BP 80 EP 94 DI 10.1061/(ASCE)0733-9453(1996)122:2(80) PG 15 WC Engineering, Civil SC Engineering GA UH610 UT WOS:A1996UH61000004 ER PT J AU Green, MC Pitchford, ML Ashbaugh, L AF Green, MC Pitchford, ML Ashbaugh, L TI Identification of candidate clean air corridors for the Colorado plateau SO JOURNAL OF THE AIR & WASTE MANAGEMENT ASSOCIATION LA English DT Article AB The U.S. Clean Air Act, amended in 1990, mandated the establishment of the Grand Canyon Visibility Transport Commission (GCVTC). The commission is required to submit a report to the U.S. Environmental Protection Agency addressing visibility issues in the region, including ''the establishment of clean air corridors, in which additional restrictions on increases in emissions may be appropriate to protect visibility in affected Class I areas.'' This paper presents a methodology to identify candidate geographic areas for consideration for Clean Air Corridor (CAC) status for Colorado Plateau Class I areas. The methodology uses thousands of model determined trajectories over a five year pe riod (1988 to 1992) to indicate the paths taken by air that arrives during clean air conditions at Class I areas. These clean air back-trajectories identify upwind areas where pollution emissions could jeopardize currently pristine visibility. Using this methodology, six candidate areas are identified, ranging in size from 75,000 to 506,000 square miles, and permitting varying levels of visibility protection for clean air days at Grand Canyon, Canyonlands, and Petrified Forest National Parks. Assuming effective emissions management of the CAC, the larger the CAC, the greater the visibility protection during clean air conditions. C1 NOAA,AIR RESOURCES LAB,SPECIAL OPERAT & RES DIV,APPL SCI BRANCH,LAS VEGAS,NV. UNIV CALIF DAVIS,CROCKER NUCL LAB,DAVIS,CA 95616. RP Green, MC (reprint author), DESERT RES INST,755 E FLAMINGO,LAS VEGAS,NV 89119, USA. RI Ashbaugh, Lowell/G-3661-2011 NR 13 TC 2 Z9 2 U1 0 U2 0 PU AIR & WASTE MANAGEMENT ASSOC PI PITTSBURGH PA PO BOX 2861, PITTSBURGH, PA 15230 SN 1047-3289 J9 J AIR WASTE MANAGE JI J. Air Waste Manage. Assoc. PD MAY PY 1996 VL 46 IS 5 BP 441 EP 449 PG 9 WC Engineering, Environmental; Environmental Sciences; Meteorology & Atmospheric Sciences SC Engineering; Environmental Sciences & Ecology; Meteorology & Atmospheric Sciences GA UJ647 UT WOS:A1996UJ64700006 ER PT J AU Allen, AJ Krueger, S Skandan, G Long, GG Hahn, H Kerch, HM Parker, JC Ali, MN AF Allen, AJ Krueger, S Skandan, G Long, GG Hahn, H Kerch, HM Parker, JC Ali, MN TI Microstructural evolution during the sintering of nanostructured ceramic oxides SO JOURNAL OF THE AMERICAN CERAMIC SOCIETY LA English DT Article ID ANGLE NEUTRON-SCATTERING; X-RAY-SCATTERING; DENSIFICATION; ZIRCONIA; BEHAVIOR; POWDERS; Y2O3 AB Using small-angle scattering, together with density measurements, X-ray diffraction, nitrogen adsorption, and both transmission and scanning electron microscopy, the microstructural evolution during sintering in nanostructured ceramic oxides has been studied. The availability of samples with sufficient size and uniformity has permitted absolute calibration of the scattering data and made possible determinations of microstructural parameters and surface areas that are statistically representative of the undisturbed nanophase morphologies. A fully quantitative microstructural model has been developed, and the effects of varying processing parameters during powder synthesis and sintering have been assessed. Predictions are made regarding the achievable sintered full-density microstructures. C1 UNIV MARYLAND,DEPT MAT & NUCL ENGN,COLLEGE PK,MD 20742. RUTGERS STATE UNIV,DEPT MECH & MAT SCI,PISCATAWAY,NJ 08855. TH DARMSTADT,DEPT MAT SCI,D-64295 DARMSTADT,GERMANY. US DOE,OFF BASIC ENERGY SCI,GERMANTOWN,DC 20545. NANOPHASE TECHNOL CORP,BURR RIDGE,IL 60521. RP Allen, AJ (reprint author), NATL INST STAND & TECHNOL,MAT SCI & ENGN LAB,GAITHERSBURG,MD 20899, USA. RI Hahn, Horst/G-9018-2011 OI Hahn, Horst/0000-0001-9901-3861 NR 29 TC 32 Z9 33 U1 1 U2 7 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 1996 VL 79 IS 5 BP 1201 EP 1212 DI 10.1111/j.1151-2916.1996.tb08573.x PG 12 WC Materials Science, Ceramics SC Materials Science GA UM323 UT WOS:A1996UM32300009 ER PT J AU Lewis, JA Galler, MA Bentz, DP AF Lewis, JA Galler, MA Bentz, DP TI Computer simulations of binder removal from 2-D and 3-D model particulate bodies SO JOURNAL OF THE AMERICAN CERAMIC SOCIETY LA English DT Article ID MONTE-CARLO SIMULATION; DIFFUSION; CONDUCTIVITY; THERMOLYSIS; BURNOUT; MEDIA AB A series of computer simulations were developed to investigate the removal of multicomponent, thermoplastic binders from two- and three-dimensional model particulate bodies, Monosized particles with varying diameters were randomly placed in such systems, and all unoccupied pixels were assigned to the binder phase at ratios of 1:9, 1:2, or 1:1 plasticizer (volatile) to polymeric (nonvolatile) species, Simulations were carried out under isothermal conditions to study the influence of liquid-phase transport processes, i,e,, plasticizer diffusion in the binder-filled pore network and capillary-driven redistribution of the binder phase, on plasticizer removal rates, Plasticizer diffusion was modeled by a random-walk algorithm, and nonplanar pore development arising from capillary-driven binder redistribution was modeled by an invasion percolation algorithm, For comparison, simulations were also carried out on systems in which binder redistribution was not permitted, In such cases, pore development was modeled as an advancing or nonadvancing planar front, Visualization of transport phenomena on a microscopic scale has provided the first quantitative assessment of plasticizer concentration profiles, C(t) and C(z), and binder-vapor interfacial development during removal, Removal rates were significantly enhanced when capillary-driven binder redistribution was assumed, and they depended strongly on initial plasticizer content under those conditions. C1 UNIV ILLINOIS,BECKMAN INST ADV SCI & TECHNOL,URBANA,IL 61801. NATL INST STAND & TECHNOL,US DEPT COMMERCE,TECHNOL ADM,BLDG & FIRE RES LAB,BLDG MAT DIV,GAITHERSBURG,MD 20899. RP Lewis, JA (reprint author), UNIV ILLINOIS,DEPT MAT SCI & ENGN,1304 W GREEN ST,URBANA,IL 61801, USA. NR 32 TC 17 Z9 17 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 1996 VL 79 IS 5 BP 1377 EP 1388 DI 10.1111/j.1151-2916.1996.tb08599.x PG 12 WC Materials Science, Ceramics SC Materials Science GA UM323 UT WOS:A1996UM32300035 ER PT J AU Zimmerman, MH Faber, KT Fuller, ER Kruger, KL Bowman, KJ AF Zimmerman, MH Faber, KT Fuller, ER Kruger, KL Bowman, KJ TI Texture assessment of magnetically processed iron titanate SO JOURNAL OF THE AMERICAN CERAMIC SOCIETY LA English DT Article ID THERMAL-EXPANSION ANISOTROPY; GRAIN-SIZE DEPENDENCE; BRITTLE MATERIALS; POLE FIGURES; SUPERCONDUCTORS; MICROCRACKING; CRACKING; CERAMICS AB Untextured and highly textured iron titanate specimens were produced by vacuum filtering iron titanate-ethanol suspensions in the absence and presence of a strong magnetic field, respectively, Crystallographic texture was assessed by measuring X-ray pole figures on surfaces parallel and perpendicular to the field direction for several peaks in each system, Morphological texture was assessed by measuring grain size as a function of angle to a reference direction, Results indicate that magnetic field processing imposes a strong, fiber-type texture on the order of 30 times random, with the b-axis parallel to the applied field, Additionally, morphological texturing is absent for the grain sizes studied in this work. C1 NIST,DIV CERAM,GAITHERSBURG,MD 20899. PURDUE UNIV,SCH MAT ENGN,W LAFAYETTE,IN 47907. RP Zimmerman, MH (reprint author), NORTHWESTERN UNIV,ROBERT R MCCORMICK SCH ENGN & APPL SCI,DEPT MAT SCI & ENGN,EVANSTON,IL 60208, USA. RI Faber, Katherine/B-6741-2009 NR 25 TC 11 Z9 11 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 MAY PY 1996 VL 79 IS 5 BP 1389 EP 1393 DI 10.1111/j.1151-2916.1996.tb08600.x PG 5 WC Materials Science, Ceramics SC Materials Science GA UM323 UT WOS:A1996UM32300036 ER PT J AU Pavan, V Held, IM AF Pavan, V Held, IM TI The diffusive approximation for eddy fluxes in baroclinically unstable jets SO JOURNAL OF THE ATMOSPHERIC SCIENCES LA English DT Article ID QUASI-GEOSTROPHIC TURBULENCE; CIRCULATION; ADJUSTMENT; ATMOSPHERE; MODEL AB A series of statistically steady states for baroclinically unstable jets in a two-layer quasigeostrophic model is examined, in order to evaluate diffusive approximations to the eddy potential vorticity or heat fluxes. The flow is forced by thermal relaxation to an unstable ''radiative equilibrium'' temperature gradient. The statistically steady states are studied as a function of the width of the radiative equilibrium jet. A local diffusive ''theory'' for the eddy fluxes is obtained from integrations of a homogeneous, doubly periodic model with prescribed environmental potential vorticity gradients. The flux-gradient relationship generated by the homogeneous model predicts the magnitude and shape of the eddy fluxes in the unstable jet flows remarkably well, as long as the jet is not too narrow. These results confirm the relevance of diffusive closures for eddy potential vorticity and heat fluxes in such flows. For narrow jets that produce eddy fluxes with a half-width of one to two radii of deformation, this local theory underpredicts the fluxes. C1 PRINCETON UNIV,NOAA,GEOPHYS FLUID DYNAM LAB,PRINCETON,NJ 08542. PRINCETON UNIV,PROGRAM ATMOSPHER & OCEAN SCI,PRINCETON,NJ 08544. NR 14 TC 52 Z9 52 U1 0 U2 0 PU AMER METEOROLOGICAL SOC PI BOSTON PA 45 BEACON ST, BOSTON, MA 02108-3693 SN 0022-4928 J9 J ATMOS SCI JI J. Atmos. Sci. PD MAY 1 PY 1996 VL 53 IS 9 BP 1262 EP 1272 DI 10.1175/1520-0469(1996)053<1262:TDAFEF>2.0.CO;2 PG 11 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA UK143 UT WOS:A1996UK14300003 ER PT J AU Wilson, RJ Hamilton, K AF Wilson, RJ Hamilton, K TI Comprehensive model simulation of thermal tides in the Martian atmosphere SO JOURNAL OF THE ATMOSPHERIC SCIENCES LA English DT Article ID GENERAL-CIRCULATION MODEL; GLOBAL DUST STORMS; ZONAL-MEAN CIRCULATION; UPPER-STRATOSPHERE; SYMMETRIC MODES; MARS; WINDS; WAVES; WAVENUMBER-2; DYNAMICS AB This paper discusses the thermotidal oscillations in simulations performed with a newly developed comprehensive general circulation model of the Martian atmosphere. With reasonable assumptions about the effective thermal inertia of the planetary surface and about the distribution of radiatively active atmospheric aerosol, the model produces both realistic zonal-mean temperature distributions and a diurnal surface pressure oscillation of at least roughly realistic amplitude. With any reasonable aerosol distribution, the simulated diurnal pressure oscillation has a very strong zonal variation, in particular a very pronounced zonal wavenumber-2 modulation. This results from a combination of the prominent wave-2 component in the important boundary forcings (topography and surface thermal inertia) and from the fact that the eastward-propagating zonal wave-1 Kelvin normal mode has a period near 1 sol (a Martian mean solar day of 88 775 s). The importance of global resonance is explicitly demonstrated with a series of calculations in which the global mean temperature is arbitrarily altered. The resonant enhancement of the diurnal wave-1 Kelvin mode is predicted to be strongest in the northern summer season. In the model simulations there is also a strong contribution to the semidiurnal tide from a near-resonant eastward-propagating wave-2 Kelvin mode. It is shown that this is significantly forced by a nonlinear steepening of the diurnal Kelvin wave. The daily variations of near-surface winds in the model are also examined. The results show that the daily march of wind at any location depends strongly on the topography, even on the smallest horizontal scales resolved in the model (similar to few hundred km). The global tides also play an important role in determining the near-surface winds, especially so in very dusty atmospheric conditions. The results for the diurnal and semidiurnal surface pressure oscillations in seasonal integrations of the model are compared in detail with the observations at the two Viking Lander sites (22 degrees N and 48 degrees N). The observations over much of the year can be reasonably reproduced in simulations with a globally uniform aerosol mixing ratio (and assuming more total aerosol in the northern winter season, when the largest dust storms are generally observed). There are features of the Viking observations that do not seem to be explainable in this way, however. In particular, in early northern summer, the model predicts amplitudes for the diurnal pressure oscillation at both lander sites that are at least a factor of 2 larger than observed. Results are presented showing that the low amplitudes observed could be explained in the dust distribution tended to be concentrated over the highlands, rather than being uniformly mixed. Annual cycle simulations with a version of the model with an interactive dust transport do in fact reveal the tendency of the circulation to organize so that larger dust mixing ratios occur over highlands, particularly near subsolar latitudes. When the model includes globally uniform surface dust injection and parameterized dust sedimentation, the annual cycle of the diurnal and semidiurnal tides at both lander sites can be rather well reproduced, except for the periods of global dust storms. The attempts to simulate the observed rapid evolution of the tidal pressure oscillations during the onset of a global dust storm also demonstrate the importance of a nonuniform dust concentration. Simulations with the version of the model incorporating interactive dust are able to roughly reproduce the Viking observations when a strong zonally uniform dust injection is prescribed in the Southern Hemisphere Tropics and subtropics. RP Wilson, RJ (reprint author), PRINCETON UNIV,NOAA,GEOPHYS FLUID DYNAM LAB,POB 308,PRINCETON,NJ 08542, USA. NR 88 TC 183 Z9 184 U1 1 U2 9 PU AMER METEOROLOGICAL SOC PI BOSTON PA 45 BEACON ST, BOSTON, MA 02108-3693 SN 0022-4928 J9 J ATMOS SCI JI J. Atmos. Sci. PD MAY 1 PY 1996 VL 53 IS 9 BP 1290 EP 1326 PG 37 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA UK143 UT WOS:A1996UK14300005 ER PT J AU Paul, AE Bolger, IA Smirl, AL Pellegrino, JG AF Paul, AE Bolger, IA Smirl, AL Pellegrino, JG TI Time-resolved measurements of the polarization state of four-wave mixing signals from GaAs multiple quantum wells SO JOURNAL OF THE OPTICAL SOCIETY OF AMERICA B-OPTICAL PHYSICS LA English DT Article ID 4-WAVE-MIXING SIGNALS; EXCITONS; DEPENDENCE; SEMICONDUCTORS; GENERATION; BIEXCITONS; DYNAMICS; LIGHT; RULES AB The complete polarization state of the degenerate four-wave mixing signal from a GaAs/AlxGa1-xAs multiple quantum well is determined by time resolution of all four of its Stokes parameters as a function of the relative angle between the two linear input polarizations. The degree of ellipticity and the orientation of the polarization ellipse are both observed to vary dramatically in time, and the temporal evolution is found to depend strongly on the orientation of the input polarizations. These time-resolved results are shown to be consistent with previous measurements of the time-integrated Stokes parameters and to provide new constraints for physical models. The results are shown to be qualitatively consistent with a phenomenological model requiring the inclusion of both many-body interactions and biexcitonic effects. (C) 1996 Optical Society of America. C1 NATL INST STAND & TECHNOL, GAITHERSBURG, MD 20899 USA. RP Paul, AE (reprint author), UNIV IOWA, LAB PHOTON & QUANTUM ELECTR, IOWA ADV TECHNOL LABS 100, IOWA CITY, IA 52242 USA. RI Schaff, William/B-5839-2009 NR 38 TC 44 Z9 44 U1 0 U2 2 PU OPTICAL SOC AMER PI WASHINGTON PA 2010 MASSACHUSETTS AVE NW, WASHINGTON, DC 20036 USA SN 0740-3224 J9 J OPT SOC AM B JI J. Opt. Soc. Am. B-Opt. Phys. PD MAY PY 1996 VL 13 IS 5 BP 1016 EP 1025 DI 10.1364/JOSAB.13.001016 PG 10 WC Optics SC Optics GA UJ960 UT WOS:A1996UJ96000032 ER PT J AU Abbott, PJ Tison, SA AF Abbott, PJ Tison, SA TI Commercial helium permeation leak standards: Their properties and reliability SO JOURNAL OF VACUUM SCIENCE & TECHNOLOGY A-VACUUM SURFACES AND FILMS LA English DT Article; Proceedings Paper CT 42nd National Symposium of the American-Vacuum-Society CY OCT 16-20, 1995 CL MINNEAPOLIS, MN SP Amer Vacuum Soc AB Standard leaks or leak artifacts are used extensively in industrial and research environments, typically for the calibration of helium leak detectors. The most commonly used leak is the helium permeation type, which uses a glass, quartz, or polymer barrier to restrict the flow of helium via diffusion. Physical leaks, on the other hand, use a physically restrictive element to limit the flow. This article will discuss the properties and reliability of helium permeation standard leaks, based on eight years of accumulated calibration data. Physical helium leaks will not be discussed since relatively few have been calibrated at the National Institute of Standards and Technology. RP Abbott, PJ (reprint author), NIST,DIV THERMOPHYS,CHEM SCI & TECHNOL LAB,GAITHERSBURG,MD 20899, USA. NR 5 TC 4 Z9 4 U1 0 U2 8 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 1996 VL 14 IS 3 BP 1242 EP 1246 DI 10.1116/1.579935 PN 1 PG 5 WC Materials Science, Coatings & Films; Physics, Applied SC Materials Science; Physics GA UR134 UT WOS:A1996UR13400110 ER PT J AU LiebmannVinson, A Lander, LM Foster, MD Brittain, WJ Vogler, EA Majkrzak, CF Satija, S AF LiebmannVinson, A Lander, LM Foster, MD Brittain, WJ Vogler, EA Majkrzak, CF Satija, S TI A neutron reflectometry study of human serum albumin adsorption in situ SO LANGMUIR LA English DT Article ID DEPENDENT CONTACT ANGLES; SOLID LIQUID ADSORPTION; SPECULAR REFLECTION; PROTEIN ADSORPTION; SURFACE-ACTIVITY; WATER INTERFACE; PRACTICAL USE; X-RAY; PROFILES; SILICON AB Reflectometry is used to characterize silicon-wafer-supported NH3+-terminated self-assembled silane monolayers (SAMs) and silicon oxide (SiOx) surfaces against air, water, and human serum albumin (HSA) solutions. X-ray reflectometry (XR) of the NH3+-terminated SAM in air revealed a 14 Angstrom thick, close-packed silane monolayer consistent with an all-trans extended hydrocarbon chain packing tilted about 30 degrees with respect to the surface normal. Neutron reflectometry (NR) of the NH3+ surface against D2O was consistent with (XR) results if it was assumed that labile protons exchange with deuterium resulting in an interface comprised largely of ND3+. NR results obtained with the SiOx surface against D2O were interpreted in terms of a porous, hydrated oxide layer about 20 Angstrom thick. NR of HSA adsorbed from D2O buffer onto NH3+ terminated SAM surfaces revealed a two-layer adsorption regime. The first layer directly adjacent to the solid surface was about 40 Angstrom thick and was essentially independent of bulk liquid concentration whereas the second layer was more strongly dependent on liquid phase concentration studied, extending an additional 40 Angstrom into solution at the maximum solution concentration (0.1% wt/V). NR results are thus consistent with multilayer or mixed-layer protein adsorption mechanism and formation of an interphase region about 80 Angstrom in thickness that separates bulk solid and bulk liquid phases. By contrast, no such interphase could be resolved for an HSA solution in contact with a water-wettable SiOx surface, suggesting that HSA does not adsorb to fully-water-wettable surfaces from water. Implications of these results in biomaterials science, especially blood contact phenomena, are briefly discussed in the summary. C1 NIST,DIV REACTOR RADIAT,GAITHERSBURG,MD 20899. UNIV AKRON,INST POLYMER SCI,AKRON,OH 44325. BECTON DICKINSON RES CTR,POLYMER SCI & TECHNOL DEPT,RES TRIANGLE PK,NC 27709. NR 37 TC 56 Z9 57 U1 0 U2 9 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 SN 0743-7463 J9 LANGMUIR JI Langmuir PD MAY 1 PY 1996 VL 12 IS 9 BP 2256 EP 2262 DI 10.1021/la950642d PG 7 WC Chemistry, Multidisciplinary; Chemistry, Physical; Materials Science, Multidisciplinary SC Chemistry; Materials Science GA UJ056 UT WOS:A1996UJ05600022 ER PT J AU Sunda, WG Huntsman, SA AF Sunda, WG Huntsman, SA TI Antagonisms between cadmium and zinc toxicity and manganese limitation in a coastal diatom SO LIMNOLOGY AND OCEANOGRAPHY LA English DT Article ID CELLULAR MANGANESE; TRANSPORT; GROWTH; PHYTOPLANKTON; THALASSIOSIRA; ESTUARINE; COPPER; RATES AB Long-term growth and metal (Mn and Cd) uptake experiments and short-term uptake kinetic experiments with the coastal diatom Thalassiosira pseudonana revealed antagonistic interactions between toxic metals (Zn and Cd) and the micronutrient manganese. Cd and Zn inhibited algal growth rate only at low Mn ion concentrations, an effect that could be totally accounted for by an inhibition of cellular Mn uptake by the toxic metals and the resultant generation of Mn-deficient cells. Mn and Zn inhibited cellular Cd uptake, indicating reciprocal effects among the metals with respect to uptake. Saturation kinetics modeling of the uptake data was consistent with all three metals competing with each other for binding to the Mn uptake system and with both Cd and Mn being transported into the cell by that system (uptake of Zn was not measured). Mathematical modeling of Mn and Cd uptake data revealed evidence for a Cd efflux system that was induced only at high cellular Cd concentrations and prevented cellular Cd from reaching toxic levels. RP Sunda, WG (reprint author), NOAA, NATL MARINE FISHERIES SERV, BEAUFORT LAB, 101 PIVERS ISL RD, BEAUFORT, NC 28516 USA. NR 19 TC 115 Z9 120 U1 2 U2 12 PU AMER SOC LIMNOLOGY OCEANOGRAPHY PI WACO PA 5400 BOSQUE BLVD, STE 680, WACO, TX 76710-4446 USA SN 0024-3590 J9 LIMNOL OCEANOGR JI Limnol. Oceanogr. PD MAY PY 1996 VL 41 IS 3 BP 373 EP 387 PG 15 WC Limnology; Oceanography SC Marine & Freshwater Biology; Oceanography GA UW657 UT WOS:A1996UW65700001 ER PT J AU Armstrong, RW Ruff, AW Shin, H AF Armstrong, RW Ruff, AW Shin, H TI Elastic, plastic and cracking indentation behavior of silicon crystals SO MATERIALS SCIENCE AND ENGINEERING A-STRUCTURAL MATERIALS PROPERTIES MICROSTRUCTURE AND PROCESSING LA English DT Article; Proceedings Paper CT 5th International Conference on the Science of Hard Materials (ICSHM 5) CY FEB 20-24, 1995 CL MAUI, HI SP Kennametal Inc, KMS Instruments, Norton Co, Reed Tool Co, Elsevier Sci SA DE elasticity; plasticity; cracking indentations; silicon crystals ID INITIATION; FRACTURE AB The ambient temperature indentation hardness properties of silicon crystals have been studied over the full range of their nanoscale elastic/plastic and microscale elastic/plastic/cracking behaviors. The material properties are interpreted on the basis of applied force versus residual indentation size or crack size measurements and, also, on the basis of computed hardness stress-strain dependencies. Cracking, when it occurs, is attributed to sessile dislocation reactions that are initiated at microslip system intersections. Significant hardening was revealed in nanoindentation tests of carbon-ion implanted material, particularly, for crack-free plastic deformation obtained when silicon carbide was formed in the crystal surface layer by high temperature implantation. Otherwise, continuous force vs. displacement curves were employed to track the occurrence of cracking during indenter loading and crack growth on unloading, as facilitated in the latter case by the residual plastic deformation produced during the loading part of the hardness cycle. C1 NIST, DIV CERAM, GAITHERSBURG, MD 20899 USA. SAMSUNG ELECTR CO LTD, CORE TECHNOL RES CTR, SUWON, KYUNGKI DO, SOUTH KOREA. RP UNIV MARYLAND, DEPT MECH ENGN, COLLEGE PK, MD 20742 USA. NR 19 TC 21 Z9 21 U1 0 U2 10 PU ELSEVIER SCIENCE SA PI LAUSANNE PA PO BOX 564, 1001 LAUSANNE, SWITZERLAND SN 0921-5093 EI 1873-4936 J9 MAT SCI ENG A-STRUCT JI Mater. Sci. Eng. A-Struct. Mater. Prop. Microstruct. Process. PD MAY PY 1996 VL 209 IS 1-2 BP 91 EP 96 DI 10.1016/0921-5093(95)10148-9 PG 6 WC Nanoscience & Nanotechnology; Materials Science, Multidisciplinary; Metallurgy & Metallurgical Engineering SC Science & Technology - Other Topics; Materials Science; Metallurgy & Metallurgical Engineering GA UT952 UT WOS:A1996UT95200016 ER PT J AU Madden, RP OBrian, TR Parr, AC Saunders, RD Sapritsky, VI AF Madden, RP OBrian, TR Parr, AC Saunders, RD Sapritsky, VI TI A method of realizing spectral-radiance and irradiance scales based on comparison of synchrotron and high-temperature black-body radiation SO METROLOGIA LA English DT Article; Proceedings Paper CT 5th International Conference on Radiometry CY SEP 19-21, 1994 CL BERLIN, GERMANY SP Phys Tech Bundesanstalt ID STANDARDS; SURF AB Improvements in synchrotron radiation and high-temperature black-body sources will provide a method of realizing scales of spectral radiance and irradiance with uncertainties comparable with those provided by absolute cryogenic radiometers. This paper discusses planned improvements in the synchrotron radiation facility at the National Institute of Standards and Technology (NIST), and how these improvements can be exploited to accurately measure the temperature of a high-temperature black body developed at the All-Russian Research Institute for Optophysical Measurements (VNIIOFI), thus allowing substantial improvement in radiometric scales. C1 ALL RUSSIAN OPTOPHYS MEASUREMENTS RES INST,MOSCOW 119361,RUSSIA. RP Madden, RP (reprint author), NATL INST STAND & TECHNOL,GAITHERSBURG,MD 20899, USA. NR 12 TC 8 Z9 8 U1 0 U2 0 PU BUREAU INT POIDS MESURES PI SEVRES CEDEX PA B1 PM PAVILLION DE BRETUEIL, F-92312 SEVRES CEDEX, FRANCE SN 0026-1394 J9 METROLOGIA JI Metrologia PD MAY PY 1996 VL 32 IS 6 BP 425 EP 429 DI 10.1088/0026-1394/32/6/4 PG 5 WC Instruments & Instrumentation; Physics, Applied SC Instruments & Instrumentation; Physics GA UU321 UT WOS:A1996UU32100004 ER PT J AU OBrian, TR Johnson, BC Sakuma, F AF OBrian, TR Johnson, BC Sakuma, F TI Direct comparison of copper and gold freezing-point black-body primary standards from the NRLM and the NIST SO METROLOGIA LA English DT Article; Proceedings Paper CT 5th International Conference on Radiometry CY SEP 19-21, 1994 CL BERLIN, GERMANY SP Phys Tech Bundesanstalt ID THERMODYNAMIC TEMPERATURES; ITS-90 AB Freezing-point black bodies used as primary standards of spectral radiance at two national standards laboratories are directly intercompared for the first time. The spectral radiance ratio is directly measured for a copper freezing-point black body from the National Research Laboratory of Metrology (NRLM), Japan, and a gold freezing-point black body from the National Institute of Standards and Technology (NIST), USA. Narrowband spectral radiance measurements at five wavelengths between 546 nm and 878 nm show the NRLM copper to NIST gold freezing-point temperature interval to be 20,39 K +/- 0,12 K (2 sigma), in good agreement with the International Temperature Scale of 1990 (ITS-90) value of 20,44 K, and comfortably within the combined uncertainties assigned to the realization of the ITS-90 from each source. C1 NATL RES LAB METROL,TSUKUBA,IBARAKI 305,JAPAN. RP OBrian, TR (reprint author), NATL INST STAND & TECHNOL,GAITHERSBURG,MD 20899, USA. NR 14 TC 3 Z9 3 U1 0 U2 0 PU BUREAU INT POIDS MESURES PI SEVRES CEDEX PA B1 PM PAVILLION DE BRETUEIL, F-92312 SEVRES CEDEX, FRANCE SN 0026-1394 J9 METROLOGIA JI Metrologia PD MAY PY 1996 VL 32 IS 6 BP 445 EP 448 DI 10.1088/0026-1394/32/6/8 PG 4 WC Instruments & Instrumentation; Physics, Applied SC Instruments & Instrumentation; Physics GA UU321 UT WOS:A1996UU32100008 ER PT J AU Saunders, RD Gibson, CE Mielenz, KD Sapritsky, VI Sudarev, KA Khlevnoy, BB Mekhontsev, SN Harchenko, GD AF Saunders, RD Gibson, CE Mielenz, KD Sapritsky, VI Sudarev, KA Khlevnoy, BB Mekhontsev, SN Harchenko, GD TI Results of a NIST/VNIIOFI comparison of spectral-radiance measurements SO METROLOGIA LA English DT Article; Proceedings Paper CT 5th International Conference on Radiometry CY SEP 19-21, 1994 CL BERLIN, GERMANY SP Phys Tech Bundesanstalt AB A comparison of the spectral-radiance scales of the National Institute of Standards and Technology (NIST) and the All-Russian Research Institute for Optophysical Measurements (VNIIOFI) was carried out in 1989 and 1990. The spectral range of the comparison was between 240 nm and 2400 nm. The transfer standards were argon-filled tungsten ribbon filament lamps. The NIST/VNIIOFI agreement was 0,5 % to 1 % in the 240 nm to 800 nm range, and better than 0,5 % between 900 nm and 2400 nm. On average, the spectral radiances measured at the VNIIOFI were slightly higher than the NIST values. C1 ALL RUSSIAN OPTOPHYS MEASUREMENTS RES INST,MOSCOW 119361,RUSSIA. RP Saunders, RD (reprint author), NATL INST STAND & TECHNOL,GAITHERSBURG,MD 20899, USA. NR 8 TC 8 Z9 8 U1 0 U2 0 PU BUREAU INT POIDS MESURES PI SEVRES CEDEX PA B1 PM PAVILLION DE BRETUEIL, F-92312 SEVRES CEDEX, FRANCE SN 0026-1394 J9 METROLOGIA JI Metrologia PD MAY PY 1996 VL 32 IS 6 BP 449 EP 453 DI 10.1088/0026-1394/32/6/9 PG 5 WC Instruments & Instrumentation; Physics, Applied SC Instruments & Instrumentation; Physics GA UU321 UT WOS:A1996UU32100009 ER PT J AU Tsai, BK Johnson, BC Saunders, RD Cromer, CL AF Tsai, BK Johnson, BC Saunders, RD Cromer, CL TI Comparison of filter radiometer spectral responsivity with the NIST spectral-irradiance and illuminance scales SO METROLOGIA LA English DT Article; Proceedings Paper CT 5th International Conference on Radiometry CY SEP 19-21, 1994 CL BERLIN, GERMANY SP Phys Tech Bundesanstalt AB Narrowband filter radiometers are being used in the development of a new method of irradiance scale realization at the National Institute of Standards and Technology (NIST). To improve the accuracy of the current spectral-irradiance scale, we propose to eliminate several steps from the calibration process and to use the filter radiometers and a high-temperature black body in realizing the scale. Ultimately, the filter radiometers will be calibrated against a trap detector measured at the NIST High Accuracy Cryogenic Radiometer, which maintains an expanded uncertainty at 633 nm of 0,0266% for a coverage factor of k = 2. In this work, the filter and detector were calibrated as a unit using the NIST Detector Comparator Facility, and the aperture areas were measured by flux comparison with a uniform source. Six filter radiometers covering the spectral range 350 nm to 1100 nm were used to measure a known irradiance source; the measurements agreed with predictions to within 1%. Comparisons were also conducted with three NIST standard photometers, and similar agreement was observed. Since the irradiance source and the photometers were calibrated using independent methods, our results not only verify the calibration of the filter radiometers but also imply that the NIST scales of spectral irradiance and illuminance are consistent. Future plans include characterization of a high-temperature black body and the calibration of quartz-halogen irradiance lamps using this black-body source. RP Tsai, BK (reprint author), NIST,RADIOMETR PHYS DIV,GAITHERSBURG,MD 20899, USA. NR 15 TC 13 Z9 13 U1 0 U2 0 PU BUREAU INT POIDS MESURES PI SEVRES CEDEX PA B1 PM PAVILLION DE BRETUEIL, F-92312 SEVRES CEDEX, FRANCE SN 0026-1394 J9 METROLOGIA JI Metrologia PD MAY PY 1996 VL 32 IS 6 BP 473 EP 477 DI 10.1088/0026-1394/32/6/14 PG 5 WC Instruments & Instrumentation; Physics, Applied SC Instruments & Instrumentation; Physics GA UU321 UT WOS:A1996UU32100014 ER PT J AU Migdall, AL Datla, RU Sergienko, A Orszak, JS Shih, YH AF Migdall, AL Datla, RU Sergienko, A Orszak, JS Shih, YH TI Absolute detector quantum-efficiency measurements using correlated photons SO METROLOGIA LA English DT Article; Proceedings Paper CT 5th International Conference on Radiometry CY SEP 19-21, 1994 CL BERLIN, GERMANY SP Phys Tech Bundesanstalt AB An experimental system using correlated photons for radiometric purposes has been set up at the National Institute of Standards and Technology (NIST). We use pairs of correlated photons to produce spatial maps of the absolute efficiency of a photomultiplier photocathode at four wavelengths. We also compare this technique with measurements carried out by conventional means tied to existing radiometric standards. These initial comparisons show an average agreement within similar to 0,6% between the two methods. The results show that correlated photons can be a useful tool in radiometry and that the method holds enough promise to warrant further studies. C1 UNIV MARYLAND,DEPT PHYS,BALTIMORE,MD 21228. RP Migdall, AL (reprint author), NIST,DIV RADIOMETR PHYS,221-B208,GAITHERSBURG,MD 20899, USA. NR 13 TC 22 Z9 24 U1 0 U2 0 PU BUREAU INT POIDS MESURES PI SEVRES CEDEX PA B1 PM PAVILLION DE BRETUEIL, F-92312 SEVRES CEDEX, FRANCE SN 0026-1394 J9 METROLOGIA JI Metrologia PD MAY PY 1996 VL 32 IS 6 BP 479 EP 483 PG 5 WC Instruments & Instrumentation; Physics, Applied SC Instruments & Instrumentation; Physics GA UU321 UT WOS:A1996UU32100015 ER PT J AU Gentile, TR Cromer, CL AF Gentile, TR Cromer, CL TI Mode-locked lasers for high-accuracy radiometry SO METROLOGIA LA English DT Article; Proceedings Paper CT 5th International Conference on Radiometry CY SEP 19-21, 1994 CL BERLIN, GERMANY SP Phys Tech Bundesanstalt ID PICOSECOND AB The use of a mode-locked laser as a source for high-accuracy calibration of transfer standards to a cryogenic radiometer is discussed. The critical issue is the relative response of the transfer standard to the mode-locked laser light as compared with continuous-wave laser light. As a first test, we have measured the linearity of the response of silicon photodiode light-trapping detectors using mode-locked laser light at a wavelength of 532 nm. RP Gentile, TR (reprint author), NIST,GAITHERSBURG,MD 20899, USA. NR 7 TC 2 Z9 2 U1 0 U2 0 PU BUREAU INT POIDS MESURES PI SEVRES CEDEX PA B1 PM PAVILLION DE BRETUEIL, F-92312 SEVRES CEDEX, FRANCE SN 0026-1394 J9 METROLOGIA JI Metrologia PD MAY PY 1996 VL 32 IS 6 BP 585 EP 587 PG 3 WC Instruments & Instrumentation; Physics, Applied SC Instruments & Instrumentation; Physics GA UU321 UT WOS:A1996UU32100037 ER PT J AU Lorentz, SR Ebner, SC Walker, JH Datla, RU AF Lorentz, SR Ebner, SC Walker, JH Datla, RU TI NIST low-background infrared spectral calibration facility SO METROLOGIA LA English DT Article; Proceedings Paper CT 5th International Conference on Radiometry CY SEP 19-21, 1994 CL BERLIN, GERMANY SP Phys Tech Bundesanstalt AB The goal of the Low-background Infrared (LBIR) calibration facility at the National Institute of Standards and Technology is to provide the infrared user community with a calibration base for broadband and spectral radiant power measurements. The LBIR facility began broadband radiant-flux calibrations of infrared sources in 1990 using a cryogenic vacuum chamber to provide the low background at 20 K. A second cryogenic-vacuum chamber is being brought into service for spectral calibrations in the LBIR facility. This new spectral calibration chamber will house the spectral instrument and be the centre for the spectral calibrations of sources and detectors and for the measurement of optical properties of materials. The LBIR spectral instrument is composed of a KRS-5 prism predisperser for order-sorting, followed by a grating monochromator. This calibration capability is currently being developed in three areas: spectral calibration of infrared detectors for use in low-background applications; spectral resolution of radiation from black-body sources such as cavities and other geometries such as spheres and plates; and characterization of optical components of interest to the community such as filters and window materials. This work will be carried out over the spectral range 2 mu m to 30 mu m. RP Lorentz, SR (reprint author), NIST,RADIOMETR PHYS DIV,GAITHERSBURG,MD 20899, USA. NR 4 TC 4 Z9 4 U1 1 U2 1 PU BUREAU INT POIDS MESURES PI SEVRES CEDEX PA B1 PM PAVILLION DE BRETUEIL, F-92312 SEVRES CEDEX, FRANCE SN 0026-1394 J9 METROLOGIA JI Metrologia PD MAY PY 1996 VL 32 IS 6 BP 621 EP 624 PG 4 WC Instruments & Instrumentation; Physics, Applied SC Instruments & Instrumentation; Physics GA UU321 UT WOS:A1996UU32100044 ER PT J AU Bridges, JM Migdall, AL AF Bridges, JM Migdall, AL TI Characterization of argon arc source in the infrared SO METROLOGIA LA English DT Article; Proceedings Paper CT 5th International Conference on Radiometry CY SEP 19-21, 1994 CL BERLIN, GERMANY SP Phys Tech Bundesanstalt AB A wall-stabilized are source is being investigated as a radiometric source for the near- and mid-infrared spectral range. This are is similar to the argon mini-are, which has been used as a radiometric source in the ultraviolet. The potential usefulness of the are in the infrared (IR) range stems from its high brightness in this region. The are has been tested as a source for a recently constructed facility for calibrating IR detectors. Over the range 3 mu m to 11 mu m, the signals with this source were greater by a factor of 6 to 17 than the signals from a 1500 K ceramic element, despite the beam from the are being smaller in angular extent. The radiance of the source was calibrated from 1,6 mu m to 10,6 mu m via a 1140 K black body. Over most of this spectral range the radiance of the are is equal to that of black bodies ranging in temperature from 5000 K to 10000 K. From 1 mu m to 3 mu m, a spectral scan with relatively high resolution shows a spectrum dominated by strong Ar I line emission. Finally, measurements were made of radiance as a function of are current and translational position of the source. RP Bridges, JM (reprint author), NIST,GAITHERSBURG,MD 20899, USA. NR 2 TC 6 Z9 6 U1 0 U2 5 PU BUREAU INT POIDS MESURES PI SEVRES CEDEX PA B1 PM PAVILLION DE BRETUEIL, F-92312 SEVRES CEDEX, FRANCE SN 0026-1394 J9 METROLOGIA JI Metrologia PD MAY PY 1996 VL 32 IS 6 BP 625 EP 628 PG 4 WC Instruments & Instrumentation; Physics, Applied SC Instruments & Instrumentation; Physics GA UU321 UT WOS:A1996UU32100045 ER PT J AU Ohno, Y Jackson, JK AF Ohno, Y Jackson, JK TI Characterization of modified FEL quartz-halogen lamps for photometric standards SO METROLOGIA LA English DT Article; Proceedings Paper CT 5th International Conference on Radiometry CY SEP 19-21, 1994 CL BERLIN, GERMANY SP Phys Tech Bundesanstalt ID SCALE AB The stability of luminous intensity and colour temperature of modified FEL-type, 1000W quartz-halogen lamps has been tested at various colour temperatures to investigate the suitability of these lamps for use as photometric transfer standards. During 60 h of operation at 2856 K, after seasoning for 100 h, the changes of luminous intensity of these lamps were 0,2 % to 0,6 %, and the changes of colour temperature were less than 2 K. The changes in relative spectral power distributions (normalized at 550 nm) over the 60 h of operation were within 0,5 % in the visible region. The FEL-type lamps operated at 2856 K showed satisfactory stability within the limited duration of these tests. Characteristics of the lamps have also been investigated for operation at 2000 K to 3100 K, for reversed polarity, and for long-term storage. RP Ohno, Y (reprint author), NIST,A305 B220,GAITHERSBURG,MD 20899, USA. NR 6 TC 6 Z9 6 U1 1 U2 1 PU BUREAU INT POIDS MESURES PI SEVRES CEDEX PA B1 PM PAVILLION DE BRETUEIL, F-92312 SEVRES CEDEX, FRANCE SN 0026-1394 J9 METROLOGIA JI Metrologia PD MAY PY 1996 VL 32 IS 6 BP 693 EP 696 DI 10.1088/0026-1394/32/6/60 PG 4 WC Instruments & Instrumentation; Physics, Applied SC Instruments & Instrumentation; Physics GA UU321 UT WOS:A1996UU32100060 ER PT J AU Rausch, RLM Smith, PJ AF Rausch, RLM Smith, PJ TI A diagnosis of a model-simulated explosively developing extratropical cyclone SO MONTHLY WEATHER REVIEW LA English DT Article ID QE-II STORM; TROPOPAUSE UNDULATIONS; POTENTIAL INSTABILITY; WESTERN ATLANTIC; JET STREAK; CYCLOGENESIS; EVOLUTION; EQUATION; INTENSIFICATION; PRESSURE AB This paper examines a simulation of the explosive development phase of the ERICA IOP 4 extratropical cyclone case obtained from the 70-km Limited Area Mesoscale Prediction System. A detailed diagnosis of the simulated cyclone is performed using the Zwack-Okossi equation to examine the forcing mechanisms influencing the near-surface synoptic-scale pressure tendency. The diagnosis includes two special features, the inclusion of forcing terms representing synoptic-subsynoptic exchange processes and a unique approach to evaluating the contribution of individual levels to the vertically integrated forcing. Explosive cyclogenesis was initiated by the combined effects of warm-air advection, cyclonic vorticity advection, and latent heat release, the first two maximizing above 400 mb and the latter below 750 mb. At the cyclone center the temperature advection profiles also featured a secondary warm-air advection maximum below 800 mb whose impact on surface pressure tendency was often equal to or greater than the upper-level maximum. The end of explosive development was signaled by a marked decrease in development rate that corresponded to a reversal in sign of the temperature advection contribution. Finally, subsynoptic processes contributed significantly through the synoptic-subsynoptic exchange of temperature. C1 PURDUE UNIV,DEPT EARTH & ATMOSPHER SCI,W LAFAYETTE,IN 47907. NOAA,NWS,NATL METEOROL CTR,CAMP SPRINGS,MD. NR 41 TC 18 Z9 19 U1 0 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 MAY PY 1996 VL 124 IS 5 BP 875 EP 904 DI 10.1175/1520-0493(1996)124<0875:ADOAMS>2.0.CO;2 PG 30 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA UJ178 UT WOS:A1996UJ17800007 ER PT J AU Shepherd, TR Rust, WD Marshall, TC AF Shepherd, TR Rust, WD Marshall, TC TI Electric fields and charges near 0 degrees C in stratiform clouds SO MONTHLY WEATHER REVIEW LA English DT Article ID MESOSCALE CONVECTIVE SYSTEM; MOBILE SOUNDING OBSERVATIONS; SQUALL-LINE; KINEMATIC STRUCTURE; MELTING LAYER; TEXAS STORM; PRECIPITATION; THUNDERSTORM; DRYLINE; RADAR AB Earlier studies of mesoscale convective system stratiform regions have shown that large electric fields and charge densities are found near the 0 degrees C level. Here 12 soundings of the electric field were analyzed through the 0 degrees C level in various types of electrified stratiform clouds. For each electric field sounding, the thermodynamic sounding and supporting radar data were also studied. For comparison, five soundings not from stratiform clouds were included. Charge densities were found at or near 0 degrees C in the stratiform clouds of at least 1 nC m(-3) in eight of the soundings, and four of those had charge densities of at least 2 nC m(-3). Of the stratiform soundings, Il had an electric field magnitude of greater than 50 kV m(-1) near 0 degrees C, and 7 of those had an electric field magnitude of at least 75 kV m(-1). The evidence suggests that melting may be the primary cause of the charge density found at and below 0 degrees C in electrified stratiform clouds. In all 12 of the stratiform soundings, positive charge density was found at or near 0 degrees C, and 11 of those had weaker negative charge density below. The evidence further suggests these two features do not exist in the absence of a bright band and (usually) an associated quasi-isothermal layer. C1 UNIV OKLAHOMA,COOPERAT INST MESOSCALE METEOROL STUDIES,NORMAN,OK 73019. UNIV MISSISSIPPI,DEPT PHYS & ASTRON,UNIVERSITY,MS 38677. RP Shepherd, TR (reprint author), NOAA,ENVIRONM RES LAB,NATL SEVERE STORMS LAB,1313 HALLEY CIRCLE,NORMAN,OK 73069, USA. NR 33 TC 51 Z9 51 U1 2 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 MAY PY 1996 VL 124 IS 5 BP 919 EP 938 DI 10.1175/1520-0493(1996)124<0919:EFACNI>2.0.CO;2 PG 20 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA UJ178 UT WOS:A1996UJ17800009 ER PT J AU Higgins, RW Mo, KC Schubert, SD AF Higgins, RW Mo, KC Schubert, SD TI The moisture budget of the central United States in spring as evaluated in the NCEP/NCAR and the NASA/DAO reanalyses SO MONTHLY WEATHER REVIEW LA English DT Article ID CONVECTION; SYSTEM AB The moisture budget of the central United States during May is examined using multiyear (1985-89) assimilated datasets recently produced by NASA/DAO and NCEP/NCAR. Intercomparisons and comparisons with station observations are used to evaluate the limitations of the assimilated products for studies of the atmospheric component of the U.S. hydrologic cycle. Attempts are made to reconcile differences in terms of disparities in the analysis systems. Both reanalyses overestimate daily mean precipitation rates by a factor of almost 2 over the southeastern United States. This is associated with much larger than observed afternoon convective rain and a substantial overestimate of the number of days with precipitation. Both products capture the transition to the much drier conditions over the western United States, though the NCEP/NCAR product extends moderate rain rates too far to the northwest. Over the Great Plains, the reanalyses capture observed synoptic-scale precipitation events quite well, but the variability of the daily mean precipitation is underestimated; this is particularly true for the NASA/ DAO analysis, which has difficulty capturing the extreme rain rates. The NCEP/NCAR product shows generally higher correlation's with the observed precipitation, though the fluctuations in the two assimilation products are more similar to each other than they are to the observations. The moisture transport in the reanalyses compares favorably to gridded rawinsonde data though there are some significant regional differences particularly along the Gulf Coast. Examination of the overall moisture budget for the central United States shows that the observations act as a significant local source of moisture, reflecting model bias in the first-guess fields. In both products the analysis increments act to remove water over much of the northern and western part of the country, apparently counteracting excessive evaporation in those regions, especially in the NASA/DAO. Perhaps most disturbing are the substantial differences between the two reanalyses in the moisture divergence fields since these are the most strongly constrained by the observations. Both reanalyses capture the basic temporal and structural characteristics of the Great Plains low-level jet (LLJ) documented in previous observational studies. Composites of the nocturnal fluxes of moisture during LLJ events reveal a horizontally confined region of strong southerly transport to the east of the Rocky Mountains that is sandwiched between well-defined synoptic-scale cyclonic (anticyclonic) circulations to the northwest (southeast). Low-level inflow from the Gulf of Mexico increases by more than 50% over nocturnal mean values in both reanalyses, though the excess inflow is more than 30% stronger in the NCEP/NCAR reanalysis. While both analyses underestimate the nocturnal maximum in precipitation over the Great Plains, the pattern of precipitation anomalies associated with LLJ events compares favorably to observations. C1 NASA,GODDARD LAB ATMOSPHERES,GREENBELT,MD. RP Higgins, RW (reprint author), NOAA,NWS,NCEP,CLIMATE PREDICT CTR,ANAL BRANCH,W-NP52,WORLD WEATHER BLDG,WASHINGTON,DC 20233, USA. NR 28 TC 75 Z9 78 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 MAY PY 1996 VL 124 IS 5 BP 939 EP 963 DI 10.1175/1520-0493(1996)124<0939:TMBOTC>2.0.CO;2 PG 25 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA UJ178 UT WOS:A1996UJ17800010 ER PT J AU vandenDool, HM Qin, J AF vandenDool, HM Qin, J TI An efficient and accurate method of continuous time interpolation of large-scale atmospheric fields SO MONTHLY WEATHER REVIEW LA English DT Article AB A method for time interpolation based on the climatological speed of large-scale atmospheric waves that is empirically determined is proposed. when rested on a 7-yr dataset this method is found to be easy to use, has good accuracy, and is, in fact, considerably more accurate than the much used linear time interpolation. The gain in accuracy is particularly large for mobile synoptic waves. Several applications of a time-continuous description of the atmosphere are discussed. C1 CLIMATE PREDICT CTR,WASHINGTON,DC. NR 11 TC 5 Z9 5 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 1996 VL 124 IS 5 BP 964 EP 971 DI 10.1175/1520-0493(1996)124<0964:AEAAMO>2.0.CO;2 PG 8 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA UJ178 UT WOS:A1996UJ17800011 ER PT J AU Hu, XH Liu, FP Baker, I Black, D AF Hu, XH Liu, FP Baker, I Black, D TI The effect of X-radiation on the plastic deformation of ice SO PHILOSOPHICAL MAGAZINE A-PHYSICS OF CONDENSED MATTER STRUCTURE DEFECTS AND MECHANICAL PROPERTIES LA English DT Article ID RAY TOPOGRAPHY; GRAIN-BOUNDARIES; DISLOCATIONS; VELOCITY; CRYSTALS AB The results of tensile tests on ice single crystals performed with and without Xray irradiation show that X-radiation does not measurably affect the creep deformation of ice. Therefore, the dislocation mobility and dislocation mechanisms observed by X-ray topography represent the intrinsic behaviour of ice. C1 NATL INST STAND & TECHNOL,US DEPT COMMERCE,GAITHERSBURG,MD 20899. RP Hu, XH (reprint author), DARTMOUTH COLL,THAYER SCH ENGN,HANOVER,NH 03755, USA. NR 32 TC 3 Z9 3 U1 0 U2 0 PU TAYLOR & FRANCIS LTD PI LONDON PA ONE GUNDPOWDER SQUARE, LONDON, ENGLAND EC4A 3DE SN 0141-8610 J9 PHILOS MAG A JI Philos. Mag. A-Phys. Condens. Matter Struct. Defect Mech. Prop. PD MAY PY 1996 VL 73 IS 5 BP 1355 EP 1361 PG 7 WC Materials Science, Multidisciplinary; Metallurgy & Metallurgical Engineering; Physics, Applied; Physics, Condensed Matter SC Materials Science; Metallurgy & Metallurgical Engineering; Physics GA UN307 UT WOS:A1996UN30700009 ER PT J AU Kildiyarova, RR Joshi, YN Sugar, J AF Kildiyarova, RR Joshi, YN Sugar, J TI Analysis of the 5d5f configuration of Os VII and Ir VIII SO PHYSICA SCRIPTA LA English DT Article AB The spectra of osmium and iridium were photographed in the 200-400 Angstrom region on a 3 m normal incidence and 10.7 m grazing incidence spectrographs. The light sources used were triggered and sliding sparks. The 5d(2)5d5f transitions in Os VII and Ir VIII were analysed. Eighteen of 20 levels of the 5d5f configuration in each spectrum have been established. Seventy-two lines of Os VII and 58 lines of Ir VIII have been classified. Least-squares fitted (LSF) and Hartree-Fock (HF) calculations were carried out to interpret the observed spectra. C1 RUSSIAN ACAD SCI,INST SPECT,TROITSK 142092,RUSSIA. NATL INST STAND & TECHNOL,GAITHERSBURG,MD 20899. RP Kildiyarova, RR (reprint author), ST FRANCIS XAVIER UNIV,DEPT PHYS,ANTIGONISH,NS B2G 2W5,CANADA. NR 6 TC 6 Z9 6 U1 1 U2 1 PU ROYAL SWEDISH ACAD SCIENCES PI STOCKHOLM PA PUBL DEPT BOX 50005, S-104 05 STOCKHOLM, SWEDEN SN 0281-1847 J9 PHYS SCRIPTA JI Phys. Scr. PD MAY PY 1996 VL 53 IS 5 BP 560 EP 564 DI 10.1088/0031-8949/53/5/010 PG 5 WC Physics, Multidisciplinary SC Physics GA UK731 UT WOS:A1996UK73100010 ER PT J AU Musielok, J Bridges, JM Djurovic, S Wiese, WL AF Musielok, J Bridges, JM Djurovic, S Wiese, WL TI Oscillator strengths for N II lines, including intersystem lines, and tests of the spectroscopic coupling scheme SO PHYSICAL REVIEW A LA English DT Article ID CARBON; SEQUENCE; LIFETIME AB We have measured the relative line strengths for a fairly large number of lines of the 3s-3p and 3p-3d transition arrays of N II with a wall-stabilized are source in order to test the quality of recent advanced atomic structure calculations. We have observed significant deviations from LS coupling for weaker 3p-3d lines and have found that our measurements agree much better with recent intermediate coupling results. Also, fairly strong intersystem, or spin-forbidden, lines occur for the N II ion due to a near coincidence of the 3s P-1(0) and 3s P-3(0) levels. We provide experimental comparison data for two recent calculations that differ by a factor of 2 for these intersystem lines. C1 OPOLE UNIV,PL-45052 OPOLE,POLAND. UNIV NOVI SAD,YU-21000 NOVI SAD,YUGOSLAVIA. RP Musielok, J (reprint author), NATL INST STAND & TECHNOL,GAITHERSBURG,MD 20899, USA. NR 15 TC 39 Z9 39 U1 0 U2 0 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 1050-2947 J9 PHYS REV A JI Phys. Rev. A PD MAY PY 1996 VL 53 IS 5 BP 3122 EP 3128 DI 10.1103/PhysRevA.53.3122 PG 7 WC Optics; Physics, Atomic, Molecular & Chemical SC Optics; Physics GA UK940 UT WOS:A1996UK94000033 ER PT J AU Geltman, S AF Geltman, S TI Laser-assisted collisions: The Kroll-Watson formula and bremsstrahlung theory SO PHYSICAL REVIEW A LA English DT Article ID FREE-FREE TRANSITIONS; MULTIPHOTON PROCESSES; ELECTRON-SCATTERING; PARTICLE SCATTERING; FIELD AB Recent measurements on CO2-laser-assisted electron-atom collisions have shown large inconsistencies with the Kroll-Watson formula for small-angle scattering. We have carried out a detailed study to compare the predictions of Kroll-Watson theory (for both single and multimode fields) with those of conventional perturbation theory for stimulated free-free transitions. It is found that for E(0)/2 omega(2) much less than 1, where perturbation theory is valid, there are large differences with the Kroll-Watson theory. Comparisons of experimental variations with respect to scattering angle and electron energy show much better agreement with perturbation theory than with Kroll-Watson theory. A study of the angular variations in perturbation theory shows that use of the ''outgoing'' wave final state gives much better agreement with experiment than does the ''ingoing'' wave final state, which is different from the choice made in early bremsstrahlung theory. C1 NIST,BOULDER,CO 80309. RP Geltman, S (reprint author), UNIV COLORADO,JOINT INST LAB ASTROPHYS,BOULDER,CO 80309, USA. NR 23 TC 29 Z9 30 U1 0 U2 0 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 1050-2947 J9 PHYS REV A JI Phys. Rev. A PD MAY PY 1996 VL 53 IS 5 BP 3473 EP 3483 DI 10.1103/PhysRevA.53.3473 PG 11 WC Optics; Physics, Atomic, Molecular & Chemical SC Optics; Physics GA UK940 UT WOS:A1996UK94000072 ER PT J AU Liu, WC Clark, CW AF Liu, WC Clark, CW TI Intensity dependence of the phase of harmonies in one- and two-frequency laser fields SO PHYSICAL REVIEW A LA English DT Article ID MULTIPHOTON IONIZATION; CM-2 SUPERCOMPUTER; PHYSICS; PLASMA; ATOM AB The phase relationship between an induced atomic dipole moment and a driving laser field is an essential aspect of high harmonic generation (HHG) in a dense medium. A ''phase-matching'' criterion must be fulfilled to obtain coherent amplification of harmonic radiation, which is critical for practical HHG. We have performed numerical calculations on model atoms to survey the intensity dependence of the phase in the case of strong one- or two-frequency laser fields. The calculations show that multiphoton resonances significantly affect the yield of harmonic generation and that in the ''plateau'' regime, the phases exhibit only weak dependence upon the intensity of the driving field. C1 UNIV MARYLAND,INST PHYS SCI & TECHNOL,COLLEGE PK,MD 20742. RP Liu, WC (reprint author), NATL INST STAND & TECHNOL,DIV ELECTRON & OPT PHYS,GAITHERSBURG,MD 20899, USA. RI Clark, Charles/A-8594-2009 OI Clark, Charles/0000-0001-8724-9885 NR 15 TC 7 Z9 7 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 PY 1996 VL 53 IS 5 BP 3582 EP 3586 DI 10.1103/PhysRevA.53.3582 PG 5 WC Optics; Physics, Atomic, Molecular & Chemical SC Optics; Physics GA UK940 UT WOS:A1996UK94000083 ER PT J AU Chen, HL Munro, RG AF Chen, HL Munro, RG TI Dependence of the critical temperature on atomic structure in orthorhombic YBa2Cu3Ox SO PHYSICAL REVIEW B LA English DT Article ID SUPERCONDUCTING TRANSITION-TEMPERATURE; NEUTRON POWDER DIFFRACTION; PRESSURE-DEPENDENCE; BULK SUPERCONDUCTOR; CRYSTAL-STRUCTURE; CHARGE-TRANSFER; OXYGEN; TC; Y1BA2CU3O7; OXIDES AB The method of parent compounds has been used to establish an approximate correlation between the variation of the critical temperature, T-c, and the variation of the potential difference, Delta V-A, of a hole at the apex and planar oxygen sites within the superconducting phase region of YBa2Cu3Ox. The resulting model was used to predict the pressure derivative of T-c under hydrostatic pressure, giving derivatives and standard uncertainties of dT(c)/dP=6.1+/-0.5 K/GPa for x=6.6 and dT(c)/dP=-0.6+/-0.3 K/GPa for x=6.93. RP Chen, HL (reprint author), NATL INST STAND & TECHNOL,DIV CERAM,GAITHERSBURG,MD 20899, USA. NR 32 TC 1 Z9 1 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 MAY 1 PY 1996 VL 53 IS 18 BP 12496 EP 12501 DI 10.1103/PhysRevB.53.12496 PG 6 WC Physics, Condensed Matter SC Physics GA UK932 UT WOS:A1996UK93200079 ER PT J AU Hobbie, EK Nakatani, AI Yajima, H Douglas, JF Han, CC AF Hobbie, EK Nakatani, AI Yajima, H Douglas, JF Han, CC TI Shear suppression of critical fluctuations in a diluted polymer blend SO PHYSICAL REVIEW E LA English DT Article ID LIGHT-SCATTERING; CRITICAL-DYNAMICS; CRITICAL FLUIDS; FLOW; MIXTURE; RENORMALIZATION AB Small-angle neutron scattering has been combined with equilibrium dynamic light scattering to study shear-induced mixing in a diluted high-molecular-weight polymer blend. The data show an enhancement of critical fluctuations upon dilution and are found to collapse onto a universal scaling curve containing no free parameters. This scaling curve is motivated by the theoretical predictions of Onuki and Kawasaki for undiluted binary mixtures. The data also appear to suggest that ''Fisher renormalization'' is relevant in this diluted pseudobinary polymer mixture, consistent with a previous dynamic-light-scattering study. RP NIST, DIV POLYMERS, GAITHERSBURG, MD 20899 USA. RI Hobbie, Erik/C-8269-2013 NR 25 TC 16 Z9 16 U1 1 U2 2 PU AMER PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 2470-0045 EI 2470-0053 J9 PHYS REV E JI Phys. Rev. E PD MAY PY 1996 VL 53 IS 5 BP R4322 EP R4325 PN A PG 4 WC Physics, Fluids & Plasmas; Physics, Mathematical SC Physics GA UM617 UT WOS:A1996UM61700018 ER PT J AU Lin, MY Hanley, HJM Sinha, SK Straty, GC Peiffer, DG Kim, MW AF Lin, MY Hanley, HJM Sinha, SK Straty, GC Peiffer, DG Kim, MW TI Shear-induced behavior in a solution of cylindrical micelles SO PHYSICAL REVIEW E LA English DT Article ID ANGLE NEUTRON-SCATTERING; FLUIDS AB The structure of cylindrical aqueous micellar solutions was studied by small angle neutron scattering and light scattering in equilibrium and under shear. In equilibrium, the micelles behave as randomly oriented, rigid cylinders with an exponential distribution of lengths. Under an applied shear, the micelles generally align as expected, but at a particular concentration, close to the overlap concentration, applied shear has little effect until a threshold shear rate is reached and then only after a time delay. The results are consistent with some aspects of recent kinetic theories for the association and breaking of micelle systems under shear flow. C1 EXXON RES & ENGN CO,ANNANDALE,NJ 08801. NATL INST STAND & TECHNOL,BOULDER,CO 80303. ARGONNE NATL LAB,ARGONNE,IL 60439. RI Kim, Mahn Won/C-1541-2011 NR 15 TC 19 Z9 19 U1 1 U2 2 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 1063-651X J9 PHYS REV E JI Phys. Rev. E PD MAY PY 1996 VL 53 IS 5 BP R4302 EP R4305 PN A PG 4 WC Physics, Fluids & Plasmas; Physics, Mathematical SC Physics GA UM617 UT WOS:A1996UM61700013 ER PT J AU Liverpool, TB Glotzer, SC AF Liverpool, TB Glotzer, SC TI Fixed-cluster acceleration algorithm for spin systems SO PHYSICAL REVIEW E LA English DT Article AB A recently introduced cluster acceleration algorithm for spin models [J. Machta et al., Phys. Rev. Lett. 75, 2792 (1995)] based on invasion percolation is generalized to temperatures away from the critical point using concepts of random bond percolation. The generalized algorithm is equivalent to an ''optimized'' version of the Swendsen-Wang cluster algorithm [R. H. Swendsen and J. S. Wang, Phys. Rev. Lett. 58, 86 (1987)], and we demonstrate its success and speed at all temperatures for the d=2 Ising model. We argue that the previously discussed connection to self-organized criticality may be viewed as one limit of the fixed-cluster algorithm. C1 NIST,MAT THEORY CTR,GAITHERSBURG,MD 20899. RP Liverpool, TB (reprint author), UNIV COLOGNE,INST THEORET PHYS,D-50937 COLOGNE,GERMANY. NR 8 TC 9 Z9 9 U1 0 U2 0 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 1063-651X J9 PHYS REV E JI Phys. Rev. E PD MAY PY 1996 VL 53 IS 5 BP R4255 EP R4258 PN A PG 4 WC Physics, Fluids & Plasmas; Physics, Mathematical SC Physics GA UM617 UT WOS:A1996UM61700001 ER EF