FN Thomson Reuters Web of Science™ VR 1.0 PT J AU Hayward, E AF Hayward, E TI Everett Gladding Fuller - Obituary SO PHYSICS TODAY LA English DT Item About an Individual RP Hayward, E (reprint author), NATL INST STAND & TECHNOL,GAITHERSBURG,MD 20899, USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU AMER INST PHYSICS PI WOODBURY PA CIRCULATION FULFILLMENT DIV, 500 SUNNYSIDE BLVD, WOODBURY, NY 11797-2999 SN 0031-9228 J9 PHYS TODAY JI Phys. Today PD MAY PY 1996 VL 49 IS 5 BP 88 EP 88 DI 10.1063/1.2807637 PG 1 WC Physics, Multidisciplinary SC Physics GA UJ660 UT WOS:A1996UJ66000022 ER PT J AU Desrosiers, MF AF Desrosiers, MF TI The use of alanine/boron mixtures in neutron dosimetry SO RADIATION RESEARCH LA English DT Letter RP Desrosiers, MF (reprint author), NIST,PHYS LAB,IONIZING RADIAT DIV,GAITHERSBURG,MD 20899, USA. NR 2 TC 0 Z9 0 U1 0 U2 0 PU RADIATION RESEARCH SOC PI OAK BROOK PA 2021 SPRING RD, STE 600, OAK BROOK, IL 60521 SN 0033-7587 J9 RADIAT RES JI Radiat. Res. PD MAY PY 1996 VL 145 IS 5 BP 651 EP 651 DI 10.2307/3579292 PG 1 WC Biology; Biophysics; Radiology, Nuclear Medicine & Medical Imaging SC Life Sciences & Biomedicine - Other Topics; Biophysics; Radiology, Nuclear Medicine & Medical Imaging GA UH191 UT WOS:A1996UH19100023 PM 8619037 ER PT J AU Mitchell, RM AF Mitchell, RM TI Preflight calibration anomaly in the NOAA 14 AVHRR channels 1 and 2 SO REMOTE SENSING OF ENVIRONMENT LA English DT Article ID SCATTERING AB Preflight calibration data for the visible and near-infrared channels of the NOAA 15 AVHRR suggests a kink in the response function at a reflectance of similar to 6% in Channel 1 and similar to 12% in Channel 2. Analysis of the ratio of the instrument's response in the two channels shows that this is an artifact of the preflight calibration performed in 1993, and not a genuine response anomaly. This effect may be explained by the entry of stray light from the integrating sphere into the instrument during the period when the space clamp target is viewed. The preflight operational calibration equations were based on this flawed data set. Fortunately, there is sufficient information to permit a recalibration. The revision leads to a reduction in reflectance for a given digital count value, by comparison with the published preflight calibration. The revision had significant consequences for low radiance applications such as the NOAA/NESDIS aerosol optical depth product, which showed anomalously high values during the first months of operation of NOAA 14. C1 NOAA,NATL ENVIRONM SATELLITE DATA & INFORMAT SERV,SATELLITE RES LAB,WASHINGTON,DC 20233. CSIRO,DIV ATMOSPHER RES,MORDIALLOC,VIC 3195,AUSTRALIA. NR 12 TC 3 Z9 4 U1 0 U2 1 PU ELSEVIER SCIENCE INC PI NEW YORK PA 655 AVENUE OF THE AMERICAS, NEW YORK, NY 10010 SN 0034-4257 J9 REMOTE SENS ENVIRON JI Remote Sens. Environ. PD MAY PY 1996 VL 56 IS 2 BP 141 EP 147 DI 10.1016/0034-4257(95)00232-4 PG 7 WC Environmental Sciences; Remote Sensing; Imaging Science & Photographic Technology SC Environmental Sciences & Ecology; Remote Sensing; Imaging Science & Photographic Technology GA UR751 UT WOS:A1996UR75100007 ER PT J AU Gillis, KA Mehl, JB Moldover, MR AF Gillis, KA Mehl, JB Moldover, MR TI Greenspan acoustic viscometer for gases SO REVIEW OF SCIENTIFIC INSTRUMENTS LA English DT Article AB Double Helmholtz acoustic resonators, first proposed by Greenspan for measuring the viscosity of gases, were tested with helium, argon, and propane. Two different resonators were tested extensively with all three gases. For each of these instruments, the results for the viscosities of the three gases were consistent within +/-0.5% at pressures spanning the range 25-1000 kPa. Without calibration, the viscosities deduced from one viscometer were systematically 1% larger than data from the literature; the viscosities from the second viscometer were systematically 3% larger than data from the literature. Ii the systematic differences were removed for each viscometer by calibration with a single gas at a single temperature and pressure, then nearly all the results for both instruments would have fallen within +/-0.5% of the data from the literature. In these viscometers, the test gases are in contact with robust metal parts only; thus, these instruments are applicable to a very wide variety of gases over a very wide range of temperatures. C1 NATL INST STAND & TECHNOL,DIV THERMOPHYS,GAITHERSBURG,MD 20899. UNIV DELAWARE,DEPT PHYS,NEWARK,DE 19716. RI Moldover, Michael/E-6384-2013 NR 14 TC 17 Z9 18 U1 1 U2 4 PU AMER INST PHYSICS PI WOODBURY PA CIRCULATION FULFILLMENT DIV, 500 SUNNYSIDE BLVD, WOODBURY, NY 11797-2999 SN 0034-6748 J9 REV SCI INSTRUM JI Rev. Sci. Instrum. PD MAY PY 1996 VL 67 IS 5 BP 1850 EP 1857 DI 10.1063/1.1146989 PG 8 WC Instruments & Instrumentation; Physics, Applied SC Instruments & Instrumentation; Physics GA UK828 UT WOS:A1996UK82800024 ER PT J AU Sorathia, U Lyon, R Gann, R Gritzo, L AF Sorathia, U Lyon, R Gann, R Gritzo, L TI Materials and fire threat SO SAMPE JOURNAL LA English DT Article C1 FAA,TECH CTR FIRE RES,ATLANTIC CITY INTL AIRPO,NJ. NATL INST STAND & TECHNOL,GAITHERSBURG,MD 20899. SANDIA NATL LABS,ALBUQUERQUE,NM 87185. RP Sorathia, U (reprint author), USN,CTR SURFACE WARFARE,CARDEROCK DIV,ANNAPOLIS,MD 21402, USA. NR 22 TC 29 Z9 29 U1 1 U2 2 PU SAMPE PUBLISHERS PI COVINA PA 1161 PARKVIEW DRIVE, COVINA, CA 91722 SN 0091-1062 J9 SAMPE J JI Sampe J. PD MAY-JUN PY 1996 VL 32 IS 3 BP 8 EP 15 PG 8 WC Engineering, Multidisciplinary; Materials Science, Multidisciplinary SC Engineering; Materials Science GA WT384 UT WOS:A1996WT38400003 ER PT J AU Gann, RG AF Gann, RG TI NIST research on less flammable materials SO SAMPE JOURNAL LA English DT Article AB A principal objective of the NIST Fire Research Program is supporting the development by U.S. manufacturers of a new generation of building and furnishing materials and products that contribute less to a fire, maintain their fire safety performance over the product life, and are environmentally friendly. This paper describes the NIST roles in fire safety science and engineering, as well as research projects currently underway on less fire-prone materials and products. RP Gann, RG (reprint author), NATL INST STAND & TECHNOL,BLDG & FIRE RES LAB,GAITHERSBURG,MD 20899, USA. NR 0 TC 0 Z9 1 U1 0 U2 0 PU SAMPE PUBLISHERS PI COVINA PA 1161 PARKVIEW DRIVE, COVINA, CA 91722 SN 0091-1062 J9 SAMPE J JI Sampe J. PD MAY-JUN PY 1996 VL 32 IS 3 BP 16 EP 20 PG 5 WC Engineering, Multidisciplinary; Materials Science, Multidisciplinary SC Engineering; Materials Science GA WT384 UT WOS:A1996WT38400004 ER PT J AU Wu, CC Chao, JK Wu, ST Dryer, M AF Wu, CC Chao, JK Wu, ST Dryer, M TI Numerical simulation of slow shocks in the solar wind SO SOLAR PHYSICS LA English DT Article ID INTERPLANETARY SPACE; WAVES; 1-AU; SUN; AU AB The evolutionary state of slow forward shock waves is examined with the use of two MHD numerical codes. Our study is intended to be exploratory rather than a detailed parametric one. The first code is one-dimensional (with three components of velocity and magnetic field) which is used to follow a slow shock that propagates into a positive gradient of density versus distance. It is found that the slow shock evolves into an extraneous (intermediate) shock wave. The second code has a spherical, one-dimensional, planar geometry (with two velocity and magnetic field components) which is used to follow a spiral interplanetary magnetic field. It is found that a slow shock type perturbation can generate a forward slow shock; a fast forward shock is generated in the front of the slow shock; a contact discontinuity is formed behind the slow shock, and a compound nonlinear MHD wave is formed behind the contact discontinuity with a fast reverse shock formed further behind. Thus, we demonstrate that the evolution of a slow shock into (solely) a fast shock, as suggested by Whang (1987), is much more complicated. C1 UNIV ALABAMA,CTR SPACE PLASMA & AERONOM RES,HUNTSVILLE,AL 35899. UNIV ALABAMA,DEPT MECH ENGN,HUNTSVILLE,AL 35899. NOAA,SPACE ENVIRONM LAB,BOULDER,CO 80303. UNIV COLORADO,COOPERAT INST RES ENVIRONM SCI,BOULDER,CO 80309. RP Wu, CC (reprint author), NATL CENT UNIV,INST SPACE SCI,CHUNGLI,TAIWAN. NR 31 TC 11 Z9 11 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 MAY PY 1996 VL 165 IS 2 BP 377 EP 393 DI 10.1007/BF00149720 PG 17 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA UD337 UT WOS:A1996UD33700010 ER PT J AU Seo, DJ AF Seo, DJ TI Nonlinear estimation of spatial distribution of rainfall - An indicator cokriging approach SO STOCHASTIC HYDROLOGY AND HYDRAULICS LA English DT Article DE rainfall estimation; indicator cokriging; rain gage measurements AB Indicator cokriging (Journel 1983) is examined as a tool for real-time estimation of rainfall from rain gage measurements. The approach proposed in this work obviates real-time estimation of real-time statistics of rainfall by using ensemble or climatological statistics exclusively, and reduces computational requirements attendant to indicator cokriging by employing only a few auxiliary cutoffs in estimation of conditional probabilities. Due to unavailability of suitable rain gage measurements, hourly radar rain fall data were used for both indicator covariance estimation and a comparative evaluation. Preliminary results suggest that the indicator cokriging approach is clearly superior to its ordinary kriging counterpart, whereas the indicator kriging approach is not. The improvement is most significant in estimation of light rainfall, but drops off significantly for heavy rainfall. The lack of predictability in spatial estimation of heavy rainfall is borne out in the integral scale of indicator correlation: peaking to its maximum for cutoffs near the median, indicator correlation scale becomes increasingly smaller for larger cutoffs of rainfall depth. A derived-distribution analysis, based on the assumption that radar rainfall is a linear sum of ground-truth and a random error, suggests that, at low cutoffs, indicator correlation scale of ground-truth can significantly differ from that of radar rainfall, and points toward inclusion of rainfall intermittency, for example, within the framework proposed in this work. RP Seo, DJ (reprint author), NATL WEATHER SERV,HYDROL RES LAB,SILVER SPRING,MD 20910, USA. NR 27 TC 21 Z9 21 U1 0 U2 4 PU SPRINGER VERLAG PI NEW YORK PA 175 FIFTH AVE, NEW YORK, NY 10010 SN 0931-1955 J9 STOCH HYDROL HYDRAUL JI Stoch. Hydrol. Hydraul. PD MAY PY 1996 VL 10 IS 2 BP 127 EP 150 DI 10.1007/BF01581763 PG 24 WC Engineering, Environmental; Engineering, Civil; Statistics & Probability; Water Resources SC Engineering; Mathematics; Water Resources GA UP603 UT WOS:A1996UP60300003 ER PT J AU Lovelace, C Collier, B Bohm, L Serafin, A Nackerdien, Z AF Lovelace, C Collier, B Bohm, L Serafin, A Nackerdien, Z TI Measurement of radiation and chemical-induced apoptosis in human cells. SO FASEB JOURNAL LA English DT Meeting Abstract C1 TREVIGEN INC,GAITHERSBURG,MD 20877. UNIV STELLENBOSCH,DEPT RADIOTHERAPY,TYGERBERG 7505,SOUTH AFRICA. NIST,DIV BIOTECHNOL,GAITHERSBURG,MD 20899. NR 0 TC 0 Z9 0 U1 0 U2 0 PU FEDERATION AMER SOC EXP BIOL PI BETHESDA PA 9650 ROCKVILLE PIKE, BETHESDA, MD 20814-3998 SN 0892-6638 J9 FASEB J JI Faseb J. PD APR 30 PY 1996 VL 10 IS 6 BP 58 EP 58 PG 1 WC Biochemistry & Molecular Biology; Biology; Cell Biology SC Biochemistry & Molecular Biology; Life Sciences & Biomedicine - Other Topics; Cell Biology GA UK861 UT WOS:A1996UK86100289 ER PT J AU Huey, LG AF Huey, LG TI The kinetics of the reactions of Cl-, O-, and O-2(-) with HNO3: Implications for measurement of HNO3 in the atmosphere SO INTERNATIONAL JOURNAL OF MASS SPECTROMETRY AND ION PROCESSES LA English DT Article DE chemical ionization; flowing afterglow; HNO3; ion/molecule reactions; rate coefficients ID IONIZATION MASS-SPECTROMETRY; LOWER STRATOSPHERE; NITRIC-ACID AB The rate coefficients for the reactions of O-, Cl-, and O-2(-) with HNO3 were measured to be (3.6 +/- 0.9), (2.8 +/- 0.7), and (2.9 +/- 0.8) x 10(-9) cm(3) molecule(-1) s(-1), respectively, at 295 K using the flowing afterglow technique. NO3- was the only product ion identified for each of these reactions. The measured rate coefficients for the O- and Cl- reactions are larger than previously reported. The implications of these results for active chemical ionization mass spectrometry (ACIMS) measurements of HNO3 in the upper atmosphere are discussed. RP Huey, LG (reprint author), NOAA,AERON LAB,R-E-AL2,325 BROADWAY,BOULDER,CO 80303, USA. NR 15 TC 7 Z9 7 U1 0 U2 3 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0168-1176 J9 INT J MASS SPECTROM JI Int. J. Mass Spectrom. Ion Process. PD APR 30 PY 1996 VL 153 IS 2-3 BP 145 EP 150 DI 10.1016/0168-1176(95)04354-3 PG 6 WC Physics, Atomic, Molecular & Chemical; Spectroscopy SC Physics; Spectroscopy GA UN035 UT WOS:A1996UN03500007 ER PT J AU Gille, JC Bailey, PL Massie, ST Lyjak, LV Edwards, DP Roche, AE Kumer, JB Mergenthaler, JL Gross, MR Hauchecorne, A Keckhut, P McGee, TJ McDermid, IS Miller, AJ Singh, U AF Gille, JC Bailey, PL Massie, ST Lyjak, LV Edwards, DP Roche, AE Kumer, JB Mergenthaler, JL Gross, MR Hauchecorne, A Keckhut, P McGee, TJ McDermid, IS Miller, AJ Singh, U TI Accuracy and precision of cryogenic limb array etalon spectrometer (CLAES) temperature retrievals SO JOURNAL OF GEOPHYSICAL RESEARCH-ATMOSPHERES LA English DT Article ID RESEARCH SATELLITE UARS; ATMOSPHERIC-TEMPERATURE; LIDAR; ROCKETSONDE; INTENSITIES; SOUTH; BANDS AB The Cryogenic Limb Array Etalon Spectrometer (CLAES) measured emission from the 792 cm(-1) Q branch of CO2, from which temperature distributions in the stratosphere and low mesosphere were derived, Here we briefly review the measurement technique, concentrating on aspects that affect the temperature determination, Comparison of many pairs of retrievals at the same location (near 32 degrees N or 32 degrees S) measured on sequential orbits (time separation of 96 min) shows a precision ranging from approximately 0.8 K at 68 mbar to about 3.5 K at 0.2 mbar, which agrees with simulations incorporating random noise and short-period spacecraft motions, Comparisons of globally analyzed CLAES data with National Meteorological Center (NMC) and U.K. Meteorological Office (UKMO) analyses show general agreement, with CLAES tending to be cooler by about 2 K, except in the tropics and high-latitude winter conditions. This is supported by comparisons with individual radiosondes and several lidars that indicate that the agreement is within 2 K throughout the profile (except for a narrow layer around 3 mbar). An error analysis also indicates that systematic errors should be roughly 2 K, independent of altitude, The systematic differences at low latitudes appear to be due to tropical waves, which have vertical wavelengths too short to be seen by the TIROS Operational Vertical Sounder (TOVS) instruments. There are no correlative rocketsondes or lidars to help resolve the reasons for the high-latitude differences. Comparisons with other Upper Atmosphere Research Satellite (UARS) data should shed additional light on this question. C1 HUGHES STX CORP, LANHAM, MD 20706 USA. CNRS, SERV AERON, F-91371 VERRIERES LE BUISSON, FRANCE. NOAA, NATL WEATHER SERV, NATL METEOROL CTR, CLIMATE ANAL CTR, WASHINGTON, DC 20233 USA. LOCKHEED PALO ALTO RES LABS, PALO ALTO, CA 94304 USA. NASA, GODDARD SPACE FLIGHT CTR, GREENBELT, MD 20771 USA. CALTECH, JET PROP LAB, PASADENA, CA 91109 USA. RP Gille, JC (reprint author), NATL CTR ATMOSPHER RES, POB 3000, BOULDER, CO 80307 USA. RI Hauchecorne, Alain/A-8489-2013; McGee, Thomas/G-4951-2013 NR 32 TC 31 Z9 31 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 APR 30 PY 1996 VL 101 IS D6 BP 9583 EP 9601 DI 10.1029/96JD00052 PG 19 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA UJ404 UT WOS:A1996UJ40400004 ER PT J AU Fishbein, EF Cofield, RE Froidevaux, L Jarnot, RF Lungu, T Read, WG Shippony, Z Waters, JW McDermid, IS McGee, TJ Singh, U Gross, M Hauchecorne, A Keckhut, P Gelman, ME Nagatani, RM AF Fishbein, EF Cofield, RE Froidevaux, L Jarnot, RF Lungu, T Read, WG Shippony, Z Waters, JW McDermid, IS McGee, TJ Singh, U Gross, M Hauchecorne, A Keckhut, P Gelman, ME Nagatani, RM TI Validation of UARS microwave limb sounder temperature and pressure measurements SO JOURNAL OF GEOPHYSICAL RESEARCH-ATMOSPHERES LA English DT Article ID ATMOSPHERIC-TEMPERATURE; MIDDLE ATMOSPHERE; LIDAR; MESOSPHERE; OXYGEN; WAVES; STRATOSPHERE; PROFILES; GRAVITY AB The accuracy and precision of the Upper Atmosphere Research Satellite (UARS) Microwave Limb Sounder (MLS) atmospheric temperature and tangent-point pressure measurements are described, Temperatures and tangent-point pressure (atmospheric pressure at the tangent height of the held of view boresight) are retrieved from a 15-channel 63-GHz radiometer measuring O-2 microwave emissions from the stratosphere and mesosphere, The Version 3 data (first public release) contains scientifically useful temperatures from 22 to 0.46 hPa, Accuracy estimates are based on instrument performance, spectroscopic uncertainty and retrieval numerics, and range from 2.1 K at 22 hPa to 4.8 K at 0.46 hPa for temperature and from 200 m (equivalent log pressure) at 10 hPa to 300 m at 0.1 hPa. Temperature accuracy is limited mainly by uncertainty in instrument characterization, and tangent-point pressure accuracy is limited mainly by the accuracy of spectroscopic parameters. Precisions are around 1 K and 100 m, Comparisons are presented among temperatures from MLS, the National Meteorological Center (NMC) stratospheric analysis and lidar stations at Table Mountain, California, Observatory of Haute Provence (OHP), France, and Goddard Spaceflight Center, Maryland. MLS temperatures tend to be 1-2 K lower than NMC and lidar, but MLS is often 5 - 10 K lower than NMC in the winter at high latitudes, especially within the northern hemisphere vortex. Winter MLS and OHP (44 degrees N) lidar temperatures generally agree and tend to be lower than NMC. Problems with Version 3 MLS temperatures and tangent-point pressures are identified, but the high precision of MLS radiances will allow improvements with better algorithms planned for the future. C1 HUGHES STX CORP, LANHAM, MD USA. NASA, GODDARD SPACE FLIGHT CTR, GREENBELT, MD 20771 USA. CNRS, SERV AERON, F-91371 VERRIERES LE BUISSON, FRANCE. NOAA, NATL WEATHER SERV, NATL CTR ENVIRONM PROTECT, CLIMATE PREDICT CTR, CAMP SPRINGS, MD USA. RP Fishbein, EF (reprint author), CALTECH, JET PROP LAB, 4800 OAK GROVE DR, PASADENA, CA 91109 USA. RI Hauchecorne, Alain/A-8489-2013; McGee, Thomas/G-4951-2013 NR 39 TC 43 Z9 43 U1 0 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 APR 30 PY 1996 VL 101 IS D6 BP 9983 EP 10016 DI 10.1029/95JD03791 PG 34 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA UJ404 UT WOS:A1996UJ40400022 ER PT J AU Froidevaux, L Read, WG Lungu, TA Cofield, RE Fishbein, EF Flower, DA Jarnot, RF Ridenoure, BP Shippony, Z Waters, JW Margitan, JJ McDermid, IS Stachnik, RA Peckham, GE Braathen, G Deshler, T Fishman, J Hofmann, DJ Oltmans, SJ AF Froidevaux, L Read, WG Lungu, TA Cofield, RE Fishbein, EF Flower, DA Jarnot, RF Ridenoure, BP Shippony, Z Waters, JW Margitan, JJ McDermid, IS Stachnik, RA Peckham, GE Braathen, G Deshler, T Fishman, J Hofmann, DJ Oltmans, SJ TI Validation of UARS microwave limb sounder ozone measurement SO JOURNAL OF GEOPHYSICAL RESEARCH-ATMOSPHERES LA English DT Article ID STRATOSPHERIC CLO; RETRIEVAL; OXYGEN; WINTER; MLS; O3 AB This paper describes the validation of ozone data from the Upper Atmosphere Research Satellite (UARS) Microwave Limb Sounder (MLS). The MLS ozone retrievals are obtained from the calibrated microwave radiances (emission spectra) in two separate bands, at frequencies near 205 and 183 GHz. Analyses described here focus on the MLS Version 3 data (the first set of files made publicly available). We describe results of simulations performed to assess the quality of the retrieval algorithms, in terms of both mixing ratio and radiance closure. From actual MLS observations, the 205-GHz ozone retrievals give better closure (smaller radiance residuals) than that from the 183-GHz measurements and should be considered more accurate from the calibration aspects. However, the 183-GHz data are less noise limited in the mesosphere and can provide the most useful scientific results in that region. We compare the retrieved 205-GHz ozone profiles in the middle-to lower stratosphere to ozonesonde measurements at a wide range of latitudes and seasons. Ground-based lidar data from Table Mountain, California, provide a good reference for comparisons at higher altitudes. Based on these analyses, comparisons with balloon-borne measurements and others, as well as a detailed budget of estimated uncertainties, MLS results appear to be generally of high quality, with some biases worth mentioning. Results for the lowermost stratosphere (similar to 50 to 100 hPa) are still in need of improvement. A set of estimated precision and accuracy values is derived for the MLS ozone data sets. We also comment on recent updates in the retrieval algorithms and their impact on ozone values. C1 NORSK INST LUFTFORSKNINH, OSLO, NORWAY. UNIV WYOMING, DEPT ATMOSPHER SCI, LARAMIE, WY 82071 USA. NASA, LANGLEY RES CTR, HAMPTON, VA 23681 USA. NOAA, CLIMATE MONITORING & DIAGNOST LAB, BOULDER, CO 80303 USA. HERIOT WATT UNIV, EDINBURGH EH14 4AS, MIDLOTHIAN, SCOTLAND. RP Froidevaux, L (reprint author), CALTECH, JET PROP LAB, 4800 OAK GROVE DR, MS 183-701, PASADENA, CA 91109 USA. NR 32 TC 106 Z9 106 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 APR 30 PY 1996 VL 101 IS D6 BP 10017 EP 10060 DI 10.1029/95JD02325 PG 44 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA UJ404 UT WOS:A1996UJ40400023 ER PT J AU Lahoz, WA Suttie, MR Froidevaux, L Harwood, RS Lau, CL Lungu, TA Peckham, GE Pumphrey, HC Read, WG Shippony, Z Suttie, RA Waters, JW Nedoluha, GE Oltmans, SJ Russell, JM Traub, WA AF Lahoz, WA Suttie, MR Froidevaux, L Harwood, RS Lau, CL Lungu, TA Peckham, GE Pumphrey, HC Read, WG Shippony, Z Suttie, RA Waters, JW Nedoluha, GE Oltmans, SJ Russell, JM Traub, WA TI Validation of UARS microwave limb sounder 183 GHz H2O measurements SO JOURNAL OF GEOPHYSICAL RESEARCH-ATMOSPHERES LA English DT Article ID MESOSPHERIC WATER-VAPOR; TEMPERATURE; VARIABILITY; ATMOSPHERE; RETRIEVAL; MIDDLE AB The Upper Atmosphere Research Satellite (UARS) microwave limb sounder (MLS) makes measurements of thermal emission at 183.3 GHz which are used to infer the concentration of water vapor over a pressure range of 46 - 0.2 hPa (similar to 20 to similar to 60 km). We provide a validation of MLS H2O by analyzing the integrity of the measurements, by providing an error characterization, and by comparison with data from other instruments. It is estimated that version 3 MLS H2O retrievals are accurate to within 20-25 % in the lower stratosphere and to within 8-13 % in the upper stratosphere and lower mesosphere, The precision of a single profile is estimated to be similar to 0.15 parts per million by volume (ppmv) in the midstratosphere and 0.2 ppmv in the lower and upper stratosphere, In the lower mesosphere the estimate of a single profile precision is 0.25-0.45 ppmv. During polar winter conditions, H2O retrievals at 46 hPa can have a substantial contribution from climatology. The vertical resolution of MLS H2O retrievals is similar to 5 km. C1 CALTECH, JET PROP LAB, PASADENA, CA 91109 USA. UNIV READING, DEPT METEOROL, CGAM, READING RG6 2AU, BERKS, ENGLAND. HERIOT WATT UNIV, DEPT PHYS, EDINBURGH EH14 4AS, MIDLOTHIAN, SCOTLAND. USN, RES LAB, WASHINGTON, DC 20375 USA. NASA, LANGLEY RES CTR, HAMPTON, VA 23665 USA. NOAA, CLIMATE MONITORING & DIAGNOST LAB, BOULDER, CO 80303 USA. HARVARD SMITHSONIAN CTR ASTROPHYS, CAMBRIDGE, MA 02138 USA. RP Lahoz, WA (reprint author), UNIV EDINBURGH, DEPT METEOROL, EDINBURGH EH9 3JZ, MIDLOTHIAN, SCOTLAND. NR 28 TC 36 Z9 36 U1 0 U2 0 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 2169-897X J9 J GEOPHYS RES-ATMOS JI J. Geophys. Res.-Atmos. PD APR 30 PY 1996 VL 101 IS D6 BP 10129 EP 10149 DI 10.1029/95JD01703 PG 21 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA UJ404 UT WOS:A1996UJ40400027 ER PT J AU Russell, JM Deaver, LE Luo, MZ Park, JH Gordley, LL Tuck, AF Toon, GC Gunson, MR Traub, WA Johnson, DG Jucks, KW Murcray, DG Zander, R Nolt, IG Webster, CR AF Russell, JM Deaver, LE Luo, MZ Park, JH Gordley, LL Tuck, AF Toon, GC Gunson, MR Traub, WA Johnson, DG Jucks, KW Murcray, DG Zander, R Nolt, IG Webster, CR TI Validation of hydrogen chloride measurements made by the halogen occultation experiment from the UARS platform SO JOURNAL OF GEOPHYSICAL RESEARCH-ATMOSPHERES LA English DT Article ID SPECTROSCOPIC MEASUREMENTS; TRACE GASES; HCL; HF; STRATOSPHERE; OZONE; ATMOSPHERE; ANTARCTICA; PINATUBO; O3 AB The Halogen Occultation Experiment (HALOE) on UARS uses the method of solar occultation limb sounding to measure the composition and structure of the stratosphere and mesosphere. One of the HALOE channels is spectrally centered at 3.4 mu m to measure the vertical profile and global distribution of hydrogen chloride. The mean difference between HALOE and 14 balloon correlative underflight measurements ranges from 8% to 19% throughout most of the stratosphere. This difference is within the limits of error bar overlap for the two data sets. The mean differences between HALOE and HCl data from ATMOS flights on the space shuttle is of the order of 15 to 20% for the 1992 flight and 10% for the 1993 flight. Generally, HALOE results tend to be low in these comparisons. Also, comparisons with two-dimensional model calculations and HALOE data are in good qualitative agreement regarding vertical profile shapes and features in a pressure versus latitude cross section. HCl values increase from similar to 0.3 parts per billion by volume (ppbv) to 1 ppbv in the lower stratosphere to 2.6 ppbv to 3.3 ppbv just above the stratopause which is the upper limit of HALOE single-profile measurements. There is a dependence of HCl results on the angle between the orbit plane and the Earth-Sun vector with HCl varying by +/-9% in the upper stratosphere. This variation appears to be altitude dependent and it is not discernible in the data below about 10 mbar. C1 UNIV CALIF IRVINE, DEPT EARTH SYST SCI, IRVINE, CA 92717 USA. G&A TECH SOFTWARE, HAMPTON, VA USA. NOAA, AERON LAB, BOULDER, CO 80303 USA. CALTECH, JET PROP LAB, PASADENA, CA USA. HARVARD SMITHSONIAN CTR ASTROPHYS, CAMBRIDGE, MA 02138 USA. UNIV DENVER, DENVER, CO 80210 USA. UNIV LIEGE, LIEGE, BELGIUM. NASA, LANGLEY RES CTR, AEROSP ELECT SYST DIV, HAMPTON, VA 23681 USA. RP Russell, JM (reprint author), NASA, LANGLEY RES CTR, DIV ATMOSPHER SCI, HAMPTON, VA 23681 USA. RI Tuck, Adrian/F-6024-2011 OI Tuck, Adrian/0000-0002-2074-0538 NR 40 TC 61 Z9 61 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 APR 30 PY 1996 VL 101 IS D6 BP 10151 EP 10162 DI 10.1029/95JD01696 PG 12 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA UJ404 UT WOS:A1996UJ40400028 ER PT J AU Harries, JE Russell, JM Tuck, AF Gordley, LL Purcell, P Stone, K Bevilacqua, RM Gunson, M Nedoluha, G Traub, WA AF Harries, JE Russell, JM Tuck, AF Gordley, LL Purcell, P Stone, K Bevilacqua, RM Gunson, M Nedoluha, G Traub, WA TI Validation of measurements of water vapor from the halogen occultation experiment (HALOE) SO JOURNAL OF GEOPHYSICAL RESEARCH-ATMOSPHERES LA English DT Article ID MIDDLE ATMOSPHERE; STRATOSPHERE; AEROSOL AB The Halogen Occultation Experiment (HALOE) experiment is a solar occultation limb sounder which operates between 2.45 and 10.0 mu m to measure the composition of the mesosphere, stratosphere, and upper troposphere. It flies onboard the Upper Atmosphere Research Satellite (UARS) which was launched in September 1991. Measurements are made of the transmittance of the atmosphere in a number of spectral channels as the Sun rises or sets behind the limb of the atmosphere. One of the channels, at 6.60 mu m, is a broadband filter channel tuned to detect absorption in the nu(2) band of water vapor. This paper describes efforts to validate the absolute and relative uncertainties (accuracy and precision) of the measurements from this channel. The HALOE data have been compared with independent measurements, using a variety of observational techniques, from balloons, from the ground, and from other space missions, and with the results of a two-dimensional model. The results show that HALOE is providing global measurements throughout the stratosphere and mesosphere with an accuracy within +/-10% over most of this height range, and to within +/-30% at the boundaries, and to a precision in the lower stratosphere of a few percent. The H2O data are combined with HALOE measurements of CH4 in order to test the data in terms of conservation of total hydrogen, with most encouraging results. The observed systematic behavior and internal consistency of the HALOE data, coupled with these estimates of their accuracy, indicate that the data may be used for quantitative tests of our understanding of the physical and chemical processes which control the concentration of H2O in the middle atmosphere. C1 USN, RES LAB, WASHINGTON, DC 20375 USA. G&A TECH SOFTWARE, HAMPTON, VA 23666 USA. CALTECH, JET PROP LAB, PASADENA, CA 91109 USA. NASA, LANGLEY RES CTR, DIV ATMOSPHER SCI, HAMPTON, VA 23861 USA. SMITHSONIAN ASTROPHYS OBSERV, CAMBRIDGE, MA 02138 USA. NOAA, AERON LAB, BOULDER, CO 80303 USA. RP Harries, JE (reprint author), UNIV LONDON IMPERIAL COLL SCI & TECHNOL, BLACKETT LAB, PRINCE CONSORT RD, LONDON SW7 2BZ, ENGLAND. RI Tuck, Adrian/F-6024-2011 OI Tuck, Adrian/0000-0002-2074-0538 NR 24 TC 135 Z9 136 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 APR 30 PY 1996 VL 101 IS D6 BP 10205 EP 10216 DI 10.1029/95JD02933 PG 12 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA UJ404 UT WOS:A1996UJ40400032 ER PT J AU Gordley, LL Russell, JM Mickley, LJ Frederick, JE Park, JH Stone, KA Beaver, GM McInerney, JM Deaver, LE Toon, GC Murcray, FJ Blatherwick, RD Gunson, MR Abbatt, JPD Mauldin, RL Mount, GH Sen, B Blavier, JF AF Gordley, LL Russell, JM Mickley, LJ Frederick, JE Park, JH Stone, KA Beaver, GM McInerney, JM Deaver, LE Toon, GC Murcray, FJ Blatherwick, RD Gunson, MR Abbatt, JPD Mauldin, RL Mount, GH Sen, B Blavier, JF TI Validation of nitric oxide and nitrogen dioxide measurements made by the halogen occultation experiment for UARS platform SO JOURNAL OF GEOPHYSICAL RESEARCH-ATMOSPHERES LA English DT Article ID LOWER THERMOSPHERE; STRATOSPHERIC NO2; O-3; CHEMISTRY; CLO AB The Halogen Occultation Experiment (HALOE) experiment on Upper Atmosphere Research Satellite (UARS) performs solar occultation (sunrise and sunset) measurements to infer the composition and structure of the stratosphere and mesosphere. Two of the HALOE channels, centered at 5.26 mu m and 6.25 mu m, are designed to infer concentrations of nitric oxide and nitrogen dioxide respectively. The NO measurements extend from the lower stratosphere up to 130 km, while the NO2 results typically range from the lower stratosphere to 50 km and higher near the winter terminator. Comparison with results from various instruments are presented, including satellite-, balloon-, and ground-based measurements. Both NO and NO2 can show large percentage errors in the presence of heavy aerosol concentrations, confined to below 25 km and before 1993. The NO2 measurements show mean differences with correlative measurements of about 10 to 15% over the middle stratosphere. The NO2 precision is about 7.5x10(-13) atm, degrading to 2x10(-12) atm in the lower stratosphere. The NO differences are similar in the middle stratosphere but sometimes show a low bias (as much as 35%) between 30 and 60 km with some correlative measurements. NO precision when expressed in units of density is nearly constant at 1x10(-12) atmospheres, or approximately 0.1 ppbv at 10.0 mb or, 1.0 ppbv at 1.0 mb, and so forth when expressed in mixing ratio. Above 65 km, agreement in the mean with Atmospheric Trace Molecule Spectroscopy (ATMOS) NO results is very good, typically +/- 15%. Model comparisons are also presented, showing good agreement with both expected morphology and diurnal behavior for both NO2 and NO. C1 UNIV CHICAGO, DEPT GEOPHYS SCI, CHICAGO, IL 60637 USA. UNIV DENVER, DENVER, CO 80208 USA. CALTECH, JET PROP LAB, PASADENA, CA 91109 USA. NASA, LANGLEY RES CTR, DIV ATMOSPHER SCI, HAMPTON, VA 23681 USA. NOAA, AERON LAB, BOULDER, CO 80303 USA. SCI APPLICAT INT CORP, HAMPTON, VA 23666 USA. RP Gordley, LL (reprint author), GATS INC, 28 RES DR, HAMPTON, VA 23666 USA. RI Mickley, Loretta/D-2021-2012 OI Mickley, Loretta/0000-0002-7859-3470 NR 38 TC 87 Z9 87 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 APR 30 PY 1996 VL 101 IS D6 BP 10241 EP 10266 DI 10.1029/95JD02143 PG 26 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA UJ404 UT WOS:A1996UJ40400034 ER PT J AU Hervig, ME Russell, JM Gordley, LL Drayson, SR Stone, K Thompson, RE Gelman, ME McDermid, IS Hauchecorne, A Keckhut, P McGee, TJ Singh, UN Gross, MR AF Hervig, ME Russell, JM Gordley, LL Drayson, SR Stone, K Thompson, RE Gelman, ME McDermid, IS Hauchecorne, A Keckhut, P McGee, TJ Singh, UN Gross, MR TI Validation of temperature measurements from the Halogen Occultation Experiment SO JOURNAL OF GEOPHYSICAL RESEARCH-ATMOSPHERES LA English DT Article ID LIDAR AB The Halogen Occultation Experiment (HALOE) onboard UARS measures profiles of limb path solar attenuation in eight infrared bands. These measurements are used to infer profiles of temperature, gas mixing ratios of seven species, and aerosol extinction at five wavelengths. The objective of this paper is to validate profiles of temperature retrieved from atmospheric transmission measurements in the 2.80-mu m CO2 band. Temperatures are retrieved fur levels above where aerosol affects the signals (35 km) to altitudes where the signal-to-noise decreases to unity (similar to 85 km). At altitudes from 45 to 35 km the profile undergoes a gradual transition from retrieved to National Meteorological Center (NMC) temperatures and below 35 km the profile is strictly from the NMC. This validation covers the uncertainty analysis, internal validations, and comparisons with independent measurements. Monte Carlo calculations using all known random and systematic errors determine typical measurement uncertainties of 5 K for altitudes below 80 km. Comparisons of coincident HALOE sunrise and sunset measurements are an indicator of the upper limit of measurement uncertainty. The sunrise-sunset comparisons have random and systematic differences which are less than 10 K for altitudes below 80 km. Comparisons of HALOE to lidar and rocket measurements typically have random differences of similar to 5 K for altitudes below 65 km. The mean differences for the correlative comparisons indicate that HALOE temperatures have a cold bias (2 to 5 K) in the upper stratosphere and stratopause. C1 UNIV MICHIGAN, DEPT SPACE PHYS, ANN ARBOR, MI 48109 USA. NOAA, NATL WEATHER SERV, WASHINGTON, DC 20233 USA. GATS INC, HAMPTON, VA 23666 USA. HUGHES STX, LANHAM, MD 20706 USA. CNRS, SERV AERON, F-91371 VERRIERES LE BUISSON, FRANCE. CALTECH, JET PROPULS LAB, TABLE MT FAC, PASADENA, CA 92397 USA. NASA, GODDARD SPACE FLIGHT CTR, GREENBELT, MD 20771 USA. NASA, LANGLEY RES CTR, DIV ATMOSPHER SCI, HAMPTON, VA 23681 USA. RP Hervig, ME (reprint author), UNIV WYOMING, DEPT ATMOSPHER SCI, POB 3038, LARAMIE, WY 82071 USA. RI Hauchecorne, Alain/A-8489-2013; McGee, Thomas/G-4951-2013 NR 13 TC 60 Z9 62 U1 0 U2 2 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 2169-897X J9 J GEOPHYS RES-ATMOS JI J. Geophys. Res.-Atmos. PD APR 30 PY 1996 VL 101 IS D6 BP 10277 EP 10285 DI 10.1029/95JD01713 PG 9 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA UJ404 UT WOS:A1996UJ40400036 ER PT J AU Keckhut, P Gelman, ME Wild, JD Tissot, F Miller, AJ Hauchecorne, A Chanin, ML Fishbein, EF Gille, J Russell, JM Taylor, FW AF Keckhut, P Gelman, ME Wild, JD Tissot, F Miller, AJ Hauchecorne, A Chanin, ML Fishbein, EF Gille, J Russell, JM Taylor, FW TI Semidiurnal and diurnal temperature tides (30-55 km): Climatology and effect on UARS-LIDAR data comparisons SO JOURNAL OF GEOPHYSICAL RESEARCH-ATMOSPHERES LA English DT Article ID EQUATORIAL MIDDLE ATMOSPHERE; RAYLEIGH LIDAR; SOLAR; VARIABILITY; ROCKETSONDE; MODEL; WAVES AB Very good agreement is shown for diurnal and semidiurnal temperature variations calculated from lidar measurements in southern France and from data of the microwave limb sounder of the Upper Atmosphere Research Satellite (UARS). Tides induce temperature deviations observed in southern France to be as large as +/-3 K, with a maximum at the stratopause. The amplitudes and phases of the semidiurnal variation change significantly with season and location. Seasonal changes up to 2 K have been clearly identified for the diurnal component. An analytic model of the diurnal component, based on sinusoidal functions, fits the data well, but is less successful for the semidiurnal component. Substantial agreement is also reported for the diurnal component between the results of our analytical model and the published results of a two-dimensional global-scale wave model. In contrast, the semidiurnal component is in total disagreement with numerical simulations that report very small amplitudes, as compared with the observations reported here. The confidence in detecting bias in data comparisons is improved if data used are limited to periods from April to September and if time-of-day adjustments are applied. Comparison between lidar and nearly coincident UARS temperature measurements have revealed, systematically, for the 4 experiments aboard UARS, a significant residual mean difference of up to 3 K around 35-43 km. A comparison using simultaneous measurements suggests that the bias is associated with the variability of migrating tides and/or the presence of nonmigrating tides rather than instrumental characteristics. C1 CALTECH, JET PROP LAB, MS 183 701, PASADENA, CA 91109 USA. NOAA, NATL WEATHER SERV, NATL METEOROL CTR, CLIMATE ANAL CTR, WASHINGTON, DC 20233 USA. NATL CTR ATMOSPHER RES, POB 3000, BOULDER, CO 80307 USA. NASA, LANGLEY RES CTR, MS 401B, HAMPTON, VA 23681 USA. UNIV OXFORD, OXFORD OX1 3PU, ENGLAND. RP Keckhut, P (reprint author), CNRS, SERV AERON, BP 3, F-91371 VERRIERES LE BUISSON, FRANCE. RI Hauchecorne, Alain/A-8489-2013 NR 33 TC 45 Z9 45 U1 0 U2 0 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 2169-897X J9 J GEOPHYS RES-ATMOS JI J. Geophys. Res.-Atmos. PD APR 30 PY 1996 VL 101 IS D6 BP 10299 EP 10310 DI 10.1029/96JD00344 PG 12 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA UJ404 UT WOS:A1996UJ40400038 ER PT J AU Manney, GL Swinbank, R Massie, ST Gelman, ME Miller, AJ Nagatani, R ONeill, A Zurek, RW AF Manney, GL Swinbank, R Massie, ST Gelman, ME Miller, AJ Nagatani, R ONeill, A Zurek, RW TI Comparison of UK Meteorological Office and US National Meteorological Center stratospheric analyses during northern and southern winter SO JOURNAL OF GEOPHYSICAL RESEARCH-ATMOSPHERES LA English DT Article ID POLAR VORTEX; TEMPERATURE; MLS AB Meteorological data from the United Kingdom Meteorological Office (UKMO), produced using a data assimilation system, and the U.S, National Meteorological Center (NMC), produced using an objective analysis procedure, are compared for dynamically active periods during the Arctic and Antarctic winters of 1992. The differences seen during these periods are generally similar to those seen during other winter periods. Both UKMO and NMC analyses capture the large-scale evolution of the stratospheric circulation during northern hemisphere (NH) and southern hemisphere (SH) winters, Stronger vertical and horizontal temperature gradients develop in the UKMO than in the NMC data during stratospheric warmings; comparison with satellite measurements with better vertical resolution suggests that the stronger vertical temperature gradients are more realistic. The NH polar vortex is slightly stronger in the UKMO analyses than in the NMC in the middle and upper stratosphere, and midstratospheric temperatures are slightly lower. The SH polar vortex as represented in the UKMO analyses is stronger and colder in the midstratosphere than its representation in the NMC analyses. The UKMO analyses on occasion exhibit some difficulties in representing cross-polar flow or changes in curvature of the wind field at very high latitudes. In addition to the above study of two wintertime periods, a more detailed comparison of lower-stratospheric temperatures is done for all Arctic and Antarctic winter periods since the launch of the Upper Atmosphere Research Satellite. In the NH lower stratosphere during winter, NMC temperatures are consistently lower than UKMO temperatures and closer to radiosonde temperatures than are UKMO temperatures. Conversely, in the SH lower stratosphere during winter, UKMO temperatures are typically lower than NMC and are closer to radiosonde temperature observations. C1 NOAA, NATL WEATHER SERV, NATL METEOROL CTR, WASHINGTON, DC 20233 USA. RP Manney, GL (reprint author), CALTECH, JET PROP LAB, 4800 OAK GROVE DR, MAIL STOP 183-701, PASADENA, CA 91109 USA. NR 25 TC 72 Z9 72 U1 1 U2 5 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 2169-897X J9 J GEOPHYS RES-ATMOS JI J. Geophys. Res.-Atmos. PD APR 30 PY 1996 VL 101 IS D6 BP 10311 EP 10334 DI 10.1029/95JD03350 PG 24 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA UJ404 UT WOS:A1996UJ40400039 ER PT J AU Pajares, A Wei, LH Lawn, BR Padture, NP Berndt, CC AF Pajares, A Wei, LH Lawn, BR Padture, NP Berndt, CC TI Mechanical characterization of plasma sprayed ceramic coatings on metal substrates by contact testing SO MATERIALS SCIENCE AND ENGINEERING A-STRUCTURAL MATERIALS PROPERTIES MICROSTRUCTURE AND PROCESSING LA English DT Article DE coatings; contact damage; delamination; fracture; indentation stress-strain curve; plasticity ID INDENTATION; DAMAGE AB Hertzian indentation testing is used to generate contact damage in plasma sprayed ceramic coatings on metal substrates. Two basic ceramic/metal coating/substrate systems are examined: alumina on steel and zirconia on superalloy. Macroscopic mechanical responses are measured via indentation stress-strain curves, which quantify the relative role of the coating and substrate in the net deformation and facilitate evaluations of elastic moduli and yield stresses. Micromechanical damage processes within the coating and substrate subsurface layers are studied using a ''bonded-interface'' specimen. Degradation occurs primarily by delamination and other cracking at the coating/substrate interface or in the coating, but plastic deformation of the metal substrate contributes importantly to the crack driving force. C1 UNIV CONNECTICUT, DEPT MET, STORRS, CT 06269 USA. UNIV CONNECTICUT, INST MAT SCI, STORRS, CT 06269 USA. SUNY STONY BROOK, DEPT MAT SCI & ENGN, STONY BROOK, NY 11794 USA. RP NIST, MAT SCI & ENGN LAB, GAITHERSBURG, MD 20899 USA. RI Padture, Nitin/A-9746-2009; Pajares, Antonia/I-3881-2015 OI Padture, Nitin/0000-0001-6622-8559; Pajares, Antonia/0000-0002-1086-7586 NR 27 TC 70 Z9 70 U1 2 U2 4 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 APR 30 PY 1996 VL 208 IS 2 BP 158 EP 165 DI 10.1016/0921-5093(95)10071-7 PG 8 WC Nanoscience & Nanotechnology; Materials Science, Multidisciplinary; Metallurgy & Metallurgical Engineering SC Science & Technology - Other Topics; Materials Science; Metallurgy & Metallurgical Engineering GA UR453 UT WOS:A1996UR45300002 ER PT J AU Slusser, J Hammond, K Kylling, A Stamnes, K Perliski, L Dahlback, A Anderson, D DeMajistre, R AF Slusser, J Hammond, K Kylling, A Stamnes, K Perliski, L Dahlback, A Anderson, D DeMajistre, R TI Comparison of air mass computations SO JOURNAL OF GEOPHYSICAL RESEARCH-ATMOSPHERES LA English DT Article ID ABSORPTION-SPECTROSCOPY; STRATOSPHERIC NO2; NEAR-ULTRAVIOLET; MCMURDO STATION; TWILIGHT; ANTARCTICA AB Knowledge of air mass is vital for the interpretation of twilight measurements of trace gases, as well as the conversion of measured slant column amounts to vertical abundances for comparison with model predictions. Radiative transfer computations were used to determine NO2 air mass values for clear skies at 450 and 650 nm using a discrete ordinate (two different formulations), Monte Carlo, and an integral equation method, All four methods yielded agreement to within 6% at a solar zenith angle of 90 degrees when the absorber was located in the stratosphere, For a tropospheric absorber, differences as large was 21% occurred at 90 degrees. Since only the Monte Carlo method treats the scattered radiation in spherical geometry, it is more accurate for computing tropospheric air masses where multiple scattering is significant. The other three models use a conceptual approximation by treating the scattered radiation in plane parallel geometry, However, for absorbers in the stratosphere, major saving of computing time without any loss of accuracy is obtained using the discrete ordinate or integral equation method as compared to the Monte Carlo method. C1 JOHNS HOPKINS UNIV, APPL PHYS LAB, LAUREL, MD 20723 USA. NORWEGIAN INST AIR RES, N-2007 KJELLER, NORWAY. UNIV ALASKA, INST GEOPHYS, FAIRBANKS, AK 99775 USA. GEOPHYS FLUID DYNAM LAB, PRINCETON, NJ 08542 USA. RI Kylling, Arve/B-1137-2017 OI Kylling, Arve/0000-0003-1584-5033 NR 23 TC 16 Z9 17 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 APR 27 PY 1996 VL 101 IS D5 BP 9315 EP 9321 DI 10.1029/96JD00054 PG 7 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA UJ130 UT WOS:A1996UJ13000001 ER PT J AU Chen, TC Pfaendtner, J Chen, JM Wikle, CK AF Chen, TC Pfaendtner, J Chen, JM Wikle, CK TI Variability of the global precipitable water with a timescale of 90-150 days SO JOURNAL OF GEOPHYSICAL RESEARCH-ATMOSPHERES LA English DT Article ID VAPOR AB A 90-150 day signal is identified in the global precipitable water field generated by the Global Data Assimilation Systems (GDAS) of the Goddard Laboratory for Atmospheres (GLA), National Meteorological Center, and European Centre for Medium-Range Weather Forecasts. The finding of this intraseasonal signal in global precipitable water is significant for two reasons: (1) it suggests that there is 90-150 day intraseasonal variability in the atmospheric branch of the global hydrological cycle and (2) it provides a useful parameter to test the sensitivity of the GDAS-generated hydrological data. This newly identified intraseasonal signal in the global precipitable water was verified with Special Sensor Microwave/Imager precipitable water data over oceans and station-mixing ratio data over the continental United States. Based upon some simple statistical analyses and global and regional composite charts, it was found that the 90-150 day low-frequency oscillations contained in different GDAS data sets are more coherent with each other in regions with good data coverage but are poorly correlated over the data-sparse areas. Furthermore, the GLA GDAS provides the most realistic representation of this intraseasonal global precipitable water signal. C1 NOAA, NATL METEOROL CTR, CAMP SPRINGS, MD 20446 USA. RP Chen, TC (reprint author), IOWA STATE UNIV SCI & TECHNOL, DEPT GEOL & ATMOSPHER SCI, ATMOSPHER SCI PROGRAM, AGRON HALL, AMES, IA 50011 USA. NR 17 TC 3 Z9 3 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 APR 27 PY 1996 VL 101 IS D5 BP 9323 EP 9332 DI 10.1029/95JD02369 PG 10 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA UJ130 UT WOS:A1996UJ13000002 ER PT J AU Soden, BJ Bretherton, FP AF Soden, BJ Bretherton, FP TI Interpretation of TOVS water vapor radiances in terms of layer-average relative humidities: Method and climatology for the upper, middle, and lower troposphere SO JOURNAL OF GEOPHYSICAL RESEARCH-ATMOSPHERES LA English DT Article AB This study presents an analytical expression, derived from radiative theory, for relating water vapor radiances to layer-average relative humidities. This ''radiance-to-humidity transformation'' provides a simple, yet reliable, means of interpreting satellite observations of the upwelling radiation in the 6.3-mu m water vapor absorption band in terms of a more familiar water vapor quantity. Despite its simplicity, when compared to detailed radiative transfer calculations of the upper (6.7 mu m) tropospheric water vapor radiance, the transformation is demonstrated to be accurate to within similar to 1 K. Similar levels of accuracy ate found when the transformation is compared to detailed calculations of the middle (7.3 mu m) and lower (8.3 mu m) tropospheric water vapor radiance, provided that the emission from the underlying surface is taken into account. On the basis of these results, the radiance-to-humidity transformation is used to interpret TIROS operational vertical sounder observed water vapor radiances in terms of the relative humidity averaged over deep layers of the upper, middle, and lower troposphere. We then present near-global maps of the geographic distribution and climatological variations of upper, middle, and lower-tropospheric humidity for the period 1981-1991. These maps clearly depict the role of the large-scale circulation in regulating the location and temporal variation of tropospheric water vapor. C1 UNIV WISCONSIN, CTR SPACE SCI & ENGN, MADISON, WI 53706 USA. RP Soden, BJ (reprint author), PRINCETON UNIV, NOAA, GEOPHYS FLUID DYNAM LAB, POB 308, PRINCETON, NJ 08542 USA. NR 20 TC 89 Z9 90 U1 0 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 APR 27 PY 1996 VL 101 IS D5 BP 9333 EP 9343 DI 10.1029/96JD00280 PG 11 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA UJ130 UT WOS:A1996UJ13000003 ER PT J AU Minschwaner, K Dessler, AE Elkins, JW Volk, CM Fahey, DW Loewenstein, M Podolske, JR Roche, AE Chan, KR AF Minschwaner, K Dessler, AE Elkins, JW Volk, CM Fahey, DW Loewenstein, M Podolske, JR Roche, AE Chan, KR TI Bulk properties of isentropic mixing into the tropics in the lower stratosphere SO JOURNAL OF GEOPHYSICAL RESEARCH-ATMOSPHERES LA English DT Article ID SOLAR-RADIATION; N2O; SPECTROMETER; LATITUDES; CLIMATE; CF2CL2; MODEL; CFCL3 AB Timescales for mixing of midlatitude air into the tropical lower stratosphere are deduced from observations of long-lived tracers N2O and CCl3F, Bulk mixing between tropical and midlatitude regions is assumed to be isentropic and relatively slow compared with local mixing within each region. The mean value of the mixing timescale ranges from 12 to 18 months near 20 km, There is a tendency for shorter mixing times at higher and lower altitudes, although vertical profiles of mixing cannot be definitively established by the data, A more robust quantity is given by the fraction of midlatitude air entrained into the tropical upwelling region, Implied mixing fractions exceed 50% above 22 km. C1 NASA, AMES RES CTR, MOFFETT FIELD, CA 94035 USA. NASA, GODDARD SPACE FLIGHT CTR, GREENBELT, MD 20771 USA. NOAA, CLIMATE MONITORING & DIAGNOST LAB, BOULDER, CO 80303 USA. NOAA, AERON LAB, BOULDER, CO 80303 USA. LOCKHEED PALO ALTO RES LABS, PALO ALTO, CA 94303 USA. RP Minschwaner, K (reprint author), NEW MEXICO INST MIN & TECHNOL, DEPT PHYS, SOCORRO, NM 87801 USA. RI Fahey, David/G-4499-2013; Dessler, Andrew/G-8852-2012 OI Fahey, David/0000-0003-1720-0634; Dessler, Andrew/0000-0003-3939-4820 NR 36 TC 68 Z9 67 U1 0 U2 2 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 2169-897X J9 J GEOPHYS RES-ATMOS JI J. Geophys. Res.-Atmos. PD APR 27 PY 1996 VL 101 IS D5 BP 9433 EP 9439 DI 10.1029/96JD00335 PG 7 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA UJ130 UT WOS:A1996UJ13000010 ER PT J AU Bacmeister, JT Eckermann, SD Newman, PA Lait, L Chan, KR Loewenstein, M Proffitt, MH Gary, BL AF Bacmeister, JT Eckermann, SD Newman, PA Lait, L Chan, KR Loewenstein, M Proffitt, MH Gary, BL TI Stratospheric horizontal wavenumber spectra of winds, potential temperature, and atmospheric tracers observed by high-altitude aircraft SO JOURNAL OF GEOPHYSICAL RESEARCH-ATMOSPHERES LA English DT Article ID ANTARCTIC OZONE EXPERIMENT; WAVE NUMBER SPECTRA; GRAVITY-WAVES; PERTURBATION SPECTRA; BALLOON OBSERVATIONS; ENERGY-DISSIPATION; LIDAR OBSERVATIONS; MESOSCALE MOTIONS; FREQUENCY-SPECTRA; MIDDLE ATMOSPHERE AB Horizontal wavenumber power spectra of vertical and horizontal wind velocities, potential temperatures, and ozone and N2O mixing ratios, as measured in the mid-stratosphere during 73 ER-2 flights (altitude approximate to 20 km) are presented. The velocity and potential temperature spectra in the 100 to 1-km wavelength range deviate significantly from the uniform -5/3 power law expected for the inverse energy-cascade regime of two-dimensional turbulence and also for inertial-range, three-dimensional turbulence. Instead, steeper spectra approximately consistent with a -3 power law are observed at horizontal scales smaller than 3 km for all velocity components as well as potential temperature. Shallower spectra are observed at scales longer than 6 km. For horizontal velocity and potential temperature the spectral indices at longer scales are between -1.5 and -2.0. For vertical velocity the spectrum at longer scales becomes flat. It is argued that the observed velocity and potential temperature spectra are consistent with gravity waves. At smaller scales, the shapes are also superficially consistent with a Lumley-Shur-Weinstock buoyant subrange of turbulence and/or nonlinear gravity waves. Contemporaneous spectra of ozone and N2O mixing ratio in the 100 to 1-km wavelength range do conform to an approximately uniform -5/3 power law. It is argued that this may reflect interactions between gravity wave air-parcel displacements and laminar or filamentary structures in the trace gas mixing ratio field produced by enstrophy-cascading two-dimensional turbulence. C1 NASA, AMES RES CTR, MOFFETT FIELD, CA 94035 USA. COMPUTAT PHYS INC, FAIRFAX, VA 22031 USA. NASA, JET PROP LAB, PASADENA, CA 91109 USA. NASA, GODDARD SPACE FLIGHT CTR, GREENBELT, MD 20771 USA. NOAA, AERON LAB, BOULDER, CO 80303 USA. RP Bacmeister, JT (reprint author), USN, RES LAB, WASHINGTON, DC 20375 USA. RI Newman, Paul/D-6208-2012 OI Newman, Paul/0000-0003-1139-2508 NR 99 TC 103 Z9 104 U1 2 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 APR 27 PY 1996 VL 101 IS D5 BP 9441 EP 9470 DI 10.1029/95JD03835 PG 30 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA UJ130 UT WOS:A1996UJ13000011 ER PT J AU Talukdar, RK Ravishankara, AR AF Talukdar, RK Ravishankara, AR TI Rate coefficients for O(D-1)+H-2, D-2, HD reactions and H atom yield in O(D-1)+HD reaction SO CHEMICAL PHYSICS LETTERS LA English DT Article ID REACTION DYNAMICS; RATE CONSTANTS; ENERGY; PHOTOLYSIS; O(1D); H-2; DEACTIVATION; SURFACES; O((1)D); H2O AB Rate coefficients, in units of 10(-10) cm(3) molecule(-1) s(-1), for the O(D-1) reactions with H-2, D-2 and HD at 298 K were determined to be 1.2 +/- 0.1, 1.1 +/- 0.1, and 1.2 +/- 0.1, respectively. The H atom yield in the O(D-1) + HD reaction, relative to that in the O(D-1)+ H-2 reaction, was measured to be 0.57 +/- 0.03. The temporal profiles of O(P-3) and H(S-2), following pulsed photolytic generation of O(D-1), were measured using cw resonance fluorescence detection to determine the rate coefficients and product yield. C1 UNIV COLORADO,COOPERAT INST RES ENVIRONM SCI,BOULDER,CO 80309. UNIV COLORADO,DEPT CHEM & BIOCHEM,BOULDER,CO 80309. RP Talukdar, RK (reprint author), NOAA,AERON LAB,325 BROADWAY,R-E-AL2,BOULDER,CO 80303, USA. RI TALUKDAR, RANAJIT/G-4530-2013; Ravishankara, Akkihebbal/A-2914-2011 OI TALUKDAR, RANAJIT/0000-0001-6017-8431; NR 26 TC 55 Z9 55 U1 2 U2 6 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 APR 26 PY 1996 VL 253 IS 1-2 BP 177 EP 183 DI 10.1016/0009-2614(96)00203-5 PG 7 WC Chemistry, Physical; Physics, Atomic, Molecular & Chemical SC Chemistry; Physics GA UK635 UT WOS:A1996UK63500031 ER PT J AU Xi, D Ramsdell, JS AF Xi, D Ramsdell, JS TI Glutamate receptors and calcium entry mechanisms for domoic acid in hippocampal neurons SO NEUROREPORT LA English DT Article DE domoic acid; neonate; hippocampus; glutamate receptors; free cytosolic calcium; calcium channels ID RAT DORSAL HIPPOCAMPUS; PYRAMIDAL NEURONS; KAINIC ACID; KAINATE; CHANNELS; PERMEABILITY; ACTIVATION; POISON; CELLS; NMDA AB DOMOIC acid (50 nM) elevates cytosolic free calcium ([Ca2+](i)) levels in 49% of the hippocampal pyramidal neurons isolated from postnatal day one (PND1) rats. This effect was prevented by 6-cyano-7-nitroquinoxaline-2,3-dione (CNQX; an antagonist of non-N-methyl-D-aspartate (NMDA) receptors, but not 2-amino-5-phosphonovaleric acid (AP-5; an antagonist of NMDA receptors). Domoic acid given at 5 mu M also elevated [Ca2+](i) levels in a second population (36%) of neurons in which the effect was only partially inhibited by 100 mu M CNQX. Nimodipine given at 300 nM prevented the elevation in [Ca2+](i) caused by 50 nM and 5 mu M domoic acid, indicating that domoic acid induced Ca2+ entry through type L voltage dependent calcium channels. These results provide evidence for at least two domoic acid-sensitive non-NMDA receptor subtypes in primary cultures of neonatal hippocampal pyramidal cells and indicate that voltage-dependent calcium channels are a primary calcium entry mechanism for domoic acid action. C1 US NATL MARINE FISHERIES SERV,MARINE BIOTOXINS PROGRAM,CHARLESTON,SC 29412. MED UNIV S CAROLINA,CHARLESTON,SC 29412. FU NIDDK NIH HHS [DK43107] NR 24 TC 30 Z9 31 U1 1 U2 4 PU RAPID SCIENCE PUBLISHERS PI LONDON PA 2-6 BOUNDARY ROW, LONDON, ENGLAND SE1 8NH SN 0959-4965 J9 NEUROREPORT JI Neuroreport PD APR 26 PY 1996 VL 7 IS 6 BP 1115 EP 1120 DI 10.1097/00001756-199604260-00002 PG 6 WC Neurosciences SC Neurosciences & Neurology GA VK184 UT WOS:A1996VK18400002 PM 8817513 ER PT J AU Shull, JM Stern, SA Thronson, HA AF Shull, JM Stern, SA Thronson, HA TI Detection and study of extrasolar terrestrial planets: Techniques and technology SO JOURNAL OF GEOPHYSICAL RESEARCH-PLANETS LA English DT Editorial Material C1 CASA,BOULDER,CO. SW RES INST,BOULDER DIV,BOULDER,CO 80302. UNIV WYOMING,DEPT PHYS & ASTRON,LARAMIE,WY 82071. RP Shull, JM (reprint author), UNIV COLORADO,NIST,JOINT INST LAB ASTROPHYS,DEPT ASTROPHYS PLANETARY & ATMOSPHER SCI,BOULDER,CO 80309, USA. RI Thronson, Harley/E-3382-2012 NR 3 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-PLANET JI J. Geophys. Res.-Planets PD APR 25 PY 1996 VL 101 IS E4 BP 9283 EP 9284 DI 10.1029/96JE00886 PG 2 WC Geochemistry & Geophysics SC Geochemistry & Geophysics GA UG926 UT WOS:A1996UG92600008 ER PT J AU Bender, PL Stebbins, RT AF Bender, PL Stebbins, RT TI Multiresolution-element imaging of extrasolar Earthlike planets SO JOURNAL OF GEOPHYSICAL RESEARCH-PLANETS LA English DT Article AB It has been suggested recently that imaging of extrasolar Earthlike planets should be considered as a possible future goal of the NASA space program. As an aid to discussing what would be required in order to undertake imaging, a partial design is described for a separated spacecraft interferometer which could achieve images in the visible with 10 resolution elements across the planet. Between 15 and 25 large collector telescopes or clusters of telescopes spread out over roughly a 200-km baseline in solar orbit at 1 AU from the Sun or possibly in high Earth orbit are required. A very preliminary approach to the use of multispectral remote sensing techniques is discussed also. Finally, the generalization of this approach to larger numbers of resolution elements across the planet is considered. Clearly, imaging is possible only if the truly staggering problem of avoiding the 10(10) times stronger scattered light from the nearby star can be overcome. However, even if this can be done, the amount and precision of the required hardware for even poor-quality images appears to present an obstacle to such a program which would be extremely difficult to overcome. RP Bender, PL (reprint author), UNIV COLORADO,NATL INST STAND & TECHNOL,JOINT INST LAB ASTROPHYS,CB 440,BOULDER,CO 80309, USA. RI Stebbins, Robin/G-5009-2013 NR 3 TC 6 Z9 6 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-PLANET JI J. Geophys. Res.-Planets PD APR 25 PY 1996 VL 101 IS E4 BP 9309 EP 9312 DI 10.1029/96JE00469 PG 4 WC Geochemistry & Geophysics SC Geochemistry & Geophysics GA UG926 UT WOS:A1996UG92600013 ER PT J AU Wenthold, PG Polak, ML Lineberger, WC AF Wenthold, PG Polak, ML Lineberger, WC TI Photoelectron spectroscopy of the allyl and 2-methylallyl anions SO JOURNAL OF PHYSICAL CHEMISTRY LA English DT Article ID GAS-PHASE; MULTIPHOTON IONIZATION; VIBRATIONAL ANALYSIS; BENZYL RADICALS; ATOMIC OXYGEN; SPECTRUM; STATES; BAND; PHOTODETACHMENT; CONSTANTS AB The electron affinities of allyl, allyl-d(5), 2-methylallyl, and 2-methylallyl-d(7) radicals have been determined from the 351 nm photoelectron spectra of the allylic anions. The ions were prepared in a cooled helium flow reactor by the reaction of O- with the corresponding propene. The electron affinities found for the radicals listed above are 0.481 +/- 0.008, 0.464 +/- 0.006, 0.505 +/- 0.006, and 0.493 +/- 0.008 eV, respectively. Extensive vibrational structure is observed in all the spectra, as the CCC bending and symmetric stretching modes are activated upon photodetachment. Vibrational frequencies for these modes are obtained for all of the radicals. A second harmonic of an asymmetric CH2 rocking mode is observed in the spectra of the allyl, allyl-d(5), and 2-methylallyl anions. Hot bands are used to determine the CCC bending frequencies in the allylic anions. Photoelectron angular distributions were measured for the allyl and 2-methylallyl anions. The photoelectron spectrum of allyl anion is calculated using a modeling procedure that utilizes the vibrational frequencies and geometries from nb initio calculations. This spectrum agrees very well with that obtained experimentally. The measured electron affinities are used together with the previously reported gas-phase acidities of propene and 2-methylpropene to determine the 298 K allylic C-H bond enthalpies for these hydrocarbons, with DH298(CH2CHCH2-H) = 88.8 +/- 0.4 kcal/mol and DH298(CH2C(CH3)CH2-H) = 88.3 +/- 2.3 kcal/mol. Methyl substitution at the 2-position of allyl radical is found to have little effect on any of the properties determined in this study. C1 UNIV COLORADO,NATL INST STAND & TECHNOL,JOINT INST LAB ASTROPHYS,BOULDER,CO 80309. UNIV COLORADO,DEPT CHEM & BIOCHEM,BOULDER,CO 80309. NR 56 TC 49 Z9 49 U1 2 U2 10 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 SN 0022-3654 J9 J PHYS CHEM-US JI J. Phys. Chem. PD APR 25 PY 1996 VL 100 IS 17 BP 6920 EP 6926 DI 10.1021/jp953401n PG 7 WC Chemistry, Physical SC Chemistry GA UG823 UT WOS:A1996UG82300009 ER PT J AU Manion, JA Tsang, W AF Manion, JA Tsang, W TI Hydrogen atom attack on 1,2-dichlorotetrafluoroethane: Rates of halogen abstraction SO JOURNAL OF PHYSICAL CHEMISTRY LA English DT Article ID PHASE AB Hydrogen atom attack on 1,2-dichlorotetrafluoroethane (DCFE) at temperatures between 970 and 1140 K and pressures of about 200-500 kPa (2-5 bar) has been studied with a single-pulse shock tube reactor. The observed products show that chlorine is readily abstracted, while fluorine is removed in at most trace quantities only. This is despite the greater exothermicity of the fluorine abstraction channel. Relative to the standard reaction of displacement of methyl from 1,3,5-trimethylbenzene, for which k[H + (CH3)(3)C6H3 --> (CH3)(2)C6H4 + CH3] = 6.7 x 10(13) exp(-3255/T) cm(3) mol(-1) s(-1), k(H + DCFE --> CF2CF2Cl + HCl) = 2.1 x 10(14) exp(-5839/T) cm(3) mol(-1) s(-1) and k(H + DCFE --> CFClCF2Cl + HF, 1100 K) less than or equal to 7 x 10(9) cm(3) mol(-1) s(-1). Uncertainties are estimated to be factors of 1.1 and 1.4 on relative and absolute bases, respectively. Comparisons with relevant literature data are made. The slow rate of F abstraction implies that reaction of fluorinated compounds via this pathway will be unimportant except in compounds unable to react via other channels. Implications with regard to the destruction of fluorinated compounds in pyrolytic and combustion systems are discussed. RP Manion, JA (reprint author), NATL INST STAND & TECHNOL,GAITHERSBURG,MD 20899, USA. NR 28 TC 8 Z9 8 U1 0 U2 0 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 SN 0022-3654 J9 J PHYS CHEM-US JI J. Phys. Chem. PD APR 25 PY 1996 VL 100 IS 17 BP 7060 EP 7065 DI 10.1021/jp9530109 PG 6 WC Chemistry, Physical SC Chemistry GA UG823 UT WOS:A1996UG82300027 ER PT J AU Grodkowski, J Neta, P Abdallah, Y Hambright, P AF Grodkowski, J Neta, P Abdallah, Y Hambright, P TI Reduction and alkylation of rhodium porphyrins in alcohol solutions. Radiation chemical and photochemical studies SO JOURNAL OF PHYSICAL CHEMISTRY LA English DT Article ID C-H BONDS; CARBON-MONOXIDE; OCTAETHYLPORPHYRIN HYDRIDE; AQUEOUS-SOLUTION; RH-C; COMPLEXES; RADICALS; DEHYDROGENATION; ACTIVATION; HYDROGEN AB Radiolytic reduction of chlororhodium(III) tetramesitylporphyrin ((ClRhP)-P-III) in alcohol solutions forms a transient (RhP)-P-II, which reacts to yield different products under different conditions. In alkaline 2-propanol the product is (RhP)-P-I-, in weakly acidic conditions (HRhP)-P-III is formed, and under strongly acidic conditions the main products of radiolysis are the alkylated rhodium complexes, R-(RhP)-P-III. The latter products are formed by reaction of (RhP)-P-II with alkyl radicals (R(.)) that are produced in the irradiated solvent (R(.) = (CH3)-C-. and (CH3)2(C)(.)OH in 2-propanol). UV photolysis of (ClRhP)-P-III in acetone/2-propanol solutions led to formation of HO(CH3)(2)C-(RhP)-P-III. One-electron reduction of CH3-(RhP)-P-III occurs at the porphyrin ligand to produce a transient pi-radical anion, CH3-(RhP.-)-P-III. In alkaline solution, this transient eliminates (.)CH3 to form the stable (RhP-)-P-I, but in neutral or acidic solutions, it undergoes disproportionation, promoted by protonation on the macrocycle, to form CH3-Rh-III-chlorin and then CH3-Rh-III-isobacteriochlorin upon further reduction. In the presence of CO2, the initial radiolytic reduction yields are increased. After extensive irradiation, however, the yields of reduction are decreased and a very low yield of CO was found. No reaction was detected between (RhP-)-P-I or (HRhP)-P-III and CO2, even under visible light illumination. Although this system is found to catalyze homogeneous photochemical formation of H-2, no catalytic activity for CO2 reduction was found under the current experimental conditions. C1 NATL INST STAND & TECHNOL,DIV CHEM KINET & THERMODYNAM,GAITHERSBURG,MD 20899. HOWARD UNIV,DEPT CHEM,WASHINGTON,DC 20059. NR 44 TC 3 Z9 3 U1 1 U2 5 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 SN 0022-3654 J9 J PHYS CHEM-US JI J. Phys. Chem. PD APR 25 PY 1996 VL 100 IS 17 BP 7066 EP 7071 DI 10.1021/jp953030a PG 6 WC Chemistry, Physical SC Chemistry GA UG823 UT WOS:A1996UG82300028 ER PT J AU Khaikin, GI Alfassi, ZB Huie, RE Neta, P AF Khaikin, GI Alfassi, ZB Huie, RE Neta, P TI Oxidation of ferrous and ferrocyanide ions by peroxyl radicals SO JOURNAL OF PHYSICAL CHEMISTRY LA English DT Article ID RATE CONSTANTS; ORGANIC REDUCTANTS; ELECTRON; POTENTIALS AB Alkylperoxyl and arylperoxyl radicals were produced by pulse radiolysis in aqueous solutions, and their reactions with ferrous and ferrocyanide ions were studied by kinetic spectrophotometry. Oxidation of Fe(CN)(6)(4-) took place with rate constants that varied from <1 x 10(5) to 5 x 10(7) L mol(-1) s(-1), depending on the electron-withdrawing effects of the substituents on the peroxyl radical and presumably reflecting variations in reduction potential of the peroxyl radical, as expected for outer-sphere electron transfer. Oxidation of Fe-aq(2+), on the other hand, took place by an inner-sphere mechanism controlled by the rate of dissociative interchange of the water ligand. The rate constants were nearly the same for all the peroxyl radicals examined (k = (0.5-1.1) x 10(6) L mol(-1) s(-1)) and involved the formation of a transient intermediate, RO(2)(-)Fe(3+), which later decomposed to yield Fe-aq(3+). The decomposition was accelerated by H+ and by Fe2+. The proposed mechanism is a modification of a previously suggested reaction scheme. C1 NATL INST STAND & TECHNOL,DIV CHEM KINET & THERMODYNAM,GAITHERSBURG,MD 20899. BEN GURION UNIV NEGEV,IL-84105 BEER SHEVA,ISRAEL. NR 27 TC 28 Z9 28 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 APR 25 PY 1996 VL 100 IS 17 BP 7072 EP 7077 DI 10.1021/jp9533335 PG 6 WC Chemistry, Physical SC Chemistry GA UG823 UT WOS:A1996UG82300029 ER PT J AU Anderson, DT Davis, S Nesbitt, DJ AF Anderson, DT Davis, S Nesbitt, DJ TI Probing hydrogen bond potentials via combination band spectroscopy: A near infrared study of the geared bend van der Waals stretch intermolecular modes in (HF)(2) SO JOURNAL OF CHEMICAL PHYSICS LA English DT Article ID QUASI-ADIABATIC CHANNELS; HF DIMER; VIBRATIONAL PREDISSOCIATION; HIGH-RESOLUTION; FLUORIDE DIMER; ENERGY SURFACE; INTRAMOLECULAR DYNAMICS; SPECTRA; ROTATION; COMPLEXES AB High resolution near infrared spectra of the two lowest frequency intermolecular modes in HF-stretch excited states of (HF), have been characterized using a slit-jet infrared spectrometer. In the spectral region surveyed, ten vibration-rotation-tunneling (VRT) bands are observed and assigned to the low frequency ''van der Waals stretch'' (nu(4)) and ''geared bend'' (nu(5)) intermolecular modes, in combination with either the hydrogen bond acceptor (nu(1)) or donor (nu(2)) high-frequency intramolecular HF stretches. Analysis of the rotationally resolved spectra provide intermolecular frequencies, rotational constants, tunneling splittings, and predissociation rates for the nu(4)/nu(5) intermolecular excited states. The intermolecular vibrational frequencies in the combination states display a systematic dependence on intramolecular redshift that allows far-IR intermolecular frequencies to be reliably extrapolated from the near-IR data. Approximately tenfold increases in the hydrogen bond interconversion tunneling splittings with either nu(4) or nu(5) excitation indicate that both intermolecular modes correlate strongly to the tunneling coordinate. The high resolution VRT line shapes reveal mode; specific predissociation broadening sensitive predominantly to intramolecular excitation, with weaker but significant additional effects due to low frequency intermolecular excitation. Analysis of the high resolution spectroscopic data for these nu(4) and nu(5) combination bands suggests strong state mixing between what has previously been considered van der Waals stretch and geared bend degrees of freedom. (C) 1996 American Institute of Physics. C1 UNIV COLORADO,NATL INST STAND & TECHNOL,BOULDER,CO 80309. UNIV COLORADO,DEPT CHEM & BIOCHEM,BOULDER,CO 80309. RP Anderson, DT (reprint author), UNIV COLORADO,JOINT INST LAB ASTROPHYS,BOULDER,CO 80309, USA. NR 67 TC 53 Z9 53 U1 1 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 APR 22 PY 1996 VL 104 IS 16 BP 6225 EP 6243 DI 10.1063/1.471285 PG 19 WC Chemistry, Physical; Physics, Atomic, Molecular & Chemical SC Chemistry; Physics GA UF447 UT WOS:A1996UF44700015 ER PT J AU Miller, AJ Hollandsworth, SM Flynn, LE Tiao, GC Reinsel, GC Bishop, L McPeters, RD Planet, WG DeLuisi, JJ Mateer, CL Wuebbles, D Kerr, J Nagatani, RM AF Miller, AJ Hollandsworth, SM Flynn, LE Tiao, GC Reinsel, GC Bishop, L McPeters, RD Planet, WG DeLuisi, JJ Mateer, CL Wuebbles, D Kerr, J Nagatani, RM TI Comparisons of observed ozone trends and solar effects in the stratosphere through examination of ground-based Umkehr and combined solar backscattered ultraviolet (SBUV) and SBUV 2 satellite data SO JOURNAL OF GEOPHYSICAL RESEARCH-ATMOSPHERES LA English DT Article ID NORTHERN-HEMISPHERE AB Within the past year, two papers have been published which present updated profile ozone trends from the recently revised ground-based Umkehr record [Miller et al., 1995] and the combined Nimbus 7 solar backscattered ultraviolet (SBUV) and NOAA 11 SBUV 2 satellite data record [Hollandsworth er al, 1995]. In this paper we compare the ozone trends and responses to the Ii-year solar cycle (represented by the F10.7 cm radio flux) derived from these two datasets for the period June 1977 to June 1991 (November 1978 to June 1991 for the satellite data), We consider data at northern midlatitudes (30 degrees-50 degrees N) at altitudes between 25 and 45 km derived from these two data sets. In particular, we investigate the effects of spatial sampling differences between the data sets on the derived signals. The trends derived from the two independent data sets are nearly identical at all levels except 35 km, where the Umkehr data indicate a somewhat more negative trend, The trend is approximately zero near 25 km but becomes more negative in the upper stratosphere, reaching nearly -7% per decade in the 40-45 km region, The upper stratospheric decreases are consistent with model results and are associated with the gas-phase chemical effect of chlorofluorocarbons CFC's and other ozone-destroying chemicals [World Meteorological Organization, 1995], The ozone correlations in the two data sets with the F10.7 cm solar flux are similar, with near-zero solar-induced ozone variations in the 25-30 km region and statistically significant in-phase variations at higher altitudes. Estimates of the solar cycle in the ozone time series at 40-45 km from a regression model indicate variations of about 4.5% from solar cycle maximum to minimum. Analysis of the satellite overpass data at the Umkehr station locations shows that the average of the data from the 11 Umkehr stations is a good approximation for the 30 degrees-50 degrees N zonal mean. C1 NOAA, ENVIRONM RES LAB, AIR RESOURCES LAB, BOULDER, CO 80303 USA. SOFTWARE CORP AMERICA, LANHAM, MD 20706 USA. NASA, GODDARD SPACE FLIGHT CTR, APPL RES CORP, GREENBELT, MD 20785 USA. ATMOSPHER ENVIRONM SERV, DOWNSVIEW, ON M3H 5T4, CANADA. NATL ENVIRONM SATELLITE DATA & INFORMAT SERV, OFF RES & APPLICAT, WASHINGTON, DC 20233 USA. UNIV WISCONSIN, DEPT STAT, MADISON, WI 53706 USA. UNIV CHICAGO, GRAD SCH BUSINESS, CHICAGO, IL 60637 USA. UNIV ILLINOIS, DEPT ATMOSPHER SCI, URBANA, IL 61801 USA. ALLIED SIGNAL INC, BUFFALO, NY 14210 USA. RP Miller, AJ (reprint author), NOAA, NATL WEATHER SERV, CLIMATE PREDICT CTR, WASHINGTON, DC 20233 USA. RI Flynn, Lawrence/B-6321-2009; McPeters, Richard/G-4955-2013 OI Flynn, Lawrence/0000-0001-6856-2614; McPeters, Richard/0000-0002-8926-8462 NR 20 TC 24 Z9 24 U1 0 U2 0 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 2169-897X J9 J GEOPHYS RES-ATMOS JI J. Geophys. Res.-Atmos. PD APR 20 PY 1996 VL 101 IS D4 BP 9017 EP 9021 DI 10.1029/96JD00229 PG 5 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA UG533 UT WOS:A1996UG53300003 ER PT J AU Nayak, AK Buckley, TJ Kurylo, MJ Fahr, A AF Nayak, AK Buckley, TJ Kurylo, MJ Fahr, A TI Temperature dependence of the gas and liquid phase ultraviolet absorption cross sections of HCPC-123 (CF3CHCl2) and HCFC-142b (CH3CF2Cl) SO JOURNAL OF GEOPHYSICAL RESEARCH-ATMOSPHERES LA English DT Article ID SCATTERED-LIGHT AB The absorption cross sections for HCFC-123 (CF3CHCl2) and HCFC-142b (CH3CF2Cl) have been measured in the gas and liquid phases over the temperature range of about 220-330 K. The liquid phase results were converted into effective gas phase cross sections using a wavelength shift procedure, thereby extending the gas phase cross sections to longer wavelengths. The results are compared with other available data and lend increased confidence in atmospheric lifetime calculations for these important industrial alternatives to the fully halogenated chlorofluorocarbons. RP Nayak, AK (reprint author), NIST, DIV CHEM KINET & THERMODYNAM, GAITHERSBURG, MD 20899 USA. RI Kurylo, Michael/H-2201-2012 NR 12 TC 6 Z9 6 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 APR 20 PY 1996 VL 101 IS D4 BP 9055 EP 9062 DI 10.1029/96JD00226 PG 8 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA UG533 UT WOS:A1996UG53300007 ER PT J AU Hanson, DR Ravishankara, AR Lovejoy, ER AF Hanson, DR Ravishankara, AR Lovejoy, ER TI Reaction of BrONO2 with H2O on submicron sulfuric acid aerosol and the implications for the lower stratosphere SO JOURNAL OF GEOPHYSICAL RESEARCH-ATMOSPHERES LA English DT Article ID TEMPERATURE; DEPENDENCE; KINETICS AB Uptake of BrONO2 onto submicron sulfuric acid aerosol was studied in a cylindrical flow reactor coupled to a chemical ionization mass spectrometer. On aerosol particles of similar to 0.1 mu m radius, the reaction of BrONO2 with H2O to produce HOBr and HNO3 is very efficient, with the reaction probability gamma approximate to 0.8 for H2SO4-content less than or equal to 70 wt%. The equilibrium constant for the gas phase process, BrONO2 + H2O reversible arrow HOBr + HNO3, was measured and the heats of formation of the bromine compounds were deduced. The conversion of HOBr back into BrONO2 via reaction with HNO3 can be neglected in the stratosphere. The heterogeneous hydrolysis of BrONO2, followed by photolysis of the HOBr product, is a major source of HOx in the lower stratosphere. The role of bromine as an activator of chlorine is also discussed. C1 NOAA, AERON LAB, BOULDER, CO 80303 USA. RI Ravishankara, Akkihebbal/A-2914-2011 NR 38 TC 103 Z9 106 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 APR 20 PY 1996 VL 101 IS D4 BP 9063 EP 9069 DI 10.1029/96JD00347 PG 7 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA UG533 UT WOS:A1996UG53300008 ER PT J AU Braden, BC Fields, BA Ysern, X Goldbaum, FA DallAcqua, W Schwarz, FP Poljak, RJ Mariuzza, RA AF Braden, BC Fields, BA Ysern, X Goldbaum, FA DallAcqua, W Schwarz, FP Poljak, RJ Mariuzza, RA TI Crystal structure of the complex of the variable domain of antibody D1.3 and turkey egg white lysozyme: A novel conformational change in antibody CDR-L3 selects for antigen SO JOURNAL OF MOLECULAR BIOLOGY LA English DT Article DE monoclonal antibody; protein structure; antibody-antigen interaction; X-ray diffraction; CDR conformation AB The crystal structure of the Fv fragment of the murine monoclonal anti-lysozyme antibody D1.3, complexed with turkey egg-white lysozyme (TEL), is presented. D1.3 (IgG1, kappa) is a secondary response antibody specific for hen egg-white lysozyme (HEL). TEL and HEL are homologous and differ in amino acid sequence in the antibody-antigen interface only at position 121. The side-chain of HEL residue Gln121 makes a pair of hydrogen bonds to main-chain atoms of the antibody light chain. In the D1.3-TEL structure, TEL residue His121 makes only one hydrogen bond with the light chain as a result of 129 degrees and 145 degrees change in peptide torsion angles for residues Trp92 and Ser93. Probably as a consequence of this conformational change, the D1.3-TEL association occurs at a much slower rate than the D1.3-HEL association. The D1.S-TEL complex is destabilized with respect to the D1.3-HEL interaction by the loss of two hydrogen bonds, exclusively due to the substitution of histidine for glutamine. While antibodies of secondary responses are indeed highly specific for antigen, this work demonstrates that by undergoing subtle conformational change antibodies can still recognize mutated protein antigens, albeit at a cost to affinity. (C) 1996 Academic Press Limited C1 NATL INST STAND & TECHNOL,ROCKVILLE,MD 20850. US FDA,CTR DRUG EVALUAT & RES,ROCKVILLE,MD 20857. RP Braden, BC (reprint author), UNIV MARYLAND,MARYLAND BIOTECHNOL INST,CTR ADV RES BIOTECHNOL,ROCKVILLE,MD 20850, USA. FU NIGMS NIH HHS [GM52801] NR 29 TC 33 Z9 33 U1 0 U2 0 PU ACADEMIC PRESS LTD PI LONDON PA 24-28 OVAL RD, LONDON, ENGLAND NW1 7DX SN 0022-2836 J9 J MOL BIOL JI J. Mol. Biol. PD APR 19 PY 1996 VL 257 IS 5 BP 889 EP 894 DI 10.1006/jmbi.1996.0209 PG 6 WC Biochemistry & Molecular Biology SC Biochemistry & Molecular Biology GA UG014 UT WOS:A1996UG01400001 PM 8632472 ER PT J AU Boix, E Wu, YN Vasandani, VM Saxena, SK Ardelt, W Ladner, J Youle, RJ AF Boix, E Wu, YN Vasandani, VM Saxena, SK Ardelt, W Ladner, J Youle, RJ TI Role of the N terminus in RNase a homologues: Differences in catalytic activity, ribonuclease inhibitor interaction and cytotoxicity SO JOURNAL OF MOLECULAR BIOLOGY LA English DT Article DE human pancreatic RNase; Rana pipiens RNase; pyroglutamic acid; ribonuclease inhibitor; cytotoxicity ID BOVINE PANCREATIC RIBONUCLEASE; HUMAN PLACENTAL RIBONUCLEASE; AMINO-ACID-SEQUENCE; C-PEPTIDE HELIX; SEMINAL RIBONUCLEASE; LIVER RIBONUCLEASE; RANA-CATESBEIANA; P-30 PROTEIN; ANGIOGENIN; SUPERFAMILY AB A number of biochemical properties differ dramatically among homologues within the pancreatic ribonuclease superfamily Human pancreatic ribonuclease (hRNase) has high enzyme activity, extreme sensitivity to ribonuclease inhibitor (RI) and is non-toxic, whereas a homologous RNase from frog eggs, called onconase, has much lower enzyme activity, is not sensitive to RI and is cytotoxic to cancer cell lines and animals. To explore the structural basis of these differences among members in the RNase family we synthesized genes for onconase, hRNase, a mutant onconase (K9Q) and onconase-hRNase N-terminal hybrids and expressed the proteins in Escherichia coli with final yields of 10 to 50 mg per liter of culture after purification. A recombinant version of onconase with an N-terminal methionine instead of the native pyroglutamyl residue had decreased cytotoxicity and enzyme activity. Cleavage of the recombinant onconase Met-1 residue, and cyclization of the Gln1 residue to reform the pyroglutamyl N terminus, reconstituted cytotoxicity and enzyme activity Thus a unique role of the pyroglutamyl residue in the active site of amphibian RNases is indicated. Replacement of one to nine residues of onconase with the homologous residues of hRNase increased the enzymatic activity against most of the substrates tested with a simultaneous shift in the enzyme specificity from high preference for poly(U) to slight preference for poly(C). Cytotoxicity of the chimera decreased, dissociating cytotoxicity from enzymatic activity: The molecular basis for the low binding affinity of onconase for RI has been examined experimentally with the recombinant RNases and by fitting onconase and RNase A structures to the coordinates from the recently published RNase A-RI complex. (C) 1996 Academic Press Limited C1 NINCDS,BIOCHEM SECT,SURG NEUROL BRANCH,NIH,BETHESDA,MD 20892. ALFACELL CORP,BLOOMFIELD,NJ 07003. UNIV MARYLAND,MARYLAND BIOTECHNOL INST,CTR ADV RES BIOTECHNOL,ROCKVILLE,MD 20850. NATL INST STAND & TECHNOL,ROCKVILLE,MD 20850. RI Boix, Ester/B-9038-2012; OI Boix, Ester/0000-0003-1790-2142; Saxena, Shailendra K/0000-0003-2856-4185 NR 77 TC 164 Z9 168 U1 2 U2 6 PU ACADEMIC PRESS LTD PI LONDON PA 24-28 OVAL RD, LONDON, ENGLAND NW1 7DX SN 0022-2836 J9 J MOL BIOL JI J. Mol. Biol. PD APR 19 PY 1996 VL 257 IS 5 BP 992 EP 1007 DI 10.1006/jmbi.1996.0218 PG 16 WC Biochemistry & Molecular Biology SC Biochemistry & Molecular Biology GA UG014 UT WOS:A1996UG01400010 PM 8632481 ER PT J AU Hanson, DR Lovejoy, ER AF Hanson, DR Lovejoy, ER TI Heterogeneous reactions in liquid sulfuric acid: HOCl+HCl as a model system SO JOURNAL OF PHYSICAL CHEMISTRY LA English DT Article ID MASS ACCOMMODATION COEFFICIENT; STRATOSPHERIC TEMPERATURES; AQUEOUS SURFACES; NITRIC-ACID; HCL; N2O5; DROPLETS; OZONE; WATER; HNO3 AB We describe detailed studies of the interaction of HCl and HOCl with 60 wt % liquid sulfuric acid at 251-276 K as an example of research aimed at understanding the heterogeneous chemistry of the stratosphere. The theory of gas/particle kinetics coupled with measurements of the uptake of HCl and HOCl by bulk and particulate 60 wt % sulfuric acid yield the solubilities of HCl and HOCl, the HCl and HOCl mass accommodation coefficients, the HCl + HOCl liquid-phase rate coefficient, and the HOCl liquid-phase diffusion coefficient. These results are in very good agreement with theoretical predictions and extrapolations of other independent results. C1 UNIV COLORADO,COOPERAT INST RES ENVIRONM SCI,BOULDER,CO 80309. RP Hanson, DR (reprint author), NOAA,AERON LAB,325 BROADWAY,BOULDER,CO 80303, USA. NR 49 TC 65 Z9 65 U1 0 U2 3 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 SN 0022-3654 J9 J PHYS CHEM-US JI J. Phys. Chem. PD APR 18 PY 1996 VL 100 IS 16 BP 6397 EP 6405 DI 10.1021/jp953250o PG 9 WC Chemistry, Physical SC Chemistry GA UF879 UT WOS:A1996UF87900009 ER PT J AU Mautner, MMN Sieck, LW Liebman, JF Scheiner, S AF Mautner, MMN Sieck, LW Liebman, JF Scheiner, S TI Complexing of the ammonium ion by polyethers. Comparative complexing thermochemistry of ammonium, hydronium, and alkali cations SO JOURNAL OF PHYSICAL CHEMISTRY LA English DT Article ID GAS-PHASE; CROWN ETHERS; THERMAL-DECOMPOSITION; PROTON AFFINITIES; POTASSIUM-ION; HYDROGEN-BOND; MOLECULES; ENERGIES; STABILITIES; EQUILIBRIA AB The binding energies of NH4+ to polyethers, and for comparison, to acetone molecules, were measured by pulsed high-pressure mass spectrometry. The binding energies in the polydentate complexes increase with increasing ligand size and number of available oxygen groups. However, the binding energies are smaller than in complexes with free Me(2)CO molecules, reflecting the geometrical constraints in the polydentate ligands. The binding energy of NH4+ in various polydentate complexes is similar to that of K+ and smaller than that of H3O+ by 105 +/- 12 kJ/mol (25 +/- 3 kcal/mol). Based on the H3O+ to crown ether binding energies, these relations can be used to estimate the binding energy of NH4+ and K+ to 15-crown-5 of 248 +/- 12 kl/mol (59 +/- 3 kcal/mol) and to 18-crown-6 of 296 +/- 12 kJ/mol (71 +/- 3 kcal/mol). The order of binding energies of oxygen-containing ligands to H3O+ > Na+ > NH4+ approximate to K+ is reproduced by ab initio calculations on complexes with MeOCH(2)CH(2)OMe. The amount of calculated charge transfer to the ligands follows the order of binding energies. The difference between the binding energies of H3O+ and NH4+ to oxygen-containing ligands in the gas-phase complexes is similar to the condensed-phase aqueous heats of solvation of these ions. C1 UNIV MARYLAND BALTIMORE CTY,DEPT CHEM & BIOCHEM,BALTIMORE,MD 21228. SO ILLINOIS UNIV,DEPT CHEM & BIOCHEM,CARBONDALE,IL 62901. RP Mautner, MMN (reprint author), NATL INST STAND & TECHNOL,DIV CHEM KINET & THERMODYNAM,GAITHERSBURG,MD 20899, USA. NR 34 TC 1 Z9 1 U1 0 U2 2 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 SN 0022-3654 J9 J PHYS CHEM-US JI J. Phys. Chem. PD APR 18 PY 1996 VL 100 IS 16 BP 6445 EP 6450 PG 6 WC Chemistry, Physical SC Chemistry GA UF879 UT WOS:A1996UF87900016 ER PT J AU Huey, LG Dunlea, EJ Howard, CJ AF Huey, LG Dunlea, EJ Howard, CJ TI Gas-phase acidity of CF3OH SO JOURNAL OF PHYSICAL CHEMISTRY LA English DT Article ID BISTRIFLUOROMETHYL PEROXIDE; FLUORIDE; DECOMPOSITION; CHEMISTRY; RADICALS; KINETICS; IONS AB Ion-molecule reactions of CF3O-, CF3O, and CF3OH were studied using the flowing afterglow technique to evaluate the thermochemistry of CF3OH and related compounds. The gas-phase acidity of CF3OH was measured to be Delta(r)H(acid)(o) = 329.8 +/- 2.0 kcal mol(-1) by ion-molecule reaction bracketing. A limit on the electron affinity of the CF3O radical of greater than or equal to 89.2 kcal mol(-1) was also determined. The CF3O-H bond strength derived from these results is 124.7 +/- 3.6 kcal mol(-1), which is consistent with recent ab initio calculations of the heats of formation of CF3O and CF3OH. C1 NOAA,AERON LAB,BOULDER,CO 80303. NR 43 TC 24 Z9 24 U1 0 U2 4 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 SN 0022-3654 J9 J PHYS CHEM-US JI J. Phys. Chem. PD APR 18 PY 1996 VL 100 IS 16 BP 6504 EP 6508 DI 10.1021/jp953058m PG 5 WC Chemistry, Physical SC Chemistry GA UF879 UT WOS:A1996UF87900025 ER PT J AU Xiao, GY Liu, SX Ji, XH Johnson, WW Chen, JH Parsons, JF Stevens, WJ Gilliland, GL Armstrong, RN AF Xiao, GY Liu, SX Ji, XH Johnson, WW Chen, JH Parsons, JF Stevens, WJ Gilliland, GL Armstrong, RN TI First-sphere and second-sphere electrostatic effects in the active site of a class Mu glutathione transferase SO BIOCHEMISTRY LA English DT Article ID S-TRANSFERASE; 3-DIMENSIONAL STRUCTURE; CATALYTIC MECHANISM; MACROMOLECULAR STRUCTURES; AROMATIC INTERACTIONS; BINDING PROTEIN; HYDROGEN-BOND; REFINEMENT; RESOLUTION; COMPLEX AB The activation of the thiol of glutathione (GSH) bound in the active site of the class mu glutathione transferase M1-1 from rat involves a hydrogen-bonding network that includes a direct (first-sphere) interaction between the hydroxyl group of Y6 and the sulfur of GSH and second-sphere interactions involving a hydrogen bond between the main-chain amide N-H of L12 and the hydroxyl group of Y6 and an on-face hydrogen bond between the hydroxyl group of T13 and the pi-electron cloud of Y6 (i.e., T13-OH---pi-Y6-OH---SG). The functions of these hydrogen bonds have been examined with a combination of site-specific mutagenesis and X-ray crystallography. The hydroxyl group of Y6 has a normal pK(a) of about 10 even though it is shielded from solvent and is in a largely hydrophobic environment. The apparent pK(a) of GSH in the binary Y6F . GSH complex is increased by 1.6 log units, land the reactivity of the enzyme-bound nucleophile is reduced, The catalytic properties of the Y6L mutant are identical to those of Y6F, suggesting that the weakly polar on-edge interaction between the aromatic ring and sulfur has no influence on catalysis. The refined three-dimensional structure of the Y6F mutant in complex with GSH shows no major structural perturbation of the protein other than a change in the coordination environment of the sulfur. Removal of the second-sphere influence of the on-face hydrogen bond between the hydroxyl group of T13 as in the T13V and T13A mutants elevates the pK(a) of enzyme-bound GSH by about 0.7 pK(a) units. Crystal structures of these mutants show that structural changes in the active site are minor and suggest that the changes in pK(a) of E . GSH are due to the presence or absence of the on-face hydrogen bond. The T13S mutant has a completely different side-chain hydrogen-bonding geometry than T13 in the native enzyme and catalytic properties similar to the T13A and T13V mutants consistent with the absence of an on-face hydrogen bond. The gamma-methyl group of T13 is essential in enforcing the on-face hydrogen bond geometry and preventing the hydroxyl group from forming more favorable conventional hydrogen bonds. C1 UNIV MARYLAND,DEPT CHEM & BIOCHEM,COLLEGE PK,MD 20742. UNIV MARYLAND,MARYLAND BIOTECHNOL INST,CTR ADV RES BIOTECHNOL,SHADY GROVE,MD. NIST,CTR ADV RES BIOTECHNOL,ROCKVILLE,MD 20850. VANDERBILT UNIV,SCH MED,DEPT BIOCHEM,NASHVILLE,TN 37232. VANDERBILT UNIV,SCH MED,CTR MOLEC TOXICOL,NASHVILLE,TN 37232. RI Ji, Xinhua/C-9664-2012 OI Ji, Xinhua/0000-0001-6942-1514 FU NIGMS NIH HHS [GM30910] NR 55 TC 61 Z9 63 U1 1 U2 6 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 SN 0006-2960 J9 BIOCHEMISTRY-US JI Biochemistry PD APR 16 PY 1996 VL 35 IS 15 BP 4753 EP 4765 DI 10.1021/bi960189k PG 13 WC Biochemistry & Molecular Biology SC Biochemistry & Molecular Biology GA UF521 UT WOS:A1996UF52100013 PM 8664265 ER PT J AU Bruno, TJ Wertz, KH Caciari, M AF Bruno, TJ Wertz, KH Caciari, M TI Kovats retention indices of halocarbons on a hexafluoropropylene epoxide-modified graphitized carbon black SO ANALYTICAL CHEMISTRY LA English DT Article ID GAS-LIQUID-CHROMATOGRAPHY; INDEX SYSTEM AB Kovats retention indices of 97 halocarbons related to research on alternative refrigerants, propellants, foaming agents, and blowing agents have been measured on a packed column stationary phase consisting of a 5% (mass/mass) coating of a low molecular weight polymer of hexafluoropropylene epoxide on graphitized carbon black. The measurements on each fluid have been made at four temperatures, and the thermal dependence of the indices has been modeled with appropriate equations. The modeled values are suitable for the identification of these compounds by gas chromatography on both laboratory and field instrumentation, The values are also useful for the optimization of more sophisticated analyses needed in specific situations. The results indicate that the stationary phase chosen will provide separation of nearly all the fluids of interest. Moreover, we show that there is sufficient spread in the retention index values to facilitate fluid identification. The measurements also appear to fit a qualitative triangular property diagram that has been useful for classifying alternative refrigerant fluids and related compounds. C1 FT LUPTON HIGH SCH,FT LUPTON,CO 80621. RP Bruno, TJ (reprint author), NATL INST STAND & TECHNOL,CHEM SCI & TECHNOL LAB,DIV THERMOPHYS,BOULDER,CO 80303, USA. NR 36 TC 11 Z9 12 U1 1 U2 2 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 SN 0003-2700 J9 ANAL CHEM JI Anal. Chem. PD APR 15 PY 1996 VL 68 IS 8 BP 1347 EP 1359 DI 10.1021/ac9510191 PG 13 WC Chemistry, Analytical SC Chemistry GA UE566 UT WOS:A1996UE56600011 ER PT J AU Dziak, RP Fox, CG Embley, RW Lupton, JE Johnson, GC Chadwick, WW Koski, RA AF Dziak, RP Fox, CG Embley, RW Lupton, JE Johnson, GC Chadwick, WW Koski, RA TI Detection of and response to a probable volcanogenic T-wave event swarm on the western Blanco Transform Fault Zone SO GEOPHYSICAL RESEARCH LETTERS LA English DT Article ID PACIFIC AB The East Blanco Depression (EBD), a pull-apart basin within the western Blanco Transform Fault Zone (BTFZ), was the site of an intense earthquake T-wave swarm that began at 1317Z on January 9, 1994. Although tectonically generated earthquakes occur frequently along the BTFZ, this swarm was unusual in that it was preceded and accompanied by periodic, low-frequency, long-duration acoustic signals, that originated from near the swarm epicenters. These tremor-like signals were very similar in character to acoustic energy produced by a shallow-submarine eruption near Socorro Island, a seamount several hundred km west of Baja, California. The similar to 69 earthquakes and similar to 400 tremor-like events at the EBD occurred sporadically, with two periods of peak activity occurring between January 5-16 and 27-31. The swarm-like character of the earthquakes and the similarity of the tremor activity to the Socorro eruption indicated that the EBD was undergoing an intrusion or eruption episode. On January 27, six CTD/rosette casts were conducted at the site. Water samples from two of the stations yielded anomalous He-3 concentrations, with maxima at similar to 2800 m depth over the main basin. In June 1994 two camera tows within the basin yielded evidence of pillow-lava volcanism and hydrothermal deposits, but no conclusive evidence of a recent seafloor eruption. In September 1994, deployments of the U.S. Navy's Advanced Tethered Vehicle resulted in the discovery of an active hydrothermal mound on the flanks of a pillow-lava volcano. The hydrothermal mound consists of Fe-rich hydrothermal precipitate and bacterial mats. Temperatures to 60 degrees C were measured 30 cm below the surface. This is the first discovery of active hydrothermal vents along an oceanic fracture zone. Although no conclusive evidence of volcanic activity associated with the T-wave event swarm was found during these response efforts, the EBD has been the site of recent seafloor eruptions. C1 NOAA,PACIFIC MARINE ENVIRONM LAB,SEATTLE,WA 98115. US GEOL SURVEY,MENLO PK,CA 94025. HATFIELD MARINE SCI CTR,PACIFIC MARINE ENVIRONM LAB,NOAA,NEWPORT,OR 97365. RP Dziak, RP (reprint author), OREGON STATE UNIV,HATFIELD MARINE SCI CTR,COOPERAT INST MARINE RESOURCES STUDIES,DEPT GEOSCI,NEWPORT,OR 97365, USA. RI Johnson, Gregory/I-6559-2012 OI Johnson, Gregory/0000-0002-8023-4020 NR 16 TC 18 Z9 18 U1 0 U2 1 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 SN 0094-8276 J9 GEOPHYS RES LETT JI Geophys. Res. Lett. PD APR 15 PY 1996 VL 23 IS 8 BP 873 EP 876 DI 10.1029/96GL00240 PG 4 WC Geosciences, Multidisciplinary SC Geology GA UF439 UT WOS:A1996UF43900021 ER PT J AU Bennett, LH Wang, PS Donahue, MJ AF Bennett, LH Wang, PS Donahue, MJ TI Artifacts in magnetic resonance imaging from metals SO JOURNAL OF APPLIED PHYSICS LA English DT Article; Proceedings Paper CT 40th Annual Conference on Magnetism and Magnetic Materials CY NOV 06-09, 1995 CL PHILADELPHIA, PA SP Amer Inst Phys, IEEE, Magnet Soc, Minerals Met & Mat Soc, Amer Soc Testing & Mat, USN, Off Naval Res, Amer Ceram Soc AB Metallic biomedical implants, such as aneurysm Clips, endoprostheses, and internal orthopedic devices give rise to artifacts in the magnetic resonance image (MRI) of patients. Such artifacts impair the information contained in the image in precisely the region of most interest, namely near the metallic device. Ferromagnetic materials are contraindicated because of the hazards associated with their movement during the MRI procedure. In less-magnetic metals, it has been suggested that the extent of the artifact is related to the magnetic susceptibility of the metal, but no systematic data appear to be available. When the susceptibility is sufficiently small, an additional artifact due to electrical conductivity is observed. We present an initial systematic study of MRI artifacts produced by two low susceptibility metals, titanium (relative permeability mu(r) approximate to 1.0002) and copper (mu(r) approximate to 0.99998), including experimental, theoretical, and computer simulation results. (C) 1996 American Institute of Physics. RP Bennett, LH (reprint author), NATL INST STAND & TECHNOL,GAITHERSBURG,MD 20899, USA. NR 10 TC 34 Z9 34 U1 2 U2 13 PU AMER INST PHYSICS PI WOODBURY PA CIRCULATION FULFILLMENT DIV, 500 SUNNYSIDE BLVD, WOODBURY, NY 11797-2999 SN 0021-8979 J9 J APPL PHYS JI J. Appl. Phys. PD APR 15 PY 1996 VL 79 IS 8 BP 4712 EP 4714 DI 10.1063/1.361649 PN 2A PG 3 WC Physics, Applied SC Physics GA UG877 UT WOS:A1996UG87700087 ER PT J AU Borchers, JA Gehring, PM Erwin, RW Majkrzak, CF Ankner, JF Hylton, TL Coffey, KR Parker, MA Howard, JK AF Borchers, JA Gehring, PM Erwin, RW Majkrzak, CF Ankner, JF Hylton, TL Coffey, KR Parker, MA Howard, JK TI Nature of the interlayer coupling in annealed Ni80Fe20/Ag multilayers SO JOURNAL OF APPLIED PHYSICS LA English DT Article; Proceedings Paper CT 40th Annual Conference on Magnetism and Magnetic Materials CY NOV 06-09, 1995 CL PHILADELPHIA, PA SP Amer Inst Phys, IEEE, Magnet Soc, Minerals Met & Mat Soc, Amer Soc Testing & Mat, USN, Off Naval Res, Amer Ceram Soc ID GIANT MAGNETORESISTANCE; SUPERLATTICES AB Using x-ray and polarized neutron (PNR) reflectivity, we have measured the structural and magnetic depth profiles of annealed Ni80Fe20 (20 Angstrom)/Ag (40 Angstrom) multilayers. The x-ray data indicate that the interfaces are highly mixed. PNR measurements of the 335 degrees C annealed multilayer in small magnetic fields reveal a broad feature in the off-specular spin-flip scattering that is not present for the unannealed sample. The giant magnetoresistance is thus associated with antiferromagnetic correlations between micrometer-sized magnetic domains within the Ni80Fe20 layers. This spin ordering is consistent with a model in which weak dipolar forces lead to an antiparallel alignment of the domains across the Ag layers. (C) 1996 American Institute of Physics. C1 UNIV MISSOURI,RES REACTOR FACIL,COLUMBIA,MO 65211. IBM CORP,STORAGE SYST DIV,SAN JOSE,CA 95193. RP Borchers, JA (reprint author), NIST,DIV REACTOR RADIAT,GAITHERSBURG,MD 20899, USA. OI Ankner, John/0000-0002-6737-5718; Gehring, Peter/0000-0002-9236-2046 NR 12 TC 8 Z9 8 U1 1 U2 3 PU AMER INST PHYSICS PI WOODBURY PA CIRCULATION FULFILLMENT DIV, 500 SUNNYSIDE BLVD, WOODBURY, NY 11797-2999 SN 0021-8979 J9 J APPL PHYS JI J. Appl. Phys. PD APR 15 PY 1996 VL 79 IS 8 BP 4762 EP 4764 DI 10.1063/1.361664 PN 2A PG 3 WC Physics, Applied SC Physics GA UG877 UT WOS:A1996UG87700102 ER PT J AU Michel, RP Chaiken, A Wall, MA Dykes, JW Ankner, JF Kaiser, H AF Michel, RP Chaiken, A Wall, MA Dykes, JW Ankner, JF Kaiser, H TI Anomalous temperature dependence of interlayer coupling in Fe/Si multilayers SO JOURNAL OF APPLIED PHYSICS LA English DT Meeting Abstract C1 NATL INST STAND & TECHNOL,BOULDER,CO 80303. UNIV MISSOURI,COLUMBIA,MO 65211. LAWRENCE LIVERMORE NATL LAB,LIVERMORE,CA 94550. NR 3 TC 2 Z9 2 U1 0 U2 1 PU AMER INST PHYSICS PI WOODBURY PA CIRCULATION FULFILLMENT DIV, 500 SUNNYSIDE BLVD, WOODBURY, NY 11797-2999 SN 0021-8979 J9 J APPL PHYS JI J. Appl. Phys. PD APR 15 PY 1996 VL 79 IS 8 BP 4775 EP 4775 DI 10.1063/1.361861 PN 2A PG 1 WC Physics, Applied SC Physics GA UG877 UT WOS:A1996UG87700107 ER PT J AU Ankner, JF Kaiser, H Hamacher, K Schreyer, A Zeidler, T Zabel, H Majkrzak, CF Schafer, M Grunberg, P AF Ankner, JF Kaiser, H Hamacher, K Schreyer, A Zeidler, T Zabel, H Majkrzak, CF Schafer, M Grunberg, P TI Structural, field, and temperature dependence of noncollinear magnetic coupling in Fe/Cr(001) superlattices SO JOURNAL OF APPLIED PHYSICS LA English DT Meeting Abstract C1 RUHR UNIV BOCHUM, D-44780 BOCHUM, GERMANY. NIST, GAITHERSBURG, MD 20899 USA. FORSCHUNGSZENTRUM JULICH, FORSCHUNGSZENTRUM, D-52425 JULICH, GERMANY. UNIV MISSOURI, RES REACTOR, COLUMBIA, MO 65211 USA. RI Zabel, Hartmut/C-1994-2009 NR 0 TC 2 Z9 2 U1 0 U2 0 PU AMER INST PHYSICS PI MELVILLE PA 1305 WALT WHITMAN RD, STE 300, MELVILLE, NY 11747-4501 USA SN 0021-8979 EI 1089-7550 J9 J APPL PHYS JI J. Appl. Phys. PD APR 15 PY 1996 VL 79 IS 8 BP 4782 EP 4782 DI 10.1063/1.361670 PN 2A PG 1 WC Physics, Applied SC Physics GA UG877 UT WOS:A1996UG87700110 ER PT J AU Moschel, A Zangwill, A Stiles, MD AF Moschel, A Zangwill, A Stiles, MD TI Simulations of inhomogeneous magnetization processes in ultrathin films with growth-induced roughness SO JOURNAL OF APPLIED PHYSICS LA English DT Meeting Abstract C1 NATL INST STAND & TECHNOL,ELECTRON PHYS GRP,GAITHERSBURG,MD 20899. GEORGIA INST TECHNOL,SCH PHYS,ATLANTA,GA 30332. RI Stiles, Mark/K-2426-2012 OI Stiles, Mark/0000-0001-8238-4156 NR 0 TC 0 Z9 0 U1 0 U2 0 PU AMER INST PHYSICS PI WOODBURY PA CIRCULATION FULFILLMENT DIV, 500 SUNNYSIDE BLVD, WOODBURY, NY 11797-2999 SN 0021-8979 J9 J APPL PHYS JI J. Appl. Phys. PD APR 15 PY 1996 VL 79 IS 8 BP 4994 EP 4994 DI 10.1063/1.361550 PN 2A PG 1 WC Physics, Applied SC Physics GA UG877 UT WOS:A1996UG87700192 ER PT J AU Broholm, C Aeppli, G Lee, SH Bao, W DiTusa, JF AF Broholm, C Aeppli, G Lee, SH Bao, W DiTusa, JF TI Strong magnetic fluctuations in transition metal oxides SO JOURNAL OF APPLIED PHYSICS LA English DT Article; Proceedings Paper CT 40th Annual Conference on Magnetism and Magnetic Materials CY NOV 06-09, 1995 CL PHILADELPHIA, PA SP Amer Inst Phys, IEEE, Magnet Soc, Minerals Met & Mat Soc, Amer Soc Testing & Mat, USN, Off Naval Res, Amer Ceram Soc ID KAGOME LATTICE; FRUSTRATION; EXCITATIONS; INSULATOR; SYSTEM; CHAINS; PHASE; ORDER; V2O3; NENP AB Most magnets have long-range magnetic order when the thermal energy is less than the local magnetic exchange energy (T<\Theta(CW)). Effects such as reduced dimensionality and frustration, however, can suppress the ordering transition and lead to unusual cooperative paramagnetic phases at low temperatures. We review neutron scattering experiments exploring such short-range-ordered phases in insulating transition metal oxides. We discuss (V1-xCrx)(2)O-3, in which orbital fluctuations appear to limit spin correlations to within small ''molecular'' clusters, SrCr9pGa12-9pO19, in which geometrical frustration allows local antiferromagnetic constraints to be fulfilled without long,ranged order, and Y2BaNiO5, in which magnetic interactions occur only within chains of spins which,are unable to order because of the Haldane effect. Emphasis is placed on the common features of exchange interactions in these oxides and the important role which magnetic neutron scattering has played in understanding the unusual magnetic phenomena. (C) 1996 American Institute of Physics. C1 NATL INST STAND & TECHNOL,GAITHERSBURG,MD 20899. AT&T BELL LABS,MURRAY HILL,NJ 07974. LOUISIANA STATE UNIV,DEPT PHYS & ASTRON,BATON ROUGE,LA 70803. RP Broholm, C (reprint author), JOHNS HOPKINS UNIV,DEPT PHYS & ASTRON,BALTIMORE,MD 21218, 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 40 TC 9 Z9 9 U1 1 U2 8 PU AMER INST PHYSICS PI WOODBURY PA CIRCULATION FULFILLMENT DIV, 500 SUNNYSIDE BLVD, WOODBURY, NY 11797-2999 SN 0021-8979 J9 J APPL PHYS JI J. Appl. Phys. PD APR 15 PY 1996 VL 79 IS 8 BP 5023 EP 5028 DI 10.1063/1.361564 PN 2A PG 6 WC Physics, Applied SC Physics GA UG877 UT WOS:A1996UG87700207 ER PT J AU Erwin, RW Borchers, JA Lind, DM Lochner, E Shaw, KA Singer, B Stoyonov, P DiBari, RC Berry, SD AF Erwin, RW Borchers, JA Lind, DM Lochner, E Shaw, KA Singer, B Stoyonov, P DiBari, RC Berry, SD TI Domain structure in NiO biasing layers SO JOURNAL OF APPLIED PHYSICS LA English DT Meeting Abstract C1 NIST,MAT SCI & ENGN LAB,GAITHERSBURG,MD 20899. FLORIDA STATE UNIV,TALLAHASSEE,FL 32306. LIMESTONE COLL,GAFFNEY,SC. NR 1 TC 0 Z9 0 U1 0 U2 2 PU AMER INST PHYSICS PI WOODBURY PA CIRCULATION FULFILLMENT DIV, 500 SUNNYSIDE BLVD, WOODBURY, NY 11797-2999 SN 0021-8979 J9 J APPL PHYS JI J. Appl. Phys. PD APR 15 PY 1996 VL 79 IS 8 BP 5102 EP 5102 DI 10.1063/1.361314 PN 2A PG 1 WC Physics, Applied SC Physics GA UG877 UT WOS:A1996UG87700235 ER PT J AU Egelhoff, WF Chen, PJ Powell, CJ Stiles, MD McMichael, RD Lin, CL Sivertsen, JM Judy, JH Takano, K Berkowitz, AE Anthony, TC Brug, JA AF Egelhoff, WF Chen, PJ Powell, CJ Stiles, MD McMichael, RD Lin, CL Sivertsen, JM Judy, JH Takano, K Berkowitz, AE Anthony, TC Brug, JA TI Optimizing the giant magnetoresistance of symmetric and bottom spin valves SO JOURNAL OF APPLIED PHYSICS LA English DT Article; Proceedings Paper CT 40th Annual Conference on Magnetism and Magnetic Materials CY NOV 06-09, 1995 CL PHILADELPHIA, PA SP Amer Inst Phys, IEEE, Magnet Soc, Minerals Met & Mat Soc, Amer Soc Testing & Mat, USN, Off Naval Res, Amer Ceram Soc ID ELECTRICAL-RESISTIVITY; EXCHANGE-ANISOTROPY; GOLD-FILMS; NIO; MULTILAYERS; NI81FE19; COO AB We have attempted to optimize the values of the giant magnetoresistance in symmetric spin valves of the type NiO/Co/Cu/Co/Cu/Co/NiO (achieving 23.4%) and in bottom spin valves of the type Co/Cu/Co/NiO (achieving 17.0%), the largest values ever reported for such structures. The key elements in this achievement are improved vacuum conditions and careful attention to the film thicknesses. (C) 1996 American Institute of Physics. C1 UNIV CALIF SAN DIEGO,DEPT PHYS,LA JOLLA,CA 92093. HEWLETT PACKARD LABS,PALO ALTO,CA 94304. UNIV MINNESOTA,CTR MICROMAGNET & INFORMAT TECHNOL,DEPT CHEM ENGN & MAT SCI,MINNEAPOLIS,MN 55455. UNIV MINNESOTA,CTR MICROMAGNET & INFORMAT TECHNOL,DEPT ELECT ENGN,MINNEAPOLIS,MN 55455. RP Egelhoff, WF (reprint author), NIST,GAITHERSBURG,MD 20899, USA. RI McMichael, Robert/J-8688-2012; Stiles, Mark/K-2426-2012 OI Stiles, Mark/0000-0001-8238-4156 NR 28 TC 56 Z9 58 U1 0 U2 3 PU AMER INST PHYSICS PI WOODBURY PA CIRCULATION FULFILLMENT DIV, 500 SUNNYSIDE BLVD, WOODBURY, NY 11797-2999 SN 0021-8979 J9 J APPL PHYS JI J. Appl. Phys. PD APR 15 PY 1996 VL 79 IS 8 BP 5277 EP 5281 DI 10.1063/1.361352 PN 2A PG 5 WC Physics, Applied SC Physics GA UG877 UT WOS:A1996UG87700302 ER PT J AU Gavrin, A Kelley, MH Xiao, JQ Chien, CL AF Gavrin, A Kelley, MH Xiao, JQ Chien, CL TI Magnetic domain percolation in granular Co-Ag SO JOURNAL OF APPLIED PHYSICS LA English DT Article; Proceedings Paper CT 40th Annual Conference on Magnetism and Magnetic Materials CY NOV 06-09, 1995 CL PHILADELPHIA, PA SP Amer Inst Phys, IEEE, Magnet Soc, Minerals Met & Mat Soc, Amer Soc Testing & Mat, USN, Off Naval Res, Amer Ceram Soc ID GIANT MAGNETORESISTANCE; FILMS AB The most dramatic changes in the properties of granular metals occur near the percolation threshold x(c), which generally occurs at a volume fraction of approximately 0.50. There has been much speculation concerning the evolution of magnetic domains at x(c), however, no direct observations have been produced. Using scanning electron microscopy with polarization analysis, we investigate the formation of domains in a series of granular Co-Ag samples. We find x(c) to lie in the range [0.50, 0.55], and we report on the size and morphology of the observed domains. Below x(c), a domain pattern appears which may be due either to interparticle correlations or to residual Co in the silver matrix; we have previously discussed the ramifications of this observation on an understanding of GMR. In this paper, we place limits on the latter of these two models. Above x(c), the domains resemble ''stripe domains'' which have been observed in amorphous materials. This observation suggests the presence of anisotropy perpendicular to the film plane. (C) 1996 American Institute of Physics. C1 NIST,GAITHERSBURG,MD 20899. JOHNS HOPKINS UNIV,DEPT PHYS & ASTRON,BALTIMORE,MD 21218. NR 13 TC 11 Z9 11 U1 0 U2 1 PU AMER INST PHYSICS PI WOODBURY PA CIRCULATION FULFILLMENT DIV, 500 SUNNYSIDE BLVD, WOODBURY, NY 11797-2999 SN 0021-8979 J9 J APPL PHYS JI J. Appl. Phys. PD APR 15 PY 1996 VL 79 IS 8 BP 5306 EP 5308 DI 10.1063/1.361360 PN 2A PG 3 WC Physics, Applied SC Physics GA UG877 UT WOS:A1996UG87700311 ER PT J AU Donahue, MJ Bennett, LH McMichael, RD Swartzendruber, LJ Shapiro, AJ Nikitenko, VI Gornakov, VS Dedukh, LM Khapikov, AF Matveev, VN Levashov, VI AF Donahue, MJ Bennett, LH McMichael, RD Swartzendruber, LJ Shapiro, AJ Nikitenko, VI Gornakov, VS Dedukh, LM Khapikov, AF Matveev, VN Levashov, VI TI Complementary imaging of granular Co-Ag films with magneto-optical indicator film technique and magnetic force microscopy SO JOURNAL OF APPLIED PHYSICS LA English DT Article; Proceedings Paper CT 40th Annual Conference on Magnetism and Magnetic Materials CY NOV 06-09, 1995 CL PHILADELPHIA, PA SP Amer Inst Phys, IEEE, Magnet Soc, Minerals Met & Mat Soc, Amer Soc Testing & Mat, USN, Off Naval Res, Amer Ceram Soc AB A magneto-optical indicator him (MOIF) technique and magnetic force microscopy were used for visualization and direct real-time experimental study of the magnetization processes of magnetic Co90Ag10 granular films. It is shown that the magnetization reversal of the as-deposited films follows a specific two-step course. The first stage is characterized by gradual spin rotation to large angles up to 90 degrees without domain formation. Further magnetization reversal proceeds by the nucleation and motion of zigzag-shaped domain walls. The dendritic structure of the domain walls was observed using both techniques. Also tracks of magnetic inhomogeneities remaining behind moving zigzag-shaped domain walls was revealed by MOIF. (C) 1996 American Institute of Physics. C1 RUSSIAN ACAD SCI,INST SOLID STATE PHYS,CHERNOGOLOVKA 142432,RUSSIA. RUSSIAN ACAD SCI,INST MICROELECTR TECHNOL & HIGH PURITY MAT,CHERNOGOLOVKA 142432,RUSSIA. RP Donahue, MJ (reprint author), NIST,GAITHERSBURG,MD 20899, USA. RI McMichael, Robert/J-8688-2012; OI McMichael, Robert/0000-0002-1372-664X NR 12 TC 9 Z9 9 U1 0 U2 2 PU AMER INST PHYSICS PI WOODBURY PA CIRCULATION FULFILLMENT DIV, 500 SUNNYSIDE BLVD, WOODBURY, NY 11797-2999 SN 0021-8979 J9 J APPL PHYS JI J. Appl. Phys. PD APR 15 PY 1996 VL 79 IS 8 BP 5315 EP 5317 DI 10.1063/1.361363 PN 2A PG 3 WC Physics, Applied SC Physics GA UG877 UT WOS:A1996UG87700314 ER PT J AU Kemner, KM Harris, VG Chakarian, V Idzerda, YU Elam, WT Kao, CC Feng, YC Laughlin, DE Woicik, JC AF Kemner, KM Harris, VG Chakarian, V Idzerda, YU Elam, WT Kao, CC Feng, YC Laughlin, DE Woicik, JC TI The role of Ta and Pt in segregation within Co-Cr-Ta and Co-Cr-Pt thin film magnetic recording media SO JOURNAL OF APPLIED PHYSICS LA English DT Article; Proceedings Paper CT 40th Annual Conference on Magnetism and Magnetic Materials CY NOV 06-09, 1995 CL PHILADELPHIA, PA SP Amer Inst Phys, IEEE, Magnet Soc, Minerals Met & Mat Soc, Amer Soc Testing & Mat, USN, Off Naval Res, Amer Ceram Soc ID RAY CIRCULAR-DICHROISM AB Polarization dependent extended x-ray absorption fine structure (PD-EXAFS) and magnetic circular dichroism (MCD) measurements of CoCrTa and CoCrPt films, sputter deposited at varying substrate temperatures, were performed to investigate the average local structure and chemistry about the Ta, Pt, and Co atoms and the average magnetic moment of the Co and Cr atoms within these films. Results from the MCD measurements indicate the average net magnetic moment of the Cr atoms is opposite in direction and five percent in amplitude relative to the Co moments. Inspection of the Fourier transforms of the XAFS data from these samples shows an increase in structural disorder around the Ta and Pt atoms with increasing substrate deposition temperature. A further comparison between the Ta and Pt edge EXAFS results show that the temperature-dependent increase in structural disorder is greater around the Ta atoms in the CoCrTa system than it is around the Pt atoms in the CoCrPt system. (C) 1996 American Institute of Physics. C1 BROOKHAVEN NATL LAB,UPTON,NY 11973. CARNEGIE MELLON UNIV,DEPT MAT SCI & ENGN,PITTSBURGH,PA 15213. NATL INST STAND & TECHNOL,GAITHERSBURG,MD 20899. RP Kemner, KM (reprint author), USN,RES LAB,WASHINGTON,DC 20375, USA. RI Harris, Vincent/A-8337-2009 NR 12 TC 7 Z9 8 U1 0 U2 0 PU AMER INST PHYSICS PI WOODBURY PA CIRCULATION FULFILLMENT DIV, 500 SUNNYSIDE BLVD, WOODBURY, NY 11797-2999 SN 0021-8979 J9 J APPL PHYS JI J. Appl. Phys. PD APR 15 PY 1996 VL 79 IS 8 BP 5345 EP 5347 DI 10.1063/1.361372 PN 2A PG 3 WC Physics, Applied SC Physics GA UG877 UT WOS:A1996UG87700324 ER PT J AU Roshko, A Dulcie, LL Nguyen, T Yogi, T AF Roshko, A Dulcie, LL Nguyen, T Yogi, T TI Influence of sputter gas and sputter pressure on the structure and magnetic properties of Co-Pt-Cr thin films SO JOURNAL OF APPLIED PHYSICS LA English DT Meeting Abstract C1 NATL INST STAND & TECHNOL,DIV ELECTROMAGNET TECHNOL,BOULDER,CO 80303. IBM CORP,DIV RES,SAN JOSE,CA 95120. NR 0 TC 0 Z9 0 U1 3 U2 4 PU AMER INST PHYSICS PI WOODBURY PA CIRCULATION FULFILLMENT DIV, 500 SUNNYSIDE BLVD, WOODBURY, NY 11797-2999 SN 0021-8979 J9 J APPL PHYS JI J. Appl. Phys. PD APR 15 PY 1996 VL 79 IS 8 BP 5358 EP 5358 DI 10.1063/1.361325 PN 2A PG 1 WC Physics, Applied SC Physics GA UG877 UT WOS:A1996UG87700329 ER PT J AU Atzmony, U Livne, Z McMichael, RD Bennett, LH AF Atzmony, U Livne, Z McMichael, RD Bennett, LH TI Magnetic viscosity investigations of nanograin iron powder SO JOURNAL OF APPLIED PHYSICS LA English DT Article; Proceedings Paper CT 40th Annual Conference on Magnetism and Magnetic Materials CY NOV 06-09, 1995 CL PHILADELPHIA, PA SP Amer Inst Phys, IEEE, Magnet Soc, Minerals Met & Mat Soc, Amer Soc Testing & Mat, USN, Off Naval Res, Amer Ceram Soc AB Magnetic properties of three kinds of nanogram Fe powder were studied. The first two, designated as NM(Ar) and NM(N), were obtained by ball milling the iron powder under an argon or nitrogen atmosphere. The third, designated NN, was obtained by evaporation and condensation. They have grain sizes of 20, 7, and 60 nm, respectively. The particle sizes of the first two were in the micrometer range, whereas those of the NN were in the nanometer range. The NN powder exhibited a coercivity of 79 mT; its magnetic moment at saturation was lower than that of bulk iron. The coercivities of the NM(N) and NM(Ar) were smaller and their magnetic moment values at high fields were closer to that of bulk iron (210 A . m(2)/kg). The NM(N) and NN samples exhibited marked time dependences of the magnetic moments following a relatively abrupt change of the applied field. The moment changes by more than 0.5% of the saturation moment within 50 min and continues to change for many hours. Much smaller effects were detected in the NM(Ar) sample. The viscosities were investigated as a function of temperature and jump field. The results showed differences in the behavior of the three samples. The powders were consolidated by cold isostatic pressing followed by sintering at around 600 degrees C for several hours. The magnetic behavior of the sintered samples approach that of bulk iron. (C) 1996 American Institute of Physics. C1 NUCL RES CTR NEGEV,IL-84190 BEER SHEVA,ISRAEL. RP Atzmony, U (reprint author), NATL INST STAND & TECHNOL,GAITHERSBURG,MD 20899, USA. RI McMichael, Robert/J-8688-2012; OI McMichael, Robert/0000-0002-1372-664X NR 7 TC 6 Z9 7 U1 0 U2 3 PU AMER INST PHYSICS PI WOODBURY PA CIRCULATION FULFILLMENT DIV, 500 SUNNYSIDE BLVD, WOODBURY, NY 11797-2999 SN 0021-8979 J9 J APPL PHYS JI J. Appl. Phys. PD APR 15 PY 1996 VL 79 IS 8 BP 5456 EP 5458 DI 10.1063/1.362336 PN 2A PG 3 WC Physics, Applied SC Physics GA UG877 UT WOS:A1996UG87700370 ER PT J AU Dykes, JW Kim, YK Tsoukatos, A Gupta, S Sanders, SC AF Dykes, JW Kim, YK Tsoukatos, A Gupta, S Sanders, SC TI Giant magnetoresistance and high sensitivity in annealed NiFeCo/Ag multilayers SO JOURNAL OF APPLIED PHYSICS LA English DT Article; Proceedings Paper CT 40th Annual Conference on Magnetism and Magnetic Materials CY NOV 06-09, 1995 CL PHILADELPHIA, PA SP Amer Inst Phys, IEEE, Magnet Soc, Minerals Met & Mat Soc, Amer Soc Testing & Mat, USN, Off Naval Res, Amer Ceram Soc ID SUBSTRATE AB We report giant magnetoresistance in annealed NiFeCo (2 nm)/Ag (3.3 nm) multilayers. For all samples, post-deposition annealing was necessary for the observation of GMR analogous to the NiFe/Ag discontinuous multilayer system. The GMR ratio and field sensitivity varied widely as a function of annealing from temperatures between 300 and 400 degrees C. A high MR ratio of 6.3% and field sensitivity of 11.3%(kA/m) (0.9%/Oe) were observed for a seven bilayer sample annealed to 350 degrees C. In general, NiFeCo/Ag multilayers produced greater MR responses and field sensitivities than comparably annealed NiFe/Ag multilayers. NiFeCo/Ag multilayers, however, display more hysteresis than NiFe/Ag multilayers and lack a zero-crossing saturation magnetostriction versus annealing temperature. Multilayer deposition in a magnetic field severely degrades MR performance since it prevents the magnetostatic antiparallel alignment between magnetic grains which occurs in the absence of an applied magnetic field following sample annealing. (C) 1996 American Institute of Physics. C1 MAT RES CORP,ORANGEBURG,NY 10962. NATL INST STAND & TECHNOL,DIV ELECTROMAGNET TECHNOL,BOULDER,CO 80303. RP Dykes, JW (reprint author), QUANTUM PERIPHERALS COLORADO INC,LOUISVILLE,CO 80028, USA. NR 9 TC 3 Z9 3 U1 1 U2 1 PU AMER INST PHYSICS PI WOODBURY PA CIRCULATION FULFILLMENT DIV, 500 SUNNYSIDE BLVD, WOODBURY, NY 11797-2999 SN 0021-8979 J9 J APPL PHYS JI J. Appl. Phys. PD APR 15 PY 1996 VL 79 IS 8 BP 5584 EP 5586 DI 10.1063/1.362249 PN 2A PG 3 WC Physics, Applied SC Physics GA UG877 UT WOS:A1996UG87700417 ER PT J AU Oti, JO Kim, YK AF Oti, JO Kim, YK TI Modeling effects of temperature annealing on giant magnetoresistive response in discontinuous multilayer NiFe/Ag films SO JOURNAL OF APPLIED PHYSICS LA English DT Article; Proceedings Paper CT 40th Annual Conference on Magnetism and Magnetic Materials CY NOV 06-09, 1995 CL PHILADELPHIA, PA SP Amer Inst Phys, IEEE, Magnet Soc, Minerals Met & Mat Soc, Amer Soc Testing & Mat, USN, Off Naval Res, Amer Ceram Soc AB The giant magnetoresistive (GMR) behaviors of discontinuous double-layer giant magnetoresistive films with different microstructure arising from different annealing conditions, are calculated using a numerical micromagnetic model. The effect of magnetic grain growths in the perpendicular and lateral directions in the magnetic layers, and the formation and growth of grain clusters were studied. The GMR responses of the films are analyzed in terms of magnetostatic interactions between the magnetic layers and the microstructural geometric effects on the transport properties of the samples. (C) 1996 American Institute of Physics. C1 QUANTUM PERIPHERALS COLORADO INC,LOUISVILLE,CO 80028. RP Oti, JO (reprint author), NATL INST STAND & TECHNOL,BOULDER,CO 80303, USA. NR 4 TC 2 Z9 2 U1 1 U2 1 PU AMER INST PHYSICS PI WOODBURY PA CIRCULATION FULFILLMENT DIV, 500 SUNNYSIDE BLVD, WOODBURY, NY 11797-2999 SN 0021-8979 J9 J APPL PHYS JI J. Appl. Phys. PD APR 15 PY 1996 VL 79 IS 8 BP 5596 EP 5598 DI 10.1063/1.362253 PN 2A PG 3 WC Physics, Applied SC Physics GA UG877 UT WOS:A1996UG87700421 ER PT J AU Stiles, MD AF Stiles, MD TI Spin-dependent interface transmission and reflection in magnetic multilayers SO JOURNAL OF APPLIED PHYSICS LA English DT Article; Proceedings Paper CT 40th Annual Conference on Magnetism and Magnetic Materials CY NOV 06-09, 1995 CL PHILADELPHIA, PA SP Amer Inst Phys, IEEE, Magnet Soc, Minerals Met & Mat Soc, Amer Soc Testing & Mat, USN, Off Naval Res, Amer Ceram Soc ID OSCILLATORY EXCHANGE INTERACTION; ELECTRON TRANSMISSION; GIANT MAGNETORESISTANCE; INTERLAYER EXCHANGE; LAYERS; FE; CU AB First-principles calculations of transmission and reflection from Ag/Fe, Au/Fe, Cu/Co, and Cu/Ni interfaces show very strong spin dependence that differs significantly from expectations based on free electron approximations. The results can be used to understand both the giant magnetoresistance and the oscillatory exchange coupling observed in magnetic multilayers of these materials. The spin dependence of the reflection probabilities is strong enough to give a large giant magnetoresistance even if there is no spin-dependent defect scattering. The calculated reflection amplitudes determine the strength of the oscillatory exchange coupling. RP Stiles, MD (reprint author), NATL INST STAND & TECHNOL,ELECTRON PHYS GRP,GAITHERSBURG,MD 20899, USA. RI Stiles, Mark/K-2426-2012 OI Stiles, Mark/0000-0001-8238-4156 NR 43 TC 113 Z9 113 U1 0 U2 3 PU AMER INST PHYSICS PI WOODBURY PA CIRCULATION FULFILLMENT DIV, 500 SUNNYSIDE BLVD, WOODBURY, NY 11797-2999 SN 0021-8979 J9 J APPL PHYS JI J. Appl. Phys. PD APR 15 PY 1996 VL 79 IS 8 BP 5805 EP 5810 DI 10.1063/1.362195 PN 2B PG 6 WC Physics, Applied SC Physics GA UG878 UT WOS:A1996UG87800076 ER PT J AU Cross, RW Kos, AB AF Cross, RW Kos, AB TI Relaxation in NiFe/Ag giant magnetoresistive devices SO JOURNAL OF APPLIED PHYSICS LA English DT Article; Proceedings Paper CT 40th Annual Conference on Magnetism and Magnetic Materials CY NOV 06-09, 1995 CL PHILADELPHIA, PA SP Amer Inst Phys, IEEE, Magnet Soc, Minerals Met & Mat Soc, Amer Soc Testing & Mat, USN, Off Naval Res, Amer Ceram Soc AB Giant magnetoresistance was measured as a function of time and device size for patterned NiFe/Ag multilayer films. The sputtered NiFe/Ag multilayers were postannealed at 340 degrees C for 5 min in order to produce a change in resistivity Delta rho/rho of 5% in a saturating field of 4 kA/m (50 Oe). The microstructure of these films is believed to be discontinuous due to Ag bridging through the NiFe grain boundaries after the anneal. The films were fabricated into rectangular stripes with Au current lead, and then exposed to a magnetic field pulse to measure the time response of the resistance, characterized by a time constant tau, from the relation Delta R(t)=Delta R(o)e(-t/tau). An apparatus was developed to produce a magnetic field pulse up to 8 kA/m (100 Oe) with a turn-on/off time constant of 10 mu s. The response of the NiFe/Ag devices saturated quickly with the turn-on step with a time constant nearly equal to that of the field pulse. The response to the turn-off step, however, had a time constant of nearly 300 mu s. When the field is first applied, the torque on the magnetic moments quickly aligns the magnetization. When the field is shut off, however, the torque due to the field drops to 0, so interacting magnetostatic fields from the grains and thermal energy dominate the relaxation process. The average time constant depends on the device size and the applied current density. Relaxation may be detrimental for using this type of material for wad heads where very high data rates are required. RP Cross, RW (reprint author), NATL INST STAND & TECHNOL,DIV ELECTROMAGNET TECHNOL,BOULDER,CO 80303, USA. NR 9 TC 0 Z9 0 U1 1 U2 1 PU AMER INST PHYSICS PI WOODBURY PA CIRCULATION FULFILLMENT DIV, 500 SUNNYSIDE BLVD, WOODBURY, NY 11797-2999 SN 0021-8979 J9 J APPL PHYS JI J. Appl. Phys. PD APR 15 PY 1996 VL 79 IS 8 BP 5820 EP 5822 DI 10.1063/1.362197 PN 2B PG 3 WC Physics, Applied SC Physics GA UG878 UT WOS:A1996UG87800080 ER PT J AU Hu, X Kawazoe, Y AF Hu, X Kawazoe, Y TI New estimation of surface anisotropy SO JOURNAL OF APPLIED PHYSICS LA English DT Article; Proceedings Paper CT 40th Annual Conference on Magnetism and Magnetic Materials CY NOV 06-09, 1995 CL PHILADELPHIA, PA SP Amer Inst Phys, IEEE, Magnet Soc, Minerals Met & Mat Soc, Amer Soc Testing & Mat, USN, Off Naval Res, Amer Ceram Soc ID FILMS AB A micromagnetic study for the spin-reorientation transition in ultrathin magnetic films is reported. Phase diagrams of the magnetization configuration are presented. Scaling relations among the film thickness, exchange coupling, and magnetic anisotropies are revealed. Formulas are given for the energy stored in the film per unit area, which enable one to evaluate the surface anisotropy by ferromagnetic resonance techniques. (C) 1996 American Institute of Physics. C1 NATL INST STAND & TECHNOL,BOULDER,CO 80303. TOHOKU UNIV,INST MAT RES,SENDAI,MIYAGI 98077,JAPAN. RP Hu, X (reprint author), TOHOKU UNIV,MAT RES INST,SENDAI,MIYAGI 98077,JAPAN. RI Kawazoe, Yoshiyuki/C-2998-2011 NR 11 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 APR 15 PY 1996 VL 79 IS 8 BP 5842 EP 5844 DI 10.1063/1.362143 PN 2B PG 3 WC Physics, Applied SC Physics GA UG878 UT WOS:A1996UG87800091 ER PT J AU Lynn, JW Huang, Q Sinha, SK Hossain, Z Gupta, LC Nagarajan, R Godart, C AF Lynn, JW Huang, Q Sinha, SK Hossain, Z Gupta, LC Nagarajan, R Godart, C TI Neutron scattering studies of the magnetic order in RNi(2)B(2)C SO JOURNAL OF APPLIED PHYSICS LA English DT Article; Proceedings Paper CT 40th Annual Conference on Magnetism and Magnetic Materials CY NOV 06-09, 1995 CL PHILADELPHIA, PA SP Amer Inst Phys, IEEE, Magnet Soc, Minerals Met & Mat Soc, Amer Soc Testing & Mat, USN, Off Naval Res, Amer Ceram Soc AB Neutron diffraction has been used to investigate the magnetic order of RNi(2)B(2)C. For R=Er the system orders antiferromagnetically at T-N=6.8 K, and this long range order coexists with superconductivity (T-c=11 K). The magnetic structure is an incommensurate, transversely polarized spin-density-wave state, with the modulation wave vector delta along the a axis and the moments along b. delta has a temperature-independent value of 0.5526 (2 pi/a), with the structure squaring up at low temperatures. For R=Ho the moments also prefer to reside in the a-b plane, but initially an incommensurate c-axis spiral state forms upon cooling, with T-N approximate to T-C approximate to 8 K. This c-axis spiral consists of ferromagnetic sheets of holmium moments in the a-b plane, but with each sheet rotated by similar to 163 degrees as one proceeds along the c axis. Small a-axis peaks are also observed above the reentrant superconducting transition over a narrow temperature range, but the c-axis peaks dominate. Just below the reentrant transition at similar to 5 K the magnetic system locks-in to a simple commensurate antiferromagnetic structure, which permits superconductivity to be restored. The c-axis spiral, the a-axis component, the commensurate antiferromagnetic structure, and the superconducting phase are all in a delicate balance energetically, and this balance may be easily shifted by subtle changes in composition, magnetic field, and pressure. DyNi2B2C orders antiferromagnetically at T-N=11 K, with the same commensurate antiferromagnetic structure as found for the holmium material at low temperature. The existence of superconductivity in some samples of DyNi2B2C is consistent with the antiferromagnetic structure observed. (C) 1996 American Institute of Physics. C1 UNIV MARYLAND,COLLEGE PK,MD 20742. ARGONNE NATL LAB,ARGONNE,IL 60439. TATA INST FUNDAMENTAL RES,BOMBAY 400005,MAHARASHTRA,INDIA. CNRS,UPR 210,F-92195 MEUDON,FRANCE. RP Lynn, JW (reprint author), NIST,DIV REACTOR RADIAT,GAITHERSBURG,MD 20899, USA. NR 18 TC 19 Z9 20 U1 0 U2 1 PU AMER INST PHYSICS PI WOODBURY PA CIRCULATION FULFILLMENT DIV, 500 SUNNYSIDE BLVD, WOODBURY, NY 11797-2999 SN 0021-8979 J9 J APPL PHYS JI J. Appl. Phys. PD APR 15 PY 1996 VL 79 IS 8 BP 5857 EP 5859 DI 10.1063/1.362150 PN 2B PG 3 WC Physics, Applied SC Physics GA UG878 UT WOS:A1996UG87800098 ER PT J AU Herbst, JF Fuerst, CD McMichael, RD AF Herbst, JF Fuerst, CD McMichael, RD TI Structural, magnetic, and magnetocaloric properties of (Hf0.83Ta0.17)Fe-2+x materials SO JOURNAL OF APPLIED PHYSICS LA English DT Article; Proceedings Paper CT 40th Annual Conference on Magnetism and Magnetic Materials CY NOV 06-09, 1995 CL PHILADELPHIA, PA SP Amer Inst Phys, IEEE, Magnet Soc, Minerals Met & Mat Soc, Amer Soc Testing & Mat, USN, Off Naval Res, Amer Ceram Soc ID HF1-XTAXFE2 AB We have investigated the sensitivity of structural, magnetic, and magnetocaloric properties of (Hf0.83Ta0.17)Fe-2+x alloys (x=-0.18, -0.09, -0.02, 0.00, 0.09, 0.26) to Fe content. As-cast samples for all x consist essentially exclusively of hexagonal MgZn2-type material. Via magnetization and differential scanning calorimetry measurements we find that all the alloys except x=0.26 feature both a ferromagnetic-->antiferromagnetic (FM-->AFM) transition at temperature T-0 and a Neel transition. The most abrupt FM-->AFM transition occurs in the x=-0.02 material which also exhibits the lowest T-0 and largest low-temperature moment. We report a magnetocaloric property the field-induced entropy change Delta S, for the x=0.00 and x=+/-0.09 alloys. (C) 1996 American Institute of Physics. C1 NATL INST STAND & TECHNOL,GAITHERSBURG,MD 20899. RP Herbst, JF (reprint author), GM CORP,DEPT PHYS,CTR RES & DEV,30500 MOUND RD,WARREN,MI 48090, USA. RI McMichael, Robert/J-8688-2012; OI McMichael, Robert/0000-0002-1372-664X NR 8 TC 22 Z9 25 U1 2 U2 5 PU AMER INST PHYSICS PI WOODBURY PA CIRCULATION FULFILLMENT DIV, 500 SUNNYSIDE BLVD, WOODBURY, NY 11797-2999 SN 0021-8979 J9 J APPL PHYS JI J. Appl. Phys. PD APR 15 PY 1996 VL 79 IS 8 BP 5998 EP 6000 DI 10.1063/1.362133 PN 2B PG 3 WC Physics, Applied SC Physics GA UG878 UT WOS:A1996UG87800150 ER PT J AU Shull, RD Cline, JP Baker, I Liu, F AF Shull, RD Cline, JP Baker, I Liu, F TI Identification of a high-temperature magnetic phase transition in ball-milled and compacted nanocrystalline Fe-Cu alloys SO JOURNAL OF APPLIED PHYSICS LA English DT Article; Proceedings Paper CT 40th Annual Conference on Magnetism and Magnetic Materials CY NOV 06-09, 1995 CL PHILADELPHIA, PA SP Amer Inst Phys, IEEE, Magnet Soc, Minerals Met & Mat Soc, Amer Soc Testing & Mat, USN, Off Naval Res, Amer Ceram Soc ID GIANT MAGNETORESISTANCE AB Fe-x-Cu-100-x alloys (40 less than or equal to x less than or equal to 90) prepared by ball milling nominally pure (99%) Fe and Cu powders and warm compacted (at similar to 300 degrees C) were investigated by differential scanning calorimetry, scanning electron microscopy, x-ray diffraction, and magnetic susceptibility measurements. Both fee and bce diffraction peaks (indicative of pure Fe and Cu) showed that the mixtures were still two phase even after milling for 400 h, and that they were comprised of 6-10 nm diameter grains. Surprisingly, however, calorimetric measurements indicate the presence of a large endothermic peak for these nanocrystalline composites on heating near 600 degrees C and an exothermic peak near 400 degrees C on cooling. Magnetic measurements show that these materials are ferromagnetic at room temperature and remain so (with decreasing saturation magnetization) up to near the Curie point of alpha-Fe, 770 degrees C. However, near 600 degrees C on heating (and also near 400 degrees C on cooling), the magnetic susceptibility indicates the existence of a magnetic phase change. High-temperature x-ray diffraction data show these effects are due to the oxidation of Fe to form magnetite which subsequently decomposes into wustite. The thermal hysteresis observed in the magnetic and thermal data is due to the sluggishness of the latter transformation. Furthermore, heating to temperatures in excess of 600 degrees C results in the dissolution of Cu into the iron oxides which does not reprecipitate on cooling. (C) 1996 American Institute of Physics. C1 DARTMOUTH COLL,THAYER SCH ENGN,HANOVER,NH 03755. RP Shull, RD (reprint author), NATL INST STAND & TECHNOL,MAT SCI & ENGN LAB,GAITHERSBURG,MD 20899, USA. RI Shull, Robert/F-5971-2013 NR 16 TC 6 Z9 6 U1 0 U2 2 PU AMER INST PHYSICS PI WOODBURY PA CIRCULATION FULFILLMENT DIV, 500 SUNNYSIDE BLVD, WOODBURY, NY 11797-2999 SN 0021-8979 J9 J APPL PHYS JI J. Appl. Phys. PD APR 15 PY 1996 VL 79 IS 8 BP 6028 EP 6030 DI 10.1063/1.361895 PN 2B PG 3 WC Physics, Applied SC Physics GA UG878 UT WOS:A1996UG87800160 ER PT J AU Nikitenko, VI Gornakov, VS Dedukh, LM Khapikov, AF Bennett, LH McMichael, RD Swartzendruber, LJ Shapiro, AJ Donahue, MJ Matveev, VN Levashov, VI AF Nikitenko, VI Gornakov, VS Dedukh, LM Khapikov, AF Bennett, LH McMichael, RD Swartzendruber, LJ Shapiro, AJ Donahue, MJ Matveev, VN Levashov, VI TI Magneto-optical indicator film (MOIF) microscopy of granular and layer structures SO JOURNAL OF APPLIED PHYSICS LA English DT Meeting Abstract C1 RUSSIAN ACAD SCI,INST SOLID STATE PHYS,CHERNOGOLOVKA 142432,RUSSIA. NATL INST STAND & TECHNOL,GAITHERSBURG,MD 20899. RUSSIAN ACAD SCI,INST MICROELECTR TECHNOL & HIGH PURITY MAT,CHERNOGOLOVKA 142432,RUSSIA. RI McMichael, Robert/J-8688-2012 NR 0 TC 3 Z9 3 U1 0 U2 2 PU AMER INST PHYSICS PI WOODBURY PA CIRCULATION FULFILLMENT DIV, 500 SUNNYSIDE BLVD, WOODBURY, NY 11797-2999 SN 0021-8979 J9 J APPL PHYS JI J. Appl. Phys. PD APR 15 PY 1996 VL 79 IS 8 BP 6073 EP 6073 DI 10.1063/1.362096 PN 2B PG 1 WC Physics, Applied SC Physics GA UG878 UT WOS:A1996UG87800179 ER PT J AU Celotta, RJ Gupta, R Scholten, RE McClelland, JJ AF Celotta, RJ Gupta, R Scholten, RE McClelland, JJ TI Nanostructure fabrication via laser-focused atomic deposition SO JOURNAL OF APPLIED PHYSICS LA English DT Article; Proceedings Paper CT 40th Annual Conference on Magnetism and Magnetic Materials CY NOV 06-09, 1995 CL PHILADELPHIA, PA SP Amer Inst Phys, IEEE, Magnet Soc, Minerals Met & Mat Soc, Amer Soc Testing & Mat, USN, Off Naval Res, Amer Ceram Soc ID RESONANCE-RADIATION PRESSURE; NANOMETER-SCALE MAGNETS; LIGHT; LENS AB Nanostructured materials and devices will play an important role in a variety of future technologies, including magnetics. We describe a method for nanostructure fabrication based on the use of laser light to focus neutral atoms. The method uses neither a mask nor a resist, but relies-on the direct deposition of atoms to form permanent structures. Since the atomic de Broglie wavelength is of picometer order, the size of structures produced is not significantly limited by diffraction, as in optical lithography. Lines as narrow as 38 nm full width at half maximum spaced by 213 nm have been produced and we have demonstrated the production of a two-dimensional array of dots. The highly parallel process of nanostructure formation and the intrinsic accuracy of the optical wavelength that determines structure spacing suggest a number of interesting applications, including calibration standards for various types of microscopy, lithography, and micromeasurement systems. Possible magnetic applications include the production of arrays of magnetic elements, laterally structured giant magnetoresistive devices, and the patterning of magnetic media. RP Celotta, RJ (reprint author), NATL INST STAND & TECHNOL,ELECTRON PHYS GRP,GAITHERSBURG,MD 20899, USA. RI Scholten, Robert/A-8586-2013; McClelland, Jabez/A-2358-2015 OI Scholten, Robert/0000-0002-2337-8036; McClelland, Jabez/0000-0001-5672-5965 NR 33 TC 38 Z9 42 U1 0 U2 2 PU AMER INST PHYSICS PI WOODBURY PA CIRCULATION FULFILLMENT DIV, 500 SUNNYSIDE BLVD, WOODBURY, NY 11797-2999 SN 0021-8979 J9 J APPL PHYS JI J. Appl. Phys. PD APR 15 PY 1996 VL 79 IS 8 BP 6079 EP 6083 DI 10.1063/1.362099 PN 2B PG 5 WC Physics, Applied SC Physics GA UG878 UT WOS:A1996UG87800183 ER PT J AU Sanders, SC Cross, RW Russek, SE Roshko, A Oti, JO AF Sanders, SC Cross, RW Russek, SE Roshko, A Oti, JO TI Size effects and giant magnetoresistance in unannealed NiFe/Ag multilayer stripes SO JOURNAL OF APPLIED PHYSICS LA English DT Article; Proceedings Paper CT 40th Annual Conference on Magnetism and Magnetic Materials CY NOV 06-09, 1995 CL PHILADELPHIA, PA SP Amer Inst Phys, IEEE, Magnet Soc, Minerals Met & Mat Soc, Amer Soc Testing & Mat, USN, Off Naval Res, Amer Ceram Soc AB We have observed giant magnetoresistance (GMR) in unannealed NiFe/Ag multilayer thin-film stripes, Rectangular stripes having constant thickness and a constant 11:1 length-to-width aspect ratio, but varying widths down to 0.5 mu m, were measured. Two types of multilayer configurations were tested, a system of five NiFe/Ag bilayers with 5.5-nm-thick Ag spacer layers, and a system of nine bilayers with 4.4-nm-thick Ag layers. In contrast to the characteristic of annealed NiFe/Ag multilayer stripes, the unnannealed stripes produced increasing GMR ratios for decreasing stripe sizes, with the 0.5-mu m-wide stripe of the five-bilayer system exhibiting a Delta R/R of 2.5%. Barkhausen noise and response broadening also increased with decreasing stripe size, however. The results are discussed in terms of magnetostatic coupling of the NiFe layers within the stripes. RP Sanders, SC (reprint author), NATL INST STAND & TECHNOL,ELECTROMAGNET TECHNOL DIV,BOULDER,CO 80303, USA. NR 12 TC 6 Z9 6 U1 1 U2 2 PU AMER INST PHYSICS PI WOODBURY PA CIRCULATION FULFILLMENT DIV, 500 SUNNYSIDE BLVD, WOODBURY, NY 11797-2999 SN 0021-8979 J9 J APPL PHYS JI J. Appl. Phys. PD APR 15 PY 1996 VL 79 IS 8 BP 6240 EP 6242 DI 10.1063/1.362017 PN 2B PG 3 WC Physics, Applied SC Physics GA UG878 UT WOS:A1996UG87800236 ER PT J AU Oti, JO Cross, RW Russek, SE Kim, YK AF Oti, JO Cross, RW Russek, SE Kim, YK TI Simulating device size effects on magnetization pinning mechanisms in spin valves SO JOURNAL OF APPLIED PHYSICS LA English DT Article; Proceedings Paper CT 40th Annual Conference on Magnetism and Magnetic Materials CY NOV 06-09, 1995 CL PHILADELPHIA, PA SP Amer Inst Phys, IEEE, Magnet Soc, Minerals Met & Mat Soc, Amer Soc Testing & Mat, USN, Off Naval Res, Amer Ceram Soc AB The effects of magnetostatic interactions on the giant magnetoresistive (GMR) response of NiFe/Cu/NiFe spin valves are studied using an analytical model. The model is applicable to devices small enough for the magnetic layers to exhibit single-domain behavior. Devices having lengths in the track-width direction of 10 mu m and interlayer separations of 4.5 nm are studied. Stripe heights are varied from 0.5 to 2 mu m. The magnetization of one magnetic layer is pinned by a transverse pinning field that is varied from 0 to 24 kA/m (300 Oe). GMR curves for transverse fields are calculated. At zero external field the magnetization of the layers shows a tendency to align themselves antiparallel in the transverse direction. This results in an offset from the ideal biasing of the device. Broadening of the curves due to shape anisotropy occurs with decreasing stripe height and increasing magnetic layer thickness, and the magnetization in the pinned layer becomes less stable. (C) 1996 American Institute of Physics. C1 QUANTUM PERIPHERALS COLORADO INC,LOUISVILLE,CO 80028. RP Oti, JO (reprint author), NATL INST STAND & TECHNOL,325 BROADWAY,BOULDER,CO 80303, USA. NR 7 TC 9 Z9 9 U1 0 U2 2 PU AMER INST PHYSICS PI WOODBURY PA CIRCULATION FULFILLMENT DIV, 500 SUNNYSIDE BLVD, WOODBURY, NY 11797-2999 SN 0021-8979 J9 J APPL PHYS JI J. Appl. Phys. PD APR 15 PY 1996 VL 79 IS 8 BP 6386 EP 6388 DI 10.1063/1.362692 PN 2B PG 3 WC Physics, Applied SC Physics GA UG878 UT WOS:A1996UG87800295 ER PT J AU Hopkins, PF Moreland, J Malhotra, SS Liou, SH AF Hopkins, PF Moreland, J Malhotra, SS Liou, SH TI Superparamagnetic magnetic force microscopy tips SO JOURNAL OF APPLIED PHYSICS LA English DT Article; Proceedings Paper CT 40th Annual Conference on Magnetism and Magnetic Materials CY NOV 06-09, 1995 CL PHILADELPHIA, PA SP Amer Inst Phys, IEEE, Magnet Soc, Minerals Met & Mat Soc, Amer Soc Testing & Mat, USN, Off Naval Res, Amer Ceram Soc ID FILMS AB We report on magnetic force microscopy (MFM) images of a thin-film magnetic recording head taken using batch micromachined silicon tips coated with nanocomposite Fe-60(SiO2)(40) and Fe-70(SiO2)(30) films. The small Fe grain size (<10 nm) and dilute Fe volume fraction (0.29-0.4) of these granular films produce tip coatings of low remanence and essentially zero coercivity, reduced by the superparamagnetic properties of these films. We have used these tips to obtain MFM images of the write field of the head with high spatial and magnetic-field resolution. In comparison to images taken using commercial Co85Cr15-coated tips, these MFM images show reduced tip memory effects and clearly delineate the gap field from the pole pieces. (C) 1996 American Institute of Physics. C1 NATL INST STAND & TECHNOL,BOULDER,CO 80303. UNIV NEBRASKA,DEPT PHYS & ASTRON,LINCOLN,NE 68588. NR 11 TC 24 Z9 25 U1 0 U2 5 PU AMER INST PHYSICS PI WOODBURY PA CIRCULATION FULFILLMENT DIV, 500 SUNNYSIDE BLVD, WOODBURY, NY 11797-2999 SN 0021-8979 J9 J APPL PHYS JI J. Appl. Phys. PD APR 15 PY 1996 VL 79 IS 8 BP 6448 EP 6450 DI 10.1063/1.361969 PN 2B PG 3 WC Physics, Applied SC Physics GA UG878 UT WOS:A1996UG87800319 ER PT J AU Li, WH Lin, YF Wu, SY Hsieh, WT Lee, KC Lynn, JW Lai, CC Ku, HC AF Li, WH Lin, YF Wu, SY Hsieh, WT Lee, KC Lynn, JW Lai, CC Ku, HC TI Cu spin reorientation in Tl(BaSr)PrCu2O7 SO JOURNAL OF APPLIED PHYSICS LA English DT Article; Proceedings Paper CT 40th Annual Conference on Magnetism and Magnetic Materials CY NOV 06-09, 1995 CL PHILADELPHIA, PA SP Amer Inst Phys, IEEE, Magnet Soc, Minerals Met & Mat Soc, Amer Soc Testing & Mat, USN, Off Naval Res, Amer Ceram Soc ID CRYSTAL-STRUCTURE; TLBA2YCU2O7 AB The Cu spins in TlBa2PrCu2O7 order at T-N approximate to 370 K with a spin structure that is collinear and is characterized by the {1/21/21} wave vector, where the nearest neighbor spins are aligned antiparallel along all three crystallographic directions. Lf 50% of the Ba atoms are randomly replaced by the smaller Sr atoms to form Tl(BaSr)PrCu2O7, the T-N of the Cu spins reduces to 350 K but the magnetic structure that forms below T-N is the same. However, at T approximate to 20 K the Cu spins undergo a change in structure, and the spin arrangement is then characterized by the {1/21/21/2} wave vector below T approximate to 12 K. The ground state spin structure of the Cu ions in Tl(BaSr)PrCu2O7 is hence noncollinear, where the spin directions of the nearest neighbor Cu ions in the nb plane remain collinear and antiparallel while along the c axis they are orthogonal. These results demonstrate that the atoms in the BaO layers are also actively participating in the coupling between the Cu ions. (C) 1996 American Institute of Physics. C1 NIST,DIV REACTOR RADIAT,GAITHERSBURG,MD 20899. NATL TSING HUA UNIV,DEPT PHYS,HSINCHU 300,TAIWAN. RP Li, WH (reprint author), NATL CENT UNIV,DEPT PHYS,CHUNGLI 32054,TAIWAN. NR 8 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 APR 15 PY 1996 VL 79 IS 8 BP 6568 EP 6570 DI 10.1063/1.361883 PN 2B PG 3 WC Physics, Applied SC Physics GA UG878 UT WOS:A1996UG87800366 ER PT J AU Hansen, DV Bezdek, HF AF Hansen, DV Bezdek, HF TI On the nature of decadal anomalies in North Atlantic sea surface temperature SO JOURNAL OF GEOPHYSICAL RESEARCH-OCEANS LA English DT Article ID OBJECTIVE ANALYSIS; PACIFIC-OCEAN; VARIABILITY; WINTER AB North Atlantic sea surface temperature data from the Comprehensive Ocean-Atmosphere Data Set were used to investigate the behavior of temperature anomalies on multiple-year timescales during the period 1948-1992. Monthly anomaly time series for each 2 degrees square from the equator to 70 degrees N were low-pass filtered at 4 years and normalized by the local standard deviation. Attention is focused on the extreme events, the upper and lower deciles, of the anomaly time series. A 45-year sequence of January maps shows the already familiar phenomena of generally cold conditions prior to 1951, a long warm interval from 1951 through 1967, and again a cold period from 1968 through 1977. The years 1978 through 1982 were largely devoid of persistent strong anomalies, but moderate cold conditions returned during 1983-1986. Warm Conditions dominated the North Atlantic from 1987 onward. Within these thermal epochs, however, a total of five cold anomaly features and nine warm anomaly features have been identified. These features have individual lifetimes of 3 to 10 years. A typical size is 20 degrees of latitude or longitude, but they range from barely detectable to spanning the width of the basin, the latter especially in lower latitudes. Most of the anomalies move long distances along certain preferred paths. These paths generally follow the routes of the subarctic and subtropical gyres. Anomalies originating off North America along the boundary between the gyres move northeastward toward the Norwegian Sea along the approximate route of the North Atlantic Current. Midlatitude anomalies originating at the eastern boundary tend to spread both northward and southward along the coast. The speed of these movements (1-3 km d(-1)) is generally less than the expected speed of the near-surface ocean circulation. Simple ideas about the effects of beta dynamics and air-sea heat exchanges are briefly considered but do not provide a satisfactory explanation for the movements of the anomalies. The long timescale of these extreme events and the continuity of their movements suggest a useful degree of predictability of sea surface temperature based on persistence and propagation of features. C1 NOAA,ATLANTIC OCEANOG & METEOROL LAB,MIAMI,FL 33149. RP Hansen, DV (reprint author), UNIV MIAMI,COOPERAT INST MARINE & ATMOSPHER STUDIES,4600 RICKENBACKER CAUSEWAY,MIAMI,FL 33149, USA. NR 41 TC 100 Z9 100 U1 0 U2 2 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 SN 0148-0227 J9 J GEOPHYS RES-OCEANS JI J. Geophys. Res.-Oceans PD APR 15 PY 1996 VL 101 IS C4 BP 8749 EP 8758 DI 10.1029/95JC03841 PG 10 WC Oceanography SC Oceanography GA UG511 UT WOS:A1996UG51100001 ER PT J AU Tai, CK AF Tai, CK TI Frequency periodograms of altimetric sea level and their geographical variation from 2 years of TOPEX/POSEIDON data SO JOURNAL OF GEOPHYSICAL RESEARCH-OCEANS LA English DT Article ID GULF-STREAM; KUROSHIO EXTENSION; GEOSAT ALTIMETRY; TROPICAL PACIFIC; SATELLITE ALTIMETRY; VARIABILITY; JET; TRANSPORT; OCEAN; TIDES AB Frequency periodograms are estimated from 2 years of TOPEX/POSEIDON altimetric sea levels at crossovers (XOs), where the height measurements are twice as abundant than at non-XO paints. It is shown that the extra set of height measurements is best utilized to reduce aliasing rather than to double the temporal resolution. Least squares fitting with Fourier series handles the problem of missing data and unequal spacing. A global average. power spectrum (area-weighted from spectra at XOs) and average spectra from low-variability as well as high-variability areas are obtained. In addition, regional average spectra are produced for various western boundary currents as well as the Antarctic Circumpolar Current and northeastern equatorial Pacific. All spectra are red and (with few exceptions) have a strong annual peak. Strong annual peaks are present for the northern hemisphere western boundary currents, where enhanced air-sea interaction results in large annual heating/cooling effects. A mechanism of winter cooling proposed by Huang [1990] appears to be consistent with the seasonal movements and intensity of the surface jet, augmenting the annual peak. In contrast, the annual peak is less pronounced in the southern hemisphere western boundary currents, presumably because of smaller annual heating/cooling effects. Detrending of the height time series before the Fourier analysis shows the 2-year sea level trends over the global ocean. The global average is about 4.5 mm/yr after correction for instrumental drift. The data have been treated with orbit and tide error reduction schemes. The frequency spectrum of the orbit correction is white.(as expected) and proves that the orbit error reduction scheme utilized here does not attenuate the ocean signal. RP Tai, CK (reprint author), NOAA,NOS,GEOSCI LAB,N-OES11,1305 E W HIGHWAY,SILVER SPRING,MD 20910, USA. RI Tai, C.K./F-5628-2010 NR 32 TC 3 Z9 3 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 APR 15 PY 1996 VL 101 IS C4 BP 8933 EP 8941 DI 10.1029/96JC00391 PG 9 WC Oceanography SC Oceanography GA UG511 UT WOS:A1996UG51100013 ER PT J AU Overland, JE Stabeno, PJ Salo, S AF Overland, JE Stabeno, PJ Salo, S TI Direct evidence for northward flow on the northwestern Bering Sea shelf SO JOURNAL OF GEOPHYSICAL RESEARCH-OCEANS LA English DT Article ID CHUKCHI SEAS; CIRCULATION; STRAIT AB During the summer of 1994 a satellite-tracked drifter transited from the southeastern Bering Sea slope through Bering Strait by a route westward along the slope and then northward through Anadyr Canyon and Strait. The trajectory emphasizes the importance of a western location of northward flow on the Bering Sea shelf. The transit time was 2 months from Cape Navarin to Bering Strait with northward drift velocities of 5-40 cm/s. RP Overland, JE (reprint author), NOAA,PACIFIC MARINE ENVIRONM LAB,7600 SAND POINT WAY NE,SEATTLE,WA 98115, USA. NR 21 TC 7 Z9 9 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 APR 15 PY 1996 VL 101 IS C4 BP 8971 EP 8976 DI 10.1029/96JC00205 PG 6 WC Oceanography SC Oceanography GA UG511 UT WOS:A1996UG51100016 ER PT J AU Pearce, EM Sawamoto, M Tirrell, DA Amis, EJ AF Pearce, EM Sawamoto, M Tirrell, DA Amis, EJ TI A half-century of the Journal of Polymer Science SO JOURNAL OF POLYMER SCIENCE PART B-POLYMER PHYSICS LA English DT Editorial Material C1 NATL INST STAND & TECHNOL,DIV POLYMERS,GAITHERSBURG,MD 20885. RP Pearce, EM (reprint author), POLYTECH UNIV,HERMAN F MARK POLYMER RES INST,6 METROTECH CTR,BROOKLYN,NY 11201, USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU JOHN WILEY & SONS INC PI NEW YORK PA 605 THIRD AVE, NEW YORK, NY 10158-0012 SN 0887-6266 J9 J POLYM SCI POL PHYS JI J. Polym. Sci. Pt. B-Polym. Phys. PD APR 15 PY 1996 VL 34 IS 5 BP 795 EP 795 DI 10.1002/polb.1996.898 PG 1 WC Polymer Science SC Polymer Science GA UB554 UT WOS:A1996UB55400001 ER PT J AU Ikkai, F Shibayama, M Nomura, S Han, CC AF Ikkai, F Shibayama, M Nomura, S Han, CC TI Complexation of poly(vinyl alcohol)-Congo red aqueous solutions .3. Dynamic light scattering study SO JOURNAL OF POLYMER SCIENCE PART B-POLYMER PHYSICS LA English DT Article DE dynamic light scattering; poly(vinyl alcohol); Congo Red; ion complexation; sol-gel transition ID SOL-GEL TRANSITION; BORATE COMPLEX; POLYVINYL-ALCOHOL); BEHAVIOR; GELATION; FLUCTUATIONS; POLYMER; DECAY AB Mesoscopic structures of poly(vinyl alcohol)-Congo red (PVA-CR) complexes in aqueous solutions were investigated in terms of dynamic light scattering (DLS) technique. The intensity-intensity time correlation function, g((2))(t), was analyzed with an equation including a single and a stretched exponential function. Two diffusion coefficients, D-f (fast) and D-s (slow) were evaluated. D-f was converted to the apparent correlation length, xi(app), via the mode-mode coupling hypothesis. The estimated xi(app) was insensitive to the sol-to-gel transition but decreased with CR concentration. This change may be related to the electrostatic screening effect. On the other hand, D-s oscillates with increasing CR concentration at a specific PVA concentration range. This explains well the reentrant sol-gel-sol-gel transition behavior observed in the PVA-CR systems. D-s seems to represent the mobility of the PVA-CR complexes, which annihilates at the gel point. (C) 1996 John Wiley & Sons, Inc. C1 KYOTO INST TECHNOL,DEPT POLYMER SCI & ENGN,MATSUGASAKI,KYOTO 606,JAPAN. NIST,DIV POLYMER,GAITHERSBURG,MD 20899. RI Shibayama, Mitsuhiro/E-1646-2015 OI Shibayama, Mitsuhiro/0000-0002-8683-5070 NR 33 TC 13 Z9 13 U1 2 U2 7 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 APR 15 PY 1996 VL 34 IS 5 BP 939 EP 945 DI 10.1002/(SICI)1099-0488(19960415)34:5<939::AID-POLB12>3.0.CO;2-C PG 7 WC Polymer Science SC Polymer Science GA UB554 UT WOS:A1996UB55400015 ER PT J AU Xu, Q AF Xu, Q TI Generalized adjoint for physical processes with parameterized discontinuities .1. Basic issues and heuristic examples SO JOURNAL OF THE ATMOSPHERIC SCIENCES LA English DT Article ID VARIATIONAL DATA ASSIMILATION; METEOROLOGICAL OBSERVATIONS; MESOSCALE MODEL; EQUATION; WIND AB Symbolic operations are used together with delta functions to derive the generalized adjoint method for physical processes that contain first-order discontinuities caused by parameterized on/off switches with zero-order discontinuities in the source term. Generalized adjoint solutions are obtained analytically for simple heuristic examples and verified by direct perturbation analyses. Errors due to the conventional treatment with the ''classic'' adjoint method (which ignores the variation of the switch point) are quantified and found to be significant. The classic adjoint method encounters more serious problems when the parameterized process causes on/off oscillations in a numerical integration of the equation. In the limit of a vanishing computational time step, the on/off oscillations approach a marginal state that can be well treated by the generalized adjoint method. It is found that the marginal state imposes a constraint on the perturbation. Three basic issues are raised and addressed concerning whether and how discontinuous on/off switches may affect (i) the existence of adjoint and gradient, (ii) the nonlinearity and sensitivity, and (iii) the bifurcation properties. it is found that the gradient becomes discontinuous and has a regular (or singular) jump at a non-bifurcated (or bifurcated) branch point but still can be correctly computed by the generalized adjoint. Unless the switch is branched at a bifurcation point, its nonlinearity is local and lower by a half-order than the quadratic nonlinearity. The linear sensitivity of the solution to the initial state will be reduced (or enhanced) by a discontinuous switch if the perturbation is reduced (or amplified) by the switch. Smoothing modifications of switches with their jumps fitted by continuous functions are examined for their effectiveness in making the switches suitable for the classic adjoint method. It is found that fitting the jump with a continuous function of time (control variable) cannot (can) make the switch suitable for the classic adjoint method. RP Xu, Q (reprint author), UNIV OKLAHOMA,CIMMS,NOAA,100 E BOYD,RM 1110,NORMAN,OK 73019, USA. NR 33 TC 84 Z9 95 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 APR 15 PY 1996 VL 53 IS 8 BP 1123 EP 1142 DI 10.1175/1520-0469(1996)053<1123:GAFPPW>2.0.CO;2 PG 20 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA UF709 UT WOS:A1996UF70900004 ER PT J AU Xu, Q AF Xu, Q TI Generalized adjoint for physical processes with parameterized discontinuities .2. Vector formulations and matching conditions SO JOURNAL OF THE ATMOSPHERIC SCIENCES LA English DT Article ID VARIATIONAL DATA ASSIMILATION; METEOROLOGICAL OBSERVATIONS; MESOSCALE MODEL; EQUATION; WIND AB Generalized tangent linear and adjoint equations are derived for a vector equation that contains a parameterized source term with discontinuous on/off switches controlled by a threshold condition. As an extension of Part I, the key results here include a pair of interface matching conditions for coupled tangent linear and adjoint vectors across a switch point. Each matching condition can be expressed in either a forward form or a backward form that connects the vector values on the two sides of the switch point via a forward- or backward-matching matrix. The forward- and backward-matching matrices are mutually invertible. The backward/forward-matching matrix for the adjoint vector is the transpose of the forward/backward matrix for the tangent Linear vector. By using the matching condition, the classic tangent linear (or adjoint) solution can be extended through a switch point, so a fundamental set of generalized tangent linear (or adjoint) solutions can be constructed, which leads to an explicit expression of the generalized tangent linear (or adjoint) resolvent-the inverse of the generalized tangent Linear (or adjoint) operator. The generalized resolvents provide a complete description of the adjoint properties and yield an integral formulation for the gradient of the costfunction. When the parameterized process produces strong negative feedback, on-off oscillations can be produced numerically in vector forms due to essentially the same mechanism as previously illustrated by one-dimensional examples, and the oscillatory states yield to a marginal state in the limit of vanishing time steps in the numerical integration. Marginal states can impose multiple constraints on the tangent linear vector and thus cause multiple reductions in the effective dimension of the data-forcing vector in the backward integration of the adjoint equation. This extends the previous one-dimensional results. RP Xu, Q (reprint author), UNIV OKLAHOMA,CIMMS,NOAA,100 E BOYD,RM 1110,NORMAN,OK 73019, USA. NR 32 TC 28 Z9 31 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 APR 15 PY 1996 VL 53 IS 8 BP 1143 EP 1155 DI 10.1175/1520-0469(1996)053<1143:GAFPPW>2.0.CO;2 PG 13 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA UF709 UT WOS:A1996UF70900005 ER PT J AU Li, J Ramaswamy, V AF Li, J Ramaswamy, V TI Four-stream spherical harmonic expansion approximation for solar radiative transfer SO JOURNAL OF THE ATMOSPHERIC SCIENCES LA English DT Article ID INHOMOGENEOUS ATMOSPHERES; MULTIPLE-SCATTERING; 2-STREAM; IRRADIANCE AB This paper presents a four-stream extension of the delta-Eddington approximation by considering the higher-order spherical harmonic expansion in radiative intensity. By using the orthogonality relation of the spherical harmonic functions, the derivation of the solution is fairly straightforward. Calculations show that the delta-four-stream spherical harmonic expansion approximation can reduce the errors in reflection, transmission, and absorption substantially in comparison with the delta-Eddington approximation. For the conservative scattering case, the error of the new model is generally less than 1% for optical thicknesses greater than unity except for grazing incident solar beam. For nonconservative scattering cases (single scattering albedo omega = 0.9), the error is less than 5% for optical thicknesses greater than unity, in contrast to errors of up to 20% or more under the delta-Eddington approximation. This model can also predict the azimuthally averaged intensity to a good degree of accuracy. The computational time for this model is not as intensive as for the rigorous numerical methods, owing to the analytical form of the derived solution. RP Li, J (reprint author), PRINCETON UNIV,NOAA,GEOPHYS FLUID DYNAM LAB,ATMOSPHER & OCEAN SCI PROGRAM,POB 308,PRINCETON,NJ 08542, USA. RI Li, Jiangnan/J-6262-2016 NR 24 TC 34 Z9 40 U1 2 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 APR 15 PY 1996 VL 53 IS 8 BP 1174 EP 1186 DI 10.1175/1520-0469(1996)053<1174:FSSHEA>2.0.CO;2 PG 13 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA UF709 UT WOS:A1996UF70900007 ER PT J AU Jaruga, P Dizdaroglu, M AF Jaruga, P Dizdaroglu, M TI Repair of products of oxidative DNA base damage in human cells SO NUCLEIC ACIDS RESEARCH LA English DT Article ID ESCHERICHIA-COLI; IONIZING-RADIATION; SUBSTRATE-SPECIFICITY; MAMMALIAN-CELLS; 8-HYDROXYGUANINE; GLYCOSYLASE; RESIDUES; SITE; MUTAGENESIS; RADICALS AB Oxidative DNA damage is the most frequent type of damage encountered by aerobic cells and may play an important role in biological processes such as mutagenesis, carcinogenesis and aging in humans. Oxidative damage generates a myriad of modifications in DNA. We investigated the cellular repair of DNA base damage products in DNA of cultured human lymphoblast cells, which were exposed to oxidative stress by H2O2. This DNA-damaging agent is known to cause base modifications in genomic DNA of mammalian cells [Dizdaroglu, M., Nackerdien, Z., Chao, B.-C., Gajewski, E. and Rao, G. (1991) Arch. Biochem. Biophys, 285; 388-390]. Following treatment with H2O2, the culture medium was freed from H2O2 and cells were incubated for time periods ranging from 10 min to 6 h. DNA was isolated from control cells, hydrogen peroxide-treated cells and cells incubated after H2O2 exposure, DNA samples were analyzed by gas chromatography/isotope-dilution mass spectrometry Eleven modified bases were identified and quantified; The results showed a significant formation of these DNA base products upon H2O2-treatment of cells. Subsequent incubation of cells caused a time-dependent excision of these products from cellular DNA, The cell viability did not change significantly by various treatments. There were distinct differences between the kinetics of excision of individual products. The observed excisions were attributed to DNA repair in cells. The rate of repair of purine lesions was slower than that of pyrimidine lesions. Most of the identified products are known to possess Various premutagenic properties. The results of this work may contribute to the understanding of the cellular repair of oxidative DNA damage inhuman and other mammalian cells. C1 NATL INST STAND & TECHNOL,CHEM SCI & TECHNOL LAB,GAITHERSBURG,MD 20899. MED ACAD,DEPT CLIN BIOCHEM,PL-85094 BYDGOSZCZ,POLAND. RI Jaruga, Pawel/M-4378-2015 NR 40 TC 203 Z9 210 U1 1 U2 7 PU OXFORD UNIV PRESS UNITED KINGDOM PI OXFORD PA WALTON ST JOURNALS DEPT, OXFORD, ENGLAND OX2 6DP SN 0305-1048 J9 NUCLEIC ACIDS RES JI Nucleic Acids Res. PD APR 15 PY 1996 VL 24 IS 8 BP 1389 EP 1394 DI 10.1093/nar/24.8.1389 PG 6 WC Biochemistry & Molecular Biology SC Biochemistry & Molecular Biology GA UH370 UT WOS:A1996UH37000001 PM 8628669 ER PT J AU Shirley, EL Terminello, LJ Klepeis, JE Himpsel, FJ AF Shirley, EL Terminello, LJ Klepeis, JE Himpsel, FJ TI Detailed theoretical photoelectron angular distributions for LiF(100) SO PHYSICAL REVIEW B LA English DT Article ID NORM-CONSERVING PSEUDOPOTENTIALS; CORE POLARIZATION POTENTIALS; GROUND-STATE; ABINITIO CALCULATIONS; VALENCE CORRELATION; LITHIUM-FLUORIDE; BRILLOUIN-ZONE; SPECIAL POINTS; BAND-GAPS; ELECTRON AB We model photoelectron angular distributions obtained earlier by Himpsel et al, [Phys. Rev, Lett. 68, 3611 (1992)] for the F 2p bands in LiF(100). The F 2p states are treated within a many-body, quasiparticle approach, and a nearly-free-electron model is presented for the description of conduction-band states relevant to the photoemission process. In the quasiparticle results, we find a band gap of 14.4 eV and a F 2p bandwidth of 3.6 eV, in satisfactory agreement with experimental values of 14.2 and 3.5 eV for these respective quantities. A method for computing photoelectron angular distributions is presented, followed by a comparison of simulated and measured photoelectron angular distributions for several parts of the three-dimensional Brillouin zone. In this comparison, constant-energy contours in the F 2p bands are clearly portrayed in both theoretical and experimental images. Using the model, we also identify the origin of a Brillouin-zone-dependent intensity variation for equivalent valence states, i.e., states which are related by reflection through a (010)-type Bragg plane and which lie close to such a plane. C1 LAWRENCE LIVERMORE NATL LAB, LIVERMORE, CA 94551 USA. IBM CORP, THOMAS J WATSON RES CTR, YORKTOWN HTS, NY 10598 USA. RP Shirley, EL (reprint author), NIST, PHYS LAB, RADIOMETR PHYS DIV, GAITHERSBURG, MD 20899 USA. NR 70 TC 47 Z9 48 U1 3 U2 5 PU AMER PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 1098-0121 EI 1550-235X J9 PHYS REV B JI Phys. Rev. B PD APR 15 PY 1996 VL 53 IS 15 BP 10296 EP 10309 DI 10.1103/PhysRevB.53.10296 PG 14 WC Physics, Condensed Matter SC Physics GA UJ296 UT WOS:A1996UJ29600117 ER PT J AU Oates, CW Vogel, KR Hall, JL AF Oates, CW Vogel, KR Hall, JL TI High precision linewidth measurement of laser-cooled atoms: Resolution of the Na 3p P-2(3/2) lifetime discrepancy SO PHYSICAL REVIEW LETTERS LA English DT Article ID SODIUM; SPECTROSCOPY AB We report resolution of the 1% discrepancy between theory and experiment for the lifetime of the first excited state of Na. Determining the atomic lifetime by a novel method, we have measured the natural linewidth of the 3(2)S(1/2) --> 3(2)P(3/2) transition with <0.25% accuracy through precision spectroscopy on an optically prepared sample of ultracold, two-level atoms. The resulting 3(2)P(3/2) lifetime of 16.237(35) ns disagrees with previous time-domain measurements but is in good agreement with recent calculations and a new fast beam result. C1 NATL INST STAND & TECHNOL,BOULDER,CO 80309. RP Oates, CW (reprint author), UNIV COLORADO,JOINT INST LAB ASTROPHYS,BOULDER,CO 80309, USA. NR 18 TC 83 Z9 83 U1 1 U2 6 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 0031-9007 J9 PHYS REV LETT JI Phys. Rev. Lett. PD APR 15 PY 1996 VL 76 IS 16 BP 2866 EP 2869 DI 10.1103/PhysRevLett.76.2866 PG 4 WC Physics, Multidisciplinary SC Physics GA UF379 UT WOS:A1996UF37900010 ER PT J AU Raghavachari, K Chabal, YJ Struck, LM AF Raghavachari, K Chabal, YJ Struck, LM TI Vibrational interactions at surfaces: H2O on Si(100) SO CHEMICAL PHYSICS LETTERS LA English DT Article ID CORRELATION-ENERGY; ELECTRON-GAS; APPROXIMATION; EXCHANGE; SI(111); WATER AB The structures and vibrational frequencies of water dissociatively adsorbed on a Si(100)-(2 X 1) surface are investigated by accurate quantum chemical cluster calculations. This Letter addresses the experimentally observed puzzling isotopic shift from the Si-OH stretch (825 cm(-1)) to the Si-OD stretch (840 cm(-1)) measured upon D2O exposure, which is opposite to the decrease in frequency expected from simple mass arguments. Our calculations show that vibrational interactions between the Si-OH stretch and the Si-O-H bending modes account for all the observed effects. C1 NIST,GAITHERSBURG,MD 20899. RP Raghavachari, K (reprint author), AT&T BELL LABS,MURRAY HILL,NJ 07974, USA. RI Chabal, Yves/A-5998-2011 OI Chabal, Yves/0000-0002-6435-0347 NR 22 TC 54 Z9 54 U1 0 U2 1 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0009-2614 J9 CHEM PHYS LETT JI Chem. Phys. Lett. PD APR 12 PY 1996 VL 252 IS 3-4 BP 230 EP 235 DI 10.1016/0009-2614(96)00096-6 PG 6 WC Chemistry, Physical; Physics, Atomic, Molecular & Chemical SC Chemistry; Physics GA UG843 UT WOS:A1996UG84300009 ER PT J AU Sharpless, KE Thomas, JB Sander, LC Wise, SA AF Sharpless, KE Thomas, JB Sander, LC Wise, SA TI Liquid chromatographic determination of carotenoids in human serum using an engineered C-30 and a C-18 stationary phase SO JOURNAL OF CHROMATOGRAPHY B-BIOMEDICAL APPLICATIONS LA English DT Article DE carotenoids ID BETA-CAROTENE; CIS-ISOMERS; HPLC SEPARATION; SELECTIVITY; RETENTION; COLUMNS; FOOD AB A C-30 stationary phase was specifically engineered for carotenoid separations, and carotenoid measurements using this column are compared with those obtained using a somewhat more conventional C-18 column. Both methods were used to contribute measurements for the certification of carotenoids in Standard Reference Material 968b, Fat-Soluble Vitamins and Cholesterol in Human Serum. Analytes were extracted from the serum into hexane. Measurements on the C-18 column were made using a gradient of acetonitrile, methanol, and ethyl acetate, which is described in detail elsewhere. Measurements on the C-30 column were made using a gradient of water, methanol, and methyl tert.-butyl ether. RP Sharpless, KE (reprint author), NIST,CHEM SCI & TECHNOL LAB,DIV ANALYT CHEM,GAITHERSBURG,MD 20899, USA. OI Sharpless, Katherine/0000-0001-6569-198X NR 24 TC 35 Z9 36 U1 0 U2 3 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 APR 12 PY 1996 VL 678 IS 2 BP 187 EP 195 DI 10.1016/0378-4347(95)00494-7 PG 9 WC Biochemical Research Methods; Chemistry, Analytical SC Biochemistry & Molecular Biology; Chemistry GA UL424 UT WOS:A1996UL42400008 PM 8738021 ER PT J AU Hapiot, P Neudeck, A Pinson, J Fulcrand, H Neta, P Rolando, C AF Hapiot, P Neudeck, A Pinson, J Fulcrand, H Neta, P Rolando, C TI Oxidation of caffeic acid and related hydroxycinnamic acids SO JOURNAL OF ELECTROANALYTICAL CHEMISTRY LA English DT Article DE electrooxidation; pulse radiolysis; caffeic acid; 4-coumaric acid; ferulic acid ID ELECTRON REDOX POTENTIALS; PULSE-RADIOLYSIS; PHENOLS; RADICALS AB Oxidation of caffeic acid (3,4-dihydroxycinnamic acid) 1H(3) has been studied by electrochemical methods and by pulse radiolysis in aqueous and organic solvents. The results have been compared with the behaviour of 4-coumaric acid 2H(2) and ferulic acid 3H(2). The first oxidative intermediates have been characterised by their UV spectra and oxidation potentials. In the case of 2H(2) and 3H(2), the initial radicals decay by a second order process indicating a radical-radical coupling mechanism. On the contrary, for caffeic acid the oxidation leads to the formation of the corresponding o-quinone through disproportionation of the initial semiquinone radical. C1 INST PROD VIGNE, LAB POLYMERES & TECH PHYSICOCHIM, F-34060 MONTPELLIER, FRANCE. NIST, DIV CHEM KINET & THERMODYNAM, GAITHERSBURG, MD 20889 USA. UNIV PARIS 06, UA CNRS 1100, ECOLE NORMALE SUPER, LAB ACTIVAT MOL, F-75231 PARIS, FRANCE. RP Hapiot, P (reprint author), UNIV PARIS 07, ELECTROCHIM MOLEC LAB, URA 438 CNRS, 2 PL JUSSIEU, F-75251 PARIS 05, FRANCE. RI PINSON, Jean/L-7028-2013; Rolando, Christian/E-8278-2011; Pinson, Jean/M-9116-2016 OI Rolando, Christian/0000-0002-3266-8860; NR 29 TC 97 Z9 98 U1 1 U2 14 PU ELSEVIER SCIENCE SA PI LAUSANNE PA PO BOX 564, 1001 LAUSANNE, SWITZERLAND SN 1572-6657 J9 J ELECTROANAL CHEM JI J. Electroanal. Chem. PD APR 12 PY 1996 VL 405 IS 1-2 BP 169 EP 176 DI 10.1016/0022-0728(95)04412-4 PG 8 WC Chemistry, Analytical; Electrochemistry SC Chemistry; Electrochemistry GA UN547 UT WOS:A1996UN54700019 ER PT J AU Schneider, WF Wallington, TJ Huie, RE AF Schneider, WF Wallington, TJ Huie, RE TI Energetics and mechanism of decomposition of CF3OH SO JOURNAL OF PHYSICAL CHEMISTRY LA English DT Article; Proceedings Paper CT International Conference on Molecular Quantum Mechanics - Methods and Applications, in Memory of Samuel Francis Boys and in Honor of Isaiah Shavitt CY SEP 03-07, 1995 CL UNIV CAMBRIDGE, CAMBRIDGE, ENGLAND HO UNIV CAMBRIDGE ID GAS-PHASE; ATMOSPHERIC CHEMISTRY; HYDROFLUOROCARBON 134A; RATE CONSTANTS; SELF-REACTION; RADICALS; KINETICS; 295-K; HYDROCHLOROFLUOROCARBONS; HFC-134A AB Ab initio calculations are used to examine the energetics of unimolecular and water-mediated decomposition of CF3OH into COF2 and HF. The calculations indicate that the barrier to unimolecular decomposition is large (42 +/- 3 kcal mol(-1)) and that the rate of this reaction is negligible at room temperature. This reaction is of no importance under ambient atmospheric conditions. The calculations also reveal a substantially lower energy pathway for decomposition that is accessible via a reaction between CF3OH and water. This pathway involves formation of a six-membered-ring transition state, with water acting as a bridge between the fluorine and hydrogen of the alcohol. The existence of this lower energy pathway is consistent with experimental evidence for the intermediacy of H2O in the decomposition of CF3OH. From the computational results the second-order rate constant for homogeneous decomposition can be estimated to lie in the range 10(-27) to 10(-22) cm(3) molecule(-1) s(-1) at 298 K and is likely too small to be atmospherically significant. The rate for heterogeneous decomposition cannot be estimated from the computational results, but the results are consistent with a prominent role for heterogeneous decomposition in the atmospheric chemistry of CF3OH. C1 NATL INST STAND & TECHNOL,DIV CHEM KINET & THERMODYNAM,GAITHERSBURG,MD 20899. RP Schneider, WF (reprint author), FORD MOTOR CO,FORD RES LAB,POB 2053,MAIL DROP 3083-SRL,DEARBORN,MI 48121, USA. NR 53 TC 35 Z9 35 U1 1 U2 3 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 SN 0022-3654 J9 J PHYS CHEM-US JI J. Phys. Chem. PD APR 11 PY 1996 VL 100 IS 15 BP 6097 EP 6103 DI 10.1021/jp952703m PG 7 WC Chemistry, Physical SC Chemistry GA UE695 UT WOS:A1996UE69500014 ER PT J AU Baker, ET Urabe, T AF Baker, ET Urabe, T TI Extensive distribution of hydrothermal plumes along the superfast spreading East Pacific Rise, 13 degrees 30'-18 degrees 40'S SO JOURNAL OF GEOPHYSICAL RESEARCH-SOLID EARTH LA English DT Article ID FUCA RIDGE; SEISMIC STRUCTURE; MIDOCEAN RIDGES; SOUTH-PACIFIC; JUAN; CREST; WATER AB A general model relating relative hydrothermal activity to the rate of plate creation requires data from the full spectrum of mid-ocean ridge spreading rates. To obtain data from a superfast spreading environment, the Japanese/U.S. Ridge Flux Project used continuous hydrographic/optical tow-yes in 1993 to map the distribution of hydrothermal plumes along the southern East Pacific Rise from 13 degrees 30' to 18 degrees 40'S. Plume incidence, the fraction of the spreading axis length overlain by a significant plume, was 0.6, including a virtually continuous vent field stretching 150 km from 17 degrees 20' to 18 degrees 40'S. Hydrothermal venting was most concentrated along portions of the ridge crest with an inflated cross-sectional area and an observable axial magma chamber reflector. This pattern agrees with previous results from the northern East Pacific Rise. Such consistency implies that hydrothermal circulation on fast spreading ridges is vigorous where the relative volume of partial melt is high and meager where melt volume is low or undetectable; ''hot rock'' alone is generally insufficient to drive significant hydrothermal circulation. Using a mean temperature anomaly of 0.014 +/- 0.010 degrees C, we estimated the hydrothermal heat flux from the study area as (1.5 +/- 1.1 x 10(7) MW)U-x, where U-x is the cross-axis flow at the ridge crest. No direct measurements of U-x are yet available. Combining the plume distribution found here with prior data from slow, intermediate, and fast spreading ridges yields a significant linear correlation between plume incidence and spreading rate that extends across the full range of plate motion. This correlation, which mirrors that for near-axis heat flux calculated by recent models, implies that magma supply rate is the principal control on the large-scale distribution of axial hydrothermal venting. C1 GEOL SURVEY JAPAN, TSUKUBA, IBARAKI 305, JAPAN. RP Baker, ET (reprint author), NOAA, PACIFIC MARINE ENVIRONM LAB, 7600 SAND POINT WAY NE, SEATTLE, WA 98115 USA. RI Wright, Dawn/A-4518-2011 OI Wright, Dawn/0000-0002-2997-7611 NR 64 TC 34 Z9 34 U1 0 U2 5 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 APR 10 PY 1996 VL 101 IS B4 BP 8685 EP 8695 DI 10.1029/95JB03746 PG 11 WC Geochemistry & Geophysics SC Geochemistry & Geophysics GA UF005 UT WOS:A1996UF00500044 ER PT J AU Wessel, P Smith, WHF AF Wessel, P Smith, WHF TI A global, self-consistent, hierarchical, high-resolution shoreline database SO JOURNAL OF GEOPHYSICAL RESEARCH-SOLID EARTH LA English DT Article AB We present a high-resolution shoreline data set amalgamated from two databases in the public domain. The data have undergone extensive processing and are free of internal inconsistencies such as erratic points and crossing segments. The shorelines are constructed entirely from hierarchically arranged closed polygons. The data can be used to simplify data searches and data selections or to study the statistical characteristics of shorelines and landmasses. The data set can be accessed both electronically over Internet and from the National Geophysical Data Center, Boulder, Colorado; it comes with access software and routines to facilitate decimation based on a standard line-reduction algorithm. C1 NOAA, GEOSCI LAB, NATL OCEAN SERV, SILVER SPRING, MD 20910 USA. RP Wessel, P (reprint author), UNIV HAWAII, SCH OCEAN & EARTH SCI & TECHNOL, DEPT GEOL & GEOPHYS, 2525 CORREA RD, HONOLULU, HI 96822 USA. RI Smith, Walter/F-5627-2010 OI Smith, Walter/0000-0002-8814-015X NR 5 TC 277 Z9 293 U1 1 U2 18 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 APR 10 PY 1996 VL 101 IS B4 BP 8741 EP 8743 DI 10.1029/96JB00104 PG 3 WC Geochemistry & Geophysics SC Geochemistry & Geophysics GA UF005 UT WOS:A1996UF00500048 ER PT J AU Kent, MS Factor, BJ Satija, S Gallagher, P Smith, GS AF Kent, MS Factor, BJ Satija, S Gallagher, P Smith, GS TI Structure of bimodal polymer brushes in a good solvent by neutron reflectivity SO MACROMOLECULES LA English DT Article ID GRAFTED CHAINS; KINETICS; FORCES AB Neutron reflection is used to examine the concentration profile of bimodal tethered layers in a good solvent. The tethered layers are Langmuir monolayers of highly asymmetric poly(dimethyl-siloxane)-polystyrene (PDMS-PS) diblock copolymers at the air surface of ethyl benzoate. The PS blocks dangle into the good solvent, while the PDMS blocks anchor the copolymers to the surface. Bimodal layers are prepared using two block copolymers which vary in the molecular weight of the dangling block. The presence of the smaller PS blocks (DOP = N-1) leads to additional stretching of the larger PS blocks (DOP = N-2) relative to their dimension in a single-component monolayer, while the dimension of the smaller PS blocks is largely unaffected by the presence of the larger blocks. For the three bimodal brushes examined; the effect of additional stretching for the larger chains is greatest (up to 30%) for N-2 congruent to 3N(1), smaller for N-2 congruent to 5N(1), and negligible for N-2 congruent to 11N(1). These trends are in agreement with self-consistent field calculations reported in the literature. In addition, it is observed that the chains with shorter dangling blocks add preferentially to an existing copolymer monolayer when the chains in the monolayer are strongly interacting. This is attributed to a greater potential barrier for the longer chains to incorporate into the monolayer due to osmotic and steric interactions. C1 NIST,GAITHERSBURG,MD 20899. LOS ALAMOS NATL LAB,LANCSE,LOS ALAMOS,NM 87545. RP Kent, MS (reprint author), SANDIA NATL LABS,DEPT 1815,ALBUQUERQUE,NM 87185, USA. NR 18 TC 37 Z9 37 U1 0 U2 10 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 SN 0024-9297 J9 MACROMOLECULES JI Macromolecules PD APR 8 PY 1996 VL 29 IS 8 BP 2843 EP 2849 DI 10.1021/ma951497d PG 7 WC Polymer Science SC Polymer Science GA UD693 UT WOS:A1996UD69300017 ER PT J AU Clarke, A Ogren, J Charlson, R AF Clarke, A Ogren, J Charlson, R TI Measurement of aerosol absorption coefficient from teflon filters using the integrating plate and integrating sphere techniques - Comment SO AEROSOL SCIENCE AND TECHNOLOGY LA English DT Article ID LIGHT-ABSORPTION; ELEMENTAL CARBON AB Campbell et al. (1995) present a study of the light transmitted by and reflected from Teflon filters, and claim that the Laser Integrating Plate Method (LIPM), a variant of the Integrating Plate Method (IPM; Lin et al., 1973), provides accurate determination of the light absorption coefficient of the particles deposited on the filters. Close examination of the paper reveals that it its an incomplete evaluation of a technique that is inappropriately compared to a questionable facsimile of an established method (IPM), and that the authors have not demonstrated that the LIPM technique provides accurate measurements of aerosol absorption coefficient. As a result of the lack of corrections for multiple scattering and absorption in the Teflon filters, data obtained with the LIPM (e.g., Maim et al., 1994) may significantly overestimate the true aerosol absorption coefficient. C1 NOAA,CLIMATE MONITORING & DIAGNOST LAB,BOULDER,CO 80303. UNIV WASHINGTON,DEPT ATMOSPHER SCI,SEATTLE,WA 98195. RP Clarke, A (reprint author), UNIV HAWAII,DEPT OCEANOG,1000 POPE RD,HONOLULU,HI 96822, USA. RI Ogren, John/M-8255-2015 OI Ogren, John/0000-0002-7895-9583 NR 11 TC 6 Z9 6 U1 0 U2 1 PU ELSEVIER SCIENCE INC PI NEW YORK PA 655 AVENUE OF THE AMERICAS, NEW YORK, NY 10010 SN 0278-6826 J9 AEROSOL SCI TECH JI Aerosol Sci. Technol. PD APR PY 1996 VL 24 IS 3 BP 221 EP 224 DI 10.1080/02786829608965366 PG 4 WC Engineering, Chemical; Engineering, Mechanical; Environmental Sciences; Meteorology & Atmospheric Sciences SC Engineering; Environmental Sciences & Ecology; Meteorology & Atmospheric Sciences GA UD617 UT WOS:A1996UD61700010 ER PT J AU Ramos, BL Choquette, SJ Fell, NF AF Ramos, BL Choquette, SJ Fell, NF TI Embossable grating couplers for planar waveguide optical sensors SO ANALYTICAL CHEMISTRY LA English DT Article ID WAVE-GUIDES; THIN-FILMS; IMMUNOSENSOR AB Planar optical waveguides are an attractive tool for use in analytical chemistry and spectroscopy. Although similar to fiber optics, planar waveguides have been slow to be commercially accepted due to the difficulty of coupling light into the guide. Generally, prism coupling is the method of choice in the laboratory, as efficiencies approaching 80% can be reached. However, prisms are impractical for routine use for several reasons: expensive positioning equipment is required, coupled power is sensitive to environmental fluctuations, and prism coupling prohibits the fabrication of a truly planar device. The use of thin gratings on the surface of the waveguide allows for a two-dimensional structure to be maintained, while providing enough efficiency to be useful as a sensor. Our research efforts focus on developing a technique to make inexpensive, reproducible gratings that are easy to fabricate. By chemically modifying the surface of a commercial grating with a suitable release agent, it is possible to emboss replica gratings onto a variety of waveguide types. The fabrication of embossed gratings will be described, and their performance on glass, ion-diffused, polymer, and semiconductor waveguides will be presented. C1 NATL INST STAND & TECHNOL,DIV ANALYT CHEM,GAITHERSBURG,MD 20899. USA,RES LAB,IGNIT & COMBUST BRANCH,ABERDEEN PROVING GROUND,MD 21005. NR 24 TC 19 Z9 20 U1 0 U2 5 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 SN 0003-2700 J9 ANAL CHEM JI Anal. Chem. PD APR 1 PY 1996 VL 68 IS 7 BP 1245 EP 1249 DI 10.1021/ac950579x PG 5 WC Chemistry, Analytical SC Chemistry GA UC182 UT WOS:A1996UC18200033 PM 21619155 ER PT J AU Park, LK Moran, P Dightman, DA AF Park, LK Moran, P Dightman, DA TI A chinook salmon PCR-RFLP marker in the p53 locus SO ANIMAL GENETICS LA English DT Article RP Park, LK (reprint author), NOAA,NATL MARINE FISHERIES SERV,NW FISHERIES SCI CTR,COASTAL ZONE & ESTUARINE STUDIES DIV,SEATTLE,WA 98112, USA. NR 3 TC 10 Z9 10 U1 0 U2 0 PU BLACKWELL SCIENCE LTD PI OXFORD PA OSNEY MEAD, OXFORD, OXON, ENGLAND OX2 0EL SN 0268-9146 J9 ANIM GENET JI Anim. Genet. PD APR PY 1996 VL 27 IS 2 BP 127 EP 128 PG 2 WC Agriculture, Dairy & Animal Science; Genetics & Heredity SC Agriculture; Genetics & Heredity GA UP470 UT WOS:A1996UP47000020 PM 8856913 ER PT J AU Wu, CC Wu, ST Dryer, M AF Wu, CC Wu, ST Dryer, M TI Generation and evolution of interplanetary slow shocks SO ANNALES GEOPHYSICAE-ATMOSPHERES HYDROSPHERES AND SPACE SCIENCES LA English DT Article ID SOLAR-WIND; INTERACTION REGIONS; WAVES; AU; DISTURBANCES; 1-AU; SUN AB It is well known that most MHD shocks observed within 1 AU are MHD fast shocks. Only a very limited number of MHD slow shocks are observed within 1 AU. In order to understand why there are only a few MHD slow shocks observed within 1 AU, we use a one-dimensional, time-dependent MHD code with an adaptive grid to study the generation and evolution of interplanetary slow shocks (ISS) in the solar wind. Results show that a negative, nearly square-wave perturbation will generate a pair of slow shocks (a forward and a reverse slow shock). In addition, the forward and the reverse slow shocks can pass through each other without destroying their characteristics, but the propagating speeds for both shocks are decreased. A positive, square-wave perturbation will generate both slow and fast shocks. When a forward slow shock (FSS) propagates behind a forward fast shock (FFS), the former experiences a decreasing Mach number. In addition, the FSS always disappears within a distance of 150R. (where R. is one solar radius) from the Sun when there is a forward fast shock (with Mach number greater than or equal to 1.7) propagating in front of the FSS. In all tests that we have performed, we have not discovered that the FSS (or reverse slow shock) evolves into a FFS (or reverse fast shock). Thus, we do not confirm the FSS-FFS evolution as suggested by Whang (1987). C1 UNIV COLORADO,COOPERAT INST RES ENVIRONM SCI,BOULDER,CO 80309. NOAA,SPACE ENVIRONM CTR,BOULDER,CO 80303. NATL CENT UNIV,INST SPACE SCI,CHUNGLI 32054,TAIWAN. UNIV ALABAMA,DEPT MECH ENGN,HUNTSVILLE,AL 35899. UNIV ALABAMA,CTR SPACE PLASMA & AERON RES,HUNTSVILLE,AL 35899. NR 40 TC 8 Z9 8 U1 0 U2 0 PU SPRINGER VERLAG PI NEW YORK PA 175 FIFTH AVE, NEW YORK, NY 10010 SN 0992-7689 J9 ANN GEOPHYS JI Ann. Geophys.-Atmos. Hydrospheres Space Sci. PD APR PY 1996 VL 14 IS 4 BP 375 EP 382 DI 10.1007/s00585-996-0375-1 PG 8 WC Astronomy & Astrophysics; Geosciences, Multidisciplinary; Meteorology & Atmospheric Sciences SC Astronomy & Astrophysics; Geology; Meteorology & Atmospheric Sciences GA UF501 UT WOS:A1996UF50100002 ER PT J AU Wu, CC Dryer, M Wu, ST AF Wu, CC Dryer, M Wu, ST TI Three-dimensional MHD simulation of interplanetary magnetic field changes at 1 AU as a consequence of simulated solar flares SO ANNALES GEOPHYSICAE-ATMOSPHERES HYDROSPHERES AND SPACE SCIENCES LA English DT Article ID EULERIAN FICE SCHEME; GEOMAGNETIC STORMS; CURRENT SHEET; WIND; DISTURBANCES; SUN; MAGNETOSPHERE; SCINTILLATION; HELIOSPHERE; PARAMETERS AB A fully three-dimensional (3D), time-dependent, MHD interplanetary global model (3D IGM) has been used, for the first time, to study the relationship between different forms of solar activity and transient variations of the north-south component, B-z, of the interplanetary magnetic field (IMF) at 1 AU. One form of solar activity, the hare, is simulated by using a pressure pulse at different locations near the solar surface and observing the simulated IMF evolution of B-theta (= - B-z) at 1 AU. Results show that, for a given pressure pulse, the orientation of the corresponding transient variation of B-z has a strong relationship to the location of the pressure pulse and the initial conditions of the IMF. Two initial IMF conditions are considered: a unipolar Archimedean spiral with outward polarity and a flat heliospheric current sheet (HCS) with outward polarity in the northern hemisphere and which gradually reverses polarity in the solar equatorial plane to inward polarity in the southern heliospheric hemisphere. The wave guide effect of the HCS is also demonstrated. C1 NOAA,SPACE ENVIRONM CTR,BOULDER,CO 80303. NATL CENT UNIV,INST SPACE SCI,CHUNGLI 32054,TAIWAN. UNIV ALABAMA,CTR SPACE PLASMA & AERON RES,HUNTSVILLE,AL 35899. UNIV ALABAMA,DEPT MECH ENGN,HUNTSVILLE,AL 35899. NR 48 TC 27 Z9 27 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 APR PY 1996 VL 14 IS 4 BP 383 EP 399 DI 10.1007/s00585-996-0383-1 PG 17 WC Astronomy & Astrophysics; Geosciences, Multidisciplinary; Meteorology & Atmospheric Sciences SC Astronomy & Astrophysics; Geology; Meteorology & Atmospheric Sciences GA UF501 UT WOS:A1996UF50100003 ER PT J AU Jupp, BP Durako, MJ Kenworthy, WJ Thayer, GW Schillak, L AF Jupp, BP Durako, MJ Kenworthy, WJ Thayer, GW Schillak, L TI Distribution, abundance, and species composition of seagrasses at several sites in Oman SO AQUATIC BOTANY LA English DT Article DE seagrasses; Oman; Arabian Sea upwelling; grazing; survival strategies ID WESTERN ARABIAN GULF; COAST; ECOLOGY AB Distribution, abundance, and biomass data for seagrass communities at several locations on the coast of Oman are presented. The main study site was on the western side of Masirah Island on the Arabian Sea coast of Oman. This area is an important feeding ground for the green turtle, Chelonia mydas L., and it is affected by upwelling of low temperature waters during the summer monsoon. The depth distributions of Halodule uninervis (Forssk.) Aschers, and Halophila ovalis (R. Brown) Hook, f., the two most abundant seagrasses at this site, overlapped but were inversely related. Halodule dominated the intertidal zone and Halophila was more predominant in the deep subtidal, although total biomass of the two seagrasses were similar in this depth zone. At all depths, biomass of Halophila was about equally distributed between leaves and roots and rhizomes. Leaf biomass of Halodule was only 7-20% of the total biomass and the highest below-ground biomass occurred in the intertidal zone. Biomass of these species here and at other sites and of Thalassodendron ciliatum (Forssk.) den Hartog at this site was generally lower than comparative data in the Gulf and the Red Sea. Small patches of Syringodium isoetifolium (Aschers.) Dandy were also observed in Umm ar Rasas Bight making a total of four species recorded to occur in Oman. The reduced growth of seagrasses at Masirah Island seems to be due to stresses associated with the summer monsoon and grazing pressure, Survival of these populations is discussed in terms of seasonal growth and flowering. C1 FLORIDA MARINE RES INST,ST PETERSBURG,FL 33701. NATL MARINE FISHERIES SERV,BEAUFORT LAB,NOAA,BEAUFORT,NC 28516. WORLD WIDE FUND NAT,D-60591 FRANKFURT,GERMANY. RP Jupp, BP (reprint author), SULTAN QABOOS UNIV,DEPT BIOL,POB 36,AL KHOD 123,MUSCAT,OMAN. NR 38 TC 21 Z9 22 U1 3 U2 8 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0304-3770 J9 AQUAT BOT JI Aquat. Bot. PD APR PY 1996 VL 53 IS 3-4 BP 199 EP 213 DI 10.1016/0304-3770(96)01023-6 PG 15 WC Plant Sciences; Marine & Freshwater Biology SC Plant Sciences; Marine & Freshwater Biology GA UY643 UT WOS:A1996UY64300006 ER PT J AU Vacca, WD Garmany, CD Shull, JM AF Vacca, WD Garmany, CD Shull, JM TI The Lyman-continuum fluxes and stellar parameters of O and early B-TYPE stars SO ASTROPHYSICAL JOURNAL LA English DT Review DE stars, atmospheres; stars, early-type; stars, fundamental parameters; ultraviolet, stars ID INCLUDING SPHERICAL EXTENSION; LTE MODEL ATMOSPHERES; ABSOLUTE-MAGNITUDE CALIBRATION; LARGE MAGELLANIC CLOUD; UPPER MAIN-SEQUENCE; MASSIVE STARS; HOT STARS; MILKY-WAY; HE-II; QUANTITATIVE SPECTROSCOPY AB Using the results of the most recent stellar atmosphere models applied to a sample of hot stars, we construct calibrations of effective temperature (T-eff), and gravity (log g) with a spectral type and luminosity class for Galactic O-type and early B-type stars. From the model results we also derive an empirical relation between the bolometric correction and T-eff and log g. Using a sample of stars with known distances located in OB associations in the Galaxy and the Large Magellanic Cloud, we derive a new calibration of M(V) with spectral class. With these new calibrations and the stellar atmosphere models of Kurucz we calculate the physical parameters and ionizing photon luminosities in the H-0 and He-0 continua for O and early B-type stars. We find substantial differences between our values of the Lyman-continuum luminosity and those reported in the literature. We also discuss the systematic discrepancy between O-type stellar masses derived from spectroscopic models and those derived from evolutionary tracks. Most likely, the cause of this ''mass discrepancy'' lies primarily in the atmospheric models, which are plane parallel and hydrostatic and therefore do not account for an extended atmosphere and the velocity fields in a stellar wind. Finally, we present a new computation of the Lyman-continuum luminosity from 429 known O stars located within 2.5 kpc of the Sun. We find the total ionizing luminosity from this population (Q(0)(Tot) = 7.0 x 10(51) photons s(-1)) to be 47% larger than that determined using the Lyman continuum values tabulated by Panagia. C1 UNIV CALIF BERKELEY,DEPT ASTRON,BERKELEY,CA 94720. UNIV COLORADO,JOINT INST LAB ASTROPHYS,BOULDER,CO 80309. NIST,BOULDER,CO 80309. NR 103 TC 639 Z9 642 U1 0 U2 0 PU UNIV CHICAGO PRESS PI CHICAGO PA 5720 S WOODLAWN AVE, CHICAGO, IL 60637 SN 0004-637X J9 ASTROPHYS J JI Astrophys. J. PD APR 1 PY 1996 VL 460 IS 2 BP 914 EP 931 DI 10.1086/177020 PN 1 PG 18 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA UB530 UT WOS:A1996UB53000030 ER PT J AU Zhang, YQ Arya, SP Snyder, WH AF Zhang, YQ Arya, SP Snyder, WH TI A comparison of numerical and physical modeling of stable atmospheric flow and dispersion around a cubical building SO ATMOSPHERIC ENVIRONMENT LA English DT Article DE numerical simulation; kappa-epsilon model; cavity length; building wake; turbulent kinetic energy; physical modeling; building downwash; atmospheric dispersion ID BOUNDARY-LAYER AB Our objective is to examine the potential application of a k-epsilon model (TEMPEST) for simulating flow-field and dispersion patterns around a cubical building under stably stratified approach Row. The results of these numerical simulations are compared with available measurements from towing-tank experiments on dispersion around a cube. The modeled and measured Row and concentration patterns are compared in order to ascertain the effects of changes in the stratification, which is characterized by the Froude number Fr = U/NH (where U is the approach-Row wind speed, N is the Brunt-Vaisala frequency, and H is the building height-large Fr implies weak stability and vice versa). Both the model and experimental results suggest that the Row structure is independent of stratification when Fr greater than or equal to 6. The model predicts a moderate increase in the length L(c) of the lee-side ''cavity'' (recirculation region) as the Froude number is decreased from 6 to 3 (moderate stratification), then a sharp decrease in L(c) as Fr is further decreased to 1 (very strong stratification). The measured results, however, show L(c) to be constant as Fr is decreased to 3, then a sharp decrease as Fr is further decreased to 1. The agreement between the measured and model-predicted concentration field when a source was located within the recirculating cavity behind the building was fair under weakly stratified conditions (Fr greater than or equal to 3), but poor under strongly stratified conditions (Fr = 1). These simulations show that, in strongly stratified conditions, mean advection plays a more important role than does turbulent diffusion because the turbulence is very weak in such flows. And because the Froude number will rarely be less than about 3 in the nighttime stable boundary layer, these results suggest that stratification will rarely be a significant factor influencing the flow structure in the near-vicinity of a building. C1 N CAROLINA STATE UNIV, DEPT MARINE EARTH & ATMOSPHER SCI, RALEIGH, NC 27695 USA. NOAA, AIR RESOURCES LAB, DIV ATMOSPHER SCI MODELING, RES TRIANGLE PK, NC 27711 USA. RP Zhang, YQ (reprint author), LOCKHEED MARTIN US EPA SCI VISUALIZAT CTR, POB 14365, MS24-ERC1, RES TRIANGLE PK, NC 27709 USA. NR 18 TC 51 Z9 52 U1 0 U2 4 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLAND SN 1352-2310 J9 ATMOS ENVIRON JI Atmos. Environ. PD APR PY 1996 VL 30 IS 8 BP 1327 EP 1345 DI 10.1016/1352-2310(95)00326-6 PG 19 WC Environmental Sciences; Meteorology & Atmospheric Sciences SC Environmental Sciences & Ecology; Meteorology & Atmospheric Sciences GA UA044 UT WOS:A1996UA04400013 ER PT J AU Butler, JH AF Butler, JH TI Scientific uncertainties in the budget of atmospheric methyl bromide SO ATMOSPHERIC ENVIRONMENT LA English DT Article RP Butler, JH (reprint author), NOAA,CLIMATE MONITORING & DIAGNOST LAB,BOULDER,CO 80303, USA. NR 0 TC 8 Z9 8 U1 0 U2 2 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 APR PY 1996 VL 30 IS 7 BP R1 EP R3 PG 3 WC Environmental Sciences; Meteorology & Atmospheric Sciences SC Environmental Sciences & Ecology; Meteorology & Atmospheric Sciences GA UA047 UT WOS:A1996UA04700019 ER PT J AU Juhasz, A Ravi, S OConnell, CD AF Juhasz, A Ravi, S OConnell, CD TI Sensitivity of tyrosinase mRNA detection by RT-PCR: rTth DNA polymerase vs MMLV-RT and AmpliTaq(R) polymerase SO BIOTECHNIQUES LA English DT Article ID AMPLIFICATION RP Juhasz, A (reprint author), NATL INST STAND & TECHNOL,CSTL,DIV BIOTECHNOL,GAITHERSBURG,MD 20899, USA. NR 8 TC 7 Z9 7 U1 0 U2 1 PU EATON PUBLISHING CO PI NATICK PA 154 E. CENTRAL ST, NATICK, MA 01760 SN 0736-6205 J9 BIOTECHNIQUES JI Biotechniques PD APR PY 1996 VL 20 IS 4 BP 592 EP & PG 5 WC Biochemical Research Methods; Biochemistry & Molecular Biology SC Biochemistry & Molecular Biology GA UD717 UT WOS:A1996UD71700011 PM 8800676 ER PT J AU Long, CS Miller, AJ Lee, HT Wild, JD Przywarty, RC Hufford, D AF Long, CS Miller, AJ Lee, HT Wild, JD Przywarty, RC Hufford, D TI Ultraviolet index forecasts issued by the National Weather Service SO BULLETIN OF THE AMERICAN METEOROLOGICAL SOCIETY LA English DT Article ID RADIATION; OZONE; UV AB The National Weather Service (NWS), in collaboration with the Environmental Protection Agency (EPA), now issues an Ultraviolet (UV) index forecast. The UV index (UVI) is a mechanism by which the American public is forewarned of the next day's noontime intensity of UV radiation at locations within the United States. The EPA's role in this effort is to alert the public of the dangerous health effects of overexposure to, and the accumulative effects of, UV radiation. The EPA also provides ground-level monitoring data for use in ongoing verification of the UVI. The NWS estimates the UVI using existing atmospheric measurements, forecasts, and an advanced radiative transfer model. This paper discusses the justification for a forecasted index, the nature of UV radiation, the methodology of producing the UVI, and results from verifying the UVI. Since the UVI is an evolving product, a short discussion of necessary improvements and/or refinements is included at the end of this article. C1 RES & DATA SYST CORP,GREENBELT,MD. NOAA,NWS,METEOROL OFF,WASHINGTON,DC. US EPA,OAR,OFF ATMOSPHER PROGRAMS,WASHINGTON,DC. RP Long, CS (reprint author), NOAA,NWS,NATL CTR ENVIRONM PREDICT,CLIMATE PREDICT CTR,STRATOSPHER ANAL GRP,W-NP53,WASHINGTON,DC 20233, USA. NR 26 TC 78 Z9 90 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 APR PY 1996 VL 77 IS 4 BP 729 EP 748 DI 10.1175/1520-0477(1996)077<0729:UIFIBT>2.0.CO;2 PG 20 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA UG177 UT WOS:A1996UG17700006 ER PT J AU Wainright, SC Fuller, CM Michener, RH Richards, RA AF Wainright, SC Fuller, CM Michener, RH Richards, RA TI Spatial variation of trophic position and growth rate of juvenile striped bass (Morone saxatilis) in the Delaware River SO CANADIAN JOURNAL OF FISHERIES AND AQUATIC SCIENCES LA English DT Article ID WEAKFISH CYNOSCION-REGALIS; STABLE ISOTOPIC COMPOSITIONS; FOOD WEB; LARVAL WEAKFISH; GEORGES-BANK; ORGANIC-MATTER; PREY ABUNDANCE; BROWN SHRIMP; NITROGEN; CARBON AB The relative recent growth rate (as marginal scale circulus width) of juvenile striped bass (Morone saxatilis) was faster in the oligohaline region of the Delaware River (near the turbidity maximum) than further upstream. Stable isotope analyses (delta(13)C and delta(15)N) of the same fish suggested that this difference in growth rate is associated with a change in trophic position. Although salinity was low (0-5 ppt), the delta(13)C values of fish from the oligohaline region (-21.3 to -23 parts per thousand) suggest that a significant part of their diet may be derived from marine-like sources. All delta(15)N values for juvenile striped bass were high relative to previously published delta(15)N values for freshwater and marine fish and are suggestive of inputs of sewage-derived nitrogen. Fish from the oligohaline region (delta(15)N values of 16-20.6 parts per thousand) may occupy a lower trophic level than fish collected further upstream (delta(15)N values of 22.4-26.4 parts per thousand) based on the difference between the delta(15)N of fish and literature values for particulate organic matter collected in the same area and season. To the extent that trophic position reflects habitat quality, habitat quality for juvenile striped bass varies regionally within the Delaware River estuary. C1 BOSTON UNIV, DEPT BIOL, STABLE ISOTOPE LAB, BOSTON, MA 02215 USA. NOAA, NE FISHERIES SCI CTR, NATL MARINE FISHERIES SERV, WOODS HOLE, MA 02543 USA. RP RUTGERS STATE UNIV, INST MARINE & COASTAL SCI, COOK CAMPUS, NEW BRUNSWICK, NJ 08903 USA. RI Fuller, Cathy/B-4046-2011 NR 54 TC 39 Z9 39 U1 2 U2 10 PU CANADIAN SCIENCE PUBLISHING, NRC RESEARCH PRESS PI OTTAWA PA 65 AURIGA DR, SUITE 203, OTTAWA, ON K2E 7W6, CANADA SN 0706-652X EI 1205-7533 J9 CAN J FISH AQUAT SCI JI Can. J. Fish. Aquat. Sci. PD APR PY 1996 VL 53 IS 4 BP 685 EP 692 DI 10.1139/cjfas-53-4-685 PG 8 WC Fisheries; Marine & Freshwater Biology SC Fisheries; Marine & Freshwater Biology GA VD063 UT WOS:A1996VD06300001 ER PT J AU Volgenau, L Kraus, SD Lien, J AF Volgenau, L Kraus, SD Lien, J TI The impact of entanglements on two substocks of the western North Atlantic humpback whale, Megaptera novaeangliae (vol 73, pg 1689, 1995) SO CANADIAN JOURNAL OF ZOOLOGY-REVUE CANADIENNE DE ZOOLOGIE LA English DT Correction, Addition C1 NOAA,NATL OCEAN SERV,OFF OCEAN RESOURCES CONSERVAT & ASSESSMENT,STRATEG ENVIRONM ASSESMENTS DIV,SILVER SPRING,MD 20910. NEW ENGLAND AQUARIUM,BOSTON,MA 02110. MEM UNIV NEWFOUNDLAND,WHALE RES GRP,CTR OCEAN SCI,ST JOHNS,NF A1C 5S7,CANADA. NR 1 TC 0 Z9 0 U1 1 U2 3 PU NATL RESEARCH COUNCIL CANADA PI OTTAWA PA RESEARCH JOURNALS, MONTREAL RD, OTTAWA ON K1A 0R6, CANADA SN 0008-4301 J9 CAN J ZOOL JI Can. J. Zool.-Rev. Can. Zool. PD APR PY 1996 VL 74 IS 4 BP 766 EP 766 DI 10.1139/z96-088 PG 1 WC Zoology SC Zoology GA UH863 UT WOS:A1996UH86300022 ER PT J AU Jones, MC Nassimbene, RD Wolfe, JD Frederick, NV AF Jones, MC Nassimbene, RD Wolfe, JD Frederick, NV TI Mixing and dispersion measurements on packed bed flows using a fiberoptic probe array SO CHEMICAL ENGINEERING SCIENCE LA English DT Article ID CHROMATOGRAPHY AB Scale-up of packed bed processes, particularly those involving chromatographic separations, is made difficult by a seemingly inevitable increase in dispersion due to packing nonuniformity. To provide a suitable characterization, we measured the spatial distribution of dispersion and mixing in packed beds of uniform Impervious spherical glass particles by a tracer impulse technique. The key feature in our work is the use of a fiberoptic array at the exit plane to obtain a time-resolved spatially-distributed response. All experiments wire in the creeping flow regime. We used a fluorescent dye with laser excitation through the fiber terminations in the bed. The fluoresced radiation was collected through the same fibers. We analysed the data by the use of indices of the extent of micromixing based on Danckwerts's degree of segregation. This requires the computation of moments of the responses of the individual probes and their average. A simple model gives expressions for the indices in terms of the Peclet number and is shown to provide a useful limiting case. The computed indices are also shown to be very sensitive to adsorption of dye on the surface of the glass spheres. However, for some of the experiments with the largest spheres made of Pyrex glass, adsorption appears to have played an insignificant role. This technique successfully separates overall bed dispersion into two parts that due to large-scale transverse variation of the flow residence time, and that due to mixing on the microscale. C1 NATL INST STAND & TECHNOL,CHEM SCI & TECHNOL LAB,BOULDER,CO 80303. NR 13 TC 5 Z9 5 U1 0 U2 0 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD, ENGLAND OX5 1GB SN 0009-2509 J9 CHEM ENG SCI JI Chem. Eng. Sci. PD APR PY 1996 VL 51 IS 7 BP 1009 EP 1021 DI 10.1016/S0009-2509(96)80001-7 PG 13 WC Engineering, Chemical SC Engineering GA UA399 UT WOS:A1996UA39900001 ER PT J AU Slingo, JM Sperber, KR Boyle, JS Ceron, JP Dix, M Dugas, B Ebisuzaki, W Fyfe, J Gregory, D Gueremy, JF Hack, J Harzallah, A Inness, P Kitoh, A Lau, WKM McAvaney, B Madden, R Matthews, A Palmer, TN Park, CK Randall, D Renno, N AF Slingo, JM Sperber, KR Boyle, JS Ceron, JP Dix, M Dugas, B Ebisuzaki, W Fyfe, J Gregory, D Gueremy, JF Hack, J Harzallah, A Inness, P Kitoh, A Lau, WKM McAvaney, B Madden, R Matthews, A Palmer, TN Park, CK Randall, D Renno, N TI Intraseasonal oscillations in 15 atmospheric general circulation models: Results from an AMIP diagnostic subproject SO CLIMATE DYNAMICS LA English DT Article ID OUTGOING LONGWAVE RADIATION; 30-60 DAY OSCILLATION; WESTERN PACIFIC; ANGULAR-MOMENTUM; NORTHERN WINTER; CONVECTION; ANOMALIES; CLUSTERS; TROPICS; OCEAN AB The ability of 15 atmospheric general circulation models (AGCM) to simulate the tropical intraseasonal oscillation has been studied as part of the Atmospheric Model Intercomparison Project (AMIP). Time series of the daily upper tropospheric velocity poential and zonal wind, averaged over the equatorial belt, were provided from each AGCM simulation. These data were analyzed using a variety of techniques such as time filtering and space-time spectral analysis to identify eastward and westward moving waves. The results have been compared with an identical assessment of the European Centre for Medium-range Weather Forecasts (ECMWF) analyses for the period 1982-1991. The models display a wide range of skill in simulating the intraseasonal oscillation. Most models show evidence of an eastward propagating anomaly in the velocity potential field, although in some models there is a greater tendency for a standing oscillation, and in one or two the field is rather chaotic with no preferred direction of propagation. Where a model has a clear eastward propagating signal, typical periodicities seem quite reasonable although there is a tendency for the models to simulate shorter periods than in the ECMWF analyses, where it is near 50 days. The results of the space-time spectral analysis have shown that no model has captured the dominance of the intraseasonal oscillation found in the analyses. Several models have peaks at intraseasonal time scales, but nearly all have relatively more power at higher frequencies (<30 days) than the analyses. Most models underestimate the strength of the intraseasonal variability. The observed intraseasonal oscillation shows a marked seasonality in its occurrence with greatest activity during northern winter and spring. Most models failed to capture this seasonality. The interannual variability in the activity of the intraseasonal oscillation has also been assessed, although the AMIP decade is too short to provide any conclusive results. There is a suggestion that, the observed oscillation was suppressed during the strong El Nino of 1982/83, and this relationship has also been reproduced by some models. The relationship between a model's intraseasonal activity, its seasonal cycle and characteristics of its basic climate has been examined. It is clear that those models with weak intraseasonal activity tend also to have a weak seasonal cycle. It is becoming increasingly evident that an accurate description of the basic climate may be a prerequisite for producing a realistic intraseasonal. In particular, models with the most realistic intraseasonal oscillations appear to have precipitation distributions which are better correlated with warm sea surface temperatures. These models predominantly employ convective parameterizations which are closed on buoyancy rather than moisture convergence. C1 LAWRENCE LIVERMORE NATL LAB,PROGRAM CLIMATE MODEL DIAGNOSIS & INTERCOMPARISON,LIVERMORE,CA 94551. METEO FRANCE,ECOLE NATL METEOROL,F-31057 TOULOUSE,FRANCE. CSIRO,DIV ATMOSPHER RES,MORDIALLOC,VIC 3195,AUSTRALIA. NOAA,NMC,CAMP SPRINGS,MD 20746. UNIV VICTORIA,CANADIAN CLIMATE CTR,VICTORIA,BC V8W 2Y2,CANADA. UK METEOROL OFF,HADLEY CTR CLIMATE PREDICT & RES,BRACKNELL RG12 2SY,BERKS,ENGLAND. NATL CTR ATMOSPHER RES,BOULDER,CO 80307. ECOLE NORMALE SUPER,CNRS,METEOROL DYNAM LAB,F-75231 PARIS 05,FRANCE. METEOROL RES INST,TSUKUBA,IBARAKI 305,JAPAN. BUR METEOROL RES CTR,MELBOURNE,VIC 3001,AUSTRALIA. EUROPEAN CTR MEDIUM RANGE WEATHER FORECASTS,READING RG2 9AX,BERKS,ENGLAND. NASA,GODDARD SPACE FLIGHT CTR,DATA ASSIMILAT OFF,GREENBELT,MD 20771. COLORADO STATE UNIV,DEPT ATMOSPHER SCI,FT COLLINS,CO 80523. CALTECH,PASADENA,CA 91125. RP Slingo, JM (reprint author), UNIV READING,DEPT METEOROL,2 EARLEY GATE,READING RG6 6AU,BERKS,ENGLAND. RI Matthews, Adrian/A-6444-2011; Dix, Martin/A-2334-2012; Sperber, Kenneth/H-2333-2012; Randall, David/E-6113-2011; Lau, William /E-1510-2012 OI Matthews, Adrian/0000-0003-0492-1168; Dix, Martin/0000-0002-7534-0654; Randall, David/0000-0001-6935-4112; Lau, William /0000-0002-3587-3691 NR 45 TC 392 Z9 424 U1 3 U2 15 PU SPRINGER VERLAG PI NEW YORK PA 175 FIFTH AVE, NEW YORK, NY 10010 SN 0930-7575 J9 CLIM DYNAM JI Clim. Dyn. PD APR PY 1996 VL 12 IS 5 BP 325 EP 357 DI 10.1007/BF00231106 PG 33 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA UF608 UT WOS:A1996UF60800003 ER PT J AU Linteris, GT Truett, L AF Linteris, GT Truett, L TI Inhibition of premixed methane-air flames by fluoromethanes SO COMBUSTION AND FLAME LA English DT Article ID CF3BR AB This paper presents the first calculations and measurements of the burning velocity of premixed hydrocarbon flames inhibited by the three one-carbon fluorinated species CH2F2, CF3H, and CF4. The chemistry of these agents is expected to be similar to that of some agents that may be used as replacements for CF3Br, so that studying their behavior in methane flames provides an important first step towards understanding the suppression mechanism of hydrocarbon fires by fluorinated compounds. The burning velocity of premixed methane-air flames stabilized on a Mache-Hebra nozzle burner is determined using the total area method from a schlieren image of the flame. The inhibitors are tested over a range of concentration and fuel-air equivalence ratio, phi. The measured burning velocity reduction caused by addition of the inhibitor is compared with that predicted by numerical solution of the species and energy conservation equations employing a detailed chemical kinetic mechanism recently developed at the National Institute of Standards and Technology (NIST). Even in this first test of the kinetic mechanism on inhibited hydrocarbon flames, the numerically predicted burning velocity reductions for methane-air flames with val,les of phi of 0.9, 1.0, and 1.1 and inhibitor mole fractions in the unburned gases up to 0.08, are in excellent agreement for CH2F2 and CF4 and within 35% for CF3H. The numerical results indicate that the agents CF3H and CH2F2 are totally consumed in the flame and the burning velocity is reduced primarily by a reduction in the H-atom concentration through reactions leading to HF formation. In contrast, only about 10% of the CF4 is consumed in the main reaction zone and it reduces the burning velocity primarily by lowering the final temperature of the burned gases. C1 WL,FIVS,DAYTON,OH 45433. RP Linteris, GT (reprint author), NATL INST STAND & TECHNOL,BLDG & FIRE RES LAB,FIRE SCI DIV,GAITHERSBURG,MD 20899, USA. NR 44 TC 77 Z9 81 U1 0 U2 3 PU ELSEVIER SCIENCE INC PI NEW YORK PA 655 AVENUE OF THE AMERICAS, NEW YORK, NY 10010 SN 0010-2180 J9 COMBUST FLAME JI Combust. Flame PD APR PY 1996 VL 105 IS 1-2 BP 15 EP 27 DI 10.1016/0010-2180(95)00152-2 PG 13 WC Thermodynamics; Energy & Fuels; Engineering, Multidisciplinary; Engineering, Chemical; Engineering, Mechanical SC Thermodynamics; Energy & Fuels; Engineering GA UC913 UT WOS:A1996UC91300002 ER PT J AU Taylor, BL Dizon, AE AF Taylor, BL Dizon, AE TI The need to estimate power to link genetics and demography for conservation SO CONSERVATION BIOLOGY LA English DT Article ID STATISTICAL POWER RP Taylor, BL (reprint author), SW FISHERIES SCI CTR, POB 271, LA JOLLA, CA 92038 USA. NR 11 TC 38 Z9 41 U1 0 U2 2 PU WILEY-BLACKWELL PI MALDEN PA COMMERCE PLACE, 350 MAIN ST, MALDEN 02148, MA USA SN 0888-8892 J9 CONSERV BIOL JI Conserv. Biol. PD APR PY 1996 VL 10 IS 2 BP 661 EP 664 DI 10.1046/j.1523-1739.1996.10020661.x PG 4 WC Biodiversity Conservation; Ecology; Environmental Sciences SC Biodiversity & Conservation; Environmental Sciences & Ecology GA UK801 UT WOS:A1996UK80100049 ER PT J AU Eakin, CM AF Eakin, CM TI Where have all the carbonates gone? A model comparison of calcium carbonate budgets before and after the 1982-1983 El Nino at Uva Island in the eastern Pacific SO CORAL REEFS LA English DT Article ID CORAL REEFS; COMMUNITY STRUCTURE; FRENCH-POLYNESIA; COAST; MORTALITY; MOOREA; PANAMA; SEA AB El Nino related coral mortality and a subsequent increase in crustose coralline algae and sea urchins have resulted in profound changes to the coral reef ecosystem at Uva Island, Panama (Pacific coast). New data and a model are presented that analyze the CaCO3 budget of the reef. The model accounts for production by corals and coralline algae, erosion by Diadema, infauna, fish and other motile organisms, and the retention of sediments as a function of size. The 2.5 ha reef is currently eroding at an average rate of 4,800 kg/y or -0.19 kg/m(2)/y but there is tremendous variation among reef zones. While deposition in other zones range from +0.1 to 0.4 kg/m(2)/y, erosion of the seaward reef base averages about -3.65 kg/m(2)/y. The damselfish/algal lawn symbiosis protects portions of the reef framework, reducing net losses there by 2,000 kg/y (up to 0.33 kg/m(2)/y). Before the 1982-1983 El Nino, the overall reef was depositional. At that time, estimated production exceeded erosion in most zones, resulting in a net deposition of approximately 8,600 kg/y or 0.34 kg/m(2)/y. RP Eakin, CM (reprint author), NOAA, OFF GLOBAL PROGRAMS, 1000 WAYNE AVE, SUITE 1210, SILVER SPRING, MD 20910 USA. RI Eakin, C. Mark/F-5585-2010 NR 50 TC 113 Z9 118 U1 3 U2 20 PU SPRINGER PI NEW YORK PA 233 SPRING ST, NEW YORK, NY 10013 USA SN 0722-4028 EI 1432-0975 J9 CORAL REEFS JI Coral Reefs PD APR PY 1996 VL 15 IS 2 BP 109 EP 119 PG 11 WC Marine & Freshwater Biology SC Marine & Freshwater Biology GA UK416 UT WOS:A1996UK41600005 ER PT J AU Rule, DL Smith, DR Sparks, LL AF Rule, DL Smith, DR Sparks, LL TI Thermal conductivity of polypyromellitimide film with alumina filler particles from 4.2 to 300 K SO CRYOGENICS LA English DT Article DE alumina; contact resistance; Kapton; polypyromellitimide film; thermal conductivity ID POLYMER-FILMS AB The thermal conductivities of several types of a commercial polyimide (namely polypyromellitimide, PPMI) film were measured over a range of temperatures from 4.2 to 300 K with an unguarded steady state parallel-plate apparatus. Specimens were made by stacking multiple layers of film together. Conductive grease was used between the layers of film to reduce thermal contact resistance. Two specimens were made from two different types of neat film with a thickness of 76 mu m, and three specimens were made from films that contained two different amounts of alumina filler and had thicknesses of 25 or 76 mu m. The conductivity of PPMI film increases with the amount of alumina filler present. The thermal conductivity of specimens made from film of the same type but of different thickness is independent of film thickness, within the limits of experimental uncertainty. The conductivity of a specimen subjected to a simulated curing process by being held at a temperature of 150 degrees C for 90 min was indistinguishable from that of a similar, control specimen not subjected to such treatment. C1 NATL INST STAND & TECHNOL,DIV MAT RELIABIL,BOULDER,CO 80303. NR 19 TC 9 Z9 10 U1 0 U2 6 PU BUTTERWORTH-HEINEMANN LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD, OXON, ENGLAND OX5 1GB SN 0011-2275 J9 CRYOGENICS JI Cryogenics PD APR PY 1996 VL 36 IS 4 BP 283 EP 290 DI 10.1016/0011-2275(96)88788-1 PG 8 WC Thermodynamics; Physics, Applied SC Thermodynamics; Physics GA UA223 UT WOS:A1996UA22300010 ER PT J AU Wijffels, SE Toole, JM Bryden, HL Fine, RA Jenkins, WJ Bullister, JL AF Wijffels, SE Toole, JM Bryden, HL Fine, RA Jenkins, WJ Bullister, JL TI The water masses and circulation at 10 degrees N in the Pacific SO DEEP-SEA RESEARCH PART I-OCEANOGRAPHIC RESEARCH PAPERS LA English DT Article ID OCEAN HEAT-TRANSPORT; NORTH PACIFIC; WIND STRESS; TROPICAL PACIFIC; INTERMEDIATE WATER; MINDANAO CURRENT; FLUXES; DEEP; VARIABILITY; NUTRIENT AB The circulation and distribution of water masses near the southern boundary of the North Pacific Basin are described, based on a recent hydrographic survey made at 10 degrees N. A circulation scheme is found, using both the tracer data and a box inverse model. To ensure the best possible realization of the mean state, repeat survey data are used in the boundary current. Historical data are used to check the representativeness of the transport across the onetime section outside of the boundary current. The upper 400 m are dominated by the North Pacific tropical Sverdrup cell, where the net interior flow is to the north, compensated by an equatorward low-latitude boundary flow: the Mindanao Current. The tropical cell is highly baroclinic in the sense that 18 Sv (1 Sv=1x10(6) m(3) s(-1)) of tropical surface water flows northwards and is returned southward entirely within the shallow tropical thermocline: half in a broad interior flow and half in the southward boundary current. The strongly baroclinic structure of the tropical cell allows for the efficient transport of North Pacific subtropical water masses across the gyre boundary. The tropical cell is responsible for nearly all of the 0.7+/-0.5 PW of heat transported northwards across the section. There is essentially zero freshwater divergence over the North Pacific north of 10 degrees N. Critical to the salt balance of the North Pacific basin is a poleward flux of salty subthermocline water which ultimately derives from the South Pacific subtropical gyre. The South Pacific water found along 10 degrees N has temperatures and salinities characteristic of the 13 degrees C Thermostad found at the equator, suggestive of a link via the eastern Pacific. At depth, the analysis reveals a deep meridional overturning in the North Pacific consisting of the import across 10 degrees N of 8 Sv of bottom waters of Antarctic origin and their subsequent conversion and export as North Pacific Deep Water. Dominating the mid-depth property distribution and circulation is a deep anticyclonic cell which horizontally cycles 8 Sv of deep water through the North Pacific basin. We find that there is little interaction between the North Pacific wind-driven circulation and the abyssal volume, which contrasts with the Atlantic Ocean. in which there is strong communication between the cold and warm water volumes. 1996 Published by Elsevier Science Ltd. C1 WOODS HOLE OCEANOG INST,DEPT PHYS OCEANOG,WOODS HOLE,MA 02543. CHILLWORTH RES CTR,RENNELL CTR,SOUTHAMPTON SO2 7NS,HANTS,ENGLAND. UNIV MIAMI,ROSENSTIEL SCH MARINE & ATMOSPHER SCI,MIAMI,FL 33149. WOODS HOLE OCEANOG INST,DEPT MARINE CHEM & GEOCHEM,WOODS HOLE,MA 02543. NOAA,PACIFIC MARINE ENVIRONM LAB,SEATTLE,WA 98115. RI Wijffels, Susan/I-8215-2012 NR 81 TC 63 Z9 65 U1 2 U2 12 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 APR PY 1996 VL 43 IS 4 BP 501 EP 544 DI 10.1016/0967-0637(96)00006-4 PG 44 WC Oceanography SC Oceanography GA VE618 UT WOS:A1996VE61800006 ER PT J AU Klouda, GA Lewis, CW Rasmussen, RA Rhoderick, GC Sams, RL Stevens, RK Currie, LA Donahue, DJ Jull, AJT Seila, RL AF Klouda, GA Lewis, CW Rasmussen, RA Rhoderick, GC Sams, RL Stevens, RK Currie, LA Donahue, DJ Jull, AJT Seila, RL TI Radiocarbon measurements of atmospheric volatile organic compounds: Quantifying the biogenic contribution SO ENVIRONMENTAL SCIENCE & TECHNOLOGY LA English DT Article ID ACCELERATOR MASS-SPECTROMETRY; C-14; CO2 AB The radiocarbon (C-14) abundance of atmospheric volatile organic compounds (VOC) gives a quantitative estimate of contributions from biomass and fossil-mass sources, important information for effective regulation of ozone precursors. We report here details of a methodology to perform such measurements and the first exploratory C-14 results on VOC fractions separated from two composited urban tropospheric air samples, collected during the summer (1992) in Atlanta, GA. The upper limit of the percentage of VOC originating from biomass sources during the morning and evening hours in Atlanta were 9 and 17%, respectively, measurements reported at the 95% confidence level. However, due to the level of the process blank and its uncertainty, in both cases the percentage can be as low as zero. The results of these experiments, designed to (i) evaluate the entire [C-14]VOC measurement process and (ii) obtain reliable estimates of biogenic contributions to atmospheric VOC, emphasize how important controls are throughout this multi-step chemical process to ensure quality data. C1 US EPA,RES TRIANGLE PK,NC 27711. OREGON GRAD INST,BEAVERTON,OR 97006. UNIV ARIZONA,NSF,FACIL RADIOISTOPE ANAL,TUCSON,AZ 85721. RP Klouda, GA (reprint author), NIST,GAITHERSBURG,MD 20899, USA. NR 25 TC 26 Z9 26 U1 0 U2 4 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 SN 0013-936X J9 ENVIRON SCI TECHNOL JI Environ. Sci. Technol. PD APR PY 1996 VL 30 IS 4 BP 1098 EP 1105 DI 10.1021/es9501981 PG 8 WC Engineering, Environmental; Environmental Sciences SC Engineering; Environmental Sciences & Ecology GA UC413 UT WOS:A1996UC41300027 ER PT J AU Brodziak, JKT Macy, WK AF Brodziak, JKT Macy, WK TI Growth of long-finned squid, Loligo pealei, in the northwest Atlantic SO FISHERY BULLETIN LA English DT Article ID STATOLITH MICROSTRUCTURE; SEXUAL MATURITY; AGE; INCREMENTS; CEPHALOPODS; NEWFOUNDLAND; MATURATION; FISHERY; WATERS; SHELF AB The application of statolith ageing techniques to long-finned squid, Loligo pealei, suggests that this species has a life span of less than one year and grows more rapidly than previously thought. In this study we provide direct estimates of growth for long-finned squid in the northwest Atlantic based on a data set of 353 animals aged by counting putative daily statolith increments. We examine empirical patterns in length and weight at age and estimate parameters of a general growth model. The results indicate that growth rate increases rapidly as squid age and that growth in length and weight is exponential. Although there is substantial heterogeneity in L. pealei size at age, sexual dimorphism is evident: males grow more rapidly than do females and achieve larger sizes. Backcalculated hatching dates show that L. pealei spawning is not restricted to spring through late-autumn, as previously supposed, but occurs during winter months as well. Differences between growth rates of squid hatched during June-October and November-May are suggested and lend support to the hypothesis that growth can be influenced by seasonal environmental conditions. We discuss the practical implications of our findings for the assessment and management of the long-finned squid stock in the northwest Atlantic. C1 NATL MARINE FISHERIES SERV,NE FISHERIES SCI CTR,NOAA,WOODS HOLE,MA 02543. UNIV RHODE ISL,GRAD SCH OCEANOG,NARRAGANSETT,RI 02882. NR 71 TC 61 Z9 64 U1 0 U2 1 PU NATL MARINE FISHERIES SERVICE SCIENTIFIC PUBL OFFICE PI SEATTLE PA 7600 SAND POINT WAY NE BIN C15700, SEATTLE, WA 98115 SN 0090-0656 J9 FISH B-NOAA JI Fish. Bull. PD APR PY 1996 VL 94 IS 2 BP 212 EP 236 PG 25 WC Fisheries SC Fisheries GA UC962 UT WOS:A1996UC96200002 ER PT J AU Caillouet, CW Shaver, DJ Teas, WG Nance, JM Revera, DB Cannon, AC AF Caillouet, CW Shaver, DJ Teas, WG Nance, JM Revera, DB Cannon, AC TI Relationship between sea turtle stranding rates and shrimp fishing intensities in the northwestern Gulf of Mexico: 1986-1989 versus 1990-1993 SO FISHERY BULLETIN LA English DT Article ID LEPIDOCHELYS-KEMPI; RIDLEY AB This paper tested the null hypothesis that the statistical relationship between monthly sea turtle (species combined) stranding rates (strandings per 100 km of accessible shoreline) and monthly shrimp fishing intensities (days fished per 100 km(2)) in the northwestern Gulf of Mexico was the same in 1990-93 as in 1986-89. The expectation was that regulations requiring use of turtle excluder devices (TED's) in shrimp trawls during 1990-93 would reduce the incidental catch of sea turtles and thereby diminish or eliminate the statistical relationship between stranding rates and fishing intensities. Significant positive correlations were detected between the log-transformed stranding rates and fishing intensities for shrimping landward of the 20-fathom (36.6-m) contour in 1990-93. The null hypothesis was not rejected; therefore TED regulations did not result in diminishing or eliminating the statistical relationship between sea turtle stranding rates and shrimp fishing intensities in the northwestern Gulf. Various hypotheses were suggested as possible explanations. C1 NATL BIOL SERV,PADRE ISL NATL SEASHORE,US DEPT INTERIOR,CORPUS CHRISTI,TX 78418. NATL MARINE FISHERIES SERV,MIAMI LAB,SE FISHERIES SCI CTR,NOAA,MIAMI,FL 33149. RP Caillouet, CW (reprint author), NATL MARINE FISHERIES SERV,GALVESTON LAB,SE FISHERIES SCI CTR,NOAA,4600 AVE U,GALVESTON,TX 77551, USA. NR 22 TC 23 Z9 26 U1 0 U2 8 PU NATL MARINE FISHERIES SERVICE SCIENTIFIC PUBL OFFICE PI SEATTLE PA 7600 SAND POINT WAY NE BIN C15700, SEATTLE, WA 98115 SN 0090-0656 J9 FISH B-NOAA JI Fish. Bull. PD APR PY 1996 VL 94 IS 2 BP 237 EP 249 PG 13 WC Fisheries SC Fisheries GA UC962 UT WOS:A1996UC96200003 ER PT J AU DeMartini, EE Parrish, FA Ellis, DM AF DeMartini, EE Parrish, FA Ellis, DM TI Barotrauma-associated regurgitation of food: Implications for diet studies of Hawaiian pink snapper, Pristipomoides filamentosus (family Lutjanidae) SO FISHERY BULLETIN LA English DT Article ID STOMACH CONTENTS; FISHES; COD AB Juvenile (128-244 mm fork length) pink snapper, Pristipomoides filamentosus, were caught by hook and line from 60-90 m depths offshore of Kaneohe Bay, windward Oahu, Hawaii, during February-August 1994. About one-half of the 180 specimens were intercepted by scuba divers 15-18 m below the sea surface and individually ''bagged'' live before they were retrieved for the remaining distance to the surface. The other half were retrieved directly by fishing line to the surface (''unbagged''); these latter fish thus remained at a continual risk of prey loss from regurgitation while they were stressed by the full extent of pressure change. The retained stomach contents of bagged and unbagged fish were compared on the basis of volume and type of food and on the size of individual prey items. Bagged samples of juvenile snapper on average retained a 116% (95% CI=70-157%) greater volume of prey than unbagged snapper; bagged snapper also had more types and greater maximum body sizes of prey than did unbagged fish. These results are discussed in terms of designing quantitative diet studies for juvenile snapper and other deep-water physoclistous fishes. RP DeMartini, EE (reprint author), NATL MARINE FISHERIES SERV,HONOLULU LAB,SW FISHERIES SCI CTR,NOAA,2570 DOLE ST,HONOLULU,HI 96822, USA. NR 19 TC 12 Z9 12 U1 0 U2 3 PU NATL MARINE FISHERIES SERVICE SCIENTIFIC PUBL OFFICE PI SEATTLE PA 7600 SAND POINT WAY NE BIN C15700, SEATTLE, WA 98115 SN 0090-0656 J9 FISH B-NOAA JI Fish. Bull. PD APR PY 1996 VL 94 IS 2 BP 250 EP 256 PG 7 WC Fisheries SC Fisheries GA UC962 UT WOS:A1996UC96200004 ER PT J AU Krieger, KJ Sigler, MF AF Krieger, KJ Sigler, MF TI Catchability coefficient for rockfish estimated from trawl and submersible surveys SO FISHERY BULLETIN LA English DT Article AB A bottom-trawl catchability coefficient was estimated for rockfish by comparing trawl catch rates to densities estimated from a manned submersible. A total of 16 comparisons were completed in 1989 and 1991 at depths of 180-283 m. Pacific ocean perch, Sebastes alutus, was the target species and accounted for 72% of the rockfish caught in the trawl. The seafloor area sampled by the trawl was calculated from the distance between the wingtips of the net and the distance the net traveled across the seafloor. The seafloor area sampled from the submersible was calculated from the distance the submersible traveled and the lateral range of visibility. A larger volume of water was sampled from the submersible because counts of rockfish included fish to 7 m above the seafloor, whereas the vertical opening of the trawl was 1.8 m; approximately 50% of the rockfish observed from the submersible were >1.8 m above the seafloor. Even though a larger volume of water was sampled from the submersible, catchability coefficients of 0.97 and 1.27 were estimated for minimum and maximum detection probabilities of rockfish from the submersible. Apparently, rockfish dove or were herded horizontally into the opening of the net. Density estimates of rockfish and other groundfish species are feasible from a submersible, and these estimates can be used to determine bottom-trawl catchability coefficients. RP Krieger, KJ (reprint author), NATL MARINE FISHERIES SERV,AUKE BAY LAB,ALASKA FISHERIES SCI CTR,NOAA,11305 GLACIER HWY,JUNEAU,AK 99801, USA. NR 15 TC 10 Z9 10 U1 0 U2 2 PU NATL MARINE FISHERIES SERVICE SCIENTIFIC PUBL OFFICE PI SEATTLE PA 7600 SAND POINT WAY NE BIN C15700, SEATTLE, WA 98115 SN 0090-0656 J9 FISH B-NOAA JI Fish. Bull. PD APR PY 1996 VL 94 IS 2 BP 282 EP 288 PG 7 WC Fisheries SC Fisheries GA UC962 UT WOS:A1996UC96200007 ER PT J AU Laidig, TE Sakuma, KM Nishimoto, MM AF Laidig, TE Sakuma, KM Nishimoto, MM TI Description of pelagic larval and juvenile stripetail rockfish, Sebastes saxicola (family Scorpaenidae), with an examination of larval growth SO FISHERY BULLETIN LA English DT Article ID CALIFORNIA; OREGON AB Pigmentation, morphometrics, head spination, fin development, and meristic characters were described and illustrated for the developmental series of larval and pelagic juvenile (4.7-38.2 mm standard length) stripetail rockfish, Sebastes saxicola. Pigment patterns were sufficiently distinct to differentiate larval and juvenile S. saxicola from other Sebastes species occurring in the study area (central California). Early larvae of S. saxicola were identified by the presence of pigment on the postanal ventral midline and the nape and by the lack of pigment on the lower jaw and the pectoral fins. Late larval S. saxicola had areas of intense pigment along the dorsal, lateral, and ventral midlines. Juvenile S. saxicola were identified by their distinctive bar pattern and meristic characters. Examination of otolith characters indicated that the extrusion check radius of S. saxicola differed from that of other Sebastes species examined. Otolith characters, used in combination with pigment patterns, readily separated larval S. saxicola from other Sebastes species. Calculated growth rates for S. saxicola were slower than most previously reported growth rates for other Sebastes species. C1 MOSS LANDING MARINE LABS,MOSS LANDING,CA 95039. RP Laidig, TE (reprint author), NATL MARINE FISHERIES SERV,TIBURON LAB,SW FISHERIES SCI CTR,NOAA,3150 PARADISE DR,TIBURON,CA 94920, USA. NR 21 TC 15 Z9 15 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 APR PY 1996 VL 94 IS 2 BP 289 EP 299 PG 11 WC Fisheries SC Fisheries GA UC962 UT WOS:A1996UC96200008 ER PT J AU Perkins, PC Edwards, EF AF Perkins, PC Edwards, EF TI A mixture model for estimating discarded bycatch from data with many zero observations: Tuna discards in the eastern tropical Pacific Ocean SO FISHERY BULLETIN LA English DT Article ID POISSON REGRESSION AB Fisheries discard data are often characterized by a smooth distribution of positive amounts of per-set discard but with an extremely large number of zero observations. This discontinuity is difficult to fit with a standard distribution. One approach is to model per-set discard with a mixture of two distributions, with one component representing the zero observations and the other representing the observations of positive discard. In this paper, we describe such a mixture model that is suitable when the discard observations have been rounded to integer amounts. In particular, when ''rounded'' zeros (representing small amounts of discard) and ''true'' zeros (representing no discard) are indistinguishable in the data, the mixture model can be used to estimate the proportion of either. We fit this model to tuna discard data collected by observers aboard the U.S. tuna purse-seine fleet in the eastern tropical Pacific Ocean during the years 1989-92. We use the model to estimate discard per set, allowing the model parameters to depend upon fishing strategy and geographic location, and we estimate mean discard per set fisherywide. RP Perkins, PC (reprint author), NATL MARINE FISHERIES SERV,SW FISHERIES SCI CTR,NOAA,POB 271,LA JOLLA,CA 92038, USA. NR 16 TC 9 Z9 9 U1 2 U2 4 PU NATL MARINE FISHERIES SERVICE SCIENTIFIC PUBL OFFICE PI SEATTLE PA 7600 SAND POINT WAY NE BIN C15700, SEATTLE, WA 98115 SN 0090-0656 J9 FISH B-NOAA JI Fish. Bull. PD APR PY 1996 VL 94 IS 2 BP 330 EP 340 PG 11 WC Fisheries SC Fisheries GA UC962 UT WOS:A1996UC96200011 ER PT J AU Somerton, DA Donaldson, W AF Somerton, DA Donaldson, W TI Contribution to the biology of the grooved and triangle Tanner crabs, Chionoecetes tanneri and C-angulatus, in the eastern Bering Sea SO FISHERY BULLETIN LA English DT Article ID MATURITY; OPILIO AB Populations of the grooved Tanner crab, Chionoecetes tanneri, and the triangle Tanner crab, C. angulatus, were surveyed along the continental slope of the eastern Bering Sea with a bottom trawl. Over the depth range sampled (100-1,000 m), the relative abundance of the two species was about equal. Mature male and female C. tanneri occurred at the same depths, but for C. angulatus, males were found at significantly shallower depths than were females. Carapace widths at 50% maturity for males and females were 118.7 mm and 79.2 mm for C. tanneri and 91.4 mm and 57.8 mm for C. angulatus. Fecundity of C. tanneri did not increase with carapace width (CW, mm) and averaged 86,500 eggs over the sizes sampled. Fecundity of C. angulatus increased with carapace width according to the following formula: eggs = -65,600 + 1660 x CW. Mean egg diameter was 0.75 mm for C. tanneri and 0.74 mm for C. angulatus. The relationship between body weight (gm) and carapace width did not differ between species: weight = 1.219/10(4) x CW3.183. C1 ALASKA DEPT FISH & GAME,KODIAK,AK 99615. RP Somerton, DA (reprint author), NATL MARINE FISHERIES SERV,ALASKA FISHERIES SCI CTR,NOAA,7600 SAND POINT WAY NE,SEATTLE,WA 98115, USA. NR 29 TC 12 Z9 12 U1 0 U2 0 PU NATL MARINE FISHERIES SERVICE SCIENTIFIC PUBL OFFICE PI SEATTLE PA 7600 SAND POINT WAY NE BIN C15700, SEATTLE, WA 98115 SN 0090-0656 J9 FISH B-NOAA JI Fish. Bull. PD APR PY 1996 VL 94 IS 2 BP 348 EP 357 PG 10 WC Fisheries SC Fisheries GA UC962 UT WOS:A1996UC96200013 ER PT J AU Zimmermann, M Goddard, P AF Zimmermann, M Goddard, P TI Biology and distribution of arrowtooth, Atheresthes stomias, and Kamchatka, A-evermanni, flounders in Alaskan waters SO FISHERY BULLETIN LA English DT Article AB The biology and distribution of arrowtooth, Atheresthes stomias, and Kamchatka, A. evermanni, flounder were examined in Alaskan waters to determine whether there were sufficient differences to justify treating them as separate species in resource assessment surveys conducted by the National Marine Fisheries Service. Geographic ranges of the two flounder species overlap in Alaska waters; both occur in the eastern Bering Sea and western Aleutian Islands region. However, only arrowtooth flounder occur throughout the eastern Aleutian Islands region and the Gulf of Alaska. Arrowtooth flounder were abundant over a wide range of depths (76-450 m) and were more abundant than Kamchatka flounder in catches shallower than 325 m. Kamchatka flounder were abundant only in deep trawl hauls (226-500 m) and were more abundant than arrowtooth flounder in catches at depths greater than 375 m. Arrowtooth flounder were also abundant over a wide range of bottom-water temperatures (2.1 degrees-4.6 degrees C), whereas Kamchatka flounder were abundant in a much narrower range of bottom temperatures (3.8 degrees-4.2 degrees C). By percentage, females dominated the arrowtooth flounder population in the eastern Bering Sea (68.6%) and Aleutian Islands region (59.6%), whereas the Kamchatka flounder population was 55.9% and 47.5% female, respectively. The females of both species attained greater length at age than did the males. The difference in growth between the sexes was greater among arrowtooth flounder and may account for the preponderance of females in the arrowtooth flounder population. RP Zimmermann, M (reprint author), NATL MARINE FISHERIES SERV,ALASKA FISHERIES SCI CTR,NOAA,7600 SAND POINT WAY NE,SEATTLE,WA 98115, USA. NR 25 TC 6 Z9 6 U1 2 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 APR PY 1996 VL 94 IS 2 BP 358 EP 370 PG 13 WC Fisheries SC Fisheries GA UC962 UT WOS:A1996UC96200014 ER PT J AU Read, AJ Nicolas, JR Craddock, JE AF Read, AJ Nicolas, JR Craddock, JE TI Winter capture of a harbor porpoise in a pelagic drift net off North Carolina SO FISHERY BULLETIN LA English DT Article ID FUNDY; BAY C1 WOODS HOLE OCEANOG INST,WOODS HOLE,MA 02543. NATL MARINE FISHERIES SERV,NE FISHERIES SCI CTR,NOAA,WOODS HOLE,MA 02543. NR 10 TC 9 Z9 9 U1 0 U2 0 PU NATL MARINE FISHERIES SERVICE SCIENTIFIC PUBL OFFICE PI SEATTLE PA 7600 SAND POINT WAY NE BIN C15700, SEATTLE, WA 98115 SN 0090-0656 J9 FISH B-NOAA JI Fish. Bull. PD APR PY 1996 VL 94 IS 2 BP 381 EP 383 PG 3 WC Fisheries SC Fisheries GA UC962 UT WOS:A1996UC96200017 ER PT J AU Auzerais, FM Dunsmuir, J Ferreol, BB Martys, N Olson, J Ramakrishnan, TS Rothman, DH Schwartz, LM AF Auzerais, FM Dunsmuir, J Ferreol, BB Martys, N Olson, J Ramakrishnan, TS Rothman, DH Schwartz, LM TI Transport in sandstone: A study based on three dimensional microtomography SO GEOPHYSICAL RESEARCH LETTERS LA English DT Article ID LATTICE-BOLTZMANN AB High resolution imaging of the microstructure of Fontainebleau sandstone allows a direct comparison between theoretical calculations and laboratory measurements. While porosity, pore-volume-to-surface ratio, permeability, and end point relative permeability are well predicted by our calculations, we find that electrical resistivity and wetting phase residual saturation are both overestimated. C1 EXXON RES & ENGN CO,ANNANDALE,NJ 08801. NATL INST STAND & TECHNOL,BLDG MAT DIV,GAITHERSBURG,MD 20899. MIT,DEPT EARTH ATMOSPHER & PLANETARY SCI,CAMBRIDGE,MA 02139. RP Auzerais, FM (reprint author), SCHLUMBERGER DOLL RES CTR,OLD QUARRY RD,RIDGEFIELD,CT 06877, USA. NR 15 TC 143 Z9 144 U1 1 U2 18 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 SN 0094-8276 J9 GEOPHYS RES LETT JI Geophys. Res. Lett. PD APR 1 PY 1996 VL 23 IS 7 BP 705 EP 708 DI 10.1029/96GL00776 PG 4 WC Geosciences, Multidisciplinary SC Geology GA UD380 UT WOS:A1996UD38000003 ER PT J AU Baumgardner, D Dye, JE Gandrud, B Barr, K Kelly, K Chan, KR AF Baumgardner, D Dye, JE Gandrud, B Barr, K Kelly, K Chan, KR TI Refractive, indices of aerosols in the upper troposphere and lower stratosphere SO GEOPHYSICAL RESEARCH LETTERS LA English DT Article AB A new instrument for simultaneously measuring aerosol diameter from 0.4 - 10 mu m and the refractive index between 1.30 - 1.60 has recently been flown on the NASA ER-2 aircraft during a stratospheric measurement campaign. Average stratospheric refractive indices varied from 1.40 to 1.42 over a latitude range from 70 degrees S to 50 degrees N and from 1.34 to 1.46 over a vertical range from 4 - 20 km. The measured stratospheric refractive indices do not agree well with theoretical predictions and vertical profiles suggest the presence of non-spherical or absorbing particles in the altitude range of 7 - 9 km. C1 NASA,AMES RES CTR,MOFFETT FIELD,CA 94035. NOAA,AERON LAB,BOULDER,CO 80303. RP Baumgardner, D (reprint author), NATL CTR ATMOSPHER RES,POB 3000,BOULDER,CO 80307, USA. NR 17 TC 46 Z9 46 U1 0 U2 1 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 SN 0094-8276 J9 GEOPHYS RES LETT JI Geophys. Res. Lett. PD APR 1 PY 1996 VL 23 IS 7 BP 749 EP 752 DI 10.1029/96GL00707 PG 4 WC Geosciences, Multidisciplinary SC Geology GA UD380 UT WOS:A1996UD38000014 ER PT J AU Traynor, JJ AF Traynor, JJ TI Target-strength measurements of walleye pollock (Theragra chalcogramma) and Pacific whiting (Merluccius productus) SO ICES JOURNAL OF MARINE SCIENCE LA English DT Article; Proceedings Paper CT ICES International Symposium on Fisheries and Plankton Acoustics CY JUN 12-16, 1995 CL MARINE LAB, ABERDEEN, SCOTLAND SP Int Council Explorat Sea, Inst Acoust, Acoust Soc Amer, Soc Francaise Acoust HO MARINE LAB DE acoustics; Merluccius productus; Pacific whiting; target strength; Theragra chalcogramma; walleye pollock AB The importance of knowledge about the target-strength (TS) characteristics of the surveyed fish population to the accuracy of acoustic assessments using echo integration is well known. The most commonly used TS to length (L) relationship for walleye pollock is based on swimbladder morphology measurements and in situ TS measurements TS (in dB)=20 log L - 66.0 for fish length in centimeters. For Pacific whiting, TS measurements have not been made over an adequate range of fish lengths to determine the appropriate relationship for use in scaling echo-integration surveys. However, results presented in this paper and elsewhere suggest a smaller TS (about 2 dB for a given length) for 40-60 cm fish. Measurements of the TS of walleye pollock and Pacific whiting were made with a SIMRAD EK500 in the present study. The appropriateness of the currently used TS to length relationship for echo integration scaling is discussed for pollock. The application of a TS to length relationship for Pacific whiting is considered. An attempt to use a system with a transducer lowered through the water column to reduce noise-induced bias is described. (C) 1996 International Council for the Exploration of the Sea RP Traynor, JJ (reprint author), ALASKA FISHERIES SCI CTR,7600 SAND POINT WAY NE,SEATTLE,WA 98115, USA. NR 16 TC 60 Z9 61 U1 0 U2 2 PU ACADEMIC PRESS LTD PI LONDON PA 24-28 OVAL RD, LONDON, ENGLAND NW1 7DX SN 1054-3139 J9 ICES J MAR SCI JI ICES J. Mar. Sci. PD APR PY 1996 VL 53 IS 2 BP 253 EP 258 DI 10.1006/jmsc.1996.0031 PG 6 WC Fisheries; Marine & Freshwater Biology; Oceanography SC Fisheries; Marine & Freshwater Biology; Oceanography GA UJ679 UT WOS:A1996UJ67900020 ER PT J AU Hewitt, RP Demer, DA AF Hewitt, RP Demer, DA TI Lateral target strength of Antarctic krill SO ICES JOURNAL OF MARINE SCIENCE LA English DT Article; Proceedings Paper CT ICES International Symposium on Fisheries and Plankton Acoustics CY JUN 12-16, 1995 CL MARINE LAB, ABERDEEN, SCOTLAND SP Int Council Explorat Sea, Inst Acoust, Acoust Soc Amer, Soc Francaise Acoust HO MARINE LAB DE target strength; Antarctic krill; Euphausia superba ID ORIENTATION; ABUNDANCE AB An area of high krill (Euphausia superba Dana) density was continuously monitored with down-looking and side-looking sonars over a period of 24 h. Measurements of volume backscattering strength were used to describe the density of krill with depth and the vertical movement of krill over time. In situ measurements were made of dorsal aspect target strength (TS) and, as krill moved into the near-surface layer (0-15 m), in situ measurements were made of lateral-aspect TS. The probability density function (PDF) of TS measurements made with the down-looking transducer had a mode at approximately - 73 dB. The PDF of TS measurements made with the side-looking transducer was broader with a mode at approximately - 67 dB. Sampled krill had a bi-modal length distribution with a major mode at 44 mm and a minor mode at approximately 30 mm. (C) 1996 International Council for the Exploration of the Sea RP Hewitt, RP (reprint author), SW FISHERIES SCI CTR,POB 271,LA JOLLA,CA 92038, USA. NR 19 TC 16 Z9 16 U1 1 U2 1 PU ACADEMIC PRESS LTD PI LONDON PA 24-28 OVAL RD, LONDON, ENGLAND NW1 7DX SN 1054-3139 J9 ICES J MAR SCI JI ICES J. Mar. Sci. PD APR PY 1996 VL 53 IS 2 BP 297 EP 302 DI 10.1006/jmsc.1996.0038 PG 6 WC Fisheries; Marine & Freshwater Biology; Oceanography SC Fisheries; Marine & Freshwater Biology; Oceanography GA UJ679 UT WOS:A1996UJ67900027 ER PT J AU Williamson, NJ Traynor, JJ AF Williamson, NJ Traynor, JJ TI Application of a one-dimensional geostatistical procedure to fisheries acoustic surveys of Alaskan pollock SO ICES JOURNAL OF MARINE SCIENCE LA English DT Article; Proceedings Paper CT ICES International Symposium on Fisheries and Plankton Acoustics CY JUN 12-16, 1995 CL MARINE LAB, ABERDEEN, SCOTLAND SP Int Council Explorat Sea, Inst Acoust, Acoust Soc Amer, Soc Francaise Acoust HO MARINE LAB DE acoustics; geostatistics; pollock AB The transitive theory in geostatistics provides an approach for the estimation of variance and characterization of spatial structure in fisheries acoustic surveys. For equally spaced, parallel transect surveys, the acoustic data collected along a transect can be summed and represented by a single value, thus reducing the problem to one dimension. This methodology is applied to acoustic surveys of walleye pollock in Alaska. Results show similarity in spatial structure within areas between years, and differences between areas. Estimation errors are computed for each survey, and compared by region and year and, under certain assumptions, for varying intertransect distances. An attempt is made to validate the technique with empirical data from replicate surveys in the Shelikof Strait. (C) 1996 International Council for the Exploration of the Sea. RP Williamson, NJ (reprint author), ALASKA FISHERIES SCI CTR,7600 SAND POINT WAY NE,SEATTLE,WA 98115, USA. NR 8 TC 18 Z9 18 U1 0 U2 1 PU ACADEMIC PRESS LTD PI LONDON PA 24-28 OVAL RD, LONDON, ENGLAND NW1 7DX SN 1054-3139 J9 ICES J MAR SCI JI ICES J. Mar. Sci. PD APR PY 1996 VL 53 IS 2 BP 423 EP 428 DI 10.1006/jmsc.1996.0059 PG 6 WC Fisheries; Marine & Freshwater Biology; Oceanography SC Fisheries; Marine & Freshwater Biology; Oceanography GA UJ679 UT WOS:A1996UJ67900048 ER PT J AU Gledhill, CT LyczkowskiShultz, J Rademacher, K Kargard, E Crist, G Grace, MA AF Gledhill, CT LyczkowskiShultz, J Rademacher, K Kargard, E Crist, G Grace, MA TI Evaluation of video and acoustic index methods for assessing reef-fish populations SO ICES JOURNAL OF MARINE SCIENCE LA English DT Article; Proceedings Paper CT ICES International Symposium on Fisheries and Plankton Acoustics CY JUN 12-16, 1995 CL MARINE LAB, ABERDEEN, SCOTLAND SP Int Council Explorat Sea, Inst Acoust, Acoust Soc Amer, Soc Francaise Acoust HO MARINE LAB DE fisheries acoustics; reef fish; video camera AB Since 1991, the National Marine Fisheries Service (NMFS) has used a video camera/trap system to assess the relative abundance of reef fishes in the Gulf of Mexico occurring on natural hard-bottom substrata at depths between 9 m and 110 m. The relative index of reef-fish abundance resulting from these annual Gulf-wide surveys is based on counts of fish recorded during a 1 h set of a video camera on the bottom. During the 1993 reef-fish survey, a total of 115 reef sites were sampled with a video camera and fisheries acoustic system. Video data were used to identify fish species distributed above the bottom. Off-bottom fish included snappers (Lutjanidae), groupers (Serranidae), and amberjacks (Seriola spp.), species of interest to commercial and recreational fisheries. Correlation between total off-bottom taxa abundance and volume backscatter was low (r=0.41, n=115). The low correlation may be caused by differences in the area sampled by the video camera and acoustic systems al each site. The low correlation limits the use of acoustic data as an auxiliary variable in a combined video-acoustic estimator. (C) 1996 International Council for the Exploration of the Sea. C1 NATL MARINE FISHERIES SERV,SE FISHERIES SCI CTR,MISSISSIPPI LABS,PASCAGOULA,MS 39568. RP Gledhill, CT (reprint author), UNIV S ALABAMA,DEPT MARINE SCI,MOBILE,AL 36688, USA. NR 3 TC 21 Z9 22 U1 0 U2 5 PU ACADEMIC PRESS LTD PI LONDON PA 24-28 OVAL RD, LONDON, ENGLAND NW1 7DX SN 1054-3139 J9 ICES J MAR SCI JI ICES J. Mar. Sci. PD APR PY 1996 VL 53 IS 2 BP 483 EP 485 DI 10.1006/jmsc.1996.0069 PG 3 WC Fisheries; Marine & Freshwater Biology; Oceanography SC Fisheries; Marine & Freshwater Biology; Oceanography GA UJ679 UT WOS:A1996UJ67900058 ER PT J AU Huang, HM AF Huang, HM TI An architecture and a methodology for intelligent control SO IEEE EXPERT-INTELLIGENT SYSTEMS & THEIR APPLICATIONS LA English DT Article RP Huang, HM (reprint author), NATL INST STAND & TECHNOL,BLDG 220,RM B124,GAITHERSBURG,MD 20899, USA. NR 13 TC 4 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 0885-9000 J9 IEEE EXPERT JI IEEE Expert-Intell. Syst. Appl. PD APR PY 1996 VL 11 IS 2 BP 46 EP 55 DI 10.1109/64.491281 PG 10 WC Computer Science, Artificial Intelligence; Engineering, Electrical & Electronic SC Computer Science; Engineering GA UD434 UT WOS:A1996UD43400010 ER PT J AU Stenbakken, GN Steiner, R Olsen, PT Williams, E AF Stenbakken, GN Steiner, R Olsen, PT Williams, E TI Methods for aligning the NIST watt-balance SO IEEE TRANSACTIONS ON INSTRUMENTATION AND MEASUREMENT LA English DT Article ID NBS AB The NIST watt-balance has been developed to explore the possibility of monitoring the stability of the mass standard by means of electrical quantum standards, The mass standard is the last basic standard that is kept as an artifact, The watt-balance uses a movable coil in a radial magnetic field to compare the mechanical energy required to lift a kilogram mass in earth's gravity with the electrical energy required to move the coil the same distance in a magnetic field, The electrical energy is monitored in terms of quantized Hall resistance and Josephson junction voltage standards, The accuracy of this experiment depends on a large number of factors, Among them are the ability to align the apparatus so that the movable coil and magnet are coaxial and aligned to the local vertical, Misalignments of the coil and magnet result in forces and torques on the coil, The coil is suspended like a pendulum and responds easily to these torques and horizontal forces, This paper describes a computer program that was written to calculate the shape of the magnetic field and the torques and forces on the movable coil that result from any misalignments, This information is being used to develop an alignment procedure that minimizes misalignments and the errors they cause, This program has enhanced our understanding of the cause of torques about the vertical axis on the coil and the dependence of this torque on the magnetic field gradient. RP Stenbakken, GN (reprint author), US DEPT COMMERCE,NATL INST STAND & TECHNOL,GAITHERSBURG,MD 20899, USA. NR 8 TC 10 Z9 11 U1 0 U2 3 PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017-2394 SN 0018-9456 J9 IEEE T INSTRUM MEAS JI IEEE Trans. Instrum. Meas. PD APR PY 1996 VL 45 IS 2 BP 372 EP 377 DI 10.1109/19.492750 PG 6 WC Engineering, Electrical & Electronic; Instruments & Instrumentation SC Engineering; Instruments & Instrumentation GA UJ897 UT WOS:A1996UJ89700004 ER PT J AU Deyst, JP Souders, TM AF Deyst, JP Souders, TM TI Bounds on frequency response estimates derived from uncertain step response data SO IEEE TRANSACTIONS ON INSTRUMENTATION AND MEASUREMENT LA English DT Article AB The frequency response of a system can be estimated from measurements of its step response; however, many error sources affect the accuracy of such estimates, This paper investigates the effects of uncertainty in the knowledge of the step response, Methods for establishing uncertainty bounds for the frequency response estimates are developed, based on the corresponding time-domain uncertainties associated with the measured step response, Two methods are described, One method produces bounds that are often very conservative. The other method produces bounds that are more realistic, End effects that influence the bounds are also considered, A simulation example and an application of the bounds are presented. RP Deyst, JP (reprint author), NATL INST STAND & TECHNOL,GAITHERSBURG,MD 20899, USA. NR 13 TC 7 Z9 7 U1 0 U2 0 PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017-2394 SN 0018-9456 J9 IEEE T INSTRUM MEAS JI IEEE Trans. Instrum. Meas. PD APR PY 1996 VL 45 IS 2 BP 378 EP 383 DI 10.1109/19.492751 PG 6 WC Engineering, Electrical & Electronic; Instruments & Instrumentation SC Engineering; Instruments & Instrumentation GA UJ897 UT WOS:A1996UJ89700005 ER PT J AU Stenbakken, GN AF Stenbakken, GN TI Effects of nonmodel errors on model-based testing SO IEEE TRANSACTIONS ON INSTRUMENTATION AND MEASUREMENT LA English DT Article AB In previous work, model-based methods have been developed for efficient testing of components and instruments that allow for their full behavior to be predicted from a small set of test measurements, While such methods can significantly reduce the testing cost of such units, these methods are valid only if the model accurately represents the behavior of the units, Previous papers on this subject described many methods for developing accurate models and using them to develop efficient test methods, However, they gave little consideration to the problem of testing units which change their behavior after the model has been developed, for example, as a result of changes in the manufacturing process. Such changed behavior is referred to as nonmodel behavior or nonmodel error, When units with this new behavior are tested with these more efficient methods, their predicted behavior can show significant deviations from their true behavior, This paper describes how to analyze the data taken at the reduced set of measurements to estimate the uncertainty in the model predictions, even when the device has significant nonmodel error, Results of simulation are used to verify the accuracy of the estimates and to show the expected variation in the results for many modeling variables. RP Stenbakken, GN (reprint author), US DEPT COMMERCE,NATL INST STAND & TECHNOL,GAITHERSBURG,MD 20899, USA. NR 8 TC 5 Z9 5 U1 0 U2 0 PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017-2394 SN 0018-9456 J9 IEEE T INSTRUM MEAS JI IEEE Trans. Instrum. Meas. PD APR PY 1996 VL 45 IS 2 BP 384 EP 388 DI 10.1109/19.492752 PG 5 WC Engineering, Electrical & Electronic; Instruments & Instrumentation SC Engineering; Instruments & Instrumentation GA UJ897 UT WOS:A1996UJ89700006 ER PT J AU Laug, OB AF Laug, OB TI A 100 A, 100 kHz transconductance amplifier SO IEEE TRANSACTIONS ON INSTRUMENTATION AND MEASUREMENT LA English DT Article AB A high-current, wide-band transconductance amplifier is described that provides an unprecedented level of output current at high frequencies with exceptional stability, It is capable of converting a signal voltage applied to its input into a ground-referenced output rms current up to 100 A over a frequency range from de to 100 kHz with a useable frequency extending to 1 MHz. The amplifier has a 1000-W output capability +/-10 V of compliance, and can deliver up to 400 A of pulsed peak-to-peak current, The amplifier design is based on the principle of paralleling a number of precision bipolar voltage-to-current converters, The design incorporates a unique ranging system controlled by opto-isolated switches, which permit a full-scale range from 5 A to 100 A, The design considerations for maintaining wide bandwidth, high output impedance, and unconditional stability for all loads are discussed. RP Laug, OB (reprint author), NIST,DIV ELECT,GAITHERSBURG,MD 20899, USA. NR 2 TC 7 Z9 7 U1 0 U2 0 PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017-2394 SN 0018-9456 J9 IEEE T INSTRUM MEAS JI IEEE Trans. Instrum. Meas. PD APR PY 1996 VL 45 IS 2 BP 440 EP 444 DI 10.1109/19.492763 PG 5 WC Engineering, Electrical & Electronic; Instruments & Instrumentation SC Engineering; Instruments & Instrumentation GA UJ897 UT WOS:A1996UJ89700017 ER PT J AU Kim, GJ Lee, S Bekey, GA AF Kim, GJ Lee, S Bekey, GA TI Interleaving assembly planning and design SO IEEE TRANSACTIONS ON ROBOTICS AND AUTOMATION LA English DT Article AB The main objective of assembly planning is to determine a sequence of assembling a product with respect to its geometric and resource constraints, Recent strides toward concurrent engineering have called for a tighter integration of assembly planning with design, because often during assembly planning, one realizes that a significant amount of assembly cost can be cut by redesigning the product itself. Instead of ''retroactively'' redesigning a product upon assembly planning, a concurrent engineering platform must allow its users to evaluate designs (e.g,, with regards to assembly sequencing), and ''proactively'' explore different alternatives at various levels of abstractions so that one can zoom in on ''promising'' design paths and design right within the first few design cycles. This paper presents such an integrated system in which assembly planning becomes an essential part of the design exploration process. An algorithm for assembly planning during design for such an environment is developed, Designing for assembly is more effective and correct because, for a particular sequence of assembly, different design alternatives can be created and evaluated. C1 UNIV SO CALIF,DEPT COMP SCI,LOS ANGELES,CA 90089. CALTECH,JET PROP LAB,PASADENA,CA 91109. RP Kim, GJ (reprint author), NIST,MFG SYST INTEGRAT DIV,ENGN DESIGN TECHNOL GRP,GAITHERSBURG,MD 20899, USA. NR 21 TC 9 Z9 9 U1 0 U2 0 PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017-2394 SN 1042-296X J9 IEEE T ROBOTIC AUTOM JI IEEE Trans. Robot. Autom. PD APR PY 1996 VL 12 IS 2 BP 246 EP 251 DI 10.1109/70.488944 PG 6 WC Automation & Control Systems; Engineering, Electrical & Electronic; Robotics SC Automation & Control Systems; Engineering; Robotics GA UE318 UT WOS:A1996UE31800008 ER PT J AU Predoi, A Lees, RM Xu, LH AF Predoi, A Lees, RM Xu, LH TI Far infrared laser assignments and predictions for CO-stretching and CH3-rocking states of optically pumped (CH3OH)-C-13 SO INFRARED PHYSICS & TECHNOLOGY LA English DT Article ID HIGH-RESOLUTION SPECTROSCOPY; FIR LASER; DOUBLE-RESONANCE; EMISSION; CH3OH; IDENTIFICATION; METHANOL; 13CH3OH; LINES AB High-resolution Fourier transform studies of the CO-stretching and CH3-rocking bands of (CH3OH)-C-13 have been applied to the assignment of far-infrared (FIR) laser transitions optically pumped by CO2 infrared (IR) lasers. The assignments are based on spectroscopic identification of the IR pump transitions at the reported offsets from the CO2 laser lines and agreement between the FIR laser wavenumbers and values calculated from IR/FIR combination-loop relations. Wavenumbers are also predicted for further potential new FIR laser lines in transition systems that could be pumped by CO2 and (CO2)-C-13 cw and waveguide lasers. C1 UNIV NEW BRUNSWICK,DEPT PHYS,FREDERICTON,NB E3B 5A3,CANADA. INST OPTOELECTR,R-76900 BUCHAREST,ROMANIA. NIST,DIV MOLEC PHYS,GAITHERSBURG,MD 20899. RI Xu, Li-Hong/J-5095-2015 NR 27 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 1350-4495 J9 INFRARED PHYS TECHN JI Infrared Phys. Technol. PD APR PY 1996 VL 37 IS 3 BP 351 EP 366 DI 10.1016/1350-4495(95)00067-4 PG 16 WC Instruments & Instrumentation; Optics; Physics, Applied SC Instruments & Instrumentation; Optics; Physics GA UK285 UT WOS:A1996UK28500009 ER PT J AU Bendersky, LA Stalick, JK Portier, R Waterstrat, RM AF Bendersky, LA Stalick, JK Portier, R Waterstrat, RM TI Crystallographic structures and phase transformations in ZrPd SO JOURNAL OF ALLOYS AND COMPOUNDS LA English DT Article DE crystallographic structures; phase transformations; ZrPd AB Phase transformations and crystal structures in the equiatomic compound ZrPd were examined using in-situ heating and cooling in a transmission electron microscope (selected-area diffraction and high resolution imaging) and Rietveld refinement of high resolution neutron powder diffraction data. Three phases were characterized: a high temperature cubic B2-type phase (Pm3m; Z = 1; a = 0.335 97(3) nm at 800 degrees C); an orthorhombic CrB-type phase formed by martensitic transformation from the B2 phase (Cmcm; Z = 4; a = 0.333 19(3) nm, b = 1.0301(1) nm and c = 0.441 11(4) nm at 400 degrees C) and a monoclinic variant of the CrB-type phase at room temperature (assumed space group Cm; Z = 8; a = 0.66611(6) nm, b =0.87499(7) nm, c = 0.542 35(6) nm; beta = 108.21(1)degrees). The monoclinic reversible arrow orthorhombic phase transformation was found to occur reversibly around 200 degrees C. C1 ECOLE NATL SUPER CHIM PARIS,F-67084 PARIS,FRANCE. RP Bendersky, LA (reprint author), NATL INST STAND & TECHNOL,MAT SCI & ENGN LAB,GAITHERSBURG,MD 20899, USA. NR 16 TC 29 Z9 30 U1 1 U2 6 PU ELSEVIER SCIENCE SA LAUSANNE PI LAUSANNE 1 PA PO BOX 564, 1001 LAUSANNE 1, SWITZERLAND SN 0925-8388 J9 J ALLOY COMPD JI J. Alloy. Compd. PD APR 1 PY 1996 VL 236 IS 1-2 BP 19 EP 25 DI 10.1016/0925-8388(96)80046-6 PG 7 WC Chemistry, Physical; Materials Science, Multidisciplinary; Metallurgy & Metallurgical Engineering SC Chemistry; Materials Science; Metallurgy & Metallurgical Engineering GA UH332 UT WOS:A1996UH33200004 ER PT J AU Morrissey, ML Janowiak, JE AF Morrissey, ML Janowiak, JE TI Sampling-induced conditional biases in satellite climate-scale rainfall estimates SO JOURNAL OF APPLIED METEOROLOGY LA English DT Article ID PROBABILITY-DISTRIBUTION FUNCTIONS; TIME STOCHASTIC-MODEL; TROPICAL RAINFALL; SPACE; PRECIPITATION; CLOUD; ALGORITHMS; ERRORS AB The effect of temporal sampling error in satellite estimates of climate-scale rainfall is to produce a ''conditional'' bias where the algorithm overestimates high rainfall and underestimates low rainfall. Thus, the bias is conditional on the value of the estimate. This paper illustrates the problem using satellite infrared rainfall estimates together with a well-known satellite algorithm and shows it to be a function of the averaging scale, the sampling rate, and the temporal autocorrelation structure of the satellite estimates. Using realistic sampling rates, it is shown that significant biases exist in satellite rainfall estimates if polar-orbiting data are used in their construction. A simple correction for this bias based upon the estimated autocorrelation structure is given. C1 NOAA,NWS,NATL METEOROL CTR,CLIMATE ANAL CTR,CAMP SPRINGS,MD. RP Morrissey, ML (reprint author), UNIV OKLAHOMA,OKLAHOMA CLIMATOL SURVEY,SARKEYS ENERGY CTR,SUITE 1210,100 E BOYD,NORMAN,OK 73019, USA. NR 31 TC 22 Z9 23 U1 0 U2 2 PU AMER METEOROLOGICAL SOC PI BOSTON PA 45 BEACON ST, BOSTON, MA 02108-3693 SN 0894-8763 J9 J APPL METEOROL JI J. Appl. Meteorol. PD APR PY 1996 VL 35 IS 4 BP 541 EP 548 DI 10.1175/1520-0450(1996)035<0541:SICBIS>2.0.CO;2 PG 8 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA UL926 UT WOS:A1996UL92600003 ER PT J AU Alduchov, OA Eskridge, RE AF Alduchov, OA Eskridge, RE TI Improved magnus form approximation of saturation vapor pressure SO JOURNAL OF APPLIED METEOROLOGY LA English DT Article ID HUMIDITY; EQUATIONS AB Algorithms, based on Magnus's form equations, are described that minimize the difference between several relationships between temperature and water vapor pressure at saturation that are commonly used in archiving data. The work was initiated in connection with the development of a unified upper-air dataset that will use measurements gathered from the late 1930s to the present and archived in several data centers. The conversion of field measurements to archived humidity values within the databases that are being used have not been consistent and in some cases are unknown. A goal of this work was to develop a uniform and accurate method to convert these data to various humidity variables without regard to the equations used in archiving the original data. Archived temperature values are recorded to 0.1 degrees C. This precision creates a temperature dependent range in uncertainty in saturation vapor pressure. A procedure was developed to take this into account when the error minimizing equations were derived. C1 NOAA,NATL CLIMAT DATA CTR,ASHEVILLE,NC 28801. NR 23 TC 90 Z9 91 U1 5 U2 16 PU AMER METEOROLOGICAL SOC PI BOSTON PA 45 BEACON ST, BOSTON, MA 02108-3693 SN 0894-8763 J9 J APPL METEOROL JI J. Appl. Meteorol. PD APR PY 1996 VL 35 IS 4 BP 601 EP 609 DI 10.1175/1520-0450(1996)035<0601:IMFAOS>2.0.CO;2 PG 9 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA UL926 UT WOS:A1996UL92600008 ER PT J AU Hucek, R Stowe, L Joyce, R AF Hucek, R Stowe, L Joyce, R TI Evaluating the design of an earth radiation budget instrument with system simulations .3. CERES-I diurnal sampling error SO JOURNAL OF ATMOSPHERIC AND OCEANIC TECHNOLOGY LA English DT Article ID OUTGOING LONGWAVE RADIATION; EXPERIMENT ERBE; VARIABILITY; CLOUD AB Accuracy estimates for the broadband CERES-I (Clouds and Earth's Radiant Energy System Instrument) measurements of daily average radiant exitance are presented. This is a continuation of the authors' earlier CERES sampling studies published as Parts I and II. Daily averaging errors result from not sampling the entire 24-h period with a system of polar satellites. Instantaneous errors, the subject of the previous studies, are also included. Separate estimates for daily average emitted longwave (LW) and reflected shortwave (SW) radiant fluxes are given. The earth SW and LW reference radiation fields are derived from 3-h Geosynchronous Operational Environmental Satellite data, time interpolated between image times, and partitioned into upwelling radiances using scene-dependent angular dependence models (ADMs). Perturbations in these ADMs are introduced to cause instantaneous angular sampling errors (also referred to as ADM errors). These ADM errors, along with spatial sampling errors, are propagated through the time integration process for a more realistic estimate of the daily average error. Three satellite observing configurations are considered. They represent individually, and in combination, a proposed European Polar Orbiting Platform and National Aeronautics and Space Administration Earth Observing System-A sun-synchronous polar-orbiting satellite system. The Earth Radiation Budget Experiment single and multiple satellite time and space averaging algorithms are used for the satellite retrieval. One-satellite spatial root-mean-square (rms) daily averaged SW flux errors of 11-17 W m(-2) are obtained for 2.5 degrees latitude-longitude regions over the area studied (15 degrees S-45 degrees N, 50 degrees-120 degrees W),The two-satellite system has errors that are some 40%-60% less, having values between 5 and 9 W m(-2). Only the two-satellite system can meet the 10 W m(-2) user accuracy requirement for regional daily averaged SW fluxes. Longwave flux errors of 5-6 W m(-2) and 3-4 W m(-2), respectively, are found for the one- and two-satellite configurations. The largest component of CERES 2.5 degrees daily averaged target area error is due to sparse temporal sampling. The ADM error propagated into the daily average becomes more important as the temporal sampling error is reduced with the two-satellite system. For this system, the ADM error component (of the daily averaged error) for SW radiation reaches a magnitude that can be as large as 8 W m(-2) at high solar zenith angles (SZA), where scene anisotropy is usually greatest. Over the study domain, up to 15% of the total rms error is due to ADM errors. Moreover, CERES 2.5 degrees zonal mean daily averaged errors exhibit a latitudinal dependence of some 7 W m(-2) for a 60 degrees change in latitude in the presence of 30% systematic errors in the ADMs. This is largely attributable to the SZA dependence of instantaneous ADM error. Without ADM errors, zonal mean daily averaged target area biases range up to 3-4 W m(-2) with an irregular latitudinal variation. C1 NOAA,NATL ENVIRONM SATELLITE DATA & INFORMAT SERV,ASB,WASHINGTON,DC 20233. RES & DATA SYST CORP,GREENBELT,MD. NR 25 TC 3 Z9 3 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 APR PY 1996 VL 13 IS 2 BP 383 EP 399 DI 10.1175/1520-0426(1996)013<0383:ETDOAE>2.0.CO;2 PG 17 WC Engineering, Ocean; Meteorology & Atmospheric Sciences SC Engineering; Meteorology & Atmospheric Sciences GA UG675 UT WOS:A1996UG67500011 ER PT J AU Zrnic, DS Ryzhkov, A AF Zrnic, DS Ryzhkov, A TI Advantages of rain measurements using specific differential phase SO JOURNAL OF ATMOSPHERIC AND OCEANIC TECHNOLOGY LA English DT Article ID RADAR MEASUREMENTS; SHIFT; PRECIPITATION AB The following advantages of rain measurements using specific differential phase are examined: 1) immunity to beam blockage, 2) immunity to ground clutter canceling, and 3) ease to isolate effects of anomalous propagation. We quantify immunity to beam blockage via examples of measurements that corroborate theoretical expectations. Comparisons of rain accumulations between radar and rain gauges are included. We also contrast beam-filling effects on rain estimates from reflectivity and specific differential phase. RP Zrnic, DS (reprint author), NOAA,ENVIRONM RES LAB,NATL SEVERE STORMS LAB,1313 HALLEY CIRCLE,NORMAN,OK 73069, USA. NR 23 TC 108 Z9 118 U1 0 U2 5 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 APR PY 1996 VL 13 IS 2 BP 454 EP 464 DI 10.1175/1520-0426(1996)013<0454:AORMUS>2.0.CO;2 PG 11 WC Engineering, Ocean; Meteorology & Atmospheric Sciences SC Engineering; Meteorology & Atmospheric Sciences GA UG675 UT WOS:A1996UG67500016 ER PT J AU Yamanaka, MD Ogino, S Kondo, S Shimomai, T Fukao, S Shibagaki, Y Maekawa, Y Takayabu, I AF Yamanaka, MD Ogino, S Kondo, S Shimomai, T Fukao, S Shibagaki, Y Maekawa, Y Takayabu, I TI Inertio-gravity waves and subtropical multiple tropopauses: Vertical wavenumber spectra of wind and temperature observed by the MU radar, radiosondes and operational rawinsonde network SO JOURNAL OF ATMOSPHERIC AND TERRESTRIAL PHYSICS LA English DT Article; Proceedings Paper CT Symposium and Workshop on Ionosphere - Middle and Lower Atmosphere Interaction, at the XXIVth General Assembly of the International-Union-of-Radio-Science CY AUG 25-SEP 02, 1993 CL KYOTO, JAPAN SP Int Union Radio Sci ID ATMOSPHERIC VELOCITY FLUCTUATIONS; MIDDLE ATMOSPHERE; LOWER STRATOSPHERE; VHF RADAR; JET-STREAM; MESOSCALE VARIABILITY; GENERAL-CIRCULATION; UNIVERSAL SPECTRUM; CRITICAL LAYER; TURBULENCE AB We have carried out continuous observations of the tropopause region over Japan for three weeks during the Baiu (early summer rain ''in Japan'') season in 1991, by using a VHF Doppler radar (the MU radar), radiosondes launched at the radar site and operational rawinsondes at five meteorological stations. Based on these observations, we try to examine the hypothesis that the multiple tropopauses and the dominant inertio-gravity waves are one and the same feature, and obtain some interesting results that are not inconsistent with this hypothesis. First, vertical wavenumber spectra and hodographs analyzed from the radar wind data in the tropopause region suggest that inertio-gravity waves with vertical wavelengths of similar to 2 km are quasi-monochromatically dominant (with 2-3 day scale variabilities of 10-20%), and are in accordance with activities of the subtropical jet stream and mesoscale cyclone-front system activities observed by the operational network. Second, striking (potential) temperature fluctuations are detected simultaneously by the radiosondes and rawinsondes, which appear as multiple tropopauses in meridional cross-section analysis. Third, vertical wavenumber spectra analyzed from the radiosonde temperature data are consistent with the radar wind spectrum, if we assume that both wind and temperature fluctuations are mainly induced by the dominant inertio-gravity waves. Finally, we confirm that the dominant inertio-gravity waves can be barely detected also from routine rawinsonde (1.5-km running-mean) wind data if the amplitude is larger than 1.5 m/s. However, the monochromatic wave structures are generally quite localized in space and time. C1 OSAKA ELECTROCOMMUN UNIV, NEYAGAWA, OSAKA 572, JAPAN. NOAA, NATL METEOROL CTR, WASHINGTON, DC 20233 USA. RP Yamanaka, MD (reprint author), KYOTO UNIV, CTR RADIO ATMOSPHER SCI, UJI, KYOTO 611, JAPAN. RI Yamanaka, Manabu/E-5671-2011 NR 135 TC 24 Z9 25 U1 0 U2 5 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLAND SN 0021-9169 J9 J ATMOS TERR PHYS JI J. Atmos. Terr. Phys. PD APR PY 1996 VL 58 IS 6 BP 785 EP 805 DI 10.1016/0021-9169(95)00074-7 PG 21 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA TY362 UT WOS:A1996TY36200013 ER PT J AU Sun, DZ Held, IM AF Sun, DZ Held, IM TI A comparison of modeled and observed relationships between interannual variations of water vapor and temperature SO JOURNAL OF CLIMATE LA English DT Article ID CLIMATE; FEEDBACK AB The correlations between interannual variations of tropical mean water vapor and temperature in the simulations by a low resolution (R15) GCM are stronger than those in the rawinsonde observations. The rate of fractional increase of tropical mean water vapor with temperature in the model simulations is also larger than that from the observations. The largest discrepancies are found in the region immediately above the tropical convective boundary layer (850-600 mb). The rate of fractional increase of tropical mean water vapor with temperature in the model simulations is close to that for a constant relative humidity. The correlations between variations of water vapor in the upper troposphere and those in the lower troposphere are also stronger in the model simulations than in the observations. In the horizontal, the characteristic spatial patterns of the normalized water vapor variations in the model simulations and observations are similar. The water vapor-temperature relationship in simulations by a GCM with a somewhat higher spatial resolution (R30) is almost identical to that in the simulations by the low resolution (R15) GCM. The implications of these findings or the radiative feedback of water vapor are discussed. C1 PRINCETON UNIV,PROGRAM ATMOSPHER & OCEAN SCI,PRINCETON,NJ 08544. PRINCETON UNIV,NOAA,GEOPHYS FLUID DYNAM LAB,PRINCETON,NJ 08542. RP Sun, DZ (reprint author), NATL CTR ATMOSPHER RES,POB 3000,BOULDER,CO 80307, USA. NR 18 TC 65 Z9 65 U1 0 U2 2 PU AMER METEOROLOGICAL SOC PI BOSTON PA 45 BEACON ST, BOSTON, MA 02108-3693 SN 0894-8755 J9 J CLIMATE JI J. Clim. PD APR PY 1996 VL 9 IS 4 BP 665 EP 675 DI 10.1175/1520-0442(1996)009<0665:ACOMAO>2.0.CO;2 PG 11 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA UJ643 UT WOS:A1996UJ64300001 ER PT J AU Huang, J VandenDool, HM Barnston, AG AF Huang, J VandenDool, HM Barnston, AG TI Long-lead seasonal temperature prediction using optimal climate normals SO JOURNAL OF CLIMATE LA English DT Article ID RANGE PREDICTION; VERIFICATION; MODEL AB This study is intended to determine the spatially varying optimal time periods for calculating seasonal climate normals over the entire United States based on temperature data at 344 United States climate divisions during the period of 1931-1993. This is done by verifying the seasonal climate normals as a forecast for the same season next year. The forecast skill is measured by the correlation between the predicted and observed anomalies relative to the 30-yr normal. The optimal time periods are chosen to produce the highest correlation between the forecasts and the observation. The results indicate that generally (all seasons and all locations) annually updated climate normals averaged over shorter than 30-yr periods are better than the WMO specified 30-yr normal (updated only every 10 years), in terms of the skill in predicting the upcoming year. The spatial pattern of the optimal averaging time periods changes with season. The skill of optimal normals comes from both the annual updating and the shorter averaging time periods of these normals. Using optimal climate normals turns out to be a reasonably successful forecast method. Utility is further enhanced by realizing that the lead time of this forecast is almost one year. Forecasts at leads beyond one year (skipping a year) are also reasonably skillful. The skill obtained from the dependent verification is lowered to take account of the degradation expected on independent data. In practice the optimal climate normals with a variable averaging period were found to be somewhat problematic. The problems had to do primarily with the temporal continuity and spatial consistency of the forecasts. For the time being, a constant time period of 10 years is used in the operational seasonal temperature forecasts for all seasons and locations. C1 NATL CTR ENVIRONM PREDICT,CLIMATE CTR,WASHINGTON,DC 20233. NR 18 TC 54 Z9 56 U1 0 U2 3 PU AMER METEOROLOGICAL SOC PI BOSTON PA 45 BEACON ST, BOSTON, MA 02108-3693 SN 0894-8755 J9 J CLIMATE JI J. Clim. PD APR PY 1996 VL 9 IS 4 BP 809 EP 817 DI 10.1175/1520-0442(1996)009<0809:LLSTPU>2.0.CO;2 PG 9 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA UJ643 UT WOS:A1996UJ64300008 ER PT J AU Xie, PP Arkin, PA AF Xie, PP Arkin, PA TI Analyses of global monthly precipitation using gauge observations, satellite estimates, and numerical model predictions SO JOURNAL OF CLIMATE LA English DT Article ID PROBABILITY-DISTRIBUTION FUNCTIONS; SURROUNDING WATERS; TROPICAL RAINFALL; SCALE; MICROWAVE; CLOUD; FORECASTS; JAPAN; RADAR; COVER AB An algorithm is developed to construct global gridded fields of monthly precipitation by merging estimates from five sources of information with different characteristics, including gauge-based monthly analyses from the Global Precipitation Climatology Centre, three types of satellite estimates [the infrared-based GOES Precipitation Index, the microwave (MW) scattering-based Grody, and the MW emission-based Chang estimates], and predictions produced by the operational forecast model of the European Centre for Medium-Range Weather Forecasts. A two-step strategy is used to: 1) reduce the random error found in the individual sources and 2) reduce the bias of the combined analysis. First, the three satellite-based estimates and the model predictions are combined linearly based on a maximum likelihood estimate, in which the weighting coefficients are inversely proportional to the squares of the individual random errors determined by comparison with gauge observations and subjective assumptions. This combined analysis is then blended with an analysis based on gauge observations using a method that presumes that the bias of the gauge-based field is small where sufficient gauges are available and that the gradient of the precipitation field is best represented by the combination of satellite estimates and model predictions elsewhere. The algorithm is applied to produce monthly precipitation analyses for an 18-month period from July 1987 to December 1988. Results showed substantial improvements of the merged analysis relative to the individual sources in describing the global precipitation field. The large-scale spatial patterns, both in the Tropics and the extratropics, are well represented with reasonable amplitudes. Both the random error and the bias have been reduced compared to the individual data sources, and the merged analysis appears to be of reasonable quality everywhere. However, the actual quality of the merged analysis depends strongly on our uncertain and incomplete knowledge of the error structures of the individual data sources. RP Xie, PP (reprint author), NOAA,NATL WEATHER SERV,NATL CTR ENVIRONM PREDICT,WASHINGTON,DC 20233, USA. RI Arkin, Phillip/F-5808-2010 NR 46 TC 948 Z9 987 U1 9 U2 50 PU AMER METEOROLOGICAL SOC PI BOSTON PA 45 BEACON ST, BOSTON, MA 02108-3693 SN 0894-8755 J9 J CLIMATE JI J. Clim. PD APR PY 1996 VL 9 IS 4 BP 840 EP 858 DI 10.1175/1520-0442(1996)009<0840:AOGMPU>2.0.CO;2 PG 19 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA UJ643 UT WOS:A1996UJ64300011 ER PT J AU Zhai, PM Eskridge, RE AF Zhai, PM Eskridge, RE TI Analyses of inhomogeneities in radiosonde temperature and humidity time series SO JOURNAL OF CLIMATE LA English DT Article AB Twice daily radiosonde data from selected stations in the United States (period 1948 to 1990) and China (period 1958 to 1990) were sorted into time series. These stations have one sounding taken in darkness and the other in sunlight. The analysis shows that the 0000 and 1200 UTC time series are highly correlated. Therefore, the Easterling and Peterson technique was tested on the 0000 and 1200 time series to detect inhomogeneities and to estimate the size of the biases. Discontinuities were detected using the difference series created from the 0000 and 1200 UTC time series. To establish that the detected bias was significant, a t test was performed to confirm that the change occurs in the daytime series but not in the nighttime series. Both U.S. and Chinese radiosonde temperature and humidity data include inhomogeneities caused by changes in radiosonde sensors and observation times. The U.S. humidity data have inhomogeneities that were caused by instrument changes and the censoring of data. The practice of reporting relative humidity as 19% when it is lower than 20% or the temperature is below -40 degrees C is called censoring. This combination of procedural and instrument changes makes the detection of biases and adjustment of the data very difficult. In the Chinese temperatures, there are inhomogeneities related to a change in the radiation correction procedure. Test results demonstrate that a modified Easterling and Peterson method is suitable for use in detecting and adjusting time series radiosonde data. Accurate stations histories are very desirable. Stations histories can confirm that detected inhomogeneities are related to instrument or procedural changes. Adjustments can then be made to the data with some confidence. C1 NOAA,NATL CLIMAT DATA CTR,NATL ENVIRONM SATELLITE DATA & INFORMAT SERV,ASHEVILLE,NC 28801. NR 21 TC 33 Z9 47 U1 2 U2 3 PU AMER METEOROLOGICAL SOC PI BOSTON PA 45 BEACON ST, BOSTON, MA 02108-3693 SN 0894-8755 J9 J CLIMATE JI J. Clim. PD APR PY 1996 VL 9 IS 4 BP 884 EP 894 DI 10.1175/1520-0442(1996)009<0884:AOIIRT>2.0.CO;2 PG 11 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA UJ643 UT WOS:A1996UJ64300013 ER PT J AU Zwart, A vanAssendelft, OW Bull, BS Lewis, SM Zijlstra, WG AF Zwart, A vanAssendelft, OW Bull, BS Lewis, SM Zijlstra, WG TI Recommendations for reference method for haemoglobinometry in human blood (ICSH standard 1995) and specifications for international haemiglobincyanide standard (4th edition) SO JOURNAL OF CLINICAL PATHOLOGY LA English DT Article ID PERCHLORIC-ACID; HOLMIUM OXIDE; HEMOGLOBIN; HEMIGLOBINCYANIDE; CALIBRATION C1 NCID,CTR DIS CONTROL & PREVENT,SCI RESOURCES PROGRAM,ATLANTA,GA. NATL INST STAND & TECHNOL,LAB COLL AMER PATHOLOGISTS,GAITHERSBURG,MD 20899. UNIV GRONINGEN,FAC MED,GRONINGEN,NETHERLANDS. LOMA LINDA UNIV,SCH MED,LOMA LINDA,CA. ROYAL POSTGRAD MED SCH,LONDON,ENGLAND. INST SUPER SANITA,ROME,ITALY. NR 36 TC 105 Z9 115 U1 1 U2 9 PU BRITISH MED JOURNAL PUBL GROUP PI LONDON PA BRITISH MED ASSOC HOUSE, TAVISTOCK SQUARE, LONDON, ENGLAND WC1H 9JR SN 0021-9746 J9 J CLIN PATHOL JI J. Clin. Pathol. PD APR PY 1996 VL 49 IS 4 BP 271 EP 274 DI 10.1136/jcp.49.4.271 PG 4 WC Pathology SC Pathology GA UG228 UT WOS:A1996UG22800001 PM 8655699 ER PT J AU Nguyen, T Hubbard, JB Pommersheim, JM AF Nguyen, T Hubbard, JB Pommersheim, JM TI Unified model for the degradation of organic coatings on steel in a neutral electrolyte SO JOURNAL OF COATINGS TECHNOLOGY LA English DT Article ID ACRYLIC MELAMINE COATINGS; CATHODIC DELAMINATION; SODIUM-CHLORIDE; POLYMER-FILMS; COATED STEEL; CORROSION; INTERFACE; MECHANISM; METALS; PROTECTION AB A unified model is presented for the degradation of an organic protective coating on a steel substrate exposed to a neutral electrolytic environment. This model is based on theoretical and experimental studies from our laboratory and on current understanding of the degradation process. The assumptions of the model are based on the concept that degradation of a coating/steel system occurs following the transport of ions through conductive pathways, which are presumably formed by an attack by water in the ''hydrophylic,'' low-molecular-weight/low-cross-linked regions, followed by the connections of these regions. Models for the blistering and delamination resulting from corrosion processes are based on the diffusion of cations along the coating/steel interface from the defects to cathodic sites under the coatings. The resulting equations are solved to predict ion fluxes and concentration profiles along the interface and within blisters. Model variables include blister size, distance between blister and defect, ion diffusivity, and potential gradients. Experimental results agree well with theoretical predictions. C1 BUCKNELL UNIV,DEPT CHEM ENGN,LEWISBURG,PA 17837. RP Nguyen, T (reprint author), NATL INST STAND & TECHNOL,GAITHERSBURG,MD 20899, USA. NR 84 TC 84 Z9 89 U1 2 U2 17 PU FEDERATION SOC COATING TECH PI BLUE BELL PA 492 NORRISTOWN ROAD, BLUE BELL, PA 19422 SN 0361-8773 J9 J COATING TECHNOL JI J. Coat. Technol. PD APR PY 1996 VL 68 IS 855 BP 45 EP 56 PG 12 WC Chemistry, Applied; Materials Science, Coatings & Films SC Chemistry; Materials Science GA UJ047 UT WOS:A1996UJ04700014 ER PT J AU Ryer, CH Olla, BL AF Ryer, CH Olla, BL TI Growth depensation and aggression in laboratory reared coho salmon: The effect of food distribution and ration size SO JOURNAL OF FISH BIOLOGY LA English DT Article DE Oncorhynchus kisutch; growth depensation; growth variation; dominance; aggression; food distribution ID AGONISTIC BEHAVIOR; ATLANTIC SALMON; SALAR L; FISH; VARIABILITY; POPULATIONS; JUVENILES; TROUT AB Groups of recently emerged coho salmon fry Oncorhynchus kisutch were reared for 3 months on food that appeared either asynchronously at a single location (localized) or synchronously and spatially dispersed (dispersed). Groups were further subdivided into those receiving low (1%) or high (3% body weight per day) rations, with five replicate groups for each treatment combination. At low ration there was greater growth depensation, i.e. growth variation, in groups receiving localized as compared to dispersed food. At high ration there was no difference. There was no effect of food distribution upon mean fish weight, but groups receiving high rations had greater mean fish weights than groups receiving low rations. There was no overall difference in the frequency of chasing between any of the treatment combinations. However, in localized food groups, dominants defended positions close to where food entered the tank, giving them greater access than subordinates. In dispersed food groups, while dominants also defended particular areas, this did not result in greater access to food. These results demonstrate that although feeding methodology may not directly influence the frequency of aggressive interactions, Feeding methods which facilitate feud monopolization by dominants can accelerate the growth of these individuals at the expense of subordinates. In aquacultural applications where greater size is desirable, or otherwise selected for, this may result in the unintentional selection fur increased aggressiveness. (C) 1996 The Fisheries Society of the British Isles RP Ryer, CH (reprint author), NOAA,HATFIELD MARINE SCI CTR,NATL MARINE FISHERIES SERV,ALASKA FISHERIES SCI CTR,NEWPORT,OR 97365, USA. NR 21 TC 68 Z9 70 U1 1 U2 5 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 APR PY 1996 VL 48 IS 4 BP 686 EP 694 DI 10.1006/jfbi.1996.0069 PG 9 WC Fisheries; Marine & Freshwater Biology SC Fisheries; Marine & Freshwater Biology GA UK347 UT WOS:A1996UK34700013 ER PT J AU Maynard, NC Burke, WJ Basinska, EM Erickson, GM Hughes, WJ Singer, HJ Yahnin, AG Hardy, DA Mozer, FS AF Maynard, NC Burke, WJ Basinska, EM Erickson, GM Hughes, WJ Singer, HJ Yahnin, AG Hardy, DA Mozer, FS TI Dynamics of the inner magnetosphere near times of substorm onsets SO JOURNAL OF GEOPHYSICAL RESEARCH-SPACE PHYSICS LA English DT Article ID WESTWARD TRAVELING SURGE; FIELD-ALIGNED CURRENTS; ELECTRIC-FIELDS; MAGNETIC-FIELD; PLASMA SHEET; HARANG DISCONTINUITY; GROWTH-PHASE; AURORAL-ZONE; MODEL; MAGNETOTAIL AB The electrodynamics of the inner magnetosphere near times of substorm onsets have been investigated using CRRES measurements of magnetic and electric fields, energetic electron fluxes, in conjunction with ground-based observations. Six events were studied in detail, spanning the 2100 to 0000 MLT sector and L values from 5 to 7. In each case the dawn-dusk electric field was enhanced over typical background electric fields, and significant, low-frequency pulsation activity was observed. The amplitudes of the pulsations were larger than the background electric fields. Dusk-dawn excursions of the cross-tail electric field often correlated with changes in currents and particle energies at CRRES and with ULF wave activity observed on the ground. Variations of the electric field and Poynting vectors with periods in the Pi 2 range are consistent with bouncing Alfven waves that provide electromagnetic communication between the ionosphere and plasma sheet. Magnetic signatures of field-aligned current filaments directed away from the ionosphere, presumably associated with the substorm current wedge, were observed during three orbits. In all cases, ground signatures of substorm expansion were observed at least 5 min before the injection of electrons at CRRES. Field-aligned fluxes of counter-streaming, low-energy electrons were detected after three of the injections. We develop an empirical scenario for substorm onset. The process grows from ripples at the inner edge of the plasma sheet associated with dusk-dawn excursions of the electric field, prior to the beginning of dipolarization. Energy derived from the braking of the inward plasma convection flows into the ionosphere in the form of Poynting flux. Subsequently reflected Poynting flux plays a crucial role in the magnetosphere-ionosphere coupling. Substorms develop when significant energy (positive feedback?) hows in both directions, with the second cycle stronger than the initial. Pseudobreakups occur when energy flow in both directions is weak (negative feedback?). ''Explosive-growth-phase'' signatures occur after onset, early in the substorm expansion phase. Heated electrons arrive at the spacecraft while convection is earthward, during or at the end of electromagnetic energy flow away from the ionosphere. C1 BOSTON UNIV,CTR SPACE PHYS,BOSTON,MA 02215. PHILLIPS LAB,BEDFORD,MA 01731. UNIV CALIF BERKELEY,SPACE SCI LAB,BERKELEY,CA 94720. NOAA,SPACE ENVIRONM LAB,BOULDER,CO 80303. POLAR GEOPHYS INST,APATITY 184200,RUSSIA. RP Maynard, NC (reprint author), MISSION RES CORP,1 TARA BLVD,SUITE 302,NASHUA,NH 03062, USA. RI Yahnin, Alexander/B-5254-2014 OI Yahnin, Alexander/0000-0003-1650-5436 NR 64 TC 110 Z9 111 U1 1 U2 7 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 APR 1 PY 1996 VL 101 IS A4 BP 7705 EP 7736 DI 10.1029/95JA03856 PG 32 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA UD939 UT WOS:A1996UD93900010 ER PT J AU Rao, CN Reddy, P Liu, YY Reeder, DJ Foster, DC Kisiel, W Woodley, DT AF Rao, CN Reddy, P Liu, YY Reeder, DJ Foster, DC Kisiel, W Woodley, DT TI Skin matrix-associated novel serine protease inhibitors are products of a single gene with differential glycosylation: Characterization of a full length cDNA. SO JOURNAL OF INVESTIGATIVE DERMATOLOGY LA English DT Meeting Abstract C1 NORTHWESTERN UNIV,DEPT DERMATOL,CHICAGO,IL. NIST,BIOTECH UNIT,BOULDER,CO. UNIV NEW MEXICO,ALBUQUERQUE,NM 87131. NR 0 TC 0 Z9 0 U1 0 U2 0 PU BLACKWELL SCIENCE INC PI CAMBRIDGE PA 238 MAIN ST, CAMBRIDGE, MA 02142 SN 0022-202X J9 J INVEST DERMATOL JI J. Invest. Dermatol. PD APR PY 1996 VL 106 IS 4 BP 103 EP 103 PG 1 WC Dermatology SC Dermatology GA UC787 UT WOS:A1996UC78700145 ER PT J AU Rao, CN Liu, YV Reddy, P Reeder, DJ Kisiel, W Woodley, DT AF Rao, CN Liu, YV Reddy, P Reeder, DJ Kisiel, W Woodley, DT TI Conformation, but not glycosylation, is required for the anti-protease activity of newly identified extracellular matrix-associated 33 KDA inhibitor. SO JOURNAL OF INVESTIGATIVE DERMATOLOGY LA English DT Meeting Abstract C1 NORTHWESTERN UNIV,DEPT DERMATOL,CHICAGO,IL 60611. NIST,GAITHERSBURG,MD 20899. UNIV NEW MEXICO,DEPT PATHOL,ALBUQUERQUE,NM 87131. NR 0 TC 0 Z9 0 U1 0 U2 0 PU BLACKWELL SCIENCE INC PI CAMBRIDGE PA 238 MAIN ST, CAMBRIDGE, MA 02142 SN 0022-202X J9 J INVEST DERMATOL JI J. Invest. Dermatol. PD APR PY 1996 VL 106 IS 4 BP 544 EP 544 PG 1 WC Dermatology SC Dermatology GA UC787 UT WOS:A1996UC78700585 ER PT J AU Wang, JL Tsu, IF Cai, XY Kelley, RJ Vaudin, MD Babcock, SE Larbalestier, DC AF Wang, JL Tsu, IF Cai, XY Kelley, RJ Vaudin, MD Babcock, SE Larbalestier, DC TI Electromagnetic and microstructural investigations of a naturally grown 8 degrees [001] tilt bicrystal of Bi2Sr2CaCu2O8+x SO JOURNAL OF MATERIALS RESEARCH LA English DT Article ID SUPERCONDUCTING TRANSPORT-PROPERTIES; YBA2CU3O7-DELTA GRAIN-BOUNDARIES; SINGLE-CRYSTALS; CRITICAL CURRENTS; DC SQUIDS; CU-O; JUNCTIONS; TAPES; BEHAVIOR; MODEL AB Electromagnetic characterization and high resolution transmission electron microscopy have been conducted on the same 8 degrees [001] symmetrical (010) tilt boundary in a naturally grown, bulk-scale bicrystal of Bi2Sr2CaCu2O8+x (BSCCO-2212). The resistive transition showed excess resistance above and below T-c, suggesting some weak coupling at the boundary, but the inter- and intragranular voltage-current characteristics, irreversibility fields, and critical current density (J(c)) values were very similar and characteristic of strongly coupled grains and grain boundary. The misorientation was accommodated by a set of partial dislocations with the Frank spacing of 1.9 nm. The dislocation cores appeared to be separated by relatively undistorted regions of crystal. The J(c) values at 25 K exceeded 10(3) A/cm(2) in fields of several tesla, more than two orders of magnitude larger than that found earlier in [001] twist boundaries of BSCCO-2212. This result is consistent with the view that low angle [001] tilt boundaries play an important role for current transport in polycrystalline BSCCO tapes. C1 UNIV WISCONSIN,DEPT PHYS,CTR APPL SUPERCONDUCT,MADISON,WI 53706. NIST,DIV CERAM,GAITHERSBURG,MD 20899. RP Wang, JL (reprint author), UNIV WISCONSIN,MAT SCI PROGRAM,CTR APPL SUPERCONDUCT,DEPT MAT SCI & ENGN,MADISON,WI 53706, USA. RI Larbalestier, David/B-2277-2008 OI Larbalestier, David/0000-0001-7098-7208 NR 43 TC 16 Z9 16 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 APR PY 1996 VL 11 IS 4 BP 868 EP 877 DI 10.1557/JMR.1996.0108 PG 10 WC Materials Science, Multidisciplinary SC Materials Science GA UE459 UT WOS:A1996UE45900015 ER PT J AU Wei, LH Lawn, BR AF Wei, LH Lawn, BR TI Thermal wave analysis of contact damage in ceramics: Case study on alumina SO JOURNAL OF MATERIALS RESEARCH LA English DT Article ID CRACKS AB Thermal waves are used to image damage accumulation digitally beneath Hertzian contacts in ceramics. Alumina ceramics over a range of grain size 3-48 mu m are used in a case study. The nature of the images changes with increasing alumina grain size, reflecting a transition in damage mode from well-defined cone fracture in the finer-grain materials to distributed subsurface microfracture in the coarser-grain materials. Quantitative determinations of microcrack densities are evaluated in the latter case by deconvoluting thermal diffusivities from the image data. These determinations confirm the grain-size dependence of degree of damage predicted by fracture mechanics models. Potential advantages and disadvantages of thermal waves as a route to damage characterization in ceramic systems are discussed. RP NATL INST STAND & TECHNOL, MAT SCI & ENGN LAB, GAITHERSBURG, MD 20899 USA. NR 29 TC 9 Z9 9 U1 0 U2 0 PU CAMBRIDGE UNIV PRESS PI NEW YORK PA 32 AVENUE OF THE AMERICAS, NEW YORK, NY 10013-2473 USA SN 0884-2914 EI 2044-5326 J9 J MATER RES JI J. Mater. Res. PD APR PY 1996 VL 11 IS 4 BP 939 EP 947 DI 10.1557/JMR.1996.0118 PG 9 WC Materials Science, Multidisciplinary SC Materials Science GA UE459 UT WOS:A1996UE45900025 ER PT J AU Lafferty, WJ Pine, AS Hilpert, G Sams, RL Flaud, JM AF Lafferty, WJ Pine, AS Hilpert, G Sams, RL Flaud, JM TI The nu(1)+nu(3) and 2 nu(1)+nu(3) band systems of SO2: Line positions and intensities SO JOURNAL OF MOLECULAR SPECTROSCOPY LA English DT Article ID (SO2)-S-32-O-16; SPECTROSCOPY; SPECTRUM AB The room temperature infrared spectra of the a-type nu(1) + nu(3), nu(1) + nu(2) + nu(3) - nu(2), and 2 nu(1) + nu(3) bands of (SO2)-S-32 and the nu(1) + nu(3) band of (SO2)-S-34 have been recorded using a difference-frequency laser spectrometer and completely analyzed. It is possible to reproduce the rotational energy levels for the (201) and (111) vibrational states using a single Watson-type Hamiltonian, but it is necessary to consider the weak Fermi-type interaction coupling the rotational energy levels of the (101) state with those of the (021) vibrational state in order to fit the energy levels of (101). The band centers, nu(0)(101), nu(0)(111), and nu(0)(201), were determined to be 2499.87003(20), 3010.31730(20), and 3629.76194(30) cm(-1) respectively, where the uncertainty cited includes an estimate of the uncertainty in the wavenumber calibration. For the (SO2)-S-34 isotopic species, nu(0)(101) was found to be 2475.82917(57) cm(-1). A complete set of rotational and centrifugal distortion constants was obtained for each state. In addition, precise line intensities were determined for each band yielding improved band transition moments. The integrated band intensities at 296 K have been found to be S-upsilon(nu(1) + nu(3)) = 0.539(23) X 10(-18), S-upsilon(nu(1) + nu(2) + nu(3) - nu(2)) = 0.425(18) x 10(-19), and S-upsilon(2 nu(1) + nu(3)) = 0.607(25) X 10(-20) cm(-1)/ (molecule cm(-2)). The total integrated intensity of the nu(1) + nu(3) band system was also determined at 0.11 cm(-1) resolution from dilute mixtures of SO2 in N-2 at atmospheric pressure. The value of S-upsilon(nu(1) + nu(3)) determined from this technique was 0.537(16) x 10(-18) cm(-1)/(molecule cm(-2)), in excellent agreement with the high resolution method. The uncertainties in parentheses are estimated experimental errors. (C) 1996 Academic Press, Inc. C1 NATL INST STAND & TECHNOL,DIV ANALYT CHEM,GAITHERSBURG,MD 20899. UNIV PARIS 06,CNRS,LPMA,F-75252 PARIS 05,FRANCE. RP Lafferty, WJ (reprint author), NATL INST STAND & TECHNOL,DIV MOLEC PHYS,GAITHERSBURG,MD 20899, USA. NR 20 TC 32 Z9 34 U1 0 U2 8 PU ACADEMIC PRESS INC JNL-COMP SUBSCRIPTIONS PI SAN DIEGO PA 525 B ST, STE 1900, SAN DIEGO, CA 92101-4495 SN 0022-2852 J9 J MOL SPECTROSC JI J. Mol. Spectrosc. PD APR PY 1996 VL 176 IS 2 BP 280 EP 286 DI 10.1006/jmsp.1996.0088 PG 7 WC Physics, Atomic, Molecular & Chemical; Spectroscopy SC Physics; Spectroscopy GA UK885 UT WOS:A1996UK88500007 ER PT J AU Bolcavage, A Kattner, UR AF Bolcavage, A Kattner, UR TI A reassessment of the calculated Ni-Nb phase diagram SO JOURNAL OF PHASE EQUILIBRIA LA English DT Article AB A revised calculation of the Ni-Nb (nickel-niobium) phase diagram includes realistic enthalpy of formation values for the intermetallic phases that compare with experimental values, a more accurate crystallographic description of the mu phase, and a better fit to the experimentally determined invariant equilibrium temperatures and liquidus-solidus boundaries between liquid and (Ni), The set of parameters describing the Gibbs energy of each phase is given. C1 NIST,DIV MET,GAITHERSBURG,MD 20899. UNIV WISCONSIN,DEPT MAT SCI & ENGN,MADISON,WI 53706. NR 44 TC 40 Z9 41 U1 2 U2 6 PU ASM INTERNATIONAL PI MATERIALS PARK PA SUBSCRIPTIONS SPECIALIST CUSTOMER SERVICE, MATERIALS PARK, OH 44073-0002 SN 1054-9714 J9 J PHASE EQUILIB JI J. Phase Equilib. PD APR PY 1996 VL 17 IS 2 BP 92 EP 100 DI 10.1007/BF02665782 PG 9 WC Chemistry, Physical; Materials Science, Multidisciplinary; Metallurgy & Metallurgical Engineering SC Chemistry; Materials Science; Metallurgy & Metallurgical Engineering GA UD652 UT WOS:A1996UD65200003 ER PT J AU Udovic, TJ Huang, Q Rush, JJ AF Udovic, TJ Huang, Q Rush, JJ TI Characterization of the structure of YD3 by neutron powder diffraction SO JOURNAL OF PHYSICS AND CHEMISTRY OF SOLIDS LA English DT Article DE alloys; inorganic compounds; metals; neutron scattering; crystal structure ID SOLID-SOLUTIONS; YTTRIUM; HYDROGEN; DEUTERIUM; METAL; RANGE AB Neutron-powder-diffraction (NPD) measurements of the hexagonal rare-earth trideuteride gamma-YD3 were undertaken between 10 and 400K. Rietveld refinements indicated that the YD3 structure possesses (D-3d(4)) symmetry, in agreement with previous NPD studies of YD3 and HoD3. The unit cell is a (root 3 x root 3)R30 degrees expansion of the conventional hcp unit cell in the ab plane. To accomodate the D atoms, the c axis for YD3 is elongated by similar to 15% [c(0)/a(0) = 1.8019(1), a(0) = 3.6627(1) Angstrom, at 295 K] compared with that for Y. The D atoms occupy unusual interstitial positions of a slightly distorted, hcp metal lattice, instead of the ideal octahedral (o) and tetrahedral (t) sites. In particular, the hypothetical o-site D atoms are displaced vertically toward the Y-defined basal planes, with correlated placements at either near-plane or in-plane threefold metal (m) sites. The t-site D (D-t) atoms are displaced horizontally, also in a correlated fashion, with respect to the m-site D (D-m) atoms. This structure is maintained over the entire temperature range from 10 to 400 K. Moreover, the data suggest the presence of an order-disorder equilibrium amongst the D-m atoms. The disorder involves c-axis displacements of a fraction of D-m atoms from near-plane to in-plane positions, concomitant with an equal number of compensating D-m atoms shifting from in-plane to near-plane positions. The displacements are facilitated by the relatively open channels formed along the c direction by the Y and D-t atoms. C1 UNIV MARYLAND,DEPT MAT & NUCL ENGN,COLLEGE PK,MD 20742. RP Udovic, TJ (reprint author), NATL INST STAND & TECHNOL,MAT SCI & ENGN LAB,GAITHERSBURG,MD 20899, USA. NR 20 TC 65 Z9 65 U1 1 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 APR PY 1996 VL 57 IS 4 BP 423 EP 435 DI 10.1016/0022-3697(95)00254-5 PG 13 WC Chemistry, Multidisciplinary; Physics, Condensed Matter SC Chemistry; Physics GA UD531 UT WOS:A1996UD53100012 ER PT J AU OConnor, RP Mackert, JR Myers, ML Parry, EE AF OConnor, RP Mackert, JR Myers, ML Parry, EE TI Castability, opaque masking, and porcelain bonding of 17 porcelain-fused-to-metal alloys SO JOURNAL OF PROSTHETIC DENTISTRY LA English DT Article ID PALLADIUM ALLOYS; COLOR; RESTORATIONS; CERAMOMETALS; THICKNESS; ACCURACY; STRENGTH AB Seventeen porcelain-fused-to-metal alloys, which represented a cross section of the various alloy types available, were evaluated for castability, opaque masking, and porcelain bond strength, The base metal alloys generally cast more completely than the noble alloys, with the presence of beryllium as an important factor for greater castability among the base metal alloys. Statistically significant differences were observed in the ability of an opaque porcelain to mask the different alloy substrates but no systematic effect of alloy type was observed. Porcelain bond testing revealed that nickel-chromium-beryllium alloys produced significantly better porcelain-metal bonds than nickel-chromium alloys without beryllium. In addition, it was found that palladium-copper alloys produced significantly better bonds with porcelain than palladium-cobalt alloys. C1 MED COLL GEORGIA,SCH DENT,DEPT ORAL REHABIL,DENT MAT LAB,AUGUSTA,GA 30912. MED COLL GEORGIA,SCH DENT,DEPT ORAL REHABIL,DIV DENT MAT,AUGUSTA,GA 30912. NIST,PAFFENBARGER RES CTR,ADA HLTH FDN,GAITHERSBURG,MD 20899. FU NIDCR NIH HHS [DE 06374] NR 30 TC 26 Z9 32 U1 0 U2 0 PU MOSBY-YEAR BOOK INC PI ST LOUIS PA 11830 WESTLINE INDUSTRIAL DR, ST LOUIS, MO 63146-3318 SN 0022-3913 J9 J PROSTHET DENT JI J. Prosthet. Dent. PD APR PY 1996 VL 75 IS 4 BP 367 EP 374 DI 10.1016/S0022-3913(96)90027-X PG 8 WC Dentistry, Oral Surgery & Medicine SC Dentistry, Oral Surgery & Medicine GA UD918 UT WOS:A1996UD91800005 PM 8642521 ER PT J AU Klose, JZ Fuhr, JR Wiese, WL AF Klose, JZ Fuhr, JR Wiese, WL TI Atomic branching ratio data for nitrogen-like species SO JOURNAL OF QUANTITATIVE SPECTROSCOPY & RADIATIVE TRANSFER LA English DT Article ID OSCILLATOR STRENGTH MEASUREMENTS; SELECTIVE ELECTRON-CAPTURE; NEUTRAL NITROGEN; SLOW COLLISIONS; OPACITY CALCULATIONS; VACUUM-ULTRAVIOLET; STATE; LINES; SPECTROSCOPY; PLASMA AB The branching ratio technique for radiometric calibrations in the vacuum ultraviolet spectral region is briefly reviewed. Lists of transitions suitable for use with the technique are given for nitrogen-like species (N I, O II, and Ne IV) along with pertinent data for their application. RP Klose, JZ (reprint author), NATL INST STAND & TECHNOL,GAITHERSBURG,MD 20899, USA. NR 30 TC 1 Z9 1 U1 0 U2 0 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD, ENGLAND OX5 1GB SN 0022-4073 J9 J QUANT SPECTROSC RA JI J. Quant. Spectrosc. Radiat. Transf. PD APR PY 1996 VL 55 IS 4 BP 413 EP 430 DI 10.1016/0022-4073(95)00177-8 PG 18 WC Optics; Spectroscopy SC Optics; Spectroscopy GA UG482 UT WOS:A1996UG48200001 ER PT J AU Palmer, DR AF Palmer, DR TI Rayleigh scattering from nonspherical particles SO JOURNAL OF THE ACOUSTICAL SOCIETY OF AMERICA LA English DT Article ID HYDROTHERMAL PLUMES AB A comprehensive framework is developed for calculating the intensity received by a monostatic sonar system due to backscattering from a cloud of nonspherical particles suspended in the ocean. The cloud can consist of different types of particles having arbitrary shapes, volume distributions, and orientations, as well as an overall mass density that varies spatially within the cloud. In the Rayleigh region it is possible to average over particle orientation exactly. The averaged backscattered intensity depends on particle shape through the eigenvalues of a tensor that can, in principle, be determined by solving a boundary value problem for a harmonic function. Since the solution to this boundary value problem is out of reach practically, bounds are obtained on the eigenvalues using the theory of isoperimetric inequalities. Bounds can thereby be obtained on the backscattered intensity that are independent of particle shape. These bounds form the basis for obtaining estimates of the error that is made by assuming the particles in the cloud scatter sound as if they were spherical. A number of examples and applications are considered, the most important of which is the feasibility of a sonar to image black smoker hydrothermal plumes. The reassuring result that the spherical particle assumption is likely to lead to feasibility criteria that underestimate the performance of a sonar is obtained. The isoperimetric bounds are combined with the principle of maximum entropy, applied to the distribution of particle shapes, to obtain a new expression for the square of the amplitude for backscattering at wave number k(0) from a particle of volume V, specific bulk modulus e and specific density h: Phi(2)=(k(0)(2)V/4 pi)(2)[(e-1)/e+(h(2)-1)/2h](2). This amplitude is obtained by averaging over particle orientation and particle shape and is to be compared to the corresponding quantity for a sphere Phi(sp)(2)=(k(0)(2)V/4 pi)(2)[(e-1)/e +(3(h-1))/(2h+1)](2). The use of the new expression is preferred in situations where it is known the particle shapes are quite variable and irregular and where 1.0 less than or equal to h less than or equal to 2.5. In all the examples considered it is found the error that results from assuming the particles scatter sound as if they were spherical is small. This is comforting and consistent with one's intuition that in the Rayleigh region the scattered sound should be somewhat insensitive to the shape of the scatterer. RP Palmer, DR (reprint author), NOAA,ATLANTIC OCEANOG & METEOROL LAB,4301 RICKENBACKER CAUSEWAY,MIAMI,FL 33149, USA. NR 28 TC 11 Z9 11 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 APR PY 1996 VL 99 IS 4 BP 1901 EP 1912 DI 10.1121/1.415373 PN 1 PG 12 WC Acoustics; Audiology & Speech-Language Pathology SC Acoustics; Audiology & Speech-Language Pathology GA UF398 UT WOS:A1996UF39800012 ER PT J AU Dutton, RE Pagano, NJ Kim, RY AF Dutton, RE Pagano, NJ Kim, RY TI Crack initiation in borosilicate glass-SiC fiber composites SO JOURNAL OF THE AMERICAN CERAMIC SOCIETY LA English DT Article ID BRITTLE-MATRIX COMPOSITES AB The initiation of matrix microcracking was investigated in unidirectional glass matrix composites having controlled fiber spacing. Observations were taken from composites consisting of regular arrays of TiB2-coated SIGMA 1240 and carbon-coated SCS-6 monofilament SiC fibers in a series of borosilicate glasses, The thermal expansion mismatch between the fibers and glass matrix was varied such that the resulting radial stresses after processing ranged from tensile to compressive, The glass strongly bonds to the TiB2-coated SIGMA 1240 fiber but weakly bonds to the carbon coating of the SCS-6 fiber, allowing the investigation of the effects of bonding at the fiber/matrix interface. The observed crack initiation stresses of the various composites are compared to predictions based on a previously developed semiempirical model and used to study the influence of the volume fraction of fibers, residual stress state and interface strength. C1 UNIV DAYTON,RES INST,DAYTON,OH 45469. RP Dutton, RE (reprint author), NIST,MAT DIRECTORATE,WRIGHT LAB,WRIGHT PATTERSON AFB,OH 45433, USA. NR 19 TC 14 Z9 14 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 APR PY 1996 VL 79 IS 4 BP 865 EP 872 DI 10.1111/j.1151-2916.1996.tb08518.x PG 8 WC Materials Science, Ceramics SC Materials Science GA UG959 UT WOS:A1996UG95900008 ER PT J AU Fields, BA Wiederhorn, SM AF Fields, BA Wiederhorn, SM TI Creep cavitation in a siliconized silicon carbide tested in tension and flexure SO JOURNAL OF THE AMERICAN CERAMIC SOCIETY LA English DT Article ID HIGH-TEMPERATURE CREEP; DAMAGE-ENHANCED CREEP; ACCUMULATION; MECHANISMS; CERAMICS; NITRIDE; GROWTH AB Cavity formation was quantified in a grade of siliconized silicon carbide containing 33 vol% silicon, The type, size, and density of cavities were determined for smooth-bar specimens tested in both tension and bending, and for indented specimens tested in tension, In both tension and bending, the volume fraction of cavities was found to be proportional to the tensile creep strain, Cavities nucleated at random locations throughout the test specimen, eventually coalescing into cracks that were the source of failure at high temperatures, In tension, the strain to failure was about 1%, In flexure, stress relaxation at the tensile surface of test specimens helped stabilize cracks that formed during creep, As a consequence, strains to failure were about twice as large in bending as in tension, In tensile specimens containing large, >300 mu m, indentation cracks, cavitation was profuse near the crack tips, At a volume fraction of about 3%, cavities coalesced to form secondary cracks near the tip of the indentation crack, Cracks advanced by linkage of cavitation cracks with the indentation crack, Crack growth was intermittent, requiring the buildup of cavities in front of the crack tip before crack advance could occur, If the indentation crack length was less than about 200 mu m, cavity formation at the tip of the crack was not sufficient for crack advance, In such case, failure would have to occur by cavity coalescence and crack formation at some other location in the test specimen. RP Fields, BA (reprint author), NATL INST STAND & TECHNOL,MAT SCI & ENGN LAB,GAITHERSBURG,MD 20899, USA. NR 26 TC 18 Z9 18 U1 0 U2 4 PU AMER CERAMIC SOC PI WESTERVILLE PA 735 CERAMIC PLACE, PO BOX 6136, WESTERVILLE, OH 43081-6136 SN 0002-7820 J9 J AM CERAM SOC JI J. Am. Ceram. Soc. PD APR PY 1996 VL 79 IS 4 BP 977 EP 986 DI 10.1111/j.1151-2916.1996.tb08535.x PG 10 WC Materials Science, Ceramics SC Materials Science GA UG959 UT WOS:A1996UG95900025 ER PT J AU Liu, HY Lawn, BR Hsu, SM AF Liu, HY Lawn, BR Hsu, SM TI Hertzian contact response of tailored silicon nitride multilayers SO JOURNAL OF THE AMERICAN CERAMIC SOCIETY LA English DT Article ID FRACTURE-RESISTANCE MECHANISM; CERAMICS; TOUGHNESS; BEHAVIOR; STRENGTH; INDENTATION; ZIRCONIA; FAILURE; STRESS; SI3N4 AB The nature and degree of damage accumulation beneath Hertzian contacts in silicon nitride-based laminates are studied, Specimens with alternating homogeneous and heterogeneous layers are fabricated by a tape-casting route, with strong interlayer bonding, Homogeneous material consisting of relatively pure fine-grain silicon nitride is used as the overlayers, Heterogeneous material containing 10 to 30 wt% boron nitride platelets in a silicon nitride matrix, with weak platelet/matrix interphase boundaries, forms the underlayers, Contact tests with spherical indenters are used to monitor the stress-strain response of the laminates and to investigate the damage modes within the individual layers, The heterogeneous layer exhibits a distinctive ''softening'' in the stress-strain curve, indicating a quasi-plasticity in the silicon nitride associated with local microfailures at the platelet/matrix interfaces, In contrast to the well-defined cone cracks that develop within the tensile zone outside the contact area in bulk homogeneous silicon nitride, the damage in the laminates is widely distributed within the shear-compression zone below the contact, Fractures form incompletely in the homogeneous layers, as downward-propagating partial cone cracks and upward-propagating stable cracks, Comparatively extensive, diffuse microscopic damage occurs in the heterogeneous layers, culminating in a macroscopic failure that traverses these layers at higher loads, A strong synergism between the interlayer damage modes is apparent, Implications concerning the design of composite laminates for improved damage tolerance, with retention of strength and wear resistance, are considered. RP NATL INST STAND & TECHNOL, MAT SCI & ENGN LAB, GAITHERSBURG, MD 20899 USA. NR 48 TC 58 Z9 59 U1 0 U2 2 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 APR PY 1996 VL 79 IS 4 BP 1009 EP 1014 DI 10.1111/j.1151-2916.1996.tb08540.x PG 6 WC Materials Science, Ceramics SC Materials Science GA UG959 UT WOS:A1996UG95900030 ER PT J AU Held, IM Larichev, VD AF Held, IM Larichev, VD TI A scaling theory for horizontally homogeneous, baroclinically unstable flow on a beta plane SO JOURNAL OF THE ATMOSPHERIC SCIENCES LA English DT Article ID QUASI-GEOSTROPHIC TURBULENCE; MODEL AB The scaling argument developed by the authors in a previous work for eddy amplitudes and fluxes in a horizontally homogeneous, two-layer model on an f plane is extended to a beta plane. In terms of the nondimensional number xi = UI(beta lambda(2)), where lambda is the deformation radius and U is the mean thermal wind, the result for the rms eddy velocity V, the characteristic wavenumber of the energy-containing eddies and of the eddy-driven jets k(j), and the magnitude of the eddy diffusivity for potential vorticity D, in the limit xi >> 1, are as follows: V/U approximate to xi, k(j) lambda approximate to xi(-1), D/(U lambda) xi(2). Numerical simulations provide qualitative support for this scaling but suggest that it underestimates the sensitivity of these eddy statistics to the value of E. A generalization that is applicable to continuous stratification is suggested that leads to the estimates V approximate to (beta T-2)(-1), k(j) approximate to beta T, D approximate to (beta(2)T(3))(-1), where T is a timescale determined by the environment; in particular, it equals lambda U-1 in the two-layer model and N(f partial derivative(z)U)(-1) in a continuous flow with uniform shear and stratification. This same scaling has also been suggested as relevant to a continuously stratified fluid in the opposite limit, xi << 1. Therefore, the authors suggest that it may be of general relevance in planetary atmospheres and in the oceans. C1 PRINCETON UNIV,PROGRAM ATMOSPHER & OCEAN SCI,PRINCETON,NJ 08544. RP Held, IM (reprint author), PRINCETON UNIV,NOAA,GEOPHYS FLUID DYNAM LAB,POB 308,PRINCETON,NJ 08542, USA. NR 21 TC 147 Z9 148 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 APR 1 PY 1996 VL 53 IS 7 BP 946 EP 952 DI 10.1175/1520-0469(1996)053<0946:ASTFHH>2.0.CO;2 PG 7 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA UD085 UT WOS:A1996UD08500002 ER PT J AU Zhang, ZM Livigni, DJ Jones, RD Scott, TR AF Zhang, ZM Livigni, DJ Jones, RD Scott, TR TI Thermal modeling and analysis of laser calorimeters SO JOURNAL OF THERMOPHYSICS AND HEAT TRANSFER LA English DT Article AB We performed detailed thermal analysis and modeling of the C-series laser calorimeters at the National institute of Standards and Technology for calibrating laser power or energy meters, A finite element method was employed to simulate the space and time dependence of temperature at the calorimeter receiver. The inequivalence in the temperature response caused by different spatial distributions of tie heating power was determined, The inequivalence between electrical power applied to the front and rear portions of the receiver is approximate to 1.7%, and the inequivalence between the electrical and laser heating is estimated to be <0.05%. The computational results are in good agreement with experiments at the 1% level. The effects of the deposited energy, power duration, and relaxation time on the calibration factor and cooling constant were investigated. This article provides information for future design improvement on the laser calorimeters. C1 NATL INST STAND & TECHNOL,DIV OPTOELECTR,SOURCES & DETECTORS GRP,BOULDER,CO 80303. RP Zhang, ZM (reprint author), UNIV FLORIDA,DEPT MECH ENGN,GAINESVILLE,FL 32611, USA. NR 23 TC 5 Z9 6 U1 1 U2 2 PU AMER INST AERONAUT ASTRONAUT PI RESTON PA 1801 ALEXANDER BELL DRIVE, STE 500, RESTON, VA 22091 SN 0887-8722 J9 J THERMOPHYS HEAT TR JI J. Thermophys. Heat Transf. PD APR-JUN PY 1996 VL 10 IS 2 BP 350 EP 356 DI 10.2514/3.794 PG 7 WC Thermodynamics; Engineering, Mechanical SC Thermodynamics; Engineering GA UE790 UT WOS:A1996UE79000021 ER PT J AU Walker, WA AF Walker, WA TI Summer feeding habits of Dall's porpoise, Phocoenoides dalli, in the southern Sea of Okhotsk SO MARINE MAMMAL SCIENCE LA English DT Article DE Dall's porpoise; Phocoenoides dalli; food habits; Sea of Okhotsk; Japanese pilchard; Sardinops sagax melanostictus; Berryteuthis magister; walleye pollock; Theragra chalcogramma ID NORTHERN AB Stomach contents were analyzed from 85 Dall's porpoises, Phocoenoides dalli, taken in the southern Sea of Okhotsk during the summer of 1988. Thirteen species of fish and five species of cephalopods were identified. Fishes comprising 9 families were predominant and made up 79.9% of the total number of prey, with an overall occurrence in the stomachs of 100%. Three families of cephalopods made up 20.1% of the total number of prey ingested, with an overall occurrence of 74%. The Japanese pilchard, Sardinops sagax melanostictus, was the primary prey and represented 72.0% of the total prey in 97.3% of the stomachs examined. The gonatid squid, Berryteuthis magister, ranked second and made up 16.9% of the total prey in 61.6% of the stomachs. Walleye pollock, Theragra chalcogramma, was the third most abundant prey item consumed and represented 6.0% of the total, with an occurrence of 53.4%. Composition of the sample by the calculated total mass and caloric intake supports the numeric findings on the relative importance of the three major prey species to the Dall's porpoise diet. The Japanese pilchard was dearly dominant using these indices and constituted 65.4% of the total mass and 80.7% of the caloric intake. Berryteuthis magister made up 26.8% of the mass and 15.5% of the caloric intake. Walleye pollock contributed the least to the diet with 7.9% of the total mass and 3.8% of the caloric intake. Volumetric data indicate that porpoises are feeding heavily on Japanese pilchard throughout the daylight hours. Berryteuthis magister was probably fed upon in the late night or early morning hours. Occurrence of both Dall's porpoise and Japanese pilchard in the coastal waters of the southern Sea of Okhotsk is seasonal. The summer movements of Dall's porpoise into this region may be related to the seasonal migration and abundance of the Japanese pilchard. RP Walker, WA (reprint author), NOAA,NATL MARINE FISHERIES SERV,NATL MARINE MAMMAL LAB,ALASKA FISHERIES SCI CTR,SEATTLE,WA 98115, USA. NR 37 TC 18 Z9 18 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 APR PY 1996 VL 12 IS 2 BP 167 EP 181 DI 10.1111/j.1748-7692.1996.tb00569.x PG 15 WC Marine & Freshwater Biology; Zoology SC Marine & Freshwater Biology; Zoology GA UE447 UT WOS:A1996UE44700001 ER PT J AU Calambokidis, J Steiger, GH Evenson, JR Flynn, KR Balcomb, KC Claridge, DE Bloedel, P Straley, JM Baker, CS vonZiegesar, O Dahlheim, ME Waite, JM Darling, JD Ellis, G Green, GA AF Calambokidis, J Steiger, GH Evenson, JR Flynn, KR Balcomb, KC Claridge, DE Bloedel, P Straley, JM Baker, CS vonZiegesar, O Dahlheim, ME Waite, JM Darling, JD Ellis, G Green, GA TI Interchange and isolation of humpback whales off California and other North Pacific feeding grounds SO MARINE MAMMAL SCIENCE LA English DT Article DE humpback whale; Megaptera novaeangliae; photoidentification; interchange; feeding grounds; North Pacific ID MEGAPTERA-NOVAEANGLIAE; POPULATION CHARACTERISTICS AB Humpback whales feed in several high latitude areas of the North Pacific. We examined the interchange of humpback whales between one of these areas, off California, and those in other feeding grounds in the eastern North Pacific. Fluke photographs of 597 humpback whales identified off California between 1986 and 1992 were compared with those off Oregon and Washington (29); British Columbia (81); southeastern Alaska (343); Prince William Sound, Alaska (141); Kodiak Island, Alaska (104); Shumagin Islands, Alaska (22); and in the Bering Sea (7). A high degree of interchange, both inter- and intrayear, was found among humpback whales seen off California, Oregon, and Washington. A low rate of interchange was found between British Columbia and California: two whales seen near the British Columbia/Washington border were photographed off California in a different year. No interchange was found between California and the three feeding areas in Alaska. Humpback whales off California, Oregon, and Washington form a single intermixing feeding aggregation with only limited interchange with areas farther north. These findings are consistent with photographic identification studies in the North Atlantic and with genetic studies in both the North Atlantic and North Pacific. C1 CTR WHALE RES,FRIDAY HARBOR,WA 98250. UNIV AUCKLAND,SCH BIOL SCI,AUCKLAND,NEW ZEALAND. N GULF OCEAN SOC,HOMER,AK 99603. NOAA,NATL MARINE MAMMAL LAB,SEATTLE,WA 98115. W COAST WHALE RES FDN,VANCOUVER,BC V6C 3L2,CANADA. FISHERIES & OCEANS CANADA,PACIFIC BIOL STN,NANAIMO,BC V9R 5K6,CANADA. EBASCO ENVIRONM,BELLEVUE,WA 98004. RP Calambokidis, J (reprint author), CASCADIA RES,218 W 4TH AVE,OLYMPIA,WA 98501, USA. NR 41 TC 48 Z9 51 U1 1 U2 14 PU SOC MARINE MAMMALOGY PI LAWRENCE PA 1041 NEW HAMPSHIRE ST, LAWRENCE, KS 66044 SN 0824-0469 J9 MAR MAMMAL SCI JI Mar. Mamm. Sci. PD APR PY 1996 VL 12 IS 2 BP 215 EP 226 DI 10.1111/j.1748-7692.1996.tb00572.x PG 12 WC Marine & Freshwater Biology; Zoology SC Marine & Freshwater Biology; Zoology GA UE447 UT WOS:A1996UE44700004 ER PT J AU Choi, CS Sharpe, W Barker, J Fields, RJ AF Choi, CS Sharpe, W Barker, J Fields, RJ TI Neutron diffraction study of austempered ductile iron SO METALLURGICAL AND MATERIALS TRANSACTIONS A-PHYSICAL METALLURGY AND MATERIALS SCIENCE LA English DT Article AB Crystallographic properties of an austempered ductile iron (ADI) were studied by using neutron diffraction. A quantitative phase analysis based on Rietveld refinements revealed three component phases, alpha-Fe (ferrite), gamma-Fe (austenite), and graphite precipitate, with weight fractions of 66.0, 31.5, and 2.5 pct, respectively. The ferrite phases of the samples were found to be tetragonal, I4/mmm, with a c/a ratio of about 0.993, which is very close to the body-centered cubic (bcc) structure; The austenite phase had C atoms occupying the octahedral site of the face-centered cubic (fee) unit cell with about 8 pct occupancy ratio, A strong microstrain broadening was observed for the two Fe phases of the samples. The particle sizes of the acicular ferrite phase were studied by using small angle neutron scattering. The analysis suggested a mean rod diameter of 700 Angstrom. The scattering invariant predicts a ferrite volume fraction consistent with the powder diffraction analysis. A textbook case of nodular graphite segregation, with average diameters ranging from 10 to 20 mu m, was observed by optical micrography. C1 NATL INST STAND & TECHNOL,MAT SCI & ENGN LAB,GAITHERSBURG,MD 20899. RP Choi, CS (reprint author), USA,ARMAMENT RES DEV & ENGN CTR,PICATINNY ARSENAL,NJ 07806, USA. NR 14 TC 3 Z9 3 U1 0 U2 2 PU MINERALS METALS MATERIALS SOC PI WARRENDALE PA 420 COMMONWEALTH DR, WARRENDALE, PA 15086 SN 1073-5623 J9 METALL MATER TRANS A JI Metall. Mater. Trans. A-Phys. Metall. Mater. Sci. PD APR PY 1996 VL 27 IS 4 BP 923 EP 928 DI 10.1007/BF02649759 PG 6 WC Materials Science, Multidisciplinary; Metallurgy & Metallurgical Engineering SC Materials Science; Metallurgy & Metallurgical Engineering GA UG103 UT WOS:A1996UG10300011 ER PT J AU Hoss, M Jaruga, P Zastawny, TH Dizdaroglu, M Paabo, S AF Hoss, M Jaruga, P Zastawny, TH Dizdaroglu, M Paabo, S TI DNA damage and DNA sequence retrieval from ancient tissues SO NUCLEIC ACIDS RESEARCH LA English DT Article ID OXIDATIVE DAMAGE; EXTRACTION AB Gas chromatography/mass spectrometry (GC/MS) was used to determine the amounts of eight oxidative base modifications in DNA extracted from 11 specimens of bones and soft tissues, ranging in age from 40 to >50000 years. Among the compounds assayed hydantoin derivatives of pyrimidines were quantitatively dominant. From five of the specimens endogenous ancient DNA sequences could be amplified by PCR. The DNA from these specimens contained substantially lower amounts of hydantoins than the six specimens from which no DNA could be amplified. Other types of damage, e.g. oxidation products of purines, did not correlate with the inability to retrieve DNA sequences, Furthermore, all samples with low amounts of damage and from which DNA could be amplified stemmed from regions where low temperatures have prevailed throughout the burial period of the specimens. C1 UNIV MUNICH,INST ZOOL,D-80021 MUNICH,GERMANY. NATL INST STAND & TECHNOL,CHEM SCI & TECHNOL LAB,GAITHERSBURG,MD 20899. MED ACAD,DEPT CLIN BIOCHEM,PL-85094 BYDGOSZCZ,POLAND. RI Jaruga, Pawel/M-4378-2015 NR 16 TC 230 Z9 239 U1 1 U2 36 PU OXFORD UNIV PRESS UNITED KINGDOM PI OXFORD PA WALTON ST JOURNALS DEPT, OXFORD, ENGLAND OX2 6DP SN 0305-1048 J9 NUCLEIC ACIDS RES JI Nucleic Acids Res. PD APR 1 PY 1996 VL 24 IS 7 BP 1304 EP 1307 DI 10.1093/nar/24.7.1304 PG 4 WC Biochemistry & Molecular Biology SC Biochemistry & Molecular Biology GA UF157 UT WOS:A1996UF15700018 PM 8614634 ER PT J AU Gouesbet, G Letellier, C Grehan, G Hodges, JT AF Gouesbet, G Letellier, C Grehan, G Hodges, JT TI Generalized optical theorem for on-axis Gaussian beams SO OPTICS COMMUNICATIONS LA English DT Article ID LORENZ-MIE THEORY; SCATTERING; COEFFICIENTS AB The optical theorem for an incident plane wave interacting with a finite scatterer is generalized to the case of on-axis Gaussian beams, taken as examples of shaped beams. Our results are restricted in this paper to homogeneous spheres. The beams are defined by using (i) the standard description (ii) the localized approximation and (iii) the modified localized approximation. Rigorous expressions generalizing the classical plane wave case expression are given and numerically discussed. A recently proposed approximation is investigated in order to point out assumptions underlying its validity. C1 NIST,CHEM SCI & TECHNOL LAB,GAITHERSBURG,MD 20899. RP Gouesbet, G (reprint author), INSA,CORIA,LAB ENERGET SYST & PROCEDES,URA CNRS 230,BP 08,F-76130 MONT ST AIGNAN,FRANCE. RI Letellier, Christophe/E-2245-2012; Hodges, Joseph/B-4578-2009 OI Letellier, Christophe/0000-0003-3603-394X; NR 26 TC 19 Z9 19 U1 0 U2 5 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0030-4018 J9 OPT COMMUN JI Opt. Commun. PD APR 1 PY 1996 VL 125 IS 1-3 BP 137 EP 157 DI 10.1016/0030-4018(95)00732-6 PG 21 WC Optics SC Optics GA UG580 UT WOS:A1996UG58000022 ER PT J AU Sokol, GM VanMeurs, KP Thorn, WT Rivera, O Wright, LL Sams, RL AF Sokol, GM VanMeurs, KP Thorn, WT Rivera, O Wright, LL Sams, RL TI Nitrogen dioxide kinetics in a neonatal continuous flow ventilatory circuit. SO PEDIATRIC RESEARCH LA English DT Meeting Abstract C1 NATL INST STAND & TECHNOL,NICHD,NEONATAL RES NETWORK,WASHINGTON,DC. NR 0 TC 0 Z9 0 U1 0 U2 0 PU WILLIAMS & WILKINS PI BALTIMORE PA 351 WEST CAMDEN ST, BALTIMORE, MD 21201-2436 SN 0031-3998 J9 PEDIATR RES JI Pediatr. Res. PD APR PY 1996 VL 39 IS 4 BP 2084 EP 2084 PN 2 PG 1 WC Pediatrics SC Pediatrics GA UD238 UT WOS:A1996UD23802083 ER PT J AU VanMeurs, KP Sokol, GM Wright, LL Rivera, O Thom, WJ AF VanMeurs, KP Sokol, GM Wright, LL Rivera, O Thom, WJ TI Minimizing nitrogen dioxide exposure during inhaled nitric oxide therapy. SO PEDIATRIC RESEARCH LA English DT Meeting Abstract C1 NICHHD,NEONATAL RES NETWORK,BETHESDA,MD 20892. NATL INST STAND & TECHNOL,BOULDER,CO 80303. NR 0 TC 0 Z9 0 U1 0 U2 0 PU WILLIAMS & WILKINS PI BALTIMORE PA 351 WEST CAMDEN ST, BALTIMORE, MD 21201-2436 SN 0031-3998 J9 PEDIATR RES JI Pediatr. Res. PD APR PY 1996 VL 39 IS 4 BP 2105 EP 2105 PN 2 PG 1 WC Pediatrics SC Pediatrics GA UD238 UT WOS:A1996UD23802104 ER PT J AU Feigin, L Konovalov, O Wiesler, DG Majkrzak, CF Berzina, T Troitsky, V AF Feigin, L Konovalov, O Wiesler, DG Majkrzak, CF Berzina, T Troitsky, V TI Neutron reflectivity study of structural changes in barium stearate Langmuir-Blodgett films during annealing SO PHYSICA B LA English DT Article; Proceedings Paper CT 4th International Conference on Surface X-Ray and Neutron Scattering CY JUN, 1995 CL LAKE GENEVA, WI SP Argonne Natl Lab ID X-RAY-DIFFRACTION; MANGANESE STEARATE; SMALL NUMBERS; LAYERS AB Neutron and X-ray reflectivity measurements are used to characterize Langmuir-Blodgett films composed of 20 bilayers of barium stearate. To facilitate contrast for neutron measurements, molecules with deuterated aliphatic tails were used for the depostion of every odd-numbered bilayer. Model fitting of both data sets yields values of the following: the bilayer thickness, the area per molecule, the ratio of undissociated carboxylic acid groups to Ba salts, and the degree of mixing between neighboring bilayers (30%) ocurring on deposition. Structural changes of the film during temperature annealing at 66 degrees C were studied. Interlayer diffusion, evaporation of matter, and distortion were observed, Quantitative parameters of these processes were calculated using two complementary approaches - modeling and Bragg peak analysis based on general ideas about film structure. In particular, interdiffusion reduces the intensities of different Bragg peaks differently, depending on the operative mode of interdiffusion. After 90 min of annealing, complete mixing of deuterated and hydrogenated aliphatic chains was achieved. At that time, 35% of the film had evaporated. This amount is very close to the content of undissociated acid groups. C1 GEORGE WASHINGTON UNIV,DEPT PHYS,WASHINGTON,DC 20052. RUSSIAN ACAD SCI,INST CRYSTALLOG,MOSCOW,RUSSIA. NATL INST STAND & TECHNOL,GAITHERSBURG,MD 20899. ZELENOGRAD PHYS PROBLEMS INST,ZELENOGRAD,RUSSIA. NR 14 TC 12 Z9 13 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 APR PY 1996 VL 221 IS 1-4 BP 185 EP 191 DI 10.1016/0921-4526(95)00922-1 PG 7 WC Physics, Condensed Matter SC Physics GA UR277 UT WOS:A1996UR27700027 ER PT J AU Lee, DD McClain, BR Carvalho, BL Mochrie, SGJ Litster, JD Chen, SH Majkrzak, CF Satija, SK AF Lee, DD McClain, BR Carvalho, BL Mochrie, SGJ Litster, JD Chen, SH Majkrzak, CF Satija, SK TI Interfacial scattering from surfactant monolayers in microemulsions SO PHYSICA B LA English DT Article; Proceedings Paper CT 4th International Conference on Surface X-Ray and Neutron Scattering CY JUN, 1995 CL LAKE GENEVA, WI SP Argonne Natl Lab ID X-RAY; MICRO-EMULSIONS AB Although conceptually very simple, the statistical mechanics of surfactant monolayers in solution give rise to the rich phase behavior and novel physical properties of these systems. The fluctuations due to capillary waves of a single saturated monolayer are studied using X-ray reflectivity. The interfacial tension and bending rigidity are found to be very small and account for the disordered structure of bicontinuous microemulsions. Neutron scattering techniques are also used to measure the decay of structural correlations among the surfactant monolayers within a microemulsion phase, and these results are explained using a Ginzburg-Landau theory. C1 NATL INST STAND & TECHNOL,DIV REACTOR RADIAT,GAITHERSBURG,MD 20899. RP Lee, DD (reprint author), MIT,CTR MAT SCI & ENGN,CAMBRIDGE,MA 02139, USA. RI Lee, Daniel/B-5753-2013 NR 18 TC 6 Z9 6 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 APR PY 1996 VL 221 IS 1-4 BP 296 EP 300 DI 10.1016/0921-4526(95)00940-X PG 5 WC Physics, Condensed Matter SC Physics GA UR277 UT WOS:A1996UR27700045 ER PT J AU Wong, APY Karim, A Han, CC AF Wong, APY Karim, A Han, CC TI Neutron reflection studies of phase separation and transesterification in thin film polymer blends SO PHYSICA B LA English DT Article; Proceedings Paper CT 4th International Conference on Surface X-Ray and Neutron Scattering CY JUN, 1995 CL LAKE GENEVA, WI SP Argonne Natl Lab ID SPINODAL DECOMPOSITION; IMMISCIBILITY LOOP; POLYCARBONATE; TIME AB Neutron reflection is used to investigate the evolution of structure and surface segregation in thin films of a binary polymer blend, deuterated polymethamethacrylate (dPMMA) and polycarbonate (PC), This blend film simultaneously undergoes phase separation and reaction by trans-esterification. A large increase of the critical scattering length density in the first few minutes of annealing at 200 degrees C reflected the rapid layering of the dPMMA at the silicon surface. Further annealing progressively smeared out the specular peak in favor of the off-specular signal in the form of a butterfly pattern reflecting the in-plane anisotropy of the thin film phase separation. C1 NATL INST STAND & TECHNOL,DIV POLYMERS,GAITHERSBURG,MD 20814. RP Wong, APY (reprint author), ARGONNE NATL LAB,INTENSE PULSE NEUTRON SOURCE,9700 S CASS AVE,ARGONNE,IL 60439, USA. NR 26 TC 5 Z9 5 U1 1 U2 4 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0921-4526 J9 PHYSICA B JI Physica B PD APR PY 1996 VL 221 IS 1-4 BP 301 EP 305 DI 10.1016/0921-4526(95)00941-8 PG 5 WC Physics, Condensed Matter SC Physics GA UR277 UT WOS:A1996UR27700046 ER PT J AU Lee, LT Factor, BJ Kent, MS Rondelez, F AF Lee, LT Factor, BJ Kent, MS Rondelez, F TI Effects of mobile polymer concentration and chain length on the structure of tethered chains SO PHYSICA B LA English DT Article; Proceedings Paper CT 4th International Conference on Surface X-Ray and Neutron Scattering CY JUN, 1995 CL LAKE GENEVA, WI SP Argonne Natl Lab ID DIBLOCK COPOLYMER MONOLAYERS; NEUTRON REFLECTIVITY; BLOCK COPOLYMERS; GRAFTED POLYMERS; INTERFACE; POLYSTYRENE; SCATTERING; SURFACES; SOLVENT; BRUSHES AB Using specular neutron reflectivity, we have measured the structure of tethered polymer layers immersed in a solution of mobile chains of the same chemical composition. The tethered polymer layer is a stable Langmuir film of a diblock copolymer spread on the air-liquid interface of a selective solvent. Due to the restricted conformational freedom of the grafted chain, a depletion layer at the grafting surface is expected. In our system, this depletion tow is enhanced and thus observable experimentally due to a repulsion between the polymer and the surface. The structure of the tethered layer is adequately described by a parabolic profile followed by an exponential tail, with a depletion layer at the surface. In the presence of mobile chains in solution, the grafted polymer layer is compressed: the thickness decreases and the monomer volume fraction increases. This compression may result from a re-equilibration of the osmotic pressure of the polymer layer, or from a screening of the monomer excluded volume interaction due to penetration of the mobile chains into the grafted layer. In this paper, we present our experimental data on the effects of mobile polymer concentration and chain length on the structure of the tethered chain. From these data, we construct a phase diagram to identify the regions of interpenetration of the mobile chains into the grafted layer. C1 NIST,GAITHERSBURG,MD 20899. INST CURIE,F-75231 PARIS,FRANCE. RP Lee, LT (reprint author), CTR ETUD SACLAY,LAB LEON BRILLOUIN,F-91191 GIF SUR YVETTE,FRANCE. NR 32 TC 5 Z9 5 U1 0 U2 1 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0921-4526 J9 PHYSICA B JI Physica B PD APR PY 1996 VL 221 IS 1-4 BP 320 EP 324 DI 10.1016/0921-4526(95)00944-2 PG 5 WC Physics, Condensed Matter SC Physics GA UR277 UT WOS:A1996UR27700049 ER PT J AU Karim, A Douglas, JF Horkay, F Fetters, LJ Satija, SK AF Karim, A Douglas, JF Horkay, F Fetters, LJ Satija, SK TI Comparative swelling of gels and polymer brush layers SO PHYSICA B LA English DT Article; Proceedings Paper CT 4th International Conference on Surface X-Ray and Neutron Scattering CY JUN, 1995 CL LAKE GENEVA, WI SP Argonne Natl Lab ID DEPENDENCE; SYSTEMS; CHAINS AB The swelling of chemically end-grafted polystyrene brushes in a marginal solvent is investigated as a function of molecular weight M(W), grafting density sigma, and solvent quality tau = (T - theta)/T by specular neutron reflection and these swelling results are compared to previous measurements on swollen polymer networks. This comparison is motivated by the view of a polymer brush as a variety of ''gel'' where the crosslinks (grafting points) are constrained to lie on a surface. In accordance with this analogy, the temperature dependence of the brush and the network swelling is found to be qualitatively similar and the relative degree of brush and network swelling is found to diminish with an increase of sigma and the cross-link density nu, respectively. The network swelling data are taken from a previous study by Zrinyi and Horkay [1] who found an apparent universal master curve describing the swelling of uncharged gels with temperature. An attempt to describe the swelling of polymer brushes having a range of molecular weights by similar reduced variables led to a fairly good description of the brush swelling data, but the scaling curves for the gels and the brushes do not exactly coincide. C1 EXXON RES & ENGN CO,ANNANDALE,NJ 08801. RP Karim, A (reprint author), NATL INST STAND & TECHNOL,GAITHERSBURG,MD 20899, USA. NR 22 TC 17 Z9 17 U1 0 U2 3 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0921-4526 J9 PHYSICA B JI Physica B PD APR PY 1996 VL 221 IS 1-4 BP 331 EP 336 DI 10.1016/0921-4526(95)00946-9 PG 6 WC Physics, Condensed Matter SC Physics GA UR277 UT WOS:A1996UR27700051 ER PT J AU Perahia, D Wiesler, DG Satija, SK Fetters, LJ Sinha, SK Grest, GS AF Perahia, D Wiesler, DG Satija, SK Fetters, LJ Sinha, SK Grest, GS TI Neutron reflectivity of end grafted polymers in poor solvent: Kinetic effects SO PHYSICA B LA English DT Article; Proceedings Paper CT 4th International Conference on Surface X-Ray and Neutron Scattering CY JUN, 1995 CL LAKE GENEVA, WI SP Argonne Natl Lab ID DIBLOCK COPOLYMER MONOLAYERS; MONTE-CARLO SIMULATION; DENSITY PROFILE; BRUSHES; DYNAMICS; CHAINS; INTERFACE; SURFACES; LAYERS; FORCES AB Kinetics of adsorption of polymers on a solid surface in poor solvent and the competition between long and short chains were studied using neutron reflectivity. A brush which consists of a 375 K deuterated polystyrene terminated by a zwitterionic end group was grafted on a single crystal silicon wafer from a protonated cyclohexane solution. We found that the long deuterated polymer forms a density profile qualitatively similar to a 50 K protonated polymer studied previously. As for the low molecular weight polymer, the profile consists of a denser layer at the solid surface, a step-like profile convoluted with a Gaussian roughness and an exponential tail which stretches out almost to the length of the same molecular weight in good solvent. Our results also suggest that the brush, formed in poor solvent, grows in islands and eventually covers the entire surface. After equilibrium was reached, the brush formed by the 375 K polymer, was exposed to a low molecular weight, 26 K protonated polymer. The profile of the long deuterated layer was studied as a function of time. In poor solvent, a new equilibrium is formed between the long and the short polymers where the exact composition of the long and short chains depends on the temperature and the ratio of the molecular weights. C1 EXXON RES & ENGN CO,ANNANDALE,NJ 08801. NIST,GAITHERSBURG,MD 20899. NR 37 TC 6 Z9 6 U1 1 U2 3 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0921-4526 J9 PHYSICA B JI Physica B PD APR PY 1996 VL 221 IS 1-4 BP 337 EP 341 DI 10.1016/0921-4526(95)00947-7 PG 5 WC Physics, Condensed Matter SC Physics GA UR277 UT WOS:A1996UR27700052 ER PT J AU Gehring, PM Vigliante, A McMorrow, DF Gibbs, D Majkrzak, CF Helgesen, G Cowley, RA Ward, RCC Wells, MR AF Gehring, PM Vigliante, A McMorrow, DF Gibbs, D Majkrzak, CF Helgesen, G Cowley, RA Ward, RCC Wells, MR TI Observation of two length scales above T-N in a holmium thin film SO PHYSICA B LA English DT Article; Proceedings Paper CT 4th International Conference on Surface X-Ray and Neutron Scattering CY JUN, 1995 CL LAKE GENEVA, WI SP Argonne Natl Lab ID X-RAY-SCATTERING; CRITICAL FLUCTUATIONS AB Two-axis neutron-scattering measurements on a 1 mu m thick holmium film reveal the presence of two magnetic correlation lengths above TN that are qualitatively similar to those recently observed in X-ray and neutron scattering studies of bulk holmium and terbium. The scattering profile is well described by a broad Lorentzian plus a narrow Lorentzian-squared lineshape with widths that, for temperatures sufficiently close to T-N, differ by a factor of ten or more. C1 BROOKHAVEN NATL LAB,UPTON,NY 11973. RISO NATL LAB,DK-4000 ROSKILDE,DENMARK. UNIV OXFORD,OXFORD OX1 3PU,ENGLAND. INST ENERGITEKNIKK,N-2007 KJELLER,NORWAY. RP Gehring, PM (reprint author), NIST,GAITHERSBURG,MD 20899, USA. RI McMorrow, Desmond/C-2655-2008; OI McMorrow, Desmond/0000-0002-4947-7788; Gehring, Peter/0000-0002-9236-2046 NR 23 TC 8 Z9 8 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 APR PY 1996 VL 221 IS 1-4 BP 398 EP 404 DI 10.1016/0921-4526(95)00956-6 PG 7 WC Physics, Condensed Matter SC Physics GA UR277 UT WOS:A1996UR27700061 ER PT J AU Lee, TL Qian, Y Lyman, PF Woicik, JC Pellegrino, JG Bedzyk, MJ AF Lee, TL Qian, Y Lyman, PF Woicik, JC Pellegrino, JG Bedzyk, MJ TI The use of X-ray standing waves and evanescent-wave emission to study buried strained-layer heterostructures SO PHYSICA B LA English DT Article; Proceedings Paper CT 4th International Conference on Surface X-Ray and Neutron Scattering CY JUN, 1995 CL LAKE GENEVA, WI SP Argonne Natl Lab ID DIFFRACTION AB A heteroepitaxial structure consisting of I ML InAs grown on GaAs(001) and then capped with 25 Angstrom GaAs was examined by the X-ray standing wave (XSW) method. By monitoring the In L fluorescence while scanning through the GaAs(004) Bragg reflection, the perpendicular strain within the InAs layer was directly measured to be 7.7%, which is in good agreement with macroscopic elasticity theory (7.3%). We also demonstrate that, combined with the evanescent-wave-emission effect, the XSW method can be used to measure the strain-induced displacement of the cap layer in the growth direction. C1 NORTHWESTERN UNIV,MAT RES CTR,EVANSTON,IL 60208. ARGONNE NATL LAB,DIV SCI MAT,ARGONNE,IL 60439. NIST,GAITHERSBURG,MD 20899. RP Lee, TL (reprint author), NORTHWESTERN UNIV,DEPT MAT SCI & ENGN,EVANSTON,IL 60208, USA. RI Bedzyk, Michael/B-7503-2009; Bedzyk, Michael/K-6903-2013 NR 14 TC 12 Z9 12 U1 1 U2 1 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0921-4526 J9 PHYSICA B JI Physica B PD APR PY 1996 VL 221 IS 1-4 BP 437 EP 444 DI 10.1016/0921-4526(95)00964-7 PG 8 WC Physics, Condensed Matter SC Physics GA UR277 UT WOS:A1996UR27700069 ER PT J AU Majkrzak, CF Berk, NF AF Majkrzak, CF Berk, NF TI Exact determination of the neutron reflection amplitude or phase SO PHYSICA B LA English DT Article; Proceedings Paper CT 4th International Conference on Surface X-Ray and Neutron Scattering CY JUN, 1995 CL LAKE GENEVA, WI SP Argonne Natl Lab AB We show that by using a known reference layer having three tunable values of scattering length density, an exact determination of the complex neutron specular reflection amplitude can be made for any unknown real potential (i.e., in the case where there is no effective absorption). Furthermore, with two such reference layers, one preceeding and the other following the unknown potential of interest, the individual elements of the transfer matrix can be obtained to within a single algebraic sign. These straightforward yet remarkable general results are valid even in the dynamical regime where the conventional Born approximation fails. Thus, it becomes feasible to consider direct solutions of the inverse scattering problem which yield the unknown scattering length density profile normal to the reflecting surface directly and unambiguously from the reflection amplitude. RP Majkrzak, CF (reprint author), NIST,MAT SCI & ENGN LAB,BLDG 235,GAITHERSBURG,MD 20899, USA. NR 15 TC 40 Z9 40 U1 0 U2 1 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0921-4526 J9 PHYSICA B JI Physica B PD APR PY 1996 VL 221 IS 1-4 BP 520 EP 523 DI 10.1016/0921-4526(95)00974-4 PG 4 WC Physics, Condensed Matter SC Physics GA UR277 UT WOS:A1996UR27700079 ER PT J AU Majkrzak, CF AF Majkrzak, CF TI Neutron scattering studies of magnetic thin films and multilayers SO PHYSICA B-CONDENSED MATTER LA English DT Article; Proceedings Paper CT 4th International Conference on Surface X-Ray and Neutron Scattering CY JUN, 1995 CL LAKE GENEVA, WI SP Argonne Natl Lab ID HOLMIUM-YTTRIUM SUPERLATTICES; DY-Y SUPERLATTICES; X-RAY SCATTERING; FERROMAGNETIC MOMENTS; INTERLAYER EXCHANGE; LARMOR PRECESSION; DEPTH PROFILES; SPIN SLIPS; FE LAYERS; DIFFRACTION AB The basic principles of the elastic scattering of polarized neutrons from magnetic films and thin film superlattices, both kinematically as well as dynamically in the continuum limit, are summarized first. The quantitative accuracy presently attainable in practice is discussed along with other relevant issues regarding experimental technique and data analysis. Investigations of interlayer coupling and the effects of strain and finite thickness in single crystalline, epitaxially grown superlattices are reviewed, focussing on specular neutron diffraction and reflectivity measurements. These superlattices include rare earth and semiconductor systems in addition to those that exhibit ''giant'' magnetoresistive effects and which are of particular current technological interest. A survey of some of the more recent studies of the enhancement/reduction of ferromagnetic moments at an interface with a nonmagnetic material is then presented. Finally, several future research directions, for example, magnetic nonspecular scattering and studies of the magnetic state of the materials which form the intervening layers between coherently coupled ferromagnetic layers in superlattices, are discussed. RP NIST, DIV REACTOR RADIAT, MAT SCI & ENGN LAB, GAITHERSBURG, MD 20899 USA. NR 91 TC 105 Z9 107 U1 1 U2 8 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0921-4526 EI 1873-2135 J9 PHYSICA B JI Physica B PD APR PY 1996 VL 221 IS 1-4 BP 342 EP 356 DI 10.1016/0921-4526(95)00948-5 PG 15 WC Physics, Condensed Matter SC Physics GA UR277 UT WOS:A1996UR27700053 ER PT J AU Schreyer, A Ankner, JF Schafer, M Zabel, H Majkrzak, CF Grunberg, P AF Schreyer, A Ankner, JF Schafer, M Zabel, H Majkrzak, CF Grunberg, P TI Correlation between non-collinear exchange coupling and interface structure in Fe/Cr(001) superlattices SO PHYSICA B-CONDENSED MATTER LA English DT Article; Proceedings Paper CT 4th International Conference on Surface X-Ray and Neutron Scattering CY JUN, 1995 CL LAKE GENEVA, WI SP Argonne Natl Lab ID BIQUADRATIC EXCHANGE; MAGNETIC MULTILAYERS; MECHANISM AB Using polarized neutron reflectometry with polarization analysis we have studied the non-collinear interlayer exchange coupling in Fe/Cr(001) superlattices as a function of growth temperature. From diffuse X-ray spectra we find that the occurence of non-collinear spin structures is correlated with long range lateral Cr-thickness fluctuations which, in turn, depend on the growth temperature. This finding leads the way to a better understanding of the origin of non-collinear coupling in Fe/Cr(001). C1 UNIV MISSOURI, RES REACTOR, COLUMBIA, MO 65211 USA. FORSCHUNGSZENTRUM JULICH, FORSCHUNGSZENTRUM, D-52425 JULICH, GERMANY. NIST, GAITHERSBURG, MD 20899 USA. RP RUHR UNIV BOCHUM, D-44780 BOCHUM, GERMANY. RI Zabel, Hartmut/C-1994-2009; OI Ankner, John/0000-0002-6737-5718 NR 19 TC 9 Z9 9 U1 1 U2 2 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0921-4526 EI 1873-2135 J9 PHYSICA B JI Physica B PD APR PY 1996 VL 221 IS 1-4 BP 366 EP 369 DI 10.1016/0921-4526(95)00950-7 PG 4 WC Physics, Condensed Matter SC Physics GA UR277 UT WOS:A1996UR27700055 ER PT J AU Zhang, H Satija, SK Gallagher, PD Dura, JA Ritley, K Flynn, CP Ankner, JF AF Zhang, H Satija, SK Gallagher, PD Dura, JA Ritley, K Flynn, CP Ankner, JF TI Diffraction of neutron standing waves in thin films with resonance enhancement SO PHYSICA B-CONDENSED MATTER LA English DT Article; Proceedings Paper CT 4th International Conference on Surface X-Ray and Neutron Scattering CY JUN, 1995 CL LAKE GENEVA, WI SP Argonne Natl Lab ID GRAZING-INCIDENCE DIFFRACTION; CRITICAL SURFACE SCATTERING; X-RAY-DIFFRACTION; BRAGG-DIFFRACTION; ANGLES; REFLECTION AB Diffraction of neutron standing waves in thin films has been demonstrated for the first time with experiments on an epitaxial Y/Gd/Y/Nb/Al2O3 sample. Resonance enhancement in the diffraction intensity has been observed. The new diffraction scheme for neutrons and X-rays provides an oscillatory spatial concentration in thin films, in contrast to the evanescent diffraction which provides an exponential concentration. It also discriminates against diffraction background from substrate, and may be especially useful when diffraction in transmission geometry is not available due to high absorption of substrate. C1 UNIV MARYLAND, DEPT MAT & NUCL ENGN, COLLEGE PK, MD 20742 USA. UNIV ILLINOIS, DEPT PHYS, URBANA, IL 61801 USA. UNIV ILLINOIS, MAT RES LAB, URBANA, IL 61801 USA. UNIV MISSOURI, RES REACTOR, COLUMBIA, MO 65211 USA. RP NIST, DIV REACTOR RADIAT, GAITHERSBURG, MD 20899 USA. RI Dura, Joseph/B-8452-2008; OI Dura, Joseph/0000-0001-6877-959X; Ankner, John/0000-0002-6737-5718 NR 34 TC 0 Z9 0 U1 0 U2 2 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0921-4526 EI 1873-2135 J9 PHYSICA B JI Physica B PD APR PY 1996 VL 221 IS 1-4 BP 450 EP 454 DI 10.1016/0921-4526(95)00966-3 PG 5 WC Physics, Condensed Matter SC Physics GA UR277 UT WOS:A1996UR27700071 ER PT J AU Zhang, H AF Zhang, H TI Diffraction of neutron standing waves in thin films SO PHYSICA B-CONDENSED MATTER LA English DT Article; Proceedings Paper CT 4th International Conference on Surface X-Ray and Neutron Scattering CY JUN, 1995 CL LAKE GENEVA, WI SP Argonne Natl Lab ID X-RAY-DIFFRACTION; GRAZING-INCIDENCE DIFFRACTION; CRITICAL SURFACE SCATTERING; TOTAL-EXTERNAL-REFLECTION; BRAGG-DIFFRACTION; PERFECT CRYSTALS; ANGLES AB Diffraction of neutron standing waves in thin films is proposed in this paper and the diffraction intensity is calculated using the distorted-wave Born approximation (DWBA). Resonance enhancement in diffraction intensity is predicted. The intensity distributions of both the reflected diffracted beam and transmitted diffracted beam can now be calculated. The effect of the surface miscut is also included in the quantitative calculation. Tn general, the proposed new diffraction geometry can discriminate against substrate diffraction background, provide variable spatial concentration within the film sample, and be equally applied for X-rays as for neutrons. C1 UNIV MARYLAND, DEPT MAT & NUCL ENGN, COLLEGE PK, MD 20742 USA. RP NIST, DIV REACTOR RADIAT, GAITHERSBURG, MD 20899 USA. NR 39 TC 0 Z9 0 U1 0 U2 1 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0921-4526 EI 1873-2135 J9 PHYSICA B JI Physica B PD APR PY 1996 VL 221 IS 1-4 BP 455 EP 468 DI 10.1016/0921-4526(95)00967-1 PG 14 WC Physics, Condensed Matter SC Physics GA UR277 UT WOS:A1996UR27700072 ER PT J AU Serpa, FG Meyer, ES Morgan, CA Gillaspy, JD Sugar, J Roberts, JR Brown, CM Feldman, U AF Serpa, FG Meyer, ES Morgan, CA Gillaspy, JD Sugar, J Roberts, JR Brown, CM Feldman, U TI Anomalous Z dependence of a magnetic dipole transition in the Ti I isoelectronic sequence SO PHYSICAL REVIEW A LA English DT Article ID DIRAC-FOCK; 2-ELECTRON IONS AB In isoelectronic sequences, transition wavelengths ordinarily move rapidly to shorter wavelengths as Z increases. However, it has been predicted that a particular sequence of magnetic dipole (M1) transition wavelengths for the Ti-like ions, Xe+32 through U+70, remain relatively constant in the 320-400-nm range. In the present paper we extend the experimental identifications of the Ti-like M1 transitions from Ba and Xe to Nd (Nd+38) and Gd (Gd+42) to verify this behavior. Using the newly acquired wavelengths to adjust atomic parameters, we have also calculated improved wavelengths for all such M1 transitions between Xe (Z=54) and Os (Z=76). C1 USN,RES LAB,EO HULBURT CTR SPACE RES,WASHINGTON,DC 20375. UNIV NOTRE DAME,NOTRE DAME,IN 46556. TEXAS A&M UNIV,COLLEGE STN,TX 77843. RP Serpa, FG (reprint author), NIST,DIV ATOM PHYS,GAITHERSBURG,MD 20899, USA. NR 17 TC 35 Z9 35 U1 0 U2 0 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 1050-2947 J9 PHYS REV A JI Phys. Rev. A PD APR PY 1996 VL 53 IS 4 BP 2220 EP 2224 DI 10.1103/PhysRevA.53.2220 PG 5 WC Optics; Physics, Atomic, Molecular & Chemical SC Optics; Physics GA UE921 UT WOS:A1996UE92100046 ER PT J AU Kulander, KC Mies, FH Schafer, KJ AF Kulander, KC Mies, FH Schafer, KJ TI Model for studies of laser-induced nonlinear processes in molecules SO PHYSICAL REVIEW A LA English DT Article ID HARTREE-FOCK THEORY; MULTIPHOTON IONIZATION; FIELDS; DISSOCIATION; H-2+; PREDISSOCIATION; ATOMS AB The dynamics of strong-field (similar to 10(14) W/cm(2)) multiphoton processes in molecules can be investigated using a simple, collinear model for H-2(+). We discuss properties of this model and report preliminary calculations related to recent experimental results. We find that the excitation and ionization dynamics of the molecular ion depend strongly on the laser wavelength, pulse shape, intensity, and particularly on the initial vibrational state of the molecule. C1 NATL INST STAND & TECHNOL,GAITHERSBURG,MD 20899. LOUISIANA STATE UNIV,DEPT PHYS,BATON ROUGE,LA 70803. RP Kulander, KC (reprint author), LAWRENCE LIVERMORE NATL LAB,TAMP,LIVERMORE,CA 94551, USA. NR 36 TC 162 Z9 163 U1 1 U2 8 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 1050-2947 J9 PHYS REV A JI Phys. Rev. A PD APR PY 1996 VL 53 IS 4 BP 2562 EP 2570 DI 10.1103/PhysRevA.53.2562 PG 9 WC Optics; Physics, Atomic, Molecular & Chemical SC Optics; Physics GA UE921 UT WOS:A1996UE92100085 ER PT J AU Edwards, M Dodd, RJ Clark, CW Ruprecht, PA Burnett, K AF Edwards, M Dodd, RJ Clark, CW Ruprecht, PA Burnett, K TI Properties of a Bose-Einstein condensate in an anisotropic harmonic potential SO PHYSICAL REVIEW A LA English DT Article AB We present results on the size, density, chemical potential, and lifetime of a Bose-Einstein condensate as a function of the number of condensate atoms for parameters appropriate to the time-averaged orbiting potential trap in which a Bose condensate of Rb-87 atoms was recently formed [M. H. Anderson et al., Science 269, 198 (1995)]. These results were obtained by solving the time-independent nonlinear Schrodinger equation with anisotropic harmonic trapping potential. We also find vortex solutions for the trap and the critical rotation frequency required for their formation. C1 NIST,DIV ELECTRON & OPT PHYS,TECHNOL ADM,US DEPT COMMERCE,GAITHERSBURG,MD 20899. UNIV OXFORD,DEPT PHYS,CLARENDON LAB,OXFORD OX1 3PU,ENGLAND. UNIV MARYLAND,INST PHYS SCI & TECHNOL,COLLEGE PK,MD 20742. RP Edwards, M (reprint author), GEORGIA SO UNIV,DEPT PHYS,STATESBORO,GA 30460, USA. RI Clark, Charles/A-8594-2009; OI Clark, Charles/0000-0001-8724-9885; Edwards, Mark/0000-0002-3149-2402 NR 19 TC 112 Z9 113 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 APR PY 1996 VL 53 IS 4 BP R1950 EP R1953 PG 4 WC Optics; Physics, Atomic, Molecular & Chemical SC Optics; Physics GA UE921 UT WOS:A1996UE92100007 ER PT J AU Williams, CJ Tiesinga, E Julienne, PS AF Williams, CJ Tiesinga, E Julienne, PS TI Hyperfine structure of the Na-2 0(g)(-) long-range molecular state SO PHYSICAL REVIEW A LA English DT Article AB We report a full theoretical calculation of the rovibrational structure of the Na-2 O-g(-) state, including hyperfine structure. The purely long-range O-g(-) state has been observed in the photoassociation spectroscopy of ultracold trapped alkali-metal atoms. For the lighter alkali-metal atoms (Li, Na, and K), the purely long-range states are completely characterized by atomic data since the inner turning point of the potentials are at internuclear separations where exchange interactions are still negligible. C1 UNIV CHICAGO,JAMES FRANCK INST,CHICAGO,IL 60637. EINDHOVEN UNIV TECHNOL,5600 MB EINDHOVEN,NETHERLANDS. RP Williams, CJ (reprint author), NIST,DIV ATOM PHYS,GAITHERSBURG,MD 20899, USA. RI Williams, Carl/B-5877-2009; Julienne, Paul/E-9378-2012 OI Julienne, Paul/0000-0002-5494-1442 NR 24 TC 31 Z9 31 U1 0 U2 0 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 1050-2947 J9 PHYS REV A JI Phys. Rev. A PD APR PY 1996 VL 53 IS 4 BP R1939 EP R1942 PG 4 WC Optics; Physics, Atomic, Molecular & Chemical SC Optics; Physics GA UE921 UT WOS:A1996UE92100004 ER PT J AU Kellogg, GJ Walton, DG Mayes, AM Lambooy, P Russell, TP Gallagher, PD Satija, SK AF Kellogg, GJ Walton, DG Mayes, AM Lambooy, P Russell, TP Gallagher, PD Satija, SK TI Observed surface energy effects in confined diblock copolymers SO PHYSICAL REVIEW LETTERS LA English DT Article ID INDUCED ORIENTATION; BLOCK COPOLYMERS; THIN-FILMS AB By using thin layers of random copolymer, we have varied the specificity of block-wall interactions for films of diblock copolymer confined between parallel walls. For highly specific interactions (bare walls), one block component segregates to both interfaces, and the frustration due to incommensuration between him thickness and the diblock's bulk period is accommodated by the formation of layers parallel to the walls with perturbed period. In contrast, reduced specific interactions (random-copolymer-coated walls) allow the frustration to be accommodated by perpendicular ordering of the diblock, such that both block components are present at the walls. C1 IBM CORP,ALMADEN RES CTR,DIV RES,SAN JOSE,CA 95120. NATL INST STAND & TECHNOL,REACTOR & RADIAT DIV,GAITHERSBURG,MD 20899. RP Kellogg, GJ (reprint author), MIT,DEPT MAT SCI & ENGN,CAMBRIDGE,MA 02139, USA. NR 14 TC 288 Z9 292 U1 7 U2 65 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 0031-9007 J9 PHYS REV LETT JI Phys. Rev. Lett. PD APR 1 PY 1996 VL 76 IS 14 BP 2503 EP 2506 DI 10.1103/PhysRevLett.76.2503 PG 4 WC Physics, Multidisciplinary SC Physics GA UC777 UT WOS:A1996UC77700025 ER PT J AU Ranganathan, S Phelan, FR Advani, SG AF Ranganathan, S Phelan, FR Advani, SG TI A generalized model for the transverse fluid permeability in unidirectional fibrous media SO POLYMER COMPOSITES LA English DT Article ID POROUS-MEDIA; FLOW; CYLINDERS; ARRAYS AB In liquid molding processes such as resin transfer molding (RTM), fluid is injected into a mold filled with fiber reinforcement. The microstructure of the reinforcement strongly influences the resistance it offers to fluid flow. This resistance is characterized by the permeability that determines the ratio between the superficial velocity and the pressure drop in the porous medium. Currently values of the permeability have to be determined experimentally. Therefore, each type of reinforcement has to be characterized before a computer simulation can be used to predict the overall mold filling pattern. A model for predicting the permeability as a function of structure would help reduce the number of experiments needed to determine the input parameters for mold filling simulations. Also, by understanding the physics of the flow through such materials, one may tailor the microstructure such that it has both the desired reinforcing capability and the necessary permeability to fill efficiently. In response to this need, we have developed a predictive semi analytical solution for flow across arrays of aligned cylinders with elliptical cross sections modeling the fiber mats. The shape of the tow, its porosity, and the packing configuration are found to influence the transverse permeability of such an array significantly. Predicted results of the permeability from this model compare very well with numerical results obtained from finite element calculations over a range of volume fractions, cross-sectional shapes, and tow permeabilities. C1 UNIV DELAWARE,DEPT MECH ENGN,NEWARK,DE 19716. RP Ranganathan, S (reprint author), NATL INST STAND & TECHNOL,DIV POLYMERS,GAITHERSBURG,MD 20899, USA. NR 20 TC 65 Z9 67 U1 1 U2 11 PU SOC PLASTICS ENG INC PI BROOKFIELD CENTER PA 14 FAIRFIELD DR, BROOKFIELD CENTER, CT 06804-0403 SN 0272-8397 J9 POLYM COMPOSITE JI Polym. Compos. PD APR PY 1996 VL 17 IS 2 BP 222 EP 230 DI 10.1002/pc.10607 PG 9 WC Materials Science, Composites; Polymer Science SC Materials Science; Polymer Science GA UE925 UT WOS:A1996UE92500007 ER PT J AU Schwab, SD Levy, RL Glover, GG AF Schwab, SD Levy, RL Glover, GG TI Sensor system for monitoring impregnation and cure during resin transfer molding SO POLYMER COMPOSITES LA English DT Article AB In the resin transfer molding (RTM) fabrication of composites, knowledge of the position of a moving resin front during impregnation is important for process optimization. We describe here a simple, inexpensive, multi-point sensor system based on DC conductometry for determination of resin position in an RTM mold. This Resin Position Sensor (RPS) system consists of a matrix of small sensors embedded in the RTM tool, whose combined output can be used to produce a resin flow pattern at any given time after the start of impregnation. As it cures, the resin resistance increases and the sensor can then function as a cure monitor. A large, 24-sensor RTM tool was fabricated for demonstration of the RPS. Flow contour maps generated from sensor data during impregnation of both E-glass and carbon fiber preforms are shown. C1 MCDONNELL DOUGLAS CORP,ST LOUIS,MO 63166. NOAA,SEATTLE,WA 98102. RP Schwab, SD (reprint author), ETHYL RES CTR,RICHMOND,VA 23217, USA. NR 14 TC 23 Z9 23 U1 0 U2 1 PU SOC PLASTICS ENG INC PI BROOKFIELD CENTER PA 14 FAIRFIELD DR, BROOKFIELD CENTER, CT 06804-0403 SN 0272-8397 J9 POLYM COMPOSITE JI Polym. Compos. PD APR PY 1996 VL 17 IS 2 BP 312 EP 316 DI 10.1002/pc.10616 PG 5 WC Materials Science, Composites; Polymer Science SC Materials Science; Polymer Science GA UE925 UT WOS:A1996UE92500016 ER PT J AU Bauer, BJ Liu, DW Jackson, CL Barnes, JD AF Bauer, BJ Liu, DW Jackson, CL Barnes, JD TI Epoxy/SiO2 interpenetrating polymer networks SO POLYMERS FOR ADVANCED TECHNOLOGIES LA English DT Article DE sol-gel; epoxy; interpenetrating polymer network; scattering; transmission electron microscopy ID POLYVINYL METHYL-ETHER); MOLECULAR-WEIGHT; SILICA; TETRAETHOXYSILANE; POLYSTYRENE; COMPOSITES; GLASSES; BLENDS AB We demonstrate a potentially useful method of generating an SiO2 morphology, in situ, with interpenetrating polymer networks (IPN) chemistry. Organic/inorganic IPNs were synthesized with an organic phase made of epoxy resin and an SiO2 phase made by sol-gel chemistry. The two types of polymerization used were sequential and simultaneous with SiO2 content ranging from 0.02 to 0.43 g SiO2/g total weight. The resultant morphologies were examined by small angle X-ray scattering and transmission electron. microscopy. The sequential IPNs were strongly phase separated into a finely divided SiO2 phase of similar to 10 nm size scale. The simultaneous IPNs were weakly phase separated with considerable mixing in the phases. Thermal studies showed increased thermal stability for the IPNs, compared with unfilled epoxies or physically mixed silica filled epoxies. C1 NATL INST STAND & TECHNOL,MAT SCI & ENGN LAB,GAITHERSBURG,MD 20899. OI Jackson, Catheryn/0000-0003-1611-3926 NR 20 TC 32 Z9 32 U1 0 U2 9 PU JOHN WILEY & SONS LTD PI W SUSSEX PA BAFFINS LANE CHICHESTER, W SUSSEX, ENGLAND PO19 1UD SN 1042-7147 J9 POLYM ADVAN TECHNOL JI Polym. Adv. Technol. PD APR PY 1996 VL 7 IS 4 BP 333 EP 339 PG 7 WC Polymer Science SC Polymer Science GA UT984 UT WOS:A1996UT98400018 ER PT J AU Purser, RJ Leslie, LM AF Purser, RJ Leslie, LM TI Generalized Adams-Bashforth time integration schemes for a semi-Lagrangian model employing the second-derivative form of the horizontal momentum equations SO QUARTERLY JOURNAL OF THE ROYAL METEOROLOGICAL SOCIETY LA English DT Article DE numerical techniques; semi-implicit methods; semi-Lagrangian model ID IMPLICIT AB We present a generic class of semi-implicit time-integration methods, the 'Generalized Adams-Bashforth' schemes, for the simultaneous treatment in a semi-Lagrangian model of the equations of horizontal momentum and kinematics in a rotating environment. The salient feature of the approach is that it deals directly with Lagrangian parcel momentum in terms of the parcel's second time-derivative of position. The classical Adams-Bashforth methods can be generalized to accommodate equations of second-derivative form and, as we demonstrate, can be formulated in such a way that the further important refinement of a semi-implicit handling of the fastest gravity modes follows in a natural way. The principal advantages expected of this unified approach over the more conventional separate semi-Lagrangian treatment of kinematics and momentum are: (i) greater economy of storage at a given order of accuracy, (ii) smaller truncation errors at a given order of accuracy. Tests were run with a full-physics three-dimensional regional semi-Lagrangian forecast model applied on a daily basis to archived operational data over a period of three months. Verifications based on the 48 hour forecasts confirm that the expected benefits of the new schemes are also realized in practice. C1 NOAA,NMC,WASHINGTON,DC. UNIV NEW S WALES,KENSINGTON,NSW 2033,AUSTRALIA. NR 33 TC 5 Z9 5 U1 0 U2 1 PU ROYAL METEOROLOGICAL SOC PI READING PA 104 OXFORD ROAD, READING, BERKS, ENGLAND RG1 7LJ SN 0035-9009 J9 Q J ROY METEOR SOC JI Q. J. R. Meteorol. Soc. PD APR PY 1996 VL 122 IS 531 BP 737 EP 763 DI 10.1002/qj.49712253109 PN A PG 27 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA UK530 UT WOS:A1996UK53000008 ER PT J AU Rancic, M Purser, RJ Mesinger, F AF Rancic, M Purser, RJ Mesinger, F TI A global shallow-water model using an expanded spherical cube: Gnomonic versus conformal coordinates SO QUARTERLY JOURNAL OF THE ROYAL METEOROLOGICAL SOCIETY LA English DT Article DE finite differences; numerical weather prediction; quasi-uniform grids; shallow-water equations ID STEP-MOUNTAIN COORDINATE; EQUATIONS; SCHEME AB A model using shallow-water equations with an Arakawa-type scheme for momentum terms is tested on a quasi-uniform geometry on the sphere, derived by a spherical expansion of the inscribed cube based on the gnomonic projection. Thereby, a quasi-homogeneous distribution of grid points is achieved, and a global finite-difference model is designed which does not require Fourier filtering or suffer from the burden of redundant computational points at high latitudes. Difficulties resulting from the directional discontinuity of the coordinate lines crossing the edges of the expanded cube are almost completely eliminated by using the Arakawa B-grid, so that only scalar points are placed along the edges. An alternative approach is developed based on numerical orthogonalization of the grid whereby, inter alia, the directional discontinuity at the edges is avoided at the cost of some accumulation of points in the vicinity of the vertices of the cube. In the customary Rossby-Haurwitz wave-4 tests, both approaches are shown to converge to a visually indistinguishable solution as the resolution is increased. However, with the orthogonalized, conformal grid, convergence towards the asymptotic solution was substantially faster. C1 GEN SCI CORP, LAUREL, MD USA. UNIV CORP ATMOSPHER RES, BOULDER, CO USA. RP Rancic, M (reprint author), NATL CTR ENVIRONM PREDICT, W-NMC2 ROOM 204, 5200 AUTH RD, CAMP SPRINGS, MD 20746 USA. NR 35 TC 115 Z9 116 U1 0 U2 4 PU WILEY-BLACKWELL PI HOBOKEN PA 111 RIVER ST, HOBOKEN 07030-5774, NJ USA SN 0035-9009 EI 1477-870X J9 Q J ROY METEOR SOC JI Q. J. R. Meteorol. Soc. PD APR PY 1996 VL 122 IS 532 BP 959 EP 982 DI 10.1256/smsqj.53208 PN B PG 24 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA UT570 UT WOS:A1996UT57000008 ER PT J AU Cromer, CL Lucatorto, TB OBrian, TR Walhout, M AF Cromer, CL Lucatorto, TB OBrian, TR Walhout, M TI Improved dose metrology in optical lithography SO SOLID STATE TECHNOLOGY LA English DT Article AB Maintaining critical dimensions (CDs) in optical lithography requires careful control over the UV/DUV dose applied to a photoresist, especially as CDs become smaller. To meet the growing need for a UV-measurement infrastructure in the semiconductor industry, the National Institute of Standards and Technology (NIST) is improving its primary radiometric standards by an order of magnitude, reducing the absolute uncertainty in irradiance measurements to about 0.5% in the 100-400-nm range. Parallel improvements in transfer standards and source calibrations will allow the dissemination of highly accurate radiometric scales directly to industry. C1 NATL INST STAND & TECHNOL,DIV ELECTRON & OPT PHYS,GAITHERSBURG,MD 20899. NATL INST STAND & TECHNOL,DIV OPT TECHNOL,SYNCHROTRON RADIOMETRY PROGRAM,GAITHERSBURG,MD 20899. RP Cromer, CL (reprint author), NATL INST STAND & TECHNOL,DIV RADIOMETR PHYS,GAITHERSBURG,MD 20899, USA. NR 11 TC 2 Z9 2 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 APR PY 1996 VL 39 IS 4 BP 75 EP & PG 4 WC Engineering, Electrical & Electronic; Physics, Applied; Physics, Condensed Matter SC Engineering; Physics GA UD831 UT WOS:A1996UD83100018 ER PT J AU Kunkel, G Ono, RH Klushin, AM AF Kunkel, G Ono, RH Klushin, AM TI Millimetre-wave radiation from arrays of high-T-c Josephson junctions SO SUPERCONDUCTOR SCIENCE & TECHNOLOGY LA English DT Article; Proceedings Paper CT 5th International Superconductive Electronics Conference (ISEC 95) CY SEP 18-21, 1995 CL NAGOYA, JAPAN AB We have used a novel high-frequency circuit incorporating a resonant parallel-bias scheme to demonstrate millimetre-wave radiation from arrays of high-temperature superconductor Josephson junctions. The power of a five-junction array was measured with a detector junction on chip, and the Josephson oscillations of a ten-junction array were detected directly with a radiometer from 73 GHz to 123 GHz. C1 NATL INST STAND & TECHNOL,DIV ELECTROMAGNET TECHNOL,BOULDER,CO 80303. RP Kunkel, G (reprint author), INST SCHICHT & IONENTECH,FORSCHUNGSZENTRUM,D-52425 JULICH,GERMANY. NR 8 TC 7 Z9 8 U1 0 U2 2 PU IOP PUBLISHING LTD PI BRISTOL PA TECHNO HOUSE, REDCLIFFE WAY, BRISTOL, ENGLAND BS1 6NX SN 0953-2048 J9 SUPERCOND SCI TECH JI Supercond. Sci. Technol. PD APR PY 1996 VL 9 IS 4A BP A1 EP A4 DI 10.1088/0953-2048/9/4A/002 PG 4 WC Physics, Applied; Physics, Condensed Matter SC Physics GA UF346 UT WOS:A1996UF34600002 ER PT J AU Liang, QF Johnson, LE Yu, YS AF Liang, QF Johnson, LE Yu, YS TI A comparison of two methods for multiobjective optimization for reservoir operation SO WATER RESOURCES BULLETIN LA English DT Article DE multiobjective optimization; water supply; hydropower; stochastic dynamic programming; reliability ID STOCHASTIC INFLOWS; POLICIES; SYSTEM AB Two major objectives in operating the multireservoir system of the Upper Colorado River basin are maximization of hydroelectric power production and maximization of the reliability of annual water supply. These two objectives conflict. Optimal operation of the reservoir system to achieve both is unattainable. This paper seeks the best compromise solution for an aggregated reservoir as a surrogate of the multireservoir system by using two methods: the constraint method and the method of combined stochastic and deterministic modeling. Both methods are used to derive the stationary optimal operating policy for the aggregated reservoir by using stochastic dynamic programming but with different objective functions and minimum monthly release constraints. The resulting operating policies are then used in simulated operation of the reservoir with historical inflow records to evaluate their relative effectiveness. The results show that the policy obtained from the combination method would yield more hydropower production and higher reliability of annual water supply than that from the constraint-method policy. C1 UNIV COLORADO,DEPT CIVIL ENGN,DENVER,CO 80217. UNIV KANSAS,DEPT CIVIL ENGN,LAWRENCE,KS 66045. RP Liang, QF (reprint author), COLORADO STATE UNIV,COOPERAT INST RES ATMOSPHERE,NOAA,FT COLLINS,CO 80523, USA. NR 24 TC 21 Z9 22 U1 0 U2 1 PU AMER WATER RESOURCES ASSOC PI HERNDON PA 950 HERNDON PARKWAY SUITE 300, HERNDON, VA 22070-5528 SN 0043-1370 J9 WATER RESOUR BULL JI Water Resour. Bull. PD APR PY 1996 VL 32 IS 2 BP 333 EP 340 PG 8 WC Engineering, Civil; Geosciences, Multidisciplinary; Water Resources SC Engineering; Geology; Water Resources GA UG715 UT WOS:A1996UG71500012 ER PT J AU Voronovich, AG AF Voronovich, AG TI Non-local small-slope approximation for wave scattering from rough surfaces SO WAVES IN RANDOM MEDIA LA English DT Article AB A new general analytical approach to solving the problems of wave scattering from rough surfaces, referred to as the non-local small-slope approximation (NLSSA), is suggested. It is formulated in the general form both for vector and scalar waves. This approach is valid for an arbitrary wavelength of radiation provided that the slopes of the undulations are small enough. The NLSSA represents a generalization of the small-slope approximation to situations where double scattering (in the optical sense) appears. It is demonstrated that with appropriate approximations the NLSSA of the lowest order reduces to the small-slope approximation of the second order. RP Voronovich, AG (reprint author), UNIV COLORADO,NOAA,COOPERAT INST RES ENVIRONM SCI,ERL,ENVIRONM TECHNOL LAB,325 BROADWAY,BOULDER,CO 80303, USA. NR 13 TC 34 Z9 34 U1 1 U2 2 PU IOP PUBLISHING LTD PI BRISTOL PA TECHNO HOUSE, REDCLIFFE WAY, BRISTOL, ENGLAND BS1 6NX SN 0959-7174 J9 WAVE RANDOM MEDIA JI Waves Random Media PD APR PY 1996 VL 6 IS 2 BP 151 EP 167 DI 10.1088/0959-7174/6/2/005 PG 17 WC Physics, Multidisciplinary SC Physics GA UL801 UT WOS:A1996UL80100005 ER PT J AU Marchiando, JF AF Marchiando, JF TI Application of the collocation method in three dimensions to a model semiconductor problem SO INTERNATIONAL JOURNAL FOR NUMERICAL METHODS IN ENGINEERING LA English DT Article DE boundary value problems; collocation; three-dimensional; Poisson's equation; semiconductor ID PARTIAL-DIFFERENTIAL EQUATIONS; NONLINEAR POISSON EQUATION; SPARSE LINEAR-EQUATIONS; LEAST-SQUARES; ALGORITHM; SOFTWARE; LSQR AB A research code has been written to solve an elliptic system of coupled non-linear partial differential equations of conservation form on a rectangularly shaped three-dimensional domain. The code uses the method of collocation of Gauss points with tricubic Hermite piecewise continuous polynomial basis functions. The system of equations is solved by iteration. The system of non-linear equations is linearized, and the system of linear equations is solved by iterative methods. When the matrix of the collocation equations is duly modified by using a scaled block-limited partial pivoting procedure of Gauss elimination, it is found that the rate of convergence of the iterative method is significantly improved and that a solution becomes possible. The code is used to solve Poisson's equation for a model semiconductor problem. The electric potential distribution is calculated in a metal-oxide-semiconductor structure that is important to the fabrication of electron devices. RP Marchiando, JF (reprint author), NIST,DIV SEMICOND ELECTR,BLDG 225,ROOM A305,ROUTE 270,QUINCE ORCHARD RD,GAITHERSBURG,MD 20899, USA. NR 34 TC 4 Z9 4 U1 0 U2 0 PU JOHN WILEY & SONS LTD PI W SUSSEX PA BAFFINS LANE CHICHESTER, W SUSSEX, ENGLAND PO19 1UD SN 0029-5981 J9 INT J NUMER METH ENG JI Int. J. Numer. Methods Eng. PD MAR 30 PY 1996 VL 39 IS 6 BP 1029 EP 1040 DI 10.1002/(SICI)1097-0207(19960330)39:6<1029::AID-NME893>3.3.CO;2-8 PG 12 WC Engineering, Multidisciplinary; Mathematics, Interdisciplinary Applications SC Engineering; Mathematics GA UD121 UT WOS:A1996UD12100007 ER PT J AU Ridge, KD Lee, SSJ Abdulaev, NG AF Ridge, KD Lee, SSJ Abdulaev, NG TI Examining rhodopsin folding and assembly through expression of polypeptide fragments SO JOURNAL OF BIOLOGICAL CHEMISTRY LA English DT Article ID DOMINANT RETINITIS-PIGMENTOSA; BOVINE RHODOPSIN; MONOCLONAL-ANTIBODIES; TRANSGENIC MICE; SIGNAL SEQUENCE; PROTEINS; GENE; MUTATIONS; MEMBRANES; CHAIN AB Previous work on the expression of bovine opsin fragments separated in the cytoplasmic region has allowed the identification of specific polypeptide segments that contain sufficient information to fold independently, insert into a membrane, and assemble to form a functional photoreceptor. To further examine the contributions of these and other polypeptide segments to the mechanism of opsin folding and assembly, we have constructed 20 additional opsin gene fragments where the points of separation occur in the intradiscal, transmembrane, and cytoplasmic regions. Nineteen of these fragments were stably expressed in COS-1 cells. A five-helix fragment was stably produced only after coexpression with its complementary two-helix fragment. Two fragments composed of the amino-terminal region and the first transmembrane helix were not N-glycosylated and were only partially membrane integrated. One of the singly expressed fragments, which is truncated after the retinal attachment site, bound 11-cis-retinal. Of the coexpressed complementary fragments, only those separated in the second intradiscal and third cytoplasmic regions formed noncovalently linked rhodopsins. Both of these pigments showed reduced transducin activation. Therefore, while many opsin fragments contain enough information to fold and insert into a membrane, only those separated at specific locations assemble to a retinal-binding opsin. C1 UNIV MARYLAND,MARYLAND BIOTECHNOL INST,ROCKVILLE,MD 20850. RP Ridge, KD (reprint author), NATL INST STAND & TECHNOL,CTR ADV RES BIOTECHNOL,BOULDER,CO 80303, USA. FU NEI NIH HHS [EY 11112] NR 61 TC 54 Z9 54 U1 0 U2 0 PU AMER SOC BIOCHEMISTRY MOLECULAR BIOLOGY INC PI BETHESDA PA 9650 ROCKVILLE PIKE, BETHESDA, MD 20814 SN 0021-9258 J9 J BIOL CHEM JI J. Biol. Chem. PD MAR 29 PY 1996 VL 271 IS 13 BP 7860 EP 7867 PG 8 WC Biochemistry & Molecular Biology SC Biochemistry & Molecular Biology GA UC774 UT WOS:A1996UC77400099 PM 8631831 ER PT J AU Overpeck, JT AF Overpeck, JT TI Warm climate surprises SO SCIENCE LA English DT Editorial Material ID GREENLAND ICE CORES; RECORDS; GISP2 RP Overpeck, JT (reprint author), NOAA,NATL GEOPHYS DATA CTR,PALEOCLIMATOL PROGRAM,325 BROADWAY,BOULDER,CO 80303, USA. NR 28 TC 45 Z9 48 U1 1 U2 8 PU AMER ASSOC ADVANCEMENT SCIENCE PI WASHINGTON PA 1200 NEW YORK AVE, NW, WASHINGTON, DC 20005 SN 0036-8075 J9 SCIENCE JI Science PD MAR 29 PY 1996 VL 271 IS 5257 BP 1820 EP 1821 DI 10.1126/science.271.5257.1820 PG 2 WC Multidisciplinary Sciences SC Science & Technology - Other Topics GA UC778 UT WOS:A1996UC77800030 ER PT J AU Karl, TR Jones, PD Knight, RW AF Karl, TR Jones, PD Knight, RW TI Testing for bias in the climate record SO SCIENCE LA English DT Article C1 UNIV E ANGLIA,CLIMAT RES UNIT,NORWICH NR4 7TJ,NORFOLK,ENGLAND. RP Karl, TR (reprint author), NOAA,NATL CLIMATE DATA CTR,ASHEVILLE,NC 28801, USA. RI Jones, Philip/C-8718-2009 OI Jones, Philip/0000-0001-5032-5493 NR 4 TC 7 Z9 7 U1 0 U2 0 PU AMER ASSOC ADVANCEMENT SCIENCE PI WASHINGTON PA 1200 NEW YORK AVE, NW, WASHINGTON, DC 20005 SN 0036-8075 J9 SCIENCE JI Science PD MAR 29 PY 1996 VL 271 IS 5257 BP 1879 EP 1880 DI 10.1126/science.271.5257.1879 PG 2 WC Multidisciplinary Sciences SC Science & Technology - Other Topics GA UC778 UT WOS:A1996UC77800051 ER PT J AU Craig, NC Abiog, OP Hu, B Stone, SC Lafferty, WJ Xu, LH AF Craig, NC Abiog, OP Hu, B Stone, SC Lafferty, WJ Xu, LH TI Complete structure of trans-1,2-difluoroethylene from the analysis of high-resolution infrared spectra SO JOURNAL OF PHYSICAL CHEMISTRY LA English DT Article ID 1,2-DIFLUOROETHANE AB For comparison to the structure of the cis isomer with its puzzlingly lower energy, the complete structure of trans-1,2-difluoroethylene, a nonpolar molecule, has been determined. High-resolution infrared spectra have been recorded for three isotopomers, the C-13(2), d(2), and d(1) species. From the analysis of at least two band types for each isotopomer, a Watson-type Hamiltonian has been fit to ground state combination differences. Ground state rotational constants (in cm(-1)) are A = 1.8247501(32), B = 0.13396608(66), and C = 0.12473595(65) for the C-13(2) species, A = 1.2634959(27), B = 0.13403712(61), and C = 0.12110234(59) for the d(2) species, and A = 1.5198818(34), B = 0.13429738(50), and C = 0.12331713(54) for the d(1) species. From these constants and those previously published for the normal species, substitution coordinates have been found for the carbon and hydrogen atoms and effective coordinates have been found for the fluorine atoms. The resulting parameters are r(CH) = 1.080 Angstrom, r(CC) = 1.316 Angstrom, r(CF) = 1.352 Angstrom, alpha(CCH) = 126.3 degrees, and alpha(CCF) = 119.2 degrees. The most significant differences from the cis isomer are the 2.9 degrees smaller CCF angle and the 2.4 degrees larger CCH angle for the trans isomer. These differences correlate with a larger repulsion of CF bond dipoles in the cis isomer than in the trans isomer despite the lower energy of the cis isomer. In addition, the CF bond length is 0.015 Angstrom longer and both the CC and CH bonds are somewhat shorter in the trans isomer. The synthesis of trans-1,2-difluoroethylene-C-13(2) is described, and various intermediates are identified. C1 OBERLIN COLL,DEPT CHEM,OBERLIN,OH 44074. NATL INST STAND & TECHNOL,DIV MOLEC PHYS,GAITHERSBURG,MD 20899. RI Xu, Li-Hong/J-5095-2015 NR 27 TC 32 Z9 32 U1 2 U2 2 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 SN 0022-3654 J9 J PHYS CHEM-US JI J. Phys. Chem. PD MAR 28 PY 1996 VL 100 IS 13 BP 5310 EP 5317 DI 10.1021/jp953310q PG 8 WC Chemistry, Physical SC Chemistry GA UC398 UT WOS:A1996UC39800024 ER PT J AU Rudich, Y Talukdar, RK Fox, RW Ravishankara, AR AF Rudich, Y Talukdar, RK Fox, RW Ravishankara, AR TI Rate coefficients for reactions of NO3 with a few olefins and oxygenated olefins SO JOURNAL OF PHYSICAL CHEMISTRY LA English DT Article ID GAS-PHASE REACTIONS; ORGANIC-COMPOUNDS; ATOMIC OXYGEN; HYDROCARBONS; PHOTODETACHMENT; KINETICS; PRODUCTS AB The rate coefficients for the reactions of NO3 with 2-methyl-3-bulene-2-ol (methyl butenol, MBO, k(1)), 1-butene (k(2)), trans-2-butene (k(3)), methacrolein (MACR, k(4)), and methyl vinyl ketone (MVK, k(5)) were measured directly using a flow tube coupled to a diode laser absorption system where NO3 was measured. The measured values of the rate coefficients are k(1) = 4.6 x 10(-14) exp(-400/T) cm(3) molecule(-1) s(-1), k(2) = 5.2 x 10(-13) exp(-1070/T) cm(3) molecule(-1) s(-1), k(3)(298 K) = (4.06 +/- 0.36) x 10(-13) cm(3) molecule(-1) s(-1), k(4)(298 K) less than or equal to 8 x 10(-15) cm(3) molecule(-1) s(-1), and k(5)(298 K) less than or equal to 1.2 x 10(-16) cm(3) molecule(-1) s(-1). The observed reactivity trends are correlated in terms of the presence of electron-withdrawing substituents, which reduces the reactivity of alkenes toward NO3 addition to the double bond. The contribution of NO3 reactions to determining the tropospheric lifetimes of these compounds are also calculated. C1 NOAA,AERON LAB,BOULDER,CO 80303. UNIV COLORADO,COOPERAT INST RES ENVIRONM SCI,BOULDER,CO 80309. UNIV COLORADO,DEPT CHEM & BIOCHEM,BOULDER,CO 80303. RI Rudich, Yinon/K-1498-2012; TALUKDAR, RANAJIT/G-4530-2013; Ravishankara, Akkihebbal/A-2914-2011; OI TALUKDAR, RANAJIT/0000-0001-6017-8431; Rudich, Yinon/0000-0003-3149-0201 NR 33 TC 46 Z9 46 U1 1 U2 6 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 SN 0022-3654 J9 J PHYS CHEM-US JI J. Phys. Chem. PD MAR 28 PY 1996 VL 100 IS 13 BP 5374 EP 5381 DI 10.1021/jp953079g PG 8 WC Chemistry, Physical SC Chemistry GA UC398 UT WOS:A1996UC39800033 ER PT J AU Zhou, SJ Lomdahl, PS Thomson, R Holian, BL AF Zhou, SJ Lomdahl, PS Thomson, R Holian, BL TI Dynamic crack processes via molecular dynamics SO PHYSICAL REVIEW LETTERS LA English DT Article ID FRACTURE; INSTABILITY AB From large-scale molecular-dynamics simulations of dynamic crack propagation, we find that cracks accelerate quickly to a relatively steady velocity. Energy released by bond breaking accumulates in a local phonon field that moves with the crack tip and promotes the emission of dislocations. Branching follows dislocation emission along a slip plane. The branching instability requires the crack to achieve a critical velocity, as well as an induction time for energy buildup at the crack tip. C1 LOS ALAMOS NATL LAB,CTR NONLINEAR STUDIES,LOS ALAMOS,NM 87545. NATL INST STAND & TECHNOL,MAT SCI & ENGN LAB,GAITHERSBURG,MD 20899. RP Zhou, SJ (reprint author), LOS ALAMOS NATL LAB,DIV THEORET,LOS ALAMOS,NM 87545, USA. NR 12 TC 100 Z9 101 U1 1 U2 15 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 0031-9007 J9 PHYS REV LETT JI Phys. Rev. Lett. PD MAR 25 PY 1996 VL 76 IS 13 BP 2318 EP 2321 DI 10.1103/PhysRevLett.76.2318 PG 4 WC Physics, Multidisciplinary SC Physics GA UB148 UT WOS:A1996UB14800028 ER PT J AU Wong, LS Reipa, V Vilker, V Yap, W AF Wong, LS Reipa, V Vilker, V Yap, W TI Development of a novel bioconversion process based on a P450(CAM) subsystem driven by an electrode instead of NADH SO ABSTRACTS OF PAPERS OF THE AMERICAN CHEMICAL SOCIETY LA English DT Meeting Abstract C1 NIST,GAITHERSBURG,MD 20899. NR 0 TC 0 Z9 0 U1 0 U2 1 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 SN 0065-7727 J9 ABSTR PAP AM CHEM S JI Abstr. Pap. Am. Chem. Soc. PD MAR 24 PY 1996 VL 211 BP 13 EP BIOT PN 1 PG 1 WC Chemistry, Multidisciplinary SC Chemistry GA UA482 UT WOS:A1996UA48200475 ER PT J AU Holden, MJ Coxon, B Vilker, VL AF Holden, MJ Coxon, B Vilker, VL TI Stable isotope labeling of expressed proteins for nmr studies SO ABSTRACTS OF PAPERS OF THE AMERICAN CHEMICAL SOCIETY LA English DT Meeting Abstract C1 NATL INST STAND & TECHNOL,DIV BIOTECHNOL,GAITHERSBURG,MD 20899. NR 0 TC 0 Z9 0 U1 0 U2 0 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 SN 0065-7727 J9 ABSTR PAP AM CHEM S JI Abstr. Pap. Am. Chem. Soc. PD MAR 24 PY 1996 VL 211 BP 18 EP BIOT PN 1 PG 1 WC Chemistry, Multidisciplinary SC Chemistry GA UA482 UT WOS:A1996UA48200480 ER PT J AU Pommersheim, JM Nguyen, T Hartzfeld, KA AF Pommersheim, JM Nguyen, T Hartzfeld, KA TI Prediction of blistering in coating systems SO ABSTRACTS OF PAPERS OF THE AMERICAN CHEMICAL SOCIETY LA English DT Meeting Abstract C1 BUCKNELL UNIV,DEPT CHEM ENGN,LEWISBURG,PA 17837. NIST,BLDG & FIRE RES LAB,GAITHERSBURG,MD 20899. NR 0 TC 0 Z9 1 U1 1 U2 1 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 SN 0065-7727 J9 ABSTR PAP AM CHEM S JI Abstr. Pap. Am. Chem. Soc. PD MAR 24 PY 1996 VL 211 BP 25 EP PMSE PN 2 PG 1 WC Chemistry, Multidisciplinary SC Chemistry GA UA485 UT WOS:A1996UA48501680 ER PT J AU Vilker, V AF Vilker, V TI Electrode driven biocatalytic cycle SO ABSTRACTS OF PAPERS OF THE AMERICAN CHEMICAL SOCIETY LA English DT Meeting Abstract C1 NIST,DIV BIOTECHNOL,GAITHERSBURG,MD 20899. NR 0 TC 0 Z9 0 U1 0 U2 0 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 SN 0065-7727 J9 ABSTR PAP AM CHEM S JI Abstr. Pap. Am. Chem. Soc. PD MAR 24 PY 1996 VL 211 BP 27 EP BIOT PN 1 PG 1 WC Chemistry, Multidisciplinary SC Chemistry GA UA482 UT WOS:A1996UA48200489 ER PT J AU Murphy, PP Feely, RA Byrne, RH AF Murphy, PP Feely, RA Byrne, RH TI Uncertainties in thermodynamic model predictions for the carbonate system in sea water. SO ABSTRACTS OF PAPERS OF THE AMERICAN CHEMICAL SOCIETY LA English DT Meeting Abstract C1 NOAA,PACIFIC MARINE ENVIRONM LAB,SEATTLE,WA 98115. UNIV S FLORIDA,DEPT MARINE SCI,ST PETERSBURG,FL 33701. NR 0 TC 0 Z9 0 U1 0 U2 0 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 SN 0065-7727 J9 ABSTR PAP AM CHEM S JI Abstr. Pap. Am. Chem. Soc. PD MAR 24 PY 1996 VL 211 BP 38 EP GEOC PN 1 PG 1 WC Chemistry, Multidisciplinary SC Chemistry GA UA482 UT WOS:A1996UA48202704 ER PT J AU Terashima, N Atalla, RH VanderHart, DL AF Terashima, N Atalla, RH VanderHart, DL TI Solid state NMR of specifically 13C-enriched lignin in wheat straw SO ABSTRACTS OF PAPERS OF THE AMERICAN CHEMICAL SOCIETY LA English DT Meeting Abstract C1 USDA,FOREST PROD LAB,MADISON,WI 53705. NATL INST STAND & TECHNOL,US DC,GAITHERSBURG,MD 20899. NR 0 TC 0 Z9 0 U1 1 U2 3 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 SN 0065-7727 J9 ABSTR PAP AM CHEM S JI Abstr. Pap. Am. Chem. Soc. PD MAR 24 PY 1996 VL 211 BP 41 EP CELL PN 1 PG 1 WC Chemistry, Multidisciplinary SC Chemistry GA UA482 UT WOS:A1996UA48200819 ER PT J AU Grubbs, WT Dougherty, TP Heilweil, EJ AF Grubbs, WT Dougherty, TP Heilweil, EJ TI Bimolecular interactions in (Et)(3)SiOH:BASE:CC4 hydrogen-bonded solutions studied by deactivation of the ''free'' OH-stretch vibration SO ABSTRACTS OF PAPERS OF THE AMERICAN CHEMICAL SOCIETY LA English DT Meeting Abstract C1 NATL INST STAND & TECHNOL,DIV MOLEC PHYS,GAITHERSBURG,MD 20899. NR 0 TC 0 Z9 0 U1 0 U2 0 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 SN 0065-7727 J9 ABSTR PAP AM CHEM S JI Abstr. Pap. Am. Chem. Soc. PD MAR 24 PY 1996 VL 211 BP 55 EP PHYS PN 2 PG 1 WC Chemistry, Multidisciplinary SC Chemistry GA UA485 UT WOS:A1996UA48500983 ER PT J AU Sung, L Karim, A Douglas, JF Han, CC AF Sung, L Karim, A Douglas, JF Han, CC TI Phase separation in thin film polymer blends with and without block copolymer additives SO ABSTRACTS OF PAPERS OF THE AMERICAN CHEMICAL SOCIETY LA English DT Meeting Abstract C1 NIST,DIV POLYMERS,GAITHERSBURG,MD 20899. NR 0 TC 0 Z9 0 U1 0 U2 3 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 SN 0065-7727 J9 ABSTR PAP AM CHEM S JI Abstr. Pap. Am. Chem. Soc. PD MAR 24 PY 1996 VL 211 BP 59 EP PMSE PN 2 PG 1 WC Chemistry, Multidisciplinary SC Chemistry GA UA485 UT WOS:A1996UA48501714 ER PT J AU Dickerson, RR Kelley, P AF Dickerson, RR Kelley, P TI Measurements of reactive nitrogen compounds over the Indian Ocean SO ABSTRACTS OF PAPERS OF THE AMERICAN CHEMICAL SOCIETY LA English DT Meeting Abstract C1 UNIV MARYLAND,DEPT METEOROL,COLLEGE PK,MD 20742. UNIV MARYLAND,DEPT CHEM,COLLEGE PK,MD 20742. NOAA,ATLANTIC OCEANOG & METEOROL LAB,MIAMI,FL 33149. MAX PLANCK INST,MAINZ,GERMANY. RI Dickerson, Russell/F-2857-2010; Kelley, Paul/C-9155-2016 OI Dickerson, Russell/0000-0003-0206-3083; NR 0 TC 0 Z9 0 U1 0 U2 0 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 SN 0065-7727 J9 ABSTR PAP AM CHEM S JI Abstr. Pap. Am. Chem. Soc. PD MAR 24 PY 1996 VL 211 BP 61 EP ENVR PN 1 PG 1 WC Chemistry, Multidisciplinary SC Chemistry GA UA482 UT WOS:A1996UA48202422 ER PT J AU Struck, LM Buntin, SA Richter, LJ Cavanagh, RR Stephenson, JC AF Struck, LM Buntin, SA Richter, LJ Cavanagh, RR Stephenson, JC TI Femtosecond desorption of CO from Cu(100): State resolved test of ultrafast desorption models. SO ABSTRACTS OF PAPERS OF THE AMERICAN CHEMICAL SOCIETY LA English DT Meeting Abstract C1 NIST,GAITHERSBURG,MD 20899. RI Richter, Lee/N-7730-2016 OI Richter, Lee/0000-0002-9433-3724 NR 0 TC 0 Z9 0 U1 0 U2 0 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 SN 0065-7727 J9 ABSTR PAP AM CHEM S JI Abstr. Pap. Am. Chem. Soc. PD MAR 24 PY 1996 VL 211 BP 99 EP PHYS PN 2 PG 1 WC Chemistry, Multidisciplinary SC Chemistry GA UA485 UT WOS:A1996UA48501028 ER PT J AU Eganhouse, RP Dorsey, TF Phinney, CS AF Eganhouse, RP Dorsey, TF Phinney, CS TI Factors controlling the fate of petroleum hydrocarbons in a sand and gravel aquifer. SO ABSTRACTS OF PAPERS OF THE AMERICAN CHEMICAL SOCIETY LA English DT Meeting Abstract C1 US GEOL SURVEY,RESTON,VA 22092. US GEOL SURVEY,NWQL,DENVER,CO 80225. NIST,GAITHERSBURG,MD 20899. SCCWRP,WESTMINSTER,CA 92683. NR 0 TC 0 Z9 0 U1 0 U2 1 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 SN 0065-7727 J9 ABSTR PAP AM CHEM S JI Abstr. Pap. Am. Chem. Soc. PD MAR 24 PY 1996 VL 211 BP 109 EP ENVR PN 1 PG 1 WC Chemistry, Multidisciplinary SC Chemistry GA UA482 UT WOS:A1996UA48202470 ER PT J AU Rudich, Y Talukdar, RK Fox, R Imamura, T Ravishankara, AR AF Rudich, Y Talukdar, RK Fox, R Imamura, T Ravishankara, AR TI Heterogeneous chemistry of NO3 in clouds and fogs. SO ABSTRACTS OF PAPERS OF THE AMERICAN CHEMICAL SOCIETY LA English DT Meeting Abstract C1 NOAA,AERON LAB,BOULDER,CO 80303. RI Rudich, Yinon/K-1498-2012 NR 0 TC 0 Z9 0 U1 0 U2 0 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 SN 0065-7727 J9 ABSTR PAP AM CHEM S JI Abstr. Pap. Am. Chem. Soc. PD MAR 24 PY 1996 VL 211 BP 122 EP ANYL PN 1 PG 1 WC Chemistry, Multidisciplinary SC Chemistry GA UA482 UT WOS:A1996UA48200389 ER PT J AU Krauss, M Osman, R AF Krauss, M Osman, R TI Energy surfaces of the ethenyl peroxyl radical. SO ABSTRACTS OF PAPERS OF THE AMERICAN CHEMICAL SOCIETY LA English DT Meeting Abstract C1 NIST,CTR ADV RES BIOTECHNOL,ROCKVILLE,MD 20850. MT SINAI SCH MED,DEPT PHYS & BIOPHYS,NEW YORK,NY 10029. NR 0 TC 0 Z9 0 U1 0 U2 0 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 SN 0065-7727 J9 ABSTR PAP AM CHEM S JI Abstr. Pap. Am. Chem. Soc. PD MAR 24 PY 1996 VL 211 BP 135 EP COMP PN 1 PG 2 WC Chemistry, Multidisciplinary SC Chemistry GA UA482 UT WOS:A1996UA48202326 ER PT J AU Murphy, DM AF Murphy, DM TI Field measurements of single particle composition SO ABSTRACTS OF PAPERS OF THE AMERICAN CHEMICAL SOCIETY LA English DT Meeting Abstract C1 NOAA,AERON LAB,BOULDER,CO 80303. NR 0 TC 0 Z9 0 U1 0 U2 0 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 SN 0065-7727 J9 ABSTR PAP AM CHEM S JI Abstr. Pap. Am. Chem. Soc. PD MAR 24 PY 1996 VL 211 BP 158 EP ANYL PN 1 PG 1 WC Chemistry, Multidisciplinary SC Chemistry GA UA482 UT WOS:A1996UA48200425 ER PT J AU Coe, CG Gaffney, TR Kirner, JF Klotz, HC MacDougall, JE Toby, BH AF Coe, CG Gaffney, TR Kirner, JF Klotz, HC MacDougall, JE Toby, BH TI Cation and framework influences on N-2 adsorption. SO ABSTRACTS OF PAPERS OF THE AMERICAN CHEMICAL SOCIETY LA English DT Meeting Abstract C1 AIR PROD & CHEM INC,ALLENTOWN,PA 18195. NIST,GAITHERSBURG,MD 20899. RI Toby, Brian/F-3176-2013 OI Toby, Brian/0000-0001-8793-8285 NR 0 TC 0 Z9 0 U1 0 U2 1 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 SN 0065-7727 J9 ABSTR PAP AM CHEM S JI Abstr. Pap. Am. Chem. Soc. PD MAR 24 PY 1996 VL 211 BP 186 EP PHYS PN 2 PG 1 WC Chemistry, Multidisciplinary SC Chemistry GA UA485 UT WOS:A1996UA48501116 ER PT J AU Irikura, KK AF Irikura, KK TI Ab initio prediction of relative two-photon and three-photon absorption strengths. SO ABSTRACTS OF PAPERS OF THE AMERICAN CHEMICAL SOCIETY LA English DT Meeting Abstract C1 NIST,DIV CHEM KINET & THERMODYNAM,GAITHERSBURG,MD 20899. RI Irikura, Karl/A-4266-2009 OI Irikura, Karl/0000-0001-7515-6761 NR 0 TC 0 Z9 0 U1 0 U2 0 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 SN 0065-7727 J9 ABSTR PAP AM CHEM S JI Abstr. Pap. Am. Chem. Soc. PD MAR 24 PY 1996 VL 211 BP 192 EP PHYS PN 2 PG 1 WC Chemistry, Multidisciplinary SC Chemistry GA UA485 UT WOS:A1996UA48501122 ER PT J AU Nadal, MF Kleiber, PD Lineberger, WC AF Nadal, MF Kleiber, PD Lineberger, WC TI Photofragmentation studies of mass-selected ICl(CO2)(n) cluster ions: Solvation effects on the structure and dynamics of the ionic chromophore. SO ABSTRACTS OF PAPERS OF THE AMERICAN CHEMICAL SOCIETY LA English DT Meeting Abstract C1 UNIV COLORADO,DEPT CHEM & BIOCHEM,BOULDER,CO 80309. UNIV COLORADO,JOINT INST LAB ASTROPHYS,BOULDER,CO 80309. NATL INST STAND & TECHNOL,BOULDER,CO 80309. NR 0 TC 0 Z9 0 U1 1 U2 1 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 SN 0065-7727 J9 ABSTR PAP AM CHEM S JI Abstr. Pap. Am. Chem. Soc. PD MAR 24 PY 1996 VL 211 BP 199 EP PHYS PN 2 PG 1 WC Chemistry, Multidisciplinary SC Chemistry GA UA485 UT WOS:A1996UA48501129 ER PT J AU Schen, M Mopsik, FI Wu, W Wallace, WE Tan, NCB Davis, GT Guthrie, W AF Schen, M Mopsik, FI Wu, W Wallace, WE Tan, NCB Davis, GT Guthrie, W TI Advances in the measurement of polymer CTE: Atomic- to micrometer-scale measurements SO ABSTRACTS OF PAPERS OF THE AMERICAN CHEMICAL SOCIETY LA English DT Meeting Abstract C1 NIST,MAT SCI & ENGN LAB,GAITHERSBURG,MD 20899. NIST,COMP & APPL MATH LAB,GAITHERSBURG,MD 20899. NR 0 TC 0 Z9 0 U1 0 U2 1 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 SN 0065-7727 J9 ABSTR PAP AM CHEM S JI Abstr. Pap. Am. Chem. Soc. PD MAR 24 PY 1996 VL 211 BP 218 EP POLY PN 2 PG 1 WC Chemistry, Multidisciplinary SC Chemistry GA UA485 UT WOS:A1996UA48501445 ER PT J AU Lukehart, CM Milne, SB Wittig, JE Stock, SR Shull, RD AF Lukehart, CM Milne, SB Wittig, JE Stock, SR Shull, RD TI Novel synthetic routes to nanocomposites of transition metal phosphides. SO ABSTRACTS OF PAPERS OF THE AMERICAN CHEMICAL SOCIETY LA English DT Meeting Abstract C1 VANDERBILT UNIV,DEPT CHEM,NASHVILLE,TN 37235. VANDERBILT UNIV,DEPT APPL & ENGN SCI,NASHVILLE,TN 37235. GEORGIA INST TECHNOL,SCH MAT SCI & ENGN,ATLANTA,GA 30332. NATL INST STAND & TECHNOL,GAITHERSBURG,MD 20899. RI Shull, Robert/F-5971-2013 NR 0 TC 0 Z9 0 U1 0 U2 1 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 SN 0065-7727 J9 ABSTR PAP AM CHEM S JI Abstr. Pap. Am. Chem. Soc. PD MAR 24 PY 1996 VL 211 BP 281 EP INOR PN 1 PG 1 WC Chemistry, Multidisciplinary SC Chemistry GA UA482 UT WOS:A1996UA48203301 ER PT J AU Guttman, CM AF Guttman, CM TI The relationship between the signals from size exclusion chromatography and time of flight mass spectrometry to a polymer molecular weight distribution. SO ABSTRACTS OF PAPERS OF THE AMERICAN CHEMICAL SOCIETY LA English DT Meeting Abstract C1 NIST,DIV POLYMERS,GAITHERSBURG,MD 20899. NR 0 TC 0 Z9 0 U1 0 U2 0 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 SN 0065-7727 J9 ABSTR PAP AM CHEM S JI Abstr. Pap. Am. Chem. Soc. PD MAR 24 PY 1996 VL 211 BP 322 EP POLY PN 2 PG 1 WC Chemistry, Multidisciplinary SC Chemistry GA UA485 UT WOS:A1996UA48501549 ER PT J AU Feng, Y Weiss, RA Karim, A Han, CC Ankner, JF Peiffer, DG AF Feng, Y Weiss, RA Karim, A Han, CC Ankner, JF Peiffer, DG TI Kinetics of mixing at a polymer-polymer interface capable of forming an intermolecular complex SO ABSTRACTS OF PAPERS OF THE AMERICAN CHEMICAL SOCIETY LA English DT Meeting Abstract C1 UNIV CONNECTICUT,INST MAT SCI,STORRS,CT 06269. NIST,DIV POLYMER,GAITHERSBURG,MD 20899. UNIV MISSOURI,REACTOR RES FACIL,COLUMBIA,MO 65211. EXXON RES & ENGN CO,CLINTON,NJ 08801. NR 0 TC 0 Z9 0 U1 0 U2 1 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 SN 0065-7727 J9 ABSTR PAP AM CHEM S JI Abstr. Pap. Am. Chem. Soc. PD MAR 24 PY 1996 VL 211 BP 330 EP POLY PN 2 PG 1 WC Chemistry, Multidisciplinary SC Chemistry GA UA485 UT WOS:A1996UA48501557 ER PT J AU Bauer, BJ Liu, DW AF Bauer, BJ Liu, DW TI Compatibliizers made from block copolymers that have strong specific interactions SO ABSTRACTS OF PAPERS OF THE AMERICAN CHEMICAL SOCIETY LA English DT Meeting Abstract C1 NIST,MAT SCI & ENGN LAB,GAITHERSBURG,MD 20899. NR 0 TC 0 Z9 0 U1 0 U2 0 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 SN 0065-7727 J9 ABSTR PAP AM CHEM S JI Abstr. Pap. Am. Chem. Soc. PD MAR 24 PY 1996 VL 211 BP 367 EP POLY PN 2 PG 1 WC Chemistry, Multidisciplinary SC Chemistry GA UA485 UT WOS:A1996UA48501594 ER PT J AU Gettinger, CL Jackson, CL Han, CC AF Gettinger, CL Jackson, CL Han, CC TI Micelles formed by a model ionic graft copolymer SO ABSTRACTS OF PAPERS OF THE AMERICAN CHEMICAL SOCIETY LA English DT Meeting Abstract C1 NIST,DIV POLYMERS,GAITHERSBURG,MD 20899. UNIV ALABAMA,DEPT CHEM,BIRMINGHAM,AL 35292. NR 0 TC 0 Z9 0 U1 0 U2 0 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 SN 0065-7727 J9 ABSTR PAP AM CHEM S JI Abstr. Pap. Am. Chem. Soc. PD MAR 24 PY 1996 VL 211 BP 385 EP POLY PN 2 PG 1 WC Chemistry, Multidisciplinary SC Chemistry GA UA485 UT WOS:A1996UA48501612 ER PT J AU Xi, D Kurtz, DT Ramsdell, JS AF Xi, D Kurtz, DT Ramsdell, JS TI Maitotoxin-elevated cytosolic free calcium in GH(4)C(1) rat pituitary cells nimodipine-sensitive and -insensitive mechanisms SO BIOCHEMICAL PHARMACOLOGY LA English DT Article DE maitotoxin; L-VDCC; intracellular Ca2+; membrane depolarization; ionic conductances ID PHOSPHOINOSITIDE BREAKDOWN; CHANNELS; SYNAPTOSOMES; ACTIVATOR; CHLORIDE; ENTRY AB Maitotoxin induces an extracellular Ca2+-dependent membrane depolarization predominantly via activation of L-type voltage-dependent Ca2+ channels (L-VDCC) in GH(4)C(1) rat pituitary cells. In contrast to studies employing intracellular dyes, electrophysiological studies have indicated that maitotoxin activates voltage-independent conductances. In the present study, we used fura-2 calcium digital analysis to investigate the actions of very low concentrations of maitotoxin on cytosolic free calcium ([Ca2+](i)) in GH(4)C(1) cells in an effort to distinguish different calcium entry mechanisms. Maitotoxin at concentrations as low as 0.01 ng/mL elevated [Ca2+](i) 35 +/- 3% and induced membrane depolarization. The concentration dependency for maitotoxin-elevated [Ca2+](i) was biphasic with the first phase maximal at 0.05 to 0.5 ng/mL and the minimum EC(50) of the second phase about 2.0 ng/ml. Nimodipine (100 nM), a dihydropyridine antagonist of L-VDCC, prevented the [Ca2+](i) increase and depolarization induced by up to 0.1 ng/mL maitotoxin, but not at higher concentrations (0.5 ng/mL) of maitotoxin. This indicates that lower concentrations (0.1 ng/mL) of maitotoxin require L-VDCC, whereas higher concentrations (greater than or equal to 0.5 ng/mL) of maitotoxin may require additional ionic mechanisms. Maitotoxin (0.5 ng/mL) induced Ca-45(2+) uptake and depolarization in L(tk-) cells which lack VDCC. Reducing extracellular Cl- from 123 to 5.8 mM increased the magnitude of membrane depolarization by maitotoxin (0.5 ng/mL), which suggests that a Cl- conductance participates in depolarization induced by higher maitotoxin concentrations. Taken together, our results indicate that maitotoxin activates at least two ionic mechanisms. At lower concentrations of maitotoxin, the primary ionic mechanism requires the activation of L-VDCC; however, at higher maitotoxin concentrations, additional ionic mechanisms are involved in the entry of extracellular Ca2+. This latter mechanism may represent the voltage-independent pathway evident under voltage clamp conditions. C1 MED UNIV S CAROLINA, DEPT MOLEC & CELLULAR PHARMACOL, CHARLESTON, SC 29412 USA. NATL MARINE FISHERIES SERV, MARINE BIOTOXINS PROGRAM, CHARLESTON, SC 29412 USA. FU NIDDK NIH HHS [DK 43107] NR 24 TC 10 Z9 10 U1 1 U2 2 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLAND SN 0006-2952 J9 BIOCHEM PHARMACOL JI Biochem. Pharmacol. PD MAR 22 PY 1996 VL 51 IS 6 BP 759 EP 769 DI 10.1016/0006-2952(95)02392-5 PG 11 WC Pharmacology & Pharmacy SC Pharmacology & Pharmacy GA TZ107 UT WOS:A1996TZ10700006 PM 8602871 ER PT J AU Pearson, J Dixon, RN Hudgens, JW Johnson, RD AF Pearson, J Dixon, RN Hudgens, JW Johnson, RD TI Resonance enhanced multiphoton ionization spectroscopy of the SnF radical SO JOURNAL OF CHEMICAL PHYSICS LA English DT Article AB The resonance enhanced multiphoton ionization spectrum of the free radical SnF has been recorded using excitation wavelengths in the range 540 to 360 nm. The previously documented C2 Delta, D, E(2)II, and F-2 Sigma(+) states and two hitherto unidentified excited states, the H and I-2 Phi, states, were all observed as two-photon resonances. Band contour simulations yielded spectroscopic constants for the E, F, and I states. (C) 1996 American Institute of Physics. C1 NATL INST STAND & TECHNOL,CHEM SCI & TECHNOL LAB,DIV CHEM KINET & THERMODYNAM,GAITHERSBURG,MD 20899. RP Pearson, J (reprint author), UNIV BRISTOL,SCH CHEM,CANTOCKS CLOSE,BRISTOL BS8 1TS,AVON,ENGLAND. NR 13 TC 0 Z9 0 U1 0 U2 2 PU AMER INST PHYSICS PI WOODBURY PA CIRCULATION FULFILLMENT DIV, 500 SUNNYSIDE BLVD, WOODBURY, NY 11797-2999 SN 0021-9606 J9 J CHEM PHYS JI J. Chem. Phys. PD MAR 22 PY 1996 VL 104 IS 12 BP 4406 EP 4410 DI 10.1063/1.471192 PG 5 WC Chemistry, Physical; Physics, Atomic, Molecular & Chemical SC Chemistry; Physics GA UA381 UT WOS:A1996UA38100007 ER PT J AU Opansky, BJ Leone, SR AF Opansky, BJ Leone, SR TI Low-temperature rate coefficients of C2H with CH4 and CD4 from 154 to 359 K SO JOURNAL OF PHYSICAL CHEMISTRY LA English DT Article ID RATE CONSTANTS; PHOTODISSOCIATION; PHOTOCHEMISTRY; ATMOSPHERE; DEPENDENCE; ACETYLENE; TITAN; NM; D2 AB Rate coefficients for the reaction C2H + CH4 --> C2H2 + CH3 and C2H + CD4 --> C2HD + CD3 are measured over the temperature range 154-359 K using transient infrared laser absorption spectroscopy. Ethynyl radicals are produced by pulsed laser photolysis of C2H2 in a variable temperature flow cell, and a tunable color center laser probes the transient removal of C2H (X(2) Sigma(+) (0,0,0)) in absorption. The rate coefficients for the reactions of C2H with CH4 and CD4 both show a positive temperature dependence over the range 154-359 K, which can be expressed as k(CH4) = (1.2 +/- 0.1) x 10(-11) exp[(-491 +/- 12)/T] and k(CD4) = (8.7 +/- 1.8) x 10(-12) exp[(-650 +/- 61)/T] cm(3) molecule(-1) s(-1), respectively. The reaction of C2H + CH4 exhibits a significant kinetic isotope effect at 300 K of k(CH4)/k(CD4) = 2.5 +/- 0.2. Temperature dependent rate constants for C2H + C2H2 were also remeasured over an increased temperature range from 143 to 359 K and found to show a slight negative temperature dependence, which can be expressed as K-C2H2 = 8.6 x 10(-16) T-1.8 exp[(474 +/- 90)/T] cm(3) molecule(-1) s(-1). C1 UNIV COLORADO,NATL INST STAND & TECHNOL,JOINT INST LAB ASTROPHYS,QUANTUM PHYS DIV,BOULDER,CO 80309. UNIV COLORADO,DEPT CHEM & BIOCHEM,BOULDER,CO 80309. NR 21 TC 55 Z9 55 U1 0 U2 2 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 SN 0022-3654 J9 J PHYS CHEM-US JI J. Phys. Chem. PD MAR 21 PY 1996 VL 100 IS 12 BP 4888 EP 4892 DI 10.1021/jp9532677 PG 5 WC Chemistry, Physical SC Chemistry GA UB162 UT WOS:A1996UB16200032 ER PT J AU Plusquellic, DF Votava, O Nesbitt, DJ AF Plusquellic, DF Votava, O Nesbitt, DJ TI Absolute frequency stabilization of an injection-seeded optical parametric oscillator SO APPLIED OPTICS LA English DT Article DE frequency stabilization; optical parametric oscillator; injection-seeded; stabilized He-Ne; transfer cavity ID BETA-BARIUM BORATE; ND-YAG LASER; 2ND-HARMONIC GENERATION; DYE-LASER; BETA-BAB2O4; PHOTODISSOCIATION; OPERATION; BAB2O4; SYSTEM; CAVITY AB A method is described that provides absolute frequency stabilization and calibration of the signal and idler waves generated by an injection-seeded optical parametric oscillator (OPO). The method makes use of a He-Ne stabilized transfer cavity (TC) to control the frequencies of the cw sources used to seed both the pump laser and OPO cavity. The TC serves as a stable calibration source for the signal and idler waves by providing marker fringes as the seed laser is scanned. Additionally, an acoustic-optic modulator (AOM) is used to shift the OPO seed laser's frequency before locking it onto the TC. The sidebands of the AOM are tunable over more than one free spectral range of the TC, thereby permitting stabilization of the signal and idler waves at any frequency. A +/-25-MHz residual error in the absolute frequency stabilities of the pump, signal, and idler waves is experimentally demonstrated, which is roughly 30% of the 160-MHz near-transform-limited linewidths of the signal and idler pulses. (C) 1996 Optical Society of America C1 NATL INST STAND & TECHNOL,BOULDER,CO 80309. RP Plusquellic, DF (reprint author), UNIV COLORADO,JOINT INST LAB ASTROPHYS,BOULDER,CO 80309, USA. NR 41 TC 18 Z9 18 U1 3 U2 6 PU OPTICAL SOC AMER PI WASHINGTON PA 2010 MASSACHUSETTS AVE NW, WASHINGTON, DC 20036 SN 0003-6935 J9 APPL OPTICS JI Appl. Optics PD MAR 20 PY 1996 VL 35 IS 9 BP 1464 EP 1472 DI 10.1364/AO.35.001464 PG 9 WC Optics SC Optics GA UA966 UT WOS:A1996UA96600011 PM 21085259 ER PT J AU Misra, DN AF Misra, DN TI Adsorption of potassium N-phenylglycinate on hydroxyapatite: Role of solvents and ionic charge SO COLLOIDS AND SURFACES A-PHYSICOCHEMICAL AND ENGINEERING ASPECTS LA English DT Article DE adsorption; hydroxyapatite; ionic charge; potassium N-phenylglycinate; solvent role ID HARD TOOTH TISSUES; INTERFACIAL PROPERTIES; AQUEOUS-SOLUTION; DENTIN; FLUORAPATITE; FLUORIDE AB The adsorption of the potassium salt of N-phenylglycine (KNPG) on synthetic hydroxyapatite from aqueous and ethanol solutions was studied at 22 degrees C. The adsorption isotherm of KNPG from aqueous solutions is Langmuirian in shape, and the analysis showed that one glycinate ion was adsorbed per about two (100) faces of the unit cell of hydroxyapatite. For each glycinate ion adsorbed, 3.5 phosphate ions were released to the aqueous solution while the calcium concentration decreased slightly. The adsorption from ethanol (99.8%) was total and irreversible from dilute solutions up to a threshold concentration, and reversible and Langmuirian thereafter from concentrated solutions, while the amounts of phosphate and calcium ions in solution are negligible. At maximum coverage from ethanol solution, the surface is fully occupied by reversibly adsorbed molecules which are perched on a one-to-one basis on the top of irreversibly adsorbed molecules totally covering the substrate. The amount of irreversibly adsorbed solute is thus about equal to the reversibly adsorbed solute and about twice the maximum amount adsorbed from aqueous solutions. That the adsorption involves electrically neutral molecular units and not electrically charged ions from ethanol is demonstrated by the irreversibly and maximally adsorbed molecules which totally occupy the surface, showing no ionic repulsion between them, and by the absence of ionic exchange of the molecules with the substrate. The study may have a bearing on the role of solvents upon the chemistry of N-phenylglycine analogs and their salts, both of which are used as surface-active polymerization initiators in the bonding of prosthetic resins to teeth. RP Misra, DN (reprint author), NIST,DIV POLYMERS,PAFFENBARGER RES CTR,AMER DENT ASSOC HLTH FDN,GAITHERSBURG,MD 20899, USA. NR 22 TC 2 Z9 2 U1 2 U2 3 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 MAR 20 PY 1996 VL 108 IS 2-3 BP 277 EP 285 DI 10.1016/0927-7757(95)03411-0 PG 9 WC Chemistry, Physical SC Chemistry GA UB008 UT WOS:A1996UB00800014 ER PT J AU Solomon, S Portmann, RW Garcia, RR Thomason, LW Poole, LR McCormick, MP AF Solomon, S Portmann, RW Garcia, RR Thomason, LW Poole, LR McCormick, MP TI The role of aerosol variations in anthropogenic ozone depletion at northern midlatitudes SO JOURNAL OF GEOPHYSICAL RESEARCH-ATMOSPHERES LA English DT Article ID AIRCRAFT SULFUR EMISSIONS; HETEROGENEOUS CHEMISTRY; STRATOSPHERIC OZONE; ANTARCTIC VORTEX; SULFATE AEROSOLS; GLOBAL OZONE; MT-PINATUBO; TRENDS; ERUPTION; WINTER AB Aerosol surface area distributions inferred from satelliteborne 1-mu m extinction measurements are used as input to a two-dimensional model to study the effects of heterogeneous chemistry upon anthropogenic ozone depletion at northern midlatitudes, It is shown that short-term (interannual) and longer-term (decadal) changes in aerosols very likely played a substantial role along with trends in anthropogenic chlorine and bromine in both triggering the ozone losses observed at northern midlatitudes in the early 1980s and increasing the averaged long-term ozone depletions of the past decade or so. The use of observed aerosol distributions enhances the calculated ozone depletion due to halogen chemistry below about 25 km over much of the past decade, including many periods not generally thought to be affected by volcanic activity. Direct observations (especially the relationships of NOX/NOY and ClO/Cl-Y ratios to aerosol content) confirm the key aspects of the model chemistry that is responsible for this behavior and demonstrate chat aerosol changes alone are not a mechanism for ozone losses ill the absence of anthropogenic halogen inputs to the stratosphere. It is also suggested that aerosol-induced ozone changes could be confused with Ii-year solar cycle effects in some statistical analyses, resulting in an overestimate of the trends ascribed to solar activity. While the timing of the observed ozone changes over about the past 15 years is in remarkable agreement with the model predictions that explicitly include observed aerosol changes, their magnitude is about 50% larger than calculated. Possible chemical and dynamical causes of this discrepancy are explored. On the basis of this work, it is shown that the timing and magnitude of future ozone losses at midlatitudes in the northern hemisphere are likely to be strongly dependent upon volcanic aerosol variations as well as on future chlorine and bromine loading. C1 NATL CTR ATMOSPHER RES, BOULDER, CO 80307 USA. NASA, LANGLEY RES CTR, AEROSOL RES BRANCH, HAMPTON, VA 23665 USA. RP Solomon, S (reprint author), NOAA, AERON LAB, R-E-AL8, 325 BROADWAY, BOULDER, CO 80303 USA. RI Portmann, Robert/C-4903-2009 OI Portmann, Robert/0000-0002-0279-6087 NR 72 TC 260 Z9 265 U1 1 U2 18 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 2169-897X J9 J GEOPHYS RES-ATMOS JI J. Geophys. Res.-Atmos. PD MAR 20 PY 1996 VL 101 IS D3 BP 6713 EP 6727 DI 10.1029/95JD03353 PG 15 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA UB986 UT WOS:A1996UB98600002 ER PT J AU Nevison, CD Solomon, S Russell, JM AF Nevison, CD Solomon, S Russell, JM TI Nighttime formation of N2O5 inferred from the halogen occulatation experiment sunset/sunrise NOx ratios SO JOURNAL OF GEOPHYSICAL RESEARCH-ATMOSPHERES LA English DT Article ID HIGH-LATITUDE STRATOSPHERE; NITROGEN; SUNRISE; MIDDLE; MODEL AB The sunset/sunrise NOX ratios measured in 1994 by the Halogen Occultation Experiment (HALOE) onboard the Upper Atmosphere Research Satellite (UARS) peak at up to 2.8 in the tropics around 30 km and decrease to 1 at the stratopause. These ratios are interpreted by using a fully diurnal one-dimensional model, which considers gas phase reactive nitrogen chemistry, and a two-dimensional model, which includes a more complete set of chemical reactions. The diurnal cycle of nighttime N2O5 formation followed by daytime photolysis entirely accounts for the observed ratios above about 35 km. In the lower to middle stratosphere, additional reactions involving ClONO2 and HNO3 also appear to contribute to the observed diurnal variations in NOX. The limitations of a simple function of ozone, temperature, and length of night, which estimates diurnal variations in NOX based on gas phase reactive nitrogen chemistry, are tested through comparison to one-dimensional model results. The function approximates the one-dimensional model sunset/sunrise NOX ratios well in the lower stratosphere but overestimates them by up to 10% in the upper stratosphere above about 35 km, corresponding to a large overestimate of N2O5 formation. The function is extended to estimate sunrise N2O5 in the middle stratosphere. C1 NASA, LANGLEY RES CTR, DIV ATMOSPHER SCI, HAMPTON, VA 23670 USA. RP Nevison, CD (reprint author), NOAA, ENVIRONM RES LAB, R-E-AL8, 325 BROADWAY, BOULDER, CO 80303 USA. NR 22 TC 10 Z9 10 U1 0 U2 0 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 2169-897X J9 J GEOPHYS RES-ATMOS JI J. Geophys. Res.-Atmos. PD MAR 20 PY 1996 VL 101 IS D3 BP 6741 EP 6748 DI 10.1029/96JD00058 PG 8 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA UB986 UT WOS:A1996UB98600004 ER PT J AU OSullivan, D Chen, P AF OSullivan, D Chen, P TI Modeling the quasi biennial oscillation's influence on isentropic tracer transport in the subtropics SO JOURNAL OF GEOPHYSICAL RESEARCH-ATMOSPHERES LA English DT Article ID GENERAL-CIRCULATION MODEL; NORTHERN-HEMISPHERE; STRATOSPHERIC CIRCULATION; WAVE BREAKING; AEROSOL; WINTER; OZONE AB Tracer transport in the lower stratosphere is investigated using an off-line semi-Lagrangian transport model and winds from a mechanistic three dimensional middle atmosphere model, interpolated to the 650 K isentropic surface, over a winter season, By comparing two simulations, the effect of the quasi-biennial oscillation's (QBO's) easterly or westerly wind phases on low-latitude transport is examined, especially regarding the formation of an apparent subtropical transport barrier at the equatorward edge of the surf zone. The tracer field is diffused less than potential vorticity (PV) and shows sharper gradients and finer structures developing over the winter. In both QBO phases the winter extratropical surf zone is bounded by large tracer gradients equatorward of about 15 degrees latitude. The inability of quasi-stationary Rossby waves to propagate into QBO easterlies leads to a much sharper edge forming between the rapidly stirred extratropical surf zone and the relatively unstirred tropics during the easterly QBO phase than occurs during the westerly QBO phase, In the westerly phase some Rossby wave activity can propagate across the equatorial westerlies and break on reaching the summer hemisphere easterly winds, causing mixing there, Simulations using a tracer initially confined to the tropics show that more tropical air is mixed out to the winter extratropics by Rossby wave stirring when the QBO phase is easterly, despite the sharper band of stronger tracer (or PV) gradient which separates the tropics and the winter extratropics in this phase. While air was mixed out of the tropics in both QBO phase simulations, neither QBO phase simulation showed extratropical air being irreversibly mixed into the tropics. These results are related to observations of the tropical reservoir of stratospheric aerosols, especially the dynamics and transport of its winter hemisphere boundary. C1 UNIV COLORADO, NOAA, COOPERAT INST RES ENVIRONM SCI, BOULDER, CO 80309 USA. RP OSullivan, D (reprint author), NW RES ASSOCIATES INC, POB 3027, BELLEVUE, WA 98009 USA. NR 34 TC 21 Z9 21 U1 0 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 MAR 20 PY 1996 VL 101 IS D3 BP 6811 EP 6821 DI 10.1029/96JD00001 PG 11 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA UB986 UT WOS:A1996UB98600010 ER PT J AU Yvon, SA Saltzman, ES Cooper, DJ Bates, TS Thompson, AM AF Yvon, SA Saltzman, ES Cooper, DJ Bates, TS Thompson, AM TI Atmospheric sulfur cycling in the tropical Pacific marine boundary layer (12 degrees S,135 degrees W): A comparison of field data and model results .1. Dimethylsulfide SO JOURNAL OF GEOPHYSICAL RESEARCH-ATMOSPHERES LA English DT Article ID ABSORPTION CROSS-SECTIONS; GAS-EXCHANGE; AIRBORNE MEASUREMENTS; PHOTOCHEMICAL MODEL; AEROSOL IONS; OCEAN; SULFIDE; AIR; OZONE; WATER AB Shipboard measurements of atmospheric and seawater DMS were made at 12 degrees S, 135 degrees W for 6 days during March 1992. The mean seawater DMS concentration during this period was 4.1 +/- 0.45 nM (1 sigma, n = 260) and the mean atmospheric DMS mole fraction was 453 +/- 93 pmol mol(-1) (1 sigma, n = 843). Consistent atmospheric diel cycles were observed, with a nighttime maximum and daytime minimum and an amplitude of approximately 85 pmol mol(-1). Photochemical box model calculations were made to test the sensitivity of atmospheric DMS concentrations to the following parameters: 1) sea-to-air flux, 2) boundary layer height, 3) oxidation rate, and 4) vertical entrainment velocities. The observed relationship between the mean oceanic and atmospheric DMS levels require the use of an air-sea exchange coefficient which is at the upper limit end of the range of commonly used parameterizations. The amplitude of the diel cycle in atmospheric DMS is significantly larger than that predicted by a photochemical model. This suggests that the sea-to-air DMS flux is higher than was previously thought, and the rate of daytime oxidation of DMS is substantially underestimated by current photochemical models of DMS oxidation. C1 NOAA, PACIFIC MARINE ENVIRONM LAB, SEATTLE, WA 98115 USA. UNIV MIAMI, ROSENSTIEL SCH MARINE & ATMOSPHER SCI, MIAMI, FL 33149 USA. NASA, GODDARD SPACE FLIGHT CTR, GREENBELT, MD 20771 USA. RI Yvon-Lewis, Shari/E-4108-2012; Bates, Timothy/L-6080-2016; Thompson, Anne /C-3649-2014 OI Yvon-Lewis, Shari/0000-0003-1378-8434; Thompson, Anne /0000-0002-7829-0920 NR 70 TC 57 Z9 57 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 MAR 20 PY 1996 VL 101 IS D3 BP 6899 EP 6909 DI 10.1029/95JD03356 PG 11 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA UB986 UT WOS:A1996UB98600016 ER PT J AU Yvon, SA Saltzman, ES AF Yvon, SA Saltzman, ES TI Atmospheric sulfur cycling in the tropical Pacific marine boundary layer (12 degrees S,135 degrees W): A comparison of field data and model results .2. Sulfur dioxide SO JOURNAL OF GEOPHYSICAL RESEARCH-ATMOSPHERES LA English DT Article ID SEA-SALT; DIMETHYL SULFIDE; HYDROGEN-SULFIDE; SO2; OXIDATION; OZONE; PHOTOOXIDATION; DISULFIDE; OCEANS; SAGA-3 AB The atmospheric chemistry of sulfur dioxide over the tropical South Pacific Ocean is investigated by using results from field measurements and numerical models. Simultaneous real time measurements of sulfur dioxide and its biogenic precursor dimethylsulfide were made at 12 degrees S, 135 degrees W for a 6-day period from March 3 through March 9, 1992. The mean SO:! and DMS mole fractions were 71 +/- 56 pmol mol(-1) (1 sigma) and 453 +/- 93 pmol mol(-1) (1 sigma) respectively. These concentrations are compared to those predicted by a time-dependent photochemical box model of the marine boundary layer. Model estimates of the yield of SO2 from DMS oxidation range from 27% to 54%. Even with low yields, DMS is the dominant source of SO2 in this region. Estimates of vertical entrainment velocities based on the tropospheric ozone budget suggest that vertical entrainment is a minor source of SO2. The relative rates of various loss mechanisms for SO2 are dry deposition to the sea surface (58%), in-cloud oxidation (9%), OH oxidation (5%), and uptake by sea-salt aerosols (28%). C1 UNIV MIAMI, ROSENSTIEL SCH MARINE & ATMOSPHER SCI, MIAMI, FL 33149 USA. RP Yvon, SA (reprint author), NOAA, CLIMATE MONITORING & DIAGNOST LAB, R-E-CG1, 325 BROADWAY, BOULDER, CO 80303 USA. RI Yvon-Lewis, Shari/E-4108-2012 OI Yvon-Lewis, Shari/0000-0003-1378-8434 NR 42 TC 35 Z9 35 U1 0 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 MAR 20 PY 1996 VL 101 IS D3 BP 6911 EP 6918 DI 10.1029/95JD03355 PG 8 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA UB986 UT WOS:A1996UB98600017 ER PT J AU Covert, DS Kapustin, VN Bates, TS Quinn, PK AF Covert, DS Kapustin, VN Bates, TS Quinn, PK TI Physical properties of marine boundary layer aerosol particles of the mid-Pacific in relation to sources and meteorological transport SO JOURNAL OF GEOPHYSICAL RESEARCH-ATMOSPHERES LA English DT Article ID SIZE DISTRIBUTION; NUCLEI AB Aerosol measurements were made on three cruises in the mid-Pacific along longitude 140 degrees W from 55 degrees N to 70 degrees S for a total of about 90 days in 1992 and 1993. The three data sets document the aerosol concentration and general features of its number-size distribution in the marine boundary layer (MEL) and their variation with latitude and meteorological conditions. Mean concentration varied from 300 cm(-3) in the tropics to 500 cm(-3) in the midlatitudes outside of continental air masses. Infrequent short-term spikes in concentration ranged up to 2000 cm(-3). Two dominant modes were observed, the Aitken and accumulation, with mean diameters of 25 to 60 nm and 150 to 200 nm, respectively. An intermittent ultrafine mode was noted at diameters less than 25 nm. The concentration and dominance of one mode over another depended on the relative strength of the entrainment of ultrafine and Aitken particles from the free troposphere (FT) into the MBL compared to the rate of growth of Aitken mode into accumulation mode particles and removal rate of the accumulation mode. In general, aging times were shorter in the subtropics, longer in the tropics, and variable in the midlatitudes. The rate of new particle formation within the MBL itself was either low and did not contribute significantly to the observed number concentration or, if the rate was high, it occurred infrequently and was not observed in these experiments. C1 NOAA, PACIFIC MARINE ENVIRONM LAB, SEATTLE, WA 98115 USA. UNIV WASHINGTON, JOINT INST STUDY ATMOSPHERE & OCEANS, SEATTLE, WA 98195 USA. RP Covert, DS (reprint author), UNIV WASHINGTON, DEPT ATMOSPHER SCI, SEATTLE, WA 98195 USA. RI Bates, Timothy/L-6080-2016; Quinn, Patricia/R-1493-2016 OI Quinn, Patricia/0000-0003-0337-4895 NR 22 TC 105 Z9 105 U1 4 U2 13 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 2169-897X J9 J GEOPHYS RES-ATMOS JI J. Geophys. Res.-Atmos. PD MAR 20 PY 1996 VL 101 IS D3 BP 6919 EP 6930 DI 10.1029/95JD03068 PG 12 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA UB986 UT WOS:A1996UB98600018 ER PT J AU Quinn, PK Kapustin, VN Bates, TS Covert, DS AF Quinn, PK Kapustin, VN Bates, TS Covert, DS TI Chemical and optical properties of marine boundary layer aerosol particles of the mid-Pacific in relation to sources and meteorological transport SO JOURNAL OF GEOPHYSICAL RESEARCH-ATMOSPHERES LA English DT Article ID SIZE DISTRIBUTION; REFRACTIVE-INDEX; URBAN AEROSOL; SULFUR CYCLE; ATMOSPHERE; SULFATE; DIMETHYLSULFIDE; NUCLEI; MODEL; OCEAN AB Incorporating the direct effect of tropospheric aerosol on climate into global climate models involves coupling the optical properties of the aerosol with its physical and chemical properties. This coupling is strengthened if the optical, physical, and chemical properties of the individual aerosol components are known as well as how these properties depend on the air mass source and synoptic scale meteorology. To relate properties of the aerosol components to air mass sources over a wide range of meteorological conditions, two long latitudinal cruises were conducted in the central Pacific Ocean from 55 degrees N to 70 degrees S. Submicron non-sea-salt (nss) SO4= aerosol averaged about 35 to 40% of the submicron ionic mass as analyzed by ion chromatography and 6% of the total ionic mass, while supermicron nss SO4= aerosol contributed about 1% to the total ionic mass. About 1% of the remaining total ionic mass was composed of methanesulfonate and 90% was sea salt. Ionic mass fractions of nss SO4= aerosol were highest in regions having the longest marine boundary layer residence times or the largest source of marine or continental gas phase precursors. The calculated scattering by nss SO4= aerosol was highest in these same regions due to the dependence of scattering on particle size and the concentration of nss SO4= in the submicron size range. The calculated scattering by submicron sea salt was similar to that of the nss SO4= aerosol, indicating that its contribution to scattering in the marine boundary layer can be significant or even dominant depending on its mass concentration. Mass scattering efficiencies for nss SO4= at 30% RH ranged from 4.3 to 7.5 m(2) g(-1) and for submicron sea salt from 3.5 to 7.7 m(2) g(-1). Mass backscattering efficiencies for nss SO4= ranged from 0.41 to 0.58 m(2) g(-1) and for submicron sea salt from 0.33 to 0.63 m(2) g(-1). These values fall within the same range as others reported previously for the marine atmosphere. C1 UNIV WASHINGTON, DEPT ATMOSPHER SCI, SEATTLE, WA 98195 USA. RP Quinn, PK (reprint author), NOAA, PACIFIC MARINE ENVIRONM LAB, 7600 SAND POINT WAY NE, SEATTLE, WA 98115 USA. RI Bates, Timothy/L-6080-2016; Quinn, Patricia/R-1493-2016 OI Quinn, Patricia/0000-0003-0337-4895 NR 51 TC 77 Z9 77 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 MAR 20 PY 1996 VL 101 IS D3 BP 6931 EP 6951 DI 10.1029/95JD03444 PG 21 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA UB986 UT WOS:A1996UB98600019 ER PT J AU Bates, TS Kelly, KC Johnson, JE Gammon, RH AF Bates, TS Kelly, KC Johnson, JE Gammon, RH TI A reevaluation of the open ocean source of methane to the atmosphere SO JOURNAL OF GEOPHYSICAL RESEARCH-ATMOSPHERES LA English DT Article ID CARBON-MONOXIDE; TROPOSPHERIC METHANE; SOUTH-PACIFIC; NITROUS-OXIDE; SEA; WATER; AIR; SEAWATER; NORTH; ACCUMULATION AB Seawater and atmospheric methane (CH4) mixing ratios were measured on five cruises throughout the Pacific Ocean from 1987 to 1994 to assess the magnitude of the ocean-atmosphere flux. The results showed consistent regional and seasonal variations with surface seawater concentrations ranging from 1.6 to 3.6 nM and saturation ratios ranging from 0.95 to 1.17. The equatorial Pacific Ocean was supersaturated with respect to atmospheric CH4 partial pressures, while areas outside the tropics often were undersaturated during fall and winter. Although atmospheric CH4 mixing ratios over the North Pacific during April increased 3.4% from 1988 to 1993, the saturation ratios remained constant. Based on the concentration fields, the data were divided into two seasons and 10 latitude zones from 75 degrees S to 75 degrees N. Using monthly Comprehensive Ocean-Atmosphere Data Set (COADS) wind and surface seawater temperature data and the Wanninkhof [1992] wind speed/transfer velocity relationship, the calculated zonal average fluxes ranged from -0.1 to 0.4 mu mol m(-2) d(-1). The combined seasonal and zonal fluxes result in a total global ocean-to-atmosphere flux of 25 Gmol yr(-1) (0.4 Tg CH4 yr(-1)), which is an order of magnitude less than previous estimates [Intergovernmental Panel on Climate Change (IPCC), 1994]. The estimated uncertainty in this number is approximately a factor of 2. C1 UNIV WASHINGTON, DEPT CHEM, SEATTLE, WA 98195 USA. UNIV WASHINGTON, JOINT INST STUDY ATMOSPHERE & OCEANS, SEATTLE, WA 98195 USA. UNIV WASHINGTON, SCH OCEANOG, SEATTLE, WA 98195 USA. RP Bates, TS (reprint author), NOAA, PACIFIC MARINE ENVIRONM LAB, 7600 SAND POINT WAY NE, SEATTLE, WA 98115 USA. RI Bates, Timothy/L-6080-2016 NR 53 TC 77 Z9 85 U1 0 U2 13 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 2169-897X J9 J GEOPHYS RES-ATMOS JI J. Geophys. Res.-Atmos. PD MAR 20 PY 1996 VL 101 IS D3 BP 6953 EP 6961 DI 10.1029/95JD03348 PG 9 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA UB986 UT WOS:A1996UB98600020 ER PT J AU Marshall, TC Stolzenburg, M Rust, WD AF Marshall, TC Stolzenburg, M Rust, WD TI Electric field measurements above mesoscale convective systems SO JOURNAL OF GEOPHYSICAL RESEARCH-ATMOSPHERES LA English DT Article ID ACTIVE THUNDERSTORM; CONDUCTIVITY; CALIBRATION; ATMOSPHERE; IONOSPHERE; NETWORK AB We show that electric field discontinuities occur above the stratiform clouds associated with mesoscale convective systems. Above cloud top, 12 discontinuities were observed at altitudes between 10 and 16 km. The field changes of the discontinuities ranged from -1.1 to -4.0 kV m(-1). The data suggest that the electric field discontinuities were caused by coincident, positive, cloud-to-ground lightning flashes. The coincident ground flashes included both single and multiple return stroke flashes, with first-stroke peak currents between 20 and 154 kA, We modeled the electric field change that would occur if lightning discharged a horizontally extensive positive charge layer within the stratiform cloud, In the model, disks with charge densities of 1 and 3 nC m(-3), a thickness of 400 m, and diameters ranging from 20 to 200 km were discharged and produced field changes similar to the observed above-cloud field discontinuities. Our results support the idea that sprites may be initiated by above-cloud field changes caused by positive cloud-to-ground lightning flashes that discharge a horizontally extensive charge region in the stratiform cloud of a mesoscale convective system. During the time between the electric field discontinuities the electric field above the stratiform clouds was -0.5 to -1.0 kV m(-1) this field may be important in the global electrical circuit because the stratiform clouds have large horizontal extents (similar to 10(4) km(2)). C1 NOAA, NATL SEVERE STORMS LAB, NORMAN, OK 73069 USA. UNIV OKLAHOMA, COOPERAT INST MESOSCALE METEOROL, NORMAN, OK USA. RP Marshall, TC (reprint author), UNIV MISSISSIPPI, DEPT PHYS & ASTRON, UNIVERSITY, MS 38677 USA. OI Stolzenburg, Maribeth/0000-0001-8773-8101 NR 34 TC 51 Z9 53 U1 0 U2 2 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 2169-897X J9 J GEOPHYS RES-ATMOS JI J. Geophys. Res.-Atmos. PD MAR 20 PY 1996 VL 101 IS D3 BP 6979 EP 6996 DI 10.1029/95JD03764 PG 18 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA UB986 UT WOS:A1996UB98600023 ER PT J AU Bradley, RS Keimig, FT Diaz, HF AF Bradley, RS Keimig, FT Diaz, HF TI Recent changes in the North American Arctic boundary layer in winter - Reply SO JOURNAL OF GEOPHYSICAL RESEARCH-ATMOSPHERES LA English DT Article C1 NOAA, ENVIRONM RES LAB, BOULDER, CO 80303 USA. RP Bradley, RS (reprint author), UNIV MASSACHUSETTS, DEPT GEOSCI, AMHERST, MA 01003 USA. NR 2 TC 1 Z9 1 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 MAR 20 PY 1996 VL 101 IS D3 BP 7135 EP 7136 DI 10.1029/95JD03722 PG 2 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA UB986 UT WOS:A1996UB98600035 ER PT J AU Coughlan, M Avissar, R AF Coughlan, M Avissar, R TI The global energy and water cycle experiment (GEWEX) continental-scale international project (GCIP): An overview SO JOURNAL OF GEOPHYSICAL RESEARCH-ATMOSPHERES LA English DT Article AB This paper provides a brief historical overview of the Global Energy and Water Cycle Experiment (GEWEX) Continental-Scale International Project (GCIP), the basis for selecting the principal site for this experiment, the scientific objectives, and the strategic planning that has been brought to bear in preparing for the implementation of the project. It also provides a summary of the 25 papers published in this special issue, which collectively represent the launching point for research in the GEWEX's initiatives on continental-scale hydrometeorology. C1 NOAA, OFF GLOBAL PROGRAMS, SILVER SPRING, MD 20910 USA. RP Coughlan, M (reprint author), RUTGERS STATE UNIV, DEPT ENVIRONM SCI, COOK CAMPUS, NEW BRUNSWICK, NJ 08903 USA. NR 6 TC 33 Z9 34 U1 2 U2 8 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 2169-897X J9 J GEOPHYS RES-ATMOS JI J. Geophys. Res.-Atmos. PD MAR 20 PY 1996 VL 101 IS D3 BP 7139 EP 7147 DI 10.1029/96JD00125 PG 9 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA UB986 UT WOS:A1996UB98600037 ER PT J AU Rabin, RM Martin, DW AF Rabin, RM Martin, DW TI Satellite observations of shallow cumulus coverage over the central United States: An exploration of land use impact on cloud cover SO JOURNAL OF GEOPHYSICAL RESEARCH-ATMOSPHERES LA English DT Article ID SOIL-MOISTURE; VEGETATION; PREDICTION; DYNAMICS; SURFACES; SAHEL AB A simple algorithm is presented which identifies cumulus clouds in visible and infrared satellite image pairs. The algorithm is applied to hourly pairs of the Geostationary Operational Environmental Satellite (GOES) to determine the relative frequency of daytime cumulus clouds over the central United States for two consecutive Julys: one drought (1988) and one control (1987). In both Julys, cumulus frequency decreased from southeast to northwest, against the gradient of elevation, but with the gradient of midday average relative humidity. On the scale of uplands and lowlands and even isolated ridges it tended to increase with elevation. During the drought in July, contrasts in vegetative cover were especially large. These contrasts tended to oppose contrasts in surface temperature inferred from satellite radiometers. They also tended to oppose contrasts in the frequency of shallow cumulus. Over central and southern Illinois, a flat to gently undulating, mostly rural plain, during July 1988, shallow cumulus clouds occurred more often over lightly vegetated than heavily vegetated landscapes. These clouds also tended to be relatively abundant near the larger urban centers. During the control July of 1987, fewer cumulus clouds were recorded. C1 UNIV WISCONSIN, CTR SPACE SCI & ENGN, MADISON, WI USA. RP Rabin, RM (reprint author), UNIV WISCONSIN, NOAA, NSSL, 1225 W DAYTON ST, MADISON, WI 53706 USA. NR 30 TC 33 Z9 34 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 MAR 20 PY 1996 VL 101 IS D3 BP 7149 EP 7155 DI 10.1029/95JD02891 PG 7 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA UB986 UT WOS:A1996UB98600038 ER PT J AU Duan, QY Schaake, JC Koren, VI AF Duan, QY Schaake, JC Koren, VI TI FIFE 1987 water budget analysis SO JOURNAL OF GEOPHYSICAL RESEARCH-ATMOSPHERES LA English DT Article ID FIELD EXPERIMENT; SOIL-MOISTURE; SURFACE; GRASSLAND; BALANCE AB The First International Satellite Land Surface Climatology Project (ISLSCP) Field Experiment (FIFE) represents one of the largest data collection campaigns to date in our endeavor to observe the hydrodynamic and thermodynamic processes occurring on the land surface of the Earth. Data for FIFE have been widely used to improve our understanding of land surface processes and to improve the representation of the land surface and boundary layer in atmospheric models. Because FIFE data are being used to test models of land surface processes, it is important to examine how well the FIFE data preserve the water budget. Therefore this study examined the data consistency issue from a hydrologic perspective. More specifically, we investigated whether there is a consistent land surface water balance for the FIFE area over the 1987 experiment period. All components of water balance, i.e., rainfall, evaporation, runoff, and soil moisture, were examined individually as well as collectively. Gridded fields were made of each component. Both the gridded fields and areal averages were analyzed. The processed data were also compared with the data sets processed by other researchers. Inconsistencies in the data were pointed out and the sources were investigated. The results indicate that spatially averaged rainfall, fluxes, and soil moisture storage time series derived from the FIFE data close the water budget reasonably well. It is recommended that these data be used for future development and testing of models. RP Duan, QY (reprint author), NOAA, NWS, OFF HYDROL, WOHX3, 1325 EW HIGHWAY, SILVER SPRING, MD 20910 USA. RI Duan, Qingyun/C-7652-2011 OI Duan, Qingyun/0000-0001-9955-1512 NR 14 TC 12 Z9 12 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 MAR 20 PY 1996 VL 101 IS D3 BP 7197 EP 7207 DI 10.1029/95JD02170 PG 11 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA UB986 UT WOS:A1996UB98600043 ER PT J AU Chen, F Mitchell, K Schaake, J Xue, YK Pan, HL Koren, V Duan, QY Ek, M Betts, A AF Chen, F Mitchell, K Schaake, J Xue, YK Pan, HL Koren, V Duan, QY Ek, M Betts, A TI Modeling of land surface evaporation by four schemes and comparison with FIFE observations SO JOURNAL OF GEOPHYSICAL RESEARCH-ATMOSPHERES LA English DT Article ID GENERAL-CIRCULATION MODELS; SOIL-MOISTURE; SIMPLE PARAMETERIZATION; MESOSCALE CIRCULATIONS; VEGETATION; HYDROLOGY; LAYER; EVAPOTRANSPIRATION; SENSITIVITY; CONDUCTANCE AB We tested four land surface parameterization schemes against long-term (5 months) area-averaged observations over the 15 km x 15 km First International Satellite Land Surface Climatology Project (ISLSCP) Field Experiment (FIFE) area. This approach proved to be very beneficial to understanding the performance and limitations of different land surface models. These four surface models, embodying different complexities of the evaporation/hydrology treatment, included the traditional simple bucket model, the simple water balance (SWB) model, the Oregon State University (OSU) model, and the simplified Simple Biosphere (SSiB) model, The bucket model overestimated the evaporation during wet periods, and this resulted in unrealistically large negative sensible heat fluxes. The SWB model, despite its simple evaporation formulation, simulated well the evaporation during wet periods, but it tended to underestimate the evaporation during dry periods. Overall, the OSU model ably simulated the observed seasonal and diurnal variation in evaporation, soil moisture, sensible heat flux, and surface skin temperature, The more complex SSiB model performed similarly to the OSU model. A range of sensitivity experiments showed that some complexity in the canopy resistance scheme is important in reducing both the overestimation of evaporation during wet periods and underestimation during dry periods. Properly parameterizing not only the effect of soil moisture stress but also other canopy resistance factors, such as the vapor pressure deficit stress, is critical for canopy resistance evaluation, An overly simple canopy resistance that includes only soil moisture stress is unable to simulate observed surface evaporation during dry periods. Given a modestly comprehensive time-dependent canopy resistance treatment, a rather simple surface model such as the OSU model can provide good area-averaged surface heat fluxes for mesoscale atmospheric models. C1 ATMOSPHER RES, PITTSFORD, VT 05763 USA. NOAA, NATL WEATHER SERV, OFF HYDROL, SILVER SPRING, MD 20910 USA. OREGON STATE UNIV, COLL OCEAN & ATMOSPHER SCI, CORVALLIS, OR 97331 USA. CTR OCEAN LAND ATMOSPHERE STUDIES, CALVERTON, MD 20705 USA. RP Chen, F (reprint author), NOAA, NWS,ENVIRONM MODELING CTR,DEV DIV,W-NMC22,WWB, RM 204, 5200 AUTH RD, CAMP SPRINGS, MD 20746 USA. RI Betts, Alan/H-5282-2011; Chen, Fei/B-1747-2009; Duan, Qingyun/C-7652-2011 OI Duan, Qingyun/0000-0001-9955-1512 NR 50 TC 490 Z9 529 U1 9 U2 71 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 MAR 20 PY 1996 VL 101 IS D3 BP 7251 EP 7268 DI 10.1029/95JD02165 PG 18 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA UB986 UT WOS:A1996UB98600046 ER PT J AU Schaake, JC Koren, VI Duan, QY Mitchell, K Chen, F AF Schaake, JC Koren, VI Duan, QY Mitchell, K Chen, F TI Simple water balance model for estimating runoff at different spatial and temporal scales SO JOURNAL OF GEOPHYSICAL RESEARCH-ATMOSPHERES LA English DT Article ID SOIL HYDRAULIC-PROPERTIES; VARIABILITY; INFILTRATION; CATCHMENT; HYDROLOGY; COVER AB A parametric water balance model was developed based on statistical averaging of the main hydrological processes. The model has a two-layer structure with both a physical and statistical basis for the model parameters. It was developed to fill a need for models with a small number of parameters and of intermediate complexity between a one-parameter simple bucket and more complex hydrologically oriented models with many parameters such as the Sacramento model. The focus was to improve the representation of runoff relative to the simple bucket without introducing the full complexity of the Sacramento model. The model was designed to operate over a range of time steps to facilitate coupling to an atmospheric model. The model can be used for catchment scale simulations in hydrological applications and for simple representation of runoff in coupled atmospheric/hydrological models. An important role for the simple water balance (SWB) model is to assist in understanding how much complexity in representing land surface processes is needed and can be supported with available data to estimate model parameters. The model is tested using rainfall, runoff, and surface meteorological data for three catchments from different climate regimes. Model performance is compared to performance of a simple bucket model, the Sacramento model, and the Oregon State University land surface model. Finally, a series of tests were conducted to evaluate the sensitivity of SWB performance when it is operated at time steps different from the time step for which it was calibrated. C1 NOAA, NATL WEATHER SERV, OFF HYDROL, SILVER SPRING, MD 20910 USA. NATL WEATHER SERV, DEV DIV, CAMP SPRINGS, MD 20031 USA. RI Chen, Fei/B-1747-2009; Duan, Qingyun/C-7652-2011 OI Duan, Qingyun/0000-0001-9955-1512 NR 57 TC 187 Z9 195 U1 7 U2 33 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 2169-897X J9 J GEOPHYS RES-ATMOS JI J. Geophys. Res.-Atmos. PD MAR 20 PY 1996 VL 101 IS D3 BP 7461 EP 7475 DI 10.1029/95JD02892 PG 15 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA UB986 UT WOS:A1996UB98600060 ER PT J AU Bucci, E Razynska, A Kwansa, H Gryczynski, Z Collins, JH Fronticelli, C Unger, R Braxenthaler, M Moult, J Ji, XH Gilliland, G AF Bucci, E Razynska, A Kwansa, H Gryczynski, Z Collins, JH Fronticelli, C Unger, R Braxenthaler, M Moult, J Ji, XH Gilliland, G TI Positive and negative cooperativities at subsequent steps of oxygenation regulate the allosteric behavior of multistate sebacylhemoglobin SO BIOCHEMISTRY LA English DT Article ID HUMAN-HEMOGLOBIN; QUATERNARY STRUCTURE; MACROMOLECULAR STRUCTURES; BOVINE HEMOGLOBIN; RESOLUTION; REFINEMENT; MODELS; STATE; CELL AB Cross-linked human hemoglobin (HbA) is obtained by reaction with bis(3,5-dibromosalicyl) sebacate. Peptide maps and crystallographic analyses confirm the presence of the 10 carbon atom long sebacyl residue cross-linking the two beta 82 lysines of the beta-cleft (DecHb). The Adair's constants, obtained from the oxygen binding isotherms, show that at the first step of oxygenation normal hemoglobin and DecHb have a very similar oxygen affinity. In DecHb negative binding cooperativity is present at the second step of oxygenation, which has an affinity 27 times lower than at the first step, Positive cooperativity is present at the third binding step, whose affinity is 380 times that of the second step. The fourth binding step shows a weak negative cooperativity with an affinity one-half that of the third step. Crystals of deoxy-DecHb diffracted to 1.9 Angstrom resolution. The resulting atomic coordinates are very similar to those of Fermi et al. [(1984) J. Mol.Biol. 175, 159-174] and Fronticelli et al. [(1994) J. Biol. Chem. 269, 23965-23969] for deoxy-HbA. The electron density map of deoxy-DecHb indicates the presence of the 10 carbon bridge between the beta 82 lysines. Molecular modeling confirms that insertion of the linker into the T structure requires only slight displacement of the two beta 82 lysines. Instead, insertion of the linker into the R and R2 structures [Shaanan (1983) J. Mol. Biol. 171, 31-59; Silva et al, (1992) J. Biol. Chem. 267, 17248-17256] is hindered by serious sterical restrictions. The linker primarily affects the partially and fully liganded states of hemoglobin The data suggest in DecHb concerted conformational changes at each step of oxygenation. C1 UNIV MARYLAND,MARYLAND BIOTECHNOL INST,CTR MED BIOTECHNOL,BALTIMORE,MD 21201. NIST,ROCKVILLE,MD 20850. UNIV MARYLAND,INST BIOTECHNOL,CTR ADV RES BIOTECHNOL,ROCKVILLE,MD 20850. RP Bucci, E (reprint author), UNIV MARYLAND,SCH MED,DEPT BIOL CHEM,108 N GREENE ST,BALTIMORE,MD 21201, USA. RI Ji, Xinhua/C-9664-2012 OI Ji, Xinhua/0000-0001-6942-1514 FU NHLBI NIH HHS [P01-HL-48517, R01-HL-13164] NR 44 TC 19 Z9 19 U1 0 U2 1 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 SN 0006-2960 J9 BIOCHEMISTRY-US JI Biochemistry PD MAR 19 PY 1996 VL 35 IS 11 BP 3418 EP 3425 DI 10.1021/bi952446b PG 8 WC Biochemistry & Molecular Biology SC Biochemistry & Molecular Biology GA UA989 UT WOS:A1996UA98900009 PM 8639491 ER PT J AU Tanenbaum, DM Laracuente, AL Gallagher, A AF Tanenbaum, DM Laracuente, AL Gallagher, A TI Nanoparticle deposition in hydrogenated amorphous silicon films during rf plasma deposition SO APPLIED PHYSICS LETTERS LA English DT Article ID PARTICLES; KINETICS; SURFACE AB Particles of 2-14 nm diameter, representing 10(-4)-10(-3) of the film volume, are observed by scanning tunneling microscopy (STM) in thin films of hydrogenated amorphous silicon (a-Si:H) grown by rf-plasma-enhanced deposition using optimized conditions. The particles are produced in the discharge and incorporated in the film during growth, in contradiction to expected particle trapping by discharge sheath fields. The interfaces between the nanoparticles and the homogeneous film can produce low-density regions that form electronic defects in a-Si:H films. (C) 1996 American Institute of Physics. C1 NATL INST STAND & TECHNOL,JOINT INST LAB ASTROPHYS,BOULDER,CO 80309. UNIV COLORADO,BOULDER,CO 80309. NR 21 TC 52 Z9 52 U1 4 U2 12 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 MAR 18 PY 1996 VL 68 IS 12 BP 1705 EP 1707 DI 10.1063/1.115912 PG 3 WC Physics, Applied SC Physics GA UA597 UT WOS:A1996UA59700038 ER PT J AU Zilio, SC Marcassa, L Muniz, S Horowicz, R Bagnato, V Napolitano, R Weiner, J Julienne, PS AF Zilio, SC Marcassa, L Muniz, S Horowicz, R Bagnato, V Napolitano, R Weiner, J Julienne, PS TI Polarization dependence of optical suppression in photoassociative ionization collisions in a sodium magneto-optic trap SO PHYSICAL REVIEW LETTERS LA English DT Article AB Three-dimensional quantum scattering calculations predict that the degree of optical shielding of cold collisions saturates with increasing intensity very differently from two-state models and is sensitive to the polarization of the shielding light. We report measurements showing how suppression of Na photoassociative ionization (PAI) rates is sensitive to the intensity and polarization of the shielding laser. At higher intensities, circular polarization suppresses PAI rates an order of magnitude more effectively than linear polarization, in qualitative agreement with our model calculations. C1 UNIV MARYLAND,DEPT CHEM & BIOCHEM,COLLEGE PK,MD 20742. NIST,DIV MOLEC PHYS,GAITHERSBURG,MD 20899. RP Zilio, SC (reprint author), UNIV SAO PAULO,INST FIS & QUIM SAO CARLOS,BR-13560 SAO CARLOS,SP,BRAZIL. RI Weiner, John/C-1065-2008; zilio, sergio/B-4663-2011; Bagnato, Vanderlei/C-3133-2012; Muniz, Sergio/G-6426-2012; Napolitano, Reginaldo/H-1034-2012; Marcassa, Luis/H-3158-2012; Julienne, Paul/E-9378-2012 OI Muniz, Sergio/0000-0002-8753-4659; Marcassa, Luis/0000-0003-4047-8984; Julienne, Paul/0000-0002-5494-1442 NR 20 TC 25 Z9 25 U1 1 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 MAR 18 PY 1996 VL 76 IS 12 BP 2033 EP 2036 DI 10.1103/PhysRevLett.76.2033 PG 4 WC Physics, Multidisciplinary SC Physics GA TZ984 UT WOS:A1996TZ98400012 ER PT J AU West, JB Hayes, MA Siggel, MRF Dehmer, JL Dehmer, PM Parr, AC Hardis, JE AF West, JB Hayes, MA Siggel, MRF Dehmer, JL Dehmer, PM Parr, AC Hardis, JE TI Vibrationally resolved photoelectron angular distributions and branching ratios for the carbon dioxide molecule in the wavelength region 685-795 angstrom SO JOURNAL OF CHEMICAL PHYSICS LA English DT Article ID EMISSION-SPECTRUM; BAND SYSTEM; RESONANCES; CO2; PHOTOIONIZATION; AUTOIONIZATION; EXCITATION; IONIZATION; RADIATION; XENON AB Measurements of 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 behavior 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 stretch. An initial analysis of some of the data taken is presented. (C) 1996 American Institute of Physics. C1 ARGONNE NATL LAB,ARGONNE,IL. NIST,GAITHERSBURG,MD 20899. RP West, JB (reprint author), DARESBURY LAB,WARRINGTON WA4 4AD,CHESHIRE,ENGLAND. NR 31 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 0021-9606 J9 J CHEM PHYS JI J. Chem. Phys. PD MAR 15 PY 1996 VL 104 IS 11 BP 3923 EP 3934 DI 10.1063/1.471249 PG 12 WC Chemistry, Physical; Physics, Atomic, Molecular & Chemical SC Chemistry; Physics GA TY728 UT WOS:A1996TY72800007 ER PT J AU McPhaden, MJ AF McPhaden, MJ TI Monthly period oscillations in the Pacific North Equatorial Countercurrent SO JOURNAL OF GEOPHYSICAL RESEARCH-OCEANS LA English DT Article ID SEA-SURFACE TEMPERATURE; TAHITI SHUTTLE EXPERIMENT; TROPICAL PACIFIC; INSTABILITY WAVES; ATLANTIC-OCEAN; MIXED LAYER; CURRENTS; SATELLITE; DYNAMICS; MODEL AB Monthly period oscillations in temperature and velocity in the vicinity of the North Equatorial Countercurrent along 140 degrees W are examined using moored time series data collected during 1988-1989. These oscillations, which presumably derive their energy from instability of the large-scale shear of the zonal equatorial current system, are found to be energetic across a broad band of periods of about 15-50 days. Along 7 degrees N, wavelike motions at these periods propagate westward with a phase speed of about 30-40 cm s(-1) and a zonal wavelength of 750-1150 km. The oscillations are approximately in geostrophic balance with the thermal field, with the velocity vector rotating anticyclonically around westward propagating high sea level centers. Zonal volume transport variations associated with these waves between 5 degrees and 9 degrees N at 20-180 m depth have a standard deviation of about 4.1 Sv, with peak-to-peak changes in some instances approaching 20 Sv. Maximum temperature variance along 140 degrees W occurs between 5 degrees and 7 degrees N at 100-150 m depth in a region of strong mean vertical and meridional temperature gradient associated with a thermocline sloping upward to the north. At the surface, maximum temperature variability occurs from 2 degrees to 5 degrees N in the vicinity of the strong sea surface temperature front north of the equator. Analysis of the upper ocean temperature balance at 7 degrees N, 140 degrees W reveals that meridional advection is important both in the surface layer and in the thermocline. Vertical advection, estimated using vertical velocity calculated from a simplified linear vorticity balance, is also important in the thermocline where it contributes a variance comparable to that of meridional advection. Zonal advection is likely to be significant in the upper 80 m, below which it is probably of secondary importance compared to meridional and vertical advection. One consequence of advection in the temperature balance is that variance is shifted toward lower frequencies in temperature vis-a-vis velocity spectra. This ''red shift'' may account for the apparent difference between periods for instability waves inferred from near-equatorial meridional velocity spectra, and slightly longer periods reported for oscillations of the sea surface temperature front north of the equator based on satellite imagery. RP McPhaden, MJ (reprint author), NOAA,PACIFIC MARINE ENVIRONM LAB,7600 SAND POINT WAY NE,SEATTLE,WA 98115, USA. RI McPhaden, Michael/D-9799-2016 NR 52 TC 53 Z9 54 U1 0 U2 2 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 SN 0148-0227 J9 J GEOPHYS RES-OCEANS JI J. Geophys. Res.-Oceans PD MAR 15 PY 1996 VL 101 IS C3 BP 6337 EP 6359 DI 10.1029/95JC03620 PG 23 WC Oceanography SC Oceanography GA UA574 UT WOS:A1996UA57400003 ER PT J AU Katsaros, KB Adams, JM Mognard, NM AF Katsaros, KB Adams, JM Mognard, NM TI Evolution of two oceanic extratropical cyclones as observed with the special sensor microwave imager and the Geosat and ERS 1 altimeters SO JOURNAL OF GEOPHYSICAL RESEARCH-OCEANS LA English DT Article ID WIND; VALIDATION; RADAR; SEA AB The evolution of two marine cyclones across the North Atlantic and the North Pacific Oceans is followed with a combination of sequential passive and active microwave data. The special sensor microwave/imager (SSM/I) provides estimates of atmospheric parameters: integrated water vapor, precipitation, and ocean surface wind speed. The Geosat and ERS 1 altimeter data are used to derive sea state parameters along the satellite tracks: the significant wave height and the ocean surface wind speed. The SSM/I integrated water vapor gradients are used to locate and follow the evolution of the atmospheric fronts. In regions of precipitation, often located behind the atmospheric fronts, the SSM/I surface wind speed cannot be derived, while the Geosat and ERS 1 altimeter wind speed yields estimates of wind speed gradients across the fronts. It is shown that the combination of SSM/I and satellite altimeters permits additional observations of surface fronts with higher resolution both in space and time than those given in the National Meteorological Center analyses. C1 NOAA,PACIFIC MARINE ENVIRONM LAB,SEATTLE,WA 98115. CTR NATL ETUD SPATIALES,CTR ETUD SPATIALES BIOSPHERE,F-31055 TOULOUSE,FRANCE. RP Katsaros, KB (reprint author), UNIV WASHINGTON,DEPT ATMOSPHER SCI,SEATTLE,WA 98195, USA. NR 20 TC 1 Z9 1 U1 0 U2 0 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 SN 0148-0227 J9 J GEOPHYS RES-OCEANS JI J. Geophys. Res.-Oceans PD MAR 15 PY 1996 VL 101 IS C3 BP 6627 EP 6639 DI 10.1029/95JC02960 PG 13 WC Oceanography SC Oceanography GA UA574 UT WOS:A1996UA57400023 ER PT J AU Lee, SY Feldstein, S AF Lee, SY Feldstein, S TI Two types of wave breaking in an aquaplanet GCM SO JOURNAL OF THE ATMOSPHERIC SCIENCES LA English DT Article ID LINEAR BAROCLINIC WAVES; PLANETARY-WAVES; NORTHERN HEMISPHERE; LIFE-CYCLES; INSTABILITY; PROPAGATION; FLOW; DOWNSTREAM; DECAY AB The characteristics of two distinct types of wave breaking in an aquaplanet general circulation model (GCM) are described. A systematic analysis of wave breaking is possible because when a baroclinic wave packet is present the wave breaking tends to occur in the vicinity of the packet center. Although the refractive index is strictly valid only for linear, quasigeostrophic flows, in this GCM the refractive index is shown to be useful for categorizing two types of wave breaking. Empirical orthogonal function (EOF) analysis is performed using the refractive index obtained (by averaging over one carrier wavelength) at the center of the wave packet. Composite Eliassen-Palm fluxes and upper-level potential vorticity, corresponding to either phase of the first EOF of the refractive index, are consistent with the two types of wave breaking. It is found that the strength of the meridional shear in the upper troposphere is related to the type of wave breaking. Implications of these results for storm track variability in the atmosphere are also discussed. C1 UNIV COLORADO,NOAA,COOPERAT INST RES ENVIRONM SCI,BOULDER,CO 80309. NR 32 TC 25 Z9 25 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 MAR 15 PY 1996 VL 53 IS 6 BP 842 EP 857 DI 10.1175/1520-0469(1996)053<0842:TTOWBI>2.0.CO;2 PG 16 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA UB134 UT WOS:A1996UB13400003 ER PT J AU Cahn, JW VanVleck, ES AF Cahn, JW VanVleck, ES TI Quadrijunctions do not stop two-dimensional grain growth SO SCRIPTA MATERIALIA LA English DT Article ID PARABOLIC EQUATIONS; SURFACES; CURVES C1 COLORADO SCH MINES,DEPT MATH & COMP SCI,GOLDEN,CO 80401. RP Cahn, JW (reprint author), NIST,MAT SCI & ENGN LAB,GAITHERSBURG,MD 20899, USA. RI Van Vleck, Erik/C-3273-2009 NR 13 TC 5 Z9 6 U1 0 U2 2 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 MAR 15 PY 1996 VL 34 IS 6 BP 909 EP 912 DI 10.1016/1359-6462(95)00585-4 PG 4 WC Nanoscience & Nanotechnology; Materials Science, Multidisciplinary; Metallurgy & Metallurgical Engineering SC Science & Technology - Other Topics; Materials Science; Metallurgy & Metallurgical Engineering GA TW216 UT WOS:A1996TW21600011 ER PT J AU Gunion, RF Lineberger, WC AF Gunion, RF Lineberger, WC TI Ultraviolet photoelectron spectroscopy of the tert-butylvinylidene anion SO JOURNAL OF PHYSICAL CHEMISTRY LA English DT Article ID VINYLIDENE-ACETYLENE ISOMERIZATION; REARRANGEMENT AB The 351 nm photoelectron spectrum of the tert-butylvinylidene anion is reported. The electron affinity of the X (1)A' state of tert-butylvinylidene is 0.645(15) eV, and the excitation energy of the (3)A' State is 1.975(15) eV. The influence of the tert-butyl substituent on the properties of the vinylidene group in the anion, neutral singlet, and neutral triplets is examined by comparing the energetics and vibrational modes apparent in the photoelectron spectrum with those of vinylidene, fluorovinylidene, and vinylvinylidene. The electronic state energetics are found to parallel closely those of unsubstituted vinylidene while the vibrational modes activated by electron detachment from the anion are similar to those of vinylvinylidene; using these findings the term energy of the (3)A'' State is estimated as 2.45(15) eV. The tert-butylvinylidene anion photoelectron spectrum is the first to be analyzed without the aid of explicit high-level ab initio calculations, due to the similarity of vibrational modes to those in the vinylvinylidene spectrum. C1 UNIV COLORADO,NATL INST STAND & TECHNOL,JOINT INST LAB ASTROPHYS,BOULDER,CO 80309. UNIV COLORADO,DEPT CHEM & BIOCHEM,BOULDER,CO 80309. NR 14 TC 9 Z9 9 U1 0 U2 2 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 SN 0022-3654 J9 J PHYS CHEM-US JI J. Phys. Chem. PD MAR 14 PY 1996 VL 100 IS 11 BP 4395 EP 4399 DI 10.1021/jp953113r PG 5 WC Chemistry, Physical SC Chemistry GA UA005 UT WOS:A1996UA00500010 ER PT J AU Lovejoy, ER Hanson, DR AF Lovejoy, ER Hanson, DR TI Kinetics and products of the reaction SO3+NH3+N-2 SO JOURNAL OF PHYSICAL CHEMISTRY LA English DT Article ID GAS-PHASE; ENERGY; ACID AB The kinetics of the gas phase reaction SO3 + NH3 + M were measured in N-2 at 295 K over the pressure range 10-400 Torr with laminar flow reactors coupled to a chemical ionization mass spectrometer. The pressure dependence of the second-order rate coefficient is fit well by the generalized Troe formalism giving k(0) = (3.9 +/- 0.8) x 10(-30) cm(6) molecule(-2) s(-1) and k(infinity) = (4.7 +/- 1.3) x 10(-11) cm(3) molecule(-1) s(-1). The association product of the SO3 + NH3 reaction and secondary acid cluster products were detected by chemical ionization mass spectrometry. Models of the temporal behavior of SO3, sulfamic acid, and sulfamic acid dimer show that sulfamic acid dimerizes at near the hard sphere gas kinetic limit (k > 5 x 10(-11) cm(3) molecule(-1) s(-1), 20 Torr N-2, 295 K) and the dimer is relatively stable with respect to decomposition to monomers (Delta G degrees(298) less than or equal to -9 kcal mol(-1)). C1 UNIV COLORADO,COOPERAT INST RES ENVIRONM SCI,BOULDER,CO 80309. RP Lovejoy, ER (reprint author), NOAA,AERON LAB,325 BROADWAY,BOULDER,CO 80303, USA. NR 31 TC 23 Z9 24 U1 1 U2 14 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 SN 0022-3654 J9 J PHYS CHEM-US JI J. Phys. Chem. PD MAR 14 PY 1996 VL 100 IS 11 BP 4459 EP 4465 DI 10.1021/jp952404x PG 7 WC Chemistry, Physical SC Chemistry GA UA005 UT WOS:A1996UA00500020 ER PT J AU Crawford, TM Rogers, CT Silva, TJ Kim, YK AF Crawford, TM Rogers, CT Silva, TJ Kim, YK TI Observation of the transverse second-harmonic magneto-optic Kerr effect from Ni81Fe19 thin film structures SO APPLIED PHYSICS LETTERS LA English DT Article ID 2ND-HARMONIC GENERATION; INTERFACE MAGNETISM AB We report second-harmonic magneto-optic Ken measurements on air-exposed, polycrystalline Ni81Fe19 thin films, ranging in thickness from 1 nm to 2 mu m, on Al2O3 coated Si (001). For samples thicker than 20 nm, in the transverse Ken geometry, we observe a factor of 4 change in second-harmonic intensity upon magnetization reversal. For thin samples, we observe interference between second-harmonic fields from the various interfaces and deterioration of ferromagnetism in the 1 and 2 nm films. Modeling suggests that the Ni81Fe19/Al2O3 interface has a larger second-order susceptibility than the air/Ni81Fe19 surface. (C) 1996 American Institute of Physics. C1 NATL INST STAND & TECHNOL,BOULDER,CO 80303. QUANTUM PERIPHERALS COLORADO INC,LOUISVILLE,CO 80028. RP Crawford, TM (reprint author), UNIV COLORADO,DEPT PHYS,CONDENSED MATTER LAB,BOULDER,CO 80309, USA. RI Silva, Thomas/C-7605-2013 OI Silva, Thomas/0000-0001-8164-9642 NR 15 TC 24 Z9 24 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 MAR 11 PY 1996 VL 68 IS 11 BP 1573 EP 1575 DI 10.1063/1.115703 PG 3 WC Physics, Applied SC Physics GA TZ291 UT WOS:A1996TZ29100045 ER PT J AU Thudium, RN Han, CC AF Thudium, RN Han, CC TI Microstructure effect on the phase behavior of blends of deuterated polybutadiene and protonated polyisoprene SO MACROMOLECULES LA English DT Article ID ANGLE NEUTRON-SCATTERING; CHARACTERISTIC RATIOS; POLYVINYL METHYL-ETHER); LIGHT-SCATTERING; MISCIBILITY; TEMPERATURE; POLYSTYRENE; POLYMERS; DIAGRAMS; MODEL AB Small-angle neutron scattering (SANS) was used to measure the miscibility of blends of protonated polyisoprene (HPI) with 3,4 microstructure in the range of 7-44%, and of deuterated polybutadiene (DPB) with 1,2 microstructure in the range of 9-70%. These data suggest that, for deuterated polybutadiene/protonated polyisoprene blends, overall miscibility is controlled by the 3,4 content of the polyisoprene. This isomeric group is strongly immiscible with the 1,4 butadiene group and the immiscibility decreases with temperature, while the 3,4 group is weakly miscible with the 1,4 isoprene group and miscibility increases with temperature. Conversely, the 3,4 group is strongly miscible with the 1,2 butadiene group and miscibility decreases with increasing temperature. The differing trends of the interaction parameter with temperature suggest that shifts in the LCST phase diagram can be controlled by judicious changes in microstructure. These theoretical predications were confirmed with experimental small-angle light scattering (SALS) results on all protonated blends. The statistical segment length, b, appears to be independent of temperature, but is dependent on total vinyl level. For the blends used in this study, b has a minimum value at approximately 30-35% total vinyl isomeric groups. C1 NATL INST STAND & TECHNOL,DIV POLYMERS,GAITHERSBURG,MD 20899. RP Thudium, RN (reprint author), GOODYEAR TIRE & RUBBER CO,CORP RES,AKRON,OH 44305, USA. NR 23 TC 14 Z9 14 U1 0 U2 5 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 SN 0024-9297 J9 MACROMOLECULES JI Macromolecules PD MAR 11 PY 1996 VL 29 IS 6 BP 2143 EP 2149 DI 10.1021/ma9512465 PG 7 WC Polymer Science SC Polymer Science GA UA294 UT WOS:A1996UA29400041 ER PT J AU Factor, BJ Mopsik, FI Han, CC AF Factor, BJ Mopsik, FI Han, CC TI Dielectric behavior of a polycarbonate/polyester mixture upon transesterification SO MACROMOLECULES LA English DT Article ID BINARY POLYMER BLENDS; COMPATIBILITY RP NATL INST STAND & TECHNOL, MAT SCI & ENGN LAB, POLYMERE DIV, GAITHERSBURG, MD 20899 USA. NR 21 TC 7 Z9 7 U1 0 U2 0 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 0024-9297 EI 1520-5835 J9 MACROMOLECULES JI Macromolecules PD MAR 11 PY 1996 VL 29 IS 6 BP 2318 EP 2320 DI 10.1021/ma950635w PG 3 WC Polymer Science SC Polymer Science GA UA294 UT WOS:A1996UA29400064 ER PT J AU Meekhof, DM Monroe, C King, BE Itano, WM Wineland, DJ AF Meekhof, DM Monroe, C King, BE Itano, WM Wineland, DJ TI Generation of nonclassical motional states of a trapped atom SO PHYSICAL REVIEW LETTERS LA English DT Article ID SQUEEZED STATES; QUANTIZED TRAP; QUANTUM; MODEL; ION AB We report the creation of thermal, Fock, coherent, and squeezed states of motion of a harmonically bound Be-9(+) ion. The last three states are coherently prepared from an ion which has been initially laser cooled to the zero point of motion. The ion is trapped in the regime where the coupling between its motional and internal states, due to applied (classical) radiation, can be described by a Jaynes-Cummings-type interaction. With this coupling, the evolution of the internal atomic state provides a signature of the number state distribution of the motion. RP NATL INST STAND & TECHNOL, DIV TIME & FREQUENCY, BOULDER, CO 80303 USA. RI Monroe, Christopher/G-8105-2011 NR 35 TC 828 Z9 839 U1 6 U2 41 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 MAR 11 PY 1996 VL 76 IS 11 BP 1796 EP 1799 DI 10.1103/PhysRevLett.76.1796 PG 4 WC Physics, Multidisciplinary SC Physics GA TZ282 UT WOS:A1996TZ28200009 ER PT J AU Ellenberg, WJ Karnaky, KJ Scott, GI AF Ellenberg, WJ Karnaky, KJ Scott, GI TI Environmentally-challenged fish: Enhanced expression of the multidrug transporter protein (Pgp) SO FASEB JOURNAL LA English DT Meeting Abstract C1 MED UNIV S CAROLINA,DEPT ANAT & CELL BIOL,CHARLESTON,SC 29425. NOAA,NMFS,SEFS,CHARLESTON,SC 29412. NR 0 TC 0 Z9 0 U1 0 U2 0 PU FEDERATION AMER SOC EXP BIOL PI BETHESDA PA 9650 ROCKVILLE PIKE, BETHESDA, MD 20814-3998 SN 0892-6638 J9 FASEB J JI Faseb J. PD MAR 8 PY 1996 VL 10 IS 3 BP 475 EP 475 PG 1 WC Biochemistry & Molecular Biology; Biology; Cell Biology SC Biochemistry & Molecular Biology; Life Sciences & Biomedicine - Other Topics; Cell Biology GA TZ284 UT WOS:A1996TZ28400477 ER PT J AU Zhao, ZQ Chapman, WB Nesbitt, DJ AF Zhao, ZQ Chapman, WB Nesbitt, DJ TI State-resolved differential scattering in open-shell collisions: Cl(P-2(3/2))+HCl from high-resolution infrared-laser Dopplerimetry SO JOURNAL OF CHEMICAL PHYSICS LA English DT Article ID ROTATIONALLY INELASTIC-SCATTERING; CROSS-SECTIONS; TRANSITION-STATE; ENERGY-DISTRIBUTIONS; CHEMICAL-REACTIONS; CHLORINE ATOMS; QUANTUM; DYNAMICS; AR; PHOTODISSOCIATION AB Time- and frequency-resolved IR-laser absorption methods are used to probe state-resolved collisional energy transfer in open-shell collisions of Cl(P-2(3/2)) radicals with HCl(J) in the near single-collision regime. Translationally ''hot'' Cl(P-2(3/2)) radicals are formed by excimer laser photolysis of Cl-2, which then collide with a room-temperature distribution of HCl peaked at J congruent to 3. Final-state distributions of the HCl are monitored via transient absorption detection of a cw IR probe laser by the collisionally populated states (J = 4, 5, 6,...,12). In previous work [J. Chem. Phys. 102, 7046 (1995)], these transient signals are used to extract absolute integral collisional cross sections for state-resolved rotational energy transfer into final J states. In the present study, high-resolution IR Dopplerimetry with the single-mode probe laser is used to measure translational distributions of the collisionally populated HCl(J) as a function of final J state. Analysis of these translational distributions leads to state-resolved differential scattering cross sections for rotational energy transfer, which exhibit a strong propensity for forward scattering into all levels observed (J less than or equal to 12). These results are compared with quasiclassical trajectory calculations (QCT) on a recently modified potential energy surface of Schatz and Gordon. The theoretical analysis is in good agreement with experiment, with the angular distribution dominated by forward scattering for most of the final HCl rotational states. However, for the very highest J states collisionally populated, the QCT calculations predict a shift from predominantly forward to more isotropic scattering that is not evident in the experimental results. (C) 1996 American Institute of Physics. C1 NATL INST STAND & TECHNOL,BOULDER,CO 80309. UNIV COLORADO,DEPT CHEM,BOULDER,CO 80309. UNIV COLORADO,DEPT CHEM & BIOCHEM,BOULDER,CO 80309. RP Zhao, ZQ (reprint author), UNIV COLORADO,JOINT INST LAB ASTROPHYS,BOULDER,CO 80309, USA. NR 51 TC 5 Z9 5 U1 0 U2 0 PU AMER INST PHYSICS PI WOODBURY PA CIRCULATION FULFILLMENT DIV, 500 SUNNYSIDE BLVD, WOODBURY, NY 11797-2999 SN 0021-9606 J9 J CHEM PHYS JI J. Chem. Phys. PD MAR 8 PY 1996 VL 104 IS 10 BP 3555 EP 3566 DI 10.1063/1.471060 PG 12 WC Chemistry, Physical; Physics, Atomic, Molecular & Chemical SC Chemistry; Physics GA TX780 UT WOS:A1996TX78000019 ER PT J AU Wheeler, AA McFadden, GB Boettinger, WJ AF Wheeler, AA McFadden, GB Boettinger, WJ TI Phase-field model for solidification of a eutectic alloy SO PROCEEDINGS OF THE ROYAL SOCIETY A-MATHEMATICAL PHYSICAL AND ENGINEERING SCIENCES LA English DT Article ID BOUNDARY MOTION; CRYSTAL-GROWTH; EQUILIBRIUM; TRANSITIONS; KINETICS; FILMS AB In this paper we discuss two phase-field models for solidification of a eutectic alloy, a situation in which a liquid may transform into two distinct solid phases. The first is based on a regular solution model for the solid with a chemical miscibility gap. This model suffers from the deficiency that, in the sharp interface limit, it approximates a free-boundary problem in which the surface energy of the solid-solid interface is zero and consequently mechanical equilibrium at a trijunction requires that the solid-solid interface has zero dihedral angle (locally planar). We propose a second model which uses two order parameters to distinguish the liquid phase and the two solid phases. We provide a thermodynamically consistent derivation of this phase-field model which ensures that the local entropy production is positive. We conduct a sharp interface asymptotic analysis of the liquid-solid phase transition and show it is governed by a free-boundary problem in which both surface energy and interface kinetics are present. Finally, we consider a sharp interface asymptotic analysis of a stationary trijunction between the two solid phases and the liquid phase, from which we recover the condition that the interfacial surface tensions are in mechanical equilibrium (Young's equation). This sharp interface analysis compares favourably with numerical solutions of the phase-field model appropriate to a trijunction. C1 NATL INST STAND & TECHNOL, GAITHERSBURG, MD 20899 USA. RI McFadden, Geoffrey/A-7920-2008 OI McFadden, Geoffrey/0000-0001-6723-2103 NR 39 TC 116 Z9 117 U1 7 U2 27 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 MAR 8 PY 1996 VL 452 IS 1946 BP 495 EP 525 DI 10.1098/rspa.1996.0026 PG 31 WC Multidisciplinary Sciences SC Science & Technology - Other Topics GA UM232 UT WOS:A1996UM23200005 ER PT J AU Baird, RC AF Baird, RC TI Sea grant fellows SO SCIENCE LA English DT Letter RP Baird, RC (reprint author), NOAA,NATL SEA GRANT COLL PROGRAM,US DEPT COMMERCE,SILVER SPRING,MD 20910, USA. NR 1 TC 0 Z9 0 U1 0 U2 0 PU AMER ASSOC ADVANCEMENT SCIENCE PI WASHINGTON PA 1200 NEW YORK AVE, NW, WASHINGTON, DC 20005 SN 0036-8075 J9 SCIENCE JI Science PD MAR 8 PY 1996 VL 271 IS 5254 BP 1348 EP 1348 PG 1 WC Multidisciplinary Sciences SC Science & Technology - Other Topics GA TY961 UT WOS:A1996TY96100008 ER PT J AU Tsang, W Bedanov, V Zachariah, MR AF Tsang, W Bedanov, V Zachariah, MR TI Master equation analysis of thermal activation reactions: Energy-transfer constraints on falloff behavior in the decomposition of reactive intermediates with low thresholds SO JOURNAL OF PHYSICAL CHEMISTRY LA English DT Article ID TEMPERATURE AB This paper deals with the high-temperature decomposition of reactive intermediates with low reaction thresholds. If these intermediates are created in situ, for example, through radical chain processes, their initial molecular distribution functions may be characteristic of the bath temperature and, under certain circumstances, peak at energies above the reaction threshold, Such an ordering of reaction thresholds and distribution functions has some similarities to that found during chemical activation. This leads to consequences that are essenially the inverse (larger rate constants than those deduced from steady-state distributions) of the situation for stable compounds under shock-heated conditions and hence reduces falloff effects. To study this behavior, rate constants for the unimolecular decomposition of allyl, ethyl, n-propyl, and n-hexyl radicals have been determined on the basis of the solution of the time-dependent master equation with specific rate constants from RRKM calculations. The time required for the molecules to attain steady-state distribution functions has been determined as a function of the energy-transfer parameter (the step size down) molecular size (heat capacity), high-pressure rate parameters, temperature, and pressure. At 101 kPa (1 atm) pressure, unimolecular rate constants near 10(7) s(-1) represent a lower boundary, above which steady-state assumptions become increasingly questionable. The effects on rate expressions and branching ratios for decomposition reactions during the pre-steady-state period are described. C1 RUSSIAN ACAD SCI,INST THEORET & APPL MECH,NOVOSIBIRSK 630090,RUSSIA. RP Tsang, W (reprint author), NATL INST STAND & TECHNOL,CHEM SCI & TECHNOL LAB,GAITHERSBURG,MD 20899, USA. NR 20 TC 54 Z9 54 U1 1 U2 8 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 SN 0022-3654 J9 J PHYS CHEM-US JI J. Phys. Chem. PD MAR 7 PY 1996 VL 100 IS 10 BP 4011 EP 4018 DI 10.1021/jp9524901 PG 8 WC Chemistry, Physical SC Chemistry GA TY919 UT WOS:A1996TY91900020 ER PT J AU Guldi, DM Neta, P Vogel, E AF Guldi, DM Neta, P Vogel, E TI Radiolytic reduction of tetrapropylporphycene and its iron, cobalt, nickel, copper, and tin complexes SO JOURNAL OF PHYSICAL CHEMISTRY LA English DT Article ID ONE-ELECTRON REDUCTION; PI-RADICAL ANIONS; 2-ELECTRON REDUCTION; PORPHIN ISOMER; PORPHYRINS; PORPHYCENES; PYRIDYLPORPHYRINS; METALLOPORPHYRINS; KINETICS; SITE AB One-electron and multielectron reductions of 2,7,12,17-tetrapropylporphycene (H(2)TPrPc) and its Fe, Co, Ni, Cu, and Sn complexes in 2-PrOH solutions have been studied by radiolytic techniques. Formation and decay of intermediates formed upon one-electron reduction have been followed by kinetic spectrophotometric pulse radiolysis, and the absorption spectra of stable reduction products have been recorded following gamma-radiolysis. H(2)TPrPc; and Sn(IV)TPrPc are reduced to the cc-radical anions and then to the dianions, which are stable in alkaline 2-PrOH. In neutral or acidic solutions, the pi-radical anions undergo proton-enhanced disproportionation and the dianions undergo protonation. With the transition metal complexes, redox reactions of Fe-III/Fe-II and Co-III/Co-II have been observed. The porphycenes of Fe-II, Co-II, Ni-II, and Cu-II are reduced in most cases to form the pi-radical anions, M(II)Pc(.-). The exception is the case of the Co(II)Pc, which forms Co(II)Pc(.-) in alkaline 2-PrOH but yields a short-lived Co(I)Pc in neutral 2-PrOH, Cu(II)Pc(.-) has some Cu-I character, resulting in rapid demetallation in acidic solutions. The radical anions M(II)Pc(.-) also undergo proton-enhanced disproportionation to yield M(II)PcH(2). C1 NATL INST STAND & TECHNOL,THERMODYNAM DIV,GAITHERSBURG,MD 20899. UNIV COLOGNE,INST ORGAN CHEM,D-50939 COLOGNE,GERMANY. RP Guldi, DM (reprint author), UNIV NOTRE DAME,RADIAT LAB,NOTRE DAME,IN 46556, USA. RI Guldi, Dirk/G-1422-2015 NR 32 TC 19 Z9 19 U1 2 U2 5 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 SN 0022-3654 J9 J PHYS CHEM-US JI J. Phys. Chem. PD MAR 7 PY 1996 VL 100 IS 10 BP 4097 EP 4103 DI 10.1021/jp953009+ PG 7 WC Chemistry, Physical SC Chemistry GA TY919 UT WOS:A1996TY91900031 ER PT J AU Weaver, GC Leone, SR AF Weaver, GC Leone, SR TI Fragmentation and recombination of molecules during laser vaporization of cryogenic films SO JOURNAL OF PHYSICAL CHEMISTRY LA English DT Article ID ELECTRON-IMPACT-IONIZATION; CROSS-SECTION MEASUREMENTS; INDUCED PHOTODISSOCIATION; ABLATION; DEPOSITION; ATOMS; DESORPTION; YBA2CU3OX; CHLORINE; SI(100) AB Laser vaporization of cryogenically condensed films of IC1 and Cl-2 is studied by investigating the beams of neutral atoms and molecules formed with high translational kinetic energies. The fragments resulting from the vaporization process of these molecules are examined and compared to the fragmentation patterns of molecules studied previously, XeF2 and NO. It is found that IC1 shows a large amount of fragmentation and recombination during vaporization, which forms Cl-2 and I-2. This is also true for XeF2 and may be true for Cb but does not occur for NO. The degree of recombination is affected by the thickness of the cryogenic film being ablated and depends on the bond energy of the molecule with respect to the photon energy. C1 NATL INST STAND & TECHNOL,JILA,BOULDER,CO 80309. UNIV COLORADO,DEPT CHEM & BIOCHEM,BOULDER,CO 80309. NR 45 TC 10 Z9 10 U1 0 U2 0 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 SN 0022-3654 J9 J PHYS CHEM-US JI J. Phys. Chem. PD MAR 7 PY 1996 VL 100 IS 10 BP 4188 EP 4192 DI 10.1021/jp952717s PG 5 WC Chemistry, Physical SC Chemistry GA TY919 UT WOS:A1996TY91900044 ER PT J AU Hastie, GP Johnstone, J Roberts, KJ Fischer, D AF Hastie, GP Johnstone, J Roberts, KJ Fischer, D TI Examination of the structure and melting behaviour of thin film n-alkanes using ultra-soft polarised near-edge X-ray absorption spectroscopy SO JOURNAL OF THE CHEMICAL SOCIETY-FARADAY TRANSACTIONS LA English DT Article ID LANGMUIR-BLODGETT MONOLAYERS; INDUCED PHASE-TRANSITION; LIQUID NORMAL-ALKANES; SURFACE CRYSTALLIZATION; ORIENTATION; POLYETHYLENE; DYNAMICS; SI(111); FLUIDS; CHAINS AB The use of ultra-soft near-edge X-ray absorption tine structure (NEXAFS) spectroscopy as a tool for determining the molecular orientations, and changes in the orientations and conformations, of thin organic films is presented. Polarisation-dependent NEXAFS measurements made at the carbon K-edge reveal that vapour-grown n-alkanes, deposited onto Si(111), exhibit structures with a high degree of long-range order. The molecular tilt angles, with respect to the substrate surface, for n-alkanes CnH2n+2 in the carbon chain-length range n = 22-60 are found to be consistent with their bulk crystallographic structures. Temperature dependent measurements carried out using simultaneous electron yield and fluorescence yield techniques reveal evidence of surface freezing in the longer even n-alkanes (n greater than or equal to 46). Such a process is not evident in the shorter alkanes. The potential causes of this chain-length dependence are discussed. C1 HERIOT WATT UNIV,DEPT MECH & CHEM ENGN,EDINBURGH EH14 4AS,MIDLOTHIAN,SCOTLAND. UNIV STRATHCLYDE,DEPT PURE & APPL CHEM,GLASGOW G1 1XL,LANARK,SCOTLAND. NATL INST STAND & TECHNOL,GAITHERSBURG,MD 20899. SERC,DARESBURY LAB,CLRC,WARRINGTON WA4 4AD,CHESHIRE,ENGLAND. NR 38 TC 13 Z9 13 U1 2 U2 13 PU ROYAL SOC CHEMISTRY PI CAMBRIDGE PA THOMAS GRAHAM HOUSE, SCIENCE PARK MILTON ROAD, CAMBRIDGE, CAMBS, ENGLAND CB4 4WF SN 0956-5000 J9 J CHEM SOC FARADAY T JI J. Chem. Soc.-Faraday Trans. PD MAR 7 PY 1996 VL 92 IS 5 BP 783 EP 789 DI 10.1039/ft9969200783 PG 7 WC Chemistry, Physical; Physics, Atomic, Molecular & Chemical SC Chemistry; Physics GA UA865 UT WOS:A1996UA86500013 ER PT J AU Hughen, KA Overpeck, JT Peterson, LC Trumbore, S AF Hughen, KA Overpeck, JT Peterson, LC Trumbore, S TI Rapid climate changes in the tropical Atlantic region during the last deglaciation SO NATURE LA English DT Article ID GREENLAND ICE; OCEAN; CIRCULATION; RECORDS; SEDIMENTS; EVENT; CORE AB The climate system is capable of changing abruptly from one stable mode to another(1-3). Rapid climate oscillations--in particular the Younger Dryas cold period during the last deglaciation--have long been recognized from records throughout the North Atlantic region(4-14), and the distribution of these records at mostly high latitudes suggests that the changes were caused by rapid reorganizations of the North Atlantic thermohaline circulation(6,8,10,15). But events far from the North Atlantic region that are synchronous with the Younger Dryas(16-19) raise the possibility that a more global forcing mechanism was responsible(20). Here we present high-resolution records of laminated sediments of the last deglaciation from the Cariaco basin (tropical Atlantic Ocean) which show many abrupt sub-decade to century-scale oscillations in surface-ocean biological productivity that are synchronous with climate changes at high latitudes. We attribute these productivity variations to changes in or duration of upwelling rate (and hence nutrient supply) caused by changes in trade-wind strength, which is in turn influenced by the thermohaline circulation through its effect on sea surface tempersture(6,21). Abrupt climate changes in the tropical Atlantic during the last deglaciation are thus consistent with a North Atlantic circulation forcing mechanism. C1 UNIV COLORADO,DEPT GEOL SCI,BOULDER,CO 80309. UNIV MIAMI,ROSENSTIEL SCH MARINE & ATMOSPHER SCI,MIAMI,FL 33149. NOAA,PALOCLIMATOL PROGRAM,NGDC,BOULDER,CO 80303. UNIV CALIF IRVINE,DEPT EARTH SYST SCI,IRVINE,CA 92717. RP Hughen, KA (reprint author), UNIV COLORADO,INSTAAR,BOULDER,CO 80309, USA. RI Trumbore, Susan/B-1948-2013 NR 34 TC 354 Z9 373 U1 7 U2 64 PU MACMILLAN MAGAZINES LTD PI LONDON PA 4 LITTLE ESSEX STREET, LONDON, ENGLAND WC2R 3LF SN 0028-0836 J9 NATURE JI Nature PD MAR 7 PY 1996 VL 380 IS 6569 BP 51 EP 54 DI 10.1038/380051a0 PG 4 WC Multidisciplinary Sciences SC Science & Technology - Other Topics GA TY877 UT WOS:A1996TY87700051 ER PT J AU Koenig, BW Kruger, S Orts, WJ Majkrzak, CF Berk, NF Silverton, JV Gawrisch, K AF Koenig, BW Kruger, S Orts, WJ Majkrzak, CF Berk, NF Silverton, JV Gawrisch, K TI Neutron reflectivity and atomic force microscopy studies of a lipid bilayer in water adsorbed to the surface of a silicon single crystal SO LANGMUIR LA English DT Article ID SUPPORTED PHOSPHOLIPID-BILAYERS; GLYCOL MONODODECYL ETHER; SPECULAR REFLECTION; PHOSPHATIDYLCHOLINE VESICLES; AQUEOUS-SOLUTION; GEL PHASE; FT-IR; X-RAY; INTERFACE; LAYER AB Specular reflection of neutrons has been used to characterize the structure of single lipid bilayers adsorbed to a planar silicon surface from aqueous solution. We used a novel experimental setup which significantly decreased the incoherent background scattering and allowed us to measure neutron reflectivities as low as 5 x 10(-7). Thicknesses and neutron scattering length densities were determined by a fitting procedure using (i) randomly generated smooth functions represented by parametric B-splines and (ii) stepped functions based on the theoretical lipid composition. The size of lipid domains at the surface and the degree of surface coverage were determined by atomic force microscopy. Chain-protonated and -deuterated dipalmitoylphosphatidylcholine (DPPC) bilayers were investigated in (H2O)-H-2 and a mixture of (H2O)-H-2 and H2O which matches the scattering density of silicon. Also, one measurement on a distearoylphosphatidylcholine bilayer which has longer acyl chains was performed for comparison. The lipid adsorbs to the silicon surface as a continuous layer interrupted by irregularly shaped uncovered areas which are 100-500 Angstrom in size. The surface coverage was estimated to be 70 +/- 20%. The reflectivity measurements on DPPC at 60 degrees C show a silicon oxide layer with a thickness of the order of 4 Angstrom, a rough silicon oxide/water layer between silicon oxide and lipid with a thickness between 2 and 8 Angstrom, and a single lipid bilayer. Fitting resolved a central membrane layer with a thickness of 28 +/- 2 Angstrom which represents the lipid hydrocarbon chains. This layer is sandwiched between interface membrane layers of lipid head groups and water which are 11.5 +/- 1 Angstrom in thickness. The angstrom-scale thickness changes of the central membrane layer as a function of the phase state of the lipid and of the length of the hydrocarbon chains are easily detected. C1 NIAAA,NIH,LAB MEMBRANE BIOCHEM & BIOPHYS,ROCKVILLE,MD 20852. NHLBI,NIH,BIOPHYS CHEM LAB,BETHESDA,MD 20892. NIST,MAT SCI & ENGN LAB,GAITHERSBURG,MD 20899. RI Koenig, Bernd/B-4315-2008 OI Koenig, Bernd/0000-0002-5300-6276 NR 39 TC 204 Z9 206 U1 2 U2 40 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 SN 0743-7463 J9 LANGMUIR JI Langmuir PD MAR 6 PY 1996 VL 12 IS 5 BP 1343 EP 1350 DI 10.1021/la950580r PG 8 WC Chemistry, Multidisciplinary; Chemistry, Physical; Materials Science, Multidisciplinary SC Chemistry; Materials Science GA TZ050 UT WOS:A1996TZ05000037 ER PT J AU Carlisle, JA Shirley, EL Hudson, EA Terminello, LJ Callcott, TA Jia, JJ Ederer, DL Perera, RCC Himpsel, FJ AF Carlisle, JA Shirley, EL Hudson, EA Terminello, LJ Callcott, TA Jia, JJ Ederer, DL Perera, RCC Himpsel, FJ TI Core Hole effects in resonant inelastic x-ray scattering of graphite - Reply SO PHYSICAL REVIEW LETTERS LA English DT Article C1 NATL INST STAND & TECHNOL,GAITHERSBURG,MD 20899. UNIV TENNESSEE,KNOXVILLE,TN 37966. TULANE UNIV,NEW ORLEANS,LA 70118. LAWRENCE BERKELEY LAB,BERKELEY,CA 94720. IBM CORP,THOMAS J WATSON RES CTR,DIV RES,YORKTOWN HTS,NY 10598. RP Carlisle, JA (reprint author), LAWRENCE LIVERMORE NATL LAB,LIVERMORE,CA 94551, USA. NR 6 TC 12 Z9 12 U1 0 U2 1 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 0031-9007 J9 PHYS REV LETT JI Phys. Rev. Lett. PD MAR 4 PY 1996 VL 76 IS 10 BP 1762 EP 1762 DI 10.1103/PhysRevLett.76.1762 PG 1 WC Physics, Multidisciplinary SC Physics GA TX696 UT WOS:A1996TX69600054 ER PT J AU Behlke, MK Uden, PC Schantz, MM AF Behlke, MK Uden, PC Schantz, MM TI Investigations of sulfur interferences in the extraction of methylmercury from marine tissues SO ANALYTICAL COMMUNICATIONS LA English DT Article AB Gas chromatography with element-specific atomic emission detection was used to investigate sulfur interferences in the quantification of methylmercury in marine tissues. The elimination of sulfur-containing species by treatment with copper powder was confirmed by sulfur-specific atomic emission detection. C1 UNIV MASSACHUSETTS,DEPT CHEM,AMHERST,MA 01003. NIST,DIV ANALYT CHEM,GAITHERSBURG,MD 20899. NR 6 TC 8 Z9 8 U1 0 U2 0 PU ROYAL SOC CHEMISTRY PI CAMBRIDGE PA THOMAS GRAHAM HOUSE, SCIENCE PARK MILTON ROAD, CAMBRIDGE, CAMBS, ENGLAND CB4 4WF SN 1359-7337 J9 ANAL COMMUN JI Anal. Commun. PD MAR PY 1996 VL 33 IS 3 BP 91 EP 92 DI 10.1039/ac9963300091 PG 2 WC Chemistry, Analytical SC Chemistry GA UE375 UT WOS:A1996UE37500002 ER PT J AU Evans, CJ Kestner, RN AF Evans, CJ Kestner, RN TI Test optics error removal SO APPLIED OPTICS LA English DT Article DE optical testing; interferometers; Zernike polynomials ID ABSOLUTE AB Wave-front or surface errors may be divided into rotationally symmetric and nonrotationally symmetric terms. It is shown that if either the test part or the reference surface in an interferometric test is rotated to N equally spaced positions about the optical axis and the resulting wave fronts are averaged, then errors in the rotated member with angular orders that are not integer multiples of the number of positions will be removed. Thus if the test piece is rotated to N equally spaced positions and the data rotated back to a common orientation in software, all nonrotationally symmetric errors of the interferometer except those of angular order kN theta are completely removed. It is also shown how this method may be applied in an absolute test, giving both rotationally symmetric and nonsymmetric components of the surface. A general proof is given that assumes only that the surface or wave-front information can be described by some arbitrary set of orthognal polynomials in a radial coordinate r and terms in sin theta and cos theta. A simulation, using Zernike polynomials, is also presented. C1 TINSLEY LABS INC,RICHMOND,CA 94806. RP Evans, CJ (reprint author), NATL INST STAND & TECHNOL,DIV PRECIS ENGN,GAITHERSBURG,MD 20899, USA. NR 20 TC 111 Z9 126 U1 2 U2 13 PU OPTICAL SOC AMER PI WASHINGTON PA 2010 MASSACHUSETTS AVE NW, WASHINGTON, DC 20036 SN 0003-6935 J9 APPL OPTICS JI Appl. Optics PD MAR 1 PY 1996 VL 35 IS 7 BP 1015 EP 1021 DI 10.1364/AO.35.001015 PG 7 WC Optics SC Optics GA UA058 UT WOS:A1996UA05800002 PM 21085207 ER PT J AU Gentile, TR Houston, JM Hardis, JE Cromer, CL Parr, AC AF Gentile, TR Houston, JM Hardis, JE Cromer, CL Parr, AC TI National Institute of Standards and Technology high-accuracy cryogenic radiometer SO APPLIED OPTICS LA English DT Article DE radiometry; cryogenic; National Institute of Standards and Technology; standards; electrical substitution ID DETECTOR AB A high-accuracy cryogenic radiometer has been developed at the National Institute of Standards and Technology to serve as a primary standard for optical power measurements. This instrument is an electrical-substitution radiometer that can be operated at cryogenic temperatures to achieve a relative standard uncertainty of 0.021% at an optical power level of 0.8 mW. The construction and operation of the high-accuracy cryogenic radiometer and the uncertainties in optical power measurements are detailed. RP Gentile, TR (reprint author), NATL INST STAND & TECHNOL,GAITHERSBURG,MD 20899, USA. NR 20 TC 95 Z9 110 U1 4 U2 9 PU OPTICAL SOC AMER PI WASHINGTON PA 2010 MASSACHUSETTS AVE NW, WASHINGTON, DC 20036 SN 0003-6935 J9 APPL OPTICS JI Appl. Optics PD MAR 1 PY 1996 VL 35 IS 7 BP 1056 EP 1068 DI 10.1364/AO.35.001056 PG 13 WC Optics SC Optics GA UA058 UT WOS:A1996UA05800010 PM 21085215 ER PT J AU Horvath, JJ Glazier, SA AF Horvath, JJ Glazier, SA TI Fluorescence measurement of tetracycline in model fermentation media samples containing Streptomyces aureofaciens cell mass SO APPLIED SPECTROSCOPY LA English DT Article DE fluorescence; fermentation monitoring; fiber-optic sensor; tetracycline ID CULTURE FLUORESCENCE; NADH AB This study describes fluorescence measurements made with a fiberoptic probe on model fermentation media samples containing natural media components, high densities of Streptomyces aureofaciens cell mass, and varying concentrations of tetracycline. Tetracycline, produced commercially from S. aureofaciens, is a highly fluorescent antibiotic, and these measurements were conducted to determine the correlation between the tetracycline content in the media and the observed fluorescence of the samples. Seven separate types of media samples were examined for this study. Each medium contained a nonfluorescent base of nutrients and salts along with one of seven different natural feedstocks at a concentration of 50 g/L. In addition, the samples contained S. aureofaciens cell mass densities of 50 gn (based on dry cell mass). Excitation wavelengths of 290 nm, 390 nm, and 413 nm were used to probe the fluorescence of the samples, and emission spectra were obtained over the wavelength ranges of 320-360 nm, 420-600 nm, and 440-600 nm, respectively. Background fluorescence observed in the region of 320-360 nm upon 290-nm excitation in the samples was due to tryptophan fluorescence contained in the S. aureofaciens cell mass and was found to decrease dramatically as tetracycline levels increased from 0 to 8000 mu g/mL. Plots of fluorescence intensity at a number of emission wavelengths versus tetracycline concentration in the samples clearly revealed strong correlations. RP Horvath, JJ (reprint author), NATL INST STAND & TECHNOL,DIV BIOTECHNOL,GAITHERSBURG,MD 20899, USA. NR 15 TC 3 Z9 3 U1 2 U2 2 PU SOC APPLIED SPECTROSCOPY PI FREDERICK PA PO BOX 1438, FREDERICK, MD 21701 SN 0003-7028 J9 APPL SPECTROSC JI Appl. Spectrosc. PD MAR PY 1996 VL 50 IS 3 BP 327 EP 333 DI 10.1366/0003702963906267 PG 7 WC Instruments & Instrumentation; Spectroscopy SC Instruments & Instrumentation; Spectroscopy GA TZ437 UT WOS:A1996TZ43700007 ER PT J AU Wirth, EF Scott, GI Fulton, MH VanDolah, RF Maier, PP Hadley, N Daugomah, JW Key, PB AF Wirth, EF Scott, GI Fulton, MH VanDolah, RF Maier, PP Hadley, N Daugomah, JW Key, PB TI In situ monitoring of dredged material spoil sites using the oyster Crassostrea virginica SO ARCHIVES OF ENVIRONMENTAL CONTAMINATION AND TOXICOLOGY LA English DT Article ID ELEMENTS; SALINITY; METALS AB In situ and laboratory bioassays using the eastern oyster, Crassostrea virginica, were undertaken in the Wright River Estuary, South Carolina, to determine the toxic potential of effluent and sediment from recently dredged sediments. Current standards (ASTM, USEPA, and USAGE) rely solely on laboratory-based bioassays to assess toxicity of dredge spoils prior to disposal. These bioassays do not necessarily replicate the natural physicochemical estuarine processes, limiting the environmental realism of this approach. In this study, oysters were collected from a site on Leadenwah Creek (SC) and deployed in plastic cages anchored above the sediment and within the intertidal zone for 90 days at four dredge spoil disposal areas (18 sites total, one bushel/site). Oysters were also deployed at a reference site (New River Estuary, SC) and the original collection site. Trace metals and polycyclic aromatic hydrocarbons (PAHs) in tissue, sediment, and effluent samples as well as the assessment of oyster health in adults (% mortality and % reduction in potential yield) and larvae; (larval development) were measured. Results indicated high arsenic concentrations in surface water samples (<10 to 147 mu g/L), some of which exceeded the USEPA chronic marine water quality criteria and sediment concentrations (<1.0-82.2 mg/kg), which also exceeded the ERM (70 mg/kg) and the ERL (8.2 mg/kg) for arsenic, and which may have contributed to the toxic response seen in deployed oysters. A positive relationship was also seen between the in situ percent reduction in potential yield and laboratory-derived data from larval oyster development bioassays. The advantage of the combined in situ/laboratory approach used in this study is the ability to resolve probable factors influencing the toxicity of these effluents to oysters. C1 S CAROLINA DEPT NAT RESOURCES,CHARLESTON,SC 29422. RP Wirth, EF (reprint author), NOAA,NATL MARINE FISHERIES SERV,SE FISHERIES SCI CTR,POB 12607,CHARLESTON,SC 29422, USA. NR 33 TC 11 Z9 11 U1 0 U2 7 PU SPRINGER VERLAG PI NEW YORK PA 175 FIFTH AVE, NEW YORK, NY 10010 SN 0090-4341 J9 ARCH ENVIRON CON TOX JI Arch. Environ. Contam. Toxicol. PD MAR PY 1996 VL 30 IS 3 BP 340 EP 348 PG 9 WC Environmental Sciences; Toxicology SC Environmental Sciences & Ecology; Toxicology GA UC477 UT WOS:A1996UC47700006 ER PT J AU McInnes, LM Quinn, PK Covert, DS Anderson, TL AF McInnes, LM Quinn, PK Covert, DS Anderson, TL TI Gravimetric analysis, ionic composition, and associated water mass of the marine aerosol SO ATMOSPHERIC ENVIRONMENT LA English DT Article DE aerosol mass; ionic composition; aerosol water; submicrometer particles; Pacific atmosphere; sea salt; sulfate particles ID PARTICLES; SYSTEM; SULFUR AB Measurements of the total aerosol mass and ionic composition were obtained for submicrometer (D-p less than or equal to 1.0 mu m) aerosol particles from the remote Pacific boundary layer by gravimetric and ion chromatography analysis. Discrepancies were found to exist between the absolute mass determined by the separate techniques suggesting aerosol components in addition to sea salt and sulfate particles exist at significant mass concentrations. The gravimetric mass was equal to or significantly larger than the sum of the ionic masses, suggesting additional aerosol components contribute between 0 and 75% of the submicrometer aerosol mass. Measurements of the elemental composition of individual particles by electron microscopy confirmed the presence of mineral and carbonaceous particles which contributed 0-86% of the total number concentration for the particle-size range of interest. The relative number of submicrometer sulfate particles with respect to the total was low during periods with the largest discrepancy between the gravimetric and ionic mass. The amount of water associated with the submicrometer aerosol at 47% relative humidity made up 29% of the total aerosol mass collected on the filters (and 9% of the total mass at 35%). Laboratory studies determined the relative amount of water associated with sea salt, sulfate, and sodium chloride particles on a filter substrate, with sea-salt particles containing 27% water and ammonium sulfate particles containing only 4% water at 40% r.h. C1 NOAA,PACIFIC MARINE ENVIRONM LAB,SEATTLE,WA 98115. UNIV WASHINGTON,DEPT ATMOSPHER SCI,SEATTLE,WA 98195. RP McInnes, LM (reprint author), NOAA,CLIMATE MONITORING & DIAGNOST LAB,R-E-CG1,325 BROADWAY,BOULDER,CO 80303, USA. RI Quinn, Patricia/R-1493-2016 OI Quinn, Patricia/0000-0003-0337-4895 NR 28 TC 48 Z9 48 U1 0 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 MAR PY 1996 VL 30 IS 6 BP 869 EP 884 DI 10.1016/1352-2310(95)00354-1 PG 16 WC Environmental Sciences; Meteorology & Atmospheric Sciences SC Environmental Sciences & Ecology; Meteorology & Atmospheric Sciences GA TT654 UT WOS:A1996TT65400005 ER PT J AU Keene, WC Jacob, DJ Fan, SM AF Keene, WC Jacob, DJ Fan, SM TI Reactive chlorine: A potential sink for dimethylsulfide and hydrocarbons in the marine boundary layer SO ATMOSPHERIC ENVIRONMENT LA English DT Article C1 HARVARD UNIV,DIV APPL SCI,CAMBRIDGE,MA 02138. HARVARD UNIV,DEPT EARTH & PLANETARY SCI,CAMBRIDGE,MA 02138. PRINCETON UNIV,ATMOSPHER & OCEAN SCI PROGRAM,PRINCETON,NJ 08544. RP Keene, WC (reprint author), UNIV VIRGINIA,DEPT ENVIRONM SCI,CLARK HALL,CHARLOTTESVILLE,VA 22903, USA. NR 0 TC 48 Z9 48 U1 2 U2 4 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 MAR PY 1996 VL 30 IS 6 BP R1 EP R3 PG 3 WC Environmental Sciences; Meteorology & Atmospheric Sciences SC Environmental Sciences & Ecology; Meteorology & Atmospheric Sciences GA TT654 UT WOS:A1996TT65400018 ER PT J AU Solow, AR Palka, D AF Solow, AR Palka, D TI On Bayesian estimation of group size SO BIOMETRICS LA English DT Article DE binomial distribution; sighting probability; vague prior ID N-ESTIMATORS; BINOMIAL-DISTRIBUTION AB In estimating the size of a group of animals, it is commonly the case that the sighting probability for individuals is less than one. If each individual in the group is independently sighted with equal probability, the problem is one of estimating the number of trials from the number of successes in one or more binomial experiments. In many cases, some individuals in the group have unit sighting probability, whereas others do not. This note describes the Bayesian estimation of group size for this case. C1 NATL MARINE FISHERIES SERV,NE FISHERIES SCI CTR,WOODS HOLE,MA 02543. RP Solow, AR (reprint author), WOODS HOLE OCEANOG INST,WOODS HOLE,MA 02543, USA. NR 7 TC 1 Z9 1 U1 0 U2 0 PU INTERNATIONAL BIOMETRIC SOC PI WASHINGTON PA 808 17TH ST NW SUITE 200, WASHINGTON, DC 20006-3910 SN 0006-341X J9 BIOMETRICS JI Biometrics PD MAR PY 1996 VL 52 IS 1 BP 335 EP 340 DI 10.2307/2533171 PG 6 WC Biology; Mathematical & Computational Biology; Statistics & Probability SC Life Sciences & Biomedicine - Other Topics; Mathematical & Computational Biology; Mathematics GA UF292 UT WOS:A1996UF29200033 ER PT J AU Nivinskas, H Cole, KD AF Nivinskas, H Cole, KD TI Environmentally benign staining procedure for electrophoresis gels using coomassie brilliant blue SO BIOTECHNIQUES LA English DT Article ID POLYACRYLAMIDE GELS; ONE-STEP; PROTEINS RP Nivinskas, H (reprint author), NIST,BLDG 222,ROOM A353,GAITHERSBURG,MD 20899, USA. NR 12 TC 13 Z9 14 U1 0 U2 1 PU EATON PUBLISHING CO PI NATICK PA 154 E. CENTRAL ST, NATICK, MA 01760 SN 0736-6205 J9 BIOTECHNIQUES JI Biotechniques PD MAR PY 1996 VL 20 IS 3 BP 380 EP & PG 4 WC Biochemical Research Methods; Biochemistry & Molecular Biology SC Biochemistry & Molecular Biology GA TY801 UT WOS:A1996TY80100011 PM 8679192 ER PT J AU Smith, SD Fairall, CW Geernaert, GL Hasse, L AF Smith, SD Fairall, CW Geernaert, GL Hasse, L TI Air-sea fluxes: 25 years of progress SO BOUNDARY-LAYER METEOROLOGY LA English DT Review ID SURFACE WIND STRESS; INERTIAL-DISSIPATION METHOD; EQUATORIAL PACIFIC-OCEAN; PLANETARY BOUNDARY-LAYER; LATENT-HEAT FLUX; LARGE-EDDY-SIMULATION; ICE-ZONE EXPERIMENT; AIRCRAFT OBSERVATIONS; TURBULENT FLUXES; DRAG COEFFICIENT AB During the past quarter century the study of air-sea interaction has evolved from a small branch of marine climatology to play a key role in the modelling of the coupled system of ocean and atmosphere. Knowledge of air-sea fluxes has grown, based on Monin-Obukhov similarity theory for surface boundary layers and on direct and indirect techniques of measuring the fluxes. This has been the basis for providing boundary conditions needed to couple atmospheric and oceanic circulation models that are used to forecast weather and climate. An overview of current understanding is followed by a discussion of parameterisation schemes and a chronicle of some of the experimental work that has tested theories and quantified their conclusions. C1 NOAA, ENVIRONM TECHNOL LAB, BOULDER, CO 80303 USA. NATL ENVIRONM RES INST, DEPT EMISS & AIR POLLUT, DK-4000 ROSKILDE, DENMARK. CHRISTIAN ALBRECHTS UNIV KIEL, INST MEERESKUNDE, D-24105 KIEL, GERMANY. RP FISHERIES & OCEANS CANADA, BEDFORD INST OCEANOG, DARTMOUTH, NS B2Y 4A2, CANADA. NR 215 TC 53 Z9 54 U1 1 U2 9 PU SPRINGER PI DORDRECHT PA VAN GODEWIJCKSTRAAT 30, 3311 GZ DORDRECHT, NETHERLANDS SN 0006-8314 EI 1573-1472 J9 BOUND-LAY METEOROL JI Bound.-Layer Meteor. PD MAR PY 1996 VL 78 IS 3-4 BP 247 EP 290 DI 10.1007/BF00120938 PG 44 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA VB072 UT WOS:A1996VB07200002 ER PT J AU Wilczak, JM Gossard, EE Neff, WD Eberhard, WL AF Wilczak, JM Gossard, EE Neff, WD Eberhard, WL TI Ground-based remote sensing of the atmospheric boundary layer: 25 years of progress SO BOUNDARY-LAYER METEOROLOGY LA English DT Review ID SURFACE HEAT-FLUX; WIND PROFILER; DOPPLER LIDAR; WATER-VAPOR; CLOUD PROPERTIES; RAMAN LIDAR; ENTRAINMENT ZONE; PLUME DISPERSION; DUAL-DOPPLER; RADAR AB The role of ground-based remote sensors in boundary-layer research is reviewed, emphasizing the contributions of radars, sodars, and lidars. The review begins with a brief comparison of the state of remote sensors in boundary-layer research 25 years ago with its present-day status. Next, a summary of the current capabilities of remote sensors for boundary-layer studies demonstrates that for boundary-layer depth and for profiles of many mean quantities, remote sensors offer some of the most accurate measurements available. Similar accuracies are in general not found for most turbulence parameters. Important contributions of remote sensors to our understanding of the structure and dynamics of various boundary-layer phenomena or processes are then discussed, including the sea breeze, convergence boundaries, dispersion, and boundary-layer cloud systems. The review concludes with a discussion of the likely future role of remote sensors in boundary-layer research. RP NOAA, ENVIRONM RES LABS, ENVIRONM TECHNOL LAB, 325 BROADWAY, BOULDER, CO 80303 USA. RI Neff, William/E-2725-2010; Eberhard, Wynn/B-5402-2015 OI Neff, William/0000-0003-4047-7076; NR 128 TC 45 Z9 48 U1 3 U2 24 PU SPRINGER PI DORDRECHT PA VAN GODEWIJCKSTRAAT 30, 3311 GZ DORDRECHT, NETHERLANDS SN 0006-8314 EI 1573-1472 J9 BOUND-LAY METEOROL JI Bound.-Layer Meteor. PD MAR PY 1996 VL 78 IS 3-4 BP 321 EP 349 DI 10.1007/BF00120940 PG 29 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA VB072 UT WOS:A1996VB07200004 ER PT J AU Bowen, WJ Engel, DW AF Bowen, WJ Engel, DW TI Effects of protracted cadmium exposure on gametes of the purple sea urchin, Arbacia punctulata SO BULLETIN OF ENVIRONMENTAL CONTAMINATION AND TOXICOLOGY LA English DT Article ID COMPARATIVE SENSITIVITY; METALS C1 NOAA,SE FISHERIES SCI CTR,NATL MARINE FISHERIES SERV,BEAUFORT LAB,BEAUFORT,NC 28516. NR 16 TC 9 Z9 9 U1 0 U2 1 PU SPRINGER VERLAG PI NEW YORK PA 175 FIFTH AVE, NEW YORK, NY 10010 SN 0007-4861 J9 B ENVIRON CONTAM TOX JI Bull. Environ. Contam. Toxicol. PD MAR PY 1996 VL 56 IS 3 BP 493 EP 499 PG 7 WC Environmental Sciences; Toxicology SC Environmental Sciences & Ecology; Toxicology GA TM935 UT WOS:A1996TM93500022 PM 8825975 ER PT J AU Kalnay, E Kanamitsu, M Kistler, R Collins, W Deaven, D Gandin, L Iredell, M Saha, S White, G Woollen, J Zhu, Y Chelliah, M Ebisuzaki, W Higgins, W Janowiak, J Mo, KC Ropelewski, C Wang, J Leetmaa, A Reynolds, R Jenne, R Joseph, D AF Kalnay, E Kanamitsu, M Kistler, R Collins, W Deaven, D Gandin, L Iredell, M Saha, S White, G Woollen, J Zhu, Y Chelliah, M Ebisuzaki, W Higgins, W Janowiak, J Mo, KC Ropelewski, C Wang, J Leetmaa, A Reynolds, R Jenne, R Joseph, D TI The NCEP/NCAR 40-year reanalysis project SO BULLETIN OF THE AMERICAN METEOROLOGICAL SOCIETY LA English DT Article ID SEA-SURFACE TEMPERATURES; SOUTHERN OSCILLATION; SOIL HYDROLOGY; PRECIPITATION; SYSTEM; RAINFALL; MODEL; INDIA; NMC AB The NCEP and NCAR are cooperating in a project (denoted ''reanalysis'') to produce a 40-year record of global analyses of atmospheric fields in support of the needs of the research and climate monitoring communities. This effort involves the recovery of land surface, ship, rawinsonde, pibal, aircraft, satellite, and other data; quality controlling and assimilating these data with a data assimilation system that is kept unchanged over the reanalysis period 1957-96. This eliminates perceived climate jumps associated with changes in the data assimilation system. The NCEP/NCAR 40-yr reanalysis uses a frozen state-of-the-art global data assimilation system and a database as complete as possible. The data assimilation and the model used are identical to the global system implemented operationally at the NCEP on 11 January 1995, except that the horizontal resolution is T62 (about 210 km). The database has been enhanced with many sources of observations not available in real time for operations, provided by different countries and organizations. The system has been designed with advanced quality control and monitoring components, and can produce 1 mon of reanalysis per day on a Gray YMP/8 supercomputer. Different types of output archives are being created to satisfy different user needs, including a ''quick look'' CD-ROM (one per year) with six tropospheric and stratospheric fields available twice daily, as well as surface, top-of-the atmosphere, and isentropic fields. Reanalysis information and selected output is also available on-line via the Internet (http//:nic.fb4.noaa.gov:8000). A special CDROM, containing 13 years of selected observed, daily, monthly, and climatological data from the NCEP/NCAR Reanalysis, is included with this issue. Output variables are classified into four classes, depending on the degree to which they are influenced by the observations and/or the model. For example, ''C'' variables (such as precipitation and surface fluxes) are completely determined by the model during the data assimilation and should be used with caution. Nevertheless, a comparison of these variables with observations and with several climatologies shows that they generally contain considerable useful information. Eight-day forecasts, produced every 5 days, should be useful for predictability studies and for monitoring the quality of the observing systems. The 40 years of reanalysis (1957-96) should be completed in early 1997. A continuation into the future through an identical Climate Data Assimilation System will allow researchers to reliably compare recent anomalies with those in earlier decades. Since changes in the observing systems will inevitably produce perceived changes in the climate, parallel reanalyses (at least 1 year long) will be generated for the periods immediately after the introduction of new observing systems, such as new types of satellite data. NCEP plans currently call for an updated reanalysis using a state-of-the-art system every five years or so. The successive reanalyses will be greatly facilitated by the generation of the comprehensive database in the present reanalysis. C1 NATL CTR ENVIRONM PREDICT,CLIMATE PREDICT CTR,WASHINGTON,DC 20233. NATL CTR ATMOSPHER RES,BOULDER,CO 80307. RP Kalnay, E (reprint author), NATL CTR ENVIRONM PREDICT,ENVIRONM MODELING CTR,W NMCZ,ROOM 204 WWB,WASHINGTON,DC 20233, USA. RI Kalnay, Eugenia/F-4393-2010; Wang, Julian/C-3188-2016; OI Kalnay, Eugenia/0000-0002-9984-9906 NR 59 TC 14987 Z9 16161 U1 180 U2 1125 PU AMER METEOROLOGICAL SOC PI BOSTON PA 45 BEACON ST, BOSTON, MA 02108-3693 SN 0003-0007 J9 B AM METEOROL SOC JI Bull. Amer. Meteorol. Soc. PD MAR PY 1996 VL 77 IS 3 BP 437 EP 471 DI 10.1175/1520-0477(1996)077<0437:TNYRP>2.0.CO;2 PG 35 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA UG176 UT WOS:A1996UG17600001 ER PT J AU Livezey, RE Masutani, M Ji, M AF Livezey, RE Masutani, M Ji, M TI SST-forced seasonal simulation and prediction skill for versions of the NCEP/MRF model SO BULLETIN OF THE AMERICAN METEOROLOGICAL SOCIETY LA English DT Article ID VERIFICATION; PATTERNS AB The feasibility of using a two-tier approach to provide guidance to operational long-lead seasonal prediction is explored. The approach includes first a forecast of global sea surface temperatures (SSTs) using a coupled general circulation model, followed by an atmospheric forecast using an atmospheric general circulation model (AGCM). For this exploration, ensembles of decade-long integrations of the AGCM driven by observed SSTs and ensembles of integra tions of select cases driven by forecast SSTs have been conducted. The ability of the model in these sets of runs to reproduce observed atmospheric conditions has been evaluated with a multiparameter performance analysis. Results have identified performance and skill levels in the specified SST runs, for winters and springs over the Pacific/North America region, that are sufficient to impact operational seasonal predictions in years with major El Nino-Southern Oscillation (ENSO) episodes. Further, these levels were substantially reproduced in the forecast SST runs for I-month leads and in many instances for up to one-season leads. In fact: overall the 0- and I-month-lead forecasts of seasonal temperature over the United States for three falls and winters with major ENSO episodes were substantially better than corresponding official forecasts. Thus, there is considerable reason to develop a dynamical component for the official seasonal forecast process. C1 NOAA,NWS,NCEP,CLIMATE PREDICT CTR,WASHINGTON,DC. RES & DATA SYST CORP,GREENBELT,MD. NOAA,NWS,NCEP,ENVIRONM MODELING CTR,WASHINGTON,DC. NR 23 TC 41 Z9 41 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 MAR PY 1996 VL 77 IS 3 BP 507 EP 517 DI 10.1175/1520-0477(1996)077<0507:SFSSAP>2.0.CO;2 PG 11 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA UG176 UT WOS:A1996UG17600004 ER PT J AU Barnes, SL Caracena, F Marroquin, A AF Barnes, SL Caracena, F Marroquin, A TI Extracting synoptic-scale diagnostic information from mesoscale models: The eta model, gravity waves, and quasigeostrophic diagnostics SO BULLETIN OF THE AMERICAN METEOROLOGICAL SOCIETY LA English DT Article ID STEP-MOUNTAIN COORDINATE; CLOSURE MODELS; CYCLOGENESIS; SCHEME AB Fine-mesh models, such as the eta model, are producing increasingly detailed predictions about mesoscale atmospheric motions. Mesoscale systems typically produce stronger vertical motions than do synoptic-scale storms, making it more difficult for forecasters to assess the strength of the latter's dynamics when the signals are overwhelmed by mesoscale processes. This paper describes a method for extracting synoptic-scale information from mesoscale model data. Predicted height fields from the 29-km eta model are investigated to determine the filtering and smoothing requirements necessary to resolve synoptic-scale patterns of vertical motions using quasigeostrophic (QG) diagnostics. The selected late-fall case includes a jet stream that enters the continent over the Pacific Northwest, resulting in orographically induced troughs in the lee of the Cascade Range and Rocky Mountains. Gravity waves are found to emanate from this region in area that reach Hudson Bay to the northeast and extend to the Caribbean in the southeast. Individual gravity wave crests (similar to 240 km apart) are of sufficient amplitude (5 to 10 m at 500 mb) to dominate the expected synoptic-scale vertical motions by two orders of magnitude. A numerical filter based on a two-dimensional diffraction function is designed, tested, and found to eliminate the influence of the gravity waves effectively. The filtered model data are then able to reveal synoptic-scale vertical motion patterns in all areas except the vicinity of the lee troughs, which still dominate QG forcing near the jet axis. C1 COOPERAT INST RES ATMOSPHERE,FT COLLINS,CO. RP Barnes, SL (reprint author), NOAA,ERL,FORECAST SYST LAB,MAIL CODE R-E-FS1,325 BROADWAY,BOULDER,CO 80303, USA. NR 21 TC 32 Z9 32 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 MAR PY 1996 VL 77 IS 3 BP 519 EP 528 DI 10.1175/1520-0477(1996)077<0519:ESSDIF>2.0.CO;2 PG 10 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA UG176 UT WOS:A1996UG17600005 ER PT J AU Willoughby, HE Black, PG AF Willoughby, HE Black, PG TI Hurricane Andrew in Florida: Dynamics of a disaster SO BULLETIN OF THE AMERICAN METEOROLOGICAL SOCIETY LA English DT Article ID TROPICAL CYCLONE INTENSITY; ANGULAR-MOMENTUM FLUXES; LANDFALL; EVOLUTION; SEASON AB Four meteorological factors aggravated the devastation when Hurricane Andrew struck South Florida: completed replacement of the original eyewall by an outer, concentric eyewall while Andrew was still at sea; storm translation so fast that the eye crossed the populated coastline before the influence of land could weaken it appreciably; extreme wind speed, 82 m s(-1) winds measured by aircraft flying at 2.5 km; and formation of an intense, but nontomadic, convective vortex in the eyewall at the time of landfall. Although Andrew weakened for 12 h during the eyewall replacement, it contained vigorous convection and was reintensifying rapidly as it passed onshore. The Gulf Stream just offshore was warm enough to support a sea level pressure 20-30 hPa lower than the 922 hPa attained, but Andrew hit land before it could reach this potential. The difficult-to-predict mesoscale and vortex-scale phenomena determined the course of events on that windy morning, not a long-term trend toward worse hurricanes. RP Willoughby, HE (reprint author), NOAA,ATLANTIC OCEANOG & METEOROL LAB,HURRICANE RES DIV,4301 RICKENBACKER CAUSEWAY,MIAMI,FL 33149, USA. NR 41 TC 76 Z9 78 U1 2 U2 5 PU AMER METEOROLOGICAL SOC PI BOSTON PA 45 BEACON ST, BOSTON, MA 02108-3693 SN 0003-0007 J9 B AM METEOROL SOC JI Bull. Amer. Meteorol. Soc. PD MAR PY 1996 VL 77 IS 3 BP 543 EP 549 DI 10.1175/1520-0477(1996)077<0543:HAIFDO>2.0.CO;2 PG 7 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA UG176 UT WOS:A1996UG17600007 ER PT J AU Hobson, ES Chess, JR Howard, DF AF Hobson, ES Chess, JR Howard, DF TI Zooplankters consumed by blue rockfish during brief access to a current off California's Sonoma coast SO CALIFORNIA FISH AND GAME LA English DT Article ID SEBASTES RP Hobson, ES (reprint author), SW FISHERIES SCI CTR,TIBURON LAB,3150 PARADISE DR,TIBURON,CA 94920, USA. NR 7 TC 3 Z9 4 U1 0 U2 1 PU CALIF FISH AND GAME EDITOR PI SACRAMENTO PA 1416 NINTH ST, SACRAMENTO, CA 95814 SN 0008-1078 J9 CALIF FISH GAME JI Calif. Fish Game PD SPR PY 1996 VL 82 IS 2 BP 87 EP 92 PG 6 WC Fisheries; Zoology SC Fisheries; Zoology GA WB768 UT WOS:A1996WB76800004 ER PT J AU Jacobson, LD Vetter, RD AF Jacobson, LD Vetter, RD TI Bathymetric demography and niche separation of thornyhead rockfish: Sebastolobus alascanus and Sebastolobus altivelis SO CANADIAN JOURNAL OF FISHERIES AND AQUATIC SCIENCES LA English DT Article ID OXYGEN-MINIMUM ZONE; MICROSTOMUS-PACIFICUS; DIFFERENT DEPTHS; DOVER SOLE; FISHES; CONSUMPTION; MATURITY AB Bottom trawl fisheries along western North America have expanded into deep water to take shortspine (Sebastolobus alascanus) and longspine (Sebastolobus altivelis) thornyheads. We studied the bathymetric demography and ecology of both species off Oregon and central California. Thornyhead species cannot be characterized as shallow- and deep-living congeners because the peak spawning biomass for both occurred in the oxygen minimum zone at 600-1000 m. Small shortspine thornyhead (less than or equal to 10 cm) were found in shallow water (200-600 m) but migrated into deeper water with growth. Longspine thornyhead were oxygen minimum zone specialists found only in deep water (600-1400 m). Shortspine thornyhead grew larger (>70 cm) and appeared to grow throughout their lives. Longspine thornyhead were smaller (25-30 cm) and appeared to have an asymptotic growth pattern with many age groups in the largest size-classes. Bathymetric demography reduces the potential for interspecific competition because shortspine and longspine thornyheads of similar size live at different depths. There are opportunities for refugium management in the fishery because eliminating fishing deeper than 600-800 m would protect the spawning biomass of thornyheads, Dover sole (Microstomus pacificus), and sablefish (Anoplopoma fimbria). RP Jacobson, LD (reprint author), NATL MARINE FISHERIES SERV, SW FISHERIES SCI CTR, 8605 LA JOLLA SHORES DR, LA JOLLA, CA 92038 USA. NR 33 TC 35 Z9 35 U1 0 U2 5 PU CANADIAN SCIENCE PUBLISHING, NRC RESEARCH PRESS PI OTTAWA PA 1200 MONTREAL ROAD, BUILDING M-55, OTTAWA, ON K1A 0R6, CANADA SN 0706-652X J9 CAN J FISH AQUAT SCI JI Can. J. Fish. Aquat. Sci. PD MAR PY 1996 VL 53 IS 3 BP 600 EP 609 DI 10.1139/cjfas-53-3-600 PG 10 WC Fisheries; Marine & Freshwater Biology SC Fisheries; Marine & Freshwater Biology GA UU213 UT WOS:A1996UU21300018 ER PT J AU Fahr, A Nayak, A AF Fahr, A Nayak, A TI Temperature dependent ultraviolet absorption cross sections of propylene, methylacetylene and vinylacetylene SO CHEMICAL PHYSICS LA English DT Article ID VOYAGER INFRARED OBSERVATIONS; INTERSTELLAR CLOUDS; TITANS ATMOSPHERE; SCATTERED-LIGHT; GAS AB The temperature dependence of the UV absorption cross sections of propylene (CH3CH=CH2) and methylacetylene (CH3C=CH) from 160 to 200 nm and vinylacetylene (CH2=CHC=CH) from 160 to 240 nm have been measured in the gas phase, for temperatures ranging from about 220 to 330 K. The propylene spectrum, exhibits a broad absorption band with a maximum at 172.0 nm with some structure to the short wavelength side of the broad band. At the absorption peaks a small increase (about 5%) in the cross sections has been observed with decreasing temperature from 333 to 233 K. At the long wavelength tail of the absorption band the cross sections are found to decrease with decreasing temperature. The absorption spectrum of methylacetylene in the region of 160 to 200 nm consists of a broad continuum with a maximum at 172.4 nm. The cross section values, for methylacetylene, near the absorption peak are found to remain nearly independent of temperature, However, at the long wavelength side of the absorption band the cross sections increase with increasing temperature. The spectrum of vinylacetylene consists of a very strong and structured absorption in the 160 to 170 nm region and strong diffuse bands between around 190 and 230 nm. The cross section values at the absorption peaks, determined at low temperatures, are significantly higher than those at higher temperatures, A sharp absorption feature at 168.2 nm shows the most pronounced temperature effect, with an increase in cross section from 35.86 X 10(-18) to 63.54 X 10(-18) cm(2) for a temperature change of 333 to 223 K. RP Fahr, A (reprint author), NIST,DIV CHEM KINET & THERMODYNAM,GAITHERSBURG,MD 20899, USA. NR 30 TC 34 Z9 34 U1 0 U2 13 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0301-0104 J9 CHEM PHYS JI Chem. Phys. PD MAR 1 PY 1996 VL 203 IS 3 BP 351 EP 358 DI 10.1016/0301-0104(95)00401-7 PG 8 WC Chemistry, Physical; Physics, Atomic, Molecular & Chemical SC Chemistry; Physics GA TX255 UT WOS:A1996TX25500005 ER PT J AU Jackson, CL Bauer, BJ Nakatani, AI Barnes, JD AF Jackson, CL Bauer, BJ Nakatani, AI Barnes, JD TI Synthesis of hybrid organic-inorganic materials from interpenetrating polymer network chemistry SO CHEMISTRY OF MATERIALS LA English DT Article ID COMPOSITE-MATERIALS; SILICA; TETRAETHOXYSILANE; GLASSES; ROUTES AB Organic-inorganic interpenetrating polymer networks were synthesized with an SiO2 phase made by sol-gel chemistry and the organic phase made from poly(2-hydroxyethyl acrylate). The resultant morphologies were characterized by small-angle scattering and electron microscopy. When the vinyl polymerization is more rapid than the sol-gel reaction, gross phase separation occurs giving a heterogeneous structure. For comparable rates of the two polymerizations, the specimens have a dendritic morphology on the scale of 0.5 mu m. The more rapid formation of the silica phase relative to the organic network produces rigid and optically transparent materials, with a finely divided structure as seen by transmission electron microscopy. The glass content of these materials is about 0.15 g/g and the sizes of the SiO2-rich domains are 100 Angstrom or less. Addition of tetrakis(2-(acryloxy)ethoxy)silane was also studied and found to promote phase mixing between the organic and inorganic phases. RP Jackson, CL (reprint author), NATL INST STAND & TECHNOL,MAT SCI & ENGN LAB,GAITHERSBURG,MD 20899, USA. NR 37 TC 88 Z9 93 U1 3 U2 17 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 SN 0897-4756 J9 CHEM MATER JI Chem. Mat. PD MAR PY 1996 VL 8 IS 3 BP 727 EP 733 DI 10.1021/cm950417h PG 7 WC Chemistry, Physical; Materials Science, Multidisciplinary SC Chemistry; Materials Science GA UA826 UT WOS:A1996UA82600020 ER PT J AU Kukkonen, J Landrum, PF AF Kukkonen, J Landrum, PF TI Distribution of organic carbon and organic xenobiotics among different particle-size fractions in sediments SO CHEMOSPHERE LA English DT Article DE sediment; particle-size distribution; organic carbon; PAHs; PCBs ID POLYCYCLIC AROMATIC-HYDROCARBONS; AMPHIPOD PONTOPOREIA-HOYI; HYDROPHOBIC POLLUTANTS; HUMIC SUBSTANCES; SORPTION; WATER; BIOAVAILABILITY; ADSORPTION; MATTER; FLUORANTHENE AB The distributions of benzo[a]pyrene, hexachlorobiphenyl, and total organic carbon in a Lake Michigan sediment and a Florissant soil sample were determined and related to the known bioavailability of the compounds. The distribution of organic compounds among small particles (<63 mu m diameter) was different from the distribution of the total organic carbon. However, the organic matter remained the major sorbent or these compounds. Changing the fractionation conditions, by performing the fractionation in distilled water instead of natural lake water, altered the distributions for both organic carbon and xenobiotics among the particles. Further, the contaminant distribution relative to organic carbon content differed between particle-size fractions and between contaminants of different compound classes, e.g., PAHs and PCBs. The differential distribution of the contaminants in the particle-size fractions likely contributed to the observed differences in bioavailability of organic contaminants for benthic organisms and may be exacerbated by selective feeding. C1 NOAA,GREAT LAKES ENVIRONM RES LAB,ANN ARBOR,MI 48105. RP Kukkonen, J (reprint author), UNIV JOENSUU,DEPT BIOL,LAB AQUAT TOXICOL,POB 111,SF-80101 JOENSUU,FINLAND. NR 45 TC 58 Z9 58 U1 0 U2 10 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD, ENGLAND OX5 1GB SN 0045-6535 J9 CHEMOSPHERE JI Chemosphere PD MAR PY 1996 VL 32 IS 6 BP 1063 EP 1076 DI 10.1016/0045-6535(96)00016-1 PG 14 WC Environmental Sciences SC Environmental Sciences & Ecology GA UB399 UT WOS:A1996UB39900004 ER PT J AU Ristola, T Pellinen, J VanHoof, PL Leppanen, M Kukkonen, J AF Ristola, T Pellinen, J VanHoof, PL Leppanen, M Kukkonen, J TI Characterization of Lake Ladoga sediments .2. Toxic chemicals SO CHEMOSPHERE LA English DT Article ID POLYCYCLIC AROMATIC-HYDROCARBONS; ORGANIC CHLORINE COMPOUNDS; CONTAMINATED SEDIMENTS; DETROIT RIVER; PORE WATER; POLLUTANTS; MICHIGAN; FINLAND; CARBON AB Chemical contamination of Lake Ladoga was studied by analyzing 12 sediment samples collected at various parts of the lake for polyaromatic hydrocarbons, chlorobenzenes, organochloropesticides and heavy metals. The results were also used to explain the negative effects of these sediments observed earlier in bioassays with a midge Chironomus riparius (Ristola et al. 1995). Concentrations of analyzed chemicals were mostly typical to lakes which are considered as unpolluted. Only the concentrations of PAH were somewhat elevated in the sediment collected near River Volkhov inlet in the southern pat of the lake. Adverse effects on midges could, however, not be explained by chemical contamination. C1 NOAA,GREAT LAKES ENVIRONM RES LAB,ANN ARBOR,MI 48105. RP Ristola, T (reprint author), UNIV JOENSUU,DEPT BIOL,POB 111,SF-80101 JOENSUU,FINLAND. NR 33 TC 20 Z9 21 U1 1 U2 5 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD, ENGLAND OX5 1GB SN 0045-6535 J9 CHEMOSPHERE JI Chemosphere PD MAR PY 1996 VL 32 IS 6 BP 1179 EP 1192 DI 10.1016/0045-6535(96)00033-1 PG 14 WC Environmental Sciences SC Environmental Sciences & Ecology GA UB399 UT WOS:A1996UB39900014 ER PT J AU Krone, CA Stein, JE Varanasi, U AF Krone, CA Stein, JE Varanasi, U TI Butyltin contamination of sediments and benthic fish from the East, Gulf and Pacific coasts of the United States SO ENVIRONMENTAL MONITORING AND ASSESSMENT LA English DT Article ID ORGANOTIN COMPOUNDS; PUGET SOUND; TRIBUTYLTIN; BIVALVES; DIBUTYLTIN; METABOLISM; TISSUE; WATERS AB Butyltin concentrations were determined in sediments, tissues and stomach contents of fish collected in 41 embayments on the East, Gulf and Pacific coasts of the U.S.A. between 1986 and 1991 as part of the National Oceanic and Atmospheric Administration's (NOAA) National Benthic Surveillance Project (NBSP). A total of 99 sediments, 108 fish liver samples from 11 fish species, and 10 composites of fish stomach contents were analyzed for tetrabutylin, tributylin, dibutylin and monobutylin. Tributyltin (TBT) was detected (i.e. > 10 ng/g) in 38 of the sediments samples analyzed and was generally the predominant bulytin present; concentrations of total butyltins ranged from 15 to 1600 ng/g wet weight. The highest concentrations were found in sediments from urban sites, especially sites on the West coast. Many of the fish liver and stomach contents samples also contained butyltins. Tributyltin represented 83 (7.1)% [mean (SEM); n = 15], 64 (6.6)% (n = 12) and 36 (7.8)% (n = 12) of the total butyltins in livers from white croaker, winter flounder and Atlantic croaker, respectively, suggesting possible species differences in biotransformation of TBT. The concentrations of butyltins in stomach contents indicated that diet can be a significant route of exposure of fish to butyltins. Between 1986 and 1991 butyltin concentrations in sediments and fish generally appeared to be declining; however, no statistically significant temporal trends were observed at individual sites or for the sites overall. RP Krone, CA (reprint author), NATL MARINE FISHERIES SERV, NOAA, NW FISHERIES SCI CTR, ENVIRONM CONSERVAT DIV, 2725 MONTLAKE BLVD E, SEATTLE, WA 98112 USA. NR 24 TC 37 Z9 39 U1 0 U2 4 PU KLUWER ACADEMIC PUBL PI DORDRECHT PA SPUIBOULEVARD 50, PO BOX 17, 3300 AA DORDRECHT, NETHERLANDS SN 0167-6369 J9 ENVIRON MONIT ASSESS JI Environ. Monit. Assess. PD MAR PY 1996 VL 40 IS 1 BP 75 EP 89 DI 10.1007/BF00395168 PG 15 WC Environmental Sciences SC Environmental Sciences & Ecology GA TZ520 UT WOS:A1996TZ52000005 PM 24198072 ER PT J AU Kerr, DR Meador, JP AF Kerr, DR Meador, JP TI Modeling dose response using generalized linear models SO ENVIRONMENTAL TOXICOLOGY AND CHEMISTRY LA English DT Article DE dose response; LC50; generalized linear models; toxicity testing; LOEC ID TOXICITY TESTS AB This paper describes a method to determine and model dose-response relationships from binomial response data using generalized linear models (GLM). The main advantage of this technique is that it allows LC(p) or LD(p) to be determined without an initial linearizing transformation. (LC(p) and LD(p) are the lethal concentration or dose that causes p proportion of test animals to die at a specified time period.) Thus, the method of GLM is an appropriate way to analyze a dose-response relationship because it utilizes the inherent S-shaped feature of the toxicologic response and incorporates the sample size of each trial in parameter estimation. This method is also much better behaved when the extremes of the response probability are considered because responses of 0% and 100% are included in the model. Another advantageous feature of this method is that confidence intervals (C.I.s) for both the dose estimate and response probabilities can be computed with GLM, which provides a more complete description of the estimates and their inherent uncertainty. Because C.I.s for both the dose estimate and response probabilities can be constructed, the lowest observed effect concentration (LOEC) can also be determined. C1 NOAA,NATL MARINE FISHERIES SERV,NW FISHERIES CTR,ENVIRONM CONSERVAT DIV,SEATTLE,WA 98112. UNIV WASHINGTON,DEPT STAT,SEATTLE,WA 98195. NR 13 TC 61 Z9 66 U1 5 U2 16 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 MAR PY 1996 VL 15 IS 3 BP 395 EP 401 DI 10.1897/1551-5028(1996)015<0395:MDRUGL>2.3.CO;2 PG 7 WC Environmental Sciences; Toxicology SC Environmental Sciences & Ecology; Toxicology GA TW732 UT WOS:A1996TW73200025 ER PT J AU McCain, BB Brown, DW Hom, T Myers, MS Pierce, SM Collier, TK Stein, JE Chan, SL Varanasi, U AF McCain, BB Brown, DW Hom, T Myers, MS Pierce, SM Collier, TK Stein, JE Chan, SL Varanasi, U TI Chemical contaminant exposure and effects in four fish species from Tampa Bay, Florida SO ESTUARIES LA English DT Article ID SOLE PAROPHRYS-VETULUS; POLYCYCLIC AROMATIC-HYDROCARBONS; ENGLISH SOLE; PUGET-SOUND; HEPATIC NEOPLASMS; DNA ADDUCTS; PSEUDOPLEURONECTES-AMERICANUS; P-32-POSTLABELING ANALYSIS; WINTER FLOUNDER; BENTHIC FISH AB Concentrations of selected anthropogenic chemical contaminants and levels of pollution-related biological effects were measured during three consecutive years (1990-1992) in hardhead catfish (Arius felis), Gulf killifish (Fundulus grandis), longnose killifish (F. majalis), and red drum (Scieaenops ocellatus) from 12 subtidal and intertidal sites in Tampa Bay and nearby Sarasota Bay. Each species was collected from at least four sites. Compared to nonindustrialized sites, concentrations of PCBs, DDTs, and alpha-chlordane in liver, and of fluorescent aromatic compounds in bile, were highest in fish from sites in or near Hillsborough Bay, the most industrialized portion of Tampa Bay. The results of analyses for two biochemical markers of contaminant-induced effects in fish, hepatic cytochrome P4501A activities and levels of hepatic DNA adducts, also showed the highest levels to be in all four fish species from sites in the vicinity of Hillsborough Bay. Liver lesions, considered to be pollution-associated in several other bottom-feeding fish species, were found in hardhead catfish and longnose killifish, exclusively from sites in Hillsborough Bay. Overall, concentrations of selected contaminants and their derivatives in the four target fish species generally reflected concentrations of these contaminants found in sediment. The biochemical and histopathological responses demonstrated that chemical contaminant concentrations in the vicinity of Hillsborough Bay are sufficiently high to cause adverse effects in indigenous fish species. The results, collectively, showed that the extent of contaminant exposure and biological effects in fish from sites in Tampa Bay were low to moderate compared to more urbanized coastal sites of the United States. C1 NOAA,NATL MARINE FISHERIES SERV,NW FISHERIES SCI CTR,ENVIRONM CONSERVAT DIV,SEATTLE,WA 98112. NR 63 TC 23 Z9 23 U1 3 U2 10 PU ESTUARINE RES FEDERATION PI LAWRENCE PA PO BOX 368, LAWRENCE, KS 66044 SN 0160-8347 J9 ESTUARIES JI Estuaries PD MAR PY 1996 VL 19 IS 1 BP 86 EP 104 DI 10.2307/1352655 PG 19 WC Environmental Sciences; Marine & Freshwater Biology SC Environmental Sciences & Ecology; Marine & Freshwater Biology GA TU217 UT WOS:A1996TU21700010 ER PT J AU Friedland, KD Ahrenholz, DW Guthrie, JF AF Friedland, KD Ahrenholz, DW Guthrie, JF TI Formation and seasonal evolution of Atlantic menhaden juvenile nurseries in coastal estuaries SO ESTUARIES LA English DT Article ID BREVOORTIA-TYRANNUS PISCES; CHESAPEAKE BAY; NORTH-CAROLINA; PHYTOPLANKTON; FISH; PRODUCTIVITY; CONSUMPTION; POPULATION; CLUPEIDAE; PATTERNS AB A hypothesis on the formation and seasonal evolution of Atlantic menhaden (Brevoortia tyrannus) juvenile nurseries in coastal estuaries is described. A series of cruises were undertaken to capture postmetamorphic juvenile menhaden and to characterize several biological and physical parameters along estuarine gradients. The two study systems, the Neuse and Pamlico rivers in North Carolina, contain important menhaden nursery grounds. Juvenile menhaden abundance was found to be associated with gradients of phytoplankton biomass as evidenced by chlorophyll a levels in the upper water column. Fish abundances were only secondarily associated with salinity gradients as salinity was a factor that moderated primary production in the estuary. The persistence of spatial and temporal trends in the distribution of phytoplankton in the Neuse and Pamlico estuaries was reviewed. The review suggested that postmetamorphic juvenile menhaden modify their distribution patterns to match those created by phytoplankton biomass, which in turn makes them most abundant in the phytoplankton maxima of estuaries. Because the location of these maxima varies with the mixing and nutrient dynamics of different estuaries, so will the location of the nursery. C1 NATL MARINE FISHERIES SERV,BEAUFORT LAB,BEAUFORT,NC 28516. NR 51 TC 40 Z9 40 U1 0 U2 7 PU ESTUARINE RES FEDERATION PI LAWRENCE PA PO BOX 368, LAWRENCE, KS 66044 SN 0160-8347 J9 ESTUARIES JI Estuaries PD MAR PY 1996 VL 19 IS 1 BP 105 EP 114 DI 10.2307/1352656 PG 10 WC Environmental Sciences; Marine & Freshwater Biology SC Environmental Sciences & Ecology; Marine & Freshwater Biology GA TU217 UT WOS:A1996TU21700011 ER PT J AU Gallegos, CL Kenworthy, WJ AF Gallegos, CL Kenworthy, WJ TI Seagrass depth limits in the Indian River Lagoon (Florida, USA): Application of an optical water quality model SO ESTUARINE COASTAL AND SHELF SCIENCE LA English DT Article DE light attenuation; spectral attenuation; water quality; colour; seagrasses; depth limits; Halodule wrightii; Syringodium filiforme; USA coast ID SUBMERSED AQUATIC VEGETATION; SYRINGODIUM-FILIFORME; ABSORPTION; ATTENUATION; PHYTOPLANKTON; COEFFICIENTS; ESTUARY; SEA AB A model of spectral diffuse attenuation coefficient for downwelling irradiance in terms of the inherent optical properties of optically important water quality parameters was calibrated near two seagrass beds in the Indian River Lagoon, Florida, U.S.A. One of the seagrass sites was near the outflow of a canal discharging highly coloured water, and is regularly inundated by a plume of coloured water. Attenuation coefficients for photosynthetically active radiation predicted by the model agreed with observations within about 15%. Observed ecological compensation depth for the seagrass bed more distant from the colour source agreed well with the central tendency of the 20% penetration depth predicted by the optical model using the observed distributions of water quality parameters. Depth distributions of the seagrass bed near the coloured water source were about 0.5 m shallower, a result predicted by the optical model assuming the seagrass bed is inundated by the coloured water plume 50-70% of the time. At depths less than their ecological compensation depths, the two seagrass beds had similar species composition, shoot densities and biomass characteristics. Application of the model to hypothetical scenarios to reduce the impact of coloured water on the depth distribution of seagrasses near the discharge site indicated that any improvement in water quality would improve conditions for seagrass growth. The results indicate the utility of optical modelling in conjunction with limited field surveys of seagrasses for setting water quality objectives. (C) 1996 Academic Press Limited C1 NOAA,NATL MARINE FISHERIES SERV,SE FISHERIES CTR,BEAUFORT LAB,BEAUFORT,NC 28516. RP Gallegos, CL (reprint author), SMITHSONIAN ENVIRONM RES CTR,POB 28,EDGEWATER,MD 21037, USA. OI Gallegos, Charles/0000-0001-5112-0166 NR 28 TC 49 Z9 55 U1 4 U2 21 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 MAR PY 1996 VL 42 IS 3 BP 267 EP 288 DI 10.1006/ecss.1996.0020 PG 22 WC Marine & Freshwater Biology; Oceanography SC Marine & Freshwater Biology; Oceanography GA UA578 UT WOS:A1996UA57800001 ER PT J AU Kendall, AW Schumacher, JD Kim, S AF Kendall, AW Schumacher, JD Kim, S TI Walleye pollock recruitment in Shelikof Strait: Applied fisheries oceanography SO FISHERIES OCEANOGRAPHY LA English DT Article DE Alaska; fisheries oceanography; recruitment; Theragra chalcogramma; walleye pollock ID THERAGRA-CHALCOGRAMMA PALLAS; ALASKA COASTAL CURRENT; EARLY LIFE-HISTORY; WESTERN GULF; VERTICAL-DISTRIBUTION; OTOLITH ANALYSIS; LARVAL; JUVENILE; TRANSPORT; GROWTH AB Fisheries-Oceanography Coordinated Investigations (FOCI) is a National Oceanic and Atmospheric Administration (NOAA) research programme seeking to understand recruitment processes of commercially exploited Alaskan fishes. The FOCI is mainly comprised of scientists at the Pacific Marine Environmental Laboratory and the Alaska Fisheries Science Center who study both the biotic and abiotic environment, including processes within larval patches through integrated field, laboratory, and modelling studies. The initial focus of studies was walleye pollock (Theragra chalcogramma) spawning in Shelikof Strait, Gulf of Alaska. The choice of this population for our research was based on development of a large fishery and the substantial variation in recruitment that was observed in the late 1970s and early 1980s. Also, the early life history of this population is quite predictable and restricted both temporally and spatially. Walleye pollock spawn consistently in a small part of Shelikof Strait in early spring from which a large patch of eggs and later larvae is produced. In most years this concentration of larvae drifts to the south-west through the strait during April and May. Large numbers of larvae are often found in eddies which frequent the area and we have observed improved feeding conditions for larvae, in as opposed to out of eddies. We have found that first-feeding larvae have higher survival rates during: calm periods, rather than in storms, and that in many years recruitment is largely set by the end of the larval period, although in some years age-0 juvenile mortality is also important. FOCI now generates information that is being used for management of this resource. C1 NOAA,PACIFIC MARINE ENVIRONM LAB,SEATTLE,WA 98115. KOREA OCEAN RES & DEV INST,ANSAN,SEOUL 425600,SOUTH KOREA. RP Kendall, AW (reprint author), NOAA,ALASKA FISHERIES SCI CTR,7600 SAND POINT WAY NE,SEATTLE,WA 98115, USA. NR 90 TC 63 Z9 64 U1 0 U2 8 PU BLACKWELL SCIENCE LTD PI OXFORD PA OSNEY MEAD, OXFORD, OXON, ENGLAND OX2 0EL SN 1054-6006 J9 FISH OCEANOGR JI Fish Oceanogr. PD MAR PY 1996 VL 5 SU 1 BP 4 EP 18 DI 10.1111/j.1365-2419.1996.tb00079.x PG 15 WC Fisheries; Oceanography SC Fisheries; Oceanography GA TZ833 UT WOS:A1996TZ83300002 ER PT J AU Napp, JM Incze, LS Ortner, PB Siefert, DLW Britt, L AF Napp, JM Incze, LS Ortner, PB Siefert, DLW Britt, L TI The plankton of Shelikof Strait, Alaska: Standing stock, production, mesoscale variability and their relevance to larval fish survival SO FISHERIES OCEANOGRAPHY LA English DT Article DE fisheries oceanography; Gulf of Alaska; larval fish; plankton; spring bloom; survival; zoo-plankton ID POLLOCK THERAGRA-CHALCOGRAMMA; SMALL-SCALE TURBULENCE; WALLEYE POLLOCK; EGG-PRODUCTION; LIFE-HISTORY; WESTERN GULF; SPRING BLOOM; LABORATORY OBSERVATIONS; VERTICAL-DISTRIBUTION; POPULATION-DYNAMICS AB Physically-mediated variations in production, standing stock and distribution of plankton have a significant impact on the growth and survival of larval fishes in Shelikof Strait, We integrate descriptions of mechanisms that control the distribution and regional production of planktonic organisms with mechanisms that influence survival of early life history stages of marine fish, especially the locally abundant walleye pollock, Theragra chalcogramma. The timing of the spring phytoplankton bloom is more variable than the regular appearance of pollock larvae, and is affected by variability in the winter to spring storm season transition, stratification in the Alaska Coastal Current (ACC), and cloudiness. The spring bloom occurs first in the ACC, fuelling local production of copepod nauplii, the main prey item of early larval pollock. Shelikof Strait 2ooplankton standing stock is higher in the ACC than the surrounding Coastal Water (CW) throughout the spring. This is the result of local production as well as regional production which occurs upstream of the strait. Mesoscale features associated with the ACC (fronts, meanders, and eddies) determine the distribution of plankton through physical convergence, and reduced dispersion and transport. Evidence for enhancement of planktonic production in these features is lacking, Thus the ACC plays a strong role in determining plankton production, standing stock, and distribution in the Shelikof region. The strength of the relationship among plankton, planktonic production, larval pollock growth and survival, and fisheries recruitment is variable. The plankton is only one of several key variables that affect eventual recruitment to the pollock fishery. C1 BIGELOW LAB OCEAN SCI,W BOOTHBAY HARBOR,ME 04575. NOAA,ATLANTIC OCEANOG & METEOROL LAB,MIAMI,FL 33149. RP Napp, JM (reprint author), NOAA,ALASKA FISHERIES SCI CTR,7600 SAND POINT NE,SEATTLE,WA 98115, USA. NR 89 TC 55 Z9 56 U1 1 U2 6 PU BLACKWELL SCIENCE LTD PI OXFORD PA OSNEY MEAD, OXFORD, OXON, ENGLAND OX2 0EL SN 1054-6006 J9 FISH OCEANOGR JI Fish Oceanogr. PD MAR PY 1996 VL 5 SU 1 BP 19 EP 38 DI 10.1111/j.1365-2419.1996.tb00080.x PG 20 WC Fisheries; Oceanography SC Fisheries; Oceanography GA TZ833 UT WOS:A1996TZ83300003 ER PT J AU Hermann, AJ Hinckley, S Megrey, BA Stabeno, PJ AF Hermann, AJ Hinckley, S Megrey, BA Stabeno, PJ TI Interannual variability of the early life history of walleye pollock near Shelikof Strait as inferred from a spatially explicit, individual-based model SO FISHERIES OCEANOGRAPHY LA English DT Article DE Alaska; Alaska Coastal Current; Alaskan Stream; currents; individual-based model; interannual variability; walleye pollock; Theragra chalcogramma; Shelikof Strait ID THERAGRA-CHALCOGRAMMA; WESTERN GULF; ALASKA; CIRCULATION; TRANSPORT; LARVAL; MORTALITY AB A coupled biophysical model is used to hindcast the early life history of a population of walleye pollock (Theragra chalcogramma), to assess possible physical causes of interannual Variability in recruitment. The modelling approach combines a primitive equation, rigid-lid hydrodynamic model with a probabilistic, individual-based biological model of growth, development, and mortality. Individuals are tracked through space using daily velocity fields generated from the hydrodynamic model, along with self-directed vertical migrations appropriate to each life stage in the biological model. The hydrodynamic model is driven with wind and runoff time series appropriate to each year. Biological model output compares favourably with observed spatial distributions for specific years. Lloyd's index of patchiness, calculated from model output, was similar to values calculated from field data. Five noncontiguous years were chosen for hindcasts to span a wide range of meteorological conditions (winds, runoff) and recruitment success. Interannual comparisons suggest that two years of above average recruitment (1978 and 1988), and one year of below average recruitment (1991), experienced flow fields which carried many individuals into the Alaskan Stream. At the same time, the vigorous flow fields generated in each of these years carried some individuals onto the shelf area to the south-west of the spawning site. A year with low runoff and weak winds (1989) exhibited weak circulation, with extended retention of larvae near the spawning site. A year with high runoff (1987) was notable for the strength and frequency of mesoscale eddy activity. Eddies appear capable of both enhancing patchiness of early larvae (through retention) and dissipating patchiness of juveniles (through mesoscale mixing), Larvae retained in an eddy feature exhibit a narrower range of sizes than the population outside that feature. C1 NOAA,PACIFIC MARINE ENVIRONM LAB,SEATTLE,WA 98115. NOAA,ALASKA FISHERIES SCI CTR,SEATTLE,WA 98115. RP Hermann, AJ (reprint author), UNIV WASHINGTON,JOINT INST STUDY ATMOSPHERE & OCEANS,SEATTLE,WA 98195, USA. NR 37 TC 40 Z9 43 U1 0 U2 2 PU BLACKWELL SCIENCE LTD PI OXFORD PA OSNEY MEAD, OXFORD, OXON, ENGLAND OX2 0EL SN 1054-6006 J9 FISH OCEANOGR JI Fish Oceanogr. PD MAR PY 1996 VL 5 SU 1 BP 39 EP 57 DI 10.1111/j.1365-2419.1996.tb00081.x PG 19 WC Fisheries; Oceanography SC Fisheries; Oceanography GA TZ833 UT WOS:A1996TZ83300004 ER PT J AU Hermann, AJ Rugen, WC Stabeno, PJ Bond, NA AF Hermann, AJ Rugen, WC Stabeno, PJ Bond, NA TI Physical transport of young pollock larvae (Theragra chalcogramma) near Shelikof Strait: As inferred from a hydrodynamic model SO FISHERIES OCEANOGRAPHY LA English DT Article DE Alaska; Alaska Coastal Current; Alaskan Stream; currents; interannual variability; larvae; model; pollock; Shelikof Strait; Theragra chalcogramma ID WESTERN GULF; ALASKA; CIRCULATION; MORTALITY AB An advective model was used to simulate the drift of larval walleye pollock (Theragra chalcogramma) over a 40-day period (late April through early lune) near Shelikof Strait, Alaska. This model was used: (i) to assess how much of the observed change in larval positions during that period can be explained by transport at fixed depth; (ii) to demonstrate that observed change can he related to mean large-scale meteorological forcing; and (iii) to investigate accumulation of larvae in specific areas near the coast. Based on availability of larval and circulation data, three years were studied: 1988, 1989 and 1991. Velocity fields generated from a hydrodynamic model driven by winds and runoff were used to advect particles seeded in accordance with observed larval distributions in late April of each year. The modelled larvae were tracked at 40 m depth, corresponding to the mean depth of sampled larvae and the depth of neutrally buoyant drifters employed in field studies. Specific features observed in late May larval surveys were reproduced by the model, such as the accumulation of larvae in a shoal area downstream of the strait. Differences among the modelled years include extensive flushing of larvae to the south-west in 1988 and 1991, vs. limited flushing in 1989. These differences appear related to the mean large-scale atmospheric pressure patterns for April-May of those years. C1 UNIV WASHINGTON,JOINT INST STUDY ATMOSPHERE & OCEANS,SEATTLE,WA 98195. UNIV WASHINGTON,ALASKA FISHERIES SCI CTR,SEATTLE,WA 98195. RP Hermann, AJ (reprint author), NOAA,PACIFIC MARINE ENVIRONM LAB,NATL OCEAN & ATMOSPHER ADM,7600 SAND POINT WAY NE,SEATTLE,WA 98195, USA. NR 20 TC 25 Z9 25 U1 0 U2 2 PU BLACKWELL SCIENCE LTD PI OXFORD PA OSNEY MEAD, OXFORD, OXON, ENGLAND OX2 0EL SN 1054-6006 J9 FISH OCEANOGR JI Fish Oceanogr. PD MAR PY 1996 VL 5 SU 1 BP 58 EP 70 DI 10.1111/j.1365-2419.1996.tb00082.x PG 13 WC Fisheries; Oceanography SC Fisheries; Oceanography GA TZ833 UT WOS:A1996TZ83300005 ER PT J AU Brodeur, RD Napp, JM Wilson, MT Bograd, SJ Cokelet, ED Schumacher, JD AF Brodeur, RD Napp, JM Wilson, MT Bograd, SJ Cokelet, ED Schumacher, JD TI Acoustic detection of mesoscale biophysical features in the Shelikof sea valley, and their relevance to pollock larvae in the Gulf of Alaska SO FISHERIES OCEANOGRAPHY LA English DT Article DE acoustics; frontal zones; walleye pollock; zooplankton ID THERAGRA-CHALCOGRAMMA; WALLEYE POLLOCK; SCATTERING LAYERS; WESTERN GULF; STREAM; FISH; EDGE; PATCHINESS; ABUNDANCE; STRAIT AB Mesoscale features such as fronts and eddies can act to retain larval walleye pollock (Theragra chalcogramma) within the continental shelf zone in the western Gulf of Alaska. During two May cruises, we observed unusual patterns of backscattering with a 38 kHz acoustic system. Characteristics of this signal were a strong scattering layer at the surface and in midwater, with the water column between nearly void of sound scattering organisms. This signal appeared in several transects when satellite remote sensing indicated the presence of an eddy. Analysis of concomitant water properties and ADCP (153 kHz) data confirmed the existence of an anomalous physical feature at this location. Biological properties (chlorophyll and zooplankton) showed marked changes across the edge of the feature. Larval pollock densities were estimated to be an order of magnitude higher within this feature compared to those outside. Acoustic backscatter signals can be used to identify and characterize mesoscale biophysical features in the ocean, thereby enabling real-time studies of these features. C1 NOAA,PACIFIC MARINE ENVIRONM LAB,SEATTLE,WA 98115. RP Brodeur, RD (reprint author), NOAA,ALASKA FISHERIES SCI CTR,7600 SAND POINT WAY NE,SEATTLE,WA 98115, USA. NR 44 TC 5 Z9 5 U1 1 U2 4 PU BLACKWELL SCIENCE LTD PI OXFORD PA OSNEY MEAD, OXFORD, OXON, ENGLAND OX2 0EL SN 1054-6006 J9 FISH OCEANOGR JI Fish Oceanogr. PD MAR PY 1996 VL 5 SU 1 BP 71 EP 80 DI 10.1111/j.1365-2419.1996.tb00083.x PG 10 WC Fisheries; Oceanography SC Fisheries; Oceanography GA TZ833 UT WOS:A1996TZ83300006 ER PT J AU Stabeno, PJ Schumacher, JD Bailey, KM Brodeur, RD Cokelet, ED AF Stabeno, PJ Schumacher, JD Bailey, KM Brodeur, RD Cokelet, ED TI Observed patches of walleye pollock eggs and larvae in Shelikof Strait, Alaska: Their characteristics, formation and persistence SO FISHERIES OCEANOGRAPHY LA English DT Article DE eddies; ichthyoplankton; patchiness; schooling; walleye pollock ID THERAGRA-CHALCOGRAMMA; CONTINENTAL-SHELF; PLANKTONIC LARVAE; PRIBILOF ISLANDS; COASTAL CURRENT; WESTERN GULF; BERING SEA; TRANSPORT; ABUNDANCE; WINDS AB Using observations from 38 ichthyoplankton surveys conducted near Shelikof Strait, Alaska between 1979 and 1992, we characterized the horizontal distribution and spatial patchiness of the early life stages of walleye pollock (Theragra chalcogramma). Lloyd's index of patchiness ranged from 3.9-6.1 for eggs and 3.9-16.2 for larvae. This index was size (age) dependent: low for eggs, high for newly hatched larvae, then decreasing through late larval stage. By the early juvenile stage, patchiness increased as pollock began to school. The percentage of larvae in a patch (defined as the percentage of larvae present at stations where larval counts exceeded the mean by one standard deviation during the given survey) varied greatly (26-92%). Larval distributions were used to deduce physical mechanisms responsible for patches. Three categories of patches were identified: those created by interaction of larvae with time-dependent currents, those in the vicinity of Sutwik Island, and chose associated with eddies. Simulation experiments were utilized to examine processes influencing patch formation and the role of larval swimming. Between 5 and 6 weeks after hatching, larvae have swimming abilities that enable them to maintain a patch already created by physical mechanisms. C1 NOAA,ALASKA FISHERIES SCI CTR,SEATTLE,WA 98115. RP Stabeno, PJ (reprint author), NOAA,PACIFIC MARINE ENVIRONM LAB,7600 SAND POINT WAY NE,SEATTLE,WA 98115, USA. NR 53 TC 32 Z9 33 U1 0 U2 4 PU BLACKWELL SCIENCE LTD PI OXFORD PA OSNEY MEAD, OXFORD, OXON, ENGLAND OX2 0EL SN 1054-6006 J9 FISH OCEANOGR JI Fish Oceanogr. PD MAR PY 1996 VL 5 SU 1 BP 81 EP 91 DI 10.1111/j.1365-2419.1996.tb00084.x PG 11 WC Fisheries; Oceanography SC Fisheries; Oceanography GA TZ833 UT WOS:A1996TZ83300007 ER PT J AU Brodeur, RD Picquelle, SJ Blood, DM Merati, N AF Brodeur, RD Picquelle, SJ Blood, DM Merati, N TI Walleye pollock egg distribution and mortality in the western Gulf of Alaska SO FISHERIES OCEANOGRAPHY LA English DT Article DE cannibalism; egg stage; fertilization; mortality; predation; Theragra chalcogramma; vertical distribution ID EARLY-LIFE-HISTORY; THERAGRA-CHALCOGRAMMA; SHELIKOF STRAIT; MARINE FISH; LARVAE; SIZE AB We examine the distribution and mortality of walleye pollock (Theragra chalcogramma) eggs in the western Gulf of Alaska. Most pollock eggs were found in mid-water, with low proportions in the neustonic and epibenthic layers during all years of sampling. A silhouette camera towed through a high egg density region provided new information on small-scale spatial distributions and provided density estimates at two depth layers similar to those of depth-discrete net sampling. Annual egg production curves and natural mortalities were estimated for 1987-92 based on the abundance of several cohorts relative to their production rate, Production during 1989 and 1990 was lower than in the other four years but 1988 was the only year to show markedly different (higher) mortality than the rest. Fertilization rare was generally very high (>99%) but several collections early in the season contained a substantial fraction of unfertilized eggs. Invertebrate egg predation was mainly due to euphausiids and was variable among locations and years. Egg cannibalism by adult pollock on the spawning grounds was inconsequential (<1% for all years) compared to invertebrate predation. RP Brodeur, RD (reprint author), NOAA,ALASKA FISHERIES SCI CTR,7600 SAND POINT WAY NE,SEATTLE,WA 98115, USA. NR 48 TC 19 Z9 19 U1 0 U2 5 PU BLACKWELL SCIENCE LTD PI OXFORD PA OSNEY MEAD, OXFORD, OXON, ENGLAND OX2 0EL SN 1054-6006 J9 FISH OCEANOGR JI Fish Oceanogr. PD MAR PY 1996 VL 5 SU 1 BP 92 EP 111 DI 10.1111/j.1365-2419.1996.tb00085.x PG 20 WC Fisheries; Oceanography SC Fisheries; Oceanography GA TZ833 UT WOS:A1996TZ83300008 ER PT J AU Theilacker, GH Bailey, KM Canino, MF Porter, SM AF Theilacker, GH Bailey, KM Canino, MF Porter, SM TI Variations in larval walleye pollock feeding and condition: A synthesis SO FISHERIES OCEANOGRAPHY LA English DT Article DE Alaska; condition; feeding; larval fish; survival; walleye pollock ID HADDOCK MELANOGRAMMUS-AEGLEFINUS; COD GADUS-MORHUA; RNA DNA RATIOS; NORTHERN ANCHOVY; ENGRAULIS-MORDAX; THERAGRA-CHALCOGRAMMA; CONTRASTING ENVIRONMENTS; TRACHURUS-SYMMETRICUS; NUTRITIONAL CONDITION; SHELIKOF STRAIT AB There was a strong association among concentrations of microzooplankton prey sampled from the walleye pollock, Theragra chalcogramma, larval habitat, gut contents of larvae, and their nutritional condition. Subsequently, hypothesized survival potentials linked to food availability were validated by independently determined mortality rates. We present evidence that a significant number of walleye pollock Larvae were starving in 1991 but that fewer were starving in 1992, At some stations where prey levels were anomalously low in 1991, up to 40% of the larvae were in poor condition. There appears to be a 2-week period after first feeding when walleye pollock are vulnerable to starvation. RP Theilacker, GH (reprint author), NOAA,ALASKA FISHERIES SCI CTR,7600 SAND POINT WAY NE,SEATTLE,WA 98115, USA. NR 66 TC 65 Z9 67 U1 1 U2 10 PU BLACKWELL SCIENCE LTD PI OXFORD PA OSNEY MEAD, OXFORD, OXON, ENGLAND OX2 0EL SN 1054-6006 J9 FISH OCEANOGR JI Fish Oceanogr. PD MAR PY 1996 VL 5 SU 1 BP 112 EP 123 DI 10.1111/j.1365-2419.1996.tb00086.x PG 12 WC Fisheries; Oceanography SC Fisheries; Oceanography GA TZ833 UT WOS:A1996TZ83300009 ER PT J AU Bailey, KM Picquelle, SJ Spring, SM AF Bailey, KM Picquelle, SJ Spring, SM TI Mortality of larval walleye pollock Theragra chalcogramma in the western Gulf of Alaska, 1988-91 SO FISHERIES OCEANOGRAPHY LA English DT Article DE larval mortality; Theragra chalcogramma; walleye pollock; wind mixing ID NORTHERN ANCHOVY; ENGRAULIS-MORDAX; SHELIKOF STRAIT; GROWTH; SURVIVAL; AGE; ADVECTION; DISPERSAL; JUVENILE; PALLAS AB Mortality rates of larval walleye pollock Theragra chalcogramma were estimated from larval survey data from 1988 to 1991. Mortality estimates were based on cohort-specific losses between occupations of survey grids. Interannually, estimates of early feeding stage larval mortality rates ranged over an order of magnitude, from 0.045-0.43 day(-1), and declined sharply with age. There is some evidence that mortality rates of early feeding larvae tend to be negatively correlated with temperature and postively correlated with wind mixing. RP Bailey, KM (reprint author), NOAA,ALASKA FISHERIES SCI CTR,7600 SAND POINT WAY NE,SEATTLE,WA, USA. NR 36 TC 27 Z9 28 U1 0 U2 5 PU BLACKWELL SCIENCE LTD PI OXFORD PA OSNEY MEAD, OXFORD, OXON, ENGLAND OX2 0EL SN 1054-6006 J9 FISH OCEANOGR JI Fish Oceanogr. PD MAR PY 1996 VL 5 SU 1 BP 124 EP 136 DI 10.1111/j.1365-2419.1996.tb00087.x PG 13 WC Fisheries; Oceanography SC Fisheries; Oceanography GA TZ833 UT WOS:A1996TZ83300010 ER PT J AU Bailey, KM Brown, AL Yoklavich, MM Mier, KL AF Bailey, KM Brown, AL Yoklavich, MM Mier, KL TI Interannual variability in growth of larval and juvenile walleye pollock Theragra chalcogramma in the western Gulf of Alaska, 1983-91 SO FISHERIES OCEANOGRAPHY LA English DT Article DE Alaska; growth; larvae; length-at-age; walleye pollock ID OTOLITH ANALYSIS; PALLAS AB Interannual variability in growth of larval walleye pollock Theragra chalcogramma was examined from 1983 to 1991 and of juveniles from 1985 to 1990. ANCOVA was used to assess differences in population growth rates, and an alternate method was developed to examine variations between annual length-at-age data and average 'expected' values over different age groupings. For larvae, the years 1986, 1981, 1989 and 1990 had higher than average length-at-age, and 1988 and 1991 had lower than average values. Relationships between growth and SST and larval density were not clear. A tentative relationship between copepod nauplii abundance and larval length-at-age was noted. The consequence of larval growth to larval mortality, late larval abundance or recruitment was not clear. We conclude that larval mortality rates are highly variable and tend to mask effects of moderate variability in growth on later abundance. For juveniles, 1987 had significantly lower than average length-at-age and 1988 had higher than average values. Although there are few years of data, they tend to support the importance of juvenile growth in the recruitment process. Conditions for the large 1988 year class are documented and discussed, including warm SST, calm winds, relatively low larval growth rates, low abundances of potential predators on larvae, low larval mortality rates, and high juvenile growth rates. C1 NOAA,PACIFIC FISHERIES ENVIRONM GRP,SW FISHERIES SCI CTR,PACIFIC GROVE,CA 93950. RP Bailey, KM (reprint author), NOAA,ALASKA FISHERIES SCI CTR,7600 SAND POINT WAY NE,SEATTLE,WA, USA. NR 33 TC 37 Z9 38 U1 1 U2 3 PU BLACKWELL SCIENCE LTD PI OXFORD PA OSNEY MEAD, OXFORD, OXON, ENGLAND OX2 0EL SN 1054-6006 J9 FISH OCEANOGR JI Fish Oceanogr. PD MAR PY 1996 VL 5 SU 1 BP 137 EP 147 DI 10.1111/j.1365-2419.1996.tb00088.x PG 11 WC Fisheries; Oceanography SC Fisheries; Oceanography GA TZ833 UT WOS:A1996TZ83300011 ER PT J AU Brodeur, RD Wilson, MT AF Brodeur, RD Wilson, MT TI A review of the distribution, ecology and population dynamics of age-0 walleye pollock in the Gulf of Alaska SO FISHERIES OCEANOGRAPHY LA English DT Review DE age-0 juveniles; distribution; feeding; growth; population dynamics; predators; Theragra chalcogramma; walleye pollock ID EASTERN BERING SEA; THERAGRA-CHALCOGRAMMA PALLAS; EARLY LIFE STAGES; VERTICAL-DISTRIBUTION; WESTERN GULF; OTOLITH ANALYSIS; CLASS STRENGTH; JUVENILE; ABUNDANCE; SURVIVAL AB This review paper synthesizes published research and unpublished data on the abundance and distribution patterns, ecology and population dynamics of walleye pollock (Theragra chalcogramma) during their first year of Life (age-0) in the Gulf of Alaska. Distribution patterns have been described using mainly trawl catches, but recently, acoustic methodology has been employed, especially in examining vertical distributions. Although age-0 pollock are found throughout the Gulf, the highest catches occurred west of Kodiak Island. Pollock are pelagic for at Least their first 6 months of life but show an ontogenetic increase in depth distribution superimposed on a pronounced diel vertical migration at a larger size. Daily growth rates are variable depending on year, season and area, and growth generally ceases during the winter. The diet of age-0 pollock shifts from mainly copepods in early juveniles to euphausiids by fail, with epibenthic organisms becoming important during the winter months. Feeding occurs mainly at night in surface waters. Age-0 pollock are most frequently associated with gelatinous zooplankton (medusae) and older pollock. Many predators on age-0 pollock have been identified; the most important are arrowtooth flounder (Atheresthes stomias), adult pollock, puffins (Fratercula spp.), murres (Uria spp.), harbor seals (Phoca vitulina richardsi) and Steller sea lions (Eumetopias jubatus). Modelling provides some insight into the population dynamics of these juveniles and environmental conditions which interannually affect their survival. These results are discussed relative to the importance of age-0 pollock in the recruitment of this species and to their role in the pelagic ecosystem. RP Brodeur, RD (reprint author), NOAA,ALASKA FISHERIES SCI CTR,7600 SAND POINT WAY NE,SEATTLE,WA 98115, USA. NR 96 TC 68 Z9 68 U1 0 U2 11 PU BLACKWELL SCIENCE LTD PI OXFORD PA OSNEY MEAD, OXFORD, OXON, ENGLAND OX2 0EL SN 1054-6006 J9 FISH OCEANOGR JI Fish Oceanogr. PD MAR PY 1996 VL 5 SU 1 BP 148 EP 166 DI 10.1111/j.1365-2419.1996.tb00089.x PG 19 WC Fisheries; Oceanography SC Fisheries; Oceanography GA TZ833 UT WOS:A1996TZ83300012 ER PT J AU Olla, BL Davis, MW Ryer, CH Sogard, SM AF Olla, BL Davis, MW Ryer, CH Sogard, SM TI Behavioural determinants of distribution and survival in early stages of walleye pollock, Theragra chalcogramma: A synthesis of experimental studies SO FISHERIES OCEANOGRAPHY LA English DT Article DE behaviour; feeding; fish eggs; juvenile fish; larval fish; ontogeny; predation; recruitment; schooling; vertical distribution; yolksac larvae ID EASTERN BERING SEA; ANCHOVY ENGRAULIS-MORDAX; PLANKTON CONTACT RATES; SMALL-SCALE TURBULENCE; VERTICAL-DISTRIBUTION; CLUPEA-HARENGUS; PREDATOR PRESENCE; ATLANTIC HALIBUT; FEEDING BEHAVIOR; FISH PREDATORS AB This review summarizes results of an extensive series of laboratory studies on the behavioural responses of early life stages of walleye pollock, Theragra chalcogramma to key environmental factors including light, temperature, gravity, turbulence, food availability and predator presence. Experiments focused on vertical distribution of egg through 0-age stages, and social interactions of age-0 juveniles. Key factors were modified either singly or in concert to determine their direct and indirect influence on fish behaviour. The observed results suggest that the behaviour of individual fish depends on the integration of a continually changing hierarchy of both intrinsic and extrinsic factors, with the relative importance of a specific factor varying with ontogeny and over time and space. The broad range of responses displayed by early life stages suggests that behaviour plays an important role in determining the consequences of environmental variability on walleye pollock populations. In general, results from our laboratory experiments are consistent with patterns observed in field studies, supporting the efficacy of using experimental behavioural research to define some of the underlying mechanisms controlling distribution and survival in the field, and eventual recruitment to adult populations. RP Olla, BL (reprint author), NOAA,ALASKA FISHERIES SCI CTR,HATFIELD MARINE SCI CTR,NEWPORT,OR 97365, USA. NR 80 TC 43 Z9 44 U1 0 U2 3 PU BLACKWELL SCIENCE LTD PI OXFORD PA OSNEY MEAD, OXFORD, OXON, ENGLAND OX2 0EL SN 1054-6006 J9 FISH OCEANOGR JI Fish Oceanogr. PD MAR PY 1996 VL 5 SU 1 BP 167 EP 178 DI 10.1111/j.1365-2419.1996.tb00090.x PG 12 WC Fisheries; Oceanography SC Fisheries; Oceanography GA TZ833 UT WOS:A1996TZ83300013 ER PT J AU Bailey, KM Brodeur, RD Hollowed, AB AF Bailey, KM Brodeur, RD Hollowed, AB TI Cohort survival patterns of walleye pollock, Theragra chalcogramma, in Shelikof Strait, Alaska: A critical factor analysis SO FISHERIES OCEANOGRAPHY LA English DT Article DE cohort survival; Gulf of Alaska; key factor analysis; walleye pollock ID PLAICE PLEURONECTES-PLATESSA; WESTERN GULF; LARVAL; RECRUITMENT; JUVENILE; POPULATION; FISH; VARIABILITY; SETTLEMENT; ABUNDANCE AB A series of age-specific life tables for walleye pollock (Theragra chalcogramma) in the western Gulf of Alaska was compiled for the 1980-91 year classes. The life tables were utilized to perform an exploratory key factor analysis to examine the timing of critical periods in the recruitment process, evidence of density-dependence at different stages and trends in mortality rates. Early larval mortality was significantly correlated with generational mortality (In recruits/spawning biomass), but patterns in juvenile mortality also were similar to generational mortality and in some years were clearly dominant in determining the fate of a cohort. Density-dependent mortality, based on the correlation between mortality and initial abundance, was indicated only for the late larval to early juvenile stage. Time trends were marginally significant for juvenile mortality. It is speculated that the observed increase in juvenile mortality is associated with increasing abundance of arrowtooth flounder. Weaknesses in the data base are discussed; these along with the short time series involved make our conclusions tentative and subject to further study. We hypothesize that pollock recruitment levels can be established at any life stage depending on sufficient supply from prior stages, a type of dynamics which can be termed supply dependent multiple life stage control. RP Bailey, KM (reprint author), NOAA,ALASKA FISHERIES SCI CTR,7600 SAND POINT WAY NE,SEATTLE,WA 98115, USA. NR 37 TC 49 Z9 50 U1 1 U2 5 PU BLACKWELL SCIENCE LTD PI OXFORD PA OSNEY MEAD, OXFORD, OXON, ENGLAND OX2 0EL SN 1054-6006 J9 FISH OCEANOGR JI Fish Oceanogr. PD MAR PY 1996 VL 5 SU 1 BP 179 EP 188 DI 10.1111/j.1365-2419.1996.tb00091.x PG 10 WC Fisheries; Oceanography SC Fisheries; Oceanography GA TZ833 UT WOS:A1996TZ83300014 ER PT J AU Megrey, BA Hollowed, AB Hare, SR Macklin, SA Stabeno, PJ AF Megrey, BA Hollowed, AB Hare, SR Macklin, SA Stabeno, PJ TI Contributions of FOCI research to forecasts of year-class strength of walleye pollock in Shelikof Strait, Alaska SO FISHERIES OCEANOGRAPHY LA English DT Article DE forecast; recruitment; stock assessment; walleye pollock; year-class strength ID THERAGRA-CHALCOGRAMMA; MERLUCCIUS-PRODUCTUS; NORTHEAST PACIFIC; LARVAL TRANSPORT; WESTERN GULF; RECRUITMENT; FISHERIES; DISTRIBUTIONS; CALIFORNIA; ABUNDANCE AB NOAA's Fisheries Oceanography Coordinated Investigations (FOCI) contributes information to help forecast year-class strength of walleye pollock (Theragra chalcogramma) in the Gulf of Alaska. Quantitative estimates of recruitment are obtained from models of stock assessment and stock projection employing information supplied by FOCI. To generate its information, FOCI convenes specialists in marine biology, physical and fisheries oceanography, meteorology, and statistics to assemble and analyse relevant biological and physical time series with respect to recruitment and processes hypothesized to influence fish survival. Statistical methods encompass linear and nonlinear regression, stochastic simulation modelling, transfer function time series modelling, and tree-modelling, regression. The current database consists of 31 years of data, and analyses have identified factors that affect ocean stratification and circulation during spring and summer of the fish's birth year as being important to recruitment. A conceptual model of the recruitment process serves as the framework for a recruitment forecast scheme. A stochastic mathematical simulation model of the conceptual model produces similarities between simulated and observed recruitment time series. FOCI has successfully forecast recruitment observed over the past several years. C1 UNIV WASHINGTON,SCH FISHERIES,SEATTLE,WA 98195. NOAA,PACIFIC MARINE ENVIRONM LAB,SEATTLE,WA 98115. RP Megrey, BA (reprint author), NOAA,ALASKA FISHERIES SCI CTR,SEATTLE,WA 98115, USA. NR 84 TC 39 Z9 40 U1 0 U2 5 PU BLACKWELL SCIENCE LTD PI OXFORD PA OSNEY MEAD, OXFORD, OXON, ENGLAND OX2 0EL SN 1054-6006 J9 FISH OCEANOGR JI Fish Oceanogr. PD MAR PY 1996 VL 5 SU 1 BP 189 EP 203 DI 10.1111/j.1365-2419.1996.tb00092.x PG 15 WC Fisheries; Oceanography SC Fisheries; Oceanography GA TZ833 UT WOS:A1996TZ83300015 ER PT J AU Larsen, JC Mackie, RL Manzella, A Fiordelisi, A Rieven, S AF Larsen, JC Mackie, RL Manzella, A Fiordelisi, A Rieven, S TI Robust smooth magnetotelluric transfer functions SO GEOPHYSICAL JOURNAL INTERNATIONAL LA English DT Article DE electromagnetic methods AB Robust estimates of the magnetotelluric (MT) transfer function are found using an iterative reweighted method on time series data corrected for outliers and gaps. The MT transfer function, composed of several analytic functions smoothly varying in frequency, is used to represent the frequency-domain relationship between electric and magnetic time series. The smoothly varying transfer function facilitates identification and removal of electric and magnetic outliers (spikes), construction of the frequency-and time-domain weights used for obtaining robust smooth and band-averaged estimates, and separation of the time series into MT and correlated noise signals if a remote site exists that is free of the correlated noise. Errors in the transfer function are calculated using jackknife estimates of the solution covariance. The method is tested on: time series from a relatively clean MT site in central California; a test time series based on Tucson magnetic time series plus synthetic noise for a given transfer function; and time series from the Larderello geothermal region in central Italy where there are strong signals from d.c. electrified railways. C1 MIT, CAMBRIDGE, MA 02142 USA. CNR, INT INST GEOTHERMAL RES, I-56126 PISA, ITALY. ENEL, ESPLORAZ MINERARIA, I-56122 PISA, ITALY. RP NOAA, PACIFIC MARINE ENVIRONM LAB, 7600 SAND POINT WAY NE, SEATTLE, WA 98115 USA. OI MANZELLA, ADELE/0000-0002-2367-0969 NR 22 TC 89 Z9 101 U1 2 U2 11 PU OXFORD UNIV PRESS PI OXFORD PA GREAT CLARENDON ST, OXFORD OX2 6DP, ENGLAND SN 0956-540X EI 1365-246X J9 GEOPHYS J INT JI Geophys. J. Int. PD MAR PY 1996 VL 124 IS 3 BP 801 EP 819 DI 10.1111/j.1365-246X.1996.tb05639.x PG 19 WC Geochemistry & Geophysics SC Geochemistry & Geophysics GA TY267 UT WOS:A1996TY26700010 ER PT J AU Bender, M Ellis, T Tans, P Francey, R Lowe, D AF Bender, M Ellis, T Tans, P Francey, R Lowe, D TI Variability in the O-2/N-2 ratio of southern hemisphere air, 1991-1994: Implications for the carbon cycle SO GLOBAL BIOGEOCHEMICAL CYCLES LA English DT Article ID ATMOSPHERIC OXYGEN; SURFACE WATERS; OCEAN; PACIFIC; CIRCULATION; MODEL; DISTRIBUTIONS; PRODUCTIVITY; TRACER AB We present a record of variations in the O-2/N-2 ratio of air at 41 degrees S latitude from 1991-1994 based on the mass spectrometric analysis of flask samples from Cape Grim, Tasmania, and Baring Head, New Zealand. Results for Cape Grim for the period from June 1991 to February 1992 are in good agreement with previously published data of Keeling and Shertz [1992]. Plotted versus time, O-2/N-2 ratios show the expected annual cycles. O-2/N-2 increases in austral spring and summer (caused mainly by net oceanic production) and decreases in fall and winter (caused by ventilation of the seasonal and main thermoclines). The average amplitude of the seasonal cycle implies net oceanic production of about 5 mol C m(-2) yr(-1) with considerable interannual variability. The O-2/N-2 ratio of air decreased at the rate of 12 +/- 4 per meg/yr (0.012 parts per thousand/yr) between winter 1991 and winter 1993. This value is considerably less than the O-2 consumption rate associated with fossil fuel burning (about 20 per meg/yr), suggesting that the land biosphere was an O-2 source and an important CO2 sink during this period. Alternatively, the oceans may have been a transient O-2 sink during 1991-1993, most likely caused by an enhanced rate of thermocline ventilation with respect to the steady-state value. C1 CSIRO,DIV ATMOSPHER RES,ASPENDALE,VIC 3195,AUSTRALIA. NATL INST WATER & ATMOSPHER RES LTD,ATMOSPHER DIV,LOWER HUTT,NEW ZEALAND. NOAA,CLIMATE MONITORING & DIAGNOST LAB,BOULDER,CO 80303. UNIV RHODE ISL,GRAD SCH OCEANOG,NARRAGANSETT,RI 02882. NR 26 TC 91 Z9 91 U1 2 U2 6 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 MAR PY 1996 VL 10 IS 1 BP 9 EP 21 DI 10.1029/95GB03295 PG 13 WC Environmental Sciences; Geosciences, Multidisciplinary; Meteorology & Atmospheric Sciences SC Environmental Sciences & Ecology; Geology; Meteorology & Atmospheric Sciences GA TY595 UT WOS:A1996TY59500002 ER PT J AU Fiske, S Chambers, E AF Fiske, S Chambers, E TI The inventions of practice SO HUMAN ORGANIZATION LA English DT Article; Proceedings Paper CT 13th International Congress of Anthropological and Ethnological Sciences - The Cultural and Biological Dimensions of Global Change CY JUL 29-AUG 05, 1993 CL MEXICO CITY, MEXICO SP UNESCO, Int Union Anthr & Ethnol Sci DE practicing anthropology; professionalization; professional organizations; employment; training; ethics; US ID APPLIED ANTHROPOLOGY; PRAXIS; POLICY AB The integration of applied and practicing anthropology into the professional mainstream has never been as apparent as in recent years. As this integration has proceeded, little attention has been paid to the variety of interpretations offered to describe current modes of anthropological practice. The authors suggest that the idea of practice is still in the process of being invented and devote their attention to discussing differences in some of the major ways in which applied and practicing anthropology has recently been represented. The article focuses on three components of practicing anthropology, beginning with a discussion of the institutionalization of practice in the last decade. The authors then examine the extent to which recent reports on the employment of practicing anthropologists might help us identify different models of practice. The article concludes with a discussion of a variety of issues related to practice, each of which has yielded different models and interpretations. C1 NOAA,US DEPT COMMERCE,NATL SEA GRANT COLL PROGRAM,WASHINGTON,DC 20230. RP Fiske, S (reprint author), UNIV MARYLAND,COLLEGE PK,MD 20742, USA. NR 74 TC 2 Z9 2 U1 0 U2 3 PU SOC APPLIED ANTHROPOLOGY PI OKLAHOMA CITY PA BUSINESS OFFICE BOX 24083, OKLAHOMA CITY, OK 73124 SN 0018-7259 J9 HUM ORGAN JI Hum. Organ. PD SPR PY 1996 VL 55 IS 1 BP 1 EP 12 PG 12 WC Anthropology; Social Sciences, Interdisciplinary SC Anthropology; Social Sciences - Other Topics GA UE300 UT WOS:A1996UE30000001 ER PT J AU Beichl, I Sullivan, F AF Beichl, I Sullivan, F TI Tree-lookup for partial sums or: How can I find this stuff quickly? SO IEEE COMPUTATIONAL SCIENCE & ENGINEERING LA English DT Editorial Material C1 IDA COMP SCI,BOWIE,MD. RP Beichl, I (reprint author), US NATL INST STAND & TECHNOL,COMP & APPL MATH LAB,GAITHERSBURG,MD, USA. NR 0 TC 2 Z9 2 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 SPR PY 1996 VL 3 IS 1 BP 13 EP 15 DI 10.1109/99.486756 PG 3 WC Computer Science, Theory & Methods; Engineering, Electrical & Electronic; Mathematics, Applied SC Computer Science; Engineering; Mathematics GA UA403 UT WOS:A1996UA40300005 ER PT J AU Xu, LH Lees, RM Vasconcellos, ECC Zerbetto, SC Zink, LR Evenson, KM AF Xu, LH Lees, RM Vasconcellos, ECC Zerbetto, SC Zink, LR Evenson, KM TI Methanol and the optically pumped far-infrared laser SO IEEE JOURNAL OF QUANTUM ELECTRONICS LA English DT Article ID CH3OH; SPECTRUM; ASSIGNMENTS; LINES; CM-1 AB New results on the generation and spectroscopic analysis of optically pumped Par-infrared (FIR) laser emission from CH3OH have been obtained as part of a systematic study of methanol isotopomers as FIR laser sources utilizing the extended line coverage available from a recently developed high-resolution CO2 laser of high efficiency. For normal CH3OH, six new short-wavelength lines have been found using a 2 m long Fabry-Perot FIR laser cavity, Accurate heterodyne frequency measurements are reported for 14 CH3OH FIR laser lines, nearly all above 100 cm(-1), as well as accurate frequency offsets for most of the corresponding CO2 pump lines. Spectroscopic assignments are presented for nine high-frequency FIR laser lines in four pump systems. C1 UNIV NEW BRUNSWICK,DEPT PHYS,FREDERICTON,NB E3B 5A3,CANADA. UNIV CAMPINAS,INST FIS GLEB WATAGHIN,DEPT ELETRON QUANT,BR-13083970 CAMPINAS,SP,BRAZIL. NATL INST STAND & TECHNOL,DIV TIME & FREQUENCY,BOULDER,CO 80303. RP Xu, LH (reprint author), UNIV NEW BRUNSWICK,DEPT PHYS SCI,ST JOHN,NB E2L 4L5,CANADA. RI Xu, Li-Hong/J-5095-2015; Inst. of Physics, Gleb Wataghin/A-9780-2017 NR 23 TC 38 Z9 40 U1 1 U2 5 PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017-2394 SN 0018-9197 J9 IEEE J QUANTUM ELECT JI IEEE J. Quantum Electron. PD MAR PY 1996 VL 32 IS 3 BP 392 EP 399 DI 10.1109/3.485389 PG 8 WC Engineering, Electrical & Electronic; Optics; Physics, Applied SC Engineering; Optics; Physics GA UB295 UT WOS:A1996UB29500006 ER PT J AU Oti, JO Russek, SE Sanders, SC Cross, RW AF Oti, JO Russek, SE Sanders, SC Cross, RW TI Models of granular giant magnetoresistance multilayer thin films SO IEEE TRANSACTIONS ON MAGNETICS LA English DT Article AB Phenomenological micromagnetic and large-scale magnetization-dependent models of resistivity that produce giant magnetoresistance in granular multilayer magnetic thin films are described. Included in the models are intralayer and interlayer scattering components formulated explicitly in terms of the microstructural properties and characteristic transport lengths of the medium. The micromagnetic model provides insight into the influence of the magnetization distribution on the giant magnetoresistance response of the medium. The large-scale model which is derived from the micromagnetic model, is useful for obtaining media transport parameters from experimental data. Both models are used to study a set of annealed NiFe/Ag multilayer films. RP Oti, JO (reprint author), NATL INST STAND & TECHNOL,DIV ELECTROMAGNET TECHNOL,BOULDER,CO 80303, USA. NR 15 TC 5 Z9 5 U1 0 U2 0 PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017-2394 SN 0018-9464 J9 IEEE T MAGN JI IEEE Trans. Magn. PD MAR PY 1996 VL 32 IS 2 BP 590 EP 598 DI 10.1109/20.486551 PG 9 WC Engineering, Electrical & Electronic; Physics, Applied SC Engineering; Physics GA TY871 UT WOS:A1996TY87100043 ER PT J AU Vadus, JR AF Vadus, JR TI Electronic nautical charting: Economic value and role in sustainable development of marine transport operations SO INTERNATIONAL HYDROGRAPHIC REVIEW LA English DT Article AB Electronic nautical charting plays a major role in providing safe and efficient navigation of vessels primarily involved in commerce, fishery landings, marine recreation, cruises and research activities on the civil side, and naval operations for the military. In order to determine the contributions of electronic charting to marine transport operations, and the priorities for converting to electronic charts, this paper provides a general assessment of the economic value and importance of shipping operations in and out of U.S. ports including: foreign commerce, fishery landings, accidents, oil spills and military needs. This assessment will enable establishing priorities for electronic charts based on importance in serving U.S. Ports and U.S. Coast Guard Districts. Many accidents and spills are due to human error in ship navigation. In many cases these could be averted by using Electronic Nautical Charts (ENC) integrated with other navigation aids to provide features for collision/grounding avoidance. In its supporting role, ENC will help promote sustainable development of marine transport operations. In addition, ENC provides geodetically accurate coastal mapping data to serve as a reference base for Geographic Information Systems (GIS). RP Vadus, JR (reprint author), NOAA,NATL OCEAN SERV,COAST SURVEY,1315 E W HIGHWAY,SILVER SPRING,MD 20910, USA. NR 12 TC 1 Z9 1 U1 2 U2 4 PU INT HYDROGRAPHIC BUREAU PI MONTE CARLO PA AVE PRES J F KENNEDY, MONTE CARLO, MONACO SN 0020-6946 J9 INT HYDROGR REV JI Int. Hydrogr. Rev. PD MAR PY 1996 VL 73 IS 1 BP 31 EP 42 PG 12 WC Engineering, Marine; Oceanography; Water Resources SC Engineering; Oceanography; Water Resources GA UP460 UT WOS:A1996UP46000004 ER PT J AU Huie, RE Clifton, CL AF Huie, RE Clifton, CL TI Kinetics of the reaction of the sulfate radical with the oxalate anion SO INTERNATIONAL JOURNAL OF CHEMICAL KINETICS LA English DT Article ID AQUEOUS-SOLUTION; RATE CONSTANTS; ELECTRON-TRANSFER; EXCITED-STATE; OXIDATION; WATER; IONS; COMPLEXES; SO4 AB The kinetics of the reaction of the sulfate radical, SO4-, with the oxalate anion, C2O42- was studied in aqueous solution and second-order rate constants, corrected For the effects of ionic strength, derived. Measurements were carried out over the temperature range 24-60 degrees C resulting in the expression k(0) = 2.10 +/- 0.96 x 10(8) exp(-1080 +/- 140/T) L mol(-1) s(-1). (C) 1996 John Wiley & Sons, Inc. RP Huie, RE (reprint author), NATL INST STAND & TECHNOL,DIV CHEM KINET & THERMODYNAM,GAITHERSBURG,MD 20899, USA. RI Huie, Robert/A-5645-2010 NR 31 TC 5 Z9 5 U1 0 U2 3 PU JOHN WILEY & SONS INC PI NEW YORK PA 605 THIRD AVE, NEW YORK, NY 10158-0012 SN 0538-8066 J9 INT J CHEM KINET JI Int. J. Chem. Kinet. PD MAR PY 1996 VL 28 IS 3 BP 195 EP 199 PG 5 WC Chemistry, Physical SC Chemistry GA TW133 UT WOS:A1996TW13300005 ER PT J AU Abramson, B Brown, J Edwards, W Murphy, A Winkler, RL AF Abramson, B Brown, J Edwards, W Murphy, A Winkler, RL TI Hailfinder: A Bayesian system for forecasting severe weather SO INTERNATIONAL JOURNAL OF FORECASTING LA English DT Article DE Bayesian; belief networks; meteorology; system design; weather forecasting; intelligent systems; elicitation ID BELIEF NETWORKS; EXPERT SYSTEMS; VERIFICATION AB Hailfinder is a Bayesian system that combines meteorological data and models with expert judgment, based on both experience and physical understanding, to forecast severe weather in Northeastern Colorado. The system is based on a model, known as a belief network (BN), that has recently emerged as the basis of some powerful intelligent systems. Hailfinder is the first such system to apply these Bayesian models in the realm of meteorology, a field that has served as the basis of many past investigations of probabilistic forecasting. The design of Hailfinder provides a variety of insights to designers of other BN-based systems, regardless of their fields of application. C1 CARNEGIE MELLON UNIV,DEPT ENGN & PUBL POLICY,PITTSBURGH,PA 15213. NOAA,FORECAST SYST LAB,BOULDER,CO 80303. WISE DECIS INC,STUDIO CITY,CA 91604. UNIV SO CALIF,SOCIAL SCI RES INST,LOS ANGELES,CA. PREDICT & EVALUAT SYST,CORVALLIS,OR 97330. DUKE UNIV,FUQUA SCH BUSINESS,DURHAM,NC 27708. RP Abramson, B (reprint author), CAMBRIDGE RES ASSOCIATES,1430 SPRING HILL RD,SUITE 200,MCLEAN,VA 22102, USA. RI Brown, John/D-3361-2015 NR 20 TC 83 Z9 85 U1 1 U2 7 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0169-2070 J9 INT J FORECASTING JI Int. J. Forecast. PD MAR PY 1996 VL 12 IS 1 BP 57 EP 71 DI 10.1016/0169-2070(95)00664-8 PG 15 WC Economics; Management SC Business & Economics GA UQ697 UT WOS:A1996UQ69700005 ER PT J AU Coakley, KJ AF Coakley, KJ TI Bootstrap method for nonlinear filtering of EM-ML reconstructions of PET images SO INTERNATIONAL JOURNAL OF IMAGING SYSTEMS AND TECHNOLOGY LA English DT Article ID POSITRON EMISSION TOMOGRAPHY; LIKELIHOOD ESTIMATOR IMAGES; MAXIMUM-LIKELIHOOD; FDG PET; ALGORITHM AB Reconstructions of positron emission tomography images are obtained with the iterative expectation maximization (EM) algorithm. The EM algorithm is halted according to a cross-validation procedure. For the cases studied, this method yields a reconstruction with high variability about its expected value. The variability of the reconstruction about its expected value is reduced by computing its bootstrap expectation. Based on the reconstruction computed from the observed projection data, synthetic projection data sets are simulated. Reconstructions of the synthetic projection data sets are averaged to yield the bootstrap expectation. This bootstrap procedure is a nonlinear filtering method. The procedure is automatic; no smoothing kernel or bandwidth parameter need be specified. For simulated data, the bootstrap method yielded somewhat sharper reconstructions than did an optimized linear approach. The method is applied to real data from a fluorodeoxiglucose study of the human brain. Near the boundaries, the resampling procedure yielded a sharper reconstruction. (C) 1996 John Wiley & Sons, Inc. RP Coakley, KJ (reprint author), NATL INST STAND & TECHNOL,US DEPT COMMERCE,STAT ENGN DIV,DIV 882,325 BROADWAY,BOULDER,CO 80303, USA. NR 25 TC 2 Z9 2 U1 0 U2 0 PU JOHN WILEY & SONS INC PI NEW YORK PA 605 THIRD AVE, NEW YORK, NY 10158-0012 SN 0899-9457 J9 INT J IMAG SYST TECH JI Int. J. Imaging Syst. Technol. PD SPR PY 1996 VL 7 IS 1 BP 54 EP 61 DI 10.1002/(SICI)1098-1098(199621)7:1<54::AID-IMA7>3.0.CO;2-T PG 8 WC Engineering, Electrical & Electronic; Optics; Imaging Science & Photographic Technology SC Engineering; Optics; Imaging Science & Photographic Technology GA UA654 UT WOS:A1996UA65400007 ER PT J AU Ehara, K Hagwood, C Coakley, KJ AF Ehara, K Hagwood, C Coakley, KJ TI Novel method to classify aerosol particles according to their mass-to-charge ratio - Aerosol particle mass analyser SO JOURNAL OF AEROSOL SCIENCE LA English DT Article AB A new method to classify aerosol particles according to their mass-to-charge ratio is proposed. This method works by balancing the electrostatic and centrifugal forces which act on particles introduced into a thin annular space formed between rotating cylindrical electrodes. Particles having a mass-to-charge ratio lying in a certain narrow range are taken out continuously as an aerosol suspension. A theoretical framework has been developed to calculate the transfer function which is defined as the ratio of the exiting particle dux to the entering particle flux. A similarity rule has been derived which states that a single nondimensional constant determines the shape of the transfer function. To examine the feasibility of the proposed principle, a prototype classifier was constructed, and the mass distribution of monodisperse particles nominally 0.309 mu m in diameter was measured. The peak structures corresponding to singly, doubly,and triply charged particles were identified in the experimental spectra. The difference between theory and experiment in the peak location for the singly charged particles was about 6.5% in terms of mass, or 2.3% in terms of diameter. C1 NIST,GAITHERSBURG,MD 20899. NIST,BOULDER,CO 80303. RP Ehara, K (reprint author), NATL RES LAB METROL,1-1-4 UMEZONO,TSUKUBA,IBARAKI 305,JAPAN. NR 23 TC 156 Z9 156 U1 3 U2 22 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD, ENGLAND OX5 1GB SN 0021-8502 J9 J AEROSOL SCI JI J. Aerosol. Sci. PD MAR PY 1996 VL 27 IS 2 BP 217 EP 234 DI 10.1016/0021-8502(95)00562-5 PG 18 WC Engineering, Chemical; Engineering, Mechanical; Environmental Sciences; Meteorology & Atmospheric Sciences SC Engineering; Environmental Sciences & Ecology; Meteorology & Atmospheric Sciences GA UF692 UT WOS:A1996UF69200003 ER PT J AU Banta, RM Olivier, LD Gudiksen, PH Lange, R AF Banta, RM Olivier, LD Gudiksen, PH Lange, R TI Implications of small-scale flow features to modeling dispersion over complex terrain SO JOURNAL OF APPLIED METEOROLOGY LA English DT Article ID DOPPLER LIDAR AB Small-scale, topographically forced wind systems often have a strong influence on flow over complex terrain. A problem is that these systems are very difficult to measure, because of their limited spatial and temporal extent. They can be important however, in the atmospheric transport of hazardous materials. For example, a nocturnal exit jet-a narrow stream of cold air-which flowed from Eldorado Canyon at the interface between the Rocky Mountains and the Colorado plains near the Rocky Flats Plant (RFP), swept over RFP for about 3 h in the middle of the night of 4-5 February 1991. It extended in depth from a few tens of meters to approximately 800 m above the ground. Because the jet was so narrow (2 km wide), it was poorly sampled by the meteorological surface mesonet, but it did prove to have an effect on the dispersion of tracer material released from RFP, producing a secondary peak in measured concentration to the southeast of RFP. The existence and behavior of the jet was documented by Environmental Technology Laboratory's Doppler lidar system, a scanning, active remote-sensing system that provides fine resolution wind measurements. The lidar was deployed as a part of a wintertime study of flow and dispersion in the RFP vicinity during February 1993. The MATHEW-ADPIC atmospheric dispersion model was run using the case study data from this night. It consists of three major modules: an interpolation scheme; MATHEW, a diagnostic wind-flow algorithm that calculates a mass-consistent interpolated flow; and ADPIC, a diffusion algorithm. The model did an adequate job of representing the main lobe of the tracer transport, but the secondary lobe resulting from the Eldorado Canyon exit jet was absent from the model result. Because the jet was not adequately represented in the input data, it did not appear in the modeled wind field. Thus, the effects of the jet on the transport of tracer material were not properly simulated by the diagnostic model. C1 LAWRENCE LIVERMORE NATL LAB,LIVERMORE,CA 94550. RP Banta, RM (reprint author), NOAA,ERL,ENVIRONM TECHNOL LAB,R-E-ET2,325 BROADWAY,BOULDER,CO 80303, USA. RI Darby, Lisa/A-8037-2009; Banta, Robert/B-8361-2008 OI Darby, Lisa/0000-0003-1271-0643; NR 36 TC 37 Z9 37 U1 1 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 MAR PY 1996 VL 35 IS 3 BP 330 EP 342 DI 10.1175/1520-0450(1996)035<0330:IOSSFF>2.0.CO;2 PG 13 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA UB905 UT WOS:A1996UB90500003 ER PT J AU Stankov, BB AF Stankov, BB TI Ground- and space-based temperature and humidity retrievals: Statistical evaluation SO JOURNAL OF APPLIED METEOROLOGY LA English DT Article ID MICROWAVE RADIOMETER; RASS; ASSIMILATION AB A near-real-time integrated temperature and water vapor sounding system has been designed and in operation since June 1993. It combines hourly data from the ground-based radio acoustic sounding system (RASS), a two-channel microwave radiometer, standard surface meteorological instruments, a lidar ceilometer, and the Aerodynamic Research Incorporated Communication, Addressing and Reporting System aboard commercial airlines with space-based data from the TIROS-N Operational Vertical Sounder (TOVS). The physical retrieval algorithm provided by the International TOVS Processing Package is used for combining the ground- and space-based temperature and humidity profiles. The first-guess profiles of temperature and humidity required by the physical retrieval algorithm are obtained by using a statistical inversion technique and the ground-based remote sensors measurements. Statistical error estimates are presented for the hourly, near-real-time, ground-, and space-based retrieved temperature and humidity profiles based on 119 soundings collected during a two-month-long experiment conducted at Platteville, Colorado, during February and March 1994. Radiosonde data collected by the Environmental Technology Laboratory and the Winter Icing and Storms Program in Platteville and the National Weather Service in Denver, Colorado, are used for comparison. The comparison showed excellent agreement between retrieved and radiosonde soundings. Retrieved temperature profiles show better performance than the retrieved humidity profiles because of the high vertical resolution of the RASS measurements. It is suggested that adding more information from the new individual remote sensors as they develop, through the technique used here, would lead to further profiling improvements. RP Stankov, BB (reprint author), NOAA,ENVIRONM TECHNOL LAB,325 BROADWAY,BOULDER,CO 80303, USA. NR 23 TC 6 Z9 6 U1 1 U2 1 PU AMER METEOROLOGICAL SOC PI BOSTON PA 45 BEACON ST, BOSTON, MA 02108-3693 SN 0894-8763 J9 J APPL METEOROL JI J. Appl. Meteorol. PD MAR PY 1996 VL 35 IS 3 BP 444 EP 463 DI 10.1175/1520-0450(1996)035<0444:GASBTA>2.0.CO;2 PG 20 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA UB905 UT WOS:A1996UB90500011 ER PT J AU Egelhoff, WF Chen, PJ Powell, CJ Stiles, MD McMichael, RD AF Egelhoff, WF Chen, PJ Powell, CJ Stiles, MD McMichael, RD TI Growth of giant magnetoresistance spin valves using indium as a surfactant SO JOURNAL OF APPLIED PHYSICS LA English DT Review ID MOLECULAR-BEAM EPITAXY; BY-LAYER GROWTH; AUGER-ELECTRON SPECTROSCOPY; SOLID-PHASE EPITAXY; MEDIATED GROWTH; ENHANCED MAGNETORESISTANCE; HOMOEPITAXIAL GROWTH; ISLAND FORMATION; FIELD GRADIENT; FILM GROWTH AB We have investigated the use of In as a surfactant to achieve smoother interfaces in spin-valve multilayers of the general type: FeMn/Ni80Fe20/Co/Cu/Co/Ni80Fe20/glass. The coupling field is reduced from similar to 0.8 to similar to 0.3 mT, presumably by suppressing roughness at the Co/Cu/Co interfaces, when 0.5-1.0 nm In is deposited on the first Co film just prior to Cu deposition or on the Cu film just prior to deposition of the second Co film. The In has a strong tendency to float-out to the surface during deposition of the spin valve leaving the spin-valve layers largely intact. The exchange bias at the FeMn/Ni80Fe20 interface can be increased from 12 to 25 mT by the use of thicker In (1.4 nm). RP Egelhoff, WF (reprint author), NIST,GAITHERSBURG,MD 20899, USA. RI McMichael, Robert/J-8688-2012; Stiles, Mark/K-2426-2012 OI McMichael, Robert/0000-0002-1372-664X; Stiles, Mark/0000-0001-8238-4156 NR 101 TC 66 Z9 69 U1 2 U2 11 PU AMER INST PHYSICS PI WOODBURY PA CIRCULATION FULFILLMENT DIV, 500 SUNNYSIDE BLVD, WOODBURY, NY 11797-2999 SN 0021-8979 J9 J APPL PHYS JI J. Appl. Phys. PD MAR 1 PY 1996 VL 79 IS 5 BP 2491 EP 2496 DI 10.1063/1.362659 PG 6 WC Physics, Applied SC Physics GA TY119 UT WOS:A1996TY11900047 ER PT J AU Weir, RD Goldberg, RN AF Weir, RD Goldberg, RN TI On the conversion of thermodynamic properties to the basis of the International Temperature Scale of 1990 SO JOURNAL OF CHEMICAL THERMODYNAMICS LA English DT Article ID SYNTHETIC SAPPHIRE ALPHA-AL2O3; STANDARD REFERENCE MATERIAL; ITS-90 AB The basis and application of the Douglas equations for the adjustment and calculation of differences in thermodynamic properties due to a change in the temperature scale are reviewed. When higher-order terms in the general Douglas equations are discarded, the simplified Douglas equations are obtained. These simplified equations together with the recently revised set of differences between values of temperatures on the International Temperature Scale of 1990 (ITS-90) and the corresponding values on the International Practical Temperature Scale of 1968 (IPTS-68) for 903.765 K < T-90 < 1337.33 K have been used to calculate approximate differences in thermodynamic properties for synthetic sapphire (alpha-Al2O3). Tables of differences (T-90-T-68)/K and the derivatives d(T-90-T-68)/dT are given as a function of T-68/K. (C) 1996 Academic Press Limited C1 NATL INST STAND & TECHNOL,GAITHERSBURG,MD 20899. RP Weir, RD (reprint author), ROYAL MIL COLL CANADA,DEPT CHEM & CHEM ENGN,KINGSTON,ON K7K 5L0,CANADA. NR 23 TC 24 Z9 24 U1 0 U2 1 PU ACADEMIC PRESS LTD PI LONDON PA 24-28 OVAL RD, LONDON, ENGLAND NW1 7DX SN 0021-9614 J9 J CHEM THERMODYN JI J. Chem. Thermodyn. PD MAR PY 1996 VL 28 IS 3 BP 261 EP 276 PG 16 WC Thermodynamics; Chemistry, Physical SC Thermodynamics; Chemistry GA UH703 UT WOS:A1996UH70300003 ER PT J AU Lopez, RE Holle, RL AF Lopez, RE Holle, RL TI Fluctuations of lightning casualties in the United States: 1959-1990 SO JOURNAL OF CLIMATE LA English DT Article ID SURFACE AB Long-term fluctuations in the number of lightning deaths and injuries from 1959 to 1990 have been examined for the contiguous United States. After taking into account the population increase, there was an overall trend amounting to a 30% reduction in casualties during the period. It is possible that this trend resulted from improved forecasts and warnings, increased education efforts of the public, and socioeconomic changes. In addition, there was a 40% reduction in the number of deaths but not of nonfatal injuries. This additional reduction in deaths was probably due to improved medical attention given to lightning victims and a wider knowledge of cardiopulmonary resuscitation techniques among the public. Improved medical care would increase the chances of a person surviving a lightning strike but would not affect the total number of casualties. Superimposed on the overall downward trend there were fluctuations of one or two decades in duration. From 1959 until 1968 there was a sharp reduction in the number of casualties, but starting in 1969 and continuing until the present, there was an overall increase. These oscillations appear to be climatologically related. The patterns of these fluctuations were parallel to nationwide changes in thunder-day frequencies, cyclone frequencies, and surface temperature values, representing thunderstorm, synoptic, and continental scales. RP Lopez, RE (reprint author), NOAA,NATL SEVERE STORMS LAB,1313 HALLEY CIRCLE,NORMAN,OK 73069, USA. NR 13 TC 17 Z9 19 U1 0 U2 1 PU AMER METEOROLOGICAL SOC PI BOSTON PA 45 BEACON ST, BOSTON, MA 02108-3693 SN 0894-8755 J9 J CLIMATE JI J. Clim. PD MAR PY 1996 VL 9 IS 3 BP 608 EP 615 DI 10.1175/1520-0442(1996)009<0608:FOLCIT>2.0.CO;2 PG 8 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA UJ642 UT WOS:A1996UJ64200005 ER PT J AU Steurer, PM AF Steurer, PM TI Probability distributions used in 100-year return period of air-freezing index SO JOURNAL OF COLD REGIONS ENGINEERING LA English DT Article AB The air-freezing index (AFI) is a measure of the combined magnitude and duration of air temperatures above and below freezing for a winter season. The 100-y return period of the AFI has been found to be an indicator of the amount of insulation required to protect a building foundation from frost heave and has been used to develop frost-protected shallow foundation (FPSF) design criteria FPSF has recently been accepted as a change to U.S. building codes with resulting annual construction savings estimated at $300 million nationally for new residential homes. Previous work has found that different probability distributions can produce significantly different estimates of the 100-y return period of the AFI and thus the amount of insulation required in FPSF. To determine which of several probability distributions best fit the AFI sample data, a goodness-of-fit test and graphical analyses have been applied to locations which have long-term and high-quality climate records. Results indicate that the Weibull probability distribution is the best choice for estimating 100-y return periods of the AFI for all U.S. climate regimes. RP Steurer, PM (reprint author), NATL ENVIRONM SATELLITE DATA & INFORMAT SERV,NATL CLIMAT DATA CTR,DATA BASE MANAGEMENT BRANCH,ASHEVILLE,NC 28801, USA. NR 13 TC 5 Z9 7 U1 0 U2 0 PU ASCE-AMER SOC CIVIL ENG PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017-2398 SN 0887-381X J9 J COLD REG ENG JI J. Cold Reg. Eng. PD MAR PY 1996 VL 10 IS 1 BP 25 EP 35 DI 10.1061/(ASCE)0887-381X(1996)10:1(25) PG 11 WC Engineering, Environmental; Engineering, Civil; Geosciences, Multidisciplinary SC Engineering; Geology GA TY005 UT WOS:A1996TY00500003 ER PT J AU Simiu, E Frey, MR AF Simiu, E Frey, MR TI Melnikov processes and noise-induced exits from a well SO JOURNAL OF ENGINEERING MECHANICS-ASCE LA English DT Article ID CHAOS; MODEL AB For a wide class of near-integrable systems with additive or multiplicative noise the mean zero upcrossing rate for the stochastic system's Melnikov process tau(u)(-1), provides an upper bound for the system's mean exit rate, tau(e)(-1). Comparisons between tau(u)(-1) and tau e(-1) show that in the particular case of additive white noise this upper bound is weak. For systems excited by processes with tail-limited distributions, the stochastic Melnikov approach yields a simple criterion guaranteeing the nonoccurrence of chaos. This is illustrated for the case of excitation by square-wave, coin-toss dichotomous noise. Finally, we briefly review applications of the stochastic Melnikov approach to a study of the behavior of wind-induced fluctuating currents over a corrugated ocean floor; -the snap-trough of buckled columns with continuous mass distribution and distributed random loading; and open-loop control of stochastically excited multistable systems. C1 BUCKNELL UNIV,DEPT MATH,LEWISBURG,PA 17837. RP Simiu, E (reprint author), NATL INST STAND & TECHNOL,BLDG & FIRE RES LAB,GAITHERSBURG,MD 20899, USA. NR 27 TC 19 Z9 19 U1 0 U2 0 PU ASCE-AMER SOC CIVIL ENG PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017-2398 SN 0733-9399 J9 J ENG MECH-ASCE JI J. Eng. Mech.-ASCE PD MAR PY 1996 VL 122 IS 3 BP 263 EP 270 DI 10.1061/(ASCE)0733-9399(1996)122:3(263) PG 8 WC Engineering, Mechanical SC Engineering GA TX575 UT WOS:A1996TX57500010 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 MAR 1 PY 1996 VL 101 IS A3 BP 5119 EP 5124 DI 10.1029/95JA03867 PG 6 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA TY349 UT WOS:A1996TY34900029 ER PT J AU Millward, GH Rishbeth, H FullerRowell, TJ Aylward, AD Quegan, S Moffett, RJ AF Millward, GH Rishbeth, H FullerRowell, TJ Aylward, AD Quegan, S Moffett, RJ TI Ionospheric F-2 layer seasonal and semiannual variations SO JOURNAL OF GEOPHYSICAL RESEARCH-SPACE PHYSICS LA English DT Article ID THERMOSPHERIC TEMPERATURE; GLOBAL-MODEL; SIMULATIONS; PLASMASPHERE; SUBSTORM; TROUGH; FIELD AB An extensive series of computations, using the Coupled Thermosphere-Ionosphere-Plasmasphere model (CTIP), has been undertaken to investigate the semiannual variation in peak noontime electron density, a common feature of the Fa-layer, particularly at low latitudes and in the southern hemisphere at mid-latitudes. Results from the model reveal such a variation, most prominently, at mid-latitudes, in the South American sector. An analysis of this phenomenon shows that it is intimately related to the large offset of the geomagnetic axis from Earths spin axis in the southern hemisphere. Because of this offset, a given geographic latitude in the South American sector corresponds to a lower magnetic latitude than in other sectors and is thus farther from the energy inputs associated with the auroral regions. As a result, the composition changes are much smaller during the winter months than at other longitudes, the mean molecular mass being essentially constant for a 4-month period centered on the winter solstice. This result is understood in terms of the global thermospheric circulation. In the absence of any composition changes, noon ionospheric density is influenced primarily by the solar zenith angle. This angle reaches a maximum at the winter Solstice, leading to diminished ion production, a minimum in N(m)F2, and therefore a semiannual variation overall. On the basis of the model results, the semiannual variation is seen as a feature of the midlatitude ionosphere at geographic longitudes opposite to the location of the geomagnetic pole. This phenomenon is seen in both northern and southern hemispheres, though the effect is much larger in the southern hemisphere as a result of the greater magnetic offset. C1 UNIV SOUTHAMPTON, DEPT PHYS, SOUTHAMPTON SO17 1BJ, HANTS, ENGLAND. UCL, ATMOSPHER PHYS LAB, DEPT PHYS & ASTRON, LONDON W1P 7PP, ENGLAND. UNIV SHEFFIELD, SCH MATH & STAT, UPPER ATMOSPHERE MODELLING GRP, SHEFFIELD S3 7RH, S YORKSHIRE, ENGLAND. RP UNIV COLORADO, NOAA, COOPERAT INST RES ENVIRONM SCI, SPACE ENVIRONM CTR, 325 BROADWAY, BOULDER, CO 80309 USA. NR 40 TC 102 Z9 108 U1 2 U2 3 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 2169-9380 EI 2169-9402 J9 J GEOPHYS RES-SPACE JI J. Geophys. Res-Space Phys. PD MAR 1 PY 1996 VL 101 IS A3 BP 5149 EP 5156 DI 10.1029/95JA03343 PG 8 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA TY349 UT WOS:A1996TY34900032 ER PT J AU Beavers, SC Cassano, ER AF Beavers, SC Cassano, ER TI Movements and dive behavior of a male sea turtle (Lepidochelys olivacea) in the eastern tropical Pacific SO JOURNAL OF HERPETOLOGY LA English DT Article ID DERMOCHELYS-CORIACEA; CARETTA-CARETTA; TRACKING C1 NATL MARINE FISHERIES SERV,SW FISHERIES SCI CTR,LA JOLLA,CA 92038. NR 45 TC 18 Z9 22 U1 2 U2 6 PU SOC STUD AMPHIBIANS REPTILES PI OXFORD PA DEPT OF ZOOLOGY MIAMI UNIV, OXFORD, OH 45056 SN 0022-1511 J9 J HERPETOL JI J. Herpetol. PD MAR PY 1996 VL 30 IS 1 BP 97 EP 104 DI 10.2307/1564720 PG 8 WC Zoology SC Zoology GA UA693 UT WOS:A1996UA69300022 ER PT J AU Keller, RR Phelps, JM AF Keller, RR Phelps, JM TI Scanning electron microscopy observations of misfit dislocations in epitaxial In0.25Ga0.75As on GaAs(001) SO JOURNAL OF MATERIALS RESEARCH LA English DT Article AB Dislocations in the misfit epitaxial film system In0.25Ga0.75As on GaAs(001) were imaged using a modified electron channeling contrast technique in a LaB6 SEM. We obtained images at an incident beam energy of 30 keV, a beam divergence of less than 1 mad and a specimen tilt of 70 degrees in conjunction with a movable scintillator detector mounted at a takeoff angle of approximately 3 degrees to 5 degrees. We achieved a spatial resolution of approximately 80 to 100 nm with this technique. Such resolution allowed rapid imaging of clusters consisting of only a few closely spaced dislocations in a 55 nm thick film. At such small film thicknesses, we did not require accurate knowledge of the incident beam direction in order to obtain sufficiently strong channeling contrast for qualitative characterization. The observed defect arrangements included features that we believe represent clustered threading segments. RP Keller, RR (reprint author), NATL INST STAND & TECHNOL,DIV MAT RELIABIL,325 BROADWAY,BOULDER,CO 80303, USA. RI Keller, Robert/I-9014-2012 NR 11 TC 2 Z9 2 U1 1 U2 2 PU MATERIALS RESEARCH SOCIETY PI PITTSBURGH PA 9800 MC KNIGHT ROAD SUITE 327, PITTSBURGH, PA 15237 SN 0884-2914 J9 J MATER RES JI J. Mater. Res. PD MAR PY 1996 VL 11 IS 3 BP 552 EP 554 DI 10.1557/JMR.1996.0067 PG 3 WC Materials Science, Multidisciplinary SC Materials Science GA TY914 UT WOS:A1996TY91400002 ER PT J AU Hunt, FY AF Hunt, FY TI Approximating the invariant measures of randomly perturbed dissipative maps SO JOURNAL OF MATHEMATICAL ANALYSIS AND APPLICATIONS LA English DT Article AB We present a method for approximating the invariant measure of a randomly perturbed mapping S of R(d). Cases where the unperturbed mapping is singular are considered, as are cases where the sizes of random jumps are unbounded. Existence of an invariant measure and convergence of the scheme are proved when the mapping has strong contraction properties. The implementation is designed to be useful in experimental situations where the map is known only approximately and the distribution of the noise is unknown. Under the same contraction conditions, we also prove that the invariant measure, the stationary measure of the associated Markov chain, is approached exponentially under iteration of the perturbed map, independent of the starting point. RP Hunt, FY (reprint author), NATL INST STAND & TECHNOL,COMP & APPL MATH LAB,GAITHERSBURG,MD 20899, USA. NR 20 TC 10 Z9 10 U1 0 U2 0 PU ACADEMIC PRESS INC JNL-COMP SUBSCRIPTIONS PI SAN DIEGO PA 525 B ST, STE 1900, SAN DIEGO, CA 92101-4495 SN 0022-247X J9 J MATH ANAL APPL JI J. Math. Anal. Appl. PD MAR 1 PY 1996 VL 198 IS 2 BP 534 EP 551 DI 10.1006/jmaa.1996.0097 PG 18 WC Mathematics, Applied; Mathematics SC Mathematics GA TZ289 UT WOS:A1996TZ28900014 ER PT J AU Chase, MW AF Chase, MW TI NIST-JANAF thermochemical tables for the oxygen fluorides SO JOURNAL OF PHYSICAL AND CHEMICAL REFERENCE DATA LA English DT Review DE evaluated/recommended data; literature survey; oxygen fluorides; spectroscopic properties; thermodynamic properties ID VERTICAL IONIZATION-POTENTIALS; POLYATOMIC TRANSIENT MOLECULES; DIODE-LASER SPECTROSCOPY; QUADRATIC CONFIGURATION-INTERACTION; VIBRATIONAL CHEMI-LUMINESCENCE; HYPERFINE COUPLING-CONSTANTS; LOW-TEMPERATURE SYNTHESIS; ELECTRONIC-ENERGY LEVELS; KINETIC DATA EVALUATION; SCF-MO METHOD AB The thermodynamic and spectroscopic properties of the oxygen fluoride species have been reviewed. Recommended thermochemical tables are given for five gaseous oxygen fluorides: OF, OFO, FOO, FOF, and O2F2. Sufficient information is not available to generate thermochemical tables for any condensed phase species. Annotated bibliographies (over 600 references) are provided for all neutral oxygen fluorides 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 five 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), NIST, STAND REFERENCE DATA PROGRAM, GAITHERSBURG, MD 20899 USA. NR 563 TC 27 Z9 27 U1 1 U2 11 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 MAR-APR PY 1996 VL 25 IS 2 BP 551 EP 603 PG 53 WC Chemistry, Multidisciplinary; Chemistry, Physical; Physics, Multidisciplinary SC Chemistry; Physics GA UE528 UT WOS:A1996UE52800001 ER PT J AU Outcalt, SL McLinden, MO AF Outcalt, SL McLinden, MO TI A modified Benedict-Webb-Rubin equation of state for the thermodynamic properties of R152a (1,1-difluoroethane) SO JOURNAL OF PHYSICAL AND CHEMICAL REFERENCE DATA LA English DT Article DE correlation; density; 1,1-difluoroethane; equation of state; heat capacity; pressure-volume-temperature; R152a; thermodynamic properties; vapor pressure ID LIQUID COEXISTENCE CURVE; THERMO-PHYSICAL PROPERTIES; 2ND VIRIAL-COEFFICIENTS; 1,1,1,2-TETRAFLUOROETHANE R-134A; VAPOR-PRESSURE; CRITICAL DENSITIES; R-152A; MIXTURES; 1-CHLORO-1,1-DIFLUOROETHANE; METHANE AB A modified Benedict-Webb-Rubin (MBWR) equation of state has been developed for R152a (1,1-difluoroethane). The correlation is based on a selection of available experimental thermodynamic property data. Single-phase pressure-volume-temperature (PVT), heat capacity, and sound speed data, as well as second virial coefficient, vapor pressure, and saturated liquid and saturated vapor density data, were used with multi-property linear least-squares fitting to determine the 32 adjustable coefficients of the MBWR equation. Ancillary equations representing the vapor pressure, saturated liquid and saturated vapor densities, and the ideal gas heat capacity were determined. Coefficients for the equation of state and the ancillary equations are given. Experimental data used in this work covered temperatures from 162 K to 453 K and pressures to 35 MPa. The MBWR equation established in this work may be used to predict thermodynamic properties of R152a from the triple-point temperature of 154.56 K to 500 K and for pressures up to 60 MPa except in the immediate vicinity of the critical point. (C) 1996 American Institute of Physics and American Chemical Society. RP Outcalt, SL (reprint author), NATL INST STAND & TECHNOL,DIV THERMOPHYS,BOULDER,CO 80303, USA. NR 47 TC 49 Z9 53 U1 0 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 MAR-APR PY 1996 VL 25 IS 2 BP 605 EP 636 PG 32 WC Chemistry, Multidisciplinary; Chemistry, Physical; Physics, Multidisciplinary SC Chemistry; Physics GA UE528 UT WOS:A1996UE52800002 ER PT J AU Ostrovsky, LA Zaborskikh, DV AF Ostrovsky, LA Zaborskikh, DV TI Damping of internal gravity waves by small-scale turbulence SO JOURNAL OF PHYSICAL OCEANOGRAPHY LA English DT Article AB The interaction between turbulence and internal waves in a stratified fluid with a shear how is considered on basis of perturbation theory permitting a description of internal wave damping by turbulence. The results show that the behavior of the damping rate for internal waves is rather anomalous for the long-wave range: it remains finite for such waves but may decrease to very small quantities in a restricted range of wavenumbers, depending on the mode structure. Detailed computations are made for the first three modes of the internal waves. The effects of anisotropy of the turbulent fluxes are also considered. For the case of constant buoyancy frequency an exact solution is obtained of the linearized semiempirical equations valid even for a strong wave damping. Estimates show that the damping by the upper turbulent layer may be an effective energy sink for long internal waves in the ocean. C1 INST PHYS APPL,NIZHNII NOVGOROD,RUSSIA. UNIV COLORADO,NOAA,COOPERAT INST RES ENVIRONM SCI,BOULDER,CO 80309. OI Ostrovsky, Lev/0000-0003-2233-1305 NR 13 TC 8 Z9 8 U1 1 U2 1 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 MAR PY 1996 VL 26 IS 3 BP 388 EP 397 DI 10.1175/1520-0485(1996)026<0388:DOIGWB>2.0.CO;2 PG 10 WC Oceanography SC Oceanography GA UJ603 UT WOS:A1996UJ60300007 ER PT J AU Ostrovsky, LA Kazakov, VI Matusov, PA Zaborskikh, DV AF Ostrovsky, LA Kazakov, VI Matusov, PA Zaborskikh, DV TI Experimental study of the internal wave damping on small-scale turbulence SO JOURNAL OF PHYSICAL OCEANOGRAPHY LA English DT Article ID STRATIFIED FLUIDS AB The interaction between internal waves (IW) and small-scale turbulence is investigated in a laboratory tank with thermocline-type stratification. Turbulence has been produced by an oscillating grid. Temperature and velocity measurements have been provided. The turbulent energy distribution and the dependence of the TW damping rate on the wavenumber have been measured. The damping rates for TW, calculated based on a semiempirical model for turbulence, demonstrate a quantitative agreement with experimental data. C1 UNIV COLORADO,NOAA,COOPERAT INST RES ENVIRONM SCI,ENVIRONM TECHNOL LAB,BOULDER,CO 80309. RUSSIAN ACAD SCI,INST PHYS APPL,NIZHNII NOVGOROD,RUSSIA. OI Ostrovsky, Lev/0000-0003-2233-1305 NR 19 TC 4 Z9 4 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 MAR PY 1996 VL 26 IS 3 BP 398 EP 405 DI 10.1175/1520-0485(1996)026<0398:ESOTIW>2.0.CO;2 PG 8 WC Oceanography SC Oceanography GA UJ603 UT WOS:A1996UJ60300008 ER PT J AU Douglas, J AF Douglas, J TI The general theory of irreversible processes in solutions of macromolecules - Comments SO JOURNAL OF POLYMER SCIENCE PART B-POLYMER PHYSICS LA English DT Editorial Material ID DILUTE POLYMER-SOLUTIONS; KIRKWOOD-RISEMAN MODEL; VISCOELASTIC RELAXATION; SEGMENT ORIENTATION; TAYLOR DISPERSION; EXCLUDED VOLUME; DYNAMICS; SEDIMENTATION; DIFFUSION; APPROXIMATION RP Douglas, J (reprint author), NIST,DIV POLYMERS,GAITHERSBURG,MD 20899, USA. NR 26 TC 0 Z9 0 U1 0 U2 0 PU JOHN WILEY & SONS INC PI NEW YORK PA 605 THIRD AVE, NEW YORK, NY 10158-0012 SN 0887-6266 J9 J POLYM SCI POL PHYS JI J. Polym. Sci. Pt. B-Polym. Phys. PD MAR PY 1996 VL 34 IS 4 BP 595 EP 596 DI 10.1002/polb.1996.896 PG 2 WC Polymer Science SC Polymer Science GA TX777 UT WOS:A1996TX77700003 ER PT J AU Park, K Zink, LR Evenson, KM Chance, KV Nolt, IG AF Park, K Zink, LR Evenson, KM Chance, KV Nolt, IG TI Pressure broadening of the 83.869 cm(-1) rotational lines of OH by N-2, O-2, H-2, and He SO JOURNAL OF QUANTITATIVE SPECTROSCOPY & RADIATIVE TRANSFER LA English DT Article ID RESONANCE; SPECTRUM AB We present pressure broadening coefficients of the 83.869 cm(-1) (2.514 THz) F-1, 5/2(-) <-- F-1, 3/2(+) rotational lines of OH by N-2, O-2, H-2, and He at 293 and 192 K. We also remeasured the position of the manifold of lines, with results that are in excellent agreement with a previous accurate determination. The frequency of the strongest component of the transition (F = 2 <-- 3) and its 2 sigma uncertainty is 2,514,316.37(3) MHz. C1 NATL INST STAND & TECHNOL,BOULDER,CO 80303. HARVARD SMITHSONIAN CTR ASTROPHYS,CAMBRIDGE,MA 02138. NASA,LANGLEY RES CTR,HAMPTON,VA 23681. RP Park, K (reprint author), UNIV OREGON,DEPT PHYS,EUGENE,OR 97403, USA. OI Chance, Kelly/0000-0002-7339-7577 NR 11 TC 16 Z9 16 U1 1 U2 3 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD, ENGLAND OX5 1GB SN 0022-4073 J9 J QUANT SPECTROSC RA JI J. Quant. Spectrosc. Radiat. Transf. PD MAR PY 1996 VL 55 IS 3 BP 285 EP 287 DI 10.1016/0022-4073(95)00172-7 PG 3 WC Optics; Spectroscopy SC Optics; Spectroscopy GA UA459 UT WOS:A1996UA45900002 ER PT J AU Nyden, MR Vallikul, P Sivathanu, YR AF Nyden, MR Vallikul, P Sivathanu, YR TI Tomographic reconstruction of the moments of local probability density functions in turbulent flow fields SO JOURNAL OF QUANTITATIVE SPECTROSCOPY & RADIATIVE TRANSFER LA English DT Article ID FLAMES AB An algorithm for the tomographic reconstruction of the individual moments of the probability density functions describing the local transmittance of radiation through a turbulent flow field is advanced. The new method, which is based on Fourier inversion, is applicable to asymmetric (as well as, to axisymmetric) flows. The validity of the method is examined by comparing reconstructed moments of the local probability functions in a buoyant propene/air flame and an ethene/air jet flame to the corresponding values obtained from optical probe measurements. C1 PURDUE UNIV,SCH MECH ENGN,W LAFAYETTE,IN 47907. RP Nyden, MR (reprint author), NATL INST STAND & TECHNOL,BLDG & FIRE RES LAB,GAITHERSBURG,MD 20899, USA. NR 15 TC 7 Z9 7 U1 0 U2 3 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD, ENGLAND OX5 1GB SN 0022-4073 J9 J QUANT SPECTROSC RA JI J. Quant. Spectrosc. Radiat. Transf. PD MAR PY 1996 VL 55 IS 3 BP 345 EP 356 DI 10.1016/0022-4073(95)00167-0 PG 12 WC Optics; Spectroscopy SC Optics; Spectroscopy GA UA459 UT WOS:A1996UA45900007 ER PT J AU Mackey, EA Anderson, DL ChenMayer, H Downing, RG Greenberg, RR Lamaze, GP Lindstrom, RM Mildner, DFR Paul, RL AF Mackey, EA Anderson, DL ChenMayer, H Downing, RG Greenberg, RR Lamaze, GP Lindstrom, RM Mildner, DFR Paul, RL TI Use of neutron beams for chemical analysis at NIST SO JOURNAL OF RADIOANALYTICAL AND NUCLEAR CHEMISTRY-ARTICLES LA English DT Article ID RAY ACTIVATION-ANALYSIS; PROMPT-GAMMA ACTIVATION; CAPILLARY OPTICS; SCATTERING; BORON; FACILITY; GUIDANCE; RATES AB At the National Institute of Standards and Technology, there are two techniques for chemical analysis that use neutron beams from the reactor for target irradiation: neutron depth profiling (NDP) and prompt gamma-ray activation analysis (PGAA). There are two facilities for each technique, one equipped with a thermal neutron beam and the other, with a cold neutron beam. In addition, focused beams of cold neutrons will be used to measure the two-dimensional element distributions by PGAA and three-dimensional distributions by NDP. This paper includes a brief description of the facilities, the measurement capabilities of each, some recent applications of NDP and PGAA, and neutron focusing as applied to these techniques. C1 US FDA,ELEMENTAL RES BRANCH HFS338,WASHINGTON,DC 20204. RP Mackey, EA (reprint author), NIST,DIV ANALYT CHEM,GAITHERSBURG,MD 20899, USA. NR 70 TC 2 Z9 2 U1 1 U2 2 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 MAR PY 1996 VL 203 IS 2 BP 413 EP 427 DI 10.1007/BF02041520 PG 15 WC Chemistry, Analytical; Chemistry, Inorganic & Nuclear; Nuclear Science & Technology SC Chemistry; Nuclear Science & Technology GA UM201 UT WOS:A1996UM20100014 ER PT J AU Cromer, CL Eppeldauer, G Hardis, JE Larason, TC Ohno, Y Parr, AC AF Cromer, CL Eppeldauer, G Hardis, JE Larason, TC Ohno, Y Parr, AC TI The NIST detector-based luminous intensity scale SO JOURNAL OF RESEARCH OF THE NATIONAL INSTITUTE OF STANDARDS AND TECHNOLOGY LA English DT Article DE calibration; candela; illuminance; lumen; luminous intensity; lux; measurement; photometer; photometry; scale; standards; units ID SILICON PHOTODIODES; TEMPERATURE; STANDARDS; CANDELA; USSR AB The Systeme International des Unites (SI) base unit for photometry, the candela, has been realized by using absolute detectors rather than absolute sources. This change in method permits luminous intensity calibrations of standard lamps to be carried out with a relative expanded uncertainty (coverage factor k = 2, and thus a 2 standard deviation estimate) of 0.46%, almost a factor-of-two improvement. A group of eight reference photometers has been constructed with silicon photodiodes, matched with filters to mimic the spectral luminous efficiency function for photopic vision. The wide dynamic range of the photometers aid in their calibration. The components of the photometers were carefully measured and selected to reduce the sources of error and to provide baseline data for aging studies. Periodic remeasurement of the photometers indicate that a yearly recalibration is required. The design, characterization, calibration, evaluation, and application of the photometers are discussed. C1 NIST, GAITHERSBURG, MD 20899 USA. NR 50 TC 33 Z9 33 U1 1 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 MAR-APR PY 1996 VL 101 IS 2 BP 109 EP 132 DI 10.6028/jres.101.014 PG 24 WC Instruments & Instrumentation; Physics, Applied SC Instruments & Instrumentation; Physics GA UN553 UT WOS:A1996UN55300001 PM 27805119 ER PT J AU Larason, TC Bruce, SS Cromer, CL AF Larason, TC Bruce, SS Cromer, CL TI The NIST high accuracy scale for absolute spectral response from 406 nm to 920 nm SO JOURNAL OF RESEARCH OF THE NATIONAL INSTITUTE OF STANDARDS AND TECHNOLOGY LA English DT Article DE absolute spectral response; cryogenic radiometer; light-trapping detectors; measurements; optical power; scale; silicon photodiode; quantum efficiency; quality system ID QUANTUM EFFICIENCY; SILICON AB We describe how the National Institute of Standards and Technology obtains a scale of absolute spectral response from 406 nm to 920 nm. This scale of absolute spectral response is based solely on detector measurements traceable to the NIST High Accuracy Cryogenic Radiometer (HACR). Silicon photodiode light-trapping detectors are used to transfer optical power measurements from the HACR to a monochromator-based facility where routine measurements are performed. The transfer also involves modeling the quantum efficiency (QE) of the silicon photodiode light-trapping detectors. We describe our planned quality system for these measurements that follows ANSI/NCSL Z540-1-1994. A summary of current NIST capabilities based on these measurements is also given. RP Larason, TC (reprint author), NIST, GAITHERSBURG, MD 20899 USA. NR 28 TC 35 Z9 35 U1 2 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 MAR-APR PY 1996 VL 101 IS 2 BP 133 EP 140 DI 10.6028/jres.101.015 PG 8 WC Instruments & Instrumentation; Physics, Applied SC Instruments & Instrumentation; Physics GA UN553 UT WOS:A1996UN55300002 PM 27805120 ER PT J AU Early, EA Thompson, A AF Early, EA Thompson, A TI Irradiance of horizontal quartz-halogen standard lamps SO JOURNAL OF RESEARCH OF THE NATIONAL INSTITUTE OF STANDARDS AND TECHNOLOGY LA English DT Article DE color temperature; lamp orientation; quartz-halogen lamps; spectral irradiance; standard lamps; ultraviolet AB Spectral irradiance calibrations often require that irradiance standard lamps be oriented differently than the normal calibration orientation used at the National Institute of Standards and Technology and at other standards laboratories. For example, in solar measurements the instruments are generally upward viewing, requiring horizontal working standards for minimization of irradiance calibration uncertainties. To develop a working standard for use in a solar ultraviolet intercomparison, NIST determined the irradiance of quartz-halogen lamps operating in the horizontal position, rather than in the customary vertical position. An experimental technique was developed which relied upon equivalent lamps with independent mounts for each orientation and a spectroradiometer with an integrating sphere whose entrance port could be rotated 90 degrees to view either lamp position. The results presented here are limited to 1000 W quartz-halogen type lamps at ultraviolet wavelengths from 280 nm to 400 nm. Sources of uncertainty arose from the lamps, the spectroradiometer, and the lamp alignment, and increased the uncertainty in the irradiance of horizontal lamps by less than a factor of two from that of vertical NIST standard lamps. The irradiance of horizontal lamps was less than that of vertical lamps by approximately 6% at long wavelengths (400 nm) to as much as 12% at the shortest wavelengths (280 nm). Using the Wien radiation law, this corresponds to color temperature differences of 15.7 K and 21.3 K for lamps with clear and frosted envelopes, respectively. RP Early, EA (reprint author), NIST, GAITHERSBURG, MD 20899 USA. NR 12 TC 17 Z9 17 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 MAR-APR PY 1996 VL 101 IS 2 BP 141 EP 153 DI 10.6028/jres.101.016 PG 13 WC Instruments & Instrumentation; Physics, Applied SC Instruments & Instrumentation; Physics GA UN553 UT WOS:A1996UN55300003 PM 27805121 ER PT J AU Moody, JR Vetter, TW AF Moody, JR Vetter, TW TI Development of the ion exchange-gravimetric method for sodium in serum as a definitive method SO JOURNAL OF RESEARCH OF THE NATIONAL INSTITUTE OF STANDARDS AND TECHNOLOGY LA English DT Article DE accuracy; definitive method; gravimetry; human serum; instrumental determination; ion-exchange; NCCLS; repeatability; sodium; uncertainty AB An ion exchange-gravimetric method, previously developed as a National Committee for Clinical Laboratory Standards (NCCLS) reference method for the determination of sodium in human serum, has been re-evaluated and improved. Sources of analytical error in this method have been examined more critically and the overall uncertainties decreased. Additionally, greater accuracy and repeatability have been achieved by the application of this definitive method to a sodium chloride reference material. In this method sodium in serum is ion-exchanged, selectively eluted and converted to a weighable precipitate as Na2SO4. Traces of sodium elating before or after the main fraction, and precipitate contaminants are determined instrumentally. Co-precipitating contaminants contribute less than 0.1% while the analyte lost to other eluted ion-exchange fractions contributes less than 0.02% to the total precipitate mass. With improvements, the relative expanded uncertainty (k = 2) of the method, as applied to serum, is 0.3% to 0.4% and is less than 0.1% when applied to a sodium chloride reference material. RP Moody, JR (reprint author), NIST, GAITHERSBURG, MD 20899 USA. NR 13 TC 11 Z9 11 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 MAR-APR PY 1996 VL 101 IS 2 BP 155 EP 164 DI 10.6028/jres.101.017 PG 10 WC Instruments & Instrumentation; Physics, Applied SC Instruments & Instrumentation; Physics GA UN553 UT WOS:A1996UN55300004 PM 27805122 ER PT J AU Anuta, MA Lozier, DW Turner, PR AF Anuta, MA Lozier, DW Turner, PR TI The MasPar MP-1 as a computer arithmetic laboratory SO JOURNAL OF RESEARCH OF THE NATIONAL INSTITUTE OF STANDARDS AND TECHNOLOGY LA English DT Article DE computer arithmetic; fixed-point and floating-point arithmetic; logarithmic and level-index arithmetic; residue number system arithmetic; serial and parallel simulation of computer arithmetic ID RESIDUE NUMBER SYSTEM; FLOATING-POINT; DIVISION ALGORITHM; PRECISION; REPRESENTATION; COMPUTATION AB This paper is a blueprint for the use of a massively parallel SIMD computer architecture for the simulation of various forms of computer arithmetic. The particular system used is a DEC/MasPar MP-1 with 4096 processors in a square array. This architecture has many advantages for such simulations due largely to the simplicity of the individual processors. Arithmetic operations can be spread across the processor array to simulate a hardware chip. Alternatively they may be performed on individual processors to allow simulation of a massively parallel implementation of the arithmetic. Compromises between these extremes permit speed-area tradeoffs to be examined. The paper includes a description of the architecture and its features. It then summarizes some of the arithmetic systems which have been, or are to be, implemented. The implementation of the level-index and symmetric level-index, LI and SLI, systems is described in some detail. An extensive bibliography is included. C1 NIST, GAITHERSBURG, MD 20899 USA. USN ACAD, ANNAPOLIS, MD 21402 USA. RP Anuta, MA (reprint author), CRAY RES INC, CALVERTON, MD 20705 USA. NR 85 TC 0 Z9 0 U1 0 U2 0 PU US GOVERNMENT PRINTING OFFICE PI WASHINGTON PA SUPERINTENDENT DOCUMENTS,, WASHINGTON, DC 20402-9325 USA SN 1044-677X J9 J RES NATL INST STAN JI J. Res. Natl. Inst. Stand. Technol. PD MAR-APR PY 1996 VL 101 IS 2 BP 165 EP 174 DI 10.6028/jres.101.018 PG 10 WC Instruments & Instrumentation; Physics, Applied SC Instruments & Instrumentation; Physics GA UN553 UT WOS:A1996UN55300005 PM 27805123 ER PT J AU Cage, ME AF Cage, ME TI Evidence that voltage rather than resistance is quantized in breakdown of the quantum Hall effect SO JOURNAL OF RESEARCH OF THE NATIONAL INSTITUTE OF STANDARDS AND TECHNOLOGY LA English DT Article DE breakdown; quantized dissipation; quantized resistance states; quantized voltage states; quantum Hall effect; quasi-elastic inter-Landau level scattering; two-dimensional electron gas AB Quantized longitudinal voltage drops are observed along a length of a GaAs/AlGaAs heterostructure quantum Hall effect device at applied currents large enough for the device to be in the breakdown regime. The range of currents is extensive enough to demonstrate that it is the longitudinal voltage that is quantized, rather than the longitudinal resistance. A black-box and a quasi-elastic inter-landau level scattering (QUILLS) model are then employed to calculate the fraction of electrons making transitions into higher Landau levels, the transition rates, and the maximum electric field across the device. RP Cage, ME (reprint author), NIST, GAITHERSBURG, MD 20899 USA. NR 18 TC 3 Z9 3 U1 0 U2 0 PU US GOVERNMENT PRINTING OFFICE PI WASHINGTON PA SUPERINTENDENT DOCUMENTS,, WASHINGTON, DC 20402-9325 USA SN 1044-677X J9 J RES NATL INST STAN JI J. Res. Natl. Inst. Stand. Technol. PD MAR-APR PY 1996 VL 101 IS 2 BP 175 EP 180 DI 10.6028/jres.101.019 PG 6 WC Instruments & Instrumentation; Physics, Applied SC Instruments & Instrumentation; Physics GA UN553 UT WOS:A1996UN55300006 PM 27805124 ER PT J AU Munro, RG Chen, H AF Munro, RG Chen, H TI Reference relations for the evaluation of the materials properties of orthorhombic YBa2Cu3Ox superconductors SO JOURNAL OF THE AMERICAN CERAMIC SOCIETY LA English DT Article ID NEUTRON POWDER DIFFRACTION; SINGLE-CRYSTALS; OXYGEN-CONTENT; TC; TEMPERATURE; BEHAVIOR; PRESSURE; 300-K AB Several expressions, suitable as reference relations, pertaining to the composition and temperature dependencies of the properties of orthorhombic YBa2Cu3Ox superconductors have been derived from statistical assessments of collections of data from independent experimental studies, Relations are given for (1) the critical temperature vs oxygen content, (2) the lattice parameters at room temperature vs oxygen content, (3) the lattice parameters at fixed oxygen content vs temperature, (4) the anisotropic thermal expansion vs temperature, (5) the isotropic polycrystalline thermal expansion vs temperature, and (6) the mass density vs temperature. RP Munro, RG (reprint author), NIST,DIV CERAM,GAITHERSBURG,MD 20899, USA. NR 22 TC 6 Z9 6 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 MAR PY 1996 VL 79 IS 3 BP 603 EP 608 PG 6 WC Materials Science, Ceramics SC Materials Science GA UB624 UT WOS:A1996UB62400005 ER PT J AU Wuttiphan, S Lawn, BR Padture, NP AF Wuttiphan, S Lawn, BR Padture, NP TI Crack suppression in strongly bonded homogeneous heterogeneous laminates: A study on glass glass-ceramic bilayers SO JOURNAL OF THE AMERICAN CERAMIC SOCIETY LA English DT Article ID SHARP CONTACT CRACKING; INDENTATION FLAWS; TOUGHNESS; STRENGTH; FRACTURE; DAMAGE; COMPOSITES; FATIGUE; DESIGN AB A study is made of a glass/glass ceramic bilayer as a model homogeneous/heterogeneous laminate. The underlying objective is microstructural design of ceramic layer systems with optimum mechanical properties, alternating hard layers, for wear resistance, with tough layers, for fracture resistance, Mica flakes in the glass-ceramic layer inhibit the propagation of well-developed intrusive cracks, by bridging; these same Bakes render the structure susceptible to distributed damage, by providing discrete weakness at the microstructural level. A major distinguishing feature of the bilayer design is the incorporation of a strong interface, so that cracks are inhibited by the underlayer rather than deflected between the layers, Vickers and Hertzian indentation tests on specimen cross sections demonstrate the capacity of the glass-ceramic layer to arrest radial and cone cracks penetrating from the adjacent glass layer, Additional Hertzian tests on the outer surfaces of glass layers in a coating/substrate configuration show diffuse damage accumulation in the glass-ceramic substrate layers, This diffuse damage absorbs energy and shields cone cracks in the glass from the applied loading, Implications concerening the design of damage-tolerant laminate structures are discussed. C1 NIST, MAT SCI & ENGN LAB, GAITHERSBURG, MD 20899 USA. UNIV CONNECTICUT, DEPT MET, STORRS, CT 06269 USA. UNIV CONNECTICUT, INST MAT SCI, STORRS, CT 06269 USA. RI Padture, Nitin/A-9746-2009 OI Padture, Nitin/0000-0001-6622-8559 NR 40 TC 71 Z9 72 U1 1 U2 13 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 MAR PY 1996 VL 79 IS 3 BP 634 EP 640 PG 7 WC Materials Science, Ceramics SC Materials Science GA UB624 UT WOS:A1996UB62400010 ER PT J AU Moon, PF Stabenau, EK AF Moon, PF Stabenau, EK TI Anesthetic and postanesthetic management of sea turtles SO JOURNAL OF THE AMERICAN VETERINARY MEDICAL ASSOCIATION LA English DT Article DE sea turtles; anesthesia, general; isoflurane ID CENTRAL CHEMICAL CONTROL; ACID-BASE; BLOOD; VENTILATION AB Objective-To examine the physiologic effects of inhalation anesthesia in aquatic turtles to improve anesthetic techniques and postanesthetic monitoring. Design-Retrospective case series. Animals-9 Kemp's ridley sea turtles. Procedure-Isoflurane was used as the general anesthetic during 14 minor surgical procedures. Turtles were orotracheally intubated, and a surgical plane of anesthesia was maintained with 2.7 +/- 0.4% (mean +/- SE) isoflurane. The duration of anesthesia was 131 +/- 12 minutes. Pulse rate, blood pressure, blood gases (Pa-O2 and Pa-CO2) and pH, blood lactic acid concentration, and capnography were used to evaluate the physiologic responses of sea turtles to isoflurane. Results-An isoflurane concentration of 3.4 +/- 0.3% provided anesthetic induction in 7 +/- 1 minutes. The mean duration of the recovery phase was 241 +/- 31 minutes. The duration of the recovery phase was not affected by the duration of anesthesia, type of carrier gas, method of ventilatory weaning, or use of selected pharmacologic agents. The recovery phase was characterized by hypoxemia, progressive acidemia, hypercapnia, and lactic acidosis. Awakening in the turtles was preceded by a characteristic tachycardia and tachypnea. All sea turtles recovered from isoflurane anesthesia without apparent adverse effects within 24 hours. Clinical Implications-Isoflurane appears to be safe and effective in providing surgical anesthesia in turtles that require a timely return to an aquatic environment. This study should assist veterinarians in predicting the physiologic responses of aquatic turtles to inhalation agents. C1 UNIV TEXAS,MED BRANCH,DEPT ANESTHESIOL,GALVESTON,TX 77550. UNIV TEXAS,MED BRANCH,DEPT PHYSIOL & BIOPHYS,GALVESTON,TX 77550. NATL MARINE FISHERIES SERV,GALVESTON LAB,GALVESTON,TX 77551. NR 25 TC 10 Z9 10 U1 0 U2 5 PU AMER VETERINARY MEDICAL ASSOC PI SCHAUMBURG PA 1931 N MEACHAM RD SUITE 100, SCHAUMBURG, IL 60173-4360 SN 0003-1488 J9 J AM VET MED ASSOC JI J. Am. Vet. Med. Assoc. PD MAR 1 PY 1996 VL 208 IS 5 BP 720 EP & PG 9 WC Veterinary Sciences SC Veterinary Sciences GA TX075 UT WOS:A1996TX07500018 PM 8617631 ER PT J AU Drummond, FJ Rogers, RR Cohn, SA Ecklund, WL Carter, DA Wilson, JS AF Drummond, FJ Rogers, RR Cohn, SA Ecklund, WL Carter, DA Wilson, JS TI A new look at the melting layer SO JOURNAL OF THE ATMOSPHERIC SCIENCES LA English DT Article ID PRECIPITATION AB The authors derive a relationship between the vertical Doppler spectrum of the rain just below the radar bright band and that of the snow just above. It neglects vertical air motions and assumes that each snowflake simply melts to form a raindrop of the same mass, disregarding other possible effects such as aggregation to form larger particles or breakup to create smaller ones. The relationship shows that, regardless of the dependence of particle fallspeed on size, the product of the equivalent reflectivity factor and the mean Doppler velocity of the snow is proportional to the same product for the rain, with a constant proportionality factor of 0.23, which equals the ratio of the dielectric factors of ice and water. Observed values of the reflectivity and mean Doppler velocity above and below the melting layer sometimes agree with this theoretical prediction but more often deviate from it in ways that may be interpreted as indicating the predominance of either aggregation or breakup processes. The data suggest that aggregation is occurring much of the time in the melting layer but that breakup effects become dominant in heavy precipitation. The analysis is extended by assuming relations between particle size and fallspeed for rain and snow. This enables the comparison of measured spectra with those derived theoretically. A simple allowance for aggregation or breakup in the spectral transformation from snow to rain is found to give improved spectral agreement in cases where these effects are indicated. C1 MCGILL UNIV,MONTREAL,PQ H3A 2K6,CANADA. UNIV COLORADO,NOAA,COOPERAT INST RES ENVIRONM SCI,BOULDER,CO 80309. NOAA,AERON LAB,BOULDER,CO 80303. NR 14 TC 25 Z9 26 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 MAR 1 PY 1996 VL 53 IS 5 BP 759 EP 769 DI 10.1175/1520-0469(1996)053<0759:ANLATM>2.0.CO;2 PG 11 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA TZ888 UT WOS:A1996TZ88800007 ER PT J AU Stickney, RR Hardy, RW Koch, K Harrold, R Seawright, D Massee, KC AF Stickney, RR Hardy, RW Koch, K Harrold, R Seawright, D Massee, KC TI The effects of substituting selected oilseed protein concentrates for fish meal in rainbow trout Oncorhynchus mykiss diets SO JOURNAL OF THE WORLD AQUACULTURE SOCIETY LA English DT Article ID SEA-WATER; DIGESTIBILITY; TSHAWYTSCHA; FEEDSTUFFS AB Three oilseed protein concentrates (soybean, canola, and sunflower) were evaluated to determine their potential, when supplemented with deficient essential amino acids, to partially or completely replace fish meal in diets fed to rainbow trout Oncorhynchus mykiss. Triplicate aquaria of juvenile trout (average weight of 12 g) were fed the experimental diets for 10 wk, at which time the average weight of the fish was approximately sixfold higher than the initial weight, Average fish weight gains on diets in which the protein component was 100% fish meal; 75% fish meal, 25% soybean protein concentrate; 50% fish meal, 50% soybean protein concentrate; and 75% fish meal, 25% sunflowerseed protein concentrate were not significantly different (P < 0.05). The average weight of fish fed a commercial feed was significantly lower than that of fish fed the 100% fish meal diet, but not significantly different from fish fed the three other formulations mentioned above. Fish fed diets containing 50% fish meal, 50% canola protein concentrate; and 25% fish meal, 75% sunflowerseed protein concentrate had significantly lower average final weights than those of fish fed the other diets. Feed conversion ratio patterns among the dietary treatment groups reflected those of weight gain, Fish survival exceeded 95% on all diets, Apparent protein digestibility coefficients ranged from 79.5% (75% soybean protein concentrate, 25% canola protein concentrate) to 90.6% (100% soybean protein concentrate). The results of this study demonstrated that certain oilseed protein concentrates have good potential as protein sources in rainbow bout feeds when properly supplemented with essential amino acids. C1 UNIV WASHINGTON,SCH FISHERIES,SEATTLE,WA 98195. NOAA,NATL MARINE FISHERIES SERV,NW FISHERIES SCI CTR,SEATTLE,WA 98112. N DAKOTA STATE UNIV,NO CROPS INST,FARGO,ND 58105. UNIV WASHINGTON,SCH FISHERIES,SEATTLE,WA 98195. NR 14 TC 62 Z9 68 U1 0 U2 8 PU WORLD AQUACULTURE SOCIETY PI BATON ROUGE PA LOUISIANA STATE UNIV, 143 J M PARKER COLISEUM, BATON ROUGE, LA 70803 SN 0893-8849 J9 J WORLD AQUACULT SOC JI J. World Aquacult. Soc. PD MAR PY 1996 VL 27 IS 1 BP 57 EP 63 DI 10.1111/j.1749-7345.1996.tb00594.x PG 7 WC Fisheries SC Fisheries GA UM235 UT WOS:A1996UM23500008 ER PT J AU Yuan, CW Zheng, Z deLozanne, AL Tortonese, M Rudman, DA Eckstein, JN AF Yuan, CW Zheng, Z deLozanne, AL Tortonese, M Rudman, DA Eckstein, JN TI Vortex images in thin films of YBa2Cu3O7-x and Bi2Sr2Ca1Cu2O8+x obtained by low-temperature magnetic force microscopy SO JOURNAL OF VACUUM SCIENCE & TECHNOLOGY B LA English DT Article; Proceedings Paper CT 8th International Conference on Scanning Tunneling Microscopy and Related Methods (STM 95) CY JUL 25-29, 1995 CL SNOWMASS, CO SP Amer Vacuum Soc, AVS Nanometerscale Sci & Technol Div, Naval Res Lab, USN, Off Naval Res, USA Res Off, Natl Sci Fdn ID SCANNING-TUNNELING-MICROSCOPY; ATOMIC-FORCE; SUPERCONDUCTOR; VORTICES; LATTICES AB We have imaged vortices in superconducting thin films with a low-temperature magnetic force microscope that utilizes microfabricated piezoresistive cantilevers with built-in tips. The films of YBa2Cu3O7-delta and Bi2Sr2Ca1Cu2O8+x, are made by laser ablation and molecular beam epitaxy, respectively, The vortices usually appear as round features in the noncontact image with a diameter of about 1 mu m or slightly less. In some cases the position of the vortices is correlated to defects observed in the topographic image of the same area. The vortices move sometimes, especially after taking a topographic (contact mode) scan. C1 UNIV TEXAS,DEPT PHYS,AUSTIN,TX 78712. PK SCI INSTRUMENTS,SUNNYVALE,CA 94089. NIST,BOULDER,CO 80303. VARIAN ASSOCIATES INC,EL GINZTON RES CTR,PALO ALTO,CA 94304. RI de Lozanne, Alex/C-9693-2013 OI de Lozanne, Alex/0000-0003-2950-4707 NR 15 TC 33 Z9 33 U1 0 U2 2 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 MAR-APR PY 1996 VL 14 IS 2 BP 1210 EP 1213 DI 10.1116/1.588516 PG 4 WC Engineering, Electrical & Electronic; Nanoscience & Nanotechnology; Physics, Applied SC Engineering; Science & Technology - Other Topics; Physics GA UH890 UT WOS:A1996UH89000128 ER PT J AU Poirier, GE AF Poirier, GE TI Butanethiol self-assembly on Au(001): The 1x4 Au missing row, c(2x8) molecular lattice SO JOURNAL OF VACUUM SCIENCE & TECHNOLOGY B LA English DT Article; Proceedings Paper CT 8th International Conference on Scanning Tunneling Microscopy and Related Methods (STM 95) CY JUL 25-29, 1995 CL SNOWMASS, CO SP Amer Vacuum Soc, AVS Nanometerscale Sci & Technol Div, Naval Res Lab, USN, Off Naval Res, USA Res Off, Natl Sci Fdn ID SCANNING-TUNNELING-MICROSCOPY; RAY PHOTOELECTRON-SPECTROSCOPY; RECONSTRUCTED AU(100) SURFACE; MEDIATED ELECTRON-TRANSFER; OXIDIZED ALUMINUM SURFACE; NORMAL-ALKANOIC ACIDS; STRUCTURAL CHARACTERIZATION; MONOLAYER FILMS; SCATTERING MEASUREMENTS; ORGANOSULFUR COMPOUNDS AB We have characterized the molecular packing structure of butanethiol self-assembled monolayers (SAMs) on Au(001) using an ultrahigh vacuum scanning tunneling microscope. Butanethiol SAMs were formed on the clean surface using two different protocols: deposition by gas-phase transport and deposition from ethanol solution. The SAM growth proceeds by nucleation and growth of compact, anisotropic islands. The island growth results in relaxation of the compressed Au(001)(5 x 20) reconstruction with concomitant ejection of excess Au atoms onto the terraces. Although the reconstructed surface contains 0.26 monolayer excess Au atoms, 0.4 monolayer is ejected. The surface Au atoms arrange to form identical 1 x 4 missing row structures on both the original terrace level and the nascent island level. The thiols pack in a commensurate, distorted-hexagonal overlayer on this (1 x 4) missing row structure forming a c(2 x 8) molecular lattice. (C) 1996 American Vacuum Society. RP Poirier, GE (reprint author), NIST,GAITHERSBURG,MD 20899, USA. NR 65 TC 44 Z9 44 U1 0 U2 5 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 MAR-APR PY 1996 VL 14 IS 2 BP 1453 EP 1460 DI 10.1116/1.589118 PG 8 WC Engineering, Electrical & Electronic; Nanoscience & Nanotechnology; Physics, Applied SC Engineering; Science & Technology - Other Topics; Physics GA UH890 UT WOS:A1996UH89000181 ER PT J AU Villarrubia, JS AF Villarrubia, JS TI Scanned probe microscope tip characterization without calibrated tip characterizers SO JOURNAL OF VACUUM SCIENCE & TECHNOLOGY B LA English DT Article; Proceedings Paper CT 8th International Conference on Scanning Tunneling Microscopy and Related Methods (STM 95) CY JUL 25-29, 1995 CL SNOWMASS, CO SP Amer Vacuum Soc, AVS Nanometerscale Sci & Technol Div, Naval Res Lab, USN, Off Naval Res, USA Res Off, Natl Sci Fdn ID COLLOIDAL GOLD; METROLOGY AB In scanned probe microscopy the image is a combination of information from the sample and the tip. In order to reconstruct the true surface geometry, it is necessary to know the actual tip shape. It has been proposed that this shape may be reconstructed from images of ''tip characterizer'' artifacts of independently known shape. The requirements for this strategy-dimensional uncertainty and instability of the characterizer small compared to the tip size-are not trivial. An alternative is ''blind reconstruction,'' which requires no information about the characterizer geometry apart from that contained within its image, yet produces an outer bound on the tip shape which for appropriately chosen characterizers is a good approximation. With blind reconstruction dimensional instability of characterizers is less problematical, and characterizer measurability is no longer a constraint, so more complex distributed characterizer geometries may be advantageously employed. in situations where part of a characterizer has a known shape, blind reconstruction and the known-characterizer method may be combined. RP Villarrubia, JS (reprint author), NIST,GAITHERSBURG,MD 20899, USA. NR 21 TC 80 Z9 83 U1 3 U2 7 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 MAR-APR PY 1996 VL 14 IS 2 BP 1518 EP 1521 DI 10.1116/1.589130 PG 4 WC Engineering, Electrical & Electronic; Nanoscience & Nanotechnology; Physics, Applied SC Engineering; Science & Technology - Other Topics; Physics GA UH890 UT WOS:A1996UH89000193 ER PT J AU Schneir, J Villarrubia, JS McWaid, TH Tsai, VW Dixson, R AF Schneir, J Villarrubia, JS McWaid, TH Tsai, VW Dixson, R TI Increasing the value of atomic force microscopy process metrology using a high-accuracy scanner, tip characterization, and morphological image analysis SO JOURNAL OF VACUUM SCIENCE & TECHNOLOGY B LA English DT Article; Proceedings Paper CT 8th International Conference on Scanning Tunneling Microscopy and Related Methods (STM 95) CY JUL 25-29, 1995 CL SNOWMASS, CO SP Amer Vacuum Soc, AVS Nanometerscale Sci & Technol Div, Naval Res Lab, USN, Off Naval Res, USA Res Off, Natl Sci Fdn ID SCALE AB Atomic force microscopes are being used increasingly for process metrology. As a case study, the measurement by atomic force microscope of a soda lime glass optical disk patterned using optical lithography and reactive plasma etching is examined. The atomic force microscope used for this measurement has a highly accurate scanner system. The X, Y, and Z axes are calibrated using laser interferometry. To determine the shape of the tip used a commercially available tip calibration artifact was imaged both before and after the measurement. The image was corrected for the tip shape using mathematical morphology. The value of the atomic force microscope measurement is defined to be the impacts of the metrology on the product or process. It is shown that the value of atomic force microscopy process metrology on an optical disk is increased by using an accurate scanner, tip characterization, and morphological image analysis; however, the cost per measurement is increased as well. In general, the characteristics of the metrology required depends on the specific manufacturing process being supported. RP Schneir, J (reprint author), NIST,GAITHERSBURG,MD 20899, USA. NR 34 TC 11 Z9 11 U1 1 U2 1 PU AMER INST PHYSICS PI WOODBURY PA CIRCULATION FULFILLMENT DIV, 500 SUNNYSIDE BLVD, WOODBURY, NY 11797-2999 SN 1071-1023 J9 J VAC SCI TECHNOL B JI J. Vac. Sci. Technol. B PD MAR-APR PY 1996 VL 14 IS 2 BP 1540 EP 1546 DI 10.1116/1.589135 PG 7 WC Engineering, Electrical & Electronic; Nanoscience & Nanotechnology; Physics, Applied SC Engineering; Science & Technology - Other Topics; Physics GA UH890 UT WOS:A1996UH89000198 ER PT J AU Raithel, G Benson, O Walther, H AF Raithel, G Benson, O Walther, H TI Dynamics of the micromaser field SO LASER PHYSICS LA English DT Article; Proceedings Paper CT International Symposium on Laser Physics (MPLP 95) CY AUG 28-SEP 02, 1995 CL ADADEMGORODOK, NOVOSIBIRSK, RUSSIA SP Russian Acad Sci, Inst Laser Phys, Russian Acad Sci, Inst Spectroscopy HO ADADEMGORODOK ID MASER AB The field of the one-atom maser or micromaser shows abrupt variations of its strength in certain parameter regions. In this paper the time behavior of the field in the vicinity of those regions is investigated. The transition rate between the metastable states depends on the experimental parameters. Hysteresis behavior also occurs. The experimental results are compared to a quantum Monte Carlo simulation of the maser field as well as to the result of a Fokker-Planck treatment used earlier in connection with micromaser theory. In the case of high pump rates, Ramsey-type interference structures in the micromaser resonance lines are observed. The resonance lines are obtained by recording the atomic inversion while scanning the cavity frequency across the atomic resonance. The interferences occur owing to the mixing of the coupled states of the atom-held system at the entrance and exit holes of the cavity, this leading to a Ramsey-type atom-field interaction scheme. The interference patterns observed in the experiment are approximately periodic. Individual interference fringes are triangular-shaped, whereby the steep high-frequency edges are related to metastability and hysteresis phenomena of the maser held. The observations are explained on the basis of a modified micromaser theory. RP Raithel, G (reprint author), NATL INST STAND & TECHNOL,GAITHERSBURG,MD 20899, USA. NR 9 TC 0 Z9 0 U1 0 U2 0 PU INTERPERIODICA PI BIRMINGHAM PA PO BOX 1831, BIRMINGHAM, AL 35201-1831 SN 1054-660X J9 LASER PHYS JI Laser Phys. PD MAR-APR PY 1996 VL 6 IS 2 BP 354 EP 358 PG 5 WC Optics; Physics, Applied SC Optics; Physics GA UJ891 UT WOS:A1996UJ89100029 ER PT J AU Sogard, SM Olla, BL AF Sogard, SM Olla, BL TI Food deprivation affects vertical distribution and activity of a marine fish in a thermal gradient: Potential energy-conserving mechanisms SO MARINE ECOLOGY PROGRESS SERIES LA English DT Article DE behavior; temperature; starvation; bioenergetics; Walleye pollock ID POLLOCK THERAGRA-CHALCOGRAMMA; JUVENILE WALLEYE POLLOCK; EASTERN BERING SEA; DICENTRARCHUS-LABRAX; ONCORHYNCHUS-NERKA; TEMPERATURE-CHANGE; PREDATOR PRESENCE; SALMO-GAIRDNERI; SOCKEYE-SALMON; RAINBOW-TROUT AB The effects of reduced food availability on the behavior of juvenile walleye pollock Theragra chalcogramma were examined in laboratory experiments designed to test for potential energy-conserving responses. Groups of juvenile fish were held on 1 of 6 ration treatments ranging from ad libitum to near starvation, and then vertical distribution and activity levels were quantified in a 2.5 m deep water column under isothermal and thermally stratified conditions. Stratification resulted in a general shift to the upper, warmer layer in the 2 experiments employing a sharp thermocline at mid-depth, but the occurrence of fish in the colder bottom layer varied with different ration treatments. Movement into cold water increased in intermediate ration groups compared to high ration groups. Since reduced temperatures should reduce metabolic costs, this behavior is consistent with our hypothesis that food deprivation should invoke energy-saving behaviors. However, activity levels increased for fish held on intermediate rations, suggesting that the greater movement into cold water was a corollary result of increased searching for food. Fish in the lowest ration treatments had decreased activity levels, but also decreased their movement into cold water when a sharp thermocline was present, negating potential bioenergetic benefits. In the third experiment, there was a gradual thermal gradient from surface to bottom rather than a sharp thermocline. Temperatures associated with vertical positions of the fish were determined. In this experiment, clear energy-conserving responses to temperature were displayed by food-deprived fish; the average temperatures occupied by fish on starvation rations were 3 to 4 degrees C colder than those of the higher ration groups. Based on the high Q(10) for metabolic rates of juvenile pollock, these reduced temperatures potentially conferred energy savings of up to 34%, relative to the metabolic expenditures of fish on high rations. The contrast in behavior for the lowest ration groups between sharply stratified and gradually stratified conditions suggested that the severity of the temperature gradient influenced the fishes' ability to take advantage of cold water as an energetic refuge. The behavior of fish in the laboratory was consistent with prior observations in the Bering Sea, where juvenile walleye pollock remained in surface waters if food availability was high, but initiated vertical migration into deeper, colder water with reduced prey densities. Results of this study demonstrated a broad flexibility in the behavioral mechanisms used by walleye pollock to deal with declining food levels. The initial response to food limitation was increased activity, indicative of greater searching behavior. With extended food deprivation, a switch to energy-conserving behavior was evident. The temperature responses of fish experiencing severe food limitation provided support for a bioenergetic hypothesis of diel vertical migration. RP Sogard, SM (reprint author), OREGON STATE UNIV, HATFIELD MARINE SCI CTR, NATL MARINE FISHERIES SERV, ALASKA FISHERIES SCI CTR, NEWPORT, OR 97365 USA. NR 64 TC 71 Z9 71 U1 1 U2 18 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 MAR PY 1996 VL 133 IS 1-3 BP 43 EP 55 DI 10.3354/meps133043 PG 13 WC Ecology; Marine & Freshwater Biology; Oceanography SC Environmental Sciences & Ecology; Marine & Freshwater Biology; Oceanography GA UG429 UT WOS:A1996UG42900004 ER PT J AU Gardner, WS Benner, R Amon, RMW Cotner, JB Cavaletto, JF Johnson, JR AF Gardner, WS Benner, R Amon, RMW Cotner, JB Cavaletto, JF Johnson, JR TI Effects of high-molecular-weight dissolved organic matter on nitrogen dynamics in the Mississippi River plume SO MARINE ECOLOGY PROGRESS SERIES LA English DT Article DE dissolved organic carbon; nitrogen cycling; ammonium; bacteria; phytoplankton; amino acids ID COMBINED AMINO-ACIDS; SUB-ARCTIC PACIFIC; ISOTOPE-DILUTION; LAKE-MICHIGAN; HETEROTROPHIC BACTERIOPLANKTON; MARINE-PHYTOPLANKTON; PLANKTONIC BACTERIA; AMMONIUM; CARBON; RATES AB The dynamics of N and its interactions with labile dissolved organic C (DOC), bacteria, and phytoplankton were studied to determine potential effects of dissolved organic matter (DOM) and light on N dynamics in surface waters of the Mississippi River (USA) plume in the Gulf of Mexico. Bacterial uptake of added labeled N compounds ((NH4+)-N-15 or N-15-labeled dissolved free amino acids, DFAA) was stimulated more by high-molecular-weight (HMW, >1 kDa) DOM than by low-molecular-weight (LMW, <1 kDa) DOM. An index that inversely indicated the presence of labile DOC was defined as the fraction of assimilated Amino acid-N-15 that was Recovered as N-15-Ammonium (ANRA), following the additions of high-levels (4 mu M) of N-15-DFAA. ANRA ratios were high in the absence of other available carbon sources because heterotrophic bacteria were forced to use the added amino acids as a carbon source for respiration rather than as a nutrient source for biomass formation. In dynamic light/dark experiments, conducted with in situ populations of organisms, uptake rates of added (NH4+)-N-15 were significantly enhanced both by the presence of light and by the addition of HMW DOM. Uptake rates of added N-15-labeled DFAA were increased by the addition of HMW DOM but not by light. ANRA ratios were consistently lower in the presence of added HMW DOM than in controls. Added HMW DOM thus appeared to stimulate the incorporation of assimilated DFAA into bacterial biomass. Bacterial growth rates were relatively high in both light and dark bottles with DFAA additions and in light bottles with HMW DOM plus NH4+ additions, but they remained comparatively low in dark bottles with added NH4+. These results are consistent with the idea that bacterial N dynamics in these euphotic waters may be tightly coupled to photosynthetic activities over short time scales. C1 UNIV TEXAS, INST MARINE SCI, PORT ARANSAS, TX 78373 USA. TEXAS A&M UNIV, DEPT FISHERIES & WILDLIFE SCI, COLLEGE STN, TX 77843 USA. UNIV MICHIGAN, COOPERAT INST LIMNOL & ECOSYST RES, ANN ARBOR, MI 48109 USA. RP Gardner, WS (reprint author), NOAA, GREAT LAKES ENVIRONM RES LAB, 2205 COMMONWEALTH BLVD, ANN ARBOR, MI 48105 USA. RI Benner, Ronald/M-4412-2015 OI Benner, Ronald/0000-0002-1238-2777 NR 47 TC 39 Z9 39 U1 1 U2 15 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 MAR PY 1996 VL 133 IS 1-3 BP 287 EP 297 DI 10.3354/meps133287 PG 11 WC Ecology; Marine & Freshwater Biology; Oceanography SC Environmental Sciences & Ecology; Marine & Freshwater Biology; Oceanography GA UG429 UT WOS:A1996UG42900024 ER PT J AU Mizuseki, H Ishihara, M Hu, XA Hashi, Y Kawazoe, Y AF Mizuseki, H Ishihara, M Hu, XA Hashi, Y Kawazoe, Y TI Spin-reorientation transition in superlattices by large scale dynamic simulation SO MATERIALS TRANSACTIONS JIM LA English DT Article DE magnetic multi-valued(MMV) recording; magnetic artificial lattice; axis of easy magnetization; magnetic anisotropy AB New magnetic configurations in 2D and 3D artificial lattices are studied by solving the non-linear equation based on the classical two- or three- dimensional Heisenberg models with full long range dipolar interaction. The results indicate strong possibility to be used as an ultra-high density magnetic recording media achieved by magnetic multi-valued(MMV) recording. The magnetic properties and the density of MMV recording are discussed based on the magnetic anisotropic configurations in 2D and 3D artificial lattices. C1 NATL INST STAND & TECHNOL,BOULDER,CO 80303. RP Mizuseki, H (reprint author), TOHOKU UNIV,INST MAT RES,SENDAI,MIYAGI 98077,JAPAN. RI Kawazoe, Yoshiyuki/C-2998-2011; Mizuseki, Hiroshi/A-8891-2011 OI Mizuseki, Hiroshi/0000-0003-0973-7693 NR 4 TC 6 Z9 6 U1 0 U2 0 PU JAPAN INST METALS PI SENDAI PA AOBA ARAMAKI, SENDAI 980, JAPAN SN 0916-1821 J9 MATER T JIM JI Mater. Trans. JIM PD MAR PY 1996 VL 37 IS 3 BP 478 EP 481 PG 4 WC Materials Science, Multidisciplinary; Metallurgy & Metallurgical Engineering SC Materials Science; Metallurgy & Metallurgical Engineering GA UJ700 UT WOS:A1996UJ70000053 ER PT J AU Boettinger, WJ Warren, JA AF Boettinger, WJ Warren, JA TI The phase-field method: Simulation of alloy dendritic solidification during recalescence SO METALLURGICAL AND MATERIALS TRANSACTIONS A-PHYSICAL METALLURGY AND MATERIALS SCIENCE LA English DT Article; Proceedings Paper CT Symposium on Analysis and Modeling of Solidification CY OCT 02-06, 1994 CL ROSEMONT, IL SP TMS Solidification Comm ID SOLUTE REDISTRIBUTION; RAPID SOLIDIFICATION; CRYSTAL-GROWTH; MODEL; DIFFUSION; INTERFACE; MICROSEGREGATION; DYNAMICS; BOUNDARY AB An overview of the phase-field method for modeling solidification is given and results for nonisothermal alloy dendritic growth are presented. By defining a ''phase-field'' variable and a corresponding governing equation to describe the state (solid or liquid) in a material as a function of position and time, the diffusion equations for heat and solute can be solved without tracking the liquid-solid interface. The interfacial regions between liquid and solid involve smooth, but highly localized variations of the phase-field variable and the composition. Simple finite-difference techniques on a uniform mesh can be used to treat the evolution of complex growth patterns. However, large-scale computations are required. The method has been applied to a variety of problems, including thermally driven dendritic growth in pure materials, solute-driven isothermal dendritic growth in alloys, eutectic growth (all at high supercoolings or supersaturations), solute trapping at high velocity, and coarsening of liquid-solid mixtures. To include thermal effects in solute-driven dendritic growth in alloys, a simplified approach is presented here that neglects the spatial variation of temperature in the computational domain but provides for changes with time and thus includes recalescence. Growth morphologies and solute patterns in the liquid and solid obtained for several values of an imposed heat flux are compared to results for isothermal growth. RP NIST, DIV MET, MAT SCI & ENGN LAB, GAITHERSBURG, MD 20899 USA. NR 52 TC 80 Z9 89 U1 6 U2 20 PU SPRINGER PI NEW YORK PA 233 SPRING ST, NEW YORK, NY 10013 USA SN 1073-5623 EI 1543-1940 J9 METALL MATER TRANS A JI Metall. Mater. Trans. A-Phys. Metall. Mater. Sci. PD MAR PY 1996 VL 27 IS 3 BP 657 EP 669 DI 10.1007/BF02648953 PG 13 WC Materials Science, Multidisciplinary; Metallurgy & Metallurgical Engineering SC Materials Science; Metallurgy & Metallurgical Engineering GA UC668 UT WOS:A1996UC66800012 ER PT J AU Coriell, SR Murray, BT Chernov, AA McFadden, GB AF Coriell, SR Murray, BT Chernov, AA McFadden, GB TI Effects of shear flow and anisotropic kinetics on the morphological stability of a binary alloy SO METALLURGICAL AND MATERIALS TRANSACTIONS A-PHYSICAL METALLURGY AND MATERIALS SCIENCE LA English DT Article; Proceedings Paper CT Symposium on Analysis and Modeling of Solidification CY OCT 02-06, 1994 CL ROSEMONT, IL SP TMS Solidification Comm ID UNIDIRECTIONAL SOLIDIFICATION; VICINAL FACE AB The effect of a parallel shear flow and anisotropic interface kinetics on the onset of instability during the directional solidification of a binary alloy at constant velocity is calculated. The model for anisotropy is based on the motion of steps. A shear flow (linear Couette flow or asymptotic suction profile), parallel to the crystal-melt interface in the same direction as the step motion, decreases interface stability in that the critical solute concentration decreases. A shear flow counter to the step motion enhances stability for small shear rates; for larger shear rates, the neutral curve develops a bimodal structure, and the critical solute concentration slowly decreases with shear rate. RP Coriell, SR (reprint author), NATL INST STAND & TECHNOL,GAITHERSBURG,MD 20899, USA. RI McFadden, Geoffrey/A-7920-2008 OI McFadden, Geoffrey/0000-0001-6723-2103 NR 30 TC 11 Z9 11 U1 0 U2 2 PU MINERALS METALS MATERIALS SOC PI WARRENDALE PA 420 COMMONWEALTH DR, WARRENDALE, PA 15086 SN 1073-5623 J9 METALL MATER TRANS A JI Metall. Mater. Trans. A-Phys. Metall. Mater. Sci. PD MAR PY 1996 VL 27 IS 3 BP 687 EP 694 DI 10.1007/BF02648955 PG 8 WC Materials Science, Multidisciplinary; Metallurgy & Metallurgical Engineering SC Materials Science; Metallurgy & Metallurgical Engineering GA UC668 UT WOS:A1996UC66800014 ER PT J AU Warren, JA Murray, BT AF Warren, JA Murray, BT TI Ostwald ripening and coalescence of a binary alloy in two dimensions using a phase-field model SO MODELLING AND SIMULATION IN MATERIALS SCIENCE AND ENGINEERING LA English DT Article ID GROWTH AB A numerical study is made of the phenomena of Ostwald ripening in a two-dimensional binary alloy, using the phase-field model employed by Warren and Boettinger. Using this method we are able to trace the history of complicated dynamics driven by surface tension. Coalescence occurs in these systems without any special modification of the phase-field equations, and is observed over a wide range of volume fractions. The results describe an experimental regime which is far removed from the domain of applicability of classical (LSW) coarsening theory. In particular, the volume fraction (area fraction) changes by a large amount over the history of the simulation, resulting in substantial deviations from classical theory. C1 NIST,CTR THEORET & COMPUATAT MAT SCI,GAITHERSBURG,MD 20899. NIST,COMP & APPL MATH LAB,GAITHERSBURG,MD 20899. RP Warren, JA (reprint author), NIST,MAT SCI & ENGN LAB,GAITHERSBURG,MD 20899, USA. NR 28 TC 30 Z9 30 U1 1 U2 11 PU IOP PUBLISHING LTD PI BRISTOL PA TECHNO HOUSE, REDCLIFFE WAY, BRISTOL, ENGLAND BS1 6NX SN 0965-0393 J9 MODEL SIMUL MATER SC JI Model. Simul. Mater. Sci. Eng. PD MAR PY 1996 VL 4 IS 2 BP 215 EP 229 DI 10.1088/0965-0393/4/2/008 PG 15 WC Materials Science, Multidisciplinary; Physics, Applied SC Materials Science; Physics GA UM921 UT WOS:A1996UM92100008 ER PT J AU Paegle, J Mo, KC NoguesPaegle, J AF Paegle, J Mo, KC NoguesPaegle, J TI Dependence of simulated precipitation on surface evaporation during the 1993 United States summer floods SO MONTHLY WEATHER REVIEW LA English DT Article ID OSCILLATIONS; MODELS AB Regional summertime atmospheric conditions of 1993 are analyzed with the University of Utah Local Area Model (ULAM) by nudging boundary values and large internal scales of the local model toward values produced by the Nested Grid Model(NCEP/NOAA) initial analyses and forecasts archived at 6-h intervals. The approach allows the local ULAM to develop finer-scale structures in the precipitation and circulation forecasts than those resolved by the NGM. The study focuses on the influence of surface evaporation upon rainfall and low-level flow in regional simulations. Much of the rainfall simulated in the control experiment occurred from the late afternoon to early morning hours, with a pronounced midday minimum over the flood region. The moisture flux from the south due to the low-level jet (LLJ) provides much of the moisture source for the precipitation, and it is shown that the net moisture influx is significantly larger than the rainfall rate over the flood region. As a consequence, modifications of surface evaporation apparently are relatively more important in changing the buoyancy and resulting LLJ strength than they are in providing additional moisture to the already plentiful moisture influx from the Gulf of Mexico. This suggests that accurate surface evaporation in the Great Plains is necessary for accurate simulation of dynamic support for rainfall. The LLJ and especially its diurnal oscillation increase for drier surface conditions in the vicinity of the jet core, providing more effective convergence patterns to support rainfall in these cases than in cases of stronger surface evaporation. This appears to be a more important mechanism for rainfall release over the Mississippi River basin than moistening through local evapotranspiration, although the latter also contributes to more rainfall when this moistening occurs downwind of the jet core. C1 NOAA,NMC,CAC,WASHINGTON,DC. RP Paegle, J (reprint author), UNIV UTAH,DEPT METEOROL,819 WILLIAM BROWNING BLDG,SALT LAKE CITY,UT 84112, USA. NR 19 TC 87 Z9 89 U1 1 U2 6 PU AMER METEOROLOGICAL SOC PI BOSTON PA 45 BEACON ST, BOSTON, MA 02108-3693 SN 0027-0644 J9 MON WEATHER REV JI Mon. Weather Rev. PD MAR PY 1996 VL 124 IS 3 BP 345 EP 361 DI 10.1175/1520-0493(1996)124<0345:DOSPOS>2.0.CO;2 PG 17 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA UB903 UT WOS:A1996UB90300001 ER PT J AU Bond, NA Mass, CF Overland, JE AF Bond, NA Mass, CF Overland, JE TI Coastally trapped wind reversals along the United States west coast during the warm season .1. Climatology and temporal evolution SO MONTHLY WEATHER REVIEW LA English DT Article ID PACIFIC-NORTHWEST; MARINE AIR; DYNAMICS; AMERICA; REGION; EVENTS; LAYER; EDDY AB The northerly winds that predominate along the U.S. west coast during April-September are interrupted periodically by abrupt reversals to southerly flow. The climatology and composite temporal evolution of these reversals from Point Conception to the Canadian border are documented using hourly data from moored coastal buoys and Coastal-Marine Automated Network stations for the period 1981-91. The reversals are divided into two categories: coastally trapped reversals, in which the southerly flow is highly ageostrophic and restricted to the coastal zone, and synoptic reversals, which are associated with landfalling troughs or fronts. Coastally trapped events occur on average about 1.5 times per month along the central and northern California coast, about twice a month near the California-Oregon border, and about once a month near the Oregon-Washington border. The ratio of coastally trapped reversals to synoptic reversals is higher during July-September and lower during April-June, particularly in the north. Roughly one-quarter of the coastally trapped reversals have a southerly wind component that exceeds 5 m s(-1). Reversals along the California coast are gradual; the changes in the alongshore winds usually occur over a period of 6 h or longer, and the maximum southerlies are less than 8 m s(-1). In contrast, roughly one-half of the reversals north of the California-Oregon border feature abrupt changes with southerly winds reaching approximately 10-12 m s(-1) within 2-3 h of the wind shifts. These stronger northern events often include substantial decreases in air temperature and rises in pressure. The southerlies associated with coastally trapped reversals persist for an average of about 30 h at a particular location. There is a strong tendency for coastally trapped reversals to occur during the night or morning. North of Monterey Bay, the reversals typically advance poleward (but not necessarily in a smoothly continuous manner) at a mean speed of 7-8 m s(-1) and maintain significant amplitude for an alongshore distance of 500-1000 km. C1 UNIV WASHINGTON,JISAO,SEATTLE,WA 98195. UNIV WASHINGTON,DEPT ATMOSPHER SCI,SEATTLE,WA 98195. RP Bond, NA (reprint author), NOAA,PACIFIC MARINE ENVIRONM LAB,7600 SAND POINT WAY NE,SEATTLE,WA 98115, USA. NR 20 TC 47 Z9 47 U1 0 U2 0 PU AMER METEOROLOGICAL SOC PI BOSTON PA 45 BEACON ST, BOSTON, MA 02108-3693 SN 0027-0644 J9 MON WEATHER REV JI Mon. Weather Rev. PD MAR PY 1996 VL 124 IS 3 BP 430 EP 445 DI 10.1175/1520-0493(1996)124<0430:CTWRAT>2.0.CO;2 PG 16 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA UB903 UT WOS:A1996UB90300005 ER PT J AU Wilson, CL Grother, PJ Barnes, CS AF Wilson, CL Grother, PJ Barnes, CS TI Binary decision clustering for neural-network-based optical character recognition SO PATTERN RECOGNITION LA English DT Article DE OCR; neural networks; data clustering; pattern recognition; K-L transform; dynamic systems ID PATTERN-RECOGNITION; ARCHITECTURE AB A multiple neural network system for handprinted character recognition is presented. It consists of a set of input networks which discriminate between all two-class pairs, for example ''1'' from ''7'', and an output network which takes the signals from the input networks and yields a digit recognition decision. For a ten-digit classification problem this requires 45 binary decision machines in the input network. The output stage is typically a single trained network. The neural network paradigms adopted in these input and output networks are the multi-layer perceptron, the radial-bias function network and the probabilistic neural network. A simple majority vote rule was also tested in place of the output network. The various resulting digit classifiers were trained on 7480 isolated images and tested on a disjoint set of size 23140. The Karhunen-Loeve transforms of the images of each pair of two classes formed the training set for each BDM. Several different combinations of neural network input and output structures gave similar classification performance. The minimum error rate achieved was 2.5% with no rejection obtained by combining a PNN input array with an RBF output stage. This combined network had an error rate of 0.7% with 10% rejection. RP Wilson, CL (reprint author), NATL INST STAND & TECHNOL,COMP SYST LAB,GAITHERSBURG,MD 20899, USA. NR 41 TC 8 Z9 8 U1 0 U2 2 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD, ENGLAND OX5 1GB SN 0031-3203 J9 PATTERN RECOGN JI Pattern Recognit. PD MAR PY 1996 VL 29 IS 3 BP 425 EP 437 DI 10.1016/0031-3203(95)00105-0 PG 13 WC Computer Science, Artificial Intelligence; Engineering, Electrical & Electronic SC Computer Science; Engineering GA TZ944 UT WOS:A1996TZ94400007 ER PT J AU Suominen, KA Burnett, K Julienne, PS Walhout, M Sterr, U Orzel, C Hoogerland, M Rolston, SL AF Suominen, KA Burnett, K Julienne, PS Walhout, M Sterr, U Orzel, C Hoogerland, M Rolston, SL TI Ultracold collisions and optical shielding in metastable xenon SO PHYSICAL REVIEW A LA English DT Article ID LEVEL-CROSSINGS; WAVE; MOMENTUM; TRAPS AB Collisions between laser-cooled metastable xenon atoms in the presence of laser fields provide a good experimental test for ultracold collision theories as the observed ionization can be directly linked to the atomic binary collisions. Hyperfine structure is not present for the even isotopes Xe-132 and Xe-136, which simplifies the theoretical work. We present our results and show how these and the results presented in Walhout et al. [Phys. Rev. Lett, 74, 605 (1995)] can be interpreted with suitably adapted two-state models. Our approach suggests one possibility why the strong shielding of collisions predicted by the simple two-state model of Suominen et al. [Phys. Rev. A 51, 1446 (1995)] has not been achieved in the xenon experiment. C1 UNIV OXFORD,DEPT PHYS,CLARENDON LAB,OXFORD OX1 3PU,ENGLAND. NIST,DIV MOLEC PHYS,GAITHERSBURG,MD 20899. NIST,DIV ATOM PHYS,GAITHERSBURG,MD 20899. RI Suominen, Kalle-Antti/H-9076-2012; rolston, steven/L-5175-2013; Julienne, Paul/E-9378-2012 OI Suominen, Kalle-Antti/0000-0002-1091-2893; rolston, steven/0000-0003-1671-4190; Julienne, Paul/0000-0002-5494-1442 NR 27 TC 26 Z9 26 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 MAR PY 1996 VL 53 IS 3 BP 1678 EP 1689 DI 10.1103/PhysRevA.53.1678 PG 12 WC Optics; Physics, Atomic, Molecular & Chemical SC Optics; Physics GA TY087 UT WOS:A1996TY08700057 ER PT J AU Dowell, ML Hart, RC Gallagher, A Cooper, J AF Dowell, ML Hart, RC Gallagher, A Cooper, J TI Self-focused light propagation in a fully saturable medium: Experiment SO PHYSICAL REVIEW A LA English DT Article ID MULTIPLE CONICAL EMISSIONS; SODIUM VAPOR; BARIUM VAPOR; BEAMS; AMPLIFICATION; SIDEBANDS; SYSTEM AB We report observations of self-focusing and filamentation, i.e., the formation of one or more self-trapped beams, of similar to 3 ns laser pulses in strontium (Sr) vapor. The experimental arrangement consists of a Sr vapor cell and a pulsed neodymium-doped yttrium aluminum garnet pumped dye laser tuned to the blue of the 461 nm transition in Sr. The spatial intensity distribution of individual self-focused beams has been measured at the exit window of a vapor cell by using a magnifying lens and video camera. Measurements of power dependence, spatial distributions, and scaling behavior for filament formation are in good agreement with theory over a wide range of vapor densities, laser detunings, and laser powers. C1 NATL INST STAND & TECHNOL,BOULDER,CO 80309. RP Dowell, ML (reprint author), UNIV COLORADO,JOINT INST LAB ASTROPHYS,BOULDER,CO 80309, USA. NR 33 TC 32 Z9 33 U1 0 U2 1 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 1050-2947 J9 PHYS REV A JI Phys. Rev. A PD MAR PY 1996 VL 53 IS 3 BP 1775 EP 1781 DI 10.1103/PhysRevA.53.1775 PG 7 WC Optics; Physics, Atomic, Molecular & Chemical SC Optics; Physics GA TY087 UT WOS:A1996TY08700068 ER PT J AU Martin, WC Sugar, J AF Martin, WC Sugar, J TI Designations of ds(2)p energy levels in neutral zirconium, hafnium, and rutherfordium (Z=104) SO PHYSICAL REVIEW A LA English DT Article ID ELEMENT; ATOMS AB We have examined available data for the odd-parity energy-level structures in Zr and Hf, stimulated by the designations of four predicted 6d7s(2)7p levels in the homologous atom rutherfordium (Rf, Z=104) by Eliav et al. [Phys. Rev. Lett. 74, 1079 (1995)]. We point out some errors and deficiencies in the Zr data and give the results of Hartree-Fock calculations for Hf 5d6s(2)6p and Rf 6d7s(2)7p levels. Configuration interactions within the (d+s)(3)p complexes were included. The resulting eigenvectors allow meaningful LS-coupling designations for most of the levels belonging mainly to Hf 5d6s(2)6p and for most of the predicted Rf levels belonging mainly to 6d7s(2)7p. Some changes in the designations assigned to these levels in the literature are suggested: in particular, the lowest level of both Hf 5d6s26p and Rf 6d7s27p is most appropriately designated F-3(2)0. We point out the need for systematic whole-row studies of the low odd-parity configurations in 4d- and 5d-shell spectra. RP Martin, WC (reprint author), NATL INST STAND & TECHNOL,GAITHERSBURG,MD 20899, USA. NR 20 TC 16 Z9 16 U1 0 U2 0 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 1050-2947 J9 PHYS REV A JI Phys. Rev. A PD MAR PY 1996 VL 53 IS 3 BP 1911 EP 1914 DI 10.1103/PhysRevA.53.1911 PG 4 WC Optics; Physics, Atomic, Molecular & Chemical SC Optics; Physics GA TY087 UT WOS:A1996TY08700086 ER PT J AU Guo, J Arimondo, E AF Guo, J Arimondo, E TI Laser cooling of Rydberg atoms in bichromatic standing waves SO PHYSICAL REVIEW A LA English DT Article AB We present a calculation of cooling of Rydberg atoms in bichromatic standing light waves. The atoms in our model are assumed to have a cascade three-level transition scheme, with the second excited level being the Rydberg state. The cooling fields, which also excite the atoms to the Rydberg state, consist of two standing waves whose frequencies are tuned near the two transition frequencies of the cascade atomic system. It is shown that the mechanisms of Sisyphus cooling and velocity-selective coherent population trapping can co-exist in such a configuration, and under certain conditions the majority of the laser-cooled atoms are in the Rydberg state. C1 NATL INST STAND & TECHNOL,BOULDER,CO 80309. UNIV PISA,DIPARTIMENTO FIS,I-56126 PISA,ITALY. RP Guo, J (reprint author), UNIV COLORADO,JOINT INST LAB ASTROPHYS,BOULDER,CO 80309, USA. NR 10 TC 6 Z9 6 U1 0 U2 0 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 1050-2947 J9 PHYS REV A JI Phys. Rev. A PD MAR PY 1996 VL 53 IS 3 BP R1224 EP R1227 PG 4 WC Optics; Physics, Atomic, Molecular & Chemical SC Optics; Physics GA TY087 UT WOS:A1996TY08700006 ER PT J AU Suominen, KA Burnett, K Julienne, PS AF Suominen, KA Burnett, K Julienne, PS TI Role of off-resonant excitation in cold collisions in a strong laser field SO PHYSICAL REVIEW A LA English DT Article AB We have studied how the presence of a strongly coupled off-resonant molecular potential affects cold collisions in a laser field. To do this, we have performed a fully quantal time-dependent three-state calculation that includes both spontaneous emission and laser-driven dynamics of the collision complex. Our results show that although the presence:of the off-resonant state has an effect on the collision process, two-state calculations will be valid unless the Rabi coupling greatly exceeds the detuning. We have investigated how this physics impinges on trap loss and optical shielding in a magneto-optical trap. Our results indicate that the experimentally observed saturation of optical shielding cannot be explained adequately by off-resonant effects. C1 NIST,ATOM PHYS DIV,GAITHERSBURG,MD 20899. UNIV OXFORD,DEPT PHYS,CLARENDON LAB,OXFORD OX1 3PU,ENGLAND. RP Suominen, KA (reprint author), HELSINKI UNIV,DEPT PHYS,DIV THEORET PHYS,PL 9,SF-00014 HELSINKI,FINLAND. RI Suominen, Kalle-Antti/H-9076-2012; Julienne, Paul/E-9378-2012 OI Suominen, Kalle-Antti/0000-0002-1091-2893; Julienne, Paul/0000-0002-5494-1442 NR 22 TC 6 Z9 6 U1 0 U2 0 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 1050-2947 J9 PHYS REV A JI Phys. Rev. A PD MAR PY 1996 VL 53 IS 3 BP R1220 EP R1223 PG 4 WC Optics; Physics, Atomic, Molecular & Chemical SC Optics; Physics GA TY087 UT WOS:A1996TY08700005 ER PT J AU Yildirim, T Harris, AB Shender, EF AF Yildirim, T Harris, AB Shender, EF TI Three-dimensional ordering in bct antiferromagnets due to quantum disorder SO PHYSICAL REVIEW B LA English DT Article ID KAGOME-LATTICE; TETRAGONAL ANTIFERROMAGNETS; RANGE ORDER; FLUCTUATIONS; FERROMAGNET; FRUSTRATION; EXCHANGE AB Quantum effects on magnetic ordering in body-centered-tetragonal antiferromagnets with only nearest-neighbor interactions are studied in detail using interacting spin-wave theory. The model consists of M noninteracting (in a mean-field sense) antiferromagnetic planes which together form a body-centered-tetragonal structure. We obtain the leading quantum correction of order 1/S from the zero-point energy for a system of M planes whose staggered moments have arbitrary orientations. The infinite degeneracy of the ground-state manifold of this system is partially removed by collinear ordering in view of effects previously calculated by Shender at relative order J(perpendicular to)(2)(J(2)S), where J, the antiferroma,gnetic in-plane exchange interaction, is assumed to dominate J(perpendicular to), the out-of-plane interaction which can be of either sign. We study the complete removal of the remaining degeneracy of the collinear spin structures by assigning an arbitrary sign sigma(i) (i=1,2,...M) to the staggered moment of the planes. Our result for the zero-point energy (for M>2) up to the sixth order in j=J(perpendicular to)/J is [GRAPHICS] where C>0 and E(1) are constants independent of the sigma's, and E(G) is the classical ground-state energy. (Here sums from i to j when j4 second-neighboring planes are antiferromagnetically coupled in the ground state and thus the three-dimensional spin structure cannot be described by a single wave vector, as is often assumed. At order j(4), sigma-dependent terms first appear at order 1/S-3 and these also favor antiferromagnetic coupling of alternate planes. C1 NATL INST STAND & TECHNOL,GAITHERSBURG,MD 20899. UNIV PENN,DEPT PHYS,PHILADELPHIA,PA 19104. UNIV OXFORD,OXFORD OX2 3NP,ENGLAND. TEL AVIV UNIV,RAYMOND & BEVERLY SACKLER INST EXACT SCI,SCH PHYS & ASTRON,IL-69978 TEL AVIV,ISRAEL. INST PHYS NUCL,ST PETERSBURG,RUSSIA. UNIV CALIF BERKELEY,DEPT PHYS,BERKELEY,CA 94720. RP Yildirim, T (reprint author), UNIV MARYLAND,COLLEGE PK,MD 20742, USA. RI yildirim, taner/A-1290-2009; harris, A Brooks/C-8640-2013 NR 37 TC 21 Z9 21 U1 0 U2 3 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 0163-1829 J9 PHYS REV B JI Phys. Rev. B PD MAR 1 PY 1996 VL 53 IS 10 BP 6455 EP 6476 DI 10.1103/PhysRevB.53.6455 PG 22 WC Physics, Condensed Matter SC Physics GA TZ773 UT WOS:A1996TZ77300061 ER PT J AU Cooley, LD Lee, PJ Larbalestier, DC AF Cooley, LD Lee, PJ Larbalestier, DC TI Flux-pinning mechanism of proximity-coupled planar defects in conventional superconductors: Evidence that magnetic pinning is the dominant pinning mechanism in niobium-titanium alloy SO PHYSICAL REVIEW B LA English DT Article ID FINAL OPTIMIZATION STRAIN; CRITICAL CURRENT-DENSITY; NB-TI SUPERCONDUCTOR; II SUPERCONDUCTORS; QUANTITATIVE DESCRIPTION; CRITICAL FIELDS; SCALING LAWS; VORTICES; SURFACE; FORCE AB We propose that a magnetic pinning mechanism is the dominant flux-pinning mechanism of proximity-coupled, planar defects when the field is parallel to the defect. We find compelling evidence that this pinning mechanism is responsible for the strong flux-pinning force exerted by ribbon-shaped alpha-Ti precipitates and artificial pins in Nb-Ti superconductors, instead of the core pinning mechanism as has been hitherto widely believed. Because the elementary pinning force f(p)(H) is nonmonotonic when it is optimum (i.e., when the defect thickness t and the proximity length xi(N) have comparable dimensions), the total pinning force F-p(H) generally does not show temperature scaling. Characteristic changes in the magnitude and shape of F-p(H) at constant T but at different t/xi(N) (e.g., different Nb-Ti wire diameters) are also direct consequences of the pinning mechanism. The optimum flux-pinning state is a compromise between maximizing f(p) and getting the highest number density of pins. For a given defect composition this state is reached when t similar to xi(N)/3, while for varying defect composition the peak F-p gets higher when xi(N) is made shorter. Artificial pinning center Nb-Ti wires having short xi(N) pins appear to be vital for obtaining high J(c) at high fields because only then is the elementary pinning force optimized at small pin thicknesses which permit a high number density of vortex-pin interactions and a large bulk pinning force. We find verification of our predictions in experimental F-p(H, T,t) data obtained on special laboratory-scale artificial pinning-center Nb-Ti wires. C1 UNIV WISCONSIN,CTR APPL SUPERCONDUCT,MADISON,WI 53706. UNIV WISCONSIN,DEPT MAT SCI & ENGN,MADISON,WI 53706. UNIV WISCONSIN,DEPT PHYS,MADISON,WI 53706. RP Cooley, LD (reprint author), NATL INST STAND & TECHNOL,DIV ELECTROMAGNET TECHNOL,325 BROADWAY,BOULDER,CO 80303, USA. RI Larbalestier, David/B-2277-2008; Cooley, Lance/E-7377-2015; OI Larbalestier, David/0000-0001-7098-7208; Cooley, Lance/0000-0003-3488-2980; Lee, Peter/0000-0002-8849-8995 NR 70 TC 41 Z9 41 U1 0 U2 8 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 0163-1829 J9 PHYS REV B JI Phys. Rev. B PD MAR 1 PY 1996 VL 53 IS 10 BP 6638 EP 6652 DI 10.1103/PhysRevB.53.6638 PG 15 WC Physics, Condensed Matter SC Physics GA TZ773 UT WOS:A1996TZ77300083 ER PT J AU Wilson, SP Coakley, KJ AF Wilson, SP Coakley, KJ TI Estimation of asymmetry in physics SO PHYSICAL REVIEW E LA English DT Article ID SCATTERING; STATISTICS AB The notion of asymmetry arises in many physical experiments, being a natural expression of the relative difference between two quantities. In this paper, we discuss the estimation of asymmetries between the rates of two event processes subject to a common background. Such asymmetries have many applications in solid-state physics-a measurement of the difference in arrival rates of electrons with one of two possible spin orientations to a detector, for example. We describe three techniques for estimating asymmetries from observations subject to uncertainty: a naive method based on an unbiased estimate and a Gaussian approximation, a bootstrap approach, and a Bayesian approach. Differences in the interpretation of the estimates are discussed and their performances are compared by means of a simulation study. The aim is both to review the methodology on estimation of asymmetries and to contribute to the more general discussion of the relative merits of frequentist and Bayesian inference. C1 NATL INST STAND & TECHNOL,BOULDER,CO 80303. RP Wilson, SP (reprint author), UNIV DUBLIN TRINITY COLL,DEPT STAT,DUBLIN 2,IRELAND. OI Wilson, Simon/0000-0003-0312-3586 NR 14 TC 2 Z9 2 U1 0 U2 3 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 1063-651X J9 PHYS REV E JI Phys. Rev. E PD MAR PY 1996 VL 53 IS 3 BP 2160 EP 2168 DI 10.1103/PhysRevE.53.2160 PG 9 WC Physics, Fluids & Plasmas; Physics, Mathematical SC Physics GA UA371 UT WOS:A1996UA37100026 ER PT J AU vanZanten, JH Wallace, WE Wu, WL AF vanZanten, JH Wallace, WE Wu, WL TI Effect of strongly favorable substrate interactions on the thermal properties of ultrathin polymer films SO PHYSICAL REVIEW E LA English DT Article ID GLASS-TRANSITION AB The thermal behavior of ultrathin films of poly-(2)-vinylpyridine spin-cast on acid-cleaned silicon oxide substrates is considered. The interaction between the polymer and the substrate is polar in nature and very favorable. As a means of examining the thermal properties of the films, x-ray reflectivity is used to measure the temperature dependence of the film thickness. This experimentally measured thickness-temperature data is used to determine transition temperatures and thermal expansivities. Significantly increased transition temperatures (20-50 degrees C above the measured bulk glass transition temperature) are observed in ultrathin polymer films. The transition temperature increases with decreasing film thickness, while the degree of thermal expansion below the transition temperature decreases with decreasing film thickness. If one assumes that a region of reduced chain mobility exists near the solid substrate-polymer interface, an analysis of the measured thermal expansion behavior below the transition temperature indicates that the length scale of substrate interactions is on the order of the macromolecular size. C1 NIST,DIV POLYMERS,MAT SCI & ENGN LAB,GAITHERSBURG,MD 20899. RP vanZanten, JH (reprint author), JOHNS HOPKINS UNIV,DEPT CHEM ENGN,3400 N CHARLES ST,BALTIMORE,MD 21218, USA. NR 21 TC 377 Z9 377 U1 6 U2 41 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 MAR PY 1996 VL 53 IS 3 BP R2053 EP R2056 PG 4 WC Physics, Fluids & Plasmas; Physics, Mathematical SC Physics GA UA371 UT WOS:A1996UA37100010 ER PT J AU Kovacs, A Wojnarovits, L McLaughlin, WL Eid, SEE Miller, A AF Kovacs, A Wojnarovits, L McLaughlin, WL Eid, SEE Miller, A TI Radiation-chemical reaction of 2,3,5-triphenyl-tetrazolium chloride in liquid and solid state SO RADIATION PHYSICS AND CHEMISTRY LA English DT Article; Proceedings Paper CT 8th Tihany Symposium on Radiation Chemistry CY 1994 CL BALATONSZEPLAK, HUNGARY ID TETRAZOLIUM SALTS; RADIOLYSIS AB In pulse radiolysis of 2,3,5-triphenyl-tetrazolium chloride (TTC) at around 360 nm fast formation of intermediate tetrazolium radical was observed under both oxidizing and reducing conditions. In the latter case bimolecular formation of formazan, absorbing at around 480 nm, was observed. This reaction is accompanied by combination to the diformazan dimer, absorbing over the spectral range 500-550 nm. A polyvinyl-alcohol-based TTC film was produced and tested for dosimetry purposes: it gave a measurable response in the 1-100 kGy dose range by evaluating the 50 mu m thick TTC films at the absorption maximum of 493 nm. C1 NIST,PHYS LAB,GAITHERSBURG,MD 20899. NATL CTR RADIAT RES & TECHNOL,CAIRO,EGYPT. RISO NATL LAB,HIGH DOSE REFERENCE LAB,DK-4000 ROSKILDE,DENMARK. RP Kovacs, A (reprint author), HUNGARIAN ACAD SCI,INST ISOTOPES,POB 77,H-1525 BUDAPEST,HUNGARY. NR 11 TC 25 Z9 25 U1 0 U2 0 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 MAR PY 1996 VL 47 IS 3 BP 483 EP 486 DI 10.1016/0969-806X(95)00144-M PG 4 WC Chemistry, Physical; Nuclear Science & Technology; Physics, Atomic, Molecular & Chemical SC Chemistry; Nuclear Science & Technology; Physics GA TN378 UT WOS:A1996TN37800037 ER PT J AU Stephens, EF Patrick, H Gilbert, SL AF Stephens, EF Patrick, H Gilbert, SL TI Electronically tunable fiber laser for optical pumping of He-3 and He-4 SO REVIEW OF SCIENTIFIC INSTRUMENTS LA English DT Article ID BRAGG GRATINGS; TRANSITION; SR+ AB We present in this paper a low threshold, highly stable, integrated fiber laser cavity that uses an electronically tunable internal Bragg grating. The fiber laser produced over 5 mW with a spectral width of about 5 GHz at 1083 nm. The laser was used to achieve 30% polarization of the 2 S-3(1) metastable states of He-4 in a weak rf discharge cell. (C) 1996 American Institute of Physics. C1 NATL INST STAND & TECHNOL,BOULDER,CO 80303. RP Stephens, EF (reprint author), UNIV MISSOURI,DEPT PHYS,ROLLA,MO 65401, USA. NR 14 TC 0 Z9 0 U1 0 U2 1 PU AMER INST PHYSICS PI WOODBURY PA CIRCULATION FULFILLMENT DIV, 500 SUNNYSIDE BLVD, WOODBURY, NY 11797-2999 SN 0034-6748 J9 REV SCI INSTRUM JI Rev. Sci. Instrum. PD MAR PY 1996 VL 67 IS 3 BP 843 EP 844 DI 10.1063/1.1146821 PN 1 PG 2 WC Instruments & Instrumentation; Physics, Applied SC Instruments & Instrumentation; Physics GA UA057 UT WOS:A1996UA05700041 ER PT J AU Seiler, DG AF Seiler, DG TI Fear of physics SO SCIENCES-NEW YORK LA English DT Letter RP Seiler, DG (reprint author), NATL INST STAND & TECHNOL,GAITHERSBURG,MD 20899, USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU NEW YORK ACAD SCIENCES PI NEW YORK PA 2 E 63RD ST, NEW YORK, NY 10021 SN 0036-861X J9 SCIENCES JI Sci.-New York PD MAR-APR PY 1996 VL 36 IS 2 BP 48 EP 48 PG 1 WC Multidisciplinary Sciences SC Science & Technology - Other Topics GA TX286 UT WOS:A1996TX28600020 ER PT J AU Diodati, PJ Richards, RA AF Diodati, PJ Richards, RA TI Mortality of striped bass hooked and released in salt water SO TRANSACTIONS OF THE AMERICAN FISHERIES SOCIETY LA English DT Article AB Despite the importance of the recreational fishery for striped bass Morone saxatilis along the eastern coast of the United States, little is known about the survival rates of caught and released striped bass. We predicted long-term (58-d) hooking mortality of striped bass after catch and release in saltwater using a logistic regression model. Experimental fishing was conducted on fish (27-57 cm) in a 2-ha saltwater impoundment in Salem, Massachusetts. Depth of hook pen etration in the oral cavity, anatomical site of hooking, gear type (treble or single hooks), and angler experience were significantly related to mortality (P < 0.05). The logistic regression model was developed with backwards stepwise selection to predict probability of death from hooking. The final model included depth of hook penetration, gear type, and angler experience as predictor variables. Predicted mortality ranged from 3% under the most favorable conditions to 26% for the worst set of conditions. Predicted as well as observed mortality for the entire experimental group was 9% which is generally much lower than reported in striped bass hooking mortality studies conducted in freshwater. At the end of the experiment, condition factors were significantly lower for surviving hooked fish than for fish that had not been hooked. C1 NATL MARINE FISHERIES SERV, NE FISHERIES SCI CTR, WOODS HOLE, MA 02543 USA. RP Diodati, PJ (reprint author), MASSACHUSETTS DIV MARINE FISHERIES, CAT COVE MARINE LAB, SALEM, MA 01970 USA. NR 22 TC 46 Z9 48 U1 0 U2 7 PU TAYLOR & FRANCIS INC PI PHILADELPHIA PA 530 WALNUT STREET, STE 850, PHILADELPHIA, PA 19106 USA SN 0002-8487 EI 1548-8659 J9 T AM FISH SOC JI Trans. Am. Fish. Soc. PD MAR PY 1996 VL 125 IS 2 BP 300 EP 307 DI 10.1577/1548-8659(1996)125<0300:MOSBHA>2.3.CO;2 PG 8 WC Fisheries SC Fisheries GA UA766 UT WOS:A1996UA76600016 ER PT J AU Maynard, DJ Frost, DA Waknitz, FW Prentice, EF AF Maynard, DJ Frost, DA Waknitz, FW Prentice, EF TI Vulnerability of marked age-0 steelhead to a visual predator SO TRANSACTIONS OF THE AMERICAN FISHERIES SOCIETY LA English DT Article ID JUVENILE; MORTALITY; FISHES AB The assumption that marking does not alter the vulnerability of fish to a visual predator was examined. Similar numbers of age-0 steelhead Oncorhynchus mykiss were tagged with binary-coded-wires, tagged with passive integrated transponders, freeze branded, marked with fingerling tags, or left unmarked. All were subjected to age-1 steelhead predators for 24 h in 2.4-m-diameter circular tanks filled with clear well water. Twice as many marked as unmarked age-0 steel-head prey were eaten. There was no significant survival difference among the four marked treatment groups, which suggested that in the laboratory the trauma associated with marking is more important than mark type. We conclude that marking may effect postrelease survival and recommend that mark-recapture experiments be used to empirically determine and correct for differences in survival of marked and unmarked fish. RP Maynard, DJ (reprint author), NOAA,NATL MARINE FISHERIES SERV,NW FISHERIES SCI CTR,COASTAL ZONE & ESTUARINE STUDIES DIV,SEATTLE,WA 98112, USA. NR 22 TC 7 Z9 8 U1 1 U2 4 PU AMER FISHERIES SOC PI BETHESDA PA 5410 GROSVENOR LANE SUITE 110, BETHESDA, MD 20814-2199 SN 0002-8487 J9 T AM FISH SOC JI Trans. Am. Fish. Soc. PD MAR PY 1996 VL 125 IS 2 BP 330 EP 333 DI 10.1577/1548-8659(1996)125<0330:VOMAST>2.3.CO;2 PG 4 WC Fisheries SC Fisheries GA UA766 UT WOS:A1996UA76600020 ER PT J AU Milly, PCD AF Milly, PCD TI Effects of thermal vapor diffusion on seasonal dynamics of water in the unsaturated zone SO WATER RESOURCES RESEARCH LA English DT Article ID DESERT SOILS; EVAPORATION; TRITIUM; TRACERS; LIQUID AB The response of water in the unsaturated zone to seasonal changes of temperature (T) is determined analytically using the theory of nonisothermal water transport in porous media, and the solutions are tested against field observations of moisture potential and bomb fallout isotopic (Cl-36 and H-3) concentrations. Seasonally varying land surface temperatures and the resulting subsurface temperature gradients induce thermal vapor diffusion. The annual mean vertical temperature gradient is close to zero; however, the annual mean thermal vapor flux is downward, because the temperature-dependent vapor diffusion coefficient is larger, on average, during downward diffusion (occurring at high T) than during upward diffusion (low T). The annual mean thermal vapor flux is shown to decay exponentially with depth; the depth (about 1 m) at which it decays to e(-1) of its surface value is one half of the corresponding decay depth for the amplitude of seasonal temperature changes; This depth-dependent annual mean flux is effectively a source of water, which must be balanced by a flux divergence associated with other transport processes. In a relatively humid environment the liquid fluxes greatly exceed the thermal vapor fluxes, so such a balance is readily achieved without measurable effect on the dynamics of water in the unsaturated zone. However, if the mean vertical water flux through the unsaturated zone is very small (<1 mm y(-1)), as it may be at many locations in a desert landscape, the thermal vapor flux must be balanced mostly by a matric-potential-induced upward flux of water. This return flux may include both vapor and liquid components. Below any near-surface zone of weather-related fluctuations of matric potential, maintenance of this upward flux requires an increase with depth in the annual mean matric potential; this theoretical prediction is supported by long-term field measurements in the Chihuahuan Desert. The analysis also makes predictions, confirmed by the field observations, regarding the seasonal variations of matric potential at a given depth. The conceptual model of unsaturated zone water transport developed here implies the possibility of near-surface trapping of any aqueous constituent introduced at the surface. RP Milly, PCD (reprint author), US GEOL SURVEY,NOAA,GEOPHYS FLUID DYNAM LAB,POB 308,PRINCETON,NJ 08542, USA. NR 24 TC 10 Z9 12 U1 1 U2 2 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 MAR PY 1996 VL 32 IS 3 BP 509 EP 518 DI 10.1029/95WR03489 PG 10 WC Environmental Sciences; Limnology; Water Resources SC Environmental Sciences & Ecology; Marine & Freshwater Biology; Water Resources GA TX708 UT WOS:A1996TX70800002 ER PT J AU Seo, DJ Smith, JA AF Seo, DJ Smith, JA TI On the relationship between catchment scale and climatological variability of surface-runoff volume SO WATER RESOURCES RESEARCH LA English DT Article ID WATER-BALANCE; VEGETATION; CLIMATE; SOIL AB The relationship between catchment scale and climatological variability of surface-runoff volume is evaluated through theoretical and empirical analyses. Using a point description of surface-runoff volume following infiltration excess under the time compression approximation, climatological mean and variance of areal runoff volume over heterogeneous soil are evaluated by integrating second-order statistics pf point runoff volume. Second-order statistics of rainfall duration and intensity, required for evaluation of those of point runoff volume, are obtained from mean and variance of areal rainfall volume under fractional coverage considerations. Hourly Weather Surveillance Radar-1988 Doppler rainfall data were used to estimate rainfall parameters following a set of simplifying assumptions on the space-time correlation structure. Two contrasting climate-soil systems were considered in specifying soil and soil moisture parameters following a set of assumptions on spatial variability and interdependency of the soil parameters. C1 PRINCETON UNIV,DEPT CIVIL ENGN & OPERAT RES,PRINCETON,NJ 08544. RP Seo, DJ (reprint author), NATL WEATHER SERV,HYDROL RES LAB,1325 EAST WEST HIGHWAY,SILVER SPRING,MD 20910, USA. NR 15 TC 8 Z9 8 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 MAR PY 1996 VL 32 IS 3 BP 633 EP 643 DI 10.1029/95WR03641 PG 11 WC Environmental Sciences; Limnology; Water Resources SC Environmental Sciences & Ecology; Marine & Freshwater Biology; Water Resources GA TX708 UT WOS:A1996TX70800012 ER PT J AU Vizintin, J Kalin, M Novak, S Drazic, G Ives, LK Peterson, MB AF Vizintin, J Kalin, M Novak, S Drazic, G Ives, LK Peterson, MB TI Effect of slip amplitude on the fretting wear of silicon nitride against silicon nitride SO WEAR LA English DT Article DE fretting; wear; silicon nitride; amplitude; time ID FRICTION AB The fretting wear behaviour of silicon nitride against silicon nitride was investigated under lubricated conditions as a function of fretting amplitude and duration. Amplitudes in the intermediate 5-50 mu m range and test durations from 10 to 360 min were studied, using the commercial lubricant ISO VG 220. Light microscopy, scanning electron microscopy, transmission electron microscopy and energy dispersive X-ray spectroscopy were employed to determine the detailed nature of the friction and wear processes. Different wear mechanisms were observed, depending on time and amplitude. C1 UNIV LJUBLJANA,JOZEF STEFAN INST,LJUBLJANA 61000,SLOVENIA. NATL INST STAND & TECHNOL,GAITHERSBURG,MD 20899. RP Vizintin, J (reprint author), UNIV LJUBLJANA,FAC MECH ENGN,LJUBLJANA 61000,SLOVENIA. RI Drazic, Goran/A-2017-2008; kalin, mitjan/M-2504-2014 OI Drazic, Goran/0000-0001-7809-8050; NR 14 TC 19 Z9 19 U1 1 U2 5 PU ELSEVIER SCIENCE SA LAUSANNE PI LAUSANNE 1 PA PO BOX 564, 1001 LAUSANNE 1, SWITZERLAND SN 0043-1648 J9 WEAR JI Wear PD MAR PY 1996 VL 192 IS 1-2 BP 11 EP 20 DI 10.1016/0043-1648(95)06742-6 PG 10 WC Engineering, Mechanical; Materials Science, Multidisciplinary SC Engineering; Materials Science GA UJ062 UT WOS:A1996UJ06200003 ER PT J AU Xu, HHK Jahanmir, S AF Xu, HHK Jahanmir, S TI Transitions in the mechanism of material removal in abrasive wear of alumina SO WEAR LA English DT Article DE abrasive wear; alumina; grain dislodgement; lateral crack chipping; material removal; scratching; wear transition ID STRENGTH; CERAMICS AB The mechanisms of material removal in abrasive wear are investigated by scratching a fine grain alumina with a diamond indenter. Subsurface damage is examined as a Function of load and number of passes using a bonded-interface sectioning technique together with microscopy. Scratching produces classical lateral and median cracks extending from the plastic zone beneath the contact area. Damage within the plastic zone is distributed in nature taking the form of intragrain twin/slip bands and intergranular microcracks. Repeated scratching causes damage accumulation in the material beneath the sliding contact area. After a critical number of passes, a transition is observed from a damage accumulation process to a material removal process that involves mainly grain dislodgement. As the number of passes is increased at large loads, the removal process exhibits a second transition from grain dislodgement to a more severe wear process by lateral crack chipping. RP Xu, HHK (reprint author), NATL INST STAND & TECHNOL,GAITHERSBURG,MD 20899, USA. NR 21 TC 26 Z9 27 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 MAR PY 1996 VL 192 IS 1-2 BP 228 EP 232 DI 10.1016/0043-1648(95)06736-1 PG 5 WC Engineering, Mechanical; Materials Science, Multidisciplinary SC Engineering; Materials Science GA UJ062 UT WOS:A1996UJ06200029 ER PT J AU Stensrud, DJ Skindlov, JA AF Stensrud, DJ Skindlov, JA TI Gridpoint predictions of high temperature from a mesoscale model SO WEATHER AND FORECASTING LA English DT Article ID 4-DIMENSIONAL DATA ASSIMILATION; STEP-MOUNTAIN COORDINATE; PLANETARY BOUNDARY-LAYER; PARAMETERIZATION; RESOLUTION AB Mesoscale model gridpoint temperature data from simulations in the southwestern United States during the summer of 1990 are compared with both observations and statistical guidance from large-scale models over a 32-day period. Although the raw model temperature data at the lowest sigma level typically are much lower than observed, when the mean temperature bias is removed, the model values of high temperature compare favorably with both observations and operational statistical guidance products. A simple 7-day running mean bias calculation that could be used in an operational environment is tested and also found to produce good results. These comparisons suggest that the ability of mesoscale model gridpoint data to produce useful and accurate forecast products through the use of very simple bias corrections should be explored fully as mesoscale model data become routinely available. C1 SALT RIVER PROJECT,PHOENIX,AZ. RP Stensrud, DJ (reprint author), NOAA,NATL SEVERE STORMS LAB,ERL,1313 HALLEY CIRCLE,NORMAN,OK 73069, USA. NR 30 TC 24 Z9 25 U1 1 U2 1 PU AMER METEOROLOGICAL SOC PI BOSTON PA 45 BEACON ST, BOSTON, MA 02108-3693 SN 0882-8156 J9 WEATHER FORECAST JI Weather Forecast. PD MAR PY 1996 VL 11 IS 1 BP 103 EP 110 DI 10.1175/1520-0434(1996)011<0103:GPOHTF>2.0.CO;2 PG 8 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA UA769 UT WOS:A1996UA76900009 ER PT J AU Draxler, RR AF Draxler, RR TI Trajectory optimization for balloon flight planning SO WEATHER AND FORECASTING LA English DT Article AB The recent solo transpacific balloon flight was used as a test case to evaluate multiple trajectory techniques to select different pathways based upon potential variations in balloon altitudes. Altitude changes between 3 and 8 km above ground resulted in predicted ending locations varying from the Hawaiian Islands to the Atlantic coast, after five days' travel. The method can be used to select optimum flight altitudes based upon forecast meteorological fields. RP Draxler, RR (reprint author), NOAA,AIR RESOURCES LAB,SILVER SPRING,MD 20910, USA. NR 5 TC 29 Z9 33 U1 0 U2 1 PU AMER METEOROLOGICAL SOC PI BOSTON PA 45 BEACON ST, BOSTON, MA 02108-3693 SN 0882-8156 J9 WEATHER FORECAST JI Weather Forecast. PD MAR PY 1996 VL 11 IS 1 BP 111 EP 114 DI 10.1175/1520-0434(1996)011<0111:TOFBFP>2.0.CO;2 PG 4 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA UA769 UT WOS:A1996UA76900010 ER PT J AU Stewart, SR Lyons, SW AF Stewart, SR Lyons, SW TI A WSR-88D radar view of tropical cyclone Ed SO WEATHER AND FORECASTING LA English DT Article ID CONVECTIVE-SCALE CHARACTERISTICS; INNER CORE STRUCTURE; MATURE HURRICANES; MESOSCALE; ALICIA AB The Guam WSR-88D (Weather Surveillance Radar-1988 Doppler) Doppler radar collected reflectivity, Doppler radial velocity, and other information for Supertyphoon Ed as it traversed the northern sections of Guam as a minimal tropical storm on 30 September 1993. This was the first-ever recorded passage of a tropical cyclone over a Next Generation Weather Radar WSR-88D Doppler radar site. Reflectivity data provided valuable information about the location of a precipitation-free ''eye,'' while radial velocity data provided useful information about tropical cyclone wind center location and strength. The velocity data also provided a 3-h lead time to upgrade the tropical cyclone to tropical storm intensity prior to landfall. Forecasters at Andersen Air Force Base used this information to give what turned out to be a very accurate short-range forecast of a brief period of gales with maximum gusts to 26 m s(-1). Land-based surface wind observations correlated extremely well with 75%-80% of the 1500-m radial velocity estimates, which is similar to findings made by Powell and Tanner et al. Additional radar signatures of interest include offsets between the reflectivity center and velocity circulation center, detection of tropical storm and typhoon/hurricane force winds, Doppler velocity maxima within the convective rainbands, and mesocyclonic circulations detected by the WSR-88D's mesocyclone algorithm. Concerning mesocyclones, one was detected very close to the location of the actual wind center when Ed was developing an eye prior to landfall. Within approximately 1 h of initial mesocyclone occurrence, a cyclonic divergent velocity-coupler pattern formed, possibly due to the development of low-level supergradient winds. The observed Doppler velocity patterns were consistent with the lower-tropospheric horizontal wind and vertical motion patterns in and around the eye as described by Malkus, Kuo, and Gray and Shea. After clearing the west coast of Guam, two separate mesocyclones formed just inward of the eyewall and appeared to be ingested into the main eye circulation. Similar findings were obtained from airborne Doppler radar analyses made by Marks and Houze. Shortly thereafter, Ed underwent a period of rapid intensification. In both instances, the mesocyclones appeared to have played a role in eye development and intensification. C1 NATL HURRICANE CTR,MIAMI,FL. RP Stewart, SR (reprint author), OPERAT SUPPORT FACIL,3200 MARSHALL AVE,WSR-88D,NORMAN,OK 73069, USA. NR 28 TC 20 Z9 20 U1 0 U2 1 PU AMER METEOROLOGICAL SOC PI BOSTON PA 45 BEACON ST, BOSTON, MA 02108-3693 SN 0882-8156 J9 WEATHER FORECAST JI Weather Forecast. PD MAR PY 1996 VL 11 IS 1 BP 115 EP 135 DI 10.1175/1520-0434(1996)011<0115:AWRVOT>2.0.CO;2 PG 21 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA UA769 UT WOS:A1996UA76900011 ER PT J AU Schiffman, A Chapman, WB Nesbitt, DJ AF Schiffman, A Chapman, WB Nesbitt, DJ TI State-to-state, rotational energy-transfer dynamics in crossed supersonic jets: A high-resolution IR absorption method SO JOURNAL OF PHYSICAL CHEMISTRY LA English DT Article ID INFRARED DOUBLE-RESONANCE; PUMP-PROBE MEASUREMENTS; TUNABLE DIODE-LASER; INELASTIC-SCATTERING; ANISOTROPIC INTERACTION; SPECTRAL INTENSITIES; FUNDAMENTAL BANDS; TRANSFER RATES; COLLISIONS; SECTIONS AB A high-resolution IR absorption method is presented for the experimental determination of state-to-state, integral and differential cross sections for rotationally inelastic energy transfer. An infrared chromophore, cooled into its lowest rotational state(s) in a pulsed supersonic expansion, is rotationally excited with low collision probability by a gas pulse from a second supersonic jet. The initial and final populations of the infrared absorber are monitored as a function of J state and of Doppler detuning, via direct absorption of narrow bandwidth light from a continuously tunable, CW infrared laser. The scattered and unscattered species are detected with Doppler-limited spectral resolution (less than or similar to 0.01 cm(-1)), providing quantum-state selectivity not attainable with time-of-flight energy-loss methods. The infrared-based probe also permits study of a much wider class of absorbing species inaccessible to ultraviolet/visible laser-induced fluorescence (LIF) or resonance-enhanced multiphoton ionization (REMPI) methods. From fractional IR absorbances and Beer's law, the column-integrated number densities in each jet are measured directly, which allows absolute, state-to-state, integral cross sections to be determined. Furthermore, the correspondence between the molecular velocity and the observed Doppler shift can be used to extract state-to-state differential cross sections from the high-resolution line shapes. Details of the experimental technique are demonstrated via sample studies of state-to-state integral and differential scattering in rare-gas collisions with CH4. C1 NATL INST STAND & TECHNOL,JOINT INST LAB ASTROPHYS,BOULDER,CO 80309. UNIV COLORADO,DEPT CHEM & BIOCHEM,BOULDER,CO 80309. NR 77 TC 11 Z9 11 U1 2 U2 7 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 SN 0022-3654 J9 J PHYS CHEM-US JI J. Phys. Chem. PD FEB 29 PY 1996 VL 100 IS 9 BP 3402 EP 3413 DI 10.1021/jp952708j PG 12 WC Chemistry, Physical SC Chemistry GA TX766 UT WOS:A1996TX76600016 ER PT J AU Kursinski, ER Hajj, GA Bertiger, WI Leroy, SS Meehan, TK Romans, LJ Schofield, JT McCleese, DJ Melbourne, WG Thornton, CL Yunck, TP Eyre, JR Nagatani, RN AF Kursinski, ER Hajj, GA Bertiger, WI Leroy, SS Meehan, TK Romans, LJ Schofield, JT McCleese, DJ Melbourne, WG Thornton, CL Yunck, TP Eyre, JR Nagatani, RN TI Initial results of radio occultation observations of Earth's atmosphere using the global positioning system SO SCIENCE LA English DT Article ID GRAVITY-WAVES; ASSIMILATION; NEPTUNE AB Recent radio occultation measurements using Global Positioning System satellite transmitters and an orbiting receiver have provided a globally distributed set of high-resolution atmospheric profiles, suggesting that the technique may make a significant contribution to global change and weather prediction programs. Biases in occultation temperatures relative to radiosonde and model data are about 1 kelvin or less in the tropics and are generally less than 0.5 kelvin at higher latitudes. Data quality is sufficient to quantify significant model errors in remote regions. Temperature profiles also reveal either an equatorial Rossby-gravity or an inertio-gravity wave. Such waves provide a fundamental source of momentum for the stratospheric circulation. C1 CALTECH,JET PROP LAB,PASADENA,CA 91125. UNITED KINGDOM METEOROL OFF,BRACKNELL RG12 2SZ,BERKS,ENGLAND. COB,CLIMATE PREDICT CTR,WASHINGTON,DC 20233. RP Kursinski, ER (reprint author), CALTECH,DIV GEOL & PLANETARY SCI,PASADENA,CA 91125, USA. NR 29 TC 177 Z9 197 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 FEB 23 PY 1996 VL 271 IS 5252 BP 1107 EP 1110 DI 10.1126/science.271.5252.1107 PG 4 WC Multidisciplinary Sciences SC Science & Technology - Other Topics GA TW701 UT WOS:A1996TW70100035 ER PT J AU Howe, JD Ashfold, MNR Western, CM Hudgens, JW AF Howe, JD Ashfold, MNR Western, CM Hudgens, JW TI Resonance enhanced multiphoton ionization spectroscopy of the PF radical SO JOURNAL OF CHEMICAL PHYSICS LA English DT Article ID RYDBERG STATES; PHOTOELECTRON-SPECTROSCOPY; ELECTRONIC STATES; PHOSPHORUS; SPECTRUM; ABINITIO; MOLECULE AB PF radicals in both their ground (X(3) Sigma(-)) and metastable (a 1 Delta) electronic states have been produced by the gas phase reaction of F atoms with phosphine in a discharge flow reactor and detected by mass selective resonance enhanced multiphoton ionization (REMPI) spectroscopy in the wavelength range 410-225 nm. Analysis of the longer wavelength end of this spectrum (lambda>328 nm) has enabled identification and spectroscopic characterization of five hitherto unknown Rydberg states of this radical. These we label the h(1) Sigma(+) (T-0=57 324.9 cm(-1)), D (3) Delta (T-0=58 223.0 cm(-1)), E (3) Sigma(-)(T-0=58 690 cm(-1)), i 1 Delta (T-0=59 881.6 cm(-1)), and j (1) Sigma(-) (T-0=61 873.9 cm(-1)) states, respectively. [Origins, relative to the lowest rovibrational level of the ground (X (3) Sigma(-)) state are indicated by the numbers in brackets.] Quantum defect arguments suggest that all five states derive from the electronic configuration [(2) Pi]4p pi(1). Within the shorter wavelength region we identify two additional sets of poorly resolved resonances which we associate with a further two Rydberg states belonging to series converging to the ground state ionization limit, followed by two extensive progressions of bands. Possible assignments for these two progressions are considered. (C) 1996 American Institute of Physics. C1 NIST,CHEM SCI & TECHNOL LAB,DIV CHEM KINET & THERMODYNAM,GAITHERSBURG,MD 20899. RP Howe, JD (reprint author), UNIV BRISTOL,SCH CHEM,CANTOCKS CLOSE,BRISTOL BS8 1TS,AVON,ENGLAND. OI Western, Colin/0000-0002-8336-1690; ashfold, michael/0000-0001-5762-7048 NR 34 TC 2 Z9 2 U1 1 U2 6 PU AMER INST PHYSICS PI WOODBURY PA CIRCULATION FULFILLMENT DIV, 500 SUNNYSIDE BLVD, WOODBURY, NY 11797-2999 SN 0021-9606 J9 J CHEM PHYS JI J. Chem. Phys. PD FEB 22 PY 1996 VL 104 IS 8 BP 2789 EP 2800 DI 10.1063/1.471102 PG 12 WC Chemistry, Physical; Physics, Atomic, Molecular & Chemical SC Chemistry; Physics GA TV787 UT WOS:A1996TV78700005 ER PT J AU Hwang, W Kim, YK Rudd, ME AF Hwang, W Kim, YK Rudd, ME TI New model for electron-impact ionization cross sections of molecules SO JOURNAL OF CHEMICAL PHYSICS LA English DT Article ID DISSOCIATIVE IONIZATION; COLLISIONS; THRESHOLD; RADICALS; C2H6; NH3; H2O; CH4 AB A theoretical model for electron-impact ionization cross sections, which has been developed primarily for atoms and atomic ions, is applied to neutral molecules. The new model combines the binary-encounter theory and the Bethe theory for electron-impact ionization, and uses minimal theoretical data for the ground state of the target molecule, which are readily available from public-domain molecular structure codes such as GAMESS. The theory is called the binary-encounter Bethe (BEB) model, and does not, in principle, involve any adjustable parameters. Applications to 19 molecules, including H-2, NO, CH2, C6H6, and SF6, are presented, demonstrating that the BEB model provides total ionization cross sections by electron impact from threshold to several keV with an average accuracy of 15% or better at the cross section peak, except for SiF3. The BEB model can be applied to stable molecules as well as to transient radicals. (C) 1996 American Institute of Physics. C1 NIST,GAITHERSBURG,MD 20899. UNIV NEBRASKA,DEPT PHYS & ASTRON,LINCOLN,NE 68588. NR 47 TC 329 Z9 330 U1 2 U2 32 PU AMER INST PHYSICS PI WOODBURY PA CIRCULATION FULFILLMENT DIV, 500 SUNNYSIDE BLVD, WOODBURY, NY 11797-2999 SN 0021-9606 J9 J CHEM PHYS JI J. Chem. Phys. PD FEB 22 PY 1996 VL 104 IS 8 BP 2956 EP 2966 DI 10.1063/1.471116 PG 11 WC Chemistry, Physical; Physics, Atomic, Molecular & Chemical SC Chemistry; Physics GA TV787 UT WOS:A1996TV78700023 ER PT J AU Shoute, LCT Mittal, JP Neta, P AF Shoute, LCT Mittal, JP Neta, P TI Reduction and defluorination of pentafluorophenol in aqueous solutions SO JOURNAL OF PHYSICAL CHEMISTRY LA English DT Article ID ABSOLUTE RATE CONSTANTS; LASER FLASH-PHOTOLYSIS; RADICAL-ANIONS; GAMMA-RADIOLYSIS; MATRIX-ISOLATION; DECAFLUOROBENZOPHENONE; PERFLUOROBENZENE; ABSORPTION; RESONANCE; BENZENES AB Hydrated electrons and hydrogen atoms react with pentafluorophenol (PFP) to result in fluoride ion elimination and subsequent production of the tetrafluorophenoxyl radical. Evidence for the formation of this radical was obtained from its reaction with ascorbate, which is oxidized by this species as it is oxidized by other phenoxyl radicals. Tetrafluorophenoxyl radical reacts with OH- to eliminate another fluoride ion and yield the trifluorobenzosemiquinone radical anion. Addition of OH to PFP also leads to fluoride ion elimination to yield the tetrafluorobenzosemiquinone radical anion. Oxidation of PFP by SO4.- or N-3(.) yields the pentafluorophenoxyl radical. C1 NIST,DIV CHEM KINET & THERMODYNAM,GAITHERSBURG,MD 20899. INDIAN INST SCI,JAWAHARLAL NEHRU CTR ADV SCI RES,BANGALORE 560012,KARNATAKA,INDIA. RP Shoute, LCT (reprint author), BHABHA ATOM RES CTR,DIV CHEM,BOMBAY 400085,MAHARASHTRA,INDIA. NR 41 TC 20 Z9 21 U1 0 U2 8 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 SN 0022-3654 J9 J PHYS CHEM-US JI J. Phys. Chem. PD FEB 22 PY 1996 VL 100 IS 8 BP 3016 EP 3019 DI 10.1021/jp9513374 PG 4 WC Chemistry, Physical SC Chemistry GA TX257 UT WOS:A1996TX25700032 ER PT J AU Talukdar, RK Gierczak, T Goldfarb, L Rudich, Y Rao, BSM Ravishankara, AR AF Talukdar, RK Gierczak, T Goldfarb, L Rudich, Y Rao, BSM Ravishankara, AR TI Kinetics of hydroxyl radical reactions with isotopically labeled hydrogen SO JOURNAL OF PHYSICAL CHEMISTRY LA English DT Article ID SHOCK-TUBE TECHNIQUE; H2O + H; TEMPERATURE-RANGE; RATE CONSTANTS; OH; H-2; OH+H-2->H2O+H; SCATTERING; OH+H-2; OD AB The rate coefficients for the reactions of hydroxyl radical (OH) with H-2 (k(1)), HD (k(2)), and D-2 (k(3)) were measured between similar to 230 and similar to 420 K to be k(1) = 7.21 x 10(-20)T(2.69) exp(-1150/T), k(2) = 5.57 x 10(-20)T(2.7) exp(-1258/T), and k(3) = 5.7 x 10(-20)T(2.73) exp(-1580/T) cm(3) molecule(-1) s(-1) using pulsed photolysis to generate OH and laser-induced fluorescence to detect it. Using the same method, the rate coefficients for the reactions of OD with H-2 and D-2 were measured to be equal to k(1) and k3, respectively. In reaction 2, the yield of H was measured to be 0.17 +/- 0.03 and 0;26 +/- 0.05 at 250 and 298 K, respectively, by detecting it using CW Lyman-alpha resonance fluorescence. k(2) was found to be half the sum of k(1) and k(3) over the entire temperature range of this study. The quoted uncertainties are at the 95% confidence level and include estimated systematic errors. On the basis of these findings it is suggested that most, if not all, of the reaction in the range of temperatures studied here may be occurring via tunneling of H/D atoms through the barrier. C1 NOAA, AERON LAB, BOULDER, CO 80303 USA. UNIV COLORADO, COOPERAT INST RES ENVIRONM SCI, BOULDER, CO 80309 USA. UNIV WARSAW, DEPT CHEM, PL-02089 WARSAW, POLAND. UNIV COLORADO, DEPT CHEM & BIOCHEM, BOULDER, CO 80309 USA. UNIV PUNE, DEPT CHEM, POONA 411007, MAHARASHTRA, INDIA. RI Rudich, Yinon/K-1498-2012; TALUKDAR, RANAJIT/G-4530-2013; Ravishankara, Akkihebbal/A-2914-2011; OI TALUKDAR, RANAJIT/0000-0001-6017-8431; Rudich, Yinon/0000-0003-3149-0201 NR 40 TC 56 Z9 56 U1 2 U2 7 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 FEB 22 PY 1996 VL 100 IS 8 BP 3037 EP 3043 DI 10.1021/jp9518724 PG 7 WC Chemistry, Physical SC Chemistry GA TX257 UT WOS:A1996TX25700035 ER PT J AU Brown, LA Vaida, V Hanson, DR Graham, JD Roberts, JT AF Brown, LA Vaida, V Hanson, DR Graham, JD Roberts, JT TI Uptake of chlorine dioxide by model PSCs under stratospheric conditions SO JOURNAL OF PHYSICAL CHEMISTRY LA English DT Article ID NEAR-ULTRAVIOLET SPECTROSCOPY; COLUMN ABUNDANCES; MATRIX-ISOLATION; MCMURDO STATION; OZONE DEPLETION; OCLO; KINETICS; OCIO; ICE; WATER AB The uptake of chlorine dioxide by ice at temperatures approaching those needed for PSC formation in the Antarctic stratosphere was studied. The two approaches used in this investigation involved modeling the surface coverage using kinetic parameters obtained in an ultrahigh-vacuum surface experiment and comparing these results to the uptake measured in a flow tube apparatus. For an OClO gas phase concentration of 5 x 10(10) molecules/cm(3), a surface coverage of approximate to 2 x 10(-4+/-1) monolayers of OClO was estimated on the ice at 189 K from both methods. For an average OClO concentration in the Antarctic stratosphere of 2 x 10(9) molecules/cm(3), a surface coverage of 7 x 10(-6+/-1) monolayers of OClO on PSCs is predicted. C1 UNIV COLORADO,DEPT CHEM & BIOCHEM,BOULDER,CO 80309. NOAA,AERON LAB,BOULDER,CO 80303. UNIV MINNESOTA,DEPT CHEM,MINNEAPOLIS,MN 55455. RI Vaida, Veronica/N-6069-2014 OI Vaida, Veronica/0000-0001-5863-8056 NR 47 TC 23 Z9 23 U1 1 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 FEB 22 PY 1996 VL 100 IS 8 BP 3121 EP 3125 DI 10.1021/jp951664b PG 5 WC Chemistry, Physical SC Chemistry GA TX257 UT WOS:A1996TX25700047 ER PT J AU Russell, TP Piermarini, GJ Block, S Miller, PJ AF Russell, TP Piermarini, GJ Block, S Miller, PJ TI Pressure, temperature reaction phase diagram for ammonium dinitramide SO JOURNAL OF PHYSICAL CHEMISTRY LA English DT Article ID THERMAL-DECOMPOSITION; CHEMISTRY; CELL; KBAR AB The pressure, temperature reaction phase diagram for ammonium dinitramide (ADN) was determined using a high-temperature-high-pressure diamond anvil cell with optical polarizing light microscopy, Fourier transform infrared spectroscopy, laser-Raman spectroscopy, and energy dispersive X-ray diffraction. The phase diagram was determined between ambient pressure and 10.0 GPa over the temperature range from -75 degrees C to decomposition temperatures, or 120 degrees C. The diagram delineates the melting curve for alpha-ADN, a reversible phase transition in alpha-ADN forming a new high-pressure monoclinic polymorph, beta-ADN, and also identifies the pressure and temperature conditions at which a solid phase rearrangement occurs to form ammonium nitrate (AN) and N2O. Energy dispersive X-ray diffraction and Raman spectra were obtained for both alpha- and beta-ADN as a function of pressure at room temperature. C1 NATL INST STAND & TECHNOL,MAT SCI & ENGN LAB,GAITHERSBURG,MD 20899. USN,CTR SURFACE WARFARE,SILVER SPRING,MD 20903. RP Russell, TP (reprint author), USN,RES LAB,DIV CHEM,CODE 6110,WASHINGTON,DC 20375, USA. NR 22 TC 37 Z9 40 U1 0 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 FEB 22 PY 1996 VL 100 IS 8 BP 3248 EP 3251 DI 10.1021/jp952144j PG 4 WC Chemistry, Physical SC Chemistry GA TX257 UT WOS:A1996TX25700066 ER PT J AU Tarek, M Tobias, DJ Klein, ML AF Tarek, M Tobias, DJ Klein, ML TI Molecular dynamics investigation of the surface/bulk equilibrium in an ethanol-water solution SO JOURNAL OF THE CHEMICAL SOCIETY-FARADAY TRANSACTIONS LA English DT Article ID VAPOR INTERFACE; METHANOL; MIXTURES AB Molecular dynamics simulations of the vapour/solution interface, initiated from an ethanol-water mixture at a mole fraction of ethanol, X(e) = 0.1, have been performed. Rapid redistribution of ethanol molecules to the free surface was observed during simulations of two different sized systems. Inspection of the calculated surface structure reveals that after redistributing the ethanol molecules are preferentially oriented such that the alkyl group points out of the solution. A 'depletion layer' of enhanced water density beneath the ethanol surface excess was revealed by the simulation. Analysis of the structure involving molecules dose to the surface shows that water molecules are arranged to maximize the hydrogen bonding between the oriented ethanol and the adjacent water molecules. The enhanced water density beneath the interface results from this optimization. The surface tension calculated from the simulation is ca. 50% higher than the results of macroscopic experimental measurements. This overestimation is attributed to shortcomings in both the potential function and the simulation methodology. The number density profiles of the ethanol surface excess were compared with results from neutron reflectivity measurements. The calculated profiles agree better with the experimental measurements at the calculated surface tension (i.e. X(e) = 0.022) than those reported for X(e) = 0.1 mixtures. C1 UNIV PENN,DEPT CHEM,PHILADELPHIA,PA 19104. NATL INST STAND & TECHNOL,MAT SCI & ENGN LAB,DIV REACTOR RADIAT,GAITHERSBURG,MD 20899. RI Tobias, Douglas/B-6799-2015 NR 20 TC 50 Z9 50 U1 1 U2 13 PU ROYAL SOC CHEMISTRY PI CAMBRIDGE PA THOMAS GRAHAM HOUSE, SCIENCE PARK MILTON ROAD, CAMBRIDGE, CAMBS, ENGLAND CB4 4WF SN 0956-5000 J9 J CHEM SOC FARADAY T JI J. Chem. Soc.-Faraday Trans. PD FEB 21 PY 1996 VL 92 IS 4 BP 559 EP 563 DI 10.1039/ft9969200559 PG 5 WC Chemistry, Physical; Physics, Atomic, Molecular & Chemical SC Chemistry; Physics GA TY910 UT WOS:A1996TY91000008 ER PT J AU Ravishankara, AR Hanson, DR AF Ravishankara, AR Hanson, DR TI Differences in the reactivity of Type I polar stratospheric clouds depending on their phase SO JOURNAL OF GEOPHYSICAL RESEARCH-ATMOSPHERES LA English DT Article ID NITRIC-ACID TRIHYDRATE; SULFURIC-ACID; OZONE DEPLETION; HETEROGENEOUS REACTIONS; ANTARCTIC STRATOSPHERE; INSITU MEASUREMENTS; SULFATE AEROSOLS; VAPOR-PRESSURES; HCL; CHEMISTRY AB It has been suggested that some Type I polar stratospheric clouds (PSCs) are supercooled liquids containing sulfuric acid, water, and nitric acid. We show that the activation of chlorine over supercooled liquids is comparable to that over solid Type I PSCs at the same temperature. Furthermore, at temperatures within a few degrees of the frost point, the reactions of ClONO2 with HCl and H2O, that of HOCl with HCl, and the hydrolysis of N2O5 would be faster if Type I PSCs are liquid solutions rather than solids. Thus chlorine can be rapidly activated without the formation of solid Type I PSCs. C1 UNIV COLORADO, INST RES ENVIRONM SCI, BOULDER, CO USA. UNIV COLORADO, DEPT CHEM & BIOCHEM, BOULDER, CO 80309 USA. RP Ravishankara, AR (reprint author), NOAA, AERON LAB, 325 BROADWAY, BOULDER, CO 80303 USA. RI Ravishankara, Akkihebbal/A-2914-2011 NR 51 TC 78 Z9 78 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 FEB 20 PY 1996 VL 101 IS D2 BP 3885 EP 3890 DI 10.1029/95JD03009 PG 6 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA TW970 UT WOS:A1996TW97000004 ER PT J AU Post, MJ Grund, CJ Weickmann, AM Healy, KR Willis, RJ AF Post, MJ Grund, CJ Weickmann, AM Healy, KR Willis, RJ TI Comparison of Mount Pinatubo and El Chichon volcanic events: Lidar observations at 10.6 and 0.69 mu m SO JOURNAL OF GEOPHYSICAL RESEARCH-ATMOSPHERES LA English DT Article ID AEROSOL; CLOUDS; BACKSCATTER; PROFILES AB Analyses of a dense set of lidar observations of the volcanic clouds from Mount Pinatubo and El Chichon, primarily over Boulder, Colorado, and at a wavelength of 10.59 mu m, reveal notable similarities and differences. The importance of tropopause folding events for purging stratospheric debris into the troposphere is confirmed, as well as the role of gravitational settling to bring debris into the grasp of the folding mechanism. Seasonal influences appear more important than time after eruption in both poleward transport and in purging stratospheric material downward. We discuss the lengthening of the decay process for the Mount Pinatubo clouds by either an equatorial reservoir of debris or by eruptions of Mount Spurr. Simultaneous observations at 0.69 and 10.59 mu m help monitor aerosol effective radii versus altitude with good temporal and vertical resolution. C1 UNIV COLORADO, COOPERAT INST RES ENVIRONM SCI, BOULDER, CO 80306 USA. NOAA, ENVIRONM TECHNOL LAB, BOULDER, CO 80303 USA. RI Weickmann, Ann/I-4445-2013 NR 30 TC 18 Z9 18 U1 0 U2 0 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 2169-897X J9 J GEOPHYS RES-ATMOS JI J. Geophys. Res.-Atmos. PD FEB 20 PY 1996 VL 101 IS D2 BP 3929 EP 3940 DI 10.1029/95JD02926 PG 12 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA TW970 UT WOS:A1996TW97000008 ER PT J AU Grant, WB Browell, EV Long, CS Stowe, LL Grainger, RG Lambert, A AF Grant, WB Browell, EV Long, CS Stowe, LL Grainger, RG Lambert, A TI Use of volcanic aerosols to study the tropical stratospheric reservoir SO JOURNAL OF GEOPHYSICAL RESEARCH-ATMOSPHERES LA English DT Article ID MT-PINATUBO; MOUNT-PINATUBO; POTENTIAL VORTICITY; MIDDLE LATITUDES; POLAR VORTEX; EL-CHICHON; OZONE; ERUPTIONS; CLOUD; SO2 AB Aerosol data obtained by the advanced very high resolution radiometer on NOAA 11, the improved stratospheric and mesospheric sounder on the upper atmospheric research satellite, one airborne lidar system, and several ground-based lidar systems up to 2-1/2 years after the eruption of Mount Pinatubo are used to study stratospheric dynamics. In particular, this study focuses on the tropical stratospheric reservoir and transport from it to northern midlatitudes following the eruption of Mount Pinatubo. This includes: The build-up and removal rates for sulfate aerosol, the position and motion of the center of the reservoir, and the position and width of its boundaries at altitudes of the volcanic aerosols. Ozone data from the total ozone mapping spectrometer were also used to study the position and width of the reservoir boundaries. In addition, ground-based lidar stratospheric aerosol data are used to study aerosol transport from the reservoir to the northern hemisphere as it relates to winds in the tropical stratosphere. Finally, historical in situ and satellite data were used to examine how the time and location of volcanic injections into the stratosphere affect the aerosol decay rates and seasonal variations of aerosol optical depth in the midlatitude stratosphere. C1 UNIV OXFORD, OXFORD OX1 3PU, ENGLAND. NOAA, NWS, NMC, CLIMATE ANAL CTR, CAMP SPRINGS, MD 20746 USA. NOAA, NATL ENVIRONM SATELLITE DATA & INFORMAT SERV, ORA, SATELLITE RES LAB, WASHINGTON, DC 20233 USA. NASA, LANGLEY RES CTR, DIV ATMOSPHER SCI, HAMPTON, VA 23681 USA. RI Grainger, Roy/E-8823-2011; Grant, William/B-8311-2009 OI Grainger, Roy/0000-0003-0709-1315; Grant, William/0000-0002-1439-3285 NR 84 TC 84 Z9 84 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 FEB 20 PY 1996 VL 101 IS D2 BP 3973 EP 3988 DI 10.1029/95JD03164 PG 16 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA TW970 UT WOS:A1996TW97000011 ER PT J AU Mote, PW Rosenlof, KH McIntyre, ME Carr, ES Gille, JC Holton, JR Kinnersley, JS Pumphrey, HC Russell, JM Waters, JW AF Mote, PW Rosenlof, KH McIntyre, ME Carr, ES Gille, JC Holton, JR Kinnersley, JS Pumphrey, HC Russell, JM Waters, JW TI An atmospheric tape recorder: The imprint of tropical tropopause temperatures on stratospheric water vapor SO JOURNAL OF GEOPHYSICAL RESEARCH-ATMOSPHERES LA English DT Article ID MIDDLE ATMOSPHERE; DEHYDRATION; CIRCULATION; PARAMETERIZATION; PERFORMANCE; TRANSPORT; BREAKING; MODEL AB We describe observations of tropical stratospheric water vapor q that show clear evidence of large-scale upward advection of the signal from annual fluctuations in the effective ''entry mixing ratio'' q(E) of air entering the tropical stratosphere, In other words, air is ''marked,'' on emergence above the highest cloud tops, like a signal recorded on an upward moving magnetic tape, We define q(E) as the mean water vapor mixing ratio, at the tropical tropopause, of air that will subsequently rise and enter the stratospheric ''overworld'' at about 400 K. The observations show a systematic phase lag, increasing with altitude, between the annual cycle in q(E) and the annual cycle in q at higher altitudes, The observed phase lag agrees with the phase lag calculated assuming advection by the transformed Eulerian-mean vertical velocity of a q(E) crudely estimated from 100-hPa temperatures, which we use as a convenient proxy for tropopause temperatures, The phase agreement confirms the overall robustness of the calculation and strongly supports the tape recorder hypothesis, Establishing a quantitative link between q(E) and observed tropopause temperatures, however, proves difficult because the process of marking the tape depends subtly on both small- and large-scale processes, The tape speed, or large-scale upward advection speed, has a substantial annual variation and a smaller variation due to the quasi-biennial oscillation, which delays or accelerates the arrival of the signal by a month or two in the middle stratosphere. As the tape moves upward, the signal is attenuated with an e-folding time of about 7 to 9 months between 100 and 50 hPa and about 15 to 18 months between 50 and 20 hPa, constraining possible orders of magnitude both of vertical diffusion K-z and of rates of mixing in from the extratropics. For instance, if there were no mixing in, then K-z would be in the range 0.03-0.09 m(2) s(-1); this is an upper bound on K-z. C1 UNIV COLORADO, NOAA, COOPERAT INST RES ENVIRONM SCI, BOULDER, CO 80309 USA. UK UNIV GLOBAL ATMOSPHER MODELLING PROGRAMME, READING, BERKS, ENGLAND. NOAA, ENVIRONM RES LABS, AERON LAB, BOULDER, CO USA. NATL CTR ATMOSPHER RES, DIV ATMOSPHER CHEM, BOULDER, CO 80307 USA. UNIV WASHINGTON, DEPT ATMOSPHER SCI, SEATTLE, WA 98195 USA. CALTECH, JET PROP LAB, PASADENA, CA 91109 USA. NASA, LANGLEY RES CTR, HAMPTON, VA 23665 USA. UNIV CAMBRIDGE, DEPT APPL MATH & THEORET PHYS, CAMBRIDGE CB3 9EW, ENGLAND. RP Mote, PW (reprint author), UNIV EDINBURGH, DEPT METEOROL, KINGS BLDG, EDINBURGH EH9 3JZ, MIDLOTHIAN, SCOTLAND. RI Rosenlof, Karen/B-5652-2008 OI Rosenlof, Karen/0000-0002-0903-8270 NR 62 TC 441 Z9 444 U1 1 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 FEB 20 PY 1996 VL 101 IS D2 BP 3989 EP 4006 DI 10.1029/95JD03422 PG 18 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA TW970 UT WOS:A1996TW97000012 ER PT J AU Williams, CR Avery, SK AF Williams, CR Avery, SK TI Diurnal nonmigrating tidal oscillations forced by deep convective clouds SO JOURNAL OF GEOPHYSICAL RESEARCH-ATMOSPHERES LA English DT Article ID GENERAL-CIRCULATION MODEL; NON-MIGRATING TIDES; 1987 AUSTRALIAN MONSOON; ATMOSPHERIC TIDES; MIDDLE ATMOSPHERE; MEAN WINDS; TROPICAL CONVECTION; CLIMATE-RESEARCH; INTEGRATED VIEW; GRAVITY-WAVE AB The global distribution of latent heat released by the diurnal oscillations in deep convective precipitating clouds is investigated as a forcing mechanism of diurnal nonmigrating atmospheric tidal modes. The seasonal distribution of this forcing is deduced from 3-hour temporal resolution infrared (11 mu m) radiance measured by four geostationary and two polar orbiting satellites which was transformed into the zonal wavenumber domain yielding migrating and non-migrating oscillations. The dominant wavenumbers in the forcing include the westward propagating 5, 2, and 1 oscillations, the eastward propagating 3 oscillation, and the standing oscillation. These dominant wavenumber oscillations were decomposed into Hough functions to describe their meridional structure. A vertical profile of latent heating rate was estimated and the dominant 22 tidal modes were used in an f plane model to determine the middle atmospheric response to this tropospheric forcing. The f plane model was also excited using heating rates associated with the solar insolation absorption by water vapor. The magnitude of the model atmosphere diurnal winds from both water vapor and latent heat is similar at certain locations. This response suggests that the superposition of many nonmigrating tidal modes forced by the latent heat release of precipitating clouds is important in understanding the middle atmospheric circulation. C1 NOAA, AERON LAB, CIRES, BOULDER, CO 80303 USA. UNIV COLORADO, COOPERAT INST RES ENVIRONM SCI, BOULDER, CO 80309 USA. RI Williams, Christopher/A-2723-2015 OI Williams, Christopher/0000-0001-9394-8850 NR 58 TC 64 Z9 64 U1 1 U2 3 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 2169-897X J9 J GEOPHYS RES-ATMOS JI J. Geophys. Res.-Atmos. PD FEB 20 PY 1996 VL 101 IS D2 BP 4079 EP 4091 DI 10.1029/95JD03007 PG 13 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA TW970 UT WOS:A1996TW97000019 ER PT J AU Huebert, BJ Pszenny, A Blomquist, B AF Huebert, BJ Pszenny, A Blomquist, B TI The ASTEX/MAGE experiment SO JOURNAL OF GEOPHYSICAL RESEARCH-ATMOSPHERES LA English DT Article ID BOUNDARY-LAYER; CLOUD AB The Atlantic Stratocumulus Transition Experiment/Marine Aerosol and Gas Exchange (ASTEX/MAGE) was a multinational experiment designed to study the relationship between marine chemistry, aerosols, clouds, and air/sea exchange. Several aircraft, ships, and island sites supported measurements of marine boundary layer chemistry in both pristine and polluted North Atlantic air masses in the vicinity of the Azores in June of 1992. The International Global Atmospheric Chemistry (IGAC) Program's MAGE activity organized the chemical experiments in ASTEX because such experiments are beyond the capabilities of any one platform, discipline, or nation working alone. One highlight of ASTEX/MAGE was the development of a Lagrangian experimental strategy. It offered a unique way of constraining fluxes and reaction rates by observing the effect those processes have on a tagged parcel of air. C1 DREXEL UNIV, DEPT CHEM, PHILADELPHIA, PA 19104 USA. NOAA, ATLANTIC OCEANOG & METEOROL LAB, OCEAN CHEM DIV, MIAMI, FL 33149 USA. RP Huebert, BJ (reprint author), UNIV HAWAII MANOA, DEPT OCEANOG, 1000 POPE RD, HONOLULU, HI 96822 USA. NR 14 TC 36 Z9 36 U1 0 U2 0 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 2169-897X J9 J GEOPHYS RES-ATMOS JI J. Geophys. Res.-Atmos. PD FEB 20 PY 1996 VL 101 IS D2 BP 4319 EP 4329 DI 10.1029/95JD01531 PG 11 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA TW970 UT WOS:A1996TW97000036 ER PT J AU Businger, S Chiswell, SR Ulmer, WC Johnson, R AF Businger, S Chiswell, SR Ulmer, WC Johnson, R TI Balloons as a Lagrangian measurement platform for atmospheric research SO JOURNAL OF GEOPHYSICAL RESEARCH-ATMOSPHERES LA English DT Article ID GLOBAL POSITIONING SYSTEM; BOUNDARY-LAYER; TRANSPORT; MODEL AB The history of constant-level balloons as observational platforms for atmospheric research is reviewed. Recent experience in using simple tetroons with Global Positioning System transponders for long-range tracking during the Atlantic Stratocumulus Transition Experiment (ASTEX) is presented, along with an overview of the results of the ASTEX/Marine Aerosol and Gas Exchange Lagrangian strategy experiments. Progress in balloon materials and tracking capabilities is discussed, and a design is presented for an economical, lightweight ''smart balloon'' for use in future Lagrangian strategy, atmospheric chemistry experiments. C1 NOAA, AIR RESOURCES FIELD RES DIV, IDAHO FALLS, ID 83402 USA. RP Businger, S (reprint author), UNIV HAWAII, DEPT METEOROL, 2525 CORNEA RD, HONOLULU, HI 96822 USA. NR 68 TC 17 Z9 17 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 FEB 20 PY 1996 VL 101 IS D2 BP 4363 EP 4376 DI 10.1029/95JD00559 PG 14 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA TW970 UT WOS:A1996TW97000040 ER PT J AU Jensen, TL Kreidenweis, SM Kim, Y Sievering, H Pszenny, A AF Jensen, TL Kreidenweis, SM Kim, Y Sievering, H Pszenny, A TI Aerosol distributions in the North Atlantic marine boundary layer during Atlantic Stratocumulus Transition Experiment Marine Aerosol and Gas Exchange SO JOURNAL OF GEOPHYSICAL RESEARCH-ATMOSPHERES LA English DT Article ID SIZE DISTRIBUTIONS; SPECTROMETER PROBE; OPTICAL-PROPERTIES; CLOUDS; MODEL AB Marine boundary layer aerosol size distributions observed during June 1992 are described. Measurements were made from on board the National Oceanic and Atmospheric Administration ship Malcolm Baldrige in support of the Atlantic Stratocumulus Transition Experiment/Marine Aerosol and Gas Exchange field experiment in the area surrounding 32 degrees N latitude and 25 degrees W longitude. Measurements obtained from three instruments: the differential mobility particle sizer, the active scattering aerosol spectrometer probe, and the forward scattering spectrometer probe, were used to investigate the contributions of the different aerosol modes to total number, surface area, and volume concentrations. It was observed that aerosol populations in air masses that appear to have originated from remote marine areas have a bimodal number distribution with total number concentrations ranging from 200 to 800 particles cm(-3). In air masses that have been affected by anthropogenic emissions, the aerosol size distributions become monomodal and total number concentrations increase to 500 to 1800 cm(-3) The data also suggest that air mass boundaries can be very sharp and that there may be some mesoscale variability in the aerosol population within an air mass. C1 COLORADO STATE UNIV, DEPT ATMOSPHER SCI, FT COLLINS, CO 80523 USA. UNIV COLORADO, NOAA, COOPERAT INST RES ENVIRONM SCI, BOULDER, CO 80309 USA. NOAA, ATLANTIC OCEANOG & METEOROL LAB, OCEAN CHEM DIV, MIAMI, FL 33149 USA. UNIV COLORADO, CTR ENVIRONM SCI, DENVER, CO 80217 USA. RI Kreidenweis, Sonia/E-5993-2011 OI Kreidenweis, Sonia/0000-0002-2561-2914 NR 14 TC 27 Z9 27 U1 0 U2 3 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 2169-897X J9 J GEOPHYS RES-ATMOS JI J. Geophys. Res.-Atmos. PD FEB 20 PY 1996 VL 101 IS D2 BP 4455 EP 4467 DI 10.1029/95JD00506 PG 13 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA TW970 UT WOS:A1996TW97000048 ER PT J AU SpringerYoung, M Erickson, DJ Carsey, TP AF SpringerYoung, M Erickson, DJ Carsey, TP TI Carbon monoxide gradients in the marine boundary layer of the North Atlantic Ocean SO JOURNAL OF GEOPHYSICAL RESEARCH-ATMOSPHERES LA English DT Article ID SEA-WATER; METHANE; OXIDATION; HYDROGEN; SURFACE; CO; HYDROCARBONS; GASES AB We present an observational data set that suggests that the ocean source of carbon monoxide (CO) may influence the atmospheric CO concentration in the marine boundary layer (MEL). Atmospheric CO concentration gradient data obtained during the 1992 Atlantic Stratocumulus Transition Experiment Marine Aerosol and Gas Exchange (ASTEX/MAGE) show significantly (range of 2-47 ppbv, average of 15 ppbv) more CO at altitudes of 0.05 to 0.5 m above sea level as compared to 10 m above sea level. The seawater CO concentrations needed to support the fluxes obtained from an atmospheric gradient calculation are much higher than generally reported in the literature. However, studies of CO production by Jones and Amador (1993) and data from Seller (1978) suggest the possibility that CO production and the resultant flux to the MBL could be 1-2 orders of magnitude higher than currently estimated using seawater pumped from depths of 4-10 m below the sea-air interface. We infer that the surface ocean production and sea-air exchange of photochemically produced trace gases such as CO may participate in physical, chemical and biological processes on vastly different spatial and temporal scales than those inherent to more stable species such as CO2. C1 NATL CTR ATMOSPHER RES, BOULDER, CO 80307 USA. RP SpringerYoung, M (reprint author), NOAA, ATLANTIC OCEANOG & METEOROL LAB, 4301 RICKENBAKER CAUSEWAY, MIAMI, FL 33149 USA. RI Carsey, Thomas/B-7939-2014 OI Carsey, Thomas/0000-0001-9964-5092 NR 30 TC 10 Z9 11 U1 0 U2 1 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 2169-897X J9 J GEOPHYS RES-ATMOS JI J. Geophys. Res.-Atmos. PD FEB 20 PY 1996 VL 101 IS D2 BP 4479 EP 4484 DI 10.1029/95JD01709 PG 6 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA TW970 UT WOS:A1996TW97000050 ER PT J AU Jonsson, L Levine, ZH Wilkins, JW AF Jonsson, L Levine, ZH Wilkins, JW TI Large local-field corrections in optical rotatory power of quartz and selenium SO PHYSICAL REVIEW LETTERS LA English DT Article ID FORMALISM; GERMANIUM; SYSTEMS; SILICON AB We show that local fields can increase the rotatory power rho of nonconductors by a factor of 10-in contrast to the typical 10% effect in other properties. We present calculations for quartz and Se, and a general method to estimate the size of local-field corrections. Notably, only scalar local fields are needed despite the vector character of light. A self-energy-corrected local-density band structure yields corrections to rho of a factor of +7 in quartz and -4 in Se. These values are 30% above experiment for quartz, and, for one sign choice, within the 50% error bars for Se. C1 NATL INST STAND & TECHNOL,GAITHERSBURG,MD 20899. RP Jonsson, L (reprint author), OHIO STATE UNIV,DEPT PHYS,174 W 18TH AVE,COLUMBUS,OH 43210, USA. NR 26 TC 13 Z9 13 U1 0 U2 0 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 0031-9007 J9 PHYS REV LETT JI Phys. Rev. Lett. PD FEB 19 PY 1996 VL 76 IS 8 BP 1372 EP 1375 DI 10.1103/PhysRevLett.76.1372 PG 4 WC Physics, Multidisciplinary SC Physics GA TV693 UT WOS:A1996TV69300048 ER PT J AU Elkins, JW Fahey, DW Gilligan, JM Dutton, GS Baring, TJ Volk, CM Dunn, RE Myers, RC Montzka, SA Wamsley, PR Hayden, AH Butler, JH Thompson, TM Swanson, TH Dlugokencky, EJ Novelli, PC Hurst, DF Lobert, JM Ciciora, SJ McLaughlin, RJ Thompson, TL Winkler, RH Fraser, PJ Steele, LP Lucarelli, MP AF Elkins, JW Fahey, DW Gilligan, JM Dutton, GS Baring, TJ Volk, CM Dunn, RE Myers, RC Montzka, SA Wamsley, PR Hayden, AH Butler, JH Thompson, TM Swanson, TH Dlugokencky, EJ Novelli, PC Hurst, DF Lobert, JM Ciciora, SJ McLaughlin, RJ Thompson, TL Winkler, RH Fraser, PJ Steele, LP Lucarelli, MP TI Airborne gas chromatograph for in situ measurements of long-lived species in the upper troposphere and lower stratosphere SO GEOPHYSICAL RESEARCH LETTERS LA English DT Article ID TRACE GASES; FLIGHTS; RATIOS; RATES AB A new instrument, the Airborne Chromatograph for Atmospheric Trace Species IV (ACATS-IV), for measuring long-lived species in the upper troposphere and lower stratosphere is described. Using an advanced approach to gas chromatography and electron capture detection, the instrument can detect low levels of CFC-II (CCl3F), CFC-12 (CCl2F2), CFC-113 (CCl2F-CClF2), methyl chloroform (CH3CCl3), carbon tetrachloride (CCl4), nitrous oxide (N2O), sulfur hexafluoride (SF6), Halon-1211 (CBrClF2), hydrogen (H-2), and methane (CH4) acquired in ambient samples every 180 or 360 a. The instrument operates fully-automated onboard the NASA ER-2 high-altitude aircraft on flights lasting up to 8 hours or more in duration. Recent measurements include 24 successful flights covering a broad latitude range (70 degrees S-61 degrees N) during the Airborne Southern Hemisphere Ozone Experiment/Measurements for Assessing the Effects of Stratospheric Aircraft (ASHOE/MAESA) campaign in 1994. C1 NOAA,AERON LAB,BOULDER,CO 80303. UNIV COLORADO,CIRES,BOULDER,CO 80309. CSIRO,DAR,MORDIALLOC,VIC 3195,AUSTRALIA. MONASH UNIV,COOPERAT RES CTR SO HEMISPHERE METEOROL,CLAYTON,VIC 3168,AUSTRALIA. RP Elkins, JW (reprint author), NOAA,CLIMATE MONITORING & DIAGNOST LAB,325 BROADWAY,BOULDER,CO 80303, USA. RI Steele, Paul/B-3185-2009; Fraser, Paul/D-1755-2012; McLaughlin, Richard/I-4386-2013; Ciciora, Steven/I-4916-2013; Gilligan, Jonathan/I-8938-2014; Hurst, Dale/D-1554-2016; Fahey, David/G-4499-2013; OI Steele, Paul/0000-0002-8234-3730; Gilligan, Jonathan/0000-0003-1375-6686; Hurst, Dale/0000-0002-6315-2322; Fahey, David/0000-0003-1720-0634; Montzka, Stephen/0000-0002-9396-0400 NR 17 TC 133 Z9 134 U1 0 U2 11 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 SN 0094-8276 J9 GEOPHYS RES LETT JI Geophys. Res. Lett. PD FEB 15 PY 1996 VL 23 IS 4 BP 347 EP 350 DI 10.1029/96GL00244 PG 4 WC Geosciences, Multidisciplinary SC Geology GA TW551 UT WOS:A1996TW55100008 ER PT J AU Kourafalou, VH Oey, LY Wang, JD Lee, TN AF Kourafalou, VH Oey, LY Wang, JD Lee, TN TI The fate of river discharge on the continental shelf .1. Modeling the river plume and the inner shelf coastal current SO JOURNAL OF GEOPHYSICAL RESEARCH-OCEANS LA English DT Article ID ESTUARINE PLUMES; CIRCULATION; FRONTS; DRIVEN; WATER; FLOWS AB We study the development and evolution of buoyant river plumes on the continental shelf, Our calculations are based on three-dimensional numerical simulations, where the river runoff is introduced as a volume of zero salinity water in the continuity equation and mixing is provided by the model's turbulence closure scheme and wind forcing, In the absence of wind forcing the modeled river plumes typically consist of an offshore bulge and a coastal current in the direction of Kelvin wave propagation, We propose a plume classification scheme based on a bulk Richardson number, which expresses the relative magnitude of the buoyancy-induced stratification versus the available mixing, When the ratio of the discharge and shear velocities is greater (less) than 1, the plume is categorized as supercritical (subcritical); that is, the width of the bulge Is greater (less) than the width of the coastal current, Supercritical plumes are often characterized by a meandering pattern along the coastal current,caused by a baroclinic instability process. For a given discharge, subcritical plumes are produced by large mixing and/or shallow water depths. In the presence of wind forcing the favorable conditions for offshore removal of coastal low-salinity waters include high river runoff and strong upwelling-favorable wind stress. When the rivers are treated as individual sources of freshwater (''point source'' behavior), the wind-driven flow may exhibit substantial spatial variability. Under the above removal conditions, strong offshore transport takes place in ''jetlike'' flow regions within the river plume, in contrast to the downwind acceleration of adjacent waters. When the rivers are treated as a long ''line source'' of freshwater, the plume region resembles a coastal low-salinity band and the above removal conditions trigger offshore transport that is most pronounced at the ''head'' of the source. C1 UNIV MIAMI,ROSENSTIEL SCH MARINE & ATMOSPHER SCI,DIV METEOROL & PHYS OCEANOG,MIAMI,FL 33149. PRINCETON UNIV,ATMOSPHER & OCEAN SCI PROGRAM,PRINCETON,NJ 08544. UNIV MIAMI,ROSENSTIEL SCH MARINE & ATMOSPHER SCI,DIV APPL MARINE PHYS,MIAMI,FL 33149. NR 28 TC 211 Z9 217 U1 1 U2 18 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 FEB 15 PY 1996 VL 101 IS C2 BP 3415 EP 3434 DI 10.1029/95JC03024 PG 20 WC Oceanography SC Oceanography GA TW390 UT WOS:A1996TW39000001 ER PT J AU Kourafalou, VH Lee, TN Oey, LY Wang, JD AF Kourafalou, VH Lee, TN Oey, LY Wang, JD TI The fate of river discharge on the continental shelf .2. Transport of coastal low-salinity waters under realistic wind and tidal forcing SO JOURNAL OF GEOPHYSICAL RESEARCH-OCEANS LA English DT Article ID SOUTHEASTERN UNITED-STATES; SOUTH-ATLANTIC BIGHT; GULF-STREAM; CIRCULATION; MODEL; FLOW; VARIABILITY; CHARLESTON; SURFACE; WINTER AB A three-dimensional numerical simulation of shelf circulation is presented. We employ realistic forcing for the Southeast U.S. Continental Shelf during the spring season. We show that the strongest offshore transport of river-induced, coastal, low-salinity waters and associated materials occurs near the surface. The preferred mean pathway is in the northeastward direction, and it takes about 2 months to cross the entire shelf. Owing to the mean direction of surface transport and the topography of the South Atlantic Eight shelf, the preferred location for springtime removal is off Charleston, South Carolina, and presumably in the vicinity of the Charleston Bump, The transport and fate of the river-induced, coastal, low-salinity waters during the spring season are determined by (1) the stratification of nearshore waters, which is due to the high river runoff and causes the decoupling between ''near-surface'' and ''near-bottom'' layers; (2) the prevailing northeastward winds, which cause significant offshore transport within the shallow near-surface Ekman layer; and (3) the tidally induced bottom stirring (M(2) tides). Comparison of model and data time series of currents shows very good agreement, Standard deviations of the model and data-computed empirical orthogonal functions are almost identical, while the respective variance-conserving spectra agree both in amplitude and phase. C1 UNIV MIAMI,ROSENSTIEL SCH MARINE & ATMOSPHER SCI,DIV METEOROL & PHYS OCEANOG,MIAMI,FL 33149. UNIV MIAMI,ROSENSTIEL SCH MARINE & ATMOSPHER SCI,DIV APPL MARINE PHYS,MIAMI,FL 33149. PRINCETON UNIV,ATMOSPHER & OCEAN SCI PROGRAM,PRINCETON,NJ 08544. NR 26 TC 94 Z9 97 U1 0 U2 8 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 FEB 15 PY 1996 VL 101 IS C2 BP 3435 EP 3455 DI 10.1029/95JC03025 PG 21 WC Oceanography SC Oceanography GA TW390 UT WOS:A1996TW39000002 ER PT J AU vanGeen, A Husby, DM AF vanGeen, A Husby, DM TI Cadmium in the California current system: Tracer of past and present upwelling SO JOURNAL OF GEOPHYSICAL RESEARCH-OCEANS LA English DT Article ID NORTHEAST PACIFIC WATERS; COASTAL TRANSITION ZONE; SAN-FRANCISCO BAY; COPPER; DISTRIBUTIONS; PHYTOPLANKTON; FORAMINIFERA; NUTRIENTS; SEAWATER; NICKEL AB Over 100 samples were collected off the west coast of North America during 1991-1993 to determine the relation between wind-driven upwelling and nearshore concentrations of dissolved silicate (Si), phosphate (P), and cadmium (Cd). Highly enriched in deep water offshore, these constituents are sensitive indicators of upwelling. Coastal water was sampled from the shore in January and June 1992 at 12 sites distributed between 36 degrees and 48 degrees N latitude. In January the composition of nearshore water along this transect was fairly uniform: 5-15 mu mol/kg for Si, 0.5 to 1.0 mu mol/kg for P, and 0.1-0.3 nmol/kg for Cd. In June, elevated concentrations of Si (30 mu mol/kg), P (2.0 mu mol/kg), and Cd (0.6 nmol/kg) revealed a region of intense upwelling between 38 degrees and 40 degrees N. The pattern is broadly consistent with meridional gradients in coastal upwelling calculated from the long-term mean of alongshore winds compiled from ship reports. Nearshore water was also collected biweekly to monthly at two sites 3 km apart near San Francisco Bay (37.5 degrees N) during 1991-1993. The variability seen in the time series suggests that the composition of nearshore water integrates the effect of alongshore winds over timescales of several weeks. Seasonal variations in Si (5-50 mu mol/kg), P (0.5-2.5 mu mol/kg), and Cd (0.1-0.8 nmol/kg) concentrations were consistent with upwelling during spring and summer. Maximum Si, P, and Cd concentrations reached in May 1991 were consistent with advection to the very nearshore region from a depth of about 300 m relative to a vertical profile at a distance of 200 km from the coast. Nearshore Si, P, and Cd concentrations were reduced relative to 1991 in 1992 and, to a lesser extent, in 1993 due to weaker upwelling linked to the warm phase of the Fl Nino-Southern Oscillation. During periods of weaker upwelling or downwelling, variations in P, Si, and Cd concentrations became uncoupled. There is a good correlation between the coastal Cd time series near San Francisco Bay (37.5 degrees N) and a second order polynomial function of the the upwelling index of Bakun [1975] at 35 degrees N, filtered with a 30-day running mean (r(2) = 0.71, n=39). The index is a daily estimate of coastal upwelling calculated from 6-hourly mean atmospheric pressure distributions at 36 degrees N. From this function and a record of daily upwelling indices we infer a range of annually averaged coastal Cd concentrations of at least 0.3-0.5 nmol/kg since 1967. Cd/Ca ratios in shells of foraminifera from San Francisco Bay suggest that average coastal ed concentrations 3500-4500 years ago were at the upper end of this range. C1 NOAA,PACIFIC FISHERIES ENVIRONM GRP,SW FISHERIES SCI CTR,MONTEREY,CA 93942. US GEOL SURVEY,MENLO PK,CA 94025. RP vanGeen, A (reprint author), COLUMBIA UNIV,LAMONT DOHERTY GEOL OBSERV,PALISADES,NY 10964, USA. NR 50 TC 38 Z9 38 U1 0 U2 7 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 FEB 15 PY 1996 VL 101 IS C2 BP 3489 EP 3507 DI 10.1029/95JC03302 PG 19 WC Oceanography SC Oceanography GA TW390 UT WOS:A1996TW39000005 ER PT J AU Belkin, IM Gordon, AL AF Belkin, IM Gordon, AL TI Southern Ocean fronts from the Greenwich meridian to Tasmania SO JOURNAL OF GEOPHYSICAL RESEARCH-OCEANS LA English DT Review ID ANTARCTIC CIRCUMPOLAR CURRENT; DRAKE PASSAGE; WATER MASSES; AGULHAS CURRENT; INDIAN-OCEAN; POLAR FRONT; THERMAL FRONTS; ATLANTIC OCEAN; WEDDELL GYRE; CIRCULATION AB All available meridional sections have been analyzed to investigate the evolution of main fronts between 0 degrees and 150 degrees E. The central South Atlantic is featured by the Subtropical Frontal Zone (STFZ), bordered by the North and South Subtropical Fronts (NSTF and SSTF, respectively), and by the Polar Frontal Zone (PFZ), bordered by the Subantarctic and Polar Fronts (SAF and PF, respectively). This structure becomes more complex in the African sector as the Agulhas Retroflection and the bottom topography force a more convoluted pattern. The Retroflection and associated Agulhas Front (AF) press the SSTF from 38 degrees to 42 degrees-43 degrees S. Strong interactions of the AF, SSTF, and SAF with topography shift the fronts but do not obliterate them. The AF can be traced reliably up to 52 degrees E, sometimes up to 75 degrees E. The SAF is deflected from 45 degrees to 43 degrees S by the Mid-Ocean Ridge and converges with the SSTF north of the Prince Edward Islands to form a combined SSTF/SAF, This front intensifies east of 50 degrees-52 degrees E as a result of the confluence with the AF, and between 52 degrees and 65 degrees E a triple AF/SSTF/SAF (''the Crozet Front'') is observed. The PF continues along 49 degrees and 50 degrees S between the Crozet Plateau and the Ob-Lena (Conrad) Rise, passing north of Kerguelen,; nearly joining the triple Crozet Front. Downstream of the Kerguelen-Amsterdam Passage the canonical structure is being restored (SSTF, SAF, PF); however, the front parameters in the Australian sector are different from the African sector, largely because of strong air-sea interaction and cross-frontal exchanges in the Crozet-Kerguelen region. The SSTF, squeezed between the AF and SAF, loses characteristics to both. The SSTF/SAF interaction results in the Australian SAF being warmer and saltier downstream, while the SSTF becomes shallower and weaker. The Australian STF derives its characteristics mostly from the AF, thus bringing the modified Agulhas waters' to the Pacific Ocean. The newly defined North Subtropical Front (NSTF) was distinguished in the Indian Ocean between 31 degrees and 38 degrees S. The front marks the southern boundary of the subtropical salty, warm water pool of the central South Indian Ocean. The NSTF location is coincident with the position of the wind convergence between westerlies and easterlies, suggesting the possible wind-driven frontogenesis. C1 COLUMBIA UNIV, LAMONT DOHERTY GEOL OBSERV, PALISADES, NY 10964 USA. RUSSIAN ACAD SCI, SHIRSHOV INST OCEANOL, MOSCOW, RUSSIA. RP Belkin, IM (reprint author), NOAA, NATL OCEANOG DATA CTR, OCEAN CLIMATE LAB, E-OC5, 1315 E WEST HIGHWAY, SILVER SPRING, MD 20910 USA. RI Gordon, Arnold/H-1049-2011 OI Gordon, Arnold/0000-0001-6480-6095 NR 107 TC 460 Z9 470 U1 2 U2 42 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 FEB 15 PY 1996 VL 101 IS C2 BP 3675 EP 3696 DI 10.1029/95JC02750 PG 22 WC Oceanography SC Oceanography GA TW390 UT WOS:A1996TW39000017 ER PT J AU Kieber, DJ Jiao, JF Kiene, RP Bates, TS AF Kieber, DJ Jiao, JF Kiene, RP Bates, TS TI Impact of dimethylsulfide photochemistry on methyl sulfur cycling in the equatorial Pacific Ocean SO JOURNAL OF GEOPHYSICAL RESEARCH-OCEANS LA English DT Article ID CLOUD CONDENSATION NUCLEI; MARINE EUKARYOTIC ALGAE; ATMOSPHERIC SULFUR; CARBOHYDRATE SOLUTES; QUATERNARY AMMONIUM; OSMOTIC ADJUSTMENT; TERTIARY SULFONIUM; ESTUARINE WATERS; INORGANIC-IONS; SULFIDE AB Shipboard experiments were conducted in the equatorial Pacific Ocean to ascertain the relative importance of atmospheric ventilation, biological consumption, and photolysis in the removal of dimethylsulfide (DMS) from seawater. Comparisons were made at a series of sampling locations in a transect from 12 degrees N 140 degrees W to 12 degrees S 135 degrees W, as part of the International Global Atmospheric Chemistry project's Marine Aerosol and Gas Exchange cruise in February-March 1992. Turnover rate constants for DMS were used to compare the different removal pathways over three depth intervals (0-1 m, 0-20 m, and 0-60 m). In the surface mixed layer (0-60 m) the DMS turnover rate constants ranged from 0.02 to 0.19 day(-1) for atmospheric ventilation, 0.04 to 0.66 day(-1) for biological consumption, and 0.05 to 0.15 day(-1) for photolysis. When all three processes are considered, the corresponding turnover time for DMS ranges from 1 to 4 days, with photolysis accounting for 7%-40% of the total turnover of DMS. Laboratory irradiations were conducted with stored seawater samples to study the kinetics and wavelength dependence of DMS photolysis. Salient results were (1) the photolysis of DMS followed pseudo first-order kinetics, (2) dimethylsulfoxide was a minor (14%) product of DMS photolysis, and (3) the photolysis of DMS in seawater under natural light conditions occurred primarily at wavelengths between 380 and 460 nm. On the basis of these results, we predict that the photolysis of DMS will occur at appreciable depths in the photic zone in oligotrophic marine environments (similar to 60 m). An important finding of this study is that atmospheric loss, biological consumption, and photolysis are all important removal pathways for DMS in the photic zone of the equatorial Pacific Ocean. The relative importance of each pathway is a function of the depth interval considered, sampling location, and meteorological conditions. C1 NOAA,PACIFIC MARINE ENVIRONM LAB,SEATTLE,WA 98115. UNIV SO ALABAMA,DEPT MARINE SCI,MOBILE,AL 36688. MARINE ENVIRONM SCI CONSORTIUM,DAUPHIN ISL SEA LAB,DAUPHIN ISL,AL. RP Kieber, DJ (reprint author), SUNY COLL ENVIRONM SCI & FORESTRY,DEPT CHEM,1 FORESTRY DR,SYRACUSE,NY 13210, USA. RI Bates, Timothy/L-6080-2016 NR 39 TC 174 Z9 181 U1 1 U2 10 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 FEB 15 PY 1996 VL 101 IS C2 BP 3715 EP 3722 DI 10.1029/95JC03624 PG 8 WC Oceanography SC Oceanography GA TW390 UT WOS:A1996TW39000019 ER PT J AU Fairall, CW Bradley, EF Rogers, DP Edson, JB Young, GS AF Fairall, CW Bradley, EF Rogers, DP Edson, JB Young, GS TI Bulk parameterization of air-sea fluxes for Tropical Ocean Global Atmosphere Coupled Ocean Atmosphere Response Experiment SO JOURNAL OF GEOPHYSICAL RESEARCH-OCEANS LA English DT Article ID EQUATORIAL PACIFIC-OCEAN; SURFACE-LAYER; TURBULENT FLUXES; BOUNDARY-LAYER; HEAT-FLUX; TEMPERATURE; WIND; ROUGHNESS; COEFFICIENTS; STABILITY AB This paper describes the various physical processes relating near-surface atmospheric and oceanographic bulk variables; their relationship to the surface fluxes of momentum, sensible heat, and latent heat; and their expression in a bulk flux algorithm. The algorithm follows the standard Monin-Obukhov similarity approach for near-surface meteorological measurements but includes separate models for the ocean's cool skin and the diurnal warm layer, which are used to derive true skin temperature from the bulk temperature measured at some depth near the surface. The basic structure is an outgrowth of the Liu-Katsaros-Businger [Liu et at, 1979] method, with modifications to include a different specification of the roughness/stress relationship, a gustiness velocity to account for the additional flux induced by boundary layer scale variability, and profile functions obeying the convective limit. Additionally, we have considered the contributions of the sensible heat carried by precipitation and the requirement that the net dry mass flux be zero (the so-called Webb correction [Webb et at, 1980]). The algorithm has been tuned to fit measurements made on the R/V Moana Wave in the three different cruise legs made during the Coupled Ocean-Atmosphere Response Experiment. These measurements yielded 1622 fifty-min averages of fluxes and bulk variables in the wind speed range from 0.5 to 10 m s(-1). The analysis gives statistically reliable values for the Charnock [1955] constant (beta = 0.011) and the gustiness parameter (beta = 1.25). An overall mean value for the latent heat flux, neutral bulk-transfer coefficient was 1.11 x 10(-3), declining slightly with increasing wind speed. Mean values for the sensible and latent heat fluxes were 9.1 and 103.5 W m(-2); mean values for the Webb and rain heat fluxes were 2.5 and 4.5 W m(-2). Accounting for all factors, the net surface heat transfer to the ocean was 17.9 +/- 10 W m(-2). C1 CSIRO,CTR ENVIRONM MECH,CANBERRA,ACT 2601,AUSTRALIA. WOODS HOLE OCEANOG INST,DEPT APPL OCEAN PHYS & ENGN,WOODS HOLE,MA 02543. UNIV CALIF SAN DIEGO,SCRIPPS INST OCEANOG,PHYS OCEANOG RES DIV,LA JOLLA,CA 92093. PENN STATE UNIV,DEPT METEOROL,UNIVERSITY PK,PA 16802. RP Fairall, CW (reprint author), NOAA,ENVIRONM TECHNOL LAB,325 BROADWAY,BOULDER,CO 80303, USA. RI Bradley, Frank/I-6574-2013 NR 63 TC 1065 Z9 1110 U1 6 U2 88 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 FEB 15 PY 1996 VL 101 IS C2 BP 3747 EP 3764 DI 10.1029/95JC03205 PG 18 WC Oceanography SC Oceanography GA TW390 UT WOS:A1996TW39000021 ER PT J AU Udovic, TJ Huang, Q Rush, JJ AF Udovic, TJ Huang, Q Rush, JJ TI Characterization of the structure of LaD2.50 by neutron powder diffraction SO JOURNAL OF SOLID STATE CHEMISTRY LA English DT Article ID ELECTRICAL-RESISTIVITY MEASUREMENTS; METAL-INSULATOR-TRANSITION; RARE-EARTH HYDRIDES; X-RAY; LANTHANUM TRIHYDRIDE; SYSTEM; MAGNETISM; BEHAVIOR; CEH2+X AB Neutron powder diffraction (NPD) measurements of the rare-earth deuteride LaD2.50 were undertaken between 10 and 430 K. Rietveld refinements indicated that, above similar to 385 K, the LaD2.50 structure is cubic (Fm3m) with deuterium fully occupying the tetrahedral (t) interstices of the fee La lattice and the excess deuterium occupying a portion of the octahedral to) interstices with full statistical disorder. As the temperature is decreased below similar to 385 R, the LaD2.50 structure undergoes a tetragonal distortion concomitant with the onset of deuterium long-range order (I4(1)/amd) in the o sublattice, similar to previous structural results for the light-rare-earth deuterides RD(2+x) for 0.3 < x < 0.5. Fully developed long-range order is established in the vicinity of 200 to 230 K. Considering the o sublattice as residing in a family of (042)(Cubic) planes, perfect long-range order can be described as a repeating four-plane sequence comprised of two consecutive planes possessing fully occupied o sites followed by two consecutive planes possessing fully vacant o sites. This ordering is accompanied by correlated basal-plane displacements of the t-site deuterium atoms along either the a or b axes in response to repulsive interactions with the nearest-neighbor D-o atoms. Moreover, the c-directed La-D-o bond distances are decreased by a displacement of the La atoms toward the D-o atoms. (C) 1996 Academic Press, Inc. C1 UNIV MARYLAND,DEPT MAT & NUCL ENGN,COLLEGE PK,MD 20742. RP Udovic, TJ (reprint author), NATL INST STAND & TECHNOL,MAT SCI & ENGN LAB,GAITHERSBURG,MD 20899, USA. NR 38 TC 15 Z9 15 U1 0 U2 1 PU ACADEMIC PRESS INC JNL-COMP SUBSCRIPTIONS PI SAN DIEGO PA 525 B ST, STE 1900, SAN DIEGO, CA 92101-4495 SN 0022-4596 J9 J SOLID STATE CHEM JI J. Solid State Chem. PD FEB 15 PY 1996 VL 122 IS 1 BP 151 EP 159 DI 10.1006/jssc.1996.0096 PG 9 WC Chemistry, Inorganic & Nuclear; Chemistry, Physical SC Chemistry GA UA976 UT WOS:A1996UA97600025 ER PT J AU Myatt, CJ Newbury, NR Ghrist, RW Loutzenhiser, S Wiemann, CE AF Myatt, CJ Newbury, NR Ghrist, RW Loutzenhiser, S Wiemann, CE TI Multiply loaded magneto-optical trap SO OPTICS LETTERS LA English DT Article ID VAPOR-CELL; ATOMS AB We report a two-chambered, differentially pumped system that permits rapid collection of trapped atoms with a vapor cell magneto-optical trap (MOT) and efficient transfer of these atoms to a second MOT in a lower-pressure chamber. During the transfer the atoms are guided down a long, thin tube by a magnetic potential, with 90(15%) transfer efficiency. By multiply loading, we accumulate and hold as many as 30 times the number collected by the vapor cell MOT. By thus separating the collection and holding functions of a MOT, we can collect as many as 1.5(0.6) x 10(10) rubidium atoms and hold them for longer than 100 s, using inexpensive low-power diode lasers. C1 UNIV COLORADO,DEPT PHYS,BOULDER,CO 80309. RP Myatt, CJ (reprint author), NATL INST STAND & TECHNOL,JOINT INST LAB ASTROPHYS,BOULDER,CO 80309, USA. NR 15 TC 109 Z9 110 U1 0 U2 7 PU OPTICAL SOC AMER PI WASHINGTON PA 2010 MASSACHUSETTS AVE NW, WASHINGTON, DC 20036 SN 0146-9592 J9 OPT LETT JI Opt. Lett. PD FEB 15 PY 1996 VL 21 IS 4 BP 290 EP 292 DI 10.1364/OL.21.000290 PG 3 WC Optics SC Optics GA TV855 UT WOS:A1996TV85500020 PM 19865382 ER PT J AU Pechik, I Ji, XH Fidelis, K Karavitis, M Moult, J Brinigar, WS Fronticelli, C Gilliland, GL AF Pechik, I Ji, XH Fidelis, K Karavitis, M Moult, J Brinigar, WS Fronticelli, C Gilliland, GL TI Crystallographic, molecular modeling, and biophysical characterization of the Valine(beta 67) (E11)->threonine variant of hemoglobin SO BIOCHEMISTRY LA English DT Article ID SITE-DIRECTED MUTAGENESIS; SPERM WHALE MYOGLOBIN; SEQUENCE-SPECIFIC PROTEOLYSIS; RECOMBINANT HUMAN HEMOGLOBIN; DISTAL POCKET POLARITY; LIGAND-BINDING; ESCHERICHIA-COLI; X-RAY; HEME POCKET; MACROMOLECULAR STRUCTURES AB The crystal structure of the mutant deoxyhemoglobin in which the beta-globin Val(67)(E11) has been replaced with threonine [Fronticelli et al. (1993) Biochemistry 32, 1235-1242] has been determined at 2.2 Angstrom resolution. Prior to the crystal structure determination, molecular modeling indicated that the Thr(67)(E11) side chain hydroxyl group in the distal beta-heme pocket forms a hydrogen bond with the backbone carbonyl of His(63)(E7) and is within hydrogen-bonding distance of the N-delta of His(63)(E7). The mutant crystal structure indicates only small changes in conformation in the vicinity of the Ell mutation confirming the molecular modeling predictions. Comparison of the structures of the mutant beta-subunits and recombinant porcine myoglobin with the identical mutation [Cameron et al. (1993) Biochemistry 32, 13061-13070] indicates similar conformations of residues in the distal heme pocket, but there is no water molecule associated with either of the threonines of the beta-subunits. The introduction of threonine into the distal heme pocket, despite having only small perturbations in the local structure, has a marked affect on the interaction with ligands. In the oxy derivative there is a 2-fold decrease in O-2 affinity [Fronticelli et al. (1993) Biochemistry 32, 1235-1242], and the rate of autoxidation is increased by 2 orders of magnitude. In the CO derivative the IR spectrum shows modifications with respect to that of normal human hemoglobin, suggesting the presence of multiple CO conformers. In the nitrosyl derivative an interaction with the O-gamma atom of Thr(67)(E11) is probably responsible for the 10-fold increase in the rate of NO release from the beta-subunits. In the aquomet derivative there is a 6-fold decrease in the rate of hemin dissociation suggesting an interaction of the Fe-coordinated water with the O-gamma of Thr(67)(E11). C1 UNIV MARYLAND,SCH MED,DEPT BIOCHEM,BALTIMORE,MD 21201. UNIV MARYLAND,INST BIOTECHNOL,CTR ADV RES BIOTECHNOL,ROCKVILLE,MD 20850. NIST,ROCKVILLE,MD 20850. TEMPLE UNIV,DEPT CHEM,PHILADELPHIA,PA 19122. LAWRENCE LIVERMORE NATL LAB,BIOL & BIOTECHNOL RES PROGRAM,LIVERMORE,CA 94551. RI Ji, Xinhua/C-9664-2012 OI Ji, Xinhua/0000-0001-6942-1514 FU NHLBI NIH HHS [HLBI-48517] NR 50 TC 17 Z9 17 U1 0 U2 3 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 SN 0006-2960 J9 BIOCHEMISTRY-US JI Biochemistry PD FEB 13 PY 1996 VL 35 IS 6 BP 1935 EP 1945 DI 10.1021/bi9519967 PG 11 WC Biochemistry & Molecular Biology SC Biochemistry & Molecular Biology GA TV600 UT WOS:A1996TV60000029 PM 8639677 ER PT J AU Martinis, JM AF Martinis, JM TI Hot-electron-microcalorimeters with 0.25 mm(2) area SO NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH SECTION A-ACCELERATORS SPECTROMETERS DETECTORS AND ASSOCIATED EQUIPMENT LA English DT Article; Proceedings Paper CT 6th International Workshop on Low Temperature Detectors (LTD6) CY AUG 28-SEP 01, 1995 CL BEATENBERG, SWITZERLAND SP Beer Brawand Fdn, Bern AB I present measurements on hot-electron microcalorimeter with a normal-insulator superconductor tunnel-junction thermometer that is used for the detection of X-rays. With an absorber area of 0.5 mm by 0.5 mm, pulses of 20 mu s in duration were observed that gave a 30 eV FWHM resolution for 6 keV X-rays and an 18 eV resolution for heat pulses. This detector has sufficient resolution, detector area, and speed to warrant application in materials analysis. RP Martinis, JM (reprint author), NATL INST STAND & TECHNOL,MS 81403,325 BROADWAY,BOULDER,CO 80303, USA. NR 5 TC 11 Z9 11 U1 0 U2 0 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0168-9002 J9 NUCL INSTRUM METH A JI Nucl. Instrum. Methods Phys. Res. Sect. A-Accel. Spectrom. Dect. Assoc. Equip. PD FEB 11 PY 1996 VL 370 IS 1 BP 171 EP 172 DI 10.1016/0168-9002(95)01073-4 PG 2 WC Instruments & Instrumentation; Nuclear Science & Technology; Physics, Nuclear; Physics, Particles & Fields SC Instruments & Instrumentation; Nuclear Science & Technology; Physics GA UA324 UT WOS:A1996UA32400057 ER PT J AU Irwin, KD Hilton, GC Martinis, JM Cabrera, B AF Irwin, KD Hilton, GC Martinis, JM Cabrera, B TI A hot-electron microcalorimeter for X-ray detection using a superconducting transition edge sensor with electrothermal feedback SO NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH SECTION A-ACCELERATORS SPECTROMETERS DETECTORS AND ASSOCIATED EQUIPMENT LA English DT Article; Proceedings Paper CT 6th International Workshop on Low Temperature Detectors (LTD6) CY AUG 28-SEP 01, 1995 CL BEATENBERG, SWITZERLAND SP Beer Brawand Fdn, Bern AB We investigate a hot-electron microcalorimeter for X-ray detection. The X-ray absorber consists of a normal metal film in thermal and electrical contact with a superconducting transition-edge sensor. The sensor is formed by a proximity-effect bilayer of aluminum and silver, with a sharp superconducting transition near 100 mK. Energy from X-rays absorbed in the normal film is removed by a reduction of the Joule heating in the proximity bilayer due to electrothermal feedback and measured using a SQUID. The feedback mode of operation allows the measurement of incident energy with no free parameters and should lead to improvement in detector resolution over existing hot-electron microcalorimeters. C1 NATL INST STAND & TECHNOL,BOULDER,CO 80303. RP Irwin, KD (reprint author), STANFORD UNIV,DEPT PHYS,STANFORD,CA 94305, USA. NR 9 TC 36 Z9 37 U1 1 U2 4 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0168-9002 J9 NUCL INSTRUM METH A JI Nucl. Instrum. Methods Phys. Res. Sect. A-Accel. Spectrom. Dect. Assoc. Equip. PD FEB 11 PY 1996 VL 370 IS 1 BP 177 EP 179 DI 10.1016/0168-9002(95)01076-9 PG 3 WC Instruments & Instrumentation; Nuclear Science & Technology; Physics, Nuclear; Physics, Particles & Fields SC Instruments & Instrumentation; Nuclear Science & Technology; Physics GA UA324 UT WOS:A1996UA32400059 ER PT J AU Nam, SW Cabrera, B Chugg, B Clarke, RM Fertig, C Irwin, KD Young, BA AF Nam, SW Cabrera, B Chugg, B Clarke, RM Fertig, C Irwin, KD Young, BA TI SQUID based W-Al quasiparticle trapping assisted transition edge sensor SO NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH SECTION A-ACCELERATORS SPECTROMETERS DETECTORS AND ASSOCIATED EQUIPMENT LA English DT Article; Proceedings Paper CT 6th International Workshop on Low Temperature Detectors (LTD6) CY AUG 28-SEP 01, 1995 CL BEATENBERG, SWITZERLAND SP Beer Brawand Fdn, Bern AB We have demonstrated a new type of phonon sensor for cryogenic particle detectors with a high-bandwidth SQUID readout. Our Quasiparticle trapping assisted Electrothermal feedback Transition edge sensor (QET) utilizes aluminum quasiparticle traps attached to a tungsten superconducting transition edge sensor patterned on a silicon substrate. The tungsten lines are voltage biased and self-regulate in the transition region. We have tested three versions of these detectors. One detector consisted of four QET sensors patterned on the surface of a 1 cm x 1 cm x 1 mm silicon substrate. With this detector, we have shown an energy resolution of similar to 400 eV FWHM and position sensitivity of similar to 0.3 mm for 6 keV X-rays from an Fe-55 source. We tested a second detector identical to the first but with the addition of an ionization sensor. With information from the ionization channel, we were able to distinguish electron-recoil events from nuclear-recoil events. Most recently, we have tested a 2 cm x 2 cm x 2 mm detector with four QET sensors. C1 NIST,BOULDER,CO. UNIV SANTA CLARA,DEPT PHYS,SANTA CLARA,CA 95053. RP Nam, SW (reprint author), STANFORD UNIV,DEPT PHYS,STANFORD,CA 94305, USA. NR 9 TC 25 Z9 25 U1 0 U2 1 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0168-9002 J9 NUCL INSTRUM METH A JI Nucl. Instrum. Methods Phys. Res. Sect. A-Accel. Spectrom. Dect. Assoc. Equip. PD FEB 11 PY 1996 VL 370 IS 1 BP 187 EP 189 DI 10.1016/0168-9002(95)01083-1 PG 3 WC Instruments & Instrumentation; Nuclear Science & Technology; Physics, Nuclear; Physics, Particles & Fields SC Instruments & Instrumentation; Nuclear Science & Technology; Physics GA UA324 UT WOS:A1996UA32400062 ER PT J AU Snay, RA Cline, MW Philipp, CR Jackson, DD Feng, YJ Shen, ZK Lisowski, M AF Snay, RA Cline, MW Philipp, CR Jackson, DD Feng, YJ Shen, ZK Lisowski, M TI Crustal velocity field near the big bend of California's San Andreas fault SO JOURNAL OF GEOPHYSICAL RESEARCH-SOLID EARTH LA English DT Article ID WESTERN TRANSVERSE RANGES; GLOBAL POSITIONING SYSTEM; SOUTHERN CALIFORNIA; REGIONAL DEFORMATION; GEODETIC MEASUREMENT; VENTURA-BASIN; EARTH MODEL; KERN COUNTY; STRAIN; PLATE AB We use geodetic data spanning the 1920-1992 interval to estimate the horizontal velocity field near the big bend segment of California's San Andreas fault (SAF). More specifically, we estimate a horizontal velocity vector for each node of a two-dimensional grid that has a 15-min-by-15-min mesh and that extends between latitudes 34.0 degrees N and 36.0 degrees N and longitudes 117.5 degrees W and 120.5 degrees W. For this estimation process, we apply bilinear interpolation to transfer crustal deformation information from geodetic sites to the grid nodes. The data include over a half century of triangulation measurements, over two decades of repeated electronic distance measurements, a decade of repeated very long baseline interferometry measurements, and several years of Global Positioning System measurements. Magnitudes for our estimated velocity vectors have formal standard errors ranging from 0.7 to 6.8 mm/yr. Our derived velocity field shows that (1) relative motion associated with the SAF exceeds 30 mm/yr and is distributed on the Earth's surface across a band (>100 km wide) that is roughly centered on this fault; (2) when velocities are expressed relative to a fixed North America plate, the motion within our primary study region has a mean orientation of N44 degrees W +/- 2 degrees and the surface trace of the SAF is congruent in shape to nearby contours of constant speed yet this trace is oriented between 5 degrees and 10 degrees counterclockwise relative to these contours; and (3) large strain rates (shear rates > 150 nrad/yr and/or areal dilatation rates < -150 nstr/yr) exist near the Garlock fault, near the White Wolf fault, and in the Ventura basin. C1 UNIV CALIF LOS ANGELES, DEPT EARTH & SPACE SCI, LOS ANGELES, CA 90024 USA. US GEOL SURVEY, HAWAIIAN VOLCANO OBSERV, HILO, HI 96718 USA. RP Snay, RA (reprint author), NOAA, NATL GEODET SURVEY, 1315 EW HIGHWAY, SILVER SPRING, MD 20910 USA. NR 54 TC 19 Z9 19 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 FEB 10 PY 1996 VL 101 IS B2 BP 3173 EP 3185 DI 10.1029/95JB02394 PG 13 WC Geochemistry & Geophysics SC Geochemistry & Geophysics GA TV380 UT WOS:A1996TV38000029 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 .5. Heavier ethane- and ethene-based compounds SO JOURNAL OF CHROMATOGRAPHY A LA English DT Article DE relative retention; refrigerants, alternative; halocarbons AB The retention characteristics of thirteen heavier ethane-based and eight ethene-based 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, and 60 degrees C for R-152, and at 20, 40, 60, and 80 degrees C for R-124. Measurements were performed at 40, 60, 80, and 100 degrees C for R-123a, R-152, and R-115I-1, and at 60, 80, 100 and 120 for R-132b and R-1130a, R-1121 (cis), and R-1121 (trans). Measurements were performed at 80, 100, 120 and 140 degrees C for R-113, R-123B1, R-141, R-1130 (cis), and R-1130 (trans). Measurements were performed at 100, 120, !40, and 160 degrees C for R-113a, R-121, R-122, R-131, R-131a, R-1110, R-1111, and R-1120. 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 18 TC 3 Z9 3 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 FEB 9 PY 1996 VL 723 IS 2 BP 325 EP 335 DI 10.1016/0021-9673(95)00887-X PG 11 WC Biochemical Research Methods; Chemistry, Analytical SC Biochemistry & Molecular Biology; Chemistry GA TX078 UT WOS:A1996TX07800012 ER PT J AU Sperhac, JM Weida, MJ Nesbitt, DJ AF Sperhac, JM Weida, MJ Nesbitt, DJ TI Infrared spectroscopy of Ar2CO2 trimer: Vibrationally averaged structures, solvent shifts, and three-body effects SO JOURNAL OF CHEMICAL PHYSICS LA English DT Article ID TO-STATE LEVEL; ABSORPTION SPECTROSCOPY; ROTATIONAL SPECTRA; POTENTIAL SURFACE; CARBON-DIOXIDE; MICROWAVE SPECTROSCOPY; VANDERWAALS COMPLEXES; LASER SPECTROSCOPY; PROPENSITY RULES; MU-M AB Ar2CO2 is studied using direct absorption infrared spectroscopy. The van der Waals molecules are formed when a mixture of CO2 and Ar gases is expanded in a supersonic slit jet. To probe the clusters, the nu(3) asymmetric stretch of the CO2 monomer is then monitored in absorption. Sixty-one trimer transitions are assigned and fit to a Watson asymmetric top Hamiltonian. Rotational constants for the upper and lower vibrational states permit determination of vibrationally averaged molecular structures, which indicate that the Ar atoms lie in the plane that bisects CO2 and is perpendicular to the CO2 intramolecular axis. These geometries are consistent with an equivalent ''T-shaped'' ArCO2 geometry for each Ar atom. Vibrational origins for the nu(3) CO2 asymmetric stretch frequency in ArnCO2 are found to shift approximately linearly for zero, one, and two Ar atoms. Calculations using pair potentials are used to extrapolate these red shifts out to the bulk phase and to compare the results to experimental matrix data. Finally, the slight nonlinearity in the red shift between ArCO2 dimer and Ar2CO2 trimers is interpreted in the context of three-body forces. (C) 1996 American Institute of Physics. C1 UNIV COLORADO,NATL INST STAND & TECHNOL,PHYS QUANT DIV,BOULDER,CO 80309. UNIV COLORADO,DEPT CHEM & BIOCHEM,BOULDER,CO 80309. RP Sperhac, JM (reprint author), UNIV COLORADO,JOINT INST LAB ASTROPHYS,BOULDER,CO 80309, USA. NR 56 TC 34 Z9 34 U1 0 U2 3 PU AMER INST PHYSICS PI WOODBURY PA CIRCULATION FULFILLMENT DIV, 500 SUNNYSIDE BLVD, WOODBURY, NY 11797-2999 SN 0021-9606 J9 J CHEM PHYS JI J. Chem. Phys. PD FEB 8 PY 1996 VL 104 IS 6 BP 2202 EP 2213 DI 10.1063/1.470918 PG 12 WC Chemistry, Physical; Physics, Atomic, Molecular & Chemical SC Chemistry; Physics GA TU447 UT WOS:A1996TU44700009 ER PT J AU Brown, JW Wladkowski, BD AF Brown, JW Wladkowski, BD TI Ab initio studies of the exocyclic hydroxymethyl rotational surface in alpha-D-glucopyranose SO JOURNAL OF THE AMERICAN CHEMICAL SOCIETY LA English DT Article ID MOLECULAR-ORBITAL METHODS; VALENCE BASIS-SETS; CONFORMATIONAL-ANALYSIS; 1ST-ROW ELEMENTS; 2ND-ROW ELEMENTS; D-GLUCOSE; ENERGIES; DYNAMICS AB The potential energy surface for rotation of the exocyclic hydroxymethyl group of alpha-D-glucopyranose has been studied using ab initio quantum mechanical methods. Relevant stationary points, including for the first time rotational transition states, have been characterized by full geometry optimization using basis sets ranging in quality from 6-31G(d) to 6-311(2d,1p). Effects of dynamical electron correlation on both the geometric structures and the energy surface are also investigated using second-order Moller-Plesset perturbation theory (MP2) and density functional methods (BLYP). A total of six stationary points along the hydroxymethyl rotational surface, including three minima and three transition states, were identified. The effects of basis set augmentation and electron correlation on the relative energies are small; the relative energies for each stationary point vary by less than 5 kJ mol(-1) for all levels of theory considered. Final energetic barriers to hydroxymethyl rotation ranged from 15 to 29 kJ mol(-1) Differences between these barriers and previously reported ab initio results on a carbohydrate model compound, 2-(hydroxymethyl)tetrahydropyran, as well as energies calculated using force field methods, are discussed. C1 WESTERN MARYLAND COLL,DEPT CHEM,WESTMINSTER,MD 21157. RP Brown, JW (reprint author), NIST,CTR ADV RES BIOTECHNOL,9600 GUDELSKY DR,ROCKVILLE,MD 20850, USA. NR 26 TC 57 Z9 57 U1 0 U2 5 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 SN 0002-7863 J9 J AM CHEM SOC JI J. Am. Chem. Soc. PD FEB 7 PY 1996 VL 118 IS 5 BP 1190 EP 1193 DI 10.1021/ja952804y PG 4 WC Chemistry, Multidisciplinary SC Chemistry GA TU348 UT WOS:A1996TU34800035 ER PT J AU Dittberner, G Gird, R Heymann, R Howard, E Kirkner, S Uccellini, L AF Dittberner, G Gird, R Heymann, R Howard, E Kirkner, S Uccellini, L TI NOAA's future earth observations from advanced GOES satellites SO ACTA ASTRONAUTICA LA English DT Article; Proceedings Paper CT 46th International-Astronautical-Federation Congress CY OCT 02-06, 1995 CL OSLO, NORWAY SP Int Astronaut Federat AB This paper describes early progress made toward defining the next generation of GOES satellites. These satellites could be first launched in 2008. The paper is divided into four main sections. First, the actual process of starting a new satellite program is presented as it has occurred during the past two years. NOAA formed 12 internal teams to determine requirements and will contract with industry soon for feasibility studies. This real process in a complex agency and with many potential users is compared with the classic textbook approaches recommended for new program space starts by NASA/NOAA. These early results of requirements for GOES R are presented as the second section. Imager and sounder instruments currently on GOES are improved considerably. New instruments such as passive microwave, lightning mapper and ocean color are described. Finally, even new spacecraft configurations and more reliance on industry/government partnerships are suggested. Section three offers ideas about new spacecraft configurations for GOES N. These include both larger payload sizes or lighter payloads that might fly on lighter spacecraft. In addition, the use of commercial satellites for NOAA measurements is suggested. The fourth section gives advantages of geosynchronous orbit and the need for international participation in future gee-satellite missions. In a broader sense geo measurements will benefit the world and we welcome immediate and practical participation of interested parties in our planning. C1 US DEPT COMMERCE,NOAA,WASHINGTON,DC 20233. NR 15 TC 0 Z9 0 U1 1 U2 1 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD, ENGLAND OX5 1GB SN 0094-5765 J9 ACTA ASTRONAUT JI Acta Astronaut. PD FEB-APR PY 1996 VL 38 IS 4-8 BP 467 EP 477 DI 10.1016/0094-5765(96)00021-5 PG 11 WC Engineering, Aerospace SC Engineering GA VJ682 UT WOS:A1996VJ68200025 ER PT J AU FischerCripps, AC Lawn, BR AF FischerCripps, AC Lawn, BR TI Indentation stress-strain curves for ''quasi-ductile'' ceramics SO ACTA MATERIALIA LA English DT Article ID BRITTLE SOLIDS; FAILURE; COMPRESSION; RESISTANCE; GROWTH AB A micromechanical model describing ''quasi-ductile'' Hertzian contacts in otherwise brittle ceramics is developed. The elemental basis of the model is a discrete ''fault'' along an internal weak interface, constrained at its ends by an elastic matrix and subject to frictional sliding, in the subsurface zone of high shear stress in the Hertzian field. By summation over a prescribed density of shear faults within the active plastic zone, the analysis leads to a constitutive indentation stress-strain function, with special provision for the incorporation of microstructural variables. Experimental data from a series of mica-containing glass-ceramics with contiguous platelet microstructures are used to confirm the essential predictions of the model. It is demonstrated that plasticity increases with volume Fraction and aspect ratio, but not size, of the platelets. Parametric evaluations by curve fitting the indentation stress-strain data allow for predictions of intrinsic stress-strain responses for the glass-ceramics in conventional uniform stressing states. RP NIST, MAT SCI & ENGN LAB, GAITHERSBURG, MD 20899 USA. NR 40 TC 70 Z9 71 U1 0 U2 5 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLAND SN 1359-6454 EI 1873-2453 J9 ACTA MATER JI Acta Mater. PD FEB PY 1996 VL 44 IS 2 BP 519 EP 527 DI 10.1016/1359-6454(95)00204-9 PG 9 WC Materials Science, Multidisciplinary; Metallurgy & Metallurgical Engineering SC Materials Science; Metallurgy & Metallurgical Engineering GA TY679 UT WOS:A1996TY67900011 ER PT J AU Schwartz, LH AF Schwartz, LH TI Industry, government, university cooperation: New roles in a changing world SO ADVANCED MATERIALS & PROCESSES LA English DT Article RP Schwartz, LH (reprint author), NATL INST STAND & TECHNOL,MAT SCI & ENGN LAB,325 BROADWAY,BOULDER,CO 80303, USA. NR 2 TC 0 Z9 0 U1 0 U2 0 PU ASM INTERNATIONAL PI MATERIALS PARK PA SUBSCRIPTIONS SPECIALIST CUSTOMER SERVICE, MATERIALS PARK, OH 44073-0002 SN 0026-0665 J9 ADV MATER PROCESS JI Adv. Mater. Process. PD FEB PY 1996 VL 149 IS 2 BP 110 EP 116 PG 7 WC Materials Science, Multidisciplinary SC Materials Science GA UL030 UT WOS:A1996UL03000013 ER PT J AU Vangel, MG AF Vangel, MG TI Confidence intervals for a normal coefficient of variation SO AMERICAN STATISTICIAN LA English DT Article DE chi-squared approximation; noncentral t distribution; McKay's approximation AB This article presents an analysis of the small-sample distribution of a class of approximate pivotal quantities for a normal coefficient of variation that contains the approximations of McKay, David, the ''naive'' approximate interval obtained by dividing the usual confidence interval on the standard deviation by the sample mean, and a new interval closely related to McKay. For any approximation in this class, a series is given for e(t), the difference between the cdf's of the approximate pivot and the reference distribution. Let ii denote the population coefficient of variation. For McKay, David, and the ''naive'' interval e(t) = O(k(2)), while for the new procedure e(t) = O(k(4)). C1 USA,RES LAB,WATERTOWN,MA 02172. RP Vangel, MG (reprint author), NIST,DIV STAT ENGN,GAITHERSBURG,MD 20899, USA. NR 7 TC 73 Z9 73 U1 2 U2 8 PU AMER STATIST ASSN PI ALEXANDRIA PA 1429 DUKE ST, ALEXANDRIA, VA 22314 SN 0003-1305 J9 AM STAT JI Am. Stat. PD FEB PY 1996 VL 50 IS 1 BP 21 EP 26 DI 10.2307/2685039 PG 6 WC Statistics & Probability SC Mathematics GA UN109 UT WOS:A1996UN10900005 ER PT J AU Winchester, MR AF Winchester, MR TI Optically induced analytical error in glow discharge optical emission spectrometry SO APPLIED SPECTROSCOPY LA English DT Article DE glow discharge; optical emission spectrometry; analytical error; transfer optics AB It is shown that the common practice of imaging the plasma directly onto the spectrometer entrance slit in analytical glow discharge optical emission spectrometry (GDOES) may induce analytical error when used with samples which are chemically heterogeneous. An alternative method for transferring the source emission to the entrance slit is demonstrated to eliminate the potential error, suggesting its routine use in analytical GDOES. RP Winchester, MR (reprint author), NIST,CHEM SCI & TECHNOL LAB,DIV ANALYT CHEM,GAITHERSBURG,MD 20899, USA. NR 8 TC 3 Z9 3 U1 0 U2 1 PU SOC APPLIED SPECTROSCOPY PI FREDERICK PA PO BOX 1438, FREDERICK, MD 21701 SN 0003-7028 J9 APPL SPECTROSC JI Appl. Spectrosc. PD FEB PY 1996 VL 50 IS 2 BP 245 EP 251 DI 10.1366/0003702963906492 PG 7 WC Instruments & Instrumentation; Spectroscopy SC Instruments & Instrumentation; Spectroscopy GA TV879 UT WOS:A1996TV87900018 ER PT J AU Madau, P Shull, JM AF Madau, P Shull, JM TI Cosmic metal production and the contribution of QSO absorption systems to the ionizing background SO ASTROPHYSICAL JOURNAL LA English DT Article DE cosmology, observations; diffuse radiation; intergalactic medium; quasars, absorption lines ID LYMAN-ALPHA CLOUDS; HIGH-REDSHIFT; LINE SYSTEMS; ORIGIN; LIMIT; GALAXIES; PHOTOIONIZATION; POPULATIONS; RADIATION; SPECTRA AB The recent discovery by Cowie et al. (1995) and Tytler et al. (1995) of metals in the Ly alpha clouds shows that the intergalactic medium (IGM) at high redshift is contaminated by the products of stars and suggests that ionizing photons from massive star formation may be a significant contributor to the UV background radiation at early epochs. We assess the validity of the stellar photoionization hypothesis. Based on recent computations of metal yields and O-star Lyman continuum (Lyc) fluxes, we find that 0.2% of the rest-mass energy of the metals produced is radiated as Lye. By modeling the transfer of ionizing radiation through the IGM and the rate of chemical enrichment, we demonstrate that the background intensity of photons at 1 ryd that accompanies the production of metals in the Ly alpha forest clouds may be significant, approaching 0.5 x 10(-21) ergs cm(-2) s(-1) Hz(-1) sr(-1) at z approximate to 3 if the Lyc escape fraction is greater than or similar to 0.25. Together with quasars, massive stars could then, in principle, provide the hydrogen and helium Lye photons required to ionize the universe at high redshifts. We propose that observations of the He II Gunn-Peterson effect and of the metal ionization states of the Lye forest and Lyman-limit absorbers should show the signature of a stellar spectrum. We also note that the stellar photoionization model fails if a large fraction of the UV radiation emitted from stars cannot escape into the IGM, as suggested by the recent Hopkins Ultraviolet Telescope observations by Leitherer et al. (1995) of low-redshift starburst galaxies, or if most of the metals observed at z x 3 were produced at much earlier epochs. C1 UNIV COLORADO, JOINT INST LAB ASTROPHYS, BOULDER, CO 80309 USA. NATL INST STAND & TECHNOL, BOULDER, CO 80309 USA. UNIV COLORADO, CTR ASTROPHYS & SPACE ASTRON, DEPT ASTROPHYS PLANETARY & ATMOSPHER SCI, BOULDER, CO 80309 USA. RP Madau, P (reprint author), SPACE TELESCOPE SCI INST, 3700 SAN MARTIN DR, BALTIMORE, MD 21218 USA. NR 55 TC 76 Z9 76 U1 0 U2 0 PU IOP PUBLISHING LTD PI BRISTOL PA TEMPLE CIRCUS, TEMPLE WAY, BRISTOL BS1 6BE, ENGLAND SN 0004-637X J9 ASTROPHYS J JI Astrophys. J. PD FEB 1 PY 1996 VL 457 IS 2 BP 551 EP 556 DI 10.1086/176751 PN 1 PG 6 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA TQ546 UT WOS:A1996TQ54600007 ER PT J AU Conny, JM Currie, LA AF Conny, JM Currie, LA TI The isotopic characterization of methane, non-methane hydrocarbons and formaldehyde in the troposphere SO ATMOSPHERIC ENVIRONMENT LA English DT Review DE stable isotopes; radioactive isotopes; isotope fractionation; kinetic isotope effect; trace gases ID GAS-PHASE REACTION; ATMOSPHERIC METHANE; CARBON ISOTOPES; AIR PHOTOOXIDATIONS; SEASONAL-VARIATIONS; OXIDIZING BACTERIA; OXIDATION-PRODUCTS; ORGANIC-COMPOUNDS; BIOGENIC METHANE; CO2 REDUCTION AB Interest in the isotopic composition of trace species in the troposphere continues to increase because of the utility of isotopic information for interpreting timely concerns such as the effects of climate change, O-3 production and OH depletion. With the exception of CO2, isotopic information has served, to a large extent, only an ancillary role in determining global cycles of trace species, including their chemistries. Often, isotopic information is only used to interpret isolated parts of atmospheric cycles. For example, hydrogen and carbon isotopic ratios of CH4 source emissions have been used to help quantify source contributions to the global CH4 budget. Less emphasis has been placed on isotopic information for interpreting the atmospheric cycling of CH4 and non-methane hydrocarbons (NMHCs) to formaldehyde and CO. Here, we review compositions of the stable isotopes (C-13 and H-2) and radioactive isotopes (C-14 and H-3) for the various hydrocarbon components and formaldehyde in the tropospheric hydrocarbon-OH-CO system. Included are isotopic ratios of CH4 and NMHCs at sources and in ambient air as well as isotope effects during chemical transformation. Variations in the data are discussed with respect to measurement uncertainty and natural variation. Emphasis is on multi-isotopic signatures, for example,C-13/C-12 and D/H ratios and C-14 activities for individual CH4 sources. RP Conny, JM (reprint author), NIST,CHEM SCI & TECHNOL LAB,SURFACE & MICROANAL SCI DIV,ATMOSPHER CHEM GRP,CHEM B364,GAITHERSBURG,MD 20899, USA. NR 112 TC 42 Z9 44 U1 3 U2 20 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 FEB PY 1996 VL 30 IS 4 BP 621 EP 638 DI 10.1016/1352-2310(95)00305-3 PG 18 WC Environmental Sciences; Meteorology & Atmospheric Sciences SC Environmental Sciences & Ecology; Meteorology & Atmospheric Sciences GA TM513 UT WOS:A1996TM51300009 ER PT J AU Antosiewicz, J McCammon, JA Gilson, MK AF Antosiewicz, J McCammon, JA Gilson, MK TI Prediction of protein PKAS: Influence of parameters upon accuracy for four proteins. SO BIOPHYSICAL JOURNAL LA English DT Meeting Abstract C1 UNIV WARSAW,PL-00325 WARSAW,POLAND. UNIV CALIF SAN DIEGO,SAN DIEGO,CA 92103. NIST,CTR ADV RES BIOTECHNOL,ROCKVILLE,MD 20850. RI Antosiewicz, Jan/G-1308-2011 NR 0 TC 0 Z9 0 U1 0 U2 1 PU BIOPHYSICAL SOCIETY PI BETHESDA PA 9650 ROCKVILLE PIKE, BETHESDA, MD 20814-3998 SN 0006-3495 J9 BIOPHYS J JI Biophys. J. PD FEB PY 1996 VL 70 IS 2 BP M0413 EP M0413 PN 2 PG 1 WC Biophysics SC Biophysics GA TZ682 UT WOS:A1996TZ68201295 ER PT J AU Kasianowicz, JJ Brandin, E Branton, D Deamer, DW AF Kasianowicz, JJ Brandin, E Branton, D Deamer, DW TI Characterization of individual nucleic acid polymers with an ion channel. SO BIOPHYSICAL JOURNAL LA English DT Meeting Abstract C1 NIST,GAITHERSBURG,MD 20899. UNIV CALIF SANTA CRUZ,SANTA CRUZ,CA 95064. HARVARD UNIV,CAMBRIDGE,MA 02138. NR 0 TC 0 Z9 0 U1 2 U2 7 PU BIOPHYSICAL SOCIETY PI BETHESDA PA 9650 ROCKVILLE PIKE, BETHESDA, MD 20814-3998 SN 0006-3495 J9 BIOPHYS J JI Biophys. J. PD FEB PY 1996 VL 70 IS 2 BP MPO26 EP MPO26 PN 2 PG 1 WC Biophysics SC Biophysics GA TZ682 UT WOS:A1996TZ68200910 ER PT J AU Kasianowicz, JJ Bezrukov, SM AF Kasianowicz, JJ Bezrukov, SM TI Solvent isotope substitution effects on the kinetics of amino acid residue ionization in the alpha-toxin channel SO BIOPHYSICAL JOURNAL LA English DT Meeting Abstract C1 NIST,DIV BIOTECHNOL,GAITHERSBURG,MD 20899. NIH,DORT,BETHESDA,MD 20892. NR 0 TC 0 Z9 0 U1 0 U2 2 PU BIOPHYSICAL SOCIETY PI BETHESDA PA 9650 ROCKVILLE PIKE, BETHESDA, MD 20814-3998 SN 0006-3495 J9 BIOPHYS J JI Biophys. J. PD FEB PY 1996 VL 70 IS 2 BP SU278 EP SU278 PN 2 PG 1 WC Biophysics SC Biophysics GA TZ682 UT WOS:A1996TZ68200461 ER PT J AU Given, JA Gilson, MK AF Given, JA Gilson, MK TI A systematic approach to the development and validation of models for protein ligand binding. SO BIOPHYSICAL JOURNAL LA English DT Meeting Abstract C1 NIST,CTR ADV RES BIOTECHNOL,ROCKVILLE,MD 20850. NR 0 TC 0 Z9 0 U1 0 U2 0 PU BIOPHYSICAL SOCIETY PI BETHESDA PA 9650 ROCKVILLE PIKE, BETHESDA, MD 20814-3998 SN 0006-3495 J9 BIOPHYS J JI Biophys. J. PD FEB PY 1996 VL 70 IS 2 BP TUAM9 EP TUAM9 PN 2 PG 1 WC Biophysics SC Biophysics GA TZ682 UT WOS:A1996TZ68201427 ER PT J AU Robertson, B Weetall, HH AF Robertson, B Weetall, HH TI Theory of rapid pH change due to bacteriorhodopsin measured with a tin-oxide electrode. SO BIOPHYSICAL JOURNAL LA English DT Meeting Abstract C1 NIST,GAITHERSBURG,MD 20899. NR 0 TC 1 Z9 1 U1 0 U2 1 PU BIOPHYSICAL SOCIETY PI BETHESDA PA 9650 ROCKVILLE PIKE, BETHESDA, MD 20814-3998 SN 0006-3495 J9 BIOPHYS J JI Biophys. J. PD FEB PY 1996 VL 70 IS 2 BP TUAM4 EP TUAM4 PN 2 PG 1 WC Biophysics SC Biophysics GA TZ682 UT WOS:A1996TZ68201398 ER PT J AU Ross, PD Rekharsky, MV AF Ross, PD Rekharsky, MV TI Thermodynamic comparison of a hydrogen bond and a hydrophobic interaction at a common site SO BIOPHYSICAL JOURNAL LA English DT Meeting Abstract C1 NIH,BETHESDA,MD 20892. NIST,GAITHERSBURG,MD 20899. NR 0 TC 1 Z9 1 U1 0 U2 1 PU BIOPHYSICAL SOCIETY PI BETHESDA PA 9650 ROCKVILLE PIKE, BETHESDA, MD 20814-3998 SN 0006-3495 J9 BIOPHYS J JI Biophys. J. PD FEB PY 1996 VL 70 IS 2 BP TU225 EP TU225 PN 2 PG 1 WC Biophysics SC Biophysics GA TZ682 UT WOS:A1996TZ68201745 ER PT J AU Given, JA Hubbard, JB Douglas, JF AF Given, JA Hubbard, JB Douglas, JF TI A first-passage algorithm for the hydrodynamic friction and diffusion-limited reaction rate of macromolecules. SO BIOPHYSICAL JOURNAL LA English DT Meeting Abstract C1 CTR ADV RES BIOTECHNOL,ROCKVILLE,MD 20850. NIST,GAITHERSBURG,MD 20899. NR 0 TC 0 Z9 0 U1 0 U2 0 PU BIOPHYSICAL SOCIETY PI BETHESDA PA 9650 ROCKVILLE PIKE, BETHESDA, MD 20814-3998 SN 0006-3495 J9 BIOPHYS J JI Biophys. J. PD FEB PY 1996 VL 70 IS 2 BP WAML2 EP WAML2 PN 2 PG 1 WC Biophysics SC Biophysics GA TZ682 UT WOS:A1996TZ68202177 ER PT J AU Koenig, BW Gawrisch, K Krueger, S Orts, W Majkrzak, CF Berk, N Silverton, JV AF Koenig, BW Gawrisch, K Krueger, S Orts, W Majkrzak, CF Berk, N Silverton, JV TI Membrane structure at the solid/water interface studied with neutron reflectivity and atomic force microscopy SO BIOPHYSICAL JOURNAL LA English DT Meeting Abstract C1 NIAAA,BETHESDA,MD 20892. NHLBI,NIH,BETHESDA,MD 20892. NIST,DIV REACTOR RADIAT,GAITHERSBURG,MD 20899. NR 0 TC 2 Z9 2 U1 0 U2 0 PU BIOPHYSICAL SOCIETY PI BETHESDA PA 9650 ROCKVILLE PIKE, BETHESDA, MD 20814-3998 SN 0006-3495 J9 BIOPHYS J JI Biophys. J. PD FEB PY 1996 VL 70 IS 2 BP WP229 EP WP229 PN 2 PG 1 WC Biophysics SC Biophysics GA TZ682 UT WOS:A1996TZ68202418 ER PT J AU Karl, TR Knight, RW Easterling, DR Quayle, RG AF Karl, TR Knight, RW Easterling, DR Quayle, RG TI Indices of climate change for the United States SO BULLETIN OF THE AMERICAN METEOROLOGICAL SOCIETY LA English DT Article ID SOUTHERN OSCILLATION; TEMPERATURE; PRECIPITATION; MAXIMUM; MINIMUM; MODEL; TIME AB A framework is presented to quantify observed changes in climate within the contiguous United States through the development and analysis of two indices of climate change, a Climate Extremes Index (CEI) and a U.S. Greenhouse Climate Response Index (GCRI). The CEI is based on an aggregate set of conventional climate extreme indicators, and the GCRI is composed of indicators that measure changes in the climate of the United States that have been projected to occur as a result of increased emissions of greenhouse gases. The CEI supports the notion that the climate of the United States has become more extreme in recent decades, yet the magnitude and persistence of the changes are not large enough at this point to conclude that the increase in extremes reflects a nonstationary climate. Nonetheless, if impacts due to extreme events rise exponentially with the index, then the increase may be quite significant in a practical sense. Similarly, the positive trend of the U.S. GCRI during the twentieth century is consistent with an enhanced greenhouse effect. The increase is unlikely to have arisen due to chance alone (there is about a 5% chance). Still, the increase of the GCRI is not large enough to unequivocally reject the possibility that the increase in the GCRI may be the result of other factors, including natural climate variability, and the similarity between the change in the GCRI and anticipated changes says little about the sensitivity of the climate system to the greenhouse effect. Both indices increased rather abruptly during the 1970s, a time of major circulation changes over the Pacific Ocean and North America. RP Karl, TR (reprint author), NOAA, NATL CLIMAT DATA CTR, 151 PATTON AVE, ASHEVILLE, NC 28801 USA. NR 37 TC 326 Z9 356 U1 4 U2 21 PU AMER METEOROLOGICAL SOC PI BOSTON PA 45 BEACON ST, BOSTON, MA 02108-3693 USA SN 0003-0007 J9 B AM METEOROL SOC JI Bull. Amer. Meteorol. Soc. PD FEB PY 1996 VL 77 IS 2 BP 279 EP 292 DI 10.1175/1520-0477(1996)077<0279:IOCCFT>2.0.CO;2 PG 14 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA UB904 UT WOS:A1996UB90400005 ER PT J AU Crum, T Carter, G AF Crum, T Carter, G TI Summary of the 14th Conference on Weather Analysis and Forecasting SO BULLETIN OF THE AMERICAN METEOROLOGICAL SOCIETY LA English DT Editorial Material C1 NOAA,NWS,EASTERN REG HEADQUARTERS,BOHEMIA,NY. RP Crum, T (reprint author), NOAA,NWS,OPERAT SUPPORT FACIL WSR88D,1200 WESTHEIMER DR,NORMAN,OK 73069, USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU AMER METEOROLOGICAL SOC PI BOSTON PA 45 BEACON ST, BOSTON, MA 02108-3693 SN 0003-0007 J9 B AM METEOROL SOC JI Bull. Amer. Meteorol. Soc. PD FEB PY 1996 VL 77 IS 2 BP 341 EP 352 PG 12 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA UB904 UT WOS:A1996UB90400010 ER PT J AU Cook, CA Cundy, VA Larsen, FL Lighty, JS AF Cook, CA Cundy, VA Larsen, FL Lighty, JS TI Comprehensive heat transfer model for rotary desorbers SO CANADIAN JOURNAL OF CHEMICAL ENGINEERING LA English DT Article DE thermal desorption; heat transfer processes; drying; soil remediation; contaminant desorption ID PETROLEUM COKE CALCINATION; KILN INCINERATION; DESORPTION; CONTAMINANTS; REMEDIATION; PARTICLE; DESIGN; SOLIDS; SOILS; RATES AB A model that describes the heat transfer processes within a rotary desorber is presented. This model has several advantages over previous models. The method for calculating the wall-to-bed heat transfer rate includes the effects of moisture in the feed solids and allows for evaporation from the bed before the bulk bed temperature reaches the saturation temperature of the moisture. The method for calculating radiative heat transfer in the desorber accounts for the real nature of the participating gas and the amounts of CO2 and H2O in the gas phase from both combustion and evaporation. Results from experiments performed using a pilot-scale desorber are discussed, and the model is validated by comparing the predicted bed temperature profiles and evaporation rates to those found experimentally. A preliminary attempt to account for the effects of a non-uniform bed on the evaporation rate from the bed is also presented along with several parametric studies. C1 MONTANA STATE UNIV,DEPT MECH & IND ENGN,BOZEMAN,MT 59717. NIST,GAITHERSBURG,MD 20899. UNIV UTAH,DEPT CHEM ENGN,SALT LAKE CITY,UT 84112. NR 40 TC 5 Z9 5 U1 2 U2 5 PU CANADIAN SOC CHEMICAL ENGINEERING PI OTTAWA PA 130 SLATER ST, STE 550, OTTAWA ON K1P 6E2, CANADA SN 0008-4034 J9 CAN J CHEM ENG JI Can. J. Chem. Eng. PD FEB PY 1996 VL 74 IS 1 BP 63 EP 76 PG 14 WC Engineering, Chemical SC Engineering GA UC531 UT WOS:A1996UC53100007 ER PT J AU Bigler, BS Welch, DW Helle, JH AF Bigler, BS Welch, DW Helle, JH TI A review of size trends among North Pacific salmon (Oncorhynchus spp) SO CANADIAN JOURNAL OF FISHERIES AND AQUATIC SCIENCES LA English DT Review ID CHUM SALMON; BRITISH-COLUMBIA; BODY SIZE; EGG SIZE; KETA; LIFE; AGE; MORPHOLOGY; OCEAN AB The abundance of North Pacific salmon (Oncorhynchus spp.) has nearly doubled during the period 1975-1993. As salmon population numbers have increased, there have been corresponding decreases in average adult size at return (maturity). As nearly all of the growth of Pacific salmon occurs in the ocean, the ocean plays an important role in determining salmon abundance. We found that 45 of 47 North Pacific salmon populations, comprising five species from North America and Asia, are decreasing in average body size. Total salmon production correlated well with environmental trends between 1925 and 1989, but the inverse relationship between population abundance and average size during the period 1975-1993 indicates that there is a limitation to the salmon-sustaining resources of the ocean. The increased ocean survivorship and expansion of enhancement programs in the 1980s and early 1990s are probable factors in the ocean-wide reduced size of salmon. If these trends continue, the productivity of salmon populations may decrease as fecundity, egg size, and age at maturity change in response. C1 FISHERIES & OCEANS CANADA,PACIFIC BIOL STN,NANAIMO,BC V9R 5K6,CANADA. US NATL MARINE FISHERIES SERV,AUKE BAY LAB,JUNEAU,AK 99801. RP Bigler, BS (reprint author), WARDS COVE PACKIG CO,POB C-5030,SEATTLE,WA 98105, USA. NR 35 TC 99 Z9 112 U1 0 U2 15 PU NATL RESEARCH COUNCIL CANADA PI OTTAWA PA RESEARCH JOURNALS, MONTREAL RD, OTTAWA ON K1A 0R6, CANADA SN 0706-652X J9 CAN J FISH AQUAT SCI JI Can. J. Fish. Aquat. Sci. PD FEB PY 1996 VL 53 IS 2 BP 455 EP 465 DI 10.1139/cjfas-53-2-455 PG 11 WC Fisheries; Marine & Freshwater Biology SC Fisheries; Marine & Freshwater Biology GA UK632 UT WOS:A1996UK63200024 ER PT J AU Overpeck, J Anderson, D Trumbore, S Prell, W AF Overpeck, J Anderson, D Trumbore, S Prell, W TI The southwest Indian Monsoon over the last 18000 years SO CLIMATE DYNAMICS LA English DT Review ID EURASIAN SNOW COVER; PAST 30,000 YEARS; LATE QUATERNARY; ARABIAN SEA; EASTERN SAHARA; ENVIRONMENTAL-CHANGE; LEVEL FLUCTUATIONS; TANGANYIKA BASIN; CLIMATIC CHANGES; POLLEN EVIDENCE AB Previously published results suggest that the strength of the SW Indian Monsoon can vary significantly on century- to millenium time scales, an observation that has important implications for assessments of future climate and hydrologic change over densely populated portions of Asia. We present new, well-dated, multi-proxy records of past monsoon variation from three separate Arabian Sea sediment cores that span the last glacial maximum to late-Holocene. To a large extent, these records confirm earlier published suggestions that the monsoon strengthened in a series of abrupt events over the last deglaciation. However, our data provide a somewhat refined picture of when these events took place, and suggest the primacy of two abrupt increases in monsoon intensity, one between 13 and 12.5 ka, and the other between 10 and 9.5 ka. This conclusion is supported by the comparisons between our new marine data and published paleoclimatic records throughout the African-Asian monsoon region. The comparison of data sets further supports the assertion that maximum monsoon intensity lagged peak insolation forcing by about 3000 years, and extended from about 9.5 to 5.5 ka. The episodes of rapid monsoon intensification coincided with major shifts in North Atlantic-European surface temperatures and ice-sheet extent. This coincidence, coupled with new climate model experiments, suggests that the large land-sea thermal gradient needed to drive strong monsoons developed only after glacial conditions upstream of, and on, the Tibetan Plateau receded (cold North Atlantic sea-surface temperatures, European ice-sheets, and extensive Asian snow cover). It is likely that abrupt changes in seasonal soil hydrology were as important to past monsoon forcing as were abrupt snow-related changes in regional albedo. Our analysis suggests that the monsoon responded more linearly to insolation forcing after the disappearance of glacial boundary conditions, decreasing gradually after about 6 ka. Our data also support the possibility that significant century-scale decreases in monsoon intensity took place during the early to mid-Holocene period of enhanced monsoon strength, further highlighting the need to understand paleomonsoon dynamics before accurate assessments of future monsoon strength can be made. C1 UNIV COLORADO,INST ARCTIC & ALPINE RES,BOULDER,CO 80309. UNIV CALIF IRVINE,DEPT EARTH SYST SCI,IRVINE,CA 92717. BROWN UNIV,DEPT GEOL SCI,PROVIDENCE,RI 02912. RP Overpeck, J (reprint author), NOAA,NATL GEOPHYS DATA CTR,PALEOCLIMATOL PROGRAM,325 BROADWAY,BOULDER,CO 80303, USA. RI Trumbore, Susan/B-1948-2013; anderson, david/E-6416-2011 NR 101 TC 378 Z9 408 U1 6 U2 62 PU SPRINGER VERLAG PI NEW YORK PA 175 FIFTH AVE, NEW YORK, NY 10010 SN 0930-7575 J9 CLIM DYNAM JI Clim. Dyn. PD FEB PY 1996 VL 12 IS 3 BP 213 EP 225 DI 10.1007/BF00211619 PG 13 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA TV241 UT WOS:A1996TV24100005 ER PT J AU Wozny, MJ Regli, WC AF Wozny, MJ Regli, WC TI Computer science in manufacturing SO COMMUNICATIONS OF THE ACM LA English DT Editorial Material C1 NATL INST STAND & TECHNOL,CTR MFG ENGN,MFG SYST INTEGRAT DIV,GAITHERSBURG,MD 20899. RP Wozny, MJ (reprint author), US DEPT COMMERCE,WASHINGTON,DC 20230, USA. NR 0 TC 2 Z9 2 U1 0 U2 0 PU ASSOC COMPUTING MACHINERY PI NEW YORK PA 1515 BROADWAY, NEW YORK, NY 10036 SN 0001-0782 J9 COMMUN ACM JI Commun. ACM PD FEB PY 1996 VL 39 IS 2 BP 33 EP 33 PG 1 WC Computer Science, Hardware & Architecture; Computer Science, Software Engineering; Computer Science, Theory & Methods SC Computer Science GA TT536 UT WOS:A1996TT53600016 ER PT J AU Hardwick, M Spooner, DL Rando, T Morris, KC AF Hardwick, M Spooner, DL Rando, T Morris, KC TI Sharing manufacturing information in virtual enterprises SO COMMUNICATIONS OF THE ACM LA English DT Article C1 GEN DYNAM CORP,ELECT BOAT DIV,GROTON,CT 06340. NATL INST STAND & TECHNOL,GAITHERSBURG,MD 20899. RENSSELAER POLYTECH INST,DEPT COMP SCI,TROY,NY 12180. RP Hardwick, M (reprint author), RENSSELAER POLYTECH INST,LAB IND INFORMAT INFRASTRUCT,TROY,NY 12180, USA. NR 11 TC 90 Z9 92 U1 0 U2 5 PU ASSOC COMPUTING MACHINERY PI NEW YORK PA 1515 BROADWAY, NEW YORK, NY 10036 SN 0001-0782 J9 COMMUN ACM JI Commun. ACM PD FEB PY 1996 VL 39 IS 2 BP 46 EP 54 DI 10.1145/230798.230803 PG 9 WC Computer Science, Hardware & Architecture; Computer Science, Software Engineering; Computer Science, Theory & Methods SC Computer Science GA TT536 UT WOS:A1996TT53600018 ER PT J AU Thompson, L Johnson, GC AF Thompson, L Johnson, GC TI Abyssal currents generated by diffusion and geothermal heating over rises SO DEEP-SEA RESEARCH PART I-OCEANOGRAPHIC RESEARCH PAPERS LA English DT Article ID SOUTH-PACIFIC; FLOW; BOUNDARY; CIRCULATION; DEEP; TRANSPORT; LAYERS; OCEAN; SLOPE; MODEL AB A continuously stratified (in both salinity and temperature) diffusive time-dependent one-dimensional-f-plane model over a sloping bottom is constructed. The model is used to investigate the role of mixing of density near the bottom on large-scale abyssal flow near mid-ocean rises. For realistic abyssal values, both geothermal heating from the bottom and diffusion can be important to the dynamics of flow over mid-ocean rises. When diffusion dominates, buoyancy is transported toward the bottom and the theta-S (potential temperature-salinity) relation remains nearly linear. When geothermal heating dominates, the theta-S relation hooks near the bottom and a convectively driven mixed layer forms. Both effects reduce the density and stratification near the bottom. In contrast, bottom-intensified diffusion has the same effect near the bottom but results in an increase of density and stratification some distance above the bottom. If the bottom slopes, a horizontal density gradient results, setting up a geostrophic, bottom-intensified, along-slope flow that can effect mass transport. Evidence of the importance of these processes is found in the abyssal Pacific. Just over the western flank of the East Pacific Rise, a 700-900 m thick layer of low N-2 (buoyancy frequency) is warmer, saltier, and lighter than interior water at the same depth. This layer is described with CTD data from recent hydrographic sections at nominal latitudes 15 degrees S and 10 degrees N. If the interior is motionless, this low N-2 layer transports 4 and 8 x 10(6) m(3) s(-1) equatorward above the western flank of the rise at 15 degrees S and 10 degrees N, respectively. This equatorward current, a direct result of diffusion and heating over a sloping sea-floor, has a volume transport comparable to those of the deep western boundary current at these latitudes. Published by Elsevier Science Ltd. C1 NOAA,PACIFIC MARINE ENVIRONM LAB,SEATTLE,WA 98115. RP Thompson, L (reprint author), UNIV WASHINGTON,SCH OCEANOG,WB10,SEATTLE,WA 98195, USA. RI Johnson, Gregory/I-6559-2012 OI Johnson, Gregory/0000-0002-8023-4020 NR 35 TC 21 Z9 22 U1 2 U2 6 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 FEB PY 1996 VL 43 IS 2 BP 193 EP 211 DI 10.1016/0967-0637(96)00095-7 PG 19 WC Oceanography SC Oceanography GA UQ538 UT WOS:A1996UQ53800005 ER PT J AU Murnane, RJ Cochran, JK Buesseler, KO Bacon, MP AF Murnane, RJ Cochran, JK Buesseler, KO Bacon, MP TI Least-squares estimates of thorium, particle, and nutrient cycling rate constants from the JGOFS north Atlantic bloom experiment SO DEEP-SEA RESEARCH PART I-OCEANOGRAPHIC RESEARCH PAPERS LA English DT Article ID GENERALIZED SCAVENGING MODEL; OCEAN SEDIMENT TRAPS; FLUX; ISOTOPES; PACIFIC; COAGULATION; EQUATORIAL; CARBON; EXPORT; TH-234 AB Least-squaresestimates of rate constants for the cycling of thorium, total particulate material, PON, and POC are presented at three different times during the North Atlantic Bloom Experiment. The estimates are based on previously published data collected between 24 April and 30 May 1989 and include water column profiles between 100 and 400 m and sediment trap data at 150 m and 300 m. Rate constants are based on a particle cycling model with suspended small particles and rapidly sinking large particles. Conservation equations for POC, PON, total particle mass, Th-228, and Th-234 in the large particle phase and conservation equations for POC and PON in the small particle phase are used as constraints in the least-squares problem. Rate constants are predicted for 100 and 33% trap efficiency scenarios. The 33% trapping efficiency scenario produces results that are consistent with the water column Th-234 budget. The lower trapping efficiency increases aggregation and remineralization rate constants. Rate constants increase during the course of the bloom, from 2+/-0.2 to 76+/-9 year(-1) for aggregation, 156+/-17 to 524+/-74 year(-1) for disaggregation, and 13+/-1 to 77+/-10 year(-1) for remineralization. Over the course of the bloom, increases in predicted aggregation, disaggregation, and remineralization fluxes are also resolved. Copyright (C) 1996 Elsevier Science Ltd. C1 SUNY STONY BROOK,MARINE SCI RES CTR,STONY BROOK,NY 11794. WOODS HOLE OCEANOG INST,WOODS HOLE,MA 02543. RP Murnane, RJ (reprint author), PRINCETON UNIV,ATMOSPHER OCEAN SCI PROGRAM,PRINCETON,NJ 08544, USA. NR 34 TC 36 Z9 36 U1 2 U2 6 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 FEB PY 1996 VL 43 IS 2 BP 239 EP 258 DI 10.1016/0967-0637(96)00004-0 PG 20 WC Oceanography SC Oceanography GA UQ538 UT WOS:A1996UQ53800007 ER PT J AU Race, MS Fonseca, MS AF Race, MS Fonseca, MS TI Fixing compensatory mitigation: What will it take? SO ECOLOGICAL APPLICATIONS LA English DT Article DE compensatory mitigation; habitat mitigation; habitat replacement; man-made wetlands; mitigation failures; mitigation policies; permit compliance; restoration of aquatic ecosystems; wetlands management; wetlands mitigation; wetlands restoration ID RESTORATION; POLICIES AB This study was undertaken to review the current status of permit-linked mitigation policies and practices in order to determine implications of the continued use of mitigation as a wetlands management tool within the United States. Based on reviews of both published literature and agency reports, our survey of past mitigation projects nationwide indicates that the success rate of permit-linked mitigation projects remains low overall. In addition, there is continuing difficulty in translating mitigation concepts into legal principles, regulatory standards, and permit conditions that are scientifically defensible and sound. Based on the record of past poor performance, we assert that continued piecemeal revision efforts focused on technical or scientific details are not likely to make compensatory mitigation more effective. There is need to acknowledge the extent to which non-scientific, real-world complications plague current policies and practices. To prevent continued loss of wetlands under compensatory mitigation, decisive action must be taken by placing emphasis on improving compliance, generating desired acreages, and maintaining a true baseline. Without selective changes in the status quo, current policies and poor implementation are likely to lead to further wetland losses. C1 NOAA,NATL MARINE FISHERIES SERV,BEAUFORT LAB,BEAUFORT,NC 28516. RP Race, MS (reprint author), UNIV CALIF BERKELEY,COLL NAT RESOURCES,BERKELEY,CA 94720, USA. NR 34 TC 76 Z9 81 U1 1 U2 23 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 FEB PY 1996 VL 6 IS 1 BP 94 EP 101 DI 10.2307/2269556 PG 8 WC Ecology; Environmental Sciences SC Environmental Sciences & Ecology GA TU567 UT WOS:A1996TU56700020 ER PT J AU RodriguezTrelles, F Weinberg, JR Ayala, FJ AF RodriguezTrelles, F Weinberg, JR Ayala, FJ TI Presumptive rapid speciation after a founder event in a laboratory population of Nereis: Allozyme electrophoretic evidence does not support the hypothesis SO EVOLUTION LA English DT Article DE electrophoretic variation; founder principle; genetic divergence; Nereis acuminata; polychaetes; speciation ID GENETIC DISTANCE; FLUSH SPECIATION; AVERAGE HETEROZYGOSITY; DROSOPHILA C1 US DEPT COMMERCE,NE FISHERIES SCI CTR,WOODS HOLE,MA 02543. RP RodriguezTrelles, F (reprint author), UNIV CALIF IRVINE,DEPT ECOL & EVOLUTIONARY BIOL,IRVINE,CA 92717, USA. RI Rodriguez-Trelles, Francisco/E-7666-2016 NR 39 TC 7 Z9 8 U1 0 U2 3 PU SOC STUDY EVOLUTION PI LAWRENCE PA 810 E 10TH STREET, LAWRENCE, KS 66044 SN 0014-3820 J9 EVOLUTION JI Evolution PD FEB PY 1996 VL 50 IS 1 BP 457 EP 461 DI 10.2307/2410817 PG 5 WC Ecology; Evolutionary Biology; Genetics & Heredity SC Environmental Sciences & Ecology; Evolutionary Biology; Genetics & Heredity GA TX891 UT WOS:A1996TX89100043 ER PT J AU Waste, SM AF Waste, SM TI The NMFS office of habitat conservation: Protecting the habitats of living marine resources SO FISHERIES LA English DT Article AB The National Marine Fisheries Service (NMFS), an agency of the National Oceanic and Atmospheric Administration (NOAA) within the U.S. Department of Commerce, is responsible for the conservation of living marine resources (LMRs) and the habitats on which they depend. This responsibility is exercised by NMFS's Office of Habitat Conservation (OHC), which protects and conserves riparian, estuarine, and offshore habitats necessary to sustain NOAA trust resources, including fish, protected species, and associated communities. These activities are accomplished through reviewing licensing, permitting, legislative, and administrative activities; coordinating with regional fishery management councils on fishery management plans (FMPs); conducting habitat-related research; and creating special management plans for key waters and resources. In response to recommendations of several external reviews, the OHC is reorganizing the National Habitat Program. This article reviews the importance of marine habitat, the 125-year history of NMFS, the current status of its National Habitat Program, and elements of the new NMFS strategic plan for the program. RP Waste, SM (reprint author), NMFS,OFF HABITAT CONSERVAT,1315 EAST WEST HIGHWAY,SILVER SPRING,MD 20910, USA. NR 6 TC 9 Z9 9 U1 3 U2 3 PU AMER FISHERIES SOC PI BETHESDA PA 5410 GROSVENOR LANE SUITE 110, BETHESDA, MD 20814-2199 SN 0363-2415 J9 FISHERIES JI Fisheries PD FEB PY 1996 VL 21 IS 2 BP 24 EP 29 PG 6 WC Fisheries SC Fisheries GA TU896 UT WOS:A1996TU89600006 ER PT J AU KabiriBadr, M Cabezas, H AF KabiriBadr, M Cabezas, H TI A thermodynamic model for the phase behavior of salt-polymer aqueous two-phase systems SO FLUID PHASE EQUILIBRIA LA English DT Article DE aqueous two-phase; aqueous polymer salt mixture; solution theory ID 2-PHASE SYSTEMS; ELECTROLYTE-SOLUTIONS; OSMOTIC COEFFICIENTS; 25-DEGREES-C; PRESSURE AB A statistical mechanical model for the component chemical potentials has been developed to predict the behavior of multiphase aqueous salt-polymer mixtures. The model includes the effect of polymer molecular mass on system phase behavior by means of scaling laws. The model parameters have been evaluated from binary and ternary isopiestic water activities and from solution volumetric data. Calculated phase diagrams for five different systems comprising three different polyethylene glycols and three different salts are shown. Model calculations show generally good agreement with experimental results. C1 UNIV ARIZONA,DEPT CHEM ENGN,TUCSON,AZ 85721. NIST,DIV BIOTECHNOL,GAITHERSBURG,MD 20899. NR 51 TC 27 Z9 27 U1 0 U2 6 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 FEB PY 1996 VL 115 IS 1-2 BP 39 EP 58 DI 10.1016/0378-3812(95)02831-5 PG 20 WC Thermodynamics; Chemistry, Physical; Engineering, Chemical SC Thermodynamics; Chemistry; Engineering GA UB582 UT WOS:A1996UB58200003 ER PT J AU Robertson, D Sasagawa, G Klopping, F Bilham, R AF Robertson, D Sasagawa, G Klopping, F Bilham, R TI The use of differencing to eliminate environmental effects in the intercomparison of absolute gravity meters SO GEOPHYSICAL RESEARCH LETTERS LA English DT Article AB Conventional intercomparisons between absolute gravity meters are limited in accuracy by the difficulty of removing environmental signals, including effects such as Earth tides, ocean loading, and barometric pressure loading. These error sources can be eliminated completely through the use of exactly simultaneous measurements. Differencing techniques have been developed and tested which are capable of determining both the differential meter bias and the gravity difference between two nearby piers to an accuracy that is limited only by the instrumental noise. Preliminary tests show that a comparison accuracy of 0.3 mu gal may be obtained in less than 400 drops, independent of drop interval (1 mu gal = 10 nanometer/sec(2)). C1 UNIV COLORADO,DEPT GEOL SCI,BOULDER,CO 80309. UNIV COLORADO,CIRES,BOULDER,CO 80309. RP Robertson, D (reprint author), NOAA,NATL OCEAN SERV,OFF OCEAN & EARTH SCI,GEOSCI LAB,8600 N 39TH ST,LONGMONT,CO 80503, USA. OI Bilham, Roger/0000-0002-5547-4102 NR 7 TC 2 Z9 2 U1 1 U2 2 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 SN 0094-8276 J9 GEOPHYS RES LETT JI Geophys. Res. Lett. PD FEB 1 PY 1996 VL 23 IS 3 BP 245 EP 248 DI 10.1029/96GL00014 PG 4 WC Geosciences, Multidisciplinary SC Geology GA TU593 UT WOS:A1996TU59300010 ER PT J AU Zurek, RW Manney, GL Miller, AJ Gelman, ME Nagatani, RM AF Zurek, RW Manney, GL Miller, AJ Gelman, ME Nagatani, RM TI Interannual variability of the north polar vortex in the lower stratosphere during the UARS mission SO GEOPHYSICAL RESEARCH LETTERS LA English DT Article ID WINTER; OZONE AB Northern winters since the 1991 launch of UARS are compared to earlier years (1978-1991) with respect to the potential for formation of Polar Stratospheric Clouds and for isolation of the north polar vortex. Daily NMC temperature minima at 465 K late in the 1993-94 winter and again in December 1994 were the lowest values experienced at those times of year (since 1978). Northern PV gradients were unusually strong in 1991-92 prior to late January and throughout the winter in both 1992-93 and 1994-95. Of all northern winters since 1978, 1994-95 with its early extended cold spell and persistently strong PV gradients most resembled the Antarctic winter lower stratosphere. Even so, temperatures were never as low, nor was the polar vortex as large, as during a typical southern winter. Judged by daily temperature minima and PV gradients at 465 K, meteorological conditions in the Arctic winter lower stratosphere during the UARS period were more conducive to vortex ozone loss by heterogeneous chemistry than in most previous winters since 1975-79. C1 NOAA,NATL METEOROL CTR,CLIMATE ANAL CTR,WASHINGTON,DC. RP Zurek, RW (reprint author), CALTECH,JET PROP LAB,4800 OAK GROVE DR,PASADENA,CA 91109, USA. NR 17 TC 59 Z9 60 U1 0 U2 1 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 SN 0094-8276 J9 GEOPHYS RES LETT JI Geophys. Res. Lett. PD FEB 1 PY 1996 VL 23 IS 3 BP 289 EP 292 DI 10.1029/95GL03336 PG 4 WC Geosciences, Multidisciplinary SC Geology GA TU593 UT WOS:A1996TU59300021 ER PT J AU Planet, WG Miller, AJ DeLuisi, JJ Hofmann, DJ Oltmans, SJ Wild, JD McDermid, IS McPeters, RD Connor, BJ AF Planet, WG Miller, AJ DeLuisi, JJ Hofmann, DJ Oltmans, SJ Wild, JD McDermid, IS McPeters, RD Connor, BJ TI Comparison of NOAA-11 SBUV/2 ozone vertical profiles with correlative measurements SO GEOPHYSICAL RESEARCH LETTERS LA English DT Article ID STRATOSPHERIC OZONE AB Vertical profiles of ozone have been determined from observations with the Solar Backscatter Ultraviolet (SBUV/2) instrument on the NOAA-11 operational satellite. These observations began in January 1989 and continue to early 1995. Comparisons have been made with selected sets of ozone vertical profiles derived from an ensemble of satellite and land-based measurements. These include; 1) lidar and microwave measurements performed at Table Mountain, CA. 2) Umkehr observations with a mid-northern latitude set of Dobson spectrophotometers. 3) balloon ozonesondes launched from Boulder, CO. 4) measurements with the NASA SBUV on Nimbus-7. Overall, the SBUV/2 profiles within the altitude range of 1-20mb agree with the other measurements to about +/-5% with a -3 to -5% bias, the SBUV/2 values being lower. This level of agreement is consistent with the expected performance of the SBUV/2 instrument based on an extensive characterization of the instrument both in pre-launch calibration and in-orbit performance and also with current understanding of the test optical components used in pre-flight calibration. C1 NOAA,NATL METEOROL CTR,CLIMATE ANAL CTR,CAMP SPRINGS,MD. NOAA,AIR RESOURCES LAB,BOULDER,CO 80303. NOAA,CLIMATE MONITORING & DIAGNOST LAB,BOULDER,CO 80303. RES & DATA SYST CORP,GREENBELT,MD. CALTECH,JET PROPULS LAB,PASADENA,CA. NASA,GODDARD SPACE FLIGHT CTR,GREENBELT,MD. NASA,LANGLEY RES CTR,HAMPTON,VA 23665. RP Planet, WG (reprint author), NOAA,OFF RES & APPLICAT,SATELLITE RES LAB,CAMP SPRINGS,MD, USA. RI McPeters, Richard/G-4955-2013 OI McPeters, Richard/0000-0002-8926-8462 NR 11 TC 7 Z9 7 U1 0 U2 0 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 SN 0094-8276 J9 GEOPHYS RES LETT JI Geophys. Res. Lett. PD FEB 1 PY 1996 VL 23 IS 3 BP 293 EP 296 DI 10.1029/96GL00049 PG 4 WC Geosciences, Multidisciplinary SC Geology GA TU593 UT WOS:A1996TU59300022 ER PT J AU Joel, AE OReilly, P Thompson, RA Maxemchuk, NF AF Joel, AE OReilly, P Thompson, RA Maxemchuk, NF TI Circuit switching for Broadband ISDN and beyond SO IEEE JOURNAL ON SELECTED AREAS IN COMMUNICATIONS LA English DT Editorial Material C1 GTE LABS INC,WALTHAM,MA 02254. UNIV PITTSBURGH,TELECOMMUN PROGRAM,PITTSBURGH,PA 15260. NATL INST STAND & TECHNOL,GAITHERSBURG,MD 20899. 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 0733-8716 J9 IEEE J SEL AREA COMM JI IEEE J. Sel. Areas Commun. PD FEB PY 1996 VL 14 IS 2 BP 289 EP 292 DI 10.1109/JSAC.1996.481935 PG 4 WC Engineering, Electrical & Electronic; Telecommunications SC Engineering; Telecommunications GA TU606 UT WOS:A1996TU60600001 ER PT J AU Thompson, RA AF Thompson, RA TI Operational domains for circuit- and packet-switching SO IEEE JOURNAL ON SELECTED AREAS IN COMMUNICATIONS LA English DT Article AB The performance of circuit-switched and of packet-switched networks are portrayed as surfaces in a three-dimensional evaluation space, The intersection of these surfaces defines two operational domains-one optimal for circuit-switching and one for packet-switching. This result is applied to network planning in future operational domains. C1 NATL INST STAND & TECHNOL,GAINESVILLE,FL. RP Thompson, RA (reprint author), UNIV PITTSBURGH,TELCOMMUN PROGRAM,PITTSBURGH,PA 15260, 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 0733-8716 J9 IEEE J SEL AREA COMM JI IEEE J. Sel. Areas Commun. PD FEB PY 1996 VL 14 IS 2 BP 293 EP 297 DI 10.1109/49.481936 PG 5 WC Engineering, Electrical & Electronic; Telecommunications SC Engineering; Telecommunications GA TU606 UT WOS:A1996TU60600002 ER PT J AU BakerJarvis, J Janezic, MD AF BakerJarvis, J Janezic, MD TI Analysis of a two-port flanged coaxial holder for shielding effectiveness and dielectric measurements of thin films and thin materials SO IEEE TRANSACTIONS ON ELECTROMAGNETIC COMPATIBILITY LA English DT Article DE coaxial line; dielectric constant; flanged coaxial holder; loss factor; microwave measurements; nondestructive; open-ended probe; permeability measurement; permittivity measurement; shielding effectiveness; two port AB A two-port Banged coaxial probe for measuring the dielectric and magnetic properties of thin material sheets is analyzed. Closed form solutions for the two-port scattering parameters are presented. The solution assumes an incident TEM wave together with evanescent TM(on) modes. Numerical results are obtained for both the forward and inverse problem, Computations indicate that at low frequencies the incident waves are almost totally reflected, As the frequency is increased, transmission through the sample increases, Experimental results compare closely with theory, The inverse solution yielded good permittivity determination for the cases tested, The technique should prove useful for nondestructive testing of circuit boards or substrates. RP BakerJarvis, J (reprint author), NATL INST STAND & TECHNOL,DIV ELECTROMAGNET FIELDS,BOULDER,CO 80303, USA. NR 9 TC 23 Z9 24 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 FEB PY 1996 VL 38 IS 1 BP 67 EP 70 DI 10.1109/15.485697 PG 4 WC Engineering, Electrical & Electronic; Telecommunications SC Engineering; Telecommunications GA UA154 UT WOS:A1996UA15400009 ER PT J AU Allen, RA Cresswell, MW Ellenwood, CH Linholm, LW AF Allen, RA Cresswell, MW Ellenwood, CH Linholm, LW TI The enhanced voltage-dividing potentiometer for high-precision feature placement metrology SO IEEE TRANSACTIONS ON INSTRUMENTATION AND MEASUREMENT LA English DT Article AB Enhancements to the voltage-dividing potentiometer, an electrical test structure for measuring the spatial separations of pairs of conducting features, are presented and discussed, These enhancements reduce or eliminate systematic errors which can otherwise lead to uncertainties as large as several hundred nanometers, These systematic errors, attributed by modeling to asymmetries at certain intersections of conducting features in the test structure, are eliminated by modifications to the test structure and test procedures. RP Allen, RA (reprint author), NATL INST STAND & TECHNOL,GAITHERSBURG,MD 20899, USA. NR 6 TC 7 Z9 7 U1 0 U2 0 PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017-2394 SN 0018-9456 J9 IEEE T INSTRUM MEAS JI IEEE Trans. Instrum. Meas. PD FEB PY 1996 VL 45 IS 1 BP 136 EP 141 DI 10.1109/19.481325 PG 6 WC Engineering, Electrical & Electronic; Instruments & Instrumentation SC Engineering; Instruments & Instrumentation GA TU610 UT WOS:A1996TU61000023 ER PT J AU Misakian, M Fenimore, C AF Misakian, M Fenimore, C TI Distributions of measurement error for three-axis magnetic field meters during measurements near appliances SO IEEE TRANSACTIONS ON INSTRUMENTATION AND MEASUREMENT LA English DT Article ID EXPOSURE AB Comparisons are made between the average magnetic flux density as would be measured with a three-axis coil probe and the flux density at the center of the probe. Probability distributions of the differences between the two quantities are calculated assuming a dipole magnetic field and are found to be asymmetric. The distributions allow estimates of uncertainty for resultant magnetic field measurements made near some electrical appliances and other electrical equipment. RP Misakian, M (reprint author), NATL INST STAND & TECHNOL,GAITHERSBURG,MD 20899, USA. NR 8 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 0018-9456 J9 IEEE T INSTRUM MEAS JI IEEE Trans. Instrum. Meas. PD FEB PY 1996 VL 45 IS 1 BP 244 EP 249 DI 10.1109/19.481341 PG 6 WC Engineering, Electrical & Electronic; Instruments & Instrumentation SC Engineering; Instruments & Instrumentation GA TU610 UT WOS:A1996TU61000039 ER PT J AU Weiss, MA Walls, FL AF Weiss, MA Walls, FL TI Preliminary evaluation of time scales based on hydrogen masers SO IEEE TRANSACTIONS ON INSTRUMENTATION AND MEASUREMENT LA English DT Article ID FREQUENCY; PRECISION; ACCURACY; CLOCKS AB Two experimental time scales based on ensembles of hydrogen masers were generated and compared with a variety of other references both internal and external to NIST, The masers all had some type of active cavity control to reduce frequency drift due to cavity changes. The first experimental time scale, TA2M, was generated over the interval from MJD 49050 to 49190 (March 4, 1993-July 22, 1993) using measurements between the masers every 6 hours. TA2M was compared to the NIST AT1 time scale, primarily based on commercial cesium frequency standards, and via once-per-day GPS common-view measurements to the USNO unsteered master flock and to UTC. The linear frequency drift of TA2M relative to UTC was small compared to the uncertainty of 2 . 10(-16)/d in estimating linear frequency drift. The masers at NIST were then linked to two masers at USNO using GPS common-view time transfer to study the performance of a maser ensemble, TA2M1, at measurement times from a few days to a few months, Again we found that the frequency drift of TA2M1 relative to UTC was smaller than the estimation uncertainty of 0.6 . 10(-16)/d. The stability of the ensemble at 1 month appeared to be about 1-2 parts in 10(15). From this work we see that the use of autotuned hydrogen masers in time scales is very promising, A single such maser rivals the 1993 stability of UTC, The typical fractional frequency stability of the masers showed flicker frequency modulation at 4 . 10(-15) or less for measurement times of 10 d-20 d, Linear frequency drift was measured for the masers against the TA2M1 time scale at levels under 1 . 10(-16)/d with uncertainties of 0.3 . 10(-16)/d. Measuring frequency drift against the definition of the SI second at this level pushes the limits of current technology. RP Weiss, MA (reprint author), NATL INST STAND & TECHNOL,DIV TIME & FREQUENCY,BOULDER,CO 80303, USA. NR 18 TC 1 Z9 1 U1 0 U2 0 PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017-2394 SN 0018-9456 J9 IEEE T INSTRUM MEAS JI IEEE Trans. Instrum. Meas. PD FEB PY 1996 VL 45 IS 1 BP 265 EP 270 DI 10.1109/19.481345 PG 6 WC Engineering, Electrical & Electronic; Instruments & Instrumentation SC Engineering; Instruments & Instrumentation GA TU610 UT WOS:A1996TU61000043 ER PT J AU Rozsa, K Stutsin, G Gallagher, A AF Rozsa, K Stutsin, G Gallagher, A TI Emission from a dc discharge with a partially covered cathode SO IEEE TRANSACTIONS ON PLASMA SCIENCE LA English DT Article AB A photograph showing the spatial pattern of visible emission from the sheath regions of an Ar de discharge, using a partially covered cathode, demonstrates the behavior of the energetic electrons, Their beam-like character as well as their spreading and penetration into the negative glow are clearly demonstrated, as is the cathode glow due to heavy particle excitation. C1 SILICONIX CORP,SANTA CLARA,CA 95056. UNIV COLORADO,JOINT INST LAB ASTROPHYS,BOULDER,CO 80309. NATL INST STAND & TECHNOL,BOULDER,CO 80309. RP Rozsa, K (reprint author), HUNGARIAN ACAD SCI,SOLID STATE PHYS RES INST,H-1525 BUDAPEST,HUNGARY. NR 3 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 0093-3813 J9 IEEE T PLASMA SCI JI IEEE Trans. Plasma Sci. PD FEB PY 1996 VL 24 IS 1 BP 55 EP 56 DI 10.1109/27.491688 PG 2 WC Physics, Fluids & Plasmas SC Physics GA UE718 UT WOS:A1996UE71800027 ER PT J AU Petrovic, ZL Phelps, AV AF Petrovic, ZL Phelps, AV TI Constrictions in cathode-dominated, low-pressure argon discharges SO IEEE TRANSACTIONS ON PLASMA SCIENCE LA English DT Article ID CURRENT ELECTRICAL DISCHARGES; PARALLEL-PLANE ELECTRODES; OSCILLATIONS AB The spatial development of constrictions across the cathode of a low-pressure, quasi-steady-state discharge in argon is recorded as a function of discharge current through the use of charge-coupled device (CCD) camera observations of light emission through a semitransparent anode. C1 NIST,BOULDER,CO 80308. RP Petrovic, ZL (reprint author), UNIV COLORADO,ASTROPHYS LAB,BOULDER,CO 80308, USA. OI Petrovic, Zoran/0000-0001-6569-9447 NR 4 TC 5 Z9 5 U1 1 U2 2 PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017-2394 SN 0093-3813 J9 IEEE T PLASMA SCI JI IEEE Trans. Plasma Sci. PD FEB PY 1996 VL 24 IS 1 BP 107 EP 108 DI 10.1109/27.491735 PG 2 WC Physics, Fluids & Plasmas SC Physics GA UE718 UT WOS:A1996UE71800053 ER PT J AU McMillin, BK Zachariah, MR AF McMillin, BK Zachariah, MR TI Two-dimensional images of CF2 density in CF4/Ar plasmas by laser-induced fluorescence in a GEC RF reference cell SO IEEE TRANSACTIONS ON PLASMA SCIENCE LA English DT Article AB Spatially resolved two dimensional (2-D) maps of the relative CF2 density in low-pressure CF4/Ar RF discharges, generated within a parallel-plate gaseous electronics conference (GEC) reference reactor, have been obtained using planar laser-induced fluorescence imaging (PLIF). The results illustrate the changes in CF2 density and distribution in the central plane of the discharge region as flowrate is varied over 10-100 seem at constant power and pressure, and as pressure is varied over 13.3-133.3 Pa at constant flowrate and power. C1 NIST,CHEM SCI & TECHNOL LAB,GAITHERSBURG,MD 20899. RP McMillin, BK (reprint author), LAM RES CORP,FREMONT,CA 94538, USA. NR 5 TC 6 Z9 6 U1 2 U2 2 PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017-2394 SN 0093-3813 J9 IEEE T PLASMA SCI JI IEEE Trans. Plasma Sci. PD FEB PY 1996 VL 24 IS 1 BP 113 EP 114 DI 10.1109/27.491738 PG 2 WC Physics, Fluids & Plasmas SC Physics GA UE718 UT WOS:A1996UE71800056 ER PT J AU Hayden, CM Wade, GS Schmit, TJ AF Hayden, CM Wade, GS Schmit, TJ TI Derived product imagery from GOES-8 SO JOURNAL OF APPLIED METEOROLOGY LA English DT Article ID CHANNELS; SOUNDER AB Derived product imagery (DPI) is a method of presenting quantitative meteorological information, derived from satellite measurements, as a color-coded image at single-pixel resolution. Its intended use is as animated sequences to observe trends in the displayed quantities, which for the GOES-8 are total precipitable water, lifted index, and surface skin temperature. These products are produced once per hour, over the continental United States and the Gulf of Mexico. This paper reviews the development of the DPI and details the algorithm used for GOES-8. The quality of the products is discussed, and an example is given. The greatest value of the DPI probably ties in comparing a sequence of the satellite product with a sequence derived from a numerical forecast. In this way, deviation of the forecast from reality is readily exposed. C1 UNIV WISCONSIN,COOPERAT INST METEOROL SATELLITE STUDIES,MADISON,WI. RP Hayden, CM (reprint author), NOAA,NESDIS,SDAB,1225 W DAYTON ST,2ND FLOOR,MADISON,WI 53706, USA. RI Wade, Gary S./F-5630-2010; Schmit, Timothy/F-5624-2010 NR 13 TC 33 Z9 33 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 FEB PY 1996 VL 35 IS 2 BP 153 EP 162 DI 10.1175/1520-0450(1996)035<0153:DPIF>2.0.CO;2 PG 10 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA UB909 UT WOS:A1996UB90900001 ER PT J AU Basist, A Garrett, D Ferraro, R Grody, N Mitchell, K AF Basist, A Garrett, D Ferraro, R Grody, N Mitchell, K TI A comparison between snow cover products derived from visible and microwave satellite observations SO JOURNAL OF APPLIED METEOROLOGY LA English DT Article ID NORTHERN-HEMISPHERE; PRECIPITATION AB A comparison between two satellite-derived snow cover products demonstrates the strengths and weakness of each procedure. The current NESDIS operational product is subjectively derived from visible satellite imagery. The analysis is performed once a week, using the most recent clear view of the surface. The experimental product is objectively derived from daily microwave measurements observed by polar-orbiting satellites. The operational product uses a high albedo in the visible spectrum to identify snow cover, whereas the experimental product uses a passive microwave scattering signature. Comparisons between the operational and experimental product show good agreement in the extent and distribution of snow cover during the middle of the winter and summer seasons. However, the agreement weakens in the transition seasons and along the southern edge of the snowpack. The analysis suggests that the operational procedure is better at observing snow under a densely vegetated canopy, whereas the experimental procedure is better over rugged terrain and persistent cloud cover. The experimental product is also better at observing rapid fluctuations in the snowpack, since it has higher temporal resolution and can see through nonprecipitating clouds. An integration of the two products, currently under development by NOAA/Office of Research and Application and the National Meteorological Center, would represent true snow cover better than either single procedure. However, it would probably introduce discontinuity into the 25-yr time series of the current operational product, which is the longest record of snow cover over the Northern Hemisphere. Averaging the experimental product between two consecutive weeks effectively brings the two datasets into closer agreement throughout the global time series. However, this technique does not resolve the regional biases between the two datasets. Surface observations would help identify the source of these regional biases; unfortunately, these reports are severely limited over many areas. C1 NOAA,OFF RES & APPLICAT,CAMP SPRINGS,MD. NATL METEOROL CTR,CAMP SPRINGS,MD. RP Basist, A (reprint author), CLIMATE PREDICT CTR,5200 AUTH RD,ROOM 605,CAMP SPRINGS,MD 20746, USA. RI Ferraro, Ralph/F-5587-2010 OI Ferraro, Ralph/0000-0002-8393-7135 NR 29 TC 47 Z9 50 U1 0 U2 2 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 FEB PY 1996 VL 35 IS 2 BP 163 EP 177 DI 10.1175/1520-0450(1996)035<0163:ACBSCP>2.0.CO;2 PG 15 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA UB909 UT WOS:A1996UB90900002 ER PT J AU Davis, RF AF Davis, RF TI Comparison of modeled to observed global irradiance SO JOURNAL OF APPLIED METEOROLOGY LA English DT Article ID SOLAR SPECTRAL IRRADIANCE; EARTHS SURFACE; RADIATION; PHOTOSYNTHESIS; ATMOSPHERES; LIGHT; CLEAR; OCEAN AB The accuracy of a spectral, clear-sky model to predict hourly global irradiance was investigated using radiation and meteorological observations collected at the Seattle-Tacoma airport between 1 January 1988 and 31 October 1991. The model was first run using the 1976 U.S. standard atmosphere values as inputs, then using the local atmospheric conditions. Clear-sky irradiance values generated by both atmospheres, standard and local, were attenuated using local cloud cover observations for comparison with measured irradiance. Values and trends of the statistical descriptors for the two atmospheres were almost identical. Overall, the model overestimated observed irradiance by less than 6%. Cloud cover was the major source of deviation between the modeled and observed values. The close correspondence between the two model runs suggests that the U.S. standard atmosphere, in conjunction with global cloud datasets, can be used in spectral models to generate irradiance at remote locations. C1 NOAA,NATL MARINE FISHERIES SERV,ALASKA FISHERIES SCI CTR,SEATTLE,WA 98115. NR 33 TC 4 Z9 5 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 FEB PY 1996 VL 35 IS 2 BP 192 EP 201 DI 10.1175/1520-0450(1996)035<0192:COMTOG>2.0.CO;2 PG 10 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA UB909 UT WOS:A1996UB90900004 ER PT J AU Nastrom, GD VanZandt, TE AF Nastrom, GD VanZandt, TE TI Biases due to gravity waves in wind profiler measurements of winds SO JOURNAL OF APPLIED METEOROLOGY LA English DT Article ID MOMENTUM FLUXES; RADAR; STRATOSPHERE; TROPOSPHERE; ENERGY AB Radar reflectivity for Bragg scattering is proportional to the atmospheric static stability. In vertically propagating gravity waves the perturbations to the static stability and to the winds occur either in phase or out of phase, so that the radar reflectivity and the wind perturbations are correlated. This correlation leads to a bias in winds observed by radars and any other remote sensors that rely on Bragg scattering. The magnitude of the biases of the vertical and horizontal wind components due to a monochromatic wave propagating in the radar beam are found to be proportional to the amplitude squared of the gravity wave, and for a spectrum of waves they are proportional to the spectral energy. For radar systems with two coplanar beams, the bias to the observations of horizontal wind speed is about 0.2 m s(-1) for gravity wave amplitudes typically encountered over flat terrain at midlatitudes and increases to 1 m s(-1) or more for wave amplitudes seen over mountainous terrain and in the vicinity of fronts, etc. For radars with only one oblique beam, the magnitude of the bias in the horizontal wind speed due to waves with typical amplitudes ranges from near zero to several meters per second, depending on wave amplitudes and on the zenith angle of the beam. The bias to the mean vertical velocity is a few centimeters per second for similar wave conditions. Variances of velocities along oblique beams also have a bias due to vertically propagating gravity waves; ranging from near zero to about 0.5 m(2) s(-2) depending on the zenith angle of the beam and on the ratios of the radar vertical range-gate size and temporal averaging period relative to the wave vertical wavelength and the wave period. The observed vertical momentum flux is about 20% smaller than the true momentum flux due to this bias effect. The theoretical predictions of biases due to gravity waves are compared with observations from the Flatland 50-MHz radar, located in the very flat terrain of central Illinois. It is found that the magnitude and the sign of the observed differences between eastward- and westward-directed beams are about the same size as expected for gravity waves with amplitudes typically observed at Flatland. The mean momentum flux for all cases combined is also consistent with the predictions of this theory for wave energy propagation upward toward the east, whereas the momentum flux for those cases with large variances in the midtroposphere at Flatland is about -0.15 m(2) s(-2) and is consistent with wave energy propagation downward toward the east (or upward toward the west). C1 NOAA,AERON LAB,BOULDER,CO 80303. RP Nastrom, GD (reprint author), ST CLOUD STATE UNIV,DEPT EARTH SCI,720 4TH AVE S,ST CLOUD,MN 56301, USA. NR 19 TC 19 Z9 19 U1 0 U2 2 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 FEB PY 1996 VL 35 IS 2 BP 243 EP 257 DI 10.1175/1520-0450(1996)035<0243:BDTGWI>2.0.CO;2 PG 15 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA UB909 UT WOS:A1996UB90900008 ER PT J AU Mantese, JV Micheli, AL Dungan, DF Geyer, RG BakerJarvis, J Grosvenor, J AF Mantese, JV Micheli, AL Dungan, DF Geyer, RG BakerJarvis, J Grosvenor, J TI Applicability of effective medium theory to ferroelectric/ferrimagnetic composites with composition and frequency-dependent complex permittivities and permeabilities SO JOURNAL OF APPLIED PHYSICS LA English DT Article ID GRANULAR METAL-FILMS; DIELECTRIC-CONSTANT; 2-COMPONENT COMPOSITE; RIGOROUS BOUNDS AB High-frequency (1 MHz-1 GHz) transmission line measurements were used to determine the composition and frequency-dependent complex permittivities and complex permeabilities of ferroelectric/ferrimagnetic (barium titanate and a magnesium-copper-zinc ferrite) composites. The effective medium rules of Maxwell-Garnett give both lower and upper bounds for the effective permittivities and permeabilities and yield accurate estimates of the bulk electric and magnetic properties at low volume fill fraction of either component provided the proper host matrix is chosen. Bruggeman theory yielded the best predictive values for the permittivity and permeability over the entire composition range. In all cases these complex quantities were shown to be constrained by Bergman-Milton bounds. (C) 1996 American Institute of Physics. C1 NATL INST STAND & TECHNOL,DIV ELECTROMAGNET FIELDS,BOULDER,CO 80303. RP Mantese, JV (reprint author), GM CORP,RES & DEV LABS,ELECT & ELECTR DEPT,30500 MOUND RD,WARREN,MI 48090, USA. NR 36 TC 86 Z9 91 U1 0 U2 11 PU AMER INST PHYSICS PI WOODBURY PA CIRCULATION FULFILLMENT DIV, 500 SUNNYSIDE BLVD, WOODBURY, NY 11797-2999 SN 0021-8979 J9 J APPL PHYS JI J. Appl. Phys. PD FEB 1 PY 1996 VL 79 IS 3 BP 1655 EP 1660 DI 10.1063/1.361010 PG 6 WC Physics, Applied SC Physics GA TT922 UT WOS:A1996TT92200062 ER PT J AU Nystuen, JA Proni, JR Black, PG Wilkerson, JC AF Nystuen, JA Proni, JR Black, PG Wilkerson, JC TI A comparison of automatic rain gauges SO JOURNAL OF ATMOSPHERIC AND OCEANIC TECHNOLOGY LA English DT Article ID UNDERWATER AB Automatic rain gauge systems are required to collect rainfall data at remote locations, especially oceanic sites where logistics prevent regular visits. Rainfall data from six different types of automatic rain gauge systems have been collected for a set of summertime subtropical rain events and for a set of wintertime rain events at Miami, Florida. The rain gauge systems include three types of collection gauges: weighing, capacitance, and tipping bucket; two gauges that inherently measure rainfall rate: optical scintillation and underwater acoustical inversion; and one gauge that detects individual raindrops: the disdrometer. All of these measurement techniques perform well; that is, they produce rainfall estimates that are highly correlated to one another. However, each method has limitations. The collection gauges are affected by flow irregularities between the catchment basin and the measurement chambers. This affects the accuracy of rainfall-rate measurements from these instruments, especially at low rainfall rates. In the case of the capacitance gauge, errors in 1-min rainfall rates can exceed +10 mm h(-1). The rainfall rate gauges showed more scatter than the collection gauges for rainfall rates over 5 mm h(-1), and the scatter was relatively independent of rainfall rate. Changes in drop size distribution within an event could not be used to explain the scatter observed in the optical rain gauge data. The acoustical inversion method can be used to measure the drop size distribution, allowing rainfall classification and estimation of other rain parameters-for example, reflectivity or liquid water content-in addition to rainfall rate. The acoustical inversion method has the advantage of an extremely large catchment area, resulting in very high time resolution. The disdrometer showed a large scatter relative to the other rain gauge systems for low rainfall rates. This is consistent with the small catchment area for the disdrometer system. C1 NOAA, ATLANTIC OCEANOG & METEOROL LAB, OCEAN ACOUST DIV, MIAMI, FL 33149 USA. NOAA, ATLANTIC OCEANOG & METEOROL LAB, HURRICANE RES DIV, MIAMI, FL USA. NOAA, NATL ENVIRONM SATELLITE DATA & INFORMAT SERV, SATELLITE RES LAB, CAMP SPRINGS, MD USA. NR 15 TC 34 Z9 36 U1 2 U2 12 PU AMER METEOROLOGICAL SOC PI BOSTON PA 45 BEACON ST, BOSTON, MA 02108-3693 USA SN 0739-0572 J9 J ATMOS OCEAN TECH JI J. Atmos. Ocean. Technol. PD FEB PY 1996 VL 13 IS 1 BP 62 EP 73 DI 10.1175/1520-0426(1996)013<0062:ACOARG>2.0.CO;2 PG 12 WC Engineering, Ocean; Meteorology & Atmospheric Sciences SC Engineering; Meteorology & Atmospheric Sciences GA UB899 UT WOS:A1996UB89900008 ER PT J AU Matrosov, SY Reinking, RF Kropfli, RA Bartram, BW AF Matrosov, SY Reinking, RF Kropfli, RA Bartram, BW TI Estimation of ice hydrometeor types and shapes from radar polarization measurements SO JOURNAL OF ATMOSPHERIC AND OCEANIC TECHNOLOGY LA English DT Article ID CIRRUS CLOUDS; DEPENDENCE AB An approach to distinguish between various types of ice hydrometeors and to estimate their shapes using radar polarization measurements is discussed. It is shown that elevation angle dependencies of radar depolarization ratios can be used to distinguish between planar crystals, columnar crystals, and aggregates in reasonably homogeneous stratiform clouds. Absolute values of these ratios depend on the reflectivity-weighted mean particle aspect ratio in the polarization plane. Circular depolarization ratios depend on this ratio, and linear depolarization ratios depend on this ratio and particle orientation in the polarization plane. The use of nearly circular elliptical polarization provides a means of measuring depolarization for low reflectivity scatterers when the circular polarization fails due to low signal level in one of the receiving channels. Modeling of radar backscattering was applied to the elliptical depolarization ratios as measured by the K-a-band radar developed at the NOAA Environmental Technology Laboratory. Experimental data taken during the Winter Icing and Storms Instrument Test experiment in 1993 generally confirmed the calculations and demonstrated the applicability of the approach. C1 UNIV COLORADO,COOPERAT INST RES ENVIRONM SCI,BOULDER,CO 80309. NOAA,ETL,BOULDER,CO. NR 30 TC 45 Z9 48 U1 1 U2 3 PU AMER METEOROLOGICAL SOC PI BOSTON PA 45 BEACON ST, BOSTON, MA 02108-3693 SN 0739-0572 J9 J ATMOS OCEAN TECH JI J. Atmos. Ocean. Technol. PD FEB PY 1996 VL 13 IS 1 BP 85 EP 96 DI 10.1175/1520-0426(1996)013<0085:EOIHTA>2.0.CO;2 PG 12 WC Engineering, Ocean; Meteorology & Atmospheric Sciences SC Engineering; Meteorology & Atmospheric Sciences GA UB899 UT WOS:A1996UB89900010 ER PT J AU Tatarskii, VV Tatarskaia, MS Westwater, ER AF Tatarskii, VV Tatarskaia, MS Westwater, ER TI Statistical retrieval of humidity profiles from precipitable water vapor and surface measurements of humidity and temperature SO JOURNAL OF ATMOSPHERIC AND OCEANIC TECHNOLOGY LA English DT Article ID WIND PROFILER; RASS AB A new method is presented of statistical retrieval of humidity profiles based on measurements of surface temperature xi(1), surface dewpoint xi(2), and integrated water vapor xi(3). In this method the retrieved values of humidity depend nonlinearly on predictors xi(1,2,3). A self-training algorithm was developed to obtain the values of parameters that enter into the retrieval algorithm. The data from two years of measurements in eight different locations were used for training. The method was applied to an independent dataset (including nonmonotonic profiles) of one month of surface measurements and integrated water vapor obtained from microwave radiometers. Three constraints were imposed: 1) the integrated retrieved humidity profiles had to be equal to the measured values xi(3), 2) the retrieved surface humidity had to coincide with the measured value, and 3) the retrieved humidity had to be positive. The rms deviations of restored humidity values from measured profiles were approximately two times less than natural variations. A limited comparison with conventional linear statistical inversion showed that the nonlinear method may improve the recovery of vertical structure. C1 UNIV COLORADO,COOPERAT INST RES ENVIRONM SCI,BOULDER,CO 80309. NOAA,ENVIRONM TECHNOL LAB,BOULDER,CO. NR 13 TC 3 Z9 3 U1 0 U2 0 PU AMER METEOROLOGICAL SOC PI BOSTON PA 45 BEACON ST, BOSTON, MA 02108-3693 SN 0739-0572 J9 J ATMOS OCEAN TECH JI J. Atmos. Ocean. Technol. PD FEB PY 1996 VL 13 IS 1 BP 165 EP 174 DI 10.1175/1520-0426(1996)013<0165:SROHPF>2.0.CO;2 PG 10 WC Engineering, Ocean; Meteorology & Atmospheric Sciences SC Engineering; Meteorology & Atmospheric Sciences GA UB899 UT WOS:A1996UB89900015 ER PT J AU Tewari, YB Schantz, MM Rekharsky, MV Goldberg, RN AF Tewari, YB Schantz, MM Rekharsky, MV Goldberg, RN TI Thermodynamics of the hydrolysis of 3,4,5-trihydroxybenzoic acid propyl ester (n-propylgallate) to 3,4,5-trihydroxybenzoic acid (gallic acid) and propan-1-ol in aqueous media and in toluene SO JOURNAL OF CHEMICAL THERMODYNAMICS LA English DT Article ID LIPASE-CATALYZED ESTERIFICATION; EQUILIBRIUM POSITION; SYSTEMS AB Equilibrium measurements at several temperatures between 293 K and 308 K have been performed on the tannase catalyzed reaction: 3,4,5-trihydroxybenzoic acid propyl ester(sln) + H2O(sln) = 3,4,5-trihydroxybenzoic acid(sln) + propan-1-ol(sln), where sln = aqueous phosphate buffer, aqueous acetate buffer, and toluene. The change in binding of the hydrogen ion Delta(r),N(H+) for this biochemical reaction in aqueous solution was calculated both from an equilibrium model for the biochemical reaction and from the dependence of the apparent equilibrium constant on pH Calorimetric measurements were also performed for this biochemical reaction in aqueous phosphate and 2-(N-morpholino)ethanesulfonic acid (MES) buffers. Standard transformed thermodynamic quantities for the overall biochemical reaction as well as standard thermodynamic quantities for chemical reference reactions that involve specific chemical species have been calculated from the experimental results. It was found that the equilibrium yield of 3,4,5-trihydroxybenzoic acid propyl ester is significantly enhanced by carrying out the reaction in toluene rather than in the aqueous buffered solutions. The standard molar enthalpy change Delta(r)H(m)(o) for the dissociation reaction MES(+/-)(aq) = MES(-) (ag) + H+(aq) has been measured calorimetrically and is -(15.0 +/- 0.1)kJ . mol(-1) at the temperature T = 298.15 K and ionic strength I = 0. (C) 1996 Academic Press Limited C1 NIST,DIV ANALYT CHEM,GAITHERSBURG,MD 20899. RP Tewari, YB (reprint author), NIST,DIV BIOTECHNOL,GAITHERSBURG,MD 20899, USA. NR 29 TC 8 Z9 8 U1 1 U2 5 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 FEB PY 1996 VL 28 IS 2 BP 171 EP 185 DI 10.1006/jcht.1996.0016 PG 15 WC Thermodynamics; Chemistry, Physical SC Thermodynamics; Chemistry GA UB225 UT WOS:A1996UB22500008 ER PT J AU Anderson, JL Stern, WF AF Anderson, JL Stern, WF TI Evaluating the potential predictive utility of ensemble forecasts SO JOURNAL OF CLIMATE LA English DT Article ID SEA-SURFACE TEMPERATURE; SOUTHERN OSCILLATION; INTERANNUAL VARIABILITY; PREDICTABILITY; MODELS AB A method is presented for determining when an ensemble of model forecasts has the potential to provide some useful information. An ensemble forecast of a particular scalar quantity is said to have potential predictive utility when the ensemble forecast distribution is significantly different from an appropriate climatological distribution. Here, the potential predictive utility is measured using Kuiper's statistical test for comparing two discrete distributions. More traditional measures of the potential usefulness of an ensemble forecast based on ensemble mean or variance discard possibly valuable information by making implicit assumptions about the distributions being compared. Application of the potential predictive utility to long integrations of an atmospheric general circulation model in a boundary value problem (an ensemble of Atmospheric Model Intercomparison Project integrations) reveals a number of features about the response of a GCM to observed sea surface temperatures. In particular, the ensemble of forecasts is found to have potential predictive utility over large geographic areas for a number of atmospheric fields during strong Fl Nino-Southern Oscillation anomalous events. Unfortunately, there are only limited areas of potential predictive utility for near-surface fields and precipitation outside the regions of the tropical oceans. Nevertheless, the method presented here can identify all areas where the GCM ensemble may provide useful information, whereas methods that make assumptions about the distribution of the ensemble forecast variables may not be able to do so. RP Anderson, JL (reprint author), PRINCETON UNIV,NOAA,GEOPHYS FLUID DYNAM LAB,POB 308,PRINCETON,NJ 08542, USA. NR 32 TC 47 Z9 50 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 FEB PY 1996 VL 9 IS 2 BP 260 EP 269 DI 10.1175/1520-0442(1996)009<0260:ETPPUO>2.0.CO;2 PG 10 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA UB900 UT WOS:A1996UB90000002 ER PT J AU Frey, RA Ackerman, SA Soden, BJ AF Frey, RA Ackerman, SA Soden, BJ TI Climate parameters from satellite spectral measurements .1. Collocated AVHRR and HIRS/2 observations of spectral greenhouse parameter SO JOURNAL OF CLIMATE LA English DT Article ID RADIATION BUDGET; CLOUD; OCEANS; TEMPERATURES; HUMIDITY; WATER; ISCCP AB An automated method of monitoring various climate parameters using collocated Advanced Very High Resolution Radiometer (AVHRR) and High-Resolution Infrared Sounder-2 (HIRS/2) observations has been developed. The method, referred to as CHAPS (collocated HIRS/2 and AVHRR products) was implemented during the months of July 1993 and January and July 1994. This paper presents the oceanic cloud screening method and analysis of the spectral greenhouse parameter (g(lambda)) for July 1993 and January 1994. In addition, the CHAPS derived clear-sky parameters are compared to the NESDIS historical dataset. There is agreement between NESDIS and CHAPS for the g(6.7) and g(7.3). The NESDIS 8.2-mu m data appears to be cloud contaminated. Through comparison with CHAPS, it is suggested that the mode, rather than the mean, provides the better estimate of the central tendency of the NESDIS clear-sky 8.2-mu m radiance distribution, particularly for regions with extensive low-level cloud cover. It is shown that the spectral greenhouse parameter at wavelengths sensitive to middle and upper atmospheric water vapor content is dependent on SST via its connection to large-scale atmospheric circulation patterns. It is also shown that the variability of the spectral greenhouse parameter is strongly a function of latitude at these wavelengths, as well as in spectral regions sensitive to lower-level water vapor. Standard deviations are largest in the Tropics and generally decrease poleward. In contrast, variability in the spectral regions sensitive to upper-tropospheric temperature peaks in the middle latitudes and has its minimum in tropical latitudes. Variability in the relationship between g(lambda) and SST shows only a weak dependence on season for channels sensitive to water vapor content. A strong seasonal dependence is found in the g(14.2) for the middle-latitude regions associated with changes in the temperature structure of the upper troposphere. The relationship between the spectral greenhouse parameter and the broadband greenhouse parameter is presented and discussed. It is found that the range in broadband g for warm tropical SSTs is driven by spectral changes at wavelengths sensitive to upper-tropospheric water vapor. For cooler SSTs associated with the middle latitudes, the range in g is a function of the spectral greenhouse parameter sensitive to the temperature structure of the upper troposphere. C1 PRINCETON UNIV,ATMOSPHER & OCEAN SCI PROGRAM,PRINCETON,NJ 08544. RP Frey, RA (reprint author), UNIV WISCONSIN,COOPERAT INST METEOROL SATELLITE STUDIES,1225 W DAYTON ST,MADISON,WI 53706, USA. RI Ackerman, Steven/G-1640-2011 OI Ackerman, Steven/0000-0002-4476-0269 NR 34 TC 12 Z9 12 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 FEB PY 1996 VL 9 IS 2 BP 327 EP 344 DI 10.1175/1520-0442(1996)009<0327:CPFSSM>2.0.CO;2 PG 18 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA UB900 UT WOS:A1996UB90000005 ER PT J AU Manabe, S Stouffer, RJ AF Manabe, S Stouffer, RJ TI Low-frequency variability of surface air temperature in a 1000-year integration of a coupled atmosphere-ocean-land surface model SO JOURNAL OF CLIMATE LA English DT Article ID STOCHASTIC CLIMATE MODELS; TRANSIENT RESPONSES; GRADUAL CHANGES; GLOBAL CLIMATE; CO2; SENSITIVITY; SIMULATION; RESOLUTION; INCREASE; ENSO AB This study analyzes the variability of surface air temperature (SAT) and sea surface temperature (SST) obtained from a 1000-yr integration of a coupled atmosphere-ocean-land surface model, which consists of general circulation models of the atmosphere and oceans and a heat and water budget model of land surface. It also explores the role of oceans in maintaining the variability of SAT by comparing the long-term integration of the coupled model with those of two simpler models. They are 1) a ''mixed layer model,'' that is, the general circulation model of the atmosphere combined with a simple slab model of the mixed layer ocean, and 2) a ''fixed SST model,'' that is, the same atmosphere model overlying seasonally varying, prescribed SST. With the exception of the tropical Pacific, both the coupled and mixed layer models are capable of approximately simulating the standard deviations of observed annual and 5-yr-mean anomalies of local SAT. The standard deviation tends to be larger over continents than over oceans, in agreement with the observations. Over most continental regions, the standard deviations of annual, 5-yr- and 25-yr-mean SATs in the fixed SST model are slightly less than but comparable to the corresponding standard deviations in the coupled model, suggesting that a major fraction of low-frequency local SAT variability over continents of the coupled model is generated in situ. Over the continents of both the coupled and the mixed layer models, the spectral density of local SAT is nearly independent of frequency. On the other hand, the spectral density of local SAT over most of the oceans of both models increases very gradually with decreasing frequency apparently influenced by the thermal inertia of mixed layer oceans. However, both SST and SAT spectra in the coupled model are substantially different from those in the mixed layer model near the Denmark Strait and in some regions in the circumpolar ocean of the Southern Hemisphere where water mixes very deeply. In these regions, both SST and SAT are much more persistent in the coupled than in the mixed layer models, and their spectral densities are much larger at multi-decadal and/or centennial timescales. It appears significant that not only the coupled model but also the mixed layer model without ocean currents can approximately simulate the power spectrum of observed, global mean SAT at decadal to interdecadal time-scales. However, neither model generates a sustained, long-term warming trend of significant magnitude such as that observed since the end of the last century. RP Manabe, S (reprint author), PRINCETON UNIV,NOAA,GEOPHYS FLUID DYNAM LAB,POB 308,PRINCETON,NJ 08542, USA. NR 43 TC 186 Z9 192 U1 2 U2 9 PU AMER METEOROLOGICAL SOC PI BOSTON PA 45 BEACON ST, BOSTON, MA 02108-3693 SN 0894-8755 J9 J CLIMATE JI J. Clim. PD FEB PY 1996 VL 9 IS 2 BP 376 EP 393 DI 10.1175/1520-0442(1996)009<0376:LFVOSA>2.0.CO;2 PG 18 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA UB900 UT WOS:A1996UB90000008 ER PT J AU Bates, JJ Wu, X Jackson, DL AF Bates, JJ Wu, X Jackson, DL TI Interannual variability of upper-troposphere water vapor band brightness temperature SO JOURNAL OF CLIMATE LA English DT Article ID CLIMATOLOGY; ANOMALIES; HUMIDITY AB A method for the intercalibration of the high-resolution infrared sounder (HIRS) upper-tropospheric water vapor band brightness temperature data is developed and applied to data from 1981 to 1993. Analysis of the adjusted anomaly time series show the location and strength of both the large-scale ascending and descending circulations in the Tropics as well as water vapor anomalies. Comparison of these HIRS data with outgoing longwave radiation and sea surface temperature anomalies reveals that both convection and increased upper-tropospheric moisture occur over anomalously warm water in the deep Tropics. The development and movement of deep convection and increased upper-tropospheric moisture can clearly be traded during the El Nino/Southern Oscillation warm events. These HIRS data are particularly useful in monitoring upper-tropospheric water vapor variability between the Tropics and subtropics. C1 UNIV WISCONSIN,SPACE SCI & ENGN CTR,MADISON,WI. UNIV COLORADO,COOPERAT INST RES ENVIRONM SCI,BOULDER,CO 80309. RP Bates, JJ (reprint author), NOAA,ERL,RECD,CLIMATE DIAGNOST CTR,325 BROADWAY,BOULDER,CO 80303, USA. RI Bates, John/D-1012-2009; Jackson, Darren/D-5506-2015 OI Bates, John/0000-0002-8124-0406; Jackson, Darren/0000-0001-5211-7866 NR 21 TC 82 Z9 86 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 FEB PY 1996 VL 9 IS 2 BP 427 EP 438 DI 10.1175/1520-0442(1996)009<0427:IVOUTW>2.0.CO;2 PG 12 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA UB900 UT WOS:A1996UB90000011 ER PT J AU Erickson, A Sadwick, L Neubauer, G Kopanski, J Adderton, D Rogers, M AF Erickson, A Sadwick, L Neubauer, G Kopanski, J Adderton, D Rogers, M TI Quantitative scanning capacitance microscopy analysis of two-dimensional dopant concentrations at nanoscale dimensions SO JOURNAL OF ELECTRONIC MATERIALS LA English DT Article DE atomic force microscopy; capacitance-voltage theory; scanning capacitance microscopy; two-dimensional dopant profiles AB We have applied the scanning capacitance microscopy (SCM) technique of two-dimensional (2-D) semiconductor dopant profiling to implanted silicon cross sections. This has permitted the first direct comparison of SCM profiling scans to secondary ion mass spectroscopy (SIMS) depth profiles. The results compare favorably in depth and several readily identifiable features of the SIMS profiles such as peak concentration and junction depth are apparent in the SCM scans at corresponding depths. The application of dopant profiling to two dimensions is possible by calibrating the SCM levels with the one-dimensional (1-D) SIMS data. Furthermore, we have subsequently simulated the SCM results with an analytic expression readily derivable from 1-D capacitance vs voltage capacitance-voltage theory. This result represents a significant breakthrough in the quantitative measurement of 2-D doping profiles. C1 INTEL CORP,DEPT MAT TECHNOL,SANTA CLARA,CA 95052. NATL INST STAND & TECHNOL,SEMICOND RES GRP,GAITHERSBURG,MD 20899. DIGITAL INSTRUMENTS INC,SANTA BARBARA,CA 93103. RP Erickson, A (reprint author), UNIV UTAH,DEPT ELECT ENGN,SALT LAKE CITY,UT 84102, USA. NR 9 TC 33 Z9 33 U1 1 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 FEB PY 1996 VL 25 IS 2 BP 301 EP 304 DI 10.1007/BF02666260 PG 4 WC Engineering, Electrical & Electronic; Materials Science, Multidisciplinary; Physics, Applied SC Engineering; Materials Science; Physics GA TU672 UT WOS:A1996TU67200022 ER PT J AU Kelley, MC Kotsikopoulos, D Beach, T Hysell, D Musman, S AF Kelley, MC Kotsikopoulos, D Beach, T Hysell, D Musman, S TI Simultaneous global positioning system and radar observations of equatorial spread F at Kwajalein SO JOURNAL OF GEOPHYSICAL RESEARCH-SPACE PHYSICS LA English DT Article ID MIDLATITUDE IONOSPHERE; GRAVITY-WAVES; BUBBLES; FIELD; SCINTILLATIONS AB GPS satellites broadcast at two frequencies (L1 of 1575.42 MHz and L2 of 1227.6 MHz). The dispersive property of the ionosphere is frequently used to correct positional measurements for ionospheric effects. Independent measurements at the two frequencies can also be combined to form a relative ionospheric delay and a measure of the total electron content (TEC) which is uncertain by an additive constant. In a previous paper (Musman et al., 1990) estimates of this offset were utilized in constructing models of the time history of the equivalent zenith delay at Westford, Massachusetts. An ionospheric model composed of uniform shells whose electron density changes slowly in a typical diurnal pattern would produce relative ionospheric delays with a simple u-shaped or j-shaped curve. Most of the change in delay would be a result of changes in geometry between the observer and the satellite. Departures from a simple pattern are indicative of ionospheric disturbances and the influence of the protonosphere. From GPS data alone, it is ambiguous whether these disturbances are due to spatial structures, temporal changes, or some combination of the two. Equatorial spread F (ESF) refers to a variety of equatorial ionospheric disturbances, some of which are associated with rising plasma plumes having low electron density and a high degree of turbulence. This phenomenon occurs primarily between local sunset and local midnight at sites within about 15 degrees of the magnetic equator. In some seasons, disturbances can occur during two out of three evenings, while at other times it can be much quieter. GPS observations at Kwajalein (9 degrees N latitude) reported here for August 14, 1990, show severe ionospheric disruption. Two independent and simultaneous sets of radar observations confirm the presence of ESF and reveal quite a bit about the spatial and temporal conditions which affect the system. GPS observations on August 15, 1990, when no ESF was present are much quieter. We find that tens of minute variations in the TEC correspond to the motion of large scale features across the GPS field of view. More severe GPS effects are seen to be collocated with turbulent low density plumes which rise rapidly to high altitudes and drift west to east across the GPS line of sight. Severe disruption can occur in moderately sophisticated GPS systems during such events, at least near solar maximum. C1 NOAA,GEOSCI LAB,SILVER SPRING,MD 20910. RP Kelley, MC (reprint author), CORNELL UNIV,SCH ELECT ENGN,PHILLIPS HALL,ITHACA,NY 14853, USA. NR 29 TC 46 Z9 46 U1 1 U2 3 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 SN 0148-0227 J9 J GEOPHYS RES JI J. Geophys. Res-Space Phys. PD FEB 1 PY 1996 VL 101 IS A2 BP 2333 EP 2341 DI 10.1029/95JA02025 PG 9 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA TT923 UT WOS:A1996TT92300006 ER PT J AU FullerRowell, TJ Codrescu, MV Rishbeth, H Moffett, RJ Quegan, S AF FullerRowell, TJ Codrescu, MV Rishbeth, H Moffett, RJ Quegan, S TI On the seasonal response of the thermosphere and ionosphere to geomagnetic storms SO JOURNAL OF GEOPHYSICAL RESEARCH-SPACE PHYSICS LA English DT Article ID ANTARCTIC F-REGION; MAGNETIC STORM; MODEL; PATTERNS; GAS AB Ionosonde observations have provided the data to build a picture of the response of the midlatitude ionosphere to a geomagnetic storm. The particular characteristic of interest is the preference for ''negative storms'' (decrease in the peak electron density, Nmn) in summer and ''positive storms'' (increase in NmF2) in winter. A three-dimensional, time-dependent model of the coupled thermosphere and ionosphere is used to explain this dependence. During the driven phase of a geomagnetic storm the two main magnetospheric energy sources to the upper atmosphere (auroral precipitation and convective electric field) increase dramatically. Auroral precipitation increases the ion density and conductivity of the upper atmosphere; the electric field drives the ionosphere and, through collisions, forces the thermosphere into motion and then deposits heat via Joule dissipation. The global wind response is divergent at high latitudes in both hemispheres. Vertical winds are driven by the divergent wind field and carry molecule-rich air to higher levels. Once created, the ''composition bulge'' of increased mean molecular mass is transported by both the storm-induced and background wind fields. The storm winds imposed on the background circulation do not have a strong seasonal dependence, and this is not necessary to explain the observations. Numerical computations suggest that the prevailing summer-to-winter circulation at solstice transports the molecule-rich gas to mid and low latitudes in the summer hemisphere over the day or two following the storm. In the winter hemisphere, poleward winds restrict the equatorward movement of composition. The altered neutral-chemical environment in summer subsequently depletes the F region midlatitude ionosphere to produce a ''negative storm''. In winter midlatitudes a decrease in molecular species, associated with downwelling, persists and produces the characteristic ''positive storm''. C1 UNIV SHEFFIELD, SCH MATH & STAT, SHEFFIELD S3 7RH, S YORKSHIRE, ENGLAND. UNIV SOUTHAMPTON, DEPT PHYS, SOUTHAMPTON SO17 1BJ, HANTS, ENGLAND. RP FullerRowell, TJ (reprint author), UNIV COLORADO, NOAA, COOPERAT INST RES ENVIRONM SCI, SPACE ENVIRONM LAB, 325 BROADWAY, BOULDER, CO 80303 USA. NR 18 TC 257 Z9 261 U1 1 U2 13 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 2169-9380 EI 2169-9402 J9 J GEOPHYS RES-SPACE JI J. Geophys. Res-Space Phys. PD FEB 1 PY 1996 VL 101 IS A2 BP 2343 EP 2353 DI 10.1029/95JA01614 PG 11 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA TT923 UT WOS:A1996TT92300007 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 Simulation of magnetic cloud propagation in the inner heliosphere in two dimensions .2. A loop parallel to the ecliptic plane and the role of helicity SO JOURNAL OF GEOPHYSICAL RESEARCH-SPACE PHYSICS LA English DT Article AB This paper continues studies of the cylindrical magnetic clouds' propagation in the interplanetary medium. In our first paper devoted to this topic (Vandas et al., 1995) we dealt with the cloud with the axis perpendicular to the ecliptic plane and derived time dependencies of its velocity, field magnitude, and temperature as well as its shape for different initial conditions, Here, analogously, we present simulations for the cloud with the axis parallel to the ecliptic plane and show that the propagation of these clouds practically does not depend on the inclination of their axes to the ecliptic plane, We made a new conclusion concerning the helicity of the magnetic field inside the cloud. Because of the magnetic interaction with the background field, the cloud is shifted to the side where it meets with the external interplanetary magnetic field (IMF) polarity that is opposite to that within the cloud, The net effect of the time dependent Lorentz, inertial, and pressure gradient forces probably causes the complementary deformation of the whole cloud. C1 NOAA,SPACE ENVIRONM LAB,BOULDER,CO 80303. UNIV COLORADO,COOPERAT INST RES ENVIRONM SCI,BOULDER,CO 80309. RP Vandas, M (reprint author), ACAD SCI CZECH REPUBL,ASTRON INST,BOCNI 2 1401,CR-14131 PRAGUE 4,CZECH REPUBLIC. RI Vandas, Marek/G-9054-2014; xue, yansheng/A-9712-2012 NR 10 TC 34 Z9 34 U1 0 U2 0 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 SN 0148-0227 J9 J GEOPHYS RES JI J. Geophys. Res-Space Phys. PD FEB 1 PY 1996 VL 101 IS A2 BP 2505 EP 2510 DI 10.1029/95JA02446 PG 6 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA TT923 UT WOS:A1996TT92300021 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 1 Z9 1 U1 0 U2 0 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 SN 0148-0227 J9 J GEOPHYS RES JI J. Geophys. Res-Space Phys. PD FEB 1 PY 1996 VL 101 IS A2 BP 2741 EP 2744 DI 10.1029/95JA03866 PG 4 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA TT923 UT WOS:A1996TT92300045 ER PT J AU Kumar, A Jindal, R Gallawa, RL AF Kumar, A Jindal, R Gallawa, RL TI Bending induced phase shifts in arbitrarily bent rectangular-core dual-mode waveguides SO JOURNAL OF LIGHTWAVE TECHNOLOGY LA English DT Article ID ACOUSTOOPTIC FREQUENCY SHIFTER; WAVE-GUIDES; 2-MODE FIBER AB We examine the variation of the effective indexes of the two modes of an arbitrarily bent dual-mode rectangular-core waveguide, We find that under the large bending radius approximation, which is indeed the practical case for most of the devices, the waveguide bent with bending radius rho in a plane at an angle theta with the major axis is almost equivalent to bending it simultaneously in the plane of major and minor axes with bending radii rho sec theta and rho cosec theta, respectively, The bending-induced phase difference between the two modes is found (a) to be maximum when the waveguide is bent along the major axis, and (b) to decrease first and then increase in the opposite direction as the V-number is decreased, The results of our study can be used to improve the sensitivity of the dual-mode optical waveguide sensors and devices based on the bending of fiber. C1 NATL INST STAND & TECHNOL, DIV OPTOELECTR, BOULDER, CO 80303 USA. RP INDIAN INST TECHNOL, DEPT PHYS, NEW DELHI 110016, INDIA. NR 16 TC 2 Z9 2 U1 1 U2 1 PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC PI PISCATAWAY PA 445 HOES LANE, PISCATAWAY, NJ 08855-4141 USA SN 0733-8724 EI 1558-2213 J9 J LIGHTWAVE TECHNOL JI J. Lightwave Technol. PD FEB PY 1996 VL 14 IS 2 BP 196 EP 201 DI 10.1109/50.482263 PG 6 WC Engineering, Electrical & Electronic; Optics; Telecommunications SC Engineering; Optics; Telecommunications GA TU198 UT WOS:A1996TU19800011 ER PT J AU Bickham, JW Patton, JC Loughlin, TR AF Bickham, JW Patton, JC Loughlin, TR TI High variability for control-region sequences in a marine mammal: Implications for conservation and biogeography of Steller sea lions (Eumetopias jubatus) SO JOURNAL OF MAMMALOGY LA English DT Article DE marine mammals; Steller sea lions; Eumetopias jubatus; mitochondrial DNA; phylogeography ID MITOCHONDRIAL-DNA VARIATION; POLYMERASE CHAIN-REACTION; LIMITED MHC POLYMORPHISM; SOUTHERN ELEPHANT SEAL; POPULATION-GENETICS; SYSTEMATICS; EVOLUTION; ABUNDANCE; NUMBER AB The Steller sea lion (Eumetopias jubatus) is a threatened species that has experienced significant population declines over the past 3 decades. Previous genetic studies indicated low allozymic variability in this monotypic species. However, high levels of variation exist in the mitochondrial control-region, as revealed by a 238 base-pair sequence from 224 specimens taken over most of the range of the species. Patterns of macrogeographic variation indicate the presence of two genetically differentiated populations of Steller sea lions. A western population included rookeries from the Commander Islands in Russia and the Aleutian Islands and Gulf of Alaska in Alaska. An eastern population included rookeries from southeastern Alaska and Oregon. Phenetic analysis of the mitochondrial-DNA (mtDNA) haplotypes indicates that certain haplotype lineages are specific to one or the other populations. Thus, these populations have been separated for a sufficient amount of time to allow diversification of lineages. However, the two populations are paraphyletic with respect to mtDNA, which indicates that they do not trace their ancestries back to a single maternal ancestor in either case. The populations likely diverged as a result of separation in different glacial refugia. C1 LGL ECOL GENET INC, BRYAN, TX 77801 USA. NOAA, NATL MARINE FISHERIES SERV, NATL MARINE MAMMAL LAB, SEATTLE, WA 98115 USA. RP TEXAS A&M UNIV, DEPT WILDLIFE & FISHERIES SCI, COLLEGE STN, TX 77843 USA. NR 38 TC 112 Z9 118 U1 1 U2 24 PU OXFORD UNIV PRESS INC PI CARY PA JOURNALS DEPT, 2001 EVANS RD, CARY, NC 27513 USA SN 0022-2372 EI 1545-1542 J9 J MAMMAL JI J. Mammal. PD FEB PY 1996 VL 77 IS 1 BP 95 EP 108 DI 10.2307/1382712 PG 14 WC Zoology SC Zoology GA TW086 UT WOS:A1996TW08600009 ER PT J AU Berger, JR Tewary, VK AF Berger, JR Tewary, VK TI Elastic Green's function for a damaged interface in anisotropic materials SO JOURNAL OF MATERIALS RESEARCH LA English DT Article ID THIN-FILMS; COMPOSITE; DECOHESION; STRENGTH; CRACKING AB We present the derivation of the elastic Green's function for an anisotropic bimaterial in a state of plane strain, A Fourier transform method is used to calculate the Green's function. A discontinuity in displacement is permitted across the interface between the two solids. This provides a useful functional form for parameterizing damage along an interface. We show several examples for the form of the displacement discontinuity and calculate the displacement Green's function for each. The Green's function derived here is applicable to a variety of interface problems between two different anisotropic solids or for two similar solids at different orientations. C1 NATL INST STAND & TECHNOL,DIV MAT RELIABIL,BOULDER,CO 80303. RP Berger, JR (reprint author), COLORADO SCH MINES,DIV ENGN,GOLDEN,CO 80401, USA. RI Berger, John/F-5169-2010 NR 21 TC 2 Z9 2 U1 0 U2 3 PU MATERIALS RESEARCH SOCIETY PI PITTSBURGH PA 9800 MC KNIGHT ROAD SUITE 327, PITTSBURGH, PA 15237 SN 0884-2914 J9 J MATER RES JI J. Mater. Res. PD FEB PY 1996 VL 11 IS 2 BP 537 EP 544 PG 8 WC Materials Science, Multidisciplinary SC Materials Science GA TU516 UT WOS:A1996TU51600034 ER PT J AU Takasaki, N Park, L Kaeriyama, M Gharrett, AJ Okada, N AF Takasaki, N Park, L Kaeriyama, M Gharrett, AJ Okada, N TI Characterization of species-specifically amplified SINEs in three salmonid species - Chum salmon, pink salmon, and kokanee: The local environment of the genome may be important for the generation of a dominant source gene at a newly retroposed locus SO JOURNAL OF MOLECULAR EVOLUTION LA English DT Article DE salmon; SINE; retroposition ID RNA-DERIVED RETROPOSONS; ALU FAMILY MEMBERS; SUBFAMILY RELATIONSHIPS; REPETITIVE ELEMENTS; REPEATED SEQUENCES; SUCCESSIVE WAVES; LINEAGE HISTORY; DNA-SEQUENCE; EVOLUTION; AMPLIFICATION AB Short interspersed repetitive elements (SINEs), known as the HpaI family, are present in the genomes of all salmonid species (Kido et al., Proc. Natl. Acad. Sci. USA 1991, 88: 2326-2330). Recently, we showed that the retropositional efficiency of the SINE family in the lineage of chum salmon is extraordinarily high in comparison with that in other salmonid lineages (Takasaki et al., Proc. Natl. Acad. Sci. USA 1994, 91: 10153-10157). To investigate the reason for this high efficiency, we searched for members of the HpaI SINE family that have been amplified species-specifically in pink salmon. Since the efficiency of the species-specific amplification in pink salmon is not high and since other members of the same subfamily of SINEs were also amplified species-specifically in pink salmon, the actual sequence of this subfamily might not be the cause of the high retropositional efficiency of SINEs in chum salmon. Rather, it appears that a highly dominant source gene for the subfamily may have been newly created by retroposition, and some aspect of the local environment around the site of retroposition may have been responsible for the creation of this dominant source gene in chum salmon. Furthermore, a total of 11 sequences of HpaI SINEs that have been amplified species-specifically in three salmon lineages was compiled and characterized. Judging from the distribution of members of the same-sequence subfamily of SINEs in different lineages and from the distribution of the different-sequence subfamilies in the same lineage, we have concluded that multiple dispersed loci are responsible for the amplification of SINEs. We also discuss the additional possibility of horizontal transmission of SINEs between species. The availability of the sets of primers used for the detection of the species-specific amplifications of the SINEs provides a convenient and reliable method for identification of these salmonid species. C1 TOKYO INST TECHNOL,FAC BIOSCI & BIOTECHNOL,MIDORI KU,YOKOHAMA,KANAGAWA 226,JAPAN. NW FISHERIES SCI CTR,COASTAL ZONE & ESTUARINE STUDIES DIV,SEATTLE,WA 98112. FISHERIES AGCY JAPAN,HOKKAIDO SALMON HATCHERY,TOYOHIRA KU,SAPPORO,HOKKAIDO 062,JAPAN. UNIV ALASKA,SCH FISHERIES & OCEAN SCI,JUNEAU CTR,JUNEAU,AK 99801. RI Kaeriyama, Masahide/A-8500-2012 NR 66 TC 29 Z9 29 U1 0 U2 1 PU SPRINGER VERLAG PI NEW YORK PA 175 FIFTH AVE, NEW YORK, NY 10010 SN 0022-2844 J9 J MOL EVOL JI J. Mol. Evol. PD FEB PY 1996 VL 42 IS 2 BP 103 EP 116 DI 10.1007/BF02198835 PG 14 WC Biochemistry & Molecular Biology; Evolutionary Biology; Genetics & Heredity SC Biochemistry & Molecular Biology; Evolutionary Biology; Genetics & Heredity GA UC698 UT WOS:A1996UC69800006 PM 8919862 ER PT J AU Marrone, TJ Gilson, MK McCammon, JA AF Marrone, TJ Gilson, MK McCammon, JA TI Comparison of continuum and explicit models of solvation: Potentials of mean force for alanine dipeptide SO JOURNAL OF PHYSICAL CHEMISTRY LA English DT Letter ID MOLECULAR-DYNAMICS; PROGRAM AB We compute the potential of mean force (PMF) around the phi and psi torsions of alanine dipeptide with a Poisson-Boltzmann (PB) method and compare these results to simulations in explicit water. The PB method, which includes an apolar solvation term, qualitatively reproduces the PMF profiles generated in the explicit solvent simulation at a markedly lower computational cost. These results motivate more extensive testing of continuum methods for the study of conformational and binding equilibria in solution. C1 UNIV CALIF SAN DIEGO,DEPT PHARMACOL,LA JOLLA,CA 92093. NIST,CTR ADV RES BIOTECHNOL,ROCKVILLE,MD 20850. RP Marrone, TJ (reprint author), UNIV CALIF SAN DIEGO,DEPT CHEM & BIOCHEM,LA JOLLA,CA 92093, USA. NR 16 TC 74 Z9 75 U1 0 U2 2 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 SN 0022-3654 J9 J PHYS CHEM-US JI J. Phys. Chem. PD FEB 1 PY 1996 VL 100 IS 5 BP 1439 EP 1441 DI 10.1021/jp952835f PG 3 WC Chemistry, Physical SC Chemistry GA TT533 UT WOS:A1996TT53300002 ER PT J AU Oey, LY AF Oey, LY TI Simulation of mesoscale variability in the Gulf of Mexico: Sensitivity studies, comparison with observations, and trapped wave propagation SO JOURNAL OF PHYSICAL OCEANOGRAPHY LA English DT Article ID LOOP CURRENT EDDY; CONTINENTAL-SHELF; WESTERN GULF; SEA-LEVEL; CIRCULATION; MODEL; RING; TOPOGRAPHY; SATELLITE AB A primitive equation Gulf of Mexico model was used to examine variability of the Loop Current (LC) and Loop Current eddies (LCE). Realistic results were obtained for a certain range of values of the horizontal mixing coefficient: eddy paths were west and southwestward; eddy propagation speeds from 3 to 5 km day(-1); the ratio of minor to major eddy axes about 0.8; eddy shedding periods from 200 to 500 days; eddy lifetimes from 100 to 200 days; eddy sizes from 200 to 400 km; and eddy swirl transports, as fractions of the specified inflow of 30 Sv, were from 0.55 to 0.85. On the other hand the maximum vertical deepening of the 20 degrees C isotherm was 15% to 50% less than that observed, resulting in weaker near-surface currents of about 0.65 m s(-1), in comparison to observed values of 0.88 to 1.7 m s(-1). A strong correlation between eddy shedding and decreasing or reversing lower-layer (below 750 m) transport in the Yucatan Channel is found. In the western Gulf, current variability is produced by eddy arrivals, as well as by forcing due to bottom-intensified topographic Rossby waves, which propagate along the slope from the east with a group velocity of about 12 km day(-1) and periods of about 30-100 days. These waves are generally preceded by faster coastally trapped wave propagation, and all are produced by LC pulsation, eddy shedding, and westward propagation. RP Oey, LY (reprint author), PRINCETON UNIV,PROGRAM ATMOSPHER & OCEAN SCI,SAYRE HALL,FORRESTAL CAMPUS,PRINCETON,NJ 08544, USA. NR 27 TC 68 Z9 68 U1 0 U2 5 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 FEB PY 1996 VL 26 IS 2 BP 145 EP 175 DI 10.1175/1520-0485(1996)026<0145:SOMVIT>2.0.CO;2 PG 31 WC Oceanography SC Oceanography GA UB907 UT WOS:A1996UB90700001 ER PT J AU Figueroa, HA AF Figueroa, HA TI World ocean density ratios SO JOURNAL OF PHYSICAL OCEANOGRAPHY LA English DT Article ID CENTRAL WATER; SALT AB In this report, the potential for salt finger instability in the central water of the World Ocean is examined. The form of the temperature-salinity relationship determined from the Levitus climatological data and the density ratio of this relationship are used as a proxy to identify the regions that are susceptible to salt finger activity. The analysis indicates that most of the North and South Atlantic basins, and southeastern Indian and southwestern South Pacific Central Waters have density ratios smaller than 2.0. This is an indication that enhanced vertical salinity fluxes due to salt fingers can be an additional process affecting the thermocline freshwater budget. This study also indicates that most of the ocean's central water T-S curves are better described by a constant density ratio T-S curve than by a straight line connecting near-surface and intermediate water types. C1 PRINCETON UNIV,ATMOSPHER & OCEAN SCI PROGRAM,PRINCETON,NJ 08544. NR 17 TC 10 Z9 10 U1 0 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 FEB PY 1996 VL 26 IS 2 BP 267 EP 275 DI 10.1175/1520-0485(1996)026<0267:WODR>2.0.CO;2 PG 9 WC Oceanography SC Oceanography GA UB907 UT WOS:A1996UB90700008 ER PT J AU Pearce, EM Sawamoto, M Tirrell, DA Amis, EJ AF Pearce, EM Sawamoto, M Tirrell, DA Amis, EJ TI A half-century of the Journal of Polymer Science SO JOURNAL OF POLYMER SCIENCE PART B-POLYMER PHYSICS LA English DT Editorial Material RP Pearce, EM (reprint author), NIST,DIV POLYMERS,GAITHERSBURG,MD 20885, USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU JOHN WILEY & SONS INC PI NEW YORK PA 605 THIRD AVE, NEW YORK, NY 10158-0012 SN 0887-6266 J9 J POLYM SCI POL PHYS JI J. Polym. Sci. Pt. B-Polym. Phys. PD FEB PY 1996 VL 34 IS 3 BP 389 EP 389 DI 10.1002/polb.1996.889 PG 1 WC Polymer Science SC Polymer Science GA TR385 UT WOS:A1996TR38500001 ER PT J AU DiMarzio, EA Castellano, C Yang, A AF DiMarzio, EA Castellano, C Yang, A TI Class temperature depression of polymer by use of mixed solvents: A colligative property SO JOURNAL OF POLYMER SCIENCE PART B-POLYMER PHYSICS LA English DT Article DE colligative property; Gibbs DiMarzio entropy theory; glass temperature; plasticizers; polymer diluents ID GLASS TEMPERATURE; TRANSITION; SYSTEMS; BLENDS AB The entropy theory of glasses is used to determine the glass temperature depression by a multicomponent low molecular weight plasticizer (diluent). The glass temperature, T-g, is calculated as a function of pressure, P, the mole fractions, m(i), of the plasticizers, and the degree of polymerization p. One finds, provided there is no phase separation, that to a good approximation, the initial glass temperature depression is a function of the total mole fraction of plasticizer. Moreover, the glass temperature depression for small plasticizer molecules is found to be nearly a universal function of the plasticizer mole fraction (it depends on no other plasticizer variable), and to vary inversely as the number of flexible bonds per monomer unit of the polymer. A useful approximation is found, gamma dT(g)/dm(1) = -3T(g), where m(1) is the total mole fraction of diluent on a per monomer of polymer basis, and gamma is the number of flexible bonds per monomer. Although these results agree with experimental data in the literature, a more definitive experimental test is needed. (C) 1996 John Wiley & Sons, Inc. RP DiMarzio, EA (reprint author), NIST,GAITHERSBURG,MD 20899, USA. RI Castellano, Claudio/B-6946-2008 OI Castellano, Claudio/0000-0002-3773-3801 NR 27 TC 17 Z9 17 U1 0 U2 14 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 FEB PY 1996 VL 34 IS 3 BP 535 EP 543 DI 10.1002/(SICI)1099-0488(199602)34:3<535::AID-POLB12>3.0.CO;2-J PG 9 WC Polymer Science SC Polymer Science GA TR385 UT WOS:A1996TR38500017 ER PT J AU Allison, H Astaneh, A Baker, WF Bjorhovde, R deBuen, O Burgett, L Disque, RO Fisher, JM Geschwindner, LF Griffis, LG Gross, JL Ioannides, SA Kloiber, L Larson, JW Malley, JO MartinezRomero, E Murray, TM Nair, RS Ricker, DT Rongoe, JJ Stecich, J Thornton, WA Troup, EWJ Wiesner, KB Youssef, NFG AF Allison, H Astaneh, A Baker, WF Bjorhovde, R deBuen, O Burgett, L Disque, RO Fisher, JM Geschwindner, LF Griffis, LG Gross, JL Ioannides, SA Kloiber, L Larson, JW Malley, JO MartinezRomero, E Murray, TM Nair, RS Ricker, DT Rongoe, JJ Stecich, J Thornton, WA Troup, EWJ Wiesner, KB Youssef, NFG TI Compendium of design office problems - Volume 2 SO JOURNAL OF STRUCTURAL ENGINEERING-ASCE LA English DT Article ID LIMIT STATES DESIGN; FRAME AB The Committee on Design of Steel Building Structures of the Committee on Metals of the Structural Division of ASCE is engaged in an ongoing program to study and resolve structural engineering issues faced by the designers of steel buildings. The results of this work are being presented to the profession in a series of papers, of which this is the second. The first paper was published in the December 1992 issue of the Journal of Structural Engineering under the title ''Compendium of Design Office Problems.'' The emphasis is on practical solutions that the designer can use directly, without further research. Each issue is listed separately, with a technical discussion of the problem followed by a suggested solution, with references where appropriate. In addition, topics currently under study are listed, as are subjects identified by the Committee as needing investigation. C1 SKIDMORE OWINGS & MERRILL INC,CHICAGO,IL. UNIV PITTSBURGH,PITTSBURGH,PA. COLINAS DE BUEN SA,MEXICO CITY,DF,MEXICO. AMER INST STEEL CONSTRUCT,LILBURN,GA. BESIER GIBBLE NORDEN INC,OLD SAYBROOK,CT. COMPUTERIZED STRUCT DESIGN INC,MILWAUKEE,WI. PENN STATE UNIV,UNIVERSITY PK,PA 16802. WALTER P MOORE & ASSOCIATES,HOUSTON,TX. NATL INST STAND & TECHNOL,GAITHERSBURG,MD. STRUCT AFFILIATES INT INC,NASHVILLE,TN. LEJUENE STEEL CO,MINNEAPOLIS,MN. BETHLEHEM STEEL CORP,BETHLEHEM,PA 18016. HJ DEGENKOLB ASSOCIATES,SAN FRANCISCO,CA. ENRIQUE MARTINEZ ROMERO SA,MEXICO CITY,DF,MEXICO. VIRGINIA POLYTECH INST & STATE UNIV,BLACKSBURG,VA 24061. TENG & ASSOCIATES INC,CHICAGO,IL. ELSTNER ASSOCIATES INC,CHICAGO,IL. CIVES STEEL CO,ROSWELL,GA. LEMESSURIER CONSULTANTS INC,CAMBRIDGE,MA. NABIH YOUSSEF & ASSOCIATES,LOS ANGELES,CA. RP Allison, H (reprint author), UNIV CALIF BERKELEY,BERKELEY,CA 94720, USA. RI Gross, Jorge/G-9138-2012 NR 30 TC 0 Z9 0 U1 0 U2 1 PU ASCE-AMER SOC CIVIL ENG PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017-2398 SN 0733-9445 J9 J STRUCT ENG-ASCE JI J. Struct. Eng.-ASCE PD FEB PY 1996 VL 122 IS 2 BP 116 EP 124 PG 9 WC Construction & Building Technology; Engineering, Civil SC Construction & Building Technology; Engineering GA TT079 UT WOS:A1996TT07900002 ER PT J AU French, JD Wiederhorn, SM AF French, JD Wiederhorn, SM TI Tensile specimens from ceramic components SO JOURNAL OF THE AMERICAN CERAMIC SOCIETY LA English DT Article ID CREEP AB Three sizes of flat tensile specimens, 76.2 mm, 50.8 mm, and 30 mm long, were developed for tensile testing of experimental lots of material and material taken from ceramic components. Five replicate measurements on each specimen type, at each of two test conditions, yielded statistically indistinguishable creep and creep rupture results, Additional studies indicate that creep testing at 400 MPa on the 76.2 mm and 50.8 mm specimens and 350 MPa on the 30 mm specimen is feasible, limited only by the strength or slow crack growth resistance of the loading pins. C1 NIST,MAT SCI & ENGN LAB,GAITHERSBURG,MD 20899. NR 7 TC 31 Z9 31 U1 0 U2 1 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 FEB PY 1996 VL 79 IS 2 BP 550 EP 552 DI 10.1111/j.1151-2916.1996.tb08166.x PG 3 WC Materials Science, Ceramics SC Materials Science GA TW371 UT WOS:A1996TW37100048 ER PT J AU Harman, D AF Harman, D TI Gerald Salton, March 8, 1927 to August 28, 1995 - In memoriam SO JOURNAL OF THE AMERICAN SOCIETY FOR INFORMATION SCIENCE LA English DT Item About an Individual RP Harman, D (reprint author), NATL INST STAND & TECHNOL,GAITHERSBURG,MD 20899, USA. NR 0 TC 0 Z9 0 U1 0 U2 1 PU JOHN WILEY & SONS INC PI NEW YORK PA 605 THIRD AVE, NEW YORK, NY 10158-0012 SN 0002-8231 J9 J AM SOC INFORM SCI JI J. Am. Soc. Inf. Sci. PD FEB PY 1996 VL 47 IS 2 BP 113 EP 113 PG 1 WC Computer Science, Information Systems; Information Science & Library Science SC Computer Science; Information Science & Library Science GA TR396 UT WOS:A1996TR39600006 ER PT J AU Parker, J Clark, CW AF Parker, J Clark, CW TI Study of a plane-wave final-state theory of above-threshold ionization and harmonic generation SO JOURNAL OF THE OPTICAL SOCIETY OF AMERICA B-OPTICAL PHYSICS LA English DT Article ID KELDYSH THEORY; LASER FIELDS; INTENSE; MODEL; ATOMS AB We compare the predictions of a plane-wave final-state theory of above-threshold ionization with the results of a numerical integration of Schrodinger's equation. Good qualitative agreement between the model and the numerical integration is observed up to laser intensities of 10(14) cm(-2) in three-photon ionization of the Is state of atomic hydrogen. The plane-wave final-state model is also used to calculate the power spectrum of light radiated by the single atom in intense fields, again with good agreement between the model and the numerical integration. The results demonstrate the importance of the above-threshold ionization transitions in accurate calculations of power spectra of radiated light. When the atom is modeled with bound states alone, without the above-threshold ionization inherent in the plane-wave final state, then agreement between the model and the full numerical integration is poor. C1 UNIV MARYLAND,INST PHYS SCI & TECHNOL,COLLEGE PK,MD 20742. RP Parker, J (reprint author), NATL INST STAND & TECHNOL,PHYS LAB,GAITHERSBURG,MD 20899, USA. RI Clark, Charles/A-8594-2009 OI Clark, Charles/0000-0001-8724-9885 NR 26 TC 8 Z9 8 U1 0 U2 1 PU OPTICAL SOC AMER PI WASHINGTON PA 2010 MASSACHUSETTS AVE NW, WASHINGTON, DC 20036 SN 0740-3224 J9 J OPT SOC AM B JI J. Opt. Soc. Am. B-Opt. Phys. PD FEB PY 1996 VL 13 IS 2 BP 371 EP 379 DI 10.1364/JOSAB.13.000371 PG 9 WC Optics SC Optics GA TU987 UT WOS:A1996TU98700016 ER PT J AU Fonseca, MS Kenworthy, WJ Courtney, FX AF Fonseca, MS Kenworthy, WJ Courtney, FX TI Development of planted seagrass beds in Tampa Bay, Florida, USA .1. Plant components SO MARINE ECOLOGY PROGRESS SERIES LA English DT Article DE seagrass; restoration; macroalgae; mitigation; density; biomass ID MEADOWS; LAGOON AB In this study we evaluated the floral attributes of planted seagrass beds as they developed over time. The seagrasses Halodule wrightii and Syringodium filiforme were planted on 0.5 m centers at several sites within Tampa Bay, Florida, USA. Planting unit (PU) survival, change in areal shoot density, plant morphometrics and associated macroalgae were monitored over a 3 yr period. These parameters were compared with nearby, natural beds as a reference. Comparisons were not limited to the same species, but included Thalassia testudinum in order to address management issues regarding the substitution of one habitat type for another. Despite use of experienced personnel, in some plantings, an average 47% loss of PU was sustained, apparently due to seasonal bioturbation. Depending on the spatial distribution of loss, persistent cover at equivalent densities was still attained within 1.8 yr (for plantings on 0.5 m centers) over portions of some planted sites. Seagrass recovery rate and recommended monitoring times have a positive, linear relationship to spacing of plantings. Although moderately variable, areal shoot density clearly defined trends in bed development over time. Many plantings exhibited little spread in the first year after planting, and then expanded rapidly in the second year. Seagrass surface area, length or biomass, as well as macroalgal biomass, proved to be weak indicators of system development for most seagrass species. Although substantial PU losses were experienced, the subsequent survival, spread and persistence of seagrasses indicate that large areas of Tampa Bay, which historically had supported seagrass, are now suitable for restoration. For remaining seagrass habitat however, conservation provides a more certain basis for maintaining the resource than attempting to mitigate through planting. C1 FLORIDA DEPT ENVIRONM PROTECT, MARINE RES INST, ST PETERSBURG, FL 33701 USA. RP Fonseca, MS (reprint author), NOAA, NATL MARINE FISHERIES SERV, SE FISHERIES CTR, BEAUFORT LAB, BEAUFORT, NC 28516 USA. NR 30 TC 56 Z9 63 U1 2 U2 14 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 FEB PY 1996 VL 132 IS 1-3 BP 127 EP 139 DI 10.3354/meps132127 PG 13 WC Ecology; Marine & Freshwater Biology; Oceanography SC Environmental Sciences & Ecology; Marine & Freshwater Biology; Oceanography GA UD223 UT WOS:A1996UD22300013 ER PT J AU Fonseca, MS Meyer, DL Hall, MO AF Fonseca, MS Meyer, DL Hall, MO TI Development of planted seagrass beds in Tampa Bay, Florida, USA .2. Faunal components SO MARINE ECOLOGY PROGRESS SERIES LA English DT Article DE seagrass; fauna; threshold response; mitigation ID MACROFAUNAL ASSEMBLAGES; TRANSPLANTED EELGRASS; ARTIFICIAL SEAGRASS; HABITAT COMPLEXITY; SPECIES RICHNESS; ZOSTERA-MARINA; FISH; MEADOWS; PREY; ABUNDANCE AB In this paper we report on changes in shrimp, fish and crab abundance, composition and size in planted Halodule wrightii and Syringodium filiforme beds as compared to unvegetated, and natural, H. wrightii, S. filiforme, and Thalassia testudinum habitats in Tampa Bay, Florida, USA, over a 3 yr period (1987 to 1996). Using a gear type selective for small resident macroepibenthic fauna (1 m(2) dropnets), we found that in 1.8 yr H. wrightii planted on 0.5 m centers developed an animal density, number of taxa, and species composition equivalent to that found in natural beds. Animals tended to be larger in planted beds over the course of the study. Comparison of planted S. filiforme and mixed H. wrightii and S. filiforme with natural beds was impaired due to failure of several planting areas but exhibited a pattern of development similar in some ways to that of planted H. wrightii. Macroepibenthic animal density in planted beds displayed an asymptotic relationship with areal shoot density, where animal densities became equal to natural beds at shoot densities only a third of the average density for natural beds. This pattern corroborates the existence of threshold values of habitat structure in seagrass beds influencing numerical abundance of some associated animal communities. Macroepibenthic faunal abundance and composition in planted beds could be inferred from the amount of areal coverage of seagrass and its persistence over time, while measurement of areal shoot density may provide an important first check point on the road to functional restoration of seagrass habitat. C1 FLORIDA DEPT ENVIRONM PROTECT, MARINE RES INST, ST PETERSBURG, FL 33701 USA. RP Fonseca, MS (reprint author), NOAA, NATL MARINE FISHERIES SERV, SE FISHERIES CTR, BEAUFORT LAB, BEAUFORT, NC 28516 USA. NR 55 TC 46 Z9 51 U1 2 U2 9 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 FEB PY 1996 VL 132 IS 1-3 BP 141 EP 156 DI 10.3354/meps132141 PG 16 WC Ecology; Marine & Freshwater Biology; Oceanography SC Environmental Sciences & Ecology; Marine & Freshwater Biology; Oceanography GA UD223 UT WOS:A1996UD22300014 ER PT J AU Zamon, JE Greene, CH Eli, MT Demer, DA Hewitt, RP Sexton, S AF Zamon, JE Greene, CH Eli, MT Demer, DA Hewitt, RP Sexton, S TI Acoustic characterization of the three-dimensional prey field of foraging chinstrap penguins SO MARINE ECOLOGY PROGRESS SERIES LA English DT Article DE Antarctic krill; Euphausia superba; Chinstrap penguin; Pygoscelis antarctica; foraging ecology; patchiness; fisheries management; hydroacoustics ID EUPHAUSIA-SUPERBA; ANTARCTIC KRILL; SEA OTTERS; SEABIRDS; COMMUNITIES; MANAGEMENT; ABUNDANCE; BEHAVIOR; PREDATOR; ISLAND AB Few studies of diving predators have explicitly addressed the 3-dimensional nature of interactions between predators and prey at the spatial and temporal scales relevant to an individual predator's search behavior. Here, we present a new method for examining such interactions using the results from an acoustic survey of krill availability to foraging penguins. Analyses of fine-scale krill distributions within a 1852 x 1852 x 50 m volume of ocean revealed substantial prey patchiness in all dimensions. Our survey detected the presence of at least 6 krill aggregations in the survey area. The surface distribution of penguins was associated with the edges of these aggregations and was nonrandomly associated with krill densities above 0.1 krill m(-3) in the 30 to 40 m depth layer. The latter association was masked when krill abundance was integrated over the entire water column. Given that mean daytime dive depths for chinstrap penguins fall between 30 and 40 m, our data suggest penguins may fail to detect or choose to pass by shallow, denser prey aggregations and successfully forage on deeper, more homogeneously distributed krill offering higher encounter probabilities per unit volume searched. These findings reveal biologically important features of prey patchiness that cannot be addressed within the limitations of a primarily 2-dimensional analysis of predator-prey distributions. We emphasize that if we hope to gain a predictive understanding of the foraging behavior of diving predators, then we must consider fine-scale, 3-dimensional patterns of prey patchiness when assessing the availability of prey to diving predators. C1 CORNELL UNIV, ECOL & SYSTEMAT SECT, ITHACA, NY 14853 USA. CORNELL UNIV, OCEAN RESOURCES & ECOSYST PROGRAM, ITHACA, NY 14853 USA. UNIV CALIF SAN DIEGO, INST OCEANOG SCI, LA JOLLA, CA 92038 USA. SW FISHERIES SCI CTR, LA JOLLA, CA 92038 USA. NR 43 TC 25 Z9 26 U1 0 U2 1 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 FEB PY 1996 VL 131 IS 1-3 BP 1 EP 10 DI 10.3354/meps131001 PG 10 WC Ecology; Marine & Freshwater Biology; Oceanography SC Environmental Sciences & Ecology; Marine & Freshwater Biology; Oceanography GA TZ663 UT WOS:A1996TZ66300001 ER EF